Plant Extract Mediated Synthesis of Nickel Oxide Nanoparticles

The present study reports the successful synthesis of nickel oxide nanoparticles using Vernonia amygdalina plant leaf extracts as a chelating agent and nickel (II) chloride hexahydrate (NiCl2•6H2O) as precursor. The synthesized powder was gray black in color and annealed at 500 °C for 2 hours to obtain nickel oxide nanoparticles. Characterization techniques such as powder X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy were used to study the structure and morphology of the nanoparticles. Powder X-ray diffraction patterns revealed that nickel oxide nanoparticles with an average crystallite size of 17.86nm were synthesized. Scanning electron microscope images show that the nanoparticles have octahedral structure. Fourier transform infrared spectrophotometer analysis revealed that the strongest bond at 1094.8cm-1 corresponds to stretching vibration mode of Ni-O nanoparticles.

High sound absorption of polyester composites / fiber hemp / nanocellulose for automotive interior materials

Human health and environmental comfort are disturbed by the presence of noise, especially in cars, so that effective sound-absorbing materials are currently being developed. To answer the problem of noise in car interiors, polyester composite materials with local hemp fiber and nanocellulose reinforcement were developed. Natural fiber is biodegradable and renewable, and acts as an alternative to the use of synthetic fibers. The method used for the composite material manufacturing process was the casting method. The matrix of the composite material was polyester, while the reinforcement was a combination of local hemp fiber and nanocellulose fiber. Alkalization and non-alkalization processes have been carried out on hemp fiber. The composition of nanocellulose was 0%, 1%, and 3%. The characterization applied in this research were SEM test, FTIR test, sound transmission loss test, and density test. Optimal results were obtained on hemp fiber reinforced polyester composite materials without alkalization and without nanocellulose. Sound transmission loss (STL) was 61.91 dB up to 68.52 dB for the frequency range of 630 Hz to 125 Hz. The standard noise limit on 8-passenger passenger's four-wheeled vehicles is 77-80 dB. Based on the results obtained, the sound absorption is good. The density of this composite material was obtained at 0.989 gram/cm3. This composite material has the potential for developing dashboard material.

Numerical Modeling of Thermal Energy Storage of CHPs in Porous Concrete

Energy storage is essential in the modern age because fossil energy sources are running out, so there are a variety of ways to store energy, such as operating costs, energy consumption. The primary emissions and emissions, or all three, are reduced. In this paper, the heat energy storage method is used as sensible heat. The primary purpose of this study is to use inexpensive and available materials for energy storage. The heat source in this study is the CHP system exhaust gas selected for a 10-unit residential building. Thermal energy storage material is porous concrete that stores thermal energy in perceptible heat. The modeling of the system was also performed for the storage of thermal energy (charge and discharge process) by Schumann equations for fluid and solid storage in the porous medium, and the numerical solution of the equations was done by the characteristic method. For the fluid charge process of the CHP exhaust gases and air for the fluid discharge process, the porous concrete tank is assumed to be coated with mineral wool thermal insulation without loss of thermal energy. Heat transfer is only considered as one-dimensional heat transfer along the vertical axis of the tank, due to the porous solid storage environment, the conductive heat transfer in all dimensions of the tank is ignored. The thermocline property of the storage tank is essential for the numerical solution of the Schumann equations for the tank, with a charging time of 6 and a half hours and a discharge time of 5 hours.

Thermal Energy Storage for the Complex Energy Systems

Thermal energy systems (TES) systems contribute to the on-going process leading to greater integration between different energy systems in order to achieve cleaner and more sustainable use of energy resources. This paper reviews the current literature showing the development and deployment of TES-based solutions in power grid-connected systems. These solutions integrate the energy system to gain new potential for energy management, make better use of renewable energy (RES) resources, modernize energy system infrastructure, facilitate network operation practices that include energy conversion and service delivery. The network is cost-effective, facilitating. This paper provides a complementary look at other investigations into energy storage technologies and materials for TES and TES building applications and electrical energy storage aids for network applications. The main aspects discussed are the features, parameters, and models of TES systems, the deployment of TES in variable RES systems, small networks, multi-power networks, and emerging trends for TES applications.

Chitin, Chitosan, and Submicron-Sized Chitosan Particles Prepared from Scylla serrata Shells

Extraction of chitin from mud crab (Scylla serrata) shells, involving demineralization and deproteinization, and deacetylation of the extracted chitin to form chitosan were investigated. The mud crab chitin and chitosan were obtained with a good yield (16.8% and 84.7% based on dried weight basis). The physicochemical properties, functional groups, molecular weight, and degree of acetylation of the chitin and chitosan were characterized. The surface morphology, the orientation arrangement of polysaccharide strands, and crystallinity of the chitin and chitosan prepared from the mud crab shells were investigated. SEM, FTIR, and XRD analyses demonstrated that the chitin consists of micron-sized fibrils, belonging to α from with the crystallinity of 60.1%. The chitosan has a viscosity-average molecular weight of 6.83 kDa with the degree of acetylation being 9.6% and the crystallinity of 73.8%. The chitosan was successfully fabricated into submicron-sized particles using top-down ionotropic gelation, microwave, and microemulsion methods, employing sodium tripolyphosphate, potassium persulfate, and glutaraldehyde as reagents, respectively. Overall, the results indicated that the preparation of chitin, chitosan, and submicron-sized chitosan particles from mud crab shells could open the opportunity for the value-added seafood waste to be utilized in a wide range of practical applications.

Low Temperature Nickel Induced Crystallization of Amorphous Silicon Nanorods on Silicon and Glass Substrates

In this work, crystallization of amorphous silicon (a-Si) nanorods was done by metal induced crystallization (MIC) method at low temperature (500oC) suitable for circuit applications and low cost, disposable biosensors. The crystallization of a-Si nanorods was investigated by Raman and TEM methods. These data showed oriented crystallized Si nanorods have been obtained by metal induced crystallization (MIC) method on different substrates, which can be suitable for 3D integrated circuits, optical and electrochemical applications. This simple method can be used to produce silicon nanorod arrays with high quality suitable for nanoelectronic and optoelectronic applications.

Properties of Oriented Strandboard Produced Using Phenol-Formaldehyde Resin Synthesized with Bio-Oil of Lignocellulosic Wastes

The main objective of the present study was to modify phenol-formaldehyde (PF) resin by using bio-oil obtained by pyrolysis with and without alkali catalyst (potassium carbonate: K2CO3) (10 to 50 weight %) and determine technological properties oriented strandboard (OSB) panels produced using the modified PF resin formulations. The pine sawdust was used as a raw material of bio-oil. The chemical characterization of bio-oils was determined by GC-MS analysis. The OSB panels were produced with the bio-based PF resins and then their technological properties were determined. As the amount of potassium carbonate catalyst increased up to 20 wt% in the PF resin, 24-h thickness swelling of OSB panels decreased from 15.4 to 14.3%, but further increment in the potassium carbonate catalyst content increased the thickness swelling (22.8%). The IB strength of the OSB specimens with PF resin with 10 wt% bio-oil produced with catalyst or pyrolysis process was found the same (2.18 N/mm2) and it was higher than the reference value (1.97 N/mm2). As the amount of bio-oil was increased to 20 wt%, the difference in the IB values between treated OSB and reference OSB was negligible. However, above the 20 wt% bio oil, it was observed a decreasing trend in the IB values. The bending strength and bending modulus of the OSB specimens containing 20 wt% bio-oil were also found to be higher than those of the reference OSB specimens. It was concluded that the PF resin synthesized using bio-oil of (20 wt%) produced with and without alkali catalyst could be successfully used in the production of the OSB.

Morphological and Thermal Properties of Polystyrene Composite Reinforced with Biochar from Plantain Stalk Fibre

The advantages of natural fibres of synthetic fibres in the reinforcement of plastic composites have increased its use in diverse applications such as in the use of plant biochar in composite reinforcement. This research developed polystyrene composite development using biochar from plantain stalk fibre as filler. The composites obtained were analysed for their thermal and functional properties using Differential Scanning Calorimetry (DSC) and Fourier Transform Infra-Red Spectroscopy (FTIR) respectively. The composite with 30% filler was seen to have optimum thermal stability. The eco-friendliness of the composite gives a better solution to agro-waste disposal rather than burning.

A Programmable Proton Exchange Membrane Fuel Cell Emulator Based on a DC-DC Synchronous Buck Converter

In the development of fuel cell (FC) systems and related control technologies, it is convenient to employ FC emulators instead of using real FC systems for the testing of various FC characteristic parameters and operating conditions. This paper proposes a low-cost, fast-response, and programmable proton exchange membrane FC (PEMFC) hardware emulator based on a two-switch DC-DC synchronous buck converter and a digital signal processor (DSP) acting as a kernel controller. The V-I characteristics and control signals of the emulated PEMFC are determined through system analysis, modeling, and digitalization of the PEMFC model. The developed PEMFC model is then used to construct a programmable user-interface module through C programming. The programmable digital module can be directly embedded into the DSP for simulation studies and experimental tests on various hardware integrated implementations of FCs. Results obtained from simulations and hardware tests are in good consistent with each other and both prove the correctness and effectiveness of the developed converter based PEMFC emulator.

Effects of Substrate Type on the Morphology and Optical Properties of ZnO Nanorods Grown via Chemical Bath Deposition

In this study, zinc oxide nanorods (ZnO NRs) were prepared through chemical bath deposition using glass and fluorine-doped tin oxide (FTO) substrates, and their crystalline structure was investigated through X-ray diffraction. Results showed that the prepared ZnO NRs had wurtzite structure and grew along the [002] orientation, and ZnO NRs grown on the FTO substrate was more crystalline than those grown on the glass substrate. Field-emission scanning electron microscopy images showed that the glass sample had rod-like morphology and uniform distribution with 95 nm diameter and average length of approximately 980 nm, whereas the FTO-coated glass had 110 nm diameter and average length of approximately 1000 nm. The direct transition optica1 band gaps of the glass and FTO-coated glass samples were 3.28 and 3.97 eV, respectively.