Addressing Unfavorable Influence of Particle Cracking with a Strengthened Shell Layer in Ni-Rich Cathodes

2021 ◽  
Author(s):  
Meng Liu ◽  
Zhongming Ren ◽  
Deyu Wang ◽  
Haitao Zhang ◽  
Yujing Bi ◽  
...  
Keyword(s):  
Shell Layer ◽  
Particle Cracking

Taxonomy and phylogeny of the Triassic bivalve families Mysidiellidae Cox, 1964 and Healeyidae new family

2008 ◽  
Vol 82 (3) ◽  
pp. 555-564 ◽  
Author(s):  
M. Hautmann
Keyword(s):  
Outer Shell ◽  
Junior Synonym ◽  
Late Triassic ◽  
Late Paleozoic ◽  
Great Similarity ◽  
Shell Layer ◽  
Shell Microstructure ◽  
General Shape ◽  
New Family

The Mysidiellidae are morphologically isolated among Triassic bivalves but share important characters with Late Paleozoic Ambonychioidea. Apart from a great similarity in the general shape of the shell, the most primitive mysidiellid genus Promysidiella resembles ambonychioids in the presence of a duplivincular-opisthodetic ligament system. Within the Mysidiellidae, this ligament type evolved into the transitional ligament system that characterizes Late Triassic Mysidiella. The phyletic polarity indicates that this evolution probably took place by paedomorphosis. New examinations of the shell microstructure of Mysidiella demonstrate the presence of simple prismatic and possibly foliated structures in the calcitic outer shell layer, which further supports an ambonychioid affinity. Therefore, the Mysidiellidae are removed from the Mytiloidea and assigned to the Ambonychioidea. The poorly known genus Protopis, which was originally included in the Mysidiellidae, probably had a parivincular ligament system and was hence a member of the Heteroconchia. Joannina, which was previously considered a junior synonym of Protopis, is re-established. The hinge margin of Joannina carries a well developed nymph but lacks teeth. These characters as well as its modioliform shape, anterior shell lobe, and pronounced diagonal carina link Joannina with the Late Triassic genus Healeya (Modiomorphoidea). Both taxa are herein placed in the new family Healeyidae, which differs from the morphologically similar Kalenteridae in the absence of elaborated hinge teeth. Protopis, as well as the recently described genera Leidapoconcha, Waijiaoella, and Qingyaniola, are tentatively assigned to the Healeyidae.

An Egg-Waxing Organ in Ticks

1948 ◽  
Vol s3-89 (7) ◽  
pp. 291-332
Author(s):  
A. D. LESS ◽  
J.W. L. BEAMENT
Keyword(s):  
Inorganic Ions ◽  
Follicle Cells ◽  
Shell Layer ◽  
Critical Temperatures ◽  
Inner Membrane ◽  
Humid Atmosphere ◽  
Yellow Grease ◽  
Accessory Glands ◽  
Pore Canals ◽  
Natural Wax

1. During the oviposition of ticks a glandular organ--the organ of Géné is everted and touches the egg. If it is prevented from everting most of the eggs shrivel rapidly; few hatch even in a humid atmosphere. 2. The waterproofing properties of the normal egg are conferred by a superficial coating of wax, 0.5-2.0 µ. in thickness. In Ornithodorus moubata the wax is secreted and applied solely by Géné's organ. In Ixodes ricinus waterproofing takes place in two stages: an incomplete covering of wax, probably secreted by the lobed accessory glands, is first smeared over the egg during its passage down the vagina; waterproofing is then completed by a further application of wax from Géné's organ after the egg has been laid. Owing to its superficial position on the egg the wax layer is readily attacked by solvents and emulsifiers. 3. The morphology of Géné's organ in O. moubata is described. The gland is a proliferation of the epidermis which lies detached from the cuticle. Its secretion, a watery refractile liquid containing the wax precursor, accumulates between the gland and the cuticle in two horn-like extensions. The wax is probably secreted through pore canals distributed over a narrow zone of cuticle below the horns; the cement covering-layer of the epicuticle does not extend to this zone. 4. The transparent, heat-stable material isolated from the horns of Géné's organ is regarded as the wax precursor. Solubility in water is probably con ferred by chemical linkage with protein. The precursor is taken up from the horns, where it is stored, and is presumably broken down within the gland cells. The wax is then secreted through the pore canals while the protein moiety is retained by the cell. 5. The critical temperatures of the eggs of Ixodidae range from 35° C. in I. ricinus to 44° C. in Hyalomma savignyi; only slightly higher critical temperatures were recorded for Argasidae (45° C. in O. moubata). Eggs with lower critical temperatures are more susceptible to desiccation. The susceptibility of the eggs of a given species is of the same order as that of the parent species; but whereas in Ixodidae the critical temperatures of the egg and the cuticle of the female tick are approximately the same, in Argasidae the critical temperatures of the cuticle are much higher (62° C. in O. moubata). These differences are related to the physical properties of the waxes. The cuticular wax in O. moubata is hard and crystalline (m.p. 65° C), whereas the egg wax is soft and viscous (m.p. 50-54° C). 6. The natural wax from Géné's organ has definite powers of spreading on the surface of the egg and so completing the waterproofing layer. 7. The material extracted with boiling chloroform from egg-shells or from nymphal cuticles separates spontaneously into two fractions, a hard white wax (c. 85 per cent, by weight) and a soft yellow grease (c. 15 per cent.). The properties of these two lipoids differ conspicuously from those of the natural wax. Attempts to deposit the extracted materials on membranes in the form of a waterproofing layer were unsuccessful. 8. Ovulation is described in O. moubata. The shell of the tick egg is secreted by the oocyte itself and not by follicle cells. Three layers can be distinguished in the 24-hour egg: (i) an outer wax layer; (ii) an incomplete layer of granules which reduce ammoniacal silver nitrate; (iii) a shell layer. A fourth layer, the inner membrane (iv), is secreted by the oocyte after incubation for 2-3 days. 9. Both the shell layer and the inner membrane are composed of resistant, elastic protein and are devoid of chitin. The shell layer of the unwaterproofed egg is highly permeable to water and to large molecules with either hydrophilic or lipophilic affinities. The inner membrane is at first freely permeable to water and to inorganic ions. During the course of incubation the wax gradually migrates into the shell material and may reach the inner membrane. As this occurs, the effectiveness of abrasive dusts and of chloroform in promoting increased transpiration through the shell is notably reduced.

scholarly journals Using a two-layered sphere model to investigate the impact of gas vacuoles on the inherent optical properties of <i>Microcystis aeruginosa</i>

2013 ◽  
Vol 10 (12) ◽  
pp. 8139-8157 ◽  
Author(s):  
M. W. Matthews ◽  
S. Bernard
Keyword(s):  
Optical Properties ◽  
Microcystis Aeruginosa ◽  
Cyanobacterial Blooms ◽  
Shell Layer ◽  
Sphere Model ◽  
Homogeneous Population ◽  
Chl A ◽  
Inherent Optical Properties ◽  
Gas Vacuoles ◽  
The Impact

Abstract. A two-layered sphere model is used to investigate the impact of gas vacuoles on the inherent optical properties (IOPs) of the cyanophyte Microcystis aeruginosa. Enclosing a vacuole-like particle within a chromatoplasm shell layer significantly altered spectral scattering and increased backscattering. The two-layered sphere model reproduced features in the spectral attenuation and volume scattering function (VSF) that have previously been attributed to gas vacuoles. This suggests the model is good at least as a first approximation for investigating how gas vacuoles alter the IOPs. Measured Rrs was used to provide a range of values for the central value of the real refractive index, 1 + ε, for the shell layer using measured IOPs and a radiative transfer model. Sufficient optical closure was obtained for 1 + ε between 1.1 and 1.14, which had corresponding Chl a-specific phytoplankton backscattering, bbφ*, between 3.9 and 7.2 × 10−3 m2 mg−1 at 510 nm. The bbφ* values are in close agreement with the literature and in situ particulate backscattering measurements. Rrs simulated for a population of vacuolate cells was greatly enlarged relative to a homogeneous population. A sensitivity analysis of empirical algorithms for estimating Chl a in eutrophic/hypertrophic waters suggests these are robust under variable constituent concentrations and likely to be species-sensitive. The study confirms that gas vacuoles cause significant increase in backscattering and are responsible for the high Rrs values observed in buoyant cyanobacterial blooms. Gas vacuoles are therefore one of the most important bio-optical substructures influencing the IOPs in phytoplankton.

Construction of anatase@rutile core@shell TiO2 nanosheets with controllable shell layer thicknesses for enhanced ethanol sensing

2020 ◽  
Vol 325 ◽  
pp. 128815
Author(s):  
Jinniu Zhang ◽  
Chujun Chen ◽  
Hongbing Lu ◽  
Deying Leng ◽  
Gang Li ◽  
...  
Keyword(s):  
Core Shell ◽  
Shell Layer ◽  
Tio2 Nanosheets ◽  
Ethanol Sensing

scholarly journals Flame Die-out of Glued Laminated Japanese Larch Lumber Columns with a Fire-retardant Shell-layer

2008 ◽  
Vol 54 (3) ◽  
pp. 139-146 ◽  
Author(s):  
Toshiro Harada ◽  
Keisuke Ando ◽  
Masayuki Miyabayashi ◽  
Tomio Ohuchi ◽  
Keiichi Miyamoto ◽  
...  
Keyword(s):  
Fire Retardant ◽  
Japanese Larch ◽  
Shell Layer

scholarly journals Improved Photoresponse Characteristics of a ZnO-Based UV Photodetector by the Formation of an Amorphous SnO2 Shell Layer

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6124
Author(s):  
Junhyuk Yoo ◽  
Uijin Jung ◽  
Bomseumin Jung ◽  
Wenhu Shen ◽  
Jinsub Park
Keyword(s):  
Shell Structure ◽  
Rise Time ◽  
Zno Nanorods ◽  
Wide Bandgap ◽  
Core Shell ◽  
Shell Layer ◽  
Slow Response ◽  
Uv Photodetector ◽  
Zno Nanostructure ◽  
Core Shell Structure

Although ZnO nanostructure-based photodetectors feature a well-established system, they still present difficulties when being used in practical situations due to their slow response time. In this study, we report on how forming an amorphous SnO2 (a-SnO2) shell layer on ZnO nanorods (NRs) enhances the photoresponse speed of a ZnO-based UV photodetector (UV PD). Our suggested UV PD, consisting of a ZnO/a-SnO2 NRs core–shell structure, shows a rise time that is 26 times faster than a UV PD with bare ZnO NRs under 365 nm UV irradiation. In addition, the light responsivity of the ZnO/SnO2 NRs PD simultaneously increases by 3.1 times, which can be attributed to the passivation effects of the coated a-SnO2 shell layer. With a wide bandgap (~4.5 eV), the a-SnO2 shell layer can successfully suppress the oxygen-mediated process on the ZnO NRs surface, improving the photoresponse properties. Therefore, with a fast photoresponse speed and a low fabrication temperature, our as-synthesized, a-SnO2-coated ZnO core–shell structure qualifies as a candidate for ZnO-based PDs.

scholarly journals Manufacture and Strength Analysis of Ergonomic Bicycle Helmet Made from Polymeric Foam Composite Strengthened by Oil Palm Empty Fruit Bunch Fiber with Free Fall Drop Test Method

2020 ◽  
Vol 64 (1) ◽  
pp. 33-38
Author(s):  
Mahadi Mahadi ◽  
Keyword(s):  
Oil Palm ◽  
Free Fall ◽  
Product Safety ◽  
Drop Test ◽  
Empty Fruit Bunch ◽  
Test Results ◽  
Shell Layer ◽  
Bicycle Helmet ◽  
Polymeric Foam ◽  
Foam Composite

This article contains a study report on the manufacturing of bicycle helmet models that use polymeric foam composite materials strengthened by oil palm empty fruit bunch (OPEFB). The test results of mechanical polymeric foam obtain tensile stress (σt) 1.17 MPa, compressive stress (σc) 0.51 MPa, bending stress (σb) 3.94 MPa, modulus of elasticity (E) 37.97 MPa, density ( ρ) 193 (kg / m3). The testing results of thermal conductivity (k) with ASTM C177-04 standard obtain 0.096 W/mK. Aerodynamic simulation is carried out on 5 bicycle helmet models with different variations of air ventilation formations and obtained the M4A model that best met the ergonomic criteria. The simulation results of the M4A helmet model are max 65.668 Pa of air pressure (Pu), 26,8 0C of inner wall temperature (Ti), 11.0724 m/s of air velocity (vi) and 0.89 of drag coefficient (CD). Bicycle helmet manufacturing is carried out by hand lay up method for shell layer and casting mold for liner by using GFRP polymer composite molds. Both layers are made by sandwich method with the composition of the shell layer is 100 grams resin, 15 grams glass fiber and 5 grams catalyst. The composition of the liner layer is 275 grams (50%) of unsaturated Polyester 157 BQTN-EX resin, 27.5 grams (5%) of OPEFB fiber, 247 grams (45%) of Blowing Agent Polyurethane and 27.5 grams (5%) of Methyl Ketone Perokside catalyst (MEKPO). The toughness of the helmet is tested by using a free fall drop test with the standard of Consumer Product Safety Commission (CPSC) with the height of impact 1.5 meters. The free fall drop test results are max 2.02 MPa of the impact stress of the M4A bicycle helmet model (σi) and max 283.77 joules of energy impact (Ei) which is close to the Consumer Product Safety Commission’s (CPSC) standard value of 110 joules.

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