Effet de l'angle de flèche sur le bruit à large bande de ventilateur

Cette étude vise à comprendre la mécanique de réduction de bruit afin de mitiger le bruit large bande en utilisant l’angle de flèche tout en préservant le rendement aérodynamique. Nous avons choisi des modèles et outils de calculs afin de comprendre le comportement aérodynamique ainsi que le bruit généré par l’angle de flèche. En premier lieu, une simulation Reynolds Averaged Navier Stokes (RANS) est utilisée afin d’évaluer le champ d’écoulement. Ensuite, une méthode Lattice Boltzmann (LBM) haute-fidélité est utilisée afin de prédire la radiation sonore. LBM nous permet de déterminer la source des bruits combinés. Finalement, afin de séparer le bruit large bande généré par les turbulences, nous avons adapté le modèle d’Amiet's leading-edge afin de représenter l’angle de flèche d’un ventilateur axial. Nos résultats indiquent que le dévers de pale avant surpasse le dévers de pale arrière pour la région décrochage, la radiation sonore et la consommation énergétique lorsque les performances aérodynamique est restaurée.Le bruit produit par le ventilateur de radiateur devient une préoccupation croissante. En effet, les véhicules électriques modernes ne produisent pas le bruit engendré par les groupes motopropulseurs et moteurs traditionnels. Fondé sur une revue de littérature, nous avons classé les différentes sources de bruit ainsi que leur contribution sur le spectre acoustique. Les concepts de dévers de pale avant et arrière ont démontré un potentiel avantage de réduction de bruit large bande aux détriments du rendement aérodynamique. Par conséquent, cette approche est très peu utilisée dans l'industrie. Cette étude vise à comprendre la mécanique de réduction de bruit afin de mitiger le bruit large bande en utilisant l'angle de flèche tout en préservant le rendement aérodynamique. Nous avons choisi des modèles et outils de calculs afin de comprendre le comportement aérodynamique ainsi que le bruit généré par l'angle de flèche. En premier lieu, une simulation Reynolds Averaged Navier Stokes (RANS) est utilisée afin d'évaluer le champ d'écoulement. Ensuite, une méthode Lattice Boltzmann (LBM) haute-fidélité est utilisée afin de prédire la radiation sonore. LBM nous permet de déterminer la source des bruits combinés. Finalement, afin de séparer le bruit large bande généré par les turbulences, nous avons adapté le modèle d'Amiet's leading edge afin de représenter l'angle de flèche d'un ventilateur axial. Nos résultats indiquent que le dévers de pale avant surpasse le dévers de pale arrière pour la région décrochage, la radiation sonore et la consommation énergétique lorsque les performances aérodynamique est restaurée. Nous recommandons le dévers de pale avant afin de réduire le bruit de large bande émis par le ventilateur du radiateur. Cependant, des recherches additionnelles seront nécessaires afin d'évaluer le bruit tonal. Ces recherches pourront renforcer l'utilisation de l'angle de flèche dans la conception de pales.Abstract : The radiator fan noise is becoming a growing concern since other noise sources radiated from traditional powertrains and combustion engines are omitted in modern electric vehicles. Based on a literature review, we classified the noise sources and their contribution in noise spectra. The forward sweep and backward sweep showed a strong potential in broadband noise reduction but at the cost of loss in aerodynamic efficiency. Hence, this skepticism restrained from its wide usage in fan design. Therefore, this study aims at understanding the noise reduction mechanism so that to mitigate broadband noise using blade sweep by preserving its aerodynamic performance. The various computational tools are used to investigate the aerodynamic behavior and its associated noise in swept blades. First, an industry-friendly steady Reynolds Averaged Navier Stokes (RANS) simulation technique is assessed to investigate the flow field and later a high-fidelity, unsteady Lattice Boltzmann method (LBM) is evaluated to predict the noise radiation. LBM provides the combined knowledge of all noise sources. So, finally, to segregate broadband noise generated due to turbulence interaction, we adapted Amiet's leading-edge noise prediction tool to the swept blade of an axial fan. The results indicate that forward sweep has improved pressure rise by almost 25% than backward sweep and unswept blade when designed for similar loadings. In addition, the forward sweep has reduced noise levels by 12 dB than unswept blade. We recommend using a forward sweep to reduce broadband noise emitted by the radiator fan based on our findings. However, further research is needed to investigate tonal noise that could strengthen the usage of sweep in blade design

Extranodal (cutaneous) Rosai Dorfman: a rare presentation

Rosai Dorfman disease is a rare histiocytic disorder of unknown etiology commonly involving the cervical lymph nodes first described in 1969, Extranodal involvement is very rare. Clinical course is variable

Wearable Textile Antenna for Glucose Level Monitoring

Wearable antennas are becoming increasingly popular as a result of their wide range of applications, including communication, health parameter monitoring, and so on. If the wearable antenna is built of textile material, it is highly comfortable to wear and has numerous benefits, such as light weight, compact size, and low cost. A 1.3 GHz microstrip antenna made from jeans substrate is presented in this work. For conducting patch and ground plane copper material is used. The electromagnetic properties of the jeans substrate are dielectric constant ℇr = 1.7 and loss tangent tan ẟ = 0.01. The main application of this antenna is glucose level monitoring. Three levels of glucose, i.e., hypoglycemia, hyperglycemia, and normal glucose level, are observed using this antenna. The antenna is placed over the arm in the first scenario, while the finger is placed over the antenna patch in the second case. When the glucose concentration in the blood varies, the blood properties change, and the antenna frequency shifts as a result. That frequency shift is used to find out the three glucose levels. The advantage of jeans substrate is that you can wear this antenna very easily over your arm. The antenna was designed using HFSS software and tested using an arm phantom and a finger phantom designed in HFSS.

Development and Optimization of Solid Lipid Nanoparticle for Topical Delivery

The aim of present work was to develop and evaluate solid lipid nanoparticle (SLNs) based gel for topical delivery of anti-inflammatory drug. Material and method Nabumetone loaded SLNs were developed by hot homogenization followed by ultra- sonication technique using compritol 888 ATO as solid lipid and tween 80 as a surfactant. Developed SLNs were evaluated for particle size, entrapment efficiency (EE) and drug release profile. Process and formulation parameters were optimized. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies were carried out on SLNs to mark the change in the drug and lipid modification. The Nabumetone based gels were prepared using carbopol 940 as gelling agent. Results and conclusion: The F14 batch had shown maximum entrapment efficiency up to 94.40 and sustained drug release for more than 7 hours. The particle size of optimized batch (F14) was found to be 16.54. Keywords: Solid lipid nanoparticle, Entrapment efficiency, Colloidal carrier

Trichoscopic findings in cicatricial alopecias and hair shaft disorders and its application in histopathology

Background: Many studies have been published on dermoscopy of hair and scalp disorders in the past few years, but these have been mainly carried out in western countries. Indian skin is mainly type IV and V and has its own unique set of problems and pathological findings. Hence, we conducted a study at our institute to study the dermoscopic patterns of various cicatricial alopecias.Methods: This was a descriptive study conducted in the Dermatology outpatient department, Skinaccess clinics, Nashik, between August 2014 to June 2016. The most common and characteristic feature seen in patients with cicatricial alopecia was hair follicle effacement seen in all 24 patients (100%). Hair follicle plugging was seen in 6 (25%) patients with DLE, and one patient with idiopathic scarring. Hyperkeratotic perifollicular scaling was seen in 2 patients with lichen plano pilaris. Perifollicular hyperpigmentation was seen in one patient of discoid lupus erythematosus (DLE) and 2 patients with idiopathic scarring. Hair casts were seen in 2 patients with lichen plano pilaris, and in one patient with idiopathic scarring. Patchy depigmentation was seen in 4 patients with discoid lupus erythematosus, 3 patients with idiopathic scarring, and one patient with lichen plano pilaris.Results: The most common and characteristic feature seen in patients with cicatricial alopecia was hair follicle effacement seen in all 24 patients (100%). Hair follicle plugging was seen in 6 (25%) patients with DLE, and one patient with idiopathic scarring. Hyperkeratotic perifollicular scaling was seen in 2 patients with lichen plano pilaris. Perifollicular hyperpigmentation was seen in one patient of discoid lupus erythematosus (DLE) and 2 patients with idiopathic scarring. Hair casts were seen in 2 patients with lichen plano pilaris, and in one patient with idiopathic scarring. Patchy depigmentation was seen in 4 patients with discoid lupus erythematosus, 3 patients with idiopathic scarring, and one patient with lichen plano pilaris.Conclusions: Hair follicle effacement is a characteristic dermoscopic feature of cicatricial alopecia. Hair follicle plugging, patchy depigmentation and red dots are seen in DLE. In lichen plano pilaris the dermoscopic findings of blue dots, white dots and perifollicular scaling were found to be useful for making an accurate diagnosis. Perifollicular scaling and tufting of hair is characteristically seen in patients with folliculitis decalvans. Dermoscopy is very useful in differentiating cicatricial from non-cicatricial alopecias. A biopsy obtained from the peripheral edge of the patch is more likely to show diagnostic features than the central portion. Dermoscopic guided biopsies were shown to yield definitive pathological diagnosis in 95% of the cases. Hair shaft disorders can be easily diagnosed by dermoscopy, without the need for hair

Image enhancement using fusions by Wavelet Transform, Laplacian Pyramid and combination of both.

This paper represents idea of combining multiple image modalities to provide a single, enhanced image is well established different fusion methods have been proposed in literature. This paper is based on image fusion using wavelet transform, laplacian pyramid and combination of laplacian pyramid and wavelet transform method. Images of same size are used for experimentation. Images used for the experimentation are standard images and averaging filter is used of equal weights in original images to burl. Performance of image fusion technique is measured by mean square error, normalized absolute error and peak signal to noise ratio. proposed method is compared with wavelet transform method and laplacian pyramid method, from the performance analysis it has been observed that MSE is decreased in case of all three the methods where as PSNR Increased, NAE decreased in case of laplacian pyramid and Combination of laplacian pyramid and wavelet transform where as constant for wavelet transform method

The potential of mathematical programming for the analysis of yield gaps in semi-arid tropical agriculture

The International Rice Research Institute has pioneered a methodology to identify yield gap factors and estimate their magnitudes in rice production. The total yield gap is conceptually divided into two components: Gap I, between experiment station yield and potential yield at the farm level; Gap II, between potential and actual yield at the farm level. Gap I has direct implications for research and thus for the development of new technology. Gap II deals with the realization of the production potential at the farm level with a given technology. Gap III can be further divided into two components: (1) that caused by biological constraints, and (2) that caused by socio-economic constraints. The paper proposes and demonstrates the use of a whole-farm modelling approach based on mathematical programming, to partition Yield Gap II, attributable to socio-economic factors in rainfed agriculture. The first section deals with existence of yield gaps, expressed in various ways, in different crop production activities in the study location. It also tries to explain them in terms of input gaps. In the second section, the proposed models and concepts are discussed. The third section demonstrates the use of a mathematical programming technique in breaking yield gap into components by using actual input-output data and by considering existing resource and other constraint levels.ADDITIONAL ABSTRACT:In this paper the use of whole-farm modelling based on mathematical programming to partition Yield Gap II (gap between potential and actual yield at the farm level), attributable to socioeconomic factors, in rainfed agriculture in Akola district of Maharashtra is discussed. The existence of yield gaps, expressed in various ways in different crop production activities are considered and explained in terms of input gaps. The proposed models and concepts are discussed. The use of a mathematical programming technique in breaking yield gap into components by using actual input-output data and by considering existing resource and other constraint levels, is examined. It was concluded that the use of the technique to analyse yield gaps at the farm level, rather than to analyse yield gaps of individual crops, is more appropriate in rainfed agricultur