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Three-dimensional (3D) printing is an additive manufacturing method in which by laying down successive layers of material a 3D item is formed. Charles Hull created the 3D printer which used the technique of stereolithography, as well as the first program for virtualization.Various types of polymers,gels , resins and powders are the materials employed in 3D printing.3D printing techniques includes liquid based, solid based and powder based using which surgical guides and implant abutment can be fabricated .The accuracy of 3D printed implants is assessed by global deviation, angular deviation, depth deviation and lateral deviation. Even though the complications and disadvantages are associated with 3D printing, they can achieve higher precision and accuracy in implant placement. However, further studies are needed to evaluate their clinical outcome over time and function..

Esthetics plays a vital role in the prosthodontic rehabilitations. In patients with proclined premaxillary region/labial undercut, it is challenging to the prosthodontist to achieve the desirable esthetics. In this article we will discussing about a non-surgical management of the proclined premaxilla in a complete denture patient using a modified flange.

The Sub keV Atom Reflecting Analyzer instrument on board the lunar orbiter Chandrayaan 1 provided a large number of measurements of lunar energetic neutral atoms (ENAs). These ENAs were formerly solar wind ions which were neutralized and backscattered from the lunar surface. The angles under which the ENAs are scattered strongly depend on the solar wind ions' incidence angle which corresponds to the solar zenith angle (SZA). Our large dataset provides us with a complete coverage of the SZA and almost complete coverage of the scattering angles. When combining all available measurements four distinct features are discernible with SZA increase: amplitude decrease less azimuthal uniformity bigger ratio of sunward versus anti sunward flux and shallower scattering. We analyzed more than 290'000 measurements and derived a mathematical description of the features and their dependencies on the SZA. Citation: Schaufelberger A. P. Wurz S. Barabash M. Wieser Y. Futaana M. Holmstrom A. Bhardwaj M. B. Dhanya R. Sridharan and K. Asamura (2011) Scattering function for energetic neutral hydrogen atoms off the lunar surface Geophys. Res. Lett. 38 L22202 doi:10.1029/2011GL049362.

We report observations of a steady 20 year decline of solar photospheric fields at latitudes $\geq$45${^{o}}$ starting from $\sim$1995. This prolonged and continuing decline, combined with the fact that Cycle 24 is already past its peak, implies that magnetic fields are likely to continue to decline until $\sim$2020, the expected minimum of the ongoing solar Cycle 24. In addition, interplanetary scintillation (IPS) observations of the inner heliosphere for the period 1983--2013 and in the distance range 0.2--0.8 AU, have also shown a similar and steady decline in solar wind micro-turbulence levels, in sync with the declining photospheric fields. Using the correlation between the polar field and heliospheric magnetic field (HMF) at solar minimum, we have estimated the value of the HMF in 2020 to be 3.9 ($\pm$0.6) and a floor value of the HMF of $\sim$3.2 ($\pm$0.4) nT. Given this floor value for the HMF, our analysis suggests that the estimated peak sunspot number for solar Cycle 25 is likely to be $\sim$ 62 ($\pm$12)., Comment: Accepted for publication in JGR (Space Physics)

In this paper, the effect of rotation on impingement cooling on the internal surface (profile) of the leading edge region in a turbine rotor blade is investigated using Computational Fluid Dynamics (CFD) simulations. The flow domain is obtained by stretching the middle cross section of the blade. The simulations are performed for 3 different leading edge profiles to increase the heat transfer rate in the cooling flow passage in stationary domain. In all the profiles, the nozzle position and Mach number of cooling fluid is kept constant at E/D = 4.32 and 0.4 respectively. In the profile 1, the suction side profile is modified to facilitate vortex shift so that it may reduce the crossflow effect which will enhance the Nuavg. But Nuavg reduced by 1.9% when compared to base case. In the profile 2, the coolant flow passage is smoothened at the apex to reduce dead zones and to enhance spreading of the jet. In this case, a 3.48% increase in Nuavg is obtained. Based on the analysis of velocity contours in the profile 2, the leading edge profile is further modified (profile 3). This resulted in 5.37% increase in the Nuavg. The effect of rotation on the Nuavg for different Mach numbers (M) in the profile 3 and base case are studied. When compared to stationary domain Nuavg is reduced for base case and profile 3. In rotating domain profile 3 shows improvement for different M when compared with base case. For M = 0.2, the Nuavg is increased by 2.7%, for M = 0.4, Nuavg is increased by 3.98% and for M = 0.6, it is negligible.Copyright © 2014 by ASME

The performance of the compressor blade is considerably influenced by secondary flow effects, like the cross flow on the end wall as well as corner flow separation between the wall and the blade. The present work is focused on the studying the effects of Vortex Generator (VG) on NASA Rotor 37 test case using Computational Fluid Dynamics (CFD). VG helps in controlling the inception of the stall by generating vortices and energizes the low momentum boundary layer flow which enhances the rotor performance. Three design configuration namely, Counter-rotating, Co-rotating and Plow configuration VG are selected based on the improved aerodynamic performance discussed in reference [1]. These VG are located at 90% span and 42% chord on suction side surface of the blade. Among the three configurations, the first configuration has greater impact on the end wall cross flow and flow deflection which resulted in enhanced numerical stall margin of 5.4% from baseline. The reasons for this numerical stall margin improvement are discussed in detail.Copyright © 2014 by ASME

The effect of impingement cooling on the internal surface (cooling passage) of the leading edge region in a commercial turbine high pressure first stage rotor blade is investigated using Computational Fluid Dynamics (CFD) simulations. The flow domain is obtained by stretching the middle cross section (50% span) of the above mentioned blade. The simulations are performed for 3 different profiles in the cooling flow passage. In all the cases, the nozzle position and Mach number of cooling fluid is kept constant at E/D = 4.32 and 0.4 respectively. In the first case, the suction side profile is modified to facilitate shift in the vortex. This may reduce the crossflow effect, which will enhance the Nuavg. However, simulation results showed that Nuavg is reduced by 2% when compared to base case. In the second case, the coolant flow passage is smoothened at the apex to reduce dead zone and to enhance spreading of the jet. In this case, a 3% increase in Nuavg is obtained. Based on the analysis of velocity contours in the second case, the coolant flow passage in the third case is further modified to improve the spreading of flow. This resulted in 5% increase in the Nuavg when compared to base case.Copyright © 2013 by ASME

Significant proton fluxes were detected in the near wake region of the Moon by an ion mass spectrometer on board Chandrayaan-1. The energy of these nightside protons is slightly higher than the energy of the solar wind protons. The protons are detected close to the lunar equatorial plane at a $140^{\circ}$ solar zenith angle, i.e., ~50$^{\circ}$ behind the terminator at a height of 100 km. The protons come from just above the local horizon, and move along the magnetic field in the solar wind reference frame. We compared the observed proton flux with the predictions from analytical models of an electrostatic plasma expansion into a vacuum. The observed velocity was higher than the velocity predicted by analytical models by a factor of 2 to 3. The simple analytical models cannot explain the observed ion dynamics along the magnetic field in the vicinity of the Moon., Comment: 28 pages, 7 figures

SARA experiment aboard the first Indian lunar mission Chandrayaan-1 had the objective to explore the solar wind-lunar interaction using energetic neutral atoms (ENA) from the lunar surface as diagnostic tool. SARA consisted of an ENA imaging mass analyzer CENA (Chandrayaan-1 Energetic Neutral Analyzer) and an ion mass analyser SWIM (Solar Wind Monitor), along with a digital processing unit (DPU) which commands and controls the sensors and provides the interface to the spacecraft. Both sensors have provided excellent observational data. CENA has observed ENAs from the lunar surface and found that ~20% of the incident solar wind ions get backscattered as ENAs from the lunar surface. This is contrary to the previous assumptions of almost complete absorption of solar wind by the lunar surface. The observation is relevant for other airless bodies in the solar system., Comment: 11 pages, 6 figures

The accuracy of position measurements on stellar targets with the future Space Interferometry Mission (SIM) will be limited not only by photon noise and by the properties of the instrument (design, stability, etc.) and the overall measurement program (observing strategy, reduction methods, etc.), but also by the presence of other "confusing" stars in the field of view (FOV). We use a simple "phasor" model as an aid to understanding the main effects of this "confusion bias" in single observations with SIM. This analytic model has been implemented numerically in a computer code and applied to a selection of typical SIM target fields drawn from some of the Key Projects already accepted for the Mission. We expect that less than 1% of all SIM targets will be vulnerable to confusion bias; we show that for the present SIM design, confusion may be a concern if the surface density of field stars exceeds 0.4 star/arcsec^2. We have developed a software tool as an aid to ascertaining the possible presence of confusion bias in single observations of any arbitrary field. Some a priori knowledge of the locations and spectral energy distributions of the few brightest stars in the FOV is helpful in establishing the possible presence of confusion bias, but the information is in general not likely to be available with sufficient accuracy to permit its removal. We discuss several ways of reducing the likelihood of confusion bias in crowded fields. Finally, several limitations of the present semi-analytic approach are reviewed, and their effects on the present results are estimated. The simple model presented here provides a good physical understanding of how confusion arises in a single SIM observation, and has sufficient precision to establish the likelihood of a bias in most cases., Comment: 28 pages, 20 figures, 1 table; to appear in December 2007 issue of PASP

Broadband Integrated Services Digital Network (R-ISDN) provides a range of narrowband and broad-band services for voice, video, and multimedia. Asynchronous Transfer Mode (ATM) has been selected by the standards bodies as the transfer mode for implementing B-ISDN; The ability to digitize images has lead to the prospect of reducing the physical space requirements, material costs, and manual labor of traditional film handling tasks in hospitals. The system which handles the acquisition, storage, and transmission of medical images is called a Picture Archiving and Communication System (PACS). The transmission system will directly impact the speed of image transfer. Today the most common transmission means used by acquisition and display station products is Ethernet. However, when considering network media, it is important to consider what the long term needs will be. Although ATM is a new standard, it is showing signs of becoming the next logical step to meet the needs of high speed networks; This thesis is a survey on ATM, and PACS. All the concepts involved in developing a PACS are presented in an orderly manner. It presents the recent developments in ATM, its applicability to PACS and the issues to be resolved for realising an ATM-based complete PACS. This work will be useful in providing the latest information, for any future research on ATM-based networks, and PACS.