Hybridized local and charge transfer (HLCT) emitters are gaining attention as a promising class of high-efficiency emitters for organic light-emitting diodes (OLEDs) due to their efficient hot-exciton utilization and tuneable emission properties. However, a comprehensive understanding of the excited-state dynamics remains limited. To replenish this lacuna, three donor-pi-acceptor (D-pi-A) molecules having moderate twist angles (theta), with acronyms, TSBP, TBPS, and 2TBPS, comprising a triphenylamine (TPA) donor and a thiophene-modified benzophenone acceptor, are designed. These emitters exhibit high photoluminescence quantum yields (PLQYs) in solution and solid states, with TSBP achieving an exceptionally high PLQY of 94% in toluene, 40% in neat film, and 85% in polymethyl methacrylate (PMMA) film. Solvent-dependent photophysics, femtosecond transient absorption spectroscopy and theoretical investigations confirm the formation of the HLCT states in low and moderately polar environment. Utilizing a simple solution-processable method, OLED devices are fabricated with emitters exhibiting green and cyan-blue emission in non-doped and doped conditions respectively. Among them, TSBP delivers an outstanding device performance, achieving an external quantum efficiency (EQEmax) of 4.1% in a non-doped device (CIE: 0.28, 0.62) and a higher EQEmax of 5.6% (CIE: 0.20, 0.55) (CIE = Commission Internationale de l'& Eacute;clairage) in a CBP-doped device. These findings underscore the potential of HLCT-based emitters for developing efficient and cost-effective OLEDs.

In order to address the native issues associated with apt metal back contact, existence of higher density of surface states, recombination centres and losses in open circuit voltage (Voc) of CdTe absorber based solar cells, novel Cd1-xMnxTe absorber is proposed herein which could be developed via smaller Mn doping to conventional CdTe absorber. Present study unveils the numerical modeling of innovative CdMnTe absorber based solar cells having architecture of glass/FTO/WS2/Cd0.9Mn0.1Te/Ag by using SCAPS-1D simulation framework. The performance of CdMnTe/WS2 hetero-junction solar cells is theoretically explored by varying the thickness from 1 mu m to 5 mu m, bulk defect density (Nt) from 1013 cm-3 to 1017 cm-3 and acceptor doping concentration (NA) from 1014 cm-3 to 1017 cm-3 of absorber layer. Meticulous simulations reveal that modeled devices exhibited superior performance viz. Voc = 1142 mV, Jsc = 24.61 mA/cm2, FF = 88.80 % and eta = 24.98 % at optimized conditions viz. CdMnTe thickness of 5 mu m, Nt = 1 x 1013 cm-3 and NA = 1 x 1017 cm-3.

Context. Boxy/peanut and X-shaped (BP/X) bulges are prominent features in edge-on disk galaxies and they are believed to represent vertically thickened bars. Despite their relevance in bar evolution, a statistically robust census of these structures in large surveys remains lacking. Aims. We aim to provide the largest catalog of BP/X structures in edge-on galaxies to date, along with an investigation of their properties and role in shaping galaxy scaling relations. Methods. We selected a sample of 6684 edge-on galaxies from SDSS DR8 using Galaxy Zoo classifications, requiring a high edge-on probability (> 0.9) and a minimum of ten independent votes. We performed a two-dimensional (2D) image decomposition using GALFIT to obtain the structural parameters. The residual images were visually inspected to classify BP/X features into four categories: strong both-sided, both-sided, one-sided, and control (no BP/X). We also estimated the stellar mass, distance, and physical size for each galaxy. Results. Out of 6653 classified galaxies, we identified 1673 (∼25%) with both-sided BP/X features, 504 (∼8%) strong, and 1169 (∼17%) weak, as well as 1112 (∼17%) one-sided structures, making up a total of 2785 BP/X-hosting galaxies (∼42%). We find that one-sided structures, likely signatures of ongoing buckling, are more frequent than strong both-sided bulges across all stellar masses. The fraction of BP/X bulges increases with stellar surface mass density, indicating a connection with bar formation in dense discs. We also find that galaxies with strong BP/X bulges contribute to increased scatter in the stellar-mass-size and stellar-mass-surface-density relations, particularly at higher masses.

Context. Giant Low Surface Brightness galaxies (gLSBGs), such as Malin 1, host extended stellar and gaseous discs exceeding 100 kpc in radius. Their formation and evolution remain debated, with interactions with satellite galaxies and accretion streams proposed as key contributors. Malin 1 presents multiple nearby and distant satellites. Additionally, it exhibits two giant stellar streams, the largest extending 200 kpc in projection, likely related to past interactions. Aims. We investigate the orbital dynamics of Malin 1’s satellites and their possible connections with the observed stellar streams, testing their nature with different formation scenarios. Methods. We constructed gravitational potentials for Malin 1 using optical and HI rotation curve data, incorporating stellar, gaseous, and dark matter components. We explored a wide orbital parameter space to determine whether the candidate progenitors of the stellar streams could have originated from past interactions, testing both Navarro-Frenk-White (NFW) and the pseudo-isothermal (ISO) halo profiles. Results. Among several explored scenarios, some produced bound orbital solutions. The ISO halo model, with mass of M virial ≈ 2.6 × 10 12 M ⊙ , favours bound satellite orbits more than the NFW model, that has a lower mass of M virial ≈ 1.4 × 10 12 M ⊙ . These orbital models show that the giant stellar streams could be substructures of some satellites galaxies located along their leading and trailing orbital trajectories. Furthermore, our analysis indicates that the most distant Malin 1 satellite (eM1) could have reached its orbital pericentre ~1.6 Gyr ago, while the nearest companions could have interacted as early as ~100 Myr ago. At the same time, one of the closest companions would still be under a strong interaction. Another close companion displays both leading and trailing arms in a radial orbit, although it also shows a polar orbit. Furthermore, we identify some unbound orbital solutions that could link some satellites with streams. Conclusions. The observed alignment of satellites and streams indicates that past interactions likely shaped aspects of Malin 1’s morphology. Our orbital modelling constrains possible progenitors of the observed stellar streams and their orbital histories, providing new insights into the dynamical evolution of gLSBGs. Our findings are consistent with results reported very recently by other studies using Malin 1 kinematic data.

Aerial imaging and surveillance play a crucial role in forestry and agriculture processes, utilizing Unmanned Aerial Vehicles (UAVs) for high-resolution remote sensing at close range. However, navigating through dense canopies or underneath them without colliding remains a challenging problem in aerial robotics. Quantifying the reachability of aerial space is a prerequisite for deciding upon the technical feasibility of such operations. Existing literature often suggests using reactive range-based methods that rely on expensive onboard sensors like depth cameras or LiDARs. This work presents a cost-effective geometrical analysis using a monocular camera and inertial sensors to generate reachability maps. An essential contribution is proposing an efficient sector division method that significantly reduces the search space required for analysis. The generated reachability map can serve as a valuable resource for planning optimal paths and operational settings, facilitating the collision-free traversal of UAVs through complex aerial environments with various obstructions and clutter.

To understand the formation and evolution of massive cosmic structures, studying them at high redshift, in the epoch when they formed the majority of their mass, is essential. The One-hundred-deg2 DECam Imaging in Narrowbands (ODIN) survey is undertaking the widest-area narrowband program to date, to use Ly alpha-emitting galaxies (LAEs) to trace the large-scale structure (LSS) of the Universe on the scale of 10-100 cMpc at three cosmic epochs. In this work, we present results at z = 3.1 based on early ODIN data in the COSMOS field. We identify protoclusters and cosmic filaments using multiple methods and discuss their strengths and weaknesses. We then compare our observations against the IllustrisTNG suite of cosmological hydrodynamical simulations. The two are in excellent agreement, identifying a similar number and angular size of structures above a specified density threshold. We successfully recover the simulated protoclusters with log(M z=0/M circle dot) greater than or similar to 14.4 in similar to 60% of the cases. With these objects, we show that the descendant masses of our observed protoclusters can be estimated purely based on our 2D measurements, finding a median z = 0 mass of similar to 1014.5 M circle dot. The lack of information on the radial extent of each protocluster introduces a similar to 0.4 dex uncertainty in its descendant mass. Finally, we show that the recovery of the cosmic web in the vicinity of protoclusters is both efficient and accurate. The similarity of our observations and the simulations implies that our structure selection is likewise robust and efficient, demonstrating that LAEs are reliable tracers of the LSS.

Galaxies usually reside in groups and clusters where they interact gravitationally. These interactions affect the internal dynamics of the galaxies. In this thesis, we have studied the effect of flyby interactions and dark matter distributions on the evolution of bulges and disks of spiral galaxies. To understand the effect of flyby interactions on the bulges, disks, and spiral arms of Milky Way mass galaxies, we simulated disk galaxies with classical bulges and boxy/peanut pseudo-bulges, then performed their flyby interactions with 1/10 and 1/5 mass galaxies. Using photometric and kinematic bulge-disk decompositions of the major galaxy, we showed that the disks get shorter and thicker during flyby interactions. Classical bulges remain intact. However, pseudo-bulges become dynamically hotter. Tidally induced spiral arms are transient density waves. They form soon after pericenter passage and decay in two phases; the initial rapid winding and the subsequent slow winding. We showed that the spirals are the main drivers of wave-like vertical breathing motion seen in the Milky Way. Tidal interactions do not directly induce breathing motion. In another work, we showed that the oblate dark matter halos delay bar formation, so bar buckling is also delayed, but probate halos promote multiple bucklings. Due to multiple bucklings, boxy/peanut bulges in prolate halos show the maximum thickness. Using SDSS galaxies, we found that pseudo-bulges are diffuse compared to classical bulges and are commonly found in low mass galaxies. In the local volume, pseudo-bulges overcome the classical bulges even in bulge dominated galaxies, so more than $75\%$ of local volume is rotation dominated. Finally, we showed that bulgeless galaxies in Illustris TNG50 are metal-poor, have high specific angular momentum as compared to the galaxies with bulges and fall at the lower end of baryonic to dark matter mass ratio.

Unmanned Aerial Vehicles (UAVs) are becoming increasingly popular in rapid delivery of medical supplies, packages, food or other goods. In this paper, we present a solution to the delivery problem to a target vehicle which might be moving in a straight line with constant speed or may be maneuvering in a curved trajectory, using a delivery UAV. The proposed solution is based on a Circular Impact Time (CIT) Guidance law to solve the delivery problem. The problem is to match the motion of the delivery UAV with the target vehicle at the same speed and direction after approaching it from a distance. The original CIT guidance law was modified to meet this requirement by doing a guided speed adjustment of the delivery UAV. Numerical simulations are given to show the effectiveness of the proposed solution.

It is well established that bars evolve significantly after they form in galaxy discs, often changing shape both in and out of the disc plane. In some cases they may bend or buckle out of the disc plane resulting in the formation of boxy/peanut/x-shape bulges. In this paper we show that the dark matter halo shape affects bar formation and buckling. We have performed N-body simulations of bar buckling in non-spherical dark matter halos and traced bar evolution for 8 Gyr. We find that bar formation is delayed in oblate halos, resulting in delayed buckling whereas bars form earlier in prolate halos leading to earlier buckling. However, the duration of first buckling remains almost comparable. All the models show two buckling events but the most extreme prolate halo exhibits three distinct buckling features. Bars in prolate halos also show buckling signatures for the longest duration compared to spherical and oblate halos. Since ongoing buckling events are rarely observed, our study suggests that most barred galaxies may have more oblate or spherical halos rather than prolate halos. Our measurement of BPX structures also shows that prolate halos promote bar thickening and disc heating more than oblate and spherical halos.

It is now clear that the stars in the Solar neighbourhood display large-scale coherent vertical breathing motions. At the same time, Milky Way-like galaxies experience tidal interactions with satellites/companions during their evolution. While these tidal interactions can excite vertical oscillations, it is still not clear whether vertical breathing motions are excited \textit{directly} by the tidal encounters or are driven by the tidally-induced spirals. We test whether excitation of breathing motions are directly linked to tidal interactions by constructing a set of $N$-body models (with mass ratio 5:1) of unbound, single fly-by interactions with varying orbital configurations. We first reproduce the well-known result that such fly-by interactions can excite strong transient spirals (lasting for $\sim 2.9-4.2$ Gyr) in the outer disc of the host galaxy. The generation and strength of the spirals are shown to vary with the orbital parameters (the angle of interaction, and the orbital spin vector). Furthermore, we demonstrate that our fly-by models exhibit coherent breathing motions whose amplitude increases with height. The amplitudes of breathing motions show characteristic modulation along the azimuthal direction, with compressing breathing motions coinciding with the peaks of the spirals and expanding breathing motions falling in the inter-arm regions -- a signature of a spiral-driven breathing motion. These breathing motions in our models end when the strong tidally-induced spiral arms fade away. Thus, it is the tidally-induced spirals which drive the large-scale breathing motions in our fly-by models, and the dynamical role of the tidal interaction in this context is indirect.

Ankit, Kumar Tony, Lima Agnel Jana, Shuvrangshu Ghose, DebasishUnmanned aerial vehicle (UAV) applications with pick-and-place operation are plenty, and the same prevails in unmanned ground vehicle (UGV) domain. But low payload capacity for a UAV and the limited sensing capability of a UGV limit them to automate heavy-duty and large-scale construction. This complementary nature of these agents can be utilized together to cater to the needs of long-term autonomous construction. Thereby, we propose a software framework with its algorithmic details for multi-vehicle collaboration for autonomous pick-and-place operation. Three UAVs and a UGV coordinate among themselves to pick bricks of different sizes and place them at a specific location in a predetermined orientation. At the core of the decision-making process, distance-based optimization is done to generate the route plan for the agents. Generated route plan is then sent to agents via a scheduler which keeps their operations in check and, in case of failures, helps them recover autonomously. The framework provides end-to-end details on multi-vehicle pick-and-place operation, keeping collisions and failures in check. The software is developed in ROS and Gazebo environment and ready to implement on hardware. The modeling approach makes it easy to be modified and deployed to cater to any application such as warehouse stock management and package delivery, besides several other applications.

Cosmological simulations predict more classical bulges than their observational counterpart in the local Universe. Here, we quantify evolution of the bulges since z = 0.1 using photometric parameters of nearly 39,000 unbarred disc galaxies from SDSS DR7 which are well represented by two components. We adopted a combination of the Sérsic index and Kormendy relation to separate classical bulges and disc-like pseudo-bulges. We found that the fraction of pseudo-bulges (classical bulges) smoothly increases (decreases) as the Universe gets older. In the history of the Universe, there comes a point (z ≈ 0.016) when classical bulges and pseudo-bulges become equal in number. The fraction of pseudo-bulges rises with increasing bulge to disc half-light radius ratio until Re/Rhlr ≈ 0.6 suggesting concentrated disc is the most favourable place for pseudo-bulge formation. The mean ellipticity of pseudo-bulges is always greater than that of classical bulges and it decreases with decreasing redshift indicating that the bulges tend to be more axisymmetric with evolution. Also, the massive bulges are progressing towards axisymmetry at steeper rate than the low-mass bulges. There is no tight correlation of bulge Sérsic index evolution with other photometric properties of the galaxy. Using the sample of multi-component fitting of S4G data and N −body galaxy models, we have verified that our results are consistent or even more pronounced with multi-component fitting and high-resolution photometry.

ABSTRACT Galaxy flybys are as common as mergers in low-redshift Universe and are important for galaxy evolution as they involve the exchange of significant amounts of mass and energy. In this study, we investigate the effect of minor flybys on the bulges, discs, and spiral arms of Milky Way mass galaxies for two types of bulges – classical bulges and boxy/peanut pseudo-bulges. Our N-body simulations comprise of two disc galaxies of mass ratios 10:1 and 5:1, where the discs of the galaxies lie in their orbital plane and the pericentre distance is varied. We performed photometric and kinematic bulge–disc decomposition at regular time-steps and traced the evolution of the disc size, spiral structure, bulge sersic index, bulge mass, and bulge angular momentum. Our results show that the main effect on the discs is disc thickening, which is seen as the increase in the ratio of disc scale height to scale radius. The strength of the spiral structure A2/A0 shows small oscillations about the mean time-varying amplitude in the pseudo-bulge host galaxies. The flyby has no significant effect on non-rotating classical bulge, which shows that these bulges are extremely stable in galaxy interactions. However, the pseudo-bulges become dynamically hotter in flybys indicating that flybys may play an important role in accelerating the rate of secular evolution in disc galaxies. This effect on pseudo-bulges is a result of their rotating nature as part of the bar. Also, flybys do not affect the time and strength of bar buckling.

The use of internet-connected devices, especially small multi-rotor Unmanned Aerial Vehicles (UAVs), in scientific data gathering and applications is quite widespread. But due to limited intervention capability, the UAVs alone fail to automate agricultural tasks completely. Thereby, we propose a centralized framework capable of handling a heterogeneous mixture of UAVs and UGVs to cater to the needs of automating agriculture efficiently. The framework's core is a novel heuristic decision module that creates new tasks by visually analyzing the farm and solves a vehicle routing problem to allocate it to agents optimally. It is also equipped with supporting modules to monitor their operation and, in case of failures, help them recover autonomously based on the task and agent assessment. The framework is used in three significant agricultural applications, namely yield prediction and drought stress detection in a simulated environment using ROS and Gazebo, and 3D mapping of a real farm. These applications demonstrate the use of the multi-agent collaborative framework in identifying agricultural tasks on a farm and executing them.

This paper details the algorithms involved and task planner for vehicle collaboration in building a structure. This is the problem defined in challenge 2 of Mohammed Bin Zayed International Robotic Challenge 2020 (MBZIRC). The work addresses various aspects of the challenge for Unmanned Aerial Vehicles (UAVs) and Unmanned Ground Vehicle (UGV). The challenge involves repeated pick and place operations using UAVs and UGV to build two structures of different shape and sizes. The algorithms are implemented using the Robot Operating System (ROS) framework and visualised in Gazebo. The whole developed architecture could readily be implemented in suitable hardware.

Stuart J. Mumford∗1, 2, 3, Nabil Freij4, Steven Christe5, Jack Ireland5, Florian Mayer6, V. Keith Hughitt7, Albert Y. Shih5, Daniel F. Ryan8, 5, Simon Liedtke6, David Pérez-Suárez9, Pritish Chakraborty10, Vishnunarayan K I.6, Andrew Inglis11, Punyaslok Pattnaik12, Brigitta Sipőcz13, Rishabh Sharma6, Andrew Leonard3, David Stansby14, Russell Hewett15, Alex Hamilton6, Laura Hayes5, Asish Panda6, Matt Earnshaw6, Nitin Choudhary16, Ankit Kumar6, Prateek Chanda17, Md Akramul Haque18, Michael S Kirk11, Michael Mueller6, Sudarshan Konge6, Rajul Srivastava6, Yash Jain19, Samuel Bennett6, Ankit Baruah6, Will Barnes20, Michael Charlton6, Shane Maloney21, Nicky Chorley22, Himanshu6, Sanskar Modi6, James Paul Mason6, Naman96396, Jose Ivan Campos Rozo23, Larry Manley6, Agneet Chatterjee24, John Evans6, Michael Malocha6, Monica G. Bobra25, Sourav Ghosh24, Airmansmith976, Dominik Stańczak26, Ruben De Visscher6, Shresth Verma27, Ankit Agrawal6, Dumindu Buddhika6, Swapnil Sharma6, Jongyeob Park28, Matt Bates6, Dhruv Goel6, Garrison Taylor29, Goran Cetusic6, Jacob6, Mateo Inchaurrandieta6, Sally Dacie30, Sanjeev Dubey6, Deepankar Sharma6, Erik M. Bray6, Jai Ram Rideout31, Serge Zahniy5, Tomas Meszaros6, Abhigyan Bose6, André Chicrala32, Ankit6, Chloé Guennou6, Daniel D’Avella6, Daniel Williams33, Jordan Ballew6, Nick Murphy34, Priyank Lodha6, Thomas Robitaille6, Yash Krishan6, Andrew Hill6, Arthur Eigenbrot35, Benjamin Mampaey36, Bernhard M. Wiedemann6, Carlos Molina6, Duygu Keşkek6, Ishtyaq Habib6, Joseph Letts6, Juanjo Bazán37, Quinn Arbolante38, Reid Gomillion6, Yash Kothari6, Yash Sharma6, Abigail L. Stevens39, 40, Adrian Price-Whelan41, Ambar Mehrotra6, Arseniy Kustov6, Brandon Stone6, Trung Kien Dang42, Emmanuel Arias6, Fionnlagh Mackenzie Dover1, Freek Verstringe36, Gulshan Kumar43, Harsh Mathur44, Igor Babuschkin6, Jaylen Wimbish6, Juan Camilo Buitrago-Casas6, Kalpesh Krishna45, Kaustubh Hiware46, Manas Mangaonkar6, Matthew Mendero6, Mickaël Schoentgen6, Norbert G Gyenge47, Ole Streicher48, Rajasekhar Reddy Mekala6, Rishabh Mishra6, Shashank Srikanth43, Sarthak Jain6, Tannmay Yadav49, Tessa D. Wilkinson6, Tiago M. D. Pereira50, 51, Yudhik Agrawal12, jamescalixto6, yasintoda6, and Sophie A. Murray52

AbstractWe investigate the minor interactions of two disk galaxies with mass ratio of 10:1 in fly-by encounters that do not lead to the merging of the galaxies. In our N-body simulations, we vary only the pericenter distances to see the effect of the fly-by on the bulge of the major galaxy over the course of the trajectory. At different time steps of the evolution, we did two-dimensional fittings of disk, bulge and bar to trace the variation in the sersic index of the bulge. Our results suggest that galaxy bulges can become boxy/disky through flyby interactions of galaxies.

The permeability of atomic hydrogen in monolayer hexagonal Boron Nitride(h-BN) and graphene has been studied using first-principles density functional theory based simulations. For the specific cases of physisorption and chemisoroption, barrier heights are calculated using the nudged elastic band approach. We find that the barrier potential for physisorption through the ring is lower for graphene than h-BN. In the case of chemisorption, where the H atom passes through by making bonds with the atoms in the ring, the barrier potential for the graphene was found to be higher than that of h-BN. We conclude that the penetration of H atom with notable kinetic energy(<3eV) through physiosorption is more probable for graphene as compared to h-BN. Whereas through chemisorption, lower kinetic energy(>3eV) H-atoms have a higher chance to penetrate through h-BN than graphene.

We study the permeability of atomic hydrogen in monolayer hexagonal boron nitride (h-BN) and graphene using first-principles density functional theory-based simulations. For the specific cases of physisorption and chemisorption, barrier heights are calculated using the nudged elastic band approach. We find that the barrier potential for physisorption through the ring is lower for graphene than for h-BN. In the case of chemisorption, we have studied three specific cases where the H atom passes through by making bonds with the atoms at different sites in the ring. The chemisorption barrier height for graphene is found to be, in general, higher than that of h-BN. We conclude that the dominant mechanism of tunnelling through the graphene sheet and h-BN sheets would be physisorption and chemisorption, respectively.