Plastic industry workers are often exposed to repetitive tasks and awkward postures due to mass production, increasing their risk of ergonomic-related injuries. This study aimed to assess these risks in a real plastic syringe injection molding factory, focusing on the injection molding workstation as a case study. Various ergonomic assessment tools were used, including the Cornell Musculoskeletal Disorder Questionnaire, Ovako Working Posture Analysis System (OWAS), Rapid Upper Limb Assessment (RULA), and Rapid Entire Body Assessment (REBA), and Jack Siemens software for posture simulation. The results revealed that workers are commonly experienced pain in the lower back, neck, and shoulders. After implementing ergonomic modifications to the workstation, the assessment tools indicated a significant reduction in risk levels: compression forces on the lower back decreased by 30%, shear forces by 49%, and the percentage of time spent in risky joint angles per work cycle decreased by 3% for the neck, 23% for the back, 3% for the shoulder, 5% for the wrist, and 9% for the elbow. These findings highlight the importance of ergonomic redesign in improving worker health and reducing occupational hazards.
This study presents a numerical comparison between Direct numerical simulation (DNS) and the standard κ-ε turbulence model to evaluate natural convection in a two-dimensional, differentially heated, air-filled cavity over the Rayleigh number range 10<sup>3</sup> to 10<sup>10</sup>. The objective is to assess the predictive capabilities of both methods across laminar and turbulent regimes, with a particular emphasis on the quantitative comparison of thermal characteristics under high Rayleigh number conditions. The Navier–Stokes and energy equations were solved using the finite element method with Boussinesq approximation, employing refined meshes near the hot and cold walls to resolve thermal and velocity boundary layers. The results indicate that for Ra ≤ 10<sup>6</sup>, the κ-ε model significantly underestimates temperature gradients, maximum velocities, and average Nusselt numbers, with errors up to 19.39%, due to isotropic assumptions and empirical formulation. DNS, in contrast, achieves global energy balance errors of less than 0.0018% across the entire range. As Ra increases, the κ-ε model predictions converge to DNS, with Nusselt number deviations dropping below 1.2% at Ra = 10<sup>10</sup>. Streamlines, temperature profiles, and velocity distributions confirm that DNS captures flow dynamics more accurately, particularly near the wall vortices. These findings validate DNS as a reference solution for high-Ra natural convection and establish benchmark data for assessing turbulence models in confined geometries
Semantic segmentation of ultra-high-resolution remote sensing (UHR-RS) imagery plays a critical role in land use and land cover analysis, yet it remains computationally intensive due to the enormous input size and high spatial complexity. Existing studies have commonly employed strategies such as patch-wise processing, multi-scale model architectures, lightweight networks, and representation sparsification to reduce resource demands, but they have often struggled to maintain long-range contextual awareness and scalability for inputs of arbitrary size. To address this, we propose RingFormer-Seg, a scalable Vision Transformer framework that enables long-range context learning through multi-device parallelism in UHR-RS image segmentation. RingFormer-Seg decomposes the input into spatial subregions and processes them through a distributed three-stage pipeline. First, the Saliency-Aware Token Filter (STF) selects informative tokens to reduce redundancy. Next, the Efficient Local Context Module (ELCM) enhances intra-region features via memory-efficient attention. Finally, the Cross-Device Context Router (CDCR) exchanges token-level information across devices to capture global dependencies. Fine-grained detail is preserved through the residual integration of unselected tokens, and a hierarchical decoder generates high-resolution segmentation outputs. We conducted extensive experiments on three benchmarks covering UHR-RS images from 2048 × 2048 to 8192 × 8192 pixels. Results show that our framework achieves top segmentation accuracy while significantly improving computational efficiency across the DeepGlobe, Wuhan, and Guangdong datasets. RingFormer-Seg offers a versatile solution for UHR-RS image segmentation and demonstrates potential for practical deployment in nationwide land cover mapping, supporting informed decision-making in land resource management, environmental policy planning, and sustainable development.
Mhd Ayham Darwich, Katreen Ebrahem, Maysaa Shash
et al.
This study aims to develop an integrated approach for 3D lumbar vertebral biomodel design and analysis, specifically targeting unilevel disc degeneration and the replacement of lumbar artificial discs. Key objectives include improving existing design methods through 3D techniques, inverse modeling, and an engineering biomodel preparation protocol. Additionally, the study evaluates mechanical properties in the implantation area and between disc components to gauge the effectiveness of artificial discs in restoring functional movement within the studied biological model. The construction of a biological model representing the L3–L4 functional spinal unit was based on measurements from radiographic images and computed tomography data obtained from the study sample. The 3D finite element method in Ansys software (v. 19.2, ANSYS, Inc., Canonsburg, PA, USA) was used to monitor the distribution of equivalent stress values within the core of the two artificial discs and the behavior of vertebral bone components in the model. This approach enabled the creation of personalized digital models tailored to the specific implantation requirements of each patient. Stress analysis identified critical areas within the disc cores, suggesting potential design modifications to optimize artificial disc performance, such as selectively increasing core thickness in specific regions and considering adjustments during implantation. For example, preserving part of the lateral annulus fibrosus from the degenerative disc and maintaining the anterior and posterior longitudinal ligaments may play a crucial role in balancing the forces and moments experienced by the lumbar section. This study provides valuable insights into the development of patient-specific solutions for lumbar disc degeneration cases, with the potential for enhancing artificial disc design and implantation techniques for improved functional outcomes.
To meet the requirements of deployable structures in aerospace engineering with light weight and high stiffness, this paper proposes the triangular space membrane deployable mechanism based on deployable booms, then conducts dynamic analysis and multiobjective optimization. The configuration design and mass calculation for the membrane mechanism are carried out, including its unfolding support mechanism and tensioned membrane scheme. With a view to performing the dynamic characteristics analysis and parametric studies, the finite element simulation model of the membrane mechanism, including boom, cable and membrane, is built and validated against test results obtained by Polytec. On the basis of the simulation results, a surrogate model of fundamental frequency is established by adopting the response surface method and applied to multiobjective optimization combined with the mass formula. Then, the optimal dynamic and lightweight design parameters are solved via the genetic algorithm. The results provide an indication to aid with the design and analysis of space membrane deployable mechanisms according to the required properties and space mission requirements.
Most existing chaotic systems have many drawbacks in engineering applications, such as the discontinuous range of chaotic parameters, weak chaotic properties, uneven chaotic sequence outputs, and dynamic degradation. Therefore, based on the above, this paper proposes a new method for the design of a three-dimensional chaotic map. One can obtain the desired number of positive Lyapunov exponents, and can also obtain the desired value of positive Lyapunov exponents. Simulation results show that the proposed system has complex chaotic behavior and high complexity. Finally, the method is implemented into an image encryption transmission scheme and experimental results show that the proposed image encryption scheme can resist brute force attacks, correlation attacks, and differential attacks, so it has a higher security.
β -titanium alloys are essential in many applications, particularly biomedical applications. Ti-14Mn β -type alloy was produced using an electric arc furnace from raw alloying elements in an inert atmosphere. The alloy was homogenized at 1000 °C for 8 h to ensure the complete composition distribution, followed by solution treatment at 900 °C, then quenched in ice water. The alloy was subjected to cold deformation via cold rolling with different ratios: 10, 30, and 90%. The phases change, microstructure, mechanical properties, and corrosion resistance of Ti-14Mn alloys were evaluated before and after cold rolling. The results showed that the β -phase is the only existed phase even after a high degree of deformation. The microstructure shows a combination of twinning and slipping deformation mechanisms in the deformed alloy. Microhardness values indicated a linear increase equal to 30% by increasing the ratio of cold deformation due to the strain hardening effect. The corrosion resistance of Ti-14Mn alloy was doubled after 90% cold rolling.
Materials of engineering and construction. Mechanics of materials, Chemical technology
The paper reveals the results of the survey, carried out by non-linguistic students of National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”. Special attention is devoted to comparative analysis of feedback of respondents studying English online at the Institute of Physics and Technology (IPT) and Instrumentation Engineering Faculty (IEF) under the COVID-19. The actuality of the study is determined by the necessity of learning about students` experience studying English online during the 2020-2021 academic year for educators to design effective online courses and strategies, adjust teaching practices according to students’ needs. To achieve the aim, the following tasks were completed: first of all, to establish technical aspects of students’ learning experience, their attitudes to grouping, interactive activities, tests, English lessons online in general, and then to use descriptive statistics for processing the obtained data. The results of the survey are analyzed, described, and presented. Overall, the respondents positively assessed their experience of studying English online under the COVID-19.
Post-occupancy evaluation (POE) is a systematic method to evaluate the actual building performance against the theoretical design intents after the building has been occupied for some time, to understand how the building is performing and to capture lessons learned. The POE offers an opportunity to investigate the buildings' actual performance based upon the occupants' satisfaction levels in the aspects of building overall design, indoor environmental quality, thermal comfort, etc. However, as the key part of POE, occupant satisfaction assessment (OSA) is a missing link in the building performance evaluation (BPE) domain, and there is not a systematic evaluation method for the OSA. Moreover, it is time-consuming and error-prone to conduct the OSA manually. This paper presents from the end-user's satisfaction perspective a semantic post-occupancy evaluation ontology (POEontology) to facilitate the occupant satisfaction assessment of buildings, with the ultimate aim of optimizing building operation guidelines, and improving occupants' use experience quality and well-being. An ontology-based knowledge model has been developed to capture the fragmented knowledge of building use satisfaction assessment in the POE domain, with the benchmarking evaluation rules encoded in Semantic Web Rule Language (SWRL) to enable automatic rule-based rating and reasoning. This ontology model also enables the effective OSA-related knowledge retrieving and sharing, and promotes its implementation in the POE domain. A field study has been conducted based upon the Building Use Study (BUS) methodology to validate the proposed ontology framework.
Cellular immunotherapies represent a promising approach for the treatment of cancer. Engineered adoptive cell therapies redirect and augment a leukocyte’s inherent ability to mount an immune response by introducing novel anti-tumor capabilities and targeting moieties. A prominent example of this approach is the use of T cells engineered to express chimeric antigen receptors (CARs), which have demonstrated significant efficacy against some hematologic malignancies. Despite increasingly sophisticated strategies to harness immune cell function, efficacy against solid tumors has remained elusive for adoptive cell therapies. Amongst cell types used in immunotherapies, however, macrophages have recently emerged as prominent candidates for the treatment of solid tumors. In this review, we discuss the use of monocytes and macrophages as adoptive cell therapies. Macrophages are innate immune cells that are intrinsically equipped with broad therapeutic effector functions, including active trafficking to tumor sites, direct tumor phagocytosis, activation of the tumor microenvironment and professional antigen presentation. We focus on engineering strategies for manipulating macrophages, with a specific focus on CAR macrophages (CAR-M). We highlight CAR design for macrophages, the production of CAR-M for adoptive cell transfer, and clinical considerations for their use in treating solid malignancies. We then outline recent progress and results in applying CAR-M as immunotherapies. The recent development of engineered macrophage-based therapies holds promise as a key weapon in the immune cell therapy armamentarium.
This study assessed how science, technology, engineering and mathematics (STEM) education is integrated in Science Teacher Education curriculum in Zimbabwe. An exploratory mixed methods research design, within the post-positivist paradigm, was used to guide the collection and analysis of data. Data were sourced from 18 Science teacher educators and 108 final year Science student teachers pooled from two secondary school Teachers’ Colleges through a semi-structured questionnaire, follow-up interviews, focus groups and documents. From the findings, it was evident that although a lot was done to promote STEM literacy in the two colleges, integration of STEM education and practices into the science education curriculum was coincidental rather than planned. Participation in Science exhibitions at local and national level that was common and increased enrolment of teacher candidates in STEM subjects was viewed as major ways to promote the initiative in the Teachers’ Colleges. However, support that targeted a teacher education STEM curriculum and integration/liaison with Engineering and industry was largely found lacking, suggesting the need for practices such as field-trips, work visits and partnerships that foster closer collaboration between colleges, schools, professional scientists and industry.
Sarah Shaikh Abdul Karim, Fariza Anis Md Tahir, Umul Khair Mohamad
et al.
Abstract Background During the COVID-19 pandemic, many countries instituted closure of borders from international and local travels. Stranded citizens appeal to their governments to embark on citizen repatriation missions. Between February and April 2020, the Government of Malaysia directed repatriation of its citizens from China, Iran, Italy and Indonesia. We describe the preparation and execution of the repatriation mission using chartered commercial aircraft. The mission objectives were to repatriate as many citizens based on aircraft capacity and prevent onboard transmission of the disease to flight personnel. Results Five repatriation missions performed was led by the National Agency for Disaster Management (NADMA) with the Ministry of Health providing technical expertise. A total of 432 citizens were repatriated from the missions. The operations were divided into four phases: the pre-boarding screening phase, the boarding and in-flight phase, the reception phase and the quarantine phase. The commercial aircraft used were from two different commercial airlines. Each mission had flight crew members between 10 and 17 people. There were 82 positive cases detected among the repatriated citizens. There was a single positive case of a healthcare worker involved in the mission, based on the sample taken on arrival of the flight. There were no infections involving flight team members. Conclusion Medical flight crew must be familiar with aircraft fittings that differ from one commercial airline to another as it influences infection control practices. A clear understanding of socio-political situation of a country, transmission routes of a pathogen, disease presentation, and knowledge of aviation procedures, aircraft engineering and design is of great importance in preparing for such missions. Our approach of multidiscipline team involvement managed to allow us to provide and execute the operations successfully.
Medical emergencies. Critical care. Intensive care. First aid
Nonlinear bending and nonlinear free vibration analysis are presented for FG nanobeams based on physical neutral surface concept and high-order shear deformation beam theory with a von Kármán-type equations and including thermal effects. The material properties are temperature-dependent and vary in the thickness direction. Nonlinear bending approximate solutions and free vibration solutions for present model with fixed supported boundary conditions are given out by a two-step perturbation method. Some comparisons are presented to valid the reliability of the present study. In numerical analysis, the effects of the volume fraction, nonlocal parameter, strain gradient parameter, and temperature changes on nonlinear bending and vibration are investigated.
Materials of engineering and construction. Mechanics of materials, Chemical technology
Reducing grain size into nanoscale could effectively enhance the strength of crystalline metals, while there is a critical grain size below which softening occurs as grain size further decreases. This strengthening-to-softening changeover accompanies simultaneous deformation mechanism transition from dislocation mediated to grain boundary (GB) mediated processes. To improve the strengthening effects, dislike the conventional nanosheets and laminated graphene embedded in graphene reinforced metal-matrix composites (GRMMCs), here a strategy is presented, via molecular dynamics simulations, to derive a new GRMMC in the form of nanoscale Cu grains fully enclosed by graphene-boundary (GrB). It is demonstrated that the strong dislocation storage and lacking conventional GB-mediated mechanisms in the designed GRMMC could result in extremely high strength of 8.77 GPa and pronounced strain hardening rate compared with nanocrystalline Cu. The design of GB engineering through replacing metallic GBs via GrBs may pave a new way to tailoring GRMMCs without anisotropic limitations, realizing excellent strength and strain hardening capacity. Keywords: Grain boundary engineering, Graphene, Metal-matrix composite, Strength, Molecular dynamics simulation
Materials of engineering and construction. Mechanics of materials
Abstract: A seamless graphene inverter including graphene nanoribbon field effect transistor (GNRFET) and graphene interconnect is proposed. The seamless structure is suggested to eliminate the ohmic, schottky, and parasitic resistances in the junction of the traditional interconnects with the Gate, Source and Drain of GNRFET. After that, using the circuit models of the graphene devices that are used in the proposed structure, transfer matrix model of the proposed seamless graphene inverter is calculated and extracted. All of the capacitive, inductive and scattering effects are included in the assumed circuit models of the GNRFET - graphene interconnect and consequently in the overall matrix model of the seamless graphene inverter. Elimination of the ohmic, schottky and parasitic resistances causes to improve in the working speed of the proposed inverter. Extraction of the transfer matrix model of the seamless graphene inverter and calculation of its step time response, relative stability and frequency bandwidth confirms this improvement. The advantage of the transfer matrix model of the proposed inverter is that any change in the physical parameters of the graphene nanoribbons that are used in the structure can be included in the model and one can analyze the effect of it in all of the technology nodes. Using the circuit model and the extracted transfer matrix, anyone can evaluates various stability analyses such as Nyquist, Bode and Nichols together with the time-frequency responses of the graphene seamless inverter used in very large scale integrated (VLSI) circuits.