Biofouling characteristics in Xinghua Bay of Fujian, China

Biofouling is one of the main factors affecting the efficiency and safety of cooling water systems in coastal nuclear power plants. Understanding the population dynamics, succession rules and cumulative effects of major fouling organisms is the basis for targeted prevention and control. A 1-year simulated concrete panel test was conducted from December 2020 to November 2021 in Xinghua Bay, China. A total of 78 species of fouling organisms were recorded by combining the monthly, seasonal, semiannual, annual and monthly cumulative panels, and the community composition was dominated by nearshore warm-water species, making for a typical subtropical inner bay-type community. The fouling organisms had a peak attachment period from June to October. Significantly more attachment was observed during summer (from June to August) than during the other three seasons. The attachment amount in the second half-year (from June to November) was much higher than that in the first half-year (from December to May). The attachment thickness, density, and biomass of the bottom summer panels reached 20 cm, 105,150 ind./m2, and 19,274.50 g/m2, respectively, while those of the bottom annual panels were 40 cm, 27,300 ind./m2, and 17,762.50 g/m2, respectively. The dominant fouling organisms with calcified shells mainly included Amphibalanus reticulatus and Pernaviridis. These species had high attachment amounts,could accumulate attachments for a long time, and even might cause secondary blockage, making them the most detrimental to the safety of a cooling system. Moreover,the seasonal upward growth of hydroids and bryozoans can also significantly reduce the efficiency of cooling water intake. We suggest that targeted prevention and control should be carried out according to the larval attachment period of different dominant groups of fouling organisms during June-October, which can greatly improve the prevention and control efficiency. Strengthening the research on the biological cycle phenomenon of the main species and their main environmental impact factors, and establishing a scientific and effective early-warning model are the governance direction of formulating and implementing scientific pollution prevention and control in the future

An ENU-Induced Mutation of Nrg1 Causes Dilated Pupils and a Reduction in Muscarinic Receptors in the Sphincter Pupillae

BACKGROUND: N-ethyl-N-nitrosourea (ENU)-induced mutagenesis is a powerful tool for the study of gene function and the generation of human disease models. A large number of mouse mutants obtained by ENU-induced mutagenesis with a variety of phenotypes have been recovered. However, after genetic confirmation testing, only approximately 50% of the abnormal phenotypes were found to be heritable. METHODOLOGY/PRINCIPAL FINDINGS: A mouse mutant, Dp1, with a dilated pupil phenotype was induced with an N-ethyl-N-nitrosourea (ENU) mutagenesis strategy. Sequence analysis for Nrg1 reveals a G>A base substitution that flanks exon E59, encoding for an EGFβ domain, in the 5' splice donor site. The mutation affects but does not abolish the splicing of EGFβ-type Nrg1 mRNA in Dp1 mice and produces several different transcripts by activating other, cryptic splice sites. These types of protein isoforms are expected, and the result shows that, in the mutant, the effect is a decrease in but not an elimination of the high affinity EGFβ-type Nrg1 isoforms. This is partially compensated for by an increase in expression of the low affinity alpha forms or inactive proteins, suggesting that the mutation results in a hypomorphic allele. Interestingly, genetic model testing shows that Dp1 is a mutation that results in a dilated pupil phenotype that is inherited with very low penetrance when heterozygous and with complete penetrance when homozygous. Pharmacological and immunohistochemical tests show a reduction of muscarinic (M) receptors in the sphincter pupillae of Dp1 mice, which is a major cause of dilated pupils. CONCLUSIONS/SIGNIFICANCE: This study is the first report of an Nrg1 mutation being associated with a dilated pupil phenotype and the reduction of M receptors. This report may help in establishing more mutant mouse lines and models of human genetic disease and can be applied to other organisms. Dp1 mice are a valuable resource for the further clarification of Nrg1 biological function

Organic concentrate from municipal solid waste as a renewable resource for liquid bio-energy production

Organic concentrate from municipal solid waste obtained from an autoclave separation process were used to carry out fermentation, gasification and pyrolysis to assess their potential for renewable energy production. Fermentation was a very promising process, where maximum enzymatic hydrolysis conversion of 53% of the cellulose and hemi-cellulose was found using a particle size range of 150-300 um hydrolyzed in a 100 ml buffer solution containing 6 per cent summer OC sample with 90 mg cellulase at pH 4.8 held at 40°C for 12 hours. The findings indicate that 152 L of ethanol could be obtained from a ton of the summer OC sample (Li et al., 2011b). The gasification experiment indicated a 1:1 ratio of H2: CO produced at 800°C using diluted air with steam. Pyrolysis of the summer OC sample was carried out using a bench-scale fluidized bed reactor at 350-540 °C comparing AI203 with activated olivine sand as bed materials. A maximum oil yield of 50% was obtained using the activated olivine sand at 400°C while only 45% was obtained at 500 °C using A1203• The calorific value of the bio-oil at 500°C was 29 MJ/kg using activated olivine sand while the blo-oil using AI203 was 23 MJ/kg. The blo-oils using activated olivine sand at 400°C were less aromatic and contained less nitrogen compared to the oils obtained using AI203 at 400°C (Li et al., 2011a). In addition, a bench-scale fixed bed reactor was used to carry out pyrolysis of the summer OC samples at 460-540 °C and a maximum oil yield of 44% was obtained at 500°C with a reaction time of 60 minutes. In conclusion, the MSW OC samples obtained from Estech have great potentials to be used as a renewable resource.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Design of automatic oxygen supply system of refuge chamber

In view of problem that most of existing oxygen supply systems of refuge chamber applied multistage protection system, and oxygen supply subsystems are independent of each other and cannot automatically switch among them, which causes the oxygen supply unstable, an automatic oxygen supply system of refuge chamber based on PLC and PID monitoring technology was designed. The system integrates multistage oxygen supply systems and environment parameters monitoring system through loop optical fiber system. Based on the detected environment parameters in real-time, and uses PLC and PID monitoring technology, the system can realize intelligent adjustment between all levels of oxygen supply system and automatic continuous supply oxygen of underground refuge chamber, and can automatically switch to the next level of oxygen supply system when a certain level of oxygen supply system happens failure, which improves stability and safety of the oxygen supply of refuge chamber. The site test results verify reliability of the system

Symmetric positive solutions for fourth-order n-dimensional m-Laplace systems

Abstract This paper investigates the existence, multiplicity, and nonexistence of symmetric positive solutions for the fourth-order n-dimensional m-Laplace system {ϕm(x″(t)))″=Ψ(t)f(t,x(t)),0<t<1,x(0)=x(1)=∫01g(s)x(s)ds,ϕm(x″(0))=ϕm(x″(1))=∫01h(s)ϕm(x″(s))ds. $$\left \{ \textstyle\begin{array}{l} \phi_{m}(\mathbf{x}{''}(t))){''}=\Psi(t)\mathbf{f}(t,\mathbf{x}(t)), \quad 0< t< 1,\\ \mathbf{x}(0)=\mathbf{x}(1)=\int_{0}^{1}\mathbf{g}(s)\mathbf{x}(s)\, ds,\\ \phi_{m}(\mathbf{x}{''}(0))=\phi_{m}(\mathbf{x}{''}(1))=\int _{0}^{1}\mathbf{h}(s)\phi_{m}(\mathbf{x}{''}(s))\,ds. \end{array}\displaystyle \right .$$ The vector-valued function x is defined by x=[x1,x2,…,xn]⊤ $\mathbf {x}=[x_{1},x_{2},\dots,x_{n}]^{\top}$, Ψ(t)=diag[ψ1(t),…,ψi(t),…,ψn(t)] $\Psi(t)=\operatorname{diag}[\psi_{1}(t), \ldots, \psi _{i}(t), \ldots, \psi_{n}(t)]$, where ψi∈Lp[0,1] $\psi_{i}\in L^{p}[0,1]$ for some p≥1 $p\geq1$. Our methods employ the fixed point theorem in a cone and the inequality technique. Finally, an example illustrates our main results

Statistical Downscaling and Projection of Future Air Temperature Changes in Yunnan Province, China

The SDSM was employed for downscaling of daily mean temperature of 32 meteorological stations (1954–2014) and future scenarios were generated up to 2100. The data were daily NCEP/NCAR reanalysis data and the daily mean climate model outputs for the RCP2.6, RCP4.5, and RCP8.5 scenarios from the MRI of Japan. Periodic features were obtained by wavelet analysis. The results showed the following. (1) The pattern of change and the numerical values of the air temperature could be reasonably simulated, with the average R2 between observed and generated data being 0.963 for calibration and 0.964 for validation. (2) All scenarios projected increases of different degrees of temperature in all seasons, except for spring in the 2020s. Annually, the most remarkable changes in the 2020s, 2050s, and 2080s were 0.27, 1.00, and 1.84°C, respectively. Seven dominant periods appeared under RCP4.5 and RCP8.5 from 1954 to 2100; however, an additional period appeared under RCP2.6. (3) In future periods, especially the 2020s, decreases in temperature were significantly located in the center of Yunnan under all three scenarios, whereas there were distinct increases in northwest and southeast Yunnan in most future periods. Besides, the RCP8.5 scenario showed the greatest increase in the 2080s