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.

Tapering-induced enhancement of light extraction efficiency of nanowire deep ultraviolet LED by theoretical simulations

A nanowire(NW) structure provides an alternative scheme for deep ultraviolet light emitting diodes(DUV-LEDs)that promises high material quality and better light extraction efficiency(LEE). In this report, we investigate the influence of the tapering angle of closely packed Al Ga N NWs, which is found to exist naturally in molecular beam epitaxy(MBE) grown NW structures, on the LEE of NW DUV-LEDs. It is observed that, by having a small tapering angle, the vertical extraction is greatly enhanced for both transverse magnetic(TM) and transverse electric(TE) polarizations. Most notably, the vertical extraction of TM emission increased from 4.8% to 24.3%,which makes the LEE reasonably large to achieve high-performance DUV-LEDs. This is because the breaking of symmetry in the vertical direction changes the propagation of the light significantly to allow more coupling into radiation modes. Finally, we introduce errors to the NW positions to show the advantages of the tapered NW structures can be projected to random closely packed NW arrays. The results obtained in this paper can provide guidelines for designing efficient NW DUV-LEDs.

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.

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.

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.