Residual Yield Research Articles

Reading between the ratings: Modeling residual credit risk and yield overlap

Abstract Credit ratings group firms by risk, yet yields are shown to overlap between firms of adjacent ratings. We model this by considering the residual risk arising from differences in the parameters of each firm's value process for firms with the same rating. To do so, our framework simultaneously incorporates jump default with Markov-governed likelihoods and continuous defaults in a default-barrier framework. We provide closed-form approximations for expected default time and tail probabilities, and empirically fit the S-shaped yield curve, intra-rating spread, and inter-rating overlap. Results are robust to time period, rating system, sub-rating, and common characteristics such as liquidity.

Information theoretical measures from cumulative and survival densities in quantum systems

AbstractEntropic uncertainty and statistical correlation measures, based on survival and cumulative densities, are explored in some representative quantum systems. We illustrate how the cumulative residual entropy in the quantum well system recovers the correct classical behavior for larger quantum numbers while the Shannon entropy does not. Two interacting and noninteracting oscillators are used to examine two‐particle entropies and their related correlation measures. The joint cumulative residual entropy does distinguish between symmetric and antisymmetric wave functions in interacting systems as the interaction is turned on. The joint Shannon entropy does not distinguish between the symmetries even in the presence of interaction. Conversely, the joint Shannon entropy and joint cumulative residual entropy are both unable to distinguish between the symmetries for certain states of the noninteracting oscillators. As measures of statistical correlation, the mutual information and the cross cumulative residual entropy yield similar behaviors as a function of the strength of the interparticle interaction.

Catalytic pyrolysis of coconut copra and rice husk for possible maximum production of bio-oil

The main objective of the present work is to study the effect of the nickel catalyst on pyrolysis of coconut copra and rice husk via thermo gravimetric analysis (TGA). The optimisation of catalyst weight ratio on biomass is also determined. The sample is pyrolysed from 30 °C up to 700 °C at 10 °C/min of heating rate in nitrogen (N2) environment flowing at 150 mL/min. The catalyst (Ni-Ce/Al2O3) was prepared via wet impregnation method, with alumina (Al2O3) as support, while cerium (Ce) and nickel (Ni) act as promoter. The samples were prepared accordingly with biomass to catalyst weight loading ratio and labelled as follows; rice husk as RH-2 (1 : 0.15) and RH-3 (1 : 0.50) including coconut copra as CC-2 (1 : 0.15) and CC-3 (1 : 0.50). For comparison, the pyrolysis of coconut copra and rice husk without catalyst also are conducted at the same operating condition and named as CC-1 (1 : 0) and RH-1 (1 : 0). The TGA-DTG curves show that, the presences of catalyst significantly affect the devolatilisation rate of biomass. The highest volatile matter was achieved by CC-2 at 83.27 % compared to RH-2 at only 46.66 %. Although at similar biomass to catalyst weight ratio of 1 : 0.15, the coconut copra is more favourable to yield a high volatile matter than the rice husk. At the same time, both biomass samples specifically CC-3 and RH-3 have achieved the highest in solid residual yield. Overall, the mass loss of volatile matter decreases in the order of CC-2 > CC-1 > CC-3 > RH-1 > RH-2 > RH-3. In summary, the optimum catalyst loading was at CC-2 and RH-2 that work best to degrade at the highest mass loss of volatile, in which attributes to higher yield of pyrolysis oil.

Experimental and numerical investigation of the residual yield strength of aluminium alloy EN AW-2024-T3 affected by artificially produced pitting corrosion

In this study, the behaviour of the residual yield strength of aluminium alloy EN AW-2024-T3 affected by the morphology and numbers of corrosion pits (defects) is presented. Since specific defect structures are not reproducible during experimental corrosion tests, metal sheets with different numbers of pits and pit shapes are produced using laser micro structuring. The defect structures are measured using laser scanning microscopy. To compare the stress states of the micro structured and real corroded metal sheets, FE-analysis is used. Afterwards, uniaxial tensile tests are carried out and critical defect parameters in terms of yield strength reduction of the investigated aluminium alloy are detected.

Tailoring Carbon Nanostructure with Diverse and Tunable Morphology by the Pyrolysis of Self-Assembled Lamellar Nanodomains of a Block Copolymer.

The pyrolysis of a block copolymer thin film, the free surface of which was in contact with air or a capping layer of SiO2, produced four carbon nanostructures. Thin films of a diblock copolymer having perpendicularly oriented lamellar nanodomains served as carbon and nitrogen precursors. Before pyrolysis, the lamellar nanodomains were cross-linked with UV irradiation under nitrogen gas (UVIN). Without a capping layer, pyrolysis caused a structural transformation from lamellar nanodomains to short carbon nanowires or to dropletlike nanocarbons in a row via Rayleigh instability, depending on the duration of pyrolysis. When capped with a layer of SiO2 followed by pyrolysis, the lamellar nanodomains were converted to pod-like, spaghetti-like, or long worm-like carbon nanostructures. These carbon nanostructures were driven by controlling the surface or interface tension and the residual yield of solid carbonaceous species.

Synthesis and properties of novel polyimide fibers containing phosphorus groups in the side chain (DATPPO)

A series of polyamic acid copolymers (co-PAAs) containing phosphorous groups in the side chains were synthesized from [2,5-bis(4-aminophenoxy) phenyl] diphenylphosphine oxide (DATPPO) and 4,4′-oxydianiline (ODA) with 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA) through the polycondensation in N,N′-dimethyacetamide (DMAc). The co-PAA solutions were spun into fibers by a dry-jet wet spinning process followed by thermal imidization to obtain co-polyimide (co-PI) fibers. FTIR spectra and elemental analysis confirmed the chemical structure of PI fibers. SEM results indicated that the resulting PI fibers had a smooth and dense surface, a uniform and circle-shape diameter. The thermogravimetric measurements showed that with the increase of DATPPO content, the resulting PI fibers possessed high decomposition temperature and residual char yield, indicating that the PI fibers had good thermal stability. The corresponding limiting oxygen index (LOI) values from the experiment results showed that the co-PI fibers possessed good flame-retardant property. Furthermore, the mechanical properties of the co-PI fibers were investigated systematically. When the DATPPO content increased, the tensile strength and initial modulus of the co-PI fibers decreased. However, the mechanical properties were improved by increasing the draw ratio of the fibers. When the draw ratio was up to 2.5, the tensile strength and initial modulus of the co-PI fibers reached up to 0.64 and 10.02 GPa, respectively. The WAXD results showed that the order degree of amorphous matter increased with increased stretching. In addition, the SAXS results displayed that valuably drawing the fibers could eliminate the voids inside and lead to better mechanical property. WAXD revealed that the orientation of the amorphous polymer influenced the mechanical properties of the fibers.

Impact of Cyclic Loading on Chloride Diffusivity and Mechanical Performance of RC Beams under Seawater Corrosion

An experimental study was conducted to investigate the impact of cyclic loading on the mechanical performance and chloride diffusivity of RC beams exposed to seawater wet-dry cycles. To induce initial damage to RC beam specimen, cyclic loading controlled by max load and cycles was applied. Then beam specimens underwent 240 wet-dry cycles of seawater. Results show that the chloride content increased as max load and cycle increased. The chloride content at steel surface increased approximatively linearly as average crack width increased. Moreover, the max load had more influence on chloride content at steel surface than cycle. The difference of average chloride diffusion coefficient between tension and compression concrete was little at uncracked position. Average chloride diffusion coefficient increased as crack width increased when crack width was less than 0.11 mm whereas the increasing tendency was weak when crack width exceeded 0.11 mm. The residual yield load and ultimate load of RC beams decreased as max load and cycle increased. Based on univariate analysis of variance, the max load had more adverse effect on yield load and ultimate load than cycle.

Expanded polystyrene foams containing ammonium polyphosphate and nano-zirconia with improved flame retardancy and mechanical properties

Expanded polystyrene (EPS) foams were flame retarded using ammonium polyphosphate (APP) and nano-zirconia (nano-ZrO2) by means of phenolic resin as a binder. It is found that the incorporation of a small amount (5 phr) of nano-ZrO2 into the APP flame-retarded EPS foams leads to 19% increase in flexural strength and 38% increase in compressive strength. Flame-retardant properties of the flame-retarded EPS foams were investigated by limiting oxygen index (LOI), UL-94 and cone calorimetry test (CCT). The LOI of the APP flame-retarded EPS foams in presence of nano-ZrO2 is above 31%, and the UL 94 V-0 rating can be reached. The CCT test results indicate that the APP flame-retarded EPS foams containing nano-ZrO2 have lower peak heat release rate, average effective heat of combustion and average specific extinction area. Moreover, thermal decomposition of the flame-retarded EPS foams was investigated by thermogravimetric analysis (TGA) and the TGA results illustrated clearly that the addition of nano-ZrO2 into the APP flame-retarded EPS foams leads to an increase in the residual char yield. The reason for the increase is possibly because ZrO2 may react during combustion process with pyrophosphoric acid produced from the thermal decomposition of APP to form zirconium pyrophosphate (ZrP2O7) confirmed by XRD studies of the char, which is helpful to improve the formation of the char. The XPS results showed that the ratio of oxidized carbons in the char increases with the presence of nano-ZrO2.

Estimation of lateral force contribution of boundary elements in steel plate shear wall systems

SummarySteel plate shear walls (SPSWs) are used as lateral force‐resisting systems in new and retrofitted structures in high‐seismic regions. Various international codes recommend the design of SPSWs assuming the entire lateral load to be resisted by the infill plates. Such a design procedure results in significant overstrength leading to uneconomical and inefficient use of materials. This study is focused on the estimation of contribution of boundary elements in resisting the lateral force considering their interaction with the web plates of SPSW systems. Initially, the relative contribution of web plates and boundary frames is computed for a single‐bay single‐story frame with varying rigidity and end connections of boundary elements. Nonlinear static analyses are carried out for the analytical models in OpenSees platform to quantify this contribution. Later, this study is extended to the code‐based designed three‐story, six‐story, and nine‐story SPSWs of varying aspect ratios. Based on the results obtained, a new design procedure is proposed taking the lateral strengths of the boundary frames into account. Nonlinear time‐history analyses are conducted for 40 recorded ground motions representing the design basis earthquake and maximum considered earthquake hazard levels to compare the interstory and residual drift response and yield mechanisms of SPSWs designed as per current practice and the proposed methodology. Finally, an expression has been proposed to predict the lateral force contribution of the infill plate and the boundary frame of SPSWs. Copyright © 2016 John Wiley & Sons, Ltd.

A model to predict the relaxation of weld residual stress by cyclic load: Experimental and finite element modeling

In this paper, the relaxation of weld residual stress in a 316L stainless steel weld joint under cyclic loading was researched by experimental and finite element method (FEM). Initially, the as-weld residual stresses were calculated by a sequential coupling thermo-mechanical FEM. Subsequently, a cyclic plasticity constitutive model was proposed to study the redistribution of the residual stress by the cyclic load. Significant residual stresses are released during the first few cycles. Especially, about 45–60% of the maximum residual stresses are released during the first cycle because of the plastic deformation caused by the superposition between the as-weld residual stress and the applied load. More residual stresses are released with the increase of the stress amplitude and cyclic number. An analytical model, which considers the effects of the initial residual stress, yield stress, stress amplitude, and number of cycles, was proposed to predict the relaxation of the weld residual stress by the cyclic load. In addition, experimental measurements were also performed to validate this model. Experimental results prove that the proposed model can be used as a valid toolto predict the relaxation of residual stress by the fatigue load.

1683 Genome-wide association analysis of residual feed intake and milk yield in dairy goats

1683 Genome-wide association analysis of residual feed intake and milk yield in dairy goats

A Design of Experiment approach to predict product and process parameters for a spray dried influenza vaccine

Spray dried vaccine formulations might be an alternative to traditional lyophilized vaccines. Compared to lyophilization, spray drying is a fast and cheap process extensively used for drying biologicals. The current study provides an approach that utilizes Design of Experiments for spray drying process to stabilize whole inactivated influenza virus (WIV) vaccine. The approach included systematically screening and optimizing the spray drying process variables, determining the desired process parameters and predicting product quality parameters. The process parameters inlet air temperature, nozzle gas flow rate and feed flow rate and their effect on WIV vaccine powder characteristics such as particle size, residual moisture content (RMC) and powder yield were investigated. Vaccine powders with a broad range of physical characteristics (RMC 1.2–4.9%, particle size 2.4–8.5μm and powder yield 42–82%) were obtained. WIV showed no significant loss in antigenicity as revealed by hemagglutination test. Furthermore, descriptive models generated by DoE software could be used to determine and select (set) spray drying process parameter. This was used to generate a dried WIV powder with predefined (predicted) characteristics. Moreover, the spray dried vaccine powders retained their antigenic stability even after storage for 3 months at 60°C. The approach used here enabled the generation of a thermostable, antigenic WIV vaccine powder with desired physical characteristics that could be potentially used for pulmonary administration.

The pricing of different dimensions of liquidity: Evidence from government guaranteed bonds

Abstract There are three important dimensions of liquidity: trading costs, depth, and resiliency. We investigate the relevance of each of these three dimensions of liquidity – separately and in conjunction – for the pricing of corporate bonds. Unlike previous studies, our sample allows us to cleanly separate the default and non-default components of yield spreads. We find that each of the above three dimensions of liquidity are priced factors. Overall, in our sample, a one standard deviation change in trading costs, resiliency, and depth measures lead to a change in non-default spreads of 5.00 basis points, 2.27 basis points, and 1.27 basis points, respectively. We also find that both bond-specific and market-wide dimensions of liquidity are priced in non-default spreads. Finally, we find that there does exist in some periods a small residual non-default yield spread that is consistent with an additional “flight-to-extreme-liquidity” premium reflecting investor preference for assets that enable quickest possible disengagement from the market when necessary.

Effect of cover crops and nitrogen rates on sprinkler irrigated wheat in low altitude cerrado

RESUMO A produção de trigo no cerrado brasileiro enfrenta grandes desafios, principalmente por não ser a região tradicionalmente tritícola e pela ocorrência de inverno quente e seco. Assim, o objetivo deste trabalho foi avaliar o efeito residual das culturas antecessoras, milho e Urochloa ruziziensis (R. Germ & Evrard), em cultivo exclusivo e em consórcio entre ambas, na presença e ausência da inoculação de sementes com Azospirillum brasilense e adubação nitrogenada (N) em cobertura, no desenvolvimento e na produtividade do trigo. O experimento foi desenvolvido em Selvíria, MS, em 2011/12. O delineamento experimental foi o de blocos ao acaso, disposto em esquema fatorial 8x4, com quatro repetições, cujos tratamentos foram constituídos pela combinação de restos culturais (associações de milho, Urochloa ruziziensis e Azospirillum brasilense) e doses de N (0, 30, 60 e 90 kg ha-1) em cobertura, no trigo. Realizaram-se as seguintes avaliações: cobertura vegetal residual (quantidade), características agronômicas, componentes de produção e produtividade da cultura do trigo. As culturas antecessoras apresentaram efeitos positivos na produtividade do trigo cultivado em sucessão, sendo o consórcio de milho e Urochloa ruziziensis, com ou sem inoculação excelente opção de manejo; o incremento da dose de N, em cobertura, até 90 kg ha- 1 aumenta a produtividade de grãos de trigo irrigado, dependendo da cultura antecessora.

USE OF THE HOLE DRILLING METHOD TO DETERMINE RESIDUAL WELD STRESSES IN BRIDGE CONSTRUCTIONS

Complex welding operations in orthotropic steel bridge decks introduce residual stresses near the weld region. To estimate fatigue failure of this type of bridge deck, tensile residual yield stresses are usually assumed around the weld region. However, to estimate the residual stress distribution near a weld connection more precisely, a test setup is developed. The weld connection of a closed longitudinal trapezoidal stiffener with the deck plate of an orthotropic bridge deck is investigated. The incremental hole-drilling technique is used to measure the residual stresses with strain gauge rosettes. Strain gauge rosettes are positioned on the deck plate and on a longitudinal stiffener of the orthotropic steel deck. A small hole is drilled through the center of the strain gauge rosettes and strains are measured at incremental depths. The residual stresses are calculated and based on these experimental measurements a distribution of the residual stresses is obtained. Compressive residual stresses exist near the longitudinal stiffener-to-deck plate weld. On the deck plate, the compressive residual stresses are equal to 60% of the yield strength while the compressive residual stresses on the stiffener are 42% of the yield strength. There are tensile residual stresses on both sides of the weld region. However, more research is necessary to confirm this distribution since it is contradictory to expected stresses in literature.

Effects on Soil and Crop Properties of Forms of Sowing, Deferral Intervals and Fertilisation of the Annual Winter Forage in a Crop-Livestock Integration System

<p>The use of cropland to grow annual winter forages that are managed using direct grazing can affect the quality of the soil and the yield of summer crops grown in succession. This study aimed to evaluate the effect that the form of sowing (direct sowing and sowing + harrowing), the deferral intervals (ungrazed and grazing stopped at 14 days and 28 days before and on the day of forage desiccation) and the fertilisation of the annual winter forage (with and without application of 8 m<sup>3</sup> ha<sup>-1</sup> of poultry litter) had on the chemical properties of soil, resistance to penetration, residual forage biomass, soil cover and yield of corn and soybean from the third to the sixth year of experimentation. The forms of sowing did not affect the chemical properties of the soil, resistance to penetration, the residual forage biomass and the yield of the soybean and corn grown in rotation. The grazing of annual winter forage did not affect the chemical properties of soil and the yield of soybean and corn grown in succession, but residual forage biomass was reduced and resistance to penetration was increased with decreasing deferral intervals. In turn, the fertilisation of winter forages improved the quality of the chemical properties of the soil and increased the residual forage biomass and crop yields in most of the four years examined in this experiment.</p>

Effect of Post-forging Heat Treatment on Stress Corrosion Cracking of Nuclear Grade 316LN Stainless Steel in Boiling MgCl2 Solution

s: Effect of post solutionand stress relieftreatment on the stress corrosion cracking (SCC) resistance via U-bend specimens test in 42% boiling MgCl2 solution, as well as the microstructure, residual strain and mechanical properties of the forged 316LN stainless steel was studied. Results showed that the yield stress was reduced and the residual strain was eliminated through post solution-treatment for the forged steel. After immersion in boiling MgCl2 solution for 24, 48 and 72 h, respectively, all the U-bend specimens of either the solution-treated or the stress relieftreated steels suffered from clearly transgranular stress corrosion cracking (TGSCC). Furthermore, of which all the stress relief-treated specimens were entirly cracked, while the solution-treated specimens were only locally cracked after immersion for 72 h, suggesting higher SCC resistance for the forged steel after a proper post solution-treatment. Finally, the mechanism of the effect of post-heat 定稿日期:2014-11-05 基金项目:国家科技重大专项项目 (2011ZX06004-009)资助 作者简介:郭跃岭,男,1990年生,硕士生 通讯作者:韩恩厚,E-mail:ehhan@imr.ac.cn,研究方向为苛刻环境中材料的腐蚀与防护 (核电高温高压水、石油化工环境等等) DOI:10.11902/1005.4537.2014.223 6期 郭跃岭等:锻后热处理对核级316LN不锈钢在沸腾MgCl2溶液中应力腐蚀行为的影响 treatments on the SCC resistance was discussed in terms of the residual strain and yield stress of the forged steel.

Studies on Influence of Chemical Modification, Plasticizer and Starch Concentration on Some Characteristics of Biodegradable Film

Starch was isolated from sweet potato and the process was standardized. It was found that the treatment ‘T8’ containing (0.25% potassium meta-bisulphite (KMS) and 0.12% citric acid) had shown excellent and promising result so far as residual protein, yield, past clarity and colour of the isolated starch was concerned. Chemical modification of isolate sweet potato starch at 3% and 5% (w/v) levels was carried out by acetylation using vinyl acetate concentration (4 to 10 %) and dual-modification using propylene oxide at a specific level of 7% and adipic acid anhydride (0.05 to 0.12%). Biodegradable films were prepared from the isolated native and modified starches. Glycerol at levels such as (0.25g/g, 0.35g/g, and 0.45g/g) was used as a plasticizer in the film preparation. Thickness of bio-films increased with increase in glycerol and starch concentrations whereas solubility decreased with increase in starch concentration and modification levels. Water and acid solubility of films prepared from native starch were highest which decreased in the acetylated starch films and further decreased in cross-linked starch films. With increase in starch and glycerol concentration tensile and puncture strengths of bio-films increased. Dual-modified starch films had shown higher mechanical strength than acetylated starches. The biodegradability was higher for native bio-films followed by acetylated starch and least for dual-modified films.

Geostatistical Analyses of Field Spatial Variability of Cotton Yield

More information is needed on the spatial variability of soil properties and plant characteristics at the field strip plot experiment scale for accurate evaluation of treatment effect significance. The objective of this study was to examine the pattern and degree of field spatial variability of cotton yield and the relationship between cotton yield and canopy Normalized Difference Vegetation Index (NDVI). A strip plot trial was carried out on a private farm near Brazil, Gibson County, TN from 2009 to 2011. Five side dress N treatments of 0, 45, 90, 134, and 179 kg N ha-1 were imposed on cotton in strip plots under a RCB design with three replications after 45 kg N ha-1 was applied as pre-plant N in the form of chicken litter. Spatial variability was high in lint yield although its pattern and degree varied with year. The correlation of lint yield with NDVI was almost always statistically significant but not strong during early square to late bloom irrespective of year. There was significant global spatial autocorrelation of residual lint yield (N treatment effects on yield excluded) within the test field in 2010 and 2011 based on the Moran’s I statistic. The Localized Indicators of Spatial Autocorrelation (LISA) cluster map showed that there were some significant local clusters of residual lint yield within the field each year. In conclusion, spatial variability needs to be included in data analyses of N treatment effects on cotton yield in strip plot field studies. Cotton yield from farmers’ fields could be expected to have noticeable annual and within field spatial variations in the region, which will significantly influence cotton yields.

The preparation and properties study of polydimethylsiloxane-based coatings modified by epoxy resin

In this research, a hydroxyl-terminated polydimethylsiloxane (HTPDMS) was modified by the incorporation of siliconized epoxy resin (SER) containing a segment of siloxane on the side chain of epoxy resin. The chemical structure of the SER was studied by FT-IR, GPC and NMR techniques. Adhesion test showed that the adhesion strength of silicone rubber systems improved markedly after modification. Contact angle (CA) measurements showed the presence of the epoxy block at the surface, which improved adhesion properties of the modified HTPDMS. Morphology studies (SEM) displayed that enhancement in the mechanical properties of the silicone rubber systems due to good compatibility between SER and silicone rubber matrix. Thermogravimetric analysis (TGA) indicated that the residual yield at 800 °C of modified HTPDMS increased compared with that of the neat HTPDMS, but the onset decomposition temperature was reduced with the increase in SER content. These observations highlight the significant role of SER in the modification of HTPDMS.