Optimization of Mechanical Structure for Pomegranate Peeling and Low\u2010Damage Seed Extraction Technology Based on Mechanical Property Analysis: A Comprehensive Review

Rapid prototyping (RP) has evolved as frontier technology in the recent times, which allows direct transformation of CAD files into functional prototypes where it tremendously reduces the lead time to produce physical prototypes necessary for design verification, fit, and functional analysis by generating the prototypes directly from the CAD data. Part quality in the rapid prototyping process is a function of build parameters such as hatch cure depth, layer thickness, orientation, and hatch spacing. Thus an attempt was made to identify, study, and optimize the process parameters governing the system which are related to part characteristics using Taguchi experimental design techniques quality. The part characteristics can be divided into physical part and mechanical part characteristics. The physical characteristics are surface finish, dimensional accuracy, distortion, layer thickness, hatch cure, and hatch file, whereas mechanical characteristics are flexural strength, ultimate tensile strength, and impact strength. Thus, this paper proposes to characterize the influence of the physical build parameters over the part quality. An L9 orthogonal array was designed with the minimum number of experimental runs with desired parameter settings and also by analysis tools such as ANOVA (analysis of variance). Establishment of experimentally verified correlations between the physical part characteristics and mechanical part characteristics to obtain an optimal process parameter level for betterment of part quality is obtained. The process model obtained by the empirical relation can be used to determine the strength of the prototype for the given set of parameters that shows the dependency of strength, which are essential for designers and RP machine users.

Establishment of Process Model for Rapid Prototyping Technique (Stereolithography) to Enhance the Part Quality by Taguchi Method

Background. The strength of metals greatly limits the possibility of obtaining products by plastic deformation. The electromagnetic nature of the processes of structure formation and plastic deformation provided the basis for the application of additional influence of the magnetic field. A fairly large volume of research material has been accumulated on the topic of additional influence of the magnetic field on ferro-, dia- and paramagnetic metals. The researches of recent years have an applied nature of studying the magnetoplasticity of technical alloys. Their generalization will make it possible to move from laboratory research to the development of equipment and technologies for combined pressure processing of metal products in a weak magnetic field. Objective. Generalization and analysis of the results of laboratory and theoretical studies of the additional application of the magnetic field in the processes of mechanical testing of metals and alloys.Methods. Literary review of materials of articles, monographs, dissertations. Results. Reasonable use of a magnetic field for plastic deformation of metals. The explanation of the mechanism of the influence of the magnetic field on the structural elements of metals based on the effect of magnetoplasticity has been made. The description of changes in the mechanical properties of metals and alloys under the additional influence of a magnetic field is given. Conclusions. The phenomenon of magnetoplasticity has been studied for a wide range of materials such as pure metals and their alloys, including industrial steels and alloys. Various types of positive effects of a magnetic field on the mechanical properties of metals have been established: a decrease in the yield strength and deformation resistance, an increase in strain, relaxation of internal stresses, and a decrease in dislocation density. There is also a reverse, negative effect of the influence of a magnetic field: increased rate of hardening, embrittlement, increased creep of metals. What will be the effect of a magnetic field on a specific metal cannot be guaranteed with high accuracy.

The study was conducted from August 2023 to September 2024 at the Department of Agricultural Engineering, College of Horticulture, Munirabad, Karnataka, India, with the objective of determining the engineering properties of apple ber (Ziziphus mauritiana). These properties are essential for the design and development of efficient material handling and food processing equipment. Fresh apple ber fruits were analyzed to evaluate their physical and mechanical characteristics, which serve as a crucial database for post-harvest operations such as grading, conveying, drying, and storage. The moisture content of the fruits ranged between 82–85% on a wet basis. The mean dimensions were recorded as 53 mm in length, 43 mm in width, and 22 mm in thickness, with a geometric mean diameter of 43.72 mm and sphericity of 0.67%. The average pulp-to-stone ratio was 8.00, indicating a high edible portion suitable for processing. The bulk density and true density were observed as 0.932 g/cm3 and 1.04 g/cm3, respectively, while the calculated porosity was about 12%. The angle of repose of the fruits ranged from 29° to 33°, reflecting their flow behavior during handling and storage. These engineering parameters provide valuable insights into the design of processing and handling equipment for apple ber, ensuring minimal mechanical damage and efficient material flow. The findings serve as a baseline for further research for optimizing equipment design, improved processing efficiency and equipment standardization in ber processing and post-harvest technology development.

In the research and development of technology and equipment for bamboo products deep processing, such as filling, drying, and medicinal use of bamboo flour (BF), the poor compaction and fluidity of BF materials entails the need for accurate discrete element model (DEM) and BF parameters to provide a reference for the simulation of BF processing operationsand the development of related equipment. The average particle size of the 5 types of BFs ranges from 0.136 mm to 0.293 mm, and the small particle size of BF particles causes to the number of BF particles in bamboo processing equipment to reach tens of millions or even billions. When conventional methods are used for simulation, ordinary computers cannot provide the required computing power. To address the aforementioned challenges, this paper proposes a calibration method for the discrete element contact parameters of BFs based on dimensional analysis and a back propagation (BP) neural network. Using particle scaling theory and dimensional analysis methods, the average particle size of the BF was increased to 1 mm, and the main discrete element contact parameters of the five types of BF to be tested were used as input layers. The injection method and sidewall collapse method were used to obtain the angle of repose (AR) as the output layer. Fifty groups were randomly selected using MATLAB for EDEM simulation, and the simulation results were trained using the BP neural network algorithm; an ideal neural network model was obtained, the discrete element parameters of different BFs were predicted, and physical experiments were performed to verify two types of AR and mold hole compression under calibrated parameters. The relative error between the simulated AR obtained through calibration parameters and the physical experimental values is less than 2.3%. Through BF parameter validity verification, the simulated maximum compression displacement and compression ratio after stabilization were 34.81 mm and 0.477, which were close to the actual experimental results of 34.77 mm and 0.461, respectively, verifying the accuracy of the neural network prediction model. The research results provide a reference for the simulation of BF processing operations and the development of related equipment.

Thus, at present, a large amount of rubber waste cannot be higher harnessed due to recovery technologies used. Also, the requirements for new products of rubber worldwide are greater than the production capacity and the availability of raw materials. To offset this balance is necessary to improve technologies for recycling waste rubber so to can get regenerated rubber with the best mechanical physical characteristics. The main technology for obtaining the regenerated rubber is based on the rubber waste shredding and making the powder, so that it can be carried out de-vulcanization in autoclave. All the time it was monitored as the de-vulcanization process to be as economical and less polluting, and this requires that the sizes of the crumb rubber to be optimal. Thus, in the conducted researches was aimed to establish the particle size of crumb rubber from waste rubber so as to obtain an economical de-vulcanization, but also a reclaimed rubber with superior physical and mechanical characteristics. The organization of researches was made so that crumb of rubber waste was divided into 5 groups, bowing from crumb rubber with particle’s size of 1000 μm (RPS1), and reaching up to crumb rubber with particle’s size of 200 μm (RPS 5).

With the continuous progress of sports science, the application of biomechanics in sports training has become an important tool to enhance sports performance and prevent sports injuries. Basketball, as a collective and confrontational sport, involves a large number of complex technical movements, such as shooting, dribbling, and jumping, which require precise mechanical regulation. The study of biomechanics can provide theoretical support for basketball teaching in colleges and universities, help optimize athletes’ technical movements, enhance training effects, and reduce sports injuries. Biomechanics is based on mechanical principles such as Newton’s laws of motion, kinematics, and dynamics, which can be effectively applied to basketball technical movements. For instance, in shooting, the motion can be divided into preparation, force application, release, and follow-through phases. Newton’s Second Law (F = ma) explains how the applied force influences the acceleration of the ball, while projectile motion principles determine the optimal angle and velocity for achieving maximum shooting accuracy. The Magnus effect also plays a role in guiding spin-based shooting techniques, affecting ball trajectory and stability. In dribbling, biomechanical analysis involves understanding how impulse (Impulse = Force × Time) affects ball control. By adjusting wrist force and contact time with the ball, players can improve dribbling efficiency and control under defensive pressure. Additionally, energy transfer and ground reaction forces are critical in jumping mechanics. Using the principles of conservation of momentum and the stretch-shortening cycle, athletes can maximize jump height and power through optimized force application and body positioning. This paper explores the application of biomechanics in college basketball teaching through experimental research. The experimental subjects are college basketball players, and biomechanical analysis of basketball technical movements (shooting, dribbling, jumping, etc.) is conducted using high-precision equipment such as motion capture systems and force platforms. The study collects physical data, mechanical characteristics, and sports performance data of the athletes during the execution of basketball technical movements, analyzing them in combination with biomechanical principles. This approach provides an in-depth understanding of movement efficiency and technique optimization. The results of the study show that training programs optimized through biomechanical analysis can significantly improve athletes’ technical performance. In shooting, dribbling speed, and jumping height, the experimental group demonstrated superior results compared to the control group, with statistically significant differences. Specifically, the shooting percentage of athletes in the experimental group increased by 6.3%, the dribbling speed improved by 9.6%, and the jumping height increased by 10.4%. These improvements confirm that the application of biomechanics in basketball teaching not only enhances performance but also reduces the risk of sports injuries by refining movement mechanics and optimizing force distribution. By integrating biomechanics into basketball training, educators and coaches can develop more scientifically grounded training methodologies, improving player efficiency while ensuring long-term physical well-being. This study highlights the necessity of incorporating mechanical principles in skill development, reinforcing the role of biomechanics in advancing sports education and training strategies.

Purpose. Research of characteristics of heat-resistant concrete for application in thermal units and building constructions. Methodology. By standard techniques physic, mechanical, fire and heat physical characteristics of heat-resistant concrete with additives of perlite sand are investigated. Findings. Compositions of heat-resistant concrete with additives of perlite sand in a number of 0,1-1,8% can be used for the production of thin-walled linings of metallurgical units and designs and also for the production of the building constructions steady against fire action. Originality. Influence of a small number of additives of perlite sand on physic mechanical, fire and heat physical characteristics of heat-resistant concrete is established. Practical value. The received heat-resistant concrete with additives of expanded perlite sand provide the high physic mechanical, fire and heat physical characteristics steady against the action of high temperatures and the fire. Keywords: heat-resistant concrete, expanded perlite sand, additive, samples, properties of concrete.

PurposeThe purpose of this study is to investigate the mechanical and tribological properties of the synthetic diamond coatings deposited on WC-Co cutting tools for their prospective applications in mechanical industry. In this work, the concept of nanocrystalline diamond, microcrystalline diamond and multilayer-diamond coating systems were proposed and deposited on WC-Co substrates with the top-layer nanocrystallinity, optimum thickness and interfacial adhesion strength for load-bearing tribological and machining applications. Also, the overall mechanical and tribological properties of all synthetic diamond coatings were compared for the purpose of selecting a suitable type of protective layer used on the surfaces of WC-Co cutting tools or mechanical dies.Design/methodology/approachSmooth and adhesive single layered and multilayered synthetic deposited on chemically etched cemented tungsten carbide (WC-Co) substrates using predetermined process parameters in hot filament chemical vapor deposition (HFCVD) method. A comparison has been documented between diamond coatings having different nature and architecture for the purpose of studying their mechanical and tribological characteristics. The friction characteristics were studied experimentally using ball-on-disc type linear reciprocating micro-tribometer under the influence of varying load conditions and within dry sliding conditions. Nanoindentation tests were conducted on each diamond coating using Berkovich nanoindenter for the measurement of their hardness and elastic modulus values. Also, the wear characteristics of all sliding bodies were studied under varying load conditions using cumulative weight loss and density method.FindingsDepositing any type of diamond coating on the cemented carbide tool insert increases its all mechanical and tribological characteristics. When using boron-doping onto the top-layer surface of diamond coatings decrease slightly their mechanical properties but increases the tribological characteristics. Present analysis reveals that friction coefficient of all diamond-coated WC-Co substrates decreases with the increase of normal load. Therefore, maintaining an appropriate level of normal load, sliding time, sliding distance, atmospheric conditions and type of diamond coating, the friction coefficient may be kept to some lower value to improve mechanical processes.Originality/valueAs the single layered synthetic diamond coatings have not given the full requirements of mechanical and tribological properties when deposited on cutting tools. Therefore, the multilayered diamond coatings were proposed and developed to enhance the interfacial integrity of the nanocrystalline and microcrystalline layers (by eliminating the sharp interface) as well as increasing the hardness of tungsten carbide substrate. However, when using boron doping onto the top-layer surface of diamond, coatings decreases slightly their mechanical characteristics but also decreases the value of friction coefficient.

Utilization of date pits waste as aggregate alternative in sand-epoxy-resin composite

A new attempt development of new hybrid composite materials has been studied. Increasing the mechanical and physical properties of composite materials to lower their weight and cost is the most frequent problem in engineering projects. This study's goal is to enhance the mechanical and physical characteristics of composite materials. Also due to this, hybrid composite materials have received recent attention. In this work, hybrid composite materials were created to enhance mechanical and physical characteristics. In this investigation, glass fiber and mica fiber were both employed as synthetic and natural fibers, respectively. The influence of mica as natural fiber with glass fiber as synthetic reinforcement by weight percent (wt%) on the mechanical properties of hybrid composite materials were investigated. Epoxy resin (thermosetting polymer) reinforced by various wt % of glass fiber/mica fiber, such as (0-0, 15-0, 10-5, 7.5-7.5, 5-10, 0-15 %), as well as samples created by hand lay-up method. In addition, glass fiber and mica fiber in long fiber unidirectional form are utilized; mechanical properties such as tensile, flexural and impact strength have been tested. As the results of this study, both glass fiber and mica fiber increased mechanical properties, although glass fiber has a greater effect than mica fiber but also using mica fiber make great improvement between 26% to 67%. Composites reinforced with 15% glass fiber had a better value of mechanical properties compared to others. Additionally, the hybrid composite made of glass fiber and mica fiber performed well in all tests, enhanced mechanical characteristics, which decreased the cost of making composites.

The usage of natural fiber reinforced composite is large in engineering applications due to the presence of high extensive properties and economy. This paper aims at presenting a new fiber, its characteristics, and composite in a polymeric matrix empowering the generation of less weight composites for load conveying applications. Spinifex Littoreus Fiber (SLF) is a genus of perennial coastal plants in the grass family. The comprehensive characterization that includes physical analysis, chemical analysis, thermal analysis, mechanical and microstructural characteristics have been carried out on the fiber. The effect of fiber weight percentage was studied from the point of view of the mechanical properties of the compression moulded Spinifex Littoreus Fiber Composites (SLFC). Mechanical properties attained at 40 wt% of fiber content were better. In addition to more fiber, it tends to cause inadequate bonding among the matrix and fiber, resulting in a decrease in mechanical performance. The specific properties of SLFC polymer composites are comparable to those of the glass fiber composite. This makes SLFC composite as an alternate lightweight material. SEM was performed for a study of the interfacial mechanism.

3 - Equipment Used for Radiation Processing of Polymers

Orthodontic elastic bands are commonly made from natural rubber because they provide high resiliency at a reasonable cost. However, hypersensitivity related to protein present in latex have been reported in some patients which has led to increased usage of non-latex elastic alternatives. Therefore, the assessment of their mechanical properties is of importance. The objective of this study was to compare the physical and mechanical properties of three commercial latex and non-latex type orthodontic elastic bands. Samples of latex and non-latex type orthodontic elastics from manufacturers – AO (6.5oz), MASEL (6.0oz), GAC (6.0oz), with 3/16-inch diameter were selected. Firstly, the physical characteristics (width, cross-sectional thickness, and inner diameter) of the elastic bands were determined, following which their mechanical properties [initial extension force (F0), 24 h-residual force (F24), percentage of force decay, force exerted at 3 times the inner diameter (F3xID) and breaking force] were tested. The data were analyzed with Mann-Whitney U test and multiple comparisons among the groups were done with Kruskal-Wallis Test (p< 0.05). Significant differences were found in the physical characteristics and mechanical properties among each brand and type of elastics. AO elastic bands had significantly low F0 and F24 compared with the others. While the percentage of force decay at 24 h was greatest in AO followed by MASEL and GAC. Non-latex type elastics showed greater force decay than latex type ones, approximately 30-40% and 20-30% of the initial force in non-latex and latex type elastic, respectively. AO elastics showed the highest F3xID and also the lowest breaking force. Overall, non-latex type elastics exhibited lower breaking force compared to latex type ones. Wide variations were observed in the physical and mechanical characteristics among same manufacturer and same elastic type. All commercial brands presented higher F3xID than that stated by the manufacturers. Non-latex type elastics showed greater force decay over 24 h than latex type ones. The differences in the properties between the 2 types of the elastics could be due to the differences in their structure and polymers composition.

Among a variety of technological defects of a cellular filler affecting its physical and mechanical characteristics, one of the most essential is believed to be the initial technological camber of facets in its cell. The paper reports a study into the effect of technological camber of a cellular filler's facets on its physical-mechanical characteristics, which ensures the stabilization of its quality and, consequently, the operational characteristics of structures based on it. In contrast to available studies, we have considered a discrete-element cell model. A cellular filler has been represented in the form of a structure consisting of various elements: facets of a single foil, facets of two glued layers of foil, and imaginary edges – the angular butt joint zones of two neighboring facets. The process of consistent loss of bearing ability by the cell elements of a cellular filler under transverse compression and longitudinal shear has been investigated. This analysis of the performance of separate elements of a cell in the presence of the initial technological camber has made it possible to take into consideration the operational patterns of each of them by building the appropriate load-type chart of filler deformation. On this basis, we have devised an approach that makes it possible to predict the character of cellular filler operation taking into consideration the patterns in accepting the loading by separate elements of the honeycomb cell in the presence of the initial technological camber in them. Recommendations have been given for using the obtained results within the approaches, proposed in a series of studies, for optimizing cellular structures for the mass of design parameters. The recommendations enable the synthesis of a module for the verification optimization unit, which produces a conclusion on the carrying capacity of an optimal, in terms of mass, variant of the sandwich-type structure with a cellular filler, taking into consideration the presence in its facets of initial technological camber within the range of regulated tolerance. Such synthesis at the modern level of production technology of a cellular filler would help implement almost exhaustive capabilities of this type of the filler, as well as the structures based on it.