Building a Picture of Heteroborane Isomerisation: Synthesis and Characterisation of the 10-(Dialkyl- sulfane)-7,8-diphenyl-7,8-dicarba-nido-undecaboranes 7,8-Ph2-10-L-7,8-nido-C2B9H10 (L = SMe2, SMeEt, SEt2) and of Intermediate and Isomerised Products Arising from Metallation of the First of These

1999 ◽  
Vol 64 (6) ◽  
pp. 1013-1027 ◽  
Author(s):  
Shirley Dunn ◽  
Rhona M. Garrioch ◽  
Georgina M. Rosair ◽  
Lorraine Smith ◽  
Alan J. Welch
Keyword(s):  
Boron Atom ◽  
Experimental Information ◽  
Crystallographic Study

Three new, substituted, nido carboranes, 7,8-Ph2-10-(SMe2)-7,8-nido-C2B9H10 (1a), 7,8-Ph2-10- (SMeEt)-7,8-nido-C2B9H10 (1b) and 7,8-Ph2-10-(SEt2)-7,8-nido-C2B9H10 (1c) have been synthesised and characterised, including a crystallographic study of the first. Deprotonation of 1a followed by treatment with (MeCN)2(CO)2MoBr(η-C3H5) at 0 °C affords the non-icosahedral 1,2-Ph2-4-(SMe2)-5-(η-C3H5)-5,5-(CO)2-5,1,2-closo-MoC2B9H8 (2a), which on subsequent warming transforms into icosahedral 2,8-Ph2-5-(SMe2)-1-(η-C3H5)-1,1-(CO)2-1,2,8-closo- MoC2B9H8 (3a). It is argued that under the conditions of these rearrangements the B-S bond is likely to remain intact, and consequently that the identity of the SMe2-labelled boron atom in 3a affords useful experimental information on the course of the isomerisation.

Polymorphic phase transition of a membrane protein - analysis of continuous diffuse electron diffraction intensity

1986 ◽  
Vol 44 ◽  
pp. 166-167
Author(s):  
Douglas L. Dorset ◽  
Andrew K. Massalski
Keyword(s):  
Molecular Sieve ◽  
Three Dimensional ◽  
Pore Geometry ◽  
Two Dimensional ◽  
Diffraction Intensity ◽  
Polymorphic Phase Transition ◽  
E Coli ◽  
Crystallographic Study ◽  
Hexagonal Form ◽  
Polymorphic Forms

Matrix porin, the ompF gene product of E. coli, has been the object of a electron crystallographic study of its pore geometry in an attempt to understand its function as a membrane molecular sieve. Three polymorphic forms have been found for two-dimensional crystals reconstituted in phospholipid, two hexagonal forms with different lipid content and an orthorhombic form coexisting with and similar to the hexagonal form found after lipid loss. In projection these have been shown to retain the same three-fold pore triplet geometry and analyses of three-dimensional data reveal that the small hexagonal and orthorhombic polymorphs have similar structure as well as unit cell spacings.

Physico-Chemical Explanation of Blood Cell Adhesion in Thrombus Formation

1976 ◽  
Vol 36 (02) ◽  
pp. 430-440 ◽  
Author(s):  
A Marmur ◽  
E Ruckenstein ◽  
S. R Rakower
Keyword(s):  
Blood Cells ◽  
Thrombus Formation ◽  
Experimental Information ◽  
Deposition Surface ◽  
Physico Chemical ◽  
Quantitative Results ◽  
Energy Of Interaction ◽  
Induced Aggregation ◽  
Adhesion Of Platelets ◽  
Hydrodynamic Factors

SummaryA model is suggested which assumes that the rate of deposition of cells is determined both by hydrodynamic factors and by Brownian motion over the potential barrier caused by London and double-layer forces in the immediate vicinity of the deposition surface. The height of the barrier in the potential energy of interaction between blood cells and various surfaces is analyzed in relation to the physical properties of the cells, surfaces, and solutions. Based on this analysis, the adhesion of platelets to injured blood vessel walls and to non-biologic materials, the lack of adhesion of red blood cells under the same conditions, the mechanism of ADP induced aggregation and the interaction with blood flow are explained. The qualitative predictions of the model are substantiated by available experimental information. Quantitative results are presented in terms of a time constant, which typifies a period of contact with a surface, during which appreciable deposition occurs.

A Crystallographic Study of Bis[S-benzyl-5-bromo-2-oxoindolin-3-ylidenemethanehydrazonthioate] Disulfide Solvated with Dimethylsulfoxide

2012 ◽  
Vol 9 (2) ◽  
pp. 87
Author(s):  
Mohd Abdul Fatah Abdul Manan ◽  
M. Ibrahim M. Tahir ◽  
Karen A. Crouse ◽  
Fiona N.-F. How ◽  
David J. Watkin
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Solvent Molecule ◽  
Site Occupancy ◽  
Unit Cell Parameters ◽  
Intermolecular Hydrogen Bonds ◽  
Triclinic Space Group ◽  
Cell Parameters ◽  
Crystallographic Study ◽  
Thiol Form

The crystal structure of the title compound has been determined. The compound crystallized in the triclinic space group P -1, Z = 2, V = 1839 .42( 18) A3 and unit cell parameters a= 11. 0460( 6) A, b = 13 .3180(7) A, c=13. 7321 (8) A, a = 80.659(3 )0, b = 69 .800(3 )0 and g = 77 .007 (2)0 with one disordered dimethylsulfoxide solvent molecule with the sulfur and oxygen atoms are distributed over two sites; S101/S102 [site occupancy factors: 0.6035/0.3965] and 0130/0131 [site occupancy factor 0.3965/0.6035]. The C22-S2 l and C 19-S20 bond distances of 1. 779(7) A and 1. 788(8) A indicate that both of the molecules are connected by the disulfide bond [S20-S21 2.055(2) A] in its thiol form. The crystal structure reveals that both of the 5-bromoisatin moieties are trans with respect to the [S21-S20 and CI 9-Nl 8] and [S20-S21 and C22-N23] bonds whereas the benzyl group from the dithiocarbazate are in the cis configuration with respect to [S21-S20 and C19-S44] and [S20-S21 and C22-S36] bonds. The crystal structure is further stabilized by intermolecular hydrogen bonds of N9-H35···O16 formed between the two molecules and N28-H281 ···O130, N28-H281 ···O131 and C4 l-H4 l l ···O 131 with the solvent molecule.

EFFECT OF METALLIC FUEL NATURE ON COMBUSTION CHARACTERISTICS OF AMMONIUM PERCHLORATE / BINDER / METAL COMPOSITE SOLID PROPELLANTS

2020 ◽  
Author(s):  
V. A. Poryazov ◽  
◽  
O. G. Glotov ◽  
V. A. Arkhipov ◽  
G. S. Surodin ◽  
...  
Keyword(s):  
Ammonium Perchlorate ◽  
Combustion Process ◽  
Experimental Information ◽  
Combustion Characteristics ◽  
Transformer Oil ◽  
Metal Composite ◽  
Butadiene Rubber ◽  
Solid Propellants ◽  
Metallic Fuel ◽  
Composite Solid Propellants

The goal of this research is to obtain experimental information about combustion characteristics of the composite propellant containing various metallic fuels. The propellant formulations contained two fractions of ammonium perchlorate (64.6%), inert binder (19.7%) - butadiene rubber SKD plastized with transformer oil, and metal fuel (15.7% of aluminum ASD-4, ASD-6, Alex; boron; aluminum diboride; aluminum dodecaboride; some mixtures of above listed ingredients). Experimental information will be used further as a background to develop the physical and mathematical model of combustion process.

The Effect of The Using of Computer Games On Academic Success In Teaching English To 8th Grade Students

2019 ◽  
Author(s):  
Bulent Dos ◽  
Zeynep Sinem Balıkçıoğlu ◽  
Semih Şengel
Keyword(s):  
Academic Success ◽  
Computer Games ◽  
Experimental Information ◽  
Control Group ◽  
Traditional Teaching ◽  
National Education ◽  
8Th Grade ◽  
Post Test ◽  
Education Measurement ◽  
The One

<p>In this study, the effect of using computer games in an English teaching classof the 8th grade students in secondary school is investigated. A total of 112 8th grade students, 57 in the experimental group and 55 in the control group, participated in the study. Academic Achievement Tests prepared by Ministry of National Education, Measurement, Evaluation and Exam Services Department were used as pre-test and post-test. Eight of the games, which were prepared specifically for Grade 8 students, were used in the Experimental Information Network (EBA). Preliminary tests as covariant, final tests as dependent variables and applied to groups of teaching and traditional teaching were discussed as independent variables. According to the one-way covariance analysis (COVARIANCE) results, it was found that the game was more effective than traditional teaching and this effect was moderate. In addition, it was determined that 36% of the final test scores of the students learning the game were explained by the game.</p>

X-ray Crystallographic Study of Alkylammonium Anthracene-9-carboxylates as a Model for Fibrous Structure of Binary Anthracene Salt Gels

2004 ◽  
Vol 69 (6) ◽  
pp. 1292-1300 ◽  
Author(s):  
Tahahiro Tani ◽  
Kazuki Sada ◽  
Masatsugu Ayabe ◽  
Yuya Iwashita ◽  
Takanori Kishida ◽  
...  
Keyword(s):  
Alkyl Chain ◽  
Columnar Structure ◽  
Hydrogen Bond Network ◽  
One Dimensional ◽  
X Ray ◽  
Crystallographic Study ◽  
Alkylammonium Salts ◽  
Bond Network ◽  
Fibrous Assemblies ◽  
Long Alkyl Chain

Crystal structure of hexylammonium anthracene-9-carboxylate was investigated. The salt was arranged by a one-dimensional hydrogen bond network to form a columnar structure in the crystalline state. This columnar structure should be the model of fibrous assemblies in the organogels of anthracene-9-carboxylate alkylammonium salts having a long alkyl chain.

A preliminary crystallographic study of CDCP2 fromArabidopsis thaliana

2008 ◽  
Vol 64 (a1) ◽  
pp. C245-C246
Author(s):  
B.-C. Jeong ◽  
K.S. Yoo ◽  
J.S. Shin ◽  
H.K. Song
Keyword(s):  
Crystallographic Study

scholarly journals The NUMEN Project: Toward New Experiments with High-Intensity Beams

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 72
Author(s):  
Clementina Agodi ◽  
Antonio D. Russo ◽  
Luciano Calabretta ◽  
Grazia D’Agostino ◽  
Francesco Cappuzzello ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
High Intensity ◽  
Particle Physics ◽  
Nuclear Physics ◽  
High Sensitivity ◽  
Experimental Information ◽  
Double Charge Exchange ◽  
Superconducting Cyclotron ◽  
Double Charge

The search for neutrinoless double-beta (0νββ) decay is currently a key topic in physics, due to its possible wide implications for nuclear physics, particle physics, and cosmology. The NUMEN project aims to provide experimental information on the nuclear matrix elements (NMEs) that are involved in the expression of 0νββ decay half-life by measuring the cross section of nuclear double-charge exchange (DCE) reactions. NUMEN has already demonstrated the feasibility of measuring these tiny cross sections for some nuclei of interest for the 0νββ using the superconducting cyclotron (CS) and the MAGNEX spectrometer at the Laboratori Nazionali del Sud (LNS.) Catania, Italy. However, since the DCE cross sections are very small and need to be measured with high sensitivity, the systematic exploration of all nuclei of interest requires major upgrade of the facility. R&D for technological tools has been completed. The realization of new radiation-tolerant detectors capable of sustaining high rates while preserving the requested resolution and sensitivity is underway, as well as the upgrade of the CS to deliver beams of higher intensity. Strategies to carry out DCE cross-section measurements with high-intensity beams were developed in order to achieve the challenging sensitivity requested to provide experimental constraints to 0νββ NMEs.

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