Quality improvement of kenaf-based tofu: effects of kenaf seed substitution,and coagulant types and concentrations on the physicochemical quality,texture profile and microstructure of the tofu

Tofu was made by substituting kenaf seed (K) with soybean (S) at 100 (positive control), 50%, 40%, 30%, 20%, 10% and 0% (negative control). The results indicated that kenaf seed substitution at all ratios significantly increased the soluble solids and protein content of the milky extracts. The yield, moisture and protein content of the tofu were significantly increased with the increase in kenaf seed substitution, while the lipid content was significantly decreased. The tofu made with kenaf seed substitution of 50%, 40% and 30% had the same protein content (43.76–45.36 g/100 g) with the positive control (45.36 g/100 g), but a significantly higher lipid content (32.00–35.75 g/100 g) than that of the positive control (27.50 g/100 g). The microstructure of the tofu revealed that only the positive control had a honey-comb structure, whilst the tofu made from kenaf seed-soybean blends had a pseudo-honey like structure. Up to 30% of soybean can be added into the kenaf-based tofu, without any negative effect on the textural and colour properties and, protein content, but significantly improved the essential amino acids content of the kenaf-based tofu. Therefore, the blend of 70K:30S ratio using 0.5 g% glucono delta-lactone as a coagulant is recommended to produce kenaf seed-soybean tofu.     

Selective oxidation of cyclohexane over the bi-functional catalysts Co-MO-TUD-1 (MO = Al2O3, CeO2, NiO,or ZnO)

Journal of Porous Materials - The selective oxidation of cyclohexane was catalyzed by applying a new series of catalytic materials. The new catalytic series consists of two different active sites...     

Optical,FTIR and DC Conductivity of Soda Lime Silicate Glass Containing Cement Dust and Transition Metal Ions

Four soda lime silicate glass samples of composition (70 % SiO₂+ 20 % Na₂O+ 10 % CaO mol %) were prepared after adding 5 wt% cement dust to each sample mixture besides 0.1 wt% of one transition metal (TM) oxide of Fe, Co or Cu. The four samples were melted by a conventional melt-annealing technique at 1400 ^°C for 2.5 h. Density, UV/VIS, FTIR and DC conductivity measurements were performed for each glass. Experimental results indicate that there are only slight differences in the density values. The optical spectra reveal that the TM free sample and the sample containing iron ions have the same spectral features while the samples containing copper or cobalt exhibit distinct characteristic absorption bands due to each TM ion. FTIR spectra reveal characteristic vibrational bands due to stretching and bending modes of the silicate network. DC conductivity data show variations in the values of the studied samples according to the type of TM ions added. All the experimental results were correlated with each other in accordance with the current views on the constitution of the studied glasses.     

Failure Analysis of Tool Steel-Based Compaction Punch Used in Powder Metallurgy

Powder metallurgy operations comprise the use of compaction dies and punches for transforming a mass of metallic powders into a porous block of aggregated particles with limited “green” strength. In this kind of application, dies and punches manufactured with tool steel are subjected to heavy loads to compress the metallic powders and form the block, which will be subjected to further consolidation operations such as sintering and/or some mechanical forming operation, such as forging or rolling. In general tool steels are high carbon and high alloyed steels designed for reaching high levels of mechanical strength, sufficient for his type of loading. However, defects on the surface of this material can lead to stress concentration, thus decreasing its fracture strength and eventually leading to failure. In this study, techniques such as optical and scanning electron microscopy are used to evaluate the possible causes of the failure of a compaction punch. The results indicated that machining grooves acted as stress concentrations which led to the premature fracture of the punch.     

A computationally efficient technique for real-time detection of particular-slope edges

Identification of oblique lines of a particular slope is needed for various applications such as motion tracking for smart cameras. Wavelets and gradient-based techniques, such as Sobel and Canny, do not classify edges based on their slopes. The Hough transform (HT) does classify edges based on their slopes but with high computational complexity, even using its most improved versions. This paper presents a computationally efficient technique for detecting edges of a particular slope. The angle of the required edges is converted into pixel increments over rows and columns. Using these two simple parameters, parallel, oblique lines of a particular slope are formed. A first-order, orthonormal Haar low-pass filter (LPF) is used over the formed lines to filter out undesired edges. The hardware architecture of the proposed technique is fully described, including processing time, based on the number of clock cycles, and fixed-point implementation. A line-based memory mechanism was used to minimize the memory requirements to two simple registers. To demonstrate the computational advantage of the proposed technique, it is compared to the Sobel, Canny and HT detectors.     

Interpretation of the Superpave IDT strength test using a viscoelastic-damage constitutive model

This paper presents a new interpretation for the Superpave IDT strength test based on a viscoelastic-damage framework. The framework is based on continuum damage mechanics and the thermodynamics of irreversible processes with an anisotropic damage representation. The new approach introduces considerations for the viscoelastic effects and the damage accumulation that accompanies the fracture process in the interpretation of the Superpave IDT strength test for the identification of the Dissipated Creep Strain Energy (DCSE) limit from the test result. The viscoelastic model is implemented in a Finite Element Method (FEM) program for the simulation of the Superpave IDT strength test. The DCSE values obtained using the new approach is compared with the values obtained using the conventional approach to evaluate the validity of the assumptions made in the conventional interpretation of the test results. The result shows that the conventional approach over-estimates the DCSE value with increasing estimation error at higher deformation rates.     

Exergetic and sustainability performance comparison of novel and conventional air cooling systems for building applications

This study presents energy and exergy analyses and sustainability assessment of one novel and three conventional types of air cooling systems for building applications. First, effectivenesses of the systems are determined using energy analysis method. Second, exergy aspects of the systems are investigated for twelve different dead state temperatures varying from −5 °C to 50 °C with a temperature interval of 5 °C. The specific exergy flows of humid air, dry air and water, exergy efficiency, and specific exergy destruction are then calculated. Sustainability index is also used to define and discuss the systems’ sustainability aspects. Finally, the results obtained here show that at the dead state temperatures of higher than 23 °C (comfort temperature), exergy efficiency and sustainability of the novel system, which is based on the novel Maisotsenko cycle (M-Cycle), is higher than those of the conventional systems. At a dead state temperature of 50 °C, novel cooling system's exergy efficiency can reach 60.329% as the maximum, while the minimum exergy efficiency of other conventional cooling systems becomes as low as 35.866%, respectively.     

Density and humidity gradients in veneers of oil palm stems

Large variations in the stem of oil palm in terms of moisture content and density hinder its full utilization in the plywood industry. In this study, the density and moisture content (MC) pattern throughout the trunk of the oil palm tree were measured and established. The veneer samples were taken from various sections i.e., top, bottom, outer and inner parts of the trunk and the density and moisture content of each veneer were then measured. The results showed that there was a decrease of density and an increase of moisture content in the veneers as they were peeled progressively towards the inner portion of the trunk. It was also discovered that veneers taken from the top part of the stem had higher density but did not have a significant difference in MC compared to veneers taken from the bottom part of the stem.     

Generalized Magneto-thermoelastic Interaction in a Fiber-Reinforced Anisotropic Hollow Cylinder

In this article, an estimation is made to investigate the transient phenomena in the magneto-thermoelastic model in the context of the Lord and Shulman theory in a perfectly conducting medium. A finite element method is proposed to analyze the problem and obtain numerical solutions for the displacement, temperature, and radial and hoop stresses. The boundary conditions for the mechanical and Maxwell’s stresses at the internal and outer surfaces are considered. An application of a hollow cylinder is investigated where the inner surface is traction free and subjected to thermal shock, while the outer surface is traction free and thermally isolated. The displacement, incremental temperature, and the stress components are obtained and then presented graphically. Finally, the effects of the presence and absence of reinforcement on the temperature, stress, and displacement are studied.