Non-destructive evaluation (NDE) techniques have been used for a number of years to provide quality control of construction procedures for drilled shafts and driven concrete piles. In particular sonic echo and impulse response methods have been used extensively to check lengths and continuity of newly-installed foundations. In recent years, the...
This final report provides information about TEA-21 [Transportation Equity Act for the 21st Century] funded projects designated A433, and A495 "Evaluation of Capacity of Micropiles Embedded in Dolomite". The report was submitted to the Infrastructure Technology Institute at Northwestern University by Richard J. Finno on September 20, 2002.
This presentation provides information on the progress report of the project "Empirical Study of Life-Cycle Cost Analysis for Bridges" by Ahmad Hadavi, 2003.
A study is conducted to determine the effects on the early hydration kinetics and
compressive strength by seeding of Portland cement and alkali-activated blast furnace
slag with a pure form of calcium silicate hydrate (C-S-H). The effects of C-S-H seeding
during the early nucleation and growth period of each type...
The objective of this program is to measure the changes in the properties of the C-S-H gel phase in cement paste as a function of the Ca/Si ratio. The motivation is to better understand the hydration products that form in blended cements with lower Ca/Si ratios than portland cement. The...
Few would argue that concrete is an important and useful material: after all, concrete is the backbone of the world’s infrastructure, used in vast amounts to make roads, buildings, bridges, and other structures. But sometimes familiarity breeds contempt. To most people, concrete is simply that boring grey stuff that we...
This presentation provides information on the project "Safety Concrete - a Material Designed to Fail" by Jeffrey J. Thomas, Julie Gevrenov, Hamlin Jennings, and Edward O'Neil. The presentation was delivered at the 106th Annual Meeting & Exposition of The American Ceramic Society, Indianapolis, Indiana in 2004.
The mission of the Infrastructure Technology Institute is to develop strategies and tools
to protect and improve the condition, capacity and performance of the nations highway, railroad,
and mass transit infrastructure systems. The Institute does this through the development
and deployment of (1) advanced technologies for structural health monitoring, (2)...
This study tested a dynamic traffic assignment (DTA) model as a tool for pre-planning strategies for managing major freeway incidents. Incidents of varying scale and duration were modeled in the northern Chicago highway network, and the impacts of incidents and response actions were measured in terms of both lane-mile-hours of...
This presentation contains information about the project "The future of transportation... and how we'll pay for it" by Joseph L. Schofer, Department f Civil & Environmental Engineering. The presentation was delivered at the 40th Anniversary Seminar Day at Northwestern University on April 18, 2009.
Gentrification - the process in which higher income (and often younger) households displace lower income residents of a city neighborhood - has been occurring in many urban neighborhoods over the last few decades. This process changes the demographics, and often the essential character, of the neighborhood. As a result, we...
This presentation contains information on the project "Aligning Data to Support Transportation Decisions, Emerging Challenges & Opportunities for the Data World". The presentation was delivered by Joseph L. Schofer at Transportation Research Board – AASHTO Peer Exchange meeting on May 15-16, 2008.
The paper deals with the behavior of fluid cement pastes, formulated from Self Consolidating Concretes (SCCs), and the experimental correlation of fundamental rheological properties, such as the yield stress and the viscosity, with measurements from field tests, such as the mini-cone slump flow test. As a matter of fact, several...
The concrete currently used in the slip-form paving process is a low slump concrete that requires both internal and external vibration in order to achieve satisfactory compaction. The use of vibrator fingers for the internal vibration often leads to trails on the surface of the pavement and to segregation around...
This presentation contains information on the keynote paper "Health Monitoring of Early Age Concrete". The presentation was delivered by Surendra P. Shah at CONSEC'04 in Seoul, Korea on June 30, 2004.
The setting and hardening process of concrete can be considered as the most critical time period during the life of a concrete structure. To assure high quality and avoid problems in performance throughout the life of the material, it is essential to have reliable information about the early age properties...
The gradual evolution of the material properties of a cement-based material, i.e. the stiffness of cement paste, is the result of the continuous change of the microstructure with the progress of the hydration process. Based on an existing micromechanical model for the simulation of the shear and elastic modulus of...
The setting and hardening process of concrete is considered to be the most critical time period during the life of a concrete structure. Previous research has been conducted on an ultrasonic wave reflection method that utilizes a steel plate embedded in the concrete to measure the reflection loss of shear...
The nondestructive, in-situ testing of early-age concrete properties is a crucial point for the progress of many construction projects in the building sector. The application of such techniques can establish e.g. the earliest possible form removal from concrete construction elements, thereby opening highways to traffic or releasing prestress from steel...
In this paper, the correlation of reflection loss measured by an ultrasonic shear wave reflection
method and the microstructure in cement-based material is investigated. Three cement pastes
(Portland cement type I) with different water-cement ratios (0.35, 0.50 and 0.60) cured at 25
°C were examined. The ultrasonic shear wave reflection...
The Center for Advanced Cement-Based Materials (ACBM) is a consortium of researchers from: Northwestern University, University of Illinois at Urbana-Champaign, Purdue University, The University of Michigan, and The National Institute of Standards and Technology. This ACBM update contains information on the article "A better Maturity Meter?" by Surendra P. Shah...
Recent work using the eye movement monitoring technique has demonstrated that when people are engaged in thought they tend to disengage from the external world by blinking or fixating on an empty portion of the visual field, such as a blank wall, or out the window at the sky. This...
What makes a musician? In this review, we discuss innate and experience-dependent factors that mold the musician brain in addition to presenting new data in children that indicate that some neural enhancements in musicians unfold with continued training over development. We begin by addressing effects of training on musical expertise,...
A randomized experiment was conducted to assess the effectiveness of three forms of e-mail appeals to prospective members of a newly formed professional group. The baseline condition consisted of an impersonal appeal; prospective members were sent a mass e-mail encouraging them to join. Participants in the personal condition received an...
Perhaps better suited for the mosh pit than the orchestra pit, David Lang’s 1991 tour-de-force for solo bass clarinet, Press Release, is a minimalist marvel. Comprised of seven “groove sections” that evolve in seemingly unpredictable ways, Lang cleverly employs monophony to tell a robust story of motivic and harmonic development....
This paper describes proposed schemes for describing and indexing two image collections and requirements for the software that would give the end-user access to thesaurus terms and a graphical display of the faceted classification structures of indexing records. Editorial cartoons comprise one collection, dance videos the other.
In the Western classical art music tradition, a high level of music performance is achieved at the intersection of a musician's emotional, cognitive, and physical processes. Expert classical musicians have both an aural imagining of the sound they intend to produce and the physical associations of what it feels like...
This study explored the mentoring experiences of doctoral students in science, technology, engineering, and mathematics (STEM) doctoral degree programs at Northwestern University. Research suggests that mentoring relationships support student success in STEM disciplines, and further, that lack of mentorship may be a barrier for female students. A mixed-methods approach employing...
Trees in urban areas offer ecosystem services like carbon sequestration, storm water attenuation, reduction of energy used in buildings and wildlife habitat. Cities invest substantial funds and resources to maintain a healthy urban forest, and much research has been done to improve its resiliency and sustainability. Studies have been done...
In 1936 Modibo Keita, a twenty-year-old student at the distinguished Ecole William Ponty in Gorée, Senegal, wrote his “mémoire de fin d'étude” on Soninke childhood. The original manuscript is held in the archives of French West Africa in Dakar, part of the collection of “cahiers de William Ponty.” This paper... and En 1936 Modibo Keita, un étudiant de vingt ans à l'école distingué William Ponty à Gorée, au Sénégal, a écrit son mémoire de fin d'étude sur l’enfance sarakollé. Le manuscrit original se trouve dans les archives de l'Afrique occidentale française à Dakar, où il fait partie de la collection de...
Impairments in the social use of language, or pragmatics, constitute a core characteris-tic of autism. Problems with pragmatic language have also been documented in fragile X syndrome (FXS), a monogenic condition that is the most common known genetic cause of autism. Evidence suggests that social cognitive ability, or theory of...
The saxophone has long been an instrument at the forefront of new music. Since its invention, supporters of the saxophone have tirelessly pushed to create a repertoire, which has resulted today in an impressive body of work for the yet relatively new instrument. The saxophone has found itself on...
From 2008 to 2019, a range of new interactive and immersive digital formats that present new possibilities for musical and artistic expression have become available. In order to begin the work of uncovering what new compositional and experiential possibilities are now possible, this document will examine each format’s core concepts...
This file contains the supplementary online material that should accompany the paper "Defining and Measuring the Influences of GIS-Based
Instruction on Students’ STEM-Relevant Reasoning", published in Journal of Geography.
A longstanding goal of synthetic biology has been the programmable control of cellular functions. Central to this is the creation of versatile regulatory toolsets that allow for programmable control of gene expression. Of the many regulatory molecules available, RNA regulators offer the intriguing possibility of de novo design – allowing...
Recent advances in cell-free gene expression (CFE) systems have enabled their use for a host of synthetic biology applications, particularly for rapid prototyping of genetic circuits and biosensors. Despite the proliferation of cell-free protein synthesis platforms, the large number of currently existing protocols for making CFE extracts muddles the collective...
In many dryland environments, vegetation self-organizes into bands that can be clearly identified in remotely-sensed imagery. The status of individual bands can be tracked over time, allowing for a detailed remote analysis of how human populations affect the vital balance of dryland ecosystems. In this study, we characterize vegetation change...
Advances in biosensor engineering have enabled the design of programmable molecular systems to detect a range of pathogens, nucleic acids, and chemicals. Here, we engineer and field-test a biosensor for fluoride, a major groundwater contaminant of global concern. The sensor consists of a cell-free system containing a DNA template that...
Restoration practitioners have many seed material choices when restoring plant communities, and for some species, cultivars may be the most affordable and accessible material available. However, the process of plant selection and commercial seed production can limit trait variability critical to survival and persistence in heterogeneous environments. Several studies have...
Understanding how root traits vary within a species and how traits respond to heterogeneous environments, can provide important insight into functional plant attributes that influence plant survival in competitive environments. Selecting plant material with root traits that will support its survival in heterogenous environments may help improve the outcomes of...
There is growing evidence that growth with invasive species influences the traits of co-occurring native plants over multiple generations. Some studies indicate that these experienced populations perform better in the presence of the invasive species that led to the trait changes. These experienced populations could serve as source material for...
Soil texture has important ramifications on the shape and size of roots as well as impacting how much water is taken up and the distribution of nutrients in the soil. These factors lead to differences in growth characteristics and plant performance. However, what traits and how the plant responds to...
Advances in machine learning and artificial intelligence (AI) are enabling computers and robotics to take on an increasing number of work-related tasks that previously were the sole domain of humans. This trend raises questions: Which jobs will be most susceptible to replacement by automation? How many workers risk being replaced?...
This is an attempt to recreate a reference architecture with the intention of completing a data engineering capstone project and also learning the services and technologies along the progress. The objective of the project is to use aws cloud managed services to build at scale solution to process, parse and...