Engineering Commons^™

4d Printing Of Smart Hydrogel Scaffold To Program Neural Stem Cell Differentiation, Omar Khater

USF Tampa Graduate Theses and Dissertations

Injuries like Traumatic brain injuries (TBI) and Spinal cord injuries (CSI) areconsidered one of the biggest challenges in the medical sector as there is no specific treatment for these injuries and the medical intervention on these injuries is restricted to reducing the pain and removing the damaged human parts. One of the helpful and most effective treatment methods for these injuries involve neural tissue regeneration in the area of the injury. The main issue when trying to treat such injuries is that neural tissues are often unable to regenerate by themselves and require outer human intervention to differentiate. Biomedical scaffolds …

Design And Simulation Of Ts Fuzzy Based Cooperative Control Of Missile Formation, Yexin Zhang, Yu Cheng, Hongyan Yan, Xuwei Fan, Xu Zhang, Yi Tian

Journal of System Simulation

Abstract: Aiming at the requirement of cooperative operation of multi-missile formation, a cooperative control algorithm of multi-missile formation based on Takagi-Sugeno(TS) fuzzy control theory is proposed.The flight speed, trajectory angle and trajectory deflection angle of the missile are taken as parameters in the leader-follower mode missile formation flying system.The local asymptotically stable controller is designed by using the systemlocal linearization of multiple groups of equilibrium pointsduring the whole flight process.Through the expert experience method,the membership function and fuzzy rules for the system are designedwith TS fuzzy theory, and the whole multi-missile cooperative control system is completed and the stability …

Synthesis And Consolidation Of The Aluminosilicate Mineral Anorthite, Lauren E. Eccles

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Solid-state ceramic synthesis is a fabrication process involving high temperature reactions of solid component powders and is used to prepare materials with novel and advanced properties. Regarding synthetic mineral ceramics, the solid-state process makes it possible to design synthetic minerals with specific compositions and properties not commonly found in their natural, comparatively impure, counterparts. This study focuses on the synthesis of the feldspar anorthite, CaAl₂Si₂O₈, via solid-state procedures and the densification of the synthesized powders using the technique of uniaxial hot-pressing. Constituent powders of aluminum sesquioxide (Al₂O₃), silicon dioxide (SiO …

Towards Emulation Of Intelligent Iot Networks On Eu-Us Testbeds, Sachin Sharma, Saish Urumkar, Gianluca Fontanesi, Venkat Sai Suman Lamba Karanam, Boyang Hu, Byrav Ramamurthy, Avishek Nag

Conference papers

This paper introduces our project on experimental validation of intelligent Internet of Things (IoT) networks. The project is a part of the NGIAtlantic H2020 third open call to perform experiments on EU and US wireless testbeds. The project proposes five different experiments to be performed on EU/US testbeds: (1) automatic configuration/discovery of Software Defined Networking (SDN) in wireless IoT sensor networks, (2) Machine Learning (ML) assisted control and data traffic path discovery experiments, (3) GPU and Hadoop cluster assisted experiments for ML algorithms, (4) Inter-testbed experiments, and (5) Failure recovery intercity experiments. Further, initial experimentation on EU/US testbeds is explored …

Selecting And Optimizing Origami-Based Patterns For Deployable Space Systems, Diana Stefania Bolanos

Theses and Dissertations

This thesis addresses the design difficulties encountered when designing deployable origami-based arrays. Specific considerations regarding thickness accommodation, deployment, and parameter modifications are discussed. Patterns such as the Miura-ori, flasher, and hexagon are investigated, with emphasis placed on pattern modification from zero-thickness to finite-thickness. Applying origami principles to form engineering solutions is a complicated task. Competing requirements may create confusion around which pattern is most favorable for the space array application. Implementing origami into a finite-thickness, engineered system poses challenges that are not manifest in a zero-thickness model. As such, it is important to understand and address the limitations of the …

Modeling And Analysing The Impact Of Heat Pump Water Heaters On Distribution Systems Using Gridlab-D, Midrar Adham

Dissertations and Theses

With the constant increase in energy demand, finding ways to reduce peak load and the energy-costs factors has become more imperative. Domestic water heating showcases a significant opportunity for such applications. Water heating is the second-highest energy consumer in the residential sector across the United States. Electric Water Heaters (EWHs), in particular, constitute nearly 43% of American household water heating energy consumption. Heat Pump Water Heater (HPWH), on the other hand, is an advanced water heating technology that has recently emerged in the United States residential market.

The objectives of this work are to develop a HPWH model and build …

Load-Adjusted Prediction For Proactive Resource Management And Video Server Demand Profiling, Obinna Izima, Ruairí De Fréin

Articles

To lower costs associated with providing cloud resources, a network manager would like to estimate how busy the servers will be in the near future. This is a necessary input in deciding whether to scale up or down computing requirements. We formulate the problem of estimating cloud computational requirements as an integrated framework comprising of a learning and an action stage. In the learning stage, we use Machine Learning (ML) models to predict the video Quality of Delivery (QoD) metric for cloud-hosted servers and use the knowledge gained from the process to make resource management decisions during the action stage. …

The Effects Of Curing Temperature On The Hydration Kinetics Of Plain And Fly Ash Pastes And Compressive Strength Of Corresponding Mortars With And Without Nano-Tio2 Addition., Dan Huang, Mirian Velay-Lizancos, Jan Olek

International Conference on Durability of Concrete Structures

Incorporation of fly ash in cementitious systems containing ordinary portland cement (OPC) increases their long-term strength and durability. However, replacement of cement by fly ash also reduces the heat of hydration of such systems and reduces early-age strength development. The reduced rate of strength development can increase the risk of durability problems, e.g. scaling, in cases when young concrete is exposed to low temperatures and deicing chemicals. This study investigated the potential of nano-titanium dioxide (nano-TiO₂) particles to modify the hydration kinetics of fly ash pastes and compressive strength development of corresponding mortars cured under low (4°C) and …

The Degradation Of Concrete Tunnel Wall Panels: A Case Study, Christian Paglia

International Conference on Durability of Concrete Structures

Concrete panels are often used along tunnel walls for technical and aesthetic purposes. Generally, the environment in contact with such materials is aggressive. Emission gases from the vehicles, sulphates, chlorides coming from the winter salt spreading, high temperature and humidity promote an acceleration of the deterioration phenomena. In this work 30 years old concrete panels placed along a 16 km long highway tunnel across the Alps were investigated with respect to their durability. The focus was given to the tunnel entrance zone. This region of the tunnel exhibited a critical environment with respect to the durability of the cementitious material …

End Effect Of Corroded Steel Bar In Concrete Specimen During Corrosion Test By Galvanostatic Method, Peng Zhao, Gang Xu, Qing Wang, Xuan Wang

International Conference on Durability of Concrete Structures

The galvanostatic method is a commonly used accelerated corrosion method in studying the durability of concrete structures caused by steel corrosion. If this method is not adequately controlled, the ends of steel bars will be corroded seriously (this phenomenon is called end effect), which is not common in natural corrosion. How to effectively control the end effect during electrified corrosion is helpful to make the characteristics of electrified corrosion more similar to that of natural corrosion. In this paper, experimental and electromagnetic numerical simulation methods are used to study the influence of cathode and corrosion medium coverage area along the …

Investigation Of Chloride Transportation Mechanism In Reinforced Concrete Specimen Subjected To Eccentric Compression, Yong Dong Yan

International Conference on Durability of Concrete Structures

In order to deal with the chloride ion transportation mechanism in eccentric compressive concrete pier and column in marine environment, stress distribution in the section of eccentric compressive concrete specimen was analyzed firstly, relationship between chloride diffusion coefficient and stress level was developed according to porosity varying under different loads, at last a model of chloride diffusion coefficient under varying stress level was developed. Conversion-diffusion equation in COMSOL Multiphysics was used in this paper to calculate the chloride ion transportation process. Three test beams with different mixture were cast and then loaded to different stress level. After that, all of …

Finite Element Modeling Of Thermal Effect On Airport Slabs, Chuanyue Shen

International Conference on Durability of Concrete Structures

A sub-ground tunnel connecting two concourses of a terminal at Chicago O’Hare International Airport suffered from water leakage. The airport engineers suspected that the problem was caused by high stresses impinging on the tunnel structure by the pavement sections above the tunnel, acting to damage joints and waterproofing membranes that should have prevented such leakage. To provide a fundamental solution to this problem while minimizing the interference with airport operation, a repair strategy needs to be determined based on a clear understanding of the root cause. A preliminary field inspection confirmed that the concrete pavement slabs moved significantly when ambient …

Application Of Multi-Environmental Time Similarity Theory Based On Relative Information (Ri-Mets) Theory In Durability Of Concrete Structures In Marine Chloride Environment, Zhang Kai

International Conference on Durability of Concrete Structures

The Multi-environmental time similarity (METS) method is a testing method that establishes the similarity relationship between the indoor test environment and the on-site environment to evaluate the durability and predict service life of the proposed or under-constructed concrete structure. Based on the METS theory, a similarity ratio of chloride ion concentration and diffusion coefficient between the indoor accelerated environment and the on-site natural environment was established. Then the relative information entropy was introduced into the Multi-Environmental Time Similarity based on Relative Information (RI-METS) theory to consider the time variability of the diffusion coefficient and the surface chloride ion mass fraction. …

Durability Assessment Of Repairing Vertical Cracks In Concrete Using Microbially Induced Calcium Carbonate Precipitation Technique, Chunhua Lu

International Conference on Durability of Concrete Structures

No abstract provided.

End Effect Of Corroded Steel Bar In Concrete Specimen During Corrosion Test By Galvanostatic Method, Peng Zhao, Gang Xu, Qing Wang, Xuan Wang

International Conference on Durability of Concrete Structures

Corrosion of steel bars is the main durability problem of concrete structures, which seriously endangers the safety and service life of reinforced concrete (RC) structures. When studying such problems, the electrifying corrosion method is often used to obtain corroded components. How to effectively control the corrosion area of steel bars is the key to improve the applicability of the corrosion method. In this paper, experimental and electromagnetic numerical simulation methods are used to study the influence of cathode and corrosion medium coverage area along the longitudinal direction on the corrosion area of steel bar before concrete protective layer corrosion cracking. …

Causes Of Cement Concrete Pavement Diseases In High-Cold And High-Altitude Areas And Progress In Repairing Techniques, Tiejun Hou

International Conference on Durability of Concrete Structures

The climatic characteristics of high-cold and high-altitude areas are low temperature, large temperature differences, and strong ultraviolet radiation. This paper analyzes the causes of cement concrete pavement diseases in high-cold and high-altitude areas and summarizes the common disease types of cement concrete pavements in high-cold and high-altitude areas. Moreover, new repair techniques to improve the maintenance quality of cement concrete pavements in high-cold and high-altitude areas are introduced.

Application Of Acoustic Emission Technology In Monitoring Corrosion Induced Expansion Cracks Of Reinforced Concrete, Zhen Zeng, Gang Xu, Rui Zhang, Zewen Yang

International Conference on Durability of Concrete Structures

Acoustic emission (AE) technology is used to monitor the whole process of reinforced concrete rust expanding and cracking, and the accuracy of AE technology to distinguish the location and type of cracks in concrete rust expanding and cracking is studied and verified. The results show that the protective layer is accompanied by a large number of acoustic emission signals in the process of rust expansion and cracking, Moment tensor inversion can more accurately identify crack sources such as shear source, tensile source and mixed source; In the process of corrosion-induced expansion cracking, shear source cracks appear before tensile source cracks …

Ultra- Ductile Waterborne Epoxy-Concrete Composite Repair Material, Bo Pang, Zuquan Jin, Yunsheng Zhang, Xiaoyun Song

International Conference on Durability of Concrete Structures

With the extension of service time, the building structure is in urgent need of repair and reinforcement due to its deterioration in safety and durability with the years. Normal cement concrete exposes shortcomings such as high brittleness and low flexural-tensile strength for which fails to meet the requirement of construction repairing. In this paper, a novel waterborne epoxy-concrete composite repair material (WECM) was prepared by using self-synthesized water-based epoxy resin based on the molecular structure-activity relationship. The key flexural and tensile performance parameters of WECM were accurately obtained.

Rheological Properties And Structural Build-Up Of 3d Printed Magnesium Potassium Phosphate Cement, Hui Zhi Zhao

International Conference on Durability of Concrete Structures

This paper focuses on the rheological properties of 3D printed magnesium potassium phosphate cements (MKPCs) with different magnesium-to-phosphate (M/P) mass ratio, MgO fineness and supplementary cementitious materials (SCMs) types. The variable shear rate tests were used to monitor the extrudability. The highest slope of the evolution of storage modulus (G') and the maximum static yield stress (M_τs) value were used as an indication of the rigidification rate. The increased M/P mass ratio, MgO fineness and SCMs addition resulted in the promoted structural build-up of 3D printed MKPCs. The consistency between the evolution of G' and M_τs with …

Mechanical Properties Of Engineering Cement-Based Materials Containing Modified Shape Memory Alloy Fiber, Song Mengfan

International Conference on Durability of Concrete Structures

在这项研究中，提出了一种 SMA 纤维的表面改性方法，以改善水泥基复合材料中纤维的界面性能。SMA 纤维涂有 SiO ₂，预计会与 Ca(OH) _2反应由水泥水化形成，减少了薄弱区的可能性，并在纤维-基体界面处形成了更致密的微观结构。采用扫描电子显微镜 (SEM)、能量色散光谱 (EDS) 和红外吸收光谱 (IR) 对表面改性后的 SMA 纤维进行表征。此外，还进行了抗弯强度试验、抗压强度试验和四点弯曲试验，以评价宏观尺度上界面力学性能的增强情况。实验结果表明，包覆的 SiO ₂，导致改性 SMA 纤维-水泥界面处的 CSH 凝胶量增加和孔隙率降低。改性后的SMA纤维与水泥基体之间的紧密粘附有利于建立更强的界面结合力，有利于提高抗弯强度、抗压强度、四点抗弯强度和挠度。抗弯强度、抗压强度、四点抗弯强度和挠度均在28d时显着增加。结果支持了所提出的表面改性方法适用于 SMA 纤维以提高其在工程水泥基材料中的增强效率的结论。

Super-Hydrophobic Hybrid Coatings Preparation Used By Methyltrithoxysilane (Mtes) And Tetraethylorthosilicate(Teos), Quanwei Li

International Conference on Durability of Concrete Structures

超疏水材料由于其优异的疏水自洁性能，在航空航天、海洋工程、除冰防腐等领域具有广阔的应用前景。本文采用简单的溶胶-凝胶制备超疏水涂层。 . 以甲基三乙氧基硅烷（MTES）和原硅酸四乙酯（TEOS）为前驱体，水解缩合后形成粗糙结构，1H,1H,2H,2H-全氟癸基三乙氧基硅烷（FAS）为低表面能的表面活性剂，系统研究了各自的最佳配比零件。涂层的疏水性和形貌分别通过水接触角测量、扫描电子显微镜（SEM）表征。同时，其官能团通过红外光谱表征。基于大量的实验和优化测试，

Effects Of Organic Corrosion Inhibitors On The Performance Of Repair Mortars, Ominda Nanayakkara Dr.

International Conference on Durability of Concrete Structures

Reinforced concrete (RC) structures are severely degraded due to the corrosion of the embedded reinforcing steel, and hence, the upgrading of RC structures is essential. Repairing mortar is widely used to improve durability and strengthen structures; however, further repairing might be required considering the extended life of the structure. The use of inhibitors to protect the reinforcement from corrosion has become of great interest. Therefore, it is vital to study the potential of using corrosion inhibitors in a newly repaired system.

This study investigated the performance of a commercially available polymer-modified mortar with migrating and admixed corrosion inhibitors. The study …

Corrosion Performance Of Embedded Steel Bar In Cl--Contaminated Limestone Calcined Clay Cement (Lc3) At Initial Stage Of Hydration, Weiwen Li, Zuhua Xu, Yaocheng Wang, Xin Wang, Feng Xing

International Conference on Durability of Concrete Structures

Limestone Calcined Clay Cement (LC3) presents brilliant properties in binding Cl^- so that the embedded steel bars are probably protected in Cl^--contaminated condition, which meets the need of sea sand application. However, the corrosion performance of steel bars embedded in LC3 paste with Cl^‑ is unclear, especially in early age hydration. Thus, a series of experiments were carried out to evaluate the corrosion performance of steel bars on initial and hardened stages of hydration, including concentration of OH^- and Cl^- in real pore solution, open circuit potential (OCP) and chemical elements of steel bars. …

Study On Strength And Volume Stability Of Coral Mortar, Qingzong Xue

International Conference on Durability of Concrete Structures

No abstract provided.

Mechanical Properties And Microstructure Of High Strength Lc3 Pastes With Varying Limestone/Calcined Clay Ratios And Different Curing Conditions, Yemin Dong

International Conference on Durability of Concrete Structures

研究（抗施工蒸馏）石石和石榴石在淀粉胶系统（即0标准和低水印）下的水胶系统（即0标准和低水墨）X射线比、水量值水量-电子背基相关研究.61.25 .25.25.25.0.25.25.25.25.25.0.25.25.25.25.25.1.25.7.25.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1.25.1.25.25.1.25.1.25.1.25.1.25.1.25.1 .25.1.25.1.25.1.25.1.25.1.25.0.0.0.0.0.0.0.00.0.0.1.25.1.25.1.25.1.25.1.25.0.0.0.00.0.0.0.0.0.0.0.0.0.0.0.0.0.00.0 .00.0.00.X射线比值、水量-电子显微镜相关研究测量值。早期的水泥水化程度小水的压合含煤量，降低了水泥石的。因此，需要采用合适的钙铝内容和体系以提高碳系统的性能。

Development And Properties Of Sulfate-Resistant And Corrosion-Inhibiting Admixtures, Tongwei Lu, Jie Zhang, Guisheng Cai, Linmao Wang, Xiangyang Guo

International Conference on Durability of Concrete Structures

Sulfate and chloride-induced corrosion of concrete and steel reinforcement are the most important causes of premature failure of durability of concrete structures. To prevent damage in concrete structures, the application of sulfate-resistant and corrosion-inhibiting admixtures has proven to be an effective method. In this study, a new type of corrosion-inhibiting admixtures including organic and special inorganic components are developed and the properties of mortar mixed with them was investigated. The results show that NC-CZ series of sulfate-resistant and corrosion-inhibiting admixtures have been successfully developed. The mortar with NC-CZ has good resistance to sulfate attack, whose corrosion resistance coefficient of mortar …

Study On The Effect Of Fly Ash On The Properties Of Potassium Magnesium Phosphate Cement, Bo Pang

International Conference on Durability of Concrete Structures

In this paper, the effect of fly ash on the setting time and mechanical properties of potassium magnesium phosphate cement is studied. The early hydration process of potassium magnesium phosphate cement was studied by TAM-Air, and the hydration products were analyzed by XRD. The results show that fly ash can effectively prolong the setting time and the compressive strength of the cement paste was decreased; The addition of fly ash would not change the phase composition of the hydration products of the potassium magnesium phosphate cement, which affect the hydration process, the amount of the hydration products and the degree …

Study On Hydration Properties Of Grinded Tuff-Cement Cementitious Material System, Hao Wang

International Conference on Durability of Concrete Structures

The chemical composition and microscopic morphology characteristics of grinded tuff(GT) and fly ash(FA) were compared and analyzed in the paper. The chemical bound water content and hydration heat were tested for investigating the hydration properties of grinded tuff-cement cementitious material system (GTCS) and fly ash-cement cementitious material system (FACS). The results shown that, the chemical composition of GT was similar with that of FA, however the loss on ignition of the GT was obviously higher than FA. The microstructure of the GT particles was polygonal and irregular, while the microstructure of FA particles were mostly smooth spheres. The hydrated heat …

Investigation On The Properties Of Calcium Sulfoaluminate Cement Waterproof Repair Mortar Modified With Ethylene-Vinyl Acetate Powder, Dong Dong

International Conference on Durability of Concrete Structures

本文采用乙烯-醋酸乙烯酯（EVA）粉体和CSA水泥制备了防水修复砂浆，并对其水化和性能进行了研究。结果表明，EVA粉体延长了凝固时间，提高了防水修补砂浆的流动性，使其在实际工程中更容易应用。EVA粉提高了防水修复砂浆的不渗透性，降低了吸水性。虽然EVA粉降低了防水修补砂浆的抗弯强度和抗压强度，但它仍然符合JC/T 2381-2016标准对刚性修复砂浆的要求。EVA粉体降低了防水修复砂浆的收缩率，改善了界面过渡区和拉伸粘接强度、弯曲粘接强度等粘接性能。EVA粉末抑制CSA水泥的水合作用6 h，在3 d水化年龄时抑制作用消失。

Shrinkage And Durability Of Cement Mortars With Recycled Aggregates, Wencui Yang

International Conference on Durability of Concrete Structures

In recent years, the rapid growth of economy and urbanization process in China resulted in the massive construction and demolition wastes (C&DW). The reutilization of C&DW as recycled aggregates (RA) fully or partially to replace natural aggregates is an effective way to solve the environmental and economic problems caused by C&DW. The properties of cement mortars could be influenced by recycled fine aggregates due to their high absorption and the quantity of fine particles. This paper presents the main results of the research to explore the effect of recycled aggregate (RA) on shrinkage and durability properties of masonry mortars. Four …