The iron and steel industry accounts for about 20% of the annual industrial energy utilization. The intensive fossil fuel consumption in steel industry is associated with CO2 emission. In the absence ...of economically feasible and efficient methods for capture and storage of enormous quantities of CO2 emissions from steel industry, the use of biomass products as a source of energy and reducing agents provides a promising alternative solution for green steel production. However, the biomass application in iron and steel industry is still limited and it suffers strong competition from fossil fuels. The challenges of biomass usage in steel industry are included technical and economic aspects which required synergy between steelmaking and bioenergy sectors. Although intensive work has been carried out separately, there is a lack of link between these two vital sectors. The present article provides a comprehensive review of recent research progresses which have been conducted on biomass upgrading and analysing the opportunities and obstacles for biomass implementation in iron and steel industry. In the first part, an overview on the energy consumption and CO2 emissions in different iron and steelmaking routes is clarified. Moreover, the potential approaches of biomass conversion processes and upgrading technologies are reviewed. In the second part, an attention has been paid to the utilization of torrefied/pyrolyzed biomass in the energy-intensive ironmaking processes. Biomass addition to coal blend during cokemaking and its influence on the product coke quality is discussed. The partial and complete substitution of coke breeze with biochar in sintering process and its influence on the product sinter quality is explained. The impact of charcoal top charging or injection into blast furnace has been elaborated. Benefits and limitations of biomass application in each process are thoroughly discussed. In the third part, an economic analysis of biomass implementation for low-carbon steel is addressed.
This study presents a literature review, especially in recent years, on the absorption refrigeration systems (ARSs), the currently used refrigerant–absorbent pairs and their alternatives. ...Additionally, in this study, the thermodynamic analysis of ARS using commonly encountered solution pairs in the literature was carried out, and a user-friendly software package including visual components was developed. The effects of operating temperatures, the effectivenesses of solution, refrigerant and solution–refrigerant heat exchangers (SHE, RHE, SRHE), and selection of working fluid pair on the system performance were examined by using the developed package. It was concluded that performances of the cycles improve with increasing generator and evaporator temperatures, but reduce with increasing condenser and absorber temperatures. The performance of system was affected from the SHE more than the RHE and SRHE. While the use of SHE improves the system COP up to 66%, RHE and SRHE have an effect of only 14% and 6%, respectively. For that reason, the SRHE may not be considered practically significant. Suitable solutions depending on operating conditions showed variations with respect to generator and evaporator temperatures.
The case analysis is a common assignment in business courses that requires students to use their disciplinary knowledge to identify a company's problems and propose logical recommendations to solve ...them (Gardner, 2012; Nathan, 2013). When writing the recommendations section of a case analysis, students are often required to discuss alternatives to their preferred recommendation as part of their argument for it. Despite the central importance of the recommendations section in case analysis writing, there is limited research on how to effectively help students write it. In this paper, we use SFL-based genre analysis to analyze how effectively students incorporated and rejected alternatives in a case proposal assignment in an Organizational Behavior (OB) course at an American university's branch campus in the Middle East. Unlike other research that focuses only on exemplar or successful student writing (e.g., Nathan, 2016; Nesi & Gardner, 2012; Szenes, 2017, 2021), we show a range of representative text patterns, from students who neglected to take a position on a preferred recommendation, to students who effectively supported a clear position. Our analysis has implications for a range of genres where students need to maintain a consistent stance while arguing for a preferred solution among alternatives.
•We use SFL to identify the genre of giving recommendations in a case proposal.•We analyze how effectively students incorporated alternatives in writing recommendations.•Unlike other research, we show a range of more or less effective text patterns.•We discuss ways to help students to argue while considering alternatives.
•A nonuniform Y-shaped fin is designed to improve the melting phase change.•Compared with original fin tube, complete melting time for Y-shaped tube is reduced by 21.5%.•The bottom melting time for ...all the cases take more than 50% of the total melting time.•Melting rate and temperature uniformity in PCM are improved by lower fin enhancement.
This study provides an alternative solution to the improvement on solid–liquid phase change by designing a Y-shaped fin in a nonuniform pattern along the gravity direction. A numerical model is established and validated through the present measurement and data in literature. Six cases with different Y-shaped fins and locations are designed and compared to the original straight fin case. Thermal assessments on the melting fraction, temperature field, velocity distribution, and uniformity for melting are made. Results demonstrate that the nonuniform melting features caused by the local natural convection are significantly eliminated by the novel nonuniform fin structure. The time required for melting the lower PCM is found to occupy more than 50% of the completely melting time. The accurate local heat transfer enhancement measures (bottom enhancement) are conducive to markedly reduce the full melting time by 21.5%, compared to the uniform fin pattern. Upon using finned thermal storage tank for a mobilized thermal storage truck (bare tube tank), the initial investment increases by 44.9% but the profit increases by 393.6% and the payback period reduces by 69.2%. The use of fin tube in heat storage tank can quickly obtain higher returns based on a small increase in initial investment. This work provides new insights into the understandings of the transient phase change process and the strategies for guiding the design for thermal energy storage tank.
A composite likelihood ratio test implemented in the program sweepfinder is a commonly used method for scanning a genome for recent selective sweeps. sweepfinder uses information on the spatial ...pattern (along the chromosome) of the site frequency spectrum around the selected locus. To avoid confounding effects of background selection and variation in the mutation process along the genome, the method is typically applied only to sites that are variable within species. However, the power to detect and localize selective sweeps can be greatly improved if invariable sites are also included in the analysis. In the spirit of a Hudson–Kreitman–Aguadé test, we suggest adding fixed differences relative to an out‐group to account for variation in mutation rate, thereby facilitating more robust and powerful analyses. We also develop a method for including background selection, modelled as a local reduction in the effective population size. Using simulations, we show that these advances lead to a gain in power while maintaining robustness to mutation rate variation. Furthermore, the new method also provides more precise localization of the causative mutation than methods using the spatial pattern of segregating sites alone.
Heparan sulfate (HS) is a cell surface polysaccharide recently identified as a coreceptor with the ACE2 protein for the S1 spike protein on SARS-CoV-2 virus, providing a tractable new therapeutic ...target. Clinically used heparins demonstrate an inhibitory activity but have an anticoagulant activity and are supply-limited, necessitating alternative solutions. Here, we show that synthetic HS mimetic pixatimod (PG545), a cancer drug candidate, binds and destabilizes the SARS-CoV-2 spike protein receptor binding domain and directly inhibits its binding to ACE2, consistent with molecular modeling identification of multiple molecular contacts and overlapping pixatimod and ACE2 binding sites. Assays with multiple clinical isolates of SARS-CoV-2 virus show that pixatimod potently inhibits the infection of monkey Vero E6 cells and physiologically relevant human bronchial epithelial cells at safe therapeutic concentrations. Pixatimod also retained broad potency against variants of concern (VOC) including B.1.1.7 (Alpha), B.1.351 (Beta), B.1.617.2 (Delta), and B.1.1.529 (Omicron). Furthermore, in a K18-hACE2 mouse model, pixatimod significantly reduced SARS-CoV-2 viral titers in the upper respiratory tract and virus-induced weight loss. This demonstration of potent anti-SARS-CoV-2 activity tolerant to emerging mutations establishes proof-of-concept for targeting the HS–Spike protein–ACE2 axis with synthetic HS mimetics and provides a strong rationale for clinical investigation of pixatimod as a potential multimodal therapeutic for COVID-19.
We have investigated whether there is adaptive evolution in mitochondrial DNA, using an extensive data set containing over 500 animal species from a wide range of taxonomic groups. We apply a variety ...of McDonald–Kreitman style methods to the data. We find that the evolution of mitochondrial DNA is dominated by slightly deleterious mutations, a finding which is supported by a number of previous studies. However, when we control for the presence of deleterious mutations using a new method, we find that mitochondria undergo a significant amount of adaptive evolution, with an estimated 26% (95% confidence intervals: 5.7–45%) of nonsynonymous substitutions fixed by adaptive evolution. We further find some weak evidence that the rate of adaptive evolution is correlated to synonymous diversity. We interpret this as evidence that at least some adaptive evolution is limited by the supply of mutations.
This study presents an overview of data science, exploring the role of data scientists and the methods they employ to investigate analytical problems within business administration. It discusses the ...responsibilities of data scientists, emphasizing their multidisciplinary nature and the importance of technical skills, domain knowledge, and effective communication. The paper outlines commonly utilized methods by data scientists, drawing from computer science, statistics, and operations research. It illustrates the practical application of these methods in addressing analytical problems, including descriptive analytics, predictive analytics, and prescriptive analytics. The paper also highlights potential pitfalls and challenges encountered in the analytic process, such as problem formulation errors and results interpretation.
•Explore data science, unraveling the pivotal role of data scientists in solving business problems.•Shed light on the tasks and responsibilities of data scientists in business administration.•Provide multidisciplinary insights into data science methods and their real-world applications.•Present descriptive, predictive, and prescriptive analytics problems and models.•Review data science opportunities, challenges, and emerging trends in business administration.
This study examines the winner determination problem (WDP) for the procurement of transportation service. The problem contains three important roles, namely, shippers, carriers, and third-party ...carriers. Shippers determine the service lanes that can be outsourced to carriers so that the transportation service cost may be reduced. The WDP can be formulated as a mixed integer linear programming (MILP) model. However, when solving a general MILP model, it is easy to fall into the imbalanced issue of branch-and-bound trees, such that the computational time becomes longer. This study proposes a deterministic model with a powerful and significant theoretical mechanism to conquer the imbalanced issue. Solving the proposed model can minimize the service costs subject to each lane being served by carriers and consider the quantity discount. The most important objective in this study is to identify an iterative algorithm that embeds the proposed model, which presents all alternative solutions for shippers to consider better options. Numerical experiment is also presented to confirm the usefulness of the proposed method.
•An efficient formulation model is proposed.•The quantity-discount procurement in the auction is considered.•Optimal solution is obtained.•Identifying all alternative optimal solutions for the shipper to consider better options.•The proposed method with powerful theorem is also applicable to the expert and intelligent system.
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