Search results for: passive solar architecture

Authors: Sireetorn Kuharat, Anwar Beg

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In this study, multi-mode heat transfer characteristics of spacecraft solar collectors are investigated computationally. Two-dimensional steady-state incompressible laminar Newtonian viscous convection-radiative heat transfer in a rectangular solar collector geometry. The ANSYS FLUENT finite volume code (version 17.2) is employed to simulate the thermo-fluid characteristics. Several radiative transfer models are employed which are available in the ANSYS workbench, including the classical Rosseland flux model and the more elegant P1 flux model. Mesh-independence tests are conducted. Validation of the simulations is conducted with a computational Harlow-Welch MAC (Marker and Cell) finite difference method and excellent correlation. The influence of aspect ratio, Prandtl number (Pr), Rayleigh number (Ra) and radiative flux model on temperature, isotherms, velocity, the pressure is evaluated and visualized in color plots. Additionally, the local convective heat flux is computed and solutions are compared with the MAC solver for various buoyancy effects (e.g. Ra = 10,000,000) achieving excellent agreement. The P1 model is shown to better predict the actual influence of solar radiative flux on thermal fluid behavior compared with the limited Rosseland model. With increasing Rayleigh numbers the hot zone emanating from the base of the collector is found to penetrate deeper into the collector and rises symmetrically dividing into two vortex regions with very high buoyancy effect (Ra >100,000). With increasing Prandtl number (three gas cases are examined respectively hydrogen gas mixture, air and ammonia gas) there is also a progressive incursion of the hot zone at the solar collector base higher into the solar collector space and simultaneously a greater asymmetric behavior of the dual isothermal zones. With increasing aspect ratio (wider base relative to the height of the solar collector geometry) there is a greater thermal convection pattern around the whole geometry, higher temperatures and the elimination of the cold upper zone associated with lower aspect ratio.

Keywords: thermal convection, radiative heat transfer, solar collector, Rayleigh number

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Authors: Robson C. Santos, David D. Oliveira, Matheus M. Reis, Gerson G. Cunha, Marcos A. C. Moreira

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The project demonstrates the construction of a solar power generation, integrated inverter equipment to a "Grid-Tie" by converting direct current generated by solar panels, into alternating current, the same parameters of frequency and voltage concessionaire distribution network. The energy generated is quantified by smart metering module that transmits the information in specified periods of time to a microcontroller via GSM modem. The modem provides the measured data on the internet, using networks and cellular antennas. The monitoring, fault detection and maintenance are performed by a supervisory station. Employed board types, best inverter selection and studies about control equipment and devices have been described. The article covers and explores the global trend of implementing smart distribution electrical energy networks and the incentive to use solar renewable energy. There is the possibility of the excess energy produced by the system be purchased by the local power utility. This project was implemented in residences in the rural community of the municipality of Cabo Frio/RJ. Data could be seen through daily measurements during the month of November 2013.

Keywords: rural residence, supervisory, smart grid, solar energy

Procedia PDF Downloads 580

Authors: Elnur Abbasov

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Energy security and climate change comprise some of the most important concerns facing humankind today and probably in the future if they are not addressed appropriately. In order to stabilize the global climate, there is the need for the world to lessen its use of fossil energy, which requires enhancement of current energy efficiency as well as the development of novel energy sources, such as energy obtained from renewable sources. There is no doubt that the steady transition towards a solar-based economy is likely to result in the development of completely new sectors, behaviours, and jobs that are pro-environmental. Azerbaijan Republic as the largest nation state in the South Caucasus Region has the potential for using and developing the renewable sources of energy in order to support the environmental challenge resolution associated with the climate change, improving the environmental situation in the country. Solar PV comprises one of the direct usages of solar energy. In this paper, sustainable PV usage scenario in residential houses was introduced to reduce negative environmental effects of land use, water consumption, air pollution etc. It was recommended by an author that, PV systems can be part of function and design of residential building components: such as roofs, walls, windows.

Keywords: energy efficiency, environmentally friendly, photovoltaic engineering, sustainable energy usage scenario

Procedia PDF Downloads 239

Authors: Ekele T. Ochedi, Ahmad H. Taki, Birgit Painter

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The effect of the sun and its path on thermal comfort and energy consumption in residential buildings in tropical climates constitute a serious concern for designers, building owners, and users. Passive design approaches based on the sun and its path have been identified as a means of reducing energy consumption as well as enhancing thermal comfort in buildings worldwide. Hence, a thorough understanding regarding the sun path is key to achieving this. This is necessary due to energy need, poor energy supply, and distribution, energy poverty, and over-dependence on electric generators for power supply in Nigeria. These challenges call for a change in the approach to energy-related issues, especially in terms of buildings. The aim of this study is to explore the influence of building orientation, glazing and the use of shading devices on residential buildings in Nigeria. This is intended to provide data that will guide designers in the design of energy-efficient residential buildings. The paper used EnergyPlus to analyze a typical semi-detached residential building in Lokoja, Nigeria using hourly weather data for a period of 10 years. Building performance was studied as well as possible improvement regarding different orientations, glazing types and shading devices. The simulation results show some reductions in energy consumption in response to changes in building orientation, types of glazing and the use of shading devices. The results indicate 29.45% reduction in solar gains and 1.90% in annual operative temperature using natural ventilation only. This shows a huge potential to reduce energy consumption and improve people’s well-being through the use of proper building orientation, glazing and appropriate shading devices on building envelope. The study concludes that for a significant reduction in total energy consumption by residential buildings, the design should focus on multiple design options rather than concentrating on one or few building elements. Moreover, the investigation confirms that energy performance modeling can be used by building designers to take advantage of the sun and to evaluate various design options.

Keywords: energy consumption, energy-efficient buildings, glazing, thermal comfort, shading devices, solar gains

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Authors: Priya Ruban, Thirunavoukkarasu Manikkannan, Sakthivel Ramasamy

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Sulfide is one of the major pollutants of tannery effluent which is mainly generated during the process of unhairing. Recovery of Hydrogen green fuel from sulfide wastewater using photocatalysis is a ‘Cleaner Production Method’, since renewable solar energy is utilized. It has triple advantages of the generation of H2, waste minimization and odor or pollution control. Designing of safe and green photocatalysts and developing suitable solar photoreactor is important for promoting this technology to large-scale application. In this study, green photocatalyst i.e., spinach derived carbon dots (SCDs 5 wt % and 10 wt %)/TiO2 nanocomposite was synthesized for generation of H2 from sulfide wastewater using lab-scale solar photocatalytic reactor. The physical characterization of the synthesized solar light responsive nanocomposites were studied by using DRS UV-Vis, XRD, FTIR and FESEM analysis. The absorption edge of TiO2 nanoparticles is extended to visible region by the incorporation of SCDs, which was used for converting noxious pollutant sulfide into eco-friendly solar fuel H2. The SCDs (10 wt%)-TiO2 nanocomposite exhibits enhanced photocatalytic hydrogen production i.e. ~27 mL of H2 (180 min) from simulated sulfide wastewater under LED visible light irradiation which is higher as compared to SCDs. The enhancement in the photocatalytic generation of H2 is attributed to combining of SCDs which increased the charge mobility. This work may provide new insights to usage of naturally available and cheap materials to design novel nanocomposite as a visible light active photocatalyst for the generation of H2 from sulfide containing wastewater.

Keywords: carbon dots, hydrogen fuel, hydrogen sulfide, photocatalysis, sulfide wastewater

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Authors: G. Balaji, R. Balasundaraprabhu, S. Prasanna, M. D. Kannan, K. Sivakumaran, David Mcilroy

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Copper Zin tin sulphide (Cu2ZnSnS4 or CZTS) is found to be better alternative to Copper Indium gallium diselenide as absorber layers in thin film based solar cells due to the utilisation of earth-abundant materials in the midst of lower toxicity. In the present study, Cu2ZnSnS4 thin films were prepared on soda lime glass using (CuS, ZnS, SnS) targets and were deposited by three different stacking orders, using RF Magnetron sputtering. The substrate temperature was fixed at 300 °C during the depositions. CZTS thin films were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy and UV-Vis-NIR spectroscopy. All the samples exhibited X-ray peaks pertaining to (112) kesterite phase of CZTS, along with the presence of a predominant wurtzite CZTS phase. X-ray photoelectron spectroscopy revealed the presence of all the elements in all the samples. The change in stacking order clearly shows that it affects the structural and phase properties of the films. Relative atomic concentrations of Zn, Cu, Sn and S, which are determined by high-resolution XPS core level spectra integrated peak areas revealed that the CZTS films exhibit inhomogeneity in both stoichiometry and elemental composition. Raman spectroscopy studies on the film showed the presence of CZTS phase. The energy band gap of the CZTS thin films was found to be in the range of 1.5 eV to 1.6 eV. The films were then annealed at 450 °C for 5 hrs and it was found that the predominant nature of the X-ray peaks has transformed from Wurtzite to Kesterite phase which is highly desirable for absorber layers in thin film solar cells. The optimized CZTS layer was used as an absorber layer in thin film solar cells. ZnS and CdS were used as buffer layers which in turn prepared by Hot wall epitaxy technique. Gallium doped Zinc oxide was used as a transparent conducting oxide. The solar cell structure Glass/Mo/CZTS/CdS or ZnS/GZO has been fabricated, and solar cell parameters were measured.

Keywords: earth-abundant, Kesterite, RF sputtering, thin film solar cells

Procedia PDF Downloads 277

Authors: Kuang Sheng Liu, Yu Lin Shih*, Chun Ta Tzeng, Cheng Chen Chen

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Buildings in the 21st century are facing issues such as an extreme climate and low-carbon/energy-saving requirements. Many countries in the world are of the opinion that a building during its medium- and long-term life cycle is an energy-consuming entity. As for the use of architectural resources, including the United Nations-implemented "Global Green Policy" and "Sustainable building and construction initiative", all are working towards "zero-energy building" and "zero-carbon building" policies. Because of this, countries are cooperating with industry development using policies such as "mandatory design criteria", "green procurement policy" and "incentive grants and rebates programme". The results of this study can provide a reference for sustainable building renovation design criteria. Aimed at townhouses in Kaohsiung City, this study uses different levels of solar blocking depth to carry out evaluation of design and energy-saving renovation of the outer shell of existing buildings by using data collection and the selection of representative cases. Using building resources from a building information model (BIM), simulation and efficiency evaluation are carried out and proven with simulation estimation. This leads into the ECO-efficiency model (EEM) for the life cycle cost efficiency (LCCE) evalution. The buildings selected by this research sit in a north-south direction set with different solar blocking depths. The indoor air-conditioning consumption rates are compared. The current balcony depth of 1 metre as the simulated EUI value acts as a reference value of 100%. The solar blocking of the balcony is increased to 1.5, 2, 2.5 and 3 metres for a total of 5 different solar-blocking balcony depths, for comparison of the air-conditioning improvement efficacy. This research uses different solar-blocking balcony depths to carry out air-conditioning efficiency analysis. 1.5m saves 3.08%, 2m saves 6.74%, 2.5m saves 9.80% and 3m saves 12.72% from the air-conditioning EUI value. This shows that solar-blocking balconies have an efficiency-increasing potential for indoor air-conditioning.

Keywords: building information model, eco-efficiency model, energy-saving in the external shell, solar blocking depth.

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Authors: Vamsi G.

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Majority of the modern-day structures have less aesthetical value with minimum requirements set by foreign tribes. Numerous elements of traditional architecture can be incorporated into modern designs using appropriate principles to improve and enhance the functionality, aesthetics, and usability of any space. This paper reviews the diminishing ancient values of the traditional Islamic architecture. By introducing them into the modern-day structures like commercial, residential and recreational spaces in at least the Islamic states, the functionality of those spaces can be improved. For this, aspects like space planning, aesthetics, scale, hierarchy, value, and patterns are to be experimented with modern day structures. Case studies of few ancient Islamic architectural marvels are done to elaborate the whole. A brief analysis of materials and execution strategies are also a part of this paper. The analysis is formulated and is ready to design or redesign spaces using traditional Islamic principles and Elements of design to improve the quality of the architecture of modern day structures by studying the ancient Islamic architectural theories. For this, sources from the history and evolution of this architecture have been studied. Also, elements and principles of design from case studies of various mosques, forts, tombs, and palaces have been tabulated. All this data accumulated, will help revive the elements decorated by ancient principles in functional and aesthetical ways. By this, one of the most astonishing architectural styles can be conserved, reinstalled into modern day buildings and remembered.

Keywords: ancient architecture, architectural history, Islamic architecture, principles and elements

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Authors: A. Mourtzikou, D. Sygkridou, T. Georgakopoulos, G. Katsagounos, E. Stathatos

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Over 60% highly transparent quasi-solid-state dye-sensitized solar cells (DSSCs) with dimension of 50x50 cm² were fabricated via inkjet printing process using nanocomposite inks as raw materials and tested under outdoor illumination conditions. The cells were electrically characterized, and their possible application to the shell of greenhouses was also examined. The panel design was in Z-interconnection, where the working electrode was inkjet printed on one conductive glass and the counter electrode on a second glass in a sandwich configuration. Silver current collective fingers were printed on the glasses to make the internal electrical connections. In that case, the adjacent cells were connected in series via silver fingers and finally insulated using a UV curing resin to protect them from the corrosive (I^-/I₃^-) redox couple of the electrolyte.

Keywords: Dye-sensitized solar panels, inkjet printing, quasi-solid state electrolyte, semi-transparency, scale up

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Authors: Eko Adhi Setiawan, Duli Asih Siregar, Aiman Setiawan

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Solar energy is abundant in nature, particularly in the tropics which have peak sun hour that can reach 8 hours per day. In the fabrication process, Photovoltaic’s (PV) performance are tested in standard test conditions (STC). It specifies a module temperature of 25°C, an irradiance of 1000 W/ m² with an air mass 1.5 (AM1.5) spectrum and zero wind speed. Thus, the results of the performance testing of PV at STC conditions cannot fully represent the performance of PV in the tropics. For example Indonesia, which has a temperature of 20-40°C. In this paper, the effect of temperature on the choice of the 5 kW AC inverter topology on the PV system such as the Central Inverter, String Inverter and AC-Module specifically for the tropics will be discussed. The proper inverter topology can be determined by analysis of the effect of temperature and irradiation on the PV panel. The effect of temperature and irradiation will be represented in the characteristics of I-V and P-V curves. PV’s characteristics on high temperature would be analyzed using Solar panel modeling through MATLAB Simulink based on mathematical equations that form Solar panel’s characteristic curve. Based on PV simulation, it is known then that temperature coefficients of short circuit current (ISC), open circuit voltage (VOC), and maximum output power (PMAX) consecutively as high as 0.56%/oC, -0.31%/oC and -0.4%/oC. Those coefficients can be used to calculate PV’s electrical parameters such as ISC, VOC, and PMAX in certain earth’s surface’s certain point. Then, from the parameters, the utility of the 5 kW AC inverter system can be determined. As the result, for tropical area, string inverter topology has the highest utility rates with 98, 80 %. On the other hand, central inverter and AC-Module Topology has utility rates of 92.69 % and 87.7 % eventually.

Keywords: Photovoltaic, PV-Inverter Configuration, PV Modeling, Solar Panel Characteristics.

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Authors: Maryam Memarian, Mahmood Naghizadeh

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Deconstruction is an approach that is entirely incompatible with the traditional prevalent architecture. Considering the fact that this approach attempts to put architecture in sharp contrast with its opposite events and transpires with attending to the neglected and missing aspects of architecture and deconstructing its stable structures. It also recklessly proceeds beyond the existing frameworks and intends to create a different and more efficient prospect for space. The aim of deconstruction architecture is to satisfy both the prospective and retrospective visions as well as takes into account all tastes of the present in order to transcend time. Likewise, it ventures to fragment the facts and symbols of the past and extract new concepts from within their heart, which coincide with today’s circumstances. Since this approach is an attempt to surpass the limits of the prevalent architecture, it can be employed to design places in which creative events occur and imagination and ambition flourish. Thought-provoking artistic events can grow and mature in such places and be represented in the best way possible to all people. The concept of event proposed in the plan grows out of the interaction between space and creation. In addition to triggering surprise and high impressions, it is also considered as a bold journey into the suspended realms of the traditional conflicts in architecture such as architecture-landscape, interior-exterior, center-margin, product-process, and stability-instability. In this project, at first, through interpretive-historical research method and examining the inputs and data collection, recognition and organizing takes place. After evaluating the obtained data using deductive reasoning, the data is eventually interpreted. Given the fact that the research topic is in its infancy and there is not a similar case in Iran with limited number of corresponding instances across the world, the selected topic helps to shed lights on the unrevealed and neglected parts in architecture. Similarly, criticizing, investigating and comparing specific and highly prized cases in other countries with the project under study can serve as an introduction into this architecture style.

Keywords: anti-architecture, creativity, deconstruction, event

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Authors: Fung Sze Wai Veera, Peter W. Ferretto

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Gender functions as a principle in organizing society based on the cultural meanings given to males and females. It is an essential component in constructing the spatial reality, one that is in most cases in favor of men’s needs and disregards that of women’s. Similar to other minorities in China, men of the Dong community hold the primary position in policymaking, moral standards, social values, and, furthermore, the building of the physical environment. This study, therefore, aims to investigate the residential architecture of Dong through the lens of gender. Specifically, it examines how the patriarchal practice of Dong is manifested in terms of the spatial organization, the architectural feature, and the construction process of Dong houses in the southern dialect areas. While the residential architecture of Dong has been extensively researched, the role of gender culture in designing and constructing it deserves more research attention. Ultimately, the objective of this study is to challenge the notion of gender-inclusive design in the rural China context while opening up a cross-disciplinary discussion concerning Chinese minority architecture and gender studies.

Keywords: Dong minority residential architecture, gender study, built environment, male-dominated society, gender-inclusive design

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Authors: Razieh Teimouri

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Electrical modelling of Cu (In,Ga)Se₂ thin film solar cells is carried out with compositionally graded absorber and CdS buffer layer. Simulation results are compared with experimental data. Surface defect layers (SDL) are located in CdS/CIGS interface for improving open circuit voltage simulated structure through the analysis of the interface is investigated with or without this layer. When SDL removed, by optimizing the conduction band offset (CBO) position of the buffer/absorber layers with its recombination mechanisms and also shallow donor density in the CdS, the open circuit voltage increased significantly. As a result of simulation, excellent performance can be obtained when the conduction band of window layer positions higher by 0.2 eV than that of CIGS and shallow donor density in the CdS was found about 1×10¹⁸ (cm⁻³).

Keywords: CIGS solar cells, thin film, SCAPS, buffer layer, conduction band offset

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Authors: Gaurav Prabhudesai, Gaetan Brill

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The sun's energy source comes from a hydrogen-to-helium thermonuclear reaction, generating a temperature of about 5760 K on its outer layer. On account of this high temperature, energy is radiated by the sun, a part of which reaches the earth. This sunlight, even after losing part of its energy en-route to scattering and absorption, provides a time and space averaged solar flux of 174.7 W/m^2 striking the earth’s surface. According to one study, the solar energy striking earth’s surface in one and a half hour is more than the energy consumption that was recorded in the year 2001 from all sources combined. Thus, technology for extraction of solar energy holds much promise for solving energy crisis. Of the many technologies developed in this regard, Concentrating Solar Power (CSP) plants with central solar tower and receiver system are very impressive because of their capability to provide a renewable energy that can be stored in the form of heat. One design of central receiver towers is an open cavity where sunlight is concentrated into by using mirrors (also called heliostats). This concentrated solar flux produces high temperature inside the cavity which can be utilized in an energy conversion process. The amount of energy captured is reduced by losses occurring at the cavity through all three modes viz., radiation to the atmosphere, conduction to the adjoining structure and convection. This study investigates the natural convection losses to the environment from the receiver. Computational fluid dynamics were used to simulate the fluid flow and heat transfer of the receiver; since no analytical solution can be obtained and no empirical correlations exist for the given geometry. The results provide guide lines for predicting natural convection losses for hexagonal and circular shaped open cavities. Additionally, correlations are given for various inclination angles and aspect ratios. These results provide methods to minimize natural convection through careful design of receiver geometry and modification of the inclination angle, and aspect ratio of the cavity.

Keywords: concentrated solar power (CSP), central receivers, natural convection, CFD, open cavities

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Authors: Ahmed Aljudaya, Derek Ingham, Lin Ma, Kevin Hughes, Mohammed Pourkashanian

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Researchers, power companies, and state politicians have given concentrated solar power (CSP) much attention due to its capacity to generate large amounts of electricity whereas overcoming the intermittent nature of solar resources. The Linear Fresnel Reflector (LFR) is a well-known CSP technology type for being inexpensive, having a low land use factor, and suffering from low optical efficiency. The LFR was considered a cost-effective alternative option to the Parabolic Trough Collector (PTC) because of its simplistic design, and this often outweighs its lower efficiency. The LFR has been found to be a promising option for directly producing steam to a thermal cycle in order to generate low-cost electricity, but also it has been shown to be promising for indirect steam generation. The purpose of this important analysis is to compare the annual performance of the Direct Steam Generation (DSG) and Indirect Steam Generation (ISG) of LFR power plants using molten salt and other different Heat Transfer Fluids (HTF) to investigate their technical and economic effects. A 50 MWe solar-only system is examined as a case study for both steam production methods in extreme weather conditions. In addition, a parametric analysis is carried out to determine the optimal solar field size that provides the lowest Levelized Cost of Electricity (LCOE) while achieving the highest technical performance. As a result of optimizing the optimum solar field size, the solar multiple (SM) is found to be between 1.2 – 1.5 in order to achieve as low as 9 Cent/KWh for the direct steam generation of the linear Fresnel reflector. In addition, the power plant is capable of producing around 141 GWh annually and up to 36% of the capacity factor, whereas the ISG produces less energy at a higher cost. The optimization results show that the DSG’s performance overcomes the ISG in producing around 3% more annual energy, 2% lower LCOE, and 28% less capital cost.

Keywords: concentrated solar power, levelized cost of electricity, linear Fresnel reflectors, steam generation

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Authors: Radia Bagtache, Karima Boudjedien, Ahmed Malek Djaballah, Mohamed Trari

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The compounds with a spinel structure have received special attention because of their numerous applications in electronics, magnetism, catalysis, electrocatalysis, photocatalysis, etc. Among these oxides, CuCo₂O₄ was selected because of its optimal band gap, very close to the ideal value for solar devices, its low cost, and a potential candidate in the field of energy storage. Herein, we reported the junction Ag/CuCo₂O₄ (5/95 % wt.) prepared by co-precipitation, characterized physically and photo electrochemically. Moreover, its performance was evaluated for the oxidation of methyl orange (MO) under solar light. The X-ray diffraction exhibited narrow peaks ascribed to the spinel CuCo₂O₄ and Ag. The SEM analysis displayed grains with regular shapes. The band gap of CuCo₂O₄ (1.38 eV) was deducted from the diffuse reflectance, and this value decreased down to 1.15 eV due to the synergy effect in the junction. The current-potential (J-E) curve plotted in Na₂SO₄ electrolyte showed a medium hysteresis, characteristic of good chemical stability. The capacitance-2 – potential (C⁻² – E) graph displayed that the spinel behaves as a p-type semiconductor, a property supported by chrono-amperometry. The conduction band, located at 4.05 eV (-0.94 VNHE), was made up of Co³⁺: 3d orbital. The result showed a total discoloration of MO after 2 h of illumination under solar light.

Keywords: junction Ag/CuCo₂O₄, semiconductor, environment, sunlight, characterization, depollution

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Authors: Jossitt Williams Vargas Cruz, Aura Jazmín Pérez Ríos

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The variations of solar dynamics have become a relevant topic of study due to the effects of climate changes generated on the earth. One of the most disconcerting aspects is the variability that the sun has on the climate is the role played by sunspots (extra-atmospheric variable) in the modulation of the Cosmic Rays CR (extra-atmospheric variable). CRs influence the earth's climate by affecting cloud formation (atmospheric variable), and solar cycle influence is associated with the presence of solar storms, and the magnetic activity is greater, resulting in less CR entering the earth's atmosphere. The different methods of climate prediction in Colombia do not take into account the extra-atmospheric variables. Therefore, correlations between atmospheric and extra-atmospheric variables were studied in order to implement a Python code based on neural networks to make the prediction of the extra-atmospheric variable with the highest correlation.

Keywords: correlations, cosmic rays, sun, sunspots and variations.

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Authors: M. L. Akinyemi, T. J. Abodurin, A. O. Boyo, J. A. O. Olugbuyiro

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Organic dyes from Cola acuminata (C. acuminata), Lupinus arboreus (L. arboreus) and Bougainvillea spectabilis (B. spectabilis) leaves and their mixtures were used as sensitizers to manufacture dye-sensitized solar cells (DSSC). Photoelectric measurements of C. acuminata showed a short circuit current (J_sc) of 0.027 mA/ cm², 0.026 mA/ cm² and 0.018 mA/ cm² with a mixture of mercury chloride and iodine (Hgcl₂ + I); potassium bromide and iodine (KBr + I); and potassium chloride and iodine (KCl + I) respectively. The open circuit voltage (V_oc) was 24 mV, 25 mV and 20 mV for the three dyes respectively. L. arboreus had J_sc of 0.034 mA/ cm², 0.021 mA/ cm² and 0.013 mA/ cm²; and corresponding V_oc of 28 mV, 14.2 mV and 15 mV for the three electrolytes respectively. B. spectabilis recorded J_sc 0.023 mA/ cm², 0.026 mA/ cm² and 0.015 mA/ cm²; and corresponding V_oc values of 6.2 mV, 14.3 mV and 4.0 mV for the three electrolytes respectively. It was observed that the fill factor (FF) was 0.140 for C. acuminata, 0.3198 for L. arboreus and 0.1138 for B. spectabilis. Internal conversions of 0.096%, 0.056% and 0.063% were recorded for three dyes when combined with (KBr + I) electrolyte. The internal efficiency of C. acuminata DSSC was highest in value.

Keywords: dye-sensitized solar cells, organic dye, C. acuminate, L. arboreus, B. spectabilis, dye mixture

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Authors: Xiaoyan Wang, Zhongde Wang

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The issue of climate change, which originated in the middle of the twentieth century, has become a focus of international political, academic, and non-governmental organizations and public attention. In order to address the problems caused by climate change, the Chinese government has proposed a dual-carbon target and taken some national measures, such as ecological priority and green low-carbon development. These goals and measures are highly aligned with the values of the landscape architecture industry. This is an opportunity for the architectural discipline and the landscape architecture industry, so it is very necessary to summarize and analyze the hotspots related to climate change in the field of building science in China, which can assist the landscape architecture industry and related organizations in formulating more rational professional goals and taking actions that contribute to the betterment of societal, environmental development. Through the study, it is found as follows: firstly, after 20 years of rapid development, the research on climate change in the major architectural disciplines has shown a trend of diversification of research perspectives, interdisciplinary cross-cutting, and broadening of content; secondly, the research contents of landscape architecture focuses on the strategies to adapt to climate change, such as selection of urban tree species, the urban green infrastructure space layout, and the resilient city. Finally, in the future, climate change-based landscape architecture research will make the content system more diversified, but at the same time, it is still necessary to further deepen the research on quantitative methodology and construct scale systematic planning and design methods.

Keywords: climate change, landscape architecture, knowledge mapping, cites-pace

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Authors: Marcela Dávalos López

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In Mexico, the distribution of hygienistarchitecture during the 20th century had different rhythms. The culmination of the urban hygiene system (from sewers to showers, passing through garbage collection) forced neighbors and citizens to participate in the common welfare. This turned the urban references and dissociated the ways of living and led to comfort and health. However, the contrast between two Mexicancities, Cuernavaca and Mexico City shows us very different cultural practices regarding the use of hygienicarchitectures: in the first, thenature of its deepravines marked the destiny of residential architecture, while in Mexico City, state participation alteredthelandscape and homogenized the architectural models of domestic and intímate spaces.

Keywords: Cultural Practices, Dissociated Ways To Comfort, Hygiene Architecture , Mexico

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Authors: Cengiz Tavşan, Niloufar Akbarzadeh

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Architecture in Iran has a continuous history from at least 5000 BC to the present, and numerous Iranian pre-Islamic elements have contributed significantly to the formation of Islamic art. At first, decoration was limited to small objects and containers and then progressed in the art of plaster and brickwork. They later applied in architecture as well. The art of gypsum and brickwork, which was prevalent in the form of motifs (animals and plants) in pre-Islam, was used in the aftermath of Islam with the art of calligraphy in decorations. The splendor and beauty of Iranian architecture, especially during the Islamic era, are related to decoration and design. After the invasion of Iran by the Arabs and the introduction of Islam to Iran, the arrival of the Iranian classical architecture significantly changed, and we saw the Arabic calligraphy decoration of the mosques in Iran. The principles of aesthetics in the art of calligraphy in Iran are based precisely on the principles of the beauty of ancient Iranian and Islamic art. On the other hand, after Islam, calligraphy was one of the most important sources of Islamic art in Islam and one of the important features of Islamic culture. First, the calligraphy had no cultural meaning and was only for decoration and beautification, it had the same meaning only in the inscriptions; however, over time, it became meaningful. This article provides a summary of the history of calligraphy in the mosques (from the entrance to Islam until the Safavid period), which cannot ignore the role of the calligraphy in their decorative ideas; and also, the important role that decorative elements play in creating a public space in terms of social and aesthetic performance. This study was conducted using library studies and field studies. The purpose of this study is to show the characteristics of architecture and art of decorations in Iran, especially in the mosque's architecture, which reaches the pinnacle of progress. We will see that religious beliefs and artistic practices are merging and trying to bring a single concept.

Keywords: Islamic art, Islamic architecture, decorations in Iranian mosques, calligraphy

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Authors: Emre Ünal, Hasan Başaran

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In this study, starting with a predetermined Lunar free-return trajectory, an analysis of major near-Earth perturbations is carried out. Referencing to historical Apollo-13 flight, changes in the mission’s resultant perimoon and perigee altitudes with each perturbative effect are evaluated. The perturbations that were considered are Earth oblateness effects, up to the 6^th order, atmospheric drag, third body perturbations consisting of solar and planetary effects and solar radiation pressure effects. It is found that for a Moon mission, most of the main perturbative effects spoil the trajectory significantly while some came out to be negligible. It is seen that for apparent future request of constructing low cost, reliable and safe trajectories to the Moon, most of the orbital perturbations are crucial.

Keywords: Apollo-13 trajectory, atmospheric drag, lunar trajectories, oblateness effect, perturbative effects, solar radiation pressure, third body perturbations

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Authors: Dimitra Sygkridou, Andreas Rapsomanikis, Elias Stathatos, Polycarpos Falaras, Evangelos Vitoratos

Abstract:

At the present work highly transparent strip type quasi-solid state dye-sensitized solar cells (DSSCs) were fabricated through inkjet printing using nanocomposite TiO2 inks as raw materials and tested under outdoor illumination conditions. The cells, which can be considered as the structural units of large area modules, were fully characterized electrically and electrochemically and after the evaluation of the received results a large area DSSC module was manufactured. The module design was a sandwich Z-interconnection where the working electrode is deposited on one conductive glass and the counter electrode on a second glass. Silver current collective fingers were printed on the conductive glasses to make the internal electrical connections and the adjacent cells were connected in series and finally insulated using a UV curing resin to protect them from the corrosive (I-/I3-) redox couple of the electrolyte. Finally, outdoor tests were carried out to the fabricated dye-sensitized solar module and its performance data were collected and assessed.

Keywords: dye-sensitized solar devices, inkjet printing, quasi-solid state electrolyte, transparency, up-scaling

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Authors: Yasaman Tabari-Saadi, Kaiwen Sun, Jialiang Huang, Martin Green, Xiaojing Hao

Abstract:

Optical and electrical properties of p-type AgBiS₂ absorber material have been improved by copper doping on silver sites. X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis suggest that complete solid solutions of Ag₁₋ₓCuₓBiS₂ thin film have been formed. The carrier concentration of pure AgBiS₂ thin film deposited by the chemical process is 4.5*E+14 cm⁻³, and copper doping leads to the improved carrier concentration despite the semiconductor AgBiS₂ remains p-type semiconductor. Copper doping directly changed the absorption coefficient and increased the optical band gap (~1.5eV), which makes it a promising absorber for thin-film solar cell applications.

Keywords: copper doped, AgBiS₂, thin-film solar cell, carrier concentration, p-type semiconductor

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Authors: Francois Defay, Martim Calao, Jean Francois Dassieu, Laurent Salvetat

Abstract:

Electrical vehicles are a solution for reducing the pollution using green energy. The shell Eco-Marathon provides rules in order to minimize the battery use for the race. The use of solar panel combined with efficient motor control and race strategy allow driving a 60kg vehicle with one pilot using only the solar energy in the best case. This paper presents a complete modelization of a solar vehicle used for the shell eco-marathon. This project called Helios is cooperation between non-graduated students, academic institutes, and industrials. The prototype is an ultra-energy-efficient vehicle based on one-meter square solar panel and an own-made brushless controller to optimize the electrical part. The vehicle is equipped with sensors and embedded system to provide all the data in real time in order to evaluate the best strategy for the course. A complete modelization with Matlab/Simulink is used to test the optimal strategy to increase the global endurance. Experimental results are presented to validate the different parts of the model: mechanical, aerodynamics, electrical, solar panel. The major finding of this study is to provide solutions to identify the model parameters (Rolling Resistance Coefficient, drag coefficient, motor torque coefficient, etc.) by means of experimental results combined with identification techniques. One time the coefficients are validated, the strategy to optimize the consumption and the average speed can be tested first in simulation before to be implanted for the race. The paper describes all the simulation and experimental parts and provides results in order to optimize the global efficiency of the vehicle. This works have been started four years ago and evolved many students for the experimental and theoretical parts and allow to increase the knowledge on electrical self-efficient vehicle.

Keywords: electrical vehicle, endurance, optimization, shell eco-marathon

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Authors: Kumar Sambhav Pandey, Anamika Singh

Abstract:

The continuous researches in the field of computer architecture basically aims at accelerating the computational speed and to gain enhanced performance. In this era, the superscalar, sub-scalar concept has not gained enough attention for improving the computation performance. In this paper, we have presented a sub-scalar approach to utilize the parallelism present with in the data while processing. The main idea is to split the data into individual smaller entities and these entities are processed with a defined known set of instructions. This sub-scalar approach to the MIPS architecture can bring out significant improvement in the computational speedup. MIPS-I is the basic design taken in consideration for the development of sub-scalar MIPS64 for increasing the instruction level parallelism (ILP) and resource utilization.

Keywords: dataword, MIPS, processor, sub-scalar

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Authors: Alfons Aziz Asaad Hozain

Abstract:

The goal of sustainable architecture is to design buildings that have the least negative impact on the environment and provide better conditions for people. What forms of development enhance the area? This question was asked at the Center for the Study of Spatial Development and Building Forms in Cambridge in the late 1960s. This has resulted in many influential articles that have had a profound impact on the practice of urban planning. This article focuses on the sustainability outcomes caused by the climatic conditions of traditional Iranian architecture in hot and dry regions. Since people spend a lot of time at home, it is very important that these homes meet their physical and spiritual needs as well as the cultural and religious aspects of their lifestyle. In a country as large as Iran with different climates, traditional builders have put forward a number of logical solutions to ensure human comfort. With these solutions, the environmental problems of the have long been solved. Taking into account the experiences of traditional architecture in Iran's hot and dry climate, sustainable architecture can be achieved.

Keywords: sustainable development, human rights, the right to development, the human rights-based approach to development, environmental rights, economic development, social sustainability human rights protection, human rights violations, workers’ rights, justice, security

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Authors: Tahsin Shameem, Chowdhury Sadman Jahan, Mohammad Alam

Abstract:

Interest about Net Zero Energy Buildings have gained traction in recent years following the need to sustain energy consumption with generations on site and to reduce dependence on grid supplied energy from large plants using fossil fuel. With this end in view, building integrated photovoltaics are being studied attempting to utilize all exterior facades of a building to generate power. In this paper, we have looked at the physical parameters defining a dye sensitized solar cell (DSSC) and discussed their impact on energy harvest. Following our discussion and experimental data obtained from literature, we have attempted to optimize these physical parameters accordingly so as to allow maximum light absorption for a given active layer thickness. We then modified a planer DSSC design with our optimized properties to allow adequate light transmission which demonstrated a high fill factor and an External Quantum Efficiency (EQE) of greater than 9% by computer aided design and simulation. In conclusion, a DSSC based solar window with such high output values even after such high light transmission through it definitely flags a promising future for this technology and our work elicits the need for further study and practical experimentation.

Keywords: net zero energy building, integrated photovoltaics, dye sensitized solar cell, fill factor, External Quantum Efficiency

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Authors: Talha Ali Khan

Abstract:

Discovering different energy resources to full fill the world growing demand is now one of the society’s bigger challenge for the next half-century. The main task is to convert the sun radiation into electricity via photovoltaic solar cells which is suddenly decreasing $/watt of delivered solar electricity. Therefore, in this context, the sun trackers are those devices that can be used to ameliorate efficiency. In this paper, a variety of the sun tracking systems are evaluated and their merits and demerits are highlighted. The most adept and proficient sun-tracking devices are polar axis and azimuth-elevation types.

Keywords: dual axis, fixed axis, sun tracker, MPPT

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Authors: Juan Sebastián Rivera Soriano, Rosa Urbano Gutiérrez

Abstract:

The Shodan House and the Sarabhai House (Ahmedabad, India, 1954 and 1955, respectively) are considered some of the most important works of Le Corbusier produced in the last stage of his career. There are some academic publications that study the compositional and formal aspects of their architectural design, but there is no in-depth investigation into how the climatic conditions of this region were a determining factor in the design decisions implemented in these projects. This paper argues that Le Corbusier developed a specific architectural design strategy for these buildings based on scientific research on climate in the Indian context. This new language was informed by a pioneering study and interpretation of climatic data as a design methodology that would even involve the development of new design tools. This study investigated whether their use of climatic data meets values and levels of accuracy obtained with contemporary instruments and tools, such as Energy Plus weather data files and Climate Consultant. It also intended to find out if Le Corbusier's office’s intentions and decisions were indeed appropriate and efficient for those climate conditions by assessing these projects using BIM models and energy performance simulations from Design Builder. Accurate models were built using original historical data through archival research. The outcome is to provide a new understanding of the environment of these houses through the combination of modern building science and architectural history. The results confirm that in these houses, it was achieved a model of low energy consumption. This paper contributes new evidence not only on exemplary modern architecture concerned with environmental performance but also on how it developed progressive thinking in this direction.

Keywords: bioclimatic architecture, Le Corbusier, Shodan, Sarabhai Houses

Procedia PDF Downloads 57