2020, Vol. 5, No. 3
Display Method:
2020, 5(3): 143-162.
doi: 10.1016/j.jobab.2020.07.001
Abstract:
As a staple food for much of the world, rice production is widespread. However, it also results in the generation of large quantities of non-food biomass, primarily in the form of straw and husks. Although they have been little utilized and much rice straw is still simply burned, these lignocellulosic materials potentially have considerable values. This review considers the composition of rice straw and husks, the various processes involved in the production of valuable products, and a range of uses to which they can be put. These include agricultural amendments, energy production, environmental adsorbents, construction materials, and various speciality products.
As a staple food for much of the world, rice production is widespread. However, it also results in the generation of large quantities of non-food biomass, primarily in the form of straw and husks. Although they have been little utilized and much rice straw is still simply burned, these lignocellulosic materials potentially have considerable values. This review considers the composition of rice straw and husks, the various processes involved in the production of valuable products, and a range of uses to which they can be put. These include agricultural amendments, energy production, environmental adsorbents, construction materials, and various speciality products.
2020, 5(3): 163-179.
doi: 10.1016/j.jobab.2020.07.002
Abstract:
Lignin, as a major by-product of pulp and paper industry, has attracted extensive interest for the preparation of high value-added products, due to the merits of abundant, sustainable, inexpensive, and unique functional groups. This review focuses on the strategies to develop high performance polyurethane (PU) materials from lignin on the basis of main reports, in which lignin was used not only as macromonomer to substitute petroleum-based polyols, but also as blending filler for PU industry. Pre-treatment approaches, especially lignin fractions extracted with various solvents and chemical modifications, e.g., depolymerization, hydroxyalkylation, dealkylation, and esterication, were widely explored to enable lignin more reactive and available to synthesize PU products. In addition, lignin/PU blends were also prepared to fulfill industrial demand. With adjustment of lignin structure, the PU formulation, and synthesis procedures, various lignin-based PU products with advanced properties and a higher bio-substitution ratio have been developed, demonstrating the potential industrial application of lignin for high value-added sustainable materials.
Lignin, as a major by-product of pulp and paper industry, has attracted extensive interest for the preparation of high value-added products, due to the merits of abundant, sustainable, inexpensive, and unique functional groups. This review focuses on the strategies to develop high performance polyurethane (PU) materials from lignin on the basis of main reports, in which lignin was used not only as macromonomer to substitute petroleum-based polyols, but also as blending filler for PU industry. Pre-treatment approaches, especially lignin fractions extracted with various solvents and chemical modifications, e.g., depolymerization, hydroxyalkylation, dealkylation, and esterication, were widely explored to enable lignin more reactive and available to synthesize PU products. In addition, lignin/PU blends were also prepared to fulfill industrial demand. With adjustment of lignin structure, the PU formulation, and synthesis procedures, various lignin-based PU products with advanced properties and a higher bio-substitution ratio have been developed, demonstrating the potential industrial application of lignin for high value-added sustainable materials.
2020, 5(3): 180-185.
doi: 10.1016/j.jobab.2020.07.003
Abstract:
Tamarind fruit shell powder (TFSP) with particle size of < 50 μm (obtained from cleaned tamarind fruit shells) was modified with in situ generated copper nanoparticles (CuNPs) by simple one step hydrothermal method. The modified TFSP was characterized by scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and antibacterial tests. The generated stable CuNPs on the surface of the modified TFSP were spherical in shape with an average size of 88 nm. The FT-IR spectroscopy analysis indicated the involvement of the functional groups of the TFSP in the generation and stabilization of the CuNPs. The XRD analysis indicated the presence of both CuNPs and Cu2O nanoparticles in the modified TFSP. The thermal analysis indicated the presence of 5.6 wt% of copper nanoparticles as calculated from the difference of residual char content between the unmodified and modified TFSP. The modified TFSP with in situ generated CuNPs exhibited obvious antibacterial activity against both the Gram negative and Gram positive bacteria and hence can be considered as low cost filler in the preparation of antibacterial polymer hybrid nanocomposites for packaging and medical applications.
Tamarind fruit shell powder (TFSP) with particle size of < 50 μm (obtained from cleaned tamarind fruit shells) was modified with in situ generated copper nanoparticles (CuNPs) by simple one step hydrothermal method. The modified TFSP was characterized by scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and antibacterial tests. The generated stable CuNPs on the surface of the modified TFSP were spherical in shape with an average size of 88 nm. The FT-IR spectroscopy analysis indicated the involvement of the functional groups of the TFSP in the generation and stabilization of the CuNPs. The XRD analysis indicated the presence of both CuNPs and Cu2O nanoparticles in the modified TFSP. The thermal analysis indicated the presence of 5.6 wt% of copper nanoparticles as calculated from the difference of residual char content between the unmodified and modified TFSP. The modified TFSP with in situ generated CuNPs exhibited obvious antibacterial activity against both the Gram negative and Gram positive bacteria and hence can be considered as low cost filler in the preparation of antibacterial polymer hybrid nanocomposites for packaging and medical applications.
2020, 5(3): 186-195.
doi: 10.1016/j.jobab.2020.00.004
Abstract:
A test equipment was developed, which allows for real time observation of the deformation behaviour of wood cellular structure under a compression load applied in radial direction. Compression tests were performed on jack pine (Pinus banksians) and balsam poplar (Populus balsamifera) specimens to explore the relationship between the yield stress and the first failure occurring in wood cell layers during radial compression. The microstructural changes for P. banksians and P. balsamifera wood below and above the yield point were analyzed. The study results showed that for P. banksians the first failure of wood cells occurred at the first earlywood layer, while for P. balsamifera it occurred at the layer with the largest vessels. The first failure of wood cell layer for each species tested was found to correspond to the yield point on the stress-strain curve. A new method of determining the yield stress for wood specimens under radial compression was developed.
A test equipment was developed, which allows for real time observation of the deformation behaviour of wood cellular structure under a compression load applied in radial direction. Compression tests were performed on jack pine (Pinus banksians) and balsam poplar (Populus balsamifera) specimens to explore the relationship between the yield stress and the first failure occurring in wood cell layers during radial compression. The microstructural changes for P. banksians and P. balsamifera wood below and above the yield point were analyzed. The study results showed that for P. banksians the first failure of wood cells occurred at the first earlywood layer, while for P. balsamifera it occurred at the layer with the largest vessels. The first failure of wood cell layer for each species tested was found to correspond to the yield point on the stress-strain curve. A new method of determining the yield stress for wood specimens under radial compression was developed.
2020, 5(3): 196-203.
doi: 10.1016/j.jobab.2020.07.005
Abstract:
In this study, a model for prediction of lignocellulose components of agricultural residues has been developed with Fourier Transformed Near Infrared (FT-NIR) spectroscopy data. Two calibration techniques (Principal Component Regression (PCR) and Partial Least Square Regression (PLSR)) were assessed for prediction of lignin, holocellulose, α-cellulose, pentosan and ash, and found the PLSR better for lignin, holocellulose and α-cellulose. The PCR also produced better results for quantification of pentosan and ash. Spectral range (7000-5000cm-1) showed more informative than other parts of the spectral data. The PLSR showed maximum value of R2 (R2=0.91%) for prediction of holocellulose. For the prediction of pentosan, the PCR was better (R2=0.68%). The PCR also showed better results (R2=86%) for quantification of ash. To determine amount of lignin, the PLSR was the best (R2=0.83%) when the spectral data were de-trained and smoothed with Savitzky-Golay (S-G) filtering simultaneously. For prediction of α-cellulose, the PLSR was the best model (R2=0.94%) when the data were pretreated with mean normalization. Considering the best alternatives inNear Infrared (NIR) data preprocessing and calibration techniques, methods for quantification of lignocellulose components of agricultural residues have been developed which is rapid, cost effective, and less chemical intensive and easily usable in pulp and paper industries and pulp testing laboratories.
In this study, a model for prediction of lignocellulose components of agricultural residues has been developed with Fourier Transformed Near Infrared (FT-NIR) spectroscopy data. Two calibration techniques (Principal Component Regression (PCR) and Partial Least Square Regression (PLSR)) were assessed for prediction of lignin, holocellulose, α-cellulose, pentosan and ash, and found the PLSR better for lignin, holocellulose and α-cellulose. The PCR also produced better results for quantification of pentosan and ash. Spectral range (7000-5000cm-1) showed more informative than other parts of the spectral data. The PLSR showed maximum value of R2 (R2=0.91%) for prediction of holocellulose. For the prediction of pentosan, the PCR was better (R2=0.68%). The PCR also showed better results (R2=86%) for quantification of ash. To determine amount of lignin, the PLSR was the best (R2=0.83%) when the spectral data were de-trained and smoothed with Savitzky-Golay (S-G) filtering simultaneously. For prediction of α-cellulose, the PLSR was the best model (R2=0.94%) when the data were pretreated with mean normalization. Considering the best alternatives inNear Infrared (NIR) data preprocessing and calibration techniques, methods for quantification of lignocellulose components of agricultural residues have been developed which is rapid, cost effective, and less chemical intensive and easily usable in pulp and paper industries and pulp testing laboratories.
2020, 5(3): 204-210.
doi: 10.1016/j.jobab.2020.07.006
Abstract:
Lignin is one of the major contents of lignocellulose and can be used as feedstock for adsorbent materials for wastewater treatment. Here, a lignin-poly(N-methylaniline)-graphene oxide (lignin-PNMA-rGO) hydrogel has been prepared by a two-step method, microspheres of lignin-PNMA was synthesis by the polymerization of NMA monomer in the presence of lignin in aqueous solution, and then they were encapsulated by the as-prepared reduced graphene oxide (GO) hydrogel via a reduction induced self-assembly of the GO nanosheets.The scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and UV-Vis studies have been carried out and revealed that the formation of the 3D porous nanocomposite hydrogel with multilevel structures and sufficient active sites. The lignin-PNMA-rGO adsorbent exhibited high adsorption capacity for both organic dye methylene blue (MB, 201.7 mg/g) and Pb2+ ion (753.5 mg/g). The new lignin-based adsorbent is a low-cost, environmentally benign, which is an attractive adsorbent for wastewater treatment.
Lignin is one of the major contents of lignocellulose and can be used as feedstock for adsorbent materials for wastewater treatment. Here, a lignin-poly(N-methylaniline)-graphene oxide (lignin-PNMA-rGO) hydrogel has been prepared by a two-step method, microspheres of lignin-PNMA was synthesis by the polymerization of NMA monomer in the presence of lignin in aqueous solution, and then they were encapsulated by the as-prepared reduced graphene oxide (GO) hydrogel via a reduction induced self-assembly of the GO nanosheets.The scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and UV-Vis studies have been carried out and revealed that the formation of the 3D porous nanocomposite hydrogel with multilevel structures and sufficient active sites. The lignin-PNMA-rGO adsorbent exhibited high adsorption capacity for both organic dye methylene blue (MB, 201.7 mg/g) and Pb2+ ion (753.5 mg/g). The new lignin-based adsorbent is a low-cost, environmentally benign, which is an attractive adsorbent for wastewater treatment.
Numerical investigation of thermo-physical properties of non-newtonian fliud in a modelled intestine
2020, 5(3): 211-221.
doi: 10.1016/j.jobab.2020.07.007
Abstract:
Several kinds of researches have been conducted on peristaltic flow of non-Newtonian fluid in modelled oesophagus, stomach and intestine. However, further investigation is still needed especially in the area of mechanical shear stress, the influence of inlet temperature and velocity, Nutsselt number and the history of strain rates experienced by fluid particles. This study presents the numerical investigation of thermo-physical properties of non-Newtonian fluid in a modelled intestine. The properties investigated were fluid temperature, velocity, Nutsselt number and wall shear stress. Numerical simulation was performed by solving 3D Navier-Stokes and continuity equations. The intestinal model was drawn by using Autodesk Inventor 2017 while the numerical investigation was conducted by using ANSYS FLUENT 16.0. The Computation Fluid Dynamics solver employs the Finite Element Method (FEM) to discretize the governing equations. Chyme, Hibiscus Sabdariffa Roselle (Sobo), Soymilk (Soya) and Pap (Ogi) were the working fluids used for the investigation. Analyses of the results showed that the variation of fluid temperature and heat transfer with axial position across the length of intestinal model were not significantly influenced by the variation of the inlet velocity. Expansion of the model about the pulsating part enhanced heat transfer and nutrient delivery to the intestinal walls. Variation of the inlet velocity did not affect the average Nutsselt number. Chyme and Sobo had the highest and lowest Nutsselt number, respectively. Sobo displayed the best fluid properties considering flow behaviour while Soya displayed the best properties for thermal history. The results presented in this study are of countless importance in medical, paramedical, engineering applications, thermoregulation system, thermotherapy, and biomedical disciplines, where analyses and investigation of gastrointestinal tract history can be understudied.
Several kinds of researches have been conducted on peristaltic flow of non-Newtonian fluid in modelled oesophagus, stomach and intestine. However, further investigation is still needed especially in the area of mechanical shear stress, the influence of inlet temperature and velocity, Nutsselt number and the history of strain rates experienced by fluid particles. This study presents the numerical investigation of thermo-physical properties of non-Newtonian fluid in a modelled intestine. The properties investigated were fluid temperature, velocity, Nutsselt number and wall shear stress. Numerical simulation was performed by solving 3D Navier-Stokes and continuity equations. The intestinal model was drawn by using Autodesk Inventor 2017 while the numerical investigation was conducted by using ANSYS FLUENT 16.0. The Computation Fluid Dynamics solver employs the Finite Element Method (FEM) to discretize the governing equations. Chyme, Hibiscus Sabdariffa Roselle (Sobo), Soymilk (Soya) and Pap (Ogi) were the working fluids used for the investigation. Analyses of the results showed that the variation of fluid temperature and heat transfer with axial position across the length of intestinal model were not significantly influenced by the variation of the inlet velocity. Expansion of the model about the pulsating part enhanced heat transfer and nutrient delivery to the intestinal walls. Variation of the inlet velocity did not affect the average Nutsselt number. Chyme and Sobo had the highest and lowest Nutsselt number, respectively. Sobo displayed the best fluid properties considering flow behaviour while Soya displayed the best properties for thermal history. The results presented in this study are of countless importance in medical, paramedical, engineering applications, thermoregulation system, thermotherapy, and biomedical disciplines, where analyses and investigation of gastrointestinal tract history can be understudied.
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