• Analytical Science and Technology
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• v.20 no.2
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• pp.155-163
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• 2007

Porosity paper evidence is encountered in case of forgery, kidnapping, fraud and terrorist activity. The present study was designed to evaluate the effect of three chemical reagents (Ninhydrin, 1,8-diazafluoren-9-one (DFO), Iodine fuming) to the quality of developed latent fingerprints on porosity printing papers and newspaper. In case of printing papers, print quality was better with Iodine fuming method than Ninhydrin and DFO treatment to developing latent fingerprints. Developing latent fingerprint on newspapers was achieved with Iodine fuming processing. The processing of Iodine fuming followed by DFO and by using blue light (orange red filter) exhibited better results with Iodine fuming. Enhancement of latent fingerprint detection image using Digital Imaging System was achieved.

• Bulletin of the Korean Chemical Society
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• v.28 no.8
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• pp.1311-1316
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• 2007

To develop photo-sensitizers for dye-sensitized solar cells (DSCs) used in harvesting sunlight and transferring solar energy into electricity, we synthesize novel Ru(II) polypyridyl dyes and describe their characterization. We also investigate the photo-electrochemical properties of DSCs using these sensitizers. New dyes contain chromophore unit of dafo (4,5-diazafluoren-9-one) or phen-dione (1,10-phenanthroline-5,6-dione) instead of the nonchromophoric donor unit of thiocyanato ligand in cis-[RuII(dcbpy)2(NCS)2] (dcbpy = 4,4'-dicarboxy- 2,2'-bipyridine) coded as N3 dye. For example, the photovoltaic data of DSCs using [RuII(dcbpy)2(dafo)](CN)2 as a sensitizer show 6.85 mA/cm2, 0.70 V, 0.58 and 2.82% in short-circuit current (Jsc ), open-circuit voltage (Voc), fill factor (FF) and power conversion efficiency (Eff), which can be compared with those of 7.90 mA/ cm2, 0.70 V, 0.53 and 3.03% for N3 dye. With the same chelating ligand directly bonded to the Ru metal in the complex, the CN ligand increases the Jsc value by double, compared to the SCN ligand. The extra binding ability in these new dyes makes them more resistant against ligand loss and photo-induced isomerization within octahedral geometry.

• Analytical Science and Technology
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• v.32 no.3
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• pp.113-119
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• 2019

Enhancement of footwear impressions in urine on the surface of tiles by using p-dimethylaminocinnamaldehyde (DMAC), which react with urea, and ninhydrin, 1,8-diazafluoren-9-one (DFO), 1,2-indanedione/zinc (1,2-IND/Zn), which react with amino acid, was studied. As a result of comparing the application methods of reagents, the ninhydrin and the 1,2-IND/Zn were suitable for application with spray method, which is spray directly on footwear impression, DFO and DMAC were suitable for application with dry contact method, which is applying heat with press to DMAC impregnated paper on footwear impression. In addition, DMAC applied with dry contact method showed best contrast and enhancement result in both white and black colored tiles by comparing of the sensitivity by different dilution ratio of urine and the aging time of footwear impressions in urine. And the result of applied with DMAC (with dry contact method) on the floor tiles collected at various places in a building's men's and women's bathrooms, it can be successfully enhanced that footwear impressions in urine. So it is believed that the method can be used to recover footwear impressions in urine from real crime scenes.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.105-114
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• 2018

Ninhydrin traditionally used to develop fingerprints on paper is often limited in its use depending on background color and its enhancement effect differs depending on reagent reaction condition. Recently 1,2-indanedione(1,2-IND), etc. which has no limitation of background color has been used to visualize the fingermark on paper. Therefore, this study was carried out for enhancement of fingerprints after 1,2-IND/Zn treatment on paper treated with ninhydrin. Comparison between 1,2-IND/Zn reaction after ninhydrin treatment and single ninhydrin reaction were conducted under various methods. Result shows the fingerprints were enhanced when ninhydrin-treated fingerprints were treated with 1,2-IND/Zn, and their enhancement was observed even after 6 months.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.569-575
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• 2017

Forensic light source is commonly used for enhancing evidence in a nondestructive way. Latent fingerprints play an important role in an aspect of crime scene investigation. In this study, researchers compared enhancement of standard fingerprints treated with DFO and 1,2-IND in accordance with laser and LED light sources. As a result, laser light source has a better effect rather than LED light sources. However, each light source has strengths and weaknesses in terms of performance and portability. Therefore, researchers recommend that crime scene investigators need to use laser and LED light sources depending on the situation.

• Fire Science and Engineering
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• v.32 no.3
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• pp.88-94
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• 2018

Fingerprints deposited on paper found at a fire scene are important evidence for determining a suspect's identity. On the other hand, because the temperature at the fire scene is very high, there are many difficulties in developing fingerprints. This study compared the effectiveness of ninhydrin, DFO, and silver nitrate to develop fingerprints deposited on paper exposed to high temperatures. Using a dry heat press, heat was applied to the paper at $200^{\circ}C$ for various times. Silver nitrate was found to be superior to the others under all conditions. Ninhydrin developed fingerprints weakly compared to DFO and silver nitrate. In addition, the sensitivity of DFO decreased with increasing exposure time. Therefore, it is recommended silver nitrate be used to develop fingerprints deposited on paper found at a fire scene.