Reduced Pollutant Emissions and Slagging Rate of Biomass Pellet Combustion by Optimizing the Multilayer Distribution of Secondary Air.

The utilization of coal and other fossil fuels is becoming increasingly restricted. Biomass, as a clean and renewable energy, plays a significant role in achieving zero carbon emissions. However, biomass is prone to slagging in the combustion process due to its high alkali metal content. The ash slagging rate and pollutant emission level of flue gas can be reduced by optimizing the air distribution, in order to decrease the fuel layer temperature in the combustion chamber. The results reveal opposite change trends of CO and NOx concentrations in the flue gas. The NOx emissions of corn stalk combustion under the multilayer secondary air distribution are obvious compared with those of rice husk combustion. The slagging rate of corn stalks is highly correlated with temperature T 1 of the fuel bed. The silica ratio (G), alkali/acid ratio (B/A), Na content index (Na (index)), and alkaline index (Al c ) cannot accurately predict the slagging tendency when temperature T 1 changes. Therefore, the modified predictive index (Gt ) was proposed to predict the slagging tendency of corn stalks with the combustion zone temperature T 1 effectively. The experimental results can contribute to the efficient combustion and low pollutant emissions of biomass.

The association of chronic endometritis with mid-trimester loss due to cervical incompetence and the outcome of laparoscopic cervical cerclage.

PURPOSE: To examine the association of chronic endometritis (CE) with cervical incompetence (CI) in Chinese women with mid-trimester loss, and the impact of the presence of CE on the outcome of laparoscopic cervical cerclage (LCC). METHODS: This retrospective cohort study included a study group of 293 women with mid-trimester loss due to CI (group I) and a comparison group of 332 women with recurrent first-trimester miscarriage (group II). Immunohistochemical study using CD138 epitope for the diagnosis of CE was completed in all subjects. Pre-conception LCC was undertaken in 247 women in the study group (group I). The study was approved by Institutional Review Board (IRB) (number 2015FXHEC-KY005). RESULTS: The prevalence of CE in group I was 42%, significantly (P < 0.001) higher than that of 23.5% in group II. Among 247 women in group I, there were no significant difference in mid-trimester loss rate, preterm delivery rate and term delivery rate in women with and without CE (2.2, 12.0, 85.8% vs. 1.8, 10.1, 88.1% respectively) and between women with CE treated and not treated with antibiotics prior to conception (2.3, 9.3, 88.4% vs. 2.0, 14.3, 83.7% respectively). CONCLUSIONS: Mid-trimester loss due to cervical incompetence is associated with chronic endometritis; However, the presence or not of CE and whether it was treated with antibiotics prior to conception did not appear to significantly influence the obstetric outcomes of women with CI after LCC.

Ternary catalyst Mn-Fe-Ce/Al2O3 for the ozonation of phenol pollutant: performance and mechanism.

In this study, a novel ternary catalyst Mn-Fe-Ce/Al2O3 was synthesized by co-impregnation method, and was characterized by XRD, SEM, XPS, and FTIR. The catalytic performance of this ternary catalyst was evaluated in the heterogeneous catalytic ozonation of phenol pollutants and it improved the removal rate and mineralization degree of phenol pollutants. The changes of dissolved ozone in water and the TBA experiment proved that the ternary catalyst could accelerate the decomposition of ozone into hydroxyl radicals, thus accelerating the oxidation of phenol. Phosphate experiments and surface hydroxyl density measurements proved that surface hydroxyl was the active site of the catalyst. XPS analysis showed that the ternary catalysts accelerated electron transfer through the redox cycles of Mn2+-Mn3+-Mn4+, Fe2+-Fe3+, and Ce3+-Ce4+, which also contributed to the high catalytic activity. Moreover, the catalyst maintained high catalytic activity after five cycles of use. Therefore, the ternary catalyst was considered an efficient and promising catalyst for catalytic ozonation system.

Study of the adsorption mechanism on the surface of a ceramic nanomaterial for gaseous Hg(II) removal.

Stable Hg(II)-containing flue gas has been successfully simulated by the plasma oxidation of Hg(0), and an effective solution for Hg(0) mercury fumes was obtained by combining the plasma with a ceramic nanomaterial. Characterization tests showed that the ceramic nanomaterial was mainly composed of silicon dioxide (SiO2) with other minor constituents, including potassium mica (KAl3Si3O11), iron magnesium silicate (Fe0.24Mg0.76SiO3) and dolomite (CaMg(CO3)2). The nanomaterial had many tube bank structures inside with diameters of approximately 8-10 nm. The maximum sorption capacity of Hg(II) was 5156 µg/g, and the nanomaterial can be regenerated at least five times. During the adsorption, chemical adsorption first occurred between Hg(II) and sulfydryl moieties, but these were quickly exhausted, and Hg(II) was then removed by surface complexation and wrapped into Fe moieties. The pseudo-first-order kinetic model and the Langmuir equation had the best fitting results for the kinetics and isotherms of adsorption. This work suggests that the ceramic nanomaterial can be used as an effective and recyclable adsorbent in the removal of gaseous Hg(II).

Correlation between hysteroscopy findings and chronic endometritis.

OBJECTIVE: To evaluate the role of hysteroscopy in the diagnosis of chronic endometritis (CE). DESIGN: Retrospective cohort study. SETTING: University teaching hospital. PATIENT(S): A consecutive series of 1,189 cases of diagnostic hysteroscopy. INTERVENTION(S): Endometrial biopsy specimens were obtained after hysteroscopy for routine histology and immunohistochemistry for plasma cells using a CD138 epitope. MAIN OUTCOME MEASURE(S): Observer variability, sensitivity, specificity, and accuracy of the hysteroscopic features in the diagnosis of CE. RESULT(S): Immunohistochemistry of biopsy specimens showed presence of CD138 cells in 322 of 1,189 cases (27.1%). Among cases that tested positive for CD138 cells, the prevalence of hysteroscopic features was as follows: endometrial hyperemia, 169 of 322 (52.5%); endometrial interstitial edema, 27 of 322 (8.4%); and micro-polyps, 11 of 322 (3.4%). The κ value of intraobserver and interobserver agreement on the presence or absence of the hysteroscopic feature of CE was 0.86 and 0.73, respectively. The sensitivity, specificity, positive and negative predictive value, and diagnostic accuracy of the presence of one or more hysteroscopy features were 59.3%, 69.7%, 42.1%, 82.8%, and 66.9%, respectively. CONCLUSION(S): The finding of endometrial hyperemia, micro-polyps or endometrial interstitial edema during hysteroscopy should alert to the diagnosis of CE, but the overall accuracy of hysteroscopic examination with regard to the diagnosis of CE is only 67%, so it should not be used to replace histologic examination as the diagnostic tool of choice. In women in whom a diagnosis of CE is considered likely, endometrial biopsy should be obtained to examine plasma cells by immunohistochemistry, which should remain the preferred method for diagnosis.

Prevalence and confounders of chronic endometritis in premenopausal women with abnormal bleeding or reproductive failure.

In this retrospective cohort study, a consecutive series of 1551 premenopausal women underwent hysteroscopy and endometrial biopsy. Chronic endometritis was diagnosed when plasma cell in endometrial tissue was detected by immunohistochemistry using CD138 epitope. The overall prevalence of chronic endometritis in the population studied was 24.4% The prevalence was significantly increased in the following conditions: recurrent implantation failure (40.8%; P < 0.001), abnormal uterine bleeding (40.7 %; P < 0.001), endometrial hyperplasia (50.0%, P < 0.05) and submucosal fibroid (59.1%; P < 0.001) than those without the respective conditions. The prevalence in specimens obtained from the proliferative phase (26.0%) was significantly higher (P < 0.05) than those from the luteal phase (17.5%). Logistic regression analysis showed three significant factors affecting the prevalence, in descending order of importance: clinical presentation, endometrial hyperplasia and stage of the cycle from which the specimen was obtained. The confounding variables identified in this study may account for the wide range of published prevalence of the condition, and should be considered in the analysis of prevalence data relating to chronic endometritis.

Kaposiform hemangioendothelioma in the uterine cervix of a 5-year girl.

The occurrence of the vascular tumors in the female genital tract, particularly in the uterine cervix, is extremely rare. This kind of tumor has mainly been reported as either cavernous hemangiomas or capillary hemangiomas. To date, no Kaposiform hemangioendothelioma has been reported in this site. Here we presented a case of Kaposiform hemangioendothelioma without Kasabach-Merritt syndrome in the cervix of a 5-year-old girl.

[Research on the quality changes in pre-and-post-processed pieces of Radix Polygalae].

OBJECTIVE: To study the quality changes in pre-and-post-processed pieces of Radix Polygalae. METHODS: The changes of the content of senegenin and polygalacic acid were studied. RESULTS: The content of polygalacic acid in post-processed piece was lower than that in pre-processed piece. The content of senegenin had no obvious difference. CONCLUSION: The processing can make the quality change.

"Simulating synthesis": ceria nanosphere self-assembly into nanorods and framework architectures.

We predict, from computer modeling and simulation in partnership with experiment, a general strategy for synthesizing spherical oxide nanocrystals via crystallization from melt. In particular we "simulate synthesis" to generate full atomistic models of undoped and Ti-doped CeO2 nanoparticles, nanorods, and nanoporous framework architectures. Our simulations demonstrate, in quantitative agreement with experiment [Science 2006, 312, 1504], that Ti (dopant) ions change the shape of CeO2 nanocrystals from polyhedral to spherical. We rationalize this morphological change by elucidating, at the atomistic level, the mechanism underpinning its synthesis. In particular, CeO2 nanocrystals can be synthesized via crystallization from melt: as a molten (undoped) CeO2 nanoparticle is cooled, nucleating seeds spontaneously evolve at the surface and express energetically stable [111] facets to minimize the energy. As crystallization proceeds, the [111] facets grow, thus facilitating a polyhedral shape. Conversely, when doped with Ti, a (predominantly) TiO2 shell encapsulates the inner CeO2 core. This shell inhibits the evolution of nucleating seeds at the surface thus rendering it amorphous during cooling. Accordingly, crystallization is forced to proceed via the evolution of a nucleating seed in the bulk CeO2 region of the nanoparticle, and as this seed grows, it remains surrounded by amorphous ions, which "wrap" around the core so that the energies for high-index facets are drastically reduced; these amorphous ions adopt a spherical shape to minimize the surface energy. Crystallization emanates radially from the nucleating seed, and because it is encapsulated by an amorphous shell, the crystallization front is not compelled to express energetically favorable surfaces. Accordingly, after the nanoparticle has crystallized it retains this spherical shape. A typical animation showing the crystallization (with atomistic detail) is available as Supporting Information. From this data we predict that spherical oxide nanocrystals can be synthesized via crystallization from melt in general by suppressing nucleating seed evolution at the surface thus forcing the nucleating seed to spontaneously evolve in the bulk. Nanospheres can, similar to zeolitic classifications, constitute Secondary Building Units (SBUs) and can aggregate to form nanorods and nanoporous framework architectures. Here we have attempted to simulate this process to generate models for CeO2 and Ti-doped CeO2 nanorods and framework architectures. In particular, we predict that Ti doping will "smooth" the surfaces: hexagonal prism shaped CeO2 nanorods with [111] and [100] surfaces become cylindrical, and framework architectures change from facetted pores and channels with well-defined [111] and [100] surfaces to "smooth" pores and channels (expressing both concave and convex curvatures). Such structures are difficult to characterize using, for example, Miller indices; rather we suggest that these new structural materials may be better described using minimal surfaces.

Converting ceria polyhedral nanoparticles into single-crystal nanospheres.

Ceria nanoparticles are one of the key abrasive materials for chemical-mechanical planarization of advanced integrated circuits. However, ceria nanoparticles synthesized by existing techniques are irregularly faceted, and they scratch the silicon wafers and increase defect concentrations. We developed an approach for large-scale synthesis of single-crystal ceria nanospheres that can reduce the polishing defects by 80% and increase the silica removal rate by 50%, facilitating precise and reliable mass-manufacturing of chips for nanoelectronics. We doped the ceria system with titanium, using flame temperatures that facilitate crystallization of the ceria yet retain the titania in a molten state. In conjunction with molecular dynamics simulation, we show that under these conditions, the inner ceria core evolves in a single-crystal spherical shape without faceting, because throughout the crystallization it is completely encapsulated by a molten 1- to 2-nanometer shell of titania that, in liquid state, minimizes the surface energy. The principle demonstrated here could be applied to other oxide systems.