Heavy Load Research Articles

Development of Static Test Equipment and a System for Lever-Loaded Air Springs

In light of the heavy load applied by traditional air spring test equipment and its complex structural system design, a lever-type torque loading air spring test system is designed. It adopts the principle of Chinese scales to apply the load on the air spring in the form of proportional amplification, which can apply a simulated load on the air spring of 500–800 kg, using the vertical sliding shaft as the transverse limit to make the air spring elongate and compress by 280 mm in the longitudinal direction. The measurement and control system of the test equipment is then developed based on the LabVIEW platform, and the required sensors are selected and installed. The system can achieve real-time data acquisition of the air pressure, load, height and other parameters of the air spring and air spring charging and discharging control. Following the debugging of the function of the test equipment, the function of each subsystem is normal and able to meet the requirements of air spring characteristic and pressure tightness tests. For small spaces, such as laboratories, by reducing the installation of hydraulic and other oil source systems, avoiding the use of large mass blocks to simulate the loading of air spring loads and optimizing the complex installation and debugging process, this miniaturized design for air spring test equipment has benefits for practical applications.

Pavement structures for extra heavy loads at multimodal traffic terminals

The subject matter of this study entails a brief overview of some of the methods for dimensioning pavement structures at container terminals, primarily located within ports and within freight rail stations, designed to withstand the loads imposed by very heavy vehicles (Heavy Duty Pavements). Within this study, an examination is provided on the methods for dimensioning cement concrete pavement structures for non-standard axle loads, as well as the results obtained through the application of these methods.

Fabrication of gradient structure for enhancing wear resistance of GCr15 bearing steel friction shim

The wear resistance of metallic shims under heavy load is crucial for the friction behavior of friction damper in civil engineering. This study verifies the potential of the strengthening grinding process (SGP) to enhance the wear resistance of metallic materials under heavy load. A multidisciplinary effort is shown in this paper to investigate the wear mechanism of SGP-treated GCr15 bearing steel in terms of the application scenario of civil engineering. The SGP treatment uses a multiphase abrasive comprising steel balls, corundum powder, and strengthening liquid to impact the surface of the GCr15 bearing steel. Then, a dry friction sliding test was performed on the polished, sandblasted, and SGP-treated GCr15 bearing steel. The microtopography and microstructure of these three friction shims with different treatments before and after the wear test were compared and analysed. The test results indicated the feasibility of SGP in enhancing the wear resistance of GCr15 bearing steel friction shims under heavy loads in terms of the application scenario of civil engineering. The SGP-treated sample had a more stable friction coefficient (0.475) and slighter wear compared to the other two samples due to its enhanced layer with a gradient structure and a thickness of approximately 23 μm.

A Novel Proposal for an Adapted Vehicle for Informal Waste Pickers in Ambato – Ecuador

Solid waste management represents a challenge for contemporary cities because it involves various levels of management and processing. At the base of the recycling pyramid, the crucial role of informal recyclers stands out, whose work improves the environmental conditions of cities. Despite its valuable contribution, informality has marked this profession, with deplorable working conditions at a social and economic level and low occupational safety. Recyclers roam the city in search of as much recyclable material as possible, so they can later sell it and continue the chain. However, the operational process of the recyclers is striking due to the inadequate conditions, in terms of personal protection and mobilization. Traditionally, they move with a cart, a product intended for transporting heavy loads over short distances. However, it is used by waste pickers to travel long distances during the daily working day. Through the methodology of early and continuous validation for product design, a vehicle adapted for the work of informal recyclers in the city of Ambato is proposed. It shows a valuable vision of addressing management in an inclusive, effective way for the city, with adequate working conditions at the operational level for waste pickers.

Features of operation of tracked forest vehicles in the cryolithozone and ways to increase its efficiency

The article shows that in the harsh natural and industrial conditions of the cryolithozone forests associated with extremely low temperatures in winter, heavy loads on the transmission and crawler during various forestry operations in the warm season, a reliable and efficient lubrication system is necessary. For this, natural serpentinite is best suited, which, like a hydrogel, absorbs transmission oil, and getting into the friction zone, begins to release it. It is determined that the money savings associated only with an increase in the durability of the caterpillar propulsion joints, due to the use of serpentinite, for one tracked forest tractor by 35 %, will amount to 3,450 rubles.

Analisis Penerapan Latihan Fisik Pada Siswa Sekolah Dasar

Exercise is a body movement carried out by muscles in a planned, structured and repetitive manner, which involves the use of energy to improve fitness. According to the World Health Organization (WHO), school age children are children aged 7 to 15 years. Every individual has traits and characteristics or innate characteristics and characteristics obtained from environmental influences. The research method used in this research is descriptive analysis with a qualitative approach. This research uses a qualitative approach. Physical activity is an important aspect in the lives of elementary school age children. Elementary school age children still have limitations in terms of body endurance and ability to adapt to heavy training loads. Primary school age children are in a dynamic stage of development, so there is a need for specially designed training programs to increase their motivation and participation in physical activity. In this way, the benefits of physical activity can be maximized and support optimal growth and development for elementary school students. This collaborative effort will help create an environment that supports an active and healthy lifestyle from an early age.

The optimization design for the journal-thrust couple bearing surface texture based on particle swarm algorithm

Journal-thrust coupled bearings (JTC bearings), unlike conventional journal or thrust bearings, require consideration of both reducing friction coefficient in the journal part while increasing the load-carrying capacity in the thrust part during lubrication design. This study established a thermal-elastohydrodynamic mixed lubrication model for JTC bearings considering flow, pressure, and thermal continuity conditions, validated through experiments. Based on this, the influence of texture parameters on lubrication under real heavy load conditions was preliminarily investigated. The orthogonal test design was then used to determine the texture parameter that had the greatest impact on optimization. Subsequently, particle swarm optimization (PSO) algorithm was employed for synchronous optimization design of textures for both journal and thrust parts.

Plate-type metastructure with low-frequency sound insulation and high stiffness properties

According to the mass law, it is impossible to increase sound transmission loss (STL) of conventional structures at low frequencies without increasing their weight. Metastructures are capable to break the limits of the mass law at low frequencies. However, many existing sound insulation metastructures need to be constructed using a host structure with low-stiffness properties, such as a thin plate and a thin membrane. As a result, the metastructures normally have large exposed areas with low-stiffness characteristics and are unable to bear heavy loads, which limits their practical applications. In this work, we propose a high-stiffness plate-type metastructure (HSPM) with both low-frequency sound insulation performance and high stiffness properties. The STL performance of the HSPM is demonstrated analytically, numerically and experimentally, indicating that the HSPM can deeply break the mass law at low frequencies. Owing to the simple construction, high stiffness properties, and high sound insulation performance at low frequencies, the proposed HSPM has promising applications in practical noise control engineering.

COSIER: A comprehensive lightweight blockchain system for IoT networks

Internet of Things (IoT) networks have spread to many important fields and applications. The security of these networks remains a big challenge due to their unique characteristics and delicate operations. The blockchain has recently been proposed as a system to secure IoT data and communications. However, the blockchain demands a heavy load that cannot be handled by light IoT devices. For this reason, a large number of “lightweight blockchain” solutions were proposed that aim to modify the blockchain structure and characteristics to make it suitable for IoT networks. In this paper, we propose a novel and unique blockchain system for IoT networks that is based on four lightweight features: “lightweight architecture”, “lightweight authentication”, “lightweight consensus”, and “lightweight storage”. While previous research works focused on one or two of these features, we propose a system that combines the four features into a comprehensive lightweight blockchain system that utilizes a “lightweight cryptography” mechanism to achieve better performance from several perspectives, such as transaction latency, block generation delay, network overhead, and resilience to attacks.

Stability Analysis of Open-Pit Bench Slope under Repeated Heavy Vehicle Loading Based on Stress-Corrosion Model

In the present study, we address an important and increasingly relevant topic in mining safety and efficiency, namely the stability of open-pit bench slopes subjected to daily heavy truck cyclic loading. Specifically, we focus on the stability of Zhahanur open-pit slope (Inner Mongolia region, China) and investigate the potential role of daily heavy truck cyclic loading in bench slope instability. To this end, we incorporate a stress corrosion model into the particle flow code to develop a time-dependent deformation model of the rock. With the established model, we quantitatively analyse the effect of heavy truck cyclic loading on the bench slope stability. Our results support the hypothesis that daily heavy truck loading can cause gradual downward deformation of a rock mass, leading to slope instability. To validate our numerical modelling results, we compare and analyse them with in situ monitoring data. Our study demonstrates the significant impact of daily heavy vehicles on bench slope stability in open-pit mines and provides a practical tool for assessing the long-term stability of open-pit bench slopes and optimising mining operations.

An Overview of Design and Optimization of an Industrial Shed With Gantry Girder

The main focus of this project study is to explore and compare the design and optimization of two types of industrial sheds: Pre-Engineering Building (PEB) with gantry girder work and the traditional truss-type steel shed with a gantry girder. PEB structures stand out for their efficiency and quick assembly due to pre-made components assembled on-site. Including a gantry girder in the design supports cranes for lifting heavy loads. On the other hand, the traditional steel shed design also features a gantry girder for crane support and is a staple in the construction sector. By analyzing these designs using STAAD-Pro software, we evaluate factors like strength, construction time, cost efficiency, and suitability for various industrial needs. Through this comparison, we aim to provide valuable insights for construction professionals to determine the most suitable shed design for their specific requirements, ensuring optimal performance and operational efficiency in industrial settings.

Research on the Scale Fire Test and Fire Resistance of the One-Way Slab of a Metro

To address the difficulty in conducting fire tests to verify the fire-resistance limit of large one-way slabs with heavy loads in a metro, a scale fire test method is proposed based on the bearing capacity calculation of the one-way slab under fire. The scale fire test method adapted the hypothesis that the deflection of the one-way slab under fire is close to a half-sine function and the plane section hypothesis. The validity of this hypothesis is verified through fire tests and finite element simulations. The scale fire test method achieves a similar temperature field and mechanical behavior between the scaled model and full-scale model of the one-way slab. The results of the fire tests showed that the temperature field and mechanical behavior of the scaled model were consistent with those of the full-scale model, with an error in fire resistance of 4.7%. The calculation results and fire test results are essentially consistent, with an error of 6.5%, and according to the calculation of the one-way slab fire-resistance limit, the key factor affecting the fire resistance of the one-way slab under fire is the temperature of the bottom rebars. Using the scale fire test method, the size effect of the one-way slab under fire still exists, and larger slabs have a greater deformation capacity.

Natural colonizers effectively restore heavy metal polluted wasteland

In India, ∼30% of total land is degraded due to pollution, salinization, and nutrient loss. Change in soil-quality at urban waste-dumping site prior and after cow-dung amendment was compared with control agriculture soil. The soil at waste-dumping site had elevated pH, EC, temperature and lowered OC and NPK concentrations when compared to control. Polymetallic pollution of Cr, Cd, Pb, and Ni beyond permissible limits was obtained. Cow-dung amendment restored soil physicochemical properties at the waste-dumping site, with increasing soil moisture, CEC and OC; however, a slight change in soil bulk-density and heavy-metal concentration post-amendment was noted. The seven natural colonizers present at the waste-dumping site accumulated more metals in roots than shoots. Datura innoxia had maximum bioaccumulation of Cr, Calotropis procera of Cd and Ni and Parthenium hysterophorus of Pb in roots. All these plants had Bioacccumulation factor (BAfroot )>1 and translocation factor (Tf) <1 for Cd and serve as its phytostabilizer except Calotropis procera which had BAfroot >1 and Tf >1 and is identified as a phytoextractor for Cd. Cow-dung amendment alone appeared to be insufficient and additionally the revegetation of natural colonizers is recommended for effective reduction in heavy metal load and improving overall soil health at wasteland. Such eco-restoration may also minimize risks to biodiversity in India.

Quantification of regulated metals in recycled post-consumer polypropylene through comparative ICP-MS, AAS and LIBS analyses

Knowing the exact heavy metal load of recycled plastics is important for their risk assessment. We therefore established a novel strategic hierarchy for testing the heavy metal load of recycled plastics. For preliminary screening for unusually high elemental loads, laser-induced breakdown spectroscopy (LIBS) is suggested, while inductively coupled plasma-mass spectrometry (ICP-MS) or electrothermal atomic absorption spectroscopy (ETAAS) are used for exact quantification. The contents of ten regulated elements (Hg, As, Cd, Cr, Co, Cu, Se, Pb, Sn and Ni) in post-consumer (PCR), post-industrial (PIR), and virgin polypropylene (PP) were thus determined. Concentrations in the PCR were mostly found to be two orders of magnitude smaller than their threshold in non-food applications. Cu was most abundant in PCR with 18.7 ± 6.1 mg/kg. Concentration variations of approx. 30 %. were found within a PCR batch, while between batches, slightly higher variations of 30–40 % were observed. Moreover, the heavy metal concentration patterns of PCR and PIR differ significantly. This strategy may enhance the applicational possibilities for PCR.

Biomechanics of Bruxism Potentially Determine the Sites of Severe TMJ Osteoarthritis

The objective of this study was to assess the osteoarthritis (OA) disease severity in 47 temporomandibular joints (TMJs) using a validated scale for gross signs of OA while noting the specific sites for profound disease on the donor condyle and fossa. A disease severity score of Grade 0–4, representing absent to severe disease, was awarded to each specimen’s condyle and fossa by two blinded investigators who have demonstrated interrater reliability. The mandibular fossa was more pathological compared to the mandibular condyle (* p = 0.001). When the deepest focal lesions were qualitatively assessed, it was demonstrated that the mandibular fossa was more severely degenerated than the articular eminence in 58% of donors. In this subpopulation, 74% of the severe mandibular fossa pathology was seen on the deep articular surface. When the articular eminence was the most severely degenerated region of the fossa, it was equivalently likely to see severe focal lesions on the lateral eminence (35%) or equally distributed across the entire eminence (35%). The greatest disease severity was discovered in sites of overloading, which may be associated with paranormal mandibular movements and potentially bruxism. Patients with bruxism produce significant translational movements (grinding) in the upper joint compartment and heavy vertical loading (clenching). Theoretically, this amplifies pressure and inflammation on the lateral articular surfaces and in the deep fossa.

Prominent antidiabetic and anticancer investigation of Scrophularia deserti extract: Integration of experimental and computational approaches

Diabetes mellitus (DM) is a group of syndromes and complications characterized by hyperglycemia, metabolic disorders in lipids, carbohydrates, and proteins. It causes an increased risk of vascular complications. A methanolic extract of Scrophularia deserti was found to reduce blood glucose in basal conditions and after heavy glucose load in normal rats. S. deserti extract lowered the hyperglycemia in streptozotocin-induced diabetic rats (33.33 % at 200 mg/kg, 41.43 % at 400 mg/kg, 2-, and 4-hours following administration when compared to standard glibenclamide (52.05 %). Furthermore, the in vitro activity of the extract was screened against two major diabetes targets; human α-glucosidase and human α-amylase, and showed 88–87 % inhibition effect compared to reference drugs. In addition, the Scrophularia deserti extract was assayed for detection of its antioxidant assay as a free radical scavenger. In the cytotoxicity experiment, the extract exhibited a good cytotoxic selectivity to cancer over normal cell lines. Herin, we categorized all active components existing in the plant extract as defined by LC-MS tool for further computational studies. Certain molecular modeling studies have been done including docking experiments and molecular dynamic simulations for the most predicted potent active metabolites; Caffeic acid 3-glucoside and 1-O-feruloyl-β-d-glucose. The results revealed good binding and stability behavior within the active sites of both targets.

Understanding Women's Transitions from Military to Department of Veterans Affairs Care.

Background: Over the past two decades, increasing numbers of women have served in the military, with women now comprising 17.3% of active-duty personnel and 21.4% of National Guard and reserves. During military service, women often incur painful musculoskeletal (MSK) injuries related to carrying heavy loads and wearing ill-fitting gear. While women may receive initial care for these injuries under the auspices of the Department of Defense (DoD), these injuries often linger and further treatment in required as women transition to Department of Veterans Affairs (VA) care. However, little is known about this transition process, and whether women are given adequate information and support regarding how to access VA care after their military service has ended. Research Design: To better understand these issues, we interviewed 65 women veterans with military service-related MSK injuries about their transition from DoD to VA care. Results: Six major themes emerged from the interviews. Those themes were: (1) Military injuries are often related to ill-fitting gear or carrying heavy loads; (2) Stigma/discrimination related to military injuries; (3) Limited assistance with transition between DoD and VA to manage ongoing injuries and pain; (4) Women have a difficult time managing perceptions and expectations of their weight after military service; (5) Childcare is a substantial burden for veterans in self-care; and (6) veterans desire peer-support services to help them stay healthy. Conclusions: Based on these findings, DoD and VA should continue to work together to develop programs to educate and support women as they transition from military to VA care. Furthermore, VA should consider developing peer support programs for women Veterans who may require additional support to maintain health, especially among Veteran mothers who have complex family responsibilities that may limit their ability to focus on their own health.

Semi-Kinematic Coupling Design and Analysis for Giant Steerable Science Mirror Prototype of Thirty Meter Telescope.

The Giant Steerable Science Mirror prototype is being developed to assess the tertiary mirror system of the Thirty Meter Telescope. In this study, a new semi-kinematic coupling design is proposed for the prototype based on three pairs of V-grooves and canoe-like components to allow for high repeatability accuracy under heavy loads. A mathematical model was constructed to estimate the repeatability accuracy using the corresponding measurement results and machining errors. The proposed design was verified by an experiment, and the results were consistent with the mathematical model. Furthermore, the results indicate that the repeatability of the semi-kinematic coupling is sufficient for the requirement.

Impacts of heavy-duty electric trucks on flexible pavements

ABSTRACT The transportation sector is responsible for significant greenhouse gas (GHG) emissions, with medium- and heavy-duty trucks (MHDTs) being major contributors. In response, medium- and heavy-duty electric trucks (MHDETs) are being explored as zero-emission alternatives. However, the weight of high-capacity batteries needed for long-haul trips and heavy loads could increase the axle loads as well as the gross vehicle weight (GVW) of heavy-duty electric trucks (HDETs), leading to extra damage on flexible highway pavements. This study simulated the GVW increment of HDETs and assessed its effects on pavement damage, environmental impacts, and life-cycle costs of four typical highway pavement structures in Illinois (known as thick–weak, thick–strong, thin–weak, and thin–strong). The utilisation of electric trucks resulted in significant reductions in diesel combustion related global warming potential (GWP) emissions and costs (in $2022) by 73% and 11.5%, respectively. However, the results demonstrated that with a 100% penetration of HDETs carrying an additional weight of 8 kips per truck, the pavement deterioration accelerated compared to traffic with conventional trucks. As a consequence, GWP and costs were reduced by 69% and 10.6%, respectively.

Fault Detection and Diagnosis of Three-Wheeled Omnidirectional Mobile Robot Based on Power Consumption Modeling

Three-wheeled omnidirectional mobile robots (TOMRs) are widely used to accomplish precise transportation tasks in narrow environments owing to their stability, flexible operation, and heavy loads. However, these robots are susceptible to slippage. For wheeled robots, almost all faults and slippage will directly affect the power consumption. Thus, using the energy consumption model data and encoder data in the healthy condition as a reference to diagnose robot slippage and other system faults is the main issue considered in this paper. We constructed an energy model for the TOMR and analyzed the factors that affect the power consumption in detail, such as the position of the gravity center. The study primarily focuses on the characteristic relationship between power consumption and speed when the robot experiences slippage or common faults, including control system faults. Finally, we present the use of a table-based artificial neural network (ANN) to indicate the type of fault by comparing the modeled data with the measured data. The experiments proved that the method is accurate and effective for diagnosing faults in TOMRs.