72 research outputs found
A new framework for resolving conflicts over transboundary rivers using bankruptcy methods
Get PDFA novel bankruptcy approach is proposed for resolving transboundary river conflicts in which the total water demand or claim of the riparian parties is more than the available water. Bankruptcy solution methods can allocate the available water to the conflicting parties with respect to their claims. Four commonly used bankruptcy methods in the economic literature are used here to develop new river bankruptcy solution methods for allocating water to the riparian parties of river systems. Given the non-uniform spatial and temporal distribution of water across river basins, the proposed solution methods are formulated as non-linear network flow optimization models to allocate water with respect to time sensitivity of water deliveries at different locations in a river network during the planning horizon. Once allocation optimization solutions are developed, their acceptability and stability must be evaluated. Thus, a new bankruptcy allocation stability index (BASI) is developed for evaluating the acceptability of river bankruptcy solutions. To show how the proposed river bankruptcy framework can be helpful in practice, the suggested methods are applied to a real-world transboundary river system with eight riparians under various hydrologic regimes. Stability analysis based on the proposed stability evaluation method suggests that the acceptability of allocation rules is sensitive to hydrologic conditions and demand values. This finding has an important policy implication suggesting that fixed allocation rules and treaties may not be reliable for securing cooperation over transboundary water resources as they are vulnerable to changing socioeconomic and climatic conditions as well as hydrologic non-stationarity
The effect of L-arginine supplementation on obesity-related indices: A systematic review and meta-analysis of randomized clinical trials
Get PDFThe clinical studies regarding the effect of L-arginine in human anthropometry have not been fully consistent, therefore, we carried out a systematic review and meta-analysis of randomized clinical trials in order to precisely evaluate and quantify the efficacy of L-arginine on weight, waist circumference, and BMI. We searched online databases including PubMed, SCOPUS, and Google Scholar for relevant articles up to September 2017. Eligible articles were reviewed by two independent investigators. Mean differences of the outcomes were used for calculation of weighted mean difference (WMD) derived from the random-effects model. Statistical heterogeneity between studies was examined using Cochran's Q-test and I2index. Funnel plot and Egger's tests were performed to assess the publication bias. In our initial search, we found 1598 publications, of which 8 RCTs (9 treatment arms) were included. The results of the meta-analysis displayed a significant reduction in WC following L-arginine supplementation (WMD: -2.97 cm; 95 CI: -4.75 to -1.18, P = 0.001). However, L-arginine intervention had not elicited a significant effect on BMI (WMD: -0.51 kg/m2; 95 CI: -1.11 to .08, P = 0.09) and body weight (WMD: -0.57 kg; 95 CI: -1.77 to 0.61, P = 0.34). Subgroup analyses displayed that longer-term interventions (�8 weeks) had a positive effect on body weight and using < 8 g/day L-arginine with longer duration (�8 weeks) could significantly decrease BMI. In conclusion, this meta-analysis result suggested L-arginine supplementation could reduce waist circumference without any significant effect on body weight and body mass index. © 2021 Hogrefe Verlag GmbH & Co. KG. All rights reserved
STUDY OF SEISMIC BEHAVIOR OF COLD-FORMED STEEL FRAMES SHEATHED BY FIBER CEMENT BOARDS
No full textIn recent times, the use of cold formed steel (CFS) structures in housing industry has increased worldwide due to its great advantages, such as their light weight and high speed construction. In addition, the possibility of mass production and industrialization, quality control of construction and performance are other advantages of this type of structures. Although CFS walls are not new and have been used as non-structural components for many years, their application as the main load-bearing structural frames is relatively new, and as a result, appropriate guidelines that address the seismic design of CFS structures have not yet been fully developed. In addition, the lateral design of these systems is not adequately detailed in the available standards of practice. One of the currently-in-use lateral resistant systems for light steel buildings is steel shear walls sheathed by fiber cement boards (FCB). Fiber cement board sheathed panel lateral resistant system is already being used in housing industry though there are very few studies on the structural performance of these systems. In this paper, the seismic behavior of shear cold formed steel walls sheathed by fiber-cement board panels is investigated. For this purpose, finite element nonlinear analysis is employed using ANSYS software. The impact of some structural characteristics on the behavior of frames, including geometric imperfections and residual stresses are also studied. In addition, the ratios of height to width, studs thickness, fiber cement boards thickness, and studs spacing are investigated. Of particular interest are the specimens' maximum lateral load capacity and deformation behavior as well as a rational estimation of the seismic response modification factor. The study also looks at the failure modes of the system and investigates the main factors contributing to the ductile response of the CFS walls. A discussion on the calculated response factors in comparison to those prescribed in the relevant codes of practice is also presented
A Novel Compact Dual Notch Band Filter Based on Metamaterial Concept
No full textUsing composite right-left handed (CRLH) transmission line concept, a novel miniaturized dual notch band filter (DNBF) is proposed. The suggested DNBF consists of an interdigital transmission line (ITL), split ring resonators (SRRs) and complementary split ring resonators (CSRRs). Since the resonance frequency of the SRRs and CSRRs are quite independent of each other, the dual notch bands of the proposed filter can be separately controlled and shifted by changing the dimension of the SRRs and CSRRs. In this paper, the reject bands are designed for WLAN (2.4 GHz) and WiMAX (3.5 GHz) to reject these frequency bands from the ultra-wide band communication systems. The simulation results show that the transmission response has more than 32 dB rejections near each band. To validate the design concept, the proposed NBPF has been fabricated and tested. Experimental verification is provided and good agreement has been found between simulation and measurement. To the best of our knowledge, the proposed NBPF is more compact in comparison with other reported filters
Osteoid Osteoma of Elbow: Two Case Reports and Review of Literature
No full textAlthough osteoid osteoma is a relatively common lesion, it rarely occurs at elbow. We report two cases of osteoid osteoma of elbow in trochlea. Diagnosis was delayed because of non-specific clinical and radiological features. The two patients suffered from flexion contracture of elbow due to synovitis, while at the same time, pronation and supination remained normal. Only one of the patients complained of specific nocturnal pain. Both patients had latencies between the onset of symptoms and the appearance of radiological signs. Open surgical excision of the nidus resulted in complete relief and motion recovery in both cases. Diagnostic difficulties and treatment options are discussed below. Key words: Osteoid osteoma, Elbow, Trochle
Estimation of the Best Classification Algorithm and Fraud Detection of Olive Oil by Olfaction Machine
No full textIntroductionExtra Virgin Olive Oil (EVOO) is one of the most common and popular edible oils which is an important part of the Mediterranean diet. It is a rich source of sterol, phenol compounds and vitamins A and E. EVOO has useful effects on human body and significant reduction of cardiovascular diseases due to these benefits, EVOO is expensive so unfortunately adulteration in EVOO by mixing it with other cheap and low cost and low value oils such as canola, sunflower, palm and etc. is very common. Adulteration leads to health and financial losses and sometimes cause serious illness. Olive oil has various quality levels which depend on different factors such as olive cultivar, storage, oil extracting process etc.Materials and MethodsThere are numerous food quality evaluation and adulteration detection approaches which include destructive and non-destructive methods. Control sample (EVOO) was applied from "DANZEH food industry", Lowshan, Gilan Province. For ensuring that control sample is extra virgin, a sample was tested in "Rahpooyan e danesh koolak Lab." Tehran, Iran; according to "Institute of standards and industrial research of Iran" ISIRI number: 4091 and INSO 13126-2. Eight semi-conductor gas sensors "FIS, MQ3, MQ3, MQ4, MQ8, MQ135, MQ136, TGS136, TGS813 AND TGS822" applied in used olfaction machine. In this study there were 6 treatments: 1- Pure EVOO, 2- EVOO with 5% adulteration, 3- EVOO with 10% adulteration, 4- EVOO with 20% adulteration, 5- EVOO with 35% adulteration and 6- EVOO with 50% adulteration. Adulteration created with ordinary frying oil (including sunflower, canola, and maize oils). Each treatment prepared in seven samples and each sample test was repeated seven times. In this study, olfaction machine, a non-destructive, simple and user friendly System applied. As mentioned, the olfaction machine includes eight different sensors, so each test has eight graphs. Four features (1- Sensor output (mV) in start of odor pulse (refer to fig. 3) 2- Sensor output at the end of odor pulse 3- Average of sensor output during odor pulse and 4- Difference of sensor output at the end and start of start of odor pulse); So 32 features extracted and analyzed and finally effective sensors reported.Results and DiscussionHistogram and box plot of raw data showed that the data are not normal and need some preprocessing operations. Preprocessing facilitates data analyzing and classifying extracted features. After preprocessing, the standard data, divided into two classes: train data (70%) and test data (30%). Data classified with 4 different classifier models which include: K-nearest neighbors, support vector machine, artificial neural network and Ada-boost. Results showed that KNN method, with 89.89% and SVM with 86.52% classified with higher accuracy. Similarly, the confusion matrix showed the reasonable results of classifying operation. Also, three effective sensors in classifying determined TGS2620, MQ5 and MQ4 respectively, and on the other side, sensors such as MQ3 and MQ8 have the minimum effect on classifying so it is possible to remove these sensors from the sensor array without effective impress on results. This may cause decrease in the olfaction machine price and reduce analyzing time.ConclusionsDue to increasing adulteration in foods, especially in olive oil and its significant effects on people's health and financial losses, a simple, cheap and non-destructive quality evaluation extended. Results showed that the olfaction machine with metal oxide semiconductor (especially including TGS 2620, MQ5 and MQ4 sensors) can use for classification and adulteration detection of extra virgin olive oil. Evaluation of this system's output leads to higher classification accuracy by using KNN and SVM method for olive oil classification and also fraud detection (5% adulteration)
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