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Navigation Finsler metrics on a gradient Ricci soliton

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applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 266-275页

作者： LI Ying MO Xiao-huan WANG Xiao-yang Department of applied Mathematics Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of pure and applied Mathematics School of Mathematical SciencesPeking UniversityBeijing 100871China School of Mathematics and Statistics Beijing Institute of TechnologyBeijing 100081China

In this paper,we study a class of Finsler metrics defined by a vector field on a gradient Ricci soliton.We obtain a necessary and sufficient condition for these Finsler metrics on a compact gradient Ricci soliton to be of isotropic S-curvature by establishing a new integral inequality.Then we determine the Ricci curvature of navigation Finsler metrics of isotropic S-curvature on a gradient Ricci soliton generalizing result only known in the case when such soliton is of Einstein type.As its application,we obtain the Ricci curvature of all navigation Finsler metrics of isotropic S-curvature on Gaussian shrinking soliton.

关键词： gradient Ricci soliton navigation Finsler metric isotropic S-curvature Ricci curvature Gaussian shrinking soliton

A new quantity in Finsler geometry

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Science China Mathematics 2024年第4期67卷 883-890页

作者： Xiaohuan Mo Xiaoyang Wang Key Laboratory of pure and applied Mathematics School of Mathematical SciencesPeking UniversityBeijing 100871China School of Mathematics and Statistics Beijing Institute of TechnologyBeijing 100081China

In this paper,we study a new Finslerian quantity■defined by the T-curvature and the angular metric tensor.We show that the■-curvature not only gives a measure of the failure of a Finsler metric to be of scalar flag curvature but also has a vanishing trace.We find that the■-curvature is closely related to the Riemann curvature,the Matsumoto torsion and theΘ-curvature.We solve Z.Shen’s open problem in terms of the■-curvature.Finally,we give a global rigidity result for Finsler metrics of negative Ricci curvature on a compact manifold via the■-curvature,generalizing a theorem previously only known in the case of negatively curved Finsler metrics of scalar flag curvature.

关键词： Finsler metric Finslerian quantity T-curvature -curvature Randers metric

Biosensors and Bioanalytical Methods for Environmental Analysis under Development at pure and applied biochemistry in Lund

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Biosensors and Bioanalytical Methods for Environmental Analy...

GGA + U Study of the Optical Properties of α-BeH2

2007中国科协年会

作者： Bengt Danielsson pure and applied biochemistry Lund University Sweden

This overview presents developments of bioanalytical techniques including biosensors that can be of interest to environmental analysis.Thermal biosensors have a long tradition in Lurid and have found many applications in environmental monitoring involving enzymes and cells,both for direct measurements and indirectly by inhibition. Recent applications involve use of molecularly imprinted polymers (MIPs).

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Open Journal of applied Sciences 2024年第6期14卷 1507-1511页

作者： Uko Ofe Department of pure and applied Physics Veritas University Abuja Nigeria

The optical properties of α-BeH2 in an Orthorhombic crystal structure with the space group (Ibam) are investigated. We have calculated the optical properties including dielelectric function, refractive index and extinction coefficient, using density functional approach. A theoretical explanation of the relationship between the dielectric function and other optical constants has been provided. Furthermore, the real and imaginary components of the dielectric function have been examined. The effects of the exchange-correlation potentials (GGA and GGA + U) applied on this compound’s absorption peaks and edges have also been investigated. It was found that using the GGA + U approximation caused the conduction band to shift, which in turn caused the initial absorption peak to shift.

关键词： Dielectric Function Optical Properties GGA and GGA + U Approximations

Enhancing Patients Outcomes and Infection Control through Smart Indoor Air Quality Monitoring Systems

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Journal of Computer and Communications 2024年第6期12卷 25-37页

作者： Othniel Ojochonu Abalaka Joe Essien Calistus Chimezie Martin Ogharandukun Department of Computer Science Veritas University Abuja Nigeria Department of pure and applied Physics Veritas University Abuja Nigeria

Air pollution poses a critical threat to public health and environmental sustainability globally, and Nigeria is no exception. Despite significant economic growth and urban development, Nigeria faces substantial air quality challenges, particularly in urban centers. While outdoor air pollution has received considerable attention, the issue of indoor air quality remains underexplored yet equally critical. This study aims to develop a reliable, cost-effective, and user-friendly solution for continuous monitoring and reporting of indoor air quality, accessible from anywhere via a web interface. Addressing the urgent need for effective indoor air quality monitoring in urban hospitals, the research focuses on designing and implementing a smart indoor air quality monitoring system using Arduino technology. Employing an Arduino Uno, ESP8266 Wi-Fi module, and MQ135 gas sensor, the system collects real-time air quality data, transmits it to the ThingSpeak cloud platform, and visualizes it through a user-friendly web interface. This project offers a cost-effective, portable, and reliable solution for monitoring indoor air quality, aiming to mitigate health risks and promote a healthier living environment.

关键词： Artificial Intelligence Air Pollution Infection Control Data Transmission Data Acquisition Sensors

Heat and Mass Transfer for a Nanofluid Flow in Fluidized Bed Dryer in Presence of Induced Magnetic Field

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Journal of applied Mathematics and Physics 2024年第4期12卷 1401-1425页

作者： Kiptum J. Purity Mathew N. Kinyanjui Edward R. Onyango Pan African University Institute for Basic Sciences Technology and Innovation Nairobi Kenya Department of pure and applied Mathematics Jomo Kenyatta University of Agriculture and Technology Nairobi Kenya

This research entails the study of heat and mass transfer of nanofluid flow in a fluidized bed dryer used in tea drying processes in presence of induced magnetic field. A mathematical model describing the fluid flow in a Fluidized bed dryer was developed using the nonlinear partial differential equations. Due to their non-linearity, the equations were solved numerically by use of the finite difference method. The effects of physical flow parameters on velocity, temperature, concentration and magnetic induction profiles were studied and results were presented graphically. From the mathematical analysis, it was deduced that addition of silver nanoparticles into the fluid flow enhanced velocity and temperature profiles. This led to improved heat transfer in the fluidized bed dryer, hence amplifying the tea drying process. Furthermore, it was noted that induced magnetic field tends to decrease the fluid velocity, which results in uniform distribution of heat leading to efficient heat transfer between the tea particles and the fluid, thus improving the drying process. The research findings provide information to industries on ways to optimize thermal performance of fluidized bed dryers.

关键词： Heat Transfer Induced Magnetic Field Nanofluid Fluidized Bed Dryer

Thermally activated delayed fluorescence carbazole-triazine dendrimer with bulky substituents

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Aggregate 2024年第1期5卷 236-243页

作者： Hiroki Ikebe Kohei Nakao Eri Hisamura Minori Furukori Yasuo Nakayama Takuya Hosokai Minlang Yang Guanting Liu Takuma Yasuda Ken Albrecht Interdisciplinary Graduate School of Engineering Sciences Kyushu UniversityFukuokaJapan Institute for Materials Chemistry and Engineering Kyushu UniversityKasugaJapan Department of pure and applied Chemistry Graduate School of Science and TechnologyTokyo University of ScienceNodaChibaJapan National Metrology Institute of Japan(NMIJ) National Institute of Advanced Industrial Science and Technology(AIST)TsukubaIbarakiJapan Institute for Advanced Study Kyushu UniversityNishi-kuFukuokaJapan

Carbazole-triazine dendrimers with a bulky terminal substituent were synthesized,and the thermally activated delayed fluorescence(TADF)property was investigated.Compared to unsubstituted carbazole dendrimers,dendrimers with bulky terminal substituents showed comparable to better photoluminescence quantum yields(PLQY)in neat films.Phenylfluorene(PF)-substituted dendrimers showed the highest PLQY of 81%,a smallΔEst of 0.06 eV,and the fastest reverse intersystem crossing(RISC)rate of∼1×10^(5 )s^(−1) compared to other dendrimers.Phosphorescence measurements of dendrimers and dendrons(fragments)indicate that the close proximity of the triplet energy of phenylfluorene-substituted carbazole dendrons(^(3)LE)to that of phenylfluorene-substituted dendrimers(^(1)CT,^(3)CT)contributes to RISC promotion and improves TADF efficiency.Terminal modification fine-tunes the energy level and suppresses intermolecular interactions,and this study provides a guideline for designing efficient solution-processable and non-doped TADF materials.

关键词： dendrimer OLED TADF 1 INTRODUCTION Thermally activated delayed fluorescence(TADF)materials which are inexpensive and highly efficient alternatives to fluorescent

Hydromagnetic Squeezing Nanofluid Flow between Two Vertical Plates in Presence of a Chemical Reaction

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Journal of applied Mathematics and Physics 2024年第1期12卷 126-146页

作者： Benjamin Matur Madit Jackson K. Kwanza Phineas Roy Kiogora Department of Mathematics Pan African University Institute of Basic Sciences Technology and Innovation Juja Kenya Department of pure and applied Mathematics Jomo Kenyatta University of Agriculture and Technology Juja Kenya

In this study, Hydromagnetic Squeezing Nanofluid flow between two vertical plates in presence of a chemical reaction has been investigated. The governing equations were transformed by similarity transformation and the resulting ordinary differential equations were solved by collocation method. The velocity, temperature, concentration and magnetic induction profiles were determined with help of various flow parameters. The numerical scheme was simulated with aid of MATLAB. The results showed that increasing the squeeze number only boosts velocity and concentration while lowering temperature. Conversely, increasing the Hartmann number, Reynold’s magnetic number, Eckert number and Thermal Grashof number generally increases temperature but decreases both velocity and concentration. Chemical reaction rate and Soret number solely elevate concentration while Schmidt number only reduces it. The results of this study will be useful in the fields of oil and gas industry, plastic processing industries, filtration, food processing, lubrication system in machinery, Microfluidics devices for drug delivery and other related fields of nanotechnology.

关键词： Hydromagnetic Squeezing Flow Nanofluid Variable Magnetic Field Chemical Reaction

Machine Learning Models for Heterogenous Network Security Anomaly Detection

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Journal of Computer and Communications 2024年第6期12卷 38-58页

作者： Mercy Diligence Ogah Joe Essien Martin Ogharandukun Monday Abdullahi Department of Computer Science Veritas University Abuja Nigeria Department of pure and applied Physics Veritas University Abuja Nigeria Department of Computer Science Air Force Institute of Technology Kaduna Nigeria

The increasing amount and intricacy of network traffic in the modern digital era have worsened the difficulty of identifying abnormal behaviours that may indicate potential security breaches or operational interruptions. Conventional detection approaches face challenges in keeping up with the ever-changing strategies of cyber-attacks, resulting in heightened susceptibility and significant harm to network infrastructures. In order to tackle this urgent issue, this project focused on developing an effective anomaly detection system that utilizes Machine Learning technology. The suggested model utilizes contemporary machine learning algorithms and frameworks to autonomously detect deviations from typical network behaviour. It promptly identifies anomalous activities that may indicate security breaches or performance difficulties. The solution entails a multi-faceted approach encompassing data collection, preprocessing, feature engineering, model training, and evaluation. By utilizing machine learning methods, the model is trained on a wide range of datasets that include both regular and abnormal network traffic patterns. This training ensures that the model can adapt to numerous scenarios. The main priority is to ensure that the system is functional and efficient, with a particular emphasis on reducing false positives to avoid unwanted alerts. Additionally, efforts are directed on improving anomaly detection accuracy so that the model can consistently distinguish between potentially harmful and benign activity. This project aims to greatly strengthen network security by addressing emerging cyber threats and improving their resilience and reliability.

关键词： Cyber-Security Network Anomaly Detection Machine Learning Random Forest Decision Tree Gaussian Naive Bayes