Analyses of Wave Scattering and Absorption Produced by WEC Arrays: Physical/Numerical Experiments and Model Assessment

2017 ◽  
pp. 71-97 ◽  
Author(s):  
H. Tuba Özkan-Haller ◽  
Merrick C. Haller ◽  
J. Cameron McNatt ◽  
Aaron Porter ◽  
Pukha Lenee-Bluhm
Keyword(s):  
Wave Scattering ◽  
Numerical Experiments ◽  
Model Assessment

scholarly journals Fluid-structure coupled wave scattering in a flexible duct at the junction of planar discontinuities

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771318 ◽  
Author(s):  
Rab Nawaz ◽  
Aasim Ullah Jan ◽  
Muhammad Afzal
Keyword(s):  
Wave Scattering ◽  
Numerical Experiments ◽  
Normal Modes ◽  
Acoustic Scattering ◽  
Algebraic Equations ◽  
Linear Algebraic Equations ◽  
Matching Technique ◽  
Generalized Orthogonal ◽  
Bounding Surfaces ◽  
Infinite Linear

This article applies the mode-matching technique to discuss acoustic scattering of waves in flexible duct/channel at the junction of planar discontinuities. Fields across the junction are expanded in normal modes that involve discontinuities in velocities at the flanged junction. The reflected and transmitted fields are matched at interface wherein the use of generalized orthogonal properties (in case of flexible bounded ducts) enables the mode coefficients in terms of system of infinite linear algebraic equations. This system is truncated and solved numerically. The numerical experiments show that the variation of structural discontinuities along with different bounding surfaces significantly alters the reflected and transmitted powers.

Ultrasonic Wave Scattering by a Line Crack in a Solder Joint

1999 ◽  
Vol 11 (1) ◽  
pp. 117-135
Author(s):  
P. Dineva ◽  
D. Gross ◽  
T. Rangelov
Keyword(s):  
Solder Joint ◽  
Ultrasonic Wave ◽  
Wave Scattering ◽  
Line Crack

Therapeutic Effect of Metformin and Vitamin E Versus Prescriptive Diet in Obese Adolescents with Fatty Liver

2011 ◽  
Vol 81 (6) ◽  
pp. 398-406 ◽  
Author(s):  
Akcam ◽  
Boyaci ◽  
Pirgon ◽  
Kaya ◽  
Uysal ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Vitamin E ◽  
Fatty Liver ◽  
Liver Steatosis ◽  
Tnf Alpha ◽  
Dietary Advice ◽  
Model Assessment ◽  
Fasting Insulin ◽  
Alcoholic Fatty Liver ◽  
Obese Adolescents

Objective: The aim of the study was to determine whether metformin or vitamin E treatment for six months is effective in reducing body weight, blood pressure, and also ameliorating insulin resistance, adiponectin, and tumor necrosis factor (TNF)-alpha in obese adolescents with non-alcoholic fatty liver disease (NAFLD). Methods: Sixty-seven obese adolescents with liver steatosis (age range, 9 - 17 years) were included in the study. The metformin group received an 850-mg dose of metformin daily and the vitamin E group received 400 U vitamin E /daily, in capsule form for 6 months, plus an individually tailored diet, exercise, and behavioral therapy. Results: After 6 months later, there was a significant decline in body mass index, and fasting insulin and homeostatic model assessment (HOMA) values in all three groups. Moreover, in comparingson of changes in HOMA among the groups, the metformin- treated group showed significantly improved metabolic control and insulin sensitivity (HOMA) at the end of the study. There were no significant differences for changes of adiponectin, TNF-alpha, in all three groups after 6 months study. Conclusion: These data suggest that metformin treatment is more effective than dietary advice and vitamin E treatment in reducing insulin resistance, and also in ameliorating metabolic parameters such as fasting insulin and lipid levels, in obese adolescents having NAFLD.

Clinical factors correlated with vitamin D deficiency in patients with obesity scheduled for bariatric surgery: A single center experience

2020 ◽  
Vol 90 (3-4) ◽  
pp. 346-352
Author(s):  
Vincenzo Pilone ◽  
Salvatore Tramontano ◽  
Carmen Cutolo ◽  
Federica Marchese ◽  
Antonio Maria Pagano ◽  
...  
Keyword(s):  
Bariatric Surgery ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Serum Vitamin ◽  
Inverse Correlation ◽  
Model Assessment ◽  
Cross Sectional ◽  
Serum Vitamin D ◽  
Female Sex ◽  
Vitamin D Levels

Abstract. We aim to assess the prevalence of vitamin D deficiency (VDD) in patients scheduled for bariatric surgery (BS), and to identify factors that might be associated with VDD. We conducted a cross-sectional observational study involving all consecutive patients scheduled for BS from 2017 to 2019. The exclusion criteria were missing data for vitamin D levels, intake of vitamin D supplements in the 3 months prior to serum vitamin D determination, and renal insufficiency. A total of 206 patients (mean age and body mass index [BMI] of 34.9 ± 10.7 years, and 44.3 ± 6.99 kg/m2, respectively) met the inclusion criteria and were enrolled for data analysis. VDD (<19.9 ng/mL), severe VDD (<10 ng/mL), and vitamin D insufficiency (20–29.9 ng/mL) were present in 68.8 %, 12.5 %, and 31.2 % of patients, respectively. A significant inverse correlation was found between vitamin D levels and initial BMI, parathyroid hormone, and homeostatic model assessment of insulin resistance (r = −0.280, p < 0.05; r = −0.407, p = 0.038; r = −0.445, p = 0.005), respectively. VDD was significantly more prevalent in patients with higher BMI [−0.413 ± 0.12, CI95 % (−0.659; −0.167), p = 0.006], whereas no significant association between hypertension [−1.005 ± 1.65, CI95 % (−4.338; 2.326), p = 0.001], and diabetes type 2 (T2D) [−0.44 ± 2.20, CI95 % (−4.876; 3.986), p = 0.841] was found. We observed significant association between female sex and levels of vitamin D [6.69 ± 2.31, CI95 % (2.06; 11.33), p = 0.006]. The present study shows that in patients scheduled for BS, VDD deficiency is common and was associated with higher BMI, and female sex.

The Weight Loss Effects of Branched Chain Amino Acids and Vitamin B6: A Randomized Controlled Trial on Obese and Overweight Women

2018 ◽  
Vol 88 (1-2) ◽  
pp. 80-89 ◽  
Author(s):  
Zahra Shakibay Novin ◽  
Saeed Ghavamzadeh ◽  
Alireza Mehdizadeh
Keyword(s):  
Amino Acids ◽  
Weight Loss ◽  
Body Composition ◽  
Vitamin B6 ◽  
Controlled Trial ◽  
Density Lipoprotein ◽  
Branched Chain Amino Acids ◽  
Model Assessment ◽  
Waist To Hip Ratio ◽  
Branched Chain

Abstract. Branched chain amino acids (BCAA), with vitamin B6 have been reported to improve fat metabolism and muscle synthesis. We hypothesized that supplementation with BCAA and vitamin B6 would result in more weight loss and improve body composition and blood markers related to cardiovascular diseases. Our aim was to determine whether the mentioned supplementation would affect weight loss, body composition, and cardiovascular risk factors during weight loss intervention. To this end, we performed a placebo-controlled randomized clinical trial in 42 overweight and obese women (BMI = 25–34.9 kg/m2). Taking a four-week moderate deficit calorie diet (–500 kcal/day), participants were randomized to receive BCAA (6 g/day) with vitamin B6 (40 mg/day) or placebo. Body composition variables measured with the use of bioelectrical impedance analysis, homeostatic model assessment, and plasma insulin, Low density lipoprotein, High density lipoprotein, Total Cholesterol, Triglyceride, and fasting blood sugar were measured. The result indicated that, weight loss was not significantly affected by BCAA and vitamin B6 supplementation (–2.43 ± 1.02 kg) or placebo (–1.64 ± 1.48 kg). However, significant time × treatment interactions in waist to hip ratio (P = 0.005), left leg lean (P = 0.004) and right leg lean (P = 0.023) were observed. Overall, supplementation with BCAA and vitamin B6 could preserve legs lean and also attenuated waist to hip ratio.

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