Clay Panels Research Articles

Plantlets directly developed from secondary phyllodes of Sargassum siliquosum J. Agardh: Implication for seedling production during the off-reproductive season

Development of plantlets was observed from excised secondary phyllodes of Sargassum siliquosum within a two-week period under culture conditions of 20 °C ambient temperature, 26 °C seawater temperature, 200 μmol photons m−2 s−1 light intensity, 12:12 L:D photoperiod, pH 8, and 35 psu salinity. The plantlets developed along the entire margin and both surfaces of the phyllode. Initially, small protuberances of 57.0–76.21 μm diameter were observed to develop on the surfaces that ultimately developed into plantlets with rhizoids however, no protuberances were observed along the margin of the phyllodes. These plantlets were separately cultured under similar environmental conditions except at 40 μmol photons m−2 s−1 light intensity on different substrata viz. clay panels, sponge, and cotton-mixed nylon. Among these substrata, the maximum attachment of plantlets was observed on sponge substrate followed by clay panels, and least on cotton-mixed nylon. Approximately 1427 plantlets developed on a single phyllode. These plantlets could be used as a source of planting materials during the off-reproductive season of Sargassum.

Study of thermal and mechanical properties of typha leaf - clay panels

Study of thermal and mechanical properties of typha leaf - clay panels

Behaviour of sand-filled plastic bottled clay panels for sustainable homes

Adequate shelter is a basic necessity for human existence and mankind has continuously improved the quality of shelter. It is estimated that about 1.6 billion people still lack adequate housing. There is a cogent need for developing new methods of delivering housing that can be accessible to low-income communities who have little or no access to finances. Plastic bottles have been suggested as a candidate material for constructing low-cost, environmentally friendly homes in developing countries. Although some research on the use of plastic bottles for housing was found, the existing literature shows considerable discrepancies in the strength of plastic bottles and bottled cubes. Furthermore, the literature is limited to cement cubes and no research has been carried out using locally sustainable materials such as soils. As part of the ‘Bottle House’ project for developing low-cost sustainable homes in Nigeria, this paper seeks to fill this gap by reporting the results of two series of experimental work carried out at the University of Plymouth. A total of eight-four 500 ml PET bottles and twelve wall and floor panels with and without sand-filled plastic bottles were prepared and tested to investigate their strength and failure behaviour. The test results have shown that in-filled sands made a significant contribution to the strength of the bottles and the bottles tested vertically resisted better than those tested horizontally. They have also shown that the panels with sand-filled bottles have about a quarter of the strength of the daub only panels due to a lack of cohesion between bottles and daub, but they are found to be more ductile than the latter.

Reduction of terms of demolition works of fully assembled residential buildings in Moscow

As of the end of 2017, in Moscow, there are 286 mapped five-story fully-assembled residential buildings of K-7, II-32, II-35, 1605-AM, 1MG-300 series with total area of 1046,7 thousand square meters. They were built at the beginning of the era of mass construction, in 1959 - 1962 years, and were distinguished by thin outer walls of lightweight ribbed expanded clay panels with unstable thermal protection properties. The technologies used in the construction of such buildings do not allow reconstructing them. Nowadays, the task of demolition of the neighborhood of five-storey houses in Moscow with the maximum possible reduction in terms of production of works and the maximum quality of work is very important. It is also necessary to ensure safe work and compliance with all sanitary standards. The order of execution of the works has a mathematical solution method. It identifies issues that arise in the alternating sections performing the process of demolition.

The role of areal heat capacity and decrement factor in case of hyper insulated buildings: An experimental study

Extensive simulation-based researches have highlighted the importance of placing a massive layer in the inner side of hyper insulated CLT buildings in the interest of optimize their thermal performance on an annual basis. The purpose of the present research is to experimentally evaluate the thermal responsiveness of multi layered and highly insulated CLT building envelopes characterized by different combination of two dynamic parameters, namely the internal areal heat capacity κ1 and the decrement factor f.An on-site monitoring campaign was extensively performed, during summer and winter seasons, on an unoccupied and windowless test room in Central Italy. Four internal linings were simultaneously tested on the south facing wall: plasterboard (as a baseline reference), two dry clay panels with different thickness and a combination of brick and an additional internal insulation layer. Over the year, the indoor microclimate was exposed to three different occupancy/solar gains profiles, identified with Test 1–3 and supplied to the room by three electric radiators.During Test 1 and Test 2 (summer and autumn, respectively), the results have shown the limits of the adoption of lightweight and hyper-insulated external walls with high internal areal heat capacity and very low decrement factor in the Mediterranean area. In fact, such typology exhibits the highest surface temperatures, with daily maximum around 28 °C and nocturnal minimum approximately 1.5 °C lower. Moreover, increasing the thermal resistance of a wall by adding an insulated lining partially inhibits the proper storage ability on the inner side, causing the release of more heat inside the test room.Conversely in winter (Test 3), such configuration was found to have a positive response in terms of stored heat quota, with respect to the released one.The solution that guaranteed the best thermal performance on annual basis under different indoor boundary conditions was the wall envelope characterized by average inertial properties, notably κ1 equal to 33 kJ/(m2K) and a decrement factor of 0.072.

Natural Stabilized Earth Panels versus Conventional Façade Systems. Economic and Environmental Impact Assessment

More effective construction technologies are needed nowadays in order to reduce construction energy consumption during the life-cycle of buildings. Besides which, it is necessary to consider the economic feasibility and associated costs within the framework of these alternative technologies so as to favouring their practical implementation in the construction sector. In this sense, this paper presents an economic and environmental comparison of a new non-bearing façade construction solution based on the extruded unfired stabilized clay panels as opposed to three traditional solutions with similar physical, thermal, and aesthetic characteristics in terms of the exterior cladding. The proposed panels are a sandwich type configuration with an intermediate insulating material and two exterior pieces manufactured by extrusion with raw earth stabilized with alginate and animal wool fibers. In this paper, details of the constructive technology of the system are provided. From the results obtained, it is possible to conclude that the solution is a valid alternative from the environmental point of view, considerably reducing the Global Warming Potential and the Cumulative Energy Demand. And although the environmental improvement of the system can be considered the primary objective of this investigation, on the other hand, once executed, it will also be a competitive constructive technology from the perspective of the system’s final costs.

REMOVING FLUORIDE FROM A HOT SPRING USING AN ELECTROLYSIS SYSTEM

A high concentration of fluoride in the wastewater from hot springs is an environmental issue in Japan, since some of the wastewater exceeds the national minimum effluent standards of 8 mg/l. However, an effective treatment for fluoride removal has not yet been developed. Accordingly, the temporal effluent standards of 15mg/l - 50 mg/l have, so far, been applied to the wastewater from hot springs.In this study, an electrolysis system consisting of an anode bath and a cathode bath separated by a diaphragm made of a clay panel was tested for the removal of fluoride. In an electrolysis system, fluoride is removed by co-precipitation with magnesium hydroxide formed in a cathode bath under a high pH condition. As a pretreatment of wastewater, 100 mg/l of magnesium was added to water from Gero hot spring, Gifu, Japan, to enhance the formation of the precipitation of magnesium hydroxide, since water from Gero hot spring contains less than 1 mg/l of magnesium. Water from Gero hot spring to which 100 mg/l of magnesium had been added was treated by an electrolysis system with a flow rate of 10 l/day and a current of 120 mA. The electrolysis system reduced the fluoride concentration from 16.6 mg/l to 6.4 mg/l, which meets the national minimum effluent standards of 8 mg/l.

Super-insulated wooden envelopes in Mediterranean climate: Summer overheating, thermal comfort optimization, environmental impact on an Italian case study

The aim of the study is to verify the actual performance of a super-insulated wooden envelope in a residential building located in a hot dry summer temperate climate and to optimize its thermal behavior favoring a dynamic interaction with the indoor environment.The method involved an integrated strategy between monitoring and calibrated simulations on experimental data and the simultaneous analysis of several aspects such as energy performance (EnergyPlus software), comfort (dynamic analysis with Fanger’s PMV comfort model) and environmental-economic sustainability (LCA analysis with SimaPro software). Parametric analyses were carried out to generalize the results to various usage patterns of plants and passive cooling techniques and to several climate zones.The study highlighted the presence of overheating phenomena and demonstrated that this problem can be solved or reduced through the adoption of appropriate passive strategies, such as massive inner linings combined with natural or hybrid ventilation.Appropriate values of internal areal heat capacity and decrement factor will configure comfortable and energy efficient solutions.In temperate climates the optimal solution, namely the adoption of a 12cm thick solid brick (or double dry clay panel) and natural ventilation, reduces the discomfort levels of 30–50%. In hottest periods of extreme climates the best solution, namely CMV+free-cooling combined with internal lightweight plaster, only slightly reduces the overheating with a 6% reduction of discomfort.