Key Engineering Materials Vol. 873

Abstract: Fresh whole flowers of the butterfly pea were extracted with 95% ethanol and analyzed the antioxidant activity. The total phenolic content (TPC) of butterfly pea ethanolic extract (BE) was 26.90±1.12 mg gallic acid equivalents/g of dry weight and radical DPPH scavenging activity of ethanolic extract was. The ethanolic extract-loaded Nanostructured Lipid Carriers called BE-NLC were prepared by the high shear homogenization method using compritol 888 ATO, miglyol oil, poloxamer 188, extract and tween 80, respectively. Particle size, polydispersity index, zeta potential 27.78±0.12 mg Trolox equivalents/g of dry weight and entrapment efficiency (EE) were determined. The morphology of the BE-NLC was spherical. The entrapment efficiency of extract was 72.51±1.11% in NLC system. Antioxidant activity was evaluated by the estimation of peroxide values (PVs) of fish oil from catfish, treated with natural antioxidant (BE and BE-NLC) and compared with butylated hydroxy toluene (BHT) as synthetic antioxidant by incubating at 65 °C for a period of 12 days. BHT was found to have higher antioxidant activity than BE and BE-NLC in fish oil. Treatment containing BE-NLC and BHT in fish oil showed similar PVs after the 4 days. However, the antioxidant activity of BE-NLC in stabilization of fish oil is higher than that of BE.

Abstract: Osmotic dehydration is an effective pretreatment method for preservation of herb, fruits and vegetables. This method can be conducted at low temperature so it can maintain the nutritional composition and food quality. In the present study, the effect of osmotic dehydration in 50, 60 and 70o Brix sugar solution at 40oC syrup temperature and drying air temperature (50, 60, 70 oC) on drying behavior of sample (adlay and black sesame seeds) were investigated before drying the sample and determined the percentage yield and total phenolic contents. All results from osmotic dehydration were compared with the soxhlet and maceration extraction methods. Among the three concentration of osmotic agents and drying temperature, percentage yield and total phenolic contents were higher at 70% concentration of osmotic agents and 60 oC air temperature which exhibited the total phenolic contents at 11.29±1.13 mg GAE/g extract and percentage yield of 4.36±0.34, respectively. From this osmotic dehydration, the surface morphologies of prepared bead containing sample had higher degree of surface smoothness and more spherical shape than non-sample bead and exhibited the encapsulation efficiency of micro-bead sample at 80.52 ± 0.36%.

Abstract: Currently, construction industry is unsustainable in nature due to the over dependency on the energy consumptive materials. Thus, to transform the industry from unsustainable to sustainable focus is on innovative materials developed from locally available waste. In this research, focus is on development of alkali activated binder using combination of fly ash (FA), rice husk ash (RHA) and bottom ash (BA) as an alumina silicate source material. Further, thermal performance of the developed material has been studied to understand its impact on the heat transfer and insulation characteristic s of the material. The alkali activated binder developed from bottom ash shows better performance than rice husk ash (RHA) based binder. However, the thermal performance of the rice husk ash binder is more suited for the insulation due to its low thermal characteristics. The lowest thermal conductivity for the developed binder was having value of 0.31 W/m2K for rice husk ash (RHA) based binder.

Abstract: Environmental pollution due to heavy metals is a matter of great concern to many scientists and managers worldwide. The threats to human health from heavy metals are primarily associated with the exposure in agriculture production activities. However, a considerable number of technological methods have been used to remove the heavy metals from polluted soils. One of the simplest measures to effectively remove heavy metal contamination is to use both plants and microorganisms, which have been considered "natural materials" or "Bio-Materials" to treat pollutants. This study was conducted on assessing the ability of Trichoderma to absorb heavy metals into the plant. Phytoremediation experiments with Trichoderma were used to remove heavy metals in the soil. Our findings showed that Dracaena Fragrans plants are capable of absorbing heavy metals Cu, Pb, and Zn in soil contaminated with experimental heavy metals.

Abstract: Lightweight Steel (LWS) systems, made of Cold Formed Steel (CFS) profiles, are widespread in seismic areas and often preferred to traditional systems. Improving structural performances in order to have higher building is now the goal, which could be achieved thanks to the use of steel innovative material. In particular, to increase the seismic performances of CFS buildings, the University of Naples “Federico II”, in cooperation with the Italian company Lamieredil S.p.A., has developed an innovative Lateral Force Resisting System (LFRS). The LFRS mainly consists of CFS frame (studs and tracks) braced by “V” shaped pre-tensioned Ultra High Strength (UHS) steel bars. The bracing was designed to be able to limit global displacement of structure, working as elastic spring, and to dissipate seismic energy by yielding. In order to prove the effectiveness of the new system, an extensive experimental campaign has been conducted. This paper focuses on material and component tests, describing tension tests on traditional materials and UHS steel, creep tests on UHS steel and nut-bar assembly tests.

Abstract: Steel moment resisting frames (MRFs) compliant with EN1998-1 are generally overdesigned in order to satisfy the requirements for lateral deformability and P-Delta effects. On the contrary, the North American codes (e.g. ASCE7) give different rules for P-Delta effects. The current draft version of the amended EN1998-1-1 introduces a different methodology to account for the structural lateral displacements. In this paper static non-linear analyses were carried out to evaluate the effectiveness of the new EC8 provisions with respect to the former version of EC8 and the current ASCE7. The results show that the structures designed according to the latest draft version of the EN1998-1-1 and those compliant with the North American code exhibit similar behavior.

Abstract: The wind-blown sand in Taklimakan Desert was mixed with powder and clay particles to carry out heavy compaction and surface vibration compaction tests. The results show that the surface vibration compaction effect of aeolian sand is better when the water content is extremely low or saturated, but the effect is worse when the water content is about 2% ~ 4%, but it is still better than heavy compaction. With the increase of silt content, the surface vibration compaction effect decreases little in a wide range, but at and near the boundary where the dry compaction effect changes from obvious to inconspicuous, the surface vibration compaction effect decreases rapidly, which is soon lower than that of heavy compaction. In addition, with the increase of silt content, the reduction degree of surface vibration compaction effect is also affected by water content: the reduction is smaller when the water content is extremely low, followed by the reduction when saturated or optimal water content, and the reduction is the largest when the water content is about 2% ~ 4%. The research results are beneficial to the popularization and application of surface vibration compaction, especially in the dry compaction technology of aeolian sand subgrade.

Abstract: For structural health of mechanical structures, non-destructive detection and material defect characterization represent the main useful tools for mechanical decay prediction caused by local composite damage phenomena. In this work, internal delamination due to alternate bending were characterized in flat specimens, performing fatigue and static tests, coupled with thermographic, optical, and ultrasonic analysis for damage detection and evolution purposes. Damage to rupture behavior of CFRP material through mechanical tensile tests is performed on several samples and non-destructive inspection procedures are optimized during successive HCF tests to detect in real time local compliance variations and damage initiation. Thermographic continuous monitoring and occasional ultrasonic analysis are implemented to analyze composite anomalies during fatigue life and to elaborate a procedure for identification of delamination induced damage before failure. IRT and UT results are computed with MATLAB analysis for damage evaluation with strain and compliance data acquired during tests.

Abstract: The surface wettability of thermo-responsive random poly (ethylene glycol methyl ether methacrylate-co-triethylene glycol methyl ether methacrylate), abbreviated as P(MEOMA-co-MEO₃MA), was investigated in thin film. UV-Vis spectroscopy shows that the LCST of P(MEOMA-co-MEO₃MA) with molar ratios of 0:20, 6:14 and 9:11 were 43°C, 32 ^oC and 25 ^oC, respectively. LCST shifts towards lower temperature when molar ratio of MEOMA increases. ATR-FTIR indicates that P(MEOMA-co-MEO₃MA) thin film experienced a collapse when the temperature passes its LCST. The contact angle of the paraffin oil on the film decreases 15^o when the temperature is above its LCST, which confirms the surface wettability can be controlled. Atomic force microscopy shows the surface of the swollen thin film becomes rougher when above it LCST.