Engineering Support Research Articles

Regionalized ensemble estimation of wave periods for assessing wave energy resources across Canada. Part II: Wave-period and wave-energy analyses

The cornerstone for harnessing and utilizing wave energy resources lies in the precise and thorough estimation and assessment of wave energy fluxes through advanced modeling of wave periods. This study implements the developed macroscale regionalized ensemble wave-period modeling (MREWPM) method to accomplish the initial integrated estimation and analysis of wave periods and wave energy fluxes across Canada, complemented by advanced estimations of wave heights and wind speeds. The results indicate that Canadian wave periods lengthen in shallow, low-backscatter, southern, remote, or eastern waters, and exhibit temporal variability in breezy, low-backscatter, southern, remote, or eastern regions. The trend of wave periods exhibited fluctuations, decreasing before and increasing after the trough (9.06 s in 2004) during cool seasons. Temporal variabilities and trends of wave periods were more fragmented and heterogeneous compared to averages. Canadian wave energy fluxes generally exhibit an increase southward with latitudes. The wave energy typically diminishes from offshore (deep waters) to nearshore areas (shallow waters), with this attenuation being more pronounced in winter months. There is a rough decrease from winter, autumn, and spring to summer months, mirroring the seasonal variations of wave periods. This seasonality tends to be more pronounced in highly energetic regions, such as the Pacific and Atlantic oceans. This study enhances reliability and feasibility of macroscale wave-period and wave-energy estimation and analyses, offering scientific support for wave energy development, wave climatology, and ocean engineering.

Unifying Model Execution and Deductive Verification with Interaction Trees in Isabelle/HOL

Model execution allows us to prototype and analyse software engineering models by stepping through their possible behaviours, using techniques like animation and simulation. On the other hand, deductive verification allows us to construct formal proofs demonstrating satisfaction of certain critical properties in support of high-assurance software engineering. To ensure coherent results between execution and proof, we need unifying semantics and automation. In this paper, we mechanise Interaction Trees (ITrees) in Isabelle/HOL to produce an execution and verification framework. ITrees are coinductive structures that allow us to encode infinite labelled transition systems, yet they are inherently executable. We use ITrees to create verification tools for stateful imperative programs, concurrent programs with message passing in the form of the CSP and Circus languages, and abstract system models in the style of the Z and B methods. We demonstrate how ITrees can account for diverse semantic presentations, such as structural operational semantics, a relational program model, and CSP's failures-divergences trace model. Finally, we demonstrate how ITrees can be executed using the Isabelle code generator to support the animation of models.

Intelligent Inversion Analysis of Surrounding Rock Parameters and Deformation Characteristics of a Water Diversion Surge Shaft

The water diversion surge shaft is vital for a hydropower station. However, the complex geological properties of the surrounding rock make it challenging to obtain its mechanical parameters. A method combining particle swarm optimization (PSO) and support vector machine (SVM) algorithms is proposed for estimating these parameters. According to the engineering geological background and support scheme, a three-dimensional model of the water diversion surge shaft is established by FLAC3D. An orthogonal test is designed to verify the accuracy of the numerical model. Then, the surrounding rock mechanical parameter database is established. The PSO-SVM intelligent inversion algorithm is used to invert the optimal values of the mechanical parameters of the surrounding rock. The support for excavating the next layer depends on the mechanical parameters of the current rock layer. An optimized design scheme is then compared and analyzed with the original support scheme by considering deformation and plastic characteristics. The research results demonstrate that the PSO-SVM intelligent inversion algorithm can effectively improve the accuracy and efficiency of the inversion of rock mechanical parameters. Under the influence of excavation, the surrounding rock in the plastic zone mainly fails in shear, with maximum deformation occurring in the middle and lower parts of the excavation area. The maximum deformation of the surrounding rock under support with long anchor cables is 0.6 cm less than that of support without long anchor cables and 4.07 cm less than that of support without an anchor. In the direction of the maximum and minimum principal stress, the maximum depth of the plastic zone under the support with long anchor cables is 1.3 m to 2.6 m less than that of the support without long anchor cables and the support without an anchor. Compared with the support without long anchor cables and support without an anchor, the support with long anchor cables can effectively control the deformation of the surrounding rock and limit the development of the plastic zone.

Effects of Inflow Turbulent Coherent Structures on a Small-Scale Wind Turbine in the Atmospheric Boundary Layer of Long Corridor Terrains: An Example Study in the Hexi Corridor

Considering its Venturi effect, long corridor terrain is considered as one of the outstanding wind-energy resources, but has not been developed due to unclear inflow turbulence effects on wind turbines. To advance the wind-power technology in long corridors and reveal the physics behind it, we conducted a series of data-fusion analyses combining field measurements in the Hexi Corridor, Gansu, China, and numerical simulations and summarize the effort here. In this study, the classical spectrum for the atmospheric boundary layer for wind-energy research, the IEC Kaimal spectrum (also known as IECKwind, International Elector technical Commission 61400-1) cannot describe the wind profile in corridors. Here, we proposed a new spectrum to describe the wind in the Hexi Corridor by modifying the IEC Kaimal spectrum, and we call it the IECK-HX spectrum. The results demonstrate that it preferentially resides at lower frequencies (larger spatial scales) compared with IECKwind. Large-scale motions (LSMs) and very large-scale motions (VLSMs) coexist in the Hexi Corridor atmospheric boundary layer, which can be well described by the IECK-HX spectrum, and these two dominate the large fluctuations in the power, thrust, and blade root flapwise moment of wind turbines, while the high-frequency small-scale coherent structures mainly cause high-frequency fluctuations in wind-turbine load. Furthermore, IEC Kaimal spectrum can not describe the VLSMs, and the generated flow presents significant fluctuations and thereby reduces the power output in high wind-speed regions. This study provides fundamental support for wind-energy scientists and engineers who are interested in wind energy in corridor terrains. Published by the American Physical Society 2024

Optimization of Advanced Support Parameters of Surrounding Rock in Tunnels Constructed by ADECO-RS

So as to efficiently address the distortion of surrounding rock in tunnels constructed utilizing ADECO-RS, it is crucial to define suitable parameters for advanced support systems. This study took the 8 # tunnel in the F3 portion of the E60 Expressway in Georgia as an engineering case. Initially, the original support scheme underwent systematic monitoring and analysis in the field. Subsequently, the FLAC3D 6.0 software was employed to examine the influence of the advanced pipe roof and tunnel face fiberglass bolts on the steady state of the surrounding rock. Optimization of the support parameters was also proposed. Further, the sensitivity of different parameters to the distortion of the rock surrounding the tunnel was analyzed and ranked via an orthogonal experiment. Ultimately, the effectiveness of the optimization scheme was evaluated by numerical methods and field observations. The findings of the research indicate the following: (1) The monitoring results of the original support parameters show that the irrational design of the support parameters can bring about deformation non-convergence in the tunnel’s surrounding rock. Support parameters must be optimized. (2) The spacing of the pipe roof is positively correlated with the distortion of the surrounding rock. In contrast, the length and the grouting strength are negatively correlated with the distortion of the surrounding rock. The reinforcement density, length, and lap length of glass fiber bolts exhibit an inverse relationship with the distortion of the surrounding rock. (3) The efficacy of pipe shed grouting in mitigating subsidence and deformation of the vault is superior, followed by the spacing of the supports. In contrast, the length of the supports demonstrates comparatively lesser effectiveness. Under optimal parameters, the vault subsidence was reduced by 23.2%, 10.2%, and 2.0%, respectively. The most significant factor controlling the extrusion deformation of the tunnel face is bolt lap length, followed by reinforcement density and then reinforcement length. Extrusion displacement was reduced by 52.5%, 40.3%, and 9.3%, respectively, under the optimal parameters. (4) In comparison to the primordial support system, the optimized support scheme reduces the subsidence of the vault by about one time and the convergence deformation around the cave by about two times. The research findings offer guidance for analogous engineering support design and parameter optimization.

Geomechanical modeling aspects in support of hydraulic fracturing operations

This paper describes the main aspects and nuances of geomechanical modeling that must be considered when supporting hydraulic fracturing operations and providing engineering support of projects. A key feature of geomechanical modeling for hydraulic fractures aims or self-induced fracturing in mature fields is the estimation of reservoir pressure, particularly in the vicinity of production and injection wells. In addition, this has a significant impact on stress anisotropy, which is the primary factor affecting the geometry of the hydraulic fracture and the surrounding induced stress field. It is also crucial to monitor geomechanical core studies, ensure quality control of samples, and accurately process research results since the profiles of elastic-strength properties and stresses depend on these factors. This paper also addresses fracturing, including its measurement, calculations, and the prediction of its spatial orientation and intensity.

Onboard test-based exhaust emission factors for marine diesel engines on anchor handling tug supply vessels

In order to accurately assess China’s port air pollution caused by AHTS (Anchor Handling Tug Supply Vessels) ships, 46 diesel engines on 27 AHTS ships were tested for onboard emissions using a large gas analyzer to statistically analyze their fuel-based and power-based emission factors. The results show that fuel-based NOx-emission factors for MEs, SEs and AEs before and after the use of the SCR system are 45.4, 38.24,33.04 g/kg and 6.35, 4.98, 5.82 g/kg, CO-emission factors are 7.95, 6.30, 7.96 g/kg and 6.90, 6.93, 8.32 g/kg, THC-emission factors are 0.49, 0.64, 0.25 g/kg and 0.42, 0.47, 0.22 g/kg, and CO2-emission factors are 3121.62, 3121.34, 3093.12 g/kg and 3088.14,3091.40, 3085.21 g/kg, respectively. Power-based NOx-emission factors for MEs, SEs and AEs before and after the use of the SCR system are 9.71, 8.61, 7.58 g/(kW·h) and 1.37, 1.23, 1.33 g/(kW·h), CO-emission factors are 1.71, 2.08, 1.84 g/(kW·h) and 1.47, 1.53, 1.93 g/(kW·h), THC-emission factors are 0.10, 0.14, 0.05 g/(kW·h) and 0.09, 0.13, 0.06 g/(kW·h), and CO2-emission factors are 671.73, 700.58, 718.46 g/(kW·h) and 664.42, 694.16, 716.92 g/(kW·h), respectively. The power-based emission factor is closely related to the diesel engine load, and the relationship between different exhaust emissions and diesel engine load shows different patterns. In addition, it was found that the NOx emissions of the ship decreased significantly to meet the IMO Tier III requirements after running SCR. The emission factors of CO, HC and CO2 have no obvious change whether SCR systems were operated or not. The AHTS marine engine emission factors obtained in this paper are highly relevant and can provide reliable data for establishing a suitable emission inventory for medium and high speed engineering support vessels.

The Role of the Pancreatic Extracellular Matrix as a Tissue Engineering Support for the Bioartificial Pancreas.

Type 1 diabetes mellitus (T1DM) is a chronic condition primarily managed with insulin replacement, leading to significant treatment costs. Complications include vasculopathy, cardiovascular diseases, nephropathy, neuropathy, and reticulopathy. Pancreatic islet transplantation is an option but its success does not depend solely on adequate vascularization. The main limitations to clinical islet transplantation are the scarcity of human pancreas, the need for immunosuppression, and the inadequacy of the islet isolation process. Despite extensive research, T1DM remains a major global health issue. In 2015, diabetes affected approximately 415 million people, with projected expenditures of USD 1.7 trillion by 2030. Pancreas transplantation faces challenges due to limited organ availability and complex vascularization. T1DM is caused by the autoimmune destruction of insulin-producing pancreatic cells. Advances in biomaterials, particularly the extracellular matrix (ECM), show promise in tissue reconstruction and transplantation, offering structural and regulatory functions critical for cell migration, differentiation, and adhesion. Tissue engineering aims to create bioartificial pancreases integrating insulin-producing cells and suitable frameworks. This involves decellularization and recellularization techniques to develop biological scaffolds. The challenges include replicating the pancreas's intricate architecture and maintaining cell viability and functionality. Emerging technologies, such as 3D printing and advanced biomaterials, have shown potential in constructing bioartificial organs. ECM components, including collagens and glycoproteins, play essential roles in cell adhesion, migration, and differentiation. Clinical applications focus on developing functional scaffolds for transplantation, with ongoing research addressing immunological responses and long-term efficacy. Pancreatic bioengineering represents a promising avenue for T1DM treatment, requiring further research to ensure successful implementation.

Investigation of the impact of micro-nano pore geometry on CH4 adsorption

CH4 is a clean fossil fuel that is widely used in the gas supply of homes and industry, and its energy value is increasingly important. Coal pores provide certain conditions for the storage of CH4. In order to reveal the microscopic adsorption mechanism of CH4 in different pores under high pressure, based on the experimental results, a cross-shaped pore model was proposed, and then molecular simulation was used to construct three kinds of cross-shaped, round and slit pore models for simulation experiment verification. The changes of adsorption parameters, such as adsorption amount, adsorption heat, adsorption energy, adsorption potential and adsorption entropy, were analyzed during the adsorption process. Combined with adsorption and condensation theory, the influence of different geometric pores on the adsorption of CH4 was further verified. The results show that round pore have more adsorption sites, larger adsorption quantity and stronger adsorption capacity, followed by cross pore, while slit pore have the weakest adsorption capacity and least adsorption sites. Under high pressure susaturated adsorption, the interaction force between molecules is stronger, the affinity is higher, the molecules are arranged in order, and the adsorption system is more stable, and the adsorption capacity of slit pore > cross pore > round pore is displayed. This study further verifies the mechanism of the effect of pore geometry on CH4 adsorption, which provides a strong support and theoretical basis for CBM mining engineering.

Influence of Freezing Tunnel Excavation on Foundation Settlement of Buildings

In this paper, the effects of the cement content and excavation speed parameters on the improvement effect of the artificial freezing method and the characteristics of frozen walls are studied by means of a field test, numerical simulation and theoretical model. The optimization effect of the cement content in the artificial freezing method is studied. It is found that 10% is the best content, which can maximize the freezing wall thickness and grouting effect, and promote uniform distribution of the temperature field. At the same time, the influence of the excavation speed on the stress and settlement of the foundation soil is analyzed. It is pointed out that the increase of the excavation speed will aggravate the settlement and stress redistribution, which may threaten the building structure. The evaluation method proposed in this paper verifies that the construction deformation and settlement control are within the safety standards and provides theoretical support and construction guidance for tunnel engineering.

Tensile Deformability of Shotcrete in Tunnel Primary Support: A Case Study

Shotcrete strain in the primary support of a tunnel will produce non-loading strain at an early age due to the influence of its own temperature change, hardening shrinkage, spraying force, and other factors, which means that current strain-monitoring results fail to reflect the real strain, and the strain value after stabilization is high. In addition, tensile strain may be evident in the final result, even exceeding the tensile warning value, but, in actuality, the on-site lining is very stable, with no cracks or damage. Therefore, it is necessary to understand the strain characteristics of shotcrete in the primary support of a tunnel. Based on the long-span tunnel project at Shishan Road Station on the Qingdao Metro Line 6, in situ and indoor pull tests of concrete strain were designed while only considering temperature change, hardening shrinkage, and spraying force. This study shows the following: (1) The strain in shotcrete is greatly affected by temperature changes, hardening shrinkage, and shotcrete force in the first three days, reaching its peak value in the second to third days, while tending to be stable at about the seventh day. (2) The real strain of the shotcrete was tested, and the warning value was adjusted from 90 με to 120 με. (3) The strain value at the third day was taken as the initial value, and the previous monitoring results were revised. The revised results align with the trends shown during real tests performed on-site, providing guidance for tunnel engineering support monitoring.

Architectural Modernization of Main University Building in Novocherkassk

The development of the material and technical base of universities is one of the priority areas of the state policy in the field of creating personnel and technological sovereignty of the country. The high level of modern engineering support and teaching technologies in higher education requires modernization of university buildings throughout the country, some of which are cultural and architectural monuments.Purpose: To consider the possibility of architectural modernization as a means of developing the university's material base on the example of the main university building in Novocherkassk, which is an architectural monument of federal significance.Research findings: Based on an analysis of current problems of this building, of architectural modernization concept is proposed with a change in its functional and space-planning organization.

A Study of the Influence of Engineering Support on the Quality of the Molding Process of Basalt–Plastics Using Vacuum Infusion

A Study of the Influence of Engineering Support on the Quality of the Molding Process of Basalt–Plastics Using Vacuum Infusion

Автоматизированное технологическое обеспечение и повышение эксплуатационных свойств деталей машин

The article outlines two directions of automated engineering support for the operational properties of machine parts (wear resistance, contact stiffness, etc.). The first direction is a traditional one. It's a two-stage provision of the operational properties of machine parts: in the first stage it is the dimensioning of working surfaces quality of the part that determines the required values of operational properties; in the second stage it is technological provision of quality parameters for the working surfaces of machine parts. The second new direction is a single – stage automated engineering support for the current operational properties of machine parts, which has been actively developed over the past 25 years at the Bryansk State Technical University. It is based on the theoretical and experimental dependences of the relationship between the operational properties of machine parts directly with the processing modes of their working surfaces. Various automated systems of scientific research have been developed to obtain experimental dependencies. An example of such an automated system for studying contact stiffness is given. Adaptive control systems used on various machines for high-performance engineering support aimed at obtaining the required quality parameters of the treated surfaces and their operational properties have been developed. When processing new materials and taking into account the absence of theoretical and experimental data, it is possible to use self-learning technological systems. An example of such a system used for a lathe, is given. All these developments contribute to the creation of the machines with artificial intelligence.

Raëlism: An Unconventional Religious Pathway to Transhumanism

Raëlism is a controversial new religious movement that originated in France in the 1970s and has since spread around the world. The movement’s core tenets are rooted in science, technology, and freedom and can be summarized as a blend of science and spirituality, millenarianism, revelation, story, pseudoscience, and reinterpretation. Raëlians believe in the extraterrestrial origin of humanity and promote the pursuit of higher consciousness, inner peace, individual empowerment, and peace-building. To this end, the movement offers a series of seminars that aim to provide a transformative experience for participants and leads various social initiatives and projects at a global level. Although Raëlism has gained popularity among some individuals, it has also been the subject of substantial criticism and controversy, particularly because of its unconventional views on sexuality and its alleged support for human cloning and genetic engineering. Nonetheless, the movement continues to be a subject of interest and scrutiny for scholars, journalists, and the curious. This article provides an overview of the history, ideology, and practices of the Raëlian Movement and its relationship with transhumanism.

Stability Analysis of Breakwater Armor Blocks Based on Deep Learning

This paper aims to use deep learning algorithms to identify and study the stability of breakwater armor blocks. It introduces a posture identification model for fender blocks using a Mask Region-based Convolutional Neural Network (R-CNN), which has been enhanced by considering factors affecting breakwater fender blocks. Furthermore, a wave prediction model for breakwaters is developed by integrating Bidirectional Encoder Representations from Transformers (BERTs) with Bidirectional Long Short-Term Memory (BiLSTM). The performance of these models is evaluated. The results show that the accuracy of the Mask R-CNN and its comparison algorithms initially increases and then decreases with higher Intersection Over Union (IOU) thresholds, peaking at 95.16% accuracy at an IOU threshold of 0.5. The BERT-BiLSTM wave prediction model maintains a loss value around 0.01 and an accuracy of approximately 90.00%. These results suggest that the proposed models offer more accurate stability assessments of breakwater armor blocks. By combining the random forest prediction model with BiLSTM, the wave characteristics and fender posture can be predicted better, offering reliable decision support for breakwater engineering.

Differentiation Strategy and the Performance of Medical Insurance Companies in Kenya

Against a backdrop of escalating global competition, health insurance firms grapple with the need to stand out amidst a saturated market. The study recognizes the imperative for organizations to adopt differentiation strategies, with a focus on product, personnel, distribution, and image differentiation. Acknowledging the current dearth of comprehensive research in the Kenyan context, the research problem centres on the critical need to investigate the extent to which differentiation strategies influence the performance of health insurance companies in the region. The general objective of the study was to investigate the effect of differentiation strategy on performance of Health Insurance Companies in Kenya. Drawing on established theories such as Porter's Competitive Advantage Model, Upper Echelons Theory, Resource-Based View, and Transaction Cost Economics, the study employs a multi-theoretical framework to provide a nuanced understanding of the complex relationships between differentiation strategies and organizational outcomes. Adopting the descriptive research design, the target population comprises 980 employees in the medical insurance firms in the top management and middle level management in Nairobi, drawn from the respective insurance firms’ Human Resources Departments. Employing a multi-stage sampling technique, the established sample size is 101 top and middle level management staff who were reached by stratified random sampling. A semi-structured questionnaire was the main data collection instrument and was distributed through a drop-and- pick- latter approach. Data was analyzed using both descriptive and inferential statistics. Descriptive statistics measures of mean and standard deviation was used, while for inferential statistics, regression equations were employed. The study established that product differentiation strategy, personnel differentiation strategy, product differentiation strategy and image differentiation strategy had a positive significant effect on performance of health insurance companies in Kenya. The study concludes that product differentiation is the key aspect distinguishing one company’s products or services from its competition. Personnel differentiation strategy gives an organization the ability to respond in time to the needs of their members through the skills and knowledge of employees. A differentiated distribution strategy allows insurance companies to expand their sale potential by getting their product in front of more potential customers. An effective image establishes the product's character and value proposition and a person responds differently to company and brand images. The study recommends that the insurance companies should consider opportunities for differentiation in all of its production areas: marketing, product management, engineering, sales, and customer support. Organizations looking to build personnel differentiation strategy will need to produce or design extremely unique or distinctive products or services that create increased value for the consumer. The insurance companies should devote resources to channel management preferably at least one dedicated manager whose sole responsibility is to manage those relationships and build the marketing programs to drive revenue through the channel. The insurance companies should identify their brand gaps, which are the discrepancies between their desired and actual brand performance.

An Overview of the Most Effective Technical Means Used for Various Military Engineering Mission, with Highlights on Their Interoperability

Abstract We could mention that currently we cannot speak, at the level of the NATO Alliance, of the existence of interoperability of engineering structures, from all partner armies, in terms of providing them with high-performance technical means, intended to ensure timely and efficient engineering support. This is based on the analysis we carried out on ensuring the interoperability of engineering structures participating in multinational missions and exercises, from the perspective of providing them with modern technical means, in order to fulfill the engineering support missions, after some exchanges with partners from Hungary, the Czech Republic, Slovakia and the multinational exercises that colonel Mircea VLADU led as director or co-director, between 2011 and 2013 in Romania, Hungary and Croatia. On these occasions, we were able to as certain that the engineering structures of the armies that were part of the Warsaw Treaty are predominantly equipped with technical engineering means from 80s, some purchased from the former USSR and others manufactured within their own defense industries, a situation that continued even after the integration of the respective states into NATO, as a result of the allocation of some percentages of the GDP, below the level of the commitments and at the same time the support with insufficient funds of the endowment proposals with efficient means, according to NATO standards. Considering these elements, we would like to further present some considerations aimed at equipping NATO engineering structures with the most efficient technical means for the execution of engineering research operations.

COMPARATIVE EXERGY ANALYSIS OF ADIABATIC AND ISOTHERMAL HUMIDIFICATION IN A DIRECT-FLOW CENTRAL AIR CONDITIONING SYSTEM

Central air conditioning systems of buildings and structures are significant consumers of electric and thermal energy of different temperature levels and are the least economical in terms of energy consumption. When designing these systems, due attention is not always paid to assessing their energy efficiency and no variant design is carried out with a comparison of the relevant indicators. This is due to the lack of proven engineering methods. The exergy method of analysing energy-consuming systems provides a correct numerical assessment of energy efficiency and enables a comparative analysis of circuit solutions and system elements. In contrast to the energy method, the peculiarity of the exergy method in relation to air conditioning systems is the possibility of taking into account all available mass and energy flows in the system in exergy units. The extension of the exergy method to systems for creating and maintaining a microclimate in buildings and structures has not yet acquired the status of practical engineering support. This article presents an example of an exergy analysis based on the original methodology for comparing methods of humidification in a central air conditioning system for a public building in order to select the best method in terms of energy efficiency. Two traditional methods of air humidification for the cold season - adiabatic and isothermal - were used for the study and comparison. The results of analytical studies are presented in the form of relative values of exergy.

A Study of Multibeam Line Measurement Problems Based on Analytic Geometry and Mechanistic Analysis

Based on the important application of multibeam bathymetric systems in marine science and engineering, this study explores their working principle and application potential. Through the establishment of a mathematical model, problems such as coverage width and distance between survey lines are solved, and an optimized survey line layout scheme is proposed. For the seabed topography data, combined with geometric analysis and visualization technology, accurate measurement and analysis of seabed topography is realized, which provides important support for marine survey, resource exploration and underwater engineering. The research results are of guiding significance for the further development and application of multibeam bathymetry technology and provide strong support for research and practice in related fields.