Design and research of cutting load measuring device for coal and rock

Based on the analysis of the present situation of the research on the cutting process of the drum, the research method of the equipment capable of obtaining the cutting force in the drum cutting process is proposed by combining the finite element explicit dynamic analysis. Aiming at the complicated force of the shearer’s pick cutter in cutting the coal rock. In this paper, the finite element software is used to explicit dynamics simulate the picking of coal mining in the cutting process, and the strain distribution on the cutting is determined. Based on this, the use of strain gauge bridge design ideas to indirectly obtain the force on the cutter, and finally get the relevant experimental data. Compared with the finite element simulation analysis, the feasibility of the two schemes is explained, and the foundation of the follow-up experiment is laid

Preparation and characterization of whey protein isolate films reinforced with porous silica coated titania nanoparticles

Whey protein isolate (WPI) films embedded with TiO2@@SiO2 (porous silica (SiO2) coated titania (TiO2)) nanoparticles for improved mechanical properties were prepared by solution casting. A WPI solution of 1.5 wt% TiO2@@SiO2 nanoparticles was subjected to sonication at amplitudes of 0, 16, 80 and 160 μm prior to casting in order to improve the film forming properties of protein and to obtain a uniform distribution of nanoparticles in the WPI films. The physical and mechanical properties of the films were determined by dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and tensile testing. Water vapor permeability (WVP) measurements revealed that the water vapor transmission rates are slightly influenced by sonication conditions and nanoparticle loading. The DMA results showed that, at high sonication levels, addition of nanoparticles prevented protein agglomeration. The thermal stability of the materials revealed the presence of 3–4 degradation stages in oxidizing the protein films. The addition of nanoparticles strengthens the WPI film, as evidenced by tensile stress analysis. Sonication improved nanoparticle distribution in film matrix; such films can potentially become effective packaging materials to enhance food quality and safety

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Microstructure and Antimicrobial Functionality of Nano-Enhanced Protein-Based Biopolymers

Whey protein isolates (WPI) and corn zein protein (CZP) films, embedded with porous silica-coated titanium nano-enhancers (TiO2@@SiO2), were prepared and exhibited enhanced antimicrobial functionality. Protein solutions at 5% WPI and 13.5% CZP were amended with 1.5% w/w of TiO2@@SiO2 nano-enhancers and subjected to sonication at 0, 16, 80, and 160 µm amplitude prior to casting into films. The effects of sonication on nano-enhancer distribution and the structure and morphology of the resulting films were elucidated by transmission electron microscope (TEM). The surface structure of the films was altered by the presence of nano-enhancers. The nano-enhanced biopolymer films exhibited antimicrobial functionality under sunlight by effectively inhibiting bacterial growth. The nano-enhanced biopolymers can potentially be used to make active antimicrobial surface coatings or packaging films to inhibit or slow down microbial growth during storage.The following article is from Transactions of the ASABE 57 (2014): 1141–1150, doi:10.13031/trans.57.10379. Posted with permission.</p

Preliminary safety assessment of oridonin in zebrafish

Context: Oridonin, isolated from the leaves of Isodon rubescens (Hemsl.) H.Hara (Lamiaceae), has good antitumor activity. However, its safety in vivo is still unclear. Objective: To investigate the preliminary safety of oridonin in zebrafish. Materials and methods: Embryo, larvae and adult zebrafish (n = 40) were used. Low, medium and high oridonin concentrations (100, 200 and 400 mg/L for embryo; 150, 300 and 600 mg/L for larvae; 200, 400 and 800 mg/L for adult zebrafish) and blank samples were administered. At specific stages of zebrafish development, spontaneous movement, heartbeat, hatching rate, etc., were recorded to assess the developmental effects of oridonin. VEGFA, VEGFR2 and VEGFR3 gene expression were also examined. Results: Low-dose oridonin increased spontaneous movement and hatching rate with median effective doses (ED50) of 115.17 mg/L at 24 h post-fertilization (hpf) and 188.59 mg/L at 54 hpf, but these values decreased at high doses with half maximal inhibitory concentrations (IC50) of 209.11 and 607.84 mg/L. Oridonin decreased heartbeat with IC50 of 285.76 mg/L at 48 hpf, and induced malformation at 120 hpf with half maximal effective concentration (EC50) of 411.94 mg/L. Oridonin also decreased body length with IC50 of 324.78 mg/L at 144 hpf, and increased swimming speed with ED50 of 190.98 mg/L at 120 hpf. The effects of oridonin on zebrafish embryo development may be attributed to the downregulation of VEGFR3 gene expression. Discussions and conclusions: Oridonin showed adverse effects at early stages of zebrafish development. We will perform additional studies on mechanism of oridonin based on VEGFR3