Cement is widely used as representative industrial material. In Korea, about 50 million tons of cement are consumed every year. In the manufacture of cement, raw materials containing NORM such as fly ash and bauxite are used. Therefore, the workers can be subjected to radiation exposure. The major exposure pathway in NORM industries is internal exposure due to inhalation of aerosol. Internal radiation dose due to aerosol inhalation varies depending on physicochemical properties of the aerosol. Therefore, the objective of this study was to investigate aerosol properties influencing inhalation dose in cement industries. In this study, aerosol properties were measured for two cement manufacturers. A particulate size distribution and concentration at various processing areas in cement manufacturing industries in Korea were analyzed using a cascade impactor. The mass density of raw materials and byproducts were measured using pycnometer. Shape of particulates was analyzed using SEM. The radioactivity concentration of Ra-226, Ra-228 for U/Th decay series was measured using HPGe. Particulate concentration by size was distributed log-normally with maximum at particle size about 7.2 μm in manufacturer A and 5.2 μm in manufacturer B. The mass density of fly ash and cement were 2.3±0.06, 3.2±0.02 g/cm3 respectively in manufacturer A. In manufacturer B, the mass density of bauxite and cement were 3.4±0.02, 2.9±0.01 g/cm3 respectively. The shape of particulates appeared as spherical shape in manufacturer A and B regardless of sampling area. Thus, a shape factor of unity could be assumed. The radioactivity concentrations of Ra-226, Ra-228 were 82±9, 82±8 Bq/kg for fly ash, and 25±4, 23±3 Bq/kg for cement in manufacturer A. In manufacturer B, the radioactivity concentrations of Ra-226, Ra-228 were 344±34, 391±32 Bq/kg for bauxite, and 122±13, 145±12 Bq/kg for cement. The radioactivity concentrations of Ra-226, Ra-228 in cement were less than raw materials such as fly ash and bauxite. It is because the dilution of the radioactivity concentration occurred during mixing with other raw materials in cement production process. This study results will be used as database for accurate dose assessment due to airborne particulate inhalation by workers in cement industries.

총담관류는 담관낭종 중 가장 빈도가 낮은 질환으로 악성 종양 발생에 대한 보고가 드물어 총담관류로 인한 악성 발생 가능성에 대해서 이견이 존재한다. 저자들은 상부위장관 검진에서 우연히 발견된 십이지장 유두부 선종으로 내원한 환자에서 내시경 초음파를 이용하여 총담관류 내에서 발생한 선종으로 진단 후 올가미를 이용한 내시경 유두절제술을 통하여 완전절제에 성공한 증례를 경험하였다. 이에 총담관류 내 악성 종양 발생 가능성 및 총담관류의 진단과 내시경적 치료에 대한 문헌 고찰과 함께 보고하고자 한다.

To control an external parasitic mite, a honey bee line possessing high hygienic behavior (HHB) against an external parasitic mite, Varroa destructor, has been bred in South Korea and an assessment method has been necessitated to diagnose HHB line from the low hygienic behavior (LHB) line. Thus, in this study, we developed single nucleotide polymorphism (SNP) markers from whole genome sequencing of each 20 worker bees from HHB and LHB lines of A. mellifera ligustica (Hymenoptera: Apidae). An average of 319,445,977 sequence reads was mapped to the known A. mellifera reference genome (an average of 87.46%). In 2,316,128 and 3,266,756 SNPs from each HHB and LHB line, an average of 93.6% and was located in the intergenic spacers and introns, whereas, the remaining 6.4% was located in the genic region, respectively. Among them 20 SNPs that were fixed at each line possessing within-individual homozygosity were selected and each four SNPs were used to diagnose the two honey bee lines either by typical PCR-restriction fragment length polymorphism method or allele-specific PCR. The remaining six SNPs had the size difference, enabling relatively easy differentiation between the two honey bee lines on typical agarose gel and another remaining six SNPs only has sequence difference including SNP sites. Thus, these SNP markers can be used to diagnose the honey bee line with HHB from LHB line against V. destructor.

Pavement performance usually depends on the pavement’s material property, traffic and environmental conditions. Current pavement design programs such as the Mechanistic Empirical Pavement Design Guide use these factors in assessing the pavement life and performance in terms of different distresses like rutting and fatigue cracking. Theoretically, the cracking and rutting behaviour of pavements are based on accumulated strains experienced by the pavement which is brought by the weight and loading speed of vehicles. A steady state loading device was used in the field to evaluate pavement deflection’s behaviour in varying loading frequencies. It was observed that the pavement deflection increases as the loading frequency also increases until it approaches a certain frequency wherein the deflection decreases thereafter. In this study, a three-dimensional finite element pavement model was established using ABAQUS wherein the effect of the vehicle’s loading frequencies was analysed. The calculated static deflection and stress from the finite element (FE) model were found to have good correlation with the KENPAVE measured deflection and stress. The deflections of different pavement conditions were further studied and analysed by generating several pavement geometries and strength from the FE model using a frequency sweep response analysis. It was found that the geometric condition and the current modulus of the pavement can amplify the pavement deflection by a factor, β, depending on the loading frequency. The peak deflection was found to be occurring when the loading frequency approaches one of the pavement’s natural frequencies. Based on the finding from this study, the natural frequency is an important factor to be considered in designing pavements. Further study is recommended to understand more on how to minimize the effect of natural frequency to pavement life.