젤리 제형에 대한 소르비톨의 첨가가 젤리를 fused deposition modeling 방식으로 3D 프린팅 하기 위해 요구되는 소재 필요 요건에 미치는 영향을 연구하였다. 연구에 사용된 젤리 제형은 젤라틴(10 wt%), 펙틴(7 wt%), 설탕 또는 소르비톨(30 wt%), 그리고 구연산(1 wt%)이었다. 제형의 유변학적 특성은 cup & bob geometry를 장착한 레오미터를 이용하여 25 ℃에서 frequency sweep test (0.1-100 rad/s)와 strain sweep test (0.1-100%)를 수행하여 측정하였고, gel strength는 cylinder measuring probe (p/0.5HS)가 장착된 texture analyzer를 이용하여 측정하였다. 소르비톨이 첨가된 소 재의 유변학적 특성과 gel strength는 기존의 설탕이 첨가된 소재(tan δ: 0.67, phase angle: 33.96, n: 0.40, gel strength: 5.91 N)와 비교하였을 때 tan δ, phase angle, flow behavior index (n), 그리고 gel strength가 각각 0.49, 26.02°, 0.28, 그 리고 1.92 N으로 감소하여 설탕을 대신한 소르비톨의 첨가가 젤리 3D 프린팅의 소재 필요 요건 중 fidelity, solidarity, extrudability, 그리고 gel strength에 영향을 미친다는 것을 확인하였다. 소재 필요요건에서 벗어난 제형(젤라틴(10 wt%), 펙틴(5 wt%), 설탕(30 wt%), 그리고 구연산(1 wt%))에 소르비톨을 첨가하였을 때 tan δ, phase angle, n, 그리고 gel strength가 각각 0.43, 23.08, 0.24, 그리고 1.08 N으로 감소하여 소르비톨의 첨가가 소재 필요요건에 벗어난 제형 을 소재 필요요건에 만족 시키는 방향으로 변화 시킴을 알 수 있었다. 본 연구를 통해 젤리 제형에 대한 소르비톨의 첨가를 이용한 소재 물성 조절 방법이 젤리를 프린팅 하는데 요구되는 소재 필요 요건에 미치는 영향을 확인할 수 있었고, 소르비톨 첨가가 젤리의 3D 프린팅에 사용되는 소재의 물성 조절 방법으로 사용될 수 있음을 확인할 수 있 었다.

Background: Hallux valgus (HV) is a foot deformity developed by mediolateral deviation of the first metatarsophalangeal joint. Although various foot-toe orthoses were used to correct the HV angle, verification of the effects of kinetics variables such as ground reaction force (GRF) through three-dimensional (3D) gait analysis according to the various type of orthoses for HV is insufficient. Objects: This study aimed to investigate the effect of soft and hard types of foot and toe orthoses to correct HV deformity on the GRF in individuals with HV using 3D motion analysis system during walking. Methods: Twenty-six subjects participated in the experiment. Participants had HV angle of more than 15° in both feet. Two force platforms were used to obtain 3D GRF data for both feet and a 3D motion capture system with six infrared cameras was used to measure exact stance phase point such as heel strike or toe off period. Total walk trials of each participant were 8 to 10, the walkway length was 6 m. Two-way repeated measures ANOVA was used to determine the effects of each orthosis condition on the various GRF values. Results: The late anteroposterior maximal force and a first vertical peak force of the GRF showed that the hard type orthosis condition significantly increased GRF compared to the other orthosis conditions (p < 0.05). Conclusion: There were significant effects in GRF values when wearing the hard type foot orthosis. However, the hard type foot orthosis was uncomfortable to wear during walking. Therefore, it is necessary to develop a new foot-toe orthosis that can compensate for these disadvantages.

In this work, TiO2 3D nanostructures (TF30) were prepared via a facile wet chemical process using ammonium hexafluorotitanate. The synthesized 3D TiO2 nanostructures exhibited well-defined crystalline and hierarchical structures assembled from TiO2 nanorods with different thicknesses and diameters, which comprised numerous small beads. Moreover, the maximum specific surface area of TiO2 3D nanostructures was observed to be 191 m2g-1, with concentration of F ions on the surface being 2 at%. The TiO2 3D nanostructures were tested as photocatalysts under UV irradiation using Rhodamine B solution in order to determine their photocatalytic performance. The TiO2 3D nanostructures showed a higher photocatalytic activity than that of the other TiO2 samples, which was likely associated with the combined effects of a high crystallinity, unique features of the hierarchical structure, a high specific surface area, and the advantage of adsorbing F ions.

급증하는 전련소비량을 감당하기 위해서 발전소는 필수적인 사회기반시설이며 안정적인 에너지 공급을 위해 발전소 내 구조적/비구조적 요소의 외부하중에 의한 안전성 평가는 반드시 필요하다. 국내에서 발생되는 지진의 상당수는 고주파 영역의 지진으로 보고되고 있으며 국내외 선행연구들에 의해 비구조적 요소가 고주파 지진에 더 많이 피해가 발생할 수 있는 것으로 연구되었다. 발전소 내에 대표적인 비구조적 요수중 하나인 전기 캐비닛의 경우 선행연구들에서 고유진동수가 10Hz 이상의 고주파 영역에 속하는 것으로 나타났으며 이에 따라 고주파 지진에 의한 안전성 평가가 필요할 것으로 판단된다. 본 연구에서는 전기 캐비닛의 고주파 지진에 의한 영향성 평가에 앞서 양문형 전기 캐비닛의 유한요소 모델을 구축하여 모드해석을 수행하였으며 진동대를 이용한 공진탐색실험 결과와 비교하여 모델의 타당성을 검토하였다. 또한 모델의 신뢰성을 높이기 위해 ABAQUS와 ANSYS Platform을 이용하여 모델을 구축하고 모드해석을 수행하였다. 실험에서 얻어진 1차, 2차 3차 전역모드의 주파수와 비교하였을 때 최대 약 5%의 오차가 발생하는 것으로 나타났다. 또한 1차, 2차, 3차 전역모드에 유효질량이 90%이상 참여하는 것으로 나타나 가장 지배적일 것으로 판단되며 모드형상이 유사한 것으로 판단되어 구축된 모델이 양문형 전기 캐비닛의 전체적인 동적 거동을 잘 모사할 수 있을 것으로 판단된다.

The objectives of this study are to explore the information source, assessment, and preferred styles of 3D virtual influencers(VI), to investigate the expected impact of advertisements with 3D VIs on brands, and to explore ways of expanding the use of 3D VIs. In-depth interviews with 40 males and females in their 20s and 30s were conducted and qualitative data were analyzed. The study results are summarized as follows. First, the information source of the 3D VI was SNS, acquaintances, and broadcasting. Second, 3D VIs were considered positively due to their attractive appearance, wide utilization, innovative use, freshness, separation from private identity, and time and cost savings, while considered negatively due to their unrealistic appearance and antipathy against replacing a person’s role. Third, the preferred appearance styles of the 3D VI differed according to the level of virtuality although the majority of interviewees preferred similar looks to real people with low virtuality. Fourth, diverse image qualities such as innovative, differentiated, trendy, high-value, professional, and future-oriented were considered as transferred to the brand advertised by 3D VIs. Fifth, advertisements with 3D VIs may help build positive perceptions of advertised brands that may lead to purchase behaviors for some consumers. Lastly, to expand the use of 3D VIs, the specific advantages of virtual models should be maximized with consideration of how to implement a variety of body types and images of models. Findings present an important foundation to generate strategies to better apply 3D VIs to the fashion market.

FDM 3D printing structures have rough surfaces and require post-treatment to improve the properties. Fumigation is a representative technique for removing surface unevenness. Surface treatment by fumigation proceeds by dissolving the surface of the protruding structure using a vaporized solvent. In this study, 3D printed PVB outputs are surface-treated with ethyl-alcohol fumigation. As the fumigation time increases, the surface flattens as ethanol dissolves the mountains on the surface of PVB and the surface valleys are filled with dissolved PVB. Through the fumigation process, the mechanical strength tends to decrease, and deformation rate increases. Ethanol vapor permeates into PVB, widening the distance between chains and resulting in weak bonding strength between chains. In order to confirm the effect of fumigation only, an annealing process is performed at 80 oC for 1, 5, 10, 30, and 50 minutes and the results of the fumigation are compared.