Aerodynamic shape optimization of wind turbine blades using a Reynolds‐averaged Navier–Stokes model and an adjoint method

Computational fluid dynamics (CFD) is increasingly used to analyze wind turbines, and the next logical step is to develop CFD‐based optimization to enable further gains in performance and reduce model uncertainties. We present an aerodynamic shape optimization framework consisting of a Reynolds‐averaged Navier Stokes solver coupled to a numerical optimization algorithm, a geometry modeler, and a mesh perturbation algorithm. To efficiently handle the large number of design variables, we use a gradient‐based optimization technique together with an adjoint method for computing the gradients of the torque coefficient with respect to the design variables. To demonstrate the effectiveness of the proposed approach, we maximize the torque of the NREL VI wind turbine blade with respect to pitch, twist, and airfoil shape design variables while constraining the blade thickness. We present a series of optimization cases with increasing number of variables, both for a single wind speed and for multiple wind speeds. For the optimization at a single wind speed performed with respect to all the design variables (1 pitch, 11 twist, and 240 airfoil shape variables), the torque coefficient increased by 22.4% relative to the NREL VI design. For the multiple‐speed optimization, the torque increased by an average of 22.1%. Depending on the CFD mesh size and number of design variables, the optimization time ranges from 2 to 24h when using 256 cores, which means that wind turbine designers can use this process routinely. Copyright © 2016 John Wiley & Sons, Ltd.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136413/1/we2070_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136413/2/we2070.pd

Validation of the Knee Injury and Osteoarthritis Outcome Score (KOOS) for the treatment of focal cartilage lesions

SummaryObjectiveTo validate the Knee Injury and Osteoarthritis Outcome Score (KOOS) for the treatment of focal cartilage lesions.MethodsA total of 40 patients (mean age 35±12 years,) treated for a focal cartilage lesion in the knee were included in this study. Test–retest data were collected with an intermediate period of 2 days. Patients were asked to complete the Dutch KOOS and complementary questionnaires [short form-36 (SF-36), Lysholm, EuroQol-5D (EQ-5D)] to evaluate the clinimetric properties of the KOOS in terms of internal consistency (Cronbach's alpha), reliability [intra-class-correlation (ICC) and Bland and Altman plots], construct validity (Spearman's rank correlation), floor and ceiling effects and responsiveness.ResultsThe Cronbach's alpha of the KOOS subdomains and total score ranged from 0.74 to 0.96. The overall ICC of the KOOS was 0.97 while the subscales ranged from 0.87 to 0.95. The Bland and Altman plots showed a small individual variance between the two assessments in time. Spearman's rank correlations between the subscales of the KOOS and representative subscales of the SF-36, Lysholm and EQ-5D were high to moderate ranging from 0.43 to 0.70. We observed no floor effect while the largest observed ceiling effect was 10.3%. The responsiveness was moderate to large with the effect size ranging from 0.70 to 1.32 and the standardized response mean 0.61 to 0.87.ConclusionThis study illustrates the validity and reliability of the KOOS in measuring the clinical condition of patients after treatment of focal cartilage lesions. This study provides a basis for the use of the KOOS for future clinical research in cartilage repair

Articular Cartilage Evaluation After TruFit Plug Implantation Analyzed by Delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC)

Background: Quantitative MRI of articular cartilage has rapidly developed in recent years and provides the clinician with a noninvasive tool to determine the biological consequence of an intervention. Purpose: To evaluate the quality of intra-articular cartilage, using the dGEMRIC scanning technique, 1 year after TruFit implantation. The hypothesis was that implantation of a TruFit plug does not lead to damage at the opposing articular cartilage. Study Design: Case series; Level of evidence, 4. Methods: A total of 13 patients (age, 32 ± 8 years) were evaluated with dGEMRIC at 12 ± 4 months after treatment of an osteochondral lesion by implantation of 1 or multiple TruFit plugs. The dGEMRIC scanning protocol was applied 90 minutes after intravenous Magnevist (0.2 mmol/kg body weight) injection. Different regions of interest (ROIs) were defined: the femur cartilage, cartilage directly surrounding the implanted TruFit plug, the TruFit plug, and the articulating and nonarticulating tibia cartilage. The average dGEMRIC index (T1gd; magnetic resonance imaging relaxation time per ROI) was calculated by a pixel-by-pixel curve fitting using the Levenberg-Marquardt method. Differences between the mean T1gd of the individual ROI for all patients were tested using analysis of variance with post hoc Bonferroni correction. A P value <.05 was considered statistically significant. Results: The average T1gd of the TruFit ROI (385 ± 74 ms) was comparable with those in the femur (409 ± 49 ms) and surrounding (392 ± 64 ms) ROIs (P ≥ .339). The average T1gds for the articulating (578 ± 133 ms) and nonarticulating (516 ± 118 ms) ROIs were higher compared with the femur (409 ± 49 ms), surrounding (392 ± 64 ms), and TruFit (385 ± 74 ms) ROIs (P < .002), while no difference was observed between the tibia ROIs (P = .160). Conclusion: Implantation of the TruFit plug in osteochondral lesions does not damage the opposing or surrounding surface, and newly formed tissue inside the plug has cartilage-like dGEMRIC characteristics 12 months after implantation. The implantation of synthetic TruFit plugs is safe for the opposing cartilage, an item that is frequently discussed when using such materials to treat focal cartilage defects

Нарушение репродуктивной функции при простатите/синдроме хронической тазовой боли

Показано, что нелеченное хроническое воспаление предстательной железы приводит к нарушению показателей спермограммы и в ряде случаев к бесплодию при нормальном развитии половых желез и достаточном гормональном обеспечении организма. Бактерии, вирусы, лейкоциты, свободные радикалы, цитокины, иммунологические изменения и обструкция семявыводящих путей при простате являются кофакторами в развитии бесплодия.It is shown that untreated chronic inflammation of the prostate gland causes disturbances of spermogram count and strility in a number of cases at normal development of sex glands and sufficient hormone supply of the organism. Bacteria, viruses, leukocytes, free radicals, cytokines, immunological changes and obstruction of the deferent ducts in prostatitis are co−factors of sterility development

Design and fabrication of standardized hydroxyapatite scaffolds with a defined macro-architecture by rapid prototyping for bone-tissue-engineering research

This investigation describes the production and characterization of calcium phosphate scaffolds with defined and reproducible porous macro-architectures and their preliminary in vitro and in vivo bone-tissue-engineered response. Fugitive wax molds were designed and produced using a rapid prototyping technique. An aqueous hydroxyapatite slurry was cast in these molds. After sintering at 1250°C and then cleaning, dimensional and material characterizations of the scaffolds were performed. The resulting scaffolds represented the design, and their dimensions were remarkably consistent. A texture inherent to the layer-by-layer production of the mold was impressed onto the vertical surfaces of the scaffolds. The surface roughness (Ra) of the textured surfaces was significantly greater than that of the nontextured surfaces. Material analyses revealed a β-TCP phase in addition to hydroxyapatite for the molded ceramics. Non-molded control ceramics exhibited only hydroxyapatite. Thirty scaffolds were seeded with culture-expanded goat bone-marrow stromal cells (BMSCs) and implanted subcutaneously in nude mice for 4 or 6 weeks. Histology revealed mineralized bone formation in all the scaffolds for both implantation periods. After 4 weeks, bone was present primarily as a layer on scaffold surfaces. After 6 weeks, the surface bone formation was accompanied by bone budding from the surface and occasional bridging of pores. This budding and bridging bone formation almost always was associated with textured scaffold surfaces. However, the area percentage of bone in pores was similar for the 4- and 6-week implantation periods

Perivascular and Diffuse Lymphocytic Inflammation are not Specific for Failed Metal-on-metal Hip Implants

Several studies suggest that histologic findings from tissues obtained at revision arthroplasty for failed metal-on-metal (MOM) total hip implants may reflect an immune reaction to particles or ions in some patients. However, only a limited number of cases without MOM implants were reported as controls in those studies. The purpose of this study is to better define the extent and distribution of morphologic features attributed to an immune reaction in tissues sampled at revision surgery for failed nonMOM THA. As part of a multicenter, prospective study, we reviewed 612 capsular and interface tissues obtained from 130 patients at revision THA. The samples were selected from periacetabular regions (154 samples from 103 patients), femoral implant/cement-bone interface (154 samples from 79 patients), and from areas of the joint capsule that had an intraoperative gross appearance suggesting the possibility of either infection or metallosis (256 samples from 129 patients). All patients had more than one sample obtained. The extent and distribution of lymphocytes and plasma cells, acute inflammation, and visible particles of debris were graded using criteria similar to those described to grade inflammation around failed MOM implants. We identified perivascular lymphocytes in 111 biopsy samples taken from 65 (50%) of 130 patients, and in 87 specimens from 57 (53%) of 107 patients thought to have aseptic loosening. Diffusely distributed lymphocytes were identified in 86 (66%) of 130 patients, and in 66 (62%) of the 107 hips with aseptic loosening, although few had the highest grade of inflammation. Increasing extent of diffuse and perivascular lymphocytes correlated with increasing extent of metal particles. Mild lymphocytic inflammation, diffuse and especially perivascular, is common in tissues around failed nonMOM implants. Although extensive inflammation in an inflammatory pseudotumor pattern is rare, it does occur in some cases of failed metal-polyethylene hip arthroplasties. The importance of inflammation is unknown, but the extent of diffuse inflammation shows a positive correlation with metal debris, so it could reflect a reaction to particles or ions in some patients