scholarly journals Cushion Mechanism of Goat Hoof Bulb Tissues

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Weijun Tian ◽  
Hai Liu ◽  
Qi Zhang ◽  
Bo Su ◽  
Wei Xu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Composite Structures ◽  
Epidermal Layer ◽  
Normal Model ◽  
The Finite Element Method ◽  
Dermal Layer ◽  
Subcutaneous Tissues ◽  
The Impact ◽  
Dermal Papillae ◽  
Scanning Electron

The hoof bulb sections of white goats were observed via scanning electron microscopy and stereomicroscopy in order to explore the cushion mechanism in the bulb tissue microstructures of hoofed animals. The hoof bulbs consisted of multilayer tissues, including an epidermal layer, a dermal layer, and subcutaneous tissues from outside to inside. A bionic model based on hoof bulb tissue composite structures was built with a normal model as the control. The microcosmic mechanics of the bulb tissues was analyzed via the finite element method. Simulations showed that when the bionic model was impacted by the top plates at the speed of 1-10 m/s, stress was concentrated in the epidermal layer and uniformly distributed in the dermal layer and dermal papillae, which effectively reduced the impact onto the ground. The cornified epidermal layer can resist the instant impact onto the ground, while the dermal papillae embedded in the dermal layer can store, release, and dissipate the impulsive energy, and the three parts synergically act in the cushion.

Effect of inorganic nanofillers on the impact behavior and fracture probability of industrial high-density polyethylene nanocomposite

2017 ◽  
Vol 52 (18) ◽  
pp. 2431-2442 ◽  
Author(s):  
Harun Sepet ◽  
Necmettin Tarakcioglu ◽  
RDK Misra
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Density Polyethylene ◽  
Fracture Probability ◽  
High Density ◽  
Impact Behavior ◽  
Inorganic Filler ◽  
Melt Mixing ◽  
The Impact ◽  
Scanning Electron

The main purpose of this work is to study how the morphology of nanofillers and dispersion and distribution level of inorganic nanofiller influence the impact behavior and fracture probability of inorganic filler filled industrial high-density polyethylene nanocomposites. For this study, nanoclay and nano-CaCO3 fillers–high-density polyethylene mixings (0, 1, 3, 5 wt.% high-density polyethylene) was prepared by melt-mixing method using a compounder system. The impact behavior was examined by charpy impact test, scanning electron microscopy, and probability theory and statistics. The level of the dispersion was characterized with scanning electron microscopy energy dispersive X-ray spectroscopy analysis. The results showed rather good dispersion of both of inorganic nanofiller, with a mixture of exfoliated and confined morphology. The results indicated that the impact strength of the industrial nanocomposite decreased with the increase of inorganic particulate content. The impact reliability of the industrial nanocomposites depends on the type of nanofillers and their dispersion and distribution in the matrix.

Aggregate Rays in New Zealand Nothofagus Blume (Fagaceae) Stem Wood and their Influence on Vessel Distribution

IAWA Journal ◽  
1987 ◽  
Vol 8 (1) ◽  
pp. 53-57 ◽  
Author(s):  
T. M. Middleton
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Zealand ◽  
Composite Structures ◽  
Growth Ring ◽  
Stem Wood ◽  
Scanning Electron

Aggregate rays occur in the stem wood of Nothofagus solandri var. cliffortioides (Hook. f.) Poole (mountain beech), N. solandri var. solandri (Hook. f.) Gerst. (black beech), N. truncata (Col.) Ckn. (hard beech), and N. fusca (Hook. f.) Gerst. (red beech), but not in N. menziesii (Hook. f.) Gerst. (silver beech). The composite structures visible in transversely sawn wood consist of groups of narrow xylem rays separated by fibres; vessels are frequently absent. The influence of aggregate rays on vessei distribution was studied using scanning electron microscopy and tested statistically. Indented growth ring boundaries are associated with the presence of aggregate rays. Aggregate rays occur in saplings. In larger trees aggregate rays taper out beyond 6 cm from the stem centre.

The Impact Properties of a Polyurethane Composite Filled with Clay

2011 ◽  
Vol 197-198 ◽  
pp. 1100-1103
Author(s):  
Jian Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Mechanical Analysis ◽  
Impact Testing ◽  
Impact Properties ◽  
Polyurethane Composite ◽  
The Matrix ◽  
The Impact ◽  
Scanning Electron

A polyurethane/clay (PU/clay) composite was synthesized. The microstructure of the composite was examined by scanning electron microscopy. The impact properties of the composite were characterized by impact testing. The study on the structure of the composite showed that clays could be dispersed in the polymer matrix well apart from a few of clusters. The results from mechanical analysis indicated that the impact properties of the composite were increased greatly in comparison with pure polyurethane. The investigation on the mechanical properties showed that the impact strength could be obviously increased by adding 20 wt% (by weight) clay to the matrix.

scholarly journals Hydroxypropylsulfonation/Caproylation of Cornstarch to Enhance Its Adhesion to PLA Fibers for PLA Sizing

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1197 ◽  
Author(s):  
Wei Li ◽  
Jie Wu ◽  
Xingui Cheng ◽  
Lanjuan Wu ◽  
Zhi Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Internal Stress ◽  
Mechanical Behaviors ◽  
Cohesive Failure ◽  
Adhesive Layers ◽  
Adhesion Measurement ◽  
Acid Sodium Salt ◽  
The Stability ◽  
The Impact ◽  
Scanning Electron

The impact of hydroxypropylsulfonation/caproylation on the adhesion of cornstarch to polylactic acid (PLA) fibers was investigated for ameliorating the applications such as PLA sizing. The hydroxypropylsulfonated and caproylated cornstarch (HCS) samples with different degrees of substitution (DS) were synthesized by a hydroxypropylsulfonation of acid-converted cornstarch (ACS) with 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt (CHPS-Na) and subsequently a caproylation with caproic anhydride (CA). The HCS granules were characterized by Fourier transform infrared spectroscopic and scanning electron microscopy. The adhesion was evaluated by measuring the bonding forces of the PLA roving impregnated. The mechanical behaviors of the adhesive layers were estimated by determining the properties of the films. The results of adhesion measurement were also analyzed especially through the wetting and spreading of the paste on the fiber surfaces, as well as the failure type, internal stress and mechanical behaviors of the adhesive layers among fibers. Additionally, apparent viscosity and its stability of the pastes were also determined. It was found that hydroxypropylsulfonation/caproylation was not only able to obviously improve the adhesion of ACS to PLA fibers, but also capable of further improving the adhesion of hydroxypropylsulfonated starch (HS) to the fibers. With the rise in the total DS, the adhesion gradually increased. The two substituents improved the wetting and spreading, reduced the internal stress, lowered the probabilities of interfacial failure and cohesive failure, decreased the film brittleness, and increased the van der Waals force at the interfaces. Moreover, the HCS samples with a stability of above 85% could meet the demand on the stability for sizing. Considering the experimental results of the adhesion and the analysis of the results, HCS showed potential in the application of PLA sizing.

scholarly journals Microstructure–Property Relationship of Polyurethane Foams Modified with Baltic Sea Biomass: Microcomputed Tomography vs. Scanning Electron Microscopy

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5734
Author(s):  
Paulina Kosmela ◽  
Jan Suchorzewski ◽  
Krzysztof Formela ◽  
Paweł Kazimierski ◽  
Józef Tadeusz Haponiuk ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Baltic Sea ◽  
Thermal Insulation ◽  
Reference Sample ◽  
Microcomputed Tomography ◽  
Polyurethane Foams ◽  
Relationship Of ◽  
The Impact ◽  
Scanning Electron

In this paper, novel rigid polyurethane foams modified with Baltic Sea biomass were compared with traditional petro-based polyurethane foam as reference sample. A special attention was focused on complex studies of microstructure, which was visualized and measured in 3D with high-resolution microcomputed tomography (microCT) and, as commonly applied for this purpose, scanning electron microscopy (SEM). The impact of pore volume, area, shape and orientation on appearance density and thermal insulation properties of polyurethane foams was determined. The results presented in the paper confirm that microcomputed tomography is a useful tool for relatively quick estimation of polyurethane foams’ microstructure, what is crucial especially in the case of thermal insulation materials.

scholarly journals Effects of Droplet-Vitrification Cryopreservation Based on Physiological and Antioxidant Enzyme Activities ofBrassidiumShooting Star Orchid

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Safrina Rahmah ◽  
Safiah Ahmad Mubbarakh ◽  
Khor Soo Ping ◽  
Sreeramanan Subramaniam
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Liquid Nitrogen ◽  
Enzyme Activities ◽  
Structural Changes ◽  
Total Soluble Protein ◽  
Antioxidant Enzyme Activities ◽  
Droplet Vitrification ◽  
The Impact ◽  
Scanning Electron

Protocorm-like bodies (PLBs) ofBrassidiumShooting Star orchid were successfully cryopreserved using droplet-vitrification method. Vitrification based cryopreservation protocol is comprised of preculture, osmoprotection, cryoprotection, cooling, rewarming, and growth recovery and each and every step contributes to the achievement of successful cryopreservation. In order to reveal the lethal and nonlethal damage produced by cryopreservation, histological observation, scanning electron microscopy (SEM), and biochemical analysis were carried out in both cryopreserved and noncryopreserved PLBs ofBrassidiumShooting Star orchid comparing with the control PLBs stock culture. Histological and scanning electron microscopy analyses displayed structural changes in cryopreserved PLBs due to the impact of cryoinjury during exposure to liquid nitrogen. Total soluble protein significantly increased throughout the dehydration process and the highest value was achieved when PLBs were stored in liquid nitrogen. Ascorbate peroxidase (APX) and catalase (CAT) showed the highest enzyme activities in both dehydration and cryostorage treatments indicating that stress level of PLBs was high during these stages.

Revised taxonomy and redescription of two species of the Peripatidae (Onychophora) from Brazil: a step towards consistent terminology of morphological characters

Zootaxa ◽  
2010 ◽  
Vol 2493 (1) ◽  
pp. 16 ◽  
Author(s):  
IVO DE SENA OLIVEIRA ◽  
ALFREDO HANNEMANN WIELOCH ◽  
GEORG MAYER
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Type Species ◽  
Morphological Characters ◽  
Type Material ◽  
Taxon Sampling ◽  
The Caribbean ◽  
Dermal Papillae ◽  
Scanning Electron

Based on the supposed quadrangular shape of the basal pieces of dorsal primary papillae, several species of the “Caribbean group” of the neotropical Peripatidae, including Macroperipatus acacioi and M. machadoi, were assigned to Macroperipatus. So far, the quadrangular shape of dermal papillae was confirmed only for M. torquatus, the type species of the genus. Previous observations revealed that the putatively quadrangular shape reported from other species of the “Caribbean group” might be a fixation artefact. Hence, detailed reinvestigations of all putative Macroperipatus species are required to clarify their taxonomy. In the present study, two species of the “Caribbean group”, M. acacioi and M. machadoi, are analyzed and redescribed, based on type material and topotype specimens collected at the corresponding type localities. The original descriptions of both species are complemented with data obtained from scanning electron microscopy, in addition to conventional morphological methods. The quadrangular bases of primary papillae are shown to be absent from M. acacioi and M. machadoi, thus suggesting that these two species are not closely related to M. torquatus. The new data instead suggest that these two species are representatives of Epiperipatus: E. acacioi comb. nov. and E. machadoi comb. nov.. The present study highlights the use of scanning electron microscopy for clarifying the taxonomy and phylogeny of the neotropical Peripatidae. It also reveals gaps in taxon sampling and problems regarding the ambiguous terminology of morphological characters used for describing the anatomy of peripatids. An attempt is made towards a consistent terminology for species (re)descriptions and studies of onychophoran anatomy and phylogeny.

Influence of Injection Conditions on the Mechanical Property of MWCNTs/ PC Nanocomposites

2014 ◽  
Vol 983 ◽  
pp. 94-98 ◽  
Author(s):  
Li Jun Wang ◽  
Jian Hui Qiu ◽  
Eiichi Sakai
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Bending Strength ◽  
Surface Hardness ◽  
Interfacial Interaction ◽  
Multiwalled Carbon ◽  
The Matrix ◽  
The Impact ◽  
Scanning Electron

The melting mixing was applied in the preparation of Multiwalled carbon nanotubes/Polycarbonate (MWCNTs/PC) nanocomposites. MWCNTs/PC nanocomposites with different MWCNTs contents were prepared under different injection conditions. The mechanical property of nanocomposites was comparatively investigated. The results demonstrated that: the tensile property of the nanocomposites was slightly improved by MWCNTs content increasing; but as the MWCNTs contents went on to increase to 10wt%, the tensile strength and bending strength were obviously decreased about 35% and 47%, respectively, but the impact strength and hardness were increased. The center hardness of MWCNTs/PC nanocomposites was greater than the surface hardness. Besides, the changes on the mechanical properties of the nanocomposites were studies by changing the injection conditions. By Scanning Electron Microscopy (SEM) observation, the microstructure and morphology of nanocomposites were analyzed, revealing that the center of the nanocomposite distributed more MWNTs, and the injection conditions would affect the MWNTs’ dispersion in the matrix and the interfacial interaction between MWCNTs and PC.

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