81 research outputs found
Tooling for injection molding using laser-powder bed fusion.
Laser-Powder Bed Fusion (L-PBF) has been considered for some time by the injection molding industry for the fabrication of tooling for injection molding in order to address large lead times and costs for tool-making. Computer-aided simulations are also routinely used to evaluate new part and mold designs as well as understanding the effects of material compositions and processing conditions on part quality and overall productivity. However, there remains a significant need to integrate the perspectives from injection molding, 3D printing, metal powders, and component design and process simulation to better utilize LPBF for fabricating tooling required for injection molding. The present research addressed this need and built a supply-chain collaboration that used a combination of experiments and modeling to evaluate the performance of L-PBF fabricated molds as a function of machining, part design, simulation tools, material composition and conformal cooling channels. The results helped advance the understanding on the opportunities and barriers in the design and fabrication of tooling for injection molding using L-PBF
A Study on Consumer Perception Regarding Private Label Branding in India
As majority of the present day consumers are considering brand as an important element in their choice of decision while purchasing, it is very important that sellers should capitalize on the type of brand that they are offering to the consumers. Both private labels and national brands have their own advantages and disadvantages over each other mainly in terms of pricing and quality factors. But the main motive the consumers are looking forward is to buy a product which would effectively satisfy their wants and needs. If they find a product which would satisfy their needs effectively, they would buy it irrespective of whether it is a private label or a national brand. Even the price of the product may not be a major factor in such a case. The study is mainly carried out to check the preference of the customers over the usage of private labels and national branded products to satisfy their needs and requirements. The study tries to differentiate between private labels and national brands. It checks the customer preference between private labels and national brands. Keywords: Private Label Brands, National Brands, Customer Satisfactio
Conformal Tilings, Combinatorial Curvature, and the Type Problem
Roughly, a conformal tiling of a Riemann surface is a tiling where each tile
is a suitable conformal image of a Euclidean regular polygon. In 1997, Bowers
and Stephenson constructed an edge-to-edge conformal tiling of the complex
plane using conformally regular pentagons. In contrast, we show that for all , there is no edge-to-edge conformal tiling of the complex plane using
conformally regular -gons. More generally, we discuss a relationship between
the combinatorial curvature at each vertex of the conformal tiling and the
universal cover (sphere, plane, or disc) of the underlying Riemann surface.
This result follows from the work of Stone (1976) and Oh (2005) through a rich
interplay between Riemannian geometry and combinatorial geometry. We provide an
exposition of these proofs and some new applications to conformal tilings.Comment: 30 pages, 7 figure
Baseline characteristics of women presenting with breast cancer at the Radiotherapy Unit of Victoria Hospital, Mauritius
Breast cancer is considered to be the most frequently occurring cancer in females worldwide. The aims of the study were to analyze the various clinical presentations of breast cancer at a cancer referral centre in Mauritius with respect to patient characteristics and tumour characteristics and to explore the association of breast cancer and some possible risk factors namely smoking, family history and oral contraception. Fifty-one confirmed female breast cancer patients were reviewed. Of these, 30 were post-menopausal and 21 were pre-menopausal. The mean and median ages at presentation were respectively 49.4 and 50.0 years respectively. Most patients presented with a painless lump (76.5%). The mean delay in seeking medical advice was 2.4 months. Most patients presented with T2 tumours (56.9%) followed by 13.6% who presented with T1 tumours and 7.9% who presented with T3 tumours. Tumour size was not available for 21.6% of women. 13.7% of patients presented with Stage 1, 41.2% with Stage 2, 15.7% with Stage 3 and 3.9% presented with Stage 4 disease. Information about stage was not available for 25.5% of patients in our study. Grades of tumours at presentation were as follows: 5.9% had Grade 1 tumours, 43.1% had Grade 2 tumours and 23.5% had Grade 3 tumours and information about grade was not available for 27.5% of tumours. Infiltrating ductal carcinoma was the most common histological type accounting for 70.6% of all histological types. It was observed that 52.9% of women did not have any axillary lymph node metastasis at the time of diagnosis whilst 37.3% did. Axillary lymph node status was not available for 9.8 % of women. The association of smoking, family history of breast carcinoma and oral contraception with women presenting with breast cancer in our study was not established. A study such as this provides an overview of the clinical presentation of breast cancer in Mauritius.Keywords: breast cancer, risk factors for breast cancer, tumour size, tumour grade, tumour stage, and histological typ
Dynamic Focusing of Large Arrays for Wireless Power Transfer and Beyond
We present architectures, circuits, and algorithms for dynamic 3-D lensing and focusing of electromagnetic power in radiative near- and far-field regions by arrays that can be arbitrary and nonuniform. They can benefit applications such as wireless power transfer at a distance (WPT-AD), volumetric sensing and imaging, high-throughput communications, and optical phased arrays. Theoretical limits on system performance are calculated. An adaptive algorithm focuses the power at the receiver(s) without prior knowledge of its location(s). It uses orthogonal bases to change the phases of multiple elements simultaneously to enhance the dynamic range. One class of such 2-D orthogonal and pseudo-orthogonal masks is constructed using the Hadamard and pseudo-Hadamard matrices. Generation and recovery units (GU and RU) work collaboratively to focus energy quickly and reliably with no need for factory calibration. Orthogonality enables batch processing in high-latency and low-rate communication settings. Secondary vector-based calculations allow instantaneous refocusing at different locations using element-wise calculations. An emulator enables further evaluation of the system. We demonstrate modular WPT-AD GUs of up to 400 elements utilizing arrays of 65-nm CMOS ICs to focus power on RUs that convert the RF power to dc. Each RFIC synthesizes 16 independently phase-controlled RF outputs around 10 GHz from a common single low-frequency reference. Detailed measurements demonstrate the feasibility and effectiveness of RF lensing techniques presented in this article. More than 2 W of dc power can be recovered through a wireless transfer at distances greater than 1 m. The system can dynamically project power at various angles and at distances greater than 10 m. These developments are another step toward unified wireless power, sensing, and communication solutions in the future
Surveying and Calculation of a Given Area using a Quad-copter
The field of geometry has various applications and calculating the area is one of them and doing it manually is challenging and equally a daunting task. In this paper we propose a method to make use of a flying object with a camera to calculate the area. This can be achieved by augmenting the flying object with a camera that takes pictures and these pictures can be used and we can perform some operations to calculate the area of a given plane in an image. This not only saves time that an entity invests but also saves the amount of money he/she invests in the calculation of the area. We can enhance the calculation by incorporating much faster techniques and methods
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