Green roofs have become an important urban mitigation technology due to their ability to address multiple environmental issues. One of the most common benefits attributed to green roofs is the reduction in heating and cooling loads in buildings by dissipating heat through evaporation. This study focuses on evaluating the effect that evaporative cooling has on the thermal performance of green roofs. Sponge and floral foam were used as porous media for their ability to retain water inside its body, transport it to the surface, evaporate it at a constant rate and for their different pore sizes. Test trays containing sponge or floral foam saturated with water were tested in a low speed wind tunnel equipped to measure weight, temperature and heat flux. Two types of experiments were conducted: one with evaporation at the surface, and the other with evaporation blocked by an impervious layer. The testing conditions for all tests were kept constant except for the ability of evaporation to happen. Evaporation rate for floral foam was 0.14 kg/m2hr and 0.29 kg/m2hr for sponge. Results of tests with evaporation show a decrease of 45-49% in heat conducted through the roof when compared to the tests without evaporation. For optimal thermal performance of green roofs, a material that enhances water transport and thus evaporation at the surface is necessary with large pores and low field capacity. Surface temperatures on test with evaporation were found to be between 3-7°C lower than those without evaporation. Applying a 2 sample t-test to the data, the relationship between heat flux and evaporation was found to be statistically significant.

This study focuses on how green roof thermal performance is affected by the soil moisture in summer condition. It aims to determine whether moist soil is a better insulator during the summer months than dry soil. A soil model is developed to predict simultaneous conduction, convection, and surface evaporation for a layer of moist soil representing a green roof. It used to analyze evaporation process and its affect on the soil resistance. The model considers only bare soil without vegetation on the roof. The model predicts the soil surface temperature as it is affected by soil moisture content, which can then be used to calculate heat transfer through the soil layer. An experimental dry out test was conducted to measure the soil moisture and soil temperature histories. Comparison of the predicted and measured sol surface temperature shows that the model reasonably captures the actual behavior. The evaporative cooling effectively reduces the soil surface temperature and heat flux in moist soil and can be used as an effective way to insulate the roof.

Lachenalia cv. Ronina, a new flower bulb variety developed by the ARC-Roodeplaat Vegetable and Ornamental Plant Institute, has excellent characteristics as a flowering pot plant, but information on cultivation practices is limited. Temperature is the most important environmental factor regulating the growth cycle of this flower bulb, therefore three temperature regimes, representing a cool, moderate and warm winter climate, were chosen to manipulate floral development. During this study the bulb structure, development and growth were determined during the bulb preparation phase (year 1) and subsequently the morphology of the bulb was evaluated during the pot plant phase (year 2). Regarding the bulb structure and development, cultivar Ronina has a typical rhythmic, sympodial, modular growth. Bulb growth and module formation is affected by temperature. The low (L TR) and moderate (MTR) temperature regime, which represent the cool and moderate winter climate in South Africa were found to be the best temperature regimes for bulb production. The high (HTR) temperature regime caused bulbs to develop faster, but flower abortion occurred. At the end of the bulb preparation phase, daughter bulbs were observed in the axils of the leaf bases in bulbs of all three temperature regime treatments. Additional inflorescences from underdeveloped growth modules were detected in the axils of the inner leaf bases of bulbs of the high temperature regime. The bulbs as well as the roots are the main sinks for the carbohydrates, whereas the inflorescence and especially the leaves are the main source for soluble sugars. Due to the more stable temperature that was applied in the growth cabinets, the flowering date of bulbs in all three treatments flowered two months earlier than plants growing in the open. During this production phase, simultaneous flowering occurred more within bulbs that were subjected to the LTR during the bulb preparation phase. These bulbs also produced broader leaves with more spots on and better quality inflorescences with a longer keeping ability than those of the higher temperature regimes. A correlation was found between the leaf number and the number of inflorescences of plants in the pot plant phase, grown from LTR treated bulbs. The bulb fresh mass/size at the end of the bulb preparation phase cannot be used as a reliable criterion to predict the quality of the pot plant. By examining the bulb structure at the end of the bulb preparation phase, the quality of the pot plant can be predicted. / Thesis (PhD Agric (Horticultural Science))--University of Pretoria, 2007. / Plant Production and Soil Science / unrestricted

Aim: To present a literature review of the positive effects and overall reduction of depressive symptoms that an intervention such as therapeutic gardening has on individuals living within memory care facilities. Background: As most humans age, they often lose abilities or skills that they have had for their entire lives (e.g. driving, grooming, toileting, seeing and/or hearing). By implementing programs that involve therapeutic garden therapy, individuals with dementia who are at greater risk for clinical depressive symptoms may find that this alternative approach improves their symptoms. Methods: A comprehensive, electronic, literature search in the CINAHL database was completed and included the keywords therapeutic garden, horticulture therapy, and dementia or Alzheimer's. Information has been extracted from sources based on whether they met specific inclusion and exclusion criteria and if they showed positive effects of alleviating depressive symptoms within the defined population. The literature was critically analyzed and common themes were extracted to gain a deeper understanding of the existing research and presented as a written report. Significance: In 2018, dementia costs in the United States were upwards of $215 billion, and is said to potentially double by 2040 due to an increase in aging within the baby boomer generation (PRB, 2018). These numbers are spiking at a rapid rate which then leads to a rise in elderly individuals with dementia needing more specialized care. Memory care facilities assist with this care and are integrating newer non pharmacological ways to approach managing symptoms of dementia, such as Therapeutic Gardening. Conclusions: This review has shown proof from multiple studies that there are a large amount of positive findings when a therapeutic gardening intervention is applied to help the dementia population. The majority of the findings were related to an increase in an overall quality of life, but there were many other changes noted in individuals receiving this therapy including, but not limited to: reduction in agitation, positive changes in behavior, physical and mental health benefits, alleviation of social isolation, and potential changes in cortisol levels. Key words: Dementia, therapeutic gardening, depression

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Joseph Fels, a wealthy Philadelphia soap manufacturer, subscribed to Henry George's single tax economic theory that considered land a natural resource to be used for the good of all citizens. A hefty single tax levied on land values was intended to replace all other forms of taxation, in effect forcing landowners holding property for speculative purposes to use their land productively or make it available to others. In theory, wealthy land monopolists would be forced to pay an equitable share of taxes while the amount paid by the working class would be lowered to a proportionate level. Following the Panic of 1893 and the ensuing four year depression, urban gardening programs were established in major urban areas to support unemployed workers. In 1897 Joseph Fels helped to establish and finance the Philadelphia Vacant Lots Cultivation Association, and later, the Vacant Lots Cultivation Society in London, in addition to several farming colonies in the English countryside. He also financed several experimental living communities based on the single tax: Fairhope in Alabama, Arden in Delaware, and Rose Valley in suburban Philadelphia. In addition, Fels supported single tax candidates, and corresponded with national and international reformers including Samuel Gompers, Booker T. Washington, Beatrice and Sidney Webb, and George Bernard Shaw. Fels was an equitable employer, a philanthropist, and a reformer who campaigned fervently for the rights of the working class until he died in 1914 at age sixty. / History