Effect of Coupling Agent on Softwood Kraft Nanocellulose Fibril-Reinforced Polylactic Acid Biocomposite

The nanocellulose fibril produced by using natural sources can be used in developing sustainable and green products. The useful features of nanocellulose fibril can include valuable physical properties, appropriate surface chemistry, low toxicity, and biocompatibility. The study presented shows the use of polylactic acid with five different percentages of nanocellulose fibril and the use of 3% maleic anhydride as a coupling agent. The maleic anhydride acts as coupling agent which improves the thermochemical and thermomechanical characteristics of the end product. The addition of 3% maleic anhydride as coupling agent with 10% nanocellulose fibril improved the impact strength up to 14.3%, elastic modulus up to 40.6%, and tensile strength up to 30.1%. Furthermore, the dynamic mechanical analysis result indicates that the inclusion of maleic anhydride improved the toughness by reducing the tan δ peak and increases the storage modulus. Finally, the scanning electron micrograph shows that the interfacial compatibility between nanocellulose fibril and polylactic acid matrix is improved with the addition of maleic anhydride.

Effect of Chemically Treated Kenaf Fibre on Mechanical and Thermal Properties of PLA Composites Prepared through Fused Deposition Modeling (FDM)

Natural fibre as a reinforcing agent has been widely used in many industries in this era. However, the reinforcing agent devotes a better strength when embedded with a polymer matrix. Nevertheless, the characteristic of natural fibre and polymer matrix are in contrast, as natural fibre is hydrophilic, while polymer is hydrophobic in nature. Natural fibre is highly hydrophilic due to the presence of a hydroxyl group (-OH), while polymer matrix has an inherent hydrophobic characteristic which repels water. This issue has been fixed by modifying the natural fibre’s surface using a chemical treatment combining an alkaline treatment and a silane coupling agent. This modifying process of natural fibre might reduce the attraction of water and moisture content and increase natural fibre surface roughness, which improves the interfacial bonding between these two phases. In this paper, the effect of alkaline and silane treatment has been proven by performing the mechanical test, Scanning Electron Micrograph (SEM), and Fourier Transform Infrared spectrometry (FTIR) to observe the surface structure. The chemical compositions and thermal properties of the composites have been obtained by performing Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) tests. 1.0% silane treatment displayed better strength performance as compared to other composites, which was proven by performing Scanning Electron Micrograph (SEM). The assumption is that by enduring chemical treatment, kenaf fibre composites could develop high performance in industry applications.

Physicochemical, Functional, Fatty Acids Profile, Health Lipid Indices, Microstructure and Sensory Characteristics of Walnut-Processed Cheeses

In the present study, processed cheeses fortified with walnut paste (a high source of omega-3 fatty acids) were developed and characterized. In order to identify the best cheese formulation, the effects of different proportions of walnut paste (0, 5, 10, and 15%) on cheese physicochemical, functional, fatty acids profile, health lipid indices (atherogenic and thrombogenic), microstructure, and sensorial characteristics were studied. Results showed that walnut-added samples had significantly (p ≤ 0.05) higher levels of acidity, protein, fat, and ash contents with lower meltability and oil separation index compared to the control. Processed cheeses with walnuts contained significantly (p ≤ 0.05) higher percentages of MUFAs, and ω-3 PUFAs (mainly α-linolenic acid) and significantly (p ≤ 0.05) lower amounts of SFAs (mainly myristic, palmitic and stearic acids) and ω6/ω3 ratio. Scanning Electron Micrograph of processed cheese containing walnut paste showed uniform distribution of walnut in the protein matrix. Processed cheeses made with 5 or 10% walnut paste presented the most acceptable sensory properties. These results indicated that walnut paste supplementation can be used as a nutritional strategy to increase concentrations of human health-promoting fatty acids in processed cheeses while maintaining good sensory and technological properties.

First record of gregarine protists (Apicomplexa: Sporozoa) in Asian fungus-growing termite Macrotermes barneyi (Blattaria: Termitidae)

Macrotermes barneyi, widely distributed in southern China, is the major fungus-growing termite in the subfamily Macrotermitinae. It has no flagellated protists in the guts. Here, we report occurrence of gregarine, a protozoan parasite in the digestive tract of M. barneyi. The general morphology and ultrastructure of the gregarine gamonts and syzygies by light micrograph and scanning electron micrograph are presented. SSU rDNA sequence analysis showed that the termite gregarine has the highest identity (90.10%) to that of Gregarina blattarum from cockroaches. Phylogenetic analysis based on the SSU rDNA sequences from diverse insect eugregarines indicated that the gregarine from M. barneyi is phylogenetically close to G. blattarus, L. erratica and G. tropica from Gregarinidae and Leidyanidae families, and may represent a novel species. This study expands our knowledge about the diversity of terrestrial eugregarines parasitizing in termites.

The first record of the subfamily Dasycerinae in Taiwan, with description of a new species (Coleoptera: Staphylinidae)

Dasycerus poseidon Hu & Liang, sp. nov. is described and illustrated based on fresh specimens from central and southern Taiwan, which filled in the disjunct distribution between the Japanese archipelago and south-eastern Asia. The new species represents the first record of the subfamily Dasycerinae in Taiwan. The barcoding sequence of the holotype of D. poseidon Hu & Liang, sp. nov.is provided, and revealed a surprisingly large genetic distance within the genus. Detailed illustrations of D. poseidon Hu & Liang, sp. nov. by scanning electron micrograph and micro-computed tomography are also provided. Living individuals of D. poseidon Hu & Liang, sp. nov. were observed eating the mycelium of Pleurotus ostreatus in lab conditions, which represents the first direct evidence of mycophagous habits of Dasycerinae.

Hierarchical aligned ZnO nanorods on surface of PVDF/Fe2O3 nanofibers by electrospinning in a magnetic field

The electrospinning was applied to fabricate aligned nanofibers in a magnetic field. Fe2O3 nanoparticles were added to PVDF/Zn(CHCOOH)2solution, and heat treatment of the nanofiber mats was made to produce PVDF/Fe2O3nanofibers containing ZnO nanoparticles. Hierarchical composites were obtained via a facile hydrothermal growth process, where radially oriented ZnO nanorods were found. The morphology of the as-synthesized samples were investigated by using the scanning electron micrograph (SEM).

PHYTOCHEMICAL CONTENT, PHYSICOCHEMICAL AND MICROSTRUCTURAL PROPERTIES OF APPLE POWDER AS AFFECTED BY DRYING METHOD

Apple in forms of slice and juice dried through methods of freeze drying (FZD), microwave drying (MWD), oven drying (OVN), spray drying (SPD) and foam mat drying (FMD) and the resulted powders were characterized in terms of water activity, vitamin C (Vc), phenolic compounds (TP), anthocyanin (TA), density, porosity, color, glass transition temperature and microstructure. The nutritional quality of apple powders expressed by the amount of Vc, TP and TA was found to be in the highest level in samples obtained after FZD followed by SPD. The minimum shift of color indexes from fresh apple observed for FZD followed by MWD. The highest and lowest bulk and true density were noted after OVD and FMD, and FZD and SPD, respectively. DSC analysis showed the powders obtained from apple slice through FZD, MWD and OVD have significantly lower Tg than those of produced from apple juice, by SPD and FMD. Scanning electron micrograph confirmed the porous structure of FMD and FZD and the dense structure of OVD.

Rediscovery of the horseshoe shrimp Lightiella serendipita Jones, 1961 (Cephalocarida: Hutchinsoniellidae) in San Francisco Bay, California, USA, with a key to the worldwide species of Cephalocarida

Lightiella serendipita Jones, 1961 was first discovered in San Francisco Bay, California in 1953, but it had not been observed since 1988. In 2017, a total of 13 adult L. serendipita specimens were found as part of a study in central San Francisco Bay, nearly doubling the total number of specimens ever collected. We measured vertical distribution of macroinvertebrates and environmental variables, including grain size and chemical composition of sediment samples, to evaluate potential features associated with the habitat of the species. Specimens were generally found in sediments with low organic matter (1.7–3%), high sulfate concentrations (594.6–647 ppm SO4), fine grain size (12.8–36.2% sand, 35.6–58% silt, 22.8–37.6% clay) and were mostly found in deep core sections (4–10 cm). Specimens were also consistently observed in cores containing tube-forming Polychaeta (i.e., Sabaco elongatus (Verrill, 1873) and Capitellidae), suggesting L. serendipita may have a commensal relationship with sedentary polychaetes, as do other cephalocaridans such as Lightiella incisaGooding, 1963. We provide a scanning electron micrograph of L. serendipita and the first complete key to the species in class Cephalocarida to help elucidate the taxonomy of this rare crustacean taxon. The perceived absence of L. serendipita in previous surveys of the Bay may be attributable to its rarity; however, additional research is needed to fully understand habitat requirements and population size of this unique endemic species.

Research on Preparation and Properties of Nylon 66/MMT/MWCNT Nanocomposites by In Situ Polymerization

The MWCNT-COOH and CTAB modified MMT were hybridized by the ultrasonic method, and the nylon 66/MMT/WMCNT composite was prepared by in-situ polymerization to study the effect of the introduction of MMT and MWCNT on the properties of nylon 66. A scanning electron micrograph of the composite cross-section shows that the CNTs were uniformly dispersed in the nylon 66 matrix. The XRD patterns show that the introduction of MMT and MWCNT-COOH caused the ratio of α1 and α2 of nanocomposites. The TGA results show that the heat resistance and residual carbon content of the composite material are improved. The mechanical properties of nanocomposites show that the mechanical properties of the material are improved relative to pure PA66.