Nanoscale spectroscopic origins of photoinduced tip-sample force in the midinfrared.

When light illuminates the junction formed between a sharp metal tip and a sample, different mechanisms can contribute to the measured photoinduced force simultaneously. Of particular interest are the instantaneous force between the induced dipoles in the tip and in the sample, and the force related to thermal heating of the junction. A key difference between these 2 force mechanisms is their spectral behavior. The magnitude of the thermal response follows a dissipative (absorptive) Lorentzian line shape, which measures the heat exchange between light and matter, while the induced dipole response exhibits a dispersive spectrum and relates to the real part of the material polarizability. Because the 2 interactions are sometimes comparable in magnitude, the origin of the chemical selectivity in nanoscale spectroscopic imaging through force detection is often unclear. Here, we demonstrate theoretically and experimentally how the light illumination gives rise to the 2 kinds of photoinduced forces at the tip-sample junction in the midinfrared. We comprehensively address the origin of the spectroscopic forces by discussing cases where the 2 spectrally dependent forces are entwined. The analysis presented here provides a clear and quantitative interpretation of nanoscale chemical measurements of heterogeneous materials and sheds light on the nature of light-matter coupling in optomechanical force-based spectronanoscopy

Successful Design of Electronic Commerce Environment: On the Role of Sense of Presence in User Behavior

Despite the various benefits of the Internet/World Wide Web (Web) as a business transaction tool, such as lower search cost and greater selection of goods [Bakos 1998], and the millions of web-site visits, serious conduct of electronic commerce (EC) on the web by individual consumers does not appear to have taken root [Jarvenpaa & Todd 1997]. Notwithstanding security and privacy concerns [Kiely 1997], it appears that the current EC systems do not address varying levels of user needs. They fail to provide the rich commerce environment that users typically experience in a physical world; this deficiency might fail to arouse motivation or interest in carrying out “real transactions”. For instance, in a physical commerce environment, consumers can touch and feel the products and freely communicate with sellers about the products they want to buy. On the contrary, consumers in an EC environment might find it difficult to deal with the inherent nature of virtuality in their interaction, especially in a poorly designed EC environment where users might be uncomfortable with uncertainty and ambiguity caused by lack of interaction with products and sellers

Chapter 12: You Spin Me Right Round (Like a Record) — Or, Does the Assessment Loop Ever Truly “Close”?

Chapter 12 from Shaping the Campus Conversation on Student Learning and Experience: Activating the Results of Assessment in Action

Collaborative Assessment of Student Learning: A Tale of Two Departments

In Spring 2016, Healey Library and the English department at UMass Boston assessed the impact of library research instruction (LRI) on student learning in ENGL 102. 320 students in 24 sections received LRI. To measure this, booklets the students completed in class were evaluated with a rubric and a post-test was administered at the end of the semester. LRI has a measurable impact on student learning, and students retained and transferred what they learned

Using Bacterial Nanocellulose as a Plasmonic Biosensor

From the Washington University Office of Undergraduate Research Digest (WUURD), Vol. 12, 05-01-2017. Published by the Office of Undergraduate Research. Joy Zalis Kiefer, Director of Undergraduate Research and Associate Dean in the College of Arts & Sciences; Lindsey Paunovich, Editor; Helen Human, Programs Manager and Assistant Dean in the College of Arts and Sciences Mentor: Srikanth Sinamenen

Structural Metamorphosis

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Intelligent Electronic Facilitator: Increasing GDSS Effectiveness and Making Web-Based GDSS Possible

Facilitation is considered one of the most critical factors in the successful use of group decision support systems (GDSS). Human facilitation is constrained by cost, availability, and consistency. These constraints are magnified when GDSS is implemented over the World Wide Web. In this paper, we explore the limitations of reliance solely on the human facilitation and propose the intelligent electronic facilitator (IEF) for supporting human facilitators. We hypothesize that a GDSS augmented with the IEF will improve the process and outcome of GDSS use. We develop an IEF prototype, and use it to test the validity of our hypothesis

Factors Affecting Volunteer Participants\u27 Performance in the Virtual Community: The Case of Knowledge Sharing Website

Virtual community has gained much attention from academia and practice due to its great outcomes and potentials. One of the major issues here is how the virtual communities made such enormous outcomes with little control and reward, as wikipedia or Linux did. This study assumes that the voluntary participant’s performance has a direct impact on the productivity of the virtual community, and tries to find factors affecting the participant’s performance in the virtual community. We employ as theoretical bases Expectancy Theory, Goal Setting Theory, and literatures related with volunteers’ motivation. This study conducts the email survey from participants of knowledge service community of NHN, a leading Korean online company. We find that high-performing participants have individual ability, goal congruence, and the greater level of effort motivated by personal or collective functions