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The GBr Hypothesis revisited

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第2期10卷 800-809页

作者： Lewis nash Marrietta GA USA

The radical hypothesis concerning the physics of gravitational black-body radiation is placed on a more solid statistical mechanics foundation in this study. As the concepts and formalism in the former presentation are only partially developed and furthermore, suffer from an unfortunate misstep regarding Hawking radiation and the hypothetical gravitational black-body temperature of a parcel or distribution of energy;this paper aims to fill in some of the theoretical gaps in the derivation of the Planck radiation formula for gravity (or non-Euclidean space-time), and there by provide a more complete and transparent quantum theory of thermal gravitational radiation.

关键词： Gravitational Black Body Gravitons Thermal Gravitational radiation Spiral Galaxy rotation Curves

Curved Space-Time at the Planck Scale

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第1期10卷 167-179页

作者： Lewis nash Marietta GA USA

This paper presents a physically plausible and somewhat illuminating first step in extending the fundamental principles of mechanical stress and strain to space-time. Here the geometry of space-time, encoded in the metric tensor, is considered to be made up of a dynamic lattice of extremely small, localized fields that form a perfectly elastic Lorentz symmetric space-time at the global (macroscopic) scale. This theoretical model of space-time at the Planck scale leads to a somewhat surprising result in which matter waves in curved space-time radiate thermal gravitational energy, as well as an equally intriguing relationship for the anomalous dispersion of light in a gravitational field.

关键词： Schwarzschild Space-Time Continuum Mechanics Planck Lattice Gravitational radiation

Deep unfolding based channel estimation for wideband terahertz near-field massive MIMO systems

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Frontiers of Information Technology & Electronic Engineering 2024年第8期25卷 1162-1172页

作者： Jiabao GAO Xiaoming CHEN geoffrey Ye LI College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027China Department of Electrical and Electronic Engineering Imperial College LondonLondon SW 2BUUK

The combination of terahertz and massive multiple-input multiple-output(MIMO)is promising for meeting the increasing data rate demand of future wireless communication systems thanks to the significant band-width and spatial degrees of ***,unique channel features,such as the near-field beam split effect,make channel estimation particularly challenging in terahertz massive MIMO *** one hand,adopting the conventional angular domain transformation dictionary designed for low-frequency far-feld channels will result in degraded channel sparsity and destroyed sparsity structure in the transformed *** the other hand,most existing compressive sensing based channel estimation algorithms cannot achieve high performance and low complexity *** alleviate these issues,in this study,we first adopt frequency-dependent near-field dictionaries to maintain good channel sparsity and sparsity structure in the transformed domain under the near-field beam split ***,a deep unfolding based wideband terahertz massive MIMO channel estimation algorithm is *** each iteration of the approximate message passing-sparse Bayesian learning algorithm,the optimal update rule is learned by a deep neural network(DNN),whose architecture is customized to effectively exploit the inherent channel ***,a mixed training method based on novel designs of the DNN architecture and the loss function is developed to effectively train data from different system *** results validate the superiority of the proposed algorithm in terms of performance,complexity,and robustness.

关键词： Terahertz Massive MIMO Channel estimation Deep learning

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Controlling the properties of surface acoustic waves using graphene

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Nano research 2016年第3期9卷 685-691页

作者： Lokeshwar Bandhu geoffrey r. nash College of Engineering Mathematics and Physical Sciences University of Exeter Exeter EX4 4QF UK

Surface acoustic waves （SAWs） are elastic waves that propagate on the surface of a solid, much like waves on the ocean, with SAW devices used widely in communication and sensing. The ability to dynamically control the properties of SAWs would allow the creation of devices with improved performance or new functionality. However, so far it has proved extremely difficult to develop a practical way of achieving this control. In this paper we demonstrate voltage control of SAWs in a hybrid graphene-lithium niobate device. The velocity shift of the SAWs was measured as the conductivity of the graphene was modulated using an ion-gel gate, with a 0.1% velocity shift achieved for a bias of approximately 1 V. This velocity shift is comparable to that previously achieved in much more complicated hybrid semiconductor devices, and optimization of this approach could therefore lead to a practical, cost-effective voltage-controlled velocity shifter. In addition, the piezoelectric fields associated with the SAW can also be used to trap and transport the charge carriers within the graphene. Uniquely to graphene, we show that the acoustoelectric current in the same device can be reversed, and switched off, using the gate voltage.

关键词： graphene sensors surface acoustic wave charge transport

Optimization of Methylene Blue Dye Adsorption onto Coconut Husk Cellulose Using response Surface Methodology: Adsorption Kinetics, Isotherms and reusability Studies

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Journal of Materials Science and Chemical Engineering 2024年第2期12卷 1-18页

作者： Frank Ouru Omwoyo geoffrey Otieno School of Chemistry and Material Science Technical University of Kenya Nairobi Kenya

In this study, coconut husk cellulose was employed as a cost-effective and environmentally friendly adsorbent to eliminate methylene blue (MB) dye from aqueous solutions. The successful development of response surface methodology paired with a central composite design (rSM-CCD) enabled the optimization and modelling of the adsorption process. The study investigated the individual and combined effects of three variables (pH, contact time, and initial MB dye concentration) on the adsorption of MB dye onto coconut husk cellulose. The developed rSM-CCD model exhibited a remarkable degree of precision in predicting the removal efficiency of MB dye within the specified experimental parameters. This was demonstrated by the strong regression parameters, with an r2 value of 99.79% and an adjusted r2 value of 99.6%. The study depicted that the optimal parameters for attaining a 98.8827% removal of MB dye using coconut husk cellulose were as follows: an initial MB dye concentration of 30 mg∙L−1, contact time of 120 minutes, and pH 7 at a fixed adsorbent dose of 0.5 g. The Freundlich isotherm model provided the most satisfactory description of the equilibrium adsorption isotherms, suggesting that MB dye adsorption onto coconut husk cellulose occurs on a heterogeneous surface. The experimental results demonstrated a strong agreement with the pseudo-second-order kinetics model, indicating that the number of active sites present on the cellulose adsorbent predominantly influences the adsorption process of MB dye. Additionally, the adsorbent made from coconut husk cellulose exhibited the potential to be reused, as it retained its efficiency for a maximum of three cycles of adsorption of MB dye. The results of this study show that coconut husk cellulose has the potential to be an effective and sustainable adsorbent for removing MB dye from aqueous solutions.

关键词： Adsorption Kinetics Isotherms Optimization response Surface Methodology Cellulose

Analysis and Optimization of Operational and Pollutant Attributes of Diesel Engine with CNT-Infused Orange Peel Biodiesel-Diesel Blend Fuel

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Journal of Thermal Science 2024年第2期33卷 761-778页

作者： ranjeet rAI r.r.SAHOO Mechanical Engineering Department GLA UniversityMathura281406India Mechanical Engineering Department IIT(BHU)Varanasi221005India

The current study is performed to find sustainable solutions for the future of transportation and environmental *** conventional methods and experimental design table(L16 Orthogonal Array)techniques have been employed to examine and optimize a diesel-powered engine's operational and pollutant *** L16 Orthogonal Array is obtained through Taguchi's experimental design approach using Minitab 16 *** experimental design incorporated three control variables,namely engine speed,fuel type,and engine load,each with four *** operational parameters,namely brake thermal efficiency(BTE)and brake specific fuel consumption(BSFC),as well as the emission characteristics,including hydrocarbon(HC),carbon monoxide(CO),nitrogen oxide(NO),and smoke emissions,were acquired using the L16 orthogonal array(OA) and subsequently *** utilization of methodologies such as signal-to-noise(S/N) ratio and grey analysis was employed to determine the optimal operational state of the engine to achieve maximum performance while minimizing *** engine's ideal state of operation,in terms of BTE and BSFC,was determined to be at 75% engine load,1000 r/min engine speed,and using 10^(-4)(in vol) carbon nanotube incorporated 20% orange peel biodiesel(OPB20CNT100) blended fuel(A3-B1-C4).The study indicated that engine load significantly influenced BTE and BSFC,with 84.05% and 87.79% contribution factors,*** 25% engine load,1000 r/min,and OPB20CNT100 fuel(A1-B1-C4) CO,smoke,NO,and HC emissions were the *** load affects emissions the *** BSFC increased 3.10% and NO emissions 1.77%.BTE,CO,smoke,and HC emissions decreased by 1.9%,12.29%,47.05%,and 47.22%,respectively,at optimal operating conditions concerning diesel *** study shows that Taguchi-Grey's experimental design optimizes diesel engine operational and pollutant *** outcomes revealed that orange peel biodiesel infused with CNT can replace diesel fuel in a

关键词： Taguchi-Grey method OPB20CNT100 transesterification S/N ratio GrG HC CO and NO

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Metamaterial-based graphene thermal emitter

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Nano research 2018年第7期11卷 3567-3573页

作者： Cheng Shi Nathan H. Mahlmeister Isaac J. Luxmoore geoffrey r. nash College of Engineering Mathematics and PhysicaI Sciences University of Exeter Exeter EX4 4QF UK

A thermal emitter composed of a frequency-selective surface metamaterial layer and a hexagonal boron nitride-encapsulated graphene filament is demonstrated. The broadband thermal emission of the metamaterial （consisting of ring resonators） was tailored into two discrete bands, and the measured reflection and emission spectra agreed well with the simulation results. The high modulation frequencies that can be obtained in these devices, coupled with their operation in air, confirm their feasibility for use in applications such as gas sensing.

关键词： graphene hexagonal boron nitride thermal emitter infrared metamaterial

A highly sensitive electrochemical sensing platform based on Zn-CuGaO@CMK-3 signal amplification for simultaneous detection of the sunset yellow and tartrazine in foods

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Food Science and Human Wellness 2024年

作者： Yongfeng Chen rui Gao Yufeng Sun ruiqiang Wang geoffrey I.N.Waterhouse Xuguang Qiao Zhixiang Xu College of Food Science and Engineering， Shandong Agricultural University Shandong Cayon Testing Co.， LTD. School of Chemical Sciences， The University of Auckland

In this work， a highly sensitive electrochemical sensor based on Zn-doped copper gallium oxide@ordered mesoporous carbon (Zn-CuGaO2@CMK-3) for signal amplification was successfully developed for the simultaneous detection of sunset yellow （SY） and tartrazine （TZ） in foods. Compared with CuGaO2@CMK-3， Zn-CuGaO2@CMK-3 offered enhanced conductivity and catalytic properties owing to the improved carrier density， which was beneficial to the electrooxidation of SY and TZ. Under the optimal testing conditions， the constructed Zn-CuGaO2@CMK-3/GCE sensor offered a wide linear concentration range （0.25 to 100.00 μmol/L） for the detection of both SY and TZ. The limits of detection for SY and TZ were 0.044 μmol/L and 0.059 μmol/L， respectively. recovery experiments were performed in milk， white vinegar and biscuit samples， yielding satisfactory recoveries （82.70%-114.80%）. Furthermore， the sensor was successfully applied to the determination of the SY and TZ residues in two kinds of carbonated drinks， and the results were nearly consistent with those detected by the high performance liquid chromatography （HPLC） method （P＞0.05）.

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Facile synthesis of magnetic covalent organic framework nanocomposites for the enrichment and quantification of trace organophosphorus pesticides in fruit juice

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Food Science and Human Wellness 2024年

作者： Quanbin Fu Xin Sun Lu Liu Hailong Jiang geoffrey I.N.Waterhouse Shiyun Ai rusong Zhao School of Chemical Sciences， The University of Auckland College of Chemistry and Material Science， Shandong Agricultural University Qilu University of Technology (Shandong Academy of Sciences)， Shandong Analysis and Test Center， Key Laboratory for Applied Technology of Sophisticated Analytical Instruments of Shandong Province College of Food Science and Engineering， Shandong Agricultural University

Organophosphorus pesticides (OPPs) in foods pose a serious threat to human health， motivating the development of novel analytical methods for their rapid detection and quantification. A magnetic covalent organic framework (M-COF) adsorbent for the magnetic solid-phase extraction (MSPE) of OPPs from foods was reported. M-COF was synthesized by the Schiff base condensation reaction of 1，3，5-tris (4-aminophenyl)benzene and 4，4-biphenyldicarboxaldehyde on the surface of amino-functionalized magnetic nanoparticles. Density–functional theory (DFT) calculations showed that adsorption of OPPs onto the surface of M-COF involved hydrophobic effects， Van der Waals interactions， π–π interactions， halogen-N bonding， and hydrogen bonding. Combined with gas chromatography–mass spectrometry (GC–MS) technology， the MSPE method features low limits of detection for OPPs (0.002–0.015 μg/L)， good reproducibility (1.45%–6.14%)， wide linear detection range (0.01–1 μg/L， r≥ 0.9935)， and satisfactory recoveries (87.3%–110.4%). The method was successfully applied for the trace analysis of OPPs in spiked fruit juices.

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