Shell Ratios Research Articles

Mercury Ion Selective Adsorption from Aqueous Solution Using Amino-Functionalized Magnetic Fe2O3/SiO2 Nanocomposite.

This study focuses on the development of new amino-functionalized magnetic Fe2O3/SiO2 nanocomposites with varying silicate shell ratios (1:0.5, 1:1, and 1:2) for the efficient elimination of Hg2+ ions found in solutions. The Fe2O3/SiO2-NH2 adsorbents were characterized for their structural, surface, and magnetic properties using various techniques, including Fourier transform infrared spectrum (FT-IR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Braunauer-Emmett-Teller (BET), thermogravimetric analysis (TGA), zeta-potential, and particle size measurement. We investigated the adsorption circumstances, such as pH, dosage of the adsorbent, and duration of adsorption. The pH value that yielded the best results was determined to be 5.0. The Fe2O3/SiO2-NH2 adsorbent with a silicate ratio of (1:2) exhibited the largest amount of adsorption capacity of 152.03 mg g-1. This can be attributed to its significantly large specific surface area of 100.1 m2 g-1, which surpasses that of other adsorbents. The adsorbent with amino functionalization demonstrated a strong affinity for Hg2+ ions due to the chemical interactions between the metal ions and the amino groups on the surface. The analysis of adsorption kinetics demonstrated that the adsorption outcomes adhere to the pseudo-second-order kinetic model. The study of adsorption isotherms revealed that the adsorption followed the Langmuir model, indicating that the adsorption of Hg2+ ions with the adsorbent occurred as a monomolecular layer adsorption process. Furthermore, the thermodynamic analyses revealed that the adsorption of Hg2+ ions using the adsorbent was characterized by a spontaneous and endothermic process. Additionally, the adsorbent has the ability to selectively extract mercury ions from a complex mixture of ions. The Fe2O3/SiO2-NH2 nanocomposite, which is loaded with metal, can be easily recovered from a water solution due to its magnetic properties. Moreover, it can be regenerated effortlessly through acid treatment. This study highlights the potential use of amino-functionalized Fe2O3/SiO2 magnetic nanoparticles as a highly efficient, reusable adsorbent for the removal of mercury ions from contaminated wastewater.

Preparation and performance evaluation of microencapsulated acid used for gel breaking of fracturing fluid in low-temperature reservoirs

In low-temperature reservoirs, the generation of free radicals by oxidizing breakers is challenging, and the alkaline fracturing fluid generally inhibits enzyme’s activity, making it difficult to break down the fracturing fluid. Previous studies have demonstrated that acids can consume borate ions and disrupt crosslinking nodes even at low temperatures, thereby efficiently breaking gels. Thus, microencapsulated oxalic acid (OA) was prepared via a coacervation method, using ethyl cellulose (EC) or acrylonitrile–butadiene–styrene (ABS) as shell materials with varying initiator viscosities and core–shell ratios. An optimal microcapsule MC[OA/ABS-2000-1:2] was determined based on the coating effect, productivity, encapsulation rate, and release performance. The test results of FT-IR and TGA together proved that the optimal microcapsule was composed of 24.4 and 74.8 % of OA and ABS, respectively. Scanning electron microscopy and laser particle size analysis were employed to characterize the optimal microcapsule with an average particle size of 402.8 μm, which exhibited a high degree of sphericity. Because of their porous shells, these microcapsules exhibited sustained slow-release characteristics. Evaluations conducted at temperatures of 30 and 50 ℃, simulating the tight sandstone reservoir conditions in the Ordos basin, revealed that delayed gel breaking could be achieved within approximately 2.5 h at low temperatures by adding only 0.25 % of the optimal microcapsule. Furthermore, increasing the temperature and dosage of microcapsules resulted in shorter breaking times. Additionally, a synergistic breaking effect was observed between the enzymes and the prepared microencapsulated acid. Thus, by optimizing the microcapsule dosage based on the reservoir temperature and fracturing construction pumping time, employing the two breakers together can achieve delayed and complete gel breaking at the desired time. In conclusion, the microencapsulated acid prepared in this study has significant potential as a gel breaker for fracturing fluids in low-temperature reservoirs.

Evaluation of the microcapsules on the rheological and self-healing performance of asphalt

The objective of this study was to prepare microcapsules and investigate their impact on the self-healing properties of asphalt. Microcapsules with various core–shell ratios were prepared by enveloping soybean oil with Melamine-Urea-Formaldehyde (MUF) resin through an in-situ polymerization method. The laser particle size analyzer, thermogravimetric analyzer, and scanning electron microscope were utilized to character the microcapsules and determined the optimal core–shell ratio. The rheological and self-healing performance of the microcapsule-modified asphalt were examined through frequency sweep, multi stress creep and recovery (MSCR), and Fatigue-Healing-Fatigue (F-H-F) tests conducted using a dynamic shear rheometer (DSR). The results indicate that microcapsules with various core–shell ratios exhibit uniform particle distribution and excellent thermal stability. Specifically, microcapsules with a core–shell ratio of 1:2 display a smooth appearance. The incorporation of microcapsules into asphalt impedes the flow of asphalt molecules and increases the initial flow temperature. When the microcapsules rupture, the released soybean oil modifies the rheological behavior of the asphalt, leading to a decrease in stress sensitivity and rutting resistance. Simultaneously, the remaining MUF resin imparts additional elastic recovery properties to the asphalt. The self-healing performance of microcapsule-modified asphalt was significantly enhanced, with a notable improvement observed as the microcapsule dosage increased. Moreover, elevating the healing temperature and extending the healing time were found to be effective strategies for enhancing the self-healing properties of microcapsule-modified asphalt. When the healing temperature matches the initial flow temperature, the healing index HI of 5% microcapsules modified asphalt approached nearly 100% within 5 min of healing time.

Magnetic Properties of Magnetoelectric Nanoparticles With Varying Core–Shell Ratios and Their Effects on In Vitro Neuron Stimulation

Magnetic Properties of Magnetoelectric Nanoparticles With Varying Core–Shell Ratios and Their Effects on In Vitro Neuron Stimulation

The co-combustion of pellets with pistachio shells in residential units additionally equipped by Pt-based catalyst

There are several published studies evaluating the possibilities of thermal and non-thermal utilization of pistachio hard shells in many technical sectors; however, there are no relevant data about the possibilities of usage of this homogenous biomass-based by-product as a fuel for automatic household heating appliances for partial or full substitution of standard ENplus A1 pellets, which is the aim of the presented study. The composition and basic properties of both fuels were compared as well as the flue gas composition formed during the 6 different fuel mixture combustion in two real-scale pellet burners. The mass concentration of observed pollutants (CO, total suspended particles, and C3H8) in the flue gas was strongly affected by increasing of pistachio shell mass fraction in the fuel mixture (from 10 to 100%). In comparison to the combustion of ENplus A1 pellets, CO was increased up to 25.9 times, total suspended particles up to 15.3 times, and C3H8 up to 13.7 times. Based on the results of real combustion tests, the equations were listed, describing the increase of the mass concentration of pollutants for the whole spectrum of pellets/pistachio shell ratios applied on the chosen designs of the pellet burners. The Pt-based oxidation honeycomb catalyst, additionally installed at the combustion unit outlets for flue gas purification, showed conversion rates up to 82.2% in the case of CO and up to 33.1% in the case of C3H8. This enables the reaching of the same or lower mass concentrations of mentioned pollutants in the flue gas, formed during the co-combustion of appropriately selected fuel ratios in comparison to ENplus A1 pellet combustion without the catalyst.

Atomic Simulations of Si@Ge and Ge@Si Nanowires for Mechanical and Thermal Properties

Molecular dynamics simulations using Tersoff potential were performed in order to study the evolution of the atomic packing structures, loading states on the atoms, and tensile tests, as well as the thermal properties of Si/Ge core–shell nanowires with different core–shell structures and ratios at different temperatures. Potential energy and pair distribution functions indicate the structural features of these nanowires at different temperatures. During uniaxial tensile testing along the wire axis at different temperatures, different stages including elasticity, plasticity, necking, and fractures are characterized through stress–strain curves, and Young’s modulus, as well as tensile strength, are obtained. The packing patterns and Lode–Nadai parameters reveal the deformation evolution and different distributions of loading states at different strains and temperatures. The simulation results indicate that as the temperature increases, elasticity during the stretching process becomes less apparent. Young’s modulus of the Si/Ge core–shell nanowires at room temperature show differences with changing core–shell ratios. In addition, the Lode–Nadai parameters and atomic level pressures show the differences of these atoms under compression or tension. Temperature and strain significantly affects the pressure distribution in these nanowires. The phonon density of states, when varying the composition and strain, suggest different vibration modes at room temperature. The heat capacities of these nanowires were also determined.

The Shell Matters: Self-Organized CdS-ZnS/MnS-Core-Shell—Porphyrin-Polymer Nano-Assemblies for Photocatalysis

A facile synthesis of catalytically tunable core-shell CdS-ZnxMn1-xS-nanoparticles in conjunction with poly(acrylic acid) (PAA) and porphyrin in an aqueous solution is described in the following: The shell composition of the inorganic nanoparticles is varied to tune the optical properties and to optimize the catalytic activity. Further, the tetravalent cationic 5,10,15,20-tetrakis(4-trimethylammoniophenyl) porphyrin (TAPP) fulfills a triple functionality in the catalyst: as a photosensitizer, as an electrostatic linker connecting the nanoparticles and as a probe to investigate the surface composition of the II-VI semiconducting nanoparticles. Different nanoparticles with varying zinc sulfide/manganese sulfide shell ratios are tested with regard to their photocatalytic behavior by crocin bleaching. The results reveal that the shell composition can be a crucial key to optimize the catalytic activity, which can further be important in tuning the reactivity of related systems. Fundamentally, the stepwise multi-component self-assembly in an aqueous solution has been demonstrated to allow the tuning of optic and catalytic properties of core-shell nanoparticles, a general concept that may be widely applicable.

Influence of the structure of sub‐micrometer core‐shell rubber particles and matrix composition on the mechanical properties, morphological structure and deformation mechanism of rubber‐modified polyphenylene oxide/polystyrene blends

AbstractA series of polybutadiene‐graft‐polystyrene (PB‐g‐PS) graft copolymers with different core–shell ratios (PB/PS) are synthesized using emulsion polymerization. Subsequently, the PB‐g‐PS graft copolymers are blended with polyphenylene oxide (PPO) and polystyrene (PS) to prepare PPO/PS/PB‐g‐PS blends with varying compositions. The effects of the core–shell ratio of PB‐g‐PS graft copolymer and matrix composition on the mechanical properties, micromorphology, and deformation mechanism of the blends are investigated. The results show that the synthesized PB‐g‐PS graft copolymer has extremely high toughening efficiency. The blends with high toughness and excellent processability can be prepared by introducing it and PS into PPO at the same time, and then obtain better end‐use properties and broaden the applications. With the increase of the core‐shell ratio of PB‐g‐PS graft copolymer, the rubber particles gradually gather in the matrix. With an increase of PPO content in the matrix, the rubber particles gradually become uniformly dispersed, the impact strength and yield strength of the blends gradually increase, the coarseness of the impact fracture surface of the blends gradually increase, and massive elongated cavities appear. The blends undergo a brittle ductile transition, and its deformation mechanism change from the initial cracking to shear yielding.

Survival of Hydroxyapatite-Coated Versus Non-hydroxyapatite-Coated Total Hip Arthroplasty Implants in a Veteran Population.

Hydroxyapatite (HA) coatings were introduced to improve uncemented implant osteointegration and to prevent loosening and osteolysis. However, data regarding these implants have been inconsistent. We studied the effect of HA coating of femoral stems and acetabular cups on component revision after primary total hip arthroplasty (THA) in the veteran population. We identified patients who underwent uncemented primary THA at any Veterans Health Administration (VHA) hospital from 2000 to 2017 and who had implants that were available as either HA-coated or non-HA-coated models. The endpoint was removal of the component of interest for any reason. For each individual stem and shell, unadjusted and adjusted (for age and body mass index) Cox proportional hazards models were used to estimate hazard ratios for the risk of explantation between HA-coated and non-HA-coated implants of the same type. A total of 262 HA-coated cups, 4580 non-HA-coated cups, 4767 HA-coated stems, and 9397 non-HA-coated stems were available for analysis. The mean follow-up time was 9.01 years (43,627 total implant-years) for cups and 7.13 years (101,004 total implant-years) for stems. One of the two shells reviewed had significantly lower survivorship and an elevated hazard ratio for explantation with HA coating. Among the five implant pairs of stems, and the other shell, implant survival and hazard ratios for explantation were not affected by HA coating. HA coating did not improve THA implant survival in our veteran population. Although HA-coated versions of hip implants tend to be more costly than their noncoated counterparts, these results do not support their general use.

Study of the Thermoelectric Properties of Bi2Te3/Sb2Te3 Core-Shell Heterojunction Nanostructures.

Thermoelectric materials convert heat energy into electricity, hold promising capabilities for energy waste harvesting, and may be the future of sustainable energy utilization. In this work, we successfully synthesized core-shell Bi2Te3/Sb2Te3 (BTST) nanostructured heterojunctions via a two-step solution route. Samples with different Bi2Te3 core to Sb2Te3 shell ratios could be synthesized by controlling the reaction precursors. Scanning electron microscopy images show well-defined hexagonal nanoplates and the distinct interfaces between Bi2Te3 and Sb2Te3. The similarity of the area ratios with the precursor ratios indicates that the growth of the Sb2Te3 shell mostly took place on the lateral direction rather than the vertical. Transmission electron microscopy revealed the crystalline nature of the as-synthesized Bi2Te3 core and Sb2Te3 shell. Energy-dispersive X-ray spectroscopy verified the lateral growth of a Sb2Te3 shell on the Bi2Te3 core. Thermoelectric properties were measured on pellets obtained from powders via spark plasma sintering with two different directions, in-plane and out-of-plane, showing anisotropic properties due to the nanostructure alignment in the pellets. All samples showed a degenerate semiconducting character with the electrical resistivity increasing with the temperature. Starting from Sb2Te3, the electrical resistivity increases with the increase in amounts of Bi2Te3. Thermal conductivity is lowered due to the increase in interfaces and additional phonon scattering. We show that the out-of-plane direction of the BTST 1-3 sample (where 1-3 indicates the ratio of BT to ST) demonstrates a high Seebeck value of 145 μV/K at 500 K which may be attributed to an energy filtering effect across the heterojunction interfaces. The highest overall zT is observed for the BTST 1-3 sample in the out-of-plane direction at 500 K. The zT values increase continuously over the measured temperature range, indicating a probable higher value at increased temperatures.

The Effect of Different Soft Core/Hard Shell Ratios on the Coating Performance of Acrylic Copolymer Latexes.

Core–shell acrylic copolymer latexes containing bio resourced itaconic acid with different compositions in respect with the core and shell segments were synthesized, characterized, and applied as coating materials for leather. The purpose of the study was to evidence the high coating performance of the latexes when the ratio of the core/shell differed from 90/10 to 50/50 wt %. The copolymers were prepared via emulsion copolymerization technique and the products were isolated and characterized by means of structure identity, thermal behavior (DSC and DMTA), coating performance. The particle size of the latexes varied from 83 to 173 nm with the variation of the ratio of core/shell segments. The influence of the composition of soft part and hard part was highlighted in the thermal and coating properties. The optimal composition giving the best coating performance could be determined as DS 60/40. Further increase of the hard segment content, resulted in decreased emulsion stability and the coating performance on the leathers. The use of itaconic acid seemed to increase the emulsion stability as well the adhesion of the latexes to the substrate.

Nanostructured nickel sulphate: properties and applications in marmalade production

The paper presents the data on the use of nanostructured nickel sulfate in the production of marmalade as a functional food product for prophylactic purposes. The nanoparticle tracking analysis (NTA method) was used to determine the size of nanostructured nickel sulfate. In this case, the smallest size (25.7 nm) is formed only in gellan gum with a core:shell ratio of 1:1. When the core:shell ratio in gellan gum is 1:3, the average size of nanocapsules is 49.9 nm. This result can be explained by the tighter packing of cobalt sulfate in the capsule. In sodium alginate, the average nanocapsule size is already 191 nm. The polydispersity index in all studied shells and at different core:shell ratios are practically equal and amounts to 0.84–1.09, which corresponds to a spherical shape.

Shell morphometric ratios as a tool for taxonomic determination in gastropods: a case study inNerita(Gastropoda, Neritidae)

AbstractIn the study, we compare the shell shape morphometrics in four species of neritid gastropods (Nerita fulgurans,Nerita tessellata,Nerita pelorontaandNerita versicolor), collected in Accra Beach (Barbados Island). We tested the hypothesis that the morphometric ratios can be used as a tool in the taxonomic determination among these four species of neritids. For this we determine the morphometric ratios from the external (length, height, width) and internal (shell aperture length, shell aperture width) measures. A principal component analysis (PCA) was used to determine which ratios were significant, and subsequently the proposed hypothesis was tested using the Kruskal–Wallis test. The morphometric ratios AW/H and AL/L were decisive in distinguishing the four species of neritids studied. In this study, the hypothesis of the efficacy of the use of shell morphometric ratios as an instrument in taxonomic studies was corroborated for the four species. Due to its low cost, this methodology can be applied in the recognition of species that have lost their external characteristics such as operculum, spire or colour and also in the identification of fossil specimens.

Effect of Microcapsules of a Waterborne Core Material on the Properties of a Waterborne Primer Coating on a Wooden Surface

Microcapsules of a waterborne core material were prepared using a waterborne primer. The microcapsules of the waterborne core material were added to the waterborne primer to explore the effects of different core–shell ratios and mass fractions of the microcapsules on the property of the waterborne primer coating on the wooden surface. The results show that as the mass fraction of the microcapsules increased, the chromatic aberration increased by degrees, the glossiness decreased gradually, and the hardness increased by degrees, whilst—except for the coating with 0.50:1 microcapsules—the adhesion decreased gradually. When the mass fraction of the microcapsules increased, the impact resistance increased first and decreased later, or remained unchanged after reaching a certain value. When the mass fraction of the microcapsules increased, the elongation at the break increased first and decreased later. When the core–shell ratio was small and the mass fraction was between 5.0% and 15.0%, the coating had better liquid resistance. When the core–shell ratio was 0.67:1 and the mass fraction was 10.0%, the overall property of the coating on the Basswood was the best. The technology of microencapsulation provides a technical reference for the waterborne primer with self-repair qualities on the surface of wooden products.

A new shear deformation shell theory for free vibration analysis of FG sandwich shells

In recent years, many researches have been published dealing with the mechanical responses of shells with variable cross-sectional mechanical properties such as sandwich, functionally graded and laminated composites shells. In the present paper, a simple and efficient shear deformation theory is formulated for the free vibration response of functionally graded sandwich shells. The main advantage of this theory is its reduced number of unknowns and their related governing equations and theses tend to be highly compared to others shear deformation shell theories. Two kinds of FG sandwich shells are studied with respect to their geometrical configuration and material properties. The first kind is composed of FG facesheet and homogeneous core and the other is formed by homogeneous facesheet and FG core. The governing equations of motion for the free vibration analysis are obtained using Hamilton's principle. The closed form solutions are sought by using the Navier's method for eigenvalue problems. The accuracy and efficiency of the present theory are established and proved by comparing obtained numerical results with those predicted by other higher order shear deformation shell theories. The influences of various parameters such as material distribution, thickness of the core and the facesheet of sandwich shell and curvature ratios are studied, discussed and reported as significant rate sensitivity to predict the fundamental frequencies of FG sandwich shells.

Free-choice Feeding of Three Different Dietary Calcium Sources and their Influence on Egg Quality Parameters of Commercial Layers

Purpose: The study reported herein was conducted to determine the effects of choice feeding three different calcium (Ca) sources on external and internal egg quality parameters of commercial layers. Research Method: Three dietary Ca sources (oyster shells, limestone and bone meal) were choice fed ad libitumly along with a commercial layer feed. The birds fed only the commercial layer diet was used as the control. The experiment was conducted as a complete randomized design. A total of 128, 55 weeks old Hy-line white layer hens (1500 ±21g) were assigned into 16 cages of 8 birds each. Four replicate cages were randomly assigned to each of the four dietary treatments. Bird’s performances were tested weekly. Twenty eggs from each treatment were collected weekly over five weeks period and were assessed for shell and internal quality parameters. Findings: Daily Ca intakes of birds affected significantly (P<0.05) by the Ca source. The birds fed oyster shells and limestone showed the highest (P<0.05) daily Ca intakes. Feeding bone meal significantly (P<0.05) reduced damaged shell percentage. Weekly body weight gain, weekly egg production and feed conversion ratio among treatments were similar (P>0.05). Dietary supplementation of Ca significantly (P<0.05) improved the egg weight. Shape index and shell ratios among treatments were similar (P>0.05). Feeding bone meal significantly (P<0.05) improved unit surface shell weight (USSW) and the shell thickness. Calcium supplementation had no effect (P>0.05) on albumen and yolk quality parameters of eggs. Originality/value: The present study concluded that feeding bone meal to commercial layers improves USSW, shell thickness thereby reducing egg damages. Calcium source has no influence in improving internal quality parameters of chicken eggs.

Electronic and optical properties of GaN/AlN core–shell nanowires

The electronic and optical properties of GaN/AlN core–shell nanowires (NWs) with different core–shell ratios are studied by means of density functional theory (DFT). The results show that as the GaN core structure increases (the AlN shell remains unchanged), the band gap of NWs decreases. In contrast, with the increase of AlN shell (GaN nucleus remains unchanged), the band gap almost remains unchanged. That is to say the adjustment capability of core–shell ratio for the band gap of GaN/AlN core–shell NWs with the same diameter of GaN core degenerates, and the band gap of which are mainly controlled by GaN core. Ga–N bond and Al–N bond show a strong ionic property because of the electronegativity of N is strong over Ga and Al. In addition, the calculated results of the real part [Formula: see text] and the imaginary parts [Formula: see text] with photon energy indicate that the storage capability and loss of the NWs to electric field energy are different with the content of AlN. The four structured NWs reflect electromagnetic waves as conductor in a high frequency ultraviolet range. The results are valuable for the design of GaN/AlN core–shell NWs optoelectronic nanodevices and the research of other core–shell NWs heterostructures.

Deoxygenation of pyrolysis vapour derived from durian shell using catalysts prepared from industrial wastes rich in Ca, Fe, Si and Al

Catalysts prepared from industrial wastes rich in Fe, Ca, Si, and Al were used in catalytic upgrading of pyrolysis vapour derived from durian shell and their effect on product yield and properties were compared. With same silica-to-alumina ratio, catalyst prepared from oil palm ash (AS-OPA) with lower Fe and Ca contents gave higher liquid yield (8.32 wt%) with alcohols (28.90%), hydrocarbons (46.00%), and nitrogen-containing compounds (21.46%) while catalyst prepared from electric arc furnace slag (AS-EAF) with higher Fe and Ca contents produced lower liquid yield (50.21 wt%) with high amount of esters (25.80%) and hydrocarbons (72.82%). The presence of AS-OPA and AS-EAF catalysts enhanced deoxygenation degree of bio-oil to 81.13% and 85.49%, respectively. The catalytic performance of AS-EAF at different temperatures (400–600 °C) and AS-EAF/durian shell ratios (1:30, 2:30, 3:30) was investigated. Increasing catalytic temperature enhanced production of bio-oil, reduced oxygenates and enhanced formation of esters. The liquid yield and yield of esters decreased with increasing catalyst loading. Hydrocarbons (mainly neopentane) were the major chemical compounds found in bio-oil produced over AS-EAF. Besides that, AS-EAF showed good deoxygenation performance with highest selectivity of hydrocarbons at 500 °C and AS-EAF/durian shell ratio of 2:30. Catalytic fast pyrolysis of durian shell using waste-derived catalysts is an effective waste management strategy as the bio-oil produced can be a potential alternative source of energy or chemical feedstocks.

Evaluation of some engineering properties of cucumber (Cucumis sativus L.) seeds and kernels based on image processing

In this study, a method based on digital image processing was employed to investigate effect of the moisture content on gravimetrical and frictional properties of the cucumber seeds and kernels. This research indicated that the application of visual machines and the image processing could be a rapid method that enables accurate measurement of the dimensional parameters of two varieties of this product meticulously. The length, width, and thickness of the seeds of Rashid variety ranged from 6.40 to 9.07, 2.91 to 4.21 and 0.65 to1.50mm, respectively; the corresponding value of Negin variety ranged from 6.89 to 9.07, 2.49 to 4.21, and 0.69 to 1.68mm, respectively. Kernel and shell ratios of the Rashid variety were found to be 69.811 and 30.189%, respectively; the corresponding values of the Negin variety were found to be 72.727 and 27.273%, respectively. Despite the bulk densities of the two varieties of cucumber seeds and kernels that decreased with the moisture content, true density and porosity of the two varieties of cucumber seeds and kernels increased. As the moisture content increased from 5.04 to 21.12% (d.b), the angle of the static friction of the seeds of Negin variety increased from 30.39° to 37.18°, 28.83° to 34.99°, 24.37° to 30.04°, and 15.77° to 19.57° for wood, rubber, iron, and galvanized, respectively,; the corresponding value of the Negin variety increased from 21.12° to 27.16°, 24.43° to 31.41°, 19.90° to 25.59° and 14.09° to 18.12° as the moisture content increased from 5.02 to 21.02% (d.b).

New insights into the impact toughness of ASA (acrylonitrile-styrene-acrylate) with controllable core–shell structure synthesized by three-stage seeded emulsion polymerization

ABSTRACTAcrylonitrile-styrene-acrylate (ASA) with controllable core–shell structure was prepared through three-stage seeded emulsion polymerization. A series of characterizations had been performed to study the effect of different core–shell ratios on the properties of ASA. The most interesting was that the impact strength of ASA exhibited a “wave” variation instead of a linear variation with the increasing loading content of poly(butyl acrylate) (PBA) core. Moreover, the threshold of impact strength appeared at 49.725 wt% PBA content, nearly 33 kJ/m2. To explain this unusual variation, an impact schematic was proposed.