A Discussion on “Pythagorean fuzzy AHP based risk assessment methodology for hazardous material transportation: an application in Istanbul”

Ayyildiz et al. (Environmental Science and Pollution Research (2021), 1-13) pointed out that it is important to identify and minimize the critical risks in the transportation of hazardous material. For the same, Ayyildiz et al. proposed an effective integrated decision-making methodology by combining the Modified Delphi Method (MDM) and Pythagorean fuzzy analytic hierarchy process (PF-AHP). In this integrated methodology, PF-AHP method is utilized to obtain weights of main and sub-risk factors in order to rank these factors. In Step 5 of PF-AHP method an interval valued Pythagorean fuzzy pairwise comparison matrix is transformed into a crisp matrix and then crisp AHP is applied to obtain the normalized weights from the transformed crisp matrix. It is quite evident that the crisp AHP is used only for crisp pairwise comparison matrix. However, after a deep study, it is observed that the transformed crisp matrix, obtained on applying the steps of Ayyildiz et al. methodology, violates the reciprocal propriety of pairwise comparison matrix. Therefore, to apply crisp AHP on the transformed crisp matrix is mathematically incorrect and will lead to problematic decision-making approach. Hence, may result in a heavy loss in any value-added model such as hazardous material transportation problems. Therefore, the Ayyildiz et al. methodology is not valid in its present form and cannot be used to find the solution of such type of real-life problem. Keeping the same in mind, the focus of this discussion is to make the researchers aware about these mathematical incorrect assumptions and the necessary modification is suggested.

Comparison of spreadsheet-based optimization tools applied to construction site layout problem

This paper compares different spreadsheet-based optimization tools applied to a practical example of a construction site layout problem. The objective of the optimization is to minimize the total time of material transportation by optimal positioning of tower crane and work facilities on the construction site with repetitive operations. Computer programs, such as MS Excel, LibreOffice Calc, and Google Sheets can be applied as modeling tools for a variety of construction optimization problems in addition to their usual functionalities. In this study, LibreOffice Calc Solver, MS Excel Solver, along with other MS Excel add-ins, i.e., OpenSolver, Evolver, and What’sBest, are analyzed. The capabilities of optimization tools mentioned above are examined on the problem of optimal positioning of tower crane and work facilities on the construction site. The results obtained by optimization tools are noted and discussed. The paper ends with conclusions and recommendations for further research.

Concrete vs. Ceramic Blocks: Environmental Impact Evaluation Considering a Country-Level Approach

In continental countries, building materials are often moved over long distances from factories to building sites. This is especially important when quality and performance certification systems are required for the building materials’ acquisition. In this scenario, the transportation phase tends to have a great contribution to building materials’ environmental impacts. Taking into consideration that countries such as China, India, and Brazil, i.e., continental countries, are expecting the largest future housing demand, the issue of transportation will have a crucial role in environmental impacts. Through a Brazilian case study, the present work investigates the potential environmental impacts of structural masonry made of concrete and ceramic blocks certified by the Brazilian Quality Program. A cradle-to-site Life-Cycle Assessment (LCA) is carried out while considering a country-level approach using data from the literature and Ecoinvent. The results show that ceramic blocks are preferable for most states and scenarios. Human Health and Ecosystem Quality are the two categories most affected by transportation, and they can reach more than 96% and 99%, respectively. The efficiency of the building material transportation system plays an important role in reducing greenhouse gas emissions. A shift in building components from concrete to ceramic blocks has the potential to mitigate between 154 and 229 Mt CO2-eq between 2020 and 2050. The methodological approach used in this work can be applied to other building materials and other countries, especially those of continental dimensions that are expected to have a significant future housing demand.

Genomic and Transcriptomic Analysis of Bovine Pasteurella multocida Serogroup A Strain Reveals Insights Into Virulence Attenuation

Pasteurella multocida is one of the primary pathogens of bovine respiratory disease (BRD), and causes huge losses in the cattle industry. The Pm3 strain was a natural isolate, which is a strong form of pathogen and is sensitive to fluoroquinolones antibiotics. A high fluoroquinolone resistant strain, Pm64 (MIC = 64 μg/mL), was formed after continuous induction with subinhibitory concentration (1/2 MIC) of enrofloxacin, with the enhanced growth characteristics and large attenuation of pathogenicity in mice. This study reports the whole genome sequence and the transcription profile by RNA-Seq of strain Pm3/Pm64. The results showed an ineffective difference between the two strains at the genome level. However, 32 genes could be recognized in the gene islands (GIs) of Pm64, in which 24 genes were added and 8 genes were lost. Those genes are involved in DNA binding, trehalose metabolism, material transportation, capsule synthesis, prophage, amino acid metabolism, and other functions. In Pm3 strain, 558 up-regulated and 568 down-regulated genes were found compared to Pm64 strain, from which 20 virulence factor-related differentially expressed genes (DEGs) were screened. Mainly differentially transcribed genes were associated with capsular polysaccharide (CPS), lipopolysaccharide (LPS), lipooligosaccharide (LOS). Iron utilization, and biofilm composition. We speculated that the main mechanism of virulence attenuation after the formation of resistance of Pm64 comes from the change of the expression profile of these genes. This report elucidated the toxicity targets of P. multocida serogroup A which provide fundamental information toward the understanding of the pathogenic mechanism and to decreasing antimicrobial drugs resistance.

Evaluation of tanker vehicle selection using a novel hybrid fuzzy MCDM technique

Petroleum product transportation considered as one of the crucial parts of dangerous material transportation is a risky logistics activity. The selection of the appropriate tanker vehicles may be a suitable solution to reduce the risks and increase the efficiency and performance of the fuel transportation companies. However, the selection of a suitable road tanker vehicle is not an easy task for decision-makers as there are many conflicting criteria and many decision alternatives. In addition, decision-makers may have to decide with insufficient information since collecting crisp values may not be possible at all times. Hence, many ambiguities affecting the evaluation results exist in an assessment process performed to select the best tanker vehicle option. This paper suggests a novel integrated fuzzy approach to solve these decision-making problems. Sensitivity analysis is conducted to test the validation of the proposed integrated fuzzy approach and its results was performed by forming 130 scenarios. The results of sensitivity analysis prove that the proposed model can be applied to solve these kinds of decision-making problems.

Discrete Simulations in Analyzing the Effectiveness of Raw Materials Transportation during Extraction of Low-Quality Deposits

The article presents an analysis of the influence of selected operating environment parameters on the operation of a technological system in a mine and examines the profitability of exploiting a deposit of low quality. A model based on a cyclical transportation system in a surface limestone mine, developed in the Haulsim software, served to evaluate—from an economic perspective—several material transportation scenarios depending on the quality of the deposit. A discrete simulation of machine operation allowed a detailed analysis of the technological, operating and economic parameters for selected solutions. The results may be the basis for a decision to begin or to resign from mineral extraction. The simulation results demonstrate that maintaining the operating environment in good technical condition positively influences machine operating cycle times, the required total time of the transportation task and the operating costs. The analysis was performed for the production period of one full year, allowing for the effective work and technological downtimes. This approach allowed the usefulness of the model to be demonstrated in evaluating not only the effectiveness of individual technological procedures but also its economic aspect, related to a decision on the exploitation of “difficult” deposits.

Environmental and Economic Life Cycle Assessment of Recycled Aggregates Concrete in the United Arab Emirates

This paper studies the potential environmental and economic impact of replacing natural aggregates (NA) with recycled aggregates (RA) in the production of different sustainable concrete mixes in the United Arab Emirates (UAE). A life cycle assessment (LCA) was carried out according to the methodology proposed by the international standards of the series ISO 14040. The performance of concrete mixes having a similar design compressive strength was evaluated. Results showed that the inclusion of steel fibers (SF) led to an increase in the global warming potential (GWP), whereas mixes with cement replacement by fly ash, slag, or microsilica recorded a reduction in GWP. Furthermore, SF-reinforced mixes created with 100% RA were at least three times more expensive than the NA-based control mix, while the cost of those with cement replacement by mineral additives was generally similar to that of the control. Material transportation was found to be a main contributor to the environmental and economic impacts, only second to cement, and its contribution increased with longer distances and steel fiber incorporation and decreased with RA replacement. To integrate these individual measures and select optimum mixes for various applications, multifunctional performance indices were developed. Research findings highlight the possibility to fully replace NA with RA (100%) while maintaining the performance and improving the economic and environmental impacts of concrete produced in the UAE.