Recent Advances in Unconventional Lithography for Challenging 3D Hierarchical Structures and Their Applications

In nanoscience and nanotechnology, nanofabrication is critical. Among the required processes for nanofabrication, lithography is one of core issues. Although conventional photolithography with recent remarkable improvement has contributed to the industry during the past few decades, fabrication of 3-dimensional (3D) nanostructure is still challenging. In this review, we summarize recent advances for the construction of 3D nanostructures by unconventional lithography and the combination of two top-down approaches or top-down and bottom-up approaches. We believe that the 3D hierarchical nanostructures described here will have a broad range of applications having adaptable levels of functional integration of precisely controlled nanoarchitectures that are required by not only academia, but also industry

The Light and Period Variations of the Eclipsing Binary AA Ursae Majoris

We present new multiband CCD photometry for AA UMa made on 8 nights between January and March 2009; the $R$ light curves are the first ever compiled. Historical light curves, as well as ours, display partial eclipses and inverse O'Connell effects with Max I fainter than Max II. Among possible spot models, a cool spot on either of the component stars and its variability with time permit good light-curve representations for the system. A total of 194 eclipse timings over 81 yrs, including our five timings, were used for ephemeris computations. We found that the orbital period of the system has varied due to a periodic oscillation overlaid on an upward parabolic variation. The continuous period increase at a fractional rate of $+$1.3$\times$10$^{-10}$ is consistent with that calculated from the W-D code and can be interpreted as a thermal mass transfer from the less to the more massive secondary star at a rate of 6.6$\times$10$^{-8}$ M$_\odot$ yr$^{-1}$. The periodic component is in satisfactory accord with a light-time effect due to an unseen companion with a period of 28.2 yrs, a semi-amplitude of 0.007 d, and a minimum mass of $M_3 \sin i_3$=0.25 $M_\odot$ but this period variation could also arise from magnetic activity.Comment: 23 pages, including 5 figures and 8 tables, accepted for publication in PAS

Fabrication and Evaluation of Mechanical Properties of CF/GNP Composites

AbstractCNT/CFRP (Carbon Nanotube/ Carbon Fiber Reinforced Plastic) composites and GNP/CFRP (Graphene Nano platelet/ Carbon Fiber Reinforced Plastic) have several excellent mechanical properties including, high strength, young's modulus, thermal conductivity, corrosion resistance, electronic shielding and so on. In this study, CNT/CFRP composites were manufactured by varying the CNT weight ratio as 2wt% and 3wt%, While GNP/CFRP composites were manufactured by varying the GNP weight ratio as 0.5wt% and 1wt%. The composites ware manufactured by mechanical method (3-roll-mill). Tensile, impact and wear tests were performed according to ASTM standards D638, D256 and D3181 respectively. It was observed that, increasing the CNT weight ratio improves the mechanical properties, e.g., tensile strength, impact and wear resistance

Epileptic nystagmus: A case report and systematic review

AbstractPurposeWe aimed to define the characteristics of epileptic nystagmus and correlate those with other clinical findings in a large number of patients.MethodsWe report a patient with epileptic nystagmus and additionally reviewed the reported clinical features of 36 more patients through a systematic literature search. We analyzed the characteristics of epileptic nystagmus and attempted correlations of those with alertness of the patients and epileptic foci on EEG.ResultsAll 33 patients with unilateral horizontal nystagmus showed nystagmus beating away from the side of ictal discharges. Epileptic nystagmus was preceded by gaze deviation in 21 patients, with contraversive in 19 and ipsiversive in 2. Seizures associated with epileptic nystagmus were mostly focal (25/29, 86.2%) with or without loss of awareness. Ictal discharges originated from the occipital (n=16), parietal (n=9), temporo-occipital (n=6), frontal (n=4), and temporal (n=3) areas, and two patients had multiple epileptic foci. Seizures were usually symptomatic (24/37, 64.9%). The presence of preceding gaze deviation and midline crossing of the nystagmus did not correlate with the ictal onset zone or alertness of the patients. Recording of epileptic nystagmus was available only in 6 patients, and the epileptic nystagmus could be localized to the saccadic areas in two and to the smooth pursuit areas in another two. Two patients showed the features of epileptic nystagmus from both areas.ConclusionEven though the localizing value of epileptic nystagmus seems limited in previous reports, the fast phase of epileptic nystagmus was almost always directed away from the epileptic focus that mostly arose from the posterior part of the cerebral hemisphere

Far-Ultraviolet Cooling Features of the Antlia Supernova Remnant

We present far-ultraviolet observations of the Antlia supernova remnant obtained with Far-ultraviolet IMaging Spectrograph (FIMS, also called SPEAR). The strongest lines observed are C IV 1548,1551 and C III 977. The C IV emission of this mixed-morphology supernova remnant shows a clumpy distribution, and the line intensity is nearly constant with radius. The C III 977 line, though too weak to be mapped over the whole remnant, is shown to vary radially. The line intensity peaks at about half the radius, and drops at the edge of the remnant. Both the clumpy distribution of C IV and the rise in the C IV to C III ratio towards the edge suggest that central emission is from evaporating cloudlets rather than thermal conduction in a more uniform, dense medium.Comment: 9 pages, 4 figures, will be published in ApJ December 1, 2007, v670n2 issue. see http://astro.snu.ac.kr/~jhshinn/ms.pd

The Significance of DNA Ploidy by Flow Cytometric Measurement in Pancreatic Cancer

The cellular DNA content of pancreatic cancer using formalin-fixed, paraffin-embedded specimens from 37 patients whose disease had been treated with surgical resection was determined by flow cytometry. Ploidy and cell cycle parameters were analysed and correlated with clinical and pathologic findings. There were 24 (64. 9%) diploid and 13 non-diploid pancreatic cancers. The median survival of the patients with diploid tumor was 14 months and that of the patients with non-diploid tumor was 8 months, but the difference did not have statistical significance (p=O. 078). And other cytometric parameters such as Gl phase fraction (p=O. 84), S phase fraction (0. 076), G2M phase fraction (p=O. 72), and proliferative index (p=O. 81) did not show any significant prognostic value. The patients with stage I (n=15) had 27 months of median survival, the patients with stage II (n=8) 7 months of median survival, the patients with stage III (n> 15) 9 months of median survival. The differences of survival by stage were the most significant among the parameters which were studied (p=O. 0003). The group which had lymph node metastasis (n> 11) showed 7 months of median survival and the group with negative lymph node (n=26) 12 months. The difference was also significant (p=O. 046). The other clinical parameters such as sex, the size of tumor, and the location of tumor did not have any influence on the prognosis of the pancreatic cancer patients in this study. Multivariate analysis by Weibull's model was used for prediction of survival time. Diploid versus non-diploid DNA content changed to less significant factor after adjustment for stage and lymph node. But the stage of the tumor remained a highly significant prognostic factor even after adjustment for ploidy and lymph node status

Results of Hepatic Resections at S. N. U. H.: A Ten-year Experience

The medical records of 399 patients who underwent hepatic resection between January 1981 and December 1990 were reviewed. Information regarding the results of hepatic resection in terms of operative indication, operative procedure, operative morbidity and mortality, was abstracted. Until the end of 1990, a total of 402 hepatic resections were completed including 319 primary malignancies, 4 secondary malignancies, 2 gallbladder carcinomas, 42 intrahepatic cholelithiasis, 35 benign masses. Major hepatic resections were performed on 117 patients(29%). Of the 117 patients, 60(51%) had histologically proven liver cirrhosis. Minor hepatic resections were performed on 285 patients (71%). Sepsis was the most frequent complication, manifested primarily as wound infection(71 cases) or intra-abdominal infection(25 cases). Nonfatal hepatic failure occured in 9 patients with cirrhosis and 1 patient without cirrhosis. There were 38 operative deaths among 402 hepatic resections, for an overall operative mortality of 9.4 %. Twenty five of these patients died from hepatic failure after operation, accounting for 66 % of the total operative mortality. There has been an increasing frequency of hepatic resection during the last five years. Indications for resection increased from 87 to 195 resections for hepatocellular carcinoma. The cumulative data show a decrease in the complication rate and operative mortality. In the recent period, nonlethal postoperative complications have occured in 135 of 286 patients (47%). The overall survival rates in 172 patients with hepatocellular carcinoma excluding operative mortalities and palliative resections and reresections, were 71.0 %, 39.8%, 28.3% for 1, 3, and 5 years, respectively

Photometric Properties of the Near-contact Binary GW Geminorum

New multiband CCD photometry is presented for the eclipsing binary GW Gem; the $RI$ light curves are the first ever compiled. Four new minimum timings have been determined. Our analysis of eclipse timings observed during the past 79 years indicates a continuous period increase at a fractional rate of +(1.2$\pm$0.1)$\times10^{-10}$, in excellent agreement with the value $+1.1\times10^{-10}$ calculated from the Wilson-Devinney binary code. The new light curves display an inverse O'Connell effect increasing toward longer wavelengths. Hot and cool spot models are developed to describe these variations but we prefer a cool spot on the secondary star. Our light-curve synthesis reveals that GW Gem is in a semi-detached, but near-contact, configuration. It appears to consist of a near-main-sequence primary star with a spectral type of about A7 and an evolved early K-type secondary star that completely fills its inner Roche lobe. Mass transfer from the secondary to the primary component is responsible for the observed secular period change.Comment: 20 pages, including 5 figures and 6 tables, accepted for publication in PAS

Microlensing Detections of Planets in Binary Stellar Systems

We demonstrate that microlensing can be used for detecting planets in binary stellar systems. This is possible because in the geometry of planetary binary systems where the planet orbits one of the binary component and the other binary star is located at a large distance, both planet and secondary companion produce perturbations at a common region around the planet-hosting binary star and thus the signatures of both planet and binary companion can be detected in the light curves of high-magnification lensing events. We find that identifying planets in binary systems is optimized when the secondary is located in a certain range which depends on the type of the planet. The proposed method can detect planets with masses down to one tenth of the Jupiter mass in binaries with separations <~ 100 AU. These ranges of planet mass and binary separation are not covered by other methods and thus microlensing would be able to make the planetary binary sample richer.Comment: 5 pages, two figures in JPG forma