Infrared Spectroscopy of Jet-cooled “GrandPAHs” in the 3–100 μm Region

Although large polycyclic aromatic hydrocarbons (PAHs) are likely to be responsible for IR emission of gaseous and dusty regions, their neutral experimental high-resolution gas-phase IR spectra—needed to construct accurate astronomical models—have so far remained out of reach because of their nonvolatility. Applying laser desorption to overcome this problem, we report here the first IR spectra of the jet-cooled large PAHs coronene (C24H12), peropyrene (C26H14), ovalene (C32H14), and hexa(peri)benzocoronene (C42H18) in the 3–100 μm region. Apart from providing experimental spectra that can be compared directly to astronomical data, such IR spectra are crucial for assessing the accuracy of theoretically predicted spectra used to interpret interstellar IR emission. Here we use the experimental spectra to evaluate the performance of conventional calculations using the harmonic approximation, as well as calculations with an anharmonic (GVPT2) treatment. The harmonic prediction agrees well with the experiment between 100 and 1000 cm−1 (100 and 10 μm) but shows significant shortcomings in the combination band (1600–2000 cm−1, 6.25–5 μm) and CH-stretch (2950–3150 cm−1, 3.4–3.17 μm) regions. Especially the CH-stretch region is known to be dominated by the effects of anharmonicity, and we find that large PAHs are no exception. However, for the CH out-of-plane region (667–1000 cm−1, 15–10 μm) the anharmonic treatment that significantly improves the predicted spectra for small PAHs leads to large and unrealistic frequency shifts, and intensity changes for large PAHs, thereby rendering the default results unreliable. A detailed analysis of the results of the anharmonic treatment suggests a possible route for improvement, although the underlying cause for the large deviations remains a challenge for theory.

Emission characteristics of GaInN/GaN multiple quantum shell nanowire-based LEDs with different p-GaN growth conditions

Improving current injection into r- and m-planes of nanowires (NWs) is essential to realizing efficient GaInN/GaN multiple quantum shell (MQS) NW-based light-emitting diodes (LEDs). Here, we present the effects of different p-GaN shell growth conditions on the emission characteristics of MQS NW-LEDs. Firstly, a comparison between cathodoluminescence (CL) and electroluminescence (EL) spectra indicates that the emission in NW-LEDs originates from the top region of the NWs. By growing thick p-GaN shells, the variable emission peak at around 600 nm and degradation of the light output of the NW-LEDs are elaborated, which is attributable to the localization of current in the c-plane region with various In-rich clusters and deep-level defects. Utilizing a high growth rate of p-GaN shell, an increased r-plane and a reduced c-plane region promote the deposition of indium tin oxide layer over the entire NW. Therefore, the current is effectively injected into both the r- and m-planes of the NW structures. Consequently, the light output and EL peak intensity of the NW-LEDs are enhanced by factors of 4.3 and 13.8, respectively, under an injection current of 100 mA. Furthermore, scanning transmission electron microscope images demonstrate the suppression of dislocations, triangular defects, and stacking faults at the apex of the p-GaN shell with a high growth rate. Therefore, localization of current injection in nonradiative recombination centers near the c-plane was also inhibited. Our results emphasize the possibility of realizing high efficacy in NW-LEDs via optimal p-GaN shell growth conditions, which is quite promising for application in the long-wavelength region.

Object Grasping Instructions to Support Robot by Laser Beam One Drag Operations

We propose a system in which users can intuitively instruct the robot gripper’s positions and attitudes simply by tracing the object’s grasp part surface with one stroke (one drag) of the laser beam. The proposed system makes use of the “real world clicker (RWC)” we have developed earlier, a system capable of obtaining with high accuracy the three-dimensional coordinate values of laser spots on a real object by mouse-operating the time-of-flight (TOF) laser sensor installed on the pan-tilt actuator. The grasping point is specified as the centroid of the grasp part’s plane region by the laser drag trajectory. The gripper attitude is specified by selecting the left and right drag modes that correspond to the PC mouse’s left and right click buttons. By doing so, we realize a grasping instruction interface where users can take into account various physical conditions for the objects, environments, and grippers. We experimentally evaluated the proposed system by measuring the grasping instruction time of multiple test subjects for various daily use items.

Status of Start-ups in Hills and Planes of Uttarakhand: A Comparative Study

The start-up ecosystem plays a critical role in the growth & development of a society. The reason behind creation of Uttarakhand as a separate state is to have a balanced growth of people in Hills. The start-up policy is a phenomenon that ensures balanced growth by offering equal opportunities to all the segments of the society. Start-up encourages people to initiate and contribute in the economic activity at their home town and to be vocal for local. In this paper start-up ecosystem in Uttarakhand is analysed. The objective of the study is to status and comparisons of start-ups between Hills and Plane region of Uttarakhand. This study will help to design the policy to healthy growth of start-ups in rural and hilly zones of the state. Start-ups that qualify the parameters of start-up policy of Uttarakhand are taken for the study.

Glucose Oxidase Micropumps: Multi-Faceted Effects of Chemical Activity on Tracer Particles Near the Solid–Liquid Interface

We report the development of glucose oxidase pumps characterized by small lateral dimensions (≈200 μ m). We studied the effects of the activity of the enzyme pump on silica particles (“tracers”) sedimented around the enzyme pump/patch. Once the activity of the pump was turned on (i.e., the glucose substrate was added to the solution), in-plane motion of the tracers away from the enzyme patch, as well as the emergence of an in-plane region around the patch which was depleted by tracers, was observed. The lateral extent of this depletion zone increased in time at a rate dependent both on the glucose concentration and on the areal density of the enzyme in the patch. We argue that, when the tracers were very near the wall, their motion and the emergence of the depletion zone were most likely the result of diffusiophoresis and drag by osmotic flows induced at the wall, rather than that of drag by a solutal buoyancy driven convective flow. We infer that, for the glucose oxidase enzymatic pumps, bulk (solutal buoyancy), as previously reported, as well as surface (osmotic) driven flows coexist and have to be explicitly accounted for. It seems plausible to assume that this is the case in general for enzyme pumps, and these complementary effects should be considered in the design of applications, e.g., stirring or sensing inside microfluidic systems, based on such pumps.

Stress and Strain Intensity Factors of the Corner Area of the Structure Boundary

The Stress and strain state of building structures in zones with bird's mouths and cuts of the boundary is characterized by stress concentration zones emergence and requires an evaluation of strength and reliability of objects, which is the engineering practice actual task. Theoretical analysis of stress and strain state of bird's mouth areas of the region boundary is confined to the study of singular solutions of the elasticity problem with power singularities. In this case, the concept of stress or strain concentration at an irregular point of the region boundary becomes meaningless. In the present article, stress and strain state is considered in the neighborhood of the bird's mouth vertex of the boundary of a plane region, which is written with the help of the intensity factors. Two approaches are given to obtaining the expressions for displacements, stresses in the neighborhoods of an irregular point of the boundary of a plane region by means of stress intensity factors and strain intensity factors. The difference in the expressions for stresses and displacements obtained for the limiting values of stresses and strains determines the practical significance of the work during the experiments and the determination of the critical values of stresses and strains.

Rotation and spin dynamics in heavy-ion collisions

Statistical average of the axial current is evaluated on the basis of the covariantWigner function. In the zero-mass limit, the axial current is described by a smooth function only at temperatures higher than the Unruh temperature. At zero temperature, the axial current, as a function of the angular velocity and chemical potential, vanishes in a two-dimensional plane region.