Effects of the initial water curing time on the corrosion behavior of steel bar corrosion in fly ash concrete

AbstractConcrete specimens made of 30% fly ash (FA) replacement ratio and ordinary Portland cement (OPC) were fabricated to study the effects of the initial water curing time on the corrosion behavior of the embedded steel bar. The specimens were cured in water tank for 5days, 7days, 14days and 28days respectively at a normal temperature of 20□, then taken out and stored at an indoor natural environment. At the exposure time of 60days, 120days and 180days, steel bars' corrosion current densities icorr, corrosion potentials Ecorr in FA and OPC concrete specimens and their electrical resistivities ρc were tested. Results indicate that the initial wet curing time has important effects on steel bars' corrosion behaviors in both FA concrete and OPC concrete. With the increase of the initial wet curing time, steel bars' icorr all tend to decrease and Ecorr tend to increase. The longer the initial wet curing time, the higher the protective ability of FA concrete, compared to OPC concrete. Under the normal temperature, the shorter initial wet curing time of 5days and 7days for FA concrete showed worse protective ability than OPC concrete. However, when the initial wet curing time surpasses 14days, FA concrete behaves better than OPC concrete

Optimal design of passive power filters of an asymmetrical system based on genetic algorithm

AbstractHybrid power filter is effective equipment for preventing harmonic pollution and enhancing power quality. The design of passive power filters is one of the important parts of hybrid power filter. Conventional approaches for the design of passive power filters depend on the experiences and single technology criterions, which are difficult to achieve the optimal solution. An optimal design method based on genetic algorithm is proposed in this paper. Two objectives including minimum total harmonics distortion of current and minimum cost for equipments are constructed, and reactive power compensation is used as constraint condition. The objective functions for an asymmetrical powers system are deduced, thus the fitness functions are determined. And the parameters of passive power filters are achieved by adopting genetic algorithm. Passive power filters applied in practical system are designed and the simulation model is given. Simulation results show that the filter designed by the proposed algorithm has better harmonics suppression effect and lower initial investment for equipments than conventional approaches

Correlating Gravitational Waves with WW-boson Mass, FIMP Dark Matter, and Majorana Seesaw Mechanism

We study a minimal extension of the Standard Model by introducing three right-handed neutrinos and a new scotogenic scalar doublet, in which the mass splittings between neutral and charged components are responsible for the $W$-boson mass newly measured by the CDF collaboration. This model can not only generate non-vanishing Majorana neutrino masses via the interaction of right-handed neutrinos and scotogenic scalars, but also explain the Universe's missing matter in the form of FIMP dark matter. We also study the influence of the mass splitting on the first order electroweak phase transition, and find that it can further enhance the transition strength and thus induce gravitational waves during the phase transition, which may be detected in the forthcoming detectors such as U-DECIGO.Comment: References updated, accepted for publication in Science Bulleti

Lepton-flavored electroweak baryogenesis

We explore lepton-flavored electroweak baryogenesis, driven by CP-violation in leptonic Yukawa sector, using the τ−μ system in the two Higgs doublet model as an example. This setup generically yields, together with the flavor-changing decay h→τμ, a tree-level Jarlskog invariant that can drive dynamical generation of baryon asymmetry during a first-order electroweak phase transition and results in CP-violating effects in the decay h→ττ. We find that the observed baryon asymmetry can be generated in parameter space compatible with current experimental results for the decays h→τμ, h→ττ, and τ→μγ, as well as the present bound on the electric dipole moment of the electron. The baryon asymmetry generated is intrinsically correlated with the CP-violating decay h→ττ and the flavor-changing decay h→τμ, which thus may serve as “smoking guns” to test lepton-flavored electroweak baryogenesis

Lepton-flavored electroweak baryogenesis

We explore lepton-flavored electroweak baryogenesis, driven by CP-violation in leptonic Yukawa sector, using the τ−μ system in the two Higgs doublet model as an example. This setup generically yields, together with the flavor-changing decay h→τμ, a tree-level Jarlskog invariant that can drive dynamical generation of baryon asymmetry during a first-order electroweak phase transition and results in CP-violating effects in the decay h→ττ. We find that the observed baryon asymmetry can be generated in parameter space compatible with current experimental results for the decays h→τμ, h→ττ, and τ→μγ, as well as the present bound on the electric dipole moment of the electron. The baryon asymmetry generated is intrinsically correlated with the CP-violating decay h→ττ and the flavor-changing decay h→τμ, which thus may serve as “smoking guns” to test lepton-flavored electroweak baryogenesis

Colorectal cancer screening with fecal occult blood test: A 22-year cohort study.

The aim of the present study was to investigate the efficacy of colorectal cancer (CRC) screening with a three-tier fecal occult blood test (FOBT) in the Chinese population. The study was performed between 1987 and 2008 at the Beijing Military General Hospital, in a cohort of army service males and females aged >50 years. Between 1987 and 2005, a three-tier screening program, comprising guaiac-based FOBTs (gFOBTs), followed by immunochemical FOBTs for positive guaiac test samples and then colonoscopy for positive immunochemical test subjects, was performed annually. The cohort was followed up until 2008. The cohort included 5,104 subjects, of which, 3,863 subjects participated in screening (screening group) and 1,241 did not (non-screening group). The two groups did not differ in age, gender or other major risk factors for colon cancer. Overall, 36 CRCs occurred in the screening group and 21 in the non-screening group. Compared with the non-screening group, the relative risk for the incidence and mortality of CRC was 0.51 [95% confidence interval (CI), 0.30-0.87] and 0.36 (95% CI, 0.18-0.71), respectively, in the screening group. The general sensitivity of this three-tier FOBT was 80.6% (95% CI, 65.3-91.1). Thus, annual screening using the three-tier FOBT program may reduce the CRC incidence and mortality rate

Research Advances in the Refining of Polysaccharides and the Mechanism for Its Effect on Reducing the Toxicity and Enhancing the Efficacy of Cyclophosphamide

Anticancer chemotherapy with cyclophosphamide (CTX) is accompanied by toxic side effects such as bone marrow suppression and intestinal mucosal injury, which seriously affects the treatment tolerance and prognosis of patients. In recent years, polysaccharides have been used as detoxifying and synergistic adjuncts for antitumor drugs due to their anticancer, anti-inflammatory, and immunoregulatory activities. This paper systematically summarizes polysaccharide purification technologies, elaborates on the detoxification mechanism of polysaccharides on CTX from multiple perspectives such as immunomodulation, antioxidation, intestinal protection, liver and kidney protection, and reproductive system protection, and discusses the synergistic effect of polysaccharides with CTX by directly or indirectly killing tumors. Furthermore, the regulatory pathways of polysaccharides in cancer chemotherapy are summarized from two aspects: toxicity reduction and efficacy enhancement. We hope that this review could provide a reference for research on the mechanism of action of polysaccharides in reducing the toxicity and enhancing the efficacy of CTX, and provide new directions for reducing the toxic side effects of CTX

Placoneis modaomensis sp. nov. (Bacillariophyta; Cymbellaceae), a new species from Guangdong Province, China

One new species, Placoneis modaomensis, found in a freshwater environment from a tributary of the Pearl River, which lies in Modaomen Channel, Zhuhai County, Guangdong Province, China, is described based on light and scanning electron microscope observations. P. modaomensis sp. nov. has the morphological features that are typical for the genus, including external terminal raphe fissures curved to the opposite sides and areolae with internal volate occlusions. The new species is similar to P. amphibola (Cleve) E.J. Cox, P. amphiboliformis (Metzeltin, Lange-Bertalot & Soninkhishig) Vishnyakov, P. parvapolonica Lange-Bertalot & Wojtal, P. clementispronina Lange-Bertalot & Wojtal and P. nanoclementis Lange-Bertalot & Wojtal in the shape of the valves and in having coarse striae but it can be easily distinguished by the two main morphological characteristics: external central raphe endings bent in the opposite directions, and areolae covered by volate occlusions externally. The latter feature appears to be new for taxa assigned to the genus Placoneis. Data on the associated diatom flora and its ecology are also given. These findings increase our understanding about the morphology of Placoneis in general and the distribution of the genus in China