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

• Analytical Science and Technology
• /
• v.30 no.6
• /
• pp.312-318
• /
• 2017

The shelf life of 1,2-indandione/zinc (1,2-IND/Zn) solution and polyvinylpyrrolidone (PVP) solution, which are known as reagents for developing latent fingermarks deposited on the surface of thermal paper, was studied. The standard latent fingermarks used for comparisons were artificial latent fingermarks printed on thermally sensitive and non-sensitive surfaces with the same intensity. Upon treatment of standard latent fingermarks with the pre-mixed 1,2-IND/Zn and PVP solutions, the fingermarks could be successfully developed until 3 days after the preparation of the mixture. However, from the third day after mixing the reagents, blackening was observed on the surface of the thermal paper, indicating deterioration of the reagent performance. The 1,2-IND/Zn and PVP solutions separately stored without mixing in advance were mixed immediately before use, and the development efficiency of the latent fingermarks deposited on the surface of thermal paper was observed. The performance of the PVP solution decreased after 20 days from the preparation of the reagent. It was also found that the shelf life of 1,2-IND/Zn and PVP mixture was determined by the PVP solution. The effect of oxygen and moisture on the degradation of PVP was investigated. It was found that the performance of the PVP solution deteriorated because of the influence of moisture, though it was not affected by oxygen.

• Analytical Science and Technology
• /
• v.32 no.3
• /
• pp.105-112
• /
• 2019

Fingerprints may be contaminated with ethanol solutions. In order to solve the case, the law enforcement agency may need to visualize the fingerprint from these samples, but the development method has not been studied. The paper with latent fingerprint was contaminated with ethanol solution and then the blurring of ridge detail was observed. As a result, when the copy paper was contaminated with ethanol solutions of less than 75 % (v/v), the amino acid components of latent fingerprint residue blurred but lipid components of latent fingerprint residue didn't blurred. On the other hand, when the paper was contaminated with ethanol solution of more than 80 % (v/v), the amino acid components of latent fingerprint didn't blurred but the lipid components of latent fingerprint blurred. Therefore, it is found that the paper contaminated with ethanol solutions of less than 75 % (v/v) should be treated by oil red O (ORO) enhancing lipid components, and the paper contaminated with ethanol solutions of 80 % (v/v) or more should be treated by 1,2-indandione/zinc (1,2-IND/Zn) enhancing amino acid components. The blurring of ridge detail was not observed when the fingerprints were deposited with fingers contaminated with ethanol solution. This fingerprints were treated with 1,2-IND/Zn or ORO to compare the latent fingerprint development ability, and using 1,2-IND/Zn was able to visualize the latent fingerprint more clearly than using ORO.

• The Journal of the Korea Contents Association
• /
• v.16 no.9
• /
• pp.247-253
• /
• 2016

Some previous studies had proven that ninhydrin or its analogues are not effective in developing fingermarks on some types of paper. This study has evaluated the efficiency of four reagents for detecting latent fingermarks on six unusual paper surfaces. Among the six types of paper surfaces, none of the reagents worked on the newspaper. The 1,2-IND/Zn developed fingermarks on most of the surfaces tested.

• Analytical Science and Technology
• /
• v.28 no.1
• /
• pp.26-32
• /
• 2015

The consistency and homogeneity of repetitive printing of artificial fingerprint were evaluated using a visual minutiae comparison method and an Automated Fingerprint Identification System (AFIS). The standard latent fingerprint pattern was prepared by the printing of a master digital fingerprint pattern with an inkjet printer cartridge case filled with artificial sweat. The master digital fingerprint pattern was prepared with a scanning of an inked fingerprint pattern of a living subject. The intensities of the master digital fingerprint pattern were adjusted by changing the 'output level' values of the Adobe Photoshop CS 5 software. Number of standard latent fingerprint patterns were printed and then developed with conventional latent fingerprint developing methods; ninhydrin treatment method and 1,2-indandion(1,2-IND)/$ZnCl_2$ treatment method. The ridge details of the latent fingerprint patterns developed with the reagents were visually compared with the inked fingerprint pattern and could confirm that the minutiae of both patterns are visually identical. The ridge detail of the inked fingerprint and reagent developed standard latent fingerprint patterns were compared with an AFIS. The average number of minutiae searched by the AFIS was $52.4{\pm}2.4$ (range = 48~56) for 50 ninhydrin developed latent fingerprint patterns, and $50.2{\pm}1.9$ (range = 47~53) for 50 1,2-IND/$ZnCl_2$ developed latent fingerprint patterns. These low standard deviation values over 50 repetitive printing demonstrated that the 50 standard latent patterns were printed with consistent and homogeneous manner.

• The Journal of the Korea Contents Association
• /
• v.17 no.1
• /
• pp.92-99
• /
• 2017

Kicking someone has clothes on causes direct contact between victim's clothes and skin. This contact makes material exchange from skin to inner clothes. In this study, foot impressions by transferred to cloths from skin would be enhanced by amino acid staining reagent (ninhydrin, 1,2-IND/Zn, DFO). In view of research ethics, we conducted this research with porcine skin instead of human's one. To mimic human's skin condition, applied artificial sweat on porcine skin. According to results, ninhydrin showed high contrast on light colored background and 1,2-IND/Zn, DFO showed high contrast on dark colored background. It showed different results up to kind of fabrics.

• Transactions on Electrical and Electronic Materials
• /
• v.15 no.4
• /
• pp.198-200
• /
• 2014

100 nm thick Ga doped ZnO (GZO) thin films were deposited with RF magnetron sputtering on polyethylene terephthalate (PET) and ZnO coated PET substrate and then the effect of the ZnO thickness on the optical and electrical properties of the GZO films was investigated. GZO single layer films had an optical transmittance of 83.7% in the visible wavelength region and a sheet resistance of $2.41{\Omega}/{\square}$, while the optical and electrical properties of the GZO/ZnO bi-layered films were influenced by the thickness of the ZnO buffer layer. GZO films with a 20 nm thick ZnO buffer layer showed a lower sheet resistance of $1.45{\Omega}/{\square}$ and an optical transmittance of 85.9%. As the thickness of ZnO buffer layer in GZO/ZnO bi-layered films increased, both the conductivity and optical transmittance in the visible wavelength region were increased. Based on the figure of merit (FOM), it can be concluded that the ZnO buffer layer effectively increases the optical and electrical performance of GZO films as a transparent and conducting electrode without intentional substrate heating or a post deposition annealing process.

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

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.178.1-178.1
• /
• 2015

In and Ga doped ZnO (IGZO) thin films were prepared by radio frequency magnetron sputtering without intentional substrate heating on glass substrate and TiO2-deposited glass substrates to consider the effect of a thin TiO2 buffer layer on the optical and electrical properties of the films. The thicknesses of the TiO2 buffer layer and IGZO films were kept constant at 5 and 100 nm, respectively. Since the IGZO/TiO2 bi-layered films show the higher FOM value than that of the IGZO single layer films, it is supposed that the IGZO/TiO2 bi-layered films will likely perform better in TCO applications than IGZO single layer films.

• Journal of the Korea Convergence Society
• /
• v.11 no.6
• /
• pp.75-82
• /
• 2020

We identify the enhancement effects of zinc chloride and liquid nitrogen on low quality ninhydrin-developed fingerprint and we wanted to find out another cooling methods available for ninhydrin/Zn fingerprint enhancement besides the liquid nitrogen, which is hard to access. Artificial sweat was used to make the same level of fingerprints, and fingerprints developed by each technique were evaluated by SWGFAST standard and compared the average score and standard deviation. As a result of the experiment, ninhydrin/Zn-liquid nitrogen got 3.2 and 3.3 as average scores that enough to identify an individual such as 1,2-IND/Zn or DFO. Also, experiments using dry ice instead of liquid nitrogen as a way of the ninhydrin/Zn-developed fingerprints enhancement resulted in 3.0 and 2.9 as average scores, therefore, it was confirmed that dry ice is also a sufficient cooling method to be considered in practice in the field of forensic science.