Inequality and Growth in a Knowledge Economy

We develop a two sector growth model to understand the relation between inequality and growth. Agents, who are endowed with different levels of knowledge, select either into a retail or a manufacturing sector. Agents in the manufacturing sector match to carry out production. A by-product of production is creation of ideas that spill over to the retail sector and improve productivity, thereby causing growth. Ideas are generated according to an idea production function that takes the knowledge of all the agents in a firm as arguments. We go on to study how an increase in the inequality of the knowledge distribution affects the growth rate. A change in the distribution not only affects the occupational choice of agents, but also the way agents match within the manufacturing sector. We show that if the idea generation function is sufficiently convex, an increase in inequality raises the growth rate of the economy.Inequality, growth, idea generation, matching, knowledge

Learning and Knowledge Diffusion in a Global Economy

I develop a dynamic general equilibrium model to understand how multinationals affect host countries through knowledge diffusion. Workers in the model learn from their managers and knowledge diffusion takes place through worker mobility. Unlike in a model without learning, I present a novel mechanism through which an integrated equilibrium represents a Pareto improvement for the host country. I go on to explore other dynamic consequences of integration. The entry of multinationals makes the lifetime earning profiles of host country workers steeper. At the same time, if agents learn fast enough, integration creates unequal opportunities, thereby widening inequality. The ex-workers of foreign multinationals also found new firms which are, on average, larger than the largest firms under autarky.Multinationals, knowledge diffusion, learning, worker mobility, Pareto improvement, spin-offs.

Learning, Knowledge Diffusion and the Gains from Globalization

We develop a dynamic, general equilibrium model to understand how multinationals affect host countries through knowledge diffusion. Workers learn from their managers and knowledge diffusion takes place through worker mobility. We identify two forces that determine wages : the labour demand effect and the learning effect. The former tends to raise wages while the latter tends to reduce it. We show that in a model without learning, an integrated steady-state equilibrium in which incumbent host country managers operate alongside multinationals, can never be a Pareto improvement for the host country. In contrast, we present a novel mechanism through which a Pareto improvement occurs in the presence of learning dynamics. We study how integration affects the life time earnings of agents and the degree of inequality in the host country, as well as, analyze the pattern of multinational activity. In the quantitative section of the paper, we calibrate our model to fit key moments from the U.S. wage distribution and quantify gains from integration. Our estimates suggest that learning produces welfare gains that range from 2% for middle-income countries to 43% for the low-income countries.Multinationals, knowledge di¤usion, learning, welfare gains, worker mobility

Effect of Spin Orbit Coupling in non-centrosymmetric half-Heusler alloys

Spin-orbit coupled electronic structure of two representative non-polar half-Heusler alloys, namely 18 electron compound CoZrBi and 8 electron compound SiLiIn have been studied in details. An excursion through the Brillouin zone of these alloys from one high symmetry point to the other revealed rich local symmetry of the associated wave vectors resulting in non-trivial spin splitting of the bands and consequent diverse spin textures in the presence of spin-orbit coupling. Our first principles calculations supplemented with low energy $\boldsymbol{k.p}$ model Hamiltonian revealed the presence of linear Dresselhaus effect at the X point having $D_{2d}$ symmetry and Rashba effect with both linear and non-linear terms at the L point with $C_{3v}$ point group symmetry. Interestingly we have also identified non-trivial Zeeman spin splitting at the non-time reversal invariant W point and a pair of non-degenerate bands along the path $\Gamma$ to L displaying vanishing spin polarization due to the non-pseudo polar point group symmetry of the wave vectors. Further a comparative study of CoZrBi and SiLiIn suggest, in addition, to the local symmetry of the wave vectors, important role of the participating orbitals in deciding the nature and strength of spin splitting. Our calculations identify half-Heusler compounds with heavy elements displaying diverse spin textures may be ideal candidate for spin valleytronics where spin textures can be controlled by accessing different valleys around the high symmetry k-points

Social phobia and its associated factors among college‑going nursing students in the post‑COVID era: Findings from west Bengal, India

Objectives: The study was conducted to determine the prevalence of social phobia, related functional disability, and factors associated with social phobia among students in the College of Nursing, Darjeeling, West Bengal.Methods: A descriptive, cross‑sectional study was conducted among 248 nursing students. The Social Phobia Inventory, a validated self‑administered questionnaire, was used to assess social phobia; the Sheehan Disability Scale was used to assess functional disability. Analytical statistics were done using the Chi‑square test.Results: The majority (54.4%) of students had social phobia; among them, 59.3% had associated functional disability. The proportion of social phobia was higher among students aged >30 (64.7%). Social phobia was significantly higher among students who never participated in extracurricular activities (P = 0.000), who were ever bullied (P = 0.013), and having unsatisfactory academic performance (P = 0.011). The proportion of social phobia was higher among those who experienced any major traumatic incident (64.8%). The majority of students felt that involvement in peer group activities (68.5%), extracurricular activities (61.7%), and group studies (49.2%) could prevent social phobia. About 17.6% of students showed marked functional disability in social life, 11.2% in family life, and 7.4% at work.Conclusion: Social phobia is highly prevalent among nursing students. Extracurricular and peer group activities with institutional support might help students to overcome social phobia

Halide homogenization for low energy loss in 2-eV-bandgap perovskites and increased efficiency in all-perovskite triple-junction solar cells

Monolithic all-perovskite triple-junction solar cells have the potential to deliver power conversion efficiencies beyond those of state-of-art double-junction tandems and well beyond the detailed-balance limit for single junctions. Today, however, their performance is limited by large deficits in open-circuit voltage and unfulfilled potential in both short-circuit current density and fill factor in the wide-bandgap perovskite sub cell. Here we find that halide heterogeneity—present even immediately following materials synthesis—plays a key role in interfacial non-radiative recombination and collection efficiency losses under prolonged illumination for Br-rich perovskites. We find that a diammonium halide salt, propane-1,3-diammonium iodide, introduced during film fabrication, improves halide homogenization in Br-rich perovskites, leading to enhanced operating stability and a record open-circuit voltage of 1.44 V in an inverted (p–i–n) device; ~86% of the detailed-balance limit for a bandgap of 1.97 eV. The efficient wide-bandgap sub cell enables the fabrication of monolithic all-perovskite triple-junction solar cells with an open-circuit voltage of 3.33 V and a champion PCE of 25.1% (23.87% certified quasi-steady-state efficiency)

The next generation neutrino telescope: IceCube-Gen2

The IceCube Neutrino Observatory, a cubic-kilometer-scale neutrino detector at the geographic South Pole, has reached a number of milestones in the field of neutrino astrophysics: the discovery of a high-energy astrophysical neutrino flux, the temporal and directional correlation of neutrinos with a flaring blazar, and a steady emission of neutrinos from the direction of an active galaxy of a Seyfert II type and the Milky Way. The next generation neutrino telescope, IceCube-Gen2, currently under development, will consist of three essential components: an array of about 10,000 optical sensors, embedded within approximately 8 cubic kilometers of ice, for detecting neutrinos with energies of TeV and above, with a sensitivity five times greater than that of IceCube; a surface array with scintillation panels and radio antennas targeting air showers; and buried radio antennas distributed over an area of more than 400 square kilometers to significantly enhance the sensitivity of detecting neutrino sources beyond EeV. This contribution describes the design and status of IceCube-Gen2 and discusses the expected sensitivity from the simulations of the optical, surface, and radio components

Sensitivity of IceCube-Gen2 to measure flavor composition of Astrophysical neutrinos

The observation of an astrophysical neutrino flux in IceCube and its detection capability to separate between the different neutrino flavors has led IceCube to constraint the flavor content of this flux. IceCube-Gen2 is the planned extension of the current IceCube detector, which will be about 8 times larger than the current instrumented volume. In this work, we study the sensitivity of IceCube-Gen2 to the astrophysical neutrino flavor composition and investigate its tau neutrino identification capabilities. We apply the IceCube analysis on a simulated IceCube-Gen2 dataset that mimics the High Energy Starting Event (HESE) classification. Reconstructions are performed using sensors that have 3 times higher quantum efficiency and isotropic angular acceptance compared to the current IceCube optical modules. We present the projected sensitivity for 10 years of data on constraining the flavor ratio of the astrophysical neutrino flux at Earth by IceCube-Gen2

Mechanical design of the optical modules intended for IceCube-Gen2

IceCube-Gen2 is an expansion of the IceCube neutrino observatory at the South Pole that aims to increase the sensitivity to high-energy neutrinos by an order of magnitude. To this end, about 10,000 new optical modules will be installed, instrumenting a fiducial volume of about 8 km3. Two newly developed optical module types increase IceCube’s current sensitivity per module by a factor of three by integrating 16 and 18 newly developed four-inch PMTs in specially designed 12.5-inch diameter pressure vessels. Both designs use conical silicone gel pads to optically couple the PMTs to the pressure vessel to increase photon collection efficiency. The outside portion of gel pads are pre-cast onto each PMT prior to integration, while the interiors are filled and cast after the PMT assemblies are installed in the pressure vessel via a pushing mechanism. This paper presents both the mechanical design, as well as the performance of prototype modules at high pressure (70 MPa) and low temperature (−40∘C), characteristic of the environment inside the South Pole ice

Estimating the coincidence rate between the optical and radio array of IceCube-Gen2

The IceCube-Gen2 Neutrino Observatory is proposed to extend the all-flavour energy range of IceCube beyond PeV energies. It will comprise two key components: I) An enlarged 8km3 in-ice optical Cherenkov array to measure the continuation of the IceCube astrophysical neutrino flux and improve IceCube\u27s point source sensitivity above ∼100TeV; and II) A very large in-ice radio array with a surface area of about 500km2. Radio waves propagate through ice with a kilometer-long attenuation length, hence a sparse radio array allows us to instrument a huge volume of ice to achieve a sufficient sensitivity to detect neutrinos with energies above tens of PeV. The different signal topologies for neutrino-induced events measured by the optical and in-ice radio detector - the radio detector is mostly sensitive to the cascades produced in the neutrino interaction, while the optical detector can detect long-ranging muon and tau leptons with high accuracy - yield highly complementary information. When detected in coincidence, these signals will allow us to reconstruct the neutrino energy and arrival direction with high fidelity. Furthermore, if events are detected in coincidence with a sufficient rate, they resemble the unique opportunity to study systematic uncertainties and to cross-calibrate both detector components