Resolving the pulsations of subdwarf B stars: HS 0039+4302, HS 0444+0458, and an examination of the group properties of resolved pulsators

We continue our program of single-site observations of pulsating subdwarf B (sdB) stars and present the results of extensive time series photometry of HS 0039+4302 and HS 0444+0458. Both were observed at MDM Observatory during the fall of 2005. We extend the number of known frequencies for HS 0039+4302 from 4 to 14 and discover one additional frequency for HS 0444+0458, bringing the total to three. We perform standard tests to search for multiplet structure, measure amplitude variations, and examine the frequency density to constrain the mode degree $\ell$. Including the two stars in this paper, 23 pulsating sdB stars have received follow-up observations designed to decipher their pulsation spectra. It is worth an examination of what has been detected. We compare and contrast the frequency content in terms of richness and range and the amplitudes with regards to variability and diversity. We use this information to examine observational correlations with the proposed $\kappa$ pulsation mechanism as well as alternative theories.Comment: 32 pages, 18 figures, 7 tables. Accepted for publication in MNRA

Laser Control of Dissipative Two-Exciton Dynamics in Molecular Aggregates

There are two types of two-photon transitions in molecular aggregates, that is, non-local excitations of two monomers and local double excitations to some higher excited intra-monomer electronic state. As a consequence of the inter-monomer Coulomb interaction these different excitation states are coupled to each other. Higher excited intra-monomer states are rather short-lived due to efficient internal conversion of electronic into vibrational energy. Combining both processes leads to the annihilation of an electronic excitation state, which is a major loss channel for establishing high excitation densities in molecular aggregates. Applying theoretical pulse optimization techniques to a Frenkel exciton model it is shown that the dynamics of two-exciton states in linear aggregates (dimer to tetramer) can be influenced by ultrafast shaped laser pulses. In particular, it is studied to what extent the decay of the two-exciton population by inter-band transitions can be transiently suppressed. Intra-band dynamics is described by a dissipative hierarchy equation approach, which takes into account strong exciton-vibrational coupling in the non-Markovian regime.Comment: revised version, fig. 8 ne

Direct and indirect effects of risks on service-oriented supply chain: a covid-19 pandemic perspective

Purpose - A solid service-oriented foundation is required to make supply chain management a competitive advantage, especially in this Covid-19 pandemic. A well-established service-oriented supply chain becomes more adaptable to changing client expectations. This study aims at analysing the direct and indirect impact of risks on the service-oriented supply chain from a pandemic perspective. Design/methodology/approach - The Q-sort method is applied with the participation of nine top-level managers to initially review the reliability, validity, and unidimensionality of research concepts. Then a questionnaire containing these measuring variables is developed to obtain the opinions of those who are experienced in logistics and supply chain management. These empirical data are analysed based on Structural Equation Modelling (SEM) to evaluate direct and indirect effects of risks on supply chain performance. Findings - The risk is inherent in service-oriented supply chains, affecting both direct and indirect performance. The proposed risk model explains 33.6 percent of Supplier performance, 46.4 percent of Operational performance, 47.1 percent of Customer satisfaction, and 46.5 percent of Finance variation. We found that service-oriented supply chains effectively monitor demand risk. External risk has the smallest impact on supply chain performance measures, whereas demand risk has the smallest effect. That a service-oriented supply chain is focused on meeting customer demand and managing demand-related risks is reinforced by these findings. Research limitations/implications - In the literature on supply chain risk management, resilience studies and disruption management receive less attention than studies on risk assessment and risk mitigation (Katsaliaki et al., 2021). Future supply chain risk management research should differentiate between risk-as an event and/or risk-as a process since they have different periodic effects on response management and resilience. Originality/value - This is a pioneering study lookingJICA - Japan International Cooperation Agency(undefined)This work was supported by the project of “An Empirical Study on Services Value Chain based on the Experiential and Credibility Values” (Grant-in-Aid for Scientific Research (A) No.25240050), and Japanese Government by Japan International Cooperation Agency (JICA) through AUN/SEED-Net Project: 022674.242.2015/JICA-A

Labour market experiences of young UK Bangladeshi men: Identity, inclusion and exclusion in inner-city London

Detailed qualitative data are used to explore the processes perpetuatinglabour market disadvantage among young UK-Bangladeshi men living in central London. Strong forces of inclusion within the Bangladeshi community are found to interact with forces of exclusion from ‘mainstream’ society to constrain aspirations and limit opportunities. Though diverse forms of young Bangladeshi masculinity are found, a common pattern is heavy dependency on intra-ethnic networks. Negative experiences of and isolation from ‘mainstream’ society further reinforce reliance on ‘our own people’. However, acute ambivalence towards belonging to a dense Bangladeshi community exists, exemplified in the widespread denigration of the restaurant trade. Many respondents express the desire to ‘break out’ and access new experiences. The findings support current policy emphasis on ‘connecting people to work’ but highlight the more fundamental need to connect people across ethnic boundaries. The paper urges researchers to ‘unpack’ ethnicity to consider carefully what ethnic identity implies in terms of access to resources and opportunities for different individuals in different contexts in order better to understand the diversity of labour market outcomes and the persistence of disadvantage

High-rate, high-fidelity entanglement of qubits across an elementary quantum network

We demonstrate remote entanglement of trapped-ion qubits via a quantum-optical fiber link with fidelity and rate approaching those of local operations. Two ${}^{88}$Sr${}^{+}$ qubits are entangled via the polarization degree of freedom of two photons which are coupled by high-numerical-aperture lenses into single-mode optical fibers and interfere on a beamsplitter. A novel geometry allows high-efficiency photon collection while maintaining unit fidelity for ion-photon entanglement. We generate remote Bell pairs with fidelity $F=0.940(5)$ at an average rate $182\,\mathrm{s}^{-1}$ (success probability $2.18\times10^{-4}$).Comment: v2 updated to include responses to reviewers, as published in PR

Distributed generation diversity level for optimal investment planning

The task of improving the supply quality and maintaining supply continuity during emergencies has become more feasible for a distribution company (DISCO), owing to new developments in Distributed Generation (DG) technologies. Even though the technical issues regarding DG interconnection to the main grid are of great importance and are being addressed by on-going research, it must be clearly placed in the context of on the financial performance of the utility. In this paper, a general approach to quantify the technical benefits of DG employment is proposed. The power system economic impact is assessed by evaluating supply quality, supply reliability, system power losses and capital investment. Moreover, the rationale for this research also includes the possibility of DG diversity level in contribution to the economical benefits from DG integration. The approach is tested by a system which is developed from a Tasmanian distribution example. Simulation results and discussion are presented to illustrate the effectiveness and usefulness of the method

The non-compact elliptic genus: mock or modular

We analyze various perspectives on the elliptic genus of non-compact supersymmetric coset conformal field theories with central charge larger than three. We calculate the holomorphic part of the elliptic genus via a free field description of the model, and show that it agrees with algebraic expectations. The holomorphic part of the elliptic genus is directly related to an Appell-Lerch sum and behaves anomalously under modular transformation properties. We analyze the origin of the anomaly by calculating the elliptic genus through a path integral in a coset conformal field theory. The path integral codes both the holomorphic part of the elliptic genus, and a non-holomorphic remainder that finds its origin in the continuous spectrum of the non-compact model. The remainder term can be shown to agree with a function that mathematicians introduced to parameterize the difference between mock theta functions and Jacobi forms. The holomorphic part of the elliptic genus thus has a path integral completion which renders it non-holomorphic and modular.Comment: 13 page