The optical properties of spherical gold
nanoparticles are calculated using classical
electrodynamics. The wavelength corresponding
to maximum extinction shifts to
longer wavelengths as the size of the
nanoparticle is increased. The influence of
higher-order multipoles is evident for large
nanoparticles, making the spectra more
complex. When the shell thickness of...
Every year millions of Americans go to the
emergency room with symptoms of a heart
attack. More than half a million Americans
die each year of myocardial infarctions (MI)
caused by coronary heart disease (CHD).
CHD detection is currently limited to EKG
analyses of electrical signals generated by
the heart...
Alzheimer’s disease (AD) is a progressive
mental disorder that affects 23 million people
worldwide. It is pathologically characterized
by amyloid plaques and tau tangles that
form in the brain. The hard, insoluble amyloid
plaques develop from the naturally
secreted amyloid beta peptide, which can
also assemble into toxic oligomeric forms...
Electron transfer theory predicts reorganization energy to be one factor that determines the electrochemical potential of a metal ion. This paper describes part of a study that aims to increase understanding of solvent reorganization energy in noncovalent systems by systematically varying the environment around a metal ion, specifically ruthenium. The...
This study investigated the precipitation
strengthening of the binary Al-0.14wt% Sc,
0.16% Ti alloy system. Ingots of Al-2.1wt% Sc
and Al-4.68wt% Ti were melted together, and
the nucleation, growth, and coarsening of
precipitates were analyzed. The microstructural
evolution of the nanoscale L12 precipitates
phase was examined with Vickers
microhardness testing,...
The effects of Ru, W, and Re on the temporal
evolution of the gamma prime precipitates in
a Ni-Cr-Al alloy were investigated by threedimensional
atom probe (3DAP) microscopy.
The spatial distribution of the gamma prime
precipitates in a model Ni-8.5Cr-10Al alloy
was investigated using atomic force
microscopy (AFM). We reported...
Fullerene and inorganic fullerene-like nanotubes
are molecules with the unique geometry
of a single layer or multiple layers of a bulk
material oriented in a tube. These molecules
have novel mechanical properties and great
potential in experimental systems for nanotechnology
and nanodevices. The threedimensional
atom-probe (3DAP) microscope
is an atomic...
While nanoscale device prototypes using
carbon nanotubes abound, no mass
production-scale technique exists for examining
properties of a batch of nanotubes.
Dielectrophoresis, on the other hand, has
received much attention in the press as a
method of separating and trapping particles.
In this research, a method of developing
mass production-scale...
Chemists and physicists have been interested
in the optical properties of metal nanoparticles
since the time of Michael Faraday.1
New approximation techniques for different
sizes and geometries have created renewed
interest in and investigation of these particles.
Many different arrays of particle extinctions
of various shapes and sizes have been...
In modern medicine, physicians destroy
otherwise healthy tissues in patients’ bodies
because of the lack of site-target specificity
and sensitivity in detecting and attacking
cancerous cells. Many cancer patients are
left with the difficult task of weighing the
benefits against the harm of undergoing
current cancer treatments. Members of the...
The effects of 13 nm Au colloid and 10 nm Ag
colloid on the growth of the yeast species
Saccharomyces cerevisiae were compared
to control samples cultured in a growth
media of yeast extract, bacto peptone, and
dextrose (YPD) to determine the toxicity of
nanoparticles. Growth curves were generated
for...
Transmission and reflection diffraction
gratings were fabricated by micropatterning
polymers on transparent substrates and
drop-coating polymers onto etched silicon
wafers. Exposure of these gratings to three
nerve toxin mimics at very low concentrations
resulted in mimic sorption by the polymers,
changing the polymer’s refractive
index. As a result, the grating’s...
Feedback-controlled lithography (FCL)
enables atomically precise patterning of
individual molecules on the technologically
significant Si(100)-2 x 1:H surface. However,
because it is performed in an ultrahigh vacuum
(UHV) environment, FCL has thus far
been restricted to surface chemistries that
can be delivered in the gas phase. The present
research attempts...
This research project explores two different
processes that can be used to pattern
organic molecules on silicon. In the first
process, hydrogen-terminated silicon surfaces
were anodized in nanometer scale with
a contact-mode atomic force microscope
(AFM). Anodization was done by applying a
positive bias voltage to the surface with
respect...
Recent research suggests that ultraviolet
illumination is essential for the creation of
monolayers of Undecylenic Acid Methyl
Ester (UDAME), as it is believed that the
UV illumination initiates the radical-chain
polymerization. Samples created without
UV illumination, however, also show signs
of a monolayer. In this study, samples were
analyzed using...
The development and applications of
organic/DNA molecules for the use of DNA
detection systems are reported here. In particular,
two different hybrids are synthesized:
DNA/polymer hybrids and small-molecule
DNA hybrids. DNA/polymer hybrids are especially
useful considering that their functionality
may be varied according to the polymer
selected. The hybrids are...
Several phosphonate-functionalized molecular
squares have been successfully synthesized,
and the fabrication of multilayer films
on both conductive and semiconducting
platforms has been demonstrated. These
films were grown using the well-documented
zirconium phosphonate multilayer method.
The layer-by-layer growth rate is uniform.
Experiments suggest, however, that the
molecular squares adopt a semi-collapsed...
Most people imagine hacking to be an exceedingly complex crime, requiring an understanding of computing systems that goes far beyond that of average, functionally literate PC users. While there are sophisticated hacking techniques which do fit this description, many forms of hacking require little more than the ability to install...
In February, British Prime Minister David Cameron announced that Britain would vote on the continuation of their membership within the EU. This has led to ministers quickly splitting into factions either in support or opposition to British exit from the EU, now often referred to as “Brexit”. Positions have been...
The recent military-style assault on the office of the French satirical magazine Charlie Hebdo , followed by a separate hostage standoff at a Kosher supermarket traumatized Paris and sent shock waves across Europe. The three-day terror spree in Paris ended with the deaths of 17 victims and three gunmen. The...
On February 13th, US Supreme Court Justice Antonin Scalia passed away, radically altering the makeup of the America’s highest court and raising the stakes for the 2016 presidential election. Mr Scalia leaves behind a Court that would be almost unrecognizable as the one he joined when he was appointed by...
The Asian Infrastructure Investment Bank (AIIB), a new international financial institution created by China, recently gained media attention following the induction of several new high-profile members. The bank was initially proposed by China and then launched last October with 20 other countries. Since then, many more nations – including some...
Welcome to the inaugural issue of Politica Northwestern . Politica Northwestern is the academic journal of Politics & Policy ( P&P ), a student publication at Northwestern University. P&P looks at the world in terms of what impact events will have. Political events happen all the time, but their impacts...
Innovative companies such as Uber and Airbnb have pioneered a new mode of business: the sharing economy. Uber, a car-sharing service, allows individual car owners to act as taxi drivers, connecting individuals seeking rides with those with cars willing to drive them, through a mobile app. Airbnb is a similar...
As the world continues to grapple with dramatically lower oil prices, economic and political implications for certain major oil producers are beginning to materialize. Some countries, like Saudi Arabia, the world’s largest petroleum exporter, were more prepared for the global downturn than others. Unlike many oil producers, the Saudis are...
On December 17th, Turkish police detained around 50 individuals accused of corruption and bribery. The scandal , which implicated Prime Minister Recep Tayyip Erdoğan, was that the arrested ranged from sons of government ministers to political allies in Turkey's financial sector. Thus began a new chapter in Mr Erdoğan’s battle...
For the better part of 2014, anti-government protests have been raging in Caracas, the capital of Venezuela. These protests received international attention when three people were killed on February 12th. Since then violence on the street has claimed 17 lives and injured hundreds of people. The protests, ostensibly anti-government in...
The Northwestern University Libraries Repository and Digital Curation (RDC)
department is tasked with digitising and creating digital collections from the materials managed by the Libraries’ curators. The previous process for the intake and management of these projects created a situation of feast or famine regarding project work that was ready...
We study centralized many-to-many matching in markets where agents have private information about (vertical) characteristics that determine match values. Our analysis reveals how matching patterns reflect cross-subsidization between sides. Agents are endogenously partitioned into consumers and inputs. At the optimum, the costs of procuring agents-inputs are compensated by the gains...
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...
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,...
In 2015, as part of the Reproducibility Project: Cancer Biology, we published a
Registered Report (Kandela et al., 2015) that described how we intended to replicate selected experiments from the paper “Coadministration of a tumor-penetrating peptide enhances the efficacy of cancer drugs“ (Sugahara et al., 2010). Here we report the...
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...
There have been numerous studies that have aimed at improving the low tensile strength, stiffness, and toughness of cementitious materials. This study aims to show that all of these characteristics can be greatly improved by the addition of ladder scale reinforcement at the nano and micro scale. Carbon nanofibers (CNFs)...
Concern over construction vibration-induced cracking has led to development of a new approach to vibration monitoring called autonomous crack measurement (ACM) and illustrated in Figure 1. This paper describes the concept as well as sensor performance in the first test house fitted an ACM system. Response of three cracks in...
This article summarizes an investigation of the structural response of a brick façade home in New Mexico. The subject Ricter residence was located some 1100 to 1400 ft away from an aggregate quarry, and was subjected to a maximum peak particle velocity and air blast over pressure of 0.29 ips...
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...
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...
The Avalon Media System (Avalon) provides access and management for digital audio and video collections in libraries and archives. The open source project is led by the libraries of Indiana University Bloomington and Northwestern University and is funded in part by grants from The Andrew W. Mellon Foundation and Institute...
In his essay on Mali, Bruce Whitehouse of Lehigh University shows how failures of elected leaders, state institutions, and external donors can shift power to the streets and an uncertain contest among armed forces.
The diverse circuits and functional contributions of the basal ganglia, coupled with known differences in dopaminergic function in patients with schizophrenia, suggest they may be an important contributor to the etiology of the hallmark symptoms and cognitive dysfunction experienced by these patients. Using activation-likelihood-estimation meta-analysis of functional imaging research, we...
We investigated the racial content of perceivers’ mental images of different socioeconomic categories. We selected participants who were either high or low in prejudice toward the poor. These participants saw 400 pairs of visually noisy face images. Depending on condition, participants chose the face that looked like a poor person,...
Many preventable behaviors contribute to adolescent mortality and morbidity. Non-adherence to preventive measures represents a challenge and has been associated with worse health outcomes in this population. The widespread use of electronic communication technologies by adolescents, particularly the use of text messaging (short message service, SMS) and mobile phones, presents...
Metabolic syndrome has become a major public health challenge worldwide. The association between metabolic syndrome and DNA methylation is of great research interest. We constructed a binomial model to investigate the association between a metabolic syndrome index and DNA methylation in the Normative Aging Study. We applied the Iterative Sure...
The Affordable Care Act (ACA) has expanded health coverage for thousands of Illinois residents. Expanded coverage, however, does not guarantee appropriate health care. Diabetes and its ocular complications serve as an example of how providers in underserved urban areas may not be able to keep up with new demand for...
When making serial predictions in a binary decision task, there is a clear tendency to assume that after a series of the same external outcome (e.g., heads in a coin flip), the next outcome will be the opposing one (e.g., tails), even when the outcomes are independent of one another....
Electronic and vibrational correlations report on the dynamics and structure of molecular species, yet revealing these correlations experimentally has proved extremely challenging. Here, we demonstrate a method that probes correlations between states within the vibrational and electronic manifold with quantum coherence selectivity. Specifically, we measure a fully coherent four-dimensional spectrum...
In the United States, African-Americans’ (AAs) HIV infection rates are higher than any other racial group, and AA men who have sex with women (MSW) are a significant proportion of new cases. There is little research into AA MSW HIV/AIDS knowledge, barriers, and facilitators of HIV testing in Chicago. We...