Zirconia has excellent mechanical properties, such as high fracture toughness, wear resistance, and flexural strength, which make it a candidate for application in bead mills as milling media as well as a variety of components. In addition, enhanced mechanical properties can be attained by adding oxide or non-oxide dispersing particles to zirconia ceramics. In this study, the densification and mechanical properties of YSZ-TiC ceramic composites with different TiC contents and sintering temperatures are investigated. YSZ - x vol.% TiC (x=10, 20, 30) system is selected as compositions of interest. The mixed powders are sintered using hot pressing (HP) at different temperatures of 1300, 1400, and 1500oC. The densification behavior and mechanical properties of sintered ceramics, such as hardness and fracture toughness, are examined.
목적 : 본 연구는 제주 해녀들을 대상으로 굴절검사와 안과검사를 수행하여 해녀들의 눈 건강 실태를 파악하고 잠수작업이 눈에 미치는 영향을 알아보고자 하였다.
방법 : 현재 지식잠수를 하고 있는 제주 해녀 33명(66안)에 대상으로 진행한 나안·교정시력검사, 타각적굴절 검사, 안압검사, 세극등현미경검사, 빛간섭단층촬영, 시야검사, 망막사진촬영, 빛간섭단층촬영 검사결과는 굴절상 태와 안과질환 병력을 조사하는데 사용되었다. 검사결과에 대한 빈도분석과 로지스틱 회귀 분석을 실시하였다.
결과 : 전체 연구 대상자의 굴절상태는 근시(43.9%)와 도난시(56.1%)가 가장 많은 것으로 나타났다. 안과질환의 이환율은 군날개 6.1%, 백내장 90.9%, 녹내장 19.7%, 망막질환 33.3%로 나타났다. 이 중 백내장이 있는 사람의 61.7%가 백내장 수술력이 있는 것으로 조사되었다. 또한 망막질환은 망막앞막(45.5%), 황반변성(27.3%), 당뇨병성 황반병증(18.2%), 중심장액맥락망막병증(9.1%) 순으로 나타났다. 로지스틱 회귀분석 결과는 해녀경력이 많을수록 백내장(Exp(B)=1.115)과 녹내장(Exp(B)=1.062)이 유발될 확률이 높은 것으로 나타났으며, 연령이 많을수록 백내 장(Exp(B)=1.220)이 유발될 확률이 높은 것으로 나타났다. 또한 해녀경력이 많을수록 중심장액맥락망막병증이 아 닐 확률이 높은 것으로 나타났다(Exp(B)=0.943).
결론 : 해녀들의 굴절상태, 난시 종류, 안압, 발병한 안과질환에 대해 기초 자료를 얻었으며, 이를 활용한 제주 해녀들의 눈 건강을 위한 가이드라인 설정과 교육에 도움이 될 것이라고 사료된다.
Insects are attracting the attention of alternative sources of protein. In order to produce high quality insects, studieson the development of safe and nutritious feed sources are needed. Given the cost of rearing insects, agricultural andindustrial by-products were good materials of insect feed. In the current study, Citrus unshiu peel (CP), soybean curdcake (SCC), soybean oil meal (SOM), and brewers dried grain (BDG) were investigated for their effects on larval growthand development of Protaetia brevitarsis. Interestingly, larvae fed on 10% SCC increased their weight by 3.5 times. Forthe larval period, they were significantly shorter than the control. Furthermore, minerals and amino acids were recordedto be high in them. The heavy metals were not detected in any of the investigated groups. These findings provided ascientific basis for the utilization of soybean curd cake as a nutritional feed source to promote larval growth and producequality insects.
Under natural conditions, black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), colonizes in warm temperateregions. Information on black soldier fly rearing, which is affected by seasonal factors in Korea, is limited. Ovipositionby black soldier flies is dependent on light intensity and wavelength. Therefore, continuous mass rearing of this fly requiresdetermination of optimal artificial conditions of illumination. In this study, we compared the number of eggs laid underan artificial light source (750 watt HPL lamp) versus nature sunlight. Our results showed that compared to ovipositionunder natural sunlight, the use of one or two lamps for 7 hours, resulted in only 43 and 76%, of the total number ofeggs laid under natural sunlight, respectively. The hatching rate under the former was much significantly lower than underthe latter.
In recent years, interest in edible insects has increased, and the number of farmers that breed insects in large quantities is increasing. As a result of mass breeding of insects, the damage from diseases and mites is also increasing. The chief aims of the investigation reached during some work are briefly stated. In this experiment, the kinds of mites and the environment of mites occurring in beneficial insects were investigated. The species with the highest frequency were Sanacassania sp., Tyrophagus sp., Canestriniidae and Gaeolaelaps sp.. Sanacassania sp. and Canestriniidae of them are reported as parasitic mites on beneficial insects.
Recently, Gryllus bimaculatus and the larva of Tenebrio molitor, Protaetia brevitarsis, and Allomyrina dichotoma were enlisted as general food ingredients by Ministry of Food and Drug Safety. As the interest in these insects is growing, the detailed investigation is needed for the standardization of suitable and safe rearing techniques. This survey was conducted via personal interviews about edible insect rearing farms in Korea. The basic feed is fermented oak sawdust for P. brevitarsis and A. dichotoma and wheat bran for T. molitor. The various feed additives are blended with each farm’s own recipes. It seems that larval weight was correlated with the rearing density and duration of the larval period. The heavy metal contents were analyzed after 48 hour starvation and they were very small amount or not detected. We believe that the present data will contribute to develop and standardize the safe rearing techniques of edible insects in Korea.
The frequency and time of the outbreak of insect diseases were investigated among the insect-rearing farms by regional groups. The purpose of this study was to predict the insect diseases and reduce the spread of diseases. From February to October 2016, 87 of diseased insects were collected in seven regions. It turned out that the pathogens for fungal diseases were identified as Metarhizium anisopliae. But in case of bacterial diseases, the pathogenicity of the bacteria isolated from the diseased insects were not confirmed. Bacterial diseases occurred mainly in June and August in Gyeonggi-do and Gangwon-do, while in Chungcheong-do, bacterial and viral disease raged. In Jeolla-do, both fungal and bacterial diseases occurred in June. Generally, bacterial diseases occurred mainly from June to October, while the frugal diseases occurred from January to March. It was concluded that the entomopathogenic fungi, Metarhizium anisopliae, tended to cause diseases during late-winter and early spring and bacteria, uncertain, was prone to cause diseases during summer. Therefore, it necessary to adequately control depending on the type of the entomopathogen.
The purpose of this study was to identify the new fungal disease of Scopendra subspinipes mutilans (Chilopoda: Scolopendridae) from Jeju island in Korea. Scopendra subspinipes mutilans are also known the Chinese red head and average 20cm in length. It is used for traditional medicine for skin-disease and tumor and S. s. mutilans is recently raised in Jeju island to use healing properties. We isolated fungi from surface of infected S. s. mutilans and incubated in SDBA at 24℃ for 14days, and then identified the morphology of the fungi by light and electron microscopy. For the specific diagnosis of Metarhizium spp. in S. s. mutilans, 18srRNA of fungi was amplified by primers ITS4_MF and LR3_MR and sequenced by using the BLAST server at the National Center for Biotechnology Information. The result of the 18srRNA sequencing alignment was Metarhizium anisopliae (99.9%). The entomopathogenic fungi, M. anisopliae would be fatal cause of higher mortality to S. s. mutilans, and it is needed in vivo assay to confirm the pathogenic activities of M. anisopliae to S. s. mutilans.
Many insects have gained increasing attention as an alternative protein for humans. Among those, the two-spotted cricket, Gryllus bimaculatus (Orthoptera: Gryllidae), was recently approved as a general food ingredient by the Korean Ministry of Food and Drug Safety. For industrial utilization of G. bimaculatus, mass rearing techniques and production system should be standardized first. In this study, we investigated the effects of five different feeds on the growth and development of G. bimaculatus. Feed is the one of the key factors that has considerable effects on rearing insects. With five different kinds of feed on 1st, 3rd, and 5th instar nymphs, the change of survival rate, body weight were monitored up to eight weeks after hatching. We concluded that 50% of soybean flour, 20% of corn powder, 10% of rice bran, 9% of milk serum, 10% of rice flour, 0.5% of microorganisms, and 0.5% of multivitamins and minerals (diet C) was the best mix for promoting growth and development of 3rd instar nymphs compared to the control diet.
In 2015, we reported a viral disease extremely fatal to Allomyrina dichotoma larvae spread in the majority of the larva-rearing farms in Korea. Currently, the virus-infected larva is diagnosed by PCR-based amplification but this requires laboratory equipment and agarose gel electrophoresis. Loop-mediated isothermal amplification (LAMP), a highly sensitive DNA amplification method, uses DNA polymerase isolated from Bacillus stearothemophilus and a set of six primers. It has great potential for field use because DNA is amplified under single temperature and the overall reaction completes in 30 min without laboratory equipments. Here, we report the development of on-site diagnosis method for Korean horn beetle larva infected by Allomyrina dichotoma Nudivirus.
목 적: 제주지역 안경사 특성에 따른 직무 중요도와 교육 필요도를 분석하여 산업체에서 요구하는 직무 능력을 갖춘 안경사 양성을 위한 기초자료를 얻고자 하였다.
방 법: 2016년 4월 3일부터 2016년 5월 2일까지 제주지역 안경 관련 산업체에 근무하는 안경사 90명을 대상으로 설문조사를 실시하였다.
결 과: 응답자의 성별, 산업체 업종, 경력, 직위 및 사업장 주소지에 따라 직무 중요도와 교육 필요도에 대한 인식 차이가 나타났다.
결 론: 안경사의 특성에 따라 직무 중요도와 교육 필요도에 대한 인식이 다르게 나타났으며, 따라서 산업 체에서 요구하는 직무분야별 능력을 강화할 수 있는 특화된 교육 프로그램 개발이 필요하다.
The purpose of this stduy was to identify accurately and promptly the Microsporidia disease of bumble bees from Gangwon in Korea. Bumble bees are crucial pollinators of various crops and microsporidia are the critical infections of these hosts. Also, the various species of bumble bees have been used: Bombus terrestris, B. lucorum, B. occidentalis, B. ignites and B. impatiens etc. The symptoms of bumble bees infected microsporidia: their abdomens become distended, paralyzed and become sluggish and die early. We have identified the morphologies of the microsporidium by electron microscopy and found that the morphology of the microsporidium is rounded spore morph, with fairly small spores as described before in many other articles. For the specific and sensitive diagnosis of Nosema in bumble bees, we have developed the improved method of Polymerase Chain Reaction (PCR) conditions for expeditious diagnosis. Two pairs of primers were tested on N. bombi and the related microsporidia; Nosema apis and Nosema sp., both of which infect bumble bees and honey bees and further we have verified and analyzed DNA sequence data of N. bombi in bumble bees by using the BLAST server at the National Center for Biotechnology Information.
The white-spotted flower chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae), is traditionally considered to be an important source of medicinal properties of suppression of cancer and prevention of liver-related diseases. Recently, it was listed as a temporal food ingredient by the Korean Ministry of Food and Drug Safety. To use this insect species without endangering wild populations and produce better quality insects, a mass rearing technique and the suitable rearing conditions are needed. The present study was carried out to determine whether different diets and temperatures can affect the larval weight of this beetle. The larval weight change of third instar larvae was tracked for 14 weeks with different combination of three rearing temperatures – 25, 27.5, and 30℃ - and two feed ingredients – soybean cake and rice bran. Among three temperatures, 27.5℃ was the best temperature condition for rearing this beetle. Among four combinations of two feed ingredients, the addition of soybean cake made significant weight increasement for third instar larvae. These results showed that adding soybean cake at 27.5℃ was the best rearing condition for larval weight gain. This rearing condition can be considered in terms of producing better insects and maximizing producers’ benefits.
The white-spotted chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae) was recently listed as a temporal food ingredient by the Korean Ministry of Food and Drug Safety. Traditionally, this beetle has been regarded as a medicine for suppressing live cancer and preventing liver-related disease. Based on these facts, this beetle has been focused as a economically important insects in Korea. Therefore, this beetle is commercially reared and distributed in Korea. As the economic importance is growing, we have investigated to enhance insect rearing conditions for better commercial value. In this study, we compared two food supplements, clay and charcoal, on the larval weight gain for second instar larvae of P. brevitarsis. Clay and charcoal are generally known as a good adsorbent for heavy metals and bio-waste. However, clay and charcoal is not a conventional feed supplements, so its effects were not investigated for insect rearing. The second instar P. brevitarsis larvae were fed fermented sawdust with seven different combinations of cla and/or charcoal, and measured body weight for 17 weeks until pupated. Addition of clay at 2.5 % w/w of the fermented sawdust diet had no negative effect on larval weight gain, and thus may improve the quality of P. brevitarsis as a commercial food.
The purpose of this multiplex PCR assay is establishment and application for rapid and simultaneous detection of six pathogens related with insect diseases. Five pathogens were chosen based on the insect disease incidence rate in South Korea and specific primers of those pathogen were designed to detect insect diseases and test multiplex PCR for detecting Fungi; Beauveria bassiana(Bb), Metarhizium anisopliae(Ma), Bacteira; Bacillus thuringiensis(Bt), Pseudomonas aeruginosa(Pa), and Serratia marcescens(Sm). This research carried out the results detecting five kinds of insect pathogen of P. b. seulensis by multiplex PCR. Multiplex PCR is effective and save time to detect simultaneously these insect pathogens and multiple infections to prevent insect disease. In our study, using multiplex PCR, we demonstrated that P. b. seulensis was frequently infected with S. marcescens and co-infected with M. anisopliae in more than 80% of cases, indicating that such an analysis can be useful for pathogen identification, especially if different pathogens produce similar symptoms.
The white-spotted chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae), is the one of the mass-rearing insects in Korea. Traditionally, it has been considered as a medicine for preventing liver-related diseases and suppressing cancer. In addition, this beetle was recently enlisted as a temporal food ingredient by Korean Ministry of Food and Drug Safety. As the economic importance of this beetle is growing, the suitable rearing conditions are needed for more detailed investigation. In this study, we compared three different temperature conditions – 25, 27.5, and 30°C – and the four combinations of two ingredients – soybean cake, and rice bran. With these treatments, the weight change of third instar larvae was tracked for ten weeks. Among three temperatures, 27.5°C was identified as the best temperature condition for rearing this beetle. Among four combinations of different ingredients, the addition of soybean cake made significant weight incensement for third instar larvae. Based on these results, we concluded that adding soybean cake at 27.5°C is the best rearing condition among 12 combinations of temperatures and feed ingredients. In addition, we observed the body weight was reduced when the larvae were closed to the pupation period. Therefore, we recommend that ca. seven weeks after third instar is the best time to distribute it to the market.
Multi-view system is one of the auto-stereoscopic displays that allows users to watch 3D images without wearing special glasses. Generating contents for the multi-view display system is often accomplished using Depth-image-based rendering (DIBR) intermediate view generation. DIBR-based intermediate view generation method reconstructs a 3D scene with a color image and depth map information. Then, a virtual camera is put in various view positions to capture intermediate view images. In this research, we tried to improve the quality of the DIBR-based intermediate views by applying non-uniform quantization method for depth map information. This paper describes the intermediate view generation process using DIBR. Then, it discusses the evaluation of multi-view intermediate images generated using uniform and non-uniform depth quantization methods. Finally, the paper describes the future direction and how the muti-view systems can be utilized in computer games.
목적: 20~71세 성인을 연령에 따라 5군으로 분류하여 연령에 따른 한국인의 고위수차 변화도를 알아보기 위하여 수행되었다. 방 법: 본 연구의취지에 동의한 사람가운데 전신질환이나 안질환이 없으며, 굴절이상 수술을 포함하여 안과 관련 수술병력이 없는 성인 290안을 대상으로 Pentacam을 사용하여 동공직경 5mm 범위에서의 총고위수차(HOA), 총구면수차(TSA), 총코마수차(TCA), 총트레포일수차(TTA)를 측정하였다. 결과: 전체 대상군의 전면 HOA의 Root-mean square(RMS)에 대한 평균값은 0.094±0.021㎛, 후면 HOA의 RMS에 대한 평균값은 0.022±0.004㎛ 이고, 전체 HOA의 RMS에 대한 평균값은 0.080±0.022㎛로 나타났다. 연령에 따른 HOA의 상관관계를 분석한 결과 전면수차는 연령과 유의한 상관관계(r=0.335, p < 0.0001)를 보였지만, 후면과는 유의한 상관관계(r=0.096, p=0.102)가 없는 것으로 나타났다. 전체 대상군의 전면 TSA의 RMS에 대한 평균값은 0.279±0.057㎛, 후면 TSA의 RMS에 대한 평균값은 0.057±0.017㎛ 이고, 전체 TSA의 RMS에 대한 평균값은 0.223±0.056㎛ 로 나타났다. 연령에 따른TSA의 상관관계를 분석한 결과 전면수차는 연령과 유의한 양의 상관관계(r=0.240, p < 0.0001)를 보였지만, 후면과는 유의한 음의 상관관계(r=-0.358, p < 0.0001)를 보였다. 전체 대상군의 전면 TCA의 RMS에 대한 평균값은 0.089±0.046㎛, 후면 TCA의 RMS에 대한 평균값은 0.024±0.012㎛ 이고, 전체 TCA의 RMS에 대한 평균값은 0.081±0.045㎛로 나타났다. 연령에 따른 TCA의 상관관계를 분석한 결과 전면수차는 연령과 유의한 양의 상관관계(r=0.118, p=0.04)를 보였고, 후면 또한 유의한 양의 상관관계(r=0.311, p < 0.0001)가 나타났다. 전체 대상군의 전면 TTA의 RMS에 대한 평균값은 0.042±0.035㎛, 후면 TTA의RMS에 대한 평균값은0.012±0.008㎛ 이고, 전체TTA의RMS에 대한평균값은0.041±0.032㎛로 나타났다. 연령에 따른 TTA의 상관관계를 분석한 결과 전면수차는 연령과 유의한 양의 상관관계(r=0.250, p < 0.0001)를 보였고, 후면 또한 유의한 양의 상관관계(r=0.149, p=0.011)가 나타났다. 결론: 한국인의 각막 고위수차 분석을 통하여 한국인 눈의 광학적 부분의 더 나은 이해를 제시하였으며, 현대인의 시력의 질을 향상시키기 위한 추가적인 연구에 활용될 수 있는 기초 자료로 활용 할 수 있을 것으로 사료된다.
This study was conducted to investigated the distribution and ecological character of Black Soldier Fly(BSF), Hermetia illucens, to determine effects of BSF on composing ability to waste-food. The distribution of BSF was defined in all parts of the country in Korea. Its main habitat was found to be areas near cattle sheds, manure sheds, living waste dump grounds, and food waste dump grounds.
Observed characteristics of BSF by developmental stage may be summarized as follows: eggs were a long oval shape of 886.9±19.7 ㎛ in major axis and 190.1±9.7 ㎛ in minor axis; they were 24.0±1.6 ㎍ in weight. One adult insect laid 1001±247 eggs in quantity; days to hatch from eggs (27℃, 60% R.H.) were 81.3±12.5 hours. Larvae which were hatched appeared to be close to white and turned into pale yellow as being last instar larva. Last instar larva ranged from 20.7±1.1 mm in size, the length of larval stage was approximately 15~20 days. Pupae exhibited red brown, 19.2±1.1 mm in size; pupal state lasted 15.5±1.4 days for female, 14.7±1.4 days for male, exhibiting the tendency of males having shorter period than females. Adult insects were sized about 13~20 mm and colored black.