Improvement of light uniformity by lighting arrangement for standardized crop production

In a commercialized, fully artificial plant factory, artificial luminaire is arranged in a unified way using a general illumination theory, an actual measurement, or an empirical methodology. However, with these methods, lightings are implemented without considering specific optical characteristics of lighting or material characteristics of each component that constructs a cultivation system, resulting in an amount of light that becomes irregular. The amount of lighting is closely related with the growth and quality of crops, and the deviation between points where cultivated crops are located causes quality difference in the produced crops, thus impairing the economic feasibility of a plant factory. In this regard, a simulation to figure out an optimum lighting layout was performed. Arrangements based on the spectrum distribution of light source and reflector materials were implemented to ascertain the distance between lighting and height of lighting and gather information in the pre-treatment process to improve the uniformity of light in the plant cultivation system. Improvement of around 15% in light uniformity is achieved compared with the existing system after the simulation is carried out. This result would reduce the deviation in crop growth to make uniform quality crop production possible.

Opening design using bayesian optimization

Background Opening design is a major consideration in architectural buildings during early structural layout specification.Decisions regarding the geometric characteristics of windows,skylights,hatches,etc.,significantly affect the overall energy efficiency,airflow,and appearance of a building both internally and externally.Methods In this work,we employ a goal-based,illumination-driven approach to opening design using a Bayesian optimization approach based on Gaussian processes.A method that enables designers to conveniently set lighting intentions in conjunction with the qualitative and quantitative characteristics of the desired openings is proposed.Results The parameters are optimized within a cost-minimization framework to calculate geometrically feasible,architecturally admissible,and aesthetically pleasing openings of any desired shape while taking into account the designer′s lighting constraints.

Instantaneous lighting quality within higher educational classrooms in Singapore

This paper presents a field study that explores lighting qualities within higher educational classrooms in Singapore.Eight classrooms of three typesdcomputer labs,collaborative learning spaces and lecture hallsdare studied.Lighting simulation models are calibrated and validated by measurements taken onsite and utilized to generate both instantaneous and annual physical lighting data.A questionnaire survey is distributed to 333 participants to gather subjective responses to current lighting perception.The results show that electrically lit lecture halls present more uniform distributions of lighting environments,while daylit computer labs and daylit collaborative learning spaces present relatively lower daylighting conditions.For daylit computer labs,horizontal illuminance is an effective predictor in terms of controlling lighting levels;For electrically lit lecture halls,the mean luminance of the horizontal 40_band is an effective predictor in terms of subjective lighting comfort.

Numerical Investigation of a Refractive Index SPR D-Type Optical Fiber Sensor Using COMSOL Multiphysics

Recently, many programs have been developed for simulation or analysis of the different parameters of light propagation in optical fibers, either for sensing or for communication purposes. In this paper, it is shown the COMSOL Multiphysics as a fairly robust and simple program, due to the existence of a graphical environment, to perform simulations with good accuracy. Results are compared with other simulation analysis, focusing on the surface plasmon resonance （SPR） phenomena for refractive index sensing in a D-type optical fiber, where the characteristics of the material layers, in terms of the type and thickness, and the residual fiber cladding thickness are optimized.

Physiological response of locusts to eye stimulation by spectral illumination for phototactic pest control

To provide theoretical support for study of locust phototactic vision nature,the locust phototactic physiology and visual spectrum effects were investigated by stimulating the visual system using light from an AvaSpec fiber-optic spectrometer and Flir thermal imaging system.When light stimulated the locust visual system,the biological photoelectric transformation effect of the visual system caused by photon energy,presented with the higher physiological temperature on the forehead,as tested by the Flir thermal system.After stimulation with light,the different absorption degrees of the vision system on the spectral photons,as tested by the AvaSpec spectrometer,showed that the phototactic response to light had the simultaneous requirements of lighting intensity and time.The absorbing differences of spectral photons by the vision system demonstrated the absorption selectivity under light stimulation,as exhibited by the sensitive absorption of spectral energy at 430 nm,545 nm and 615 nm.Moreover,the higher forehead temperature increment indicated and induced the stronger physiology activity which was the reason that causing the good phototactic response degree of locusts with 30 min light stimulation,and the adaption time was about 60 min.Therefore,only when the visual reaction effect was stimulated to absorb sensitive spectral energy and generate the physiological exciting response could cause the phototactic behavior.

Photocatalytic activity of TiO2 containing anatase nanoparticles and rutile nanoflower structure consisting of nanorods

A series of TiO2 with different crystal phases and morphologies was synthesized via a facile hydrothermal process using titanium nbutoxide and concentrated hydrochloric acid as raw materials. The photocatalytic activity of the samples was evaluated by degradation of Methyl Orange in aqueous solution under UV-Visible light irradiation. On the basis of detailed analysis of the characterizing results of high-resolution transmission electron microscopy, X-ray powder diffraction measurements, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller measurement, it was concluded that the photo-activity of the catalyst is related directly to the 3D morphology and the crystal phase composition. An excellent catalyst should have both a futile 3D flower-like structure and anatase granulous particles. The 3D flower-like structure could enhance light harvesting, as well as the transfer of reactant molecules from bulk solution to the reactive sites on TiO2. In addition, the optimum anatase/rutile phase ratio was found to be 80：20, which is beneficial to the effective separation of the photogenerated electron-hole pairs.

Photocatalytic degradation of the diazo dye naphthol blue black in water using MWCNT/Gd,N,S-TiO_2 nanocomposites under simulated solar light

A simple sol-gel method was employed to prepare gadolinium, nitrogen and sulphur tridoped titania decorated on oxidised multiwalled carbon nanotubes（MWCNT/Gd,N,S-Ti O2）, using titanium（IV） butoxide and thiourea as titanium and nitrogen and sulphur source, respectively. Samples of varying gadolinium loadings（0.2%, 0.6%, 1.0% and3.0% Gd3＋） relative to titania were prepared to investigate the effect of gadolinium loading and the amounts of carbon nanotubes, nitrogen and sulphur were kept constant for all the samples. Furthermore, the prepared nanocomposites were evaluated for the degradation of naphthol blue black（NBB） in water under simulated solar light irradiation. Higher degradation efficiency（95.7%） was recorded for the MWCNT/Gd,N,S-Ti O2（0.6% Gd）nanocomposites. The higher photocatalytic activity is attributed to the combined effect of improved visible light absorption and charge separation due to the synergistic effect of Gd,MWCNTs, N, S and Ti O2. Total organic carbon（TOC） analysis revealed a higher degree of complete mineralisation of naphthol blue black（78.0% TOC removal） which minimises the possible formation of toxic degradation by-products such as the aromatic amines. The MWCNT/Gd,N,S-Ti O2（0.6% Gd） was fairly stable and could be re-used for five times,reaching a maximum degradation efficiency of 91.8% after the five cycles.