InGaN Microring Light-Emitting Diodes

The fabrication and performance of an InGaN light-emitting diode (LED) array based on a microring device geometry is reported. This design has been adopted in order to increase the surface area for light extraction and to minimize losses due to internal reflections and reabsorption. Electrical characteristics of these devices are similar to those of a conventional large-area LED, while the directed light extraction proves to be superior. In fact, these devices are found to be more efficient when operated at higher currents. This may be attributed to improved heat sinking due to the large surface area to volume ratio. The potential applications of these devices are also discussed.published_or_final_versio

The dynamics of tidal tails from massive satellites

We investigate the dynamical mechanisms responsible for producing tidal tails from dwarf satellites using N-body simulations. We describe the essential dynamical mechanisms and morphological consequences of tail production in satellites with masses greater than 0.0001 of the host halo virial mass. We identify two important dynamical coconspirators: (1) the points where the attractive force of the host halo and satellite are balanced (X-points) do not occur at equal distances from the satellite centre or at the same equipotential value for massive satellites, breaking the morphological symmetry of the leading and trailing tails and (2) the escaped ejecta in the leading (trailing) tail continues to be decelerated (accelerated) by the satellite\u27s gravity leading to large offsets of the ejecta orbits from the satellite orbit. The effect of the satellite\u27s self-gravity decreases only weakly with a decreasing ratio of satellite mass to host halo mass, proportional to (Ms/Mh)1/3, demonstrating the importance of these effects over a wide range of subhalo masses. Not only will the morphology of the leading and trailing tails for massive satellites be different, but the observed radial velocities of the tails will be displaced from that of the satellite orbit; both the displacement and the maximum radial velocity is proportional to satellite mass. If the tails are assumed to follow the progenitor satellite orbits, the tails from satellites with masses greater than 0.0001 of the host halo virial mass in a spherical halo will appear to indicate a flattened halo. Therefore, a constraint on the Milky Way halo shape using tidal streams requires mass-dependent modelling. Similarly, we compute the distribution of tail orbits both in Er–r−2 space and in E–Lz space, advocated for identifying satellite stream relics. The acceleration of ejecta by a massive satellite during escape spreads the velocity distribution and obscures the signature of a well-defined ‘moving group’ in phase space. Although these findings complicate the interpretation of stellar streams and moving groups, the intrinsic mass dependence provides additional leverage on both halo and progenitor satellite properties

There is relief for constipated patients taking opioids.

A critical appraisal and clinical application of Tack J, Lappalainen J, Diva U, Tummala R, Sostek M. Efficacy and safety of naloxegol in patients with opioid-induced constipation and laxative-inadequate response. United European Gastroenterol J. 2015 Oct;3(5):471-80. doi: 10.1177/205064061560454

All the protestors fit to count: using geospatial affordances to estimate protest event size

Protest events are a hallmark of social movement tactics. Large crowds in public spaces send a clear message to those in authority. Consequently, estimating crowd size is important for clarifying how much support a particular movement has been able to garner. This is significant for policymakers and constructing public opinion alike. Efforts to accurately estimate crowd size are plagued with issues: the cost of renting aircraft (if done by air), the challenge of visibility and securing building access (if done by rooftops), and issues related to perspective and scale (if done on the ground). Airborne camera platforms like drones, balloons, and kites are geospatial affordances that open new opportunities to better estimate crowd size. In this article we adapt traditional aerial imaging techniques for deployment on an “unmanned aerial vehicle” (UAV, popularly drone) and apply the method to small (1,000) and large (30,000+) events. Ethical guidelines related to drone safety are advanced, questions related to privacy are raised, and we conclude with a discussion of what standards should guide new technologies if they are to be used for the public good

Bis[trans-dichloridobis(propane-1,3-diamine-κ2 N,N′)chromium(III)] tetra­chloridozincate determined using synchrotron radiation

In the title compound, [CrCl2(C3H10N2)2]2[ZnCl4], the CrIII atom is coordinated by four N atoms of propane-1,3-diamine (tn) and two Cl atoms in a trans arrangement, displaying a distorted octa­hedral geometry with crystallographic inversion symmetry; the Zn atom in the [ZnCl4]2− anion lies on a -4 axis. The orientations of the two six-membered chelate rings in the complex cation are in an anti chair–chair conformation with respect to each other. The Cr—N bond lengths are 2.087 (6) and 2.097 (6) Å. The Cr—Cl and Zn—Cl bond lengths are 2.3151 (16) and 2.3255 (13) Å, respectively. Weak inter­molecular hydrogen bonds involving the tn NH2 groups as donors and chloride ligands of the anion and cation as acceptors are observed

{3,14-Dimethyl-2,6,13,17-tetra­aza­tricyclo­[16.4.0.07,12]docosane-κ4 N,N′,N′′,N′′′)bis­(nitrato-κO)copper(II)

The CuII atom in the title compound, [Cu(NO3)2(C20H40N4)], is N,N′,N′′,N′′′-chelated by the macrocyclic ligand: the four N atoms form a square, above and below which are located the O atoms of the nitrate ions. The metal atom exists in a tetra­gonally distorted octa­hedron, on a special position of site symmetry. One of the amino groups is hydrogen bonded to an O atom of the nitrate ion. The other amino group is hydrogen bonded to O atom of an adjacent mol­ecule, generating a supra­molecular dimeric hydrogen-bonded dinuclear aggregate

Successive spin-flop transitions of a Neel-type antiferromagnet Li2MnO3 single crystal with a honeycomb lattice

We have carried out high magnetic field studies of single-crystalline Li2MnO3, a honeycomb lattice antiferromagnet. Its magnetic phase diagram was mapped out using magnetization measurements at applied fields up to 35 T. Our results show that it undergoes two successive meta-magnetic transitions around 9 T fields applied perpendicular to the ab plane (along the c* axis). These phase transitions are completely absent in the magnetization measured with the field applied along the ab plane. In order to understand this magnetic phase diagram, we developed a mean-field model starting from the correct Neel-type magnetic structure, consistent with our single crystal neutron diffraction data at zero field. Our model calculations succeeded in explaining the two meta-magnetic transitions that arise when Li2MnO3 enters two different spin-flop phases from the zero field Neel phase.open1187Nsciescopu

Unmanned aerial vehicle based tree canopy characteristics measurement for precision spray applications

The critical components for applying the correct amount of agrochemicals are fruit tree characteristics such as canopy height, canopy volume, and canopy coverage. An unmanned aerial vehicle (UAV)-based tree canopy characteristics measurement system was developed using image processing approaches. The UAV captured images using a high-resolution red-green-blue (RGB) camera. A digital surface model (DSM) and a digital terrain model (DTM) were generated from the captured images. A tree canopy height map was generated from the subtraction of DSM and DTM. A total of 24 apple trees were randomly targeted to measure the canopy characteristics. Region of interest (ROI) was generated across the boundary of each targeted tree. The height of all pixels within each ROI was computed separately. The pixel with maximum height was considered as the height of the respective tree. For computing canopy volume, the sum of all pixel heights from individual ROI was multiplied by the square of ground sample distance (GSD) of 5.69 mm·pixel−1. A segmentation method was employed to calculate the canopy coverage of the individual trees. The segmented canopy pixel area was divided by the total pixel area within the ROI. The results showed an average relative error of 0.2 m(6.64%) while comparing automatically measured tree height with ground measurements. For tree canopy volume, a mean absolute error of 0.25 m3 and a root mean square error of 0.33 m3 were achieved. The study estimated the possible agrochemical requirement for spraying the fruit trees, ranging from 0.1 to 0.32 l based on tree canopy volumes. The overall investigations suggest that the UAV-based tree canopy characteristics measurements could be a potential tool to calculate the pesticide requirement for precision spraying applications in tree fruit orchards

The Approaches to Increase Employees’ Loyalty: A Review on Employees’ Turnover Models

It is a widely acknowledged fact that retaining organizational employees is a critical challenge to many human resource managers, however, this relationship is said to be an important mechanisms through which socialization tactics influence commitment and turnover. From a managerial perspective, the attraction and retention of high-quality employees is more important today than ever before. A numbers of trends make it vital that firms acquire and retain human capital as it is known in human resource that turnover is the rate at which an employer gains and misplaces employees or how long employees tend to stay. Authors have pointed out that turnover is one of the most researched phenomenon in organizational behavior. Issues they need to consider may be in the areas of shrinking pool of entry-level workers, individual differences, use of temporary workers, productivity and competitiveness, retirement benefits and skills development. As it is typical for most studies on turnover, the focus is mainly on members leaving rather than entering the organization. High turnover is harmful to a company’s productivity if it involves skilled workers. Organizations are increasingly concerned about their capability to retain their key employees such as high performer and employees who make an important contribution to stimulate organization’s innovative behavior. Consequent upon this, this research seeks to review some of the past models with a view to understanding the trend and proffer recommendations to organizational policy makers in both public and private organization

Surgical Pulmonary Embolectomy Outcomes for Acute Pulmonary Embolism

Introduction: Acute pulmonary embolism (PE) is associated with significant mortality. Surgical embolectomy is a viable treatment option; however, it remains controversial due to variable outcomes. This review investigates patient outcomes following surgical embolectomy for acute PE. Methods: Electronic search was performed to identify articles reporting surgical embolectomy for treatment of PE. 32 studies were included comprising 936 patients. Demographic, perioperative, and outcome data were extracted and pooled for systematic review. Results: Mean patient age was 56.3 [95% CI 52.5; 60.1] years and 50% [46; 55] were male. 82% had right ventricular dysfunction [62; 93], 80% [67; 89] had unstable hemodynamics, and 9% [5; 16] experienced cardiac arrest. Massive PE and submassive PE were present in 83% of patients [43; 97] and 13% [2; 56], respectively. Before embolectomy, 33% of patients [14; 60] underwent systemic thrombolysis and 14% [8; 24] catheter embolectomy. Preoperatively, 47% of patients were ventilated [26; 70] and 36% had percutaneous cardiopulmonary support [11; 71]. Mean operative time and mean cardiopulmonary bypass time were 170 [101; 239] and 56 [42; 70] minutes, respectively. Intraoperative mortality was 4% [2; 8]. Mean hospital and ICU stay were 10 [6; 14] and 2 [1; 3] days, respectively. Mean postoperative systolic pulmonary artery pressure (sPAP) was significantly decreased from preoperative (sPAP 57.8 mmHg [53; 62.7]) to postoperative period (sPAP 31.3 mmHg [24.9; 37.8]), p \u3c0.01). In-hospital mortality was 16% [12; 21]. Overall survival at five years was 73% [64; 81]. Discussion: Surgical embolectomy is an acceptable treatment option with favorable outcomes