Propagation Method Research Articles

Dynamic property evaluation of pipeline clamp based on analyzing the propagation characteristics of flexural wave in pipeline

The external clamp of hydraulic pipeline plays an important role in strengthening pipeline stiffness and improving vibration attenuation ability. In this study, wave propagation method is proposed to evaluate the translational and rotational stiffness and their loss factors of the clamp by analyzing the flexural wave propagation characteristics of pipeline. In order to validate the measured dynamic properties, experimental modal analysis was performed on the two-end elastically-supported pipeline. By modelling the pipeline with translational and rotational edge restraints, the analytical modal frequency parameters, wave numbers, and waveform coefficients were obtained. By comparing of the first-order flexural mode frequencies between experiment and analysis, the dynamic stiffness predicted by the wave propagation method was validated. The effects of the magnitude of torque, direction, clamping torque cycle, and clamp size on the complex dynamic properties of pipeline clamp were investigated. The proposed wave propagation method allows non-destructive continuous monitoring of a clamp stiffness, provides additional information about the vibration attenuation feature. It has advantages in clamp applications and is an effective methodology for measuring the dynamic properties of viscoelastic materials.

A sub-grid scale model for Burgers turbulence based on the artificial neural network method

The present study proposes a sub-grid scale model for the one-dimensional Burgers turbulence based on the neural network and deep learning method. The filtered data of the direct numerical simulation is used to establish the training data set, the validation data set, and the test data set. The artificial neural network (ANN) method and Back Propagation method are employed to train parameters in the ANN. The developed ANN is applied to construct the sub-grid scale model for the large eddy simulation of the Burgers turbulence in the one-dimensional space. The proposed model well predicts the time correlation and the space correlation of the Burgers turbulence.

Effect of Pre-treatments on Germination of Pterocarpus marsupium Roxb. for Developing Field Gene-Banks in Eastern India

Aims: Pterocarpus marsupium Roxb. is an important timber species with high medicinal properties belonging to the Fabaceae family. The species is severely threatened by anthropogenic and ecological pressures coupled with less natural regeneration. No results in vegetative propagation methods and very less germination is reported for the species under nursery conditions. This study investigates the germination potential of P. marsupium seeds under the prevailing climatic conditions of regions in eastern India. Place and Duration of Study: The study was carried out at the ICFRE - Institute of Forest Productivity (IFP), Lalgutwa, Ranchi, during the 24th to the 32nd Meteorological Standard Week (MSW) of 2022, spanning from June to August. Methodology: Seeds were collected from three CPTs selected from natural forests of Jharkhand, Bihar and West Bengal and the experiment was carried out following split plot design. Observations on several germination parameters and seed vigour indices were recorded until eight weeks after sowing and subjected to factor multivariate analysis of variance (MANOVA) in SPSS 25.0. Results: The experiment revealed that alternate wetting and drying of seeds significantly (P <. 001) outperformed all other treatments with a highest germination percentage of 60±1.196%. Accessions from Jharkhand and West Bengal exhibited significantly (P < .001) better vigour indices (1959.8, 1855.35 for SVI-I and 538.715, 527.742 for SVI-II, respectively) compared to the accession from Bihar (1796.49 and 532.618 for SVI-I and SVI-II). Although the study did not find any significant interaction between the treatments and accession, there was a statistically significant impact on the aggregate dependent variables (F (126,503.279) = 1.579, P <. 001; Wilks' Λ = .077). Conclusion: The results of this study report an economically feasible and rapid seed treatment method for establishing field gene banks of P. marsupium in eastern India to aid its ex-situ conservation practices.

A semi-analytical wavelet finite element method for wave propagation in rectangular rods

Prior knowledge of the dispersion curves and mode shapes of guided waves provides valuable information for wave mode selection and excitation in the field of non-destructive evaluation (NDE) and structural health monitoring (SHM). They are typically computed by the matrix methods, the finite element (FE) and semi-analytical finite element (SAFE) methods. However, the former is prone to numerical instability, and the latter two are limited by the refinement level of the FE mesh. In this paper, a semi-analytical wavelet finite element (SAWFE) method is presented to characterize wave propagation in rectangular rods. The piecewise polynomial interpolation functions of the SAFE method are replaced by two-dimensional scaling functions of the B-spline wavelet on the interval (BSWI). To demonstrate the accuracy of the proposed SAWFE technique, the propagation of guided waves in an aluminium plate is studied first. Then, the propagation of guided waves in rectangular rods of arbitrary aspect ratio is investigated. The results of this work clearly show that the SAWFE method presented here has higher accuracy and efficiency than the SAFE method.

Time Series Storage Method of Multi-Valued Attribute Data in Energy Big Data Center

Herein, the time series storage method of multi-valued attribute data, aimed at improving the efficiency of writing and querying data in “energy” big data centers is reported. Through rule construction and rule iteration of feature sequence, the time series features of multi-valued attribute data are extracted, and the “component attribute nearest neighbor propagation method” is used for clustering; the data are divided into cold, warm, and hot data. A storage engine with a solid state disk layer, mechanical hard disk layer, and memory layer has been designed, and the efficiency of data writing and query through migration operation is improved. The experimental results demonstrate that this method can effectively extract the time series features of multi-valued attribute data, and the Pre value of the clustering time series is higher than 0.93, which effectively improves the data writing and query efficiency of the energy big data center.

Chromatic correction for super multi-view 3D display based on diffraction theory.

The traditional analysis method for super multi-view 3D display based on geometric optics, which approximates the lenticular lenses as a series of pinhole structures, ignored the chromatic aberration. In this paper, the optimization method based on diffraction theory is proposed for super multi-view 3D display, where the wavefronts are evaluated accurately by the forward propagation method, and the chromatic aberration of the synthetic viewpoint image is reduced dramatically by the backward reconstruction optimization method (BROM). The optical experiment is performed to verify the feasibility of the method, which is consistent with numerical simulation results. It is proved that the proposed method simulates the physical propagation process of super multi-view 3D display and improves the reconstructed image quality. In the future, it can be used to achieve the super multi-view 3D light field technology with low crosstalk.

Multiple-pathways light modulation in Pleurosigma strigosum bi-raphid diatom.

Ordered, quasi-ordered, and even disordered nanostructures can be identified as constituent components of several protists, plants and animals, making possible an efficient manipulation of light for intra- and inter- species communication, camouflage, or for the enhancement of primary production. Diatoms are ubiquitous unicellular microalgae inhabiting all the aquatic environments on Earth. They developed, through tens of millions of years of evolution, ultrastructured silica cell walls, the frustules, able to handle optical radiation through multiple diffractive, refractive, and wave-guiding processes, possibly at the basis of their high photosynthetic efficiency. In this study, we employed a range of imaging, spectroscopic and numerical techniques (including transmission imaging, digital holography, photoluminescence spectroscopy, and numerical simulations based on wide-angle beam propagation method) to identify and describe different mechanisms by which Pleurosigma strigosum frustules can modulate optical radiation of different spectral content. Finally, we correlated the optical response of the frustule to the interaction with light in living, individual cells within their aquatic environment following various irradiation treatments. The obtained results demonstrate the favorable transmission of photosynthetic active radiation inside the cell compared to potentially detrimental ultraviolet radiation.

PENGEMBANGAN BIBIT PORANG DARI BEBERAPA SUMBER DENGAN BERBAGAI MEDIA TUMBUH MELALUI TEKNIK POTTING MIX PADA TANAH ENTISOL

Porang plants (Amorphophallus muelleri Blume) are herbaceous plants that are commonly found growing wild in forested areas, under bamboo clumps, along riverbanks, on mountain slopes, amidst dense and humid vegetation. Porang propagation from corms and cormels requires a considerable amount of time, around 7-9 months. Therefore, there is a need for the development of porang seedlings through easy vegetative propagation methods that can be implemented at the farmer level. This research utilized Entisol soil originating from Andalan Village, Bayan Subdistrict, North Lombok Regency. The research was conducted using an experimental method. The treatments were arranged using a Completely Randomized Design (CRD) involving 4 seed sources (porang cormels/bulbils, split corms, porang leaves, and porang stems) with 3 treatments, namely no treatment, biochar, liquid organic fertilizer, PGPR, and Trubus plant growth regulator. The analysis of variance results showed that the application of various growing media (biochar, liquid organic fertilizer, and PGPR) influenced changes in soil properties and the growth of porang seedlings. The growth of porang seedlings was influenced in the split corm and cormel techniques. Further tests indicated that the cormel technique, specifically in terms of plant height and stem diameter, was affected by the addition of organic materials compared to the absence of organic material application

Enhancing sustainable urban air transportation: Low-noise UAS flight planning using noise assessment simulator

Low-altitude flights of unmanned aircraft systems (UASs), such as drones, can cause substantial noise pollution in urban areas. This study aims to tackle the crucial issue of noise in UAS flight planning and analyze the feasibility of implementing low-noise urban flights at a micro level. We employ a virtual flight simulator to accurately model the UAS noise impact in realistic flights and optimize the flight path via a heuristic algorithm accordingly. The flight noise assessment incorporates a sound source modeling technique for practical UAS models and an efficient Gaussian beam tracing method for outdoor noise propagation in realistic environments. Case studies for flight simulations are conducted in a representative resident community and metropolitan area to evaluate the noise impact resulting from different flight paths. By comparing our approach with benchmark shortest-distance paths, we validate its effectiveness in significantly reducing en-route noise exposure, encompassing both instantaneous and continuous noise levels. This method holds great potential for contributing to the planning and management of urban air transport systems. It effectively mitigates noise impact, promoting quieter and more environmentally friendly UAS operations and sustainable urban transportation.

Geometric Algebra based 2D-DOA Estimation for Non-circular Signals with an Electromagnetic Vector Array

This paper presents two novel methods based on geometric algebra (GA) to estimate two-dimensional (2D) direction-of-arrival (DOA) of non-circular (NC) signals for uniform rectangular array (URA). Traditional methods treat the received NC signals as a long vector which will inevitably lose orthogonality inside each electromagnetic vector sensor (EMVS) and thus miss some information of second-order statistical properties. Furthermore, the computational complexity will also increase. By contrast, the GA-based estimating signal parameter via rotational invariance techniques (ESPRIT) and propagation method (PM) algorithms are proposed to estimation DOA of NC signals. Taking advantage of GA, the relationship among multidimensional signals can be maintained. First, the six components of the EMVS are represented as a multivector in GA space. Then, we construct the GA-based extended covariance matrix to utilize the signal information more completely. The DOA parameters can be estimated through the ESPRIT and PM principle. The proposed GA-based estimation of signal parameter via rotational invariance techniques for NC signals processing (GANC-ESPRIT) can estimate DOA with high estimation accuracy. The proposed GA-based propagation method for NC signals estimation (GANC-PM) uses linear transformation to calculate angle parameters. Our model has much lower memory requirements and less computational burden compared with long vector models. Simulation results demonstrate the robustness and superiority of the proposed GANC-ESPRIT algorithm in terms of angular resolution. Complexity analysis shows that the proposed GANC-PM algorithm performances better with less computations.

In vitro Callus Regeneration and Chlorophyll Content Estimation in Glycine max (L.) variety from Uttarakhand, India

Soybean (Glycine max) is considered one of the most substantial produced crops across the globe because of its high nutritional value. It is a great alternative for lactose-intolerant patients and vegans to fulfil their daily protein requirements. Soybean has various varieties depending upon the colour of their seed coat. In the past few years, the consumption of Soybean has increased which demands higher production, better yield, and better seed quality. Conventional propagation methods fail to fulfil such demands. The alternate method of plant tissue culture ensures rapid mass propagation, better yield, and quality of the plants. However, the technique is often beset with challenges of low-field performance of tissue culture-raised plants due to defective chloroplast machinery. The present study investigates the effect of various plant growth regulators (PGRs) on in vitro propagation of soybean cultivars from different regions of Uttarakhand, India, and their effect on chlorophyll content in the regenerated tissues.

Near-infrared Y-branch polymer splitters realized with compact MMI structures for efficient power splitting

Optical splitters are promising photonic devices for next-generation photonic integrated circuits, which enable signal distribution and routing between the different components, facilitating complex optical functionalities on a single chip. This research introduces what we believe is a novel numerical technique for enhancing optical network efficiency by incorporating a taper-based step-index (SI) Y-branch multimode interference (MMI) splitter with organic-inorganic hybrid polymer materials. The proposed device comprises a core width of 5 µm for the input and output waveguides to satisfy the single-mode conditions. We designed and optimized the MMI splitter using the beam propagation method (BPM). The splitter demonstrates the power splitting property with an efficiency of 86%. The excess losses for the MMI splitter are 0.52 dB and 0.50 dB for TE and TM modes, respectively, at 1.55 µm. The polarization dependence loss (PDL) and propagation loss (PL) are 0.015 dB and 0.00019 dB/µm, respectively.

An adaptive finite element method for coupled fretting wear and fatigue crack propagation simulation

Fretting wear and fatigue crack propagation often occur at the same time in the service of mechanically connected structures. In order to analyze the effect of fretting wear on the process of fatigue crack propagation, a finite element simulation method for fatigue crack propagation considering fretting wear is proposed. In this method, the Archard model is used to predict the wear process, and the conventional Paris equation is modified based on the wear rate. In order to improve the accuracy of crack propagation prediction, a crack-tip super singular element (CSSE) is used to calculate the singular stress field and fracture control parameters of the crack tip. An adaptive meshing technique that automatically adjusts the mesh density according to the simulation process is designed to ensure the computational efficiency of the algorithm and the accuracy of the numerical results. The smoothing technique used in wear simulation can alleviate the influence of contact stress fluctuation on wear profile prediction. The usage of the new simulation method is introduced through benchmark examples. It is proved that the numerical results of crack propagation obtained by the adaptive finite element method (FEM) have high precision, good convergence and high computational efficiency. It is found that wear reduces the crack growth rate compared with the simulation results without considering wear. This method has a promising application in the coupling analysis of fretting wear and fatigue crack propagation of mechanically connected structures.

The effect of sodium nitroprusside on the vegetative development of Aronia melanocarpa [Michx.] Elliot under in vitro conditions

Aronia is a berry fruit that has a significant amount of antioxidants. Both sexual and vegetative methods of propagation are available for aronia. Genetic diversity is present in the process of seed propagation. Therefore, clonal propagation techniques such as cuttings, basal shoots, and tissue culture are preferred. Plant tissue culture is a process that offers a high multiplication rate and the ability to produce clean plant material. This study aimed to stimulate the growth of plantlets by introducing several growth-promoting agents into the culture media. Specifically, the effects of a nitric oxide donor SNP (sodium nitroprusside) on the vegetative development of the plants were examined under in vitro conditions. Four distinct concentrations of SNP (0, 100, 200, and 300 µM) were administered to promote vegetative development. The survival rate (%), rooting rate (%), root number (per plantlet), root length (cm), leaf number (per plantlet), shoot length (cm), plant fresh weight (g), and plant dry weight (g) of the plantlets were estimated on the 60th day of growth in the nutrient medium under in vitro conditions. The survival rate was 100% for the applications of SNP at concentrations of 100 µM and 200 µM. The 0 µM treatment had the highest root number, the 100 µM treatment had the longest root, and the 200 µM treatment had the highest values for shoot length. The 0 µM treatment provided the highest values for plant fresh weight, while the 0 and 100 µM applications resulted in the highest plant dry weight values. The study suggested that an increased concentration of SNP causes a toxic effect.

Hourglass-Shaped Fiber-Optic Mach-Zehnder interferometer for pressure sensing

A fiber-optic pressure sensor based on an hourglass-shaped structure (HSS) is proposed and demonstrated. A Mach-Zehnder interferometer (MZI) is constructed in the inside cavity of the HSS. The HSS consists of a silica frame and two photoresist diaphragms covered on side holes of the frame. Pressure response of the MZI is analyzed by theoretical calculation, the mechanical deformation of the HSS is simulated by using the finite element method, and the spectral characteristics of the sensor are simulated by using the finite-difference beam propagation method. Experimental results indicate that the pressure sensitivity of the sensor with a size of 0.2 × 0.2 × 0.5 mm3 reaches –1.27 nm/kPa with a linear response range of 0–35 kPa. In addition, repeatability, time stability, the cross-responses to ambient refractive index (RI) and temperature, and response time of the sensor are evaluated experimentally. With advantages of high sensitivity, compact size, and insensitivity to ambient RI, the proposed sensor shows promising potential in optofluidic and biomedical sensing fields.

Synthetic Seed Production and Slow Growth Storage of In Vitro Cultured Plants of Iris pallida Lam.

Iris pallida Lam. is traditionally cultivated in Italy to sell its rhizomes to perfume-producing industries and is particularly sought-after because of its high content of irones, ketone compounds responsible for the violet smell of the orris essence. One of the critical aspects of its cultivation is the propagation method, performed by subdividing and replanting sections of the rhizome, which leads to the sacrifice of salable material. A solution is provided via in vitro propagation using the somatic embryogenesis technique, an effective method that allows the production of plants without the use of the rhizome. To facilitate the scale up of the activities of micropropagation companies, the method of slow growth storage (SGS) for orris plantlets and a somatic embryo encapsulation technique were developed for the first time. Orris plantlets were placed at 4 °C in the dark for 30, 60, 90 and 120 days and monitored 7 and 30 days after treatment. Synthetic seeds were obtained by encapsulating somatic orris embryos in sodium alginate beads, which were stored for 14 and 28 days at 4 °C and 24 °C. The results showed that it is possible to cold-preserve orris plantlets for up to 90 days without significant damages and that orris synthetic seeds can be produced and stored for a short-to-mid-term period. These conservation techniques can be useful for germplasm conservation and can also be integrated in the micropropagation cycle of orris, helping to solve issues related to the traditional propagation method.

From Seed to Succulence: Mastering Dragon Fruit Propagation Techniques

From Seed to Succulence: Mastering Dragon Fruit Propagation Techniques delves into the intricacies of propagating dragon fruit, a fascinating tropical fruit known for its exotic appearance and nutritional benefits. This article explores various propagation methods, including seed germination, stem cuttings, and grafting, shedding light on the challenges and rewards associated with each technique. By elucidating the principles of dragon fruit propagation and offering practical tips for success, this article equips growers with the knowledge and skills to cultivate thriving dragon fruit plants from seed to succulence. Whether you’re a novice enthusiast or an experienced horticulturist, this comprehensive guide serves as an invaluable resource for mastering the art of dragon fruit propagation and reaping the rewards of homegrown delicacies.

Evolution of drought characteristics and propagation from meteorological to agricultural drought under the influences of climate change and human activities.

Understanding the propagation of agricultural droughts (AD) is important to comprehensively assess drought events and develop early warning systems. The present study aims to assess the impacts of climate change and human activities on drought characteristics and propagation from meteorological drought (MD) to AD in the Yellow River Basin (YRB) over the 1950-2021 period using the Standardized Precipitation Evapotranspiration Index (SPEI) and Standardized Soil Moisture Index (SSMI). In total, the YRB was classified into three groups of catchments for spring wheat and four groups of catchments for winter wheat based on different human influence degrees (HId). In addition, the entire study period was divided into periods with natural (NP), low (LP), and high (HP) impacts of human activities, corresponding to 1950-1971, 1972-1995, and 1996-2021, respectively. The results demonstrated the significance and credibility of the application of the natural and human-impacted catchment comparison method for drought characteristics and propagation from meteorological to agricultural drought in the YRB. Winter wheat showed a more pronounced drying trend than spring wheat under both MD and AD. The results showed meteorological drought intensity (MDI) and agricultural drought intensity (ADI) intensified for spring and winter wheat in NP, with correspondingly a short propagation time, followed by those in the LP and HP in catchments minimally impacted by human activities. On the other hand, increases in the MDI and ADI, as well as in their times, for both spring and winter wheat were observed from the LP to the HP in all catchments. The MDI, ADI, and their propagation times for winter wheat generally showed greater fluctuations than those for spring wheat. Human activities increasingly prolonged the drought propagation time. In contrast, climate change insignificantly shortened the drought propagation time.

Efficient light propagation algorithm using quantum computers

Quantum algorithms can potentially overcome the boundary of computationally hard problems. One of the cornerstones in modern optics is the beam propagation algorithm, facilitating the calculation of how waves with a particular dispersion relation propagate in time and space. This algorithm solves the wave propagation equation by Fourier transformation, multiplication with a transfer function, and subsequent back transformation. This transfer function is determined from the respective dispersion relation, which can often be expanded as a polynomial. In the case of paraxial wave propagation in free space or picosecond pulse propagation, this expansion can be truncated after the quadratic term. The classical solution to the wave propagation requires O(NlogN) computation steps, where N is the number of points into which the wave function is discretized. Here, we show that the propagation can be performed as a quantum algorithm with OlogN2 single-controlled phase gates, indicating exponentially reduced computational complexity. We herein demonstrate this quantum beam propagation method (QBPM) and perform such propagation in both one- and two-dimensional systems for the double-slit experiment and Gaussian beam propagation. We highlight the importance of the selection of suitable observables to retain the quantum advantage in the face of the statistical nature of the quantum measurement process, which leads to sampling errors that do not exist in classical solutions.

An automated measurement method for the fatigue crack propagation based on decorrelated digital image correlation

Measurements of fatigue crack propagation are crucial for fatigue tests. Nowadays, fatigue tests still necessitate experimenters to manually observe and document the propagation of fatigue cracks, a process that proves to be extremely time-consuming and labor-intensive. This study introduces a novel approach to fatigue crack measurement by employing the decorrelated digital image correlation (DIC) technique, which stands in contrast to the conventional DIC method. The proposed method utilizes decorrelation field to extract crack propagation path. The proposed method enables the automated measurement of fatigue crack parameters such as width, length, and morphology. Both numerical simulations and physical model experiments were conducted to validate the effectiveness of the proposed method. The numerical experiments demonstrate that the method achieves sub-pixel level accuracy in measuring crack width, length, and morphology. The results from physical experiment further affirm the feasibility of the method for practical application.