To attain superior fire safety epoxy resins (EP), aluminum diethylphosphonate (AlPi) and nickel alginate were incorporated to EP in different proportions. The synergistic flame retardant effects ...between AlPi and nickel alginate on fire safety and mechanical properties of EP were investigated in detail. EP/AlPi9.5‐Nickel Alginate0.5 acquired the UL‐94 V‐0 rating with the highest limiting oxygen index value (28.9%). Besides, the thermal decomposition behaviors of the samples were researched by thermogravimetric analysis, implying that EP/AlPi‐Nickel Alginate exhibited the better thermal stability and char‐forming ability. Compared with EP, the peak heat release rate and total heat release were declined by 58.3% and 12.8%. And the addition of nickel alginate reduced the release of smoke. In particular, the incorporation of AlPi and nickel alginate increased the impact strength, flexural strength and glass transition temperature of EP. In perspective, the synergistic effect of bio‐based nickel alginate and AlPi opens a practicable avenue in decreasing the fire risk and improving the mechanical properties of EP.
In this paper, we propose a novel transactive energy trading (TET) framework to deal with the economic issues in energy trading and the technical issues in distribution system operation in a holistic ...manner. In particular, we innovatively integrate a bilateral energy trading mechanism with the optimal power flow (OPF) technique to increase economic benefits to individual participants, and meanwhile ensure the reliability and security of the system operation. In order to resolve the inherent conflict of interests, Nash bargaining theory is used to model the TET problem, which is further decomposed into a multiperiod OPF problem and a payment bargaining problem. Moreover, we develop an efficient distributed algorithm for solving the TET problem base on alternating direction method of multipliers (ADMM). Instead of directly solving optimization subproblems like most ADMM-based distributed algorithms, we derive closed-form solutions to all subproblems to significantly improve the computational efficiency. Finally, numerical tests on the IEEE 37-bus and 123-bus distribution systems demonstrate the effectiveness of our proposed framework and the efficiency of our distributed algorithm.
AbstractObjectiveTo study the clinical characteristics of patients in Zhejiang province, China, infected with the 2019 severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) responsible for ...coronavirus disease 2019 (covid-2019).DesignRetrospective case series.SettingSeven hospitals in Zhejiang province, China.Participants62 patients admitted to hospital with laboratory confirmed SARS-Cov-2 infection. Data were collected from 10 January 2020 to 26 January 2020.Main outcome measuresClinical data, collected using a standardised case report form, such as temperature, history of exposure, incubation period. If information was not clear, the working group in Hangzhou contacted the doctor responsible for treating the patient for clarification.ResultsOf the 62 patients studied (median age 41 years), only one was admitted to an intensive care unit, and no patients died during the study. According to research, none of the infected patients in Zhejiang province were ever exposed to the Huanan seafood market, the original source of the virus; all studied cases were infected by human to human transmission. The most common symptoms at onset of illness were fever in 48 (77%) patients, cough in 50 (81%), expectoration in 35 (56%), headache in 21 (34%), myalgia or fatigue in 32 (52%), diarrhoea in 3 (8%), and haemoptysis in 2 (3%). Only two patients (3%) developed shortness of breath on admission. The median time from exposure to onset of illness was 4 days (interquartile range 3-5 days), and from onset of symptoms to first hospital admission was 2 (1-4) days.ConclusionAs of early February 2020, compared with patients initially infected with SARS-Cov-2 in Wuhan, the symptoms of patients in Zhejiang province are relatively mild.
•Recent advances using alginates in flame-retardant fields are reviewed.•Flame retardancy and pyrolysis behaviors of alginates are discussed in depth.•Outlooks of flame-retardant applications of ...alginates are provided.
Alginates, a kind of naturally occurring polysaccharides, have been exploited for functional materials owing to their versatility, sustainability, nontoxicity, and relatively low cost. Inherent flame retardancy is one of the most attractive features of alginates, as it enables the high-value-added utilization of alginates for eco-friendly flame-retardant materials. Now, the influence of metal ions on the flame retardancy and pyrolysis behaviors of alginates has been systematically studied; besides, the applications of alginates for flame-retardant materials have been greatly developed, such as for preparing flame-retardant fibers, fabrics, aerogel composites, and foams, as well as serving as a component or modifier of functional coatings, hybrids, and additives. This review will give an overview of the recent progress and the prospects of using alginates in flame-retardant fields, which can guide the design of bio-based flame retardants and benefit the further development of more diverse applications of alginates.
A balance of sustainability and high fire resistance and smoke suppression is important for the preparation of epoxy resins (EPs). Herein, bio-based iron alginate was used to ameliorate the fire ...safety of EP matrix. The addition of iron alginate reduced the initial decomposition temperature and temperature at maximum weight-loss rate of EP matrix, whereas obviously improved the char residues at the higher temperature zones. The peak heat release rate, smoke production rate and total smoke production were dramatically decreased by 61.3%, 60.4% and 42.2%, respectively, compared with those of EP matrix. And the presence of iron alginate obtained obviously smoke-suppressant effect on EP/iron alginate composites. Furthermore, the incorporation of iron alginate had no seriously destructive effect on the mechanical properties of EP matrix, while EP/iron alginate-3 exhibited a 13.5% improvement in the impact strength, compared with that of EP matrix. Such desirable features including higher fire resistance and proper smoke suppression make iron alginate a significant strategy for producing fire-safety EP compositions.
Adoptive therapy with cytomegalovirus (CMV)‐specific cytotoxic T lymphocytes (CMV‐CTLs) has emerged as an effective method for CMV infection. However, the efficacy reportedly ranges from 50% to 90%, ...and factors affecting anti‐CMV efficacy have not been established. We investigated the safety and efficacy of adoptive therapy with CMV‐CTLs for CMV infection in 190 patients after haploidentical stem cell transplantation (haplo‐SCT), and importantly, we analyzed the main factors affecting antiviral efficacy. The CMV peak titer decreased from 19 (range, 1.0–503.0) × 103 copies/mL to 3.9 (range, 0–112) × 103 copies/mL after CMV‐CTL infusion. The cumulative complete response (CR) rates in the first, fourth, and sixth weeks after the first CMV‐CTL infusion were 37.9% (95% CI 35.0–40.8), 76.8% (95% CI 70.7–82.9), and 89.5% (95% CI 85.2–93.8), respectively. In multivariate analysis, persistent CMV infection prior to CMV‐CTL infusion (hazard ratio HR 2.29, 95% CI 1.29–4.06, p = .005) and basiliximab treatment within 2 weeks of CMV‐CTL infusion (HR 1.87, 95% CI 1.06–3.81, p = .031) were independent predictors of poor antiviral efficacy of CMV‐CTL therapy. Our data showed that adoptive therapy with CMV‐CTLs is a safe and effective treatment for CMV infection after haplo‐SCT. Persistent CMV infection and basiliximab treatment are correlated with poor anti‐CMV efficacy of CMV‐CTL therapy.
Iron alginate is chosen as an eco‐friendly synergist to improve the flame retardancy, smoke suppression, and mechanical properties of epoxy resin/ammonium polyphosphate composites (EP/APP). The ...suitable additive amount of iron alginate further enhances the char‐forming ability in the higher‐temperature range and flame retardancy of EP/APP. EP/APP9.0‐iron alginate1.0 retains a char residue of 33.3% at 700 °C and obtains a limiting oxygen index value of 28.4% and vertical burning test (UL‐94) V‐0 rating, while EP/APP10 has no UL‐94 rating. The burning behaviors of EP/APP9.0‐iron alginate1.0 are also suppressed; and the total smoke production value is much lower than that of EP/APP10. EP/APP9.0‐iron alginate1.0 releases less smoke and flammable fragments. The suitable additive amount of iron alginate boosts the mechanical properties of EP/APP, while APP destroys the mechanical properties of EP. Therefore, the addition of suitable amount of iron alginates can further reduce the fire hazard, and improve the mechanical properties of EP/APP composites.
Bio‐based iron alginate is chosen as an eco‐friendly synergist and mixed with ammonium polyphosphate (APP) into epoxy resin (EP) aiming to enhance the flame retardancy and smoke suppression of EP/APP composites.
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•An approach for latent flame-retardant curing agents for EP was proposed.•The one-pack EP exhibited long pot life when storing and fast curing as operating.•The cured EP showed ...excellent flame retardance.
Liquid epoxy resins (EP), curing agents, as well as other additives such as flame retardants are preferred to be formulated as one-pack materials rather than being mixed just prior to their applications. Therefore, they suffer premature curing with increasing of viscosity during storing and operating. To address the above challenging problem, we designed and synthesized a novel latent flame-retardant curing agent named 1-(diphenylphosphinyl)-1H-imidazole oxide (DPPIO) for EP, which was proved exhibiting not only long pot life during storing and fast curing as operating, but also excellent flame retardance after curing. It was observed from dynamic rheometry that, DPPIO/EP kept stable near room temperature for a long time but quickly gelated within only 6.5 min at 150 °C. With only 15 wt% addition of DPPIO, the limiting oxygen index (LOI) of the cured sample increased to 38.0% from 21.0% of the contrast sample, and UL-94 V-0 rating at 1.6 mm thickness was successfully achieved. Peak of heat release rate (PHRR) and total heat release (THR) obtained from cone calorimetry further certified excellent flame retardance of DPPIO/EP. Another typical flame-retardant group with different chemical environment was designed for modifying imidazole to obtain a derivative named diphenyl 1H-imidazol-1-ylphosphonate (DPIPP) in the same way. It was verified that DPIPP/EP showed acceptable latent curing efficiency and satisfactory flame retardance as DPPIO/EP did. Therefore, it’s a generally effective and facile approach to develop latent flame-retardant curing agents for EP by modifying imidazole with appropriate flame-retardant groups. Taking advantage of the features, these one-pack flame-retardant epoxy materials can bring more chances for widespread applications.
In this paper, we study the optimal location planning of renewable distributed generation (RDG) units by taking into account the random uncertainties of renewable generation and load demand. In ...presence of the random uncertainties, location planning problem is naturally a two-stage stochastic mixed integer nonlinear programming problem, which is hard to solve efficiently. Instead of using traditional sampling methods or robust optimization methods, we propose a novel analytical approach in this paper to solve the problem efficiently and optimally. In particular, analytical expressions are derived for efficiently evaluating the performance of a candidate RDG placement decision. In this way, the stochastic mixed integer nonlinear programming problem is equivalently transformed into a deterministic integer problem, which can be solved efficiently using off-the-shelf tools. Numerical results show that the optimal RDG placement can save up to 4.2% of the long-term average cost and 80.59% of the line losses on the IEEE 13-bus test feeder. In addition, our proposed approach effectively reduces the computational time by 99.51% on the IEEE 123 node test feeder compared with other traditional sampling-based metaheuristic approaches.
A nano-coating containing phosphorus, nitrogen and silicon was constructed on T/C blends by LbL assembly from colloidal silica and polyphosphate to reduce flammability of the fabrics by the ...dominating condensed-phase activity.
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•A P/N/Si-containing nano-coating was constructed by LbL assembly.•The treated T/C blends achieved self-extinguishing in VFT.•The coated T/C blends were free from scaffolding effect towards fire safety.
Polyester/cotton (T/C) blends are widely used in the textile industry owed to the combination of both advantages of cotton and polyester. However, T/C blends are highly flammable due to the well-known scaffolding effect of the melting polyester and non-melting cotton fibers. Herein, to reduce the flammability of T/C blends, a nano-coating containing phosphorus, nitrogen and silicon was designed and constructed by layer-by-layer assembly of colloidal silica and polyphosphates. It was confirmed that the homogeneous nano-coating was successfully deposited on the surface of T/C blends, regardless of different surface morphologies and chemical nature of the synthetic and inartificial fibers. Encouragingly, with 15 bilayer nano-coatings (15.5% weight increased), the coated T/C blends achieved self-extinguishing and got away from scaffolding effect in vertical flame test, and showed a little delay of ignition and a strong decrease of heat release during cone calorimetry test, indicating excellent flame retardance of the treated fabrics. The nano-coating had both gaseous- and condensed-phase flame-retardant activity, which was further confirmed by the results of char analysis and thermogravimetric analysis/infrared spectrometry.
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