The influence of Mozart's sonata K.448 on visual attention: An ERPs study

In the present study, the effects of Mozart's sonata K.448 on voluntary and involuntary attention were investigated by recording and analyzing behavioral and event-related potentials (ERPs) data in a three-stimulus visual oddball task. P3a (related to inv

Contribución al estudio biológico de Loligo brasiliensis Bl

A total of 592 individuals of Loligo brasiliensis from the Mar del Plata coastal fishing area (Buenos Aires prov., Argentina) have been studied during the 1961-1964 period. From a morphological point of view the population appears to be uniform and homogeneus. A brief description of this species is given in this paper since references in the literature are scarce from the time at which Blainville (1923) first described it. The only further references are found in D'Orbigny (1835), and Ferrusac (1839), and in Hoyle (1886), and Tyron Pilsbry (1879). In this paper the species was mentioned only as a bibliographical reference on morphological or biological conditions has been found in the literature. The distribution of this species ranges from Cuba, Brazil, Uruguay to the Argentine coast, probably down to the Gulf of San Jorge. The samples had been studied with respect to various body measurements by classifing the individuals in total length classes, since body length was considered the most significant measurement. The condition factor K has been calculated for different sexes and ages, for the various length classes. The results lead to the conclusion that the smaller the length the higher is the value obtained for K and viceversa. This is due to the fact that the length of the tentacle increases considerably with increasing size. Since the tentacle are quite light the factor K diminishes accordingly. The condition factor increases considerably from December to April with an average of 0.42, decrease and becomes stable from March to October, with an average of 0.30. This is a consequence of the ripening of the sex glands. The sex-ratios are as following: year 1961, 42 % female, 42 % male; year 1962, 51 % female, 45 % male; year 1963, 46 % female, 53 % male; year 1964, 26 % female, 42 % male, 32 % indif. The great percentage of 72 undifferentiated young individuals in the 1964 (March) sampling increases the ratio of undifferentiation. A short morphological description of both ovules and spermatozoos is given. An examination of the sex glands leads to the following conclusions: a) male and female sex gland in a preparatory stage during the whole year; b) the highest percentage of ripe glands is found through, November-March; e) the spawning appears to precede rather slowly, but this certain since the spawning environment does not coincide with the natural habitat of the species. Few spawning individuals were found; d) sexual differentiation begins at body lenght from 30 to 40 mm; i.e. a total length of approximately 145 mm. At a body length of 70 mm. the hectocotilication (sexual character) begins to appear. In June 1962, a sample gathered at Rawson (Chubut) was analyzed. The conclusion was reached that the sex glands in this population are in an earlier stage of development in comparison with those from the Mar del Plata area. Also the average for the factor K which were found to be 0.17 for females and 0.19 for male, are rather low for that date. These physiological facts are possibly related to morphological differences which will be pointed out in a forthcoming publication. Some very typical associations with Artemesia longinaris and Percophis brasiliensis were found. Cannibalism has been observed.

Field emission properties of single-walled carbon nanotubes with a variety of emitter morphologies

Field emission properties of single-walled carbon nanotubes (SWCNTs), which were prepared through alcohol catalytic chemical vapor deposition for 10-60s, were characterized in a diode configuration. Protrusive bundles at the top surface of samples act selectively as emission sites. The number of emission sites was controlled by emitter morphologies combined with texturing of Si substrates. SWCNTs grown on a textured Si substrate exhibited a turn-on field as low as 2.4 V/μm at a field emission current density of 1 μA/cm 2. Uniform spatial luminescence (0.5 cm2) from the rear surface of the anode was revealed for SWCNTs prepared on the textured Si substrate. Deterioration of field emission properties through repetitive measurements was reduced for the textured samples in comparison with vertically aligned SWCNTs and a random network of SWCNTs prepared on flat Si substrates. Emitter morphology resulting in improved field emission properties is a crucial factor for the fabrication of SWCNT-electron sources. Morphologically controlled SWCNTs with promising emitter performance are expected to be practical electron sources. © 2008 The Japan Society of Applied Physics.

Spontaneous induction of the uniform lying helix alignment in bimesogenic liquid crystals for the flexoelectro-optic effect

Using in-plane electric fields, the electrical induction of the uniform lying helix (ULH) alignment in chiral nematic liquid crystals is reported. This process permits spontaneous induction of the ULH alignment to give an in-plane optic axis, without the need for complex processing. Flexoelectro-optic switching is subsequently obtained by holding the in-plane electrodes at a common voltage and addressing via a third, plane-parallel electrode on a second, or upper, substrate to give a field across the device in the viewing direction. For this device, in optimized bimesogenic materials, we demonstrate full intensity modulation and sub-millisecond response times at typical device temperatures. © 2012 American Institute of Physics.

Low partial pressure chemical vapor deposition of graphene on copper

A systematic study of the Cu-catalyzed chemical vapor deposition of graphene under extremely low partial pressure is carried out. A carbon precursor supply of just P CH4∼ 0.009 mbar during the deposition favors the formation of large-area uniform monolayer graphene verified by Raman spectra. A diluted HNO 3 solution is used to remove Cu before transferring graphene onto SiO 2/Si substrates or carbon grids. The graphene can be made suspended over a ∼12 μm distance, indicating its good mechanical properties. Electron transport measurements show the graphene sheet resistance of ∼0.6 kΩ/□ at zero gate voltage. The mobilities of electrons and holes are ∼1800 cm 2/Vs at 4.2 K and ∼1200 cm 2/Vs at room temperature. © 2011 IEEE.

Controllable chemical vapor deposition of large area uniform nanocrystalline graphene directly on silicon dioxide

Metal-catalyst-free chemical vapor deposition (CVD) of large area uniform nanocrystalline graphene on oxidized silicon substrates is demonstrated. The material grows slowly, allowing for thickness control down to monolayer graphene. The as-grown thin films are continuous with no observable pinholes, and are smooth and uniform across whole wafers, as inspected by optical-, scanning electron-, and atomic force microscopy. The sp 2 hybridized carbon structure is confirmed by Raman spectroscopy. Room temperature electrical measurements show ohmic behavior (sheet resistance similar to exfoliated graphene) and up to 13 of electric-field effect. The Hall mobility is ∼40 cm 2/Vs, which is an order of magnitude higher than previously reported values for nanocrystalline graphene. Transmission electron microscopy, Raman spectroscopy, and transport measurements indicate a graphene crystalline domain size ∼10 nm. The absence of transfer to another substrate allows avoidance of wrinkles, holes, and etching residues which are usually detrimental to device performance. This work provides a broader perspective of graphene CVD and shows a viable route toward applications involving transparent electrodes. © 2012 American Institute of Physics.