Silica is used in shell materials to minimize oxidation and aggregation of nanoparticles. Particularly, porous silica has gained attention because of its performance in adsorption, catalysis, and medical applications. In this study, to investigate the effect of the density of the silica coating layer on the color of the pigment, we arbitrarily change the structure of a silica layer using an etchant. We use NaOH or NH4OH to etch the silica coating layer. First, we synthesize α-FeOOH for a length of 400 nm and coat it with TEOS to fabricate particles with a 50 nm coating layer. The coating thickness is then adjusted to 30–40 nm by etching the silica layer for 5 h. Four different shapes of α-FeOOH with different colors are measured using UV–vis light. From the color changes of the four different shapes of α-FeOOH features during coating or etching, the L* value is observed to increase and brighten the overall color, and the b* value increases to impart a clear yellow color to the pigment. The brightest yellow color was that coated with silica; if the sample is etched with NaOH or NH4OH, the b* value can be controlled to study the yellow colors.

One of the major sources causing eutrophication and algal blooms of lakes or streams is phosphorus which comes from point and nonpoint pollution sources. HAP (hydroxyapatite) crystallization using granular alkaline materials can achieve the decrease of phosphorus load from wastewater treatment plants and nonpoint pollution control facilities. In order to induce HAP crystal formation, continuous supply of calcium and hydroxyl ions is required. In this research, considering HAP crystallization, several types of lime-based granular alkaline materials were prepared, and the elution characteristics of calcium and hydroxyl ions of each were analyzed. Also, column tests were performed to verify phosphorus removal efficiencies of granular alkaline materials. Material_1 (gypsum+cement mixed material) achieved the highest pH values in the column tests consistently, also, Material_2 (gypsum+slag mixed material) and Material_3 (calcined limestone material) achieved over pH 9.0 for 240 hours (10 days) and proved the efficiencies of long-term ion supplier for HAP crystallization. In the column tests using Material_3, considerable pH increase and phosphorus removal were carried out according to each linear velocity and filtration depth. T-P removal efficiencies were 87.0, 84.0, 68.0% and those of PO4-P 100.0, 97.0, 80.0% for linear velocity of 1.0, 2.5, 5.0 m/hr respectively. Based on the column test results, the applicability of phosphorus removal processes for small-scale wastewater treatment plants and nonpoint pollution control facilities was found out.

Nitrogen-doped titanium dioxide (N-doped TiO2) is attracting continuously increasing attention as a material for environmental photocatalysis. The N-atoms can occupy both interstitial and substitutional positions in the solid, with some evidence of a preference for interstitial sites. In this study, N-doped TiO2 is prepared by the sol–gel method using NH4OH and NH4Cl as N ion doping agents, and the physical and photocatalytic properties with changes in the synthesis temperature and amount of agent are analyzed. The photocatalytic activities of the N-doped TiO2 samples are evaluated based on the decomposition of methylene blue (MB) under visible-light irradiation. The addition of 5 wt% NH4Cl produces the best physical properties. As per the UV-vis analysis results, the N-doped TiO2 exhibits a higher visible-light activity than the undoped TiO2. The wavelength of the N-doped TiO2 shifts to the visible-light region up to 412 nm. In addition, this sample shows MB removal of approximately 81%, with the whiteness increasing to +97 when the synthesis temperature is 600℃. The coloration and phase structure of the N-doped TiO2 are characterized in detail using UV-vis, CIE Lab color parameter measurements, and powder X-ray diffraction (XRD).

토양수분은 지면환경에서 일어나는 수문 순환을 이해하기 위한 중요한 기상인자일 뿐만 아니라 가뭄, 홍수, 산불 등과 같은 자연재해와 밀접하게 연관되어 있다. 그러나 위성기반 토양수분 자료는 공간해상도가 매우 떨어져서 국지규모 분석에 직접적 으로 적용하기에는 한계가 있다. 이 연구에서는 마이크로파 위성센서로부터 산출된 토양수분 자료가 가지는 공간해상도의 제약을 완화하기 위하여, 다양한 지면 변수와 공간통계법을 활용한 다운스케일링 기법을 도입하였다. 가장 정교한 다운스케일링 기법으로 평가되는 회귀크리깅을 이 연구를 통하여 토양수분 자료에 처음으로 적용하였다. 우리나라의 2013년과 2014년의 4월부터 10월까지 의 일자별 AMSR2(Advanced Microwave Scanning Radiometer 2) 공간해상도 10km와 25km의 토양수분 자료를 각각 2km와 4km로 다운스케일링한 결과, 고해상도로 다운스케일링된 자료와 저해상도 원자료와의 일관성이 우수하게 유지되어, 다운스케일링 전후의 공간패턴과 자료특성이 잘 보존되는 것을 확인할 수 있었다. 이 연구에서 제시한 다운스케일링 기법은 토양수분뿐만 아니라 여러 기상요소에 적용될 수 있으며, 위성영상이나 모형자료의 공간해상도 한계를 극복하기 위한 방편이 될 수 있을 것으로 기대된다.

본 연구에서는 축산식품인 편육을 대상으로 황색포도상 구균의 성장예측모델을 개발하였다. 편육에서 황색포도상 구균의 성장패턴은 4, 10, 20, 37oC의 보관온도에서 측정 되었으며, 황색포도상구균은 각각의 저장 온도에서 모두 증가하는 것으로 나타났다. 편육에 오염된 황색포도상구 균의 생육결과를 토대로 Baranyi model을 이용하여 유도 기(LPD)와 최대성장률(μmax)을 산출한 결과, 유도기는 4, 10, 20, 37oC에서 212.81, 79.67, 3.12, 2.21 h으로 온도에 반비례한 것으로 나타났고 최대성장률은 같은 보관온도에 서 0.004, 0.009, 0.130, 0.568 log CFU/g/h으로 온도에 비 례한 것으로 조사되었다. 2차 모델은 μmax의 경우, square root model, LPD는 polynomial equation을 사용하여 산출 하였고, 개발한 모델의 적합성을 평가하기 위해 통계적 지 표인 RMSE 값을 계산한 결과, 비교적 0에 가까운 0.42로 도출되어 모델이 적합한 것으로 확인되었다. 따라서 개발된 모델이 편육에 대한 황색포도상구균의 성장 예측모델로 사용 가능하다고 판단되어지며, 편육에서의 식중독을 예방하고 미생물학적 위생관리기준을 설정하는데 기초자 료로 활용될 수 있을 것으로 사료된다.

We synthesized potassium hexatitanate, (K2Ti6O13, PT6), with a non-fibrous shape, by acid leaching and subsequent thermal treatment of potassium tetratitanate (K2Ti4O9, PT4), with layered crystal structure. By controlling nucleation and growth of PT4 crystals, we obtained splinter-type crystals of PT6 with increased width and reduced thickness. The optimal holding temperature for the layered PT4 was found to be ~920 oC. The length and width of the PT4 crystals were increased when the nucleation and growth time were increased. After a proton exchange reaction using aqueous 0.3 M HCl solution, and subsequent heat treatment at 850 oC, the PT4 crystal transformed into splinter-type PT6 crystals. The frictional characteristics of the friction materials show that as the particle size of PT6 increases, the coefficient of friction (COF) and wear amounts of both the friction materials and counter disc increase.

온난화와 같은 전지구적 변화는 기온과 강수 등 기상요소에 직접적으로 반영되어 곡물 수확량의 변화를 가져온다. 기후변화 시나리오에 기초한 선행연구들에서는 GCM (general circulation model)의 공간해상도 문제로 인하여 상세한 모의가 어려웠고, 시계열통계법을 활용한 연구들에서는 기후요소를 통합하여 수확량을 예측한 사례가 매우 드물었다. 이에 본 연구에서는 상세화된 기후재분석자료의 시계열모델링을 통하여 옥수수와 콩의 수확량 예측실험을 수행하였다. 미국 아이오와 주의 99개 카운티를 대상으로 1960년부터 2009년까지 50년간의 고해상도 기후재분석자료와 정부통계 수확량 DB를 구축하고, 시계열통계법인 VAR (vector autoregression)와 ARIMA (autoregressive integrated moving average)를 이용하여 다음해 수확량 예측실험을 10개 연도에 대해 수행하여 예측력을 평가하였다. VAR는 16-18%, ARIMA는 11-14% 의 오차율로 다음해의 수확량을 예측할 수 있는 것으로 집계되었으며, 옥수수의 경우 표토의 산성도, 심토의 점토와 나트륨 함유량 등의 토양특성 이 실제 수확량 및 예측정확도에 영향을 미치는 것으로 나타났다.

Along with toothbrushes, toothpaste has been used for a long time to improve the personal oral hygiene. Toothpaste was firstly introduced to Korea through as a form of powder by the Japanese company Lion Corporation in 1889 and in 1954, the LakHee Chemistry company released Korea’ s first ever tube type cream toothpaste called lucky toothpaste, and afterwards we got to where we are today in terms of toothpaste. As a variety of products are released and customer choices become more diverse, there needs to be a development of toothpaste that can fulfill customers’ needs and requests. Therefore, this study analyzes toothpastes and related patents submitted to the Patent Office from 1962 to June 2015, thereby examining the changes in toothpaste development trends up to the present day. This study was searched using the keyword ‘toothpaste’ in the patent, utility model search engine at Kipris(www.kipris.or.kr), a patent search site, and categorized a total of 2,465 patents, which excluded those rejected by the Patent Office and those unrelated to toothpaste, using titles, full texts of publications and announcements. Research results showed that in the past, from 1960 to 1989, patents related to toothpaste containers took up the highest ratio of 35%. However, after 1990, patents pertaining to toothpaste composites and functionality made up the highest percentage of 54%, and from 2010 to 2015, it occupied 72% of the whole; therefore, we analyzed in detail the patents related to composites and functionality. Taking a look at the objectives and effects of patents having to do with composites and functionality, we found out that from 1964 to June 2015, patents related to Base, a basic component of toothpaste, and those having to do with periodontal disease took up the highest percentages of 25% each, and from 2010~2015 in particular, patents concerning periodontal diseases were submitted 3% more than those about Base. Composites aiming to prevent and treat periodontal diseases can be divided into four different categories, based on components; among those, there were a total of 171 (57%) patents related to living organism and herbal medicine extracts, 107 (36%) patents using compounds, 16 (5%) patents using bamboo salt as well as salt, and 5 (2%) patents using mineral components such as gold, silver. Looking at these investigation results, it can be thought that with the increasing development of toothpaste related to periodontal diseases, there’ s a great amount of interest about toothpaste of effective periodontal disease prevention and treatment purposes. Along with this, we thought that research about how effective periodontal disease toothpastes actually are is also necessary.

cording to histopathological characteristics. One is composite tumor, and the other is collision tumor. Composite tumor is a lesion showing the combined histopathological characteristics of two or more previously recognized tumor and/or cysts of different categories. Two constituent parts are mixed with each other, and histological transition is often observed. On the other hand, collision tumor is a lesion showing the independent histopathological characteristics of two or more previously recognized tumor and/or cysts of different categories. Two constituent parts are separated each other by connective tissue, and histological transition is not observed. Their origin is still unclear. In this study, a collision tumor was reported. 77-year old woman was referred to CNUH with a neck mass in right submandibular area. Incisional biopsy was carried out, and the patient was diagnosed as collision tumor of squamous cell carcinoma and neurofibroma. After reviewing studies reporting collision tumor from head and neck area, formation of a collision tumor was most frequent from a cervical area and average age is 59.6. A collision tumor commonly lead to misdiagnosis, and the prognosis is not always transparent. The variety symptom of collision tumor has to be kept in mind in the diagnosis and treatment of the lesions in head and neck area.