Model-Based Cross-Correlation Search for Gravitational Waves from Scorpius X-1

We consider the cross-correlation search for periodic GWs and its potential application to the LMXB Sco X-1. This method coherently combines data from different detectors at the same time, as well as different times from the same or different detectors. By adjusting the maximum time offset between a pair of data segments to be coherently combined, one can tune the method to trade off sensitivity and computing costs. In particular, the detectable signal amplitude scales as the inverse fourth root of this coherence time. The improvement in amplitude sensitivity for a search with a coherence time of 1hr, compared with a directed stochastic background search with 0.25Hz wide bins is about a factor of 5.4. We show that a search of 1yr of data from Advanced LIGO and Advanced Virgo with a coherence time of 1hr would be able to detect GWs from Sco X-1 at the level predicted by torque balance over a range of signal frequencies from 30-300Hz; if the coherence time could be increased to 10hr, the range would be 20-500Hz. In addition, we consider several technical aspects of the cross-correlation method: We quantify the effects of spectral leakage and show that nearly rectangular windows still lead to the most sensitive search. We produce an explicit parameter-space metric for the cross-correlation search in general and as applied to a neutron star in a circular binary system. We consider the effects of using a signal template averaged over unknown amplitude parameters: the search is sensitive to a combination of the intrinsic signal amplitude and the inclination of the neutron star rotation axis, and the peak of the expected detection statistic is systematically offset from the true signal parameters. Finally, we describe the potential loss of SNR due to unmodelled effects such as signal phase acceleration within the Fourier transform timescale and gradual evolution of the spin frequency.Comment: 27 pages, 12 figures, 4 tables, pdflatex; synchronized to final version published in Phys Rev

Mucosal neuroimmune mechanisms in gastro-oesophageal reflux disease (GORD) pathogenesis.

Gastro-oesophageal reflux disease (GORD) is a chronic condition characterised by visceral pain in the distal oesophagus. The current first-line treatment for GORD is proton pump inhibitors (PPIs), however, PPIs are ineffective in a large cohort of patients and long-term use may have adverse effects. Emerging evidence suggests that nerve fibre number and location are likely to play interrelated roles in nociception in the oesophagus of GORD patients. Simultaneously, alterations in cells of the oesophageal mucosa, namely epithelial cells, mast cells, dendritic cells, and T lymphocytes, have been a focus of GORD research for several years. The oesophagus of GORD patients exhibits both macro- and micro-inflammation as a response to chronic acidic reflux at the epithelium. In other conditions of the GI tract, such as IBS and IBD, well-characterised bidirectional processes between immune cells and mucosal nerve fibres contribute to pathogenesis and symptom generation. Sensory alterations in these conditions such as nerve fibre outgrowth and hypersensitivity can be driven by inflammatory processes, which promote visceral pain signalling. This review will examine what is currently known of the molecular pathways linking inflammation and sensory perception leading to the development of GORD symptoms and explore potentially relevant mechanisms in other GI regions which may indicate new areas in GORD research

Bayesian Analysis of Inflation: Parameter Estimation for Single Field Models

Future astrophysical datasets promise to strengthen constraints on models of inflation, and extracting these constraints requires methods and tools commensurate with the quality of the data. In this paper we describe ModeCode, a new, publicly available code that computes the primordial scalar and tensor power spectra for single field inflationary models. ModeCode solves the inflationary mode equations numerically, avoiding the slow roll approximation. It is interfaced with CAMB and CosmoMC to compute cosmic microwave background angular power spectra and perform likelihood analysis and parameter estimation. ModeCode is easily extendable to additional models of inflation, and future updates will include Bayesian model comparison. Errors from ModeCode contribute negligibly to the error budget for analyses of data from Planck or other next generation experiments. We constrain representative single field models (phi^n with n=2/3, 1, 2, and 4, natural inflation, and "hilltop" inflation) using current data, and provide forecasts for Planck. From current data, we obtain weak but nontrivial limits on the post-inflationary physics, which is a significant source of uncertainty in the predictions of inflationary models, while we find that Planck will dramatically improve these constraints. In particular, Planck will link the inflationary dynamics with the post-inflationary growth of the horizon, and thus begin to probe the "primordial dark ages" between TeV and GUT scale energies.Comment: 16 pages, 9 figures. Updated to match published version (revised and expanded discussions of reheating uncertainties and slow roll mapping; references added; results unchanged). Code available at http://zuserver2.star.ucl.ac.uk/~hiranya/ModeCode

Rise of a Giant: Perovskite Solar Cells and Its Economic Viability

Solar energy is plentiful. Over the last decades, a significant portion of the energy market has been acquired by solar power. There are several types of solar cells in the market chosen, dependent on the application (Nayak et al., 2019). Silicon solar panels are commonly found in solar farms, and for domestic use, or in other words, it is the market leader. However, due to the specific processing of the silicon materials and lack of practical applicability due to its rigid and opaque nature, the worldwide deployment of silicon technology is still not at an appreciable level, especially in developing countries. Based on this, alternative approaches have been widely studied, out of which the most relevant technologies to mention here are Dye Sensitized Solar Cells (DSSCs) (Kokkonen et al., 2021) and Organic Photovoltaics (OPV) (Inganäs, 2018). DSSCs and OPV are based on materials that are easily processed compared to silicon and have attractive characteristics such as color variability and transparency, so they can be applied to windows and can be integrated into building aesthetic designs. With the continuous developments in these technologies, scientists were refining them to beat the efficiency and the stability achieved by its rival silicon solar cells

Spiritual Growth and Social Entrepreneurship: Understanding the integration of spirituality and social entrepreneurial process

The business world today is moving from capitalism to social entrepreneurship. Social entrepreneurs view a social mission as an explicit and central one than following the path of individual wealth creation. Seizing opportunities and utilizing resources are the key factors that influencing entrepreneurial process. Entrepreneur’s belief system is shaped or process of interpretation that makes entrepreneurs pursue solutions to social problems. Transcends from wealth creators to social warriors may be explained by focusing on their spiritual orientation (Ganzin, Islam, & Suddaby, 2020). The objective of the study is to explore the connection of spirituality development to social entrepreneurial process of social entrepreneurs. The paper offers a new theoretical conceptualization in relation to understanding how spiritual growth influences social entrepreneurs. Thus, the paper tries to build up the relationship between spiritual growth and social entrepreneurial process. As such, our paper strengthen the existing social entrepreneurship theory by introducing the spirituality dimension to the cognitive process and highlights the trigger points related to social entrepreneurial behavior that transcendence individual wealth creation. Furthermore, the linkage between the attributes of social entrepreneurial process and spiritual development phases is an eye opening to both spiritual and entrepreneurial studies. Keywords: Social entrepreneurship, Spiritual growth, Entrepreneurial proces

Comparing Infrared Dirac-Born-Infeld Brane Inflation to Observations

We compare the Infrared Dirac-Born-Infeld (IR DBI) brane inflation model to observations using a Bayesian analysis. The current data cannot distinguish it from the \LambdaCDM model, but is able to give interesting constraints on various microscopic parameters including the mass of the brane moduli potential, the fundamental string scale, the charge or warp factor of throats, and the number of the mobile branes. We quantify some distinctive testable predictions with stringy signatures, such as the large non-Gaussianity, and the large, but regional, running of the spectral index. These results illustrate how we may be able to probe aspects of string theory using cosmological observations.Comment: 54 pages, 13 figures. v2: non-Gaussianity constraint has been applied to the model; parameter constraints have tightened significantly, conclusions unchanged. References added; v3, minor revision, PRD versio

Inflation in Gauged 6D Supergravity

In this note we demonstrate that chaotic inflation can naturally be realized in the context of an anomaly free minimal gauged supergravity in D=6 which has recently been the focus of some attention. This particular model has a unique maximally symmetric ground state solution, $R^{3,1} \times S^2$ which leaves half of the six-dimensional supersymmetries unbroken. In this model, the inflaton field $\phi$ originates from the complex scalar fields in the D=6 scalar hypermultiplet. The mass and the self couplings of the scalar field are dictated by the D=6 Lagrangian. The scalar potential has an absolute munimum at $\phi = 0$ with no undetermined moduli fields. Imposing a mild bound on the radius of $S^2$ enables us to obtain chaotic inflation. The low eenrgy equations of motion are shown to be consistent for the range of scalar field values relevant for inflation.Comment: one reference adde

Compression of klockmannite, CuSe

Copper selenide (CuSe) was compressed in a diamond anvil cell at room temperature up to a pressure of 52 GPa and studied using energy dispersive x-ray diffraction and Raman spectroscopy. CuSe is nearly isostructural with copper sulfide (CuS), and a previous study indicates that copper sulfide undergoes reversible pressure-induced amorphization at 18 GPa. The intensity of the x-ray diffraction peaks for CuSe decrease slowly, however, they never completely disappear up to a pressure of 52 GPa. The third-order Birch–Murnaghan equation of state fit to the data yields K0 = 96.9±5.3 GPaK0=96.9±5.3GPa and K0′ = 4.1±0.5.K0′=4.1±0.5. Vinet’s universal equation of state yields essentially identical parameters. Raman spectroscopy demonstrates that upon compression, the S–S bond in CuS compresses differently than the Se–Se bond in CuSe, possibly accounting for the different high pressure behavior of these two very similar compounds. © 1998 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70875/2/JCPSA6-109-2-634-1.pd

Communicative Skills through Task Based Learning

Task Based Language Learning (TBLL) focuses on the use of authenticlanguage and directing students to do meaningful tasks using the target language. Basedon the constructivist theory of learning, and with the acceptance of the communicativelanguageteaching (CLT) approach in the early 1980s the term, task-based languageteaching (TBLT) came into widespread use in the field of second language acquisition(SLA) in terms of designing communicative tasks to promote learners‟ actual languageusage (Jeon and Hahn (2005).According to Gillian Porter Ladousse and Tom Noble (1991), „It can clearly beargued that being able to speak in a sustained manner, or to use “long turns”successfully in a foreign language, constitutes an authentic task and is a skill thatlanguage learners need, whether it be to sell a product, entertain dinner guests, or toexplain a problem. The oral-presentation activity provides an excellent opportunity forthe learner to develop this skill, speaking for several minutes in a structured way,delving into various aspects of a single topic.‟ (Gillian Porter Ladousse & Tom Noble –Forum xxix – 2 April 1991 p.31)The objective of this research is to improve the communicative skills andconfidence of the English as a Second Language (ESL) learner by using ESL itselfeffectively in the learning-teaching process in the ESL classroom. In particular, thestudy focuses on the use of stress-free oral presentations in groups as a majormethodological tool in achieving this objective.The sample consisted of twenty nine teacher-students of the National Instituteof Education (NIE), Maharagama, who are following the Diploma in Teaching Englishas a Second Language conducted by the NIE.They were given a series of opportunities to do different kinds of presentationson different topics depending on their syllabus. The marking criteria were known bythem before preparation. At the end of each presentation, they were evaluated and the weaknesses and the strengths were discussed in a constructive way in order to furtherimprove their presentation skills and confidence.During the observation and at the end of the process it was found out that thismethodology was very effective and successful in teaching communicative skills in theTeaching-Learning process.Observation Schedules, interviews, and evaluation sheets were used as researchinstruments to measure the strengths and weaknesses of this methodology and to arriveat the above conclusion.Key words: Task-based, Oral-presentation, Communicative-skill