Breakage Resistance Research Articles

Optimization Design and Experimental Analysis of Resistance-Reducing Anti-Fracture Rotary Blade Based on DEM Techniques

To address the significant cutting resistance and fracture susceptibility of rotary blades, an innovative blade design was conceived to minimize resistance and enhance fracture resistance. By analyzing the interaction between the blade, soil, and root systems, an optimized design for the blade structure’s breakage resistance was developed. The theory of eccentric circular side cutting edges was applied to redesign the curve of the side cutting edge, and kinematic analysis was conducted to determine the optimal edge angle (26.57°). A flexible body model of corn residues was established, and cutting resistance measurements indicated a 15.1% reduction in cutting resistance. The breakage resistance of the rotary blade was validated using a discrete element method–finite element method (DEM–FEM) coupling approach. The results demonstrated the following: neck stress (−16.85%), specific strength efficiency (+9.72%), specific stiffness efficiency (+9.78%), fatigue life (+39.08%), and ultimate fracture stress (+20.16%), thereby meeting the design objectives. The comparison between field trial results and simulation data showed an error rate (<5%), confirming the simulation test’s feasibility. These findings provide theoretical references for reducing cutting resistance and enhancing breakage resistance in rotary blades.

A stepped vibrating screening device with a crushing function based on the difference in tuber-soil aggregate breakage behaviour

To increase the difference in the particle size distribution of root tuber and soil aggregates and further promote the segregation effect of the binary mixture under external force. The present study investigates the bulbs of Fritillaria thunbergii (BFT) as the research subject. Initially, static compression and dynamic impact tests were conducted on BFT and soil aggregates. Subsequently, a breakage model of BFT and soil aggregates was established based on the Tavares UFRJ Breakage Model, and the accuracy of the breakage model and mechanical parameters was verified. Lastly, the optimal structural and operating parameters of the screening device with a crushing function were determined through single-factor testing and multi-objective optimization. The results indicate that the breakage resistance of BFT was significantly higher than that of soil aggregates, as evident from the differences in fracture energy and damage parameters. Furthermore, the optimal operating parameters of the new vibrating screen were determined by maximizing the soil aggregate breakage rate and minimizing the BFT breakage rate.

Experimental and numerical analyses of crushing resistance of unbound road materials

ABSTRACT Aggregate breakage in unbound pavement layers can lead to pavement distresses that affect their functionality and service life. Thus understanding the mechanics and clarifying the factors affecting materials breakage resistance are important for ensuring adequate performance of these layers. In this study, aggregate breakage in unbound granular materials (UGM) is investigated experimentally and numerically. Experimentally, aggregate breakage under uniaxial compression is examined for two UGMs prepared with the same aggregate type but different gradations. To capture the experimentally observed influence of gradation and load magnitude on aggregate breakage, a Discrete Element Method (DEM) model was developed, based on granular mechanics particle contact and failure laws. A simple procedure to identify the contact and failure law parameters from experiments is proposed. With those parameters, the model’s capability of capturing the effect of gradation and loading on the aggregate breakage in UGM is evaluated. Based on comparison with experimental findings, it is shown that the model can capture macro-scale properties of UGM, such as its deformation response under uniaxial compression, as well as the amount of aggregate breakage in the material.

A comprehensive investigation on the structural transformation and dissolution loss reaction of coke during gasification in CO2 atmosphere

The in-situ investigation of the structural transformation of coke during gasification can provide useful insights into its dissolution loss reaction in blast furnaces. In this study, the structural properties of coke are evaluated by analyzing its carbon matrix, pore distribution, and ash composition using scanning electron microscopy (SEM), wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), Raman spectroscopy, mercury intrusion porosimetry (MIP), and X-ray fluorescence (XRF) spectrometry. The pore evolution and carbon structural transformation during gasification in CO2 atmosphere are analyzed in-situ using synchrotron radiation SAXS-WAXS techniques for three coke samples prepared from coals with varying ranks. The strength and reactivity of coke are assessed based on its structure and dissolution-loss reaction mechanism during gasification. The results indicate that the high breakage resistance index (M13) of coke is attributed to the interlocking of bent aromatic carbon layers with AD/AG less than 1.837. The amorphous structures characterized by A(VL+VR+SL+S)/AD higher than 0.935 in coke serve as the initiation site of reaction with CO2, leading to a decrease in the fractal dimension (DS) and interlayer spacing (d002) as well as an increase in the stacking width (La). Subsequently, the etching of the carbon microcrystals and the dissolution loss of defective carbon structures alternately occur during gasification. The rough pore surface with DS more than 2.91 hinders the CO2 diffusion, while the carbon matrix with AD/AG more than 2.269 effectively decreases the coke reactivity index (CRI) of coke. Overall, the findings of this study can offer a theoretical foundation for coke quality evaluation and effective optimization of iron-making processes.

An overview for materials and design methods used for enhancement of laminated glass

The attachment of more than one glass layer through the polymeric interlayer results in the formation of laminated glass. In contrast to other glass types, laminated glass offers better breakage resistance, post-breakage safety, and protection against noise. The breakage resistance and post-breakage safety of laminated glass in residential and commercial buildings hold critical prominence and laminated glass sustainability is being investigated in academia and industry. This study conducts a survey of the literature to identify and discuss various materials and design approaches incorporated to augment the sustainability of laminated glass. The mechanical properties augmentation of the laminated glass through material incorporation has been studied. Similarly, the safety and sustainability augmentation through Finite Element (FE) analysis has also been reviewed. This study considers various simulations of the impact and blast loading on laminated glass through FE models. The material and FE design revelations of this study will impart practical insights into laminated glass sustainability augmentation approaches.

14‐3: Drop Resistance Optimization Through Post‐Hoc Analysis of Chemically Strengthened Glass

In the market of the mobile cover glass, the development of chemically strengthened glass is focused on the drop resistance improvement. The cover glass which protects the display panel is a typical brittle material that the micro cracks tends to be occurred underneath a glass surface by physical impacts. The micro cracks tends to be propagated by tensile stress and it is known as a general procedures on glass breakage. In purpose of the cover glass strength improvement, compressive stress is applied to the glass surface using chemical strengthening method by ion exchange. However, since the central area of the glass is relatively subjected to tensile stress, the glass is instantly broken when the propagated cracks are reached on the tensile stress exerted area. The glass specifications have been managed for maintaining the strength using parameters of compressive stress (CS), depth of compression (DOC), and central tension (CT). However, there was no method to judge the most effective factor for impact drop resistance. In order to solve this problem, we developed a machine learning program for cover glass that can predict the breakage height based on stress and mapped evaluation data based on the measured stress profile data and the actual drop breakage simulated evaluation. Especially, eXplainable AI (XAI) method is used to identify the effective factors on drop breakage height. And the test and measurement data were applied to various chemically strengthened glass for analysis.In this study, it was possible to predict the drop breakage height only by measuring the stress profile of chemically strengthened glass. The feature value of chemically strengthened that has the most effect on the drop breakage resistance on rough surfaces was identified to be stress value at 30um in the case of alkali aluminosilicate glass. And it was proved that the drop breakage height was improved by 25% only by increasing the compressive stress at 30um depth.

Investigation of rice performance characteristics: A comparative study of LR, ANN, and RSM.

Parboiling is a type of heat pretreatment used in rice processing to reach higher head rice yield and improve the nutrition properties of raw rice. In this research, the goals were prediction and determination of optimum conditions for parboiled rice processing using the response surface method (RSM) as well as modeling the output values by linear regression (LR) and artificial neural networks (ANN). The parameters including steaming time (0, 5, 10, and 15 min), dryer type (solar and continuous dryers), and drying air temperature (35, 40, and 45°C) were employed as input values. In addition, the breakage resistance (BR) and head rice yield (HRY) were selected as output values. The ANN‐based nonlinear regression, the multi‐layer perceptron (MLP), and the radial basis function (RBF) have been developed to model the process parameters, as well as the central composite design (CCD) was conducted for optimization of BR and HRY values. The outputs of RBF network have been successfully applied to predict higher coefficient of determination of BR and HRY as 0.989 and 0.986, respectively, indicating the appropriateness of the model equation in predicting head rice yield and breakage resistance when the three processing variables (steaming time, dryer type, and drying air temperature) are mathematically combined. Also, the lower root mean square error (RMSE) was obtained for each one as 0.043 and 0.041. The optimum values of BR and HRY were obtained as 12.80 N and 67.3%, respectively, at 9.62 min and 36.9°C for a solar dryer with a desirability of 0.941. In addition, the same values were obtained as 14.50 N and 72.1%, respectively, at 8.77 min and 37.0°C for a continuous dryer with a desirability of 0.971.

The comparison of cyclic fatigue resistance of two different reciprocal files according to different access angles into the root canal

Aim: Root canal preparation is one of the most important steps of root canal treatment. Preparation procedure includes disinfection and shaping protocols. Ni-Ti rotary file systems are usually used for shaping. The biggest disadvantage of the usage of Ni-Ti rotary file systems is that the file gets broken during the treatment. There are many reasons for the breakage of files. One of the reasons may be the increase in the access angle. The purpose of this study is to compare the cyclic fatigue of reciprocating Reciproc and WaveOne Gold rotary systems according to different angles of accessing the root canal of Ni-Ti files.
 Methodology: In our study, 90 root canal files were used, 45 of which is Reciproc R25 (VDW GmbH, Munich, Germany) and the other 45 of which is WaveOne Gold Primary 25/07 (Dentsply, Maillefer, Ballaigues, Switzerland). Specially designed and manufactured stainless steel artificial roots whose curvature angle is 60° and curvature radius is 5 mm, which replicates the clinical conditions, were arranged. By enabling the files access the roots at 0°- 15°- 30° degrees, the lap numbers that they do till they break due to cyclic fatigue were examined.
 Results: When looking at the lap numbers that the Reciproc and WaveOne Gold root canal files do till they break, at accessing the roots at the same angles WaveOne Gold root canal file makes more lap numbers at all angles when compared with the Reciproc root canal file. Significant results were found when the groups were compared within one another and between groups and among all numeric data in the statistical analysis performed. It was also found that WaveOne Gold root canal file had more cyclic fatigue resistance. When the groups were compared within one another, it was found that the increase in the root access angle decreases the cyclic fatigue resistance of the files (p<0.05). No significant difference was found in the statistical analysis for comparison of the length of the broken file pieces (p=0.01). It was analyzed that when the broken files were examined via scanning electron microscope, file breakages occurred due to cyclic fatigue.
 Conclusion: Not only do the design features and production technology affect the breakage resistance due to cyclic fatigue of the root canal, the access angle to the roots affects the cyclic fatigue of the root canal files, as well.
 
 How to cite this article: Adıgüzel Ö, Dundar M, Kaya S. The comparison of cyclic fatigue resistance of two different reciprocal files according to different entry angles into the root canal. Int Dent Res 2021;11(Suppl.1):114-21. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.18
 
 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Removal of Toxic Phenolic Compounds from Wastewater Using Zeolite (4A) Prepared from Local Clays Taken from the Slopes of the Tigris River

The massive scale of industrial development has resulted in environmental pollution in general and water contamination in particular. It is important at the present time to treat water for the purpose of eliminating or reducing pollutants, especially toxic pollutants, such as phenol compounds. In this study, zeolite (4A) was prepared firstly from the available and cheap materials using an inclined rotary disk. Then, physical, mechanical, and chemical properties were also studied. Experiments were conducted to determine these properties using local clay and the following results were obtained: Zeolite (4A) 70% and clay 30%, the time of calcination 3 h at a temperature of 850��C, breakage resistance of 17 Ib pounds, surface area 530-590 m2/g, grinding value 14% and moisture absorption ratio 30%. The prepared zeolite (4A) was used in the process of removing phenolic compounds (chlorophenol, nitrophenol) by the adsorption method. Different amounts of prepared zeolite (5g/l and 10g/L) will be used in the treatment process and different concentrations (2mg/L, 5 mg/L and 10 mg/L) of the pollutants Nitrophenol and Chlorophenol were used in the contaminated water tested. The removal process was carried out with a mixing speed of 200 rpm and pH (7.5-8.5). From the results of this study, we note that the highest percentage of Nitrophenol removal is (84.8%) when using an amount of zeolite (5g) and highest percentage of Nitrophenol removal is (95.5%) when using an amount of zeolite (10g) while that the highest percentage of Chlorophenol removal is (78.3%) when using an amount of zeolite (5g) and highest percentage of Chlorophenol removal is (0.894) when using an amount of zeolite (10g) it could be deduced that the percentage of the removal of nitrophenol was higher than that of chlorophenol because its solubility of chlorophenol in water is higher than the solubility of Nitrophenol.

Preventing nickel-titanium rotary instrument from breakage by continuous irrigation with different fluids during root canal preparation.

To study the effect of continuous irrigation of rotating nickel-titanium instrument with several common clinical fluids on the diameter, breaking length and breaking position of nickel-titanium instrument, so as to provide some reference and theoretical basis for clinical operation and instrument improvement.A standardized curved root canal model was established, and ProTaper Universal (PTU) F1 instrument was selected for root canal preparation. The nickel-titanium F1 instrument was flushed with distilled water, 0.9% NaCl, 0.2% chlorhexidine, 1% sodium hypochlorite and 5% sodium hypochlorite, and the diameter, length and position of the instrument before and after breakage were recorded.Only 5% sodium hypochlorite influenced the diameter of 6 mm marker points under different irrigation conditions (P < .05). There was no statistical difference in the length of broken instruments among all the groups, and torsional deformation mainly occurred at the end of broken instruments. The broken positions of instruments in all the groups were located at the bending segment of the root canal. The breaking frequency of the 5% sodium hypochlorite group was the highest in the area 3–5.5 mm away from apical foramen, while the other 4 groups had the highest breaking frequency in the area 0 to 1.5 mm away from apical foramen.External irrigation with different fluids did not influence the breaking length of instruments. The closer to the apical foramen was, the higher the breaking frequency of instruments was. However, only 5% sodium hypochlorite can affect the diameter of rotary nickel-titanium instruments, and may lead to early breakage of the instrument, indicating that the use of disinfectants, except 5% sodium hypochlorite, cannot reduce breakage resistance of nickel-titanium instrument compared with distilled water flushing. Furthermore, 5% hypochlorite could not be recommended for irrigation in clinical practice.

Homogeneously Emitting, Mechanically Stable, and Efficient fs-Laser-Machined Fiber Diffusers for Medical Applications.

Light delivery is an essential part of therapy forms like photodynamic therapy (PDT), laser-induced thermotherapy, and endovenous laser therapy. While there are approaches to the light application for all three therapies, there is no diffuser that can be used for all three approaches. This diffuser must meet the following criteria: Homogeneous radiation profile over a length of 40 mm, efficient light extraction in the diffuser area, mechanical breakage resistance as well as thermal stability when applying high power. An ultrashort pulse laser was used to inscribe inhomogeneities into the core of a fused-silica fiber core while scanning the laser focus within a linear arrangement of cuboids centered around the fiber axis. The manufactured diffuser was optically and mechanically characterized and examined to determine the maximum power that can be applied in a tissue environment. Based on the analysis of all examined diffusers, the manufactured diffuser exhibits an emission efficiency ε = (81.5 ± 5.9)%, an intensity variability of (19 ± 5)% between distal and proximal diffuser end, and a minimum bending radius Rb = (15.4 ± 1.5) mm. It was taken advantage of the fact that the outer areas of the fiber core do not undergo any structural changes due to the machining and therefore do not suffer a major loss of stability. Tissue experiments revealed that a maximal power of 15 W was deliverable from the diffuser without harming the diffuser itself. It could be shown that a diffuser manufactured by ultrafast-laser processing can be used for low power applications as well as for high power applications. Further tests have to show whether the mechanical stability is still maintained after the application of high power in a tissue environment. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Effect of feldspar milling on the properties of low-density ceramic proppants

ABSTRACT Low-density and high-strength ceramic proppants were successfully prepared from bauxite and feldspar. The addition of feldspar greatly reduced the sintering temperature (below 1300℃). The effects of the particle size of feldspar on the bulk density, apparent density and breakage ratio of the proppants were evaluated. The morphology and phase composition of the proppants was examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that the ball milling of feldspar can greatly improve the properties of ceramic proppants. The phases of the proppants obtained contain mullite and corundum. Bulk density, apparent density, and breakage resistance of the proppants sintered at 1280℃ increase with the prolongation of ball milling time of feldspar. When the feldspar are milled for 6 h, bulk density of the proppants is 1.46 g/cm3, apparent density is 2.70 g/cm3 and breakage ratio under 52 MPa closed pressure is 7.97%.

Kernel crack characteristics for X-ray computed microtomography (μCT) and their relationship with the breakage rate of maize varieties

The most significant problem of maize grain mechanical harvesting quality in China at present is the high grain breakage rate (BR). BR is often the key characteristic that is measured to select hybrids desirable for mechanical grain harvesting. However, conventional BR evaluation and measurement methods have challenges and limitations. Microstructural crack parameters evaluation of maize kernel is of great importance to BR. In this connection, X-ray computed microtomography (μ-CT) has proven to be a quite useful method for the assessment of microstructure, as it provides important microstructural parameters, such as object volume, surface, surface/volume ratio, number of closed pores, and others. X-ray computed microtomography is a non-destructive technique that enables the reuse of samples already measured and also yields bidimensional (2D) cross-sectional images of the sample as well as volume rendering. In this paper, six different maize hybrid genotypes are used as materials, and the BR of the maize kernels of each variety is tested in the field mechanical grain harvesting, and the BR is used as an index for evaluating the breakage resistance of the variety. The crack characteristic parameters of kernel were detected by X-ray micro-computed tomography, and the relationship between the BR and the kernel crack characteristics was analyzed by stepwise regression analysis. Establishing a relationship between crack characteristic parameters and BR of maize is vital for judging breakage resistance. The results of stepwise multiple linear regression (MLR) showed that the crack characteristics of the object surface, number of closed pores, surface of closed pores, and closed porosity percent were significantly correlated to the BR of field mechanical grain harvesting, with the standard partial regression coefficients of −0.998, −0.988, −0.999, and −0.998, respectively. The R2 of this model was 0.999. Results validation showed that the Stepwise MLR Model could well predict the BR of maize based on these four variables.

Evaluation of grain breakage sensitivity of maize varieties mechanically-harvested by combine harvester

A high grain breakage rate is the main problem that occurs during mechanical maize harvest in China. The breakage sensitivity of different varieties was significantly different, and the breakage resistance is heritable. Therefore, breakage resistant variety screening can help improve the field production efficiency and provide references for breeding work. In this study, 42 varieties of maize were harvested with the same mechanical parameters and the same manipulator on a range of harvest dates at experimental stations in Xinxiang, Henan Province, in 2017 and Changji, Xinjiang Province, in 2018 to determine the sensitivity of grain moisture content on grain breakage rate during machine harvest for different varieties. The integral value of the grain breakage rate curve corresponding to the range of 15% to 30% grain moisture content was used as an index that expressed the sensitivity of maize grains to breakage depending on grain moisture content (BSW). Forty-two varieties were categorized as having weak, intermediate, or strong BSW. Among the same four varieties in the two stations, Lianchuang 825 and Lianchuang 808 were classified as sensitive and fragile varieties, Shandan 650 was classified as an intermediate variety, Zeyu 8911 was divided into weak sensitive and breakage-resistance varieties in Xinxiang and intermediate varieties in Changji. The BSW classification results at the two experimental sites were generally consistent, indicating that breakage sensitivity due to moisture content may be a relatively stable genetic characteristic. This study suggested that the integral method for determining BSW can be used to assess the resistance of different maize varieties to grain breakage during mechanical harvesting. The integral method was used to identify twelve breakage-resistant varieties in Xinxiang Station, and six breakage-resistant varieties in Changji Station. This study provides a method for screening maize varieties that are suited to mechanical grain harvesting and for studying the mechanisms of grain breakage resistance. Keywords: maize, mechanical grain harvest, breakage resistance, integral method, varieties classification DOI: 10.25165/j.ijabe.20201305.6037 Citation: Wang Y Z, Li L L, Gao S, Guo Y N, Zhang G Q, Ming B, et al. Evaluation of grain breakage sensitivity of maize varieties mechanically-harvested by combine harvester. Int J Agric & Biol Eng, 2020; 13(5): 8–16.

Hybrid Blood Collection Tubes: Combining the Best Attributes of Glass and Plastic for Safety and Shelf life.

SiO2 Medical Products, Inc. developed hybrid blood collection tubes (BCTs) that combine the breakage resistance of plastic and a shelf life approaching that of glass. These blended attributes provide improved BCT safety and reliability for patients and clinical workers. A shelf life of at least 2 y with less than 10% draw volume variation was demonstrated on evacuated hybrid BCTs, which is approximately 7 times longer than standard polyethylene terephthalate (PET) BCTs. This translates into more consistent and reliable blood draw volumes over a longer shelf life. The moisture vapor barrier of hybrid BCTs is 5 times lower than that of PET BCTs, which significantly reduces preservative evaporation over their shelf life. As a result, the risk of preservative gelation and alteration to the blood-to-preservative ratio mix is practically eliminated. Cyclic olefin polymer (COP) exhibits superior impact resistance to breakage because of its high ductility and impact strength and is not influenced by defects and flaws as is glass. Although COP has a mechanical toughness comparable with that of PET, it maintains this over a wider range of temperatures (–70 to 121 °C). As a result, COP can tolerate steam sterilization and cold storage temperatures without mechanical fatigue, deformation, or breakage. Lastly, extreme centrifugation of water-filled BCTs did not impose breakage of any kind.

Preparation and optimization of a low cost, high breakage resistance ceramic proppant special for the coal‐bed methane

AbstractA kind of low cost, high breakage resistance ceramic proppant special for exploitation of the coal‐bed methane is successfully produced. The producing conditions are optimized through orthogonal experimental design method. The breakage resistance results of the orthogonal analyses show the best condition of this kind of ceramic proppant is A4B3C3D2, which means sintering temperature of 1350 °C, manganese mineral powder content of 5 wt.%, weight ratio of 75/25 (second grade bauxite to mujie clay), and holding time of 3 h. The ceramic proppants under this very condition of A4B3C3D2 are then prepared and their phase structure and microstructure are characterized subsequently. X‐ray diffraction pattern exhibits that mullite and corundum are the main crystallographic phases. Scanning electron microscopy illustrates the A4B3C3D2 sample is with non‐porous morphology and small amount of corundum grains and liquid phase, which play the role of improving strength. It reveals the orthogonal experimental design is a feasible optimization method and the ceramic proppant made under the condition of A4B3C3D2 is a promising material for exploiting the coal‐bed methane resources.

Grinding Behaviors of Components in Heterogeneous Breakage of Coals of Different Ash Contents in a Ball-and-Race Mill

Coals used for power plants normally have different ash contents, and the breakage of coals by the ball-and-race mill or roller mill is an energy-intensive process. Grinding phenomena in mill of power plants is complex, and it is also not the same with ideal grinding tests in labs. The interaction among various coals would result in changes of grinding behaviors and energy consumption characterization if compared with those of single breakage. In this study, anthracite and bituminous coal of different ash contents were selected to be heterogeneously ground. Quantitation of components in products was realized using the relation between sulfur content of the mixture and mass yield of one component in the mixture. Product fineness t10 of the component was determined, and split energy was calculated on the premise of specific energy balance and energy-size reduction model by a genetic algorithm. Experimental results indicate that breakage rate and product fineness t10 of the mixture decrease with the increase of hard anthracite content in the mixture. Unlike the single breakage, t10 of anthracite in heterogeneous grinding is improved dramatically, and bituminous coal shows the opposite trend. The interaction between components results in the decrease of the specific energy of the mixture if compared with the mass average one of components in single breakage. Breakage resistance of hard anthracite decreases due to the addition of soft bituminous coal, and grinding energy efficiency of anthracite is also improved compared with that of single grinding.

Evaluation of grain breakage sensitivity of maize varieties mechanically-harvested by combine harvester

A high grain breakage rate is the main problem that occurs during mechanical maize harvest in China. The breakage sensitivity of different varieties was significantly different, and the breakage resistance is heritable. Therefore, breakage resistant variety screening can help improve the field production efficiency and provide references for breeding work. In this study, 42 varieties of maize were harvested with the same mechanical parameters and the same manipulator on a range of harvest dates at experimental stations in Xinxiang, Henan Province, in 2017 and Changji, Xinjiang Province, in 2018 to determine the sensitivity of grain moisture content on grain breakage rate during machine harvest for different varieties. The integral value of the grain breakage rate curve corresponding to the range of 15% to 30% grain moisture content was used as an index that expressed the sensitivity of maize grains to breakage depending on grain moisture content (BSW). Forty-two varieties were categorized as having weak, intermediate, or strong BSW. Among the same four varieties in the two stations, Lianchuang 825 and Lianchuang 808 were classified as sensitive and fragile varieties, Shandan 650 was classified as an intermediate variety, Zeyu 8911 was divided into weak sensitive and breakage-resistance varieties in Xinxiang and intermediate varieties in Changji. The BSW classification results at the two experimental sites were generally consistent, indicating that breakage sensitivity due to moisture content may be a relatively stable genetic characteristic. This study suggested that the integral method for determining BSW can be used to assess the resistance of different maize varieties to grain breakage during mechanical harvesting. The integral method was used to identify twelve breakage-resistant varieties in Xinxiang Station, and six breakage-resistant varieties in Changji Station. This study provides a method for screening maize varieties that are suited to mechanical grain harvesting and for studying the mechanisms of grain breakage resistance. Keywords: maize, mechanical grain harvest, breakage resistance, integral method, varieties classification DOI: 10.25165/j.ijabe.20201305.6037 Citation: Wang Y Z, Li L L, Gao S, Guo Y N, Zhang G Q, Ming B, et al. Evaluation of grain breakage sensitivity of maize varieties mechanically-harvested by combine harvester. Int J Agric & Biol Eng, 2020; 13(5): 8–16.

The crystallization and rheological behaviors of the ultrahigh molecular weight polyethylene swollen by petrolatum

In this paper, petrolatum was utilized as a swelling agent to improve the processability of ultrahigh molecular weight polyethylene (UHMWPE), and the microstructure, crystallization behaviors and rheological behaviors of these swollen UHMWPE were investigated. Petrolatum exhibits strong swelling ability and remarkably improves the chain mobility and processability of UHMWPE. With the increase of petrolatum concentration, more and more petrolatum molecules penetrate into the entangled chain networks of UHMWPE, and the enhanced chain disentanglements accelerate the crystallization of UHMWPE, strengthen the deformation breakage resistance of UHMWPE and make the chain segments of UHMWPE relax more quickly.

Design and optimization of NiMg/ceria-zirconia catalyst pellets

Mechanical strength plays a significant role in the industrial applications of the solid catalysts. Often powder catalysts must be “formed” into pellets to meet pressure drop restrictions in packed tubular reactors. The pellets must be designed to be mechanically stable when subjected to thermal and mechanical stresses during operation. The objective of this study was to evaluate the effect of powder processing parameters on mechanical stability of the resulting extruded cylindrical NiMg/Ce0.6Zr0.4O2 pellet catalysts. The binder amount, water amount, and pH of solvent impacted physicochemical properties and mechanical strength of the catalysts. Optimal amounts of binder and water, as well as a low slurry pH can increase the crush strength and breakage resistance. An enhancement in mechanical strength of 220% was obtained by optimizing the binder to solvent ratio and pH conditions. The tri-reforming performance (e.g., CH4 and CO2 conversions, and H2/CO molar ratio) was minimally impacted when the powder processing was optimized to improve mechanical strength.