Microencapsulation of imidazole curing agent by solvent evaporation method using W/O/W emulsion

The epoxy–imidazole resin system is used to form the anisotropic conducting film. The latent character of the system is very significant. In this study, imidazole (Im) or 2‐methylimidazole (2MI) was encapsulated for the latent curing system to use in the reaction of epoxy resin. Polycaprolactone was used as a wall material, and the solvent evaporation method was used to form the microcapsule using W/O/W emulsion. The shelf life of the microcapsules was studied for the epoxy resin, and the curing behavior of the microcapsules for epoxy resin was examined using a differential scanning calorimeter. The curing times at 150 and 180°C were estimated using an indentation method. The microcapsules of Im or 2MI exhibited a long shelf life for epoxy resin. When comparing the results of the previous methods with the results of this study using the W/O/W emulsion, finer microcapsules were formed and the microcapsule has longer shelf life. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98341/1/38767_ftp.pd

Delayed appendectomy versus early appendectomy in the treatment of acute appendicitis: a retrospective study

BACKGROUND: The controversy still exists about the timing of operation for appendicitis. The aim of this study was to compare the outcomes between early appendectomy and delayed appendectomy and assess the feasibility of delayed operation. METHODS: The medical records of patients with acute appendicitis who received operation between January 1, 2011 and December 31, 2011, were retrospectively reviewed. Outcome measures were white blood cell (WBC) count at postoperative first day, time to soft diet, complication rate, surgical site infection (SSI) rate, length of hospital stay, and readmission within 30 days. RESULTS: During the study period, a total of 478 patients underwent appendectomies, and 145 patients were excluded, leaving 333 who met inclusion criteria. Based on the time from arrival at hospital to incision, they were divided into two groups: 177 (53.2%) in group A and 156 (46.8%) in group B. There were no significant differences in preoperative demographics and clinical data between two groups. The mean WBC count at postoperative first day of group B were lower than that of group A (p = 0.0039). There were no significant differences in time to soft diet, length of postoperative hospital stay, complication rate, and readmission rate between two groups. SSI including intra-abdominal abscess was also shown no significant difference (Group A, 1.7% and Group B, 3.9%; p = 0.3143). CONCLUSIONS: This study revealed that delayed appendectomy was safe and feasible for adult patient although the clinical outcomes of delayed appendectomy were not superior to those of early appendectomy. We suggest that surgeons would decide the appropriate timing of appendectomy with consideration other situations such as available hospital resources

Wire Grid Polarizer by Angled Evaporation Method Using Nanoimprint Lithography.

I report the development of a nanoimprint-lithography-based method of fabricating a wire grid polarizer (WGP), which greatly relaxes patterning and etching requirements and can be easily applied to produce flexible WGPs. Nanoimprinting is a simple and cheap large-area nanofabrication process. To date, WGPs were fabricated by electron beam lithography. Although electron beam lithography has a high resolution and good profile, it is slow and expensive. Therefore, electron beam lithography is not suitable for large-area nanofabrication. To fabricate larger WGPs, nanoimprinting lithography is one of the best processes. WGP resolution and material brittleness have somewhat limited the choice of previous resists used for nanoimprinting. Hence, I developed an epoxy resist whose physical properties were tuned by adjusting the ratio of bisphenol F-type to acrylonitrile-butadiene rubber (NBR)-based epoxy resins in the resist formulation. The mechanical properties of the resist were tuned to obtain various aspect ratios and mold flexibility for conformal contact over nonplanar surfaces and large areas. Roll-to-roll nanoimprint lithography is a very attractive method of manufacturing micro- and nanopatterns owing to its large-area patterning capabilities. Material flexibility is one of the most important requirements in roll-to-roll nanoimprint lithography. Commercially available bisphenol F-type epoxy resin is much less expensive than other resins, so it is a widely used construction polymer. NBR rubber is also widely used. Hence, the resist formulation I developed could be used to industrially mass-produce nanostructures. In addition, I used atomic layer deposition to fabricate 20-nm-linewidth, 9:1-aspect-ratio ultrasmall nanostructures. I used nanoimprint lithography to pattern a high-aspect-ratio, narrow-linewidth grating and subsequently deposited two aluminum layers angled in opposite directions to efficiently fabricate the large-area WGP. Anisotropic reactive-ion etching was used to remove the aluminum layer deposited on top of the grating while retaining that on the grating sidewalls, thereby forming a metal wire grid whose spacings were much smaller than those of a lithographically defined grating. The WGP showed good optical properties in the visible range. I encapsulated the WGP in a thin layer of poly(methyl methacrylate) (PMMA) for practical use, and the encapsulated WGP worked well in the visible range.PHDMacromolecular Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107272/1/youshi_1.pd

Preventing State-Led Cyberattacks Using the Bright Internet and Internet Peace Principles

The Internet has engendered serious cybersecurity problems due to its anonymity, transnationality, and technical shortcomings. This paper addresses state-led cyberattacks (SLCAs) as a particular source of threats. Recently, the concept of the Bright Internet was proposed as a means of shifting the cybersecurity paradigm from self-defensive protection to the preventive identification of malevolent origins through adopting five cohesive principles. To design a preventive solution against SLCAs, we distinguish the nature of SLCAs from that of private-led cyberattacks (PLCAs). We then analyze what can and cannot be prevented according to the principles of the Bright Internet. For this research, we collected seven typical SLCA cases and selected three illustrative PLCA cases with eleven factors. Our analysis demonstrated that Bright Internet principles alone are insufficient for preventing threats from the cyberterror of noncompliant countries. Thus, we propose a complementary measure referred to here as the Internet Peace Principles, which define that the Internet should be used only for peaceful purposes in accordance with international laws and norms. We derive these principles using an approach that combines the extension of physical conventions to cyberspace, the expansion of international cybersecurity conventions to global member countries, and analogical international norms. Based on this framework, we adopt the Charter of the United Nations, the Responsibility of States for Internationally Wrongful Acts, Recommendations by the United Nations Group of Governmental Experts, the Tallinn Manual, and Treaty of the Non-Proliferation of Nuclear Weapons, and others as reference norms that we use to derive the consistent international order embodied by the Internet Peace Principles

Youth Smoking, Cigarette Prices, and Anti-Smoking Sentiment

In this paper, we develop a new direct measure of state anti-smoking sentiment and merge it with micro data on youth smoking in 1992 and 2000. The empirical results from the cross-sectional models show two consistent patterns: after controlling for differences in state anti-smoking sentiment, the price of cigarettes has a weak and statistically insignificant influence on smoking participation; and state anti-smoking sentiment appears to be a potentially important influence on youth smoking participation. The cross-sectional results are corroborated by results from discrete time hazard models of smoking initiation that include state fixed effects. However, there is evidence of price-responsiveness in the conditional cigarette demand by youth and young adult smokers.

Fall Detection Using FMCW Radar to Reduce Detection Errors for the Elderly

Fall accidents pose a significant threat of severe injuries for the elderly, who often need immediate assistance when they fall. Since the use of conventional contact sensors or cameras might be uncomfortable for the user, research on fall detection using non-contact sensors has received considerable attention. While most prior studies have relied heavily on Doppler-based velocity parameters to detect falls, using only Doppler information may lead to erroneous detection of fall-like behavior. As a result, a feature that accounts for additional information is necessary. Addressing this need, this study developed an algorithm for classifying falls by detecting human motions using frequency modulation continuous wave radar, proposing a novel feature to reduce detection errors. The suggested feature was computed using the range-velocity map of the 2D Fourier transform and evaluated using supervised machine learning techniques, such as support vector machine and linear discriminant analysis, attaining an accuracy higher than 91%

Scutellinia (Pezizales) In Korea, With A New Species and Eight New Records

Eleven species of the genus Scutellinia (Pyronemataceae, Pezizales) are recognized in Korea by analysis of macro- and micro-morphological characteristics, substrates and geographical distributions. Eight species are recorded new to Korea, namely, S. ahmadiopsis, S. badio-berbis, S. colensoi, S. jilinensis, S. nigrohirtula, S. olivascens, S. setosa and S. patagonica. Based on the exceptional length of marginal hairs and tuberculate ascospore wall ornamentation, two Korean specimens occurring on wood are described as a new species. Infraspecific morphological variations among collections within S. scutellata and S. patagonica were found. These are tentative treat as species complexes. The highly questionable occurrence of S. setosa in Asia was confirmed. Descriptions and taxonomic notes of the recognized species of Scutellinia are provided with a taxonomic key, illustrations and photographs of these species from Korea.Organismic and Evolutionary Biolog

Rheological method for alpha test evaluation of developing superplasticizers' performance: Channel flow test

Advance in high-range water-reducing admixture revolutionizes the workability and constructability of conventional vibrated concrete as well as self-consolidating concrete. Its need from construction fields has increased, and consequently a variety of new-type polycarboxylates, base polymers for the admixture, are being formulated in these days. Synthesizing new polymers needs a quick, but reliable, test to evaluate its performance on concrete. The test is also asked for selecting the best applicable brand of them before a test concrete will be mixed. This paper proposes a channel flow test and its usage for the purpose. The proposed procedure for the test includes the mix proportion of a test mortar, the test method, and rheological interpretation of the test results.ope