47 research outputs found
âContrivedâ: The Voting Rights Act Pretext for the Trump Administrationâs Failed Attempt to Add a Citizenship Question to the 2020 Census
A Pretext . . . For What?
In March 2018, Commerce Secretary Wilbur Ross announced that the Trump Administration would add a question to the 2020 census asking the citizenship status of all persons in the United States. The question, Secretary Ross asserted, would generate âcomplete and accurate [citizenship] dataâ that the Department of Justice (DOJ) could use to better enforce Section 2 of the Voting Rights Act of 1965 (VRA)âa law that sometimes requires states and localities to draw districts in which voters of color make up a majority of the voting age population (so-called âmajority-minorityâ districts)
Application of Headspace Solid-Phase Microextraction for Determination of Chloro-Organic Compounds in Sewage Samples
Solid phase microextraction (SPME) has been optimized and applied to the determination of the volatile halogenated compounds (VHCs) and semi-volatile halogenated compounds (SVHCs). Three types of SPME fiber coated with different stationary phases (PDMSâ100 ÎŒm, CAR/PDMS-75 ÎŒm, PDMS/DVBâ65 ÎŒm) were used to examine their extraction efficiencies for the compounds tested. Experimental parameters such as the selection of SPME coatings, extraction time, and addition of salts were studied. The carboxen-polydimethylsiloxane (CAR/PDMS) fiber appears to be the most suitable for the determination of VHCs. Analytical parameters such as linearity, limit of detection, and precision were also evaluated. Application of ECD detector for the determination of VHCs and SVHCs allows their determination on the low concentration level, ranging from 0.005 to 0.8 ÎŒg/Lâ1. The HS-SPME-GC/ECD procedure gave good analytical precision expressed as relative standard deviation (RSD) (ranged from 5.08% to 8.07%) for a concentration level of 5 ÎŒg/Lâ1 and good linearity (r2 > 0.98) in a wide calibration range. The applied HS-SPME-GC/ECD method was found to be a quick and effective technique for the determination of microtrace amounts of volatile and semi-volatile halogenated compounds in samples containing high amounts of various organic compounds
Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition
Secondary organic aerosol (SOA) accounts for a large fraction of submicron
particles in the atmosphere. SOA can occur in amorphous solid or semi-solid
phase states depending on chemical composition, relative humidity (RH), and
temperature. The phase transition between amorphous solid and semi-solid
states occurs at the glass transition temperature (Tg). We have
recently developed a method to estimate Tg of pure compounds
containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass
less than 450âŻgâŻmolâ1 based on their molar mass and atomic OâŻ:âŻC
ratio. In this study, we refine and extend this method for CH and CHO
compounds with molar mass up to âŒâ1100âŻgâŻmolâ1 using the number
of carbon, hydrogen, and oxygen atoms. We predict viscosity from the
Tg-scaled Arrhenius plot of fragility (viscosity vs.
TgâT) as a function of the fragility parameter D. We compiled
D values of organic compounds from the literature and found that D
approaches a lower limit of âŒâ10 (±1.7) as the molar mass
increases. We estimated the viscosity of α-pinene and isoprene SOA as
a function of RH by accounting for the hygroscopic growth of SOA and applying
the GordonâTaylor mixing rule, reproducing previously published experimental
measurements very well. Sensitivity studies were conducted to evaluate
impacts of Tg, D, the hygroscopicity parameter (Îș), and
the GordonâTaylor constant on viscosity predictions. The viscosity of
toluene SOA was predicted using the elemental composition obtained by
high-resolution mass spectrometry (HRMS), resulting in a good agreement with
the measured viscosity. We also estimated the viscosity of biomass burning
particles using the chemical composition measured by HRMS with two different
ionization techniques: electrospray ionization (ESI) and atmospheric pressure
photoionization (APPI). Due to differences in detected organic compounds and
signal intensity, predicted viscosities at low RH based on ESI and APPI
measurements differ by 2â5 orders of magnitude. Complementary measurements
of viscosity and chemical composition are desired to further constrain
RH-dependent viscosity in future studies
Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition
Secondary organic aerosol (SOA) accounts for a large fraction of submicron
particles in the atmosphere. SOA can occur in amorphous solid or semi-solid
phase states depending on chemical composition, relative humidity (RH), and
temperature. The phase transition between amorphous solid and semi-solid
states occurs at the glass transition temperature (Tg). We have
recently developed a method to estimate Tg of pure compounds
containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass
less than 450âŻgâŻmolâ1 based on their molar mass and atomic OâŻ:âŻC
ratio. In this study, we refine and extend this method for CH and CHO
compounds with molar mass up to âŒâ1100âŻgâŻmolâ1 using the number
of carbon, hydrogen, and oxygen atoms. We predict viscosity from the
Tg-scaled Arrhenius plot of fragility (viscosity vs.
TgâT) as a function of the fragility parameter D. We compiled
D values of organic compounds from the literature and found that D
approaches a lower limit of âŒâ10 (±1.7) as the molar mass
increases. We estimated the viscosity of α-pinene and isoprene SOA as
a function of RH by accounting for the hygroscopic growth of SOA and applying
the GordonâTaylor mixing rule, reproducing previously published experimental
measurements very well. Sensitivity studies were conducted to evaluate
impacts of Tg, D, the hygroscopicity parameter (Îș), and
the GordonâTaylor constant on viscosity predictions. The viscosity of
toluene SOA was predicted using the elemental composition obtained by
high-resolution mass spectrometry (HRMS), resulting in a good agreement with
the measured viscosity. We also estimated the viscosity of biomass burning
particles using the chemical composition measured by HRMS with two different
ionization techniques: electrospray ionization (ESI) and atmospheric pressure
photoionization (APPI). Due to differences in detected organic compounds and
signal intensity, predicted viscosities at low RH based on ESI and APPI
measurements differ by 2â5 orders of magnitude. Complementary measurements
of viscosity and chemical composition are desired to further constrain
RH-dependent viscosity in future studies
The Graduate School WATERS - WATer, Ecosystems, Resources in Societies â in Montpellier
International audienc
Results of curative strategy in patients with peritoneal and extraperitoneal metastases from colorectal cancer
Winter and Spring Characterization of Particulate and Dissolved Organic Matter in the Danube-Black Sea Mixing Zone.
Abstract not availableJRC.H-Institute for environment and sustainability (Ispra