Suchergebnisse

This study aimed to investigate the influence of flash-boiling conditions on liquid propane sprays formed by a multi-hole injector at various injection pressures. The focus was on spray struc-tures, which were analysed qualitatively and quantitatively by means of spray-tip penetration and global spray angle. The effect of flash boiling was evaluated in terms of trends observed for sub-cooled conditions. Propane was injected by a commercial gasoline direct injector into a constant volume vessel filled with nitrogen at pressures from 0.1 MPa up to 6 MPa. The temperature of the injected liquid was kept constant. The evolution of the spray penetration was observed by a high-speed camera with a Schlieren set-up. The obtained results provided information on the spray evolution in both regimes, above and below the saturation pressure of the propane. Based on the experimental results, an attempt to calibrate a simulation model has been made. The main advantage of the study is that the effects of injection pressure on the formation of propane sprays were inves-tigated for both subcooled and flash-boiling conditions. Moreover, the impact of the changing viscosity and surface tension was limited, as the temperature of the injected liquid was kept at the same level. The results showed that despite very different spray behaviours in the subcooled and flash-boiling regimes, leading to different spray structures and a spray collapse for strong flash boiling, the influence of injection pressure on propane sprays in terms of spray-tip penetration and spray angle is very similar for both conditions, subcooled and flash boiling. As for the numerical model, there were no single model settings to simulate the flashing sprays properly. Moreover, the spray collapse was not represented very well, making the simulation set-up more suitable for less superheated sprays. ; The project leading to this application has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie ...

Testimony issued by the Government Accountability Office with an abstract that begins "This testimony discusses highlights of our report on the extent to which the Propane Education and Research Council (PERC) and National Oilheat Research Alliance (NORA) implement consumer education, research and development, and safety and training programs related to the use of propane and heating oil. Tens of millions of Americans rely on propane and heating oil for heat, hot water and--in the case of propane--cooking and motor fuel. Within the last 15 years, Congress authorized the creation of two national entities to undertake propane and oilheat research and development, safety and training, and consumer education programs and provided the U.S. Department of Commerce (Commerce) and the U.S. Department of Energy (DOE) with certain related authority. The Propane Education and Research Act of 1996 (the Propane Act) and the National Oilheat Research Alliance Act of 2000 (the Oilheat Act) authorized the establishment of PERC and NORA, respectively. The Oilheat Act expired on February 6, 2010, and is under consideration for reauthorization, but the Propane Act does not expire. PERC and NORA fall into a category of federally-authorized programs known as check-off programs. To fund check-off programs, a fraction of the wholesale cost of a product is set aside by the producer and deposited into a common fund to be used to benefit producers and consumers. Similar programs are in place for agriculture commodities, including, for example, milk, as well as beef, pork, and cotton, among other commodities. To fund PERC operations, each gallon of odorized propane gas sold is assessed $0.005.5 To fund NORA operations, each gallon of heating oil sold is assessed $0.002."

The cobalt-based ZIF-67 has been evaluated for the adsorptive propylene/propane separation in a fixed bed. Characterization techniques and dynamic measurements have been performed over ZIF-67 to evaluate its potential in this defiant process. Cobalt promotes a more rigid framework than zinc in the isostructural ZIF-8. Although the adsorption affinity of ZIF-67 for both hydrocarbons is similar, the lower flexibility of the framework makes ZIF-67 behaving with a clear preference towards propane. This inverse selectivity promotes the enrichment in propylene content upon breakthrough, and may simplify the separation scheme. Therefore, ZIF-67 adsorptive separation is presented as an alternative to energy-demanding distillation. ; TU Delft is gratefully acknowledged for funding this research. This project has also received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 704473 of LOA.

A knowledge of blast wave parameters generated by detonating explosives is important for the evaluation of protective measures, modelling validation and post blast analysis. The relevant data are available for solid military explosives, but not for liquid or homemade explosives. In this contribution we present comparison of experimental incident blast wave parameters for bare charges, weighing from 100 g to 1 kg, of liquid esters of nitric acid, including propane-1,2,3-triyl trinitrate (NG), propane-1,2-diyl dinitrate (PGDN), ethane-1,2-diyl dinitrate (EGDN) and methyl nitrate (MeN), amongst themselves and with TNT charges of approximately the same size. The TNT equivalents, determined from both the incident overpressures and the impulse of the positive phase of the blast wave, were above 100% and showed relatively high scatter. The strongest blast wave parameters under otherwise identical conditions were observed for charges of methyl nitrate. ; Znalost parametrů vzdušných rázových vln (VRV) generovaných detonací výbušin je důležitá z hlediska ochranných opatření, validaci výpočetních modelů a povýbuchové analýzy. Relevantní data jsou k dispozici pro tuhé vojenské výbušiny, nikoliv však pro výbušiny kapalné či podomácku vyráběné. V tomto příspěvku předkládáme porovnání parametrů dopadajících VRV neutěsněných náloží kapalných nitroesterů propan-1,2,3-triyl trinitrátu (NG), propan-1,2-diyl dinitrátu (PGDN), ethan-1,2-diyl dinitrátu (EGDN) a methyl nitrátu (MeN) o hmotnostech 100g až 1kg. Porovnání je provedeno jak mezi estery navzájem, tak i oproti přibližně stejně velkých náloží TNT. TNT ekvivalenty stanoveny jak z dopadajícího přetlaku tak i z impulzu pozitivní fáze VRV jsou přes 100% a vykazují poměrně velký rozptyl. Nejvyšší parametry VRV při jinak identických podmínkách byly stanoveny pro nálože MeN.

This article belongs to the Special Issue Control of Fungal Diseases in Crops. ; Verticillium wilt, caused by Verticillium dahliae, is the most devastating soil-borne fungal disease of olive trees worldwide. Currently, there is no effective measure available to control the pathogen in diseased plants in open field conditions. Searching more effective and sustainable solutions are a priority for the olive sector. The existing alternatives for disease control include the use of biological control microorganisms and compounds of natural origin from plants, such as Alliaceae. Propyl propane thiosulfinate (PTS) and propyl propane thiosulfonate (PTSO) are two organosulfur compounds derived from Allium cepa with a widely documented antimicrobial activity. The aim of this study was to evaluate the antifungal activity of PTS and PTSO against the defoliating and non-defoliating V. dahliae pathotypes. Firstly, several in vitro tests were performed (Minimum Antifungal Concentration, susceptibility studies according to the Kirby–Bauer disk-diffusion method, antifungal activity through aerial diffusion and effect on mycelial growth). The ability of both compounds to sanitize soil was evaluated using a sterile substrate inoculated with V. dahliae. Finally, challenges in growth chambers were carried out. PTS and PTSO generated growth inhibition zones in agar diffusion and the gas phase, and the mycelial growth of all the V. dahliae strains was significantly altered. The V. dahliae population in soil was considerably reduced after the sanitization. Finally, in planta assays demonstrated the ability of these compounds to reduce disease related parameters and their contribution to control the phytopathogen. In conclusion, the results showed that the PTS and PTSO from Allium cepa display in vitro and in vivo antifungal activity against V. dahliae and suggested that both compounds could be used as natural and environmentally friendly tools for Verticillium wilt management. ; This research has been carried out within the project GRUPO OPERATIVO SALUD- OLIVAR from the Spanish Rural Development Program (2014–2020) funded by the Spanish Ministry of Agriculture, Fisheries and Food and co-financed by 80% by the European Agricultural Fund for Rural Development (FEADER) (Total investment 384.830,96 EUR). This study is part of the Industrial Doctorate of the doctoral student Ana Falcón Piñeiro, granted by the State Research Agency of the Spanish Government, with the following reference: DIN2019-010792.

Verticillium wilt, caused by Verticillium dahliae, is the most devastating soil-borne fungal disease of olive trees worldwide. Currently, there is no effective measure available to control the pathogen in diseased plants in open field conditions. Searching more effective and sustainable solutions are a priority for the olive sector. The existing alternatives for disease control include the use of biological control microorganisms and compounds of natural origin from plants, such as Alliaceae. Propyl propane thiosulfinate (PTS) and propyl propane thiosulfonate (PTSO) are two organosulfur compounds derived from Allium cepa with a widely documented antimicrobial activity. The aim of this study was to evaluate the antifungal activity of PTS and PTSO against the defoliating and non-defoliating V. dahliae pathotypes. Firstly, several in vitro tests were performed (Minimum Antifungal Concentration, susceptibility studies according to the Kirby–Bauer disk-diffusion method, antifungal activity through aerial diffusion and effect on mycelial growth). The ability of both compounds to sanitize soil was evaluated using a sterile substrate inoculated with V. dahliae. Finally, challenges in growth chambers were carried out. PTS and PTSO generated growth inhibition zones in agar diffusion and the gas phase, and the mycelial growth of all the V. dahliae strains was significantly altered. The V. dahliae population in soil was considerably reduced after the sanitization. Finally, in planta assays demonstrated the ability of these compounds to reduce disease related parameters and their contribution to control the phytopathogen. In conclusion, the results showed that the PTS and PTSO from Allium cepa display in vitro and in vivo antifungal activity against V. dahliae and suggested that both compounds could be used as natural and environmentally friendly tools for Verticillium wilt managemen ; This research has been carried out within the project GRUPO OPERATIVO SALUDOLIVAR from the Spanish Rural Development Program (2014–2020) funded by the Spanish Ministry of Agriculture, Fisheries and Food and co-financed by 80% by the European Agricultural Fund for Rural Development (FEADER) (Total investment 384.830,96 EUR). This study is part of the Industrial Doctorate of the doctoral student Ana Falcón Piñeiro, granted by the State Research Agency of the Spanish Government, with the following reference: DIN2019-010792 We would also like to acknowledge the work of Jose Manuel García-Madero in editing the text

The effect of accidental fires are simulated to understand the response of items such as vehicles, fuel tanks, and military ordnance and to remediate the effects through re-design of the items or changes in operational procedures. The comparative combustion emissions of using jet propellant (JP-5) liquid fuel pools or a propane manifold grid to simulate the effects of accidental fires was investigated. A helium-filled tethered aerostat was used to maneuver an instrument package into the open fire plumes to measure CO, CO2, fine particulate matter (PM2.5), polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and elemental/organic/total carbon (EC/OC/TC). The results showed that all emissions except CO2 were significantly higher from JP-5 burns than from propane. The major portion of the PM mass from fires of both fuels was less than 1 μm in diameter and differed in carbon content. The PM2.5 emission factor from JP-5 burns (129 ± 23 g/kg Fuelc) was approximately 150 times higher than the PM2.5 emission factor from propane burns (0.89 ± 0.21 g/kg Fuelc). The PAH emissions as well as some VOCs were more than one hundred times higher for the JP-5 burns than the propane burns. Using the propane test method to study flammability responses, the environmental impact of PM2.5, PAHs, and VOCs would be reduced by 2300, 700, and 100 times per test, respectively.

Separation of propylene/propane is one of the most challenging and energy consuming processes in the chemical industry. Propylene demand is increasing and a 99.5% purity is required for industrial purposes. Adsorption based solutions are the most promising alternatives to improve the economical/energetic efficiency of the process. Zeolitic Imidazolate Frameworks (ZIFs) combine the desired characteristics from both MOFs and zeolites: tunability and flexibility from metal organic frameworks, and exceptional thermal and chemical stability from zeolites. In order to enlighten the role of the cation in the sodalite ZIF-8 framework for propane/propylene separation, dynamic breakthrough measurements have been performed over ZIF-8(Zn), ZIF-67 (i.e. ZIF-8(Co)) and MUV-3 (i.e. ZIF-8(Fe)), all isostructural materials based on the same linker (2-methylimidazole). Cation substitution has a remarkable influence in the framework flexibility, and, consequently, in SOD-ZIF selectivity for light hydrocarbons. The differences between the crystallographic pore sizes of the material and the molecular dimensions of propane and propylene are so small, that the slightest change in the framework causes notable advantages/disadvantages in the final application. While cobalt is known to promote a more rigid framework resulting in an adsorption selectivity towards propane, iron presents the inverse effect yielding selectivity to propylene. Zinc has an intermediate effect. A threshold pressure in the isotherm is observed for propylene uptake by ZIF-67 at 273 and 298 K, and only at the lower temperature for ZIF-8. Inlet mixture composition does not highly influence the adsorptive selectivity, although it clearly affects the pure hydrocarbon recovery. Over ZIF-67 breakthrough experiments at 298 K yield a temporary pure propylene flow representing 10–15% of the amount fed. ZIF-67 is a promising candidate for propylene/propane adsorptive separation. ; TU Delft (The Netherlands) is gratefully acknowledged for funding this research. This project has also received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 704473 of LOA. We thank funding from the European Union (ERC-2016-CoG 724681-S-CAGE) and the Spanish MINECO (Structure of Excellence María de Maeztu MDM-2015-0538; projects CTQ2017-89528-P). G.M.E. thanks MICINN for a "Ramón y Cajal" J.L.-C. acknowledges the Universitat de València (Spain) for an "Atracció de Talent" grant.

Soot is an important component for heat transfer in combustion processes. However, it is also a harmful pollutant for humans, and strict emissions legislation motivates research on how to control soot formation and release. The formation of soot is known to be triggered by high temperature and high pressure during combustion, and it is also strongly influenced by the local stoichiometry. The current study investigates how the formation of soot is affected by increasing the oxygen concentration in the oxidizer, since this affects both the temperature profile and partial pressures of reactants. The oxygen-to-fuel ratio is kept constant, i.e., the total flow rate of the oxidizer decreases with increasing oxygen concentration. Propane is combusted (80 kWth) while applying oxygen-enriched air, and in-flame measurements of the temperature and gas concentrations are performed and combined with available soot measurements. The results show that increasing the oxygen concentration in the oxidizer from 21% to 27% slightly increases soot formation, due to higher temperatures or the lower momentum of the oxidizer. At 30% oxygen, however, soot formation increases by orders of magnitude. Detailed reaction modeling is performed and the increase in soot formation is captured by the model. Both the soot inception rates and surface growth rates are significantly increased by the changes in combustion conditions, with the increase in soot inception being the most important. Under atmospheric conditions, there is a distinct threshold for soot formation at around 1200 ° ; C for equivalence ratios > ; 3. The increase in temperature, and the slower mixing that results from the lower momentum of the oxidizer, have the potential to push the combustion conditions over this threshold when the oxygen concentration is increased.

The production of carbon-rich hydrocarbons via CO2 valorization is essential for the transition to renewable, non-fossil-fuel-based energy sources. However, most of the recent works in the state of the art are devoted to the formation of olefins and aromatics, ignoring the rest of the hydrocarbon commodities that, like propane, are essential to our economy. Hence, in this work, we have developed a highly active and selective PdZn/ZrO2+SAPO-34 multifunctional catalyst for the direct conversion of CO2 to propane. Our multifunctional system displays a total selectivity to propane higher than 50% (with 20% CO, 6% C1, 13% C2, 10% C4, and 1% C5) and a CO2 conversion close to 40% at 350 °C, 50 bar, and 1500 mL g–1 h–1. We attribute these results to the synergy between the intimately mixed PdZn/ZrO2 and SAPO-34 components that shifts the overall reaction equilibrium, boosting CO2 conversion and minimizing CO selectivity. Comparison to a PdZn/ZrO2+ZSM-5 system showed that propane selectivity is further boosted by the topology of SAPO-34. The presence of Pd in the catalyst drives paraffin production via hydrogenation, with more than 99.9% of the products being saturated hydrocarbons, offering very important advantages for the purification of the products. ; This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement 837733. The XAS measurements were supported by a public grant overseen by the French National Research Agency (ANR) as part of the "Investissements d'Avenir" program (reference: ANR-10-EQPX-45). The authors are grateful to C. La Fontaine and V. Briois, as well as to K. A. Lomachenko and A. Lazzarini for the help with the XAS experiment at ROCK, Soleil. Dr. Idoia Hita Del Olmo is acknowledged for her help with the TGA measurements. A.R., S.O.C., and J.G. acknowledge financial support from King Abdullah University of Science and Technology (KAUST). C.A.S. acknowledges the Norwegian Research Council for financial support through project no. 288331 (CO2LO). A.L.B. acknowledges the President's Grant of Russian Federation MK-5853.2021.1.2.