scholarly journals Diurnal variations of hormonal secretion, alertness and cognition in extreme chronotypes under different lighting conditions

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
L. Maierova ◽  
A. Borisuit ◽  
J.-L. Scartezzini ◽  
S. M. Jaeggi ◽  
C. Schmidt ◽  
...  
2019 ◽  
pp. 22-27
Author(s):  
Cenk Yavuz ◽  
Ceyda Aksoy Tırmıkç ◽  
Burcu Çarklı Yavuz

Today the number of office workers has reached to an enormous number due to the fast-growing technology. Most of these office workers spend long hours in enclosed spaces with little/no daylight penetration. The lack of daylight causes physiological and psychological problems with the workers. At this point lighting systems become prominent as the source and the solution of the problem. Photometric flicker event which arises in the lighting systems can sometimes become visible and brings a lot of issues with it. In this paper, an experimental work has been done to investigate the effect of flicker. For this purpose, the flicker values of 3 different experiment rooms for different lighting conditions and scenarios have been measured and a questionnaire study has been carried out in the experiment rooms with 30 participants. In conclusion, the effect of the flicker event on the volunteers have been classified and some methods have been proposed not to experience flicker effects.


2019 ◽  
pp. 4-8
Author(s):  
Tadej Glažar ◽  
Marjeta Zupancic ◽  
Samo Kralj ◽  
Robert Peternelj

The Real Estate Fund of Pension and Disability Insurance (Nepremicninski Sklad) in Slovenia, founded in1997 is the owner of 3255 properties in 116 locations throughout the country and is intended for solving housing issues of pensioners of 65 years or older and other elderly persons who are allowed independently to live. The lease contracts are concluded for an indefinite period of time. The aim and vision of the Fund is to improve the quality of life for the elderly tenants by adapting the living environment, the flats and surroundings according to the physical needs of aging tenants. Homes for seniors often have low light levels and poor light spectrum caused by fluorescent or incandescent lighting. Demographic changes in most European countries show rising average life expectancy which means that the number of people with weak visual capacity or visual impairment is increasing. Equally the risks of injuries due to poor lighting conditions are increasing, e.g. missing a step resulting in a hip joint fracture. Better lighting conditions are of critical importance for aging population, as stated also in the recently published CIE227:2017. To facilitate safe environment for the elderly, the Fund in 2013 initiated a lighting research study that should provide facts and evidence for a lighting standard for their own premises.


1962 ◽  
Vol 41 (4) ◽  
pp. 584-594 ◽  
Author(s):  
Dankwart Reinwein ◽  
Erich Klein

ABSTRACT The iodine metabolism was investigated in 29 patients with euthyroid non-endemic diffuse goiter. 1 to 14 days before thyroidectomy the patients received carrier-free 131I. The chemical iodine fractions (PBI, BEI and iodide) of the thyroid and the labelled iodine compound were analyzed by means of paper- and column chromatography. In one gland the total iodine content varied only by ± 19.6% of the average, the relative shares of PBI, BEI and iodide as well as that of the iodoamino acids being equal. Monoiodotyrosine, diiodotyrosine and thyroxine were found in the thyroid homogenate without hydrolysis. The homogenate after hydrolysis contained more iodotyrosines at the expense of iodothyronines than do normal glands. 17 goiters with normal 131I-uptake showed a high total iodine content (14.2 ± 5.0 mg) whilst 9 goiters with an increased 131I-uptake had low values (3.58 ± 0.6 mg). The opposite was found for the relative shares of BEI with the chromatographically isolated iodothyronines thyroxine, triiodothyronine and an unidentified iodine compound. Goiters with »high plasma PB131I« were characterized by a faster transfer of 131I into the more heavily iodinated compounds than is found in glands with a normal hormonal secretion rate. The highest values for the iodothyronines were found in goiters with increased 131I-uptake together with a high hormonal secretion rate. From this study it appears that the changes in the iodine-poor glands are due to a defective exo- or endogenous iodine supply. The observed alterations in iodine-rich glands are probably induced by a faulty iodine utilization characterized by an incomplete iodotyrosyl-coupling defect.


1983 ◽  
Vol 104 (2_Supplb) ◽  
pp. S177-S187
Author(s):  
J. Odink ◽  
H. Sandman ◽  
A.J. Speek ◽  
W.H.P. Schreurs

2018 ◽  
Author(s):  
Carmen Gabriela Barbu ◽  
Adrian Teodor Pienary ◽  
Alice Albu ◽  
Sorina Martin ◽  
Anca Sirbu ◽  
...  

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 418-418
Author(s):  
F. Rosa ◽  
J. S. Osorio ◽  
J. Lohakare ◽  
M. Moridi ◽  
A. Ferrari ◽  
...  

Author(s):  
Ya.N. MIGUNOV ◽  
V.V. ONUFRIEV

A model for calculating the voltage-current characteristic of a solar array in the presence of a temperature gradient by its photovoltaic converters and their variable illumination due to possible pollution under the action of space factors, including operation of electric rocket engines, is described. The model is based on the main equation of a solar cell. In this case both a one-dimensional and a two-dimensional temperature gradients are taken into account. The principles of constructing a model are given, and the initial data selection is made. To simulate the lighting conditions of the solar array such a concept as effective illumination is used, i.e. the density of the radiation flux which falls on photovoltaic converters passing through the protective coatings. The features of simulation of the temperature distribution in the solar array and the effective illumination of its surface in cases of parallel, serial and mixed switching of solar cells are described. The calculation procedures and examples of solar cells are given. The construction of the model in universal mathematical package Mathcad is described. Some simulation results are discussed. Key words: solar array, mathematical simulation, illumination, temperature gradient, electric rocket engine, spacecraft, Mathcad.


Author(s):  
Xiaolin Tang ◽  
Xiaogang Wang ◽  
Jin Hou ◽  
Huafeng Wu ◽  
Ping He

Introduction: Under complex illumination conditions such as poor light sources and light changes rapidly, there are two disadvantages of current gamma transform in preprocessing face image: one is that the parameters of transformation need to be set based on experience; the other is the details of the transformed image are not obvious enough. Objective: Improve the current gamma transform. Methods: This paper proposes a weighted fusion algorithm of adaptive gamma transform and edge feature extraction. First, this paper proposes an adaptive gamma transform algorithm for face image preprocessing, that is, the parameter of transformation generated by calculation according to the specific gray value of the input face image. Secondly, this paper uses Sobel edge detection operator to extract the edge information of the transformed image to get the edge detection image. Finally, this paper uses the adaptively transformed image and the edge detection image to obtain the final processing result through a weighted fusion algorithm. Results: The contrast of the face image after preprocessing is appropriate, and the details of the image are obvious. Conclusion: The method proposed in this paper can enhance the face image while retaining more face details, without human-computer interaction, and has lower computational complexity degree.


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