11 research outputs found

    Green roof substrates: Effect of recycled crushed porcelain and foamed glass on plant growth and water retention

    No full text
    A study was conducted in a controlled environment greenhouse to examine the potential of recycled crushed porcelain and foamed glass for use as a component of green roof substrates. Porcelain and foamed glass substrates were compared to heat-expanded shale which served as the control. Each finished substrate was analyzed per German FLL guidelines to determine granulometric distribution, bulk density, total porosity, water-holding capacity, saturated hydraulic conductivity, pH, soluble salts, organic matter content, and cation exchange capacity. Both substrates met FLL Guidelines except the porcelain substrate contained a greater percentage of larger particles and its maximum water holding capacity was lower than recommended. Two plant species were used in the study, Sedum album (stonecrop) and Ocinum x citriodolum (lemon basil). Data collected included substrate volumetric moisture content (VMC), plant growth, biomass accumulation, and plant stress as measured by chlorophyll fluorescence. Substrate VMC was generally greater in shale than in foamed glass or porcelain. At the end of the study plant growth index was greatest for stonecrop growing in shale, but there was no difference among the substrates for basil. However, plants of both basil and stonecrop accumulated the most total biomass when grown in shale. It is probable that water retention could be improved for both recycled crushed porcelain and foamed glass if more attention was paid to reducing particle size during processing. If so, then they may perform equal to heat expanded shale when incorporated into green roof substrates. In the case of porcelain, its use could divert some waste from landfills and greatly reduce the embodied energy required to construct a green roof. (C) 2016 Elsevier GmbH. All rights reserved

    Quantitative assessment of rain gardens: A case study in Istanbul University Faculty of forestry

    No full text
    Deterioration of natural water cycle caused by urbanization brings necessities to use proper water management tools in cities. Rain gardens are one of the most essential tools in cities which can be defined as a new concept in Turkey. Those systems can be interpreted as green areas which can mitigate urban runoff. In this study rain gardens were evaluated through experimental methods. Three identical Rain Garden Modules (RGM) were constructed which represents a typical rain garden system were located on the site. Three plant species (Anemone nemorosa, Viola odorata, Iris germenica) that were determined as ecologically suitable for environmental conditions of the study area and rain garden system were evaluated in terms of plant growth and survival during study. In addition, soil moisture levels, infiltration and water retention abilities of the rain gardens were evaluated along with the environmental conditions. It was concluded that Viola odorata and Iris germenica are good candidates for rain gardens in Istanbul climate. However Anemone nemorosa was negatively influenced by dry periods. Findings of this study confirms that rain gardens are sustainable systems in Istanbul environment. Therefore by using proper application techniques integration of those systems into city infrastructure will bring positive effects to urban water management

    Effect of substrate depth, vegetation type, and season on green roof thermal properties

    No full text
    It is generally accepted that green roofs can influence thermal properties of a building, but there is some disagreement on the role that substrate depth and plant species plays in this equation. A study was conducted over a second floor roof in East Lansing, MI, comparing prevegetated mats of a mixture of sedum (depth = 5 cm) to a deeper roof (depth = 20 cm) planted with a mixture of 17 herbaceous perennials and grasses. Both roof sections were instrumented with heat flux sensors, thermocouples, moisture sensors, and infrared sensors, and ambient weather conditions were also continuously recorded by a weather station located on the roof. Data were collected for the period of almost a year to cover all four seasons. Also, the roofs were well established and had reached near 100% plant coverage by the time data collection commenced two years after planting. Most of the differences in temperatures and heat flux through the roof occurred during the summer or winter. During summer, the shallow sedum roof experienced more extreme fluctuations in diurnal substrate temperatures which tended to be warmer during the day, but cooler at night. Heat penetrating into the building on the sedum portion of the roof was consistently greater than the herbaceous section during the afternoon. However, during the night and early morning, heat gain into the building was greater on the herbaceous roof, especially on cloudy and rainy days. During winter, heat transfer through the sedum portion of the roof was affected more by outside environmental conditions, whereas the herbaceous portion of the roof was stable. Although, the sedum roof exhibited more extremes, when daily heat flux values were totaled for each month and each season, the herbaceous roof actually experienced more heat entering the building during the summer, but less heat escaping the building during the winter. This is an advantage during the winter months as the herbaceous roof would reduce heating costs. However, contrary to conventional logic that plants with high transpiration rates are superior, during the summer months the sedum roof outperformed the herbaceous roof. (C) 2017 Elsevier B.V. All rights reserved

    Effect of substrate compost percentage on green roof vegetable production

    No full text
    Use of rooftops to produce locally grown vegetables is increasing. However, due to weight restrictions, shallow substrate depths, and potential harsh environmental conditions, optimizing production can be a challenge. Standard industry practices for ornamental extensive green roofs planted with succulents or other herbaceous perennials and grasses dictate that organic matter should be less than 20% of the original substrate mix. In rooftop agriculture, however, maximizing growth and yields are usually a primary objective and the amount of organic matter incorporated into these substrates are a major factor in this equation. In this study we quantified the optimal percentage of compost in a green roof substrate for optimizing growth and yields for cucumbers (Cucumis sativus) and peppers (Capsicum annuum). The study was conducted on raised green roof platforms over a period of 19 weeks and compared six substrates containing increasing amounts of a commercial compost produced from municipal yard waste (0, 20, 40, 60, 80, and 100%) mixed with a heat-expanded shale and sand base. These treatments were also compared to a typical garden plot at ground level. Plant performance evaluations such as plant growth, chlorophyll fluorescence (Fv/Fm) as an indicator of plant stress, and fruit yields were used as an indicator for optimal substrate mixtures. Generally, the addition of 60 or 80% compost resulted in the greatest plant growth and fruit yields, although compost influenced growth and yield of peppers to a greater degree than cucumbers. In addition, the ground garden plots performed poorly which emphasizes the point that growing vegetables on a rooftop can be advantage because substrates can be engineered to maximize plant health, although the same could be done with raised beds in a garden plot. (C) 2015 Elsevier GmbH. All rights reserved

    High accuracy monitoring system to estimate forest road surface degradation on horizontal curves

    No full text
    Well-maintained pavements reduce occurring severe accidents on horizontal curves. For this reason, the monitoring and evaluation of pavement conditions are important. This study evaluates pavement conditions considering volumetric degradation or displacement on 11 horizontal curves in forest roads, depending on meteorological conditions, traffic effects, and curve parameters. Within this context, pavement displacement (degradation) was investigated and measured with terrestrial laser scanning (TLS) for a year on a monthly basis. In this study, two multiple regression models were developed to estimate the degradation values of a forest road. According to model 1, which was developed to estimate the loss volume values, the adjusted R-2 was 0.658. For model 2, which was developed to estimate the gain volume values, the adjusted R-2 was 0.490. Validations of models were evaluated with different statistical tests. In conclusion, volumetric degradation can be calculated with TLS-based data. Forest road designers should determine horizontal curve characteristics, taking into consideration the pavement degradation and traffic safety

    Short term monitoring of forest road pavement degradation using terrestrial laser scanning

    No full text
    Degradation on the forest roads have an important factor for the traffic safety and the safe drive of the vehicles. The aim of the study is to determine accurately the degradation rate of the pavement with high precisions, exposed to deformation by meteorological conditions in the short term, on the forest roads using with ZF 5010C Terrestrial Laser Scanner (TLS)

    The Carotid Endarterectomy Cadaveric Investigation for Cranial Nerve Injuries: Anatomical Study

    No full text
    Cerebral stroke continues to be one of the leading causes of mortality and long-term morbidity; therefore, carotid endarterectomy (CEA) remains to be a popular treatment for both symptomatic and asymptomatic patients with carotid stenosis. Cranial nerve injuries remain one of the major contributor to the postoperative morbidities. Anatomical dissections were carried out on 44 sides of 22 cadaveric heads following the classical CEA procedure to investigate the variations of the local anatomy as a contributing factor to cranial nerve injuries. Concurrence of two variations was found to be important in hypoglossal nerve injury: the presence of a direct smaller vein in proximity of the carotid bifurcation, and the intersection of the hypoglossal nerve (HN) with this vein. Based on the sample investigated, this variation was observed significantly higher on the right side. Awareness of possible anatomical variations and early ligation of any small veins can significantly decrease iatrogenic injury risk

    Effect of substrate compost percentage on green roof vegetable production

    No full text
    Use of rooftops to produce locally grown vegetables is increasing. However, due to weight restrictions, shallow substrate depths, and potential harsh environmental conditions, optimizing production can be a challenge. Standard industry practices for ornamental extensive green roofs planted with succulents or other herbaceous perennials and grasses dictate that organic matter should be less than 20% of the original substrate mix. In rooftop agriculture, however, maximizing growth and yields are usually a primary objective and the amount of organic matter incorporated into these substrates are a major factor in this equation. In this study we quantified the optimal percentage of compost in a green roof substrate for optimizing growth and yields for cucumbers (Cucumis sativus) and peppers (Capsicum annuum). The study was conducted on raised green roof platforms over a period of 19 weeks and compared six substrates containing increasing amounts of a commercial compost produced from municipal yard waste (0, 20, 40, 60, 80, and 100%) mixed with a heat-expanded shale and sand base. These treatments were also compared to a typical garden plot at ground level. Plant performance evaluations such as plant growth, chlorophyll fluorescence (Fv/Fm) as an indicator of plant stress, and fruit yields were used as an indicator for optimal substrate mixtures. Generally, the addition of 60 or 80% compost resulted in the greatest plant growth and fruit yields, although compost influenced growth and yield of peppers to a greater degree than cucumbers. In addition, the ground garden plots performed poorly which emphasizes the point that growing vegetables on a rooftop can be advantage because substrates can be engineered to maximize plant health, although the same could be done with raised beds in a garden plot. (C) 2015 Elsevier GmbH. All rights reserved
    corecore