In this study, graphene was rapidly grown by chemical vapor deposition using a liquid cell for supplying methanol as a carbon source of graphene. To realize the rapid growth, methanol which is carbon-contained organic solvent was used instead of methane gas, a widely used carbon source for graphene growth. The graphene grown with the growth time as a variable was transferred to a SiO2/ Si substrate with an oxide thickness of 300 nm to confirm whether it was grown with full coverage with an optical microscope. The results confirmed a full coverage in 0.5 min of growth. The Raman spectra also confirmed the G-peak position at 1585.0 cm−1 and an intensity ratio of 2D/G at 2.3 or higher. Concerning electrical transport characteristics, at an induced carrier density of 1 × 1012 cm−2, the hole (μh) and electron (μe) mobilities were 1524 cm2 V−1 s−1 and 1528 cm2 V−1 s−1, respectively. Thus, our study confirmed that high-quality, large-area graphene can be grown within 0.5 min.

The refrigerant temperature of a compressor increases due to heat generated in the discharge chamber and the motor. The increase of the suction temperature raises the superheat resulting in EER reduction. Thus, accurate superheat prediction is needed for the design of an efficient compressor. In this paper, the unsteady flow analysis is performed using CFD to predict the superheat. The results show that the suction temperature increases by about 26 °C which agrees well with the experiments.

In recent years, technology has been developed the way the volume of the portable communication device is reduced but its performance is maintained. The COF(Chip On Film) packaging method is used due to the densification of the lead pitch, especially for the display driver IC. During COF packaging, lead break and film detachment could occur by the high bonding temperature and pressure, and possibility for lead interference can emerge by deformation of leads. In this study, a new double-column arrangement of leads is considered to increase lead density further than the existing zigzag arrangement of leads, and nonlinear structural analysis was carried out to examine whether the interference can occur. The results showed that stress and deformation of the corner region appear relatively higher than those of central region, and interference did not occur by the lead strain for the double-column arrangement of leads with pitch of 25μm. Therefore, double-column lead arrangement can improve lead density by about 176% compared to the zigzag lead arrangement

Abstract The cascade refrigeration cycle system has been used mainly to obtain the ultra-low temperature. In this study, the effects of internal and outdoor temperatures at chamber on the heat capacity of fin-tube heat exchangers were examined. In addition, refrigerant line patterns as well as refrigerant type for cascade cycle were optimized. The results in this study show that the refrigerant line patterns have greater effect on the sensible capacity than the total capacity. Also, the condenser heat release rate for R717-R744 cycle varies the ratio of 46 % with outdoor temperature by comparing with that of 24% for R134a-R410a cycle.

Sialolith is a common disease of salivary glands characterized by the development of salivary stones, resulting in the salivary ductal obstruction. The chief complaints of patients with sialoliths are pain and swelling of the involved gland during meals. Most sialoliths are found in the submandibular gland of middle-aged patients. The size of the salivary stones can vary, but most of them are less than 10mm in size, giant sialoliths(larger than 15mm) are very rare. In this case, we report a 68-years old female patient who had removal of a giant sialolith located in left proximal Wharton’s duct by less invasive intraoral surgical technique successfully. We also review related literature.

A Mixed tumor is a tumor that derives from multiple tissue types. This lesion appears to be mostly Mixed Radiolucent and Radiopaque aspect and typical examples are odontoma, ameloblastic fibroodontoma, ameloblastic fibroma etc. A odontogenic tumor is a neoplasm of the cells or tissues that initiate Odontogenic processes. Typical example is a odontoma. The odontoma is a hamartoma of odontogenic origin. There are two types: compound and complex. A compound odontoma still has the three separate dental tissues (enamel, dentin and cementum), but may present a lobulated appearance where there is no definitive demarcation of separate tissues between the individual "toothlets". It usually appears in the anterior maxilla. The complex type is unrecognizable as dental tissues, usually presenting as a radioopaque area with varying densities. It usually appears in the posterior maxilla or in the mandible. We reported 20-years old male patient who had an atypical mixed radiolucent and radiopaque lesion on right mandibule body tentative diagnosed as complex odontoma and excised.

This infection includes an allergic bronchial reaction, an aspergilloma, and an invasive aspergillosis, which is more common in immunosuppressed patients and presents as multiorgan disease. The maxillary sinus is a relatively common site for formation of an aspergilloma where it forms around a nexus of foreign body. It has been indicated that the foreign body containing zinc extruded into the maxillary sinus has the potential to become infected and form an aspergilloma. The treatment of this disease is radical surgery and adjunctive systemic antifungal therapy. This is a case report of solitary aspergillosis of the right maxillary sinus. We experienced a case of right maxillary sinus aspergillosis in a 37 years old male who has dull pain on right temporal and zygoma area. We reported a case with review of literature

Benign fibrous histiocytomas that is also known as
Dermatofibroma,
Fibrous dermatofibroma, and
Fibrous histiocytoma are benign skin growths. They are composed of disordered collagen laid down by fibroblasts. In rare cases, basal cell carcinoma may develop in that. Benign fibrous histiocytomas of bone are unusual neoplasms that often are confused with metaphyseal fibrous defects. It is an uncommon neoplasm of the Head and Neck region. It is a rare and usually painless oral tumor. Several cases were reported in mandible, but few in maxilla, especially in maxillary gingiva. We are reporting a case of Maxillay gingival.

Plasma cell myeloma is malignant disease of plasma cell in the bone marrow. Myeloma accounts for about 1% of all cancers. The solitary plasma cellmyeloma is rare tumors and account for less than 10% of plasma cell neoplasm. It is often progress to multiple myeloma at 30~40% despite successful local treatment with surgery and radiation therapy. We are reporting a case of solitary plasma cell myeloma on anterior Maxillary region that developed after kidney transplantation and immunosuppressive therapy.

Heck coupling 반응을 이용해서 poly{2-[2-(2,5-bis-dodecyloxy-4-propenyl-phenyl)-vinyl]- 7-methyl-fluoren-9-one(PFone), poly{2-[2-(2,5-bis-dodecyloxy-4-propenyl-phenyl)-vinyl]-7-methyl-fluoren-9-ylidene}-malonitrile(PF2CN)을 합성하였다. 합성한 중합체의 광학적, 전기화학적 특성을 흡수, 형광분광법 및 cyclic voltammetry(CV)를 통해 확인하였다. PFone과 PF2CN 필름의 흡수 극대치는 410 nm과 410.5 nm에서 나타났다. PFone 및 PF2CN의 최대 발광파장은 각각 633과 635nm로 나타났다. PFone과 PF2CN의 band gap은 각각 2.06eV 과 2.36eV이고 CV를 통해 측정한 LUMO 에너지 준위는 -3.36eV 와 -3.46eV로 나타났다.

PAQ(poly-2-[2-(2,5-Bis-dodecyloxy-4-vinyl-phenyl)-vinyl]-anthraquinone)과 PAN4CN(poly- 2-{2-[2-(2,5-Bis-dodecyloxy-4-vinyl-phenyl)vinyl]-10-dicyanomethylene-10H-anthracen-9-ylidene}-malononitrile)을 Heck coupling reaction을 이용하여 합성하였다. 합성한 중합체의 전기적, 광학적 특성은 UV-visible spectra, photoluminescence (PL) spectra 및 cyclic voltammetry 측정을 통해 확인하였다. 흡수 스펙트라 측정 결과, thin film에서의 흡수극대치는 PAQ 와 PAN4CN은 334nm에서 나타났고, 용액에서는 PAQ 338nm, PAN4CN은 336nm 나타났다. 발광 극대치의 측정결과 PAQ는 thin film에서 420nm와 용액상에서는 416nm, PAN4CN은 thin film에서 395nm와 용액에서는 550nm로 각각 나타났다. PAQ과 PAN4CN의 band gap은 각각 2.16 eV, 2.04 eV이고 CV를 통해 LUMO 준위는 -3.64eV, -3.52eV로 나타났다.