Farm mechanization in Bangladesh is exponentially growing which has led to timeliness of farm operation and increased crop productivity and farm income. For shifting of farm labour to non-farm sectors, sustainable crop production, efficient management of farm inputs, doubling the productivity and enhancing 4AR (Four Agricultural Revolution) dictating the use of appropriate and quality farm machinery. Different types of local and imported farm machinery are used in crop production. There was no legal authority functioning for testing and certification of these farm machinery in Bangladesh since 1989 to 2024. So, the farmers are not always getting quality and standard farm machinery although they have to pay good price to purchase machines. The farm machinery manufacturers are also suffering from proper marketing of machines due to unavailable of legal testing and certification facilities. Testing and certification of farm machinery are crucially essential to assess their functional suitability and performance reliability so that it will help farmers and other users in determining the comparative performance of machines available in market. Earlier, there was a Farm Machinery Testing and Certification System in Bangladesh but it was abolished in 1989 for rapid expansion of farm mechanization. Some experts opined that testing and certification system may restrict the abandoned uses of different farm machinery which may slow down the rapid speed of farm mechanization. So, the policy makers are confused about introducing the testing and standardization of farm machinery in Bangladesh, although there is a provision for Farm Machinery Testing and Certification System in National Agricultural Mechanization Policy 2020 and National Agricultural Mechanization Action Plan 2023. Recently, (February, 2025) National Standardization Committee (NSC) and Technical Sub-committee (TSC) have been formed. This paper explores the past and current states of farm machinery testing and standardization in Bangladesh, discussing existing challenges and potential solutions.
An in-depth analysis was conducted on the dynamic strength design optimization of carbon fiber composite cap cones in aircraft engines subjected to bird body impacts. Initially, the top, 1/4, 1/2, 3/4, and root positions of the cap cone’s generatrix were designated as the impact sites. The analysis of bird impacts revealed that the 1/2 position along the generatrix is the most hazardous impact location. Subsequently, considering the thickness of the composite material cap cone as a variable and accounting for its high-speed rotational state, a bird impact analysis was performed at the most critical impact location. Additionally, a comparative study on the bird impact performance of the composite material cap cone under rotating and non-rotating conditions was conducted. The study indicates that, under identical conditions, the cap cone in rotation experiences more severe damage than in a non-rotating state, necessitating a cone thickness of 7 mm or greater; Subsequently, a bolt strength analysis model was established to thoroughly examine the impact of varying cone side thicknesses on the load applied to connecting bolts, and to assess bolt strength. The findings suggest that excessive bolt loads can also constrain the optimization of the cap cone; hence, finding the optimal balance between bolt quantity and strength is essential in design. Lastly, the study discussed the weakening of local stiffness in the composite material cap cone post-impact, noting a 12% decrease in its elastic mode frequency and the emergence of asymmetric vibration modes. This phenomenon could potentially lead to dynamic unbalanced loads, thus necessitating further evaluation in the optimization process of the cap cone.
The aim of this work is to develop and test an analytical model that is deemed to be more accurate than the traditional method in the prediction of the mechanical behavior of hollow box beams. The methodology was tested with a hollow box beam of a rectangular section. To achieve the aim, a new analytical model was derived. An FEM model of a simple box beam was built, and the results of the comparison between the classical theory, the novel equation, and the l numerical method are presented. It was possible to validate the new equation with the numerical model and the classical equation. It was observed that the novel equation can predict the mechanical behavior of the studied geometries with better accuracy than the classical equation.
The development of vehicle simulation models is becoming increasingly important, especially for the virtual validation of new automotive features. New methods are emerging that need to be tested and validated to ensure their proper functioning. The use of artificial intelligence methods can accelerate product development processes, so it is essential for companies to examine the applicability of these solutions. This article compares the results of a traditional rule-based transmission model and an artificial intelligence-based transmission model against real vehicle measurements. Creating a transmission model using the new artificial intelligence-based method requires less time and effort than developing a rule-based model. However, experimental data is required to train the model. This paper addresses the challenges of artificial intelligence-based transmission modeling and highlights the new advantages of artificial intelligence-based solutions.
V. Pandiaraj, M. Selvam, R. Ganapathy Srinivasan
et al.
The purpose of this study is to reduce the losses in impulse turbines by changing the dimensions of turbine blades by using four different materials with three different dimensions. The turbine blades were manufactured using a fusion deposition model of a Rapid prototyping machine. The materials used for this manufacturing process included nickel, molybdenum and materials like carbon and stainless steel reinforced with plastics.
K. Balasubramanian, S. John Alexis, Sivakumar Rajagopal
This work aimed to improve machining efficiency by adding texture to the rake face of a tungsten carbide cutting tool. To create this texture, the tool’s rake face was painstakingly carved with micro grooves. Assessing and contrasting how textured cutting tools affect machining performance was the main goal. The von-Mises stress distribution was analyzed by simulating the cutting tool with ANSYS 16.0. According to this simulation, the surfaced tool had greater von-Mises stress levels than the non-textured one. Using a lathe machine, experimental machining operations were performed on low carbon steel with both surfaced and standard cutting tools under the same rake angle of the tool, feed rate during machining, cutting speed during machining, and depth of cut during machining process parameters. The cutting operations were carried out with both wet and dry lubrication techniques. Comparing the surfaced carbide tool to the standard cutting tool, this experimental result showed a significant decrease in cutting forces, feed forces, and coefficients of friction. These results highlight the potential advantages of surfaced cutting tools for improving performance and efficiency during machining of low carbon steel substrates.
This paper explores the intricate relationship between man and nature in Ernest Hemingway’s The Old Man and the Sea through the lens of deep ecology. It challenges the traditional anthropocentric interpretation of the novella, proposing that the protagonist Santiago’s struggle is not merely a tale of human triumph over nature but a journey towards understanding and coexisting with the natural world. By applying the principles of deep ecology, the study reveals how Santiago’s evolving relationship with the marlin and other sea elements reflects a broader ecological consciousness. The analysis also draws parallels between Santiago’s experience and the Biblical narrative of Jonah, suggesting that Santiago’s success is not solely due to his physical endurance but also the cosmic forces that aid him. This paper ultimately rethinks the themes of struggle and victory in the novella, emphasising the need for a harmonious relationship between humanity and the environment.
Garlic is a versatile vegetable commonly grown in subtropical and highland agroecosystems, which is utilized for its culinary, medicinal, and spice properties. The use of garlic as a medicinal aid can be traced back to ancient times. The health benefits of garlic production are attributed to its antiviral, antibacterial, and antifungal properties. The use of garlic is prevalent in both traditional and modern healthcare systems, where it is used to treat a wide range of conditions. Numerous studies have reported the therapeutic properties of garlic, and its effectiveness has been demonstrated in clinical trials. The growing global interest in health and wellness, the widespread use of garlic as a spice, and its potential economic, social, and health benefits have contributed to a surge in its demand worldwide. This review aims to provide a comprehensive overview of the scientific literature on the morphological descriptions of garlic and its nutritional and health significance.
Wilhelm Söderkvist Vermelin, Madhav Mishra, Mattias P. Eng
et al.
Remaining useful life prediction models are a central aspect of developing modern and capable prognostics and health management systems. Recently, such models are increasingly data-driven and based on various machine learning techniques, in particular deep neural networks. Such models are notoriously “data hungry”, i.e., to get adequate performance of such models, a substantial amount of diverse training data is needed. However, in several domains in which one would like to deploy data-driven remaining useful life models, there is a lack of data or data are distributed among several actors. Often these actors, for various reasons, cannot share data among themselves. In this paper a method for collaborative training of remaining useful life models based on federated learning is presented. In this setting, actors do not need to share locally held secret data, only model updates. Model updates are aggregated by a central server, and subsequently sent back to each of the clients, until convergence. There are numerous strategies for aggregating clients’ model updates and in this paper two strategies will be explored: 1) federated averaging and 2) federated learning with personalization layers. Federated averaging is the common baseline federated learning strategy where the clients’ models are averaged by the central server to update the global model. Federated averaging has been shown to have a limited ability to deal with non-identically and independently distributed data. To mitigate this problem, federated learning with personalization layers, a strategy similar to federated averaging but where each client is allowed to append custom layers to their local model, is explored. The two federated learning strategies will be evaluated on two datasets: 1) run-to-failure trajectories from power cycling of silicon-carbide metal-oxide semiconductor field-effect transistors, and 2) C-MAPSS, a well-known simulated dataset of turbofan jet engines. Two neural network model architectures commonly used in remaining useful life prediction, long short-term memory with multi-layer perceptron feature extractors, and convolutional gated recurrent unit, will be used for the evaluation. It is shown that similar or better performance is achieved when using federated learning compared to when the model is only trained on local data.
Engineering machinery, tools, and implements, Systems engineering
Climate change is affecting water resources and other aspects of life in many countries, generating more frequent extreme events. Users react to intermittent supply by implementing local private tanks to collect as much water resources as possible to cope with water distribution suspension periods. Such tanks are commonly overdesigned due to the common perception that water resources are essential for human activities and the general need of users to safeguard their water supplies. This study evaluated the impact of water scarcity and users’ self-adaptation strategies on water demand under intermittent flow conditions by implementing an experimental campaign in a real network. The analysis was conducted using a short-term water demand forecast model that reproduces periodic patterns observed at an annual, weekly and daily level to evaluate the adaptation response of users concerning the scarcity of water resources through a comparison between the real pattern of the network and the pattern of local tanks.
Koji YAMAMOTO, Masato SOMEMIYA, Norio HIRAYAMA
et al.
A series of numerical material tests based on homogenization theory are carried out to characterize the anisotropic elastoplastic and hardening behavior of thermoplastic resin reinforced in one direction by carbon fibers (UD-CFRTP), and a new constitutive model is proposed to describe the characteristic material behavior. First, macroscopic stress-strain curves are obtained from numerical material tests (NMTs) conducted on a unit cell model, i.e., a representative volume element of periodic microstructures, to which uniaxial and combined stress states are applied under various conditions of stress ratios and stress paths. Using the obtained NMTs results, the initial shape of the yield surface and its evolution are investigated in detail. The results suggest that even if a resin has isotopic hardening characteristics, UD-CFRTP exhibits complex anisotropic post-yielding or, equivalently, hardening behavior. Then, a constitutive model that can describe such material behavior is originally formulated, and a step-wise identification strategy is presented to determine the material parameters. Finally, by carrying out verification analyses, we confirmed that the macroscopic stress-strain curves represented by the proposed model can be fitted to those obtained by NMTs with sufficient accuracy for practical use and that the performance of the proposed model is much better than that of a conventional constitutive law.
Mechanical engineering and machinery, Engineering machinery, tools, and implements
Plastic waste has increased worldwide due to the steady rise in plastic consumption. Several strategies were developed to mitigate plastic waste. Among these methods, pyrolysis is a promising technology for converting plastic waste into valuable products. This paper discusses the latest advancements in the pyrolysis of three common types of plastic waste: polyvinyl chloride (PVC), polypropylene (PP), and polystyrene (PS). The challenges associated with the pyrolysis of these plastics are highlighted, and an outlook on the future of research on pyrolysis is given. Overall, this review provides valuable insights into the current state of research on the pyrolysis of PVC, PP, and PS. This has implications for advancing pyrolysis technology to contribute to a more sustainable and circular economy.
A meshing cycle of normal contact ratio gear can be divided into three stages, i.e., double pairs of teeth meshing, single pair of teeth meshing and double pairs of teeth meshing. In many previous literatures, for the convenience of research, the dynamic model based on a pair of teeth was usually used to express the dynamic behavior of all pairs of teeth in the entire meshing cycle, which will cause the problem that the established dynamic model cannot fully reflect the influence of the meshing state of each pair of teeth on the dynamic characteristics of the system. Therefore, based on the relevant literature, a nonlinear dynamic model of spur gear pair considering the meshing state of multiple pairs of teeth is proposed in this paper. The new model can fully reflect meshing error, meshing stiffness, backlash of multiple pairs of teeth participating in the meshing at the same time. To compare the differences between the new model and the traditional model, the main factor causing the difference between them is analyzed. Based on the calculation of single pair of teeth and comprehensive meshing error by TCA (tooth contact analysis) method, the effects of different meshing error, contact ratio and meshing damping on the system dynamic characteristics respectively based on the two models are compared and discussed. The results show that the new model can reflect the dynamic behavior of each pair of teeth participating in the meshing at the same time more accurately than the traditional model, especially when contact ratio and meshing damping are large. The new model proposed in this paper lays a foundation for building a more accurate dynamic model of a gear pair (especially the HCR gear pair with the contact ratio greater than 2) and accurately analyzing the dynamic behavior of each pair of teeth in meshing.
Engineering machinery, tools, and implements, Mechanical engineering and machinery
This work integrates nanotechnology, adsorption, and magnetic separation to remove chromium (Cr) pollutant from industrial wastewater using magnetic nanoparticles. The magnetic nanocomposite consists of chitosan biopolymer and iron (Fe3O4) magnetic nanoparticles. The Fe3O4 magnetic nanoparticles were prepared by chemical co-precipitation technique and the chitosan magnetic nanocomposite (CMNC) was prepared by Ex situ process. Moreover, anoval amination of CMNC with hexamine to get functionalized CMNC was performed to remove Cr (VI) in wider range of pH. The prepared Fe3O4 magnetic nanoparticles, CMNC and functionalized CMNC were characterized using different analytical techniques, XRD, FTIR, AFM, SEM, EDX and TGA.
Batch adsorption was employed to determine the effects of pH. The adsorption results show that the functionalized CMNC possessed high activity for Cr (VI) removal in any condition of acidic, neutral and basic solutions with the percentage sorption of chromium reached to 91.7%.
Sorption isotherms were fitted with the Langmuir, Freundlich and Temkin models, it was found that the Freundlich isotherm model have the best fit with R2=0.998 with functionalized CMNC. The kinetic data of Cr (VI) sorption with functionalized CMNC were fitted well with the pseudo-second order kinetic model. The reuse of the functionalized CMNC indicates that the adsorbent material is more than 80% adsorption capacity after five regeneration cycles. The results of this work shown that functionalized CMNC is a potential adsorbent to removal of Cr (VI) contaminated in a wider range of pH.
Engineering machinery, tools, and implements, Mechanics of engineering. Applied mechanics
A modified sintering model was presented to analyze the deformation behaviors of brazing powder compact throughout the whole sintering process, both the thermal-mechanical plastic deformation and metallic alloying were implemented as sintering driving forces in the numerical simulation by the sintering model. Ag-Cu-Sn brazing powder compacts were prepared by electromagnetic compaction technique and sintered at different temperature, the simulated deformations were in reasonable agreement with the experimental deformations. Deformation analysis with different relative density was conducted by the sintering model to reveal the volume expansion mechanism and volume shrinkage mechanism throughout the whole sintering process, it was indicated that the sintering warpage or cracks are prominently related to relative density gradients, and the higher relative density of brazing powder compacts is beneficial to sintering densification. At last, the deformation behaviors of brazing powder compacts with three typical shapes were numerically predicted to provide guidelines for tool design and sintering process optimization.
Engineering machinery, tools, and implements, Mechanical engineering and machinery
This study presents novel analysis and synthesis methods for a certain type of geared adjustable stroke mechanism. The mechanism has significance in mechanical design, as it has been used in practice. However, to the best of our knowledge, any theory on its analysis or synthesis is not available in the literature. The problem is divided into four parts and each part is generalized. Novel synthesis procedures for possible largest stroke are developed. Design charts are prepared for maximum stroke configuration. Stroke variation is an important concern in mechanism design. By adopting the introduced method, the output stroke can simply be adjusted even during the operation. The output stroke of the mechanism can be decreased more than 50% with proper transmission, velocity and acceleration characteristics. Use of non-integer gear ratio is also investigated. That property leads a variable stroke mechanism inherently. The relationship between the gear ratio and the number of cycles needed to return to the initial stroke value is determined. As a result, all possible design methods are investigated and generalized for this mechanism. Therefore, significant flexibility is introduced for adapting this mechanism to various practical applications.
Engineering machinery, tools, and implements, Mechanical engineering and machinery
Paper describes the procedure for developing academic programs which are properly aligned to the requirements of the knowledge-based economy. The paper also addresses the continuous quality improvement (CQI) process with the CQI loop closing on the program level and the course level. This process is needed to make continuous adjustments to an academic program, so that the program is always aligned to the constantly-changing needs of the economy. Paper also discusses the system of mutual dependency between the academic program and external partnership like local industry, secondary schools, local government, local community, regional business incubator center, other educational institutions, alumni and industrial advisory council. The ongoing collaboration with external partners allows the program to prosper and grow.
Machine design and drawing, Engineering machinery, tools, and implements
Austenitic stainless steels are materials, that are widely used in various fields of industry, architecture
and biomedicine. Their specific composition of alloying elements has got influence on their
deformation behavior. The main goal of this study was evaluation of magnetic properties of selected
steels, caused by plastic deformation. The samples were heat treated in different intervals of temperature
before measuring. Then the magnetic properties were measured on device designed for measuring
of magnetism. From tested specimens, only AISI 304 confirmed effect of plastic deformation on
the magnetic properties. Magnetic properties changed with increasing temperature.
Machine design and drawing, Engineering machinery, tools, and implements
Saburo MATSUOKA, Shigeru HAMADA, Hisatake ITOGA
et al.
The case study on cooling pipe of pre-cooler, which had been used on a verification test of 70 MPa hydrogen station, was carried out. Cooling pipe consisted of main pipe, mechanical joint pipe and mechanical joint. Main pipe and mechanical joint pipe were joined by TIG welding. Chemical composition analysis, microstructure observation and Vickers hardness measurement showed that the main pipe and the mechanical joint pipe were manufactured from SUS316L, and that the filler metal of TIG welding was 316L. Round specimens were machined out from main pipe to investigate tensile properties of the base metal. On the other hand, round specimens and square specimens having reinforcement were machined out form the weld joint. Using three types of specimens, slow strain rate tests were conducted in 0.1 MPa nitrogen gas and 115 MPa hydrogen gas at −40 °C. Reductions of area for the base metal round specimen, the weld joint round specimen and the weld joint square specimen were 83.5, 71.3 and 81.4 % in nitrogen gas, whereas the values were 60.1, 61.3 and 40.1 % in hydrogen gas. That is, reductions of area for three types of specimens were smaller in hydrogen gas than in nitrogen gas. Dimples were formed on fracture surfaces of three types of specimens in nitrogen gas, whereas dimples and quasi-cleavages were formed in hydrogen gas. These results suggest that cooling pipe of pre-cooler can be “embrittled” in high-pressure hydrogen gas at low temperature.
Mechanical engineering and machinery, Engineering machinery, tools, and implements