Engineering Activities Research Articles

Quantifying flow regime impacts on hydrodynamic heat transfer in rough-walled rock fractures

Hydrodynamic heat transfer in rock fractures is crucial for many geophysical processes and engineering activities, notably in harnessing geothermal energy. Despite extensive research, characterizing hydrodynamic heat transfer in rock fractures, complicated by their geometric heterogeneity, remains a formidable challenge. To address this challenge, we experimentally investigated the hydrodynamic heat transfer in rock fractures with diverse geometric features at steady-state elevated temperatures. We found that both heterogeneous fracture geometry and elevated temperatures promote the transition of fracture flow from a linear to nonlinear regime. This flow regime transition enhances the heterogeneity of heat transfer intensity within the fracture and exacerbates the increase in heat transfer efficiency with flow rate. At a fortyfold increase in flow rate, the heat transfer coefficient in the most heterogeneous fracture rises by approximately 72 times, compared to about 28 times in the least heterogeneous one. Leveraging experimental data, we developed parametric models linking heat transfer coefficients, outflow temperature, and heat recovery rate to flow rate and geometric features, yielding a theoretical formulation for the maximal heat recovery rate. By introducing the concept of an energy conversion rate, we quantitatively evaluated the effect of nonlinear flow resistance on heat extraction feasibility, revealing that energy conversion rates in highly heterogeneous fractures can be up to 452 times lower than in less heterogeneous ones. This highlights the pivotal role of flow resistance in heat extraction feasibility. Our findings are instrumental for understanding and predicting the hydrodynamic heat transfer within fractured geothermal reservoirs and analogous hydro-thermal systems.

An appraisal of the LQI as an approach to setting target reliabilities in ISO 2394:2015

The idea of coupling economics and safety into one optimization exercise, and hence deriving target reliabilities explicitly from socio-economic consequences of limit state violation, appeared in the JCSS Probabilistic Model Code around the turn of the century; the effort culminated in the form of a Life Quality Index (LQI)-based marginal lifesaving costs (MLSC) methodology in ISO 2394:2015 for determining maximum acceptable failure probabilities, pT, in life safety limit states for civil engineering structures across all nations. Unfortunately, while the methodology does yield adequate levels of safety when applied to structures in the developed countries, the recommended values of pT turn out to be one to two orders of magnitude higher, and unacceptable to every known standard in the world including its own earlier edition (ISO 2394:1998) when applied to structures in the developing world (exemplified by India) with identical functions and expected fatalities. This arises from two shortcomings: (1) an MLSC approach is generally unable to provide an independent constraint on monetary optimization, and (2) the LQI-based measure of MLSC constraint is strongly dependent on a country’s per capita GDP (g) and the resultant pT is effectively governed by the reciprocal of g. This paper recommends continuing with the absolute − not marginal − consequences of violating life safety limit states, and setting constraints on monetary optimization that are consistent with fatality risks from engineering activities more universally accepted to be safe.

Are Geotextiles Silent Contributors of Ultrashort Chain PFASs to the Environment?

We investigated the presence of per- and poly fluoroalkyl substances (PFASs) in woven and nonwoven polypropylene geotextiles and four nonwoven polyester geotextiles commonly used in modern geosynthetic composite lining systems for waste containment facilities such as landfills. Targeted analysis for 23 environmentally significant PFAS molecules and methods for examining "PFAS total" concentrations were utilized to assess their occurrence in geotextiles. This analysis showed that most geotextile specimens evaluated in the current investigation contained the ultrashort chain PFAS compound pentafluoropropionic acid (PFPrA). While the concentrations ranged from nondetectable to 10.84 μg/g, the average measured concentrations of PFPrA were higher in polypropylene than in polyester geotextiles. "PFAS total" parameters comprising total fluorine (TF) and total oxidizable precursors (TOPs) indicate that no significant precursor mass nor untargeted intermediates were present in geotextiles. Therefore, this study identified geotextiles as a possible source of ultrashort PFASs in engineered lined waste containment facilities, which may contribute to the overall PFAS total concentrations in leachates or liquors they are in contact with. The findings reported for the first time herein may lead to further implications on the fate and migration of PFASs in geosynthetic composite liners, as previously unidentified concentrations, particularly of ultrashort-chain PFASs, may impact the extent of PFAS migration through and attenuation by constituents of geosynthetic composite liner systems. Given the widespread use of geotextiles in various engineering activities, these findings may have other unknown impacts. The significance of these findings needs to be further elucidated by more extensive studies with larger geotextile sample sizes to allow broader, generalized conclusions to be drawn.

Biphasic Liquid Metal Composite for Strain Sensor with High Stretchability and Sensitivity

Strain measurement is crucial for the safety and stability of engineering activities. With the increasing demand for sensors and large strain measurement in engineering monitoring, the study on the large strain measurement is deepening. However, the conventional strain sensors based on rigid conductive materials have limited flexibility and low stretchability, and the research of large strain and flexible sensors in engineering still lacks. In this work, a highly stretchable and sensitive flexible strain sensor based on liquid metal‐Nickle microparticles (LMN) composite is developed to detect large strain. The LMN composite, featuring uniformly dispersed Nickle microparticles within the liquid metal matrix, is deposited onto the elastomer Ecoflex base material.The LMN composite based‐sensor exhibits high sensitivity (GF = 16.14644 at strain of 200%), large stretchability (up to 200%) and low hysteresis. The theoretical relationship between the relative resistance changes and strain is derived, and the theoretical derivation is compared with experimental data to verify the accuracy of theoretical derivation. Additionally, the LMN composite based‐sensors can be used to detect pressure and bending signals in engineering. This work highlights the potential of LMN composite in broad applications and can facilitate the application of flexible sensing devices in engineering.

Exploring Design Principles for STEAM Learning Activities Development by Science and Technology Teachers

This study explored the design principles of science, technology, engineering, arts, and mathematics (STEAM) learning activities developed by science and technology teachers for classroom practice. Through a qualitative approach, interpretive paradigm, and design-based research, 12 Bachelor of Education honours degree students were conveniently sampled. Data were collected by means of reflections and development of learning materials through the analysis, design, development, implementation, and evaluation (ADDIE) model. The study followed the design-based research stages of needs analysis, development, testing, and reflection to produce design principles, and it was underpinned by the learning theory of constructionism. The findings showcase the design principles to include design thinking, finding solutions for learning problems, creativity, and innovation applied to instructional design. The study recommends the use of design thinking pedagogies in developing teacher knowledge on STEAM classroom practice.

Implementation of complex engineering problem solving projects in a Malaysian engineering programme

Accreditation bodies mandate incorporating complex problem-solving (CPS) in engineering programmes on top of outcome-based education. However, its attributes are open to interpretation, leading to a lack of consensus on its implementation in engineering curricula. This paper suggests a solution: having CPS in projects, especially for the courses aligned with CPS-related outcomes. To eliminate ambiguities, the characteristics of complex engineering problems (WP) and complex engineering activities (EA) are restated. This ensures a consistent interpretation of WPs and EAs among educators. CPS projects can be phased into four stages: awareness, adoption, growth, and maturity, followed by continual quality improvement at both the course and programme levels. The entire process can span several years. To stay current with the latest academic and industrial developments, implementation should be completed within one accreditation cycle.

Bioengineering solutions for expansive soil stabilization using waste materials: An experimental evaluation

Municipal solid waste incineration ash is the outcome/product of bioengineering science. The incineration or burning of municipal solid waste (MSW) reduces the volume of this biomass by 90%, and the residual ash can be used in several applications. In this study, the potential of municipal solid waste incineration (MSWI) ash and calcium carbide residue (CCR) waste for stabilization of expansive soil has been experimentally evaluated. The abnormal shrink–swell characteristics of expansive soils pose several problems for civil engineering structures when these soils are used for construction in their original form. The study presents an experimental set-up to determine the best combination of additives to achieve the most favorable technical characteristics of expansive soil for civil engineering activities. The percentage of expansive soil has been kept fixed at 60% of the total weight of the mix for varying ratios of stabilizing agents. The optimization of the stabilizing materials is based on the highest strength parameters of the mix achieved for a particular ratio of additives and soil. The two stabilizing agents are waste materials, and their disposal through landfilling has become costly due to a scarcity of space and handling mechanisms. The values of strength parameters, unconfined compressive strength (UCS), and split tensile strength (STS) of a treated mix are found to be highest for a unique combination of 60% lime stabilized expansive soil and 20% MSWI ash and an equal quantity (20%) of CCR. The cumulative effect of adding the best mix of additives to soil and curing time depicts an improvement of 526.03% in UCS and 463.41% in STS of the mix compared to one day and 28 days of curing time. There is scope for further study, such as adding some fibers to the finalized mix to reinforce the soil mix.

Study on the susceptibility of debris flow disasters in southeast Tibet based on the information content model and random forest model

Linzhi, in southeast of the Tibetan Plateau, has high mountain and gorge terrain. Recently, with rapid changes in climate and fast development of engineering construction in Tibet, the fragile ecological environment in Linzhi has been further damaged, resulting in a sharp increase in debris flow disasters in the region. This poses a serious threat to local social and economic development and safety of lives and property. We divided the study area into multiple watershed units, and explored the reliability of the information content model (ICM), random forest model (RF), and their coupled model (ICM-RF) in the evaluation of debris flow disaster susceptibility. Through remote sensing interpretation, field investigations, and data collection, data on debris flow disasters and evaluation indicators in the study area were obtained. Using multicollinearity analysis, 16 evaluation indicators were selected from 7 major categories including topography, geological conditions, meteorological and hydrological conditions, ecological environment conditions, human engineering activities, seismic activities, and watershed characteristics; a debris flow disaster susceptibility evaluation index system was constructed. Prediction performance of the three models was tested using ROC curves. ICM-RF model had better prediction performance than single models, indicating its superiority for predicting debris flow disaster susceptibility.

GIS-Based assessment of geological hazard susceptibility in Southeastern Tibetan region: An information entropy approach

The terrain and geological conditions in southeastern Tibetan region are complex, especially under the influence of hydraulic and hydroelectric development, and susceptibility to geological hazards has increased. This study focused on three counties in Changdu City. We aimed to assess the susceptibility to geological hazards in this region using Geographic Information System (GIS) technology and information entropy models. Historical geological hazard data from the local area, remote sensing data, and GIS were utilized to develop an information entropy model for landslide geological hazard analysis. Key triggering factors for landslide geological hazards in the southeastern Tibetan region were identified, and a comprehensive dataset was compiled. Information entropy model was applied to consider various influencing factors and calculate their impact on geological hazards, Landslide risk in the area was analyzed and generate a susceptibility map for geological hazards. Our results indicate significant correlations between factors, such as steep terrain, human engineering activities, and land types with landslide occurrences. The established evaluation model can reasonably predict potential geological hazard risk in Nujiang River region and partially reflect the distribution characteristics of geological hazards in the southeastern Tibetan region. This offers a scientific foundation for relevant authorities to formulate disaster prevention and response strategies.

A knowledge-based intelligent recognition method for rock discontinuities with point cloud data

ABSTRACT Rock discontinuity information plays a key role in engineering activities. In severely fragmented and discontinuous samples, the identification accuracy of rock discontinuities can be improved with the help of geologic knowledge with identified spatial features and geoscience interaction mechanisms. Therefore, we proposed a new method – a knowledge-based intelligent recognition method for rock discontinuities that used point cloud data – to correct inaccurate identification by considering the spatial relationships of rock discontinuities. This paper integrated the geologic knowledge bases in rock discontinuity information extraction rules and combined the generative rule inference model with the region growing method for intelligent extraction. In the case study, we developed four typical rule sets as examples based on the constructed rule system to group rock discontinuities and subsume the fractured rock discontinuities. Results show that this new method is effective in identifying and classifying rock discontinuities of complex areas with a greater reduction in manual intervention.

Identity Trajectories of Faculty Members through Interdisciplinary STEAM Collaboration Paired with Public Communication

Faculty members in science, technology, engineering, and mathematics (STEM) fields are accustomed to presenting their research findings through journal publications, conference presentations, textbooks, and other academic mediums. However, the audience for these traditional forms of communication are other researchers, which raises concerns about how science research and knowledge are communicated to audiences who have less expertise on these topics. We sought to understand how faculty members develop their identities through collaborative professional development opportunities aimed at growing communication skills to communicate with audiences less familiar with research through interdisciplinary science, technology, engineering, arts, and mathematics (STEAM) activities. We conducted a qualitative, longitudinal study with sixteen STEAM faculty members to explore their identity trajectories as their interdisciplinary cohorts participated in various collaborations to engage with public audiences about their research. Through our analysis, we found that each faculty member’s dominant identity played a significant role in their identity trajectory through their professional development. We observed a significant growth in faculty members’ communication skills, such as learning new presentation techniques to engage others in their research areas of expertise and in their understanding of interdisciplinary STEAM collaboration. Our results provide insights into the identity trajectories of faculty members and how their identity development through these interdisciplinary STEAM collaborations will impact their formal education roles as researchers and teachers moving forward.

Early Identification and Dynamic Stability Evaluation of High-Locality Landslides in Yezhi Site Area, China by the InSAR Method

In mountainous regions, high-locality landslides have the characteristics of a latent disaster process with a wide disaster range, which can easily cause large casualties. Therefore, early landslide identification and dynamic stability evaluation are significant. We first used multi-temporal synthetic aperture radar data to detect potential landslides at Yezhi Site Area during the 2015–2020 period, identifying and mapping a total of 18 active landslides. The study area was found to have an average deformation rate between −15 and 10 mm/y during the period. Then, time series and spatiotemporal deformation characteristics of landslides were examined using interferogram stacking and small baseline interferometry techniques. The results show that the majority of the landslide deformations detected exhibit a periodic variation trend, and the study area was in a slow deformation state before 2017. Finally, combined with detection results, Google Earth optical images, and field investigations, it is concluded that the main factors affecting the time series deformation and spatial distribution of landslides in the study area are rainfall, geological factors, and engineering activities. The results of this study provide valuable technical references and support for early identification and dynamic stability evaluation of regional active landslides in complex terrain, especially for high-locality landslides.

Stripped-envelope supernova light curves argue for central engine activity.

The luminosity of stripped-envelope supernovae, a common type of stellar explosion, is believed to be mainly driven by the radioactive decay of the nickel synthesized in the explosion and carried in its ejecta. Additional possible energy sources have been previously suggested1-5, in which the two most observationally based results have been from a comparison of the observed time-weighted luminosity with the inferred radioactive power1 and from a comparison of the light curves with particular theoretical models3. However, the former result1 was not statistically significant, and the latter3 is highly dependent on the specific models assumed. Here we analyse the energy budget of a sample of 54 well-observed stripped-envelope supernovae of all sub-types and present statistically significant, largely model-independent, observational evidence for a non-radioactive power source in most of them (and possibly in all). We consider various energy sources, or alternatively, plausible systematic errors, that could drive this result, and conclude that the most likely option is the existence of a long-lived central engine, operating over ≈103-106 s after the explosion. We infer, from the observations, constraints on the engine properties. If, for example, the central engine is a magnetized neutron star, then the initial magnetic field is ≈1015 G and the initial rotation period is 1-100 ms, suggesting that stripped-envelope supernovae may constitute the formation events of the objects known as magnetars.

Effect of salinity on geotechnical properties of soft marine clay

ABSTRACT Marine clays are soft clays with low shear strength and high compressibility. These soils are prone to seawater intrusion, due to which their engineering properties may be altered. Therefore, the effect of salinity on engineering properties of marine clay has to be investigated prior to any engineering activity in those areas. In this paper, an attempt has been made to study the effect of salinity on various geotechnical properties of Cochin marine clay. As sodium chloride is the most abundant mineral salt in seawater, the effect of 0%, 0.5%, 1%, 2%, 3% and 4% sodium chloride on marine clay for different curing periods were studied. The results of the study show that liquid limit decreases whereas the strength and compressibility characteristics improve as the concentration of salinity increases. Leaching, however, reverses these improvements, amplifying compressibility by 30% and decreasing pre-consolidation pressure by almost 50%. ITherefore, prior to design of any foundation structures on coastal areas prone to salt water intrusion, the behaviour of clay with variation in salinity should be investigated.

Identifying concerns when specifying machine learning-enabled systems: A perspective-based approach

Engineering successful machine learning (ML)-enabled systems poses various challenges from both a theoretical and a practical side. Among those challenges are how to effectively address unrealistic expectations of ML capabilities from customers, managers and even other team members, and how to connect business value to engineering and data science activities composed by interdisciplinary teams. In this paper, we present PerSpecML, a perspective-based approach for specifying ML-enabled systems that helps practitioners identify which attributes, including ML and non-ML components, are important to contribute to the overall system’s quality. The approach involves analyzing 60 concerns related to 28 tasks that practitioners typically face in ML projects, grouping them into five perspectives: system objectives, user experience, infrastructure, model, and data. Together, these perspectives serve to mediate the communication between business owners, domain experts, designers, software and ML engineers, and data scientists. The creation of PerSpecML involved a series of formative evaluations conducted in different contexts: (i) in academia, (ii) with industry representatives, and (iii) in two real industrial case studies. As a result of the diverse validations and continuous improvements, PerSpecML stands as a promising approach, poised to positively impact the specification of ML-enabled systems, particularly helping to reveal key components that would have been otherwise missed without using PerSpecML.Editor’s note: Open Science material was validated by the Journal of Systems and Software Open Science Board.

A review on the interactions between engineering and marine life: key information for engineering professionals

AbstractMarine life both affects and is affected by coastal, marine and offshore engineering. As engineering projects have become larger, more frequent and more complex, hence has the number and type of interactions with marine life. Engineers are looking for more information about these interactions so they can better mitigate against any harmful effects to marine life and enhance any positive impacts. This review aims to fill this purpose, giving professional engineers a broad understanding of the impacts that marine engineering projects can cause to marine life and to suggesting some “best practice” mitigation strategies. The review considers the interactions between engineering projects and marine life from three perspectives with a specific example given in each case. First, potential mitigation measures are discussed in the context of offshore windfarms. Secondly, the issue of engineering noise affecting marine species in different ways. Lastly, the engineering solutions employed in the “Great Barrier Reef (GBR) Restoration Project” is exampled. Environmental Impact Assessments used by managers must reference up-to-date and detailed data from biological surveys so that local species that are vulnerable to the specific engineering activities can be identified. The mitigation activities must include acoustic mitigation, be scalable and affordable. This review highlights the need for engineers to liaise closely with marine scientists and biologists to ensure that solutions are appropriate and do not have unexpected or indirect consequences to marine life.

Perlindungan Konsumen dalam Rekayasa Rating Penilaian pada Aplikasi Shopee Perspektif Mazhab Imam Asy-Syafi’i: Studi Kasus Pengguna Aplikasi Shopee di Desa Tembung Kecamatan Percut Sei Tuan

High competition encourages business actors to use various methods to market their products, without paying attention to applicable rules and laws. One of the strategies used is Rating Engineering. Rating engineering is a false assessment that is often used to increase the reputation of a shop so that it is more trustworthy when people visit it when they want to shop with the aim of making buyers interested and concluding that the shop is a shop that is very popular on its site. The existence of rating engineering activities makes consumers worried about the authenticity of the goods being sold. This research discusses legal protection and the perspective of the Imam Syafi'i School regarding rating engineering activities. The aim of this research is to determine the impact of rating engineering using fake orders and consumer protection against the practice of rating engineering. The results obtained are that consumer protection has been very well regulated from a religious perspective, namely the Al-Qur'an and Hadith as well as from a legal perspective in Indonesia in Law No. 8 of 1999, so this is very strong to follow in terms of consumer protection and also obligations. business actors in carrying out their business can create a society that behaves correctly and honestly in every implementation. According to the perspective of the Imam Asy-Shafi'i School, the practice of rating engineering carried out by several online business actors on the Shopee application is haram because it violates buying and selling ethics and business ethics by committing fraudulent acts in their promotions in the marketplace.

Introduction of Activities of Professional Engineers and the Metals, the Institution of Professional Engineers, Japan

Introduction of Activities of Professional Engineers and the Metals, the Institution of Professional Engineers, Japan

РОЛЬ ІННОВАЦІЙНОЇ СКЛАДОВОЇ РОЗВИТКУ ПІДПРИЄМСТВА В УМОВАХ КОНКУРЕНТНОГО СЕРЕДОВИЩА

The most significant source of the emergence and maintenance of competitive advantages of the enterprise is the use of updated scientific and technical products, which are the result of scientific, engineering, technological and intellectual activities of leading specialists. High competitiveness provides opportunities to earn profits sufficient to interest investors for further cooperation, which will ensure stable development of the enterprise. Thus, under the conditions of a dynamic competitive environment, the introduction of innovations is a necessary condition for maintaining high competitive positions of the enterprise. Based on the theory of "innovative development" developed by J. Schumpeter, the main emphasis in the article is on the need to introduce innovations into the production process, as an integral component of ensuring competitiveness on the market of the business entity. Thus, the modern market needs the active development of innovations materialized in updated technologies, products, organizational and management solutions. Innovative activity has several specific features: increased risk, unpredictability of results, delayed effectiveness (longterm nature of obtaining results), and at the same time, the potential for obtaining high profits. The formation of the company's innovative potential, as well as its implementation, is determined, to a greater extent, by the continuous interaction of a complex of factors and conditions that accelerate the innovation process, from the results of scientific research to the introduction of innovative technology, or the mass release of innovative products. The article explores such important categories as "innovation", "novation", "discovery", "invention" and "innovation" and outlines the clear differences between them. Different approaches of scientists to the category "innovative potential" are characterized. The choice of the most optimal method of assessing the innovation potential is of great importance, since such an indicator demonstrates the readiness of the enterprise to create an innovative product in the form of a scientific and technical sample and its use in practice, and also helps to assess how much the implementation of the innovation is economically justified. The methods of assessment of innovation potential proposed by various scientists, which are most widely used in practice, are considered.

Perlindungan Konsumen dalam Rekayasa Rating Penilaian pada Aplikasi Shopee Perspektif Mazhab Imam Asy-Syafi’i: Studi Kasus Pengguna Aplikasi Shopee di Desa Tembung Kecamatan Percut Sei Tuan

High competition encourages business actors to use various methods to market their products, without paying attention to applicable rules and laws. One of the strategies used is Rating Engineering. Rating engineering is a false assessment that is often used to increase the reputation of a shop so that it is more trustworthy when people visit it when they want to shop with the aim of making buyers interested and concluding that the shop is a shop that is very popular on its site. The existence of rating engineering activities makes consumers worried about the authenticity of the goods being sold. This research discusses legal protection and the perspective of the Imam Syafi'i School regarding rating engineering activities. The aim of this research is to determine the impact of rating engineering using fake orders and consumer protection against the practice of rating engineering. The results obtained are that consumer protection has been very well regulated from a religious perspective, namely the Al-Qur'an and Hadith as well as from a legal perspective in Indonesia in Law No. 8 of 1999, so this is very strong to follow in terms of consumer protection and also obligations. business actors in carrying out their business can create a society that behaves correctly and honestly in every implementation. According to the perspective of the Imam Asy-Shafi'i School, the practice of rating engineering carried out by several online business actors on the Shopee application is haram because it violates buying and selling ethics and business ethics by committing fraudulent acts in their promotions in the marketplace.