Impact of innovative nanoadditives on biodigesters microbiome.

Nanoparticles (NPs) supplementation to biodigesters improves the digestibility of biowaste and the generation of biogas. This study investigates the impact of innovative nanoadditives on the microbiome of biodigesters. Fresh cow manure was anaerobically incubated in a water bath under mesophilic conditions for 30 days. Three different NPs (zinc ferrite, zinc ferrite with 10% carbon nanotubes and zinc ferrite with 10% C76 fullerene) were separately supplemented to the biodigesters at the beginning of the incubation period. Methane and hydrogen production were monitored daily. Manure samples were collected from the digesters at different time points and the microbial communities inside the biodigesters were investigated via real-time PCR and 16 S rRNA gene amplicon-sequencing. The results indicate that zinc ferrite NPs enhanced biogas production the most. The microbial community was significantly affected by NPs addition in terms of archaeal and bacterial 16 S rRNAgene copy numbers. The three ZF formulations NPs augmented the abundance of members within the hydrogenotrophic methanogenic phyla Methanobacteriaceae. While Methanomassiliicoccacaea were enriched in ZF/C76 supplemented biodigester due to a significant increase in hydrogen partial pressure, probably caused by the enrichment of Spirochaetaceae (genus Treponema). Overall, NPs supplementation significantly enriched acetate-producing members within Hungateiclostridiaceae in ZF/CNTs, Dysgonomonadaceae in ZF and Spirochaetaceae ZF/C76 biodigesters.

Experimental study and theoretical prediction of mechanical properties of ultra-high-performance concrete incorporated with nanorice husk ash burning at different temperature treatments.

This research aimed to investigate the effect of nanorice husk ash (NRHA) prepared using different thermal treatment methods on ultra-high-performance concrete (UHPC) behaviour. NRHA was prepared by two methods: (1) burning for 3 h at 300, 500, 700 and 900 °C and (2) burning for different durations (9, 7, 5 and 3 h) at 300, 500, 700 and 900 °C. NRHA was added to UHPC to make 25 mixtures with three dosages (1%, 3% and 5%). Density, compressive strength, tensile strength, flexure strength and ultrasonic pulse velocity tests were performed at the experimental level. Moreover, full microstructure analysis, including X-ray diffractometry, Brunauer-Emmett-Teller surface area analysis, thermogravimetric analysis, scanning electron microscopy and energy-dispersive X-ray spectroscopy, was performed. The best performances in in the first method (constant duration, different temperatures) were obtained by 1% NRHA burned at 900 °C with 12.5% compressive strength and 1% NRHA burned at 700 °C with increased ratio (10%). Moreover, the best performance in the second method (different burning durations and temperatures) was obtained by 3% NRHA with a ratio of 22.5% at 700 °C for 5 h. Burning rice husk ash improved the compressive strength. It also remarkably improved the splitting tensile strength and flexure strength by 32% and 47%, respectively, at 3% NRHA treated at 700 °C for 3 h. The microstructural analysis showed the efficient role of NRHA in the compactness of concrete sections. It improved the formation of new calcium silicate hydrate gel; decreased the cracks, voids, CaCO3 and Ca(OH)2; and increased the Ca/Si composition. The obtained experimental results were used to build an artificial neural network (ANN) to predict UHPC properties. The ANN model was used as a validation tool to determine the correlation between results. Results showed a remarkable improvement in the mechanical properties of UHPC incorporating NRHA for all mixtures. The ANN model indicated a reliable correlation between input and output variables. The R2 values for the training, validation and testing steps were all 0.99.

Supercapattery electrode materials by Design: Plasma-induced defect engineering of bimetallic oxyphosphides for energy storage.

Although transition metal hydroxides are promising candidates as advanced supercapattery materials, they suffer from poor electrical conductivity. In this regard, previous studies have typically analyzed separately the impacts of defect engineering at the atomic level and the conversion of hydroxides to phosphides on conductivity and the overall electrochemical performance. Meanwhile, this paper uniquely studies the aforementioned methodologies simultaneously inside an all-in-one simple plasma treatment for nickel cobalt carbonate hydroxide, examines the effect of altering the nickel-to-cobalt ratio in the binder-free defect-engineered bimetallic Ni-Co system, and estimates the respective quantum capacitance. Results show that the concurrent defect-engineering and phosphidation of nickel cobalt carbonate hydroxide boost the amount of effective redox and adsorption sites and increase the conductivity and the operating potential window. The electrodes exhibit ultra-high-capacity of 1462 C g-1, which is among the highest reported for a nickel-cobalt phosphide/phosphate system. Besides, a hybrid supercapacitor device was fabricated that can deliver an energy density of 48 Wh kg-1 at a power density of 800 W kg-1, along with an outstanding cycling performance, using the best performing electrode as the positive electrode and graphene hydrogel as the negative electrode. These results outperform most Ni-Co-based materials, demonstrating that plasma-assisted defect-engineered Ni-Co-P/POx is a promising material for use to assemble efficient energy storage devices.

Binder-Free Electrospun Ni-Mn-O Nanofibers Embedded in Carbon Shells with Ultrahigh Energy and Power Densities for Highly Stable Next-Generation Energy Storage Devices.

We demonstrate the fabrication of binder-free electrospun nickel-manganese oxides embedded into carbon-shell fibrous electrodes. The morphological and structural properties of the assembled electrode materials were elucidated by high-resolution transmission electron microscopy (HR-TEM), field-emission scanning electron microscopy, and glancing-angle X-ray diffraction. The fibrous structure of the electrodes was retained even after annealing at high temperatures. The X-ray photoelectron spectroscopy and HR-TEM analyses revealed the formation of nickel and manganese oxides in multiple oxidation states (Ni2+, Ni3+, Mn2+, Mn3+, and Mn4+) embedded in the carbon shell. The embedded nickel-manganese oxides into the carbon matrix fibrous electrodes exhibit an excellent capacitance (1082 F/g) in 1 M K2SO4 at 1 A/g and possess a high rate capability of 73% at 5 A/g. The high rate capability and capacitance can be attributed to the presence of carbon cross-linked channels, the binder-free nature of the electrodes, and various oxidation states of the Ni-Mn oxides. The asymmetric supercapacitor device constructed of the as-fabricated nanofibers and the bio-derived microporous carbon as the positive and negative electrodes, respectively, sustains up to 1.9 V with a high specific capacitance at 1.5 A/g of 108 F/g. The nanofibrous//bio-derived device exhibits an outstanding specific energy of 54.2 W h/kg with a high specific power of 1425 W/kg. Interestingly, the tested device maintains a high capacitive retention of 92% upon cycling over 10,000 charging/discharging cycles.

Mechanistic effects of blending formic acid with ethanol on Pd activity towards formic acid oxidation in acidic media.

The direct formic acid fuel cell (DFAFC) is one of the most promising direct liquid fuel cells. Pd is the most active catalyst towards formic oxidation, however, it suffers from CO-like poisoning and instability in acidic media. Blending formic acid with ethanol is known to synergistically enhance the Pt catalytic activity of Pt. However, it has not been studied in the case of Pd. In this study, ethanol/formic acid blends were tested, aiming at understanding the effect of ethanol on the formic acid oxidation mechanism at Pd and how the direct and indirect pathways could be affected. The blends consisted of different formic acid (up to 4 M) and ethanol (up to 0.5 M) concentrations. The catalytic activity of a 40% Pd/C catalyst was tested in 0.1 M H2SO4 + XFA + YEtOH using cyclic voltammetry, while the catalyst resistance to poisoning in the presence and absence of ethanol was tested using chronopotentiometry. The use of these blends is found to not only eliminate the indirect pathway but also slowly decrease the direct pathway activity too. That is believed to be due to the different ethanol adsorption orientations at different potentials. This study should open the door for further studying the oxidation of FA/ethanol blends using different pHs and different Pd-based catalysts.

Innovative nanocomposite formulations for enhancing biogas and biofertilizers production from anaerobic digestion of organic waste.

Herein, the design of nanocomposite (NC) formulations that consist of metal enzyme cofactors, highly conductive carbon materials, DIET activators, to boost AD biogas production from anaerobically incubated cattle manure are investigated and discussed. Three different NC formulations were designed and synthesized: zinc ferrite (ZnFe), ZnFe with 10% carbon nanotubes (ZFCNTs), and zinc ferrite with 10% C76 fullerene (ZFC76). The structure and morphology of the nano-additives were investigated via x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive x-ray (EDX), and transmission electron microscopy (TEM). NCs were supplemented to lab-scale biodigesters containing organic slurry. Biogas production was monitored daily and compared to blank biodigesters for 50 days. The maximum methane enhancement was obtained for ZnFe, which promoted methane production to 185.3%. ZFCNTs and ZFC76 showed a positive impact on the hydraulic retention time and enhanced methane production to 162% and 145.9%, respectively compared to the blank reactors.

Recent advances in the use of TiO2 nanotube powder in biological, environmental, and energy applications.

The use of titanium dioxide nanotubes in the powder form (TNTP) has been a hot topic for the past few decades in many applications. The high quality of the fabricated TNTP by various synthetic routes may meet the required threshold of performance in a plethora of fields such as drug delivery, sensors, supercapacitors, and photocatalytic applications. This review briefly discusses the synthesis techniques of TNTP, their use in various applications, and future perspectives to expand their use in more applications.

Smart bi-metallic perovskite nanofibers as selective and reusable sensors of nano-level concentrations of non-steroidal anti-inflammatory drugs.

A strategy for trace-level carbon-based electrochemical sensors is investigated via exploring the interesting properties of BaNb2O6 nanofibers (NFs). Utilizing adsorptive stripping square wave voltammetry (ASSWV), an electrochemical sensing platform was developed based on BaNb2O6 nanofibers-modified carbon paste electrode (CPE) for the sensitive detection of lornoxicam (LOR). Different techniques were used to characterize the fabricated BaNb2O6 perovskite NFs. The obtained data show the feasibility to electro-oxidize LOR and paracetamol (PAR) on the surface of the fabricated sensor. The amount of nanofiber and testing conditions were optimized using response surface methodology and ASSWV technique. The optimized BaNb2O6/CPE sensor exhibits low detection limit of 6.39 × 10-10 mol L-1, even in the presence of the co-formulated drug paracetamol (PAR). The sensor was successfully applied for biological applications.

3D spongy graphene-modified screen-printed sensors for the voltammetric determination of the narcotic drug codeine.

Adenine-functionalized spongy graphene (FSG) composite, fabricated via a facile and green synthetic method, has been explored as a potential electrocatalyst toward the electroanalytical sensing of codeine phosphate (COD). The synthesized composite is characterized using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray powder diffraction, UV-vis absorption spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy (HRTEM), and thermogravimetric analysis. The FSG was electrically wired via modification upon screen-printed (macro electrode) sensors, which behave as a hybrid electrode material for the sensitive and selective codeine phosphate (COD) determination in the presence of paracetamol (PAR) and caffeine (CAF). The FSG- modified sensor showed an excellent electrocatalytic response towards the sensing of COD with a wide linear response range of 2.0 × 10-8-2.0 × 10-4M and a detection limit (LOD) of 5.8 × 10-9M, indicating its potential for the sensing of COD in clinical samples and pharmaceutical formulations.

Propagation of ultrasonic waves through demineralized cancellous bone.

Ultrasonic velocity is determined in a number of bovine cancellous (spongy) bone samples by using a double-probe-through-transmission ultrasonic pulse technique. The ultrasonic velocity, total mineral content, bone density, and solid volume fraction of the specimen were determined. The relation between fast velocity and each of the other parameters was examined to explore the best correlation using linear, logarithmic, power, and exponential relationships. There is a strong positive relationship between ultrasonic velocity and each of the other parameters. The exponential model fits the data better than the linear model, logarithmic model, and power model. Biot's theory also is used to predict the velocity of ultrasound in the demineralized bone. It is shown that the transmission of ultrasonic pulses in the cancellous bone samples can be adequately described using Biot's theory. The different parameters occurring in the Biot theory have been measured independently, and the calculation has been compared with measured velocity of water-saturated bone samples. The correlation coefficients for regression analysis between the experimental velocities and those predicted by Biot's theory are greater than 0.86.