Display omitted
•Development of a sensitive chemiluminescence (CL) detection method for tramadol.•Encapsulation of Cu nanoclusters in 2D Cu metal-organic frameworks (CuNCs@CuMOF).•Tremendous ...enhancing effect of CuNCs@CuMOF on CL emission of rhodamine 6G (R6G).•Increasing effect of tramadol on the CL emission of R6G-KMnO4-CuNCs@CuMOF system.•Extraction of tramadol using magnetic MIP-Fe3O4@SiO2 NPs, before the CL analysis.
Herein, a high performance chemiluminescence (CL) system is developed for the sensitive detection of tramadol. The CL reaction is based on the direct oxidation of rhodamine 6 G (R6 G) by potassium permanganate (KMnO4), producing an ultra-weak emission. It was found that copper nanoclusters encapsulated in copper-based two-dimensional metal-organic frameworks (CuNCs@CuMOF) create a tremendous enhancing effect on the observed emission. A probable mechanism was also suggested for CL emission based on the catalytic effects of nanomaterial and chemiluminescence resonance energy transfer (CRET) events. Besides, it was observed that tramadol caused a relatively selective increasing effect on the CL emission of R6 G-KMnO4-CuNCs@CuMOF system. In order to guarantee a selective response for tramadol, an extraction process using molecularly imprinted polymer modified Fe3O4@SiO2 nanoparticles (MIP-Fe3O4@SiO2 NPs) was applied before the CL analysis. The dispersed MIP-Fe3O4@SiO2 NPs showed high specificity for the extraction of tramadol from its samples. The combination between the high improved CL detection system and the efficient extraction process caused an ultrasensitive and selective determination method for tramadol. The best linear calibration graph was obtained in the concentration range of 0.0030–2.5 μM tramadol, with a detection limit (3Sb/m) of 0.80 nM. The illustrated CL method was tested for the quantification of tramadol in biological fluids, which led to the acceptable and reliable results.
AbstractAs every other business, there are a variety of risks in the banking industry, including operational risks. The Central Bank of the Islamic Republic of Iran, as the Basel Committee, has ...required computing and managing the operational risk for banks and financial institutions. Accordingly, the goal of this study is to evaluate the operational risk management in banks based on the Basel II accord methodology. This study is of case study type. That is to achieve the research purpose, the Bank Hekmat Iranian (merged with Bank Sepah) was chosen as a young bank in Iran. Due to access to the bank's financial statements, no sampling was used and all audited statements of this bank over 2011 to 2016 were selected as the statistical population of the study. Then, the operational risk of this bank was calculated using two "Basic Indicator" and "Standardized" approaches based on the Basel II accord methodology. Also, the Central Bank of the Islamic Republic of Iran directive were used to identify different groups of bank activity in Standardized method.Descriptive statistics were used for data analysis. The results represent an ascending slope in operational risk in this bank over the research period. Due to the impact of the volume and the extent of banks' operations on the operating risk, this result could be due to an increase in the scope and volume of the operations in the bank during these years, which has directly affected the operational risk. This paper, while providing a relatively comprehensive and coherent literature about the operational risk, also provides details for calculating of this risk in banks. These details are based on the bank’s audited financial statements and can be used as a pattern to calculate operational risk in other banks.IntroductionEvery economic activity is exposed to risk. Because economic activities deal with the future and the future is always faced with risk and uncertainty. Credit and financial institutions are no exception. These institutions face a variety of risks, including credit risk, market risk and operational risk. Operational risk is the risk associated with the way a bank operates and manages its operations. Every risk arising from the way a bank operates is somehow indicative of operational risk. Operational risk factors can be within the organization (eg management and staff performance) or outside the organization (eg natural disasters). The variety of factors that can lead to operational risk has made it difficult to measure this risk. Each bank's management must identify mechanisms for identifying and managing the risk and mobilize organizational culture to control and mitigate this risk. As described above, it is essential that banks and financial institutions are actively involved in the risk management process in order to monitor, manage and measure operational risk. They must have methods for quantifying operational risk so that they can calculate and control and mitigate this risk in their management scope. Therefore, the main question in this study is how much a bank's operational risk is according to the Basel II accord methodology.Case studyThis study is of case study type and the statistical population of the study is the data extracted from the audited financial statements of the Bank Hekmat Iranian (merged with Bank Sepah) during the research period. Since access to this data is feasible for the purpose of this study, sampling has not been used and the entire statistical population has been investigated.Materials and MethodsFollowing Basel II (2006) and Central Bank of the Islamic Republic of Iran (2007) instructions, the “basic index” and the “standardized” approaches are used to calculate operational risk. In the “basic index” approach, a bank's operational risk per year equals a constant percentage of the bank's average earnings over the last three years. The “standardized” approach is similar to the “basic index” approach, except that it takes into account the fact that operational risk can vary between different segments of banks' operations. The “standardized” approach divides the bank's activities into eight working groups and considers for each working group a separate percentage of the average gross income as the operating risk for that group. Descriptive statistics were used to analyze and interpret the results.Discussion and ResultsThe results showed that although the amount of operational risk in the “basic index” and the “standardized” approaches is slightly different and is greater in “standardized” approach than the “basic index” approach, but both methods show an increasing slope for the operational risk since 2014 to 2017. This means that the operating risk for Bank Hekmat Iranian has increased over these years.ConclusionThe results can be interpreted as having a significant increase in the volume and scope of operations of the Bank Hekmat Iranian (merged with Bank Sepah) from 2014 to 2017, the risk associated with these operations has been increased too. Since the scope of operational risk is very wide and encompasses almost all aspects of bank activity, it is natural that as the scope of bank operations broadens, operating risk will increase. Of course, this increase is due to the expansion of the bank's operations and its upward trend and does not necessarily have a negative message for the bank. Because the higher the risk, the higher the return. Banks may rely on the output of the standardized approach to apply more stringent and maximum precautionary measures and consider larger precautionary reserves to cover the capital required for operational risk.
In the present work, Ag nanoparticles were added to polyurea coating in order to improve its antibacterial and electrochemical properties in sulfide-reducing bacteria-containing media. To this end, ...Ag nano-powder was mixed with two component polyuria, and then the antibacterial behavior of the nanocomposite coating was studied in sulfate-reducing bacteria (SRB)-containing medium. The results revealed the inhibitory effects of nanocomposite coating on the formation of SRB biofilms on the samples. Moreover, the SRB population decreased in contact with the Ag nanoparticles-mixed coating over 7 days. Investigation of the growth and activity of the bacteria represented the effective antibacterial properties of Ag nanoparticles in the polyurea matrix. Furthermore, EIS (electrochemical impedance spectroscopy) measurements indicated that the corrosion properties of the nanocomposite coating improved considerably over 7 days. The coating resistance increased 2 times by adding Ag nanoparticles after 1 day and 3.3 times after 7 days. In accordance with the same results, the charge transfer resistance increased 1.5 times and 1.1 times by adding Ag nanoparticles after 1 day and 7 days, respectively. The improvement in the protective properties of the nanocomposite coating are reflected in the increase in both film and charge transfer resistance.
•New adsorbent was introduce by coupling 1-butyl-3-methylimidazolium bromide impregnated chitosan hydrogel beads.•A high performance systems was design for removal of cationic dye.•Kinetic study of a new system for removal of cationic dye.
Grade estimation is a vital issue in ore reserve evaluation extensively investigated by data mining methods. There are significant relationships between mineralization and grade and separation of ...mineralized zones. This study aims to estimate the concentration using geostatistical and artificial neural network (ANN) techniques and to separate mineralized zones by concentration–volume (C–V) fractal model. The information used in this study includes iron concentration analysis of two-meter composites from 29 exploratory boreholes in Lakeh Siah orebody, Central Iran. The grade block model was created using variograms via the kriging estimator (simple and ordinary kriging) and an artificial neural network for three-dimensional modeling. Logarithmic-logarithmic concentration-volume plots were drawn based on grade estimation methods, and different mineralized areas were separated using threshold values. Comparison and interpretation of mineralization areas based on concentration-volume fractal modeling showed a similarity between the variance trends of the simple kriging and ordinary kriging methods in all domains. Also, the artificial neural network method result in high-grade sections is similar to the other two trends. The optimal threshold values for the enriched mineralization areas, high, middle, and low-concentration, were 58, 52, 43, and 34%, respectively. The obtained results proved that ANN is a simple and reliable method and does not require complex mathematical modeling. This method can only perform simple calculations to identify the grade distribution pattern. Unlike geostatistical methods, ANN does not need any assumptions about the grade distribution and does not use any weights, hypothetical effect radius, or fitted model to the variogram. Furthermore, this method does not require any hypotheses about the relationship between distance and grade. Therefore, this method can be used for other research and applied fields with high reliability.
During recent years, water production from atmospheric air has been widely introduced as one of the most promising solutions for providing remote regions with potable water. An experimental ...investigation was conducted here on a newly designed solar still-assisted thermoelectric cooling atmospheric water generation (TEC-AWG) system in order to evaluate the influence of various operating factors such as solar radiation intensity, ambient and TEC channel outlet temperatures, relative humidity, as well as the effect of insulating the TEC channel, and utilizing photovoltaic power (PV) on water production and system performance. In order to increase the moisture content of the TEC channel inlet air; the incoming air was directed via a solar still prior to its entrance through the TEC channel. Tests were performed under realistic climate conditions of Babol, Iran (36.53° N, 52.67° E), over nine typical summer days. Three sets of comparative experiments were carried out between a backup powered-TEC channel without insulation (Model A as the reference model), a backup powered-TEC channel with insulation (Model B), and a PV-powered TEC channel with insulation (Model C). The obtained results demonstrated average annual production of 845, 2064, and 1315 L/m
2
for models A, B, and C, respectively. These data correlate to 144.3% (for Model B) and 55.6% (for Model C) increase in average annual production. Maximum average annual production of 2064 L/m
2
which was acquired during Model B experiments, is higher than that of reported for a simple solar still (i.e., ∼ 1511 L/m
2
). Additionally, system performance (i.e., the ratio between the generated water and consumed power); of 0.07, 0.20 and 0.30 mL/Wh was obtained for models A, B, and C, respectively. These data imply the superiority of Model B in terms of water production and Model C in terms of system performance. Comparing the system preperformance results of the models B and C with some previous studies, demonstrates the viability of the current design and therefore, the present newly designed setup can be effectively utilized as a reliable AWG device.
— In this paper, our goal is to simulate abrasion resistance material. We therefore need a robust algorithm to model this phenomenon which is a kind of large frictional contact problem. In order to ...reach to our aim, we have proposed a new method to impose contact constraints in eXtended Finite Element Method (XFEM) framework. In this algorithm, we have modeled large sliding contact problems by using the Node To Segment (NTS) concept. Furthermore, friction between two sliding interface has been modeled based on the Coulomb friction law. In addition, the penalty method which is the most convenient way of imposing non-penetration constraints has been employed. In our algorithm, new Lagrangian shape functions have been used to solve the problems of the conventional Heaviside enrichment function. Finally, a numerical simulation has been delivered to prove the accuracy and capability of our new algorithm.
PDF
