1,198 research outputs found
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Determination of machinable volume for finish cuts in CAPP
Identification of machinable volume for finish cut is a complex task as it involves the details not only of the final product but also the intermediate part obtained from rough machining of the blank. A feature recognition technique that adopts a rule-based methodology is required for calculating this small, complex shaped finish cut volume. This paper presents the feature recognition module in a CAPP system that calculates the intermediate finish cut volume by adopting a rule based syntactic pattern recognition approach. In this module, the interfacer uses STEP AP203/214, a CAD neutral format, to trace the coordinate point information and to calculate the machinable volume. Two illustrative examples are given to explain the proposed syntactic pattern approach for prismatic parts
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STEP based Finish Machining CAPP system
This research paper presents various methodologies developed in a STEP based Computer Aided Process Planning (CAPP) system named "Finish Machining β CAPP" (FM-CAPP). It is developed to generate automatic process plans for finish machining prismatic parts. It is designed in a modular fashion consisting of three main modules, namely (i) Feature Recognition module (FRM) (ii) Machining Planning Module (MPM) and (iii) Setup Planning Module (SPM). The FRM Module analyses the geometrical and topological information of the inputted part in STEP AP 203/AP214 formats, and generates a text file with full dimensional details of features and machinable volumes. It is then passed on to the MPM for the selection of best suited machining process. Here, the selection is based on a 7 stage elimination strategy considering major manufacturing factors. After machining planning, the task of selecting the best suited setup is implemented in the SPM module. When these tasks are completed, the system generates the process-planning sheet containing the details of feature, finish cut machinable volume, machining processes with the cutting tool/ media, process parameters and the setup required for machining
Evaluation of Hibiscus esculentus Linn. on the Mechanical and Disintegration Properties of Paracetamol Tablets
The effects of mucilage obtained from the ripe fruits of Hibiscus esculentus Linn. (Malvaceae) on the mechanical and disintegration properties of paracetamol tablets were investigated against gum acacia as a standard binding agent. The effects of the nature and concentration of the mucilage binder and the relative density of the tablet on the tensile strength, brittle fracture index and disintegration time of the tablets were investigated. Relative density, concentration and nature of binder had the greatest effects on tensile strength, brittle fracture index and disintegration time,respectively. Increasing, the concentration of mucilage from 2.5 % to 10.0 % w/w, and increasing relative density of the tablet from 0.70 to 0.80 led to an increase in tensile strength and disintegration time, but a decrease in brittle fracture index. Tablets formulated with H. esculentus mucilage had lower tensile strength and disintegration time values than those containing gum acacia, and exhibited less lamination and capping. The nature and concentration of binder had the highest interaction among the factors studied. In conclusion, Hibiscus esculentus mucilage could be useful as an alternative binding agent to gum acacia, especially wherefaster disintegration is required and lamination and capping are of concern
A Simple Auditable Fingerprint Authentication Scheme Using Smart-Contracts
Biometric authentication, and notably using fingerprints, are now
common. Despite its usability, biometrics have however a caveat which is the
impossibility of revocation: once the raw fingerprint is breached, and depending
on the technology of the reader, it is impossible to stop an illegitimate authentication. This places a focus on auditing both to detect fraud and to have clear indications that the fingerprint has been breached. In this paper we show how to take advantage of the immutability property of Blockchains to design an auditable protocol based on Diffie-Hellman key exchange with applications to fingerprint authentication
A New Biometric Template Protection using Random Orthonormal Projection and Fuzzy Commitment
Biometric template protection is one of most essential parts in putting a
biometric-based authentication system into practice. There have been many
researches proposing different solutions to secure biometric templates of
users. They can be categorized into two approaches: feature transformation and
biometric cryptosystem. However, no one single template protection approach can
satisfy all the requirements of a secure biometric-based authentication system.
In this work, we will propose a novel hybrid biometric template protection
which takes benefits of both approaches while preventing their limitations. The
experiments demonstrate that the performance of the system can be maintained
with the support of a new random orthonormal project technique, which reduces
the computational complexity while preserving the accuracy. Meanwhile, the
security of biometric templates is guaranteed by employing fuzzy commitment
protocol.Comment: 11 pages, 6 figures, accepted for IMCOM 201
Fermentation process for alcoholic beverage production from mahua (Madhuca indica J. F. Mel.) flowers
Mahua flowers are rich in sugar (68-72%), in addition to a number of minerals and one of the most important raw materials for alcohol fermentation. The present investigation was for the development of a non-distilled alcoholic beverage from Mahua flowers. Eighteen (18) treatment combinations consisting of two temperatures (25 and 30Β°C), three pH (4.0, 4.5 and 5.0) and three period of fermentation (7, 14 and 21 days) were used in the fermentation conditions. The maximum yield of ethanol (9.51 %) occurred at 25Β°C with pH 4.5 after 14 days ofΒ fermentation of Mahua flower juice. The fermented non-distilled alcoholic beverage contained total sugar (8.83 mg/ml), reducing sugar (0.82 mg/ml), total soluble solids (6.37Β°Brix) titrable acidity (0.65 %), and volatile acidity (0.086%). Methanol was not detected at any stage of fermentation. The developed fermented alcoholic beverage had characteristic flavor and aroma of Mahua flowers with about 7 to 9% alcohol.Keywords: Madhuca indica, ethanol, reducing sugar, fermentation.African Journal of Biotechnology Vol. 12(39), pp. 5771-577
Estimation of greenhouse gas emissions from spontaneous combustion/fire of coal in opencast mines β Indian context
There are a significant number of uncontrolled coal mine fires (primarily due to spontaneous combustion of coal), which are currently burning all over the world. These spontaneous combustion sources emit greenhouse gases (GHGs). A critical review reveals that there are no standard measurement methods to estimate GHG emissions from mine fire/spontaneous combustion areas. The objective of this research paper was to estimate GHGs emissions from spontaneous combustion of coals in the Indian context. A sampling chamber (SC) method was successfully used to assess emissions at two locations of the Enna Opencast Project (OCP), Jharia Coalfield (JCF), for 3 months. The study reveals that measured cumulative average emission rate for CO2 varies from 75.02 to 286.03 gsβ1mβ1 and CH4 varies from 41.49 to 40.34 gsβ1mβ1 for low- and medium-temperature zones. The total GHG emissions predicted from this single fire affecting mines of JCF vary from 16.86 to 20.19 Mtyrβ
Lung cancer cytology: potential pitfalls- a review
Lung Cancer, a cancer that forms in tissues of the lung, usually in the cells lining air passages, has traditionally been classified into two major types: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). About 85 percent of all lung cancers are identified as non-small cell, and approximately 75 percent of these are metastatic or advanced at diagnosis. Recent findings have changed our understanding of the disease, and today distinct molecular subsets of lung cancer have been identified that can be classified by a biomarker profile of a patientβs tumor. In spite of advances in early diagnosis and standard treatment, non-small cell lung cancer is regularly analysed at advanced stages and has a poor prognosis. The treatment and prevention of lung cancer are major needs that can most likely be enhanced by a better understanding of the molecular process in cancer and development of cancer. However, significant progress is underway in both the prevention and treatment of lung cancer. Lung cancer therapy has now emerged as a βrole modelβ for precision cancer medicine. Cytology is increasingly being used in the evaluation of lung lesions. There are several potential pitfalls encountered in the evaluation of respiratory cytology specimens, making interpretation of respiratory cytology challenging.
Keywords: Lung Cancer, non-small cell lung cancer, small cell lung cancer, Cytology, potential pitfalls
A spatiotemporal Data Envelopment Analysis (S-T DEA) approach:the need to assess evolving units
One of the major challenges in measuring efficiency in terms of resources and outcomes is the assessment of the evolution of units over time. Although Data Envelopment Analysis (DEA) has been applied for time series datasets, DEA models, by construction, form the reference set for inefficient units (lambda values) based on their distance from the efficient frontier, that is, in a spatial manner. However, when dealing with temporal datasets, the proximity in time between units should also be taken into account, since it reflects the structural resemblance among time periods of a unit that evolves. In this paper, we propose a two-stage spatiotemporal DEA approach, which captures both the spatial and temporal dimension through a multi-objective programming model. In the first stage, DEA is solved iteratively extracting for each unit only previous DMUs as peers in its reference set. In the second stage, the lambda values derived from the first stage are fed to a Multiobjective Mixed Integer Linear Programming model, which filters peers in the reference set based on weights assigned to the spatial and temporal dimension. The approach is demonstrated on a real-world example drawn from software development
Predicting the safety and efficacy of butter therapy to raise tumour pHe: an integrative modelling study
Background: Clinical positron emission tomography imaging has demonstrated the vast majority of human cancers exhibit significantly increased glucose metabolism when compared with adjacent normal tissue, resulting in an acidic tumour microenvironment. Recent studies demonstrated reducing this acidity through systemic buffers significantly inhibits development and growth of metastases in mouse xenografts.\ud
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Methods: We apply and extend a previously developed mathematical model of blood and tumour buffering to examine the impact of oral administration of bicarbonate buffer in mice, and the potential impact in humans. We recapitulate the experimentally observed tumour pHe effect of buffer therapy, testing a model prediction in vivo in mice. We parameterise the model to humans to determine the translational safety and efficacy, and predict patient subgroups who could have enhanced treatment response, and the most promising combination or alternative buffer therapies.\ud
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Results: The model predicts a previously unseen potentially dangerous elevation in blood pHe resulting from bicarbonate therapy in mice, which is confirmed by our in vivo experiments. Simulations predict limited efficacy of bicarbonate, especially in humans with more aggressive cancers. We predict buffer therapy would be most effectual: in elderly patients or individuals with renal impairments; in combination with proton production inhibitors (such as dichloroacetate), renal glomular filtration rate inhibitors (such as non-steroidal anti-inflammatory drugs and angiotensin-converting enzyme inhibitors), or with an alternative buffer reagent possessing an optimal pK of 7.1β7.2.\ud
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Conclusion: Our mathematical model confirms bicarbonate acts as an effective agent to raise tumour pHe, but potentially induces metabolic alkalosis at the high doses necessary for tumour pHe normalisation. We predict use in elderly patients or in combination with proton production inhibitors or buffers with a pK of 7.1β7.2 is most promising
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