The Synthesis of 2-Indenylphenols: Potential Ligands For Transition Metals

The syntheses of 2-(2-indenyl)-phenol and 2-(1-indenyl)-phenol via a three-step sequence have been developed. In the first steps of the sequence, a Grignard reagent formed from 2-iodoanisole or 2-bromoanisole reacted with 1-indanone or 2-indanone in yields that ranged from 11.3% to 67.2%. The second step consisted of acid-catalyzed dehydration of the alcohol formed in step 1 to make a 2-inenyl anisole; yields in the second step were 45.2% to nearly quantitative. Finally, demethylation of the 2-indenyl anisole was achieved with AlBr3 in ethanethiol in yields ranging from 52.9% to 0 %. Each product was characterized by 1H and 13C NMR. The three products in the series leading to 2-(2-indenyl) phenol were also characterized by elemental analysis. Only the 2-(2-hydroxy-2-indenyl) anisole product was pure

Thermal conductivity of suspended pristine graphene measured by Raman spectroscopy

The thermal conductivity of suspended single-layer graphene was measured as a function of temperature using Raman scattering spectroscopy on clean samples prepared directly on a prepatterned substrate by mechanical exfoliation without chemical treatments. The temperature at the laser spot was monitored by the frequency of the Raman 2$D$ band of the Raman scattering spectrum, and the thermal conductivity was deduced by analyzing heat diffusion equations assuming that the substrate is a heat sink at ambient temperature. The obtained thermal conductivity values range from $\sim$1800 Wm$^{-1}$K$^{-1}$ near 325 K to $\sim$710 Wm$^{-1}$K$^{-1}$ at 500 K.Comment: 4pages, 3 figure

One-dimensional broadband phononic crystal filter with unit cells made of two non-uniform impedance-mirrored elements

A one-dimensional finite-sized phononic crystal(PC) made of a specially-configured unit cell is proposed to realize broad bandpass, high-performance filtering. The unit cell is specially-configured with two elements having mirrored impedance distributions of each other. One element has a non-uniform impedance distribution that is so engineered as to maximize wave transmission in the pass band and to minimize transmission in the adjacent stop band while the other, exactly the mirrored distribution. The mirroring approach naturally yields the overall impedance contrast within the resulting unit cell, necessary to form stop bands in a PC of the unit cells. More importantly, the good transmission performance of the orginally-engineered element can be preserved by the approach because no additional impedance mismatch is introduced along the interface of the two impedance-mirrored elements. Extraordinary performance of the PC filter made of the proposed unit cell, such as high transmission, large bandwidth and sharp roll-off, is demonstrated by using one-dimensional longitudinal elastic wave problems. Copyright 2013 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4790638ope

MOBICORS-Movie: A MOBIle COntents Recommender System for Movie

In spite of the rapid growth of mobile multimedia contents market, most of the customers experience inconvenience, lengthy search processes and frustration in searching for the specific multimedia contents they want. These difficulties are attributable to the current mobile Internet service method based on inefficient sequential search. To overcome these difficulties, this paper proposes a MOBIle COntents Recommender System for Movie (MOBICORS-Movie), which is designed to reduce customers’ search efforts in finding desired movies on the mobile Internet. MOBICORS-Movie consists of three agents: CF (Collaborative Filtering), CBIR (Content-Based Information Retrieval) and RF (Relevance Feedback). These agents collaborate each other to support a customer in finding a desired movie by generating personalized recommendations of movies. To verify the performance of MOBICORS-Movie, the simulation-based experiments were conducted. The experiment results show that MOBICORS-Movie significantly reduces the customer’s search effort and can be a realistic solution for movie recommendation in the mobile Internet environment

Lightweight Concrete Produced Using a Two-Stage Casting Process

The type of lightweight aggregate and its volume fraction in a mix determine the density of lightweight concrete. Minimizing the density obviously requires a higher volume fraction, but this usually causes aggregates segregation in a conventional mixing process. This paper proposes a two-stage casting process to produce a lightweight concrete. This process involves placing lightweight aggregates in a frame and then filling in the remaining interstitial voids with cementitious grout. The casting process results in the lowest density of lightweight concrete, which consequently has low compressive strength. The irregularly shaped aggregates compensate for the weak point in terms of strength while the round-shape aggregates provide a strength of 20 MPa. Therefore, the proposed casting process can be applied for manufacturing non-structural elements and structural composites requiring a very low density and a strength of at most 20 MPaopen0

Exploring Factors That Influence Students’ Behaviors in Information Security

Due to the ever-increasing use of the Internet, information security has become a critical issue in society. This is especially the case for young adults who have different attitudes towards information security practices. In this research, we examine factors that motivate college students’ information security behaviors. Based on the concept of fear arousal in the presence of a threatened event, a well-founded theory known as Protection Motivation Theory (PMT) is adopted in the research model. Social norms and habit factors are integrated to the model as a means to assess students’ behaviors of information security. A survey of 202 responses is used to test the designed model using structural equation modeling to analyze relationships among variables. Results indicated that students are very motivated to practice information security if they perceive high levels of severity, response efficacy, response costs and self-efficacy. Their intentions, however, are not affected by perceived vulnerability or by social influence. Our findings suggest that PMT is a valuable model for predicting students’ attitudes towards information security and that their motivation is influenced by education in security awareness and understanding severity of such issues