• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.3
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• pp.95-102
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• 2016

This study investigated the effects of the oxygen permeability of vacuum packaging film and the storage temperature on the quality and shelf life of Hamburg steaks during storage for 14 days. Control samples (C) were packaged in a polyamide/polyethylene (PA/PE) film and stored at $5^{\circ}C$. Treatment samples were either packaged in an ethylene vinyl alcohol/polyethylene (EVOH/PE) copolymer film and stored at $5^{\circ}C$ (T1), and in a PA/PE film and stored at $-18^{\circ}C$ (T2). The initial total plate count (TPC) was 3.6 log cfu/g. In T1 samples, TPC and Brochothrix thermosphacta counts were increased, similar to those in C samples, whereas Pseudomonas spp. counts were significantly lower than those in C samples during storage. Over the storage period, the volatile basic nitrogen values increased most rapidly in C samples, followed by T1 and then T2 samples. The values of thiobarbituric acid reactive substances steadily increased in all samples during storage. The colour parameters were not significantly different among the samples during storage. T1 samples maintained sensory qualities in flavour and off-odour parameters for two days longer than C samples did. At day 12, T2 samples were evaluated as being below the marketability score of 5.0 for texture. In conclusion, using high oxygen barrier films like EVOH/PE copolymer for packaging Hamburg steaks could extend the sensory qualities in view of flavour and off-odour during chilled storage. However, frozen storage at $-18^{\circ}C$ is recommended when the storage period is extended beyond 14 days at $5^{\circ}C$.

• Progress in Medical Physics
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• v.28 no.3
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• pp.100-105
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• 2017

The purpose of the present study was to develop and evaluate patient-customized helmets with a three-dimensional (3D) printer for radiation therapy of malignant scalp tumors. Computed tomography was performed in a case an Alderson RANDO phantom without bolus (Non_Bolus), in a case with a dental wax bolus on the scalp (Wax_Bolus), and in a case with a patient-customized helmet fabricated using a 3D printer (3D Printing_Bolus); treatment plans for each of the 3 cases were compared. When wax bolus was used to fabricate a bolus, a drier was used to apply heat to the bolus to make the helmet. $3-matic^{(R)}$ (Materialise) was used for modeling and polyamide 12 (PA-12) was used as a material, 3D Printing bolus was fabricated using a HP JET Fusion 3D 4200. The average Hounsfield Unit (HU) for the Wax_Bolus was -100, and that of the 3D Printing_Bolus was -10. The average radiation doses to the normal brain with the Non_Bolus, Wax_Bolus, and 3D Printing_Bolus methods were 36.3%, 40.2%, and 36.9%, and the minimum radiation dose were 0.9%, 1.6%, 1.4%, respectively. The organs at risk dose were not significantly difference. However, the 95% radiation doses into the planning target volume (PTV) were 61.85%, 94.53%, and 97.82%, and the minimum doses were 0%, 77.1%, and 82.8%, respectively. The technique used to fabricate patient-customized helmets with a 3D printer for radiation therapy of malignant scalp tumors is highly useful, and is expected to accurately deliver doses by reducing the air gap between the patient and bolus.