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A new technique is presented for computing very useful propagation parameters like effective core area and effective index of refraction of mono-mode dispersion shifted and dispersion flattened fibers both in the presence and in the absence of Kerr nonlinearity. The technique involves application of accurate but simple expressions for modal fields developed by Chebyshev formalism. The study of the influence of Kerr nonlinearity on the aforementioned parameters, however, requires the application of the method of iteration. For the purpose of such investigation, in linear as well as nonlinear region, we take some typically used dispersion shifted and dispersion flattened fibers and we show that the results found by our simple formalism are in excellent agreement with those obtained by using complex finite element method. Further, the necessary evaluation by our simple method needs very less computations. Thus, our formalism generates ample opportunity for applications in many areas in the field of nonlinear optics.

Ultra-long span unrepeatered systems using distributed Raman amplification are cost-effective solutions for bridging moderate transmission distances. However, there are two major limiting factors: nonlinear Kerr effect-induced nonlinear signal distortion and optical signal-to-noise ratio degradation due to spontaneous Raman noise. In this report, we proposed a model of three-segment hybrid fiber effective core area structure and developed a model covering: (1) generalized mathematical formulations, (2) analysis of three-segment Raman amplified link, and (3) simulation model of data transmission. The proposed model showed an improvement of the Raman gain profile, a reduction of the negative impact of the nonlinear Kerr effect, and an enhancement of the optical signal-to-noise ratio. A numerical simulation of the transmission performance of the three-segment hybrid structure was compared to conventional single-segment single fiber core structure on 80 Gb/s differential quadrature phase-shift keying (DQPSK) modulated data signals over a propagation distance of 390 km. The required optical signal-to-noise ratio was reduced by 2.71 dB to achieve the target error rate without using forward error correction. The numerical model and simulation of various data rates up to 100 Gb/s consistently showed that an improvement in transmission performance could be achieved by using three-segment hybrid fiber effective core area structure.

A hybrid photonic crystal fiber (PCF) rectangular-cored wrapping example has been presented for utilization in liquid (petrochemical) detecting purposes. Enhancing relative sensitivity while minimizing confinement loss has been the aim of the THz frequency range of 1.2 – 3.4 THz examination. At 2.2 THz, the suggested sensor exhibits an RS of 91.76% for x-polarization and 91.11% RS for y-polarization. In addition, for x-polarization, the PCF has an EA of 4.00 × 10 −08 m 2 , CL of 3.50 × 10 −10 dB/m, spot size of 1.54 × 10 −04 μm, and a very small EML of 0.0127 cm −1 . For y-polarization, the effective area is 3.02 × 10 −08 m 2 , the CL is 1.94 × 10 −10 dB/m, the spot size is 1.547 × 10 −04 μm and a very small EML of 0.0252 cm −1 . To investigate the overall outcome, full three-dimensional (3D) simulations are performed using COMSOL Multiphysics 5.6 software. Since the device’s rectangular shape core yields comparable findings in each of the polarization of x and y modes. so, our team examined the x,y in each of polarization modes in this work for petrol. The proposed sensor structure is simply constructed using standard manufacturing procedures. The proposed fiber might be considered a key component of practical applications of petrol adulteration measures.

A unique hollow core PCF with a decagonal shape, produced by an optical waveform, is created and analytically evaluated. In this paper, on the basis of refractive indices (RI), we detected the most common cancer cells, especially cervical carcinoma, which emerged from HeLa. Additionally, the properties of the guiding of the designed waveguide have been examined. In terms of FEM, a computational tool Comsol Multiphysics 5.6 Software’s are utilized for analyse salient features of the proposed cancer cell sensor. Additionally, to construct the graph of every result, Paint and MATLAB 18a are also used. With regard to cancer cells and normal cells, this detector achieves a relative sensitivity of around 99.845% and 99.50% and CL is 6.24 × 10 − 11 dB/m and 2.66 × 10 − 12 dB/m at 3.2 THz. This biosensor offers an extremely reliable and precise method for fast detection of Cancer Cell. The innovative method enhances the capability to seance and identify certain diseases, resulting for rapid treatment and good outcomes for patient. The PCF sensor is unique due to its hollow core decagonal-core structure, which significantly enhances light-matter interaction in the terahertz range and enables accurate cervical cancer cell detection. This innovative method offers a non-invasive, label-free testing procedure with great depth resolution and selectivity, compared to traditional detection approaches.

Edge effects have been studied for decades because they are a key component to understanding how landscape structure influences habitat quality. However, making sense of the diverse patterns and extensive variability reported in the literature has been difficult because there has been no unifying conceptual framework to guide research. In this review, we identify four fundamental mechanisms that cause edge responses: ecological flows, access to spatially separated resources, resource mapping, and species interactions. We present a conceptual framework that identifies the pathways through which these four mechanisms can influence distributions, ultimately leading to new ecological communities near habitat edges. Next, we examine a predictive model of edge responses and show how it can explain much of the variation reported in the literature. Using this model, we show that, when observed, edge responses are largely predictable and consistent. When edge responses are variable for the same species at the same edge type, observed responses are rarely in opposite directions. We then show how remaining variability may be understood within our conceptual frameworks. Finally, we suggest that, despite all the research in this area, the development of tools to extrapolate edge responses to landscapes has been slow, restricting our ability to use this information for conservation and management.

The proposed dual-core photonic crystal fibers (DC-PCFs) structure has been simulated using FIMMWAVE and its performance has been evaluated using Finite element method (FEM). The result indicates an enhanced flattened dispersion profile for the wide range of wavelength which is the utmost requirement of optical communication system and links.

This study focuses on constructing a heritage corridor for traditional villages in the Taihu Lake region, aiming to promote the cultural heritage preservation and sustainable development of these villages through innovative pathway design. Based on the spatial distribution characteristics of traditional villages across five cities surrounding Taihu Lake (Suzhou, Wuxi, Changzhou, Huzhou, and Jiaxing) and the existing transportation network, this research integrates the Circuit Effective Conductance (CEC) theory with ArcGIS spatial analysis methods to optimize the pathways of the heritage corridor. The results show that the expected nearest neighbor distance of 307 traditional villages in the Taihu Lake region is 5245.61 m, with the actual nearest neighbor distance being 3385.60 m, a z-score of −11.85, and a nearest neighbor index of 0.645786, indicating that traditional villages in this region exhibit clustered distribution. Combined with kernel density results, a “dual-core–four zones–multiple scatter points” spatial structure of traditional villages in the Taihu Lake region is revealed, with Dongshan Island and Wujiang District serving as the primary and secondary cultural cores, respectively. By establishing a “dual-ring heritage corridor” spatial network, a stable pathway for village heritage preservation and cultural transmission has been formed, consisting of 137 heritage corridors. Meanwhile, the CEC model demonstrates high adaptability in generating circular heritage corridors, particularly in creating closed-loop structures around the lake, thereby enhancing the spatial connectivity of the corridors and facilitating the effective flow of cultural resources. Through the strategic design of outer and inner ring corridors, this study successfully links traditional villages in the Taihu Lake region and develops optimal travel routes. The study provides practical solutions for the protection, revitalization, and integration of cultural tourism in the region and offers a new perspective for constructing heritage corridors in lakefront geographies in China.

A photonic crystal fiber (O-PCF) with a novel structure consisting of five octagonal-shaped layers of circular air holes in the cladding region and two elliptical air holes in the core region is presented for application in different communication fields for terahertz (THz) wave propagation. The O-PCF fiber is investigated using perfectly matched layers by applying the finite element method. Based on the results of the simulations, the proposed O-PCF fiber shows a low effective material loss of 0.0162 cm −1 , a higher effective area of 5.88 × 10 –8 m 2 , a core power fraction of 80%, a scattering loss of 1.22 × 10 –10  dB/km, and a confinement loss of 3.33 × 10 –14  dB/m in the target region of 1 terahertz (THz). Due to its excellent characteristics, the proposed O-PCF fiber offers excellent transmission characteristic across a broad band of the terahertz region. Moreover, the suggested O-PCF fiber will be ideal for use in the terahertz (THz) region for different kinds of optical communication and biomedical applications.

Three-dimensional (3D) nanoscale crystal shaping has become essential for the precise design of advanced electronic and quantum devices based on electrically gated transport. In this context, III-V semiconductor-based nanowires with low electron effective mass and strong spin-orbit coupling are particularly investigated because of their exceptional quantum transport properties and the good electrostatic control they provide. Among the main challenges involved in the processing of these nanodevices are (i) the management of the gate stack which requires ex-situ passivation treatment to reduce the density of traps at the oxide/semiconductor interface, (ii) the ability to get good ohmic contacts for source and drain electrodes and (iii) the scalability and reliability of the process for the fabrication of complex architectures based on nanowire networks. In this paper, we show that selective area molecular beam epitaxy of in-plane InGaAs/InP core-shell nanowires with raised heavily doped source and drain contacts can address these different issues. Electrical characterization of the devices down to 4 K reveals the positive impact of the InP shell on the gate electrostatic control and effective electron mobility. Although comparable to the best reported values for In(Ga)As nanostructures grown on InP, this latter is severely reduced for sub-100 nm channel highlighting remaining issue to reach the ballistic regime.

Public health is at a watershed moment. The world’s health needs are changing, and complex problems require interdisciplinary approaches and systems-based solutions. Our longer lives and changing environments necessitate life-course and structural approaches to prevention. This argues strongly for public health graduate education that adequately prepares trainees to tackle emerging challenges and to lead now and in the future. Nearly a century of scholarship and scientific advances may offer a blueprint for training the next generation of public health leaders. We articulate a case for change; discuss some of the foundational principles that should guide public health education; and discuss what such a change might look like building on prior scholarship, on the examples set by other disciplines, and on our own experience.