365 research outputs found
Charge-induced spin polarization in non-magnetic organic molecule Alq
Electrical injection in organic semiconductors is a key prerequisite for the
realization of organic spintronics. Using density-functional theory
calculations we report the effect of electron transfer into the organic
molecule Alq. Our first-principles simulations show that electron injection
spontaneously spin-polarizes non-magnetic Alq with a magnetic moment
linearly increasing with induced charge. An asymmetry of the Al--N bond lengths
leads to an asymmetric distribution of injected charge over the molecule. The
spin-polarization arises from a filling of dominantly the nitrogen
orbitals in the molecule's LUMO together with ferromagnetic coupling of the
spins on the quinoline rings.Comment: Accepted 4 pages 4 figure
Bis[benzyl N′-(3-phenylprop-2-enylidene)hydrazinecarbodithioato-κ2 N′,S]zinc(II)
In the title ZnII complex, [Zn(C17H15N2S2)2], the ZnII atom lies on a twofold rotation axis. It exists in a tetrahedral geometry, chelated by two deprotonated Schiff base ligands. The dihedral angle between each ligand is 71.48 (8)°. Molecules are connected by weak C—H⋯S intermolecular interactions into chains along the c axis. The crystal structure is further stabilized by C—H⋯π interactions involving the phenyl ring of the 3-phenylprop-2-enylidene unit
Benzyl 3-[(E,E)-3-phenylprop-2-enylidene]dithiocarbazate
The title compound, C17H16N2S2, a dithiocarbazate derivative, adopts an EE configuration with respect to the C=C and C=N double bonds of the propenylidine group. The 3-phenylprop-2-enylidene and dithiocarbazate fragments lie essentially in the same plane, with a maximum deviation from that plane of 0.074 (2) Å, while the dihedral angle between the 3-phenylprop-2-enylidene and the benzyl group is 77.78 (7)°. In the crystal structure, molecules are linked by an N—H⋯S hydrogen bond and a weak C—H⋯S interaction involving the terminal thione S atom, forming dimers that are arranged into sheets parallel to the bc plane. The crystal structure is also stabilized by C—H⋯π interactions
Microstructural damage evaluation in Ni-based superalloy gas turbine blades by fractal analysis
Ni-based superalloys are used as turbine disc and blade material in which creep, fatigue and creep-fatigue are the important damage mechanisms. Mechanical properties of these alloys depend upon the amounts of gamma-gamma-prime present in the microstructure as well as precipitation of carbides along the grain boundaries. The distribution of gamma-prime depends on the chemical composition, operating temperature and the length of service exposure. During service exposure, as damage accumulates progressively, the morphological characteristics of microstructure change which needs to be assessed using metallographic technique. Conventionally, the extent of damage resulting in deterioration of mechanical properties is quantified by hardness measurement. The variation in hardness is correlated with the morphological features in the metalographic images by identifying precipitation of carbides, presence of cuboidal gamma-prime and the structural changes that occur in the matrix. In this paper, we report fractal dimensions of the insitu metallographic images which can correlate the progressive damage accumulation at various locations of the blades
Early developmental stages of Nandus nandus (Ham.)
In order to study the early developmental stages of Nandus nandus an experiment was
conducted, where eggs and milt were obtained from the laboratory reared N nandus by
stripping after 15 hours of 150 mg/kg body weight of carp PG extract injection. Then the
eggs were fertilized in the laboratory and subsequent developmental stages were studied.
First cleavage (two cell), four cell, eight cell, sixteen cell and multi cell stages were found
30, 50, 70, 105 and 160 minutes after fertilization respectively. Morula, early gastrula,
middle gastrula, late gastrula and yolk plug stages were found 5, 8, 9, 11 and 13 hours
after fertilization respectively. Hatching occurred within 20±2 hours after fertilization,
and larvae were measured 1.60 mm in diameter. After one hour of hatching two
melanophore bands were found at the caudal region of the body of the larvae. Eyes were
first observed in l 0 hours, pectoral and pelvic fin buds appeared in 22 hours and well
developed in 38 hours old larvae. Mouth cleft and brain lobes were visible when the
larvae were 34 and 38 hours old respectively. Myomeres partially appeared in 16 hours,
which were clearly visible in 74 hours old larvae. Larvae started wandering and searching
for food after 56 hours of hatching. The yolk sac was completely absorbed when larvae became 62 hours old
Bis[benzyl N′-(3-phenylprop-2-enylidene)hydrazinecarbodithioato-κ2 N′,S]copper(II)
The CuII atom of the title complex, [Cu(C17H15N2S2)2], lies on a twofold rotation axis, and is in a distorted tetrahedral geometry with the two bidentate N2S2 Schiff bases. In the crystal structure, the molecules are interconnected into chains along the c axis by weak C—H⋯S intermolecular interactions. The crystal packing is further stabilized by C—H⋯π interactions
Predatory behaviour of a perch, Nandus nandus (Ham.)
Predatory behaviour of Nandus nandus was studied by offering Cyprinus carpio as prey.
The study was conducted with six N. namdus (8.2 ±0.2 cm and 7.60 ±0.3g) represented as
P 1, P 2, P 3, P 4, P 5 and P 6. Three size categories of prey (C. carpio) such as small (2.0 ±0.1 cm
and 0.23 ±0.01g), large (3.6 ±0.1 cm and 0.57 ±O.O.lg) and mixed group consisting of
both small and large prey were used for 14 days of trial. Predatory behavior was classified
as targeting, driving, catching, handling, resting and next attempt of catching prey. After
introduction of prey into the aquarium predators followed the movement of preys by eye
movements and tried to target smaller one first. The predator grasped the head of the
prey by its jaws by a drive and engulfed it wholly into the mouth. The average handling
time (time taken to manipulate and swallow prey from capture to ceasation of pharyngeal
movement) was 42±2 sec and 47±2 sec for small and large prey respectively. N. nandus
were ingested more small prey than large prey though the size classes were equally
available in case of mixed prey used. Although the prey consumption was higher in
number when small prey were ingested but in weight the consumption was higher when
ingested large size of prey. The study indicated that N. nandus, ingested more small prey
and grasped the headfirst
(E)-4-Octyloxybenzaldehyde thiosemicarbazone
In the title compound, C16H25N3OS, the thiosemicarbazone group adopts an E configuration with respect to the C=N bond and is almost coplanar with the benzene ring, forming a dihedral angle of 9.3 (1)°. In the crystal packing, the molecules lie along the a axis in an antiparallel arrangement and are held in place by van der Waals interactions. As a consequence, there is relatively low anisotropic thermal motion in the terminal atoms of the n-octyl chain
Magnetic coupling of porphyrin molecules through graphene
Graphene is expected to complement todays Si-based information technology. In
particular, magnetic molecules in contact with graphene constitute a
tantalizing approach towards organic spin electronics because of the reduced
conductivity mismatch at the interface. In such a system a bit is represented
by a single molecular magnetic moment, which must be stabilized against thermal
fluctuations. Here, we show in a combined experimental and theoretical study
that the moments of paramagnetic Co-octaethylporphyrin (CoOEP) molecules on
graphene can be aligned by a remarkable antiferromagnetic coupling to a Ni
substrate underneath the graphene. This coupling is mediated via the \pi\
electronic system of graphene, while no covalent bonds between the molecule and
the substrate are established.Comment: 27 pages, 12 figures, Accepted at Adv. Mate
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