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We study the effects of Chapter 11 bankruptcy protection on competitive product pricing in both domestic and international markets using data from the airline industry. We find a decline of about 5% in domestic markets and an even more significant drop in international markets. Further, in international markets the competing carriers respond by dropping their prices as well, whereas they slightly increase them domestically. By contrast, existing literature considers only domestic markets finding a more moderate fare drop of about 3% in domestic markets by the bankrupt carrier, with mixed results on the fare drop by competitors. [ABSTRACT FROM AUTHOR]

Abstract This paper assesses whether Chapter 11 is a form of subsidy for US airlines. US airlines have used Chapter 11 to restructure their operations. This has been criticized as a subsidy by major non US airlines and governments for a long time and recently, in the "level playing field" debate. Applying legal and economic perspectives of subsidy, we examine the different opportunities of Chapter 11 to reduce airlines' costs. It is argued that most of the forms available, such as the modification of collective bargaining, do not constitute a subsidy. Only the termination of pension plans might involve a subsidy, but only using a legal definition of doubtful relevance since there is normally no use of public funds. Highlights • Major non US airlines and governments criticize Chapter 11 as a subsidy. • However, most of the forms of Chapter 11 do not constitute a subsidy. • Even the termination of pension plans does not normally involve a subsidy. [ABSTRACT FROM AUTHOR]

• Natural carbonate ores are promising for thermochemical hydrogen and energy storage. • Cheap, abundant and environmentally friendly storage material. • Large-scale energy storage in TWh-range. • Thorough experimental analysis as basis for system design. A stable energy supply will require balancing the fluctuations of renewable energy generation due to the transition to renewable energy sources. Intraday and seasonal storage systems are often limited to local geographical or infrastructural circumstances. This study experimentally verifies the application of inexpensive and abundant natural iron ores for energy storage with combined hydrogen and heat release. The incorporated iron oxides are reduced with hydrogen from electrolysis to store energy in chemically bonded form. The on–demand reoxidation releases either pure hydrogen or high-temperature heat as valuable products. Natural iron ores as storage material are beneficial as the specific costs are lower by an order of magnitude compared to synthetic iron oxide-based materials. Suitable iron ores were tested in TG analysis and in a 1 kW fixed-bed reactor. Siderite, a carbonate iron ore, was verified as promising candidate, as it shows significantly lower reaction temperatures and twice the storage capacity over other commercial iron ores such as ilmenite. The specific storage costs are as low as 80–150 $ per MWh hydrogen stored, based on the experimental in-situ tests. The experimentally determined volumetric energy storage capacity for the bulk material was 1.7 and 1.8 MWh m−3 for hydrogen and heat release, respectively. The raw siderite ore was stable for over 50 consecutive cycles at operating temperatures of 500–600 °C in in-situ lifetime tests. The combination of high abundance, low price and reasonable capacity can thus result in very low specific energy storage costs. The study proofs that suitable natural iron ores are an interesting economic solution for large-scale and seasonal energy storage systems. [ABSTRACT FROM AUTHOR]

One of the most fruitful and elegant approach (known as Kolosov-Muskhelishvili formulas) for plane isotropic elastic problems is to use two complex-valued holomorphic potentials. In this paper, the algebra of real quaternions is used in order to propose in three dimensions, an extension of the classical Muskhelishvili formulas. The starting point is the classical harmonic potential representation due to Papkovich and Neuber. Alike the classical complex formulation, two monogenic functions very similar to holomorphic functions in 2D and conserving many of interesting properties, are used in this contribution. The completeness of the potential formulation is demonstrated rigorously. Moreover, body forces, residual stress and thermal strain are taken into account as a left side term. The obtained monogenic representation is compact and a straightforward calculation shows that classical complex representation for plane problems is embedded in the presented extended formulas. Finally the classical uniqueness problem of the Papkovich-Neuber solutions is overcome for polynomial solutions by fixing explicitly linear dependencies. [ABSTRACT FROM AUTHOR]

• High-purity hydrogen production from biogas by means of fixed-bed chemical looping. • Cost-effective, decentralized and scalable system. • 60–78% cold gas efficiency for hydrogen production. • Up to 84% overall system efficiency including heat uncoupling. Decentralized hydrogen production is a promising pathway to use locally available, renewable resources and establish regional value chains. The present work proofs fixed-bed chemical looping (CL) as an efficient and economically favorable option for high-purity hydrogen production from biogas in decentralized systems. In a thermodynamic evaluation, the most important parameters for a high process efficiency and hydrogen purity were identified. The cold gas efficiency (CGE) for hydrogen production from biogas was estimated as 60–78%. An external recirculation was found to increase the CGE by +44% rel. for the predominant Fe–FeO conversion step. Carbon formation in the reduction phase was suppressed at an O/R ratio above 1.2, which is mandatory for high-purity hydrogen production. A pinch analysis proofed the full thermal integration of the process independent of the varied process parameters. The economic feasibility was ascertained based on a case scenario for hydrogen production at a 3 MW th biogas plant. In addition, the impact of various system parameters such as capital costs, oxygen carrier costs and lifetime, and feedstock costs were evaluated. The system efficiency for hydrogen production was estimated at 62.5%, uncoupling the excess heat for district heating increased the overall system efficiency up to 84%. The costs for hydrogen production were estimated at 2.27 € kg H2 −1 in the base scenario, whereby the costs of the hydrogen product including feedstock costs were estimated at 4.6–6.2 € kg H2 −1. The results indicate that fixed-bed chemical looping represents a competitive option for economically sustainable biogas conversion. [ABSTRACT FROM AUTHOR]

The successful application of fixed bed chemical looping hydrogen in industrial scale demands highly stable oxygen carrier pellets. The goal of this work was the realistic long-term characterization of the pelletized oxygen carriers in a fixed bed reactor environment. TGA characterization of an iron-based powder sample containing 5 wt% Al 2 O 3 for 100 cycles showed fast reaction speeds and high oxygen exchange capacity. Characterization of the same sample as pellets in a fixed bed reactor revealed a high temperature gradient, decreased oxygen exchange capacity and a rapid increase in system pressure due to powder formation. The pellet lifetime was prolonged to 100 redox cycles when the material was stored in reduced state at the respective operating temperature. The increased stability of the reduced material could be attributed to the higher crushing strength of the iron and wüstite phase in contrast to magnetite. The increase of the inert portion and of the pellet calcination temperature led to an improved starting material durability but did not influence the mechanical stability after 100 cycles. The results of this study indicate that the long-term redox cycling seems to outweigh the impact of oxygen carrier preparation methods that may be overvalued in the long run. Unlabelled Image • Storing the hot oxygen carrier in reduced condition leads to a longer material life. • High temperature gradients of up to 30 °C min-1 during the oxidation reaction were measured. • After 100 cycles in the fixed bed reactor, a decrease in oxygen exchange capacity and mechanical stability was observed. • Increased inert share or calcination temperature hardens non-cycled pellets but did not improve their redox durability. [ABSTRACT FROM AUTHOR]

Abstract The proof of concept for the production of pure pressurized hydrogen from hydrocarbons in combination with the sequestration of a pure stream of carbon dioxide with the reformer steam iron cycle is presented. The iron oxide based oxygen carrier (95% Fe 2 O 3 , 5% Al 2 O 3) is reduced with syngas and oxidized with steam at 1023 K. The carbon dioxide separation is achieved via partial reduction of the oxygen carrier from Fe 2 O 3 to Fe 3 O 4 yielding thermodynamically to a product gas only containing CO 2 and H 2 O. By the subsequent condensation of steam, pure CO 2 is sequestrated. After each steam oxidation phase, an air oxidation was applied to restore the oxygen carrier to hematite level. Product gas pressures of up to 30.1 bar and hydrogen purities exceeding 99% were achieved via steam oxidations. The main impurities in the product gas are carbon monoxide and carbon dioxide, which originate from solid carbon depositions or from stored carbonaceous molecules inside the pores of the contact mass. The oxygen carrier samples were characterized using elemental analysis, BET surface area measurement, XRD powder diffraction, SEM and light microscopy. The maximum pressure of 95 bar was demonstrated for hydrogen production in the steam oxidation phase after the full oxygen carrier reduction, significantly reducing the energy demand for compressors in mobility applications. Highlights • Proof of concept for carbon capture while high-pressure hydrogen production. • Product gas pressures of up to 30.1 bar in carbon capture mode. • Hydrogen and CO 2 purity exceeding 99%. • 95 bar product gas pressure with full oxygen carrier reduction. [ABSTRACT FROM AUTHOR]

Objective: To modify the Prostate Cancer Prevention Trial risk calculator (PCPTRC) to predict low- vs high-grade (Gleason grade ≥7) prostate cancer and incorporate percent free–prostate-specific antigen (PSA). Methods: Data from 6664 Prostate Cancer Prevention Trial placebo arm biopsies (5826 individuals), where prostate-specific antigen and digital rectal examination results were available within 1 year before the biopsy and PSA was ≤10 ng/mL, were used to develop a nominal logistic regression model to predict the risk of no vs low-grade (Gleason grade <7) vs high-grade cancer (Gleason grade ≥7). Percent free-PSA was incorporated into the model based on likelihood ratio analysis of a San Antonio Biomarkers of Risk cohort. Models were externally validated on 10 Prostate Biopsy Collaborative Group cohorts and 1 Early Detection Research Network reference set. Results: Of all the Prostate Cancer Prevention Trial biopsies, 5468 (82.1%) were negative for prostate cancer, 942 (14.1%) detected low-grade, and 254 (3.8%) detected high-grade disease. Significant predictors were (log base 2) PSA (odds ratio for low-grade vs no cancer, 1.29*; high-grade vs no cancer, 2.02*; high-grade vs low-grade cancer, 1.57*), digital rectal examination (0.96, 1.49*, 1.55*, respectively), age (1.02*, 1.05*, 1.03*, respectively), African American race (1.13, 2.83*, 2.51*, respectively), prior biopsy (0.63*, 0.81, 1.27, respectively), and family history (1.31*, 1.25, 0.95, respectively), where * indicates P value <.05. The new PCPTRC 2.0 either with or without percent free-PSA (also significant by the likelihood ratio method) validated well externally. Conclusion: By differentiating the risk of low- vs high-grade disease on biopsy, PCPTRC 2.0 better enables physician-patient counseling concerning whether to proceed to biopsy. [Copyright &y& Elsevier]

Reliable experimental data and models are required to better understand and design chemical looping processes with oxygen carrier materials like ilmenite. A dubious variability of suggested kinetics for similar oxygen carrier materials has been presented in the literature. Part I of this work focuses on thermogravimetric analysis (TGA) of gas–solid kinetics and addresses several of its challenges, which are possible reasons behind such deviations. The reduction of synthetic ilmenite (60 mass% Fe 2 O 3 ＋ 40 mass% TiO 2) powder with H 2 in a TGA system was investigated for this purpose. Multiple steps were necessary to overcome mass transfer limitations during the measurements: (i) small sample masses down to 1.6 mg, (ii) high gas flow rates, (iii) a suitable sample carrier and (iv) proper sample dispersion on the sample carrier. Three types of sample carriers (crucible, basket and plate) were tested; the plate showed the best performance overall. It was alarming that an exemplary increase in sample mass from 1.6 to 3 mg, which was still significantly lower than all other studies reviewed, already introduced a noticeable influence of diffusion. Isothermal (650–950 ° C , 17–50 vol% H 2) and nonisothermal parameter studies were conducted and yielded vastly different isoconversional activation energies. A computational fluid dynamics (CFD) study of the TGA system suggested considerable axial dispersion of H 2 influencing the initial conversion period. These findings help to assess the reliability of kinetic studies and guide towards diffusion-free, kinetic measurements. The results will be used for model development in part II. • The reduction of synthetic ilmenite with hydrogen was analyzed in a TGA. • Temperature and concentration influences were studied in the kinetic regime. • The questionable variability of results in similar kinetic studies was addressed. • Small increase in mass (1.6 mg to 3 mg) already changed apparent activation energy. • Sample carrier/dispersion, gas flow field and temperature ramps were studied. [ABSTRACT FROM AUTHOR]