The Eco-School Project at the Daegu National University of Education

Asia Education Symposium 2006, Session 3: “Making the most of Resources of International Education”( Day Two; Sun., October 16

Formation of high-quality Ag-based ohmic contacts to p-type GaN

Low resistance and high reflectance ohmic contacts on p-type GaN were achieved using an Ag-based metallization scheme. Oxidation annealing was the key to achieve ohmic behavior of Ag-based contacts on p-type GaN. A low contact resistivity of similar to 5x10(-5) Omega cm(2) could be achieved from Me (=Ni, Ir, Pt, or Ru)/Ag (50/1200 angstrom) contacts after annealing at 500 degrees C for 1 min in O(2) ambient. Oxidation annealing promoted the out-diffusion of Ga atoms from the GaN layer, and Ga atoms dissolved in the in-diffused Ag layer with the formation of Ag-Ga solid solution, resulting in ohmic contact formation. Using Ru/Ni/Au (500/200/500 angstrom) overlayers on the Me/Ag contacts, the excessive incorporation of oxygen molecules into the contact interfacial region, and the out-diffusion and agglomeration of Ag, were effectively prevented during oxidation annealing. As a result, a high reflectance of 87.2% at the 460 nm wavelength and a smooth surface morphology could be obtained simultaneously. (C) 2008 The Electrochemical Society.open111618sciescopu

The Effects of Creative Experience-Centered Environmental Education on Emotional Intelligence of Elementary School Students

This study was carried out with the purpose of verifying the impact that experience centered environmental education with an emphasis on communing with the surrounding natural environment could have on elementary school student`s emotional intelligence. This experiment was carried out on a group of 55 students (29 in the control and 26 in the experimental group) from two 4th grade classes. Following the development of experience-oriented lessons on environmental education based on a 'teaching and learning' model of environmental education for this study, the lessons were applied for 30 lessons and over a 16-week period. The experiment was carried out using a checklist of emotional intelligence and administered by a pretest-posttest method. The results of the study, signs of improvement were recognized in ability to recognize self-emotion (p〈.05), ability to control self-emotion (p〈.05), interpersonal skills with a significant increase (p〈.01), self-synchronization ability (p=0.183), and empathic ability (p=0.058). Therefore, it is evident that a positive effect on the increase of emotional intelligence in elementary school students is achieved through creative experience-oriented environmental education

Indium as an efficient ohmic contact to N-face n-GaN of GaN-based vertical light-emitting diodes

We propose indium (In), a low work function and nitride-forming element, as an efficient ohmic contact layer to N-face n-GaN. While conventional Al-based ohmic contacts show severe degradation after annealing at 300 C, In-based ohmic contacts display considerable improvement in contact resistivity. The annealing-induced enhancement of ohmic behavior in In-based contacts is attributed to the formation of an InN interfacial layer, which is supported by x-ray photoemission spectroscopy measurements. These results suggest that In is of particular importance for application as reliable ohmic contacts to n-GaN of GaN-based vertical light-emitting diodes.open3

Analysis of speech and tongue motion in normal and post-glossectomy speaker using cine MRI

Objective Since the tongue is the oral structure responsible for mastication, pronunciation, and swallowing functions, patients who undergo glossectomy can be affected in various aspects of these functions. The vowel /i/ uses the tongue shape, whereas /u/ uses tongue and lip shapes. The purpose of this study is to investigate the morphological changes of the tongue and the adaptation of pronunciation using cine MRI for speech of patients who undergo glossectomy. Material and Methods Twenty-three controls (11 males and 12 females) and 13 patients (eight males and five females) volunteered to participate in the experiment. The patients underwent glossectomy surgery for T1 or T2 lateral lingual tumors. The speech tasks “a souk” and “a geese” were spoken by all subjects providing data for the vowels /u/ and /i/. Cine MRI and speech acoustics were recorded and measured to compare the changes in the tongue with vowel acoustics after surgery. 2D measurements were made of the interlip distance, tongue-palate distance, tongue position (anterior-posterior and superior-inferior), tongue height on the left and right sides, and pharynx size. Vowel formants Fl, F2, and F3 were measured. Results The patients had significantly lower F2/Fl ratios (F=5.911, p=0.018), and lower F3/F1 ratios that approached significance. This was seen primarily in the /u/ data. Patients had flatter tongue shapes than controls with a greater effect seen in /u/ than /i/. Conclusion The patients showed complex adaptation motion in order to preserve the acoustic integrity of the vowels, and the tongue modified cavity size relationships to maintain the value of the formant frequencies

Characteristics of the aberrant pyramidal tract in comparison with the pyramidal tract in the human brain

<p>Abstract</p> <p>Background</p> <p>The aberrant pyramidal tract (APT) refers to the collateral pathway of the pyramidal tract (PT) through the medial lemniscus in the midbrain and pons. Using diffusion tensor tractography (DTT), we investigated the characteristics of the APT in comparison with the PT in the normal human brain.</p> <p>Results</p> <p>In thirty-four (18.3%, right hemisphere: 20, left hemisphere: 14) of the 186 hemispheres, the APTs separated from the PT at the upper midbrain level, descended through the medial lemniscus from the midbrain to the pons, and then rejoined with the PT at the upper medulla. Nine (26.5%) of the 34 APTs were found to originate from the primary somatosensory cortex without a primary motor cortex origin. Values of fractional anisotropy (FA) and tract volume of the APT were lower than those of the PT (<it>P </it>< 0.05); however, no difference in mean diffusivity (MD) value was observed (<it>P ></it>0.05).</p> <p>Conclusion</p> <p>We found that the APT has different characteristics, including less directionality, fewer neural fibers, and less origin from the primary motor cortex than the PT.</p

Rocuronium bromide induced anaphylaxis in a child -A case report-

Anaphylaxis or anaphylactoid reaction in pediatric patient during anesthesia is rare. We report a rocuronium induced anaphylactic reaction in a 33-month-old female. The patient was scheduled to undergo escharectomy due to injuries suffered from a major burn. Shortly after administration of rocuronium, the patient developed severe hypotension, tachycardia, and hypoxia. A similar reaction occurred after administration of rocuronium on subsequent anesthesia. She underwent uneventful anesthesia with volatile induction and maintenance of anesthesia with sevoflurane on her next 7 operations without using of muscle relaxant

A Case of Postprandial Hypotension in the Intensive Care Unit Treated With Acarbose

Postprandial hypotension (PPH) has not been described as a cause of hypotension after the return of spontaneous circulation (ROSC) in the intensive care unit (ICU). A 74 year old man underwent cardiopulmonary resuscitation (CPR) due to monomorphic ventricular tachycardia. After the ROSC, inotropic agents were not reduced but increased. PPH had occurred, according to the flow sheet, so a provocation test was performed. We noted hypotension but no serum hypoglycemia or tachycardia. The hypotension was diagnosed as PPH. We chose acarbose for treatment; thus, the inotropic agents were discontinued. This is the first case in which hypotension occurred in a patient recovering after CPR in the ICU and that the PPH was treated with acarbose. PPH should be considered and treated to manage hypotension in elderly patients in the ICU