scholarly journals Physiologically based control of the process of gentle light awakening

2021 ◽  
Vol 2127 (1) ◽  
pp. 012064
Author(s):  
A B Fedortsov ◽  
M O Silivanov
Keyword(s):  
Computer Control ◽  
Visible Spectrum ◽  
Well Being ◽  
Physical Factor ◽  
Short Wave ◽  
Physical Factors ◽  
Light Emitting ◽  
Rods And Cones ◽  
The Awakening ◽  
Human Eyes

Abstract The well-being of a person and the efficiency of his production activities are largely determined by the correspondence of the biorhythms of a person to his working schedule. As it was established at the molecular and genetic level, the main physical factor that allows us to control human biorhythms is light (Nobel Prize 2017). Modern studies of ophthalmologists have found a third type of photoreceptors in human eyes, in addition to rods and cones. These receptors are not intended for receiving images, but primarily for correcting biorhythms, including controlling the process of awakening. The third type of receptors are sensitive mainly in the short-wave, blue region of the visible spectrum. In recent years light-emitting diodes have appeared. However, these devices do not take into account the current requirements for the spectrum of the awakening radiation, and even more so do not allow it to be adjusted during the awakening process according to the necessary program. We offer a technology for gentle awakening of the employee, based on modern concepts of ophthalmology and biorhythmology. The technology uses computer control of the physical factors of awakening-light and sound.

scholarly journals Identifying the cause of thermal droop in GaInN-based LEDs by carrier- and thermo-dynamics analysis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Dong-Pyo Han ◽  
Gyeong Won Lee ◽  
Sangjin Min ◽  
Dong-Soo Shin ◽  
Jong-In Shim ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Complex Dynamics ◽  
Physical Factor ◽  
Physical Factors ◽  
Temperature Dependent ◽  
Light Emitting ◽  
Carrier Lifetimes ◽  
Driving Current ◽  
Wide Range ◽  
Thermal Droop

Abstract This study aims to elucidate the carrier dynamics behind thermal droop in GaInN-based blue light-emitting diodes (LEDs) by separating multiple physical factors. To this end, first, we study the differential carrier lifetimes (DCLs) by measuring the impedance of a sample LED under given driving-current conditions over a very wide operating temperature range of 300 K–500 K. The measured DCLs are decoupled into radiative carrier lifetime (τR) and nonradiative carrier lifetime (τNR), via utilization of the experimental DCL data, and then very carefully investigated as a function of driving current over a wide range of operating temperatures. Next, to understand the measurement results of temperature-dependent τR and τNR characteristics, thermodynamic analysis is conducted, which enables to look deeply into the temperature-dependent behavior of the carriers. On the basis of the results, we reveal that thermal droop is originated by the complex dynamics of multiple closely interrelated physical factors instead of a single physical factor. In particular, we discuss the inherent cause of accelerated thermal droop with elevated temperature.

scholarly journals The School as an Arena for Co-Creating Participation, Equity, and Well-Being—A Photovoice Study from Norway

2021 ◽  
Vol 18 (16) ◽  
pp. 8252
Author(s):  
Camilla Ihlebæk ◽  
Camilla Castellan ◽  
Jenny Flobak ◽  
Jo Ese
Keyword(s):  
Human Resources ◽  
Essential Role ◽  
Well Being ◽  
Physical Factors ◽  
Ethnic Communities ◽  
Focus Group Discussions ◽  
School Employees ◽  
Group Discussions ◽  
Community Activities ◽  
Participatory Method

Schools may play an essential role as an arena for co-creating community activities that enhance well-being, equity, and citizenship. Still, there is limited knowledge about physical and non-physical factors that contribute to well-being within such approaches. The aim of this study was to identify important factors for well-being as perceived by pupils, school employees, and parents in a community school in Norway. The participatory method photovoice was used, and seven pupils, six employees, and four parents participated by taking photos used as the basis for six focus group discussions. Transcripts of the discussions were analyzed using Systematic Text Condensation. The analysis showed that the participants experienced that the school’s built and natural environment, the activities happening there, and the human resources and organization at the school facilitated perceptions of safety, inclusion, and cohesion, which in turn contributed to well-being. Furthermore, the results showed that co-creating schools as a community arena could be an innovative way of ensuring participation, equity, and well-being in the community. Such an approach might be especially important in deprived areas or in multi-ethnic communities. An important prerequisite to succeed is the openness of the school’s staff to engage in co-creation with other stakeholders in the community.

Growth and Characterization of AllnGaN/InGaN Heterostructures

1996 ◽  
Vol 423 ◽  
Author(s):  
J. C. Roberts ◽  
F. G. Mcintosh ◽  
M. Aumer ◽  
V. Joshkin ◽  
K. S. Boutros ◽  
...  
Keyword(s):  
High Performance ◽  
Visible Spectrum ◽  
Growth Conditions ◽  
Light Emitting ◽  
Mocvd Growth ◽  
Near Ultraviolet ◽  
Active Layers ◽  
Double Heterostructures ◽  
Lattice Matched

AbstractThe emission wavelength of the InxGa1−xN ternary system can span from the near ultraviolet through red regions of the visible spectrum. High quality double heterostructures with these InxGa1−xN active layers are essential in the development of efficient optoelectronic devices such as high performance light emitting diodes and laser diodes. We will report on the MOCVD growth and characterization of thick and thin InGaN films. Thick InxGa1−xN films with values of x up to 0.40 have been deposited and their photoluminescence (PL) spectra measured. AlGaN/InGaN/AlGaN double heterostructures (DHs) have been grown that exhibit PL emission in the violet, blue, green and yellow spectral regions, depending on the growth conditions of the thin InGaN active layer. Preliminary results of an AllnGaN/InGaN/AllnGaN DH, with the potential of realizing a near-lattice matched structure, will also be presented.

scholarly journals Restructuring the Out Door Spaces of Selected Public Buildings to Enhance User Satisfaction in Abuja

2020 ◽  
Vol 4 (1) ◽  
Keyword(s):  
User Satisfaction ◽  
Quantitative Research ◽  
Open Space ◽  
Well Being ◽  
Outdoor Environment ◽  
Physical Factors ◽  
Research Approach ◽  
Public Buildings ◽  
Open Spaces ◽  
Outdoor Spaces

The use of outdoor (open) spaces in public buildings is vast and has significant roles ranging from individual (users) perception of the development of urban centers and cities to the satisfaction of the various functions they perform. However, little research is available on the use of the outdoor spaces in these Public buildings environment and the activities that take place thereof. This study investigates the factors that take users of public buildings to the outdoor environment and the physical factors that constitute their uses within the spaces. Using both qualitative and quantitative research approach, the paper examined the importance of restructuring the outdoor spaces for quality of the surrounding of the built environment. The study adopts a purposive sampling where participants were selected based on the outdoor use only. A total of seventy (75) questionnaires were administered to the various users of public buildings within specific open spaces. Only seventy (70) representing (93.33%) of the total population were returned and subjected to data analysis using the relevant descriptive and inferential statistical techniques, Mean Weighted Score (MWS) and Relatively Important Index (R.I.I) were used to rank features obtained. The study concludes that proper restructuring of landscape elements is necessary within public buildings, in order to provide human comfort, well-being and improved productivity. It was recommended that revitalizing the environmental features of these public building necessitates the insufficiency of outdoor features in government own buildings. Therefore, the user’s satisfaction of this outdoor (open) space in public buildings should be key consideration and emphasized on right from planning and design stages to it implementation.

scholarly journals Prospects of using extremely low doses of physical factors impact in food biotechnology

2018 ◽  
Vol 6 (2) ◽  
pp. 305-313 ◽  
Author(s):  
Tatiana Danilchuk ◽  
Tatiana Danilchuk ◽  
Vera Ganina ◽  
Vera Ganina
Keyword(s):  
Hydrolytic Enzymes ◽  
Physical Factor ◽  
Maximum Activity ◽  
Physical Factors ◽  
Experimental Sample ◽  
Low Doses ◽  
Resource Saving ◽  
Food Biotechnology ◽  
Low Intensity ◽  
Biotechnological Processes

The paper deals with urgent issues of development of resource-saving methods of biotechnological processes intensification. The main purpose of the work is to show the efficiency of using extremely low doses of physical factors impact in food biotechnology. Acoustic and electric treatment was in various modes. Impact capacity did not exceed 10-4 W/kg. The duration of exposure ranged from 5 to 15 min. Barley grains enzymes and lactic acid microorganisms were subjected to treatment. Impact of vibration as a physical factor, its frequency is considered as a priority in controlling growth and biochemical processes in biological objects. Impact frequency in the range of 50–10000 Hz influences the activity of hydrolytic enzymes in bimodal way. It is presented in the article. The coincidence of the frequency ranges of the maximum activity of enzymes in the model reactions with the ones in the grain of barley under the treatment of alternating current and sound is noted. Improvement of all indexes of germinating barley and improvement of the quality of the finished malt were observed in these ranges. Low-intensity acoustic treatment at a frequency of 2000 Hz contributed to an increase in β-galactosidase activity of the CT-95 Str. thermophilus strain. Selected ST-95 Str. thermophilus strain was used in the starter composition for the experimental sample production of fermented melted milk. The fermentation process intensification was observed. The lactose content of this product is 30% less in comparison with the feedstock. The use of traditional starter without a selected strain can reduce the lactose content by an average of 7.5%. The results of biotechnological processes modification by means of the treatment of enzymes and extremely low doses of physical factors impact used in meat technologies are observed. Thus, the prospects of using low-intensity physical effects of vibration in the development of innovative food technologies are substantiated. It is also promising to use these technologies in making absolutely new food products with different qualities.

scholarly journals Is the ultraviolet waveband a special communication channel in avian mate choice?

2001 ◽  
Vol 204 (14) ◽  
pp. 2499-2507 ◽  
Author(s):  
Sarah Hunt ◽  
Innes C. Cuthill ◽  
Andrew T. D. Bennett ◽  
Stuart C. Church ◽  
Julian C. Partridge
Keyword(s):  
Mate Choice ◽  
Communication Channel ◽  
Visible Spectrum ◽  
Short Wave ◽  
Zebra Finches ◽  
Long Wave ◽  
Single Cone ◽  
Coloured Filters ◽  
Uv Reflection

SUMMARYThere is growing evidence that ultraviolet (UV) wavelengths play an important role in avian mate choice. One of the first experiments to support this idea showed that female zebra finches (Taeniopygia guttata) prefer UV-reflecting males to males whose ultraviolet reflection has been removed. The effect was very strong despite little or no UV reflection from several plumage areas. However, it is not clear how the importance of the UV waveband compares to other regions of the bird-visible spectrum. We tested whether the response of female zebra finches to the removal of male UV reflection is greater than to the removal of other wavebands. We presented females with a choice of males whose appearance was manipulated using coloured filters. The filters removed single blocks of the avian visible spectrum corresponding closely to the spectral sensitivities of each of the zebra finch’s single cone classes. This resulted in males that effectively had no UV (UV−), no short-wave (SW−), no medium-wave (MW−) or no long-wave (LW−) plumage reflection. Females preferred UV− and SW− males. LW− and MW− males were least preferred, suggesting that female zebra finches show the greatest response to the removal of longer wavelengths. Quantal catches of the single cone types viewing body areas of the male zebra finch are presented for each treatment. Our study suggests it is important to consider the role of the UV waveband in avian mate choice in conjunction with the rest of the avian visible spectrum.

scholarly journals Люминесцентные свойства нестехиометрических кристаллов ниобата лития различного состава и генезиса (обзор)

2022 ◽  
Vol 130 (1) ◽  
pp. 171
Author(s):  
М.В. Смирнов ◽  
Н.В. Сидоров ◽  
М.Н. Палатников
Keyword(s):  
Wave Spectrum ◽  
Visible Region ◽  
Wavelength Region ◽  
Visible Spectrum ◽  
Luminescent Properties ◽  
Short Wave ◽  
Octahedral Cluster ◽  
Short Wavelength Region ◽  
Luminescence Centers ◽  
Near Ir

A brief review of the features of the defect structure and studies of the luminescent properties of nonlinear optical lithium niobate crystals of various compositions and genesis was given. It was established that the electron-hole pair NbNb4+-O- in the oxygen-octahedral cluster NbO6 emitted in the short-wavelength region of the visible spectrum (400-500 nm), while point defects (VLi and NbNb4+-NbLi4+ bipolarons) - in the long-wavelength region (500-620 nm). At the ratio of Li/Nb≈1 the luminescence was extinguished in the visible region of the spectrum due to decreasing the intrinsic luminescence centers. It was shown that the presence of polaron luminescence in the near-IR region (700-1050 nm) was due to the small polarons NbLi4+ and impurity ions Cr3+ localized in lithium and niobium octahedra. The energy transfer between the luminescence centers in the visible and near-IR spectral regions was detected. Moreover, luminescence in near-IR regions was dominant. Doping of LiNbO3 crystals with zinc and magnesium at ZnO<4.46 mol.% and MgO<5.29 mol.% led to decreasing luminescence of intrinsic defects (VLi, NbNb4+-NbLi4+). However, there was an increase of the contribution of the short-wave spectrum component at higher dopant concentrations because of the introduction of Zn and Mg into the origin positions of Nb ions.

scholarly journals Energy Efficient Routing based on Reliability for Mobile Ad hoc Network

2019 ◽  
Vol 8 (4) ◽  
pp. 5327-5330
Keyword(s):  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Data Communication ◽  
Physical Factor ◽  
Physical Parameters ◽  
Physical Factors ◽  
Quality Factors ◽  
Energy Efficient Routing ◽  
Performance Factors ◽  
And Performance

MANETs is a network which has nodes. Communication is done without use of infrastructure. Quality based routing is developed which considers end to end qualitatiove data communication. A number of protocols were designed and suggested by researchers to achieve effective communication in MANETs. Considering number of quality factors as energy, trust, bandwidth etc a number of protocols are existing. But still there are number of factors those can consider to enhance the performance of the protocols used for the communication purpose. The existing schemes were effective enough but still as factors those were considering only the resources held by a node not the physical factors were present as node is to survive and communication in network. So further enhancements were possible by considering the physical parameters. Inspired from that in this paper a proposed scheme considering physical factor name as Distance is considered as the improvement to the traditional scheme. The distance factor is behaving as finding the physical presence of the node in the network also the distance factor will help to find the appropriate node for the next hop to communicate. A simulation is conducted in MATLAB software and performance factors as throughput and energy are analyzed, also an comparison with existing system is done and the results shows that the proposed scheme is effective enough to achieve QOS based routing with reduced energy consumption and high throughput.

Modelling of Piezoelectric Transducers for Environmental Monitoring

2017 ◽  
Author(s):  
Constantine Bazilo ◽  
Alvydas Zagorskis ◽  
Oleg Petrishchev ◽  
Yulia Bondarenko ◽  
Vasyl Zaika ◽  
...  
Keyword(s):  
Environmental Monitoring ◽  
Quantitative Description ◽  
Well Being ◽  
Negative Influence ◽  
Piezoelectric Transducers ◽  
Piezoelectric Sensors ◽  
World Health ◽  
Physical Factors ◽  
Axially Symmetric ◽  
Health Organization

World Health Organization (WHO) defined health as being “a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity”. Physical factors (noise, vibration, electromagnetic fields, ionized radiation, etc.) may have a negative influence on both the environment and the health of population. Piezoelectric sensors have been employed in different fields such as medical analysis, environmental monitoring, etc. The object of the research is piezoelectric sensors for environmental monitoring and their simulation. Currently, there are no reliable and valid methods of constructing of mathematical models of piezoelectric transducers, which could be used as a theoretical basis for calculating characteristics and parameters of this class of functional elements of modern piezoelectronics. In most papers the described methods of transformers simulation are mostly based on the use of equivalent electrical circuits and it does not allow analysing stress-strain state of solids with piezoelectric effects. The final goal of mathematical modelling of vibrating piezoelectric elements is a qualitative and quantitative description of characteristics and parameters of existing electrical and elastic fields. Physical processes in piezoelectric transducers which occur using axially symmetric radial oscillations of piezoceramic disk are considered.

scholarly journals Hollow metal halide perovskite nanocrystals with efficient blue emissions

2020 ◽  
Vol 6 (17) ◽  
pp. eaaz5961 ◽  
Author(s):  
Michael Worku ◽  
Yu Tian ◽  
Chenkun Zhou ◽  
Haoran Lin ◽  
Maya Chaaban ◽  
...  
Keyword(s):  
Quantum Confinement Effect ◽  
Visible Spectrum ◽  
Precursor Solution ◽  
Metal Halide ◽  
Synthetic Control ◽  
Light Emitting ◽  
Perovskite Nanocrystals ◽  
Highly Efficient ◽  
Metal Halide Perovskite ◽  
Halide Perovskite

Metal halide perovskite nanocrystals (NCs) have emerged as new-generation light-emitting materials with narrow emissions and high photoluminescence quantum efficiencies (PLQEs). Various types of perovskite NCs, e.g., platelets, wires, and cubes, have been discovered to exhibit tunable emissions across the whole visible spectrum. Despite remarkable advances in the field of perovskite NCs, many nanostructures in inorganic NCs have not yet been realized in metal halide perovskites, and producing highly efficient blue-emitting perovskite NCs remains challenging and of great interest. Here, we report the discovery of highly efficient blue-emitting cesium lead bromide (CsPbBr3) perovskite hollow NCs. By facile solution processing of CsPbBr3 precursor solution containing ethylenediammonium bromide and sodium bromide, in situ formation of hollow CsPbBr3 NCs with controlled particle and pore sizes is realized. Synthetic control of hollow nanostructures with quantum confinement effect results in color tuning of CsPbBr3 NCs from green to blue, with high PLQEs of up to 81%.

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