In this paper, the impact of atmospheric stability on a wind turbine wake is studied experimentally and numerically. The experimental approach is based on full-scale (nacelle based) pulsed lidar measurements of the wake flow field of a stall-regulated 500 kW turbine at the DTU Wind Energy, Risø campus test site. Wake measurements are averaged within a mean wind speed bin of 1 m s 1 and classified according to atmospheric stability using three different metrics: the Obukhov length, the Bulk-Richardson number and the Froude number. Three test cases are subsequently defined covering various atmospheric conditions. Simulations are carried out using large eddy simulation and actuator disk rotor modeling. The turbulence properties of the incoming wind are adapted to the thermal stratification using a newly developed spectral tensor model that includes buoyancy effects. Discrepancies are discussed, as basis for future model development and improvement. Finally, the impact of atmospheric stability on large-scale and small-scale wake flow characteristics is presently investigated.

Introduction: Inflammatory myofibroblastic tumor (IMT), a locally aggressive neoplasm capable of metastasis, may show an IgG4-rich lymphoplasmacytic infiltrate. Prior reports suggest that storiform-fibrosis and obliterative phlebitis aid in the distinction of IMT from IgG4-related diseases. Herein, we highlight the morphologic overlap between the two diseases, and emphasize the importance of a multiplex fusion assay in the distinction of IgG4-RD from IMT. Methods: We identified 7 IMTs with morphologic and immunohistochemical features of IgG4-RD; 3 patients were originally diagnosed with IgG4-RD. Demographic, clinical and morphologic data was recorded. We also re-evaluated 56 patients with IgG4-RD. We performed immunohistochemistry for IgG4, IgG, ALK and ROS1. In situ hybridization for IgG4 and IgG was performed in selected cases. A multiplex next-generation sequencing (NGS) based RNA assay for gene fusions was performed to detect all known IMT-related gene fusions. Results: All 7 IMTs showed a dense lymphoplasmacytic infiltrate and storiform-type fibrosis, with obliterative phlebitis noted in 3 cases. The neoplastic stromal cells constituted <5% of overall cellularity and stromal atypia was either absent or focal and mild. Elevated numbers of IgG4 positive cells and increased IgG4 to IgG ratio was identified in all cases. Four cases showed ALK related abnormalities; while two patients showed ROS1 and NTRK3 fusions. One tumor was negative for known IMT-related gene fusions. All 56 IgG4-RD cases were negative for ALK and ROS1 on immunohistochemistry; 6 cases were negative on the fusion assay. Conclusion: Highly-inflamed IMTs are indistinguishable from IgG4-RD both histologically and on immunohistochemistry for IgG4. We advocate scrutinizing patients with presumptive single organ IgG4-RD for IMT and the diagnostic algorithm should include ALK and ROS1 immunohistochemistry and, in selected cases, a NGS-based fusion assay that covers known IMTassociated gene fusions.

The evolving classification of round cell sarcomas is driven by molecular alterations. EWSR1-PATZ1 fusion positive spindle and round cell sarcoma is one such new tumor entity. Herein, we report two EWSR1-PATZ1 fusion positive spindle and round cell sarcomas with overlapping histological features and polyphenotypic differentiation. The intraabdominal tumors affected female patients, 31 and 53-year-old. Both tumors showed sheets and nests of round to spindle cells, fine chromatin, tiny conspicuous nucleoli, moderate cytoplasm and thick bands of intratumoral fibrosis. On immunohistochemistry, both tumors showed positivity for CD99, desmin, myogenin, myoD1, S100, Sox10, CD34 and GFAP and were negative for keratin. Fluorescence insitu hybridization revealed rearrangement at EWSR1 locus. Next generation sequencing based RNA fusion assay revealed EWSR1-PATZ1 fusion in both cases. EWSR1-PATZ1 fusion positive spindle and round cell sarcomas show abundant intratumoral fibrosis and polyphenotypic differentiation, thus mimicking a range of tumors including desmoplastic small round cell tumor. The precise classification of this spindle and round cell sarcoma and its relationship to the Ewing sarcoma family of tumors remains to be determined.

A spectral tensor model is presented for turbulent fluctuations of wind velocity components and temperature, assuming uniform vertical gradients in mean temperature and mean wind speed. The model is built upon rapid distortion theory (RDT) following studies by Mann and by Hanazaki and Hunt, using the eddy lifetime parameterization of Mann to make the model stationary. The buoyant spectral tensor model is driven via five parameters: the viscous dissipation rate «, length scale of energy-containing eddies L, a turbulence anisotropy parameter G, gradient Richardson number (Ri) representing the local atmospheric stability, and the rate of destruction of temperature variance h u . Model output includes velocity and temperature spectra and associated cospectra, including those of longitudinal and vertical temperature fluxes. The model also produces two-point statistics, such as coherences and phases of velocity components and temperature. The statistics of uniformly sheared and stratified turbulence from the model are compared with atmospheric observations taken from the Horizontal Array Turbulence Study (HATS) field program, and model results fit observed one-dimensional spectra quite well. For highly unstable stratification, however, the model has deficiencies at low wavenumbers that limit its prediction of longitudinal velocity component spectra at scales on the order of 0.6 km. The model predicts coherences well for horizontal separations but overestimates vertical coherence with increasing separation. Finally, it is shown that the RDT output can deviate from Monin-Obukhov similarity theory.

Granulomatous rosacea (GR) and lupus miliaris disseminatus faciei (LMDF) are 2 forms of facial granulomatous diseases. Although they show some morphological overlap, they have distinct clinical presentation. This study was performed to demonstrate the clinical and histological features of GR and LMDF and to establish their relationship to tuberculous etiology by molecular technique. All the cases of GR (n = 20) and LMDF (n = 10) diagnosed on skin biopsy over the past 6 years were reviewed along with their clinical detail. Polymerase chain reaction (PCR) was performed using primers specific for Mycobacterium tuberculosis. The mean age of patients with GR was 45 years 10 months (range 18-75 years) as compared to 33 years 5 months (range 18-57 years) in patients with LMDF. The GR cases comprised 13 men and 7 women patients, whereas all 10 LMDF cases were seen in men. GR cases had papular lesion over an erythematous base on face, whereas LMDF cases had papular/nodular/nodulocystic lesions on the face and neck. Histologically, GR cases showed small granulomas without necrosis in a background of variable lymphoid infiltrate and dilated capillaries, whereas LMDF showed large granulomas with caseous necrosis and minimal inflammation. Five cases (25%) of GR showed degenerating Demodex folliculorum mites. No case of GR or LMDF showed positivity for mycobacterial polymerase chain reaction. Despite some similarities, GR and LMDF show distinct clinical and histological features. Thus, LMDF is a distinct clinicopathological entity separate from the GR, with different etiopathogenesis. However, none of the conditions are related to a tuberculous etiology.

Many reports have not specifically mentioned the full histopathological findings of IgG4-related IPTs that may hinder in refining the diagnostic criteria of IgG4RD. The IgG4-related IPTs diagnosed on biopsies with requisite features showed prompt response to steroids indicating specificity of histopathological findings in predicting treatment response.

A velocity spectral tensor model was evaluated from the single-point measurements of wind speed. The model contains three parameters representing the dissipation rate of specific turbulent kinetic energy, a turbulence length scale and the turbulence anisotropy. Sonic anemometer measurements taken over a forested and an agricultural landscape were used to calculate the model parameters for neutral, slightly stable and slightly unstable atmospheric conditions for a selected wind speed interval. The dissipation rate above the forest was nine times that at the agricultural site. No significant differences were observed in the turbulence length scales between the forested and agricultural areas. Only a small difference was observed in the turbulence anisotropy at the two sites, except near the surface, where the forest turbulence was more isotropic. The turbulence anisotropy remained more or less constant with height at the forest site, whereas the turbulence became more isotropic with height for the agricultural site. Using the three parameters as inputs, we quantified the performance of the model in coherence predictions for vertical separations. The model coherence of all the three velocity components was overestimated for the analyzed stability classes at both sites. As expected from the model approximations, the model performed better at both sites for neutral stability than slightly stable and unstable conditions. The model prediction of coherence of the along-wind and vertical components was better than that of the cross-wind component. No significant difference was found between the performance of the model at the forested and the agricultural areas.

A spectral-tensor model of non-neutral, atmospheric-boundary-layer turbulence is evaluated using Eulerian statistics from single-point measurements of the wind speed and temperature at heights up to 100 m, assuming constant vertical gradients of mean wind speed and temperature. The model has been previously described in terms of the dissipation rate , the length scale of energy-containing eddies L, a turbulence anisotropy parameter Γ , the Richardson number Ri, and the normalized rate of destruction of temperature variance η θ ≡ θ / . Here, the latter two parameters are collapsed into a single atmospheric stability parameter z/L using Monin-Obukhov similarity theory, where z is the height above the Earth's surface, and L is the Obukhov length corresponding to {Ri, η θ }. Model outputs of the one-dimensional velocity spectra, as well as cospectra of the streamwise and/or vertical velocity components, and/or temperature, and cross-spectra for the spatial separation of all three velocity components and temperature, are compared with measurements. As a function of the four model parameters, spectra and cospectra are reproduced quite well, but horizontal temperature fluxes are slightly underestimated in stable conditions. In moderately unstable stratification, our model reproduces spectra only up to a scale ∼ 1 km. The model also overestimates coherences for vertical separations, but is less severe in unstable than in stable cases.