Bangladesh has undergone one of the most significant agricultural transformations in South Asia, driven by the rapid evolution of farm machinery since the mid- 20th century. From a purely manual and animal-driven farming system to a modernized agricultural landscape characterized by power tillers, tractors, combine harvesters, mechanical irrigation, and emerging digital tools. Farm mechanization has reshaped production practices, rural labour dynamics, and food security. This historical review synthesizes existing research, national policies, sectoral reports, and development project documents to examine the chronological evolution of farm machinery in Bangladesh. The study identifies four key phases: pre-mechanization (before 1960), early mechanization (1960-1990), rapid mechanization (1990-2010), and advanced mechanization with modern and digital integration (2010-present). It explores the technological drivers, socio-economic influences, and institutional roles behind this transformation. The review highlights significant gains in productivity, expansion of irrigated area, labour savings, and growth of rural machinery service market. Despite these achievements, challenges remain in land fragmentation, import dependency, sustainability of diesel-based machinery, and shortage of skilled operators. The paper concludes by suggesting directions for future research and policy, focusing on sustainable, energy-efficient, and small-farm-friendly mechanization to support climate resilient agricultural development in Bangladesh.
Alexander M. Mikhalchenkov, Sergey A. Feskov, Andrey V. Kubyshkin
BACKGROUND: Theoretical and practical studies in the field of abrasive wearing of soil tilling tools are generally focused on the processes of galling of working surfaces of their components. Meanwhile, the factor of changing the shape of an abrasive particle during its motion on the wearing plane remains behind the study focus. Not considering the abovementioned factor leads to wrong conclusions and have a negative impact on development of the technology of manufacturing, strengthening and restoration of structural components of agricultural machinery. AIM: Conducting theoretical studies of the wearing process of the abrasive fraction of soil during its motion on the working surface of the components of soil tilling tools. METHODS: The study was conducted with using the known theoretical studies in the field of abrasive wearing. The integral calculus and fundamentals of tribological engineering were used. RESULTS: The study result is derivation of the formula, which shows the degree of changing the shape of an abrasive particle taking its motion on the friction surface and soil pressure into account. The parameter that mainly defines the wearing rate is the value of the external force. The theoretical study was considered for cultivator shovels. It is shown that the obtained mathematical expressions can be used practically for all components of the soil tilling tools. CONCLUSION: The obtained mathematical equations point out the potential presence of three factors in the wearing process, such as scratching, contact deformation and rolling in dependence of changing the shape of the abrasive substance during its motion on the friction surface.
Toru TSUMUGIWA, Aoi SAKATA, Masanori MURAKAMI
et al.
Impedance control has been extensively used in robot control in physical human–robot interactions between humans and robots. To achieve smooth operation, various evaluations of operator responses have been performed during robot operation under impedance control. Although conventional studies have extensively employed assessments of motion characteristics based on manipulation force and hand tip positions and subjective evaluations, limited research has been conducted on physiological indicator evaluations to objectively assess human sensibility. During robot operation, humans plan control strategies for bodily movements by perceiving impedance parameters in the brain. Consequently, brain activity measurements have been extensively used to investigate the impact of impedance parameters on operators. In addition, recent research has elucidated control strategies based on human hand tip motion based on motor characteristics and muscle activity. However, conventional research has seen limited efforts in elucidating control strategies based on human hand tip motion, and simultaneous measurement and evaluation of motor characteristics and brain/muscle activity are seldom performed. Therefore, in this experiment, the forces, hand tip positions, muscle activity, and brain activity of the operators were measured during physical interactions, and statistical evaluations were performed on the operator’s physiological responses and motor characteristics arising from differences in impedance parameters. The experiment results indicate that impedance parameters influence motor characteristics and brain/muscle activity. Furthermore, the brain and muscle activity measurements indicate a correlation between brain activation and muscle force output, suggesting that insights into control strategies based on human manipulative forces and hand tip motion can be partially elucidated through temporal data analysis of hand velocity.
Mechanical engineering and machinery, Engineering machinery, tools, and implements
This paper discusses an approximate multiscale stochastic stress analysis of a randomly arranged unidirectional fiber reinforced composite plate under the transverse tensile loading. The multiscale stochastic stress analysis is desired for quantitative apparent strength evaluation of composites with random microstructure, and an efficient method has been attractive in terms of computational efficiency. In particular, since huge numbers of fibers are included in an actual composite structure, accurate and efficient estimation of microscopic maximum stresses for random fiber location variation and their probabilistic properties is required. For this analysis, the successive local approximation method is employed. The effectiveness of the approximate multiscale stochastic stress analysis has been discussed, while the square array is assumed in previous literature. For applicability confirmation of the method to evaluation of an actual problem, the usage of a hexagonal array model should be discussed. From these backgrounds, the above analysis with the hexagonal array model is performed, and validity and effectiveness of this approach are discussed with the numerical results.
Mechanical engineering and machinery, Engineering machinery, tools, and implements
Mohammad Toufiqul Hoque, Tian Benrui, Thomas Grethe
et al.
Cellulosic materials like cotton and linen are excellent textile substrates for dyeing with reactive and direct dyes. Due to their cellulosic nature, cotton and linen exhibit good affinity towards direct and reactive dyes. This good affinity is the reason for good washing and rubbing fastness. Chitosan is a bio-based polymer gained by the deacetylation of chitin. In contrast to cellulose, chitosan exhibits also amino functional groups. The purpose of this paper is to evaluate if a chitosan based pretreatment of cotton and linen can lead to different dyeing properties. After different chitosan based pretreatments, the color properties are determined by CIEL*a*b* indices. The rubbing fastness in dry and wet conditions is measured. Even if in the actual study no positive effects were determined by pretreatment of chitosan, the determined results could be utilized in future research to develop other functional treatments of cotton and linen materials with implemented chitosan.
Textile bleaching, dyeing, printing, etc., Engineering machinery, tools, and implements
Mani Mohan Tiwari, Saleema Noormohammed, Dilip Kumar Sarkar
et al.
Considering the challenges faced when joining multi-materials where welding is not possible, such as with polymers and metal, adhesives can be used to bond them. In this study, two chemically different adhesives, namely epoxy and silicone, were used to bond PVC/Al. Infrared spectra of a mixed adhesive revealed the presence of overlapping peaks with PVC, namely –CH<sub>2</sub>, –CH<sub>3</sub> around 2800–3000 cm<sup>−1</sup> and Si–CH<sub>3</sub> at 1260 cm<sup>−1</sup>. Mechanical testing on single-lap shear specimens of PVC/Al prepared using mixed adhesive showed the enhancement in the adhesive strength was ~5 times higher compared to the adhesive strength of PVC/Al joints made with only silicone adhesive.
Choudhary Safal, Randhawa Princy, Kumar J. P. Sampath
et al.
Juvenile Idiopathic Arthritis (JIA) is a widespread and chronic condition that affects children and adolescents worldwide. The person suffering from JIA is characterized by chronic joint inflammation leading to pain, swelling, stiffness, and limited body movements. Individuals suffering from JIA require ongoing treatment for their lifetime. Beyond inflammation, JIA patients have expressed concerns about various factors and the lack of responsive services addressing their challenges. The implementation of smart garments offers a promising solution to assist individuals with Juvenile Idiopathic Arthritis in performing their daily activities. These garments are designed to seamlessly integrate technology and clothing, providing not only physical support but also addressing the psychological and emotional aspects of living with a chronic condition. By incorporating sensors, these smart garments can monitor joint movement, detect inflammation, and provide real-time feedback to both patients and healthcare providers. To tackle these comprehensive challenges, the research aims to offer a solution through the design of a smart garment, created with a holistic approach. This smart garment is intended to improve the overall well-being of JIA patients by enhancing their mobility, comfort, and overall quality of life. The integration of technology into clothing can potentially revolutionize the way JIA is managed, allowing patients to better manage their condition and minimize its impact on their daily lives. The synergy between healthcare and technology holds great potential in addressing the multifaceted challenges posed by Juvenile Idiopathic Arthritis patients. Through innovation and empathy, this research aims to pave the way for a brighter future for individuals living with Juvenile Idiopathic Arthritis.
Flexure hinges are widely used for very high precision mechanisms, such as a high precision linear guide, a nano positioning stage, a robot hand and etc., because of no gap and no friction. Regarding circular hinge stiffnesses, Paros and Weisbord derived exact solutions, but they are unwieldly because of the complexity. Simpler equations are preferred to use in analyses of the assembled mechanisms composed of flexure hinges. Therefore, in this paper, approximate stiffness equations for the semicircular hinge are discussed. The approximate equations were also derived by Paros and Weisbord, but their tensile stiffness equation does not give a good result. And, many studies were performed for the circular hinge, but their stiffness equations are apart from the exact solutions when the hinge thickness is large. In this paper, new approximate stiffness equations are derived by substituting approximate functions of series for the small terms of the exact solutions. Errors between the delivered approximate solutions and the exact solutions are less than 3 percentages in the wide range of the hinge thickness. The derived approximate stiffness equations give better results than other approximate equations in the wide range of the hinge thickness. And, they are useful for the actual design because it is easily recognized how design parameters contribute to the stiffnesses.
Mechanical engineering and machinery, Engineering machinery, tools, and implements
In recent years, upgrading manufacturing informatization has put forward higher requirements for the designer. The traditional design method requires designers to switch their thinking on the platform of multiple dimensions, which increases the difficulty. With the development of virtual reality technology, the design process in a 3D environment can be realized. Aiming at the conceptual design stage in the design process, this paper carries out multi-modal interactive design for different tasks in the full three-dimensional environment. A multi-modal modeling method based on gesture interaction and supplemented by voice interaction and eye movement interaction is established through relevant experiments and analysis. The relevant platform is developed based on the Unity 3D engine, and the modeling process is completed. This paper proposes a solution to the modeling process in a 3D environment and the Enlightenment of further research.
Hasan Tahir, Benny Malengier, Carla Hertleer
et al.
A textile-based triboelectric nanogenerator (TENG) is an energy harvesting flexible and lightweight device that converts mechanical energy to electrical energy. This work presents characterization of a novel hybrid 3D printed embroidery TENG for energy harvesting. The digital embroidery part is done on Brother Embroidery Machine PR670E with polyester multifilament conductive hybrid thread (CleverTex) with a linear thread resistance of 280 Ω/m. This embroidery thread is fully compatible with the standard textile embroidery process. The thread is highly suitable for embroidery due to its very good mechanical properties and no loop formation during embroidery. These features make the thread especially suitable for high production quality. It could be used as needle thread or bobbin thread. For the preparation of the embroidery part, the polyester multifilament conductive hybrid thread is used as needle thread with 100% polyester Madeira thread as bobbin thread. These threads have non-toxic, non-skin irritation properties, which makes them suitable for smart wearable energy harvesting applications. Furthermore, these threads are coated with silicone-paraffin emulsions that improve their running during the embroidery process. Among the possible stitch types (satin, fill, prog. fill, piping, motif, cross, concentric circle, radial, spiral, flexible spiral, stippling, net fill, zigzag net fill, and decorative fill), fill stitch with medium stitch density and 4.5 lines per mm has been used to develop this energy harvesting sample. The 3D printed textile fabric is prepared with extremely flexible filament with a tensile elongation at break of 1400%. The output voltage is 200 V and 103 V for tapping and friction characterization, respectively
Textile bleaching, dyeing, printing, etc., Engineering machinery, tools, and implements
Uwe Füssel, Stephan Schlegel, Gregor Reschke
et al.
As a joining-by-forming process, clinching and the use of functional elements enable low-energy joining of components through form, force, and, under certain conditions, material closure. In addition to the transmission of mechanical forces, these joining processes can be qualified for additional electrical contact within the scope of functional integration for electro-mobile applications. For this purpose, maximizing the force and material closure is necessary to ensure a long-term, stable transmission of electrical currents. To this end, the electrical properties of the joints were optimized. The investigations carried out show the long-term behavior under normal operating conditions and the short-circuit case.
This paper presents the merging support system considering the constraint of the merging zone. Merging in a highway is one of the most difficult driving tasks. In lane changing and merging, drivers consider about safety and longitudinal ride comfort. In addition, drivers must finish merging in the merging zone. To achieve these objectives, we propose the merging support system. It consists of the merging decision maker, the merging planner, the longitudinal controller and the lateral controller. The merging decision maker compares the selectable merging positions and selects one with smallest acceleration. The merging planner generates the velocity plan and the lateral path plan to reach to the selected merging position. The longitudinal and lateral controllers follow these plans by the feedback controller and the feedforward controller. The performance of the proposed system is tested by simulations. In these simulations, the merging decision maker and the merging planner calculates the velocity plan and the lateral path plan to finish merging in the merging zone with the smallest acceleration, and the longitudinal and lateral controllers follows these plans accurately. These results show that the proposed merging support system contributes safe and comfortable merging. In addition, we demonstrate that the length of the merging zone affects the merging decision.
Mechanical engineering and machinery, Engineering machinery, tools, and implements
The simplified elastic-plastic correction factor Ke is quoted in fatigue damage assessments for component design to predict elastic-plastic strain from elastic strain without performing elastic-plastic analyses. The Ke factor has been widely used in various design codes, although its value has been determined according to individual policy to achieve conservative assessments. Recently, the American Society of Mechanical Engineers (ASME) modified the Ke factor for thermal loading. By assuming elastic-plastic strain could not become large for thermal loading, a reduced Ke value was applied when the stress was caused by thermal expansion loading. This paper discusses the applicability of Ke for thermal loading to the design code by the Japan Society of Mechanical Engineers (JSME). First, the Ke factor for thermal loading and its background are reviewed, and then, Ke values from several codes are compared. Second, finite element analyses (FEA) for a straight pipe subjected to a fluid temperature transient are conducted to obtain values for comparison of the Ke factor prescribed in the ASME and JSME codes. The Ke values obtained by FEA become larger than those of the revised Ke of the ASME. It is shown that Ke value depends on the boundary condition. The Ke factor of ASME is valid only when the axial displacement is fully constrained or frequency of the fluid temperature fluctuation is fast enough. Third, based on detailed investigations, conservative Ke value for thermal loading is proposed. Finally, the characteristics of the change in the elastic-plastic strain for thermal loading are summarized and discussion is made about how the Ke factor is prescribed in the JSME design code.
Mechanical engineering and machinery, Engineering machinery, tools, and implements
The field of energy, specifically renewable energy sources (RES), is considered vital for a sustainable society, a fact that is clearly defined by the European Green Deal. It will convert the old, conventional economy into a new, sustainable economy that is environmentally sound, economically viable, and socially responsible. Therefore, there is a need for quick actions by everyone who wants to move toward energy-efficient development and new environmentally friendly behavior. This can be achieved by setting specific guidelines of how to proceed, where to start, and what knowledge is needed to implement such plans and initiatives. This paper seeks to contribute to this very important issue by appraising the ability of full-scale implementation of RES combined with energy storage in an island power system. The Greek island power system of Astypalaia is used as a case study where a battery energy storage system (BESS), along with wind turbines (WTs), is examined to be installed as part of a hybrid power plant (HPP). The simulation’s results showed that the utilization of HPP can significantly increase RES penetration in parallel with remarkable fuel cost savings. Finally, the fast response of BESS can enhance the stability of the system in the case of disturbances.
Engineering machinery, tools, and implements, Technological innovations. Automation
To develop a tactile display, we focused on the Velvet Hand Illusion (VHI), which is a tactile illusion phenomenon. The most important feature of VHI is that VHI is not generated in one wire but is generated in two or more wires. This means that we recognize the area surrounded by wires as a Gestalt and a smooth surface sensation is generated in the Gestalt. We assume that the VHI mechanism is related to the law of closure and the law of common fate in Gestalt theory. In this paper, we investigate the relationship between VHI and the law of closure by means of variation in a phase difference of two wires’ cyclic movement, and formulate VHI variation, taking into account the law of closure. We try to divide the law of closure into two factors: one of them is a factor of translation and the other is a factor of elasticity. We formulate the tactile Gestalt and verify the validity of this formulation by comparing the result of the psychophysical experiment to the estimation via the formulation. This work shows that the law of closure in the tactile Gestalt consists of the translation factor and the elasticity factor, and the VHI mechanism is described by the formulation of the tactile Gestalt.
Engineering machinery, tools, and implements, Mechanical engineering and machinery
In Japan, most of the gear units for transmitting driving force in railway vehicles employ one-stage speed reducers. The gear unit is composed of a pinion connected to a traction motor via a coupling mechanism, a gear installed on an axle, and a gear case that covers them. In their rotating parts, tapered roller bearings are mainly used, and are lubricated by gear oil splashed by the rotating gear. In order to prevent seizure of the bearings and to improve the reliability of the gear units, it is important to appropriately adjust the bearing clearance. The bearing clearance can change from its initial value during the travel of the vehicles due to an atmospheric temperature and its initial value when assembling the gear unit, and can affect the performance of bearings. In this research, an actual gear unit was subjected to bench rotation tests under various bearing clearances and various atmospheric temperatures. The bearing temperature and torque were measured, and changes in bearing clearance were estimated. As a result, it is found that the bearing clearance decreases immediately after the rotation starts, and this tendency becomes more remarkable as the initial bearing clearance is smaller and as the atmospheric temperature is lower.
Engineering machinery, tools, and implements, Mechanical engineering and machinery
Hiroki NAKAMURA, Toru YAMAZAKI, Kazunori KASAHARA
et al.
Selected from various Eigen modes of blading, nodal diameter κ= 0 and κ= 1 are both related to shaft torsional and/or axial vibration and shaft bending vibrations respectively. In order to avoid the possibility of 2f (f=power system frequency) from torsional vibration resonance, ISO specifies the final calculation results considering the combination between κ= 0 blade and torsional shaft vibration. Previous study has reported a global method for blade-shaft torsional coupled vibration analysis governing both κ= 0 and κ= 1 in a systematic manner, and torsional coupled vibration analysis was completed. However, it is also known that coupling of blade-shaft axial vibration also influences the resonance of blade-shaft system, and it is highly requested to estimate resonance frequency accurately. Thus, a method for blade-shaft coupled vibration analysis in consideration of axial vibration coupling is proposed and its feasibility is investigated. A scale model of steam turbine is targeted as an example and calculated resonance frequencies are compared with experimental data and FEM data. As a result, the new method in consideration of axial vibration coupling is feasible tool to calculate resonance frequencies more precisely than previous method.
Mechanical engineering and machinery, Engineering machinery, tools, and implements