Investigation of relation between both sulfur removal and adsorption capacity with surface morphology of a pyrolysed Turkish lignite

In considering with morphological physicochemical transformations of the coal samples pyrolysed in CO₂ atmosphere at different temperatures, the change of their adsorptive capacities have been investigated. It was seen that the change occurred in the monolayer adsorption capacities as parallel to morphological transformations of the coal surface is particularly connected with the amount of organic sulfur present in the coal matrix. Adsorption capacity is not affected from the contents of pyritic sulfur and ash of coal samples. The measurements of zeta potential of the pyrolysed coal samples also showed that pyrolysis modified the functional groups on surface of the coal, depending on the pyrolysis temperature.     

Emulsifying properties of canola and flaxseed protein isolates produced by isoelectric precipitation and salt extraction

The emulsifying (emulsion capacity, EC; emulsion activity/stability indices, EAI–ESI and creaming stability, CS) and physicochemical properties (surface charge/hydrophobicity, protein solubility, interfacial tension, and droplet size) of chickpea (ChPI), faba bean (FbPI), lentil (LPI), and pea (PPI) protein isolates produced by isoelectric precipitation and salt extraction were investigated relative to each other and a soy protein isolate (SPI). Both the legume source and method of isolate production showed significant effects on the emulsifying and physicochemical properties of the proteins tested. All legume proteins carried a net negative charge at neutral pH, and had surface hydrophobicity values ranging between 53.0 and 84.8 (H₀-ANS), with PPI showing the highest value. Isoelectric precipitation resulted in isolates with higher surface charge and solubility compared to those produced via salt extraction. The EC values ranged between 476 and 542 g oil/g protein with LPI showing the highest capacity. Isoelectric-precipitated ChPI and LPI had relatively high surface charges (~−22.3 mV) and formed emulsions with smaller droplet sizes (~ 1.6 μm), they also displayed high EAI (~ 46.2 m²/g), ESI (~ 84.9 min) and CS (98.6%) results, which were comparable to the SPI.     

Effects of different prebiotic stabilisers and types of molasses on physicochemical,sensory, colour and mineral characteristics of probiotic set yoghurt

The physicochemical, sensory, properties and mineral profile of probiotic set yoghurts prepared with different prebiotic stabilisers (pectin and guar) at 0.5% (w/v) and different molasses (grape, mulberry and carob) at 10% (v/v) were investigated. Guar‐supplemented yoghurts had the lowest titratable acidity values (P < 0.01) also the highest water‐holding capacity values (P < 0.01). However, guar had a negative effect on gel firmness and sensory properties of yoghurts. The effect of different stabilisers and molasses on colour L* and a*values was statistically significant (P < 0.01). Panelists gave the highest flavour scores to the pectin‐added yoghurts during storage period (P < 0.01).     

Decision making with epistemic uncertainty under safety constraints: An application to seismic design

The problem of accounting for epistemic uncertainty in risk management decisions is conceptually straightforward, but is riddled with practical difficulties. Simple approximations are often used whereby future variations in epistemic uncertainty are ignored or worst-case scenarios are postulated. These strategies tend to produce sub-optimal decisions. We develop a general framework based on Bayesian decision theory and exemplify it for the case of seismic design of buildings. When temporal fluctuations of the epistemic uncertainties and regulatory safety constraints are included, the optimal level of seismic protection exceeds the normative level at the time of construction. Optimal Bayesian decisions do not depend on the aleatory or epistemic nature of the uncertainties, but only on the total (epistemic plus aleatory) uncertainty and how that total uncertainty varies randomly during the lifetime of the project.     

Phase detector for tuning circuit of resonant inverters

The tuning circuit in a resonant inverter determines the inverter frequency and makes it track the load resonant frequency. Current phase detectors have some serious drawbacks for this application. A new phase detector circuit is presented which can overcome these drawbacks.     

Thermomechanical and shape memory properties of thermosetting shape memory polymer under compressive loadings

Shape memory polymers (SMPs) are an emerging class of active polymers that may be used for a range of reconfigurable structures. In this study, the thermomechanical and shape memory behavior of a thermosetting SMP was investigated using large‐scale compressive tests and small‐scale indentation tests. Results show that the SMP exhibits different deformation modes and mechanical properties in compression than in tension. In glassy state, the SMP displays significant plastic deformation and has a much higher modulus and yield strength in comparison to those obtained in tension. In rubbery state, the SMP behaves like a hyperelastic material and again has a much higher modulus than that obtained in tension. The SMPs were further conditioned separately in simulated service environments relevant to Air Force missions, namely, (1) exposure to UV radiation, (2) immersion in jet‐oil, and (3) immersion in water. The thermomechanical and shape recovery properties of the original and conditioned SMPs were examined under compression. Results show that all the conditioned SMPs exhibit a decrease in T_g as compared to the original SMP. Environmental conditionings generally result in higher moduli and yield strength of the SMPs in the glassy state but lower modulus in the rubbery state. In particular, the UV exposure and water immersion, also weaken the shape recovery abilities of the SMPs. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Adsorption of cationic dye from aqueous solutions by activated carbon

Batch sorption experiments were carried out to remove a cationic dye, methylene blue (MB), from its aqueous solutions using a commercial activated carbon as an adsorbent. Operating variables studied were pH, stirring speed, initial methylene blue concentration and temperature. Adsorption process was attained to the equilibrium within 5 min. The adsorbed amount MB dye on activated carbon slightly changed with increasing pH, and temperature, indicating an endothermic process. The adsorption capacity of methylene blue did not significantly change with increasing stirring speed. The experimental data were analyzed by various isotherm models, and found that the isotherm data were reasonably well correlated by Langmuir isotherm. Adsorption measurements showed that the process was very fast and physical in nature. Thermodynamic parameters such as the adsorption entropy (ΔS^o) and adsorption enthalpy (ΔH^o) were also calculated as 0.165 kJ mol⁻¹ K⁻¹ and 49.195 kJ mol⁻¹, respectively. The ΔG^o values varied in range with the mean values showing a gradual increase from −0.256 to −0.780 to −2.764 and −7.914 kJ mol⁻¹ for 293, 313, 323 and 333 K, respectively, in accordance with the positive adsorption entropy value of the adsorption process.     

Effect of additive cashew grain size on brake performance of non-asbestos linings

Journal of Mechanical Science and Technology - The most important parameter in lining production is determining and combining the material composition. The amount of these materials in the...     

Galvanostatic synthesis of nanostructured Ag-Ag2O dispersed PPy composite on graphite electrode for supercapacitor applications

Polypyrrole (PPy) and nanostructured Ag-Ag₂O were co-deposited galvanostatically on the Ag-intercalated graphite electrode in acetonitrile/TBABF₄ solution with AgBF₄, Py, HBF₄, H₂O, and sodium carboxymethyl cellulose (CMC). The effects of additives and intercalation on the capacitive behaviors of PPy-Ag-Ag₂O-CMC composite (4.0 mg/cm²) were studied in H₂SO₄ (0.1 M) solution by using cyclic voltammetry and electrochemical impedance spectroscopy methods. The composite coating was characterized using X-ray photoelectron spectroscopy, transmission electron microscopy, X-ray diffraction (XRD), Brunauer, Emmett, and Teller, and scanning electron microscopy (SEM) energy dispersive X-ray spectroscopy. The incorporation of nano-sized Ag-Ag₂O particles and CMC into the composite has significant impacts on the morphology, which also greatly influences the capacitive performance. XRD and SEM studies showed that the electrochemical intercalation of silver in acetonitrile medium provided partially exfoliated surface of graphite, thus the capacitive properties further enhanced. The capacitive properties of the composite coating were also tested using the galvanostatic charge–discharge method. The specific capacitance of the composite coated electrode was calculated as 500 F/g at 2.0 A/g in H₂SO₄ solution by subtracting the capacitance of bare graphite electrode. Asymmetric and symmetric supercapacitor configurations were utilized to examine the capacitive performance of PPy-Ag-Ag₂O-CMC composite (10 mg/cm²) on Ag-intercalated graphite paper. The asymmetric supercapacitor providing a power density of 0.51 kW/kg at 2.0 A/g and an energy density of 23.6 Wh/kg maintains 62% of its capacitance after 5000 cycles.