• Bulletin of the Korean Chemical Society
• /
• 제34권10호
• /
• pp.3059-3064
• /
• 2013

In this study transesterification of Triglycerides (TG) from Jatropha curcas oil (JCO) with methanol for production of biodiesel was investigated over cerium impregnated ZSM-5 catalysts. NaZSM-5 was synthesized in an alkaline medium and impregnated with cerium oxide by wet method using cerium nitrate as a source for cerium. They were characterized by X-ray diffraction (XRD), Thermogravimeteric analysis (TGA), $CO_2$-temperature programmed desorption, and $N_2$ adsorption/desorption analysis. XRD analysis showed decrease in intensity of the patterns with the increase in the ceria loading but crystallization of ceria to larger size is an evident for 10 and 15% loading. The optimal yield of transesterification process was found to be 90% under the following conditions: oil to methanol molar ratio: 1:12; temperature: $60^{\circ}C$; time: 1 h; catalyst: 5 wt %. Here the yield of fatty acid methyl ester (FAME) was calculated through $^1H$ NMR analysis. The investigation on catalyst loading, temperature, time and reusability illustrated that these ceria impregnated NaZSM-5's were found to be selective, recyclable and could yield biodiesel at low temperature with low methanol to oil ratio due to the presence of both Lewis and Bronsted basicity. Hence, from the above study it is concluded that ceria impregnated ZSM-5 could be recognized as a potential catalysts for biodiesel production in industrial processes.

• 국제물리치료학회지
• /
• 제8권1호
• /
• pp.1122-1127
• /
• 2017

The purpose of this case study was to identify the effects of posteroanterior (PA) mobilization on the cervical spine in a patient with chronic whiplash-associated disorder (WAD). The subject of this study was a 58-year-old woman who sustained a chronic WAD as a result of a motor vehicle accident two years prior. The subject has progressively worsening neck pain and stiffness. The subject was determined to have a grade IIb WAD the use of the Modified Quebec Classification. The intervention was central and unilateral PA mobilization on the spinous process of C4 and C5. The PA mobilizations were performed at the end of range to Maitland grade IV. The PA mobilization was conducted once daily for a total of eight days. Two sets of measurements were done one before and one after the intervention. Neck pain, cervical stiffness, range of motion and lordosis of the cervical spine were measured. Experimental intervention decreased the neck pain, and increased the neck stiffness and cervical ROM (range of motion) such as flexion, extension, lateral flexion and rotation. X-ray photographs also represented that cervical curvature increased from $35^{\circ}$ to $40^{\circ}$. This study suggested that PA cervical mobilization applied to hronic WAD is effective in decreasing pain, increasing cervical ROM and cervical curvature.

• 천문학회보
• /
• 제39권1호
• /
• pp.37.1-37.1
• /
• 2014

There exists strong evidence supporting the co-evolution of central supermassive black holes and their host galaxies; however it is still under debate how such a relation comes about and whether it is relevant for all or only a subset of galaxies. An important mechanism connecting AGN to their host galaxies is AGN feedback, potentially heating up or even expelling gas from galaxies. AGN feedback may hence be responsible for the eventual quenching of star formation and halting of galaxy growth. A rich multi-wavelength dataset ranging from the X-ray regime (Chandra), to far-IR (Herschel), and radio (WSRT) is available for the North Ecliptic Pole field, most notably surveyed by the AKARI infrared space telescope, covering a total area on the sky of 5.4 sq. degrees. We investigate the star-formation properties and possible signatures of radio feedback mechanisms in the host galaxies of 237 radio-AGN below redshift z=2 and at a radio 1.4 GHz flux density limit of 0.1 mJy. Using broadband SED modeling, the nuclear and host galaxy components of these sources are studied simultaneously as a function of their radio luminosity. Here we present results concerning the AGN content of the radio sources in this field, while offering evidence supporting a "maintenance" type of feedback from powerful radio-jets.

• Bulletin of the Korean Chemical Society
• /
• 제31권12호
• /
• pp.3707-3710
• /
• 2010

A chromo/fluorogenic $NO_2S_2$-macrocycle L functionalized with nitrobenzofurazan unit as a dual-signaling probe was synthesized and structurally characterized by single crystal X-ray analysis. In a cation-induced color change experiment, L exhibited excellent $Hg^{2+}$ ion selectivity by showing the color change from orange-red to yellow. However, this hypochromic shift by $Hg^{2+}$ was observed for the weaker coordinating anion system such as ${NO_3}^-$ and ${ClO_4}^-$ ions. The observed anion effect is due to the strong coordination of anions inhibits the bond formation between $Hg^{2+}$ and the macrocyclic tert-N atom, which is sensitive to induce the color change. In the fluorometric experiment, L showed chelate-enhanced fluorescence change effect only with $Hg^{2+}$ ion, together with a change from yellow to green emission. The sensing ability for $Hg^{2+}$ with the proposed chemosensor L is due to the stable complexation with 1:1 stoichiometry (metal-to-ligand).

• Tuberculosis and Respiratory Diseases
• /
• 제42권6호
• /
• pp.947-950
• /
• 1995

저자 등은 폐결핵에 의한 공동발생으로 오인되었던 원발성 폐선암 1예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• 한국재료학회지
• /
• 제12권5호
• /
• pp.359-362
• /
• 2002

DBPAS has been used to characterize atomic level defect structures in materials. In this investigation the numerical analysis of the Doppler spectra was restricted to the determination of the shape parameter, S, defined as the ratio between the total amount of counts in a central portion of the spectrum and the total amount of counts. As samples were exposed by X-ray increasing from 3, 6, and 9 Gy with 6 MV, and 10 MV each and also by E-beam increasing the energies with 6 MeV, 9 MeV, 12 MeV, and 20 MeV. The S-parameter values were increased as increasing the exposed time and the energies. The S-parameters of the large and small size grains in $CaWO_4$ were measured. The S-parameter of the small size grains in $CaWO_4$ was resulted in larger values.

• Journal of Korean Neurosurgical Society
• /
• 제30권sup1호
• /
• pp.124-127
• /
• 2001

Langerhans' cell histiocytosis is a rare disease showing proliferation of histiocytes in multiple organ system. Bone lesions are the most common radiolologic manifestation of Langerhans' cell hysticytosis. Extraskeletal sites of Langerhans' cell hystiocytosis involvement include the skin, lymph nodes, thymus, lungs, central nervous system, liver, pancrease, spleen, and bowel. The authors have experienced a case of Langerhans' cell histiocytosis which involved the skull. A 3-year-old female presented with soft tissue mass on right periorbital area. Plain skull X-ray showed punched out bone lesion. Computed tomography showed non-enhancing osteolytic lesion on right frontal skull. Histologic findings of an excised mass revealed pathologic features of Langerhans' cell histiocytosis.

• Environmental Engineering Research
• /
• 제24권1호
• /
• pp.24-30
• /
• 2019

The present study explores the applicability of response surface methodology (RSM) in conjunction with central composite design (CCD) matrix to statistically optimize ettringite crystallization process for the removal of sulphate from landfill leachate. A three factor-five coded level CCD with 20 runs, was performed to estimate the best fitted model. The RSM results indicated that the fitted quadratic regression model could be appropriate to predict sulfate removal efficiency. The pH was identified as the most dominant parameter affecting sulphate removal. 61.6% of maximum sulphate removal efficiency was obtained at pH of 11.06 for a 1.87 of $Ca/SO_4$ and 0.51 of $Al/SO_4$ molar ratios. The operating cost for ettringite crystallization at optimized conditions was calculated to be 0.52 $/$m^3$. The significance of independent variables and their interactions were tested by analysis of variance. Scanning electron microscope (SEM) and SEM coupled with energy dispersive X-Ray spectroscopy results confirmed the formation of ettringite crystal and were used to describe its morphology features.

• 대한금속재료학회지
• /
• 제49권1호
• /
• pp.52-57
• /
• 2011

Nickel ferrite ($NiFe_2O_4$) powder was prepared through the ceramic route by calcination of a stoichiometric mixture of nickel oxide (NiO) and iron oxide ($Fe_2O_3$). The pressed pellets of $NiFe_2O_4$ were isothermally reduced in pure hydrogen at 800, 900, 1000 and $1100^{\circ}C$. Based on thermogravimetric analysis, the reduction behavior and the kinetic reaction mechanisms of the synthesized ferrite were studied. The initial ferrite powder and various reduction products were characterized by XRD, SEM, reflected light microscope and VSM to reveal the effect of hydrogen reduction on the composition, microstructure, magnetic properties and reaction kinetics of the produced Fe-Ni alloy. Complete reduction of the $NiFe_2O_4$ was achieved with synthesis of homogeneous nanocrystalline Fe-Ni alloys. Arrhenius equation with the approved mathematical formulations for a gas-solid reaction was applied for calculating the activation energy ($E_a$) values and detecting the controlling reaction mechanism.

• Imaging Science in Dentistry
• /
• 제53권2호
• /
• pp.161-168
• /
• 2023

Nasopalatine duct cysts (NPDCs), the most common non-odontogenic cysts of maxilla, are often incidental findings on diagnostic imaging. When symptomatic, they usually present as a painless swelling with possible fistula. Conventional radiography shows a round-to-ovoid or heart-shaped radiolucency between the roots of central maxillary incisors. While the radiographic features of NPDCs in X-ray-based modalities have been well described, their magnetic resonance imaging (MRI) features have rarely been reported. Developments in dental MRI in recent years and the introduction of various dental MRI protocols now allow a wide range of applications in dental medicine. MRI is becoming an important tool for the detection and diagnosis of incidental or non-incidental dentomaxillofacial cysts. This report presented and discussed the characteristics of 2 NPDC cases visualized on MRI using both conventional and newly implemented specific dental MRI protocols with a novel 15-channel mandibular coil, demonstrating the use of these protocols for radiation-free maxillofacial diagnoses.