Experimental and Theoretical Investigations of the Constitutive Relations of Artificial Frozen Silty Clay

The strength and deformation characteristics of artificial frozen soils are quite sensitive to temperature, confining pressure, and water content. To investigate these effects, a series of triaxial compressive tests on frozen Harbin silty clay were conducted at temperatures of −5 °C, −10 °C, and −15 °C under different confining pressures and water contents. From the stress–strain curves under lower water content and confining pressure, strain–softening behavior was observed. The modified Duncan–Chang (MDC) model was employed to describe the constitutive relations of artificial frozen silty clay while considering the strain–softening effects. After introducing statistical damage (SD) theory, an SD constitutive model with the failure strain as a random variable was proposed, which is able to overcome the drawbacks of the MDC model. The predicted SD model results are found to be consistent with the experimental results

Sustainability of Reinforced Concrete Beams with/without BF Influenced by Cracking Capacity and Chloride Diffusion

Concrete’s production causes pronounced environmental impacts. It is confirmed that adding basalt fiber (BF) into concrete can improve the mechanical properties and reduce the chloride diffusion coefficient of concrete. Moreover, research on the environmental impact of BF and its application in concrete has gradually emerged in recent years. However, there is little research on the chloride diffusivity of concrete structures with BF under the coupling interaction of external loads and chloride action. Therefore, at first, six beams were cast to obtain the depth-dependent chloride diffusivity of concrete under the coupling interaction of chloride penetration and 50% and 80% of the cracking capacity. Then, a functional unit (FU) combining durability, cracking capacity and volume was proposed to evaluate the sustainability of the concrete structure. In addition, three extra FUs (volume, considering volume and cracking capacity simultaneously and considering volume, cracking capacity and durability simultaneously) were also proposed and compared with the first FU. Results indicate that, regardless of the applied load level, the average chloride diffusion coefficient of a reinforced concrete (RC) beam with BF is larger than that of an ordinary RC beam. Moreover, the sorting of life cycle assessment (LCA) results will vary significantly with the different preset functional units. When taking the cracking capacity into consideration, adding BF into concrete is a suitable solution to improve the sustainability of RC beams

Permeability of Concrete and Correlation with Microstructure Parameters Determined by 1H NMR

Water and gas permeability coefficients of concrete with different water-binder (w/b) ratios and admixtures were measured by a self-designed test device based on the steady-state flow method for liquid and the method of differential pressure in stability for gas, respectively. In addition, the micropore structure of concrete was determined by 1H nuclear magnetic resonance (NMR). Results indicated that there are good correlations between water and gas permeability of concrete with different w/b ratios, with correlation coefficient greater than 0.90. Better correlations between water permeability and segmental contributive porosity ranged from 10 to 100 nm and 100 to 1000 nm can be identified, but the gas permeability is more relevant to the segmental contributive porosity ranging from 100 to 1000 nm. Moreover, the correlation between water permeability and contributive porosity for each pore diameter is always better than that of gas permeability. The influence of admixtures on the relationship between permeability and pore size distribution of concrete is significant. Moreover, water permeability coefficient is one or two orders of magnitude lower than the gas permeability coefficient

The whole mitochondrial genome of Sarcophaga kanoi (Diptera: Sarcophagidae)

Sarcophaga kanoi Park, 1962, a widely distributed flesh fly in Southeast Asia, is important in forensic entomology. Notably, its mitochondrial genome could provide the unique and accurate molecular information in species identification which facilitate forensic practices in estimation of postmortem interval especially in putrefied cadaver cases. Thus, we sequenced and characterized the whole mitochondrial genome (mitogenome) of S. kanoi for the first time, which was collected from Southern China in this study. The 15,319 bp mitogenome contained 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA), 2 ribosomal RNA genes (rRNA), and a putative control region. The total nucleotide composition of this circular genome was 39.7% for A, 9.3% for G, 14.2% for C, and 36.8% for T. To better understand the genetic relationship, the phylogenetic analysis was constructed according to the 13 PCGs sequence of S. kanoi and other 11 species. The phylogenetic tree showed that the S. kanoi was placed in a sub-clade with S. similis. Our study updated the new genetic information for dipteran mitogenomes, which could broaden the background knowledge for forensic entomology, molecular genetics and developmental biology. It has the potential application on the species identification using genetic markers

The complete mitochondrial genome of Sarcophaga scopariiformis (Diptera: Sarcophagidae)

Sarcophaga scopariiformis (Diptera: Sarcophagidae), a potential vector of pathogens as well as one of the important flesh fly specie in forensic entomology. We have firstly sequenced and assembled the whole mitogenome of S. scopariiformis in this study. The circular mitogenome is 15,325 bp in length, consisting of A (39.3%), G (9.4%), T (36.8%), and C (14.5%). It showed in a typical mitochondrial genome similar to other sarcophagids species, which is composed of 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA), 2 ribosomal RNA genes (rRNA), and a non-coding AT-rich region. Moreover, the phylogenetic analysis based on 13 PCGs has been conducted. The topological structure of the phylogenetic tree clearly indicated that S. scopariiformis was more closed to the species of Sarcophaga peregrina in genetic distance, compared to the other sarcophagids species. This study provided a useful data reference for genetic structure and phylogenetic analysis of Sarcophagidae

A standalone incompatible insect technique enables mosquito suppression in the urban subtropics

A field trial in Changsha, China, involving the release of a triple Wolbachia-infected strain of the mosquito, Aedes albopictus, demonstrates the feasibility of using an incompatible insect technique to suppress disease vector mosquito populations in urban subtropic environments