Blacksmith: Fast Adversarial Training of Vision Transformers via a Mixture of Single-step and Multi-step Methods

Despite the remarkable success achieved by deep learning algorithms in various domains, such as computer vision, they remain vulnerable to adversarial perturbations. Adversarial Training (AT) stands out as one of the most effective solutions to address this issue; however, single-step AT can lead to Catastrophic Overfitting (CO). This scenario occurs when the adversarially trained network suddenly loses robustness against multi-step attacks like Projected Gradient Descent (PGD). Although several approaches have been proposed to address this problem in Convolutional Neural Networks (CNNs), we found out that they do not perform well when applied to Vision Transformers (ViTs). In this paper, we propose Blacksmith, a novel training strategy to overcome the CO problem, specifically in ViTs. Our approach utilizes either of PGD-2 or Fast Gradient Sign Method (FGSM) randomly in a mini-batch during the adversarial training of the neural network. This will increase the diversity of our training attacks, which could potentially mitigate the CO issue. To manage the increased training time resulting from this combination, we craft the PGD-2 attack based on only the first half of the layers, while FGSM is applied end-to-end. Through our experiments, we demonstrate that our novel method effectively prevents CO, achieves PGD-2 level performance, and outperforms other existing techniques including N-FGSM, which is the state-of-the-art method in fast training for CNNs

Removal Efficiency of Electrochemical Process by Iron Oxide Nanoparticles Impregnated on Rod Carbon for Arsenite Anions in a High Ionic Strength Solution

The entry of heavy metals (e.g., arsenite anions) into water sources due to industrial and mining activities is considered a serious problem for the environment. Therefore, arsenite removal from polluted water has attracted the attention of researchers due to its toxic effects on human health. In the present study, the efficiency of the electrochemical (EC) purification of arsenite anions in a high ionic strength solution was investigated using a carbon electrode impregnated with iron oxide nanoparticles (NPs). These NPs were synthesized by the co-precipitation method and immediately impregnated on the carbon rod. Experiments were performed by two electrodes (carbon and carbon impregnated with NP electrode) in a 50 mL EC reactor. The effect of different parameters such as electrical current (0.1, 0.3, 0.5, 0.7, & 0.9 A), EC time (2, 5, 10, 15, and 20 minutes), pH (3, 5, 7, 9, & 11), and the initial concentrations of arsenite anion (2, 5, 10, 15 and 20 mg/L) was investigated on the removal efficiency to achieve the highest removal of arsenite anions. Arsenite anions (10 mg/L) were completely removed from the aqueous solution with an ionic strength of 0.141 M at an electrical current of 0.7 A, a pH of 8, and an EC time of 20 minutes. In addition, pH was the most effective parameter in removing arsenite anions from aqueous solution in the EC method. According to the results, EC treatment using an electrode impregnated with iron oxide NPs is highly efficient in removing arsenite anions from the contaminated water

Wastewater treatment efficiency in stabilization ponds, Olang treatment plant, Mashhad, 2011-13

Olang wastewater treatment facilities purifying raw urban wastewater consist of two stabilization pond modules. Both are on operation in parallel. Functioning of natural systems is influenced by different factors including ambient condition. Considering final effluent of this system discharges to Kashafrood river and sometimes is used for agricultural purposes, assessing the quality parameters in effluent was the main objective of this study. This cross-sectional study investigated some important quality parameters for both raw and treated wastewater in two years periods. Data analysis was carried out using descriptive statistics. Statistical tests were done at a significant level of 0.05. Simple linear regression analysis was used only for modeling. Raw wastewater was almost severe. Average removal efficiency for BOD5, COD, and TSS was 81, 83, and 78% respectively. There wasn’t a meaningful relationship between the removal efficiency of mentioned parameters and input pH. Ambient temperature fluctuations were effective on BOD5, and COD reduction. SAR index didn’t show a considerable restriction on irrigation application of effluent. In 62.5% cases outlet Na content was at the extent to which restrictions were imposed. Olang wastewater treatment plant generates an acceptable effluent relating to most of the quality parameters that were measured in this study. Considering special status of Mashhad city, it is worthy to reuse effluent in areas with a high water requirement such as agriculture

Arsenic Oxidation Using UV-Activated Persulfate in Aqueous Solutions: Optimization Using Response Surface Methodology Based on Box-Bencken Design

Introduction: The use of arsenic contaminated water can cause a variety of adverse health effects in humans. Therefore, it is essential to seek out a method to remove arsenic more efficiently. This study examined the amount of arsenic oxidation by response surface methodology (RSM) based on Box-Bencken design. Materials and Methods: In this study, oxidizing arsenite to arsenate was performed by activation of persulfate with UV and the optimal conditions determined using the RSM based on Box-Bencken design to evaluate the effects of independent variables on the response (arsenite oxidation efficiency) performance and to predict the best response rate. In this study, the effects of different parameters such as pH (3-11), concentration of persulfate (4-14 mM), and initial concentration of arsenic (0.1-0.9 mg/l) on process efficiency were investigated. The number of tests in this study was 45, and the oxidation rate was measured using the UV visible spectrophotometer (DR 6000) and the molybdate colorimetric method. Results: Increasing the concentration of arsenic increased oxidation. However, with increasing pH, the oxidation rate decreased and the highest oxidation rate at all concentrations was observed at pH 3. The value higher than R2 (0.934) indicated that the oxidation of arsenic (v) could be determined by this model. Conclusion: Arsenite is a highly toxic metal that is difficult to remove by conventional treatment methods, but a pre-treatment phase can convert arsenite into arsenate and facilitate the removal process. In this study, the use of UV-activated persulfate increased the efficiency of arsenic oxidation to 96%

Modification of pomegranate waste with iron ions a green composite for removal of Pb from aqueous solution: equilibrium, thermodynamic and kinetic studies

Abstract Pomegranate waste modified with Fe2+ and Fe3+ ions followed with carbonization were used as an adsorbent to remove the Pb2+ ions from aqueous solution. To optimum the highest adsorption efficiency, adsorption experiments were conducted on iron modified carbons by batch technique. The characteristic of composite was studied by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR). The best pH for control of chemical adsorption was selected within pH of 6.0–6.5. It was observed that the contact time of 90 min, initial concentration 50.0 ppm, and adsorbent dose, 1.0 g/100 ml solution was found to be optimum conditions. On this condition, the maximum adsorption capacity was obtained 27.5 and 22.5 mg/g for Fe2+ and Fe3+ impregnated pomegranate peel carbons (PPC), respectively. The value of Cid, 1.584 for Fe2+-PPC and 0.552 for Fe3+-PPC, indicates that the effect of the boundary layer is more important in adsorption of Pb2+ by Fe2+-PPC and the pore diffusion is the rate limiting mechanism after 30 min. Thermodynamic parameters of Gibbs free energy, enthalpy, and entropy of Pb2+ adsorption on iron-modified carbons suggest that the adsorption process is favorable and spontaneous under the optimum condition

DNA structure spectroscopy by synthetic pigments using LED lighting

It is clear that DNA concentration and biological detection devices have many applications in the fields of genetics and biotechnology. For this goal, some similar devices have been designed working with the laser light which the disadvantages of them are high prices and the use of significant amounts of sample volume. But this designed device which works with LED light has very cheap manufacturing cost. The amounts of DNA used in this device are very low, about a few micro-liters and measurement of small, fast and portable it is also the advantages of these devices. The Data recorded as voltage versus time and the Fourier transform the frequency domain. From the frequency curve, by using the Byrlambrt it is possible to obtain the relative concentrations of DNA, viruses and assays measuring DNA damage and many other applications. By use of this device, the concentration of DNA colored with three different pigments was measured

Models and components in disaster risk communication: A systematic literature review

BACKGROUND AND AIM: Risk communication is considered a major factor in disaster risk management by the concerned policymakers and researchers. However, the incoherence of variables affecting risk communication in various studies makes it difficult to plan for disaster risk communication. This study aims to identify and classify the influential components in disaster risk communication. MATERIALS AND METHODS: This systematic review was conducted in 2020. Databases included PubMed, Scopus, and Web of Science. In searching for articles, there was no limit on the date of publication and the language of the article. The research addressed both natural and man-made disasters. The Preferred reporting items for systematic review and meta-analysis protocols (PRISMA) checklist was followed throughout the research, and the quality of the papers was assessed using the mixed methods evaluation tool (MMAT). RESULTS: In searching the articles, 3956 documents were obtained, of which 1025 duplicated articles were excluded. The titles and abstracts of the remaining documents (2931) were examined, of which 2822 were deleted, and the full text of 109 documents was studied for further assessment. Finally, after applying the inclusion and exclusion criteria and reviewing the full texts, 32 documents were considered to extract the data and for quality assessment. On studying the full text of the obtained documents, 115 components were found, which were classified into five groups (message, message sender, message receiver, message environment, message process) and 13 subgroups. In addition, the obtained components were classified as those proposed by the authors of the article and those obtained from disaster risk communication models. CONCLUSION: Identifying the effective components in the disaster risk communication gives a more comprehensive view of risk communication to the disaster managers and executives and provides the decision-makers with an important platform to be able to use the components of risk communication and increase the impact of messages and ultimately increase people's preparedness for disasters in planning operations for the risk communication

Performance Evaluation of Tile Wastewater Treatment with Different Coagulants

Introduction: The objective of this study was to investigate wastewater quality and the efficiency of removal of wastewater contaminants produced by a tile factory by using ferric chloride, ferrous sulfate, ferric sulfate, aluminum sulfate (alum) and poly-aluminum chloride (PAC) coagulants. Materials and Methods: This is an applied study. A composite sample was taken of the wastewater production line of the factory. Wastewater characteristics including pH, EC, temperature, turbidity, TSS, TDS, TS and COD were measured in accordance with the standard methods. In the next step, the jar-test experiment was used to investigate the effect of changing doses of coagulants (0.15, 0.2, 0.25, 0.3, 0.35 g/L) and pH values (7, 9, 11) on the removal of contaminants. The effective dose and optimal pH were thus selected and the best coagulant was later determined. Results: The optimum pH of 11 was obtained for removal of contaminants by ferric chloride, ferric, ferrous sulfate and 7 for alum and PAC. The optimum concentration of the five coagulants was obtained at 0.3, 0.3, 0.3, 0.25, 0.25 g/L respectively. PAC, with the turbidity removal EC, TSS, TS and COD removal of 99.92%,17.74%, 99.93%, 89.8%, 75% respectively, had best performance at lower doses and alum, ferrous sulfate, chloride, ferric and ferric sulfate were placed in the next rankings. Conclusion: Among the five studied coagulants, PAC is the most effective coagulant, and then alum, ferrous sulfate, ferric chloride and ferric sulfate are placed. Given that PAC is more expensive than other materials, care should be taken to select the most appropriate coagulant. &nbsp

Decolorization, COD and turbidity removal of the raw vinasse effluent by a one-step electro-oxidation process on a Pb/PbO2 anode

In this research, and for the first time, the application of anode Pb/PbO2 (prepared from combined thermal oxidation and electrochemical oxidation method) and steel cathode in a flow sample electrochemical treatment process of vinasse and in the wastewater of alcohol factories, has been investigated. The combination of electrodes of Pb/PbO2 as an anode, steel, and/or graphite as a cathode was used in the proposed electrochemical treatment setup. The efficiency of the proposed electrochemical treatment was determined by the removal percentage of chemical oxygen demand (COD), turbidity and color of vinasse samples. The response surface method (RSM) by Minitab 18 was used to determine the effect of the studied factors as well as to detect the relationship between variables. The results showed that under optimum conditions (Pb/PbO2 electrode as the anode and steel electrode as the cathode, a voltage of 30 V, pH 6.5, and reaction time of 45 min), the percentage reduction values of COD, turbidity and color were 97.7, 77.3 and 92.7%, respectively. HIGHLIGHTS Removal of organic pollutants from vinasse through indirect oxidation to CO2 and H2O.; Designing a simple laboratory electrochemical system for the purification of raw vinasse.; Treatment without sample pretreatment, dilution and addition of auxiliary reagents.; Reducing the poisoning of the electrode surfaces by the circulation of raw vinasse.; The possibility of purifying complex matrices (vinasse) with high efficiency in a short period of time.