Search Results (212)

The growing complexity of production systems in the technology sector demands advanced tools to ensure efficiency, flexibility, and cost-effectiveness. This study presents the development of a simulation model for a selective soldering line at a technology manufacturing company in Poland, created during an engineering internship. Using FlexSim 24.2 software, the real production process was replicated, including input/output queues, manual insertion (MI) stations, soldering machines, and quality control points. Special emphasis was placed on implementing dynamic process logic via ProcessFlow, enabling detailed modeling of token flow and system behavior. Through experimentation, various configurations were tested to optimize process time and the number of soldering pallets in circulation. The results revealed that reducing pallets from 12 to 8 maintains process continuity while offering cost savings without impacting performance. An intuitive operator panel was also developed, allowing users to adjust parameters and monitor outcomes in real time. The project demonstrates that simulation not only supports operational decision-making and resource planning but also enhances interdisciplinary communication by visually conveying complex workflows. Ultimately, the study confirms that simulation modeling is a powerful and adaptable approach to production optimization, contributing to long-term strategic improvements and innovation in technologically advanced manufacturing environments. Full article

Biodegradable polymer composites offer promising alternatives to petroleum-based plastics, supporting the principles of a zero waste and circular economy. This study investigates the reinforcing potential of alkali-treated wood flour derived from recycled pine (Pinus brutia Ten.) and poplar (Populus alba L.) waste wooden pallets in poly(lactic acid) (PLA) biocomposites. Wood flour was initially recovered through grinding and screening during recycling, followed by alkali treatment via a green chemistry approach to enhance interfacial bonding with the PLA matrix. The impact of alkali concentration and two fabrication methods—additive manufacturing (AM) and injection molding (IM)—on the properties of developed biocomposite materials was assessed through mechanical, physical, morphological, and thermal analyses. IM samples outperformed AM counterparts, with the IM PLA containing 30 wt% wood flour (alkali-treated with 10% solution) showing the highest mechanical gains: tensile (+71.35%), flexural (+64.74%), and hardness (+2.62%) compared to untreated samples. Moreover, the AM sample with 10 wt% wood flour and 10% alkali treatment showed a 49.37% decrease in water absorption compared to the untreated sample, indicating improved hydrophobicity. Scanning electron microscopy confirmed that alkali treatment reduced void content and enhanced morphological uniformity, while thermal properties remained consistent across fabrication methods. This work introduces a green composite using non-toxic materials and treatments, facilitating eco-friendly production aligned with zero waste and circular economy principles throughout the manufacturing lifecycle. Full article

Background: The growth of parcel volumes in urban areas, largely driven by e-commerce, has increased the complexity of pickup and delivery operations. To meet demands for cost efficiency, flexibility, and sustainability, CEP (Courier, Express, and Parcel) operators increasingly outsource segments of their last-mile networks. Methods: This study proposes a novel multidimensional cost model for outsourcing, integrating five key variables: transport unit type (parcel/pallet), service phase (pickup/delivery), vehicle category, powertrain type, and delivery point type. The model applies correction coefficients based on internal operational costs, further adjusted for location and service quality using a bonus/malus mechanism. Results: Each cost component is calculated independently, enabling full transparency and route-level cost tracking. A real-world case study was conducted using operational data from a CEP operator in Bosnia and Herzegovina. The model demonstrated improved accuracy and fairness in cost allocation, with measurable savings of up to 7% compared to existing fixed-price models. Conclusions: The proposed model supports data-driven outsourcing decisions, allows tailored cost structuring based on operational realities, and aligns with sustainable last-mile delivery strategies. It offers a scalable and adaptable tool for CEP operators seeking to enhance cost control and service efficiency in complex urban environments. Full article

Natural-fiber-reinforced polypropylene (PP) composites are gaining increasing interest as lightweight, sustainable alternatives for various packaging and applications. This study investigates the effect of filler addition sequence on the mechanical, morphological, thermal, and dynamic mechanical properties of PP-based composites reinforced with graphite nanoplatelets (GnP) and kenaf fiber (KF). Two filler incorporation sequences were evaluated: GnP/KF/PP (GnP initially mixed with KF before PP addition) and GnP/PP/KF (KF added after mixing GnP with PP). The GnP/KF/PP composite exhibited superior mechanical properties, with tensile strength and flexural strength increasing by up to 25% compared to the control, while GnP/PP/KF showed a 13% improvement. SEM analyses revealed that initial mixing of GnP with KF significantly improved filler dispersion and interfacial bonding, enhancing stress transfer within the composite. XRD and DSC analyses showed reduced crystallinity and lower crystallization temperatures in the addition of KF due to restricted polymer chain mobility. Thermal stability assessed by TGA indicated minimal differences between the composites regardless of filler sequence. DMA results demonstrated a significantly higher storage modulus and enhanced elastic response in the addition of KF, alongside a slight decrease in glass transition temperature (T_g). The results emphasize the importance of optimizing filler addition sequences to enhance mechanical performance, confirming the potential of these composites in sustainable packaging and structural automotive applications. Full article

The forestry industry, both primary (sawn wood production) and secondary (output of reels, pallets, boxes, cooperage, and tool handles), is growing in importance in Honduras. In 2023, exports from this industry were mainly destined for Central America (58.19%), followed by North America (22.92%) and the Caribbean region (17.20%), with hardly any Honduran wood reaching Asia or Europe. Objective: The goal of this paper is to analyze the current situation of the Honduran timber industry, which is defined by its environmental deterioration caused by the overexploitation of timber resources. Methodology: Using secondary data from official national and international sources regarding the forestry industry in Honduras, we conducted a Welch’s ANOVA analysis added to two post hoc tests (Tukey and Bonferroni), complemented by a linear regression analysis using JASP software, version 0.19.3.0. to carry on our analysis. Findings: The results of our analysis underscore the urgent need to implement a series of public policies in both the medium and short term to strengthen the forestry industry in Honduras. One of Honduras’ greatest strengths is its civil society, particularly its indigenous communities, which are actively working to protect their land from deforestation and soil degradation. If public policies are not implemented in collaboration with private firms to foster the Honduran forest industry cluster, it could lead to significant socioeconomic and environmental consequences. These may include increased pressure on natural forests, rising unemployment, and the loss of an essential income source for forest owners, ultimately exacerbating poverty. Full article

This paper aims to fill a gap in relation to herbaceous biomass, which is the second most important source of biomass used for the production of solid biofuels in the form of pellets. Our research focuses on the final stage of compacted fuel production, specifically on the pressure densification of biomass into pellets. This review was conducted using bibliometric techniques. This analysis included searching indexed publications in the Web of Science—Core Collection and Scopus databases. The time range of the searched data was 1991–2024. First, bibliometric data were collected and quantitative analyses were performed. The next stage consisted of analyzing keywords from the authors’ publications using the VOSviewer program. The generated term maps allowed for the analysis of the frequency of keywords in different years and the most frequently cited ones, which enabled the identification of current research topics and the evolution of trends. Based on the collected data, applications, process parameters and raw materials used in the biomass densification process were determined. Following the bibliometric analysis, detailed analyses were carried out on the factors influencing the pressure compaction process. Full article

This study proposes a bi-objective optimization model for the inventory routing problem with pickup and delivery (IRP–PD) in a closed-loop supply chain, addressing the growing demand for sustainable logistics solutions. The model simultaneously minimizes transportation costs and inventory costs and enhances driver well-being by incorporating regular rest breaks. The network operates within a circular economy framework, where pallets are both delivered and returned for reuse, contributing to waste reduction. A normalized weighted-sum method is initially used to balance the conflicting objectives. However, since the model cannot efficiently solve large-scale instances, we adopt the NSGA-II metaheuristic to generate a Pareto front, enabling decision-makers to explore trade-offs between objectives. The model is tested on a single instance, and the results demonstrate a promising compromise between economic and social goals. Full article

To enhance the efficiency and extent of space resource development and utilization, this paper proposes a device designed for large-scale storage and transport of multi-species CubeSats, characterized by its high storage density and efficient transport capabilities. This paper comprehensively describes the structural composition and operational principles of this storage and transport system. Using dynamic simulation analysis, this paper studies the deployment mechanism of CubeSats within the push device and identifies the movement rules of the CubeSats during the deployment process. Simulation results show that under microgravity conditions, the average linear displacement speed of CubeSats reaches 32.8 mm/s during the pushing process. A prototype of the storage device was developed and tested for scenarios where the CubeSat’s initial position is aligned or misaligned relative to the transport pallet. The test results demonstrate that when the CubeSat’s initial attitude is misaligned, its pose can be autonomously adjusted to an ideal state upon entering the capture slide, with a maximum deviation of less than one degree. The designed push device and transport pallet exhibit robust anti-interference and tolerance capabilities. The transport process after pushing was tested, and the CubeSat pushed into the transport pallet was able to be stably transported to the designated location. In this process, the movement of the transport pallet was not interfered with by the storage device. The pushing device can complete the pushing task well. Full article

The efficiency of emergency response operations is critically dependent on the strategic storage and allocation of emergency supplies. Proper management of these resources reduces economic impacts and ensures prompt availability in crises. This study addresses the challenges and existing practices in emergency reserve warehousing, with a specific focus on a Fangshan District case study. It introduces optimized storage strategies and principles for storage location assignment, taking into account both planar and three-dimensional storage configurations. The study employs two pallet types to establish basic assumptions and formulates two models: one for standard pallets in three-dimensional storage and another for special pallets in planar storage, including scenarios for their combined usage. Utilizing an advanced non-dominated genetic algorithm (NSGA-II) with an elite strategy, the study conducts simulations and analyses of these models under various scenarios. The findings indicate that the application of the second scenario significantly improves storage location optimization in emergency reserve warehouses. Full article

Background: Due to the highly competitive nature of the retail sector, companies need to improve their operational efficiency. This study focuses on the application of the concepts of Lean production in the process of replenishing products on the shelves of the shops of one of the largest food retail chains in Portugal. Methods: This study aims to apply a transition from a “push” to a “pull” approach, based on real-time consumption. During a 5-day test, the impacts of implementing Lean principles and ergonomic trolleys in the process were investigated. Results: The test led to improved efficiency in product replenishment by eliminating pallets and reducing unfavourable product handling from the initial process. The implementation of a replenishment system in this manner allowed a reduced labour requirements from 28.4 to 19.2 man-hours per day and, the elimination of unnecessary handling and increase of product availability were reflected in gains on operational time and in replenishment time. Conclusions: This study provides empirical evidence for the effectiveness of Lean pull systems in retail replenishment, demonstrating a 32% reduction in labour hours. Full article

This paper presents an experimental and numerical investigation of the axial compression behavior of perforated cold-formed steel upright profiles commonly used in pallet racking systems. The primary objective is to examine how slenderness influences the failure modes and load-bearing capacity of these structural elements. Three column lengths, representative of typical vertical spacing in industrial rack systems, were tested under pin-ended boundary conditions. All specimens were fabricated from 2 mm thick S355 steel sheets, incorporating web perforations and a central longitudinal stiffener. Experimental results highlighted three distinct failure mechanisms dependent on slenderness: local buckling for short columns (SS-340), combined distortional–flexural buckling for medium-length columns (MS-990), and global flexural buckling for slender columns (TS-1990). Finite Element Method (FEM) models developed using ANSYS Workbench 2021 R1 software accurately replicated the observed deformation patterns, stress concentrations, and load–displacement curves, with numerical results differing by less than 5% from experimental peak loads. Analytical evaluations performed using the Effective Width Method (EWM) and Direct Strength Method (DSM), following EN 1993-1-3 and AISI S100 specifications, indicated that EWM tends to underestimate the ultimate strength by up to 15%, whereas DSM provided results within 2–7% of experimental values, especially when the entire net cross-sectional area was considered fully effective. The originality of the study is the comprehensive evaluation of full-scale, perforated, stiffened cold-formed steel uprights, supported by robust experimental validation and detailed comparative analyses between FEM, EWM, and DSM methodologies. Findings demonstrate that DSM can be reliably applied to perforated sections with moderate slenderness and adequate web stiffening, without requiring further local reduction in the net cross-sectional area. Full article

Recent industrial production paradigms have seen the promotion of the outsourcing of low-value-added operations to robotic cells as a service, particularly end-of-line packaging. As a result, various types of research have emerged, offering different approaches to the trajectory design optimization of robotic manipulators and their applications. Over time, numerous improvements and updates have been made to the proposed methodologies, addressing the limitations and restrictions of earlier work. This survey-type article compiles research articles published in recent years that focus on the main algorithms proposed for addressing placement and minimum-time path planning for a manipulator responsible for performing pick-and-place tasks. Specifically, the research examines the construction of an automated robotic cell for the palletizing of regular heterogeneous boxes on a collision-free mixed pallet. By reviewing and synthesizing the most recent research, this article sheds light on the state-of-the-art manipulator planning algorithms for pick-and-place tasks in palletizing applications. Full article

Pallet-type end-effectors robots are widely used for airport baggage handling, because of their better adaptability to different types of baggage. A novel attitude-variable high acceleration motion planning method is presented for improving the handling efficiency, which is to move a pallet with non-fixed baggage as fast as possible under a given path, such that the baggage does not slip at any time. Firstly, the motion state model, which focuses on the friction force between the pallet and baggage during handling, is established. The influence of handling attitude on maximum handling acceleration is analyzed, which is verified by a real robot system made up of an IRB-6700 robot and a pallet. Then, a high acceleration motion planning method is proposed by changing the pallet attitude to avoid relative sliding. Finally, three numerical simulations are implemented to verify the proposed motion planning method. The results show that this method can at least improve handling efficiency by 17.64% in linear motion and up to 34.55% in curved motion compared with the horizontal fixed-attitude handling. Full article

Automated storage and retrieval systems (AS/RS) play a crucial role in modern logistics, yet effectively monitoring cargo stacking patterns remains challenging. While computer vision and deep learning offer promising solutions, existing methods struggle to balance detection accuracy, computational efficiency, and environmental adaptability. This paper proposes a novel machine vision-based detection algorithm that integrates a pallet surface object detection network (STEGNet) with a box edge detection algorithm. STEGNet’s core innovation is the Efficient Gated Pyramid Feature Network (EG-FPN), which integrates a Gated Feature Fusion module and a Lightweight Attention Mechanism to optimize feature extraction and fusion. In addition, we introduce a geometric constraint method for box edge detection and employ a Perspective-n-Point (PnP)-based 2D-to-3D transformation approach for precise pose estimation. Experimental results show that STEGNet achieves 93.49% mAP on our proposed GY Warehouse Box View 4-Dimension (GY-WSBW-4D) dataset and 83.2% mAP on the WSGID-B dataset, surpassing existing benchmarks. The lightweight variant maintains competitive accuracy while reducing the model size by 34% and increasing the inference speed by 68%. In practical applications, the system achieves pose estimation with a Mean Absolute Error within 4 cm and a Rotation Angle Error below 2°, demonstrating robust performance in complex warehouse environments. This research provides a reliable solution for automated cargo stack monitoring in modern logistics systems. Full article

Volcanic fermentation is an innovative technique in post-harvest coffee processing that involves forming conical mounds, called “volcanoes”, to create specific biotransformation conditions. This study investigates the impact of different volcano fermentation methods on the chemical composition and sensory attributes of coffee. Four methods were evaluated: asphalt patio (E1), on pallets (E2), in steel containers under the sun (E3), and in steel containers in the shade (E4). The chemical composition was analyzed in terms of sugars (sucrose, glucose, fructose), organic acids (citric, malic, succinic, lactic, acetic) and alcohols (glycerol, ethanol). In addition, color differences (ΔE) and sensory analysis of the fermented coffees were evaluated. The results of this study reveal that volcanic fermentation produces high-quality specialty coffees, but with divergent profiles of acids and alcohols, thus influencing the sensory characteristics of the resulting beverage. However, the different methods of volcanic fermentation did not significantly affect pH and soluble solids, indicating that the microbiota developed an efficient and consistent fermentation regardless of the solar exposure conditions. The most frequently mentioned sensory descriptors were chocolate, citrus fruits, honey/molasses, caramel, floral, and brown sugar. These findings highlight the significant influence of the volcanic fermentation method on the chemical and sensory quality of coffee fermented. Full article