Progressive Freeze Concentration for Volume Reduction of Produced Water and Biodiesel Wastewater

One way to conserve fresh water resources is by reusing water from wastewater. For instance, water can be removed from wastewater through formation of ice crystal layers by progressive freeze concentration (PFC). The application of PFC to remove water from produced water and biodiesel wastewater was assessed through the final concentration of concentrated wastewater and purity of melted ice crystals. No PFC study has been done on these applications. In order to evaluate the efficiency of PFC, the effective partition constant (K) and separation efficiency (S_E) were calculated for the effect of stirring rate and coolant temperature. The results demonstrate that PFC is a more practical method for produced water, as compared to biodiesel wastewater which is based on the value of low K and high S_E.     

Influence of Hydrogen Bonding on Low Critical Micellar Concentration Value and Formation of Giant Vesicle of Triazole-Contained Amphiphile

An amphiphile molecule consisting of triazole moiety has been thoroughly investigated using different approaches in its aqueous condition. The studies have discovered the explicit function of its heteroaromatic ability in molecular self-assembling. From the fluorescence evidence, the triazole-based amphiphile has shown that the aggregation-induced emission behavior is mainly due to the triazolyl. It suggests that the triazole is directly involved in the self-assembling mechanism through an intermolecular interaction. This interaction can be verified by the shifting of proton frequency of the triazole, which is clearly shown by the constant frequency of the proton above the critical micellar concentration (CMC) value. The frequency suggests the establishing hydrogen bond that occurred between the hydrogen and the second nitrogen of the adjacent triazole. These results are consistent with the micellization of the molecule which was determined at a very low CMC value (0.1 mM). The absorbance and optical polarizing microscopy results also support the evidence of the growth of giant vesicles produced from the neutralization of the amphiphile. The formation of stable giant vesicles at neutral pH demonstrates the immediate strong hydrogen bonding connections within the triazoles layer in the bilayer. The discovery reveals that internal hydrogen bonds formed from a heteroaromatic with the appropriate molecular arrangement can promote self-aggregation and enhance overall stability.     

Circadian Rhythms in Legumes: What Do We Know and What Else Should We Explore?

The natural timing devices of organisms, commonly known as biological clocks, are composed of specific complex folding molecules that interact to regulate the circadian rhythms. Circadian rhythms, the changes or processes that follow a 24-h light–dark cycle, while endogenously programmed, are also influenced by environmental factors, especially in sessile organisms such as plants, which can impact ecosystems and crop productivity. Current knowledge of plant clocks emanates primarily from research on Arabidopsis, which identified the main components of the circadian gene regulation network. Nonetheless, there remain critical knowledge gaps related to the molecular components of circadian rhythms in important crop groups, including the nitrogen-fixing legumes. Additionally, little is known about the synergies and trade-offs between environmental factors and circadian rhythm regulation, especially how these interactions fine-tune the physiological adaptations of the current and future crops in a rapidly changing world. This review highlights what is known so far about the circadian rhythms in legumes, which include major as well as potential future pulse crops that are packed with nutrients, particularly protein. Based on existing literature, this review also identifies the knowledge gaps that should be addressed to build a sustainable food future with the reputed “poor man’s meat”.     

PredNTS: Improved and Robust Prediction of Nitrotyrosine Sites by Integrating Multiple Sequence Features

Nitrotyrosine, which is generated by numerous reactive nitrogen species, is a type of protein post-translational modification. Identification of site-specific nitration modification on tyrosine is a prerequisite to understanding the molecular function of nitrated proteins. Thanks to the progress of machine learning, computational prediction can play a vital role before the biological experimentation. Herein, we developed a computational predictor PredNTS by integrating multiple sequence features including K-mer, composition of k-spaced amino acid pairs (CKSAAP), AAindex, and binary encoding schemes. The important features were selected by the recursive feature elimination approach using a random forest classifier. Finally, we linearly combined the successive random forest (RF) probability scores generated by the different, single encoding-employing RF models. The resultant PredNTS predictor achieved an area under a curve (AUC) of 0.910 using five-fold cross validation. It outperformed the existing predictors on a comprehensive and independent dataset. Furthermore, we investigated several machine learning algorithms to demonstrate the superiority of the employed RF algorithm. The PredNTS is a useful computational resource for the prediction of nitrotyrosine sites. The web-application with the curated datasets of the PredNTS is publicly available.     

Effect of maleic anhydride‐grafted polypropylene on polypropylene/recycled acrylonitrile butadiene rubber/empty fruit bunch composite

The effect of maleic anhydride‐grafted polypropylene (PP‐g‐MAH) as a compatibilizer on the properties of polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr)/empty fruit bunch (EFB) composites were studied. The composites were melt mixed using a heated two roll mill at 180°C and a speed of 15 rpm with six different compositions (100/0/10, 80/20/10, 70/30/10, 60/40/10, 50/50/10, 40/60/10 phr). The effects of PP‐g‐MAH on mechanical, morphological and chemical properties of the PP/NBRr/EFB composites were examined. The PP‐g‐MAH compatibilized composites have higher tensile values compare to uncompatibilized composites. Scanning electron microscopy showed better adhesion between EFB and PP/NBRr matrices in the presence of PP‐g‐MAH. Better interaction was formed between EFB and PP/NBRr matrices via C‐O‐C ester bonds as indicated by FTIR analysis. J. VINYL ADDIT. TECHNOL., 24:275–280, 2018. © 2016 Society of Plastics Engineers     

Polydopamine‐Graphene Oxide Flame Retardant Nanocoatings Applied via an Aqueous Liquid Crystalline Scaffold

A highly effective flame retardant (FR) nanocoating was developed by conducting oxidative polymerization of dopamine monomer within an aqueous liquid crystalline (LC) graphene oxide (GO) scaffold coating. Due to its high water content, the LC scaffold coating approach facilitated fast transport and polymerization of dopamine precursors into polydopamine (PDA) within the water swollen interlayer galleries. Uniform and periodically stacked (14.5 Å d‐spacing) PDA/GO nanocoatings could be universally applied on different surfaces, including macroporous flexible polyurethane (PU) foam and flat substrates such as silicon wafers. Remarkably, PDA/GO coated PU foam exhibited highly efficient flame retardant performance reflected by a 65% reduction in peak heat release rate at 5 wt% PDA/GO loading in an 80 nm thick coating. While many physically mixed flame retardants are usually detrimental to the mechanical properties of the foam, the PDA/GO coating did not affect mechanical properties substantially. In addition, the PDA/GO coatings were stable in water due to the intrinsic adhesion capability of PDA and the transformation of GO to the more hydrophobic reduced GO form. Given that PDA is produced from dopamine, a molecule prevalent in nature, these findings suggest that significant opportunities exist for new polymeric FRs derived from other natural catechols.     

A network selection method for handover in vehicle-to-infrastructure communications in multi-tier networks

Network selection is very important for a successful handover in a multi-tier heterogeneous networks. However, the primary challenges currently faced by research community is the lack of availability of network information at the mobile node side for efficiently select the most appropriate target network. It is practically difficult for an UE to get network information from base stations/access point of the neighbouring networks before connecting to them. In response to this, this paper proposes a network selection method that applies the knowledge of mobility data and the network load information to carry out an efficient handover for vehicle-to-infrastructure communication over multi-tier heterogeneous networks. We first derive key parameters, such as relative direction index, proximity index, residence time index, and network load index to select the best candidate network. A moving vehicle would be able to select the most appropriate target network by selecting one or more of the above parameters. We then test our algorithms by developing a dual mode vehicle On-Board Unit equipped with both Long Term Evolution-Advanced (LTE-A) and Wi-Fi network interface cards in OPNET simulator. The performance of the proposed handover method is evaluated by extensive OPNET-based simulation experiments. In the simulation model, we consider a multi-tier heterogeneous network comprising of a macro and multiple small cells of LTE-A and IEEE 802.11n technologies. Results show that our proposed handover method offers about 50% higher throughput and up to 43% higher packet delivery ratio than the conventional received signal strengths based network selection method.

     

Studies on potential of Portland cement mortar for binding of waterworks sludge to reduce heavy metal leaching

The investigation of heavy metal leaching and physicochemical properties of cement-solidified waterworks sludge (CMWWS) formed by incorporating waterworks sludge (WWS) into cement mortar was carried out. The chemical composition, compressive strength and other physicochemical properties of the CMWWS cube specimens were determined using field emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD) and Fourier transform-infrared spectroscopy (FTIR). The major type of chemical components present in CMWWS was found to be Al and Fe. The increasing amount of WWS added to cement mortar resulted in the increasing of organic matter, urchin-like morphology and clear peak intensity. At the end of 28 days of curing, the soaking solution became strongly basic and CMWWS cube specimens leached out higher amount of heavy metals. The compressive strength of CMWWS increased up to a WWS percentage of 10%, and basic (pH > 7) curing solution was found to be better than water for curing purposes. It is concluded that solidification–stabilisation (S/S) technique is able to effectively reduce the leaching of heavy metals from the WWS and CMWWS containing up to 10% WWS can be used as construction material.     

Preparation of Superhydrophobic Polypropylene Membrane Using Dip-Coating Method: The Effects of Solution and Process Parameters

Superhydrophobic polypropylene hollow fiber membranes were prepared through two-step dip-coating process. The effects of solution and process parameters were investigated. It was found that polymer solution concentration and temperature were crucial parameters to obtain homogeneous coating. High hydrophobicity could be achieved by controlling the polymer solution concentration and drying temperature. Using methyl ethyl ketone as nonsolvent, the membrane surface roughness was increased, resulting in superhydrophobicity with high contact angle of 151.3°. The modified membrane still exhibited lower flux than unmodified membrane in water–oil separation due to porosity decrease. However, their water rejections were comparable.     

Structural,optical and electrical properties of Ce0.8Sm0.2-xErxO2-δ (x = 0–0.2) Co-doped ceria electrolytes

This study examined the effects of samarium and erbium co-doping on the structural, optical, and electrical properties of ceria (CeO₂). Ceramic (Ce_0.8Sm_0.2-xEr_xO_2-δ; x?=?0, 0.05, 0.10, 0.15, 0.20) electrolytes were synthesized via sol-gel assisted citric acid–nitrate combustion and calcined at 850?°C for 5?h. The calcined electrolytes possessed a cubic fluorite crystal structure without impure phases. The direct band gap of the calcined electrolytes increased as the erbium content increased and the lowest band gap was obtained for Ce_0.8Sm_0.2O_2-δ (SDC) electrolyte. The calcined electrolyte powders were subsequently pressed into cylindrical pellets by uniaxial die pressing, and the pellets were sintered at 1400?°C for 5?h. The sintered densities of the pellets were measured with Archimedes’ method. The relative density of Ce_0.8Sm_0.1Er_0.1O_2-δ co-doped ceria electrolyte was higher than those of singly doped ones, and these findings were further confirmed through field emission scanning electron microscopy. Electrochemical impedance spectroscopy indicated that the conductivity of erbium-doped ceria increased as the samarium content increased. The maximum total ionic conductivity was observed in Ce_0.8Sm_0.1Er_0.1O_2-δ co-doped electrolyte. However, the singly doped SDC electrolyte exhibited the highest ionic conductivity of 13.12 mS/cm and the lowest activation energy of 0.580?eV at 600?°C among all other Ce_0.8Sm_0.2-xEr_xO_2-δ co-doped ceria electrolytes.