Investigations on Structural Integrity of Piping Compensators Under Angular Rotational Deformation

The aim of this paper is to investigate the effect of angular rotational misalignment in pipe structure on the deflection based convolution stresses. Such stresses are generated in the thin walled unreinforced bellows compensators during the expansion-contraction function. On the convolution geometry, the most vulnerable stress type is meridional deflection stresses under the internal pressure. Therefore, it’s critical to check the structural integrity of pipe systems with bellows expansion joints, which typically connected to the process equipment’s including boilers, pressure vessels, reactors, heat exchangers, refineries, and so on. The findings of theoretical and experimental investigations of thin-walled unreinforced conditioned bellows subjected to different angular rotations are presented in this paper. The meridional deflection stresses are investigated for the different operating pressures when bellows subjected to angular rotations of 1°, 1.5° and 2° in the flexural plane. In addition, the testing is performed along various longitudinal lines across the periphery of the bellows to determine the maximum induced stress points on the convolution profile. The higher meridional stress is seen to be the bending stress at the bottom curved toroidal section of the convolution, which approaches towards the elastoplastic regime at 1° to 2° of angular deviation in flexural plane. These extreme stress points may prove the risky areas at the root of the convolution for the fatigue failures. Further, the results of the maximal convolution stress assessment are useful in predicting the structural integrity of bellows in elastic regime, when prone to the angular shift.

Modified Method to Detect the Turbulent Layers in the Atmospheric Boundary Layer for the Large Solar Vacuum Telescope

A method to detect the atmospheric turbulent layers using a single Shack–Hartmann wavefront sensor is discussed. In order to determine the height distribution of the atmospheric turbulence above a telescope, we register the wavefront distortions at different regions of the aperture from a single light solar object moving in time. Changes of the spatial position of the solar object on the sky give us the possibility to estimate the angular shift of an object. Cross-correlation analysis of the low-frequency component of wavefront slopes spaced on the telescope aperture at different times allows us to estimate characteristics for different atmospheric layers. Knowledge of the height profiles of atmospheric turbulence as well as the Fried parameter is critical for wide-field adaptive optics (AO).

Image Data Acquisition for Estimating Individual Trees Metrics: Closer Is Better

Background and Objectives: The recent use of Structure-from-Motion with Multi-View Stereo photogrammetry (SfM-MVS) in forestry has underscored its robustness in tree mensuration. This study evaluated the differences in tree metrics resulting from various related SfM-MVS photogrammetric image acquisition scenarios. Materials and Methods: Scaled tri-dimensional models of 30 savanna trees belonging to five species were built from photographs acquired in a factorial design with shooting distance (d = 1, 2, 3, 4 and 5 m away from tree) and angular shift (α = 15°, 30°, 45° and 60°; nested in d). Tree stem circumference at 1.3 m and bole volume were estimated using models resulting from each of the 20 scenarios/tree. Mean absolute percent error (MAPE) was computed for both metrics in order to compare the performance of each scenario in relation to reference data collected using a measuring tape. Results: An assessment of the effect of species identity (s), shooting distance and angular shift showed that photographic point cloud density was dependent on α and s, and optimal for 15° and 30°. MAPEs calculated on stem circumferences and volumes significantly differed with d and α, respectively. There was a significant interaction between α and s for both circumference and volume MAPEs, which varied widely (1.6 ± 0.4%–20.8 ± 23.7% and 2.0 ± 0.6%–36.5 ± 48.7% respectively), and were consistently lower for smaller values of d and α. Conclusion: The accuracy of photogrammetric estimation of individual tree attributes depended on image-capture approach. Acquiring images 2 m away and with 30° intervals around trees produced reliable estimates of stem circumference and bole volume. Research Highlights: This study indicates that the accuracy of photogrammetric estimations of individual tree attributes is species-dependent. Camera positions in relation to the subject substantially influence the level of uncertainty in measurements.

Study on the phase structure and mechanical properties of (Ti,Al,Si)N coatings deposited by multiarc ion plating

Different structural [Formula: see text] coatings were designed and deposited on WC-Co cemented carbide by the technology of multiarc ion plating. Monolayered [Formula: see text] coating was deposited using cathode of [Formula: see text]. Multilayered (Ti,Al)N/[Formula: see text] coating and [Formula: see text] coating with gradual silicon content were deposited using two cathodes of [Formula: see text] and [Formula: see text] simultaneously. The surface and cross-section morphology, compositions, and phase structure were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The dense [Formula: see text] coatings with droplets on the surface and without obvious columnar structure on the cross-sections were obtained. All coatings had the strong peaks of (200) orientation. The different angular shift occurred with different combination of cathodes and processes. The introduction of multilayered and gradient structure effectively reduced the lattice distortion of coatings. Meanwhile, the coating-substrate adhesion strength increased from 38.57 N to 60.17 N with a coating thickness of approximately 3.5 [Formula: see text]m by scratch tests. The highest hardness of [Formula: see text] coating obtained in this paper were [Formula: see text] GPa by nanoindentation. The multilayered coating showed better toughness.

APLIKASI SENSOR PVDF UNTUK PENGUKURAN PERGESERAN SUDUT

In this paper we will present the results of the study at the application of Polyvinylidene Fluoride (PVDF) sensors to determine the value of angular shift. In the study carried out the loading on the PVDF sensor so that the PVDF film on the sensor changes in the form of angular shift. For every angle shift that occurs then the sensor will detect in the form of output current on the display. The sensor loading is done for the angle change ranges from 100 to 800. From the research results show that the sensor output shows a mathematical relationship between the magnitude of the angular shift with the resulting current. The mathematical relationship is expressed in terms of exponential equations. This clearly indicates that this PVDF sensor can work well in detecting large angular changes.

Study of Computational Theory of Surface Plasmon Resonance (SPR) for Porcine Gelatin Detected Sensor Based Nanomaterial Fe3O4–CNT in Otto’s Configuration

Accurate biomolecular detection can be performed through the Surface Plasmon Resonance (SPR) phenomenon. This study was conducted to determine the effect of the addition of Fe3O4 and Carbon Nanotube (CNT) nanomaterials in the Otto configurations and their use as porcine detection sensors. The research was conducted theoretically by finding the equation of reflectance and computationally using Matlab software version 7.12.0 to know SPR angle and reflectance value. This research uses ATR method with Otto configuration. The modeling was finished using HeNe laser light on 632.8 nm wavelength, semi-circle prism type BK7, metal layer of gold nanoparticles. The results of the research can be used in the detection of porcine gelatin by Otto configurations. The best air gap thickness is 30 nm. The best thickness of the gold layer and Fe3O4 layer are 50 nm and 0.05 nm. The applied of MWCNT nanoparticles is not effective in the detection of biomolecules based SPR. While the thickness of SWCNT used is 1 nm. The SWCNT material also proved to be better used in SPR systems. The addition of porcine gelatin layer in the system shows a graphic change in the form of increasing reflectance value and SPR angular shift.

Angular velocity integration in a fly heading circuit

Many animals maintain an internal representation of their heading as they move through their surroundings. Such a compass representation was recently discovered in a neural population in the Drosophila melanogaster central complex, a brain region implicated in spatial navigation. Here, we use two-photon calcium imaging and electrophysiology in head-fixed walking flies to identify a different neural population that conjunctively encodes heading and angular velocity, and is excited selectively by turns in either the clockwise or counterclockwise direction. We show how these mirror-symmetric turn responses combine with the neurons’ connectivity to the compass neurons to create an elegant mechanism for updating the fly’s heading representation when the animal turns in darkness. This mechanism, which employs recurrent loops with an angular shift, bears a resemblance to those proposed in theoretical models for rodent head direction cells. Our results provide a striking example of structure matching function for a broadly relevant computation.