Physical Sciences and Mathematics Commons^™

Workability And Compressive Strength Of Steel Slag Powder-Cement-Based Self-Compacting Iron Tailings Mortar, Yang Zaiqing, Jin Shengji, Zhang Xiaogang, Sheng Guohua

Journal of China & Foreign Highway

Steel slag and iron tailings are typical industrial solid waste.Their large-scale stockpiling occupies a significant amount of land and has a negative impact on the environment.To respond to the Guiding Opinions on the Comprehensive Utilization of Bulk Solid Waste in the 14th Five Year Plan and expand the use of steel slag powder and iron tailings sand as concrete admixtures and aggregates,this study prepared steel slag powder-cement-based self-compacting iron tailings mortar.The workability index of mortar was determined through two tests:the flow expansion test and the V-shaped funnel test.Additionally,the compressive strength of the mortar was measured using a servo press.The results …

Mechanical Properties Of Transition Section Of Cable-Stayed Bridge With Kilometer-Scale Steel-Uhpc Composite Girders, Li Qiu, Zhi Haitao, Peng Yanqing, Peng Jianxin, Yuan Qin, Wu Xuewei

Journal of China & Foreign Highway

To study the mechanical properties of the steel-concrete composite section between steel box girders and steel-ultra-high performance concrete (UHPC ) composite girders,the Guanyinsi Yangtze River Bridge with a main span of 1 160 m was used as the background.Through refined finite element modeling,the stress characteristics under the most unfavorable load conditions and transmission mechanism of the steel-concrete composite section were analyzed,and the main factors affecting the stress of the composite section were discussed.The results indicate that under the most unfavorable load conditions,the stress of each component in the steel-concrete composite section is within 160.4 MPa,which is lower than the material …

Wind Tunnel Test Study On Wind-Resistant Performance Of Shuangliu Yangtze River Bridge, Li Xiukun, Wu Xuewei, Yang Can, Peng Xiaobin, Huang Zhiwen

Journal of China & Foreign Highway

The main bridge of Shuangliu Yangtze River Bridge on the Xingang Expressway in Wuhan City is a single-span suspension bridge with a main span of 1 430 m and a bridge tower of 272.75 m.The stiffening girder is in the form of a closed flat steel box girder with a width of 50.5 m.In order to study the wind-resistant performance of the bridge during operation,the performance of vortex-induced vibration of the girder was tested through wind tunnel tests of section model with two different geometric scales of 1∶60 and 1∶30,respectively.The sensitivity of the vortex-induced vibration response to the structural damping …

Application Of Forward-Ba Ck Ana Lysis And Difference Iteration Method For Solving Initial Cable Tension Of Arch Bridge, Xu Yufeng, Li Zihui, Zhang Zhantao

Journal of China & Foreign Highway

This article presented a method that c ombined the forward-back analysis method and the difference iteration method to solve the initial cable tension according to the state of a built bridge for an arch bridge.Given the known target state of the bridge,a reasonable set of initial cable tensions was determined as the initial value of iteration by the forward-back method.These initial tensions were then applied to the calculation model based on the actual construction process.Through the difference iteration method,the initial cable tensions were optimized.The results show that the method can effectively determine the final cable tension that meets engineering precision …

Experimental Study On Bending And Shear Performance Of Joint With Looped Reinforcement In Prefabricated Components, Liu Zhiquan, Hu Ke, Shi Xuefei, Zhong Yuzhuo

Journal of China & Foreign Highway

A joint with looped reinforcement is a type of steel bar connection structure with wet joints characterized by quick construction.In order to study the bending and shear stress performance and load-bearing capacity characteristics of the wet joints,four bearing capacity tests for bending and shear were designed and conducted for common application scenarios.The load,strain,and displacement changes of the specimens during the test process were tested,and the failure characteristics,load–displacement changes,and ultimate bearing capacity of this type of wet joint were analyzed.The results show that the wet joint with looped reinforcement has good ductility and conforms to the design principles of reinforced concrete.The …

Bending Moment Calculation And Reinforcement Recommendations For Cast-In-Place Cover Slabs In Slab Culverts, Li Yukun, Wan Kecheng, Fu Fulin

Journal of China & Foreign Highway

To address the complexity and lack of practical methods for calculating bending moments of cast-in-place cover slabs in slab culverts,the slabs were simplified as one-way slabs with a pair of opposing edges simply supported and the other pair of edges free.Theoretical formulas for calculating the bending moments within the slabs under uniformly distributed loads were derived using elastic theory.The accuracy of the theoretical formulas was validated through case studies via finite element software.Various combinations of length,width,and fill heights exist in highway projects,making the use of theoretical formulas for bending moment calculations cumbersome.Therefore,a simplified method for calculating maximum bending moments in …

Research On Whole-Hole Testing Technology For Under-Anchor Tension In Prestressed Concrete Girders, Zhu Jianzhao, Dong Hao, Gu Jungang, Feng Lu, Li Shuyang, Zhang Shoulong, Chen Chaung

Journal of China & Foreign Highway

This study aims to propose a new testing method,namely whole-hole back-pull testing technology,to reduce costs and increase efficiency in under-anchor tension testing,effectively addressing the engineering challenges of large testing volume and tight schedules.Based on the principle of the traditional back-pull method,the mechanism of whole-hole back-pull testing technology was explained through theoretical analysis and formula derivation.Technical optimization was carried out in conjunction with experimental research,and a complete application method was proposed.A feasibility analysis was carried out.The study obtained the simplified mechanical model and typical test curves of the whole-hole back-pull testing technology and proposed a formula and application method for determining …

Settlement Mechanism And Re Inforcement Measure For Large-Diameter And Small-Clearance Parallel P Ipe Jacking Undercrossing Complex Building, Tang Gang, Huang Wen Jie, Zhang Wenbo, Li Wenjie, Liang Bin

Journal of China & Foreign Highway

This study aims to study the settlem ent changes and distribution of various parts of a complex building during the construction of a large-diameter and small-clearance parallel pipe jacking undercrossing complex building.On the basis of the pipe jacking project of water quality guarantee engineering 2# for Tiegang –Shiyan Reservoir in Shenzhen,the settlement mechanism of pipe jacking undercrossing construction was analyzed.Through numerical simulation,the influence of the presence or absence of grouting reinforcement,and parameters such as longitudinal spacing and burial depth of pipe jacking on the variation trend and distribution law of building settlement was analyzed.The theoretically predicted values,numerical simulation values,and on-site …

Bridge Damage Detection And Bim Localization Methods Based On Image Recognition, Li Yu, Guo Hongjun

Journal of China & Foreign Highway

To overcome insufficient information of 2D detection data in traditional bridge maintenance,which hinders precise decision-making,this study proposed an automated method based on deep learning and structure from motion (SfM ) technology,which realized the complete process from image recognition to the accurate mapping of damage information in a building information model (BIM ).First,the YOLOv 8 deep learning model was used to automatically detect bridge surface damage.Second,the SfM technology was applied for the local 3D reconstruction of the damage area and to determine the 3D coordinates of the damage.Then,the least squares method was used to align the local coordinate system with the …

Bending Capacity And Strengthening Design With Bonding Steel Plates Of Concrete Sections In French Standards, Wu Zi

Journal of China & Foreign Highway

In the French general technical clauses widely used in Francophone African countries,only the calculation principles for the bending capacity of normal concrete sections are provided,with explicit formulas not listed,and the strengthening design of structures is not involved.According to the fundamental principles of concrete structures and French standard regulations,the calculation formulas for the bending capacity of normal concrete sections were derived.On the basis of the assumptions of strengthening design,calculation formulas for strengthening with bonding steel plates were derived.Through practical engineering calculations conducted on the VDN Expressway project in Senegal,the applicability and reliability of the proposed formulas were verified.This study can offer …

Quantitative Evaluation Of Tunnel Rock Mass Integrity Based On Mwd Technology, Zhang Kunmu, Peng Hao, Liang Ming, Han Yu, Song Guanxian

Journal of China & Foreign Highway

In tunnel construction,the quantitative evaluation of rock mass integrity heavily relies on information from the exposed face,and there are challenges when drilling data is used for integrity evaluation.To this end,this study introduced a novel method for quantitative evaluation of rock mass integrity during drilling,integrating numerical statistics with machine learning.A substantial dataset of digital drilling data was collected,covering three common types of rock mass integrity:relatively intact,relatively fractured,and fractured.Subsequently,a high-performance random forest model for the classification of rock mass integrity was developed through data preprocessing and hyperparameter optimization.The interpretability of the model ’s predictive results was enhanced using Shapley additive explanations (SHAP …

Object Detection And Tracking Based On Fusion Of Radar And Camera On Highway Side, Zeng Yongqiang, Zhang Yonghua, Zhao Hui, Liu Xin, Xu Mingsheng, Shen Jianwei, Hu Zhiwei, Chen Zhenquan

Journal of China & Foreign Highway

Camera is the most widely used sensor in intelligent transportation systems (ITS),but the decline of detection and positioning accuracy caused by target occlusion and external environment interference has always been an important factor restricting the development of ITS.In order to solve this problem,a multi-mode fusion target detection and tracking method based on millimeter-wave radar (MWR ) and camera on highway side was designed.Compared with cameras,high-resolution MWR had better measurement accuracy and weather robustness,serving as a better complement to camera perception.The proposed method used the center point-based radar and camera fusion algorithm for target detection and adopted the greedy algorithm for …

Optimized Beamforming And Network Slicing For Dense Urban 5g Deployments, Kwame S. Ibwe

Tanzania Journal of Science

Optimizing beamforming and network slicing is critical for enhancing spectral efficiency, energy efficiency, and resource distribution fairness in dense urban 5G networks. This paper proposes a hybrid genetic algorithm particle swarm optimization (GA-PSO) method to jointly optimize beamforming weights, bandwidth allocation, and power distribution, balancing computational efficiency with near optimal performance. The hybrid approach uses GA for global exploration and PSO for fast convergence, overcoming the limitations of standalone heuristic and exact optimization methods. Simulation experiments in a dense urban 5G network with massive MIMO base stations show that proposed method achieves up to 15% higher spectral efficiency and 18% …

Implementation Of A Carbon-Neutral Pv+Bess System - A Case Study Of Knauf Gypsum Tanzania, Santos Kihwele

Tanzania Journal of Science

This study presents a decarbonization pathway for Tanzania’s industrial sector by integrating a 2.966 MWp solar photovoltaic (PV) system with a 2 MW/8 MWh battery energy storage system (BESS) at KNAUF Gypsum Tanzania. A comprehensive techno- economic analysis was conducted using PVSyst simulations software. The simulation integrated site-specific meteorological data, component specifications and the factory’s electricity load profile to model annual generation patterns, system losses and battery charging and discharging cycles. The model accounted for system degradation to ensure realistic long-term performance projections. The PV+BESS solution reduces the energy-related carbon footprint to 64% and cuts annual energy costs by 65%, …

Aquifer Distribution In Lukobe Ward, Morogoro Municipality, Tanzania: Mapped Resources For Sustainable Water Access, Kelvin K. Kayuni

Tanzania Journal of Science

In response to the ongoing challenges posed by the scarcity of reliable fresh-water sources in Lukobe Ward, Morogoro Municipality, Tanzania, this study applied an integrated approach that combines geospatial and geophysical datasets to identify previously undocumented aquifers. The datasets utilized include an apparent density map generated from high-resolution GGMPlus satellite gravity data, a geological map (Quarter Degree Sheet 183), a water drainage map, and a slope map created from a digital elevation model (DEM). The analysis successfully identified four unconfined, saprolitic aquifers in the study area, designated as aquifers A, B, C, and D. These aquifers span areas of 12.2 …

Synergistic Use Of Sentinel-1 And Sentinel-2 Data For Mapping Of Degradation In Coastal Forests And Miombo Woodlands Of Tanzania, Daria C. Kimaro

Tanzania Journal of Science

Forest degradation is one of the leading sources of carbon emission globally. In Africa, particularly in Tanzania, forest degradation is driven by selective logging and forest fires. Monitoring degradation over large areas is very challenging due to the lack of accurate and reliable methods. This study assessed degradation in miombo woodlands and coastal forests using a synergy of remotely sensed data acquired from sentinel-1 and sentinel-2 achieved by integrating their complementary strength where sentinel-1 enhanced detection of structural changes and sentinel-2 provided spectral insight into vegetation. The 3I3D, unsupervised algorithm analysing trends for three vegetation indices (3I) in a three-dimensional …

Performance Comparison Of Kriging Models Used For Estimation Of Rainfall Variability In The Northern Coast Of Tanzania, Salma Suleiman, Clement Mromba

Tanzania Journal of Science

Accurate rainfall estimation underpins effective disaster preparedness and sustainable socioeconomic planning. The performance of Ordinary Kriging (OK), Universal Kriging (UK), and Simple Kriging (SK) in estimation of rainfall variability were assessed across eight stations in the northern coast of Tanzania for the period from 1960 to 2020. Using ArcGIS 10.3, each method was evaluated and cross-validated using six performance metrics, namely; Mean Error (ME), Mean Square Error (MSE), Root Mean Square Error (RMSE), Root Mean Standardized Square Error (RMSSE), Average Standardized Error (ASE), and the Coefficient of Determination (R²). Performance comparison results indicate OK to have achieved the lowest bias, …

Mathematical Modeling Of Awareness-Driven Interventions For Gender-Based Violence Control In A Closed Population, Furaha M. Chuma, Edward K. Ngailo, Zubeda S. Mussa

Tanzania Journal of Science

Gender-based violence (GBV) remains a critical global health issue with profound social, economic, and psychological implications. Despite concerted efforts to address this challenge, traditional intervention approaches often fall short of effectively mitigating its prevalence. In recent years, there has been growing recognition of the potential impact of awareness-based interventions in addressing various social and health crises. This paper introduces a modeling framework to explore the efficacy of awareness-based interventions in influencing the dynamics of the GBV epidemic within a closed population. A detailed sensitivity analysis, utilizing a normalized sensitivity index method, reveals that the violence transfer rate between perpetrators and …

Simulation Based Model For Canine Distemper Virus In Prey-Predator Dynamics, Mussa A. Stephano

Tanzania Journal of Science

This study investigates the dynamic interactions of a prey-predator ecosystem infected with Canine Distemper Virus (CDV), focusing on predation and disease transmission. A deterministic model, coupled with Monte Carlo simulations (MCS), employed to capture both stochastic variability and environmental fluctuations. The findings indicate that classical prey-predator cycles provide the baseline for population dynamics, but the introduction of CDV and environmental noise fundamentally alters system behavior. Initially, populations exhibit oscillations that gradually stabilize into dynamic equilibria. However, the disease persists within both prey and predator populations, suggesting endemicity rather than extinction. Predation plays a dual role in disease dynamics, while it …

Modelling The Impact Of Multiple Control Strategies On The Spread Of Phyllody Disease In Sesame, Augustino I. Msigwa, Furaha M. Chuma

Tanzania Journal of Science

Phyllody disease, caused by phytoplasma and transmitted by insect vectors such as leafhoppers, poses a serious threat to the productivity of sesame (Sesamum indicum) as it has caused substantial yield and oil-quality losses worldwide, with documented seed-yield reductions ranging from 38% to as high as 80% in severe outbreaks, particularly in Africa and India. Understanding phyllody dynamics is therefore critical to safeguard yields and trade. While some modeling efforts exist for sesame phyllody (for example, statistical and prediction-focused approaches), mechanistic transmission models (SEIR) assessing its full impact remain scarce. This study therefore develops and analyses impact of multiple control strategies …

Modeling And Forecasting Wholesale Gasoline Prices In Tanzania Using Arima And Neural Network Autoregressive Models, Thadei D. Sagamiko, Edward K. Ngailo

Tanzania Journal of Science

Fluctuations in wholesale gasoline prices significantly impact the economy of import-dependent countries like Tanzania, making accurate forecasting essential for policymakers and market participants. This study forecasts monthly wholesale gasoline prices in Dar es Salaam by comparing the Autoregressive Integrated Moving Average (ARIMA) model with a Neural Network Autoregressive (NNAR) model. Using data from January 2015 to December 2024 from the Energy and Water Utilities Regulatory Authority (EWURA), the models were evaluated. The ARIMA(1,1,1) model was identified as the best-fitting linear model, but the NNAR(11,7) model demonstrated superior accuracy. On the holdout test set, the NNAR model achieved a lower Mean …

Variations In Physicochemical Properties, Microbiological Profiles, And Nutrient Dynamics In The Temi River, Arusha, Tanzania: Sources And Implications, Aldo J. Kitalika

Tanzania Journal of Science

This study thoroughly investigates the physicochemical properties, microbiological profiles, and nutrient dynamics of the Temi River in Tanzania. The sources and implications of fluctuations in dissolved organic carbon (DOC) and nutrients during the wet and dry seasons are carefully analysed. Water samples were collected from various geographically referenced points along the river, and analyses were performed using the APHA Standard Methods for Water and Wastewater Testing. The results show that most parameters increased downstream in both seasons, with the highest DOC levels reaching 352.11 mg/L in the wet season, followed by a significant decrease to 126.00 mg/L during the dry …

Adaptive Generation In Evolutionary Robotics: From Adversarial Objects To Guided Optimization, Unknown Akshay

Dissertations - ALL

Evolution-inspired algorithms have proven effective for complex optimization problems butsuffer from computational inefficiency due to their reliance on random variation operators. This is problematic in domains where fitness evaluation depends on expensive procedures such as training a neural network or running a robot, either in simulation or on hardware. This dissertation presents novel approaches for evolutionary robotics that replace stochastic evolutionary operations with learned, adaptive strategies using reinforcement learning (RL), significantly improving search efficiency while maintaining population diversity.The first contribution is a voxel-based evolutionary framework for generating adversarial objects that challenge robotic grasping systems. By evolving objects with controlled similarity …

Computationally Efficient Methods For Calculation Of Light-Matter Interaction In Large Semiconductor Quantum Dots, Chandler Martin

Dissertations - ALL

Quantum dots are a class of materials in the nanometer scale that have unique optical and electronic properties due to the quantum confinement effect. Traditional electronic structure computational techniques used for calculating these properties fall to scalability issues as the size of the quantum dot increases, or introduce significant errors into the final result. This makes using computational methods to predict new materials, or verify properties of existing materials, challenging to use for experimental applications of quantum dots. This gap between experiment and computation is due to large basis sets, expensive integrals, and storage and manipulation of tensors that grow …

Geographic And Sociodemographic Disparities In Early Hearing Detection And Intervention Adherence, Amanda Pavan, Anton Kvit, Michael Van Skiba, Analise Ristic, Kirsten R. Coverstone

Journal of Early Hearing Detection and Intervention

Early identification and intervention are crucial to minimizing impacts of congenital hearing loss. Early Hearing Detection and Intervention (EHDI) programs recommend newborn hearing screening before one month of age and a diagnostic audiologic evaluation before three months for infants who do not pass the screening. However, not all infants meet these benchmarks, as geographic and sociodemographic factors may influence adherence.

Addresses of primary contacts and audiology clinics were geocoded to calculate drive times to the nearest clinic in 10-minute intervals for infants born in Minnesota between 2019 and 2021. Birth location, NICU admittance, and sociodemographic characteristics were also analyzed. Random …

Enzyme-Free Colorimetric Sensing Of Glucose Using Silver Nanoparticles With A Green Stabilizing Agent From Capsicum Chinense Jacq Extract, Boyfannie Ivan Putra, Hermin Sulistyarti, Muhammad Mashuri Utama, Aura Ananda Haryanto, Rurini Retnowati, Mohamad Rafi, Akhmad Sabarudin

Makara Journal of Science

Diabetes mellitus (DM) is a significant global health issue characterized by abnormal glucose levels in the human body. DM diagnostics are often based on invasive sampling from blood, which poses a potential risk of infection and tissue damage. Therefore, a non-enzymatic and non-invasive method for glucose monitoring is demanded as a simple alternative to glucose detection in urine samples. In this work, enzyme-free glucose determination is based on the formation of silver nanoparticles stabilized by Capsicum chinense Jacq extract (CCJ-AgNPs). Under alkaline conditions, glucose functions as a reducing agent for silver ions, and the extract acts as a stabilizer to …

Microplastic Degradation Using Laccase Enzyme From Trametes Hirsuta: In The Silico Study, Hanzhola Gusman Riyanto, Diana Sylvia

Makara Journal of Science

Microplastics are a serious global problem that arises worldwide because of their widespread use. Exposure to microplastics can negatively affect human and environmental health. In this study, we used molecular docking methods with MOE software (version 2014.0901) to investigate the interaction between the laccase enzyme and several microplastic compounds as a preliminary study of microplastic degradation using enzymes. The Quantitative Structure Analysis Relationship (QSAR) analysis revealed that all microplastic ligands had higher Pa values than Pi, indicating that the laccase enzyme may be biologically active. The findings of the present study show that polyamide (PA) has the lowest binding energy …

Multi-Satellite Image Matching And Deep Learning Segmentation For Detection Of Daytime Sea Fog Using Gk2a Ami And Gk2b Goci-Ii, Jonggu Kang, Hiroyuki Miyazaki, Seung Hee Kim, Menas Kafatos, Daesun Kim, Jinsoo Kim, Yangwon Lee

Institute for ECHO Articles and Research

Traditionally, sea fog detection technologies have relied primarily on in situ observations. However, point-based observations suffer from limitations in extensive monitoring in marine environments due to the scarcity of observation stations and the limited nature of measurement data. Satellites effectively address these issues by covering vast areas and operating across multiple spectral channels, enabling precise detection and monitoring of sea fog. Despite the increasing adoption of deep learning in this field, achieving further improvements in accuracy and reliability necessitates the simultaneous use of multiple satellite datasets rather than relying on a single source. Therefore, this study aims to achieve higher …

Fast Dispersion-Curve Inversion Using Automatic Differentiation Gradient-Based Calculation, Theodosius Marwan Irnaka, Eddy Hartantyo

Makara Journal of Science

Surface wave inversion is a crucial technique in geophysics for subsurface imaging. However, traditional methods can be computationally intensive, especially for complex models. This study introduces automatic differentiation (AD) as an efficient alternative to finite difference (FD) methods for gradient calculation in surface wave inversion. We compare AD and FD methods using three synthetic examples of varying complexity. Our results demonstrate that AD is significantly faster, with speed improvements of 3 to 12 times over FD, depending on model complexity. Moreover, AD requires up to 3 times less memory than FD. In terms of accuracy, AD provides gradient calculations that …

Design And Modeling Of A Thin Water Falling-Film For Convection-Cloud Chambers, Grant T. Schlaff, Jesse Anderson, Brandon Kieranen, Constantine M. Megaridis, Raymond Shaw

Michigan Tech Publications

Convection–cloud chambers offer a controlled environment to study aerosol-cloud interactions. Ensuring sustained supersaturation in these chambers requires a reliable and efficient water sourcing mechanism. Maintaining saturated boundary conditions on side-walls is important in chambers with large vertical dimensions (up to 10m) aimed at achieving collisional growth of cloud droplets. This study introduces the design, modeling, and measurement of a falling-film system capable of maintaining a stable, continuously replenished water film for continuous evaporation. A distributor is tested, ensuring uniform water coverage over a panel with a range of surface treatments. These surface treatments with micron to 100micron-scale roughness allow for …