This study shows the development of a photocatalytic technology for the road to decompose the nitrogen oxides(NOx) using a titanium oxide(TiO2) photocatalyst coating method for reducing the air pollution

The objective of this study was to evaluate the effectiveness of various crack inducers to be used in the advanced reinforced concrete pavement (ARCP) by conducting yard tests. Some of cracks are induced in ARCP to reduce the stresses in steel bars and to form more uniformly spaced cracks so that the required steel bar amount can be decreased and at the same time the pavement performance can be improved. In this study, an experimental ARCP was constructed for the length of 22.4 m, width of 1.12 m, and thickness of 0.26 m. The anchor lugs were placed at both ends of ARCP to pretend continuities of the system. 8 crack inducers with a uniform spacing of 2.8 m were installed in different manners when placing concrete, so the test length of the experimental ARCP was 19.6 m. The variables of crack inducers included the shape, material, installed depth, and installing method. The basic shape of the crack inducer represented a round face and a flat opposite face with a height of 50 mm and a width of 10 mm. The slightly different shaped crack inducers were installed for inducing cracks at both ends of ARCP. The crack inducers were primarily made of glass fiber reinforced plastic (GFRP) but a crack was induced using a polyethylene sheet inducer. The installed depths of the crack inducers were 30, 40 and 70 mm to the top of the crack inducer from the pavement surface. Most crack inducers were preinstalled on the transverse steel bar locations before concrete pouring, but 2 crack inducers were installed just after concrete placement when concrete was still fresh. The temperature measurement sensors of i-Buttons and thermocouples were installed at the top, middle and bottom of slab to measure the temperature variations of slab. The displacement transducers were also installed at the crack locations to measure the crack width movements. The experimental results showed that the cracks were induced at all the locations where the crack inducers were placed. In addition to the induced cracks, just one crack was formed naturally. The crack patterns on the surface of pavement were all comparable. The crack width measurement data showed that there were slight differences in the crack width movements among the cracks but all the cracks including both the induced and naturally formed cracks moved little within a 0.1 mm range. Therefore, any type of the crack inducers employed in this study can be used to initiate cracks in ARCP.

The ride quality (i.e. smoothness) is a key factor for evaluating the construction quality of expressway asphalt pavement. Conventionally, three paving devices are widely used to control the surface layer thickness: leveling sensor (i.e. LS), short-range-surfacing-contact-ski (i.e. SSCS) and long-range-surfacing-contact-ski (i.e. LSCS). However, each of these levelling tools presents one major drawback. In the case of LS, if the original sub-layer evenness is poor, the final asphalt pavement surface and its smoothness will be negatively affected. The SSCS cannot assure satisfactory smoothness when relatively long paving section (in the order of 10 km) are paved. While the LSCS would reduce the drawback of the SSCS, its weight on the one hand and its length on the other discourage its use in the paving site especially for curved sections. In this paper, a next generation pavement smoothness leveling equipment, known as non-contact-digital-ski (i.e. NCDS) was implemented, evaluated and compared to the conventional equipment leveling device. The international Roughness Index (IRI m/km) was measured on sections paved with and without NCDS and the results visually and statistically compared. In addition, for the same sections, the modulus of the pavement layers was computed and compared by means of Falling Weight Deflectometer (i.e. FWD). It was observed that when NCDS is used for asphalt pavement overlay of existing concrete pavement, significant improvement in IRI (i.e. IRI<1.0m/km) and consistently uniform elastic modulus could be achieved compared to the conventional levelling and paving method.

Road construction and maintenance of deteriorated pavement has been continued since industrialization. Demand for aggregate with a good quality has been increasing from limited resources, but it is difficult to supply aggregates smoothly due to environmental protection regulations (Jo et al., 2015). Accordingly, efforts are being made in the road construction industry to utilize industrial products for the purpose of efficient use of resources and environmental preservation. Steel slag which contains a non-reactive CaO is used primarily as a material for embankment and soil covering depending on the expansion and environmental issues. On the other hand, steel slag shows a variety of performance improvements as including increased elasticity factors, increased indirect tensile strength, and improved plastic deformation resistance when handling the expansion issue with sufficient aging processing (Ali et al., 1991, Asi et al., 2007). In this study, the behavior characteristics of the slag asphalt concrete mixture were analyzed according to temperature to encourage the use of steel slag aggregate. Specimens with steel slag showed a higher initial strain than those with natural aggregates. But strain of specimens were nearly similar over the repeated temperature changes. The experimental results for specimens with these characteristics were less likely to cause the performance problems from temperature because the measured strains were relatively small than strain caused from other loads. In conclusion, it is necessary to design and construction process reflecting the behavior characteristics according to temperature to encourage the use of steel slag aggregate.

A number of roller-compacted concrete pavements (RCCP) have been constructed without saw-cut joints in order to save construction cost. Then it will allow natural cracks to randomly occur at the early age after concrete placement. Crack spacing of unjointed RCCP is crucial to ensure an adequate crack width and load transfer across the cracks since large crack spacing will result in excessive crack width and reduce load transfer efficiency that may be cause faulting, excessive deflection, and further cracking in RCCP slab. Due to pavement thickness, climatic condition, and material properties, unjointed RCCP may have different natural crack spacing. In this study, an analytical approach to predict natural crack spacing of an unjointed RCCP was developed. An analytical method based on elastic theory to calculate axial restraint stress using a bilinear slab-subbase interfacial constraint assumption was conducted. Curling stress induced by temperature gradient through the depth of the slab was also considered. The analytical model incorporates the environmental effect, strength gain and modulus of elasticity, coefficient of thermal expansion, drying shrinkage, base type materials, and slab geometries. The predicted crack spacing results obtained from the predictive model were validated through field measured data. The results showed a good agreement compared with crack spacing measured in the field. Furthermore, the result from a sensitive analysis using proposed predictive model showed that crack spacing increased when thickness of RCCP increased. The predicted crack spacing results may be used as input parameters to estimate crack widths in unjointed RCCP under given climatic condition, and material properties. If estimated crack width is excessive and cannot maintain an adequate load transfer across the cracks, saw-cut joints with an appropriate spacing should be provided in order to minimize crack width, and to prevent future cracking of RCCP leading to better performance.

Purpose：Conventional pre-saturation pulse for suppressing venous signals cannot be applied to time-of-flight magnetic resonance angiography(TOF-MRA) at 7 Tesla MRI due to specific absorption rate(SAR) limitation. The SAR could be attenuated with using low saturation flip angle, but a few repetitions are needed to reach signals below the steady-state signal of the brain tissues. The purpose of this study was to suppress venous system with clinically acceptable acquisition time by using 90 degree flip angle. Methods：The standard slab-selective radio-frequency and gradient waveform were modified to new-shaped models by minimum-time variable-rate selective excitation(Min-VERSE) algorithm. Excitation slice profile was measured and evaluated by a phantom scan. In volunteer measurement, the vessel-tissue contrast ratio of the sinuses(VTCR_S) and middle cerebral artery(VTCR_MCA) were assessed in correlation to surrounding tissue and compared to the values measured by the conventional TOF(cTOF) pulse sequence. Results：The experimentally-measured profiles showed that there was good agreement between conventional and modified pulse. The total scan time was 5 min 55 sec(Min-VERSE 90 FA, TR 28 ms) and 8 min 50 sec(90 FA, TR 42 ms). The quantitative results of ROI analysis were nearly similar, except the venous signal and VTCR_S at Min-VERSE 90 FA. Conclusions：We have presented that the use of Min-VERSE with high flip angle was useful. The total acquisition time was faster about 3 minutes and the signal analysis was hardly different to the values acquired by the values of 90 FA at cTOF. Since 7T MRI has been suitable for ultra-high resolution imaging, our protocol would be used by default for diagnosing various intracranial vascular pathologies.

The fruit house fly Atherigona orientalis (Schiner), which is belonging to Muscidae, Diptera, is classified as quarantine pest and first reported in Korea at 2016. Annual occurrence and spatial distribution pattern of A. orientalis was biweekly monitored from April to December, using fly-wine trap in Korea. A. orientalis was first found in Gwangyang in June and increased populations by September, 2017. It is considering that A. orientalis is difficult to survive during winter season because this species is belonging to non-diapausing insect, so it may possible to be overwintering in warm place such as green house of paprika and tomato during winter. Based on this survey, A. orientalis is considered to be excluded from quarantine pests.

A colony of Solenopsis invicta was first intercepted on Gamman pier, Pusan port in Korea at September, 2017 by Animal and Plant Quarantine Agency. The mitochondrial DNA (mt-DNA) of workers was analyzed and compared with vary libraries of mt-DNA haplotypes to elucidate the origin of the introduced colony with the trade pattern of the Gamman pier. The mt-DNA fragment of 768 bp, which is part of the Cytochrome oxidae I gene, was amplified and sequenced. The results showed that the mt-DNA was in the clade of haplotype 5, which is endemic in southern USA, China, Taiwan, and Australia. More than 60% of containers are imported from China into Gamman pier, it may be possible to assume that the colony was inadvertently invaded through containers from China.

Recently a colony of Solenopsis invicta, the red imported fire ant (RIFA), was intercepted on Gamman pier, Pusan port in Korea by Animal and Plant Quarantine Agency. It has been generally known that RIFA has two social forms as monogyne and polygyne, which showing the behavioral differences between the two forms and dictated by a pheromone binding protein, Gp-9. The social forms of the RIFA colony was revealed as polygyne form, when the GP-9 gene was analyzed by three allelic discrimination assays including Real-Time PCR (RT-PCR), rh-Amp SNP Genotyping, and peptide nucleic acid probe-based RT-PCR in this study.

Thrips setosus Moulton, 1928 (Thysanoptera: Thripidae), one of the Tospovirus vectors, was found at a commercial greenhouse in Korea. It damaged to leaves of hydrangea (Hydrangea macrophylla). The thrips widely distributes in Japan, being regarded as its origin. Recently, it invaded in Europe such as the Netherlands, France, and Germany. Unlike Japan, it was found on Hydrangea plants in European countries. In Korea, the thrips was recorded in 1974 by Woo. However, examination of voucher specimens reveals that the record is not true. According to the collection data since 2000, its distribution in Korea is rarely limited in Jeonbuk and Jeju. For identification, representative morphological characteristics and COI barcoding results are provided with possibility of introduction from Europe.

The subfamily Nitidulinae in Korea is reviewed with a pictorial key to species. In total, 30 species of 18 genera are recognized including three newly recorded genera, each with one species respectively: Nitidula rufipes (Linnaeus, 1767), Stelidota multiguttata Reitter, 1877 and Hebasculinus japonus (Reitter, 1877). Pictorial key to tribes, genera and species with illustrations of habitus are provided.

The genus Microrhagus Dejean, 1833 is reviewed with four species from Korea: Microrhagus foveolatus (Fleutiaux, 1923), Microrhagus jejuensis sp. nov., Microrhagus mystagogus (Fleutiaux, 1923), and Microrhagus ramosus Fleutiaux, 1902. Herein, we provide a key to species of Korean Microrhagus, with diagnoses and photographs for each species.

Two species of the genus Coccura Šulc, 1908 from Korea are reviewed. Coccura convexa Borchsenius, 1949 and C. suwakoensis (Kuwana and Toyoda, 1915) were recorded from North Korea by the report of Danzig (1980). Although Kwon et al. (2003) described Coccura comari (Kunow, 1880) from South Korea, we found that this species was misidentification of C. suwakoensis. In this study, we suggest that Coccura comari (Kunow, 1880) is to be excluded from the Korean fauna. The occurrence of C. suwakoensis is also recorded from South Korea for the first time, based on the additional populations which were heavily infested on the Chinese fingetree, Chionanthus retusus Lindley and Paxton. A key to the species of Coccura known from Korea is provided with diagnoses and photographs.

The Lucid technology as an interactive fully illustrated identification tool, has developed and assisted in the diagnosis of agricultural and quarantine pests and invasive organisms over the past years. In this study, lepidopterans specifically relating to quarantine pests were selected for a lucid key development based on the border inspection data from 1996 to 2016 in South Korea. They belong to four families: Sphingidae, Noctuidae, Pyralidae and Crambidae, and also categorize into the three groups: regulated, potential regulated and non-quarantine pests. The key includes diagnostic characters from head, thorax, fore- and hind-wings for each species examined.

Nomenclatural changes are provided for Sorbus-feeding Cacopsylla moiwasana (Kuwayama, 1908) species group. Thirteen Palaearctic Cacopsylla species have been recorded from Sorbus L. (Rosaceae), and of these, seven species restricted to East Asia. Among the East Asian species, four Japanese species, i.e. C. elegans Inoue, 2004, C. jezoensis (Miyatake, 1963), C. midoriae (Miyatake, 1963) and C. moiwasana (Kuwayama, 1908), assigned to C. moiwasana species group. Above the latter three species very similar to each other, allopatrically distributed, and all or some of them could be synonymous. The present investigation of the type material resulted in confirmation that Psylla jezoensis and P. midoriae should be treated as junior synonym of P. moiwasana. The following synonyms are proposed: Cacopsylla moiwasana (Kuwayama, 1908) = Psylla jezoensis Miyatake, 1963, syn. nov., Psylla midoriae Miyatake, 1963, syn. nov. The species are newly recorded from Korea.

Modern technique development provides a new opportunity to expand entomological researches. Aerial insect sampling has been conducted with fixed-wing unmanned aerial vehicles (UAVs). With improved maneuverability, rotary-wing UAVs can serve as more convenient and feasible tools with lower cost. A rotary-wing UAV with remotely controlled insect nets was developed to collect insects at designated altitudes above the rice field (ca. 80 × 240 meter (width × length)) in Boryeong, South Korea. From 21 flights in June, July, and August 2017, 235, 7, 6, and 3 insects were caught at 5, 10, 50, and 100 meters above the rice field, respectively. The collected insects were identified to family level. Diptera (Phoridae and Chironomidae), Hemiptera (Aphididae and Delphacidae), and Thysanoptera were found from the sample, some of which may contain possible insect pests on rice. Therefore, UAVs have potential as an alternative aerial insect sampling method.