Determining the best practicable control technology and its associated emission levels for Iron and Steel industry in Iran

Industrial effluent limitations should be established regarding the special characteristics of each sector with emphasis given to the local context, whereas, in Iran, a uniform “Wastewater Effluent Standard” is employed throughout the country in which no specific industrial effluent limitations have been considered. This gap highlights the essential need for a transparent and scientifically proven methodology for determining effluent emission limit values (ELVs) at the sector level. In this research, an integrated approach is proposed based on the application of the Best Practicable Control Technology Currently Available (BPT) concept. The modelling framework includes a series of sequential steps comprising two main sections: 1. identifying the effluent emission datasets, and 2. computing the emission levels associated with the BPT (BPT-AELs). To identify the datasets, the methodology follows two different procedures: 1. a detailed analysis of the environmental performance of this sector in the country to determine the plants reflecting BPT, and 2. screening their emission datasets through statistical analysis. The Best Available Techniques (BAT) principle is employed as a reference element for determining the best representative plants, and the results indicate that corrective measures in accordance with the BAT considerations should be implemented in many of the plants under consideration. The comparison of the derived BPT-AELs with the existing standards show that they are mainly lower than the standard levels and are reasonable estimations for the involved parameters. Conclusively, this methodology presents a reliable and practical stepwise process at the sector level, which can be developed for other industries

Enhancement of in vitro production of volatile organic compounds by shoot differentiation in Artemisia spicigera

Callus initiation, shoot formation and plant regeneration were established for Artemisia spicigera, a traditional medicinal plant growing in Armenia, Middle-Anatolia and Iran, and pro- ducing valuable volatile organic compounds (VOCs) that are mostly represented by monoterpe- noids. Optimal callus initiation and shoot production were obtained by culture of hypocotyl and cotyledon explants on MS medium comprising 0.5 mg L−1 naphthalene acetic acid (NAA) and 0.5 mg L−1 6-benzyladenine (BA). Consequently, the shoots were transferred onto the MS media sup- plemented with 1 mg L−1 of indole-3-butyric acid (IBA) or 1 mg L−1 of NAA. Both types of auxin induced root formation on the shoots and the resulting plantlets were successfully grown in pots. The production of VOCs in callus tissues and regenerated plantlets was studied by gas chroma- tography–mass spectrometry (GC-MS) analysis. Although the potential of undifferentiated callus to produce VOCs was very low, an increased content of bioactive volatile components was ob- served at the beginning of shoot primordia differentiation. Intriguingly, the volatiles obtained from in vitro plantlets showed quantitative and qualitative variation depending on the type of auxins used for the rooting process. The acquired quantities based on total ion current (TIC) showed that the regenerated plantlets using 1 mg L−1 NAA produced higher amounts of oxygenated monoter- penes such as camphor (30.29%), cis-thujone (7.07%), and 1,8-cineole (6.71%) and sesquiterpene derivatives, namely germacrene D (8.75%), bicyclogermacrene (4.0%) and spathulenol (1.49%) compared with the intact plant. According to these findings, in vitro generation of volatile organic compounds in A. spicigera depends on the developmental stages of tissues and may enhance with the formation of shoot primordia and regeneration of plantlets

Reducing temperature, drag load and wear during aircraft tyre spin-up

Purpose Due to the static condition of the wheels at touchdown, they skid on the runway, which may cause the tyres to burn and wear. This phenomenon occurs in a fraction of a second, known as the spin-up period. The purpose of this paper is to introduce a new strategy to reduce the horizontal force, tyre temperature and wear during the spin-up period. Design/methodology/approach First, the dynamics of two different phases of landing, namely, spin-up and breaking phases, are reviewed. Second, a strategy to prevent excessive temperature and wear of the tyre is presented. Findings It is found that using a lubricant and coolant, such as water, at the spin-up stretch of the runway is a simple and practical solution to prevent excessive temperature and wear of the tyre. It is revealed that, despite increasing the spin-up period, the rise of the tyre temperature is eliminated and the material properties are preserved for effective braking. A rough quantitative analysis demonstrates that the wetting of tyres in the spin-up phase decreases the loads and tyre wear effectively. Practical implications Wetting the touchdown region of the runway without significant areas of standing water is the most practical strategy with the technology available today. Originality/value A new strategy is presented for landing with reduced tyre wear. It is the hope that this paper can inspire continuous efforts to realize the implementation of the strategy

Conceptual design of a new experimental setup to simulate aircraft tyre spin-up dynamics

The first touchdown moment of aircraft tyres on a runway is the critical phase where maximum of the vertical and horizontal ground loads is produced. Some valuable drop tests have been performed at Langley research centre to simulate the touchdown and the spin-up dynamics. However, a long impact basin and a huge power source to accelerate and decelerate the landing gear mechanism have been used. Based on a centrifugal mechanism, the purpose of this paper is to propose the conceptual design of a new experimental setup to simulate the spin-up dynamics. Design/methodology/approach A schematic view of the proposed mechanism is presented, and its components are introduced. Operating condition of the system and the test procedure are discussed in detail. Finally, tyre spin-up dynamics of Boeing 747 is considered as a case study, and operating condition of the system and the related test parameters are extracted. Findings It is shown that the aircraft tyre spin-up dynamics can be simulated in a limited laboratory space with low energy consumption. The proposed setup enables the approach velocity, sink rate and vertical ground load to be adjusted by low power actuators. Hence, the proposed mechanism can be used to simulate the tyre spin-up dynamics of different types of aircraft. Research limitations/implications It is important to note that more details of the setup, including the braking and actuating mechanisms together with their control procedures, should be clarified in practice. In addition, the curved path introduced as the runway will cause errors in the results. Hence, a compromise should be made between the tyre pressure, path curvature, the induced error and the cost of the experimental setup. Practical implications The proposed experimental setup could be constructed in a limited space and at a relatively low cost. Low power actuators are used in the proposed system. Hence, in addition to the performance tests, fatigue tests of the landing gear mechanism will also be possible. Originality/value Based on a centrifugal mechanism, the conceptual design of a new experimental setup is presented for simulating the tyre spin-up dynamics of aircraft. Considering that the drag load developed during tyre spin-up following initial touchdown is an important factor governing the design of the landing gear mechanism and aircraft structure, the authors hope this paper encourages engineers to continuously make efforts to increase the transparency of the touchdown process, enabling optimisation of landing gear design

The Moral Advice of ‘Minooye Kherad’ and its Effect on Ferdowsi’s Shahnameh

‘Minooye Kherad’ is one of the most significant letters of advice in the Middle Persian Period and the Pahlavi literature, including the books of Behdinan. This rather short book is full of the wise and beautiful religious and practical advice in diverse fields. Shahnameh, the master piece of Ferdowsi is the essence and protector of the ancient Persian culture. The research focuses on whether the book ‘Minooye Kherad’ has influenced the contents of Shahnameh or not. It also studies whether Ferdowsi has been inspired by this book or not. The descriptive-analytic methodology is based on studying the books, articles and analyzing different data. The result of this research indicated that Shahnameh has been influenced by this short book in the concepts related to moral advice. The great role of wisdom in Shahnameh emerges from the culture of Ancient Persia. And the book ‘Minooye Kherad’ has had a significant role in transferring this valuable characteristic. Ferdowsi is not the creator of these moral concepts, but he has added to the richness of these moral concepts by the help of his literal and artistic talents and has offered them to his audiences in his Masterpiece‘Shahnameh’

Introducing dusty plasma particle growth of nanospherical titanium dioxide

In dusty plasma environments, the spontaneous growth of nanoparticles from reactive gases has been extensively studied for over three decades, primarily focusing on hydrocarbons and silicate particles. Here, we introduce the growth of titanium dioxide, a wide band gap semiconductor, as dusty plasma nanoparticles. The resultant particles exhibited a spherical morphology and reached a maximum homogeneous radius of 230 $\pm$ 17 nm after an elapsed time of 70 seconds. The particle grew linearly and the growth displayed a cyclic behavior; that is, upon reaching their maximum radius, the largest particles fell out of the plasma, and a new growth cycle immediately followed. The particles were collected after being grown for different amounts of time and imaged using scanning electron microscopy. Further characterization was carried out using energy dispersive X-ray spectroscopy, X-ray diffraction and Raman spectroscopy to elucidate the chemical composition and crystalline properties of the maximally sized particles. Initially, the as-grown particles after 70 seconds exhibited an amorphous structure. However, annealing treatments at temperatures of 400 $^\circ$C and 800 $^\circ$C induced crystallization, yielding anatase and rutile phases, respectively. Notably, annealing at 600 $^\circ$C resulted in a mixed phase of anatase and rutile. These findings open new avenues for a rapid and controlled growth technique of titanium dioxide as dusty plasma.Comment: 8 pages, 5 figure

The application of hybrid model for identifying and ranking indicators for assessing the sustainability of waste water treatment systems

This paper proposes a combination of the Fuzzy Delphi and Fuzzy Analytic Hierarchy Process (FAHP) as an efficient tool for dealing with complex decision-making problems and to prove that integrating the Fuzzy Delphi and FAHP modeling is an objective and practical process. The application of these methods allows a large amount of information to be aggregated in a rigorous manner. The suggested fuzzy set theory helps to represent the uncertainty and vagueness of human’s subjective thinking process in dealing with decision problems. This hybrid approach enables decision-makers to evaluate priorities more efficiently and objectively and make the decision process more reliable. Therefore, the main goal of the present research is to develop this decision support approach to identify the key evaluation criteria and indicators in the process of selecting industrial wastewater treatment technology (WTT) from a sustainability perspective based on expert opinion and questionnaires. Since a realistic evaluation needs to be conducted in an actual condition, Iran’s steel industry was selected as the case study. In this research, based on the findings of the literature review and Fuzzy Delphi method screening, several evaluation criteria and indicators are identified. Then, the FAHP is employed to examine their relationships under a hierarchy structure and to determine their weights and priorities. The findings of this paper can be applied as a reference for the steel industry in decision-making for the selection of the optimal wastewater treatment technology. In addition, other industries can apply this feasible and practical approach in their decision-making process with respect to their differences in capacities, limitations, wastewater characteristics and local conditions