Engineering Commons^™

Analysis Of Shear Bearing Mechanism And Influencing Factors Of Mcl-Shaped Composite Dowel Connector, Zeng Zhuo, Zhou Baicheng, Cheng Xianjie, Cao Zhengxing, Gao Rongxiong, Wang Zichao

Journal of China & Foreign Highway

To investigate the bearing mechanism of modified clothoid (MCL)-shaped composite dowel shear connectors and the influence laws of various factors on their shear bearing capacity, the stress states and failure modes of the steel dowel, concrete dowel, and transverse through-reinforcement that constitute the MCL-shaped shear connector were deeply analyzed in this paper based on an experimentally validated finite element model. Furthermore, the influence laws of transverse through-reinforcement, steel dowel thickness, and concrete strength on the shear bearing capacity of the MCL-shaped composite dowel were explored. The research results indicate that the bearing process of the MCL-shaped composite dowel exhibits elastic, …

Research On Improving Bearing Capacity Of Full-Scale Prestressed Concrete Small Box Girders, Huang Jianyun, Gao Linli, Liu Zufeng, Ma Jinku, Ma Ming, Wang Xiaoguang

Journal of China & Foreign Highway

To solve the problems of lacking comparative research on the improvement effects of different reinforcement methods when formulating reinforcement schemes for prestressed concrete small box girders and that existing bearing capacity improvement tests mostly focus on scale models with insufficient reliability of results, full-scale model tests and numerical simulation analysis of five 30 m span prestressed concrete small box girders with different joint reinforcement measures were conducted in this paper. Finite element models for two single reinforcement measures were established, and the improvement effects of different reinforcement methods on the bearing capacity of prestressed concrete small box girders were studied. …

Study On Calculation Method For Incremental Launching Based On Nonlinear Analysis, Mo Shanfeng, Huang Cailiang, Qin Hui

Journal of China & Foreign Highway

In view of the shortcomings of traditional incremental launching calculation methods and the assembly construction control of incremental launching beams, an incremental launching calculation method based on nonlinear analysis was proposed in this paper. This method could truly simulate the running state where the incremental launching pier remains stationary, and the beam moves forward. The assembly alignment of all segments of the beam and the real alignment of the beam under specified working conditions could be directly output. The prefabricated alignment of the main beam (i.e., unstressed alignment) did not need to be consistent with the slide alignment. When the …

Key Construction Technologies For Single-Tower Rotating-Cable Suspension Bridges With Steel Truss Girders In Mountainous Regions, Gao Shuangjian, Zhang Weichao, Fu Lihong, Zhu Shuo

Journal of China & Foreign Highway

Given the problems of narrow construction sites, difficult construction organization, and high safety and quality risks faced in the construction of bridges in steep canyon regions of mountainous areas, this paper carried out research on key technologies for bridge construction in mountainous areas based on the Yellow River Three Gorges Bridge of the Jiyuan‒Xin’an Expressway. For the excavation of deep and large anchorage foundation pits in mountainous areas, a technical scheme of “loosening controlled blasting combined mainly with mechanical excavation and supplemented by manual excavation” was adopted. As this project is a single-tower single-span ground-anchored rotating-cable suspension bridge, the technologies …

Mix Proportion Design Of Tunnel Shotcrete Based On Diorite Manufactured Sand, Song Funing, Wang Zegang, Liu Naifei, Song Zhanping

Journal of China & Foreign Highway

Tunnel construction produces a large amount of waste slag, which cannot be effectively utilized due to various factors. By using tunnel slag to prepare manufactured sand to replace natural sand, resources can be saved; costs can be reduced, and the environment can be protected. Based on the Xi’an‒Shiyan high-speed railway project, the physical and mechanical properties of diorite along the tunnel were tested; the physical properties and concrete performance of manufactured sand and natural sand were comparatively studied, and the effects of water-binder ratio and sand ratio on the performance of shotcrete were analyzed by designing multiple sets of mix …

Surface Deep Well Dewatering Methods For Tertiary Water-Rich Semi-Diagenetic Section Of Wangjiazhai Tunnel, Liu Chengwen, Liu Gang, Xu Hua, Wei Meng

Journal of China & Foreign Highway

The tertiary semi-diagenetic sandstone of the Wangjiazhai Tunnel on the Yunnan Linqing Expressway is characterized by loose structure, low diagenetic strength, and poor cementation. The geological disasters such as collapse, water gushing, and mud bursting are very easy to happen when the tunnel passes through the water-rich section. With the surface deep well dewatering of the tertiary water-rich semi-diagenetic section of Wangjiazhai Tunnel as an example, the surface deep well dewatering methods and key parameters for tunnel crossing the tertiary water-rich semi-diagenetic section were discussed. Based on the single well surface dewatering test, the groundwater level and strata permeability of …

Ventilation Design And On-Site Effect Testing For Construction Of Multiple Working Faces In Tianshan Shengli Tunnel, Xiong Ziyi, Jia Haiyang, Suo Feiyu, Liu Weiwei, Chen Jianxun, Yang Ziyao, Wang Heqi

Journal of China & Foreign Highway

To explore the ventilation optimization and energy saving issues in the construction of multiple working faces in extra-long highway tunnels, the air volumes required for a single working face under drilling and blasting construction conditions and TBM tunneling conditions were determined respectively based on theoretical calculations. Combined with the tunnel construction organization scheme, two ventilation schemes were proposed, and they were compared and selected according to the configured power of axial fans. Based on the recommended scheme, the layout scheme of pollutant-discharging jet fans was designed, and its feasibility was finally verified by on-site measurements of pollutant concentrations. The research …

A Prediction Method For Scale Of Karst Cave Water Inrush And Mud Outburst Based On Comprehensive Advanced Geological Prediction, Yang Weilin, Xiao Huabo, Meng Lubo, Zhang Caihong, Chen Weidong, Wang Hao

Journal of China & Foreign Highway

To improve the accuracy of water inrush and mud outburst disaster prediction during tunnel construction through karst caves, a method of first forecasting the unfavorable geological conditions of karst caves and subsequently predicting water inrush and mud outburst geological disasters was proposed in this paper. First, a karst cave advanced prediction model based on the polynomial naive Bayes algorithm was established to predict the scale grade of karst caves. Secondly, taking the scale prediction results of karst caves as the input condition for water inrush and mud outburst, a support vector machine (SVM) grade prediction model for karst cave water …

Research On Recognition Of Highway Toll Vehicles Based On Dual-View Feature Fusion Network, Xiao Qiang, Chen Xinjia, Chen Jing, Zhao Bin, Yan Kaifeng, Ding Hongwei

Journal of China & Foreign Highway

To solve the practical problems in vehicle type classification on toll roads, a deep learning network based on dual-view feature fusion, named ETCLNet, was proposed in this paper. A dual-branch architecture was adopted by the network to extract the features of vehicle head and side body images, respectively, and combined with an innovatively designed multi-scale feature extraction module, namely IPFE, and an adaptive weighting-based bilinear feature fusion (AWBF) mechanism, efficient and fine-grained vehicle feature representation was achieved. Through the design of parallel multi-scale convolutions and residual connections, the problem of gradient vanishing was effectively alleviated, and the adaptability to complex …

Analysis Of Traffic Congestion Patterns In Continuous Bottleneck Construction Zones Of Highways Under Mixed Traffic Of Passenger And Freight Vehicles, Han Hailong, Song Tailong, Ma Tianyong, Fan Zhaodong, Chen Zhexin, Chen Liang

Journal of China & Foreign Highway

To investigate the traffic congestion pattern changes in continuous bottleneck sections of highway construction zones under mixed passenger and freight traffic conditions, the spatio-temporal evolution laws of vehicle speed and lane-changing trajectory distribution in construction sections with successive lane-narrowing bottlenecks were studied. Based on measured highway data, traffic flow simulation parameters were calibrated using a genetic algorithm. By taking traffic volume and the proportion of passenger and freight vehicles as entry points, a traffic simulation experiment for continuous bottleneck construction zones under multi-factor coupling effects was constructed, and the spatio-temporal variation characteristics of speed and lane-changing trajectory distribution in the …

Analysis Of Temperature Field Of Steel Box Girders During Steam Curing Construction Process Of Steel-Uhpc Composite Bridge Decks, Wu Shang, Zhang Yongjian

Journal of China & Foreign Highway

To clarify the influence of high-temperature steam curing of steel-ultra-high performance concrete (UHPC) lightweight composite bridge deck paving on the temperature field of the steel box girder, taking a certain bridge in Hunan Province as an example, finite element numerical simulation and actual bridge testing were conducted on the temperature field of the steel box girder during the high-temperature steam curing process of the bridge deck paving. The numerical calculations were generally consistent with the test results. The analysis results indicate that under the superimposed effect of solar radiation heating and high-temperature steam curing heating, the maximum temperature of the …

Summary And Prospect Of Typical Diseases In Energy Transport Channels In Winter Cold Regions Over Past 20 Years, Jia Qinlong, Hou Zhongfei, Yin Yanping

Journal of China & Foreign Highway

To investigate the typical disease characteristics of energy transport channels in winter cold regions and guide the design for extending road service life, the causes of diseases such as pavement reflective cracks, continuous potholes on bridge decks, and failures of bridge drainage systems were analyzed based on the 20-year operation data of a 531 km in-service expressway in the coal energy region of northern Shaanxi. The research results indicate that when the asphalt pavement thickness reaches 22 cm, the reflective crack spacing of the expressway operated for 15 years can be controlled to over 50 m. Basically, no base layer …

Road Design Methods For Brt Projects Based On French Standard System : A Case Study Of A Project In West Africa, Wang Meng, Wu Cheng

Journal of China & Foreign Highway

With the continuous advancement of China ’s “Belt and Road Initiative”, Chinese enterprises have become increasingly involved in international engineering markets, undertaking numerous transportation infrastructure projects, particularly in Africa and Southeast Asia. However, international engineering projects commonly face the challenge of inconsistent design standard systems across different countries, posing significant difficulties for Chinese enterprises during project implementation. To address this issue, the differences in BRT road design under Chinese and French standards were focused on in this study, and their respective design philosophies and methods were analyzed. Taking a BRT project in a West African country as an example, field …

Compact Low-Profile Dual-Band Microstrip-Fed Monopole Antenna For Wlan And Lte Applications, Hashimu U. Iddi

Tanzania Journal of Engineering and Technology (TJET)

The rapid advancement in wireless communication technologies has led to rising user demand for high-speed data transfer, seamless connectivity, and improved wireless communication efficiency. Therefore, it is inevitable to develop efficient and compact antennas which can support different frequency bands of various wireless system standards in mobile devices. A compact, low-profile microstrip-fed monopole antenna operating in dual bands, 2.45 GHz and 5.8 GHz, and suitable for WLAN and LTE applications is proposed in this study. The proposed antenna’s radiating element was carefully designed using slotting techniques and optimising the various parameters for achieving the required resonance frequency. The proposed compact, …

Trajectory-Based Model Predictive Control For Rotary Crane Sway Suppression With Only Horizontal Boom Actuation, Haryson J. Nyobuya

Tanzania Journal of Engineering and Technology (TJET)

Safety is of biggest importance in construction and industrial activities involving rotary cranes. These cranes are huge and responsible of moving large parts or/and materials from different positions. Now operating these cranes tend to be subdue to pay load oscillations when moving the load for which is extremely dangerous when not suppressed. This study proposes the generation of trajectory using Model predictive control approach with reduced control horizon compared to state horizon. Reduced control horizon design reduces computational time for trajectory generation while maintaining the pay-load sways to a minimum. In this approach the complex dynamic model is reduced to …

On The Use Of Lorawan For Smart Fishing Applications In The Blue Economy Sector, Eva Shayo

Tanzania Journal of Engineering and Technology (TJET)

The growth of digital technology is expected to transform small-scale fishery sectors, where a need for robust, low-cost, long-range communication networks becomes critical. There exist several technologies that are used in the fishery sector but they are never affordable to small scale fisheries. This study evaluates the feasibility of using low cost Long Range Wide Area Network (LoRaWAN) technology specifically tailored for smart fishing environments to small scale fishery sector. Using simulation, we assess the performance of the key performance metrics including probability of success and energy efficiency under varying device densities and time. During evaluation, we considered end devices …

Optimal Design And Techno-Economic And Environmental Analysis Of A Hybrid Solar Pv-Battery-Generator System For Off-Grid Telecom Towers And Rural Households: Case Of Misughaa Village In Tanzania, Ibrahim Mwammenywa, Martha Mwaikenda

Tanzania Journal of Engineering and Technology (TJET)

Telecommunication services are pivotal for the socio-economic development of communities, regions, and countries. Extensive and reliable telecom infrastructure enables populations to leverage development opportunities and bridge the urban-rural divide. However, extending these services to rural areas often necessitates the deployment of telecommunication towers in locations lacking national grid access. Consequently, service providers typically rely on diesel generators (DG) for power, which introduces significant challenges. These challenges include a high operational expenditure (OPEX), rendering telecom services unaffordable for rural communities, and substantial environmental pollution from greenhouse gas (GHG) emissions. This study aims to present an optimal design, encompassing sizing and economic …

Physicochemical Properties And Chemical Compositions Of Cashew Nut Shell Liquid Extracted With Carbon Dioxide–Expanded Hexane, Neema Msuya, Joseph Yn Philip, Frank Jacob, Kando K. Janga

Tanzania Journal of Engineering and Technology (TJET)

Cashew nut shell liquid (CNSL) is a mixture of phenolic compounds that can effectively replace commercially available phenols in various applications. This study investigated the physicochemical properties and chemical composition of CNSL extracted using CO₂–expanded hexane (CXH) and compared to the traditional Soxhlet extraction method. Steamed cashew nut shells (sCNS) were used in both cases.  The CXH was carried under varying CO₂-mole fractions (0.468-0.892) and temperatures (20-36 °C) whereas Soxhlet extraction was performed at atmospheric pressure and hexane boiling point. Response Surface Methodology (RSM) with Central Composite Face-Centred Design (CCFD) was employed to evaluate the effect …

Voltage Profile Enhancement In Iliceto Shield Wire Scheme For Rural Electrification: Case Study Of Chalinze-Mbwewe Transmission Line In Tanzania, Ebeneza Chaula, Ibrahim Mwammenywa, Santos Kihwele

Tanzania Journal of Engineering and Technology (TJET)

Rural electrification faces challenges due to significant voltage drops over long transmission distances, affecting reliability and power quality. While the Iliceto Shield Wire Scheme (ISWS) offers a modern cost-effective solution, voltage stability remains a challenge. This study analyses voltage profile enhancement within ISWS, focusing on the Chalinze-Mbwewe section of the 132 kV transmission line, using LTSpice simulations. Due to LTSpice limitations, direct solar PV integration was mimicked by introducing a secondary voltage source at each load centre, producing 33 kV to match the original source voltage. This approach maintained improved voltage profile from Msoga Village to Mbwewe over 80.9 Kilometers. …

The Impact Of Gender Sensitization On Requirements Elicitation: A Controlled Experiment, Ruthbertha Kateule, Salome Maro, Leonard Peter Binamungu

Tanzania Journal of Engineering and Technology (TJET)

Previous studies in software engineering have reported the importance of considering gender aspects in various software engineering activities, including requirements engineering, however, to the best of our knowledge, no work has investigated the impact of gender sensitisation on eliciting gender inclusive software requirements. The objective of this study was to understand the impact of gender sensitisation on software requirements elicitation. We conducted a controlled experiment using 40 undergraduate students from three different computing programs at the University of Dar es Salaam. The 40 participants were divided into 9 groups with both males and females. The participants were asked to elicit …

Enhancing Community Engagement Through ‘Nitunze Kilombero’ Mobile App: Case Of Climate Land Use And Cover Management For Kilombero Basin, Ghanima Chanzi, Subira Munishi

Tanzania Journal of Engineering and Technology (TJET)

The Kilombero Basin in southeastern Tanzania faces significant challenges due to rapid land use and land cover (LULC) changes driven by climate change, population growth, and unsustainable farming practices. This study assessed the role of community engagement and digital reporting through the 'NITUNZE KILOMBERO', mobile application in supporting water resources management in the basin. The App facilitates real-time reporting of environmental issues, provides educational resources, and enables collaboration between local communities and authorities. A mixed-methods approach, including household surveys and key informant interviews, was employed to assess the app's effectiveness. Results indicate high community awareness of LULC impacts, with 85% …

Load Flow And Fault Performance Evaluation Of Interconnected Minigrids In Uganda Using Digsilent Powerfactory, Prossy Mutesi, Santos Kihwele, Emmanuel Matee

Tanzania Journal of Engineering and Technology (TJET)

The increasing demand for decentralized, reliable electricity in rural Sub-Saharan Africa has catalyzed the deployment of minigrids as an intermediate electrification strategy. This study investigates two solar photovoltaic (PV) mini-grids: Kyamugarura and Kanyegaramire, located in western Uganda, approximately 3km apart. Each mini grid initially consisted of 13 kW installed photovoltaic (PV) capacity, supplying power to households and small businesses. Due to rising demand and regular evening blackouts, both mini-grids are being upgraded to 57 kWp each. The integration of these upgraded systems into the national utility grid is proposed and simulated to evaluate performance improvements under two medium-voltage interconnection options: …

Characteristics And Microscopic Mechanisms Of Nsep-Modified Asphalt With Reduced Fume Emission And Enhanced Environmental Benefits, Yiliang Li, Jianguo Wei, Anmin Zou, Jinming Li, Jenny Liu, Di Wang, Xuan Xiao, Yuming Zhou

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Toxic fumes emitted during the construction and maintenance of hot-mix asphalt mixtures represent a significant challenge for both the environment and construction workers. To reduce the generation of these toxic fumes, nano-sepiolite (NSEP, a natural mineral) powder was incorporated into base asphalt (BA), styrene-butadiene-styrene (SBS) -modified asphalt (SBSA), and crumb rubber-modified asphalt (CRA) to formulate sepiolite-modified asphalt binders. The rheological properties of these NSEP-modified asphalts were evaluated using dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests. Subsequently, smoke density tests and gas chromatography-mass spectrometry (GC-MS) were utilized to analyze the quantity and composition of the volatile organic compounds …

(R2142) Queueing System With Batched Services, Server-Controlled Re-Service, Set-Up Time And Multiple Vacation, S. Karpagam, N. Aarthy, B. Somasundaram

Applications and Applied Mathematics: An International Journal (AAM)

To analyze a bulk queueing system with server-controlled admission for reservice, low-batch service, multiple vacation and set-up time. The study explores how the server dynamically adjusts between low-batch and bulk services based on the queue size. After completing a bulk service, the departing batch may request reservice with a certain probability. However, accepting the request is not mandatory, and the server admits it with some probability. Whenever the queue becomes empty, whether after reservicing, completing service with no reservice request, or ending the low-batch service, the server enters a random-length vacation. If the queue still has less than ‘a’ customers …

(R2140) Verifying The Proper Efficiency In Multi-Objective Problems, Javad Bavali, Hadi Basirzadeh

Applications and Applied Mathematics: An International Journal (AAM)

Over the past decade, numerous approaches have been put forward to address multi-objective optimization problems-focusing on approximating proper efficient solutions instead of the efficient solutions. These methods are important because, according to Geoffrion’s conjecture, proper non-dominated solutions constitute a dense subset of the non-dominated solution set. In the current study, first, using the definition of Kuhn-Tucker’s proper efficiency, we present a linear subproblem that investigates the proper efficiency of a randomly selected feasible point. Additionally, the relationship between the different types of solutions to this sub-problem and the proper efficient solutions of the main problem has been analyzed. Next, we …

(R2187) Analysis Of Neurological Impairments In Hospitalized Patients Using Cubic Neutrosophic Sets, B. Anitha, M. Lavanya

Applications and Applied Mathematics: An International Journal (AAM)

This study introduces an MCDM-based framework for identifying neurological diseases in hospitalized patients using symptom-based evaluations. A team of interns, guided by the chief doctor, was responsible for determining each patient’s precise condition from the presented neurological symptoms. To enhance diagnostic accuracy, the interns employed the TOPSIS and WASPAS methods to assess and rank the potential disease options. The combined analysis yielded a clear identification of the highest ranked disease for every patient, highlighting the effectiveness of these MCDM techniques in supporting clinical decision making.

Investigation Of Inlet Turbulence Effects On Mixing Characteristics Of A Jet In Crossflow, Erin Jagger

Masters Theses

Gas flaring is widely used in the oil and gas industry to dispose of excess waste gas, and improving flare efficiency is critical for reducing emissions. Flare performance depends strongly on turbulent mixing between the flare gas and surrounding crossflow. While previous studies have examined the effects of crossflow velocity and low turbulence levels, the combined effects of crossflow turbulence intensity and integral length scale on mixing remains insufficiently understood.

This study uses a non-reacting jet in crossflow (JICF) configuration to represent the mixing process between the flare and crossflow interaction. Using computational fluid dynamics (CFD), Reynolds-Averaged Navier-Stokes (RANS) simulations …

Bio-Inspired Visual Intelligence: Improving Efficiency And Robustness Through Foveal-Peripheral Sampling And Learned Saccades, Jiayang Liu

Dissertations - ALL

Deep neural networks have achieved state-of-the-art performance across a wide range of computer vision tasks, yet their deployment in real-world and safety-critical domains remains limited by two major challenges: vulnerability to adversarial perturbations and high computational cost. While adversarial training can improve robustness under certain threat models, it is computationally expensive and often generalizes poorly to black-box or transferable attacks. At the same time, conventional vision pipelines process uniformly sampled high-resolution images, introducing substantial data redundancy, latency, and energy overhead. In contrast, the human visual system achieves efficient and robust perception through space-variant foveal-peripheral sampling, attention-guided saccadic eye movements, and …

Agentic Ai-Enabled Physics-Informed Machine Learning Framework For Intelligent Building Modeling, Control, And Automation, Zixin Jiang

Dissertations - ALL

Buildings account for a significant share of global energy consumption, and meeting the 2050 net-zero decarbonization targets requires retrofitting approximately 10,000 buildings per day in the United States alone. However, current human-centered workflows for building modeling, simulation, control, and operation remain too slow and labor-intensive to support deployment at this scale. This dissertation proposes an integrated two-pillar framework consisting of a physics-informed machine learning framework for integrated building modeling, control, and simulation, and a multi-agent agentic AI framework for automating building energy engineering workflows built on top of that foundation. The first pillar introduces a Physics-Informed Modularized Neural Network (PI-ModNN) …

Rapid Synthesis And Processing Of High-Capacity Layered Oxide Cathode Materials For Lithium And Sodium Batteries, Hansheng Li

Dissertations - ALL

Lithium-Manganese-Rich-Oxide (LMRO) is a type of layered oxide cathode active material with high energy densities of up to 900 - 1,000 Wh kg-1, competitive in capacity-demanding rechargeable lithium batteries. The increased energy density is beneficial for the range and recharging interval of electric vehicles. Based on layered Ni/Mn/Co oxide cathode materials, a high Mn content is chosen for this project as being abundant, while increased Ni concentration trades off thermal stability with specific capacity, while Co is carcinogenic and sourced less sustainably. Lithium content is increased along with Manganese content stoichiometrically as a second phase is introduced. Traditional synthesis routes …