Mechanochemical durability and self-cleaning performance of zinc oxide-epoxy superhydrophobic coating prepared via a facile one-step approach

Research efforts have intensified on developing superhydrophobic ZnO nanoparticle-based surfaces as they can impart desired hierarchical rough structures and properties. However, the widespread use of these surfaces is impeded by the limitations: complex fabrication procedures, weak adhesion, and limited durability performance. Most of these fabrication processes involved multiple treatment steps included the pre/post-treatment process to modify the textured surfaces. Herein, a convenient and effective one-step strategy is used to synthesis superhydrophobic ZnO-based coating with the introduction of both epoxy resin (EP) as the adhesive promoter and stearic acid (SA) as the low-energy modifier into an aqueous solution containing ZnO nanoparticles and ethanol via solution coating deposition method that binds all the components in a sole system. In the dense network, EP is responsible to render mechanical strength and coating-substrate adhesion, meanwhile, whereas SA functions to reduce the surface energy and preventing the EP to fully envelop the ZnO nanoparticles, thereby achieving a robust hierarchical rough structure, creating a layer of trapped air pockets. The resultant coating exhibits high water repellency, low water adhesion, and excellent self-cleaning ability with water contact and a sliding angle of 160.24° and 3°, respectively. Besides that, the superhydrophobic coating exhibited good mechanical durability after subjected to sandpaper-abrasion for a 20-m distance long and tape-peeling for 200 cycles. Furthermore, the coating still retained its superhydrophobicity after immersed in the corrosive bath with pH concentration ranged from 1 to 13 for 3 h, as well as the direct exposure to the temperature changes from 0 to 150 °C, manifesting its good chemical and thermal stability. This straightforward yet effective approach to develop a superhydrophobic coating with good durability and self-cleaning performance will inspire the scalable fabrication of multifunctional surfaces for practical applications in self-cleaning.     

Optimizing endopectinase production from date pomace by Aspergillus niger PC5 using response surface methodology

In the first stage of experiments, a two-level fractional factorial design was used for screening of the most important factors among concentration of ammonium sulfate, potassium dihydrogen phosphate and date pomace, pH, total spore amount, aeration rate and fermentation time for the production of endopectinase from date pomace by Aspergillus niger PC5. Based on the results of first stage, ammonium sulfate (0.25–0.45%), pH (4.82–6.12) and fermentation time (50–90 h) were selected to be studied further. In the second stage, response surface methodology was used to determine the optimum fermentation conditions for production of the enzyme. Second stage results showed that, fermentation time was the most significant factor on endopectinase activity. After modeling of the fermentation process, maximum amounts of endopectinase (10.88 U ml^?1) predicted to be in the following fermentation conditions: pH of medium 5, ammonium sulfate concentration of 0.3% and fermentation time of 76.05 h.     

An experimental investigation on the use of EGR in a supercharged natural gas SI engine

The use of lean burn technology in spark-ignition engines has been dominant; however, lean burn technique can not economically satisfy the increasingly restricted future emission standards. Consequently, alternative combustion techniques need to be investigated and developed. In this paper, the use of the stoichiometric air-fuel mixture with exhaust gas recirculation (EGR) technique in a spark-ignition natural gas engine was experimentally investigated. Engine performance and NO emissions were studied for both atmospheric and supercharged inlet conditions. It was found that the use of EGR has a significant effect on NO emissions. NO emissions decreased by about 50% when EGR dilution increased from zero with an inlet pressure of 101 kPa to close to the misfire limit with an inlet pressure of 113 kPa. In addition, the use of EGR effectively suppressed abnormal combustion which occurred at higher inlet pressure. The use of higher inlet pressure in the presence of EGR improved engine performance significantly. Engine brake power increased by about 20% and engine fuel consumption decreased by about 7% while NO emissions decreased by about 12% when 5% of EGR dilution was employed with an inlet pressure of 113 kPa compared to using undiluted stoichiometric inlet mixture with an inlet pressure of 101 kPa.     

Comparative Analysis of Mafriwal (Bos taurus × Bos indicus) and Kedah Kelantan (Bos indicus) Sperm Proteome Identifies Sperm Proteins Potentially Responsible for Higher Fertility in a Tropical Climate

The fertility of zebu cattle (Bos indicus) is higher than that of the European purebred (Bos taurus) and crossbred (Bos taurus × Bos indicus) cattle in tropical areas. To identify proteins related to the higher thermo-tolerance and fertility of Zebu cattle, this study was undertaken to identify differences in sperm proteome between the high fertile Malaysian indigenous zebu cattle (Kedah Kelantan) and the sub-fertile crossbred cattle (Mafriwal). Frozen semen from three high performance bulls from each breed were processed to obtain live and pure sperm. Sperm proteins were then extracted, and two-dimensional gel electrophoresis performed to compare proteome profiles. Gel image analysis identified protein spots of interest which were then identified by liquid chromatography mass spectrometry quadrupole time-of-flight (LC MS/MS Q-TOF). STRING network analysis predicted interactions between at least 20 of the identified proteins. Among the identified proteins, a number of motility and energy related proteins were present in greater abundance in Kedah Kelantan. Sperm motility evaluation by Computer Assisted Semen Analysis (CASA) confirmed significantly higher motility in Kedah Kelantan. While results from this study do identify proteins that may be responsible for the higher fertility of Kedah Kelantan, functional characterization of these proteins is warranted to reinforce our understanding of their roles in sperm fertility.     

Formulation of garlic oil‐in‐water nanoemulsion: antimicrobial and physicochemical aspects

Despite the unique properties, application of garlic essential oil (GEO) is too limited in food and drugs, due to its low water solubility, very high volatility and unpleasant odour. In this work, a nanoemulsion containing GEO was formulated to cover and protect the volatile compounds of GEO. The encapsulation efficiency of formulated nanoemulsions was measured by gas chromatography and obtained encapsulation efficiency ranged from 91 to 77% for nanoemulsions containing 5–25% GEO, respectively. The 2,2‐diphenyl‐1‐picrylhydrazyl method for antioxidant activity measurement showed that free radical scavenging capacity of nanoemulsions intensified during storage time. The electrical conductivity of the samples was constant over storage time while linearly increased by raising the temperature. Thermogravimetric analysis was used to determine the thermal resistance of nanoemulsions and their ingredients. Interestingly, microbial tests cleared that the control nanoemulsion with a particle size below 100 nm (nanoemulsion without GEO) also showed antimicrobial activity. Disk diffusion method showed that pure GEO and also formulated nanoemulsions had a stronger effect against Gram‐positive bacterium (Staphylococcus aureus) than Gram‐negative bacterium (Escherichia coli).Inspec keywords: emulsions, nanostructured materials, antibacterial activity, microorganisms, electrical conductivity, thermal analysis, thermal resistance, oils, nanobiotechnology, food safety, cellular biophysicsOther keywords: garlic oil‐in‐water nanoemulsion, antimicrobial aspects, physicochemical aspects, garlic essential oil, GEO, volatile compounds, encapsulation efficiency, gas chromatography, 2,2‐diphenyl‐1‐picrylhydrazyl method, antioxidant activity measurement, free radical scavenging capacity, storage time, electrical conductivity, thermogravimetric analysis, thermal resistance, antimicrobial activity, disk diffusion method, Gram‐positive bacterium, Staphylococcus aureus, Gram‐negative bacterium, Escherichia coli     

How nano‐wollastonite can change the fundamental properties of a wood fibre and rice straw composites?

The potential of using rice straw (RS) in combination with wood fibre in the production of medium density fibreboard was investigated. Nano‐wollastonite (NW) was added to some of the panels to determine if it would enhance the physical and mechanical properties. It was found that satisfactory composite boards could be made with the addition of 10% RS to the wood fibre. Furthermore, the mechanical and physical properties of the composite were enhanced when NW was added.Inspec keywords: wood products, ecocomposites, fibresOther keywords: RS, composite boards, mechanical properties, physical properties, NW, medium density fibreboard, rice straw composites, wood fibre, fundamental properties, nanowollastonite