Zeitschrift für Naturforschung A最新文献

Computation Legendre moments using image analysis technique 利用图像分析技术计算 Legendre 矩

Zeitschrift für Naturforschung A Pub Date : 2024-09-03 DOI: 10.1515/zna-2024-0116

Karamcheti Mallika, K. Vijaya Lakshmi, K. Lakshmi Sarada, S. Sreehari Sastry

{"title":"Computation Legendre moments using image analysis technique","authors":"Karamcheti Mallika, K. Vijaya Lakshmi, K. Lakshmi Sarada, S. Sreehari Sastry","doi":"10.1515/zna-2024-0116","DOIUrl":"https://doi.org/10.1515/zna-2024-0116","url":null,"abstract":"In this paper, phase transition temperatures of nematic liquid crystals: 4-n alkoxy benzoic acid (nOBA, where n = 4 and 6) are determined from the Legendre moments of liquid crystal textures. Here, the image analysis technique in conjunction with polarizing optical microscope is used to compute the Legendre moments from the textures of liquid crystals. As a function of temperature, Liquid crystal textures are recorded from the arthroscopic mode of optical microscope. Changes in textural features of the sample with respect to temperature bring the variations in intensity values of liquid crystal textures. The brightness image that is generated from the liquid crystal textural patterns separates the information about fluctuations in intensity. In this approach, Legendre moments are computed from the brightness images of the liquid crystal textures and are plotted as a function of temperature. Significant variations in the brightness Legendre moment curve provide insight into the liquid crystal transition temperatures. Results obtained from the present methodology are compared with gray color textures data and the experimental technique of differential scanning calorimetry and are in good agreement with each other. This method is an objective and quantitative technique whereas POM method is qualitative and subjective.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Free vibration analyses of 3D printed plates with different geometric fillings: experimental testing and numerical simulations 具有不同几何填充物的 3D 打印板的自由振动分析：实验测试和数值模拟

Zeitschrift für Naturforschung A Pub Date : 2024-09-03 DOI: 10.1515/zna-2024-0062

Ahmet Yildiz, Emre İbram, Onur Erol, Hande Güler Özgül

引用次数: 0

Research on adaptive optics technology based on phase contrast Gerchberg Saxton algorithm 基于相位对比 Gerchberg Saxton 算法的自适应光学技术研究

Zeitschrift für Naturforschung A Pub Date : 2024-09-02 DOI: 10.1515/zna-2024-0058

Rui Wang, Xizheng Ke, Jingyuan Lang, JiaLi Wu

{"title":"Research on adaptive optics technology based on phase contrast Gerchberg Saxton algorithm","authors":"Rui Wang, Xizheng Ke, Jingyuan Lang, JiaLi Wu","doi":"10.1515/zna-2024-0058","DOIUrl":"https://doi.org/10.1515/zna-2024-0058","url":null,"abstract":"In wireless optical communication, the optical signal passes through the atmospheric turbulence, resulting in the simultaneous distortion of the amplitude and phase of the optical signal at the receiving end. This article applies the idea of phase contrast method to simultaneously compensate the amplitude and phase of the optical signal at the receiving end, derives the mapping relationship between the compensated phase and light intensity, and obtains the required compensated phase for full-field compensation. Numerical calculations show that when the difference between zero-frequency phase compensation and nonzero-frequency phase compensation is ±π, the maximum light intensity compensation is obtained. Based on the Gerchberg Saxton algorithm, a new method is proposed to invert the compensated phase with the maximum light intensity after full-field compensation and perform full-field correction through the adaptive optical system. The numerical calculation and experiment show that the phase contrast Gerchberg Saxton algorithm can effectively compensate the distorted optical signals under different turbulence, and thus the received signals of optical wireless communication can be corrected in full field.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Computerized simulation of 2-dimensional phase contrast images using spiral phase plates in neutron interferometry 在中子干涉测量中使用螺旋相位板对二维相衬图像进行计算机模拟

Zeitschrift für Naturforschung A Pub Date : 2024-08-17 DOI: 10.1515/zna-2024-0142

Wolfgang Treimer, Frank Haußer, Martin Suda

{"title":"Computerized simulation of 2-dimensional phase contrast images using spiral phase plates in neutron interferometry","authors":"Wolfgang Treimer, Frank Haußer, Martin Suda","doi":"10.1515/zna-2024-0142","DOIUrl":"https://doi.org/10.1515/zna-2024-0142","url":null,"abstract":"We present calculations of interferograms (interference patterns) of one or multiple spiral phase plates that would be observed with a perfect crystal neutron interferometer of Mach–Zehnder type. A spiral phase plate (SPP) in one of the two coherent beam paths produces a twist in the phase front and thus a vortex beam with intrinsic angular momentum, which in the case of neutrons should be observed as a characteristic interference pattern that appears complementary to each other in both detectors behind the interferometer. Adding additional SPPs in one beam path of the interferometer yield interference patterns similar to that of a single SPP but only due to the cumulative step height. All simulated interferograms have been calculated on the basis of dynamical neutron diffraction without any assumption of a neutron orbital angular momentum and show very convincing agreement with experimental results from the literature, see e.g. (C. W. Clark, R. Barankov, M. G. Huber, M. Arif, D. G. Cory, and D. A. Pushin, “Controlling neutron orbital angular momentum,” Nature, vol. 525, pp. 504–506, 2015). In particular, this clarifies, that the cited experiments do not give evidence of the quantization of interactions caused by a twist of the phase front of a neutron wave in the interferometer and thus no evidence for the effect of a neutron orbital angular momentum.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Invariant analysis of the multidimensional Martinez Alonso–Shabat equation 多维马丁内斯-阿隆索-沙巴特方程的不变分析

Zeitschrift für Naturforschung A Pub Date : 2024-08-16 DOI: 10.1515/zna-2024-0115

Naseem Abbas, Akhtar Hussain, Muhammad Waseem Akram, Shah Muhammad, Mohammad Shuaib

引用次数: 0

Dynamical investigation of the perturbed Chen–Lee–Liu model with conformable fractional derivative 具有保形分数导数的扰动陈-李-刘模型的动力学研究

Zeitschrift für Naturforschung A Pub Date : 2024-08-16 DOI: 10.1515/zna-2024-0112

Nilkanta Das, S. Saha Ray

{"title":"Dynamical investigation of the perturbed Chen–Lee–Liu model with conformable fractional derivative","authors":"Nilkanta Das, S. Saha Ray","doi":"10.1515/zna-2024-0112","DOIUrl":"https://doi.org/10.1515/zna-2024-0112","url":null,"abstract":"This study focuses on the investigation of the perturbed Chen–Lee–Liu model with conformable fractional derivative by the implementation of the generalized projective Riccati equations technique. The proposed method uses symbolic computations to provide a dynamic and powerful mathematical tool for addressing the governing model and yielding significant results. Numerous analytical solutions of the governing model, including bell-shaped soliton solutions, anti-kink soliton solutions, periodic solitary wave solutions and other solutions, have been constructed effectively utilizing this effective technique. The findings acquired from the governing model utilizing the suggested technique demonstrate that all results are novel and presented for the first time in this study. Solitons are of immense significance in the domain of nonlinear optics due to their inherent ability to preserve their shape and velocity during propagation. The study of the propagation and the dynamical behaviour of the derived results have been explored by representing them graphically through 3D, density, and contour plots with different selections of arbitrary parameter values. The solitons acquired from the proposed model can provide significant advantages in the field of fiber-optic transmission technology. The obtained results demonstrate that the suggested approach is extremely promising, straightforward, and efficient. Furthermore, this approach may be effectively used in numerous emerging nonlinear models found in the fields of applied sciences and engineering.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of dilating forcing amplitudes on a peristaltically driven non-Newtonian fluid in an elastic tube: application to swallowing disorders 扩张强迫振幅对弹性管中蠕动非牛顿流体的影响：在吞咽障碍中的应用

Zeitschrift für Naturforschung A Pub Date : 2024-08-05 DOI: 10.1515/zna-2024-0063

Sanjay K. Pandey, Anupam K. Pandey

{"title":"Impact of dilating forcing amplitudes on a peristaltically driven non-Newtonian fluid in an elastic tube: application to swallowing disorders","authors":"Sanjay K. Pandey, Anupam K. Pandey","doi":"10.1515/zna-2024-0063","DOIUrl":"https://doi.org/10.1515/zna-2024-0063","url":null,"abstract":"We investigate the flow dynamics within an elastic tube transporting a power-law fluid, where the tube is subject to a specified external forcing in the form of a progressive traveling wave. The oesophagus is cylindrical in shape and exhibits linear elastic properties. The flow is creeping, and the long wavelength and low Reynolds number approximations are employed for a solution. The relationship between the pressure distribution within the oesophagus and the radial variation of the tube characterizes the behavior of the tube. Findings reveal that the elasticity and the variations in the applied dilating forcing amplitude substantially impact pressure resulting from sinusoidal wave forcing. Notably, even a nominal increase in the inward radial force amplitude for dilatant fluid results in significant pressure changes compared with Newtonian fluid. We also observe a notable distinction between time-averaged volume flow rate and velocity in pseudo-plastic and dilatant forms. Our study also identifies that the radial velocity experiences either attenuation or enhancement due to the fluid’s shear thickening and thinning characteristics. Moreover, our research uncovers a novel dimension by highlighting that in shifting from pseudo-plasticity to dilatancy, the fluid requires higher pressure to propel the bolus toward the hiatus. This observation has important implications, suggesting that feeding a more dilatant fluid to patients with pre-diagnosed swallowing disorders, such as sliding hiatus hernia, is not advisable, fearing increased pressure.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Laminar flow with temperature-dependent fluid properties between two stretching rectangular surfaces 两个拉伸矩形表面之间具有随温度变化的流体特性的层流

Zeitschrift für Naturforschung A Pub Date : 2024-07-27 DOI: 10.1515/zna-2024-0101

Nicolas Mam Bakalack, Valjacques Nyemb Nsoga, Gérémino Ella Eny, Martin N. Azese, Jacques Hona

{"title":"Laminar flow with temperature-dependent fluid properties between two stretching rectangular surfaces","authors":"Nicolas Mam Bakalack, Valjacques Nyemb Nsoga, Gérémino Ella Eny, Martin N. Azese, Jacques Hona","doi":"10.1515/zna-2024-0101","DOIUrl":"https://doi.org/10.1515/zna-2024-0101","url":null,"abstract":"The Navier–Stokes equations and the energy equation are used to investigate a fluid flow between two stretching rectangular surfaces subjected to a temperature difference that affects the dynamic viscosity and thermal conductivity of the fluid. The wall stretching process enhances the momentum boundary layer thickness which slows the axial motion of the fluid away from the flow boundaries. When the stretching parameter γ is equal to 1, that is the case corresponding to symmetric stretching, the minimum of the axial velocity is located at the midplane of the channel y = 0.5 if the viscosity variational parameter α equals 0. This minimum moves towards the region 0.5 < y < 1 for α > 0, but migrates towards the region 0 < y < 0.5 for α < 0. Moreover, in the case of symmetric stretching corresponding to γ = 1, the growth in Reynolds number Re tends to increase the axial velocity around the middle of the channel for α ≥ 0 in the attempt to counteract the effects of enhancing the momentum boundary layer thickness leading to the flattening of axial velocity profiles for Re ≥ 100. While the conductivity variational parameter β does not influence enough the fluid dynamics and heat transfer, the Reynolds number Re and the Péclet number Pé can increase or decrease the temperature distribution inside the channel depending on the sign of the parameter α. Practical applications related to the present study include lubrification, food manufacturing, paint industries, extrusion processes in plastic and metal industries.","PeriodicalId":23871,"journal":{"name":"Zeitschrift für Naturforschung A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wronskian solution, Bäcklund transformation and Painlevé analysis to a (2 + 1)-dimensional Konopelchenko–Dubrovsky equation (2 + 1)维 Konopelchenko-Dubrovsky 方程的 Wronskian 解、Bäcklund 变换和 Painlevé 分析

Zeitschrift für Naturforschung A Pub Date : 2024-07-18 DOI: 10.1515/zna-2024-0016

Di Gao, Wen-Xiu Ma, Xing Lü

引用次数: 0

Neutron dynamics in ultra-strong electromagnetic fields: an example model 超强电磁场中的中子动力学：一个示例模型

Zeitschrift für Naturforschung A Pub Date : 2024-07-16 DOI: 10.1515/zna-2024-0070

Stanley A. Bruce

引用次数: 0