Curvelet Transform Based Watermarking for Telemedicine

Now a days telemedicine is a proactive research area and gaining more engrossment. Digital transmission of medical imaging, remote evaluation and diagnosis together are termed as Telemedcine and it has increasingly gained prominence in the recent times. Remote specialist reckons intemperately on scan images or medicinal images and data of patient for devising diagnostic conclusion. While imparting a scan image (clinical picture) to remote authority, the significant part (ROI) in it may be altered by interlopers. The remote authority must recover the ROI in a clinical picture on the off chance that it has been altered. This paper presents a novel robust watermarking method founded on Curvelet Transform to recover the ROI in medical image in case it is altered. The proposed method hides ROI information inside diagnostically insignificant part in medical image through Curvelet Transform. Experiments carried out using this novel technique have proven that the ROI in medical image is restored to its original state.

     

One-pot synthesis of conducting graphene-polymer composites and their strain sensing application

In situ reduction of graphite oxide in polymer powder has been implemented using focused solar electromagnetic radiation. The simultaneous reduction of graphite oxide, melting of the polymer and embedding of reduced graphite oxide nanoflakes in polymer offer a new way of synthesizing conducting graphene/polymer composites. An electromechanical application of the present reduced graphite oxide-PVDF nanocomposite has been proposed with a gauge factor of 12.1.     

Functionalized Graphene–PVDF Foam Composites for EMI Shielding

Novel foam composites comprising functionalized graphene (f‐G) and polyvinylidene fluoride (PVDF) were prepared and electrical conductivity and electromagnetic interference (EMI) shielding efficiency of the composites with different mass fractions of f‐G have been investigated. The electrical conductivity increases with the increase in concentration of f‐G in insulating PVDF matrix. A dramatic change in the conductivity is observed from 10^?16 S · m^?1 for insulating PVDF to 10^?4 S · m^?1 for 0.5 wt.% f‐G reinforced PVDF composite, which can be attributed to high‐aspect‐ratio and highly conducting nature of f‐G nanofiller, which forms a conductive network in the polymer. An EMI shielding effectiveness of ≈20 dB is obtained in X‐band (8–12 GHz) region and 18 dB in broadband (1–8 GHz) region for 5 wt.% of f‐G in foam composite. The application of conductive graphene foam composites as lightweight EMI shielding materials for X‐band and broadband shielding has been demonstrated and the mechanism of EMI shielding in f‐G/PVDF foam composites has been discussed.

     

Graphene-based engine oil nanofluids for tribological applications

Ultrathin graphene (UG) has been prepared by exfoliation of graphite oxide by a novel technique based on focused solar radiation. Graphene based engine oil nanofluids have been prepared and their frictional characteristics (FC), antiwear (AW), and extreme pressure (EP) properties have been evaluated. The improvement in FC, AW, and EP properties of nanofluids is respectively by 80, 33, and 40% compared with base oil. The enhancement can be attributed to the nanobearing mechanism of graphene in engine oil and ultimate mechanical strength of graphene.     

Selection of Gravity Separators for the Beneficiation of the Uljin Tin Ore

Gravity separation is typically used in the beneficiation of tin ores as the density difference between the valuable and associated gangue minerals is significant. In the present investigation, a cassiterite sample collected from the Uljin deposit in South Korea has been subjected to different gravity separators to evaluate the separation efficiency. The selection of gravity units has been made based on performance evaluation following heavy liquid separation and assessment of grade/recovery curves and Tromp curve methods. In addition, a gravity separation index (GSI) has been proposed that is simpler than other methods for assessing the performance of gravity separators.     

Minimization of fines generation in size reduction of coals by impact crusher

In Bubbling Fluidized Bed Combustors (BFBC) utilizing coal, efficient combustion requires that feed size of coal particles be in the maximum size range of 2 to 6 mm. This requires that the comminution process be effective. In this work, various types of coals have been comminuted in an impact crusher. The size reduction process is characterized by four process parameters and relevant properties of the coal samples. Taguchi's design of experiment was used to minimize the number of experiments done to obtain meaningful results. It was concluded from the experiments that among process parameters, RPM has a more prominent effect on generation of fines compared to feed rate, feed size and gap setting. Among coal properties, volatile matter, ash content and fixed carbon have significant effect, followed by moisture content. RPM has relatively less influence on coarse particle (> 6 mm) content. An empirical correlation has been formulated based on the data to predict the generation of fines for a given set of process parameters and physical properties of coals. The results obtained using the model was within the acceptable accuracy when compared to the experimental data. The same correlation has also been applied successfully to fit the cement production from a plant, indicating that it has merit beyond the laboratory and that the specific type of crusher is immaterial, provided the mechanism of size reduction remains the same.     

Grinding characteristics of coal and petroleum coke/coal blends on utilization for combustion

ABSTRACT

Petroleum coke (PC) blend with coal is an attractive feedstock for combustion process. The present work investigates the grinding characteristics of PC blend with coal in a laboratory ball mill to meet an industrial tube mill conditions. Tests were carried out using a laboratory batch ball mill for optimal production of ?200 mesh size product. The ground products at different combinations were subjected to sink-float tests. Experimental results suggested that the petcoke with coal at 5.0% blend ratio was optimum for generation of ?200 mesh size product. It was also observed that increasing coal/petcoke blend ratio beyond 5.0% leads to a decrease in ?200 mesh size generation. The better performance could be achieved at the blending ratio of 5%, perhaps resulting from the synergistic effect of the blends. With the aforementioned blend ratio, the optimal condition of the milling time was found to be 3 h. The percentage of coal to the total charge and percentage of petcoke to the total charge of the ball mill product at various blends were also calculated for all the blends and at all grinding time intervals. The results obtained could provide a useful insight to predict the industrial mill performance.     

Milling and Classification of Printed Circuit Boards for Material Recycling

Recycling of waste electric and electronic equipment (WEEE) is an emerging issue due to its hazardous nature. It is important to identify an appropriate environment-friendly process to recover the valuables and for safe disposal. The present work deals with the two-stage crushing process followed by a circulating air classifier for the separation of metals and nonmetals from the printed circuit boards (PCB). The two-stage crushing process is deployed to liberate the valuables for an appropriate progeny size distribution. The metal content decreases as the particle size decreases below 0.5 mm. However, it increases metal content above 500 µm up to 1,800 µm. It is concluded that the metals primarily enriched in the size range of ?1.8 + 0.5 mm. The amount of metals and plastics present in each fraction is estimated. Among the classifier parameters, air flow velocity played a dominant role in metal enrichment. The material feed rate and rotating guide vane angle have no a significant effect on the enrichment of metals and nonmetals. The air flow velocity found was to be one of the crucial parameters for enrichment of metals. The superficial air flow velocity is optimized for efficient separation of metals and nonmetals of PCBs.     

Experimental and Simulation Studies on Milling of Rice Husk

A study was conducted to investigate the size reduction characteristics of rice husk in a batch ball mill. The most popular population balance model was chosen for the analysis. The model parameters are the breakage distribution function (β) and breakage rate function (α). Experiments are conducted with three different feed sizes of rice husk at three different ball charges. From the experimental data, the best fitting breakage distribution function parameter is found. The breakage rate function parameters with process variables such as feed size, ball charge were calculated. The best correlation for the parameter with process variables was obtained by multiple linear regression analysis. Additional experiments were also conducted at different process conditions to verify the correlation. The accuracy of the correlation is also verified for pet coke data of Ray (2000 Ray , P. 2000 . Studies on size reduction characteristics of petcoke using a ball mill. M.Tech. thesis, Indian Institute of Technology Madras, India.  [Google Scholar]). The correlation describes the experimental data with acceptable accuracy for rice husk and also for pet coke data within the range of process variables studied in this investigation. The calculated values of the breakage rate obtained through the developed correlations have been compared with the respective experimental values with root mean square error of 1.25% and correlation coefficient of 0.95. It is also found that the calculated values agree well with the experimental values.