Larmor diffraction in the ferromagnetic superconductor UGe{sub 2}
Energy Technology Data Exchange (ETDEWEB)
Ritz, Robert; Pfleiderer, Christian [Physik Department E21, TU Muenchen, D-85748 Garching (Germany); Sokolov, Dmitry; Huxley, Andrew [School of Physics and Astronomy, Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Keller, Thomas [MPI fuer Festkoerperforschung, Heisenbergstr. 1, D-70569 Stuttgart (Germany)
2010-07-01
Larmor Diffaction (LD) is a neutron resonance spin-echo technique which allows the study of the lattice constant as well the distribution of lattice constants. It was traditionally thought that neutron spin-echo measurements cannot be used in materials such as superconductors or ferromagnets, because they strongly depolarize a polarized neutron beam. In UGe{sub 2} we are able to demonstrate that this technique may be applied in ferromagnetic superconductors with a magnetic Ising anisotropy. UGe{sub 2} exhibits two ferromagnetic phases which are separated by a transition at temperature T{sub x}. With increasing hydrostatic pressure superconductivity emerges at the pressure for which T{sub x} is suppressed. Using LD we studied the temperature dependence of the lattice constant as well as the distribution of lattice constants for all three axis of UGe{sub 2} down to 0.5 K and at pressures up to 12 kbar.
Crystal growth of uranium compounds and study of UGe2
International Nuclear Information System (INIS)
Taufour, V.
2011-01-01
In this thesis, the study on the superconducting ferromagnet UGe 2 is presented. Crystal growth of UGe 2 single crystals was realized in a tetra-arc furnace using the Czochralski technique. This technique was also used to obtain high quality single crystals of other uranium compounds, notably UCoGe and URu 2 Si 2 . The Curie temperature of UGe 2 (T(Curie) = 53 K) decreases with pressure and is suppressed at p c = 1.5 GPa. Before being suppressed, the ferromagnetic transition changes from second to first order at a tricritical point. Precise resistivity and Hall resistivity measurements under pressure and magnetic field revealed the position of the tricritical point as well as its evolution under magnetic field which draw a wing structure phase diagram. Despite the theoretical prediction that this diagram is general for a ferromagnet, here we present the first experimental observation. Other measurements focus on the superconductivity (T sc = 0.75 K) which coexists with ferromagnetism under pressure. The bulk nature of the superconductivity is investigated by AC calorimetry measurements under pressure. The attention is turned to the interesting phenomenon of field enhanced superconductivity. (author) [fr
Larmor diffraction studies on the ferromagnetic superconductor UGe{sub 2}
Energy Technology Data Exchange (ETDEWEB)
Ritz, Robert; Pfleiderer, Christian [Physik Department E21, TU Muenchen, Garching (Germany); Sokolov, Dmitry; Huxley, Andrew D. [School of Physics and Astronomy, and Centre for Science at Extreme Conditions, The University of Edinburgh (United Kingdom); Keller, Thomas [MPI fuer Festkoerperforschung, Stuttgart (Germany)
2011-07-01
Larmor diffraction (LD) is a novel technique based on the Larmor precession of polarized neutrons that surpasses the resolution of conventional scattering methods by two orders of magnitude. For a long time it was thought that it is not possible to measure LD on systems with depolarizing properties, such as ferromagnets. We present thermal expansion measurements under pressure by means of Larmor diffraction (LD) on the superconducting Ising ferromagnet UGe{sub 2}. LD allowed us to measure magnetization and thermal expansion under pressure in the same setup and hence to directly compare transition temperatures. We found that the thermal expansion near T{sub X}, the transition between two ferromagnetic phases which is believed to drive superconductivity, shows a clear transition in the b- and c-axis under pressure at a temperature a few K higher than for the a-axis and the ferromagnetic Bragg peak. We are considering different mechanisms how this may be connected with the superconductivity in UGe{sub 2}.
Tricritical point of a ferromagnetic transition in UGe2
International Nuclear Information System (INIS)
Kabeya, N; Iijima, R; Osaki, E; Ban, S; Imura, K; Deguchi, K; Sato, N K; Aso, N; Homma, Y; Shiokawa, Y
2010-01-01
Thermal expansion and magnetostriction measurements of the superconducting ferromagnet UGe 2 under pressure were carried out. The temperature dependence of the thermal expansion coefficient shows a peak at the Curie temperature. When pressure is varied, the peak exhibits a maximum in the vicinity of a tricritical point (TCP), which separates the second-order phase transition from the first-order transition. From results of these measurements, we first construct the magnetic phase diagram including the TCP (P TCP ∼ 12.5 kbar). We also show that two lines characterizing the metamagnetism and the magnetic susceptibility emerge from the TCP. We argue that these magnetic properties in the vicinity of the TCP can be understood within a phenomenological frame of spin fluctuations.
Troć, R.; Gajek, Z.; Pikul, A.
2012-12-01
Single-crystalline UGe2 was investigated by means of magnetic susceptibility, magnetization, electrical resistivity, magnetoresistivity, and specific-heat measurements, all carried out in wide temperature and magnetic-field ranges. An analysis of the obtained data points out the dual behavior of the 5f electrons in this compound, i.e., possessing simultaneously local and itinerant characters in two substates. The magnetic and thermal characteristics of the compound were modeled using the effective crystal field (CF) in the intermediate coupling scheme and initial parameters obtained in the angular overlap model. Various configurations of the localized 5fn (n = 1, 2, and 3) electrons on the uranium ion have been probed. The best results were obtained for the 5f2 (U4+) configuration. The CF parameters obtained in the paramagnetic region allowed us to reproduce satisfactorily the experimental findings in the whole temperature range including also the magnitude of the ordered magnetic moment of uranium at low temperature. The electrical resistivity data after subtraction of the phonon contribution reveal the presence of a Kondo-like interaction in UGe2 supporting the idea of partial localization of the 5f electrons in UGe2. On the other hand, magnetoresistivity and an excess of specific heat originated from the hybridized (itinerant) part of 5f states, apparent around the characteristic temperature T*, give a distinct signature for the presence of the coupled charge-density wave and spin-density wave fluctuations over all the ferromagnetic region with a maximum at T*, postulated earlier in the literature.
Magnetic anisotropy study of UGe2in a static high magnetic field
International Nuclear Information System (INIS)
Sakon, T; Saito, S; Koyama, K; Awaji, S; Sato, I; Nojima, T; Watanabe, K; Motokawa, M; Sato, N K
2006-01-01
UGe 2 has orthorhombic C mmm crystalline symmetry and shows ferromagnetic Heavy-Fermion (HF) Superconductor, which provides superconductivity under pressure in the range from 1.0 GPa to 1.5 GPa. Magnetic field dependence of magnetization shows strong magnetic anisotropy. When a magnetic field is applied parallel to easy axis (a-axis), magnetization presents ferromagnetic behavior. At 4.2 K, which is much lower than the Curie temperature T c = 54 K. Spontaneous magnetization is 1.4 μ B /U, and the magnetization gradually increase with increasing field. On the contrary, when a field is applied parallel to hard axis (b-axis or c-axis), magnetization increases linearly with increasing magnetic field. As for H//b-axis, magnetization is 0.23 μ B /U even at 27 T. Magnetocrystalline anisotropy constant is obtained as 230 [T μ B ] 3.4[kJ/kg] at 4.2 K. This value is comparable with rare-earth magnet Nd 2 Fe 17 , which is typical strongly correlated ferromagnet
Kan diplomstuderende læse en peer-reviewet artikel i den første uge?
Directory of Open Access Journals (Sweden)
Anker Helms Jørgensen
2014-09-01
Full Text Available Peer-reviewede artikler er det akademiske guld inden for de empiriske videnskaber. På trods af deres specialiserede, fagspecifikke indhold har de undervisningsmæssigt potentiale til at indvie de studerende i universitetets etos. Hvornår kan studerende læse sådanne artikler? I den allerførste uge på universitetet? Dette har jeg undersøgt i et kursus for diplomstuderende, hvoraf 2/3 aldrig har taget et kursus på et universitet. De arbejder med en frivillig øvelse i første uge: de læser en peer-reviewet artikel (Monk et al., 2004, skriver et abstract af den og giver hinanden feedback. Artiklens emne er alment: Hvorfor mobiltelefoner er generende i det offentlige rum? Den er velskrevet og giver et godt billede af, hvordan forskere arbejder. Artiklen er ledsaget af stilladsering med forklaringer, spørgsmål og svar. Undersøgelsen omfattede 94 studerende. Resultatet viser, at 89 % skrev et abstract, 96% fandt brugen i første uge acceptabel og 100 % mente, at øvelsen skulle gentages i næste semester. De studerende værdsatte artiklens autenticitet; de fandt det nyttigt og udfordrende at skrive tidligt; skrivningen fik dem til at tænke. Alt i alt var det en succesoplevelse, som gav dem blod på tanden. Det er således klart, at diplomstuderende kan læse en peer-reviewet artikel i den første uge med udbytte.Peer-reviewed papers are like academic gold in many disciplines. But when is it appropriate to introduce students to such papers? In their first week at university? To address this question diploma-students were asked to work with a peer-reviewed paper (Monk. et al 2004 during their first week. The students, two thirds of whom were new to university level education, were asked to write an abstract of the paper - voluntarily - and then give feedback to each other. The paper the students were given addressed the use of mobile phones in public spaces. It was selected for its readability and the exercise was supported with extensive
Kan diplomstuderende læse en peer-reviewet artikel i den første uge?
DEFF Research Database (Denmark)
Jørgensen, Anker Helms
2014-01-01
% skrev et abstract, 96% fandt brugen i første uge acceptabel og 100 % men- te, at øvelsen skulle gentages i næste semester. De studerende værdsatte artiklens autenticitet; de fandt det nyttigt og udfordrende at skrive tidligt; skrivningen fik dem til at tænke. Alt i alt var det en succesoplevelse, som...
International Nuclear Information System (INIS)
Konno, Rikio; Hatayama, Nobukuni
2011-01-01
The temperature dependence of thermal expansion of ferromagnetic superconductors below the superconducting transition temperature T scu of a majority spin conduction band is reexamined. In the previous study [to be published in J. M. Phys. B] the volume differential of the kinetic energy of conduction electrons is constant. However, in this study the volume differential of the kinetic energy of conduction electrons is inconstant. The superconducting gap of the majority spin conduction band used in this study has a line node. It is appropriate to UGe 2 . The pressure differential of its superconducting transition temperature is also investigated. We find that the thermal expansion coefficient has the divergence at the superconducting transition temperature. The thermodynamic Grueneisen's relation is satisfied.
Zhang, Wen; Liu, Yi; Wang, Xiaoying; Zhang, Yun; Xie, Donghua
2018-03-01
The heavy fermion physics arises from the complex interplay of nearly localized 4f/5f electrons and itinerant band-like ones, yielding heavy quasiparticles with an effective mass about 100 times (or more) of the bare electrons. Recently, experimental and theoretical investigations point out a localized and delocalized dual nature in actinide compounds, where itinerant quasiparticles account for the unconventional superconductivity in the vicinity of a magnetic instability. Here we report the strong coupling between localized 5f moments and itinerant quasiparticles in the ferromagnetic superconductor UGe2. The coupling is nearly antiferromagnetic. As embedded in the ferromagnetic matrix of localized 5f moments below {T}{{C}}≈ 52 {{K}}, this coupling leads to short-range dynamic correlations of heavy quasiparticles, characterized by fluctuations of magnetic clusters. Those cluster-like spins of itinerant quasiparticles show a broad hump of magnetization at {T}X≈ 28 {{K}}, which is typical for the spin-glass freezing. Thus, our results present the direct observation of itinerant quasiparticles coexisting with localized 5f moments by conventional magnetic measurements, providing a new route into the coexistence between ferromagnetism and superconductivity in heavy fermion systems. Project supported by the National Natural Science Foundation of China (Grant No. 11404297), the Science Challenge Project (Grant No. TZ2016004), and the Science and Technology Foundation of China Academy of Engineering Physics (Grant Nos. 2013B0301050 and 2014A0301013).
Kozić, Ružica; Meštrić, Lucija
2013-01-01
Projekt studentske radionice bio je kontrola DOF-a u mjerilu 1:2000 na području općine Đurđevac. Proveden je terenski dio kontrole točnosti DMR-a, DOF-a, izvedene signalizacije te načina signalizacije. Mjerenja su obavljena 19.travnja 2013. godine. Obavljena je ponovna izmjera GPS točaka homogenog polja Đurđevac RTK metodom u sustavu CROPOS s ciljem kontrole tih točaka, čije su koordinate već određene u sklopu izrade DOF2. Uz trajno stabilizirane točke homogenog polja, RTK metodom snimane su ...
DEFF Research Database (Denmark)
Temmesen, Camilla Gry
2017-01-01
og er skrevet af Camilla Gry Temmesen, uddannet dansk jordemoder og kandidat i jordemodervidenskab. De første 10 uger er gratis. De følgende uger kan tilgås efter køb in-app. Om Graviditetskalenderen: - Følg din graviditet uge for uge i billeder og tekst. Indtaster du din terminsdato, vil app’en åbne......’ens leksikon kan du få gode informationer, vejledning og forklaringer af de mange begreber, som er knyttet til graviditet. - Teksten bygger på danske vejledende anbefalinger inden for graviditet, fødsel og barsel og er skrevet af en uddannet jordemoder. - Camilla Gry Temmesen er cand. scient. san. i...
Huang, Jie-Hong; Kortstee, Anne; Dees, Dianka C T; Trindade, Luisa M; Schols, Henk A; Gruppen, Harry
2016-08-01
Uridine diphosphate (UDP)-glucose 4-epimerase (UGE) catalyzes the conversion of UDP-glucose to UDP-galactose. Cell wall materials from the cv. Kardal (wild-type, background) and two UGE transgenic lines (UGE 45-1 and UGE 51-16) were isolated and fractionated. The galactose (Gal) content (mg/100g tuber) from UGE 45-1 transgenic line was 38% higher than that of wild-type, and resulted in longer pectin side chains. The Gal content present in UGE 51-16 was 17% lower than that of wild-type, although most pectin populations maintained the same level of Gal. Both UGE transgenic lines showed unexpectedly a decrease in acetylation and an increase in methyl-esterification of pectin. Both UGE transgenic lines showed similar proportions of homogalacturonan and rhamnogalacturonan I within pectin backbone as the wild-type, except for the calcium-bound pectin fraction exhibiting relatively less rhamnogalacturonan I. Next to pectin modification, xyloglucan populations from both transgenic lines were altered resulting in different XSGG and XXGG proportion in comparison to wild-type. Copyright © 2016 Elsevier Ltd. All rights reserved.
Paul, Biplab C; El-Ganiny, Amira M; Abbas, Mariam; Kaminskyj, Susan G W; Dahms, Tanya E S
2011-05-01
The fungal wall mediates cell-environment interactions. Galactofuranose (Galf), the five-member ring form of galactose, has a relatively low abundance in Aspergillus walls yet is important for fungal growth and fitness. Aspergillus nidulans strains deleted for Galf biosynthesis enzymes UgeA (UDP-glucose-4-epimerase) and UgmA (UDP-galactopyranose mutase) lacked immunolocalizable Galf, had growth and sporulation defects, and had abnormal wall architecture. We used atomic force microscopy and force spectroscopy to image and quantify cell wall viscoelasticity and surface adhesion of ugeAΔ and ugmAΔ strains. We compared the results for ugeAΔ and ugmAΔ strains with the results for a wild-type strain (AAE1) and the ugeB deletion strain, which has wild-type growth and sporulation. Our results suggest that UgeA and UgmA are important for cell wall surface subunit organization and wall viscoelasticity. The ugeAΔ and ugmAΔ strains had significantly larger surface subunits and lower cell wall viscoelastic moduli than those of AAE1 or ugeBΔ hyphae. Double deletion strains (ugeAΔ ugeBΔ and ugeAΔ ugmAΔ) had more-disorganized surface subunits than single deletion strains. Changes in wall surface structure correlated with changes in its viscoelastic modulus for both fixed and living hyphae. Wild-type walls had the largest viscoelastic modulus, while the walls of the double deletion strains had the smallest. The ugmAΔ strain and particularly the ugeAΔ ugmAΔ double deletion strain were more adhesive to hydrophilic surfaces than the wild type, consistent with changes in wall viscoelasticity and surface organization. We propose that Galf is necessary for full maturation of A. nidulans walls during hyphal extension.
Web-nyheder og tv-nyheder på DR og TV2
DEFF Research Database (Denmark)
Bang, Jørgen
2008-01-01
Artiklen undersøger forholdet med web-nyheder og tv-nyheder i danske public service (DR1 og TV2). Ud fra analyser af web-nyhederne og og tv-nyhederne i uge 4 og 17 sammenholdt med analyser af net-brugerne og tv-seerene i samme tidsrum påpeger artiklen at net-brugerne på de to stationer kun udgør ca...
DEFF Research Database (Denmark)
Salale, Nesrin; Treldal, Charlotte; Mogensen, Stine
2014-01-01
Unsedated upper gastrointestinal endoscopy (UGE) can induce patient discomfort, mainly due to a strong gag reflex. The aim was to assess the effect of a bupivacaine lozenge as topical pharyngeal anesthetic compared with standard treatment with a lidocaine spray before UGE. Ninety-nine adult...... with a lidocaine spray proved to be a superior option as topical pharyngeal anesthetic before an UGE....
Directory of Open Access Journals (Sweden)
Liang Xu
2017-06-01
Full Text Available Sodium-glucose cotransporter (SGLT 2 inhibitors increase urinary glucose excretion (UGE, leading to blood glucose reductions and weight loss. However, the impacts of SGLT2 inhibition on energy homeostasis and obesity-induced insulin resistance are less well known. Here, we show that empagliflozin, a SGLT2 inhibitor, enhanced energy expenditure and attenuated inflammation and insulin resistance in high-fat-diet-induced obese (DIO mice. C57BL/6J mice were pair-fed a high-fat diet (HFD or a HFD with empagliflozin for 16 weeks. Empagliflozin administration increased UGE in the DIO mice, whereas it suppressed HFD-induced weight gain, insulin resistance, and hepatic steatosis. Moreover, empagliflozin shifted energy metabolism towards fat utilization, elevated AMP-activated protein kinase and acetyl-CoA carbolxylase phosphorylation in skeletal muscle, and increased hepatic and plasma fibroblast growth factor 21 levels. Importantly, empagliflozin increased energy expenditure, heat production, and the expression of uncoupling protein 1 in brown fat and in inguinal and epididymal white adipose tissue (WAT. Furthermore, empagliflozin reduced M1-polarized macrophage accumulation while inducing the anti-inflammatory M2 phenotype of macrophages within WAT and liver, lowering plasma TNFα levels and attenuating obesity-related chronic inflammation. Thus, empagliflozin suppressed weight gain by enhancing fat utilization and browning and attenuated obesity-induced inflammation and insulin resistance by polarizing M2 macrophages in WAT and liver.
Directory of Open Access Journals (Sweden)
Joshua J Neumiller
2014-06-01
Full Text Available Type 2 diabetes is increasing in prevalence worldwide, and hyperglycemia is often poorly controlled despite a number of therapeutic options. Unlike previously available agents, sodium-glucose co-transporter 2 (SGLT2 inhibitors offer an insulin-independent mechanism for improving blood glucose levels, since they promote urinary glucose excretion (UGE by inhibiting glucose reabsorption in the kidney. In addition to glucose control, SGLT2 inhibitors are associated with weight loss and blood pressure reductions, and do not increase the risk of hypoglycemia. Empagliflozin is a selective inhibitor of SGLT2, providing dose-dependent UGE increases in healthy volunteers, with up to 90 g of glucose excreted per day. It can be administered orally, and studies of people with renal or hepatic impairment indicated empagliflozin needed no dose adjustment based on pharmacokinetics. In Phase II trials in patients with type 2 diabetes, empagliflozin provided improvements in glycosylated hemoglobin (HbA1c and other measures of glycemic control when given as monotherapy or add-on to metformin, as well as reductions in weight and systolic blood pressure. As add-on to basal insulin, empagliflozin not only improved HbA1c levels but also reduced insulin doses. Across studies, empagliflozin was generally well tolerated with a similar rate of hypoglycemia to placebo; however, patients had a slightly increased frequency of genital infections, but not urinary tract infections, versus placebo. Phase III studies have also reported a good safety profile along with significant improvements in HbA1c, weight and blood pressure, with no increased risk of hypoglycemia versus placebo. Based on available data, it appears that empagliflozin may be a useful option in a range of patients; however, clinical decisions will be better informed by the results of ongoing studies, in particular, a large cardiovascular outcome study (EMPA-REG OUTCOME™.
International Nuclear Information System (INIS)
Ko, Kinarm; Moore, Robert W.; Peterson, Richard E.
2004-01-01
In utero exposure of male C57BL/6 mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) prevents prostatic epithelial buds from forming in the ventral region of the urogenital sinus (UGS) and reduces the number of buds that form in the dorsolateral region. This inhibition of budding is aryl hydrocarbon receptor (AHR) dependent and appears to be the primary cause of lobe-specific prostate abnormalities in TCDD-exposed mice. TCDD can inhibit prostatic epithelial bud formation by acting directly on the UGS in vitro, but whether it does so via AHR in UGS mesenchyme, epithelium, or both was unknown. To address this issue, UGS mesenchyme and epithelium from gestation day (GD) 15 wild-type C57BL/6J male mice were isolated, recombined, and cultured in vitro for 5 days with 10 -8 M 5α-dihydrotestosterone (DHT) and either 10 -9 M TCDD or vehicle. Prostatic epithelial buds were viewed by light microscopy after removal of mesenchyme. Effects depended greatly on which portions of the mesenchyme were used: TCDD had little if any effect when whole UGS epithelium (UGE) was recombined with ventral plus dorsolateral mesenchyme, tended to reduce bud numbers in recombinants made with UGE and dorsolateral mesenchyme, and severely reduced bud numbers in recombinants made with UGE and ventral mesenchyme (VM). [VM + UGE] recombinants prepared from wild-type and AHR knockout (Ahr -/- ) mice were then cultured with DHT to determine the site of action of TCDD. AHR null mutation alone had no effect on budding. TCDD severely inhibited prostatic epithelial bud formation in recombinants that contained mesenchymal AHR, whereas bud formation was not inhibited by TCDD in recombinants lacking mesenchymal AHR, regardless of epithelial AHR status. These results demonstrate that UGS mesenchyme and not UGS epithelium is the site of action of TCDD. Therefore, the initial events responsible for abnormal UGS (and ultimately prostate) development occur within the UGS mesenchyme, and changes in gene expression
Phenomenological description of anisotropy effects in some ferromagnetic superconductors
Energy Technology Data Exchange (ETDEWEB)
Shopova, Diana V., E-mail: sho@issp.bas.bg [TCCM Research Group, Institute of Solid State Physics, Bulgarian Academy of Sciences, BG-1784 Sofia (Bulgaria); Todorov, Michail D. [Department of Applied Mathematics and Computer Science, Technical University of Sofia, 1000 Sofia (Bulgaria)
2015-07-03
We study phenomenologically the role of anisotropy in ferromagnetic superconductors UGe{sub 2}, URhGe, and UCoGe for the description of their phase diagrams. We use the Ginzburg–Landau free energy in its uniform form as we will consider only spatially independent solutions. This is an expansion of previously derived results where the effect of Cooper-pair and crystal anisotropies is not taken into account. The three compounds are separately discussed with the special stress on UGe{sub 2}. The main effect comes from the strong uniaxial anisotropy of magnetization while the anisotropy of Cooper pairs and crystal anisotropy only slightly change the phase diagram in the vicinity of Curie temperature. The limitations of this approach are also discussed. - Highlights: • Anisotropic Landau energy for description of ferromagnetic superconductors is proposed. • Meissner phases are described with their existence and stability conditions. • The application of the model to UGe{sub 2} is discussed. • The limitations to apply the model for description of experimental data are explained.
Osman, Kamelia M; Hassan, Hany M; Orabi, Ahmed; Abdelhafez, Ahmed S T
2014-06-01
Studies on the prevalence and virulence genes of Klebsiella mastitis pathogens in a buffalo population are undocumented. Also, the association of rmpA kfu, uge, magA, Aerobactin, K1 and K2 virulent factors with K. pneumoniae buffalo, and cow mastitis is unreported. The virulence of K. pneumoniae was evaluated through both phenotypic and molecular assays. In vivo virulence was assessed by the Vero cell cytotoxicity, suckling mouse assay and mice lethality test. Antimicrobial susceptibility was tested by disk diffusion method. The 45 K. pneumoniae isolates from buffalo (n = 10/232) and cow (n = 35/293) milk were isolated (45/525; 8.6%) and screened via PCR for seven virulence genes encoding uridine diphosphate galactose 4 epimerase encoding gene responsible for capsule and smooth lipopolysaccharide synthesis (uge), siderophores (kfu and aerobactin), protectines or invasins (rmpA and magA), and the capsule and hypermucoviscosity (K1 and K2). The most common virulence genes were rmpA, kfu, uge, and magA (77.8% each). Aerobactin and K1 genes were found at medium rates of 66.7% each and K2 (55.6%). The Vero cell cytotoxicity and LD (50) in mice were found in 100% of isolates. A multidrug resistance pattern was observed for 40% of the antimicrobials. The distribution of virulence profiles indicate a role of rmpA, kfu, uge, magA, Aerobactin, and K1 and K2 in pathogenicity of K. pneumoniae in udder infections and invasiveness, and constitutes a threat for vulnerable animals, even more if they are in combination with antibiotic resistance.
Superconductivity and non-Fermi liquid behavior on the border of itinerant ferromagnetism
Energy Technology Data Exchange (ETDEWEB)
Ritz, Robert
2013-10-04
When magnetic order is suppressed under pressure, a superconducting (SC) phase emerges in the ferromagnet UGe{sub 2} and an extended non-Fermi liquid (NFL) regime is observed in the helimagnet MnSi. We report thermal expansion measurements of UGe{sub 2} under pressure by means of neutron Larmor diffraction. We find a new, putatively non-magnetic transition at the temperature TL at pressures close to the SC phase. In MnSi we report Hall effect measurements under pressure. We find a topological Hall effect, as the signature of a topologically non-trivial spin texture, above the critical pressure in the NFL regime.
On the use of contraction theory for the design of nonlinear observers for ocean vehicles
DEFF Research Database (Denmark)
Jouffroy, Jerome; Lottin, Jacques
and practice. This paper addresses the question of the applicability of contraction theory to the design of UGES observers for ocean vehicles. A relation between the concept of exponential convergence of a contracting system and uniform global exponential stability (UGES) is rst given. Then two contraction......Guaranteeing that traditional concepts of stability like uniform global exponential or asymptotic stability (UGES or UGAS) are veri ed when using design tools based on new concepts of stability may be of signicant importance. It is especially so when attempting to bridge the gap between theory...
Samukawa, Yoshishige; Haneda, Masakazu; Seino, Yutaka; Sasaki, Takashi; Fukatsu, Atsushi; Kubo, Yusuke; Sato, Yuri; Sakai, Soichi
2018-04-25
This open-label, parallel-group, multicenter study aimed to assess the effects of renal impairment on the pharmacokinetics, pharmacodynamics, and safety of luseogliflozin. A single 5-mg dose of luseogliflozin was administered to Japanese patients with type 2 diabetes mellitus in the following groups: G1, normal renal function; G2, mild renal impairment; G3a, mild to moderate impairment; G3b, moderate to severe impairment; G4, severe impairment, based on estimated glomerular filtration rate (eGFR; ≥90, 60-89, 45-59, 30-44, 15-29 mL/min/1.73 m 2 , respectively). While luseogliflozin pharmacokinetics were similar for patients across all renal function groups, the increase in plasma concentration was slightly slower and maximum concentration was slightly reduced in the lower eGFR groups compared with the other groups. However, luseogliflozin pharmacodynamics were affected by the severity of renal impairment. Urinary glucose excretion (UGE) increased in all groups relative to baseline levels, but the degree of UGE increase was smaller in the lower eGFR groups. Moreover, plasma glucose AUC changes from baseline tended to be smaller in the lower eGFR groups. No clear trends were observed between eGFR and incidence, type, or severity of adverse events. Thus, luseogliflozin administration should be carefully considered, as patients with renal impairment may show an insufficient response to treatment. © 2018 The Authors. Clinical Pharmacology in Drug Development Published by Wiley Periodicals, Inc. on behalf of The American College of Clinical Pharmacology.
Mondi, Makingu; Woods, Peter; Rafi, Ahmad
2007-01-01
This paper presents the systematic development of a "Uses and Gratification Expectancy" (UGE) conceptual framework which is able to predict students' "Perceived e-Learning Experience." It is argued that students' UGE as regards e-learning resources cannot be implicitly or explicitly explored without first examining underlying communication…
Ansatte hentede inspiration ved Burning Man-festival
DEFF Research Database (Denmark)
Rosenstand, Claus Andreas Foss
2012-01-01
Hvert år i den sidste uge af august omdasse en ørken dybt inde i Nevada til mekka for kunst,kreativ innovation og menneskelig udfoldelse......Hvert år i den sidste uge af august omdasse en ørken dybt inde i Nevada til mekka for kunst,kreativ innovation og menneskelig udfoldelse...
@AUforsker - forskningsformidling på twitter. Initiativtager og administrator
DEFF Research Database (Denmark)
Hansen, Lone Koefoed; Nielsen, Carsten Fogh
2013-01-01
AUforsker er en twitterkonto, hvor vi hver uge giver ordet til en ny forsker fra AU. "Uafhængigt drevet af forskere fra Aarhus Uni. En forsker = en uge. Bliv klogere på vores forskning, undervisning og hverdag." - Formålet med kontoen er bl.a. at formidle de mange forskellige former for forskning...
Analytical Method Details (MS): SE19_MS1 [Metabolonote[Archive
Lifescience Database Archive (English)
Full Text Available om temperature. Each phase separation was achieved by adding 2 mL chloroform and 2 mL water. After vortexing, the mixture was centrif...uged at 3000 rpm for 10 min. The bottom organic layer co
Sognenavne, Aabenraa Kommune (16 artikler). trap.dk
DEFF Research Database (Denmark)
Kællerød, Lars-Jakob Harding
2019-01-01
Artikler til Trap Danmarks netpublikation trap.dk Sognenavnene Bjolderup, Burkal, Bylderup, Egvad, Ensted, Genner, Hellevad, Hjordkær, Holbøl, Kliplev, Løjt, Ravsted, Rise, Uge, Varnæs og Øster Løgum......Artikler til Trap Danmarks netpublikation trap.dk Sognenavnene Bjolderup, Burkal, Bylderup, Egvad, Ensted, Genner, Hellevad, Hjordkær, Holbøl, Kliplev, Løjt, Ravsted, Rise, Uge, Varnæs og Øster Løgum...
Energy Technology Data Exchange (ETDEWEB)
Maglic, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)
1962-11-15
Reactivity of a reactor depends on production, absorption and leaking of neutrons. Change of absorption causes reactivity change, and this fact is used for determining the neutron absorption cross section for the sample inserted in the reactor core. Method for determining the absorption cross section based on reactivity change is called method of safety coefficient. Measurements of neutron absorption cross section for graphite was done in the RA reactor vertical experimental channel VK-5. taking into account the results obtained for five types of graphite this method is considered to be reliable for use. Comparison of nuclear properties of different types of graphite was done as well. Reaktivnost reaktora zavisi od proizvodnje neutrona, apsorpcije i isticanja neutrona. Promena apsorpcije izaziva promene reaktivnosti reaktora pa se ova osobina koristi za odedjivanje neutronskog apsorpcionog preseka uzorka koji se unosi u reaktor. Metoda merenja apsorpcionog preseka na bazi promene reaktivnosti nazvana je metodom koeficijenta opasnosti. Merenje apsorpcionog preseka grafita uradjeno je na reaktoru RA u vertikalnom eksperimentalnom kanalu VK-5. S obzirom na rezultate koji su dobijeni za pet vrsta grafita moze se smatrati da je opravdano koriscenje ove metode. Izvrseno je i poredjenje nuklearnih osobina pomenutih tipova grafita.
User-Generated Social Media Events in Tourism
Directory of Open Access Journals (Sweden)
Estela Marine-Roig
2017-12-01
Full Text Available Social media and mobile technologies have revolutionised communication and particular attention has been given to user-generated content (UGC and the formation of online communities; however, little attention has been given to tourist events entirely generated by users through social media. This paper aims to define and characterise the phenomenon of tourism user-generated events (UGEs through social media around the user’s new empowered role and to assess user-generated social media events’ online socialness. It is also our aim to provide a useful mixed-methodology analysis framework for UGEs in relation to social media and to highlight their interest for organisations. The methodological approach includes a quantitative model to store, analyse and compare events’ online socialness, which is combined with qualitative, participant observation at the events. This approach is applied to the analysis of three Instagram meetups organised by a specific online community at Catalan ski resorts. The paper’s results show the differential characteristic of tourism UGEs: user initiative and empowerment, full organisation and structure, great social media use and UGC production, brand dissemination, attraction capacity, strong online community bond and faithfulness. With UGEs, an event management paradigm shift occurs as organisations are no longer the main initiators and controllers of the event.
Vært for @AUforsker på Twitter 5.-11. dec. 2013
DEFF Research Database (Denmark)
Damkjaer, Maja Sonne
2013-01-01
@AUforsker på Twitter: Uafhængigt drevet af forskere fra Aarhus Uni. En forsker = en uge. Bliv klogere på vores forskning, undervisning og hverdag. 5.-11. dec. 2013 bestyret af @Majasdamkjaer Aarhus University, Denmark · au.dk......@AUforsker på Twitter: Uafhængigt drevet af forskere fra Aarhus Uni. En forsker = en uge. Bliv klogere på vores forskning, undervisning og hverdag. 5.-11. dec. 2013 bestyret af @Majasdamkjaer Aarhus University, Denmark · au.dk...
Superconductivity on the border of itinerant-electron ferromagnetism in UGe2
Saxena, SS; Ahilan, K; Grosche, FM; Haselwimmer, RKW; Steiner, MJ; Pugh, E; Walker, IR; Julian, [No Value; Monthoux, P; Lonzarich, GG; Huxley, A; Sheikin, [No Value; Braithwaite, D; Flouquet, J
2000-01-01
The absence of simple examples of superconductivity adjoining itinerant-electron ferromagnetism in the phase diagram has for many years cast doubt on the validity of conventional models of magnetically mediated superconductivity. On closer examination, however, very few systems have been studied in
Observation of two distinct magnetic states in ZrZn2 via the dHvA effect under pressure
International Nuclear Information System (INIS)
Kimura, N.; Endo, M.; Isshiki, T.; Ochiai, A.; Aoki, H.; Terashima, T.; Uji, S.; Matsumoto, T.; Lonzarich, G.G.
2005-01-01
We have found an anomaly in magnetic field dependence of the de Haas-van Alphen (dHvA) frequency of ZrZn 2 . Pressure dependence of this anomaly suggests an existence of two distinct ferromagnetic states and then a 'nested' phase diagram similar to that of UGe 2 . The Stoner exchange parameter and the exchange splitting energy are 400 and 66meV, respectively, which are derived from comparing the field dependence of the dHvA frequency difference with the magnetization. The two parameters do not change in both the low and slightly higher average moment states, suggesting that the phase transition between these states is ascribed to the change in the difference of majority and minority spin carrier densities
Spin and orbital magnetic state of UGe.sub.2./sub. under pressure
Czech Academy of Sciences Publication Activity Database
Shick, Alexander; Janiš, Václav; Drchal, Václav; Pickett, W. E.
2004-01-01
Roč. 70, č. 13 (2004), 134506/1-134506/5 ISSN 1098-0121 R&D Projects: GA ČR GA202/01/0764; GA MŠk ME 547 Institutional research plan: CEZ:AV0Z1010914 Keywords : magnetism * superconductivity * electron correlations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.075, year: 2004
Energy Technology Data Exchange (ETDEWEB)
Moussa, C.; El Sayah, Z. [Institut des Sciences Chimiques de Rennes, Chimie du Solide et Matériaux, UMR CNRS 6226, Université Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France); Chajewski, G. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okólna 2, 50-422 Wrocław (Poland); Berche, A.; Dorcet, V. [Institut des Sciences Chimiques de Rennes, Chimie du Solide et Matériaux, UMR CNRS 6226, Université Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France); Pikul, A.P. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okólna 2, 50-422 Wrocław (Poland); Pasturel, M. [Institut des Sciences Chimiques de Rennes, Chimie du Solide et Matériaux, UMR CNRS 6226, Université Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France); Joanny, L. [ScanMAT – CMEBA, University of Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France); Stepnik, B. [AREVA/CERCA, 10 Rue Juliette Récamier, 69006 Lyon (France); Tougait, O., E-mail: tougait@univ-rennes1.fr [Institut des Sciences Chimiques de Rennes, Chimie du Solide et Matériaux, UMR CNRS 6226, Université Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France); Unité de Catalyse et de Chimie du Solide, UMR CNRS 8181, Université de Lille, 59695 Villeneuve d' Ascq (France)
2016-11-15
The phase relations within the U-Al-Ge ternary system were studied for two isothermal sections, at 673 K for the whole Gibbs triangle and at 1173 K for the concentration range 25–100 at% U. The identification of the phases, their composition ranges and stability were determined by x-ray powder diffraction, scanning electron microscopy coupled to energy dispersive spectroscopy and differential thermal analysis. The tie-lines and the solubility domains were determined for the U-Ge and U-Al binaries, the UAl{sub 3}-UGe{sub 3} solid-solution and for the unique ternary intermediate phase U{sub 3}Al{sub 2−x}Ge{sub 3+x}. The experimental isopleth section of the pseudo-binary UAl{sub 3}-UGe{sub 3} reveals an isomorphous solid solution based on the Cu{sub 3}Au-type below the solidus. The U{sub 3}Al{sub 2−x}Ge{sub 3+x} solid solution extends for −0.1≤x≤1.35 and −0.2≤x≤1.5 at 673 K and 1173 K respectively. It crystallizes in the I-centered tetragonal symmetry. The reciprocal lattice of several compositions of the U{sub 3}Al{sub 2−x}Ge{sub 3+x} solid solution was examined by electron diffraction at room temperature, revealing the presence of a c-glide plane. Their crystal structure was refined by single crystal x-ray diffraction suggesting an isomorphous solid solution best described with the non-centrosymmetric space group I4cm in the paramagnetic domain. The magnetic measurements confirm the ferromagnetic ordering of the solid solution U{sub 3}Al{sub 2−x}Ge{sub 3+x} with an increase of Tc with the Al content. The thermal variation of the specific heat bear out the magnetic transitions with some delocalized character of the uranium 5f electrons. - Graphical abstract: The phase relations within the U-Al-Ge ternary system were experimentally assessed for two isothermal sections, at 673 K for the whole Gibbs triangle and at 1173 K for the concentration range 25–100 at% U. A complete UAl{sub 3}-UGe{sub 3} solid-solution based on the Cu{sub 3}Au-type forms
Heavy fermions and extreme conditions
International Nuclear Information System (INIS)
Cheikine, Ilia
2000-01-01
Three heavy electron systems, CeCu 2 Si 2 , CePd 2 Si 2 and UGe 2 , were investigated by transport, quantum oscillations (CePd 2 Si 2 ) and neutron diffraction (UGe 2 ) measurements. The experiments were performed under extreme conditions of very low temperature, high magnetic field and hydrostatic pressure. In the case of CeCu 2 Si 2 , we followed the evolution of the magnetic A-phase that is found to collapse rapidly under pressure. We found evidence for a relation between the A-phase and the presence of a maximum in the temperature dependence of H c2 . Our analysis showed that at low pressure, the sign of the exchange integral should be negative, thus superconductivity is enhanced by an increase in the paramagnetic susceptibility as in the Jaccarino-Peter effect. The anisotropy of the initial slope of H c2 and therefore that of the effective mass was found to change under pressure. For CePd 2 Si 2 , both the de Haas-van Alphen effect at ambient pressure and the electrical resistivity under pressure were studied. The latter reveals a non-Fermi liquid behavior in the vicinity of the antiferromagnetic quantum critical point, P c ∼ kbar. The analysis of H c2 at P c shows that the superconducting state is well described by a weak coupling, clean limit model with a slightly anisotropic orbital limit and a strongly anisotropic paramagnetic one. UGe 2 is shown to demonstrate the coexistence of ferromagnetism and superconductivity that develops just below the ferromagnetic quantum critical point, P c ∼16 kbar. The measurements of the resistivity under pressure point to a possible existence of another phase boundary and thus another quantum critical point, P x ∼ 12 kbar, within the ferromagnetic state. The P-T phase diagram containing both P c and P x was sketched, and a possible relation between P x and the development of superconductivity was discussed. The temperature dependence of H c2 demonstrates a variety of novel behaviors, which cannot be understood within
Portal hypertension and variceal bleeding: Clinical and pharmacological aspects
DEFF Research Database (Denmark)
Hobolth, Lise
2010-01-01
Blødende esophagus varicer er en af den mest frygtede komplikationer til cirrose og portal hypertension pga. den høje mortalitet. Et klassisk studie fra 1981 opgjorde 6-ugers mortaliteten til 42%, hvoraf 75% døde indenfor den første uge. Gennem de sidste 2-3 årtier er der introduceret en række nye...
Research Article Special Issue
African Journals Online (AJOL)
lanez
2017-11-24
Nov 24, 2017 ... presented materials in landscape architecture of artificial and natural objects, in designing .... [8] Agapov V.P. Aydemirov K.R. Raschet ferm metodom konechnykh elementov s uchetom ... finite difference energy method.
Energy Technology Data Exchange (ETDEWEB)
Kolar, D.; Slivnik, J.; Volavsek, B. [Jozef Stefan Nuclear Institute, Ljubljana, Yugoslavia (Slovenia)
1963-11-15
reduccion del hexafluoruro de uranio con amoniaco en fase gaseosa a 40 deg. C. Mediante una pirohidrolisis con vapor de agua e hidrogeno entre 500 y 600 deg. C, transformaron en dioxido de uranio el producto de grano muy fino retenido en precipitadores electricos. Por analisis termodiferencial y termogravimetrico observaron el desarrollo de la reaccion. Determinaron el fluor y el oxigeno contenidos en el dioxido de uranio y examinaron su estructura cristalina por analisis roentgenografico. Evaluaron diversas caracteristicas fisicoquimicas tales como el area superficial especifica, las dimensiones de las particulas y la densidad del polvo vibrado. A partir del polvo, prepararon pastillas prensadas y sinterizadas a 1350 deg. C. Obtuvieron densidades, variables segun las diversas condiciones de preparacion, que alcanzaron hasta el 94% del valor teorico. (author) [Russian] Vosstanovleniem geksaftorida urana ammiakom v gazovoj faze pri 40 deg. C byl poluchen kompleksnyj ammonij ftorid urana. Ehtot melkij poroshok uderzhivalsya v ehlektroosaditelyakh i perevodilsya v dvuokis' urana metodom pirogidrolieha vodyanymi parami i vodorodom pri temperature ot 500 do 600 deg. C. Khod reaktsii kontrolirovalsya metodom termicheskogo i termogravimetricheskogo analizov. V dvuokisi urana analiticheski opredelyalos' soderzhanie ftora i kisloroda, a kristallicheskaya struktura proveryalas' metodom rentgenovskogo analiza. Opredeleny nekotorye fiziko- khimicheskie' kharakteristiki , kak udel'naya poverkhnost', razmer chastits i konechnaya plotnost' poroshka. Iz poroshka pressovalis' tabletki, kotorye spekalis' pri 1350 deg. C. V zavisimosti ot razlichnykh uslovij izgotovleniya byli dostignuty plotnosti do 94% teoreticheskoj. (author)
Menetriere's disease associated with gastric adenocarcinoma in a child: imaging aspect
International Nuclear Information System (INIS)
Silva, Pedro Henrique Ramos Quintino da; Batista, Renan Pedroso; Rigo, Paula; Toma, Ricardo Katsuya; Oliveira, Luiz Antonio Nunes de; Suzuki, Lisa
2016-01-01
Female patient aged 18 years and 8 months, with diagnosis of hypertrophic gastritis since the age of 10, when she started having sporadic vomiting, weight loss, and anemia (Hb = 5.0 at diagnosis in August 2007). On her first upper gastrointestinal endoscopy (UGE) performed at the Instituto da Crianca (ICr) at HC-FMUSP, in August 2007, it was seem globally hypertrophied and swollen gastric mucosa, with an infiltrative lesion with ill-defined margins. A biopsy confirmed hyperplastic gastritis with a pattern of Menetrier's disease. Outpatient follow-up was initiated at Pediatric Gastroenterology Service of ICr in January 2008, with periodic clinical evaluation and UGE. The patient progressed in the following months with poor appetite and episodes of upper gastrointestinal bleeding and melena, requiring hospitalization in the city of origin and transfusions of blood concentrates. In the following years, she showed less recurrent episodes of bleeding than as seen in the first years after diagnosis, but continued undergoing serial UGEs for disease control and malignant surveillance, maintaining the same macroscopic and microscopic pattern. The patient has been submitted to extensive research for Helicobacter pylori in gastric biopsies, all with negative results, the same occurring with immunophenotyping for cytomegalovirus (CMV). Clinically, she continued to show poor weight gain, but with proper growth and no generalized edema at any time. (author)
Menetriere's disease associated with gastric adenocarcinoma in a child: imaging aspect
Energy Technology Data Exchange (ETDEWEB)
Silva, Pedro Henrique Ramos Quintino da; Batista, Renan Pedroso [Universidade de Sao Paulo (HC/FM/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina; Rigo, Paula; Toma, Ricardo Katsuya; Oliveira, Luiz Antonio Nunes de; Suzuki, Lisa, E-mail: lisa.suzuki@gmail.com [Universidade de Sao Paulo (HC/FM/USP), Sao Paulo, SP (Brazil). Instituto da Crianca
2016-09-15
Female patient aged 18 years and 8 months, with diagnosis of hypertrophic gastritis since the age of 10, when she started having sporadic vomiting, weight loss, and anemia (Hb = 5.0 at diagnosis in August 2007). On her first upper gastrointestinal endoscopy (UGE) performed at the Instituto da Crianca (ICr) at HC-FMUSP, in August 2007, it was seem globally hypertrophied and swollen gastric mucosa, with an infiltrative lesion with ill-defined margins. A biopsy confirmed hyperplastic gastritis with a pattern of Menetrier's disease. Outpatient follow-up was initiated at Pediatric Gastroenterology Service of ICr in January 2008, with periodic clinical evaluation and UGE. The patient progressed in the following months with poor appetite and episodes of upper gastrointestinal bleeding and melena, requiring hospitalization in the city of origin and transfusions of blood concentrates. In the following years, she showed less recurrent episodes of bleeding than as seen in the first years after diagnosis, but continued undergoing serial UGEs for disease control and malignant surveillance, maintaining the same macroscopic and microscopic pattern. The patient has been submitted to extensive research for Helicobacter pylori in gastric biopsies, all with negative results, the same occurring with immunophenotyping for cytomegalovirus (CMV). Clinically, she continued to show poor weight gain, but with proper growth and no generalized edema at any time. (author)
Svojstva i primena solova cerijum (IV) oksida sintetisanih postupkom forsirane hidrolize
Gulicovski, Jelena J.
2016-01-01
Stabilne koloidne disperzije (solovi) cerijum(IV)-oksida dobijeni su metodom forsirane hidrolize, polazeći od cerijum(IV)-nitrata i cerijum(IV)-sulfata u prisustvu različitih količina sumporne i azotne kiseline. Posebna pažnja posvećena je ispitivanju uticaja elektrolita KNO3 i K2SO4 na stabilnost pripremljenih koloidnih disperzija. Takođe, ispitana je mogućnost primene solova CeO2 za formiranje zaštitne prevlake na površini aluminijuma i primene praha CeO2 u oblasti skladištenja vodonika. ...
Energy Technology Data Exchange (ETDEWEB)
Spasic, Z; Simic, G [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)
1968-11-15
A vacuum chamber wad designed and constructed. It was suitable for study of materials at higher temperatures in vacuum or controlled atmospheres. Zircaloy-2 fatigue at 300 deg C in argon atmosphere was measured. Character of strain is variable one directional (A=1) tension. Obtained results are presented in tables and in the form of Veler's curve. The obtained fatigue limit was {sigma} - 15 kp/mm{sup 2}. The Locati method was allied as well and fatigue limit value obtained was 15,75 kp/mm{sup 2}. Error calculated in reference to the previous value obtained by classical methods was 5%. Konstruisana je i izvedena vakuum-komora koja se pokazala prikladna za izucavanje osobina materijala na povisenim temperaturama u vakuumu ili kontrolisanim atmosferama. Izvrseno je ispitivanje zamaranja Zircaloy-2 na temperaturi 300 deg C u atmosferi preciscenog argona. Karakter opterecenja je bio cisto jednosmerno promenljivo opterecenje (A=1) na zatezanje. Dobiveni rezultati su dati tabelarno i u obliku Velerove krive. Dobijena je granica zamora {sigma} = 15 kp/mm{sup 2}. Primenjen je i metod Locati-a za priblizno odredjivanje granice zamora i dobijena je vrednost 15,75 kp/mm{sup 2}. Greska u odnosu na prethodnu granicu zamora dobijenu klasicnim metodom iznosi 5% (author)
The Implementation Of A Critical Pedagogical Approach To Sexuality Education
DEFF Research Database (Denmark)
Roien, Line Anne; Simovska, Venka
Introduction/background Sexuality education is compulsory in Danish public school as a part of health education. There is a national curriculum which is based on the theory of critical health education and promotion (e.g. Jensen 1997; Carlsson et al 2009; Simovska & Jensen 2012), emphasising health...... suggests that the participation of teachers in the national sexuality education campaign, titled Uge Sex, has a positive impact on teachers’ practices through providing an appropriate support for teachers in implementing the critical pedagogical approach. Uge Sex is a campaign that aims at supporting...... as the campaign as a whole, are characterized by an approach to sexuality education inspired by the tradition of critical health education, as mentioned above, as well as norm critical pedagogy developed within the theory of Swedish queer pedagogy (Brade et al 2008, Bromseth et al 2010, Kirk et al 2010...
Phase development in a U-7 wt.% Mo vs. Al-7 wt.% Ge diffusion couple
Perez, E.; Keiser, D. D.; Sohn, Y. H.
2013-10-01
Fuel development for the Reduced Enrichment for Research and Test Reactors (RERTR) program has demonstrated that U-Mo alloys in contact with Al develop interaction regions with phases that have poor irradiation behavior. The addition of Si to the Al has been considered with positive results. In this study, compositional modification is considered by replacing Si with Ge to determine the effect on the phase development in the system. The microstructural and phase development of a diffusion couple of U-7 wt.% Mo in contact with Al-7 wt.% Ge was examined by transmission electron microscopy, scanning electron microscopy and energy dispersive spectroscopy. The interdiffusion zone developed a microstructure that included the cubic-UGe3 phase and amorphous phases. The UGe3 phase was observed with and without Mo and Al solid solution developing a (U,Mo)(Al,Ge)3 phase.
A "Uses and Gratification Expectancy Model" to Predict Students' "Perceived e-Learning Experience"
Mondi, Makingu; Woods, Peter; Rafi, Ahmad
2008-01-01
This study investigates "how and why" students' "Uses and Gratification Expectancy" (UGE) for e-learning resources influences their "Perceived e-Learning Experience." A "Uses and Gratification Expectancy Model" (UGEM) framework is proposed to predict students' "Perceived e-Learning Experience," and…
DEFF Research Database (Denmark)
Mogensen, Stine; Treldal, Charlotte; Feldager, Erik
2012-01-01
To evaluate the effect and acceptance of a new lidocaine lozenge compared with a lidocaine viscous oral solution as a pharyngeal anesthetic before upper gastrointestinal endoscopy (UGE), a diagnostic procedure commonly performed worldwide during which many patients experience severe discomfort...
DEFF Research Database (Denmark)
Hartelius, Anne Mette
2017-01-01
Efter en uge i 'Det vilde Østen' med alle sanser indstillet på østerlandsk æstetik kan man godt få den tanke, at vi alle har brug for designdisruption herhjemme i vores postmodernistiske vestlige del af verden....
DEFF Research Database (Denmark)
Nielsen, Charlotte Marie Bisgaard
2012-01-01
Artiklen analyserer maskinmetaforik med eksempel i Sundhedsstyrelsens uge-40 kampagne. Indledningsvis beskriver forfatteren baggrunden for den sproglige aflejring der af Erik Hollnagel og Roy Harris benævnes som "maskinmetaforer". Maskinmetaforer beskrives siden i teori og praksis, særligt i kamp...
Historien trækker sine blodige spor i Cataloniens drøm om selvstændighed
DEFF Research Database (Denmark)
Østergaard, Uffe
2017-01-01
Striden om, hvorvidt Catalonien er en region i Spanien eller en suveræn nationalstat i EU, kulminerer i næste uge med en kontroversiel folkeafstemning. Cataloniernes konflikt med den spanske centralmagt rækker langt tilbage i tiden historisk set....
Phase development in a U–7 wt.% Mo vs. Al–7 wt.% Ge diffusion couple
Energy Technology Data Exchange (ETDEWEB)
Perez, E., E-mail: Emmanuel.Perez@inl.gov [Nuclear Fuels and Materials Development, Idaho National Laboratory, Box 1625, Idaho Falls, ID 83415 (United States); Keiser, D.D. [Nuclear Fuels and Materials Development, Idaho National Laboratory, Box 1625, Idaho Falls, ID 83415 (United States); Sohn, Y.H. [Advanced Materials Processing and Analysis Center, and Department of Materials Science and Engineering, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL 32816 (United States)
2013-10-15
Fuel development for the Reduced Enrichment for Research and Test Reactors (RERTR) program has demonstrated that U–Mo alloys in contact with Al develop interaction regions with phases that have poor irradiation behavior. The addition of Si to the Al has been considered with positive results. In this study, compositional modification is considered by replacing Si with Ge to determine the effect on the phase development in the system. The microstructural and phase development of a diffusion couple of U–7 wt.% Mo in contact with Al–7 wt.% Ge was examined by transmission electron microscopy, scanning electron microscopy and energy dispersive spectroscopy. The interdiffusion zone developed a microstructure that included the cubic-UGe{sub 3} phase and amorphous phases. The UGe{sub 3} phase was observed with and without Mo and Al solid solution developing a (U,Mo)(Al,Ge){sub 3} phase.
in upper gastrointestinal endoscopy
Directory of Open Access Journals (Sweden)
Sinan Uzman
2016-07-01
Full Text Available Introduction : There is increasing interest in sedation for upper gastrointestinal endoscopy (UGE. Prospective randomized studies comparing sedation properties and complications of propofol and midazolam/meperidine in upper gastrointestinal endoscopy (UGE are few. Aim: To compare propofol and midazolam/meperidine sedation for UGE in terms of cardiopulmonary side effects, patient and endoscopist satisfaction and procedure-related times. Material and methods: This was a prospective, randomized, double-blind study of propofol versus midazolam and meperidine in 100 patients scheduled for diagnostic upper gastrointestinal endoscopy. The patients were divided into propofol and midazolam/meperidine groups. Randomization was generated by a computer. Cardiopulmonary side effects (hypotension, bradycardia, hypoxemia, procedure-related times (endoscopy time, awake time, time to hospital discharge, and patient and endoscopist satisfaction were compared between groups. Results: There was no significant difference between the groups with respect to the cost, endoscopy time, or demographic and clinical characteristics of the patients. Awake time and time to hospital discharge were significantly shorter in the propofol group (6.58 ±4.72 vs. 9.32 ±4.26 min, p = 0.030 and 27.60 ±7.88 vs. 32.00 ±10.54 min, p = 0.019. Hypotension incidence was significantly higher in the propofol group (12% vs. 0%, p = 0.027. The patient and endoscopist satisfaction was better with propofol. Conclusions : Propofol may be preferred to midazolam/meperidine sedation, with a shorter awake and hospital discharge time and better patient and endoscopist satisfaction. However, hypotension risk should be considered with propofol, and careful evaluation is needed, particularly in cardiopulmonary disorders.
Constantin, Lucian A; Fabiano, Eduardo; Della Sala, Fabio
2017-09-12
Using the semiclassical neutral atom theory, we developed a modified fourth-order kinetic energy (KE) gradient expansion (GE4m) that keeps unchanged all the linear-response terms of the uniform electron gas and gives a significant improvement with respect to the known semilocal functionals for both large atoms and jellium surfaces. On the other hand, GE4m is not accurate for light atoms; thus, we modified the GE4m coefficients making them dependent on a novel ingredient, the reduced Hartree potential, recently introduced in the Journal of Chemical Physics 2016, 145, 084110, in the context of exchange functionals. The resulting KE gradient expansion functional, named uGE4m, belongs to the novel class of u-meta-generalized-gradient-approximations (uMGGA) whose members depend on the conventional ingredients (i.e., the reduced gradient and Laplacian of the density) as well as on the reduced Hartree potential. To test uGE4m, we defined an appropriate benchmark (including total KE and KE differences for atoms, molecules and jellium clusters) for gradient expansion functionals, that is, including only those systems which are mainly described by a slowly varying density regime. While most of the GGA and meta-GGA KE functionals (we tested 18 of them) are accurate for some properties and inaccurate for others, uGE4m shows a consistently good performance for all the properties considered. This represents a qualitative boost in the KE functional development and highlights the importance of the reduced Hartree potential for the construction of next-generation KE functionals.
On magnon mediated Cooper pair formation in ferromagnetic superconductors
Directory of Open Access Journals (Sweden)
Rakesh Kar
2014-08-01
Full Text Available Identification of pairing mechanism leading to ferromagnetic superconductivity is one of the most challenging issues in condensed matter physics. Although different models have been proposed to explain this phenomenon, a quantitative understanding about this pairing is yet to be achieved. Using the localized-itinerant model, we find that in ferromagnetic superconducting materials both triplet pairing and singlet pairing of electrons are possible through magnon exchange depending upon whether the Debye cut off frequency of magnons is greater or lesser than the Hund's coupling (J multiplied by average spin (S per site. Taking into account the repulsive interaction due to the existence of paramagnons, we also find an expression for effective interaction potential between a pair of electrons with opposite spins. We apply the developed formalism in case of UGe2 and URhGe. The condition of singlet pairing is found to be fulfilled in these cases, as was previously envisaged by Suhl [Suhl, Phys. Rev. Lett. 87, 167007 (2001]. We compute the critical temperatures of URhGe at ambient pressure and of UGe2 under different pressures for the first time through BCS equation. Thus, this work outlines a very simple way to evaluate critical temperature in case of a superconducting system. A close match with the available experimental results strongly supports our theoretical treatment.
Analytical Method Details (MS): SE37_MS1 [Metabolonote[Archive
Lifescience Database Archive (English)
Full Text Available 20 times the volume of cool 80% methanol and mixed well. 4) Incubate it on ice for 30min and then centrif...uge it at 15,000/g for 20 min at 4 degree. 5) Collect the supernatants in a new gla
Kouwen, M.C.A. van; Drenth, J.P.H.; Verhoeven, H.M.; Bos, L.P.; Engels, L.G.
2003-01-01
We performed a cross sectional analysis of the feasibility and yield of upper gastrointestinal endoscopy (UGE) in a cohort of patients aged 85 years or more. The study involved 218 patients who underwent diagnostic upper gastrointestinal endoscopy in a district general hospital between 1994 and
Energy Technology Data Exchange (ETDEWEB)
Pop-Jordanov, J [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)
1962-07-15
Mono energetic neutron transport equation was solved by Carlson numerical method in cylindrical geometry. S{sub n} code was developed for the digital computer ZUSE Z23. Neutron flux distribution was determined for the RA reactor cell by applying S{sub 4} approximation. Reactor cell was treated as D{sub 2}O-U-D{sub 2}O system. Time of iteration was 185 s. Resena je transportna monoenergetska jednacina numerickom metodom Carlsona u cilindricnoj geometriji. Razvijanje S{sub n} kod za digitalnu masinu ZUSE-Z 23. Odredjena je raspodela fluksa u celiji reaktora RA S{sub 4} aproksimacijom. Celija je tretirana kao D{sub 2}O-U-D{sub 2}O. Vreme iteracije je 185 sec (author)
Directory of Open Access Journals (Sweden)
Chunlai Li
2011-07-01
Full Text Available Photosynthesis is the final determinator for crop yield. To gain insight into genes controlling photosynthetic capacity, we selected from our large T-DNA mutant population a rice stunted growth mutant with decreased carbon assimilate and yield production named photoassimilate defective1 (phd1. Molecular and biochemical analyses revealed that PHD1 encodes a novel chloroplast-localized UDP-glucose epimerase (UGE, which is conserved in the plant kingdom. The chloroplast localization of PHD1 was confirmed by immunoblots, immunocytochemistry, and UGE activity in isolated chloroplasts, which was approximately 50% lower in the phd1-1 mutant than in the wild type. In addition, the amounts of UDP-glucose and UDP-galactose substrates in chloroplasts were significantly higher and lower, respectively, indicating that PHD1 was responsible for a major part of UGE activity in plastids. The relative amount of monogalactosyldiacylglycerol (MGDG, a major chloroplast membrane galactolipid, was decreased in the mutant, while the digalactosyldiacylglycerol (DGDG amount was not significantly altered, suggesting that PHD1 participates mainly in UDP-galactose supply for MGDG biosynthesis in chloroplasts. The phd1 mutant showed decreased chlorophyll content, photosynthetic activity, and altered chloroplast ultrastructure, suggesting that a correct amount of galactoglycerolipids and the ratio of glycolipids versus phospholipids are necessary for proper chloroplast function. Downregulated expression of starch biosynthesis genes and upregulated expression of sucrose cleavage genes might be a result of reduced photosynthetic activity and account for the decreased starch and sucrose levels seen in phd1 leaves. PHD1 overexpression increased photosynthetic efficiency, biomass, and grain production, suggesting that PHD1 plays an important role in supplying sufficient galactolipids to thylakoid membranes for proper chloroplast biogenesis and photosynthetic activity. These
Integration eller assimilation
DEFF Research Database (Denmark)
Østergaard, Uffe
2017-01-01
Det var et yderst interessant interview, avisen bragte i sidste uge med den hollandske migrationsforsker Ruud Koopmans. Han beskriver ærligt sin bevægelse fra en naiv tro på multikulturalisme som måden at integrere indvandrere på til at stille benhårde krav til dem om kompetencer, sprog og accept...
Rutinemæssig igangsættelse i uge 39
DEFF Research Database (Denmark)
Rydahl, Eva; Hansen, Kit Dynnes; Schroll, Anne-Mette
2016-01-01
Flere epidemiologiske undersøgelser har vist, at risikoen for intrauterin mortalitet stiger efter 38. graviditetsuge for at øges betydeligt efter 42. graviditetsuge. Det har ført til, at amerikanske obstetrikere flirter med tanken om, at gravide rutinemæssigt skal have fødslen sat i gang efter ug...... 39 for at nedbringe forekomsten af intrauterin død. En gruppe danske jordemødre har set på evidens og på konsekvenser af tidligere igangsættelse i en dansk kontekst...
Superconductivity near ferromagnetism in MgCNi3
International Nuclear Information System (INIS)
Rosner, H.; Weht, R.; Johannes, M.; Pickett, W.E.; Tosatti, E.
2001-06-01
Superconductivity and ferromagnetism have been believed to be incompatible over any extended temperature range until certain specific examples - RuSr 2 GdCu 2 O 8 and UGe 2 - have arisen in the past 2-3 years. The discovery of superconductivity above 8 K in MgCNi 3 , which is primarily the ferromagnetic element Ni and is strongly exchange-enhanced, provides a probable new and different example. This compound is shown here to be near ferromagnetism, requiring only hole-doping by 12% substitution of Mg by Na or Li. This system will provide the means to probe coupling, and possible coexistence, of these two forms of collective behavior without the requirement of pressure. (author)
"Jonas, derefter Katrine og Sebastian": En enkel metode til at lære alle de studerendes navne
DEFF Research Database (Denmark)
Jørgensen, Anker Helms
2012-01-01
Denne artikel præsenterer en enkel, systematisk metode til at lære alle de studerendes navne i universitetsundervisning. Metoden er ret effektiv: I sidste semester lærte jeg 30 studerendes navne på 1.5 time; det svarer til 3 minutter pr. studerende og 6 minutter pr. uge. Min erfaring viser, at de...
"Jonas, derefter Katrine og Sebastian": En enkel metode til at lære alle de studerendes navne
DEFF Research Database (Denmark)
Jørgensen, Anker Helms
2013-01-01
Denne artikel præsenterer en enkel, systematisk metode til at lære alle de studerendes navne i universitetsundervisning. Metoden er ret effektiv: I sidste semester lærte jeg 30 studerendes navne på 1.5 time; det svarer til 3 minutter pr. studerende og 6 minutter pr. uge. En empirisk undersøgelse ...
DEFF Research Database (Denmark)
Kvistgaard, Peter
2005-01-01
Præsentationen tager udgangspunkt i Mou Skoles flex-uge. Ugen havde som hovedtema, at eleverne skulle finde nye oplevelser i deres lokalområde, så lokalområdet bedre kunne tiltrække turister i fremtiden. Præsentationen er derfor et oplæg, der skal inspirere eleverne til selv at finde og lave nye...
Finhvalen fra Blokhus og andre eksotiske fund
DEFF Research Database (Denmark)
Alstrup, Aage Kristian Olsen; Jensen, Lasse Fast; Olsen, Morten Tange
2016-01-01
I uge 8 strandede en død finhval (Balaenoptera physalus) ved Blokhus Strand. Finhvalen, der som bardehval lever af både fisk, blæksprutter og forskellige krebsdyr, er det næststørste pattedyr på kloden, kun overgået af den nært beslægtede blåhval (Balaenoptera musculus). Det stod hurtigt klart...
DEFF Research Database (Denmark)
Siim, Birte
2010-01-01
I den forløbne uge har 'burkasagen' og sagen om kønsopdelte grupper på Blågårdsskolen atter udfordret grænserne for det danske demokratis rummelighed. De to sager har vakt stor opsigt i pressen og har fremkaldt voldsomme udtalelser både fra repræsentanter for regeringen, dens støtteparti og fra t...
DEFF Research Database (Denmark)
Lauritzen, Heidi Hesselberg; Boje-Kovacs, Bence; Benjaminsen, Lars
Rapporten fremlægger resultaterne af den tredje nationale kortlægning af hjemløshed i Danmark og giver et ajourført billede af omfanget og karakteren af hjemløsheden. Ligesom i de to forrige optællinger blev der i kortlægningsugen (uge 6) registreret ca. 5.000 hjemløse. Sammensætningen af gruppen...
Hastighedsændringer som følge af ombygning af enkeltsporede rundkørsler i landzone til modulvogntog
DEFF Research Database (Denmark)
Tønning, Charlotte; Agerholm, Niels
2017-01-01
undtagelse af etableret overkørbart overkørselsareal i den ene. Personbilers free flow hastighed var undersøgt ved hjælp af RUBA software ud fra én uges videoregistrering i hver rundkørsel. I rundkørslen, hvor det overkørbare overkørselsareal var blevet etableret, steg gennemsnitshastigheden fra 28 til 36 km...
Aerodigitalni senzori - LH Systems ADS 40 / Airborne digital sensors: LH Systems ADS 40
Directory of Open Access Journals (Sweden)
Marko Pejić
2004-01-01
Full Text Available U radu su prezentovane osnove prikupljanja prostornih podataka metodom daljinske detekcije i klasičnim fotogrametrijskim metodom. Ukazano je na kompromis između dva metoda koji nudi digitalna aerokamera. Kompanija LH Systems proizvela je digitalnu aerokameru ADS 40 koja nudi sasvim nov koncept prikupljanja prostornih podataka. Sistem kamere obezbeđuje panhromatske i trodimenzionalne informacije koristeći tri CCD linije i opciono još pet linija iz multispektralnog opsega. Kamera skenira teren sa prostornom rezolucijom od 25 cm, površine od 300 kvadratnih kilometara, uz vreme trajanja leta koje je nešto kraće od jednog sata. / This paper presents basics of collecting spatial data with remote sensing and the classical photogrammetric method. A compromise between two methods, offered by a digital aero camera, is also suggested. The LH Systems has produced a new camera concept called Airborne Digital Sensor (ADS 40 which uses a new way of collecting spatial data. The camera system provides panchromatic and stereo information using three CCD lines and up to five more lines for multispectral imagery. The performance of the camera allows a three dimensional and multispectral image with a ground sample distance of 25 cm for an area of 300 square miles within a flight time shorter than one hour.
Parity violation effects in the Josephson junction of a p-wave superconductor
International Nuclear Information System (INIS)
Belov, Nikolay A.; Harman, Zoltán
2016-01-01
The phenomenon of the parity violation due to weak interaction may be studied with superconducting systems. Previous research considered the case of conventional superconductors. We here theoretically investigate the parity violation effect in an unconventional p-wave ferromagnetic superconductor, and find that its magnitude can be increased by three orders of magnitude, as compared to results of earlier studies. For potential experimental observations, the superconductor UGe_2 is suggested, together with the description of a possible experimental scheme allowing one to effectively measure and control the phenomenon. Furthermore, we put forward a setup for a further significant enhancement of the signature of parity violation in the system considered.
Piston cylinder cell for high pressure ultrasonic pulse echo measurements
Energy Technology Data Exchange (ETDEWEB)
Kepa, M. W., E-mail: mkepa@staffmail.ed.ac.uk; Huxley, A. D. [SUPA, Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Ridley, C. J.; Kamenev, K. V. [Centre for Science at Extreme Conditions and School of Engineering, University of Edinburgh, Edinburgh EH9 3FD (United Kingdom)
2016-08-15
Ultrasonic techniques such as pulse echo, vibrating reed, or resonant ultrasound spectroscopy are powerful probes not only for studying elasticity but also for investigating electronic and magnetic properties. Here, we report on the design of a high pressure ultrasonic pulse echo apparatus, based on a piston cylinder cell, with a simplified electronic setup that operates with a single coaxial cable and requires sample lengths of mm only. The design allows simultaneous measurements of ultrasonic velocities and attenuation coefficients up to a pressure of 1.5 GPa. We illustrate the performance of the cell by probing the phase diagram of a single crystal of the ferromagnetic superconductor UGe{sub 2}.
Osteosinteza pertrohantemih prijeloma u starijih osoba metodom po Enderu
Antoljak, Tomislav; Turčić, Josip; Davila, Slavko; Livaković, Mirko; Kovač, Tomo
2000-01-01
Pertrohantemi prijelomi najčešće pogađaju osobe u starijoj životnoj dobi. Uzrok je većinom pad kod kuće kao posljedica mišićne diskoordinacije, uznapredovale osteoporoze, ateroskleroze i drugih kroničnih bolesti. Operacijsko liječenje ovih prijeloma posve je opravdano pa se u literaturi predlaže niz kirurških metoda stabilizacije. U ovom su radu prikazane indikacije, kontraindikacije i komplikacije za primjenu Enderovih čavala, te standardna tablica za procjenu postoperacijskih rezultata. Pre...
Yummy Mummy – et forskningsprojekt om konstruktioner af kropsidentitet efter en fødsel
DEFF Research Database (Denmark)
Prinds, Christina Lange; Folmann, Birgitte; Nikolajsen, Helene
2015-01-01
“... those extra pounds make you sexyyou don't have to look like Beyonce, test me”. Sådan lød en tekstbid fra Phlake i P3’s “ugens uundgåelige” i uge 39 denne sensommer. Phlake hylder, med et solidt R&B beat, i hittet “Pregnant” hans kærestes gravide krop OG den særprægede længsel efter Oreos og...
Zeba, Martina; Jovanov-Milošević, Nataša; Petanjek, Zdravko
2008-01-01
Istraživanja mozga u primata ukazala su na dominantnu ulogu kortiko-kortikalnih piramidnih neurona IIIc sloja u neurobiologiji spoznajnih funkcija. U ovom radu prikazujemo rezultate usporedbene kvantitativne analize morfologije dendritičkog stabla najvećih neurona sloja IIIc impregniranih Golgi metodom, između tri različite Brodmannove areje (BA) frontalnog režnja mozga odraslog čovjeka: primarna motorna BA4, asocijativna magnopiramidalna BA9, te obostrano, govorna Brocina BA45. Statističkom ...
Prikladnost metode spontanog emulgiranja u izradi nanoemulzija za oftalmičku primjenu
Pintur, Matej
2017-01-01
Nanoemulzije predstavljaju relativno nov terpaijski sustav s nekoliko prednosti u usporedbi s klasičnim terpijskim oblicima. Naročito su zanimljivi kao topikalni oftalmički oblici jer omogućuju bolju apsorpciju lijeka kroz barijere oka. Pripravljeno je nekoliko nanoemulzija različitih sastava metodom spontanog emulgiranja te im je ispitana veličina čestica, indeks polidisperznosti i zeta potencijal. Najbolja svojstva pokazale su nanoemulzije kod kojih je kao surfaktant korišten Cremophor EL, ...
Nalaz tombusvirusa na vrsti Erigeron canadensis L.
Jeknić, Zoran; Erić, Živojin; Grbelja, Julijana
1988-01-01
Iz listova zaraženih primjeraka korovne biljke Erigeron canadensis L. koji su rasli na nekoliko lokaliteta u Sarajevu izoliran je virus iz skupine tombusvirusi. Identifikacija virusa izvršena je na osnovi reakcije pokusnih biljaka, analize ultratankih presjeka kroz zaraženo tkivo, morfologije i veličine virusnih čestica, te na osnovi seroloških reakcija metodom dvostruke imunodifuzije u agarskom gelu i čvrsto fazne imunoelektronske mikroskopije (SPIEM). U serološkim pokusima upotrijebljen je ...
Energy Technology Data Exchange (ETDEWEB)
Anfinogenov, V B; Gulyaev, Yu V; Zil' berman, P E; Kotelyanskij, I M; Polzikova, N I; Sukhanov, A A [AN SSSR, Moscow (USSR). Inst. Radiotekhniki i Ehlektroniki
1989-07-26
Conditions for magneto-static wave (MSW) propagation in laminar structures ferrite-high-temperature superconductor (YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}) and effect of transition into superconducting state under the temperature drop on these conditions are investigated. MSW electron absorption effrect in such structures (strongly dependent on the temperature) is detected and its interpretation is given.
User-Generated Social Media Events in Tourism
Mariné Roig, Estela; Martín Fuentes, Eva; Daries Ramón, Natalia
2017-01-01
Social media and mobile technologies have revolutionised communication and particular attention has been given to user-generated content (UGC) and the formation of online communities; however, little attention has been given to tourist events entirely generated by users through social media. This paper aims to define and characterise the phenomenon of tourism user-generated events (UGEs) through social media around the user's new empowered role and to assess user-generated social media events...
International Nuclear Information System (INIS)
Haga, Yoshinori; Sakai, Hironori; Kambe, Shinsaku
2007-01-01
Recent advances in the understanding of the 5f-relevant electronic states and unconventional superconducting properties are reviewed in actinide compounds of UPd 2 Al 3 . UPt 3 , URu 2 Si 2 , UGe 2 , and PuRhGa 5 . These are based on the experimental results carried out on high-quality single crystal samples, including transuranium compounds, which were grown by using combined techniques. The paring state and the gap structure of these superconductors are discussed, especially for the corresponding Fermi surfaces which were clarified by the de Haas-van Alphen experiment and the energy band calculations. A detailed systematic study using the NQR/NMR spectroscopy reveals the d-wave superconductivity in PuRhGa 5 and the difference of magnetic excitations due to the difference of ground states in U-, Np-, and Pu-based AnTGa 5 (T: transition metal) compounds. (author)
HPLC određivanje sfingozina i sfinganina u serumu kao potencijalnih biomarkera metaboličkog sindroma
Križanac, Andrea
2016-01-01
U ovom radu provedeno je određivanje koncentracije C18 sfingozina i C18-DL-erythrosfinganina ekstrahiranih iz uzoraka seruma zdravih ispitanika i ispitanika s dijagnosticiranim metaboličkim sindromom. Cilj rada je bio utvrditi mogu li navedene sfingoidne baze poslužiti kao specifični biomarkeri metaboličkog sindroma. Provedena je ekstrakcija ukupnih sfingolipida nakon čega su sfingoidne baze, C18 sfingozin i C18-DL-erythro-sfinganin, oslobođene iz kompleksnih sfingolipida metodom kisele hidr...
Stavovi hrvatskih građana prema kulturnim različitostima
Mesić, Milan; Bagić, Dragan
2011-01-01
Članak se temelji na dijelu rezultata reprezentativnoga nacionalnog ispitivanja stavova hrvatskih građana o kulturnim različitostima u hrvatskome društvu. Terensko anketiranje provedeno je metodom osobnog intervjua u kućanstvu ispitanika, u okviru omnibus istraživanja. Pod kulturnim različitostima autori misle na nacionalne manjine i vjerske zajednice. U tom smislu Hrvatska je, poput većine zemalja suvremenoga svijeta, kulturno heterogena politička zajednica. Stoga će odnos njezinih građana p...
Bakteriološka zagađenost alginatnih otisaka i dimenzionalna stabilnost pri dezinfekciji
Broz, Mira; Romić, Željko; Omrčen, Ante; Fridrih, Sandra; Ropac, Darko
1989-01-01
Istraživanje mikrobiološke zagađenosti alginatnih otisaka nametnulo je potrebu primjene dezinficijensa prije slanja otisaka u laboratorij. Kao praktično zadovoljavajuće pokazalo se petminutno potapanje otisaka u razrjeđenju od 1:50 klorheksidin-glukonata. Postavljen je problem točnosti uzetog otiska nakon dezinfekcije s obzirom na mogućnost utjecaja dezinfeciejnsa na volumen otiska. Originalnom metodom mjerenja otisne mase dokazano je da promjena volumena i površine alginata nije značajna te ...
Sulejmanagić, Halid; Galić, Miroslav; Jadrić, Stjepko
1986-01-01
Cilj ovoga rada bio je metodom elektroforeze na poliakrilamidnom gelu izdiferencirati pojedine izoenzime laktatdehidrogenaze iz uzoraka sadržaja radikularnih cista te pri tome ispitati postojanje korelacije između izoenzimatskog spektra sadržaja sa citološkom i mikrobiološkom analizom istog. Cjelokupna istraživanja su urađena na 9 uzoraka. Biokemijski dio uređen je na Institutu za biohemiju po metodi Bloemendaala, citološki na Institutu za patologiju, a mikrobiološki u specijalističkom labora...
urf e meteorologi l instrument tion for fyfwi
Indian Academy of Sciences (India)
g uge on o rd the shipAF prom t les P nd Q we see th t y nd l rgeD the slow sensors sele ted for fyfwi re the s me s those used in the swi system ex ept the humidity sensorF sn the swi. systemD otroni s humidity sensor is used long with w oung r di tion shield where s in the fyfwi set upD w oung humidity sensor with w oung.
Study of dinosaur's egg shell by EPR method; Issledovaniya metodom EhPR skorlupy yaits dinozavrov
Energy Technology Data Exchange (ETDEWEB)
Tleuberdina, R A; Nasirov, R N
1998-07-01
Two varieties of calcium carbonate are defined on base of ESR spectra radiation-inducted signals containing in mollusc shell and dinosaur and ostrich egg shell; their spectral characters are studied by infrared-spectroscopy methods and X-ray analysis. Possibility of correlation between ESR signals intensity of CO{sub 2}-radical of investigated object and geological age is determined. (author)
DEFF Research Database (Denmark)
Rangvid, Jesper
2014-01-01
I forrige uge indgik EU-kommissionen og EU-Parlamentet en aftale om en fælles afviklingsmekanisme i bank-unionen (Single Resolution Mechanism; SRM). ... Så på trods af mere kapital, nye bail-in regler og afviklingsfonden tror jeg ikke, at det kan udelukkes, at fremtidige "bankredninger" kan...... nødvendigøre statslige midler. Hertil er fonden trods alt for begrænset. ... Proceduren er, at ECB indstiller til SRM's bestyrelse, at en bank skal afvikles, hvorefter EU-kommissionen og nationale tilsynsmyndigheder involveres....
Interpretation of the optical absorption spectrum of uranium germanate
International Nuclear Information System (INIS)
Gajek, Z.; Krupa, J.C.
1993-01-01
Visible and infrared absorption spectra of U 4+ in UGeO 4 are described and interpreted in terms of the standard parametrization scheme. One of the two models considered is consistent with available interpretations of other uranium germanates and silicates. The second one originating from theoretical estimation of the crystal-field effect permits exceptional properties of the compound under consideration, in particular, an untypical assignation of the electronic energy levels and values of the crystal-field parameters in comparison with other tetragonal oxides. (author)
Interpretation of the optical absorption spectrum of uranium germanate
Energy Technology Data Exchange (ETDEWEB)
Gajek, Z.; Krupa, J.C. (Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire); Zolnierek, Z. (Polska Akademia Nauk, Wroclaw (Poland). Inst. Niskich Temperatur i Badan Strukturalnych); Antic-Fidancev, E.; Lamaitre-Blaise, M. (Centre National de la Recherche Scientifique (CNRS), 92 - Meudon-Bellevue (France))
1993-12-06
Visible and infrared absorption spectra of U[sup 4+] in UGeO[sub 4] are described and interpreted in terms of the standard parametrization scheme. One of the two models considered is consistent with available interpretations of other uranium germanates and silicates. The second one originating from theoretical estimation of the crystal-field effect permits exceptional properties of the compound under consideration, in particular, an untypical assignation of the electronic energy levels and values of the crystal-field parameters in comparison with other tetragonal oxides. (author).
Directory of Open Access Journals (Sweden)
Schmid-Tannwald, Ingolf
2008-02-01
Full Text Available [english] The inadequacy of the current model of reproduction in mammals and vertebrates and the "need for a new model of man" becomes evident as soon as the relations and interactions of heterosexual partners within their living conditions are concerned. In contrast to animals hu-mans constitute an everyday life by interpersonal (social actions. Here at first the biological processes are triggered bringing humans as unique interpersonal and biological realites into existence at the moment of fertilisation. This twofold reality may be integrated into a more comprehensive scientific model of man by means of general system theory and semiotics rep-resenting human life as a flow of signs through various sign systems.[german] Jeder Mensch ist das Ergebnis eines zwischenmenschlichen Handelns in der menschlichen Sozialwelt der dort in Gang gesetzten biologischen Prozesse. Letztere sind für den Menschen und andere Säuge- und Wirbeltieren prinzipiell gleicher maßen gültig und im gängigen naturwissenschaftlichen Fortpflanzungsmodell beschrieben. Aber das naturwissenschaftliche Modell kann dieses gewissermaßen zweifache Werden des Menschen nicht angemessen repräsentieren. Dies wäre nur dann der Fall, wenn die menschlichen Beziehungen in der Sozialwelt identisch oder zumindest sehr ähnlich wären, wie die Lebensumstände der nichtmenschlichen Säuge- und Wirbeltiere, in denen sie ihre Nachkommen hervorbringen. Dann würde sich der Unterschied zwischen dem Werden des Menschen und jenem der anderen Säuge- und Wirbeltiere auf die biologischen Fakten beschränken und diese wären mit dem Fortpflanzungsmodell hinreichend beschrieben. Die Voraussetzung gleicher Lebenswelten bei Mensch und Tier trifft aber nicht zu. Deshalb stellt das Fortpflanzungsmodell eine Verfremdung des Phänomens „Mensch“ dar, noch dazu eine folgenschwere, vor allem am Lebensanfang, da Modelle als Bilder unser Handeln im Alltag leiten, vor allem, wenn sie
Kontext+7, Lærervejledning og web
DEFF Research Database (Denmark)
Hansen, Niels Jacob; Johnsen, Lars Busch; Lindhardt, Bent Kofod
KonteXt+7 Lærervejledning/Web består af en trykt lærervejledning og et tilhørende website: kontextplus.dk. Lærervejledningen indeholder en didaktisk del, en side til side-vejledning og en evalueringsdel. Web-delen indeholder arbejdsark, hjælpeark, serviceark og evalueringsark til hvert kapitel til...... i matematik KonteXt + 7, Kernebog/Web er klar på lager første uge i august. De to første kapitler vil blive lagt på kontextplus.dk, så du har mulighed for at forberede din undervisning i god tid....
Rieg, Timo; Masuda, Takahiro; Gerasimova, Maria; Mayoux, Eric; Platt, Kenneth; Powell, David R.; Thomson, Scott C.; Koepsell, Hermann
2013-01-01
In the kidney, the sodium-glucose cotransporters SGLT2 and SGLT1 are thought to account for >90 and ∼3% of fractional glucose reabsorption (FGR), respectively. However, euglycemic humans treated with an SGLT2 inhibitor maintain an FGR of 40–50%, mimicking values in Sglt2 knockout mice. Here, we show that oral gavage with a selective SGLT2 inhibitor (SGLT2-I) dose dependently increased urinary glucose excretion (UGE) in wild-type (WT) mice. The dose-response curve was shifted leftward and the maximum response doubled in Sglt1 knockout (Sglt1−/−) mice. Treatment in diet with the SGLT2-I for 3 wk maintained 1.5- to 2-fold higher urine glucose/creatinine ratios in Sglt1−/− vs. WT mice, associated with a temporarily greater reduction in blood glucose in Sglt1−/− vs. WT after 24 h (−33 vs. −11%). Subsequent inulin clearance studies under anesthesia revealed free plasma concentrations of the SGLT2-I (corresponding to early proximal concentration) close to the reported IC50 for SGLT2 in mice, which were associated with FGR of 64 ± 2% in WT and 17 ± 2% in Sglt1−/−. Additional intraperitoneal application of the SGLT2-I (maximum effective dose in metabolic cages) increased free plasma concentrations ∼10-fold and reduced FGR to 44 ± 3% in WT and to −1 ± 3% in Sglt1−/−. The absence of renal glucose reabsorption was confirmed in male and female Sglt1/Sglt2 double knockout mice. In conclusion, SGLT2 and SGLT1 account for renal glucose reabsorption in euglycemia, with 97 and 3% being reabsorbed by SGLT2 and SGLT1, respectively. When SGLT2 is fully inhibited by SGLT2-I, the increase in SGLT1-mediated glucose reabsorption explains why only 50–60% of filtered glucose is excreted. PMID:24226519
What is new in the world of superconductors?
International Nuclear Information System (INIS)
Das, M.P.
2002-01-01
Full text: Ever since its discovery in 1911 by Heike Kamerlingh-Onnes in Leiden, superconductivity has promised tantalising possibilities of widespread applications. After 1986 its occurrence in cuprates above the liquid nitrogen temperature reaffirmed its capabilities for very many practical uses. More recently a number of novel materials namely intercalated fullerenes (C-60) and n-cenes (anthra-cene, tetra-cene and penta-cenes), a simple bimetallic alloy (MgB2), and ferromagnetic materials under high pressure including Fe, ZrZn2, and UGe2 have surprised us with their peculiar superconducting properties. In this talk I shall give a pedagogic survey of some of our current understanding- how these novel materials superconduct. I shall highlight a host of observable anomalies associated with these superconductors and discuss if their occurrence throws any light on the microscopic understanding of the superconducting phenomenon. I shall illustrate with a number of practical applications accomplished to date
Performance evaluation of small wind turbines for off grid applications in Saudi Arabia
International Nuclear Information System (INIS)
Al-Hadhrami, Luai M.
2014-01-01
Highlights: • Sixteen HAWT and 8 VAWT performance evaluations for s wind measurement site. • HAWT were found to be more efficient than VAWT. • Higher energy yields during high load demands. • PCF’s of up to 54% could be achieved. • Highest energy increase for hub height change from 20 to 30 m. - Abstract: The study evaluated the energy output and plant capacity factor (PCF) of small wind turbines in the category of 1–3 kW, 5–10 kW, 15–20 kW and 50–80 kW rated powers. Furthermore, the effect of hub height on energy output and the PCF has been studied to recommend suitable hub height for different type of applications and load requirements. To achieve the set objectives, hourly average wind speed data measured at 10, 20, 30, and 40 m and wind direction at 30 and 40 m above ground level during July 01, 2006 to July 10, 2008 has been utilized. Highest percentage change in annual energy yield (AEY) was obtained for an increase in hub height of 10 m from 20 to 30 m for both horizontal and vertical wind turbines chosen in the present study. The next best AEY was obtained while increasing hub height from 10 to 15 m. Horizontal axis wind turbines Fortis Passat with PCF of 44.4% at 15 m hub height, Aeolos-H 5 kW with PCF of 20% at 20 m hub height, and CF6e with PCF of 32.5% at 20 m hub height are recommended for different load requirements. Similarly, vertical axis wind turbines UGE Vision 2 kW with PCF of 8.9% at 15 m hub height, Aeolos-V-2 5 kW with PCF of 20.6% at 20 m hub height, and UGE-9M 10 kW with PCF of 14.2% at 30 m hub height are also recommended for various ranges of loads. Horizontal axis wind turbines were found generally more efficient than the vertical axis wind turbines in the present case
Directory of Open Access Journals (Sweden)
Avinash Supe
2014-01-01
Full Text Available Background and Objectives: A novel lozenge formulation with advantages of ease of drug administration, palatable taste and improved patient compliance could be the preferred mode of topical pharyngeal anesthesia during upper gastrointestinal endoscopy (UGE. This randomized, open-label, active-controlled study was conducted to evaluate the efficacy and safety of lidocaine lozenges versus lidocaine spray in the diagnostic gastroduodenal endoscopy in Indian patients. Subjects and Methods: Two hundred and forty-seven patients of either sex (18-80 years undergoing diagnostic gastroduodenal endoscopy were randomized either to; lidocaine lozenge 200 mg or lidocaine spray 200 mg to be applied as a single dose before gastroduodenal endoscopy. Ease of procedure, level of gag reflex, ease of application of the local anesthetic, and investigators global assessment were the primary efficacy endpoints. Need for rescue medication and patient′s global assessment were secondary efficacy endpoints. The incidence of any adverse event was the safety endpoint. Between groups, comparison was done by using appropriate statistical test. Results: Investigator reported significantly lesser procedural difficulty (P = 0.0007 and suppressed gag reflex (P < 0.0001 during UGE with lidocaine lozenge compared to spray. Ease of application of local anesthetic was reported easy in significantly more patients as compared with lidocaine spray (P = 0.001. Global assessment by patient and physician was favorable toward lozenge. Incidences of adverse events were similar in both the groups. Conclusions: The study suggests that lidocaine lozenges are an easier way of applying local oropharyngeal anesthesia, produces better suppression of gag reflex and makes the procedure easier when compared with lidocaine spray.
Itinerant f-electron behavior in Ce and U compounds
International Nuclear Information System (INIS)
Crabtree, G.W.
1985-04-01
The experimentally observed Fermi surface properties in URh 3 , UIr 3 , UGe 3 , CeSn 3 , CeB 6 , U 3 As 4 , U 3 P 4 , and CeSb are reviewed. For the compounds with no magnetic order, band structure models of the Fermi surface geometry are confirmed and f-ligand hybridization is found to be dominant. For CeB 6 , U 3 As 4 , and U 3 P 4 the experiments show that both local moments and f hybridization are important. In CeSb new data can be explained by a purely local model with no f-hybridization
Energy Technology Data Exchange (ETDEWEB)
Rojter, V A; Stukanovskaya, N A; Kornejchuk, G P
1962-03-15
sostoyanii ravnovesiya. Issledovanie provodilos' tsirkulyatsionnym metodom. Posle ustanovleniya ravnovesiya v sistemu vvodilos' v kachestve metki maloe kolichestvo S{sup 35}O{sub 2} i izmeryalas' skorost' perekhoda ego v S{sup 35}O{sub 3}. Iz ehtoj skorosti vychislyalas' skorost' pryamogo i obratnogo protsessov okisleniya SO{sub 2} na katalizatore. Predlozheny i obsuzhdeny vozmozhnye skhemy protekaniya protsessa. (author)
Directory of Open Access Journals (Sweden)
Miloš Z. Petrović
2014-10-01
Full Text Available U radu je prikazano delovanje sile prednaprezanja na armiranobetonski ram (u daljem tekstu AB ram. Posmatrani sistem je statički neodređen sa dva ukleštenja. Na njega deluje opterećenje prednaprezanje kablom silom Nk=600 kN, kao i sopstveno opterećenje. Visina rama je 6.00 m, a osovinski razmak 20.00 m. Opterećenje od sopstvene težine elemenata je od rigle i stuba. Opterećenje konstrukcije usled prednaprezanja spada u unutrašnja opterećenja, koja zamenjujemo ekvivalentnim opterećenjem koje predstavlja spoljašnje opterećenje. Proračun je izvršen metodom sila i metodom deformacija, kao i u softverskom programu 'Tower'. Metodom sila se uklanja ukleštenje i preseku se omogućava obrtanje. Statički neodređena veličina tada je moment ukleštenja. Kod metode deformacije sve statičke i deformacijske veličine izražavaju se putem izvesnog broja međusobno nezavisnih deformacijskih veličina, koje su određene iz uslova ravnoteže sistema. Broj nezavisnih deformacijskih neodređenih veličina predstavlja deformacijsku neodređenost nosača. Sve deformacijski neodređene veličine mogu se svrstati u dve grupe: prvu grupu čine uglovi obrtanja na krajevima kruto vezanih štapova, a drugu grupu komponente pomeranja čvorova. / The effects of prestressing forces on a reinforced concrete frame are shown in the paper. The structure is a statically indeterminate frame with two fixed supports. The load is due to tendon prestressing with Nk = 600 kN and due to self-weight of columns and beam. The columns height is 6.00 m and the beam span is 20.00 m. Effects of prestressing can be replaced by an external equivalent load. Calculations are performed by the force method, by the direct stiffness method and using the 'Tower' software. The rotational restraints are released at fixed supports and the restraint moments are calculated by the force method. The direct stiffness method uses the members' stiffness relations for computing member forces and
High pressure apparatus for neutron scattering at low temperature
International Nuclear Information System (INIS)
Munakata, Koji; Uwatoko, Yoshiya; Aso, Naofumi
2010-01-01
Effects of pressure on the physical properties are very important for understanding highly correlated electron systems, in which pressure-induced attractive phenomena such as superconductivity and magnetically ordered non-Fermi liquid have been observed. Up to now, many scientists have developed a lot of high pressure apparatus for each purpose. The characteristic features of various materials and pressure transmitting media for use of high pressure apparatus are reported. Then, two kinds of clamp type high-pressure cell designed for low-temperature neutron diffraction measurements are shown; one is a piston cylinder type high-pressure cell which can be attached to the dilution refrigerator, and the other one is a newly-developed cubic anvil type high-pressure cell which can generate pressure above 7GPa. We also introduce the results of magnetic neutron scattering under pressure on a pressure-induced superconducting ferromagnet UGe 2 in use of the piston cylinder type clamp cell, and those on an iron arsenide superconductor SrFe 2 As 2 in use of the cubic anvil type clamp cell. (author)
Proračun optimalnog perioda zamjene brodske opreme metodom statističkog modeliranja
Directory of Open Access Journals (Sweden)
Ivan Mavrić
2012-10-01
Full Text Available The article deals with the problem of assessing the optimalvolume and period for the replacement of ship equipment. Theintroduction analyses the character and the volume of technicalmaintenance and the repair of the ship equipment, certainassemblies and elements of that equipment. Possible tasks andvarious ways in which they can be solved are defined. The statisticalmodelling of random processes is particularly stressed.Eventually, the numerical example of statistical modelling oftechnical maintenance and the assessment of the optimal replacementperiod of the ship pump bearing is given.
Udvikling af antistoffer efter vaccination mod og podning med PRRSV
DEFF Research Database (Denmark)
Sonne Kristensen, Charlotte; Qvist Pawlowski, Mia; Thoning, Henrik
konkludere, at det er muligt at vaccinere med begge PRRS vacciner på samme tid og opnå antistofsvar for begge typer PRRSV. Husk dog altid at give forskellige vacciner i hver sin side af nakken. Blodprøver fra grisene viste, at de havde dannet antistoffer og blev positive i ELISA-testen for PRRSV Type 1 21......-US samt IPT testene. Disse tests kan dog ikke skelne ”eksotiske” PRRSV subtyper fra de almindelige cirkulerende PRRSV subtyper i Danmark. Forsøget blev gennemført på Lindholm. Der indgik 66 grise fra en Blå SPF+Ap6+Ap12 besætning. Grisene blev ved ankomst fordelt i 4 grupper (VAC-T1, VAC-T2, VAC-T1T2 og...... NON-VAC): VAC-T1 blev vaccineret med Porcilis ® PRRS VET VAC-T2 blev vaccineret med Ingelvac ® PRRS VET VAC-T1T2 fik begge vacciner samtidig i hver sin side af nakken NON-VAC blev ikke vaccineret. Grisene blev gennem hele forsøget observeret dagligt. De fik taget temperatur den første uge efter...
Optical absorption spectra of the uranium (4+) ion in the thorium germanate matrix
Energy Technology Data Exchange (ETDEWEB)
Gajek, Z. [W Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wroclaw, PO Box 937 (Poland); Krupa, J.C. [Laboratoire de Radiochimie, Institut de Physique Nucleaire, BP 1, 91406 Orsay Cedex (France); Antic-Fidancev, E. [Unite P- de Recherche associee au CNRS 210, 1 place A Briand, 92195 Meudon Cedex (France)
1997-01-13
Visible and infrared absorption measurements on the U{sup 4+} ion in tetragonal zircon-type matrix {beta}-ThGeO{sub 4} are reported and analysed in terms of the standard parametrization scheme. The observed 17 main peaks and a number of less intense lines have been assigned and fitted to most of the 32 allowed electric dipole transitions with the root mean square error equal to 65 cm{sup -1}. The free-ion parameters obtained for the model Hamiltonian, {zeta}5f = 1809 cm{sup -1}, F{sup 2}=43 065 cm{sup -1}, F{sup 4}=38 977 cm{sup -1} and F{sup 6}=24 391 cm{sup -1}, as well as the corresponding crystal-field parameters, B{sub 0}{sup 2}=-1790 cm{sup -1}, B{sub 0}{sup 4}=1200 cm{sup -1}, B{sub 4}{sup 4}=3260 cm{sup -1}, B{sub 0}{sup 6}=-3170 cm{sup -1} and B{sub 4}{sup 6}=990 cm{sup -1}, agree fairly well with the initial theoretical estimations. The results are discussed in relation to the previous spectroscopic study on the scheelite-type matrix UGeO{sub 4}. (author)
Superconductivity: Is there a problem in transuranics?
International Nuclear Information System (INIS)
Colineau, Eric; Griveau, Jean-Christophe; Eloirdi, Rachel; Hen, Amir; Caciuffo, Roberto
2014-01-01
Superconductivity was first reported in 1942 for uranium metal (¡-U) and in 1958 for U compounds: UCo, U6Mn, U6Fe, and U6Co, with critical temperatures Tc, of 1.7, 2.3, 3.9, and 2.3K, respectively. A new class of U superconductors emerged in the early 1980’s with the discovery of U heavy fermion superconductors : UBe13 (Tc = 0.85K), UPt3 (Tc = 0.53K), URu2Si2 (Tc = 1.5K) , UPd2Al3 (Tc = 1.9K) … Furthermore, in most of these systems, the superconducting phases coexist with antiferromagnetic (AF) correlations which have characteristic temperatures, usually the Néel temperature TN, that are typically one order of magnitude greater than the corresponding superconducting critical temperatures Tc. Superconductivity was even shown to co-exist with ferromagnetism in e.g. UGe2 (Tc ï» 0.8K, TC ï» 30K at p ï» 1.2GPa) and URhGe (Tc = 0.25K, TC = 9.5K). Heavy fermion superconductors still remain a major challenge for condensed matter physics. The existence of heavy fermion superconductivity and its coexistence or proximity with magnetic order suggests that the conventional mechanism of phonon-mediated superconductivity is inappropriate and that alternative mechanisms, like spin fluctuations, should be considered for Cooper pairing
A Bubble-Based Drag Model at the Local-Grid Level for Eulerian Simulation of Bubbling Fluidized Beds
Directory of Open Access Journals (Sweden)
Kun Hong
2016-01-01
Full Text Available A bubble-based drag model at the local-grid level is proposed to simulate gas-solid flows in bubbling fluidized beds of Geldart A particles. In this model, five balance equations are derived from the mass and the momentum conservation. This set of equations along with necessary correlations for bubble diameter and voidage of emulsion phase is solved to obtain seven local structural parameters (uge, upe, εe, δb, ub, db, and ab which describe heterogeneous flows of bubbling fluidized beds. The modified drag coefficient obtained from the above-mentioned structural parameters is then incorporated into the two-fluid model to simulate the hydrodynamics of Geldart A particles in a lab-scale bubbling fluidized bed. The comparison between experimental and simulation results for the axial and radial solids concentration profiles is promising.
Directory of Open Access Journals (Sweden)
Miljko M. Erić
2002-01-01
Full Text Available Analiziran je problem procene smera dolaska radio-signala metodom MUSIC korišćenjem antenskih nizova ADCOCK. Formulisan je matematički model signala na antenskom nizu ADCOCK. Izvedene su relacije između vektora prostiranja ADCOCK i vektora prostiranja ukupnog antenskog niza (niza od koga se ADCOCK-ov niz formira. Definisana je kriterijumska funkcija algoritma MUSIC i funkcija neodređenosti antenskog niza ADCOCK. Prikazani su rezultati simulacije, kao i rezultati praktične verifikacije mogućnosti primene metode MUSIC na antenske nizove ADCOCK. / The MUSIC based Direction of Arrival estimation using the ADCOCK antenna arrays is considered. Starting from signal model formulation, the cost function of the MUSIC algorithm and the ambiguity functions for the ADCOCK antenna array have been formulated. Some simulation results and some preliminary results of the verification in practice are presented.
Optical absorption spectra of the uranium (4+) ion in the thorium germanate matrix
Gajek, Z; Antic-Fidancev, E
1997-01-01
Visible and infrared absorption measurements on the U sup 4 sup + ion in tetragonal zircon-type matrix beta-ThGeO sub 4 are reported and analysed in terms of the standard parametrization scheme. The observed 17 main peaks and a number of less intense lines have been assigned and fitted to most of the 32 allowed electric dipole transitions with the root mean square error equal to 65 cm sup - sup 1. The free-ion parameters obtained for the model Hamiltonian, zeta 5f = 1809 cm sup - sup 1 , F sup 2 =43 065 cm sup - sup 1 , F sup 4 =38 977 cm sup - sup 1 and F sup 6 =24 391 cm sup - sup 1 , as well as the corresponding crystal-field parameters, B sub 0 sup 2 =-1790 cm sup - sup 1 , B sub 0 sup 4 =1200 cm sup - sup 1 , B sub 4 sup 4 =3260 cm sup - sup 1 , B sub 0 sup 6 =-3170 cm sup - sup 1 and B sub 4 sup 6 =990 cm sup - sup 1 , agree fairly well with the initial theoretical estimations. The results are discussed in relation to the previous spectroscopic study on the scheelite-type matrix UGeO sub 4. (author)
Energy Technology Data Exchange (ETDEWEB)
Konstantinov, A. A.; Sazonova, T. E. [Vsesojuznyj Nauchno - Isledovatel' skij Institut Im. D.I. Mendeleeva, Leningrad, SSSR (Russian Federation)
1967-03-15
To obtain a high degree of accuracy in determining the specific activity of sources by the absolute counting of particles with a 4{pi} counter, attention must be paid to the preparation of the radioactive sources. At the Mendeleev Institute of Metrology, celluloid films (surface density 8-10 {mu}/cm{sup 2}) coated on both sides with gold (10-15 {mu}g/cm{sup 2} ) or palladium (5-6 {mu}g/cm{sup 2}) are used as the bases of the radioactive sources. In order to reduce the correction for absorption of beta particles in the radioactive deposit, the base is specially treated with insulin. The authors present an extremely sensitive and effective method, employing the electron-capture nuclide {sup 54}Mn ({sup 54}Cr), for determining the uniform distribution of the active layer over the entire insulintreated surface. A solution of {sup 54}Mn ({sup 54}Cr) salt was applied to the insulin-tteated film, and the source of {sup 54}Cr ({sup 54}Mn) Auger K electrons thus obtained was investigated with the help of a proportional 4{pi} counter. The total number of {sup 54}Cr ({sup 54}Mn) Auger K electrons from the source was 8-12% less than the fluorescence coefficient (calculated from the number of {sup 54}Cr ({sup 54}Mn) K X-quanta emitted by the source) and the number of K electrons absorbed in the film (determined by the 'sandwich' method). From the differences, for insulintreated and untreated {sup 54}Mn ({sup 54}Cr) sources, between the calculated and recorded number of Auger electrons it is possible to reach a definite conclusion regarding the quality of the insulin treatment. (author) [Russian] Dlja poluchenija vysokoj tochnosti izmerenij pri opredelenii udel'noj aktivnosti istochnikov metodom absoljutnogo scheta chastic s pomoshh'ju 4{pi}- schetchika, bol'shoe vnimanie dolzhno byt' udeleno prigotovleniju radioaktivnyh istochnikov. Vo VNIIM v kachestve podlozhek radioaktivnyh istochnikov ispol'zujutsja celluloidnye plenki (poverhnostnaja plot- nost' 8-10 mkg/sm{sup 2
Energy Technology Data Exchange (ETDEWEB)
Zado, F. [Rudjer Boskovlc Institute, Zagreb, Yugoslavia (Croatia)
1963-11-15
en raison de la sensibilite du trichlorure de bore a l'humidite. (author) [Spanish] Hasta ahora no se han publicado datos sobre la aplicacion de la cromatografia de gases a la valoracion de vestigios de boro en el grafito. El autor examina los siguientes metodos de transformacion del boro en compuestos volatiles: a) Ignicion del grafito en corriente de oxigeno y transformacion subsiguiente del acido de boro en borato de metilo volatil, que se analiza luego en un cromatografo de gases Dilkens Aerograph H, modelo 96, con columna de silicona e hidrogeno como portador (metodo de concentracion). b) Extraccion del boro presente en el grafito por medio de fluoruro de sodio a 2800{sup o}C con cloracion y retencion simultaneas del tricloruro de boro, que luego se analiza (metodo directo). El autor uso un cromatografo de gases fabricado por el mismo, con un detector de conductividad termica y nitrogeno como portador. La columna era de vidrio con 20% en peso de fluorocarburo aceitoso sobre kieselgur. En vista de la sensibilidad del tricloruro de boro frente a la humedad, fue preciso adoptar medidas de precaucion especiales. (author) [Russian] V literature otsutstvuet dannye o primenenii gazovoj khromatografii dlya analiza sledov bora v grafite. Obsukhdayutsya sleduyushchie metody prevrashcheniya bora v ego letuchie soedineniya: a) Prokalivanie grafita v potoke kisloroda s posleduyushchim prevrashcheniem okisi bora v letuchij bornometilovyj ehfir, kotoryj zatem issleduetsya metodom gazovoj khromatografii na aehrografe Dilkensa, model' H 96, s kremnievoj kolonkoj i vodorodom v kachestve nositelya (metod kontsentratsii); i b) Ehkstragirovanie bora iz grafita s pomoshch'yu ftoristogo natriya pri 2800{sup o}C s odnovremennym khlorirovaniem i ulavlivaniem trekhkhloristogo bora, kotoryj zatem podvergaetsya analizu (pryamoj metod). Ispol'zovalas' ustanovka dlya gazovoj khromatografii kustarnogo proizvodstva s teploprovodnym detektorom i azotom v kachestve nositelya. Kolonka byla
Energy Technology Data Exchange (ETDEWEB)
Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)
1970-02-15
This paper describes methods for interpretation of progressive substitution experiments for determining material buckling in homogeneous two-group approximation. These methods were applied for experiments on the zero power RB reactor in Vinca. Experiments were done on the reflected heavy water reactor core, the lattice pitch had unisotropy properties.
Energy Technology Data Exchange (ETDEWEB)
Kozlov, A G; Davydova, O V; Kargov, S I [Moskovskij Gosudarstvennyj Univ., Moscow (Russian Federation). Khimicheskij Fakul' tet
1993-08-01
Salt-free solutions of various ionic forms of polyriboguanylic acid (poly(G)) were studied by the methods of conductometry and spectroscopy of annular dichroism. The Manning approach was employed to calculate transport characteristics and structural parameters of poly(G) on the basis of spectra permit putting poly(G) salts in two groups: the first one comprising NH[sub 4][sup +]-, Rb[sup +]-, K[sup +]-, Na[sup +]-, the second one - Cs[sup +]-, and Li[sup +]-poly(G). The assumption is made that Li[sup +] and Cs[sup +] ions, bound with concrete groups of polyanion in a specific way, can promote formation of a stable structure different from the one observed in the presence of the first group counterions. 25 refs., 3 figs.
Magnetic monopole searches with the MoEDAL experiment at the LHC
Pinfold, J; Lacarrère, D; Mermod, P; Katre, A
2014-01-01
The magnetic monopole appears in theories of spontaneous ga uge symmetry breaking and its existence would explain the quantisation of electric charg e. MoEDAL is the latest approved LHC experiment, designed to search directly for monopoles. It h as now taken data for the first time. The MoEDAL detectors are based on two complementary techniq ues: nuclear-track detectors are sensitive to the high-ionisation signature expected fr om a monopole, and the new magnetic monopole trapper (MMT) relies on the stopping and trapping o f monopoles inside an aluminium array which is then analysed with a superconducting magneto meter. Preliminary results obtained with a subset of the MoEDAL MMT test array deployed in 2012 are presented, where monopoles with charge above the fundamental unit magnetic charge or ma ss above 1.5 TeV are probed for the first time at the LHC
Kvalitet u transportu robe i pošiljki / Quality of products and forwarded goods transport
Directory of Open Access Journals (Sweden)
Slavica Cvetković
2009-07-01
Full Text Available Danas je kvalitet dominantan kriterijum pri izboru isporučioca, a novi koncept kvaliteta smatra se superiornim metodom za reformu menadžmenta. Za razliku od tradicionalnog pristupa, novi koncept kvaliteta obezbeđuje povećanje prodaje uz istovremeno sniženje ukupnih troškova poslovanja. Obezbeđenje kvaliteta u skladu sa međunarodnim standardima serije ISO 9000 predstavlja uslov za nastup na svetskom tržištu i saradnju sa inostranim preduzećima. / When choosing a supplier today, a dominant criterion is quality, and a new concept of quality is said to be a superior method in the management reform. Unlike the traditional approach, the new concept of quality provides sales growth as well as a reduction in overall business expenses. Providing quality in accordance with the international standards series ISO 9000 is a condition to be fulfilled in order to enter the world market and cooperate with international companies.
Energy Technology Data Exchange (ETDEWEB)
Zhuchenko, N K; Yagud, R Z [AN SSSR, Leningrad (Russian Federation). Inst. Yadernoj Fiziki
1993-09-01
Neutron depolarization measurements in the mixed state of both high-T[sub c] and low-T[sub c] weak-link superconductors have been carried out. Samples of YBCO, BSCCO, SnMo[sub 6]S[sub 8] and 0.5 Nb-0.5 Ti of different magnetic prehistory were analyzed at temperatures T 4.2 K under applied magnetic fields II <= 16.5 kOe. We ascribe the appearance of magnetic inhomogeneities and their hysteresis behaviour to the interaction between dipole magnetic fields (diamagnetic and paramagnetic ones) and applied magnetic fields.
Energy Technology Data Exchange (ETDEWEB)
Steyn, J [National Physical Research Laboratory, Pretoria (South Africa)
1960-06-15
The accuracy of the 4 {pi} liquid scintillation counting method of standardizing {beta} emitters was compared to 4 l{pi} {beta}-{gamma} coincidence counting for the nuclides Co{sup 60}, I{sup 131} and Au{sup 198}. For P{sup 32} the liquid counting results were compared to 4 {pi} proportional counting. The efficiency of the liquid scintillation counting method was found to be energy dependent, dropping to about 97.5% for Co{sup 60} which was the lowest energy {beta} emitter investigated. (author) [French] La precision de la methode de comptage 4 {pi} a scintillateurs liquides pour l'etalonnage des emetteurs {beta} a ete comparee au comptage par coincidences 4 {pi} {beta}-{gamma} pour le So{sup 60}, le I{sup 131} et le Au{sup 198}. Dans le cas du P{sup 32}, les resultats du comptage au liquide ont ete compares a ceux du comptage 4 {pi} proportionnel. On a constate que le rendement de la methode de comptage a scintillateurs liquides variait en fonction de l'energie emise et qu'il descendait a environ 97.5% pour le Co{sup 60} qui, de tous les emetteurs {beta} etudies, emet l'energie la plus faible. (author) [Spanish] El autor compara la precision del metodo de recuento con centelleador iquido 4 {pi} para normalizar emisores {beta} con la del metodo de coincidencias {beta}-{gamma} 4 {pi}, para los siguientes nuclidos: So{sup 60}, I{sup 131} y Au{sup 198}. En el caso del P{sup 32}, confronta los resultados del primer metodo con los obtenidos mediante el recuento proporcional 4 {pi}. Comprueba que la eficacia del metodo de recuento con centelleador liquido depende de la energia y desciende al 97.5%, aproximadamente, para el Co{sup 60}, que fue el emisor {beta} mas debil que se investigo. (author) [Russian] Tochnost' 4 {pi} zhidkogo stsintillyatsionnog o metoda podscheta standartiziruemogo {beta}-izluchatelya sravnivalas' s 4 {pi} {beta}-{gamma} metodom podscheta na sovpadeniyakh dlya izotopov So{sup 60}, I{sup 131} i Au{sup 198}. Dlya R{sup 32} rezultaty zhidkogo
Helicobacteriose em leitões: imuno-histoquímica em amostras colhidas por meio de gastroscopia
Directory of Open Access Journals (Sweden)
R.L. Silveira
2014-12-01
Full Text Available O diagnóstico da úlcera gastroesofágica (UGE é fundamental para que se tente a recuperação dos afetados, entretanto há grande dificuldade na sua realização de forma precisa. Modernos endoscópios são ferramentas importantes nesse sentido e podem ser usados para determinar em que fase da criação a ulceração ocorre. A bactéria Helicobacter tem sido associada à UGE e gerado perdas econômicas. Tendo em vista que poucos trabalhos têm sido realizados para identificação do problema precocemente, este estudo teve como objetivo detectar as lesões relacionando-as, ou não, com a bactéria Helicobacter spp., mediante análises macroscópica e histopatológica de amostras colhidas por meio da gastroscopia. Foram utilizados 20 animais de ambos os sexos, pesando entre 22 e 26kg e com 65 dias de idade. O aparelho utilizado foi um gastrovideoscópio da marca Karl Storz, modelo 1380NKS. Foram colhidas amostras das regiões anatômicas aglandular (quadrilátero esofágico e glandular (cárdica, fúndica e pilórica para o teste ultrarrápido da urease e para as avaliações histopatológicas e imuno-histoquímicas. Onze animais apresentaram lesões na região aglandular à endoscopia, e microscopicamente 15 animais apresentaram paraqueratose. Em 18 animais, foram observadas alterações em pelo menos uma das três regiões glandulares. As lesões foram maiores na região cárdica, seguida da antral e da fúndica. Em relação ao teste ultrarrápido da urease, sete animais foram negativos nas quatro regiões, e 13 positivos em pelo menos uma delas. Em relação à imuno-histoquímica (IHQ, 10 animais foram negativos em todas as regiões e 10 foram positivos em pelo menos uma delas. Os achados pré-ulcerativos não demonstraram relação com o Helicobacter spp., que apresenta caráter saprofítico e oportunista confirmado pela sua imunomarcação em áreas sem lesão.
Energy Technology Data Exchange (ETDEWEB)
Afgan, N; Kulundzic, P [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)
1964-06-15
The objective of this work was to determine the maximum time interval without accident due to mechanical failures. The following accidents caused by mechanical failures are taken into account: loss of moderator flow, moderator leaking with or without circulation, and accidents caused by removal of fuel channels from the reactor vessel. Obtained numerical and experimental results are presented. Experimental device installed at the reactor was used for verification of calculation results. The analysis was done for the most damaging conditions and thus the obtained results represent the lowest boundary values. [Serbo-Croat] Rad je baziran na pronalazenju maksimalnih vremena pri kojima i pored mehanickih kvarova nece doci do udesa. Posmatrani su slucajevi: prestanak cirkulacije moderatora, curenje moderatora uz i bez postojece cirkulacije, kao i udesi pri vadjenju tehnoloskih kanala iz reaktorskog suda. Dobijeni su rezultati numerickom i eksperimentalnom metodom. Eksperimentalna aparatura je postavljena da bi se dobila potvrda numerickih rezultata. U radu se vodilo racuna da se uvek analiziraju najnepovoljniji slucajevi pa su zato i dobijeni rezultati donje granice resenja (author)
International Nuclear Information System (INIS)
Antonov, V.N.; Shpak, A.P.; Yares'ko, A.N.
2008-01-01
The present state of theoretical understanding of the x-ray magnetic circular dichroism (XMCD) of 4f and 5f compounds is reviewed. Energy band theory based upon the local spin-density approximation (LSDA) describes the XMCD spectra of transition metal compounds with high accuracy. However, the LSDA does not suffice for lanthanide compounds which have a correlated 4f shell. A satisfactory description of the XMCD spectra could be obtained by using a generalization of the LSDA, in which explicitly f electron Coulomb correlations are taken into account (LSDA+U approach). As examples of this group we consider the compound GdN. We also consider uranium 5f compounds. In those compounds where the 5f electrons are rather delocalized, the LSDA describes the XMCD spectra reasonably well. As an example of this group we consider UFe 2 . Particular differences occur for uranium compounds in which the 5f electrons are neither delocalized nor localized, but more or less semilocalized. Typical examples are UXAl (X=Co, Rh, and Pt), and UX (X=S, Se, Te). However, the semilocalized 5f's are not inert, but their interaction with conduction electrons plays an important role. We also consider the electronic structure and XMCD spectra of the heavy-fermion compounds UPt 3 , URu 2 Si 2 , UPd 2 Al 3 , UNi 2 Al 3 , and UBe 13 , where the degree of the 5f localization is increased in comparison with other uranium compounds. The electronic structure and XMCD spectra of UGe 2 which possesses simultaneously ferromagnetism and superconductivity also presented. Recently achieved improvements for describing 5f compounds are discussed
Energy Technology Data Exchange (ETDEWEB)
Gibbons, D; Simpson, H [Wantage Research Laboratory (A.E.R.E.), Wantage, Berks. (United Kingdom)
1962-01-15
secciones eficaces de absorcion para los neutrones rapidos son mucho mas bajas que para los lentos lo cual reduce considerablemente los errores debidos al autoblindaje. La interferencia debida a la reaccion (n, {gamma}) causada por los neutrones lentos en el fosforo natural puede eliminarse gracias a una tecnica que consiste en efectuar irradiaciones dobles en regiones del reactor en que varien las razones del flujo de neutrones lentos a neutrones rapidos. El metodo se ha aplicado a la determinacion del azufre en cromo y arsenico. (author) [Russian] Proizvodstvo radiofosfora pri vzaimodejstvii bystrykh nejtronov (n, p) s seroj ispol'zuetsya dlya opredeleniya sery s pomoshch'yu aktivatsionnogo analiza. Ispol'zovanie dannogo metoda pozvolyaet opredelit' nalichie sery v materialakh s bol'shim secheniem pogloshcheniya teplovykh nejtronov, t.k. sechenie pogloshcheniya bystrykh nejtronov, kak pravilo, znachitel'no men'she, chem medlennykh nejtronov, chto pozvolyaet zametno snizit' veroyatnost' oshibok iz-za samozashchity. Pomekhi iz-za reaktsii (n, {gamma}) na medlennykh nejtronakh s estestvennym fosforom ustranyayutsya metodom dvojnogo oblucheniya v mestakh s razlichnym otnosheniem potokov bystrykh i medlennykh nejtronov. Dannyj metod primenyalsya dlya opredeleniya sery v khrome i mysh'yake. (author)
Energy Technology Data Exchange (ETDEWEB)
Velickovic, Lj; Petrovic, M [Boris Kidric Institute of nuclear sciences Vinca, Belgrade (Yugoslavia)
1968-12-15
Stochastic reactor oscillator and cross correlation method were used for determining reactor dynamics characteristics. Experimental equipment, fast reactor oscillator (BOR-1) was activated by random pulses from the GBS-16 generator. Tape recorder AMPEX-SF-300 and data acquisition tool registered reactor response to perturbations having different frequencies. Reactor response and activation signals were cross correlated by digital computer for different positions of stochastic oscillator and ionization chamber.
Directory of Open Access Journals (Sweden)
Vladimir Vuksanović
2011-03-01
Full Text Available This particular research is analyzing the changes of the maximal muscle power in the elbow joint, as well as the anthropometrical measures and biomechanical variable. The program for exercising performed in this research has a longitudinal character with duration of 6 weeks and two check points. This program was performed on 17 adolescents. Participant had a task do power exercises on Scot’s bench, with individual weights using the matrix method (modified amplitude of movement The analyses and result from the statistical operation (ANOVA’S/MANOVA’S have shown positive changes at the participant’s maximal power (22,4%, also at the tested angular speed (70,1% as well as it has shown decreasing of the local body fat of the involved arm for 16,6% after six weeks of program. The results are in favor of the program for transformation of motorics capabilities and they are directly focused of modification of power component.
Energy Technology Data Exchange (ETDEWEB)
Radchenko, I R; Filimonova, L A [Moskovskij Inzhenerno-Fizicheskij Inst., Moscow (Russian Federation)
1993-06-01
The patterns of polarized beam interference (conoscopic patterns) enable assessment of orientation and parameters of crystal's optical indicatrix. The presented conoscopic patterns of gadolinium molybdate crystal in the vicinity to plane and wedge-live domain walls differ from conoscopic patterns of the crystals far away from these walls which allows to spear about changes occurring in the crystal in the vicinity to domain walls.
Energy Technology Data Exchange (ETDEWEB)
Krylova, A.N.
1975-01-01
A fractional method is developed for analysis of biological material for the presence of toxic quantities of Pb, Hg, Ba, Mn, Cr, Ag, Cu, Sb, Tl, As, Bi, Cd and Zn. The method satisfies the requirements of medical forensic toxicology. (Ref. Zh.)
Energy Technology Data Exchange (ETDEWEB)
Zmijarevic, I; Tomashevic, Dj [Institut za Nuklearne Nauke Boris Kidric, Belgrade (Yugoslavia)
1988-07-01
This paper presents Chebychev acceleration of outer iterations of a nodal diffusion code of high accuracy. Extrapolation parameters, unique for all moments are calculated using the node integrated distribution of fission source. Sample calculations are presented indicating the efficiency of method. (author)
Directory of Open Access Journals (Sweden)
Tadas Limba
2013-08-01
Full Text Available Nowadays e-government projects and projects in the public sector are changing the consistency and reality of our daily life and will need to be managed by project managers, who uge modern marketing tools and technologies. Social marketing is one of the modern marketing tools and, probably, it is the best tool to provide marketing in public sector project management, It has been changing in different ways since the founding of social marketing: the aim of social marketing, the technologies for using i ; but nowadays it’s hard to imagine public sector projects and, especially, egovernment projects, without using social marketing technologies. The usage of social marketing technologies can improve public sector project management and make the project more attractive to society or some part of it. This scientific paper represents social marketing transformation, the way in which social marketing needs to be used in the public sector project management process and analyses the phases of social marketing. It also gives some practical advics for public sector organizations o, how to implement social marketing in the e-government project deployment process.
Energy Technology Data Exchange (ETDEWEB)
Kostic, Lj; Petrovic, M [Boris Kidric Institute of Nuclear Sciences Vinca, Beograd (Yugoslavia)
1969-07-15
Pulse response is comprehensive description of linear system dynamics. In this paper, cross correlation method was used for measuring the response of zero power reactor. Reactor system was perturbed by pseudo-random signal, which was cross correlated with the reactor signal responding to this perturbation on the digital ZUSE Z-23 computer. Cross-correlation functions were measured for different positions of stochastic oscillator and ionization chamber in the critical system. From numerical processing of performed experimental data, it was concluded that a more powerful faster computer would be needed for processing statistical experiments. In that case it would be possible to obtain information about spatial effects in the reactor and propagation of neutron waves in the multiplication medium. Impulsni odziv je potpuni opis dinamike linearnog sistema. Za merenje impulsnog odziva nultog reaktora, u ovom radu, koriscena je kros korelaciona metoda. Reaktorski sistem je perturbovan pseudoslucajnim signalom, koji je u digitalnom racunaru ZUSE Z-23 kroskorelisan sa signalom odziva reaktora na ove perturbacije. Merene su kroskorelacione funkcije za razlicite polozaje stohastickog oscilatora i jonizacione komore u kriticnom sistemu. Iz numericki obradjivanih eksperimenta namece se kao zakljucak da bi za obradu statistickih eksperimenata kod nultih reaktora bio potreban racunar veceg kapaciteta i brzine. U tom slucaju bi se iz ovako postavljenog eksperimenta moglo doci i do informacija o prostornim efektima u reaktoru i prostiranju neutronskih talasa kroz multiplikativnu sredinu. (author)
Energy Technology Data Exchange (ETDEWEB)
Ballif, III, J. L.; Friske, W. H.; Gordon, R. B. [Atomics International, Canoga Park, California (United States)
1963-11-15
In support of the 50-MW(e) Prototype Organic Power Reactor Programme (POPR), extensive development work has been performed on aluminium powder metallurgy (ARM) products, toward their use as cladding for UO{sub 2} fuel. As part of this development work, eutectic bonding, flash butt welding, and cold-pressure welding were investigated as methods for making end closures in die fuel element cladding. Vibratory packing was studied as a means of filling APM tubes with UO{sub 2}. Out-of-pile tests were conducted to obtain information on APM-UO{sub 2} compatibility. This work revealed that, under present conditions, eutectic bonding was the most suitable method for making end closures; vibratory packing produced fuel densities in the range of 80 to 88% of theoretical density; and no APM-UO{sub 2} reaction took place in the range of POPR operating temperatures (850{sup o}F maximum fuel-cladding interface temperature). As a result o f this development work, five APM-clad UO{sub 2} prototype fuel elements have been fabricated for testing in the Organic Moderated Reactor Experiment (OMRE). Each element consisted of 24 or 25 APM-clad fuel rods, arranged in a 5 x 5 array in a nickel-plated steel or an APM fuel box. To increase surface area, the extruded APM cladding had eight fins which were spiralled to a pitch of 45 or 90e/ ft to further improve heat transfer. The fuel rod end closures were made by eutectic bonding of silver-plated aluminium end plugs to the APM tubing. The elements were instrumented to: (1) Measure cladding surface and coolant temperatures, (2) Detect fuel rod failure, (3) Change coolant velocity (means of achieving peak cladding surface temperature of 850{sup o}F), (4) Measure coolant velocity, and (5) Measure fission gas build-up. These elements have been installed in the OMRE with target fuel burn-ups of 25000 to 30000 MWd/t of uranium. As of 1 April 1963, they had achieved accumulated burn-ups ranging from 7700 to 12 000 MWd/t of uranium. Two of the
Energy Technology Data Exchange (ETDEWEB)
Petrovic, M; Markovic, V; Velickovic, Lj [Boris Kidric Institute of nuclear sciences, Vinca, Belgrade (Yugoslavia)
1963-07-01
Full text: This activity is a logical continuation of the experiment at the RA reactor during 1962 which was based on compensating the effect by means of control rod. Since results are given with significant errors, new method for measuring the absorption cross sections via reactor period. Experiment was done at the RB reactor which was particularly prepared for this type of experiments. Reactor power was from 50 mW to 2 W. Absorption cross sections were measured for two types of material: domestic graphite No.3 and French graphite 'Pachiney', and two types of aluminium. Total errors in applying this method are {+-} 5%, where the source of major part of error comes from uncertainty of the standard absorption power (previous method gave {+-} 10 do 55% ). Comparison of French graphite absorption cross section obtained via reactor period and via control rod showed approximate agreement with discrepancy of 5.4% which is considered within the precision of this method. Considering the accuracy of measurement results and reactor economy it is concluded that measuring absorption cross sections of samples via period of RB reactor is more favourable than measurements by control rod at the RA reactor. Pun tekst: Ovaj rad predstavlja logican nastavak eksperimenta na reaktoru RA u toku 1962. godine, koji je bazirao na kompenzaciji efekta pomocu kontrolne sipke. Kako su rezultati dati sa velikim greskama, to se prislo novom nacinu merenja apsorpsionih preseka preko periode reaktora. Eksperiment je radjen na reaktoru RB koji je specijalno pripremljen za ovu vrstu eksperimenta. Snaga reaktora se kretala od 50 mW do 2 W. Preko periode reaktora RB odredjeni su apsorpcioni preseci za dve vrste materijala i to: domaci grafit No.3 i francuski 'Pachiney', i dve vrste aluminijuma. Ukupne greske pri ovom nacimu merenja iznose oko {+-} 5%, gde glavni deo greske nosi neodredjenost apsorpcione moci standarda (ranija metoda je dala {+-} 10 do 55% ). Poredjenjem vrednosti apsorpcionih preseka
Energy Technology Data Exchange (ETDEWEB)
Marievskij, V F; Lejbenzon, A S
1990-10-01
Results of revealing B markers of viral hepatitis (VHB) in medical personnel in the city of Zaporozhe by radioimmunoassay method are presented. By the frequency of revealing two markers (HB {sub s}Ag and anti-HB{sub s}) risk groups are indicated depending on the profession, age (length of service) of medical personnel.
Energy Technology Data Exchange (ETDEWEB)
Petrovic, M; Markovic, V; Velickovic, Lj [Boris Kidric Institute of nuclear sciences, Vinca, Belgrade (Yugoslavia)
1963-07-01
Pulse method was applied for measuring the efficiency of control rods at the RB reactor. This paper describes the theory of experiment, experimental procedure applied and results obtained. Results are considered to be useful for safety analysis. it was found that the influence of delayed neutrons is rather small and could be neglected in estimation of rods efficiency.
Mulaomerović–Šeta, Ajla; Prskalo, Gordan; Lozančić, Željko; Petroselli, Andrea; Bakalović, Amina
2017-01-01
Problem određivanja hidrograma velikih voda jedan je od temeljnih problema u hidrotehničkoj praksi. Za definiranje hidrograma, odnosno njegovog vrha (pika), uobičajeno se koriste statističke metode godišnjih ekstrema i pikova, za koje je nužno raspolagati povijesnim podacima o protoku, zatim empirijski izrazi, te hidrološki modeli. U radu je prikazana primjena hidrološkog modela EBA4SUB (Event-Based Approach for Small Ungauged Basins) namijenjenog za definiranje hidrograma otjecanja na neizuč...
Xing, Zhuqing; Geng, Weitao; Li, Chao; Sun, Ye; Wang, Yanping
2017-10-09
It is important for probiotics that are currently utilized in the dairy industry to have clear genetic backgrounds. In this study, the genetic characteristics of Lactobacillus kefiranofaciens ZW3 were studied by undertaking a comparative genomics study, and key genes for adaptation to different environments were investigated and validated in vitro. Evidence for horizontal gene transfer resulting in strong self-defense mechanisms was detected in the ZW3 genome. We identified a series of genes relevant for dairy environments and the intestinal tract, particularly for extracellular polysaccharide (EPS) production. Reverse transcription-qPCR (RT-qPCR) revealed significant increases in the relative expression of pgm, ugp, and uge during the mid-logarithmic phase, whereas the expression of pgi was higher at the beginning of the stationary phase. The enzymes encoded by these four genes concertedly regulated carbon flux, which in turn modulated the production of EPS precursors. Moreover, ZW3 tolerated pH 3.5 and 3% bile salt and retained cell surface hydrophobicity and auto-aggregation. In conclusion, we explored the potential of ZW3 for utilization in both the dairy industry and in probiotic applications. Additionally, we elucidated the regulation of the relevant genes involved in EPS production.
Energy Technology Data Exchange (ETDEWEB)
Naito, Masashi; Inouye, Yajiro; Yura, Osamu [Electrotechnical Laboratory, Tokyo (Japan)
1960-06-15
izmerenii aktivnosti bylo vzyato ochen' malen'koe kolichestvo (50 mg) obraztsa na tonkoj plenke. Ono bylo vysusheno v silikagel'nom sushil'nom vakuum-kotle. Zatem obrazets byl vyparen snova. Tonkaya plenka byla poluchena v rezul'tate togo, chto sinteticheskaya smola, pokryvavshaya vodnuyu poverkhnost', byla perenesena na metallicheskoe kol'tso i zatem pokryta ochen' tonkim sloem zolota s pomoshch'yu vyparivaniya v vakuume. Izotopy Sr{sup 90} - Y{sup 90}, So{sup 60} i Cs{sup 137} byli izmereny vysheupomyanuty m sposobom. Tochnost' izmerenij sostavlyala {+-} 2%. 2) Metod 2 ya a({pi}) ({alpha})-scheta. Obraztsy RaD + E + F, U{sup 238} i Ro{sup 210} byli izmereny s pomoshch'yu tekh zhe apparatov, kotorye primenyalis' pri metode 4 ({pi}) ({beta})-scheta. Tochnost' izmereniya sostavlyala {+-}2, {+-} 1 i + 1% sootvetstvenno. 3) Vychislenie metodom, osnovannom na printsipe sovpadenij. Pri pri- menenii ehtogo metoda byli ispol'zovany metody ({beta})-({gamma}) i ({gamma})-({gamma}) scheta. Stsintillyatsionny j schetchik [Nal (TI), 1'' ({Phi}) X 1''] byl ispol'zovan v ka- chestve detektora u-luchej, a schetchik Gejgera-Myuller a - kak detektor ({beta})-uchej. Nedavno dlya togo chtoby issledovat' sushchestvuyushchee razlichie mezhdu vychisleniem metodom 4({pi}) ({beta}) -scheta i metodom, osnovannom na printsipe sovpadenij, my vmesto schetchika Gejgera-Myuller a skonstruiroval i spe- tsial'nyj tip proportsional'nog o 4 ({pi}) ({beta}) -schetchika, kotoryj mozhet, krome togo, byt' ispol'zovan v kachestve proportsional'nog o 4 ({pi}) ({beta})-schetchika nezavisimo ot skhem sovpadenij. Rezul'taty, poluchennye metodom, osnovannym na printsipe sovpadenij, dlya ({beta})-({gamma}) -u izluchenij v obshchem neskol'ko otlichalis' (na 3-4%) ot rezul'tatov metoda vychisleniya 4 ({pi}) ({beta})-scheta. EHto mozhet proizojti blagodarya samopogloshcheniyu . S drugoj storony, rezul'tat dlya So{sup 60}, poluchennyj za schet metoda, osnovannogo na printsipe sovpadenij dlya ({gamma})-({gamma}) izluchenij
Energy Technology Data Exchange (ETDEWEB)
Jacimovic, Lj.; Stevovic, J.; Veljkovic, S. R. [Boris Kidric Institute of Nuclear Sciences, Belgrade, Yugoslavia (Serbia)
1965-04-15
cinetica del recocido. (author) [Russian] Sistema joda-131 v TeO{sub 2} predstavljaet interes, potomu chto malo izvestno o termohimicheskih izmenenijah v jetoj misheni. Radioaktivnyj jod poluchalsja pri nejtronnom obluchenii TeO{sub 2} v reaktore. Obluchennyj TeO{sub 2} rastvorjalsja v razbavlennom rastvore NaOH. Analiz razlichnyh valentnyh form joda proizvodilsja ionoobmennym metodom. Izuchalis' termicheskaja i radiacionnaja ustojchivost' TeO{sub 2} putem ispol'zovanija spektrofotometricheskogo metoda dlja opredelenija tellura i otzhig joda-131 v TeO{sub 2} posle obluchenija v zavisimosti ot vremeni i temperatury nagreva. Glavnaja tendencija otzhiga sostojala v vosstanovlenii radioaktivnogo joda. Zavisimost' jetogo processa ot vremeni ukazyvaet na bystroe izmenenie pri vysokoj temperature. Pri bolee nizkih temperaturah krivye javljajutsja bolee slozhnymi. Otzhig verojatno javljaetsja slozhnym vvidu mnogoobrazija teplovyh reakcij, vkljuchajushhih promezhutochnye soedinenija joda. On mozhet vstupat' v reakciju s produktami processa otdachi jader tellura v sootvetstvujushhej gorjachej zone, beta-perehoda Te{sup 131} i s samoj dvuokis'ju tellura. Rassmatrivalas' kinetika jetih izmenenij i proizvodilas' ocenka processov vo vremja otzhiga. Izuchalos' takzhe vlijanie nejtronnogo potoka na kinetiku otzhiga. (author)
Band structure studies of actinide systems
International Nuclear Information System (INIS)
Koelling, D.D.
1976-01-01
The nature of the f-orbitals in an actinide system plays a crucial role in determining the electronic properties. It has long been realized that when the actinide separation is small enough for the f-orbitals to interact directly, the system will exhibit itinerant electron properties: an absence of local moment due to the f-orbitals and sometimes even superconductivity. However, a number of systems with the larger actinide separation that should imply local moment behavior also exhibit intinerant properties. Such systems (URh 3 , UIr 3 , UGe 3 , UC) were examined to learn something about the other f-interactions. A preliminary observation made is that there is apparently a very large and ansiotropic mass enhancement in these systems. There is very good reason to believe that this is not solely due to large electron--electron correlations but to a large electron--phonon interaction as well. These features of the ''non-magnetic'', large actinide separation systems are discussed in light of our results to date. Finally, the results of some recent molecular calculations on actinide hexafluorides are used to illustrate the shielding effects on the intra-atomic Coulomb term U/sub f-f/ which would appear in any attempt to study the formation of local moments. As one becomes interested in materials for which a band structure is no longer an adequate model, this screened U/sub ff/ is the significant parameter and efforts must be made to evaluate it in solid state systems
Energy Technology Data Exchange (ETDEWEB)
Leveque, P. [Centre d' Etudes Nucleaires de Saclay (France)
1966-11-15
In May 1963, at the Conference held by the International Atomic Energy Agency on the Industrial Uses of Large Radiation Sources, there was considerable discussion of costs. This general exchange of views led to a number of assessments of the cost of treatment by radioactive sources and machines. After three years it seems appropriate to review the basic hypotheses, and in particular to take account of the drop in price: of radioisotopes, especially {sup 137}Cs. This affects the cost both of the installed kW and of the KWh of energy produced. In the light of the experience gained in the past: three years it is possible to define the efficiencies and the load factors observed in plants at present in operation. It is true that in most cases these are treating medical equipment and supplies, but the problems are comparable. (author) [French] En mai 1963, lors de la Conference organisee par l'AIEA sur l'emploi des sources de rayonnements intenses dans l'industrie, un large debat s'etait engage sur les prix de revient. De cette confrontation generale, on a pu tirer quelques evaluations du cout de traitement par sources radioactives et machines. Il est bon, trois ans apres, de revoir les hypotheses de base et surtout de tenir compte de l'abaissement du prix des radioelements et tout specialement du {sup 137}Cs. Ceci influe a la fois sur le prix du kW installe et du kWh d'energie produit. A la lumiere de l'experience acquise pendant ces trois dernieres annees, il est possible de preciser les rendements et facteurs de charge observes dans des installations actuellement en fonctionnement. Il s'agit il est vrai, dans la majorite des cas, de traitements d'accessoires medicaux, mais les problemes sont comparables. (author) [Spanish] En la Conferencia sobre las aplicaciones industriales de las fuentes de radiacion de elevada intensidad, celebrada.en mayo de 1963 bajo los auspicios del OIEA, se inicio un amplio debate sobre los precios de costo. De esta confrontacion general se pudieron sacar varias conclusiones sobre el costo del tratamiento por medio de fuentes radiactivas y maquinas. Es conveniente, tres aflos despues, revisar las hipotesis fundamentales y, sobre todo, tener en cuenta el abaratamiento de los radioelementos, en particular, del {sup 137}Cs. Esto influye a la vez sobre el precio del kilovatio instalado y del kilovatio-hora de energfa producido. La experiencia adquirida en estos tres ultimos aflos permite precisar los rendimientos y factores de carga observados en instalaciones actualmente en servicio. Es cierto que en la mayorfa de los casos estas consisten en instalaciones de tratamiento de accesorios medicos, pero los problemas son analogos. (author) [Russian] V mae 1963 goda vo vremja raboty Konferencii po promyshlennomu primeneniju moshhnyh istochnikov izluchenija, organizovannoj MAGATJe, razvernulas' bol'shaja diskussija po voprosu sebestoimosti. V rezul'tate obmena mnenijami mozhno sdelat' nekotorye ocenki stoimosti obrabotki radioaktivnymi istochnikami i ustrojstvami. Zhelatel'no po istechenii treh let peresmotret' osnovnye gipotezy i uchest' snizhenie stoimosti radiojelementov, i v osobennosti cezija-137. Stoimost' radiojelementov okazyvaet vlijanie srazu na stoimost' 1 kvt ustanovlennoj moshhnosti i kilovatt/chasa proizvodimoj jelektrojenergii. V svete poluchennogo v techenie poslednih treh let opyta imeetsja vozmozhnost' utochnit' proizvoditel'nost' i kojefficient nagruzki dejstvujushhih v nastojashhee vremja ustanovok; Rech' idet v bol'shinstve sluchaev ob obrabotke vspomogatel'nogo medicinskogo oborudovanija, no vse jeti problemy sravnimy. (author)
Energy Technology Data Exchange (ETDEWEB)
Lund, S. A. [Danish Central Welding Institution, Copenhagen (Denmark); Knudsen, P. [Danish Atomic Energy Commission, Research Establishment, Risoe (Denmark)
1965-09-15
The Danish Atomic Energy Commission has undertaken a design study oi an organic-cooled, heavy- water-moderated power reactor. The fuel element for the reactor is a 19-rod bundle; the fuel rods contain sintered uranium-dioxide pellets canned in 2-m long, helically-finned tubes of Sintered Aluminium Product (SAP). A very high quality of the canning tubes is necessary to obtain the optimum heat-transfer conditions and to maintain the integrity of the fuel element during reactor service. Two examples of tube design illustrate the narrow dimensional tolerances. In order to ensure an adequate quality of the canning tubes, a stringent quality control has been established, to a wide extent based upon non-destructive methods. An account is presented of the non-destructive techniques developed for measuring wall thickness and diameters and for detecting defects. The complex 24-finned cross-section prevents the application of ultrasonic or eddy-current methods for wall-thickness measurements. Therefore, a special recording beta-gauge has been developed, based upon the attenuation of beta radiation from a Sr{sup 90} source placed inside the tube. An ultrasonic immersion resonance method is used for the continuous recording of the wall thickness of the more simple 12-finned tube design. Inner and outer (across fin tips) diameters are continuously recorded by rapid air-gauge systems. Flaw detection is carried out by the ultrasonic pulse-echo immersion technique and by eddy-current inspection.. Transverse cracks can easily be detected by the ultrasonic method whereas inspection for longitudinal flaws has not appeared feasible with this method. Therefore, eddy-current inspection is applied in addition to the ultrasonic testing. (author) [French] La Commission de l'energie atomique danoise a entrepris l'etude d'un reacteur de puissance refroidi par un fluide organique et ralenti a l'eau lourde. L'element combustible est constitue par un assemblage de 19 barreaux; chaque barreau
Directory of Open Access Journals (Sweden)
Mihailo R. Mrdak
2016-04-01
. Radi dobijanja strukturnih i mehaničkih osobina slojeva, koji će obezbediti dobru toplotnu i abrazivnu zaštitu zadnjim krilima aviona J-22 pri ispaljivanju raketa munje i groma, izvršena je depozicija tri tipa praha na substratima od legure Al debljine 0,6 mm. Ova studija opisuje postupak korišćenja troslojne TBC prevlake kao izbor dobre kombinacije od mnogo raspoloživih mogućnosti, koja predstavlja kompromis između toplotne zaštite i otpornosti na abraziju za zaštitu zadnjih krila aviona. Studija se, uglavnom, zasniva na eksperimentalnom pristupu. Procena mehaničkih osobina slojeva urađena je ispitivanjem mikrotvrdoće metodom HV0.3 i čvrstoće spoja ispitivanjem na zatezanje. Struktura slojeva ispitana je metodom svetlosne mikroskopije i površina ZrO2MgO keramičkih slojeva metodom skenirajuće elektronske mikroskopije (SEM. Toplotna zaštita TBC slojeva i otpornost na abraziju ispitana je u tunelu Vojnotehničkog instituta iz Žarkova. Na osnovu dobijenih karakteristika površinskih slojeva i simuliranja ispaljivanja rakete, troslojni sistem TBC prevlake pokazao se pouzdanim.
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Venkat Rao Pulla
2014-02-01
Full Text Available This paper is about the Tibetan people in two settlements, mainly in Nepal and India. Tibetan ref- ugees started crossing the Himalayan range in April 1959, in the wake of the Dalai Lama’s flight into exile and landed mostly in Nepal and India. Tibetans around the world do not know their fu- ture nor do they appear unduly worried. Most of them appear resilient and hopeful to see a ‘free Tibet’ a dream closer to their hearts, someday in the future. In this paper, we delve at their deep association between their philosophy of life based on the principles of ‘karma’ and their everyday economic avocation of weaving ‘carpets’. We find that these people weave their lives around kar- ma and the carpets. Karma embodies their philosophical and spiritual outlook while carpets, mats and paintings symbolise their day-to-day struggles, enterprises to cope, survive, thrive and flour- ish. The ‘karma carpet’ symbolises their journey into the future. The Tibetans although a refugee group do not have the same rights and privileges comparable to other refugees living in the world decreed under the United Nations Conventions. In this paper, we present the socio-economic situ- ation of these refugees, their enterprise and their work ethic that makes them who they are in the Nepalese and in Indian societies. For this research, we have triangulated both desk studies and personal narratives from focus groups and interviews to present a discussion centred on the Ti- betan struggle for human rights and their entrepreneurship through the carpet industry mainly in Nepal and India.
Energy Technology Data Exchange (ETDEWEB)
Horber, E. [Swiss Experimental Station for Agriculture, Zurich-Oerlikon (Switzerland)
1963-09-15
observe une certaine diminution des larves en b) et c), due a la secheresse qui regnait dans toute la region. Il a ete demontre que la methode du lacher de males steriles peut etre appliquee avec succes dans la lutte contre un insecte nuisible qui se trouve dans une region qui n'est pas strictement isolee du point de vue geographique, dont les femelles s'apparient plusieurs fois et dont l'elevage en masse est impossible en raison de la duree du cycle evolutif. (author) [Spanish] Ensayos realizados en laboratorio indicaron que para esterilizar a los abejorros machos basta con una dosis de rayos X de 3000 roentgens. Durante dos periodos de vuelo se soltaron machos esterilizados en una region agricola del noroeste de Suiza con objeto de erradicar las larvas. En 1950 esta plaga habia sido combatida con procedimientos quimicos. Entre 1953 y 1962 se observo la actividad en todos los vueles. En 1959 se seleccionaron cinco zonas de 30 hectareas cada una que sirvieron de: a) Zona de tratamiento, en la que se capturaron, irradiaron y soltaron machos; b) Zona de reserva, en la que se recogieron abejorros y se irradiaron machos que se soltaron en a); c) Zonas de control, en las que se observo la actividad normal. Los machos fueron irradiados con un aparato terapeutico de rayos X. Despues de la irradiacion se les puso una marca de color para poder calcular su porcentaje mediante la tecnica de dilucion isotopica. En 1959, durante el primer tratamiento, se soltaron en la zona a unos 6 l de machos esterilizados, lo que representaba aproximadamente el 50% del total de machos de dicha zona. La cantidad de larvas recogidas en los prados despues del tratamiento represento unos 2/3 de la correspondiente a las zonas de control. La razon de reproduccion solo fue inferior a la unidad en la zona a). Cuando se calculo, en 1962, el numero de abejorros supervivientes se observo que en la zona a habia disminuido hasta 1/10 en comparacion con las zonas b) y c). De 1959 a 1962 la cifra mas elevada de
Directory of Open Access Journals (Sweden)
Sergio Marrone Ribeiro
2004-12-01
Full Text Available OBJETIVO: Tentar estabelecer uma metodologia no diagnóstico e conduta dos pacientes com massas renais sólidas e complexas, comparando os custos e benefícios dos diferentes métodos de diagnóstico por imagem. Procuramos avançar no diagnóstico diferencial entre lesões benignas e malignas, particularmente através da investigação das calcificações tumorais. MÉTODOS: Realizamos um estudo prospectivo em 31 pacientes portadores de massas renais sólidas ou complexas, todos eles submetidos à ultra-sonografia abdominal (US, ultra-sonografia doppler da massa renal (US Dop, tomografia computadorizada (TC e ressonância magnética (RM. RESULTADOS: Encontramos 28 pacientes com massas malignas e três com massas benignas. Entre os 28 pacientes com lesões malignas, 17 mostraram calcificações pela TC; 16 deles calcificações do tipo central e um calcificação do tipo curvilinear periférica pura (casca de ovo. A urografia excretora (UGE mostrou uma taxa de detecção para calcificações significantemente menor que a US e a TC. Massas benignas e malignas apareceram como descrito na literatura, com o US, TC e RM mostrando alta sensibilidade e especificidade no diagnóstico dos tumores renais. A exceção foi na US Dop, onde nós obtivemos menor sensibilidade para a caracterização de fluxo tumoral maligno. CONCLUSÕES: Foi surpreendente verificar que a TC revelou calcificações centrais em 51,6% dos pacientes desta série, todas elas em lesões malignas, quando a literatura refere uma freqüência de calcificações entre 8% e 22% dos carcinomas de células renais, em estudos utilizando radiografias simples do abdômen e UGE. Este achado é de grande importância quando consideramos que estas calcificações ocorrem particularmente em neoplasias malignas. Como resultado da comparação dos diferentes métodos de diagnóstico por imagem, nós propomos uma metodologia para adequada investigação dos tumores renais.BACKGROUND: To establish the
Curious Cases of the Enzymes / Neobiča Istorija Enzima
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Ulusu Nuriye Nuray
2015-07-01
Full Text Available : Život oko nas uglavnom se zasniva na biološkoj katalizi, pa bi se čak, u nekakvoj neromantičnoj priči, život mogao opisati kao niz hemijskih reakcija koje regulišu glavni principi termodinamike. U davnoj prošlosti, kucanje srca bilo je znak dobrog zdravlja, međutim, za mene, najvažniju ulogu ima upravo prisustvo enzima... Mada ne obraćamo često pažnju na to, istorija enzimologije stara je koliko i sam ljudski rod i seže daleko u prošlost. CVaj rad posvećen je baš tim počecima u ovoj veoma zanimljivoj nauci, koja je u prošlosti ostavila traga na našim životima i koja će u budućnosti učiniti da život bude mnogo produktivniji za čovečanstvo. Između čoveka i enzima postojao je oduvek jedan delikatan, suštinski važan odnos. Suočen s nepoznatom i neprijateljski nastrojenom prirodom punom grabljivaca, preistorijski čovek rano je otkrio lekovita svojstva biljaka, i to metodom probe i greške. Štaviše, slučajno su otkriveni inhibitori enzima, čime je, grubo rečeno, još tada otvorena nova oblast istraživanja. Oi biljni derivati koji su imali ulogu inhibitora enzima pomagali su preistorijskom čoveku u njegovoj borbi da opstane i zaštiti se od grabljivaca; prilikom lova i ribolova... Kasnije kroz istoriju, sa nepro- menjenom svrhom opstanka i poboljšanja kvaliteta života, enzimologija je iz korena transformisana, a metodologiju »probe i greške« iz praistorije zamenile su racionalne naučne teorije.
Energy Technology Data Exchange (ETDEWEB)
Kocic, A [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)
1977-07-01
General sampling Monte Carlo scheme for neutron transport equation has been described. Programme TRANSFER for neutron beam transmission analysis has been used to calculate the neutron leakage spectrum, detector efficiency and neutron angular distribution of the example problem (author) [Serbo-Croat] U radu se najpre razmatraju osnovni problemi resavanja transportne jednacine i nacin kako Monte Karlo metoda omogucuje da se prevazidju neki od njih: visedimenzionalnost zadatka, problem dubokog prodiranja i dovoljno fino tretiranje efikasnih preseka. Dalje, govori se o iskustvima sa primenom Monte Karlo metode u Laboratoriji za nuklearnu energetiku i tehnicku fiziku i o primeni ove metode na probleme zastite. Na kraju dati su i analizirani ilustrativni primeri proracuna transporta neutrona kroz ravan sloj zastitnog materijala koriscenjem Monte Karlo programa TRANSFER (author)
Energy Technology Data Exchange (ETDEWEB)
Zakir' yanova, I D; Salyulev, A B [UrO RAN, Inst. Vysokotemperaturnoj Ehlektrokhimii, Ekaterinburg (Russian Federation)
2007-09-15
Systematic structural studies of crystalline (over a wide temperature range) and molten LaCl{sub 3}, CeCl{sub 3}, and NdCl{sub 3} salts (near the crystal-melt phase transition temperature) are conducted employing Raman spectroscopy. A change in the trend of temperature dependences of characteristic frequencies is revealed in the pre-melting region of the compounds. This is attributed to an increase in the number of crystal defects due to weakening of a part of Ln-Cl bonds and decreasing of coordination number of chloride anions in the vicinity of rare earth cation.
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Julie Hougaard Overgaard
2016-11-01
Full Text Available Dansk Vi beskriver, hvordan virtuelle eksperimenter kan udnyttes i et læringsdesign ved at forberede de studerende til hands-on-eksperimenter ved storskalafaciliteter. Vi illustrerer designet ved at vise, hvordan virtuelle eksperimenter bruges på Niels Bohr Institutets kandidatkursus om neutronspredning. I den sidste uge af kurset, rejser studerende til et storskala neutronspredningsfacilitet for at udføre neutronspredningseksperimenter. Vi bruger studerendes udsagn om deres oplevelser til at argumentere for, at arbejdet med virtuelle experimenter forbereder de studerende til at engagere sig mere frugtbart med eksperimenter ved at lade dem fokusere på fysikken og relevante data i stedet for instrumenternes funktion. Vi hævder, at det er, fordi de kan overføre deres erfaringer med virtuelle eksperimenter til rigtige eksperimenter. Vi finder dog, at læring stadig er situeret i den forstand, at kun kendskab til bestemte eksperimenter overføres. Vi afslutter med at diskutere de muligheder, som virtuelle eksperimenter giver. English We describe how virtual experiments can be utilized in a learning design that prepares students for hands-on experiments at large-scale facilities. We illustrate the design by showing how virtual experiments are used at the Niels Bohr Institute in a master level course on neutron scattering. In the last week of the course, students travel to a large-scale neutron scattering facility to perform real neutron scattering experiments. Through student interviews and survey answers, we argue, that the virtual training prepares the students to engage more fruitfully with experiments by letting them focus on physics and data rather than the overwhelming instrumentation. We argue that this is because they can transfer their virtual experimental experience to the real-life situation. However, we also find that learning is still situated in the sense that only knowledge of particular experiments is transferred. We proceed to
Energy Technology Data Exchange (ETDEWEB)
Kevorkyan, Yu R
1974-01-01
A SPIKE program is used to study regions of structural damage that arise as a result of cascades of atomic collisions in single-crystal alpha iron. The model of the cascade process realized in the program uses a pair collision approximation and accounts for the influence of the crystal structure of the material. The following characteristics of regions of damage are found as a function of the energy of the primary knock-on atom: volume of the region, displacement effectiveness, size distribution of complexes of vacancies and injections. The results are compared with data in the literature. An appendix gives the text of the SPIKE program in FORTRAN.
Systems of Rb2I2-CdI2-PbI2 and Cs2I2-CdI2-PbI2
International Nuclear Information System (INIS)
Volchanskaya, V.V.; Il'yasov, I.I.
1979-01-01
The Rb 2 I 2 -CdI 2 -PbI 2 and Cs 2 I 2 -CdI 2 -PbI 2 triple systems have been studied, using the visual-polythermal method. The liquidus of the systems researched consists of the components and compounds crystallization fields: 2RbIxCdI 2 , 2RbIxRbI 2 , RbIxPbI 2 and 2CsIxCdI 2 , 4CsIxPbI 2 , CsIxPbI 2 , respectively. The crystallization fields converge in four non-variant points at 360, 280, 205 and 192 deg C in the Rb 2 I 2 -CdI 2 -PbI 2 system and at 375, 368, 208 and 190 deg C in the CsI 2 -CdI 2 -PbI 2 system
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Mihailo R. Mrdak
2018-01-01
kompozitnoj keramici Ca10(PO46(OH2-Al2O3-ZrO2-Cr2O3 i drugim bioinertnim keramikama, praveći kompozi tipa Al2O3-ZrO2-SrO-Cr2O3-Y2O3, ZrO2-TiO2-Cr2O3 i TiO2-Cr2O3 za povećanje mehaničkih karakteristika i otpornosti komponenti veštačkog zgloba na habanje klizanjem i koroziju. U radu je analiziran uticaj odstojanja plazma pištolja od podloge na mehaničke karakteristike i mikrostrukturu Cr2O3 slojeva deponovanih sa snagom napajanja od 40 kW. Cilj rada bio je da se deponuju slojevi optimalnih karakteristika koji će omogućiti efikasnu primenu Cr2O3 slojeva na podlogama čeličnih implantata izloženih suvom trenju bez podmazivanja i koroziji živih tkiva. Ispitivanje mehaničkih karakteristika realizovano je ispitivanjem mikrotvrdoće slojeva metodom HV0.3 i čvrstoće spoja metodom na zatezanje. Izgled površine čestica praha ispitan je metodom SEM. Mikrostrukture slojeva analizirane su uz primenu optičkog mikroskopa (OM i skening elektronskog mikroskopa (SEM. Rezultati ispitivanja potvrdili su mogućnost efikasne primene bioinertnih slojeva Cr2O3 sa drugim keramikama namenjenim za izradu funkcionalnih implantata.
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Mihailo R. Mrdak
2015-04-01
Full Text Available U radu je analizirana vakuum plazma sprej prevlaka VPS – Cr3C2 - 25(Ni20Cr. Upotrebljen je komercijalni prah oznake Sulzer Metco Woka 7205. Prah je deponovan sa plazma pištoljem F4 na odstojanju substrata od 340 mm. Glavni cilj rada bio je da se na smanjenom pritisku inertnog gasa Ar eliminiše razgradnja primarnog karbida Cr3C2 u karbid Cr23C6 koji bitno umanjuje mikrotvrdoću i mehaničke karakteristike prevlake. Prevlaka je deponovana debljine od 100 do 120 µm na čeličnom substratu. Mikrotvrdoća prevlake ispitana je metodom HV0.3. Vrednosti mikrotvrdoće bile su u rasponu od 1248 do 1342 HV0.3. Čvrstoća spoja prevlake ispitana je metodom na zatezanje. Utvrđeno je da čvrstoća spoja između substrata i prevlake ima vrednost 89 MPa. Mikrostruktura prevlake ispitana je tehnikom svetlosne mikroskopije. Struktura prevlake sastoji se od osnove NiCr legure sa dominantnom primarnom karbidnom fazom Cr3C2. Pored Cr3C2 faze prisutna je i faza Cr7C3. Nagrizanje prevlake urađeno je reagensom 1HNO3: 4HCl: 4H2O koji prvenstveno rastvara Ni da bi se videla raspodela karbidne faze u prevlaci. Nagrizanjem prevlake reagensom utvrđeno je da je u slojevima prevlake u velikom udelu prisutna primarna nerazgrađena karbidna faza Cr3C2 koja prevlaci daje visoke vrednosti mikrotvrdoće. / This paper analyzes vacuum plasma spray VPS - Cr3C2 - 25(Ni20Cr coatings. Commercial powder marked Sulzer Metco Woka 7205 is used. The powder is deposited with a plasma gun F4 at a distance of 340 mm from the substrate. The main objective of the study was to eliminate, at the reduced pressure of inert gas Ar, the degradation of primary Cr3C2 carbide into Cr23C6 carbide which significantly reduces the microhardness and mechanical properties of the coating. The coating is deposited with a thickness of 100 - 120 µm on a steel substrate. The microhardness of the coating was tested by HV0.3. The microhardness values were in the range of 1248 - 1342 HV0.3. The bond strength
Energy Technology Data Exchange (ETDEWEB)
Carr, T. E.F.; Parsons, B. J. [Medical Research Council, Radiobiological Research Unit, Harwell (United Kingdom)
1965-10-15
A review is made of some of the methods for the assay of {sup 45}Ca in biological materials. Experience gained from the assay of {sup 45}Ca in such materials, using a liquid scintillation technique previously published by the authors, is reported. Difficulties were found with certain samples because of the presence of relatively large amounts of iron. The quenching of the scintillator due to this iron, and methods for overcoming it are discussed. Results are given of the use of external gamma-ray sources as standards and as a means of estimating quenching effects in certain samples. Though not entirely satisfactory for the measurement of quenching, their use as a standard for checking counter performance is recommended. A comparison is given of the methods, including liquid and plastic scintillation counting of {sup 45}Ca covering the following aspects: (a) efficiency, (b) background, (c) ease and speed of sample preparation, (d) use of standards and reproducibility, and (e) stable calcium capacity. Recommendations are made as to which technique is most suitable under given circumstances. (author) [French] Les auteurs examinent plusieurs methodes de dosage de {sup 45}Ca contenu dans des substances biologiques. Ils decrivent les resultats qu'ils ont obtenus precedemment en analysant, au' moyen d'un scintillateur liquide, le {sup 45}Ca contenu dans ces substances. Certains echantillons ont cause des difficultes, car ils contenaient des quantites de fer assez importantes. Le memoire fait etat de l'extinction du scintillateur provoquee par ces quantites de fer et discute les methodes qui permettent d'y remedier. Les auteurs donnent les resultats obtenus avec des sources gamma exterieures utilisees comme etalons qui permettent par ailleurs d'evaluer les effets d'extinction dans certains echantillons. Bien que ces sources ne soient pas entierement satisfaisantes pour mesurer l'extinction, ils recommandent de les utiliser comme etalons pour controler la performance du compteur. Les auteurs comparent les diverses methodes de comptage de {sup 45}Ca notamment avec scintillateurs liquides ou en matiere plastique, sous les aspects suivants: a) efficacite, b) bruit de fond, c) facilite et vitesse de preparation des echantillons, d) emploi d'etalons et reproductibilite, et e) capacite en calcium stable. Les auteurs formulent des recommandations touchant la technique qu'ils considerent comme la plus appropriee dans des conditions donnees. (author) [Spanish] Los autores pasan revista a algunos metodos de determinacion del calcio-45 en sustancias biologicas. Se describe la experiencia adquirida en la determinacion de calcio-45 en dichas sustancias aplicando una tecnica de recuento con centelleador laquido ya dada a conocer por los autores. Ciertas muestras suscitaron dificultades debidas a la presencia de cantidades relativamente grandes de hierro. Se estudia la extincion provocada por este ultimo elemento, asf como metodos para superar esta dificultad. Se exponen los resultados del empleo de fuentes gamma internas como patrones y como medio de evaluar los efectos de extincion en ciertas muestras. Aunque no son enteramente satisfactorias para medir la extincion, se recomienda su uso como patrones para comprobar el correcto funcionamiento del contador. Se comparan los resultados de esos metodos, incluidos los de determinacion del {sup 45}Ca por recuento con centelleador liquido y plastico, con respecto a los siguientes puntos: a) rendimiento, b) actividad de fondo, c) facilidad y rapidez de preparacion de muestras, d) empleo de patrones y reproductibilidad, y e) influencia del calcio estable. Se formulan recomendaciones sobre la tecnica mas apropiada segun las circunstancias de cada caso. (author) [Russian] Daetsja obzor nekotoryh metodov ocenki kal'cija-45 v biologicheskih materialah. Soobshhaetsja ob opyte, nakoplennom v processe ocenki kal'cija-45, s primeneniem metoda scheta zhidkostnym scintilljatorom, o kotorom avtory soobshhali ranee. Pri ocenke nekotoryh obrazcov voznikali trudnosti vvidu prisutstvija sravnitel'no bol'shih kolichestv zheleza. Obsuzhdajutsja problemy oslablenija scintilljatora vvidu prisutstvija zheleza i metody preodolenija takogo oslablenija. Privodjatsja rezul'taty ispol'zovanija vneshnih istochnikov gamma-izluchenija v kachestve standartov i sredstv ocenki jeffektov oslablenija v nekotoryh obrazcah. Rekomenduetsja primenjat' ih v kachestve standartov dlja proverki harakteristiki schetchika, hotja oni ne polnost'ju udovletvorjajut trebovanijam pri izmerenii stepeni oslablenija. Provoditsja sravnenie metodov, v tom chisle metodov scheta kal'cija-45 zhidkim i plasticheskim scintilljatorami, s ohvatom sledujushhih aspektov: a) jeffektivnost'; b) fon; v) legkost' i skorost' podgotovki obrazcov; g) primenenie standartov i vosproizvodimost'; d) emkost' ustojchivogo kal'cija. Dajutsja rekomendacii otnositel'no stepeni prigodnosti jetih metodov pri zadannyh obstojatel'stvah. (author)
Arc in a Gas Flowing Through a Magnetic Field; Duga v potoke gaza pri nalichii magnitnogo polya
Energy Technology Data Exchange (ETDEWEB)
Baranov, V. Ju.; Vasil' eva, I. A.; Ul' janov, K. N. [Vsesojuznyj Jelektrotehnicheskij Institut Im.V.I. Lenina, Moskva, SSSR (Russian Federation)
1966-10-15
' provodit' issledovanija v spektral'no chistom argone. Davlenie menjalos' v diapazone 1-M00mm.rt.st., skorosti potoka V{sub 0} Less-Than-Or-Equal-To 10{sup 4} sm/sek. Magnitnoe pole v usko - ritele (B{sub 1}) i oblasti issleduemoj dugi (B{sub 2}) menjalis' ot 0 do 7*10{sup 3} je. Provodilis' zondovye i spektral'n{sub e} izmerenija raspredelenij v prostranstve koncentracii jelektronov pe i temperatury jelektronov T{sub e}. Temperatura gaza T{sub g} izmerjalas' metodom nakalivaemoj niti, skorost' potoka - pri pomoshhi trubok Pito. Jeksperimenty provodilis' kak v tormozjashhem, tak i v uskorjajushhem magnitnom pole. (author)
Energy Technology Data Exchange (ETDEWEB)
Sodee, D. B. [Doctors Hospital and Renner Clinic Foundation, Cleveland Heights, OH (United States)
1964-10-15
casos. El carcinoma mas pequeno que no pudo visualizarse estaba ocultado por el higado hipertrofiado. La exploracion pancreatica permite tambien confirmar la pancreatitis aguda y cronica, ya que las celulas lesionadas no concentran la selenometionina-{sup 75}Se. El autor trata ademas de la concentracion selectiva de la selenometionina{sup 75}Se en el tejido paratiroideo. Con la misma tecnica de expioracion se han visualizado adenomas paratiroideos en un pequeno grupo de enfermos de hiperparatiroidismo. La fotoexploracion del pancreas es ya una tecnica de uso corriente; actualmente se estudia la posibilidad de una fotoexploracion de la paratiroides. Debido a la mayor importancia medica atribuida a organos que antes no podian visualizarse con las tecnicas radiograficas tradicionales, la exploracion selectiva de organos por medio de compuestos marcados, elegidos segun sus propiedades bioquimicas, va adquiriendo cada vez mayor importancia. (author) [Russian] Nedavno bylo pokazano, chto fotoskennirovanie podzheludochnoj zhelezy s pomoshh'ju selenometionina, mechennogo {sup 75}Se , javljaetsja prakticheskim metodom. U 90%iz 100 bol'nyh, u kotoryh bylo polucheno 250 podobnyh fotoskennogramm, mozhno bylo otchetlivo videt' podzheludochnuju zhelezu. Bylo obnaruzheno, chto fiziologicheskaja stimuljacija podzheludochnoj zhelezy javljaetsja glavnym faktorom koncentracii selenometionina -Se15 v podzheludochnoj zheleze. Za chas do vnutrivennogo vvedenija v organizm 3-4 mkk/kg selenometionina-Ze75 s pomoshh'ju 30 grammov belkovoj pishhi byla nachata fiziologicheskaja stimuljacija podzheludochnoj zhelezy. Cherez 15 minut byla dostignuta nepreryvnaja stimuljacija podzheludochnoj zhelezy putem vvedenija cherez rot 900 mkg gidrohlorida glutaminovoj kisloty. Do skennirovanija podzheludochnoj zhelezy nad oblast'ju pecheni, predvaritel'no opredelennoj pri skennirovanii s pomoshh'ju zolota-198, byl pomeshhen izognutyj zashhitnyj jekran iz svinca razmerom 0,9 sm, Jetot jekran blokiruet
Energy Technology Data Exchange (ETDEWEB)
Auriol, A.; David, C. [Battelle Memorial Institute, Geneve (Switzerland); Fillatre, A.; Kurka, G.; Le Boulbin, E.; Rappeneau, J. [Commissariat a l' Energie Atomique (France)
1963-11-15
osadka. Ehtot sposob pokrytiya byl perenesen na zerna okisi i karbida urana metodom dvizhushchegosya sloya. Posle utochneniya uslovij pokrytiya ehtikh zeren byla issledovana ikh makro- i mikrostruktury, a takte ikh pronitsaemost'. Byli izucheny svojstva ehtikh zeren pri vysokoj temperature na predmet ikh vozmozhnogo primeneniya v reaktore. (author)
Directory of Open Access Journals (Sweden)
Sretko Ilić
2002-01-01
Full Text Available U radu je istraživana mogućnost poboljšanja kvaliteta aktivnog uglja (AU za upotrebu u sredstvima za ličnu zaštitu respiratornih organa od dejstva amonijaka. Uzorci komercijalnih AU oksidovani su različitim količinama rastvora sumporne kiseline, masenih koncentracija 10% i 15%. Na uzorke AU tretirane kiselinom deponovan je zatim bakar-sulfat, metodom dvostruke impregnacije rastvorom bakar-sulfata do početne vlažnosti uzorka. Impregnisani AU ispitanje u sloju u gasnom filtru prečnika 105 mm, čije su visine imale vrednosti od 29 mm do 41 mm, a uslovi su bill: ulazna koncentracija amonijaka -3,5 mg/dm3 (zapreminska koncentracija 0,5%, protok gasne smeše vazduh-amonijak - 30 dm3/min, relativna vlažnost 70% i ambijentna temperatura. Proboj je detektovan kvalitativno, pomoću indikatorskog papirića safenolftaleinom. AU impregnisan novim postupkom obezbedio je u sloju visine 29 mm vreme proboja 108 min, a 160 min u sloju visine 41 mm. / The objective of this paper has been the study of the possibility to enhance the properties of activated carbon (AC for using it in respiratory protective devices for ammonia removal from the air. The commercial AC samples were oxidized with different amounts of 10% and 15% sulphuric acid solutions. The acid treated AC samples were the loaded with copper sulphate with twofold impregnation by the incipient wetness method. The impregnated AC was tested in a packed bed in the gas filter with a diameter of 105 mm and a bed depth ranging from 29 mm to 41 mm under the following test conditions inlet concentration of ammonia was 3,5 mg/dm3, flow rate of 30 dm3/min at 70% relative humidity and ambient temperature. The breakthrough was detected qualitatively by the phenolphtalein indicator paper. The new impregnated AC reached the breaktrough time of 108 min for a 29 mm bed depth, and 160 min for a bed depth of 41 mm.
Investigation of the Na2(H2PO2)2 - Ba(H2PO2)2 - H2O Water-Salt Ternary System at Room Temperature
Erge, Hasan; Turan, Hakan; Kul, Ali Riza
2016-01-01
Objective: In this study, the solubility, density, conductivity and phase equilibria of the Na2(H2PO2)2-Ba(H2PO2)2-H2O ternary system located in the structure of the Na+, Ba2+, (H2PO2)-//H2O quaternary reciprocal water-salt system were investigated using physicochemical analysis methods. Material and Methods: Riedel-de Haen and Merck salts were used to investigate the solubility and phase equilibria of the Na2(H2PO2)2 -Ba(H2PO2)2-H2O ternary water–salt system at room temperature Res...
Bobadova-Parvanova, Petia; Wang, Qingfang; Quinonero-Santiago, David; Morokuma, Keiji; Musaev, Djamaladdin G
2006-09-06
The mechanisms of dinitrogen hydrogenation by two different complexes--[(eta(5)-C(5)Me(4)H)(2)Zr](2)(mu(2),eta(2),eta(2)-N(2)), synthesized by Chirik and co-workers [Nature 2004, 427, 527], and {[P(2)N(2)]Zr}(2)(mu(2),eta(2),eta(2)-N(2)), where P(2)N(2) = PhP(CH(2)SiMe(2)NSiMe(2)CH(2))(2)PPh, synthesized by Fryzuk and co-workers [Science 1997, 275, 1445]--are compared with density functional theory calculations. The former complex is experimentally known to be capable of adding more than one H(2) molecule to the side-on coordinated N(2) molecule, while the latter does not add more than one H(2). We have shown that the observed difference in the reactivity of these dizirconium complexes is caused by the fact that the former ligand environment is more rigid than the latter. As a result, the addition of the first H(2) molecule leads to two different products: a non-H-bridged intermediate for the Chirik-type complex and a H-bridged intermediate for the Fryzuk-type complex. The non-H-bridged intermediate requires a smaller energy barrier for the second H(2) addition than the H-bridged intermediate. We have also examined the effect of different numbers of methyl substituents in [(eta(5)-C(5)Me(n)H(5)(-)(n))(2)Zr](2)(mu(2),eta(2),eta(2)-N(2)) for n = 0, 4, and 5 (n = 5 is hypothetical) and [(eta(5)-C(5)H(2)-1,2,4-Me(3))(eta(5)-C(5)Me(5))(2)Zr](2)(mu(2),eta(2),eta(2)-N(2)) and have shown that all complexes of this type would follow a similar H(2) addition mechanism. We have also performed an extensive analysis on the factors (side-on coordination of N(2) to two Zr centers, availability of the frontier orbitals with appropriate symmetry, and inflexibility of the catalyst ligand environment) that are required for successful hydrogenation of the coordinated dinitrogen.
Energy Technology Data Exchange (ETDEWEB)
Davis, B.
1987-10-01
4-Aminobutanoic acid-2,2-/sup 2/H/sub 2/ and -4,4-/sup 2/H/sub 2/ were synthesized in high yield with high deuterium incorporation, and then converted into the corresponding deuterium-labelled anti-convulsant drug, progabide, by means of a transimination reaction.
International Nuclear Information System (INIS)
Cao, Hong-yu; Zhou, Huan; Bai, Xiao-qin; Ma, Ruo-xin; Tan, Li-na; Wang, Jun-min
2016-01-01
Graphical abstract: Solubility diagram of the (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) system at T = (323.15 and 298.15) K. - Highlights: • Phase diagrams of Ca 2+ -H 2 PO 2 − -Cl − -H 2 O, Ca 2+ -Na + -H 2 PO 2 − -H 2 O at 323.15 K were obtained. • Incompatible double salt of NaCa(H 2 PO 2 ) 3 in Ca 2+ -Na + -H 2 PO 2 − -H 2 O system was determined. • Density diagram of the corresponding liquid were simultaneously measured. - Abstract: Calcium hypophosphite has been widely used as an anti-corrosive agent, flame retardant, fertilizer, assistant for Ni electroless plating, and animal nutritional supplement. High purity calcium hypophosphite can be synthesized via the replacement reaction of sodium hypophosphite and calcium chloride. In this work, the (solid + liquid) phase equilibria of (Ca(H 2 PO 2 ) 2 + CaCl 2 + H 2 O) and (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) ternary systems at T = 323.15 K were studied experimentally via the classical isothermal solubility equilibrium method, and the phase diagrams for these two systems were obtained. It was found that two solid salts of CaCl 2 ·2H 2 O and Ca(H 2 PO 2 ) 2 exist in the (Ca(H 2 PO 2 ) 2 + CaCl 2 + H 2 O) system, and three salts of Ca(H 2 PO 2 ) 2 , NaH 2 PO 2 ·H 2 O and one incompatible double salt, NaCa(H 2 PO 2 ) 3 occur in the (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) system.
Synthesis and structure of [(NH2)2CSSC(NH2)2]2[OsBr6]Br2 . 3H2O
International Nuclear Information System (INIS)
Rudnitskaya, O. V.; Kultyshkina, E. K.; Stash, A. I.; Glukhova, A. A.; Venskovskii, N. U.
2008-01-01
The complex [(NH 2 ) 2 CSSC(NH 2 ) 2 ] 2 [OsBr 6 ]Br 2 . 3H 2 O is synthesized by the reaction of K 2 OsBr 6 with thiocarbamide in concentrated HBr and characterized using electronic absorption and IR absorption spectroscopy. Its crystal structure is determined by X-ray diffraction. The crystals are orthorhombic, a = 11.730(2) A, b = 14.052(3) A, c = 16.994(3) A, space group Cmcm, and Z = 4. The [OsBr 6 ] 2- anionic complex has an octahedral structure. The Os-Br distances fall in the range 2.483-2.490 A. The α,α'-dithiobisformamidinium cation is a product of the oxidation of thiocarbamide. The S-S and C-S distances are 2.016 and 1.784 A, respectively. The H 2 O molecules, Br - ions, and NH 2 groups of the cation are linked by hydrogen bonds.
International Nuclear Information System (INIS)
Duvieubourg, Laurence; Nowogrocki, Guy; Abraham, Francis; Grandjean, Stephane
2005-01-01
Two modifications of the new uranyl oxalate hydroxide dihydrate [UO 2 ) 2 (C 2 O 4 )(OH) 2 (H 2 O) 2 ] (1 and 2) and one form of the new uranyl oxalate hydroxide trihydrate [(UO 2 ) 2 (C 2 O 4 )(OH) 2 (H 2 O) 2 ].H 2 O (3) were synthesized by hydrothermal methods and their structures determined from single-crystal X-ray diffraction data. The crystal structures were refined by full-matrix least-squares methods to agreement indices R(wR)=0.0372(0.0842) and 0.0267(0.0671) calculated for 1096 and 1167 unique observed reflections (I>2σ(I)), for α (1) and β (2) forms, respectively and to R(wR)=0.0301(0.0737) calculated for 2471 unique observed reflections (I>2σ(I)), for 3. The α-form of the dihydrate is triclinic, space group P1-bar , Z=1, a=6.097(2), b=5.548(2), c=7.806(3)A, α=89.353(5), β=94.387(5), γ=97.646(5) o , V=260.88(15)A 3 , β-form is monoclinic, space group C2/c, Z=4, a=12.180(3), b=8.223(2), c=10.777(3)A, β=95.817(4), V=1073.8(5)A 3 . The trihydrate is monoclinic, space group P2 1 /c, Z=4, a=5.5095(12), b=15.195(3), c=13.398(3)A, β=93.927(3), V=1119.0(4)A 3 . In the three structures, the coordination of uranium atom is a pentagonal bipyramid composed of dioxo UO 2 2+ cation perpendicular to five equatorial oxygen atoms belonging to one bidentate oxalate ion, one water molecule and two hydroxyl ions in trans configuration in 2 and in cis configuration in 1 and 3. The UO 7 polyhedra are linked through hydroxyl oxygen atoms to form different structural building units, dimers [U 2 O 10 ] obtained by edge-sharing in 1, chains [UO 6 ] ∼ and tetramers [U 4 O 26 ] built by corner-sharing in 2 and 3, respectively. These units are further connected by oxalate entities that act as bis-bidentate to form one-dimensional chains in 1 and bi-dimensional network in 2 and 3. These chains or layers are connected in frameworks by hydrogen-bond arrays
Directory of Open Access Journals (Sweden)
Andrii I. Buvailo
2012-12-01
Full Text Available The reaction between copper(II nitrate and (E-N-(3-amino-2,2-dimethylpropyl-2-(hydroxyiminopropanamide led to the formation of the dinuclear centrosymmetric copper(II title complex, (C8H18N3O22[Cu2(C8H15N3O22(C8H17N3O22](C9H16N3O42·2CH3CN, in which an inversion center is located at the midpoint of the Cu2 unit in the center of the neutral [Cu2(C8H15N3O22(C8H17N3O22] complex fragment. The Cu2+ ions are connected by two N—O bridging groups [Cu...Cu separation = 4.0608 (5 Å] while the CuII ions are five-coordinated in a square-pyramidal N4O coordination environment. The complex molecule co-crystallizes with two molecules of acetonitrile, two molecules of the protonated ligand (E-3-[2-(hydroxyiminopropanamido]-2,2-dimethylpropan-1-aminium and two negatively charged (E-{3-[2-(hydroxyiminopropanamido]-2,2-dimethylpropyl}carbamate anions, which were probably formed as a result of condensation between (E-N-(3-amino-2,2-dimethylpropyl-2-(hydroxyiminopropanamide and hydrogencarbonate anions. In the crystal, the complex fragment [Cu2(C8H15N3O22(C8H17N3O22] and the ion pair C8H18N3O2+.C9H16N3O4− are connected via an extended system of hydrogen bonds.
Bocanegra-Ibarias, Paola; Garza-González, Elvira; Morfín-Otero, Rayo; Barrios, Humberto; Villarreal-Treviño, Licet; Rodríguez-Noriega, Eduardo; Garza-Ramos, Ulises; Petersen-Morfin, Santiago; Silva-Sanchez, Jesus
2017-01-01
To characterize the microbiological, molecular and epidemiological data of an outbreak of carbapenem-resistant Enterobacteriaceae (CRE) in a tertiary-care hospital in Mexico. From September 2014 to July 2015, all CRE clinical isolates recovered during an outbreak in the Hospital Civil "Fray Antonio Alcalde" in Jalisco, Mexico were screened for antimicrobial susceptibility, carbapenemase production, carbapenemase-encoding genes, and plasmid profiles. Horizontal transfer of imipenem resistance; and clonal diversity by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST); as well as biofilm production and the presence of 14 virulence genes were analyzed in selected isolates. Fifty-two carbapenem-resistant isolates corresponding to 5 species were detected, i.e., Klebsiella pneumoniae (n = 46), Enterobacter cloacae (n = 3), Escherichia coli (n = 1), Providencia rettgeri (n = 1) and Citrobacter freundii (n = 1) with carbapenemase encoding genes blaNDM-1 (n = 48), blaVIM (n = 3), blaIMP (n = 1) and blaKPC (n = 1) detected in these isolates. The blaNDM-1 gene was detected in plasmids from 130- to 170-kb in K. pneumoniae (n = 46); E. cloacae (n = 3), E. coli (n = 1) and P. rettgeri (n = 1). The transfer of plasmids harboring the blaNDM-1 gene was obtained in eight transconjugants. One plasmid restriction pattern was detected, with the blaNDM-1 identified in different restriction fragments. Predominant clone A of K. pneumoniae isolates archived 28/46 (60%) isolates and belongs to ST392. Besides, ST307, ST309, ST846, ST2399, and ST2400 were detected for K. pneumoniae; as well as E. cloacae ST182 and E. coli ST10. The fimA and uge genes were more likely to be identified in K. pneumoniae carbapenem-susceptible isolates (p = Enterobacteriaceae species harboring the blaNDM-1 gene were detected in a nosocomial outbreak in Mexico; horizontal transfer and strain transmission were demonstrated for the blaNDM-1 gene. Given the variation in the size of the
Gl(2/2)-oscillators and Gl(2/2)-dynamical symmetry
International Nuclear Information System (INIS)
Kamupingene, A.H.; Nguyen Anh Ky.
1991-07-01
Extending the concept of the dynamical symmetry, we identify the Lie superalgebra Gl(2/2) as a dynamical (super-)algebra of a class of non-canonical quantum systems, whose dynamical variables and quantities can be realized in terms of the Gl(2/2)-generators. In this way, a new class of harmonic oscillators is established. As a consequence of the choice of the dynamical variables the Heisenberg algebra and the Hermitian condition for the Gl(2/2)-representations are also given. (author). 12 refs
2-(2-Pyridylpyridinium (2,2′-bipyridine-κ2N,N′tetrakis(nitrato-κ2O,O′bismuthate(III
Directory of Open Access Journals (Sweden)
Shu-Shen Zhang
2011-10-01
Full Text Available The structure of the title compound, (C10H9N2[Bi(NO34(C10H8N2], consists of 2-(2-pyridylpyridinium cations and anions [Bi(NO34(C10H8N2]−. The Bi3+ ion lies on the twofold axis. It is coordinated by two nitrogen atoms from one 2,2′-bipyridine ligand and eight oxygen atoms from four NO3− anions. The disordered cation is positioned at the inversion centre. The [Bi(NO34(C10H8N2]− anions and 2-(2-pyridylpyridinium cations are connected via N—H...O hydrogen bonds into chains. Moreover, these chains are further linked into a two-dimensional layered structure through π–π stacking interactions between bipyridine ligands along the c axis [centroid–centroid distance = 2.868 (4 Å].
49 CFR 173.115 - Class 2, Divisions 2.1, 2.2, and 2.3-Definitions.
2010-10-01
... substances of Class 8, PG I are forbidden from transportation in an aerosol container. (7) Flammable... 2.1, 2.2, and 2.3—Definitions. (a) Division 2.1 (Flammable gas). For the purpose of this subchapter, a flammable gas (Division 2.1) means any material which is a gas at 20 °C (68 °F) or less and 101.3...
Gilbert-Wilson, Ryan; Field, Leslie D; Bhadbhade, Mohan M
2012-03-05
The synthesis and characterization of the extremely hindered phosphine ligands, P(CH(2)CH(2)P(t)Bu(2))(3) (P(2)P(3)(tBu), 1), PhP(CH(2)CH(2)P(t)Bu(2))(2) (PhP(2)P(2)(tBu), 2), and P(CH(2)CH(2)CH(2)P(t)Bu(2))(3) (P(3)P(3)(tBu), 3) are reported, along with the synthesis and characterization of ruthenium chloro complexes RuCl(2)(P(2)P(3)(tBu)) (4), RuCl(2)(PhP(2)P(2)(tBu)) (5), and RuCl(2)(P(3)P(3)(tBu)) (6). The bulky P(2)P(3)(tBu) (1) and P(3)P(3)(tBu) (3) ligands are the most sterically encumbered PP(3)-type ligands so far synthesized, and in all cases, only three phosphorus donors are able to bind to the metal center. Complexes RuCl(2)(PhP(2)P(2)(tBu)) (5) and RuCl(2)(P(3)P(3)(tBu)) (6) were characterized by crystallography. Low temperature solution and solid state (31)P{(1)H} NMR were used to demonstrate that the structure of RuCl(2)(P(2)P(3)(tBu)) (4) is probably analogous to that of RuCl(2)(PhP(2)P(2)(tBu)) (5) which had been structurally characterized.
Lozano Rivera, Raquel
2015-01-01
El trabajo de investigación que se recoge en la presente Memoria comprende un amplio estudio de la reactividad de complejos metálicos binucleares con ligandos puente difósforo y metildifosfenilo procedentes de la activación directa del fósforo blanco. Por un lado, se ha llevado a cabo un amplio análisis del comportamiento químico de la especie aniónica [Mo2Cp2(¿-PCy2)(¿-¿2:¿2-P2)(CO)2]- frente a electrófilos de distinta naturaleza, tales como clorofosfinas y complejos metálicos generadores...
Energy Technology Data Exchange (ETDEWEB)
Dubois, P.; Zenz, H.; Stehlik, G.; Kaindl, K. [Agence Europeenne pour l' Energie Nucleaire, Seibersdorf (Austria)
1966-11-15
contenian ya sustancias volatiles antes de la irradiacion. En los zumos de manzana, la irradiacion hace aparecer cinco aldehidos: acetico, isobutirico, butirico, isovalerico y capronico; en los zumos concentrados solo se han observado tres: acetico, isobutirico e isovalerico. En estos zumos concentrados aparece, ademas, 2-butanona p'ero en los no concentrados el maximo que le corresponde en los cromatogramas queda enteramente cubierto por el del etanol. Se ha comprobado la formacion de.furano y de dos compuestos que solo aparecen como vestigios y que no han podido ser aun identificados. Se han obtenido resultados analogos mediante pasterizacion realizada por embotellamiento en caliente. (author) [Russian] V ramkah Mezhdunarodnogo issledovatel'skogo proekta po konservirovaniju fruktov i fruktovyh sokov metodom obluchenija (Zajbersdorf) organolepticheskie issledovanija, a takzhe ispytanija na bezvrednost' delajut neobhodimym .provedenie analiza aromaticheskih veshhestv, obluchennyh i neobluchennyh sokov. Analizirovalis' letuchie veshhestva obluchennyh jablochnyh sokov metodom hromatografii v gazovoj faze putem neposredstvennogo vvedenija parov', ispuskaemyh sokami, libo pri rabochej temperature libo pri 60 Degree-Sign - 100 Degree-Sign (Head Space Techniguede Weurman). Identifikacija proizvodilas' putem sravnenija ob{sup e}mov uderzhanija s ob{sup e}mami chistyh veshhestv i pri pomoshhi himicheskih reaktivov, kotorye pozvoljali ustranjat' nekotorye komponenty para. Dlja uproshhenija analizov pervye issledovanija provodilis' s koncentratami jablochnyh sokov, ne soderzhavshih pered oblucheniem letuchih veshhestv. Pri obluchenii v jablochnom soke pojavljajutsja pjat' al'degidov: acetal'degid, izomaslja- nyj al'degid, masljanyj al'degid, izovaler'janovyj al'degid i kapronal'degid. V koncentrirovannyh sokah pojavljajutsja tol'ko tri al'degida: acetal'degid, izomasljanyj al'degid i izovaler'janovyj al'degid. Krome togo, v koncentrirovannyh sokah pojavljaetsja 2-butanon, no
International Nuclear Information System (INIS)
Chadha, S.L.; Uppal, K.
1987-01-01
VCl(OCH 2 CF 3 ) 2 and VCl 2 (OCH 2 CF 3 ) have been synthesised. They form complexes with monodentate oxygen or nitrogen donor ligands. The magnetic moments for these complexes indicate antiferromagnetic interactions and their electronic spectra are consistent with octahedral coordination of V(III) involving chloride, organoxy ions and the ligands. The i.r. spectra support the alkoxy-bridged structure for these complexes in which the ligands are probably cis to each other. 1 H nmr spectrum of VCl(OCH 2 CF 3 ) 2 shows a sharp quartet suggesting a sharp exchange of terminal and bridging alkoxy groups. 19 F nmr spectra of the parent compounds also show a single sharp band. The mass spectra suggest a dimeric form for both compounds in vapour phase
Fermi surfaces of YRu2Si2 and LaRu2Si2
International Nuclear Information System (INIS)
Settai, R.; Ikezawa, H.; Toshima, H.; Takashita, M.; Ebihara, T.; Sugawara, H.; Kimura, T.; Motoki, K.; Onuki, Y.
1995-01-01
We have measured the de Haas-van Alphen effect of YRu 2 Si 2 and LaRu 2 Si 2 to clarify the Fermi surfaces and cyclotron masses. Main hole-Fermi surfaces of both compounds with a distorted ellipsoid shape are similar, occupying about half of the Brillouin zone. The small hole-Fermi surfaces with the shape of a rugby ball are three in number for LaRu 2 Si 2 , and one for YRu 2 Si 2 . An electron-Fermi surface consists of a doughnut like shape for LaRu 2 Si 2 , while a cylinder along the [001] direction and a multiply-connected shape exist for YRu 2 Si 2 . The cyclotron masses of YRu 2 Si 2 are a little larger than those of LaRu 2 Si 2 . ((orig.))
International Nuclear Information System (INIS)
Adiguzel, Vedat; Erge, Hasan; Alisoglu, Vahit; Necefoglu, Hacali
2014-01-01
Highlights: • The physicochemical properties of ternary and one quaternary have been studied. • Reciprocal quaternary systems’ solubility and phase equilibrium have been studied. • In all systems the solid phases have been found. • It was found that Zn(H 2 PO 2 ) 2 salt contains 70% of the general crystallization field. - Abstract: The solubility and the physicochemical properties (density, viscosity) in the Na-Zn- Cl-H 2 O), (Na + Zn + H 2 PO 2 + H 2 O), (Na + Cl + H 2 PO 2 + H 2 O), and (Zn + Cl + H 2 PO 2 + H 2 O) ternaries, and in Na + , Zn 2+ /Cl − , (H 2 PO 2 ) − //H 2 O reciprocal quaternary systems at T = 273.15 K were investigated by using the isothermal method. The diagrams of ternary salts systems, (NaCl + ZnCl 2 + H 2 O), (NaCl + NaH 2 PO 2 + H 2 O), (NaH 2 PO 2 + Zn(H 2 PO 2 ) 2 + H 2 O), (ZnCl 2 + Zn(H 2 PO 2 ) 2 + H 2 O), are plotted in figures 1–4. However, whole ions of reciprocal quaternary salt systems are plotted in figure 5. Additionally, the density and viscosity values of ternary systems vs. their corresponding composition values in weight per cent are plotted in figures 6–10. At the (i) (ZnCl 2 + Zn(H 2 PO 2 ) 2 + H 2 O), (ii) (NaCl + ZnCl 2 + H 2 O), (iii) (NaCl + NaH 2 PO 2 + H 2 O), (iv) (NaH 2 PO 2 + Zn(H 2 PO 2 ) 2 + H 2 O) ternary systems the solid phase compositions have been determined as: (i) Zn(H 2 PO 2 ) 2 ⋅ H 2 O, Zn(H 2 PO 2 ) 2 , ZnCl 2 ⋅ 2H 2 O, (ii) NaCl, 2NaCl ⋅ ZnCl 2 ⋅ 2H 2 O, and ZnCl 2 ⋅ 2H 2 O, (iii) NaCl and NaH 2 PO 2 ⋅ H 2 O, (iv) Zn(H 2 PO 2 ) 2 ⋅ H 2 O and NaH 2 PO 2 ⋅ H 2 O, respectively. On the other hand reciprocal quaternary system was observed as: ZnCl 2 ⋅ 2H 2 O, 2NaCl ⋅ ZnCl 2 ⋅ 2H 2 O, Zn(H 2 PO 2 ) 2 ⋅ H 2 O, NaH 2 PO 2 ⋅ H 2 O, NaCl. According to results, the least soluble salt was Zn(H 2 PO 2 ) 2 . The crystallization field of this salt, being the largest in comparison with those of other salts, occupied 70% of the general crystallization field
1-Methoxy-3-o-tolylbicyclo[2.2.2]oct-5-ene-2,2-dicarbonitrile
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Orhan Büyükgüngör
2009-09-01
Full Text Available In the title compound, C18H18N2O, the cyclohexene and cyclohexane rings of the bicyclo[2.2.2]oct-5-ene unit adopt distorted boat conformations. In the crystal, molecules exist as C—H...N hydrogen-bonded centrosymmetric R22(14 dimers, which are further linked by C—H...π interactions.
4-Aza-1-azoniabicyclo[2.2.2]octane–2-aminobenzoate–2-aminobenzoic acid (1/1/1
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Hadi D. Arman
2011-11-01
Full Text Available A 4-aza-1-azoniabicyclo[2.2.2]octane cation, a 2-aminobenzoate anion and a neutral 2-aminobenzoic acid molecule comprise the asymmetric unit of the title compound, C6H13N2+·C7H6NO2−·C7H7NO2. An intramolecular N—H...O hydrogen bond occurs in the anion and in the neutral 2-aminobenzoic acid molecule. The cation provides a charge-assisted N—H...O hydrogen bond to the anion, and the 2-aminobenzoic acid molecule forms an O—H...N hydrogen bond to the unprotonated amino N atom in the cation. In this way, a three-component aggregate is formed. These are connected into a three-dimensional network by amino–carboxylate N—H...O hydrogen bonds. N—H...N hydrogen bonds are also observed.
Photolysis of H2O-H2O2 Mixtures: The Destruction of H2O2
Loeffler, M. J.; Fama, M.; Baragiola, R. A.; Carlson, R. W.
2013-01-01
We present laboratory results on the loss of H2O2 in solid H2O + H2O2 mixtures at temperatures between 21 and 145 K initiated by UV photolysis (193 nm). Using infrared spectroscopy and microbalance gravimetry, we measured the decrease of the 3.5 micrometer infrared absorption band during UV irradiation and obtained a photodestruction cross section that varies with temperature, being lowest at 70 K. We use our results, along with our previously measured H2O2 production rates via ionizing radiation and ion energy fluxes from the spacecraft to compare H2O2 creation and destruction at icy satellites by ions from their planetary magnetosphere and from solar UV photons. We conclude that, in many cases, H2O2 is not observed on icy satellite surfaces because the H2O2 photodestruction rate is much higher than the production rate via energetic particles, effectively keeping the H2O2 infrared signature at or below the noise level.
Bis(μ-biphenyl-2,2′-dicarboxylatobis[(2,2′-bipyridinecopper(II
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Zhe An
2009-04-01
Full Text Available The title compound, [Cu2(C14H8O42(C10H8N22], was obtained by solvothermal synthesis. The CuII atom is coordinated by one chelating 2,2′-bipyridine ligand and two carboxyl groups from different biphenyl-2,2′-dicarboxylate ligands, leading to a distorted octahedral environment. Each carboxylate group makes one short Cu—O bond [1.9608 (14 and 1.9701 (14 Å] and one longer Cu—O contact [2.4338 (17 and 2.5541 (17 Å] to each CuII atom. The biphenyl-2,2′-dicarboxylate ligands bridge between CuII atoms, forming a dinuclear complex around a crystallographic inversion centre.
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Inna Seifullina
2016-12-01
Full Text Available The crystalline compounds (Hbipy2[Ge(HCit2]·2H2O (1 and CuCl(bipy2]2[Ge(HCit2]·8H2O (2 (where H4Cit is citric acid, bipy is 2,2ʹ-bipyridine were obtained for the fi rst time and their structures were determined by the single-crystal X-ray diffraction method. Compounds were characterized by IR spectroscopy, thermogravimetric (TGA and elemental analyses. Both compounds are formed with complex bis(citrategermanate anion and protonated 2,2’-bipyridine or [Cu(bipy2Cl]+ as cations in compounds 1 and 2, respectively.
synthesis and structural characterization of n-(2-{[(2e)-2-(2 ...
African Journals Online (AJOL)
E.J. Research Institute of Chemistry, International Center for Chemical and Biological ... Benzamide and its analogues have various application in synthesis of ..... Symmetry codes: (i) x+3/2, y+1/2, z; (ii) −x+1/2, −y+1/2, −z; (iii) x, y−1, z.
Cryptand [2.2.2]quantitation in the synthesis of 2-[fluorine-18]fluoro-2-deoxy-d-glucose
International Nuclear Information System (INIS)
Kothari, P.J.; Ginos, J.; Finn, R.D.; Larson, S.M.; Link, J.M.; Krohn, K.A.; Garmestani, K.
1992-01-01
Most automated synthetic devices for the preparation of [ 18 F]2-fluoro-2-deoxy-D-glucose ([ 18 F]FDG) employ cryptand [2.2.2](4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo(8.8.8)-hexacosane) to facilitate the 18 F displacement reaction. Lack of simple spectroscopic and/or chromatographic determinations for cryptands prompted our investigation with tritiated [2.2.2] cryptand reagent to determine the absolute concentration of this reagent throughout the synthetic procedure leading to the final formulation. The concentration of cryptand [2.2.2] in the final formulation has been determined to range from 0.39 μg/ml to 0.60 μg/ml which is well below the detection limit by a method recently reported. (author) 1 fig., 1 tab., 5 refs
Energy Technology Data Exchange (ETDEWEB)
Tsutsumi, K.; Otake, J.; Nagasaka, T.; Hino, M. [Tohoku University, Sendai (Japan)
1998-06-01
It has been known that crystallization of mold powder is effective on the disturbance of heat transfer between mold and solidified shell in production of middle carbon steel slabs in continuous casting process. But it has not yet been made clear which composition of mold powder is the most suitable for crystallization. The crystallization behavior of Li2O-SiO2, Na2O-SiO2 and Na2O-CaO-SiO2 glasses was observed by differential thermal analysis (DTA) and hot-thermocouple methods with DTA in the present work. As a result, addition of alkaline metal and alkaline earth metal oxides to SiO2 increased the critical cooling rate for glass formation in binary system of Li2O-SiO2 and Na2O-SiO2 and Li2O-SiO2 system crystallized easier than Na2O-SiO2 system. In ternary system of Na2O-CaO-SiO2, addition of Na2O hurried the critical cooling rate at CaO/SiO2=0.93 mass ratio, but the rate was almost constant in the composition range of more than 15 mass% Na2O. The slag of CaO/SiO2=0.93 made the rate faster than the slag of CaO/SiO2=0.47 at constant content of 10mass% Na2O. 17 refs., 10 figs., 3 tabs.
International Nuclear Information System (INIS)
Petrosyants, S.P.; Ilyukhin, A.B.
2005-01-01
Compounds with general formula Cat x [Sc(H 2 O) z (SO 4 ) y ]·nH 2 O (Cat=NH 4 , H 2 Bipy (Bipy - 4,4'-bipyridine), HEdp (Edp - ethylene dipyridine)) identified on element analysis data and IR spectra are synthesized. X-ray diffraction analysis of (H 2 Bipy)[Sc(H 2 O)(SO 4 ) 2 ] 2 ·2H 2 O shows that in structure of the compound chains of ScO 6 octahedron and SO 4 tetrahedrons are joined in bands by tridentate coordination of sulfate ions. Bands form skeleton in endless emptiness of which there are H 2 Bipy 2+ cations [ru
Excitation mechanisms of 2s1/2-2p3/2 and 2p1/2-2p3/2 transitions in U82+ through U89+
International Nuclear Information System (INIS)
Decaux, V.; Beiersdorfer, P.; Osterheld, A.
1994-01-01
A model based on detailed calculations of the electron-impact excitation of n = 2 electrons in the Li- to Ne-like uranium ions was developed to interpret and explain measurements on EBIT (Electron Beam Ion Trap). While only considering the direct excitation process provided a good model for the electric dipole (El) transitions, it was necessary for the magnetic dipole (Ml) spectrum to include various additional excitation processes in the model. In particular, the model was expanded to include electron-impact excitation of n = 3 levels followed by radiative cascades. Moreover, excitation by the ionization of 2s 1/2 , 2p 1/2 , and 2p 3/2 electrons and by radiative capture of beam electrons into excited levels was added. The new model demonstrates that the dipole-forbidden lines are almost exclusively produced by indirect excitation processes
Selective fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene by nucleotides.
Marquez, Cesar; Pischel, Uwe; Nau, Werner M
2003-10-16
[reaction: see text] The fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) by nucleotides has been studied. The quenching mechanism was analyzed on the basis of deuterium isotope effects, tendencies for exciplex formation, and the quenching efficiency in the presence of a molecular container (cucurbit[7]uril). Exciplex-induced quenching appears to prevail for adenosine, cytidine, and uridine, while hydrogen abstraction becomes competitive for thymidine and guanosine. Compared to other fluorescent probes, DBO responds very selectively to the type of nucleotide.
National Aeronautics and Space Administration — This dataset consists of the version 2 Level 2B science-quality ocean surface wind vector retrievals from the Oceansat-2 scatterometer (OSCAT), which was designed...
Mondal, Bijan; Bag, Ranjit; Ghorai, Sagar; Bakthavachalam, K; Jemmis, Eluvathingal D; Ghosh, Sundargopal
2018-04-26
The reaction of [(Cp*Mo) 2 (μ-Cl) 2 B 2 H 6 ] (1) with CO at room temperature led to the formation of the highly fluxional species [{Cp*Mo(CO) 2 } 2 {μ-η 2 :η 2 -B 2 H 4 }] (2). Compound 2, to the best of our knowledge, is the first example of a bimetallic diborane(4) conforming to a singly bridged C s structure. Theoretical studies show that 2 mimics the Cotton dimolybdenum-alkyne complex [{CpMo(CO) 2 } 2 C 2 H 2 ]. In an attempt to replace two hydrogen atoms of diborane(4) in 2 with a 2e [W(CO) 4 ] fragment, [{Cp*Mo(CO) 2 } 2 B 2 H 2 W(CO) 4 ] (3) was isolated upon treatment with [W(CO) 5 ⋅thf]. Compound 3 shows the intriguing presence of [B 2 H 2 ] with a short B-B length of 1.624(4) Å. We isolated the tungsten analogues of 3, [{Cp*W(CO) 2 } 2 B 2 H 2 W(CO) 4 ] (4) and [{Cp*W(CO) 2 } 2 B 2 H 2 Mo(CO) 4 ] (5), which provided direct proof of the existence of the tungsten analogue of 2. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Energy Technology Data Exchange (ETDEWEB)
Chumakov, Yu. M. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Paladi, L. G. [Moldova State University (Moldova, Republic of); Antosyak, B. Ya.; Simonov, Yu. A. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Tsapkov, V. I., E-mail: vtsapkov@gmail.com [Moldova State University (Moldova, Republic of); Bocelli, G. [Institute of Materials for Electronics and Magnetism (Italy); Gulea, A. P. [Moldova State University (Moldova, Republic of); Ginju, D. [Alexandru Ioan Cuza University of Iasi (Romania); Palomares-Sanchez, S. A. [Autonomous University of San Luis Potosi (Mexico)
2011-03-15
Nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2 Prime -bipyridyl)copper (I) and nitrato-(2-hydroxybenzaldehydo)(2,2 Prime -bipyridyl)copper (II) were synthesized and characterized by X-ray diffraction. The coordination polyhedron of the central copper atom in complex I can be described as a distorted tetragonal pyramid whose base is formed by the phenol and carbonyl oxygen atoms of the monodeprotonated 2-hydroxy-5nitrobenzaldehyde molecule and the nitrogen atoms of the 2,2 Prime -bipyridyl ligand and whose apex is occupied by the oxygen atom of the nitrato group. In the crystal structure, complexes I are linked by the acido ligands and the NO{sub 2} groups of the aldehyde molecule into infinite chains. In complex II, the central copper atom is coordinated by 2-hydroxybenzaldehyde, 2,2 Prime -bipyridyl, and the nitrato group, resulting in the formation of centrosymmetric dimers. The coordination polyhedron of the central copper atom can be described as a bipyramid (4 + 1 + 1) with the same base as in complex I. The axial vertices of the bipyramid are occupied by the oxygen atom of the nitrato group and the bridging phenol oxygen atom of the adjacent complex related to the initial complex by a center of symmetry. In the crystal structure, complexes II are hydrogen bonded into infinite chains.
Micropore Formation of [Zn2(Oxac) (Taz)2]·(H2O)2.5 via CO2 Adsorption.
Zubir, Moondra; Hamasaki, Atom; Iiyama, Taku; Ohta, Akira; Ohki, Hiroshi; Ozeki, Sumio
2017-01-24
As-synthesized [Zn 2 (Oxac) (Taz) 2 ]·(H 2 O) 2.5 , referred to as ZOTW 2.5 , was prepared from aqueous methanol solutions of Zn 5 (CO 3 ) 2 (OH) 6 and two kinds of ligands of 1,2,4-triazole (Taz) and oxalic acid (Oxac) at 453 K for 12 h. The crystal structure was determined by the Rietveld method. As-synthesized ZOTW 2.5 was pretreated at 383 K and 1 mPa for t pt h, ZOTW x (t pt h). ZOTW x (≥3h) showed a type I adsorption isotherm for N 2 at 77 K having a saturation amount (V s ) of 180 mg/g, but that pretreated shortly showed only 1/10 in V s . CO 2 was adsorbed at 303 K in sigmoid on nonporous ZOTW x (≤2h) and in Langmuir-type on ZOTW x (≥3h) to reach the adsorption amount of 120 mg/g at 700 Torr. N 2 adsorption on ZOTW x (≤2h)deCO 2 , degassed after CO 2 adsorption on ZOTW x (≤2h), was promoted 5-fold from 180 mg/g on ZOTW x (t pt h) and ZOTW x (≥3h)deCO 2 up to ca. 1000 mg/g. The interaction of CO 2 and H 2 O molecules in micropores may lead to a new route for micropore formation.
International Nuclear Information System (INIS)
Charushnikova, I.A.; Krot, N.N.; Starikova, Z.A.
2009-01-01
Single crystals were prepared, and the structures of two complexes of Np(V) glycolate with 2,2'-bipyridine of the compositions [NpO 2 (C 10 H 8 N 2 )(OOC 2 H 2 OH)].1.5H 2 O (I) and [NpO 2 (C 10 H 8 N 2 )(OOC 2 H 2 OH)]2.5H 2 O (II) were studied. The structures of the compounds are based on neptunyl-glycolate chains in which the glycolate anion manifests its complexation ability in different manner. In structure I, the bidentate-bridging anion links the adjacent NpO 2 - cations through the oxygen atoms of the carboxylate group. The neptunyl-glycolate chains of I exhibits the mutual coordination of the NpO 2 - cations acting toward each other simultaneously as ligands and coordinating centers. In compound II, the glycolate anion is bidentately coordinated to one neptunium atom to form a planar five-membered metallocycle [NpOCCO]. The O atom external with respect to the metallocycle is in the coordination environment of the adjacent neptunyl. The nitrogen-containing molecular ligand Bipy is included into the coordination environment of Np. The coordination polyhedron of the Np atoms in both structures is a pentagonal bipyramid in which the average Np-N bond length is 2.666 Aa (I) and 2.596 Aa (II). (orig.)
Enatioselective[2+2+2] Cycloaddition as A Synthetic Tool
Institute of Scientific and Technical Information of China (English)
T.Shibata; S.Yoshida; M.Otsuka; Y.Arai; K.Endo
2007-01-01
1 Results Transition metal-catalyzed [2+2+2] cycloaddition is one of the most efficient protocols for the construction of six-membered ring system.Our group has comprehensively studied various types of highly enantioselective [2+2+2] cycloaddition for the synthesis of chiral cycloadducts; we already reported an iridium-catalyzed intermolecular [2+2+2] cycloaddition between α,ω-diynes,having various tethers and substituents on the alkyne termini,and monoalkynes,possessing oxygen or/and nitrogen functiona...
Directory of Open Access Journals (Sweden)
E. MAKRLÍK
2008-12-01
Full Text Available The exchange extraction constants corresponding to the general equilibrium M2+(aq + SrL2+(nb D ML2+ (nb + Sr2+ (aq occurring in the two-phase water–nitrobenzene system (M2+ = Ca2+, Ba2+, Cu2+, Zn2+, Cd2+, Pb2+, UO22+, Mn2+, Co2+ or Ni2+; L = tetra-tert-butyl p-tert-butylcalix[4]arene tetraacetate; aq = aqueous phase; nb = nitrobenzene phase were evaluated from extraction experiments and -activity measurements. Furthermore, the stability constants of the ML2+ complexes in water saturated nitrobenzene were calculated; they were found to increase in the cation order Ba2+ < Mn2+ < Pb2+, Co2+ < Cu2+, Zn2+ < Cd2+, Ni2+ < UO22+ < Ca2+.
Domańska-Babul, Wioleta; Chojnacki, Jaroslaw; Matern, Eberhard; Pikies, Jerzy
2009-01-07
The reactions of lithium derivatives of diphosphanes R(2)P-P(SiMe(3))Li (R = (t)Bu, (i)Pr, Et(2)N and (i)Pr(2)N) with [(R'(3)P)(2)PtCl(2)] (R'(3)P = Et(3)P, Et(2)PhP, EtPh(2)P and p-Tol(3)P) proceed in a facile manner to afford side-on bonded phosphanylphosphinidene complexes of platinum [(eta(2)-P=R(2))Pt(PR'(3))(2)]. The related reactions of Ph(2)P-P(SiMe(3))Li with [(R'(3)P)(2)PtCl(2)] did not yield [(eta(2)-P=PPh(2))Pt(PR'(3))(2)] and resulted mainly in the formation of [{(R'(3)P)(2)Pt}(2)P(2)], Ph(2)P-PLi-PPh(2), (Me(3)Si)(2)PLi and (Me(3)Si)(3)P. Crystallographic data are reported for the compounds [(eta(2)-P=R(2))Pt(p-Tol(3)P)(2)] (R = (t)Bu, (i)Pr, ((i)Pr(2)N)(2)P) and for [{(Et(2)PhP)(2)Pt}(2)P(2)].
Study of Paramagnetic Monohydrates MeSO4.1H2O (Me = Mn2+, Co2+, Fe2+, Ni2+, Cu2+
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Jelšovská Kamila
2000-09-01
Full Text Available Nuclear magnetic resonance (NMR of protons of crystrallization water in isomorphous paramagnetic monohydrates MeSO4.1H2O with Me = Mn2+ , Co2+ , Fe2+ , Ni2+ , Cu2+ is studied in the present paper. Several physically important parameters characterizing the studied substances were derived from the NMR spectra. In this paper we analysed the dependences of the NMR second moment M2 on the magnitude of the external magnetic field induction Br and the temperature. The proton NMR spectra in paramagnetic hydrates have an asymmetric form caused by the anisotropy of the local magnetic field acting on resonating nuclei and their second moments, M2, depend linearly on the square of the external magnetic field Br. The parameters M20 (the part of the second moment M2 which corresponds to the nuclear dipole-dipole interactions and á which characterize nuclear dipole-dipole interactions of protons and paramagnetic ions, respectively, are derived from experimentally obtained dependences of M2 vs Br2. The measurements were performed at the room temperature. Calculations were realized using the approximation where two nearest neighbour ions Me2+ to each water molecule are considered. The temperature dependence of the second moment, which was realised in the temperature range 123-313 K, was more informative than the field one. Besides the individual dependences M2(T measured at fr1 and fr2 we analysed the temperature dependence of the difference ∆M2(T. Beside the second moment M20 the Curie-Weiss constant è and the magnetic moment µi of paramagnetic ions were determined from the temperature dependences. The parameters è and M20 were determined directly from the experimental data. Some knowledge on the crystalline structure for the studied substance was required for the calculation of the magnetic moment µi. By means of the classification of substances according to the Curie-Weiss parameter, the negative value of the temperature parameter è for all studied
Duguid, J G; Bloomfield, V A; Benevides, J M; Thomas, G J
1995-01-01
Differential scanning calorimetry, laser Raman spectroscopy, optical densitometry, and pH potentiometry have been used to investigate DNA melting profiles in the presence of the chloride salts of Ba2+, Sr2+, Mg2+, Ca2+, Mn2+, Co2+, Ni2+, and Cd2+. Metal-DNA interactions have been observed for the molar ratio [M2+]/[PO2-] = 0.6 in aqueous solutions containing 5% by weight of 160 bp mononucleosomal calf thymus DNA. All of the alkaline earth metals, plus Mn2+, elevate the melting temperature of ...
Blank, L. Aaron; Sharma, Amit R.; Weeks, David E.
2018-03-01
The X Σ 1 /2 +2 , A Π 1 /2 2 , A Π 3 /2 2 , and B2Σ1/2 + potential-energy curves for Rb+He are computed at the spin-orbit multireference configuration interaction level of theory using a hierarchy of Gaussian basis sets at the double-zeta (DZ), triple-zeta (TZ), and quadruple-zeta (QZ) levels of valence quality. Counterpoise and Davidson-Silver corrections are employed to remove basis-set superposition error and ameliorate size-consistency error. An extrapolation is performed to obtain a final set of potential-energy curves in the complete basis-set (CBS) limit. This yields four sets of systematically improved X Σ 1 /2 +2 , A Π 1 /2 2 , A Π 3 /2 2 , and B2Σ1/2 + potential-energy curves that are used to compute the A Π 3 /2 2 bound vibrational energies, the position of the D2 blue satellite peak, and the D1 and D2 pressure broadening and shifting coefficients, at the DZ, TZ, QZ, and CBS levels. Results are compared with previous calculations and experimental observation.
Directory of Open Access Journals (Sweden)
Daqi Wang
2008-12-01
Full Text Available The title complex, [Mn3(C11H6O34(C5H5N6(H2O2]·2H2O·2C5H5N, is a trinuclear mixed oxidation state complex of overline1 symmetry. The three Mn atoms are six-coordinated in the shape of distorted octahedra, each coordinated with an O4N2 set of donor atoms, where the ligands exhibit mono- and bidentate modes. However, the coordination of the MnII ion located on the inversion centre involves water molecules at two coordination sites, whereas that of the two symmetry-related MnIII ions involves an O4N2 set of donor atoms orginating from the organic ligands. Intramolecular C—H...π interactions between neighbouring pyridine ligands stabilize this arrangement. A two-dimensional network parallel to (001 is formed by intermolecular O—H...O hydrogen bonds.
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Matthew R. Carbone
2014-11-01
Full Text Available The title compounds, C22H31NO2S, (1, and C23H33NO2S, (2, are related protected 1,2-amino alcohols. They differ in the substituents on the benzene ring, viz. 2,6-dimethylphenyl in (1 and 2,4,6-trimethylphenyl in (2. The plane of the phenyl ring is inclined to that of the benzene ring by 28.52 (7° in (1 and by 44.65 (19° in (2. In the crystal of (1, N—H...O=S and C—H...O=S hydrogen bonds link molecules, forming chains along [100], while in (2, similar hydrogen bonds link molecules into chains along [010]. The absolute structures of both compounds were determined by resonance scattering.
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French Frank S
2004-08-01
Full Text Available Abstract Background The HE2 gene encodes a group of isoforms with similarities to the antimicrobial beta-defensins. We demonstrated earlier that the antimicrobial activity of HE2 proteins and peptides is salt resistant and structure dependent and involves permeabilization of bacterial membranes. In this study, we further characterize the antimicrobial properties of HE2 peptides in terms of the structural changes induced in E. coli and the inhibition of macromolecular synthesis. Methods E. coli treated with 50 micro g/ml of HE2alpha, HE2beta1 or HE2beta2 peptides for 30 and 60 min were visualized using transmission and scanning electron microscopy to investigate the impact of these peptides on bacterial internal and external structure. The effects of HE2alpha, HE2beta1 and HE2beta2 on E. coli macromolecular synthesis was assayed by incubating the bacteria with 2, 10 and 25 micro g/ml of the individual peptides for 0–60 min and measuring the incorporation of the radioactive precursors [methyl-3H]thymidine, [5-3H]uridine and L-[4,5-3H(N]leucine into DNA, RNA and protein. Statistical analyses using Student's t-test were performed using Sigma Plot software. Values shown are Mean ± S.D. Results E. coli treated with HE2alpha, HE2beta1 and HE2beta2 peptides as visualized by transmission electron microscopy showed extensive damage characterized by membrane blebbing, thickening of the membrane, highly granulated cytoplasm and appearance of vacuoles in contrast to the smooth and continuous membrane structure of the untreated bacteria. Similarly, bacteria observed by scanning electron microscopy after treating with HE2alpha, HE2beta1 or HE2beta2 peptides exhibited membrane blebbing and wrinkling, leakage of cellular contents, especially at the dividing septa, and external accumulation of fibrous materials. In addition, HE2alpha, HE2beta1 and HE2beta2 peptides inhibited E. coli DNA, RNA and protein synthesis. Conclusions The morphological changes observed
Koten, G. van; Ploeg, A.F.M.J. van der; Schmitz, J.E.J.; Linden, J.G.M. van der
1982-01-01
The organoplatinum(II) compounds [{2, 6-(Me{2}NCH{2}){2}C{6}H{3}}PtBr] and cis-[(C-N){2}Pt] (C-N = 2-Me{2}NCH{2}C{6}H{4}, 2-Me{2}NC{6}H{4}CH{2}) can be chemically irreversibly oxidized in the potential range 1.00 to 1.35 V vs. an Ag/AgCl electrode, whereas the organoplatinum@?mercury complexes
International Nuclear Information System (INIS)
Jiang Hui; Li Haoran; Wang Congmin; Tan Taijun; Han Shijun
2003-01-01
The isothermal and isobaric (vapour + liquid) equilibria for (2,2-dimethoxypropane + methanol) and (2,2-dimethoxypropane + acetone) measured with an inclined ebulliometer are presented. The experimental results are analysed using the UNIQUAC equation with the temperature-dependent binary parameters with satisfactory results. Isobaric (vapour + liquid) equilibria data for these systems at p=99.99 kPa are compared with the literature data. Experimental vapour pressure of 2,2-dimethoxypropane are also included
Phase diagrams of systems of Sr2V2O7-M2V2O7 and of Ba2V2O7-M2V2O7 (M=Ca,Cd)
International Nuclear Information System (INIS)
Fotiev, A.A.; Zhuravlev, V.D.; Zhukov, V.P.
1982-01-01
Using the methods of X-ray phase and differential thermal anlyses phase equilibria in the systems Sr 2 V 2 O 7 -M 2 V 2 O 7 and Ba 2 V 2 O 7 -M 2 V 2 O 7 , where M--Ca, Cd, are studied, their phase diagrams being built. New double pyrovanadates Mosub(0.5)Srsub(1.5)Vsub(2)Osub(7) and MBaV 2 O 7 are found [ru
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Kaijun Luo
2011-11-01
Full Text Available The title compound, [Ir(C11H8N2(C17H19O2], has an octahedral coordination geometry around the IrIII atom, retaining the cis-C,C,trans–N,N chelate disposition of the two 2-phenylpyridine ligands. The chelate rings are nearly mutually perpendicular [the interplanar angles range from 85.48 (17 to 89.17 (19°]. The two 2-(2-pyridylphenyl ligands are approximately planar, with the plane of the phenyl ring being inclined to that of the pyridine ring by 2.3 (3 and 5.1 (3° in the two ligands. The interplanar angle between the phenyl ring in 3-benzoyl-camphor and the IrO2C3 chelate ring is 35.5 (2°.
4-Aza-1-azoniabicyclo?[2.2.2]octa?ne?2-amino?benzoate?2-amino?benzoic acid (1/1/1)
Arman, Hadi D.; Kaulgud, Trupta; Tiekink, Edward R. T.
2011-01-01
A 4-aza-1-azoniabicyclo[2.2.2]octane cation, a 2-aminobenzoate anion and a neutral 2-aminobenzoic acid molecule comprise the asymmetric unit of the title compound, C6H13N2+·C7H6NO2−·C7H7NO2. An intramolecular N—H...O hydrogen bond occurs in the anion and in the neutral 2-aminobenzoic acid molecule. The cation provides a charge-assisted N—H...O hydrogen bond to the anion, and the 2-aminobenzoic acid molecule forms an O—H...N hydrogen bo...
Investigation into the MgF2-NiF2, CaF2-NiF2, SrF2-NiF2 systems
International Nuclear Information System (INIS)
Ikrami, D.D.; Petrov, S.V.; Fedorov, P.P.; Ol'khovaya, L.A.; Luginina, A.A.; AN SSSR, Moscow. Inst. Fizicheskikh Problem; AN SSSR, Moscow. Inst. Kristallografii)
1984-01-01
Using the methods of differential thermal and X-ray phase analyses the systems MgF 2 -NiF 2 , CaF 2 -NiF 2 , SrF 2 -NiF 2 have been studied. In the system SrF 2 -NiF 2 the only orthorhombic compounds SrNiF 4 (a=14.43; b=3.93; c=5.66 (+-0.01 A)) is formed. SrNiF 4 density constitutes: dsub(X-ray)=4.60+-0.01 g/cm 3 , dsub(exp.)=4.60+-0.03 g/cm 3 . Refraction indices are as follows SrNiF 4 :Ng=1.500; Nsub(m)=1.497; Nsub(p)=1.479. SrNiF 4 magnetic ordering temperature Tsub(N) approximately 100 K
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Raja Jouini
2012-12-01
Full Text Available Disodium molybdenum dioxide diarsenate, Na2MoO2As2O7, has been synthesized by a solid-state reaction. The structure is built up from MoAs2O12 linear units sharing corners to form a three-dimensional framework containing tunnels running along the a-axis direction in which the Na+ cations are located. In this framework, the AsV atoms are tetrahedrally coordinated and form an As2O7 group. The MoVI atom is displaced from the center of an octahedron of O atoms. Two Na+ cations are disordered about inversion centres. Structural relationships between different compounds: A2MoO2As2O7 (A = K, Rb, AMOP2O7 (A = Na, K, Rb; M = Mo, Nb and MoP2O7 are discussed.
Physical properties and the Peierls instability of Li0.82[Pt(S2C2(CN)2)2] · 2H2O
DEFF Research Database (Denmark)
Ahmad, M. M.; Turner, D. J.; Underhill, A. E.
1984-01-01
The infrared reflectivity, the temperature-dependent conductivity, and thermopower of the one-dimensional conductor Li0.82[Pt(S2C2(CN)2)2] · 2H2O, LiPt(mnt), is presented. It undergoes a simple Peierls transition at Tc=215 K, which is not influenced by correlations or by cation ordering. The meta...
On the simultaneous Pell equations x 2 - (4m 2 - 1)y 2 = y 2 - pz 2 ...
African Journals Online (AJOL)
Let m be a positive integer, and let p be an odd prime. By using certain properties of Pell and quartic diophantine equations with some elementary number theory methods, we prove that the system of equations x2 - (4m2 - 1)y2 = 1 and y2 - pz2 = 1 has positive integer solutions (x, y, z) if and only if p ≡ 7(mod 8) and m = 1/4 ...
Photoluminescence properties of Eu2+-activated Ca2Y2Si2O9 phosphor
Zhang, Zhijun; Delsing, A.C.A.; Notten, P.H.L.; Zhao, Jingtai; Hintzen, H.T.J.M.
2012-01-01
Eu2+-activated Ca2Y2Si2O9 phosphors with different Eu2+ concentrations have been prepared by a solid-state reaction method at high temperature and their photoluminescence (PL) properties were investigated. Photoluminescence results show that Eu2+-doped Ca2Y2Si2O9 can be efficiently excited by
161Dy Moessbauer spectroscopy of the intermetallic compounds DyNi2Si2, DyNi2Ge2 and DyAg2Si2
International Nuclear Information System (INIS)
Onodera, Hideya; Murata, Akifumi; Koizuka, Masaaki; Ohashi, Masayoshi; Yamaguchi, Yasuo
1994-01-01
161 Dy Moessbauer spectroscopic study has been performed on DyNi 2 Si 2 , DyNi 2 Ge 2 and DyAg 2 Si 2 in order to clarify microscopic properties of antiferromagnets with incommensurate and sinusoidally moment-modulated structure. The experiments were done using the standard 161 Tb Moessbauer sources prepared by neutron irradiation at the Japan Material Testing Reactor. The Moessbauer spectra of DyNi 2 Si 2 are analyzed satisfactorily by a single set of hyperfine parameters, and hence the sinusoidal moment-modulation is considered to be realized through a distribution of spin relaxation rate. The broadened spectra of DyNi 2 Ge 2 are fitted tentatively by three subspectra. It seems for DyNi 2 Ge 2 that the incommensurate arrangement of Dy moments differed in magnitude as well as the distribution of spin relaxation rate originates the moment modulation. The fact that the spectrum of DyAg 2 Si 2 at 3 K consists of two distinct subspectra ensures the complicated antiferromagnetic structure where two kinds of Dy moments differed in magnitude are arranged noncollinearly. (author)
2-Methylpropan-2-aminium 2-(methoxycarbonylbenzoate
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Jian Li
2011-10-01
Full Text Available In the title compound, C4H12N+·C9H7O4−, two C atoms and the N atom of the cation lie on a mirror plane, while all the atoms of the anion are disordered about a mirror plane. In the crystal, N—H...O hydrogen bonds link the components into chains along [010]. In the anion, the mean planes of the methoxycarbonyl and carboxylate groups form dihedral angles of 83.0 (2 and 83.2 (2°, respectively, with the aromatic ring.
Theoretical study on the photolysis mechanism of 2,3-diazabicyclo[2.2.2]oct-2-ene.
Chen, Hui; Li, Shuhua
2005-09-28
A CASPT2/CASSCF study has been carried out to investigate the mechanism of the photolysis of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) under direct and triplet-sensitized irradiation. By exploring the detailed potential energy surfaces including intermediates, transition states, conical intersections, and singlet/triplet crossing points, for the first excited singlet (S(1)) and the low-lying triplet states (T(1), T(2), and T(3)), we provide satisfactory explanations of many experimental findings associated with the photophysical and photochemical processes of DBO. A key finding of this work is the existence of a significantly twisted S(1) minimum, which can satisfactorily explain the envelope of the broad emission band of DBO. It is demonstrated that the S(1) (n-pi*) intermediate can decay to the T(1) (n-pi*) state by undergoing intersystem crossing (rather inefficient) to the T(2) (pi-pi*) state followed by internal conversion to the T(1) state. The high fluorescence yield and the extraordinarily long lifetime of the singlet excited DBO are due to the presence of relatively high barriers, both for intersystem crossing and for C-N cleavage. The short lifetime of the triplet DBO is caused by fast radiationless decay to the ground state.
Koten, G. van; Maassarani, F.; Davidson, M.F.; Wehman-Ooyevaar, ICM; Grove, D.M.; Koten, M.A. van; Smeets, W.J.J.; Spek, A.L.
1995-01-01
Reaction of diphenylphosphine with the complexes [Pt(NCN)(H{2}O)]X (NCN = C{6}H{3}(CH{2}NMe{2}){2}-2, 6; X = BF{4} (1a), OSO{2}CF{3} (1b)) leads to substitution of the H{2}O ligand to afford the ionic Pt(II) complexes [Pt(NCN)(PHPh{2})]X (X = BF{4} (2a), OSO{2}CF{3} (2b)). The X-ray structure of the
The synthesis of [2-3H2] taurine and [2-3H2] hypotaurine
International Nuclear Information System (INIS)
Fellman, J.H.
1981-01-01
The synthesis of [2- 3 H 2 ]-2-aminoethanesulfonate [2- 3 H]-taurine by the reduction of cyanomethanesulfonic acid with tritium gas is described. The conversion of [2- 3 H]-taurine and its 14 C and 35 S isotopic forms to 2-aminoethanesulfinate (hypotaurine) was accomplished by converting taurine to its corresponding sulfonyl chloride and reducing the latter with metallic zinc. (author)
Crystal and molecular structure of 2,2’-(quinoxaline-2,3-diyl)dipyridinium dinitrate (H_2L)(NO_3)_2
International Nuclear Information System (INIS)
Egorova, O. A.; Polyakova, I. N.; Sergienko, V. S.; Davydov, V. V.
2016-01-01
The crystal structure of 2,2’-(quinoxaline-2,3-diyl)dipyridinium dinitrate (H_2L)(NO_3)_2 is studied by X-ray diffraction (T = 150 K, R1 = 0.0467). The H_2L"2"+ cation is located on the twofold rotation axis and connected with two NO_3"− anions by strong N–H···O hydrogen bonds. Planar quinoxaline fragments of cations form stacks with the interplanar spacing of 3.308 Å. The structure of the diprotonated H_2L"2"+ cation is compared with those of the monoprotonated H_2L"2"+ cation and neutral L molecule.
Magnetism of CuCl{sub 2}·2D{sub 2}O and CuCl{sub 2}·2H{sub 2}O, and of CuBr{sub 2}·6H{sub 2}O
Energy Technology Data Exchange (ETDEWEB)
DeFotis, G.C., E-mail: gxdefo@wm.edu [Department of Chemistry, College of William and Mary, Williamsburg, VA 23187 (United States); Hampton, A.S.; Van Dongen, M.J.; Komatsu, C.H.; Benday, N.S.; Davis, C.M. [Department of Chemistry, College of William and Mary, Williamsburg, VA 23187 (United States); Hays, K.; Wagner, M.J. [Department of Chemistry, George Washington University, Washington, D.C. 20052 (United States)
2017-07-15
Highlights: • CuCl{sub 2}·2D{sub 2}O is examined magnetically and compared with CuCl{sub 2}·2H{sub 2}O. • Slightly lower magnetic characteristic temperatures occur for deuterated dihydrate. • The new compound CuBr{sub 2}·6H{sub 2}O is examined magnetically. • Unexpected relationships appears between magnetic behaviors of CuBr{sub 2}·6H{sub 2}O and CuBr{sub 2}. • Two alternative monoclinic unit cells can account for diffraction data on CuBr{sub 2}·6H{sub 2}O. - Abstract: The magnetic properties of little examined CuCl{sub 2}·2D{sub 2}O are studied and compared with those of CuCl{sub 2}·2H{sub 2}O. New CuBr{sub 2}·6H{sub 2}O is also examined. Susceptibility maxima appear for chlorides at 5.35 and 5.50 K, in the above order, with estimated antiferromagnetic ordering at 4.15 and 4.25 K. Curie-Weiss fits yield g of 2.210 and 2.205, and Weiss θ of −6.0 and −4.7 K, respectively, in χ{sub M} = C/(T − θ). One-dimensional Heisenberg model fits to susceptibilities, including interchain exchange in a mean-field approximation, are performed. Interchain exchange is significant but much weaker than intrachain. The bromide hexahydrate strongly differs magnetically from any chloride hydrate, but exhibits notable similarities and differences compared to previously studied CuBr{sub 2}. A broad susceptibility maximum occurs near 218 K, only 4% lower than for CuBr{sub 2}, but with almost twice the magnitude. Powder X-ray diffraction data for CuBr{sub 2}·6H{sub 2}O may be best accounted for by a monoclinic unit cell that is metrically orthorhombic. The volume per formula unit is consistent with trends in metal ionic radii. However, an alternative monoclinic cell with 5% smaller volume more readily rationalizes the magnetism.
International Nuclear Information System (INIS)
Ning, Pengge; Xu, Weifeng; Cao, Hongbin; Xu, Hongbin
2016-01-01
Highlights: • The solubility of Na_2MoO_4·2H_2O and Na_2WO_4·2H_2O in Na_2MoO_4–Na_2WO_4–Na_2SO_4–H_2O were performed. • The solubility of sodium tungstate dihydrate in Na_2WO_4–Na_2SO_4–H_2O was determined. • The new model was established via regressing the published and the determined data. • The Pitzer parameter and the solubility product constant of the salt in solution were calculated. • The model was used to estimate the solubility of the sodium molybdate and sodium tungstate. - Abstract: The solubility of sodium tungstate dihydrate and sodium molybdate dihydrate in the (Na_2MoO_4 + Na_2WO_4 + Na_2SO_4 + H_2O) system was studied using experimental and calculated methods. The osmotic coefficient of sodium tungstate was fitted to calculate the thermodynamics parameters of (Na_2WO_4 + H_2O) system. The solubility of sodium tungstate dihydrate was determined using the dynamic method in Na_2WO_4–Na_2SO_4–H_2O to establish the new model which can provide an estimate the solubility of sodium tungstate dihydrate in various conditions, combined with the data published, the solubility of sodium tungstate dihydrate and the sodium molybdate dihydrate in quaternary system of (Na_2MoO_4 + Na_2WO_4 + Na_2SO_4 + H_2O) was estimated using the parameters of the two ternary systems of (Na_2WO_4 + Na_2SO_4 + H_2O) and (Na_2MoO_4 + Na_2SO_4 + H_2O). The results show that the AARD is always small and the calculated value is basically consistent with the experimental values for the system studied.
International Nuclear Information System (INIS)
Rehse, Steven J.; Fairbank, William M.; Lee, Siu Au
2001-01-01
The hyperfine structure of the 4d 2 D 3/2,5/2 levels of 69,71 Ga is determined. The 4p 2 P 3/2 ->4d 2 D 3/2 (294.50-nm) and 4p 2 P 3/2 ->4d 2 D 5/2 (294.45-nm) transitions are studied by laser-induced fluorescence in an atomic Ga beam. The hyperfine A constant measured for the 4d 2 D 5/2 level is 77.3±0.9 MHz for 69 Ga and 97.9± 0.7 MHz for 71 Ga (3σ errors). The A constant measured for the 4d 2 D 3/2 level is -36.3±2.2 MHz for 69 Ga and -46.2±3.8 MHz for 71 Ga. These measurements correct sign errors in the previous determination of these constants. For 69 Ga the hyperfine B constants measured for the 4d 2 D 5/2 and the 4d 2 D 3/2 levels are 5.3±4.1 MHz and 4.6±4.2 MHz, respectively. The isotope shift is determined to be 114±8 MHz for the 4p 2 P 3/2 ->4d 2 D 3/2 transition and 115±7 MHz for the 4p 2 P 3/2 ->4d 2 D 5/2 transition. The lines of 71 Ga are shifted to the blue. This is in agreement with previous measurement. [copyright] 2001 Optical Society of America
2-[(1-Benzamido-2-methoxy-2-oxoethylamino]benzoic Acid
Directory of Open Access Journals (Sweden)
Alami Anouar
2013-01-01
Full Text Available The carboxylic α,α-diaminoester 2-[(1-benzamido-2-methoxy-2-oxoethyl amino]benzoic acid is obtained by N-alkylation of methyl α-azido glycinate N-benzoylated with 2-aminobenzoic acid.
Nitrogen heteroaromatic cations by [2+2+2] cycloaddition
Czech Academy of Sciences Publication Activity Database
Čížková, Martina; Kolivoška, Viliam; Císařová, I.; Šaman, David; Pospíšil, Lubomír; Teplý, Filip
2011-01-01
Roč. 9, č. 2 (2011), s. 450-462 ISSN 1477-0520 R&D Projects: GA ČR GA203/09/1614; GA ČR GA203/09/0705; GA MŠk OC 140 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z40400503 Keywords : modular synthesis * N-heteroaromatic cation * [2+2+2] cycloaddition Subject RIV: CC - Organic Chemistry Impact factor: 3.696, year: 2011
Construction of Δm2--sin2 2θ plots
International Nuclear Information System (INIS)
Snyder, R.
1991-01-01
In the two-flavor approximation, the probability for a neutrino to oscillate from one flavor to the other is given by Ρ νa → νb = sin 2 2θ sin 2 (1.27 Δm 2 L/E ν ) where θ is the mixing angle, Δm 2 = |m νa 2 - m νb 2 | is measured in (eV/c 2 ) 2 , L, the distance from the source, is measured in km, and E, the beam energy, is measured in GeV. If either Δm 2 or sin 2 2Θ is zero, there is no oscillation. They might also have small, non-zero values, causing the oscillations to be so small as to be unobservable in a particular experiment. They may also have values which allow us to determine the probability of oscillation, but so far no compelling evidence for oscillation exists. The universal method of portraying what region of parameter space is explored by a neutrino oscillation experiment is to mark off an area on a Δm 2 vs. sin 2 2θ plot. Typically, a line is graphed, with the claim that if the experiment finds not evidence of oscillation, one can, for example, be 90% certain that Δm 2 and sin 2 2θ lie within the region below and to the left of the line. Since these plots are so widely used, it is useful to understand the process by which they are created
Directory of Open Access Journals (Sweden)
2009-03-01
Full Text Available The title compound, [Ir(C12H8NOCl2(C12H9NO]·CH2Cl2, which was obtained from the reaction of iridium(III chloride trihydrate and 2-benzoylpyridine, contains an IrIII atom coordinated by two N, one O, one C and two Cl atoms in trans positions, forming a distorted octahedral environment. The solvent molecule CH2Cl2 is disordered over two positions with an occupancy of 0.8:0.2.
Energy Technology Data Exchange (ETDEWEB)
Thomas, R. [Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Hall de Recherche de Pierrelatte, AREVA NC, BP 16, 26701 Pierrelatte (France); Rivenet, M., E-mail: murielle.rivenet@ensc-lille.fr [Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Berrier, E. [Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Waele, I. de [Université de Lille, CNRS, UMR 8516 – LASIR - Laboratoire de Spectrochimie Infrarouge et Raman, F-59000 Lille (France); Arab, M.; Amaraggi, D.; Morel, B. [Hall de Recherche de Pierrelatte, AREVA NC, BP 16, 26701 Pierrelatte (France); Abraham, F. [Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille (France)
2017-01-15
The thermal decomposition of uranyl peroxide tetrahydrate, (UO{sub 2})O{sub 2}(H{sub 2}O){sub 2}.2H{sub 2}O, was studied by combining high temperature powder X-ray diffraction, scanning electron microscopy, thermal analyses and spectroscopic techniques (Raman, IR and {sup 1}H NMR). In situ analyses reveal that intermediates and final uranium oxides obtained upon heating are different from that obtained after cooling at room temperature and that the uranyl precursor used to synthesize (UO{sub 2})O{sub 2}(H{sub 2}O){sub 2}·2H{sub 2}O, sulfate or nitrate, has a strong influence on the peroxide thermal behavior and morphology. The decomposition of (UO{sub 2})O{sub 2}(H{sub 2}O){sub 2}·2H{sub 2}O ex sulfate is pseudomorphic and leads to needle-like shaped particles of metastudtite, (UO{sub 2})O{sub 2}(H{sub 2}O){sub 2}, and UO{sub 3-x}(OH){sub 2x}·zH{sub 2}O, an amorphous phase found in air in the following of (UO{sub 2})O{sub 2}(H{sub 2}O){sub 2} dehydration. (UO{sub 2})O{sub 2}(H{sub 2}O){sub 2}·2H{sub 2}O and the compounds resulting from its thermal decomposition are very reactive towards hydrofluorination as long as their needle-like morphology is kept.
ZrCu2P2 and HfCu2P2 phosphides and their crystal structure
International Nuclear Information System (INIS)
Lomnitskaya, Ya.F.
1986-01-01
Isostructural ZrCu 2 P 2 and HfCu 2 P 2 compounds are prepared for the first time. X-ray diffraction analysis (of powder, DRON-2.0 diffractometer, FeKsub(α) radiation) was used to study crystal structure of HfCu 2 P 2 phosphide belonging to the CaAl 2 Si 2 structural type (sp. group P anti 3 m 1, R=0.095). Lattice parameters the compounds are as follows: for ZrCu 2 P 2 a=0.3810(1), c=0.6184(5); for HfCu 2 P 2 a=0.3799(1), c=0.6160(2) (nm). Atomic parameters in the HfCu 2 P 2 structure and interatomic distances are determined
Goff, George S; Brodnax, Lia F; Cisneros, Michael R; Peper, Shane M; Field, Stephanie E; Scott, Brian L; Runde, Wolfgang H
2008-03-17
In alkaline carbonate solutions, hydrogen peroxide can selectively replace one of the carbonate ligands in UO2(CO3)3(4-) to form the ternary mixed U(VI) peroxo-carbonato species UO2(O2)(CO3)2(4-). Orange rectangular plates of K4[UO2(CO3)2(O2)].H2O were isolated and characterized by single crystal X-ray diffraction studies. Crystallographic data: monoclinic, space group P2(1)/ n, a = 6.9670(14) A, b = 9.2158(10) A, c = 18.052(4) A, Z = 4. Spectrophotometric titrations with H 2O 2 were performed in 0.5 M K 2CO 3, with UO2(O2)(CO3)2(4-) concentrations ranging from 0.1 to 0.55 mM. The molar absorptivities (M(-1) cm(-1)) for UO2(CO3)3(4-) and UO2(O2)(CO3)2(4-) were determined to be 23.3 +/- 0.3 at 448.5 nm and 1022.7 +/- 19.0 at 347.5 nm, respectively. Stoichiometric analyses coupled with spectroscopic comparisons between solution and solid state indicate that the stable solution species is UO2(O2)(CO3)2(4-), which has an apparent formation constant of log K' = 4.70 +/- 0.02 relative to the tris-carbonato complex.
VUV photoionization cross sections of HO2, H2O2, and H2CO.
Dodson, Leah G; Shen, Linhan; Savee, John D; Eddingsaas, Nathan C; Welz, Oliver; Taatjes, Craig A; Osborn, David L; Sander, Stanley P; Okumura, Mitchio
2015-02-26
The absolute vacuum ultraviolet (VUV) photoionization spectra of the hydroperoxyl radical (HO2), hydrogen peroxide (H2O2), and formaldehyde (H2CO) have been measured from their first ionization thresholds to 12.008 eV. HO2, H2O2, and H2CO were generated from the oxidation of methanol initiated by pulsed-laser-photolysis of Cl2 in a low-pressure slow flow reactor. Reactants, intermediates, and products were detected by time-resolved multiplexed synchrotron photoionization mass spectrometry. Absolute concentrations were obtained from the time-dependent photoion signals by modeling the kinetics of the methanol oxidation chemistry. Photoionization cross sections were determined at several photon energies relative to the cross section of methanol, which was in turn determined relative to that of propene. These measurements were used to place relative photoionization spectra of HO2, H2O2, and H2CO on an absolute scale, resulting in absolute photoionization spectra.
Flow microreactor synthesis of 2,2-disubstituted oxetanes via 2-phenyloxetan-2-yl lithium
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Degennaro Leonardo
2016-01-01
Full Text Available A mild and sustainable synthesis of 2,2-disubstituted oxetanes has been achieved through the use of a flow microreactor system. By controlling the residence time a highly unstable intermediate such as 2-phenyloxetan-2-yl lithium can be generated and trapped with various electrophiles affording in moderate to good yields 2-substituted-2-phenyloxetanes at higher temperatures with respect to macrobatch-mode where –78 °C is required.
Deelman, Berth-Jan; Stevels, Willem M.; Teuben, Jan H.; Lakin, Miles T.; Spek, Anthony L.
1994-01-01
Pyridine is metalated selectively at the 2-position by (Cp*2YH)2 to yield Cp*2Y(2-pyridyl) (1). Compound 1 reacts with H2 to give the hydride addition product Cp*2Y(NC5H6) (2). With THF and pyridine the adducts Cp*2Y(η2-2-pyridyl)(THF) (3) and Cp*2Y(η1-2-pyridyl)(py) (4) are formed. The pyridine
Magnetic properties of the UMn2-UFe2 and UMn2-UCO2 system alloys
International Nuclear Information System (INIS)
Meskhishvili, A.I.; Pletyushkin, V.A.; Slovyanskikh, V.K.; Chechernikov, V.I.; Shavishvili, T.M.
1978-01-01
The magnetic properties of compounds UMn 2 and UCo 2 , and solid solutions UMn 2 -UFe 2 and UMn 2 -UCo 2 have been examined. It has been established, that in substituting iron ions with manganese ions, the temperature of the ferromagnetic transformation of UFe 2 decreases, and within the region of 50 at.% UFe 2 the ferromagnetic ordering disappears. The Curie-Weiss law holds within a limited temperature range. In the solid solutions of two paramagnets UMn 2 and UCo 2 , which are independent of temperature, at a concentration of 45 to 50 at.% UCo 2 , the magnetic susceptibility and its dependence on temperature attain their maximum values. The results obtained are connected with the collectivization of d-, f-, and s-electrons of an alloy
2-minute Gridded Global Relief Data (ETOPO2) v2
National Oceanic and Atmospheric Administration, Department of Commerce — Two-minute gridded global relief for both ocean and land areas are available in the ETOPO2v2 (2006) database. ETOPO2v2 replaced ETOPO2 (2001). The historic 2-minute...
Convenient synthesis of 2,2-Dimethyl-3,4-dihydro-2 H-pyrano[2,3- b]quinolines
Digital Repository Service at National Institute of Oceanography (India)
Parsekar, S.B.; Amonkar, C.P.; Parameswaran, P.S.; Tilve, S.G.
A convenient general synthesis of 2,2-dimethyl-3,4-dihydro-2H-pyrano[2,3-b]quinolines using the Wittig reaction is described. The o-nitrobenzaldehydes (1a-d) on reaction with phosphorane 2 provided (E)-ethyl-a-(2,2-dimethylprop-2-ene)-2...
International Nuclear Information System (INIS)
Hsienhau Wang; Casalnuovo, A.L.; Johnson, B.J.; Mueting, A.M.; Pignolet, L.H.
1988-01-01
Two new cationic polyhydrido cluster complexes of iridium have been synthesized and characterized by single-crystal x-ray diffraction and by ir and 1 H and 31 P NMR spectroscopy (Ir 3 (dppp) 3 (H) 7 (CO)) 2+ (2) and (Ir3 (PN) 3 (H) 7)2+ (5), where dppp = 1,3-bis(diphenylphosphino)propane and PN = 1-(2-pyridyl)-2-(diphenylphosphino)ethane, were synthesized by the reaction of CO with (Ir 3 (dppp) 3 (H) 7 ) 2+ (1) in CH 2 Cl 2 solution and H 2 with (Ir(PN)(COD)) + (4) in CH 3 OH solution, respectively. Crystal structures for both compounds is reported. The hydride positions were not located in the crystal structure analyses but were deduced from structural and 1 H NMR data. The molecular structure of 2 consists of a bilateral triangle of three iridium atoms with a carbonyl at the vertex and a chelating dppp ligand on each iridium atom. 1 H NMR data with use of acetone-d 6 as solvent showed that 2 possesses four doubly bridging hydrides and three terminal hydrides, yielding C 1 symmetry. The molecular structure of 5 consists of an approximately equilateral triangle of three iridium atoms (average Ir-Ir distance 2.746 (1) angstrom) with one PN ligand chelated to each iridium atom. 1 H NMR analysis, with use of CD 2 Cl 2 as solvent, showed that 5 has one triply bridging hydride and six terminal hydrides, giving C 3 symmetry. (Ir 3 (dppp) 3 (H) 7 (CH 3 C 6 H 4 NC)) 2+ (3) a complex structurally analogous to 2, was synthesized from 1 and p-tolyl isocyanide in CH 2 Cl 2 solution and characterized by ir and 1 H and 31 P NMR spectroscopy. 44 refs., 3 figs., 3 tabs
Comparative toxicity of VO3-, CrO42-, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, and Cd2+ to lettuce seedlings
International Nuclear Information System (INIS)
Berry, W.L.
1978-01-01
Lettuce seeds imbibed, germinated, and grown in a 0.1-strength modified Hoagland culture solution were subjected to a series of increasing concentrations of individual heavy metals up to and exceeding lethal levels. After an exposure of 5 days, seedlings were harvested, examined, and measured to determine toxic effects. A log--log plot of root length (yield) vs. heavy metal concentration was made for each metal to produce a dose response curve. The curves showed a growth plateau at low concentrations of the respective metals which was equivalent to the growth of the control. All metals inhibited root growth and caused lethal toxicity in the sub- and low-milliequivalent range. When concentrations of the tested metals exceeded their thresholds of acute toxicity, root growth was inhibited. In the zone of inhibition, between the acute toxic threshold and complete inhibition, the log--log dose response curves were approximately linear or were a series of linear steps. The threshold toxicity and the response slope were characteristic for each metal. Seedling lettuce showed a monophasic response to VO 3 - , Cu 2+ , and Zn 2+ ; a biphasic response to CrO 4 2 -, Mn 2+ , Ni 2+ , and Cd 2+ ; and a quadraphasic response to Co 2+ . The acute toxicity threshold on an equivalent basis increased according to the following sequence: Cd 2+ much less than VO 3 - 2+ 2+ 2+ 4 2- 2+ much less than Mn 2+ . On this basis, Cd 2+ is the most toxic of the trace elements tested
Structure of human ubiquitin-conjugating enzyme E2 G2 (UBE2G2/UBC7)
International Nuclear Information System (INIS)
Arai, Ryoichi; Yoshikawa, Seiko; Murayama, Kazutaka; Imai, Yuzuru; Takahashi, Ryosuke; Shirouzu, Mikako; Yokoyama, Shigeyuki
2006-01-01
The crystal structure of human UBE2G2/UBC7 was solved at 2.56 Å resolution. The superimposition of UBE2G2 on UbcH7 in a c-Cbl–UbcH7–ZAP70 ternary complex suggested that the two loop regions of UBE2G2 interact with the RING domain in a similar way as UbcH7. The human ubiquitin-conjugating enzyme E2 G2 (UBE2G2/UBC7) is involved in protein degradation, including a process known as endoplasmic reticulum-associated degradation (ERAD). The crystal structure of human UBE2G2/UBC7 was solved at 2.56 Å resolution. The UBE2G2 structure comprises a single domain consisting of an antiparallel β-sheet with four strands, five α-helices and two 3 10 -helices. Structural comparison of human UBE2G2 with yeast Ubc7 indicated that the overall structures are similar except for the long loop region and the C-terminal helix. Superimposition of UBE2G2 on UbcH7 in a c-Cbl–UbcH7–ZAP70 ternary complex suggested that the two loop regions of UBE2G2 interact with the RING domain in a similar way to UbcH7. In addition, the extra loop region of UBE2G2 may interact with the RING domain or its neighbouring region and may be involved in the binding specificity and stability
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Thierry Roisnel
2012-07-01
Full Text Available The vanadium oxide arsenate with formula K2V2O2(AsO42, dipotassium divanadium(IV dioxide diarsenate, has been synthesized by solid-state reaction in an evacuated silica ampoule. Its structure is isotypic with K2V2O2(PO42. The framework is built up from corner-sharing VO6 octahedra and AsO4 tetrahedra, creating an infinite [VAsO8]∞ chain running along the a- and c-axis directions. The K+ cations are located in hexagonal tunnels, which are delimited by the connection of the [VAsO8]∞ chains.
International Nuclear Information System (INIS)
Saparov, Bayrammurad; Saito, Maia; Bobev, Svilen
2011-01-01
Presented are the details of the syntheses, crystal and electronic structures of a new family of Zintl phases Na 2 ACdSb 2 and K 2 ACdSb 2 (A=Ca, Sr, Ba, Eu, Yb), as well as the solid solutions Sr 2-x A x CdSb 2 , Ba 2-x A x CdSb 2 and Eu 2-x Yb x CdSb 2 . The structures of Na 2 ACdSb 2 and K 2 ACdSb 2 (A=Ca, Sr, Ba, Eu, Yb) were determined to be of a new type with the non-centrosymmetric space group Pmc2 1 (no. 26), Pearson symbol oP12, with lattice parameters a=4.684(1)-4.788(1) A; b=9.099(3)-9.117(2) A; c=7.837(1)-8.057(2) A for the Na 2 ACdSb 2 series, and a=4.6637(9)-5.0368(8) A; b=9.100(2)-9.8183(15) A; and c=7.7954(15)-8.4924(13) A for K 2 ACdSb 2 , respectively. The solid solutions Sr 2-x A x CdSb 2 , Ba 2-x A x CdSb 2 and Eu 2-x Yb x CdSb 2 (x∼1) are isostructural and isoelectronic to the recently reported Yb 2 CdSb 2 (space group Cmc2 1 (no. 36), Pearson symbol cP20). All discussed structures are based upon CdSb 2 4- polyanionic layers, similar to the ones observed in Yb 2 CdSb 2 , with various alkali- and/or alkaline-earth cations coordinated to them. Magnetic susceptibility and Seebeck coefficient measurements on selected Eu 2-x Yb x CdSb 2 samples, taken at low temperatures up to 300 K, are also reported. -- Graphical abstract: The quaternary Zintl phases Na 2 ACdSb 2 and K 2 ACdSb 2 (A=Ca, Sr, Ba, Eu, Yb) with novel layered structures have been synthesized for the first time and structurally characterized by single-crystal X-ray diffraction. Reported as well are the results from crystallographic and property studies of the closely related solid solutions Sr 2-x A x CdSb 2 , Ba 2-x A x CdSb 2 (x∼1), and Eu 2-x Yb x CdSb 2 (1 2 ACdSb 2 and K 2 ACdSb 2 (A=Ca, Sr, Ba, Eu, Yb) are new quaternary Zintl phases. → Sr 2-x A x CdSb 2 , Ba 2-x A x CdSb 2 (x∼1), and Eu 2-x Yb x CdSb 2 (1 4 tetrahedra. → Eu 2-x Yb x CdSb 2 (1< x<2) exhibit high Seebeck coefficient (217 μV/K at RT).
Comparative study of pinning and creep in Tl2Ba2CaCu2O8 and Bi2Sr2CaCu2O8 single crystals
International Nuclear Information System (INIS)
Oussena, M.; Porter, S.; Volkozub, A.V.; de Groot, P.A.J.; Lanchester, P.C.; Ogborne, D.; Weller, M.T.; Balakrishnan, G.; Paul, D.M.
1993-01-01
We have compared the pinning and creep in two identically shaped single crystals, Tl 2 Ba 2 CaCu 2 O 8 (Tl 2:2:1:2) and Bi 2 Sr 2 CaCu 2 O 8 (Bi 2:2:1:2) using magnetometry. The critical current density, J c , deduced from the M-H hysteresis loops is found to be the highest in Bi 2:2:1:2 at low temperatures (T c , in this temperature range, is similar for both crystals. At higher temperatures, J c is found to decrease more rapidly with magnetic field in Bi 2:2:1:2 than in Tl 2:2:1:2. The critical current also decreases more quickly with temperature in Bi 2:2:1:2 leading to a vanishing J c at temperatures lower than in the case of Tl 2:2:1:2. I-V characteristic curves have been obtained from measurements of magnetic-sweep-rate dependencies of the hysteresis loops. We have found that the characteristic temperature at which flux motion becomes important is significantly higher in Tl 2:2:1:2 than in Bi 2:2:1:2
Lanthanide complexes of 2-aminoacetophenone and 2-acetylaminoacetophenone 2-thenoylhydrazone
International Nuclear Information System (INIS)
Singh, Praveen K.; Singh, B.
1998-01-01
The reaction of lanthanide chlorides with 2-aminoacetophenone-2-thenoyl- hydrazone and 2-acetylaminoacetophenone-2-thenoylhydrazone yield complexes of the type [Ln(aath) 2 Cl 2 (H 2 )O]Cl and [Ln(acaath) 2 Cl 2 ]Cl. These complexes have been characterized by molar conductance, magnetic susceptibility, TGA, DTA and various spectroscopic techniques such as mass, IR, NMR, UV - visible and emission spectra. Mass spectral data indicate the aath complexes to be monomeric. Thermal stability of the complexes and presence of one water molecule in aath complex is indicated by TGA and DTA studies. Electronic spectra of Pr(III) and Nd(III) complexes show the coordination number to be nine and eight around the metal ions in the aath and acaath complexes, respectively. This has also been inferred from the spectral features of the hypersensitive transition in the Nd(III) complexes. The lowering in coordination number from aath to acaath complexes may be attributed to increase in chelate ring size and/or steric/inductive effect of methyl group. Emission spectral studies of the [Eu(aath) 2 Cl 2 (H 2 O)]Cl and [Eu(acaath) 2 Cl 2 ]Cl suggest tricapped trigonal prismatic (D 3h ) and square antiprismatic (D 4d ) geometry, respectively. (author)
International Nuclear Information System (INIS)
Larionov, S.V.; Kirichenko, V.N.; Platonov, V.E.; Maksimov, A.M.; Rodionov, P.P.; Fadeeva, V.P.; Oglezneva, I.M.; Lisojvan, V.I.; AN SSSR, Novosibirsk
1992-01-01
Zn 2+ , Cd 2+ , Hg 2+ coordination compounds with 2, 3, 5 -trifluoro- 4,6 bis(trifluoromethyl)trhiophenol (MHal) and heptafluoro-2-thionophthal (HT) of ZnHal 2 (CH 3 OH), CdHal 2 , HgHal 2 and MT 2 (M=Zn, Cd, Hg) composition, are obtained. Complexes are studied using thermal and X-ray phase analysis, vapour phase osmometry and IR spectroscopy, ZnHal 2 (CH 3 OH), CdHal 2 , ZnT 2 , HgHfl 2 , HgT 2 compounds in acetone solutions are in monomeric state, while in CdT 2 commeric particles. Frequencies of mostly valent vibrations of Cd-S bond are observed at 241 (CdHal 2 ), 225 (CdT 2 )
Intramolecular ketenimine-ketenimine [2 + 2] and [4 + 2] cycloadditions.
Alajarín, Mateo; Bonillo, Baltasar; Sanchez-Andrada, Pilar; Vidal, Angel; Bautista, Delia
2007-07-20
Bis(ketenimines), in which the two heterocumulenic functions are placed in close proximity on a carbon skeleton to allow their mutual interaction, show a rich and not easily predictable chemistry. Intramolecular [2 + 2] or [4 + 2] cycloadditions are, respectively, observed when both ketenimine functions are supported on either ortho-benzylic or 2,2'-biphenylenic scaffolds. In addition, nitrogen-to-carbon [1,3] and [1,5] shifts of arylmethyl groups in N-arylmethyl-C,C-diphenyl ketenimines are also disclosed.
Duguid, J G; Bloomfield, V A; Benevides, J M; Thomas, G J
1995-12-01
Differential scanning calorimetry, laser Raman spectroscopy, optical densitometry, and pH potentiometry have been used to investigate DNA melting profiles in the presence of the chloride salts of Ba2+, Sr2+, Mg2+, Ca2+, Mn2+, Co2+, Ni2+, and Cd2+. Metal-DNA interactions have been observed for the molar ratio [M2+]/[PO2-] = 0.6 in aqueous solutions containing 5% by weight of 160 bp mononucleosomal calf thymus DNA. All of the alkaline earth metals, plus Mn2+, elevate the melting temperature of DNA (Tm > 75.5 degrees C), whereas the transition metals Co2+, Ni2+, and Cd2+ lower Tm. Calorimetric (delta Hcal) and van't Hoff (delta HVH) enthalpies of melting range from 6.2-8.7 kcal/mol bp and 75.6-188.6 kcal/mol cooperative unit, respectively, and entropies from 17.5 to 24.7 cal/K mol bp. The average number of base pairs in a cooperative melting unit () varied from 11.3 to 28.1. No dichotomy was observed between alkaline earth and transition DNA-metal complexes for any of the thermodynamic parameters other than their effects on Tm. These results complement Raman difference spectra, which reveal decreases in backbone order, base unstacking, distortion of glycosyl torsion angles, and rupture of hydrogen bonds, which occur after thermal denaturation. Raman difference spectroscopy shows that transition metals interact with the N7 atom of guanine in duplex DNA. A broader range of interaction sites with single-stranded DNA includes ionic phosphates, the N1 and N7 atoms of purines, and the N3 atom of pyrimidines. For alkaline earth metals, very little interaction was observed with duplex DNA, whereas spectra of single-stranded complexes are very similar to those of melted DNA without metal. However, difference spectra reveal some metal-specific perturbations at 1092 cm-1 (nPO2-), 1258 cm-1 (dC, dA), and 1668 cm-1 (nC==O, dNH2 dT, dG, dC). Increased spectral intensity could also be observed near 1335 cm-1 (dA, dG) for CaDNA. Optical densitometry, employed to detect DNA
Energy Technology Data Exchange (ETDEWEB)
Ivanov, V. E.; Zelenskij, V. F.; Kolendovskij, M. K.; Kolomiets, L. D.
1963-11-15
}asnit' mekhanizm i prichiny razrusheniya izdelij v protsesse propitki. Na osnove provedennykh issledovanij vydvigaetsya ryad trebovanij k tekhnologii, pri vypolnenii kotorykh mozhno poluchat' izdeliya iz grafit-karbidkremnievykh materialov metodom propitki grafitov zhidkim kremniem v vakuume pri temperature 1450 - 1600 deg. C. (author)
Directory of Open Access Journals (Sweden)
Helmut Moritz
2016-12-01
Full Text Available It has been pointed out by the great Swedish geodesist Arne Bjerhammar and others around1985 that it is possible to replace the classical method of spirit leveling for determining differences of the geopotential by a much more direct and elegant method, measuring the frequency of atomic clocks. This is impossible by classical physics and requires methods of Einstein’s General Theory of Relativity. The principle is that the geopotential can be “felt” by the “proper time” of this theory, but there remained the problem that the measuring accuracies were unthinkably high in 1985 and even later. To get a leveling accuracy of 1 cm, we must measure these frequencies to a relative accuracy of 10-18. Reaching such accuracies provided a great challenge to high-precision time observation all over the world, from USA to China. Now it seems that the required frequency accuracy is being reached. The author tries to give a short introductory review accessible to geodetic students and surveyors. It is purely didactic. : Veliki švedski geodeta Arne Bjerhammar (i neki drugi, istakao je oko 1985. godine, da je klasičnu metodu geometrijskog nivelmana za određivanje razlika geopotencijala moguće zamijeniti mnogo direktnijom i elegantnom metodom, mjerenjem frekvencije atomskih satova. Ovo nije moguće metodama klasične fizike, te zahtijeva primjenu Ajnštajnove Teorije općeg relativiteta. Princip je da se geopotencijal može “osjetiti” pomoću “pravog vremena” ove teorije, ali ostaje problem što je tačnost mjerenja bila nezamisliva u 1985. godini, pa čak i poslije. Da bi se dobila tačnost nivelanja od 1 cm, frekvencije se moraju mjeriti s relativnom tačnošću od 10-18. Dostizanje ove tačnosti bio je ogroman izazov za sve svjetske opservatorije za visokoprecizno mjerenje vremena, od SAD do Kine. Čini se da je zahtijevana tačnost ipak dostignuta. Autor nastoji dati kratak, potpuno didaktički uvod, pristupačan studentima geodezije i
Strain engineering of WS2, WSe2, and WTe2
Amin, Bin
2014-01-01
We perform first-principles calculations to investigate the structural, electronic, and vibrational properties of WS2, WSe2, and WTe2 monolayers, taking into account the strong spin orbit coupling. A transition from a direct to an indirect band gap is achieved for compressive strain of 1% for WS2, 1.5% for WSe2, and 2% for WTe 2, while the nature of the band gap remains direct in the case of tensile strain. The size of the band gap passes through a maximum under compressive strain and decreases monotonically under tensile strain. A strong spin splitting is found for the valence band in all three compounds, which is further enhanced by tensile strain. The mobility of the electrons grows along the series WS2 < WSe2 < WTe2. This journal is © the Partner Organisations 2014.
Apfel, C; Banner, D W; Bur, D; Dietz, M; Hubschwerlen, C; Locher, H; Marlin, F; Masciadri, R; Pirson, W; Stalder, H
2001-06-07
Potent, selective, and structurally new inhibitors of the Fe(II) enzyme Escherichia coli peptide deformylase (PDF) were obtained by rational optimization of the weakly binding screening hit (5-chloro-2-oxo-1,4-dihydro-2H-quinazolin-3-yl)-acetic acid hydrazide (1). Three-dimensional structural information, gathered from Ni-PDF complexed with 1, suggested the preparation of two series of related hydroxamic acid analogues, 2-(2-oxo-1,4-dihydro-2H-quinazolin-3-yl)-N-hydroxy-acetamides (A) and 2-(2,2-dioxo-1,4-dihydro-2H-2lambda(6)-benzo[1,2,6]thiadiazin-3-yl)-N-hydroxy-acetamides (B), among which potent PDF inhibitors (37, 42, and 48) were identified. Moreover, two selected compounds, one from each series, 36 and 41, showed good selectivity for PDF over several endoproteases including matrix metalloproteases. However, these compounds showed only weak antibacterial activity.
Crystal structures of ZnCl2·2.5H2O, ZnCl2·3H2O and ZnCl2·4.5H2O
Directory of Open Access Journals (Sweden)
Erik Hennings
2014-12-01
Full Text Available The formation of different complexes in aqueous solutions is an important step in understanding the behavior of zinc chloride in water. The structure of concentrated ZnCl2 solutions is governed by coordination competition of Cl− and H2O around Zn2+. According to the solid–liquid phase diagram, the title compounds were crystallized below room temperature. The structure of ZnCl2·2.5H2O contains Zn2+ both in a tetrahedral coordination with Cl− and in an octahedral environment defined by five water molecules and one Cl− shared with the [ZnCl4]2− unit. Thus, these two different types of Zn2+ cations form isolated units with composition [Zn2Cl4(H2O5] (pentaaqua-μ-chlorido-trichloridodizinc. The trihydrate {hexaaquazinc tetrachloridozinc, [Zn(H2O6][ZnCl4]}, consists of three different Zn2+ cations, one of which is tetrahedrally coordinated by four Cl− anions. The two other Zn2+ cations are each located on an inversion centre and are octahedrally surrounded by water molecules. The [ZnCl4] tetrahedra and [Zn(H2O6] octahedra are arranged in alternating rows parallel to [001]. The structure of the 4.5-hydrate {hexaaquazinc tetrachloridozinc trihydrate, [Zn(H2O6][ZnCl4]·3H2O}, consists of isolated octahedral [Zn(H2O6] and tetrahedral [ZnCl4] units, as well as additional lattice water molecules. O—H...O hydrogen bonds between the water molecules as donor and ZnCl4 tetrahedra and water molecules as acceptor groups leads to the formation of a three-dimensional network in each of the three structures.
Energy Technology Data Exchange (ETDEWEB)
Rudolph, Daniel; Schleid, Thomas [Stuttgart Univ. (Germany). Inst. fuer Anorganische Chemie
2017-07-01
The syntheses and crystal structures of the two isotypic europium(II) oxide halides Eu{sub 2}OBr{sub 2} and Eu{sub 2}OI{sub 2} are reported. They crystallize orthorhombically in the space group Ibam (Z=4; Eu{sub 2}OBr{sub 2}: a=709.86(5), b=1200.34(9), c=628.71(4) pm; Eu{sub 2}OI{sub 2}: a=739.78(5), b=1295.13(9), c=644.82(4) pm). The unit cell parameters presented here, and thus the interatomic distances of Eu{sub 2}OI{sub 2}, are significantly smaller than the ones reported in the literature, which is explained by the substitution of europium with larger barium cations due to the synthesis route described in the early study. Central building blocks of both crystal structures are trans-edge-connected [OEu{sub 4}]{sup 6+} tetrahedra forming straight {sup 1}{sub ∞}{[OEu"e_4_/_2]"2"+} chains running parallel to the [001] direction. Bundled like a hexagonal rod packing, their interaction is achieved by Br{sup -} or I{sup -} anions for charge compensation.
International Nuclear Information System (INIS)
Ramaswamy, Padmini; Mandal, Sukhendu; Natarajan, Srinivasan
2009-01-01
A novel manganese phosphite-oxalate, [C 2 N 2 H 10 ][Mn 2 II (OH 2 ) 2 (HPO 3 ) 2 (C 2 O 4 )] has been hydothermally synthesized and its structure determined by single-crystal X-ray diffraction. The structure consists of neutral manganese phosphite layers, [Mn(HPO 3 )] ∞ , formed by MnO 6 octahedra and HPO 3 units, cross-linked by the oxalate moieties. The organic cations occupy the middle of the 8-membered one-dimensional channels. Magnetic studies indicate weak antiferromagnetic interactions between the Mn 2+ ions. - Abstract: A new antiferromagnetic three-dimensional inorganic-organic hybrid compound, [C 2 N 2 H 10 ][Mn 2 II (OH 2 ) 2 (HPO 3 ) 2 (C 2 O 4 )] has been prepared hydrothermally. The compound has neutral manganese layers pillared by oxalate units. The neutral manganese layers are shown here. Display Omitted
Naveen Kumar Reddy, B; Sailaja, S; Thyagarajan, K; Jho, Young Dahl; Sudhakar Reddy, B
2018-05-01
Four series of borosilicate glasses modified by alkali oxides and doped with Tb 3+ and Sm 3+ ions were prepared using the conventional melt quenching technique, with the chemical composition 74.5B 2 O 3 + 10SiO 2 + 5MgO + R + 0.5(Tb 2 O 3 /Sm 2 O 3 ) [where R = 10(Li 2 O /Na 2 O/K 2 O) for series A and C, and R = 5(Li 2 O + Na 2 O/Li 2 O + K 2 O/K 2 O + Na 2 O) for series B and D]. The X-ray diffraction (XRD) patterns of all the prepared glasses indicate their amorphous nature. The spectroscopic properties of the prepared glasses were studied by optical absorption analysis, photoluminescence excitation (PLE) and photoluminescence (PL) analysis. A green emission corresponding to the 5 D 4 → 7 F 5 (543 nm) transition of the Tb 3+ ions was registered under excitation at 379 nm for series A and B glasses. The emission spectra of the Sm 3+ ions with the series C and D glasses showed strong reddish-orange emission at 600 nm ( 4 G 5/2 → 6 H 7/2 ) with an excitation wavelength λ exci = 404 nm ( 6 H 5/2 → 4 F 7/2 ). Furthermore, the change in the luminescence intensity with the addition of an alkali oxide and combinations of these alkali oxides to borosilicate glasses doped with Tb 3+ and Sm 3+ ions was studied to optimize the potential alkali-oxide-modified borosilicate glass. Copyright © 2017 John Wiley & Sons, Ltd.
International Nuclear Information System (INIS)
Fong, M.T.; Leaffer, M.A.
1986-01-01
We have prepared the 14 C-labeled analogs of NSC 261036, 1-(2,3-dihydroxypropyl)-2-nitro-1H-imidazole-2- 14 C, and NSC 301467, N-(2-hydroxyethyl)-2-(2-nitro-1H-imidazol-1-yl-2- 14 C) acetamide, for pharmacological, drug distribution, and mechanisms of action studies. The latter is an analog designed for lower toxicity and improved properties. The former is a metabolite of, and appears to be less toxic than, misonidazole. (author)
Tris[2-(2H-indazol-2-ylethyl]amine
Directory of Open Access Journals (Sweden)
Saúl Ovalle
2012-06-01
Full Text Available The title tertiary amine, C27H27N7, a potential tripodal ligand for coordination chemistry, crystallizes with the central N atom located on a threefold axis of a trigonal cell. The gauche conformation of the N(amime—CH2—CH2—N(indazole chain [torsion angle = −64.2 (2°] places the pendant 2H-indazole heterocycles surrounding the symmetry axis, affording a claw-like shaped molecule. Two symmetry-related indazole planes in the molecule make an acute angle of 60.39 (4°. The lone pair of the tertiary N atom is located inside the cavity, and should thus be inactive (as a ligand. In the crystal, neither significant π–π nor C—H...π interactions between molecules are found.
Jin, Youzhi; McFie, Pamela J.; Banman, Shanna L.; Brandt, Curtis; Stone, Scot J.
2014-01-01
Acyl CoA:1,2-diacylglycerol acyltransferase (DGAT)-2 is an integral membrane protein that catalyzes triacylglycerol (TG) synthesis using diacylglycerol and fatty acyl CoA as substrates. DGAT2 resides in the endoplasmic reticulum (ER), but when cells are incubated with fatty acids, DGAT2 interacts with lipid droplets presumably to catalyze localized TG synthesis for lipid droplet expansion. Previous studies have shown that DGAT2 interacts with proteins that synthesize its fatty acyl CoA substrates. In this study, we provide additional evidence that DGAT2 is present in a protein complex. Using a chemical cross-linker, disuccinimidyl suberate (DSS), we demonstrated that DGAT2 formed a dimer and was also part of a protein complex of ∼650 kDa, both in membranes and on lipid droplets. Using co-immunoprecipitation experiments and an in situ proximity ligation assay, we found that DGAT2 interacted with monoacylglycerol acyltransferase (MGAT)-2, an enzyme that catalyzes the synthesis of diacylglycerol. Deletion mutagenesis showed that the interaction with MGAT2 was dependent on the two transmembrane domains of DGAT2. No significant interaction of DGAT2 with lipin1, another enzyme that synthesizes diacylglycerol, could be detected. When co-expressed in cells, DGAT2 and MGAT2 co-localized in the ER and on lipid droplets. Co-expression also resulted in increased TG storage compared with expression of DGAT2 or MGAT2 alone. Incubating McArdle rat hepatoma RH7777 cells with 2-monoacylglycerol caused DGAT2 to translocate to lipid droplets. This also led to the formation of large cytosolic lipid droplets, characteristic of DGAT2, but not DGAT1, and indicated that DGAT2 can utilize monoacylglycerol-derived diacylglycerol. These findings suggest that the interaction of DGAT2 and MGAT2 serves to channel lipid substrates efficiently for TG biosynthesis. PMID:25164810
Giju, K T; Bickelhaupt, F M; Frenking, G
2000-10-16
Quantum chemical DFT calculations using the B3LYP functionals have been carried out for the electronically unsaturated 16 VE five-coordinate osmium boryl-complexes [(PH3)2(CO)ClOs-BR2] and the 18 VE six-coordinate complexes [(PH3)2(CO)2ClOs-BR2] with BR2 = BH2, BF2, B(OH)2, B(OHC=CHO), and Bcat (cat = catecholate O2C6H4). The bonding situation of the Os-BR2 bond was analyzed with the help of the NBO partitioning scheme. The Os-B bond dissociation energies of the 16 VE complexes are very high, and they do not change very much for the different boryl ligands. The 18 VE complexes have only slightly lower bond energies than the 16 VE species. The Os-B bond in both classes of compounds is provided by a covalent sigma-bond which is polarized toward osmium and by strong charge attraction. Os-->B pi-donation is not important for the Os-B binding interactions, except for the Os-BH2 complexes. The stability of the boryl complexes [Os]-BR2 comes mainly from BB pi-donation. The intraligand charge distribution of the BR2 group changes little when the Os-B bond is formed, except for BH2. The CO ligand in [(PH3)2(CO)2ClOs-BR2] which is trans to BR2 has a relatively weak bond to the osmium atom.
Preparation and luminescence properties of Eu2+-doped CaSi2O2-dN2+2/3d phosphors
International Nuclear Information System (INIS)
Gu Yunxin; Zhang Qinghong; Wang Hongzhi; Li Yaogang
2009-01-01
Eu 2+ -doped CaSi 2 O 2-d N 2+2/3d phosphors for white LED lamps were prepared by solid-state reaction, and the effects of heat-treatment conditions and the overall composition of host lattice on the optical properties have been discussed. Eu 2+ -doped CaSi 2 O 2-d N 2+2/3d displayed a single broad emission band peak at 540 nm, which could be assigned to the allowed transition of Eu 2+ from the lowest crystal field component of 4f 6 5d to 4f 7 ground-state level. The excitation band of samples, extending from UV to blue, is extremely wide, so the phosphors are suitable for white LED lamps in combination with a UV or blue LED dies. The highest PL intensity is found for the sample sintered at 1400 0 C. Moreover, the emission intensity decreases when N partially replaces O. A red shift of emission wavelength did not occur with increasing of the N content.
N-(2-Chlorophenyl-2-methylbenzamide
Directory of Open Access Journals (Sweden)
B. Thimme Gowda
2008-08-01
Full Text Available In the structure of the title compound (N2CP2MBA, C14H12ClNO, the conformations of the N—H and C=O bonds are trans to each other. Furthermore, the conformation of the N—H bond is syn to the ortho-chloro group in the aniline ring and the C=O bond is syn to the ortho-methyl substituent in the benzoyl ring, similar to what is observed in 2-chloro-N-(2-chlorophenylbenzamide and 2-methyl-N-phenylbenzamide. The amide group makes almost the same dihedral angles of 41.2 (14 and 42.2 (13° with the aniline and benzoyl rings, respectively, while the dihedral angle between the benzoyl and aniline rings is only 7.4 (3°. The molecules in N2CP2MBA are packed into chains through N—H...O hydrogen bonds.
Hughes, Michael J; Mercier, Hélène P A; Schrobilgen, Gary J
2009-05-18
The adduct, (OsO(3)F(2))(2)2XeOF(4), was synthesized by dissolution of the infinite chain polymer, (OsO(3)F(2))(infinity), in XeOF(4) solvent at room temperature followed by removal of excess XeOF(4) under dynamic vacuum at 0 degrees C. Continued pumping at 0 degrees C resulted in removal of associated XeOF(4), yielding (OsO(3)F(2))(2), a new low-temperature phase of OsO(3)F(2). Upon standing at 25 degrees C for 1(1)/(2) h, (OsO(3)F(2))(2) underwent a phase transition to the known monoclinic phase, (OsO(3)F(2))(infinity). The title compounds, (OsO(3)F(2))(infinity), (OsO(3)F(2))(2), and (OsO(3)F(2))(2)2XeOF(4) have been characterized by low-temperature (-150 degrees C) Raman spectroscopy. Crystallization of (OsO(3)F(2))(2)2XeOF(4) from XeOF(4) solution at 0 degrees C yielded crystals suitable for X-ray structure determination. The structural unit contains the (OsO(3)F(2))(2) dimer in which the OsO(3)F(3) units are joined by two Os---F---Os bridges having fluorine bridge atoms that are equidistant from the osmium centers (2.117(5) and 2.107(4) A). The dimer coordinates to two XeOF(4) molecules through Os-F...Xe bridges in which the Xe...F distances (2.757(5) A) are significantly less than the sum of the Xe and F van der Waals radii (3.63 A). The (OsO(3)F(2))(2) dimer has C(i) symmetry in which each pseudo-octahedral OsO(3)F(3) unit has a facial arrangement of oxygen ligands with XeOF(4) molecules that are only slightly distorted from their gas-phase C(4v) symmetry. Quantum-chemical calculations using SVWN and B3LYP methods were employed to calculate the gas-phase geometries, natural bond orbital analyses, and vibrational frequencies of (OsO(3)F(2))(2), (OsO(3)F(2))(2)2XeOF(4), XeOF(4), OsO(2)F(4), and (mu-FOsO(3)F(2))(2)OsO(3)F(-) to aid in the assignment of the experimental vibrational frequencies of (OsO(3)F(2))(2), (OsO(3)F(2))(2)2XeOF(4), and (OsO(3)F(2))(infinity). The vibrational modes of the low-temperature polymeric phase, (OsO(3)F(2))(infinity), have been
Gan, Liyong
2013-06-13
First-principles calculations are used to explore the geometry, bonding, and electronic properties of MoS2/Ti2C and MoS2/Ti2CY2 (Y = F and OH) semiconductor/metal contacts. The structure of the interfaces is determined. Strong chemical bonds formed at the MoS2/Ti2C interface result in additional states next to the Fermi level, which extend over the three atomic layers of MoS2 and induce a metallic character. The interaction in MoS2/Ti2CY2, on the other hand, is weak and not sensitive to the specific geometry, and the semiconducting nature thus is preserved. The energy level alignment implies weak and strong n-type doping of MoS2 in MoS2/Ti2CF2 and MoS2/Ti2C(OH)2, respectively. The corresponding n-type Schottky barrier heights are 0.85 and 0.26 eV. We show that the MoS2/Ti2CF2 interface is close to the Schottky limit. At the MoS2/Ti2C(OH)2 interface, we find that a strong dipole due to charge rearrangement induces the Schottky barrier. The present interfaces are well suited for application in all-two-dimensional devices.
Gan, Liyong; Huang, Dan; Schwingenschlö gl, Udo; Zhao, Yu-Jun
2013-01-01
First-principles calculations are used to explore the geometry, bonding, and electronic properties of MoS2/Ti2C and MoS2/Ti2CY2 (Y = F and OH) semiconductor/metal contacts. The structure of the interfaces is determined. Strong chemical bonds formed at the MoS2/Ti2C interface result in additional states next to the Fermi level, which extend over the three atomic layers of MoS2 and induce a metallic character. The interaction in MoS2/Ti2CY2, on the other hand, is weak and not sensitive to the specific geometry, and the semiconducting nature thus is preserved. The energy level alignment implies weak and strong n-type doping of MoS2 in MoS2/Ti2CF2 and MoS2/Ti2C(OH)2, respectively. The corresponding n-type Schottky barrier heights are 0.85 and 0.26 eV. We show that the MoS2/Ti2CF2 interface is close to the Schottky limit. At the MoS2/Ti2C(OH)2 interface, we find that a strong dipole due to charge rearrangement induces the Schottky barrier. The present interfaces are well suited for application in all-two-dimensional devices.
System of Sr(NO2)2-Sr(OH)2-H2O at 25 deg C
International Nuclear Information System (INIS)
Popova, T.B.; Berdyukova, V.A.; Khutsistova, F.M.
1990-01-01
Sr(NO 2 ) 2 -Sr(OH) 2 -H 2 O system was investigated by the methods of solubility, density, viscosity, electric conductivity and refractometry. It was established that its compoments form the compound 4Sr(NO 2 ) 2 xSr(OH) 2 x8H 2 O. The compound was separated from solution; its density, decomposition temperature were determined; IR spectra and X-ray patterns of prepared and initial compounds were obtained
Zuo, M.; Smith, Steven J.; Chutjian, A.; Williams, I. D.; Tayal, S. S.; Mclaughlin, Brendan M.
1995-01-01
Experimental and theoretical excitation cross sections are reported for the first forbidden transition 4S(O) -- 2S(2)2p(3) 2D(O) (lambda-lambda 3726, 3729) and the first allowed (resonance) transition 4S(O) -- 2s2p(4) 4P(lambda-833) in O II. Use is made of electron energy loss and merged-beams methods. The electron energy range covered is 3.33 (threshold) to 15 eV for the S -- D transition, and 14.9 (threshold) to 40 eV for the S -- P transition. Care was taken to assess and minimize the metastable fraction of the O II beam. An electron mirror was designed and tested to reflect inelastically backscattered electrons into the forward direction to account for the full range of polar scattering angles. Comparisons are made between present experiments and 11-state R-matrix calculations. Calculations are also presented for the 4S(O) -- 2s(2)2p(3)2P(O) (lambda-2470) transition.
Koten, G. van; Kleij, A.W.; Kleijn, H.; Jastrzebski, J.T.B.H.; Smeets, W.J.J.; Spek, A.L.
1999-01-01
A useful synthetic procedure for the incorporation of the potentially multidentate monoanionic 1-[C6H2(CH2NMe2)2-3,5]- (=NCN) and 1-[C6H3(CH2NMe2)-4]- (=CN) ligands via the para-position on the periphery of carbosilane (CS) dendrimers has been developed. Lithiation of suitable brominated precursors
DEELMAN, BJ; STEVELS, WM; TEUBEN, JH; LAKIN, MT; SPEK, AL
1994-01-01
Pyridine is metalated selectively at the 2-position by (Cp*2YH)2 to yield Cp*2Y(2-pyridyl) (1). Compound 1 reacts with H2 to give the hydride addition product Cp*2Y(NC5H6) (2). With THF and pyridine the adducts Cp*2Y(eta2-2-pyridyl)(THF) (3) and Cp*2Y(eta1-2-pyridyl)-(py) (4) are formed. The
Jin, Youzhi; McFie, Pamela J; Banman, Shanna L; Brandt, Curtis; Stone, Scot J
2014-10-10
Acyl CoA:1,2-diacylglycerol acyltransferase (DGAT)-2 is an integral membrane protein that catalyzes triacylglycerol (TG) synthesis using diacylglycerol and fatty acyl CoA as substrates. DGAT2 resides in the endoplasmic reticulum (ER), but when cells are incubated with fatty acids, DGAT2 interacts with lipid droplets presumably to catalyze localized TG synthesis for lipid droplet expansion. Previous studies have shown that DGAT2 interacts with proteins that synthesize its fatty acyl CoA substrates. In this study, we provide additional evidence that DGAT2 is present in a protein complex. Using a chemical cross-linker, disuccinimidyl suberate (DSS), we demonstrated that DGAT2 formed a dimer and was also part of a protein complex of ∼ 650 kDa, both in membranes and on lipid droplets. Using co-immunoprecipitation experiments and an in situ proximity ligation assay, we found that DGAT2 interacted with monoacylglycerol acyltransferase (MGAT)-2, an enzyme that catalyzes the synthesis of diacylglycerol. Deletion mutagenesis showed that the interaction with MGAT2 was dependent on the two transmembrane domains of DGAT2. No significant interaction of DGAT2 with lipin1, another enzyme that synthesizes diacylglycerol, could be detected. When co-expressed in cells, DGAT2 and MGAT2 co-localized in the ER and on lipid droplets. Co-expression also resulted in increased TG storage compared with expression of DGAT2 or MGAT2 alone. Incubating McArdle rat hepatoma RH7777 cells with 2-monoacylglycerol caused DGAT2 to translocate to lipid droplets. This also led to the formation of large cytosolic lipid droplets, characteristic of DGAT2, but not DGAT1, and indicated that DGAT2 can utilize monoacylglycerol-derived diacylglycerol. These findings suggest that the interaction of DGAT2 and MGAT2 serves to channel lipid substrates efficiently for TG biosynthesis. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.
International Nuclear Information System (INIS)
Qi, Guojie; Wang, Shujuan
2017-01-01
Highlights: • A new application of aqueous NH_3 based combined CO_2 and SO_2 process was proposed. • A thermodynamic model simulated the heat of absorption and the K_2SO_4 precipitation. • The CO_2 content can be regenerated in a stripper with lower heat of desorption. • The SO_2 content can be removed by K_2SO_4 precipitation from the lean NH_3 solvent. - Abstract: A new application of aqueous NH_3 based post-combustion CO_2 and SO_2 combined capture process was proposed to simultaneously capture CO_2 and SO_2, and remove sulfite by solid (K_2SO_4) precipitation method. The thermodynamic model of the NH_3-CO_2-SO_2-K_2SO_4-H_2O system for the combined CO_2 and SO_2 capture process was developed and validated in this work to analyze the heat of CO_2 and SO_2 absorption in the NH_3-CO_2-SO_2-H_2O system, and the K_2SO_4 precipitation characteristics in the NH_3-CO_2-SO_2-K_2SO_4-H_2O system. The average heat of CO_2 absorption in the NH_3-CO_2-H_2O system at 40 °C is around −73 kJ/mol CO_2 in 2.5 wt% NH_3 with CO_2 loading between 0.2 and 0.5 C/N. The average heat of SO_2 absorption in the NH_3-SO_2-H_2O system at 40 °C is around −120 kJ/mol SO_2 in 2.5 wt% NH_3 with SO_2 loading between 0 and 0.5 S/N. The average heat of CO_2 absorption in the NH_3-CO_2-SO_2-H_2O system at 40 °C is 77, 68, and 58 kJ/mol CO_2 in 2.5 wt% NH_3 with CO_2 loading between 0.2 and 0.5 C/N, when SO_2 loading is 0, 0.1, 0.2 S/N, respectively. The solubility of K_2SO_4 increases with temperature, CO_2 and SO_2 loadings, but decreases with NH_3 concentration in the CO_2 and SO_2 loaded aqueous NH_3. The thermodynamic evaluation indicates that the combined CO_2 and SO_2 capture process could employ the typical absorption/regeneration process to simultaneously capture CO_2 and SO_2 in an absorber, thermally desorb CO_2 in a stripper, and feasibly remove sulfite (oxidized to sulfate) content by precipitating K_2SO_4 from the lean NH_3 solvent after the lean/rich heat exchanger.
Thermal expansion of Cr2xFe2-2xMo3O12, Al2xFe2-2xMo3O12 and Al2xCr2-2xMo3O12 solid solutions
International Nuclear Information System (INIS)
Ari, M.; Jardim, P.M.; Marinkovic, B.A.; Rizzo, F.; Ferreira, F.F.
2008-01-01
The transition temperature from monoclinic to orthorhombic and the thermal expansion of the orthorhombic phase were investigated for three systems of the family A 2 M 3 O 12 : Cr 2x Fe 2-2x Mo 3 O 12 , Al 2x Fe 2-2x Mo 3 O 12 and Al 2x Cr 2-2x Mo 3 O 12 . It was possible to obtain a single-phase solid solution in all studied samples (x=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1). A linear relationship between the transition temperature and the fraction of A 3+ cations (x) was observed for each system. In all orthorhombic solid solutions studied here the observed thermal expansion was anisotropic. These anisotropic thermal expansion properties of crystallographic axes a, b and c result in a low positive or near-zero overall linear coefficient of thermal expansion (α l =α V /3). The relationship between the size of A 3+ cations in A 2 M 3 O 12 and the coefficient of thermal expansion is discussed. Near-zero thermal expansion of Cr 2 Mo 3 O 12 is explained by the behavior of Cr-O and Mo-O bond distances, Cr-Mo non-bond distances and Cr-O-Mo bond angles with increasing temperature, estimated by Rietveld analysis of synchrotron X-ray powder diffraction data. - Graphical abstract: In this figure, all published overall linear coefficients of thermal expansion for orthorhombic A 2 M 3 O 12 family obtained through diffraction methods as a function of A 3+ cation radii size, together with dilatometric results, are plotted. Our results indicate that Cr 2 Mo 3 O 12 does not exactly follow the established relationship
Ternary indides Eu{sub 2}Pd{sub 2}In and Eu{sub 2}Pt{sub 2}In
Energy Technology Data Exchange (ETDEWEB)
Muts, Ihor [Inorganic Chemistry Department, Ivan Franko National University of Lviv (Ukraine); Institut fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Universitaet Muenster (Germany); Zaremba, Vasyl I. [Inorganic Chemistry Department, Ivan Franko National University of Lviv (Ukraine); Poettgen, Rainer [Institut fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Universitaet Muenster (Germany)
2012-01-15
The indides Eu{sub 2}Pd{sub 2}In and Eu{sub 2}Pt{sub 2}In were synthesized from the elements in sealed tantalum tubes in an induction furnace. The samples were characterized by powder X-ray diffraction. The structures were refined on the basis of single-crystal X-ray diffractometer data: HT-Pr{sub 2}Co{sub 2}Al type, C2/c, a = 1035.7(2), b = 592.9(1), c = 823.6(2) pm, β = 104.26(1) , wR2 = 0.026, 1075 F{sup 2} values, 25 variables for Eu{sub 2}Pd{sub 2}In and a = 1017.2(2), b = 588.7(1), c = 826.5(1) pm, β = 103.76(1) , wR2 = 0.062, 706 F{sup 2} values, 25 variables for Eu{sub 2}Pt{sub 2}In. The indium atoms have four platinum (palladium) neighbors in strongly distorted tetrahedral coordination at Pt-In and Pd-In distances ranging from 273 to 275 pm. These InPd{sub 4/2} and InPt{sub 4/2} units are condensed via common edges to infinite InPd{sub 2} and InPt{sub 2} chains, which are surrounded by the europium atoms. The chains form the motif of hexagonal rod packing. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Substituted 2,2'-bipyridines by nickel-catalysis: 4,4'-di-tert-butyl-2,2'-bipyridine.
Buonomo, Joseph A; Everson, Daniel A; Weix, Daniel J
2013-11-01
A simple, ligand-free synthesis of the important bipyridyl ligand 4,4'-di- tert -butyl-2,2'-bipyridine is presented. 5,5'-bis(trifluoromethyl)-2,2'-bipyridine is also synthesized by the same protocol. The syntheses efficiently couple the parent 2-chlorpyridies by a nickel-catalyzed dimerization with manganese powder as the terminal reductant.
JEF-2.2 radioactive decay data
International Nuclear Information System (INIS)
1994-08-01
This work deals with the JEF-2.2 radioactive decay data and is divided into four tables. The first table presents the origin of the JEF-2.2 radioactive decay data and subsequent modifications. The second one is a summary of the JEF-2.2 radioactive decay data file. The third one describes the JEF-2.2 fission products and the main decay and fission yield data. The last one consists of the main decay parameters from the JEF-2.2, ENDF/B-VI and JNDC-2.0 libraries. (O.L.). 100 figs., 4 tabs
Energy Technology Data Exchange (ETDEWEB)
McNair, A; Wilson, H W [United Kingdom Atomic Energy Authority, Aldermaston, Berks. (United Kingdom)
1962-01-15
especial atencion a una reduccion del espesor de la fuente y de su soporte. Los autores han recurrido a diversos procedimientos para aumentar la precision de las mediciones. El espesor de la fuente se redujo empleando: i) un contador proporcional 4 {pi} de gran superficie util (hasta 100 cm{sup 2}), ii) un circuito de anticoincidencias para disminuir la intensidad de la radiacion de fondo, y iii) {sup 87}Rb enriquecido, lo que permite reducir a la cuarta parte el espesor de la fuente para una actividad dada. De esta forma, se han podido medir fuentes hasta de 5 {mu}g/cm{sup 2}. Tambien examinaron la relacion entre el periodo de semidesintegracion y el espesor de la fuente, a fin de poder introducir una correccion para tener en cuenta la debil absorcion remanente. El efecto del espesor del soporte de la fuente no estan considerable y puede calcularse partiendo: i) de la diferencia entre la velocidad de recuento en ambos lados de los delgados soportes utilizados, y ii) de un estudio de la relacion existente entre el periodo de semidesintegracion y el espesor del soporte de la fuente. Estos experimentos dan un valor aproximado de 5,25 x 10{sup 12} anos para el periodo de semidesintegracion del {sup 87}Rb. (author) [Russian] Period poluraspada Rb''8''7 izmeryalsya neposredstvenno putem opredeleniya spetsificheskoj aktivnosti metodom scheta. Poluchennye ranee periody poluraspada nakhodyatsya v predelakh 4 - 6 kh 10''1''0 let s velichinoj, kotoraya beretsya obychno v 5 kh 10''1''0 let. Metod pryamogo scheta yavlyaetsya dovol'no slozhnym iz-za nalichiya bol'shogo chisla ehlektronov ochen' maloj ehnergii v spektre rubidiya-87. Odnako ves'ma aktual'nym yavlyaetsya poluchenie tochnoj velichiny metodom scheta, t.e. to, chto avtory pytalis' prodelat'. V ehtikh izmereniyakh sleduet udelit' osoboe vnimanie umen'sheniyu tolshchiny istochnika i ego podkladki. Dlya uvelicheniya tochnosti izmerenij byli ispol'zovany sleduyushchie metody. Tolshchina istochnika umen'shalas' putem ispol
International Nuclear Information System (INIS)
Tsivadze, A.Yu.; Minacheva, L.Kh.; Ivanova, I.S.; Pyatova, E.N.; Sergienko, V.S.; Baulin, V.E.
2008-01-01
Paper describes synthesis of CuL 2 ·2H 2 O (I) complex cupric salt and of Er(NO 3 ) 3 ·2HL·2H 2 O (II) erbium nitrate complex (HL=2-diazo-[2'(oxymethyl-diphenyl-phosphinyl)phenyl]-4-tert-butylphenol). One interprets the fundamental frequencies within the IR-spectra of (I) and (II) compounds. One has performed X-ray diffraction analysis of I compound. The crystals are monoclinic ones, a=15.157(3), b=17.080(2), c=22.451(9) A, β=106.09(3) Deg, V=5584(3) A 3 , Z=4, C2/c sp.gr., R=0.0546 as to 1152 reflections with I>2σ(I). The copper atom coordination polyhedron (C 2 symmetry) may be described as a symmetrically-prolonged square bipyramid (4+2). Cu polyhedron central square is formed by substituted phenol oxygen atom and by one of diazo-group nitrogen atoms of either of two deprotonated ligands, namely: L - (Cu-N 1.969(6), Cu-O 1.899(5) A). The angles between lying opposite O and N atoms constitute 157.6 Deg, while the rest equatorial angles range within 90.6 Deg-95.9 Deg. The axial positions are occupied by O(2) and O(2A) anisole atoms (Cu-O 2.737(6) A, O(2)Cu(1)O(2A) angle constitutes 132.3 Deg). Within crystal I the complex molecules and the crystallization molecules of water are combined by by the hydrogen bond system. According to the IR-spectra data, within complex II in contrast to compound I erbium atom coordination by HL ligand involves oxygen phosphoryl atom [ru
Directory of Open Access Journals (Sweden)
Mihailo R. Mrdak
2015-01-01
of efficiency of the compressor by 10% while reducing fuel consumption by 8%. / U ovom istraživanju prikazan je efekat primene mekih zaptivki deponovanih atmosferski plazma sprej - APS procesom na delovima kompresora turbomlaznog motora TV2-117A. Na delovima kompresora primenjena je prvi put zapadna plazma sprej tehnologija i materijali. Cilj je bio da se izvrši supstitucija postojećeg zaptivnog materijala sa novom klasom materijala, da bi se povećao efekat zaptivanja i obezbedio protok vazduha pod najvećim pritiskom kroz kompresor. Meke zaptivke su formirane kao dupleks sistemi koji se sastoje od donjeg veznog sloja na bazi NiCrAl i NiAl prevlaka i gornjih zaptivnih prevlaka na bazi slojeva Ni - 15% grafita, Ni - 25% grafita i AlSi - poliestera. U radu su prikazani parametri sa kojima su deponovane prevlake na delovima kompresora, mehaničke i mikrostrukturne karakteristike prevlaka proizvedenih sa optimalnim parametrima depozicije. Procena mehaničkih karakteristika prevlaka urađena je ispitivanjem mikrotvrdoće veznih slojeva metodom HV0.3 i makrotvrdoće zaptivnih slojeva metodom HR15W. Zatezne čvrstoće spoja dupleks sistema prevlaka ispitane su metodom kidanja na zatezanje. Mikrostrukture slojeva prevlaka su procenjene na optičkom mikroskopu - OM. Analiza mikrostruktura deponovanih slojeva urađena je u skladu sa standardom Pratt-Whitney i TURBOMECA. Pohabanost prevlaka određena je na osnovu promene dimenzija zaptivnih površina pre i posle ispitivanja. Merenje dimenzija rađeno je na koordinatnoj mernoj mašini MAUSER ML 28. U radu je prikazana srednja vrednost pohabanosti izražena u mm i upoređena sa vrednostima dozvoljenih tolerancija mašinski obrađenih delova kompresora. Efekat zaptivanja delova kompresora ispitan je u sklopu motora TV2-117A na ispitnoj stanici i letnim ispitivanjem na helikopteru Mi-8(HT-40. Ispitivanja su pokazala da je novim sistemom zaptivnih prevlaka povećan stepen iskorišćenja kompresora za 10% uz smanjenu potro
Directory of Open Access Journals (Sweden)
Jaber SALEHZADEH
2013-11-01
Full Text Available The hazardous ill effects of heavy metals on the environment and public health is a matter of serious concern. Biosorption is emerging as a sustainable effective technology. Heavy metals in water resources are one of the most important environmental problems of countries. The intensification of industrial activity and environmental stress greatly contributes to the significant rise of heavy metal pollution in water resources making threats on terrestrial and aquatic life. The toxicity of metal pollution is slow and interminable, as these metal ions are non bio-degradable. The adsorption capacity of Xanthium Pensylvanicum towards metal ions such as Pb2+, Cu2+, Zn2+, Cd2+, Ni2+, Co2+ and Fe3+, was studied. The adsorption capacity was performed by batch experiments as a function of process parameters (such as sorption time and pH. Experimental results showed that the removal percentages increasing of metal ions at pH=4, initial concentration of metal ions 10 mg/L, and after 90 min of shaking was: Zn2+ < Cd2+ < Cu2+ < Pb2+ < Ni2+ < Fe3+ < Co2+.
Directory of Open Access Journals (Sweden)
Nimisha Mittal
2017-05-01
Full Text Available Leishmania donovani, a protozoan parasite is the major causative agent of visceral leishmaniasis. Increased toxicity and resistance to the existing repertoire of drugs has been reported. Hence, an urgent need exists for identifying newer drugs and drug targets. Previous reports have shown sirtuins (Silent Information Regulator from kinetoplastids as promising drug targets. Leishmania species code for three SIR2 (Silent Information Regulator related proteins. Here, we for the first time report the functional characterization of SIR2 related protein 2 (SIR2RP2 of L. donovani.Recombinant L. donovani SIR2RP2 was expressed in E. coli and purified. The enzymatic functions of SIR2RP2 were determined. The subcellular localization of LdSIR2RP2 was done by constructing C-terminal GFP-tagged full-length LdSIR2RP2. Deletion mutants of LdSIR2RP2 were generated in Leishmania by double targeted gene replacement methodology. These null mutants were tested for their proliferation, virulence, cell cycle defects, mitochondrial functioning and sensitivity to known SIR2 inhibitors.Our data suggests that LdSIR2RP2 possesses NAD+-dependent ADP-ribosyltransferase activity. However, NAD+-dependent deacetylase and desuccinylase activities were not detected. The protein localises to the mitochondrion of the promastigotes. Gene deletion studies showed that ΔLdSIR2RP2 null mutants had restrictive growth phenotype associated with accumulation of cells in the G2/M phase and compromised mitochondrial functioning. The null mutants had attenuated infectivity. Deletion of LdSIR2RP2 resulted in increased sensitivity of the parasites to the known SIR2 inhibitors. The sirtuin inhibitors inhibited the ADP-ribosyltransferase activity of recombinant LdSIR2RP2. In conclusion, sirtuins could be used as potential new drug targets for visceral leishmaniasis.
Rate constant and thermochemistry for K + O2 + N2 = KO2 + N2
DEFF Research Database (Denmark)
Sorvajärvi, Tapio; Viljanen, Jan; Toivonen, Juha
2015-01-01
in the form of double exponential decays of [K], which yielded both kR1 and the equilibrium constant for KO2 formation. kR1 can be summarized as 1.07 × 10-30(T/1000 K)-0.733 cm6 molecule-2 s-1. Combination with literature values leads to a recommended kR1 of 5.5 × 10-26T-1.55 exp(-10/T) cm6 molecule-2 s-1...... over 250-1320 K, with an error limit of a factor of 1.5. A vant Hoff analysis constrained to fit the computed ΔS298 yields a K-O2 bond dissociation enthalpy of 184.2 ± 4.0 kJ mol-1 at 298 K and ΔfH298(KO2) = -95.2 ± 4.1 kJ mol-1. The corresponding D0 is 181.5 ± 4.0 kJ mol-1. This value compares well...
12,12′-[2,2′-Oxybis(ethane-2,1-diylbis(oxy]bis[(Rp-4-bromo[2.2]paracyclophane
Directory of Open Access Journals (Sweden)
Bing Hong
2011-04-01
Full Text Available The title compound, C36H36Br2O3, was synthesized from (Rp-4-bromo-12-hydroxy[2.2]paracyclophane and oxydiethane-2,1-diyl bis(4-methylbenzenesulfonate. The crystal packing exhibits a short O...Br interaction [Br...O = 3.185 (3 Å] and a weak intermolecular C—H...O contact.
Wang, Yi-Ying; Dash, Manas Ranjan; Chung, Chao-Yu; Lee, Yuan-Pern
2018-02-01
We recorded time-resolved infrared absorption spectra of transient species produced on irradiation at 308 nm of a flowing mixture of CH2I2/O2/N2/SO2 at 298 K. Bands of CH2OO were observed initially upon irradiation; their decrease in intensity was accompanied by the appearance of an intense band at 1391.5 cm-1 that is associated with the degenerate SO-stretching mode of SO3, two major bands of HCHO at 1502 and 1745 cm-1, and five new bands near >1340, 1225, 1100, 940, and 880 cm-1. The band near 1340 cm-1 was interfered by absorption of SO2 and SO3, so its band maximum might be greater than 1340 cm-1. SO3 in its internally excited states was produced initially and became thermalized at a later period. The rotational contour of the band of thermalized SO3 agrees satisfactorily with the reported spectrum of SO3. These five new bands are tentatively assigned to an intermediate 1,3,2-dioxathietane-2,2-dioxide [cyc-(CH2)O(SO2)O] according to comparison with anharmonic vibrational wavenumbers and relative IR intensities predicted for this intermediate. Observation of a small amount of cyc-(CH2)O(SO2)O is consistent with the expected reaction according to the potential energy scheme predicted previously. SO3+HCHO are the major products of the title reaction. The other predicted product channel HCOOH+SO2 was unobserved and its branching ratio was estimated to be <5%.
Mukherjee, Sriparna; Liu, Chang; Jakubikova, Elena
2018-02-22
Fe(II)-polypyridines have limited applications as chromophores in dye-sensitized solar cells due to the short lifetimes (∼100 fs) of their photoactive metal-to-ligand charge transfer (MLCT) states formed upon photoexcitation. Recently, a 100-fold increase in the MLCT lifetime was observed in a [Fe(CNC) 2 ] 2+ complex (CNC = 2,6-bis(3-methylimidazole-1-ylidine)pyridine) which has strong σ-donating N-heterocyclic carbene ligand in comparison to the weaker field parent [Fe(tpy) 2 ] 2+ complex (tpy = 2,2':6',2″-terpyridine). This study utilizes density functional theory (DFT), time-dependent DFT, and quantum dynamics simulations to investigate the interfacial electron transfer (IET) in [Fe(cCNC) 2 ] 2+ (cCNC = 4'-carboxy-2,6-bis(3-methylimidazole-1-ylidine)pyridine) and [Fe(ctpy) 2 ] 2+ (ctpy = 4'-carboxy-2,2':6',2″-terpyridine) sensitized TiO 2 . Our results suggest that the replacement of tpy by CNC ligand does not significantly speed up the IET kinetics in the [Fe(cCNC) 2 ] 2+ -TiO 2 assembly in comparison to the [Fe(ctpy) 2 ] 2+ -TiO 2 analogue. The high IET efficiency in the [Fe(cCNC) 2 ] 2+ -TiO 2 assemblies is therefore due to longer lifetime of [Fe(cCNC) 2 ] 2+ photoactive 3 MLCT states rather than faster electron injection kinetics. It was also found that the inclusion of conformational sampling in the computational model is important for proper description of the IET processes in these systems, as the models relying on the use of only fully optimized structures may yield misleading results. The simulations presented in this work also illustrate various pitfalls of utilizing properties such as electronic coupling, number of available acceptor states, and driving force, as well as calculations based on Fermi's golden rule framework, to reach conclusions on the IET efficiency in dye-semiconductor systems.
Energy Technology Data Exchange (ETDEWEB)
Neveu, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1961-07-01
We study various compounds resulting from the interaction of UO{sub 2}F{sub 2} with H{sub 2}O and HF (gas), and various triple compounds UO{sub 2}F{sub 2} - H{sub 2}O - HF; the conditions of decomposition and the thermodynamic limits of stability are specified. (author) [French] Nous etudions divers composes formes par reaction de UO{sub 2}F{sub 2} avec H{sub 2}O et HF (gaz) et divers composes triples UO{sub 2}F{sub 2} - H{sub 2}O - HF, en essayant de preciser les decompositions et domaines d'exisfence thermodynamiques de ces corps. (auteur)
Li, Minghua; Li, Zhiqin; Morris, David L.; Rui, Liangyou
2007-01-01
The SH2B family has three members (SH2B1, SH2B2, and SH2B3) that contain conserved dimerization (DD), pleckstrin homology, and SH2 domains. The DD domain mediates the formation of homo- and heterodimers between members of the SH2B family. The SH2 domain of SH2B1 (previously named SH2-B) or SH2B2 (previously named APS) binds to phosphorylated tyrosines in a variety of tyrosine kinases, including Janus kinase-2 (JAK2) and the insulin receptor, thereby promoting the activation of JAK2 or the ins...
Enomoto, Takeshi; Matsumoto, Kazuhiko; Hagiwara, Rika
2011-12-14
A room temperature ionic liquid (IL) based on the fluorosulfate anion (SO(3)F(-)) has been synthesized by the reaction of 1-ethyl-3-methylimidazolium (EMIm(+)) chloride and fluorosulfuric acid (HOSO(2)F). The viscosity, ionic conductivity, and electrochemical window of EMImSO(3)F at 25 °C are 46.6 mPa s, 10.8 mS cm(-1), and 4.3 V, respectively. According to a solvatochromic measurement using ILs, there is a trend in the donor ability of fluoro- and oxofluoroanions, PF(6)(-) OSO(2)F and EMIm(FO(2)SOH)(2)O(2)SOF, respectively. Both the salts are liquid at room temperature without a HOSO(2)F dissociation pressure (OSO(2)F and 5.1 mPa s and 43.2 mS cm(-1) for EMIm(FO(2)SOH)(2)O(2)SOF). The vibrational modes and bonding properties of these anionic species are discussed with the aid of quantum mechanical calculations. The (FO(2)SOH)OSO(2)F(-) anion in EMIm(FO(2)SOH)OSO(2)F does not have an inversion centre, which stands in contrast to the one with an inversion centre (e.g. observed in solid Cs(FO(2)SOH)OSO(2)F). The (FO(2)SOH)(2)O(2)SOF(-) anion in EMIm(FO(2)SOH)(2)O(2)SOF is characterized by vibrational spectroscopy under C(s) symmetry.
International Nuclear Information System (INIS)
Abraham, T.W.; Leete, Edward
1996-01-01
2-Ethoxy-1-methyl-5-pyrrolidinone (1) was reacted with ethyl [3,4- 13 C 2 ]-acetoacetate (2) in the presence of TiCl 4 to give ethyl [3,4- 13 C 2 ]-2-(1'-methyl-5'-oxo-2'-pyrrolidinyl)-3-oxobutanoate (3) in 85% yield. Decarboethoxylation of ethyl [3,4- 13 C 2 ]-2-(1'-methyl-5'-oxo-2'-pyrrolidinyl)-3-oxobutan-oate (3) was accomplished using NaCl and H 2 O in DMSO to give (R,S)-[2,3- 13 C 2 ]-1-(1'-methyl-5'-oxo-2'-pyrrolidinyl)propan-2-o ne (4) in 91% yield. Protection of the ketone as a ketal (ethylene glycol, H + ), followed by reduction of the amide to the amine using LiAlH 4 and subsequent deprotection of the ketal gave (R,S)-[2,3- 13 C 2 ]-1-(1'-methyl-2'-pyrrolidinyl)propan-2-one ((R,s)-[2', 3'- 13 C 2 ]Hygrine) (8) in 78% yield. (61% overall yield from ethyl [3,4- 13 C 2 ]acetoacetate). (Author)
Complexes of Zn(2) and Cd(2) with 2-methyl-benzimidazole
Energy Technology Data Exchange (ETDEWEB)
Slyusarenko, K F; Artemenko, M V; Pokhodnya, G A; Kononenko, O.M. (Kievskij Tekhnologicheskij Inst. Pishchevoj Promyshlennosti (Ukrainian SSR))
1978-07-01
Coordination compounds of Zn(2) and Cd(2) salts with 2-methyl-benzimidazole (MBI) of 2MBIxMeX/sub 2/ composition, where Me is Zn (2), Cd (2); X is NO/sub 3//sup -/, CH/sub 3/COO/sup -/, CL/sup -/, Br/sup -/, I/sup -/, 1/2SO/sub 4//sup -2/, as well as acid compounds of (MBIH)/sub 2/(CdX/sub 4/) composition, where X is Cl/sup -/, Br/sup -/, I/sup -/, have been obtained and investigated. The synthetized compounds are of white colour, they are stable in air, soluble in alcohols, decomposed by water. Decomposition temperatures for most of the Cd(2) compounds lie above 250 deg C. Infrared spectra and diffractograms of these compounds have been studied. From the curves of radial distribution of atomic density, the ionic nature of the bonding of halide groups in the complexes has been established.
Oxidation mechanisms of CF2Br2 and CH2Br2 induced by air nonthermal plasma.
Schiorlin, Milko; Marotta, Ester; Dal Molin, Marta; Paradisi, Cristina
2013-01-02
Oxidation mechanisms in air nonthermal plasma (NTP) at room temperature and atmospheric pressure were investigated in a corona reactor energized by +dc, -dc, or +pulsed high voltage.. The two bromomethanes CF(2)Br(2) and CH(2)Br(2) were chosen as model organic pollutants because of their very different reactivities with OH radicals. Thus, they served as useful mechanistic probes: they respond differently to the presence of humidity in the air and give different products. By FT-IR analysis of the postdischarge gas the following products were detected and quantified: CO(2) and CO in the case of CH(2)Br(2), CO(2) and F(2)C ═ O in the case of CF(2)Br(2). F(2)C ═ O is a long-lived oxidation intermediate due to its low reactivity with atmospheric radicals. It is however removed from the NTP processed gas by passage through a water scrubber resulting in hydrolysis to CO(2) and HF. Other noncarbon containing products of the discharge were also monitored by FT-IR analysis, including HNO(3) and N(2)O. Ozone, an important product of air NTP, was never detected in experiments with CF(2)Br(2) and CH(2)Br(2) because of the highly efficient ozone depleting cycles catalyzed by BrOx species formed from the bromomethanes. It is concluded that, regardless of the type of corona applied, CF(2)Br(2) reacts in air NTP via a common intermediate, the CF(2)Br radical. The possible reactions leading to this radical are discussed, including, for -dc activation, charge exchange with O(2)(-), a species detected by APCI mass spectrometry.
Mastering JavaServer Faces 2.2
Leonard, Anghel
2014-01-01
A homogenous guide integrating the features of JSF 2.x (2.0, 2.1 and 2.2), following a "learning through examples" paradigm with its main focus on the advanced concepts of JSF. If you are a web developer who uses JSF, this is the book for you. Catering to an intermediate-advanced audience, the book assumes you have fundamental knowledge of JSF. It is intended for the developer who wants to improve their skills with the combined power of JSF 2.0, 2.1, and 2.2.
Near-threshold electron-impact excitation of the (2p53s2)2P3/2,1/2 autoionizing states in sodium
International Nuclear Information System (INIS)
Borovik, A; Zatsarinny, O; Bartschat, K
2008-01-01
The ejected-electron excitation functions of the J = 3/2, 1/2 components of the (2p 5 3s 2 ) 2 P leading autoionizing doublet in sodium atoms were measured at an incident electron energy resolution of 0.25 eV over the incident electron energy range from the lowest excitation threshold up to 36 eV. On the basis of 56-state R-matrix (close-coupling) calculations, the observed strong near-threshold structures were classified as negative-ion resonances with likely configurations 2p 5 3s 2 3p and 2p 5 3s3p 2
(Pyridine-2-aldoximato-κ2N,N′bis[2-(pyridin-2-ylphenyl-κ2C1,N]iridium(III
Directory of Open Access Journals (Sweden)
Bimal Chandra Singh
2013-03-01
Full Text Available In the title complex, [Ir(C11H8N2(C6H5N2O], the octahedrally coordinated IrIII atom is bonded to two 2-(pyridin-2-ylphenyl ligands, through two phenyl C and two pydidine N atoms, and to one pyridine-2-aldoxime ligand through a pyridine N and an oxime N atom. The oxime O atom of the aldoxime unit forms intermolecular C—H...O hydrogen bonds, which result in a two-dimensional hydrogen-bonded polymeric network parallel to (100. C—H...π interactions are also observed.
Theoretical investigation of isomerism in dimers (HBO)2, (HBS)2, (HAlO)2 and (HAlS)2
International Nuclear Information System (INIS)
Zyubina, T.S.; Charkin, O.P.
1991-01-01
Using several basic sets and taking into account electron correlation, non-empiric calculations of the structure and relative stability of (HBO) 2 , (HBS) 2 , (HAlO) 2 and (HAlS) 2 dimers were made. Isomers of (HA) 2 Y 2 structure (A = B, Al; Y O,S) have the highest stability, isomers of A 2 (YH) 2 structure are more than 20 kcal/mol less stable. High potential barrier hampers transition frome one isomer to the other. Stability of (HA) 2 Y 2 dimer to decomposition into monomers (HAY+HAY) increases in the series HBS-HBO-HAlS-HAlO
Energy Technology Data Exchange (ETDEWEB)
Snisarenko, V I; Mel` nikov, A I [Myinyisterstvo Budyivel` noyi Arkhyitekturi, Kyiv (Ukraine); [Myizhgaluzevij Naukovo-Tekhnyichnij Tsentr ` ` Ukrittya ` ` , Natsyional` na Akademyiya Nauk Ukrayini, Chornobil` (Ukraine)
1994-12-31
Construction of the cut-off-curtain (COC) is analyzed as a possible variant to reduce the rate of radioactive horizontal migration. Such constructions can be executed by the << wall-in-the ground >> method. The theoretical analysis of the stress-strained state of the carried out using the methods of the theory of elasticity and of the limit equilibrium of the strewing medium. Theoretical dependences are obtained and formulas for practical calculations of the COC-body stress-strained state in the depth intervals which are of practical interest are suggested. The dependences obtained may be used to calculate the consolidation parameters and filtration coefficients, to choose materials for the COC body, geometrical size and film elements included.
Dimethyl 2,2′-[Carbonylbis(azanediyl](2S,2′S-bis[3-(4-hydroxyphenylpropanoate
Directory of Open Access Journals (Sweden)
Raffaella Mancuso
2018-02-01
Full Text Available The thus-far unknown ureic derivative dimethyl 2,2′-[carbonylbis(azanediyl](2S,2′S-bis[3-(4-hydroxyphenylpropanoate] has been efficiently synthesized by enantiospecific oxidative carbonylation of readily available l-tyrosine methyl ester, using a very simple catalytic system (PdI2 in conjunction with KI under relatively mild conditions (100 °C for 5 h in DME as the solvent and under 20 atm of a 4:1 mixture CO-air.
Water Soluble Cationic Porphyrin Sensor for Detection of Hg2+, Pb2+, Cd2+, and Cu2+
Directory of Open Access Journals (Sweden)
Matibur Zamadar
2016-01-01
Full Text Available Here we report the sensing properties of the aqueous solution of meso-tetra(N-methyl-4-pyridylporphine tetrachloride (1 for simultaneous detection of toxic metal ions by using UV-vis spectroscopy. Cationic porphyrin 1 displayed different electronic absorptions in UV-vis region upon interacting with Hg2+, Pb2+, Cd2+, and Cu2+ ions in neutral water solution at room temperature. Quite interestingly, the porphyrin 1 showed that it can function as a single optical chemical sensor and/or metal ion receptor capable of detecting two or more toxic metal ions, particularly Hg2+, Pb2+, and Cd2+ ions coexisting in a water sample. Porphyrin 1 in an aqueous solution provides a unique UV-vis sensing system for the determination of Cd2+ in the presence of larger metal ions such as Hg2+, or Pb2+. Finally, the examination of the sensing properties of 1 demonstrated that it can operate as a Cu2+ ion selective sensor via metal displacement from the 1-Hg2+, 1-Pb2+, and 1-Cd2+.
Directory of Open Access Journals (Sweden)
Márta Palkó
2011-09-01
Full Text Available all-endo-3-amino-5-hydroxybicyclo[2.2.2]octane-2-carboxylic acid (13 and all-endo-5-amino-6-(hydroxymethylbicyclo[2.2.2]octan-2-ol (10 were prepared via dihydro-1,3-oxazine or g-lactone intermediates by the stereoselective functionalization of an N-protected derivative of endo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylic acid (2. Ring closure of b-amino ester 4 resulted in tricyclic pyrimidinones 15 and 16. The structures, stereochemistry and relative configurations of the synthesized compounds were determined by IR and NMR.
Superconductivity in intercalated and substituted Y2Br2C2
International Nuclear Information System (INIS)
Baecker, M.; Simon, A.; Kremer, R.K.; Mattausch, H.J.; Dronskowski, R.; Rouxel, J.
1996-01-01
Layer compounds of the type Y 2 X 2 C 2 (X=Cl, Br, I) show superconductivity at temperatures between 2.3 and 11.2 K. The transition temperature is related to the tendency of conduction electrons toward pairwise localization in C 2 -π * states at the Fermi level, and changes with the concentration of valence electrons, which is varied by intercalation of Na. (orig.)
International Nuclear Information System (INIS)
Palmer, C.J.; Casida, J.E.
1991-01-01
Protection of the terminal alkyne function in 1-(4-ethynylphenyl)-4-(prop-2-enyl)-2,6,7-trioxabicyclo[2.2.2] octane with a trimethylsilyl group permits the selective catalytic reduction of the olefin moiety with tritium gas to give after deprotection 1-(4-ethynylphenyl)-4-[2,3- 3 H 2 ] propyl-2,6,7-trioxabicyclo-[2.2.2] octane. The labeled product at high specific activity is an improved radioligand for the GABA-gated chloride channel of insects and mammals and the intermediate 4-[2,3- 3 H 2 ]propyl-1-[4-[(trimethylsilyl)ethynyl]phenyl]-2,6,7-trioxabicyclo[2.2.2]octane is useful for studies on the metabolic activation of this selective proinsecticide. (author)
RASCAL Version 2.1 workbook. Volume 2, Revision 2
International Nuclear Information System (INIS)
Athey, G.F.; Sjoreen, A.L.; McKenna, T.J.
1994-12-01
The Radiological Assessment System for Consequence Analysis, Version 2.1 (RASCAL 2.1) was developed for use by the NRC personnel who respond to radiological emergencies. This workbook complements the RASCAL 2.1 User's guide (NUREG/CR-5247, Vol. 1, Rev. 2). The workbook contains exercises designed to familiarize the user with the computer-based tools of RASCAL through hands-on problem solving. The workbook contains four major sections. The first is a RASCAL familiarization exercise to acquaint the user with the operation of the forms, menus, online help, and documentation. The latter three sections contain exercises in using the three tools of RASCAL Version 2.1: DECAY, FM-DOSE, and ST-DOSE. A discussion section describing how the tools could be used to solve the problems follows each set of exercises
The new carbodiimide Li_2Gd_2Sr(CN_2)_5 having a crystal structure related to that of Gd_2(CN_2)_3
International Nuclear Information System (INIS)
Unverfehrt, Leonid; Stroebele, Markus; Meyer, H. Juergen
2013-01-01
The new carbodiimide compounds Li_2RE_2Sr(CN_2)_5 (RE = Sm, Gd, Eu, Tb) were prepared by a straight forward solid state metathesis reaction of REF_3, SrF_2, and Li_2(CN_2) at around 600 C. The crystal structure of Li_2Gd_2Sr(CN_2)_5 was solved based on X-ray single-crystal diffraction data. Corresponding Li_2RE_2Sr(CN_2)_5 compounds were analyzed by isotypic indexing of their powder patterns. The crystal structure of Li_2Gd_2Sr(CN_2)_5 can be well related to that of Gd_2(CN_2)_3, because both structures are based on layered structures composed of close packed layers of [N=C=N]"2"- sticks, alternating with layers of metal ions. The crystal structure of Li_2Gd_2Sr(CN_2)_5 can be considered to contain an ABC layer sequence of [N = C=N]"2"- layers with the interlayer voids being occupied by (three) distinct types of cations. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Directory of Open Access Journals (Sweden)
Nezamaddin Daneshvar
2007-03-01
Full Text Available UV/H2O2, UV/H2O2/Fe (II and UV/H2O2/Fe (III processes are very effective in removing pollutants from wastewater and can be used for treatment of dyestuff units wastewaters. In this study, Rhodamine B was used as a typical organic dye. Rhodamine B has found wide applications in wax, leather, and paper industries. The results from this study showed that this dye was degradable in the presence of hydrogen peroxide under UV-C irradiation (30W mercury light and Photo-Fenton process. The dye was resistant to UV irradiation. In the absence of UV irradiation, the decolorization efficiency was very negligible in the presence of hydrogen. The effects of different system variables such as initial dye concentration, duration of UV irradiation, and initial hydrogen peroxide concentration were investigated in the UV/H2O2 process. Investigation of the kinetics of the UV/H2O2 process showed that the semi-log plot of the dye concentration versus time was linear, suggesting a first order reaction. It was found that Rhodamine B decolorization efficiencies in the UV/H2O2/Fe (II and UV/H2O2/Fe (III processes were higher than that in the UV/H2O2 process. Furthermore, a solution containing 20 ppm of Rhodamine B was decolorized in the presence 18 mM of H2O2 under UV irradiation for 15 minutes. It was also found that addition of 0.1 mM Fe(II or Fe(III to the solution containing 20 ppm of the dye and 5 mM H2O2 under UV light illumination decreased removal time to 10 min.
International Nuclear Information System (INIS)
Kuznetsov, V.V.
2005-01-01
New reactions of five-, six-, and seven-membered 1,3-dioxacycloalkanes and their 2-arsena, 2-bora, 2-germa, 2-sila, and 2-thia analogs with nitriles giving rise to 1,3-oxazacycloalkanes and then to amino alcohols are surveyed. The reactions under consideration, including the reactions of boronic and boric acid esters with nitriles, supplement the known chemical transformations of 1,3-dioxacycloalkanes and their 2-hetero atomic analogs and provide a wide scope for the synthesis of diverse functional derivatives on their basis [ru
Csige, I
2003-01-01
sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn in the human environment are considered to be a risk factor because of the radiation dose due to the inhalation of their short-lived daughters. Main source of radon is usually the soil; therefore the measurement of fluxes of sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn on soil surfaces is often a relevant parameter to characterise building site radon potential. An etched track detector technique was developed to measure long-time average sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn fluxes. (R.P.)
Reese, Colin B; Wu, Qinpei
2003-09-21
The synthesis of 2-amino-5-(2-deoxy-beta-D-ribofuranosyl)pyridine 2a, 2-amino-5-(2-deoxy-alpha-D-ribofuranosyl)-pyridine 23, 2-amino-5-(2-deoxy-beta-D-ribofuranosyl)-3-methylpyridine 2b, 2-amino-5-(2-deoxy-alpha-D-ribofuranosyl)-3-methylpyridine 29 and 5-(2-deoxy-beta-D-ribofuranosyl)-2,4-dioxopyrimidine [2'-deoxypseudouridine] 30a is described. These C-nucleosides are prepared either from 2-deoxy-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-ribofuranose 15 or from 2-deoxy-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-ribono-1,4-lactone 16, which are themselves prepared from 2-deoxy-D-ribose 13. The sugar derivatives are first allowed to react with the appropriate 5-lithio-pyridine or 5-lithio-pyrimidine derivatives, which are prepared from 5-bromo-2-(dibenzylamino)pyridine 12a, 5-bromo-2-[bis(4-methoxybenzyl)amino]pyridine 12b, 5-bromo-2-dibenzylamino-3-methylpyridine 25 and 5-bromo-2,4-bis(4-methoxybenzyloxy)pyrimidine 33. The products from the reactions between the lithio-derivatives and the lactol 15 are cyclized under Mitsunobu conditions; the products from the reactions between the lithio-derivatives and the lactone 16 are first reduced with L-Selectride before cyclization, also under Mitsunobu conditions. In all cases, the beta-anomers of the protected C-nucleosides are the predominant products. Finally, the separation of the alpha- and beta-anomers and the removal of all of the protecting groups are described.
Energy Technology Data Exchange (ETDEWEB)
Egorova, O. A. [People’s Friendship University of Russia (Russian Federation); Polyakova, I. N., E-mail: polyakova@igic.ras.ru; Sergienko, V. S. [Russian Academy of Sciences, Kurnakov Institute of General and Inorganic Chemistry (Russian Federation); Davydov, V. V. [People’s Friendship University of Russia (Russian Federation)
2016-07-15
The crystal structure of 2,2’-(quinoxaline-2,3-diyl)dipyridinium dinitrate (H{sub 2}L)(NO{sub 3}){sub 2} is studied by X-ray diffraction (T = 150 K, R1 = 0.0467). The H{sub 2}L{sup 2+} cation is located on the twofold rotation axis and connected with two NO{sub 3}{sup −} anions by strong N–H···O hydrogen bonds. Planar quinoxaline fragments of cations form stacks with the interplanar spacing of 3.308 Å. The structure of the diprotonated H{sub 2}L{sup 2+} cation is compared with those of the monoprotonated H{sub 2}L{sup 2+} cation and neutral L molecule.
International Nuclear Information System (INIS)
Liu, Yingjie; Cao, Jing; Wang, Yujie; Li, Yanzhou; Zhao, Junwei; Chen, Lijuan; Ma, Pengtao; Niu, Jingyang
2014-01-01
An organic–inorganic hybrid sandwich-type tungstoantimonate [Cu(en) 2 (H 2 O)] 4 [Cu(en) 2 (H 2 O) 2 ][Cu 2 Na 4 (α-SbW 9 O 33 ) 2 ]·6H 2 O (1) has been synthesized by reaction of Sb 2 O 3 , Na 2 WO 4 ·2H 2 O, CuCl 2 ·2H 2 O with en (en=ethanediamine) under hydrothermal conditions and structurally characterized by elemental analysis, inductively coupled plasma atomic emission spectrometry, IR spectrum and single-crystal X-ray diffraction. 1 displays a centric dimeric structure formed by two equivalent trivacant Keggin [α-SbW 9 O 33 ] 9− subunits sandwiching a hexagonal (Cu 2 Na 4 ) cluster. Moreover, those related hexagonal hexa-metal cluster sandwiched tungstoantimonates have been also summarized and compared. The variable-temperature magnetic measurements of 1 exhibit the weak ferromagnetic exchange interactions within the hexagonal (Cu 2 Na 4 ) cluster mediated by the oxygen bridges. - Graphical abstract: An organic–inorganic hybrid (Cu 2 Na 4 ) sandwiched tungstoantimonate [Cu(en) 2 (H 2 O)] 4 [Cu (en) 2 (H 2 O) 2 ][Cu 2 Na 4 (α-SbW 9 O 33 ) 2 ]·6H 2 O was synthesized and magnetic properties was investigated. Display Omitted - Highlights: • Organic–inorganic hybrid sandwich-type tungstoantimonate. • (Cu 2 Na 4 sandwiched) tungstoantimonate [Cu 2 Na 4 (α-SbW 9 O 33 ) 2 ] 10− . • Ferromagnetic tungstoantimonate
Bis(2,2′-bipyridyl-κ2 N,N′)(carbonato-κ2 O,O′)cobalt(III) bromide trihydrate
Ma, Peng-Tao; Wang, Yu-Xia; Zhang, Guo-Qian; Li, Ming-Xue
2008-01-01
The title complex, [Co(CO3)(C10H8N2)2]Br·3H2O, is isostructural with the chloride analogue. The six-coordinated octahedral [Co(2,2′-bipy)2CO3]+ cation (2,2′-bipy is 2,2′-bipyridyl), bromide ion and water molecules are linked together via O—H⋯Br and O—H⋯O hydrogen bonds, generating a one-dimensional chain. PMID:21200495
Directory of Open Access Journals (Sweden)
Eno A. Ededet
2011-04-01
Full Text Available Two new mixed-ligand complexes of formula [Cu(mal(abpt(H2O].3/2H2O (1 and [Cu2(sq(abpt2].2H2O (2 [mal = malonate, abpt = 4-amino-3,5-di-2-pyridyl-4H-1,2,4 triazole and sq = squarate], have been prepared and characterized by X-ray crystal structure determination and magnetic studies. Complex 1 crystallizes in the monoclinic system, space group C2/c, with a = 14.0086(2 Å, b = 10.0980(2 Å, c = 25.630(4 Å; β = 97.5900(10 o, and Z = 8. Complex 2 crystallizes in the triclinic system, space group P-1 with a = 7.5696(15 Å, b = 8.4697(17 Å, c = 11.049(2 Å; β = 93.00(3o, α = 96.98(3, γ = 90.111(3 and Z = 1. Complex 1 consist of a neutral mononuclear [Cu(mal(abpt(H2O] unit and water molecule of crystallization in a distorted square pyramidal coordination sphere, while complex 2 is viewed as being made up of [Cu(sq(abpt2] units with the squarato ligand bridging the two copper(II cations. Variable temperature magnetic behaviour of the complexes reveals the existence of weak antiferromagnetic interaction for complex 1 and weak ferromagnetic intrachain interaction for complex 2.
Directory of Open Access Journals (Sweden)
Anas Tahli
2016-03-01
Full Text Available The hydrothermal reaction of 4,4′-bis(1,2,4-triazol-4-yl (btr and benzene-1,3,5-tricarboxylic acid (H3btc with Cd(OAc2·2H2O at 125 °C in situ forms 4-amino-1,2,4-triazole (atr from btr, which crystallizes to a mixed-ligand, poly-anionic chain of [Cd2(atr2(µ2-btc2(H2O4]2–. Together with a hexaaquacadmium(II cation and water molecules the anionic coordination-polymeric forms a 3-D supramolecular network of hexaaquacadmium(II-catena-[bis(4-amino-1,2,4-triazoletetraaquabis(benzene-1,3,5-tricarboxylatodicadmate(II] dihydrate, 1-D-{[Cd(H2O6][Cd2(atr2(µ2-btc2(H2O4] 2H2O}n which is based on hydrogen bonds (in part charge-assisted and π–π interactions.
International Nuclear Information System (INIS)
Odin, I.N.; Grin'ko, V.V.; Kozlovskij, V.F.; Safronov, E.V.
2005-01-01
Mutual system PbSe + Ag 2 I 2 = Ag 2 Se + PbI 2 is investigated. It is shown that diagonal Ag 2 Se-PbI 2 is stable. Liquidus surface and isothermal section at 633 K of phase diagram of PbSe-Ag 2 Se-PbI 2 system are built. Transformations directing to crystallization metastable ternary compound forming in PbSe-PbI 2 system and metastable polytype modifications of lead iodide in PbSe-Ag 2 Se-PbI 2 system at 620-685 K are studied. By hardening from molten state (1150-1220 K) new interstitial metastable phases crystallizing in CdCl 2 structural type are obtained in PbSe-Ag 2 Se-PbI 2 and PbSe + CdI 2 = CdSe + PbI 2 systems [ru
Kuramochi, Yusuke; Fukaya, Kyohei; Yoshida, Makoto; Ishida, Hitoshi
2015-07-06
A series of trans-(Cl)-[Ru(L)(CO)2 Cl2 ]-type complexes, in which the ligands L are 2,2'-bipyridyl derivatives with amide groups at the 5,5'-positions, are synthesized. The C-connected amide group bound to the bipyridyl ligand through the carbonyl carbon atom is twisted with respect to the bipyridyl plane, whereas the N-connected amide group is in the plane. DFT calculations reveal that the twisted structure of the C-connected amide group raises the level of the LUMO, which results in a negative shift of the first reduction potential (Ep ) of the ruthenium complex. The catalytic abilities for CO2 reduction are evaluated in photoreactions (λ>400 nm) with the ruthenium complexes (the catalyst), [Ru(bpy)3 ](2+) (bpy=2,2'-bipyridine; the photosensitizer), and 1-benzyl-1,4-dihydronicotinamide (the electron donor) in CO2 -saturated N,N-dimethylacetamide/water. The logarithm of the turnover frequency increases by shifting Ep a negative value until it reaches the reduction potential of the photosensitizer. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Corbey, Jordan F; Farnaby, Joy H; Bates, Jefferson E; Ziller, Joseph W; Furche, Filipp; Evans, William J
2012-07-16
The effect of the neutral donor ligand, L, on the Ln(2)N(2) core in the (N═N)(2-) complexes, [A(2)(L)Ln](2)(μ-η(2):η(2)-N(2)) (Ln = Sc, Y, lanthanide; A = monoanion; L = neutral ligand), is unknown since all of the crystallographically characterized examples were obtained with L = tetrahydrofuran (THF). To explore variation in L, displacement reactions between {[(Me(3)Si)(2)N](2)(THF)Y}(2)(μ-η(2):η(2)-N(2)), 1, and benzonitrile, pyridine (py), 4-dimethylaminopyridine (DMAP), triphenylphosphine oxide, and trimethylamine N-oxide were investigated. THF is displaced by all of these ligands to form {[(Me(3)Si)(2)N](2)(L)Y}(2)(μ-η(2):η(2)-N(2)) complexes (L = PhCN, 2; py, 3; DMAP, 4; Ph(3)PO, 5; Me(3)NO, 6) that were fully characterized by analytical, spectroscopic, density functional theory, and X-ray crystallographic methods. The crystal structures of the Y(2)N(2) cores in 2-5 are similar to that in 1 with N-N bond distances between 1.255(3) Å and 1.274(3) Å, but X-ray analysis of the N-N distance in 6 shows it to be shorter: 1.198(3) Å.
N-(2-Methylphenyl-1,2-benzoselenazol-3(2H-one
Directory of Open Access Journals (Sweden)
Xu Zhu
2013-10-01
Full Text Available In the title Ebselen [systematic name: (2-phenyl-1,2-benzoisoselenazol-3-(2H-one] analogue, C14H11NOSe, the benzisoselenazolyl moiety (r.m.s. deviation = 0.0209 Å is nearly perpendicular to the N-arenyl ring, making a dihedral angle of 78.15 (11°. In the crystal, molecules are linked by C—H...O and Se...O interactions into chains along the c-axis direction. The Se...O distance [2.733 (3 Å] is longer than that in Ebselen (2.571 (3 Å].
Energy Technology Data Exchange (ETDEWEB)
Chumakov, Yu. M. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Paholnitcaia, A. Yu. [State University of Moldova (Moldova, Republic of); Petrenko, P. A. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Tsapkov, V. I., E-mail: vtsapkov@gmail.com [State University of Moldova (Moldova, Republic of); Poirier, D. [Centre Hospitalier Universitaire de Quebec (Canada); Gulea, A. P. [State University of Moldova (Moldova, Republic of)
2015-01-15
Two crystal modifications of nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper (I and II) and two modifications of chloro-(2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) copper (III and IV) have been synthesized and studied by X-ray diffraction. In structures I and II, the copper atoms coordinate a monodeprotonated molecule of the organic ligand, nitrate ions, and a water molecule. In crystals of I, the complexes are monomeric, whereas complexes II are linked via nitrate ions to form polymeric chains. In both structures the coordination polyhedron of the copper atom can be described as a distorted tetragonal bipyramid—(4 + 1 + 1) in I and (4 + 2) in II. These coordination polyherdra have different compositions. In structures III and IV, the metal atoms coordinate a monodeprotonated (2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazole molecule and chloride ions. In III the complex-forming ion has square-planar coordination geometry, whereas structure IV consists of centrosymmetric dimers with two bridging chlorine atoms. It was found that nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper possesses antitumor activity.
Fabrication of ThO2, UO2, and PuO2-UO2 pellets
International Nuclear Information System (INIS)
Rasmussen, D.E.; Jentzen, W.R.; McCord, R.B.
1978-01-01
Fabrication of ThO pellets for EBR-II irradiation testing and fabrication of UO 2 and PuO 2 -UO 2 pellets for United Kingdom Prototype Fast Reactor (PFR) irradiation testing is discussed. Effect of process parameters on density and microstructure of pellets fabricated by the cold press and sinter technique is reviewed
Low-temperature specific heat of single-crystal Bi2CaSr2Cu2O8 and Tl2Ca2Ba2Cu3O10
Urbach, J. S.; Mitzi, D. B.; Kapitulnik, A.; Wei, J. Y. T.; Morris, D. E.
1989-06-01
We report specific-heat measurements from 2 to 15 K on single crystals of Bi2CaSr2Cu2O8 and Tl2Ca2Ba2Cu3O10 We find low-temperature deviations from the Debye law that can be attributed to spin-glass behavior of a small concentration of isolated impurity copper moments. At higher temperatures, we observe contributions to the specific heat that can be attributed to a soft-phonon mode, possibly associated with the superstructure in the Bi-O and Tl-O layers. From our single-crystal data, we conclude that the thallium- and bismuth-based copper oxide superconductors show no measurable linear term in the specific heat [γ(0)<=1 mJ/mole K2].
Optical anisotropy of Bi2Sr2CaCu2O8
Kim, J. H.; Bozovic, I.; Mitzi, D. B.; Kapitulnik, A.; Harris, J. S., Jr.
1990-04-01
The optical anisotropy of Bi2Sr2CaCu2O8 in the 0.08-0.5-eV region is investigated by polarized reflectance measurements on single crystals. A very large anisotropy is found in this spectral region. The in-plane reflectance exhibits metallic behavior, while the c-axis reflectance exhibits insulatorlike behavior. This result is consistent with the large anisotropy found in the resistivity of Bi2Sr2CaCu2O8. Our spectroscopic data suggest that Bi2Sr2CaCu2O8 is a quasi-two-dimensional metal similar to La2-xSrxCuO4.
Bis(2,2′-bipyridyl-κ2N,N′(sulfato-κ2O,O′cobalt(II ethane-1,2-diol monosolvate
Directory of Open Access Journals (Sweden)
Lin Chen
2011-01-01
Full Text Available The title compound, [Co(SO4(C10H8N22]·C2H6O2, has the Co2+ ion in a distorted octahedral CoN4O2 coordination geometry. A twofold rotation axis passes through the Co and S atoms, and through the mid-point of the C—C bond of the ethanediol molecule. In the crystal, the [CoSO4(C10H8N22] and C2H6O2 units are held together by a pair of O—H...O hydrogen bonds.
The vibration-rotation-tunneling levels of N2-H2O and N2-D2O
Wang, Xiao-Gang; Carrington, Tucker
2015-07-01
In this paper, we report vibration-rotation-tunneling levels of the van der Waals clusters N2-H2O and N2-D2O computed from an ab initio potential energy surface. The only dynamical approximation is that the monomers are rigid. We use a symmetry adapted Lanczos algorithm and an uncoupled product basis set. The pattern of the cluster's levels is complicated by splittings caused by H-H exchange tunneling (larger splitting) and N-N exchange tunneling (smaller splitting). An interesting result that emerges from our calculation is that whereas in N2-H2O, the symmetric H-H tunnelling state is below the anti-symmetric H-H tunnelling state for both K = 0 and K = 1, the order is reversed in N2-D2O for K = 1. The only experimental splitting measurements are the D-D exchange tunneling splittings reported by Zhu et al. [J. Chem. Phys. 139, 214309 (2013)] for N2-D2O in the v2 = 1 region of D2O. Due to the inverted order of the split levels, they measure the sum of the K = 0 and K = 1 tunneling splittings, which is in excellent agreement with our calculated result. Other splittings we predict, in particular those of N2-H2O, may guide future experiments.
Interacting spin-1/2 tetrahedral system Cu2Te2O5X2 (X = Cl, Br)
DEFF Research Database (Denmark)
Jensen, Jens
2009-01-01
Magnetic ordering and excitations of Cu2Te2O5Cl2 are analyzed in terms of a tetramerized spin model for the tetrahedral Cu clusters of spin 1/2. The mean-field model is able to account for the main properties of the incommensurable magnetic structure observed by Zaharko et al. [Phys. Rev. B 73......-dimensional fashion. Preliminary model calculations for the Cu2Te2O5Br2 system lead to the same conclusion. Udgivelsesdato: 7. Januar...
[2-(Dimethylaminoethanol-κ2N,O][2-(dimethylaminoethanolato-κ2N,O]iodidocopper(II
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Elena A. Buvaylo
2012-04-01
Full Text Available The title compound, [Cu(C4H10NOI(C4H11NO], was obtained unintentionally as the product of an attempted synthesis of a Cu/Zn mixed-metal complex using zerovalent copper, zinc(II oxide and ammonium iodide in pure 2-(dimethylaminoethanol, in air. The molecular complex has no crystallographically imposed symmetry. The coordination geometry around the metal atom is distorted square-pyramidal. The equatorial coordination around copper involves donor atoms of the bidentate chelating 2-(dimethylaminoethanol ligand and the 2-(dimethylaminoethanolate group, which are mutually trans to each other, with four approximately equal short Cu—O/N bond distances. The axial Cu—I bond is substantially elongated. Intermolecular hydrogen-bonding interactions involving the –OH group of the neutral 2-(dimethylaminoethanol ligand to the O atom of the monodeprotonated 2-(dimethylaminoethanolate group of the molecule related by the n-glide plane, as indicated by the O...O distance of 2.482 (12 Å, form chains of molecules propagating along [101].
Adiabatic burning velocity of H2-O2 mixtures diluted with CO2/N2/Ar
International Nuclear Information System (INIS)
Ratna Kishore, V.; Muchahary, Ringkhang; Ray, Anjan; Ravi, M.R.
2009-01-01
Global warming due to CO 2 emissions has led to the projection of hydrogen as an important fuel for future. A lot of research has been going on to design combustion appliances for hydrogen as fuel. This has necessitated fundamental research on combustion characteristics of hydrogen fuel. In this work, a combination of experiments and computational simulations was employed to study the effects of diluents (CO 2 , N 2 , and Ar) on the laminar burning velocity of premixed hydrogen/oxygen flames using the heat flux method. The experiments were conducted to measure laminar burning velocity for a range of equivalence ratios at atmospheric pressure and temperature (300 K) with reactant mixtures containing varying concentrations of CO 2 , N 2 , and Ar as diluents. Measured burning velocities were compared with computed results obtained from one-dimensional laminar premixed flame code PREMIX with detailed chemical kinetics and good agreement was obtained. The effectiveness of diluents in reduction of laminar burning velocity for a given diluent concentration is in the increasing order of argon, nitrogen, carbon dioxide. This may be due to increased capabilities either to quench the reaction zone by increased specific heat or due to reduced transport rates. The lean and stoichiometric H 2 /O 2 /CO 2 flames with 65% CO 2 dilution exhibited cellular flame structures. Detailed three-dimensional simulation was performed to understand lean H 2 /O 2 /CO 2 cellular flame structure and cell count from computed flame matched well with the experimental cellular flame. (author)
Low-temperature specific heat of single-crystal Bi2CaSr2Cu2O8 and Tl2Ca2Ba2Cu3O10
International Nuclear Information System (INIS)
Urbach, J.S.; Mitzi, D.B.; Kapitulnik, A.; Wei, J.Y.T.; Morris, D.E.; Physics Division, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720)
1989-01-01
We report specific-heat measurements from 2 to 15 K on single crystals of Bi 2 CaSr 2 Cu 2 O 8 and Tl 2 Ca 2 Ba 2 Cu 3 O 10 We find low-temperature deviations from the Debye law that can be attributed to spin-glass behavior of a small concentration of isolated impurity copper moments. At higher temperatures, we observe contributions to the specific heat that can be attributed to a soft-phonon mode, possibly associated with the superstructure in the Bi-O and Tl-O layers. From our single-crystal data, we conclude that the thallium- and bismuth-based copper oxide superconductors show no measurable linear term in the specific heat [γ(0) less than or equal to 1 mJ/mole K 2
The 2s2p 4P0sub(5/2) - 2p24Psup(e)sub(5/2)-transition in O VI
International Nuclear Information System (INIS)
Sjoedin, R.; Pihl, J.; Hallin, R.; Lindskog, J.; Marelius, A.
1976-03-01
The Li-like doubly excited transitions 2s2p 4 P 0 sub(5/2) - 2p 2 4 Psup(e)sub(5/2) in O VI has been studied with the beam-foil technique. Oxygen ion beams with energies between 4.5 to 9 MeV were used. The wavelength of the transition was measured to 944.0+-0.5 A and the lifetime for the upper level 2p 2 4 Psup(e) was measured to be 0.51+-0.04 ns. (Auth.)
Synthesis and structure of Sr{sub 2}Pd{sub 2}In and Sr{sub 2}Pt{sub 2}In
Energy Technology Data Exchange (ETDEWEB)
Muts, I. [Inst. fuer Anorganische und Analytische Chemie, Univ. Muenster (Germany); Inorganic Chemistry Dept., Ivan Franko National Univ. of Lviv (Ukraine); Nilges, T.; Rodewald, U.C.; Poettgen, R. [Inst. fuer Anorganische und Analytische Chemie, Univ. Muenster (Germany); Zaremba, V.I. [Inorganic Chemistry Dept., Ivan Franko National Univ. of Lviv (Ukraine)
2007-12-15
The new intermetallic compounds Sr{sub 2}Pd{sub 2}In and Sr{sub 2}Pt{sub 2}In were synthesized from the elements in sealed tantalum tubes in a water-cooled sample chamber of an induction furnace. Both indides crystallize with the HT-Pr{sub 2}Co{sub 2}Al-type structure: C2/c, a = 1048.7(2), b = 603.5(2), c = 830.6(1) pm. {beta} = 103.68(2) , wR2 = 0.0492, 743 F{sup 2} values for Sr{sub 2}Pd{sub 2}In; a = 1026.8(2), b = 599.0(1), c = 830.3(2) pm, {beta} = 103.17(1) , wR2 = 0.0666, 885 F{sup 2} values for Sr{sub 2}Pt{sub 2}In with 25 variables per refinement. The shortest interatomic distances occur for the Pd-In (Pt-In) and Pd-Pd (Pt-Pt) contacts. The strontium atoms are embedded in complex three-dimensional polyanionic networks of compositions [Pd{sub 2}In] and [Pt{sub 2}In]. (orig.)
Lundgren, Cecilia Vannesjö; Koner, Apurba L; Tinkl, Michael; Pischel, Uwe; Nau, Werner M
2006-03-03
5,7-Di-tert-butyl-3-aryl-3H-benzofuran-2-ones are lactones with potential antioxidant activity, owing to their abstractable benzylic C-H hydrogens. The fluorescence quenching of the azoalkane 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO), an established probe for the hydrogen-donor propensity of chain-breaking antioxidants, was investigated for 16 aryl-substituted benzofuranone derivatives [m,m-(CF3)2, p-CN, m-CN, p-CF3, p-COOCH3, m-CF3, p-Cl, p-F, H, m-CH3, p-CH3, m,p-(CH3)2, p-OCH3, o-CH3, o-CF3, o,m-(CH3)2]. Analysis of the rate data in terms of a linear free energy relationship yielded a reaction constant of rho = +0.35. This implies that n,pi*-excited DBO acts as nucleophilic species. In contrast, hydrogen abstraction of tert-butoxyl radicals from the benzofuranones was accelerated by electron-donating substituents (rho = -0.23), in conformity with the electrophilic character of oxygen-centered alkoxyl radicals. Possible implications for the optimization of the hydrogen-donor propensity of antioxidants through structural variation are discussed.
Human organic cation transporter 2 (hOCT2): Inhibitor studies using S2-hOCT2 cells
International Nuclear Information System (INIS)
Chiba, Shoetsu; Ikawa, Toru; Takeshita, Hiroshi; Kanno, Sanae; Nagai, Tomonori; Takada, Meri; Mukai, Toshiji; Wempe, Michael F.
2013-01-01
Highly expressed in kidney and located on the basolateral membrane, human organic cation transporter 2 (hOCT2) can transport various compounds (i.e. drugs and toxins) into the proximal tubular cell. Using cultured proximal tubule cells stably expressing hOCT2 (i.e. S2-hOCT2 cells), we sought to probe different compound classes (e.g. analgesics, anti-depressants, anti-psychotics, disinfectant, herbicides, insecticides, local anesthetic, muscarinic acetylcholine receptor antagonist, sedatives, steroid hormone, stimulants and toxins) for their ability to inhibit 14 C-TEA uptake, a prototypical OCT2 substrate. Aconitine, amitriptyline, atropine, chlorpyrifos, diazepam, fenitrothion, haloperidol, lidocaine, malathion, mianserin, nicotine and triazolam significantly inhibited 14 C-TEA uptake; IC 50 values were 59.2, 2.4, 2.0, 20.7, 32.3, 13.2, 32.5, 104.6, 71.1, 17.7, 52.8 and 65.5 μM, respectively. In addition, aconitine, amitriptyline, atropine, chlorpyrifos, fenitrothion, haloperidol, lidocaine, and nicotine displayed competitive inhibition with K i values of 145.6, 2.5, 2.4, 24.8, 16.9, 51.6, 86.8 and 57.7 μM, respectively. These in vitro data support the notion that compounds pertaining to a wide variety of different drug classes have the potential to decrease renal clearance of drugs transported via hOCT2. Consequently, these data warrant additional studies to probe hOCT2 and its role to influence drug pharmacokinetics
Web 2.0, Library 2.0, and Librarian 2.0:Preparing for the 2.0 World
Abram, S.
2007-10-01
There is a global conversation going on right now about the next generation of the web. It's happening under the name of Web 2.0. It's the McLuhanesque hot web where true human interaction takes precedence over merely `cool' information delivery and e-mail. It's about putting information into the real context of our users' lives, research, work and play. Concurrently, a group of information professionals are having a conversation about the vision for what Library 2.0 will look like in this Web 2.0 ecosystem. Some are even going so far as to talk about Web 3.0! Web 2.0 is coming fast and it's BIG! What are the skills and competencies that Librarian 2.0 will need? Come and hear an overview of Web 2.0 and a draft vision for Library 2.0 and an opinion about what adaptations we'll need to make to thrive in this future scenario. Let's talk about the Librarian 2.0 in our users' future!
Kilgore, Uriah J; Stewart, Michael P; Helm, Monte L; Dougherty, William G; Kassel, W Scott; DuBois, Mary Rakowski; DuBois, Daniel L; Bullock, R Morris
2011-11-07
A series of [Ni(P(R)(2)N(Ph)(2))(2)(CH(3)CN)](BF(4))(2) complexes containing the cyclic diphosphine ligands [P(R)(2)N(Ph)(2) = 1,5-diaza-3,7-diphosphacyclooctane; R = benzyl (Bn), n-butyl (n-Bu), 2-phenylethyl (PE), 2,4,4-trimethylpentyl (TP), and cyclohexyl (Cy)] have been synthesized and characterized. X-ray diffraction studies reveal that the cations of [Ni(P(Bn)(2)N(Ph)(2))(2)(CH(3)CN)](BF(4))(2) and [Ni(P(n-Bu)(2)N(Ph)(2))(2)(CH(3)CN)](BF(4))(2) have distorted trigonal bipyramidal geometries. The Ni(0) complex [Ni(P(Bn)(2)N(Ph)(2))(2)] was also synthesized and characterized by X-ray diffraction studies and shown to have a distorted tetrahedral structure. These complexes, with the exception of [Ni(P(Cy)(2)N(Ph)(2))(2)(CH(3)CN)](BF(4))(2), all exhibit reversible electron transfer processes for both the Ni(II/I) and Ni(I/0) couples and are electrocatalysts for the production of H(2) in acidic acetonitrile solutions. The heterolytic cleavage of H(2) by [Ni(P(R)(2)N(Ph)(2))(2)(CH(3)CN)](BF(4))(2) complexes in the presence of p-anisidine or p-bromoaniline was used to determine the hydride donor abilities of the corresponding [HNi(P(R)(2)N(Ph)(2))(2)](BF(4)) complexes. However, for the catalysts with the most bulky R groups, the turnover frequencies do not parallel the driving force for elimination of H(2), suggesting that steric interactions between the alkyl substituents on phosphorus and the nitrogen atom of the pendant amines play an important role in determining the overall catalytic rate. © 2011 American Chemical Society
Strain engineering of WS2, WSe2, and WTe2
Amin, Bin; Kaloni, Thaneshwor P.; Schwingenschlö gl, Udo
2014-01-01
We perform first-principles calculations to investigate the structural, electronic, and vibrational properties of WS2, WSe2, and WTe2 monolayers, taking into account the strong spin orbit coupling. A transition from a direct to an indirect band gap
Na7 [Fe2S6 ] , Na2 [FeS2 ] and Na2 [FeSe2 ] : New 'reduced' sodium chalcogenido ferrates
Stüble, Pirmin; Peschke, Simon; Johrendt, Dirk; Röhr, Caroline
2018-02-01
Three new 'reduced' FeII containing sodium chalcogenido ferrates were obtained applying a reductive synthetic route. The mixed-valent sulfido ferrate Na7 [Fe2S6 ] , which forms bar-shaped crystals with metallic greenish luster, was synthesized in pure phase from natural pyrite and elemental sodium at a maximum temperature of 800 °C. Its centrosymmetric triclinic structure (SG P 1 bar , a = 764.15(2), b = 1153.70(2), c = 1272.58(3) pm, α = 62.3325 (7) , β = 72.8345 (8) , γ = 84.6394 (8) ° , Z = 3, R1 = 0.0185) exhibits two crystallographically different [Fe2S6 ] 7 - dimers of edge-sharing [FeS4 ] tetrahedra, with somewhat larger Fe-S distances than in the fully oxidized FeIII dimers of e.g. Na6 [Fe2III S6 ] . In contrast to the localized AFM ordered pure di-ferrates(III), the Curie-Weiss behavior of the magnetic susceptibility proves the rarely observed valence-delocalized S = 9/2 state of the mixed-valent FeIII /FeII dimer. The nearly spin-only value of the magnetic moment combined with the chemical bonding not generally differing from that in pure ferrates(II) and (III), provides a striking argument, that the reduction of the local Fe spin moments observed in all condensed sulfido ferrate moieties is connected with the AFM spin ordering. The two isotypic ferrates(II) Na2 [FeS2 ] and Na2 [FeSe2 ] with chain-like structural units (SG Ibam, a = 643.54(8)/ 660.81(1), b = 1140.2(2)/1190.30(2) c = 562.90(6)/585.59(1) pm, Z = 4, R1 = 0.0372/0.0466) crystallize in the K2 [ZnO2 ] -type structure. Although representing merely further members of the common series of chalcogenido metallates(II) Na2 [MIIQ2 ] , these two new phases, together with Na6 [FeS4 ] and Li2 [FeS2 ] , are the only examples of pure FeII alkali chalcogenido ferrates. The new compounds allow for a general comparison of di- and chain ferrates(II) and (III) and mixed-valent analogs concerning the electronic and magnetic properties (including Heisenberg super-exchange and double-exchange interactions
Syntheses of [5-2H]-uracil, [5-2H]-cytosine, [6-2H]-uracil and [6-2H]-cytosine
International Nuclear Information System (INIS)
Kiritani, Reiko; Asano, Takeyoshi; Fujita, Shin-ichi; Dohmaru, Takaaki; Kawanishi, Tetsuro
1986-01-01
Syntheses of [5- 2 H]-, [6- 2 H]-uracil and [5- 2 H]-, [6- 2 H]-cytosine were investigated. The catalytic reaction of uracil or cytosine with 2 H 2 gas in alkaline media gave rise to [6- 2 H]-compounds almost exclusively. On the other hand, the reaction of 5-bromouracil or 5-bromocytosine with 2 H 2 gas gave rise to a mixture of [5- 2 H]-, [6- 2 H]- and [5- 2 H, 6- 2 H]-compounds depending on the experimental conditions. By controlling the temperature, the pressure of 2 H 2 gas and the amount of catalyst, [5- 2 H]-uracil and [5- 2 H]-cytosine were obtained. The isotopic distribution in each product was measured by 1 H NMR spectroscopy combined with an HPLC method. (author)
Christensen, L. E.; Okumura, M.; Sander, S. P.; Friedl, R. R.; Miller, C. E.; Sloan, J. J.
2004-01-01
Rate coefficients for the reaction HO(sub 2)+ NO(sub 2) + N(sub 2) --> HO(sub 2)NO(sub 2) + N(sub 2) (reaction 1) were measured using simultaneous near-IR and UV spectroscopy from 220 to 298 K and from 45 to 200 Torr.
Synthesis, structure and chemical bonding of CaFe2−xRhxSi2 (x=0, 1.32, and 2) and SrCo2Si2
International Nuclear Information System (INIS)
Hlukhyy, Viktor; Hoffmann, Andrea V.; Fässler, Thomas F.
2013-01-01
The finding of superconductivity in Ba 0.6 K 0.4 Fe 2 As 2 put the attention on the investigation of compounds that crystallize with ThCr 2 Si 2 structure type such as AT 2 X 2 (A=alkali/alkaline earth/rare earth element; T=transition metal and X=element of the 13–15th group). In this context the silicides CaFe 2 Si 2 , CaFe 0.68(6) Rh 1.32(6) Si 2 , CaRh 2 Si 2 and SrCo 2 Si 2 have been synthesized by reaction of the elements under an argon atmosphere. Single crystals were obtained by special heat treatment in welded niobium/tantalum ampoules. The compounds were investigated by means of powder and single crystal X-ray diffraction. All compounds crystallize in the ThCr 2 Si 2 -type structure with space group I4/mmm (No. 139): a=3.939(1) Å, c=10.185(1) Å, R 1 =0.045, 85 F 2 values, 8 variable parameters for CaFe 2 Si 2 ; a=4.0590(2) Å, c=9.9390(8) Å, R 1 =0.030, 90 F 2 values, 10 variable parameters for CaFe 0.68(6) Rh 1.32(6) Si 2 ; a=4.0695(1) Å, c=9.9841(3) Å, R 1 =0.031, 114 F 2 values, 9 variable parameters for CaRh 2 Si 2 ; and a=3.974(1) Å, c=10.395(1) Å, R 1 =0.036, 95 F 2 values, 8 variable parameters for SrCo 2 Si 2 . The structure of SrCo 2 Si 2 contains isolated [Co 2 Si 2 ] 2− 2D-layers in the ab-plane whereas in CaFe 2−x Rh x Si 2 the [T 2 Si 2 ] layers (T=Fe and Rh) are interconnected along the c-axis via Si3Si bonds resulting in a three-dimentional (3D) [T 2 Si 2 ] 2− polyanions and therefore belong to the so-called collapsed form of the ThCr 2 Si 2 -type structure. The SrCo 2 Si 2 and CaRh 2 Si 2 are isoelectronic to the parent 122 iron–pnictide superconductors AeFe 2 As 2 (Ae=alkaline earth elements), whereas CaFe 2 Si 2 is a full substituted variant (As/Si) of CaFe 2 As 2 . The crystal chemistry and chemical bonding in the title compounds are discussed in terms of LMTO band structure calculations and a topological analysis using the Electron Localization Function (ELF). - Graphical abstract: The SrCo 2 Si 2 and CaFe 2−x Rh x Si
Retrieving CO2 from Orbiting Carbon Observatory-2 (OCO-2) Spectra
Crisp, David
2014-06-01
Fossil fuel combustion, deforestation, and other human activities are currently adding almost 40 billion tons of carbon dioxide (CO2) to the atmosphere each year. These emissions have increased by roughly a factor of 3 over the past half century and are still growing by more than 2% per year. The developing world is now responsible for the majority (57%) of these emissions and their rapid growth rates. Precise measurements collected by a global network of surface stations show that these emissions have contributed to a 25% increase in the atmospheric CO2 concentration over the past half century. Surprisingly, comparisons of these measurements with fossil fuel emission inventories indicate that only about half of the CO2 emitted into the atmosphere by human activities stays there. The rest is apparently being absorbed by natural CO2 "sinks" at the Earth's surface. Measurements of the pH of the ocean indicate that it absorbs roughly one quarter of these emissions. The remainder has been attributed to the land biosphere, but the identity and location of the land sinks is still unknown. In addition, the fraction of the anthropogenic CO2 absorbed by these natural sinks has varied dramatically from year to year, but has remained near 1/2 on decadal time scales as the emissions have steadily increased. Uncertainties in the nature, location, and processes controlling these natural sink largely preclude reliable predictions of future atmospheric CO2 buildup rates. The existing greenhouse gas monitoring network can accurately track CO2 changes on hemispheric to global scales, but does not have the resolution or coverage needed to quantify emission sources on regional scales or to identify the natural sinks responsible for absorbing CO2. One way to improve the measurement density is to retrieve precise, spatially-resolved estimates of the column-averaged CO2 dry air mole fraction, XCO2, from satellites. Surface-weighted estimates of XCO2 can be retrieved from measurements of
Cation interdiffusion in the UO2 - (U, Pu)O2 and UO2 - PuO2 systems
International Nuclear Information System (INIS)
Leme, D.G.
1985-01-01
The interdiffusion of U and Pu ions in UO sub(2 +- x) - (U sub(0,83) Pu sub(0,17))O sub(2 + - x) and UO sub(2 + - x) -PuO sub(2 - x) sintered pellets and UO sub(2 +- x) -(U sub(0,82) Pu sub(0,18))O sub(2 + - x) single crystals has been studied as a function of the oxygen potential ΔG sup(-) (O 2 ) or the stoichiometric ratio O/M. The diffusion profiles of UO 2 /(U,Pu)O 2 and UO 2 /PuO 2 couples of different O/M ratios have been measured using high resolution α-spectrometer and microprobe. Thermal annealing of the specimens was performed in controlled atmospheres using either CO-CO 2 gas mixtures for constant O/M ratios or purified argon. The interdiffusion profiles have been analysed by means of the Boltzmann-Matano and Hall methods. The interdiffusion coefficient D sus(approx.) increases with increasing Pu content in sintered pellets (up to 17 wt. %PuO 2 ) showing a strong dependence of D sup(approx.) on the O/M ratio. The micropobe results show that the interdiffusion along grain boundaries is the main diffusion mechanism in the pellets. Experiments have also been carried out in single cristals to measure just the bulk-interdiffusion and avoiding effects due to grain boundaries. A marked dependence of D sup(approx.) on O/M ratio or on oxygen potential ΔG sup(-) (O 2 ), similar to the dependence already reported for self diffusion by means of radioactive tracers, has also been observed. (Author) [pt
Directory of Open Access Journals (Sweden)
Songwuit Chanthee
2016-05-01
Full Text Available The crystal structures of the building block tetramethylammonium (2,2′-bipyridine-κ2N,N′tetracyanidoferrate(III trihydrate, [N(CH34][Fe(CN4(C10H8N2]·3H2O, (I, and a new two-dimensional cyanide-bridged bimetallic coordination polymer, poly[[(2,2′-bipyridine-κ2N,N′di-μ2-cyanido-dicyanido(μ-ethylenediamine-κ2N:N′(ethylenediamine-κ2N,N′cadmium(IIiron(II] monohydrate], [CdFe(CN4(C10H8N2(C2H8N22]·H2O, (II, are reported. In the crystal of (I, pairs of [Fe(2,2′-bipy(CN4]− units (2,2′-bipy is 2,2′-bipyridine are linked together through π–π stacking between the pyridyl rings of the 2,2′-bipy ligands to form a graphite-like structure parallel to the ab plane. The three independent water molecules are hydrogen-bonded alternately with each other, forming a ladder chain structure with R44(8 and R66(12 graph-set ring motifs, while the disordered [N(CH34]+ cations lie above and below the water chains, and the packing is stabilized by weak C—H...O hydrogen bonds. The water chains are further linked with adjacent sheets into a three-dimensional network via O—H...O hydrogen bonds involving the lattice water molecules and the N atoms of terminal cyanide groups of the [Fe(2,2′-bipy(CN4]− building blocks, forming an R44(12 ring motif. Compound (II features a two-dimensional {[Fe(2,2′-bipy(CN4Cd(en2]}n layer structure (en is ethylenediamine extending parallel to (010 and constructed from {[Fe(2,2′-bipy(CN4Cd(en]}n chains interlinked by bridging en ligands at the Cd atoms. Classical O—H...N and N—H...O hydrogen bonds involving the lattice water molecule and N atoms of terminal cyanide groups and the N—H groups of the en ligands are observed within the layers. The layers are further connected via π–π stacking interactions between adjacent pyridine rings of the 2,2′-bipy ligands, completing a three-dimensional supramolecular structure.
Warad, Ismail; Musameh, Sharif; Badran, Ismail; Nassar, Nashaat N.; Brandao, Paula; Tavares, Carlos Jose; Barakat, Assem
2017-11-01
In this study, two dicationic asymmetrical diamine/copper(II) nitrate salt complexes of the general formula trans-[CuII(NN‧)2.H2O](NO3)2 were successfully synthesized using N,N-dimethylethylenediamine and N,N-diethylethylenediamine as asymmetrical diamine ligands. The structure of complex 2 was identified by X-ray single crystal diffraction analysis confirming that the bidentate ligand N,N-dimethylethylenediamine forms a penta-coordinated complex with an H2O molecule located around the copper(II) ion in a trans configuration. It was found that the metal centre is coordinated in a distorted square pyramidal fashion with a τ value of 0.274. The desired complexes were fully characterized using, MS, UV-Vis, CV, FTIR, TG/DTA, and Hirshfeld surface computational analysis. High level theoretical calculations were also performed in order to investigate the complexes structure, conformers, vibrational frequencies, and their excited states.
Benis, E. P.; Zouros, T. J. M.
2016-12-01
New results are presented on the ratio {R}m={σ }{T2p}( {}4P)/{σ }{T2p}({}2P) concerning the production cross sections of Li-like 1s2s2p quartet and doublet P states formed in energetic ion-atom collisions by single 2p electron transfer to the metastable 1s2s {}3S component of the He-like ion beam. Spin statistics predict a value of R m = 2 independent of the collision system in disagreement with most reported measurements of {R}m≃ 1{--}9. A new experimental approach is presented for the evaluation of R m having some practical advantages over earlier approaches. It also allows for the determination of the separate contributions of ground- and metastable-state beam components to the measured spectra. Applying our technique to zero-degree Auger projectile spectra from 4.5 MeV {{{B}}}3+ (Benis et al 2002 Phys. Rev. A 65 064701) and 25.3 MeV {{{F}}}7+ (Zamkov et al 2002 Phys. Rev. A 65 062706) mixed state (1{s}2 {}1S,1s2s {}3S) He-like ion collisions with H2 targets, we report new values of {R}m=3.5+/- 0.4 for boron and {R}m=1.8+/- 0.3 for fluorine. In addition, the ratios of {}2D/{}2P and {{}2P}+/{{}2P}- populations from either the metastable and/or ground state beam component, also relevant to this analysis, are evaluated and compared to previously reported results for carbon collisions on helium (Strohschein et al 2008 Phys. Rev. A 77 022706) including a critical comparison to theory.
Energy Technology Data Exchange (ETDEWEB)
Popova, T B; Berdyukova, V A; Khutsistova, F M [Kalmytskij Gosudarstvennyj Univ., Ehlista (USSR) Rostovskij-na-Donu Gosudarstvennyj Univ., Rostov-na-Donu (USSR)
1990-02-01
Sr(NO{sub 2}){sub 2}-Sr(OH){sub 2}-H{sub 2}O system was investigated by the methods of solubility, density, viscosity, electric conductivity and refractometry. It was established that its compoments form the compound 4Sr(NO{sub 2}){sub 2}xSr(OH){sub 2}x8H{sub 2}O. The compound was separated from solution; its density, decomposition temperature were determined; IR spectra and X-ray patterns of prepared and initial compounds were obtained.
Systems of Ba(PO3)2-Sr(Pu3)2, Cd(PO3)2-Ca(PO3)2
International Nuclear Information System (INIS)
Tokman, I.A.; Bukhalova, G.A.
1977-01-01
Phase diagrams of the Ba(PO 3 ) 2 -Sr(PO 3 ) 2 and Cd(PO 3 ) 2 -Ca(PO 3 ) 2 systems have been studied and plotted by the methods of differential-thermal analysis (DTA), visual-polythermal, X-ray phase and infrared spectroscopy. The Ba(PO 3 ) 2 -Sr(PO 3 ) 2 system is of the eutectic type. In the binary system Cd(PO 3 ) 2 -Ca(PO 3 ) 2 the existence of a continuous series of solid solutions with a minimum at 858 deg C and 27.5 mol.% Ca(PO 3 ) 2 has been established
Synthesis, structure, optical, photoluminescence and magnetic properties of K2[Co(C2O4)2(H2O)2]·4H2O
Narsimhulu, M.; Hussain, K. A.
2018-06-01
The synthesis, crystal structure, optical, photoluminescence and magnetic behaviour of potassium bis(oxalato)cobaltate(II)tertrahydrate{K2[Co(C2O4)2(H2O)2]·4H2O} are described. The compound was grown at room temperature from mixture of aqueous solutions by slow evaporation method. The X-ray crystallographic data showed that the compound belongs to the monoclinic crystal system with P21/n space group and Z = 4. The UV-visible diffuse absorbance spectra exhibited bands at 253, 285 and 541 nm in the visible and ultraviolet regions. The optical band gap of the compound was estimated as 3.4 eV. At room temperature, an intense photoluminescence was observed from this material around 392 nm when it excited at 254 nm. The variable temperature dc magnetic susceptibility measurements exposed paramagnetic behaviour at high temperatures and antiferromagnetic ordering at low temperatures.
Koten, G. van; Brandts, J.A.M.; Boersma, J.; Spek, A.L.
1999-01-01
The synthesis and characterisation is reported of new, five-coordinate molybdenum(VI) bisimidoaryl complexes [Mo(NAr)2(O-N)(R)] [Ar = C6H3(iPr)2-2,6; O-N = 2-pyridyldiphenylmethoxide (a), 2-pyridyldimethylmethoxide (b), 8-quinolinolate (c); R = Cl, Me, CH2SiMe3] and the corresponding bisalkoxide (a,
Genistein and Glyceollin Effects on ABCC2 (MRP2 and ABCG2 (BCRP in Caco-2 Cells
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Chandler Schexnayder
2015-12-01
Full Text Available The goal of the present study was to determine the effects of glyceollins on intestinal ABCC2 (ATP Binding Cassette C2, multidrug resistance protein 2, MRP2 and ABCG2 (ATP Binding Cassette G2, breast cancer resistance protein, BCRP function using the Caco-2 cell intestinal epithelial cell model. Glyceollins are soy-derived phytoestrogens that demonstrate anti-proliferative activity in several sources of cancer cells. 5 (and 6-carboxy-2′,7′-dichloroflourescein (CDF was used as a prototypical MRP2 substrate; whereas BODIPY-prazosin provided an indication of BCRP function. Comparison studies were conducted with genistein. Glyceollins were shown to inhibit MRP2-mediated CDF transport, with activity similar to the MRP2 inhibitor, MK-571. They also demonstrated concentration-dependent inhibition BCRP-mediated efflux of BODIPY-prazosin, with a potency similar to that of the recognized BCRP inhibitor, Ko143. In contrast, genistein did not appear to alter MRP2 activity and even provided a modest increase in BCRP efflux of BODIPY-prazosin. In particular, glyceollin inhibition of these two important intestinal efflux transporters suggests the potential for glyceollin to alter the absorption of other phytochemicals with which it might be co-administered as a dietary supplement, as well as alteration of the absorption of pharmaceuticals that may be administered concomitantly.
International Nuclear Information System (INIS)
Seguatni, A.; Fakhfakh, M.; Smiri, L.S.; Gressier, P.; Boucher, F.; Jouini, N.
2012-01-01
A new inorganic-organic compound [Cu(O 2 C–CH 2 –CO 2 H) 2 ·2H 2 O] ([Cumal]) was hydrothermally synthesized and characterized by IR spectroscopy, thermal analysis and single crystal X-ray diffraction. [Cumal] is the first three-dimensional compound existing in the system Cu(II)–malonic acid–H 2 O. Its framework is built up through carboxyl bridged copper where CuO 6 octahedra are elongated with an almost D 4h symmetry (4+2) due to the Jahn–Teller effect. The magnetic properties were studied by measuring its magnetic susceptibility in the temperature range of 2–300 K indicating the existence of weak ferromagnetic interactions. The electronic structure of [Cumal] was calculated within the density functional theory (DFT) framework. Structural features are well reproduced using DFT structural optimizations and the optical spectra, calculated within the dielectric formalism, explain very well the light blue colour of the compound. It is shown that a GGA+U approach with a U eff value of about 6 eV is necessary for a better correlation with the experiment. - Graphical abstract: [Cu(O 2 C–CH 2 –CO 2 H) 2 ·2H 2 O]: the first 3D hybrid organic–inorganic compound built up carboxyl groups. The network presents a diamond-like structure achieved via carboxyl. Highlights: ► A new organic–inorganic material with an unprecedented topology is synthesized. ► Crystallographic structure is determined using single crystal X-ray diffraction. ► Electronic structure is obtained from DFT, GGA+U calculation. ► Framework can be described as formed from CuC 4 tetrahedron sharing four corners. ► This structure can be classified as an extended diamond structure.
Superconductivity and anomalous normal state in the CePd2Si2/CeNi2Ge2 system
International Nuclear Information System (INIS)
Grosche, F.M.; Lister, S.J.S.; Carter, F.V.; Saxena, S.S.; Haselwimmer, R.K.W.; Mathur, N.D.; Julian, S.R.; Lonzarich, G.G.
1997-01-01
The unconventional nonmagnetic metal CeNi 2 Ge 2 is characterised at ambient pressure by temperature dependences of the specific heat and of the resistivity which deviate strongly from standard Fermi-liquid predictions and are reminiscent of the behaviour observed in its sibling system CePd 2 Si 2 above the critical pressure at which magnetic order is suppressed. We have explored the CePd 2 Si 2 /CeNi 2 Ge 2 phase diagram in a series of resistivity measurements under high hydrostatic pressure, p. At p>15 kbar, a new superconducting transition appears below 220 mK in CeNi 2 Ge 2 and shifts to higher temperatures with increasing pressure, reaching ∝400 mK at p∝26 kbar. (orig.)
Krumrine, Jennifer Rebecca
This dissertation is concerned in part with the construction of accurate pairwise potentials, based on reliable ab initio potential energy surfaces (PES's), which are fully anisotropic in the sense that multiple PES's are accessible to systems with orientational electronic properties. We have carried out several investigations of B (2s 22p 2Po) with spherical ligands: (1)an investigation of the electronic spectrum of the BAr2 complex and (2)two related studies of the equilibrium properties and spectral simulation of B embedded in solid pH 2. Our investigations suggest that it cannot be assumed that nuclear motion in an open-shell system occurs on a single PES. The 2s2p2 2 D modeled theoretically; the excited potential energy surfaces of the five-fold degenerate B(2s2p2 2D) state within the ternary complex are computed using a pairwise-additive model. A collaborative path integral molecular dynamics investigation of the equilibrium properties of boron trapped in solid para-hydrogen (pH2) and a path integral Monte Carlo spectral simulation. Using fully anisotropic pair potentials, coupling of the electronic and nuclear degrees of freedom is observed, and is found to be an essential feature in understanding the behavior and determining the energy of the impure solid, especially in highly anisotropic matrices. We employ the variational Monte Carlo method to further study the behavior of ground state B embedded in solid pH2. When a boron atom exists in a substitutional site in a lattice, the anisotropic distortion of the local lattice plays a minimal role in the energetics. However, when a nearest neighbor vacancy is present along with the boron impurity, two phenomena are found to influence the behavior of the impure quantum solid: (1)orientation of the 2p orbital to minimize the energy of the impurity and (2)distortion of the local lattice structure to promote an energetically favorable nuclear configuration. This research was supported by the Joint Program for Atomic
(4-Chloroacetanilido-κ2N,Obis[2-(pyridin-2-ylphenyl-κ2C1,N]iridium(III
Directory of Open Access Journals (Sweden)
Lijun Sun
2013-02-01
Full Text Available In the neutral mononuclear iridium(III title compound, [Ir(C8H7ClNO(C11H8N2], the IrIII atom adopts an octahedral geometry, and is coordinated by two 2-phenylpyridyl ligands and one anionic 4-chloroacetanilide ligand. The 2-phenylpyridyl ligands are arranged in a cis-C,C′ and cis-N,N′ fashion. Each 2-phenylpyridyl ligand forms a five-membered ring with the IrIII atom. The 2-phenylpyridyl planes are perpendicular to each other [dihedral angle = 89.9 (1°]. The Ir—C and Ir—N bond lengths are comparable to those reported for related iridium(III 2-phenylpyridyl complexes. The remaining two coordination sites are occupied by the amidate N and O atoms, which form a four-membered ring with the iridium atom (Ir—N—C—O. The amidate plane is nearly perpendicular to both 2-phenylpyridyl ligands [dihedral angles = 87.8 (2 and 88.3 (2°].
Deelman, B.J; Wierda, F.; Meetsma, A.; Teuben, J.H
1995-01-01
The activation of esters and amides by (Cp(2)*LnH)(2) [Ln = Y (1a), Ln = La (1b), Cp*=C(5)Me] and Cp(2)*Y(2-C(6)H(4)CH(2)NMe(2)) (2) is described. Compounds 1a and 1b react with ethyl acetate to form Cp(2)*YOEt (3a) and Cp(2)*LaOEt (30). With 1a and ethyl benzoate a 1:1 mixture of 3a and
International Nuclear Information System (INIS)
Tashiro, Masahi; Tsuzuki, Hirohisa; Mataka, Shuntaro; Goto, Hideyuki; Ogasahara, Shoji
1990-01-01
Using Kolbe electrolysis of methyl hydrogen [ 2 H 0 ]-, [ 2 H 2 ]-, and [ 2 H 4 ]-succinates as a key reaction, adipic [2,2- 2 H 2 ]-, [2,3- 2 H 2 ]-, [2,2,3,3- 2 H 4 ]-, [2,3,4,5- 2 H 4 ]-, [2,3,5,5- 2 H 4 ]-, [2,2,3,3,5,5- 2 H 6 ]-, and [2,2,3,3,4,4,5,5- 2 H 8 ]-acids were prepared in high deuterium contents. (author)
Synthesis and Crystal Structure of an Unprecedented Supramolecular Complex[Co(μ2-ClO4)2(H2O)2]·2MA
Institute of Scientific and Technical Information of China (English)
XU,Jing; BAI,Zhengshuai; SUN,Weiyin
2009-01-01
A new supramolecular framework[Co(μ2-C104)2(H2O)2]·2MA(1)[MA=melamine(C3H6N6)]has been syn-thesized by a hydrothermal method.Interestingly,there ale inorganic and organic building blocks with two different supramolecular synthons:(a)2D(4,4)network constructed by infinite inorganic 1D chains through interchain hy-drogen bonding interactions;(b)1D zigzag organic chains formed by hydrogen bonds, which further stack up through,ππ-interactions between the two adjacent MA molecules.The entire structure of 1 is a 3D supramolecular framework resulting from the presence of abundant hydrogen bonds between infinite[CO(μ2-C1O4)2(H2O)2]n chains and zigzag MA chains in different sheets.1 gives a nice example of supramolecular framework based on non-covalent interactions including hydrogen bonding and π-π interactions.
Bis(di-2-pyridylamine-κ2N2,N2'platinum(II dibromide monohydrate
Directory of Open Access Journals (Sweden)
Kwang Ha
2012-04-01
Full Text Available The asymmetric unit of the title compound, [Pt(C10H9N32]Br2·H2O, contains two crystallographically independent half-molecules of the cationic PtII complex, two Br− anions and a lattice water molecule; an inversion centre is located at the centroid of each complex. Each PtII ion is four-coordinated in an essentially square-planar environment by four pyridine N atoms derived from the two chelating di-2-pyridylamine (dpa ligands, and the PtN4 unit is exactly planar. The chelate ring formed by the dpa ligand displays a boat conformation, with dihedral angles between the pyridine rings of 35.9 (2 and 41.0 (2°. The complex cations, Br− anions and solvent water molecules are linked by O—H...Br, N—H...Br, C—H...O and C—H...Br hydrogen bonds, forming a three-dimensional network.
On osp(2|2) conformal field theories
International Nuclear Information System (INIS)
Ding Xiangmao; Gould, Mark D; Mewton, Courtney J; Zhang Yaozhong
2003-01-01
We study the conformal field theories corresponding to current superalgebras osp(2|2) (1) k and osp(2|2) (2) k . We construct the free field realizations, screen currents and primary fields of these current superalgebras at general level k. All the results for osp(2|2) (2) k are new, and the results for the primary fields of osp(2|2) (1) k also seem to be new. Our results are expected to be useful in the supersymmetric approach to Gaussian disordered systems such as the random bond Ising model and the Dirac model
Zhang, Dong; Johnsson, Mats
2008-01-01
Single crystals of dizinc tellurium dibromide trioxide, Zn2(TeO3)Br2, were synthesized via a transport reaction in sealed evacuated silica tubes. The compound has a layered crystal structure in which the building units are [ZnO4Br] distorted square pyramids, [ZnO2Br2] distorted tetrahedra, and [TeO3 E] tetrahedra (E being the 5s 2 lone pair of Te4+) joined through sharing of edges and corners to form layers of no net charge. Bromine atoms and tellurium lone pairs protrude from the surfaces of each layer towards adjacent layers. This new compound Zn2(TeO3)Br2 is isostructural with the synthetic compounds Zn2(TeO3)Cl2, CuZn(TeO3)2, Co2(TeO3)Br2 and the mineral sophiite, Zn2(SeO3)Cl2. PMID:21202162
Grishanov, B I; Alabau-Pons, M; Angal-Kalinin, Deepa; Appleby, R; Araki, S; Bailey, I; Bambade, P; Bane, Karl Leopold Freitag; Barlow, R; Blair, G A; Bolzon, B; Boorman, G; Bosco, A; Brachmann, A; Braun, Hans Heinrich; Burrows, P N; Carter, J; Choi, J; Christian, Glenn B; Clarke, C; Dabiri-Khah, A; Dadoun, O; Danagulyan, S; Delerue, N; Dixit, S; Driouichi, C; Elsen E; Gao, J; Geffroy, N; Gronberg, J; Hartin, Anthony F; Hayano, H; Higashi, Y; Himel, T; Honda, Y; Howell, D; Huang, J Y; Iwashita, Y; Jenner, L; Jones, J; Jones, R; Jérémie, A; Kalinin, A; Kanazawa, K; Kang, H S; Karyotakis, Yu; Kim, E S; Kim, S; Komamiya, S; Kourevlev, German Yu; Kubo, K; Kumada, M; Kume, T; Kuriki, M; Kuroda, S; Liu, W; Logatchev, P V; Lyapin, A; Malton, S; Markiewicz, T W; Masuzawa, M; Mihara, T; Miller, D J; Molloy, S; Mtingwa, S; Naito, T; Nan-Phinney, Y; Napoly, O; Nelson, J; Okugi, T; Payet, J; Pei, G X; Pivi, M T F; Podgorny, F; Price, M; Raubenheimer, T O; Reichold, A; Ross, M; Sanuki, T; Schulte, Daniel; Seryi, R A; Solyak, N; Soo Ko In; Spencer, C M; Suehara, T; Sugahara, R; Takahashi, T; Takashi-Boogert, S; Tauchi, T; Telnov, Valery I; Tenenbaum, P G; Terunuma, N; Toge, N; Torrence, E; Urakawa, J; Urner, D; Vogel, V; Walker, N; Wang, J Q; Wendt, M; White, G; Wing, M; Wolski, A; Woodley, M; Yamaoka, H; Yokoya, K; Zimmermann, Frank
2006-01-01
For achieving the high luminosity required at the International Linear Collider (ILC), it is critical to focus the beams to nanometer size with the ILC Beam Delivery System (BDS), and to maintain the beam collision with a nanometer-scale stability. To establish the technologies associated with this ultra-high precision beam handling, it has been proposed to implement an ILC-like final focus optics in an extension of the existing extraction beamline of ATF at KEK. The ATF is considered to be the best platform for this exercise, since it provides an adequate ultra-low emittance electron beam in a manner dedicated to the development of ILC. The two major goals for this facility, called ATF2, are : (A) Achievement of a 37 nm beam size, and (B) control of beam position down to 2 nm level. The scientific justification for the ATF2 project and its technical design have been described in Volume 1 of the ATF2 Proposal [1]. We present here Volume 2 of the ATF2 Proposal, in which we present specifics of the construction...
Poly[mu2-(N-hydroxypyridine-2-carboxamidine)-mu2-nitrato-silver(I)].
Cui, Ai-Li; Han, Peng; Yang, Hui-Juan; Wang, Ru-Ji; Kou, Hui-Zhong
2007-12-01
In the title complex, [Ag(NO3)(C6H7N3O)]n or [Ag(NO3)(pyaoxH2)] (pyaoxH2 is N-hydroxypyridine-2-carboxamidine), the Ag+ ion is bridged by the pyaoxH2 ligands and nitrate anions, giving rise to a two-dimensional molecular structure. Each pyaoxH2 ligand coordinates to two Ag+ ions using its pyridyl and carboxamidine N atoms, and the OH and the NH2 groups are uncoordinated. Each nitrate anion uses two O atoms to coordinate to two Ag+ ions. The Ag...Ag separation via the pyaoxH2 bridge is 2.869 (1) A, markedly shorter than that of 6.452 (1) A via the nitrate bridge. The two-dimensional structure is fishscale-like, and can be described as pyaoxH2-bridged Ag2 nodes that are further linked by nitrate anions. Hydrogen bonding between the amidine groups and the nitrate O atoms connects adjacent layers into a three-dimensional network.
Directory of Open Access Journals (Sweden)
Il-Ju Ko
2017-01-01
Full Text Available The framework of [RMI]2[Co2(BTC2(H2O2] (RMI = 1-alkyl-3-methylimidazolium, alkyl; ethyl (EMI; propyl (PMI; butyl (BMI, which has uniquely occurred in ionothermal reactions of metal salts and H3BTC (1,3,5-benzenetricarboxylic acid, an organic ligand, reappeared in this work. Ionothermal reaction of cobalt acetate and H3BTC with [BMI]Br ionic liquid as the reaction medium yielded the novel coordination polymer [BMI]2[Co2(BTC2(H2O2] (compound B2. Similar ionothermal reactions with different [EMI]Br and [PMI]Br as the reaction media have been previously reported to produce [EMI]2[Co3(BTC2(OAc2] (compound A1 and [PMI]2[Co2(BTC2(H2O2] (compound B1, respectively. In contrast with the trinuclear secondary building unit of A1, the framework structure of B1 and B2 consists of dinuclear secondary building units in common, but with subtle distinction posed by the different size of the incorporated cations. These structural differences amidst the frameworks showed interesting aspects, including guest and void volume, and were used to explain the chemical trend observed in the system. Moreover, the physicochemical properties of the newly synthesized compound have been briefly discussed.
H2O2: A Dynamic Neuromodulator
Rice, Margaret E.
2012-01-01
Increasing evidence implicates hydrogen peroxide (H2O2) as an intra- and intercellular signaling molecule that can influence processes from embryonic development to cell death. Most research has focused on relatively slow signaling, on the order of minutes to days, via second messenger cascades. However, H2O2 can also mediate subsecond signaling via ion channel activation. This rapid signaling has been examined most thoroughly in the nigrostriatal dopamine (DA) pathway, which plays a key role in facilitating movement mediated by the basal ganglia. In DA neurons of the substantia nigra, endogenously generated H2O2 activates ATP-sensitive K+ (KATP) channels that inhibit DA neuron firing. In the striatum, H2O2 generated downstream from glutamatergic AMPA receptor activation in medium spiny neurons acts as a diffusible messenger that inhibits axonal DA release, also via KATP channels. The source of dynamically generated H2O2 is mitochondrial respiration; thus, H2O2 provides a novel link between activity and metabolism via KATP channels. Additional targets of H2O2 include transient receptor potential (TRP) channels. In contrast to the inhibitory effect of H2O2 acting via KATP channels, TRP channel activation is excitatory. This review describes emerging roles of H2O2 as a signaling agent in the nigrostriatal pathway and other basal ganglia neurons. PMID:21666063
EDEMA, JJH; LIBBERS, R; RIDDER, A; KELLOGG, RM; SPEK, AL; Libbers, Rob
1994-01-01
Reaction of 2,6-lutidine with 2 equivalents of (n)BuLi followed by addition of 2-adamantanone affords the doubly functionalized 2,6-di-(2-oxy(2-adamantylidine))ethylpyridine (2a). Reaction of 2a with Me(2)SiCl(2) gives the pseudo-pentacoordinate
Bis{bis[1-methoxy-2-(2-methoxyethoxyethane-κ3O,O′,O′′]sodium} 1,1,2,2-tetraphenylethane-1,2-diide
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Mikhail E. Minyaev
2014-07-01
Full Text Available Crystals of the title salt, [Na(C6H14O32]2(C26H20, were grown from a tetrahydrofuran/diglyme/Et2O solvent mixture [diglyme is 1-methoxy-2-(2-methoxyethoxyethane]. The cations and dianion are separated in the crystal structure, unlike in the other three structurally characterized dialkali metal tetraphenylethylene salts. The asymmetric unit contains one [Na(diglyme2]+ cation and one half of the [Ph2CCPh2]2− dianion. The latter lies on a twofold rotation axis. C—C bond-length redistribution displays that excessive electron density of the dianion is predominantly located at the C atoms of a former double bond and at all eight ortho positions. The studied crystal was a twin, with the ratio of two major components being 0.2143 (9:0.7857 (9. The twin operation is a twofold rotation around the a axis.
Magnetoresistance in Co/2D MoS2/Co and Ni/2D MoS2/Ni junctions.
Zhang, Han; Ye, Meng; Wang, Yangyang; Quhe, Ruge; Pan, Yuanyuan; Guo, Ying; Song, Zhigang; Yang, Jinbo; Guo, Wanlin; Lu, Jing
2016-06-28
Semiconducting single-layer (SL) and few-layer MoS2 have a flat surface, free of dangling bonds. Using density functional theory coupled with non-equilibrium Green's function method, we investigate the spin-polarized transport properties of Co/2D MoS2/Co and Ni/2D MoS2/Ni junctions with MoS2 layer numbers of N = 1, 3, and 5. Well-defined interfaces are formed between MoS2 and metal electrodes. The junctions with a SL MoS2 spacer are almost metallic owing to the strong coupling between MoS2 and the ferromagnets, while those are tunneling with a few layer MoS2 spacer. Both large magnetoresistance and tunneling magnetoresistance are found when fcc or hcp Co is used as an electrode. Therefore, flat single- and few-layer MoS2 can serve as an effective nonmagnetic spacer in a magnetoresistance or tunneling magnetoresistance device with a well-defined interface.
NO and H2O2 contribute to SO2 toxicity via Ca2+ signaling in Vicia faba guard cells.
Yi, Min; Bai, Heli; Xue, Meizhao; Yi, Huilan
2017-04-01
NO and H 2 O 2 have been implicated as important signals in biotic and abiotic stress responses of plants to the environment. Previously, we have shown that SO 2 exposure increased the levels of NO and H 2 O 2 in plant cells. We hypothesize that, as signaling molecules, NO and H 2 O 2 mediate SO 2 -caused toxicity. In this paper, we show that SO 2 hydrates caused guard cell death in a concentration-dependent manner in the concentration range of 0.25 to 6 mmol L -1 , which was associated with elevation of intracellular NO, H 2 O 2 , and Ca 2+ levels in Vicia faba guard cells. NO donor SNP enhanced SO 2 toxicity, while NO scavenger c-PTIO and NO synthesis inhibitors L-NAME and tungstate significantly prevented SO 2 toxicity. ROS scavenger ascorbic acid (AsA) and catalase (CAT), Ca 2+ chelating agent EGTA, and Ca 2+ channel inhibitor LaCl 3 also markedly blocked SO 2 toxicity. In addition, both c-PTIO and AsA could completely block SO 2 -induced elevation of intracellular Ca 2+ level. Moreover, c-PTIO efficiently blocked SO 2 -induced H 2 O 2 elevation, and AsA significantly blocked SO 2 -induced NO elevation. These results indicate that extra NO and H 2 O 2 are produced and accumulated in SO 2 -treated guard cells, which further activate Ca 2+ signaling to mediate SO 2 toxicity. Our findings suggest that both NO and H 2 O 2 contribute to SO 2 toxicity via Ca 2+ signaling.
Directory of Open Access Journals (Sweden)
Mats Johnsson
2008-05-01
Full Text Available Single crystals of dizinc tellurium dibromide trioxide, Zn2(TeO3Br2, were synthesized via a transport reaction in sealed evacuated silica tubes. The compound has a layered crystal structure in which the building units are [ZnO4Br] distorted square pyramids, [ZnO2Br2] distorted tetrahedra, and [TeO3E] tetrahedra (E being the 5s2 lone pair of Te4+ joined through sharing of edges and corners to form layers of no net charge. Bromine atoms and tellurium lone pairs protrude from the surfaces of each layer towards adjacent layers. This new compound Zn2(TeO3Br2 is isostructural with the synthetic compounds Zn2(TeO3Cl2, CuZn(TeO32, Co2(TeO3Br2 and the mineral sophiite, Zn2(SeO3Cl2.
Torii, Sigeru; Liu, Ping; Bhuvaneswari, Narayanaswamy; Amatore, Christian; Jutand, Anny
1996-05-03
Iodine-assisted chemical and electrochemical asymmetric dihydroxylation of various olefins in I(2)-K(2)CO(3)-K(2)OsO(2)(OH)(4) and I(2)-K(3)PO(4)/K(2)HPO(4)-K(2)OsO(2)(OH)(4) systems with Sharpless' ligand provided the optically active glycols in excellent isolated yields and high enantiomeric excesses. Iodine (I(2)) was used stoichiometrically for the chemical dihydroxylation, and good results were obtained with nonconjugated olefins in contrast to the case of potassium ferricyanide as a co-oxidant. The potentiality of I(2) as a co-oxidant under stoichiometric conditions has been proven to be effective as an oxidizing mediator in electrolysis systems. Iodine-assisted asymmetric electro-dihydroxylation of olefins in either a t-BuOH/H(2)O(1/1)-K(2)CO(3)/(DHQD)(2)PHAL-(Pt) or t-BuOH/H(2)O(1/1)-K(3)PO(4)/K(2)HPO(4)/(DHQD)(2)PHAL-(Pt) system in the presence of potassium osmate in an undivided cell was investigated in detail. Irrespective of the substitution pattern, all the olefins afforded the diols in high yields and excellent enantiomeric excesses. A plausible mechanism is discussed on the basis of cyclic voltammograms as well as experimental observations.
Directory of Open Access Journals (Sweden)
Lahcen El Ammari
2010-12-01
Full Text Available The title compound, dinickel(II strontium bis[orthophosphate(V] dihydrate, was obtained under hydrothermal conditions. The crystal structure consists of linear chains ∞1[NiO2/2(OH22/2O2/1] of edge-sharing NiO6 octahedra (overline{1} symmetry running parallel to [010]. Adjacent chains are linked to each other through PO4 tetrahedra (m symmetry and arranged in such a way to build layers parallel to (001. The three-dimensional framework is accomplished by stacking of adjacent layers that are held together by SrO8 polyhedra (2/m symmetry. Two types of O—H...O hydrogen bonds involving the water molecule are present, viz. one very strong hydrogen bond perpendicular to the layers and weak trifurcated hydrogen bonds parallel to the layers.
DEFF Research Database (Denmark)
Tarabanis, Konstantinos; Efthimios, Tambouris; Zotou, Maria
2016-01-01
etc. The report also presents the OD-PBL design pathway, which is a further development of the OD-PBL methodological recommendations presented in the D2.1. This design pathway aims to guide educators when designing learning processes that aim to teach OD by utilizing the PBL learning strategy......The work carried out resulted in the description of the LA field and in the presentation of a total of 18 LA tools that can analyse educational data that can be utilized in the project to support multiple PBL aspects, such as feedback, reflection, self-driven learning, collaboration, application....... The pathway consists of 6 main steps, i.e. Analysis, Gathering of inputs, Design, Development, Implementation and Reflection. Each step provides guidelines on how to plan an OD course and learning processes, and combines all previous project results from D1.1, D1.2, D1.3 and D2.1. Finally, the report presents...
Homoleptic diphosphacyclobutadiene complexes [M(η(4)-P2C2R2)2]x- (M = Fe, Co; x = 0, 1).
Wolf, Robert; Ehlers, Andreas W; Khusniyarov, Marat M; Hartl, František; de Bruin, Bas; Long, Gary J; Grandjean, Fernande; Schappacher, Falko M; Pöttgen, Rainer; Slootweg, J Chris; Lutz, Martin; Spek, Anthony L; Lammertsma, Koop
2010-12-27
The preparation and comprehensive characterization of a series of homoleptic sandwich complexes containing diphosphacyclobutadiene ligands are reported. Compounds [K([18]crown-6)(thf)(2)][Fe(η(4)-P(2)C(2)tBu(2))(2)] (K1), [K([18]crown-6)(thf)(2)][Co(η(4)-P(2)C(2)tBu(2))(2)] (K2), and [K([18]crown-6)(thf)(2)][Co(η(4)-P(2)C(2)Ad(2))(2)] (K3, Ad = adamantyl) were obtained from reactions of [K([18]crown-6)(thf)(2)][M(η(4)-C(14)H(10))(2)] (M = Fe, Co) with tBuC[triple bond]P (1, 2), or with AdC[triple bond]P (3). Neutral sandwiches [M(η(4)-P(2)C(2)tBu(2))(2)] (4: M = Fe 5: M = Co) were obtained by oxidizing 1 and 2 with [Cp(2)Fe]PF(6). Cyclic voltammetry and spectro-electrochemistry indicate that the two [M(η(4)-P(2)C(2)tBu(2))(2)](-)/[M(η(4)-P(2)C(2)tBu(2))(2)] moieties can be reversibly interconverted by one electron oxidation and reduction, respectively. Complexes 1-5 were characterized by multinuclear NMR, EPR (1 and 5), UV/Vis, and Mössbauer spectroscopies (1 and 4), mass spectrometry (4 and 5), and microanalysis (1-3). The molecular structures of 1-5 were determined by using X-ray crystallography. Essentially D(2d)-symmetric structures were found for all five complexes, which show the two 1,3-diphosphacyclobutadiene rings in a staggered orientation. Density functional theory calculations revealed the importance of covalent metal-ligand π bonding in 1-5. Possible oxidation state assignments for the metal ions are discussed.
Properties of spin-1/2 triangular-lattice antiferromagnets CuY2Ge2O8 and CuLa2Ge2O8
Cho, Hwanbeom; Kratochvílová, Marie; Sim, Hasung; Choi, Ki-Young; Kim, Choong Hyun; Paulsen, Carley; Avdeev, Maxim; Peets, Darren C.; Jo, Younghun; Lee, Sanghyun; Noda, Yukio; Lawler, Michael J.; Park, Je-Geun
2017-04-01
We found new two-dimensional (2D) quantum (S =1 /2 ) antiferromagnetic systems: Cu R E2G e2O8 (R E =Y and La). According to our analysis of high-resolution x-ray and neutron diffraction experiments, the Cu network of Cu R E2G e2O8 (R E =Y and La) exhibits a 2D triangular lattice linked via weak bonds along the perpendicular b axis. Our bulk characterizations from 0.08 to 400 K show that they undergo a long-range order at 0.51(1) and 1.09(4) K for the Y and La systems, respectively. Interestingly, they also exhibit field induced phase transitions. For theoretical understanding, we carried out the density functional theory (DFT) band calculations to find that they are typical charge-transfer-type insulators with a gap of Eg≅2 eV . Taken together, our observations make Cu R E2G e2O8 (R E =Y and La) additional examples of low-dimensional quantum spin triangular antiferromagnets with the low-temperature magnetic ordering.
Wildner, M.; Marinova, D.; Stoilova, D.
2016-02-01
The solubility in the three-component systems Cs2SO4-CuSO4-H2O and Cs2SeO4-CuSeO4-H2O have been studied at 25 °C. The experimental results show that double salts, Cs2Cu(SO4)2·6H2O and Cs2Cu(SeO4)2·4H2O, crystallize from the ternary solutions within large concentration ranges. Crystals of Cs2Cu(SeO4)2·6H2O were synthesized at somewhat lower temperatures (7-8 °C). The thermal dehydration of the title compounds was studied by TG, DTA and DSC methods and the respective dehydration schemes are proposed. The calculated enthalpies of dehydration (ΔHdeh) have values of: 434.2 kJ mol-1 (Cs2Cu(SeO4)2·6H2O), 280.9 kJ mol-1 (Cs2Cu(SeO4)2·4H2O), and 420.2 kJ mol-1 (the phase transition of Cs2Cu(SO4)2·6H2O into Cs2Cu(SO4)2·H2O). The crystal structure of Cs2Cu(SeO4)2ṡ6H2O was determined from single crystal X-ray diffraction data. It belongs to the group of Tutton salts, crystallizing isotypic to the respective sulfate in a monoclinic structure which is characterized by isolated Cu(H2O)6 octahedra and SeO4 tetrahedra, interlinked by hydrogen bonds and [9]-coordinated Cs+ cations. Infrared spectra of the cesium copper compounds are presented and discussed with respect to both the normal modes of the tetrahedral ions and the water molecules. The analysis of the infrared spectra of the double compounds reveals that the distortion of the selenate tetrahedra in Cs2Cu(SeO4)2·4H2O is stronger than those in Cs2Cu(SeO4)2·6H2O in agreement with the structural data. Matrix-infrared spectroscopy was applied to confirm this claim - Δν3 for SO4 2 - ions matrix-isolated in Cs2Cu(SeO4)2·6H2O has a value of 35 cm-1 and that of the same ions included in Cs2Cu(SeO4)2·4H2O - 84 cm-1. This spectroscopic finding is due to the formation of strong covalent bands Cu-OSO3 on one hand, and on the other to the stronger deformation of the host SeO4 2 - tetrahedra in Cs2Cu(SeO4)2·4H2O as compared to those in Cs2Cu(SeO4)2·6H2O. The strength of the hydrogen bonds as deduced from the
The phenomenon of phase separated in Na2O-B2O3-SiO2, Na2O-SiO2-P2O5 glasses
International Nuclear Information System (INIS)
Procyk, B.; Bieniarz, P.; Plichta, E.; Pudelek, B.; Kucinski, G.; Staniewicz-Brudnik, B.
1997-01-01
During the thermal treatment, the phenomenon of phase separation has been observed in the some glasses. The glass has became opaque, due to the opalescence of phase separated. Investigations of the phenomenon of phase separation were conducted using the basic systems: Na 2 O-B 2 O 3 -SiO 2 , Na 2 O-SiO 2 -P 2 O 5 and theirs modifications. The occurrence of binodal and spinodal phase decomposition was observed by TEM. The phase separation inhomogeneities have drop-like character and with higher concentration shows a tendency for coalescence. The influence of the chemical composition, temperature and time on the phenomenon of phase separation in the investigated glasses has been defined. (author)
2,2′-Dimethyl-1,1′-[2,2-bis(bromomethylpropane-1,3-diyl]dibenzimidazole hemihydrate
Directory of Open Access Journals (Sweden)
Yong-Sheng Yan
2012-03-01
Full Text Available The title compound, C21H22Br2N4·0.5H2O, contains two benzimidazole groups which may provide two potential coordination nodes for the construction of metal–organic frameworks. The mean planes of the two imidazole groups are almost perpendicular, with a dihedral angle of 83.05 (2°, and adjacent molecules are linked into a one-dimensional chain by π–π stacking interactions between imidazole groups of different molecules [centroid-to-centroid distances of 3.834 (2 and 3.522 (2 Å].
International Nuclear Information System (INIS)
Gao Xizhen
1997-05-01
The new research on the reaction of H 2 O 2 with Fe 2+ has been studied. Through determining the electric potential, pH and O 2 release during the mutual titration between H 2 O 2 solution and FeSO 4 solution, deduced the chemical equations of H 2 O 2 (without free hydroxyl) oxidizing FeSO 4 and Fe 2 (SO 4 ) 3 oxidizing H 2 O 2 . The research results show that acid is a catalytic agent for decomposing H 2 O 2 to be O 2 and H 2 O besides iron ions. The maximum oxidizing potential is up to about 640 mV. While using H 2 O 2 as an oxidant in uranium heap leaching and in-situ leaching, controlling electric potential can be regarded as a method for adjusting the feeding speed of H 2 O 2 to keep the electric potential below 500 mV, thus the H 2 O 2 decomposition can be reduced. (13 refs., 3 tabs., 1 fig.)
36 CFR 2.2 - Wildlife protection.
2010-07-01
... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Wildlife protection. 2.2... PROTECTION, PUBLIC USE AND RECREATION § 2.2 Wildlife protection. (a) The following are prohibited: (1) The taking of wildlife, except by authorized hunting and trapping activities conducted in accordance with...
Sensitivity Analysis for CO2 Retrieval using GOSAT-2 FTS-2 Simulator
Kamei, Akihide; Yoshida, Yukio; Dupuy, Eric; Yokota, Yasuhiro; Hiraki, Kaduo; Matsunaga, Tsuneo
2015-04-01
The Greenhouse Gases Observing Satellite (GOSAT), launched in 2009, is the world's first satellite dedicated to global greenhouse gases observation. GOSAT-2, the successor mission to GOSAT, is scheduled for launch in early 2018. The Fourier Transform Spectrometer-2 (FTS-2) is the primary sensor onboard GOSAT-2. It observes infrared light reflected and emitted from the Earth's surface and atmosphere. The FTS-2 obtains high resolution spectra using three bands in the near to short-wavelength infrared (SWIR) region and two bands in the thermal infrared (TIR) region. Column amounts and vertical profiles of carbon dioxide (CO2) and methane (CH4) are retrieved from the radiance spectra obtained with the SWIR and TIR bands, respectively. Further, compared to the FTS onboard the GOSAT, the FTS-2 has several improvements: 1) added spectral coverage in the SWIR region for carbon monoxide (CO) retrieval, 2) increased signal-to-noise ratio (SNR) for all bands, 3) extended range of along-track pointing angles for sunglint observations, 4) intelligent pointing to avoid cloud contamination. Since 2012, we have been developing a simulator software to simulate the spectral radiance data that will be acquired by the GOSAT-2 FTS-2. The purpose of the GOSAT-2 FTS-2 simulator is to analyze/optimize data with respect to the sensor specification, the parameters for Level 1 processing, and the improvement of the Level 2 algorithms. The GOSAT-2 FTS-2 simulator includes the six components: 1) overall control, 2) sensor carrying platform, 3) spectral radiance calculation, 4) Fourier Transform module, 5) Level 1B (L1B) processing, and 6) L1B data output. It has been installed on the GOSAT Research Computation Facility (GOSAT RCF), which is a high-performance and energy-efficient supercomputer. More realistic and faster simulations have been made possible by the improvement of the details of sensor characteristics, the sophistication of the data processing and algorithms, the addition of the
Magnetic structure and phase transitions of Co1-xMnxCl2.2H2O and Co1-xMnxCl2.2D2O
International Nuclear Information System (INIS)
Brueckel, T.; Lippert, M.; Kubo, H.; Zenmyo, K.; Mayer, H.M.; Pfeiffer, F.; Hohlwein, D.; Krimmel, A.
1995-01-01
We present neutron diffraction results of the magnetic structure, phase transitions and magnetic short-range order of Co 1-x Mn x Cl 2 .2H 2 O/D 2 O single crystals. For samples in an intermediate composition range, where a spin glass phase exists, we found the coexistence of spin glass and long-range antiferromagnetic order. ((orig.))
ESR of Ag2+ ions in S2F2 crystal
International Nuclear Information System (INIS)
Zaripov, M.M.; Ulanov, V.A.; Falin, M.L.
1989-01-01
Experimental data on investigation of bivalent silver ions in S 2 F 2 crystals are presented. Due to the investigation of the grown crystals it is determined that centres of univalent silver ore formed in SrF 2 during crystal growth. X-ray irradiation at room temperature results in the transition of these centres in bivalent staes. Investigation of temperature dependence of ESR spectra type has allowed to make the conclusion about the presence of Jahn-Teller dynamic effect. Analysis of experimental data allows to develop a model of the investigated paramagnetic complex in S 2 F 2 crystal where Ag 2* ion has coordination polyhedron in the form of eight F - ion cube distorted by C 3 3 axis
Thermal expansion of ThO2-2 wt% UO2 by HT-XRD
International Nuclear Information System (INIS)
Tyagi, A.K.; Mathews, M.D.
2000-01-01
The linear thermal expansion of polycrystalline ThO 2 -2 wt% UO 2 has been investigated from room temperature to 1473 K in flowing helium atmosphere using high temperature X-ray diffractometry. ThO 2 -2 wt% UO 2 shows a marginally higher linear thermal expansion as compared to pure ThO 2 . The average linear and volume thermal expansion coefficients of ThO 2 -2 wt% UO 2 are found to be α-bar a =9.74x10 -6 K -1 and α-bar v =29.52x10 -6 K -1 (298-1473 K). This study will be useful in designing the nuclear reactor fuel assembly based on ThO 2
Homoleptic Diphosphacyclobutadiene Complexes [M(η4-P2C2R2)2]x- (M=Fe, Co; x=0, 1)
Wolf, Robert; Ehlers, A.W.; Khusniyarov, M.M.; Hartl, F.; de Bruin, B.; Long, G.J.; Grandjean, F.; Schappacher, F.M.; Pöttgen, R.; Slootweg, J.C.; Lutz, M.; Spek, A.L.; Lammertsma, K.
2011-01-01
The preparation and comprehensive characterization of a series of homoleptic sandwich complexes containing diphosphacyclobutadiene ligands are reported. Compounds [K([18]crown-6)ACHTUNGTRENUNG(thf)2][Fe(η4- P2C2tBu2)2] (K1), [K([18]crown-6)- ACHTUNGTRENUNG(thf)2][Co(h4-P2C2tBu2)2] (K2), and
Homoleptic Diphosphacyclobutadiene Complexes [M(η(4)-P2C2R2)(2]x- (M = Fe, Co; x=0, 1)
Wolf, R.; Ehlers, A.W.; Khusniyarov, M.M.; Hartl, F.; de Bruin, B.; Long, G.J.; Grandjean, F.; Schappacher, F.M.; Pöttgen, R.; Slootweg, J.C.; Lutz, M.; Spek, A.L.; Lammertsma, K.
2010-01-01
The preparation and comprehensive characterization of a series of homoleptic sandwich complexes containing diphosphacyclobutadiene ligands are reported. Compounds [K([18]crown-6)(thf)(2)[Fe(η(4)-P(2)C(2)tBu(2))(2)] (K1), [K([18]crown-6)(thf)(2)][Co(η(4)-P(2)C(2)tBu(2))(2)] (K2), and
The 2s1/2 → 2p1/2 + one photon transition in hydrogen and hydrogenlike ions
International Nuclear Information System (INIS)
Kelsey, E.J.
1977-01-01
The 2s 1 / 2 → 2p 1 / 2 + one photon transition rate is calculated and discussed for hydrogen and hydrogenlike ions. It is noted that the induced transition rather than the spontaneous transition is of primary importance since it is the basis of many of the precision Lamb-shift measurements. The lack of a calculation of the transition rate other than a heuristic nonrelativistic derivation which requires a nontrivial assumption motivates the calculation presented here based on the external field approximation to quantum electrodynamics. It is found that the heuristic answer is correct in lowest order. In this derivation we see that the 2s 1 / 2 → 2p 1 / 2 + one photon transition gives an apparent contradiction to the often-stated remark that for the electric dipole matrix element there exist three equivalent representations, the ''length,'' ''velocity,'' and ''acceleration'' forms. The difficulties of an experimental determination of this transition rate using induced transitions in hydrogenlike ions are briefly noted as well as the somewhat different case of heavy muonic atoms where the spontaneous 2s 1 / 2 → 2p 1 / 2 + one photon transition has been observed
Monegan, Jessie D; Bunge, Scott D
2009-04-06
The synthesis and structural characterization of several 1,1,3,3-tetramethylguanidine (H-TMG) solvated magnesium aryloxide complexes are reported. Bu(2)Mg was successfully reacted with H-TMG, HOC(6)H(3)(CMe(3))(2)-2,6 (H-DBP), and either ethanol, a carboxylic acid, or diphenyl phosphate in a 1:1 ratio to yield the corresponding [Mg(mu-L)(DBP)(H-TMG)](2) where L = OCH(2)CH(3) (OEt, 1), O(2)CC(CH(3))(3) (OBc, 2), O(2)C(C(6)H(2)-2,4,6-(CH(3))(3)) (TMBA, 3), or O(2)P(OC(6)H(5))(2) (DPP, 4). Bu(2)Mg was also reacted with two equivalents of H-TMG and HOC(6)H(3)(CMe(3))-2-(CH(3))-6 (BMP) or HO-2,6-Ph(2)C(6)H(3) to yield [Mg(BMP)(2)(H-TMG)(2)] (5) and [Mg(O-2,6-Ph(2)C(6)H(3))(2)(H-TMG)(2)] (6). Compounds 1-6 were characterized by single-crystal X-ray diffraction. Polymerization of l- and rac-lactide with 1 was found to generate polylactide (PLA). A discussion concerning the relevance of compounds 2 - 4 to the structure of Mg-activated phosphatase enzymes is also provided. The bulk powders for all complexes were found to be in agreement with the crystal structures based on elemental analyses, FT-IR spectroscopy, and (1)H, (13)C and (31)P NMR studies.
Fluorescence and afterglow of Ca2Sn2Al2O9:Mn2+
Takemoto, Minoru; Iseki, Takahiro
2018-03-01
By using a polymerized complex method, we synthesized manganese (Mn)-doped Ca2Sn2Al2O9, which exhibits yellow fluorescence and afterglow at room temperature when excited by UV radiation. The material emits a broad, featureless fluorescence band centered at 564 nm, which we attribute to the presence of Mn2+ ions. The afterglow decay is well fit by a power-law function, rather than an exponential function. In addition, thermoluminescence analyses demonstrate that two different types of electron traps form in this material. Based on experimental results, we conclude that the fluorescence and afterglow both result from thermally assisted tunneling, in which trapped electrons are thermally excited to higher-level traps and subsequently tunnel to recombination centers.
Collisional Removal of OH (X (sup 2)Pi, nu=7) by O2, N2, CO2, and N2O
Knutsen, Karen; Dyer, Mark J.; Copeland, Richard A.
1996-01-01
Collisional removal rate constants for the OH (X 2PI, nu = 7) radical are measured for the colliders O2, CO2, and N2O, and an upper limit is established for N2. OH(nu = 4) molecules, generated in a microwave discharge flow cell by the reaction of hydrogen atoms with ozone, are excited to v = 7 by the output of a pulsed infrared laser via direct vibrational overtone excitation. The temporal evolution of the P = 7 population is probed as a function of the collider gas partial pressure by a time-delayed pulsed ultraviolet laser. Fluorescence from the B 21 + state is detected in the visible spectral region.
Photo-Induced Spin State Switching In [Fe(bpp)2](NCS)2·2H2O
International Nuclear Information System (INIS)
Bhattacharjee, Ashis; Goodwin, Harry A.; Guetlich, Philipp
2010-01-01
We present the results of our investigation into the effect of irradiation of green light on the high spin low spin transition behavior of the mononuclear iron(II) compound [Fe(bpp) 2 ](NCS) 2 ·2H 2 O explored with the help of magnetic as well as Moessbauer spectroscopic studies. It has been found that the compound exhibits molecular bistability under irradiation of light due to LIESST effect.
Directory of Open Access Journals (Sweden)
Donnici Claudio Luis
1998-01-01
Full Text Available The preparation of key precursors for many 2,2?-bipyridine derivatives such as 4,4?-dicarboxy- 2,2?-bipyridine (I, 6,6?-dicarboxy-2,2?-bipyridine- acid (II, 4,4?-dinitro-2,2?-bipyridine-N,N-dioxide (III, 6,6?-dicarbothioamide-2,2?-bipyridine (IV and mono-N-oxide-2,2?-bipyridine (VII through more efficient methods is described. The syntheses of the novel ligands 4,4?-dihydroxamic-2,2?-bipyridine (V and 6,6?-dihydroxamic-2,2?-bipyridine (VI are also reported.
International Nuclear Information System (INIS)
Johnson, D.L.
1979-01-01
Relative total scattering cross sections for nH 2 + nH 2 , pH 2 + pH 2 , nD 2 + nD 2 , oD 2 + oD 2 , and HD + HD were measured with inclined nozzle beams derived from nozzle sources and intersecting at 21 0 . Both nozzles could be varied in temperature from 4.2K to 300K to provide the velocity range for the cross sections. The use of a parahydrogen converter allowed the measurement of the pH 2 + pH 2 and oD 2 + oD 2 cross sections. Cross sections for the H 2 + H 2 were measured over a relative velocity range of 200 m/s to 1450 m/s. The nH 2 + nH 2 results show an undulation in the velocity range between 350 m/s and 400 m/s that corresponds to a l = 3 orbiting resonance. Analysis of the pH 2 + pH 2 cross section indicates a l = 4 orbiting resonance near 586 m/s. This resonance has a peak energy of 1.79 meV and a measured energy width of 1.05 meV, both which agree well with theoretical predictions. The D 2 + D 2 cross sections have been measured in the velocity range between 190 m/s and 1000 m/s. No orbiting resonances have been observed, but in the oD 2 + oD 2 cross section a deep minimum between the l = 4 and the l = 5 resonances at low velocities is clearly suggested. Initial measurements of the HD + HD cross section suggests the presence of the l = 4 orbiting resonance near a relative velocity of 300 m/s. The experimental results for each system were normalized to the total cross sections, which were convoluted to account for experimental velocity and angular dispersions. Three different potentials were considered, but a chi-square fit of the data indicates that the Schaefer and Meyer potential, which has been theoretically obtained from first principles, provides the best overall description of the hydrogen systems in the low collisional energy range
Ba{sub 2}Cu{sub 2}Te{sub 2}P{sub 2}O{sub 13}: A new telluro-phosphate with S=1/2 Heisenberg chain
Energy Technology Data Exchange (ETDEWEB)
Xia, Mingjun [Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Shen, Shipeng; Lu, Jun; Sun, Young [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li, R.K., E-mail: rkli@mail.ipc.ac.cn [Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)
2015-10-15
A new telluro-phosphate compound Ba{sub 2}Cu{sub 2}Te{sub 2}P{sub 2}O{sub 13} with S=1/2 Heisenberg chain has been successfully synthesized by solid state reaction and grown by flux method. Single crystal X-ray diffraction reveals that Ba{sub 2}Cu{sub 2}Te{sub 2}P{sub 2}O{sub 13} crystallizes into a monoclinic space group C2/c and cell parameters of a=17.647(3) Å, b=7.255(2) Å, c=9.191(2) Å and β=100.16 (3)°. In the structure of Ba{sub 2}Cu{sub 2}Te{sub 2}P{sub 2}O{sub 13}, one dimensional [CuTePO{sub 7}]{sup 3−} chains are formed by tetrahedral PO{sub 4} and trigonal bi-pyramidal TeO{sub 4} joining square planar CuO{sub 4} groups. Those [CuTePO{sub 7}]{sup 3−} chains are inter-connected by sharing one oxygen atom from the TeO{sub 4} group to form two dimensional layers. Magnetic susceptibility and specific heat measurements confirm that the title compound is a model one dimensional Heisenberg antiferromagnetic chain system. - Graphical abstract: Ba{sub 2}Cu{sub 2}Te{sub 2}P{sub 2}O{sub 13}, containing (CuTePO{sub 7}){sup 3−} chains formed by PO{sub 4} and TeO{sub 4} joining CuO{sub 4} groups, shows typical 1D Heisenberg antiferromagnetic chain model behavior as confirmed by magnetic measurements. - Highlights: • New telluro-phosphate Ba{sub 2}Cu{sub 2}Te{sub 2}P{sub 2}O{sub 13} has been grown. • It features layered structure composed of [CuTePO{sub 7}]{sup 3−} chains and TeO{sub 4} groups. • It shows the Heisenberg antiferromagnetic chain behavior. • It is transparent in the range of 1000–2500 nm with a UV absorption edge of 393 nm.
Zigler, David F; Elvington, Mark C; Heinecke, Julie; Brewer, Karen J
2006-08-21
The anthracene lumiphore was linked to the chelating ligand 2,2'-bipyridine, forming 4-[N-(2-anthryl)carbamoyl]-4'-methyl-2,2'-bipyridine (bpyAnth). Coupling through an amide linkage provides some electronic isolation of the anthracene lumiphore. Electrochemistry suggested little change of the anthracene oxidation whether free (1.35 V) linked to 2,2'-bipyridine as bpyAnth (1.30 V) or appended to Fe(II) (1.29 V). The bpyAnth ligand retained the structured luminescence characteristic of anthracene at 375, 400, 419, and 441 nm. This anthracene emission persists even when bpyAnth is complexed to an Fe(II) center. The complex [Fe(bpyAnth)3]2+ is emissive, in marked contrast to typical polyazine iron(II) complexes. This bpyAnth ligand serves as a luminescently tagged analogue of 2,2'-bipyridine, useful for coordination to a variety of metals.
Bis[2-(2H-benzotriazol-2-yl-4-methylphenolato]palladium(II
Directory of Open Access Journals (Sweden)
Chen-Yen Tsai
2009-06-01
Full Text Available In the title complex, [Pd(C13H10N3O2], the PdII atom is tetracoordinated by two N atoms and two O atoms from two bidentate 2-(2H-benzotriazol-2-yl-4-methylphenolate ligands, forming a square-planar environment. The asymmetric unit contains one half molecule in which the Pd atom lies on a centre of symmetry.
International Nuclear Information System (INIS)
Baker, P.K.; Armstrong, E.M.; Drew, M.G.B.
1988-01-01
The reactions of the highly versatile bis(alkyne) compounds [WI 2 (CO)(NCMe)(η 2 -RC 2 R) 2 ] (R = Me, Ph) with pyridine and related ligands to give neutral and cationic alkyne complexes are reported. The x-ray structure of [WI 2 (CO)(bpy)(η 2 -MeC 2 Me) 2 ][BPh 4 ] was also measured and is reported. 10 references, 1 figure, 6 tables
Domieracki, Krzysztof; Wiśniewski, Piotr; Wochowski, Konrad; Romanova, Tetiana; Hackemer, Alicja; Gorzelniak, Roman; Pikul, Adam; Kaczorowski, Dariusz
2018-05-01
Our on-going search for unconventional superconductors among the ThTE2Ge2 phases (TE is a d-electron transition metal) revealed that ThPd2Ge2, which crystallizes with a body-centered tetragonal ThCr2Si2-type structure, exhibits superconductivity at low temperatures. In this paper, we report on the electrical transport and thermodynamic properties of a polycrystalline sample of this new superconductor, extended down to 50 mK. The experimental data indicates weakly-coupled type-II superconductivity with Tc = 0.63(2) K and μ0Hc2(0) = 32(2) mT.
Synthesis, characterization and antifungal studies of metalloquinolone [Cd2(nal2(phen2(Cl2
Directory of Open Access Journals (Sweden)
A. Debnath
2014-12-01
Full Text Available A novel dinuclear, distorted octahedral complex of nalidixic acid (nal with Cd(II metal ion with the formula [Cd2(Nal2(Phen2(Cl2] has been synthesized in the presence of N-containing heterocyclic ligand, 1,10-phenanthroline (phen. The synthesized metal complex was characterized using CHN analysis, Fourier transformed infra-red, thermo gravimetric analysis, differential scanning chalorimetry, nuclear magnetic resonance, ultra violet-visible and single-crystal X-ray diffraction. The newly synthesized complex shows more pronounced antifungal activity compared with the parent quinolone against four fungi, namely Pythium aphanidermatum, Sclerotinia rolfsii, Rhizoctonia solani and Rhizoctonia bataticola.
2,2-Dimethyl-2,3-dihydro-1H-perimidine
Directory of Open Access Journals (Sweden)
Sarah Maloney
2013-02-01
Full Text Available The title compound, C13H14N2, was obtained from reaction of diaminonaphthalene with acetone. In both independent molecules in the asymmetric unit, the tricyclic perimidine consists of a planar (r.m.s. deviations = 0.0125 and 0.0181 Å naphthalene ring system and an envelope conformation C4N2 ringwith the NCN group hinged with respect to the naphthalene backbone by 36.9 (2 and 41.3 (2° in the two independent molecules. The methyl substituents are arranged approximately axial and equatorial on the apical C atom. In the crystal, one of the N—H groups of one independent molecule is involved in classical N—H...N hydrogen bonding. Short intermolecular (C/N—H...π(arene interactions, near the short T-shaped limit, link molecules in the absence of strong acceptors.
Propane-1,3-diaminium–2-carboxypyridine-6-carboxylate–pyridine-2,6-dicarboxylic acid–water (1/2/2/8
Directory of Open Access Journals (Sweden)
Hossein Aghabozorg
2008-01-01
Full Text Available The title proton-transfer compound, C3H12N22+·2C7H4NO4−·2C7H5NO4·8H2O or (pnH2(pydcH2.2(pydcH2·8H2O, was obtained by the reaction of pyridine-2,6-dicarboxylic acid (pydcH2 and propane-1,3-diamine (pn in aqueous solution. Both neutral and monoanionic forms of the diacid are observed in the crystal structure. The negative charge of two monoanions is balanced by the dicationic propane-1,3-diaminium species. In addition, considerable π–π stacking interactions between the aromatic rings of the (pydcH− and (pydcH2 fragments [with centroid–centroid distances of 3.5108 (11–3.5949 (11 Å] are observed. The most important feature of this crystal structure is the presence of a large number of O—H...O, O—H...N, N—H...O, N—H...N, C—H...O and C—H...N hydrogen bonds, with D...A ranging from 2.445 (2 to 3.485 (3 Å. These interactions as well as ion pairing and π–π stacking connect the various fragments into a supramolecular structure.
Lu, Zhuoyang; Reddy, M. V. V. V. Sekhar; Liu, Jianfang; Kalichava, Ana; Liu, Jiankang; Zhang, Lei; Chen, Fang; Wang, Yun; Holthauzen, Luis Marcelo F.; White, Mark A.; Seshadrinathan, Suchithra; Zhong, Xiaoying; Ren, Gang; Rudenko, Gabby
2016-01-01
Contactin-associated protein-like 2 (CNTNAP2) is a large multidomain neuronal adhesion molecule implicated in a number of neurological disorders, including epilepsy, schizophrenia, autism spectrum disorder, intellectual disability, and language delay. We reveal here by electron microscopy that the architecture of CNTNAP2 is composed of a large, medium, and small lobe that flex with respect to each other. Using epitope labeling and fragments, we assign the F58C, L1, and L2 domains to the large lobe, the FBG and L3 domains to the middle lobe, and the L4 domain to the small lobe of the CNTNAP2 molecular envelope. Our data reveal that CNTNAP2 has a very different architecture compared with neurexin 1α, a fellow member of the neurexin superfamily and a prototype, suggesting that CNTNAP2 uses a different strategy to integrate into the synaptic protein network. We show that the ectodomains of CNTNAP2 and contactin 2 (CNTN2) bind directly and specifically, with low nanomolar affinity. We show further that mutations in CNTNAP2 implicated in autism spectrum disorder are not segregated but are distributed over the whole ectodomain. The molecular shape and dimensions of CNTNAP2 place constraints on how CNTNAP2 integrates in the cleft of axo-glial and neuronal contact sites and how it functions as an organizing and adhesive molecule. PMID:27621318
Diaquabis[2-(2-hydroxyethylpyridine-κ2N,O]cobalt(II dichloride
Directory of Open Access Journals (Sweden)
Hocine Merazig
2013-08-01
Full Text Available In the title salt, [Co(C7H9NO2(H2O2]Cl2, the CoII cation, located on an inversion center, is N,O-chelated by two hydroxyethylpyridine ligands and coordinated by two water molecules in a distorted O4N2 octahedral geometry. In the crystal, the Cl− anions link with the complex cations via O—H...Cl hydrogen bonds, forming a three-dimensional supramolecular architecture. π–π stacking is observed between the pyridine rings of adjacent molecules [centroid–centroid distance = 3.5810 (11 Å].
Rosemary Extracts Upregulate Nrf2, Sestrin2, and MRP2 Protein Level in Human Hepatoma HepG2 Cells
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Xiao-pei Tong
2017-01-01
Full Text Available In the past few decades, the incidence of liver cancer has been rapidly rising across the world. Rosemary is known to possess antioxidant activity and is used as natural antioxidant food preservative. It is proposed to have anticancer activity in treating different tumor models. In this study, we try to explore the impact of rosemary extracts on upregulating the level of Nrf2 and Nrf2-regulatory proteins, Sestrin2 and MRP2 in HepG2 cells, and to speculate its potential mechanism. The anticancer activity of rosemary extract, including its polyphenolic diterpenes carnosic acid and carnosol, was evaluated to understand the potential effect on HepG2 cells. Rosemary extract, carnosic acid, and carnosol induced the expression of Sestrin2 and MRP2 associate with enhancement of Nrf2 protein level in HepG2 cells, in which carnosic acid showed most obvious effect. Although the activation pathway of Nrf2/ARE was not exactly assessed, it can be assumed that the enhancement of expression of Sestrin2 and MRP2 may result from upregulation of Nrf2.
An end-to-end coupled model ROMS-N 2 P 2 Z 2 D 2 -OSMOSE of ...
African Journals Online (AJOL)
An end-to-end coupled model ROMS-N 2 P 2 Z 2 D 2 -OSMOSE of the southern Benguela foodweb: parameterisation, calibration and pattern-oriented validation. ... We also highlight the capacity of this model for tracking indicators at various hierarchical levels. Keywords: individual-based model, model validation, ...
Ab initio study of isomerism of Li2AB2 molecules and Li2AB2+ ions with 16 valent electrons
International Nuclear Information System (INIS)
Charkin, O.P.; Klimenko, N.M.; MakKi, M.L.
2000-01-01
In the framework of MP2(6-31*//HF/6-31G + ZPE(HF/6-31G*) and MP4SDTQ/6-31G*//MP2/6-31G* + ZPE(MP2/6-31G*) approximations ab initio calculations of surfaces of potential energy of molecules of lithium salts of Li 2 AB 2 (Li 2 BeO 2 , L 2 MgO 2 , Li 2 BeS 2 , Li 2 MgS 2 , Li 2 CN 2 , Li 2 SiN 2 , Li 2 CP 2 ) type and ions of Li 2 AB 2 + (Li 2 BO 2 + , Li 2 AlO 2 + , Li 2 BS 2 + , Li 2 AlS 2 + , Li 2 N 3 + , Li 2 PN 2 + , Li 2 P 3 + ) type with 16 valent electrons are done. For oxide and nitride systems global minimum corresponds to symmetric linear structure D ∞h and for their sulfide and phosphorus analogues curved plane or unplane (C 2 ) structure with bond angle φ(LBA)=90-110 Deg are preferable. Equilibrium geometric parameters, relative energies and energies of isomer decomposition, frequencies and IR-intensities of normal vibrations are determined [ru
Rutt, Oliver J; Hill, Timothy L; Gál, Zoltán A; Hayward, Michael A; Clarke, Simon J
2003-12-01
Potassium intercalation into the cation-deficient n = 2 Ruddlesden-Popper oxysulfide Y(2)Ti(2)O(5)S(2) to form KY(2)Ti(2)O(5)S(2) has been carried out by reaction of the oxysulfide with potassium vapor in sealed metal tubes at 400 degrees C, potassium naphthalide in THF at 50 degrees C, or potassium in liquid ammonia at temperatures as low as -78 degrees C. Insertion of potassium is topotactic, and although a site 12-coordinate by oxide ions is vacant in the perovskite-type oxide slabs of the structure, potassium is too large to enter this site via the 4-coordinate window, and instead enters the rock-salt-type sulfide layers of the structure which necessitates a 30% increase in the lattice parameter c normal to the layers. In contrast with one of the sodium intercalates of Y(2)Ti(2)O(5)S(2) (beta-NaY(2)Ti(2)O(5)S(2)) in which sodium occupies a tetrahedral site in the sulfide layers, potassium favors an 8-coordinate site which necessitates a relative translation of adjacent oxide slabs. KY(2)Ti(2)O(5)S(2) is tetragonal: P4/mmm, a = 3.71563(4) A, c = 14.8682(2) A (at 298 K), Z = 1. Although the resistivity (3.4(1) x 10(3) Omega cm) is larger than would be expected for a metal, temperature independent paramagnetism dominates the magnetic susceptibility, and the material is electronically very similar to the analogous sodium intercalate beta-NaY(2)Ti(2)O(5)S(2) which features reduced-titanium-containing oxide layers of very similar geometry and electron count.
International Nuclear Information System (INIS)
Gladkov, V.E.; Zhekhanova, N.B.; Fotiev, A.A.; Viktorov, V.V.; Ivashinnikov, V.T.; Zubov, A.S.
1985-01-01
The effect of titanium and calcium containing additions introduced into the Al 2 O 3 +ZrO 2 melt on the phase composition and temperature ranges of ZrO 2 polymorphous transformation in the material is investigated. It is shown that introducing sponge titanium into the 70Al 2 O 3 +30ZrO 2 prepared composition melt (mass. %) with its subsequent intensive cooling one can conserve upto room temperatures 50-70% of ZrO 2 metastable tetragonal modification and therefore reduce the volume changes causing metal cracking. Calcium oxide doping stabilizes the ZrO 2 cubic modification and reduces α-Al 2 O 3 content due to formation of aluminates
Layered P2-Na 2/3 Co 1/2 Ti 1/2 O 2 as a high-performance cathode material for sodium-ion batteries
Energy Technology Data Exchange (ETDEWEB)
Sabi, Noha; Doubaji, Siham; Hashimoto, Kazuki; Komaba, Shinichi; Amine, Khalil; Solhy, Abderrahim; Manoun, Bouchaib; Bilal, Essaid; Saadoune, Ismael
2017-02-01
Layered oxides are regarded as promising cathode materials for sodium-ion batteries. We present Na2/3Co1/2Ti1/2O2 as a potential new cathode material for sodium-ion batteries. The crystal features and morphology of the pristine powder were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The cathode material is evaluated in galvanostatic charge-discharge and galvanostatic intermittent titration tests, as well as ex-situ X-ray diffraction analysis. Synthesized by a high-temperature solid state reaction, Na2/3Co1/2Ti1/2O2 crystallizes in P2-type structure with P6(3)/mmc space group. The material presents reversible electrochemical behavior and delivers a specific discharge capacity of 100 mAh g(-1) when tested in Na half cells between 2.0 and 4.2 V (vs. Na+/Na), with capacity retention of 98% after 50 cycles. Furthermore, the electrochemical cycling of this titanium-containing material evidenced a reduction of the potential jumps recorded in the NaxCoO2 parent phase, revealing a positive impact of Ti substitution for Co. The ex-situ XRD measurements confirmed the reversibility and stability of the material. No structural changes were observed in the XRD patterns, and the P2-type structure was stable during the charge/discharge process between 2.0 and 4.2 V vs. Na+/Na. These outcomes will contribute to the progress of developing low cost electrode materials for sodium-ion batteries. (C) 2017 Elsevier B.V. All rights reserved.
Measurement of "2"2"6Ra and "2"2"8Ra in Brazilian and Israeli Phosphates
International Nuclear Information System (INIS)
Ferreira, W.; Canella Avelar, A.; Menezes, M.
2014-01-01
Since the 1970s, the IAEA recognizes that phosphoric acid presents an alternate source of uranium, but given the status of both phosphate and uranium markets the potential of recovering uranium from phosphoric acid still marginal. New technologies for the recovery of uranium from phosphoric acid, national and global interests and environment barriers could shape this market in the medium and long-term scenarios. On the other hand, the use of phosphates is the major source of phosphorus in agriculture and livestock. Beyond phosphorus and calcium, phosphate is also source of some hazardous elements, such: arsenic, cadmium, thorium and uranium, including a variety of radioisotopes as well. This radioactivity is sure to be released in the environment, contributing to the background. The risk is not recognized for some of the players in this market, mainly workers who apply phosphate fertilizers in the farmland, in some cases manipulating phosphates with their bare hands, and without any respiratory protection equipment (RPE) as well. This paper deals with the radioactivity from "2"2"6Ra and "2"2"8Ra in four phosphates often used in Brazilian agriculture. Three Brazilian and an Israeli phosphate were analysed and compared with international criteria. The specific activities of "2"2"6Ra (from the uranium decay series) and "2"2"8Ra (from the thorium decay series) were taken into consideration to ensure an adequate risk assessment. Specific activities were determined by high-resolution gamma spectroscopy with germanium detector and Genie® software from Canberra in the Centre of Nuclear Technology Development (CDTN/CNEN). The concentration of "2"2"6Ra was measured using the 186.2 keV energy peak, the concentration of "2"2"8Ra through "2"2"8Ac. The system was calibrated using a set of standard materials from IAEA. The measured samples were crushed and sieved to a grain (98% at least) size as small as 75 μm. Stable mass was achieved grinding, drying at 105°C and mixing
International Nuclear Information System (INIS)
Nemcsok, Denes; Kovacs, Attila; Szecsenyi, Katalin Meszaros; Leovac, Vukadin M.
2006-01-01
In the present paper we report a joint experimental and theoretical study of 3,5-dimethyl-1-thiocarboxamide pyrazole (L) and its complexes Co 2 L 2 Cl 4 , Cu 2 L 2 Cl 4 and Cu 2 L 2 Br 2 . DFT computations were used to model the structural and bonding properties of the title compounds as well as to derive a reliable force field for the normal coordinate analysis of L. The computations indicated the importance of hydrogen bonding interactions in stabilising the global minimum structures on the potential energy surfaces. In contrast to the S-bridged binuclear Cu 2 L 2 Br 2 complex found in the crystal, our computations predicted the formation of (CuLBr) 2 dimers in the isolated state stabilized by very strong (53 kJ/mol) N-H...Br hydrogen bonding interactions. On the basis of FT-IR and FT-Raman experiments and the DFT-derived scaled quantum mechanical force field we carried out a complete normal coordinate analysis of L. The FT-IR spectra of the three complexes were interpreted using the present assignment of L, literature data and computed results
Frazier, Brenda A; Wolczanski, Peter T; Lobkovsky, Emil B; Cundari, Thomas R
2009-03-18
Application of the dipyridylazaallyl ligand (2-py)CHNCH(2-py) (smif) to a series of first-row transition metals afforded (smif)(2)M(n) [n = 0, M = Fe (1), Co (2), Ni (3); n = +1, M = Co (2+)] and {(TMS)(2)NFe}(2)(smif)(2) (4(2)) via metathetical procedures. The Mossbauer spectrum of 1 (S = 0) and TDDFT calculations, including a UV-vis spectral simulation, reveal it to be a covalent, strong-field system with Delta(o) estimated as approximately 18,000 cm(-1) and B approximately 470 cm(-1). (smif)(2)Co (2) has S = 1/2 according to SQUID data at 10 K. DFT calculations suggest that the odd electron is localized in a smif pi* orbital, i.e., smif is redox-active. EPR-silent (smif)(2)Ni (3) has S = 1 (SQUID), and calculations show that the unpaired spins reside in the d(z(2)) and d(x(2))(-y(2)) orbitals. X-ray structural parameters suggest that low-spin d(6) 1 and 2+ are relatively symmetric D(2d) species, but 2 and 3 manifest a distortion in which one smif is canted in the plane perpendicular to the other. (smif)FeN(TMS)(2) (4) is principally monomeric in solution, but reversibly dimerizes (K(eq) approximately 10(-4) M(-1)) via C-C bond formation in the azaallyl backbone to crystallize as {(TMS)(2)NFe}(2)(smif)(2) (4(2)). The azaallyl compounds possess extraordinary UV-vis absorptivities (epsilon approximately 18,000-52,000) at 580 +/- 15 nm and 406(25) nm that have been identified as intraligand bands with C(nb) --> smif pi* character.
Fang, Ming; Lee, David S; Ziller, Joseph W; Doedens, Robert J; Bates, Jefferson E; Furche, Filipp; Evans, William J
2011-03-23
Examination of the Y[N(SiMe(3))(2)](3)/KC(8) reduction system that allowed isolation of the (N(2))(3-) radical has led to the first evidence of Y(2+) in solution. The deep-blue solutions obtained from Y[N(SiMe(3))(2)](3) and KC(8) in THF at -35 °C under argon have EPR spectra containing a doublet at g(iso) = 1.976 with a 110 G hyperfine coupling constant. The solutions react with N(2) to generate (N(2))(2-) and (N(2))(3-) complexes {[(Me(3)Si)(2)N](2)(THF)Y}(2)(μ-η(2):η(2)-N(2)) (1) and {[(Me(3)Si)(2)N](2)(THF)Y}(2)(μ-η(2):η(2)-N(2))[K(THF)(6)] (2), respectively, and demonstrate that the Y[N(SiMe(3))(2)](3)/KC(8) reaction can proceed through an Y(2+) intermediate. The reactivity of (N(2))(3-) radical with proton sources was probed for the first time for comparison with the (N(2))(2-) and (N(2))(4-) chemistry. Complex 2 reacts with [Et(3)NH][BPh(4)] to form {[(Me(3)Si)(2)N](2)(THF)Y}(2)(μ-N(2)H(2)), the first lanthanide (N(2)H(2))(2-) complex derived from dinitrogen, as well as 1 as a byproduct, consistent with radical disproportionation reactivity.
Isotopic effect in the hydration reactions of 2, 2, 2 - trichloro - 1 - arylethanones
International Nuclear Information System (INIS)
Marconi, D.O.M.; Zucco, C.; Tanaka, A.S.; Nome, F.
1985-01-01
The equilibrium constants and rate constants for hydration and de-hydration of 2, 2, 2 - trichloro - 1 - arylethanones in tetrahydrofurane (THF) / H 2 O - D 2 O e THF/H 2 O using the proton inventory technique involved in the transition state are studied. (M.J.C.) [pt
Modulating magnetic characteristics of Pt embedded graphene by gas adsorption (N2, O2, NO2, SO2)
International Nuclear Information System (INIS)
Lee, Youngbin; Lee, Sangho; Hwang, Yubin; Chung, Yong-Chae
2014-01-01
The effect of gas adsorption on the change in magnetic properties of platinum doped graphene (Pt-graphene) system was investigated using first-principles density-functional theory (DFT). Four chemisorbed gas molecules (N 2 , O 2 , NO 2 , SO 2 ) on Pt-graphene each induced a different type of magnetic properties. For N 2 adsorption, there was no spin polarization. However, for the other cases, magnetic properties were altered by occurring spin polarization. O 2 adsorption led to local polarization on the gas molecule, and two types of complete polarization were introduced on Pt-graphene by NO 2 and SO 2 adsorption. Also, in the latter two cases, an interesting difference was found in the spin direction of gas and Pt-graphene. NO 2 adsorption induced the same spin direction on the adsorbate and substrate, while SO 2 adsorption introduced the opposite spin directions. Thus, these differences in magnetic properties of the Pt-graphene according to the type of adsorbed gas molecules are expected to play a vital role in application as gas sensor or spintronic devices.
Diels-Alder Synthesis of endo-cis-N-phenylbicyclo[2.2.2]oct-5-en-2,3-dicarboximide
Baar, Marsha R.; Wustholz, Kristin
2005-01-01
A study investigated the Diels-Alder synthesis of endo-cis-N-phenylbicyclo [2.2.2]oct-5-en-2,3-dicarboximide. The amount of time taken by a reaction between the 1,3-cyclohexadiene and N-phenylmaleimide at room temperature and also whether the desired cycloadduct would precipitate directly from the reaction mixture was examined.
2-[1-(Methylsulfanylnaphtho[2,1-b]furan-2-yl]acetic acid
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Uk Lee
2008-02-01
Full Text Available The title compound, C15H12O3S, was prepared by alkaline hydrolysis of ethyl 2-{1-(methylsulfanylnaphtho[2,1-b]furan-2-yl}acetate. The crystal structure is stabilized by CH2—H...π interactions between the methyl H atoms of the methylsulfanyl substituent and the central benzene ring of the naphthofuran system, and by inversion-related intermolecular O—H...O hydrogen bonds between the carboxyl groups.
2,2'-(Carbono-thio-yldisulfanedi-yl)bis-(2-methyl-propanoic acid).
Moreno-Fuquen, Rodolfo; Grande, Carlos; Advincula, Rigoberto C; Tenorio, Juan C; Ellena, Javier
2013-05-01
The mol-ecular structure of the title compound, C9H14O4S3, exhibits intra-molecular C-H⋯S hydrogen bonds. In the crystal, pairs of O-H⋯O hydrogen bonds lead to the formation of centrosymmetric dimers, which are in turn connected by weak C-H⋯O inter-actions. The combination of these inter-actions generates edge-fused R 2 (2)(8) and R 2 (2)(20) rings running along [211].
Two complexes of Pt(IV) and Au(III) with 2,2'-dipyridylamine and 2,2'-dipyridylaminide ligands.
Chernyshev, Alexander N; Kukushkin, Vadim Yu; Haukka, Matti
2014-12-01
Two noble metal complexes involving ancillary chloride ligands and chelating 2,2'-bipyridylamine (Hdpa) or its deprotonated derivative (dpa), namely [bis(pyridin-2-yl-κN)amine]tetrachloridoplatinum(IV), [PtCl4(C10H9N3)], and [bis(pyridin-2-yl-κN)aminido]dichloridogold(III), [AuCl2(C10H8N3)], are presented and structurally characterized. The metal atom in the former has a slightly distorted octahedral coordination environment, formed by four chloride ligands and two pyridyl N atoms of Hdpa, while the metal atom in the latter has a slightly distorted square-planar coordination environment, formed by two chloride ligands and two pyridyl N atoms of dpa. The difference in conjugation between the pyridine rings in normal and deprotonated 2,2'-dipyridylamine is discussed on the basis of the structural features of these complexes. The influence of weak interactions on the supramolecular structures of the complexes, providing one-dimensional chains of [PtCl4(C10H9N3)] and dimers of [AuCl2(C10H8N3)], are discussed.
Directory of Open Access Journals (Sweden)
В. Судавцова
2012-04-01
Full Text Available Methodology of prognostication of thermodynamics properties of melts is presented from the coordinatesof liquidus of diagram of the state in area of equilibria a hard component is solution, on which energies ofmixing of Gibbs are expected in the double border systems of MgO – Al2O3, MgO – SiO2, MgO – CaF2,Al2O3 – SiO2, Al2O3 - CaF2, SiO2 - CaF2. For the areas of equilibrium there is quasibinary connection(MgAl2O4, Mg2SiO4, Al6Si2O13 – a grout at calculations was used equalization of Hauffe-Wagner. Theobtained data comport with literary
2-Aminopyridinium 2,4-dinitrophenolate
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S. Reena Devi
2016-09-01
Full Text Available The asymmetric unit of the title organic salt, C5H7N2+·C6H3N2O5−, comprises two 2-aminopyridinium cations and two 2,4-dinitrophenolate anions. The cations are protonated at the pyridine N atoms, while the anions are deprotonated at hydroxyl O atoms. In the crystal, bifurcated N—H...O hydrogen bonds generate two R12(6, two R21(6, and one R21(4 ring motifs. Adjacent anions and cations are linked by N—H...O hydrogen bonds into infinite chains along [110]. Weak C—H...O contacts and π–π interactions further link the components, forming a complex three-dimensional supramolecular network.
Substituted 2,2′-bipyridines by nickel-catalysis: 4,4′-di-tert-butyl-2,2′-bipyridine
Buonomo, Joseph A.; Everson, Daniel A.; Weix, Daniel J.
2013-01-01
A simple, ligand-free synthesis of the important bipyridyl ligand 4,4′-di-tert-butyl-2,2′-bipyridine is presented. 5,5′-bis(trifluoromethyl)-2,2′-bipyridine is also synthesized by the same protocol. The syntheses efficiently couple the parent 2-chlorpyridies by a nickel-catalyzed dimerization with manganese powder as the terminal reductant.
Geng, Dongling; Shang, Mengmeng; Zhang, Yang; Lian, Hongzhou; Lin, Jun
2013-11-21
Eu(2+) singly and Eu(2+)/Mn(2+) co-doped Na2SrMg(PO4)2 (NSMP) phosphors have been prepared via a high-temperature solid-state reaction process. Upon UV excitation of 260-360 nm, the NSMP:xEu(2+) phosphors exhibit a violet band located at 399 nm and a blue band centered at 445 nm, which originate from Eu(2+) ions occupying two different crystallographic sites: Eu(2+)(I) and Eu(2+)(II), respectively. Excitation wavelengths longer than 380 nm can selectively excite Eu(2+)(II) to emit blue light. Energy transfer processes in the Eu(2+)(I)-Eu(2+)(II) and Eu(2+)-Mn(2+) pairs have been observed and investigated by luminescence spectra and decay curves. The emission color of as-prepared samples can be tuned by changing the relative concentrations of Eu(2+) and Mn(2+) ions and adjusting the excitation wavelength. Under UV excitation of 323 nm, the absolute quantum yield of NSMP:0.005Eu(2+) is 91%, which is higher than most of the other Eu(2+)-doped phosphors reported previously. The temperature dependent luminescence properties and decay curves (4.3-450 K) of NSMP:Eu(2+) and NSMP:Eu(2+), Mn(2+) phosphors have been studied in detail. Thermal quenching of Eu(2+) has been observed while the emission band of Mn(2+) shows a blue-shift and an abnormal increase of intensity with increasing temperature. The unusual thermal quenching behavior indicates that the NSMP compound can serve as a good lattice host for Mn(2+) ions which can be used as a red-emitting phosphor. Additionally, the lifetimes for Eu(2+)(I) and Eu(2+)(II) increase with increasing temperatures.
The Vaporization of B2O3(l) to B2O3(g) and B2O2(g)
Jacobson, Nathan S.; Myers, Dwight L.
2011-01-01
The vaporization of B2O3 in a reducing environment leads to formation of both B2O3(g) and B2O2(g). While formation of B2O3(g) is well understood, many questions about the formation of B2O2(g) remain. Previous studies using B(s) + B2O3(l) have led to inconsistent thermodynamic data. In this study, it was found that after heating, B(s) and B2O3(l) appear to separate and variations in contact area likely led to the inconsistent vapor pressures of B2O2(g). To circumvent this problem, an activity of boron is fixed with a two-phase mixture of FeB and Fe2B. Both second and third law enthalpies of formation were measured for B2O2(g) and B2O3(g). From these the enthalpies of formation at 298.15 K are calculated to be -479.9 +/- 41.5 kJ/mol for B2O2(g) and -833.4 +/- 13.1 kJ/mol for B2O3(g). Ab initio calculations to determine the enthalpies of formation of B2O2(g) and B2O3(g) were conducted using the W1BD composite method and show good agreement with the experimental values.
Reddy, Kotha Laxma; Reddy, Y Harish Kumar; Kumar, K Ashwini; Vidhisha, S; Satyanarayana, S
2009-03-01
The polypyridyl ligand 7-Nitro dipyrido[3,2-a:2'-3'-c]phenazine (7-Nitro-dppz) and its complexes [Co(bpy)(2)(7-NO(2)-dppz)](3+)(1) (bpy = 2,2'-bipyridine), [Co(dmb)(2)(7-NO(2)-dppz)](3+)(2), (dmb = 4,4'-dimethyl-2,2'-bipyridine), and [Co(phen)(2)(7-NO(2)-dppz)](3+)(3) (phen = 1,10-phenanthroline) were synthesized and characterized by UV/VIS, IR, elemental analysis, (1)H and (13)C-NMR, and mass spectra. The binding properties of the three complexes to CT-DNA were investigated by different spectroscopic methods and viscosity measurements and DNA cleavage assay. The experimental results suggest that these complexes bind to CT-DNA through an intercalative mode. Also, the three complexes promote the photocleavage of plasmid pBR-322 DNA under irradiation. Toxicological effects of the selected complexes were estimated with different microorganisms.
Yin, Jiuren; Wu, Bozhao; Wang, Yanggang; Li, Zhimi; Yao, Yuanpeng; Jiang, Yong; Ding, Yanhuai; Xu, Fu; Zhang, Ping
2018-04-01
Recently, there has been a surge of interest in the research of two-dimensional (2D) phosphides due to their unique physical properties and wide applications. Transition metal phosphides 2H-M 2Ps (Mo2P, W2P, Nb2P and Ta2P) show considerable catalytic activity and energy storage potential. However, the electronic structure and mechanical properties of 2D 2H-M 2Ps are still unrevealed. Here, first-principles calculations are employed to investigate the lattice dynamics, elasticity and thermodynamic properties of 2H-M 2Ps. Results show that M 2Ps with lower stiffness exhibit remarkable lateral deformation under unidirectional loads. Due to the largest average Grüneisen parameter, single-layer Nb2P has the strongest anharmonic vibrations, resulting in the highest thermal expansion coefficient. The lattice thermal conductivities of Ta2P, W2P and Nb2P contradict classical theory, which would predict a smaller thermal conductivity due to the much heavier atom mass. Moreover, the calculations also demonstrate that the thermal conductivity of Ta2P is the highest as well as the lowest thermal expansion, owing to its weak anharmonic phonon scattering and the lowest average Grüneisen parameter. The insight provided by this study may be useful for future experimental and theoretical studies concerning 2D transition metal phosphide materials.
International Nuclear Information System (INIS)
Samardzic, O.; Hurn, J.A.; Weigold, E.; Brunger, M.J.
1994-01-01
The electron impact excitation of the (2s 2 ) 1 S, (2p 2 ) 1 D and (2s2p) 1 P autoionising states of helium and their subsequent radiationless decay was studied by observation of the ejected electrons. The present work was carried out at an incident energy of 94.6 eV and for ejected electron scattering angles in the range 25-135 deg C. The lineshapes observed in the present ejected electron spectra are analysed using the Shore-Balashov parametrisation. As part of the analysis procedure, numerically rigorous confidence limits were determined for the derived parameters. No previous experimental or theoretical work has been undertaken at the incident energy of the present investigation but, where possible, the resulting parameters are qualitatively compared against the 80 eV results of other experiments and theory. 37 refs., 4 figs
Magnetic Properties of Porous Metal-Organic Frameworks: Ni2(BODC)2(TED) and Ni2(BDC)2(TED)
Hamida, Youcef; Danilovic, Dusan; Lin, Chyan; Yuen, Tan; Li, Kunhao; Padmanabhan, Moothetty; Li, Jing
2010-03-01
Results of χ(T), M(H), and heat capacity C(T) measurements on two Ni dimer based porous materials Ni2(BODC)2(TED) and Ni2(BDC)2(TED) are reported. These materials form a tetragonal crystal structure of space group P4/ncc with a=b = 14.9 å and c = 19.4 å and Ni-Ni separation of 2.61å within the dimer. Magnetic data of Ni2(BODC)2(TED) revealed a ferromagnetic-like transition at about 17 K with θ = 8 K, and a coercivity field of 1700 G was observed in the hysteresis curve. Though isostructural to Ni2(BODC)2(TED), χ(T) and M(H) results of Ni2(BDC)2(TED) showed an antiferromagnetic transition at 10 K with θ = - 132 K, and no hysteresis was observed. Although specific heat data C(T) showed no clear transition in both compounds, nonlinear behavior is clearly seen in C/T vs. T plots, and a fit to the electron and phonon contributions to C(T) gives a large heavy-fermion-like γ in both cases. A model for the magnetic interactions is proposed and a comparison to the Cu and Co analogues is also made.
Full article: The Reaction between MoO3 and Molten K2S2O7 forming K2MoO2(SO4)2
DEFF Research Database (Denmark)
Nørbygaard, Thomas; Berg, Rolf W.; Nielsen, Kurt
1998-01-01
.4540(4), c = 8.8874(3) Å, beta = 112.194(1)o, wR2 = 0.0897 for 3491 independent reflections. The compound, K2MoO2(SO4)2, contains (Mo02)2+ core ions in distorted octahedral coordination, with two short (ca. 1.69 Å) terminal bonds in cis-configuration (the O-Mo-O angle is 103.1(2)o), and with two long (ca. 2...
2-(2-Chlorophenyl-2,3-dihydroquinazolin-4(1H-one
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Ming-Jian Li
2009-09-01
Full Text Available The title compound, C14H11ClN2O, was synthesized by the reaction of 2-chlorobenzaldehyde and 2-aminobenzamide in an ionic liquid. The pyrimidine ring adopts a skew-boat conformation and the two benzene rings make a dihedral angle of 87.1 (1°. In the crystal, N—H...O and C—H...N hydrogen bonding links the molecules along b.
International Nuclear Information System (INIS)
Pruess, K.; Oldenburg, C.M.; Moridis, G.J.
1999-01-01
TOUGH2 is a numerical simulator for nonisothermal flows of multicomponent, multiphase fluids in one, two, and three-dimensional porous and fractured media. The chief applications for which TOUGH2 is designed are in geothermal reservoir engineering, nuclear waste disposal, environmental assessment and remediation, and unsaturated and saturated zone hydrology. TOUGH2 was first released to the public in 1991; the 1991 code was updated in 1994 when a set of preconditioned conjugate gradient solvers was added to allow a more efficient solution of large problems. The current Version 2.0 features several new fluid property modules and offers enhanced process modeling capabilities, such as coupled reservoir-wellbore flow, precipitation and dissolution effects, and multiphase diffusion. Numerous improvements in previously released modules have been made and new user features have been added, such as enhanced linear equation solvers, and writing of graphics files. The T2VOC module for three-phase flows of water, air and a volatile organic chemical (VOC), and the T2DM module for hydrodynamic dispersion in 2-D flow systems have been integrated into the overall structure of the code and are included in the Version 2.0 package. Data inputs are upwardly compatible with the previous version. Coding changes were generally kept to a minimum, and were only made as needed to achieve the additional functionalities desired. TOUGH2 is written in standard FORTRAN77 and can be run on any platform, such as workstations, PCs, Macintosh, mainframe and supercomputers, for which appropriate FORTRAN compilers are available. This report is a self-contained guide to application of TOUGH2 to subsurface flow problems. It gives a technical description of the TOUGH2 code, including a discussion of the physical processes modeled, and the mathematical and numerical methods used. Illustrative sample problems are presented along with detailed instructions for preparing input data
Substituted 2,2′-bipyridines by nickel-catalysis: 4,4′-di-tert-butyl-2,2′-bipyridine
Buonomo, Joseph A.; Everson, Daniel A.; Weix, Daniel J.
2014-01-01
A simple, ligand-free synthesis of the important bipyridyl ligand 4,4′-di-tert-butyl-2,2′-bipyridine is presented. 5,5′-bis(trifluoromethyl)-2,2′-bipyridine is also synthesized by the same protocol. The syntheses efficiently couple the parent 2-chlorpyridies by a nickel-catalyzed dimerization with manganese powder as the terminal reductant. PMID:25221358
Energy Technology Data Exchange (ETDEWEB)
Anbazhagan, V. [School of Chemistry, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India); Renganathan, R. [School of Chemistry, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India)], E-mail: rrengas@yahoo.com
2009-04-15
The fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) by a series of uracils has been studied in water and acetonitrile solvents using steady-state and time-resolved fluorescence techniques. The steady-state fluorescence quenching technique has been performed in three different pHs (i.e. 4, 8 and 12). The bimolecular quenching rate constant (k{sub q}) increases with increase in pH of uracils. In acidic pH, a pure hydrogen atom abstraction is proposed as the quenching mechanism. This is supported by a pronounced solvent deuterium isotope effect. Electron transfer from the anionic form of uracil to the excited state of DBO is proposed as a mechanism for quenching in basic pH on the basis of highly exergonic thermodynamics obtained from the Rehm-Weller equation. The variation of k{sub q} is explained on the basis of the electronic effect of substitution in uracils as well.
International Nuclear Information System (INIS)
Anbazhagan, V.; Renganathan, R.
2009-01-01
The fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) by a series of uracils has been studied in water and acetonitrile solvents using steady-state and time-resolved fluorescence techniques. The steady-state fluorescence quenching technique has been performed in three different pHs (i.e. 4, 8 and 12). The bimolecular quenching rate constant (k q ) increases with increase in pH of uracils. In acidic pH, a pure hydrogen atom abstraction is proposed as the quenching mechanism. This is supported by a pronounced solvent deuterium isotope effect. Electron transfer from the anionic form of uracil to the excited state of DBO is proposed as a mechanism for quenching in basic pH on the basis of highly exergonic thermodynamics obtained from the Rehm-Weller equation. The variation of k q is explained on the basis of the electronic effect of substitution in uracils as well
Shirage, Parasharam M; Kihou, Kunihiro; Lee, Chul-Ho; Takeshita, Nao; Eisaki, Hiroshi; Iyo, Akira
2012-09-19
The effect of alloying the two perovskite-type iron-based superconductors (Ca(4)Al(2)O(6))(Fe(2)As(2)) and (Ca(4)Al(2)O(6))(Fe(2)P(2)) was examined. While the two stoichiometric compounds possess relatively high T(c)'s of 28 and 17 K, respectively, their solid solutions of the form (Ca(4)Al(2)O(6))(Fe(2)(As(1-x)P(x))(2)) do not show superconductivity over a wide range from x = 0.50 to 0.95. The resultant phase diagram is thus completely different from those of other typical iron-based superconductors such as BaFe(2)(As,P)(2) and LaFe(As,P)O, in which superconductivity shows up when P is substituted for As in the non-superconducting "parent" compounds. Notably, the solid solutions in the non-superconducting range exhibit resistivity anomalies at temperatures of 50-100 K. The behavior is reminiscent of the resistivity kink commonly observed in various non-superconducting parent compounds that signals the onset of antiferromagnetic/orthorhombic long-range order. The similarity suggests that the suppression of the superconductivity in the present case also has a magnetic and/or structural origin.
Superconductivity in the ternary rare-earth (Y, La, and Lu) compounds RPd2Si2 and RRh2Si2
Palstra, T.T.M.; Lu, G.; Menovsky, A.A.; Nieuwenhuys, G.J.; Kes, P.H.; Mydosh, J.A.
1986-01-01
We have investigated the superconducting and metallurgical properties of the ternary compounds RPd2Si2 and RRh2Si2 with R = Y, La, and Lu. All RPd2Si2 compounds and LaRh2Si2 were found to be type-I superconductors below 1 K. A detailed metallurgical analysis shows that segregation of second phases
A model for radiolysis of water and aqueous solutions of H2, H2O2 and O2
International Nuclear Information System (INIS)
Ershov, B.G.; Gordeev, A.V.
2008-01-01
Kinetic model for the radiolysis of pure water describing the formation of H 2 , H 2 O 2 and O 2 and the radiation chemical transformations of aqueous solutions containing these compounds over a broad range of concentrations, pH, absorbed doses and dose rates is proposed and substantiated. The model includes a set of chemical reactions with optimized rate constants and the radiation chemical yields of radiolysis products. The model applicability to the description of the whole set of data on the radiation chemical transformations of water and aqueous solutions of H 2 , H 2 O 2 and O 2 is demonstrated
Phase formation in the systems ZrO2-H2SO4-Na2SO4 (NaCl)-H2O
International Nuclear Information System (INIS)
Sozinova, Yu.P.; Motov, D.L.; Rys'kina, M.P.
1988-01-01
Formation of solid phases in the systems ZrO 2 - H 2 SO 4 - Na 2 SO 4 (NaCl) - H 2 O at 25 and 75 deg C is studied. Three basic Na 2 Zr(OH) 2 (SO 4 ) 2 x (0.2 - 0.4)H 2 O, NaZrOH(SO 4 ) 2 x H 2 O, NaZrO 0.5 (OH) 2 SO 4 x 2H 2 O and three normal sodium sulfatozirconates Na 2 Zr(SO 4 ) 3 x 3H 2 O, Na 4 Zr(SO 4 ) 4 x 3H 2 O, Na 6 Zr(SO 4 ) 5 x 4H 2 O have been isolated, their solubility and crystal optical properties are determined
Photoproduction of I2, Br2, and Cl2 on n-semiconducting powder
Reichman, B.; Byvik, C. E.
1981-01-01
The photosynthetic production of Br2 and Cl2 and the photocatalytic production of I2 from aqueous solutions of the respective halide ions in the presence of platinized semiconducting n-TiO2 powder are reported. Reactions were produced in 2-3 M oxygen-saturated aqueous solutions of KI, KBr or NaCl containing Pt-TiO2 powder which were irradiated by a high-pressure mercury lamp at a power of 400 mW/sq cm. Halogens are found to be produced in greater quantities when platinized TiO2 powders are used rather than pure TiO2, and rates of halogen production are observed to increase from Cl2 to Br2 to I2. The presence of the synthetic reactions producing Br2 and Cl2 with a net influx of energy indicates that an effective separation of the photoproduced electron-hole pair occurs in the semiconductor. Quantum efficiencies of the reaction, which increase with decreasing solution pH, are found to be as high as 30%, implying a solar-to-chemical energy conversion efficiency between 0.03% and 3% for the case of chlorine production. It is concluded that the photoproduction of halogens may be of practical value if product halogens are efficiently removed from the reaction cell.
2-[2-Benzoyl-3,3-bis(methylsulfanylprop-2-enylidene]malononitrile
Directory of Open Access Journals (Sweden)
Joseph Nirmala
2009-08-01
Full Text Available The title compound, C15H12N2OS2, is an example of a push–pull butadiene in which the electron-releasing methylsulfanyl groups and electron-withdrawing nitrile groups on either end of the butadiene chain enhance the conjugation in the system. Short intramolecular C—H...S interactions are observed. In the crystal structure, an O...C short contact of 2.917 (3 Å is observed.
Experimental and theoretical study of pure and doped crystals: Gd2O2S, Gd2O2S:Eu3+ and Gd2O2S:Tb3+
Wang, Fei; Chen, Xiumin; Liu, Dachun; Yang, Bin; Dai, Yongnian
2012-08-01
Quantum chemistry and experimental method were used to study on pure and doped Gd2O2S crystals in this paper. The band structure and DOS diagrams of pure and doped Gd2O2S crystals which calculated by using DFT (Density Functional Theory) method were illustrated to explain the luminescent properties of impurities in crystals. The calculations of the crystal structure were finished by using the program of CASTEP (Cambridge Sequential Total Energy Package). The samples showed the characteristic emissions of Tb3+ ions with 5D4-7FJ transitions and Eu3+ ions with 5D0-7FJ transitions which emit pure green luminescence and red luminescence respectively. The experimental excitation spectra of Tb3+ and Eu3+ doped Gd2O2S are in agreement of the DOS diagrams over the explored energy range, which has allowed a better understanding of different luminescence mechanisms of Tb3+ and Eu3+ in Gd2O2S crystals.
1,2-Bis(2-methoxy-6-formylphenoxyethane
Directory of Open Access Journals (Sweden)
Hongqi Li
2011-02-01
Full Text Available In the title compound [systematic name: 3,3′-dimethoxy-2,2′-(ethane-1,2-diyldioxydibenzaldehyde], C18H18O6, prepared from 1,2-dibromoethane and ortho-vanillin in the presence of sodium carbonate, the two vanillin units are linked via a CH2–CH2 bridge. The two benzene rings are inclined at a dihedral angle of 41.6 (5°.
Directory of Open Access Journals (Sweden)
Hery Haerudin
2010-06-01
Full Text Available Nickel catalysts, containing 6% (w/w of nickel, have been prepared using TiO2, Al2O3 and mixture of TiO2-Al2O3 (1:9. The catalysts were used for CO2 conversion into methane. The characteristics of catalysts were studied by determination of its specific surface area, temperature programmed reaction technique and X-ray diffraction. The specific surface area were varied slightly by different temperature of reduction, namely after reduction at 300°C it was 39, 120 and 113 m2/g and after reduction at 400°C it was 42, 135 and 120 m2/g for 6% nickel catalysts supported on TiO2, Al2O3 and mixture of TiO2-Al2O3 (1:9 respectively. Temperature program reaction studies (TPO and TPR showed that NiTiOx species were possibly formed during the pretreatments which has shown by the shift of its peak to the lower temperature on Ni catalyst, that supported on mixture of TiO2-Al2O3 compared with catalysts supported on individual TiO2 or Al2O3. The nickel species on reduced Ni catalysts supported on TiO2 and on mixture of TiO2-Al2O3 could be detected by X-ray diffraction. The catalyst's activities toward CH4 formation were affected by the reduction temperature. Activity for CH4 formation was decreased in the following order: Ni/ TiO2 > Ni/ TiO2: Al2O3 > Ni/ Al2O3 and Ni/ TiO2: Al2O3 > Ni/ TiO2> Ni/ Al2O3, when catalysts were reduced at 300°C or 400°C respectively. The CO2 conversion was decreased in the following order: Ni/ Al2O3 > Ni/ TiO2: Al2O3 > Ni/ TiO2 when catalysts were reduced at 300°C or 400°C respectively. Keywords: nickel catalyst, carbondioxide, methane
Monte Carlo simulation of semiconductor detector response to "2"2"2Rn and "2"2"0Rn environments
International Nuclear Information System (INIS)
Irlinger, J.; Trinkl, S.; Wielunksi, M.; Tschiersch, J.; Rühm, W.
2016-01-01
A new electronic radon/thoron monitor employing semiconductor detectors based on a passive diffusion chamber design has been recently developed at the Helmholtz Zentrum München (HMGU). This device allows for acquisition of alpha particle energy spectra, in order to distinguish alpha particles originating from radon and radon progeny decays, as well as those originating from thoron and its progeny decays. A Monte-Carlo application is described which uses the Geant4 toolkit to simulate these alpha particle spectra. Reasonable agreement between measured and simulated spectra were obtained for both "2"2"0Rn and "2"2"2Rn, in the energy range between 1 and 10 MeV. Measured calibration factors could be reproduced by the simulation, given the uncertainties involved in the measurement and simulation. The simulated alpha particle spectra can now be used to interpret spectra measured in mixed radon/thoron atmospheres. The results agreed well with measurements performed in both radon and thoron gas environments. It is concluded that the developed simulation allows for an accurate prediction of calibration factors and alpha particle energy spectra. - Highlights: • A method was developed to simulate alpha particle spectra from radon/thoron decay. • New monitor features alpha-particle-spectroscopy based on silicon detectors. • A method is presented to quantify radon/thoron concentrations in mixed atmospheres. • The calibration factor can be simulated for various environmental parameters.
Hausmann, David; Feldmann, Claus
2016-06-20
The bromine-rich zinc bromides Zn6Br12(18-crown-6)2×(Br2)5 (1), Zn4Br8(18-crown-6)2×(Br2)3 (2), and Zn6Br12(18-crown-6)2×(Br2)2 (3) are prepared by reaction of ZnBr2, 18-crown-6, and elemental bromine in the ionic liquid [MeBu3N][N(Tf)2] (N(Tf)2 = bis(trifluoromethylsulfonyl)amide). Zn6Br12(18-crown-6)2×(Br2)5 (1) is formed instantaneously by the reaction. Even at room temperature, compound 1 releases bromine, which was confirmed by thermogravimetry (TG) and mass spectrometry (MS). The release of Br2 can also be directly followed by the color and density of the title compounds. With controlled conditions (2 weeks, 25 °C, absence of excess Br2) Zn6Br12(18-crown-6)2×(Br2)5 (1) slowly releases bromine with conconcurrent generation of Zn4Br8(18-crown-6)2×(Br2)3 (2) (in ionic liquid) and Zn6Br12(18-crown-6)2×(Br2)2 (3) (in inert oil). All bromine-rich zinc bromides contain voluminous uncharged (e.g., Zn3Br6(18-crown-6), Zn2Br4(18-crown-6)) or ionic (e.g., [Zn2Br3(18-crown-6)](+), [(Zn2Br6)×(Br2)2](2-)) building units with dibromine molecules between the Zn oligomers and partially interconnecting the Zn-containing building units. Due to the structural similarity, the bromine release is possible via crystal-to-crystal transformation with retention of the crystal shape.
Optical properties of the Al2O3/SiO2 and Al2O3/HfO2/SiO2 antireflective coatings
Marszałek, Konstanty; Winkowski, Paweł; Jaglarz, Janusz
2014-01-01
Investigations of bilayer and trilayer Al2O3/SiO2 and Al2O3/HfO2/SiO2 antireflective coatings are presented in this paper. The oxide films were deposited on a heated quartz glass by e-gun evaporation in a vacuum of 5 × 10-3 [Pa] in the presence of oxygen. Depositions were performed at three different temperatures of the substrates: 100 °C, 200 °C and 300 °C. The coatings were deposited onto optical quartz glass (Corning HPFS). The thickness and deposition rate were controlled with Inficon XTC/2 thickness measuring system. Deposition rate was equal to 0.6 nm/s for Al2O3, 0.6 nm - 0.8 nm/s for HfO2 and 0.6 nm/s for SiO2. Simulations leading to optimization of the thin film thickness and the experimental results of optical measurements, which were carried out during and after the deposition process, have been presented. The optical thickness values, obtained from the measurements performed during the deposition process were as follows: 78 nm/78 nm for Al2O3/SiO2 and 78 nm/156 nm/78 nm for Al2O3/HfO2/SiO2. The results were then checked by ellipsometric technique. Reflectance of the films depended on the substrate temperature during the deposition process. Starting from 240 nm to the beginning of visible region, the average reflectance of the trilayer system was below 1 % and for the bilayer, minima of the reflectance were equal to 1.6 %, 1.15 % and 0.8 % for deposition temperatures of 100 °C, 200 °C and 300 °C, respectively.
Energy Technology Data Exchange (ETDEWEB)
Palmer, C J; Casida, J E [California Univ., Berkeley, CA (United States). Pesticide Chemistry and Toxicology Lab.
1991-07-01
Protection of the terminal alkyne function in 1-(4-ethynylphenyl)-4-(prop-2-enyl)-2,6,7-trioxabicyclo(2.2.2) octane with a trimethylsilyl group permits the selective catalytic reduction of the olefin moiety with tritium gas to give after deprotection 1-(4-ethynylphenyl)-4-(2,3-{sup 3}H{sub 2}) propyl-2,6,7-trioxabicyclo-(2.2.2) octane. The labeled product at high specific activity is an improved radioligand for the GABA-gated chloride channel of insects and mammals and the intermediate 4-(2,3-{sup 3}H{sub 2})propyl-1-(4-((trimethylsilyl)ethynyl)phenyl)-2,6,7-trioxabicyclo(2.2.2)octane is useful for studies on the metabolic activation of this selective proinsecticide. (author).
Directory of Open Access Journals (Sweden)
Chi-Heon Lee
2016-12-01
Full Text Available In the title compound, [Ir(C11H8N2(C18H14N], the IrIII ion adopts a distorted octahedral coordination environment defined by three C,N-chelating ligands, one stemming from a 2-(4-phenyl-5-methylpyridin-2-ylphenyl ligand and two from 2-(pyridin-2-ylphenyl ligands, arranged in a facial manner. The IrIII ion lies almost in the equatorial plane [deviation = 0.0069 (15 Å]. In the crystal, intermolecular π–π stacking interactions, as well as intermolecular C—H...π interactions, are present, leading to a three-dimensional network.
Modeling char conversion under suspension fired conditions in O2/N2 and O2/CO2 atmospheres
DEFF Research Database (Denmark)
Brix, Jacob; Jensen, Peter Arendt; Jensen, Anker Degn
2011-01-01
The aim of this investigation has been to model combustion under suspension fired conditions in O2/N2 and O2/CO2 mixtures. Experiments used for model validation have been carried out in an electrically heated Entrained Flow Reactor (EFR) at temperatures between 1173 K and 1673 K with inlet O2...... concentrations between 5 and 28 vol.%. The COal COmbustion MOdel, COCOMO, includes the three char morphologies: cenospheric char, network char and dense char each divided between six discrete particle sizes. Both combustion and gasification with CO2 are accounted for and reaction rates include thermal char...
2-Aminopyridinium (2-aminopyridinetrichloridonickelate(II
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T. Balasubramanian
2008-04-01
Full Text Available In the title compound, (C5H7N2[NiCl3(C5H6N2], the NiII atom is four-coordinated by three chloride anions and one N atom of a 2-aminopyridine ligand, forming a distorted tetrahedral coordination. In the crystal structure, cations and complex anions are linked into chains along the a, b and c axes by N—H...Cl hydrogen bonds, leading to the formation of a three-dimensional framework.
5,5-Dimethyl-2-methylseleno-1,3,2-dioxaphosphorinan-2-one
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Grzegorz Cholewinski
2010-04-01
Full Text Available The title compound, C6H13O3PSe, was obtained in the reaction of 5,5-dimethyl-2-oxo-2-seleno-1,3,2-dioxaphosphorinane potassium salt with methyl iodide. The selenomethyl group is in the axial position in relation to the six-membered dioxaphosphorinane ring.
Energy Technology Data Exchange (ETDEWEB)
Lemon, Christine E. [Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221 (United States); Goldberg, Nicola [Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221 (United States); Klein-Riffle, Evan T. [Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221 (United States); Kronberg, Jon K. [Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221 (United States); Ault, Bruce S. [Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221 (United States)], E-mail: bruce.ault@uc.edu
2006-08-01
The matrix-isolation technique has been combined with infrared spectroscopy and theoretical calculations to characterize the products of the photochemical reactions of C{sub 2}H{sub 3}Br and 1,2-C{sub 2}H{sub 2}Br{sub 2} with CrO{sub 2}Cl{sub 2}. For these systems, oxygen-atom transfer occurred upon visible-near ultraviolet irradiation, yielding bromoacetaldehyde and CrOCl{sub 2} in the former case and bromoacetyl bromide and CrCl{sub 2}O in the latter. For each system, the products were formed in the same matrix cage and strongly interacted to form a distinct molecular complex. No evidence was obtained for the acetyl bromide derivative in the C{sub 2}H{sub 3}Br system, indicating the occurrence of oxygen-atom attack at the less substituted carbon of vinyl bromide, nor was any evidence obtained for the formation of a possible five-membered metallocycle. Two different modes of interaction were explored computationally: {eta}{sup 1} (end-on) to the oxygen atom and {eta}{sup 2} (side-on) to the C=O bond. Theoretical calculations indicated that the {eta}{sup 1} complex of CH{sub 2}BrCHO-CrCl{sub 2}O was 13 kcal mol{sup -1} more stable than the {eta}{sup 2} complex at the B3LYP/6-311++G(d,2p) level of theory. The binding energy of the {eta}{sup 1} complex was found to be 21 kcal mol{sup -1}, compared to 8 kcal mol{sup -1} for the {eta}{sup 2} complex at this level of theory.
International Nuclear Information System (INIS)
English, R.B.; Liddell, R.J.; Whiteley, C.G.
1987-01-01
One pair of diastereomeric bromoamides, (2'R,1S,2S)- and (2'S,1S,2S)-N(2-bromopropanoyl)-2-amino-1-phenylpropane-1,3-diol have been synthesized from ethyl 2-bromopropionate and an optically active amino-diol. The crystal structures of both were determined from single-crystal X-ray analyses. Both compounds are orthorhombic with space group P2 1 2 1 2 1 with Z = 4 in a unit cell of dimensions a 22,124(5),b 12,812(5), and c 4,886(5)A and a 15,510(5), b 9,707(5), and c 9,457(5)A. The proton chemical shifts of the groups attached to the asymmetric centre C(2'), and consequently, the identification of the configuration of the molecules, were resolved with the help of high-resolution nuclear magnetic resonance
International Nuclear Information System (INIS)
Logemann, Christian; Witt, Julia; Wickleder, Mathias S.; Gunzelmann, Daniel; Senker, Juergen
2012-01-01
The reaction of the group 14 tetrachlorides MCl_4 (M = Si, Ge, Sn) with oleum (65 % SO_3) at elevated temperatures led to the unique anionic complexes [M(S_2O_7)_3]"2"- that show the central M atoms in coordination of three chelating S_2O_7"2"- groups. The mean distances M-O within the complexes increase from 175 pm (M = Si) via 186 pm (M = Ge) up to 200 pm (M = Sn). The charge balance for the [M(S_2O_7)_3]"2"- anions is achieved by alkaline metal ions A"+ (A = Li, Na, K, Rb, Cs) which were implemented in the syntheses in form of their sulfates. The size of the A"+ ions, i.e. their coordination requirement causes the crystallographic differences in the crystal structures, while the structure of the complex [M(S_2O_7)_3]"2"- anions remains essentially unaffected. Furthermore, we were able to characterize the unique germanate Hg_2[Ge(S_2O_7)_3]Cl_2 which forms when HgCl_2 is added as a source for the counter cation. The Hg"2"+ and the Cl"- ions form infinite cationic chains according to "1_∞[HgCl_2_/_2]"+ which take care for the charge compensation. For selected examples of the compounds the thermal behavior has been monitored by means of thermal analyses and X-ray powder diffraction. For A being an alkaline metal the decomposition product is a mixture of the sulfates A_2SO_4 and the dioxides MO_2, whereas Hg_2[Ge(S_2O_7)_3]Cl_2 shows a more complicated decomposition. The tris-(disulfato)-silicate Na_2[Si(S_2O_7)_3] has additionally been examined by solid state "2"9Si and "2"3Na NMR spectroscopic measurements. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Glass-ceramic enamels derived from the Li2O-Na2O-Al2O3-TiO2-SiO2 system
Directory of Open Access Journals (Sweden)
SNEZANA R. GRUJIC
2002-02-01
Full Text Available The results of research on the conditions for obtaining model glass-ceramic enamels, derived from the basic Li2O-Na2O-Al2O3-TiO2-SiO2 system, by varying the initial composition and thermal treatment conditions, are presented in this paper. Segregation of the crystal phases in the glassy-matrix was carried out during subsequent thermal treatment. The formation of different crystal phases was evidenced through the results of differential-thermal analysis and X-ray powder diffraction analysis.
Study of ZrO2-H2SO4-(NH4)2SO4(NH4Cl)-H2O systems
International Nuclear Information System (INIS)
Motov, D.L.; Sozinova, Yu.P.; Rys'kina, M.P.
1988-01-01
Regions of formation, composition and solubility of ammonium sulfatozirconates (ASZ) in ZrO 2 -H 2 SO 4 -(NH 4 ) 2 SO 4 (NH 4 Cl)-H 2 O systems at 25 and 75 deg C are studied by the isothermal method. Five ASZ: (NH 4 ) 2 Zr(OH) 2 (SO 4 ) 2 , NH 4 ZrOH(SO 4 ) 2 xH 2 O, NH 4 ZrO 0.5 (OH) 2 SO 4 x1.5H 2 O, (NH 4 ) 2 Zr(SO 4 ) 3 x2H 2 O, (NH 4 ) 4 Zr(SO 4 ) 4 x4H 2 O are detected, their properties are investigated. Main sulfates are new compounds never described ealier
Energy Technology Data Exchange (ETDEWEB)
Gourmelen, S
1997-12-19
Conformal invariance and supersymmetry are the two great fields of theoretical physics concerned with two dimensional conformal theories. These two dimensional conformal theories are here studied within the frame of supersymmetric N=2 extension in a no-metric formalism. The (2,0) and (2,2) Riemann super-surfaces (SSR) are characterized by Beltrami superfields. On such a SSR a superconformal field theory owns a local invariance linked to both diffeomorphisms and U-gauge symmetry. The study of these symmetries is carried out in the BRS formalism and applied to quantum anomaly determination. Sigma models are built on (2,0) and (2,2) SSR. Moreover the projective structures of SSR,N=2 are analysed by using a Schwartz connection which enables us to build super-differential covariant operators under superconformal transformations defined on SSR. These operators are categorized and their matrix analysis leads, owing to null curvature condition, to the study of W superalgebra. (author) 130 refs.
International Nuclear Information System (INIS)
Almassian, B.
1985-01-01
The finding of appreciable antileukemic activity in a series of 2-(2-methylthio-2-amino)vinyl-1-methylquinolinium iodides (Foye et al., 1980, 1983) suggested that greater basicity, as compared with the corresponding dithioacetic acids, was contributing to the increase in activity. The addition of a greater degree of basicity in the design of anticancer possibilities in this series was considered worth investigation, particularly in view of the activity of a series of bis(quanylhydrazones) synthesized at Lederle Laboratories. Accordingly, a series of guanylhydrazones of 4-pyridine-,2-pyridine- and 4-quinolinecarboxyaldehydes was synthesized for anticancer as well as antibacterial screening. Also, substitution of additional basic functions in the 2-(2-methylthio-2-amino) vinyl-1-methylquinolinium and pyridinium iodide series has been made. Appreciable antimicrobial activities have been found with both 2-pyridine and 4-quinolinealdehyde guanylhydrazones, as well as with 2-(2-methylthio-2-amino)vinyl-1-methyl-pyridinium iodides. The overall approach to the synthesis of potential anticancer agents in this project is thus to observe the effect of increasing basicity of these compounds on DNA binding and anticancer activity
UARS PEM Level 2 AXIS 2 V001 (UARPE2AXIS2) at GES DISC
National Aeronautics and Space Administration — The UARS Particle Environment Monitor (PEM) level 2 Atmosphere X-Ray Imaging Spectrometer (AXIS) unit 2 daily product contains the X-ray high-resolution spectral...
Directory of Open Access Journals (Sweden)
María Pimentel-Santillana
2014-01-01
Full Text Available The nucleotide uridine trisphosphate (UTP released to the extracellular milieu acts as a signaling molecule via activation of specific pyrimidine receptors (P2Y. P2Y receptors are G protein-coupled receptors expressed in many cell types. These receptors mediate several cell responses and they are involved in intracellular calcium mobilization. We investigated the role of the prostanoid PGE2 in P2Y signaling in mouse embryonic fibroblasts (MEFs, since these cells are involved in different ontogenic and physiopathological processes, among them is tissue repair following proinflammatory activation. Interestingly, Ca2+-mobilization induced by UTP-dependent P2Y activation was reduced by PGE2 when this prostanoid was produced by MEFs transfected with COX-2 or when PGE2 was added exogenously to the culture medium. This Ca2+-mobilization was important for the activation of different metabolic pathways in fibroblasts. Moreover, inhibition of COX-2 with selective coxibs prevented UTP-dependent P2Y activation in these cells. The inhibition of P2Y responses by PGE2 involves the activation of PKCs and PKD, a response that can be suppressed after pharmacological inhibition of these protein kinases. In addition to this, PGE2 reduces the fibroblast migration induced by P2Y-agonists such as UTP. Taken together, these data demonstrate that PGE2 is involved in the regulation of P2Y signaling in these cells.
Decken, Andreas; Knapp, Carsten; Nikiforov, Grigori B; Passmore, Jack; Rautiainen, J Mikko; Wang, Xinping; Zeng, Xiaoqing
2009-06-22
Pushing the limits of coordination chemistry: The most weakly coordinated silver complexes of the very weakly coordinating solvents dichloromethane and liquid sulfur dioxide were prepared. Special techniques at low temperatures and the use of weakly coordinating anions allowed structural characterization of [Ag(OSO)][Al{OC(CF(3))(3)}(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(Cl(2)CH(2))(2)][SbF(6)] (see figure). An investigation of the bonding shows that these complexes are mainly stabilized by electrostatic monopole-dipole interactions.The synthetically useful solvent-free silver(I) salt Ag[Al(pftb)(4)] (pftb=--OC(CF(3))(3)) was prepared by metathesis reaction of Li[Al(pftb)(4)] with Ag[SbF(6)] in liquid SO(2). The solvated complexes [Ag(OSO)][Al(pftb)(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(CH(2)Cl(2))(2)][SbF(6)] were prepared and isolated by special techniques at low temperatures and structurally characterized by single-crystal X-ray diffraction. The SO(2) complexes provide the first examples of coordination of the very weak Lewis base SO(2) to silver(I). The SO(2) molecule in [Ag(OSO)][Al(pftb)(4)] is eta(1)-O coordinated to Ag(+), while the SO(2) ligands in [Ag(OSO)(2/2)][SbF(6)] bridge two Ag(+) ions in an eta(2)-O,O' (trans,trans) manner. [Ag(CH(2)Cl(2))(2)][SbF(6)] contains [Ag(CH(2)Cl(2))(2)](+) ions linked through [SbF(6)](-) ions to give a polymeric structure. The solid-state silver(I) ion affinities (SIA) of SO(2) and CH(2)Cl(2), based on bond lengths and corresponding valence units in the corresponding complexes and tensimetric titrations of Ag[Al(pftb)(4)] and Ag[SbF(6)] with SO(2) vapor, show that SO(2) is a weaker ligand to Ag(+) than the commonly used weakly coordinating solvent CH(2)Cl(2) and indicated that binding strength of SO(2) to silver(I) in the silver(I) salts increases with increasing size of the corresponding counteranion ([Al(pftb)(4)](-)>[SbF(6)](-)). The experimental findings are in good agreement with theoretical gas-phase ligand
International Nuclear Information System (INIS)
Costa, Alice Miranda Ribeiro
2016-01-01
Natural radionuclides from "2"3"8U and "2"3"2Th series have been successfully applied as tracers of environmental process and climate changes. The "2"1"0Pb (half-life of 22.2 years) is used in the geochronological dating technique of sediment cores of the last 100-150 years, and its respective sedimentation rate determination. The study of "2"2"6Ra and "2"2"8Ra concentrations (half-lives of 1,600 years and 5.75 years, respectively) helps calculate the activity of "2"1"0Pb in excess in the environment, besides being important tracers of marine processes, as ground water discharge. In this work it was determined the activity concentrations of "2"2"6Ra, "2"2"8Ra and "2"1"0Pb in four short marine cores collected since the continental platform to upper slope of Southwest Atlantic Ocean. Taking into account the results obtained, sedimentation rates and the ages of each sediment layer were determined using the geochronological dating method with "2"1"0Pb. All sediment samples were total acid digested in microwave. The sequential radiochemical separation of "2"2"6Ra, "2"2"8Ra, "2"1"0Pb were performed, obtaining in the end the precipitation of Ba(Ra)SO_4 and PbCrO_4. The gross α measurements of "2"2"6Ra and gross β measurements of "2"2"8Ra and "2"1"0Pb from the precipitates were carried out in a gas-flow low background proportional counter. Concerning all cores analyzed, the activities concentrations of "2"2"6Ra ranged from 14 Bq.kg"-"1 to 154 Bq.kg"-"1; the concentrations of "2"2"8Ra ranged from 17 Bq.kg"-"1 to 45 Bq.kg"-"1; and the concentrations of "2"1"0Pb ranged from 20 Bq.kg"-"1 to 2,073 Bq.kg"-"1. High values of "2"1"0Pb were observed on the top of all the cores studied, mainly related to atmospheric deposition. The results obtained in this work were of the same order of magnitude of those reported in the literature available on non contaminated areas of Southeast Brazilian Coast. Sedimentation rates fall with the increase of water column depth and ranged from 0
International Nuclear Information System (INIS)
Bruyn, A. de; Anteunis, M.
1975-01-01
Complete analyses of the 1 H n.m.r. spectra at 300 MHz of D 2 O solutions of 2-deoxy-D-arabino-hexopyranose, 2-deoxy-D-lyxo-hexopyranose and 2'-deoxy lactose. Chemical shifts in the deoxy monosaccharides and in 2'-deoxy lactose. Chemical shifts in the deoxy monosaccharides and in 2'-deoxy lactose are compared with those previously obtained in the parent aldeohexopyranoses, glucobioses and D-galactopyranosol-D-glucoses. Increment values are suggested in order to predict chemical shifts in 2-deoxy derivatives from the well known rules for aldohexopyranoses. (author)
Dielectric Behaviour of Binary Mixture of 2-Chloroaniline with 2-Methoxyethanol and 2-Ethoxyethanol
Directory of Open Access Journals (Sweden)
Bhupesh G. Nemmaniwar
2013-05-01
Full Text Available Densities, viscosities, refractive indices, dielectric constant (ε' and dielectric loss (ε'' of 2-chloroaniline (2CA + 2-methoxyethanol (2ME and 2-chloroaniline (2CA + 2-ethoxyethanol (2EE for different mole fractions of 2-chloroaniline in binary mixture have been measured at single microwave frequency 10.985 GHz at 300C by Surber method using microwave X-band. The values of dielectric parameters (ε' and ε'' have been used to evaluate the molar polarization (P12 loss tangent (tanδ, viscosity (η, activation energy (Ea, excess permittivity (Δε', excess dielectric loss (Δε'', excess viscosities (Δη, excess polarization (ΔP12 and excess activation energy (ΔEa have also been estimated. These parameters have been used to explain the formation of complexes in the system. It is found that dielectric constant (ε', dielectric loss (ε'', loss tangent (tanδ, molar polarization (P12 varies non-linearly but activation energy (Ea , viscosity (η ,density (ρ, and refractive index (n varies linearly with increasing mole fraction in binary mixture of 2-chloroaniline (2-CA + 2-methoxyethanol (2-ME and 2-chloroaniline (2-CA + 2-ethoxyethanol (2-EE. Hence, solute-solvent molecular associations have been reported.
Energy Technology Data Exchange (ETDEWEB)
Kocakoç, Mehpeyker, E-mail: mkocakoc@cu.edu.tr [Çukurova University (Turkey); Tapramaz, Recep, E-mail: recept@omu.edu.tr [Ondokuz Mayıs University (Turkey)
2016-03-25
Acesulfame potassium salt is a synthetic and non-caloric sweetener. It is also important chemically for its capability of being ligand in coordination compounds, because it can bind over Nitrogen and Oxygen atoms of carbonyl and sulfonyl groups and ring oxygen. Some acesulfame containing transition metal ion complexes with mixed ligands exhibit solvato and thermo chromic properties and these properties make them physically important. In this work single crystals of Mn{sup +2} ion complex with mixed ligand, [Mn(acs){sub 2}(2-pic){sub 2}(H{sub 2}O){sub 2}], was studied with electron paramagnetic resonance (EPR) spectroscopy. EPR parameters were determined. Zero field splitting parameters indicated that the complex was highly symmetric. Variable temperature studies showed no detectable chance in spectra.
Experimental Ion Mobility measurements in Ne-CO$_2$ and CO$_2$-N$_2$ mixtures
Encarnação, P.M.C.C.; Veenhof, R.; Neves, P.N.B.; Santos, F.P.; Trindade, A.M.F.; Borges, F.I.G.M.; Conde, C.A.N.
2016-01-01
In this paper we present the experimental results for the mobility, K0, of ions in neon-carbon dioxide (Ne-CO2) and carbon dioxide-nitrogen (CO2-N2) gaseous mixtures for total pressures ranging from 8–12 Torr, reduced electric fields in the 10–25 Td range, at room temperature. Regarding the Ne-CO2 mixture only one peak was observed for CO2 concentrations above 25%, which has been identified as an ion originated in CO2, while below 25% of CO2 a second-small peak appears at the left side of the main peak, which has been attributed to impurities. The mobility values for the main peak range between 3.51 ± 0.05 and 1.07 ± 0.01 cm2V−1s−1 in the 10%-99% interval of CO2, and from 4.61 ± 0.19 to 3.00 ± 0.09 cm2V−1s−1 for the second peak observed (10%–25% of CO2). For the CO2-N2, the time-of-arrival spectra displayed only one peak for CO2 concentrations above 10%, which was attributed to ions originated in CO2, namely CO2+(CO2), with a second peak appearing for CO2 concentrations below 10%. This secon...
Insight into π-hole interactions containing the inorganic heterocyclic compounds S2N2/SN2P2.
Lu, Bo; Zhang, Xueying; Meng, Lingpeng; Zeng, Yanli
2017-08-01
Similar to σ-hole interactions, the π-hole interaction has attracted much attention in recent years. According to the positive electrostatic potentials above and below the surface of inorganic heterocyclic compounds S 2 N 2 and three SN 2 P 2 isomers (heterocyclic compounds 1-4), and the negative electrostatic potential outside the X atom of XH 3 (X = N, P, As), S 2 N 2 /SN 2 P 2 ⋯XH 3 (X = N, P, As) complexes were constructed and optimized at the MP2/aug-cc-pVTZ level. The X atom of XH 3 (X = N, P, As) is almost perpendicular to the ring of the heterocyclic compounds. The π-hole interaction energy becomes greater as the trend goes from 1⋯XH 3 to 4⋯XH 3 . These π-hole interactions are weak and belong to "closed-shell" noncovalent interactions. According to the energy decomposition analysis, of the three attractive terms, the dispersion energy contributes more than the electrostatic energy. The polarization effect also plays an important role in the formation of π-hole complexes, with the contrasting phenomena of decreasing electronic density in the π-hole region and increasing electric density outside the X atom of XH 3 (X = N, P, As). Graphical abstract Computed density difference plots for the complexes 3⋯NH 3 (a 1 ), 3⋯PH 3 (b 1 ), 3⋯AsH 3 (c 1 ) and electron density shifts for the complexes 3⋯NH 3 (a 2 ), 3⋯PH 3 (b 2 ),3⋯AsH 3 (c 2 ) on the 0.001 a.u. contour.
(2-Pyridyl[5-(2-pyridylcarbonyl-2-pyridyl]methanone
Directory of Open Access Journals (Sweden)
Zi-jia Wang
2010-10-01
Full Text Available In the centrosymmetric title compound, C17H11N3O2, the dihedral angle between the central and pendant pyridyl rings is 50.29 (9°. In the crystal, molecules stack along the a axis by π–π interactions between the pyridine rings with centroid–centroid distances of 3.845 (2 Å. The N atom and one of the C atoms of the central ring are disordered by symmetry.
International Nuclear Information System (INIS)
Abreu, Amanda Jordão de
2012-01-01
Nowadays, the methane reforming is large interest industrial for the take advantage of these gas in production the hydrogen and synthesis gas (syngas). Among in the reactions of methane stand of the reactions steam reforming and carbon dioxide reforming of methane. The main catalysts uses in the methane reforming is Ni/Al 2 O 3 . However, the supported-nickel catalyst is susceptible to the deactivation or the destruction by coke deposition. The carbon dissolves in the nickel crystallite and its diffuses through the nickel, leading for formation of the carbon whiskers, which results in fragmentation of the catalyst. Modification of such catalysts, like incorporation of suitable promoters, is desirable to achieve reduction of the methane hydrogenolysis and/or promotion of the carbon gasification. Catalysts 5%Ni/Al 2 O 3 supported on solid solutions formed by ZrO 2 -CeO 2 , La 2 O 3 and CeO 2 -ZrO 2 -La 2 O 3 were prepared, characterized and evaluated in reactions steam and carbon dioxide reforming and partial oxidation of methane with objective the value effect loading solution solid in support. The supports were prepared by co-precipitation method and catalysts were prepared by impregnation method and calcined at 500 deg C. The supports and catalysts were characterized by Nitrogen Adsorption, method -rays diffraction (XRD), X-rays dispersive spectroscopy (XDS), spectroscopy in the region of the ultraviolet and the visible (UV-vis NIR) to and temperature programmed reduction (TPR), Raman Spectroscopy, X-ray absorption spectroscopy and Thermogravimetric Analysis. After all the catalytic reactions check which the addition of solid solution is beneficial for Ni/Al 2 O 3 catalysts and the best catalysts are Ni/CeO 2 -La 2 O 3 -Al 2 O 3 . (author)
Supersymmetric D2 anti-D2 Strings
Bak, Dongsu; Ohta, Nobuyoshi
2001-01-01
We consider the flat supersymmetric D2 and anti-D2 system, which follows from ordinary noncommutative D2 anti-D2 branes by turning on an appropriate worldvolume electric field describing dissolved fundamental strings. We study the strings stretched between D2 and anti-D2 branes and show explicitly that the would-be tachyonic states become massless. We compute the string spectrum and clarify the induced noncommutativity on the worldvolume. The results are compared with the matrix theory descri...
ANOPP2 User's Manual: Version 1.2
Lopes, L. V.; Burley, C. L.
2016-01-01
This manual documents the Aircraft NOise Prediction Program 2 (ANOPP2). ANOPP2 is a toolkit that includes a framework, noise prediction methods, and peripheral software to aid a user in predicting and understanding aircraft noise. This manual includes an explanation of the overall design and structure of ANOPP2, including a brief introduction to aircraft noise prediction and the ANOPP2 background, philosophy, and architecture. The concept of nested acoustic data surfaces and its application to a mixed-fidelity noise prediction are presented. The structure and usage of ANOPP2, which includes the communication between the user, the ANOPP2 framework, and noise prediction methods, are presented for two scenarios: wind-tunnel and flight. These scenarios serve to provide the user with guidance and documentation references for performing a noise prediction using ANOPP2.
2.4 μm diode-pumped Dy2+:CaF2 laser
Švejkar, Richard; Papashvili, Alexander G.; Šulc, Jan; Němec, Michal; Jelínková, Helena; Doroshenko, Maxim E.; Batygov, Sergei H.; Osiko, Vyacheslav V.
2018-01-01
In this work, a cryogenic cooled, longitudinal diode-pumped Dy2+ :CaF2 laser was investigated for the first time. The temperature dependence of the spectroscopy and the laser properties of Dy2+ :CaF2 are presented. The tested Dy2+ :CaF2 crystal was a longitudinal pump in a near-IR region (926 nm) by laser diode radiation. The maximal mean output power and slope efficiency at 78 K during the pulse regime of the laser were 57.5 mW and 7%, respectively. Furthermore, the CW regime was successfully tested and a maximum output power of 0.37 W was obtained for the absorbed pumping power 5.7 W. The emission laser wavelength was 2367 nm.
(E-1-(2-Bromophenyl-3-(2,5-dimethoxyphenylprop-2-en-1-one
Directory of Open Access Journals (Sweden)
Jerry P. Jasinski
2010-08-01
Full Text Available The title compound, C17H15BrO3, is a chalcone with the 2-bromophenyl and 2,5-dimethoxyphenyl rings bonded at opposite ends of a propene group. The dihedral angle between the mean planes of the ortho-bromo and ortho,meta-dimethoxy-substituted benzene rings is 77.3 (1°. The dihedral angles between the mean plane of the prop-2-ene-1-one group and the mean planes of the 2-bromophenyl and 2,5-dimethoxyphenyl rings are 58.6 (1 and 30.7 (4°, respectively. Weak C—H...O, C—H...Br and π–π stacking intermolecular interactions [centroid–centroid distance = 3.650 (2 Å] are present in the structure.
Directory of Open Access Journals (Sweden)
Sarr Mamour
2018-05-01
Full Text Available The 2-hydrazinopyridine precursor has been widely used to prepare ligands of various kinds by condensation with carbonyl compounds. These types of ligands are suitable for synthesizing novel transition metal (II complexes with interesting magnetic properties. In this context we have synthesized the ligand 1-(2-hydroxyphenyl-2-ethylidene-2-(pyridin-2-ylhydrazine (HL which was used in the preparation of the mononuclear title complex, [Ni(C13H12N3O(C13H13N3O]NO3·0.5H2O. As a result of the presence of HL and L in the [{Ni(HL(L}]+ unit, the complex appears to be a supramolecular dimer composed of the Δ(− and Λ(− optical isomers, which are linked by strong hydrogen-bonds. As well as the dimer generated by two mononuclear [{Ni(HL(L}]+ cations, the asymmetric unit also contains two nitrate anions and one water molecule. Each Ni atom is coordinated to two ligand molecules by a nitrogen atom of the pyridine ring, an imine nitrogen atom and a phenolic oxygen atom of one of the ligand molecules and a phenolate oxygen atom of the other organic molecules. The environment around the cation is a distorted octahedron. The basal planes are defined by the two nitrogen atoms of the pyridine rings and the two phenolic oxygen atoms of the ligand, the apical positions being occupied by the azomethine atoms. The O atoms of one of the nitrate ions are disordered over two sets of sites in a 0.745 (9:0.255 (9 ratio. In the crystal, the dimers are linked by numerous hydrogen bonds, forming a three-dimensional framework.
First-principles study on cubic pyrochlore iridates Y2Ir2O7 and Pr2Ir2O7
International Nuclear Information System (INIS)
Ishii, Fumiyuki; Mizuta, Yo Pierre; Kato, Takehiro; Ozaki, Taisuke; Weng Hongming; Onoda, Shigeki
2015-01-01
Fully relativistic first-principles electronic structure calculations based on a noncollinear local spin density approximation (LSDA) are performed for pyrochlore iridates Y 2 Ir 2 O 7 and Pr 2 Ir 2 O 7 . The all-in, all-out antiferromagnetic (AF) order is stablized by the on-site Coulomb repulsion U > U c in the LSDA+U scheme, with U c ∼ 1.1 eV and 1.3 eV for Y 2 Ir 2 O 7 and Pr 2 Ir 2 O 7 , respectively. AF semimetals with and without Weyl points and then a topologically trivial AF insulator successively appear with further increasing U. For U = 1.3 eV, Y 2 Ir 2 O 7 is a topologically trivial narrow-gap AF insulator having an ordered local magnetic moment ∼0.5μ B /Ir, while Pr 2 Ir 2 O 7 is barely a paramagnetic semimetal with electron and hole concentrations of 0.016/Ir, in overall agreements with experiments. With decreasing oxygen position parameter x describing the trigonal compression of IrO 6 octahedra, Pr 2 Ir 2 O 7 is driven through a non-Fermi-liquid semimetal having only an isolated Fermi point of Γ 8 + , showing a quadratic band touching, to a Z 2 topological insulator. (author)
Anbazhagan, V; Kalaiselvan, A; Jaccob, M; Venuvanalingam, P; Renganathan, R
2008-05-29
The fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) by seven flavonoids namely flavone, flavanone, quercetin, rutin, genistein, diadzein and chrysin has been investigated in acetonitrile and dichloromethane solvents. The bimolecular quenching rate constants lie in the range of 0.09-5.75 x 10(9)M(-1)s(-1) and are explained in terms of structure of the flavonoids studied. The reactivity of flavonoids are in the order: quercetin>rutin>genistein>diadzein>chrysin>flavone>flavanone. The quenching rate constants (k(q)) increase with increase in the number of -OH groups. The endergonic thermodynamic values of DeltaG(et) reveal that electron transfer quenching mechanism can be ruled out. Bond dissociation enthalpy calculations reveal that the position of -OH is important. Further in vitro-antioxidant activities of flavonoids were evaluated with rat liver catalase by gel electrophoresis. The deuterium isotope effect thus observed in this work provides evidence for hydrogen abstraction involved in the quenching process of singlet excited DBO by flavonoids. The data suggest the involvement of direct hydrogen atom transfer (radical scavenging) in the fluorescence quenching of DBO. Bond dissociation enthalpy calculation performed at B3LYP/6-31G(p')//B3LYP/3-21G level are in excellent agreement with the above observations and further reveal that the number OH groups and position of them decide the quenching ability of the flavonoids.
Energy Technology Data Exchange (ETDEWEB)
Haiges, Ralf; Christe, Karl O. [Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, Los Angeles, CA (United States); Vasiliu, Monica; Dixon, David A. [Department of Chemistry, The University of Alabama, Tuscaloosa, AL (United States)
2017-01-12
The reaction between [UO{sub 2}F{sub 2}] and an excess of Me{sub 3}SiN{sub 3} in acetonitrile solution results in fluoride-azide exchange and the uranium(VI) dioxodiazide adduct [UO{sub 2}(N{sub 3}){sub 2}.CH{sub 3}CN] was isolated in quantitative yield. The subsequent reaction of [UO{sub 2}(N{sub 3}){sub 2}.CH{sub 3}CN] with 2,2{sup '}-bipyridine (bipy) resulted in the formation of the azido-bridged binuclear complex [(bipy){sub 2}(UO{sub 2}){sub 2}(N{sub 3}){sub 4}]. The triazido anion [(bipy)UO{sub 2}(N{sub 3}){sub 3}]{sup -} was obtained by the reaction of [UO{sub 2}(N{sub 3}){sub 2}.CH{sub 3}CN] with stoichiometric amounts of bipy and the ionic azide [PPh{sub 4}][N{sub 3}]. The reaction of [UO{sub 2}(N{sub 3}){sub 2}] with two equivalents of the [PPh{sub 4}][N{sub 3}] resulted in the formation of the mononuclear tetraazido anion [UO{sub 2}(N{sub 3}){sub 4}]{sup 2-} as well as the azido-bridged binuclear anion [(UO{sub 2}){sub 2}(N{sub 3}){sub 8}]{sup 4-}. The novel uranium oxoazides were characterized by their vibrational spectra and in the case of [(bipy){sub 2}(UO{sub 2}){sub 2}(N{sub 3}){sub 4}].CH{sub 3}CN, [PPh{sub 4}][(bipy)UO{sub 2}(N{sub 3}){sub 3}], [PPh{sub 4}]{sub 2}[UO{sub 2}(N{sub 3}){sub 4}], [PPh{sub 4}]{sub 2}[UO{sub 2}(N{sub 3}){sub 4}].2CH{sub 3}CN, and [PPh{sub 4}]{sub 4}[(UO{sub 2}){sub 2}(N{sub 3}){sub 8}].4CH{sub 3}CN by their X-ray crystal structures. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)
Farkašová, Nela; Cernák, Juraj; Tomás, Milagros; Falvello, Larry R
2014-05-01
The reaction of NiCl2, K2C2O4·H2O and 2,2'-bipyridine (bpy) in water-ethanol solution at 281 K yields light-purple needles of the new pentahydrate of bis(2,2'-bipyridine)oxalatonickel(II), [Ni(C2O4)(C10H8N2)2]·5H2O or [Ni(ox)(bpy)2]·5H2O, while at room temperature, deep-pink prisms of the previously reported tetrahydrate [Ni(ox)(bpy)2]·4H2O [Román, Luque, Guzmán-Miralles & Beitia (1995), Polyhedron, 14, 2863-2869] were gathered. The asymmetric unit in the crystal structure of the new pentahydrate incorporates the discrete molecular complex [Ni(ox)(bpy)2] and five solvent water molecules. Within the complex molecule, all three ligands are bonded as chelates. The complex molecules are involved in an extended system of hydrogen bonds with the solvent water molecules. Additionally, π-π interactions also contribute to the stabilization of the extended structure. The dehydration of the pentahydrate starts at 323 K and proceeds in at least two steps as determined by thermal analysis.
Structure of cadmium chloride complex with thiosemicarbazide Cd(NH2CSNHNH2)Cl2xH2O
International Nuclear Information System (INIS)
Gusev, A.I.; Chuklanova, E.B.; Murzubraimov, B.; Toktomamatov, A.
1985-01-01
The X-ray diffraction investigation of crystal and molecular structures of cadmium chloride complex with thiosemicarbaride is performed. Crystals are monoclinic with unit cell parameters: a=10.121(2), b=13.927(2), c=6.894(1) A, β=124.13(1) deg, Z=4, Cc sp. gr. The crystal structure consists of [Cd(NH 2 CSNHxNH 2 )Cl 2 ]n polymer chains and crystallization water molecules located between these chains. The cadmium coordination number equals 6, coordination polyhedron - tetragonal bipyramid
OS2_OSCAT_LEVEL_2B_OWV_COMP_12_V2:1
National Aeronautics and Space Administration — This dataset consists of the version 2 Level 2B science-quality ocean surface wind vector retrievals from the Oceansat-2 scatterometer (OSCAT), which was designed...
Energy Technology Data Exchange (ETDEWEB)
Sun Xilan; Peng Bin [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Yan Weidong [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China)], E-mail: yanweidong@zju.edu.cn
2008-04-15
The solubilities of trans-resveratrol in methanol, ethanol, 1-propanol, 2- propanol, 1-butanol, 1-pentanol, 1-hexanol, ethyl acetate, tetrahydrofuran, acetone, and water (pH 6.0) solvents were measured at T = (278.2, 288.2, 298.2, 308.2, and 318.2) K. The solubilities of trans-resveratrol in selected solvents increase with temperature, but decrease with increasing the number of carbon in alcohol solvents. The experimental data were correlated using a thermodynamic equation.
International Nuclear Information System (INIS)
Sun Xilan; Peng Bin; Yan Weidong
2008-01-01
The solubilities of trans-resveratrol in methanol, ethanol, 1-propanol, 2- propanol, 1-butanol, 1-pentanol, 1-hexanol, ethyl acetate, tetrahydrofuran, acetone, and water (pH 6.0) solvents were measured at T = (278.2, 288.2, 298.2, 308.2, and 318.2) K. The solubilities of trans-resveratrol in selected solvents increase with temperature, but decrease with increasing the number of carbon in alcohol solvents. The experimental data were correlated using a thermodynamic equation
Energy Technology Data Exchange (ETDEWEB)
Shi, Xiangli [Environment Research Institute, Shandong University, Jinan 250100 (China); Yu, Wanni [Environment Research Institute, Shandong University, Jinan 250100 (China); College of Resources and Environment, Linyi University, Linyi 276000 (China); Xu, Fei [Environment Research Institute, Shandong University, Jinan 250100 (China); Zhang, Qingzhu, E-mail: zqz@sdu.edu.cn [Environment Research Institute, Shandong University, Jinan 250100 (China); Hu, Jingtian; Wang, Wenxing [Environment Research Institute, Shandong University, Jinan 250100 (China)
2015-09-15
Highlights: • We studied the formation of PBCDD/Fs from the reaction of three CPRs with BPRs. • The substitution pattern of halogenated phenols determines those of PBCDD/Fs. • The substitution of halogenated phenols influence the coupling of phenoxy radicals. • The rate constants of the crucial elementary steps were evaluated. - Abstract: Quantum chemical calculations were carried out to investigate the homogeneous gas-phase formation of mixed polybrominated/chlorinated dibenzo-p-dioxins/benzofurans (PBCDD/Fs) from the cross-condensation of 2-chlorophenoxy radical (2-CPR) with 2-bromophenoxy radical (2-BPR), 2,4-dichlorophenoxy radical (2,4-DCPR) with 2,4-dibromophenoxy radical (2,4-DBPR), and 2,4,6-trichlorophenoxy radical (2,4,6-TCPR) with 2,4,6-tribromophenoxy radical (2,4,6-TBPR). The geometrical parameters and vibrational frequencies were calculated at the MPWB1K/6-31+G(d,p) level, and single-point energy calculations were performed at the MPWB1K/6-311+G(3df,2p) level of theory. The rate constants of the crucial elementary reactions were evaluated by the canonical variational transition-state (CVT) theory with the small curvature tunneling (SCT) correction over a wide temperature range of 600–1200 K. Studies show that the substitution pattern of halogenated phenols not only determines the substitution pattern of the resulting PBCDD/Fs, but also has a significant influence on the formation mechanism of PBCDD/Fs, especially on the coupling of the halogenated phenoxy radicals.
Energy Technology Data Exchange (ETDEWEB)
Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Knotko, A.V. [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Geological Faculty, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Pani, M. [Department of Chemistry, University of Genova, Via Dodecaneso 31, 16146 Genova (Italy); Institute SPIN-CNR, C. Perrone 24, 16152 Genova (Italy); Nirmala, R. [Indian Institute of Technology Madras, Chennai 600036 (India); Quezado, S.; Malik, S.K. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59082-970 (Brazil)
2016-09-01
Magnetic and magnetocaloric properties of Sc{sub 2}CoSi{sub 2}-type R{sub 2}TSi{sub 2} (R=Gd–Er, T=Fe, Co) compounds have been studied using magnetization data. These indicate the presence of mixed ferromagnetic and antiferromagnetic interactions in these compounds. One observes a ferromagnetic transition followed by an antiferromagnetic order and a further possible spin-reorientation transition at low temperatures. Compared to Gd{sub 2}{Fe, Co}Si{sub 2}, the Tb{sub 2}FeSi{sub 2} and {Tb–Er}{sub 2}CoSi{sub 2} compounds exhibit remarkable hysteresis (for e.g. Tb{sub 2}FeSi{sub 2} shows residual magnetization M{sub res}/Tb=2.45 μ{sub B}, coercive field H{sub coer}=14.9 kOe, and critical field H{sub crit}~5 kOe at 5 K) possibly due to the magnetocrystalline anisotropy of the rare earth. The R{sub 2}{Fe, Co}Si{sub 2} show relatively small magnetocaloric effect (i.e. isothermal magnetic entropy change, ΔS{sub m}) around the magnetic transition temperature: the maximal value of MCE is demonstrated by Ho{sub 2}CoSi{sub 2} (ΔS{sub m}=−8.1 J/kg K at 72 K and ΔS{sub m}=−9.4 J/kg K at 23 K in field change of 50 kOe) and Er{sub 2}CoSi{sub 2} (ΔS{sub m}=−13.6 J/kg K at 32 K and ΔS{sub m}=−8.4 J/kg K at 12 K in field change of 50 kOe). - Highlights: • {Gd–Er}{sub 2}{Fe, Co}Si{sub 2} show high-temperature ferromagnetic-type transitions. • {Gd–Er}{sub 2}{Fe, Co}Si{sub 2} show low-temperature spin-reorientation transitions. • Tb{sub 2}FeSi{sub 2} and {Tb–Er}{sub 2}CoSi{sub 2} compounds exhibit low-temperature hysteresis. • Tb{sub 2}FeSi{sub 2} shows M{sub res}/Tb=2.45 μ{sub B}, H{sub coer}=14.9 kOe and H{sub crit} ~5 kOe at 5 K • Considerable magnetocaloric effect is exhibited by Ho{sub 2}CoSi{sub 2} and Er{sub 2}CoSi{sub 2}.
Some studies about the NaCl:Ca2+ :Mn2+ and NaCl: Cd2+ :Mn2+ dosemeters
International Nuclear Information System (INIS)
Verdiguel G, H.; Flores J, C.; Camarillo G, E.; Espejel P, R.; Cabrera B, E.; Hernandez A, J.; Murrieta S, H.; Cruz Z, E.; Ramos B, S.; Negron, A.
2002-01-01
Nowadays, a great interest by counting with dosemeters of characteristics such as a high stability, of easy operation and easier production exists. Looking for a commitment with all these characteristics,a possibility to use the system NaCl: Ca 2+ :Mn 2+ and NaCl: Cd 2+ :Mn 2+ as dosemeters was studied. The studies were realized irradiating with gamma radiation from a 60 Co source. The crystals that were used as samples did not suffer any thermal treatment previous to irradiation. The supplied doses were 10, 30, 60, 100, 300, and 600 rads. 24 hours after irradiation the thermoluminescent response was obtained. In the case of the system NaCl: Ca 2+ :Mn 2+ several thermoluminescent bands were observed (BTL). Two concentrations of Mn 2+ with only one concentration of Ca 2+ (1%) were studied. For the case of the smaller concentration of Mn 2+ (0.1%) 4 BTL were observed, whereas for a greater concentration (0.3%) just 2 BTL were detected. The positions of the maximum of the BTL peaks differ for both concentrations, this possible due to what the nature of the traps for both cases differs by the type of precipitates present in the net. For the case of the system NaCl: Cd 2+ (1%) :Mn 2+ (0.1% and 0.5%) a similar situation to the previous was found, although in this case for both manganese concentrations just 2 BTL were observed; however all the peaks seem to be the superposition of several bands. Despite the apparent complexity of the thermoluminescent response, such response as function of the dose shows that both systems present a stable response to gamma radiation in the interval from 10 to 600 rads. In the case of calcium it is had a response of linear type of the Tl intensity depending on the dose, whereas for the cadmium system a supra linear response seems to exist. Nowadays, studies for determining the BTL origin being carried out. (Author)
Unusual Concentration Induced Antithermal Quenching of the Bi(2+) Emission from Sr2P2O7:Bi(2.).
Li, Liyi; Peng, Mingying; Viana, Bruno; Wang, Jing; Lei, Bingfu; Liu, Yingliang; Zhang, Qinyuan; Qiu, Jianrong
2015-06-15
The resistance of a luminescent material to thermal quenching is essential for the application in high power LEDs. Usually, thermal luminescence quenching becomes more and more serious as the activator concentration increases. Conversely, we found here that a red phosphor Sr2P2O7:Bi(2+) is one of the exceptions to this as we studied the luminescence properties at low (10-300 K) and high (300-500 K) temperatures. As Bi(2+) ions are incorporated into Sr2P2O7, they exhibit the emissions at ∼660 and ∼698 nm at room temperature and are encoded, hereafter, as Bi(1) and Bi(2) due to the substitutions for two different crystallographic sites Sr(1) and Sr(2), respectively, in the compound. However, they will not substitute for these sites equally. At lower dopant concentration, they will occupy preferentially Sr(2) sites partially due to size match. As the concentration increases, more Bi(2+) ions start to occupy the Sr(1) sites. This can be verified by the distinct changes of emission intensity ratio of Bi(2) to Bi(1). As environment temperature increases, the thermal quenching happens, but it can be suppressed by the Bi(2+) concentration increase. This becomes even more pronounced in Bi(2+) heavily doped sample as we decompose the broad emission band into separated Bi(1) and Bi(2) Gaussian peaks. For the sample, the Bi(1) emission at ∼660 nm even shows antithermal-quenching particularly at higher temperatures. This phenomenon is accompanied by the blue shift of the overall emission band and almost no changes of lifetimes. A mechanism is proposed due to volume expansion of the unit cell, the increase of Bi(1) content, and temperature dependent energy transfer between Bi(2) and Bi(1). This work helps us better understand the complex luminescent behavior of Bi(2+) doped materials, and it will be helpful to design in the future the heavily doped phosphor for WLEDs with even better resistance to thermal quenching.
Freire, Eleonora; Vega, Daniel R; Baggio, Ricardo
2010-06-01
Diaquabis[dihydrogen 1-hydroxy-2-(imidazol-3-ium-1-yl)ethylidene-1,1-diphosphonato-kappa(2)O,O']magnesium(II), [Mg(C(5)H(9)N(2)O(7)P(2))(2)(H(2)O)(2)], consists of isolated dimeric units built up around an inversion centre and tightly interconnected by hydrogen bonding. The Mg(II) cation resides at the symmetry centre, surrounded in a rather regular octahedral geometry by two chelating zwitterionic zoledronate(1-) [or dihydrogen 1-hydroxy-2-(imidazol-3-ium-1-yl)ethylidene-1,1-diphosphonate] anions and two water molecules, in a pattern already found in a few reported isologues where the anion is bound to transition metals (Co, Zn and Ni). catena-Poly[[aquacalcium(II)]-mu(3)-[hydrogen 1-hydroxy-2-(imidazol-3-ium-1-yl)ethylidene-1,1-diphosphonato]-kappa(5)O:O,O':O',O''], [Ca(C(5)H(8)N(2)O(7)P(2))(H(2)O)](n), consists instead of a Ca(II) cation in a general position, a zwitterionic zoledronate(2-) anion and a coordinated water molecule. The geometry around the Ca(II) atom, provided by six bisphosphonate O atoms and one water ligand, is that of a pentagonal bipyramid with the Ca(II) atom displaced by 0.19 A out of the equatorial plane. These Ca(II) coordination polyhedra are ;threaded' by the 2(1) axis so that successive polyhedra share edges of their pentagonal basal planes. This results in a strongly coupled rhomboidal Ca(2)-O(2) chain which runs along [010]. These chains are in turn linked by an apical O atom from a -PO(3) group in a neighbouring chain. This O-atom, shared between chains, generates strong covalently bonded planar arrays parallel to (100). Finally, these sheets are linked by hydrogen bonds into a three-dimensional structure. Owing to the extreme affinity of zoledronic acid for bone tissue, in general, and with calcium as one of the major constituents of bone, it is expected that this structure will be useful in modelling some of the biologically interesting processes in which the drug takes part.
Directory of Open Access Journals (Sweden)
Kasper S. Kjær
2017-07-01
Full Text Available We have used femtosecond resolution UV-visible and Kβ x-ray emission spectroscopy to characterize the electronic excited state dynamics of [Fe(bpy2(CN2], where bpy=2,2′-bipyridine, initiated by metal-to-ligand charge transfer (MLCT excitation. The excited-state absorption in the transient UV-visible spectra, associated with the 2,2′-bipyridine radical anion, provides a robust marker for the MLCT excited state, while the transient Kβ x-ray emission spectra provide a clear measure of intermediate and high spin metal-centered excited states. From these measurements, we conclude that the MLCT state of [Fe(bpy2(CN2] undergoes ultrafast spin crossover to a metal-centered quintet excited state through a short lived metal-centered triplet transient species. These measurements of [Fe(bpy2(CN2] complement prior measurement performed on [Fe(bpy3]2+ and [Fe(bpy(CN4]2− in dimethylsulfoxide solution and help complete the chemical series [Fe(bpyN(CN6–2N]2N-4, where N = 1–3. The measurements confirm that simple ligand modifications can significantly change the relaxation pathways and excited state lifetimes and support the further investigation of light harvesting and photocatalytic applications of 3d transition metal complexes.
López-Rayo, Sandra; Hernández, Diana; Lucena, Juan J; Escudero, Rosa; Gómez-Gallego, Mar; Sierra, Miguel A
2010-07-14
Iron chelates analogous to o,o-EDDHA/Fe(3+) are the fertilizers chosen to treat iron chlorosis in plants growing on calcareous soil. The isomer o,p-EDDHA/Fe(3+) presents less stability but faster assimilation by the plant than o,o-EDDHA/Fe(3+), because only five coordinating groups are able to complex Fe(3+). The new chelating agent 2-(2-((2-hydroxybenzyl)amino)ethylamino)-2-(2-hydroxyphenyl)acetic acid (DCHA) has been synthesized to obtain an iron fertilizer with intermediate stability between o,o-EDDHA/Fe(3+) and o,p-EDDHA/Fe(3+) and with fast assimilation. Its synthesis has been done starting from phenol, N-acetylethylendiamine, glyoxylic acid, and NaOH in a three-step sequence. The purity of the DCHA chelating agent, its protonation, and Ca(2+), Mg(2+), Fe(3+), and Cu(2+) stability constants, together with its ability to maintain iron in solution in different agronomic conditions, have been determined. The results indicate that the chelate DCHA/Fe(3+) has intermediate stability between those of o,o-EDDHA/Fe(3+) and o,p-EDDHA/Fe(3+) complexes and that it is capable of maintaining the Fe(3+) in agronomic conditions. This new chelating agent may be effective in correcting iron chlorosis in plants.
Regulated release of Ca2+ from respiring mitochondria by Ca2+/2H+ antiport.
Fiskum, G; Lehninger, A L
1979-07-25
Simultaneous measurements of oxygen consumption and transmembrane transport of Ca2+, H+, and phosphate show that the efflux of Ca2+ from respiring tightly coupled rat liver mitochondria takes place by an electroneutral Ca2+/2H+ antiport process that is ruthenium red-insensitive and that is regulated by the oxidation-reduction state of the mitochondrial pyridine nucleotides. When mitochondrial pyridine nucleotides are kept in a reduced steady state, the efflux of Ca2+ is inhibited; when they are in an oxidized state, Ca2+ efflux is activated. These processes were demonstrated by allowing phosphate-depleted mitochondria respiring on succinate in the presence of rotenone to take up Ca2+ from the medium. Upon subsequent addition of ruthenium red to block Ca2+ transport via the electrophoretic influx pathway, and acetoacetate, to bring mitochondrial pyridine nucleotides into the oxidized state, Ca2+ efflux and H+ influx ensued. The observed H+ influx/Ca2+ efflux ratio was close to the value 2.0 predicted for the operation of an electrically neutral Ca2+/2H+ antiport process.
Optical properties of ZrO2, SiO2 and TiO2-SiO2 xerogels and coatings doped with Eu3+ and Eu2+
Directory of Open Access Journals (Sweden)
Gonçalves Rogéria R.
1999-01-01
Full Text Available Eu3+ doped bulk monoliths and thin films were obtained by sol-gel methods in the ZrO2, SiO2 and SiO2-TiO2 systems. Eu3+ 5D0 ® 7FJ emission and decay time characteristics were measured during the entire experimental preparation route from the initial sol to the final xerogels. The crystalline phases identified were tetragonal ZrO2 and mixtures of rutile and anatase TiO2 at high temperature treatments in bulk samples. Good quality thin films were obtained for all systems by dip-coating optical glasses (Schott BK270. The same spectroscopic features were observed either for the bulk monoliths or the films. By appropriate heat treatments under H2 atmosphere Eu2+ containing samples could be obtained in the SiO2-TiO2 system.
DEFF Research Database (Denmark)
Berg, Rolf W.; Thorup, Niels
2005-01-01
Reactions between solid ZnO and molten Na2S2O7 or K2S2O7 at 500 are shown by Raman spectroscopy to be 1:1 reactions leading to solns. By lowering the temp. of the soln. melts, colorless crystals form. Raman spectra of the crystals are given and tentatively assigned. Crystal structures of the mon...... the three-dimensional network of the M2Zn(SO4)2 structures. Bond distances and angles compare well with literature values. Empirical correlations between S-O bond distances and av. O-S-O bond angles follow a previously found trend....
DEFF Research Database (Denmark)
Skøt, Leif
1983-01-01
for N2 reduction, is often stated as the relative efficiency (1-H2/C2H2). This factor varied significantly (P 2 and N2, expressed as the H2/N2 ratio, was independent of plant age, however. This discrepancy and the observation......The quantitative relationship between C2H2 reduction, H2 evolution and 15N2 fixation was investigated in excised root nodules from pea plants (Pisum sativum L. cv. Bodil) grown under controlled conditions. The C2H2/N2 conversion factor varied from 3.31 to 5.12 between the 32nd and the 67th day...... after planting. After correction for H2 evolution in air, the factor (C2H2-H2)/N2 decreased to values near the theoretical value 3, or in one case to a value significantly (P 2 production but used...
DEFF Research Database (Denmark)
Meunier, H.; Pagsberg, Palle Bjørn; Sillesen, A.
1996-01-01
studied by monitoring the decay of NH2 and the simultaneous formation of N2O and NO by time-resolved infrared diode laser spectroscopy. The decay rate of NH2 was studied as a function of NO2 concentration to obtain an overall rate constant k(NH2 + NO2) = (1.35 +/- 0.15) X 10(-11) molecule(-1) cm(3) s(-1...
Photodriven [2]rotaxane-[2]catenane interconversion.
Tron, Arnaud; Jacquot de Rouville, Henri-Pierre; Ducrot, Aurélien; Tucker, James H R; Baroncini, Massimo; Credi, Alberto; McClenaghan, Nathan D
2015-02-18
A [2]rotaxane, whose thread component comprises a central dibenzylammonium group and 9-alkoxyanthracene stoppers and is hosted by a 24-dibenzo-8-crown bead, undergoes an efficient photocatenation step resulting in a [2]rotaxane-to-[2]catenane topology interconversion via a fully reversible [4π+4π] photocyclomerization of terminal anthracene groups.
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Zouaoui Setifi
2015-05-01
Full Text Available In 2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-ethoxyprop-2-en-1-ide, C10H9N2+·C9H5N4O−, (I, the ethyl group in the anion is disordered over two sets of atomic sites with occupancies 0.634 (9 and 0.366 (9, and the dihedral angle between the ring planes in the cation is 2.11 (7°. The two independent C(CN2 groups in the anion make dihedral angles of 10.60 (6 and 12.44 (4° with the central propenide unit, and the bond distances in the anion provide evidence for extensive electronic delocalization. In bis(2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-(dicyanomethylenepropane-1,3-diide [alternative name bis(2,2′-bipyridin-1-ium tris(dicyanomethylenemethanediide], 2C10H9N2+·C10N62− (II, the dihedral angles between the ring planes in the two independent cations are 7.7 (2 and 10.92 (17°. The anion exhibits approximate C3 symmetry, consistent with extensive electronic delocalization, and the three independent C(CN2 groups make dihedral angles of 23.8 (2, 27.0 (3 and 27.4 (2° with the central plane. The ions in (I are linked by an N—H...N hydrogen bond and the resulting ion pairs are linked by two independent C—H...N hydrogen bonds, forming a ribbon containing alternating R44(18 and R44(26 rings, where both ring types are centrosymmetric. The ions in (II are linked by two independent N—H...N hydrogen bonds and the resulting ion triplets are linked by a C—H...N hydrogen bond, forming a C21(7 chain containing anions and only one type of cation, with the other cation linked to the chain by a further C—H...N hydrogen bond.
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Zhaojun Yu
2015-09-01
Full Text Available In the title polymeric complex, {[CoSr(C7H3NO42(H2O6]·2H2O}n, the CoII ion, which is situated on a crystallographic centre of inversion, is six-coordinated by two O atoms and two N atoms from two pyridine-2,4-dicarboxylate (pydc2− ligands and two terminal water molecules in a slightly distorted octahedral geometry, to form a trans-[Co(pydc2(H2O2]2− unit. The SrII ion, situated on a C2 axis, is coordinated by four O atoms from four pydc2− ligands and four water molecules. The coordination geometry of the SrII atom can be best described as a distorted dodecahedron. Each SrII ion bridges four [Co(pydc2(H2O2]2− units by four COO− groups of four pydc2− ligands to form a three-dimensional network structure. Two additional solvent water molecules are observed in the crystal structure and are connected to the three-dimensional coordination polymer by O—H...O hydrogen bonds. Further intra- and intermolecular O—H...O hydrogen bonds consolidate the overall structure.
International Nuclear Information System (INIS)
Wilson, Aaron D.; Miller, Alexander J.M.; DuBois, Daniel L.; Labinger, Jay A.; Bercaw, John E.
2011-01-01
Thermodynamic studies of a series of (H2Rh(PP)2)+ and (HRh(PP)2(CH3CN))2+ complexes have been carried out in acetonitrile. Seven different diphosphine (PP) ligands were selected to allow variation of the electronic properties of the ligand substituents, the cone angles, and the natural bite angles (NBAs). Oxidative addition of H2 to (Rh(PP)2)+ complexes is favored by diphosphine ligands with large NBAs, small cone angles, and electron donating substituents, with the NBA being the dominant factor. Large pKa values for (HRh(PP)2(CH3CN))2+ complexes are favored by small ligand cone angles, small NBAs, and electron donating substituents with the cone angles playing a major role. The hydride donor abilities of (H2Rh(PP)2)+ complexes increase as the NBAs decrease, the cone angles decrease, and the electron donor abilities of the substituents increase. These results indicate that if solvent coordination is involved in hydride transfer or proton transfer reactions, the observed trends can be understood in terms of a combination of two different steric effects, NBAs and cone angles, and electron-donor effects of the ligand substituents.
Crystal structure of ethyl 2-(diethoxyphosphoryl-2-(2,3,4-trimethoxyphenylacetate
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Moritz Schubert
2014-09-01
Full Text Available The title compound, C17H27O8P, was prepared by Michaelis–Arbuzov reaction of ethyl 2-bromo-2-(2,3,4-trimethoxyphenylacetate and triethyl phosphite. Such compounds rarely crystallize, but single crystals were recovered after the initial oil was left for approximately 10 years. The bond angle of the sp3-hybridized C atom connecting the benzene derivative with the phospho unit is widened marginally [112.5 (2°]. The terminal P—O bond length of 1.464 (2 Å clearly indicates a double bond, whereas the two O atoms of the ethoxy groups connected to the phosphorous atom have bond lengths of 1.580 (2 Å and 1.581 (3 Å. The three methoxy groups emerge out of the benzene-ring plane due to steric hindrance [C—C—O—C torsion angles = −179.9 (3°, −52.9 (4° and 115.3 (4°]. In the crystal, inversion dimers linked by pairs of C—H...O=P hydrogen bonds generate R22(14 loops. The chosen crystal was modelled as a non-merohedral twin.
Potassium (2,2′-bipyridine-κ2 N,N′)bis(carbonato-κ2 O,O′)cobaltate(III) dihydrate
Wang, Jian-Fei; Lin, Jian-Li
2010-01-01
In the title compound, K[Co(CO3)2(C10H8N2)]·2H2O, the Co(III) atom is coordinated by two bipyridine N atoms and four O atoms from two bidentate chelating carbonate anions, and thus adopts a distorted octahedral N2O4 environment. The [Co(bipy)(CO3)2]− (bipy is 2,2′-bipyridine) units are stacked along [100] via π–π stacking interactions, with interplanar distances between the bipyridine rings of 3.36 (4) and 3.44 (6) Å, forming chains. Classical O—H⋯O hydrogen-bonding interactions link the chains, forming channels along (100) in which the K+ ions reside and leading to a three-dimensional supramolecular architecture. PMID:21587447
Chen, Di-Ming; Sun, Chun-Xiao; Zhang, Nan-Nan; Si, Huan-Huan; Liu, Chun-Sen; Du, Miao
2018-03-05
As a modulatable class of porous crystalline materials, metal-organic frameworks (MOFs) have gained intensive research attention in the domain of gas storage and separation. In this study, we report on the synthesis and gas adsorption properties of two robust MOFs with the general formula [Co 3 (μ 3 -OH)(cpt) 3 Co 3 (μ 3 -OH)(L) 3 (H 2 O) 9 ](NO 3 ) 4 (guests) n [L = 3-amino-1,2,4-triazole (1) and 3,5-diamino-1,2,4-triazole (2); Hcpt = 4-(4-carboxyphenyl)-1,2,4-triazole], which show the same pacs topology. Both MOFs are isostructural to each other and show MIL-88-type frameworks whose pore spaces are partitioned by different functionlized trinuclear 1,2,4-triazolate-based clusters. The similar framework components with different amounts of functional groups make them an ideal platform to permit a systematic gas sorption/separation study to evaluate the effects of distinctive parameters on the C 2 H 2 uptake and separation performance. Because of the presence of additional amido groups, the MOF 2 equipped with a datz-based cluster (Hdatz = 3,5-diamino-1,2,4-triazole) shows a much improved C 2 H 2 uptake capacity and separation performance over that of the MOF 1 equipped with atz-based clusters (Hatz = 3-amino-1,2,4-triazole), although the surface area of the MOF 1 is almost twice than that of the MOF 2. Moreover, the high density of open metal sites, abundant free amido groups, and charged framework give the MOF 2 an excellent C 2 H 2 separation performance, with ideal adsorbed solution theory selectivity values reaching up to 11.5 and 13 for C 2 H 2 /C 2 H 4 (1:99) and C 2 H 2 /CO 2 (50:50) at 298 K and 1 bar, showing potential for use in natural gas purification.
2-Aminobenzoic acid–4-[2-(pyridin-4-ylethyl]pyridine (2/1
Directory of Open Access Journals (Sweden)
Hadi D. Arman
2013-11-01
Full Text Available The asymmetric unit of the title co-crystal, C12H12N2·2C7H7NO2, comprises a centrosymmetric 4-[2-(pyridin-4-ylethyl]pyridine molecule and a 2-aminobenzoic acid molecule in a general position. The acid has a small twist between the carboxylic acid residue and the ring [dihedral angle = 7.13 (6°] despite the presence of an intramolecular N—H...O(carbonyl hydrogen bond. Three-molecule aggregates are formed via O—H...N(pyridyl hydrogen bonds, and these are connected into supramolecular layers in the bc plane by N—H...O(carbonyl hydrogen bonds and π–π interactions between pyridine and benzene rings [inter-centroid distance = 3.6332 (9 Å]. Layers are connected along the a axis by weak π–π interactions between benzene rings [3.9577 (10 Å].
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Ghulam Fareed
2012-05-01
Full Text Available Novel 7-{[2-(4-hydroxyphenylmethylidene]amino}-1,3-thiazol-4-yl-2-(methoxyiminoacetyl]amino}-3-{[(2-methyl-5,6-dioxo-1,2,5,6-tetrahydro-1,2,4-triazin-3-ylsulfanyl]methyl}-8-oxo-5-thia-1azabicyclo [4.2.0]oct-2-ene-2-carboxylic acid was prepared by condensation of ceftriaxone disodium (1 with 4-hydroxybenzaldehyde (2 in ethanol under reflux conditions for 3–4 h. The structure of synthesized compound was elucidated using LCMS, 1H-NMR, and CHN techniques.
Neuroprotective 2-(2-phenylethyl)chromones of Imperata cylindrica.
Yoon, Jeong Seon; Lee, Mi Kyeong; Sung, Sang Hyun; Kim, Young Choong
2006-02-01
Bioactivity-guided fractionation of the methanolic extract of the rhizomes of Imperata cylindrica afforded a new compound, 5-hydroxy-2-(2-phenylethyl)chromone (1), together with three known compounds, 5-hydroxy-2-[2-(2-hydroxyphenyl)ethyl]chromone (2), flidersiachromone (3), and 5-hydroxy-2-styrylchromone (4). Among these four compounds, 1 and 2 showed significant neuroprotective activity against glutamate-induced neurotoxicity in primary cultures of rat cortical cells.
International Nuclear Information System (INIS)
Tan, Yee Seng; Halim, Siti Nadiah Abdul; Tiekink, Edward R.T.; Sunway Univ., Bandar Sunway
2016-01-01
Crystallization of Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 from ethanol yields the coordination polymer [{Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 }.EtOH] ∞ (1) within 3 h. When the solution is allowed to stand for another hour, the needles begin to dissolve and prisms emerge of the supramolecular isomer (SI), binuclear {Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 } 2 .2EtOH (2). These have been fully characterized spectroscopically and by X-ray crystallography. Polymeric 1 has 2-fold symmetry and features dithiocarbamate ligands coordinating two octahedral Cd atoms in a μ 2 κ 2 -tridentate mode. Binuclear 2 is centrosymmetric with two ligands being μ 2 κ 2 -tridentate as for 1 but the other two being κ 2 -chelating leading to square pyramidal geometries. The conversion of the kinetic crystallization product, 1, to thermodynamic 2 is irreversible but transformations mediated by recrystallization (ethanol and acetonitrile) to related literature SI species, namely coordination polymer [{Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 } 3 .MeCN] ∞ and binuclear {Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 } 2 .2H 2 O.2MeCN, are demonstrated, some of which are reversible. Three other crystallization outcomes are described whereby crystal structures were obtained for the 1:2 co-crystal {Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 } 2 :2[3-(propan-2-yl)-1,3-oxazolidine-2-thione] (3), the salt co-crystal [iPrNH 2 (CH 2 CH 2 OH)] 4 [SO 4 ] 2 {Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 } 2 (4) and the salt [iPrNH 2 (CH 2 CH 2 OH)]{Cd[S 2 CN(iPr)CH 2 CH 2 OH] 3 } (5). These arise as a result of decomposition/oxidation of the dithiocarbamate ligands. In each of 3 and 4 the binuclear {Cd[S 2 CN(iPr)CH 2 CH 2 OH] 2 } 2 SI, as in 2, is observed strongly suggesting a thermodynamic preference for this form.
Three-dimensional WS2 nanosheet networks for H2O2 produced for cell signaling
Tang, Jing; Quan, Yingzhou; Zhang, Yueyu; Jiang, Min; Al-Enizi, Abdullah M.; Kong, Biao; An, Tiance; Wang, Wenshuo; Xia, Limin; Gong, Xingao; Zheng, Gengfeng
2016-03-01
Hydrogen peroxide (H2O2) is an important molecular messenger for cellular signal transduction. The capability of direct probing of H2O2 in complex biological systems can offer potential for elucidating its manifold roles in living systems. Here we report the fabrication of three-dimensional (3D) WS2 nanosheet networks with flower-like morphologies on a variety of conducting substrates. The semiconducting WS2 nanosheets with largely exposed edge sites on flexible carbon fibers enable abundant catalytically active sites, excellent charge transfer, and high permeability to chemicals and biomaterials. Thus, the 3D WS2-based nano-bio-interface exhibits a wide detection range, high sensitivity and rapid response time for H2O2, and is capable of visualizing endogenous H2O2 produced in living RAW 264.7 macrophage cells and neurons. First-principles calculations further demonstrate that the enhanced sensitivity of probing H2O2 is attributed to the efficient and spontaneous H2O2 adsorption on WS2 nanosheet edge sites. The combined features of 3D WS2 nanosheet networks suggest attractive new opportunities for exploring the physiological roles of reactive oxygen species like H2O2 in living systems.Hydrogen peroxide (H2O2) is an important molecular messenger for cellular signal transduction. The capability of direct probing of H2O2 in complex biological systems can offer potential for elucidating its manifold roles in living systems. Here we report the fabrication of three-dimensional (3D) WS2 nanosheet networks with flower-like morphologies on a variety of conducting substrates. The semiconducting WS2 nanosheets with largely exposed edge sites on flexible carbon fibers enable abundant catalytically active sites, excellent charge transfer, and high permeability to chemicals and biomaterials. Thus, the 3D WS2-based nano-bio-interface exhibits a wide detection range, high sensitivity and rapid response time for H2O2, and is capable of visualizing endogenous H2O2 produced in
Asaji, Tetsuo
2018-05-01
Temperature dependences of 1H NMR as well as 35Cl NQR spin-lattice relaxation times T1 were investigated of a ferroelectric molecular adduct with Tc = 323 K, in which 1,4-diazabicyclo[2.2.2]octane (DABCO) is sandwiched between two 2-chlorobenzoic acid (2-ClBA). The NQR frequencies clearly show that proton transfer from 2-ClBA to DABCO is occurred and the molecular adduct consists of diprotonated DABCO cation and two 2-chlorobenzoate anions. The correlation time of reorientational motion of the diprotonated DABCO molecule was determined as a function of temperature. The activation energy Ea of the motion was estimated as 22 kJ mol-1 below Tc. The steep decrease of the NQR T1 with Ea = 50 kJ mol-1, observed above ca. 280 K in the ferroelectric phase, suggests a slow fluctuation of electric field gradient at chlorine nucleus.
Energy Technology Data Exchange (ETDEWEB)
Abraham, T.W.; Leete, Edward [Minnesota Univ., Minneapolis, MN (United States). Dept. of Chemistry
1996-05-01
2-Ethoxy-1-methyl-5-pyrrolidinone (1) was reacted with ethyl [3,4-{sup 13}C{sub 2}]-acetoacetate (2) in the presence of TiCl{sub 4} to give ethyl [3,4-{sup 13}C{sub 2}]-2-(1`-methyl-5`-oxo-2`-pyrrolidinyl)-3-oxobutanoate (3) in 85% yield. Decarboethoxylation of ethyl [3,4-{sup 13}C{sub 2}]-2-(1`-methyl-5`-oxo-2`-pyrrolidinyl)-3-oxobutan-oate (3) was accomplished using NaCl and H{sub 2}O in DMSO to give (R,S)-[2,3-{sup 13}C{sub 2}]-1-(1`-methyl-5`-oxo-2`-pyrrolidinyl)propan-2-o ne (4) in 91% yield. Protection of the ketone as a ketal (ethylene glycol, H{sup +}), followed by reduction of the amide to the amine using LiAlH{sub 4} and subsequent deprotection of the ketal gave (R,S)-[2,3-{sup 13}C{sub 2}]-1-(1`-methyl-2`-pyrrolidinyl)propan-2-one ((R,s)-[2`, 3`-{sup 13}C{sub 2}]Hygrine) (8) in 78% yield. (61% overall yield from ethyl [3,4-{sup 13}C{sub 2}]acetoacetate). (Author).
Directory of Open Access Journals (Sweden)
Pavel K. Mykhailiuk
2015-01-01
Full Text Available A one-pot reaction between C2F5CH2NH2·HCl, NaNO2 and electron-deficient alkynes gives C2F5-substituted pyrazoles in excellent yields. The transformation smoothly proceeds in dichloromethane/water, tolerates the presence of air, and requires no purification of products by column chromatography. Mechanistically, C2F5CH2NH2·HCl and NaNO2 react first in water to generate C2F5CHN2, that participates in a [3 + 2] cycloaddition with electron-deficient alkynes in dichloromethane.
Crystallization behavior of (1 - x)Li2O.xNa2O.Al2O3.4SiO2 glasses
International Nuclear Information System (INIS)
Wang, Moo-Chin; Cheng, Chih-Wei; Chang, Kuo-Ming; Hsi, Chi-Shiung
2010-01-01
The crystallization behavior of the (1 - x)Li 2 O.xNa 2 O.Al 2 O 3 .4SiO 2 glasses has been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron diffraction (ED) and energy dispersive spectroscopy (EDS). The crystalline phase was composed of β-spodumene. The isothermal crystallization kinetics of β-spodumene from the (1 - x)Li 2 O.xNa 2 O.Al 2 O 3 .4SiO 2 glasses has also been studied by a quantitative X-ray diffraction method. The activation energy of β-spodumene formation decreases from 359.2 to 317.8 kJ/mol when the Na 2 O content increases from 0 to 0.4 mol and it increases from 317.8 to 376.9 kJ/mol when the Na 2 O content increases from 0.4 to 0.6 mol. The surface nucleation and plate-like growth were dominant in the crystallization of the (1 - x)Li 2 O.xNa 2 O.Al 2 O 3 .4SiO 2 glasses.
Samuels, Shanelle; Gordon, Iouli; Tan, Yan
2018-01-01
HITRAN1,2 is a compilation of spectroscopic parameters that a variety of computer codes use to predict and simulate the transmission and emission of light in planetary atmospheres. The goal of this project is to add to the potential of the HITRAN database towards the exploration of the planetary atmospheres by including parameters describing broadening of spectral lines by H2, CO2, and He. These spectroscopic data are very important for the study of the hydrogen and helium-rich atmospheres of gas giants as well as rocky planets with volcanic activities, including Venus and Mars, since their atmospheres are dominated by CO2. First step in this direction was accomplished by Wilzewski et al.3 where this was done for SO2, NH3, HF, HCl, OCS and C2H2. The molecules investigated in this work were CO2, N2O, H2CO, HCN and H2S. Line-broadening coefficients, line shifts and temperature-dependence exponents for transitions of these molecules perturbed by H2, CO2 and He have been assembled from available peer-reviewed experimental and theoretical sources. The data was evaluated and the database was populated with these data and their extrapolations/interpolations using semi-empirical models that were developed to this end.Acknowledgements: Financial support from NASA PDART grant NNX16AG51G and the Smithsonian Astrophysical Observatory Latino Initiative Program from the Latino Initiatives Pool, administered by the Smithsonian Latino Center is gratefully acknowledged.References: 1. HITRAN online http://hitran.org/2. Gordon, I.E., Rothman, L.S., Hill, C., Kochanov, R.V., Tan, Y., et al., 2017. The HITRAN2016 Molecular Spectroscopic Database. J. Quant. Spectrosc. Radiat. Transf. doi:10.1016/j.jqsrt.2017.06.0383. Wilzewski, J.S., Gordon, I.E., Kochanov, R. V., Hill, C., Rothman, L.S., 2016. H2, He, and CO2 line-broadening coefficients, pressure shifts and temperature-dependence exponents for the HITRAN database. Part 1: SO2, NH3, HF, HCl, OCS and C2H2. J. Quant. Spectrosc. Radiat
2016-09-01
chromatography using a thermal conductivity detector (GC-TCD). Table 1. Sample Information for GP and DMCP Chemical Name Mole Fraction Purity...Proving Ground, MD, 1983; UNCLASSIFIED Report (ADC033491). 23. Weast, R.C. CRC Handbook of Chemistry and Physics, 53rd ed.; CRC Press: Boca Raton, FL...gas chromatography GD pinacolyl methylphosphonofluoridate GF cyclohexyl methylphosphonofluoridate GP 2,2-dimethylcyclopentyl
Arjun, U.; Kumar, Vinod; Anjana, P. K.; Thirumurugan, A.; Sichelschmidt, J.; Mahajan, A. V.; Nath, R.
2017-05-01
We present the synthesis and a detailed investigation of structural and magnetic properties of polycrystalline NH4[(V2O3)2(4,4'-b p y ) 2(H2PO4) (PO4)2] .0.5 H2O by means of x-ray diffraction, magnetic susceptibility, electron spin resonance, and 31P nuclear magnetic resonance measurements. Temperature-dependent magnetic susceptibility could be described well using a weakly coupled spin-1/2 dimer model with an excitation gap Δ /kB≃26.1 K between the singlet ground state and triplet excited states and a weak interdimer exchange coupling J'/kB≃4.6 K. A gapped chain model also describes the data well with a gap of about 20 K. The electron spin resonance intensity as a function of temperature traces the bulk susceptibility nicely. The isotropic Landé g factor is estimated to be about g ≃1.97 , at room temperature. We are able to resolve the 31P NMR signal as coming from two inequivalent P sites in the crystal structure. The hyperfine coupling constant between 31P nucleus and V4 + spins is calculated to be Ahf(1 ) ≃2963 Oe/μB and Ahf(2 ) ≃1466 Oe/μB for the P(1) and P(2) sites, respectively. Our NMR shift and spin-lattice relaxation rate for both the 31P sites show an activated behavior at low temperatures, further confirming the singlet ground state. The estimated value of the spin gap from the NMR data measured in an applied field of H =9.394 T is consistent with the gap obtained from the magnetic susceptibility analysis using the dimer model. Because of a relatively small spin gap, NH4[(V2O3)2(4,4'-b p y ) 2(H2PO4) (PO4)2] .0.5 H2O is a promising compound for further experimental studies under high magnetic fields.
Plyusnin, Pavel E.; Makotchenko, Evgenia V.; Shubin, Yury V.; Baidina, Iraida A.; Korolkov, Ilya V.; Sheludyakova, Liliya A.; Korenev, Sergey V.
2015-11-01
Double complex salts of rhodium(III) and gold(III) of the composition [Au(en)2][Rh(NO2)6]·2H2O (1) and [Au(en)2][Rh(NO2)6] (2) have been prepared. Crystal structures of the compounds have been determined by single crystal X-ray diffraction. The compounds have been characterized by PXRD, IR, far-IR, CHN and DTA. The complexes have a layered structures. The presence of water in 1 makes the structure of the hydrated DCS less dense as compared to the anhydrous one. The environment of the cation and the anion in the two structures is the same, oxygen atoms of the nitro groups are involved in hydrogen bonds N-H⋯O, N⋯O distances being approximately the same. The structures of 1 and 2 are notable in having shortened contacts between the gold atoms and the oxygen atoms of the nitro groups of the neighboring complex anions. The thermal behavior of the complexes in a hydrogen atmosphere was investigated. The final product of thermolysis prepared at the temperature 600°C is a two-phase mixture of pure metallic gold and the solid solution Rh0.93Au0.07.
Color point tuning for (Sr,Ca,Ba)Si2O2N2:Eu2+ for white light LEDs
Bachmann, V.M.; Ronda, R.C.; Meijerink, A.; Oeckler, O.; Schnick, W.
2009-01-01
Color point tuning is an important challenge for improving white light LEDs. In this paper, the possibilities of color tuning with the efficient LED phosphor Sr1-x-y-zCaxBaySi2O2N2:Euz 2+ (0 e x, y e 1; 0.005 e z e 0.16) are investigated. The emission color can be tuned in two ways: by changing Eu2+
Multicomponent Biginelli's synthesis of 3,4-dihydropyrimidin-2(1H-ones promoted by SnCl2.2H2O
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Russowsky Dennis
2004-01-01
Full Text Available The ability of SnCl2.2H2O as catalyst to promote the Biginelli three-component condensation reaction from a diversity of aromatic aldehydes, ethyl acetoacetate and urea or thiourea is described. The reaction was carried out in acetonitrile or ethanol as solvents in neutral media and represents an improvement of the classical Biginelli protocol and an advantage in comparison with FeCl3.6H2O, NiCl2.6H2O and CoCl2.6H2O which were used with HCl as co-catalyst. The synthesis of 3,4-dihydropyrimidinones was achieved in good to excelent yields.