•Properties of HVF-SCC predicted from VVF-SCC data by using SVM method.•Appropriate inputs was used and kernel coefficients calculated by grid search.•New models were compared by previous methods and ...validated by experimental results.
Support vector machines (SVMs) have recently been used to model the properties of low volume fly ash self-compacting concrete (LVF-SCC) by means of kernel functions to minimize the experimental work. Appropriate linear and non-linear SVM models with different kernels (linear, polynomial, radial basis and sigmoid) were proposed in this paper to predict the fresh properties and compressive strength of high volume fly ash SCC (HVF-SCC) from various volume fly ash SCC (VVF-SCC). Since most available data contain relative low volume fly ash, new SVM models were trained on VVF-SCC mixture proportions adapted from literature, and the prediction results were compared to those of previous models for HVF-SCC and LVF-SCC. Moreover, an experimental plan containing six different SCC mixtures was established and the proposed SVM models were validated by experimental results, including compressive strength, L-box, slump, U-box, and V-funnel. Results showed that new SVM models provide better outcomes if considering appropriate input vector and wide range data to obtain the proper kernel function coefficient to predict the various properties of HVF-SCC. Among the kernel functions, prediction results of the SVM – RBF model were more accurate compared to other kernels.
This research was based on a finite-element model (FEM) of large foundations such as induced draft (ID) fans. Three-dimensional (3D) linear analyses were performed under arbitrary static and dynamic ...loads for various modulus of elasticity of concrete (Ec) (20, 25, 28 and 30 GPa) and reinforcement (Es) (200, 250, 300 GPa). FEM results were compared with the existing ID fan foundations (laboratory-based evidence) to assess the accuracy of simulations made by the FEM. This study validated what constitutes a major departure from current thinking regarding material properties modeling of concrete under various loads to increase foundation for lifetime.
Foundation analyzing of centrifugal ID fans in cement plants Eskandari, Hamid; Gharouni Nik, Morteza; Pakzad, Amir
Alexandria Engineering Journal /Alexandria Engineering Journal,
June 2016, 2016-06-00, Letnik:
55, Številka:
2
Journal Article
Recenzirano
Odprti dostop
This research was based on a finite-element model (FEM) of large foundations such as induced draft (ID) fans. Three-dimensional (3D) linear analyses were performed under arbitrary static and dynamic ...loads for various modulus of elasticity of concrete (Ec) (20, 25, 28 and 30GPa) and reinforcement (Es) (200, 250, 300GPa). FEM results were compared with the existing ID fan foundations (laboratory-based evidence) to assess the accuracy of simulations made by the FEM. This study validated what constitutes a major departure from current thinking regarding material properties modeling of concrete under various loads to increase foundation for lifetime.
The objective of this study was to investigate the effect of the systemic administration of metronidazole and amoxicillin as an adjunct to initial periodontal therapy in patients with moderate to ...severe chronic periodontitis.
This randomized, double blind, placebo controlled parallel study involved 50 adult patients with untreated periodontitis who were randomly assigned to receive either a full-mouth scaling and root planing along with systemic metronidazole and amoxicillin (T group) or scaling and root planing with a placebo (P group). Clinical measurements including probing depth (PD), clinical attachment levels (CAL), Plaque Index (PI), and Bleeding Index (BI) were recorded at baseline and six to eight weeks after therapy. The deepest pocket was selected and samples for microbiological testing were taken. Patients received coded study medications of either 500 mg amoxicillin in combination with 250 mg metronidazole or an identical placebo every eight hours for seven days following scaling and root planing.
There was a significant change in PD (P=0.0001), CAL (P=0.00001), PI (P<0.05), and BI (P<0.05) in the T group compared to the placebo group after therapy. Parallel to the clinical changes, treatment significantly reduced the number of Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and P. intermedia (Pi) compared with baseline in the T group (P=0.003, 0.021 and 0.0001, respectively). However, in the P group only the Pi colony count was reduced significantly (P=0.0001). After therapy, there was a significant difference between the T and P groups in the number of patients negative for Aa, Pg, and Pi (Pv = 0.033).
The significant differences between treatment and placebo groups are in line with other studies and support the considerable adjunctive benefits of the combination of amoxicillin and metronidazole in the treatment of chronic periodontitis.
AIM: To study the combinative effects of nanocerium and selenium in a murine model of diabetes. METHODS: Cerium oxide (CeO2) nanoparticles (60 mg/kg per day) and sodium selenite (5 μmol/kg per day) ...aloneor in combination, or the metal form of CeO2 (60 mg/kg) were administered for 2 wk by intraperitoneal injection to streptozotocin-induced diabetic rats. At the end of treatment blood was collected, liver tissue dissected and then oxidative stress markers, extent of energy depletion and lipid prof ile were evaluated.RESULTS: Antioxidant enzymes and high density lipoprotein decreased whereas oxidative stress, adenosine diphosphate/adenosine triphospahte levels, cholesterol, triglyceride and low density lipoprotein increased on induction of diabetes. All were improved by a combination of nanocerium and sodium selenite. There was a relative amelioration by CeO2 nanoparticles or sodium selenite alone, but the metal form of CeO2 showed no signif icant improvement. CONCLUSION: The combination of nanocerium and sodium selenite is more effective than either alone in improving diabetes-induced oxidative stress.
The demand for lithium has increased incredibly during the last decade as it has become the mainstream for the growth of industrial products; especially batteries for electric vehicles and electronic ...devices. Given the high demand for lithium, researchers are focusing on methods for extracting lithium from a variety of sources. Among different liquid lithium extraction methods, lithium ion-sieve technology (LIS) is an emerging recovery method with great advantages over other approaches. LIS adsorption is a promising method for Li extraction owing to its low energy consumption, high lithium uptake capacity, environmentally friendly nature and superior lithium selectivity properties. A variety of physical and chemical methods can be applied to extract lithium from brines and ores. The present work critically reviews recent developments in lithium extraction and recovery using LIS adsorbents and membranes from aqueous solutions such as brine, seawater, etc. The paper has been particularly categorized based on the structure of the adsorbents and the pros and cons of various LIS adsorbents. Furthermore, this work emphasizes recent achievements with regard to the stability challenges encountered with LIS adsorbents. The favorable progress along with comparable advantageous such as higher lithium selectivity, lower environmental challenges, and higher energy efficiency have made LIS one of the most promising methods for lithium extraction from aqueous media.
•This work provides an overview of lithium ion sieve technologies.•The focus of this work is on the materials that have been used to selectively recover Li.•Titanium and manganese based lithium ion sieves were comprehensively studied.•Challenges and future outlook of the membranes were also presented.
The ongoing pandemic of Coronavirus disease 2019 (COVID-19) has infected more than 27 million confirmed cases and 8,90,000 deaths all around the world. Verity of viral infections can infect the ...nervous system; these viral infections can present a wide range of manifestation. The aim of the current study was to systematically review the COVID-19 associated central nervous system manifestations, mental and neurological symptoms. For that we conducted a comprehensive systematic literature review of four online databases, including Web of Science, PubMed, Scopus and Embase. All relevant articles that reported psychiatric/psychological symptoms or disorders in COVID-19 without considering time and language restrictions were assessed. All the study procedures were performed based on the PRISMA criteria. Due to the screening, 14 studies were included. The current study result indicated that, the pooled prevalence of CNS or mental associated disorders with 95% CI was 50.68% (6.68-93.88). The most prevalence symptoms were hyposmia/anosmia/olfactory dysfunction (number of study: 10) with 36.20% (14.99-60.51). Only one study reported numbness/paresthesia and dysphonia. Pooled prevalence of numbness/paresthesia and dysphonia was 5.83% (2.17-12.25) and 2.39% (10.75-14.22). The pooled prevalence of depression and anxiety was 3.52% (2.62-4.54) and 13.92% (9.44-19.08). Our findings demonstrate that COVID-19 has a certain relation with neurological symptoms. The hypsomia, anosmia or olfactory dysfunction was most frequent symptom. Other symptoms were headache or dizziness, dysgeusia or ageusia, dysphonia and fatigue. Depression, anxiety, and confusion were less frequent symptoms.
Wetlands are one of the most important aquatic ecosystems that are vulnerable to various factors, including human activity or natural events such as drought. Remote sensing technology is an effective ...technique for managing and monitoring changes in these ecosystems caused by natural events and human activities. The present study evaluated the effects of changes at Bakhtegan Lake on six climatic parameters in its surrounding environments. Landsat satellite imagery was used to monitor changes in the Bakhtegan Lake surface during times of maximum extent in the period from 2000 to 2015. Support vector machine (SVM) classification was applied to extract the characteristics of the lake surface. Then, the distance of 80 km from the lakeshore was identified as the environment of its influence on the surrounding land, which was divided into three buffers from 0 to 25, 26–55 and 56–80 km. The results showed that a higher accuracy than the index for extracting lake area was achieved using the SVM classification method. Additionally, the climate parameters of mean annual precipitation, relative humidity, and percentage of cloud cover significantly influenced (0.001) lake surface changes in buffer one, indicating the highest impact among all climatic parameters. In buffer two, the significance level of the precipitation parameter decreased to about 0.05, and the annual mean minimum temperature was significantly lower (0.05); however, the mean annual minimum and maximum temperatures were not significant
Estimating the current global prevalence of metabolic syndrome (MetS), and its components, among rheumatoid arthritis (RA) patients is necessary in order to formulate preventative strategies and to ...ensure there are adequate community resources available for these patients. Furthermore, the association between RA and MetS is controversial and has not previously been comprehensively assessed. Therefore, the present study aimed to: 1) determine the prevalence of MetS, and its components, among RA patients across the world 2) update the odds ratio of MetS in RA patients, compared to healthy controls, using a comprehensive systematic review and meta-analysis.
International databases, including: the Web of Science, PubMed, Scopus, Embase, CINAHL and other relevant databases were searched to identify English language articles which reported the prevalence and risk of MetS in RA patients between January 2000 and August 2016. The meta-analysis only included studies which clearly described the time and location of the study, utilised adequate sampling strategies, and appropriate statistical analyses.
The meta-analyses of prevalence (70 studies n = 12612) and risk (43 studies n = 35220) of MetS in RA patients were undertaken separately. The overall pooled prevalence of MetS was 30.65% (95% CI: 27.87-33.43), but this varied from 14.32% (95% CI: 10.59-18.05) to 37.83% (95% CI: 31.05-44.61), based upon the diagnostic criteria used. The prevalence of MetS also varied slightly between males (31.94%, 95% CI: 24.37-39.51) and females (33.03%, 95% CI: 28.09-37.97), but this was not statistically significant. The overall pooled odds ratio (OR) of MetS in RA patients, compared to healthy controls, was 1.44 (95% CI: 1.20-1.74), but this ranged from 0.70 (95% CI: 0.27-1.76) to 4.09 (95% CI: 2.03-8.25), depending on the criteria used. The mean age and diagnostic criteria of MetS were identified as sources of heterogeneity in the estimated odds ratios between studies (P<0.05).
According to the high prevalence of MetS in RA patients, and high risk of MetS, measuring metabolic syndrome in RA patients is strongly recommended. Furthermore, as high waist circumference (WC) is the most common metabolic syndrome component, more attention must be paid to nutrition and weight loss among those with RA.
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