Evaluation and comparison the properties of acoustic boards made of date palm fiber

Applying acoustic panels made of natural fibers, due to their high biodegradable characteristics, light weight, low density, cheap price and non-toxicity, are proper alternatives to acoustic absorbers made of synthetic fibers. Considering their stance and vast applicability in industry, the possibility of producing them of natural palm fibers with sodium silicate adhesive of 10 and 20% in two 16 and 32 mm thicknesses, 350 and 450 kg/m3 densities, 50 and 100 mm particles length (strands), as variable factors in 16 types of matched panels with 3 repetitions is proposed in this article. The palm-trunk discs constituted the control sample. The effect of variables on sound absorption coefficient was assessed. The effect of variable thickness and adhesive percentage on all frequencies was significant and the effect of density variable on all frequencies except 250 and 2000 Hz was also significant. The effect of particle length was significant except at the 500 Hz frequency. The effects of all variables on porosity were significant. The results of this study suggest that by applying date palm-trunk (an agricultural waste) combined with sodium silicate adhesive, industrial environment-friendly panels can be produced with proper sound absorption coefficient in the field of acoustics. This 32-mm-thick panel was composed of 80% date palm-trunk particles of 50 mm length, 450 kg/m3 density, and 20% sodium silicate adhesive.

Role of Adsorbed Polymers on Nanoparticle Dispersion in Drying Polymer Nanocomposite Films

Polymers adsorbed on nanoparticles (NPs) are important elements that determine the dispersion of NPs in polymer nanocomposite (PNC) films. While previous studies have shown that increasing the number of adsorbed polymers on NPs can improve their dispersion during the drying process, the exact mechanism remained unclear. In this study, we investigated the role of adsorbed polymers in determining the microstructure and dispersion of NPs during the drying process. Investigation of the structural development of NPs using the synchrotron vertical-small-angle X-ray scattering technique revealed that increasing polymer adsorption suppresses bonding between the NPs at later stages of drying, when they approach each other and come in contact. On the particle length scale, NPs with large amounts of adsorbed polymers form loose clusters, whereas those with smaller amounts of adsorbed polymers form dense clusters. On the cluster length scale, loose clusters of NPs with large amounts of adsorbed polymers build densely packed aggregates, while dense clusters of NPs with small amounts of adsorbed polymers become organized into loose aggregates. The potential for the quantitative control of NP dispersion in PNC films via modification of polymer adsorption was established in this study.

Exploring the gelation of aqueous cellulose nanocrystals (CNCs)-hydroxyethyl cellulose (HEC) mixtures

We investigated the gelation and microstructure of cellulose nanocrystals (CNCs) in nonionic hydroxyethyl cellulose (HEC) solutions. Cellulose nanocrystals (CNCs) with a particle length of 90 nm and width of 8 nm currently produced by acid hydrolysis of wood pulp were used in this study. The microstructures of CNCs/polymer suspensions were investigated by performing linear small amplitude oscillatory shear (SAOS) and nonlinear large amplitude oscillatory shear (LAOS), in addition to constructing CNCs phase diagrams and measuring steady-state shear viscosities. Significant viscosity increases at low shear rates coupled with high shear thinning behaviors were observed in CNCs in HEC solutions above the overlapping concentration of HEC. The physical strength of CNCs/HEC solution gels increased with the increase in CNCs concentration and resembled the weakly crosslinked gels according to the scaling of linear dynamic mechanical experiments. According to LAOS analysis, CNCs/HEC mixtures showed type III behavior with intercycle stress softening, while the samples showed stress stiffening in single cycles. Graphical abstract

Cattle Feeding Experiment and Chopping Device Parameter Determination for Mechanized Harvesting of Forage Rape Crop

HighlightsForage rape crop could effectively alleviate the lack of green forage for livestock in winter.With the growth of forage rape crop, stem lignification was exacerbated and its palatability degenerated.The relationship between particle length and palatability was explored in a cattle feeding experiment.Optimal working parameters of the chopping device were obtained for harvesting the crop in different stages.Abstract. Forage rape crop, which uses the immature plant leaf and stem of a hybrid rape crop (Brassica napus L.) with low erucic acid and glucosinolate to feed livestock, is an innovative fresh-fed feed material with the advantages of high yield, low cost, rich nutrients, and vigorous growth in winter. In this work, a systematic study was carried out on the relationships among the characteristics of forage rape crop stems, chopping device parameters of the harvester, feeding performance, and chopped particle length (PL) in different growth stages. The results of the stem characteristics tests indicated that stem lignification occurred and increased with growth of the crop from the bolting stage to the silique stage, leading to degeneration of its palatability. The cattle feeding experiment showed that when the bolting rape crop was used, the average feed intake of the cattle fed the chopped rape crop increased by 33.35%, compared to feeding the whole crop without chopping, while the average feeding time decreased by 35.44%. Further experiments on the effects of PL after chopping on feeding performance in different growth stages showed that the optimal PL values in the bolting, flowering, and silique stages were 80, 60, and 30 mm, respectively. Finally, the corresponding cutterhead rotational speeds of the chopping device were calculated as 450, 510, and 1200 r min-1, respectively. This study provides a reference for the development and application of harvesting equipment for forage rape crop. Keywords: Agricultural mechanization, Cattle feeding, Forage palatability, Harvester, Parameter matching.

Epitheliotropic T-cell lymphoma in 2 half-sibling bontebok

We diagnosed epitheliotropic T-cell lymphoma of the forestomachs in 2 aged, half-sibling, zoo-managed bontebok ( Damaliscus pygargus pygargus). One bontebok also had mesenteric lymph node and cutaneous involvement. Both animals had a history of chronic abdominal distension and diminished body condition that resulted in euthanasia. At autopsy, both animals had marked ruminal distension with diffusely blunted ruminal papillae and reticular crests. In case 1, there was an increased amount and particle length of the ruminoreticular fibrous material with scant fluid, and a 2-cm diameter focus of cutaneous crusting adjacent to a mammary teat. In case 2, the rumen and reticulum were fluid-distended with decreased fibrous material. Histologically in case 1, the rumen, reticulum, omasum, and skin had intraepithelial nests and sheets of neoplastic small lymphocytes; in case 2, the rumen and reticulum had a similar neoplastic cell population. Immunohistochemically, neoplastic lymphocytes were immunoreactive for CD3 and negative for CD20, confirming the diagnosis of epitheliotropic T-cell lymphoma.

Utilization of Nanocrystalline Cellulose for Adsorption of Divalent Cobalt Ions in the Aqueous Phase

Nanocrystalline cellulose (NC) is a cellulose derivative product that has attracted a lot of attention because of its versatile applications, one of which is in adsorption. In this study, NC was prepared through H2SO4-hydrolysis of filter paper. Several physical characterizations were employed to confirm the formation of the NC nanoparticles, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis, and Fourier transform infrared spectroscopy (FTIR). The nano-rod-shaped NC particles, with an average particle length of 255 nm, were observed from the electron micrographs. The resemblance characteristic of NC with cellulose was demonstrated from the occurrence of XRD peaks at (110) and (200) lattice plane. The FTIR bands’ spectra of the NC are similar to that of the reported literature. The NC was utilized as the adsorbent for the removal of cobalt ions in the synthetic solution. The effect of pH on the removal of cobalt ions by NC was evaluated by employing potentiometric titration. It was revealed that the complexation between the two compounds occurs greater at a pH of 6.6. The adsorption isotherm of cobalt ions was investigated at three different temperatures of 30, 45, and 60°C. The adsorption isotherm was found to be well fitted with the Langmuir model, with the maximum adsorption capacity of 47.53 mg g-1 at 30°C. The adsorption capacity was found to decline as the temperature increased, where the maximum adsorption capacity was 44.62 ± 2.32 and 40.56 ± 2.03 mg g-1 at 45 and 60°C, respectively. The adsorption of cobalt ions on NC shows the exothermic adsorption behavior.

Investigation of the Effect of the Length and Content of Carbon Fibers on the Properties of Polyphenylene Sulfide

The article presents the results of a study of the effect of milled and chopped carbon fibers, with an average particle length of 0.2 and , respectively, on the mechanical properties of polyphenylene sulfide and its heat resistance. It was found that the introduction of carbon fibers leads to a significant decrease in the melt flow rate. It was shown that after a sharp decrease in impact strength at 10 % content of carbon fibers, its inverse improvement occurs with an increase in the filler content. Composites containing carbon fibers with length demonstrate higher impact strength. The introduction of a filler leads to a significant increase in the elastic modulus and strength of polyphenylene sulfide and its heat resistance.

The Influence of Electric Field Intensity and Particle Length on the Electrokinetic Transport of Cylindrical Particles Passing through Nanopore

The electric transport of nanoparticles passing through nanopores leads to a change in the ion current, which is essential for the detection technology of DNA sequencing and protein determination. In order to further illustrate the electrokinetic transport mechanism of particles passing through nanopores, a fully coupled continuum model is constructed by using the arbitrary Lagrangian–Eulerian (ALE) method. The model consists of the electric field described by the Poisson equation, the concentration field described by Nernst–Planck equation, and the flow field described by the Navier–Stokes equation. Based on this model, the influence of imposed electric field and particle length on the electrokinetic transport of cylindrical particles is investigated. It is found firstly the translation velocities for the longer particles remain constant when they locate inside the nanopore. Both the ion current blockade effect and the ion current enhancement effect occur when cylindrical particles enter and exit the nanopore, respectively, for the experimental parameters employed in this research. Moreover, the particle translation velocity and current fluctuation amplitude are dominated by the electric field intensity, which can be used to adjust the particle transmission efficiency and the ion current detectability. In addition, the increase in particle length changes the particle position corresponding to the peak value of the ion current, which contributes to distinguishing particles with different lengths as well.