Application of a Pore Fraction Hot Tearing Model to Directionally Solidified and Direct Chill Cast Aluminum Alloys

NASA Astrophysics Data System (ADS)

Dou, Ruifeng; Phillion, A. B.

2016-08-01

Hot tearing susceptibility is commonly assessed using a pressure drop equation in the mushy zone that includes the effects of both tensile deformation perpendicular to the thermal gradient as well as shrinkage feeding. In this study, a Pore Fraction hot tearing model, recently developed by Monroe and Beckermann (JOM 66:1439-1445, 2014), is extended to additionally include the effect of strain rate parallel to the thermal gradient. The deformation and shrinkage pore fractions are obtained on the basis of the dimensionless Niyama criterion and a scaling variable method. First, the model is applied to the binary Al-Cu system under conditions of directional solidification. It is shown that for the same Niyama criterion, a decrease in the cooling rate increases both the deformation and shrinkage pore fractions because of an increase in the time spent in the brittle temperature region. Second, the model is applied to the industrial aluminum alloy AA5182 as part of a finite element simulation of the Direct Chill (DC) casting process. It is shown that an increase in the casting speed during DC casting increases the deformation and shrinkage pore fractions, causing the maximum point of pore fraction to move towards the base of the casting. These results demonstrate that including the strain rate parallel to the thermal gradient significantly improves the predictive quality of hot tearing criteria based on the pressure drop equation.

A mathematical model of the heat and fluid flows in direct-chill casting of aluminum sheet ingots and billets

NASA Astrophysics Data System (ADS)

Mortensen, Dag

1999-02-01

A finite-element method model for the time-dependent heat and fluid flows that develop during direct-chill (DC) semicontinuous casting of aluminium ingots is presented. Thermal convection and turbulence are included in the model formulation and, in the mushy zone, the momentum equations are modified with a Darcy-type source term dependent on the liquid fraction. The boundary conditions involve calculations of the air gap along the mold wall as well as the heat transfer to the falling water film with forced convection, nucleate boiling, and film boiling. The mold wall and the starting block are included in the computational domain. In the start-up period of the casting, the ingot domain expands over the starting-block level. The numerical method applies a fractional-step method for the dynamic Navier-Stokes equations and the “streamline upwind Petrov-Galerkin” (SUPG) method for mixed diffusion and convection in the momentum and energy equations. The modeling of the start-up period of the casting is demonstrated and compared to temperature measurements in an AA1050 200×600 mm sheet ingot.

Iron rich low cost superalloys. Ph.D. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Wayne, S. F.

1985-01-01

An iron-rich low-cost superalloy was developed. The alloy, when processed by conventional chill casting, has physical and mechanical properties that compare favorably with existing nickel and cobalt based superalloys while containing significantly lower amounts of strategic elements. Studies were also made on the properties of Cr(20)-Mn(10)-C(3.4)-Fe(bal.), a eutectic alloy processed by chill casting and directional solidification which produced an aligned microstructure consisting of M7C3 fibers in a gamma-Fe matrix. Thermal expansion of the M7C3 (M = Fe, Cr, Mn) carbide lattice was measured up to 800 C and found to be highly anisotropic, with the a-axis being the predominant mode of expansion. Repetitive impact sliding wear experiments performed with the Fe rich eutectic alloy showed that the directionally solidified microstructure greatly improved the alloy's wear resistance as compared to the chill cast microstructure and conventional nickel base superalloys. Studies on the molybdenum cementite phase prove that the crystal structure of the xi phase is not orthorhombic. The crystal structure of the xi phase is made up of octahedra building elements consisting of four Mo and two Fe atoms and trigonal prisms consisting of four Fe and two Mo atoms. The voids are occupied by carbon atoms. The previous chemical formula for the molybdenum cementite MoFe2C is now clearly seen to be Mo12Fe22C10.

A new magnesium alloy system: TEXAS

NASA Astrophysics Data System (ADS)

Wiese, Björn; Mendis, Chamini; Blawert, Carsten; Nyberg, Eric; Kainer, Karl Ulrich; Hort, Norbert

A new TEXAS alloy system (Mg-Sn-Nd-Ca-Al-Si) is presented in order to extend the range of applications for magnesium alloys. The alloy has been produced by permanent mould direct chill casting, a process that provides a homogenous distribution of alloying elements throughout the entire casting. This work presents microstructural features and a new Mg-Sn-Ca phase with the morphology of hexagonal platelets. Additionally mechanical properties and the corrosion behaviour of TEXAS alloys are presented in as cast and heat treated conditions.

Modeling of the Coupling of Microstructure and Macrosegregation in a Direct Chill Cast Al-Cu Billet

NASA Astrophysics Data System (ADS)

Heyvaert, Laurent; Bedel, Marie; Založnik, Miha; Combeau, Hervé

2017-10-01

The macroscopic multiphase flow and the growth of the solidification microstructures in the mushy zone of a direct chill (DC) casting are closely coupled. These couplings are the key to the understanding of the formation of the macrosegregation and of the non-uniform microstructure of the casting. In the present paper we use a multiphase and multiscale model to provide a fully coupled picture of the links between macrosegregation and microstructure in a DC cast billet. The model describes nucleation from inoculant particles and growth of dendritic and globular equiaxed crystal grains, fully coupled with macroscopic transport phenomena: fluid flow induced by natural convection and solidification shrinkage, heat, mass, and solute mass transport, motion of free-floating equiaxed grains, and of grain refiner particles. We compare our simulations to experiments on grain-refined and non-grain-refined industrial size billets from literature. We show that a transition between dendritic and globular grain morphology triggered by the grain refinement is the key to the explanation of the differences between the macrosegregation patterns in the two billets. We further show that the grain size and morphology are strongly affected by the macroscopic transport of free-floating equiaxed grains and of grain refiner particles.

Surface Structure Formation in Direct Chill (DC) Casting of Al Alloys

NASA Astrophysics Data System (ADS)

Bayat, Nazlin; Carlberg, Torbjörn

2014-05-01

The aim of this study is to increase the understanding of the surface zone formation during direct chill (DC) casting of aluminum billets produced by the air slip technology. The depth of the shell zone, with compositions deviating from the bulk, is of large importance for the subsequent extrusion productivity and quality of final products. The surface microstructures of 6060 and 6005 aluminum alloys in three different surface appearances—defect free, wavy surface, and spot defects—were studied. The surface microstructures and outer appearance, segregation depth, and phase formation were investigated for the mentioned cases. The results were discussed and explained based on the exudation of liquid metal through the mushy zone and the fact that the exudated liquid is contained within a surface oxide skin. Outward solidification in the surface layer was quantitatively analyzed, and the oxide skin movements explained meniscus line formation. Phases forming at different positions in the segregation zone were analyzed and coupled to a cellular solidification in the exudated layer.

40 CFR 467.33 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

.../million off-lbs) of aluminum extruded Chromium 0.15 0.061 Cyanide 0.098 0.041 Zinc 0.49 0.21 Aluminum 2.19... Chromium 0.65 0.27 Cyanide 0.43 0.18 Zinc 2.16 0.90 Aluminum 9.51 4.73 Subpart C Direct Chill Casting... Maximum for monthly average mg/off-kg (lb/million off-lbs) of aluminum cast Chromium 0.59 0.24 Cyanide 0...

Cause and Prevention of Explosions Involving DC Casting of Aluminum Sheet Ingot

NASA Astrophysics Data System (ADS)

Richter, Ray T.; Ekenes, J. Martin

The casting of aluminum alloy sheet ingot and T-bar presents the potential for some of the most volatile situations that can occur in DC (direct chill) and EMC (Electromagnetic) casting processes. Aluminum Association explosion incident data from over 300 explosions spanning a twenty-year period were reviewed and analyzed looking for common factors and repetitive reasons for explosions. Analysis of explosions occurring during the three stages of sheet ingot casting, `start of cast', `steady state' and `end of cast', were examined and prioritized. Case studies illustrate the need for understanding both technical and non-technical factors contributing to explosions involving molten metal. This paper identifies the major causes of explosions involving DC casting of aluminum alloy sheet ingot and makes recommendations for how to prevent the recurrence of such events and minimize the risk of injury.

Effects of aluminum and copper chill on mechanical properties and microstructures of Cu-Zn-Al alloys with sand casting

NASA Astrophysics Data System (ADS)

Ardhyananta, Hosta; Wibisono, Alvian Toto; Ramadhani, Mavindra; Widyastuti, Farid, Muhammad; Gumilang, Muhammad Shena

2018-04-01

Cu-Zn-Al alloy is one type of brass, which has high strength and high corrosion resistant. It has been applied on ship propellers and marine equipment. In this research, the addition of aluminum (Al) with variation of 1, 2, 3, 4% aluminum to know the effect on mechanical properties and micro structure at casting process using a copper chill and without copper chill. This alloy is melted using furnace in 1100°C without holding. Then, the molten metal is poured into the mold with copper chill and without copper chill. The speciment of Cu-Zn-Al alloy were chracterized by using Optical Emission Spectroscopy (OES), Metallography Test, X-Ray Diffraction (XRD), Hardness Test of Rockwell B and Charpy Impact Test. The result is the addition of aluminum and the use of copper chill on the molds can reduce the grain size, increases the value of hardness and impact.

Precipitation of Al3(Sc,Zr) Particles in a Direct Chill Cast Al-Zn-Mg-Cu-Sc-Zr Alloy During Conventional Solution Heat Treatment and its Effect on Tensile Properties

DTIC Science & Technology

2007-12-01

recrystallization during hot working and introduce additional strengthening through the formation of fine coherent Al3(Sc,Zr) particles from a super...microstructure was described in detail elsewhere [8]. TEM analysis of the as-cast alloy revealed large eutectic -forming particles, which were enriched...however suggest that this additional strengthening (~10-30 MPa) can be due to incomplete dissolution of the eutectic phases, which were present in the

Effect of Grain Refining on Defect Formation in DC Cast Al-Zn-Mg-Cu Alloy Billet

NASA Astrophysics Data System (ADS)

Nadella, Ravi; Eskin, Dmitry; Katgerman, Laurens

In direct chill (DC) casting, the effect of grain refining on the prominent defects such as hot cracking and macrosegregation remains poorly understood, especially for multi-component commercial aluminum alloys. In this work, DC casting experiments were conducted on a 7075 alloy with and without grain refining at two casting speeds. The grain refiner was introduced either in the launder or in the furnace. The concentration profiles of Zn, Cu and Mg, measured along the billet diameter, showed that the increasing casting speed raises the segregation levels but grain refining does not seem to have a noticeable effect. However, hot cracking tendency is significantly reduced with grain refining and it is observed that crack is terminated with the introduction of grain refiner at a lower casting speed. These experimental results are correlated with microstructural observations such as grain size and morphology, and the occurrence of floating grains.

Development of the Electromagnetic Continuous Casting Technology for of Magnesium Alloys

NASA Astrophysics Data System (ADS)

Park, Joon-Pyo; Kim, Myoung-Gyun; Kim, Jong-Ho; Lee, Gyu-Chang

Currently, magnesium billets produced by ingot casting or direct chill casting process, result in low-quality surfaces and low productivity, Continuous casting technology to solve these problem has not only high-quality surface billets with fine-grained and homogeneous microstructure but also cost down. The latent heat of fusion per weight (J/g) of magnesium is similar to other metals, however, considering the heat emitted to the mold surface during continuous casting in meniscus region and converting it to the latent heat of fusion per volume, magnesium will be rapidly solidified in the mold during continuous casting, which induces subsequent surface defect formation. In this study, electromagnetic casting and stirring (EMC and EMS) techniques are proposed to control solidification process conveniently by compensating the low latent heat of solidification by volume and to fabricate magnesium billet with high-quality surface. This technique was extended to large scale billets up to 300 mm diameter and continuous casting was successfully conducted. Then magnesium billet was used for the fabrication of prototype automobile pulley.

Melt Conditioning of Light Metals by Application of High Shear for Improved Microstructure and Defect Control

NASA Astrophysics Data System (ADS)

Patel, Jayesh B.; Yang, Xinliang; Mendis, Chamini L.; Fan, Zhongyun

2017-04-01

Casting is the first step toward the production of majority of metal products whether the final processing step is casting or other thermomechanical processes such as extrusion or forging. The high shear melt conditioning provides an easily adopted pathway to producing castings with a more uniform fine-grained microstructure along with a more uniform distribution of the chemical composition leading to fewer defects as a result of reduced shrinkage porosities and the presence of large oxide films through the microstructure. The effectiveness of high shear melt conditioning in improving the microstructure of processes used in industry illustrates the versatility of the high shear melt conditioning technology. The application of high shear process to direct chill and twin roll casting process is demonstrated with examples from magnesium melts.

Effects of MC-Type Carbide Forming and Graphitizing Elements on Thermal Fatigue Behavior of Indefinite Chilled Cast Iron Rolls

NASA Astrophysics Data System (ADS)

Ahiale, Godwin Kwame; Choi, Won-Doo; Suh, Yongchan; Lee, Young-Kook; Oh, Yong-Jun

2015-11-01

The thermal fatigue behavior of indefinite chilled cast iron rolls with various V+Nb contents and Si/Cr ratios was evaluated. Increasing the ratio of Si/Cr prolonged the life of the rolls by reducing brittle cementites. Higher V+Nb addition also increased the life through the formation of carbides that refined and toughened the martensite matrix and reduced the thermal expansion mismatch in the microstructure.

Effects of Process Parameters on Solidification Structure of A390 Aluminum Alloy Hollow Billet

NASA Astrophysics Data System (ADS)

Zuo, Kesheng; Zhang, Haitao; Qin, Ke; Cui, Jianzhong; Chen, Qingzhang

2017-08-01

The effects of process parameters on the solidification structure of A390 aluminum alloy hollow billets prepared by direct-chill casting were investigated. The decrease of casting temperature deteriorated the homogeneity and increased the size of primary Si particles in the hollow billet. Although the average size of primary Si particles was not obviously affected by the increase of casting speed, the thickness of Si-depleted layer at the inner wall increased with the higher casting speed. The tensile strength of A390 alloy is a function of the percentage of coarse Si particles (larger than 35 μm) and the average size of primary Si particles. Higher and more stable tensile strength can be received in the hollow billet with the casting temperature of 1050 K (777 °C), because the fine and uniformly distributed primary Si particles were obtained in the hollow billet.

Segregation and microstructure evolution in chill cast and directionally solidified Ni-Mn-Sn metamagnetic shape memory alloys

NASA Astrophysics Data System (ADS)

Czaja, P.; Wierzbicka-Miernik, A.; Rogal, Ł.

2018-06-01

A multiphase solidification behaviour is confirmed for a range of Ni-rich and Ni-deficient Ni-Mn-Sn induction cast and directionally solidified (Bridgman) alloys. The composition variation is primarily linked to the changing Mn/Sn ratio, whereas the content of Ni remains largely stable. The partitioning coefficients for the Ni50Mn37Sn13 and Ni46Mn41.5Sn12.5 Bridgman alloys were obtained according to the Scheil equation based on the composition distribution along the longitudinal cross section of the ingots. Homogenization heat treatment performed for 72 h at 1220 K turned out sufficient for ensuring chemical uniformity on the macro- and microscale. It is owed to a limited segregation length scale due to slow cooling rates adopted for the directional solidification process.

Predictive Capabilities of Multiphysics and Multiscale Models in Modeling Solidification of Steel Ingots and DC Casting of Aluminum

NASA Astrophysics Data System (ADS)

Combeau, Hervé; Založnik, Miha; Bedel, Marie

2016-08-01

Prediction of solidification defects, such as macrosegregation and inhomogeneous microstructures, constitutes a key issue for industry. The development of models of casting processes needs to account for several imbricated length scales and different physical phenomena. For example, the kinetics of the growth of microstructures needs to be coupled with the multiphase flow at the process scale. We introduce such a state-of-the-art model and outline its principles. We present the most recent applications of the model to casting of a heavy steel ingot and to direct chill casting of a large Al alloy sheet ingot. Their ability to help in the understanding of complex phenomena, such as the competition between nucleation and growth of grains in the presence of convection of the liquid and of grain motion is shown, and its predictive capabilities are discussed. Key issues for future developments and research are addressed.

Process-scale modelling of microstructure in direct chill casting of aluminium alloys

NASA Astrophysics Data System (ADS)

Bedel, M.; Heyvaert, L.; Založnik, M.; Combeau, H.; Daloz, D.; Lesoult, G.

2015-06-01

The mechanical properties of an alloy being related to its microstructure, the understanding of the mechanisms responsible for the grain structure formation in direct chill casting is crucial. However, the grain size prediction by modelling is difficult since a variety of multi-scale coupled phenomena have to be considered. Nucleation and growth of the grains are interrelated, and the macroscopic transport phenomena such as the motion of grains and inoculant particles with the flow impact the nucleation-gowth competition. Thus we propose to study the grain size distribution of a 5182 alloy industrial scale slab of 510 mm thickness, both non-inoculated and inoculated with Al-3Ti-1B, for which experimental grain size measurements are available. We use a volume-averaged two-phase multi-scale model that describes nucleation from inoculant particles and grain growth, fully coupled with macroscopic transport phenomena: fluid flow induced by natural convection and solidification shrinkage, heat, mass and solute mass transport, grains and inoculant particles motion. We analyze the effect of liquid and grain motion as the effect of grain morphology on microstructure formation and we show in which extent those phenomena are responsible for the grain size distribution observed experimentally. The effect of the refiner level is also studied.

40 CFR 471.44 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... chill casting contact cooling water. Subpart D—PSES Pollutant or pollutant property Maximum for any one...) Shot casting contact cooling water. Subpart D—PSES Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of precious metals shot cast...

40 CFR 471.44 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... chill casting contact cooling water. Subpart D—PSES Pollutant or pollutant property Maximum for any one...) Shot casting contact cooling water. Subpart D—PSES Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of precious metals shot cast...

40 CFR 471.44 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2011 CFR

2011-07-01

... chill casting contact cooling water. Subpart D—PSES Pollutant or pollutant property Maximum for any one...) Shot casting contact cooling water. Subpart D—PSES Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of precious metals shot cast...

40 CFR 471.44 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

... chill casting contact cooling water. Subpart D—PSES Pollutant or pollutant property Maximum for any one...) Shot casting contact cooling water. Subpart D—PSES Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of precious metals shot cast...

40 CFR 471.44 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2012 CFR

2012-07-01

... chill casting contact cooling water. Subpart D—PSES Pollutant or pollutant property Maximum for any one...) Shot casting contact cooling water. Subpart D—PSES Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/off-kg (pounds per million off-pounds) of precious metals shot cast...

The Effects of Fracture Origin Size on Fatigue Properties of Ductile Cast Iron with Small Chill Structures

NASA Astrophysics Data System (ADS)

Sameshima, Daigo; Nakamura, Takashi; Horikawa, Noritaka; Oguma, Hiroyuki; Endo, Takeshi

Reducing the weight of a machine structure is an increasingly important consideration both for the conservation of resources during production and for the energy saving during operation. With these objectives in mind, thin-walled ductile cast iron has recently been developed. Because rapid cooling could result in brittle microstructure of cementite (chill) in this cast iron, it is necessary to investigate the effect of cementite on the fatigue properties. Therefore, fatigue tests were carried out on a ductile cast iron of block castings which contained a relatively small amount of cementite. Fracture surface observation indicated that the fracture origins were located at graphite clusters and cast shrinkage porosity, not at cementite. It appears that when the size of the cementite is smaller than that of the graphite, the cementite does not affect the fatigue properties of ductile cast iron. Not surprisingly, the fatigue lives were found to increase with decrease in the size of the fatigue fracture origin. The threshold initial stress intensity factor range ΔKini,th for fatigue failure was found to be about 3-4MPa√m, independent of microstructure.

40 CFR 471.21 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... mg/off-kg (pounds per million off-pounds) of forged magnesium cooled with water Chromium 1.27 0.520... million off-pounds) of magnesium forged Chromium 0.018 0.007 Zinc 0.059 0.025 Ammonia 5.32 2.34 Fluoride 2... cast with direct chill methods Chromium 1.74 0.711 Zinc 5.77 2.41 Ammonia 527 232 Fluoride 235 105 Oil...

A multiphysics and multiscale model for low frequency electromagnetic direct-chill casting

NASA Astrophysics Data System (ADS)

Košnik, N.; Guštin, A. Z.; Mavrič, B.; Šarler, B.

2016-03-01

Simulation and control of macrosegregation, deformation and grain size in low frequency electromagnetic (EM) direct-chill casting (LFEMC) is important for downstream processing. Respectively, a multiphysics and multiscale model is developed for solution of Lorentz force, temperature, velocity, concentration, deformation and grain structure of LFEMC processed aluminum alloys, with focus on axisymmetric billets. The mixture equations with lever rule, linearized phase diagram, and stationary thermoelastic solid phase are assumed, together with EM induction equation for the field imposed by the coil. Explicit diffuse approximate meshless solution procedure [1] is used for solving the EM field, and the explicit local radial basis function collocation method [2] is used for solving the coupled transport phenomena and thermomechanics fields. Pressure-velocity coupling is performed by the fractional step method [3]. The point automata method with modified KGT model is used to estimate the grain structure [4] in a post-processing mode. Thermal, mechanical, EM and grain structure outcomes of the model are demonstrated. A systematic study of the complicated influences of the process parameters can be investigated by the model, including intensity and frequency of the electromagnetic field. The meshless solution framework, with the implemented simplest physical models, will be further extended by including more sophisticated microsegregation and grain structure models, as well as a more realistic solid and solid-liquid phase rheology.

Constitutive behavior of as-cast AA1050, AA3104, and AA5182

NASA Astrophysics Data System (ADS)

van Haaften, W. M.; Magnin, B.; Kool, W. H.; Katgerman, L.

2002-07-01

Recent thermomechanical modeling to calculate the stress field in industrially direct-chill (DC) cast-aluminum slabs has been successful, but lack of material data limits the accuracy of these calculations. Therefore, the constitutive behavior of three aluminum alloys (AA1050, AA3104, and AA5182) was determined in the as-cast condition using tensile tests at low strain rates and from room temperature to solidus temperature. The parameters of two constitutive equations, the extended Ludwik equation and a combination of the Sellars-Tegart equation with a hardening law, were determined. In order to study the effect of recovery, the constitutive behavior after prestraining at higher temperatures was also investigated. To evaluate the quantified constitutive equations, tensile tests were performed simulating the deformation and cooling history experienced by the material during casting. It is concluded that both constitutive equations perform well, but the combined hardening-Sellars-Tegart (HST) equation has temperature-independent parameters, which makes it easier to implement in a DC casting model. Further, the deformation history of the ingot should be taken into account for accurate stress calculations.

CENTRIFUGAL CASTING MACHINE

DOEpatents

Shuck, A.B.

1958-04-01

A device is described that is specifically designed to cast uraniumn fuel rods in a vacuunn, in order to obtain flawless, nonoxidized castings which subsequently require a maximum of machining or wastage of the expensive processed material. A chamber surrounded with heating elements is connected to the molds, and the entire apparatus is housed in an airtight container. A charge of uranium is placed in the chamber, heated, then is allowed to flow into the molds While being rotated. Water circulating through passages in the molds chills the casting to form a fine grained fuel rod in nearly finished form.

A Simplified Three-Phase Model of Equiaxed Solidification for the Prediction of Microstructure and Macrosegregation in Castings

NASA Astrophysics Data System (ADS)

Tveito, Knut Omdal; Pakanati, Akash; M'Hamdi, Mohammed; Combeau, Hervé; Založnik, Miha

2018-04-01

Macrosegregation is a result of the interplay of various transport mechanisms, including natural convection, solidification shrinkage, and grain motion. Experimental observations also indicate the impact of grain morphology, ranging from dendritic to globular, on macrosegregation formation. To avoid the complexity arising due to modeling of an equiaxed dendritic grain, we present the development of a simplified three-phase, multiscale equiaxed dendritic solidification model based on the volume-averaging method, which accounts for the above-mentioned transport phenomena. The validity of the model is assessed by comparing it with the full three-phase model without simplifications. It is then applied to qualitatively analyze the impact of grain morphology on macrosegregation formation in an industrial scale direct chill cast aluminum alloy ingot.

Study of twin-roll cast Aluminium alloys subjected to severe plastic deformation by equal channel angular pressing

NASA Astrophysics Data System (ADS)

Poková, M.; Cieslar, M.

2014-08-01

Aluminium alloys prepared by twin-roll casting method become widely used in industry applications. Their high solid solution supersaturation and finer grains ensure better mechanical properties when compared with the direct-chill cast ones. One of the possibilities how to enhance their thermal stability is the addition of zirconium. After heat treatment Al3Zr precipitates form and these pin moving grain boundaries when the material is exposed to higher temperatures. In the present work twin-roll cast aluminium alloys based on AA3003 with and without Zr addition were annealed for 8 hours at 450 °C to enable precipitation of Al3Zr phase. Afterwards they were subjected to severe plastic deformation by equal channel angular pressing, which led to the reduction of average grain size under 1 μm. During subsequent isochronal annealing recovery and recrystallization took place. These processes were monitored by microhardness measurements, light optical microscopy and in-situ transmission electron microscopy. The addition of Zr stabilizes the grain size and increases the recrystallization temperature by 100 °C.

Effect of iron-intermetallics and porosity on tensile and impact properties of aluminum-silicon-copper and aluminum-silicon-magnesium cast alloys

NASA Astrophysics Data System (ADS)

Ma, Zheyuan

Aluminum-silicon (Al-Si) alloys are an important class of materials that constitute the majority of aluminum cast parts produced, due to their superior properties and excellent casting characteristics. Within this family of alloys, Al-Si-Cu and Al-Si-Mg cast alloys are frequently employed in automotive applications. The commercially popular 319 and 356 alloys, representing these two alloy systems, were selected for study in the present work, with the aim of investigating the effect of iron intermetallics and porosity on the alloy performance. This was carried out through a study of the tensile and impact properties, these being two of the important mechanical properties used in design calculations. Iron, through the precipitation of second phase intermetallic constituents, in particular the platelike beta-Al5FeSi phase, is harmful to the alloy properties. Likewise, gas- or shrinkage porosity in castings is also detrimental to the mechanical properties. By determining the optimum alloying, melt processing and solidification parameters (viz., Fe content, Sr modification and cooling rate) required to minimize the harmful effects of porosity and iron intermetallics, and studying their role on the fracture behavior, the fracture mechanism in the alloys could be determined. Castings were prepared from both industrial and experimental 319.2, B319.2 and A356.2 alloy melts, containing Fe levels of 0.2--1.0 wt%. Sr-modified (˜200 ppm) melts were also prepared for each alloy Fe level. The end-chilled refractory mold used provided directional solidification and a range of cooling rates (or dendrite arm spacings, DAS) within the same casting. Tensile and impact test samples machined from specimen blanks sectioned from the castings at various heights above the chill end provided DASs of 23--85mum. All samples were T6-heat-treated before testing. Tests were carried out employing Instron Universal and Instrumented Charpy testing machines. Optical microscopy, image analysis, SEM and EPMA techniques were used for microstructural and fracture analysis. The results show that the highest cooling rate (23 mum DAS) is the most significant parameter controlling the size and distribution of the beta-Al 5FeSi phase and porosity in the unmodified 319.2 and A356.2 alloys. (Abstract shortened by UMI.)

Porosity and environment

NASA Technical Reports Server (NTRS)

Piwonka, T. S.

1984-01-01

Significant progress was achieved when it was realized that porosity could be analyzed successfully by considering not only heat flow, but also fluid flow within the solidifying casting. Sound castings may be produced by lowering pressure during melting (to allow dissolved gas to escape the melt) and increasing pressure during solidification (to force liquid metal into the mushy zone to feed shrinkage). Such techniques are especially effective if they are combined with chilling of parts of the casting to produce progressive solidification, which shortens the mushy zone and, hence, the distance that metal must travel to feed porosity.

Filler metal alloy for welding cast nickel aluminide alloys

DOEpatents

Santella, M.L.; Sikka, V.K.

1998-03-10

A filler metal alloy used as a filler for welding cast nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and cast in copper chill molds. 3 figs.

Hot tearing studies in AA5182

NASA Astrophysics Data System (ADS)

van Haaften, W. M.; Kool, W. H.; Katgerman, L.

2002-10-01

One of the major problems during direct chill (DC) casting is hot tearing. These tears initiate during solidification of the alloy and may run through the entire ingot. To study the hot tearing mechanism, tensile tests were carried out in semisolid state and at low strain rates, and crack propagation was studied in situ by scanning electron microscopy (SEM). These experimentally induced cracks were compared with hot tears developed in an AA5182 ingot during a casting trial in an industrial research facility. Similarities in the microstructure of the tensile test specimens and the hot tears indicate that hot tearing can be simulated by performing tensile tests at semisolid temperatures. The experimental data were compared with existing hot tearing models and it was concluded that the latter are restricted to relatively high liquid fractions because they do not take into account the existence of solid bridges in the crack.

The Coupling of Macrosegregation with Grain Nucleation, Growth and Motion in DC Cast Aluminum Alloy Ingots

NASA Astrophysics Data System (ADS)

Založnik, Miha; Kumar, Arvind; Combeau, Hervé; Bedel, Marie; Jarry, Philippe; Waz, Emmanuel

The phenomena responsible for the formation of macrosegregations, and grain structures during solidification are closely intertwined. We present a model study of the formation of macrosegregation and grain structure in an industrial sized (350 mm thick) direct chill (DC) cast aluminum alloy slab. The modeling of these phenomena in DC casting is a challenging problem mainly due to the size of the products, the variety of the phenomena to be accounted for, and the non-linearities involved. We used a volume-averaged multiscale model that describes nucleation on grain refiner particles and grain growth, coupled with macroscopic transport: fluid flow driven by natural convection and shrinkage, transport of free-floating globular equiaxed grains, heat transfer, and solute transport. We analyze the heat and mass transfer in the slurry moving-grain zone that is a result of the coupling of the fluid flow and of the grain nucleation, growth and motion. We discuss the impact of the flow structure in the slurry zone and of the grain packing fraction on the macrosegregation.

Strip casting with fluxing agent applied to casting roll

DOEpatents

Williams, R.S.; O`Malley, R.J.; Sussman, R.C.

1997-07-29

A strip caster for producing a continuous strip includes a tundish for containing a melt, a pair of horizontally disposed water cooled casting rolls and devices for electrostatically coating the outer peripheral chill surfaces of the casting rolls with a powder flux material. The casting rolls are juxtaposed relative to one another for forming a pouting basin for receiving the melt through a teeming tube thereby establishing a meniscus between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line to a sealing chamber. A preferred flux is boron oxide having a melting point of about 550 C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll. 3 figs.

Wrinkling Phenomena to Explain Vertical Fold Defects in DC-Cast Al-Mg4.5

NASA Astrophysics Data System (ADS)

Davis, J. Lee; Mendez, Patricio F.

Some aluminum ingots cast by the direct chill method are subject to surface defects on the molten ingot head during casting while others are not. These defects -commonly called "vertical folds" -are frozen into the casting and must be removed prior to rolling. Vertical folds are found on top of the molten ingot surface where areas of thin oxide are (a) bounded by physical constraints and (b) stretched. Physical constraints include (1) substantially thicker oxide or (2) a refractory skim ring adjacent to the thin oxide. The mechanism of wrinkling is suggested for the formation of vertical folds. Wrinkling behavior is described by physical expressions for an elastic sheet in tension whose behavior depends upon thickness h, length L, Young's modulus E, and Poisson's ratio v. The depth and frequency of folds in the thin, elastic sheet parallel to the tensile axis between the two "constraints" can be calculated from these parameters. The observed frequency (and amplitude) of vertical folds in DC-cast aluminum has been found to obey similar wrinkling laws. The frequency-dependence (λ) is examined and found to be related to classic wrinkling parameters but with significant scaling deviations. These deviations may be related to the pseudo-plasticity (self-healing behavior) of the oxide film on the molten surface. A wrinkling model coupled with pseudo-plasticity predicts subtle behaviors in DC casting of Al-Mg4.5 that are not explained by other theories.

Changes in solidified microstructures

NASA Technical Reports Server (NTRS)

Wallace, J. F.

1984-01-01

The properties and casting behavior of metals are significantly affected by their cast structure. This structure is optimized by producing columnar versus equiaxed grains and coarse versus fine grains by controlling solidification conditions. The transition from columnar to equiaxed grains is favored by: constitutional supercooling with effective nucleation of free dendrites; melting off and transport of dendrite tips and arms; mechanical vibration; falling down of free dendrites from a chilled top surface; and induced flow in the solidifying structure by oscillation of rotation.

Elimination of Hot Tears in Steel Castings by Means of Solidification Pattern Optimization

NASA Astrophysics Data System (ADS)

Kotas, Petr; Tutum, Cem Celal; Thorborg, Jesper; Hattel, Jesper Henri

2012-06-01

A methodology of how to exploit the Niyama criterion for the elimination of various defects such as centerline porosity, macrosegregation, and hot tearing in steel castings is presented. The tendency of forming centerline porosity is governed by the temperature distribution close to the end of the solidification interval, specifically by thermal gradients and cooling rates. The physics behind macrosegregation and hot tears indicate that these two defects also are dependent heavily on thermal gradients and pressure drop in the mushy zone. The objective of this work is to show that by optimizing the solidification pattern, i.e., establishing directional and progressive solidification with the help of the Niyama criterion, macrosegregation and hot tearing issues can be both minimized or eliminated entirely. An original casting layout was simulated using a transient three-dimensional (3-D) thermal fluid model incorporated in a commercial simulation software package to determine potential flaws and inadequacies. Based on the initial casting process assessment, multiobjective optimization of the solidification pattern of the considered steel part followed. That is, the multiobjective optimization problem of choosing the proper riser and chill designs has been investigated using genetic algorithms while simultaneously considering their impact on centerline porosity, the macrosegregation pattern, and primarily on hot tear formation.

Strip casting with fluxing agent applied to casting roll

DOEpatents

Williams, Robert S.; O'Malley, Ronald J.; Sussman, Richard C.

1997-01-01

A strip caster (10) for producing a continuous strip (24) includes a tundish (12) for containing a melt (14), a pair of horizontally disposed water cooled casting rolls (22) and devices (29) for electrostatically coating the outer peripheral chill surfaces (44) of the casting rolls with a powder flux material (56). The casting rolls are juxtaposed relative to one another for forming a pouting basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). A preferred flux is boron oxide having a melting point of about 550.degree. C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll.

Green Turning of FCD 700 Ductile Cast Iron Using Coated Carbide Tool

NASA Astrophysics Data System (ADS)

Rodzi, Mohd Nor Azmi Mohd; Ghani, Jaharah A.; Eghawail, A. M.; Othman, Kamal; Rahman, Mohd. Nizam Ab.; Haron, Che Hassan Che

2010-10-01

This paper presents the performance of carbide coated cutting insert in turning FCD700 ductile cast iron in various dry machining conditions (without air, using air and chilled air). The turning parameters studied were, cutting speed of 120 m/min., feed rate of 0.15 mm/rev-0.4 mm/rev, and depth of cut of 0.6 mm-1.0 mm. The results show that the tool life was significantly controlled by the type of air coolant used, whereas the cutting force and surface roughness were not influenced by these coolants. Chilled air was found to be significantly improved the tool life by about 30% and 40% respectively when compared with normal air and without air conditions. The wear mechanism was predominantly controlled by the flank and crater wears on the flank and rake faces respectively. Due to the low cutting speed used in the experiment, both flank and crater wears were uniformly formed along the cutting edge and no catastrophic failure was observed under the scanning electron microscope (SEM).

Cavitation erosion mechanism of titanium alloy radiation rods in aluminum melt.

PubMed

Dong, Fang; Li, Xiaoqian; Zhang, Lihua; Ma, Liyong; Li, Ruiqing

2016-07-01

Ultrasound radiation rods play a key role in introducing ultrasonic to the grain refinement of large-size cast aluminum ingots (with diameter over 800 mm), but the severe cavitation corrosion of radiation rods limit the wide application of ultrasonic in the metallurgy field. In this paper, the cavitation erosion of Ti alloy radiation rod (TARR) in the semi-continuous direct-chill casting of 7050 Al alloy was investigated using a 20 kHz ultrasonic vibrator. The macro/micro characterization of Ti alloy was performed using an optical digital microscopy and a scanning electron microscopy, respectively. The results indicated that the cavitation erosion and the chemical reaction play different roles throughout different corrosion periods. Meanwhile, the relationship between mass-loss and time during cavitation erosion was measured and analyzed. According to the rate of mass-loss to time, the whole cavitation erosion process was divided into four individual periods and the mechanism in each period was studied accordingly. Copyright © 2015 Elsevier B.V. All rights reserved.

[Comparison of texture distribution of cold rolled DC and CC AA 5052 aluminum alloy at different positions through thickness direction by XRD].

PubMed

Chen, Ming-biao; Ma, Min; Yang, Qing-xiang; Wang, Shan; Liu, Wen-chang; Zhao, Ying-mei

2013-09-01

To provide gist of DC AA 5052 and CC AA 5052 aluminum alloy to industry production and application, the texture variation of cold rolled sheets through thickness direction was studied by X-ray diffraction method, and the difference in texture at surface, quarter and center layer was analyzed. The hot plates of direct chill cast (DC) AA 5052 and continuous cast (CC) AA 5052 aluminum alloy were annealed at 454 degrees C for 4 hours and then cold rolled to different reductions. The strength and volume fraction of the fiber in CC AA 5052 aluminum alloy is larger than in DC AA 5052 aluminum alloy after same rolling reduction The volume fraction of the recrystallization texture cube in the CC AA 5052 aluminum alloy is less than in the DC AA 5052 aluminum alloy, which result in that CC AA 5052 aluminum alloy needs less cold rolling reduction than DC AA 5052 aluminum alloy for generating the texture with same intensity and volume fraction at surface layer, quarter layer and center layer. The manufacturability and performance of CC AA 5052 aluminum alloy is superior to DC AA 5052 aluminum alloy for use in stamping.

Aluminum-lithium alloys in helicopters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, A.F.

1997-10-01

Aluminium-lithium alloys are widely applied on the EH101 helicopter, designed and built jointly by GKN Westland Helicopters of England and Agusta S.p.A. of Italy. With the exception of the powder metallurgy alloy AA 5091, all the current commercially available aluminum-lithium alloys are produced by direct-chill casting, and require a precipitation-aging heat treatment to achieve the required properties. In aluminum-lithium alloys containing greater than 1.3% (by weight) of lithium, the intermetallic phase {delta}{prime}-Al{sub 3}Li precipitates upon natural or artificial aging, but the associated strengthening effect is insufficient to meet the medium or high strength levels usually required (the damage tolerant tempermore » in AA 8090 is an exception).« less

Filler metal alloy for welding cast nickel aluminide alloys

DOEpatents

Santella, Michael L.; Sikka, Vinod K.

1998-01-01

A filler metal alloy used as a filler for welding east nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and east in copper chill molds.

Plastic flow and microstructure of cast nickel aluminides at 1273 K

NASA Astrophysics Data System (ADS)

Schneibel, J. H.; Porter, W. D.; Horton, J. A.

1987-12-01

Chill-cast nickel aluminides based on Ni3Al were compression-tested in vacuum at 1273 K at strain rates ranging from 10-5 s-1 to 10-1 s-1. As the strain rate increases, the propensity for intergranular cracking increases. The ductile-to-brittle transition strain rate (DBTS) of as-cast Ni-22.5Al-0.5Hf-0.1B (at. pct) is approximately 10-1 s-1. Homogenization lowers this value by three orders of magnitude, to 10-4 s-1 (a homogenized specimen disintegrated completely at a rate of 10-3 s-1). The fine-grained structure of the as-cast alloy plays an important role in its relatively high DBTS. A hafnium-free alloy, Ni-24A1-0.1B, on the other hand, shows only a weak dependence of the DBTS on prior homogenization, and possible reasons for this finding are discussed.

Raising the Reliability of Forming Rolls by Alloying Their Core with Copper

NASA Astrophysics Data System (ADS)

Zhizhkina, N. A.

2016-11-01

The mechanical properties and the structure of forming rolls from cast irons of different compositions are studied. A novel iron including a copper additive that lowers its chilling and raises the homogeneity of the structure is suggested for the roll cores. The use of such iron should raise the reliability of the rolls in operation.

Cold resistance depends on acclimation and behavioral caste in a temperate ant

NASA Astrophysics Data System (ADS)

Modlmeier, Andreas P.; Pamminger, Tobias; Foitzik, Susanne; Scharf, Inon

2012-10-01

Adjusting to low temperatures is important for animals living in cold environments. We studied the chill-coma recovery time in temperate ant workers ( Temnothorax nylanderi) from colonies collected in autumn and spring in Germany. We experimentally acclimated these ant colonies to cold temperatures followed by warm temperatures. As expected, cold-acclimated workers recovered faster from freezing temperatures, but subsequent heat acclimation did not change the short recovery times observed after cold acclimation. Hence, either heat acclimation improves cold tolerance, possibly as a general response to stress, or at least it does not negate enhanced cold tolerance following cold acclimation. Colonies collected in spring showed similar cold tolerance levels to cold-acclimated colonies in the laboratory. Next, we compared the chill-coma recovery time of different worker castes and found that exterior workers recovered faster than interior workers. This difference may be related to their more frequent exposure to cold, higher activity level, or distinct physiology. Interior workers were also heavier and showed a higher gaster-to-head ratio and thorax ratio compared to exterior workers. An obvious difference between exterior and interior workers is activity level, but we found no link between activity and cold tolerance. This suggests that physiology rather than behavioral differences could cause the increased cold tolerance of exterior workers. Our study reveals the importance of acclimation for cold tolerance under natural and standardized conditions and demonstrates differences in cold tolerance and body dimensions in monomorphic behavioral castes of an ant.

Processing and Characterization of Functionally Graded Aluminum (A319)—SiCp Metallic Composites by Centrifugal Casting Technique

NASA Astrophysics Data System (ADS)

Jayakumar, E.; Jacob, Jibin C.; Rajan, T. P. D.; Joseph, M. A.; Pai, B. C.

2016-08-01

Functionally graded materials (FGM) are successfully adopted for the design and fabrication of engineering components with location-specific properties. The present study describes the processing and characterization of A319 Aluminum functionally graded metal matrix composites (FGMMC) with 10 and 15 wt pct SiCp reinforcements. The liquid stir casting method is used for composite melt preparation followed by FGMMC formation by vertical centrifugal casting method. The process parameters used are the mold preheating temperature of 523 K (250 °C), melt pouring temperature of 1013 K (740 °C), and mold rotation speed of 1300 rpm. The study analyzes the distribution and concentration of reinforcement particles in the radial direction of the FGMMC disk along with the effects of gradation on density, hardness, mechanical strength, the variation in coefficient of thermal expansion and the wear resistance properties at different zones. Microstructures of FGMMC reveal an outward radial gradient distribution of reinforcements forming different zones. Namely, matrix-rich inner, transition, particles-rich outer, and chill zone of a few millimeters thick at the outer most periphery of the casting are formed. From 10-FGM, a radial shift in the position of SiCp maxima is observed in 15-FGM casting. The mechanical characterization depicts enhanced properties for the particle-rich zone. The hardness shows a graded nature in correlation with particle concentration and a maximum of 94.4 HRB has been obtained at the particle-rich region of 15-FGM. In the particle-rich zone, the lowest CTE value of 20.1 µm/mK is also observed with a compressive strength of 650 MPa and an ultimate tensile strength of 279 MPa. The wear resistance is higher at the particle-rich zone of the FGMMC.

Dormancy release and flowering time in Ziziphus jujuba Mill., a "direct flowering" fruit tree, has a facultative requirement for chilling.

PubMed

Meir, Michal; Ransbotyn, Vanessa; Raveh, Eran; Barak, Simon; Tel-Zur, Noemi; Zaccai, Michele

2016-03-15

In deciduous fruit trees, the effect of chilling on flowering has mostly been investigated in the "indirect flowering" group, characterized by a period of rest between flower bud formation and blooming. In the present study, we explored the effects of chilling and chilling deprivation on the flowering of Ziziphus jujuba, a temperate deciduous fruit tree belonging to the "direct flowering" group, in which flower bud differentiation, blooming and fruit development occur after dormancy release, during a single growing season. Dormancy release, vegetative growth and flowering time in Z. jujuba cv. Ben-Li were assessed following several treatments of chilling. Chilling treatments quantitatively decreased the timing of vegetative bud dormancy release, thereby accelerating flowering, but had no effect on the time from dormancy release to flowering. Trees grown at a constant temperature of 25°C, without chilling, broke dormancy and flowered, indicating the facultative character of chilling in this species. We measured the expression of Z. jujuba LFY and AP1 homologues (ZjLFY and ZjAP1). Chilling decreased ZjLFY expression in dormant vegetative buds but had no effect on ZjAP1expression, which reached peak expression before dormancy release and at anthesis. In conclusion, chilling is not obligatory for dormancy release of Z. jujuba cv. Ben-Li vegetative buds. However, the exposure to chilling during dormancy does accelerate vegetative bud dormancy release and flowering. Copyright © 2016 Elsevier GmbH. All rights reserved.

In-situ conditioning of a strip casting roll

DOEpatents

Williams, Robert S.; Campbell, Steven L.

1997-01-01

A strip caster (10) for producing a continuous strip (24) has a tundish (12) for containing a melt (14) and a pair of horizontally disposed water cooled casting rolls (22). The casting rolls are juxtaposed relative to one another for forming a pouring basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming a strip (24). The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). Devices (29) for conditioning the outer peripheral chill surfaces of the casting rolls includes grit blasting nozzles (30A, 30B, 30C, 30D), a collection trough (32) for gathering the grit, a line (34) for recycling the grit to a bag house (36), a feeder (38) and a pressurized distributor (40) for delivering the grit to the nozzles. The conditioning nozzles remove dirt, metal oxides and surface imperfections providing a clean surface readily wetted by the melt.

In-situ conditioning of a strip casting roll

DOEpatents

Williams, R.S.; Campbell, S.L.

1997-07-29

A strip caster (10) for producing a continuous strip (24) has a tundish (12) for containing a melt (14) and a pair of horizontally disposed water cooled casting rolls (22). The casting rolls are juxtaposed relative to one another for forming a pouring basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming a strip (24). The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). Devices (29) for conditioning the outer peripheral chill surfaces of the casting rolls includes grit blasting nozzles (30A, 30B, 30C, 30D), a collection trough (32) for gathering the grit, a line (34) for recycling the grit to a bag house (36), a feeder (38) and a pressurized distributor (40) for delivering the grit to the nozzles. The conditioning nozzles remove dirt, metal oxides and surface imperfections providing a clean surface readily wetted by the melt.

Pre-sowing Seed Treatments in Direct-seeded Early Rice: Consequences for Emergence, Seedling Growth and Associated Metabolic Events under Chilling Stress

NASA Astrophysics Data System (ADS)

Wang, Weiqin; Chen, Qian; Hussain, Saddam; Mei, Junhao; Dong, Huanglin; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Nie, Lixiao

2016-01-01

Double direct-seeding for double rice cropping is a simplified, labor saving, and efficient cropping system to improve multiple-crop index and total rice production in central China. However, poor crop establishment of direct-seeded early rice due to chilling stress is the main obstacle to wide spread of this system. A series of experiments were conducted to unravel the effects of pre-sowing seed treatments on emergence, seedling growth and associated metabolic events of direct-seeded early rice under chilling stress. Two seed priming treatments and two seed coating treatments were used in all the experiments. A non-treated control treatment was also maintained for comparison. In both the field and growth chamber studies, seed priming with selenium or salicylic acid significantly enhanced the emergence and seedling growth of rice compared with non-treated control. Nevertheless, such positive effects were not apparent for seed coating treatments. Better emergence and vigorous seedling growth of rice after seed priming was associated with enhanced α-amylase activity, higher soluble sugars contents, and greater respiration rate in primed rice seedlings under chilling stress. Taking together, these findings may provide new avenues for understanding and advancing priming-induced chilling tolerance in direct-seeded early rice in double rice cropping system.

{l_angle}110{r_angle} dendrite growth in aluminum feathery grains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henry, S.; Rappaz, M.; Jarry, P.

1998-11-01

Automatic indexing of electron backscattered diffraction patterns, scanning electron microscopy, and optical microscopy observations have been carried out on aluminum-magnesium-silicon, aluminum-copper, and aluminum-silicon alloys directionally solidified or semicontinuously cast using the direct chill casting process. From these combined observations, it is shown that the feathery grains are made of {l_angle}110{r_angle} primary dendrite trunks (e.g., [011{bar 1}]) split in their centers by a coherent (111) twin plane. The average spacing of the dendrite trunks in the twin plane (about 10 to 20 {micro}m) is typically one order of magnitude smaller than that separating successive rows of trunks (or twin planes). Themore » [011{bar 1}] orientation of these trunks is close to the thermal gradient direction (typically within 15 deg)--a feature probably resulting from a growth competition mechanism similar to that occurring during normal <100> columnar dendrite growth. On both sides of these trunks, secondary dendrite arms also grow along {l_angle}110{r_angle} directions. Their impingement creates wavy noncoherent twin boundaries between the coherent twin planes. In the twin plane, evidence is shown that {l_angle}110{r_angle} branching mechanisms lead to the propagation of the twinned regions, to the regular arrangement of the primary dendrite trunks along a [{bar 2}11] direction, and to coherent planar twin boundaries. From these observations, it is concluded that the feathery grains are probably the result of a change from a normal <100> to a {l_angle}110{r_angle} surface tension/attachment kinetics anisotropy growth mode. Finally, the proposed mechanisms of leathery grain growth are further supported by the observation of {l_angle}110{r_angle} dendrite growth morphologies in thin aluminum-zinc coatings.« less

Formation of Hot Tear Under Controlled Solidification Conditions

NASA Astrophysics Data System (ADS)

Subroto, Tungky; Miroux, Alexis; Bouffier, Lionel; Josserond, Charles; Salvo, Luc; Suéry, Michel; Eskin, Dmitry G.; Katgerman, Laurens

2014-06-01

Aluminum alloy 7050 is known for its superior mechanical properties, and thus finds its application in aerospace industry. Vertical direct-chill (DC) casting process is typically employed for producing such an alloy. Despite its advantages, AA7050 is considered as a "hard-to-cast" alloy because of its propensity to cold cracking. This type of cracks occurs catastrophically and is difficult to predict. Previous research suggested that such a crack could be initiated by undeveloped hot tears (microscopic hot tear) formed during the DC casting process if they reach a certain critical size. However, validation of such a hypothesis has not been done yet. Therefore, a method to produce a hot tear with a controlled size is needed as part of the verification studies. In the current study, we demonstrate a method that has a potential to control the size of the created hot tear in a small-scale solidification process. We found that by changing two variables, cooling rate and displacement compensation rate, the size of the hot tear during solidification can be modified in a controlled way. An X-ray microtomography characterization technique is utilized to quantify the created hot tear. We suggest that feeding and strain rate during DC casting are more important compared with the exerted force on the sample for the formation of a hot tear. In addition, we show that there are four different domains of hot-tear development in the explored experimental window—compression, microscopic hot tear, macroscopic hot tear, and failure. The samples produced in the current study will be used for subsequent experiments that simulate cold-cracking conditions to confirm the earlier proposed model.

New Directions for Evaporative Cooling Systems.

ERIC Educational Resources Information Center

Robison, Rita

1981-01-01

New energy saving technology can be applied to older cooling towers; in addition, evaporative chilling, a process that links a cooling tower to the chilling equipment, can reduce energy use by 80 percent. (Author/MLF)

Insights on the development, kinetics, and variation of photoinhibition using chlorophyll fluorescence imaging of a chilled, variegated leaf.

PubMed

Hogewoning, Sander W; Harbinson, Jeremy

2007-01-01

The effect of chilling on photosystem II (PSII) efficiency was studied in the variegated leaves of Calathea makoyana, in order to gain insight into the causes of chilling-induced photoinhibition. Additionally, a relationship was revealed between (chilling) stress and variation in photosynthesis. Chilling treatments (5 degrees C and 10 degrees C) were performed for different durations (1-7 d) under a moderate irradiance (120 micromol m-2 s-1). The individual leaves were divided into a shaded zone and two illuminated, chilled zones. The leaf tip and sometimes the leaf base were not chilled. Measurements of the dark-adapted Fv/Fm were made on the different leaf zones at the end of the chilling treatment, and then for several days thereafter to monitor recovery. Chilling up to 7 d in the dark did not affect PSII efficiency and visual appearance, whereas chilling in the light caused severe photoinhibition, sometimes followed by leaf necrosis. Photoinhibition increased with the duration of the chilling period, whereas, remarkably, chilling temperature had no effect. In the unchilled leaf tip, photoinhibition also occurred, whereas in the unchilled leaf base it did not. Whatever the leaf zone, photoinhibition became permanent if the mean value dropped below 0.4, although chlorosis and necrosis were associated solely with chilled illuminated tissue. Starch accumulated in the unchilled leaf tip, in contrast to the adjacent chilled irradiated zone. This suggests that photoinhibition was due to a secondary effect in the unchilled leaf tip (sink limitation), whereas it was a direct effect of chilling and irradiance in the chilled illuminated zones. The PSII efficiency and its coefficient of variation showed a unique negative linearity across all leaf zones and different tissue types. The slope of this curve was steeper for chilled leaves than it was for healthy, non-stressed leaves, suggesting that the coefficient of variation may be an important tool for assessing stress in leaves.

Effect of Homogenizing Heat Treatment of Liquid Aluminum-Copper Alloys on the Structure of Rapidly Crystallized Specimens

NASA Astrophysics Data System (ADS)

Astaf'ev, V. V.; Kurochkin, A. R.; Yablonskikh, T. I.; Brodova, I. G.; Popel', P. S.

2017-11-01

Centrifugal casting into a massive slot chill mold was used to prepare two series of specimens of alloys of the Al - Cu system, containing from 10 to 32.2 at.% Cu. The first series was fabricated without a homogenizing heat treatment of the melt, while the second series was fabricated with heating of the melt to 1400°C. Both kinds of specimens were cast at the same temperature in order to provide for the same cooling rate of about 104 K/sec. The structures, phase compositions and microhardnesses of the structural components are compared. It is established that the homogenizing heat treatment changes the kinetics of crystallization and, hence, the proportion of phases in the alloy structure and the copper content in them.

Evolution of Constitution, Structure, and Morphology in FeCo-Based Multicomponent Alloys

NASA Astrophysics Data System (ADS)

Li, R.; Stoica, M.; Liu, G.; Eckert, J.

2010-07-01

Constituent phases, melting behaviors, and microstructure of multicomponent (Fe0.5Co0.5) x (Mo0.1C0.2B0.5Si0.2)100- x alloys ( x = 95, 90, 85, 80, and 70) produced by copper mold casting were evaluated by various analysis techniques, i.e., X-ray diffractometry, scanning electronic microscopy with energy dispersive X-ray spectrometry, and differential scanning calorimetry. Metastable Fe3C- and Cr23C6-type phases were identified in the chill-cast alloys. A schematic illustration was proposed to explain the evolution of constituent phases and microstructure for the alloys with x = 95, 90, and 85 during the solidification process, which could be applicable to controlling microstructural formation of other multicomponent alloys with similar microstructures by artificially adjusting the composition.

Resistance to High-Temperature Oxidation and Wear of Various Ferrous Alloys Used in Rolling Mills

NASA Astrophysics Data System (ADS)

Delaunois, Fabienne; Stanciu, Victor Ioan; Sinnaeve, Mario

2018-03-01

Various materials are commonly used to manufacture work rolls for hot rolling mills, such as ICDP (Indefinite Chill Double Pour) cast irons, high-chromium white cast irons, and high speed steels (HSS). Various chemical compositions and microstructures are studied in order to optimize the in-use behavior of those grades of rolls. In this paper, six grades of ferrous alloys (an ICDP cast iron; an ICDP cast iron enriched in vanadium, niobium, and molybdenum; a HSS; a graphitic HSS; a high-chromium white cast iron (Hi-Cr); and a niobium-molybdenum-doped high-chromium white cast iron) were investigated. High-temperature oxidation tests with gravimetric means at 575 °C in water vapor atmosphere and sliding wear tests were carried out. The oxidation kinetics was followed during oxidation test. The microstructure was observed by optical and scanning electron microscopies. The oxides formed on the surface of the samples were analyzed by XRD and EDS. The thickness of the oxide scales and the mass gain were measured after oxidation test. The results showed that the behavior of all the grades differed. The oxide scale of HSS and HSS-G grades was fine and their friction coefficient was low. The weight gain after oxidation test of HSS was high. Hi-Cr and M-Hi-Cr grades presented highly porous oxide layer and an important increase of the friction coefficient during wear test. ICDP and M-ICDP had intermediate behavior.

Effect of microstructure and surface features on wetting angle of a Fe-3.2 wt%C.E. cast iron with water

NASA Astrophysics Data System (ADS)

Riahi, Samira; Niroumand, Behzad; Dorri Moghadam, Afsaneh; Rohatgi, Pradeep K.

2018-05-01

In the present study, variation in surface wetting behavior of a hypoeutectic cast iron with its microstructural features and surface roughness was investigated. Samples with an identical composition, i.e. Fe-3.2 wt%C.E., and different microstructures (a gray cast iron with A-type flake graphite and a white cast iron) were fabricated by gravity casting of molten cast iron in a chill mold at different cooling rates. A variation of surface roughness was also developed by polishing, a four-stage electroetching and a four-stage mechanical abrading on the samples. Roughness and water contact angles of all surfaces were then measured. The surface roughness factor and the solid fraction in contact with water by the Wenzel and Cassie-Baxter contact models were also calculated and compared with the corresponding measured contact angles to find out which regime was active. Results indicated that the surface microstructure and the type of constituents present at the surface influenced the cast iron surface wettability and that it was possible to change the surface contact angle by modification of the surface microstructure. The mechanically abraded gray cast iron followed the Wenzel-type regime while the electroetched surfaces of gray cast iron exhibited a transition from Wenzel to Cassie-Baxter type regime. In white cast iron, the results indicated Wenzel type behavior in the electroetched samples while for the mechanically abraded samples, none of these two models could predict the wetting behavior. Furthermore, the wetting angles of both gray and white cast irons were measured after 1, 2, 3 and 4 weeks of air exposure. The results showed that the wetting angles of both samples increased to above 90° after one week of air exposure which was likely due to adsorption of low surface energy hydrocarbons on the surfaces.

Prominent November Coldwaves in the North Central United States Since 1901.

NASA Astrophysics Data System (ADS)

Wendland, Wayne M.

1987-06-01

The frequency and intensity of early winter (November) coldwaves were investigated for the north central United States. Twenty-two such storms occurred from 1901 to 1985, and were most frequent in the 1950s and early 1960s, and again from the mid 1970s to the present.November coldwaves are most often the result of Colorado cyclones moving to the cast northeast. On average, temperature declines of 22°C or more within 24 hours, falling to at least 0°C, impacted about 40 percent of the 12-state region. The storms were most often accompanied by strong winds, wind chill, heavy snow to the west, and thunderstorms to the cast, i.e., the trappings of a severe winter storm. Many of these storms inflicted severe damage on land and on the Great Lakes, sometimes taking lives of those not anticipating such a severe "winter" storm in November.

Rapid-Chill Cryogenic Coaxial Direct-Acting Solenoid Valve

NASA Technical Reports Server (NTRS)

Richard, James; Castor, Jim; Sheller, Richard

2006-01-01

A commercially available cryogenic direct- acting solenoid valve has been modified to incorporate a rapid-chill feature. The net effect of the modifications is to divert some of the cryogenic liquid to the task of cooling the remainder of the cryogenic liquid that flows to the outlet. Among the modifications are the addition of several holes and a gallery into a valve-seat retainer and the addition of a narrow vent passage from the gallery to the atmosphere.

Role of Rbp1 in the acquired chill-light tolerance of cyanobacteria.

PubMed

Tan, Xiaoming; Zhu, Tao; Shen, Si; Yin, Chuntao; Gao, Hong; Xu, Xudong

2011-06-01

Synechocystis sp. strain PCC 6803 cultured at 30°C losses viability quickly under chill (5°C)-light stress but becomes highly tolerant to the stress after conditioning at 15°C (Y. Yang, C. Yin, W. Li, and X. Xu, J. Bacteriol. 190:1554-1560, 2008). Hypothetically, certain factors induced during preconditioning are involved in acquisition of chill-light tolerance. In this study, Rbp1 (RNA-binding protein 1) rather than Rbp2 was found to be accumulated during preconditioning, and the accumulation of Rbp1 was correlated with the increase of chill-light tolerance. Inactivation of its encoding gene rbp1 led to a great reduction in the acquired chill-light tolerance, while ectopic expression of rbp1 enabled the cyanobacterium to survive the chill-light stress without preconditioning. Microarray analyses suggested that the Rbp1-dependent chill-light tolerance may not be based on its influence on mRNA abundance of certain genes. Similarly to that in Synechocystis, the Rbp1 homologue(s) can be accumulated in Microcystis cells collected from a subtropic lake in low-temperature seasons. Rbp1 is the first factor shown to be both accumulated early during preconditioning and directly involved in development of chill-light tolerance in Synechocystis. Its accumulation may greatly enhance the overwintering capability in certain groups of cyanobacteria.

Relevance of calpain and calpastatin activity for texture in super-chilled and ice-stored Atlantic salmon (Salmo salar L.) fillets.

PubMed

Gaarder, M Ø; Bahuaud, D; Veiseth-Kent, E; Mørkøre, T; Thomassen, M S

2012-05-01

The aim of the present experiment was to measure the protease activities in ice-stored and super-chilled Atlantic salmon (Salmo salar) fillets, and the effect on texture. Pre-rigour fillets of Atlantic salmon were either super-chilled to a core temperature of -1.5°C or directly chilled on ice prior to 144h of ice storage. A significantly higher calpain activity was detected in the super-chilled fillets at 6h post-treatment compared to the ice-stored fillets and followed by a significant decrease below its initial level, while the calpastatin activity was significantly lower for the super-chilled fillets at all time points. The cathepsin B+L and B activities increased significantly with time post-treatment; however, no significant differences were observed at any time points between the two treatments. For the ice stored fillets, the cathepsin L activity decreased significantly from 6 to 24h post-treatment and thereafter increased significantly to 144h post-treatment. There was also a significantly lower cathepsin L activity in the super-chilled fillets at 0h post-treatment. No significant difference in breaking force was detected; however, a significant difference in maximum compression (Fmax) was detected at 24h post-treatment with lower Fmax in the super-chilled fillets. This experiment showed that super-chilling had a significant effect on the protease activities and the ATP degradation in salmon fillets. The observed difference in Fmax may be a result of these observed differences, and may indicate a softening of the super-chilled salmon muscle at 24h post-treatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characteristics of high-quality Asian elephant (Elephas maximus) ejaculates and in vitro sperm quality after prolonged chilled storage and directional freezing.

PubMed

O'Brien, J K; Steinman, K J; Montano, G A; Love, C C; Saiers, R L; Robeck, T R

2013-01-01

The in vitro quality of spermatozoa from one elephant (Elephas maximus) was examined after chilled storage and directional freezing (DF). High-quality, non-contaminated ejaculates (77.6±6.0% progressive motility, 3.9±1.5 µg creatinine mL(-1) raw semen, 2.7±0.6% detached heads) were cryopreserved after 0 (0hStor), 12 (12hStor) and 24 h (24hStor) of chilled storage. At 0 h and 6h post-thawing, total motility, plasma membrane integrity, acrosome integrity, mitochondrial activity and normal morphology were similar (P>0.05) across treatments. In contrast, progressive motility, rapid velocity and several kinematic parameters were lower (P<0.05) for 24Stor compared with 0hStor at 0 h post-thaw. By 6 h post-thaw, amplitude of lateral head displacement and velocity parameters (average pathway, straight-line and curvilinear velocity) were lower (P<0.05) for 24hStor compared with 0hStor and 12hStor. DNA integrity was high and remained unchanged (P>0.05) across all groups and processing stages (1.6±0.6% of cells contained fragmented DNA). Results indicate that DF after up to 12 h of chilled storage results in a post-thaw sperm population of acceptable quality for artificial insemination. These findings have implications for the cryopreservation of sex-sorted spermatozoa, which typically undergo more than 12 h of chilled storage prior to sorting and preservation.

Influence of Homogenization on Microstructural Response and Mechanical Property of Al-Cu-Mn Alloy.

PubMed

Wang, Jian; Lu, Yalin; Zhou, Dongshuai; Sun, Lingyan; Li, Renxing; Xu, Wenting

2018-05-29

The evolution of the microstructures and properties of large direct chill (DC)-cast Al-Cu-Mn alloy ingots during homogenization was investigated. The results revealed that the Al-Cu-Mn alloy ingots had severe microsegregation and the main secondary phase was Al₂Cu, with minimal Al₇Cu₂Fe phase. Numerous primary eutectic phases existed in the grain boundary and the main elements were segregated at the interfaces along the interdendritic region. The grain boundaries became discontinuous, residual phases were effectively dissolved into the matrix, and the segregation degree of all elements was reduced dramatically during homogenization. In addition, the homogenized alloys exhibited improved microstructures with finer grain size, higher number density of dislocation networks, higher density of uniformly distributed θ' or θ phase (Al₂Cu), and higher volume fraction of high-angle grain boundaries compared to the nonhomogenized samples. After the optimal homogenization scheme treated at 535 °C for 10 h, the tensile strength and elongation% were about 24 MPa, 20.5 MPa, and 1.3% higher than those of the specimen without homogenization treatment.

New horizon for high performance Mg-based biomaterial with uniform degradation behavior: Formation of stacking faults

PubMed Central

Zhang, Jinghuai; Xu, Chi; Jing, Yongbin; Lv, Shuhui; Liu, Shujuan; Fang, Daqing; Zhuang, Jinpeng; Zhang, Milin; Wu, Ruizhi

2015-01-01

Designing the new microstructure is an effective way to accelerate the biomedical application of magnesium (Mg) alloys. In this study, a novel Mg–8Er–1Zn alloy with profuse nano-spaced basal plane stacking faults (SFs) was prepared by combined processes of direct-chill semi-continuous casting, heat-treatment and hot-extrusion. The formation of SFs made the alloy possess outstanding comprehensive performance as the biodegradable implant material. The ultimate tensile strength (UTS: 318 MPa), tensile yield strength (TYS: 207 MPa) and elongation (21%) of the alloy with SFs were superior to those of most reported degradable Mg-based alloys. This new alloy showed acceptable biotoxicity and degradation rate (0.34 mm/year), and the latter could be further slowed down through optimizing the microstructure. Most amazing of all, the uniquely uniform in vitro/vivo corrosion behavior was obtained due to the formation of SFs. Accordingly we proposed an original corrosion mechanism for the novel Mg alloy with SFs. The present study opens a new horizon for developing new Mg-based biomaterials with highly desirable performances. PMID:26349676

Effect of fecal contamination and cross-contamination on numbers of coliform, Escherichia coli, Campylobacter, and Salmonella on immersion-chilled broiler carcasses.

PubMed

Smith, D P; Cason, J A; Berrang, M E

2005-07-01

The effect of prechill fecal contamination on numbers of bacteria on immersion-chilled carcasses was tested in each of three replicate trials. For each trial, 16 eviscerated broiler carcasses were split into 32 halves and assigned to one of two groups. Cecal contents (0.1 g inoculated with Campylobacter and nalidixic acid-resistant Salmonella) were applied to each of eight halves in one group (direct contamination) that were placed into one paddle chiller (contaminated), whereas the other paired halves were placed into another chiller (control). From the second group of eight split birds, one of each paired half was placed in the contaminated chiller (to determine cross-contamination) and the other half was placed in the control chiller. Postchill carcass halves were sampled by a 1-min rinse in sterile water, which was collected and cultured. Bacterial counts were reported as log CFU per milliliter of rinsate. There were no significant statistical differences (paired t test, P < 0.05) from direct contamination for coliforms (mean 3.0 log CFU) and Escherichia coli (mean 2.7 log CFU), although Campylobacter numbers significantly increased from control values because of direct contamination (1.5 versus 2.1 log CFU), and the incidence increased from 79 to 100%. There was no significant effect of cross-contamination on coliform (mean 2.9 log CFU) or E. coli (mean 2.6 log CFU) numbers. Nevertheless, Campylobacter levels were significantly higher after exposure to cross-contamination (1.6 versus 2.0 log CFU), and the incidence of this bacterium increased from 75 to 100%. Salmonella-positive halves increased from 0 to 42% postchill because of direct contamination and from 0 to 25% as a result of cross-contamination after chilling. Water samples and surface swabs taken postchill from the contaminated chiller were higher for Campylobacter than those taken from the control chiller. Immersion chilling equilibrated bacterial numbers between contaminated and control halves subjected to either direct contamination or cross-contamination for coliforms and E. coli. Campylobacter numbers, Campylobacter incidence, and Salmonella incidence increased because of both direct contamination and cross-contamination in the chiller. Postchill E. coli numbers did not indicate which carcass halves were contaminated with feces before chilling.

Warming and Chilling: Assessing Aspects of Changing Plant Ecology with Continental-scale Phenology

NASA Astrophysics Data System (ADS)

Schwartz, M. D.; Hanes, J. M.

2009-12-01

Many recent ecological studies have concentrated on the direct impacts of climate warming, such as modifications to seasonal plant and animal life cycle events (phenology). There are many examples, with most indicating earlier onset of spring plant growth and delayed onset of autumn senescence. However, the implication of continued warming for plant species’ chilling requirements has received comparatively less attention. Temperate zone woody plants often require a certain level of cool season "chilling" (accumulated time at temperatures below a specific threshold) to break dormancy and prepare to respond to springtime warming. Thus, the potential impacts of insufficient chilling must be included in a comprehensive assessment of plant species' responses to climate warming. Vegetation phenological data, when collected for specific plant species at continental-scale, can be used to extract information relating to the combined impacts of reduced chilling and warming on plant species physiology. In a recent study, we demonstrated that common lilac first leaf and first bloom phenology (collected from multiple locations in the western United States and matched with air temperature records) can estimate the species' chilling requirement (in this case 1748 chilling hours, below a base temperature of 7.2°C) and highlight the changing impact of warming on the plant's phenological response in light of that requirement. Specifically, when chilling is above the requirement, lilac first leaf dates advance at a rate of -5.0 days per 100 hour chilling accumulation reduction, and lilac first bloom dates advance at a rate of -4.2 days per 100 hour chilling accumulation reduction. In contrast, when chilling is below the requirement, the lilac event dates advance at a much reduced rate of -1.6 days per 100 hour reduction for first leaf date and -2.2 days per 100 hour reduction for first bloom date. Overall, these encouraging results for common lilac suggest that similar continental-scale phenological measurements could facilitate a better understanding of relationships among phenological response, springtime warming, and chilling requirements for other species. Further, it should be possible to address more detailed follow-up plant ecology questions in future studies using similar methodology. Example questions would include: 1) Are the chilling requirements for a species the same across its entire range? 2) Do species adapt to warming conditions by changing their chilling requirements? and 3) How much variation is there among species chilling requirements within the same community? Continental-scale phenological data sets are being developed by the USA National Phenology Network (http://www.usanpn.org), that will facilitate such investigations, and in turn be essential for understanding of (and eventually consideration of possible adaptations to) the coming impacts of climate warming on temperate plant communities. Additionally, these phenological data, because they provide plants species’ responses across large portions of species geographic ranges, will facilitate deeper understanding of the full range of plant-environment responses and consequently foster development of more robust phenological models.

Induction of bulb organogenesis in in vitro cultures of tarda tulip (Tulipa tarda Stapf.) from seed-derived explants.

PubMed

Maślanka, Małgorzata; Bach, Anna

2014-01-01

A protocol for obtaining bulbs via in vitro organogenesis was developed for tarda tulip ( Tulipa tarda Stapf). Scale explants were obtained from bulbs formed at the base of seedlings or from adventitious bulbs that developed from callus tissue forming on stolons or on germinating seeds. Some explants were subjected to chilling at 5°C for 12 wk. The culture media contained 3 or 6% sucrose and was supplemented with either no growth regulators, either 0.5 μM 6-benzyl-aminopurine (BAP) or 18.9 or 94.6 μM abscisic acid (ABA). Cultures were maintained in the dark at 20°C. Callus tissue developed mainly on media without growth regulators or with BAP. Callus was formed from up to 96% of explants derived from non-chilled adventitious bulbs that were treated with 3% sucrose and 0.5 μM BAP. Less callus was formed from chilled explants compared with non-chilled explants. Newly formed adventitious bulbs appeared on the explants via direct and indirect organogenesis. The media with BAP promoted the formation of adventitious bulbs at a rate of 56-92% from non-chilled explants, whereas a maximum rate of 36% was observed from chilled explants. ABA inhibited the induction of adventitious bulbs and callus. The adventitious bulbs obtained in these experiments contained a meristem, which was evidence that they had developed properly.

Chemical additive to enhance antimicrobial efficacy of chlorine and control cross-contamination during immersion chill of broiler carcasses.

PubMed

Schambach, B T; Berrang, M E; Harrison, M A; Meinersmann, R J

2014-09-01

Immersion chilling of broiler carcasses can be a site for cross-contamination between the occasional highly contaminated carcass and those that are co-chilled. Chlorine is often used as an antimicrobial but can be overcome by organic material. A proprietary chlorine stabilizer (T-128) based on phosphoric acid-propylene glycol was tested as a chill tank additive in experiments simulating commercial broiler chilling. In bench-scale experiments, 0.5% T-128 was compared with plain water (control), 50 ppm of chlorine, and the combination of 0.5% T-128 with 50 ppm of chlorine to control transfer of Salmonella and Campylobacter from inoculated wing drummettes to co-chilled uninoculated drummettes. Both chlorine and T-128 lessened cross-contamination with Salmonella (P < 0.05); T-128 and T-128 with chlorine were significantly more effective (P < 0.05) than the control or plain chlorine for control of Campylobacter. T-128 treatments were noted to have a pH of less than 4.0; an additional experiment demonstrated that the antimicrobial effect of T-128 was not due merely to a lower pH. In commercial broiler chilling, a pH close to 6.0 is preferred to maximize chlorine effectiveness, while maintaining water-holding capacity of the meat. In a set of pilot-scale experiments with T-128, a near-ideal pH of 6.3 was achieved by using tap water instead of the distilled water used in bench-scale experiments. Pilot-scale chill tanks were used to compare the combination of 0.5% T-128 and 50 ppm of chlorine with 50 ppm of plain chlorine for control of cross-contamination between whole carcasses inoculated with Salmonella and Campylobacter and co-chilled uninoculated carcasses. The T-128 treatment resulted in significantly less crosscontamination by either direct contact or water transfer with both organisms compared with plain chlorine treatment. T-128 may have use in commercial broiler processing to enhance the effectiveness of chlorine in processing water.

Modeling transport phenomena and uncertainty quantification in solidification processes

NASA Astrophysics Data System (ADS)

Fezi, Kyle S.

Direct chill (DC) casting is the primary processing route for wrought aluminum alloys. This semicontinuous process consists of primary cooling as the metal is pulled through a water cooled mold followed by secondary cooling with a water jet spray and free falling water. To gain insight into this complex solidification process, a fully transient model of DC casting was developed to predict the transport phenomena of aluminum alloys for various conditions. This model is capable of solving mixture mass, momentum, energy, and species conservation equations during multicomponent solidification. Various DC casting process parameters were examined for their effect on transport phenomena predictions in an alloy of commercial interest (aluminum alloy 7050). The practice of placing a wiper to divert cooling water from the ingot surface was studied and the results showed that placement closer to the mold causes remelting at the surface and increases susceptibility to bleed outs. Numerical models of metal alloy solidification, like the one previously mentioned, are used to gain insight into physical phenomena that cannot be observed experimentally. However, uncertainty in model inputs cause uncertainty in results and those insights. The analysis of model assumptions and probable input variability on the level of uncertainty in model predictions has not been calculated in solidification modeling as yet. As a step towards understanding the effect of uncertain inputs on solidification modeling, uncertainty quantification (UQ) and sensitivity analysis were first performed on a transient solidification model of a simple binary alloy (Al-4.5wt.%Cu) in a rectangular cavity with both columnar and equiaxed solid growth models. This analysis was followed by quantifying the uncertainty in predictions from the recently developed transient DC casting model. The PRISM Uncertainty Quantification (PUQ) framework quantified the uncertainty and sensitivity in macrosegregation, solidification time, and sump profile predictions. Uncertain model inputs of interest included the secondary dendrite arm spacing, equiaxed particle size, equiaxed packing fraction, heat transfer coefficient, and material properties. The most influential input parameters for predicting the macrosegregation level were the dendrite arm spacing, which also strongly depended on the choice of mushy zone permeability model, and the equiaxed packing fraction. Additionally, the degree of uncertainty required to produce accurate predictions depended on the output of interest from the model.

The expression patterns of bromelain and AcCYS1 correlate with blackheart resistance in pineapple fruits submitted to postharvest chilling stress.

PubMed

Raimbault, Astrid-Kim; Zuily-Fodil, Yasmine; Soler, Alain; Mora, Phillipe; Cruz de Carvalho, Maria H

2013-11-01

Blackheart is a physiological disorder induced by postharvest chilling storage during pineapple fruit export shipping. The aim of this study was to check the involvement of bromelain, the cysteine protease protein family abundantly present in pineapple fruits, and AcCYS1, an endogenous inhibitor of bromelain, in the development of blackheart. For this we checked the response to postharvest chilling treatment of two pineapple varieties (MD2 and Smooth Cayenne) differing in their resistance to blackheart. Quantitative RT-PCR analyses showed that postharvest chilling treatment induced a down-regulation of bromelain transcript accumulation in both varieties with the most dramatic drop in the resistant variety. Regarding AcCYS1 transcript accumulation, the varieties showed opposite trends with an up-regulation in the case of the resistant variety and a down-regulation in the susceptible one. Taken together our results suggest that the control of bromelain and AcCYS1 expression levels directly correlates to the resistance to blackheart development in pineapple fruits. Copyright © 2013 Elsevier GmbH. All rights reserved.

The Fatty Acid Composition of Phosphatidylglycerol and Sulfoquinovosyldiacylglycerol of Higher Plants in Relation to Chilling Sensitivity

PubMed Central

Kenrick, Janette R.; Bishop, David G.

1986-01-01

The fatty acid composition of phosphatidylglycerol and sulfoquinovosyldiacylglycerol has been measured in the leaves of 27 species of higher plants from six families whose members differed in their degrees of chilling sensitivity. The content of high melting point fatty acids (represented by the sum of hexadecanoic, trans-3-hexadecenoic and octadecanoic acids) in phosphatidylglycerols varied little between members of the same plant family and was not obviously related to the relative chilling sensitivity of members of that family. The saturated fatty acid content (hexadecanoic + octadecanoic acids) of sulfoquinovosyldiacylglycerols also appeared to be characteristic of a plant family, although some exceptions were found. In one case, (Carica papaya) the content of saturated fatty acids in sulfoquinovosyldiacylglycerol was sufficiently high to suggest that this lipid could undergo phase separations above 0°C. It is concluded that the content of high melting point fatty acids in leaf phosphatidylglycerol is not a direct indication of the chilling sensitivity of a plant, but rather may be a reflection of the genetic origin of that plant. PMID:16664962

Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thangirala, Mani

The Steam Turbine critical stationary structural components are high integrity Large Shell and Valve Casing heavy section Castings, containing high temperature steam under high pressures. Hence to support the development of advanced materials technology for use in an AUSC steam turbine capable of operating with steam conditions of 760°C (1400°F) and 35 Mpa (5000 psia), Casting alloy selection and evaluation of mechanical, metallurgical properties and castability with robust manufacturing methods are mandated. Alloy down select from Phase 1 based on producability criteria and creep rupture properties tested by NETL-Albany and ORNL directed the consortium to investigate cast properties of Haynesmore » 282 and Haynes 263. The goals of Task 4 in Phase 2 are to understand a broader range of mechanical properties, the impact of manufacturing variables on those properties. Scale up the size of heats to production levels to facilitate the understanding of the impact of heat and component weight, on metallurgical and mechanical behavior. GE Power & Water Materials and Processes Engineering for the Phase 2, Task 4.0 Castings work, systematically designed and executed casting material property evaluation, multiple test programs. Starting from 15 lbs. cylinder castings to world’s first 17,000 lbs. poured weight, heavy section large steam turbine partial valve Haynes 282 super alloy casting. This has demonstrated scalability of the material for steam Turbine applications. Activities under Task 4.0, Investigated and characterized various mechanical properties of Cast Haynes 282 and Cast Nimonic 263. The development stages involved were: 1) Small Cast Evaluation: 4 inch diam. Haynes 282 and Nimonic 263 Cylinders. This provided effects of liquidus super heat range and first baseline mechanical data on cast versions of conventional vacuum re-melted and forged Ni based super alloys. 2) Step block castings of 300 lbs. and 600 lbs. Haynes 282 from 2 foundry heats were evaluated which demonstrated the importance of proper heat treat cycles for Homogenization, and Solutionizing parameters selection and implementation. 3) Step blocks casting of Nimonic 263: Carried out casting solidification simulation analysis, NDT inspection methods evaluation, detailed test matrix for Chemical, Tensile, LCF, stress rupture, CVN impact, hardness and J1C Fracture toughness section sensitivity data and were reported. 4) Centrifugal Casting of Haynes 282, weighing 1400 lbs. with hybrid mold (half Graphite and half Chromite sand) mold assembly was cast using compressor casing production tooling. This test provided Mold cooling rates influence on centrifugally cast microstructure and mechanical properties. Graphite mold section out performs sand mold across all temperatures for 0.2% YS; %Elongation, %RA, UTS at 1400°F. Both Stress-LMP and conditional Fracture toughness plots data were in the scatter band of the wrought alloy. 5) Fundamental Studies on Cooling rates and SDAS test program. Evaluated the influence of 6 mold materials Silica, Chromite, Alumina, Silica with Indirect Chills, Zircon and Graphite on casting solidification cooling rates. Actual Casting cooling rates through Liquidus to Solidus phase transition were measured with 3 different locations based thermocouples placed in each mold. Compared with solidification simulation cooling rates and measurement of SDAS, microstructure features were reported. The test results provided engineered casting potential methods, applicable for heavy section Haynes 282 castings for optimal properties, with foundry process methods and tools. 6) Large casting of Haynes 282 Drawings and Engineering FEM models and supplemental requirements with applicable specifications were provided to suppliers for the steam turbine proto type feature valve casing casting. Molding, melting and casting pouring completed per approved Manufacturing Process Plan during 2014 Q4. The partial valve casing was successfully cast after casting methods were validated with solidification simulation analysis and the casting met NDT inspection and acceptance criteria. Heat treated and sectioned to extract trepan samples at different locations comparing with cast on coupons test data. Material properties requisite for design, such as tensile, creep/rupture, LCF, Fracture Toughness, Charpy V-notch chemical analysis testing were carried out. The test results will be presented in the final report. The typical Haynes 282 large size Steam Turbine production casting from Order to Delivery foundry schedule with the activity break up is shown in Figures 107 and 108. • From Purchase Order placement to Casting pouring ~ 26 weeks. 1. Sales and commercial review 3 2. Engineering Drawings/models review 4 3. Pattern and core box manufacturing 6 4. Casting process engineering review 4 5. FEM and solidification simulation analysis 4 6. Gating & Feeder Attachments, Ceramic tiling 2 7. Molding and coremaking production scheduling 6 8. Melting planning and schedule 3 9. Pouring, cooling and shake out 2 • From Pouring to casting Delivery ~ 29 weeks 10. Shot blast and riser cutting, gates removal 3 11. Homogenizing , solutionizing HT furnace prep 4 12. Grinding, Fettling 2 13. Aging HT Cycle, cooling 2 14. VT and LPT NDT inspections 2 15. Radiographic inspection 4 16. Mechanical testing, Chemical analysis test certs 4 17. Casting weld repair upgrades and Aging PWHT 4 18. NDT after weld repairs and casting upgrades 3 19. Casting Final Inspection and test certifications 3 20. Package and delivery 2 Hence the Total Lead time from P.O to Casting delivery is approximately 55 weeks. The Task 4.2 and Task 4.3 activities and reporting completed.« less

Photograph of the Month

NASA Astrophysics Data System (ADS)

2015-04-01

For dykes, magma flow direction can be deciphered from various fabrics in the chilled margin (Correa-Gomez et al., 2001, JSG 23, 1415). This photograph represents part of a chilled margin of a appr. N- S trending dyke at Kharghar Hills, Mumbai, Maharashtra, India. The section is sub-vertical. The elongated grooves indicate flow of magma through a fault and the tapered grooves (arrows) connote the flow direction: towards the pointed end of the groove. The magma flowed towards the north in this case. Such fabrics of wall-magma interaction in the Deccan volcanic province prove that dykes injected along fault planes. 19° 2‧ 22.3″ N, 73° 3‧ 28.7″ E. Photograph Ayan Achyuta Misra, Mumbai, India.

77 FR 24873 - Modernization of Poultry Slaughter Inspection

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-26

... procedures, and that, at a minimum, these procedures include microbiological testing at pre-chill and post... required to collect pre-chill and post-chill to demonstrate process control; (2) presence of visible fecal...-chill and post-chill (77 FR 4428). The proposed rule provides for testing at pre-chill and post-chill...

Casting And Solidification Technology (CAST): Directional solidification phenomena in a metal model at reduced gravity

NASA Technical Reports Server (NTRS)

Mccay, M. H.

1988-01-01

The Casting and Solidification Technology (CAST) experiment will study the phenomena that occur during directional solidification of an alloy, e.g., constitutional supercooling, freckling, and dendrite coarsening. The reduced gravity environment of space will permit the individual phenomena to be examined with minimum complication from buoyancy driven flows.

Primary arm spacing in chill block melt spun Ni-Mo alloys

NASA Technical Reports Server (NTRS)

Tewari, S. N.; Glasgow, T. K.

1986-01-01

Chill block melt spun ribbons of Ni-Mo binary alloys containing 8.0 to 41.8 wt % Mo have been prepared under carefully controlled processing conditions. The growth velocity has been determined as a function of distance from the quench surface from the observed ribbon thickness dependence on the melt puddle residence time. Primary arm spacings measured at the midribbon thickness locations show a dependence on growth velocity and alloy composition which is expected from dendritic growth models for binary alloys directionally solidified in a positive temperature gradient.

Primary arm spacing in chill block melt spun Ni-Mo alloys

NASA Technical Reports Server (NTRS)

Tewari, S. N.; Glasgow, T. K.

1987-01-01

Chill block melt spun ribbons of Ni-Mo binary alloys containing 8.0 to 41.8 wt pct Mo have been prepared under carefully controlled processing conditions. The growth velocity has been determined as a function of distance from the quench surface from the observed ribbon thickness dependence on the melt puddle residence time. Primary arm spacing measured at the midribbon thickness locations show a dependence on growth velocity and alloy composition which is expected from dendritic growth models for binary alloys directionally solidified in a positive temperature gradient.

Mg-Al-Ca In-Situ Composites with a Refined Eutectic Structure and Their Compressive Properties

NASA Astrophysics Data System (ADS)

Shi, Ling-Ling; Xu, Jian; Ma, Evan

2008-05-01

In a series of Mg x (Al2Ca)100- x (76 ≤ x ≤ 87) ternary alloys near the Mg-(Mg,Al)2Ca pseudo-binary eutectic point, different phases and morphologies based on ultrafine eutectic microstructure have been obtained by controlling the composition and changing the cooling rate via either induction melting or copper mold casting. For 81 ≤ x ≤ 87, the chill-cast alloys with ductile Mg dendrites embedded in an ultrafine [Mg + (Mg,Al)2Ca] eutectic matrix exhibit gradually increased fracture strength from 415 to 491 MPa with the decrease of Mg content. At x = 79, the Mg79Al14Ca7 alloy contains hard (Mg,Al)2Ca precipitates coexisting with ductile Mg dendrite, dispersed in the strong eutectic matrix. This alloy exhibits the highest compressive fracture strength (600 MPa), and the specific strength reaches 3.4 × 105 N·m·kg-1. The alloys all exhibit substantial plastic strain (5 to 6 pct). The attainment of such a combination of strength and plasticity is an interesting and useful step in improving the mechanical properties of lightweight Mg alloys.

The effect of evaporative air chilling and storage temperature on quality and shelf life of fresh chicken carcasses.

PubMed

Mielnik, M B; Dainty, R H; Lundby, F; Mielnik, J

1999-07-01

The effect of evaporative air chilling on quality of fresh chicken carcasses was compared with air chilling as reference method. Cooling efficiency and total heat loss were significantly higher for evaporative air chilling. The chilling method was of great importance for weight loss. Chicken chilled in cold air lost considerably more weight than chicken cooled by evaporative air chilling; the difference was 1.8%. The chilling method also affected the skin color and the amount of moisture on skin surface. After evaporative air chilling, the chicken carcasses had a lighter color and more water on the back and under the wings. The moisture content in skin and meat, cooking loss, and pH were not affected by chilling method. Odor attributes of raw chicken and odor and flavor attributes of cooked chicken did not show any significant differences between the two chilling methods. The shelf life of chicken stored at 4 and -1 C were not affected significantly by chilling method. Storage time and temperature appeared to be the decisive factors for sensory and microbiological quality of fresh chicken carcasses.

Identification of chilling and heat requirements of cherry trees--a statistical approach.

PubMed

Luedeling, Eike; Kunz, Achim; Blanke, Michael M

2013-09-01

Most trees from temperate climates require the accumulation of winter chill and subsequent heat during their dormant phase to resume growth and initiate flowering in the following spring. Global warming could reduce chill and hence hamper the cultivation of high-chill species such as cherries. Yet determining chilling and heat requirements requires large-scale controlled-forcing experiments, and estimates are thus often unavailable. Where long-term phenology datasets exist, partial least squares (PLS) regression can be used as an alternative, to determine climatic requirements statistically. Bloom dates of cherry cv. 'Schneiders späte Knorpelkirsche' trees in Klein-Altendorf, Germany, from 24 growing seasons were correlated with 11-day running means of daily mean temperature. Based on the output of the PLS regression, five candidate chilling periods ranging in length from 17 to 102 days, and one forcing phase of 66 days were delineated. Among three common chill models used to quantify chill, the Dynamic Model showed the lowest variation in chill, indicating that it may be more accurate than the Utah and Chilling Hours Models. Based on the longest candidate chilling phase with the earliest starting date, cv. 'Schneiders späte Knorpelkirsche' cherries at Bonn exhibited a chilling requirement of 68.6 ± 5.7 chill portions (or 1,375 ± 178 chilling hours or 1,410 ± 238 Utah chill units) and a heat requirement of 3,473 ± 1,236 growing degree hours. Closer investigation of the distinct chilling phases detected by PLS regression could contribute to our understanding of dormancy processes and thus help fruit and nut growers identify suitable tree cultivars for a future in which static climatic conditions can no longer be assumed. All procedures used in this study were bundled in an R package ('chillR') and are provided as Supplementary materials. The procedure was also applied to leaf emergence dates of walnut (cv. 'Payne') at Davis, California.

Identification of chilling and heat requirements of cherry trees—a statistical approach

NASA Astrophysics Data System (ADS)

Luedeling, Eike; Kunz, Achim; Blanke, Michael M.

2013-09-01

Most trees from temperate climates require the accumulation of winter chill and subsequent heat during their dormant phase to resume growth and initiate flowering in the following spring. Global warming could reduce chill and hence hamper the cultivation of high-chill species such as cherries. Yet determining chilling and heat requirements requires large-scale controlled-forcing experiments, and estimates are thus often unavailable. Where long-term phenology datasets exist, partial least squares (PLS) regression can be used as an alternative, to determine climatic requirements statistically. Bloom dates of cherry cv. `Schneiders späte Knorpelkirsche' trees in Klein-Altendorf, Germany, from 24 growing seasons were correlated with 11-day running means of daily mean temperature. Based on the output of the PLS regression, five candidate chilling periods ranging in length from 17 to 102 days, and one forcing phase of 66 days were delineated. Among three common chill models used to quantify chill, the Dynamic Model showed the lowest variation in chill, indicating that it may be more accurate than the Utah and Chilling Hours Models. Based on the longest candidate chilling phase with the earliest starting date, cv. `Schneiders späte Knorpelkirsche' cherries at Bonn exhibited a chilling requirement of 68.6 ± 5.7 chill portions (or 1,375 ± 178 chilling hours or 1,410 ± 238 Utah chill units) and a heat requirement of 3,473 ± 1,236 growing degree hours. Closer investigation of the distinct chilling phases detected by PLS regression could contribute to our understanding of dormancy processes and thus help fruit and nut growers identify suitable tree cultivars for a future in which static climatic conditions can no longer be assumed. All procedures used in this study were bundled in an R package (`chillR') and are provided as Supplementary materials. The procedure was also applied to leaf emergence dates of walnut (cv. `Payne') at Davis, California.

Facial convective heat exchange coefficients in cold and windy environments estimated from human experiments

NASA Astrophysics Data System (ADS)

Ben Shabat, Yael; Shitzer, Avraham

2012-07-01

Facial heat exchange convection coefficients were estimated from experimental data in cold and windy ambient conditions applicable to wind chill calculations. Measured facial temperature datasets, that were made available to this study, originated from 3 separate studies involving 18 male and 6 female subjects. Most of these data were for a -10°C ambient environment and wind speeds in the range of 0.2 to 6 m s-1. Additional single experiments were for -5°C, 0°C and 10°C environments and wind speeds in the same range. Convection coefficients were estimated for all these conditions by means of a numerical facial heat exchange model, applying properties of biological tissues and a typical facial diameter of 0.18 m. Estimation was performed by adjusting the guessed convection coefficients in the computed facial temperatures, while comparing them to measured data, to obtain a satisfactory fit ( r 2 > 0.98, in most cases). In one of the studies, heat flux meters were additionally used. Convection coefficients derived from these meters closely approached the estimated values for only the male subjects. They differed significantly, by about 50%, when compared to the estimated female subjects' data. Regression analysis was performed for just the -10°C ambient temperature, and the range of experimental wind speeds, due to the limited availability of data for other ambient temperatures. The regressed equation was assumed in the form of the equation underlying the "new" wind chill chart. Regressed convection coefficients, which closely duplicated the measured data, were consistently higher than those calculated by this equation, except for one single case. The estimated and currently used convection coefficients are shown to diverge exponentially from each other, as wind speed increases. This finding casts considerable doubts on the validity of the convection coefficients that are used in the computation of the "new" wind chill chart and their applicability to humans in cold and windy environments.

Facial convective heat exchange coefficients in cold and windy environments estimated from human experiments.

PubMed

Ben Shabat, Yael; Shitzer, Avraham

2012-07-01

Facial heat exchange convection coefficients were estimated from experimental data in cold and windy ambient conditions applicable to wind chill calculations. Measured facial temperature datasets, that were made available to this study, originated from 3 separate studies involving 18 male and 6 female subjects. Most of these data were for a -10°C ambient environment and wind speeds in the range of 0.2 to 6 m s(-1). Additional single experiments were for -5°C, 0°C and 10°C environments and wind speeds in the same range. Convection coefficients were estimated for all these conditions by means of a numerical facial heat exchange model, applying properties of biological tissues and a typical facial diameter of 0.18 m. Estimation was performed by adjusting the guessed convection coefficients in the computed facial temperatures, while comparing them to measured data, to obtain a satisfactory fit (r(2) > 0.98, in most cases). In one of the studies, heat flux meters were additionally used. Convection coefficients derived from these meters closely approached the estimated values for only the male subjects. They differed significantly, by about 50%, when compared to the estimated female subjects' data. Regression analysis was performed for just the -10°C ambient temperature, and the range of experimental wind speeds, due to the limited availability of data for other ambient temperatures. The regressed equation was assumed in the form of the equation underlying the "new" wind chill chart. Regressed convection coefficients, which closely duplicated the measured data, were consistently higher than those calculated by this equation, except for one single case. The estimated and currently used convection coefficients are shown to diverge exponentially from each other, as wind speed increases. This finding casts considerable doubts on the validity of the convection coefficients that are used in the computation of the "new" wind chill chart and their applicability to humans in cold and windy environments.

Proteomic Analysis of Differentially Accumulated Proteins in Cucumber (Cucumis sativus) Fruit Peel in Response to Pre-storage Cold Acclimation

PubMed Central

Wang, Bin; Shen, Fei; Zhu, Shijiang

2018-01-01

Harvested fruits are still living organs and respond to environmental stimuli. Low temperature storage is effective in extending life of harvested fruit, but it may also cause chilling injury. Cold acclimation has been shown to induce chilling tolerance in plants, but what proteomic changes caused by cold acclimation are related to defense against chilling stress remains largely unclear. Here, 3 d of pre-storage cold acclimation (PsCA) at 10°C reduced chilling injury and secondary disease severity in cucumber stored at 5°C by 51 and 94%, respectively, compared with the control which was directly stored at 5°C. Proteomic analysis of cucumber peel identified 21 significant differentially-accumulated proteins (SDAPs) right after PsCA treatment and 23 after the following cold storage (PsCA+CS). These proteins are mainly related to stress response and defense (SRD), energy metabolism, protein metabolism, signal transduction, primary metabolism, and transcription. The SRD proteins, which made up 37% of the 21 and 47% of the 23, respectively, represented the largest class of SDAPs, and all but one protein were up-regulated, suggesting accumulation of proteins involved in defense response is central feature of proteomic profile changes brought about by PsCA. In fruit just after PsCA treatment, the identified SDAPs are related to responses to various stresses, including chilling, salt stress, dehydration, fungi, bacteria, insects, and DNA damage. However, after prolonged cold storage, the targeted proteins in acclimated fruit were narrowed down in scope to those involved in defense against chilling and pathogens. The change patterns at the transcription level of the majority of the up-regulated differentially-accumulated proteins were highly consistent with those at protein level. Taken all, the results suggest that the short-time cold acclimation initiated comprehensive defense responses in cucumber fruit at first, while the long term storage thereafter altered the responses more specifically to chilling. These findings add to the understanding of plants' molecular responses to cold acclimation. PMID:29403505

Proteomic Analysis of Differentially Accumulated Proteins in Cucumber (Cucumis sativus) Fruit Peel in Response to Pre-storage Cold Acclimation.

PubMed

Wang, Bin; Shen, Fei; Zhu, Shijiang

2017-01-01

Harvested fruits are still living organs and respond to environmental stimuli. Low temperature storage is effective in extending life of harvested fruit, but it may also cause chilling injury. Cold acclimation has been shown to induce chilling tolerance in plants, but what proteomic changes caused by cold acclimation are related to defense against chilling stress remains largely unclear. Here, 3 d of pre-storage cold acclimation (PsCA) at 10°C reduced chilling injury and secondary disease severity in cucumber stored at 5°C by 51 and 94%, respectively, compared with the control which was directly stored at 5°C. Proteomic analysis of cucumber peel identified 21 significant differentially-accumulated proteins (SDAPs) right after PsCA treatment and 23 after the following cold storage (PsCA+CS). These proteins are mainly related to stress response and defense (SRD), energy metabolism, protein metabolism, signal transduction, primary metabolism, and transcription. The SRD proteins, which made up 37% of the 21 and 47% of the 23, respectively, represented the largest class of SDAPs, and all but one protein were up-regulated, suggesting accumulation of proteins involved in defense response is central feature of proteomic profile changes brought about by PsCA. In fruit just after PsCA treatment, the identified SDAPs are related to responses to various stresses, including chilling, salt stress, dehydration, fungi, bacteria, insects, and DNA damage. However, after prolonged cold storage, the targeted proteins in acclimated fruit were narrowed down in scope to those involved in defense against chilling and pathogens. The change patterns at the transcription level of the majority of the up-regulated differentially-accumulated proteins were highly consistent with those at protein level. Taken all, the results suggest that the short-time cold acclimation initiated comprehensive defense responses in cucumber fruit at first, while the long term storage thereafter altered the responses more specifically to chilling. These findings add to the understanding of plants' molecular responses to cold acclimation.

Microstructural evolution during the homogenization heat treatment of 6XXX and 7XXX aluminum alloys

NASA Astrophysics Data System (ADS)

Priya, Pikee

Homogenization heat treatment of as-cast billets is an important step in the processing of aluminum extrusions. Microstructural evolution during homogenization involves elimination of the eutectic morphology by spheroidisation of the interdendritic phases, minimization of the microsegregation across the grains through diffusion, dissolution of the low-melting phases, which enhances the surface finish of the extrusions, and precipitation of nano-sized dispersoids (for Cr-, Zr-, Mn-, Sc-containing alloys), which inhibit grain boundary motion to prevent recrystallization. Post-homogenization cooling reprecipitates some of the phases, changing the flow stress required for subsequent extrusion. These precipitates, however, are deleterious for the mechanical properties of the alloy and also hamper the age-hardenability and are hence dissolved during solution heat treatment. Microstructural development during homogenization and subsequent cooling occurs both at the length scale of the Secondary Dendrite Arm Spacing (SDAS) in micrometers and dispersoids in nanometers. Numerical tools to simulate microstructural development at both the length scales have been developed and validated against experiments. These tools provide easy and convenient means to study the process. A Cellular Automaton-Finite Volume-based model for evolution of interdendritic phases is coupled with a Particle Size Distribution-based model for precipitation of dispersoids across the grain. This comprehensive model has been used to study the effect of temperature, composition, as-cast microstructure, and cooling rates during post-homogenization quenching on microstructural evolution. The numerical study has been complimented with experiments involving Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-Ray Diffraction and Differential Scanning Calorimetry and a good agreement has with numerical results has been found. The current work aims to study the microstructural evolution during homogenization heat treatment at both length scales which include the (i) dissolution and transformation of the as-cast secondary phases; (ii) precipitation of dispersoids; and (iii) reprecipitation of some of the secondary phases during post-homogenization cooling. The kinetics of the phase transformations are mostly diffusion controlled except for the eta to S phase transformation in 7XXX alloys which is interface reaction rate controlled which has been implemented using a novel approach. Recommendations for homogenization temperature, time, cooling rates and compositions are made for Al-Si-Mg-Fe-Mn and Al-Zn-Cu-Mg-Zr alloys. The numerical model developed has been applied for a through process solidification-homogenization modeling of a Direct-Chill cast AA7050 cylindrical billet to study the radial variation of microstructure after solidification, homogenization and post-homogenization cooling.

Involvement of Polyamines in the Chilling Tolerance of Cucumber Cultivars

PubMed Central

Shen, Wenyun; Nada, Kazuyoshi; Tachibana, Shoji

2000-01-01

The possible involvement of polyamines (PAs) in the chilling tolerance of cucumber (Cucumis sativus L. cv Jinchun No. 3 and cv Suyo) was investigated. Plants with the first expanded leaves were exposed to 3°C or 15°C in the dark for 24 h (chilling), and then transferred to 28°C/22°C under a 12-h photoperiod for another 24 h (rewarming). Chilling-tolerant cv Jinchun No. 3 showed a marked increase of free spermidine (Spd) in leaves, once during chilling and again during rewarming. Putrescine increased significantly during rewarming, but the increase of spermine was slight. Any of these PAs did not increase in chilling-sensitive cv Suyo during either period. PA-biosynthetic enzyme activities appear to mediate these differences between cultivars. Pretreatment of Spd to cv Suyo prevented chill-induced increases in the contents of hydrogen peroxide in leaves and activities of NADPH oxidases and NADPH-dependent superoxide generation in microsomes and alleviated chilling injury. Pretreatment of methylglyoxal-bis-(guanylhydrazone), a PA biosynthesis inhibitor, to chilled cv Jinchun No. 3 prevented Spd increase and enhanced microsomal NADPH oxidase activity and chilling injury. The results suggest that Spd plays important roles in chilling tolerance of cucumber, probably through prevention of chill-induced activation of NADPH oxidases in microsomes. PMID:10982456

External tank chill effect on the space transportation system launch pad environment

NASA Technical Reports Server (NTRS)

Ahmad, R. A.; Boraas, S.

1991-01-01

The external tank (ET) of the STS contains liquid oxygen and liquid hydrogen as oxidizer and fuel for the SSMEs. Once the cryogen have been loaded into the ET, the temperature of the air surrounding the STS is chilled by the cold outer surface of the ET. This paper describes a two-dimensional flow and thermal analysis to determine this chill effect on the STS launch pad environment subsequent to the ET loading operation. The analysis was done assuming winter conditions and a northwest wind direction. An existing CFD code, PHOENICS '81, was used in the study. The results are presented as local and average values of the heat transfer coefficient, the Nusselt number, and the surface temperature around the redesigned solid rocket motors (RSRMs) and the ET. The temperature depression caused by the ET chilling of the air in the vicinity of the RSRMs was calculated to be 3 F below the ambient. This compares with the observed 1-2 F RSRM surface temperature depression based upon measurements made prior to the winter flight of STS-29. Since the surface temperature would be expected to be slightly higher than the local air temperature, the predicted temperature depression of the air appears to be substantiated.

Comparative transcriptome and lipidome analyses reveal molecular systems underlying chilling response in chilling-tolerant sorghums

USDA-ARS?s Scientific Manuscript database

Chilling temperatures are a major constraint for temperate cultivation of tropical-origin crops, including the cereal crop sorghum (Sorghum bicolor [L.] Moench). Northern Chinese sorghums have adapted to early-season chilling, but molecular mechanisms of chilling tolerance are unknown. We used RNA ...

Basic Casting from A to Z. Student's Instruction Booklet.

ERIC Educational Resources Information Center

Zebco, Tulsa, OK.

A profusely illustrated student instruction booklet contains step-by-step directions and diagrams for learning four basic casting techniques. Separate sections cover basic spin-casting, spinning, bait-casting, and fly-casting. Each section details recommended equipment (reel, rod, line, plug, tackle, lures, leaders, flies), describes specific…

Climatic changes lead to declining winter chill for fruit and nut trees in California during 1950-2099.

PubMed

Luedeling, Eike; Zhang, Minghua; Girvetz, Evan H

2009-07-16

Winter chill is one of the defining characteristics of a location's suitability for the production of many tree crops. We mapped and investigated observed historic and projected future changes in winter chill in California, quantified with two different chilling models (Chilling Hours, Dynamic Model). Based on hourly and daily temperature records, winter chill was modeled for two past temperature scenarios (1950 and 2000), and 18 future scenarios (average conditions during 2041-2060 and 2080-2099 under each of the B1, A1B and A2 IPCC greenhouse gas emissions scenarios, for the CSIRO-MK3, HadCM3 and MIROC climate models). For each scenario, 100 replications of the yearly temperature record were produced, using a stochastic weather generator. We then introduced and mapped a novel climatic statistic, "safe winter chill", the 10% quantile of the resulting chilling distributions. This metric can be interpreted as the amount of chilling that growers can safely expect under each scenario. Winter chill declined substantially for all emissions scenarios, with the area of safe winter chill for many tree species or cultivars decreasing 50-75% by mid-21st century, and 90-100% by late century. Both chilling models consistently projected climatic conditions by the middle to end of the 21st century that will no longer support some of the main tree crops currently grown in California, with the Chilling Hours Model projecting greater changes than the Dynamic Model. The tree crop industry in California will likely need to develop agricultural adaptation measures (e.g. low-chill varieties and dormancy-breaking chemicals) to cope with these projected changes. For some crops, production might no longer be possible.

The effects of novel surface treatments on the wear and fatigue properties of steel and chilled cast iron

NASA Astrophysics Data System (ADS)

Carroll, Jason William

Contact fatigue driven wear is a principal design concern for gear and camshaft engineering of power systems. To better understand how to engineer contact fatigue resistant surfaces, the effects of electroless nickel and hydrogenated diamond-like-carbon (DLC) coatings on the fatigue life at 108 cycles of SAE 52100 steel were studied using ultrasonic fatigue methods. The addition of DLC and electroless nickel coatings to SAE 52100 bearing steel had no effect on the fatigue life. Different inclusion types were found to affect the stress intensity value beyond just the inclusion size, as theorized by Murakami. The difference in stress intensity values necessary to propagate a crack for Ti (C,N) and alumina inclusions was due to the higher driving force for crack extension at the Ti (C,N) inclusions and was attributed to differences in the shape of the inclusion: rhombohedral for the Ti (C,N) versus spherical for the oxides. A correction factor was added to the Murakami equation to account for inclusion type. The wear properties of DLC coated SAE 52100 and chilled cast iron were studied using pin-on-disk tribometry and very high cycle ultrasonic tribometry. A wear model that includes sliding thermal effects as well as thermodynamics consistent with the wear mechanism for DLCs was developed based on empirical results from ultrasonic wear testing to 108 cycles. The model fit both ultrasonic and classic tribometer data for wear of DLCs. Finally, the wear properties of laser hardened steels - SAE 8620, 4140, and 52100 - were studied at high contact pressures and low numbers of cycles. A design of experiments was conducted to understand how the laser processing parameters of power, speed, and beam size, as well as carbon content of the steel, affected surface hardness. A hardness maximum was found at approximately 0.7 wt% carbon most likely resulting from increased amounts of retained austenite. The ratcheting contact fatigue model of Kapoor was found to be useful in predicting the wear results. The empirical model of Clayton and Su and extended by Afferente and Ciavarella, also provided reasonable semi-quantitative contact fatigue life models for these steels.

76 FR 40402 - Matthews International Corporation, Bronze Division, Kingwood, WV; Notice of Negative...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-08

... the Federal Register on February 10, 2011 (76 FR 7584). Workers were engaged in the production of cast... their purchases of cast bronze memorial products (and like or directly competitive articles) in 2007... Department determines that imports of articles like or directly competitive with the cast bronze memorial...

Redox Signaling and CBF-Responsive Pathway Are Involved in Salicylic Acid-Improved Photosynthesis and Growth under Chilling Stress in Watermelon

PubMed Central

Cheng, Fei; Lu, Junyang; Gao, Min; Shi, Kai; Kong, Qiusheng; Huang, Yuan; Bie, Zhilong

2016-01-01

Salicylic acid (SA) plays an important role in plant response to abiotic stresses. This study investigated the potential role of SA in alleviating the adverse effects of chilling stress on photosynthesis and growth in watermelon (Citrullus lanatus). Chilling stress induced the simultaneous accumulation of free and conjugated SA in watermelon plants, and the chilling-induced SA production was attributed to the phenylalanine ammonia-lyase pathway. Applying SA at moderate concentrations induced chilling tolerance, whereas inhibition of SA biosynthesis by L-α-aminooxy-β-phenylpropionic acid (AOPP) increased the photooxidation of PS II under chilling stress in watermelon, resulting in reduced photosynthesis and growth. Chilling induced a transient increase in the ratios of reduced to oxidized glutathione and reduced ascorbate to dehydroascorbate. Then, the expression of antioxidant genes was upregulated, and the activities of antioxidant enzymes were enhanced. Furthermore, SA-induced chilling tolerance was associated with cellular glutathione and ascorbate homeostasis, which served as redox signals to regulate antioxidant metabolism under chilling stress. AOPP treatment stimulated the chilling-induced expression of cold-responsive genes, particularly via C-repeat binding factors CBF3 and CBF4. These results confirm the synergistic role of SA signaling and the CBF-dependent responsive pathway during chilling stress in watermelon. PMID:27777580

Boron nutrition and chilling tolerance of warm climate crop species.

PubMed

Huang, Longbin; Ye, Zhengqian; Bell, Richard W; Dell, Bernard

2005-10-01

Field observations and glasshouse studies have suggested links between boron (B)-deficiency and leaf damage induced by low temperature in crop plants, but causal relationships between these two stresses at physiological, biochemical and molecular levels have yet to be explored. Limited evidence at the whole-plant level suggests that chilling temperature in the root zone restricts B uptake capacity and/or B distribution/utilization efficiency in the shoot, but the nature of this interaction depends on chilling tolerance of species concerned, the mode of low temperature treatment (abrupt versus gradual temperature decline) and growth conditions (e.g. photon flux density and relative humidity) that may exacerbate chilling stress. This review explores roles of B nutrition in chilling tolerance of continual root or transient shoot chills in crop species adapted to warm season conditions. It reviews current research on combined effects of chilling temperature (ranging from >0 to 20 degrees C) and B deficiency on growth and B nutrition responses in crop species differing in chilling tolerance. For subtropical/tropical species (e.g. cucumber, cassava, sunflower), root chilling at 10-17 degrees C decreases B uptake efficiency and B utilization in the shoot and increases the shoot : root ratio, but chilling-tolerant temperate species (e.g. oilseed rape, wheat) require much lower root chill temperatures (2-5 degrees C) to achieve the same responses. Boron deficiency exacerbates chilling injuries in leaf tissues, particularly under high photon flux density. Suggested mechanisms for B x chilling interactions in plants are: (a) chilling-induced reduction in plasmalemma hydraulic conductivity, membrane fluidity, water channel activity and root pressure, which contribute to the decrease in root hydraulic conductance, water uptake and associated B uptake; (b) chilling-induced stomatal dysfunction affecting B transport from root to shoot and B partitioning in the shoot; and (c) B deficiency induced sensitivity to photo-oxidative damage in leaf cells. However, specific evidence for each of the mechanisms is still lacking. Impacts of B status on chilling tolerance in crop species have important implications for the management of B supply during sensitive stages of growth, such as early growth after planting and early reproductive development, both of which can coincide with the occurrence of chilling temperatures in the field.

Effect of dry-air chilling on sensory descriptive profiles of cooked broiler breast meat deboned four hours after the initiation of chilling

USDA-ARS?s Scientific Manuscript database

Air chilled chicken products are gaining popularity in the USA. It has been claimed that air chilling (AC) results in improved tenderness and flavor of broiler meat compared with immersion chilling (IC). However, there is a lack of published sensory study results to support the claims. The objecti...

Regulation of respiration and the oxygen diffusion barrier in soybean protect symbiotic nitrogen fixation from chilling-induced inhibition and shoots from premature senescence.

PubMed

van Heerden, Philippus D R; Kiddle, Guy; Pellny, Till K; Mokwala, Phatlane W; Jordaan, Anine; Strauss, Abram J; de Beer, Misha; Schlüter, Urte; Kunert, Karl J; Foyer, Christine H

2008-09-01

Symbiotic nitrogen fixation is sensitive to dark chilling (7 degrees C-15 degrees C)-induced inhibition in soybean (Glycine max). To characterize the mechanisms that cause the stress-induced loss of nodule function, we examined nodule structure, carbon-nitrogen interactions, and respiration in two soybean genotypes that differ in chilling sensitivity: PAN809 (PAN), which is chilling sensitive, and Highveld Top (HT), which is more chilling resistant. Nodule numbers were unaffected by dark chilling, as was the abundance of the nitrogenase and leghemoglobin proteins. However, dark chilling decreased nodule respiration rates, nitrogenase activities, and NifH and NifK mRNAs and increased nodule starch, sucrose, and glucose in both genotypes. Ureide and fructose contents decreased only in PAN nodules. While the chilling-induced decreases in nodule respiration persisted in PAN even after return to optimal temperatures, respiration started to recover in HT by the end of the chilling period. The area of the intercellular spaces in the nodule cortex and infected zone was greatly decreased in HT after three nights of chilling, an acclimatory response that was absent from PAN. These data show that HT nodules are able to regulate both respiration and the area of the intercellular spaces during chilling and in this way control the oxygen diffusion barrier, which is a key component of the nodule stress response. We conclude that chilling-induced loss of symbiotic nitrogen fixation in PAN is caused by the inhibition of respiration coupled to the failure to regulate the oxygen diffusion barrier effectively. The resultant limitations on nitrogen availability contribute to the greater chilling-induced inhibition of photosynthesis in PAN than in HT.

Regulation of Respiration and the Oxygen Diffusion Barrier in Soybean Protect Symbiotic Nitrogen Fixation from Chilling-Induced Inhibition and Shoots from Premature Senescence1[W][OA

PubMed Central

van Heerden, Philippus D.R.; Kiddle, Guy; Pellny, Till K.; Mokwala, Phatlane W.; Jordaan, Anine; Strauss, Abram J.; de Beer, Misha; Schlüter, Urte; Kunert, Karl J.; Foyer, Christine H.

2008-01-01

Symbiotic nitrogen fixation is sensitive to dark chilling (7°C–15°C)-induced inhibition in soybean (Glycine max). To characterize the mechanisms that cause the stress-induced loss of nodule function, we examined nodule structure, carbon-nitrogen interactions, and respiration in two soybean genotypes that differ in chilling sensitivity: PAN809 (PAN), which is chilling sensitive, and Highveld Top (HT), which is more chilling resistant. Nodule numbers were unaffected by dark chilling, as was the abundance of the nitrogenase and leghemoglobin proteins. However, dark chilling decreased nodule respiration rates, nitrogenase activities, and NifH and NifK mRNAs and increased nodule starch, sucrose, and glucose in both genotypes. Ureide and fructose contents decreased only in PAN nodules. While the chilling-induced decreases in nodule respiration persisted in PAN even after return to optimal temperatures, respiration started to recover in HT by the end of the chilling period. The area of the intercellular spaces in the nodule cortex and infected zone was greatly decreased in HT after three nights of chilling, an acclimatory response that was absent from PAN. These data show that HT nodules are able to regulate both respiration and the area of the intercellular spaces during chilling and in this way control the oxygen diffusion barrier, which is a key component of the nodule stress response. We conclude that chilling-induced loss of symbiotic nitrogen fixation in PAN is caused by the inhibition of respiration coupled to the failure to regulate the oxygen diffusion barrier effectively. The resultant limitations on nitrogen availability contribute to the greater chilling-induced inhibition of photosynthesis in PAN than in HT. PMID:18667725

The effects of different chilling methods on meat quality and calpain activity of pork muscle longissimus dorsi.

PubMed

Xu, Yang; Huang, Ji-Chao; Huang, Ming; Xu, Bao-Cai; Zhou, Guang-Hong

2012-01-01

The objective of this study was to investigate the effects of conventional chilling (0 to 4 °C), rapid chilling (RC, -20 °C for 30 min, followed by 0 to 4 °C), and short-duration chilling (0 to 4 °C for 30 min, followed by 25 °C) on meat quality and calpain activity of pork muscle longissimus dorsi (LD). The muscle quality characteristics pH, color, cooking loss, pressing loss and tenderness, and calpain activities were measured 0-, 3-, 12-, and 24-h postmortem. Results show that the RC resulted in a faster temperature decline of the muscle, and prevented the meat pH and Commission Internationale de l'Eclairage L* value from declining during postmortem aging. RC also reduced meat cooking loss and pressing loss compared with the other two chilling methods. However, the chilling methods did not significantly affect meat shear force. During the first 24-h postmortem, there was not a noticeable change in the activity of m-calpain. But μ-calpain activity decreased regardless of chilling method. In the rapidly chilled carcasses, μ-calpain activity remained the same 3- and 12-h postmortem. However, in the short-duration chilled and conventionally chilled carcasses, the activity was visibly reduced. At 24-h postmortem, no clear zones on the gel were observed in all three treatments. Conventional and RC methods are commonly used for pork in commercial practice nowadays. Compared with conventional chilling, the effect of RC on quality parameters of pork varies. In recent years, short-duration chilling (SC) is widely used in many Chinese pig slaughtering facilities. However, few researchers have studied the effect of SD on pork quality. Therefore, the present study investigated the effect of different chilling methods on functionalities or quality of chilled pork meat. © 2011 Institute of Food Technologists®

Tradeoffs between chilling and forcing in satisfying dormancy requirements for Pacific Northwest tree species

PubMed Central

Harrington, Constance A.; Gould, Peter J.

2015-01-01

Many temperate and boreal tree species have a chilling requirement, that is, they need to experience cold temperatures during fall and winter to burst bud normally in the spring. Results from trials with 11 Pacific Northwest tree species are consistent with the concept that plants can accumulate both chilling and forcing units simultaneously during the dormant season and they exhibit a tradeoff between amount of forcing and chilling. That is, the parallel model of chilling and forcing was effective in predicting budburst and well chilled plants require less forcing for bud burst than plants which have received less chilling. Genotypes differed in the shape of the possibility line which describes the quantitative tradeoff between chilling and forcing units. Plants which have an obligate chilling requirement (Douglas-fir, western hemlock, western larch, pines, and true firs) and received no or very low levels of chilling did not burst bud normally even with long photoperiods. Pacific madrone and western redcedar benefited from chilling in terms of requiring less forcing to promote bud burst but many plants burst bud normally without chilling. Equations predicting budburst were developed for each species in our trials for a portion of western North America under current climatic conditions and for 2080. Mean winter temperature was predicted to increase 3.2–5.5°C and this change resulted in earlier predicted budburst for Douglas-fir throughout much of our study area (up to 74 days earlier) but later budburst in some southern portions of its current range (up to 48 days later) as insufficient chilling is predicted to occur. Other species all had earlier predicted dates of budburst by 2080 than currently. Recent warming trends have resulted in earlier budburst for some woody plant species; however, the substantial winter warming predicted by some climate models will reduce future chilling in some locations such that budburst will not consistently occur earlier. PMID:25784922

Water Status Related Root-to-Shoot Communication Regulates the Chilling Tolerance of Shoot in Cucumber (Cucumis sativus L.) Plants.

PubMed

Zhang, Zi-Shan; Liu, Mei-Jun; Gao, Hui-Yuan; Jin, Li-Qiao; Li, Yu-Ting; Li, Qing-Ming; Ai, Xi-Zhen

2015-10-16

Although root-to-shoot communication has been intensively investigated in plants under drought, few studies have examined root-to-shoot communication under chilling. Here we explored whether root-to-shoot communication contributes to the chilling-light tolerance of cucumber shoots and clarified the key signal involves in this communication. After leaf discs chilling-light treatment, the photoinhibitions of Photosystem I (PSI) and Photosystem II (PSII) were similar in leaf discs of two cucumber varieties (JY-3 and JC-4). When the whole plants, including roots, were chilled under light, the photosynthetic performances in JC-4 leaves decreased more seriously than that in JY-3 leaves. However, when the water status of leaves was maintained by warming roots or floating the attached leaves on water, the PSII activity and amount of PSI in the leaves of the two varieties were similar after chilling-light treatment. In addition, the differences of PSII activities and amount of PSI between the two varieties under whole plant chilling-light treatment were independent of ABA pretreatment. Above results indicate that (1) the better water status in leaves under chilling contributes to the higher chilling tolerance of JY-3; (2) the water status, rather than an ABA signal, dominates root-to-shoot communication under chilling and the chilling tolerance of cucumber shoot.

Very High Cycle Fatigue Behavior of a Directionally Solidified Ni-Base Superalloy DZ4

PubMed Central

Nie, Baohua; Zhao, Zihua; Liu, Shu; Chen, Dongchu; Ouyang, Yongzhong; Hu, Zhudong; Fan, Touwen; Sun, Haibo

2018-01-01

The effect of casting pores on the very high cycle fatigue (VHCF) behavior of a directionally solidified (DS) Ni-base superalloy DZ4 is investigated. Casting and hot isostatic pressing (HIP) specimens were subjected to very high cycle fatigue loading in an ambient atmosphere. The results demonstrated that the continuously descending S-N curves were exhibited for both the casting and HIP specimens. Due to the elimination of the casting pores, the HIP samples had better fatigue properties than the casting samples. The subsurface crack initiated from the casting pore in the casting specimens at low stress amplitudes, whereas fatigue crack initiated from crystallographic facet decohesion for the HIP specimens. When considering the casting pores as initial cracks, there exists a critical stress intensity threshold ranged from 1.1 to 1.3 MPam, below which fatigue cracks may not initiate from the casting pores. Furthermore, the effect of the casting pores on the fatigue limit is estimated based on a modified El Haddad model, which is in good agreement with the experimental results. Fatigue life for both the casting and HIP specimens is well predicted using the Fatigue Indicator Parameter (FIP) model. PMID:29320429

Effect of Copper and Zirconium Addition on Properties of Fe-Co-Si-B-Nb Bulk Metallic Glasses

NASA Astrophysics Data System (ADS)

Ikram, Haris; Khalid, Fazal Ahmad; Akmal, Muhammad; Abbas, Zameer

2017-07-01

In this research work, iron-based bulk metallic glasses (BMGs) have been fabricated, characterized and compared with Fe-Si alloy. BMG alloys of composition ((Fe0.6Co0.4)0.75B0.20Si0.05)96Nb4) were synthesized by suction casting technique using chilled copper die. Effect of copper and zirconium addition on magnetic, mechanical, thermal and electrochemical behavior of ((Fe0.6Co0.4)0.75B0.20Si0.05)96Nb4 BMGs was investigated. Furthermore, effect of annealing on nano-crystallization and subsequently on magnetic and mechanical behavior was also analyzed. Amorphousness of structure was evidenced by XRD analysis and microscopic visualization, whereas nano-crystallization behavior was identified by peak broadening of XRD patterns. Magnetic properties, measured by vibrating sample magnetometer, were found to be improved for as-cast BMG alloys by copper addition and further enhanced by nano-crystallization after annealing. Mechanical properties were observed to be increased by zirconium addition while slightly declined by copper addition. Potentiodynamic polarization analysis manifested the positive role of zirconium in enhancing corrosion resistance of BMGs in acidic, basic and brine mediums. Moreover, mechanical properties and corrosion analysis results affirmed the superiority of BMG alloys over Fe-Si alloy.

Terral De Vicuna, a Foehnlike Wind in Semiarid Northern Chile: Meteorological Aspects and Implications for the Fulfillment of Chill Requirements in Deciduous Fruit Trees

NASA Technical Reports Server (NTRS)

Montes, Carlo; Rutllant, Jose A.; Aguirre, Anita; Bascunan-Godoy, Luisa; Julia, Cristobal

2016-01-01

The terral de Vicuña is a warm and dry wind that flows down the Elqui Valley in north-central Chile typically at dawn and early morning. Given that most terral episodes occur in austral winter when chill accumulation by deciduous fruit trees proceeds, negative effects on agriculture may be expected. During 11 (2004-14) winters a meteorological characterization of terral winds and the assessment of their impact on chill accumulation, by the modified Utah Model and the Dynamic Model, were performed. Within this period, 67 terral days (TD) were identified as those in which nighttime to early morning wind direction and speed, air temperature, and relative humidity reached defined thresholds on an hourly basis (terral hours). Most frequent TD featured 6-9 consecutive terral hours; duration is considered here as a proxy for their intensity. Synoptic-scale meteorological analysis shows that 65% of moderate and strong terral events develop as a cold, migratory anticyclone drifts poleward of the study area, coinciding with the onset of a midtropospheric ridge over central Chile, bringing southwest winds on top of the Andes (approximately 500-hPa level). The remaining 35% are either associated with 500-hPa easterlies (foehn like), with prefrontal conditions ahead of a trough driving northwest 500-hPa winds, or with transitional 500-hPa westerlies.Assessments of chill accumulation during TD show that, although present average and cold winter conditions do not represent a major TD hazard to local agriculture, lower chill accumulation associated with anomalously high nocturnal temperatures could be significantly more important during present and future warmer winters.

Innovative forming and fabrication technologies : new opportunities.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, B.; Hryn, J.; Energy Systems

2008-01-31

The advent of light metal alloys and advanced materials (polymer, composites, etc.) have brought the possibility of achieving important energy reductions into the full life cycle of these materials, especially in transportation applications. 1 These materials have gained acceptance in the aerospace industry but use of light metal alloys needs to gain wider acceptance in other commercial transportation areas. Among the main reasons for the relatively low use of these materials are the lack of manufacturability, insufficient mechanical properties, and increased material costs due to processing inefficiencies. Considering the enormous potential energy savings associated with the use of light metalmore » alloys and advanced materials in transportation, there is a need to identify R&D opportunities in the fields of materials fabrication and forming aimed at developing materials with high specific mechanical properties combined with energy efficient processes and good manufacturability. This report presents a literature review of the most recent developments in the areas of fabrication and metal forming focusing principally on aluminum alloys. In the first section of the document, the different sheet manufacturing technologies including direct chill (DC) casting and rolling, spray forming, spray rolling, thin slab, and strip casting are reviewed. The second section of the document presents recent research on advanced forming processes. The various forming processes reviewed are: superplastic forming, electromagnetic forming, age forming, warm forming, hydroforming, and incremental forming. Optimization of conventional forming processes is also discussed. Potentially interesting light metal alloys for high structural efficiency including aluminum-scandium, aluminum-lithium, magnesium, titanium, and amorphous metal alloys are also reviewed. This section concludes with a discussion on alloy development for manufacturability. The third section of the document reviews the latest developments in fiber-reinforced composite materials. Emerging curing processes are presented along with a discussion on the possible developments in biocomposite materials. The fourth section presents recent developments in the fabrication of bulk nanomaterials and nanoparticles reinforced materials. Advanced joining technologies are presented in the fifth section. Future research is proposed in the last section.« less

Direct Cast U-6Nb – 2017 Progress on Cylindrical Castings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aikin, Jr., Robert M.

2017-10-04

This report describes work to further develop a sound technical basis and best practices for mold design and process parameters for the Direct Casting of U-6wt%Nb components. One major challenge to the production of U-6Nb components is the propensity for niobium segregation during casting and solidification. This is especially true for cylindrical castings where the vertical side walls allow flotation of Nb resulting in severe inverse macrosegregation. In this work, a small (120 mm diameter by 180 mm tall) and large cylinder (250 mm diameter by 310 mm tall) are examined with a focus on reducing, or eliminating, niobium segregation.more » It is demonstrated that counter gravity casting (top-to-bottom solidification) can be used to minimize segregation in the small cylinder. Attempts to counter gravity cast the large cylinder were unsuccessful, in large part due to size limitations of the current furnace. A path forward for casting of the large cylinders is discussed.« less

Development of High-Performance Cast Crankshafts. Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bauer, Mark E

The objective of this project was to develop technologies that would enable the production of cast crankshafts that can replace high performance forged steel crankshafts. To achieve this, the Ultimate Tensile Strength (UTS) of the new material needs to be 850 MPa with a desired minimum Yield Strength (YS; 0.2% offset) of 615 MPa and at least 10% elongation. Perhaps more challenging, the cast material needs to be able to achieve sufficient local fatigue properties to satisfy the durability requirements in today’s high performance gasoline and diesel engine applications. The project team focused on the development of cast steel alloysmore » for application in crankshafts to take advantage of the higher stiffness over other potential material choices. The material and process developed should be able to produce high-performance crankshafts at no more than 110% of the cost of current production cast units, perhaps the most difficult objective to achieve. To minimize costs, the primary alloy design strategy was to design compositions that can achieve the required properties with minimal alloying and post-casting heat treatments. An Integrated Computational Materials Engineering (ICME) based approach was utilized, rather than relying only on traditional trial-and-error methods, which has been proven to accelerate alloy development time. Prototype melt chemistries designed using ICME were cast as test specimens and characterized iteratively to develop an alloy design within a stage-gate process. Standard characterization and material testing was done to validate the alloy performance against design targets and provide feedback to material design and manufacturing process models. Finally, the project called for Caterpillar and General Motors (GM) to develop optimized crankshaft designs using the final material and manufacturing processing path developed. A multi-disciplinary effort was to integrate finite element analyses by engine designers and geometry-specific casting simulations with existing materials models to optimize crankshaft cost and performance. Prototype crankshafts of the final design were to be produced and validated using laboratory bench testing and on-engine durability testing. ICME process simulation tools were used to investigate a broad range of processing concepts. These concepts included casting orientation, various mold and core materials, and various filling and feeding strategies. Each crankshaft was first simulated without gating and risers, which is termed natural solidification. The natural solidification results were used as a baseline for strategy development of each concept. Casting process simulations and ICME tools were proven to be reasonable predictors of real world results. Potential alloys were developed that could meet the project material property goals with appropriate normalization and temper treatments. For the alloys considered, post-normalization temper treatments proved to be necessary to achieve the desired yield strengths and elongations and appropriate heat treatments were designed using ICME tools. The experimental data of all the alloys were analyzed in combination with ICME tools to establish chemistry-process-structure relations. Several GM small gas engine (SGE) crankshafts were successfully cast in sand molds using two different sprue, runner, gate, riser, chill designs. These crankshafts were cast in two different steel alloys developed during the project, but casting finishing (e.g. riser removal) remains a cost challenge. A long list of future work was left unfinished when this project was unexpectedly terminated.« less

Contrasting effect of dark-chilling on chloroplast structure and arrangement of chlorophyll-protein complexes in pea and tomato: plants with a different susceptibility to non-freezing temperature.

PubMed

Garstka, Maciej; Venema, Jan Henk; Rumak, Izabela; Gieczewska, Katarzyna; Rosiak, Malgorzata; Koziol-Lipinska, Joanna; Kierdaszuk, Borys; Vredenberg, Wim J; Mostowska, Agnieszka

2007-10-01

The effect of dark-chilling and subsequent photoactivation on chloroplast structure and arrangements of chlorophyll-protein complexes in thylakoid membranes was studied in chilling-tolerant (CT) pea and in chilling-sensitive (CS) tomato. Dark-chilling did not influence chlorophyll content and Chl a/b ratio in thylakoids of both species. A decline of Chl a fluorescence intensity and an increase of the ratio of fluorescence intensities of PSI and PSII at 120 K was observed after dark-chilling in thylakoids isolated from tomato, but not from pea leaves. Chilling of pea leaves induced an increase of the relative contribution of LHCII and PSII fluorescence. A substantial decrease of the LHCII/PSII fluorescence accompanied by an increase of that from LHCI/PSI was observed in thylakoids from chilled tomato leaves; both were attenuated by photoactivation. Chlorophyll fluorescence of bright grana discs in chloroplasts from dark-chilled leaves, detected by confocal laser scanning microscopy, was more condensed in pea but significantly dispersed in tomato, compared with control samples. The chloroplast images from transmission-electron microscopy revealed that dark-chilling induced an increase of the degree of grana stacking only in pea chloroplasts. Analyses of O-J-D-I-P fluorescence induction curves in leaves of CS tomato before and after recovery from chilling indicate changes in electron transport rates at acceptor- and donor side of PS II and an increase in antenna size. In CT pea leaves these effects were absent, except for a small but irreversible effect on PSII activity and antenna size. Thus, the differences in chloroplast structure between CS and CT plants, induced by dark-chilling are a consequence of different thylakoid supercomplexes rearrangements.

40 CFR 421.1 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... to alloying or casting of nonferrous metals is limited to alloying or casting of hot metal directly... cooling is included in the aluminum forming, nonferrous metals forming, or metal molding and casting point...

Enumeration of Escherichia coli in swab samples from pre- and post-chilled pork and lamb carcasses using 3M™ Petrifilm™ Select E. coli and Simplate® Coliforms/E. coli.

PubMed

Hauge, Sigrun J; Østensvik, Øyvin; Monshaugen, Marte; Røtterud, Ole-Johan; Nesbakken, Truls; Alvseike, Ole

2017-08-01

The aim of the study was to compare two analytical methods; 3M Petrifilm™ Select E. coli and SimPlate® Coliforms &E. coli, for detection and enumeration of E. coli using swab samples from naturally contaminated pork and lamb carcasses that were collected before and after chilling. Blast chilling was used for pork carcasses. Swab samples (n=180) were collected from 60 warm and 60 chilled pork carcasses, and 30 warm and 30 chilled lamb carcasses, and analysed in parallel. The concordance correlation coefficient between Petrifilm and SimPlate was 0.89 for pork and 0.81 for lamb carcasses. However, the correlation was higher for warm carcasses (0.90) than chilled carcasses (0.72). For chilled lamb carcasses, the correlation was only 0.50, and SimPlate gave slightly higher results than Petrifilm (P=0.09). Slower chilling gave slightly lesser agreement between methods than for blast chilling, however, both Petrifilm and SimPlate methodologies are suitable and recommended for use in small laboratories in abattoirs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chilling Affects Phytohormone and Post-Embryonic Development Pathways during Bud Break and Fruit Set in Apple (Malus domestica Borkh.)

PubMed Central

Kumar, Gulshan; Gupta, Khushboo; Pathania, Shivalika; Swarnkar, Mohit Kumar; Rattan, Usha Kumari; Singh, Gagandeep; Sharma, Ram Kumar; Singh, Anil Kumar

2017-01-01

The availability of sufficient chilling during bud dormancy plays an important role in the subsequent yield and quality of apple fruit, whereas, insufficient chilling availability negatively impacts the apple production. The transcriptome profiling during bud dormancy release and initial fruit set under low and high chill conditions was performed using RNA-seq. The comparative high number of differentially expressed genes during bud break and fruit set under high chill condition indicates that chilling availability was associated with transcriptional reorganization. The comparative analysis reveals the differential expression of genes involved in phytohormone metabolism, particularly for Abscisic acid, gibberellic acid, ethylene, auxin and cytokinin. The expression of Dormancy Associated MADS-box, Flowering Locus C-like, Flowering Locus T-like and Terminal Flower 1-like genes was found to be modulated under differential chilling. The co-expression network analysis indentified two high chill specific modules that were found to be enriched for “post-embryonic development” GO terms. The network analysis also identified hub genes including Early flowering 7, RAF10, ZEP4 and F-box, which may be involved in regulating chilling-mediated dormancy release and fruit set. The results of transcriptome and co-expression network analysis indicate that chilling availability majorly regulates phytohormone-related pathways and post-embryonic development during bud break. PMID:28198417

Chilling and cooking rate effects on some myofibrillar determinants of tenderness of beef.

PubMed

King, D A; Dikeman, M E; Wheeler, T L; Kastner, C L; Koohmaraie, M

2003-06-01

Our objectives were to examine the effects of prerigor excision and rapid chilling vs. conventional carcass chilling of two muscles on proteolysis and tenderness during the postmortem storage, as well as the effects of fast and slow rates of cooking on myofibrillar characteristics and tenderness. The longissimus thoracis (LT) and triceps brachii (TB), long head muscles were removed 45 min after exsanguination from the left side of 12 carcasses and chilled in an ice bath to induce cold shortening (excised, rapidly chilled). At 24 h postmortem, the corresponding muscles were removed from the right side (conventionally chilled). All muscles were cut into 2.54-cm-thick steaks and assigned to one of two postmortem times (1 or 14 d), and to raw and cooking treatments. Steaks were cooked at 260 degrees C (FAST) or 93 degrees C (SLOW) in a forced-air convection oven to an internal temperature of 70 degrees C. Cooking loss, cooking time, and Warner-Bratzler shear force (WBSF) were measured on cooked steaks. Sarcomere length (SL) and the extent of proteolysis of desmin were measured on raw and cooked steaks. As expected, the excised, rapidly chilled muscles had a much more rapid (P < 0.05) temperature decline than those that were conventionally chilled. The excised, rapidly chilled treatment resulted in shorter (P < 0.05) SL, and SL was shorter (P < 0.05) in LT than in TB steaks. Raw steaks had longer (P < 0.05) SL than cooked steaks, regardless of chilling treatment. The FAST cooking resulted in shorter (P < 0.05) SL than SLOW cooking in conventionally chilled steaks, but cooking rate had no effect (P > 0.05) on SL of rapidly chilled steaks. Generally, TB steaks required longer (P < 0.05) cooking times and had higher (P < 0.05) cooking losses than LT steaks, and FAST-cooked steaks had greater (P < 0.05) cooking losses than SLOW-cooked steaks. Rapidly chilled steaks had less (P < 0.05) degradation of desmin than conventionally chilled steaks (31 vs. 41%). Aging for 14 d increased (P < 0.05) desmin degradation. Rapid chilling of muscles resulted in much higher (P < 0.05) WBSF values, whereas aging resulted in lower (P < 0.05) WBSF values. The SLOW-cooked TB steaks were more tender (P < 0.05) than FAST-cooked TB steaks and LT steaks cooked at either rate. Excised, rapidly chilled muscles underwent proteolysis, but it occurred at a slower rate during the first 24 h postmortem than it did in conventionally chilled muscles. Cooking rate did not affect tenderness of LT steaks, but SLOW cooking resulted in more tender TB steaks.

Diurnal Changes in the Chilling Sensitivity of Seedlings

PubMed Central

King, Ann I.; Reid, Michael S.; Patterson, Brian D.

1982-01-01

Seedlings of tomato (Lycopersicon esculentum, Mill.) varied diurnally in their sensitivity to chilling temperatures. If chilled near the end of the dark period when they were most sensitive, the time taken to kill half of the seedlings was approximately 3 days, whereas in samples taken 4 hours after the onset of dark, a period of 6 days of chilling was required. Sensitivity dropped rapidly after the onset of the light period. This rhythm was exogenously controlled by the diurnal changes in light, rather than in the temperature. The susceptibility of predawn seedlings could be reduced by exposure to light, by water stress, or by abscisic acid applied to the leaves. However, the subsequent changes in sensitivity to chilling did not correlate with stomatal aperture. Six other chilling-sensitive species showed similar diurnal changes in their chilling sensitivity. Images Fig. 2 PMID:16662448

Tape Placement Head for Applying Thermoplastic Tape to an Object

NASA Technical Reports Server (NTRS)

Cope, Ralph D. (Inventor); Funck, Steve B. (Inventor); Gruber, Mark B. (Inventor); Lamontia, Mark A. (Inventor); Johnson, Anthony D. (Inventor)

2008-01-01

A tape placement head for applying thermoplastic tape to an object includes a heated feeder which guides the tape/tow to a heated zone. The heated zone has a line compactor having a single row of at least one movable heated member. An area compactor is located in the heated zone downstream from the line compactor. The area compactor includes a plurality of rows of movable feet which are extendable toward the tape/tow different distances with respect to each other to conform to the shape of the object. A shim is located between the heated compactors and the tape/tow. A chilled compactor is in a chilled zone downstream from the heated zone. The chilled zone includes a line chilled compactor and an area chilled compactor. A chilled shim is mounted between the chilled compactor and the tape/tow.

Exogenous abscisic acid increases antioxidant enzymes and related gene expression in pepper (Capsicum annuum) leaves subjected to chilling stress.

PubMed

Guo, W L; Chen, R G; Gong, Z H; Yin, Y X; Ahmed, S S; He, Y M

2012-11-28

To elucidate how physiological and biochemical mechanisms of chilling stress are regulated by abscisic acid (ABA) pretreatment, pepper variety (cv. 'P70') seedlings were pretreated with 0.57 mM ABA for 72 h and then subjected to chilling stress at 10°/6°C (day/night). Chilling stress caused severe necrotic lesions on the leaves and increased malondialdehyde and H(2)O(2) levels. Activities of monodehydroascorbate reductase (DHAR), dehydroascorbate reductase, glutathione reductase, guaiacol peroxidase, ascorbate peroxidase, ascorbate, and glutathione increased due to chilling stress during the 72 h, while superoxide dismutase and catalase activities decreased during 24 h, suggesting that chilling stress activates the AsA-GSH cycle under catalase deactivation in pepper leaves. ABA pretreatment induced significant increases in the above-mentioned enzyme activities and progressive decreases in ascorbate and glutathione levels. On the other hand, ABA-pretreated seedlings under chilling stress increased superoxide dismutase and guaiacol peroxidase activities and lowered concentrations of other antioxidants compared with untreated chilling-stressed plants. These seedlings showed concomitant decreases in foliage damage symptoms, and levels of malondialdehyde and H(2)O(2). Induction of Mn-SOD and POD was observed in chilling-stressed plants treated with ABA. The expression of DHAR1 and DHAR2 was altered by chilling stress, but it was higher in the presence than in the absence of ABA at 24 h. Overall, the results indicate that exogenous application of ABA increases tolerance of plants to chilling-induced oxidative damage, mainly by enhancing superoxide dismutase and guaiacol peroxidase activities and related gene expression.

The Role of Left Hemispheric Structures for Emotional Processing as a Monitor of Bodily Reaction and Felt Chill - a Case-Control Functional Imaging Study.

PubMed

Grunkina, Viktoria; Holtz, Katharina; Klepzig, Kai; Neubert, Jörg; Horn, Ulrike; Domin, Martin; Hamm, Alfons O; Lotze, Martin

2016-01-01

Background: The particular function of the left anterior human insula on emotional arousal has been illustrated with several case studies. Only after left hemispheric insula lesions, patients lose their pleasure in habits such as listening to joyful music. In functional magnetic resonance imaging studies (fMRI) activation in the left anterior insula has been associated with both processing of emotional valence and arousal. Tight interactions with different areas of the prefrontal cortex are involved in bodily response monitoring and cognitive appraisal of a given stimulus. Therefore, a large left hemispheric lesion including the left insula should impair the bodily response of chill experience (objective chill response) but leave the cognitive aspects of chill processing (subjective chill response) unaffected. Methods: We investigated a patient (MC) with a complete left hemispheric media cerebral artery stroke, testing fMRI representation of pleasant (music) and unpleasant (harsh sounds) chill response. Results: Although chill response to both pleasant and unpleasant rated sounds was confirmed verbally at passages also rated as chilling by healthy participants, skin conductance response was almost absent in MC. For a healthy control (HC) objective and subjective chill response was positively associated. Bilateral prefrontal fMRI-response to chill stimuli was sustained in MC whereas insula activation restricted to the right hemisphere. Diffusion imaging together with lesion maps revealed that left lateral tracts were completely damaged but medial prefrontal structures were intact. Conclusion: With this case study we demonstrate how bodily response and cognitive appraisal are differentially participating in the internal monitor of chill response.

Tomato expressing Arabidopsis glutaredoxin gene AtGRXS17 confers tolerance to chilling stress via modulating cold responsive components

USDA-ARS?s Scientific Manuscript database

Chilling stress is a production constraint of tomato, a tropical origin, chilling-sensitive horticultural crop. The development of chilling tolerant tomato thus has significant potential to impact tomato production. Glutaredoxins (GRXs) are ubiquitous oxidoreductases, which utilize the reducing powe...

75 FR 32370 - Final Results of Antidumping Duty Changed Circumstances Review: Fresh and Chilled Atlantic Salmon...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-08

... Duty Changed Circumstances Review: Fresh and Chilled Atlantic Salmon from Norway AGENCY: Import... Duty Changed Circumstances Review: Fresh and Chilled Atlantic Salmon from Norway SUMMARY: On August 5... antidumping order on fresh and chilled Atlantic Salmon from Norway and preliminarily determined that Nordic...

Effects of homogenization treatment on recrystallization behavior of 7150 aluminum sheet during post-rolling annealing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Zhanying; Department of Applied Science, University of Québec at Chicoutimi, Saguenay, QC G7H 2B1; Zhao, Gang

2016-04-15

The effects of two homogenization treatments applied to the direct chill (DC) cast billet on the recrystallization behavior in 7150 aluminum alloy during post-rolling annealing have been investigated using the electron backscatter diffraction (EBSD) technique. Following hot and cold rolling to the sheet, measured orientation maps, the recrystallization fraction and grain size, the misorientation angle and the subgrain size were used to characterize the recovery and recrystallization processes at different annealing temperatures. The results were compared between the conventional one-step homogenization and the new two-step homogenization, with the first step being pretreated at 250 °C. Al{sub 3}Zr dispersoids with highermore » densities and smaller sizes were obtained after the two-step homogenization, which strongly retarded subgrain/grain boundary mobility and inhibited recrystallization. Compared with the conventional one-step homogenized samples, a significantly lower recrystallized fraction and a smaller recrystallized grain size were obtained under all annealing conditions after cold rolling in the two-step homogenized samples. - Highlights: • Effects of two homogenization treatments on recrystallization in 7150 Al sheets • Quantitative study on the recrystallization evolution during post-rolling annealing • Al{sub 3}Zr dispersoids with higher densities and smaller sizes after two-step treatment • Higher recrystallization resistance of 7150 sheets with two-step homogenization.« less

Diurnal variation of wind-chill at Thessaloniki, Greece

NASA Astrophysics Data System (ADS)

Balafoutis, Ch. J.

1989-12-01

The diurnal variations of wind-chill at Thessaloniki, Greece, are considered using hourly data from January 1960 to December 1977. This is the first attempt in Greece to describe bioclimatic conditions using wind-chill data. The hourly values of wind-chill were calculated by Siple-Passel's formula which still appears to be most widely used. The values of wind-chill are discussed in terms of Terjung's scale. Thessaloniki does not experience “frost-bite” conditions during the coldest months but does experience “warm” conditions during the summer period. A comparison of hourly and daily mean values show that the means do not indicate the real range of wind-chill during the day.

AIS/DOE Technology Roadmap Program: Strip Casting: Anticipating New Routes To Steel Sheet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prof. Alan W. Camb; Prof. Anthony Rollett

2001-08-31

To determine the potential for strip casting in the steel industry and to develop the fundamental knowledge necessary to allow the role of strip casting in the modern steel industry to be understood. Based upon a study of carbon steel strip castings that were either produced for the program at British Steel or were received from a pre-commercial production machine, the following conclusions were made. Strip casting of carbon steels is technically feasible for sheet material from slightly less than 1 mm thick to 3 mm thick, and, assuming that it is economically viable, it will be first applied inmore » carbon steel markets that do not require stringent surface quality or extensive forming. The potential of strip casting as a casting process to be developed for steel castings is very high as the cast strip has some very novel characteristics. Direct cast carbon strip has better surface quality, shape and profile than any other casting process currently available. The more rapidly solidified structure of direct cast strip tends to be strong with low ductility; however, with adequate thermal treatment, it is possible to develop a variety of properties from the same grade. The process is more amenable at this time to production tonnages per year of the order of 500,000 tons and as such will first find niche type applications. This technology is an additional technology for steel production and will be in addition to, rather than a replacement for, current casting machines.« less

Nondestructive detection of chilling injury in cucumber fruit using hyperspectral imaging with feature selection and supervised classification

USDA-ARS?s Scientific Manuscript database

Chilling injury, as a physiological disorder in cucumbers, occurs after the fruit has been subjected to low temperatures. It is thus desirable to detect chilling injury at early stages and/or remove chilling injured cucumbers during sorting and grading. This research was aimed to apply hyperspectral...

Chilling and chipping influence plant growth and reproduction of star-of-Bethlehem (Ornithogalum umbellatum)

USDA-ARS?s Scientific Manuscript database

Greenhouse studies were conducted on two southern Illinois star-of-Bethlehem biotypes to determine the influence of chilling and bulb chipping on plant growth and reproduction. Chilling was not required for leaf emergence of dormant bulbs, but an increase to 10 weeks of chilling proportionally delay...

77 FR 10772 - Fresh and Chilled Atlantic Salmon From Norway

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-23

... and Chilled Atlantic Salmon From Norway Determination On the basis of the record \\1\\ developed in the... countervailing duty order and antidumping duty order on fresh and chilled Atlantic salmon from Norway would not... and Chilled Atlantic Salmon from Norway: Investigation Nos. 701-TA-302 and 731-TA-454 (Third Review...

Effects of hot boning and moisture enhancement on the eating quality of cull cow beef.

PubMed

Pivotto, L M; Campbell, C P; Swanson, K; Mandell, I B

2014-01-01

The effects of chilling method and moisture enhancement were examined for improving eating quality of semimembranosus (SM) and longissimus lumborum (LL) from 62 cull beef cows. Chilling method included hot boning muscles after 45 to 60 min postmortem or conventional chilling for 24 h. Moisture enhancement included 1) a non-injected control (CONT) or injection processing (10% of product weight) using 2) Sodium Tripolyphosphate/salt (Na/STP), 3) Sodium Citrate (NaCIT), 4) Calcium Ascorbate (CaASC), or 5) Citrus Juices (CITRUS). Chilling method by moisture enhancement treatment interactions (P<0.09) were due to decreased hue, chroma and sarcomere length values in hot boned vs. conventionally chilled product (SM and LL) for CaASC vs. other moisture enhancement treatments. Chilling method by moisture enhancement treatment interactions (P<0.05) were due to decreased shear force and increased tenderness in conventionally chilled vs. hot boned LL using CaASC vs. Na/STP. Moisture enhancement can improve tenderness of cull cow beef depending on combinations of chilling method and moisture enhancement treatments used. © 2013.

Climate change affects winter chill for temperate fruit and nut trees.

PubMed

Luedeling, Eike; Girvetz, Evan H; Semenov, Mikhail A; Brown, Patrick H

2011-01-01

Temperate fruit and nut trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields. We estimated winter chill for two past (1975 and 2000) and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios). For 4,293 weather stations around the world and GCM projections, Safe Winter Chill (SWC), the amount of winter chill that is exceeded in 90% of all years, was estimated for all scenarios using the "Dynamic Model" and interpolated globally. We found that SWC ranged between 0 and about 170 Chill Portions (CP) for all climate scenarios, but that the global distribution varied across scenarios. Warm regions are likely to experience severe reductions in available winter chill, potentially threatening production there. In contrast, SWC in most temperate growing regions is likely to remain relatively unchanged, and cold regions may even see an increase in SWC. Climate change impacts on SWC differed quantitatively among GCMs and GHG scenarios, with the highest GHG leading to losses up to 40 CP in warm regions, compared to 20 CP for the lowest GHG. The extent of projected changes in winter chill in many major growing regions of fruits and nuts indicates that growers of these commodities will likely experience problems in the future. Mitigation of climate change through reductions in greenhouse gas emissions can help reduce the impacts, however, adaption to changes will have to occur. To better prepare for likely impacts of climate change, efforts should be undertaken to breed tree cultivars for lower chilling requirements, to develop tools to cope with insufficient winter chill, and to better understand the temperature responses of tree crops.

Chilling-Mediated DNA Methylation Changes during Dormancy and Its Release Reveal the Importance of Epigenetic Regulation during Winter Dormancy in Apple (Malus x domestica Borkh.).

PubMed

Kumar, Gulshan; Rattan, Usha Kumari; Singh, Anil Kumar

2016-01-01

Winter dormancy is a well known mechanism adopted by temperate plants, to mitigate the chilling temperature of winters. However, acquisition of sufficient chilling during winter dormancy ensures the normal phenological traits in subsequent growing period. Thus, low temperature appears to play crucial roles in growth and development of temperate plants. Apple, being an important temperate fruit crop, also requires sufficient chilling to release winter dormancy and normal phenological traits, which are often associated with yield and quality of fruits. DNA cytosine methylation is one of the important epigenetic modifications which remarkably affect the gene expression during various developmental and adaptive processes. In present study, methylation sensitive amplified polymorphism was employed to assess the changes in cytosine methylation during dormancy, active growth and fruit set in apple, under differential chilling conditions. Under high chill conditions, total methylation was decreased from 27.2% in dormant bud to 21.0% in fruit set stage, while no significant reduction was found under low chill conditions. Moreover, the demethylation was found to be decreased, while methylation increased from dormant bud to fruit set stage under low chill as compared to high chill conditions. In addition, RNA-Seq analysis showed high expression of DNA methyltransferases and histone methyltransferases during dormancy and fruit set, and low expression of DNA glcosylases during active growth under low chill conditions, which was in accordance with changes in methylation patterns. The RNA-Seq data of 47 genes associated with MSAP fragments involved in cellular metabolism, stress response, antioxidant system and transcriptional regulation showed correlation between methylation and their expression. Similarly, bisulfite sequencing and qRT-PCR analysis of selected genes also showed correlation between gene body methylation and gene expression. Moreover, significant association between chilling and methylation changes was observed, which suggested that chilling acquisition during dormancy in apple is likely to affect the epigenetic regulation through DNA methylation.

Chilling-Mediated DNA Methylation Changes during Dormancy and Its Release Reveal the Importance of Epigenetic Regulation during Winter Dormancy in Apple (Malus x domestica Borkh.)

PubMed Central

Kumar, Gulshan; Rattan, Usha Kumari; Singh, Anil Kumar

2016-01-01

Winter dormancy is a well known mechanism adopted by temperate plants, to mitigate the chilling temperature of winters. However, acquisition of sufficient chilling during winter dormancy ensures the normal phenological traits in subsequent growing period. Thus, low temperature appears to play crucial roles in growth and development of temperate plants. Apple, being an important temperate fruit crop, also requires sufficient chilling to release winter dormancy and normal phenological traits, which are often associated with yield and quality of fruits. DNA cytosine methylation is one of the important epigenetic modifications which remarkably affect the gene expression during various developmental and adaptive processes. In present study, methylation sensitive amplified polymorphism was employed to assess the changes in cytosine methylation during dormancy, active growth and fruit set in apple, under differential chilling conditions. Under high chill conditions, total methylation was decreased from 27.2% in dormant bud to 21.0% in fruit set stage, while no significant reduction was found under low chill conditions. Moreover, the demethylation was found to be decreased, while methylation increased from dormant bud to fruit set stage under low chill as compared to high chill conditions. In addition, RNA-Seq analysis showed high expression of DNA methyltransferases and histone methyltransferases during dormancy and fruit set, and low expression of DNA glcosylases during active growth under low chill conditions, which was in accordance with changes in methylation patterns. The RNA-Seq data of 47 genes associated with MSAP fragments involved in cellular metabolism, stress response, antioxidant system and transcriptional regulation showed correlation between methylation and their expression. Similarly, bisulfite sequencing and qRT-PCR analysis of selected genes also showed correlation between gene body methylation and gene expression. Moreover, significant association between chilling and methylation changes was observed, which suggested that chilling acquisition during dormancy in apple is likely to affect the epigenetic regulation through DNA methylation. PMID:26901339

Metallurgical characterization of melt-spun ribbons of U-5.4 wt%Nb alloy

NASA Astrophysics Data System (ADS)

Ma, Rong; Ren, Zhiyong; Tang, Qingfu; Chen, Dong; Liu, Tingyi; Su, Bin; Wang, Zhenhong; Luo, Chao

2018-06-01

The microstructures and micro-mechanical properties of the melt-spun ribbons of U-5.4 wt%Nb alloy were characterized using optical microscopy, scanning electron microscopy, X-ray diffraction and nanoindentation. Observed variations in microstructures and properties are related to the changes in ribbon thicknesses and cooling rates. The microstructures of the melt-spun ribbon consist of fine-scale columnar grains (∼1 μm) adjacent to the chill surface and coarse cellular grains in the remainder of the ribbon. In addition, the formation of inclusions in the ribbon is suppressed kinetically due to the high cooling rate during melt spinning. Compared with the water-quenched specimen prepared by traditional gravity casting and solution heat treatment, the elastic modulus values of the U-5.4 wt%Nb alloy were examined to vary with grain size and exhibited diverse energy dissipation capacities.

The transcriptomic and evolutionary signature of social interactions regulating honey bee caste development.

PubMed

Vojvodic, Svjetlana; Johnson, Brian R; Harpur, Brock A; Kent, Clement F; Zayed, Amro; Anderson, Kirk E; Linksvayer, Timothy A

2015-11-01

The caste fate of developing female honey bee larvae is strictly socially regulated by adult nurse workers. As a result of this social regulation, nurse-expressed genes as well as larval-expressed genes may affect caste expression and evolution. We used a novel transcriptomic approach to identify genes with putative direct and indirect effects on honey bee caste development, and we subsequently studied the relative rates of molecular evolution at these caste-associated genes. We experimentally induced the production of new queens by removing the current colony queen, and we used RNA sequencing to study the gene expression profiles of both developing larvae and their caregiving nurses before and after queen removal. By comparing the gene expression profiles of queen-destined versus worker-destined larvae as well as nurses observed feeding these two types of larvae, we identified larval and nurse genes associated with caste development. Of 950 differentially expressed genes associated with caste, 82% were expressed in larvae with putative direct effects on larval caste, and 18% were expressed in nurses with putative indirect effects on caste. Estimated selection coefficients suggest that both nurse and larval genes putatively associated with caste are rapidly evolving, especially those genes associated with worker development. Altogether, our results suggest that indirect effect genes play important roles in both the expression and evolution of socially influenced traits such as caste.

Sweetgum Dormancy Release: Effects of Chilling, Photoperiod, and Genotype

Treesearch

Robert E. Farmer

1968-01-01

In L., 1200 to 1600 hours of chilling (3 D C) resulted in rapid resumption of growth under greenhouse forcing conditions. Long photoperiods were effective substitutes for chilling. Plants from southern Alabama (Lat. 31°) had a lower chilling requirement than those from western Tennessee (Lat. 36°). Growth rate of plants under...

76 FR 38698 - Fresh and Chilled Atlantic Salmon From Norway; Scheduling of Full Five-Year Reviews Concerning...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-01

... and Chilled Atlantic Salmon From Norway; Scheduling of Full Five-Year Reviews Concerning the Countervailing Duty Order and Antidumping Duty Order on Fresh and Chilled Atlantic Salmon From Norway AGENCY... the antidumping duty order on fresh and chilled Atlantic salmon from Norway would be likely to lead to...

Anisotropic Responses of Mechanical and Thermal Processed Cast Al-Si-Mg-Cu Alloy

NASA Astrophysics Data System (ADS)

Adeosun, S. O.; Akpan, E. I.; Balogun, S. A.; Onoyemi, O. K.

2015-05-01

The effects of ambient directional rolling and heat treatments on ultimate tensile strength (UTS), hardness (HD), percent elongation (PE), and impact energy (IE) on Al-Si-Mg-Cu alloy casting with reference to inclination to rolling direction are discussed in this article. The results show that rolled and quenched (CQ) sample possess superior UTS and HD to as-cast and those of rolled and aged samples (CA). Improved IE resistance with ductility is shown by both CQ and CA samples. However, these mechanical properties are enhanced as changes in the test sample direction moved away from rolling direction for all heat-treated samples. The CQ samples displayed highest tensile strength (108 MPa) and PE (19.8%) in the 90° direction.

Improved Net-Level Filling And Finishing Of Large Castings

NASA Technical Reports Server (NTRS)

Johnson, Erik P.; Brown, Richard F.

1995-01-01

Improved method of vacuum casting of large, generally cylindrical objects to net sizes and shapes reduces amount of direct manual labor by workers in proximity to cast material. Original application for which method devised is fabrication of solid rocket-motor segments containing solid propellant, wherein need to minimize exposure of workers to propellant material being cast. Improved method adaptable to other applications involving large castings of toxic, flammable, or otherwise hazardous materials.

Nut crop yield records show that budbreak-based chilling requirements may not reflect yield decline chill thresholds

NASA Astrophysics Data System (ADS)

Pope, Katherine S.; Dose, Volker; Da Silva, David; Brown, Patrick H.; DeJong, Theodore M.

2015-06-01

Warming winters due to climate change may critically affect temperate tree species. Insufficiently cold winters are thought to result in fewer viable flower buds and the subsequent development of fewer fruits or nuts, decreasing the yield of an orchard or fecundity of a species. The best existing approximation for a threshold of sufficient cold accumulation, the "chilling requirement" of a species or variety, has been quantified by manipulating or modeling the conditions that result in dormant bud breaking. However, the physiological processes that affect budbreak are not the same as those that determine yield. This study sought to test whether budbreak-based chilling thresholds can reasonably approximate the thresholds that affect yield, particularly regarding the potential impacts of climate change on temperate tree crop yields. County-wide yield records for almond ( Prunus dulcis), pistachio ( Pistacia vera), and walnut ( Juglans regia) in the Central Valley of California were compared with 50 years of weather records. Bayesian nonparametric function estimation was used to model yield potentials at varying amounts of chill accumulation. In almonds, average yields occurred when chill accumulation was close to the budbreak-based chilling requirement. However, in the other two crops, pistachios and walnuts, the best previous estimate of the budbreak-based chilling requirements was 19-32 % higher than the chilling accumulations associated with average or above average yields. This research indicates that physiological processes beyond requirements for budbreak should be considered when estimating chill accumulation thresholds of yield decline and potential impacts of climate change.

Chilled water study EEAP program for Walter Reed Army Medical Center: Book 2. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-02-01

The Energy Engineering Analysis Program (EEAP) Study for Walter Reed Army Medical Center (WRAMC) was to provide a thorough examination of the central chilled water plants on site. WRAMC is comprised of seventy-one (71) buildings located on a 113-acre site in Washington, D.C. There are two (2) central chilled water plants (Buildings 48 and 49) each with a primary chilled water distribution system. In addition to the two (2) central plants, three (3) buildings utilize their own independent chillers. Two (2) of the independent chillers (Buildings 7 and T-2), one of which is inoperative (T-2), are smaller air-cooled units, whilemore » the third (Building 54) has a 1,900-ton chilled water plant comprised of three (3) centrifugal chillers. Of the two (2) central chilled water plants, Building 48 houses six (6) chillers totalling 7,080 tons of cooling and Building 49 houses one (1) chiller with 660 tons of cooling. The total chiller cooling capacity available on site is 9,840 tons. The chilled water systems were reviewed for alternative ways of conserving energy on site and reducing the peak-cooling load. Distribution systems were reviewed to determine which buildings were served by each of the chilled water plants and to determine chilled water usage on site. Evaluations were made of building exterior and interior composition in order to estimate cooling loads. Interviews with site personnel helped Entech better understand the chilled water plants, the distribution systems, and how each system was utilized.« less

Effects of broiler carcass scalding and chilling methods on quality of early-deboned breast fillets.

PubMed

Zhuang, Hong; Bowker, Brian C; Buhr, R Jeff; Bourassa, Dianna V; Kiepper, Brian H

2013-05-01

The impact of scalding and chilling methods on quality of broiler breast fillets (pectoralis major) was evaluated. In 4 replications, 6- to 7-wk-old male and female broilers were slaughtered and scalded either at 60°C for 1.5 min (hard scalding) or 52.8°C for 3 min (soft scalding). Following evisceration, the carcasses were either air-chilled (0.5°C, 120 min) or immersion-chilled in water and ice (79 L/carcass, 0.5°C, 40 min, air agitated). Breast fillets were removed from the carcass within 4 h postmortem. Quality attributes including fillet color (both dorsal-bone and ventral-skin sides), pH, total moisture content, water-holding capacity (drip loss and cook loss), and Warner-Bratzler shear force were determined. Significant interactions between replication and scalding were found for pH, ventral side redness (a*) value, and cook loss and between replication and chilling for pH and ventral side a* and yellowness (b*) values. There were no interactions (P > 0.05) between chilling and scalding methods for any of the measurements. Immersion chilling resulted in higher (P < 0.05) ventral side lightness (L*) values, dorsal side b* values, drip loss, cook loss, and shear force compared with air chilling. No significant differences (P > 0.05) between the 2 scalding methods were observed for any of the quality attributes. These results indicate that broiler carcass chilling method has a much greater impact on quality of breast meat than scalding method and that the influence of chilling on breast meat quality is independent of scalding treatment.

Investigation of transient chill down phenomena in tubes using liquid nitrogen

NASA Astrophysics Data System (ADS)

Shukla, A. K.; Sridharan, Arunkumar; Atrey, M. D.

2017-12-01

Chill down of cryogenic transfer lines is a crucial part of cryogenic propulsion as chill down ensures transfer of single phase fluid to the storage tanks of cryogenic engines. It also ensures single phase liquid flow at the start of the engine. Chill down time depends on several parameters such as length of the pipe, pipe diameter, orientation, mass flux etc. To understand the effect of these parameters, experiments are carried out in a set up designed and fabricated at Indian Institute of Technology Bombay using tubes of two different diameters. Experiments are conducted at different inlet pressures and mass flow rate values to understand their effect. Two different pipe sizes are taken to study the effect of variation in diameter on chill down time and quantity of cryogen required. Different orientations are taken to understand their effect on the chill down time, heat transfer coefficient and critical heat flux for the same inlet pressure and mass flux. Pipe inner wall temperature, heat transfer coefficient for different boiling regimes and critical heat flux are calculated based on measured outer surface temperature history for each case. A one dimensional energy conservation equation is solved for transient chill down process considering constant mass flux and inlet pressure to predict the chill down time. Temperature variation during chill down obtained from the numerical simulations are compared with the measured temperature history.

Ion and water balance in Gryllus crickets during the first twelve hours of cold exposure.

PubMed

Des Marteaux, Lauren E; Sinclair, Brent J

2016-06-01

Insects lose ion and water balance during chilling, but the mechanisms underlying this phenomenon are based on patterns of ion and water balance observed in the later stages of cold exposure (12 or more hours). Here we quantified the distribution of ions and water in the hemolymph, muscle, and gut in adult Gryllus field crickets during the first 12h of cold exposure to test mechanistic hypotheses about why homeostasis is lost in the cold, and how chill-tolerant insects might maintain homeostasis to lower temperatures. Unlike in later chill coma, hemolymph [Na(+)] and Na(+) content in the first few hours of chilling actually increased. Patterns of Na(+) balance suggest that Na(+) migrates from the tissues to the gut lumen via the hemolymph. Imbalance of [K(+)] progressed gradually over 12h and could not explain chill coma onset (a finding consistent with recent studies), nor did it predict survival or injury following 48h of chilling. Gryllus veletis avoided shifts in muscle and hemolymph ion content better than Gryllus pennsylvanicus (which is less chill-tolerant), however neither species defended water, [Na(+)], or [K(+)] balance during the first 12h of chilling. Gryllus veletis better maintained balance of Na(+) content and may therefore have greater tissue resistance to ion leak during cold exposure, which could partially explain faster chill coma recovery for that species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of tissue deterioration of ripening banana fruit (Musa spp., AAA group, Cavendish subgroup) under chilling and non-chilling temperatures.

PubMed

Ramírez-Sánchez, Maricruz; Huber, Donald J; Vallejos, Carlos E

2018-03-08

In fleshy fruits, induced programmed cell death (PCD) has been observed in heat-treated tomato, and in ethylene-treated and low-temperature exposure in immature cucumber. No other fleshy fruit has been evaluated for chilling-injury-induced PCD, especially mature fruit with full ripening capacity. The purpose of this research was to identify and evaluate the presence of PCD processes during the development of low-temperature-induced physiopathy of banana fruit. Exposure of fruit to 5 °C for 4 days induced degradative processes similar to those occurring during ripening and overripening of non-chilled fruit. Nuclease from banana peel showed activity in both DNA substrates and RNA substrates. No exclusive low-temperature-induced proteases and nucleases were observed. DNA of chilled peel showed earlier signs of degradation and higher levels of DNA tailing during overripening. This study shows that exposure to low temperatures did not induce a pattern of degradative processes that differed from that occurring during ripening and overripening of non-chilled fruit. DNA showed earlier signs of degradation and higher levels of DNA tailing. Nuclease activity analysis showed bifunctionality in both chilled and non-chilled tissue and no chilling-exclusive protease and nuclease. Fleshy fruit might use their available resources on degradative processes and adjust them depending on environmental conditions. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Chilling and heat requirements for flowering in temperate fruit trees

NASA Astrophysics Data System (ADS)

Guo, Liang; Dai, Junhu; Ranjitkar, Sailesh; Yu, Haiying; Xu, Jianchu; Luedeling, Eike

2014-08-01

Climate change has affected the rates of chilling and heat accumulation, which are vital for flowering and production, in temperate fruit trees, but few studies have been conducted in the cold-winter climates of East Asia. To evaluate tree responses to variation in chill and heat accumulation rates, partial least squares regression was used to correlate first flowering dates of chestnut ( Castanea mollissima Blume) and jujube ( Zizyphus jujube Mill.) in Beijing, China, with daily chill and heat accumulation between 1963 and 2008. The Dynamic Model and the Growing Degree Hour Model were used to convert daily records of minimum and maximum temperature into horticulturally meaningful metrics. Regression analyses identified the chilling and forcing periods for chestnut and jujube. The forcing periods started when half the chilling requirements were fulfilled. Over the past 50 years, heat accumulation during tree dormancy increased significantly, while chill accumulation remained relatively stable for both species. Heat accumulation was the main driver of bloom timing, with effects of variation in chill accumulation negligible in Beijing's cold-winter climate. It does not seem likely that reductions in chill will have a major effect on the studied species in Beijing in the near future. Such problems are much more likely for trees grown in locations that are substantially warmer than their native habitats, such as temperate species in the subtropics and tropics.

Chilling and heat requirements for flowering in temperate fruit trees.

PubMed

Guo, Liang; Dai, Junhu; Ranjitkar, Sailesh; Yu, Haiying; Xu, Jianchu; Luedeling, Eike

2014-08-01

Climate change has affected the rates of chilling and heat accumulation, which are vital for flowering and production, in temperate fruit trees, but few studies have been conducted in the cold-winter climates of East Asia. To evaluate tree responses to variation in chill and heat accumulation rates, partial least squares regression was used to correlate first flowering dates of chestnut (Castanea mollissima Blume) and jujube (Zizyphus jujube Mill.) in Beijing, China, with daily chill and heat accumulation between 1963 and 2008. The Dynamic Model and the Growing Degree Hour Model were used to convert daily records of minimum and maximum temperature into horticulturally meaningful metrics. Regression analyses identified the chilling and forcing periods for chestnut and jujube. The forcing periods started when half the chilling requirements were fulfilled. Over the past 50 years, heat accumulation during tree dormancy increased significantly, while chill accumulation remained relatively stable for both species. Heat accumulation was the main driver of bloom timing, with effects of variation in chill accumulation negligible in Beijing’s cold-winter climate. It does not seem likely that reductions in chill will have a major effect on the studied species in Beijing in the near future. Such problems are much more likely for trees grown in locations that are substantially warmer than their native habitats, such as temperate species in the subtropics and tropics.

Chilling hours: Myths and facts

Treesearch

David B. South

2013-01-01

This paper is a critical review of over four decades of research on chilling with southern pine seedlings. For most pines, freeze tolerance, seed dormancy, and endodormancy of terminal buds are affected by natural chilling (0° to 8 °C [32 to 46 °F]). Unfortunately, in the field of reforestation, several myths have emerged regarding the importance of chilling. One myth...

Quality and safety of fish curry processed by sous vide cook chilled and hot filled technology process during refrigerated storage.

PubMed

Shakila, R Jeya; Raj, B Edwin; Felix, N

2012-06-01

Fish curry, a traditional Indian dish was prepared from farmed fish Cobia (Rachycentron canadum), packaged by two different cook-chill processes namely, sous vide cook chilled and hot filled technology and held at 2 °C. Biochemical composition revealed that fish curry contained 5% protein and 6% fat. Omega-3 fatty acids, eicosapentaenoic acid (EPA) retained 55.44% while docosahexaenoic acid (DHA) retained 29% during cook-chilling process. The major fatty acids in fish curry were C18:2, C12:0, C16:0 and C18:1. Shelf-life of sous vide cook chilled and hot filled technology processed fish curry were 8 and 12 weeks, respectively. Total bacterial counts were detected after 4 weeks and 12 weeks in sous vide cook chilled and hot filled technology processes, respectively. Total staphylococci were detected in sous vide cook chilled and hot filled technology processed cobia fish curry after 4 and 12 weeks, respectively. Total bacilli, anaerobic sulfite reducing clostridia, Salmonella, and lactic acid bacteria were absent. Hot filled technology process was more efficient and could be applied for chilled fish curry preservation for 12 weeks without any safety problems.

Quality assessment of rainbow trout (Oncorhynchus mykiss) fillets during super chilling and chilled storage.

PubMed

Shen, Song; Jiang, Yan; Liu, Xiaochang; Luo, Yongkang; Gao, Liang

2015-08-01

In order to evaluate the effect of super chilling (-3 °C) and chilled (3 °C) storage on the quality of rainbow trout fillets, total volatile base nitrogen (TVB-N), drip loss, pH, electric conductivity (EC), total aerobic count (TAC), K and related values, adenosine triphosphate (ATP) and related compounds, color and sensory score were determined and correlation between these indicators were analyzed. According to the comprehensive evaluation of TAC, K value and sensory score, the limit for acceptability of rainbow trout fillets was 5 days at 3 °C and 11 days at -3 °C. Additionally, the correlation coefficients between TVB-N and other freshness indicators (TAC, K value, sensory score) were relatively low. TVB-N may be inadequate for evaluating freshness changes of rainbow trout fillets compared with other indicators. Among the K and related values, H value was a better freshness indicator in rainbow trout fillets during chilled and super chilling storage for its better correlation coefficients with other freshness indicators. Super chilling storage could extend the shelf life of rainbow trout fillets by 6 days compared to chilled storage.

Effects of -1.5°C Super-chilling on quality of Atlantic salmon (Salmo salar) pre-rigor Fillets: Cathepsin activity, muscle histology, texture and liquid leakage.

PubMed

Bahuaud, D; Mørkøre, T; Langsrud, Ø; Sinnes, K; Veiseth, E; Ofstad, R; Thomassen, M S

2008-11-15

The aim of this study was to evaluate the impact of super-chilling on the quality of Atlantic salmon (Salmo salar) pre-rigor fillets. The fillets were kept for 45min in a super-chilling tunnel at -25°C with an air speed in the tunnel at 2.5m/s, to reach a fillet core temperature of -1.5°C, prior to ice storage in a cold room for 4 weeks. Super-chilling seemed to form intra- and extracellular ice crystals in the upper layer of the fillets and prevent myofibre contraction. Lysosome breakages followed by release of cathepsin B and L during storage and myofibre-myofibre detachments were accelerated in the super-chilled fillets. Super-chilling resulted in higher liquid leakage and increased myofibre breakages in the fillets, while texture values of fillets measured instrumentally were not affected by super-chilling one week after treatment. Optimisation of the super-chilling technique is needed to avoid the formation of ice crystals, which may cause irreversible destruction of the myofibres, in order to obtain high quality products. Copyright © 2008 Elsevier Ltd. All rights reserved.

Effect of ageing time on suckling lamb meat quality resulting from different carcass chilling regimes.

PubMed

Vieira, C; Fernández, A M

2014-02-01

The effect of ageing on suckling lamb carcasses subjected to three chilling treatments was studied: Conventional (2 °C for 24h), ultra-fast (-20 °C for 3.5h then 2 °C until 24h post mortem) and slow chilling (12 °C for 7h then 2 °C until 24h post mortem) treatments. Meat quality measurements were carried out in carcasses at 24h post mortem and also after 5 days of ageing. Carcass chilling losses were not affected by a chilling regime. Aged meat showed higher cooking losses than non-aged meat (p<0.05). Sarcomere length of ultra-fast t was shorter (p<0.05) than conventional and conventional was shorter than slow chilling treatment (p<0.05), at 24h and after 5 days of ageing. Conventional and ultra-fast chilling treatments resulted in higher shear force values at 24h post mortem (p<0.05) compared to slow treatment. All treatments improved sensory scores with ageing (p<0.05), but ultra-fast chilling treatment did not attain higher values as the other two treatments. © 2013.

The effects of chilling stress after anthesis on the physicochemical properties of rice (Oryza sativa L) starch.

PubMed

Zhu, Dawei; Wei, Haiyan; Guo, Baowei; Dai, Qigen; Wei, Cunxu; Gao, Hui; Hu, Yajie; Cui, Peiyuan; Li, Min; Huo, Zhongyang; Xu, Ke; Zhang, Hongcheng

2017-12-15

This study investigates the effect of chilling stress, over a period of three days after anthesis, on the physicochemical properties of starches derived from six rice cultivars. Chilling stress significantly affected the grain characteristics and physicochemical properties of rice starches, except for those of two varieties, NJ 9108 and ZD 18. In the other four rice cultivars subjected to chilling stress, the content of medium, and large sized granules showed a decrease, and an increase, respectively. Amylose content increased as a result of chilling stress, thereby resulting in starch with a lower swelling power, water solubility, and higher retrogradation enthalpy and gelatinization temperature. Chilling stress led to deterioration of cooked rice quality as determined by the pasting properties of starch. This study indicated that among the cultivars studied, the two rice varieties most resistant to chilling stress after rice anthesis were NJ 9108 and ZD 18. Copyright © 2017 Elsevier Ltd. All rights reserved.

Long-term red meat preservation using chilled and frozen storage combinations: A review.

PubMed

Coombs, Cassius E O; Holman, Benjamin W B; Friend, Michael A; Hopkins, David L

2017-03-01

This paper reviews current literature relating to the effects of chilled and frozen storage on the quality characteristics of red meat (lamb and beef). These characteristics include tenderness (shear force), juiciness (fluid losses), flavour (lipid oxidation), colour and microbial loading. Research suggests that chilled storage of red meat can improve certain properties, such as shear force and species-specific flavour, to threshold levels before the effects on flavour and colour become deleterious, and key microbial species proliferate to spoilage levels. For frozen red meat, the negative effects upon quality traits are prevented when stored for shorter durations, although chilled storage conditions prior to freezing and retail display post-thawing can both positively and negatively affect these traits. Here, we review the effects of different chilled, frozen and combined chilled and frozen storage practices (particularly the chilled-then-frozen combination) on meat quality and spoilage traits, in order to contribute to superior management of these traits during product distribution. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Aquifer thermal-energy-storage costs with a seasonal-chill source

NASA Astrophysics Data System (ADS)

Brown, D. R.

1983-01-01

The cost of energy supplied by an aquifer thermal energy storage (ATES) ystem from a seasonal chill source was investigated. Costs were estimated for point demand and residential development ATES systems using the computer code AQUASTOR. AQUASTOR was developed at PNL specifically for the economic analysis of ATES systems. In this analysis the cost effect of varying a wide range of technical and economic parameters was examined. Those parameters exhibiting a substantial influence on the costs of ATES delivered chill were: system size; well flow rate; transmission distance; source temperature; well depth; and cost of capital. The effects of each parameter are discussed. Two primary constraints of ATES chill systems are the extremely low energy density of the storage fluid and the prohibitive costs of lengthly pipelines for delivering chill to residential users. This economic analysis concludes that ATES-delivered chill will not be competitive for residential cooling applications. The otherwise marginal attractiveness of ATES chill systems vanishes under the extremely low load factors characteristic of residential cooling systems. (LCL)

An evaluation of the wind chill factor: its development and applicability.

PubMed

Bluestein, M

1998-04-01

The wind chill factor has become a standard meteorologic term in cold climates. Meteorologic charts provide wind chill temperatures meant to represent the hypothetical air temperature that would, under conditions of no wind, effect the same heat loss from unclothed human skin as does the actual combination of air temperature and wind velocity. As this wind chill factor has social and economic significance, an investigation was conducted on the development of this factor and its applicability based on modern heat transfer principles. The currently used wind chill factor was found to be based on a primitive study conducted by the U.S. Antarctic Service over 50 years ago. The resultant equation for the wind chill temperature assumes an unrealistic constant skin temperature and utilizes heat transfer coefficients that differ markedly from those obtained from equations of modern convective heat transfer methods. The combined effect of these two factors is to overestimate the effect of a given wind velocity and to predict a wind chill temperature that is too low.

Improving meat quality of organic pork through post mortem handling of carcasses: an innovative approach.

PubMed

Therkildsen, Margrethe; Kristensen, Lars; Kyed, Sybille; Oksbjerg, Niels

2012-06-01

This study was conducted to examine the best combination of post mortem chilling, suspension and ageing in order to optimize tenderness of organic pork at slaughter, which may be tougher than conventionally produced pork, because of lower daily gain. Combinations of stepwise chilling with a holding period of 6h at 10°C or traditional blast tunnel chilling, suspension in the pelvic bone or Achilles Tendon and ageing 2 or 4 days post mortem were tested. Stepwise chilling and ageing improved tenderness of the loin, and the effects were additive, whereas pelvic suspension was less effective in texture improvements, and non-additive to stepwise chilling. Stepwise chilling improved tenderness to a similar degree as can be obtained within 2-4 days of extended ageing, however, the minimum temperature during the holding period seems to be crucial in order to obtain a positive effect of stepwise chilling, and it should be above 7.5°C. Copyright © 2011 Elsevier Ltd. All rights reserved.

Freckle Defect Formation near the Casting Interfaces of Directionally Solidified Superalloys

PubMed Central

Hong, Jianping; Ma, Dexin; Wang, Jun; Wang, Fu; Sun, Baode; Dong, Anping; Li, Fei; Bührig-Polaczek, Andreas

2016-01-01

Freckle defects usually appear on the surface of castings and industrial ingots during the directional solidification process and most of them are located near the interface between the shell mold and superalloys. Ceramic cores create more interfaces in the directionally solidified (DS) and single crystal (SX) hollow turbine blades. In order to investigate the location of freckle occurrence in superalloys, superalloy CM247 LC was directionally solidified in an industrial-sized Bridgman furnace. Instead of ceramic cores, Alumina tubes were used inside of the casting specimens. It was found that freckles occur not only on the casting external surfaces, but also appear near the internal interfaces between the ceramic core and superalloys. Meanwhile, the size, initial position, and area of freckle were investigated in various diameters of the specimens. The initial position of the freckle chain reduces when the diameter of the rods increase. Freckle area follows a linear relationship in various diameters and the average freckle fraction is 1.1% of cross sectional area of casting specimens. The flow of liquid metal near the interfaces was stronger than that in the interdendritic region in the mushy zone, and explained why freckle tends to occur on the outer or inner surfaces of castings. This new phenomenon suggests that freckles are more likely to occur on the outer or inner surfaces of the hollow turbine blades. PMID:28774050

Freckle Defect Formation near the Casting Interfaces of Directionally Solidified Superalloys.

PubMed

Hong, Jianping; Ma, Dexin; Wang, Jun; Wang, Fu; Sun, Baode; Dong, Anping; Li, Fei; Bührig-Polaczek, Andreas

2016-11-16

Freckle defects usually appear on the surface of castings and industrial ingots during the directional solidification process and most of them are located near the interface between the shell mold and superalloys. Ceramic cores create more interfaces in the directionally solidified (DS) and single crystal (SX) hollow turbine blades. In order to investigate the location of freckle occurrence in superalloys, superalloy CM247 LC was directionally solidified in an industrial-sized Bridgman furnace. Instead of ceramic cores, Alumina tubes were used inside of the casting specimens. It was found that freckles occur not only on the casting external surfaces, but also appear near the internal interfaces between the ceramic core and superalloys. Meanwhile, the size, initial position, and area of freckle were investigated in various diameters of the specimens. The initial position of the freckle chain reduces when the diameter of the rods increase. Freckle area follows a linear relationship in various diameters and the average freckle fraction is 1.1% of cross sectional area of casting specimens. The flow of liquid metal near the interfaces was stronger than that in the interdendritic region in the mushy zone, and explained why freckle tends to occur on the outer or inner surfaces of castings. This new phenomenon suggests that freckles are more likely to occur on the outer or inner surfaces of the hollow turbine blades.

A study on the kinetic behavior of Listeria monocytogenes in ice cream stored under static and dynamic chilling and freezing conditions.

PubMed

Gougouli, M; Angelidis, A S; Koutsoumanis, K

2008-02-01

The kinetic behavior of Listeria monocytogenes in 2 commercial ice cream products (A and B) that were inoculated and stored under static chilling (4 to 16 degrees C), static freezing (-5 to -33 degrees C), dynamic chilling, and dynamic chilling-freezing conditions was studied, simulating conditions of the aging process and of normal or abuse conditions during distribution and storage. The ice cream products A and B had different compositions but similar pH (6.50 and 6.67, respectively) and water activity (0.957 and 0.965, respectively) values. For both chilling and freezing conditions, the kinetic behavior of the pathogen was similar in the 2 products, indicating that the pH and water activity, together with temperature, were the main factors controlling growth. Under chilling conditions, L. monocytogenes grew well at all temperatures tested. Under freezing conditions, no significant changes in the population of the pathogen were observed throughout a 90-d storage period for either of the inoculum levels tested (10(3) and 10(6) cfu/g). Growth data from chilled storage conditions were fitted to a mathematical model, and the calculated maximum specific growth rate was modeled as a function of temperature by using a square root model. The model was further validated under dynamic chilling and dynamic chilling-freezing conditions by using 4 different storage temperature scenarios. Under dynamic chilling conditions, the model accurately predicted the growth of the pathogen in both products, with 99.5% of the predictions lying within the +/- 20% relative error zone. The results from the chilling-freezing storage experiments showed that the pathogen was able to initiate growth within a very short time after a temperature upshift from freezing to chilling temperatures. This indicates that the freezing conditions did not cause a severe stress in L. monocytogenes cells capable of leading to a significant "additional" lag phase during the subsequent growth of the pathogen at chilling conditions. As a result, the application of the model at chilling-freezing conditions resulted in satisfactory performance, with 98.3% of the predictions lying within the +/- 20% relative error zone. The present study provides useful data for understanding the behavior of L. monocytogenes in ice cream stored under single or combined chilling and freezing conditions. In addition, the study showed that such data can be expressed in quantitative terms via the application of mathematical models, which can be used by the dairy industry as effective tools for predicting the behavior of the pathogen during the manufacture, distribution, and storage of ice cream products.

Validation of a model for the cast-film process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chambon, F.; Ohlsson, S.; Silagy, D.

1996-12-31

We have developed a model of the cast-film process and compared theoretical predictions against experiments on a pilot line. Three polyethylenes with a markedly different level of melt elasticity were used in this evaluation; namely, a high pressure low density polyethylene, LDPE, and two linear low density polyethylenes, LLDPE-1 and LLDPE-2. The final film dimensions of the LDPE were found to be in good agreement with 1-D viscoelastic stationary predictions. Flow field visualization experiments indicate, however, a 2-D velocity field in the airgap between the extrusion die and the chill roll. Taking this observation into account, evolutions of the freemore » surface of the web along the airgap were recorded with LLDPE-2, our least elastic melt. An excellent agreement is found between these measurements and predictions of neck-in and edge bead with 2-D Newtonian stationary simulations. The time-dependent solution, which is based on a linear stability analysis, allows to identify a zone of draw resonance within the working space of the process, defined by the draw ratio, the Deborah number, and the web aspect ratio. It is predicted that increasing this latter parameter stabilizes the process until an optimum value is reached. Experiments with LLDPE-1 are shown to validate this unique theoretical result, thus allowing to increase the draw ratio by about 75%.« less

Application of TRIZ Theory in Patternless Casting Manufacturing Technique

NASA Astrophysics Data System (ADS)

Yang, Weidong; Gan, Dequan; Jiang, Ping; Tian, Yumei

The ultimate goal of Patternless Casting Manufacturing (referred to as PCM) is how to obtain the casts by casting the sand mold directly. In the previous PCM, the resin content of sand mold is much higher than that required by traditional resin sand, so the casts obtained are difficult to be sound and qualified products, which limits the application of this technique greatly. In this paper, the TRIZ algorithm is introduced to the innovation process in PCM systematically.

Comparative Evaluation of Conventional and Accelerated Castings on Marginal Fit and Surface Roughness.

PubMed

Jadhav, Vivek Dattatray; Motwani, Bhagwan K; Shinde, Jitendra; Adhapure, Prasad

2017-01-01

The aim of this study was to evaluate the marginal fit and surface roughness of complete cast crowns made by a conventional and an accelerated casting technique. This study was divided into three parts. In Part I, the marginal fit of full metal crowns made by both casting techniques in the vertical direction was checked, in Part II, the fit of sectional metal crowns in the horizontal direction made by both casting techniques was checked, and in Part III, the surface roughness of disc-shaped metal plate specimens made by both casting techniques was checked. A conventional technique was compared with an accelerated technique. In Part I of the study, the marginal fit of the full metal crowns as well as in Part II, the horizontal fit of sectional metal crowns made by both casting techniques was determined, and in Part III, the surface roughness of castings made with the same techniques was compared. The results of the t -test and independent sample test do not indicate statistically significant differences in the marginal discrepancy detected between the two casting techniques. For the marginal discrepancy and surface roughness, crowns fabricated with the accelerated technique were significantly different from those fabricated with the conventional technique. Accelerated casting technique showed quite satisfactory results, but the conventional technique was superior in terms of marginal fit and surface roughness.

H(+) -ATPase-defective variants of Lactobacillus delbrueckii subsp. bulgaricus contribute to inhibition of postacidification of yogurt during chilled storage.

PubMed

Wang, Xinhui; Ren, Hongyang; Liu, Dayu; Wang, Bing; Zhu, Wenyou; Wang, Wei

2013-02-01

Continued acid production by Lactobacillus delbrueckii subsp. bulgaricus during the chilled storage of yogurt is the major cause of postacidification, resulting in a short shelf life. Two H(+) -ATPase defective variants of L. delbrueckii subsp. bulgaricus were successfully isolated and their H(+) -ATPase activities were reduced by 51.3% and 34.3%, respectively. It was shown that growth and acid production of variants were remarkably inhibited. The variants were more sensitive to acidic condition and had a significant rate for inactivation of H(+) -ATPase by N, N-dicyclohexylcarbodiimide (DCCD), along with a low H(+) -extrusion, suggesting that H(+) -ATPase is direct response for H(+) -extrusion. In addition, the variants were also more sensitive to NaCl, while H(+) -ATPase activities of variants and parent strain were significantly enhanced by NaCl stress. Obviously, H(+) -ATPase might be involved in Na(+) transportation. Furthermore, variants were inoculated in fermented milk to ferment yogurt. There was no significant difference in flavor, whereas the postacidification of yogurt during chilled storage was remarkably inhibited. It is suggested that application of L. delbrueckii subsp. bulgaricus with reduced H(+) -ATPase activity in yogurt fermentation is one of effect, economic and simple avenues of inhibiting postacidification of yogurt during refrigerated storage, giving a longer shelf life. During yogurt fermentation, continued acid production by Lactobacillus delbrueckii subsp. bulgaricus during the chilled storage of yogurt leads to milk fermentation with high postacidification, resulting in a short shelf life. In this work, 2 acid-sensitive variant strains of L. delbrueckii subsp. bulgaricus were isolated. The characteristics related to H(+) -ATPase were compared and it was observed that milk fermented by the variants had lower postacidification, giving a longer shelf life. Application of L. delbrueckii subsp. bulgaricus with reduced H(+) -ATPase activity in yogurt fermentation might be one of effect, economic and simple avenues of inhibiting yogurt postacidification during chilled storage, giving a longer shelf life. © 2013 Institute of Food Technologists®

Expression of three sHSP genes involved in heat pretreatment-induced chilling tolerance in banana fruit.

PubMed

He, Li-hong; Chen, Jian-ye; Kuang, Jian-fei; Lu, Wang-jin

2012-07-01

Banana fruit is highly susceptible to chilling injury. In previous research it was shown that heat pretreatment of banana fruit at 38 °C for 3 days before storage at a chilling temperature of 8 °C for 12 days prevented increases in visible chilling injury index, electrolyte leakage and malondialdehyde content and also decreases in lightness and chroma, indicating that heat pretreatment could effectively alleviate chilling injury of banana fruit. However, little is known about the role of small heat shock proteins (sHSPs) in postharvest chilling tolerance of banana fruit. In the present study, three cytosolic sHSP expression profiles in peel and pulp tissues of banana fruit during heat pretreatment and subsequent chilled storage (8 °C) were investigated in relation to heat pretreatment-induced chilling tolerance. Three full-length cDNAs of cytosolic sHSP genes, including two class I sHSP (CI sHSP) and one class II sHSP (CII sHSP) cDNAs, named Ma-CI sHSP1, Ma-CI sHSP2 and Ma-CII sHSP3 respectively, were isolated and characterised from harvested banana fruit. Accumulation of Ma-CI sHSP1 mRNA transcripts in peel and pulp tissues and Ma-CII sHSP3 mRNA transcripts in peel tissue increased during heat pretreatment. Expression of all three Ma-sHSP genes in peel and pulp tissues was induced during subsequent chilled storage. Furthermore, Ma-CI sHSP1 and Ma-CII sHSP3 mRNA transcripts in pulp tissue and Ma-CI sHSP2 mRNA transcripts in peel and pulp tissues were obviously enhanced by heat pretreatment at days 6 and 9 of subsequent chilled storage. These results suggested that heat pretreatment enhanced the expression of Ma-sHSPs, which might be involved in heat pretreatment-induced chilling tolerance of banana fruit. Copyright © 2012 Society of Chemical Industry.

Climate Change Affects Winter Chill for Temperate Fruit and Nut Trees

PubMed Central

Luedeling, Eike; Girvetz, Evan H.; Semenov, Mikhail A.; Brown, Patrick H.

2011-01-01

Background Temperate fruit and nut trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields. Methodology/Principal Findings We estimated winter chill for two past (1975 and 2000) and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios). For 4,293 weather stations around the world and GCM projections, Safe Winter Chill (SWC), the amount of winter chill that is exceeded in 90% of all years, was estimated for all scenarios using the “Dynamic Model” and interpolated globally. We found that SWC ranged between 0 and about 170 Chill Portions (CP) for all climate scenarios, but that the global distribution varied across scenarios. Warm regions are likely to experience severe reductions in available winter chill, potentially threatening production there. In contrast, SWC in most temperate growing regions is likely to remain relatively unchanged, and cold regions may even see an increase in SWC. Climate change impacts on SWC differed quantitatively among GCMs and GHG scenarios, with the highest GHG leading to losses up to 40 CP in warm regions, compared to 20 CP for the lowest GHG. Conclusions/Significance The extent of projected changes in winter chill in many major growing regions of fruits and nuts indicates that growers of these commodities will likely experience problems in the future. Mitigation of climate change through reductions in greenhouse gas emissions can help reduce the impacts, however, adaption to changes will have to occur. To better prepare for likely impacts of climate change, efforts should be undertaken to breed tree cultivars for lower chilling requirements, to develop tools to cope with insufficient winter chill, and to better understand the temperature responses of tree crops. PMID:21629649

Factors associated with Salmonella prevalence on pork carcasses in very small abattoirs in Wisconsin.

PubMed

Algino, R J; Badtram, G A; Ingham, B H; Ingham, S C

2009-04-01

The U.S. Department of Agriculture has expressed concern over Salmonella prevalence on pork carcasses. Our objectives were to survey the prevalence of Salmonella on pork carcasses in very small Wisconsin abattoirs, and identify processing conditions and indicator bacteria levels associated with reduced Salmonella prevalence. During April to July 2007, sponge samples were obtained from 181 pork carcasses at 10 Wisconsin abattoirs before carcass washing (carcass half A), and after washing and chilling and before fabrication (carcass half B). Each sample was categorized by whether the carcass was skinned, by wash-water temperature (7 to 43 degrees C), and the duration (1 or 2 days), temperature, and percent relative humidity of chilling. Sponge samples were analyzed qualitatively for Salmonella and quantitatively for Escherichia coli, coliforms, Enterobacteriaceae, and aerobic plate count (APC). Salmonella prevalences on skinned and unskinned prewash carcasses were 11.7 and 8.3%, respectively. Corresponding values for chilled carcasses were 32.0 and 19.5% for 1-day chilled carcasses, and 11.4 and 14.7% for 2-day chilled carcasses. Lower Salmonella prevalence on prewash carcasses was significantly related to lower prewash carcass APC levels (odds ratio = 7.8 per change of 1.0 log CFU/cm2), while lower Salmonella prevalence on chilled carcasses was significantly related to 2-day chilling (odds ratio = 5.2), and chilled-carcass levels of coliforms, Enterobacteriaceae, and APC (odds ratio = 1.5 to 1.9 per change of 1.0 log CFU/cm2). Salmonella prevalence on chilled pork carcasses in very small Wisconsin plants could be reduced by chilling carcasses 2 days before fabrication and improving carcass-handling hygiene.

Nitric Oxide Mediates 5-Aminolevulinic Acid-Induced Antioxidant Defense in Leaves of Elymus nutans Griseb. Exposed to Chilling Stress

PubMed Central

Fu, Juanjuan; Chu, Xitong; Sun, Yongfang; Miao, Yanjun; Xu, Yuefei; Hu, Tianming

2015-01-01

Nitric oxide (NO) and 5-aminolevulinic acid (ALA) are both extremely important signalling molecules employed by plants to control many aspects of physiology. In the present study, the role of NO in ALA-induced antioxidant defense in leaves of two sources of Elymus nutans Griseb. (Damxung, DX and Zhengdao, ZD) was investigated. Chilling stress enhanced electrolyte leakage, accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide radical in two E. nutans, which were substantially alleviated by exogenous ALA and NO application. Pretreatment with NO scavenger PTIO or NOS inhibitor L-NNA alone and in combination with ALA induced enhancements in electrolyte leakage and the accumulation of MDA, H2O2 and superoxide radical in leaves of DX and ZD exposed to chilling stress, indicating that the inhibition of NO biosynthesis reduced the chilling resistance of E. nutans and the ALA-enhanced chilling resistance. Further analyses showed that ALA and NO enhanced antioxidant defense and activated plasma membrane (PM) H+-ATPase and decreased the accumulation of ROS induced by chilling stress. A pronounced increase in nitric oxide synthase (NOS) activity and NO release by exogenous ALA treatment was found in chilling-resistant DX plants exposed to chilling stress, while only a little increase was observed in chilling-sensitive ZD. Furthermore, inhibition of NO accumulation by PTIO or L-NNA blocked the protective effect of exogenous ALA, while both exogenous NO treatment and inhibition of endogenous NO accumulation did not induce ALA production. These results suggested that NO might be a downstream signal mediating ALA-induced chilling resistance in E. nutans. PMID:26151364

7 CFR 1560.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., fresh or chilled. 07.02 Tomatoes, fresh or chilled. 07.03 Onions, shallots, garlic, leeks, and other... chilled. 08.06.10 Grapes, fresh. 08.08.20 Pears and quinces, fresh. 08.09 Apricots, cherries, peaches...

Windward Cooling: An Overlooked Factor in the Calculation of Wind Chill.

NASA Astrophysics Data System (ADS)

Osczevski, Randall J.

2000-12-01

Wind chill equivalent temperatures calculated from a recent vertical cylinder model of wind chill are several degrees colder than those calculated from a facial cooling model. The latter was based on experiments with a heated model of a face in a wind tunnel. Wind chill has sometimes been modeled as the overall heat transfer from the surface of a cylinder in cross flow, but such models average the cooling over the whole surface and thus minimize the effect of local cooling on the upwind side, particularly at low wind speeds. In this paper, a vertical cylinder model of wind chill has been modified so that just the cooling of its windward side is considered. Wind chill equivalent temperatures calculated with this new model compare favorably with those calculated by the facial cooling model.

Chilling response of plants: importance of galactolipase, free fatty acids and free radicals.

PubMed

Kaniuga, Z

2008-03-01

The chilling response of plants is complex and based on the interplay of two important metabolic processes--lipolytic degradation of membrane lipids and a set of oxidative reactions leading to lipid peroxidation and membrane damage evoked in chilling-sensitive (CS) plants subjected to low temperature and light. The effects of chilling of detached leaves and intact plants differ and are often neglected during experiments. In closely-related species, the activity of several constitutive enzymes (i.e. superoxide dismutase, ascorbate peroxidase and glutathione reductase) appears to be higher in chilling-tolerant (CT) than in CS species; while in several native, closely-related CS species, lipid acyl hydrolase (galactolipase) activity is higher than in CT species. Moreover, in chilling-insensitive (CI) plants, galactolipase activity is very low and is neither activated by detachment of leaves nor under stress conditions in growing plants. Dark and low-temperature treatments of detached leaves of CS species and post-chilling recovery of growing plants in the light activate galactolipase, which is responsible for the release of free fatty acids (FFA), the main substrates of peroxidation by lipoxygenase and free radicals. In several CS species, increased galactolipase activity is an important factor contributing to chilling susceptibility. Thus, it seems likely that enhancement of chilling tolerance may be achieved by genetically suppressing galactolipase in order to reduce both the degradation of chloroplast lipids and the level of released FFA, and thereby avoiding the deleterious action of their peroxidation products on plant tissues.

Frequency of thermophilic Campylobacter in broiler chickens during industrial processing in a Southern Brazil slaughterhouse.

PubMed

Franchin, P R; Ogliari, P J; Batista, C R V

2007-04-01

1. The frequency of thermophilic Campylobacter spp. on broiler carcases was determined during processing in a Southern Brazil slaughterhouse. Samples were collected after defeathering, evisceration, water chilling and freezing. In addition, samples were obtained from the water of the chiller tank and from the surface of equipment in direct contact with the chicken. 2. Samples (335) were analysed and 71.3% were positive for Campylobacter. The frequency of Campylobacter spp. on carcases rinsed in BPW and skin samples from carcases was 49 of 72 (68.0%) after defeathering, 50 of 72 (69.4%) after evisceration, 61 of 72 (84.7%) after chilling, and 46 of 72 (63.9%) after freezing. Campylobacter was positive for 21 of 23 (91.3%) samples in the chilling water and for 12 of 24 (50.0%) samples on the table surface. 3. The frequency of qualitative analysis for Campylobacter spp. was reduced in frozen chickens, but not during the slaughtering process. The use of drinking water alone as a decontaminant to reduce the incidence of Campylobacter spp. during slaughter is therefore not sufficient. Furthermore, to ensure food safety, chickens must be cooked properly before consuming.

A retrospective study of artificial insemination of 251 mares using chilled and fixed time frozen-thawed semen.

PubMed

Crowe, C A M; Ravenhill, P J; Hepburn, R J; Shepherd, C H

2008-09-01

Historically, artificial insemination (AI) using frozen semen has been perceived to have poorer success rates and be more labour intensive than using chilled semen. A retrospective study was therefore conducted to compare the conception rate achieved by AI between chilled and frozen semen, using fixed time insemination protocols over 2 breeding seasons. Artificial insemination using chilled semen produces a higher conception rate than that achieved with frozen semen. Mares (n = 251) were inseminated with either chilled (n = 112) or frozen (n = 139) semen in the 2006 and 2007 northern hemisphere breeding season. Per rectum ultrasonography of the mare's reproductive tract determined the timing of insemination, and deslorelin acetate was used to induce ovulation. Chilled semen insemination was performed using a single preovulatory dose delivered into the uterine body. Frozen semen was administered as 2 doses (pre- and post ovulation) using a deep uterine insemination technique. Pregnancy was detected ultrasonographically at 15 days post insemination. Conception rates were compared using a Chi-squared test. Insemination with frozen semen produced a significantly (P = 0.022) higher seasonal conception rate (82.0%) than that achieved with chilled semen (69.6%). Insemination with frozen semen can achieve conception rates equal to those with chilled semen, enabling the mare owner a greater selection of stallions.

Two types of peak emotional responses to music: The psychophysiology of chills and tears

PubMed Central

Mori, Kazuma; Iwanaga, Makoto

2017-01-01

People sometimes experience a strong emotional response to artworks. Previous studies have demonstrated that the peak emotional experience of chills (goose bumps or shivers) when listening to music involves psychophysiological arousal and a rewarding effect. However, many aspects of peak emotion are still not understood. The current research takes a new perspective of peak emotional response of tears (weeping, lump in the throat). A psychophysiological experiment showed that self-reported chills increased electrodermal activity and subjective arousal whereas tears produced slow respiration during heartbeat acceleration, although both chills and tears induced pleasure and deep breathing. A song that induced chills was perceived as being both happy and sad whereas a song that induced tears was perceived as sad. A tear-eliciting song was perceived as calmer than a chill-eliciting song. These results show that tears involve pleasure from sadness and that they are psychophysiologically calming; thus, psychophysiological responses permit the distinction between chills and tears. Because tears may have a cathartic effect, the functional significance of chills and tears seems to be different. We believe that the distinction of two types of peak emotions is theoretically relevant and further study of tears would contribute to more understanding of human peak emotional response. PMID:28387335

Music chills: The eye pupil as a mirror to music's soul.

PubMed

Laeng, Bruno; Eidet, Lise Mette; Sulutvedt, Unni; Panksepp, Jaak

2016-08-01

This study evaluated whether music-induced aesthetic "chill" responses, which typically correspond to peak emotional experiences, can be objectively monitored by degree of pupillary dilation. Participants listened to self-chosen songs versus control songs chosen by other participants. The experiment included an active condition where participants made key presses to indicate when experiencing chills and a passive condition (without key presses). Chills were reported more frequently for self-selected songs than control songs. Pupil diameter was concurrently measured by an eye-tracker while participants listened to each of the songs. Pupil size was larger within specific time-windows around the chill events, as monitored by key responses, than in comparison to pupil size observed during 'passive' song listening. In addition, there was a clear relationship between pupil diameter within the chills-related time-windows during both active and passive conditions, thus ruling out the possibility that chills-related pupil dilations were an artifact of making a manual response. These findings strongly suggest that music chills can be visible in the moment-to-moment changes in the size of pupillary responses and that a neuromodulatory role of the central norepinephrine system is thereby implicated in this phenomenon. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Influence of climate change on the flowering of temperate fruit trees

NASA Astrophysics Data System (ADS)

Perez-Lopez, D.; Ruiz-Ramos, M.; Sánchez-Sánchez, E.; Centeno, A.; Prieto-Egido, I.; Lopez-de-la-Franca, N.

2012-04-01

It is well known that winter chilling is necessary for the flowering of temperate trees. The chilling requirement is a criterion for choosing a species or variety at a given location. Also chemistry products can be used for reducing the chilling-hours needs but make our production more expensive. This study first analysed the observed values of chilling hours for some representative agricultural locations in Spain for the last three decades and their projected changes under climate change scenarios. Usually the chilling is measured and calculated as chilling-hours, and different methods have been used to calculate them (e.g. Richarson et al., 1974 among others) according to the species considered. For our objective North Carolina method (Shaltout and Unrath, 1983) was applied for apples, Utah method (Richardson et al. 1974) for peach and grapevine and the approach used by De Melo-Abreu et al. (2004) for olive trees. The influence of climate change in temperate trees was studied by calculating projections of chilling-hours with climate data from Regional Climate Models (RCMs) at high resolution (25 km) from the European Project ENSEMBLES (http://www.ensembles-eu.org/). These projections will allow for analysing the modelled variations of chill-hours between 2nd half of 20C and 1st half of 21C at the study locations.

Pre-rigor temperature control of Chinese yellow cattle carcasses to 12-18 °C during chilling improves beef tenderness.

PubMed

Liu, Yuqing; Mao, Yanwei; Zhang, Yimin; Liang, Rongrong; Wang, Renhuan; Zhu, Lixian; Meng, Xianyong; Luo, Xin

2015-02-01

This study evaluates the effects of pre-rigor temperature control on quality traits of Chinese yellow cattle M. longissimus lumborum (LL). One stepwise chilling (SC) treatment was used on one half-carcass, involved a fast chilling (-11 ± 1 °C;0.5 m/s) for 2h, then the refrigeration was stopped to hold a core temperature of 12-18 °C until 10h postmortem, followed by a 1 ± 1 °C chilling (0.5 m/s) to 48h postmortem. The other half-carcass was conventional chilled at 1 ± 1 °C (0.5 m/s) until 48h as control chilling (CC). Quality attributes were evaluated at 1, 7 and 14 days. The SC treatment resulted in decreased WBSF and increased myofibril fragmentation index compared with control. SC-treated LL at 7d postmortem had a lower WBSF than those of CC-treated at 14d. This pre-rigor temperature controlled chilling is a realistic alternative for the beef industry in China to ensure adequate tenderness and shorten aging time.

RNA helicase-like protein as an early regulator of transcription factors for plant chilling and freezing tolerance

PubMed Central

Gong, Zhizhong; Lee, Hojoung; Xiong, Liming; Jagendorf, André; Stevenson, Becky; Zhu, Jian-Kang

2002-01-01

Susceptibility to chilling injury prevents the cultivation of many important crops and limits the extended storage of horticultural commodities. Although freezing tolerance is acquired through cold-induced gene expression changes mediated in part by the CBF family of transcriptional activators, whether plant chilling resistance or sensitivity involves the CBF genes is not known. We report here that an Arabidopsis thaliana mutant impaired in the cold-regulated expression of CBF genes and their downstream target genes is sensitive to chilling stress. Expression of CBF3 under a strong constitutive promoter restores chilling resistance to the mutant plants. The mutated gene was cloned and found to encode a nuclear localized RNA helicase. Our results identify a regulator of CBF genes, and demonstrate the importance of gene regulation and the CBF transcriptional activators in plant chilling resistance. PMID:12165572

Effects of chilling on protein synthesis in tomato suspension cultures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matadial, B.; Pauls, K.P.

The effect of chilling on cell growth, cell viability, protein content and protein composition in suspension cultures of L. esculentum and L. hirsutum was investigated. Cell growth for both species was arrested at 2{degrees}C but when cultures were transferred to 25{degree}C cell growth resumed. There was no difference in viability between control and chilled cultures of L. esculentum, however, L. hirsutum control cultures exhibited larger amounts of Fluorescein Diacetate induced fluorescence than chilled cultures. {sup 35}S-methionine incorporation into proteins was 2.5-2 times higher in L. hirsutum than in L. esculentum. Quantitative and qualitative differences, in {sup 35}S-methionine labelled proteins, betweenmore » chilled and control cultures were observed by SDS-PAGE and fluorography. Protein content in chilled cultures decreased over time but then increased when cultures were transferred to 25{degrees}C.« less

Effect of alternating day and night temperature on short day-induced bud set and subsequent bud burst in long days in Norway spruce

PubMed Central

Olsen, Jorunn E.; Lee, YeonKyeong; Junttila, Olavi

2014-01-01

Young seedlings of the conifer Norway spruce exhibit short day (SD)-induced cessation of apical growth and bud set. Although different, constant temperatures under SD are known to modulate timing of bud set and depth of dormancy with development of deeper dormancy under higher compared to lower temperature, systematic studies of effects of alternating day (DT) and night temperatures (NT) are limited. To shed light on this, seedlings of different provenances of Norway spruce were exposed to a wide range of DT-NT combinations during bud development, followed by transfer to forcing conditions of long days (LD) and 18°C, directly or after different periods of chilling. Although no specific effect of alternating DT/NT was found, the results demonstrate that the effects of DT under SD on bud set and subsequent bud break are significantly modified by NT in a complex way. The effects on bud break persisted after chilling. Since time to bud set correlated with the daily mean temperature under SD at DTs of 18 and 21°C, but not a DT of 15°C, time to bud set apparently also depend on the specific DT, implying that the effect of NT depends on the actual DT. Although higher temperature under SD generally results in later bud break after transfer to forcing conditions, the fastest bud flush was observed at intermediate NTs. This might be due to a bud break-hastening chilling effect of intermediate compared to higher temperatures, and delayed bud development to a stage where bud burst can occur, under lower temperatures. Also, time to bud burst in un-chilled seedlings decreased with increasing SD-duration, suggesting that bud development must reach a certain stage before the processes leading to bud burst are initiated. The present results also indicate that low temperature during bud development had a larger effect on the most southern compared to the most northern provenance studied. Decreasing time to bud burst was observed with increasing northern latitude of origin in un-chilled as well as chilled plants. In conclusion, being a highly temperature-dependent process, bud development is strongly delayed by low temperature, and the effects of DT is significantly modified by NT in a complex manner. PMID:25538722

Comparative Evaluation of Conventional and Accelerated Castings on Marginal Fit and Surface Roughness

PubMed Central

Jadhav, Vivek Dattatray; Motwani, Bhagwan K.; Shinde, Jitendra; Adhapure, Prasad

2017-01-01

Aims: The aim of this study was to evaluate the marginal fit and surface roughness of complete cast crowns made by a conventional and an accelerated casting technique. Settings and Design: This study was divided into three parts. In Part I, the marginal fit of full metal crowns made by both casting techniques in the vertical direction was checked, in Part II, the fit of sectional metal crowns in the horizontal direction made by both casting techniques was checked, and in Part III, the surface roughness of disc-shaped metal plate specimens made by both casting techniques was checked. Materials and Methods: A conventional technique was compared with an accelerated technique. In Part I of the study, the marginal fit of the full metal crowns as well as in Part II, the horizontal fit of sectional metal crowns made by both casting techniques was determined, and in Part III, the surface roughness of castings made with the same techniques was compared. Statistical Analysis Used: The results of the t-test and independent sample test do not indicate statistically significant differences in the marginal discrepancy detected between the two casting techniques. Results: For the marginal discrepancy and surface roughness, crowns fabricated with the accelerated technique were significantly different from those fabricated with the conventional technique. Conclusions: Accelerated casting technique showed quite satisfactory results, but the conventional technique was superior in terms of marginal fit and surface roughness. PMID:29042726

Effects of chilling rate and spray-chilling on weight loss and tenderness in beef strip loin steaks.

PubMed

Prado, C S; de Felício, P E

2010-10-01

We evaluated the effects of chilling rate and the use of a spray-chilling system on the weight loss by evaporation on carcasses. We also evaluated the effects on meat purge in vacuum package, cooking losses, and on parameters related to the tenderness of strip loin steaks (M. longissimus lumborum). Forty non-castrated males of approximately 12 months old, finished in feed-lot were harvested in 16 Montana cattle (a composite breed), and 24 SimmentalxNellore crossbred cattle. After bleeding, the bodies were electrically stimulated and assigned to one of the four treatments: conventional air-chilling (CAC), conventional spray-chilling (CSC), slow air-chilling (SAC), and slow spray-chilling (SSC). Strip loin steaks (M. longissimus lumborum) of approximately 2.5 cm thick were removed, vacuum packed and aged for 7, 14, 30 or 60 days. Samples were analyzed for sarcomere length, myofibrillar fragmentation index, Warner-Bratzler shear force, and weight losses by purge and cooking. Spraying was efficient in reducing weight loss by evaporation (P<0.05). Effects of treatments and aging period on purge losses were observed, where samples from sprayed carcasses or aged cuts showed higher losses. Cooking losses were not affected either by spraying or aging. The slow chilling, with or without spraying, was more efficient in producing strip loin steaks with lower average shear force and longer sarcomere. The myofibrillar fragmentation index increased with aging time, but was not affected by carcasses spraying. Copyright (c) 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

Tympanic temperature versus temporal temperature in patients with pyrexia and chills

PubMed Central

Yang, Wen-Chieh; Kuo, Huang-Tsung; Lin, Ching-Hsiao; Wu, Kang-Hsi; Chang, Yu-Jun; Chen, Chun-Yu; Wu, Han-Ping

2016-01-01

Abstract Accurate body temperature (BT) measurement is critical for immediate and correct estimation of core BT; measurement of changes in BT can provide physicians the initial information for selecting appropriate diagnostic approach and may prevent unnecessary diagnostic investigation. This study aimed to assess differences in tympanic and temporal temperatures among patients with fever in different conditions, especially in those with and without chills. This prospective study included patients from the emergency department between 2011 and 2012. All temperature measurements were obtained using tympanic thermometers and infrared skin thermometers. Differences in tympanic and temporal temperatures were analyzed according to 6 age groups, 5 ambient temperature groups, and 6 tympanic and temporal temperature subgroups. General linear model analysis and receiver operating characteristic curve analysis were used to estimate the differences in mean tympanic and temporal temperatures. Of the 710 patients enrolled, 246 had tympanic temperature more than 38.0°C, including 46 with chills (18.7%). Fourteen patients (3.0%) had chills and tympanic temperature less than 38°C. In the tympanic temperature subgroup of 39.0 to less than 39.5°C, approximately one-third of the patients had chills (32.3%). In the tympanic temperature subgroup of 38.0 to less than 39.0°C, the tympanic temperature was 0.4°C higher than the temporal temperature in patients without chills and 0.9°C higher in patients with chills. In the tympanic temperature subgroup of 39.0°C or more, tympanic temperature was 0.7°C higher than temporal temperature in patients without chills and 0.8°C higher in patients with chills. Temporal thermometer is more reliable in the age group of less than 1 year and 18 to less than 65 years. When the patients show tympanic temperature range of 38.0 to less than 39.0°C, 0.4°C should be added for patients without chills and 0.9°C for patients with chills to obtain core temperature. However, in patients with tympanic temperature of 39.0°C or more, 0.7°C to 0.8°C should be added, regardless of the presence of chills. PMID:27858893

Insights into the Molecular Events That Regulate Heat-Induced Chilling Tolerance in Citrus Fruits.

PubMed

Lafuente, María T; Establés-Ortíz, Beatriz; González-Candelas, Luis

2017-01-01

Low non-freezing temperature may cause chilling injury (CI), which is responsible for external quality deterioration in many chilling-sensitive horticultural crops. Exposure of chilling-sensitive citrus cultivars to non-lethal high-temperature conditioning may increase their chilling tolerance. Very little information is available about the molecular events involved in such tolerance. In this work, the molecular events associated with the low temperature tolerance induced by heating Fortune mandarin, which is very sensitive to chilling, for 3 days at 37°C prior to cold storage is presented. A transcriptomic analysis reveals that heat-conditioning has an important impact favoring the repression of genes in cold-stored fruit, and that long-term heat-induced chilling tolerance is an active process that requires activation of transcription factors involved in transcription initiation and of the WRKY family. The analysis also shows that chilling favors degradation processes, which affect lipids and proteins, and that the protective effect of the heat-conditioning treatment is more likely to be related to the repression of the genes involved in lipid degradation than to the modification of fatty acids unsaturation, which affects membrane permeability. Another major factor associated with the beneficial effect of the heat treatment on reducing CI is the regulation of stress-related proteins. Many of the genes that encoded such proteins are involved in secondary metabolism and in oxidative stress-related processes.

Changes in Isozyme Profiles of Catalase, Peroxidase, and Glutathione Reductase during Acclimation to Chilling in Mesocotyls of Maize Seedlings.

PubMed Central

Anderson, M. D.; Prasad, T. K.; Stewart, C. R.

1995-01-01

The response of antioxidants to acclimation and chilling in various tissues of dark-grown maize (Zea mays L.) seedlings was examined in relation to chilling tolerance and protection from chilling-induced oxidative stress. Chilling caused an accumulation of H2O2 in both the coleoptile + leaf and the mesocotyl (but not roots), and acclimation prevented this accumulation. None of the antioxidant enzymes were significantly affected by acclimation or chilling in the coleoptile + leaf or root. However, elevated levels of glutathione in acclimated seedlings may contribute to an enhanced ability to scavenge H2O2 in the coleoptile + leaf. In the mesocotyl (visibly most susceptible to chilling), catalase3 was elevated in acclimated seedlings and may represent the first line of defense from mitochondria-generated H2O2. Nine of the most prominent peroxidase isozymes were induced by acclimation, two of which were located in the cell wall, suggesting a role in lignification. Lignin content was elevated in mesocotyls of acclimated seedlings, likely improving the mechanical strength of the mesocotyl. One cytosolic glutathione reductase isozyme was greatly decreased in acclimated seedlings, whereas two others were elevated, possibly resulting in improved effectiveness of the enzyme at low temperature. When taken together, these responses to acclimation illustrate the potential ways in which chilling tolerance may be improved in preemergent maize seedlings. PMID:12228666

Preharvest temperature affects chilling injury in dessert bananas during storage.

PubMed

Bugaud, Christophe; Joannès-Dumec, Charlène; Louisor, Jacques; Tixier, Philippe; Salmon, Frédéric

2016-05-01

The effect of temperature on chilling injury during fruit growth was studied in a new banana hybrid CIRAD925 in which seasonal variability in chilling susceptibility was observed when fruits were stored at 13 °C. The relationship between the response to chilling (presence/absence) and the temperature during banana fruit growth was examined with a logistic regression model. An explanatory variable XN , P was defined as the mean temperature during a period, expressed in weeks, which began N week(s) after flowering and lasted P week(s). The model was calibrated with 143 bunches with a green life of 30 ± 5 days and validated with 156 bunches grown in six plots under different growing conditions. Chilling injury was best predicted by the mean temperature during the period beginning 1 week after flowering and lasting 5 weeks (X1,5 ). Above a mean temperature of 24.1 °C in the period concerned, banana fruits had a 95% probability of chilling injury at 13 °C. Below a temperature of 23.4 °C, banana fruits only had a 5% probability of chilling injury. The results provide a tool to predict chilling susceptibility in banana fruit whatever the thermal conditions in tropical regions. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Bud burst timing in Picea abies seedlings as affected by temperature during dormancy induction and mild spells during chilling.

PubMed

Granhus, Aksel; Fløistad, Inger Sundheim; Søgaard, Gunnhild

2009-04-01

In trees adapted to cold climates, conditions during autumn and winter may influence the subsequent timing of bud burst and hence tree survival during early spring frosts. We tested the effects of two temperatures during dormancy induction and mild spells (MS) during chilling on the timing of bud burst in three Picea abies (L.) Karst. provenances (58-66 degrees N). One-year-old seedlings were induced to become dormant at temperatures of 12 or 21 degrees C applied during 9 weeks of short days (12-h photoperiod). The seedlings were then moved to cold storage and given either continuous chilling at 0.7 degrees C (control), or chilling interrupted by one 14-day MS at either 8 or 12 degrees C. Interruptions with MS were staggered throughout the 175-day chilling period, resulting in 10 MS differing in date of onset. Subsets of seedlings were moved to forcing conditions (12-h photoperiod, 12 degrees C) throughout the chilling period, to assess dormancy status at different timings of the MS treatment. Finally, after 175 days of chilling, timing of bud burst was assessed in a 24-h photoperiod at 12 degrees C (control and MS-treated seedlings). The MS treatment did not significantly affect days to bud burst when given early (after 7-35 chilling days). When MS was given after 49 chilling days or later, the seedlings burst bud earlier than the controls, and the difference increased with increasing length of the chilling period given before the MS. The 12 degrees C MS treatment was more effective than the 8 degrees C MS treatment, and the difference remained constant after the seedlings had received 66 or more chilling days before the MS treatment was applied. In all provenances, a constant temperature of 21 degrees C during dormancy induction resulted in more dormant seedlings (delayed bud burst) than a constant temperature of 12 degrees C, but this did not delay the response to the MS treatment.

Baby oil therapy for uremic pruritus in haemodialysis patients.

PubMed

Lin, Tzu-Chen; Lai, Yu-Hung; Guo, Su-Er; Liu, Chin-Fang; Tsai, Jer-Chia; Guo, How-Ran; Hsu, Hsin-Tien

2012-01-01

The purpose of this study was to investigate the effectiveness of chilled/un-chilled baby oil therapy for treating uremic pruritus in haemodialysis patients. Uremic pruritus affects 50-90% of haemodialysis patients, which makes it one of the most common medical problems in this population. Pruritus can cause skin infection, desquamation, pathological skin change, sleep disorder, anxiety, depression and social dysfunction. A prospective, pretest-post-test quasi-experimental design was used. Haemodialysis patients with uremic pruritus were recruited and randomly assigned to one of three groups: experimental group 1 (chilled baby oil treatment; n = 30), experimental group 2 (un-chilled baby oil treatment; n = 31) and a control group (routine care only; n = 32). Participants in experimental group 1 and experimental group 2 were treated with chilled and un-chilled baby oil, respectively, for 15 minutes at least once daily for three weeks. The control group received no intervention other than standard care. Data collection included demographic data and itch severity. Medical records were also reviewed. The baseline characteristics of subjects in this study were as follows: 59% were male, mean age was 61·88 (SD 12·7) years, mean duration of haemodialysis was 5·31 years, mean duration of uremic pruritus was 40·58 (SD 37·8) months and mean intensity of uremic pruritus was mild. The anti-pruritic effects were significantly larger in subjects treated with either chilled or un-chilled baby oil than in those who received routine care. Anti-pruritic effects did not significantly differ between experimental group 1 and experimental group 2. The study confirmed that, for relieving pruritus in haemodialysis patients, either chilled or un-chilled baby oil is as effective as moisturising lotions and cooling soothing agents. Applying baby oil is a simple, safe, inexpensive and easily administered treatment for itchy skin in haemodialysis patients. By preventing or reducing uremic pruritus, baby oil treatment may also improve quality of life in this patient group. © 2011 Blackwell Publishing Ltd.

α-Tocopherol Is Essential for Acquired Chill-Light Tolerance in the Cyanobacterium Synechocystis sp. Strain PCC 6803▿ †

PubMed Central

Yang, Yang; Yin, Chuntao; Li, Weizhi; Xu, Xudong

2008-01-01

Unlike Escherichia coli, the cyanobacterium Synechocystis sp. strain PCC 6803 is insensitive to chill (5°C) in the dark but rapidly losses viability when exposed to chill in the light (100 μmol photons m−2 s−1). Preconditioning at a low temperature (15°C) greatly enhances the chill-light tolerance of Synechocystis sp. strain PCC 6803. This phenomenon is called acquired chill-light tolerance (ACLT). Preconditioned wild-type cells maintained a substantially higher level of α-tocopherol after exposure to chill-light stress. Mutants unable to synthesize α-tocopherol, such as slr1736, slr1737, slr0089, and slr0090 mutants, almost completely lost ACLT. When exposed to chill without light, these mutants showed no or a slight difference from the wild type. When complemented, the slr0089 mutant regained its ACLT. Copper-regulated expression of slr0090 from PpetE controlled the level of α-tocopherol and ACLT. We conclude that α-tocopherol is essential for ACLT of Synechocystis sp. strain PCC 6803. The role of α-tocopherol in ACLT may be based largely on a nonantioxidant activity that is not possessed by other tocopherols or pathway intermediates. PMID:18165303

The capacity to maintain ion and water homeostasis underlies interspecific variation in Drosophila cold tolerance

PubMed Central

MacMillan, Heath A.; Andersen, Jonas L.; Davies, Shireen A.; Overgaard, Johannes

2015-01-01

Many insects, including Drosophila, succumb to the physiological effects of chilling at temperatures well above those causing freezing. Low temperature causes a loss of extracellular ion and water homeostasis in such insects, and chill injuries accumulate. Using an integrative and comparative approach, we examined the role of ion and water balance in insect chilling susceptibility/ tolerance. The Malpighian tubules (MT), of chill susceptible Drosophila species lost [Na+] and [K+] selectivity at low temperatures, which contributed to a loss of Na+ and water balance and a deleterious increase in extracellular [K+]. By contrast, the tubules of chill tolerant Drosophila species maintained their MT ion selectivity, maintained stable extracellular ion concentrations, and thereby avoided injury. The most tolerant species were able to modulate ion balance while in a cold-induced coma and this ongoing physiological acclimation process allowed some individuals of the tolerant species to recover from chill coma during low temperature exposure. Accordingly, differences in the ability to maintain homeostatic control of water and ion balance at low temperature may explain large parts of the wide intra- and interspecific variation in insect chilling tolerance. PMID:26678786

Cold Stress Tolerance in Psychrotolerant Soil Bacteria and Their Conferred Chilling Resistance in Tomato (Solanum lycopersicum Mill.) under Low Temperatures

PubMed Central

Subramanian, Parthiban; Kim, Kiyoon; Krishnamoorthy, Ramasamy; Mageswari, Anbazhagan; Selvakumar, Gopal; Sa, Tongmin

2016-01-01

The present work aimed to study the culturable diversity of psychrotolerant bacteria persistent in soil under overwintering conditions, evaluate their ability to sustain plant growth and alleviate chilling stress in tomato. Psychrotolerant bacteria were isolated from agricultural field soil samples colleced during winter and then used to study chilling stress alleviation in tomato plants (Solanum lycopersicum cv Mill). Selective isolation after enrichment at 5°C yielded 40 bacterial isolates. Phylogenetic studies indicated their distribution in genera Arthrobacter, Flavimonas, Flavobacterium, Massilia, Pedobacter and Pseudomonas. Strains OS211, OB146, OB155 and OS261 consistently improved germination and plant growth when a chilling stress of 15°C was imposed and therefore were selected for pot experiments. Tomato plants treated with the selected four isolates exhibited significant tolerance to chilling as observed through reduction in membrane damage and activation of antioxidant enzymes along with proline synthesis in the leaves when exposed to chilling temperature conditions (15°C). Psychrotolerant physiology of the isolated bacteria combined with their ability to improve germination, plant growth and induce antioxidant capacity in tomato plants can be employed to protect plants against chilling stress. PMID:27580055

An investigation of the effect of rapid slurry chilling on blown pack spoilage of vacuum-packaged beef primals.

PubMed

Reid, R; Fanning, S; Whyte, P; Kerry, J; Bolton, D

2017-02-01

The aim of this study was to investigate if rapid slurry chilling would retard or prevent blown pack spoilage (BPS) of vacuum-packaged beef primals. Beef primals were inoculated with Clostridium estertheticum subspp. estertheticum (DSMZ 8809), C. estertheticum subspp. laramenise (DSMZ 14864) and C. gasigenes (DSMZ 12272), and vacuum-packaged with and without heat shrinkage (90°C for 3 s). These packs were then subjected to immediate chilling in an ice slurry or using conventional blast chilling systems and stored at 2°C for up to 100 days. The onset and progress of BPS was monitored using the following scale; 0-no gas bubbles in drip; 1-gas bubbles in drip; 2-loss of vacuum; 3-'blown'; 4-presence of sufficient gas inside the packs to produce pack distension and 5-tightly stretched, 'overblown' packs/packs leaking. Rapid slurry chilling (as compared to conventional chilling) did not significantly affect (P > 0.05) the time to the onset or progress of BPS. It was therefore concluded that rapid chilling of vacuum-packaged beef primals, using an ice slurry system, may not be used as a control intervention to prevent or retard blown pack spoilage. This study adds to our growing understanding of blown pack spoilage of vacuum-packaged beef primals and suggests that rapid chilling of vacuum-packaged beef primals is not a control option for the beef industry. The results suggest that neither eliminating the heat shrinkage step nor rapid chilling of vacuum-packaged beef retard the time to blown pack spoilage. © 2016 The Society for Applied Microbiology.

Clay Portrait Boxes

ERIC Educational Resources Information Center

Wilbert, Nancy Corrigan

2009-01-01

In an attempt to incorporate sculptural elements into her ceramics program, the author decided to try direct plaster casting of the face to make a plaster mold for clay. In this article, the author shares an innovative ceramics lesson that teaches students in making plaster casts and casting the face in clay. This project gives students the…

40 CFR 1065.215 - Pressure transducers, temperature sensors, and dewpoint sensors.

Code of Federal Regulations, 2014 CFR

2014-07-01

... sensors, such as resistive temperature detectors (RTDs). (d) Pressure. Pressure transducers must be... chilled-surface hygrometers, which include chilled mirror detectors and chilled surface acoustic wave (SAW) detectors. For other applications, we recommend thin-film capacitance sensors. You may use other dewpoint...

40 CFR 1065.215 - Pressure transducers, temperature sensors, and dewpoint sensors.

Code of Federal Regulations, 2013 CFR

2013-07-01

... sensors, such as resistive temperature detectors (RTDs). (d) Pressure. Pressure transducers must be... chilled-surface hygrometers, which include chilled mirror detectors and chilled surface acoustic wave (SAW) detectors. For other applications, we recommend thin-film capacitance sensors. You may use other dewpoint...

40 CFR 1065.215 - Pressure transducers, temperature sensors, and dewpoint sensors.

Code of Federal Regulations, 2011 CFR

2011-07-01

... sensors, such as resistive temperature detectors (RTDs). (d) Pressure. Pressure transducers must be... chilled-surface hygrometers, which include chilled mirror detectors and chilled surface acoustic wave (SAW) detectors. For other applications, we recommend thin-film capacitance sensors. You may use other dewpoint...

40 CFR 1065.215 - Pressure transducers, temperature sensors, and dewpoint sensors.

Code of Federal Regulations, 2012 CFR

2012-07-01

... sensors, such as resistive temperature detectors (RTDs). (d) Pressure. Pressure transducers must be... chilled-surface hygrometers, which include chilled mirror detectors and chilled surface acoustic wave (SAW) detectors. For other applications, we recommend thin-film capacitance sensors. You may use other dewpoint...

Producing Foils From Direct Cast Titanium Alloy Strip

NASA Technical Reports Server (NTRS)

Stuart, T. A.; Gaspar, T. A.; Sukonnik, I. M.; Semiatan, S. L.; Batawi, E.; Peters, J. A.; Fraser, H. L.

1996-01-01

This research was undertaken to demonstrate the feasibility of producing high-quality, thin-gage, titanium foil from direct cast titanium strip. Melt Overflow Rapid Solidification Technology (MORST) was used to cast several different titanium alloys into 500 microns thick strip, 10 cm wide and up to 3 m long. The strip was then either ground, hot pack rolled or cold rolled, as appropriate, into foil. Gamma titanium aluminide (TiAl) was cast and ground to approximately 100 microns thick foil and alpha-2 titanium aluminide (Ti3AI) was cast and hot pack rolled to approximately 70 microns thick foil. CP Ti, Ti6Al2Sn4Zr2Mo, and Ti22AI23Nb (Orthorhombic), were successfully cast and cold-rolled into good quality foil (less than 125 microns thick). The foils were generally fully dense with smooth surfaces, had fine, uniform microstructures, and demonstrated mechanical properties equivalent to conventionally produced titanium. By eliminating many manufacturing steps, this technology has the potential to produce thin gage, titanium foil with good engineering properties at significantly reduced cost relative to conventional ingot metallurgy processing.

[A quantitative risk assessment model of salmonella on carcass in poultry slaughterhouse].

PubMed

Zhang, Yu; Chen, Yuzhen; Hu, Chunguang; Zhang, Huaning; Bi, Zhenwang; Bi, Zhenqiang

2015-05-01

To construct a quantitative risk assessment model of salmonella on carcass in poultry slaughterhouse and to find out effective interventions to reduce salmonella contamination. We constructed a modular process risk model (MPRM) from evisceration to chilling in Excel Sheet using the data of the process parameters in poultry and the Salmomella concentration surveillance of Jinan in 2012. The MPRM was simulated by @ risk software. The concentration of salmonella on carcass after chilling was 1.96MPN/g which was calculated by model. The sensitive analysis indicated that the correlation coefficient of the concentration of salmonella after defeathering and in chilling pool were 0.84 and 0.34,which were the primary factors to the concentration of salmonella on carcass after chilling. The study provided a quantitative assessment model structure for salmonella on carcass in poultry slaughterhouse. The risk manager could control the contamination of salmonella on carcass after chilling by reducing the concentration of salmonella after defeathering and in chilling pool.

Evaluation of marginal and internal gaps of metal ceramic crowns obtained from conventional impressions and casting techniques with those obtained from digital techniques.

PubMed

Rai, Rathika; Kumar, S Arun; Prabhu, R; Govindan, Ranjani Thillai; Tanveer, Faiz Mohamed

2017-01-01

Accuracy in fit of cast metal restoration has always remained as one of the primary factors in determining the success of the restoration. A well-fitting restoration needs to be accurate both along its margin and with regard to its internal surface. The aim of the study is to evaluate the marginal fit of metal ceramic crowns obtained by conventional inlay casting wax pattern using conventional impression with the metal ceramic crowns obtained by computer-aided design and computer-aided manufacturing (CAD/CAM) technique using direct and indirect optical scanning. This in vitro study on preformed custom-made stainless steel models with former assembly that resembles prepared tooth surfaces of standardized dimensions comprised three groups: the first group included ten samples of metal ceramic crowns fabricated with conventional technique, the second group included CAD/CAM-milled direct metal laser sintering (DMLS) crowns using indirect scanning, and the third group included DMLS crowns fabricated by direct scanning of the stainless steel model. The vertical marginal gap and the internal gap were evaluated with the stereomicroscope (Zoomstar 4); post hoc Turkey's test was used for statistical analysis. One-way analysis of variance method was used to compare the mean values. Metal ceramic crowns obtained from direct optical scanning showed the least marginal and internal gap when compared to the castings obtained from inlay casting wax and indirect optical scanning. Indirect and direct optical scanning had yielded results within clinically acceptable range.

Acute antibody-directed myostatin inhibition attenuates disuse muscle atrophy and weakness in mice.

PubMed

Murphy, Kate T; Cobani, Vera; Ryall, James G; Ibebunjo, Chikwendu; Lynch, Gordon S

2011-04-01

Counteracting the atrophy of skeletal muscle associated with disuse has significant implications for minimizing the wasting and weakness in plaster casting, joint immobilization, and other forms of limb unloading, with relevance to orthopedics, sports medicine, and plastic and reconstructive surgery. We tested the hypothesis that antibody-directed myostatin inhibition would attenuate the loss of muscle mass and functional capacity in mice during 14 or 21 days of unilateral hindlimb casting. Twelve-week-old C57BL/10 mice were subjected to unilateral hindlimb plaster casting or served as controls. Mice received subcutaneous injections of saline or a mouse chimera of anti-human myostatin antibody (PF-354, 10 mg/kg; n = 6-9) on days 0 and 7 and were tested for muscle function on day 14, or were treated on days 0, 7, and 14 and tested for muscle function on day 21. Hindlimb casting reduced muscle mass, fiber size, and function of isolated soleus and extensor digitorum longus (EDL) muscles (P < 0.05). PF-354 attenuated the loss of muscle mass, fiber size, and function with greater effects after 14 days than after 21 days of casting, when wasting and weakness had plateaued (P < 0.05). Antibody-directed myostatin inhibition therefore attenuated the atrophy and loss of functional capacity in muscles from mice subjected to unilateral hindlimb casting with reductions in muscle size and strength being most apparent during the first 14 days of disuse. These findings highlight the therapeutic potential of antibody-directed myostatin inhibition for disuse atrophy especially within the first 2 wk of disuse.

Stimulus-triggered enhancement of chilling tolerance in zebrafish embryos

PubMed Central

Szabó, Katalin; Budai, Csilla; Losonczi, Eszter; Bernáth, Gergely; Csenki-Bakos, Zsolt; Urbányi, Béla; Pribenszky, Csaba; Horváth, Ákos; Cserepes, Judit

2017-01-01

Background Cryopreservation of zebrafish embryos is still an unsolved problem despite market demand and massive efforts to preserve genetic variation among numerous existing lines. Chilled storage of embryos might be a step towards developing successful cryopreservation, but no methods to date have worked. Methods In the present study, we applied a novel strategy to improve the chilling tolerance of zebrafish embryos by introducing a preconditioning hydrostatic pressure treatment to the embryos. In our experiments, 26-somites and Prim-5 stage zebrafish embryos were chilled at 0°C for 24 hours after preconditioning. Embryo survival rate, ability to reach maturation and fertilizing capacity were tested. Results Our results indicate that applied preconditioning technology made it possible for the chilled embryos to develop normally until maturity, and to produce healthy offspring as normal, thus passing on their genetic material successfully. Treated embryos had a significantly higher survival and better developmental rate, moreover the treated group had a higher ratio of normal morphology during continued development. While all controls from chilled embryos died by 30 day-post-fertilization, the treated group reached maturity (~90–120 days) and were able to reproduce, resulting in offspring in expected quantity and quality. Conclusions Based on our results, we conclude that the preconditioning technology represents a significant improvement in zebrafish embryo chilling tolerance, thus enabling a long-time survival. Furthermore, as embryonic development is arrested during chilled storage this technology also provides a solution to synchronize or delay the development. PMID:28166301

The roles of call wall invertase inhibitor in regulating chilling tolerance in tomato.

PubMed

Xu, Xiao-Xia; Hu, Qin; Yang, Wan-Nian; Jin, Ye

2017-11-09

Hexoses are important metabolic signals that respond to abiotic and biotic stresses. Cold stress adversely affects plant growth and development, limiting productivity. The mechanism by which sugars regulate plant cold tolerance remains elusive. We examined the function of INVINH1, a cell wall invertase inhibitor, in tomato chilling tolerance. Cold stress suppressed the transcription of INVINH1 and increased that of cell wall invertase genes, Lin6 and Lin8 in tomato seedlings. Silencing INVINH1 expression in tomato increased cell wall invertase activity and enhanced chilling tolerance. Conversely, transgenic tomatoes over-expressing INVINH1 showed reduced cell wall invertase activity and were more sensitive to cold stress. Chilling stress increased glucose and fructose levels, and the hexoses content increased or decreased by silencing or overexpression INVINH1. Glucose applied in vitro masked the differences in chilling tolerance of tomato caused by the different expressions of INVINH1. The repression of INVINH1 or glucose applied in vitro regulated the expression of C-repeat binding factors (CBFs) genes. Transcript levels of NCED1, which encodes 9-cisepoxycarotenoid dioxygenase (NCED), a key enzyme in the biosynthesis of abscisic acid, were suppressed by INVINH1 after exposure to chilling stress. Meanwhile, application of ABA protected plant from chilling damage caused by the different expression of INVINH1. In tomato, INVINH1 plays an important role in chilling tolerance by adjusting the content of glucose and expression of CBFs.

21 CFR 890.5940 - Chilling unit.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Chilling unit. 890.5940 Section 890.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5940 Chilling unit. (a...

21 CFR 890.5940 - Chilling unit.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Chilling unit. 890.5940 Section 890.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5940 Chilling unit. (a...

21 CFR 890.5940 - Chilling unit.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Chilling unit. 890.5940 Section 890.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5940 Chilling unit. (a...

21 CFR 890.5940 - Chilling unit.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Chilling unit. 890.5940 Section 890.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5940 Chilling unit. (a...

21 CFR 890.5940 - Chilling unit.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Chilling unit. 890.5940 Section 890.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5940 Chilling unit. (a...

Genome-Wide Association Mapping Reveals Multiple QTLs Governing Tolerance Response for Seedling Stage Chilling Stress in Indica Rice.

PubMed

Pandit, Elssa; Tasleem, Swaleha; Barik, Saumya R; Mohanty, Durga P; Nayak, Deepak K; Mohanty, Shakti P; Das, Sujata; Pradhan, Sharat K

2017-01-01

Rice crop is sensitive to cold stress at seedling stage. A panel of population representing 304 shortlisted germplasm lines was studied for seedling stage chilling tolerance in indica rice. Six phenotypic classes were exposed to six low temperature stress regimes under control phenotyping facility to investigate response pattern. A panel of 66 genotypes representing all phenotypic classes was used for ensuring genetic diversity, population structure and association mapping for the trait using 58 simple sequence repeat (SSR) and 2 direct trait linked markers. A moderate level of genetic diversity was detected in the panel population for the trait. Deviation of Hardy-Weinberg's expectation was detected in the studied population using Wright's F statistic. The panel showed 30% variation among population and 70% among individuals. The entire population was categorized into three sub-populations through STRUCTURE analysis. This revealed tolerance for the trait had a common primary ancestor for each sub-population with few admix individuals. The panel population showed the presence of many QTLs for cold stress tolerance in the individuals representing like genome-wide expression of the trait. Nineteen SSR markers were significantly associated at chilling stress of 8°C to 4°C for 7-21 days duration. Thus, the primers linked to the seedling stage cold tolerance QTLs namely qCTS9, qCTS-2, qCTS6.1, qSCT2, qSCT11, qSCT1a, qCTS-3.1, qCTS11.1, qCTS12.1, qCTS-1b, and CTB2 need to be pyramided for development of strongly chilling tolerant variety.

Genome-Wide Association Mapping Reveals Multiple QTLs Governing Tolerance Response for Seedling Stage Chilling Stress in Indica Rice

PubMed Central

Pandit, Elssa; Tasleem, Swaleha; Barik, Saumya R.; Mohanty, Durga P.; Nayak, Deepak K.; Mohanty, Shakti P.; Das, Sujata; Pradhan, Sharat K.

2017-01-01

Rice crop is sensitive to cold stress at seedling stage. A panel of population representing 304 shortlisted germplasm lines was studied for seedling stage chilling tolerance in indica rice. Six phenotypic classes were exposed to six low temperature stress regimes under control phenotyping facility to investigate response pattern. A panel of 66 genotypes representing all phenotypic classes was used for ensuring genetic diversity, population structure and association mapping for the trait using 58 simple sequence repeat (SSR) and 2 direct trait linked markers. A moderate level of genetic diversity was detected in the panel population for the trait. Deviation of Hardy-Weinberg's expectation was detected in the studied population using Wright's F statistic. The panel showed 30% variation among population and 70% among individuals. The entire population was categorized into three sub-populations through STRUCTURE analysis. This revealed tolerance for the trait had a common primary ancestor for each sub-population with few admix individuals. The panel population showed the presence of many QTLs for cold stress tolerance in the individuals representing like genome-wide expression of the trait. Nineteen SSR markers were significantly associated at chilling stress of 8°C to 4°C for 7–21 days duration. Thus, the primers linked to the seedling stage cold tolerance QTLs namely qCTS9, qCTS-2, qCTS6.1, qSCT2, qSCT11, qSCT1a, qCTS-3.1, qCTS11.1, qCTS12.1, qCTS-1b, and CTB2 need to be pyramided for development of strongly chilling tolerant variety. PMID:28487705

Incidence of chilling injury in fresh-cut 'Kent' mangoes

USDA-ARS?s Scientific Manuscript database

The preferred storage temperature for fresh-cut fruits in terms of visual quality retention is around 5 °C, which is considered to be a chilling temperature for chilling sensitive tropical fruits like mango (Mangifera indica L.). Changes in visual and compositional quality factors, aroma volatile pr...

Increasing chilling reduces heat requirement for floral budbreak in peach

USDA-ARS?s Scientific Manuscript database

Response to chilling temperatures is a critical factor in the suitability of peach [Prunus persica (L.) Batsch] cultivars to moderate climates such as in the southeastern United States. Time of bloom depends on the innate chilling requirement of the cultivar as well as the timing and quantity of co...

Historical trends in chill hour accumulation and peach bud response to hydrogen cyanamide

USDA-ARS?s Scientific Manuscript database

Long held records for (low) chill hour accumulation have recently been broken several times in the southeastern US peach (Prunus persica) production areas. Long term historical average chill hour accumulation through February 15th in middle Georgia has dropped significantly over the last 15 years. T...

75 FR 3903 - Agency Information Collection Activities; Submission to OMB for Review and Approval; Comment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-25

...; Comment Request; GreenChill Advanced Refrigeration Partnership AGENCY: Environmental Protection Agency...Chill Advanced Refrigeration Partnership. ICR numbers: EPA ICR No. 2349.01, OMB Control No. 2060-New... is consolidated in 40 CFR part 9. Abstract: The GreenChill Advanced Refrigeration Partnership...

Impact of eliminating the carcass chilling step in the production of pre-cooked chicken breast meat

USDA-ARS?s Scientific Manuscript database

Pre-cooked chicken meat provides convenience to consumers and is growing in popularity globally. Poultry meat destined for pre-cooked meat products typically undergoes chilling on the carcass skeletal frame and deboning before cooking. However, compared to immersion chilling with antimicrobial, cook...

9 CFR 381.66 - Temperatures and chilling and freezing procedures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Temperatures and chilling and freezing procedures. 381.66 Section 381.66 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... Procedures § 381.66 Temperatures and chilling and freezing procedures. (a) General. Temperatures and...

Aesthetic Chills: Knowledge-Acquisition, Meaning-Making, and Aesthetic Emotions

PubMed Central

Schoeller, Felix; Perlovsky, Leonid

2016-01-01

This article addresses the relation between aesthetic emotions, knowledge-acquisition, and meaning-making. We briefly review theoretical foundations and present experimental data related to aesthetic chills. These results suggest that aesthetic chills are inhibited by exposing the subject to an incoherent prime prior to the chill-eliciting stimulation and that a meaningful prime makes the aesthetic experience more pleasurable than a neutral or an incoherent one. Aesthetic chills induced by narrative structures seem to be related to the pinnacle of the story, to have a significant calming effect and subjects describe a strong empathy for the characters. We discuss the relation between meaning-making and aesthetic emotions at the psychological, physiological, narratological, and mathematical levels and propose a series of hypotheses to be tested in future research. PMID:27540366

Heat Transfer Characteristics of Fan Coil Unit (FCU) Under The Effect of Chilled Water Volume Flowrate

NASA Astrophysics Data System (ADS)

Wijaya Sunu, Putu; Anakottapary, Daud Simon; Mulawarman, A. A. N. B.; Cipta Santosa, I. D. M.; Putu Sastra Negara, I.

2018-01-01

In this paper, the volume flowrate of chilled water in the water chiller simulation apparatus was optimized using experimental studied. The experimental analysis was performed on the fan coil unit (FCU) of the system. The chilled water flows in tube side and the air as a hot fluid flows throughout the tube and fin of FCU. The thermal performance and analysis of the heat transfer is examined using various chilled water flowrate e.g. 11, 12, 13, 14, 15 lpm. The effect of the flowrate to the important parameter such as LMTD temperature, heat absorb used for investigate the heat transfer characteristics. The result showed that the heat transfer characteristics has been increased with the increased of chilled water volume flowrate.

Challenges in predicting climate change impacts on pome fruit phenology

NASA Astrophysics Data System (ADS)

Darbyshire, Rebecca; Webb, Leanne; Goodwin, Ian; Barlow, E. W. R.

2014-08-01

Climate projection data were applied to two commonly used pome fruit flowering models to investigate potential differences in predicted full bloom timing. The two methods, fixed thermal time and sequential chill-growth, produced different results for seven apple and pear varieties at two Australian locations. The fixed thermal time model predicted incremental advancement of full bloom, while results were mixed from the sequential chill-growth model. To further investigate how the sequential chill-growth model reacts under climate perturbed conditions, four simulations were created to represent a wider range of species physiological requirements. These were applied to five Australian locations covering varied climates. Lengthening of the chill period and contraction of the growth period was common to most results. The relative dominance of the chill or growth component tended to predict whether full bloom advanced, remained similar or was delayed with climate warming. The simplistic structure of the fixed thermal time model and the exclusion of winter chill conditions in this method indicate it is unlikely to be suitable for projection analyses. The sequential chill-growth model includes greater complexity; however, reservations in using this model for impact analyses remain. The results demonstrate that appropriate representation of physiological processes is essential to adequately predict changes to full bloom under climate perturbed conditions with greater model development needed.

Reestablishment of ion homeostasis during chill-coma recovery in the cricket Gryllus pennsylvanicus

PubMed Central

MacMillan, Heath A.; Williams, Caroline M.; Staples, James F.; Sinclair, Brent J.

2012-01-01

The time required to recover from cold-induced paralysis (chill-coma) is a common measure of insect cold tolerance used to test central questions in thermal biology and predict the effects of climate change on insect populations. The onset of chill-coma in the fall field cricket (Gryllus pennsylvanicus, Orthoptera: Gryllidae) is accompanied by a progressive drift of Na+ and water from the hemolymph to the gut, but the physiological mechanisms underlying recovery from chill-coma are not understood for any insect. Using a combination of gravimetric methods and atomic absorption spectroscopy, we demonstrate that recovery from chill-coma involves a reestablishment of hemolymph ion content and volume driven by removal of Na+ and water from the gut. Recovery is associated with a transient elevation of metabolic rate, the time span of which increases with increasing cold exposure duration and closely matches the duration of complete osmotic recovery. Thus, complete recovery from chill-coma is metabolically costly and encompasses a longer period than is required for the recovery of muscle potentials and movement. These findings provide evidence that physiological mechanisms of hemolymph ion content and volume regulation, such as ion-motive ATPase activity, are instrumental in chill-coma recovery and may underlie natural variation in insect cold tolerance. PMID:23184963

Phosphatidylglycerol and Chilling Sensitivity in Plants

PubMed Central

Roughan, P. Grattan

1985-01-01

The hypothesis that molecular species of thylakoid phosphatidylglycerol containing two saturated fatty acids (disaturated phosphatidylglycerol) confer chilling sensitivity upon plants was tested by analyzing the fatty acid composition of phosphatidylglycerols isolated from leaves of a range of plants expected to have different sensitivities to chilling temperatures. `Saturated' fatty acids (palmitate plus stearate plus hexadeca-trans-3-enoate) as a proportion of total phosphatidylglycerol fatty acids varied from 51 to 80 mole per cent in the plants analyzed but appeared to be rigidly fixed for a given plant species, being unaffected by leaf maturity or by environment. Hexadeca-trans-3-enoate occurred only at the sn-2 position, whereas C-18 fatty acids occurred only at the sn-1 position of thylakoid phosphatidylglycerol. Therefore, the proportion of disaturated molecular species could be predicted accurately from the total fatty acids of phosphatidylglycerol. Disaturated molecular species accounted for <25% of the total phosphatidylglycerol from leaves of chilling-resistant plants and for 50 to 60% of the phosphatidylglycerol in leaves from some of the most chilling-sensitive plants. However, not all chilling-sensitive plants contained high proportions of disaturated phosphatidylglycerol; solanaceous and other 16:3-plants and C4 grasses may be important exceptions. Nonetheless, proportions of disaturated phosphatidylglycerol increased concomitantly with increasing chilling sensitivity of plants within a genus. PMID:16664127

Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling.

PubMed

Diao, Qian-Nan; Song, Yong-Jun; Shi, Dong-Mei; Qi, Hong-Yan

Polyamines (PAs) and nitric oxide (NO) are vital signals in modulating plant response to abiotic stress. However, to our knowledge, studies on the relationship between NO and PAs in response to cold stress in tomato are limited. Accordingly, in this study, we investigated the effects of putrescine (Put) and spermidine (Spd) on NO generation and the function of Spd-induced NO in the tolerance of tomato seedling under chilling stress. Spd increased NO release via the nitric oxide synthase (NOS)-like and nitrate reductase (NR) enzymatic pathways in the seedlings, whereas Put had no such effect. Moreover, H 2 O 2 might act as an upstream signal to stimulate NO production. Both exogenous NO donor (sodium nitroprusside (SNP)) and Spd enhanced chilling tolerance in tomato, thereby protecting the photosynthetic system from damage. Compared to chilling treatment alone, Spd enhanced the gene expressions of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and their enzyme activities in tomato leaves. However, a scavenger or inhibitor of NO abolished Spd-induced chilling tolerance and blocked the increased expression and activity due to Spd of these antioxidant enzymes in tomato leaves under chilling stress. The results showed that NO induced by Spd plays a crucial role in tomato's response to chilling stress.

Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling*#

PubMed Central

Diao, Qian-Nan; Song, Yong-Jun; Shi, Dong-Mei; Qi, Hong-Yan

2016-01-01

Polyamines (PAs) and nitric oxide (NO) are vital signals in modulating plant response to abiotic stress. However, to our knowledge, studies on the relationship between NO and PAs in response to cold stress in tomato are limited. Accordingly, in this study, we investigated the effects of putrescine (Put) and spermidine (Spd) on NO generation and the function of Spd-induced NO in the tolerance of tomato seedling under chilling stress. Spd increased NO release via the nitric oxide synthase (NOS)-like and nitrate reductase (NR) enzymatic pathways in the seedlings, whereas Put had no such effect. Moreover, H2O2 might act as an upstream signal to stimulate NO production. Both exogenous NO donor (sodium nitroprusside (SNP)) and Spd enhanced chilling tolerance in tomato, thereby protecting the photosynthetic system from damage. Compared to chilling treatment alone, Spd enhanced the gene expressions of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and their enzyme activities in tomato leaves. However, a scavenger or inhibitor of NO abolished Spd-induced chilling tolerance and blocked the increased expression and activity due to Spd of these antioxidant enzymes in tomato leaves under chilling stress. The results showed that NO induced by Spd plays a crucial role in tomato’s response to chilling stress. PMID:27921397

Impact of broiler processing scalding and chilling profiles on carcass and breast meat yield.

PubMed

Buhr, R J; Walker, J M; Bourassa, D V; Caudill, A B; Kiepper, B H; Zhuang, H

2014-06-01

The effect of scalding and chilling procedures was evaluated on carcass and breast meat weight and yield in broilers. On 4 separate weeks (trials), broilers were subjected to feed withdrawal, weighed, and then stunned and bled in 4 sequential batches (n = 16 broilers/batch, 64 broilers/trial). In addition, breast skin was collected before scalding, after scalding, and after defeathering for proximate analysis. Each batch of 16 carcasses was subjected to either hard (60.0°C for 1.5 min) or soft (52.8°C for 3 min) immersion scalding. Following defeathering and evisceration, 8 carcasses/batch were air-chilled (0.5°C, 120 min, 86% RH) and 8 carcasses/batch were immersion water-chilled (water and ice 0.5°C, 40 min). Carcasses were reweighed individually following evisceration and following chilling. Breast meat was removed from the carcass and weighed within 4 h postmortem. There were significant (P < 0.05) differences among the trials for all weights and yields; however, postfeed withdrawal shackle weight and postscald-defeathered eviscerated weights did not differ between the scalding and chilling treatments. During air-chilling all carcasses lost weight, resulting in postchill carcass yield of 73.0% for soft-scalded and 71.3% for hard-scalded carcasses, a difference of 1.7%. During water-chilling all carcasses gained weight, resulting in heavier postchill carcass weights (2,031 g) than for air-chilled carcasses (1,899 g). Postchill carcass yields were correspondingly higher for water-chilled carcasses, 78.2% for soft-scalded and 76.1% for hard-scalded carcasses, a difference of 2.1%. Only in trials 1 and 4 was breast meat yield significantly lower for hard-scalded, air-chilled carcasses (16.1 and 17.5%) than the other treatments. Proximate analysis of skin sampled after scalding or defeathering did not differ significantly in moisture (P = 0.2530) or lipid (P = 0.6412) content compared with skin sampled before scalding. Skin protein content was significantly higher (P < 0.05) for prescald and soft-scalded skin samples than for hard-scalded or soft or hard-scalded skin samples after defeathering. The hard-scalding method used in this experiment did not result in increased skin lipid loss either before or after defeathering. Poultry Science Association Inc.

Direct metal laser sintering: a digitised metal casting technology.

PubMed

Venkatesh, K Vijay; Nandini, V Vidyashree

2013-12-01

Dental technology is undergoing advancements at a fast pace and technology is being imported from various other fields. One such imported technology is direct metal laser sintering technology for casting metal crowns. This article will discuss the process of laser sintering for making metal crowns and fixed partial dentures with a understanding of their pros and cons.

Elevated temperature strengthening of a melt spun austenitic steel by TiB2

NASA Technical Reports Server (NTRS)

Michal, G. M.; Glasgow, T. K.; Moore, T. J.

1986-01-01

Mechanical properties of an iron-based alloy containing (by wt pct) 33Ni, 2Al, 6Ti, and 2B (resulting in an alloy containing 10 vol pct TiB2) were evaluated by hardness and tensile testing. The alloy was cast as a ribbon using a dual 'free-jet' variation of Jech et al. (1984) method of chill-block melt-spinning against a copper wheel; to simulate thermal cycles the alloy ribbon would experience during compaction into shapes, various segments of the ribbon were annealed under a vacuum at temperatures ranging from 500 to 1150 C. The results show that maximum strengths at 650 and 760 C were developed in ribbons annealed at 1100 C; in these ribbons an optimal combination of grain coarsening with minimum TiB2 particle growth was observed. However, the elevated-temperature strength of the TiB2-strengthened alloy under optimal annealing conditions was poorer than that of conventional iron-based superalloys strengthened by gamma-prime precipitates.

Rapid solidification of high-conductivity copper alloys. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Bloom, Theodore Atlas

1989-01-01

The main objective was to develop improved copper alloys of high strength and high thermal and electric conductivity. Chill block melt spinning was used to produce binary alloys of Cu-Cr and Cu-Zr, and ternary alloys of Cu-Cr-Ag. By quenching from the liquid state, up to 5 atomic percent of Cr and Zr were retained in metastable extended solid solution during the rapid solidification process. Eutectic solidification was avoided and the full strengthening benefits of the large volume fraction of precipitates were realized by subsequent aging treatment. The very low solid solubility of Cr and Zr in Cu result in a high conductivity Cu matrix strengthened by second phase precipitates. Tensile properties on as-cast and aged ribbons were measured at room and elevated temperatures. Precipitate coarsening of Cr in Cu was studied by changes in electrical resistance during aging. X-ray diffraction was used to measure the lattice parameter and the degree of supersaturation of the matrix. The microstructures were characterized by optical and electron microscopy.

The Relationship between the Expression of Ethylene-Related Genes and Papaya Fruit Ripening Disorder Caused by Chilling Injury

PubMed Central

Zou, Yuan; Zhang, Lin; Rao, Shen; Zhu, Xiaoyang; Ye, Lanlan; Chen, Weixin; Li, Xueping

2014-01-01

Papaya (Carica papaya L.) is sensitive to low temperature and easy to be subjected to chilling injury, which causes fruit ripening disorder. This study aimed to investigate the relationship between the expression of genes related to ethylene and fruit ripening disorder caused by chilling injury. Papaya fruits were firstly stored at 7°C and 12°C for 25 and 30 days, respectively, then treated with exogenous ethylene and followed by ripening at 25°C for 5 days. Chilling injury symptoms such as pulp water soaking were observed in fruit stored at 7°C on 20 days, whereas the coloration and softening were completely blocked after 25 days, Large differences in the changes in the expression levels of twenty two genes involved in ethylene were seen during 7°C-storage with chilling injury. Those genes with altered expression could be divided into three groups: the group of genes that were up-regulated, including ACS1/2/3, EIN2, EIN3s/EIL1, CTR1/2/3, and ERF1/3/4; the group of genes that were down-regulated, including ACO3, ETR1, CTR4, EBF2, and ERF2; and the group of genes that were un-regulated, including ACO1/2, ERS, and EBF1. The results also showed that pulp firmness had a significantly positive correlation with the expression of ACS2, ACO1, CTR1/4, EIN3a/b, and EBF1/2 in fruit without chilling injury. This positive correlation was changed to negative one in fruit after storage at 7°C for 25 days with chilling injury. The coloring index displayed significantly negative correlations with the expression levels of ACS2, ACO1/2, CTR4, EIN3a/b, ERF3 in fruit without chilling injury, but these correlations were changed into the positive ones in fruit after storage at 7°C for 25 days with chilling injury. All together, these results indicate that these genes may play important roles in the abnormal softening and coloration with chilling injury in papaya. PMID:25542021

Chilling and Drought Stresses in Crop Plants: Implications, Cross Talk, and Potential Management Opportunities

PubMed Central

Hussain, Hafiz A.; Hussain, Saddam; Khaliq, Abdul; Ashraf, Umair; Anjum, Shakeel A.; Men, Shengnan; Wang, Longchang

2018-01-01

Plants face a combination of different abiotic stresses under field conditions which are lethal to plant growth and production. Simultaneous occurrence of chilling and drought stresses in plants due to the drastic and rapid global climate changes, can alter the morphological, physiological and molecular responses. Both these stresses adversely affect the plant growth and yields due to physical damages, physiological and biochemical disruptions, and molecular changes. In general, the co-occurrence of chilling and drought combination is even worse for crop production rather than an individual stress condition. Plants attain various common and different physiological and molecular protective approaches for tolerance under chilling and drought stresses. Nevertheless, plant responses to a combination of chilling and drought stresses are unique from those to individual stress. In the present review, we summarized the recent evidence on plant responses to chilling and drought stresses on shared as well as unique basis and tried to find a common thread potentially underlying these responses. We addressed the possible cross talk between plant responses to these stresses and discussed the potential management strategies for regulating the mechanisms of plant tolerance to drought and/or chilling stresses. To date, various novel approaches have been tested in minimizing the negative effects of combine stresses. Despite of the main improvements there is still a big room for improvement in combination of drought and chilling tolerance. Thus, future researches particularly using biotechnological and molecular approaches should be carried out to develop genetically engineered plants with enhanced tolerance against these stress factors. PMID:29692787

Chilling and heat requirements for leaf unfolding in European beech and sessile oak populations at the southern limit of their distribution range.

PubMed

Dantec, Cécile F; Vitasse, Yann; Bonhomme, Marc; Louvet, Jean-Marc; Kremer, Antoine; Delzon, Sylvain

2014-11-01

With global warming, an advance in spring leaf phenology has been reported worldwide. However, it is difficult to forecast phenology for a given species, due to a lack of knowledge about chilling requirements. We quantified chilling and heat requirements for leaf unfolding in two European tree species and investigated their relative contributions to phenological variations between and within populations. We used an extensive database containing information about the leaf phenology of 14 oak and 10 beech populations monitored over elevation gradients since 2005. In parallel, we studied the various bud dormancy phases, in controlled conditions, by regularly sampling low- and high-elevation populations during fall and winter. Oak was 2.3 times more sensitive to temperature for leaf unfolding over the elevation gradient and had a lower chilling requirement for dormancy release than beech. We found that chilling is currently insufficient for the full release of dormancy, for both species, at the lowest elevations in the area studied. Genetic variation in leaf unfolding timing between and within oak populations was probably due to differences in heat requirement rather than differences in chilling requirement. Our results demonstrate the importance of chilling for leaf unfolding in forest trees and indicate that the advance in leaf unfolding phenology with increasing temperature will probably be less pronounced than forecasted. This highlights the urgent need to determine experimentally the interactions between chilling and heat requirements in forest tree species, to improve our understanding and modeling of changes in phenological timing under global warming.

Effect of morphological changes in feather follicles of chicken carcasses after defeathering and chilling on the degree of skin contamination by Campylobacter species

PubMed Central

LATT, Khin Maung; URATA, Ayaka; SHINKI, Taisuke; SASAKI, Satomi; TANIGUCHI, Takako; MISAWA, Naoaki

2017-01-01

Campylobacter jejuni and C. coli are the leading causes of enteric infections in many developed countries. Healthy chickens are considered to act as reservoirs of campylobacters, as the organisms colonize the intestinal tract. Once infected birds enter a processing plant, contamination of chicken carcasses with campylobacters occurs over the entire skin during defeathering and evisceration due to leakage of crop and/or intestinal contents. Although the role of feather follicles in the contamination of chicken carcasses by campylobacters during processing is still debatable, it has been considered that the microorganisms would be entrapped and retained in the follicles due to the morphological changes resulting from defeathering and chilling. In the present study, we observed the morphology of feather follicles in chicken carcasses after defeathering and chilling. A total of 3,133 feather follicles were examined for morphological changes before and after chilling. Shortly after defeathering, most (91.5%) of the follicles were closed, whereas after chilling they were either closed (85.5%) or open (6%), although a small proportion of enlarged follicles became smaller or closed (2.6%). Moreover, 5.9% of the follicles that were slightly open became further enlarged after chilling. Furthermore, the proportion of enlarged feather follicles that became closed after chilling showed no discernible relationship with the degree of campylobacter contamination in different areas of the carcass skin, suggesting that campylobacters may not be confined to feather follicles as a result of the morphological changes attributable to defeathering and chilling. PMID:29151444

Identification of dehydrin-like proteins responsive to chilling in floral buds of blueberry (Vaccinium, section Cyanococcus).

PubMed

Muthalif, M M; Rowland, L J

1994-04-01

The level of three major polypeptides of 65, 60, and 14 kD increased in response to chilling unit accumulation in floral buds of a woody perennial, blueberry (Vaccinium, section Cynaococcus). The level of the polypeptides increased most dramatically within 300 h of chilling and decreased to the prechilling level with the initiation of budbreak. Cold-hardiness levels were assessed for dormant buds of Vaccinium corymbosum and Vaccinium ashei after different chilling treatments until the resumption of growth. These levels coincided with the level of the chilling-responsive polypeptides. Like some other previously described cold-induced proteins in annual plants, the level of the chilling-induced polypeptides also increased in leaves in response to cold treatment; the chilling-induced polypeptides were heat stable, resisting aggregation after incubation at 95 degrees C for 15 min. By fractionating bud proteins first by isoelectric point (pI) and then by molecular mass, the pI values of the 65- and 60-kD polypeptides were found to be 7.5 to 8.0 and the pI value of the 14-kD polypeptide was judged to be 8.5. Purification of the 65- and 60-kD polypeptides, followed by digestion with endoproteinase Lys-C and sequencing of selected fragments, revealed similarities in amino acid composition between the 65- and 60-kD polypeptides and dehydrins. Indeed, antiserum to the lysine-rich consensus sequence EKKGIMDKIKEKLPG of dehydrin proteins cross-reacted to all three of the major chilling-responsive polypeptides of blueberry, identifying these as dehydrins or dehydrin-like proteins.

Identification of dehydrin-like proteins responsive to chilling in floral buds of blueberry (Vaccinium, section Cyanococcus).

PubMed Central

Muthalif, M M; Rowland, L J

1994-01-01

The level of three major polypeptides of 65, 60, and 14 kD increased in response to chilling unit accumulation in floral buds of a woody perennial, blueberry (Vaccinium, section Cynaococcus). The level of the polypeptides increased most dramatically within 300 h of chilling and decreased to the prechilling level with the initiation of budbreak. Cold-hardiness levels were assessed for dormant buds of Vaccinium corymbosum and Vaccinium ashei after different chilling treatments until the resumption of growth. These levels coincided with the level of the chilling-responsive polypeptides. Like some other previously described cold-induced proteins in annual plants, the level of the chilling-induced polypeptides also increased in leaves in response to cold treatment; the chilling-induced polypeptides were heat stable, resisting aggregation after incubation at 95 degrees C for 15 min. By fractionating bud proteins first by isoelectric point (pI) and then by molecular mass, the pI values of the 65- and 60-kD polypeptides were found to be 7.5 to 8.0 and the pI value of the 14-kD polypeptide was judged to be 8.5. Purification of the 65- and 60-kD polypeptides, followed by digestion with endoproteinase Lys-C and sequencing of selected fragments, revealed similarities in amino acid composition between the 65- and 60-kD polypeptides and dehydrins. Indeed, antiserum to the lysine-rich consensus sequence EKKGIMDKIKEKLPG of dehydrin proteins cross-reacted to all three of the major chilling-responsive polypeptides of blueberry, identifying these as dehydrins or dehydrin-like proteins. PMID:8016270

Effect of morphological changes in feather follicles of chicken carcasses after defeathering and chilling on the degree of skin contamination by Campylobacter species.

PubMed

Latt, Khin Maung; Urata, Ayaka; Shinki, Taisuke; Sasaki, Satomi; Taniguchi, Takako; Misawa, Naoaki

2018-01-01

Campylobacter jejuni and C. coli are the leading causes of enteric infections in many developed countries. Healthy chickens are considered to act as reservoirs of campylobacters, as the organisms colonize the intestinal tract. Once infected birds enter a processing plant, contamination of chicken carcasses with campylobacters occurs over the entire skin during defeathering and evisceration due to leakage of crop and/or intestinal contents. Although the role of feather follicles in the contamination of chicken carcasses by campylobacters during processing is still debatable, it has been considered that the microorganisms would be entrapped and retained in the follicles due to the morphological changes resulting from defeathering and chilling. In the present study, we observed the morphology of feather follicles in chicken carcasses after defeathering and chilling. A total of 3,133 feather follicles were examined for morphological changes before and after chilling. Shortly after defeathering, most (91.5%) of the follicles were closed, whereas after chilling they were either closed (85.5%) or open (6%), although a small proportion of enlarged follicles became smaller or closed (2.6%). Moreover, 5.9% of the follicles that were slightly open became further enlarged after chilling. Furthermore, the proportion of enlarged feather follicles that became closed after chilling showed no discernible relationship with the degree of campylobacter contamination in different areas of the carcass skin, suggesting that campylobacters may not be confined to feather follicles as a result of the morphological changes attributable to defeathering and chilling.

Prosthetic management of malpositioned implant using custom cast abutment

PubMed Central

Chatterjee, Aishwarya; Ragher, Mallikarjuna; Patil, Sanket; Chatterjee, Debopriya; Dandekeri, Savita; Prabhu, Vishnu

2015-01-01

Two cases are reported with malpositioned implants. Both the implants were placed 6–7 months back. They had osseointegrated well with the surrounding bone. However, they presented severe facial inclination. Case I was restored with custom cast abutment with an auto polymerizing acrylic gingival veneer. Case II was restored with custom cast UCLA type plastic implant abutment. Ceramic was directly fired on the custom cast abutments. The dual treatment strategy resulted in functional and esthetic restorations despite facial malposition of the implants. PMID:26538957

Accuracy of cast posts fabricated by the direct and the indirect techniques.

PubMed

Rayyan, Mohammad R; Aldossari, Roa'a A; Alsadun, Sarah F; Hijazy, Fatimah R

2016-09-01

Patterns for custom cast posts and cores can be fabricated either by the direct or the indirect technique. Which technique is more accurate is unknown. The purpose of this in vitro study was to investigate the effect of pattern fabrication technique on the accuracy of post fit. Ten intact extracted premolar teeth with a single canal and similar dimensions received root canal treatment. The teeth were sectioned 2 mm above the cementoenamel junction. A total of 20 cast post and core patterns, 2 for each tooth, were fabricated, 10 with the direct technique and 10 with the indirect technique. Patterns were cast to produce 20 cast post and cores. Each tooth was scanned using a microcomputed tomography (μCT) system with a resolution of 14.5 μm, once with the post of the direct technique and once with the post of the indirect technique. Ct analyzer software was used to calculate the overall space between the post and canal walls and the space areas in 3 different standardized sections. The Student paired t test was used to determine any significant difference in the scores of the groups. The overall space between the canal walls and posts made with the direct technique ranged between 7.86 and 17.39 mm(3), with a mean value of 12.25 mm(3), whereas with the indirect technique, the space ranged between 6.68 and 18.02 mm(3), with a mean of 11.92 mm(3). No significant differences were found between the results of either technique (P>.05). Within the limitations of this study, neither the indirect nor direct pattern fabrication technique influenced the accuracy of post fitting. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Salmonella recovery following air chilling for matched neck-skin and whole carcass sampling methodologies

USDA-ARS?s Scientific Manuscript database

The prevalence and serogroups of Salmonella recovered following air chilling were determined for both enriched neck skin and matching enriched whole carcass samples. Commercially processed and eviscerated carcasses were air chilled to 4C before removing the neck skin (8.3 g) and stomaching in 83 mL...

Tomato flavor changes at chilling and non-chilling temperatures as influenced by controlled atmospheres

USDA-ARS?s Scientific Manuscript database

Postharvest temperatures recommended as safe to avoid chilling injury (CI) based on lack of visible symptoms suppress tomato aroma development. We investigated how temperatures at or above the putative CI threshold of 12.5°C affected aroma of pink ‘Tasti Lee’ tomatoes and if controlled atmosphere (C...

Tomato chilling injury threshold defined by the volatile profiles of pink harvested tomato fruit

USDA-ARS?s Scientific Manuscript database

Fresh tomato fruit show visible symptoms of chilling injury (CI) when stored at temperatures lower than the reported chilling threshold of 12.5°C. However, their sensitivity has been reported to decrease as they ripen. Volatile profiles change during ripening and are affected by physiological change...

Localization, characterization and candidate gene discovery for genes controlling dormancy, chilling requirement, bloom time, and heat requirement in Prunus species.

USDA-ARS?s Scientific Manuscript database

Perennial fruiting trees require sustained exposure to low, near freezing, temperatures before vigorous floral and vegetative bud break is possible after the resumption of warm temperatures in the spring. The depth of dormancy, duration of chilling required (the chilling requirement, CR) blooming da...

How does music arouse "chills"? Investigating strong emotions, combining psychological, physiological, and psychoacoustical methods.

PubMed

Grewe, Oliver; Nagel, Frederik; Kopiez, Reinhard; Altenmüller, Eckart

2005-12-01

Music can arouse ecstatic "chill" experiences defined as "goose pimples" and as "shivers down the spine." We recorded chills both via subjects' self-reports and physiological reactions, finding that they do not occur in a reflex-like manner, but as a result of attentive, experienced, and conscious musical enjoyment.

9 CFR 381.66 - Temperatures and chilling and freezing procedures.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Temperatures and chilling and freezing... Procedures § 381.66 Temperatures and chilling and freezing procedures. (a) General. Temperatures and... temperature is reduced to 40 °F. or less, as provided in paragraph (b)(2) of this section unless such poultry...

9 CFR 381.66 - Temperatures and chilling and freezing procedures.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Temperatures and chilling and freezing... Procedures § 381.66 Temperatures and chilling and freezing procedures. (a) General. Temperatures and... temperature is reduced to 40 °F. or less, as provided in paragraph (b)(2) of this section unless such poultry...

9 CFR 381.66 - Temperatures and chilling and freezing procedures.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Temperatures and chilling and freezing... Procedures § 381.66 Temperatures and chilling and freezing procedures. (a) General. Temperatures and... temperature is reduced to 40 °F. or less, as provided in paragraph (b)(2) of this section unless such poultry...

Diversity of low chill peaches from Asia, Brasil, Europe and the USA

USDA-ARS?s Scientific Manuscript database

One hundred fifty-five peach (Prunus persica) cultivars, from Asia, Brazil, Europe, and the USA, were examined using eleven SSRs to study the genetic relationships among low chill as compared to high chill peach germplasm. Data was analyzed by NTSYSpc to form a similarity matrix using Nei and Li’s ...

Chilling-induced tomato flavor loss is associated with altered volatile synthesis and transient changes in DNA methylation

USDA-ARS?s Scientific Manuscript database

Commercial tomatoes are widely perceived by consumers as lacking flavor. A major part of that problem is a postharvest handling system that chills fruit. Low-temperature storage is widely used to slow ripening and reduce decay. However, chilling results in loss of flavor. Flavor-associated volatiles...

Chilling Stress Upregulates α-Linolenic Acid-Oxidation Pathway and Induces Volatiles of C6 and C9 Aldehydes in Mango Fruit.

PubMed

Sivankalyani, Velu; Maoz, Itay; Feygenberg, Oleg; Maurer, Dalia; Alkan, Noam

2017-01-25

Mango-fruit storage period and shelf life are prolonged by cold storage. However, chilling temperature induces physiological and molecular changes, compromising fruit quality. In our previous transcriptomic study of mango fruit, cold storage at suboptimal temperature (5 °C) activated the α-linolenic acid metabolic pathway. To evaluate changes in fruit quality during chilling, we analyzed mango "Keitt" fruit peel volatiles. GC-MS analysis revealed significant modulations in fruit volatiles during storage at suboptimal temperature. Fewer changes were seen in response to the time of storage. The mango volatiles related to aroma, such as δ-3-carene, (Z)-β-ocimene, and terpinolene, were downregulated during the storage at suboptimal temperature. In contrast, C 6 and C 9 aldehydes and alcohols-α-linolenic acid derivatives 1-hexanal, (Z)-3-hexenal, (Z)-3-hexenol, (E)-2-hexenal, and nonanal-were elevated during suboptimal-temperature storage, before chilling-injury symptoms appeared. Detection of those molecules before chilling symptoms could lead to a new agro-technology to avoid chilling injuries and maintain fruit quality during cold storage at the lowest possible temperature.

Chilled water study EEAP program for Walter Reed Army Medical Center. Book 1. Final Submission

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-02-01

The Energy Engineering Analysis Program (EEAP) Study for Walter Reed Army Medical Center (WRAMC) was to provide a thorough examination of the central chilled water plants on site. WRAMC is comprised of seventy-one (71) buildings located on a 113-acre site in Washington, D.C. There are two (2) central chilled water plants (Buildings 48 and 49) each with a primary chilled water distribution system. In addition to the two (2) central plants, three (3) buildings utilize their own independent chillers. Two (2) of the independent chillers (Buildings 7 and T-2), one of which is inoperative (T-2), are smaller air-cooled units, whilemore » the third (Building 54) has a 1,900-ton chilled water plant comprised of three (3) centrifugal chillers. Of the two (2) central chilled water plants, Building 48 houses six (6) chillers totalling 7,080 tons of cooling and Building 49 houses one (1) chiller with 660 tons of cooling. The total chiller cooling capacity available on site is 9,840 tons.« less

Changes in visual quality, physiological and biochemical parameters assessed during the postharvest storage at chilling or non-chilling temperatures of three sweet basil (Ocimum basilicum L.) cultivars.

PubMed

Fratianni, Florinda; Cefola, Maria; Pace, Bernardo; Cozzolino, Rosaria; De Giulio, Beatrice; Cozzolino, Autilia; d'Acierno, Antonio; Coppola, Raffaele; Logrieco, Antonio Francesco; Nazzaro, Filomena

2017-08-15

Leaves of three different sweet basil (Ocimum basilicum L.) cultivars (Italico a foglia larga, Cammeo, and Italiano classico) packed in macro-perforated polyethylene bags were stored at chilling (4°C) or non-chilling temperature (12°C) for 9days. During storage, visual quality, physiological (respiration rate, ethylene production, ammonium content) and chemical (antioxidant activity, total polyphenols and polyphenol profile) parameters were measured. Detached leaves stored at chilling temperature showed visual symptoms related to chilling injury, while ethylene production and ammonium content resulted associated to cultivar sensibility to damage at low temperature. Storage at 4°C caused a depletion in polyphenols content and antioxidant capability, which was preserved at 12°C. Regarding the polyphenols profile, stressful storage conditions did not enhance the phenolic metabolism. However, leaves stored at 12°C did not loss a significant amount of metabolites respect to fresh leaves, suggesting the possibility to extend the storability after the expiration date, for a possible recovery of bioactive compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of future warming on winter chilling in Australia.

PubMed

Darbyshire, Rebecca; Webb, Leanne; Goodwin, Ian; Barlow, E W R

2013-05-01

Increases in temperature as a result of anthropogenically generated greenhouse gas (GHG) emissions are likely to impact key aspects of horticultural production. The potential effect of higher temperatures on fruit and nut trees' ability to break winter dormancy, which requires exposure to winter chilling temperatures, was considered. Three chill models (the 0-7.2°C, Modified Utah, and Dynamic models) were used to investigate changes in chill accumulation at 13 sites across Australia according to localised temperature change related to 1, 2 and 3°C increases in global average temperatures. This methodology avoids reliance on outcomes of future GHG emission pathways, which vary and are likely to change. Regional impacts and rates of decline in chilling differ among the chill models, with the 0-7.2°C model indicating the greatest reduction and the Dynamic model the slowest rate of decline. Elevated and high latitude eastern Australian sites were the least affected while the three more maritime, less elevated Western Australian locations were shown to bear the greatest impact from future warming.

Environmental effects on germination of Carex utriculata and Carex nebrascensis relative to riparian restoration

Treesearch

Kimberly L. Jones; Bruce A. Roundy; Nancy L. Shaw; Jeffrey R. Taylor

2004-01-01

Seasonal riparian seedbed temperatures were measured and germination of Carex utriculata and C. nebrascensis seeds was tested in relation to chilling, perigynia removal, incubation temperature, and light to help guide propagation and direct seeding of these species for riparian restoration. Diurnal temperatures of riparian seedbeds at two sites in Strawberry Valley,...

Gaseous trace impurity analyzer and method

DOEpatents

Edwards, Jr., David; Schneider, William

1980-01-01

Simple apparatus for analyzing trace impurities in a gas, such as helium or hydrogen, comprises means for drawing a measured volume of the gas as sample into a heated zone. A segregable portion of the zone is then chilled to condense trace impurities in the gas in the chilled portion. The gas sample is evacuated from the heated zone including the chilled portion. Finally, the chilled portion is warmed to vaporize the condensed impurities in the order of their boiling points. As the temperature of the chilled portion rises, pressure will develop in the evacuated, heated zone by the vaporization of an impurity. The temperature at which the pressure increase occurs identifies that impurity and the pressure increase attained until the vaporization of the next impurity causes a further pressure increase is a measure of the quantity of the preceding impurity.

Internal porosity of cast titanium removable partial dentures: influence of sprue direction and diameter on porosity in simplified circumferential clasps.

PubMed

Baltag, Ioana; Watanabe, Kouichi; Miyakawa, Osamu

2005-06-01

The behavior of molten titanium in molds of complicated shape is still insufficiently understood; consequently, definite spruing criteria are not yet available for titanium RPD frameworks. This study investigated the influence of sprue design on porosity in pressure-cast titanium circumferential clasps. The patterns of 90 circumferential clasps were sprued with three directions (0, 30 and 60 degrees , as measured between the sprue and the symmetry plane of the clasp assembly) and three sprue diameters (1.5, 2.0 and 2.5mm). CPTi was cast in a one-chamber pressure casting machine. Pore number and size were assessed on radiographs of the castings. Statistical analysis was done by two-way analysis of variance (ANOVA), followed by Fisher's PLSD post hoc test. The porosity in lingual arms increased significantly with increase of sprue diameter and sprue angle, while the porosity in minor connectors had an inversely proportional distribution. Very low porosity, uninfluenced by sprue design, was found in buccal arms. In conclusion, internal porosity in titanium circumferential clasp arms can be minimized through sprue design: the 0 degrees sprue direction produced the least porosity, while for the 30 and 60 degrees directions, 1.5mm diameter sprues produced lower porosity than 2.0 and 2.5mm diameter sprues. In this study, the lowest porosity in titanium circumferential clasp arms was obtained with sprues attached perpendicularly to the minor connectors, regardless of sprue diameter. Conventional sprue directions produced significantly higher porosity in clasp lingual arms, the amount of porosity increasing with sprue diameter.

Research on the influence of moulding-casting technology on the quality of castings

NASA Astrophysics Data System (ADS)

Josan, A.; Pinca Bretotean, C.; Raţiu, S.; Ardelean, E.; Ardelean, M.

2017-05-01

The quality of castings has a particularly role in the Romanian foundries. In this context, quality assurance is the overall objective of the foundries. The paper presents the critical analysis performed on moulding-casting technology of the type Lifting mechanism. This casting is a subset of the lifting and rotating mechanism of the furnace vault. The casting analysed is a medium size, with weight of 114 kg. The current moulding-casting technology involves moulding into three mould-parts leading to the occurrence of defects (decentering of the core, displacement of the lower mould and the middle mould and occurrence of burrs in area separated. Thus, to reduce the percentage of defects registered in industrial practice is necessary to change the moulding-casting technology. This requires the use of two mould-parts, re-dimensioning of the core and the core box and dimensioning of the runner network. The adoption of these changes in industrial practice has direct implications on the cost of casting and foundry costs default.

Effect of flask vibration time on casting integrity, Surface Penetration and Coating Inclusion in lost foam casting of Al-Si Alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karimian, Majid; Idris, M. H.; Ourdjini, A.

2011-01-17

The paper presents the result of an experimental investigation conducted on medium aluminum silicon alloy casting- LM6, using no-vacuum assisted lost foam casting process. The study is directed for establishing the relationship between the flask vibrations times developed for molded sample on the casting integrity, surface penetration and coating inclusion defects of the casting. Four different flask vibration times namely 180, 120, 90 and 60 sec. were investigated. The casting integrity was investigated in terms of fulfilling in all portions and edges. The surface penetration was measured using optical microscope whilst image analyzer was used to quantify the percentage ofmore » coating inclusion in the casting. The results show that vibration time has significant influence on the fulfilling as well as the internal integrity of the lost foam casting. It was found that the lower vibration time produced comparatively sound casing.« less

[Variables effecting casting accuracy of quick heating casting investments].

PubMed

Takahashi, H; Nakamura, H; Iwasaki, N; Morita, N; Habu, N; Nishimura, F

1994-06-01

Recently, several new products of investments for "quick heating" have been put on the Japanese market. The total casting procedure time for this quick heating method involves only one hour; 30-minutes waiting after the start of mixing before placing the mold directly into the 700 degrees C furnace and 30-minutes heating in the furnace. The purpose of this study was to evaluate two variables effecting casting accuracy using these new investments. The effect of thickness of the casting liner inside the casting ring and the effect of waiting time before placing the mold into the 700 degrees C furnace were evaluated. A stainless-steel die with a convergence angle of 8 degrees was employed. Marginal discrepancies of the crown between the wax patterns and castings were measured. The size of the cast crown became larger when the thickness of the ring liner was thick and when the waiting time before placing the mold into the furnace was long. These results suggest that these new investments have the advantage of providing sound castings using short-time casting procedures. However, it is necessary to pay careful attention to the casting conditions for obtaining reproducible castings.

The Influence of Vanadium Microalloying on the Production of Thin Slab Casting and Direct Rolled Steel Strip

NASA Astrophysics Data System (ADS)

Li, Yu; Milbourn, David

Vanadium microalloying is highly effective in high strength strip steels produced by thin slab casting and direct rolled process. Because of the high solubility of V(C,N) in austenite, vanadium is likely to remain in solution during casting, equalisation and rolling. Vanadium microalloyed steels have better hot ductility and are less prone to transverse cracking than niobium containing steels. Despite a coarse as-cast austenite grain size before rolling, significant grain refinement can be achieved in vanadium microalloyed steels by repeated recrystallization during rolling, resulting in a fine uniform ferrite microstructure in final strip. Almost all vanadium present in microalloyed steels is available to precipitate in ferrite as very fine particles, contributing to precipitation strengthening. Vanadium microalloyed steels show less sensitivity to rolling process variables and exhibit excellent combination of strength and toughness.

Method and apparatus for planar drag strip casting

DOEpatents

Powell, John C.; Campbell, Steven L.

1991-01-01

The present invention is directed to an improved process and apparatus for strip casting. The combination of a planar flow casting nozzle positioned back from the top dead center position with an attached nozzle extension, provides an increased level of casting control and quality. The nozzle extension provides a means of containing the molten pool above the rotating substrate to increase the control of molten metal at the edges of the strip and increase the range of coating thicknesses which may be produced. The level of molten metal in the containment means is regulated to be above the level of melt supplying the casting nozzle which produces a condition of planar drag flow with the casting substrate prior to solidification.

Method and apparatus for planar drag strip casting

DOEpatents

Powell, J.C.; Campbell, S.L.

1991-11-12

The present invention is directed to an improved process and apparatus for strip casting. The combination of a planar flow casting nozzle positioned back from the top dead center position with an attached nozzle extension, provides an increased level of casting control and quality. The nozzle extension provides a means of containing the molten pool above the rotating substrate to increase the control of molten metal at the edges of the strip and increase the range of coating thicknesses which may be produced. The level of molten metal in the containment means is regulated to be above the level of melt supplying the casting nozzle which produces a condition of planar drag flow with the casting substrate prior to solidification. 5 figures.

Effects of bacteriophage on the quality and shelf life of Paralichthys olivaceus during chilled storage.

PubMed

Li, Meng; Lin, Hong; Khan, Muhammad Naseem; Wang, Jingxue; Kong, Linghong

2014-06-01

The microbiological spoilage of fishery foods is mainly due to specific spoilage organisms (SSOs), with Shewanella putrefaciens being the SSO of most chilled marine fish. Bacteriophages have shown excellent capability to control micro-organisms. The aim of this study was to determine a specific bacteriophage to prevent spoilage by reducing SSO (S. putrefaciens) levels in the marine fish Paralichthys olivaceus (olive flounder) under chilled storage. Chilled flounder fillets were inoculated with S. putrefaciens and treated with different concentrations of bacteriophage Spp001 ranging from 10(4) to 10(8) plaque-forming units (pfu) mL(-1) . Bacterial growth (including total viable count and SSO) of the bacteriophage-treated groups was significantly inhibited compared with that of the negative control group (P < 0.05). Sensory evaluation and biochemical parameters revealed that the bacteriophage could extend the shelf life of chilled flounder fillets (from <4 to 14 days) with good esthetic quality, even at low temperature (4 °C). Furthermore, bacteriophage concentrations of 10(6) and 10(8) pfu mL(-1) were more effective than the chemical preservative potassium sorbate (5 g L(-1) ). The bacteriophage Spp001 offered effective biocontrol of S. putrefaciens under chilled conditions, retaining the quality characteristics of spiked fish fillets, and thus could be a potential candidate for use in chilled fish fillet biopreservation. © 2013 Society of Chemical Industry.

Effect of methyl salicylate and methyl jasmonate pre-treatment on the volatile profile in tomato fruit subjected to chilling temperature

USDA-ARS?s Scientific Manuscript database

Tomato fruits exposed to chilling temperatures suffer aroma loss prior to visual chilling injury (CI) symptoms. Methyl salicylate (MeSA) and methyl jasmonate (MeJA) treatments were reported to alleviate the development of visual CI, however, it is unknown if the treatments alleviate internal CI in t...

Effect of 1-methylcyclopropene and modified atmosphere packaging on chilling injury, and antioxidative defensive mechanism of sweet pepper

USDA-ARS?s Scientific Manuscript database

Sweet peppers (Capsicum annuum L.) are chilling sensitive vegetable, and develop injury when stored at temperatures less than 7 C. This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP) (650 ppb) and modified atmosphere packaging (MAP) on chilling injuries of sweet pepper...

RNA Expression and Post-Transcriptional Editing Analyses of Cucumber Plastids Reveals Genetic Differences Associated with Chilling Tolerance

USDA-ARS?s Scientific Manuscript database

Tolerance to chilling injury in cucumber (Cucumis sativus L.) is associated with three plastomic single nucleotide polymorphisms (ptSNPs) at bp positions 4,813, 56,561, and 126,349 that are co-inherited. An understanding of the genetic expression of these ptSNPs as a response to chilling is critical...

Aquifer Thermal Energy Storage in the US

NASA Astrophysics Data System (ADS)

Kannberg, L. D.

1985-06-01

DOE has funded investigation of Aquifer Thermal Energy Storage (ATES) since 1975. The scope of the ATES investigation has encompassed numerical modeling, field testing, economic analyses, and evaluation of institutional issues. ATES has received the bulk of the attention because of its widespread potential in the US. US efforts are now concentrated on a high temperature (up to 150C) ATES field test on the St. Paul campus of the University of Minnesota. Four short-term test cycles and the first of two long-term test cycles have been completed at this site. Utilization of chill ATES to meet summer air conditioning demands has been monitored at two operating sites in Tuscaloosa, Alabama. The systems utilize a cooling tower to directly chill groundwater pumped from a water table aquifer for storage in the same aquifer. The first of the two systems has exhibited relatively poor performance. More comprehensive monitoring has recently been undertaken at another site.

Chilling requirements for hatching of a New Zealand isolate of Nematodirus filicollis.

PubMed

Oliver, A-M B; Pomroy, W E; Ganesh, S; Leathwick, D M

2016-08-15

The eggs of some species of the parasitic nematode Nematodirus require a period of chilling before they can hatch; N. filicollis is one such species. This study investigated this requirement for chilling in a New Zealand strain of this species. Eggs of N. filicollis were extracted from lamb's faeces and incubated at 20°C to allow development to the third stage larvae within the egg. These eggs were then placed into tissue culture plates and incubated at: 2.7°C (±0.99), 3.6°C (±0.90), 4.7°C (±0.35), 6.4°C (±0.37), 8.0°C (±1.54) or 9.9°C (±0.14) for up to 224 days. At 14day intervals until day 84, then every 28 days, one plate was removed from each temperature and placed at 13.1°C (±0.44) for 14 days. Eggs were then assessed for hatching. From this data, chill units were calculated by subtracting the culture temperature from a constant threshold of 11°C and multiplying by the number of days for which the sample was cultured; then the Gompertz model fitted. Even though hatching overall was low, a greater proportion of eggs hatched with chill accumulation. Maximum hatching of eggs required 800-1000 chill units. Consequently in the field, more than one season of chilling would be required before hatching. As such a generation time could take more than one year to complete. This is different to the hatching dynamics of N. spathiger, the other main species found in New Zealand sheep, which does not display this requirement for chilling and hatches immediately once the third stage larvae are developed. Copyright © 2016 Elsevier B.V. All rights reserved.

Intercellular Distribution of Glutathione Synthesis in Maize Leaves and Its Response to Short-Term Chilling1

PubMed Central

Gómez, Leonardo D.; Vanacker, Hélène; Buchner, Peter; Noctor, Graham; Foyer, Christine H.

2004-01-01

To investigate the intercellular control of glutathione synthesis and its influence on leaf redox state in response to short-term chilling, genes encoding γ-glutamylcysteine synthetase (γ-ECS) and glutathione synthetase (GSH-S) were cloned from maize (Zea mays) and specific antibodies produced. These tools were used to provide the first information on the intercellular distribution of γ-ECS and GSH-S transcript and protein in maize leaves, in both optimal conditions and chilling stress. A 2-d exposure to low growth temperatures (chill) had no effect on leaf phenotype, whereas return to optimal temperatures (recovery) caused extensive leaf bleaching. The chill did not affect total leaf GSH-S transcripts but strongly induced γ-ECS mRNA, an effect reversed during recovery. The chilling-induced increase in γ-ECS transcripts was not accompanied by enhanced total leaf γ-ECS protein or extractable activity. In situ hybridization and immunolocalization of leaf sections showed that γ-ECS and GSH-S transcripts and proteins were found in both the bundle sheath (BS) and the mesophyll cells under optimal conditions. Chilling increased γ-ECS transcript and protein in the BS but not in the mesophyll cells. Increased BS γ-ECS was correlated with a 2-fold increase in both leaf Cys and γ-glutamylcysteine, but leaf total glutathione significantly increased only in the recovery period, when the reduced glutathione to glutathione disulfide ratio decreased 3-fold. Thus, while there was a specific increase in the potential contribution of the BS cells to glutathione synthesis during chilling, it did not result in enhanced leaf glutathione accumulation at low temperatures. Return to optimal temperatures allowed glutathione to increase, particularly glutathione disulfide, and this was associated with leaf chlorosis. PMID:15047902

Variation in chilling tolerance for photosynthesis and leaf extension growth among genotypes related to the C-4 grass Miscanthus xgiganteus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glowacka, K; Adhikari, S; Peng, JH

The goal of this study was to identify cold-tolerant genotypes within two species of Miscanthus related to the exceptionally chilling-tolerant C-4 biomass crop accession: M. xgiganteus 'Illinois' (Mxg) as well as in other Mxg genotypes. The ratio of leaf elongation at 10 degrees C/5 degrees C to that at 25 degrees C/25 degrees C was used to identify initially the 13 most promising Miscanthus genotypes out of 51 studied. Net leaf CO2 uptake (A(sat)) and the maximum operating efficiency of photosystem II (Phi(PSII)) were measured in warm conditions (25 degrees C/20 degrees C), and then during and following a chillingmore » treatment of 10 degrees C/5 degrees C for 11 d. Accessions of M. sacchariflorus (Msa) showed the smallest decline in leaf elongation on transfer to chilling conditions and did not differ significantly from Mxg, indicating greater chilling tolerance than diploid M. sinensis (Msi). Msa also showed the smallest reductions in A(sat) and Phi(PSII), and greater chilling-tolerant photosynthesis than Msi, and three other forms of Mxg, including new triploid accessions and a hexaploid Mxg 'Illinois'. Tetraploid Msa 'PF30153' collected in Gifu Prefecture in Honshu, Japan did not differ significantly from Mxg 'Illinois' in leaf elongation and photosynthesis at low temperature, but was significantly superior to all other forms of Mxg tested. The results suggested that the exceptional chilling tolerance of Mxg 'Illinois' cannot be explained simply by the hybrid vigour of this intraspecific allotriploid. Selection of chilling-tolerant accessions from both of Mxg's parental species, Msi and Msa, would be advisable for breeding new highly chilling-tolerant Mxg genotypes.« less

Development of low-cost directionally-solidified turbine blades

NASA Technical Reports Server (NTRS)

Hoppin, G. S., III; Fujii, M.; Sink, L. W.

1980-01-01

A low-cost directionally solidified (DS) casting of turbine blades of high stress rupture is discussed. The process uses an exothermically heated mold; a newly designed solid blade was cast for the high-pressure turbine of the TFE731-3 turbofan engine. Ni-based alloys Mar-M 247 and Mar-M 200 + Hf were used. The solid DS blade replaced a conventionally cast IN100 component; a 40% cost saving is expected, with a 2.4% reduction in the takeoff specific fuel consumption. The DS Mar-M 247 blade has been selected for production in the TFE731-3B-100, and advanced version of the TFE731-3.

Dual roles for hepatic lectin receptors in the clearance of chilled platelets.

PubMed

Rumjantseva, Viktoria; Grewal, Prabhjit K; Wandall, Hans H; Josefsson, Emma C; Sørensen, Anne Louise; Larson, Göran; Marth, Jamey D; Hartwig, John H; Hoffmeister, Karin M

2009-11-01

Rapid chilling causes glycoprotein-Ib (GPIb) receptors to cluster on blood platelets. Hepatic macrophage beta(2) integrin binding to beta-N-acetylglucosamine (beta-GlcNAc) residues in the clusters leads to rapid clearance of acutely chilled platelets after transfusion. Although capping the beta-GlcNAc moieties by galactosylation prevents clearance of short-term-cooled platelets, this strategy is ineffective after prolonged refrigeration. We report here that prolonged refrigeration increased the density and concentration of exposed galactose residues on platelets such that hepatocytes, through Ashwell-Morell receptor binding, become increasingly involved in platelet removal. Macrophages rapidly removed a large fraction of transfused platelets independent of their storage conditions. With prolonged platelet chilling, hepatocyte-dependent clearance further diminishes platelet recovery and survival after transfusion. Inhibition of chilled platelet clearance by both beta(2) integrin and Ashwell-Morell receptors may afford a potentially simple method for storing platelets in the cold.

The Fractional Step Method Applied to Simulations of Natural Convective Flows

NASA Technical Reports Server (NTRS)

Westra, Douglas G.; Heinrich, Juan C.; Saxon, Jeff (Technical Monitor)

2002-01-01

This paper describes research done to apply the Fractional Step Method to finite-element simulations of natural convective flows in pure liquids, permeable media, and in a directionally solidified metal alloy casting. The Fractional Step Method has been applied commonly to high Reynold's number flow simulations, but is less common for low Reynold's number flows, such as natural convection in liquids and in permeable media. The Fractional Step Method offers increased speed and reduced memory requirements by allowing non-coupled solution of the pressure and the velocity components. The Fractional Step Method has particular benefits for predicting flows in a directionally solidified alloy, since other methods presently employed are not very efficient. Previously, the most suitable method for predicting flows in a directionally solidified binary alloy was the penalty method. The penalty method requires direct matrix solvers, due to the penalty term. The Fractional Step Method allows iterative solution of the finite element stiffness matrices, thereby allowing more efficient solution of the matrices. The Fractional Step Method also lends itself to parallel processing, since the velocity component stiffness matrices can be built and solved independently of each other. The finite-element simulations of a directionally solidified casting are used to predict macrosegregation in directionally solidified castings. In particular, the finite-element simulations predict the existence of 'channels' within the processing mushy zone and subsequently 'freckles' within the fully processed solid, which are known to result from macrosegregation, or what is often referred to as thermo-solutal convection. These freckles cause material property non-uniformities in directionally solidified castings; therefore many of these castings are scrapped. The phenomenon of natural convection in an alloy under-going directional solidification, or thermo-solutal convection, will be explained. The development of the momentum and continuity equations for natural convection in a fluid, a permeable medium, and in a binary alloy undergoing directional solidification will be presented. Finally, results for natural convection in a pure liquid, natural convection in a medium with a constant permeability, and for directional solidification will be presented.

Apparatus and method for controlling the temperature of the core of a super-conducting transformer

DOEpatents

Golner, Thomas; Pleva, Edward; Mehta, Shirish

2006-10-10

An apparatus for controlling the temperature of a core of a transformer is provided that includes a core, a shield surrounding the core, a cast formed between the core and the shield, and tubing positioned on the shield. The cast directs heat from the core to the shield and cooling fluid is directed through the tubing to cool the shield.

Adaptive significance of the Indian caste system: an ecological perspective.

PubMed

Gadgil, M; Malhotra, K C

1983-01-01

Indian society is an agglomeration of several thousand endogamous groups or castes each with a restricted geographical range and a hereditarily determined mode of subsistence. These reproductively isolated castes may be compared to biological species, and the society thought of as a biological community with each caste having its specific ecological niche. In this paper we examine the ecological-niche relationships of castes which are directly dependent on natural resources. Evidence is presented to show that castes living together in the same region had so organized their pattern of resource use as to avoid excessive intercaste competition for limiting resources. Furthermore, territorial division of the total range of the caste regulated intra-caste competition. Hence, a particular plant or animal resource in a given locality was used almost exclusively by a given lineage within a caste generation after generation. This favoured the cultural evolution of traditions ensuring sustainable use of natural resources. This must have contributed significantly to the stability of Indian caste society over several thousand years. The collapse of the base of natural resources and increasing monetarization of the economy has, however, destroyed the earlier complementarity between the different castes and led to increasing conflicts between them in recent years.

Mold with improved core for metal casting operation

DOEpatents

Gritzner, Verne B.; Hackett, Donald W.

1977-01-01

The present invention is directed to a mold containing an improved core for use in casting hollow, metallic articles. The core is formed of, or covered with, a layer of cellular material which possesses sufficient strength to maintain its structural integrity during casting, but will crush to alleviate the internal stresses that build up if the normal contraction during solidification and cooling is restricted.

Casting technology for manufacturing metal rods from simulated metallic spent fuels

NASA Astrophysics Data System (ADS)

Leeand, Y. S.; Lee, D. B.; Kim, C. K.; Shin, Y. J.; Lee, J. H.

2000-09-01

A uranium metal rod 13.5 mm in diameter and 1,150 mm long was produced from simulated metallic spent fuels with advanced casting equipment using the directional-solidification method. A vacuum casting furnace equipped with a four-zone heater to prevent surface oxidation and the formation of surface shrinkage holes was designed. By controlling the axial temperature gradient of the casting furnace, deformation by the surface shrinkage phenomena was diminished, and a sound rod was manufactured. The cooling behavior of the molten uranium was analyzed using the computer software package MAGMAsoft.

EFFECT OF DRY AIR CHILLING ON WARNER-BRATZLER SHEAR FORCE AND WATER-HOLDING CAPACITY OF BROILER MEAT DEBONED FOUR HOURS POSTMORTEM

USDA-ARS?s Scientific Manuscript database

TECHNICAL ABSTRACT Advantages of air chilling (AC) methods over immersion chilling (IC) methods in quality retention and improvement of deboned chicken breast meat depends on experimental conditions, such as deboning time. The objective of this study was to evaluate the effect of a dry-AC method on ...

Physiological girdling of pine trees via phloem chilling: proof of concept

Treesearch

Kurt Johnsen; Chris Maier; Felipe Sanchez; Peter Anderson; John Butnor; Richard Waring; Sune Linder

2007-01-01

Quantifying below-ground carbon (C) allocation is particularly difficult as methods usually disturb the root– mycorrhizal–soil continuum. We reduced C allocation below ground of loblolly pine trees by: (1) physically girdling trees and (2) physiologically girdling pine trees by chilling the phloem. Chilling reduced cambium temperatures by approximately 18 °C. Both...

Tradeoffs between chilling and forcing in satisfying dormancy requirements for Pacific Northwest tree species

Treesearch

Constance A. Harrington; Peter J. Gould

2015-01-01

Many temperate and boreal tree species have a chilling requirement, that is, they need to experience cold temperatures during fall and winter to burst bud normally in the spring. Results from trials with 11 Pacific Northwest tree species are consistent with the concept that plants can accumulate both chilling and forcing units simultaneously during the dormant season...

Modeling the effects of winter environment on dormancy release of Douglas-fir

Treesearch

Connie Harrington; Peter J. Gould; Brad St. Clair

2010-01-01

Most temperate woody plants have a winter chilling requirement to prevent budburst during midwinter periods of warm weather. The date of spring budburst is dependent on both chilling and forcing; modeling this date is an important part of predicting potential effects of global warming on trees. There is no clear evidence from the literature that the curves of chilling...

Chills in Different Sensory Domains: Frisson Elicited by Acoustical, Visual, Tactile and Gustatory Stimuli

ERIC Educational Resources Information Center

Grewe, Oliver; Katzur, Bjorn; Kopiez, Reinhard; Altenmuller, Eckart

2011-01-01

"Chills" (frisson manifested as goose bumps or shivers) have been used in an increasing number of studies as indicators of emotions in response to music (e.g., Craig, 2005; Guhn, Hamm, & Zentner, 2007; McCrae, 2007; Panksepp, 1995; Sloboda, 1991). In this study we present evidence that chills can be induced through aural, visual, tactile, and…

76 FR 70411 - Fresh and Chilled Atlantic Salmon From Norway: Final Results of Full Third Sunset Review of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-14

... Salmon From Norway: Final Results of Full Third Sunset Review of Countervailing Duty Order AGENCY: Import... fresh and chilled Atlantic salmon from Norway pursuant to section 751(c) of the Tariff Act of 1930, as... on fresh and chilled Atlantic salmon from Norway pursuant to section 751(c) of the Act. See Sunset...

76 FR 70409 - Fresh and Chilled Atlantic Salmon From Norway: Final Results of Full Third Sunset Review of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-14

... Salmon From Norway: Final Results of Full Third Sunset Review of Antidumping Duty Order AGENCY: Import... and chilled Atlantic salmon from Norway pursuant to section 751(c) of the Tariff Act of 1930, as... Department initiated the third sunset review of the AD order on fresh and chilled Atlantic salmon from Norway...

76 FR 45513 - Fresh and Chilled Atlantic Salmon From Norway: Preliminary Results of Full Third Sunset Review of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-29

... Salmon From Norway: Preliminary Results of Full Third Sunset Review of Antidumping Duty Order AGENCY...) order on fresh and chilled Atlantic salmon from Norway pursuant to section 751(c) of the Tariff Act of..., the Department initiated the third sunset review of the AD order on fresh and chilled Atlantic salmon...

76 FR 37786 - Fresh and Chilled Atlantic Salmon From Norway: Preliminary Results of Full Third Sunset Review of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-28

... Salmon From Norway: Preliminary Results of Full Third Sunset Review of Countervailing Duty Order AGENCY... (CVD) order on fresh and chilled Atlantic salmon from Norway pursuant to section 751(c) of the Tariff... the CVD order on fresh and chilled Atlantic salmon from Norway pursuant to section 751(c) of the Act...

The fate of Salmonella Typhimurium and Escherichia coli O157 on hot boned versus conventionally chilled beef.

PubMed

Reid, Rachael; Fanning, Séamus; Whyte, Paul; Kerry, Joe; Bolton, Declan

2017-04-01

This study investigated the fate of Salmonella Typhimurium and Escherichia coli O157 on hot boned versus conventionally chilled beef. Beef samples were individually inoculated with S. Typhimurium ATCC 14028, S. Typhimurium 844, E. coli O157 EDL 933 or E. coli T13. Half the samples were subject to the same time-temperature chilling profile used for conventionally chilling beef carcasses while the other half was subject to hot boned conditions. The surface pH (5.5) and a w (0.95 to 0.97) were stable. S. Typhimurium and E. coli O157 counts, which decreased by up to 1.0 and 1.5log 10 cfucm -2 , respectively, were statistically similar (P>0.05), regardless of the chilling regime applied, with the exception of E. coli O157 EDL 933, where the counts on hot boned beef were significantly (P<0.05) higher. It was concluded that any decrease in pathogenic bacteria during beef chilling may be significantly (P<0.05) less for hot boned beef depending on the bacterial strain. Hot boning may therefore result in an increased risk to the consumer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chilling-induced tomato flavor loss is associated with altered volatile synthesis and transient changes in DNA methylation.

PubMed

Zhang, Bo; Tieman, Denise M; Jiao, Chen; Xu, Yimin; Chen, Kunsong; Fei, Zhangjun; Giovannoni, James J; Klee, Harry J

2016-11-01

Commercial tomatoes are widely perceived by consumers as lacking flavor. A major part of that problem is a postharvest handling system that chills fruit. Low-temperature storage is widely used to slow ripening and reduce decay. However, chilling results in loss of flavor. Flavor-associated volatiles are sensitive to temperatures below 12 °C, and their loss greatly reduces flavor quality. Here, we provide a comprehensive view of the effects of chilling on flavor and volatiles associated with consumer liking. Reduced levels of specific volatiles are associated with significant reductions in transcripts encoding key volatile synthesis enzymes. Although expression of some genes critical to volatile synthesis recovers after a return to 20 °C, some genes do not. RNAs encoding transcription factors essential for ripening, including RIPENING INHIBITOR (RIN), NONRIPENING, and COLORLESS NONRIPENING are reduced in response to chilling and may be responsible for reduced transcript levels in many downstream genes during chilling. Those reductions are accompanied by major changes in the methylation status of promoters, including RIN Methylation changes are transient and may contribute to the fidelity of gene expression required to provide maximal beneficial environmental response with minimal tangential influence on broader fruit developmental biology.

Acute cooling of the feet and the onset of common cold symptoms.

PubMed

Johnson, Claire; Eccles, Ronald

2005-12-01

There is a common folklore that chilling of the body surface causes the development of common cold symptoms, but previous clinical research has failed to demonstrate any effect of cold exposure on susceptibility to infection with common cold viruses. This study will test the hypothesis that acute cooling of the feet causes the onset of common cold symptoms. 180 healthy subjects were randomized to receive either a foot chill or control procedure. All subjects were asked to score common cold symptoms, before and immediately after the procedures, and twice a day for 4/5 days. 13/90 subjects who were chilled reported they were suffering from a cold in the 4/5 days after the procedure compared to 5/90 control subjects (P=0.047). There was no evidence that chilling caused any acute change in symptom scores (P=0.62). Mean total symptom score for days 1-4 following chilling was 5.16 (+/-5.63 s.d. n=87) compared to a score of 2.89 (+/-3.39 s.d. n=88) in the control group (P=0.013). The subjects who reported that they developed a cold (n=18) reported that they suffered from significantly more colds each year (P=0.007) compared to those subjects who did not develop a cold (n=162). Acute chilling of the feet causes the onset of common cold symptoms in around 10% of subjects who are chilled. Further studies are needed to determine the relationship of symptom generation to any respiratory infection.

Influence of chilling and drought on water relations and abscisic acid accumulation in bean

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vernieri, P.; Pardossi, A.; Tognoni, F.

Intact bean seedlings were subjected to either chilling (4{degree}C) or drought stress. Leaf water relations and abscisic acid (ABA) content were monitored throughout a stress-recovery cycle. Chilling at low relative humidity (RH) and drought caused similar water deficits, as indicated by the decline in relative water content and water potentials, but they had different effects on ABA accumulation. There was a rapid increase in ABA levels in the leaves of water-deprived plants while only slight ABA accumulation was observed after 48 h of chilling (4{degree}C). After 24 h cold treatment there were large changes in turgor but no change inmore » ABA content. Plants chilled for 24 h accumulated ABA only when transferred to recovery conditions (20{degree}C, 90-95% RH, in the dark) to an extent that was related to the rate of leaf rehydration. When the chilling treatment was performed in a water-saturated atmosphere, plants did not suffer any water stress and ABA levels did not increase over a period of 48 h. However, when the chilling treatment lasted for a longer period (72 h), a significant increase in ABA levels was found also in the absence of water deficit. Experiments performed with leaf discs incubated in a mannitol solution (osmotic potential {minus}1{center dot}6 MPa) at different temperatures indicated that low temperature markedly inhibits ABA synthesis and that water stress induces increases in ABA content only at non-limiting warm temperatures.« less

Effect of cooling rate upon processing characteristics of pork meat of different glycolysis type during post mortem ageing.

PubMed

Vada, M

1977-10-01

Rapid chilling was applied to porcine longissimus dorsi muscles at 1 h post mortem in order to observe its effect on the quality of canned products prepared from those of different pH(1) values. The muscle from one side of each animal was removed from the carcase 50 minutes post mortem and divided into two longitudinal strips. One was chilled immediately to 13-15°C (1 h post mortem): the other after a further hour (2 h post mortem) acted as control. After the centre temperature had reached 10°C the muscles were stored in a refrigerator at 3-5°C. Compared with the control samples (chilled at 2 h p.m.), rapid chilling from 1 h p.m. caused an improvement in the water-holding capacity and the texture of pork meat, which had higher pH(1) values and was processed at 2, 4 and 48 h p.m. There was minimum brine retention and texture score if samples-both rapidly chilled and control-were processed at 24 h p.m. Although brine retention of PSE pork meat could not be increased even by rapid chilling, the texture of heat treated PSE pork showed an improvement during storage, which was more pronounced after ageing for 48 h, if PSE samples were chilled at 1 h p.m. Copyright © 1977. Published by Elsevier Ltd.

Optimization to Develop Multiple Response Microstructure and Hardness of Ductile Iron Casting by using GRA

NASA Astrophysics Data System (ADS)

Kabnure, Bahubali Bhupal; Shinde, Vasudev Dhondiram; Kolhapure, Rakesh Ramchandra

2018-05-01

Ductile irons are important engineering materials because of its high strength to weight ratio and castability. The ductile iron castings are used widely for automobile applications due to their wide spectrum of property range. Weight reduction is important in automobile to improve its fuel efficiency which can be achieved by thinning down the casting sections without altering its functionality. Generally, automobile castings are having varying section thickness. Varying thickness castings offers different cooling rates while solidification of the casting. The solidification cooling rate decides the final microstructure of the cast components. Cooling rate was found to affect directly the amount of pearlite and ultimately the as cast properties in varying thickness ductile iron castings. In view of this, the automobile impeller casting is selected for study in the present work as it consists of varying section thickness in which small sections are connected to central hub. The casting solidification simulations were performed and analyzed. The solidification cooling rates were analyzed further to correlate the experimental processing parameters. The samples from poured castings were analyzed for microstructure and hardness at different section thickness. Multiple response optimization of microstructure and hardness was carried out by combined Taguchi and Grey Relational Analysis (GRA). Contribution of input variables on the output variables is attained using ANOVA.

Birefringence control of solution-cast film of cellulose triacetate

NASA Astrophysics Data System (ADS)

Kiyama, Ayumi; Nobukawa, Shogo; Yamaguchi, Masayuki

2017-10-01

We controlled the optical anisotropy of a solution-cast film composed of cellulose triacetate (CTA) by adding ferrocene. Owing to the molecular orientation in the film plane of solution-cast films, which results from the normal stress applied during the solvent evaporation process, the average refractive index is usually higher in the plane of the film than in the thickness direction. We found that the addition of ferrocene, which is miscible with CTA, reduced the optical anisotropy by nematic interaction; i.e., ferrocene molecules are forcibly embedded into the film plane accompanying the CTA chains. Because the direction of anisotropic polarizability of ferrocene is perpendicular to the long axis of the molecule, the refractive index in the thickness direction is reduced. Furthermore, the stress-optical coefficient in the glassy state is reduced by the addition of ferrocene.

The perception of 3-D shape from shadows cast onto curved surfaces.

PubMed

Norman, J Farley; Lee, Young-lim; Phillips, Flip; Norman, Hideko F; Jennings, L RaShae; McBride, T Ryan

2009-05-01

In a natural environment, cast shadows abound. Objects cast shadows both upon themselves and upon background surfaces. Previous research on the perception of 3-D shape from cast shadows has only examined the informativeness of shadows cast upon flat background surfaces. In outdoor environments, however, background surfaces often possess significant curvature (large rocks, trees, hills, etc.), and this background curvature distorts the shape of cast shadows. The purpose of this study was to determine the extent to which observers can "discount" the distorting effects of curved background surfaces. In our experiments, observers viewed deforming or static shadows of naturally shaped objects, which were cast upon flat and curved background surfaces. The results showed that the discrimination of 3-D object shape from cast shadows was generally invariant over the distortions produced by hemispherical background surfaces. The observers often had difficulty, however, in identifying the shadows cast onto saddle-shaped background surfaces. The variations in curvature which occur in different directions on saddle-shaped background surfaces cause shadow distortions that lead to difficulties in object recognition and discrimination.

Decision-relevant evaluation of climate models: A case study of chill hours in California

NASA Astrophysics Data System (ADS)

Jagannathan, K. A.; Jones, A. D.; Kerr, A. C.

2017-12-01

The past decade has seen a proliferation of different climate datasets with over 60 climate models currently in use. Comparative evaluation and validation of models can assist practitioners chose the most appropriate models for adaptation planning. However, such assessments are usually conducted for `climate metrics' such as seasonal temperature, while sectoral decisions are often based on `decision-relevant outcome metrics' such as growing degree days or chill hours. Since climate models predict different metrics with varying skill, the goal of this research is to conduct a bottom-up evaluation of model skill for `outcome-based' metrics. Using chill hours (number of hours in winter months where temperature is lesser than 45 deg F) in Fresno, CA as a case, we assess how well different GCMs predict the historical mean and slope of chill hours, and whether and to what extent projections differ based on model selection. We then compare our results with other climate-based evaluations of the region, to identify similarities and differences. For the model skill evaluation, historically observed chill hours were compared with simulations from 27 GCMs (and multiple ensembles). Model skill scores were generated based on a statistical hypothesis test of the comparative assessment. Future projections from RCP 8.5 runs were evaluated, and a simple bias correction was also conducted. Our analysis indicates that model skill in predicting chill hour slope is dependent on its skill in predicting mean chill hours, which results from the non-linear nature of the chill metric. However, there was no clear relationship between the models that performed well for the chill hour metric and those that performed well in other temperature-based evaluations (such winter minimum temperature or diurnal temperature range). Further, contrary to conclusions from other studies, we also found that the multi-model mean or large ensemble mean results may not always be most appropriate for this outcome metric. Our assessment sheds light on key differences between global versus local skill, and broad versus specific skill of climate models, highlighting that decision-relevant model evaluation may be crucial for providing practitioners with the best available climate information for their specific needs.

Impact of dry chilling on the genetic diversity of Escherichia coli on beef carcasses and on the survival of E. coli and E. coli O157.

PubMed

Visvalingam, Jeyachchandran; Liu, Yang; Yang, Xianqin

2017-03-06

The objective of this study was to examine the effect of dry chilling on the genetic diversity of naturally occurring Escherichia coli on beef carcasses, and to examine whether two populations of E. coli recovered from carcasses during chilling and E. coli O157 differed in their response to desiccation. Isolates of E. coli were obtained from beef carcasses during a 67h dry chilling process and were genotyped using multiple-locus variable-number tandem-repeat analysis (MLVA). Ten E. coli genotypes found only at 0h (group A) and found more than once (group B), as well as five strains of E. coli O157 (group C) were inoculated on stainless steel coupons and their survival was examined after exposure to 75 and 100% relative humidity (RH) at 0 or 35°C for 67h. A total of 450 E. coli isolates were obtained, with 254, 49, 49, 51, 23, 20, and 4 from 0, 1, 2, 4, 6, 8 and 24h of chilling, respectively. No E. coli were recovered at 67h. MLVA of the isolates revealed 173 distinct genotypes. Genetic diversity of E. coli isolates, defined as ratio of the number of isolates to the number of genotypes, remained between 2.3 and 1.3 during the 24h of chilling. All strains inoculated on stainless steel coupons and exposed to 75% RH at 35°C were completely inactivated, irrespective of their groups. Inactivation of E. coli of the three groups was not significantly (P>0.05) different by exposure to 75% RH at 0°C. The findings indicate that the genetic diversity of E. coli on beef carcasses was not affected by dry chilling. In addition, inactivation of E. coli genotypes and E. coli O157 by desiccation on stainless steel simulating dry chilling conditions did not differ significantly (P>0.05). Thus, dry chilling may be used as an effective antimicrobial intervention for beef carcasses. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

APPARATUS AND METHOD FOR INJECTION CASTING

DOEpatents

Shuck, A.B.

1960-09-13

S>A single-chamber metal casting apparatus is described wherein molten metal in a vertically movable container can be brought directly into contact with molds. By increasing the gas pressure within the chamber the metal is forced upward into the molds.

Evaluation of food-relevant chemicals in the ToxCast high-throughput screening program

EPA Pesticide Factsheets

Thousands of chemicals are directly added to or come in contact with food, many of which have undergone little to no toxicological evaluation. The landscape of the food-relevant chemical universe was evaluated using cheminformatics, and subsequently the bioactivity of food-relevant chemicals across the publicly available ToxCast highthroughput screening program was assessed. In total, 8659 food-relevant chemicals were compiled including direct food additives, food contact substances, and pesticides. Of these food-relevant chemicals, 4719 had curated structure definition files amenable to defining chemical fingerprints, which were used to cluster chemicals using a selforganizing map approach. Pesticides, and direct food additives clustered apart from one another with food contact substances generally in between, supporting that these categories not only reflect different uses but also distinct chemistries. Subsequently, 1530 food-relevant chemicals were identified in ToxCast comprising 616 direct food additives, 371 food contact substances, and 543 pesticides. Bioactivity across ToxCast was filtered for cytotoxicity to identify selective chemical effects. Initiating analyses from strictly chemical-based methodology or bioactivity/cytotoxicity-driven evaluation presents unbiased approaches for prioritizing chemicals. Although bioactivity in vitro is not necessarily predictive of adverse effects in vivo, these data provide insight into chemical properties and cellu

Biogenic amine concentrations and evolution in "chilled" Canadian pork for the Japanese market.

PubMed

Ngapo, Tania M; Vachon, Lise

2017-10-15

The aim of this study was to evaluate concentrations and evolution of biogenic amines in Canadian pork destined for the Japanese market. At 48h post-mortem, export quality loins were aged at -1.7°C for 13, 28, 43 or 58d (chilled) or 4.0°C for 5d (fresh). Increasing concentrations of putrescine, spermine and spermidine were observed with chilled ageing period and were greater in chilled export (43d at -1.7°C) than domestic market (5d at 4.0°C) pork equivalents. Cadaverine was detected, but was not influenced by ageing conditions, and tyramine was only detected in some samples after 43days at -1.7°C. Individual biogenic amines were not correlated with their precursor amino acids. Biogenic amines in Canadian pork for the chilled export Japanese market were not in sufficiently high concentrations to pose a risk of intoxication. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Comparative transcriptome profiling of chilling stress responsiveness in grafted watermelon seedlings.

PubMed

Xu, Jinhua; Zhang, Man; Liu, Guang; Yang, Xingping; Hou, Xilin

2016-12-01

Rootstock grafting may improve the resistance of watermelon plants to low temperatures. However, information regarding the molecular responses of rootstock grafted plants to chilling stress is limited. To elucidate the molecular mechanisms of chilling tolerance in grafted plants, the transcriptomic responses of grafted watermelon under chilling stress were analyzed using RNA-seq analysis. Sequencing data were used for digital gene expression (DGE) analysis to characterize the transcriptomic responses in grafted watermelon seedlings. A total of 702 differentially-expressed genes (DEGs) were found in rootstock grafted (RG) watermelon relative to self-grafted (SG) watermelon; among these genes, 522 genes were up-regulated and 180 were down-regulated. Additionally, 164 and 953 genes were found to specifically expressed in RG and SG seedlings under chilling stress, respectively. Functional annotations revealed that up-regulated DEGs are involved in protein processing, plant-pathogen interaction and the spliceosome, whereas down-regulated DEGs are associated with photosynthesis. Moreover, 13 DEGs were randomly selected for quantitative real time PCR (qRT-PCR) analysis. The expression profiles of these 13 DEGs were consistent with those detected by the DGE analysis, supporting the reliability of the DGE data. This work provides additional insight into the molecular basis of grafted watermelon responses to chilling stress. Copyright © 2016. Published by Elsevier Masson SAS.

Chilling-induced tomato flavor loss is associated with altered volatile synthesis and transient changes in DNA methylation

PubMed Central

Zhang, Bo; Tieman, Denise M.; Jiao, Chen; Xu, Yimin; Chen, Kunsong; Fei, Zhangjun; Giovannoni, James J.; Klee, Harry J.

2016-01-01

Commercial tomatoes are widely perceived by consumers as lacking flavor. A major part of that problem is a postharvest handling system that chills fruit. Low-temperature storage is widely used to slow ripening and reduce decay. However, chilling results in loss of flavor. Flavor-associated volatiles are sensitive to temperatures below 12 °C, and their loss greatly reduces flavor quality. Here, we provide a comprehensive view of the effects of chilling on flavor and volatiles associated with consumer liking. Reduced levels of specific volatiles are associated with significant reductions in transcripts encoding key volatile synthesis enzymes. Although expression of some genes critical to volatile synthesis recovers after a return to 20 °C, some genes do not. RNAs encoding transcription factors essential for ripening, including RIPENING INHIBITOR (RIN), NONRIPENING, and COLORLESS NONRIPENING are reduced in response to chilling and may be responsible for reduced transcript levels in many downstream genes during chilling. Those reductions are accompanied by major changes in the methylation status of promoters, including RIN. Methylation changes are transient and may contribute to the fidelity of gene expression required to provide maximal beneficial environmental response with minimal tangential influence on broader fruit developmental biology. PMID:27791156

Modeling and Test Data Analysis of a Tank Rapid Chill and Fill System for the Advanced Shuttle Upper Stage (ASUS) Concept

NASA Technical Reports Server (NTRS)

Flachbart, Robin; Hedayat, Ali; Holt, Kimberly A.; Cruit, Wendy (Technical Monitor)

2001-01-01

The Advanced Shuttle Upper Stage (ASUS) concept addresses safety concerns associated .with cryogenic stages by launching empty, and filling on ascent. The ASUS employs a rapid chill and fill concept. A spray bar is used to completely chill the tank before fill, allowing the vent valve to be closed during the fill process. The first tests of this concept, using a flight size (not flight weight) tank. were conducted at Marshall Space Flight Center (MSFC) during the summer of 2000. The objectives of the testing were to: 1) demonstrate that a flight size tank could be filled in roughly 5 minutes to accommodate the shuttle ascent window, and 2) demonstrate a no-vent fill of the tank. A total of 12 tests were conducted. Models of the test facility fill and vent systems, as well as the tank, were constructed. The objective of achieving tank fill in 5 minutes was met during the test series. However, liquid began to accumulate in the tank before it was chilled. Since the tank was not chilled until the end of each test, vent valve closure during fill was not possible. Even though the chill and fill process did not occur as expected, reasonable model correlation with the test data was achieved.

Feasibility of producing cast-refractory metal-fiber superalloy composites

NASA Technical Reports Server (NTRS)

Mcintyre, R. D.

1973-01-01

A study was conducted to evaluate the feasibility of direct casting as a practical method for producing cast superalloy tungsten or columbium alloy fiber composites while retaining a high percentage of fiber strength. Fourteen nickel base, four cobalt, and three iron based matrices were surveyed for their degree of reaction with the metal fibers. Some stress-rupture results were obtained at temperatures of 760, 816, 871, and 1093 C for a few composite systems. The feasibility of producing acceptable composites of some cast nickel, cobalt, and iron matrix alloys with tungsten or columbium alloy fibers was demonstrated.

Mathematical modelling of growth of Listeria  monocytogenes in raw chilled pork.

PubMed

Ye, K; Wang, K; Liu, M; Liu, J; Zhu, L; Zhou, G

2017-04-01

The aim of this study was to analyse the growth kinetics of Listeria monocytogenes in naturally contaminated chilled pork. A cocktail of 26 meat-borne L. monocytogenes was inoculated to raw or sterile chilled pork to observe its growth at 4, 10, 16, 22 and 28°C respectively. The growth data were fitted by the Baranyi model and Ratkowsky square-root model. Results showed that the Baranyi model and Ratkowsky square-root model could describe the growth characteristics of L. monocytogenes at different temperatures reasonably well in raw chilled pork (1·0 ≤ Bf ≤ Af ≤ 1·1). Compared with the growth of L. monocytogenes in sterile chilled pork, the background microflora had no impact on the growth parameters of L. monocytogenes, except for the lag phase at low temperature storage. The microbial predictive models developed in this study can be used to predict the growth of L. monocytogenes during natural spoilage, and construct quantitative risk assessments in chilled pork. This study simulated the actual growth of Listeria monocytogenes in chilled pork to the maximum extent, and described its growth characteristics of L. monocytogenes during natural spoilage. This study showed that the background microflora had no impact on the growth parameters of L. monocytogenes, except for the lag phase at low temperature storage. The models developed in this study can be used to predict the growth of L. monocytogenes during refrigerated storage. © 2017 The Society for Applied Microbiology.

Suppression Subtractive Hybridization Analysis of Genes Regulated by Application of Exogenous Abscisic Acid in Pepper Plant (Capsicum annuum L.) Leaves under Chilling Stress.

PubMed

Guo, Wei-Li; Chen, Ru-Gang; Gong, Zhen-Hui; Yin, Yan-Xu; Li, Da-Wei

2013-01-01

Low temperature is one of the major factors limiting pepper (Capsicum annuum L.) production during winter and early spring in non-tropical regions. Application of exogenous abscisic acid (ABA) effectively alleviates the symptoms of chilling injury, such as wilting and formation of necrotic lesions on pepper leaves; however, the underlying molecular mechanism is not understood. The aim of this study was to identify genes that are differentially up- or downregulated in ABA-pretreated hot pepper seedlings incubated at 6°C for 48 h, using a suppression subtractive hybridization (SSH) method. A total of 235 high-quality ESTs were isolated, clustered and assembled into a collection of 73 unigenes including 18 contigs and 55 singletons. A total of 37 unigenes (50.68%) showed similarities to genes with known functions in the non-redundant database; the other 36 unigenes (49.32%) showed low similarities or unknown functions. Gene ontology analysis revealed that the 37 unigenes could be classified into nine functional categories. The expression profiles of 18 selected genes were analyzed using quantitative RT-PCR; the expression levels of 10 of these genes were at least two-fold higher in the ABA-pretreated seedlings under chilling stress than water-pretreated (control) plants under chilling stress. In contrast, the other eight genes were downregulated in ABA-pretreated seedlings under chilling stress, with expression levels that were one-third or less of the levels observed in control seedlings under chilling stress. These results suggest that ABA can positively and negatively regulate genes in pepper plants under chilling stress.

Differentiated dynamics of bud dormancy and growth in temperate fruit trees relating to bud phenology adaptation, the case of apple and almond trees.

PubMed

El Yaacoubi, Adnane; Malagi, Gustavo; Oukabli, Ahmed; Citadin, Idemir; Hafidi, Majida; Bonhomme, Marc; Legave, Jean-Michel

2016-11-01

Few studies have focused on the characterization of bud dormancy and growth dynamics for temperate fruit species in temperate and mild cropping areas, although this is an appropriate framework to anticipate phenology adaptation facing future warming contexts which would potentially combine chill declines and heat increases. To examine this issue, two experimental approaches and field observations were used for high- and low-chill apple cultivars in temperate climate of southern France and in mild climates of northern Morocco and southern Brazil. Low-chill almond cultivars offered an additional relevant plant material for comparison with apple in northern Morocco. Divergent patterns of dormancy and growth dynamics were clearly found in apple tree between southern France and southern Brazil. Divergences were less pronounced between France and Morocco. A global view outlined main differences in the dormancy chronology and intensity, the transition between endordormancy and ecodormancy and the duration of ecodormancy. A key role of bud rehydration in the transition period was shown. High-chill cultivars would be submitted in mild conditions to heterogeneous rehydration capacities linked to insufficient chill fulfillment and excessive forcing linked to high temperatures. This would favor bud competitions and consequently excessive flowering durations and weak flowering. Low chilling requirements in apple and almond would conversely confer biological capacities to tolerate superficial dormancy and abrupt transition from endordormancy to ecodormancy without important heterogeneous rehydration states within buds. It may also assume that low-chill cultivars can also tolerate high temperatures during ecodormancy as well as extended flowering durations.

Differentiated dynamics of bud dormancy and growth in temperate fruit trees relating to bud phenology adaptation, the case of apple and almond trees

NASA Astrophysics Data System (ADS)

El Yaacoubi, Adnane; Malagi, Gustavo; Oukabli, Ahmed; Citadin, Idemir; Hafidi, Majida; Bonhomme, Marc; Legave, Jean-Michel

2016-11-01

Few studies have focused on the characterization of bud dormancy and growth dynamics for temperate fruit species in temperate and mild cropping areas, although this is an appropriate framework to anticipate phenology adaptation facing future warming contexts which would potentially combine chill declines and heat increases. To examine this issue, two experimental approaches and field observations were used for high- and low-chill apple cultivars in temperate climate of southern France and in mild climates of northern Morocco and southern Brazil. Low-chill almond cultivars offered an additional relevant plant material for comparison with apple in northern Morocco. Divergent patterns of dormancy and growth dynamics were clearly found in apple tree between southern France and southern Brazil. Divergences were less pronounced between France and Morocco. A global view outlined main differences in the dormancy chronology and intensity, the transition between endordormancy and ecodormancy and the duration of ecodormancy. A key role of bud rehydration in the transition period was shown. High-chill cultivars would be submitted in mild conditions to heterogeneous rehydration capacities linked to insufficient chill fulfillment and excessive forcing linked to high temperatures. This would favor bud competitions and consequently excessive flowering durations and weak flowering. Low chilling requirements in apple and almond would conversely confer biological capacities to tolerate superficial dormancy and abrupt transition from endordormancy to ecodormancy without important heterogeneous rehydration states within buds. It may also assume that low-chill cultivars can also tolerate high temperatures during ecodormancy as well as extended flowering durations.

Effects of chilling and ABA on (/sup 3/H)gibberellin A/sub 4/ metabolism in somatic embryos of grape (Vitis vinifera L. x V. rupestris Scheele)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pearce, D.; Pharis, R.P.; Rajasekaran, K.

1987-06-01

Previous work has indicated that changes in gibberellin (GA) metabolism may be involved in chilling-induced release from dormancy in somatic embryos of grape (Vitis vinifera L. x V. rupestris Scheele). The authors have chilled somatic embryos of grape for 2, 4, or 8 weeks, then incubated them with (/sup 3/H)GA/sub 4/ (of high specific activity, 4.81 x 10/sup 19/ becquerel per millimole) for 48 hours at 26/sup 0/C. Chilling had little effect on the total amount of free (/sup 3/H)GA-like metabolites formed during incubation at 26/sup 0/C, but did change the relative proportions of individual metabolites. The amount of highlymore » water-soluble (/sup 3/H) metabolites formed at 26/sup 0/C decreased in embryos chilled for 4 or 8 weeks. The concentration of endogeneous GA precursors (e.g., GA/sub 12/ aldehyde-, kaurene, and kaurenoic acid-like substances) increased in embryos chilled for 4 or 8 weeks. Treatment with abscisic acid (ABA) (known to inhibit germination in grape embryos) concurrent with (/sup 3/H)GA/sub 4/ treatment at 26/sup 0/C, reduced the uptake of (/sup 3/H) GA/sub 4/ but had little effect on the qualitative spectrum of metabolites. However, in the embryos chilled for 8 weeks and then treated with ABA for 48 hours at 26/sup 0/C, there was a higher concentration of GA precursors than in untreated control embryos. Chilled embryos thus have an enhanced potential for an increase in free GAs through synthesis from increased amounts of GA precursors, or through a reduced ability to form highly water-soluble GA metabolites (i.e., GA conjugates or polyhydroxylated free GAs).« less

Effect of different concentrations of soybean lecithin and virgin coconut oil in Tris-based extender on the quality of chilled and frozen-thawed bull semen

PubMed Central

Tarig, A. A.; Wahid, H.; Rosnina, Y.; Yimer, N.; Goh, Y. M.; Baiee, F. H.; Khumran, A. M.; Salman, H.; Assi, M. A.; Ebrahimi, M.

2017-01-01

Aim: The objective of this study was to evaluate the effects of different concentrations of soybean lecithin (SL) and virgin coconut oil (VCO) in Tris-based extender on chilled and frozen-thawed bull semen quality parameters. Materials and Methods: A total of 24 ejaculates were collected from four bulls via an electroejaculator. Semen samples were diluted with 2% VCO in Tris-based extender which consists of various concentrations of SL (1, 1.25, 1.5, and 1.75%). A 20% egg yolk in Tris used as a positive control (C+). The diluted semen samples were divided into two fractions; one for chilling which were stored at 4°C for 24, 72, and 144 h before evaluated for semen quality parameters. The second fraction used for freezing was chilled for 3 h at 4°C, packed into 0.25 mL straws and then cryopreserved in liquid nitrogen. The samples were then evaluated after 7 and 14 days. Chilled and frozen semen samples were thawed at 37°C and assessed for general motility using computer-assisted semen analysis, viability, acrosome integrity and morphology (eosin-nigrosin stain), membrane integrity, and lipid peroxidation using thiobarbituric acid reaction test. Results: The results showed that all the quality parameters assessed were significantly (p<0.05) improved at 1.5% SL concentration in chilled semen. Treatment groups of 1, 1.25, 1.5, and 1.75% SL were higher in quality parameters than the control group (C+) in chilled semen. However, all the quality parameters in frozen-thawed semen were significantly higher in the C+ than the treated groups. Conclusion: In conclusion, supplementation of 1.5% SL in 2% VCO Tris-based extender enhanced the chilled bull semen. However, there was no marked improvement in the frozen-thawed quality parameters after treatment. PMID:28717321

Effect of different concentrations of soybean lecithin and virgin coconut oil in Tris-based extender on the quality of chilled and frozen-thawed bull semen.

PubMed

Tarig, A A; Wahid, H; Rosnina, Y; Yimer, N; Goh, Y M; Baiee, F H; Khumran, A M; Salman, H; Assi, M A; Ebrahimi, M

2017-06-01

The objective of this study was to evaluate the effects of different concentrations of soybean lecithin (SL) and virgin coconut oil (VCO) in Tris-based extender on chilled and frozen-thawed bull semen quality parameters. A total of 24 ejaculates were collected from four bulls via an electroejaculator. Semen samples were diluted with 2% VCO in Tris-based extender which consists of various concentrations of SL (1, 1.25, 1.5, and 1.75%). A 20% egg yolk in Tris used as a positive control (C+). The diluted semen samples were divided into two fractions; one for chilling which were stored at 4°C for 24, 72, and 144 h before evaluated for semen quality parameters. The second fraction used for freezing was chilled for 3 h at 4°C, packed into 0.25 mL straws and then cryopreserved in liquid nitrogen. The samples were then evaluated after 7 and 14 days. Chilled and frozen semen samples were thawed at 37°C and assessed for general motility using computer-assisted semen analysis, viability, acrosome integrity and morphology (eosin-nigrosin stain), membrane integrity, and lipid peroxidation using thiobarbituric acid reaction test. The results showed that all the quality parameters assessed were significantly (p<0.05) improved at 1.5% SL concentration in chilled semen. Treatment groups of 1, 1.25, 1.5, and 1.75% SL were higher in quality parameters than the control group (C+) in chilled semen. However, all the quality parameters in frozen-thawed semen were significantly higher in the C+ than the treated groups. In conclusion, supplementation of 1.5% SL in 2% VCO Tris-based extender enhanced the chilled bull semen. However, there was no marked improvement in the frozen-thawed quality parameters after treatment.

Internal development of vegetative buds of Norway spruce trees in relation to accumulated chilling and forcing temperatures.

PubMed

Viherä-Aarnio, Anneli; Sutinen, Sirkka; Partanen, Jouni; Häkkinen, Risto

2014-05-01

The timing of budburst of temperate trees is known to be controlled by complicated interactions of temperature and photoperiod. To improve the phenological models of budburst, better knowledge of the internal bud development preceding budburst in relation to environmental cues is needed. We studied the effect of accumulated chilling and forcing temperatures on the internal development of vegetative buds preceding budburst in Norway spruce [Picea abies (L.) Karst.]. Branches from 17-year-old trees of southern Finnish origin were transferred eight times at 1- to 2-week intervals from October to December 2007 from the field at Punkaharju (61°48'N, 29°20'E) to the greenhouse with forcing conditions (day length 12 h, +20 °C). After seven different durations of forcing, the developmental phase and primordial shoot growth of the buds were analysed at the stereomicroscopic level. Air temperature was recorded hourly throughout the study period. The accumulated chilling unit sum had a significant effect on the temperature sum that was required to attain a certain developmental phase; a higher amount of chilling required a lower amount of forcing. The variation in the rate of development of different buds within each sample branch in relation to the chilling unit and forcing temperature sum was low. Regarding primordial shoot growth, there was also an inverse relation between accumulated chilling and forcing, i.e., a higher accumulated chilling unit sum before forcing required a lower temperature sum to initiate primordial shoot growth and resulted in a stronger effect of accumulated forcing. A second-order regression model with an interaction of chilling and forcing explained the variation of primordial shoot growth with high precision (R(2) = 0.88). However, further studies are required to determine the final parameter values to be used in phenological modelling. © The Author 2014. Published by Oxford University Press. All rights reserved.

Improvement of turkey breast meat quality and cooked gel functionality using hot-boning, quarter sectioning, crust-freeze-air-chilling and cold-batter-mincing technologies.

PubMed

Lee, H C; Erasmus, M A; Swanson, J C; Hong, H G; Kang, I

2016-01-01

The effect of rapid carcass chilling on breast meat quality was evaluated using commercial (COMM) and random-bred (RB) turkeys. Immediately after slaughter, 48 turkeys from COMM or RB line were randomly subjected to one of four chilling methods: 1) water-immersion chilling (WIC) of the carcasses at 0°C ice slurry, 2) WIC after temperature abuse (TA) of the carcasses at 40°C for 30 min (TA-WIC), 3) hot-boning, quarter sectioning, and crust-freeze-air-chilling (HB-(1)/4CFAC) of breast fillets at -12°C, and 4) HB-(1)/4CFAC of fillets after TA of carcasses (TA-HB-(1)/4CFAC). The TA increased carcass and fillet temperatures by ∼1.3 and ∼4.1°C, respectively, regardless of turkey line, whereas HB-(1)/4CFAC of fillets required 28 and 33% of carcass chilling time for COMM and RB, respectively. During chilling, COMM breast pH rapidly reduced from 6.04 to 5.82, resulting in a significantly lower pH than RB after chilling (P < 0.05), whereas COMM R-value sharply increased from 1.17 to 1.43, causing no difference from RB (P > 0.05). Significantly higher L* value and cooking yield (P < 0.05) were seen in the samples of TA and WIC than those of no TA and HB-(1)/4CFAC, respectively, with no difference observed between COMM and RB fillets (P > 0.05). Higher values of hardness, gumminess, and chewiness were found for RB, no TA, and HB-(1)/4CFAC gels than COMM, TA, and WIC, respectively. These results generally indicated that protein quality and textural properties of turkey fillets were improved, regardless of strains or temperature abuse, using HB-(1)/4CFAC technology. © 2015 Poultry Science Association Inc.

A Simple Algorithm for Predicting Bacteremia Using Food Consumption and Shaking Chills: A Prospective Observational Study.

PubMed

Komatsu, Takayuki; Takahashi, Erika; Mishima, Kentaro; Toyoda, Takeo; Saitoh, Fumihiro; Yasuda, Akari; Matsuoka, Joe; Sugita, Manabu; Branch, Joel; Aoki, Makoto; Tierney, Lawrence; Inoue, Kenji

2017-07-01

Predicting the presence of true bacteremia based on clinical examination is unreliable. We aimed to construct a simple algorithm for predicting true bacteremia by using food consumption and shaking chills. A prospective multicenter observational study. Three hospital centers in a large Japanese city. In total, 1,943 hospitalized patients aged 14 to 96 years who underwent blood culture acquisitions between April 2013 and August 2014 were enrolled. Patients with anorexia-inducing conditions were excluded. We assessed the patients' oral food intake based on the meal immediately prior to the blood culture with definition as "normal food consumption" when >80% of a meal was consumed and "poor food consumption" when <80% was consumed. We also concurrently evaluated for a history of shaking chills. We calculated the statistical characteristics of food consumption and shaking chills for the presence of true bacteremia, and subsequently built the algorithm by using recursive partitioning analysis. Among 1,943 patients, 223 cases were true bacteremia. Among patients with normal food consumption, without shaking chills, the incidence of true bacteremia was 2.4% (13/552). Among patients with poor food consumption and shaking chills, the incidence of true bacteremia was 47.7% (51/107). The presence of poor food consumption had a sensitivity of 93.7% (95% confidence interval [CI], 89.4%-97.9%) for true bacteremia, and the absence of poor food consumption (ie, normal food consumption) had a negative likelihood ratio (LR) of 0.18 (95% CI, 0.17-0.19) for excluding true bacteremia, respectively. Conversely, the presence of the shaking chills had a specificity of 95.1% (95% CI, 90.7%-99.4%) and a positive LR of 4.78 (95% CI, 4.56-5.00) for true bacteremia. A 2-item screening checklist for food consumption and shaking chills had excellent statistical properties as a brief screening instrument for predicting true bacteremia. © 2017 Society of Hospital Medicine

Rested and stressed farmed Atlantic cod (Gadus morhua) chilled in ice or slurry and effects on quality.

PubMed

Digre, Hanne; Erikson, Ulf; Aursand, Ida G; Gallart-Jornet, Lorena; Misimi, Ekrem; Rustad, Turid

2011-01-01

The main objectives of this study were to investigate (1) whether rested harvest of farmed cod was better maintained by chilling with slurry rather than by traditional ice storage, (2) whether chilling with slurry would be a feasible chilling method to assure low core temperatures (≤0 °C) at packing of gutted fish, and (3) the effects of superchilling compared with traditional ice on selected quality parameters of cod during storage. In the experiment, seawater slurry at -2.0 ± 0.3 °C was used. Anesthetized (AQUI-S™), percussion stunned, and stressed cod chilled in slurry were compared. Cod stored on ice were used as reference group. The fish were evaluated at the day of slaughter, and after 7 and 14 d of storage according to handling stress (initial muscle pH, muscle twitches, rigor mortis), core temperatures, quality index method, microbial counts, weight changes, salt and water content, water distribution, pH, adenosine triphosphate-degradation products, K-value, water-holding capacity, fillet color, and texture. Chilling cod in slurry was more rapid than chilling in ice. Prechilling (1 d) of cod in slurry before subsequent ice storage resulted in lower quality 7 d postmortem compared with both ice and continuous slurry storage. The potential advantages of superchilling became more prominent after 14 d with lower microbiological activity, better maintenance of freshness (lower total quality index scores and lower K-values) compared with fish stored on ice. A drawback with slurry-stored fish was that cloudy eyes developed earlier, in addition to weight gain and salt uptake compared to ice-stored fish. Practical Application: Chilling is an essential operation in any fish-processing plant. This manuscript addresses different applications of slurry ice in the processing and storage of Atlantic cod. Cod quality was assessed after 7 and 14 d of iced and superchilled storage.

Impact of cooking, cooling, and subsequent refrigeration on the growth or survival of Clostridium perfringens in cooked meat and poultry products.

PubMed

Kalinowski, Robin M; Tompkin, R Bruce; Bodnaruk, Peter W; Pruett, W Payton

2003-07-01

In January 1999, the Food Safety and Inspection Service (FSIS) finalized performance standards for the cooking and chilling of meat and poultry products in federally inspected establishments. More restrictive chilling (stabilization) requirements were adopted despite the lack of strong evidence of a public health risk posed by industry practices employing the original May 1988 guidelines (U.S. Department of Agriculture FSIS Directive 7110.3). Baseline data led the FSIS to estimate a "worst case" of 10(4) Clostridium perfringens cells per g in raw meat products. The rationale for the FSIS performance standards was based on this estimate and the assumption that the numbers detected in the baseline study were spores that could survive cooking. The assumptions underlying the regulation stimulated work in our laboratory to help address why there have been so few documented outbreaks of C. perfringens illness associated with the consumption of commercially processed cooked meat and poultry products. Our research took into account the numbers of C. perfringens spores in both raw and cooked products. One hundred ninety-seven raw comminuted meat samples were cooked to 73.9 degrees C and analyzed for C. perfringens levels. All but two samples had undetectable levels (<3 spores per g). Two ground pork samples contained 3.3 and 66 spores per g. Research was also conducted to determine the effect of chilling on the outgrowth of C. perfringens spores in cured and uncured turkey. Raw meat blends inoculated with C. perfringens spores, cooked to 73.9 degrees C, and chilled according to current guidelines or under abuse conditions yielded increases of 2.25 and 2.44 log10 CFU/g for uncured turkey chilled for 6 h and an increase of 3.07 log10 CFU/g for cured turkey chilled for 24 h. No growth occurred in cured turkey during a 6-h cooling period. Furthermore, the fate of C. perfringens in cooked cured and uncured turkey held at refrigeration temperatures was investigated. C. perfringens levels decreased by 2.52, 2.54, and 2.75 log10 CFU/g in cured turkey held at 0.6, 4.4, and 10 degrees C, respectively, for 7 days. Finally, 48 production lots of ready-to-eat meat products that had deviated from FSIS guidelines were analyzed for C. perfringens levels. To date, 456 samples have been tested, and all but 25 (ranging from 100 to 710 CFU/g) of the samples contained C. perfringens at levels of <100 CFU/g. These results further support historical food safety data that suggest a very low public health risk associated with C. perfringens in commercially processed ready-to-eat meat and poultry products.

Method for fabricating laminated uranium composites

DOEpatents

Chapman, L.R.

1983-08-03

The present invention is directed to a process for fabricating laminated composites of uranium or uranium alloys and at least one other metal or alloy. The laminated composites are fabricated by forming a casting of the molten uranium with the other metal or alloy which is selectively positioned in the casting and then hot-rolling the casting into a laminated plate in or around which the casting components are metallurgically bonded to one another to form the composite. The process of the present invention provides strong metallurgical bonds between the laminate components primarily since the bond disrupting surface oxides on the uranium or uranium alloy float to the surface of the casting to effectively remove the oxides from the bonding surfaces of the components.

Marginal Accuracy of Castings Fabricated with Ringless Casting Investment System and Metal Ring Casting Investment System: A Comparative Study.

PubMed

Kalavathi, M; Sachin, Bhuvana; Prasanna, B G; Shreeharsha, T V; Praveen, B; Ragher, Mallikarjuna

2016-02-01

The thermal expansion of the investment can be restricted by the metal casting ring because the thermal expansion of the ring is less than that of the investment. The ringless casting procedure is in use in clinical dentistry, though there is little scientific data to support its use in fixed partial dentures. In this study, marginal discrepancy of castings produced with the ringless casting technique and the conventional technique using the metal rings were compared. A total of 30 wax patterns were fabricated directly on a metal die. Optical stereomicroscope was used to measure the marginal discrepancy between the metal die and wax patterns. A total of 15 castings were invested using Bellavest T phosphate-bonded investment with the ringless technique and 15 were invested with the same investment with a metal ring; 30 castings were produced using a nickel-chromium ceramo-metal alloy. The internal surface of the castings was not modified and seated with finger pressure. The vertical marginal discrepancy was measured using an optical stereomicroscope at a magnification of 100x. The data obtained were statistically analyzed using students t-test (paired t-test and unpaired t-test). The castings of the ringless technique provided less vertical marginal discrepancy (240.56 ± 45.81 μ) than the castings produced with the conventional metal ring technique (281.98± 53.05 μ). The difference was statistically significant. The ringless casting technique had produced better marginal accuracy compared with conventional casting technique. Ringless casting system can be used routinely for clinical purpose.

Microstructure, Texture, and Mechanical Behavior of As-cast Ni-Fe-W Matrix Alloy

NASA Astrophysics Data System (ADS)

Rao, A. Sambasiva; Manda, Premkumar; Mohan, M. K.; Nandy, T. K.; Singh, A. K.

2018-04-01

This article describes the tensile properties, flow, and work-hardening behavior of an experimental alloy 53Ni-29Fe-18W in as-cast condition. The microstructure of the alloy 53Ni-29Fe-18W displays single phase (fcc) in as-cast condition along with typical dendritic features. The bulk texture of the as-cast alloy reveals the triclinic sample symmetry and characteristic nature of coarse-grained materials. The alloy exhibits maximum strength ( σ YS and σ UTS) values along the transverse direction. The elongation values are maximum and minimum along the transverse and longitudinal directions, respectively. Tensile fracture surfaces of both the longitudinal and transverse samples display complete ductile fracture features. Two types of slip lines, namely, planar and intersecting, are observed in deformed specimens and the density of slip lines increases with increasing the amount of deformation. The alloy displays moderate in-plane anisotropy ( A IP) and reasonably low anisotropic index ( δ) values, respectively. The instantaneous or work-hardening rate curves portray three typical stages (I through III) along both the longitudinal and transverse directions. The alloy exhibits dislocation-controlled strain hardening during tensile testing, and slip is the predominant deformation mechanism.

Laser-based trace gas detection of ethane as a result of photo-oxidative damage in chilled cucumber leaves (invited)

NASA Astrophysics Data System (ADS)

Santosa, I. E.; Laarhoven, L. J. J.; Harbinson, J.; Driscoll, S.; Harren, F. J. M.

2003-01-01

At low temperatures, high light intensity induces strong photooxidative lipid peroxidation in chilling sensitive cucumber leaves. A sensitive laser-based photoacoustic detector was employed to monitor on-line the evolution of ethane, one of the end products of lipid peroxidation. The Δv=2 CO laser operated in the 2.62-4.06 μm infrared wavelength region with a maximum intracavity power of 11 W. In combination with an intracavity placed photoacoustic cell the laser was able to detect ethane down to 0.5 part per billion. Cucumber leaf disks chilled in the light produce ethane; the rate of ethane production depends on the applied temperature, light intensity, and period of chilling.

Energy conservation for pasteurizer apparatus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huling, J.K.

In the pasteurizing of beverages in closed containers, the containers arrive generally in a chilled state and are progressively raised in temperature approaching the pasteurizing temperature and, after being pasteurized for an appropriate time, are progressively cooled down. Apparatus of this type is provided with a source of chilled water which is available for use when skips occur in the supply of the containers, the chilled water being accumulated from the incoming containers and from common outside sources. The accumulated water in its chilled state saves substantial amounts of energy by eliminating mechanical or other means to produce the chillmore » effect, and such source of water is constantly available under control which senses the presence of a skip in the supply of containers.« less

The Synergistic Priming Effect of Exogenous Salicylic Acid and H2O2 on Chilling Tolerance Enhancement during Maize (Zea mays L.) Seed Germination

PubMed Central

Li, Zhan; Xu, Jungui; Gao, Yue; Wang, Chun; Guo, Genyuan; Luo, Ying; Huang, Yutao; Hu, Weimin; Sheteiwy, Mohamed S.; Guan, Yajing; Hu, Jin

2017-01-01

Chilling stress is an important constraint for maize seedling establishment in the field. To examine the role of salicylic acid (SA) and hydrogen peroxide (H2O2) in response to chilling stress, we investigated the effects of seed priming with SA, H2O2, and SA+H2O2 combination on maize resistance under chilling stress (13°C). Priming with SA, H2O2, and especially SA+H2O2 shortened seed germination time and enhanced seed vigor and seedling growth as compared with hydropriming and non-priming treatments under low temperature. Meanwhile, SA+H2O2 priming notably increased the endogenous H2O2 and SA content, antioxidant enzymes activities and their corresponding genes ZmPAL, ZmSOD4, ZmAPX2, ZmCAT2, and ZmGR expression levels. The α-amylase activity was enhanced to mobilize starch to supply metabolites such as soluble sugar and energy for seed germination under chilling stress. In addition, the SA+H2O2 combination positively up-regulated expressions of gibberellic acid (GA) biosynthesis genes ZmGA20ox1 and ZmGA3ox2, and down-regulated GA catabolism gene ZmGA2ox1 expression; while it promoted GA signaling transduction genes expressions of ZmGID1 and ZmGID2 and decreased the level of seed germination inhibitor gene ZmRGL2. The abscisic acid (ABA) catabolism gene ZmCYP707A2 and the expressions of ZmCPK11 and ZmSnRK2.1 encoding response receptors in ABA signaling pathway were all up-regulated. These results strongly suggested that priming with SA and H2O2 synergistically promoted hormones metabolism and signal transduction, and enhanced energy supply and antioxidant enzymes activities under chilling stress, which were closely relevant with chilling injury alleviation and chilling-tolerance improvement in maize seed. Highlights:Seed germination and seedling growth were significantly improved under chilling stress by priming with SA+H2O2 combination, which was closely relevant with the change of reactive oxygen species, metabolites and energy supply, hormones metabolism and regulation. PMID:28725229

Electrolyte leakage and lipid degradation account for cold sensitivity in leaves of Coffea sp. plants.

PubMed

Campos, Paula Scotti; Quartin, Virgínia; Ramalho, José Cochicho; Nunes, Maria Antonieta

2003-03-01

Five Coffea genotypes differing in their sensitivity to low positive temperatures were compared with regard to the effects of chilling on membrane integrity, as well as their ability to recover from cold-induced injury upon re-warming. Membrane damage was evaluated through electrolyte leakage, changes in membrane lipid composition and malondialdehyde (MDA) production in control conditions (25/20 degrees C, day/night), after a gradual temperature decrease period to 15/10 degrees C, after chilling treatment (3 nights at 4 degrees C) and upon re-warming to 25/20 degrees C during 6 days (recovery). C. dewevrei showed the highest electrolyte leakage at 15/10 degrees C and after chilling. This was due mainly to lipid degradation observed at 15/10 degrees C, reflecting strong membrane damage. Furthermore, MDA production after chilling conditions indicated the occurrence of lipid peroxidation. A higher susceptibility of C. dewevrei to cold also was inferred from the complete absence of recovery as regards permeability, contrary to what was observed in the remaining plants. Apoatã and Piatã presented significant leakage values after chilling. However, such effects were reversible under recovery conditions. Exposure to cold (15/10 degrees C and 3 x 15/4 degrees C) did not significantly affect membrane permeability in Catuaí and Icatú. Furthermore, no significant MDA production was observed even after chilling treatments in Apoatã, Piatã, Catuaí and Icatú, suggesting that the four genotypes had the ability to maintain membrane integrity and/or repair membrane damage caused by low temperatures. Apoatã, Piatã and, to a lower extent, Catuaí, were able to cope with gradual temperature decrease through an enhanced lipid biosynthesis. After acclimation, Piatã and Catuaí showed a lowering of digalactosyldiacylglycerol to monogalactosyldiacylglycerol ratio (MGDG/DGDG) as a result of enhanced DGDG synthesis, which represents an increase in membrane stability. The same was observed in Apoatã after chilling, in spite of phospholipids decrease. The studied parameters clearly indicated that chilling induced irreversible membrane damage in C. dewevrei. We also concluded that increased lipid synthesis, lower MGDG/DGDG ratio, and changes in membrane unsaturation occurring during acclimation to low temperatures may be critical factors in maintenance of cellular integrity under chilling.

Effects of Chilling and Partial Freezing on Rigor Mortis Changes of Bighead Carp (Aristichthys nobilis) Fillets: Cathepsin Activity, Protein Degradation and Microstructure of Myofibrils.

PubMed

Lu, Han; Liu, Xiaochang; Zhang, Yuemei; Wang, Hang; Luo, Yongkang

2015-12-01

To investigate the effects of chilling and partial freezing on rigor mortis changes in bighead carp (Aristichthys nobilis), pH, cathepsin B, cathepsin B+L activities, SDS-PAGE of sarcoplasmic and myofibrillar proteins, texture, and changes in microstructure of fillets at 4 °C and -3 °C were determined at 0, 2, 4, 8, 12, 24, 48, and 72 h after slaughter. The results indicated that pH of fillets (6.50 to 6.80) was appropriate for cathepsin function during the rigor mortis. For fillets that were chilled and partially frozen, the cathepsin activity in lysosome increased consistently during the first 12 h, followed by a decrease from the 12 to 24 h, which paralleled an increase in activity in heavy mitochondria, myofibrils and sarcoplasm. There was no significant difference in cathepsin activity in lysosomes between fillets at 4 °C and -3 °C (P > 0.05). Partially frozen fillets had greater cathepsin activity in heavy mitochondria than chilled samples from the 48 to 72 h. In addition, partially frozen fillets showed higher cathepsin activity in sarcoplasm and lower cathepsin activity in myofibrils compared with chilled fillets. Correspondingly, we observed degradation of α-actinin (105 kDa) by cathepsin L in chilled fillets and degradation of creatine kinase (41 kDa) by cathepsin B in partially frozen fillets during the rigor mortis. The decline of hardness for both fillets might be attributed to the accumulation of cathepsin in myofibrils from the 8 to 24 h. The lower cathepsin activity in myofibrils for fillets that were partially frozen might induce a more intact cytoskeletal structure than fillets that were chilled. © 2015 Institute of Food Technologists®

Identification of Differentially Expressed Genes in Chilling-Induced Potato (Solanum tuberosum L.); a Data Analysis Study.

PubMed

Koc, I; Vatansever, R; Ozyigit, I I; Filiz, E

2015-10-01

Cold stress, as chilling (<20 °C) or freezing (<0 °C), is one of the frequently exposed stresses in cultivated plants like potato. Under cold stress, plants differentially modulate their gene expression to develop a cold tolerance/acclimation. In the present study, we aimed to identify the overall gene expression profile of chilling-stressed (+4 °C) potato at four time points (4, 8, 12, and 48 h), with a particular emphasis on the genes related with transcription factors (TFs), phytohormones, lipid metabolism, signaling pathway, and photosynthesis. A total of 3504 differentially expressed genes (DEGs) were identified at four time points of chilling-induced potato, of which 1397 were found to be up-regulated while 2107 were down-regulated. Heatmap showed that genes were mainly up-regulated at 4-, 8-, and 12-h time points; however, at 48-h time point, they inclined to down-regulate. Seventy five up-regulated TF genes were identified from 37 different families/groups, including mainly from bHLH, WRKY, CCAAT-binding, HAP3, and bZIP families. Protein kinases and calcium were major signaling molecules in cold-induced signaling pathway. A collaborated regulation of phytohormones was observed in chilling-stressed potato. Lipid metabolisms were regulated in a way, highly probably, to change membrane composition to avoid cold damage and render in signaling. A down-regulated gene expression profile was observed in photosynthesis pathway, probably resulting from chilling-induced reduced enzyme activity or light-triggered ROSs damage. The findings of this study will be a valuable theoretical knowledge in terms of understanding the chilling-induced tolerance mechanisms in cultivated potato plants as well as in other Solanum species.

Transcriptional responses indicate maintenance of photosynthetic proteins as key to the exceptional chilling tolerance of C4 photosynthesis in Miscanthus × giganteus

PubMed Central

Spence, Ashley K.; Boddu, Jay; Wang, Dafu; James, Brandon; Swaminathan, Kankshita; Moose, Stephen P.; Long, Stephen P.

2014-01-01

Miscanthus × giganteus is exceptional among C4 plants in its ability to acclimate to chilling (≤14 °C) and maintain a high photosynthetic capacity, in sharp contrast to maize, leading to very high productivity even in cool temperate climates. To identify the mechanisms that underlie this acclimation, RNA was isolated from M × giganteus leaves in chilling and nonchilling conditions and hybridized to microarrays developed for its close relative Zea mays. Among 21 000 array probes that yielded robust signals, 723 showed significant expression change under chilling. Approximately half of these were for annotated genes. Thirty genes associated with chloroplast membrane function were all upregulated. Increases in transcripts for the lhcb5 (chlorophyll a/b-binding protein CP26), ndhF (NADH dehydrogenase F, chloroplast), atpA (ATP synthase alpha subunit), psbA (D1), petA (cytochrome f), and lhcb4 (chlorophyll a/b-binding protein CP29), relative to housekeeping genes in M. × giganteus, were confirmed by quantitative reverse-transcription PCR. In contrast, psbo1, lhcb5, psbA, and lhcb4 were all significantly decreased in Z. mays after 14 days of chilling. Western blot analysis of the D1 protein and LHCII type II chlorophyll a/b-binding protein also showed significant increases in M. × giganteus during chilling and significant decreases in Z. mays. Compared to other C4 species, M. × giganteus grown in chilling conditions appears to counteract the loss of photosynthetic proteins and proteins protecting photosystem II typically observed in other species by increasing mRNA levels for their synthesis. PMID:24958895

Suppression Subtractive Hybridization Analysis of Genes Regulated by Application of Exogenous Abscisic Acid in Pepper Plant (Capsicum annuum L.) Leaves under Chilling Stress

PubMed Central

Gong, Zhen-Hui; Yin, Yan-Xu; Li, Da-Wei

2013-01-01

Low temperature is one of the major factors limiting pepper (Capsicum annuum L.) production during winter and early spring in non-tropical regions. Application of exogenous abscisic acid (ABA) effectively alleviates the symptoms of chilling injury, such as wilting and formation of necrotic lesions on pepper leaves; however, the underlying molecular mechanism is not understood. The aim of this study was to identify genes that are differentially up- or downregulated in ABA-pretreated hot pepper seedlings incubated at 6°C for 48 h, using a suppression subtractive hybridization (SSH) method. A total of 235 high-quality ESTs were isolated, clustered and assembled into a collection of 73 unigenes including 18 contigs and 55 singletons. A total of 37 unigenes (50.68%) showed similarities to genes with known functions in the non-redundant database; the other 36 unigenes (49.32%) showed low similarities or unknown functions. Gene ontology analysis revealed that the 37 unigenes could be classified into nine functional categories. The expression profiles of 18 selected genes were analyzed using quantitative RT-PCR; the expression levels of 10 of these genes were at least two-fold higher in the ABA-pretreated seedlings under chilling stress than water-pretreated (control) plants under chilling stress. In contrast, the other eight genes were downregulated in ABA-pretreated seedlings under chilling stress, with expression levels that were one-third or less of the levels observed in control seedlings under chilling stress. These results suggest that ABA can positively and negatively regulate genes in pepper plants under chilling stress. PMID:23825555

Chilling-induced physiological, anatomical and biochemical responses in the leaves of Miscanthus × giganteus and maize (Zea mays L.).

PubMed

Bilska-Kos, Anna; Panek, Piotr; Szulc-Głaz, Anna; Ochodzki, Piotr; Cisło, Aneta; Zebrowski, Jacek

2018-06-08

Miscanthus × giganteus and Zea mays, closely-related C 4 grasses, originated from warm climates react differently to low temperature. To investigate the response to cold (12-14 °C) in these species, the photosynthetic and anatomical parameters as well as biochemical properties of the cell wall were studied. The research was performed using M. giganteus (MG) and two Z. mays lines differentiated for chilling-sensitivity: chilling-tolerant (Zm-T) and chilling-sensitive (Zm-S). The chilled plants of Zm-S line demonstrated strong inhibition of net CO 2 assimilation and a clear decrease in F' v /F' m , F v /F m and ɸ PSII, while in MG and Zm-T plants these parameters were almost unchanged. The anatomical studies revealed that MG plants had thinner leaves, epidermis and mesophyll cell layer as well as thicker cell walls in the comparison to both maize lines. Cold led to an increase in leaf thickness and mesophyll cell layer thickness in the Zm-T maize line, while the opposite response was observed in Zm-S. In turn, in chilled plants of MG and Zm-T lines, some anatomical parameters associated with bundle sheath cells were higher. In addition, Zm-S line showed the strong increase in the cell wall thickness at cold for mesophyll and bundle sheath cells. Chilling-treatment induced the changes in the cell wall biochemistry of tested species, mainly in the content of glucuronoarabinoxylan, uronic acid, β-glucan and phenolic compounds. This work presents a new approach in searching of mechanism(s) of tolerance/sensitivity to low temperature in two thermophilic plants: Miscanthus and maize. Copyright © 2018 Elsevier GmbH. All rights reserved.

Effect of high pressure treatment on microbiological quality of Indian white prawn (Fenneropenaeus indicus) during chilled storage.

PubMed

Ginson, J; Panda, Satyen Kumar; Bindu, J; Kamalakanth, C K; Srinivasa Gopal, T K

2015-04-01

High pressure treatment of 250 MPa for 6 min at 25 °C was applied to headless Indian white prawn (Fenneropenaeus indicus) to evaluate changes in microbiological characteristics of the species during chilled storage. Changes in load of mesophilic bacteria, psychrotrophic bacteria, proteolytic bacteria, Enterobacteriaceae, Pseudomonas spp., H2S producing bacteria, lactic acid bacteria, Brochothrix thermosphacta and yeast & mold were estimated in pressurized and un-pressurized samples during chilled storage. All microbes were reduced significantly after high pressure treatment and there was significant difference in microbial quality of control and high pressure treated samples in the entire duration of chilled storage (p < 0.05). There was delay in the growth of Enterobacteriaceae and H2S producing bacteria up to 6th and 9th day of storage, respectively in high pressure treated samples. In high pressure treated sample, no lag phase (λ) was observed for psychrotrophic bacteria, H2S producing bacteria, B. thermosphacta, Pseudomonas spp. and lactic acid bacteria; however, other bacteria showed a reduced lag phase during chilled storage. Kinetic parameter such as specific growth rate (μmax) in high pressure treated samples was significantly reduced in most of the bacterial groups except for psychrotrophic bacteria, Enterobacteriaceae and lactic acid bacteria. Mesophilic bacterial count of control samples crossed the marginal limit of acceptability on 12th day and unacceptable limit on 18th day of storage, whereas high pressure treated samples never breached the acceptability limit during entire duration of chilled storage. The present study indicated that application of high pressure processing can be used to improve microbial quality of Indian white prawn and extend the chilled storage life. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of different concentrations of egg yolk and virgin coconut oil in Tris-based extenders on chilled and frozen-thawed bull semen.

PubMed

Tarig, A A; Wahid, H; Rosnina, Y; Yimer, N; Goh, Y M; Baiee, F H; Khumran, A M; Salman, H; Ebrahimi, M

2017-07-01

The aim of this study was to evaluate the effects of 8% virgin coconut oil (VCO) combined with different percentages of egg yolk in Tris extender on the quality of chilled and frozen-thawed bull semen. A total of 24 ejaculates from four bulls were collected using an electroejaculator. Semen samples were diluted with 8% VCO in Tris extender which contained different concentrations 0% (control), 4%, 8%, 12%, 16% and 20% egg yolk. The diluted semen samples were divided into two fractions: one was chilled and stored at 4°C until evaluation after 24, 72, and 144h; the second fraction was processed by chilling for 3h at 4°C to equilibrate, then packaged in 0.25ml straws and frozen and stored in liquid nitrogen at -196°C until evaluation after 7 and 14 days. Both chilled and frozen semen samples were then thawed at 37°C and assessed for general motility using computer-assisted semen analysis (CASA), viability, acrosome integrity, and morphology (eosin-nigrosin), membrane integrity (hypo-osmotic swelling test) and lipid peroxidation (thiobarbituric acid-reactive substances (TBARS)). The results indicate treatments with 8%, 12%, 16% and 20% egg yolk with 8% VCO had greater sperm quality (P<0.05) as compared with the control. The treatment with 20% egg yolk had the greatest sperm quality (P<0.05) among the treated groups for both chilled and frozen-thawed semen. In conclusion, the use of 8% VCO combined with 20% egg yolk in a Tris-based extender enhanced the values for chilled and frozen-thawed quality variables of bull sperm. Copyright © 2017 Elsevier B.V. All rights reserved.

High-resistant castable corrosion-resistant nickel alloy for monocrystalline casting by the directional crystallization method

NASA Astrophysics Data System (ADS)

Belikov, S. B.; Andrienko, A. G.; Gaiduk, S. V.; Kononov, V. V.; Zamkovoi, V. E.

2008-01-01

A high-resistant corrosion-resistant nickel-based alloy has been developed for monocrystalline casting using the directional crystallization method. Its mechanical properties are close to those of aircraft alloys ZhS6K-VI and ZhS6U-VI with an equiaxial structure and ZhS26-VI with an oriented structure. The technology of producing blades for turboprop engines from the new alloy has been developed and tested.

Evaluation of food-relevant chemicals in the ToxCast high-throughput screening program.

PubMed

Karmaus, Agnes L; Filer, Dayne L; Martin, Matthew T; Houck, Keith A

2016-06-01

Thousands of chemicals are directly added to or come in contact with food, many of which have undergone little to no toxicological evaluation. The landscape of the food-relevant chemical universe was evaluated using cheminformatics, and subsequently the bioactivity of food-relevant chemicals across the publicly available ToxCast highthroughput screening program was assessed. In total, 8659 food-relevant chemicals were compiled including direct food additives, food contact substances, and pesticides. Of these food-relevant chemicals, 4719 had curated structure definition files amenable to defining chemical fingerprints, which were used to cluster chemicals using a selforganizing map approach. Pesticides, and direct food additives clustered apart from one another with food contact substances generally in between, supporting that these categories not only reflect different uses but also distinct chemistries. Subsequently, 1530 food-relevant chemicals were identified in ToxCast comprising 616 direct food additives, 371 food contact substances, and 543 pesticides. Bioactivity across ToxCast was filtered for cytotoxicity to identify selective chemical effects. Initiating analyses from strictly chemical-based methodology or bioactivity/cytotoxicity-driven evaluation presents unbiased approaches for prioritizing chemicals. Although bioactivity in vitro is not necessarily predictive of adverse effects in vivo, these data provide insight into chemical properties and cellular targets through which foodrelevant chemicals elicit bioactivity. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Can chilling tolerance of C 4 photosynthesis in Miscanthus be transferred to sugarcane?

DOE PAGES

Glowacka, Katarzyna; Ahmed, Aasifuddin; Sharma, Shailendra; ...

2015-07-29

Our goal is to investigate whether chilling tolerance of C 4 photosynthesis in Miscanthus can be transferred to sugarcane by hybridization. Net leaf CO 2 uptake (A sat) and we measured the maximum operating efficiency of photosystem II (Ф PSII) in warm conditions (25 °C/20 °C), and then during and following a chilling treatment of 10 °C/5 °C for 11 day in controlled environment chambers.

Changes in microbial communities and quality attributes of white muscle and dark muscle from common carp (Cyprinus carpio) during chilled and freeze-chilled storage.

PubMed

Li, Qian; Zhang, Longteng; Luo, Yongkang

2018-08-01

This study investigated sensory scores, quality attributes and microbial communities in white muscle and dark muscle of common carp (Cyprinus carpio) during chilled (4 °C) and freeze-chilled (-20 °C for 4 weeks prior to 4 °C) storage. Compared to the samples at the end of storage, fresh samples and frozen-thawed samples on day 0 showed greater bacterial diversity and more differences in microbiota. Initially, Aeromonas was the prevalent genus in fresh white muscle and dark muscle. As time progressed, Aeromonas followed by Pseudomonas predominated in white muscle, while Aeromonas, Pseudomonas, and Lactococcus dominated in dark muscle. Paenibacillus was identified as the largest population in frozen-thawed samples of both muscle types, but Pseudomonas increased dramatically to become dominant in the two spoiled samples. Volatile organic compounds (VOCs) of carp muscle consisted mainly of aldehydes and alcohols, and the percentage of ketones in both muscle types increased considerably after storage. Moreover, dark muscle showed more kinds of VOCs, and a slower rate of quality deterioration than white muscle. Based on sensory assessment, the shelf-life of white muscle and dark muscle of common carp for chilled storage was 8 days and 10 days, respectively, as well as 8 days together for freeze-chilled storage. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Study on the effect of different impression methods on the marginal fit of all-ceramic crowns].

PubMed

Zhan, Lilin; Zeng, Liwei; Chen, Ping; Liao, Lan; Li, Shiyue; Liu, Renying

2015-08-01

To investigate the effect of three different impression methods on the marginal fit of all-ceramic crowns. The three methods include scanning silicone rubber impression, cast models, and direct optical impression. The polymethyl methacrylate (PMMA) material of a mandibular first molar in standard model was prepared with 16 models duplicated. The all-ceramic crowns were prepared using three different impression methods. Accurate impressions were made using silicone rubber, and the cast models were obtained. The PMMA models, silicone rubber impressions, and cast models were scanned, and digital models of three groups were obtained to produce 48 zirconia all-ceramic crowns with computer aided design/computer aided manufacture. The marginal fit of these groups was measured by silicone rubber gap impression. Statistical analysis was performed with SPSS 17.0 software. The marginal fit of direct optical impression groups, silicone rubber impression groups, cast model groups was (69.18±9.47), (81.04±10.88), (84.42±9.96) µm. A significant difference was observed in the marginal fit of the direct optical impression groups and the other groups (P<0.05). No statistically significant difference was observed in the marginal fit of the silicone rubber impression groups and the cast model groups (P>0.05). All marginal measurement sites are clinically acceptable by the three different impression scanning methods. The silicone rubber impression scanning method can be used for all-ceramic restorations.

Sensory, physical and chemical characteristics of cooked ham manufactured from rapidly chilled and earlier deboned M. semimembranosus.

PubMed

Tomović, Vladimir M; Jokanović, Marija R; Petrović, Ljiljana S; Tomović, Mila S; Tasić, Tatjana A; Ikonić, Predrag M; Sumić, Zdravko M; Sojić, Branislav V; Skaljac, Snežana B; Sošo, Milena M

2013-01-01

Effects of rapid chilling of carcasses (at -31°C in the first 3h of chilling, and then at 2-4°C) and earlier deboning (8h post-mortem), compared to rapid (till 24h post-mortem) and conventional chilling (at 2-4°C, till 24h post-mortem), on quality characteristics of pork M. semimebranosus and cooked ham were investigated. Quality measurements included pH value, colour (CIEL a b values) and total aerobic count of M. semimebranosus, as well as sensory (colour, juiciness, texture, and flavour), physical (pH value, colour - CIEL a b values and texture - Warner-Bratzler shear and penetration forces) and chemical (protein, total fat, and moisture content) characteristics of cooked ham. The cooked ham was manufactured from pieces of M. semimebranosus with ultimate lightness (CIEL value) lower than 50. Rapid chilling and earlier deboning significantly increased quantity of M. semimebranosus desirable for cooked ham manufacturing. Earlier start of pork fabrication did not affect important quality characteristics of cooked ham. Copyright © 2012 Elsevier Ltd. All rights reserved.

Recovery of maize (Zea mays L.) inbreds and hybrids from chilling stress of various duration: photosynthesis and antioxidant enzymes.

PubMed

Holá, Dana; Kocová, Marie; Rothová, Olga; Wilhelmová, Nad'a; Benesová, Monika

2007-07-01

The differences between two maize (Zea mays L.) inbred lines and their F1 hybrids in their response to chilling periods of various duration (1, 2, 3 or 4 weeks) and subsequent return to optimum temperatures were analysed by the measurement of the photosystem (PS) 1 and 2 activity, the photosynthetic pigments' content and the activity of antioxidant enzymes. The PS2 activity and the chlorophyll content decreased in plants subjected to 3 or 4 weeks of chilling, but not in those subjected to 1 or 2 weeks of chilling. This decrease was more pronounced in inbreds compared to their hybrids. The activity of superoxide dismutase did not much change with the increasing length of chilling period in the inbreds but decreased in the hybrids, the glutathione reductase activity increased in both types of genotypes but more in the inbred lines, while for ascorbate peroxidase and catalase the changes in parents-hybrids relationship did not show any specific trend. The PS1 activity and the carotenoids' content was not much affected.

Biochemical, sensory and microbiological attributes of bream (Megalobrama amblycephala) during partial freezing and chilled storage.

PubMed

Song, Yongling; Luo, Yongkang; You, Juan; Shen, Huixing; Hu, Sumei

2012-01-15

Bream is one of the main farmed freshwater fish species in China. This study aimed to examine the nucleotide degradation of bream during partial freezing and chilled storage and to assess the possible usefulness of nucleotide ratios (K, Ki, H, P, Fr and G values) as freshness indices in comparison with sensory assessment and total viable counts. Total viable counts were 5.74 and 4.66 log(colony-forming units g(-1)) on the day of sensory rejection under chilled storage and partial freezing storage respectively. The inosine 5-monophosphate decrease and inosine increase were faster in chilled storage than in partial freezing storage. Hypoxanthine levels increased continuously with time under both storage regimes. Among the nucleotide ratios, the K, Ki, P, G and Fr values were superior to the H value and provided useful freshness indicators for both storage conditions. Bream in chilled storage were sensorially acceptable only up to 10 days, compared with 33 days for bream in partial freezing storage. Partial freezing delayed the nucleotide degradation of bream. Copyright © 2011 Society of Chemical Industry.

Large structural, thin-wall castings made of metals subject to hot tearing, and their fabrication

NASA Technical Reports Server (NTRS)

Smashey, Russell W. (Inventor)

2001-01-01

An article, such as a gas turbine engine mixer, is made by providing a mold structure defining a thin-walled, hollow article, and a base metal that is subject to hot tear cracking when cast in a generally equiaxed polycrystalline form, such as Rene' 108 and Mar-M247. The article is fabricated by introducing the molten base metal into the mold structure, and directionally solidifying the base metal in the mold structure to form a directionally oriented structure. The directionally oriented structure may be formed of a single grain or oriented multiple grains.

Texture and anisotropy in ferroelectric lead metaniobate

NASA Astrophysics Data System (ADS)

Iverson, Benjamin John

Ferroelectric lead metaniobate, PbNb2O6, is a piezoelectric ceramic typically used because of its elevated Curie temperature and anisotropic properties. However, the piezoelectric constant, d33, is relatively low in randomly oriented ceramics when compared to other ferroelectrics. Crystallographic texturing is often employed to increase the piezoelectric constant because the spontaneous polarization axes of grains are better aligned. In this research, crystallographic textures induced through tape casting are distinguished from textures induced through electrical poling. Texture is described using multiple quantitative approaches utilizing X-ray and neutron time-of-flight diffraction. Tape casting lead metaniobate with an inclusion of acicular template particles induces an orthotropic texture distribution. Templated grain growth from seed particles oriented during casting results in anisotropic grain structures. The degree of preferred orientation is directly linked to the shear behavior of the tape cast slurry. Increases in template concentration, slurry viscosity, and casting velocity lead to larger textures by inducing more particle orientation in the tape casting plane. The maximum 010 texture distributions were two and a half multiples of a random distribution. Ferroelectric texture was induced by electrical poling. Electric poling increases the volume of material oriented with the spontaneous polarization direction in the material. Samples with an initial paraelectric texture exhibit a greater change in the domain volume fraction during electrical poling than randomly oriented ceramics. In tape cast samples, the resulting piezoelectric response is proportional to the 010 texture present prior to poling. This results in property anisotropy dependent on initial texture. Piezoelectric properties measured on the most textured ceramics were similar to those obtained with a commercial standard.

Oxidative Stress Associated with Chilling Injury in Immature Fruit: Postharvest Technological and Biotechnological Solutions.

PubMed

Valenzuela, Juan Luis; Manzano, Susana; Palma, Francisco; Carvajal, Fátima; Garrido, Dolores; Jamilena, Manuel

2017-07-08

Immature, vegetable-like fruits are produced by crops of great economic importance, including cucumbers, zucchini, eggplants and bell peppers, among others. Because of their high respiration rates, associated with high rates of dehydration and metabolism, and their susceptibility to chilling injury (CI), vegetable fruits are highly perishable commodities, requiring particular storage conditions to avoid postharvest losses. This review focuses on the oxidative stress that affects the postharvest quality of vegetable fruits under chilling storage. We define the physiological and biochemical factors that are associated with the oxidative stress and the development of CI symptoms in these commodities, and discuss the different physical, chemical and biotechnological approaches that have been proposed to reduce oxidative stress while enhancing the chilling tolerance of vegetable fruits.

Optimum Temperature for Storage of Fruit and Vegetables with Reference to Chilling Injury

NASA Astrophysics Data System (ADS)

Murata, Takao

Cold storage is an important technique for preserving fresh fruit and vegetables. Deterioration due to ripening, senescence and microbiological disease can be retarded by storage at optimum temperature being slightly above the freezing point of tissues of fruit and vegetables. However, some fruit and vegetables having their origins in tropical or subtropical regions of the world are subject to chilling injury during transportation, storage and wholesale distribution at low temperature above freezing point, because they are usually sensitive to low temperature in the range of 15&digC to 0°C. This review will focus on the recent informations regarding chilling injury of fruit and vegetables, and summarize the optimum temperature for transportation and storage of fruit and vegetables in relation to chilling injury.

Oxidative Stress Associated with Chilling Injury in Immature Fruit: Postharvest Technological and Biotechnological Solutions

PubMed Central

Valenzuela, Juan Luis; Manzano, Susana; Palma, Francisco; Carvajal, Fátima; Jamilena, Manuel

2017-01-01

Immature, vegetable-like fruits are produced by crops of great economic importance, including cucumbers, zucchini, eggplants and bell peppers, among others. Because of their high respiration rates, associated with high rates of dehydration and metabolism, and their susceptibility to chilling injury (CI), vegetable fruits are highly perishable commodities, requiring particular storage conditions to avoid postharvest losses. This review focuses on the oxidative stress that affects the postharvest quality of vegetable fruits under chilling storage. We define the physiological and biochemical factors that are associated with the oxidative stress and the development of CI symptoms in these commodities, and discuss the different physical, chemical and biotechnological approaches that have been proposed to reduce oxidative stress while enhancing the chilling tolerance of vegetable fruits. PMID:28698472

40 CFR 471.25 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... million off-pounds) of magnesium rolled with emulsions Chromium 0.028 0.011 Zinc 0.076 0.032 Ammonia 9.95... forged magnesium cooled with water Chromium 0.107 0.044 Zinc 0.295 0.122 Ammonia 38.5 17.0 Fluoride 17.2... forged Chromium 0.002 0.0006 Zinc 0.004 0.002 Ammonia 0.532 0.234 Fluoride 0.238 0.106 (e) Direct chill...

40 CFR 471.25 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... million off-pounds) of magnesium rolled with emulsions Chromium 0.028 0.011 Zinc 0.076 0.032 Ammonia 9.95... forged magnesium cooled with water Chromium 0.107 0.044 Zinc 0.295 0.122 Ammonia 38.5 17.0 Fluoride 17.2... forged Chromium 0.002 0.0006 Zinc 0.004 0.002 Ammonia 0.532 0.234 Fluoride 0.238 0.106 (e) Direct chill...

40 CFR 471.25 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... million off-pounds) of magnesium rolled with emulsions Chromium 0.028 0.011 Zinc 0.076 0.032 Ammonia 9.95... forged magnesium cooled with water Chromium 0.107 0.044 Zinc 0.295 0.122 Ammonia 38.5 17.0 Fluoride 17.2... forged Chromium 0.002 0.0006 Zinc 0.004 0.002 Ammonia 0.532 0.234 Fluoride 0.238 0.106 (e) Direct chill...

40 CFR 471.25 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... million off-pounds) of magnesium rolled with emulsions Chromium 0.028 0.011 Zinc 0.076 0.032 Ammonia 9.95... forged magnesium cooled with water Chromium 0.107 0.044 Zinc 0.295 0.122 Ammonia 38.5 17.0 Fluoride 17.2... forged Chromium 0.002 0.0006 Zinc 0.004 0.002 Ammonia 0.532 0.234 Fluoride 0.238 0.106 (e) Direct chill...

40 CFR 471.25 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... million off-pounds) of magnesium rolled with emulsions Chromium 0.028 0.011 Zinc 0.076 0.032 Ammonia 9.95... forged magnesium cooled with water Chromium 0.107 0.044 Zinc 0.295 0.122 Ammonia 38.5 17.0 Fluoride 17.2... forged Chromium 0.002 0.0006 Zinc 0.004 0.002 Ammonia 0.532 0.234 Fluoride 0.238 0.106 (e) Direct chill...

Automated Continuous Commissioning of Commercial Buildings

DTIC Science & Technology

2011-09-01

matched pair of supply and return chilled water temperature sensors, a pyranometer , and aspirated wet and dry bulb temperature sensors for the weather...temp X Aspirated weather station is required. Outside air wet bulb X Pyranometer X Wind speed & direction X Main power meter X Lighting load power X...Aspirated weather station is required. Outside air wet bulb X Pyranometer X Provides measurements on global horizontal solar radiation, beam radiation and

Applicability of Thermal Storage Systems to Air Force Facilities

DTIC Science & Technology

1990-09-01

Analisis of Region 6 Upper Limit Retrofit Scenario 30% Reduction .... ............. 4.52 4.58 Economic Analysis of Region 7 Upper Limit Retrofit Scenario...or a dynamic-direct contact type. They usually include all the controls, chilling and storage equipment in one self-contained, skid mounted, factory ...SCS technology. One promising trend in reducing system construction costs is the factory -packaged thermal storage cooling unit. As of February 1989

Predictive model for Clostridium perfringens growth in roast beef during cooling and inhibition of spore germination and outgrowth by organic acid salts.

PubMed

Sánchez-Plata, Marcos X; Amézquita, Alejandro; Blankenship, Erin; Burson, Dennis E; Juneja, Vijay; Thippareddi, Harshavardhan

2005-12-01

Spores of foodborne pathogens can survive traditional thermal processing schedules used in the manufacturing of processed meat products. Heat-activated spores can germinate and grow to hazardous levels when these products are improperly chilled. Germination and outgrowth of Clostridium perfringens spores in roast beef during chilling was studied following simulated cooling schedules normally used in the processed-meat industry. Inhibitory effects of organic acid salts on germination and outgrowth of C. perfringens spores during chilling and the survival of vegetative cells and spores under abusive refrigerated storage was also evaluated. Beef top rounds were formulated to contain a marinade (finished product concentrations: 1% salt, 0.2% potassium tetrapyrophosphate, and 0.2% starch) and then ground and mixed with antimicrobials (sodium lactate and sodium lactate plus 2.5% sodium diacetate and buffered sodium citrate and buffered sodium citrate plus 1.3% sodium diacetate). The ground product was inoculated with a three-strain cocktail of C. perfringens spores (NCTC 8238, NCTC 8239, and ATCC 10388), mixed, vacuum packaged, heat shocked for 20 min at 75 degrees C, and chilled exponentially from 54.5 to 7.2 degrees C in 9, 12, 15, 18, or 21 h. C. perfringens populations (total and spore) were enumerated after heat shock, during chilling, and during storage for up to 60 days at 10 degrees C using tryptose-sulfite-cycloserine agar. C. perfringens spores were able to germinate and grow in roast beef (control, without any antimicrobials) from an initial population of ca. 3.1 log CFU/g by 2.00, 3.44, 4.04, 4.86, and 5.72 log CFU/g after 9, 12, 15, 18, and 21 h of exponential chilling. A predictive model was developed to describe sigmoidal C. perfringens growth curves during cooling of roast beef from 54.5 to 7.2 degrees C within 9, 12, 15, 18, and 21 h. Addition of antimicrobials prevented germination and outgrowth of C. perfringens regardless of the chill times. C. perfringens spores could be recovered from samples containing organic acid salts that were stored up to 60 days at 10 degrees C. Extension of chilling time to > or =9 h resulted in >1 log CFU/g growth of C. perfringens under anaerobic conditions in roast beef. Organic acid salts inhibited outgrowth of C. perfringens spores during chilling of roast beef when extended chill rates were followed. Although C. perfringens spore germination is inhibited by the antimicrobials, this inhibition may represent a hazard when such products are incorporated into new products, such as soups and chili, that do not contain these antimicrobials, thus allowing spore germination and outgrowth under conditions of temperature abuse.

Low-cost directionally-solidified turbine blades, volume 1

NASA Technical Reports Server (NTRS)

Sink, L. W.; Hoppin, G. S., III; Fujii, M.

1979-01-01

A low cost process of manufacturing high stress rupture strength directionally-solidified high pressure turbine blades was successfully developed for the TFE731-3 Turbofan Engine. The basic processing parameters were established using MAR-M 247 and employing the exothermic directional-solidification process in trial castings of turbine blades. Nickel-based alloys were evaluated as directionally-solidified cast blades. A new turbine blade, disk, and associated components were then designed using previously determined material properties. Engine tests were run and the results were analyzed and compared to the originally established goals. The results showed that the stress rupture strength of exothermically heated, directionally-solidified MAR-M 247 turbine blades exceeded program objectives and that the performance and cost reduction goals were achieved.

Design Guidance for Command, Control, Communications, and Intelligence (C3I) Facility Cooling Systems

DTIC Science & Technology

1989-05-01

Typical ranges are from 50 to 70 OF. If a chiller is dedicated to serving water-cooled electronic equipment, the chilled water temperature setpoint can...can be satisfied with 50 OF chilled water. The COP of the dedicated chiller is improved by raising the chilled water setpoint , and the total life-cycle...USACERL TECHNICAL REPORT E-89/10 May 1989 Studies in Optimizing HVAC Hardware for C31 Facilities US Army Corps of Engineers Construction Engineering

Within-year Exertional Heat Illness Incidence in U.S. Army Soldiers, 2008-2012

DTIC Science & Technology

2015-06-01

index (MDI;(17)) were created. Wind speed (in kph) was calculated as wind speed (in mph)*1.61. Wind chill was calculated for all climate samples...downloaded from the NOAA website, new variables for wind speed (converted from mph to kph), wind chill , minimum temperature, and modified discomfort...Windspeed_Kph** 0.16 + 0.3965 * DryBulbCelsius * Windspeed_Kph ** 0.16. Dry bulb temperatures (in °C) and wind chill temperatures (in °C) were

Vented Chill / No-Vent Fill of Cryogenic Propellant Tanks

NASA Technical Reports Server (NTRS)

Rhys, Noah O.; Foster, Lee W.; Martin, Adam K.; Stephens, Jonathan R.

2016-01-01

Architectures for extended duration missions often include an on-orbit replenishment of the space vehicle's cryogenic liquid propellants. Such a replenishment could be accomplished via a tank-to-tank transfer from a dedicated tanker or a more permanent propellant depot storage tank. Minimizing the propellant loss associated with transfer line and receiver propellant tank thermal conditioning is essential for mass savings. A new methodology for conducting tank-to-tank transfer while minimizing such losses has been demonstrated. Charge-Hold-Vent is the traditional methodology for conducting a tank-to-tank propellant transfer. A small amount of cryogenic liquid is introduced to chill the transfer line and propellant tank. As the propellant absorbs heat and undergoes a phase change, the tank internal pressure increases. The tank is then vented to relieve pressure prior to another charge of cryogenic liquid being introduced. This cycle is repeated until the transfer lines and tank are sufficiently chilled and the replenishment of the propellant tank is complete. This method suffers inefficiencies due to multiple chill and vent cycles within the transfer lines and associated feed system components. Additionally, this system requires precise measuring of cryogenic fluid delivery for each transfer, multiple valve cycling events, and other complexities associated with cycled operations. To minimize propellant loss and greatly simplify on-orbit operations, an alternate methodology has been designed and demonstrated. The Vented Chill / No Vent Fill method is a simpler, constant flow approach in which the propellant tank and transfer lines are only chilled once. The receiver tank is continuously vented as cryogenic liquid chills the transfer lines, tank mass and ullage space. Once chilled sufficiently, the receiver tank valve is closed and the tank is completely filled. Interestingly, the vent valve can be closed prior to receiver tank components reaching liquid saturation temperature. An incomplete fill results if insufficient energy is removed from the tank's thermal mass and ullage space. The key to successfully conducting the no vent fill is to assure that sufficient energy is removed from the system prior to closing the receiver tank vent valve. This paper will provide a description of the transfer methodology and test article, and will provide a discussion of test results.

Evaluation of food-relevant chemicals in the ToxCast high-throughput screening program

EPA Science Inventory

There are thousands of chemicals that are directly added to or come in contact with food, many of which have undergone little to no toxicological evaluation. The ToxCast high-throughput screening (HTS) program has evaluated over 1,800 chemicals in concentration-response across ~8...

A new method to evaluate the quality of single crystal Cu by an X-ray diffraction butterfly pattern method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu Zhenming; Guo Zhenqi; Li Jianguo

2004-12-15

A new method for the evaluation of the quality of an Ohno continuous cast (OCC) Cu single crystal by X-ray diffraction (XRD) butterfly pattern was brought forward. Experimental results show that the growth direction of single crystal Cu is inclined from both sides of the single crystal Cu rod to the axis and is axially symmetric. The degree of deviation from the [100] orientation from the crystal axis is less than 5 deg. with a casting speed 10-40 mm/min. The orientation of single crystal Cu does not have a fixed direction but is in a regular range. Moreover, the orientationmore » of stray grains in the single crystal Cu is random from continuous casting.« less

3D analysis of macrosegregation in twin-roll cast AA3003 alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Šlapáková, Michaela, E-mail: slapakova@karlov.mff.

Twin-roll cast aluminium alloys have a high potential for industrial applications. However, one of the drawbacks of such materials is an inhomogeneous structure generated by macrosegregation, which appears under certain conditions in the center of sheets during solidification. Segregations in AA3003 alloy form as manganese, iron and silicon rich channels spread in the rolling direction. Their spatial distribution was successfully detected by X-ray computed tomography. Scanning electron microscopy was used for a detailed observation of microstructure, morphology and chemical analysis of the segregation. - Highlights: •Macrosegregations in twin-roll cast sheets stretch along the rolling direction. •X-ray computed tomography is anmore » effective tool for visualization of the segregation. •The segregations copy the shape of grain boundaries.« less

Manufacturing Processes for Long-Life Gas Turbines

NASA Astrophysics Data System (ADS)

Hoppin, G. S.; Danesi, W. P.

1986-07-01

Dual-alloy turbine wheels produced by solid-state diffusion bonding of vacuum investment cast blade rings of one superalloy to preconsolidated powder metal hubs of a second superalloy have the long cyclic lives characteristic of wrought or powder superalloys combined with the high creep strength and net-shape blades characteristic of cast superalloys. A wide variety of superalloys and turbine configurations are compatible with this technology. Improved temperature capability turbine blades and vanes of the MAR-M 247 alloy made by directional solidification casting processes are now in volume production for Garrett gas turbines. Single-crystal alloys derivative to MAR-M 247 further extend the temperature capability of turbine blades and have been successfully engine tested. These blades are produced by a relatively simple modification of the processes used to manufacture directionally solidified blades.

Does the casting mode influence microstructure, fracture and properties of different metal ceramic alloys?

PubMed

Bauer, José Roberto de Oliveira; Grande, Rosa Helena Miranda; Rodrigues-Filho, Leonardo Eloy; Pinto, Marcelo Mendes; Loguercio, Alessandro Dourado

2012-01-01

The aim of the present study was to evaluate the tensile strength, elongation, microhardness, microstructure and fracture pattern of various metal ceramic alloys cast under different casting conditions. Two Ni-Cr alloys, Co-Cr and Pd-Ag were used. The casting conditions were as follows: electromagnetic induction under argon atmosphere, vacuum, using blowtorch without atmosphere control. For each condition, 16 specimens, each measuring 25 mm long and 2.5 mm in diameter, were obtained. Ultimate tensile strength (UTS) and elongation (EL) tests were performed using a Kratos machine. Vickers Microhardness (VM), fracture mode and microstructure were analyzed by SEM. UTS, EL and VM data were statistically analyzed using ANOVA. For UTS, alloy composition had a direct influence on casting condition of alloys (Wiron 99 and Remanium CD), with higher values shown when cast with Flame/Air (p < 0.05). The factors 'alloy" and 'casting condition" influenced the EL and VM results, generally presenting opposite results, i.e., alloy with high elongation value had lower hardness (Wiron 99), and casting condition with the lowest EL values had the highest VM values (blowtorch). Both factors had significant influence on the properties evaluated, and prosthetic laboratories should select the appropriate casting method for each alloy composition to obtain the desired property.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

DOE PAGES

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; ...

2018-04-25

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatmentmore » line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. Furthermore, this work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.« less

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

NASA Astrophysics Data System (ADS)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

2018-06-01

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

NASA Astrophysics Data System (ADS)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

2018-04-01

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatmentmore » line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. Furthermore, this work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.« less

Chilling Out With Colds

MedlinePlus

... and use the time to read, listen to music, or watch a movie. In other words, chill out and you might prevent a cold! Reviewed by: Patricia ... Policy Permissions Guidelines Privacy Policy & Terms of Use Notice ...

Involvement of calcium and calmodulin in oxidative and temperature stress of Amaranthus lividus L. during early germination.

PubMed

Bhattacharjee, Soumen

2009-07-01

Both heat and chilling caused reduction in membrane protein thiol level and increased accumulation of thiobarbituric acid reactive substances in 72 hr old germinating tissues (indicators of oxidative stress) and reduced germination and early growth performances. Calcium chelator EGTA [Ethylene glycol-bis (2-aminoethylether)-N, N,N',N, tetra acetic acid] calcium channel blocker LaCI3 (Lanthanum chloride) and calmodulin inhibitor TFP (trifluroperazine) aggravated these effects of heat and chilling and added calcium reversed them. Imposition of heat and chilling stress during early germination also causes accumulation of reactive oxygen species (ROS) like 02(-) and H2O2. Calcium treatment significantly reduced the accumulation of both the toxic ROS, while EGTA, LaCl3 and TFP treatment enhanced the accumulation. Activities of antioxidative enzymes catalase (CAT), ascorbate peroxidase (APOX) and glutathione reductase (GR) and total thiol content decreased significantly under both heat and chilling stress in germinating Amaranthus seedlings. Seedlings raised with Ca2+ treatment under heat and chilling stress exhibit higher activities of CAT7 GR and APOX and total thiol level than the untreated plants. EGTA, LaCl3 and TFP treatment, on the other hand significantly reduce the activities of all anti-oxidative enzymes and total thiol level. The work clearly supports the view that Ca2+-signalling pathway plays significant role in limiting heat and chilling induced oxidative stress by upregulating antioxidative defense during recovery phase of post-germination event in Amaranthus lividus.

Immunodetection of nucleolar proteins and ultrastructure of nucleoli of soybean root meristematic cells treated with chilling stress and after recovery.

PubMed

Stepiński, Dariusz

2009-03-01

The nucleolar proteins, fibrillarin and nucleophosmin, have been identified immunofluorescently in the root meristematic cells of soybean seedlings under varying experimental conditions: at 25 degrees C (control), chilling at 10 degrees C for 3 h and 4 days and recovery from the chilling stress at 25 degrees C. In each experimental variant, the immunofluorescence signals were present solely at the nucleolar territories. Fluorescent staining for both proteins was mainly in the shape of circular domains that are assumed to correspond to the dense fibrillar component of the nucleoli. The fewest fluorescent domains were observed in the nucleoli of chilled plants, and the highest number was observed in the plants recovered after chilling. This difference in the number of circular domains in the nucleoli of each variant may indicate various levels of these proteins in each variant. Both the number of circular domains and the level of these nucleolar proteins changed with changes in the transcriptional activity of the nucleoli, with the more metabolically active cell having higher numbers of active areas in the nucleolus and higher levels of nucleolar proteins, and conversely. Electron microscopic studies revealed differences in the ultrastructure of the nucleoli in all experimental variants and confirmed that the number of fibrillar centres surrounded by dense fibrillar component was the lowest in the nucleoli of chilled plants, and the highest in the nucleoli of recovered seedlings.

Significant reduction in the incidence of C5 palsy after cervical laminoplasty using chilled irrigation water.

PubMed

Takenaka, S; Hosono, N; Mukai, Y; Tateishi, K; Fuji, T

2016-01-01

The aim of this study was to determine whether chilled irrigation saline decreases the incidence of clinical upper limb palsy (ULP; a reduction of one grade or more on manual muscle testing; MMT), based on the idea that ULP results from thermal damage to the nerve roots by heat generated by friction during bone drilling. Irrigation saline for drilling was used at room temperature (RT, 25.6°C) in open-door laminoplasty in 400 patients (RT group) and chilled to a mean temperature of 12.1°C during operations for 400 patients (low-temperature (LT) group). We assessed deltoid, biceps, and triceps brachii muscle strength by MMT. ULP occurring within two days post-operatively was categorised as early-onset palsy. The incidence of ULP (4.0% vs 9.5%, p = 0.003), especially early-onset palsy (1.0% vs 5.5%, p < 0.001), was significantly lower for the LT group than for the RT group. Multivariate analysis indicated that RT irrigation saline use, concomitant foraminotomy, and opened side were significant predictors for ULP. Using chilled irrigation saline during bone drilling significantly decreased the ULP incidence, particularly the early-onset type, and shortened the recovery period for ULP. Chilled irrigation saline can thus be recommended as a simple method for preventing ULP. Chilled irrigation during laminoplasty reduces C5 palsy. ©2016 The British Editorial Society of Bone & Joint Surgery.

The influence of chilling requirement on the southern distribution limit of exotic Russian olive (Elaeagnus angustifolia) in western North America

USGS Publications Warehouse

Guilbault, Kimberly R.; Brown, C.S.; Friedman, J.M.; Shafroth, P.B.

2012-01-01

Russian olive (Elaeagnus angustifolia L.), a Eurasian tree now abundant along rivers in western North America, has an apparent southern distribution limit running through southern California, Arizona, New Mexico and Texas. We used field observations to precisely define this limit in relation to temperature variables. We then investigated whether lack of cold temperatures south of the limit may prevent the accumulation of sufficient chilling, inhibiting dormancy loss of seeds and buds. We found that Russian olive occurrence was more strongly associated with low winter temperatures than with high summer temperatures, and results of controlled seed germination and vegetative bud-break experiments suggest that the chilling requirements for germination and bud-break are partly responsible for the southern range limit. Both seed germination proportion and germination time decreased under conditions simulating those south of the range limit. Similarly, percentage bud break decreased when chilling dropped below values typical of the range limit. In 17–65% of the years from 1980 to 2000, the chilling accumulated at a site near the range limit (El Paso, TX) would lead to a 10% or more decrease in bud-break. The potential decline in growth could have large fitness consequences for Russian olive. If climate change exhibits a warming trend, our results suggest the chilling requirement for bud-break of Russian olive trees will not be met in some years and its southern range limit may retreat northward.

High-resolution mapping of a major effect QTL from wild tomato Solanum habrochaites that influences water relations under root chilling.

PubMed

Arms, Erin M; Bloom, Arnold J; St Clair, Dina A

2015-09-01

QTL stm9 controlling rapid-onset water stress tolerance in S. habrochaites was high-resolution mapped to a chromosome 9 region that contains genes associated with abiotic stress tolerances. Wild tomato (Solanum habrochaites) exhibits tolerance to abiotic stresses, including drought and chilling. Root chilling (6 °C) induces rapid-onset water stress by impeding water movement from roots to shoots. S. habrochaites responds to such changes by closing stomata and maintaining shoot turgor, while cultivated tomato (S. lycopersicum) fails to close stomata and wilts. This response (shoot turgor maintenance under root chilling) is controlled by a major QTL (designated stm9) on chromosome 9, which was previously fine-mapped to a 2.7-cM region. Recombinant sub-near-isogenic lines for chromosome 9 were marker-selected, phenotyped for shoot turgor maintenance under root chilling in two sets of replicated experiments (Fall and Spring), and the data were used to high-resolution map QTL stm9 to a 0.32-cM region. QTL mapping revealed a single QTL that was coincident for both the Spring and Fall datasets, suggesting that the gene or genes contributing to shoot turgor maintenance under root chilling reside within the marker interval H9-T1673. In the S. lycopersicum reference genome sequence, this chromosome 9 region is gene-rich and contains representatives of gene families that have been associated with abiotic stress tolerance.

Studying Wind Chill Index as a Climatic Index Effective on the Health of Athletes and Tourists Interested in Winter Sports

PubMed Central

Roshan, Gholamreza; Mirkatouli, Gafar; Shakoor, Ali; Mohammad-Nejad, Vahid

2010-01-01

Purpose Estimating wind chill index as one of the indexes effective in body comfort, specifically for athletes and tourists interested in winter sports. Methods Meteorology data including temperature and the percentage of relative humidity of 6 synoptic stations of Chaharmahal-Bakhtiyrai province, Iran from 1990 to 2007 were extracted from Iranian Meteorology Site. In order to calculate the values of wind chill, the innovative formula of NOAA Meteorology Services Center [T (WC)= 35.74+0.6215T-35.75V+0.4275TV] was used. Results After analyzing wind in all stations, it became evident that the great percentage of wind calm related to fall, and spring had the most wind distortions. In studying the mean temperature during this studying period, Koohrang station with mean of 9.8°C was identified as the coldest station and Lordegan with a mean of 17°C represented the warmest station of the region observed. According to degrees derived from wind chill index, Koohrang station in January with a mean of −28.75 was known as the coldest and roughest station. Conclusion Among the studied stations, Koohrang had the most intensive degrees of wind chill occurrence and Lordegan had the calmest conditions. Therefore, athletes and tourists should use warmer clothes and covers in cold seasons in Koohrang in comparison with other studied regions, in order to protect themselves from the negative effects of sudden cold and occurrence of intense wind chills. PMID:22375198

Identification of Clathrate Hydrates, Hexagonal Ice, Cubic Ice, and Liquid Water in Simulations: the CHILL+ Algorithm.

PubMed

Nguyen, Andrew H; Molinero, Valeria

2015-07-23

Clathrate hydrates and ice I are the most abundant crystals of water. The study of their nucleation, growth, and decomposition using molecular simulations requires an accurate and efficient algorithm that distinguishes water molecules that belong to each of these crystals and the liquid phase. Existing algorithms identify ice or clathrates, but not both. This poses a challenge for cases in which ice and hydrate coexist, such as in the synthesis of clathrates from ice and the formation of ice from clathrates during self-preservation of methane hydrates. Here we present an efficient algorithm for the identification of clathrate hydrates, hexagonal ice, cubic ice, and liquid water in molecular simulations. CHILL+ uses the number of staggered and eclipsed water-water bonds to identify water molecules in cubic ice, hexagonal ice, and clathrate hydrate. CHILL+ is an extension of CHILL (Moore et al. Phys. Chem. Chem. Phys. 2010, 12, 4124-4134), which identifies hexagonal and cubic ice but not clathrates. In addition to the identification of hydrates, CHILL+ significantly improves the detection of hexagonal ice up to its melting point. We validate the use of CHILL+ for the identification of stacking faults in ice and the nucleation and growth of clathrate hydrates. To our knowledge, this is the first algorithm that allows for the simultaneous identification of ice and clathrate hydrates, and it does so in a way that is competitive with respect to existing methods used to identify any of these crystals.

Development of a New Ferrous Aluminosilicate Refractory Material for Investment Casting of Aluminum Alloys

NASA Astrophysics Data System (ADS)

Yuan, Chen; Jones, Sam; Blackburn, Stuart

2012-12-01

Investment casting is a time-consuming, labour intensive process, which produces complex, high value-added components for a variety of specialised industries. Current environmental and economic pressures have resulted in a need for the industry to improve current casting quality, reduce manufacturing costs and explore new markets for the process. Alumino-silicate based refractories are commonly used as both filler and stucco materials for ceramic shell production. A new ceramic material, norite, is now being produced based on ferrous aluminosilicate chemistry, having many potential advantages when used for the production of shell molds for casting aluminum alloy. This paper details the results of a direct comparison made between the properties of a ceramic shell system produced with norite refractories and a typical standard refractory shell system commonly used in casting industry. A range of mechanical and physical properties of the systems was measured, and a full-scale industrial casting trial was also carried out. The unique properties of the norite shell system make it a promising alternative for casting aluminum based alloys in the investment foundry.

Changes in SBPase activity influence photosynthetic capacity, growth, and tolerance to chilling stress in transgenic tomato plants

PubMed Central

Ding, Fei; Wang, Meiling; Zhang, Shuoxin; Ai, Xizhen

2016-01-01

Sedoheptulose-1, 7-bisphosphatase (SBPase) is an important enzyme involved in photosynthetic carbon fixation in the Calvin cycle. Here, we report the impact of changes in SBPase activity on photosynthesis, growth and development, and chilling tolerance in SBPase antisense and sense transgenic tomato (Solanum lycopersicum) plants. In transgenic plants with increased SBPase activity, photosynthetic rates were increased and in parallel an increase in sucrose and starch accumulation was evident. Total biomass and leaf area were increased in SBPase sense plants, while they were reduced in SBPase antisense plants compared with equivalent wild-type tomato plants. Under chilling stress, when compared with plants with decreased SBPase activity, tomato plants with increased SBPase activity were found to be more chilling tolerant as indicated by reduced electrolyte leakage, increased photosynthetic capacity, and elevated RuBP regeneration rate and quantum efficiency of photosystem II. Collectively, our data suggest that higher level of SBPase activity gives an advantage to photosynthesis, growth and chilling tolerance in tomato plants. This work also provides a case study that an individual enzyme in the Calvin cycle may serve as a useful target for genetic engineering to improve production and stress tolerance in crops. PMID:27586456

The responses of antioxidant system in bitter melon, sponge gourd, and winter squash under flooding and chilling stresses

NASA Astrophysics Data System (ADS)

Do, Tuong Ha; Nguyen, Hoang Chinh; Lin, Kuan-Hung

2018-04-01

The objective of this paper was to review the responses of antioxidant system and physiological parameters of bitter melon (BM), sponge gourd (SG), and winter squash (WS) under waterlogged and low temperature conditions. The BM and SG plants were subjected to 0-72 h flooding treatments, and BM and WS plants were exposed to chilling at 12/7 °C (day/night) for 0-72 h. Different genotypes responded differently to environmental stress according to their various antioxidant system and physiological parameters. Increased ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities provided SG and WS plants with increased waterlogging and chilling stress tolerance, respectively, compared to BM plants. The APX gene from SG and the SOD gene from WS were then cloned, and the regulation of APX and SOD gene expressions under flooding and chilling stress, respectively, were also measured. Increased expression of APX and SOD genes was accompanied by the increased activity of the enzyme involved in detoxifying reactive oxygen species (ROS) in response to those stresses. Both APX and SOD activities can be used for selecting BM lines with the best tolerances to water logging and chilling stresses.

Effect of long term chilled (up to 5weeks) then frozen (up to 12months) storage at two different sub-zero holding temperatures on beef: 2. Lipid oxidation and fatty acid profiles.

PubMed

Holman, Benjamin W B; Coombs, Cassius E O; Morris, Stephen; Bailes, Kristy; Hopkins, David L

2018-02-01

Lipid oxidation and fatty acid (FA) profiles were evaluated for beef M. longissimus lumborum (LL) stored under different chilled-then-frozen storage combinations (up to 5 and 52weeks, respectively) and two frozen holding temperatures (-12°C and -18°C). FA profile variation was observed, with increasing frozen storage periods resulting in unsaturated FA levels declining as saturated FA levels increased. Polyunsaturated and health claimable FA levels also tended to decline with increasing chilled storage period, albeit insignificant within the constraints of the experimental design. Peroxidase activity, TBARS and oxidation-reduction potential analyses reflected these FA changes. These, when compared against existing consumer thresholds, suggest a perceptible detraction from LL held under long-term frozen storage durations that are less evident earlier as dependent on the preceding chilled storage period. Negligible impact of frozen storage holding temperatures was observed on measured traits. These results suggest long-term chilled-then-frozen storage can influence beef lipid stability, healthy FA profile and therefore the healthiness of beef. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Effects of chilled-then-frozen storage (up to 52weeks) on an indicator of protein oxidation and indices of protein degradation in lamb M. longissimus lumborum.

PubMed

Coombs, Cassius E O; Holman, Benjamin W B; Collins, Damian; Kerr, Matthew J; Friend, Michael A; Hopkins, David L

2018-01-01

This study investigated the protein oxidation properties of lamb following chilled-then-frozen storage. Experimental (n=360) M. longissimus lumborum (LL) were randomly sampled from the boning room of a commercial Australian abattoir, at 24h post mortem, and assigned to five chilled storage periods (0, 2, 4, 6 and 8weeks) and six subsequent frozen storage periods (0, 4, 8, 12, 24 and 52weeks). Upon completion of each storage treatment combination, corresponding LL were sub-sectioned and analysed for carbonyl content, protein solubility, nitrate/nitrite content, particle size analysis and estimated myoglobin fractions. The association between these protein measures and shear force was also explored. During chilled storage, particle size and sarcoplasmic protein solubility decreased which indicated protein degradation, while frozen storage only affected myoglobin oxidation. Tenderness was best explained by decreased particle size, decreased deoxymyoglobin and increased oxymyoglobin. No carbonyl effects were observed. It can be concluded that, according to these analyses, that in chilled-then-frozen lamb carbonyl formation was negligible. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Development and evaluation of a digital dental modeling method based on grating projection and reverse engineering software.

PubMed

Zhou, Qin; Wang, Zhenzhen; Chen, Jun; Song, Jun; Chen, Lu; Lu, Yi

2016-01-01

For reasons of convenience and economy, attempts have been made to transform traditional dental gypsum casts into 3-dimensional (3D) digital casts. Different scanning devices have been developed to generate digital casts; however, each has its own limitations and disadvantages. The purpose of this study was to develop an advanced method for the 3D reproduction of dental casts by using a high-speed grating projection system and noncontact reverse engineering (RE) software and to evaluate the accuracy of the method. The methods consisted of 3 main steps: the scanning and acquisition of 3D dental cast data with a high-resolution grating projection system, the reconstruction and measurement of digital casts with RE software, and the evaluation of the accuracy of this method using 20 dental gypsum casts. The common anatomic landmarks were measured directly on the gypsum casts with a Vernier caliper and on the 3D digital casts with the Geomagic software measurement tool. Data were statistically assessed with the t test. The grating projection system had a rapid scanning speed, and smooth 3D dental casts were obtained. The mean differences between the gypsum and 3D measurements were approximately 0.05 mm, and no statistically significant differences were found between the 2 methods (P>.05), except for the measurements of the incisor tooth width and maxillary arch length. A method for the 3D reconstruction of dental casts was developed by using a grating projection system and RE software. The accuracy of the casts generated using the grating projection system was comparable with that of the gypsum casts. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Preliminary science report on the directional solidification of hypereutectic cast iron during KC-135 low-G maneuvers

NASA Technical Reports Server (NTRS)

Curreri, P. A.; Stefanescu, D. M.; Hendrix, J. C.

1983-01-01

An ADSS-P directional solidification furnace was reconfigured for operation on the KC-135 low-g aircraft. The system offers many advantages over quench ingot methods for study of the effects of sedimentation and convection on alloy formation. The directional sodification furnace system was first flown during the September 1982 series of flights. The microstructure of the hypereutectic cast iron sample solidified on one of these flights suggests a low-g effect on graphite morphology. Further experiments are needed to ascertain that this effect is due to low-gravity and to deduce which of the possible mechanisms is responsible for it.

Lower limb intracast pressures generated by different types of immobilisation casts.

PubMed

Chaudhury, Salma; Hazlerigg, Alexandra; Vusirikala, Anuhya; Nguyen, Joseph; Matthews, Stuart

2017-02-18

To determine if complete, split casts and backslabs [plaster of Paris (POP) and fiberglass] generate different intracast pressures and pain. Increased swelling within casts was modeled by a closed water system attached to an expandable bag placed directly under different types of casts applied to a healthy lower limb. Complete fiberglass and POP casts, split casts and backslabs were applied. Twenty-five milliliter aliquots of saline were injected into the system and the generated intracast pressures were measured using a sphygmomanometer. The subject was blinded to the pressure scores to avoid bias. All casts were applied to the same right limb on the same subject to avoid the effects of variations in anatomy or physiology on intracast pressures. Pain levels were evaluated using the Visual Analogue Score after each sequential saline injection. Each type of cast was reapplied four times and the measurements were repeated on four separate occasions. Sample sizes were determined by a pre-study 90% power calculation to detect a 20% difference in intracast pressures between cast groups. A significant difference between the various types of casts was noted when the saline volume was greater than 100 mL ( P = 0.009). The greatest intracast pressure was generated by complete fiberglass casts, which were significantly higher than complete POP casts or backslabs ( P = 0.018 and P = 0.008 respectively) at intracast saline volumes of 100 mL and higher. Backslabs produced a significantly lower intracast pressure compared to complete POP only once the saline volume within casts exceeded 225 mL ( P = 0.009). Intracast pressures were significantly lower in split casts ( P = 0.003). Split POP and fiberglass casts produced the lowest intracast pressures, even compared to backslabs ( P = 0.009). Complete fiberglass casts generated the highest pain levels at manometer pressures of 75 mmHg and greater ( P = 0.001). Split fiberglass casts had significantly reduced pain levels ( P = 0.001). In contrast, a split complete POP cast did not produce significantly reduced pain levels at pressures between 25-150 mmHg. There was no difference in pain generated by complete POP and backslabs at manometer pressures of 200 mmHg and lower. Fibreglass casts generate significantly higher intracast pressures and pain than POP casts. Split casts cause lower intracast pressures regardless of material, than complete casts and backslabs.

Riser Feeding Evaluation Method for Metal Castings Using Numerical Analysis

NASA Astrophysics Data System (ADS)

Ahmad, Nadiah

One of the design aspects that continues to create a challenge for casting designers is the optimum design of casting feeders (risers). As liquid metal solidifies, the metal shrinks and forms cavities inside the casting. In order to avoid shrinkage cavities, risers are added to the casting shape to supply additional molten metal when shrinkage occurs during solidification. The shrinkage cavities in the casting are compensated by controlling the cooling rate to promote directional solidification. This control can be achieved by designing the casting such that the cooling begins at the sections that are farthest away from the risers and ends at the risers. Therefore, the risers will solidify last and feed the casting with the molten metal. As a result, the shrinkage cavities formed during solidification are in the risers which are later removed from the casting. Since casting designers have to usually go through iterative processes of validating the casting designs which are very costly due to expensive simulation processes or manual trials and errors on actual casting processes, this study investigates more efficient methods that will help casting designers utilize their casting experiences systematically to develop good initial casting designs. The objective is to reduce the casting design method iterations; therefore, reducing the cost involved in that design processes. The aim of this research aims at finding a method that can help casting designers design effective risers used in sand casting process of aluminum-silicon alloys by utilizing the analysis of solidification simulation. The analysis focuses on studying the significance of pressure distribution of the liquid metal at the early stage of casting solidification, when heat transfer and convective fluid flow are taken into account in the solidification simulation. The mathematical model of casting solidification was solved using the finite volume method (FVM). This study focuses to improve our understanding of the feeding behavior in aluminum-silicon alloys and the effective feeding by considering the pressure gradient distribution of the molten metal at casting dendrite coherency point. For this study, we will identify the relationship between feeding efficiency, shrinkage behavior and how the change in riser size affects the pressure gradient in the casting. This understanding will be used to help in the design of effective risers.

40 CFR 471.22 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Ammonia 9.95 4.37 Fluoride 4.44 1.97 (b) Forging spent lubricants—subpart B—BAT. There shall be no...-pounds) of forged magnesium cooled with water Chromium 0.127 0.052 Zinc 0.422 0.177 Ammonia 38.5 17.0... forged Chromium 0.002 0.0007 Zinc 0.006 0.003 Ammonia 0.532 0.234 Fluoride 0.238 0.106 (e) Direct chill...

40 CFR 471.22 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Ammonia 9.95 4.37 Fluoride 4.44 1.97 (b) Forging spent lubricants—Subpart B—BAT. There shall be no...-pounds) of forged magnesium cooled with water Chromium 0.127 0.052 Zinc 0.422 0.177 Ammonia 38.5 17.0... forged Chromium 0.002 0.0007 Zinc 0.006 0.003 Ammonia 0.532 0.234 Fluoride 0.238 0.106 (e) Direct chill...

Evaluation of Columbia, USMARC-Composite, Suffolk and Texel rams as terminal sires in an extensive rangeland production system: VII. Accuracy of ultrasound predictors and their association with carcass weight, yield and value

USDA-ARS?s Scientific Manuscript database

Use of lamb body or chilled carcass weights; live-animal ultrasound or direct carcass measurements of backfat thickness (BF; mm) and LM area (LMA; cm2); and carcass body wall thickness (BWall; mm) to predict carcass yield and value was evaluated using 512 crossbred lambs produced over 3 yr by mating...

Mold Flux Crystallization and Mold Thermal Behavior

NASA Astrophysics Data System (ADS)

Peterson, Elizabeth Irene

Mold flux plays a small but critical role in the continuous casting of steel. The carbon-coated powder is added at the top of the water-cooled copper mold, over time it melts and infiltrates the gap between the copper mold and the solidifying steel strand. Mold powders serve five primary functions: (1) chemical insulation, (2) thermal insulation, (3) lubrication between the steel strand and mold, (4) absorption of inclusions, and (5) promotion of even heat flux. All five functions are critical to slab casting, but surface defect prevention is primarily controlled through even heat flux. Glassy fluxes have high heat transfer and result in a thicker steel shell. Steels with large volumetric shrinkage on cooling must have a crystalline flux to reduce the radiative heat transfer and avoid the formation of cracks in the shell. Crystallinity plays a critical role in steel shell formation, therefore it is important to study the thermal conditions that promote each phase and its morphology. Laboratory tests were performed to generate continuous cooling transformation (CCT) and time-temperature-transformation (TTT) diagrams. Continuous cooling transformation tests were performed in an instrumented eight cell step chill mold. Results showed that cuspidine was the only phase formed in conventional fluxes and all observed structures were dendritic. An isothermal tin bath quench method was also developed to isothermally age glassy samples. Isothermal tests yielded different microstructures and different phases than those observed by continuous cooling. Comparison of aged tests with industrial flux films indicates similar faceted structures along the mold wall, suggesting that mold flux first solidifies as a glass along the mold wall, but the elevated temperature devitrifies the glassy structure forming crystals that cannot form by continuous cooling.

40 CFR Table 8 to Subpart Wwww of... - Initial Compliance With Organic HAP Emissions Limits

Code of Federal Regulations, 2014 CFR

2014-07-01

.... open molding and centrifugal casting operations a. an organic HAP emissions limit shown in Tables 3 or... method meet the appropriate organic HAP contents. 2. open molding centrifugal casting, continuous... reduction is being claimed, are using direct die injection, and/or wet-area enclosures that meet the...

40 CFR Table 8 to Subpart Wwww of... - Initial Compliance With Organic HAP Emissions Limits

Code of Federal Regulations, 2013 CFR

2013-07-01

.... open molding and centrifugal casting operations a. an organic HAP emissions limit shown in Tables 3 or... method meet the appropriate organic HAP contents. 2. open molding centrifugal casting, continuous... reduction is being claimed, are using direct die injection, and/or wet-area enclosures that meet the...

40 CFR Table 8 to Subpart Wwww of... - Initial Compliance With Organic HAP Emissions Limits

Code of Federal Regulations, 2012 CFR

2012-07-01

.... open molding and centrifugal casting operations a. an organic HAP emissions limit shown in Tables 3 or... method meet the appropriate organic HAP contents. 2. open molding centrifugal casting, continuous... reduction is being claimed, are using direct die injection, and/or wet-area enclosures that meet the...

New insights on plant phenological response to temperature revealed from long-term widespread observations in China.

PubMed

Zhang, Haicheng; Liu, Shuguang; Regnier, Pierre; Yuan, Wenping

2018-05-01

Constraints of temperature on spring plant phenology are closely related to plant growth, vegetation dynamics, and ecosystem carbon cycle. However, the effects of temperature on leaf onset, especially for winter chilling, are still not well understood. Using long-term, widespread in situ phenology observations collected over China for multiple plant species, this study analyzes the quantitative response of leaf onset to temperature, and compares empirical findings with existing theories and modeling approaches, as implemented in 18 phenology algorithms. Results show that the growing degree days (GDD) required for leaf onset vary distinctly among plant species and geographical locations as well as at organizational levels (species and community), pointing to diverse adaptation strategies. Chilling durations (CHD) needed for releasing bud dormancy decline monotonously from cold to warm areas with very limited interspecies variations. Results also reveal that winter chilling is a crucial component of phenology models, and its effect is better captured with an index that accounts for the inhomogeneous effectiveness of low temperature to chilling rate than with the conventional CHD index. The impact of spring warming on leaf onset is nonlinear, better represented by a logistical function of temperature than by the linear function currently implemented in biosphere models. The optimized base temperatures for thermal accumulation and the optimal chilling temperatures are species-dependent and average at 6.9 and 0.2°C, respectively. Overall, plants' chilling requirement is not a constant, and more chilling generally results in less requirement of thermal accumulation for leaf onset. Our results clearly demonstrate multiple deficiencies of the parameters (e.g., base temperature) and algorithms (e.g., method for calculating GDD) in conventional phenology models to represent leaf onset. Therefore, this study not only advances our mechanistic and quantitative understanding of temperature controls on leaf onset but also provides critical information for improving existing phenology models. © 2017 John Wiley & Sons Ltd.

Transcriptome, carbohydrate, and phytohormone analysis of Petunia hybrida reveals a complex disturbance of plant functional integrity under mild chilling stress

PubMed Central

Bauerfeind, Martin Andreas; Winkelmann, Traud; Franken, Philipp; Druege, Uwe

2015-01-01

Cultivation of chilling-tolerant ornamental crops at lower temperature could reduce the energy demands of heated greenhouses. To provide a better understanding of how sub-optimal temperatures (12°C vs. 16°C) affect growth of the sensitive Petunia hybrida cultivar ‘SweetSunshine Williams’, the transcriptome, carbohydrate metabolism, and phytohormone homeostasis were monitored in aerial plant parts over 4 weeks by use of a microarray, enzymatic assays and GC-MS/MS. The data revealed three consecutive phases of chilling response. The first days were marked by a strong accumulation of sugars, particularly in source leaves, preferential up-regulation of genes in the same tissue and down-regulation of several genes in the shoot apex, especially those involved in the abiotic stress response. The midterm phase featured a partial normalization of carbohydrate levels and gene expression. After 3 weeks of chilling exposure, a new stabilized balance was established. Reduced hexose levels in the shoot apex, reduced ratios of sugar levels between the apex and source leaves and a higher apical sucrose/hexose ratio, associated with decreased activity and expression of cell wall invertase, indicate that prolonged chilling induced sugar accumulation in source leaves at the expense of reduced sugar transport to and reduced sucrose utilization in the shoot. This was associated with reduced levels of indole-3-acetic acid and abscisic acid in the apex and high numbers of differentially, particularly up-regulated genes, especially in the source leaves, including those regulating histones, ethylene action, transcription factors, and a jasmonate-ZIM-domain protein. Transcripts of one Jumonji C domain containing protein and one expansin accumulated in source leaves throughout the chilling period. The results reveal a dynamic and complex disturbance of plant function in response to mild chilling, opening new perspectives for the comparative analysis of differently tolerant cultivars. PMID:26284099

Transcriptome, carbohydrate, and phytohormone analysis of Petunia hybrida reveals a complex disturbance of plant functional integrity under mild chilling stress.

PubMed

Bauerfeind, Martin Andreas; Winkelmann, Traud; Franken, Philipp; Druege, Uwe

2015-01-01

Cultivation of chilling-tolerant ornamental crops at lower temperature could reduce the energy demands of heated greenhouses. To provide a better understanding of how sub-optimal temperatures (12°C vs. 16°C) affect growth of the sensitive Petunia hybrida cultivar 'SweetSunshine Williams', the transcriptome, carbohydrate metabolism, and phytohormone homeostasis were monitored in aerial plant parts over 4 weeks by use of a microarray, enzymatic assays and GC-MS/MS. The data revealed three consecutive phases of chilling response. The first days were marked by a strong accumulation of sugars, particularly in source leaves, preferential up-regulation of genes in the same tissue and down-regulation of several genes in the shoot apex, especially those involved in the abiotic stress response. The midterm phase featured a partial normalization of carbohydrate levels and gene expression. After 3 weeks of chilling exposure, a new stabilized balance was established. Reduced hexose levels in the shoot apex, reduced ratios of sugar levels between the apex and source leaves and a higher apical sucrose/hexose ratio, associated with decreased activity and expression of cell wall invertase, indicate that prolonged chilling induced sugar accumulation in source leaves at the expense of reduced sugar transport to and reduced sucrose utilization in the shoot. This was associated with reduced levels of indole-3-acetic acid and abscisic acid in the apex and high numbers of differentially, particularly up-regulated genes, especially in the source leaves, including those regulating histones, ethylene action, transcription factors, and a jasmonate-ZIM-domain protein. Transcripts of one Jumonji C domain containing protein and one expansin accumulated in source leaves throughout the chilling period. The results reveal a dynamic and complex disturbance of plant function in response to mild chilling, opening new perspectives for the comparative analysis of differently tolerant cultivars.

A cost/utility analysis of open reduction and internal fixation versus cast immobilization for acute nondisplaced mid-waist scaphoid fractures.

PubMed

Davis, Erika N; Chung, Kevin C; Kotsis, Sandra V; Lau, Frank H; Vijan, Sandeep

2006-04-01

Open reduction and internal fixation and cast immobilization are both acceptable treatment options for nondisplaced waist fractures of the scaphoid. The authors conducted a cost/utility analysis to weigh open reduction and internal fixation against cast immobilization in the treatment of acute nondisplaced mid-waist scaphoid fractures. The authors used a decision-analytic model to calculate the outcomes and costs of open reduction and internal fixation and cast immobilization, assuming the societal perspective. Utilities were assessed from 50 randomly selected medical students using the time trade-off method. Outcome probabilities taken from the literature were factored into the calculation of quality-adjusted life-years associated with each treatment. The authors estimated medical costs using Medicare reimbursement rates, and costs of lost productivity were estimated by average wages obtained from the U.S. Bureau of Labor Statistics. Open reduction and internal fixation offers greater quality-adjusted life-years compared with casting, with an increase ranging from 0.21 quality-adjusted life-years for the 25- to 34-year age group to 0.04 quality-adjusted life-years for the > or =65-year age group. Open reduction and internal fixation is less costly than casting ($7940 versus $13,851 per patient) because of a longer period of lost productivity with casting. Open reduction and internal fixation is therefore the dominant strategy. When considering only direct costs, the incremental cost/utility ratio for open reduction and internal fixation ranges from $5438 per quality-adjusted life-year for the 25- to 34-year age group to $11,420 for the 55- to 64-year age group, and $29,850 for the > or =65-year age group. Compared with casting, open reduction and internal fixation is cost saving from the societal perspective ($5911 less per patient). When considering only direct costs, open reduction and internal fixation is cost-effective relative to other widely accepted interventions.

76 FR 22422 - Determinations to Conduct Full Five-Year Reviews Concerning the Countervailing Duty and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-21

...; Fresh and Chilled Atlantic Salmon From Norway AGENCY: United States International Trade Commission... revocation of the countervailing duty and antidumping duty orders on fresh and chilled Atlantic salmon from...

A novel aspartic acid protease gene from pineapple fruit (Ananas comosus): cloning, characterization and relation to postharvest chilling stress resistance.

PubMed

Raimbault, Astrid-Kim; Zuily-Fodil, Yasmine; Soler, Alain; Cruz de Carvalho, Maria H

2013-11-15

A full-length cDNA encoding a putative aspartic acid protease (AcAP1) was isolated for the first time from the flesh of pineapple (Ananas comosus) fruit. The deduced sequence of AcAP1 showed all the common features of a typical plant aspartic protease phytepsin precursor. Analysis of AcAP1 gene expression under postharvest chilling treatment in two pineapple varieties differing in their resistance to blackheart development revealed opposite trends. The resistant variety showed an up-regulation of AcAP1 precursor gene expression whereas the susceptible showed a down-regulation in response to postharvest chilling treatment. The same trend was observed regarding specific AP enzyme activity in both varieties. Taken together our results support the involvement of AcAP1 in postharvest chilling stress resistance in pineapple fruits. Copyright © 2013 Elsevier GmbH. All rights reserved.

Winter fog is decreasing in the fruit growing region of the Central Valley of California

NASA Astrophysics Data System (ADS)

Baldocchi, Dennis; Waller, Eric

2014-05-01

The Central Valley of California is home to a variety of fruit and nut trees. These trees account for 95% of the U.S. production, but they need a sufficient amount of winter chill to achieve rest and quiescence for the next season's buds and flowers. In prior work, we reported that the accumulation of winter chill is declining in the Central Valley. We hypothesize that a reduction in winter fog is cooccurring and is contributing to the reduction in winter chill. We examined a 33 year record of satellite remote sensing to develop a fog climatology for the Central Valley. We find that the number of winter fog events, integrated spatially, decreased 46%, on average, over 32 winters, with much year to year variability. Less fog means warmer air and an increase in the energy balance on buds, which amplifies their warming, reducing their chill accumulation more.

Triple Plate Mold Final Report: Optimization of the Mold Design and Casting Parameters for a Thin U-10mo Fuel Casting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aikin, Jr., Robert M.

This work describes the experiments and modeling that have been performed to improve and try to optimize the simultaneous casting of three plates of U-10wt%Mo in a single coil vacuum induction melting (VIM) furnace. The plates of interest are 280 mm wide by 203 mm tall by 5 mm thick (11" x 8" x 0.2"). The initial mold design and processing parameters were supplied by Y-12. The mold and casting cavity were instrumented with a number of thermocouples, and the casting performed to determine the thermal history of the mold and casting. The resulting cast plates were radiographed and numerousmore » defects identified. Metallography was performed to help identify the nature of the radiographically observed defects. This information was then used to validate a mold filling and solidification model of that casting. Based on the initial casting, good casting design practice, and process simulation of several design alternatives, a revised design was developed with the goal of minimizing casting defects such as porosity. The redesigned mold had a larger hot-top and had its long axis along the horizontal direction. These changes were to try to develop a strong thermal gradient conducive to good feeding and minimization of micro- and macroporosity in the cast plates. An instrumented casting was then performed with the revised mold design and a linear distributor. This design yielded cast plates with significantly less radiographically identified defects. Unfortunately, there was significant variation in plate weight and metal content in their hot-tops. Fluid flow simulations were then performed on this mold/distributor design. This helped identify the issue with this linear distributor design. Additional simulations were then performed on candidate distributor redesigns and a preferred distributor annular design was identified. This improved annular design was used to produce a third instrumented casting with favorable results. These refined designs and their radiographic characterization are compared to the initial design.« less

Relationship between aerobic bacteria, salmonellae and Campylobacter on broiler carcasses.

PubMed

Cason, J A; Bailey, J S; Stern, N J; Whittemore, A D; Cox, N A

1997-07-01

Broiler carcasses were removed from commercial processing lines immediately after defeathering, before chilling, and after chilling to determine whether any relationship exists between aerobic bacteria and the human enteropathogens salmonellae and Campylobacter. In two experiments, a whole carcass rinse procedure was used to sample 30 carcasses after defeathering, 90 carcasses before chilling, and 90 carcasses after chilling, for a total of 210 different carcasses. Aerobic bacteria and Campylobacter spp. were enumerated and the incidence of salmonellae was determined. Salmonellae and Campylobacter incidences were 20 and 94%, respectively, for all carcasses sampled. After picking, neither salmonellae-positive nor Campylobacter-positive carcasses had mean aerobic most probable number (MPN) values that were different from carcasses negative for those organisms. Immediately before chilling, aerobic and Campylobacter counts were 7.12 and 5.33 log10 cfu per carcass, respectively. Immersion chilling reduced aerobic counts by approximately 1.8 log and Campylobacter by 1.5 log, with no change in salmonellae-positive carcasses. There was no difference in aerobic or Campylobacter counts between carcasses that were positive or negative for salmonellae at any of the sampling locations, nor was any correlation found between levels of aerobic organisms and Campylobacter. Carcasses with aerobic counts above the mean or more than one standard deviation above the mean also failed to show any correlation. Discriminant analysis indicated error rates as high as 50% when numbers of aerobic bacteria were used to predict incidence of salmonellae or Campylobacter on individual carcasses. Aerobic bacteria are not suitable as index organisms for salmonellae or Campylobacter on broiler carcasses.

Coupling of Physiological and Proteomic Analysis to Understand the Ethylene- and Chilling-Induced Kiwifruit Ripening Syndrome

PubMed Central

Minas, Ioannis S.; Tanou, Georgia; Karagiannis, Evangelos; Belghazi, Maya; Molassiotis, Athanassios

2016-01-01

Kiwifruit [Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson, cv. “Hayward”] is classified as climacteric fruit and the initiation of endogenous ethylene production following harvest is induced by exogenous ethylene or chilling exposure. To understand the biological basis of this “dilemma,” kiwifruit ripening responses were characterized at 20°C following treatments with exogenous ethylene (100 μL L−1, 20°C, 24 h) or/and chilling temperature (0°C, 10 days). All treatments elicited kiwifruit ripening and induced softening and endogenous ethylene biosynthesis, as determined by 1-aminocyclopropane-1-carboxylic acid (ACC) content and ACC synthase (ACS) and ACC oxidase (ACO) enzyme activities after 10 days of ripening at 20°C. Comparative proteomic analysis using two-dimensional gel electrophoresis (2DE-PAGE) and nanoscale liquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS) revealed 81 kiwifruit proteins associated with ripening. Thirty-one kiwifruit proteins were identified as commonly regulated by the three treatments accompanied by dynamic changes of 10 proteins specific to exogenous ethylene, 2 to chilling treatment, and 12 to their combination. Ethylene and/or chilling-responsive proteins were mainly involved in disease/defense, energy, protein destination/storage, and cell structure/cell wall. Interactions between the identified proteins were demonstrated by bioinformatics analysis, allowing a more complete insight into biological pathways and molecular functions affected by ripening. The present approach provides a quantitative basis for understanding the ethylene- and chilling-induced kiwifruit ripening and climacteric fruit ripening in general. PMID:26913040

Data on the effect of homogenization heat treatments on the cast structure and tensile properties of alloy 718Plus in the presence of grain-boundary elements.

PubMed

Hosseini, Seyed Ali; Madar, Karim Zangeneh; Abbasi, Seyed Mehdi

2017-08-01

The segregation of the elements during solidification and the direct formation of destructive phases such as Laves from the liquid, result in in-homogeneity of the cast structure and degradation of mechanical properties. Homogenization heat treatment is one of the ways to eliminate destructive Laves from the cast structure of superalloys such as 718Plus. The collected data presents the effect of homogenization treatment conditions on the cast structure, hardness, and tensile properties of the alloy 718Plus in the presence of boron and zirconium additives. For this purpose, five alloys with different contents of boron and zirconium were cast by VIM/VAR process and then were homogenized at various conditions. The microstructural investigation by OM and SEM and phase analysis by XRD were done and then hardness and tensile tests were performed on the homogenized alloys.

Fuzzy control strategy for secondary cooling of continuous steel casting

NASA Astrophysics Data System (ADS)

Tirian, G. O.; Gheorghiu, C. A.; Hepuţ, T.; Rob, R.

2017-05-01

The purpose of this paper is to create an original fuzzy solution on the existing structure of the control system of continuous casting that eliminates fissures in the poured material from the secondary cooling of steel. For this purpose a system was conceived with three fuzzy database decision rules, which by analyzing a series of measurements taken from the process produces adjustments in the rate of flow of the cooling water and the speed of casting and determine the degree of risk of the wire. In the specialized literature on the national plan and the world, there is no intelligent correction in the rate of flow of the cooling water and the speed of casting in the secondary cooling of steel. The database of rules was made using information collected directly from the installation process of continuous casting of the Arcelor Mittal Hunedoara.

Manufacturing technology methodology for propulsion system parts

NASA Astrophysics Data System (ADS)

McRae, M. M.

1992-07-01

A development history and a current status evaluation are presented for lost-wax casting of such gas turbine engine components as turbine vanes and blades. The most advanced such systems employ computer-integrated manufacturing methods for high process repeatability, reprogramming versatility, and feedback monitoring. Stereolithography-based plastic model 3D prototyping has also been incorporated for the wax part of the investment casting; it may ultimately be possible to produce the 3D prototype in wax directly, or even to create a ceramic mold directly. Nonintrusive inspections are conducted by X-radiography and neutron radiography.

Chilled storage of foods - principles

USDA-ARS?s Scientific Manuscript database

Chilled storage is the most common method for preserving perishable foods. The consumers’ increasing demand for convenient, minimally processed foods has caused food manufacturers to increase production of refrigerated foods worldwide. This book chapter reviews the development of using low tempera...

Can the exceptional chilling tolerance of C4 photosynthesis found in Miscanthus × giganteus be exceeded? Screening of a novel Miscanthus Japanese germplasm collection.

PubMed

Głowacka, Katarzyna; Jørgensen, Uffe; Kjeldsen, Jens B; Kørup, Kirsten; Spitz, Idan; Sacks, Erik J; Long, Stephen P

2015-05-01

A clone of the hybrid perennial C4 grass Miscanthus × giganteus (Mxg) is known for achieving exceptionally high rates of leaf CO2 uptake during chilling. This is a requisite of success in the early spring, as is the ability of the leaves to survive occasional frosts. The aim of this study was to search for genotypes with greater potential than Mxg for photosynthesis and frost survival under these conditions. A total of 864 accessions representing 164 local populations of M. sacchariflorus (Msa), M. sinensis (Msi) and M. tinctorius (Mti) collected across Japan were studied. Accessions whose leaves survived a natural late frost in the field were screened for high maximum photosystem II efficiency (Fv/Fm) following chilling weather, as an indicator of their capacity for light-limited photosynthesis. Those showing the highest Fv/Fm were transferred to a high-light-controlled environment and maintained at chilling temperatures, where they were further screened for their capacities for high-light-limited and light-saturated leaf uptake of CO2 (ΦCO2,max and Asat, respectively). For the first time, relatives of Mxg with significantly superior capacities for photosynthesis at chilling temperatures were identified. Msa accession '73/2' developed leaves in the spring that survived night-time frost, and during growth under chilling maintained a statistically significant 79 % higher ΦCO2,max, as a measure of light-limited photosynthesis, and a 70 % higher Asat, as a measure of light-saturated photosynthesis. A second Msa accession, '73/3' also showed significantly higher rates of leaf uptake of CO2. As remarkable as Mxg has proved in its chilling tolerance of C4 photosynthesis, this study shows that there is still value and potential in searching for yet more superior tolerance. Msa accession '73/2' shows rates of light-limited and light-saturated photosynthesis at chilling temperatures that are comparable with those of the most cold-tolerant C3 species. This adds further proof to the thesis that C4 photosynthesis is not inherently limited to warm climates. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Interaction of Polyamines, Abscisic Acid, Nitric Oxide, and Hydrogen Peroxide under Chilling Stress in Tomato (Lycopersicon esculentum Mill.) Seedlings.

PubMed

Diao, Qiannan; Song, Yongjun; Shi, Dongmei; Qi, Hongyan

2017-01-01

Polyamines (PAs) play a vital role in the responses of higher plants to abiotic stresses. However, only a limited number of studies have examined the interplay between PAs and signal molecules. The aim of this study was to elucidate the cross-talk among PAs, abscisic acid (ABA), nitric oxide (NO), and hydrogen peroxide (H 2 O 2 ) under chilling stress conditions using tomato seedlings [( Lycopersicon esculentum Mill.) cv. Moneymaker]. The study showed that during chilling stress (4°C; 0, 12, and 24 h), the application of spermidine (Spd) and spermine (Spm) elevated NO and H 2 O 2 levels, enhanced nitrite reductase (NR), nitric oxide synthase (NOS)-like, and polyamine oxidase activities, and upregulated LeNR relative expression, but did not influence LeNOS1 expression. In contrast, putrescine (Put) treatment had no obvious impact. During the recovery period (25/15°C, 10 h), the above-mentioned parameters induced by the application of PAs were restored to their control levels. Seedlings pretreated with sodium nitroprusside (SNP, an NO donor) showed elevated Put and Spd levels throughout the treatment period, consistent with increased expression in leaves of genes encoding arginine decarboxylase ( LeADC. LeADC1 ), ornithine decarboxylase ( LeODC ), and Spd synthase ( LeSPDS ) expressions in tomato leaves throughout the treatment period. Under chilling stress, the Put content increased first, followed by a rise in the Spd content. Exogenously applied SNP did not increase the expression of genes encoding S -adenosylmethionine decarboxylase ( LeSAMDC ) and Spm synthase ( LeSPMS ), consistent with the observation that Spm levels remained constant under chilling stress and during the recovery period. In contrast, exogenous Put significantly increased the ABA content and the 9- cis -epoxycarotenoid dioxygenase ( LeNCED1 ) transcript level. Treatment with ABA could alleviate the electrolyte leakage (EL) induced by D-Arg (an inhibitor of Put). Taken together, it is concluded that, under chilling stress, Spd and Spm enhanced the production of NO in tomato seedlings through an H 2 O 2 -dependent mechanism, via the NR and NOS-like pathways. ABA is involved in Put-induced tolerance to chilling stress, and NO could increase the content of Put and Spd under chilling stress.

Interaction of Polyamines, Abscisic Acid, Nitric Oxide, and Hydrogen Peroxide under Chilling Stress in Tomato (Lycopersicon esculentum Mill.) Seedlings

PubMed Central

Diao, Qiannan; Song, Yongjun; Shi, Dongmei; Qi, Hongyan

2017-01-01

Polyamines (PAs) play a vital role in the responses of higher plants to abiotic stresses. However, only a limited number of studies have examined the interplay between PAs and signal molecules. The aim of this study was to elucidate the cross-talk among PAs, abscisic acid (ABA), nitric oxide (NO), and hydrogen peroxide (H2O2) under chilling stress conditions using tomato seedlings [(Lycopersicon esculentum Mill.) cv. Moneymaker]. The study showed that during chilling stress (4°C; 0, 12, and 24 h), the application of spermidine (Spd) and spermine (Spm) elevated NO and H2O2 levels, enhanced nitrite reductase (NR), nitric oxide synthase (NOS)-like, and polyamine oxidase activities, and upregulated LeNR relative expression, but did not influence LeNOS1 expression. In contrast, putrescine (Put) treatment had no obvious impact. During the recovery period (25/15°C, 10 h), the above-mentioned parameters induced by the application of PAs were restored to their control levels. Seedlings pretreated with sodium nitroprusside (SNP, an NO donor) showed elevated Put and Spd levels throughout the treatment period, consistent with increased expression in leaves of genes encoding arginine decarboxylase (LeADC. LeADC1), ornithine decarboxylase (LeODC), and Spd synthase (LeSPDS) expressions in tomato leaves throughout the treatment period. Under chilling stress, the Put content increased first, followed by a rise in the Spd content. Exogenously applied SNP did not increase the expression of genes encoding S-adenosylmethionine decarboxylase (LeSAMDC) and Spm synthase (LeSPMS), consistent with the observation that Spm levels remained constant under chilling stress and during the recovery period. In contrast, exogenous Put significantly increased the ABA content and the 9-cis-epoxycarotenoid dioxygenase (LeNCED1) transcript level. Treatment with ABA could alleviate the electrolyte leakage (EL) induced by D-Arg (an inhibitor of Put). Taken together, it is concluded that, under chilling stress, Spd and Spm enhanced the production of NO in tomato seedlings through an H2O2-dependent mechanism, via the NR and NOS-like pathways. ABA is involved in Put-induced tolerance to chilling stress, and NO could increase the content of Put and Spd under chilling stress. PMID:28261254

Directional migration in the Hindu castes: inferences from mitochondrial, autosomal and Y-chromosomal data.

PubMed

Wooding, Stephen; Ostler, Christopher; Prasad, B V Ravi; Watkins, W Scott; Sung, Sandy; Bamshad, Mike; Jorde, Lynn B

2004-08-01

Genetic, ethnographic, and historical evidence suggests that the Hindu castes have been highly endogamous for several thousand years and that, when movement between castes does occur, it typically consists of females joining castes of higher social status. However, little is known about migration rates in these populations or the extent to which migration occurs between caste groups of low, middle, and high social status. To investigate these aspects of migration, we analyzed the largest collection of genetic markers collected to date in Hindu caste populations. These data included 45 newly typed autosomal short tandem repeat polymorphisms (STRPs), 411 bp of mitochondrial DNA sequence, and 43 Y-chromosomal single-nucleotide polymorphisms that were assayed in more than 200 individuals of known caste status sampled in Andrah Pradesh, in South India. Application of recently developed likelihood-based analyses to this dataset enabled us to obtain genetically derived estimates of intercaste migration rates. STRPs indicated migration rates of 1-2% per generation between high-, middle-, and low-status caste groups. We also found support for the hypothesis that rates of gene flow differ between maternally and paternally inherited genes. Migration rates were substantially higher in maternally than in paternally inherited markers. In addition, while prevailing patterns of migration involved movement between castes of similar rank, paternally inherited markers in the low-status castes were most likely to move into high-status castes. Our findings support earlier evidence that the caste system has been a significant, long-term source of population structuring in South Indian Hindu populations, and that patterns of migration differ between males and females. Copyright 2004 Springer-Verlag

Cyp15F1: a novel cytochrome P450 gene linked to juvenile hormone-dependent caste differention in the termite Reticulitermes flavipes.

PubMed

Tarver, Matthew R; Coy, Monique R; Scharf, Michael E

2012-07-01

Termites are eusocial insects that jointly utilize juvenile hormone (JH), pheromones, and other semiochemicals to regulate caste differentiation and achieve caste homeostasis. Prior EST sequencing from the symbiont-free gut transcriptome of Reticulitermes flavipes unexpectedly revealed a number of unique cytochrome P450 (Cyp) transcripts, including fragments of a Cyp15 family gene (Cyp15F1) with homology to other insect Cyp15s that participate in JH biosynthesis. The present study investigated the role of Cyp15F1 in termite caste polyphenism and specifically tested the hypothesis that it plays a role in JH-dependent caste differentiation. After assembling the full-length Cyp15F1 cDNA sequence, we (i) determined its mRNA tissue expression profile, (ii) investigated mRNA expression changes in response to JH and the caste-regulatory primer pheromones γ-cadinene (CAD) and γ-cadinenal (ALD), and (iii) used RNA interference (RNAi) in combination with caste differentiation bioassays to investigate gene function at the phenotype level. Cyp15F1 has ubiquitous whole-body expression (including gut tissue); is rapidly and sustainably induced from 3 h to 48 h by JH, CAD, and ALD; and functions at least in part by facilitating JH-dependent soldier caste differentiation. These findings provide the second example of a termite caste regulatory gene identified through the use of RNAi, and significantly build upon our understanding of termite caste homeostatic mechanisms. These results also reinforce the concept of environmental caste determination in termites by revealing how primer pheromones, as socioenvironmental factors, can directly influence Cyp15 expression and caste differentiation. © 2012 Wiley Periodicals, Inc.

Casting evaluation of U-Zr alloy system fuel slug for SFR prepared by injection casting method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Hoon; Kim, Jong-Hwan; Kim, Ki-Hwan

2013-07-01

Metal fuel slugs of U-Pu-Zr alloys for Sodium-cooled Fast Reactor (SFR) have conventionally been fabricated by a vacuum injection casting method. Recently, management of minor actinides (MA) became an important issue because direct disposal of the long-lived MA can be a long-term burden for a tentative repository up to several hundreds of thousand years. In order to recycle transuranic elements (TRU) retained in spent nuclear fuel, remote fabrication capability in a shielded hot cell should be prepared. Moreover, generation of long-lived radioactive wastes and loss of volatile species should be minimized during the recycled fuel fabrication step. In order tomore » prevent the evaporation of volatile elements such as Am, alternative fabrication methods of metal fuel slugs have been studied applying gravity casting, and improved injection casting in KAERI, including melting under inert atmosphere. And then, metal fuel slugs were examined with casting soundness, density, chemical analysis, particle size distribution and microstructural characteristics. Based on these results there is a high level of confidence that Am losses will also be effectively controlled by application of a modest amount of overpressure. A surrogate fuel slug was generally soundly cast by improved injection casting method, melted fuel material under inert atmosphere.« less

Method and apparatus for casting conductive and semi-conductive materials

DOEpatents

Ciszek, T.F.

1984-08-13

A method and apparatus is disclosed for casting conductive and semi-conductive materials. The apparatus includes a plurality of conductive members arranged to define a container-like area having a desired cross-sectional shape. A portion or all of the conductive or semi-conductive material which is to be cast is introduced into the container-like area. A means is provided for inducing the flow of an electrical current in each of the conductive members, which currents act collectively to induce a current flow in the material. The induced current flow through the conductive members is in a direction substantially opposite to the induced current flow in the material so that the material is repelled from the conductive members during the casting process.

Method and apparatus for casting conductive and semiconductive materials

DOEpatents

Ciszek, Theodore F.

1986-01-01

A method and apparatus is disclosed for casting conductive and semiconduce materials. The apparatus includes a plurality of conductive members arranged to define a container-like area having a desired cross-sectional shape. A portion or all of the conductive or semiconductive material which is to be cast is introduced into the container-like area. A means is provided for inducing the flow of an electrical current in each of the conductive members, which currents act collectively to induce a current flow in the material. The induced current flow through the conductive members is in a direction substantially opposite to the induced current flow in the material so that the material is repelled from the conductive members during the casting process.

Parabolic aircraft solidification experiments

NASA Technical Reports Server (NTRS)

Workman, Gary L. (Principal Investigator); Smith, Guy A.; OBrien, Susan

1996-01-01

A number of solidification experiments have been utilized throughout the Materials Processing in Space Program to provide an experimental environment which minimizes variables in solidification experiments. Two techniques of interest are directional solidification and isothermal casting. Because of the wide-spread use of these experimental techniques in space-based research, several MSAD experiments have been manifested for space flight. In addition to the microstructural analysis for interpretation of the experimental results from previous work with parabolic flights, it has become apparent that a better understanding of the phenomena occurring during solidification can be better understood if direct visualization of the solidification interface were possible. Our university has performed in several experimental studies such as this in recent years. The most recent was in visualizing the effect of convective flow phenomena on the KC-135 and prior to that were several successive contracts to perform directional solidification and isothermal casting experiments on the KC-135. Included in this work was the modification and utilization of the Convective Flow Analyzer (CFA), the Aircraft Isothermal Casting Furnace (ICF), and the Three-Zone Directional Solidification Furnace. These studies have contributed heavily to the mission of the Microgravity Science and Applications' Materials Science Program.

Analyses of rail chill effect

DOT National Transportation Integrated Search

1998-06-01

The principles of heat transfer are applied to analyze the so-called "rail chill" effect, which refers to hear loss by conduction from a hot rail vehicle wheel through the contact area into a cold rail, the wheel having been heated by friction brakin...

Enhanced susceptibility of photosynthesis to low-temperature photoinhibition due to interruption of chill-induced increase of S-adenosylmethionine decarboxylase activity in leaves of spinach (Spinacia oleracea L.).

PubMed

He, Lixiong; Nada, Kazuyoshi; Kasukabe, Yoshihisa; Tachibana, Shoji

2002-02-01

The possible involvement of polyamines in the chilling tolerance of spinach (Spinacia oleracea L.) was investigated focusing on photosynthesis. During chilling at 8/5C (day/night) for 6 d, S-adenosylmethionine decarboxylase (SAMDC) activity increased significantly in leaves in parallel with the increase in putrescine and spermidine (Spd) content in leaves and chloroplasts. Treatment of leaves with methylglyoxal-bis(guanylhydrazone) (MGBG), an SAMDC inhibitor, resulted in the deterioration of plant growth and photosynthesis under chilling conditions, which was reversed by the concomitant treatment with Spd through the roots. Plants treated with MGBG showed lower photochemical efficiency of PSII than either the control or plants treated with MGBG plus Spd during chilling and even after transfer to warm conditions, suggesting an increase of photoinhibition due to low Spd in chloroplasts. Indeed, MGBG-treated plants had much lower activities of thylakoid electron transport and enzymes in carbon metabolism as well as higher degrees of lipid peroxidation of thylakoid membranes compared to the control. These results indicate that the enhanced activity of SAMDC with a consequential rise of Spd in chloroplasts is crucial for the cold acclimation of the photosynthetic apparatus in spinach leaves.

Development of a Safety Monitoring and Assurance System for chilled food products.

PubMed

Koutsoumanis, K; Taoukis, P S; Nychas, G J E

2005-04-15

The principles of a novel chill chain management policy, coded Safety Monitoring and Assurance System (SMAS) for the optimisation of the distribution of chilled food products within the chill chain are developed. In this system, a new approach based on actual risk evaluation at important points of the chill chain is used in order to promote products to the next stage of distribution. This evaluation based on product's time-temperature history, variation in product's characteristics (e.g. a(w), pH, etc.), and the use of predictive models for the growth of food pathogens, allows to give priority to products in such a way that risk at consumption time is minimized. The effectiveness of SMAS was evaluated against the First In First Out (FIFO) approach, the current method for food distribution, in a case study on the risk of listeriosis of cooked ham using the Monte Carlo simulation technique. Furthermore, the two approaches were compared for their effect on the quality of the products in terms of remaining shelf life at the time of consumption. The results showed that following the SMAS approach the risk of listerisosis is significantly lower while the spoiled products at the time of consumption are significantly reduced compared to FIFO approach.

Georgia Institute of Technology chilled water system evaluation and master plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-05-15

As the host of the Olympic Village for the 1996 Atlanta Olympics, Georgia Tech has experienced a surge in construction activities over the last three years. Over 1.3 million square feet of new buildings have been constructed on the Georgia Tech campus. This growth has placed a strain on the Georgia Tech community and challenged the facilities support staff charged with planning and organizing utility services. In concert with Olympic construction, utility planners have worked to ensure long term benefits for Georgia Tech facilities while meeting the short term requirements of the Olympic Games. The concentration of building construction inmore » the northwest quadrant of the campus allowed planners to construct a satellite chilled water plant to serve the needs of this area and provide the opportunity to integrate this section of the campus with the main campus chilled water system. This assessment and master plan, funded in part by the US Department of Energy, has evaluated the chilled water infrastructure at Georgia Tech, identified ongoing problems and made recommendations for long term chilled water infrastructure development and efficiency improvements. The Georgia Tech office of Facilities and RDA Engineering, Inc. have worked together to assemble relevant information and prepare the recommendations contained in this document.« less

Research on factors allowing a risk assessment of spore-forming pathogenic bacteria in cooked chilled foods containing vegetables: a FAIR collaborative project.

PubMed

Carlin, F; Girardin, H; Peck, M W; Stringer, S C; Barker, G C; Martinez, A; Fernandez, A; Fernandez, P; Waites, W M; Movahedi, S; van Leusden, F; Nauta, M; Moezelaar, R; Torre, M D; Litman, S

2000-09-25

Vegetables are frequent ingredients of cooked chilled foods and are frequently contaminated with spore-forming bacteria (SFB). Therefore, risk assessment studies have been carried out, including the following: hazard identification and characterisation--from an extensive literature review and expertise of the participants, B. cereus and C. botulinum were identified as the main hazards; exposure assessment--consisting of determination of the prevalence of hazardous SFB in cooked chilled foods containing vegetables and in unprocessed vegetables, and identification of SFB representative of the bacterial community in cooked chilled foods containing vegetables, determination of heat-resistance parameters and factors affecting heat resistance of SFB, determination of the growth kinetics of SFB in vegetable substrate and of the influence of controlling factors, validation of previous work in complex food systems and by challenge testing and information about process and storage conditions of cooked chilled foods containing vegetables. The paper illustrates some original results obtained in the course of the project. The results and information collected from scientific literature or from the expertise of the participants are integrated into the microbial risk assessment, using both a Bayesian belief network approach and a process risk model approach, previously applied to other foodborne hazards.

Adaptation to altitude affects the senescence response to chilling in the perennial plant Arabis alpina

PubMed Central

Wingler, Astrid; Juvany, Marta; Cuthbert, Caroline; Munné-Bosch, Sergi

2015-01-01

In annual plants with determinate growth, sugar accumulation signals high carbon availability once growth has ceased, resulting in senescence-dependent nutrient recycling to the seeds. However, this senescence-inducing effect of sugars is abolished at cold temperature, where sugar accumulation is important for protection. Here, natural variation was exploited to analyse the effect of chilling on interactions between leaf senescence, sugars, and phytohormones in Arabis alpina, a perennial plant with indeterminate growth. Eight accessions of A. alpina originating from between 2090 and 3090 m above sea level in the French Alps were used to identify heritable adaptations in senescence, stress response, sugars, and phytohormones to altitude. Accessions from high altitudes showed an enhanced capacity for sucrose accumulation and a diminished loss of chlorophyll in response to chilling. At warm temperature, sucrose content was negatively correlated with chlorophyll content, and sucrose treatment induced leaf senescence. Chilling resulted in lower indole-3-acetic acid, but higher zeatin and jasmonic acid contents. Interactions between sugar and phytohormones included a positive correlation between sucrose and jasmonic acid contents that may be involved in promoting the stress-dependent decline in chlorophyll. These findings reveal regulatory interactions that underlie adaptation in the senescence and stress response to chilling. PMID:25371506

The involvement of mitochondrial phosphate transporter in accelerating bud dormancy release during chilling treatment of tree peony (Paeonia suffruticosa).

PubMed

Huang, Xin; Zhu, Wei; Dai, Silan; Gai, Shupeng; Zheng, Guosheng; Zheng, Chengchao

2008-09-01

A cDNA clone was isolated from tree peony (Paeonia suffruticosa) subtractive cDNA library of burst buds and characterized with regard to its sequence, expression in response to chilling treatment during the release of bud dormancy, and its function in transgenic Arabidopsis thaliana. The clone, designated as PsMPT, contains 1,615 nucleotides with an open reading frame of 1,119 nucleotides, and the deduced amino acid sequence shows high homology with mitochondrial phosphate transporters (MPTs) from various organisms. The mRNA accumulation of PsMPT in tree peony was strongly induced by chilling treatment during the release of bud dormancy. When the treated plants were transferred to normal growth conditions, the level of PsMPT transcripts induced by sufficient chilling could be maintained high, whereas that induced by insufficient chilling decreased sharply. The transgenic Arabidopsis plants that overexpress PsMPT showed rapid growth and earlier flowering than wild-type plants. ATP contents in the transgenic plants were much higher than that in wild-type plants through various developmental stages. Together, these results suggest that the product of PsMPT is a MPT and might play an important role during the release of bud dormancy in tree peony.

Cold induced changes in the water balance affect immunocytolocalization pattern of one of the aquaporins in the vascular system in the leaves of maize (Zea mays L.).

PubMed

Bilska-Kos, Anna; Szczepanik, Jarosław; Sowiński, Paweł

2016-10-20

Chilling stress is known to affect the water balance in plants, which often manifests itself in the decrease of the water potential in different organs. Relationships between chilling, assimilate transport and water balance are far from being understood. Although aquaporins play a key role in regulating water balance in plants, especially under stress conditions, the role of individual aquaporins in stress response remains unclear. In this report we show the specific localization within plasma membranes of one of the aquaporins (PIP2;3) in the leaves of two maize inbred lines differing in their chilling-sensitivity. This form of aquaporin has been also observed in thick-walled sieve elements - an additional type of sieve tubes of unclear function found only in monocotyledons. Moderate chilling (about 15°C) caused significant reduction of labelling in these cells accompanied by a steep decrease in the water potential in leaves of chilling-sensitive maize line. Our results suggest that both PIP2;3 and thick-walled sieve tubes may be an unknown element of the mechanism of the response of maize to cold stress. Copyright © 2016 Elsevier GmbH. All rights reserved.

The use of phenological data to calculate chilling units in Olea europaea L. in relation to the onset of reproduction

NASA Astrophysics Data System (ADS)

Orlandi, F.; Fornaciari, M.; Romano, B.

2002-02-01

The aim of this study was to develop a practical method to evaluate the effective relationship between the amount of winter chilling and the response expressed as the spring reproductive re-starting dates in the olive ( Olea europaea L.). Two olive cultivars growing in a special olive orchard in Umbria (central Italy) were studied over a 3-year period (1998-2000): the cultivar Ascolana, typical of central Italy, and the cultivar Giarraffa, typical of southern Italy. The spring reproductive re-starts were assessed using data from detailed phenological observations made on 60 trees of each cultivar in an effort to establish the exact date of reproductive bud swelling. The chilling phenomenon was evaluated by using 341 functions derived from a formula developed by researchers at Utah State University to calculate chilling units. The mathematical functions are defined, and show the very close relationship between the amount of winter chilling and the spring reproductive response in the two cultivars in the orchard studied. The results can be used to define the relationship between local climate and plant development, and the mathematical approach can be used to draw maps that can show the suitability of different cultivars on the basis of local climatic conditions.

Effects of hygienic treatments during slaughtering on microbial dynamics and contamination of sheep meat.

PubMed

Omer, Mohamed K; Hauge, Sigrun J; Østensvik, Øyvin; Moen, Birgitte; Alvseike, Ole; Røtterud, Ole-Johan; Prieto, Miguel; Dommersnes, Sissel; Nesteng, Ole H; Nesbakken, Truls

2015-02-02

The aims of this study were to investigate bacterial dynamics in the sheep meat chain, from fleece to meat trimmings, using both quantitative and qualitative analyses, and to study the effects on microbial load associated with the hygienic interventions of: i) shearing sheep immediately before slaughter, ii) manual steam vacuum pasteurisation, iii) hot water pasteurisation of carcasses, followed by iv) chilling. A further aim was to provide evidence to determine whether or not unshorn sheep should be handled in a processing line separate from that of shorn sheep in Norwegian abattoirs. A total of 176 surface swab samples were collected from three sites along the value chain: i) on fleeces, ii) on carcasses at the end of the slaughter line, and iii) on carcasses after chilling for 24h, and 32 samples were collected from meat trimmings. The results showed that Aerobic Plate Counts (APC) were lower for the shorn group compared to the unshorn group, both on carcasses before chilling and after chilling (difference of 0.8 and 0.9logCFU/1000cm(2) (p≤0.05), respectively) and in meat trimmings (difference of 0.5logCFU/g (p≤0.05)). Hygienic treatments were used on carcasses derived from unshorn sheep, and steam vacuum treatment reduced Escherichia coli, Enterobacteriaceae, and APC before chilling by 1.2, 1.0, and 0.6logCFU/1000cm(2) (p≤0.05), respectively, and hot water pasteurisation, in addition to chilling, reduced E. coli, Enterobacteriaceae, and APC by 0.7, 1.0, and 0.9logCFU/1000cm(2) (p≤0.05), respectively, compared with untreated carcasses. The effect of chilling was shown by the significant reduction of number of carcasses where E. coli were detected; from 65% (13/20) of the shorn group before chilling to 35% (7/20) after chilling, and from 90% (36/40) to 45% (9/20) of the unshorn group. Sequencing of the 16S rRNA gene derived from 316 colonies of Enterobacteriaceae showed a tendency for the relative proportion of the genus Escherichia/Shigella, compared with other genera within Enterobacteriaceae, to be greater for unshorn, untreated sheep than from the other groups at the sampling locations along the meat chain. The study showed that steam vacuum and hot water pasteurisation reduced the contamination of carcasses derived from unshorn sheep, down to the level of the shorn group, and thus can replace the separate processing line for unshorn sheep. Indeed, the low microbial contamination in meat trimmings for all groups indicates that the separate processing line is unnecessary. Copyright © 2014 Elsevier B.V. All rights reserved.

Model Predictive Control of HVAC Systems: Implementation and Testing at the University of California, Merced

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haves, Phillip; Hencey, Brandon; Borrell, Francesco

2010-06-29

A Model Predictive Control algorithm was developed for the UC Merced campus chilled water plant. Model predictive control (MPC) is an advanced control technology that has proven successful in the chemical process industry and other industries. The main goal of the research was to demonstrate the practical and commercial viability of MPC for optimization of building energy systems. The control algorithms were developed and implemented in MATLAB, allowing for rapid development, performance, and robustness assessment. The UC Merced chilled water plant includes three water-cooled chillers and a two million gallon chilled water storage tank. The tank is charged during themore » night to minimize on-peak electricity consumption and take advantage of the lower ambient wet bulb temperature. The control algorithms determined the optimal chilled water plant operation including chilled water supply (CHWS) temperature set-point, condenser water supply (CWS) temperature set-point and the charging start and stop times to minimize a cost function that includes energy consumption and peak electrical demand over a 3-day prediction horizon. A detailed model of the chilled water plant and simplified models of the buildings served by the plant were developed using the equation-based modeling language Modelica. Steady state models of the chillers, cooling towers and pumps were developed, based on manufacturers performance data, and calibrated using measured data collected and archived by the control system. A detailed dynamic model of the chilled water storage tank was also developed and calibrated. Simple, semi-empirical models were developed to predict the temperature and flow rate of the chilled water returning to the plant from the buildings. These models were then combined and simplified for use in a model predictive control algorithm that determines the optimal chiller start and stop times and set-points for the condenser water temperature and the chilled water supply temperature. The report describes the development and testing of the algorithm and evaluates the resulting performance, concluding with a discussion of next steps in further research. The experimental results show a small improvement in COP over the baseline policy but it is difficult to draw any strong conclusions about the energy savings potential for MPC with this system only four days of suitable experimental data were obtained once correct operation of the MPC system had been achieved. These data show an improvement in COP of 3.1% {+-} 2.2% relative to a baseline established immediately prior to the period when the MPC was run in its final form. This baseline includes control policy improvements that the plant operators learned by observing the earlier implementations of MPC, including increasing the temperature of the water supplied to the chiller condensers from the cooling towers. The process of data collection and model development, necessary for any MPC project, resulted in the team uncovering various problems with the chilled water system. Although it is difficult to quantify the energy savings resulting from these problems being remedied, they were likely on the same order as the energy savings from the MPC itself. Although the types of problems uncovered and the level of energy savings may differ significantly from other projects, some of the benefits of detecting and diagnosing problems are expected from the use of MPC for any chilled water plant. The degree of chiller loading was found to be a key factor for efficiency. It is more efficient to operate the chillers at or near full load. In order to maximize the chiller load, one would maximize the temperature difference across chillers and the chilled water flow rate through the chillers. Thus, the CHWS set-point and the chilled water flow-rate can be used to limit the chiller loading to prevent chiller surging. Since the flow rate has an upper bound and the CHWS set point has a lower bound, the chiller loading is constrained and often determined by the chilled water return temperature (CHWR). The CHWR temperature is primarily comprised of warm water from the top of the TES tank. The CHWR temperature falls substantially as the thermocline approaches the top of the tank, which reduces the chiller loading. As a result, it has been determined that overcharging the TES tank can be detrimental to the chilled water plant efficiency. The resulting MPC policy differs from the current practice of fully charging the TES tank. A heuristic rule could possible avoid this problem without using predictive control. Similarly, the COP improvements from the change in CWS set-point were largely captured by a static set-point change by the operators. Further research is required to determine how much of the MPC savings could be garnered through simplified rules (based on the MPC study), with and without prediction.« less

Caste load and the evolution of reproductive skew.

PubMed

Holman, Luke

2014-01-01

Reproductive skew theory seeks to explain how reproduction is divided among group members in animal societies. Existing theory is framed almost entirely in terms of selection, though nonadaptive processes must also play some role in the evolution of reproductive skew. Here I propose that a genetic correlation between helper fecundity and breeder fecundity may frequently constrain the evolution of reproductive skew. This constraint is part of a wider phenomenon that I term "caste load," which is defined as the decline in mean fitness caused by caste-specific selection pressures, that is, differential selection on breeding and nonbreeding individuals. I elaborate the caste load hypothesis using quantitative and population genetic arguments and individual-based simulations. Although selection can sometimes erode genetic correlations and resolve caste load, this may be constrained when mutations have similar pleiotropic effects on breeder and helper traits. I document evidence for caste load, identify putative genomic adaptations to it, and suggest future research directions. The models highlight the value of considering adaptation within the boundaries imposed by genetic architecture and incidentally reaffirm that monogamy promotes the evolutionary transition to eusociality.

Do attitudes toward societal structure predict beliefs about free will and achievement? Evidence from the Indian caste system.

PubMed

Srinivasan, Mahesh; Dunham, Yarrow; Hicks, Catherine M; Barner, David

2016-01-01

Intuitive theories about the malleability of intellectual ability affect our motivation and achievement in life. But how are such theories shaped by the culture in which an individual is raised? We addressed this question by exploring how Indian children's and adults' attitudes toward the Hindu caste system--and its deterministic worldview--are related to differences in their intuitive theories. Strikingly, we found that, beginning at least in middle school and continuing into adulthood, individuals who placed more importance on caste were more likely to adopt deterministic intuitive theories. We also found a developmental change in the scope of this relationship, such that in children, caste attitudes were linked only to abstract beliefs about personal freedom, but that by adulthood, caste attitudes were also linked to beliefs about the potential achievement of members of different castes, personal intellectual ability, and personality attributes. These results are the first to directly relate the societal structure in which a person is raised to the specific intuitive theories they adopt. © 2015 John Wiley & Sons Ltd.

Development of an Optimization Methodology for the Aluminum Alloy Wheel Casting Process

NASA Astrophysics Data System (ADS)

Duan, Jianglan; Reilly, Carl; Maijer, Daan M.; Cockcroft, Steve L.; Phillion, Andre B.

2015-08-01

An optimization methodology has been developed for the aluminum alloy wheel casting process. The methodology is focused on improving the timing of cooling processes in a die to achieve improved casting quality. This methodology utilizes (1) a casting process model, which was developed within the commercial finite element package, ABAQUS™—ABAQUS is a trademark of Dassault Systèms; (2) a Python-based results extraction procedure; and (3) a numerical optimization module from the open-source Python library, Scipy. To achieve optimal casting quality, a set of constraints have been defined to ensure directional solidification, and an objective function, based on the solidification cooling rates, has been defined to either maximize, or target a specific, cooling rate. The methodology has been applied to a series of casting and die geometries with different cooling system configurations, including a 2-D axisymmetric wheel and die assembly generated from a full-scale prototype wheel. The results show that, with properly defined constraint and objective functions, solidification conditions can be improved and optimal cooling conditions can be achieved leading to process productivity and product quality improvements.

Low-cost single-crystal turbine blades, volume 1

NASA Technical Reports Server (NTRS)

Strangman, T. E.; Heath, B.; Fujii, M.

1983-01-01

The exothermic casting process was successfully developed into a low cost nonproprietary method for producing single crystal (SC) castings. Casting yields were lower than expected, on the order of 20 percent, but it is felt that the casting yield could be significantly improved with minor modifications to the process. Single crystal Mar-M 247 and two derivative SC alloys were developed. NASAIR 100 and SC Alloy 3 were fully characterized through mechanical property testing. SC Mar-M 247 shows no significant improvement in strength over directionally solidified (DS) Mar-M 247, but the derivative alloys, NASAIR 100 and Alloy 3, show significant tensile and fatigue improvements. The 1000 hr/238 MPa (20 ksi) stress rupture capability compared to DS Mar-M 247 was improved over 28 C. Firtree testing, holography, and strain gauge rig testing were used to evaluate the effects of the anisotropic characteristics of single crystal materials. In general, the single crystal material behaved similarly to DS Mar-M 247. Two complete engine sets of SC HP turbine blades were cast using the exothermic casting process and fully machined.

Comparison of directly compressed vitamin B12 tablets prepared from micronized rotary-spun microfibers and cast films.

PubMed

Sebe, István; Bodai, Zsolt; Eke, Zsuzsanna; Kállai-Szabó, Barnabás; Szabó, Péter; Zelkó, Romána

2015-01-01

Fiber-based dosage forms are potential alternatives of conventional dosage forms from the point of the improved extent and rate of drug dissolution. Rotary-spun polymer fibers and cast films were prepared and micronized in order to direct compress after homogenization with tabletting excipients. Particle size distribution of powder mixtures of micronized fibers and films homogenized with tabletting excipients were determined by laser scattering particle size distribution analyzer. Powder rheological behavior of the mixtures containing micronized fibers and cast films was also compared. Positron annihilation lifetime spectroscopy was applied for the microstructural characterization of micronized fibers and films. The water-soluble vitamin B12 release from the compressed tablets was determined. It was confirmed that the rotary spinning method resulted in homogeneous supramolecularly ordered powder mixture, which was successfully compressed after homogenization with conventional tabletting excipients. The obtained directly compressed tablets showed uniform drug release of low variations. The results highlight the novel application of micronized rotary-spun fibers as intermediate for further processing reserving the original favorable powder characteristics of fibrous systems.

Chilling Stress—The Key Predisposing Factor for Causing Alternaria alternata Infection and Leading to Cotton (Gossypium hirsutum L.) Leaf Senescence

PubMed Central

Zhao, Jingqing; Li, Sha; Jiang, Tengfei; Liu, Zhi; Zhang, Wenwei; Jian, Guiliang; Qi, Fangjun

2012-01-01

Leaf senescence plays a vital role in nutrient recycling and overall capacity to assimilate carbon dioxide. Cotton premature leaf senescence, often accompanied with unexpected short-term low temperature, has been occurring with an increasing frequency in many cotton-growing areas and causes serious reduction in yield and quality of cotton. The key factors for causing and promoting cotton premature leaf senescence are still unclear. In this case, the relationship between the pre-chilling stress and Alternaria alternata infection for causing cotton leaf senescence was investigated under precisely controlled laboratory conditions with four to five leaves stage cotton plants. The results showed short-term chilling stress could cause a certain degree of physiological impairment to cotton leaves, which could be recovered to normal levels in 2–4 days when the chilling stresses were removed. When these chilling stress injured leaves were further inoculated with A. alternata, the pronounced appearance and development of leaf spot disease, and eventually the pronounced symptoms of leaf senescence, occurred on these cotton leaves. The onset of cotton leaf senescence at this condition was also reflected in various physiological indexes such as irreversible increase in malondialdehyde (MDA) content and electrolyte leakage, irreversible decrease in soluble protein content and chlorophyll content, and irreversible damage in leaves' photosynthesis ability. The presented results demonstrated that chilling stress acted as the key predisposing factor for causing A. alternata infection and leading to cotton leaf senescence. It could be expected that the understanding of the key factors causing and promoting cotton leaf senescence would be helpful for taking appropriate management steps to prevent cotton premature leaf senescence. PMID:22558354

Climatic control of bud burst in young seedlings of nine provenances of Norway spruce.

PubMed

Søgaard, Gunnhild; Johnsen, Oystein; Nilsen, Jarle; Junttila, Olavi

2008-02-01

Detailed knowledge of temperature effects on the timing of dormancy development and bud burst will help evaluate the impacts of climate change on forest trees. We tested the effects of temperature applied during short-day treatment, duration of short-day treatment, duration of chilling and light regime applied during forcing on the timing of bud burst in 1- and 2-year-old seedlings of nine provenances of Norway spruce (Picea abies (L.) Karst.). High temperature during dormancy induction, little or no chilling and low temperature during forcing all delayed dormancy release but did not prevent bud burst or growth onset provided the seedlings were forced under long-day conditions. Without chilling, bud burst occurred in about 20% of seedlings kept in short days at 12 degrees C, indicating that young Norway spruce seedlings do not exhibit true bud dormancy. Chilling hastened bud burst and removed the long photoperiod requirement, but the effect of high temperature applied during dormancy induction was observed even after prolonged chilling. Extension of the short-day treatment from 4 to 8 or 12 weeks hastened bud burst. The effect of treatments applied during dormancy development was larger than that of provenance; in some cases no provenance effect was detected, but in 1-year-old seedlings, time to bud burst decreased linearly with increasing latitude of origin. Differences among provenances were complicated by different responses of some origins to light conditions under long-day forcing. In conclusion, timing of bud burst in Norway spruce seedlings is significantly affected by temperature during bud set, and these effects are modified by chilling and environmental conditions during forcing.

Cryobiology of coral fragments.

PubMed

Hagedorn, Mary; Farrell, Ann; Carter, Virginia L

2013-02-01

Around the world, coral reefs are dying due to human influences, and saving habitat alone may not stop this destruction. This investigation focused on the biological processes that will provide the first steps in understanding the cryobiology of whole coral fragments. Coral fragments are a partnership of coral tissue and endosymbiotic algae, Symbiodinium sp., commonly called zooxanthellae. These data reflected their separate sensitivities to chilling and a cryoprotectant (dimethyl sulfoxide) for the coral Pocillopora damicornis, as measured by tissue loss and Pulse Amplitude Modulated fluorometry 3weeks post-treatment. Five cryoprotectant treatments maintained the viability of the coral tissue and zooxanthellae at control values (1M dimethyl sulfoxide at 1.0, 1.5 and 2.0h exposures, and 1.5M dimethyl sulfoxide at 1.0 and 1.5h exposures, P>0.05, ANOVA), whereas 2M concentrations did not (P<0.05, ANOVA). A seasonal response to chilling was observed in the coral tissue, but not in the zooxanthellae. During the winter when the fragments were chilled, the coral tissue remained relatively intact (∼25% loss) post-treatment, but the zooxanthellae numbers in the tissue declined after 5min of chilling (P<0.05, ANOVA). However, in the late spring, coral tissue (∼75% loss) and zooxanthellae numbers declined in response to chilling alone (P<0.05, ANOVA). When a cryoprotectant (1M dimethyl sulfoxide) was used in concert with chilling it protected the coral against tissue loss after 45min of cryoprotectant exposure (P>0.05, ANOVA), but it did not protect against the loss of zooxanthellae (P<0.05, ANOVA). The zooxanthellae are the most sensitive element in the coral fragment complex and future cryopreservation protocols must be guided by their greater sensitivity. Copyright © 2012 Elsevier Inc. All rights reserved.

The application of multi-baseline digital close-range photogrammetry in three-dimensional imaging and measurement of dental casts.

PubMed

Fu, Xiaoming; Peng, Chun; Li, Zan; Liu, Shan; Tan, Minmin; Song, Jinlin

2017-01-01

To explore a new technique for reconstructing and measuring three-dimensional (3D) models of orthodontic plaster casts using multi-baseline digital close-range photogrammetry (MBDCRP) with a single-lens reflex camera. Thirty sets of orthodontic plaster casts that do not exhibit severe horizontal overlap (>2 mm) between any two teeth were recorded by a single-lens reflex camera with 72 pictures taken in different directions. The 3D models of these casts were reconstructed and measured using the open source software MeshLab. These parameters, including mesio-distal crown diameter, arch width, and arch perimeter, were recorded six times on both the 3D digital models and on plaster casts by two examiners. Statistical analysis was carried out using the Bland-Altman method to measure agreement between the novel method and the traditional calliper method by calculating the differences between mean values. The average differences between the measurements of the photogrammetric 3D models and the plaster casts were 0.011-0.402mm. The mean differences between measurements obtained by the photogrammetric 3D models and the dental casts were not significant except for the lower arch perimeter (P>0.05), and all the differences were regarded as clinically acceptable (<0.5 mm). Measurements obtained by MBDCRP are compared well with those obtained from plaster casts, indicating that MBDCRP is an alternate way to store and measure dental plaster casts without severe horizontal overlap between any two teeth.

Physiological responses to fluctuating temperatures are characterized by distinct transcriptional profiles in a solitary bee

USDA-ARS?s Scientific Manuscript database

Exposure to stressful, low temperatures during development can result in the accumulation of deleterious physiological effects called chill injury. Metabolic imbalances, disruptions in ion homeostasis, and oxidative stress contribute to the increased mortality of chill-injured insects. Interestingly...

Compositional redistribution during casting of Hg sub 0.8 Cd sub 0.2 Te alloys

NASA Technical Reports Server (NTRS)

Su, Ching-Hua; Perry, G. L. E.; Szofran, F. R.; Lehoczky, S. L.

1986-01-01

A series of Hg(0.8)Cd(0.2)Te ingots was cast both vertically and horizontally under well-defined thermal conditions by using a two-zone furnace with isothermal heat-pipe liners. The main objective of the experiments was to establish correlations between casting parameters and compositional redistribution and to develop ground-based data for a proposed flight experiment of casting of Hg(1-x)Cd(x)Te alloys under reduced gravity conditions. The compositional variations along the axial and radial directions were determined by precision density measurements, infrared transmission spectra, and X-ray energy dispersion spectrometry. Comparison between the experimental results and a numerical simulation of the solidification process of Hg(0.8)Cd(0.2)Te is described.

Protection of ultrastructure in chilling-stressed banana leaves by salicylic acid*

PubMed Central

Kang, Guo-zhang; Wang, Zheng-xun; Xia, Kuai-fei; Sun, Gu-chou

2007-01-01

Objective: Chilling tolerance of salicylic acid (SA) in banana seedlings (Musa acuminata cv., Williams 8818) was investigated by changes in ultrastructure in this study. Methods: Light and electron microscope observation. Results: Pretreatment with 0.5 mmol/L SA under normal growth conditions (30/22 °C) by foliar spray and root irrigation resulted in many changes in ultrastructure of banana cells, such as cells separation from palisade parenchymas, the appearance of crevices in cell walls, the swelling of grana and stromal thylakoids, and a reduction in the number of starch granules. These results implied that SA treatment at 30/22 °C could be a type of stress. During 3 d of exposure to 7 °C chilling stress under low light, however, cell ultrastructure of SA-pretreated banana seedlings showed less deterioration than those of control seedlings (distilled water-pretreated). Conclusion: SA could provide some protection for cell structure of chilling-stressed banana seedling. PMID:17444604

Identification of reference genes for RT-qPCR analysis in peach genotypes with contrasting chilling requirements.

PubMed

Marini, N; Bevilacqua, C B; Büttow, M V; Raseira, M C B; Bonow, S

2017-05-25

Selecting and validating reference genes are the first steps in studying gene expression by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR). The present study aimed to evaluate the stability of five reference genes for the purpose of normalization when studying gene expression in various cultivars of Prunus persica with different chilling requirements. Flower bud tissues of nine peach genotypes from Embrapa's peach breeding program with different chilling requirements were used, and five candidate reference genes based on the RT-qPCR that were useful for studying the relative quantitative gene expression and stability were evaluated using geNorm, NormFinder, and bestKeeper software packages. The results indicated that among the genes tested, the most stable genes to be used as reference genes are Act and UBQ10. This study is the first survey of the stability of reference genes in peaches under chilling stress and provides guidelines for more accurate RT-qPCR results.

Performance of swine chilled during artificial rearing.

PubMed

Stanton, H C; Mueller, R L

1977-07-01

There were more deaths among neonatal swine artificially reared for 21 days in individual cages at 27.9 C than among pigs reared under similar conditions at thermoneutrality (34.6 C). Furthermore, these deaths occurred at a younger age in the chilled animals. Chilled swine gained less body weight than did warm pigs for the first 15 days of life, although the survivors of the 27.9 C environment weighed the same as warm survivors at 22 days of age. Plasma glucose, liver, and skeletal muscle glycogen concentrations were significantly lower in neonatal swine exposed to 27.9 C from 1 to 4 days of age. Plasma nonesterified fatty acids, glycerol, cholesterol, and triglyceride concentrations were not altered by chilling. However, these lipid variables were significantly higher in 4-day-old nursig pigs than in animals reared artificially for the same period on artificial food. Adrenal gland weights and adrenal medullary catecholamine-synthetic enzyme activities were not altered by exposure to 27.9 C in pigs 1 to 4 days of age.

Low night temperature effect on photosynthate translocation of two C4 grasses.

PubMed

Potvin, C; Strain, B R; Goeschl, J D

1985-10-01

Translocation of assimilates in plants of Echinochloa crus-galli, from Quebec and Mississippi, and of Eleusine indica from Mississippi was monitored, before and after night chilling, using radioactive tracing with the short-life isotope 11 C. Plants were grown at 28°/22°C (day/night temperatures) under either 350 or 675 μl·l -1 CO 2 . Low night temperature reduced translocation mainly by increasing the turn-over times of the export pool. E. crus-galli plants from Mississippi were the most susceptible to chilling; translocation being completely inhibited by exposure for one night to 7°C at 350 μl·l -1 CO 2 . Overall, plants from Quebec were the most tolerant to chilling-stress. For plants of all three populations, growth under CO 2 enrichment resulted in higher 11 C activity in the leaf phloem. High CO 2 concentrations also seemed to buffer the transport system against chilling injuries.

Contribution of polyamines metabolism and GABA shunt to chilling tolerance induced by nitric oxide in cold-stored banana fruit.

PubMed

Wang, Yansheng; Luo, Zisheng; Mao, Linchun; Ying, Tiejin

2016-04-15

Effect of exogenous nitric oxide (NO) on polyamines (PAs) catabolism, γ-aminobutyric acid (GABA) shunt, proline accumulation and chilling injury of banana fruit under cold storage was investigated. Banana fruit treated with NO sustained lower chilling injury index than the control. Notably elevated nitric oxide synthetase activity and endogenous NO level were observed in NO-treated banana fruit. PAs contents in treated fruit were significantly higher than control fruit, due to the elevated activities of arginine decarboxylase and ornithine decarboxylase. NO treatment increased the activities of diamine oxidase, polyamine oxidase and glutamate decarboxylase, while reduced GABA transaminase activity to lower levels compared with control fruit, which resulted the accumulation of GABA. Besides, NO treatment upregulated proline content and significantly enhanced the ornithine aminotransferase activity. These results indicated that the chilling tolerance induced by NO treatment might be ascribed to the enhanced catabolism of PAs, GABA and proline. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low-temperature conditioning induces chilling tolerance in stored mango fruit.

PubMed

Zhang, Zhengke; Zhu, Qinggang; Hu, Meijiao; Gao, Zhaoyin; An, Feng; Li, Min; Jiang, Yueming

2017-03-15

In this study, mango fruit were pre-treated with low-temperature conditioning (LTC) at 12°C for 24h, followed by refrigeration at 5°C for 25days before removal to ambient temperature (25°C) to investigate the effects and possible mechanisms of LTC on chilling injury (CI). The results showed that LTC effectively suppressed the development of CI in mango fruit, accelerated softening, and increased the soluble solids and proline content. Furthermore, LTC reduced electrolyte leakage, and levels of malondialdehyde, O 2 - and H 2 O 2 , maintaining membrane integrity. To reveal the molecular regulation of LTC on chilling tolerance in mango fruit, a C-repeat/dehydration-responsive element binding factor (CBF) gene, MiCBF1, was identified and its expression in response to LTC was examined using RT-qPCR. LTC resulted in a higher MiCBF1 expression. These findings suggest that LTC enhances chilling tolerance in mango fruit by inducing a series of physiological and molecular responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of residual oxygen on colour stability during chill storage of sliced, pasteurised ham packaged in modified atmosphere.

PubMed

Møller, J K; Jensen, J S; Olsen, M B; Skibsted, L H; Bertelsen, G

2000-04-01

The critical level of residual oxygen to avoid light induced oxidative discoloration during chill storage of sliced, pasteurised ham packaged in modified atmosphere (20% carbon dioxide balanced with nitrogen in a 1:3 product to headspace volume ratio) was found to lie between 0.1 and 0.5% oxygen. In 0.5% oxygen light induced discoloration was significant, as detected by the tristimulus colorimetry redness parameter, when compared to the same product stored in the dark, while at 0.1 and 0.02% oxygen the colour was stable both in the dark and when exposed to light for up to 27 days in chill storage. Lipid oxidation, determined as 2-thiobarbituric acid-reactive substances, and total plate counts showed no difference between discoloured and colour stable products, although a trained panel in a triangle test could differentiate between the taste of ham from packages with 0.02 and 0.5% oxygen after 27 days of chill storage.

Corrosion Behavior of Nickel Alloy (ASTM A 494 M) Reinforced with Fused SiO2 Chilled Metal Matrix Composites (MMCs) for Marine Applications

NASA Astrophysics Data System (ADS)

Hemanth, Joel, Dr.

2017-08-01

This paper presents the results obtained and the discussions made from a series of corrosion experiments involving Nickel alloy (ASTM A 494 M) reinforced with fused SiO2, size of the particles dispersed varies from 80-120 µm and amount of addition varies from 3 to 12 wt.% in steps of 3 wt.%. The resulting chilled MMCs are solidified under the influence of copper chill of 25 mm thickness to study the effect of corrosion behavior. Corrosion resistance was found to increase significantly with increase in SiO2 content in chilled MMCs. Nevertheless, even with high SiO2 content corrosion attack ie., pitting was found to be most severe during the initial stages of each test but it invariably decreased to a very low value in the later stages, due to the formation of an adherent protective layer on the MMCs developed.

The efficacy of chlorine dioxide in controlling Salmonella contamination and its effect on product quality of chicken broiler carcasses.

PubMed

Thiessen, G P; Usborne, W R; Orr, H L

1984-04-01

A large spin-type chiller in an Ontario poultry processing plant was adapted so that the chill water could be treated with various levels of chlorine dioxide ( ClO2 ), increasing the concentration of ClO2 from 0 to 1.39 mg/liter resulting in reducing the bacteria count to the point where salmonellae could not be isolated from the chill water or the chilled broiler carcasses. In addition, coliform, psychrotroph , and aerobic plate counts were all greatly reduced (less than 1 log cycle) in chill water but were only slightly reduced (less than .5 log cycle) in macerated chicken broiler breast skin. Shelf-life was lengthened for broiler carcasses treated with 1.33 and 1.39 mg/liter ClO2 as compared to control carcasses. Sensory panelists reported no off flavors for any ClO2 concentration but rated broiler skin as being slightly lighter in color compared to control carcasses at all concentrations of ClO2 treatment.

EPA's ToxCast Project: Lessons learned and future directions for use of HTS in predicting in vivo toxicology -- A Chemical Perspective

EPA Science Inventory

U.S. EPA’s ToxCast and the related Tox21 projects are employing high-throughput screening (HTS) technologies to profile thousands of chemicals, which in turn serve as probes of a wide diversity of targets, pathways and mechanisms related to toxicity. Initial models relating ToxCa...

Dormancy termination of western white pine (Pinus monticola Dougl. Ex D. Don) seeds is associated with changes in abscisic acid metabolism.

PubMed

Feurtado, J Allan; Ambrose, Stephen J; Cutler, Adrian J; Ross, Andrew R S; Abrams, Suzanne R; Kermode, Allison R

2004-02-01

Western white pine (Pinus monticola) seeds exhibit deep dormancy at maturity and seed populations require several months of moist chilling to reach their uppermost germination capacities. Abscisic acid (ABA) and its metabolites, phaseic acid (PA), dihydrophaseic acid (DPA), 7'-hydroxy ABA (7'OH ABA) and ABA-glucose ester (ABA-GE), were quantified in western white pine seeds during dormancy breakage (moist chilling) and germination using an HPLC-tandem mass spectrometry method with multiple reaction monitoring and internal standards incorporating deuterium-labeled analogs. In the seed coat, ABA and metabolite levels were high in dry seeds, but declined precipitously during the pre-moist-chilling water soak to relatively low levels thereafter. In the embryo and megagametophyte, ABA levels decreased significantly during moist chilling, coincident with an increase in the germination capacity of seeds. ABA catabolism occurred via several routes, depending on the stage and the seed tissue. Moist chilling of seeds led to increases in PA and DPA levels in both the embryo and megagametophyte. Within the embryo, 7'OH ABA and ABA-GE also accumulated during moist chilling; however, 7'OH ABA peaked early in germination. Changes in ABA flux, i.e. shifts in the ratio between biosynthesis and catabolism, occurred at three distinct stages during the transition from dormant seed to seedling. During moist chilling, the relative rate of ABA catabolism exceeded ABA biosynthesis. This trend became even more pronounced during germination, and germination was also accompanied by a decrease in the ABA catabolites DPA and PA, presumably as a result of their further metabolism and/or leaching/transport. The transition from germination to post-germinative growth was accompanied by a shift toward ABA biosynthesis. Dormant imbibed seeds, kept in warm moist conditions for 30 days (after an initial 13 days of soaking), maintained high ABA levels, while the amounts of PA, 7'OH ABA, and DPA decreased or remained at steady-state levels. Thus, in the absence of conditions required to break dormancy there were no net changes in ABA biosynthesis and catabolism.

Effects of dormancy progression and low-temperature response on changes in the sorbitol concentration in xylem sap of Japanese pear during winter season.

PubMed

Ito, Akiko; Sugiura, Toshihiko; Sakamoto, Daisuke; Moriguchi, Takaya

2013-04-01

In order to elucidate which physiological event(s) are involved in the seasonal changes of carbohydrate dynamics during winter, we examined the effects of different low temperatures on the carbohydrate concentrations of Japanese pear (Pyrus pyrifolia (Burm.) Nakai). For four winter seasons, large increases in the sorbitol concentration of shoot xylem sap occurred during mid- to late December, possibly due to the endodormancy completion and low-temperature responses. When trees were kept at 15 °C from 3 November to 3 December in order to postpone the initiation and completion of chilling accumulation that would break endodormancy, sorbitol accumulation in xylem sap was always higher from trees with sufficient chilling accumulation than from trees that received insufficient chilling. However, an additional increase in xylem sap sorbitol occurred around late December in trees regardless of whether their chilling accumulation naturally progressed or was postponed. To examine different temperature effects more closely, we compared the carbohydrate concentrations of trees subjected to either 6 or 0 °C treatment. The sorbitol concentration in xylem sap tremendously increased at 0 °C treatment compared with 6 °C treatment. However, an additional increase in xylem sap sorbitol occurred at both the temperatures when sufficient chilling accumulated with a peak coinciding with the peak expression in shoots of the sorbitol transporter gene (PpSOT2). Interestingly, the total carbohydrate concentration of shoots tremendously increased with exposure to 0 °C compared with exposure to 6 °C, but was not affected by the amount of accumulated chilling. Instead, as chilling accumulated the ratio of sorbitol to total soluble sugars in shoots increased. We presumed that carbohydrates in the shoot tissues may be converted to sorbitol and loaded into the xylem sap so that the sorbitol accumulation patterns were synchronized with the progression of dormancy, whereas the total carbohydrate transported into shoots from other storage organs may be related to freezing tolerance acquisition independent of dormancy progression. We thus propose that there are different effects of dormancy progression and low-temperature responses on carbohydrate dynamics in Japanese pear.

Transcriptomic changes in Cucurbita pepo fruit after cold storage: differential response between two cultivars contrasting in chilling sensitivity.

PubMed

Carvajal, F; Rosales, R; Palma, F; Manzano, S; Cañizares, J; Jamilena, M; Garrido, D

2018-02-07

Zucchini fruit is susceptible to chilling injury (CI), but the response to low storage temperature is cultivar dependent. Previous reports about the response of zucchini fruit to chilling storage have been focused on the physiology and biochemistry of this process, with little information about the molecular mechanisms underlying it. In this work, we present a comprehensive analysis of transcriptomic changes that take place after cold storage in zucchini fruit of two commercial cultivars with contrasting response to chilling stress. RNA-Seq analysis was conducted in exocarp of fruit at harvest and after 14 days of storage at 4 and 20 °C. Differential expressed genes (DEGs) were obtained comparing fruit stored at 4 °C with their control at 20 °C, and then specific and common up and down-regulated DEGs of each cultivar were identified. Functional analysis of these DEGs identified similarities between the response of zucchini fruit to low temperature and other stresses, with an important number of GO terms related to biotic and abiotic stresses overrepresented in both cultivars. This study also revealed several molecular mechanisms that could be related to chilling tolerance, since they were up-regulated in cv. Natura (CI tolerant) or down-regulated in cv. Sinatra (CI sensitive). These mechanisms were mainly those related to carbohydrate and energy metabolism, transcription, signal transduction, and protein transport and degradation. Among DEGs belonging to these pathways, we selected candidate genes that could regulate or promote chilling tolerance in zucchini fruit including the transcription factors MYB76-like, ZAT10-like, DELLA protein GAIP, and AP2/ERF domain-containing protein. This study provides a broader understanding of the important mechanisms and processes related to coping with low temperature stress in zucchini fruit and allowed the identification of some candidate genes that may be involved in the acquisition of chilling tolerance in this crop. These genes will be the basis of future studies aimed to identify markers involved in cold tolerance and aid in zucchini breeding programs.

Culture in Psychiatric Epidemiology: Using Ethnography and Multiple Mediator Models to Assess the Relationship of Caste with Depression and Anxiety in Nepal

PubMed Central

Kohrt, Brandon A.; Speckman, Rebecca A.; Kunz, Richard D.; Baldwin, Jennifer L.; Upadhaya, Nawaraj; Acharya, Nanda Raj; Sharma, Vidya Dev; Nepal, Mahendra K.; Worthman, Carol M.

2013-01-01

Background The causes of ethnic and caste-based disparities in mental health are poorly understood. Aim To identify mediators underlying caste-based disparities in mental health in Nepal. Subjects and methods A mixed methods ethnographic and epidemiological study of 307 adults (Dalit/Nepali, n=75; high caste Brahman and Chhetri, n=232) assessed with Nepali versions of Beck Depression (BDI) and Anxiety (BAI) Inventories. Results One third (33.7%) of participants were classified as depressed: Dalit/Nepali 50.0%, high caste 28.4%. One quarter (27.7%) of participants were classified as anxious: Dalit/Nepali 50.7%, high caste 20.3%. Ethnographic research identified four potential mediators: stressful life events, owning few livestock, no household income, and lack of social support. The direct effect of caste was 1.08 (95% CI -1.10—3.27) on depression score and 4.76 (95% CI 2.33—7.19) on anxiety score. All four variables had significant indirect (mediation) effects on anxiety, and all but social support had significant indirect effects on depression. Conclusion Caste-based disparities in mental health in rural Nepal are statistically mediated by poverty, lack of social support, and stressful life events. Interventions should target these areas to alleviate the excess mental health burden born by Dalit/Nepali women and men. PMID:19381985

Culture in psychiatric epidemiology: using ethnography and multiple mediator models to assess the relationship of caste with depression and anxiety in Nepal.

PubMed

Kohrt, Brandon A; Speckman, Rebecca A; Kunz, Richard D; Baldwin, Jennifer L; Upadhaya, Nawaraj; Acharya, Nanda Raj; Sharma, Vidya Dev; Nepal, Mahendra K; Worthman, Carol M

2009-01-01

The causes of ethnic and caste-based disparities in mental health are poorly understood. The study aimed to identify mediators underlying caste-based disparities in mental health in Nepal. A mixed methods ethnographic and epidemiological study of 307 adults (Dalit/Nepali, n=75; high caste Brahman and Chhetri, n=232) was assessed with Nepali versions of Beck Depression (BDI) and Anxiety (BAI) Inventories. One-third (33.7%) of participants were classified as depressed: Dalit/Nepali 50.0%, high caste 28.4%. One quarter (27.7%) of participants were classified as anxious: Dalit/Nepali 50.7%, high caste 20.3%. Ethnographic research identified four potential mediators: Stressful life events, owning few livestock, no household income, and lack of social support. The direct effect of caste was 1.08 (95% CI -1.10-3.27) on depression score and 4.76 (95% CI 2.33-7.19) on anxiety score. All four variables had significant indirect (mediation) effects on anxiety, and all but social support had significant indirect effects on depression. Caste-based disparities in mental health in rural Nepal are statistically mediated by poverty, lack of social support, and stressful life events. Interventions should target these areas to alleviate the excess mental health burden born by Dalit/Nepali women and men.

Competitive allele-specific TaqMan PCR (Cast-PCR) is a sensitive, specific and fast method for BRAF V600 mutation detection in Melanoma patients

PubMed Central

Barbano, Raffaela; Pasculli, Barbara; Coco, Michelina; Fontana, Andrea; Copetti, Massimiliano; Rendina, Michelina; Valori, Vanna Maria; Graziano, Paolo; Maiello, Evaristo; Fazio, Vito Michele; Parrella, Paola

2015-01-01

BRAF codon 600 mutation testing of melanoma patients is mandatory for the choice of the most appropriate therapy in the clinical setting. Competitive allele specific TaqMan PCR (Cast-PCR) technology allows not only the selective amplification of minor alleles, but it also blocks the amplification of non-mutant allele. We genotyped codon 600 of the BRAF gene in 54 patients’ samples by Cast-PCR and bidirectional direct sequence analysis. All the mutations detected by sequencing were also identified by Cast-PCR. In addition, Cast-PCR assay detected four samples carrying mutations and was able to clearly identify two mutations of uncertain interpretation by Sanger sequencing. The limit of detection of Cast-PCR was evaluated by constructing dilution curves of BRAFV600E and BRAFV600K mutated clinical samples mixed with a not-mutated specimens. Both mutations could be detected until a 1:100 mutated/not mutated ratio. Cloning and sequencing of the clones was used to confirm mutations on representative discrepant cases. Cast PCR performances were not affected by intratumour heterogeneity, and less affected by melanin content. Our results indicate that Cast-PCR is a reliable diagnostic tool for the identification of melanoma patients as eligible to be treated with TKIs and might be implemented in the clinical setting as elective screening method. PMID:26690267

Growth of Salmonella on chilled meat.

PubMed Central

Mackey, B. M.; Roberts, T. A.; Mansfield, J.; Farkas, G.

1980-01-01

Growth rates of a mixture of Salmonella serotypes inoculated on beef from a commercial abattoir were measured at chill temperatures. The minimum recorded mean generation times were 8.1 h at 10 degrees C; 5.2 h at 12.5 degrees C and 2.9 h at 15 degrees C. Growth did not occur at 7-8 degrees C. From these data the maximum extent of growth of Salmonella during storage of meat for different times at chill temperatures was calculated. Criteria for deciding safe handling temperatures for meat are discussed. Maintaining an internal temperature below 10 degrees C during the boning operation would be sufficient to safeguard public health requirements. PMID:7052227

Controlled atmosphere storage, temperature conditioning, and antioxidant treatment alter postharvest 'Honeycrisp' metabolism

USDA-ARS?s Scientific Manuscript database

The physiology and metabolism characterizing postharvest chilling and CO2 injury in apple has important implications for postharvest management of soft scald and soggy breakdown. This research assessed differences of primary metabolism related to soggy breakdown (cortex chilling injury) and CO2 cor...

Method for Fabricating Soft Tissue Implants with Microscopic Surface Roughness

NASA Technical Reports Server (NTRS)

Banks, Bruce A. (Inventor); Rutledge, Sharon K. (Inventor)

1999-01-01

A method for fabricating soft tissue implants using a mold. The cavity surface of an initially untextured mold. made of an organic material such as epoxy. is given a thin film coating of material that has pinholes and is resistant to atomic particle bombardment. The mold cavity surface is then subjected to atomic particle bombardment, such as when placed in an isotropic atomic oxygen environment. Microscopic depressions in the mold cavity surface are created at the pinhole sites on the thin film coating. The thin film coating is removed and the mold is then used to cast the soft tissue implant. The thin film coating having pinholes may be created by chilling the mold below the dew point such that water vapor condenses upon it; distributing particles, that can partially dissolve and become attached to the mold cavity surface, onto the mold cavity surface; removing the layer of condensate, such as by evaporation; applying the thin film coating over the entire mold surface; and, finally removing the particles, such as by dissolving or brushing it off. Pinholes are created in the thin film coating at the sites previously occupied by the particles.

Application of Taguchi Method for Analyzing Factors Affecting the Performance of Coated Carbide Tool When Turning FCD700 in Dry Cutting Condition

NASA Astrophysics Data System (ADS)

Ghani, Jaharah A.; Mohd Rodzi, Mohd Nor Azmi; Zaki Nuawi, Mohd; Othman, Kamal; Rahman, Mohd. Nizam Ab.; Haron, Che Hassan Che; Deros, Baba Md

2011-01-01

Machining is one of the most important manufacturing processes in these modern industries especially for finishing an automotive component after the primary manufacturing processes such as casting and forging. In this study the turning parameters of dry cutting environment (without air, normal air and chilled air), various cutting speed, and feed rate are evaluated using a Taguchi optimization methodology. An orthogonal array L27 (313), signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are employed to analyze the effect of these turning parameters on the performance of a coated carbide tool. The results show that the tool life is affected by the cutting speed, feed rate and cutting environment with contribution of 38%, 32% and 27% respectively. Whereas for the surface roughness, the feed rate is significantly controlled the machined surface produced by 77%, followed by the cutting environment of 19%. The cutting speed is found insignificant in controlling the machined surface produced. The study shows that the dry cutting environment factor should be considered in order to produce longer tool life as well as for obtaining a good machined surface.

The structure and properties of a nickel-base superalloy produced by osprey atomization-deposition

NASA Astrophysics Data System (ADS)

Bricknell, Rodger H.

1986-04-01

The production of a nickel-base superalloy, René* 80, by the Osprey atomization-deposition process has been investigated. Dense (>99 pct) material with a fine-grained equiaxed microstructure was deposited using either argon or nitrogen as the atomizing gas. Defects present in the material included a chill region at the collector plate interface, entrapped recirculated particles, porosity, and ceramic particles from the melting and dispensing system. In contrast to other rapid solidification techniques, low oxygen pick-ups are noted in the current technique. Tensile strengths above those displayed by castings are found in both nitrogen and argon atomized material, and in both the as-deposited and heat treated conditions. In addition, no profound mid-temperature ductility loss is displayed by this low oxygen material, in contrast to results on other rapidly solidified material with high oxygen contents. These results are explained in terms of oxygen embrittlement. In view of the excellent properties measured, the attractive economics of the process, and the fact that fine control of the gas/metal flow ratio is shown to be unnecessary, it is concluded that atomization-deposition presents an attractive potential production route for advanced alloys.

Semen evaluation and fertility assessment in a purebred dog breeding facility.

PubMed

Hesser, Andrea; Darr, Christa; Gonzales, Kris; Power, Heather; Scanlan, Tawny; Thompson, James; Love, Charles; Christensen, Bruce; Meyers, Stuart

2017-01-01

Semen quality in dogs has not been assessed in a longitudinal study that includes endpoints of female fertility and pregnancy. Although use of artificial insemination with chilled semen is increasingly used in canine reproduction, the resultant level of predictability and odds of fertile matings for dogs is still not fully understood. This research provides, for the first time, comprehensive semen evaluation in a large population of dogs in which fertility has been tracked. Duplicate ejaculates were obtained from 39 Labrador retriever males of the Guide Dogs for the Blind (San Rafael, CA, USA) breeding program. Sperm endpoints were determined in fresh semen and extended chilled semen at 48 hour after collection. Evaluation included total and progressive motility, average path velocity, morphology, membrane lipid peroxidation, presence of sperm reactive oxygen species, sperm chromatin structure, and mitochondrial DNA copy number. Male age ranged from 1 to 10 years and were grouped as young (Y; 1-3 years, n = 21), middle aged (M; 4-6 years, n = 13), and senior (S; 7 years or greater, n = 5) for analysis. The effects of age and sperm state (fresh vs. chilled) on the above sperm endpoints were determined using a linear mixed effects model. Semen endpoint values for all parameters were established for this group of fertile males. Progressive motility was only lower in the senior male chilled samples compared to all other groups, fresh and chilled (P < 0.05). Velocity decreased with increasing age and was lower overall in chilled samples (P < 0.05). Percent morphologically normal sperm was lower in senior dogs compared with the other age groups (P < 0.05). The presence of reactive oxygen species was lower in chilled samples compared with fresh (P < 0.05). For sperm chromatin structure, the senior-aged group had a higher %COMPα t than the middle-aged group (P < 0.05). Bayesian analysis determined that no differences were seen in total motility, membrane lipid peroxidation, and mitochondrial DNA copy number, with regard to conception rate or average litter size between age groups or between fresh and chilled samples. We observed no effects from semen quality on fertility or fecundity regardless of age, despite the differences found in semen quality. The use of advanced laboratory tests to evaluate sperm parameters beyond the standard motility, morphology, and concentration will open investigation to more specific and sensitive fertility tests in canine reproduction. Copyright © 2016 Elsevier Inc. All rights reserved.

On the quality of commercial boneless skinless broiler breast meat.

PubMed

Lee, Y S; Owens, C M; Meullenet, J F

2008-08-01

This study was conducted to assess the overall quality of commercial broiler breast meat products representing several brands and various industry practices (that is, chilling or enhancement procedures). Six different broiler breast products were evaluated by 75 consumers for 11 attributes related to appearance, flavor, tenderness, and juiciness, including overall acceptance. Twenty-three sensory attributes representing basic taste, flavor, texture, and appearance were evaluated by 11 trained descriptive panelists. Tenderness of cooked meat was instrumentally predicted by the Meullenet-Owens razor shear (MORS). Water holding capacity (cook loss) of cooked meat was also evaluated, and color and pH of raw meat were determined. Significant variations in quality among products tested were reported, indicating a broad range of product quality in the marketplace. One air-chilled and 1 water-chilled/enhanced product were found to be most liked by consumers. Tenderness of products tested was rated in average between "neither tough nor tender" and "very tender" by consumers. Cook loss of the 2 air-chilled products (13.5% to 19.1%, respectively) was significantly lower than that of water-chilled products (18.7% to 24.1%). Partial least squares regression revealed that 4 sensory texture attributes (hardness, hardness of mass, cohesiveness of mass, and tooth pack) and 1 basic taste (sour) were the major attributes driving consumer overall liking of commercial broiler breast meat products.

Drivers of leaf-out phenology and their implications for species invasions: insights from Thoreau's Concord.

PubMed

Polgar, Caroline; Gallinat, Amanda; Primack, Richard B

2014-04-01

To elucidate climate-driven changes in leaf-out phenology and their implications for species invasions, we observed and experimentally manipulated leaf out of invasive and native woody plants in Concord, MA, USA. Using observations collected by Henry David Thoreau (1852-1860) and our own observations (2009-2013), we analyzed changes in leaf-out timing and sensitivity to temperature for 43 woody plant species. We experimentally tested winter chilling requirements of 50 species by exposing cut branches to warm indoor temperatures (22°C) during the winter and spring of 2013. Woody species are now leafing out an average of 18 d earlier than they did in the 1850s, and are advancing at a rate of 5 ± 1 d °C(-1) . Functional groups differ significantly in the duration of chilling they require to leaf out: invasive shrubs generally have weaker chilling requirements than native shrubs and leaf out faster in the laboratory and earlier in the field; native trees have the strongest chilling requirements. Our results suggest that invasive shrub species will continue to have a competitive advantage as the climate warms, because native plants are slower to respond to warming spring temperatures and, in the future, may not meet their chilling requirements. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Global Expression Profiling of Low Temperature Induced Genes in the Chilling Tolerant Japonica Rice Jumli Marshi

PubMed Central

Chawade, Aakash; Lindlöf, Angelica; Olsson, Björn; Olsson, Olof

2013-01-01

Low temperature is a key factor that limits growth and productivity of many important agronomical crops worldwide. Rice (Oryza sativa L.) is negatively affected already at temperatures below +10°C and is therefore denoted as chilling sensitive. However, chilling tolerant rice cultivars exist and can be commercially cultivated at altitudes up to 3,050 meters with temperatures reaching as low as +4°C. In this work, the global transcriptional response to cold stress (+4°C) was studied in the Nepalese highland variety Jumli Marshi (spp. japonica) and 4,636 genes were identified as significantly differentially expressed within 24 hours of cold stress. Comparison with previously published microarray data from one chilling tolerant and two sensitive rice cultivars identified 182 genes differentially expressed (DE) upon cold stress in all four rice cultivars and 511 genes DE only in the chilling tolerant rice. Promoter analysis of the 182 genes suggests a complex cross-talk between ABRE and CBF regulons. Promoter analysis of the 511 genes identified over-represented ABRE motifs but not DRE motifs, suggesting a role for ABA signaling in cold tolerance. Moreover, 2,101 genes were DE in Jumli Marshi alone. By chromosomal localization analysis, 473 of these cold responsive genes were located within 13 different QTLs previously identified as cold associated. PMID:24349120

New icing media for quality enhancement of chilled hake (Merluccius merluccius) using a jumbo squid (Dosidicus gigas) skin extract.

PubMed

Ezquerra-Brauer, Josafat Marina; Miranda, José M; Chan-Higuera, Jesús Enrique; Barros-Velázquez, Jorge; Aubourg, Santiago P

2017-08-01

An advanced strategy for chilled fish preservation, based on the inclusion in ice of an extract of jumbo squid (Dosidicus gigas) skin (JSS), is proposed. Aqueous solutions including acetic acid-ethanol extracts of JSS were tested at two different concentrations as icing media, with the effects on the quality evolution of chilled hake (Merluccius merluccius) being monitored. A significant inhibition (P < 0.05) of microbial activity (aerobes, psychrotrophs, Enterobacteriaceae, proteolytic bacteria; pH, trimethylamine) was obtained in hake corresponding to the icing batch including the highest JSS concentration. Additionally, fish specimens from such icing conditions showed an inhibitory effect (P < 0.05) on lipid hydrolysis development, while no effect (P > 0.05) was depicted for lipid oxidation. Sensory analysis (skin and mucus development; eyes; gills; texture; external odour; raw and cooked flesh odour; flesh taste) indicated a shelf life extension of chilled hake stored in ice including the highest JSS concentration. A profitable use of JSS, an industrial by-product during jumbo squid commercialisation, has been developed in the present work, which leads to a remarkable microbial inhibition and a significant shelf life extension of chilled hake. In agreement with previous research, ommochrome pigments (i.e. lipophilic-type compounds) would be considered responsible for this preservative effect. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Chapter 14: Chiller Evaluation Protocol. The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurnik, Charles W; Tiessen, Alex

This protocol defines a chiller measure as a project that directly impacts equipment within the boundary of a chiller plant. A chiller plant encompasses a chiller - or multiple chillers - and associated auxiliary equipment. This protocol primarily covers electric-driven chillers and chiller plants. It does not include thermal energy storage and absorption chillers fired by natural gas or steam, although a similar methodology may be applicable to these chilled water system components.

Why Cold-Wet Makes One Feel Chilled: A Literature Review

DTIC Science & Technology

1988-06-01

froid et mouill6. On examine aussi l’effet de la radiation solaire , l’interaction entre la peau at l’humidit6, entre la peau et la temp~rature de mgme...directions, including back out into space. Aerosols of water in clouds reflect incident solar energy . The upper surface of a stratus cloud cover can reflect...earth than under clear conditions. Albedo, the fraction of the incident energy which is reflected by a surface, varies considerably with the terrain

40 CFR 467.32 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... and grease 7.32 4.39 Suspended solids 15.0 7.13 pH (1) (1) 1 Within the range of 7.0 to 10.0 at all... solids 60.60 28.82 pH (1) (1) 1 With the range of 7.0 to 10.0 at all times. Subpart C Direct Chill... wastewater in which case the pH shall be within the range of 6.0 to 10.0 at all times. Subpart C Press Heat...

40 CFR 467.32 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... and grease 7.32 4.39 Suspended solids 15.0 7.13 pH (1) (1) 1 Within the range of 7.0 to 10.0 at all... solids 60.60 28.82 pH (1) (1) 1 With the range of 7.0 to 10.0 at all times. Subpart C Direct Chill... wastewater in which case the pH shall be within the range of 6.0 to 10.0 at all times. Subpart C Press Heat...

Development of chloride-induced corrosion in pre-cracked RC beams under sustained loading: Effect of load-induced cracks, concrete cover, and exposure conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Linwen; Université de Sherbrooke, Quebec; François, Raoul, E-mail: raoul.francois@insa-toulouse.fr

2015-01-15

This paper deals with corrosion initiation and propagation in pre-cracked reinforced concrete beams under sustained loading during exposure to a chloride environment. Specimen beams that were cast in 2010 were compared to specimens cast in 1984. The only differences between the two sets of beams were the casting direction in relation to tensile reinforcement and the exposure conditions in the salt-fog chamber. The cracking maps, corrosion maps, chloride profiles, and cross-sectional loss of one group of two beams cast in 2010 were studied and their calculated corrosion rates were compared to that of beams cast in 1984 in order tomore » investigate the factors influencing the natural corrosion process. Experimental results show that, after rapid initiation of corrosion at the crack tip, the corrosion process practically halted and the time elapsing before corrosion resumed depended on the exposure conditions and cover depth.« less

Fixture for forming evaporative pattern (EPC) process patterns

DOEpatents

Turner, Paul C.; Jordan, Ronald R.; Hansen, Jeffrey S.

1993-01-01

A method of casting metal using evaporative pattern casting process patterns in combination with a fixture for creating and maintaining a desired configuration in flexible patterns. A pattern is constructed and gently bent to the curvature of a suitable fixture. String or thin wire, which burns off during casting, is used to tie the pattern to the fixture. The fixture with pattern is dipped in a commercially available refractory wash to prevent metal adherence and sticking to the fixture. When the refractory wash is dry, the fixture and pattern are placed in a flask, and sand is added and compacted by vibration. The pattern remains in position, restrained by the fixture. Metal that is poured directly into the pattern replaces the pattern exactly but does not contact or weld to the fixture due to the protective refractory layer. When solid, the casting is easily separated from the fixture. The fixture can be cleaned for reuse in conventional casting cleaning equipment.

Influence of Ni Interlayer on Microstructure and Mechanical Properties of Mg/Al Bimetallic Castings

NASA Astrophysics Data System (ADS)

Liu, Ning; Liu, Canchun; Liang, Chunyong; Zhang, Yongguang

2018-05-01

Dissimilar joining of magnesium and aluminum using a compound casting process was investigated in the present work. For the first time, a Ni interlayer prepared by plasma spraying was inserted between the two base metals to improve the interfacial characteristics. Examination of the interfacial regions using scanning electron microscopy, energy-dispersive X-ray spectroscopy, electron probe microanalysis, and X-ray diffraction revealed the formation of a three-layered interface between Mg and Al without the interlayer. The thickness of the interface was approximately 600 μm when the casting was performed at 700 °C and increased with increasing casting temperature. However, with the addition of the Ni interlayer, the Al-Mg reaction was successfully prevented, and metallurgical bonding between the Ni interlayer and two base metals was achieved at a casting temperature of 700 °C. Upon increasing this temperature, Mg-Ni and Al-Ni intermetallics were generated at the separate interfaces. The shear strength of the Mg/Al bimetallic castings with the Ni interlayer was substantially improved compared with that of the direct Mg/Al joint, with a maximum value of 25.4 MPa achieved at 700 °C. Fracture occurred mainly along the Mg/Ni interface for the Mg/Ni/Al multilayer structure castings.

Contact angle control of sessile drops on a tensioned web

NASA Astrophysics Data System (ADS)

Park, Janghoon; Kim, Dongguk; Lee, Changwoo

2018-04-01

In this study, the influence of the change of tension applied to flexible and thin web substrate on the contact angle of sessile drop in roll-to-roll system was investigated. Graphene oxide and deionized water solutions were used in the experiments. Tension was changed to 29, 49, and 69 N, and the casting distance of the micropipette and the material was set to 10, 20, and 40 mm, and the droplet volume was set to 10, 20, and 30 μL, respectively. Statistical analysis of three variables and analysis of the variance methodology showed that the casting distance was most significant for the contact angle change, and the most interesting tension variable was also affected. The change in tension caused the maximum contact angle to change by 5.5°. The tension was not uniform in the width direction. When the droplet was applied in the same direction in the width direction, it was confirmed that the tension unevenness had great influence on the contact angle up to 11°. Finally, the casting distance, which has a large effect on the contact angle, was calibrated in the width direction to reduce the width direction contact angle deviation to 1%. This study can be applied to fine patterning research using continuous inkjet printing and aerosol jet printing, which are roll-to-roll processes based on droplet handling.

Convective and radiative components of wind chill in sheep: Estimation from meteorological records

NASA Astrophysics Data System (ADS)

Brown, D.; Mount, L. E.

1987-06-01

Wind chill is defined as the excess of sensible heat loss over what would occur at zero wind speed with other conditions unchanged. Wind chill can be broken down into a part that is determined by air temperature and a radiative part that comprises wind-dependent effects on additional long-wave radiative exchange and on solar radiation (by reducing solar warming). Radiative exchange and gain from solar radiation are affected by changes that are produced by wind in both surface and fleece insulations. Coefficients are derived for (a) converting the components of sensible heat exchange (air-temperature-dependent including both convective and associated long-wave radiative, additional long-wave radiative and solar) into the components of the total heat loss that are associated with wind and (b) for calculating equivalent air temperature changes. The coefficients contain terms only in wind speed, wetting of the fleece and fleece depth; these determine the external insulation. Calculation from standard meteorological records, using Plymouth and Aberdeen in 1973 as examples, indicate that in April September 1973 at Plymouth reduction in effective solar warming constituted 28% of the 24-h total wind chill, and 7% in the other months of the year combined; at Aberdeen the corresponding percentages were 25% and 6%. Mean hour-of-day estimates for the months of April and October showed that at midday reduction in solar warming due to wind rose to the order of half the air-temperature-dependent component of wind chill, with a much smaller effect in January. For about six hours at midday in July reduction in solar warming due to wind was similar in magnitude to the air-temperature-dependent component. It is concluded that realistic estimates of wind chill cannot be obtained unless the effect of solar radiation is taken into account. Failure to include solar radiation results not only in omitting solar warming but also in omitting the effects of wind in reducing that warming. The exchange of sensible (non-evaporative) heat loss between a homeothermic animal and its environment can be divided into two parts: one part is due to the temperature difference between the animal and the surrounding air, and the other part is due to additional long-wave radiative exchange between animal and environment and to solar radiation. Both parts of the heat exchange are determined in magnitude by the animal's thermal insulation, which is itself affected by windspeed and wetting. Wind diminishes as animal's external insulation, so increasing heat loss under all conditions when the air temperature is lower than the animal's surface temperature: this effect is termed wind chill. Wind chill has previously been investigated more commonly in relation to man (Burton an Edholm, 1955; Smithson and Baldwin, 1978; Mumford, 1979; Baldwin and Smithson, 1979). This paper is concerned with the separate contributions to wind chill calculated for sheep that can be associated with convective and radiative heat exchanges.

Eutectic Formation During Solidification of Ni-Based Single-Crystal Superalloys with Additional Carbon

NASA Astrophysics Data System (ADS)

Wang, Fu; Ma, Dexin; Bührig-Polaczek, Andreas

2017-11-01

γ/ γ' eutectics' nucleation behavior during the solidification of a single-crystal superalloy with additional carbon was investigated by using directional solidification quenching method. The results show that the nucleation of the γ/ γ' eutectics can directly occur on the existing γ dendrites, directly in the remaining liquid, or on the primary MC-type carbides. The γ/γ' eutectics formed through the latter two mechanisms have different crystal orientations than that of the γ matrix. This suggests that the conventional Ni-based single-crystal superalloy castings with additional carbon only guarantee the monocrystallinity of the γ matrix and some γ/ γ' eutectics and, in addition to the carbides, there are other misoriented polycrystalline microstructures existing in macroscopically considered "single-crystal" superalloy castings.

9 CFR 441.10 - Retained water.

Code of Federal Regulations, 2014 CFR

2014-01-01

... standard for Salmonella as set forth in the PR/HACCP regulations (9 CFR 310.25(b), 381.94(b)) and the time... chillers in a series and arrangements of chilling system components, and the number of evisceration lines... equipment used should be accurately described. Any mechanical or design changes made to the chilling...

Mapping quantitative trait loci associated with chilling requirement, heat requirement and bloom date in peach [Prunus persica (L.) Batsch

USDA-ARS?s Scientific Manuscript database

Chilling requirement (CR), together with heat requirement (HR), determines blooming date (BD) and climatic distribution of genotypes of temperate tree species. However, information on the genetic components underlying these important traits remains unknown or fragmentary. Here the identification o...

A metabolic profile for ‘Honeycrisp’ apple soggy breakdown, a chilling induced physiological disorder

USDA-ARS?s Scientific Manuscript database

‘Honeycrisp’ is an economically important apple cultivar increasing rapidly in planted acreage in many apple growing regions. Long-term cold storage can enhance value by enabling a longer window of availability, but the cultivar is highly susceptible to chilling induced disorders. Soggy breakdown ...

Guns on Campus: A Chilling Effect

ERIC Educational Resources Information Center

Mash, Kenneth M.

2013-01-01

The author of this article observes that, while much has been written on the overall topic of safety with regard to allowing guns on college campuses, little has been said about how allowing the possession of deadly weapons can create a "chilling effect" on academic discussions. This article considers how some universities have…

[Customer satisfaction study in two roman hospitals: comparison between "cook & serve" and "cook & chill"].

PubMed

Perata, E; Ferrari, P; Tarsitani, G

2005-01-01

We studied patient's satisfaction rate for hospital dishes comparing "cook & chill" method with "cook & serve". As principal instrument we used a comparative questionnaire, anonymous and self-compiled, which is able to evaluate the differences of customer satisfaction's rate between the two methods.

75 FR 62122 - Energy Conservation Program for Certain Industrial Equipment: Publication of the Petition for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-07

... rating the Altherma products in Europe. The test procedures are EN 14511 ``Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling'' and... rated according to European Standard EN 14511, ``Air conditioners, liquid chilling packages and heat...

10 CFR 431.62 - Definitions concerning commercial refrigerators, freezers and refrigerator-freezers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... measurements taken during the test. Lighting occupancy sensor means a device which uses passive infrared...) Operates at a chilled, frozen, combination chilled and frozen, or variable temperature; (4) Displays or... doors, or no doors; (6) Is designed for pull-down temperature applications or holding temperature...

9 CFR 327.21 - Inspection procedures for chilled fresh and frozen boneless manufacturing meat.

Code of Federal Regulations, 2010 CFR

2010-01-01

... fresh and frozen boneless manufacturing meat. 327.21 Section 327.21 Animals and Animal Products FOOD... MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION IMPORTED PRODUCTS § 327.21 Inspection procedures for chilled fresh and frozen boneless manufacturing meat. (a) Definitions...

9 CFR 327.21 - Inspection procedures for chilled fresh and frozen boneless manufacturing meat.

Code of Federal Regulations, 2011 CFR

2011-01-01

... fresh and frozen boneless manufacturing meat. 327.21 Section 327.21 Animals and Animal Products FOOD... MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION IMPORTED PRODUCTS § 327.21 Inspection procedures for chilled fresh and frozen boneless manufacturing meat. (a) Definitions...

Long-Term Cold Acclimation Extends Survival Time at 0°C and Modifies the Metabolomic Profiles of the Larvae of the Fruit Fly Drosophila melanogaster

PubMed Central

Koštál, Vladimír; Korbelová, Jaroslava; Rozsypal, Jan; Zahradníčková, Helena; Cimlová, Jana; Tomčala, Aleš; Šimek, Petr

2011-01-01

Background Drosophila melanogaster is a chill-susceptible insect. Previous studies on this fly focused on acute direct chilling injury during cold shock and showed that lower lethal temperature (LLT, approximately −5°C) exhibits relatively low plasticity and that acclimations, both rapid cold hardening (RCH) and long-term cold acclimation, shift the LLT by only a few degrees at the maximum. Principal Findings We found that long-term cold acclimation considerably improved cold tolerance in fully grown third-instar larvae of D. melanogaster. A comparison of the larvae acclimated at constant 25°C with those acclimated at constant 15°C followed by constant 6°C for 2 d (15°C→6°C) showed that long-term cold acclimation extended the lethal time for 50% of the population (Lt50) during exposure to constant 0°C as much as 630-fold (from 0.137 h to 86.658 h). Such marked physiological plasticity in Lt50 (in contrast to LLT) suggested that chronic indirect chilling injury at 0°C differs from that caused by cold shock. Long-term cold acclimation modified the metabolomic profiles of the larvae. Accumulations of proline (up to 17.7 mM) and trehalose (up to 36.5 mM) were the two most prominent responses. In addition, restructuring of the glycerophospholipid composition of biological membranes was observed. The relative proportion of glycerophosphoethanolamines (especially those with linoleic acid at the sn-2 position) increased at the expense of glycerophosphocholines. Conclusion Third-instar larvae of D. melanogaster improved their cold tolerance in response to long-term cold acclimation and showed metabolic potential for the accumulation of proline and trehalose and for membrane restructuring. PMID:21957472

Spall behavior of cast iron with varying microstructures

NASA Astrophysics Data System (ADS)

Plume, Gifford; Rousseau, Carl-Ernst

2014-07-01

The spall strength of cast iron with varying microstructures has been investigated using plate impact at moderate speed. Stress history measurements were made with manganin stress gauges embedded between the back face of the specimen and a low impedance polycarbonate backing. Five separate cast irons were tested. Four of these consisted of gray cast iron with graphite in flake form, with three classified as Type VII A2 and the fourth containing a bimodal distribution of Types VII A4 and VII D8. The fifth casting consisted of ductile cast iron with graphite in nodular form, classified as Type I, size class 5. The spall strength for the Type VII A2 gray cast irons varied between 40 and 370 MPa, and that of the additional gray cast iron, between 410 and 490 MPa. The spall strength of the ductile cast iron fell within the range of 0.94-1.2 GPa. It is shown that the spall strength is linked to the damage level at the spall plane, where an increased level of tensile stress is required to generate higher levels of damage. Post mortem analysis was performed on the recovered samples, revealing the graphite phase to be the primary factor governing the spall fracture of cast irons, where crack nucleation is directly correlated to the debonding of graphite from the metal matrix. The average length of graphite found within a casting is linked to the material's strength, where strength increases as a function of decreasing length. The morphology and mean free path of graphite precipitates further govern the subsequent coalescence of initiated cracks to form a complete fracture plane. In cases where graphite spacing is large, increased energy level is required to complete the fracture process. A secondary factor governing the spall fracture of cast irons has also been linked to the microstructure of the metal matrix, with pearlite yielding higher spall strengths than free ferrite.

Characterization of HEM silicon for solar cells. [Heat Exchanger Method

NASA Technical Reports Server (NTRS)

Dumas, K. A.; Khattak, C. P.; Schmid, F.

1981-01-01

The Heat Exchanger Method (HEM) is a promising low-cost ingot casting process for material used for solar cells. This is the only method that is capable of casting single crystal ingots with a square cross section using a directional solidification technique. This paper describes the chemical, mechanical and electrical properties of the HEM silicon material as a function of position within the ingot.

CAST-10-2/DOA 2 Airfoil Studies Workshop Results

NASA Technical Reports Server (NTRS)

Ray, Edward J. (Compiler); Hill, Acquilla S. (Compiler)

1989-01-01

During the period of September 23 through 27, 1988, the Transonic Aerodynamics Division at the Langely Research Center hosted an International Workshop on CAST-10-2/DOA 2 Airfoil Studies. The CAST-10 studies were the outgrowth of several cooperative study agreements among the NASA, the NAE of Canada, the DLR of West Germany, and the ONERA of France. Both theoretical and experimental CAST-10 airfoil results that were obtained form an extensive series of tests and studies, were reviewed. These results provided an opportunity to make direct comparisons of adaptive wall test section (AWTS) results from the NASA 0.3-meter Transonic Cryogenic Tunnel and ONERA T-2 AWTS facilities with conventional ventilated wall wind tunnel results from the Canadian high Reynolds number two-dimensional test facility. Individual papers presented during the workshop are included.

The application of multi-baseline digital close-range photogrammetry in three-dimensional imaging and measurement of dental casts

PubMed Central

Li, Zan; Liu, Shan; Tan, Minmin; Song, Jinlin

2017-01-01

Objective To explore a new technique for reconstructing and measuring three-dimensional (3D) models of orthodontic plaster casts using multi-baseline digital close-range photogrammetry (MBDCRP) with a single-lens reflex camera. Study design Thirty sets of orthodontic plaster casts that do not exhibit severe horizontal overlap (>2 mm) between any two teeth were recorded by a single-lens reflex camera with 72 pictures taken in different directions. The 3D models of these casts were reconstructed and measured using the open source software MeshLab. These parameters, including mesio-distal crown diameter, arch width, and arch perimeter, were recorded six times on both the 3D digital models and on plaster casts by two examiners. Statistical analysis was carried out using the Bland–Altman method to measure agreement between the novel method and the traditional calliper method by calculating the differences between mean values. Results The average differences between the measurements of the photogrammetric 3D models and the plaster casts were 0.011–0.402mm. The mean differences between measurements obtained by the photogrammetric 3D models and the dental casts were not significant except for the lower arch perimeter (P>0.05), and all the differences were regarded as clinically acceptable (<0.5 mm). Conclusions Measurements obtained by MBDCRP are compared well with those obtained from plaster casts, indicating that MBDCRP is an alternate way to store and measure dental plaster casts without severe horizontal overlap between any two teeth. PMID:28640827

Directly susceptible, noncarbon metal ceramic composite crucible

DOEpatents

Holcombe, Jr., Cressie E.; Kiggans, Jr., James O.; Morrow, S. Marvin; Rexford, Donald

1999-01-01

A sintered metal ceramic crucible suitable for high temperature induction melting of reactive metals without appreciable carbon or silicon contamination of the melt. The crucible comprises a cast matrix of a thermally conductive ceramic material; a perforated metal sleeve, which serves as a susceptor for induction heating of the crucible, embedded within the ceramic cast matrix; and a thermal-shock-absorber barrier interposed between the metal sleeve and the ceramic cast matrix to allow for differential thermal expansions between the matrix and the metal sleeve and to act as a thermal-shock-absorber which moderates the effects of rapid changes of sleeve temperature on the matrix.

Shock-to-detonation transition of RDX, HMX and NTO based composite high explosives: experiments and modelling

NASA Astrophysics Data System (ADS)

Baudin, G.; Roudot, M.; Genetier, M.; Mateille, P.; Lefrançois, A.

2014-05-01

HMX, RDX and NTO based cast-cured plastic bounded explosive (PBX) are widely used in insensitive ammunitions. Designing modern warheads needs robust and reliable models to compute shock ignition and detonation propagation inside PBX. Comparing to a pressed PBX, a cast-cured PBX is not porous and the hot-spots are mainly located at the grain-binder interface leading to a different burning behavior during shock-to-detonation transition. Here, we review the shock-to-detonation transition (SDT) and its modeling for cast-cured PBX containing HMX, RDX and NTO. Future direction is given in conclusion.