One of the most well-known, highly utilized reagents for ether cleavage is boron tribromide (BBr3), and this reagent is frequently employed in a 1:1 stoichiometric ratio with ethers. Density functional theory calculations predict a new mechanistic pathway involving charged intermediates for ether cleavage in aryl methyl ethers. Moreover, these calculations predict that one equivalent of BBr3 can cleave up to three equivalents of anisole, producing triphenoxyborane [B(OPh)3] prior to hydrolysis. These predictions were validated by gas chromatography analysis of reactions where the BBr3:anisole ratio was varied. Not only do we confirm that sub-stoichiometric equivalents may be used for ether demethylation, but the findings also support our newly proposed three cycle mechanism for cleavage of aryl methyl ethers.
Zinc-nickel alloys with 8-15% nickel were deposited onto stainless steel for corrosion protection. Alkaline deposition conditions were utilized given that alkaline systems have been found to offer superior substrate coverage which results in better corrosion protection of the metal substrate (stainless steel) compared to acid bath depositions. This method utilizes ammonium hydroxide as the base source with a working pH range of 9-9.5. Sodium acetate was used as the complexing ligand as it was found to stabilize the metal ions in the electrolytic solution. Strongly adhering, quality deposits were obtained with electrodeposition at room temperature. Bath compositions and applied potential had an effect on morphology of the films as seen in scanning electron microscopy. Upon examination by x-ray diffraction and atomic absorption spectroscopy, all deposits were confirmed as γ phase zinc-nickel alloys with a nickel content of 8-15%. The corrosion potential for the γ-phase coatings was improved over the pure zinc coatings.
Zinc-nickel alloys with 8-15% nickel were deposited onto stainless steel for corrosion protection. Alkaline deposition conditions were utilized given that alkaline systems have been found to offer superior substrate coverage which results in better corrosion protection of the metal substrate (stainless steel) compared to acid bath depositions. This method utilizes ammonium hydroxide as the base source with a working pH range of 9-9.5. Sodium acetate was used as the complexing ligand as it was found to stabilize the metal ions in the electrolytic solution. Strongly adhering, quality deposits were obtained with electrodeposition at room temperature. Bath compositions and applied potential had an effect on morphology of the films as seen in scanning electron microscopy. Upon examination by x-ray diffraction and atomic absorption spectroscopy, all deposits were confirmed as γ phase zinc-nickel alloys with a nickel content of 8-15%. The corrosion potential for the γ-phase coatings was improved over the pure zinc coatings.
Background:
Numerous studies in the medical and surgical literature have discussed the income gap between male and female physicians, but none has adequately accounted for the disparity.
Methods:
This study was performed to determine whether gender-related billing and coding differences may be related to the income gap. A 10 percent minimum difference was set a priori as statistically significant. A cohort of 1036 candidates’ 9-month case lists for the American Board of Plastic Surgery over a 5-year span (2014 to 2018) was evaluated for relationships between surgeon gender and work relative value units, coding information, major and minor cases performed, and work setting. Data were deidentified by the American Board of Plastic Surgery before evaluation. The authors hypothesized that work relative value units, average codes per case, major cases, and minor cases would be at least 10 percent higher for male than for female physicians.
Results:
Significant differences were found between male and female surgeons in work relative value units billed, work relative value units billed per case, and the numbers of major cases performed. The average total work relative value units for male surgeons was 19.34 percent higher than for female surgeons [3253.2 (95 percent CI, 3090.5 to 3425.8) versus 2624.1 (95 percent CI, 2435.2 to 2829.6)]. Male surgeons performed 14.28 percent more major cases than female surgeons [77.6 percent (95 percent CI, 72.7 to 82.7 percent) versus 90.5 percent (95 percent CI, 86.3 to 94.9 percent); p = 0.0002].
Conclusions:
The authors’ findings support the hypothesis that billing and coding practices can, in part, account for income differences between male and female plastic surgeons. Potential explanations include practices focusing on larger and more complex operative cases and differences in coding practices.
Composite coatings can demonstrate improved property performance as compared to metals and alloy materials. One category of composite coatings is composed of metal or metal alloys with a dispersed phase of nonmetallic nanoparticles. The addition of these nanoparticles has been found to improve corrosion, wear resistance, and hardness. Producing metal composite coatings using electrochemical techniques can be advantageous due to reduced production cost, lower working temperatures, and precise control of experimental parameters. Metal coatings such as zinc have been successfully co-deposited with TiO 2 , SiO 2 , CeO 2 and mica particles and nickel has been co-deposited with a number of materials including TiO 2 , SiC, Al 2 O 3 , PTFE and silicates. Zinc-nickel alloys have long been studied for a number of properties, most notably corrosion resistance and recently their tribological properties. This chapter reviews the literature on electrodeposition of ZnNi nanocomposite coatings. Although there has been much work done on composite coatings, there is much less literature available on composite coatings with zinc-nickel alloys. So in this review, we look at the general trends for nanoparticle incorporation, deposition mechanisms, system stability, microstructures of the coatings and general corrosion trends.
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