Universidad de La Salle, Bogotá
Technological University Dublin
Construction Engineering & Management, Purdue University
Missouri University of Science and Technology
Cornell University
Haestad Methods
Synergetic Effect Of Viscosity Modifying Admixtures And Polycarboxylate Ether Superplasticizer On Key Characteristics Of Thixotropic Uhpc For Bonded Bridge Deck Overlay Rehabilitation,
2024
Missouri University of Science and Technology
Synergetic Effect Of Viscosity Modifying Admixtures And Polycarboxylate Ether Superplasticizer On Key Characteristics Of Thixotropic Uhpc For Bonded Bridge Deck Overlay Rehabilitation, Le Teng, Ming Jin, Jiadi Du, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Thin bonded ultra-high-performance concrete (UHPC) overlay is an advanced technology for bridge deck rehabilitation. UHPC should be tailored to secure adequate flowability and high thixotropy to facilitate mixing and placement with a low risk of sagging of the material on sloped bridge deck surfaces. The synergetic effect between nano clay (NC) and polycarboxylate ether (PCE) superplasticizer or cellulose-based viscosity modifying admixture (VMA) and PCE on the rheological properties (yield stress, plastic viscosity, and thixotropy), cement hydration, autogenous shrinkage, compressive strength, and porosity was systematically investigated. The bond strength between conventional concrete (CC) representing existing bridge deck concrete and thixotropic UHPC …
Physical And Stochiometric Controls On Nutrient Uptake And Ecosystem Respiration In Contrasting Sites,
2024
University of New Mexico
Physical And Stochiometric Controls On Nutrient Uptake And Ecosystem Respiration In Contrasting Sites, Jancoba K. Dorley
Civil Engineering ETDs
Meteorological, hydrological, and biogeochemical processes naturally control stream ecosystems. These processes define the frequency and distribution of precipitation and the supply and demand of solutes and particles to support aquatic food chains through space and time. Studies have also found that stream ecosystems are also controlled by anthropogenic activities, which occur on a much shorter timescale. These anthropogenic activities affect stream ecosystems' structure and function from local to planetary changes to the environment. It is essential for scientists and engineers to understand the relationships between naturally occurring processes and those created by human activities for a better interpretation of stream …
Modeling And Understanding Dispute Causation In The Us Public-Private Partnership Projects,
2024
Missouri University of Science and Technology
Modeling And Understanding Dispute Causation In The Us Public-Private Partnership Projects, Mohamad Abdul Nabi, Rayan H. Assaad, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The partnership between the public and private sectors has led to a new and innovative way of delivering infrastructure projects that is referred to as public-private partnership (PPP). There are various benefits associated with PPP delivery methods including risk sharing, access to private funding, innovation, and flexibility, among others. Despite the proved benefits, contract conflicts and disputes are very common in PPP projects. While previous research studies examined the risks and the potential causes of conflicts in PPP projects, little-to-no research efforts were directed to study and model the interconnectivities between the different causes of conflicts in PPP agreements. To …
Methodology To Design Eco-Friendly Fiber-Reinforced Concrete For 3d Printing,
2024
Missouri University of Science and Technology
Methodology To Design Eco-Friendly Fiber-Reinforced Concrete For 3d Printing, Haodao Li, Alfred Addai-Nimoh, Eric Kreiger, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Greater use of locally available supplementary cementitious materials (SCM) to reduce cement content and addition of fiber reinforcement can enhance the performance of 3D printing (3DP) technology in construction. In this study, three classes of eco-friendly 3D printable fiber-reinforced mixtures were targeted, namely ultra-high-performance concrete (UHPC), high-performance concrete (HPC), and conventional concrete (CC). A step-by-step methodology was proposed to maximize the substitution rate of cement with SCM and limestone filler and optimize fiber volume for the successful development of 3D printable fiber-reinforced materials. Binder combinations were initially investigated on the paste level to determine the packing density and robustness. Selected …
Numerical And Experimental Investigation Of Negative Stiffness Beams And Honeycomb Structures,
2024
Missouri University of Science and Technology
Numerical And Experimental Investigation Of Negative Stiffness Beams And Honeycomb Structures, Yasser Darwish, Mohamed A. Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Metamaterial structures that exhibit negative stiffness (MSNS) behavior have shown the potential to be used as energy dissipation systems in different applications. Negative stiffness honeycomb structures consist of multiple pre-buckled beams that snapping through from one pre-buckled mode to another buckled mode, when subjected to transverse loads, displaying negative stiffness, and dissipating a significant portion of the input energy. This paper presents finite element models (FEMs) developed to investigate the performance of negative stiffness pre-buckled beams and honeycombs. The FEMs were validated using experimental results of single pre-buckled beams and honeycomb structures. The experimental testing of the pre-buckled beams was …
Advancing Occupational Health In Mining: Investigating Low-Cost Sensors Suitability For Improved Coal Dust Exposure Monitoring,
2024
Missouri University of Science and Technology
Advancing Occupational Health In Mining: Investigating Low-Cost Sensors Suitability For Improved Coal Dust Exposure Monitoring, Mirza Muhammad Zaid, Nana Amoah, Ashish Kakoria, Yang Wang, Guang Xu
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Exposure to coal dust in underground coal mines poses significant health risks to workers, including the development of diseases such as coal workers' pneumoconiosis and silicosis. Current available methods for monitoring coal dust exposure are expensive and time-consuming, necessitating the exploration of alternative approaches. Low-cost light scattering particulate matter sensors offer a promising solution, and its development in recent years has demonstrated some success in air quality monitoring However, its application in sensing coal particles is limited partially due to that the operating condition in a mine is different than the atmosphere. Thus, the objective of this paper is to …
Research On An Improved Cotton Cleaner Unit,
2024
Termiz State University
Research On An Improved Cotton Cleaner Unit, Muzaffar Djurayev, Sherqul Hakimov, Ilhom Abbazov, Rashid Kaldybaev
Technical science and innovation
This article analyzes the results of changes to the working parts of a cotton cleaning unit from small and large impurities. It is known that the UXK installation uses continuous cleaning technology, that is, the cotton entering the purifier is cleaned in all its cleaning sections and then transferred to another process. In these sections, pieces of cotton wool from the separated waste are regenerated in a separate drum. Existing purifier suppliers use a manually operated mechanical system to monitor its performance. These factors do not make it possible to control the cleaning process when the quality indicators of cotton …
LSU
Enhancing Bridge Resilience And Overheight Vehicle Mitigation Through Innovative Sacrificial Cushion Systems, Aly Mousaad Aly, Marc Hoffmann
Faculty Publications
Transportation departments have made significant strides in addressing the challenges posed by the increasing weights of trucks on bridges. While there is a growing awareness of overheight vehicle collisions with bridges, implementing effective countermeasures remains limited. The susceptibility of bridges to damage from such collisions is on the rise, further exacerbated by unpredictable lateral impact forces. This study employs nonlinear impact analysis to assess the response of an unprotected vehicle-girder model, yielding realistic deformation outcomes comparable to observed impacts on the US-61 bridge. Predictions for a truck traveling at 112.65 km/h indicate deformations of 0.229 m, 0.161 m, and 0.271 …
Mathematical Modeling Of Fruit Drying And System Analysis Of The Process (On The Example Of Persimmon),
2024
Tashkent State Technical University, Tashkent city, Republic of Uzbekistan
Mathematical Modeling Of Fruit Drying And System Analysis Of The Process (On The Example Of Persimmon), Gani Dadayev, Jasur Safarov, Shakhnoza Sultanova, Qobiljon Muxiddinov
Technical science and innovation
Vegetable raw materials, as an object of drying, are characterized by a large amount of water and a low content of dry substances. Vegetable raw materials have a capillary-porous structure. Food products contain both bound and free moisture at the same time. The removal of moisture from the material during drying depends on the total moisture content and the form of connection of moisture with the material. Adsorption and osmotic - bound moisture is retained at the interface of colloidal particles with the environment. Food products contain both bound and free moisture at the same time. The quantitative ratio between …
Improvement Of Convective Drying Equipment,
2024
Belarusian National Technical University, Minsk city, Republic of Belarus;
Improvement Of Convective Drying Equipment, A Ponasenko, Jasur Safarov, Shaxnoza Sultanova
Technical science and innovation
Drying of agricultural raw materials is an energy-consuming but integral process. Therefore, increasing the efficiency of drying and improving the quality indicators of dried material at minimum material and energy costs is relevant for producers of agricultural products. By present time numerous researches on improvement of constructions and processes of work of dryers providing satisfactory parameters of energy saving have been carried out. In some scientific materials it is shown that the use of generative gas and straw as fuel allows to reduce energy costs for the drying process in the fluidised bed dryer by 10-30%, the quality of seeds …
Capacitive Electrode Based Moisture Measurement Converter Errors And How To Eliminate Them,
2024
Tashkent State Technical University, Tashkent city, Republic of Uzbekistan
Capacitive Electrode Based Moisture Measurement Converter Errors And How To Eliminate Them, Hamdam Jabborov, Temurbek Rashidov
Technical science and innovation
The article discusses the errors associated with the moisture measuring transducer that is based on the cylindrical electrode, along with their sources and calculation formulas for error elimination. The initial capacitance of the capacitive electrode humidity converter is dependent on its geometric parameters, such as the radii of the electrodes and their length. Accurate calculation of these geometric parameters enables the reduction of regular measurement errors in the input and switching circuit of the moisture converter to a minimum value, resulting in a significant increase in the informativeness and accuracy of the output signal. Consequently, some sources of measurement errors …
Existing Methods For Monitoring Power Autotransformers,
2024
Tashkent State Technical University, Tashkent city, Republic of Uzbekistan
Existing Methods For Monitoring Power Autotransformers, Nurali Berdiyorovich Pyrmatov, Dilafruz Rustamjon Qizi Abdullabekova
Technical science and innovation
autotransformers, methods, diagnostics, efficiency, monitoring.Particular attention is given to analyzing the gas composition of transformer oil, which is a sensitive indicator of various defects such as thermal breakdown and heating. In addition, methods based on the measurement of external magnetic field strength are discussed. This technique provides a unique opportunity to detect magnetic anomalies associated with possible defects in the structural components of the transformer. The article emphasizes that successful monitoring requires an integrated approach, combining different techniques. The authors analyze the advantages and limitations of each method and offer practical recommendations for integrating these methods into maintenance systems. In …
Influence Of Foil Stamping Parameters On Image Quality,
2024
Professor, Doctor of Technical Sciences,Tashkent Institute of Textile and Light Industry, Tashkent city, Republic of Uzbekistan;
Influence Of Foil Stamping Parameters On Image Quality, Khalima Abishevna Babakhanova, Mukhlisa Ergashevna Khasanova, Aziz Azimjonovich Soadatov, Nigora Junaydullaevna Sadriddinova
Technical science and innovation
The paper evaluates the influence of technological process parameters, namely die temperature and pressure force, on the quality of foil stamping, which is one of the types of finishing having a wide range of applications due to giving unique decorative and protective elements to printed products. When evaluating the influence of process parameters on the linearity and coverability of the image, it was found that the pressure force has less influence on the result than the temperature. According to the data of the study, it can be concluded that the maximum percentage of completeness of covering is achieved at a …
Converting Mass And Energy Balance Chemical Engineering Concepts Into Fundamentals Of Environmental Engineering (Enve 210),
2024
University of Nebraska-Lincoln
Converting Mass And Energy Balance Chemical Engineering Concepts Into Fundamentals Of Environmental Engineering (Enve 210), Kaycie Lane
UNL Faculty Course Portfolios
This evaluation of teaching examined the Fall 2023 semester of ENVE 210: Fundamentals of Environmental Engineering. The purpose of this study was to change the format of the class from a lecture-based to a flipped classroom approach through the use of pre-lectures, in-class problem sets and group work activities. In addition, this study aimed to better adapt chemical engineering textbook content related to mass and energy balances to environmental engineering by creating new environmental engineering specific and sustainable development problems. The study learning outcomes proved difficult to implement and evaluate in a hybrid distance learning class and will require future …
Sustainable Infrastructure Development In The Ikn Region (Nusantara Capital): Simulation Of The Smart Self-Sustaining Urban Center Area Development,
2024
Universitas Indonesia
Sustainable Infrastructure Development In The Ikn Region (Nusantara Capital): Simulation Of The Smart Self-Sustaining Urban Center Area Development, Naufal Budi Laksono, Yusuf Latief
Smart City
Embarking on the quest for a sustainable urban future, this research immerses itself in the vibrant landscape of "Sustainable Infrastructure Development in the IKN Region (Nusantara Capital)." This study investigates the financial viability and economic attractiveness of the Five City project, focusing on efficient infrastructure management for sustainable settlement development. The core facility comprises four vertical residential towers with supporting amenities. The research aims to evaluate the project''s feasibility over a 25-year investment period through comprehensive financial analyses.The research employs a structured approach, encompassing regulatory analysis, stakeholder identification, financial capability analysis, and risk management. Parameters such as Net Present Value …
The Interpretative Structural Modeling For Stakeholder Involvement To Reduce Slum Settlements,
2024
Universitas Indonesia, Faculty of Engineering, Civil Engineering Department
The Interpretative Structural Modeling For Stakeholder Involvement To Reduce Slum Settlements, Bich Hanes Bich, Ayomi Dita Rarasati
Smart City
The array of problems originating from slum settlements not only results in unwholesome environment, unlawful land utilization, and various internal challenges within the vicinity but also impacts the surrounding regions and the overall urban infrastructure network. In pursuit of Indonesia's 2045 Vision, which emphasizes on "equitable and integrated infrastructure development", the zero slums constitutes a pivotal component of the Ministry of Public Works and Public Housing's overarching vision. Nonetheless, a disparity has been identified in addressing slum settlements in West Kalimantan, hindering the achievement of this objective. This research aims to identify the stakeholders and the priority factors in determining …
Project Stakeholder Analysis In Temadore Bridge Construction Development,
2024
Universitas Indonesia, Faculty of Engineering, Civil Engineering Department
Project Stakeholder Analysis In Temadore Bridge Construction Development, Hud Rafsanjani, Ayomi Dita Rarasati
Smart City
The construction of bridge is important due to its ability to link communities through land-road connection, thereby saving time and increasing productivity of those living in these areas. Therefore, this research evaluated the Temadore bridge, built to link Ternate City, Maitara land and Tidore City by road to enhance movement and reduce disparities in assessing both areas. Data were collected using the Interpretative Structural Modeling (ISM) which searched for and identified several variables according to the dependence power and driving power. The result showed that construction of bridge increased the movement of community activities and productivity, thereby leading to growth.
Skilled Worker Shortage Across Key Labor-Intensive Construction Trades In Union Versus Nonunion Environments,
2024
Missouri University of Science and Technology
Skilled Worker Shortage Across Key Labor-Intensive Construction Trades In Union Versus Nonunion Environments, Tamima Elbashbishy, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Skilled labor plays a crucial role in ensuring that construction projects are completed on time, within budget, and to the required standards of quality and safety. However, the construction industry has been facing a labor shortage in recent years, which poses a significant challenge to the industry's growth and sustainability. Therefore, it is important to examine the characteristics of the construction skilled labor market to understand the factors that contribute to the shortage of skilled workers and develop strategies to address the issue. This paper fills this knowledge gap. To this end, the authors (1) collected and processed project documentation …
A Holistic Approach To Exploring The Root Factors Of Work Zone Accidents,
2024
Missouri University of Science and Technology
A Holistic Approach To Exploring The Root Factors Of Work Zone Accidents, Bahaa Chammout, Muaz O. Ahmed, Islam H. El-Adaway, William Lieser
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Work zones are crucial for infrastructure maintenance and improvement. However, ongoing projects within work zones sometimes can place workers and drivers in dangerous situations. Despite safety regulations, work zone accidents persist with notable severity and frequency. Previous research has explored work zone accident causation, but it has not provided a comprehensive understanding of the factors that impact work zone safety. This paper addresses this research gap by following a multistep methodology. First, a systematic literature review (SLR) was conducted to identify a comprehensive list of 37 factors impacting work zone safety. Second, social network analysis (SNA) was employed to analyze …
A Vehicle-Bridge Interaction Model Considering Contact Patch Size And Vehicle Self-Generated Excitation – A Theoretical Study,
2024
Missouri University of Science and Technology
A Vehicle-Bridge Interaction Model Considering Contact Patch Size And Vehicle Self-Generated Excitation – A Theoretical Study, Zhenhua Shi, Yahya M. Mohammed, Nasim Uddin, Genda Chen
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This paper presents an improved theoretical damped single-axle vehicle-bridge dynamic interaction model to consider the effect of the contact patch size and motor-induced vehicle excitation. The contact patch issue is critical as it determines the minimum time step for simulation and maximum identifiable frequency, while the inclusion of the motor-induced vehicle excitation benefits the design of autonomous self-driven rather than towed vehicles. Estimations of the contact patch size for both the pneumatic tire and solid wheel scenarios are discussed. The contact patch responses, which degenerate into contact point responses when the contact patch size is assumed to be infinitely small, …
