Estimation of losses caused by sidewall roughness in thin-film lithium niobate rib and strip waveguides.

Samples of dielectric optical waveguides of rib or strip type in thin-film lithium niobate (TFLN) technology are characterized with respect to their optical loss using the Fabry-Pérot method. Attributing the losses mainly to sidewall roughness, we employ a simple perturbational procedure, based on rigorously computed mode profiles of idealized channels, to estimate the attenuation for waveguides with different cross sections. A single fit parameter suffices for an adequate modelling of the effect of the waveguide geometry on the loss levels.

Satisfaction of patients in government medical teaching institutes of Peshawar Khyber Pakhtunkhwa, Pakistan: a cross-sectional analytical study.

Objective: To evaluate patient satisfaction and its associated factors in teaching hospitals.

Methods: The cross-sectional, analytical study was conducted from September to December 2022 at three publicsector medical teaching hospitals in Peshawar, Pakistan, and comprised adult patients of either admitted to various hospital wards for at least 2 days. Data was collected using a predesigned a closed-ended questionnaire assessing patient satisfaction in different domains like, facilitation at the admission, professional knowledge and skills of the attending doctors, quality of diagnostic and nursing services, and basic amenities.

Broadband optical TaO antennas for directional emission of light.

Highly directive antennas with the ability of shaping radiation patterns in desired directions are essential for efficient on-chip optical communication with reduced cross talk. In this paper, we design and optimize three distinct broadband traveling-wave tantalum pentoxide antennas exhibiting highly directional characteristics. Our antennas contain a director and reflector deposited on a glass substrate, which are excited by a dipole emitter placed in the feed gap between the two elements.

Numerical analysis of the coherent mechanism producing negative polarization at backscattering from systems of absorbing particles.

We study a double-scattering coherent mechanism of negative polarization (NP) near opposition that is observed for powder-like surfaces. The problem is solved numerically for absorbing structures with irregular constituents, cubes, spheres, and ellipsoids larger than the wavelength of incident light. Our simulations show that double scattering between two random irregular particles shows weak NP.

Level of cardiovascular fitness and it's relationship with physical activity and body mass index in young adults of Islamabad.

Objective: To determine the level of cardiovascular fitness in young adults, and to find the relationship of maximum oxygen uptake with body mass index and physical activity.

Methods: The cross-sectional study was conducted at two private universities in Islamabad, Pakistan, from January to June 2019, and comprised subjects of both genders aged 18-25 years with normal cardiopulmonary system. Physical activity was measured usint the short form of International Physical Activity Questionnaire, while maximum oxygen uptake was measured using the Bruce protocol.