132 research outputs found
Optimization of electrocoagulation process to treat biologically pretreated bagasse effluent
The main objective of the present study was to investigate the efficiency of
electrocoagulation process as a post-treatment to treat biologically
pretreated bagasse effluent using iron electrodes. The removal of chemical
oxygen demand (COD) and total suspended solids (TSS) were studied under
different operating conditions such as amount of dilution, initial pH,
applied current and electrolyte dose by using response surface methodology
(RSM) coupled with four-factor three-level Box-Behnken experimental design
(BBD). The experimental results were analyzed by Pareto analysis of variance
(ANOVA) and second order polynomial mathematical models were developed with
high correlation of efficiency (R2) for COD, TSS removal and electrical
energy consumption (EEC). The individual and combined effect of variables on
responses was studied using three dimensional response surface plots. Under
the optimum operating conditions, such as amount of dilution at 30 %, initial
pH of 6.5, applied current of 8 mA cm-2 and electrolyte dose of 740 mg l-1
shows the higher removal efficiency of COD (98 %) and TSS (93 %) with EEC of
2.40 Wh, which were confirmed by validation experiments
Optimization of electrocoagulation process for treatment of rice mill effluent using response surface methodology
The present work explores the impact of electro coagulation (EC) method on the treatment of waste from rice mill industries using two different electrode materials (Iron (Fe) and Aluminum (Al)). The influence of different parameters such as inter-electrode distance (4-7 cm), effluent pH (6-8), current density (10-30 mA/cm2) and treatment time (20-40 min) on the reduction of chemical oxygen demand (COD), total dissolved solids (TDS) and total soluble solids (TSS) of rice mill effluent (RME) was evaluated through batch experimental runs using BoxBehnken design. Results reveal that the percentage removal of COD, TDS and TSS increased up to an interelectrode distance of 6 cm, pH of 7, current density of 20 mA/cm2 and treatment time of 30 min and then decreased for both electrodes. In addition, mathematical models were developed for both electrodes in order to predict the experimental data. A numerical optimization method was applied to find out the optimal operating parameters to treat RME, and the percentage removal of COD, TDS and TSS was found to be 94.79, 96.62 and 88.76 %, using the Al electrode, as well as 76.63, 78.51 and 72.03 %, for the Fe electrode, respectively. The comparison of the results attained demonstrate that the Al electrode is more suitable to treat RME than Fe using EC method
Deep neural network models for colon cancer screening
Early detection of colorectal cancer can significantly facilitate clinicians’ decision-making and reduce their workload. This can be achieved using automatic systems with endoscopic and histological images. Recently, the success of deep learning has motivated the development of image- and video-based polyp identification and segmentation. Currently, most diagnostic colonoscopy rooms utilize artificial intelligence methods that are considered to perform well in predicting invasive cancer. Convolutional neural network-based architectures, together with image patches and preprocesses are often widely used. Furthermore, learning transfer and end-to-end learning techniques have been adopted for detection and localization tasks, which improve accuracy and reduce user dependence with limited datasets. However, explainable deep networks that provide transparency, interpretability, reliability, and fairness in clinical diagnostics are preferred. In this review, we summarize the latest advances in such models, with or without transparency, for the prediction of colorectal cancer and also address the knowledge gap in the upcoming technology
Hepatoprotective Potential of Malaysian Medicinal Plants: A Review on Phytochemicals, Oxidative Stress, and Antioxidant Mechanisms
Hepatotoxicity is a major global public health concern. Despite advances in modern medicine, the demerits of chemically prepared drugs outweigh their merits. In addition, the treatment of liver diseases based on modern medical principles has been found to produce several undesired side effects. Therefore, the exploration of medicinal plants has gained worldwide attention for treating various diseases, including liver diseases, owing to their potential efficacy and cost effectiveness. Several plants, including Andrographis paniculata, Bauhinia purpurea, Commelina nudiflora, Dillenia suffruticosa, Elaeis guineensis, Lygodium microphyllum, and Nephrolepis biserrata, have been reported with hepatoprotection. Moreover, these plants have been shown to play a vital role in ameliorating cellular damage because they contain several phytochemicals, including alkaloids, saponins, flavonoids, tannins, terpenoids, steroids, polyphenols, and diterpenoid lactones. The following antioxidant, anti-inflammatory, immunomodulatory, and hepatoprotective compounds have been found in these plants: andrographolide, rosmarinic acid, phenol, eugenol, 9,12-octadecadienoic, n-hexadecanoic acid, dihydroxy dimethoxy flavone, sitosterol, demethoxycurcumin, quercetin, linoleic acid, stigmasterol, kojic acid, indole-2-one, α-terpinol, linalool, kaempferol, catechin, ellagic acid, and oleanolic acid. This paper aimed to provide an in-depth review of in vivo studies on Malaysian medicinal plants possessing hepatoprotective properties, phytochemical ingredients, and antioxidant mechanisms, with an emphasis on the species proven particularly useful for treating hepatic disorders
Preparation and optimization of macroalgae-derived solid acid catalysts
Solid acid catalysts were synthesized from macroalgae Sargassum horneri via hydrothermal carbonization followed by sulfuric acid sulfonation. A three-variable Box-Behnken design and optimization was used to maximize surface acidity. The optimal preparation conditions were found to be at the carbonization temperature of 217 °C, the carbonization time of 4.6 h and the sulfonation temperature of 108.5 °C. Under these conditions, the highest surface acidity achieved was 1.62 mmol g−1. Physical and chemical properties of prepared solid acid catalyst were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, and elemental analysis. The results proved the grafting of –SO3H groups on an amorphous carbon structure. The catalyst activity was evaluated by the esterification of oleic acid with methanol. The sample prepared achieved 96.6% esterification yield, which was higher than the 86.7% yield achieved by commercial Ambersyst-15 under the same reaction conditions
Dental caries in primary and permanent teeth in children's worldwide, 1995 to 2019: a systematic review and meta-analysis
Background: Early childhood caries (ECC) is a type of dental caries in the teeth of infants and children that is represented as one of the most prevalent dental problems in this period. Various studies have reported different types of prevalence of dental caries in primary and permanent teeth in children worldwide. However, there has been no comprehensive study to summarize the results of these studies in general, so this study aimed to determine the prevalence of dental caries in primary and permanent teeth in children in different continents of the world during a systematic review and meta-analysis. Methods: In this review study, articles were extracted by searching in the national and international databases of SID, MagIran, IranMedex, IranDoc, Cochrane, Embase, ScienceDirect, Scopus, PubMed, and Web of Science (ISI) between 1995 and December 2019. Random effects model was used for analysis and heterogeneity of studies was evaluated by using the I2 index. Data were analyzed by using the Comprehensive Meta-Analysis (Version 2) software. Findings: In this study, a total of 164 articles (81 articles on the prevalence of dental caries in primary teeth and 83 articles on the prevalence of dental caries in permanent teeth) were entered the meta-analysis. The prevalence of dental caries in primary teeth in children in the world with a sample size of 80,405 was 46.2% (95% CI: 41.6–50.8%), and the prevalence of dental caries in permanent teeth in children in the world with a sample size of 1,454,871 was 53.8% (95% CI: 50–57.5%). Regarding the heterogeneity on the basis of meta-regression analysis, there was a significant difference in the prevalence of dental caries in primary and permanent teeth in children in different continents of the world. With increasing the sample size and the year of study, dental caries in primary teeth increased and in permanent teeth decreased. Conclusion: The results of this study showed that the prevalence of primary and permanent dental caries in children in the world was found to be high. Therefore, appropriate strategies should be implemented to improve the aforementioned situation and to troubleshoot and monitor at all levels by providing feedback to hospitals
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