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Keywords = response interval envelopes

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17 pages, 3781 KiB  
Article
Research on Non-Random Vibration Analysis of Concrete Pump Truck Boom Based on Dynamic Excitation
by Weixin Zhou, Wubin Xu, Bing Li, Yuanbin Xiao, Xianyu Liu, Hanwen Zhang and Bo Xu
Appl. Sci. 2025, 15(4), 1770; https://doi.org/10.3390/app15041770 - 10 Feb 2025
Viewed by 671
Abstract
When pouring concrete overhead, a pump truck boom’s vibration has a big effect on how accurately the concrete is poured. This is especially true during fixed-point pouring, where the boom’s vibration is likely to cause the pouring position to deviate, which lowers the [...] Read more.
When pouring concrete overhead, a pump truck boom’s vibration has a big effect on how accurately the concrete is poured. This is especially true during fixed-point pouring, where the boom’s vibration is likely to cause the pouring position to deviate, which lowers the quality of the construction. It is difficult to forecast the dynamic reaction of the pump truck boom in a construction setting because of the constantly shifting external factors (wind speed, pipeline stress during pumping, etc.), which makes it difficult to guarantee casting accuracy. This study suggests a non-random vibration analysis technique for pump truck booms based on the interval process theory in order to address this issue. A dynamic excitation analysis method based on rigid–discrete coupling is proposed, taking into account the response influence of the material characteristics in the transportation process. The pumping process of concrete materials in the conveying pipeline is simulated using discrete element simulation technology to determine the system’s stress conditions under pumping conditions. The dynamic response characteristics of the pump truck boom under operating conditions are revealed by using non-random vibration analysis with the mathematical model that has been created based on the particular specifications of the pump truck boom. This study employs the Newmark-β technique for numerical computation to solve the dynamic equations and characterize the displacement response envelope under uncertain system parameter settings. The experimental findings demonstrate that the suggested approach may accurately capture the upper and lower bounds of the boom dynamic response, offering a trustworthy way to assess the dynamic behavior while pumping. The technique can reliably predict the dynamic displacement boundary and control the casting position deviation within a predefined range by accurately predicting the dynamic displacement range of the pump truck’s boom end and efficiently constructing the displacement envelope under uncertain dynamic excitation. For numerical computation, use the Newmark-β algorithm. This outcome confirms the substantial enhancement of the proposed method regarding pouring precision in construction settings, offering a novel solution and technical guidance for vibration control in engineering projects. Full article
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27 pages, 9621 KiB  
Article
Estimating and Modeling Pinus contorta Transpiration in a Montane Meadow Using Sap-Flow Measurements
by Simon Marks, Christopher Surfleet and Bwalya Malama
Forests 2024, 15(10), 1786; https://doi.org/10.3390/f15101786 - 11 Oct 2024
Cited by 2 | Viewed by 988
Abstract
This study quantifies the transpiration of encroached lodgepole pine (Pinus contorta var. murryana (Grev. & Balf.) Engelm.) in a montane meadow using pre-restoration sap-flow measurements. Lodgepole pine transpiration and its response to environmental variables were examined in Rock Creek Meadow (RCM), Southern [...] Read more.
This study quantifies the transpiration of encroached lodgepole pine (Pinus contorta var. murryana (Grev. & Balf.) Engelm.) in a montane meadow using pre-restoration sap-flow measurements. Lodgepole pine transpiration and its response to environmental variables were examined in Rock Creek Meadow (RCM), Southern Cascade Range, CA, USA. Sap-flow data from lodgepole pines were scaled to the meadow using tree survey data and then validated with MODIS evapotranspiration estimates for the 2019 and 2020 growing seasons. A modified Jarvis–Stewart model calibrated to 2020 sap-flow data analyzed lodgepole pine transpiration’s correlation with solar radiation, air temperature, vapor pressure deficit, and soil volumetric water content. Model validation utilized 2021 growing season sap-flow data. Calibration and validation employed a Markov Chain Monte Carlo (MCMC) approach through the DREAM(ZS) algorithm with a generalized likelihood (GL) function, enabling parameter and total uncertainty assessment. The model’s scaling was compared with simple scaling estimates. Average lodgepole pine transpiration at RCM ranged between 220.6 ± 25.3 and 393.4 ± 45.7 mm for the campaign (mid-July 2019 to mid-August 2020) and 100.2 ± 11.5 to 178.8 ± 20.7 mm for the 2020 partial growing season (April to mid-August), akin to MODIS ET. The model aligned well with observed normalized sap-velocity during the 2020 growing season (RMSE = 0.087). However, sap-velocity, on average, was underpredicted by the model (PBIAS = −6.579%). Model validation mirrored calibration in performance metrics (RMSE = 0.1233; PBIAS = −2.873%). The 95% total predictive uncertainty confidence intervals generated by GL-DREAM(ZS) enveloped close to the theoretically expected 95% of total observations for the calibration (94.5%) and validation (81.8%) periods. The performance of the GL-DREAM(ZS) approach and uncertainty assessment in this study shows promise for future MJS model applications, and the model-derived 2020 transpiration estimates highlight the MJS model utility for scaling sap-flow measurements from individual trees to stands of trees. Full article
(This article belongs to the Section Forest Ecophysiology and Biology)
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19 pages, 4409 KiB  
Article
Sub-Nanosecond Single Mode-Locking Pulse Generation in an Idler-Resonant Intracavity KTA Optical Parametric Oscillator Driven by a Dual-Loss-Modulated Q-Switched and Mode-Locked Laser with an Acousto-Optic Modulator and MoWS2
by Chao Han, Hongwei Chu, Tianli Feng, Shengzhi Zhao, Dechun Li, Han Zhang, Jia Zhao and Weiping Huang
Nanomaterials 2024, 14(18), 1491; https://doi.org/10.3390/nano14181491 - 13 Sep 2024
Viewed by 1103
Abstract
The synthesis of 2D MoWS2 nanosheets involved the liquid-phase exfoliation technique was explored in this paper. The nonlinear optical response of MoWS2 was characterized in the 1 µm wavelength range, and its suitability as a saturable absorber (SA) was confirmed. Experimental [...] Read more.
The synthesis of 2D MoWS2 nanosheets involved the liquid-phase exfoliation technique was explored in this paper. The nonlinear optical response of MoWS2 was characterized in the 1 µm wavelength range, and its suitability as a saturable absorber (SA) was confirmed. Experimental demonstrations were conducted by using MoWS2 as an SA in an idler-resonant intracavity KTA optical parametric oscillator (OPO) driven by a dual-loss-modulated Q-switched and mode-locked (QML) YVO4/Nd:YVO4 laser with an acousto-optic modulator (AOM). By appropriately tuning the pump power and the AOM repetition rate, the Q-switched envelope pulse widths for the signal and idler waves could be significantly reduced to be shorter than the cavity round-trip transit time, i.e., the interval between two neighboring mode-locking pulses. Consequently, this enabled the generation of sub-nanosecond single mode-locking pulses with a low repetition rate, high pulse energy, and remarkable stability. With a repetition rate of 1 kHz and maximal pulse energies of 318 µJ and 169 µJ, respectively, sub-nanosecond single mode-locking pulses of the signal and idler waves were generated. The theoretical model was established using coupled rate equations with a Gaussian spatial distribution approximation. The numerical simulation results for generating sub-nanosecond single mode-locking pulses for the signal and idler waves within their respective Q-switched envelopes aligned fundamentally with the experimental results, proving that MoWS2 can be a potential nanomaterial for further optoelectronic applications. Full article
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12 pages, 2404 KiB  
Article
Early Phase of Specific Cellular Immune Status Associates with HCV Infection Outcomes in Marmosets
by Bochao Liu, Enhui Zhang, Xiaorui Ma, Shengxue Luo, Chong Wang, Ling Zhang, Wenjing Wang, Yongshui Fu, Jean-Pierre Allain, Chengyao Li and Tingting Li
Viruses 2023, 15(5), 1082; https://doi.org/10.3390/v15051082 - 28 Apr 2023
Cited by 1 | Viewed by 1732
Abstract
The major mechanism for determination of HCV infection outcomes has not been fully described, particularly in the early phase of the “window-period” of infection. Based on two groups of marmosets infected with HCV-CE1E2p7/GBV-B chimeric virus (HCV chimera) or GBV-B, the immune mechanism correlating [...] Read more.
The major mechanism for determination of HCV infection outcomes has not been fully described, particularly in the early phase of the “window-period” of infection. Based on two groups of marmosets infected with HCV-CE1E2p7/GBV-B chimeric virus (HCV chimera) or GBV-B, the immune mechanism correlating with the different outcomes of virus infections was explored in this study. HCV chimera containing the entire HCV core and envelope proteins (CE1E2p7) and GBV-B RNA were intrahepatically injected into four marmosets in each group, respectively. Blood samples were taken from individual animals in an interval of 2 weeks. Viral load and specific T cell responses were detected in two groups of HCV chimera- and GBV-B-infected marmosets. HCV chimera-infected marmosets appeared to have a virally persistent infection over 6 months post inoculation of the virus. Of these, the specific IFN-γ-secretion T cell response slowly developed over 13 to 19 weeks and was maintained at a relatively low level with 40–70 SFC/106 PBMCs, while the specific Treg cell response was rapidly activated over 3 weeks and was maintained at a high level around 5% among lymphocytes. In contrast, GBV-B-infected marmosets presented spontaneous viral clearance within 6 months; the specific IFN-γ-secretion T cell response was quickly established over 5 to 7 weeks and was maintained at a high level with 50–130 SFC/106 PBMCs, while the specific Treg cell response was inactivated and maintained at a baseline below 3% among lymphocytes. In conclusion, the HCV structural proteins inducing immune suppression in the early phase of HCV infection contributed to the viral persistence, of which the activation of Treg cells might play an important role in the inhibition of an effective T cell antiviral response. Full article
(This article belongs to the Section Human Virology and Viral Diseases)
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18 pages, 4608 KiB  
Article
Preliminary Analyses of the Hydro-Meteorological Characteristics of Hurricane Fiona in Puerto Rico
by Carlos E. Ramos Scharrón, José Javier Hernández Ayala, Eugenio Y. Arima and Francis Russell
Hydrology 2023, 10(2), 40; https://doi.org/10.3390/hydrology10020040 - 1 Feb 2023
Cited by 7 | Viewed by 4102
Abstract
The Caribbean has displayed a capacity to fulfill climate change projections associated with tropical cyclone-related rainfall and flooding. This article describes the hydrometeorological characteristics of Hurricane Fiona in Puerto Rico in September 2022 in terms of measured and interpolated rainfall and observed peak [...] Read more.
The Caribbean has displayed a capacity to fulfill climate change projections associated with tropical cyclone-related rainfall and flooding. This article describes the hydrometeorological characteristics of Hurricane Fiona in Puerto Rico in September 2022 in terms of measured and interpolated rainfall and observed peak flows relative to previous tropical cyclones from 1899 to 2017. Hurricane Fiona ranks third overall in terms of island-wide total rainfall and fourth in terms of daily rainfall. Maximum daily rainfall during Hurricane Fiona exceeded those previously reported (excluding Hurricane María in 2017) in the eastern interior and eastern portions of the island. In terms of peak flows, no value approached the world’s or Puerto Rico’s flood envelope, although 69% of the observations are considered ‘exceptional’. About 26% and 29% of all peak flows were in the 5–10 year and 10–25 year recurrence interval ranges, respectively, yet none matched the 25-year levels. The highest peak flows were concentrated in the central-eastern and southeastern regions. Even though Hurricane María provoked a more extreme hydrometeorological response, some of Hurricane Fiona’s hydro-meteorological characteristics were among the highest ever recorded in Puerto Rico, particularly for the south-central and eastern portions of the island, and it displayed the island’s current level of vulnerability to extreme rainfall. Full article
(This article belongs to the Section Hydrology–Climate Interactions)
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25 pages, 15159 KiB  
Article
Simulation of Friction Fault of Lightly Loaded Flywheel Bearing Cage and Its Fault Characteristics
by Changrui Chen, Zhongmin Deng, Hong Wang and Tian He
Sensors 2022, 22(21), 8346; https://doi.org/10.3390/s22218346 - 31 Oct 2022
Cited by 6 | Viewed by 2457
Abstract
Because of the operating environment and load, the main fault form of flywheel bearing is the friction fault between the cage and the rolling elements, which often lead to an increase in the friction torque of the bearing and even to the failure [...] Read more.
Because of the operating environment and load, the main fault form of flywheel bearing is the friction fault between the cage and the rolling elements, which often lead to an increase in the friction torque of the bearing and even to the failure of the flywheel. However, due to the complex mechanism of the friction fault, the characteristic frequencies often used to indicate cage failure are not obvious, which makes it difficult to monitor and quantitatively judge such faults. Therefore, this paper studies the mechanism of the friction fault of the flywheel bearing cage and establishes its fault feature identification method. Firstly, the basic dynamic model of the bearing is established in this paper, and the friction between the cage and the rolling elements is simulated by the variable stiffness. The influence law of the bearing vibration response reveals the relationship between the periodic fluctuation of cage-rolling element friction failure and the bearing load. After analyzing the envelope spectrum of the vibration data, it was found that when a friction fault occurred between the cage and the rolling element, the rotation frequency component of the cage modulated the rotational frequency component of the rolling element, that is, the side frequency components appeared on both sides of the characteristic frequency of the rolling element (with the characteristic frequency of the cage as the interval). In addition, the modulation frequency components of the cage and rolling element changed with the severity of the fault. Then, a modulation sideband ratio method based on envelope spectrum was proposed to qualitatively diagnose the severity of the cage-rolling element friction faults. Finally, the effectiveness of the presented method was verified by experiments. Full article
(This article belongs to the Section Fault Diagnosis & Sensors)
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13 pages, 1804 KiB  
Article
Developing a Feline Immunodeficiency Virus Subtype B Vaccine Prototype Using a Recombinant MVA Vector
by Luis A. F. Andrade, Alice F. Versiani, Edel F. Barbosa-Stancioli, Jenner K. P. dos Reis, Jordana Grazziela A. C. dos Reis and Flavio G. da Fonseca
Vaccines 2022, 10(10), 1717; https://doi.org/10.3390/vaccines10101717 - 14 Oct 2022
Cited by 1 | Viewed by 2662
Abstract
The feline immunodeficiency virus (FIV) is a retrovirus with global impact and distribution, affecting both domestic and wild cats. This virus can cause severe and progressive immunosuppression culminating in the death of felids. Since the discovery of FIV, only one vaccine has been [...] Read more.
The feline immunodeficiency virus (FIV) is a retrovirus with global impact and distribution, affecting both domestic and wild cats. This virus can cause severe and progressive immunosuppression culminating in the death of felids. Since the discovery of FIV, only one vaccine has been commercially available. This vaccine has proven efficiency against FIV subtypes A and D, whereas subtype B (FIV-B), found in multiple continents, is not currently preventable by vaccination. We, therefore, developed and evaluated a vaccine prototype against FIV-B using the recombinant viral vector modified vaccinia virus Ankara (MVA) expressing the variable region V1–V3 of the FIV-B envelope protein. We conducted preclinical tests in immunized mice (C57BL/6) using a prime-boost protocol with a 21 day interval and evaluated cellular and humoral responses as well the vaccine viability after lyophilization and storage. The animals immunized with the recombinant MVA/FIV virus developed specific splenocyte proliferation when stimulated with designed peptides. We also detected cellular and humoral immunity activation with IFN-y and antibody production. The data obtained in this study support further development of this immunogen and testing in cats. Full article
(This article belongs to the Section Vaccine Design, Development, and Delivery)
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16 pages, 4742 KiB  
Article
Interval Uncertainty Quantification for the Dynamics of Multibody Systems Combing Bivariate Chebyshev Polynomials with Local Mean Decomposition
by Xin Jiang and Zhengfeng Bai
Mathematics 2022, 10(12), 1999; https://doi.org/10.3390/math10121999 - 9 Jun 2022
Cited by 1 | Viewed by 1873
Abstract
Interval quantification for multibody systems can provide an accurate dynamic prediction and a robust reliability design. In order to achieve a robust numerical model, multiple interval uncertain parameters should be considered in the uncertainty propagation of multibody systems. The response bounds obtained by [...] Read more.
Interval quantification for multibody systems can provide an accurate dynamic prediction and a robust reliability design. In order to achieve a robust numerical model, multiple interval uncertain parameters should be considered in the uncertainty propagation of multibody systems. The response bounds obtained by the bivariate Chebyshev method (BCM) present an intensive deterioration with the increase of time history in the interval dynamic analysis. To circumvent this problem, a novel method that combines the bivariate Chebyshev polynomial and local mean decomposition (BC-LMD) is proposed in this paper. First, the multicomponent response of the system was decomposed into the sum of several mono-component responses and a residual response, and the corresponding amplitude and phase of the mono-component were obtained. Then, the bivariate function decomposition was performed on the multi-dimensional amplitude, phase, and residual to transform a high-dimensional problem into several one-dimensional and two-dimensional problems. Subsequently, a low order Chebyshev polynomial can be used to construct surrogate models for the multi-dimensional amplitude, phase, and residual responses. Then, the entire coupling surrogate model of the system can be established, and the response bounds of the system can be enveloped. Illustrative examples of a slider-crank mechanism and a double pendulum are presented to demonstrate the effectiveness of the proposed method. The numerical results indicate that, compared to the BCM, BC-LMD can present a tight envelope in the long time-dependent dynamic analysis under multiple interval parameters. Full article
(This article belongs to the Section C2: Dynamical Systems)
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11 pages, 1625 KiB  
Article
Statics-Based Model-Free Damage Detection under Uncertainties Using Modal Interval Analysis
by Sheng-En Fang and Ji-Yuan Huang
Materials 2020, 13(7), 1567; https://doi.org/10.3390/ma13071567 - 28 Mar 2020
Cited by 6 | Viewed by 2479
Abstract
Deterministic damage detection methods often fail in practical applications due to ever-present uncertainties. Moreover, vibration-based model updating strategies are easily affected by measurement noises and could encounter ill-conditioning problems during inverse solutions. On this account, a model-free method has been proposed combining modal [...] Read more.
Deterministic damage detection methods often fail in practical applications due to ever-present uncertainties. Moreover, vibration-based model updating strategies are easily affected by measurement noises and could encounter ill-conditioning problems during inverse solutions. On this account, a model-free method has been proposed combining modal interval analyses with static measurements. Structural geometrical dimensions, material parameters and external loads are expressed by interval variables representing uncertainties. Mechanical formulas for static responses are then extended to their interval forms, which are subsequently solved using classic interval and modal interval analyses. The analytical interval envelopes of static responses such as deflections and strains are defined by the interval solutions, and damage can be detected when the measured responses intersect the envelopes. By this approach, potential damage can be found in a fast and rough way without any inverse solution process such as model updating. The proposed method has been verified against both numerical and experimental reinforced concrete beams whose strains were taken as the desirable responses. It was found that the strain envelopes provided by modal interval analysis were narrower than those by classic interval analysis. Modal interval analysis effectively avoids the phenomenon of interval overestimation. In addition, the intersection point also identifies the current external load, providing a loading alarm for structures. Full article
(This article belongs to the Special Issue Structural Health Monitoring for Civil Engineering Materials)
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