Digital Commons Network^™

The Biomechanics Of Tooth Strength In Australopiths, Rachel Sender

Arts & Sciences Graduate Student Theses and Dissertations

Teeth must fracture foods while avoiding being fractured themselves. This dissertation consists of three studies aimed at assessing adaptations of molars that may confer biomechanical strength against certain types of diet. The first study evaluates dome biomechanical models used to describe tooth strength. The second study tested the hypothesis that australopith molars, which have enlarged molars and thick enamel, are mechanically strong and well adapted to withstand high bite forces. The third study tested biomechanical predictions derived from experiments performed on a dome model that examined how tooth strength changes at progressive stages of wear under loading regimes representing different …

Rethinking Higher Education For The 4th Industrial Revolution: Synergetics In Global Social Transformations And Society Building, Danjoo N. Ghista, Ravi S. Sharma

All Works

This paper highlights the need for our Rethinking Education towards a global common good and cultivating New Era Universities for the 4th Industrial Revolution (4IR). 4IR represents a fundamental change in the way we live, work, and relate to one another. It is a new chapter in human development, enabled by extraordinary technological advances commensurate with those of the first, second, and third industrial revolutions. Indeed, the 4th Industrial Revolution measures up with the Post-Capitalist Society, involving policies catering to human living needs, enabling people to have a Neo-humanist outlook, and come together to form a universal and more evolved …

Risk Assessment Calculation Of Layered Surrounding Rock Tunnel Based On Combination Weight-Eahp-Ncm Model Theory, Yang Yongbin, Wang Qing, Wang Yijun, Gao Weizheng, Li Yongliang

Journal of China & Foreign Highway

To accurately assess and calculate the structural stability of layered surrounding rock tunnels during construction, this paper firstly constructed a risk assessment index system for layered surrounding rock tunnels based on the consideration of factors of hydrogeology, structural surfaces, engineering, external forces, and topography and geomorphology. Based on the Delphi method (DELPHI) and entropy weight method (EWM), the combination of indicators was assigned. Based on the typical event samples and the mining of classical domains-joint domains of the assessment system, the extension analytic hierarchy process calculation model (EAHP) and normal cloud computing model (NCM) were built to assess the stability …

Optimization Design Of Highway Tunnel Inner Contour Based On Simu Lated Annealing Algorithm, Zhang Qingwei

Journal of China & Foreign Highway

To optimize the inner contour design of road tunnels, this paper regarded the inner contour design of a road tunnel as an optimization problem in certain conditions. By taking the area optimization as the objective, it introduced the simulated annealing algorithm to solve the problem based on the calculation model building of the inner contour of a single-centered circle with an inverted arch, with a program written for verification and analysis. The results show that the optimization design scheme is feasible and can provide an idea way for the inner contour design of road tunnels.

Review Of Material Composition And P Erformance Evaluation Of Cold Patch Asphalt Mixture, Yang Yanhai, Zhu Guangxu, Yang Ye

Journal of China & Foreign Highway

To summarize the latest research achievements of cold patch asphalt mixtures at home and abroad, and to promote their development and application, this paper firstly introduced the development history of cold patch asphalt mixtures domestically and internationally, and focused on summarizing the classification and material selection of materials, as well as common mix ratio design methods. Secondly, it reviewed and analyzed the influencing factors of performance evaluation of the mixtures. Finally, such problems as the strength effect mechanism and the link between the material and performance, and the future research directions were combined to establish a unified and effective evaluation …

Study On Low Temperature Performance Of Asphalt Mixture Under Salt Freezing Condition, Song Yunlian, Gao Pan, Jiang Yu

Journal of China & Foreign Highway

To investigate the ice-melting ability of snow-melting agents and the effect of different salt freezing conditions on low temperature performance of asphalt mixtures, this paper carried out the ice-melting ability test, beam bending test and beam bending creep test. The results show that under the temperature of -20℃ and concentration 30% or more of the snow-melting agent, the ice can be melted. However, the melting ice quality is small. In terms of melting ice quality, the melting ability of the P-type snow-melting agent is better than that of the H-type snow-melting agent. Under the temperature of -10‒0℃, the recommended concentration …

Research On Performance Simulation Of Previous Concrete Considering Characteristics Of Void Structures, Zheng Shuai, Dan Jingsong, Han Weiwei, Lv Yigang, He Jie, Pei Fucai

Journal of China & Foreign Highway

Pervious concrete contains a large number of macroscopic voids. To analyze the influence of the void structures on the mechanical properties of pervious concrete, this paper adopted the random void method to build a simulation model of pervious concrete, and study the effect of the characteristics of the void structures on the force properties. Firstly, two kinds of pervious concrete specimens with two void content levels were made indoor, and then the specimens were cut after curing and molding. Next, image enhancement and threshold segmentation were conducted on the section images of the cut surfaces, and two-dimensional digital images of …

Study On Frost Resistance And Pore Structure Of Nano-Sio 2 Modified Pavement Concrete Under Fatigue Load, Zhou Xuexiang, Zheng Wenshi, Wu Cong

Journal of China & Foreign Highway

To improve the frost resistance of concrete pavement under fatigue load, this paper simulated the freeze-thaw damage of concrete pavement under vehicle load by indoor fatigue loading and alternating freeze-thaw cycling test. Meanwhile, it designed the bending tensile test to test the residual bending tensile strength of nano SiO2-modified pavement concrete after freezing and thawing, and adopted the mercury injection method to test the microscopic pore structures of concrete. Additionally, by employing the electron microscope, the change rules of pores in the concrete under the action of fatigue load were observed, and the effect of nano SiO2 dosage, the number …

Influence Of Natural Environment On The Serviceability Of Emulsified Asphalt Cold Recycled Mixture, Yang Puxin

Journal of China & Foreign Highway

To improve the early serviceability of emulsified asphalt cold recycled mixtures, this paper studied the effect of curing conditions on the mechanical strength and stability of emulsified asphalt cold recycled mixtures by conducting indoor tests. The results show that in the same test conditions, the indoor emulsified asphalt cold recycled mixture can better characterize the serviceability of practical projects. Compared to the indoor specimen mixture, the stability and cleavage strength of field mixture core samples are increased by an average of 5.5% and 10.7% respectively. Under the curing time of no less than 7 d, the stability, cleavage strength and …

Experimental Study On Recycled Brick Powder Foam Concrete Based On Slurry Substitution Method, Liao Shixian, Huang Lei

Journal of China & Foreign Highway

Foam concrete is a kind of porous lightweight building material characterized by sound insulation and noise reduction, heat insulation and fire resistance, heat preservation and frost resistance. However, it has defects such as low strength, high porosity and poor integrity, thus limiting its wide application in the field of building materials. Recycled brick powder can be prepared from construction waste of clay bricks and has certain volcanic ash activity. Meanwhile, the mechanical properties of foam concrete can be improved by employing waste bricks as an admixture in cement-based composite materials. In view of the problems of the cement substitution method, …

Study On Mix Design And Performance Of Permeable Concrete Considering Sand Ratio And Aggregate To Binder Ratio, Wei Yazhou, Ji Rongqing

Journal of China & Foreign Highway

Considering the effect of the sand ratio and aggregate to binder ratio, this paper improved the traditional mix ratio design method-volumetric method, and investigated the influence of the sand ratio, aggregate to binder ratio, and maintenance method on the mechanical properties and permeability coefficient of pervious concrete based on the improved method. The results show that under the sand ratio of 15%, the compressive strength of concrete is significantly increased and the permeability is not affected. When the aggregate to binder ratio is 3.0‒3.1, the compressive strength and permeability coefficient of the concrete can be both considered. Additionally, compared to …

Application Of Dry Sbs Modification Technology In Yanhai Highway, Zhang Han, Meng Chunlin, Zhao Mingfang, Lu Chuanzhong, Ji Guoqi

Journal of China & Foreign Highway

Dry SBS-modified asphalt pavement technology is to produce SBS-modified asphalt mixtures by adding specific SBS modifiers, which aims to solve the performance degradation of SBS-modified asphalt in transportation and storage. By relying on the coastal highway repair projects, this paper compared the effects of different dry SBS mixing contents on the test results by the indoor dry SBS and matrix asphalt compatibility test and asphalt mixture performance evaluation test. Meanwhile, based on the test results, the recommended dry SBS mixing content for the coastal highway upper layer milling and resurfacing maintenance project was proposed and applied on a large scale …

Experimental Study On Mechanical Properties Of Steel-Polypropylene Mixed Fiber Rubber Concrete, Qiu Jiandong

Journal of China & Foreign Highway

Waste rubber materials can be recycled to obtain rubber aggregates, which can be employed in cement concrete products. This paper carried out mechanical performance tests on ordinary concrete and rubber concrete (rubber substitution rate of 20%) with different fiber combinations (doped MS, co-doped PP, and mixed MS-PP), and mainly examined the slump, density, compressive strength, modulus of elasticity, split tensile strength, and rupture strength of the concrete. The results show that the relevant performance indexes decrease significantly after 20% of rubber aggregate is added to the concrete. However, the mechanical performance of ordinary concrete and rubber concrete with the combination …

Analysis Of Light Reflection And Automobile Exhaust Degradation Effect Of Asphalt Pavement Coating, Shang Wenyong, Zhou Zheng, Chen Jun

Journal of China & Foreign Highway

To compare the light reflection and exhaust degradation effect of common road coating fillers, this paper prepared three kinds of road surface coatings with Nano-TiO2, Nano-ZnO, and Micro-TiO2 as fillers respectively. Meanwhile, the reflectivity tests of the coatings with different mixing contents of fillers were conducted by adopting a self-developed light reflectivity tester to determine the optimal mixing content of fillers. Under the optimal mixing content of fillers, the reflectivity of three kinds of coating asphalt mixtures was tested to compare the light reflectivity effect of Nano-TiO2, Nano-ZnO and Micro-TiO2. Additionally, a self-developed exhaust concentration analyzer was utilized to test …

Study On Effect Of Nanomodified Additives On Properties Of Concrete Mixtures During Winter Season, Li Yulin, Liang Hongjie, Liang Junlin, Rong Hongliu, Yang Xiaolong

Journal of China & Foreign Highway

To solve the difficult placement of small structures on highways caused by the decreasing workability of cement concrete construction in winter seasons, this paper developed a nanomodified additive to investigate its effect on the performance of cement concrete. Sulfonate naphthaleneformaldehyde (SNF), nanoSiO2, rosin soap (WSR) and sodium nitrate (NaNO3) were formulated into a variety of additives in different ratios and mixing contents to prepare cement concrete, with the fluidity, segregation and compressive strength studied. The results show that the optimal ratio (mass) of nanomodified additives is SNF:0.4%, nanoSiO2:0.1%, WSR:0.05%, and NaNO3:4.0%. The fluidity, segregation and compressive strength of the concrete …

Comparison Of Specifications For Highway Safety Audi Ts Of China ， The United States ， And Australia, Li Jie, Han Huanhuan, Li Jia, Ren Yabo, Gong Ruiming

Journal of China & Foreign Highway

Traffic safety is one of the three major problems of transportation. To build a transportation power, China has proposed the call of “facilitating the transportation development from pursuing the speed and scale to paying more attention to quality and safety”, and improving the audit specifications of road safety is an important basis for increasing the transportation safety level. This paper firstly introduced the background where China, the United States and Australia issued the audit specifications of road safety, and then compared the differences between the three countries in the aspects of the audit process for road safety, audit indexes and …

Application Of Bim Forward Design In Complex Three-Dimensional Traffic Design Stage, Wang Bo, Zhu Xinghu, Pei Wangjian, Ge Puta

Journal of China & Foreign Highway

To improve the accuracy and efficiency of complex three-dimensional traffic design, and provide basic digital data for the whole life cycle, this paper researched and investigated the application of BIM technology in the complex three-dimensional traffic design stage by taking the convergence project of the Qianhai section of Shenzhen Coastal Expressway and Nanping Expressway in Guangdong as a case study. Meanwhile, it put forward the BIM forward design schemes for the fields of roads, bridges, and tunnels, carried out secondary development, and built the three-dimensional parametric model, with the design results optimized. Additionally, design analysis and application were conducted to …

Research On Interchange Reconstruction Design Of Minxiao Hub, Hu Tian, Tan Ximing, Yi Xuebin, Wei Hui

Journal of China & Foreign Highway

Based on the design of the Minxiao hub interchange, this paper analyzed the technical problems of frequent traffic accidents after the initial reconstruction of Minxiao hub interchange, and put forward corresponding reconstruction suggestions. In the interchange design details, the design points about the dual lanes adopting single lanes and speed change lanes only put forward the distance requirement of 60 m for the transition sections, but whether the gradual changes of the travel lanes and hard shoulders are completed in the same road section or not is not clarified. The initial reconstruction of Minxiao hub interchange is designed to complete …

Research On A Hub Interchange Scheme Under Special Terrain Conditions, Wang Jie, He Yajun

Journal of China & Foreign Highway

By combining the study process and conclusion of the interchange scheme of the Lugao hub as an important node of G4216 Jinyang-Ningnan Expressway Project, this paper discussed the ideas and methods of selecting the hub interchange shape under complex terrains and high functional requirements. It aimed to provide certain references for the design of hub interchange schemes in special Y-shaped terrain conditions. The Lugao hub interchange location is deeply cut by the Jinsha River and its branches, with narrow valley bottoms, extremely steep cross slopes, and harsh engineering construction conditions. Meanwhile, in the limited space, the specific requirements of the …

Instructors At A Crossroad: Perceptions Of Collaboration And Support Intersect With Intentions To Implement A Cure, Justin Berl

Dissertations and Theses

An ongoing crisis of student drop-off from undergraduate science, technology, engineering and mathematics (STEM) education has led to a sustained call over the last 15+ years for the increased implementation of updated practices in undergraduate STEM education. Though over the past few decades many researchers have developed and analyzed the efficacy of various evidence-based teaching practices (EBTPs) designed to improve the state of undergraduate STEM education throughout the country, the rate at which these EBTPs are implemented in undergraduate STEM classrooms remains low.

In order to better understand the specific factors that affect individual instructors' efforts to implement EBTPs, we …

Heterogeneous Gaze Tracking Sensor Systems, Methods, And Devices, Yatong An, Youmin Wang, Gaetano Aiello

Defensive Publications Series

Systems, methods, devices, and computer program products are provided for eye tracking and gaze pattern determinations using heterogeneous sensor systems. A first sensor system may track movement of a first eye, and a second sensor system may track movement of a second eye, wherein the second sensor system applies a different tracking method than the first sensor system. Tracking information received from the first sensor and the second sensor may be correlated to determine a gaze motion pattern, such as a three-dimensional motion pattern. The heterogeneous nature of the sensors enables realization of numerous advantages, including but not limited to …

A Low-Complexity Algorithm To Determine Spacecraft Trajectories, Sirani Perera

Math Department Colloquium Series

The growing traffic within the Cislunar region has created a need for computationally effective methods to obtain the trajectories of spacecraft in the Cislunar region. By developing algorithms with low time and arithmetic complexities, we can effectively address these needs.

In this talk, we will present a mathematical model that uses interpolation and boundary conditions to obtain trajectories for satellites based on the principles of three-body dynamics. Following the model, we propose a low- complexity algorithm to generate satellite trajectories. Once the algorithm is proposed, we will apply it to the relevant periodic orbits in the Cislunar region. Finally, we …

Microplastics In Water, Their Effects On The Aquatic Ecosystem And Human Public Health, And The Proposed Solutions, Mohanad Abouserie

The Undergraduate Research Journal

We could be swallowing a credit card's weight in plastic every week. Microplastic water pollution is becoming a threat to both humans and aquatic creatures. In this research, microplastic water contamination is discussed, and divergent solutions are proposed. This paper attempts to investigate the causes and effects of such pollution and analyze the current solutions for this issue. The adopted research method is secondary research, where several studies are explored and analyzed. This study explains numerous causes for this issue like cosmetics, cleaning products, factories, and sewage. Consequently, this contamination can negatively impact the organs and metabolisms of the living …

Anti-Inflammatory And Antioxidant Effects Of Sea Urchin Spine Extract, Dina Magdy El Gamal

The Undergraduate Research Journal

Diadema savignyi spine extract in an experimental setup using L929 cell line in vitro. The cell metabolic activity of L929 cells is tested through an MTT assay. The sea urchin spine extract is applied to the cells in two concentrations: 100 μg/ml (136% viability) and 200 μg/ml (95% viability). The bioactive components of the sea urchin spine are identified via GC-MS, and the antioxidant and anti-inflammatory activities are evaluated using catalase assay (CAT), glutathione (GSH), and nitric oxide (NO) tests. Results show that the GC-MS identified bioactive components including the anti-inflammatory and anti-irritant bisabolol oxide and the pro-inflammatory oleic acid. …

The 2011 Somalia Famine, Aya Ahmed

The Undergraduate Research Journal

In early 2011, the citizens of Somalia became unable to access basic human necessities such as food and water until the situation changed dramatically, leading to the daily death of thousands of human beings. This research paper tackles the negative consequences resulting from the Al-Shabaab movement, a movement who has the belief that applying the Sharia (Islamic Law) is the only valid solution to any issue as it is supported by the Sunni Islam, political issues, and the delay of the famine’s declaration. This research begs several questions which are: what were the factors which led to Somalia’s famine in …

Review Paper: Low Salinity Water Injection For Enhanced Oil Recovery, Mahmoud Ali, Moamen Talaat, Abd El-Rahman Rashwan

The Undergraduate Research Journal

Low salinity water injection (LSWI) is one of the leading techniques in terms of enhancing oil recovery in sandstone and carbonate formations. Many studies and lab experiments were performed on the LSWI applications. Some studies have pointed out multiple negative observations, while other studies have shown the positive potential of using LSWI in enhancing oil recovery. However, the technology used in LSWI applications is still considered new and more studies need to be performed to figure out new technologies that are low-cost and more efficient. This review paper examines LSWI by analyzing the benefits and drawbacks of employing LSWI in …

Safety Glasses To Aid Attention Focus

Defensive Publications Series

Methods, devices, and systems for aiding attention focus are described herein. In one aspect, a method can include receiving, from a sensor of a pair of eyeglasses, status information corresponding to a user of the pair of eyeglasses; determining, from the status information, the user is experiencing an unsafe condition; and transmitting an alert, via the pair of eyeglasses, to the user based on the determining.

Revealing Gene Regulation-Based Neural Network Computing In Bacteria, Samitha S. Somathilaka, Sasitharan Balasubramaniam, Daniel P. Martins, Xu Li

School of Computing: Faculty Publications

Bacteria are known to interpret a range of external molecular signals that are crucial for sensing environmental conditions and adapting their behaviors accordingly. These external signals are processed through a multitude of signaling transduction networks that include the gene regulatory network (GRN). From close observation, the GRN resembles and exhibits structural and functional properties that are similar to artificial neural networks. An in-depth analysis of gene expression dynamics further provides a new viewpoint of characterizing the inherited computing properties underlying the GRN of bacteria despite being non-neuronal organisms. In this study, we introduce a model to quantify the gene-to-gene interaction …

Sctiger: A Deep-Learning Method For Inferring Gene Regulatory Networks From Single-Cell Gene Expression Data, Madison Dautle

Theses and Dissertations

Inferring gene regulatory networks (GRNs) from single-cell RNA-sequencing (scRNA-seq) data is an important computational question to reveal fundamental regulatory mechanisms. Although many computational methods have been designed to predict GRNs, none work on condition specific GRNs by directly using paired datasets of case versus control experiments, common in diverse biological research projects. We present a novel deep-learning based method, scTIGER, for GRN detection by using the co-dynamics of gene expression. scTIGER also employs cell type-based pseudotiming, an attention-based convolutional neural network method, and permutation-based significance testing to infer GRNs from gene modules. We first applied scTIGER to scRNA-seq datasets of …

Resilin Distribution And Abundance In Apis Mellifera Across Biological Age Classes And Castes, Audrey Anderson, Noah Keime, Chandler Fong, Andrew Kraemer, Carol Fassbinder-Orth

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The presence of resilin, an elastomeric protein, in insect vein joints provides the flexible, passive deformations that are crucial to flapping flight. This study investigated the resilin gene expression and autofluorescence dynamics among Apis mellifera (honey bee) worker age classes and drone honey bees. Resilin gene expression was determined via ddPCR on whole honey bees and resilin autofluorescence was measured in the 1m-cu, 2m-cu, Cu-V, and Cu2-V joints on the forewing and the Cu-V joint of the hindwing. Resilin gene expression varied significantly with age, with resilin activity being highest in the pupae. Autofluorescence of the 1m-cu and the Cu-V …