On-machine focus variation measurement for micro-scale hybrid surface texture machining

Fast and accurate in-line areal surface topography measuring instruments are required to control the quality of microscale manufactured components, without significantly slowing down the production process. Full-field areal optical surface topography measurement instruments are promising for in-line or on-machine measurement applications due to their ability to measure quickly, to access small features and to avoid surface damage. This paper presents the development and integration of a compact optical focus variation sensor for on-machine surface topography measurement mounted on to a hybrid ultraprecision machine tool. The sensor development is described and a case study involving the on-machine dimensional measurement of the depth of hydrophobic microscale features, including microchannels and micro-dimples, is presented. Comparisons of results between the on-machine measurements obtained by the developed sensor and a desktop focus variation microscope are presented and discussed. The comparison results show that the developed focus variation sensor is able to perform on-machine dimensional measurement of microscale features within sub-micrometre accuracy

A NOVEL ENTER WORD SEARCH WITH NOMINATED TESTER AND TIMING FACILITATE EXCHANGE RE CIPHER TEXT ROLE FOR ONLINE PHYSICAL CLOUDS

The Search File Encryption (SE) plan is indeed a technology that includes security and favorable functionality that can play a very important role in the e-health registration system. The Digital Health Information Product is a unique application that offers great comfort in healthcare. In this document, we present a unique encryption primitive, called a common search engine for the searcher, and a timing-enabled proxy transfer encryption, which is a time-dependent SE plan. We designed a unique search file encryption plan that supports secure search for affiliate keywords and approved broadcast functionality. Unlike in existing systems, work can synchronize the re-encryption of the proxy file allowed by effective cancellation of the delegation. The security and privacy of sensitive private data are major user concerns that may hinder the development and widespread deployment of systems. We create a method model together with a security model so that the proposed Re-dtPECK plan shows that it is a skilled plan that has proven to be safe in a standard model. Comparison and large-scale simulations show that it represents low computation and storage. It could allow patients to transfer the legal rights of others to a partial use to perform search operations on their records within a short period of time. The time period during which the Trustee can view and decrypt the Trusted Encrypted Document can be managed

Development of a compact focus variation microscopy sensor for on-machine surface topography measurement

On-machine areal surface topography measuring instruments are required for fast and accurate measurement of parts inside production machines without reducing production rates. This paper presents the design and development of a compact focus variation microscopy sensor that can be integrated into various types of machine tools. The paper focuses on the development of the linear stage of the sensor, which was the major engineering challenge. The overall developed sensor has dimensions of 78 mm diameter and 200 mm length, with a 20 mm travel range. Simulations of tolerance stack-ups for the sensor assembly were performed before the manufacturing of the sensor’s linear motion components to assure they can be appropriately assembled. The linear motion accuracy of the sensor is 2 μm, calibrated using laser interferometry. From measurement in a controlled laboratory, the measurement noise of the sensor is 0.4 μm. Finally, demonstrations of calibrated artefact measurements with the sensor are presented. A single image field measurement with the sensor requires less than 20 s

Fluorosis risk from early exposure to fluoride toothpaste

Swallowed fluoride toothpaste in the early years of life has been postulated to be a risk factor for fluorosis, but the epidemiological evidence is weakened by the fact that most of the relevant studies were done in developed countries where an individual is exposed to multiple sources of fluoride. Objectives: To quantify the risk of fluorosis from fluoride toothpaste in a population whose only potential source of fluoride was fluoride toothpaste. Methods: Case-control analyses were conducted to test the hypothesis that fluoride toothpaste use before the age of 6 years increased an individual's risk of fluorosis. Data came from a cross-sectional clinical dental examination of schoolchildren and a self-administered questionnaire to their parents. The study was conducted in Goa, India. The study group consisted of 1189 seventh grade children with a mean age of 12.2 years. Results: The prevalence of fluorosis was 12.9% using the TF index. Results of the crude, stratified, and logistic regression analyses showed that use of fluoride toothpaste before the age of 6 years was a risk indicator for fluorosis (OR 1.83, 95% CI 1.05–3.15). Among children with fluorosis, beginning brushing before the age of 2 years increased the severity of fluorosis significantly ( P < 0.001). Other factors associated with the use of fluoride toothpaste, such as eating or swallowing fluoride toothpaste and higher frequency of use, did not show a statistically significant increased risk for prevalence or severity of fluorosis. Conclusions: Fluoride toothpaste use before the age of 6 years is a risk indicator for fluorosis in this study population.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75437/1/j.1600-0528.1998.tb01957.x.pd

<i>In vitro </i> comparison of NiTi rotary instruments and stainless steel hand instruments in root canal preparations of primary and permanent molar

This study is an attempt to compare the NiTi rotary and K-files hand instrumentation on root canal preparation of primary and permanent molars for their efficiency in preparation time, instrument failure and shaping the canals. About 20 primary mandibular second molar (I) and 20 permanent mandibular first molar (II) were selected. Each was further divided into 10 for K-files (a) and 10 for NiTi (b) groups, respectively. Results showed that preparation time Ib&lt;Ia and IIab&lt;IIa, which was highly significant. In instrument failure, Ia (40&#x0025;), IIa (30&#x0025;) showed more deformation but not fracture and Ib (10&#x0025;), IIb (20&#x0025;) showed fracture, but not deformation. Profiles showed good canal taper and smoothness compared to the K-files. To conclude profile 0.04 taper 29 series, prepared canal rapidly than conventional K-file with good taper, smoothness though the flow was not satisfactory. Instrument failure with K-files was less. In primary teeth preparation time, instrument failure with profile was less compared to the permanent. To conclude it&#x2032;s encouraging to use the profiles in primary teeth

Hybrid reynolds-averaged and large-eddy simulation of mixing in an axisymmetric scramjet

An unsteady numerical simulation of a simple axisymmetric inlet-fuelled scramjet engine concept is performed using a hybrid Reynolds-averaged Navier-Stokes and large-eddy simulation approach with a low-dissipation numerical scheme. The freestream has a Mach number of 7.5 with Mach 8 flight enthalpy and a dynamic pressure of 48 kPa. The simulation is of a non-reacting case where hydrogen is injected into nitrogen. The simulation is used to provide a detailed description of the structure of the flow. The simulation shows that a large-scale pair of counter-rotating vortices forms within the scramjet combustor, with rotation opposite to the rotation of the pair that forms further upstream due to the interaction of the fuel plume with the crossflow. This vortex pair is found to signicantly alter the shape of the hydrogen fuel plume, and increase the rate at which the hydrogen is mixing by more than a factor of two compared to before the vortex pair is formed. The distribution of hydrogen is examined in detail, including instantaneous mole fraction, the time-averaged mole fraction, as well as root mean square of fluctuations of hydrogen mole fraction. The time-averaged and fluctuating wall pressures, the mean velocity eld, and resolved turbulence quantities are also examined. Additionally, the hybrid Reynolds-averaged Navier-Stokes and large-eddy simulation results are used to evaluate the performance of a steady-state Reynolds-averaged Navier-Stokes simulation of the conguration

A survey of signal processing based graph learning techniques

Recent advances in technology have led to easy data acquisition mechanisms in many fields, leading to massive datasets. It is often of interest to understand the inherent structure and learn the best representation of the given dataset. Graphs are a powerful way to model interrelationships between data features-well constructed meaningful graphs help in representing and processing the data effectively. The graph topology needs to be inferred from the observed data. In this survey, we briefly explore signal processing based graph learning approaches that have been proposed in the literature and propose new research directions