Daylight in Underground Spaces

2018 ◽  
pp. 156-161
Author(s):  
Alexei K. Solovyov
Keyword(s):  
Light Guide ◽  
Heat Losses ◽  
Internal Environment ◽  
Method Of Calculation ◽  
Natural Lighting ◽  
Different Depths ◽  
The Common ◽  
Different Diameters

Underground spaces in town centres present a big attraction for investors. However, they put special requirements to the internal environment. Those requirements can be fulfilled by means of daylighting. Examples of lighting of underground spaces are discussed. It is shown that the common systems of natural lighting are not always possible to use and cause big heat losses. Hollow light guide pipes allow avoid the shortcomings of common daylight systems. Method of calculation of daylight factors from hollow light guide pipes is shown. The results of calculation of daylight factors under the light guide pipes of different diameters in the different depths are presented.

scholarly journals Corrected μβ for stars of Hipparcos catalogue from independent latitude observations over many decades

2011 ◽  
pp. 35-41 ◽  
Author(s):  
G. Damljanovic ◽  
I.S. Milic
Keyword(s):  
International Organizations ◽  
Sufficient Accuracy ◽  
Proper Motions ◽  
Earth Orientation Parameters ◽  
Method Of Calculation ◽  
The Earth ◽  
Hipparcos Catalogue ◽  
International Polar ◽  
The Common ◽  
Orientation Parameters

During the last century, there were many so-called independent latitude (IL) stations with the observations which were included into data of a few international organizations (like Bureau International de l'Heure - BIH, International Polar Motion Service - IPMS) and the Earth rotation programmes for determining the Earth Orientation Parameters - EOP. Because of this, nowadays, there are numerous astrometric ground-based observations (made over many decades) of some stars included in the Hipparcos Catalogue (ESA 1997). We used these latitude data for the inverse investigations - to improve the proper motions in declination ?? of the mentioned Hipparcos stars. We determined the corrections ??? and investigated agreement of our ?? and those from the catalogues Hipparcos and new Hipparcos (van Leeuwen 2007). To do this we used the latitude variations of 7 stations (Belgrade, Blagoveschtschensk, Irkutsk, Poltava, Pulkovo, Warsaw and Mizusawa), covering different intervals in the period 1904.7 - 1992.0, obtained with 6 visual and 1 floating zenith telescopes (Mizusawa). On the other hand, with regard that about two decades have elapsed since the Hipparcos ESA mission observations (the epoch of Hipparcos catalogue is 1991.25), the error of apparent places of Hipparcos stars has increased by nearly 20 mas because of proper motion errors. Also, the mission lasted less than four years which was not enough for a sufficient accuracy of proper motions of some stars (such as double or multiple ones). Our method of calculation, and the calculated ?? for the common IL/Hipparcos stars are presented here. We constructed an IL catalogue of 1200 stars: there are 707 stars in the first part (with at least 20 years of IL observations) and 493 stars in the second one (less than 20 years). In the case of ?? of IL stars observed at some stations (Blagoveschtschensk, Irkutsk, Mizusawa, Poltava and Pulkovo) we find the formal errors less than the corresponding Hipparcos ones and for some of them (stations Blagoveschtschensk and Irkutsk) even less than the new Hipparcos ones.

Possible Solutions for Ground Slabs of Energy Efficient Buildings

2014 ◽  
Vol 1041 ◽  
pp. 105-108
Author(s):  
Anna Sedláková ◽  
Pavol Majdlen ◽  
Ladislav Ťažký
Keyword(s):  
Energy Efficiency ◽  
Heat Flow ◽  
Thermal Comfort ◽  
Energy Efficient ◽  
Direct Contact ◽  
Thermal State ◽  
Building Envelope ◽  
Heat Losses ◽  
Internal Environment ◽  
Energy Efficient Buildings

The building envelope is a barrier that separates the internal environment from the effects of weather. This barrier ought to facilitate the optimal comfort of the interior environment in winter as well as summer. It has been shown in practice that most building defects occur within the building envelope. This includes external walls, roofs and floors too, and is impartial to new or renovated buildings. Heat losses of buildings through external constructions – roof, external walls, ground slabs are not negligible. It is therefore important to pay more attention to these construction elements. Basementless buildings situated on the ground are in direct contact with the subgrade and its thermal state. An amount of heat primarily destined for the creation of thermal comfort in the interior escapes from the baseplate to the cooler subgrade. The outgoing heat represents heat losses, which unfavourably affect the overall energy efficiency of the building. The heat losses represent approximately 15 to 20 % of the overall heat losses of the building. This number is a clear antecedent for the need to isolate and minimalize heat flow from the building to the subgrade.

scholarly journals Problems of natural lighting for deepened buildings and underground premises under screen effect of high-rise construction

2018 ◽  
Vol 33 ◽  
pp. 02017
Author(s):  
Kira Larionova ◽  
Sergey Stetsky
Keyword(s):  
Theoretical Calculations ◽  
Research Work ◽  
Experimental Studies ◽  
Screen Effect ◽  
Lighting System ◽  
Method Of Calculation ◽  
Natural Lighting ◽  
High Rise ◽  
Urban Territories ◽  
New Formula

The main rationale and objective of the submitted research work is to create a quality lighting environment in the premises of deepened buildings and below-ground structures under screen effect of high-rise construction (high-rise buildings). It is noted, that in modern megapolises, a deficiency of vacant urban territories leads to the increased density of urban development with increased amount of high-rise construction and tendency to increase efficiency in the use of underground space. The natural lighting of premises in underground buildings and structures is the most efficient way, but it can be implemented only under use of roof lighting system in the form of roof monitors or skylights. In this case the levels of indoor natural lighting will be affected with serious screening effect of high-rise buildings in surrounding development. Such an situation is not regulated, or even considered by the contemporary building Codes and Regulations on natural lighting of interiors. The authors offered a new formula for a daylight factor calculation with roof lighting system in the described cases. The results of theoretical calculations and experimental studies showed very similar values. This proved the truth of the offered formula and elaborated method of calculation on the basis of an offered hypothesis. It prooves, that it is possible to use some factor and guide points in the daylight factors design under system of side natural lighting in the same design for a system of roof lighting.

scholarly journals A COMPREHENSIVE COMPARISON CRITERION OF NATURAL LIGHTING SYSTEMS FOR BUILDINGS

2019 ◽  
Vol 4 (3) ◽  
pp. 35-43
Author(s):  
Марина Кононова ◽  
Marina Kononova ◽  
Мария Жерлыкина ◽  
Mariya Zherlykina ◽  
Анастасия Малышева ◽  
...  
Keyword(s):  
Significant Contribution ◽  
Heat Losses ◽  
Operating Costs ◽  
Customer Requirements ◽  
Capital Costs ◽  
Natural Lighting ◽  
Complex Criterion ◽  
Comprehensive Comparison ◽  
Lighting Systems ◽  
The Individual

Natural lighting systems make a significant contribution to the energy balance of the building. Changing its geometric and optical characteristics affects the illumination in the room and determines the operating costs associated with maintenance, heat and heat losses through translucent fences. The problem of comparison several systems of natural lighting of buildings is considered. For comparison, a complex criterion is proposed that takes into account optical, thermal, operational properties, as well as capital costs. The proposed criterion allows to remove irrelevant indicators for a particular building or add new ones according to customer requirements. The calculated dependences to determine the numerical values of the individual coefficients included in the complex criterion are given. The calculated dependences to determine the numerical values of the individual coefficients included in the complex criterion are presented. The algorithm and the method of application the proposed complex criterion for comparison of natural light systems are developed.

scholarly journals About one method of calculation in the arbitrary curvilinear basis of the Laplace operator and curl from the vector function

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
S. O. Gladkov
Keyword(s):  
Simple Algorithm ◽  
Coordinate Systems ◽  
Method Of Calculation ◽  
Orthonormal Bases ◽  
Christoffel Symbols ◽  
Arbitrary Base ◽  
Cylindrical Coordinate ◽  
The Common ◽  
The Laplace Operator ◽  
Made In

Abstract A simple algorithm for calculating Christoffel symbols, a covariant projection of the result of the Laplace operator's action on the vector, vector curl and other similar operations in an arbitrary oblique base are proposed. For an arbitrary base with ortho ei is found the expressions of vector projections (ΔA) i and (rot A) i , where A is a counter variant vector. Examples of orthonormal bases are considered and general expressions for (ΔA) i and (rot A) i for the bases are also given. As a demonstration of the working capacity of the common formulas obtained, detailed calculations of (ΔA) i and (rot A) i as an example are made in cases of spherical and cylindrical coordinate systems.

The Effects of Vertical Gradient of Disparity and Combination Mode of Features on the Occurrence of Double Fusion in Panum's Limiting Case

Perception ◽  
10.1068/p6666 ◽  
2012 ◽  
Vol 41 (11) ◽  
pp. 1299-1314 ◽  
Author(s):  
Huayun Li ◽  
Ying Xie ◽  
Shengming Li ◽  
Shuiqing Xie ◽  
Chuang Gao ◽  
...  
Keyword(s):  
Vertical Gradient ◽  
Experimental Results ◽  
Common Basis ◽  
Single Feature ◽  
Different Depths ◽  
The Common ◽  
Opposite View ◽  
Combination Mode ◽  
Limiting Case ◽  
Fusion Theory

Panum's limiting case generally refers to the phenomenon that two features presented to one eye and a single feature presented to the other are combined and then perceived as two features at different depths. It is still not clear why experimental results derived from the Panum-type configuration (all lines parallel) support a double fusion viewpoint, but they do not for the Wheatstone-type configuration (one line not parallel to the others). Some experimental results support the double fusion theory, while others do not, even under a small disparity. Here we report that, under a small disparity, when the vertical gradients of the horizontal disparity of dichoptic feature pairs in previous Wheatstone-type configurations were increased or decreased, the evidence which was considered to be very convincing in previous studies, either supporting or against the double fusion viewpoint, was challenged, and even turned to support the opposite view. Moreover, it was discovered that changes in the way features were arranged altered the results. Together, these results indicate that double fusion is the common basis for all kinds of Panum-type configurations. But for the Wheatstone-type configurations double fusion is also constrained by the vertical gradient of disparity of the configurations in addition to disparity and influenced by the degree of similarity/conflict between binocular cues and monocular cues resulting from different arrangements of features.

scholarly journals Light Pipe Comparative Study

2019 ◽  
Vol 14 (1) ◽  
pp. 17-26
Author(s):  
Ayodeji Omishore ◽  
Petr Mohelník ◽  
Denis Míček
Keyword(s):  
Light Guide ◽  
Light Transmission ◽  
Test Chamber ◽  
Field Testing ◽  
Measured Data ◽  
Light Transmittance ◽  
Temperate Climate ◽  
The Common ◽  
Light Guides ◽  
Reduced Light

Abstract Results of daylight illuminance measurements of the field testing of two light guides with different roof installations is presented in the article. The first one is a common tubular system with a glass roof dome and the second one is a new light guide prototype with a concentrator head. The daylight illuminance was measured in a test chamber with the light guides installation. The measurements were carried out at the end of a summer season from August to September 2017. The measured data show differences in the daylight illuminance of the two tested light guides. The measured data were compared with simulation outputs in software Holigilm. In summary, it was found that the common light guide is about 37 percentage more efficient in light transmittance compared to the new light guide prototype. In temperate climate with dominant cloudy and partly cloudy daylight conditions the common light guide transmitted more light that the device with the concentrator head which reduced light transmission much more.

scholarly journals A Hypogene Karst Development Pattern Controlled by the Deep-Cycle of Groundwater in the Syncline in Huanjiang, Guangxi, China

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 199
Author(s):  
Hongqi Dong ◽  
Yong Dan ◽  
Jiapeng Liang ◽  
Bin Liang ◽  
Guoquan Nie ◽  
...  
Keyword(s):  
Meteoric Water ◽  
Circulation Pattern ◽  
Development Pattern ◽  
Karst Water ◽  
Karst Groundwater ◽  
Karst Springs ◽  
Engineering Construction ◽  
Karst Development ◽  
Different Depths ◽  
The Common

Hypogene karst is a special manifestation of karst development in spatial scale. Intensive study of its development mechanism has significant meaning for engineering construction, shale gas and geothermal exploitation. To reveal the developing pattern of hypogene karst in Huanjiang syncline, karst groundwater at different depths in wells HD1-2 and HD1-4 and karst springs was selected as the research object. Through the analysis of geochemistry and stable isotopes of karst groundwater, it was revealed that the circulation pattern of deep karst water came from the common recharge of meteoric water and fossil water hosted in karst caves, runoff of deep faulting belts and discharge of large karst springs, over Huanjiang syncline, which provides good hydrodynamic conditions for hypogene karst development. Meanwhile, the widely developed faulting belts and structural fissures provide primitive dissolution space. Through the above analysis, the paper constructs a hypogene karst development pattern controlled by the deep cycle of groundwater in Huanjiang syncline.

scholarly journals Capability measurement of non-standard parameters of manufacturing processes

2021 ◽  
Vol 1199 (1) ◽  
pp. 012089
Author(s):  
R Turisova ◽  
S Markulik
Keyword(s):  
Necessary Conditions ◽  
Classical Method ◽  
Random Variable ◽  
Customer Relationships ◽  
Manufacturing Processes ◽  
Manufacturing Companies ◽  
Method Of Calculation ◽  
Product Parameter ◽  
The Common ◽  
Quality Production

Abstract Capability measurement of manufacturing processes creates basic attributes for the production of conformity products, those that meet the necessary conditions in terms of tolerance limits for all important parameters. They are also important in the supplier-customer relationships context as one of the important easily predictable but highly effective indicators of the quality production of delivered products. In many manufacturing companies, the capability measurement is performed by using capability indicators, where the method of calculation is based on the assumption of normality of the distribution of the measured product parameter, as well as the assumption of constant median value but also variability during the monitored period. However, in practice we often are able to see such parameters of manufacturing products or processes, which do not meet the expectations required in the classical method of capability indexes calculation. The problems are usually in a different than normal models of the distribution of a random variable representing a specific parameter of a product or process, as well as in the excessive variability of median values during the time in these so-called non-standard parameters. There will be presented on the particular manufacturing product, how certain non-conformities occur during the capability indexes measurement indices in the classical way for selected non-standard parameters. The paper describes how it is possible to modify the common method of calculating the mentioned capability indexes in a simple way so that they are applicable in specific production conditions.

Wave Induced Hydrodynamic Forces on Vertical Piggyback Risers

2002 ◽  
Author(s):  
Robert Olsen ◽  
Shan Huang
Keyword(s):  
Reynolds Numbers ◽  
Hydrodynamic Forces ◽  
Wave Forces ◽  
Close Proximity ◽  
Different Depths ◽  
Mean Water Level ◽  
Drag And Lift ◽  
Different Diameters ◽  
Vertical Cylinders ◽  
Wave Induced

The wave induced hydrodynamic forces on a pair of vertical cylinders of different diameters in close proximity are investigated experimentally. The smaller cylinder is placed at various positions around the larger one. The wave forces, including both drag and lift, are measured on each cylinder independently at two different depths below the mean water level for each cylinder. The Keulegan-Carpenter numbers vary from 0.4 to 14 based upon the larger cylinder diameter and the Reynolds numbers are in the sub-critical regime. It is found that there is significant interference effect upon the cylinder drag and inertia coefficients.

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