Research on Night Light Comfort of Pedestrian Space in Urban Park

The outdoor light environment significantly affects aspects of public psychological and physiological health. This study conducted experiments to quantify the effects of the light environment on visitor light comfort in urban park pedestrian space. Nine sets of lighting conditions with different average horizontal illuminance (2 lx, 6 lx, 10 lx) and colour temperatures (5600 K, 4300 K, 3000 K) were established virtual reality scenarios. Subjective light comfort was evaluated, and electroencephalogram (EEG) was measured on 18 subjects to comprehensively study the effects of different light environments on human light comfort. The results of the comprehensive evaluation showed that colour temperature had a very significant impact on subjective light comfort, with warm light being generally more favourable than cool light in enhancing human subjective light comfort. The results of the EEG analysis show that the average horizontal illuminance is an important factor in the level of physiological fatigue, and that physiological fatigue can be maintained in a superior state at an appropriate level of illuminance. Based on the results of both subjective and objective factors, a comprehensive analysis was carried out to propose a range of average horizontal illuminance (4.08 lx, 6.99 lx) and a range of colour temperature (3126 K, 4498 K) for the comprehensive light comfort zone in urban park pedestrian space.

Photogyrotactic Concentration of a Population of Swimming Microalgae Across a Porous Layer

The light environment controls the swimming of microalgae through a light-seeking and avoiding behaviour, which is known as phototaxis. In this work, we exploit phototaxis to control the migration and concentration of populations of the soil microalga Chlamydomonas reinhardtii. By imaging a suspension of these microalgae in a cuvette illuminated from above by blue light, we study how phototaxis changes the stability of the suspension and demonstrate how a thin, porous layer at the top of the cuvette prevents phototaxing microalgae from sinking, leading to the up-concentration of the microalgae in the region above the porous layer. We discuss the potential implications of our findings for microalgae in biotechnological applications and the natural environment.

PECULIARITIES OF LIGHT FUNCTIONING IN MODERN GREEK CATHOLIC CHURCHES OF UKRAINE

In each historical period, light played an important mystical role in the creation of the sacred space of the temple, and was and is an integral part of religious ritual. Light is an architectural phenomenon, the formative and communicative element of the spatial structure of the temple, the most important factor in the perception of space and layout of the temple. The subject of the analysis contained in the article is the light environment in the space of modern churches of Ukraine. An analysis of the functions of light in churches is made on the example of recently built iconic Greek Catholic temples. The peculiarities of the distribution of natural and artificial light in the space of modern churches, the similarities and differences in the organization of the light environment, as compared to the historical temples, have been revealed. The influence of the light on the architectonics of temples and the visual perception of their object environment, on the formation of the corresponding mystical mood and sacred atmosphere is defined. The values and functions of electric lighting in the structure of the light environment of the temple, the directions of development of electric lighting systems due to the expansion of their utilitarian and decorative functions are determined.