99 research outputs found

    Near earth objects space observatory

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    In this Master Thesis we begin with an introduction about Near Earth Objects (NEOs). We start with the different kind of existing NEOs, and then we will focus more on which ones can represent the biggest hazard for Earth. Thus many studies suggest irrelevant number of meteorites hit the earth each year, but actually is very hard to know number of exact hit to Earth, but for introducing some meteors are caused by pea-sized of rock, for good estimated number of meteorites per year is necessary to carefully monitoring the meteorites per day in one area and finally extrapolate this data for all area of Earth, or find meteorites fall in to the dry regions and estimate for all area of Earth some valor. However, is so hard to find exact value because of different size ranges and all procedures have errors, but the estimate value of the mass of material that falls on Earth each year rang from 37000-78000 tons [23]. Most of this mass would come from dust particles. A study done in 1996 calculated that for objects in the 10 grams to 1 kilograms size range 2900-7300 kilograms per year hit Earth, furthermore, between 36 and 166 meteorites larger than 10 grams fall to Earth per million square kilometers per year. Thus that translates to 18000 to 84000 meteorites bigger than 10 grams falls to Earth. Nowadays different space agencies of several countries have their programs to detect hazardous NEOs, but in case of many of this agencies they need extra help from amateurs astronomers. Furthermore, all of this programs represent different disadvantages such as high cost of operation, no centralized data base and work with people that are amateurs and no depending to any agencies. New systems will be proposed to detect on time, the hazardous NEOs. These new systems are an answer for the actual issues to detect NEOs on time, and issues of the main official agencies to resolve their problems with this kind of the space objects. The system where is proposed here is a system based on the constellation of the satellites in the Low Earth Orbit (LEO), equipped with a Newtonian Telescope on board. Furthermore, this system had a ground stations and centralized database, thus that all information about NEOs compiled by satellites can be used for the space agencies to detect on time hazardous NEOs. The Satellites use low cost components and they are respectable to the environment, the function of the satellites will be determined during this thesis, although the LEO present some conditions, like drag, and depending the mass of the satellites, the orbit can be free after several orbits, when the satellites burn because of contact with drag. For design and simulation of the system we use required some specific tools like Solidworks for the 3D design and Moon2.0 for the orbital simulation, and finally we propose an alternative system to put our satellites in the orbit, with a system called QuickFast

    Measuring and modelling the energy demand reduction potential of using zonal space heating control in a UK home

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    Most existing houses in the UK have a single thermostat, a timer and conventional thermostatic radiator valves to control the low pressure, hot water space heating system. A number of companies are now offering a solution for room-by-room temperature and time control in such older houses. These systems comprise of motorised radiator valves with inbuilt thermostats and time control. There is currently no evidence of any rigorous scientific study to support the energy saving claims of these zonal control systems. This thesis quantifies the potential savings of zonal control for a typical UK home. There were three components to the research. Firstly, full-scale experiments were undertaken in a matched pair of instrumented, three bedroom, un-furbished, 1930s, test houses that included equipment to replicate the impacts of an occupant family. Secondly, a dynamic thermal model of the same houses, with the same occupancy pattern, that was calibrated against the measured results. Thirdly, the experimental and model results were assessed to explore how the energy savings might vary in different UK climates or in houses with different levels of insulation. The results of the experiments indicated that over an 8-week winter period, the house with zonal control used 12% less gas for space heating compared with a conventionally controlled system. This was despite the zonal control system resulting in a 2 percentage point lower boiler efficiency. A calibrated dynamic thermal model was able to predict the energy use, indoor air temperatures and energy savings to a reasonable level of accuracy. Wider scale evaluation showed that the annual gas savings for similar houses in different regions of the UK would be between 10 and 14% but the energy savings in better insulated homes would be lower

    National survey of summertime temperatures and overheating risk in English homes

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    AbstractThis paper presents one of the first national scale studies of summertime temperatures in English dwellings. Living room and bedroom temperatures were recorded in 207 homes across the England during the cool summer of 2007. Data was also collected by face-to-face household interviews. Fourteen homes (7%) were observed to be heated for part or all of the analysis period (July to August). Based on the BSEN15251 adaptive thermal comfort model, the 193 free-running dwellings would, in general, to be considered as uncomfortably cool. Over 72% of living rooms and bedrooms had more than 5% of hours below the BSEN15251 Cat II lower threshold, with over 50% having more than 5% of hours below the Cat III threshold. Detached homes and those built before 1919 were significantly cooler (p < 0.05) than those of other type and age. Static criteria revealed that, despite the cool summer, 21% of the bedrooms had more than 5% of night time hours over 26 °C; which is a recommended upper limit for bedrooms. The bedrooms of modern homes, i.e. those built after 1990 or with cavity walls, were significantly warmer (p < 0.05). The bedrooms in homes built prior to 1919 were significantly cooler (p < 0.05). The living rooms of flats were significantly warmer than the living rooms in the other dwelling types (p < 0.05). The incidence of warm bedrooms in modern homes, even during a cool summer, is of concern, especially as there is a strong trend towards even better insulation standards in new homes and the energy-efficient retrofitting of existing homes

    A comparison of calculated and subjective thermal comfort sensation in home and office environment

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    This study was conducted to investigate the accuracy of the PMV model in residential buildings in UK and to find out whether a true “context effect” exists in explaining discrepancies between predicted and observed thermal sensation of occupants. Sixteen participants were subjected to a thermal comfort study at both their homes and office. Each subject voted on their thermal sensation while air and mean radiant temperature, air velocity and relative humidity were recorded. The comparison of reported thermal sensation and those predicted using ISO 7730 showed that in general PMV under predicts the thermal sensation of occupants in both environments. The neutral temperatures found in homes and offices were respectively 3ºC and 2.5ºC lower than those predicted using ISO 7730. Together with 0.2ºC difference found between reported neutral temperatures at homes and offices, this suggests that there is a true context effect affecting occupants’ thermal sensation in different environments

    Heating controls scoping review project

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    This report summarises the findings of an evidence review of the energy savings, cost-effectiveness and usability of different types of heating controls

    Thermal Characterisation of composite walls made from waste Materials

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    Sustainable development has been an ever-growing global concern over the years, especially with respect to the environment. The construction sector is a major cause for concern due to the devastating effects traditional building materials, manufacturing processes and procurement, have on the environment. Inadequate housing in developing countries is also another major sustainable development challenge. These illustrate the cogent need for developing new methods of delivering sustainable housing that can be accessible to low-income communities who have little or no access to finances. This study compares the thermal performance of low-cost building components made from incorporating waste materials in cement blocks, thereby reducing the quantity of new materials needed. Three samples (wall panels) were made. Each panel was 330mm Ă— 330mm Ă— 240mm and incorporated 25 Ă— 500ml plastic bottles laid horizontally in rows. A sand and cement mixture (ratio 1:3) was used as a binder and filled the gaps between the plastic bottles. The bottles in the first sample were filled with sand, those in the second were filled with water, and those in the third with used plastic carrier bags. A guarded hot box was developed to experimentally measure the U-values of the samples following the BS EN ISO 8990 standards. It was observed that the samples with the plastic bags had the lowest U-value, about 60% lower than samples with sand. The results show a promising potential for low-grade plastic waste to be used as a means of improving the thermal performance of low-cost buildings

    National survey of summertime temperatures and overheating risk in English homes

    Get PDF
    This paper presents one of the first national scale studies of summertime temperatures in English dwellings. Living room and bedroom temperatures were recorded in 207 homes across the England during the cool summer of 2007. Data was also collected by face-to-face household interviews. Fourteen homes (7%) were observed to be heated for part or all of the analysis period (July to August). Based on the BSEN15251 adaptive thermal comfort model, the 193 free-running dwellings would, in general, to be considered as uncomfortably cool. Over 72% of living rooms and bedrooms had more than 5% of hours below the BSEN15251 Cat II lower threshold, with over 50% having more than 5% of hours below the Cat III threshold. Detached homes and those built before 1919 were significantly cooler (p<0.05) than those of other type and age. Static criteria revealed that, despite the cool summer, 21% of the bedrooms had more than 5% of night time hours over 26ÂşC; which is a recommended upper limit for bedrooms. The bedrooms of modern homes, i.e. those built after 1990 or with cavity walls, were significantly warmer (p<0.05). The bedrooms in homes built prior to 1919 were significantly cooler (p<0.05). The living rooms of flats were significantly warmer than the living rooms in the other dwelling types (p<0.05).The incidence of warm bedrooms in modern homes, even during a cool summer, is of concern, especially as there is a strong trend towards even better insulation standards in new homes and the energy-efficient retrofitting of existing homes

    Near earth objects space observatory

    Get PDF
    In this Master Thesis we begin with an introduction about Near Earth Objects (NEOs). We start with the different kind of existing NEOs, and then we will focus more on which ones can represent the biggest hazard for Earth. Thus many studies suggest irrelevant number of meteorites hit the earth each year, but actually is very hard to know number of exact hit to Earth, but for introducing some meteors are caused by pea-sized of rock, for good estimated number of meteorites per year is necessary to carefully monitoring the meteorites per day in one area and finally extrapolate this data for all area of Earth, or find meteorites fall in to the dry regions and estimate for all area of Earth some valor. However, is so hard to find exact value because of different size ranges and all procedures have errors, but the estimate value of the mass of material that falls on Earth each year rang from 37000-78000 tons [23]. Most of this mass would come from dust particles. A study done in 1996 calculated that for objects in the 10 grams to 1 kilograms size range 2900-7300 kilograms per year hit Earth, furthermore, between 36 and 166 meteorites larger than 10 grams fall to Earth per million square kilometers per year. Thus that translates to 18000 to 84000 meteorites bigger than 10 grams falls to Earth. Nowadays different space agencies of several countries have their programs to detect hazardous NEOs, but in case of many of this agencies they need extra help from amateurs astronomers. Furthermore, all of this programs represent different disadvantages such as high cost of operation, no centralized data base and work with people that are amateurs and no depending to any agencies. New systems will be proposed to detect on time, the hazardous NEOs. These new systems are an answer for the actual issues to detect NEOs on time, and issues of the main official agencies to resolve their problems with this kind of the space objects. The system where is proposed here is a system based on the constellation of the satellites in the Low Earth Orbit (LEO), equipped with a Newtonian Telescope on board. Furthermore, this system had a ground stations and centralized database, thus that all information about NEOs compiled by satellites can be used for the space agencies to detect on time hazardous NEOs. The Satellites use low cost components and they are respectable to the environment, the function of the satellites will be determined during this thesis, although the LEO present some conditions, like drag, and depending the mass of the satellites, the orbit can be free after several orbits, when the satellites burn because of contact with drag. For design and simulation of the system we use required some specific tools like Solidworks for the 3D design and Moon2.0 for the orbital simulation, and finally we propose an alternative system to put our satellites in the orbit, with a system called QuickFast

    The impact of human occupancy in thermal performance of a historic religious building in sub-humid temperate climate

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    The level of human occupancy in historic religious buildings influences the internal heat gains and thus the thermal comfort of the users. The temperate climate represents a challenge due to variations in tem- perature and relative humidity throughout the year, which are by no means extreme. Knowledge regard- ing human occupancy in historic religious buildings in temperate climates increases the possibilities of controlling and staying within a given comfort range for the users benefit. The objective was to determine the impact of occupancy on the thermal performance of a historic religious building located in sub-humid temperate climate, to increase the knowledge and to generate opportunities to decrease the excessive use of active systems prevalent today. The objective was approached with a numerical method that included monitoring periods and dynamic simulation to determine a novel passive cooling system that would maintain a determined comfort tem- perature for the longest time in summer. By implementing a novel passive cooling system, the results showed an impact on the operative temperature according to occupancy level, which reduced the cooling degree-hour by 80% and 66% at the upper occupancy with 80% and 90% satisfaction levels, respectively.Universidad de Granada / CBU

    Thermal Comfort Perception of Occupants in an Upcycled Bottle House in Abuja, Nigeria.

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    Several studies have shown that the use of upcycled materials for construction is a viable intervention for delivering affordable and adequate housing in low-income communities. However, information regarding in-situ performance of buildings made from upcycled materials is scarce in the literature. This paper compares the thermal performance of a building with walls made of sand-filled plastic bottles (Bottle House) with two other conventional buildings, one made of mud bricks (Mud House) and another made of sandcrete blocks (Cement House). In order to obtain the thermal sensation vote (TSV) of the occupants, thermal comfort questionnaires were developed based on ISO 7730 standard using the seven-point ASHRAE thermal sensation scale. Also, a Testo 480 multifunction meter which comprised of an anemometer, radiant globe thermometer, air thermometer, and Relative Humidity probe, was used to concurrently calculate the predicted mean vote (PMV). From the results of the thermal sensation votes (TSV) based on occupant’s survey, mean vote from participants of -2.0, 2.0 and 2.5 were observed for the bottle house, mud house and cement house respectively. In comparison, using the extended PMV thermal comfort model better suited for non-air-conditioned buildings in warm climates, adjusted PMV mean values of 1.9, 2.1 and 2.1 were recorded for the bottle house, mud house and cement house respectively. The TSV and PMV results both indicate that occupants of the bottle house felt more thermally comfortable when compared to occupants in the other dwellings. The results of this paper will provide evidence on the prospects of upcycling plastic waste for construction and its impact on occupant’s thermal comfort when compared to conventional building materials
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