A Method for Routine PM\u3csub\u3e2.5\u3c/sub\u3e Obsercation and Incorporation into Numerical Weather Prediction

Operational numerical weather prediction (NWP) simulates aerosol abundance using climatic emission inventories due to a lack of available real-time observation. An advocation to monitor aerosol number concentration with a standardized global sensor network is defended. A comparison between observations from the existing network “PurpleAir” and condensation particle counters (CPC) reveals the necessity of regulated instrumentation when measuring aerosol number concentration. NWP initialization by the Goddard Chemistry Aerosol Radiation and Transport (GOCART) module is capable of augmentation by hourly aerosol observation. The disparity between observed in-situ particulate matter smaller than 2.5-μm in diameter (PM2.5) and Weather Research and Forecasting with Chemistry (WRF-Chem) output—with GOCART—can be reduced via this modification. Analysis is done on WRF-Chem output near Dayton, Ohio after CPC data is manually inserted as WRF-Chem input at the surface. Upon confirmation of PM2.5 characterization improvement by point-observation initialization, a method of integrating PM2.5 abundance into the long-standing meteorological observation network is suggested: encoding of PM2.5 number concentration in the routine meteorological aerodrome report (METAR) as an estimate of horizontal visibility

Investigation of the Mechanism in Rijke Pulse Combustors with Tangential Air and Fuel Injection. Final Report

To study the mechanisms that control the operation of this combustor, an experimental setup is developed with access for detailed optical measurements. Propane is employed as fuel because the absence of liquid drops and combustion generated particulates in the combustion region significantly simplifies the optical diagnostics. The experimental techniques utilized include acoustic pressure measurements, space and time resolved radiation measurements, steady temperature measurements, exhaust flow chemical analysis, high speed video and intensified images of the reacting flow field by a computer based CCD camera imaging system. Flow visualization by the imaging system and the results from radiation intensity distribution measurements suggest that the periodic combustion processes caused by periodic vortex shedding and impingement provide the energy required to sustain the pressure oscillations. High radiation intensity occurs during a relatively short period of time and is in phase with the pressure oscillations, indicating that Rayleigh`s criterion is satisfied. Periodic variations of the air and fuel flow rates and, consequently, the air/fuel ratio of the reacting mixture inside the combustor appear to be another mechanism that contributes to the occurrence of periodic combustion and heat release processes. The presence of this mechanism has been uncovered by acoustic pressure measurements that revealed the presence of traveling pressure waves inside the air and fuel feed lines. These traveling waves produce periodic fuel and air feed rates which, in turn, result in periodic combustion and heat release processes within the combustor

Quantification of methane emission rate from oil and gas wells in Romania using ground-based measurement techniques

The ROMEO campaign (ROmanian Methane Emissions from Oil and gas) focused on measurements of methane (CH4) emission rates from oil and natural gas (O&G) production in Romania. The campaign took place in October 2019 and covered the southern part of Romania around the cities Bucharest, Ploiesti, Pitesti, and Craiova. This study presents emission rates calculated from mobile in situ measurement of CH4 and wind measurements using the Other Test Method 33a from U.S. Environmental Protection Agency and the Gaussian Plume Method. These methods were used to determine emission rates from 112 O&G well sites and other production-related facilities. Estimated mean CH4 emission rate with a 95% confidence interval equals 0.49 [0.35, 0.71] kg CH4 h-1 per site; 10% of all quantified sites account for 56% of the estimated emission rates. In addition, more than 1,000 O&G sites were visited for a qualitative “screening” (CH4 detection without quantification). Analysis of the screening data shows that 65% of the sites emitted methane at detectable rates. The CH4 emission rates obtained during the ROMEO campaign are comparable to the methane emission rates in study carried out in other Romanian regions

Initiation of Aspirin Therapy Modulates Angiogenic Protein Levels in Women with Breast Cancer Receiving Tamoxifen Therapy

Abstract Aspirin has a range of antineoplastic properties linked to inhibition of cyclooxygenase enzymes in tumor cells, platelet inhibition and to inhibition of angiogenesis. We undertook a prospective study to determine the influence of a 45‐day course of aspirin therapy on circulating and intraplatelet levels of selected proangiogenic (vascular endothelial growth factor [VEGF]) and antiangiogenic (thrombospondin‐1 [TSP‐1]) proteins, and platelet protein release in women diagnosed with breast cancer who were receiving tamoxifen therapy. Initiation of aspirin therapy increases serum and intraplatelet levels of TSP‐1 without a corresponding increase in VEGF levels. Following aspirin therapy, VEGF levels decreased (relative to pretreatment levels) while TSP‐1 returned to pretreatment levels. Plasma TSP‐1 and VEGF levels did not change on aspirin therapy. Aspirin use also decreased thrombin receptor mediated release of TSP‐1 and VEGF from platelets. The selective impact on platelet angiogenic protein content and release supports one mechanism by which aspirin can modify the angiogenic balance in women receiving tamoxifen therapy. Aspirin therapy appears to favor an overall antiangiogenic balance in women with breast cancer who are receiving tamoxifen therapy

Composite Materials Infiltrated by Aluminium Alloys Based on Porous Skeletons from Alumina, Mullite and Titanium Produced by Powder Metallurgy Techniques

The infiltration technology with reinforcement in the form of porous skeletons fabricated with powder metallurgy methods has been presented in relation to the general characteristics of metal alloy matrix composite materials. The results of our own investigations are presented pertaining to four alternative technologies of fabrication of porous, sintered skeletons, and their structure and their key technological properties are presented. Porous skeletons made of Al2O3 aluminium are sintered reactively using blowing agents or are manufactured by ceramic injection moulding (CIM) from powder. Porous skeletons made of 3Al2O3⋅2SiO2 mullite are achieved by sintering a mixture of halloysite nanotubes together with agents forming an open structure of pores. Titanium porous skeletons are achieved by selective laser sintering (SLS). The structure and properties of composite materials with an aluminium alloy matrix—mainly EN AC-AlSi12 and also EN AC-AlSi7Mg0.3 alloys—reinforced with the so manufactured skeletons are also described. A unique structure of the achieved composite materials, together with good mechanical properties and abrasive wear resistance at low density, ensured by an aluminium alloy matrix, are indicating broad application possibilities of such composites

Respiratorni simptomi u radnica na preradi riba na obali Jadrana u Hrvatskoj

This article describes respiratory symptoms and lung function in 98 fish processing female workers employed in a fish processing plant located on the Croatian Adriatic coast and 95 matching controls. The study included chronic and acute respiratory symptoms which developed during the shifts. Lung function measurements included forced vital capacity (FVC), one-second forced expiratory volume (FEV1) and maximal expiratory rates at 50 % and the last 25 % (FEF50, FEF25). Chronic respiratory symptoms were significantly dominant in fish processing workers compared to controls. The most common chronic symptoms were hoarseness (57.1 %), nasal catarrh (51.0 %), chronic cough (42.9 %), chronic phlegm (34.7 %), and frequent chest cold (35.7 %). Exposed smokers and nonsmokers had a similar prevalence of chronic respiratory symptoms. Acute symptoms over the work shift were high, with headache in lead (smokers: 62.5 %; nonsmokers: 56.1 %). Most of the ventilatory capacity parameters were significantly lower than predicted, FEF25 in particular, indicating obstructive changes predominantly in the smaller airways. These findings suggest that fish processing workers are prone to developing acute and chronic respiratory symptoms as well as to lung function changes. This calls for medical and technical preventive measures to be introduced in the work environment of the fi sh processing plant.Cilj je ovoga istraživanja bio ispitati respiratorne simptome i plućnu funkciju radnica zaposlenih na preradi riba u industriji na obali Jadranskog mora u Hrvatskoj. U istraživanje je uključeno 98 radnica zaposlenih na preradi riba i 95 žena neizložene kontrolne skupine. Ispitivani su kronični i akutni respiratorni simptomi koji se razvijaju tijekom radne smjene. Mjerena je plućna funkcija registriranjem forsiranoga vitalnog kapaciteta (FVC), forsiranoga ekspiracijskog volumena u prvoj sekundi (FEV1) te maksimalnoga ekspiracijskog protoka pri 50 % i zadnjih 25 % forsiranoga vitalnog kapaciteta (FEF50, FEF25) na krivulji maksimalni ekspiracijski protok-volumen (MEPV). Učestalost većine kroničnih respiracijskih simptoma bila je značajno viša u eksponiranih u usporedbi s kontrolnom skupinom. U eksponiranih radnica utvrđena je i visoka prevalencija akutnih simptoma koji se razvijaju tijekom radne smjene, posebno za promuklost (57,1 %) i katar nosa (51 %), potom slijedi kronični kašalj (42,9 %), kronični iskašljaj (34,7 %), upale sinusa (32 %) i česte prehlade (35,7 %). S obzirom na naviku pušenja pušači i nepušači imali su sličnu prevalenciju kroničnih respiratornih simptoma. Izložene radnice imale su visoku prevalenciju akutnih simptoma tijekom radne smjene i to naročito za glavobolju (pušači 62,5 %; nepušači 56,1 %). Ventilacijska funkcija pluća bila je značajno smanjena u usporedbi s predviđenim normalnim vrijednostima posebice za FEF25 % upućujući na opstruktivne promjene pretežno u manjim dišnim putovima. Naši podaci upućuju na opasnost razvoja kroničnih i akutnih respiracijskih simptoma i promjena plućne funkcije u radnika koji rade u industriji na preradi riba. Medicinske i tehničke preventivne mjere u radnom okolišu treba preporučiti u industriji prerade riba

The Distribution of Quasars and Galaxies in Radio Color-Color and Morphology Diagrams

We positionally match the 6 cm GB6, 20 cm FIRST and NVSS, and 92 cm WENSS radio catalogs and find 16,500 matches in ~3,000 deg2 of sky. Using this unified radio database, we construct radio "color-magnitude-morphology" diagrams and find that they display a clear structure, rather than a random scatter. We propose a simple, yet powerful, method for morphological classification of radio sources based on FIRST and NVSS measurements. For a subset of matched sources, we find optical identifications using the SDSS Data Release 1 catalogs, and separate them into quasars and galaxies. Compact radio sources with flat radio spectra are dominated by quasars, while compact sources with steep spectra, and resolved radio sources, contain substantial numbers of both quasars and galaxies.Comment: 4 pages, 2 figures, to be published in the Proceedings of "Multiwavelength AGN Surveys", Cozumel, Dec 8 - 12, 200

Self-Association of Organic Solutes in Solution: A NEXAFS Study of Aqueous Imidazole

N K-edge near-edge X-ray absorption fine-structure (NEXAFS) spectra of imidazole in concentrated aqueous solutions have been acquired. The NEXAFS spectra of the solution species differ significantly from those of imidazole monomers in the gas phase and in the solid state of imidazole, demonstrating the strong sensitivity of NEXAFS to the local chemical and structural environment. In a concentration range from 0.5 to 8.2 mol L−1 the NEXAFS spectrum of aqueous imidazole does not change strongly, confirming previous suggestions that imidazole self-associates are already present at concentrations more dilute than the range investigated here. We show that various types of electronic structure calculations (Gaussian, StoBe, CASTEP) provide a consistent and complete interpretation of all features in the gas phase and solid state spectra based on ground state electronic structure. This suggests that such computational modelling of experimental NEXAFS will permit an incisive analysis of the molecular interactions of organic solutes in solutions. It is confirmed that microhydrated clusters with a single imidazole molecule are poor models of imidazole in aqueous solution. Our analysis indicates that models including both a hydrogen-bonded network of hydrate molecules, and imidazole–imidazole interactions, are necessary to explain the electronic structure evident in the NEXAFS spectra

Synthesis of Fluorine-18 Functionalized Nanoparticles for use as in vivo Molecular Imaging Agents

Nanoparticles containing fluorine-18 were prepared from block copolymers made by ring opening metathesis polymerization (ROMP). Using the fast initiating ruthenium metathesis catalyst (H_2IMes)(pyr)_2(Cl)_2Ru=CHPh, low polydispersity amphiphilic block copolymers were prepared from a cinnamoyl-containing hydrophobic norbornene monomer and a mesyl-terminated PEG-containing hydrophilic norbornene monomer. Self-assembly into micelles and subsequent cross-linking of the micelle cores by light-activated dimerization of the cinnamoyl groups yielded stable nanoparticles. Incorporation of fluorine-18 was achieved by nucleophilic displacement of the mesylates by the radioactive fluoride ion with 31% incorporation of radioactivity. The resulting positron-emitting nanoparticles are to be used as in vivo molecular imaging agents for use in tumor imaging