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Under the next cycle of target setting under the Paris Agreement, countries will be updating and submitting new nationally determined contributions (NDCs) over the coming year. To this end, there is a growing need for the United States to assess potential pathways toward a new, maximally ambitious 2035 NDC. In this study, we use an integrated assessment model with state-level detail to model existing policies from both federal and non-federal actors, including the Inflation Reduction Act, Bipartisan Infrastructure Law, and key state policies, across all sectors and gases. Additionally, we develop a high-ambition scenario, which includes new and enhanced policies from these actors. We find that existing policies can reduce net greenhouse gas (GHG) emissions by 44% (with a range of 37% to 52%) by 2035, relative to 2005 levels. The high-ambition scenario can deliver net GHG reductions up to 65% (with a range of 59% to 71%) by 2035 under accelerated implementation of federal regulations and investments, as well as state policies such as renewable portfolio standards, EV sales targets, and zero-emission appliance standards. This level of reductions would provide a basis for continued progress toward the country's 2050 net-zero emissions goal.
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The objective was to determine how the prevalence of obesity among children in pediatric practices in South Carolina varied from national data. Children were sampled from the South Carolina Pediatric Practice Research Network (SCPPRN) using measured weight and height, and these data were compared with national data. Children were categorized as obese if their BMI exceeded the 95th percentile. Age was stratified according to national data (2-5 years, 6-11 years, and 12-19 years). Comparisons were made by age, gender, and race/ethnicity. The prevalence of obese children in the SCPPRN aged 2 to 5 years was 14%, 6 to 11 years was 21.7%, and 12 to 19 years was 17.3%. National comparison rates were 13.9%, 18.8%, and 17.4%, respectively. Gender and racial disparity were present, with black boys and white girls having a high prevalence of obesity early in life, which decreased in adolescence. Black girls had the opposite course. Obesity prevalence varied among practices, from 7.5% to 26.9%.
Assuntos
Índice de Massa Corporal , Peso Corporal , Obesidade/epidemiologia , Adolescente , Criança , Feminino , Humanos , Masculino , Obesidade/diagnóstico , Prevalência , Estudos de Amostragem , South Carolina/epidemiologia , Estados Unidos/epidemiologiaAssuntos
Cefaleia/diagnóstico , Acetaminofen/uso terapêutico , Adolescente , Fatores Etários , Analgésicos/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Criança , Pré-Escolar , Estudos Epidemiológicos , Feminino , Cefaleia/tratamento farmacológico , Cefaleia/epidemiologia , Humanos , Ibuprofeno/uso terapêutico , Masculino , Prevalência , Fatores de Risco , South Carolina/epidemiologia , Estados Unidos/epidemiologiaRESUMO
Metal films with patterns of subwavelength holes (grids or meshes) have interesting optical properties including the extraordinary transmission effect. These optically thick metal films transmit more radiation than that incident on the holes owing to the excitation of surface plasmons (SPs). Meshes present a new and simple way to excite SPs at perpendicular incidence (i.e., without the need to vary the angle of the incident beam). This represents a new opportunity to integrate SPs with experiments and devices-a new instrument in the toolbox of SP techniques that may broaden the range of SP applications. This review discusses the discovery, basic optical physics, the role of SPs, and applications of the extraordinary transmission of subwavelength hole arrays.
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The interaction of an infrared surface plasmon and an excited molecular vibration was investigated by using a square array of subwavelength holes in a Ni film which supports propagating, surface-plasmon-mediated, transmission resonances. The largest transmission resonance [the (1,0)(-)] was tuned through the rocking vibration of the hexadecane molecule (at 721 cm(-1)) in a hexadecane film on the mesh by varying the thickness of the film. The interaction of the rocking vibration and surface plasmon is characterized spectroscopically by an increase in the intensity of the vibrational band by more than a factor of 2, variation of the vibrational line shape relative to the spectrum on a nonmetallic surface, and shifts in vibrational peak position by as much as 3.0 cm(-1). Relationships are developed between the transmission resonance position and the thickness and dielectric properties of the coating.
Assuntos
Alcanos/química , Membranas Artificiais , Níquel/química , Ressonância de Plasmônio de Superfície/métodos , Raios Infravermelhos , VibraçãoRESUMO
Reliable thermochemistry is computed for infinite stretches of pure-carbon materials including acetylenic and cumulenic carbon chains, graphene sheet, and single-walled carbon nanotubes (SWCNTs) by connection to the properties of finite size molecules that grow into the infinitely long systems. Using ab initio G3 theory, the infinite cumulenic chain (:C[double bond]C[double bond]C[double bond]C:) is found to be 1.9+/-0.4 kcal/mol per carbon less stable in free energy at room temperature than the acetylenic chain (.C[triple bond]C-C[triple bond]C.) which is 24.0 kcal/mol less stable than graphite. The difference between carbon-carbon triple, double, and single bond lengths (1.257, 1.279, and 1.333 A, respectively) in infinite chains is evident but much less than with small hydrocarbon molecules. These results are used to evaluate the efficacy of similar calculations with the less rigorous PM3 semiempirical method on the (5,5) SWCNT, which is too large to be studied with high-level ab initio methods. The equilibrium electronic energy change for C(g)-->C[infinite (5,5) SWCNT] is -166.7 kcal/mol, while the corresponding free energy change at room temperature is -153.3 kcal/mol (6.7 kcal/mol less stable than graphite). A threefold alternation (6.866, 6.866, and 6.823 A) in the ring diameter of the equilibrium structure of infinitely long (5,5) SWCNT is apparent, although the stability of this structure over the constant diameter structure is small compared to the zero point energy of the nanotube. In general, different (n,m) SWCNTs have different infinite tube energetics, as well as very different energetic trends that vary significantly with length, diameter, and capping.
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The flow of polarized light through a metal film with an array of microchannels is controlled by the phase of an optically active, phospholipid nanocoating, even though the coating does not cover the open area of the microchannels. The molecular details of the assembly (DPPC phospholipid monolayer/bilayer on a hexadecanethiol monolayer on a copper- or nickel-coated microarray) were determined using the infrared, surface-plasmon-mediated, extraordinary transmission of the metal microarrays. Infrared absorption spectra with greatly enhanced absorptions by comparison to literature were recorded and used as a diagnostic for the phase, composition, and molecular geometry of these nanocoatings. This approach presents new tools for nanoscale construction in constricted microspaces, which may ultimately be useful with individual microchannels.
Assuntos
Cobre/química , Luz , Nanoestruturas/química , Níquel/química , Fosfolipídeos/química , Modelos Moleculares , Estrutura Molecular , Nanoestruturas/ultraestrutura , Transição de FaseRESUMO
The surface-plasmon-mediated, extraordinary transmission of metallic arrays of subwavelength apertures has been used as the light source for absorption studies of self-assembled monolayers on metal. Enhanced infrared absorption spectra of a sequence of alkanethiol self-assembled monolayers on copper were recorded for carbon chain lengths varying from 8 to 18 atoms. Transition positions and intensities are presented over a large range of the infrared region. The connection between the vibrational modes of the CH(2) wagging progression and the infinite methylene chain is explored using a traditional coupled oscillator approach and a new cluster perspective.