Electrochemical conversion of switchgrass and poplar in molten carbonate direct carbon fuel cell

One way of sustaining fuel cell technology is using renewable and sustainable energy means provided by biomass. This article explores switchgrass and poplar in a molten carbonate electrolyte direct carbon fuel cell. It investigates their electrochemical conversions and provides results of power density, current density, open circuit voltage (OCV) and other parameters. The biomasses were pyrolysed at 800°C to produce carbon fuels. Biomass carbon fuels were mixed with molten carbonate and subjected to different operating conditions (600–800°C) in the fuel cell. The electrochemical performances of the poplar fuel were better than those experienced with switchgrass fuel. At 800°C the OCV of poplar fuel (1.08?V) has higher output than switchgrass (0.87?V). The peak power density recorded for poplar fuel was 23.91?mW/cm² while switchgrass fuel was lower at 21.60?mW/cm². Poplar fuel (81.53?mA/cm²) gave a maximum current density with switchgrass fuel lower at 74.00?mA/cm².     

Performance of Paracoccus homiensis DRR-3 in microbial fuel cell with membranes

This study focuses on the bioelectricity production of Paracoccus homiensis strain DRR-3, a Gram-negative bacterium with Nafion117 and polymer membranes. Among the various electrodes used, carbon paper showed a higher production of 790?mV and 0.13?mA with Nafion 117 membrane and 290?mV and 0.10?mA with salt bridge as a proton exchanger. The scanning electron micrograph of the biofilm attached to the anode revealed the presence of P. homiensis. A major highlight in this study is to reveal the efficiency of the two membranes made of conducting polymers (polyvindylene difluoride [PVDF] and polycarbazole [PCZ]) in the proton transfer. Electrochemical impedance spectroscopy was used to study the anode resistance, total resistance of the microbial fuel cell and to recognise the membrane which facilitates the efficient proton transfer. The PVDF membrane showed a better performance of bioelectricity generation when compared to Nafion and PCZ membrane with a low R_ct value of 45.05?Ω and R_s of 23.61?Ω.     

Thermo-environmental performance analysis of irreversible solid oxide fuel cell – Stirling heat engine

A hybrid, irreversible solid oxide fuel cell – Stirling heat engine system is taken into account. Thermoenvironmental criterion approach, which enables to evaluate environmental impact of any thermal cycle, is applied to the considered system for the first time. Power density, exergy density, thermoenvironmental function density, energy and exergy efficiencies are considered. Results are presented and discussed to determine optimum operating conditions. Some important results for the hybrid system are ordered: maximum power density is 7489.92 (A?m^?2), maximum energy and exergy efficiencies are 0.800 and 0.887, respectively, and finally, thermoenvironmental function density is 0.0276 (W?mpts^?1?m^?2).     

Experimental investigation of varying the fuel injection pressure in a direct injection diesel engine fuelled with methyl ester of neem oil

Being a fuel of different origin, the standard design parameters of a diesel engine may not be suitable for methyl ester of neem oil (MENO). So the engine parameters need to be optimised to suit the specific fuel properties. This experimental investigation is to find the effects of one of the engine parameters, that is, fuel injection pressure (FIP) jointly on the performance with regard to brake thermal efficiency (BTE), brake-specific energy consumption (BSEC), and emissions of carbon monoxide, carbon dioxide, hydrocarbon, nitrogen oxides, and smoke intensity with neat MENO as fuel. Comparison of performance and emission test were done for different values of IP to find the best possible IP for the optimum performance and emission. The optimum FIP was found to be 240?bar. It is found that the increase in IP increases the BTE and reduces the BSEC while having lower emissions.     

Modelling and simulation of single- and triple-junction solar cells using MATLAB/SIMULINK

The main objective of this paper is to determine the single- and triple-junction solar cells’ I–V and P–V curves, define maximum voltage, current, and power. The paper demonstrates and analyses different environmental conditions that affect the solar cells, such as temperature and irradiance. The performance of single- and triple-junction solar cells is evaluated by analysing the fill factor. In this work, the analysis of single- and triple-junction solar cells is carried out through software simulation. Different conditions demonstrated to observe the results of this variation in both single- and triple-junction cells, such as observing the solar cell behaviour under variation of temperature between 15°C (288.315?K) and 45°C (318.15?K) for the single-junction cell and between 268.15?K (?5°C) and 348.15?K (75°C) for the triple-junction cell to observe the effect of temperature on open circuit voltage, the variation of different levels of irradiance to observe its effect on open circuit voltage and current density on both cell types, and cell performance evaluation using the fill factor concept. Practical results used in this paper are obtained from Clyde Space’s laboratories. Tests of Clyde Space were done using halide lamps to simulate the irradiation conditions with irradiance of half sun which is equivalent to 0.05?W?cm^?2. The operation was done under temperature of 40°C which is equivalent to 313.15?K.     

Fire Performance of Phase Change Material Enhanced Plasterboard

Sustainable construction materials are increasingly being used to reduce the carbon footprint of modern buildings. These materials have the potential to change the fire dynamics of compartments by altering the compartment energy balance however there is little quantitative understanding of how these materials behave in the event of a real fire. The changes in fire dynamics may be due to increased fuel load in a compartment, reduced time to failure or promotion of flame spread. The objective of this research is to quantify how Phase Change Materials (PCMs) perform in realistic fire scenarios. It was found that a plasterboard product containing microencapsulated PCMs will behave similarly to a charring solid and have the potential to contribute significant fuel to a compartment fire but that they maintain integrity for the duration of flaming period. The critical heat flux for this product was determined in the cone calorimeter to be 17.5 ± 2.5 kW m^?2, the peak heat release rate and mass loss rate ranged from 60.2 kW m^?2 to 107 kW m^?2 and 1.88 g s^?1 m^?2 to 8.47 g s^?1 m^?2 respectively for exposures between 20 kW m^?2 and 70 kW m^?2. Sample orientation was found to increase the peak heat release rate by up to 25%, whilst having little to no effect on the mass loss rate. These parameters, in addition to the in-depth temperature evolution and ignition properties, can be used as design criteria for balancing energy savings with quantified fire performance.     

The removal of colour from effluent using various adsorbents—III. Silica: Rate processes

The rate of adsorption of Astrazone Blue, a basic dye, on Sorbsil Silica has been studied. The parameters studied include particle size, initial dye concentration, agitation and dye solution temperature. The rate controlling step is mainly intraparticle diffusion, although a small boundary layer resistance is experienced. The activation energy for the adsorption of Astrazone Blue on silica is 13.2 ± 0.6 kJ kg^?1. The diffusion coefficients vary from 9 × 10^?9 cm² s^?1 at 20°C to 10 × 10^?8 cm² s^?1 at 82°C.     

The short-term and creep mechanical behaviour of clayey soil-geocomposite drainage layer interfaces subjected to environmental loadings

In this paper, to investigate the impact of environmental loadings on the short-term and creep mechanical characteristics of different types of clayey soil-Geocomposite Drainage Layers (GDL) interfaces, a series of rapid loading and creep shear tests were conducted on Mercia Mudstone Clay-GDL interfaces and Kaolin Clay-GDL interfaces subjected to drying-wetting cycles, thermal cycles and elevated temperature, etc, using a bespoke temperature and stress-controlled large direct shear apparatus. The experimental results indicate that, compared with the original specimens, the interfaces subjected to drying-wetting cycles, thermal cycles and elevated temperature, have lower peak shear strength and creep shear resistance. For example, under 25 kPa normal stress, the peak shear strength of original Mercia Mudstone Clay-GDL interfaces and Kaolin Clay-GDL interfaces falls by 11.91% and 10.11%, respectively, when subjected to 1 drying-wetting cycle. This can be ascribed to the weakening of interlocking effects and skin friction between soil and GDL caused by the softening of drainage core and geotextile fibres of GDL. The peak shear strength of clayey soil-GDL interfaces subjected to one drying-wetting cycle is lower than that subjected to one thermal cycle because of the reduction in the peak shear strength of clayey soil above GDL during drying-wetting cycles. The impact of drying alone on the decrease in the peak shear strength of clayey soil-GDL interfaces during drying cycles with heating is small, and the main influence factor is the elevated temperature.     

Modified stress and temperature-controlled direct shear apparatus on soil-geosynthetics interfaces

In this paper, a bespoke stress and temperature controlled direct shear apparatus to test soil-geosynthetics interfaces is introduced. By adopting the apparatus, a series of ‘rapid loading’ shear tests and creep tests were conducted on the Clay – Geosynthetic Drainage layer (GDL) interfaces to assess the functionality of the apparatus. The experimental results indicate that, the modified apparatus can allow the shear deformation behaviour of soil-geosynthetics interfaces under environmental stress during thermal and drying-wetting cycles to be investigated, with a reliable performance. The resistance of Clay-GDL interfaces to shear deformation under the rapid loading of shear stress decreases after drying-wetting cycle and at elevated temperature. In the creep tests, the interfaces subjected to drying-wetting cycles and thermal cycles fail under a lower shear stress level than that of the interfaces without experiencing drying-wetting cycles and thermal cycles, respectively. The impacts of drying cycles on the horizontal displacement is significantly larger than that of wetting cycles. The first drying cycle has the largest impacts on the horizontal displacement than those of the following drying cycles. The impacts of drying alone on the horizontal displacement of Clay-GDL interfaces during drying cycles are small, and the main influence factor is the elevated temperature.     

Performance assessment of empirical models for prediction of daily and monthly average global solar radiation: the case study of Ibadan,Nigeria

In this study, the performance assessment of empirical models for modelling global solar radiation in Ibadan is presented. The empirical models are derived from the three basic models: Angstrom–Prescott model, Garcia model and Hargreaves–Sammani model. The data used in the analysis consist of daily average global solar radiation, daily average sunshine hours, daily average maximum temperature and daily average minimum temperature collected over a period of nine years (2000–2008). Regression constants are determined for each of the model for each months of the year. The study reveals that Garcia Quadratic model puts up the best overall performance. The model can predict the daily average global solar irradiation with Mean Absolute Error of 1.86?MJ?m^?2?day^?1, Root Mean Square Error of 2.7?MJ?m^?2?day^?1, Mean Absolute Percentage Error 9.34% and Coefficient of Determination (R²) of 0.68.     

Carbon sequestration potential of spotted gum (Corymbia citriodora subspecies Variegata) in South East Queensland,Australia

The objectives of this study were to determine the carbon sequestration potential of spotted gum forest plantation in the South East Queensland region and to determine the suitability of the whole area to carbon sequestration endeavour. This information is indispensable to stakeholders when considering land use options particularly carbon sequestration. A process-based model and geographic information system were employed in the process. The site has a potential biomass production of 1422–2329?ton?ha^?1 with the carbon dioxide equivalent range from 2539 to 4157?ton?ha^?1 in 100?year of rotation period. The maximum mean annual growth of 19.98?m³ ha^?1 was estimated in the Great Sandy sub-region while the lowest value of 11.46?m³?ha^?1 was predicted in South Burnett sub-region. The findings indicated that the whole region has a high potential carbon sequestration capability but requires further spatial suitability and economic analysis.     

Enhancing efficiency of Fast Green FCF–Fructose photogalvanic solar cell by using surfactant in natural sunlight

The photogalvanic (PG) cells including the Fast Green FCF dye sensitiser with Fructose-reductant-based PG cells have been extensively studied at low intensity artificial sunlight. These cells have to show very high electrical output that too at natural sun intensity for being practically significant and applicable in daily life. Therefore, the present study of PGs of Fast Green FCF–Fructose with an efficiency enhancer chemical like sodium lauryl sulphate surfactant in an alkaline medium has been done to see their workable feasibility in natural sunlight with an investigation of optimal fabrication parameters. The cell has been found workable in natural sunlight with a greatly enhanced optimum cell performance compared to that for reported similar cells. The optimum cell performance in terms of maximum power, short-circuit current, open-circuit potential, efficiency and storage capacity (as half change time) is of the order of 649.6?µW, 2250?µ|A, 1048?mV, 8.12% and 59?min, respectively.     

Determination of optimum thickness of double-glazed windows for the climatic regions of Turkey

In this study, the optimum air layer thickness of double-glazed windows is determined using the degree-days method. Calculations are obtained for ?skenderun, Kocaeli, Ankara and Ardahan which are in different climate zones of Turkey. Heating cost of the objective function is calculated for natural gas, coal, fuel-oil, electricity and LPG. The optimum air layer thickness is obtained for three different base temperatures which are 18, 20 and 22 °C. The results show that the optimum air layer thickness varies between about 12 and 15 mm depending on the climate zone, fuel type and base temperature. The effect of the fuel type and the base temperature on the optimum air layer thickness diminishes in cold zones. It is shown that with a well-optimized glazed window, up to 60% energy saving can be achieved.     

Embodied energy analysis of the indirect solar drying unit

The increase in cost of fossil fuel and unavailability of electricity are the barrier for farmers to run their farm machineries and their development. Solar drying is a technique that not only helps in reducing fossil fuels and greenhouse gas emission by avoiding the use of machines in this sector, but also reduces the post-harvest food losses too. In present study, embodied energy analysis has been done for indirect solar dryer unit. Fenugreek leaves of 02?kg were put in each tray inside indirect solar dryer unit for drying purposes. Various environmental and economic parameters have been evaluated, which includes the payback period by cost, the energy payback time (EPBT), embodied energy, CO₂ emission and the earned carbon credit. The total embodied energy of the system is 1081.83?kWh. The EPBT and CO₂ emission are found to be 4.36 years and 391.52?kg per year, respectively.     

Novel mold‐resistant building materials impregnated with thermally reduced nano‐silver

In this study, we evaluated the long‐term antifungal effectiveness of 3 types of interior building materials (gypsum board [GB], cement board [CB], and softwood plywood [S‐PW]) impregnated with thermally reduced silver nanoparticles supported by titanium dioxide (AgNPs/TiO₂) under 95% relative humidity for 4 weeks. AgNPs/TiO₂ was synthesized at 2 thermal reduction temperatures (TRTs, 120 and 200°C) with 2 different AgNP weight percentages (2 and 5 wt%). Four different silver‐loading levels (SLLs, 0.025, 0.05, and 0.5 μg/cm² and the critical concentration required to inhibit fungal growth on agar plates) and 3 fungal species (Aspergillus niger, Penicillium spinulosum, and Stachybotrys chartarum) were used in the experiments. Higher temperature reduced more ionic Ag⁺ to metallic Ag⁰ and increased the dispersion of Ag on TiO₂ surface. The 200°C thermally reduced AgNPs/TiO₂ demonstrated excellent antifungal efficiency: Mold growth was almost completely inhibited for 28 days at the low SLL of 0.5 μg/cm². Additionally, AgNPs/TiO₂ exhibited higher antifungal activity on GB and CB than on S‐PW. The stepwise regression results indicated that the TRT of AgNPs/TiO₂ (β = ?0.739 to ?0.51), the SLL (β = ?0.477 to ?0.269), and the Ag⁰ level in the AgNPs (β = ?0.379 to ?0.136) were the major factors influencing antifungal activity and TRT might be the most significant one.     

Zur Absch?tzung von W?rmeleitf?higkeiten der oberfl?chennahen Lockergesteinsschichtenfolge in Norddeutschland

In the course of a groundwater investigation program in east Schleswig-Holstein, groundwater temperature measurements were performed in groundwater observation wells. First, the heat flux density of the investigation area was determined. The heat flow ranged from 20 to 77?mW?m^?2. Near the boundaries of the area, subsurface salt structures cause an increase in heat flow to the earth’s surface. In the centre of this region the heat flow is due to convective processes, and is somewhat low. Here the groundwater recharge as well as the influx from top to bottom affects the temperature field. By means of heat flux densities and the measured temperature gradients, the thermal conductivity was estimated. For clays in the study area the thermal conductivity averaged 1.4?W?m^?1?K^?1 ranging between 1.1 and 1.7?W?m^?1?K^?1. For the coarse grained sand the conductivity was 3.0?W?m^?1?K^?1 and for the fine sands it was 2.8?W?m^?1?K^?1. Due to its heterogeneity, the thermal conductivity of the till ranged between 1.6 and 2.8?W?m^?1?K^?1, depending on the mineralogical composition, the bulk density and the water content of the till. The average thermal conductivity was 2.1?W?m^?1?K^?1.     

Experimental analysis of thermal performance of evacuated tube solar air collector with phase change material for sunshine and off-sunshine hours

An experimental investigation of an evacuated tube solar air collector coupled to a latent thermal energy store for generating hot air when no solar radiation is incident was undertaken. Acetamide was used as a phase change material (PCM). The latent thermal energy store was integrated with the manifold of the solar collector and water was used as the working fluid transferring solar gain to the air being heated. The maximum measured temperature differential between the heated air and the ambient air was 37°C and 20.2°C during conditions of incident and non-incident solar radiation, respectively. This occurred using a circular fin configuration at a flow rate of 0.018?kg?s^?1. The efficiency at low (0.018?kg?s^?1) air flow rates was 0.05–0.50 times less as compared to high (0.035?kg?s^?1) air flow rates. This system has advantages over systems using sensible storage as it can be used after sunset due to better heat storing capacity of the PCM.     

Efficient electricity production and simultaneously wastewater treatment via a high-performance photocatalytic fuel cell

A great quantity of wastewater were discharged into water body, causing serious environmental pollution. Meanwhile, the organic compounds in wastewater are important sources of energy. In this work, a high-performance short TiO₂ nanotube array (STNA) electrode was applied as photoanode material in a novel photocatalytic fuel cell (PFC) system for electricity production and simultaneously wastewater treatment. The results of current work demonstrate that various model compounds as well as real wastewater samples can be used as substrates for the PFC system. As a representative of model compounds, the acetic acid solution produces the highest cell performance with short-circuit current density 1.42 mA cm⁻², open-circuit voltage 1.48 V and maximum power density output 0.67 mW cm⁻². The STNA photoanode reveals obviously enhanced cell performance compared with TiO₂ nanoparticulate film electrode or other long nanotubes electrode. Moreover, the photoanode material, electrolyte concentration, pH of the initial solution, and cathode material were found to be important factors influencing the system performance of PFC. Therefore, the proposed fuel cell system provides a novel way of energy conversion and effective disposal mode of organics and serves well as a promising technology for wastewater treatment.     

Impacts of land use/cover changes on carbon storage in Beijing 1990–2010

According to the data sets of land use/land cover (LULC) in 1990, 1995, 2000, 2005 and 2010, and carbon pools of each LULC category, we estimated the carbon storage of Beijing and each district from 1990 to 2010 by InVEST model. The results indicate that the carbon storage of Beijing ranged from 1.29?×?10⁸ t C to 1.23?×?10⁸ t C over the last 20 years, and decreased 5.6?×?10⁶ t C. The carbon storage is mainly located in suburbs. The cropland turned into construction land causes the continual depletion of carbon storage, which is accompanied by continual urbanization.     

The use of indigenous coal reserves for the removal of lead(II) from the aquatic environment by adsorption

Activated carbon was prepared as an adsorbent from low cost Lakhra coal (LC) (Lignite grade) by chemical activation for the removal of Pb(II) from aqueous solution. The variables of pH, adsorbent dose, agitation time, ionic strength and temperature were investigated. The sorption process followed pseudo-first-order kinetics, intra-particle diffusion and Langmuir isotherm models. Evaluation of thermodynamic parameters affirmed the spontaneity of the process. The study also included the surface properties of activated Lakhra coal (ALC) by FTIR, scanning electron microscope and energy dispersive spectroscopy. The maximum Pb(II) removal capacity of ALC was 758?±?8?mg?g^?1 at 32?°C, approximately 300 times higher than without activation. This value was higher than other previously reported values. Thus, this study demonstrated that indigenous LC has excellent potential to be used as an economically feasible adsorbent after activation for the treatment of wastewater bearing Pb(II).