• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1449-1455
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• 2022

A radiotracer investigation was carried out in a Thermal Stratification Test Facility (TSTF) with objectives of investigating the dispersion and diffusion of radionuclide and effectiveness of the thermocline to minimize the radionuclide content in the hot water layer. Technetium-99m (^99mTc) as sodium pertechnetate was used as a radiotracer in the investigation. Qualitative analysis showed that a thermocline is formed within the TSTF and is effective in preventing the transport of radionuclide from bottom section to the top section of the facility. It was found that the radiotracer injected at the bottom of the pool took about 17.4 h to disperse from bottom to the top of the facility. The results of the investigation helped in understanding the effectiveness of hot water layer and thus to minimize the pool top radiation levels.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.2
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• pp.152-157
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• 2019

Polo-like kinase 1 (Plk1) is crucial regulator of cell cycle progression during mitosis. It is known to highly overexpress in many different tumor types, and has been implicated as a potential antimitotic cancer target. The phosphopeptide, Pro-Leu-His-Ser-p-Thr (PLHSpT), was shown a high level of affinity and specificity for the polo-box domain (PBD) of Plk1. However, the peptide has the limitation of cell permeability. We designed the derivatives to enhance the limitation of PLHSpT using drug delivery system. In addition, we synthesized and evaluated its radiotracer for tumor diagnosis. This review discusses the derivative and radiotracer that are suitable for tumor treatment and diagnosis for PBD of Plk1.

• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.196-208
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• 2017

This study presents an experimental work in a petrochemical company for scanning a buried pipeline using $Tc^{99m}$ radiotracer based on the measured velocity changes, in order to determine the flow reduction along a pipeline. In this work, $Tc^{99m}$ radiotracer was injected into the pipeline and monitored by sodium iodide scintillation detectors located at several positions along the pipeline. The flow velocity has been calculated between every two consecutive detectors along the pipeline. Practically, six experiments have been carried out using two different data acquisition systems, each of them being connected to four detectors. During the fifth experiment, a bypass was discovered between the scanned pipeline and another buried parallel pipeline connected after the injection point. The results indicate that the bypass had a bad effect on the volumetric flow rate in the scanned pipeline.

• Journal of Radiation Industry
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• v.5 no.4
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• pp.317-323
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• 2011

Radioisotopes have been widely used throughout industry to optimize processes, solve problems and improve product quality. A gamma scanning technique using radiation via sealed source (Co-60) was carried out in order to investigate vertical density profile of catalyst regenerator of RFCCU. Also through the radiotracer experiments, the flow characteristics of catalyst was measured. The catalyst samples were irradiated with neutron in HANARO reactor to produce lanthanum-140 to be used as radiotracer for tracing the catalyst itself in catalyst regenerator of RFCCU. The radiotracer was monitored around the catalyst regenerator using collimated NaI scintillation detectors. The results of the experiments were used to diagnose the performance of the RFCCU.

• Journal of Radiation Industry
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• v.9 no.3
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• pp.131-135
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• 2015

The flow characteristics of fluid were measured using radioactive tracer in pilot scale digester with tray motion mixer. In consideration of the detection volume of the detector and the size of the digester, 20 detectors were installed in the digester. The radioactive tracer eluted 8 mCi of $^{68}Ga$ from $^{68}Ge/^{68}Ga$ generator was injected into the digester bottom. After radiotracer injection, the flow pattern was measured on the basis of the initial movement of the tracer until its diffusion completely. Most of tracer moved to the wall along the bottom of the digester, and then rose along the wall. The other tracer moved up along the mixer, and then moved to the wall direction along the surface.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.1
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• pp.36-47
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• 2019

Hypoxia-inducible factor-1 ($HIF-1{\alpha}$) is a transcription factor activated in response to low oxygen level, and is highly expressed in many solid tumors. Moreover, $HIF-1{\alpha}$ is a representative biomarker of hypoxia and also helps to maintain cell homeostasis under hypoxic condition. Most solid tumors show hypoxia, which induces poor prognosis and resistance to conventional cancer therapies. Thus, early diagnosis of hypoxia with positron emission tomography (PET) radiotracer would be highly beneficial for management of malignant solid tumors with effective cancer therapy. YC-1 is a most promising candidate among several $HIF-1{\alpha}$ inhibitors. As an effort to develop a hypoxia imaging tool as a PET radiotracer, we designed and synthesized [$^{18}F$]DFYC based on potent derivative of YC-1 and performed preliminary in vitro cell uptake study. [$^{18}F$]DFYC showed a significant accumulation in SKBR-3 cells among other cancer cells, proving as a good lead to develop a hypoxic solid tumor such as breast cancer.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.3
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• pp.162-170
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• 2004

On the basis of the radiotracer technology and the related equipments which have been developed for its industrial application through the nuclear long-term research project, a radiotracer study on sediment transport was carried out as a part of the development of the radiotracer technology for a coastal environment. The crystalline material doped with iridium having a similar composition and specific gravity as those of the bedload sand collected from the research area was produced by the oxide-route method. A radioisotope container was specially designed to inject the radiotracer from 1 m above the sea bedload without radioactive contamination during the transport from the nuclear reactor at KAERI. The position data from the DGPS and the radiation measurement data were collected concurrently and stored by means of the application software programmed with the LabVIEW of the National Instrument. The position data was reprocessed to represent the real position of the radiation probe under water and not that of the DGPS antenna on board. The time dependency of the spatial distribution of the sediment was studied in the area through three tracking measurements after the iridium glass was injected. This trial application showed the potential of the radiotracer technology as an important role for maintaining and developing the coastal environment in the future.

• Journal of Radiation Protection and Research
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• v.32 no.3
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• pp.117-122
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• 2007

The hydrodynamic behaviors of the clarifier with an interior baffle in a wastewater treatment plant was investigated by using a radiotracer $^{99m}Tc$(30 40 mCi) to verify the results of CFD(computational fluid dynamics) modelling in the previous study. The clarifier model was manufactured with consideration to the hydraulic similarity(1/21) of a real plant($L{\times}W{\times}H:2.6{\times}0.4{\times}0.2m$). By installation of an interior baffle to the clarifier, the strong density current at the bottom of the clarifier decreased substantially and increased the area of sludge settling zone, which were visualized successfully from the radiotracer experiment. Also the portion of short circuit stream changed from 48 % to 32 % and the mean residence time of sludge decreased from 940 sec to 810 sec, which corresponds to the results of CFD modelling. As a result, it is anticipated that radiotracer technology can be used as an important tool for designing new wastewater treatment plants and verifying their performances after structural modifications.

• 대한핵의학회:학술대회논문집
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• 2006.05a
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• pp.29-35
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• 2006

• Toxicological Research
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• v.8 no.2
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• pp.303-316
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• 1992