Edge Portion Research Articles

Real-time in situ observation of extended defect evolution near a crack tip in GaSb crystal under thermal loading

When an AlAsSb/InAs superlattice semiconductor material is grown by molecular beam epitaxy, extended defects in the GaSb buffer layer are inevitable. Therefore, the study the formation and evolution of extended defects is considerably important. In this study, a crack tip located in the buffer layer was considered. The evolution process of nucleation as well as development and extinction of two extended defects on the (1 1 −1) and (−1 1 −1) faces were observed in real time in situ by scanning transmission electron microscopy during heating. Analysis of the stress field results showed that thermal stress is the driving force for the propagation of extended defects, which promotes the nucleation and evolution of the (1 1 −1) and (−1 1 −1) surface extended defects. The variation in crack width before and after heating was measured according to the intensity of the atomic and crack regions in the high-resolution STEM-BF image. The results showed that the crack closes after heating at a high temperature compared to room temperature. It is considered that the amorphous GaSb at the crack tip and the edge portion at the nanometer scale during the heating process is transformed into a single crystal, thus causing the crack to shrink.

Valve of Rosenmüller: Endoscopic Real-Time Analysis of Two Subtypes and Potential Functional Implications.

The aim of this study was to examine the endoscopic anatomy of the valve of Rosenmüller in real-time and its potential functional implications. High-definition endoscopic documentation of the valve of Rosenmüller (VOR) during 50 powered endoscopic dacryocystorhinostomy over a period of 2 years were reviewed. The presence or absence of the valves were assessed and when present, each of the valves were studied for their anatomical configuration, shape, precise location, and changes with opening and closing of the internal common opening (ICO) and with the presence and absence of the probe. VOR was noted in 68% of the subjects studied and 2 distinct subtypes were noted with type I being more common. The Type 1 VOR was a stand-alone, freely mobile, elliptical valve arising from the superior or postero-superior portion of the medial edge of the ICO. The Type II VOR was a group of a superior and inferior mucosal fold, arising from the superior and inferior portions of the medial edge of the ICO. When the ICO opens slowly, the valve tends to fall outwards towards the lacrimal sac. When the ICO slowly closes back, the valve moves inward towards the common canaliculus. This is the first study to demonstrate the in-vivo presence of VOR. Two different types of VOR were noted with characteristic shapes, locations, and movements of each. Where present, VOR fulfills the criteria of a true valve. The study proposes that the term "valve of Huschke" is a misnomer and when present, is actually part of the overall anatomical and functional unit of VOR.Detailed anatomical features of the valve of Rosenmϋller can help our understanding of the focal anatomy and tear rheology.

Moving Surface Boundary Layer Technique For NACA 0012 Airfoil At Ultra-Low Reynolds Number

Application of moving surface boundary layer control technique has been confined to relatively high Reynolds numbers. The present paper reports a numerical study of application of the above flow technique in the ultra-low Reynolds number range. A two dimensional incompressible unstructured grid based Navier Stokes solver has been used for conducting the numerical studies. Moving surface has been applied at three different portions on the airfoil surface, firstly, in the form of a rotating leading edge portion of the airfoil, secondly, a continuous moving surface from leading edge of airfoil to 57% of the chord along the leeward surface of the airfoil and thirdly a continuous moving surface from leading edge to 97% of the chord along the leeward surface of the airfoil. All the moving surface configurations show improvement of aerodynamic performance of the airfoil through enhancement of lift and decrement of drag as compared to a fixed surface one.

ITUG and TUG with dual task for falls risk in stroke patients

The synthesis of TiO2 nanotubular films is presented together with their physical, chemical, electrochemical and photoelectrochemical characterization in order to assess their use as photocatalyst. The synthesis was made through the anodic oxidation procedure using an inorganic fluoride based electrolyte. The nanotubes presented an inner diameter of 54 nm, a wall thickness of 18 nm and a length of 570 nm in amorphous condition. After annealing at 500 °C the alignment and definition of the nanotubes were improved observing more space between the nanotubes, contrary to that observed at 700 °C, in which a detrimental morphology was seen, presenting a disruption of a little portion of the superior edge of the nanotubes. The electrochemical characterization was made for four samples: the amorphous one and two crystallized samples at 500 (TNTC-5) and 700 °C (TNTC-7) and for Ti. The TNTC-5 (constituted by anatase-rutile) which improved its morphology and kept its mechanical strength after annealing, presented the best electrochemical stability after 5 days of exposure. In conclusion, TNTC-5 sample showed to be a good candidate for photocatalysis processes due to: (i) its better ordered 1D nanostructure geometry with longer nanotubes after annealing compared to that of the TNTC-7 sample, which conferred an increase of surface area, (ii) due to short length nanotubes, since better efficient light absorption and fast carrier transport is expected, and thus less unwanted recombination losses, (iii) its chemical structure composition of anatase-rutile in comparison to that at 700 °C that transformed completely in rutile, (iv) a clean top surface, (v) the preservation of stable morphology after exposing to corrosive electrolytes in long term showing a high corrosion stability and (vi) its major and stable photocurrent density.

CLBM: Controlled load-balancing mechanism for congestion management in silicon interposer NoC architecture

Abstract Multiple memory stacks can be integrated with a processor chip in the silicon interposer technology (“2.5D” stacking). In 2.5D architecture, there are two different network layers for both coherence and memory traffic. The CPU layer is used for coherence Core-to-Core traffic, while the interposer layer is associated with Core-to-Memory blocks traffic regularly. A load balancing strategy balances the traffics on the two network layers and optimizes the resources utilization. In the aforementioned strategy, after detecting congestion in the CPU layer, packets can be moved to the interposer one. It can be concluded that this transferring encounters the bottleneck of the edge portion that is connected to memory blocks. In this paper, we propose a Controlled Load Balancing Mechanism (CLBM) which efficiently controls bottleneck in load balancing methods. As a result, the CLBM selects an appropriate network based on the destination address without comparing latencies of two networks. Moreover, a multicast fault-tolerant ring is introduced to propagate network congestion information. The experimental results showed that, as compared with the absence of load balancing method and traditional load balancing strategy, our CLBM strategy achieves 37.82% and 17.22% average latency improvements and 22.19% and 8.55% average total power with minor overhead.

Synthesis of TiO2 nanotubular arrays and their electrochemical and photoelectrochemical properties to determine their use in photodegradation processes

The synthesis of TiO2 nanotubular films is presented together with their physical, chemical, electrochemical and photoelectrochemical characterization in order to assess their use as photocatalyst. The synthesis was made through the anodic oxidation procedure using an inorganic fluoride based electrolyte. The nanotubes presented an inner diameter of 54 nm, a wall thickness of 18 nm and a length of 570 nm in amorphous condition. After annealing at 500 °C the alignment and definition of the nanotubes were improved observing more space between the nanotubes, contrary to that observed at 700 °C, in which a detrimental morphology was seen, presenting a disruption of a little portion of the superior edge of the nanotubes. The electrochemical characterization was made for four samples: the amorphous one and two crystallized samples at 500 (TNTC-5) and 700 °C (TNTC-7) and for Ti. The TNTC-5 (constituted by anatase-rutile) which improved its morphology and kept its mechanical strength after annealing, presented the best electrochemical stability after 5 days of exposure. In conclusion, TNTC-5 sample showed to be a good candidate for photocatalysis processes due to: (i) its better ordered 1D nanostructure geometry with longer nanotubes after annealing compared to that of the TNTC-7 sample, which conferred an increase of surface area, (ii) due to short length nanotubes, since better efficient light absorption and fast carrier transport is expected, and thus less unwanted recombination losses, (iii) its chemical structure composition of anatase-rutile in comparison to that at 700 °C that transformed completely in rutile, (iv) a clean top surface, (v) the preservation of stable morphology after exposing to corrosive electrolytes in long term showing a high corrosion stability and (vi) its major and stable photocurrent density.

RNA Sequencing Characterizes Transcriptomes Differences in Cold Response Between Northern and Southern Alternanthera philoxeroides and Highlight Adaptations Associated With Northward Expansion.

Alternanthera philoxeroides recently expanded its range northwards in China. It is unknown if the range expansion has a genetic and/or epigenetic basis, or merely an environmental basis due to a warming climate. To test these possibilities, we used an RNAseq approach with a common greenhouse design to examine gene expression in individuals from the northern edge and central portion of alligator weed range from China to determine if there were differences in their responses to cold temperatures. We hypothesized that if the recent range expansion was primarily environmental, we would observe few differences or only differences unrelated to low-temperature adaptations. We assembled over 75,000 genes of which over 65,000 had long open reading frames with similarity to sequences from arabidopsis. Differences in expression between northern and southern populations that were both exposed to low temperatures showed similar expression among genes in the C-REPEAT/DRE BINDING FACTOR (CBF) regulon. However, gene set and sub-network enrichment analysis indicated differences in the response of photosynthetic processes and oxidative stress responses were different between the two populations and we relate these differences to cold adaptation. The transcriptome differences in response to cold between the individuals from the two populations is consistent with adaptations potentiating or resulting from selection after expansion into colder environments and may indicate that genetic changes have accompanied the recent northward expansion of A. philoxeroides in China. However, we cannot rule out the possibility of epigenetic changes may have a role in this expansion.

Stimulus- and Response-locked Posterior Contralateral Negativity Bisect Cognitive Operations in Visual Search.

We explored the flow of information during visual search by examining activity indexing visual attention (N2pc) and the subsequent processing of the selected objects in visual short-term memory (SPCN) time-locked to stimulus presentation and to the motor response. We measured event-related activity at posterior sites (PO7/PO8) for 96 participants during a simple visual search task. A response-locked posterior contralateral negativity (RLpcN) was observed with a scalp distribution similar to that of the N2pc and SPCN. The RLpcN was compared with the stimulus-locked activity (N2pc and SPCN) across experimental manipulations (targets were either closer or farther from fixation in visual space, and the response was either more frequent [75%] or less frequent [25%]) and across response speeds (EEG data were separated into tertiles by RT both within-subjects and between-subjects). The leading edge and early portion of the RLpcN appeared to reflect the initial deployment of attention (N2pc), whereas the later portion (up to peak amplitude) reflected subsequent processing of visual information (SPCN). SPCN and RLpcN also had similar modulations in amplitude for both analyses. Moreover, whereas very small N2pc and SPCN onset latency differences were observed when data were separated into tertiles by RT, there were large onset differences for the RLpcN, with earlier RLpcN onsets for longer RTs, suggesting that RT variance is in large determined by processing after the initial deployment of attention. The results show how we can bisect processing responsible for variations in RT relative to the onset of visual spatial attention.

A silencer incorporated within the thickness of the edge of the door for increasing sound transmission loss.

The present study focuses on a silencer built within the thick portion of a door edge and reports on the results of evaluating silencers by determining sound transmission loss via theoretical analysis and experiments on three types of silencers. The theoretical analysis involved determining the calculated values of sound transmission loss obtained using the transfer matrix method. The change in cross-sectional shape was analyzed by elemental division of the transfer matrix. Using the above, simulations were performed with respect to the optimum shape of the silencer. These theoretical analyses were then compared with the measurement results. Furthermore, the study includes the results of an experiment that attempted to restrain the dip in sound transmission loss by adding a non-woven fabric to the opening of the silencer. In a side branch silencer with an increasing shape wherein the longitudinal cross-section is a linear or an exponential function, the peak of the transmission loss was shifted to the lower frequency side when compared with that in the case of a rectangular side branch silencer. Furthermore, in comparisons between the two, the sound attenuation peak frequency was lower in the case of the exponential shape. The resonance of the side branch was suppressed by adding a non-woven fabric to the opening of the side branch silencer. As a result, the peak and dip of sound attenuation were alleviated, and the sound attenuation characteristics could be adjusted.

Sound radiation of a beam with a wedge-shaped edge embedding acoustic black hole feature

As a potential intelligent structure which is capable of concentrating energy into local area, the Acoustic Black Hole (ABH) structure has high potential of application for sound radiation control. The ABH effect is caused by the infinitely small material attenuation in an inhomogeneous medium, such as the wedge-shaped beam with a diminishing thickness, giving rise to the reduction in the bending wave speed and no wave reflections in the tip. Therefore, the waves will be trapped in the edge portion. This paper investigates sound radiation problems of a beam embedding an ABH feature, focusing on characterizing and improving the low frequency performance of the beam on sound radiation reduction. The ABH beam is modeled and solved by transfer matrix method (TMM). Analytical solutions of vibration, wavenumber domain analysis and acoustic radiation phenomena are presented. A critical mode with very high order of the ABH beam is found, resulting in that its radiation efficiency is lower than that of the uniform beam in a specified range of frequencies. Generally, the low frequency performance will be improved effectively by enhancing the interaction between the bending waves and ABH element.

Estimations of Nitrogen Concentration in Sugarcane Using Hyperspectral Imagery

This study aims to estimate the spatial variation of sugarcane Canopy Nitrogen Concentration (CNC) using spectral data, which were measured from a spaceborne hyperspectral image. Stepwise Multiple Linear Regression (SMLR) and Support Vector Regression (SVR) were applied to calibrate and validate the CNC estimation models. The raw spectral reflectance was transformed into a First-Derivative Spectrum (FDS) and absorption features to remove the spectral noise and finally used as input variables. The results indicate that the estimation models developed by non-linear SVR based Radial Basis Function (RBF) kernel yield the higher correlation coefficient with CNC compared with the models computed by SMLR. The best model shows the coefficient of determination value of 0.78 and Root Mean Square Error (RMSE) value of 0.035% nitrogen. The narrow sensitive spectral wavelengths for quantifying nitrogen content in the combined cultivar environments existed mainly in the electromagnetic spectrum of the visible-red, longer portion of red edge, shortwave infrared regions and far-near infrared. The most important conclusion from this experiment is that spectral signals from the space hyperspectral data contain the meaningful information for quantifying sugarcane CNC across larger geographic areas. The nutrient deficient areas could be corrected by applying suitable farm management.

Analysis on vibration energy concentration of the one-dimensional wedge-shaped acoustic black hole structure

The transverse vibration energy of a plate with a wedge-shaped profile can be trapped by acoustic black hole effect to its edge portion, in case the wedge thickness is diminished according to the power-law h( x) = εxm with m ≥ 2.0. The acoustic black hole effect exhibits potential ability for passive vibration control and energy harvesting. In this article, the transfer matrix method is adopted to establish and solve the dynamical model of acoustic black hole structure. Energy ratio is defined as a ratio of the energy trapped within the edge portion to that of the whole wedge, to illustrate the energy concentration effect. Analyses show that both the strain energy ratio and kinetic energy ratio of the acoustic black hole structure achieve the minimum when the wedge is in resonances, although these two kinds of energy come to peaks at this case. However, in the case of small length of the edge portion, the strain energy ratio reaches the highest peaks at the second and higher resonances, rather than at the first one. Generally, the best effect of energy concentration occurs when m ranges from 2.5 to 3.0. Reducing the truncation thickness and increasing the maximum height can improve the energy trapping.

Report on Load Resistant Capacity when Promoting Curing PC Beam Specimens Affected by Alkali Silica Reaction

In this paper, ｍade a PC beam specimen using ASR reactivity aggregate made in Chinese Zhejiang Ministry and made them do an accelerated curing and the influence by which swell of ASR reactivity aggregate gives it to a PC beam specimen was evaluate. Moreover the PC beam specimen which degraded by swell was classified every degradation grade, a loading test was put into effect and the load carrying capacity was inspected. As a result, I got the following conclusion. ①The thing which classifies the degradation grade into 3 stages (incubation period, acceleration period and degradation period) from the accelerated curing results of the test piece performed in advance. In the incubation period, it was confirmed that the compressive strength and the modulus of static elastic tend to increase more than before accelerated curing. ②Expansion of PC beam specimen was inflated from the upper edge part with less influence of prestress, Moreover as the expansion stabilized, the tendency of the lower edge portion which is highly affected by the prestress to expansion could be confirmed from the strain behavior by monitoring.In addition, with expansion of the lower edge part the prestress amount of the PC steel material placed inside the PC beam specimen (The lower edge position) is increasing and as the prestress amount stabilizes the tendency of expansion of the lower edge part is stabilized can also be confirmed. ③When accelerated curing was further promoted, the expansion of the upper edge and lower edge turned to a decreasing trend, and it was confirmed that stabilize tendency at about 25 to 35% of the maximum expansion. ④The P-δ curve up to fracture was measured for PC beam specimen before accelerated curing and ② to ③. As a result, it was not possible to confirm a large difference at the P-δ curve before accelerated curing and ②, but a significant decrease in load bearing capacity was confirmed at ④.

Blind Deconvolution for Image Deblurring Based on Edge Enhancement and Noise Suppression

This paper denotes to obtain an accuracy blur kernel and a shape image. An efficient method that blind deconvolution for image deblurring based on edge enhancement and noise suppression is proposed. First, we exploited an edge detection method to extract the strong edge portion of blurred image. Then, the blurred image was divided into weak edge portion and strong edge portion. At this time, we apply a trilateral filter method to suppress the noise in the weak edge portion. Through mathematical operations for weak edge portion and strong edge portion, we can obtain the new blurred image which as the input of blur kernel estimation. At the phase of the kernel estimation, the problem can be solved via alternate between <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> updating. In addition, we utilize improved fast iterative shrinkage thresholding algorithm method to solve the optimization problem. Finally, non-blind deconvolution was employed at the phase of image recovery. A comprehensive evaluation shows that our approach achieves state-of-the-art results for uniformly blurred images.

Simulation Based Study of Oxygen Plasma Induced Defects on Zigzag Graphene Nanoribbons

This work investigates the design issues and insights of the graphene interconnects with the defects stemming from oxygen plasma etching. Zigzag graphene nanoribbons (ZGNRs) with an odd number of zigzag chains show a unique linear I-V characteristic, suitable for interconnect application. However, the common etching method, oxygen plasma, for ZGNRs could introduce defects, leading to carrier transport degradation. This work is aimed to understand the issue and seek for a solution for the practical use of ZGNRs. The completed structure for transport calculation is composed of the central region, and left/right electrode, as shown in Fig. 1 where, from top to bottom, the three structures represent for edge-roughness, oxygen-on-edge, and sp3-type oxygen defects, respectively. The structures are first optimized until the atomic force falls below 0.01 eV/Å. After the optimization processes, we apply density functional theory (DFT) and non-equilibrium Green’s function (NEGF) to evaluate materials and transport properties. In NEGF calculation, the transmission coefficients are obtained from the retarded Green’s function, and then the I-V values can be obtained through the integration of transmission coefficients based on the electrochemical potentials, electron temperatures, and applied voltages of the left and right electrodes. The I-V characteristics of the edge-roughness and oxygen-on-edge structures are shown in Fig. 2. Compared to ideal N=3 case (atom chains), both of the two cases lose their linear I-V characteristics, and their characteristics are almost identical. An extra unit cell on edge gives the similar effect as the oxygen atom does. Transmission eigenstates, pathways and the device density of states (DDOS) are analyzed for understanding the physical mechanism. In Fig. 3, there is nearly zero state around the extra unit cell and oxygen, so carriers have no state to transport through, like being blocked. As indicated in Fig. 4, the carbon atom bonded to the oxygen has almost no DDOS existing at the Fermi level. By contrast, the ideal case has a large peak at Fermi level for the carbon atom at the same position. Next, the I-V characteristic of the sp3-type oxygen defect is shown in Fig. 5. After optimization, the oxygen is located between the two carbons of the ZGNR and forms the sp3 bonds. This sp3-type oxygen defect breaks the pi-bond system of graphene, and makes the smooth surface wrinkled and uplifted. This deformation significantly degrades the transport properties of the ZGNR, and leads to severe I-V degradation. After evaluating how these defects impact the transport properties, the practical design methodology is further provided. In fact, the I-V characteristic of the ideal odd-row ZGNR is not dependent on its width. Nonetheless, it does change with width for non-ideal cases. Fig. 6 shows that as the width changes from N=3 to 9, the linearity of I-V characteristics recovers. However, when the width exceeds N=9, the I-V characteristics lose the linearity again. We suggest the choice of width no more than N=9 for better linearity and limited interconnect area. For the sp3-type oxygen defect, because the edge portion occupies a big ratio of ZGNR transport, the near-middle case shows better result than the near-edge case with an incredible linearity and current value, which is very close to the ideal one, as shown in Fig. 7. It is essential for the ribbon edge to be treated with some optimized process to clean up the oxygen atoms. An interesting transport result is found when the multiple defects exist on the opposite edges. In Fig. 8, compared to the one-oxygen case, all multiple-defect cases show the recovery of linearity. Two-unit-cell and two-oxygen cases show similar I-V characteristics again. Considering the unique similarity between the extra unit cell and oxygen, this multiple-defect recovery mechanism can be used to design an oxygen-tolerance ZGNR interconnect. The odd-row ZGNR has an asymmetry structure; an extra unit cell can be just located at the symmetry site of oxygen, as shown in Fig. 9. This structure has a dramatic I-V recovery and nice I-V linearity, being very close to the ideal case. The result proves that the extra-unit-cell design can help recover the degradation of I-V characteristic by oxygen atom adsorption on edge. Figure 1

Film Cooling Performance of Tripod Antivortex Injection Holes Over the Pressure and Suction Surfaces of a Nozzle Guide Vane

Film cooling performance of the antivortex (AV) hole has been well documented for a flat plate. The goal of this study is to evaluate the same over an airfoil at three different locations: leading edge suction and pressure surface and midchord suction surface. The airfoil is a scaled up first stage vane from GE E3 engine and is mounted on a low-speed linear cascade wind tunnel. Steady-state infrared (IR) technique was employed to measure the adiabatic film cooling effectiveness. The study has been divided into two parts: the initial part focuses on the performance of the antivortex tripod hole compared to the cylindrical (CY) hole on the leading edge. Effects of blowing ratio (BR) and density ratio (DR) on the performance of cooling holes are studied here. Results show that the tripod hole clearly provides higher film cooling effectiveness than the baseline cylindrical hole case with overall reduced coolant usage on the both pressure and suction sides of the airfoil. The second part of the study focuses on evaluating the performance on the midchord suction surface. While the hole designs studied in the first part were retained as baseline cases, two additional geometries were also tested. These include cylindrical and tripod holes with shaped (SH) exits. Film cooling effectiveness was found at four different blowing ratios. Results show that the tripod holes with and without shaped exits provide much higher film effectiveness than cylindrical and slightly higher effectiveness than shaped exit holes using 50% lesser cooling air while operating at the same blowing ratios. Effectiveness values up to 0.2–0.25 are seen 40-hole diameters downstream for the tripod hole configurations, thus providing cooling in the important trailing edge portion of the airfoil.

Formation mechanism and kinetic analysis of the morphology of Cu6Sn5 in the spherical solder joints at the Sn/Cu liquid–solid interface during soldering cooling stage

The morphology evolution mechanism and dynamics of Cu6Sn5 intermetallic compound (IMC) in cooling stage were studied by using pure Sn solder ball with a diameter of 1 mm to react with polycrystalline Cu substrate and form Cu6Sn5. A nearly uniform height of the scallop-like IMC grains is attained by using high pressurized air to remove excess liquid solder (that is, for acquisition of the IMC morphology identical to heat preservation stage). But the morphology evolution of IMC in the solder joint was greatly affected by the cooling phase of interfacial reaction, and IMC morphology partition phenomenon was found in the spherical joints. The IMC at the edge portion characterized scallop morphology whereas the central portion possessed prismatic shape morphology. Finite element simulation for the temperature field distribution in the solder ball-substrate domain showed temperature gradient in solder’s internal core was significantly greater than that at the edge. Using this simulation results with kinetic equations, it could be understood that the central core region is conducive to the formation of small plane structure morphology. These small planes would eventually form the prismatic morphology IMC in the central region. As the soldering temperature increases, the area ratio of IMC with scallop-like morphology to the prismatic shaped IMC reduced from 0.2178 down to 0.1680. Moreover, for an elevated temperature of 300 °C, it is observed that the central region IMC (with prismatic structure) grows upto an average thickness of 7.7245 μm, whereas the thickness value for scalloped IMC at the edge portion is around 4.556 μm.

Turbine Blade Platform Film Cooling With Simulated Swirl Purge Flow and Slashface Leakage Conditions

The combined effects of inlet purge flow and the slashface leakage flow on the film cooling effectiveness of a turbine blade platform were studied using the pressure-sensitive paint (PSP) technique. Detailed film cooling effectiveness distributions on the endwall were obtained and analyzed. Discrete cylindrical film cooling holes were arranged to achieve an improved coverage on the endwall. Backward injection was attempted by placing backward injection holes near the pressure side leading edge portion. Experiments were done in a five-blade linear cascade with an average turbulence intensity of 10.5%. The inlet and exit Mach numbers were 0.26 and 0.43, respectively. The inlet and exit mainstream Reynolds numbers based on the axial chord length of the blade were 475,000 and 720,000, respectively. The coolant-to-mainstream mass flow ratios (MFR) were varied from 0.5% and 0.75% to 1% for the purge flow. For the endwall film cooling holes and slashface leakage flow, blowing ratios (M) of 0.5, 1.0, and 1.5 were examined. Coolant-to-mainstream density ratios (DR) that range from 1.0 (close to low temperature experiments) to 1.5 and 2.0 (close to engine conditions) were also examined. The results provide the gas turbine engine designers a better insight into improved film cooling hole configurations as well as various parametric effects on endwall film cooling when the inlet (swirl) purge flow and slashface leakage flow were incorporated.

OPTIMALISASI EDITING GREEN SCREEN MENGGUNAKAN TEKNIK LIGHTING PADA CHROMA KEY

In the film world greenscreen or bluescreen is already widely in use as a background making technology . Utilization of this technology is very great because filmmakers can imagine changing the background to the shape or the desired atmosphere without having to perform image capture directly to the location . Chroma key is a technique for combining two images made with a video camera as well , in which a background color of an image to remove (made transparent ) , was replaced by another image behind it. Deficiencies that exist in the chroma key is that at the time of editing of the hair . Here the author tries to do research on how to minimize the weaknesses mengilangkan edge portion of hair at the time of editing green screen by optimizing lighting / lighting .

Restoration of forest soil and vegetation 15 years after landslides in a lower zone of mountains in temperate climates

The study analysed the variability of physical, chemical and biological properties of soil cover recovering fifteen years after a landslide. The soil properties were studied on a regular grid of points, which covered the entire area of the landslide of 0.50ha. In 23 soil samples pH, sorption properties, total carbon and nitrogen content, microbial biomass carbon and nitrogen, activity of dehydrogenases and β-glucosidase, particle size and distribution and water resistance of soil aggregates were determined. Apart from detailed soil characteristics, in the test points the development of vegetation, its species composition, cover in each layer and tree species biomass were examined. On the basis of the level of soil cover with vegetation, canopy interception was calculated. It was found, that the landslide area is characterised by a stronger diversification of physical, chemical and biological properties in comparison to soils of the neighbouring forest stands (control points). As far as physical properties are concerned, the landslide area is characterised by a strongly diversified of clay fraction, level of soil aggregate development and their water resistance. The diversification of the physical properties is linked to a different accumulation of the organic substance and biochemical activity of the restoring soil cover. Locations with the highest abundance of clay fraction located in the upper part of the landslide niche and the lowest, edge portion of the landslide, are at the same time characterised by a lack of organic matter and low activity of soil enzymes. Contrary to those, the landslide fragments, which contain higher content of organic carbon, are characterised by a lower abundance of fine fractions and higher enzymatic activity. It was determined, that the soil recovery level determines the intensity of plant cover development, which in turn determines the correct level of interception while at the same time ensuring protection of the forming soil against the destructive effect of water erosion.