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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Preventive conservation for paper-based collections within historic buildings

Bulow, Anna Elisabeth January 2002 (has links)
Previous research has been carried out concerning the conservation of both historic buildings and library and archive collections. Little work has, however, been undertaken to look at the interface between the two. The following research has been carried out in the context of an interdisciplinary project linking key disciplines in an examination of the issues relating to conservation problems in historic buildings used for library and archive purposes. This thesis presents a comprehensive literature review, evaluating published data on both the preservation of paper-based collections in libraries and archives, and preventive conservation of historic buildings and monuments. Emphasis is given to the interface between the two. Furthermore, a survey of British archives and libraries has been carried out, including the evaluation of questionnaire and site data. The survey focuses on preventive conservation measures as well as past and present problems of dampness. This survey proved problems with dampness to be often misdiagnosed and the consequences of damage underestimated. From the surveyed collections, two case studies have been selected for environmental monitoring in order to investigate macro- and micro-climates under different environmental conditions. Resulting data suggest that the micro-environment of a confined space is influenced by the amount of paper housed within it. This has assisted in explaining the interaction between paper and the immediate environment. At the same time, data has confirmed that the overall surface area of paper available for environmental interaction is more important than paper type or book size, with respect to the overall conditions within the storage space. Although degradation mechanisms of paper with respect to cycling conditions are not entirely clear, results of this study emphasise the importance of ventilation and dehumidification in order to avoid mould germination and/or growth. The data have been used to determine whether the internal environment of enclosed bookcases, and hence the immediate environment of the collection, can be adequately predicted from ambient data taken within the room. Mathematical models have been developed for both metal and wooden bookcases, and have shown that even when the ambient conditions are unstable, the relationship between ambient RH and the RH inside a book in an enclosed bookcase can be predicted within a 5% margin (1% for a stable environment).
2

Stubble management effects on microclimate and performance of canola across different climatic regions in Western Canada

Cardillo, Michael John 15 January 2014 (has links)
The climate of the Canadian Prairies is semi-arid, thus moisture is a limiting factor in canola production. Previous research indicates that the alteration of the early season microclimate using tall wheat stubble from the previous year can create more favorable conditions for canola to emerge. The objective of this research was to test this approach over a broad range of climatic conditions across western Canada. In 2011 & 2012 field sites were established in Kenton, Swan Lake MB, Indian Head, Swift Current, SK and Lethbridge, Falher and Grimshaw AB. At each site, large replicated plots of tall stubble cut at 50 cm height were compared to large replicated plots of short stubble cut at 20 cm tall. The treatments were statistically analyzed to determine their effects on microclimates on canola during the spring seeding and fall harvest. This data provided an assessment of the possible benefits that stubble management could have on canola across a broad range of climatic conditions.
3

Dynamic three-dimensional plant-microclimate simulation model 'Ecospace'

Harwood, Thomas David January 1996 (has links)
Growing plants modify the microclimate within which they grow by altering their physical structure. Thus individuals affect the subsequent growth of both themselves and competing neighbours. It is important that this feedback be represented in a model of dynamic vegetation change. A flexible generalised model "Ecospace" is presented, which was designed to be applicable to all terrestrial vegetation. The model uses a three-dimensional grid of hexagonal tiles to represent space above and below ground. Each individual plant may occupy one or more tiles within the grid. Any number of individuals may occupy each tile until all space is filled. Microclimate, comprising solar radiation, wind and temperature, is calculated for each tile. Plant growth depends on the microclimate of occupied tiles. Three different plant functional groups are represented. The current model can represent an area of up to 50 m2 for low shrub vegetation. However, at present, computer run time and restricted memory limits the volume which can practically be simulated. There is no fundamental reason why these limits could not be overcome. Some model runs are presented for heather plants growing under different structural and climatic regimes. Since the model represents the feedback of vegetation structure on microclimate, it is suitable for studies of the impact of changing weather patterns on ecosystems.
4

Carbon dioxide uptake of field-grown ash (Fraxinus-excelsior L.) trees exposed to ozone episodes

Williams, Julian January 1996 (has links)
No description available.
5

The influence of microclimate on the spatial distribution of flying insects

Peng, Renkang January 1991 (has links)
No description available.
6

Transport of Finished Heifers in Warm Ambient Temperatures: An Assessment of Trailer Microclimate and Animal Well-Being for Two Transport Distances

2013 May 1900 (has links)
The microclimate within naturally-ventilated transport trailers hauling Canadian cattle to slaughter was investigated by recording temperature and relative humidity in one-minute intervals during commercial transport. Conditions on the outside of the trailer (ambient), at the trailer ceiling and at the animal tag-level were monitored. These metrics were used to calculate humidity ratio and temperature humidity index (THI) to further investigate the moisture content of the air and the apparent thermal conditions within the vehicle, respectively. The trailer micro-environment was assessed between trailer compartments and between planes within a given compartment. Five commercial long-haul (940 km) and five commercial short-haul (85 km) warm weather journeys (average daily temperature 24.5°C) were conducted to represent common distances traveled by finished Canadian heifers during summer and early fall. Variations in temperature, THI and humidity ratio were evident within the trailer and the results illustrated the most challenging compartments, in terms of thermal environment, at the front of the trailer and on the top level. Thermal conditions were greater inside the trailer compared to ambient (average 1.97°C for long and short distances combined), greater at the animal-level compared to the trailer ceiling (3.03°C for long and short distances combined) and greater in the center plane compared to the outside walls during long distance journeys. The physiological effect of transport on the cattle was measured through on-going monitoring of vaginal temperature of focal heifers located throughout the trailer. Body temperature recordings showed the ability of the animals under these conditions to dissipate heat acquired through the loading period. Cattle transported long distance however showed a better ability to return to near-baseline body temperature values. Shrink, or body weight loss, was calculated by each compartment of animals for all journeys. Cattle that travelled further lost a greater percentage of body weight (P < 0.001) with values of 4.5% and 1.6% for long and short distances, respectively. Further, cattle located in compartments that had higher temperatures and greater moisture levels recorded in the microclimate data showed correspondingly increased body weight loss (P < 0.05) suggesting that the nose compartment in particular had a greater potential to induce thermal stress.
7

Investigating influences on plant ozone sensitivity using artificial neural networks

Balls, Graham Roy January 1996 (has links)
No description available.
8

Trees and microclimatic comfort : with special reference to Brasilia, Brazil

Cantuaria, Gustavo A. C. January 2001 (has links)
No description available.
9

The creation of a courtyard microclimate thermal model for the analysis of courtyard houses

Bagneid, Amr 15 May 2009 (has links)
This research is an effort to revive the use of courtyard housing clusters in a modern context, which were traditionally known for their distinctive passive cooling performance. The goal is to promote energy efficient design in hot-arid climates and temperate climates by reviving the use of courtyard housing clusters. The objective is to introduce a simplified thermal model that simulates the courtyard microclimate, which has been tested with actual field data from a case study house. The case study house was an indigenous courtyard house in Cairo, Egypt that was built around 1400 AD, having an area of about 5000 sq. ft. (i.e., comparable to the size of a single-family house) with heavy thermal mass. To accomplish this, a finite difference thermal network model was created for simulating the case study courtyard microclimate. The finite difference (FD) model showed validity as it calibrated very well against field data. This model allowed running parametric sensitivity studies on the courtyard thermal simulation factors: air change rates, thermal mass, solar absorption, wall and floor emissivity, ground temperature, cloud cover, and ambient air temperature. The results of the parametric analysis showed that the model was sensitive to variations in the air change rates, solar absorptivity, and ambient air (rooftop) temperatures. The courtyard microclimate model was then used in combination with thermal simulation software (DOE-2) to analyze the thermal performance of the case study house, which was also validated with measured field data. The DOE-2 program showed limitations when applied to the case study, non-conditioned building, and showed a convergence deficiency when simulating high thermal mass buildings. The DOE-2 program did not perform well in simulating the impact of changes in thermal mass as compared to previous published field measurements. The proposed combinations of the FD microclimate/DOE-2 simulation did not perform as well as the FD microclimate simulation. The FD courtyard microclimate simulation model with onsite data for calibration is advantageous in introducing for the first time the ability to perform computer simulations on any number of proposed courtyard design alternatives for reaching optimum thermal performance.
10

Pensionato bendruomenės mikroklimato optimizavimas / Optimization of boarding–house community microchlimate

Matulienė, Gražina 08 June 2004 (has links)
The subject of research work Microclimate of baarding – hause community. The aim of the work To make analisys of the communitys demands to improve microclimate. Tasks : 1. To analyze microclimate of institution as base effective work. 2. To reveal importance of teamwork while mobilizing human resources. 3. To generalize the stresses in social care work, which are condition competences and state of mind. 4. To present methods of social help while initiative to develop state of mind of the staff. 5. To make an overview of social worker as member of teamwork, who is ready to coordinate the process of betterment microclimate. Methods: analysis of the scientific literature, analysis of the official documents, questioning in oral and written. The practical adaptability of this paper: The administration of Panevėžys region after the acquaintance with magūter ideas can to initiative office of social worker as initiator and coordinator of management microclimate in care institution. The structure of the paper: Part of the paper generalizes the ideas from the scientific literature about the microclimate of organization and input of social worker in process of changing it.Part of the paper presents understanding of the teamwork, principles of formation and the role of social worker in it. Third part the author of the paper generalize stresses of staff in care institution on theoretic field. Here are presented methods of overcome different stresses.Fourth part of the... [to full text]

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