Multimode circular integrated optical microresonators: Coupled mode theory modeling

A frequency domain model of multimode circular microresonators for filter applications in integrated optics is investigated. Analytical basis modes of 2D bent waveguides or curved interfaces are combined with modes of straight channels in a spatial coupled mode theory framework. Free of fitting parameters, the model allows to predict quite efficiently the spectral response of the microresonators. It turns out to be sufficient to take only a few dominant cavity modes into account. Comparisons of these simulations with computationally more expensive rigorous numerical calculations show a satisfactory agreement

Comparison of coupled mode theory and FDTD simulations of coupling between bent and straight optical waveguides

Analysis of integrated optical cylindrical microresonators involves the coupling between a straight waveguide and a bent waveguide. Our (2D) variant of coupled mode theory is based on analytically represented mode profiles. With the bend modes expressed in Cartesian coordinates, coupled mode equations can be derived in a classical way and solved by numerical integration. Proper manipulation of the propagation matrix leads to stable results even in parameter domains of compact and/or radiative structures, which seemed unsuitable for a perturbational approach due to oscillations of the matrix elements along the propagation. Comparisons with FDTD calculations show convincing agreement

EVALUATION OF CYTOTOXIC ACTIVITY OF ETHYL ACETATE EXTRACT OF PIGMENT FROM PSEUDOMONAS AERUGINOSA

Objective: Bacterial pigments have promising applications in food, cosmetics, textile, and therapeutics. Pigments from microbial origin are stable, safer, cost effective, easy production, and extraction and thus preferred over other natural sources. Under this backdrop, isolation and characterization of pigment-producing bacteria and analysis of bioactivity of the pigment were the aim of the study. From the literature studies, the pigment production was found to be influenced by various physical factors which directed the study toward optimization of physical parameters for pigment production. Methods: Isolation of pigment-producing bacteria from water sample, cultural, and microscopic identification was done as per the standard protocol. Extraction of pigment by solvent extraction was carried out and its antibacterial and cytotoxic activity was assayed. Results: Molecular characterization of the bacteria resembled the query sequence of the isolate to 99% with Pseudomonas aeruginosa strain. Extraction of pigment by solvent extraction method resulted in crude pigment extract with antibacterial activity against Gram-negative bacteria (17 mm zone of inhibition) at 100 μg/ml concentration. Pigment showed dose-dependent inhibition on proliferation of HeLa cells at the concentration of 345.83 μg/mL. Conclusion: From the above results, it was evident that the pigment extracted from the bacterial isolate Pseudomonas aeruginosa strain JBT18N was therapeutically potential

Adaptive Wavelet Collocation Method for Simulation of Time Dependent Maxwell's Equations

This paper investigates an adaptive wavelet collocation time domain method for the numerical solution of Maxwell's equations. In this method a computational grid is dynamically adapted at each time step by using the wavelet decomposition of the field at that time instant. In the regions where the fields are highly localized, the method assigns more grid points; and in the regions where the fields are sparse, there will be less grid points. On the adapted grid, update schemes with high spatial order and explicit time stepping are formulated. The method has high compression rate, which substantially reduces the computational cost allowing efficient use of computational resources. This adaptive wavelet collocation method is especially suitable for simulation of guided-wave optical devices

Analytical approach to dielectric optical bent slab waveguides

A rigorous classical analytic frequency domain model of con?ned optical wave propagation along 2D bent slab waveguides and curved dielectric interfaces is investigated, based on a piecewise ansatz for bend mode profiles in terms of Bessel and Hankel functions. This approach provides a clear picture of the behaviour of bend modes, concerning their decay for large radial arguments or effects of varying bend radius. Fast and accurate routines are required to evaluate Bessel functions with large complex orders and large arguments. Our implementation enabled detailed studies of bent waveguide properties, including higher order bend modes and whispering gallery modes, their interference patterns, and issues related to bend mode normalization and orthogonality properties

Health and safety aspects of textile workers from Solapur (India) textile industries

Introduction: Textile sector in India plays an important role in the country's economy, providing employment to a significant population in rural and urban areas. Objectives: This paper focuses on health and safety aspects of textile workers in Solapur City (one of the key textile cluster) in the state of Maharashtra, India. Methodology: A sample of 180 workers from the identified textile industries of Solapur city were assessed for their generalphysique, muscle tone, lung condition, and eyesight using different techniques. The study aimed at developing a framework for understanding risks to textile workers resulting from lack of health and safety standards in companies. Results: Findings showed that most of the workers have been affected by respiratory problems, increase in muscle tone, eye problems and musculoskeletal problem. It has been also observed that job security or regular work impacts positively to the worker’s long term body health. However, there is an immediate need to adopt and implement measures in accordance with Indian Factories Act (OHSAS 18001/ILO-OSH 2001) which includes directions and procedures in respect of industrial installations, work environment and occupational health and safety guidelines

Simulations of vertically-coupled microdisk-resonators by 3-D vectorial coupled mode theory

Fully vectorial 3D frequency-domain simulations of vertically coupled integrated-optical microdisk-resonators are described. The 'rigorous' coupled mode theory model combines numerically computed bend modes of the cavity disk and guided modes of the straight bus waveguides

Effect of Awareness of Government Initiatives on Financial Inclusion: A Study of Domestic Workers in the City of Bengaluru

A key assumption in economics is that economic growth brings prosperity to all sections of the society in an equitable manner. Historically, economic growth is not associated with equitable distribution of wealth. Governments all over the world make policies and implement them to engineer an equitable distribution of wealth. Financial exclusion is the single most important factor which can keep poorer sections of the society away from the benefits of economic growth. Financial inclusion creates a window of opportunity for poor sections of society to take part in the economic prosperity brought in by economic growth. A financially inclusive society is where all financial products and services are available without difficulty at affordable cost. The Indian government has put policies in place to encourage financial inclusion by making financial products and services available to disadvantaged sections of the society. Jan Dhan Yojana to open bank accounts with zero balance, Aushyaman Bharath Yojana for medical insurance, Atal Pension Yojana for income after retirement, and Sukaya Samruddhi Yojana for supporting a girl child are a few of the schemes promoted by government for encouraging financial inclusion of the poorer sections of the society. Poor people residing in urban areas come to the city in search of a livelihood. They struggle to manage household expenses and some unforeseen events create a burden on their financial resources. Women in the family also participate in the workforce to support the family; many of them work as household domestic workers. The present study has been undertaken to assess the awareness regarding these initiatives among domestic workers in the city of Bengaluru. As per the report released by Bangalore Gruhakarmika Sangha (BBGS) and Manegelasa Kaarmikara Union, there are four lakh domestic workers in Bengaluru and the majority of them are women. Primary data has been collected using in-depth interviews. It is found that the awareness level with respect to government initiatives is not satisfactory

Prevalence of metabolic syndrome in women with polycystic ovarian syndrome: an observational study in a tertiary care centre in Pondicherry, India

Background: Polycystic Ovarian Syndrome (PCOS) is a multifactorial, polygenic and multisystem endocrine disorder affecting women in reproductive age. PCOS diagnosis is based on 2003 Rotterdam criteria It has been noted that hyperinsulinemia is a central factor in the pathogenesis of PCOS. Many studies show evidence of a critical link between PCOS and Metabolic Syndrome (MBS).Methods: It was a hospital - based observational study done over a period of one year with a sample size of 177.An observational study was done in patients satisfying the inclusion and exclusion criteria. After taking informed and written consent, history was obtained from the patient to know the age, socioeconomic status, present and past clinical history, menstrual and obstetric history, personal and family history and any other history as deemed necessary. Patient was clinically assessed to know the height, weight, body mass index.Results: The prevalence of MBS was 37.2%. The commonest age group was between 25- 35 years.There is no statistical association between educational qualification, economic status and the prevalence of MBS and There no significant association between the presence of acne, androgenic aloepecia and the presence of PCOS.While the presence of increased waist circumference > 88cms, USG findings consistent with PCOS, high blood pressure > 130/85 mm of Hg, elevated FBS > 110 mg/dl, low HDL <50 mg/dl were statistically significant.Conclusions: The results can be used to formulate a screening policy for metabolic syndrome, particularly in the low resource settings of developing countries