Load Capacity of Eccentric Roller Bearings

Eccentric roller bearings are commonly used in engineering and serve as actuating links in mechanical drives of various machines. Load capacity is one of the main parameters of such bearings. This paper presents possible kinematic schemes of an eccentric roller bearing and the specifics of the actual radial load distribution when it is applied to the driving ring between the rolling bodies. It is established that the load capacity of the eccentric roller bearing depends on the actual stress occurring when the rolling body of the minimal radius and the inner ring raceway are in contact. Equations are obtained for calculating the permissible radial load that the rolling body of the minimal radius with a raceway can bear. The limiting load is determined that satisfies the conditions of contact strength of the bearing’s assembly units and ensures performance of the bearing in a mechanical drive of a machine. The results of determining the limiting load of the eccentric roller bearing and the results’ analysis are presented using a specific example. To ensure the performance of the bearing, the optimal ratio of the inner ring radius to the minimum rolling body radius is determined.

Time Optimal Trajectories for a Mobile Robot Under Nonsliding and Radius-of-Turn Constraints

The time-optimal path problem for a point mass mobile robot is considered. Given initial and target states, we seek the time optimal path subject to the following constraints: (1) A limitation on its maximal linear acceleration; (2) a speed-dependent nonsliding condition; and (3) a minimal radius of turn. The paper formulates and analyzes the time optimal path problem using standard optimal control formulation with extensive use of the classical Hodograph method. Based on the analysis, the time optimal path consists of five path primitives. Numerical solutions are obtained to support and illustrate the analysis.

PENGGUNAAN ALGORITMA TRANSFORMASI HOUGH UNTUK PROTOTYPE APLIKASI MOBILE PERHITUNGAN JUMLAH PIPA PADA BAGIAN GUDANG PT SPINDO Tbk

Dalam perusahaan pipa baja, ujung dari pipa berbentuk lingkaran, untuk itu dibutuhkan suatu aplikasi agar dalam proses perhitungan jumlah pipa dapat lebih efektif. Dalam sistem ini dibutuhkan suatu citra RGB dari pengambilan ujung pipa yang terdapat objek lingkaran, kemudian diubah menjadi citra grayscale dan selanjutnya diikuti 4 proses lainnya yaitu : operasi morfologi dengan teknik dilasi agar objek lingkaran dapat terlihat lebih jelas, deteksi tepi menggunakan metode canny untuk memperbaiki detail dari citra yang blur serta mengurangi noise, selanjutnya deteksi lingkaran menggunakan algoritma transformasi hough agar objek lingkaran dalam citra dapat terdeteksi berdasarkan nilai minimal radius dan maksimal radius yang sudah diatur, dari deteksi tersebut menghasilkan sebuah identifier yang diinisialisasikan menjadi variabel untuk digunakan dalam proses perhitungan jumlah objek lingkaran pipa menggunakan looping. Hasil dari sistem ini berupa citra awal, citra hasil deteksi dan jumlah pipa yang terdeteksi. Nilai rata-rata dari deteksi objek lingkaran pipa tersebut adalah 87,36%.

Thermodynamics of the Bardeen black hole in anti-de Sitter space

In this paper, we study thermodynamics of the regular black holes with Bardeen–AdS black hole. The cut-off radius which is the minimal radius of the stable Bardeen–AdS black hole has been obtained from temperature and heat capacity analysis, respectively. Moreover, the thermodynamical stability of the Bardeen–AdS black hole is learned by the Gibbs free energy and the heat capacity. In this work, we find similar properties to the van der Waals liquid-gas system.

Concentration with a single sign-changing layer at the higher critical exponents

We exhibit a new concentration phenomenon for the supercritical problem-\Delta v=\lambda v+|v|^{p-2}v\quad\text{in }\Omega,\qquad v=0\quad\text{on }% \partial\Omega,as {p\rightarrow 2_{N,m}^{\ast}} from below, where {2_{N,m}^{\ast}:=\frac{2(N-m)}{N-m-2}}, {1\leq m\leq N-3}, is the so-called {(m+1)}-th critical exponent. We assume that Ω is of the form\Omega:=\bigl{\{}(x_{1},x_{2})\in\mathbb{R}^{m+1}\times\mathbb{R}^{N-m-1}:(|x_% {1}|,x_{2})\in\Theta\bigr{\}},where Θ is a bounded smooth domain in {\mathbb{R}^{N-m}} such that {\overline{\Theta}\subset(0,\infty)\times\mathbb{R}^{N-m-1}}. Under some symmetry assumptions, we show that there exists {\lambda_{\ast}\geq 0} such that for each {\lambda\in(-\infty,\lambda_{\ast})\cup\{0\}}, there exist a sequence {p_{k}\in(2,2_{N,m}^{\ast})} with {p_{k}\rightarrow 2_{N,m}^{\ast}} and a sequence of solutions {v_{k}} which concentrate and blow up along an m-dimensional sphere of minimal radius contained in {\partial\Omega}, developing a single sign-changing layer as {p_{k}\rightarrow 2_{N,m}^{\ast}}. In contrast with previous results, the asymptotic profile of this layer on each space perpendicular to the blow-up sphere is not a sum of positive and negative bubbles, but a rescaling of a sign-changing solution to the critical problem-\Delta u=|u|^{{4}/({N-m-2})}u,\quad u\in D^{1,2}(\mathbb{R}^{N-m}).Moreover, {\lambda_{\ast}>0} if {m\geq 2}.

Intermittent Pringle maneuver may be beneficial for radiofrequency ablations in situations with tumor-vessel proximity

BackgroundRadiofrequency ablation (RFA) represents a treatment option for non-resectable liver malignancies. Larger ablations can be achieved with a temporary hepatic inflow occlusion (Pringle maneuver – PM). However, a PM can induce dehydration and carbonization of the target tissue. The objective of this study was to evaluate the impact of an intermittent PM on the ablation size.MethodsTwenty-five multipolar RFAs were performed in porcine livers ex vivo. A perfused glass tube was used to simulate a natural vessel. The following five test series (each n=5) were conducted: (1) continuous PM, (2–4) intermittent PM, and (5) no PM. Ablations were cut into half. Ablation area, minimal radius, and maximal radius were compared.ResultsNo change in complete ablation size could be measured between the test series (p>0.05). A small rim of native liver tissue was observed around the glass tube in the test series without PM. A significant increase of ablation area could be measured on the margin of the ablations with an intermittent PM, starting without hepatic inflow occlusion (p<0.05).ConclusionAn intermittent PM did not lead to smaller ablations compared to a continuous or no PM ex vivo. Furthermore, an intermittent PM can increase the ablation area when initial hepatic inflow is succeeded by a PM.

Bottom-up Evolution from Disks to High-Genus Polymersomes

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

Bottom-up Evolution from Disks to High-Genus Polymersomes

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

On the horseshoe conjecture for maximal distance minimizers

We study the properties of sets Σ having the minimal length (one-dimensional Hausdorff measure) over the class of closed connected sets Σ ⊂ ℝ2 satisfying the inequality maxy∈M dist (y,Σ) ≤ r for a given compact set M ⊂ ℝ2 and some given r > 0. Such sets play the role of shortest possible pipelines arriving at a distance at most r to every point of M, where M is the set of customers of the pipeline. We describe the set of minimizers for M a circumference of radius R > 0 for the case when r < R ∕ 4 .98, thus proving the conjecture of Miranda, Paolini and Stepanov for this particular case. Moreover we show that when M is the boundary of a smooth convex set with minimal radius of curvature R, then every minimizer Σ has similar structure for r < R ∕ 5. Additionaly, we prove a similar statement for local minimizers.

Sistem Pentautan Citra Udara Menggunakan Algoritme SURF dan Metode Reduksi Data

One of the algorithm for aerial image stitching system is SURF (Speeded Up Robust Features). It is a robust algorithm which is invariant to image scale, rotation, blurring, illumination, and affine transformation. Although SURF has good performance, some of the detected keypoints are not always considered as necessary keypoints . As a result, these unnecessary keypoints are needed to be eliminated to decrease computation time.The proposed system uses SURF detector in the detection process. The data reduction method will eliminate couple of keypoints which have near distance each other. Next, the keypoints will be described by SURF descriptor.The description Results further matched using FLANN. The next step is the search pattern with RANSAC homography matrix and stitch the picture to accumulate keypoints using warpPerpective.Stitching system are tested with some variations, such as scale variations, rotation variations, and overlap variations on the image. Based on the result, the proposed Data Reduction method has optimum value of minimal radius from 40 pixels to 100 pixels. The stitching process is still working with up to 90% keypoint number reduction. Average computation time using data reduction method are 39,41% faster than without data reduction method.