The Effects of Oxidized Biodiesel Fuel on Fatty Acid Methyl Ester Composition and Particulate Matter Emissions from a Light-Duty Diesel Engine

Diesel particulate matter (PM) is classified by the EPA as carcinogenic, with the transportation sector largely responsible these emissions within the United States. Biodiesel (B100) is derived from renewable sources, providing similar chemical composition to diesel fuel and is in the current diesel supply up to 5% across the nation. However, biodiesel has an inherent oxidation issue due to the unique mixture of fatty acid methyl ester (FAME) molecules present in the biodiesel that are not in diesel. Biodiesel oxidation can only be delayed, and the inevitable process results in changes to the original fuel composition that may alter emissions profiles. There have been limited studies on the effect of oxidized biodiesel fuel on PM emissions, and with increasing biodiesel production volumes, it is important to assess due to possible adverse human health effects. In this study, it was hypothesized that the change in fuel composition due to oxidation would lead to lower PM emissions because the presence of more fuel oxygen molecules and secondary oxidation products would enhance self-combustion characteristics. In this study, PM mass generated from a light-duty diesel engine running on three different fuel types—pure (“neat”) B100 biodiesel, pure B0 diesel, and B20 (20% v/v biodiesel blend with diesel)—was quantified and compared to the PM mass (and concentrations) from repeated emissions testing using artificially oxidized B100 and B20 biodiesel as the fuel source. B100 fuel was heated at 110oC for 5, 10, and 20 hours (“oxidation states” 3, 2, and 1, respectively), verifying the extent of fuel oxidation by building an apparatus (Biodiesel Oxidation Stability Surveyor, BOSS) that quantified the biodiesel fuel’s oxidative stability using a method equivalent to standard methods for determining the biofuel’s induction period. Induction period increased linearly with time spent under the artificial oxidation conditions. A custom, load-based steady-state modal drive cycle was specially developed for emissions testing each neat and oxidized B100 and B20 fuel type in a light-duty diesel engine dynamometer. Observed changes in PM mass with increased fuel oxidation time occurred only for B20 fuel with a 51 ±13% decrease. Fuel properties such as cetane number, biodiesel content, density, and total aromatics were compared between neat and oxidized B20 and B100 samples. Cetane number increased 7% from 66.8 to 71.7 from B100 neat to B100 OX1 (20hrs) and density increased from 0.709g/cm3 to 0.723g/cm3. Chemical analysis of the biodiesel fuels by gas chromatography mass spectrometry (GCMS) quantified individual FAME compounds to determine key species involved in fuel oxidation. B100 FAME concentration widely varied, however, the B20 fuel blend showed that 20 hour artificial oxidation treatment decreased concentrations of the unsaturated FAMEs for C18:3n3, C18:2 cis-9,12, C18:1 (both cis- and trans- isomers) by 41.7 ±3.5%, 33.25 ±8.8%, and 21.9 ±6.9% relative to their initial concentration in the unoxidized fuel, respectively, in general agreement with literature values. The findings of this study help contribute a better understanding of oxidation effects on biodiesel fuel and link together fuel properties, chemical composition, and particulate emissions whereas most literature excludes detailed analysis of biodiesel fuel composition and associated emissions effects

Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at root s=13 TeV

Measurements of Higgs boson production cross sections and couplings in events where the Higgs boson decays into a pair of photons are reported. Events are selected from a sample of proton-proton collisions at root s = 13TeV collected by the CMS detector at the LHC from 2016 to 2018, corresponding to an integrated luminosity of 137 fb(-1). Analysis categories enriched in Higgs boson events produced via gluon fusion, vector boson fusion, vector boson associated production, and production associated with top quarks are constructed. The total Higgs boson signal strength, relative to the standard model (SM) prediction, is measured to be 1.12 +/- 0.09. Other properties of the Higgs boson are measured, including SM signal strength modifiers, production cross sections, and its couplings to other particles. These include the most precise measurements of gluon fusion and vector boson fusion Higgs boson production in several different kinematic regions, the first measurement of Higgs boson production in association with a top quark pair in five regions of the Higgs boson transverse momentum, and an upper limit on the rate of Higgs boson production in association with a single top quark. All results are found to be in agreement with the SM expectations.Peer reviewe

Search for lepton-flavor violating decays of the Higgs boson in the mu tau and e tau final states in proton-proton collisions at root s=13 TeV

A search is presented for lepton-flavor violating decays of the Higgs boson to mu t and et. The dataset corresponds to an integrated luminosity of 137 fb(-1) collected at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV. No significant excess has been found, and the results are interpreted in terms of upper limits on lepton-flavor violating branching fractions of the Higgs boson. The observed (expected) upper limits on the branching fractions are, respectively, B(H -> mu t) e tau) < 0.22(0.16)% at 95% confidence level.Peer reviewe

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Search for charged Higgs bosons produced in vector boson fusion processes and decaying into vector boson pairs in proton-proton collisions at root s=13 TeV

A search for charged Higgs bosons produced in vector boson fusion processes and decaying into vector bosons, using proton-proton collisions at root s = 13 TeV at the LHC, is reported. The data sample corresponds to an integrated luminosity of 137 fb(-1) collected with the CMS detector. Events are selected by requiring two or three electrons or muons, moderate missing transverse momentum, and two jets with a large rapidity separation and a large dijet mass. No excess of events with respect to the standard model background predictions is observed. Model independent upper limits at 95% confidence level are reported on the product of the cross section and branching fraction for vector boson fusion production of charged Higgs bosons as a function of mass, from 200 to 3000 GeV. The results are interpreted in the context of the Georgi-Machacek model.Peer reviewe

Os Contornos e o Entorno da Nova Sociologia da Moral

Neste ensaio vou expor brevemente como vejo o desenvolvimento do campo da Sociologia da Moral, com foco em seu potencial fundamentalmente interdisciplinar, destacando os estudos e tradições que merecem ser incorporados à sociologia. A moral, como tema de investigação da ciência social, perpassa os campos da psicologia (social e do desenvolvimento), sociologia, antropologia, neurociências e economia. Aqueles entre nós implicados no seu desenvolvimento afirmam que ela serve de fundamento para toda a organização e interação social. Assumo, implicitamente, a posição do filósofo Charles Taylor e do sociólogo Christian Smith de que os seres humanos vivem envolvidos em teias de significados, pelas quais são moldados, conforme versões de "certo" e de "bem". Os seres humanos são fundamentalmente morais, não no sentido de serem convencionalmente altruístas ou de se preocuparem com os outros, mas de que as pessoas humanas, por serem seres sociais habitando um espaço social, devem assumir posições sobre temas relevantes nessas sociedades e grupos. As pessoas, de um modo geral, nesse meu paradigma, ancoram seus sentidos de si em posicionamentos morais, padrões que oferecem um solo a partir do qual dão sentido ao mundo através de lentes morais. Uma sociologia da moral compreende a formação dessas crenças, sua relativa imutabilidade ou as circunstâncias pelas quais elas mudam, sua influência sobre a ação e sua reconstrução retrospectiva diante de efeitos desajustados ou de pressões sociais