Risk assessment of blasting operations in open pit mines using FAHP method

Purpose. In the mining blasting operation, fragmentation is the most important output. Fly rock, ground vibration, air blast, and environmental effects are detrimental effects of blasting operations. Identifying and ranking the risk of blasting operations is considered as the most important stage in project management. Methods. In this research, the problem of identifying and ranking the factors constituting the risk in blasting operations is considered with the methodology of the Fuzzy Analytical Hierarchy Process (FAHP). Criteria and sub-criteria have been determined based on historical research studies, field studies, and expert opinions for designing a hierarchical process. Findings. Based on FAHP scores, non-control of the sub-criterion of health and safety (C3), blast operation results (C18) and knowledge, and skill and staffing (C2) with a score of 0.377, 0.334, and 0.294 respectively are the most effective sub-criterion for the creation of blasting operations risk. According to the score, the sub-criterion C18 is the most effective sub-criterion in providing the blasting operations risk. Effects and results of blasting operations (D8), with a score of 0.334 as the most effective criterion, and natural hazards (D10), with a score of 0.015, were the last priorities in the factors causing blasting operations risk. Originality. Regarding the risk rating of blasting operations, the control of the sub-criteria C3, C18, and C2, and the D8 criterion, is of particular importance in reducing the risk of blasting operations and improving project management. Practical implications. The evaluation of human resource performance and increase in the level of knowledge and skills and occupational safety and control of all outputs of blasting operations is necessary. Therefore, selecting the most important project risks and taking actions to remove them is essential for risk management.Мета. Визначення ризиків проведення вибухових робіт та їх оцінка на основі використанням нечіткого методу аналізу ієрархій (НМАІ) для покращення управління якістю проектів. Методика. В рамках даного дослідження, проблеми визначення та оцінки ризиків вибухових робіт розглядалися із застосуванням нечіткого методу аналізу ієрархій. На базі аналізу історичних даних і польового дослідження з урахуванням експертних оцінок були визначені критерії та підкритерії для побудови ієрархій. Результати. За результатами НМАІ, неконтролюючий підкритерій здоров’я та безпеки (С3), підкритерій результатів вибухових робіт (С18), знань, умінь і кадрів (С2) зі значеннями 0.377, 0.334 і 0.294 відповідно найбільш ефективні в появі ризику проведення вибухових робіт. Підкритерій С18 чинить найбільший вплив на ризик проведення вибухових робіт. Критерій результатів і наслідків вибухових робіт (D8) з найефективнішим значенням 0.334 та критерій природних катастроф (D10) зі значенням 0.015 є останніми пріоритетами серед чинників, які визначають ризик проведення вибухових робіт. Наукова новизна. Отримав доповнення та подальший розвиток науково-методичний підхід до визначення ризиків при проведенні вибухових робіт, заснований на їх ранжуванні з використанням системи виявлених критеріїв і підкритеріїв методом НМАІ. Практична значимість. Для успішного керування проектом важливо визначати найсерйозніші ризики проекту й вжити заходів щодо їх усунення. Відносно ранжирування ризиків проведення вибухових робіт управління підкритеріями C3, C18 і C2, а також критерієм D8, особливо важливо для зниження цих ризиків та покращення якості управління проектом.Цель. Определение рисков проведения взрывных работ и их оценка на основе использования нечеткого метода анализа иерархий (НМАИ) для улучшения управления качеством проектов. Методика. В рамках данного исследования, проблемы определения и оценки рисков взрывных работ рассматривались с применением нечеткого метода анализа иерархий. На базе анализа исторических данных и полевого исследования с учетом экспертных оценок были определены, критерии и подкритерии для построения иерархий. Результаты. По результатам НМАИ, неконтролирующий подкритерий здоровья и безопасности (С3), подкритерий результатов взрывных работ (С18), знаний, умений и кадров (С2) со значениями 0.377, 0.334 и 0.294 соответственно наиболее эффективны в появлении риска проведения взрывных работ. Подкритерий С18 оказывает самое большое влияние на риск проведения взрывных работ. Критерий результатов и последствий взрывных работ (D8) с самым эффективным значением 0.334 и критерий природных катастроф (D10) со значением 0.015 являются последними приоритетами среди факторов, которые определяют риск проведения взрывных работ. Научная новизна. Получил дополнение и дальнейшее развитие научно-методический подход к определению рисков при проведении взрывных работ, основанный на их ранжировании с использованием системы выявленных критериев и подкритериев методом НМАИ. Практическая значимость. Для успешного руководства проектом важно определять самые серьезные риски проекта и предпринять действия по их устранению. В отношении ранжирования рисков проведения взрывных работ управление подкритериями C3, C18 и C2, а также критерием D8, особенно важно для снижения этих рисков и улучшения руководства проектом.The authors would like to thank Mining Engineering Department, Islamic Azad University (South Tehran Branch) for supporting this research

Enhanced catalytic activity of natural hematite-supported ppm levels of Pd in nitroarenes reduction

In this work, Pd NPs supported on amine-modified natural hematite have been prepared and characterized. Using this simple catalyst, nitroaromatic compounds as a major cause of industrial pollution were reduced to corresponding amines with ppm levels of Pd in the presence of designer surfactant TPGS-750-M and NaBH4 at room temperature in aqueous media. Synergistic effect between hematite and Pd is responsible for the observed enhanced catalytic activity. This catalyst was recycled for at least four times with a small decrease in the activity.The authors are grateful to Institute for Advanced Studies in Basic Sciences (IASBS) Research Council and Iran National Science Foundation (INSF-Grant number of 97021804) for support of this work. We also gratefully acknowledge financial support from the Spanish Ministerio de Economía y Competitividad (MINECO) (projects CTQ2013-43446-P and CTQ2014-51912-REDC), the Spanish Ministerio de Economía, Industria y Competitividad, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER, EU) (projects CTQ2016-76782-P and CTQ2016-81797-REDC), the Generalitat Valenciana (PROMETEOII/2014/017) and the University of Alicante

Analyses of tunnel stability under dynamic loads

Tunnels as any other structures are affected by different loads and stresses. Generally, the loads on tunnels consist of both static and dynamic loads. These loads must both be considered in the tunnel design process. In this paper, the stability state of Jiroft water-transform tunnel is evaluated. Firstly, the in-situ stresses and then using Kirschs equations the induced stresses due to static loads in walls and crown of tunnel are calculated. Consequently, the strain caused by probable earthquake without considering the interaction between the concrete lining of tunnel and rock mass using seismic analysis is calculated based on free-field deformation. When the strain is determined, the simplified method of closed-form solution, Wangs equations and Penziens equations are used to estimate the applied forces on the tunnel due to earthquake such as axial force and bending moment on a tunnel section taking into account the interaction of the tunnel concrete lining and rock mass. Results of this study show that the loads applied to the tunnel as a result of earthquake waves can be affect the stability of underground structures, especially long structures such as tunnels.Accepted versio

Multiobjective Optimized Smart Charge Controller for Electric Vehicle Applications

The continuous deployment of distributed energy sources and the increase in the adoption of electric vehicles (EVs) require smart charging algorithms. The existing EV chargers offer limited flexibility and controllability and do not fully consider factors (such as EV user waiting time and the length of next trip) as well as the potential opportunities and financial benefits from using EVs to support the grid, charge from renewable energy, and deal with the negative impacts of intermittent renewable generation. The lack of adequate smart EV charging may result in high battery degradation, violation of grid control statutory limits, high greenhouse emissions, and high charging cost. In this article, a neuro-fuzzy particle swarm optimization (PSO)-based novel and advanced smart charge controller is proposed, which considers user requirements, energy tariff, grid condition (e.g., voltage or frequency), renewable (photovoltaic) output, and battery state of health. A rule-based fuzzy controller becomes complex as the number of inputs to the controller increases. In addition, it becomes difficult to achieve an optimum operation due to the conflicting nature of control requirements. To optimize the controller response, the PSO technique is proposed to provide a global optimum solution based on a predefined cost function, and to address the implementation complexity, PSO is combined with a neural network. The proposed neuro-fuzzy PSO control algorithm meets EV user requirements, works within technical constraints, and is simple to implement in real time (and requires less processing time). Simulation using MATLAB and experimental results using a dSPACE digital real-time emulator are presented to demonstrate the effectiveness of the proposed controller

Applications of bimetallic PdCu catalysts

Bimetallic PdCu nanoparticles can be applied as catalysts in a wide range of chemical and electrochemical reactions. This review article overviews the preparation and synthetic applications of these bimetallic nanoparticles (BNPs) developed mainly over the last 20 years. These BNPs show better catalytic activity and selectivity than the monometallic counterparts due to their electronic and structural interactions. Simple general preparation methods include reduction of the corresponding salt precursors by different agents, solvothermal processes and galvanic replacement. In the case of supported catalysts, mainly wet impregnation and in situ reduction processes are used. In addition, these nanomaterials are prepared with different Pd/Cu compositions and with different morphologies. In the case of supported materials, many solid supports especially alumina, silica, titania, ceria, magnetite, zeolites, active carbon, graphene, carbon nanotubes, resins and polymers are employed allowing the recovery and reuse of the supported catalyst. In addition, the presence of copper reduces the economic cost of using palladium in industrial processes. Among several synthetic applications, C–C bond forming reactions such as Suzuki–Miyaura, Sonogashira–Hagihara, Heck–Mizoroki, Guerbet and A3-coupling are efficiently performed with PdCu BNPs. Reduction reactions under PdCu catalysis such as nitrate reduction for water purification, hydrodechlorination of organic pollutants, hydrogenation of CO2 and CO to methanol, semihydrogenation of alkynes to alkenes, and hydrogenation of C[double bond, length as m-dash]C double bonds, furfural to furfuryl alcohol, polyols, levulinic and succinic acids to lactones, styrene oxide to 2-phenylethanol and nitroaromatics to aromatic amines can be successfully performed. In the case of electrocatalytic reductions, oxygen reduction to water, CO2 reductions to CO, to alcohols, to hydrocarbons and to formate and hydrogen generation from water splitting can be highlighted. In the field of oxidation reactions using oxygen, CO can be transformed into CO2, alcohols into aldehydes, cyclopentene to cyclopentanone, ethylene and acetic acid to vinyl acetate, and aromatic compounds can be hydroxylated to phenols. Electrooxidation reactions are useful processes especially for direct alcohol and formic acid fuel cells. The oxygen-assisted water gas shift reaction can be efficiently performed under PdCu catalysis. In the field of chemical sensors, PdCu BNPs can detect hydrogen in low concentrations, liquefied petroleum gas, formaldehyde, glucose, thiocyanate and phenols. Other applications such as catalysts in hydrosilylation of acetylenes to vinylsilanes and the use of PdCu NPs as antimicrobial agents are also described.The authors are grateful to the Institute for Advanced Studies in Basic Sciences (IASBS) Research Council and Iran National Science Foundation (INSF-Grant number of 97016837) for support of this work. We also thank the Spanish Ministerio de Economía, Industria y Competitividad, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER, EU) (projects CTQ2016-76782-P, CTQ2016-81797-REDC, and CTQ2017-85093-P), the Generalitat Valenciana (PROMETEOII/2014/017) and the University of Alicante for financial support

1-Butyl-3-methyl-2-(diphenylphosphino)imidazalolium hexafluorophosphate as an efficient ligand for recoverable palladium-catalyzed Suzuki-Miyaura reaction in neat water

The 1-butyl-3-methyl-2-(diphenylphosphino)imidazalolium hexafluorophosphate is prepared and used as a water-soluble ligand in the Suzuki-Miyaura reaction. This ligand and palladium chloride generates a new active catalyst for the Suzuki coupling reaction between aryl iodides or bromides with arylboronic acids in neat water. This catalyst can be recycled and reused for the coupling reaction of 4-bromobenzonitrile with phenylboronic acid for at least six runs with low decreasing in catalytic activity.The authors are grateful to Institute for Advanced Studies in Basic Sciences (IASBS) Research Council and Iran National Science Foundation (INSF-Grant number of 97021804) for support of this work. We also gratefully acknowledge financial support from the Spanish Ministerio de Ciencia e Innovaci on (MICINN) (projects CTQ2010-20387 and Consolider Ingenio 2010, CSD2007-00006), the Spanish Ministerio de Economía y Competitividad (MINECO) (projects CTQ2013-43446-P and CTQ2014-51912-REDC), the Spanish Ministerio de Economía, Industria y Competitividad, Agencia Estatal de Investigaci on (AEI) and Fondo Europeo de Desarrollo Regional (FEDER, EU) (projects CTQ2016-76782-P and CTQ2016-81797-REDC), the Generalitat Valenciana (PROMETEO2009/039 and PROMETEOII/2014/017), the University of Alicante

Synthesis of 5-heptadecyl- and 5-heptadec-8-enyl substituted 4-amino-1,2,4-triazole-3-thiol and 1,3,4-oxadiazole-2-thione from (Z)-octadec-9-enoic acid: preparation of Palladium(II) complexes and evaluation of their antimicrobial activity

Two 4-amino-1,2,4-triazoles and two 1,3,4-oxadiazoles are obtained in a common synthetic route including hydrogenation-hydrazidation of (Z)-methyl octadec-9-enoate to octadecanoic hydrazide under atmospheric air. Preservation of olefinic bond in heptadec-8-enyl group is achieved by carrying out hydrazidation reaction under the presence of an argon atmosphere. The disappearance of the olefinic bond is detected by physical data, IR, 1H, and13C NMR spectroscopy. New palladium complexes derived from 4-amino-5-heptadecyl-1,2,4-triazole-3-thiol and 5-heptadecyl-1,3,4-oxadiazole-2(3H)-thione are obtained and characterized by elemental analysis (solid state), IR, 1H, 13C NMR spectroscopy, XRD, and XPS. These resulting metallic entities are also identified in solution based in mass spectrometry (MS-ESI) experiments. Most compounds and their palladium(II) complexes are tested in vitro against Gram-positive, Gram-negative bacteria, and fungi, some of them showed variable activity.Financial support was provided by the Spanish Ministerio de Ciencia e Innovación (MICINN) (projects CTQ2010-20387, and Consolider-Ingenio 2010, CSD2007-00006), the Spanish Ministerio de Economía y Competitividad (MINECO) (projects CTQ2013-43446-P, and CTQ2014-51912-REDC), FEDER, the Generalitat Valenciana (PROMETEO 2009/039 and PROMETEOII/2014/017) and the University of Alicante. One of us (M.C.) thanks USTO-MB for scientific leave

Comparison of antimicrobial sensitivity to older and newer quinolones versus piperacillin-tazobactam, cefepime and meropenem in febrile patients with cancer in two referral pediatric centers in Tehran, Iran

Background: Infection in pediatric cancer patients has become a concerning problem due to increasing antimicrobial resistance. The goal of this study was to determine the antimicrobial resistance patterns of blood isolates from pediatric oncology patients in Iran to determine if there was significant resistance to quinolones. Methods: Children with cancer who were admitted with or developed fever during admission to Aliasghar Children's Hospital or Mahak Hospitals July 2009 through June 2011 were eligible for enrollment. Two blood cultures were obtained. Antimicrobial sensitivity test was performed for ciprofloxacin, moxifloxacin, gatifloxacin, meropenem, cefepime, and piperacillin-tazobactam on isolates from children who were bacteremic. Results: Blood cultures were positive for 38 episodes in 169 enrolled children but 9 episodes were excluded as blood cultures were thought to be contaminated, yielding a bacteremia rate of 29/160 (18). The mean age of children and the stage of malignancy did not differ between those with and without bacteremia. Meropenem was the most likely antibiotic to cover isolates (97) with cefepime having the lowest coverage rate (21). Quinolone coverage ranged from 63 to 76. Conclusion. Quinolones may not be suitable for use as empiric therapy in febrile pediatric oncology patients in Iran