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排序方式: 共有3718条查询结果,搜索用时 15 毫秒
1.
Radamez D. Darolt Maykon Cargnin Michael Peterson Agenor De Noni Jr 《International Journal of Applied Ceramic Technology》2020,17(4):1742-1751
Porcelain stoneware tile is the best class of ceramic tiles regarding technical performance. Low porosity and high glass content are some of its highlighted characteristics. The manufacturing cost is highly dependent on the feldspar content and the processing flow rate. Certain technical bottlenecks in the manufacturing steps, such as milling, forming, and firing, are intrinsically associated with limitations in the processing properties, such as the dry strength, bulk density, and pyroplastic deformation. In this work, improvements in these properties were achieved using high-energy milling (HEM) after conventional milling (CM). This study was carried out on a pilot industrial scale in the milling stage. Six experimental runs were evaluated. Slurries were spray-dried. The powders were humidified with 6.5% moisture. Specimens were conformed under a specific pressure of 45 MPa. The firing was performed using temperature ranging from 1150 to 1230°C. The use of HEM, in comparison to traditional milling for the similar particle-size distributions, has increased the dry density, +0.2 g.cm−3, dry bending strength, +1.0 MPa, and decreased the pyroplastic deformation index, −1.10−5 cm−1. These results allow an estimated thickness reduction of 10%. 相似文献
2.
J. D. Benson L. O. Bubulac A. Wang R. N. Jacobs J. M. Arias M. Jaime-Vasquez P. J. Smith L. A. Almeida A. Stoltz P. S. Wijewarnasuriya A. Yulius M. Carmody M. Reddy J. Peterson S. M. Johnson J. Bangs D. D. Lofgreen 《Journal of Electronic Materials》2018,47(10):5671-5679
In this work, impurity ‘hot spot’ macro-defects—high impurity level macro-defect contaminates were examined. ‘Hot spots’ have very high localized concentrations of: K, Mg, Ni, Cr, Mn, Ca, Al, Na, Fe, and Cu. For example, these ‘hot spot’ macro-defects can have Cu concentrations >?1?×?1018 cm?3. Focused ion beam scanning transmission electron microscopy analysis of four ‘hot spots’ was performed. The origin of ‘hot spot’ defects is unresolved—however, our analysis has shown ‘hot spots’ can arise due to molecular beam epitaxy spit defects and CdZnTe substrate defects. The estimated ‘hot spot’ density is ~?30 cm?2. The presence of impurity ‘hot spot’ macro-defects in HgCdTe/CdZnTe is confirming evidence for the occurrence of L. Bubulac’s impurity ‘pipe’ mechanism. 相似文献
3.
Dr. Pui-Ying Lam Dr. Peter Kutchukian Rajan Anand Dr. Jason Imbriglio Dr. Christine Andrews Hugo Padilla Anita Vohra Sarah Lane Dann L. Parker Jr. Dr. Ivan Cornella Taracido Dr. Douglas G. Johns Dr. Manu Beerens Dr. Calum A. MacRae John P. Caldwell Dr. Steve Sorota Dr. Aarti Asnani Dr. Randall T. Peterson 《Chembiochem : a European journal of chemical biology》2020,21(13):1905-1910
Doxorubicin is a highly effective chemotherapy agent used to treat many common malignancies. However, its use is limited by cardiotoxicity, and cumulative doses exponentially increase the risk of heart failure. To identify novel heart failure treatment targets, a zebrafish model of doxorubicin-induced cardiomyopathy was previously established for small-molecule screening. Using this model, several small molecules that prevent doxorubicin-induced cardiotoxicity both in zebrafish and in mouse models have previously been identified. In this study, exploration of doxorubicin cardiotoxicity is expanded by screening 2271 small molecules from a proprietary, target-annotated tool compound collection. It is found that 120 small molecules can prevent doxorubicin-induced cardiotoxicity, including 7 highly effective compounds. Of these, all seven exhibited inhibitory activity towards cytochrome P450 family 1 (CYP1). These results are consistent with previous findings, in which visnagin, a CYP1 inhibitor, also prevents doxorubicin-induced cardiotoxicity. Importantly, genetic mutation of cyp1a protected zebrafish against doxorubicin-induced cardiotoxicity phenotypes. Together, these results provide strong evidence that CYP1 is an important contributor to doxorubicin-induced cardiotoxicity and highlight the CYP1 pathway as a candidate therapeutic target for clinical cardioprotection. 相似文献
4.
ABSTRACT A series of batch contact tests were conducted to evaluate the exchange behavior of Ba, Ca, Pb, and Sr onto crystalline silicotitanate (CST) in support of an expedited Cs removal and pretreatment system at the Hanford site. Binary Na/M2+ and ternary Na/Cs/M2+ isotherms were generated to understand selectivity, capacity, and competitive impact of each analyte on Cs uptake from a simple 1 M NaOH/4.6 M NaNO3 simulant. Analyte loading from a 0.1 M NaOH/5.5 M NaNO3 simulant was assessed to determine the effect of hydroxide concentration on binary Na/M2+ isotherms. Results from binary and ternary isotherms indicated that Group II metals Ca, Sr, and Ba (and Pb) do not impact CST performance toward Cs removal at concentrations expected in Hanford tank-waste supernate. 相似文献
5.
Linear Aliphatic Dialkynes as Alternative Linkers for Double‐Click Stapling of p53‐Derived Peptides 下载免费PDF全文
Yu Heng Lau Dr. Peterson de Andrade Dr. Grahame J. McKenzie Prof. Ashok R. Venkitaraman Prof. David R. Spring 《Chembiochem : a European journal of chemical biology》2014,15(18):2680-2683
We investigated linear aliphatic dialkynes as a new structural class of i,i+7 linkers for the double‐click stapling of p53‐based peptides. The optimal combination of azido amino acids and dialkynyl linker length for MDM2 binding was determined. In a direct comparison between aliphatic and aromatic staple scaffolds, the aliphatic staples resulted in superior binding to MDM2 in vitro and superior p53‐activating capability in cells when using a diazidopeptide derived from phage display. This work demonstrates that the nature of the staple scaffold is an important factor that can affect peptide bioactivity in cells. 相似文献
6.
Chlorination of drinking water in the presence of bromide and dissolved organic carbon (DOC) leads to the formation of brominated and chlorinated disinfection by-products (DBP). The concentration of bromide ions in the raw water is a significant factor in the speciation of DBP formed, and causes shifts in trihalomethane (THM) formation from chlorinated to brominated species. Drinking water treatment techniques that remove organic contaminants without affecting bromide ion concentrations cause increases in the brominated THM. For the present study, three water supplies containing different DOC and ambient bromide concentrations were filtered through biologically assisted granular activated carbon (BGAC). Similar to adsorption and coagulation treatment, this treatment does not remove bromide from drinking water; also, THMFP (trihalomethane formation potential) analysis indicated that the chlorinated effluent contained higher concentrations of brominated THM in comparison to the influent. Although BGAC may increase the brominated THM, which may be more toxic than the chlorinated THM, the overall reduction of THMFP by DOC removal far exceeds this negative change, thereby producing a much less toxic finished drinking water. This work is part of a study to make high DOC surface waters on the Canadian prairie safe and palatable for small volume users (individuals or small communities). 相似文献
7.
Teaching construction project management with BIM support: Experience and lessons learned 总被引:1,自引:0,他引:1
Forest Peterson Timo HartmannRenate Fruchter Martin Fischer 《Automation in Construction》2011,20(2):115-125
This paper presents experiences and lessons learned during the introduction of Building Information Models (BIM) in construction engineering project management courses. We illustratively show that the introduction of BIM-based project management tools helped the teachers of two courses to develop more realistic project-based class assignments that supported students with learning how to apply different formal project management methods to real-world project management problems. In particular, we show that the introduction of BIM allows educators to design a class project that allowed the use of more realistic cases that better simulate real-world project conditions, helped students to learn how different project management methods integrate with each other, integrate change management tasks in a class assignment, and learn how to optimize project plans. 相似文献
8.
Gregory W. Peterson Omar K. Farha Bryan Schindler Paulette Jones John Mahle Joseph T. Hupp 《Journal of Porous Materials》2012,19(2):261-266
A previously described porous organic polymer (NU-POP-1) was evaluated against four representative chemical threats: ammonia,
cyanogen chloride, sulfur dioxide, and octane. Ammonia, cyanogen chloride, and sulfur dioxide are examples of toxic industrial
chemicals (TICs) spanning the range from highly basic to strong-acid forming substances, while octane is used to assess physical
adsorption capacity. Experiments were carried out using a microbreakthrough test apparatus, which measures the adsorption
capacity at saturation and gives an indication of the strength of adsorption. The NU-POP-1 material exhibited substantial
removal capabilities against the majority of the toxic chemicals, with capacities as high as or better than an activated,
impregnated carbon. The ability to remove the highly volatile toxic chemicals ammonia and cyanogen chloride was intriguing,
as these chemicals typically require reactive moieities for removal. The present work presents a benchmark for toxic chemical
removal, and future work will focus on incorporating functional groups targeting the toxic chemicals of interest. 相似文献
9.
Andrew A. Peterson 《Topics in Catalysis》2014,57(1-4):40-53
As the complexity of atomistic simulations in catalysis and surface science increases, the challenge of manually finding the lowest-energy adsorbate–surface geometries grows significantly. In the current work, a global optimization approach that preserves adsorbate identity is applied to enable the automated search for optimized binding geometries. This technique is based on the minima hopping method developed by Goedecker, but is modified to preserve the molecular identity of adsorbates by the application of a new class of Hookean constraints. These constraints are completely inactive when the adsorbate identity is preserved, but act to restore the adsorbate structure via a Hookean force when the bond length exceeds a threshold distance. Additionally, a related Hookean constraint has been developed to prevent adsorbates (particularly such adsorbates as CO and CH2O that have stable gas-phase forms) from volatilizing during the molecular dynamics portion of the minima hopping technique. This combination, referred to herein as the constrained minima hopping method, was tested for its suitability in finding the minimum-energy binding configuration for a set of 17 C x H y O z adsorbates on a stepped Cu fcc(211) surface and in all cases found the global minima in comparable or fewer steps than the previous brute force methodologies. It is expected that methods such as this will be crucial to finding low-energy states in more complex systems, such as those with high coverages of adsorbed species or in the presence of explicit solvent molecules. 相似文献
10.
Jana A. Hirsch Geoffrey F. Green Marc Peterson Daniel A. Rodriguez Penny Gordon-Larsen 《Journal of Urbanism》2017,10(2):181-197
While increasing evidence suggests an association between physical infrastructure in neighborhoods and health outcomes, relatively little research examines how neighborhoods change physically over time and how these physical improvements are spatially distributed across populations. This paper describes the change over 25 years (1985–2010) in bicycle lanes, off-road trails, bus transit service and parks, and spatial clusters of changes in these domains relative to neighborhood sociodemographics in four US cities that are diverse in terms of geography, size, and population. Across all four cities we identified increases in bicycle lanes, off-road trails, and bus transit service, with spatial clustering in these changes that related to neighborhood sociodemographics. Overall, we found evidence of positive changes in physical infrastructure commonly identified as supportive of physical activity. However, the patterning of infrastructure change by sociodemographic change encourages attention to the equity in infrastructure improvements across neighborhoods. 相似文献