2021, Vol. 6, No. 3
Over the last 15 years, significant number of reports on transparent paper and transparent wood appeared in the literature. The light scattering data or transmission data are often given to describe the optical performance of the material. In addition, the data also contains structural information that can be further analyzed based on scattering theory. Some of the data are re-analyzed herein from structural analysis point of view related to the scattering phenomena. Quantitative analysis on the wavelength dependent optical density of nanopaper suggested that the scatterers are not isolated voids or microfibrils but rather large submicrometric and structural domains. Angular dependence of transparent wood scattering suggests the scattering units of a few micrometers such as cell wall are at the origin of high haze.
The global demand for textile products is rapidly increasing due to population growth, rising living standards, economic development, and fast fashion trends. Ethiopian growth and transformation plan (GTP) gives high priorities for the textile and apparel sectors to transform its agriculturally led economy to an industrial-based economy. To achieve this, the number of textile and apparel industries is rapidly expanding. However, the rapid growth in textile industry is generating mountains and mountains of by-products. In this review, possible applications of cotton stalk and cotton ginning waste in a variety of technologies and products are discussed in Ethiopian context. The finding of this study shows that Ethiopian current cotton cultivating area is about 80 000 hm2, even though the country has a potential of about 3 000 810 hm2 land for cotton cultivation. From the current cultivated area, more than 240 000 t of cotton stalk and 9240 t of cotton ginning trash have been generated as a by-product. But only a very little portion of the cotton stalk is being used as a raw fuel for household purposes and a small portion of cotton ginning trash is used for animal feed. Therefore, these underutilized lignocellulosic biomasses can be used as raw materials for producing different high-value biomaterials and thus country can perceive an economic and environmental benefit. A closer look at the structure and composition of the by-products shows that the whole part of cotton stalk and ginning waste can be used as a source of cellulose which can be exploited for conversion into a number of high-value biomaterials. Thus, conversion of the waste into valuable products can make cotton stalk and ginning by-products an attractive raw material for the production of high value bio-products.
A one-pot synthesis method was conceptualized and implemented to develop green carbon-based nanocomposites working as biosensors. Porphyrin was synthesized to adorn the surface of nanocomposites making them highly sensitive for giving rise to π-π interactions between the genetic materials, proteins and porphyrin rings. The hydrogen bond formed between the proteins (analytes) and the nitrogen in the porphyrin structure as well as the surface hydroxyl groups was equally probable. In this context, different forms of porphyrins were incorporated to explore the interrelationship between the surface morphology and the ability of detection of genetic material and/or proteins by the aid of the synthesized structures. This phenomenon was conceptualized to optimize the interactions between the biomolecules and the substrate by reaching significant biosensor application in the presence of Anti-cas9 protein and sgRNA (concentration changed between 10 and 500 n mol/L). Almost full quenching of fluorescence emission was observed after addition of 300 n mol/L of Anti-cas9 protein and 250 n mol/L of sgRNA. Surprisingly, CoNi2S4 provided 12%–29% cytotoxicity in both HEK-293 and PC12 cell lines.
The current article covers the production of chitosan (CS) from shells of shrimp waste and its utilization in the preparation of eco-friendly imprinting and non-imprinting composites with Ulva lactuca algae (Alg). These bio-composites namely (Imp-Alg-25wt% CS) and (NImp-Alg-25wt% CS) were used for removal of Cd(II) ions. Fourier transform infrared (FT-IR) spectra, scanning electron microscope (SEM) equipped with electron dispersive X-ray (EDX), X-ray diffraction (XRD), and elemental analysis measurements were performed to characterize these bio-composites sorbents. The highest adsorption of these sorbents towards Cd(II) ions was determined as a function of solutions pH, contact time, Cd(II) ion concentration, beads dose, and temperature. The equilibrium experimental data were treated using various mathematical isotherm and kinetic models to approve the maximum bio-sorption capacities of NImp-Alg-25wt% CS and Imp-Alg-25wt% CS (in mg/g). The results exhibited that Imp-Alg-25wt% CS gave higher removal capacity than NImp-Alg-25wt% CS at the same optimum parameters. Pseudo-2nd order dynamic and Langmuir isotherm models were well described in these biosorption processes. Thermodynamically, the removal behavior of Cd(II) using both bio-composites was spontaneous at room temperature. The reusability of the sorbents, NImp-Alg-25wt% CS and Imp-Alg-25wt% CS, showed three cycles. In addition, comparative study was also conducted for Cd(II) removal onto some reported sorbents.
Novel organic-inorganic hybrids were synthesized by using HfCl4 and organic ligand 1H-pyrrole-2, 5-dicarboxylic acid (PDCA) via a simple hydrothermal method. The as-prepared Hf-PDCA were characterized by various techniques, such as electron microscope, N2 adsorption/desorption, and X-ray photoelectron spectroscopy. Among them, the porous and nitrogen-containing Hf-PDCA as heterogeneous acid/base bifunctional catalyst was then applied to the catalytic hydrogenation of furfural to produce furfuryl alcohol (FFA). It exhibited excellent catalytic performance, with high conversion (98.8%) and selectivity (98.5%) by using 2-propanol as hydrogen source under a relatively mild condition. Moreover, the Hf-PDCA has strong stability and durability, and can be recovered after the catalyst reaction. In addition, the Hf-PDCA as catalyst can be extended to fabricate corresponding alcohols by catalytic conversion of other biomass derived aldehydes.
The present investigation reports the soxhlet assisted solvent extraction technique to derive the oil from seeds of the rain tree. The optimization of the factors affecting the extraction process has been carried out by Response Surface Methodology (RSM) technique, and a Box-Behnken Design (BBD) consisting of three process variables has been developed to optimize the yield of oil. Using the RSM technique, the predicted optimum oil yield of 11.15% at an optimized condition of powder weight of 20 g, volume of solvent of 380 mL, and extraction time of 6 h. The physiochemical properties of the oil showed liquid greenish-yellow with 0.88, 1.473 of specific gravity and refractive index, respectively. Similarly, the moisture content, free fatty acid, acid value, saponification value, iodine value, and peroxide value were found to be 0.16%, 13.615, 27.23, 187.1 mg KOH per g oil, 65.8 g I2 per 100 g, and 4.02 meq O2 per kg, respectively. From the obtained results, it was found that the extracted oil could be used for various applications.
In order to meet the objective requirements of the safety and comfort of the modern lightweight timber floors, and strengthen the research on the coupling performance of the lightweight timber floors vibration characteristics and the building comfort, this article discusses the floor of a two-story prefabricated lightweight timber building demonstration house. In this paper, the floor structure of a two-story light-weight wooden house has been carried out on structural calculation modal and experimental modal, static uniform load and concentrated load de flection value testing. The evaluation of the deflection value of the floor structure, the mode shape, the coupling of the fundamental frequency mode parameters, and the vibration comfort were also studied. The results show that the fundamental frequency simulation value, one-way modal test value and two-way modal test value of the floor structure all meet the requirements of BS-6472 (BS6472-1: 2008). That is, the floor structure is not lower than 8 Hz design requirements, and meets the frequency of BS-6472(BS6472-1: 2008). The weighted root mean square acceleration is lower than the requirement of 0.45 m/s2; the first three natural frequencies of the floor structure calculated by the finite element simulation are 16.413, 31.847 and 48.921 Hz, and the fundamental frequency mode is the bending vibration in the length and width directions. The second order is the bending mode in the length direction, and the third order is the bending mode in the width direction. The fundamental frequency of the two-way modal test of the floor structure is the first-order bending mode in the X direction; and the second-order natural frequency is the second-order bending vibration shape in the X direction. when the uniform load is mainly the weight of floor own, the simulated maximum deflection value is 1.0658 mm; the simulation is performed according to the standard value of 0.566 kN/m for the uniform load of the floor design, and the simulation is the largest. The maximum deflection value of the simulated floor is 1.47383 mm at its midpoint, which meets the requirements of National Building Code of Canada-2015 (NBCC). The maximum deflection limit of the light wood structure floor system is lower than 3 m and the maximum deflection limit is 2 mm; the six deflection value test lines simulated under a concentrated load of 1 kN all present a parabolic distribution and are symmetrical. The above results has engineering application value for promoting the research on the vibration characteristics of the fabricated lightweight timber floors structure and its optimization design.
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