Hasil untuk "Engineering economy"

J. Andersson, Stefan Grönkvist

Abstract The large-scale storage of hydrogen plays a fundamental role in a potential future hydrogen economy. Although the storage of gaseous hydrogen in salt caverns already is used on a full industrial scale, the approach is not applicable in all regions due to varying geological conditions. Therefore, other storage methods are necessary. In this article, options for the large-scale storage of hydrogen are reviewed and compared based on fundamental thermodynamic and engineering aspects. The application of certain storage technologies, such as liquid hydrogen, methanol, ammonia, and dibenzyltoluene, is found to be advantageous in terms of storage density, cost of storage, and safety. The variable costs for these high-density storage technologies are largely associated with a high electricity demand for the storage process or with a high heat demand for the hydrogen release process. If hydrogen is produced via electrolysis and stored during times of low electricity prices in an industrial setting, these variable costs may be tolerable.

Yu Zheng, L. Capra, O. Wolfson et al.

Derui Ding, Q. Han, Yang Xiang et al.

David N. Beede, Tiffany Julian, D. Langdon et al.

Chan-Chiao Lin, Huei Peng, J. Grizzle et al.

Sandra E. Black, Lisa M. Lynch

YANG Xiangke, DUAN Changlin, LIU Di, NING Yuchang, PAN Chunmei

In order to investigate the effect of Lactiplantibacillus plantarum XJ25 citrate transporter deficient strain XJ25-ΔcitP on the flavor of wine malolactic fermentation (MLF). The deficient strain XJ25-ΔcitP was added into the malolactic fermentation process of wine, and the changes in the flavor characteristics of wine were comprehensively revealed by measuring the total acid, volatile acid, key organic acid contents, volatile flavor components and sensory evaluation, and combining with multivariate statistical methods. The results showed that deficient strain XJ25-ΔcitP could complete malolactic fermentation without relying on the citric acid metabolism pathway. Compared with the wine fermented by wild strain XJ25, the total acid content of the wine fermented by deficient strain XJ25-ΔcitP significantly increased by 5.14% (P<0.05), while the contents of volatile acid, acetic acid, lactic acid and succinic acid significantly decreased by 37.80%, 41.65%, 3.94% and 8.97%, respectively (P<0.05). The citric acid in the fermented sample by wild strain XJ25 was completely metabolized and not detected, while the fermented wine sample by deficient strain XJ25-ΔcitP retained 81.56% of the citric acid. A total of 118 volatile flavor components were detected in the 3 groups of wine samples. There were significant differences in volatile flavor components among different wine samples. According to the variable importance in projection (VIP) value>1 and P<0.05, a total of 53 differential volatile flavor components were screened out. Inoculation with the deficient strain XJ25-ΔcitP for malolactic fermentation not only reduced the raw green flavor of the original wine, but also enhanced the fruity, floral and roasted aromas. Moreover, it avoided the overly creamy and pungent taste of the wild strain XJ25 after fermentation. This research provided a new strain improvement strategy for targeted regulation of wine quality.

Ertan Yildirim, Melek Ekinci, Metin Turan et al.

This study examined how different water restriction levels (T100%, T85%, T75%, and T55%) influence the nutritional and bioactive compounds of Bahar and Dadaş cress (<i>Lepidium sativum</i> L.) cultivars. The highest levels of phenolic compounds found in Dadaş and Bahar cress were quercetin (8.33 ± 0.23–9.32 ± 0.25 µg/L), ferulic acid (8.08 ± 0.18–8.42 ± 0.19 µg/L), catechin (6.83 ± 0.28 µg/L), and caftaric acid (5.40 ± 0.45 µg/L). Mild and moderate drought treatments (85% and 75% humidity) caused notable increases in phenolic compounds. The highest antioxidant enzyme levels were observed as GST, 6GPD, and G6PD in Bahar and Dadaş cress, with enzyme levels rising under drought conditions. Notably, the mild drought treatment roughly doubled peonidin-3-glucoside acetyl levels in the cress cultivars. Sugar contents of Dadaş and Bahar cress cultivars also rose significantly with drought treatment. Riboflavin, the most abundant vitamin in cress cultivars, increased to 40.96 ± 1.24 mg/kg in Dadaş and 30.79 ± 1.60 mg/kg in Bahar cress under drought stress. Amino acids showed the highest increases under severe drought, with asparagine rising by roughly 2.76-fold and leucine increasing by 2.67-fold in Bahar cress. These findings suggest that controlled water restriction can enhance the nutritional and bioactive properties of cress, potentially leading to more nutrient-rich products for the food industry and human health.

Hamed Zeinoddini-Meymand, Reza Safipour, Farhad Namdari

The optimal operation of a hybrid AC-DC microgrid is investigated in this study. The operation of an AC microgrid connected to the main grid and an islanded DC microgrid has been examined under three management approaches. In the first approach, two microgrids are not connected, and the DC microgrid is operated in the islanded mode. In the second and third approaches, AC and DC microgrids are connected. The main difference between these two approaches is the energy management framework. In the second approach, each microgrid has its own management system, while the third approach integrates both into a single energy management system to form an AC-DC microgrid that minimizes overall operational costs. The main goal of the proposed model is to minimize the operating costs of two microgrids over a 24 h period. The investigated AC microgrid includes a microturbine, wind turbine and diesel generator in order to supply the residential load profile, and the DC microgrid includes an energy storage system, fuel cell, wind turbine and solar panel in order to supply the commercial load profile. Simulations are performed first with a wind and load scenario in order to show and compare the optimal points of using the decision variables in three approaches. Finally, in order to prove the effectiveness of the proposed method in the presence of uncertainties, the cost distribution function for the three approaches is presented by means of Monte Carlo simulation. Applying the proposed model results in the following the cost reduction: 67.9% in the DC microgrid, 14.2% in the AC microgrid and 24.4% overall. This reduction is primarily attributed to the microgrid central energy management system, which decreases reliance on the main grid and instead utilizes alternative sources such as fuel cells. Comparing the first and third approaches, the fuel cell’s contribution to supplying microgrid loads increased by 29%, while the main grid’s participation decreased by 26%.

Yoyo Sudaryo, Deni Hamdani, Nunung Ayu Sofiati et al.

This study's objectives are to ascertain the impact of variables that determine financial distress among Small and Medium-sized Enterprises (SMEs) during the COVID-19 pandemic and post-pandemic period, including the perception of SMS offenders, knowledge of digital marketing, and growth in net profits, as well as to offer solutions to the issues that SMEs face. In Cirebon a descriptive and verifying strategy is taken in the employment of quantitative methodologies in the research. Primary data were used. Gathering information from fieldwork and library research based on surveys distributed and previously published works on SMS's Rattan crimes registered with Cirebon's Micro & Medium Enterprises Cooperation Service. Verification statistics analysis procedures include the use of hypothetical testing with partial and simultaneous tests (f and t-test) as well as data analysis testing using double linear regression. One hundred respondents from SME victim Rattan Cirebon provided the sample data. IBM SPSS version 21.0 is the analytical program that was utilized to process the data. According to some of the research findings, financial distress is greatly impacted by the impression of SME offenders, is unaffected by knowledge of digital marketing, and is greatly impacted by an increase in net profit. Simultaneous research findings reveal that the perspective of SME offenders, comprehension of digital marketing, and growth in net profit have a noteworthy impact on financial Distress.

Jay Lee, Hanqi Su, Dai-Yan Ji et al.

Over the past ten years, the application of artificial intelligence (AI) and machine learning (ML) in engineering domains has gained significant popularity, showcasing their potential in data-driven contexts. However, the complexity and diversity of engineering problems often require the development of domain-specific AI approaches, which are frequently hindered by a lack of systematic methodologies, scalability, and robustness during the development process. To address this gap, this paper introduces the "ABCDE" as the key elements of Engineering AI and proposes a unified, systematic engineering AI ecosystem framework, including eight essential layers, along with attributes, goals, and applications, to guide the development and deployment of AI solutions for specific engineering needs. Additionally, key challenges are examined, and eight future research directions are highlighted. By providing a comprehensive perspective, this paper aims to advance the strategic implementation of AI, fostering the development of next-generation engineering AI solutions.

Anatoly A. Krasnovsky

Chaos engineering reveals resilience risks but is expensive and operationally risky to run broadly and often. Model-based analyses can estimate dependability, yet in practice they are tricky to build and keep current because models are typically handcrafted. We claim that a simple connectivity-only topological model - just the service-dependency graph plus replica counts - can provide fast, low-risk availability estimates under fail-stop faults. To make this claim practical without hand-built models, we introduce model discovery: an automated step that can run in CI/CD or as an observability-platform capability, synthesizing an explicit, analyzable model from artifacts teams already have (e.g., distributed traces, service-mesh telemetry, configs/manifests) - providing an accessible gateway for teams to begin resilience testing. As a proof by instance on the DeathStarBench Social Network, we extract the dependency graph from Jaeger and estimate availability across two deployment modes and five failure rates. The discovered model closely tracks live fault-injection results; with replication, median error at mid-range failure rates is near zero, while no-replication shows signed biases consistent with excluded mechanisms. These results create two opportunities: first, to triage and reduce the scope of expensive chaos experiments in advance, and second, to generate real-time signals on the system's resilience posture as its topology evolves, preserving live validation for the most critical or ambiguous scenarios.

Georgi Markov, Jon G. Hall, Lucia Rapanotti

Many organisational problems are addressed through systemic change and re-engineering of existing Information Systems rather than radical new design. In the face of widespread IT project failure, devising effective ways to tackle this type of change remains an open challenge. This work discusses the motivation, theoretical foundation, characteristics and evaluation of a novel framework - referred to as POE-$Δ$, which is rooted in design and engineering and is aimed at providing systematic support for representing, structuring and exploring change problems of a socio-technical nature, including implementing their solutions when they exist. We generalise an existing framework of greenfield design as problem solving for application to change problems. From a theoretical perspective,POE-$Δ$ is a strict extension to its parent framework, allowing the seamless integration of greenfield and brownfield design to tackle change problems. A Design Science Research methodology was applied over a decade to define and evaluate POE-$Δ$, with significant case study research conducted to evaluate the framework in its application to real-world change problems of varying criticality and complexity. The results show that POE-$Δ$ exhibits desirable characteristics of a design approach to organisational change and can bring tangible benefits when applied in practice as a holistic and systematic approach to change in socio-technical contexts.

Pertti Lahdenperä

Design–build (DB) is a much used project delivery system with operational variations for different needs and situations. Yet, novel applications have to be strived for as all of the current applications have some drawbacks. Accordingly, this study focuses on a DB procedure that exploits the parties’ collaboration in order to improve the economic efficiency of construction projects. It is called “design–build with a development phase” (DBd). In the procedure, the owner and the selected contractor continue the development of the project solution in co-operation, adhering to the principle of benefit sharing, which is enabled by the benchmark solution, formed as a result of price-inclusive contractor selection. More precisely, this paper presents the DBd procedure and how it was initially constructed and eventually applied in a few infrastructure projects. The paper also reports the related experiences, which were positive based on the improved value for money in the trial projects. Thus, the paper contributes by disproving the dominant view, which has been guiding the formulation and use of the current project delivery practices, that price-inclusive competition and collaborative development thereafter could not be matched successfully.

Barbara Bong, Chalachew Mebrahtu, Daniela Jurado et al.

Ivan Bodniia, Ivan Kerezvas, Vasyl Syvochka

Integration processes in science, education and production are driven by the acceleration of scientific and technological progress, the introduction of innovative scientific developments into mass production and the informatisation of the economy. The development of knowledge-intensive industries places new demands on the training and retraining of innovation-sensitive personnel, as well as on science, education and the economy as a whole, which are currently unable to develop effectively independently and adapt to changes in technology and engineering. The purpose of the article is to find promising areas for the development of education and science based on their integration with business entities not only within the limited space of regions, but also on the basis of spatial integration of territories with a special geographical location. Methodology. The necessary and socially significant conditions for the integration of science, education and business are the achievement of knowledge and skills, goals and values related to the acceleration of the reproduction of innovation potential in society, awareness of the role of science, education and business in solving problems of innovation development, and also their integration interaction in this area. Practical implications. Three main levels of economic systems are allocated: individual, organisation, and region. It has been determined that the degree of influence of innovation processes on them is determined by the presence and condition of three factors necessary for the formation of innovation susceptibility (stabilising, activating and structural). Value/Оriginality. Based on the concepts of the main innovation systems and the necessary conditions for innovative economic growth, the authors have clarified the content of the category "innovation receptivity of the region". The paper also reveals the basic principles of building a model of innovation receptivity and determines the degree of interdependence and interdependence between its constituent elements based on a systematic approach.

Mona Ghaslani, Reza Rezaee, Omid Aboubakri et al.

Hydrothermal carbonization (HTC) solid and liquid products may inhibit seed germination, necessitating post-treatment. The hydrothermal humification (HTH) method addresses this drawback by transforming inhibitory compounds, such as aromatics, into artificial humic acids (AHAs) and artificial fulvic acids (AFAs). This study introduces a novel approach by investigating the substitution of the commonly used alkaline agent in HTH, KOH, with hydrated lime to develop cost-effective hydrothermal fertilizers from sugar beet pulp, enriching them with AHAs. It assesses the effects of lime on AHA production and soluble organic compounds compared to KOH. The results indicate that lime significantly reduces furans (from 560 to 3.15 mg/kg DM in solid and from 344 to 3.86 mg/L in process liquid) and boosts sugars and organic acids, especially lactic acid (from 4.70 to 65.82 g/kg DM in solid and from 4.05 to 22.89 mg/L in process liquid), increasing hydrochar yield (68.8% with lime vs. 27.4% with KOH). Despite the lower AHA production with lime compared to KOH (3.47% vs. 15.50%), lime-treated hydrothermal products are abundant in calcium and magnesium, boasting a pH of 7. This property presents a safer and more efficient alternative to hydrothermal fertilizers. The characterization of AHAs aligns with standard and natural humic substances, while lime-assisted HTH products, applied at a level of 0.01% w/w, could significantly enhance wheat growth and nutrient uptake compared to the control group. Importantly, these products show no toxicity on Daphnia magna, underscoring their potential for sustainable agriculture.

Gumbatov M. O., Sadigov R. A., Huseynov M. A. et al.

A study was conducted to study the possibility of intensifying the process of phosphorus-containing fertilizer, in particular superphosphate, using industrial waste. Based on retrospective analyzes of literature data on known methods for producing phosphorus-containing fertilizers, experimental studies were carried out using silicon-containing gel, danburite mineral , and organic acids. Based on theoretical and experimental data, the conditions and parameters that allow the intensification of this process are determined.

Oryza Wisesa, Andi Andriansyah, Osamah Khalaf

Sales prediction analysis requires intelligent data mining techniques with accurate prediction models and high reliability. In most cases, business highly relies on information as well as demand forecast of the sales trends. This research uses B2B sales data for analysis. The B2B data could provide information on how telecommunication company should manage its sales team, products, and budgeting flows. The accurate estimates enable Telecommunication company to survive the market war and increase with market growth. Comprehensible predictive models were studied and analyzed using a technique of machine learning to improve the prediction of the future sale. It is hard to cope with big data and sale prediction accuracy if the system of traditional forecast is used. In this study, machine learning technique was also used to analyze the reliability of B2B sales. In addition, at the end of this research, other measures and techniques used to predict sales were introduced. The predictive model with best performance evaluation is recommended to forecast the trending B2B sales. The study results are put into an order of reliability and accuracy of the best method to predict and forecast including estimation, evaluation, and transformation. The best performance model found was Gradient Boost Algorithm. The result form graph the data close together from beginning till end of data target MSE and MAPE result are the best result than other method, MSE =24.743.000.000,00 and MAPE =0,18. This model performed maximum accuracy in predicting and forecasting of the future B2B sales.

Taikun Li, Hong Wang, Yonghui Lin

Abstract Malaysia's excessive energy consumption has led to the depletion of traditional energy reserves such as oil and natural gas. Although Malaysia has implemented multiple policies to achieve sustainable national energy development, the current results are unsatisfactory. As of 2022, only 2% of the country's electricity supply comes from renewable energy, which accounts for less than 30% of the energy structure. Malaysia must ensure energy security and diversified energy supply while ensuring sustainable energy development. This article uses the fuzzy multi-criteria decision-making(MCDM) method based on cumulative prospect theory to help decision-makers choose the most suitable renewable energy for sustainable development in Malaysia from four dimensions of technology, economy, society, and environment. The results show that solar power is the most suitable renewable energy for sustainable development, followed by biomass, wind, and hydropower, but the optimal alternative is sensitive to the prospect parameters. Finally, it was analyzed that efficiency, payback period, employment creation, and carbon dioxide (CO2) emissions are the most critical factors affecting the development of renewable energy in Malaysia under the four dimensions. Reasonable suggestions are proposed from policy review, green finance, public awareness, engineering education, and future energy. This research provides insightful information that can help Malaysian decision-makers scientifically formulate Sustainable development paths for renewable energy, analyze the problems encountered in the current stage of renewable energy development, and provide recommendations for Malaysia's future renewable energy transition and sustainable development.