Correction to the Fukuda-Kawata Young's modulus theory and the Fukuda-Chou strength theory for short fibre-reinforced composite materials

The theories for modulus and strength of short fibre-reinforced composite materials are based on the calculation of the force sustained by fibres crossing an arbitrary line perpendicular to the applied load, called the scan line, in a thin, rectangular specimen. The widely referenced Fukuda-Kawata modulus theory and the Fukuda-Chou strength theory are based on an apparently incorrect procedure for the calculation of the force sustained by the fibres crossing the scan line. The error is explained in detail by comparing the Fukuda-Kawata modulus theory and the Cox modulus theory. The magnitude of this error is calculated for specific cases.     

Conceptual design of kenaf fiber polymer composite automotive parking brake lever using integrated TRIZ–Morphological Chart–Analytic Hierarchy Process method

This paper presents the conceptual design of kenaf fiber polymer composites automotive parking brake lever using the integration of Theory of Inventive Problem Solving (TRIZ), morphological chart and Analytic Hierarchy Process (AHP) methods. The aim is to generate and select the best concept design of the component based on the product design specifications with special attention to incorporate the use of natural fiber polymer composites into the component design. In this paper, the TRIZ contradiction matrix and 40 inventive principles solution tools were applied in the early solution generation stage. The principle solution parameters for the specific design characteristics were later refined in details using the aid of morphological chart to systematically develop conceptual designs for the component. Five (5) innovative design concepts of the component were produced and AHP method was finally utilized to perform the multi-criteria decision making process of selecting the best concept design for the polymer composite automotive parking brake lever component.     

Differences in the chemical structure of the lignins from sugarcane bagasse and straw

Two major residues are produced by the sugarcane industry, the fibrous fraction following juice extraction (bagasse), and the harvest residue (straw). The structures of the lignins from these residues were studied by pyrolysis coupled to gas chromatography-mass spectrometry (Py-GC/MS), nuclear magnetic resonance (NMR), and derivatization followed by reductive cleavage (DFRC). Whereas the lignin from bagasse has a syringyl-rich p-hydroxyphenyl:guaiacyl:syringyl (H:G:S) molar composition of 2:38:60, the lignin from straw is guaiacyl-rich (H:G:S of 4:68:28). The compositional differences were also reflected in the relative abundances of the different interunit linkages. Bagasse lignin was primarily β–O–4′ alkyl-aryl ether substructures (representing 83% of NMR-measurable linkages), followed by minor amounts of β–5′ (phenylcoumarans, 6%) and other condensed substructures. The lignin from straw has lower levels of β-ethers (75%) but higher relative levels of phenylcoumarans (β–5′, 15%) and dibenzodioxocins (5–5/4–O–β, 3%), consistent with a lignin enriched in G-units. Both lignins are extensively acylated at the γ-hydroxyl of the lignin side-chain (42% and 36% acylation in bagasse and straw), predominantly with p-coumarates (preferentially on S-units) but also with acetates (preferentially on G-units) to a minor extent. Tetrahydrofuran structures diagnostically arising from β–β-coupling (dehydrodimerization) of sinapyl p-coumarate or its cross-coupling with sinapyl alcohol were found in both lignins, indicating that sinapyl p-coumarate acts as a monomer participating in lignification. The flavone tricin was also found in the lignins from sugarcane, as also occurs in other grasses.     

Characteristics and Rheological Properties of Polysaccharide Nanoparticles from Edible Mushrooms (Flammulina velutipes)

Nanotechnology has become relevant in the food‐related industries, and edible mushrooms can be a potential raw material for providing satisfied edible nanomaterial. In this study, by following 3 different pretreatments (hot water or cold alkali or hot alkali) insoluble polysaccharide nanoparticles were prepared from Flammulina velutipes by wet milling and high pressure homogenization and their properties were investigated. The resultant nanoparticles were characterized by SEM, GC‐MS (for its main compositions), FTIR, XRD, and TG. The 1 wt% nanoparticle dispersions presented non‐Newtonian, shear‐thinning fluids with the viscosity in an increasing order for the hot water < cold alkali < hot alkali. Moreover, the dynamical rheological results showed differences of storage (G′) and loss (G″) moduli of these particle dispersions. It was concluded that the Flammulina velutipes‐derived polysaccharides nanoparticles have great potential applications in the food industry, for example, as emulsifiers, reinforcement agents, and bioactive carriers.     

A viewpoint on the gastrointestinal fate of cellulose nanocrystals

BackgroundCellulose nanocrystalline (CNC) particles possess unique functional properties such as vastly modifiable surface, considerable mechanical strength and acid resistance, as well as, high aspect ratio. CNCs have received great attention for application in diverse fields of technology including (composite) hydrogels fabrication for the gastric protection and enteral delivery of drugs and nutraceuticals.Scope and approachThe orogastrointestinal digestibility and absorbability of the orally administered CNCs is overviewed in the current article. At first, some surface charge-related characteristics of acid-isolated CNCs are communicated. Then, the biocompatibility and biodegradability of CNCs and CNC-reinforced hydrogels are reviewed, followed by presenting credible digestion and absorption scenarios. Finally, the post-absorption metabolism of CNCs is briefly debated.Key findings and conclusionsBacterial cellulose shows good biocompatibility and hemocompatibility. CNC oxidation provides biologically beneficial impacts; for instance, the TEMPO- and periodate-oxidized CNCs have been shown to regulate some blood metabolic variables and improve the degradability in simulated human blood plasma, respectively. Spherical and carboxyl-bearing cellulose nanoparticles can be isolated through ammonium persulfate digestion. The sphericity of particles results in faster cellular uptake. Negatively-charged CNCs are non-mucoadhesive and thus upon ingestion can penetrate into the buccal and intestinal mucosa. One may augment the absorption of CNCs by targeted receptor-mediated endocytosis. It was postulated that sodium bicarbonate secretion into the duodenum can alter CNCs surface chemistry and influence CNC interaction with gut microbiota.     

Intelligent release of cinnamon oil from engineered proteoliposome via stimulation of Bacillus cereus protease

Inspired by the hydrolysis of casein by protease, a new approach to deliver antimicrobials against bacterial infections was developed in this study. As a natural antibacterial agent, cinnamon oil was encapsulated into engineered liposomes inlaid with casein. The average particle size of proteoliposomes was 615.0 nm and their entrapment efficiency (EE) was 40.0%. In this work, Bacillus cereus (B. cereus) was chosen as model bacterium. The controlled release of liposome-encapsulated cinnamon oil was realized via bacterial protease secreted from B. cereus. As a result, 99.99% of the bacteria could be efficiently inhibited in rice and wheat flour.     

High speed microcompression of paper coatings

A novel high speed microcompression platen tester was developed in order to measure the out-of-plane compressive modulus of thin materials. The instrument is capable of subjecting a sample of thickness 20 μm or greater to a transverse compressive pulse over a time interval ranging from approximately 2 ms to several seconds, and can therefore be used to collect data under conditions representative of those in a high speed calender nip. In this study, free layers of coating formulations normally used to coat paper were prepared and tested using the microcompression platen tester described above. Tests were conducted at high speeds, with a pulse duration of 2 ms during the compressive stroke, and at 23 °C to simulate room temperature calendering conditions. The compressive modulus of the coating did not correlate strongly with the modulus of its constituent latex. Latex content, however, strongly affected coating compressive modulus. A sharp increase in the compressive modulus was observed at the coating critical pigment volume concentration (CPVC)—essentially the latex concentration at which the coating layer porosity is reduced to zero. Pigment size distribution and pigment morphology also affected the compressive modulus of coating in a manner consistent with packing theory.     

Determination of peroxygen species present in pulp fiber matrixes

A new chromatographic method for the determination of oxidants, such as peroxyborates and peroxides, present in a pulp matrix has been developed. The new method is characterized by its high reproducibility, its low limit of detection, and its high selectivity. Thioanisole (methylphenyl sulfide) is shown to selectively and quantitatively react with oxidants that are present within a pulp matrix. The experimental protocol proposed requires an HPLC system with a normal-phase column. The method allows for the quantitative monitoring of the thioanisole starting material, as well as the products of oxidation, methylphenyl sulfoxide and methylphenyl sulfone. After a 2-day reaction period, the analysis time for a sample is less than 20 min. The detection limit is 2.7 × 10(-6) M for the sulfoxide and sulfone and less than 5.0 × 10(-7) M for the thioanisole. This novel approach for monitoring oxidants present on solid lignocellulosic matrixes may provide pulp and paper manufacturers with a new tool for the study of the long-term bleaching effectiveness of peroxy-containing chemical additives.     

Fouling tendency of ash resulting from burning mixtures of biofuels. Part 1: Deposition rates

Specified mixtures of peat with bark and peat with straw were burned in a lab-scale entrained flow reactor that simulates conditions in the superheater region of a conventional biomass-fired boiler. The deposition rates were recorded on an air-cooled probe that was inserted into the reactor at the outlet. For both mixtures, the deposition behaviour followed a non-linear pattern, which suggests that physico-chemical interaction between the types of ash has taken place. Peat seems to act as a cleansing agent in all mixtures with straw, while it acts as a cleansing agent in mixtures with bark only up to a share of 50 wt% bark. Between 50 and 100 wt% bark, it seems that peat adds to the deposition. The results indicate that it is possible to burn up to 30 wt% bark (renewable biofuel and pulp mill waste) and up to 70 wt% straw (renewable biofuel and agricultural waste) in mixtures with peat (CO₂-neutral fossil fuel) without encountering increased deposition rates.