scholarly journals Influence of building orientation on internal temperature in saharan climates, building located in Ghardaïa region (Algeria)

2013 ◽  
Vol 17 (2) ◽  
pp. 349-364 ◽  
Author(s):  
Sidi Bekkouche ◽  
Tayeb Benouaz ◽  
Mohamed Cherier ◽  
Maamar Hamdani ◽  
Mohamed Yaiche ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Thermal Insulation ◽  
Air Temperature ◽  
Thermal Inertia ◽  
Numerical Data ◽  
Internal Temperature ◽  
And Control ◽  
The Mathematical Model ◽  
Do So

In desert regions, the orientation of buildings has an important influence in the inside air temperature. In the present work, we carry out a study on the influence of the buildings orientation as well as the thermal insulation on the internal temperature. To do so, we have considered the case where only the exposed walls are isolated. The main objective of the current work is to determine the temperatures of the building in question with and without thermal insulation. This study aims at assessing also the geographic parameter enhancing or damping the role of thermal inertia, providing a variety of results. As result, this work proves that stones play a contradictory role on thermal comfort. We have verified that thermal insulation is specified to reduce heat transfer through the building. Concerning the orientation, results indicates that the variation in orientation does not influence significantly the internal air temperature of a well thermally insulated building. Moreover, in hot period, whatever orientation considered, the phenomenon of overheating presents a serious problem to minimize consumption of energy and control of indoor temperature in case of building without insulation. The numerical data was compared to the experimental measurements in order to validate the mathematical model. In conclusion, to achieve a better thermal comfort arid and semi arid regions, the habitation will have to be situated in south flan of a hill to satisfy the two strategies (hot and cold).

Museums and Web 2.0

2011 ◽  
pp. 1-15 ◽  
Author(s):  
Werner Schweibenz
Keyword(s):  
Social Media ◽  
Web 2.0 ◽  
User Participation ◽  
Significant Problem ◽  
Crucial Question ◽  
And Control ◽  
Do So

Many museums want to use Web 2.0 applications or feel the pressure to do so. In doing so, they might encounter a significant problem as Web 2.0 is based on the notion of radical trust and unrestricted, equal participation, two concepts that are contrary to the museum’s traditional concepts of authority, communication and participation. Until recently, museums presumed control of their content. The crucial question is how much control of its content the museum can afford to lose, since they depend on their reputation for expertise and trustworthiness. The paper analyses the role of authority, its influence on traditional and future museum communication and its effects on participation and trust. The challenge for museums is to find a way to cede authority and control over content without losing status as trustworthy institutions and to open up for social media and user participation in order to attract new audiences and maintain existing ones.

scholarly journals Control, Regulation and Command System of Hydronic Radiant Floors Heating by Wireless and Energy Harvesting Sensors and Actuators

2013 ◽  
Vol 543 ◽  
pp. 389-392 ◽  
Author(s):  
Gilberto Batista ◽  
Pedro Dinis Gaspar ◽  
Pedro D. Silva
Keyword(s):  
Energy Harvesting ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Heating System ◽  
Comfort Level ◽  
Sensors And Actuators ◽  
Control Regulation ◽  
Radiant Temperature ◽  
And Control ◽  
Actual Control

This paper presents the development of an innovative control, regulation and command system for hydronic radiant floors, more flexible and efficient that guarantees a better thermal comfort to the user and simultaneously improves the energy efficiency of this type of heating system. The majority of the actual control of hydronic radiant floors is done by thermostats that measure the air temperature and control the actuators (pumps and valves) in order to maintain the room at the specified temperature. These systems requires the frequent adjustment of thermostats set-point in order to obtain thermal comfort as it depends on other factors than just the air temperature, such as, the air humidity, external environmental conditions, radiant temperature, among others. This paper presents a control, regulation and command solution that requires minimum user intervention, as the user only has to choose the desirable thermal comfort level. The control algorithm is based on the calculation of PMV (Predicted Mean Vote) index as defined on Thermal Comfort Standard ISO 7730. Another advantage of the proposed system is related to the wireless and energy harvesting sensors and actuators that provide much more flexibility to the system.

A Control System on Soil Temperature

2014 ◽  
Vol 599-601 ◽  
pp. 673-679
Author(s):  
Shi Guo Chen ◽  
Li Hua Hu ◽  
Dong Sheng Wu ◽  
Xue Yong Chen
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Soil Temperature ◽  
Control Algorithm ◽  
Soil Ecology ◽  
Control Soil ◽  
Pid Algorithm ◽  
And Control ◽  
The Mathematical Model

The soil’s temperature plays an important role of soil ecology research. In order to gain and control soil’ temperature. A control system is proposed for soil’s temperature. And a new control algorithm which is based on the PID algorithm is designed in the control system to handle the complex change of the soil’s temperature. It does not need to know the mathematical model of soil’s temperature. At last, the control result is analyzed in this paper. The result shows that the soil’s temperature is controlled ideal by this control system which is accurate to 0.5°C.

scholarly journals Development and Application of a Thermal Comfort Model in Buildings

2022 ◽  
Vol 7 ◽  
pp. 1
Author(s):  
Andrés Vilaboa Díaz ◽  
Pastora M. Bello Bugallo
Keyword(s):  
Mathematical Model ◽  
Thermal Comfort ◽  
Thermal Inertia ◽  
Design Parameters ◽  
System Response ◽  
Thermal Mass ◽  
The European Union ◽  
External Temperature ◽  
Temperature Variations ◽  
The Mathematical Model

Buildings are one of the systems that more energy consumed in the European Union. The study of the thermal envelope is interesting in order to reduce the energy losses. For that, a mathematical model able to predict the system response to external temperature variations is developed. With the mathematical model, different thermal envelope elements of a building based on the lag and the cushioning of the resultant wave can be characterized. In addition, it is important to analyse where the insulation is placed, because when the insulation is outside and the thermal mass is inside, the system produces a response with smooth temperature variations than when the insulation is inside. Therefore, placing the outside insulation generates more steady indoor temperatures, increasing the thermal comfort inside the building. To complete the mathematical model that allows predicting the temperature inside a building taking into account the solar inputs and the thermal inertia of the building. This study will help to establish the optimum design parameters in order to build sustainable and comfortable buildings. Furthermore, it will take one step forward in the construction of nearly Zero-Energy Buildings.

scholarly journals Mathematical modeling bringing the operation of air split conditioners heat pumps to the same internal temperature conditions

2021 ◽  
Vol 8 (3) ◽  
pp. 509-514
Author(s):  
V. Yo. Labay ◽  
◽  
V. Yu. Yaroslav ◽  
O. M. Dovbush ◽  
A. Ye. Tsizda ◽  
...  
Keyword(s):  
Air Temperature ◽  
Heat Pumps ◽  
Thermodynamic Efficiency ◽  
Condensation Temperature ◽  
Internal Temperature ◽  
Heating Systems ◽  
Evaporation Temperature ◽  
Temperature Conditions ◽  
Heating Capacity ◽  
The Mathematical Model

Nowadays, the use of heat pumps (HP) of air split-conditioners in air conditioning and heating systems of small industrial, public and residential facilities is becoming more common. It is known that the nominal heat capacity of HP of air split-conditioners is given in catalogs or reference literature under standard outdoor temperature conditions, namely: outdoor air temperature +7oС, indoor air temperature +21oС. At the same time, manufacturers of air split-conditioners do not ensure that, regardless of the size of heating capacity, all air split-conditioners have the same internal temperature conditions, namely: the evaporation temperature of the refrigerant and its condensation temperature. In this case, the thermodynamic efficiency, which can be best assessed by the exergetic output-input ratio (OIR) of different heating capacity of HP of air split-conditioners, is different; this, in our opinion, is incorrect. However, today there is a lack of mathematical models of bringing the operation of air split-conditioners HP to the similar internal temperature conditions, which will allow us to obtain the same exergetic OIR for different heating capacity of HP. To create the mathematical model of bringing the operation of HP of air split-conditioners to the equal internal temperature conditions, we have proposed them, namely: the evaporation temperature of the refrigerant +0.7oC and its condensation temperature +40oC. Taking these temperatures on the basis of the heat balances of the HP evaporator and HP condenser of air split-conditioners, we obtained the dependences for calculating air flow rates on the evaporator and condenser, which respectively maintain the proposed temperatures.

scholarly journals Analysis of the possibilities for improvement of thermal comfort of living quarters located in multi-family large-panel prefabricated buildings

2018 ◽  
Vol 44 ◽  
pp. 00145
Author(s):  
Konrad Podawca ◽  
Agata Pawłat-Zawrzykraj ◽  
Marek Dohojda
Keyword(s):  
Twentieth Century ◽  
Real Estate ◽  
Thermal Comfort ◽  
Thermal Insulation ◽  
Air Temperature ◽  
Optimal Temperature ◽  
Large Panel ◽  
Before And After ◽  
Optimal Temperature Range ◽  
Family Building

The article discusses the issue of low thermal insulation of partitions in large-panel prefabricated buildings. They were constructed mainly in the 70's and the 80's of the twentieth century. Defects related to freezing as well as vertical and horizontal joints of prefabricated walls, began to appear as early as in the very first years of operation. It was very burdensome for flat users due to lack of thermal comfort, mycological problems and rising heating costs. The thermovision analysis covered sections of panel partitions in real estate at Lazurowa Street in Warsaw, which is a four-storey multi-family building, constructed in large-panel system. The measurements were carried out in the periods of January-February 2016 before the thermal modernization of the building, and in January 2018 after its modernization and renovation of the flat. Before-and-after comparison of thermal insulation state was made on the basis of surface temperatures of crucial spots. Furthermore, after changes in the structure of external walls were finished, thermal comfort or discomfort in the analysed room were visualised, using graphs of the optimal temperature range of walls, ceiling and floor, depending on the air temperature in the room.

The Parametric Analysis of the Threshold Value Judging Mechanism in MEMS Safety and Arming Device

2015 ◽  
Vol 645-646 ◽  
pp. 968-971
Author(s):  
Fu Fu Wang ◽  
Wen Zhong Lou ◽  
Fang Yi Liu ◽  
Da Kui Wang ◽  
Ming Rong Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Threshold Value ◽  
Element Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Long Distance ◽  
And Control ◽  
The Mathematical Model ◽  
The Finite Element Model

In this paper, a mechanical MEMS S&A device has been proposed. The size of the device is 10mm×13mm×0.5mm. The role of the threshold value judging mechanism is to determine the environment suffered by centrifugal force and control the sub-centrifugal slider not movement under the threshold, so as to effectively guarantee the time of long-distance arming. Through establishing the three-dimensional model of threshold value judging mechanism, establishing the force and the parameters of locking-releasing mechanism, deriving the mathematical model according to the rigid dynamic mechanics theory and establishing the finite element model by using ANSYS/LS-DYNA, appropriate threshold value judging mechanism is designed to meet two items, one item is the deformation of threshold value rod is not enough to release sub-centrifugal slider when the speed is less than 60000r/min; the other item is deformation of threshold value rod can release sub-centrifugal slider when the speed is more than 60000r/min.

scholarly journals The ambiguities of Brazil in the nuclear area and the Argentine "strategic patience” (2002-2010)

2020 ◽  
Vol 39 ◽  
Author(s):  
Hugo Rogelio Suppo ◽  
Leandro Gavião
Keyword(s):  
Nuclear Materials ◽  
Nuclear Area ◽  
Governmental Organization ◽  
The Face ◽  
And Control ◽  
Do So ◽  
Newspaper Articles

ABSTRACT This article discusses the ambiguities of Brazil regarding the nuclear area during the administrations of Luiz Inácio Lula da Silva. To do so, the text uses the speeches of important politicians and members of government bodies to analyze the erratic positioning of Brasília in the face of the commitments made with Argentina since the Quadripartite Agreement (1991) and the founding of the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC). Other source categories used are newspaper articles - Brazilian and international - and confidential files leaked by the non-governmental organization WikiLeaks. Finally, it is sought to evaluate the role of ABACC as an instrument to sustain the Argentinian “strategic patience” within the framework of the sensitive nuclear area.

scholarly journals Climate change and built environment - the role of urban greenery as a mitigation strategy in Greek urban areas

2021 ◽  
Vol 899 (1) ◽  
pp. 012018
Author(s):  
D Apostolopoulou ◽  
S Tsoka
Keyword(s):  
Climate Change ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Urban Areas ◽  
Heat Waves ◽  
Well Being ◽  
Climatic Conditions ◽  
Mitigation Strategy ◽  
Urban Greenery

Abstract Extreme thermal conditions and heat waves, as a result of global warming, have increased in recent years. Especially in the Mediterranean area, cities face higher temperatures during summer months which severely affect thermal comfort and citizens’ well-being. In this context, this study aims to evaluate the role of urban greenery as a mitigation strategy and focuses on its effect towards the improvement of the urban microclimate and thermal comfort under extreme summer conditions. To this aim, a typical square, located in Athens, Greece, has been chosen as a case study. The microclimatic conditions are evaluated for its present state and after an increase of 20% of soil surface and 30% of trees, while both current (i.e., 2020) and future summer climatic conditions (for the year 2060) are examined. It was also proposed that all the soil surfaces would be covered in grass. The potential air temperature, mean radiant temperature and surface temperature are analysed by simulation means, using the ENVI-met microclimate simulation tool. The results of this study showed that increasing the vegetation ratio inside the study area contributes to considerably lower surface temperatures, while a significant reduction on mean radiant and air temperature at the pedestrian level is also achieved, forming better microclimate conditions. Urban greenery is an important factor for healthy and resilient cities. Its presence can provide lower temperatures in the pedestrian level during summer months, reforming the microclimate. The outcomes of this study can be used by urban planners and stakeholders to improve environmentally urban areas, mitigate the results of climate change, and create resilient cities.

Fatalistic Tendencies: An Explanation of Why People Don't Save

2005 ◽  
Vol 4 (1) ◽  
Author(s):  
Stephen Wu
Keyword(s):  
World Values Survey ◽  
Household Savings ◽  
Behavioral Factors ◽  
Survey Of Consumer Finances ◽  
Savings Behavior ◽  
Consumer Finances ◽  
Cross Country ◽  
And Control ◽  
Do So

Abstract This paper uses data from the 2001 Survey of Consumer Finances (SCF) and the 2000 World Values Survey (WVS) to analyze the role of fatalism in determining household savings behavior. SCF respondents who feel that luck has played an important role in their financial affairs are more likely to realize their need to save, but are less likely to actually do so. Cross-country evidence from the WVS shows that those who believe they have little freedom and control over their lives are also less likely to save. The results hold after controlling for a number of demographic and behavioral factors, and are consistent across income and wealth levels.

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