RESUMO
In this paper, the structural performance of lap-spliced beams were investigated by the testing of 18-UHPFRC beams with and without a lap-spliced region and steel fiber. All test specimens were subjected to flexural load by using the four-point bending test. It was shown that test steel fiber inclusion in the ultra-high-strength matrix significantly increased the strength of the lap-spliced beams. The maximum strength of the specimen increased linearly with the increase in steel fiber volume fraction. The hybrid-type UHPFRC, with lower steel fiber volume fraction, using two types of steel fiber was effective in improving the bond strength. In order to verify the safety of lap splice length design methods by current code provisions and UHPFRC design recommendations, the average bond stress at the ultimate state was used to calculate the lap splice length, which makes reinforcement yielding, and this value, compared with design lap splice length. Most of the design equations were under the estimated bond stress of UHPFRC. However, the AFGC recommendation, which considers the tensile strength of UHPFRC, overestimates the bond stress of UHPFRC because this recommendation was developed from the direct pull-out test results.
RESUMO
A detailed description and illustrations of a new terebellid species are provided, and molecular information based on partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene are included. The new species, Neoamphitrite undevigintipes sp. nov., is described from the deep sea off the eastern coast of South Korea. It is similar to Neoamphitrite groenlandica (Malmgren, 1866) in that the thorax has 19 notopodial chaetigers. However, Neoamphitrite undevigintipes sp. nov. is clearly distinguishable from N. groenlandica in having the uncini of the first abdominal chaetiger arranged in a single row and in having 12 ventral shields. A taxonomic key to all known Neoamphitrite species is also included.
RESUMO
A new cirratulid species, Timareteposteria sp. n., is described from the intertidal habitats of the eastern coast of South Korea. The new species is closely related to Timareteluxuriosa (Moore, 1904) from southern California based on morphological similarity of the branchial and tentacular finalents and the noto- and neuropodial spines. However, T.posteria sp. n. differs from the latter based on the following characteristics: 1) evenly divided peristomium into three annulations; 2) 2-4 neuropodial spines originating in the posterior chaetigers alternated by a few capillaries; and 3) complete shift in branchial finalents located about one-third between the notopodium and the dorsal midline. The new species has a methyl green staining pattern (MGSP) distinct from other Timarete species. Detailed description and illustrations of the new species are provided with molecular information based on the partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (16S). This study also includes a key and discussion of known Timarete species from East Asia.
RESUMO
Two new cirratulid polychaetes of the genus Aphelochaeta collected from Korean waters are reported here along with detailed descriptions and illustrations. Aphelochaeta petila n. sp. is readily distinguished from its congeners by the following characteristics: non-expanded anterior and posterior ends of the body; non-moniliform segments in the abdomen; peristomium with three annulations and an indistinct dorsal crest; both the dorsal tentacles and the first branchiae attached on the peristomium; presence of only a pair of branchiae on chaetiger 1; and the ventrum of the thoracic region with transverse dark blue stripes on the chaetigers 6-16 with methyl green staining. Aphelochaeta intinctoria n. sp. is characterized by a combination of the following features: a rounded prostomium; a peristomium with a dorsal crest; a non-expanded thoracic region; dorsal tentacles on the peristomium and the first pair of branchiae on chaetiger 1; and the thoracic region lacking a distinct methyl green staining pattern. These two new species from Korean waters also differ in details of chaetal ultrastructure.
Assuntos
Distribuição Animal , Poliquetos , Animais , AnelídeosRESUMO
A new pectinariid polychaete, Lagis plurihamus sp. nov., is reported from intertidal habitats in the southern and western coasts of Korea. Lagis plurihamus sp. nov. is clearly distinguished from its congeners by a combination of the following morphological features: the cephalic veil bears usually 10-15 cirri; two pairs of thoracic branchiae are present on the segments 3 and 4; the scaphe is robust with 9-14 delicate scaphal hooks; the scaphal anal flap has a dorsal anal cirrus and fringed margin. Previously described species of Lagis from East Asia, L. bocki (Hessle, 1917) and L. crenulatus Sun & Qiu 2012 together with the newly described species L. plurihamus sp. nov., all have both short, recurved notochaetae with bordered serrations and long, straight notochaetae with fine serrations. We provide detailed description and illustrations with SEM photographs for the new species. A revised key to all Lagis species is also provided with a comparison of the morphological characteristics of them.
Assuntos
Poliquetos , Distribuição Animal , Estruturas Animais , Animais , Anelídeos , Tamanho Corporal , Ásia Oriental , Tamanho do Órgão , República da CoreiaRESUMO
The mitogenome sequence of the epitokous Nereis species (Phyllodocida, Nereididae) was determined first in the genus Nereis. The complete mitogenome is 15,667 bp in length, containing 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNAs and a control region, and their gene order and structure is identical to those of other nereidid species. The mitogenome consists of 33.5% A, 20.0% C, 13.3% G, 33.1% T, showing a high content of A + T similar to the other phyllodocid polychaetes. These results will be useful for inferring the phylogenetic relationships among the members of Nereididae within the phyllodocids.
RESUMO
Mitogenome sequence of Cirriformia cf. tentaculata (Terebellida, Cirratulidae), a species of marine polychaete worm, was determined in this study. This is the first mitogenome reported for genus Cirriformia and family Cirratulidae. This complete mitogenome is 15,495 bp in length, containing 13 protein coding genes (PCGs), two ribosomal RNAs (rRNAs), and 23 transfer RNAs (tRNAs). The mitogenome of Cirriformia cf. tentaculata has high A + T content of 59.5% (A, 29.5%; C, 26.9%; G, 13.6%; T, 30.0%). In neighbour-joining (NJ) analysis, Cirriformia cf. tentaculata is clustered with the components of order Terebellida.
RESUMO
A new eunicid species, Leodice duplexasp. n., from intertidal and subtidal habitats in the eastern coast of South Korea is described. The new species is assigned to the C-2 group, and is similar to Leodice antennata, the type species of the genus, in having the following combination of characteristics: moniliform antennae and palps, bidentate compound falcigers, articulated peristomial and notopodial cirri, pectinate branchiae showing bimodal distribution of branchial filaments, and yellow aciculae. However, L. duplexasp. n. is readily distinguished from L. antennata by the following features: the aciculae are 2-4 in number, with blunt or pointed tips and hammer-headed or bifid tips, and the subacicular hooks are paired in some chaetigers. A detailed description and illustrations are provided for the new species. The validity of the new species is also supported by a genetic comparison using sequences of the mitochondrial cytochrome c oxidase subunit I (COI). A revised key to known Leodice species is provided with a comparison of their morphological characteristics.
