Control of Shear Thickening Onsets by Nanoparticles

With various applicability of shear thickening fluids (STFs), control of rheological properties of STFs has been a major interest to industry. While carbon nanotubues and graphene have often been employed as fillers of STFs, little has been examined for their individual and combined effects on shear thickening behavior. In this study, the onset of viscosity increase of STFs was examined for the addition of: 1D functionalized multi-walled carbon nanotubes (fMWCNTs); 2D reduced graphene oxides (rGO); 3D network of MWCNTs-rGO hybrids (H); and spherical iron oxides (Fe₃O₄). To overcome the poor dispersibility of carbon particles, carbon nanotubes were functionalized to attach carboxylic groups (fMWCNTs), and graphene oxides (GOs) were reduced using TiO₂ particles. Large hydrodynamic diameters of fMWCNT, rGO, and their hybrids of percolated network facilitated the interactions with silica particles in STF, decreasing the onset of shear thickening. Among the tested particles, STF with hybrids (H-STF) exhibited the lowest critical shear rate and the highest viscosity, due to the hybrid’s 3D network structure in which long and tortuous fMWCNTs bridged adjacent rGOs. The addition of Fe₃O₄ to HSTF shifted the shear thickening onset to a higher shear rate. The results demonstrate that the shear thickening onsets can be controlled by the selective additions of nanoparticles.     

Thermal Insulation Performance of Cotton and PET-based Hybrid Fabrics Impregnated with Silica Aerogel via a Facile Dip-dry Process

We report the morphological features and thermal insulation properties of a series of cotton- and PET-based hybrid fabrics impregnated with silica aerogel. For the purpose, commercially available cotton and PET knitted fabrics were dipped into aqueous dispersions including different silica aerogel contents, dried, and stacked to 1, 3, and 5 layers. The SEM images revealed that the silica aerogel particles were well incorporated into cotton or PET knitted fabrics. The thermal insulating performance of the hybrid fabrics as functions of the silica aerogel content and the number of layers of stacked fabrics were characterized by monitoring the surface temperatures of the fabrics on a plate with a wide temperature range of ~50-80 oC using an infrared camera. The higher thermal insulation performance was attained for both cotton- and PET-based hybrid fabrics with higher silica aerogel contents. In addition, 3-layered hybrid fabrics exhibited noticeably improved thermal insulation performance, compared to 1- or 5-layered fabrics. The thermal insulation property of the cotton-based hybrid fabrics was dominantly influenced by silica aerogel than that of PET-based hybrid fabrics. The overall results demonstrated that the cotton- and PET-based hybrid fabrics with silica aerogel manufactured by a facile dip-dry process could be utilized as protective garments, heat-sensitive devices, pipes, automotive, aircrafts, and buildings for thermal insulation applications.     

Antioxidant Properties of Scomber japonicus Hydrolysates Prepared by Enzymatic Hydrolysis

The antioxidant properties of the Pacific chub mackerel (Scomber japonicus) muscle protein hydrolysates prepared by enzymatic hydrolysis were investigated. After enzyme hydrolysis at 50°C for 60 min, more than 80% of the S. japonicus muscle protein was hydrolyzed. The highest 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity (71.69%) occurred in whole muscle protein hydrolysates treated at 50°C for 30 min with Protamex, and the highest 2,2?-azino-bis(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) radical-scavenging activity (95.39%) was observed in white muscle protein hydrolysates treated at 50°C for 30 min with Neutrase. The highest superoxide dismutase (SOD)-like activity (32.84%) was recorded in white muscle protein hydrolysates treated at 50°C for 120 min with Protamex. Changes in the molecular weight distribution of S. japonicus muscle proteins after enzymatic hydrolysis were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). A robust and a convenient enzyme hydrolysis technique for obtaining S. japonicus muscle protein hydrolysates with useful biological activities, within a short time (<2 h) is proposed.     

Comparisons of bearing properties for various oriented glulam using digital image correlation

The goal of this study was to analyze the bearing properties of the differently oriented glulam using digital image correlation (DIC). Six differently oriented specimens associated with three anatomical directions including longitudinal (L), radial (R), and tangential (T), and 12-mm drift pins were used to analyze the bearing properties, including yield load and bearing strength. The highest bearing strength of 22.57 MPa from RL was found, whereas the lowest bearing strength of 6.47 MPa from LR was found. Different strain distributions were observed from the differently oriented bearing specimens using DIC. Different failure ratios of the differently oriented specimens were highly related to the strain distributions. Although the bearing properties were found to be different between the differently oriented specimens, for the connection design aspect, the bearing properties of glulam could be grouped as RL and TL specimens, RT and TR specimens, and LR and LT specimens.     

Thermal effects on the development of <Emphasis Type="Italic">Bactrocera dorsalis</Emphasis> (Hendel) (Diptera: Tephritidae) and model validation in Taiwan

The oriental fruit fly, Bactrocera dorsalis (Hendel), is a major polyphagous insect pest with a worldwide distribution. The effects of temperature on stage-specific development in B. dorsalis were investigated at eight constant temperatures (13.0 °C, 14.4 °C, 16.2 °C, 19.5 °C, 23.8 °C, 27.7 °C, 31.8 °C and 34.8 °C). B. dorsalis developed successfully from the egg stage to the adult stage at all the tested temperatures, except at the lowest temperatures (13.0 °C and 14.4 °C). Stage-specific lower developmental thresholds and thermal constants were determined using linear regression. The lower and higher temperature threshold (TL and TH, respectively) were estimated using the Sharpe-Schoolfield-Ikemoto model. The lower developmental threshold and thermal constant from egg to adult emergence were 9.8 °C and 325.5 degree-days, respectively. The intrinsic optimum temperatures of the egg, larval, pupal and egg to pupal stage were 20.7 °C, 21.8 °C, 21.1 °C, and 22.4 °C, respectively. The temperature range of the B. dorsalis total immature stage from TL to TH was 20.4 °C (13.8 °C - 34.2 °C). The stage-specific developmental completion of B. dorsalis was determined using a two-parameter Weibull function. The daily adult emergence frequency of B. dorsalis was estimated in relation to adult age and temperature using non-linear developmental rate functions and the Weibull function. The date of cumulative 50% adult emergence estimated using non-linear functions was approximately one day earlier than the experimentally observed date. Thermal performance was compared among B. dorsalis populations from different locations.     

Laparoscopic colopexy for recurrent rectal prolapse in a Maltese dog

A 2.5-kg castrated male Maltese dog, suspected to be older than 10 y, was presented with a prolapsed mass at the anus. This had occurred on 2 previous occasions within the last 4 mo and had been managed with manual reduction and purse-string sutures. The rectal prolapse had viable tissue and was reducible but resulted in straining and fecal accumulation. Colopexy (with intracorporeal sutures) was performed laparoscopically using 3 ports; the distal colon was retracted cranially and attached to the abdominal wall with 3 simple interrupted sutures in a single row. The dog recovered uneventfully, had good appetite and normal activity, did not strain, and defecated without issues. There were no wound-healing complications and at 12-month post-operative examination, the patient was in good condition without clinical signs. Based on this case report, laparoscopic colopexy is clinically practical for management of rectal prolapse in small-breed dogs.     

Porphyra tenera Protects against PM2.5-Induced Cognitive Dysfunction with the Regulation of Gut Function

To evaluate the biological effects of Porphyra tenera (P. tenera), we tried to confirm the possibility that the intake of P. tenera could modulate cognitive and intestinal functions in PM_2.5-induced cognitive decline mice. P. tenera attenuated PM_2.5-induced learning and memory impairment through antioxidant and anti-inflammatory effects by regulating the mitochondrial function and TLR-initiated NF-κB signaling. In addition, P. tenera effectively alleviated Aβ production/tau phosphorylation by inhibiting the JNK phosphorylation. Also, the bioactive constituents of P. tenera determined the sulfated galactan, mycosporine-like amino acids (MAAs), and chlorophyll derivatives. Moreover, the bioactive compounds of P. tenera by gut fermentation protected against gut dysbiosis and intestinal tight junction damage with a decrease in inflammatory response and short-chain fatty acid production. Based on these results, our findings suggest that P. tenera with sulfated galactan and MAAs is a potential material for cognitive function improvement.