• Applied Chemistry for Engineering
• /
• v.32 no.3
• /
• pp.299-304
• /
• 2021

This study focuses on the preparation of acetaminophen (AP) imprinted functional biomaterials for a transdermal drug delivery using mung bean starch (MBS), polyvinyl alcohol (PVA), sodium benzoate (S) as a crosslinking agent, glycerol (GL) as a plasticizer, and melanin (MEL) as a photothermal agent. The prepared AP imprinted biomaterials were characterized using FE-SEM and their physical properties were evaluated. The photothermal effect and AP release property for functional biomaterials were examined with the irradiation of near infrared (NIR) laser (1.5 W/cm²). When the NIR laser was irradiated on functional biomaterials with/without the addition of MEL, the temperature of MEL added biomaterial increased from 25 ℃ to 41 ℃, whereas the biomaterial without MEL increased from 25 ℃ to 28 ℃. Results indicate that there is the photothermal effect of prepared biomaterial with the addition of MEL. Based on the results, AP release properties were evaluated using standard buffer solutions and artificial skin. It was found that AP release rates of MEL added AP loaded biomaterials were 1.2 times faster than those of MEL non-added AP loaded biomaterials when irradiating with NIR laser. We envision that the developed functional biomaterials can be utilized for an acute pain-killing treatment.

• Journal of the Korean Chemical Society
• /
• v.33 no.2
• /
• pp.156-163
• /
• 1989

The $ν_a+amide II$ combination band of thiopropionamide has been recorded for investigation of Hydrogen bonding between thiopropionamide (TPA) and N,N-dimethylalkylamide (DMF, DMA and DMP) in carbon tetrachloride over the range of $5^{\circ}$ to $55^{\circ}$. The combination band of monomeric TPA and hydrogen-bonded TPA can be resolved by Lorentzian-Gaussian product function into monomeric TPA and hydrogen-bonded TPA with amides. The association constants ($K_1$) for the hydrogen-bonded TPA were calculated by the concentrations of the monomeric TPA and the hydrogen-bonded TPA obtained from the computer resolved absorption bands. Thermodynamic parameters for the Hydrogen bonding have been evaluated by the analysis of the temperature dependent spectra. The ${\Delta}$$H^{\circ}$ of hydrogen-bonded TPA with DMF, DMA and DMP have been found to be-12.5, -13.5 and -14.1 kJ/mol, respectively. The corresponding ${\Delta}$$S^{\circ}$for the above system were -15.2, -17.9 and -22.3 J/mol${\cdot}$deg, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.9 no.1
• /
• pp.20-22
• /
• 1999

The effect of dopant and stoichiometry on the physical and optical properties of $LiNbO_{3}$ were studied. We prepared three samples, undoped, MgO doped $LiNbO_{3}$ with congruent composition and near-stoichiometric $LiNbO_{3}$. Dielectric constant and transmittance in UV/VIS/IR light range were measured. The results showed that the features for high [Li]/[Nb] were similar to those for low [Li]/[Nb] but with high [Mg].

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.400.1-400.1
• /
• 2016

Interfacial engineering approaches as an efficient strategy for improving the power conversion efficiencies (PCEs) of inverted polymer solar cells (iPSCs) has attracted considerable attention. Recently, polymer surface modifiers, such as poly(ethyleneimine) (PEI) and polyethylenimine ethoxylated (PEIE), were introduced to produce low WF electrodes and were reported to have good electron selectivity for inverted polymer solar cells (iPSCs) without an n-type metal oxide layer. To obtain more efficient solar cells, quantum dots (QDs) are used as effective sensitizers across a broad spectral range from visible to near IR. Additionally, they have the ability to efficiently generate multiple excitons from a single photon via a process called carrier multiplication (CM) or multiple exciton generation (MEG). However, in general, it is very difficult to prepare a bilayer structure with an organic layer and a QD interlayer through a solution process, because most solvents can dissolve and destroy the organic layer and QD interlayer. To present a more effective strategy for surpassing the limitations of traditional methods, we studied and fabricated the highly efficient iPSCs with mono-layered QDs as an effective multi-functional layer, to enhance the quantum yield caused by various effects of QDs monolayer. The mono-layered QDs play the multi-functional role as surface modifier, sub-photosensitizer and electron transport layer. Using this effective approach, we achieve the highest conversion efficiency of ~10.3% resulting from improved interfacial properties and efficient charge transfer, which is verified by various analysis tools.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.157-157
• /
• 2017

To minimize the damage by wild birds and acquire the benefits such as protection against weeds and maintenance of water content in soil, the mulching black color vinyl after seeding should be carried out. Non-contact and non-destructive methods that can continuously determine the locations are necessary. In this study, a crop position detection method was studied that uses infrared thermal image sensor to determine the cotyledon position under vinyl mulch. The moving system for acquiring image arrays has been developed for continuously detecting crop locations under plastic mulching on the field. A sliding mechanical device was developed to move the sensor, which were arranged in the form of a linear array, perpendicular to the array using a micro-controller integrated with a stepping motor. The experiments were conducted while moving 4.00 cm/s speed of the IR sensor by the rotational speed of the stepping motor based on a digital pulse width modulation signal from the micro-controller. The acquired images were calibrated with the spatial image correlation. The collected data were processed using moving averaging on interpolation to determine the frame where the variance was the smallest in resolution units of 1.02 cm. Non-linear integral interpolation was one of method for analyzing the frequency using the normalization image and then arbitrarily increasing the limited data value of $16{\times}4pixels$ in one frame. It was a method to relatively reduce the size of overlapping pixels by arbitrarily increasing the limited data value. The splitted frames into 0.1 units instead of 1 pixel can propose more than 10 times more accurate and original method than the existing correction method. The non-integral calibration method was conducted by applying the subdivision method to the pixels to find the optimal correction resolution based on the first reversed frequency. In order to find a correct resolution, the expected location of the first crop was indicated on near pixel 4 in the inversion frequency. For the most optimized resolution, the pixel was divided by 0.4 pixel instead of one pixel to find out where the lowest frequency exists.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.8 no.2
• /
• pp.128-133
• /
• 2008

Phase-change random access memory (PRAM) chip cell phase of amorphous state is rapidly changed to crystal state above 160 Celsius degree within several seconds during Infrared (IR) reflow. Thus, on-board programming method is considered for PRAM chip programming. We demonstrated the functional 512Mb PRAM with 90nm technology using several novel core circuits, such as metal-2 line based global row decoding scheme, PN-diode cells based BL discharge (BLDIS) scheme, and PMOS switch based column decoding scheme. The reverse-state standby current of each PRAM cell is near 10 pA range. The total leak current of 512Mb PRAM chip in standby mode on discharging state can be more than 5 mA. Thus in the proposed BLDIS control, all bitlines (BLs) are in floating state in standby mode, then in active mode, the activated BLs are discharged to low level in the early timing of the active period by the short pulse BLDIS control timing operation. In the conventional sense amplifier, the simultaneous switching activation timing operation invokes the large coupling noise between the VSAREF node and the inner amplification nodes of the sense amplifiers. The coupling noise at VSAREF degrades the sensing voltage margin of the conventional sense amplifier. The merit of the proposed sense amplifier is almost removing the coupling noise at VSAREF from sharing with other sense amplifiers.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.2
• /
• pp.49.2-49.2
• /
• 2015

Galaxy cluster is the most important laboratoriy to study the effect of environment on galaxies, one of key questions in astronomy. In the local universe, it is well known that red, passive galaxies are concentrated in the cluster core. However, it is still controversial whether the star formation-density relation at the low redshift is retained in the distant universe. Many surveys have tried to find galaxy clusters at various epochs. However the optical dataset has limitations in finding galaxy clusters at z > 1, since the bulk of stellar emission of z > 1 galaxies is redshifted into the near-IR regime. We used the multi-wavelength data from the UKIDSS DXS (J and K bands), the SWIRE (4 IRAC bands), and the PAN-STARRS (g, r, i, z, y bands) and IMS (J band; Im et al. 2015, in preparation) in the European Large Area ISO Survey North1 (ELAIS-N1) field to search for high redshift galaxy clusters and study the properties of member galaxies. Using the multi-wavelength data, we investigated overdensities of galaxies at 0.2 < z < 1.6 based on the photometric redshift information. We found several superclusters where cluster candidates are concentrated within scales of few tens of Mpc at z ~ 0.9. Interestingly, some of the supercluster candidates consist of galaxy clusters which are dominated by blue galaxies. We will present high redshift galaxy cluster and supercluster candidates in ELAIS-N1 field and galaxy properties in different environments including dense clusters and fields.

• Proceedings of the KSRS Conference
• /
• 1999.11a
• /
• pp.262-266
• /
• 1999

Several commercial companies that plan to provide improved panchromatic and/or multi-spectral remote sensor data in the near future are suggesting that merge datasets will be of significant value. This study evaluated the utility of one major merging process-process components analysis and its inverse. The 6 bands of 30$\times$30m Landsat TM data and the 10$\times$l0m SPOT panchromatic data were used to create a new 10$\times$10m merged data file. For the image classification, 6 bands that is 1st, 2nd, 3rd, 4th, 5th and 7th band may be used in conjunction with supervised classification algorithms except band 6. One of the 7 bands is Band 6 that records thermal IR energy and is rarely used because of its coarse spatial resolution (120m) except being employed in thermal mapping. Because SPOT panchromatic has high resolution it makes 10$\times$10m SPOT panchromatic data be used to classify for the detailed classification. SPOT as the Landsat has acquired hundreds of thousands of images in digital format that are commercially available and are used by scientists in different fields. After the merged, the classifications used supervised classification and neural network. The method of the supervised classification is what used parallelepiped and/or minimum distance and MLC(Maximum Likelihood Classification) The back-propagation in the multi-layer perception is one of the neural network. The used method in this paper is MLC(Maximum Likelihood Classification) of the supervised classification and the back-propagation of the neural network. Later in this research SPOT systems and images are compared with these classification. A comparative analysis of the classifications from the TM and merged SPOT/TM datasets will be resulted in some conclusions.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.403-406
• /
• 2005

In order to evaluate the Capability of ETM+ remotely- sensed data to provide 'Forest-shrub land-Rangeland' cover type map in areas near the timberline of northern forests of Iran, the data were analyzed in a portion of nearly 790 ha located in Neka-Zalemroud region. First, ortho-rectification process was used to correct the geometric errors of the image, yielding 0/68 and 0/69 pixels of RMS. error in X and Y axis, respectively. The original and panchromatic bands were fused using PANSHARP Statistical module. The ground truth map was made using 1 ha field plots in a systematic-random sampling grid, and vegetative form of trees, shrubs and rangelands was recorded as a criteria to name the plots. A set of channels including original bands, NDVI and IR/R indices and first components of PCI from visible and infrared bands, was used for classification procedure. Pair-wise divergence through CHNSEL command was used, In order to evaluate the separability of classes and selection of optimal channels. Classification was performed using ML classifier, on both original and fused data sets. Showing the best results of $67\%$ of overall accuracy, and 0/43 of Kappa coefficient in original data set. Due to the results represented above, it's concluded that ETM+ data has an intermediate capability to fulfill the spectral variations of three form- based classes over the study area.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.11a
• /
• pp.101-104
• /
• 2006

Water management is considered to be one of the main issues to be addressed for the performance improvement of proton exchange membrane (PEM) fuel cell. For good water management, the detailed information on the water distribution inside an operating PEM fuel cell should be available to main an adequate level of hydration in the PEM While avoiding performance decline due to liquid rater flooding. For the PEM fuel cell to be commercially viable as vehicle applications, the flooding on the cathode side should be minimized during the fuel ceil operation. In this study to investigate cathode flooding and its relation with temperature distribution in flow channels, visualization study was performed on the cathode side of a PEM fuel cell. For the direct visualization of temperature field and water transport in cathode flow channels, a transparent cell was designed and manufactured using quartz window. Water transport and its two-phase flow characteristics in flow channels were investigated experimentally. Also, the visualization of temperature distribution In cathode flow channels was made by using IR camera. Results indicated that the temperature rise near the exit of cathode flow channel was found. It is found that this area corresponds to the flooding area from both temperature and flooding visualization results It is expected that this study can effectively contribute to get the detailed data on water transport linked with heat management during the operation of a PEM fuel cell