Subject: Engineering, Automotive Engineering Keywords: antenna sensor; radio frequency; dipole antenna
Online: 3 November 2019 (18:03:26 CET)
An antenna sensor is proposed to execute dual functions of antenna and sensor in the wireless sensor system, in order to reduce data loss and to increase transmission rate by omitting a certain interface. The as-made sensor was test at a center frequency of 46 MHz for measuring human finger postures using principle of dipole antenna. The antenna sensor was attached on a wearable glove. The results showed that the motion sensor can accurately identify finger angles at 0°, 20°, 40°, 60° and 80°.
ARTICLE | doi:10.20944/preprints202302.0236.v1
Subject: Engineering, Civil Engineering Keywords: Tunnelling; Tunnel Boring Machine; Support pressure; Face stability; Reinforcement Learning; Machine Learning; Deep-Q-Network
Online: 14 February 2023 (06:10:35 CET)
In tunnel excavation with boring machines, the tunnel face is supported to avoid collapse and minimise settlement. This article proposes the use of reinforcement learning, specifically the Deep Q-Network algorithm, to predict the face support pressure. The approach is tested both analytically and numerically. By using the soil properties ahead of the tunnel face and the overburden depth as the input, the algorithm is capable of predicting the optimal tunnel face support pressure, adapting to changes in geological and geometrical conditions.
REVIEW | doi:10.20944/preprints202305.0893.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: lncRNAs; non-coding RNAs; lung cancer; metastasis; biomarkers; therapy resistance
Online: 12 May 2023 (05:24:56 CEST)
Long non-coding RNAs (LncRNAs) are mRNA-like molecules that do not encode for proteins and that are longer than 200 nucleotides. LncRNAs play important biological roles in normal cell physiology and organism development. Therefore, deregulation of their activities is involved in disease processes such as cancer. Lung cancer is the leading cause of cancer-related deaths due to late stage at diagnosis, distant metastasis, and high rates of therapeutic failure. LncRNAs are emerging as important molecules in lung cancer for their oncogenic or tumor suppressive functions. LncRNAs are highly stable in circulation, presenting an opportunity for use as non-invasive and early-stage cancer diagnostic tools. Here, we summarize latest works providing in vivo evidence available for LncRNAs role in cancer development, therapy-induced resistance, and their potential as biomarkers for diagnosis and prognosis, with a focus on lung cancer. Additionally, we discuss current therapeutic approaches to target LncRNAs. The evidence discussed here strongly suggests that investigation of LncRNAs in lung cancer in addition to protein-coding genes will provide a holistic view of molecular mechanisms of cancer initiation, development, and progression, and could open a new avenue for cancer treatment.
ARTICLE | doi:10.20944/preprints202206.0184.v1
Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Over mature shale gas; Magnitude of isotope reversal; CH4 polymerization; CH4 cracking; Mud gas
Online: 13 June 2022 (10:41:14 CEST)
Exploration practices have proven that over mature shale gas exhibits a feature of carbon isotope reversal. The geochemical statistics indicate that the wetness (C2-C5/C1-C5) of shale gas with carbon isotope reversal is less than 1.8%. In addition, the magnitude of carbon isotope reversal (δ13C1- δ13C2) for the over mature shale gas presents a parabolic variation with decreasing wetness. δ13C1-δ13C2 increases with decreasing wetness within a wetness range of 0.9% ~1.8% and then decreases with decreasing wetness at wetness < 0.9%. The CH4 cracking experiment demonstrates that CH4 polymerization occurring in the early stage of CH4 cracking is an important factor involved in isotope reversal of over mature shale gas. Moreover, δ13C1- δ13C2 decreases with an increase in experimental temperature prior to CH4 substantial cracking. The values of δ13C1 and δ13C2 tend to equalize during CH4 substantial cracking. The δ13C1-δ13C2 of mud gas present at different depths during shale gas drilling in Sichuan Basin increases initially, then decreases with further increase in the depth and finally tends to zero, with only a trace hydrocarbon gas being detectable. Statistical data suggests that the shale gas production in Sichuan Basin decreases with the decreasing δ13C1-δ13C2 value and wetness. Thus, δ13C1-δ13C2 and wetness could potentially serve as useful criteria to screen CH4 cracking degree and to determine the largest depth of natural gas exploration. Great care should be taken during shale gas exploration in deeper layers, with wetness and δ13C1-δ13C2 less than 0.2% and 1%, respectively, since very low wetness (<0.2%) and δ13C1-δ13C2 (<1%) might be indicative of CH4 substantial cracking in a geological setting.
Subject: Engineering, Automotive Engineering Keywords: Electro-dynamic suspension; HTS magnets; no-insulation; closed-loop coils; persistent current model
Online: 13 July 2021 (10:08:02 CEST)
Null-flux Electro-dynamic suspension (EDS) system promises to be one of the feasible high-speed maglev systems above 600 km/h. On account of its greater current-carrying capacity, superconducting magnet can provide super-magnetomotive force that is required for null-flux EDS system and cannot be provided by electromagnets and permanent magnets. There is already a relatively mature high-speed maglev technology with low temperature superconducting (LTS) magnets as the core, which works in the liquid helium temperature region (T≤4.2 K). 2-Generation high temperature superconducting (HTS) magnet winded by REBa2Cu3O7−δ (REBCO, RE=rare earth) tapes works above 20 K region and do not need to count on liquid helium which is rare on earth. This paper designed HTS no-insulation closed-loop coils applied for EDS system and energized with persistent current switch. The coils can work at persistent current model and has premier thermal quench self-protection. Besides, a full size double-pancake module was designed and manufactured in this paper, and it was tested in liquid nitrogen. The double-pancake module’s critical current is about 54 A and it is capable of working at persistent current model, whose average decay rate measured in 12 hours is 0.58%/day.
ARTICLE | doi:10.20944/preprints201810.0761.v1
Subject: Engineering, Civil Engineering Keywords: Urban expressway; Cell transmission model; Mandatory merge; Merge section; Diverge section
Online: 1 November 2018 (18:05:19 CET)
Mechanism of traffic congestion generation is more than complicated, due to complex geometric road design and complicated driving behavior at urban expressway in China. We employ Cell transmission model (CTM) to simulate traffic flow spatiotemporal evolution process along the expressway, and reveal the characteristics of traffic congestion occurrence and propagation. Here we apply the variable-length-cell CTM to adapt the complicated road geometry and configuration, and propose the merge section CTM considering drivers' mandatory lane-changing and other unreasonable behavior at on-ramp merge section, and propose the diverge section CTM considering queue length end extending expressway mainline to generate dynamic bottleneck at diverge section. In the new improved CTM model, we introduce merge ratio and diverge ratio to describe the effect of driver behavior at merge and diverge section. We conduct simulation on the real urban expressway in China, results show that merge section and diverge section are the original location of expressway traffic congestion generation, on/off-ramp traffic flow has great effect on expressway mainline operation. When on-ramp traffic volume increases by 40%, merge section delay increases by 35%. And when off-ramp capacity increases by 100 veh/hr, diverge section delay decreases about by 10%, which proves the strong interaction between expressway and adjacent road networks . Our results provide the underlying insights of traffic congestion mechanism in urban expressway in China, which can be used to better understand and manage this issue.
ARTICLE | doi:10.20944/preprints201810.0601.v1
Subject: Engineering, Civil Engineering Keywords: support vector machine; travelling time; intelligent transportation system; artificial fish swarm algorithm; big data
Online: 25 October 2018 (10:48:45 CEST)
Freeway travelling time is affected by many factors including traffic volume, adverse weather, accident, traffic control and so on. We employ the multiple source data-mining method to analyze freeway travelling time. We collected toll data, weather data, traffic accident disposal logs and other historical data of freeway G5513 in Hunan province, China. Using Support Vector Machine (SVM), we proposed the travelling time model based on these databases. The new SVM model can simulate the nonlinear relationship between travelling time and those factors. In order to improve the precision of the SVM model, we applied Artificial Fish Swarm algorithm to optimize the SVM model parameters, which include the kernel parameter σ, non-sensitive loss function parameter ε, and penalty parameter C. We compared the new optimized SVM model with Back Propagation (BP) neural network and common SVM model, using the historical data collected from freeway G5513. The results show that the accuracy of the optimized SVM model is 17.27% and 16.44% higher than those of the BP neural network model and the common SVM model respectively.
ARTICLE | doi:10.20944/preprints202308.0414.v1
Subject: Engineering, Energy And Fuel Technology Keywords: superhydrophobic surface treatment; electric vehicle; heat pump; microchannel heat exchanger; coefficient of performance
Online: 4 August 2023 (11:36:40 CEST)
Battery-powered electric vehicles (EVs) have emerged as an environmentally friendly and efficient alternative to traditional internal combustion engine vehicles, while their single-charge driving distances under cold conditions are significantly limited due to the high energy consumption of heating systems. Heat pumps can provide an effective heating solution for EVs, but their coefficient of performance (COP) is hampered by heat transfer deterioration due to frost accumulation. This study proposes a solution to this issue by introducing a microchannel heat exchanger (MHE) with superhydrophobic surface treatment (SHST) as a heat pump evaporator. A computational-fluid-dynamics MHE model and a dynamic heat pump model are developed and rigorously validated to examine the detrimental impact of frost accumulation on heat transfer, airflow resistance, and heat pump performance. When the frost layer thickness is 0.8 mm at a given air-side velocity of 1.0 m/s, the air-side heat transfer coefficient can be reduced by about 75%, and the air-side pressure drop sharply increases by 28.4 times. As frost thickness increases from 0 to 0.8 mm, the heating effect drops from 3.97 to 1.82 kW, and the system COP declines from 3.17 to 2.30. Experimental results show that the frost thickness of the MHE with SHST reaches approximately 0.4 mm after 30 minutes, compared to that of 0.8 mm of the MHE without SHST, illustrating the defrosting capability of the superhydrophobic coating. The study concludes by comparing the performance of various heating methods in EVs to highlight the advantages of SHST technology. As compared to traditional heat pumps, the power consumption of the proposed system is reduced by 48.7% due to the defrosting capability of the SHST. Moreover, the single-charge driving distance is extended to 327.27 km, an improvement of 8.99% over the heat pump without SHST.
ARTICLE | doi:10.20944/preprints202210.0175.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: CNT; in-situ repaiir; Fractsure toughness; Cohesive interface modelling
Online: 12 October 2022 (10:29:38 CEST)
This study aims to develop an in-situ field repair approach, special for aircraft composite structures, to enhance the interlaminar toughness of plain woven composites (PWCs) by adding multi-walled carbon nanotubes (MWCNTs). MWCNTs are dispersed at each interface between prepreg layers by means of solvent spraying with the density is 1.58 g/m2. And then, the layers are stacked with the predefined sequence and cured at 120℃ and 1 bar pressure using the heat repairing instrument. Moreover, double cantilever beam (DCB) standard test is used to investigate the interlaminar toughening effect due to the MWCNTs. For comparison, original samples are also prepared, the results indicate that the introduction of MWCNTs can favorably enhance the interlaminar toughness of PWCs at field repair approach and the Mode I fracture energy release rate GIC increases by 102.92%. Based on finite element method (FEM) of continuum damage mechanics, the original and MWCNTs toughening specimen under DCB Mode I fracture are modeled and analyzed. The simulation and experiment are in good agreement. Finally, the toughening mechanism of MWCNTs is explored by scanning electron microscope (SEM), it is founded that a large amount of Fiber-matrix (F-M) interface debonding and matrix cracking of mountain shape are the major modes of fracture accompanied with few fiber breakage and matrix peeling off for the MWCNTs toughening specimens.
ARTICLE | doi:10.20944/preprints202309.1907.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: Bisphenol A diglycidyl ether; derivatives; broad-spectrum polyclonal antibodies; AuNPs; immunochromatographic; canned food
Online: 28 September 2023 (17:24:06 CEST)
Bisphenol A diglycidyl ether (BADGE) is widely existed in the inner coating of canned foods. It migrates into food and generate various derivatives in the process of storage, such as Bisphenol A (2, 3-dihydroxypropyl) glycidyl ether (BADGE·H2O), Bisphenol A (3-chloro-2-hydroxypropyl) glycidyl ether (BADGE·HCl) and Bisphenol A (3-chloro-2-hydroxypropyl) (2, 3-dihydroxypropyl) glycidyl ether (BADGE·HCl·H2O), which have negative effects on human health. A gold nanoparticle-based immu-nochromatographic assay for simultaneous detection of BADGE and its derivatives was developed by using a broad-spectrum polyclonal antibody, and the detection can be finished in 15 min. The visuali-zation of results was processed by Adobe Photoshop CC software to achieve quantitative analysis and the detection limit (IC15) is 0.97ng/mL. The recoveries of BADGE and its derivatives at various spiking levels in canned food samples ranged from 79.86% to 93.81%. The detection results of the proposed immu-nochromatographic assay were also validated by HPLC analysis, and got good consistency (R2=0.9580).
ARTICLE | doi:10.20944/preprints202007.0644.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: Lagrangian particle microphysics; polarimetric radar; outer rain bands; hurricane Dorian
Online: 26 July 2020 (16:59:15 CEST)
The availability of high quality surface observations of precipitation and volume observations by polarimetric operational radars make it possible to constrain, evaluate and validate numerical models with a wide variety of microphysical schemes. In this article, a novel particle-based Monte-Carlo microphysical model (called “McSnow”) is used to simulate the outer rain bands of Hurricane Dorian which traversed the densely instrumented precipitation research facility operated by NASA at Wallops Island, Virginia. The rain bands showed steady stratiform vertical profiles with radar signature of dendritic growth layers near −15 °C and peak reflectivity in the bright band of 55 dBZ along with polarimetric signatures of wet snow with sizes inferred to exceed 15 mm. A 2D-video disdrometer measured frequent occurrences of large drops >5 mm and combined with an optical array probe the drop size distribution was well-documented in spite of uncertainty for drops <0.5 mm due to high wind gusts and turbulence. The 1D McSnow control run and four numerical “experiments” were conducted and compared with observations. One of the main findings is that even at the moderate rain rate of 10 mm/h collisional breakup is essential for the shape of the drop size distribution.
ARTICLE | doi:10.20944/preprints201807.0477.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: hyper-coal, hydrogenation, spinnable pitch, carbon fiber
Online: 25 July 2018 (10:19:51 CEST)
The proper hydrogenation of Hyper-coal (HPC) using 1, 2, 3, 4-tetrahydroquinoline (THQ) was able to decrease the oxygen content and adjust the molecular structure of HPC for preparing the spinnable pitch with high softening point (SP). The spinnable pitch prepared from the THQ-soluble (QS) fraction of HPC as a precursor consisted more naphthenic carbon groups than that prepared from the 1-methylnaphthalene (1-MN) soluble (MNS) fraction of HPC. The HPC-QS derived pitch showed excellent spinnability even the SP of 260°C, and the tensile strength of the resultant carbon fiber was up to 1350 MPa with a diameter around 8 µm by only heat treatment at 800°C for 5 min.
ARTICLE | doi:10.20944/preprints202308.1034.v1
Subject: Engineering, Architecture, Building And Construction Keywords: Authentic learning; Experiential learning; Real materials; Immersive technologies; Virtual Reality; Augmented Reality
Online: 15 August 2023 (02:40:45 CEST)
Authentic learning opportunities that simulate full scale design and construction experiences using real materials offer ideal experiential learning environments for construction and civil engineering students by challenging students to apply building concepts in practical settings. However, the excessive cost of real building materials required for this mode of education limits access to the vast majority of students. As a result, educational researchers have explored potential alternatives to provide cost-effective experiential learning through activities using mock-up materials (e.g., plastic straws, popsicle sticks) and simulation of experiences using immersive technologies (e.g., virtual reality or augmented reality). While some of these alternatives approximate the environment and others provide physical interaction with mock-up materials, the lack of authenticity in the building materials used introduces some apparent differences between the “authentic” learning environments and their cost-effective approximations. Therefore, this research aims to identify the learning processes reported by students and faculty who participated in authentic learning experiences to understand the ways in which this mode of education offers unique value to construction education. Their interview responses illustrated characteristics of authentic learning experiences that were believed to be critical to the learning process, some of which included: working in groups; interdisciplinary participants; and use of real construction materials. Although some of these characteristics are intrinsically linked to the use of real materials, others do not explicitly refer to interaction with real materials. This may indicate to aspects of the authentic learning processes that educational researchers can strategically target through more cost-effective learning environments like virtual and augmented reality. The contribution of this paper is in identifying the characteristics of authentic learning experiences that may guide educational investment and research innovations that aim to replicate some of these learning experiences through more accessible learning environments.
REVIEW | doi:10.20944/preprints202306.0919.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: P. ginseng; chemical component; ginsenoside; Alzheimer's disease; signaling pathways; spatial metabolomics
Online: 13 June 2023 (10:02:30 CEST)
Panax ginseng C. A. Meyer (P. ginseng), has been widely used in traditional Chinese medicine (TCM). It contains a number of chemical components and possesses a variety of pharmacological activities. Alzheimer's disease (AD) is neurodegenerative disease that creates a huge burden on the lives and health of individuals. In recent years, studies have indicated that the chemical components of P. ginseng, especially ginsenosides, play a pronounced positive role in the prevention and treatment of neurological diseases. This review aimed to summarize currently studies on chemical components and the mechanisms action in AD intervention treatment of P. ginseng, especially ginsenosides. In this review, the components of P. ginseng and their respective active effects were first introduced. Then the key molecular mechanisms and signaling pathways of P. ginseng were introduced, and its different active ingredients in the prevention and treatment of Alzheimer's disease-related pathogenesis were also summarized from the pathogenesis of AD Aβ generation and aggregation, hyperphosphorylation of tau protein，oxidant stress，neuroinflammation，mitochondrial damage，disorder of neurotransmitter and gut microbiota. Signaling pathway networks related to the action of ginseng active ingredients was constructed, which could serve as a therapeutic target for Alzheimer's disease. In addition to a detailed report on P. ginseng in improving Alzheimer's disease-related pathogenesis, the application of the current technology, spatial metabonomics in AD therapeutics and diagnostics were later discussed. Spatial metabonomics could be applied to investigate the multi-target intervention of P. ginseng on Alzheimer's disease. Research perspectives for the study of P. ginseng in the treatment of Alzheimer's disease were provided for further studies.
BRIEF REPORT | doi:10.20944/preprints202309.1217.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Dracaena braunii; Colletotrichum gloeosporioides; internal transcribed spacer (ITS); glyceraldehyde-3-phosphate dehydrogenase (GAPDH); molecular characterization; pathogenicity test
Online: 19 September 2023 (13:29:11 CEST)
Lucky bamboo (Dracaena sanderiana hort. ex Mast. = Dracaena braunii) is a domestic species widely cultivated for ornamental purposes in China. In March 2022, a severe occurrence of anthracnose disease was observed on the stems of lucky bamboo plants in a greenery retail store located in Nanjing, Jiangsu Province, China. The morphological characteristics of isolates obtained from diseased stem tissues were identical with those described for Colletotrichum species. Based on multilocus phylogenetic analysis with the internal transcribed spacer (ITS), actin (ACT) gene, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, the pathogen was identified as Colleto-trichum gloeosporioides (Penz.) Penz. & Sacc. Pathogenicity was verified by mycelial plug-inoculating stem cuttings of one-year-old lucky bamboo plants and spray-inoculating whole one-year-old lucky bamboo plants, respectively. Koch’s postulates were fulfilled by the re-isolation of C. gloeosporioides from symptomatic tissues. To the best of our knowledge, this report describes the first time that C. gloeosporioides was observed to cause anthracnose on lucky bamboo in China.
ARTICLE | doi:10.20944/preprints201804.0372.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: hemp bast fibre; hydrothermal processing; KOH activation; activated carbon
Online: 28 April 2018 (12:29:14 CEST)
Synthesis of activated carbon from waste biomass is of current interest towards sustainability. The properties of biomass derived activated carbon largely depends on the carbonization process. This study reports preparing extremel high surface area mesoporous activated carbon from hemp bast fibre using hydrothermal processing. Processing in hot water (390-500oC), then activation using KOH and NaOH was investigated at different loading ratios. The described approach was found to enhance the mesoporosity (centered at 3.0 to 4.5 nm) of the hemp derived activated carbon (HAC) from activation (confirmed by BJH pore size distribution and TEM imaging). BET results showed that the product has an extremely high surface area (2425 m2/g) while the surface functional groups (-OH, COOH, C=C/C-C) were confirmed and quantified by XPS and FTIR results. Increasing KOH concentration was found to enhance the surface area with an optimum biochar to KOH ratio of 1:3. The crystallite domain size of HAC was determined using Raman spectroscopy of different wavelengths. The procedure described in this study is an environmentally friendly scalable route for the mass production of activated carbon using hemp fiber.
ARTICLE | doi:10.20944/preprints202306.1035.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Fatty Acid Metabolism; Immunotherapy; Breast cancer; Tumor microenvironment; Single-cell sequencing
Online: 14 June 2023 (09:40:33 CEST)
Abstract: (1) Background: Cancer immune escape is associated with the metabolic reprogramming of TME, and combining metabolic targets with immunotherapy has great potential to improve clinical outcomes. Among all metabolic processes, lipid metabolism, especially fatty acid (FA) metabolism, has a huge role in cancer cell survival, migration, and proliferation, but its mechanism and role in the tumor immune microenvironment remain to be investigated. (2) Methods: We comprehensively analyzed 309 fatty acid-related genes, screened 121 different genes, and used one-way COX regression to select 15 genes with prognostic impact. Systematically evaluated the correlation between FMGs modification patterns and Tumor Microenvironment Infiltration, prognosis, and Immunotherapy. The FMGs-Score was constructed to quantify the FMGs modification patterns using principal component analysis. (3) Results: Three clusters based on FMGs-related genes were demonstrated in breast cancer, with three patterns of distinct immune cell infiltration and biological behavior. An FMGsScore signature was constructed to reveal that patients with a low FMGsScore had higher immune checkpoint expression, higher immune checkpoint inhibitor (ICI) scores, increased immune microenvironment infiltration, better survival advantage, and were more sensitive to immunotherapy than those with a high FMGsScore. Finally, the expression and function of the signature key gene NDUFAB1 were examined by in vitro experiments. (4) Conclusions: This study significantly demonstrates the non-negligible role of FMGs in the immune microenvironment of breast cancer, and that FMGsScores can be used to guide the prediction of immunotherapy in breast cancer patients. In in vitro experiments, knockdown of the NDUFAB1 gene resulted in reduced proliferation and migration of MCF-7 cell lines.
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: wheat; UAV image; color index; texture feature index; biomass
Online: 26 December 2019 (12:27:49 CET)
In order to realize rapid and nondestructive monitoring of wheat biomass in field, field experiments based on different densities, nitrogen fertilizer and variety treatments were studied. RGB images of wheat in the main growth stage were obtained by UAV, and wheat color and texture feature indices were obtained by image processing, and wheat biomass was obtained by field sampling in the same period. Then the relationship between different color and texture feature indices and wheat biomass was analyzed to select the color and texture feature index suitable for wheat biomass estimation. The results showed that there was a high correlation between image color index and wheat biomass in different stages, and most of them reached a very significant correlation level. However, the correlation between image texture feature index and wheat biomass was poor, only a few indexes reached significant or extremely significant correlation level. Based on the above results, the color indices with the highest correlation to wheat biomass or the combining indices of color and texture feature in different growth stage were used to construct estimation model of wheat biomass. The models were validated using independently measured biomass data, and the correlation between simulated and measured values reached the significant level, RMSE were smaller. This indicated that the estimated results by the models were reliable and accurate. It also showed that the estimation models of wheat biomass combined with color and texture feature indices of UAV image were better than the single color index models. The results would provide a new method for real-time monitoring of wheat field growth and biomass estimation.