A method for testing the physical and optical properties of hydrogel thin films is reported based on using long-period fiber gratings. For humidity levels from 50% to 70% RH, a wavelength decrease of 11.0 nm is observed, with a sensitivity of 0.6 nm/%RH. For humidity levels from 70% to 98% RH, a wavelength increase of 6.3 nm is seen, with a sensitivity of 0.2 nm/%RH. For humidity levels greater...

The humidity response of poly(methyl methacrylate) (PMMA)-based optical fiber Bragg gratings (POFBGs) has been studied. The characteristic wavelength of the grating is modulated by water absorption-induced swelling and refractive index change in the fiber. This work indicates that anisotropic expansion may exist in PMMA optical fiber, reducing the humidity responsivity of the grating and introd...

The variation of the optical properties of porous Vycor glass (Corning, Model 7930) under different relative-humidity conditions was studied. The adsorption of water into the glass pores was investigated with spectroscopic ellipsometry. The change of the refractive index was Deltan approximately 0.04 between 5% and 90% relative humidity. A linear relation between the ellipsometer parameter tan ...

In this study, the sensitivity and the linearity of the un-coated and TiO2-coated microfiber knot resonator (MKR) have been analyzed. The MKR is very sensitive to humidity changes since its refractive index is strongly humidity dependent. As a result, shifts occur in the resonance wavelength and there are also changes in output power. The un-coated MKR showed a sensitivity of 1.3 pm/%RH, in ter...

the aim of the study was to evaluate the effect of storage and temperature on egg physical quality in hyline chickens line. a total of 150 eggs from college of natural resources farm were sampled for the present experiment. about 70 eggs each were stored in home refrigerator (temperature, 7.46±0.23 ˚c; relative humidity, 24.80±0.05%) and room temperature (temperature, 22.98±1.12 ˚c; relative hu...

A low-cost, high-sensitivity humidity sensor based on a low-loss dielectric thin film waveguide (WG) is presented. The guided mode is produced by coupling laser light into the film by optical tunneling through a solid gap deposited on the base of a semi-cylindrical lens. The light reflected from this optical system carries information about the refractive index of the medium neighboring the WG,...

A relative humidity (RH) sensor based on single-mode-no-core-single-mode fiber (SNCS) structure is proposed and experimentally demonstrated. The agarose gel is coated on the no-core fiber (NCF) as the cladding, and multimode interference (MMI) occurs in the SNCS structure. The transmission spectrum of the sensor is modulated at different ambient relative humidities due to the tunable refractive...

Because of the differences between indoor and outdoor thermal condition, preparing some outdoor thermal indices is a way to understand and categorize the outdoor thermal sensation. The aim of these indices is not to provide thermal comfort - as it is the aim of indoor indices. Instead, they are provided to analyze outdoor thermal sensation to help architects, landscape architects and urban desi...

Reviewer #1 This study reports on measurements using single particle cavity ring-down spectroscopy to derive refractive index values as a function of both wavelength (400 – 650 nm) and relative humidity for numerous inorganic solutes of atmospheric relevance. The topic of this paper is of relevance to this journal and it is of important to the research community as information related to refrac...

The paper concerns influences of global warming on a climate change in Georgia and health of the population. In particular, one important parameter of a human thermal comfort a heat index(that represents a combination of the air temperature and relative humidity) has been investigated. The investigation was carried out on the base of real data collected in the Ministry of Preservation of the En...