184 research outputs found

    The role of tool geometry in process damped milling

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    The complex interaction between machining structural systems and the cutting process results in machining instability, so called chatter. In some milling scenarios, process damping is a useful phenomenon that can be exploited to mitigate chatter and hence improve productivity. In the present study, experiments are performed to evaluate the performance of process damped milling considering different tool geometries (edge radius, rake and relief angles and variable helix/pitch). The results clearly indicate that variable helix/pitch angles most significantly increase process damping performance. Additionally, increased cutting edge radius moderately improves process damping performance, while rake and relief angles have a smaller and closely coupled effect

    Metanephric adenoma of the kidney: an unusual diagnostic challenge

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    Although metanephric adenoma (MA) is a rare, benign neoplasm of epithelial cells, it is often difficult to distinguish this entity from other malignant neoplasms preoperatively. We report a case of a large renal mass for which preoperative diagnosis was indeterminate, with the differential diagnosis including Wilm’s tumor, MA, and papillary renal cell carcinoma (PRCC). Accurate postoperative differentiation of MA from PRCC is critical because adjuvant therapy is considered after surgical resection of PRCC tumors

    A glucose biosensor based on novel Lutetium bis-phthalocyanine incorporated silica-polyaniline conducting nanobeads

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    The facile preparation of highly sensitive electrochemical bioprobe based on lutetium 13 phthalocyanine incorporated silica nanoparticles (SiO2(LuPc2)) grafted with Poly(vinyl 14 alcohol-vinyl acetate) itaconic acid (PANI(PVIA)) doped polyaniline conducting nanobeads 15 (SiO2(LuPc2)PANI(PVIA)-CNB) is reported. The preparation of CNB involves two stages (i) 16 pristine synthesis of LuPc2 incorporated SiO2 and PANI(PVIA); (ii) covalent grafting of 17 PANI(PVIA) onto the surface of SiO2(LuPc2). The morphology and other physico-chemical 18 characteristics of CNB were investigated. The scanning electron microscopy images show 19 that the average particle size of SiO2(LuPc2)PANI(PVIA)-CNB was between 180-220 nm. 20 The amperometric measurements showed that the fabricated SiO2(LuPc2)PANI(PVIA)-21 CNB/GOx biosensor exhibited wide linear range (1-16 mM) detection of glucose with a low 22 detection limit of 0.1 mM. SiO2(LuPc2)PANI(PVIA)-CNB/GOx biosensor exhibited high 23 sensitivity (38.53 μA mM−1 cm−2) towards the detection of glucose under optimized 24 conditions. Besides, the real (juice and serum) sample analysis based on a standard addition 25 method and direct detection method showed high precision for measuring glucose at 26 SiO2(LuPc2)PANI(PVIA)-CNB/GOx biosensor. The SiO2(LuPc2)PANI(PVIA)-CNB/GOx 27 biosensor stored under refrigerated condition over a period of 45 days retains ~ 96.4 % 28 glucose response current

    Flow-Dependent Mass Transfer May Trigger Endothelial Signaling Cascades

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    It is well known that fluid mechanical forces directly impact endothelial signaling pathways. But while this general observation is clear, less apparent are the underlying mechanisms that initiate these critical signaling processes. This is because fluid mechanical forces can offer a direct mechanical input to possible mechanotransducers as well as alter critical mass transport characteristics (i.e., concentration gradients) of a host of chemical stimuli present in the blood stream. However, it has recently been accepted that mechanotransduction (direct mechanical force input), and not mass transfer, is the fundamental mechanism for many hemodynamic force-modulated endothelial signaling pathways and their downstream gene products. This conclusion has been largely based, indirectly, on accepted criteria that correlate signaling behavior and shear rate and shear stress, relative to changes in viscosity. However, in this work, we investigate the negative control for these criteria. Here we computationally and experimentally subject mass-transfer limited systems, independent of mechanotransduction, to the purported criteria. The results showed that the negative control (mass-transfer limited system) produced the same trends that have been used to identify mechanotransduction-dominant systems. Thus, the widely used viscosity-related shear stress and shear rate criteria are insufficient in determining mechanotransduction-dominant systems. Thus, research should continue to consider the importance of mass transfer in triggering signaling cascades

    A stabilising control strategy for Cyber-Physical Power Systems

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    The cyber-physical nature of electric power systems has increased immensely over the last decades, with advanced communication infrastructure paving the way. It is now possible to design wide-area controllers, relying on remote monitor and control of devices, that can tackle power system stability problems more effectively than local controllers. However, their performance and security relies extensively on the communication infrastructure and can make power systems vulnerable to disturbances emerging on the cyber side of the system. In this paper, we investigate the effect of communication delays on the performance of wide-area damping controllers (WADC) designed to stabilise oscillatory modes in a Cyber-Physical Power System (CPPS). We propose a rule-based control strategy that combines wide-area and traditional local stabilising controllers to increase the performance and maintain the stable operation of CPPS. The proposed strategy is validated on a reduced CPPS equivalent model of Great-Britain (GB)

    Cancer Biomarker Discovery: The Entropic Hallmark

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    Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases

    7th Drug hypersensitivity meeting: part two

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