High-Pressure XPS of Crotyl Alcohol Selective Oxidation over Metallic and Oxidized Pd(111)

Here, we report on the first application of high-pressure XPS (HP-XPS) to the surface catalyzed selective oxidation of a hydrocarbon over palladium, wherein the reactivity of metal and oxide surfaces in directing the oxidative dehydrogenation of crotyl alcohol (CrOH) to crotonaldehyde (CrHCO) is evaluated. Crotonaldehyde formation is disfavored over Pd(111) under all reaction conditions, with only crotyl alcohol decomposition observed. In contrast, 2D Pd₅O₄ and 3D PdO overlayers are able to selectively oxidize crotyl alcohol (1 mTorr) to crotonaldehyde in the presence of co-fed oxygen (140 mTorr) at temperatures as low as 40 °C. However, 2D Pd₅O₄ ultrathin films are unstable toward reduction by the alcohol at ambient temperature, whereas the 3D PdO oxide is able to sustain catalytic crotonaldehyde production even up to 150 °C. Co-fed oxygen is essential to stabilize palladium surface oxides toward in situ reduction by crotyl alcohol, with stability increasing with oxide film dimensionality

Adolescent Use of Different E-cigarette Products

BACKGROUND: Little is known about the characteristics of electronic cigarettes (e-cigarettes) used by adolescents. Understanding the product landscape of adolescent e-cigarette use may inform counseling and policy strategies. METHODS: Results are from 13 651 adolescents in wave 1 and 12 172 adolescents in wave 2 of the Population Assessment of Tobacco and Health Study, a nationally representative longitudinal study. Past 30-day regular e-cigarettes users were asked about the characteristics of the e-cigarette they used most of the time. RESULTS: In waves 1 and 2, 2.1% and 2.8% of adolescents were regular users in the past 30 days, respectively. These adolescents more often used rechargeable rather than disposable devices (wave 1: 76.0%; wave 2: 82.9%) and refillable rather than nonrefillable devices (wave 1: 66.6%; wave 2: 84.4%) and tended not to use cartridge systems (wave 1: 33.7%; wave 2: 30.5%). Most adolescent past 30-day users (wave 1: 87.5%; wave 2: 89.4%) reported using flavored e-cigarettes. An increased frequency of use was associated with the use of rechargeable (wave 1 adjusted odds ratio [aOR]: 2.7; wave 2 aOR: 2.7) and refillable e-cigarettes (wave 1 aOR: 2.0; wave 2 aOR: 2.7; P < .05). Most users in wave 1 did not continue regular use in wave 2 (70.2%). Among those who continued to use and had reported using closed systems (nonrechargeable and/or nonrefillable) in wave 1, most had progressed to open systems (rechargeable and refillable) in wave 2. CONCLUSIONS: Most adolescents use open-system e-cigarettes, and frequent users are even more likely to use open-system e-cigarettes. The majority of regular users use rechargeable devices that are refillable. A change in product preferences across waves suggests a starter product phenomenon, with a graduation to products that have weaker quality controls and may increase health risks

Tunable KIT-6 Mesoporous Sulfonic Acid Catalysts for Fatty Acid Esterification

We report the first catalytic application of pore-expanded KIT-6 propylsulfonic acid (PrSO₃H) silicas, in fatty acid esterification with methanol under mild conditions. As-synthesized PrSO₃H-KIT-6 exhibits a 40 and 70% enhancement in turnover frequency (TOF) toward propanoic and hexanoic acid esterification, respectively, over a PrSO₃H-SBA-15 analogue of similar 5 nm pore diameter, reflecting the improved mesopore interconnectivity of KIT-6 over SBA-15. However, pore accessibility becomes rate-limiting in the esterification of longer chain lauric and palmitic acids over both solid acid catalysts. This problem can be overcome via hydrothermal aging protocols which permit expansion of the KIT-6 mesopore to 7 nm, thereby doubling the TOF for lauric and palmitic acid esterification over that achievable with PrSO₃H-SBA-15

Redox-Controlled Crotyl Alcohol Selective Oxidation: In Situ Oxidation and Reduction Dynamics of Catalytic Pd Nanoparticles via Synchronous XANES/MS

In-situ, synchronous MS/XANES reveals the Pd catalyzed selective aerobic oxidation of crotyl alcohol is regulated by the balance between the oxidation state and reducibility. Dynamic XANES measurements provide a new, rapid method to determine redox kinetics of nanoparticles and identify important parameters to optimize catalyst design

Public Support for Smoke-Free Section 8 Public Housing

As of July 31, 2018, all Housing and Urban Development (HUD) designated Housing Authorities administering public housing must have a smoke-free policies, but this requirement does not extend to Section 8 housing. Section 8 public housing vouchers provide subsidies for private rental housing for low-income residents. This study examines support for smoke-free policy options in Section 8 housing. Using a nationally representative survey of adults, we asked 3,070 respondents to agree or disagree with two potential policies. The majority (71%) supported prohibiting indoor smoking everywhere inside buildings that have Section 8 housing units. Alternatively, respondents were less supportive (38%) of a policy to prohibit smoking only inside of units with Section 8 subsidies, and allowing smoking in non-subsidized units. Prohibiting smoking in all units in MUH buildings would help protect the health of both the 2.2 million households who receive Section 8 subsidies, and their neighbors

Hierarchically Ordered Nanoporous Pd/SBA-15 Catalyst for the Aerobic Selective Oxidation of Sterically Challenging Allylic Alcohols

The utility of a hierarchically ordered nanoporous SBA-15 architecture, comprising 270 nm macropores and 5 nm mesopores (MM-SBA-15), for the catalytic aerobic selective oxidation of sterically challenging allylic alcohols is shown. Detailed bulk and surface characterization reveals that incorporation of complementary macropores into mesoporous SBA-15 enhances the dispersion of sub 2 nm Pd nanoparticles and thus their degree of surface oxidation. Kinetic profiling reveals a relationship between nanoparticle dispersion and oxidation rate, identifying surface PdO as the catalytically active phase. Hierarchical nanoporous Pd/MM-SBA-15 outperforms mesoporous analogues in allylic alcohol selective oxidation by (i) stabilizing PdO nanoparticles and (ii) dramatically improving in-pore diffusion and access to active sites by sesquiterpenoid substrates such as farnesol and phytol

Bifunctional Organorhodium Solid Acid Catalysts for Methanol Carbonylation

Robust, bifunctional catalysts comprising Rh­(CO)­(Xantphos) exchanged phosphotungstic acids of general formulas [Rh­(CO)­(Xantphos)]⁺_<i>n</i>[H_3–<i>n</i>PW₁₂O₄₀]^<i>n</i>− have been synthesized over silica supports which exhibit tunable activity and selectivity toward direct vapor phase methanol carbonylation. The optimal Rh:acid ratio = 0.5, with higher rhodium concentrations increasing the selectivity to methyl acetate over dimethyl ether at the expense of lower acidity and poor activity. On-stream deactivation above 200 °C reflects Rh decomplexation and reduction to Rh metal, in conjunction with catalyst dehydration and loss of solid acidity because of undesired methyl acetate hydrolysis, but can be alleviated by water addition and lower temperature operation

Numbers of spectacled flying-foxes (<i>Pteropus conspicillatus</i>) affected by tick paralysis between 1998 and 2010 and population counts of <i>P. conspicillatus</i>.

*<p>Affected animals from Tolga scrub, Whiteing Road, and New Powley Road on the Atherton Tableland, North Queensland, Australia; **2006 count is taken from December and includes Lakeside a new camp affected by tick paralysis; ^$Animals moved to new unknown camp (Lakeside) so searches were incomplete in 2006; ^$$No details about numbers of dead adult animals available, as too many juvenile animals were in care; number of adult <i>P. conspicillatus</i> given were extrapolated from previous data; <b>^#</b>Search for affected animals stopped for 3 weeks because too many juveniles were in care; number of adult and juvenile animals based on seasonal distribution of previous years.</p

Distribution of spectacled flying-fox camps in the central Wet Tropics region, Atherton Tablelands, North Queensland, Australia.

<p>The distribution of rainforest is shown in grey. Enclosed area is the core distribution of <i>Solanum mauritianum</i> based on Queensland herbarium records for the Atherton Tableland (Source: Wikipedia; <a href="http://en.wikipedia.org/wiki/Australia" target="_blank">http://en.wikipedia.org/wiki/Australia</a>; commons map; and CSIRO, Australia).</p

Juvenile <i>Pteropus conspicillatus</i> tick paralysis rate per 10,000 population per year, and total <i>P. conspicillatus</i> tick paralysis rate per 10,000 population per year in the affected camps as well as total population of affected camps over the 13 year study period.

<p>Juvenile <i>Pteropus conspicillatus</i> tick paralysis rate per 10,000 population per year, and total <i>P. conspicillatus</i> tick paralysis rate per 10,000 population per year in the affected camps as well as total population of affected camps over the 13 year study period.</p