DKDP crystal growth controlled by cooling rate

Science.gov (United States)

Xie, Xiaoyi; Qi, Hongji; Shao, Jianda

2017-08-01

The performance of deuterated potassium dihydrogen phosphate (DKDP) crystal directly affects beam quality, energy and conversion efficiency in the Inertial Confinement Fusion（ICF）facility, which is related with the initial saturation temperature of solution and the real-time supersaturation during the crystal growth. However, traditional method to measure the saturation temperature is neither efficient nor accurate enough. Besides, the supersaturation is often controlled by experience, which yields the higher error and leads to the instability during the crystal growth. In this paper, DKDP solution with 78% deuteration concentration is crystallized in different temperatures. We study the relation between solubility and temperature of DKDP and fit a theoretical curve with a parabola model. With the model, the measurement of saturation temperature is simplified and the control precision of the cooling rate is improved during the crystal growth, which is beneficial for optimizing the crystal growth process.

Crystal agglomeration of europium oxalate in reaction crystallization using double-jet semi-batch reactor

International Nuclear Information System (INIS)

Kim, Woo-Sik; Kim, Woon-Soo; Kim, Kwang-Seok; Kim, Joon-Soo; Ward, Michael D.

2004-01-01

The particle agglomeration of europium oxalate was investigated in a double-jet semi-batch reactor over a wide range of operating variables, including the agitation speed, reactant feed rate, and reactant concentration. The size of the agglomerates was directly dictated by the particle collision and supersaturation promoting agglomeration and the fluid shear force inhibiting agglomeration. Thus, with a longer feeding time and higher feed concentration for the reaction crystallization, the mean particle size increased, while the corresponding total particle population decreased due to the enhanced chance of particle agglomeration, resulting from a longer residence time and higher supersaturation in the reactor. Agitation was found to exhibit a rather complicated influence on particle agglomeration. Although both particle collision and turbulent fluid shear were promoted by an increase in the mixing intensity, the crystal agglomeration of europium oxalate was maximized at around 500 rpm of agitation speed due to an optimized balance between particle aggregation and breakage

Composition dependence of spontaneous crystallization of phosphosilicate glass melts during cooling

DEFF Research Database (Denmark)

Liu, S.J.; Zhu, C.F.; Zhang, Y.F.

2012-01-01

Crystallization behavior of alumino-phospho-silicate melts during cooling is studied by means of the differential scanning calorimetry, X-ray diffractometry and viscometry. The results show a pronounced impact of alkaline earth oxide, alkali oxide and fluoride on the crystal type and crystallizat......Crystallization behavior of alumino-phospho-silicate melts during cooling is studied by means of the differential scanning calorimetry, X-ray diffractometry and viscometry. The results show a pronounced impact of alkaline earth oxide, alkali oxide and fluoride on the crystal type...... and crystallization degree. It is found that adding NaF into the studied compositions slightly decreases melt fragility and improves both the glass-forming ability and melt workability. This effect is associated with the unique structural role of NaF compared to the other modifier oxides. It is also found...

Effect of Cooling Rates on Shape and Crystal Size Distributions of Mefenamic Acid Polymorph in Ethyl Acetate

Science.gov (United States)

Mudalip, S. K. Abdul; Adam, F.; Parveen, J.; Abu Bakar, M. R.; Amran, N.; Sulaiman, S. Z.; Che Man, R.; Arshad, Z. I. Mohd; Shaarani, S. Md.

2017-06-01

This study investigate the effect of cooling rates on mefenamic acid crystallisation in ethyl acetate. The cooling rate was varied from 0.2 to 5 °C/min. The in-line conductivity system and turbidity system were employed to detect the onset of the crystallization process. The crystals produced were analysed using optical microscopy and Fourier transform infrared spectroscopy (FTIR). It was found that the crystals produced at different cooling rates were needle-like and exhibit polymorphic form type I. However, the aspect ratio and crystal size distributions were varied with the increased of cooling rate. A high crystals aspect ratio and narrower CSD (100-900 μm) was obtained at cooling rate of 0.5 °C/min. Thus, can be suggested as the most suitable cooling rate for crystallization of mefenamic acid in ethyl acetate.

Multi-dimensional population balance models of crystallization processes

DEFF Research Database (Denmark)

Meisler, Kresten Troelstrup; von Solms, Nicolas

A generic and model-based framework for batch cooling crystallization operations has been extended to incorporate continuous and fed-batch processes. Modules for the framework have been developed, including a module for reactions, allowing the study of reactive crystallization within the framework....... A kinetic model library together with an ontology for knowledge representation has been developed, in which kinetic models and relations from the literature are stored along with the references and data. The model library connects to the generic modelling framework as well, as models can be retrieved......, analyzed, used for simulation and stored again. The model library facilitates comparison of expressions for kinetic phenomena and is tightly integrated with the model analysis tools of the framework.Through the framework, a model for a crystallization operation may be systematically generated...

Investigation of the operating conditions to morphology evolution of β-L-glutamic acid during seeded cooling crystallization

Science.gov (United States)

Zhang, Fangkun; Liu, Tao; Huo, Yan; Guan, Runduo; Wang, Xue Z.

2017-07-01

In this paper the effects of operating conditions including cooling rate, initial supersaturation, and seeding temperature were investigated on the morphology evolution of β-L-glutamic acid (β-LGA) during seeded cooling crystallization. Based on the results of in-situ image acquisition of the crystal morphology evolution during the crystallization process, it was found that the crystal products tend to be plate-like or short rod-like under a slow cooling rate, low initial supersaturation, and low seeding temperature. In the opposite, the operating conditions of a faster cooling rate, higher initial supersaturation, and higher seeding temperature tend to produce long rod-like or needle-like crystals, and meanwhile, the length and width of crystal products will be increased together with a wider crystal size distribution (CSD). The aspect ratio of crystals, defined by the crystal length over width measured from in-situ or sample images, was taken as a shape index to analyze the crystal morphologies. Based on comparative analysis of the experimental results, guidelines on these operating conditions were given for obtaining the desired crystal shapes, along with the strategies for obtaining a narrower CSD for better product quality. Experimental verifications were performed to illustrate the proposed guidelines on the operating conditions for seeded cooling crystallization of LGA solution.

Choice of cooling regime of the superconducting magnetic system of the ''Crystal-2'' torsatron

International Nuclear Information System (INIS)

Glasov, B.V.; Druj, O.S.; Kurnosov, V.I.; Skibenko, E.I.; Yuferov, V.B.

1981-01-01

General requirements to a system of cryogenic cooling of superconducting magnetic systems (SMS) are formulated. Distributions of the value of thermal stresses about the temperature range are obtained for basic construction materials of SMS ''Crystal-2'' torsatron. Concrete circuits of SMS cryoprovision are considered. Values of specific and total heat capacity of the system, specific consumption of liquid are determined taking into consideration constructional peculiarities of SMS of''Crystal-2'' plant. Efficiency of different ways of SMS cooling are estimated, dynamical dependences of cooling and heating of SMS of the ''Crystal-2'' plant are obtained taking this into consideration [ru

Control of heat transfer in continuous-feeding Czochralski-silicon crystal growth with a water-cooled jacket

Science.gov (United States)

Zhao, Wenhan; Liu, Lijun

2017-01-01

The continuous-feeding Czochralski method is an effective method to reduce the cost of single crystal silicon. By promoting the crystal growth rate, the cost can be reduced further. However, more latent heat will be released at the melt-crystal interface under a high crystal growth rate. In this study, a water-cooled jacket was applied to enhance the heat transfer at the melt-crystal interface. Quasi-steady-state numerical calculation was employed to investigate the impact of the water-cooled jacket on the heat transfer at the melt-crystal interface. Latent heat released during the crystal growth process at the melt-crystal interface and absorbed during feedstock melting at the feeding zone was modeled in the simulations. The results show that, by using the water-cooled jacket, heat transfer in the growing crystal is enhanced significantly. Melt-crystal interface deflection and thermal stress increase simultaneously due to the increase of radial temperature at the melt-crystal interface. With a modified heat shield design, heat transfer at the melt-crystal interface is well controlled. The crystal growth rate can be increased by 20%.

Gas-liquid reactive crystallization kinetics of 2,4,6-triamino-1,3,5-trinitrobenzene in the semi-batch procedure

Science.gov (United States)

Liu, Ruqin; Huang, Ming; Yao, Xiaolu; Chen, Shuang; Wang, Shucun; Suo, Zhirong

2018-06-01

2,4,6-Triamino-1,3,5-trinitrobenzene is the attractive insensitive high energetic material used extensively in the military and civil fields. Combined with the double-films theory, the global gas-liquid chemical reaction kinetics of 2,4,6-triamino-1,3,5-trinitrobenzene was developed by means of the infinitesimal material balance calculation. The raw material concentration and reactive temperature effects on the crystallization of 2,4,6-triamino-1,3,5-trinitrobenzene were investigated by the batch experiments. The reactive crystallization kinetics associated ammonia feeding rate of 2,4,6-triamino-1,3,5-trinitrobenzene, including nucleation as well as crystal growth, was systematically investigated in the heterogonous semi-batch procedure. The nucleation and crystal growth kinetic exponents were estimated by the linear least-squares method. The crystallization kinetic results indicated that nucleation rate strongly increased but liner growth rate decreased with the increasing of ammonia feeding rate. In terms of manufacturing coarse 2,4,6-triamino-1,3,5-trinitrobenzene, it was found that a slow ammonia feeding rate and a low raw material concentration were feasible under the present experimental conditions.

Effect of cooling rate on crystallization in an aluminophosphosilicate melt

DEFF Research Database (Denmark)

Liu, S. J.; Zhang, Yanfei; Yue, Yuanzheng

2011-01-01

The effect of cooling rate on spontaneous crystallization behavior of an alumino-phospho-silicate melt is studied by means of differential scanning calorimetry, X-ray diffraction, scanning electron microscopy and viscometry. The cooling rates of 160, 2100 and 12000 K/s are attained by subjecting ......, the opalescence of the glass can be tuned by adjusting the cooling rate. This makes the production of opal glasses or transparent glass ceramics more efficient and energy saving, since the conventional isothermal treatment procedure can be left out....

Cryogenic cooling of x-ray crystals using porous matrix

International Nuclear Information System (INIS)

Kuzay, T.M.

1991-01-01

It is well established that Si and SiC have very desirable thermophysical properties at cryogenic temperatures. This feature makes cryo-cooled optics potentially a good candidate for the first optical crystal of the presently built third generation synchrotron machines with very high heat flux levels. Currently, there is a great deal of interest in such cryo-cooled crystals pursued both experimentally and analytically. The analytical studies involve cut micro or capillary channel crystals. As opposed to the machined channels, porous matrices provide significant advantages. They operate very quietly. Such matrices are known to affect superior heat transfer enhancement. Data available in open literature suggest that surface heat flux levels up to ∼8 kW/cm 2 are possible. For cryogens for which the boiling heat transfer heat flux is rather a low value in conventional geometries, the enhancement available with such matrices is a very significant characteristic. Cryogens are poor thermal conductors themselves. The fact that at the cryogenic temperatures the Si and/or SiC matrix itself becomes highly conductive, the matrix distributes the surface heat flux into the full volume effectively offsetting the poor conductivity of the coolant. In addition the tortuous path of the coolant through the matrix increases the dwell time for better heat transfer, however, at the expense of increased pressure drop. In this study, thermal conductivity of such composite matrices and the effective heat transfer coefficient obtainable using them are investigated. A first optics crystal model of Si with Si and/or Sic porous matrix as its heat exchanger and subject to prototype synchrotron level heat flux is analyzed and limits of the cooling possible with liquid nitrogen in single phase and subcooled boiling heat transfer modes are delineated

Transparent phosphosilicate glasses containing crystals formed during cooling of melts

DEFF Research Database (Denmark)

Liu, S. J.; Zhang, Yanfei; He, W.

2011-01-01

The effect of P2O5-SiO2 substitution on spontaneous crystallization of SiO2-Al2O3-P2O5- Na2O-MgO melts during cooling was studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and rotation viscometry. Results show that addition of P2O5 leads...... to amorphous phase separation (APS), i.e., phosphate- and silicate-rich phases. It is due to the tendency of Mg2+ to form [MgO4] linking with [SiO4]. Molar substitution of P2O5 for SiO2 enhances the network polymerization of silicate-rich phase in the melts, and thereby the spontaneous crystallization of cubic...... Na2MgSiO4 is also enhanced during cooling of the melts. In addition, the sizes of the local crystalline and separated glassy domains are smaller than the wavelength of the visible light, and this leads to the transparency of the obtained glasses containing crystals....

Time-resolved crystallization of deeply cooled liquid hydrogen isotopes

Energy Technology Data Exchange (ETDEWEB)

Kuehnel, Matthias

2014-02-15

This thesis serves two main purposes: 1. The introduction of a novel experimental method to investigate phase change dynamics of supercooled liquids 2. First-time measurements for the crystallization behaviour for hydrogen isotopes under various conditions (1) The new method is established by the synergy of a liquid microjet of ∼ 5 μm diameter and a scattering technique with high spatial resolution, here linear Raman spectroscopy. Due to the high directional stability and the known velocity of the liquid filament, its traveling axis corresponds to a time axis static in space. Utilizing evaporative cooling in a vacuum environment, the propagating liquid cools down rapidly and eventually experiences a phase transition to the crystalline state. This temporal evolution is probed along the filament axis, ultimately resulting in a time resolution of 10 ns. The feasibility of this approach is proven successfully within the following experiments. (2) A main object of study are para-hydrogen liquid filaments. Raman spectra reveal a temperature gradient of the liquid across the filament. This behaviour can quantitatively be reconstructed by numerical simulations using a layered model and is rooted in the effectiveness of evaporative cooling on the surface and a finite thermal conductivity. The deepest supercoolings achieved are ∼ 30% below the melting point, at which the filament starts to solidify from the surface towards the core. With a crystal growth velocity extracted from the data the appropriate growth mechanism is identified. The crystal structure that initially forms is metastable and probably the result of Ostwald's rule of stages. Indications for a transition within the solid towards the stable equilibrium phase support this interpretation. The analog isotope ortho-deuterium is evidenced to behave qualitatively similar with quantitative differences being mass related. In further measurements, isotopic mixtures of para-hydrogen and ortho-deuterium are

Time-resolved crystallization of deeply cooled liquid hydrogen isotopes

International Nuclear Information System (INIS)

Kuehnel, Matthias

2014-02-01

This thesis serves two main purposes: 1. The introduction of a novel experimental method to investigate phase change dynamics of supercooled liquids 2. First-time measurements for the crystallization behaviour for hydrogen isotopes under various conditions (1) The new method is established by the synergy of a liquid microjet of ∼ 5 μm diameter and a scattering technique with high spatial resolution, here linear Raman spectroscopy. Due to the high directional stability and the known velocity of the liquid filament, its traveling axis corresponds to a time axis static in space. Utilizing evaporative cooling in a vacuum environment, the propagating liquid cools down rapidly and eventually experiences a phase transition to the crystalline state. This temporal evolution is probed along the filament axis, ultimately resulting in a time resolution of 10 ns. The feasibility of this approach is proven successfully within the following experiments. (2) A main object of study are para-hydrogen liquid filaments. Raman spectra reveal a temperature gradient of the liquid across the filament. This behaviour can quantitatively be reconstructed by numerical simulations using a layered model and is rooted in the effectiveness of evaporative cooling on the surface and a finite thermal conductivity. The deepest supercoolings achieved are ∼ 30% below the melting point, at which the filament starts to solidify from the surface towards the core. With a crystal growth velocity extracted from the data the appropriate growth mechanism is identified. The crystal structure that initially forms is metastable and probably the result of Ostwald's rule of stages. Indications for a transition within the solid towards the stable equilibrium phase support this interpretation. The analog isotope ortho-deuterium is evidenced to behave qualitatively similar with quantitative differences being mass related. In further measurements, isotopic mixtures of para-hydrogen and ortho-deuterium are

Time-resolved crystallization of deeply cooled liquid hydrogen isotopes

Energy Technology Data Exchange (ETDEWEB)

Kuehnel, Matthias

2014-02-15

This thesis serves two main purposes: 1. The introduction of a novel experimental method to investigate phase change dynamics of supercooled liquids 2. First-time measurements for the crystallization behaviour for hydrogen isotopes under various conditions (1) The new method is established by the synergy of a liquid microjet of ∼ 5 μm diameter and a scattering technique with high spatial resolution, here linear Raman spectroscopy. Due to the high directional stability and the known velocity of the liquid filament, its traveling axis corresponds to a time axis static in space. Utilizing evaporative cooling in a vacuum environment, the propagating liquid cools down rapidly and eventually experiences a phase transition to the crystalline state. This temporal evolution is probed along the filament axis, ultimately resulting in a time resolution of 10 ns. The feasibility of this approach is proven successfully within the following experiments. (2) A main object of study are para-hydrogen liquid filaments. Raman spectra reveal a temperature gradient of the liquid across the filament. This behaviour can quantitatively be reconstructed by numerical simulations using a layered model and is rooted in the effectiveness of evaporative cooling on the surface and a finite thermal conductivity. The deepest supercoolings achieved are ∼ 30% below the melting point, at which the filament starts to solidify from the surface towards the core. With a crystal growth velocity extracted from the data the appropriate growth mechanism is identified. The crystal structure that initially forms is metastable and probably the result of Ostwald's rule of stages. Indications for a transition within the solid towards the stable equilibrium phase support this interpretation. The analog isotope ortho-deuterium is evidenced to behave qualitatively similar with quantitative differences being mass related. In further measurements, isotopic mixtures of para-hydrogen and ortho-deuterium are

The hardness of synthetic products obtained from cooled and crystallized basaltic melts (in Romanian)

OpenAIRE

Daniela Ogrean

2001-01-01

The Hardness of Synthetic Products Obtained from Cooled and Crystallized Basaltic Melts. Hardness is one of the main properties of the products obtained from cooled and crystallized basaltic melts under a controlled thermal regime. It influences the abrasion tear resistance of the resulted material. The microhardness measurements on the samples (bricks, boards, gutters, armour plates, tubes) indicated Vickers hardness value between 757–926 for the materials obtained from Şanovita basalts (Tim...

Applications of thin-film sandwich crystallization platforms

Energy Technology Data Exchange (ETDEWEB)

Axford, Danny, E-mail: danny.axford@diamond.ac.uk; Aller, Pierre; Sanchez-Weatherby, Juan; Sandy, James [Diamond Light Source, Harwell Oxford, Didcot OX11 0DE (United Kingdom)

2016-03-24

Crystallization via sandwiches of thin polymer films is presented and discussed. Examples are shown of protein crystallization in, and data collection from, solutions sandwiched between thin polymer films using vapour-diffusion and batch methods. The crystallization platform is optimal for both visualization and in situ data collection, with the need for traditional harvesting being eliminated. In wells constructed from the thinnest plastic and with a minimum of aqueous liquid, flash-cooling to 100 K is possible without significant ice formation and without any degradation in crystal quality. The approach is simple; it utilizes low-cost consumables but yields high-quality data with minimal sample intervention and, with the very low levels of background X-ray scatter that are observed, is optimal for microcrystals.

Liquid-metal-cooled, curved-crystal monochromator for Advanced Photon Source bending-magnet beamline 1-BM

International Nuclear Information System (INIS)

Brauer, S.; Rodricks, B.; Assoufid, L.; Beno, M.A.; Knapp, G.S.

1996-06-01

The authors describe a horizontally focusing curved-crystal monochromator that invokes a 4-point bending scheme and a liquid-metal cooling bath. The device has been designed for dispersive diffraction and spectroscopy in the 5--20 keV range, with a predicted focal spot size of ≤ 100 microm. To minimize thermal distortions and thermal equilibration time, the 355 x 32 x 0.8 mm crystal will be nearly half submerged in a bath of Ga-In-Sn-Zn alloy. The liquid metal thermally couples the crystal to the water-cooled Cu frame, while permitting the required crystal bending. Calculated thermal profiles and anticipated focusing properties are discussed

Design of a cryo-cooled artificial channel-cut crystal monochromator for the European XFEL

Energy Technology Data Exchange (ETDEWEB)

Dong, Xiaohao, E-mail: xiaohao.dong@xfel.eu; Sinn, Harald, E-mail: harald.sinn@xfel.eu [European XFEL GmbH, Hamburg, D-22761 (Germany); Shu, Deming, E-mail: shu@aps.anl.gov [Argonne National Laboratory, Argonne, IL 60439, U.S.A (United States)

2016-07-27

An artificial channel-cut crystal monochromator for the hard X-Ray beamlines of SASE 1&2, cryogenically cooled by the so-called pulse tube cooler (cryorefrigerator), is currently under development at the European XFEL ( http://www.xfel.eu/ ). The fabrication is on-going. We present here the crystal optical consideration and the novel cooling configuration, according to the X-Ray FEL pulses proprieties. The mechanical design improvements are pointed out as well to implement such kind of monochromator based on the previous similar design.

Incorporation of cooling-induced crystallization into a 2-dimensional axisymmetric conduit heat flow model

Science.gov (United States)

Heptinstall, David; Bouvet de Maisonneuve, Caroline; Neuberg, Jurgen; Taisne, Benoit; Collinson, Amy

2016-04-01

Heat flow models can bring new insights into the thermal and rheological evolution of volcanic 3 systems. We shall investigate the thermal processes and timescales in a crystallizing, static 4 magma column, with a heat flow model of Soufriere Hills Volcano (SHV), Montserrat. The latent heat of crystallization is initially computed with MELTS, as a function of pressure and temperature for an andesitic melt (SHV groundmass starting composition). Three fractional crystallization simulations are performed; two with initial pressures of 34MPa (runs 1 & 2) and one of 25MPa (run 3). Decompression rate was varied between 0.1MPa/° C (runs 1 & 3) and 0.2MPa/° C (run 2). Natural and experimental matrix glass compositions are accurately reproduced by all MELTS runs. The cumulative latent heat released for runs 1, 2 and 3 differs by less than 9% (8.69E5 J/kg*K, 9.32E5 J/kg*K, and 9.49E5 J/kg*K respectively). The 2D axisymmetric conductive cooling simulations consider a 30m-diameter conduit that extends from the surface to a depth of 1500m (34MPa). The temporal evolution of temperature is closely tracked at depths of 10m, 750m and 1400m in the centre of the conduit, at the conduit walls, and 20m from the walls into the host rock. Following initial cooling by 7-15oC at 10m depth inside the conduit, the magma temperature rebounds through latent heat release by 32-35oC over 85-123 days to a maximum temperature of 1002-1005oC. At 10m depth, it takes 4.1-9.2 years for the magma column to cool by 108-131oC and crystallize to 75wt%, at which point it cannot be easily remobilized. It takes 11-31.5 years to reach the same crystallinity at 750-1400m depth. We find a wide range in cooling timescales, particularly at depths of 750m or greater, attributed to the initial run pressure and the dominant latent heat producing crystallizing phase, Albite-rich Plagioclase Feldspar. Run 1 is shown to cool fastest and run 3 cool the slowest, with surface emissivity having the strongest cooling

Study on the impact of transition from 3-batch to 4-batch loading at Loviisa NPP on the long-term decay heat and activity inventory

Energy Technology Data Exchange (ETDEWEB)

Lahtinen, Tuukka [Fortum Power and Heat Ltd., Fortum (Finland)

2017-09-15

The fuel economy of Loviisa NPP was improved by implementing a transition from 3-batch to 4-batch loading scheme between 2009 and 2013. Equilibrium cycle length as well as all process parameters were retained unchanged while the increase of fuel enrichment enabled to reduce the annual reload batch size from 102 to 84 assemblies. The fuel cycle transition obviously had an effect on the long-term decay heat and activity inventory. However, due to simultaneous change in several quantities the net effect over the relevant cooling time region is not self-evident. In this study the effect is analyzed properly, i. e. applying consistent calculation models and detailed description of assembly-wise irradiation histories. The study concludes that for the cooling time, foreseen typical prior to encapsulation of assemblies, the decay heat of discharge batch increases 2 - 3%. It is also concluded that, in order to maintain 100% filling degree of final disposal canisters, the cooling time prior to encapsulation needs to be prolonged by 10 - 15 years.

Design of an adaptive cooled first crystal for an X-ray monochromator

International Nuclear Information System (INIS)

Dezoret, D.; Marmoret, R.; Freund, A.K.; Kvick, AA.; Ravelet, R.

1994-01-01

We report here on the design of the first crystal in an x-ray monochromator for E.S.R.F. beam lines. This crystal is a thin silicon foil bonded to a cooled beryllium support. A system of piezoelectric actuators is used to counterbalance the deformations induced by synchrotron beams. This work was carried out by the C.E.A. in collaboration with the E.S.R.F. and the LASERDOT Company (Aerospatiale Group). (orig.)

The hardness of synthetic products obtained from cooled and crystallized basaltic melts (in Romanian

Directory of Open Access Journals (Sweden)

Daniela Ogrean

2001-04-01

Full Text Available The Hardness of Synthetic Products Obtained from Cooled and Crystallized Basaltic Melts. Hardness is one of the main properties of the products obtained from cooled and crystallized basaltic melts under a controlled thermal regime. It influences the abrasion tear resistance of the resulted material. The microhardness measurements on the samples (bricks, boards, gutters, armour plates, tubes indicated Vickers hardness value between 757–926 for the materials obtained from Şanovita basalts (Timiş district and between 539–958 respectively, in case of the Racoş basalts (Braşov district. There is a certain variation of the hardness within the same sample, in various measurement points, within the theoretical limits of the hardnesses of the pyroxenes and that of the spinels.

Stacking with stochastic cooling

Energy Technology Data Exchange (ETDEWEB)

Caspers, Fritz E-mail: Fritz.Caspers@cern.ch; Moehl, Dieter

2004-10-11

Accumulation of large stacks of antiprotons or ions with the aid of stochastic cooling is more delicate than cooling a constant intensity beam. Basically the difficulty stems from the fact that the optimized gain and the cooling rate are inversely proportional to the number of particles 'seen' by the cooling system. Therefore, to maintain fast stacking, the newly injected batch has to be strongly 'protected' from the Schottky noise of the stack. Vice versa the stack has to be efficiently 'shielded' against the high gain cooling system for the injected beam. In the antiproton accumulators with stacking ratios up to 10{sup 5} the problem is solved by radial separation of the injection and the stack orbits in a region of large dispersion. An array of several tapered cooling systems with a matched gain profile provides a continuous particle flux towards the high-density stack core. Shielding of the different systems from each other is obtained both through the spatial separation and via the revolution frequencies (filters). In the 'old AA', where the antiproton collection and stacking was done in one single ring, the injected beam was further shielded during cooling by means of a movable shutter. The complexity of these systems is very high. For more modest stacking ratios, one might use azimuthal rather than radial separation of stack and injected beam. Schematically half of the circumference would be used to accept and cool new beam and the remainder to house the stack. Fast gating is then required between the high gain cooling of the injected beam and the low gain stack cooling. RF-gymnastics are used to merge the pre-cooled batch with the stack, to re-create free space for the next injection, and to capture the new batch. This scheme is less demanding for the storage ring lattice, but at the expense of some reduction in stacking rate. The talk reviews the 'radial' separation schemes and also gives some

Cooling and heating of the ion flux on the transmission through crystals

International Nuclear Information System (INIS)

Karamyan, S.A.; Gruener, F.; Assmann, W.

2003-01-01

Transmission of charged particles through a monocrystalline medium is accompanied by many interesting phenomena, and a new one - redistribution of the isotropic flux - is now studied experimentally and described. The cooling or heating in the transverse momentum coordinate arises as a result of crystal-induced modification of the transmission trajectories. This indicates the violation of the reversibility rule, and cannot be explained within prevailing theory of channeling. The type of image (enhancement or reduction) and its intensity are dependent on the ion and crystal species, on the energy of ions and on the crystal thickness. Such dependencies have been studied experimentally and the mechanism involving the regular sequence of charge-exchange events with the transverse-energy non-conservation is attracted for understanding. The crystal response to ion flux transmission is also reviewed and characterized by the original results

The effect factors of potassium dihydrogen phosphate crystallization in aqueous solution

Science.gov (United States)

Zhou, Cun; Sun, Fei; Liu, Xuzhao

2017-01-01

The effects of cooling rate and pH on the potassium dihydrogen phosphate crystallization process were studied by means of batch crystallization process. The experiment shows that with the increase of cooling rate, the metastable zone width increase and the induction period decrease. When the pH is 3.0, the metastable zone width and induction period are both the minimum, while the crystallization rate is the highest. The crystallization products were characterized by scanning election microscope. Potassium Dihydrogen Phosphate (KDP) is a kind of excellent nonlinear optical materials, and belongs to tetragonal system, and ideal shape is aggregate of tetragonal prism and tetragonal dipyramid, the (100) cone is alternating accumulation by double positive ions and double negative ions [1-4]. The crystals of aqueous solution method to grow have large electro-optical nonlinear coefficient and high loser-damaged threshold, and it is the only nonlinear optical crystal could be used in inertial confinement fusion (ICF), KDP crystals are the ideal system to study the native defects of complex oxide insulating material [5-7]. With the development of photovoltaic technology, KDP crystals growth and performance have become a research focus worldwide [8, 9]. The merits of the crystallization process directly affect the quality of KDP products, so the study of the effect of crystallization conditions has an important significance on industrial production. This paper studied the change rule of metastable zone width, induction period, crystallization rate and particle size distribution in crystal process, and discussed the technical condition of KDP crystallization.

Progressing batch hydrolysis process

Science.gov (United States)

Wright, J.D.

1985-01-10

A progressive batch hydrolysis process is disclosed for producing sugar from a lignocellulosic feedstock. It comprises passing a stream of dilute acid serially through a plurality of percolation hydrolysis reactors charged with feed stock, at a flow rate, temperature and pressure sufficient to substantially convert all the cellulose component of the feed stock to glucose. The cooled dilute acid stream containing glucose, after exiting the last percolation hydrolysis reactor, serially fed through a plurality of pre-hydrolysis percolation reactors, charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the hemicellulose component of said feedstock to glucose. The dilute acid stream containing glucose is cooled after it exits the last prehydrolysis reactor.

Systematic Modelling and Crystal Size Distribution Control for Batch Crystallization Processes

DEFF Research Database (Denmark)

Abdul Samad, Noor Asma Fazli; Singh, Ravendra; Sin, Gürkan

Crystallization processes form an important class of separation methods that are frequently used in the chemical, the pharmaceutical and the food industry. The specifications of the crystal product are usually given in terms of crystal size, shape and purity. In order to predict the desired cryst...

Parallel Solution of Robust Nonlinear Model Predictive Control Problems in Batch Crystallization

Directory of Open Access Journals (Sweden)

Yankai Cao

2016-06-01

Full Text Available Representing the uncertainties with a set of scenarios, the optimization problem resulting from a robust nonlinear model predictive control (NMPC strategy at each sampling instance can be viewed as a large-scale stochastic program. This paper solves these optimization problems using the parallel Schur complement method developed to solve stochastic programs on distributed and shared memory machines. The control strategy is illustrated with a case study of a multidimensional unseeded batch crystallization process. For this application, a robust NMPC based on min–max optimization guarantees satisfaction of all state and input constraints for a set of uncertainty realizations, and also provides better robust performance compared with open-loop optimal control, nominal NMPC, and robust NMPC minimizing the expected performance at each sampling instance. The performance of robust NMPC can be improved by generating optimization scenarios using Bayesian inference. With the efficient parallel solver, the solution time of one optimization problem is reduced from 6.7 min to 0.5 min, allowing for real-time application.

Resistive cooling circuits for charged particle traps using crystal resonators

CERN Document Server

Kaltenbacher, T; Doser, M; Kellerbauer, A; Pribyl, W

2011-01-01

The paper addresses a novel method to couple a signal from charged particles in a Penning trap to a high Q resonant circuit using a crystal resonator. Traditionally the trap capacity is converted into a resonator by means of an inductance. When normal conducting wires (e.g. copper) are applied to build up a coil, the unloaded Q value is limited to a value in the order of 1000. The tuned circuit’s Q factor is directly linked to the input impedance “seen” by the trapped particles at resonance frequency. This parallel resonance impedance is a measure of the efficiency of resistive cooling and thus it should be optimized. We propose here a commercially available crystal resonator since it exhibits a very high Q value and a parallel resonance impedance of several MOhm. The possibility to tune the parallel resonance frequency of the quartz results in filter behavior that allows covering a broad range of frequencies.

Nucleation control and separation of paracetamol polymorphs through swift cooling crystallization process

Science.gov (United States)

Sudha, C.; Srinivasan, K.

2014-09-01

Polymorphic nucleation behavior of pharmaceutical solid paracetamol has been investigated by performing swift cooling crystallization process. Saturated aqueous solution prepared at 318 K was swiftly cooled to 274 K in steps of every 1 K in the temperature range from 274 K to 313 K with uniform stirring of 100 rpm. The resultant supersaturation generated in the mother solution favours the nucleation of three different polymorphs of paracetamol. Lower supersaturation region σ=0.10-0.83 favours stable mono form I; the intermediate supersaturation region σ=0.92-1.28 favours metastable ortho form II and the higher supersaturation region σ=1.33-1.58 favours unstable form III polymorphic nucleation. Depending upon the level of supersaturation generated during swift cooling process and the corresponding solubility limit and metastable zone width (MSZW) of each polymorph, the nucleation of a particular polymorph occurs in the system. The type of polymorphs was identified by in-situ optical microscopy and the internal structure was confirmed by Powder X-ray diffraction (PXRD) study. By this novel approach, the preferred nucleation regions of all the three polymorphs of paracetamol are optimized in terms of different cooling ranges employed during the swift cooling process. Also solution mediated polymorphic transformations from unstable to mono and ortho to mono polymorphs have been studied by in-situ.

Batch crystallization of rifapentine for inhalable tuberculosis medication

Science.gov (United States)

Wijanarko, Anondho; Meivita, Maria Prisca; Hermansyah, Heri; Sahlan, Muhamad; Lakerveld, Richard

2018-02-01

In the midst of Tuberculosis (TB) pandemic, a research about new tuberculosis drug that results in more rapid resolution of tubercular infection is important. It will play a crucial role in accelerating the reductions in tuberculosis incidence that is occurring worldwide. The effectiveness of rifapentine has been assessed and it has been proven to be the most effective antibiotics for TB. A frequent administration and dose of rifapentine resulted in more rapid resolution of tubercular infection. However, based on former research, high exposure levels for treatment shortening may be unachievable with oral administration and might instead be achieved by direct aerosol delivery of rifapentine to the pulmonary site of infection. Therefore, with the growing interest in the effectiveness of rifapentine in frequent administration and dose, this research integrates an inhalable form of crystalline rifapentine prepared using a batch process. Moreover, this research investigates the effect of seed loading, supersaturation ratio, and residence time on the characterization of crystalline rifapentine in order to form a crystalline rifapentine in an inhalable size. The research was carried out by using anti-solvent crystallization method with acetone as a solvent and distilled water as an anti-solvent. Based on the assessment of various operating variables, it can be concluded that the optimum result was obtained at the unseeded experiment with supersaturation ratio = 1.26. Unseeded experiments are preferred because the ideal size for therapeutic aerosol was achieved in unseeded experiments. At the request of all authors the above article is being retracted due to publication without knowledge or consent from one of the principal investigators of the research listed on the article, Dr. Richard Lakerveld. This article is retracted from the scientific record with effect from 18 May 2018.

Laser-cooled atoms inside a hollow-core photonic-crystal fiber

DEFF Research Database (Denmark)

Bajcsy, Michal; Hofferberth, S.; Peyronel, Thibault

2011-01-01

We describe the loading of laser-cooled rubidium atoms into a single-mode hollow-core photonic-crystal fiber. Inside the fiber, the atoms are confined by a far-detuned optical trap and probed by a weak resonant beam. We describe different loading methods and compare their trade-offs in terms...... of implementation complexity and atom-loading efficiency. The most efficient procedure results in loading of ∼30,000 rubidium atoms, which creates a medium with an optical depth of ∼180 inside the fiber. Compared to our earlier study this represents a sixfold increase in the maximum achieved optical depth...

Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems.

Science.gov (United States)

Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron

2009-01-01

The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems.

Effect of titanium dioxide (TiO2) on largely improving solar reflectance and cooling property of high density polyethylene (HDPE) by influencing its crystallization behavior

International Nuclear Information System (INIS)

Wang, Shichao; Zhang, Jun

2014-01-01

Highlights: • HDPE/TiO 2 composites have more perfect crystal structure. • Refractive index is the key factor affecting the final solar reflectance. • HDPE/TiO 2 composites can achieve high solar reflectance. • The real cooling property is in accordance with solar reflectance. - Abstract: In this study, the different crystal forms of titanium dioxide (TiO 2 ) were added into high density polyethylene (HDPE) to fabricate cool material. Crystal structure, crystallization behavior, crystal morphology were investigated by wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarized optical microscope (POM). Scanning electron microscope (SEM) was applied to observe dispersion of TiO 2 particles in the HDPE matrix and the cross section morphology. The solar reflectance and actual cooling property were evaluated by UV–Vis–NIR spectrometer and a self-designed device. By adding TiO 2 particles into HDPE matrix, the polymer chain could crystallize into more perfect and thermal stable lamella. The presence of TiO 2 particles dramatically increased the number of nucleation site therefore decreased the crystal size. The subsequent solar reflectance was related to the degree of crystallinity, the spherulite size of HDPE, refractive index, and distribution of TiO 2 particles in HDPE matrix. It was found the rutile TiO 2 could largely improve the total solar reflectance from 28.2% to 51.1%. Finally, the temperature test showed that the composites had excellent cooling property, which was in accordance with solar reflectance result

Ultrasound Assisted Particle Size Control by Continuous Seed Generation and Batch Growth

OpenAIRE

Jordens, Jeroen; Canini, Enio; Gielen, Bjorn; Van Gerven, Tom; Braeken, Leen

2017-01-01

Controlling particle size is essential for crystal quality in the chemical and pharmaceutical industry. Several articles illustrate the potential of ultrasound to tune this particle size during the crystallization process. This paper investigates how ultrasound can control the particle size distribution (PSD) of acetaminophen crystals by continuous seed generation in a tubular crystallizer followed by batch growth. It is demonstrated that the supersaturation ratio at which ultrasound starts s...

Batch and continuous (fixed-bed column) biosorption of crystal violet by Artocarpus heterophyllus (jackfruit) leaf powder.

Science.gov (United States)

Saha, Papita Das; Chakraborty, Sagnik; Chowdhury, Shamik

2012-04-01

In this study, batch and fixed-bed column experiments were performed to investigate the biosorption potential of Artocarpus heterophyllus (jackfruit) leaf powder (JLP) to remove crystal violet (CV) from aqueous solutions. Batch biosorption studies were carried out as a function of solution pH, contact time, initial dye concentration and temperature. The biosorption equilibrium data showed excellent fit to the Langmuir isotherm model with maximum monolayer biosorption capacity of 43.39 mg g(-1) at pH 7.0, initial dye concentration=50 mg L(-1), temperature=293 K and contact time=120 min. According to Dubinin-Radushkevich (D-R) isotherm model, biosorption of CV by JLP was chemisorption. The biosorption kinetics followed the pseudo-second-order kinetic model. Thermodynamic analysis revealed that biosorption of CV from aqueous solution by JLP was a spontaneous and exothermic process. In order to ascertain the practical applicability of the biosorbent, fixed-bed column studies were also performed. The breakthrough time increased with increasing bed height and decreased with increasing flow rate. The Thomas model as well as the BDST model showed good agreement with the experimental results at all the process parameters studied. It can be concluded that JLP is a promising biosorbent for removal of CV from aqueous solutions. Copyright © 2011 Elsevier B.V. All rights reserved.

Melt extraction during heating and cooling of felsic crystal mushes in shallow volcanic systems: An experimental study

Science.gov (United States)

Pistone, M.; Baumgartner, L. P.; Sisson, T. W.; Bloch, E. M.

2017-12-01

The dynamics and kinetics of melt extraction in near-solidus, rheologically stalled, felsic crystal mushes (> 50 vol.% crystals) are essential to feeding many volcanic eruptions. At shallow depths (volatile-saturated and may be thermally stable for long time periods (104-107 years). In absence of deformation, residual melt can segregate from the mush's crystalline framework stimulated by: 1) gas injecting from hot mafic magmas into felsic mushes (heating / partial melting scenario), and 2) gas exsolving from the crystallizing mush (cooling / crystallizing scenario). The conditions and efficiency of melt extraction from a mush in the two scenarios are not well understood. Thus, we conducted high-temperature (700 to 850 °C) and -pressure (1.1 kbar) cold seal experiments (8-day duration) on synthetic felsic mushes, composed of water-saturated (4.2 wt.%) rhyodacite melt bearing different proportions of added quartz crystals (60, 70, and 80 vol%; 68 mm average particle size). High-spatial resolution X-ray tomography of run products show: 1) in the heating scenario (> 750 °C) melt has not segregated due to coalescence of vesicles (≤ 23 vol%) and large melt connectivity (> 7 vol% glass) / low pressure gradient for melt movement up to 80 vol% crystals; 2) in the cooling scenario (≤ 750 °C) vesicle (< 11 vol%) coalescence is limited or absent and limited amount of melt (3 to 11 vol%) segregated from sample center to its outer periphery (30 to 100 mm melt-rich lenses), testifying to the efficiency of melt extraction dictated by increasing crystallinity. These results suggest that silicic melt hosted within a crystal-rich mush can accumulate rapidly due to the buildup of modest gas pressures during crystallization at temperatures near the solidus.

Batch cooling crystallization and pressure filtration of sulphathiazole

DEFF Research Database (Denmark)

Häkkinen, Antti; Pöllänen, Kati; Karjalainen, Milja

2005-01-01

Currently there is a great interest in new process analytical approaches to increase the process understanding of pharmaceutical unit operations. In the present study, the influence of the solvent composition on the material properties and, further, on the filtration characteristics, of different...

Reduction of Langelier index of cooling water by electrolytic ...

African Journals Online (AJOL)

LSI) of the cooling water from a cooling tower of a textile industry was investigated. Sacrificial anodes were employed which prevent obnoxious chlorine generation. A series of batch experiments using stainless steel electrodes were conducted ...

Cryogenic cooling of x-ray crystals using a porous matrix

International Nuclear Information System (INIS)

Kuzay, T.M.

1992-01-01

It is well established that Si and SiC have very desirable thermophysical properties (principally, high thermal conductivity, and low thermal expansion) at cryogenic temperatures. Thus, cryocooled optics are a potentially good candidate for the first optical crystal of the third generation synchrotron machines, which will have very high heat flux levels. Currently, there is a great deal of interest, both experimental and analytical in such cryocooled crystals. The analytical studies involve cut micro- or capillary channel crystals. As opposed to machined channels, porous matrices provide significant advantages. Such matrices are known to effect superior heat transfer. They operate very quietly. Data available in the open literature suggest that surface heat flux levels up to ∼8 kW/cm 2 are possible. For cryogens for which the boiling heat transfer heat flux is a rather low value in conventional geometries, the enhancement available with such matrices is very significant. Cryogens are poor thermal conductors themselves. At cryogenic temperatures, the Si and/or SiC matrix itself becomes highly conductive: Thus, the matrix distributes the surface heat flux into the full volume effectively offsetting the poor conductivity of the coolant. In addition, the tortuous path of the coolant through the matrix increases the dwell time resulting in better heat transfer, however, at the expense of an increased pressure drop. In this study, a first optics crystal model of Si with a Si and/or SiC porous matrix as its heat exchanger and subject to prototypic synchrotron loads is analyzed, and the feasibility limits of the cooling possible with liquid nitrogen in single phase are delineated

CRC DEPLETION CALCULATIONS FOR THE NON-RODDED ASSEMBLIES IN BATCHES 8 AND 9 CRYSTAL RIVER UNIT 3

International Nuclear Information System (INIS)

Wilson, Michael L.

2001-01-01

The purpose of this design analysis is to document the SAS2H depletion calculations of certain non-rodded fuel assemblies from batches 8 and 9 of the Crystal River Unit 3 pressurized water reactor (PWR) that are required for Commercial Reactor Critical (CRC) evaluations to support the development of the disposal criticality methodology. A non-rodded assembly is one which never contains a control rod assembly (CRA) or an axial power shaping rod assembly (APSRA) during its irradiation history. The objective of this analysis is to provide SAS2H generated isotopic compositions for each fuel assembly's depleted fuel and depleted burnable poison materials. These SAS2H generated isotopic compositions are acceptable for use in CRC benchmark reactivity calculations containing the various fuel assemblies

Effect of titanium dioxide (TiO{sub 2}) on largely improving solar reflectance and cooling property of high density polyethylene (HDPE) by influencing its crystallization behavior

Energy Technology Data Exchange (ETDEWEB)

Wang, Shichao; Zhang, Jun, E-mail: zhangjun@njtech.edu.cn

2014-12-25

Highlights: • HDPE/TiO{sub 2} composites have more perfect crystal structure. • Refractive index is the key factor affecting the final solar reflectance. • HDPE/TiO{sub 2} composites can achieve high solar reflectance. • The real cooling property is in accordance with solar reflectance. - Abstract: In this study, the different crystal forms of titanium dioxide (TiO{sub 2}) were added into high density polyethylene (HDPE) to fabricate cool material. Crystal structure, crystallization behavior, crystal morphology were investigated by wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarized optical microscope (POM). Scanning electron microscope (SEM) was applied to observe dispersion of TiO{sub 2} particles in the HDPE matrix and the cross section morphology. The solar reflectance and actual cooling property were evaluated by UV–Vis–NIR spectrometer and a self-designed device. By adding TiO{sub 2} particles into HDPE matrix, the polymer chain could crystallize into more perfect and thermal stable lamella. The presence of TiO{sub 2} particles dramatically increased the number of nucleation site therefore decreased the crystal size. The subsequent solar reflectance was related to the degree of crystallinity, the spherulite size of HDPE, refractive index, and distribution of TiO{sub 2} particles in HDPE matrix. It was found the rutile TiO{sub 2} could largely improve the total solar reflectance from 28.2% to 51.1%. Finally, the temperature test showed that the composites had excellent cooling property, which was in accordance with solar reflectance result.

Multi-scale simulation of single crystal hollow turbine blade manufactured by liquid metal cooling process

Directory of Open Access Journals (Sweden)

Xuewei Yan

2018-02-01

Full Text Available Liquid metal cooling (LMC process as a powerful directional solidification (DS technique is prospectively used to manufacture single crystal (SC turbine blades. An understanding of the temperature distribution and microstructure evolution in LMC process is required in order to improve the properties of the blades. For this reason, a multi-scale model coupling with the temperature field, grain growth and solute diffusion was established. The temperature distribution and mushy zone evolution of the hollow blade was simulated and discussed. According to the simulation results, the mushy zone might be convex and ahead of the ceramic beads at a lower withdrawal rate, while it will be concave and laggard at a higher withdrawal rate, and a uniform and horizontal mushy zone will be formed at a medium withdrawal rate. Grain growth of the blade at different withdrawal rates was also investigated. Single crystal structures were all selected out at three different withdrawal rates. Moreover, mis-orientation of the grains at 8 mm/min reached ~30°, while it was ~5° and ~15° at 10 mm/min and 12 mm/min, respectively. The model for predicting dendritic morphology was verified by corresponding experiment. Large scale for 2D dendritic distribution in the whole sections was investigated by experiment and simulation, and they presented a well agreement with each other. Keywords: Hollow blade, Single crystal, Multi-scale simulation, Liquid metal cooling

CRC DEPLETION CALCULATIONS FOR THE NON-RODDED ASSEMBLIES IN BATCHES 4 AND 5 OF CRYSTAL RIVER UNIT 3

International Nuclear Information System (INIS)

Wright, Kenneth D.

1997-01-01

The purpose of this design analysis is to document the SAS2H depletion calculations of certain non-rodded fuel assemblies from batches 4 and 5 of the Crystal River Unit 3 pressurized water reactor (PWR) that are required for commercial Reactor Critical (CRC) evaluations to support the development of the disposal criticality methodology. A non-rodded assembly is one which never contains a control rod assembly (CRA) or an axial power shaping rod assembly (APSRA) during its irradiation history. The objective of this analysis is to provide SAS2H generated isotopic compositions for each fuel assembly's depleted fuel and depleted burnable poison materials. These SAS2H generated isotopic compositions are acceptable for use in CRC benchmark reactivity calculations containing the various fuel assemblies

Methodology of Supervision by Analysis of Thermal Flux for Thermal Conduction of a Batch Chemical Reactor Equipped with a Monofluid Heating/Cooling System

Directory of Open Access Journals (Sweden)

Ghania Henini

2012-01-01

Full Text Available We present the thermal behavior of a batch reactor to jacket equipped with a monofluid heating/cooling system. Heating and cooling are provided respectively by an electrical resistance and two plate heat exchangers. The control of the temperature of the reaction is based on the supervision system. This strategy of management of the thermal devices is based on the usage of the thermal flux as manipulated variable. The modulation of the monofluid temperature by acting on the heating power or on the opening degrees of an air-to-open valve that delivers the monofluid to heat exchanger. The study shows that the application of this method for the conduct of the pilot reactor gives good results in simulation and that taking into account the dynamics of the various apparatuses greatly improves ride quality of conduct. In addition thermal control of an exothermic reaction (mononitration shows that the consideration of heat generated in the model representation improve the results by elimination any overshooting of the set-point temperature.

Heuristics for batching and sequencing in batch processing machines

Directory of Open Access Journals (Sweden)

Chuda Basnet

2016-12-01

Full Text Available In this paper, we discuss the “batch processing” problem, where there are multiple jobs to be processed in flow shops. These jobs can however be formed into batches and the number of jobs in a batch is limited by the capacity of the processing machines to accommodate the jobs. The processing time required by a batch in a machine is determined by the greatest processing time of the jobs included in the batch. Thus, the batch processing problem is a mix of batching and sequencing – the jobs need to be grouped into distinct batches, the batches then need to be sequenced through the flow shop. We apply certain newly developed heuristics to the problem and present computational results. The contributions of this paper are deriving a lower bound, and the heuristics developed and tested in this paper.

CRC DEPLETION CALCULATIONS FOR THE NON-RODDED ASSEMBLIES IN BATCHES 4 AND 5 OF CRYSTAL RIVER UNIT 3

Energy Technology Data Exchange (ETDEWEB)

Kenneth D. Wright

1997-07-30

The purpose of this design analysis is to document the SAS2H depletion calculations of certain non-rodded fuel assemblies from batches 4 and 5 of the Crystal River Unit 3 pressurized water reactor (PWR) that are required for commercial Reactor Critical (CRC) evaluations to support the development of the disposal criticality methodology. A non-rodded assembly is one which never contains a control rod assembly (CRA) or an axial power shaping rod assembly (APSRA) during its irradiation history. The objective of this analysis is to provide SAS2H generated isotopic compositions for each fuel assembly's depleted fuel and depleted burnable poison materials. These SAS2H generated isotopic compositions are acceptable for use in CRC benchmark reactivity calculations containing the various fuel assemblies.

Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

Science.gov (United States)

Zhu, Linxiao; Raman, Aaswath P.; Fan, Shanhui

2015-01-01

A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities. PMID:26392542

CRC DEPLETION CALCULATIONS FOR THE NON-RODDED ASSEMBLIES IN BATCHES 1, 2, AND 3 OF CRYSTAL RIVER UNIT 3

International Nuclear Information System (INIS)

Wright, Kenneth D.

1997-01-01

The purpose of this design analysis is to document the SAS2H depletion calculations of certain non-rodded fuel assemblies from batches 1, 2, and 3 of the Crystal River Unit 3 pressurized water reactor (PWR) that are required for Commercial Reactor Critical (CRC) evaluations to support development of the disposal criticality methodology. A non-rodded assembly is one which never contains a control rod assembly (CRA) or an axial power shaping rod assembly (APSRA) during its irradiation history. The objective of this analysis is to provide SAS2H generated isotopic compositions for each fuel assembly's depleted fuel and depleted burnable poison materials. These SAS2H generated isotopic compositions are acceptable for use in CRC benchmark reactivity calculations containing the various fuel assemblies

Direct transmission electron microscopy observations of martensitic transformations in Ni-rich NiTi single crystals during in situ cooling and straining

International Nuclear Information System (INIS)

Kroeger, A.; Dziaszyk, S.; Frenzel, J.; Somsen, Ch.; Dlouhy, A.; Eggeler, G.

2008-01-01

We investigate martensitic transformations using transmission electron microscopy (TEM) in compression aged Ni-rich NiTi single crystals with one family of Ni 4 Ti 3 precipitates. Small cylinders from a Ni-rich NiTi single crystal with a Ni content of 51.0 at.% were compression aged at 550 deg. C in the [1 1 1] B2 direction for different aging times. Differential scanning calorimetry (DSC) investigations show that a three-step martensitic transformation (three DSC peaks on cooling from the high temperature regime) can be observed for aging times of 4 ks. In situ cooling TEM investigations reveal that the first peak on cooling is associated with a transformation from B2 to R-phase, starting from all precipitate/matrix interfaces. On further cooling, the B19'-phase appears and grows along precipitate/matrix interfaces (second step). With further decreasing temperature, the remaining R-phase between the precipitates transforms to B19' (third peak). In situ TEM straining experiments of B2 above the martensitic start temperature reveal that first some microstructural regions directly transform in microscopic burst like events from B2 to B19'. On further straining, the B19'-phase grows along precipitate/matrix interfaces. However, no formation of R-phase precedes the formation of stress-induced B19'

Cooling of low-mass carbon-oxygen dwarfs from the planetary nucleus stage through the crystallization stage

International Nuclear Information System (INIS)

Iben, I. Jr.; Tutukov, A.V.

1984-01-01

The evolution of a carbon-oxygen dwarf of mass Mroughly-equal0.6 Msun has been carried all the way from an initial nuclear burning stage, when it is the central star of a planetary nebula, to the stage of complete internal crystallization, after 10 10 yr of cooling. Shell hydrogen and helium burning, neutrino losses, and the effects of liquification and crystallization have been taken into account. We show how the luminosity-time relationship may be understood in terms of balances between competing physical processes and demonstrate that, after complete crystallization, the time scale for cooling to terrestrial-like temperatures, in our approximation, is simply the optical depth of the outer, nonisothermal layer multiplied by a dimensional constant which, in years, is of the order of unity. A luminosity function based on the results covers the range -5< or approx. =log(L/Lsun)< or approx. =4 and agrees reasonably well with the observed luminosity function extending from the brighest planetary nebula nuclei to the dimmest observed white dwarfs, except perhaps for log(L/L/sub sun/)< or approx. =-4.5. Possible reasons for the apparent discrepancy at low luminosity, apart from the extreme obstacles against discovery, are discussed, one of the simplest is that the oldest dwarfs in the solar vicinity are distributed over a distance from the galactic plane that is approx.5 times larger than is the case for the youngest dwarfs; another possibility is that the opacity in the outer layers of the oldest dwarf models has been overestimated (or underestimatedexclamation) by a factor of 5 or more

Analysis and modelling of the energy consumption of chemical batch plants

Energy Technology Data Exchange (ETDEWEB)

Bieler, P.S.

2004-07-01

This report for the Swiss Federal Office of Energy (SFOE) describes two different approaches for the energy analysis and modelling of chemical batch plants. A top-down model consisting of a linear equation based on the specific energy consumption per ton of production output and the base consumption of the plant is postulated. The model is shown to be applicable to single and multi-product batches for batch plants with constant production mix and multi-purpose batch plants in which only similar chemicals are produced. For multipurpose batch plants with highly varying production processes and changing production mix, the top-down model produced inaccurate results. A bottom-up model is postulated for such plants. The results obtained are discussed that show that the electricity consumption for infrastructure equipment was significant and responsible for about 50% of total electricity consumption. The specific energy consumption for the different buildings was related to the degree of automation and the production processes. Analyses of the results of modelling are presented. More detailed analyses of the energy consumption of this apparatus group show that about 30 to 40% of steam energy is lost and thus a large potential for optimisation exists. Various potentials for making savings, ranging from elimination of reflux conditions to the development of a new heating/cooling-system for a generic batch reactor, are identified.

Crystallization: Key thermodynamic, kinetic and hydrodynamic aspects

Indian Academy of Sciences (India)

Crystallization is extensively used in different industrial applications, ... In batch crystallization, a crystalline product with uniform size and shape is desirable, .... y concentration, metastable zone width. C hoi. G. J at. Urbana-Champagne,. USA.

Rapid cooling and cold storage in a silicic magma reservoir recorded in individual crystals.

Science.gov (United States)

Rubin, Allison E; Cooper, Kari M; Till, Christy B; Kent, Adam J R; Costa, Fidel; Bose, Maitrayee; Gravley, Darren; Deering, Chad; Cole, Jim

2017-06-16

Silicic volcanic eruptions pose considerable hazards, yet the processes leading to these eruptions remain poorly known. A missing link is knowledge of the thermal history of magma feeding such eruptions, which largely controls crystallinity and therefore eruptability. We have determined the thermal history of individual zircon crystals from an eruption of the Taupo Volcanic Zone, New Zealand. Results show that although zircons resided in the magmatic system for 10 3 to 10 5 years, they experienced temperatures >650° to 750°C for only years to centuries. This implies near-solidus long-term crystal storage, punctuated by rapid heating and cooling. Reconciling these data with existing models of magma storage requires considering multiple small intrusions and multiple spatial scales, and our approach can help to quantify heat input to and output from magma reservoirs. Copyright © 2017, American Association for the Advancement of Science.

Measurement of cooling coil film heat transfer coefficient with polymer reaction proceeding in a stirred batch reactor; Jugo sonai ni okeru hanno shinko ni tomonau reikyaku coil no kyomaku netsudentatsu keisu no keiji henka

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, K [Soken Chemical and Engineering Co. Ltd., Saitama (Japan); Nishi, K; Kaminoyama, M; Kamiwano, M [Yokohama National University, Yokohama (Japan). Faculty of Engineering

1996-09-10

In radical additional solution polymerization, the viscosity increases with reaction progress. It is important to evaluate beforehand the cooling capacity of the reactor, which worsens with the process. In this study, a stirred batch reactor with both a paddle and a helical screw impeller were studied, and measurements were made for the dynamic changes of the film heat transfer coefficient of the cooling coil with progress of the polymer reaction. We found the change could be evaluated by the calculating heat balance of the generated heat, the viscous dissipation energy and the sensible heat change under conditions of monomer conversion and changing viscosity. 11 refs., 7 figs.

CRC DEPLETION CALCULATIONS FOR THE RODDED ASSEMBLIES IN BATCHES 1, 2, 3, AND 1X OF CRYSTAL RIVER UNIT 3

Energy Technology Data Exchange (ETDEWEB)

Kenneth D. Wright

1997-09-03

The purpose of this design analysis is to document the SAS2H depletion calculations of certain rodded fuel assemblies from batches 1, 2, 3, and 1X of the Crystal River Unit 3 pressurized water reactor (PWR) that are required for Commercial Reactor Critical (CRC) evaluations to support the development of the disposal criticality methodology. A rodded assembly is one that contains a control rod assembly (CRA) or an axial power shaping rod assembly (APSRA) for some period of time during its irradiation history. The objective of this analysis is to provide SAS2H calculated isotopic compositions of depleted fuel and depleted burnable poison for each fuel assembly to be used in subsequent CRC reactivity calculations containing the fuel assemblies.

CRC DEPLETION CALCULATIONS FOR THE RODDED ASSEMBLIES IN BATCHES 1, 2, 3, AND 1X OF CRYSTAL RIVER UNIT 3

International Nuclear Information System (INIS)

Wright, Kenneth D.

1997-01-01

The purpose of this design analysis is to document the SAS2H depletion calculations of certain rodded fuel assemblies from batches 1, 2, 3, and 1X of the Crystal River Unit 3 pressurized water reactor (PWR) that are required for Commercial Reactor Critical (CRC) evaluations to support the development of the disposal criticality methodology. A rodded assembly is one that contains a control rod assembly (CRA) or an axial power shaping rod assembly (APSRA) for some period of time during its irradiation history. The objective of this analysis is to provide SAS2H calculated isotopic compositions of depleted fuel and depleted burnable poison for each fuel assembly to be used in subsequent CRC reactivity calculations containing the fuel assemblies

Monoclinic MB phase and phase instability in [110] field cooled Pb(Zn1/3Nb2/3)O3-4.5%PbTiO3 single crystals

Science.gov (United States)

Yao, Jianjun; Cao, Hu; Ge, Wenwei; Li, Jiefang; Viehland, D.

2009-08-01

We report the finding of a monoclinic MB phase in Pb(Zn1/3Nb2/3)O3-4.5%PbTiO3 single crystals. High precision x-ray diffraction investigations of [110] field cooled crystals have shown a transformation sequence of cubic(C)→tetragonal(T)→orthorhombic(O)→monoclinic(MB), which is different from that previously reported [A.-E. Renault et al., J. Appl. Phys. 97, 044105 (2005)]. Beginning in the zero-field-cooled condition at 383 K, a rhombohedral (R)→MB→O sequence was observed with increasing field. Coexisting MB and O phases were then found upon removal of field, which fully transformed to MB on cooling to room temperature.

Formation of Piroxicam Polymorphism in Solution Crystallization

DEFF Research Database (Denmark)

Bruun Hansen, Thomas; Qu, Haiyan

2015-01-01

also explored, and new insights into polymorphic control are documented and discussed. The crystal landscape was mapped for cooling crystallization of piroxicam from acetone/water mixtures (0.5 K/min) and for antisolvent crystallization from acetone with water as the antisolvent. Varying cooling rates...

A Model-based B2B (Batch to Batch) Control for An Industrial Batch Polymerization Process

Science.gov (United States)

Ogawa, Morimasa

This paper describes overview of a model-based B2B (batch to batch) control for an industrial batch polymerization process. In order to control the reaction temperature precisely, several methods based on the rigorous process dynamics model are employed at all design stage of the B2B control, such as modeling and parameter estimation of the reaction kinetics which is one of the important part of the process dynamics model. The designed B2B control consists of the gain scheduled I-PD/II2-PD control (I-PD with double integral control), the feed-forward compensation at the batch start time, and the model adaptation utilizing the results of the last batch operation. Throughout the actual batch operations, the B2B control provides superior control performance compared with that of conventional control methods.

Pro Spring Batch

CERN Document Server

Minella, Michael T

2011-01-01

Since its release, Spring Framework has transformed virtually every aspect of Java development including web applications, security, aspect-oriented programming, persistence, and messaging. Spring Batch, one of its newer additions, now brings the same familiar Spring idioms to batch processing. Spring Batch addresses the needs of any batch process, from the complex calculations performed in the biggest financial institutions to simple data migrations that occur with many software development projects. Pro Spring Batch is intended to answer three questions: *What? What is batch processing? What

Environmental compatible cooling water treatment chemicals; Umweltvertraegliche Chemikalien in der Kuehlwasserkonditionierung

Energy Technology Data Exchange (ETDEWEB)

Gartiser, S; Urich, E

2002-02-01

In Germany about 32 billion m{sup 3}/a cooling water are discharged from industrial plants and power industry. These are conditioned partly with biocides, scaling and corrosion inhibitors. Within the research project the significance of cooling water chemicals was evaluated, identifying the chemicals from product information, calculating their loads from consumption data of more than 180 cooling plants and investigating the basic data needed for an environmental hazard assessment. Additionally the effects of cooling water samples and products were determined in biological test systems. Batch tests were performed under defined conditions in order to measure the inactivation of cooling water biocides. (orig.)

Estimation of the growth kinetics for the cooling crystallisation of paracetamol and ethanol solutions

Science.gov (United States)

Mitchell, Niall A.; Ó'Ciardhá, Clifford T.; Frawley, Patrick J.

2011-08-01

This work details the estimation of the growth kinetics of paracetamol in ethanol solutions for cooling crystallisation processes, by means of isothermal seeded batch experiments. The growth kinetics of paracetamol crystals were evaluated in isolation, with the growth rate assumed to be size independent. Prior knowledge of the Metastable Zone Width (MSZW) was required, so that supersaturation ratios of 1.7-1.1 could be induced in solution without the occurrence of nucleation. The technique involved the utilisation of two in-situ Process Analytical Techniques (PATs), with a Focused Beam Reflectance Measurement (FBRM ®) utilised to ensure that negligible nucleation occurred and an Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) probe employed for online monitoring of solute concentration. Initial Particle Size Distributions (PSDs) were used in conjunction with desupersaturation profiles to determine the growth rate as a function of temperature and supersaturation. Furthermore, the effects of seed loading and size on the crystal growth rate were investigated. A numerical model, incorporating the population balance equation and the method of moments, was utilised to describe the crystal growth process. Experimental parameters were compared to the model simulation, with the accuracy of the model validated by means of the final product PSDs and solute concentration.

Optimization of heat-liberating batches for ash residue stabilization

International Nuclear Information System (INIS)

Karlina, O.K.; Varlackova, G.A.; Ojovan, M.I.; Tivansky, V.M.; Dmitriev, S.A.

1999-01-01

The ash residue obtained after incineration of solid radioactive waste is a dusting poly-dispersed powder like material that contains radioactive nuclides ( 137 Cs, 90 Sr, 239 Pu, hor ( ellipsis)). Specific radioactivity of the ash can be about 10 5 --10 7 Bq/kg. In order to dispose of the ash, residue shall be stabilized by producing a monolith material. The ash residue can be either vitrified or stabilized into a ceramic matrix. For this purpose the ash residue is mixed with fluxing agents followed by melting of obtained composition in the different type melters. As a rule this requires both significant energy consumption and complex melting equipment. A stabilization technology of ash residue was proposed recently by using heat liberating batches-compositions with redox properties. The ash residue is melted due to exothermic chemical reactions in the mixture with heat-liberating batch that occur with considerable release of heat. Stabilization method has three stages: (1) preparation of a mixture of heating batch and ash residue with or without glass forming batch (frit); (2) ignition and combustion of mixed composition; (3) cooling (quenching) of obtained vitreous material. Combustion of mixed composition occurs in the form of propagation of reacting wave. The heat released during exothermic chemical reactions provides melting of ash residue components and production of glass-like phase. The final product consists of a glass like matrix with embedded crystalline inclusions of infusible ash residue components

Theory of tapered laser cooling

International Nuclear Information System (INIS)

Okamoto, Hiromi; Wei, J.

1998-01-01

A theory of tapered laser cooling for fast circulating ion beams in a storage ring is constructed. The authors describe the fundamentals of this new cooling scheme, emphasizing that it might be the most promising way to beam crystallization. The cooling rates are analytically evaluated to study the ideal operating condition. They discuss the physical implication of the tapering factor of cooling laser, and show how to determine its optimum value. Molecular dynamics method is employed to demonstrate the validity of the present theory

A Differential Scanning Calorimetry Method for Construction of Continuous Cooling Transformation Diagram of Blast Furnace Slag

Science.gov (United States)

Gan, Lei; Zhang, Chunxia; Shangguan, Fangqin; Li, Xiuping

2012-06-01

The continuous cooling crystallization of a blast furnace slag was studied by the application of the differential scanning calorimetry (DSC) method. A kinetic model describing the correlation between the evolution of the degree of crystallization with time was obtained. Bulk cooling experiments of the molten slag coupled with numerical simulation of heat transfer were conducted to validate the results of the DSC methods. The degrees of crystallization of the samples from the bulk cooling experiments were estimated by means of the X-ray diffraction (XRD) and the DSC method. It was found that the results from the DSC cooling and bulk cooling experiments are in good agreement. The continuous cooling transformation (CCT) diagram of the blast furnace slag was constructed according to crystallization kinetic model and experimental data. The obtained CCT diagram characterizes with two crystallization noses at different temperature ranges.

Cation ordering in orthopyroxenes and cooling rates of meteorites: Low temperature cooling rates of Estherville, Bondoc and Shaw

Science.gov (United States)

Ganguly, J.; Yang, H.; Ghose, S.

1993-01-01

The cooling rates of meteorites provide important constraints on the size of their parent bodies, and their accretionary and evolutionary histories. However, the cooling rates obtained so far from the commonly used metallographic, radiometric and fission-track methods have been sometimes quite controversial, such as in the case of the mesosiderites and the meteorite Shaw. We have undertaken a systematic study of the cooling rates of meteorites using a different approach, which involves single crystal x-ray determination of Fe(2+)-Mg ordering in orthopyroxenes (OP(x)) in meteorites, subject to bulk compositional constraints, and numerical simulation of the evolution of the ordering state as a function of cooling rate, within the framework of the thermodynamic and kinetic principles governing cation ordering. We report the results obtained for OP(x) crystals from Shaw and two mesosiderites, Estherville and Bondoc.

Energy efficiency of batch and semi-batch (CCRO) reverse osmosis desalination.

Science.gov (United States)

Warsinger, David M; Tow, Emily W; Nayar, Kishor G; Maswadeh, Laith A; Lienhard V, John H

2016-12-01

As reverse osmosis (RO) desalination capacity increases worldwide, the need to reduce its specific energy consumption becomes more urgent. In addition to the incremental changes attainable with improved components such as membranes and pumps, more significant reduction of energy consumption can be achieved through time-varying RO processes including semi-batch processes such as closed-circuit reverse osmosis (CCRO) and fully-batch processes that have not yet been commercialized or modelled in detail. In this study, numerical models of the energy consumption of batch RO (BRO), CCRO, and the standard continuous RO process are detailed. Two new energy-efficient configurations of batch RO are analyzed. Batch systems use significantly less energy than continuous RO over a wide range of recovery ratios and source water salinities. Relative to continuous RO, models predict that CCRO and batch RO demonstrate up to 37% and 64% energy savings, respectively, for brackish water desalination at high water recovery. For batch RO and CCRO, the primary reductions in energy use stem from atmospheric pressure brine discharge and reduced streamwise variation in driving pressure. Fully-batch systems further reduce energy consumption by not mixing streams of different concentrations, which CCRO does. These results demonstrate that time-varying processes can significantly raise RO energy efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

A crystal barrel

CERN Multimedia

2007-01-01

The production of crystals for the barrel of the CMS electromagnetic calorimeter has been completed. This is an important milestone for the experiment, which received the last of its 62,960 crystals on 9 March. The members of the team responsible for the crystal acceptance testing at CERN display the last crystal for the CMS electromagnetic calorimeter barrel. From left to right: Igor Tarasov, Etiennette Auffray and Hervé Cornet.One of the six machines specially developed to measure 67 different parameters on each crystal. Igor Tarasov is seen inserting the last batch of crystals into the machine. The last of the 62,960 CMS barrel crystals arrived at CERN on 9 March. Once removed from its polystyrene protection, this delicate crystal, like thousands of its predecessors, will be inserted into the last of the 36 supermodules of the barrel electromagnetic calorimeter in a few days' time. This marks the end of an important chapter in an almost 15-year-long journey by the CMS crystals team, some of whose member...

Laser-cooling effects in few-ion clouds of Yb+

International Nuclear Information System (INIS)

Edwards, C.S.; Gill, P.; Klein, H.A.; Levick, A.P.; Rowley, W.R.C.

1994-01-01

We report some laser-cooling effects in a few 172 Yb + ions held in a Paul trap. Pronounced cloud-to-crystal phase transitions have been observed as discontinuities in the Yb + fluorescence spectrum of the 369 nm cooling transition. The first reported two-dimensional images of Yb + clouds with evidence of crystal structure have been recorded using a photon-counting position-sensitive detector. An ion temperature of 100 mK has been estimated from the size of a single ion image. Stepwise cooling of a re-heated, few-ion Yb + cloud was also observed. (orig.)

Uneven batch data alignment with application to the control of batch end-product quality.

Science.gov (United States)

Wan, Jian; Marjanovic, Ognjen; Lennox, Barry

2014-03-01

Batch processes are commonly characterized by uneven trajectories due to the existence of batch-to-batch variations. The batch end-product quality is usually measured at the end of these uneven trajectories. It is necessary to align the time differences for both the measured trajectories and the batch end-product quality in order to implement statistical process monitoring and control schemes. Apart from synchronizing trajectories with variable lengths using an indicator variable or dynamic time warping, this paper proposes a novel approach to align uneven batch data by identifying short-window PCA&PLS models at first and then applying these identified models to extend shorter trajectories and predict future batch end-product quality. Furthermore, uneven batch data can also be aligned to be a specified batch length using moving window estimation. The proposed approach and its application to the control of batch end-product quality are demonstrated with a simulated example of fed-batch fermentation for penicillin production. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Realisation of a novel crystal bender for a fast double crystal monochromator

CERN Document Server

Zaeper, R; Wollmann, R; Luetzenkirchen-Hecht, D; Frahm, R

2001-01-01

A novel crystal bender for an X-ray undulator beamline as part of a fast double crystal monochromator development for full EXAFS energy range was characterized. Rocking curves of the monochromator crystal system were recorded under different heat loads and bending forces of the indirectly cooled first Si(1 1 1) crystal. The monochromator development implements new piezo-driven tilt tables with wide angular range to adjust the crystals' Bragg angles and a high pressure actuated bender mechanism for the first crystal.

CRYSTALLIZATION KINETICS OF AMMONIUM PERCHLORATE IN AN AGITATED VESSEL

Directory of Open Access Journals (Sweden)

Nahidh Kaseer

2013-05-01

Full Text Available 31Overall crystal growth kinetics for ammonium perchlorate in laboratory scale batch  agitated vessel crystallizer have been determined from batch experiments performed in an integral mode. The effects of temperature between 30-60ºC, seed size 0.07, 0.120 and 0.275 mm and stirrer speed 160, 340, and 480 rpm, on the kinetics of crystal growth were investigated. Two different methods, viz. polynomial fitting and initial derivative were used to predict the kinetics expression. In general both methods gave comparable results for growth kinetics estimation. The order of growth process is not more than two. The activation energy for crystal growth of ammonium perchlorate was determined and found  to be equal to 5.8 kJ/ mole.            Finally, the influence of the affecting parameters on the crystal growth rate gives general expression that had an obvious dependence of the growth rate on each variables of concern (temperature, seed size, and stirrer speed .The general overall growth rate expression had shown that super saturation is the most significant variable. While the positive dependence of the stirrer speed demonstrates the importance of the diffusional step in the growth rate model. Moreover, the positive dependence of the seed size demonstrate the importance of the surface integration  step in the growth rate model. All the studied variables tend to suggest that the growth rate characteristics  of ammonium perchlorate from aqueous solution commenced in a batch crystallizer are diffusion kinetic controlled process.

Effect of Fe2O3 on the crystallization behavior of glass-ceramics produced from naturally cooled yellow phosphorus furnace slag

Science.gov (United States)

Liu, Hong-pan; Huang, Xiao-feng; Ma, Li-ping; Chen, Dan-li; Shang, Zhi-biao; Jiang, Ming

2017-03-01

CaO-Al2O3-SiO2 (CAS) glass-ceramics were prepared via a melting method using naturally cooled yellow phosphorus furnace slag as the main raw material. The effects of the addition of Fe2O3 on the crystallization behavior and properties of the prepared glass-ceramics were studied by differential thermal analysis, X-ray diffraction, and scanning electron microscopy. The crystallization activation energy was calculated using the modified Johnson-Mehl-Avrami equation. The results show that the intrinsic nucleating agent in the yellow phosphorus furnace slag could effectively promote the crystallization of CAS. The crystallization activation energy first increased and then decreased with increasing amount of added Fe2O3. At 4wt% of added Fe2O3, the crystallization activation energy reached a maximum of 676.374 kJ·mol-1. The type of the main crystalline phase did not change with the amount of added Fe2O3. The primary and secondary crystalline phases were identified as wollastonite (CaSiO3) and hedenbergite (CaFe(Si2O6)), respectively.

Use of Plastic Capillaries for Macromolecular Crystallization

Science.gov (United States)

Potter, Rachel R.; Hong, Young-Soo; Ciszak, Ewa M.

2003-01-01

Methods of crystallization of biomolecules in plastic capillaries (Nalgene 870 PFA tubing) are presented. These crystallization methods used batch, free-interface liquid- liquid diffusion alone, or a combination with vapor diffusion. Results demonstrated growth of crystals of test proteins such as thaumatin and glucose isomerase, as well as protein studied in our laboratory such dihydrolipoamide dehydrogenase. Once the solutions were loaded in capillaries, they were stored in the tubes in frozen state at cryogenic temperatures until the desired time of activation of crystallization experiments.

Crystallization of ornithine acetyltransferase from yeast by counter-diffusion and preliminary X-ray study

Energy Technology Data Exchange (ETDEWEB)

Maes, Dominique, E-mail: dominique.maes@vub.ac.be; Crabeel, Marjolaine [Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel (VUB) and Vlaams Interuniversitair Instituut voor Biotechnologie (VIB), Pleinlaan 2, B-1050 Brussels (Belgium); Van de Weerdt, Cécile; Martial, Joseph [Laboratoire de Biologie Moléculaire et de Génie Génétique, Université de Liège, Allée de la Chimie 3, B-4000 Liège (Belgium); Peeters, Eveline; Charlier, Daniël [Erfelijkheidsleer en Microbiologie, Vrije Universiteit Brussel (VUB), Pleinlaan 2, B-1050 Brussels (Belgium); Decanniere, Klaas; Vanhee, Celine; Wyns, Lode; Zegers, Ingrid [Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel (VUB) and Vlaams Interuniversitair Instituut voor Biotechnologie (VIB), Pleinlaan 2, B-1050 Brussels (Belgium)

2006-12-01

A study on the crystallization of ornithine acetyltransferase from yeast, catalysing the fifth step in microbial arginine synthesis, is presented. The use of the counter-diffusion technique removes the disorder present in one dimension in crystals grown by either batch or hanging-drop techniques. A study is presented on the crystallization of ornithine acetyltransferase from yeast, which catalyzes the fifth step in microbial arginine synthesis. The use of the counter-diffusion technique removes the disorder present in one dimension in crystals grown by either the batch or hanging-drop techniques. This makes the difference between useless crystals and crystals that allow successful determination of the structure of the protein. The crystals belong to space group P4, with unit-cell parameters a = b = 66.98, c = 427.09 Å, and a data set was collected to 2.76 Å.

Systematic observability and detectablity analysis of industrial batch crystallizers

NARCIS (Netherlands)

Porru, M.; Ozkan, L.

Motivated by the lack of hardware analysers for particle size distribution (PSD) and solute concentration measurements in industrial crystallizers, this work investigates the feasibility of designing alternative monitoring tools based on state observers. The observability and detectability

Numerical simulation of distorted crystal Darwin width

International Nuclear Information System (INIS)

Wang Li; Xu Zhongmin; Wang Naxiu

2012-01-01

A new numerical simulation method according to distorted crystal optical theory was used to predict the direct-cooling crystal monochromator optical properties(crystal Darwin width) in this study. The finite element analysis software was used to calculate the deformed displacements of DCM crystal and to get the local reciprocal lattice vector of distorted crystal. The broadening of direct-cooling crystal Darwin width in meridional direction was estimated at 4.12 μrad. The result agrees well with the experimental data of 5 μrad, while it was 3.89 μrad by traditional calculation method of root mean square (RMS) of the slope error in the center line of footprint. The new method provides important theoretical support for designing and processing of monochromator crystal for synchrotron radiation beamline. (authors)

Effect of temperature on the morphology and electro-optical properties of liquid crystal physical gel

International Nuclear Information System (INIS)

Leaw, W.L.; Mamat, C.R.; Triwahyono, S.; Jalil, A.A.; Bidin, N.

2016-01-01

Liquid crystal physical gels were (thermally) prepared with cholesteryl stearate as a gelator in nematic liquid crystal, 4-cyano-4′-pentylbiphenyl. The electro-optical performance of liquid crystal physical gels is almost entirely dependent on the gels' inherent morphology. This study involved an empirical investigation of the relationships among all of the gelation temperature, morphology, and electro-optical properties. Besides continuous cooling at room temperature, isothermal cooling was also performed at both 18 and 0 °C, corresponding to near-solid and solid phases of 4-cyano-4′-pentylbiphenyl respectively. Nevertheless, the liquid crystal physical gel was also isothermally rapidly cooled using liquid nitrogen. Polarizing optical microscopy showed that the gel structure became thinner when isothermal cooling was carried out. These thinner gel aggregates then interconnected to form larger liquid crystal domains. Moreover, it was also revealed that the gel networks were randomized. Electron spin resonance results showed that the liquid crystal director orientation was severely randomized in the presence of gel networks. Conversely, isothermal cooling using liquid nitrogen generated a higher liquid crystal director orientation order. The 6.0 wt% cholesteryl stearate/4-cyano-4′-pentylbiphenyl physical gel that was isothermally cooled using liquid nitrogen showed the lowest response time in a twisted nematic mode optical cell. - Graphical abstract: Liquid crystal physical gel was prepared using nematic liquid crystal, 4-cyano-4′-pentylbiphenyl and cholesteryl stearate as gelator. Isothermal cooling at lower temperature produced thinner gel network and larger liquid crystal domain. - Highlights: • 5CB nematic liquid crystal was successfully gelled by cholesteryl stearate gelator. • The morphology of gel network was controlled by different cooling conditions. • Thinner gel network was formed by the rapid cooling using liquid nitrogen. • Enhanced

Effect of temperature on the morphology and electro-optical properties of liquid crystal physical gel

Energy Technology Data Exchange (ETDEWEB)

Leaw, W.L. [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia); Mamat, C.R., E-mail: che@kimia.fs.utm.my [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia); Triwahyono, S. [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia); Jalil, A.A. [Department of Chemical Engineering, Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia); Centre of Hydrogen Energy, Institute of Future Energy, Univerisiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia); Bidin, N. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor (Malaysia)

2016-12-01

Liquid crystal physical gels were (thermally) prepared with cholesteryl stearate as a gelator in nematic liquid crystal, 4-cyano-4′-pentylbiphenyl. The electro-optical performance of liquid crystal physical gels is almost entirely dependent on the gels' inherent morphology. This study involved an empirical investigation of the relationships among all of the gelation temperature, morphology, and electro-optical properties. Besides continuous cooling at room temperature, isothermal cooling was also performed at both 18 and 0 °C, corresponding to near-solid and solid phases of 4-cyano-4′-pentylbiphenyl respectively. Nevertheless, the liquid crystal physical gel was also isothermally rapidly cooled using liquid nitrogen. Polarizing optical microscopy showed that the gel structure became thinner when isothermal cooling was carried out. These thinner gel aggregates then interconnected to form larger liquid crystal domains. Moreover, it was also revealed that the gel networks were randomized. Electron spin resonance results showed that the liquid crystal director orientation was severely randomized in the presence of gel networks. Conversely, isothermal cooling using liquid nitrogen generated a higher liquid crystal director orientation order. The 6.0 wt% cholesteryl stearate/4-cyano-4′-pentylbiphenyl physical gel that was isothermally cooled using liquid nitrogen showed the lowest response time in a twisted nematic mode optical cell. - Graphical abstract: Liquid crystal physical gel was prepared using nematic liquid crystal, 4-cyano-4′-pentylbiphenyl and cholesteryl stearate as gelator. Isothermal cooling at lower temperature produced thinner gel network and larger liquid crystal domain. - Highlights: • 5CB nematic liquid crystal was successfully gelled by cholesteryl stearate gelator. • The morphology of gel network was controlled by different cooling conditions. • Thinner gel network was formed by the rapid cooling using liquid nitrogen. �

Production of nattokinase by batch and fed-batch culture of Bacillus subtilis.

Science.gov (United States)

Cho, Young-Han; Song, Jae Yong; Kim, Kyung Mi; Kim, Mi Kyoung; Lee, In Young; Kim, Sang Bum; Kim, Hyeon Shup; Han, Nam Soo; Lee, Bong Hee; Kim, Beom Soo

2010-09-30

Nattokinase was produced by batch and fed-batch culture of Bacillus subtilis in flask and fermentor. Effect of supplementing complex media (peptone, yeast extract, or tryptone) was investigated on the production of nattokinase. In flask culture, the highest cell growth and nattokinase activity were obtained with 50 g/L of peptone supplementation. In this condition, nattokinase activity was 630 unit/ml at 12 h. In batch culture of B. subtilis in fermentor, the highest nattokinase activity of 3400 unit/ml was obtained at 10h with 50 g/L of peptone supplementation. From the batch kinetics data, it was shown that nattokinase production was growth-associated and culture should be harvested before stationary phase for maximum nattokinase production. In fed-batch culture of B. subtilis using pH-stat feeding strategy, cell growth (optical density monitored at 600 nm) increased to ca. 100 at 22 h, which was 2.5 times higher than that in batch culture. The highest nattokinase activity was 7100 unit/ml at 19 h, which was also 2.1 times higher than that in batch culture. Copyright 2010 Elsevier B.V. All rights reserved.

Nonlinear MIMO Control of a Continuous Cooling Crystallizer

Directory of Open Access Journals (Sweden)

Pedro Alberto Quintana-Hernández

2012-01-01

Full Text Available In this work, a feedback control algorithm was developed based on geometric control theory. A nonisothermal seeded continuous crystallizer model was used to test the algorithm. The control objectives were the stabilization of the third moment of the crystal size distribution (μ3 and the crystallizer temperature (T; the manipulated variables were the stirring rate and the coolant flow rate. The nonlinear control (NLC was tested at operating conditions established within the metastable zone. Step changes of magnitudes ±0.0015 and ±0.5°C were introduced into the set point values of the third moment and crystallizer temperature, respectively. In addition, a step change of ±1°C was introduced as a disturbance in the feeding temperature. Closed-loop stability was analyzed by calculating the eigenvalues of the internal dynamics. The system presented a stable dynamic behavior when the operation conditions maintain the crystallizer concentration within the metastable zone. Closed-loop simulations with the NLC were compared with simulations that used a classic PID controller. The PID controllers were tuned by minimizing the integral of the absolute value of the error (IAE criterion. The results showed that the NLC provided a suitable option for continuous crystallization control. For all analyzed cases, the IAEs obtained with NLC were smaller than those obtained with the PID controller.

Influence of additive L-phenylalanine on stabilization of metastable α-form of L-glutamic acid in cooling crystallization

Science.gov (United States)

Quang, Khuu Chau; Nhan, Le Thi Hong; Huyen, Trinh Thi Thanh; Tuan, Nguyen Anh

2017-09-01

The influence of additive amino acid L-phenylalanine on stabilization of metastable α-form of L-glutamic acid was investigated in cooling crystallization. The present study found that the additive L-phenylalanine could be used to stabilize the pure metastable α-form in L-glutamic acid crystallization, where the additive concentration of 0.05-0.1 (g/L) was sufficient to stabilize the 100% wt metastable α-form in solid product at L-glutamic acid concentration of 30-45 (g/L). Additionally, the present results indicated that the adsorption of additive L-phenylalanine on the (001) surface of α-form was more favorable than that of the β-form molecular, so the nucleation sites of stable β-form was occupied by additive molecular, which resulted in inhibition of nucleation and growth of β-form, allowing stabilization of metastable α-form.

Morphological evolution of copper nanoparticles: Microemulsion reactor system versus batch reactor system

Science.gov (United States)

Xia, Ming; Tang, Zengmin; Kim, Woo-Sik; Yu, Taekyung; Park, Bum Jun

2017-07-01

In the synthesis of nanoparticles, the reaction rate is important to determine the morphology of nanoparticles. We investigated morphology evolution of Cu nanoparticles in this two different reactors, microemulsion reactor and batch reactor. In comparison with the batch reactor system, the enhanced mass and heat transfers in the emulsion system likely led to the relatively short nucleation time and the highly homogeneous environment in the reaction mixture, resulting in suppressing one or two dimensional growth of the nanoparticles. We believe that this work can offer a good model system to quantitatively understand the crystal growth mechanism that depends strongly on the local monomer concentration, the efficiency of heat transfer, and the relative contribution of the counter ions (Br- and Cl-) as capping agents.

Thermal expansion and cooling rate dependence of transition temperature in ZrTiO4 single crystal

International Nuclear Information System (INIS)

Park, Y.

1998-01-01

Thermal expansion in ZrTiO 4 single crystal was investigated in the temperature range covering the normal, incommensurate, and commensurate phases. Remarkable change was found at the normal-incommensurate phase transition (T I ) in all thermal expansion coefficients a, b, and c. The spontaneous strains χ as and χ bs along the a and b axes show linear temperature dependence, while the spontaneous strain χ cs along the c axis shows a nonlinear temperature dependence. Small discontinuity along the c direction was observed at the incommensurate-commensurate transition temperature, T c = 845 C. dT I /dP and dT c /dP depend on the cooling rate

Cooling and crystallization of rhyolite-obsidian lava: Insights from micron-scale projections on plagioclase microlites

Science.gov (United States)

Sano, Kyohei; Toramaru, Atsushi

2017-07-01

To reveal the cooling process of a rhyolite-obsidian flow, we studied the morphology of plagioclase microlites in the Tokachi-Ishizawa lava of Shirataki, northern Hokkaido, Japan, where the structure of the lava can be observed from obsidian at the base of the flow to the innermost rhyolite. Needle-like micron-scale textures, known as "projections", occur on the short side surfaces of the plagioclase microlites. Using FE-SEM we discovered a positive correlation between the lengths and spacings of these projections. On the basis of the instability theory of an interface between melt and crystal, and to understand the length and spacing data, we developed a model that explains the positive correlation and allows us to simultaneously estimate growth rates and growth times. Applying the model to our morphological data and the estimated growth rates and growth times, we suggest that the characteristics of the projections reflect the degree of undercooling, which in turn correlates with lava structure (the obsidian at the margin of the flow experienced a higher degree of undercooling than the interior rhyolite). The newly developed method provides insights into the degree of undercooling during the final stages of crystallization of a rhyolitic lava flow.

Protein-crystal growth experiment (planned)

Science.gov (United States)

Fujita, S.; Asano, K.; Hashitani, T.; Kitakohji, T.; Nemoto, H.; Kitamura, S.

1988-01-01

To evaluate the effectiveness of a microgravity environment on protein crystal growth, a system was developed using 5 cubic feet Get Away Special payload canister. In the experiment, protein (myoglobin) will be simultaneously crystallized from an aqueous solution in 16 crystallization units using three types of crystallization methods, i.e., batch, vapor diffusion, and free interface diffusion. Each unit has two compartments: one for the protein solution and the other for the ammonium sulfate solution. Compartments are separated by thick acrylic or thin stainless steel plates. Crystallization will be started by sliding out the plates, then will be periodically recorded up to 120 hours by a still camera. The temperature will be passively controlled by a phase transition thermal storage component and recorded in IC memory throughout the experiment. Microgravity environment can then be evaluated for protein crystal growth by comparing crystallization in space with that on Earth.

Supersaturation Control using Analytical Crystal Size Distribution Estimator for Temperature Dependent in Nucleation and Crystal Growth Phenomena

Science.gov (United States)

Zahari, Zakirah Mohd; Zubaidah Adnan, Siti; Kanthasamy, Ramesh; Saleh, Suriyati; Samad, Noor Asma Fazli Abdul

2018-03-01

The specification of the crystal product is usually given in terms of crystal size distribution (CSD). To this end, optimal cooling strategy is necessary to achieve the CSD. The direct design control involving analytical CSD estimator is one of the approaches that can be used to generate the set-point. However, the effects of temperature on the crystal growth rate are neglected in the estimator. Thus, the temperature dependence on the crystal growth rate needs to be considered in order to provide an accurate set-point. The objective of this work is to extend the analytical CSD estimator where Arrhenius expression is employed to cover the effects of temperature on the growth rate. The application of this work is demonstrated through a potassium sulphate crystallisation process. Based on specified target CSD, the extended estimator is capable of generating the required set-point where a proposed controller successfully maintained the operation at the set-point to achieve the target CSD. Comparison with other cooling strategies shows a reduction up to 18.2% of the total number of undesirable crystals generated from secondary nucleation using linear cooling strategy is achieved.

Laser-cooling effects in few-ion clouds of Yb[sup +

Energy Technology Data Exchange (ETDEWEB)

Edwards, C.S. (National Physical Lab., Teddington (United Kingdom)); Gill, P. (National Physical Lab., Teddington (United Kingdom)); Klein, H.A. (National Physical Lab., Teddington (United Kingdom)); Levick, A.P. (National Physical Lab., Teddington (United Kingdom)); Rowley, W.R.C. (National Physical Lab., Teddington (United Kingdom))

1994-08-01

We report some laser-cooling effects in a few [sup 172]Yb[sup +] ions held in a Paul trap. Pronounced cloud-to-crystal phase transitions have been observed as discontinuities in the Yb[sup +] fluorescence spectrum of the 369 nm cooling transition. The first reported two-dimensional images of Yb[sup +] clouds with evidence of crystal structure have been recorded using a photon-counting position-sensitive detector. An ion temperature of 100 mK has been estimated from the size of a single ion image. Stepwise cooling of a re-heated, few-ion Yb[sup +] cloud was also observed. (orig.)

Preventing Crystal Agglomeration of Pharmaceutical Crystals Using Temperature Cycling and a Novel Membrane Crystallization Procedure for Seed Crystal Generation

Directory of Open Access Journals (Sweden)

Elena Simone

2018-01-01

Full Text Available In this work, a novel membrane crystallization system was used to crystallize micro-sized seeds of piroxicam monohydrate by reverse antisolvent addition. Membrane crystallization seeds were compared with seeds produced by conventional antisolvent addition and polymorphic transformation of a fine powdered sample of piroxicam form I in water. The membrane crystallization process allowed for a consistent production of pure monohydrate crystals with narrow size distribution and without significant agglomeration. The seeds were grown in 350 g of 20:80 w/w acetone-water mixture. Different seeding loads were tested and temperature cycling was applied in order to avoid agglomeration of the growing crystals during the process. Focused beam reflectance measurement (FBRM; and particle vision and measurement (PVM were used to monitor crystal growth; nucleation and agglomeration during the seeded experiments. Furthermore; Raman spectroscopy was used to monitor solute concentration and estimate the overall yield of the process. Membrane crystallization was proved to be the most convenient and consistent method to produce seeds of highly agglomerating compounds; which can be grown via cooling crystallization and temperature cycling.

Vitrification and Crystallization of Phase-Separated Metallic Liquid

Directory of Open Access Journals (Sweden)

Yun Cheng

2017-02-01

Full Text Available The liquid–liquid phase separation (LLPS behavior of Fe50Cu50 melt from 3500 K to 300 K with different rapid quenching is investigated by molecular dynamics (MD simulation based on the embedded atom method (EAM. The liquid undergoes metastable phase separation by spinodal decomposition in the undercooled regime and subsequently solidifies into three different Fe-rich microstructures: the interconnected-type structure is kept in the glass and crystal at a higher cooling rate, while the Fe-rich droplets are found to crystalize at a lower cooling rate. During the crystallization process, only Fe-rich clusters can act as the solid nuclei. The twinning planes can be observed in the crystal and only the homogeneous atomic stacking shows mirror symmetry along the twinning boundary. Our present work provides atomic-scale understanding of LLPS melt during the cooling process.

Induced Nanocrystallization of Dextrose Monohydrate

Science.gov (United States)

Johnson, Irudayaraj; Raj, B. Kanickai; Sivagami, V.; Selvi, Naga Pondy

2013-09-01

Modern ultrasound induction is very much useful in crystallization process. It uses piezoelectric transducers or quartz crystals to convert mechanical waves to electrical signals and vice versa. Growth of a crystal is environment dependent. The characteristics of grown crystals depend on impurities, temperature, preparation of the solution and mechanical agitation. The properties and size of a crystal can be tailored by controlling any one or all the above factors. The most interesting fact is that the ultrasound influences the properties and size of a crystal. It is found that the characteristics are improved and tailored for a specific need of the industry when a crystal is grown by radiating ultrasonic wave. In some cases, it produces nanocrystals. We used a device which generates the Ultrasonic wave of 15 MHz, which is applied to the crystal right from the time before nucleation till the crystal formation. The Dextrose monohydrate crystals are grown by conventional slow cool batch method. In the same slow cool batch method, Ultrasonic waves of 15 MHz are allowed to pass, influence the nucleation, crystal formation and growing process. The crystal formation process under the exposure of Ultrasound is allowed to continue for a sufficiently long time to yield the desired nanocrystals. The FTIR, UV, microhardness and SEM analysis are taken for the crystals with and without ultrasound.

Cooling Crystallization of Indomethacin: Effect of Supersaturation, Temperature and Seeding on Polymorphism and Crystal Size Distribution

DEFF Research Database (Denmark)

Malwade, Chandrakant Ramkrishna; Qu, Haiyan

2018-01-01

In this work, effect of crystallization parameters i.e., supersaturation, seeding, and temperature on polymorphism and crystal size of a non-steroidal anti-inflammatory drug, indomethacin (IMC), was investigated. Firstly, several crystallization solvents (ethanol, methanol, ethyl acetate, acetone...... of IMC from ethanol confirmed that the supersaturation, operating temperature and seeding does affect the polymorphism as well as crystal size distribution of IMC. Fine needle shaped crystals of metastable α-IMC were obtained at 5 °C with high supersaturation even in presence of γ-IMC seeds, while...... rhombic plates like crystals of thermodynamically stable γ-IMC were obtained in remaining experiments. The amount of seed loading only marginally influenced the crystal growth rate and median particle diameter (d50). Particle size analysis of crystals obtained showed bimodal distribution in all...

SPS batch spacing optimisation

CERN Document Server

Velotti, F M; Carlier, E; Goddard, B; Kain, V; Kotzian, G

2017-01-01

Until 2015, the LHC filling schemes used the batch spac-ing as specified in the LHC design report. The maximumnumber of bunches injectable in the LHC directly dependson the batch spacing at injection in the SPS and hence onthe MKP rise time.As part of the LHC Injectors Upgrade project for LHCheavy ions, a reduction of the batch spacing is needed. In thisdirection, studies to approach the MKP design rise time of150ns(2-98%) have been carried out. These measurementsgave clear indications that such optimisation, and beyond,could be done also for higher injection momentum beams,where the additional slower MKP (MKP-L) is needed.After the successful results from 2015 SPS batch spacingoptimisation for the Pb-Pb run [1], the same concept wasthought to be used also for proton beams. In fact, thanksto the SPS transverse feed back, it was already observedthat lower batch spacing than the design one (225ns) couldbe achieved. For the 2016 p-Pb run, a batch spacing of200nsfor the proton beam with100nsbunch spacing wasreque...

Study of crystallization kinetics of peek thermoplastics using Nakamura equation

Science.gov (United States)

Chalid, Mochamad; Muhammad Joshua Y., B.; Fikri, Arbi Irsyad; Gregory, Noel; Priadi, Dedi; Fatriansyah, Jaka Fajar

2018-04-01

We have simulated the time evolution of relative crystallization of PEEK at various cooling rates (10, 15, 20 °C/min) and made comparison with the experiments. The simulation was conducted using Nakamura model which is a modified Avrami model. The model is a 1 cm radius of circle with the cooling plate which was placed in the upper part of the circle. The cooling plate temperature was varied in order to obtain particular cooling rates. The measurement point is located near upper boundary in order to minimize the heat transfer effect. The general trend of time evolution of crystallization was well captured although some discrepancies occured. These discrepancies may be attributed to the heat transfer effect and secondary crystallization.

Cavity QED experiments with ion Coulomb crystals

DEFF Research Database (Denmark)

Herskind, Peter Fønss; Dantan, Aurélien; Marler, Joan

2009-01-01

Cavity QED experimental results demonstrating collective strong coupling between ensembles of atomic ions cooled into Coulomb crystals and optical cavity fields have been achieved. Collective Zeeman coherence times of milliseconds have furthermore been obtained.......Cavity QED experimental results demonstrating collective strong coupling between ensembles of atomic ions cooled into Coulomb crystals and optical cavity fields have been achieved. Collective Zeeman coherence times of milliseconds have furthermore been obtained....

Effects of temperature and solvent concentration on the solvent crystallization of palm-based dihydroxystearic acid with isopropyl alcohol

Institute of Scientific and Technical Information of China (English)

Gregory F.L.Koay; Teong-Guan Chuah; Sumaiya Zainal-Abidin; Salmiah Ahmad; Thomas S.Y.Choong

2012-01-01

Palm-based dihydroxystearic acid of 69.55％ purity was produced in a 500-kg-per-batch operation pilot plant and purified through solvent crystallization in a custom fabricated simultaneous batch crystallizer unit.The effects of temperature and solvent concentration on yield,particle size distribution and purity were studied.The purity was higher,while the yield and particle size were lower and smaller,respectively,at higher temperature and solvent concentration.The solvent crystallization process efficiency was rated at 66-69％ when carried out with 70-80％ isopropyl alcohol at 20 ℃.

History Dependence of the Microstructure on Time-Dependent Deformation During In-Situ Cooling of a Nickel-Based Single-Crystal Superalloy

Science.gov (United States)

Panwisawas, Chinnapat; D'Souza, Neil; Collins, David M.; Bhowmik, Ayan; Roebuck, Bryan

2018-05-01

Time-dependent plastic deformation through stress relaxation and creep deformation during in-situ cooling of the as-cast single-crystal superalloy CMSX-4® has been studied via neutron diffraction, transmission electron microscopy, electro-thermal miniature testing, and analytical modeling across two temperature regimes. Between 1000 °C and 900 °C, stress relaxation prevails and gives rise to softening as evidenced by a decreased dislocation density and the presence of long segment stacking faults in γ phase. Lattice strains decrease in both the γ matrix and γ' precipitate phases. A constitutive viscoplastic law derived from in-situ isothermal relaxation test under-estimates the equivalent plastic strain in the prediction of the stress and strain evolution during cooling in this case. It is thereby shown that the history dependence of the microstructure needs to be taken into account while deriving a constitutive law and which becomes even more relevant at high temperatures approaching the solvus. Higher temperature cooling experiments have also been carried out between 1300 °C and 1150 °C to measure the evolution of stress and plastic strain close to the γ' solvus temperature. In-situ cooling of samples using ETMT shows that creep dominates during high-temperature deformation between 1300 °C and 1220 °C, but below a threshold temperature, typically 1220 °C work hardening begins to prevail from increasing γ' fraction and resulting in a rapid increase in stress. The history dependence of prior accumulated deformation is also confirmed in the flow stress measurements using a single sample while cooling. The saturation stresses in the flow stress experiments show very good agreement with the stresses measured in the cooling experiments when viscoplastic deformation is dominant. This study demonstrates that experimentation during high-temperature deformation as well as the history dependence of the microstructure during cooling plays a key role in deriving

Process Analytical Technology in Freeze-Drying: Detection of the Secondary Solute + Water Crystallization with Heat Flux Sensors.

Science.gov (United States)

Wang, Qiming; Shalaev, Evgenyi

2018-04-01

In situ and non-invasive detection of solute crystallization during freeze-drying would facilitate cycle optimization and scale-up from the laboratory to commercial manufacturing scale. The objective of the study is to evaluate heat flux sensor (HFS) as a tool for monitoring solute crystallization and other first-order phase transitions (e.g., onset of freezing). HFS is a thin-film differential thermopile, which acts as a transducer to generate an electrical signal proportional to the total heat applied to its surface. In this study, HFS is used to detect both primary (ice formation) and secondary (also known as eutectic) solute + water crystallization during cooling and heating of solutions in a freeze-dryer. Binary water-solute mixtures with typical excipients concentrations (e.g., 0.9% of NaCl and 5% mannitol) and fill volumes (1 to 3 ml/vial) are studied. Secondary crystallization is detected by the HFS during cooling in all experiments with NaCl solutions, whereas timing of mannitol crystallization depends on the cooling conditions. In particular, mannitol crystallization takes place during cooling, if the cooling rate is lower than the critical value. On the other hand, if the cooling rate exceeds the critical cooling rate, mannitol crystallization during cooling is prevented, and crystallization occurs during subsequent warming or annealing. It is also observed that, while controlled ice nucleation allows initiation of the primary freezing event in different vials simultaneously, there is a noticeable vial-to-vial difference in the timing of secondary crystallization. The HFS could be a valuable process monitoring tool for non-invasive detection of various crystallization events during freeze-drying manufacturing.

Solubility and crystallization of piroxicam from different solvents in evaporative and cooling crystallizations

DEFF Research Database (Denmark)

Qu, Haiyan; Ostergaard, Iben

2018-01-01

polarities; It has been found that the solubility of piroxicam in the solvents is in the following order: chloroform > dichloromethane > acetone > ethyl acetate > acetonitrile > acetic acid > methanol > hexane. Crystallization of piroxicam from different solvents has been performed with evaporative.......Results obtained in the present work showed the stochastic nature of nucleation of different polymorphs as well as the complexity of the crystallization of a polymorphic system....

The cryogenic cooling program at the Advanced Photon Source

International Nuclear Information System (INIS)

Rogers, C.S.; Mills, D.M.; Assoufid, L.

1994-06-01

This paper describes the experimental and analytical program in cryogenic cooling of high-heat-load optics at the Advanced-Photon Source. A prototype liquid nitrogen pumping system has been procured. This pump provides a variable flow rate of 1 to 10 gpm of pressurized liquid nitrogen and is sized to handle up to 5 kW of optic heat load. Also, a high-vacuum, double-crystal monochromator testing tank has been fabricated. This system will be used to test cryogenic crystals at existing synchrotron sources. A finite element analysis has been performed for a cryogenically cooled Si crystal in the inclined geometry for Undulator A at 100 mA. The inclination angle was 80 degrees. It was set to diffract from the (111) planes at the first harmonic energy of 4.2 keV. The maximum slope error in the diffraction plane was calculated to be about 1 μrad with a peak temperature of 94 K. An analysis has also been performed for a cryogenically-cooled ''thin'' crystal oriented in the Bragg geometry which accepts 87% of the lst harmonic photons at 3.866 keV. The total absorbed power was 131 W at 100 mA current and the peak temperature was 124 K

Is cold better ? - exploring the feasibility of liquid-helium-cooled optics

International Nuclear Information System (INIS)

Assoufid, L.; Mills, D.; Macrander, A.; Tajiri, G.

1999-01-01

Both simulations and recent experiments conducted at the Advanced Photon Source showed that the performance of liquid-nitrogen-cooled single-silicon crystal monochromators can degrade in a very rapid nonlinear fashion as the power and for power density is increased. As a further step towards improving the performance of silicon optics, we propose cooling with liquid helium, which dramatically improves the thermal properties of silicon beyond that of liquid nitrogen and brings the performance of single silicon-crystal-based synchrotrons radiation optics up to the ultimate limit. The benefits of liquid helium cooling as well as some of the associated technical challenges will be discussed, and results of thermal and structural finite elements simulations comparing the performance of silicon monochromators cooled with liquid nitrogen and helium will be given

Heat load studies of a water-cooled minichannel monochromator for synchrotron x-ray beams

Science.gov (United States)

Freund, Andreas K.; Arthur, John R.; Zhang, Lin

1997-12-01

We fabricated a water-cooled silicon monochromator crystal with small channels for the special case of a double-crystal fixed-exit monochromator design where the beam walks across the crystal when the x-ray energy is changed. The two parts of the cooled device were assembled using a new technique based on low melting point solder. The bending of the system produced by this technique could be perfectly compensated by mechanical counter-bending. Heat load tests of the monochromator in a synchrotron beam of 75 W total power, 3 mm high and 15 mm wide, generated by a multipole wiggler at SSRL, showed that the thermal slope error of the crystal is 1 arcsec/40 W power, in full agreement with finite element analysis. The cooling scheme is adequate for bending magnet beamlines at the ESRF and present wiggler beamlines at the SSRL.

Spring batch essentials

CERN Document Server

Rao, P Raja Malleswara

2015-01-01

If you are a Java developer with basic knowledge of Spring and some experience in the development of enterprise applications, and want to learn about batch application development in detail, then this book is ideal for you. This book will be perfect as your next step towards building simple yet powerful batch applications on a Java-based platform.

Three-body crystallization diagrams and the cooling of white dwarfs.

Science.gov (United States)

Segretain, L.

1996-06-01

The 3-body crystallization diagrams of C/O/Ne ionic mixtures characteristic of white dwarf interiors are examined within the framework of the density-functional theory of freezing. The crystallization process is described more accurately than in former calculations where the three-component system was treated as an effective two-component mixture (Segretain et al. 1994). The distillation process due to neon-crystallization is found to occur only for the late stages of crystallization. At the beginning, the presence of neon plays only a minor role and the phase diagram resembles a pure carbon-oxygen diagram. The final phase diagram is found to exhibit an azeotropic point with a neon concentration x_Ne_=0.22, a carbon concentration x_C_=0.78 and an oxygen concentration x_O_=0, so that during the distillation process, the fluid crystallizes into a pure neon-carbon solid. The critical temperature is T_A_=0.85T_C_, where T_C_ is the pure carbon crystallization temperature. We use this accurate phase diagram to calculate the total gravitational energy released during white dwarf crystallization and the related time delay. The final result yields {DELTA}τ=~2.6Gyr, among which about 20% are due to the neon-distillation process.

Characterization of ion Coulomb crystals in a linear Paul trap

International Nuclear Information System (INIS)

Okada, K.; Takayanagi, T.; Wada, M.; Ohtani, S.; Schuessler, H. A.

2010-01-01

We describe a simple and fast method for simulating observed images of ion Coulomb crystals. In doing so, cold elastic collisions between Coulomb crystals and virtual very light atoms are implemented in a molecular dynamics (MD) simulation code. Such an approach reproduces the observed images of Coulomb crystals by obtaining density plots of the statistics of existence of each ion. The simple method has the advantage of short computing time in comparison with previous calculation methods. As a demonstration of the simulation, the formation of a planar Coulomb crystal with a small number of ions has been investigated in detail in a linear ion trap both experimentally and by simulation. However, also large Coulomb crystals including up to 1400 ions have been photographed and simulated to extract the secular temperature and the number of ions. For medium-sized crystals, a comparison between experiments and calculations has been performed. Moreover, an MD simulation of the sympathetic cooling of small molecular ions was performed in order to test the possibility of extracting the temperature and the number of refrigerated molecular ions from crystal images of laser-cooled ions. Such information is basic to studying ultracold ion-molecule reactions using ion Coulomb crystals including sympathetically cooled molecular ions.

Characterization of a prototype batch of long polyimide cables designed for fast data transmission on ATLAS ITk strip staves

CERN Document Server

Dopke, Jens; The ATLAS collaboration; Sawyer, Craig; Sullivan, Stephanie W

2018-01-01

The silicon-strip system in the ATLAS ITk detector has individual sensor modules mounted on staves to provide integrated solution for mechanical support, power, cooling, and data transmission. The data and power are transmitted to individual modules on polyimide tapes placed on thermo-mechanical stave cores. The 1.4 m long tapes transmit module data at the rate of 640 Mbps, along with providing several multi-drop clock and command links, and power lines. The first batch of 25 tapes has been produced. We characterized the line impedance and its variation across the batch, examined the tape cross-section, and assessed the variation between design and fabrication.

Monte Carlo simulation on kinetics of batch and semi-batch free radical polymerization

KAUST Repository

Shao, Jing; Tang, Wei; Xia, Ru; Feng, Xiaoshuang; Chen, Peng; Qian, Jiasheng; Song, Changjiang

2015-01-01

experimental and simulation studies, we showed the capability of our Monte Carlo scheme on representing polymerization kinetics in batch and semi-batch processes. Various kinetics information, such as instant monomer conversion, molecular weight

Monte Carlo simulation on kinetics of batch and semi-batch free radical polymerization

KAUST Repository

Shao, Jing

2015-10-27

Based on Monte Carlo simulation technology, we proposed a hybrid routine which combines reaction mechanism together with coarse-grained molecular simulation to study the kinetics of free radical polymerization. By comparing with previous experimental and simulation studies, we showed the capability of our Monte Carlo scheme on representing polymerization kinetics in batch and semi-batch processes. Various kinetics information, such as instant monomer conversion, molecular weight, and polydispersity etc. are readily calculated from Monte Carlo simulation. The kinetic constants such as polymerization rate k p is determined in the simulation without of “steady-state” hypothesis. We explored the mechanism for the variation of polymerization kinetics those observed in previous studies, as well as polymerization-induced phase separation. Our Monte Carlo simulation scheme is versatile on studying polymerization kinetics in batch and semi-batch processes.

The contrasting roles of creep and stress relaxation in the time-dependent deformation during in-situ cooling of a nickel-base single crystal superalloy.

Science.gov (United States)

Panwisawas, Chinnapat; D'Souza, Neil; Collins, David M; Bhowmik, Ayan

2017-09-11

Time dependent plastic deformation in a single crystal nickel-base superalloy during cooling from casting relevant temperatures has been studied using a combination of in-situ neutron diffraction, transmission electron microscopy and modelling. Visco-plastic deformation during cooling was found to be dependent on the stress and constraints imposed to component contraction during cooling, which mechanistically comprises creep and stress relaxation. Creep results in progressive work hardening with dislocations shearing the γ' precipitates, a high dislocation density in the γ channels and near the γ/γ' interface and precipitate shearing. When macroscopic contraction is restricted, relaxation dominates. This leads to work softening from a decreased dislocation density and the presence of long segment stacking faults in γ phase. Changes in lattice strains occur to a similar magnitude in both the γ and γ' phases during stress relaxation, while in creep there is no clear monotonic trend in lattice strain in the γ phase, but only a marginal increase in the γ' precipitates. Using a visco-plastic law derived from in-situ experiments, the experimentally measured and calculated stresses during cooling show a good agreement when creep predominates. However, when stress relaxation dominates accounting for the decrease in dislocation density during cooling is essential.

Diffusion-Cooled Tantalum Hot-Electron Bolometer Mixers

Science.gov (United States)

Skalare, Anders; McGrath, William; Bumble, Bruce; LeDuc, Henry

2004-01-01

A batch of experimental diffusion-cooled hot-electron bolometers (HEBs), suitable for use as mixers having input frequencies in the terahertz range and output frequencies up to about a gigahertz, exploit the superconducting/normal-conducting transition in a thin strip of tantalum. The design and operation of these HEB mixers are based on mostly the same principles as those of a prior HEB mixer that exploited the superconducting/normal- conducting transition in a thin strip of niobium and that was described elsewhere.

Fast high-pressure freezing of protein crystals in their mother liquor

International Nuclear Information System (INIS)

Burkhardt, Anja; Warmer, Martin; Panneerselvam, Saravanan; Wagner, Armin; Zouni, Athina; Glöckner, Carina; Reimer, Rudolph; Hohenberg, Heinrich; Meents, Alke

2012-01-01

Protein crystals were vitrified using high-pressure freezing in their mother liquor at 210 MPa and 77 K without cryoprotectants or oil coating. The method was successfully applied to photosystem II, which is representative of a membrane protein with a large unit cell and weak crystal contacts. High-pressure freezing (HPF) is a method which allows sample vitrification without cryoprotectants. In the present work, protein crystals were cooled to cryogenic temperatures at a pressure of 210 MPa. In contrast to other HPF methods published to date in the field of cryocrystallography, this protocol involves rapid sample cooling using a standard HPF device. The fast cooling rates allow HPF of protein crystals directly in their mother liquor without the need for cryoprotectants or external reagents. HPF was first attempted with hen egg-white lysozyme and cubic insulin crystals, yielding good to excellent diffraction quality. Non-cryoprotected crystals of the membrane protein photosystem II have been successfully cryocooled for the first time. This indicates that the presented HPF method is well suited to the vitrification of challenging systems with large unit cells and weak crystal contacts

Workshop on beam cooling and related topics

International Nuclear Information System (INIS)

Bosser, J.

1994-01-01

The sessions of the Workshop on Beam Cooling and Related Topics, held in Montreux from 4-8 October 1993, are reported in these Proceedings. This meeting brought together international experts in the field of accelerator beam cooling. Its purpose was to discuss the status of the different cooling techniques currently in use (stochastic, electron, ionization, heavy-ion, and laser) and their actual performances, technological implications, and future prospects. Certain theoretical principles (muon cooling, cyclotron maser cooling) were discussed and are reported on in these Proceedings. Also of interest in this Workshop was the possibility of beam crystallization in accelerators using ultimate cooling. In the first part of these Proceedings, overview talks on the various cooling techniques, their implications, present performance, and future prospects are presented. More detailed reports on all the topics are then given in the form of oral presentations or poster sessions. Finally, the chairmen and/or convenors then present summary talks. (orig.)

Data-driven batch schuduling

Energy Technology Data Exchange (ETDEWEB)

Bent, John [Los Alamos National Laboratory; Denehy, Tim [GOOGLE; Arpaci - Dusseau, Remzi [UNIV OF WISCONSIN; Livny, Miron [UNIV OF WISCONSIN; Arpaci - Dusseau, Andrea C [NON LANL

2009-01-01

In this paper, we develop data-driven strategies for batch computing schedulers. Current CPU-centric batch schedulers ignore the data needs within workloads and execute them by linking them transparently and directly to their needed data. When scheduled on remote computational resources, this elegant solution of direct data access can incur an order of magnitude performance penalty for data-intensive workloads. Adding data-awareness to batch schedulers allows a careful coordination of data and CPU allocation thereby reducing the cost of remote execution. We offer here new techniques by which batch schedulers can become data-driven. Such systems can use our analytical predictive models to select one of the four data-driven scheduling policies that we have created. Through simulation, we demonstrate the accuracy of our predictive models and show how they can reduce time to completion for some workloads by as much as 80%.

Disinfection of bacterial biofilms in pilot-scale cooling tower systems.

Science.gov (United States)

Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron I

2011-04-01

The impact of continuous chlorination and periodic glutaraldehyde treatment on planktonic and biofilm microbial communities was evaluated in pilot-scale cooling towers operated continuously for 3 months. The system was operated at a flow rate of 10,080 l day(-1). Experiments were performed with a well-defined microbial consortium containing three heterotrophic bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. The persistence of each species was monitored in the recirculating cooling water loop and in biofilms on steel and PVC coupons in the cooling tower basin. The observed bacterial colonization in cooling towers did not follow trends in growth rates observed under batch conditions and, instead, reflected differences in the ability of each organism to remain attached and form biofilms under the high-through flow conditions in cooling towers. Flavobacterium was the dominant organism in the community, while P. aeruginosa and K. pneumoniae did not attach well to either PVC or steel coupons in cooling towers and were not able to persist in biofilms. As a result, the much greater ability of Flavobacterium to adhere to surfaces protected it from disinfection, whereas P. aeruginosa and K. pneumoniae were subject to rapid disinfection in the planktonic state.

A generic multi-dimensional model-based system for batch cooling crystallization processes

DEFF Research Database (Denmark)

Abdul Samad, Noor Asma Fazli; Singh, Ravendra; Sin, Gürkan

2011-01-01

Highly porous deposits of flame-made aerosol nanoparticles were formed by filtration through a porous substrate (α-alumina, average pore diameter 3.7 μm). The aerosol was characterized by transmission electron microscopy (TEM) and scanning mobility particle sizer (SMPS) showing average primary an...

Liquid metal cooling of synchrotron optics

International Nuclear Information System (INIS)

Smither, R.K.

1993-01-01

The installation of insertion devices at existing synchrotron facilities around the world has stimulated the development of new ways to cool the optical elements in the associated x-ray beamlines. Argonne has been a leader in the development of liquid metal cooling for high heat load x-ray optics for the next generation of synchrotron facilities. The high thermal conductivity, high volume specific heat, low kinematic viscosity, and large working temperature range make liquid metals a very efficient heat transfer fluid. A wide range of liquid metals were considered in the initial phase of this work. The most promising liquid metal cooling fluid identified to date is liquid gallium, which appears to have all the desired properties and the fewest number of undesired features of the liquid metals examined. Besides the special features of liquid metals that make them good heat transfer fluids, the very low vapor pressure over a large working temperature range make liquid gallium an ideal cooling fluid for use in a high vacuum environment. A leak of the liquid gallium into the high vacuum and even into very high vacuum areas will not result in any detectable vapor pressure and may even improve the vacuum environment as the liquid gallium combines with any water vapor or oxygen present in the system. The practical use of a liquid metal for cooling silicon crystals and other high heat load applications depends on having a convenient and efficient delivery system. The requirements for a typical cooling system for a silicon crystal used in a monochromator are pumping speeds of 2 to 5 gpm (120 cc per sec to 600 cc per sec) at pressures up to 100 psi. No liquid metal pump with these capabilities was available commercially when this project was started, so it was necessary to develop a suitable pump in house

Characteristics of bulk liquid undercooling and crystallization ...

Indian Academy of Sciences (India)

Characteristics of bulk liquid undercooling and crystallization behaviors ... cooling rate is fixed, the change of undercooling depends on the melt processing tem- ... solidification and a deep knowledge of undercooling of ... evolution, to obtain the information for the nucleation and ..... When cooling rate is fixed, the change.

Multicomponent Diffusion in Experimentally Cooled Melt Inclusions

Science.gov (United States)

Saper, L.; Stolper, E.

2017-12-01

Glassy olivine-hosted melt inclusions are compositionally zoned, characterized by a boundary layer depleted in olivine-compatible components that extends into the melt inclusion from its wall. The boundary layer forms in response to crystallization of olivine and relaxes with time due to diffusive exchange with the interior of the inclusion. At magmatic temperatures, the time scale for homogenization of inclusions is minutes to hours. Preservation of compositional gradients in natural inclusions results from rapid cooling upon eruption. A model of MgO concentration profiles that couples crystal growth and diffusive relaxation of a boundary layer can be used to solve for eruptive cooling rates [1]. Controlled cooling-rate experiments were conducted to test the accuracy of the model. Mauna Loa olivine containing >80 µm melt inclusions were equilibrated at 1225°C in a 1-atm furnace for 24 hours, followed by linear cooling at rates of 102 - 105 °C/hr. High-resolution concentration profiles of 40 inclusions were obtained using an electron microprobe. The model of [1] fits the experimental data with low residuals and the best-fit cooling rates are within 30% of experimental values. The initial temperature of 1225 °C is underestimated by 65°C. The model was modified using (i) MELTS to calculate the interface melt composition as a function of temperature, and (ii) a concentration-dependent MgO diffusion coefficient using the functional form of [2]. With this calibration the best-fit starting temperatures are within 5°C of the experimental values and the best-fit cooling rates are within 20% of experimental rates. The evolution of the CaO profile during cooling is evidence for strong diffusive coupling between melt components. Because CaO is incompatible in olivine, CaO concentrations are expected to be elevated in the boundary layer adjacent to the growing olivine. Although this is observed at short time scales, as the profile evolves the CaO concentration near the

Kinetic study of batch and fed-batch enzymatic saccharification of pretreated substrate and subsequent fermentation to ethanol

Directory of Open Access Journals (Sweden)

Gupta Rishi

2012-03-01

Full Text Available Abstract Background Enzymatic hydrolysis, the rate limiting step in the process development for biofuel, is always hampered by its low sugar concentration. High solid enzymatic saccharification could solve this problem but has several other drawbacks such as low rate of reaction. In the present study we have attempted to enhance the concentration of sugars in enzymatic hydrolysate of delignified Prosopis juliflora, using a fed-batch enzymatic hydrolysis approach. Results The enzymatic hydrolysis was carried out at elevated solid loading up to 20% (w/v and a comparison kinetics of batch and fed-batch enzymatic hydrolysis was carried out using kinetic regimes. Under batch mode, the actual sugar concentration values at 20% initial substrate consistency were found deviated from the predicted values and the maximum sugar concentration obtained was 80.78 g/L. Fed-batch strategy was implemented to enhance the final sugar concentration to 127 g/L. The batch and fed-batch enzymatic hydrolysates were fermented with Saccharomyces cerevisiae and ethanol production of 34.78 g/L and 52.83 g/L, respectively, were achieved. Furthermore, model simulations showed that higher insoluble solids in the feed resulted in both smaller reactor volume and shorter residence time. Conclusion Fed-batch enzymatic hydrolysis is an efficient procedure for enhancing the sugar concentration in the hydrolysate. Restricting the process to suitable kinetic regimes could result in higher conversion rates.

Kinetic study of batch and fed-batch enzymatic saccharification of pretreated substrate and subsequent fermentation to ethanol

Science.gov (United States)

2012-01-01

Background Enzymatic hydrolysis, the rate limiting step in the process development for biofuel, is always hampered by its low sugar concentration. High solid enzymatic saccharification could solve this problem but has several other drawbacks such as low rate of reaction. In the present study we have attempted to enhance the concentration of sugars in enzymatic hydrolysate of delignified Prosopis juliflora, using a fed-batch enzymatic hydrolysis approach. Results The enzymatic hydrolysis was carried out at elevated solid loading up to 20% (w/v) and a comparison kinetics of batch and fed-batch enzymatic hydrolysis was carried out using kinetic regimes. Under batch mode, the actual sugar concentration values at 20% initial substrate consistency were found deviated from the predicted values and the maximum sugar concentration obtained was 80.78 g/L. Fed-batch strategy was implemented to enhance the final sugar concentration to 127 g/L. The batch and fed-batch enzymatic hydrolysates were fermented with Saccharomyces cerevisiae and ethanol production of 34.78 g/L and 52.83 g/L, respectively, were achieved. Furthermore, model simulations showed that higher insoluble solids in the feed resulted in both smaller reactor volume and shorter residence time. Conclusion Fed-batch enzymatic hydrolysis is an efficient procedure for enhancing the sugar concentration in the hydrolysate. Restricting the process to suitable kinetic regimes could result in higher conversion rates. PMID:22433563

BATCH-GE: Batch analysis of Next-Generation Sequencing data for genome editing assessment

Science.gov (United States)

Boel, Annekatrien; Steyaert, Woutert; De Rocker, Nina; Menten, Björn; Callewaert, Bert; De Paepe, Anne; Coucke, Paul; Willaert, Andy

2016-01-01

Targeted mutagenesis by the CRISPR/Cas9 system is currently revolutionizing genetics. The ease of this technique has enabled genome engineering in-vitro and in a range of model organisms and has pushed experimental dimensions to unprecedented proportions. Due to its tremendous progress in terms of speed, read length, throughput and cost, Next-Generation Sequencing (NGS) has been increasingly used for the analysis of CRISPR/Cas9 genome editing experiments. However, the current tools for genome editing assessment lack flexibility and fall short in the analysis of large amounts of NGS data. Therefore, we designed BATCH-GE, an easy-to-use bioinformatics tool for batch analysis of NGS-generated genome editing data, available from https://github.com/WouterSteyaert/BATCH-GE.git. BATCH-GE detects and reports indel mutations and other precise genome editing events and calculates the corresponding mutagenesis efficiencies for a large number of samples in parallel. Furthermore, this new tool provides flexibility by allowing the user to adapt a number of input variables. The performance of BATCH-GE was evaluated in two genome editing experiments, aiming to generate knock-out and knock-in zebrafish mutants. This tool will not only contribute to the evaluation of CRISPR/Cas9-based experiments, but will be of use in any genome editing experiment and has the ability to analyze data from every organism with a sequenced genome. PMID:27461955

Monolithic I-Beam Crystal Monochromator

Energy Technology Data Exchange (ETDEWEB)

Bagnasco, John

2001-10-16

Curved crystal, focusing monochromators featuring cubed-root thickness profiles typically employ side-clamped cooling to reduce thermally induced overall bend deformation of the crystal. While performance is improved, residual bend deformation is often an important limiting factor in the monochromator performance. A slightly asymmetric ``I-beam'' crystal cross section with cubed-root flange profiles has been developed to further reduce this effect. Physical motivation, finite-element modeling evaluation and performance characteristics of this design are discussed. Reduction of high mounting stress at the fixed end of the crystal required the soldering of an Invar support fixture to the crystal. Detailed descriptions of this process along with its performance characteristics are also presented.

Mathematical modeling of static layer crystallization for propellant grade hydrogen peroxide

Science.gov (United States)

Hao, Lin; Chen, Xinghua; Sun, Yaozhou; Liu, Yangyang; Li, Shuai; Zhang, Mengqian

2017-07-01

Hydrogen peroxide (H2O2) is an important raw material widely used in many fields. In this work a mathematical model of heat conduction with a moving boundary was proposed to study the melt crystallization process of hydrogen peroxide which was carried out outside a cylindrical crystallizer. Considering the effects of the temperature of the cooling fluid on the thermal conductivity of crude crystal, the model is an improvement of Guardani's research and can be solved by analytic iteration method. An experiment was designed to measure the thickness of crystal layer with time under different conditions. A series of analysis, including the effects of different refrigerant temperature on crystal growth rate, the effects of different cooling rates on crystal layer growth rate, the effects of crystallization temperature on heat transfer and the model's application scope were conducted based on the comparison between experimental results and simulation results of the model.

Optimization of anisotropic photonic density of states for Raman cooling of solids

Science.gov (United States)

Chen, Yin-Chung; Ghosh, Indronil; Schleife, André; Carney, P. Scott; Bahl, Gaurav

2018-04-01

Optical refrigeration of solids holds tremendous promise for applications in thermal management. It can be achieved through multiple mechanisms including inelastic anti-Stokes Brillouin and Raman scattering. However, engineering of these mechanisms remains relatively unexplored. The major challenge lies in the natural unfavorable imbalance in transition rates for Stokes and anti-Stokes scattering. We consider the influence of anisotropic photonic density of states on Raman scattering and derive expressions for cooling in such photonically anisotropic systems. We demonstrate optimization of the Raman cooling figure of merit considering all possible orientations for the material crystal and two example photonic crystals. We find that the anisotropic description of the photonic density of states and the optimization process is necessary to obtain the best Raman cooling efficiency for systems having lower symmetry. This general result applies to a wide array of other laser cooling methods in the presence of anisotropy.

Medication waste reduction in pediatric pharmacy batch processes.

Science.gov (United States)

Toerper, Matthew F; Veltri, Michael A; Hamrock, Eric; Mollenkopf, Nicole L; Holt, Kristen; Levin, Scott

2014-04-01

To inform pediatric cart-fill batch scheduling for reductions in pharmaceutical waste using a case study and simulation analysis. A pre and post intervention and simulation analysis was conducted during 3 months at a 205-bed children's center. An algorithm was developed to detect wasted medication based on time-stamped computerized provider order entry information. The algorithm was used to quantify pharmaceutical waste and associated costs for both preintervention (1 batch per day) and postintervention (3 batches per day) schedules. Further, simulation was used to systematically test 108 batch schedules outlining general characteristics that have an impact on the likelihood for waste. Switching from a 1-batch-per-day to a 3-batch-per-day schedule resulted in a 31.3% decrease in pharmaceutical waste (28.7% to 19.7%) and annual cost savings of $183,380. Simulation results demonstrate how increasing batch frequency facilitates a more just-in-time process that reduces waste. The most substantial gains are realized by shifting from a schedule of 1 batch per day to at least 2 batches per day. The simulation exhibits how waste reduction is also achievable by avoiding batch preparation during daily time periods where medication administration or medication discontinuations are frequent. Last, the simulation was used to show how reducing batch preparation time per batch provides some, albeit minimal, opportunity to decrease waste. The case study and simulation analysis demonstrate characteristics of batch scheduling that may support pediatric pharmacy managers in redesign toward minimizing pharmaceutical waste.

Batch-to-batch quality consistency evaluation of botanical drug products using multivariate statistical analysis of the chromatographic fingerprint.

Science.gov (United States)

Xiong, Haoshu; Yu, Lawrence X; Qu, Haibin

2013-06-01

Botanical drug products have batch-to-batch quality variability due to botanical raw materials and the current manufacturing process. The rational evaluation and control of product quality consistency are essential to ensure the efficacy and safety. Chromatographic fingerprinting is an important and widely used tool to characterize the chemical composition of botanical drug products. Multivariate statistical analysis has showed its efficacy and applicability in the quality evaluation of many kinds of industrial products. In this paper, the combined use of multivariate statistical analysis and chromatographic fingerprinting is presented here to evaluate batch-to-batch quality consistency of botanical drug products. A typical botanical drug product in China, Shenmai injection, was selected as the example to demonstrate the feasibility of this approach. The high-performance liquid chromatographic fingerprint data of historical batches were collected from a traditional Chinese medicine manufacturing factory. Characteristic peaks were weighted by their variability among production batches. A principal component analysis model was established after outliers were modified or removed. Multivariate (Hotelling T(2) and DModX) control charts were finally successfully applied to evaluate the quality consistency. The results suggest useful applications for a combination of multivariate statistical analysis with chromatographic fingerprinting in batch-to-batch quality consistency evaluation for the manufacture of botanical drug products.

Cadmium removal using Cladophora in batch, semi-batch and flow reactors.

Science.gov (United States)

Sternberg, Steven P K; Dorn, Ryan W

2002-02-01

This study presents the results of using viable algae to remove cadmium from a synthetic wastewater. In batch and semi-batch tests, a local strain of Cladophora algae removed 80-94% of the cadmium introduced. The flow experiments that followed were conducted using non-local Cladophora parriaudii. Results showed that the alga removed only 12.7(+/-6.4)% of the cadmium introduced into the reactor. Limited removal was the result of insufficient algal quantities and poor contact between the algae and cadmium solution.

Kubernetes as a batch scheduler

OpenAIRE

Souza, Clenimar; Brito Da Rocha, Ricardo

2017-01-01

This project aims at executing a CERN batch use case using Kubernetes, in order to figure out what are the advantages and disadvantages, as well as the functionality that can be replicated or is missing. The reference for the batch system is the CERN Batch System, which uses HTCondor. Another goal of this project is to evaluate the current status of federated resources in Kubernetes, in comparison to the single-cluster API resources. Finally, the last goal of this project is to implement buil...

Crystallization of Trehalose in Frozen Solutions and its Phase Behavior during Drying

Energy Technology Data Exchange (ETDEWEB)

Sundaramurthi, Prakash; Patapoff, Thomas W.; Suryanarayanan, Raj (Genentech); (UMM)

2015-02-19

To study the crystallization of trehalose in frozen solutions and to understand the phase transitions during the entire freeze-drying cycle. Aqueous trehalose solution was cooled to -40 C in a custom-designed sample holder. The frozen solution was warmed to -18 C and annealed, and then dried in the sample chamber of the diffractometer. XRD patterns were continuously collected during cooling, annealing and drying. After cooling, hexagonal ice was the only crystalline phase observed. However, upon annealing, crystallization of trehalose dihydrate was evident. Seeding the frozen solution accelerated the solute crystallization. Thus, phase separation of the lyoprotectant was observed in frozen solutions. During drying, dehydration of trehalose dihydrate yielded a substantially amorphous anhydrous trehalose. Crystallization of trehalose, as trehalose dihydrate, was observed in frozen solutions. The dehydration of the crystalline trehalose dihydrate to substantially amorphous anhydrate occurred during drying. Therefore, analyzing the final lyophile will not reveal crystallization of the lyoprotectant during freeze-drying. The lyoprotectant crystallization can only become evident by continuous monitoring of the system during the entire freeze-drying cycle. In light of the phase separation of trehalose in frozen solutions, its ability to serve as a lyoprotectant warrants further investigation.

Operation condition for continuous anti-solvent crystallization of CBZ-SAC cocrystal considering deposition risk of undesired crystals

Science.gov (United States)

Nishimaru, Momoko; Nakasa, Miku; Kudo, Shoji; Takiyama, Hiroshi

2017-07-01

Crystallization operation of cocrystal production has deposition risk of undesired crystals. Simultaneously, continuous manufacturing processes are focused on. In this study, conditions for continuous cocrystallization considering risk reduction of undesired crystals deposition were investigated on the view point of thermodynamics and kinetics. The anti-solvent cocrystallization was carried out in four-component system of carbamazepine, saccharin, methanol and water. From the preliminary batch experiment, the relationships among undesired crystal deposition, solution composition decided by mixing ratio of solutions, and residence time for the crystals were considered, and then the conditions of continuous experiment were decided. Under these conditions, the continuous experiment was carried out. The XRD patterns of obtained crystals in the continuous experiment showed that desired cocrystals were obtained without undesired crystals. This experimental result was evaluated by using multi-component phase diagrams from the view point of the operation point's movement. From the evaluation, it was found that there is a certain operation condition which the operation point is fixed with time in the specific domain without the deposition risk of undesired single component crystals. It means the possibility of continuous production of cocrystals without deposition risk of undesired crystals was confirmed by using multi-component phase diagrams.

BatchJS: Implementing Batches in JavaScript

NARCIS (Netherlands)

D. Kasemier

2014-01-01

htmlabstractNone of our popular programming languages know how to handle distribution well. Yet our programs interact more and more with each other and our data resorts in databases and web services. Batches are a new addition to languages that can finally bring native support for distribution to

Batch-to-batch uniformity of bacterial community succession and flavor formation in the fermentation of Zhenjiang aromatic vinegar.

Science.gov (United States)

Wang, Zong-Min; Lu, Zhen-Ming; Yu, Yong-Jian; Li, Guo-Quan; Shi, Jin-Song; Xu, Zheng-Hong

2015-09-01

Solid-state fermentation of traditional Chinese vinegar is a mixed-culture refreshment process that proceeds for many centuries without spoilage. Here, we investigated bacterial community succession and flavor formation in three batches of Zhenjiang aromatic vinegar using pyrosequencing and metabolomics approaches. Temporal patterns of bacterial succession in the Pei (solid-state vinegar culture) showed no significant difference (P > 0.05) among three batches of fermentation. In all the batches investigated, the average number of community operational taxonomic units (OTUs) decreased dramatically from 119 ± 11 on day 1 to 48 ± 16 on day 3, and then maintained in the range of 61 ± 9 from day 5 to the end of fermentation. We confirmed that, within a batch of fermentation process, the patterns of bacterial diversity between the starter (took from the last batch of vinegar culture on day 7) and the Pei on day 7 were similar (90%). The relative abundance dynamics of two dominant members, Lactobacillus and Acetobacter, showed high correlation (coefficient as 0.90 and 0.98 respectively) among different batches. Furthermore, statistical analysis revealed dynamics of 16 main flavor metabolites were stable among different batches. The findings validate the batch-to-batch uniformity of bacterial community succession and flavor formation accounts for the quality of Zhenjiang aromatic vinegar. Based on our understanding, this is the first study helps to explain the rationality of age-old artistry from a scientific perspective. Copyright © 2015 Elsevier Ltd. All rights reserved.

Liquid nitrogen dewar for protein crystal growth

Science.gov (United States)

2001-01-01

Gaseous Nitrogen Dewar apparatus developed by Dr. Alex McPherson of the University of California, Irvine for use aboard Mir and the International Space Station allows large quantities of protein samples to be crystallized in orbit. The specimens are contained either in plastic tubing (heat-sealed at each end). Biological samples are prepared with a precipitating agent in either a batch or liquid-liquid diffusion configuration. The samples are then flash-frozen in liquid nitrogen before crystallization can start. On orbit, the Dewar is placed in a quiet area of the station and the nitrogen slowly boils off (it is taken up by the environmental control system), allowing the proteins to thaw to begin crystallization. The Dewar is returned to Earth after one to four months on orbit, depending on Shuttle flight opportunities. The tubes then are analyzed for crystal presence and quality

Production of ethanol in batch and fed-batch fermentation of soluble sugar

International Nuclear Information System (INIS)

Chaudhary, M.Y.; Shah, M.A.; Shah, F.H.

1991-01-01

Keeping in view of the demand and need for alternate energy source, especially liquid fuels and the availability of raw materials in Pakistan, we have carried out biochemical and technological studies for ethanol through fermentation of renewable substrates. Molasses and sugar cane have been used as substrate for yeast fermentation. Selected yeast were used in both batch and semi continuous fermentation of molasses. Clarified dilute molasses were fermented with different strains of Saccharomyces cerevisiae. Ethanol concentration after 64 hours batch fermentation reached 9.4% with 90% yield based on sugar content. During feed batch system similar results were obtained after a fermentation cycle of 48 hours resulting in higher productivity. Similarly carbohydrates in fruit juices and hydro lysates of biomass can be economically fermented to ethanol to be used as feed stock for other chemicals. (author)

Commensurability oscillations in NdBa2Cu3Oy single crystals

Indian Academy of Sciences (India)

Postfach 3640, 76021 Karlsruhe, Germany. 2Technical ... the vortices are placed between the CuO2 layers, but the energy necessary for the elastic ... Two Nd123 crystals from the same batch were investigated: FK, twinned, transition tem-.

Batch-batch stable microbial community in the traditional fermentation process of huyumei broad bean pastes.

Science.gov (United States)

Zhu, Linjiang; Fan, Zihao; Kuai, Hui; Li, Qi

2017-09-01

During natural fermentation processes, a characteristic microbial community structure (MCS) is naturally formed, and it is interesting to know about its batch-batch stability. This issue was explored in a traditional semi-solid-state fermentation process of huyumei, a Chinese broad bean paste product. The results showed that this MCS mainly contained four aerobic Bacillus species (8 log CFU per g), including B. subtilis, B. amyloliquefaciens, B. methylotrophicus, and B. tequilensis, and the facultative anaerobe B. cereus with a low concentration (4 log CFU per g), besides a very small amount of the yeast Zygosaccharomyces rouxii (2 log CFU per g). The dynamic change of the MCS in the brine fermentation process showed that the abundance of dominant species varied within a small range, and in the beginning of process the growth of lactic acid bacteria was inhibited and Staphylococcus spp. lost its viability. Also, the MCS and its dynamic change were proved to be highly reproducible among seven batches of fermentation. Therefore, the MCS naturally and stably forms between different batches of the traditional semi-solid-state fermentation of huyumei. Revealing microbial community structure and its batch-batch stability is helpful for understanding the mechanisms of community formation and flavour production in a traditional fermentation. This issue in a traditional semi-solid-state fermentation of huyumei broad bean paste was firstly explored. This fermentation process was revealed to be dominated by a high concentration of four aerobic species of Bacillus, a low concentration of B. cereus and a small amount of Zygosaccharomyces rouxii. Lactic acid bacteria and Staphylococcus spp. lost its viability at the beginning of fermentation. Such the community structure was proved to be highly reproducible among seven batches. © 2017 The Society for Applied Microbiology.

Incorporation of cooling-induced crystallisation into a 2-dimensional axisymmetric conduit heat flow model

Science.gov (United States)

Heptinstall, D. A.; Neuberg, J. W.; Bouvet de Maisonneuve, C.; Collinson, A.; Taisne, B.; Morgan, D. J.

2015-12-01

Heat flow models can bring new insights into the thermal and rheological evolution of volcanic systems. We shall investigate the thermal processes and timescales in a crystallizing, static magma column, with a heat flow model of Soufriere Hills Volcano (SHV), Montserrat. The latent heat of crystallization is initially computed with MELTS, as a function of pressure and temperature for an andesitic melt (SHV groundmass starting composition). Three fractional crystallization simulations are performed; two with initial pressures of 34MPa (runs 1 & 2) and one of 25MPa (run 3). Decompression rate was varied between 0.1MPa/°C (runs 1 & 3) and 0.2MPa/°C (run 2). Natural and experimental matrix glass compositions are accurately reproduced by all MELTS runs. The cumulative latent heat released for runs 1, 2 and 3 differs by less than 9% (8.69e5 J/kg*K, 9.32e5 J/kg*K, and 9.49e5 J/kg*K respectively). The 2D axisymmetric conductive cooling simulations consider a 30m-diameter conduit that extends from the surface to a depth of 1500m (34MPa). The temporal evolution of temperature is closely tracked at depths of 10m, 750m and 1400m in the center of the conduit, at the conduit walls, and 20m from the walls into the host rock. Following initial cooling by 7-15oC at 10m depth inside the conduit, the magma temperature rebounds through latent heat release by 32-35oC over 85-123 days to a maximum temperature of 1002-1005oC. At 10 m depth, it takes 4.1-9.2 years for the magma column to cool over 108-130oC and crystallize to 75wt%, at which point it cannot be easily remobilized. It takes 11-31.5 years to reach the same crystallinity at 750-1400m depth. We find a wide range in cooling timescales, particularly at depths of 750m or greater, attributed to the initial run pressure and dominant latent heat producing crystallizing phases (Quartz), where run 1 cools fastest and run 3 cools slowest. Surface cooling by comparison has the strongest influence on the upper tens of meters in all

Crystallization and properties of a spodumene-willemite glass ceramic

International Nuclear Information System (INIS)

Hu, A.M.; Li, M.; Dali, D.L. Mao; Liang, K.M.

2005-01-01

Spodumene-willemite glass ceramics were produced by replacement of Al 2 O 3 in lithium aluminium silicate by ZnO. With replacement of Al 2 O 3 by ZnO, the batch melting temperature, glass transition temperature (T g ) and crystallization temperature (T p ) all decreased. The main crystalline phases precipitated were eucriptite, β-spodumene and willemite (Zn 2 SiO 4 ). All compositions of glass ceramics showed bulk crystallization. As ZnO content increased, the grain sizes and thermal expansion coefficients increased, while the flexural strength and fracture toughness of the glass-ceramics increased first, and then decreased. The mechanical properties were correlated with crystallization and morphology of glass ceramics

Crystal Nucleation Using Surface-Energy-Modified Glass Substrates.

Science.gov (United States)

Nordquist, Kyle A; Schaab, Kevin M; Sha, Jierui; Bond, Andrew H

2017-08-02

Systematic surface energy modifications to glass substrates can induce nucleation and improve crystallization outcomes for small molecule active pharmaceutical ingredients (APIs) and proteins. A comparatively broad probe for function is presented in which various APIs, proteins, organic solvents, aqueous media, surface energy motifs, crystallization methods, form factors, and flat and convex surface energy modifications were examined. Replicate studies ( n ≥ 6) have demonstrated an average reduction in crystallization onset times of 52(4)% (alternatively 52 ± 4%) for acetylsalicylic acid from 91% isopropyl alcohol using two very different techniques: bulk cooling to 0 °C using flat surface energy modifications or microdomain cooling to 4 °C from the interior of a glass capillary having convex surface energy modifications that were immersed in the solution. For thaumatin and bovine pancreatic trypsin, a 32(2)% reduction in crystallization onset times was demonstrated in vapor diffusion experiments ( n ≥ 15). Nucleation site arrays have been engineered onto form factors frequently used in crystallization screening, including microscope slides, vials, and 96- and 384-well high-throughput screening plates. Nucleation using surface energy modifications on the vessels that contain the solutes to be crystallized adds a layer of useful variables to crystallization studies without requiring significant changes to workflows or instrumentation.

Magma oceanography. II - Chemical evolution and crustal formation. [lunar crustal rock fractional crystallization model

Science.gov (United States)

Longhi, J.

1977-01-01

A description is presented of an empirical model of fractional crystallization which predicts that slightly modified versions of certain of the proposed whole moon compositions can reproduce the major-element chemistry and mineralogy of most of the primitive highland rocks through equilibrium and fractional crystallization processes combined with accumulation of crystals and trapping of residual liquids. These compositions contain sufficient Al to form a plagioclase-rich crust 60 km thick on top of a magma ocean that was initially no deeper than about 300 km. Implicit in the model are the assumptions that all cooling and crystallization take place at low pressure and that there are no compositional or thermal gradients in the liquid. Discussions of the cooling and crystallization of the proposed magma ocean show these assumptions to be disturbingly naive when applied to the ocean as a whole. However, the model need not be applied to the whole ocean, but only to layers of cooling liquid near the surface.

Multi-objective optimization of glycopeptide antibiotic production in batch and fed batch processes

DEFF Research Database (Denmark)

Maiti, Soumen K.; Eliasson Lantz, Anna; Bhushan, Mani

2011-01-01

batch operations using process model for Amycolatopsis balhimycina, a glycopeptide antibiotic producer. This resulted in a set of several pareto optimal solutions with the two objectives ranging from (0.75gl−1, 3.97g$-1) to (0.44gl−1, 5.19g$-1) for batch and from (1.5gl−1, 5.46g$-1) to (1.1gl−1, 6.34g...

Detection of gas-permeable fuel particles for highl 7490 temperature gas-cooled reactors

International Nuclear Information System (INIS)

Thiele, B.A.; Stinton, D.P.; Costanzo, D.A.

1980-01-01

Fuel for High-Temperature Gas-Cooled Reactors (HTGR) consists of uranium oxide-carbide and thoria microspheres coated with layers of pyrolytic carbon and silicon carbide. The pyrolytic carbon coatings must be gas-tight to perform properly during irradiation. Therefore, particles must be carefully characterized to determine the number of defective particles (ie bare kernels, and cracked or permeable coatings). Although techniques are available to determine the number of bare kernels or cracked coatings, no reliable technique has been available to measure coating permeability. This work describes a technique recently developed to determine whether coatings for a batch of particles are gas-tight or permeable. Although most of this study was performed on Biso-coated particles, the technique applies equally well to Triso-coated particles. About 150 randomly selected Biso-particle batches were studied in this work. These batches were first subjected to an 18-hr chlorination at 15000C, and the volatile thorium tetrachloride released through cracked or very permeable coatings was measured versus chlorination time. Chlorinated batches were also radiographed to detect any thorium that had migrated from the kernel into the coatings. From this work a technique was developed to determine coating permeability. This consists of an 18-hr chlorination of multiple samples without measurement of the heavy metal released. Each batch is then radiographed and the heavy metal diffusion within each particle is examined so it can be determined if a particle batch is permeable, slightly permeable, or gas-tight. (author)

Design of two-column batch-to-batch recirculation to enhance performance in ion-exchange chromatography.

Science.gov (United States)

Persson, Oliver; Andersson, Niklas; Nilsson, Bernt

2018-01-05

Preparative liquid chromatography is a separation technique widely used in the manufacturing of fine chemicals and pharmaceuticals. A major drawback of traditional single-column batch chromatography step is the trade-off between product purity and process performance. Recirculation of impure product can be utilized to make the trade-off more favorable. The aim of the present study was to investigate the usage of a two-column batch-to-batch recirculation process step to increase the performance compared to single-column batch chromatography at a high purity requirement. The separation of a ternary protein mixture on ion-exchange chromatography columns was used to evaluate the proposed process. The investigation used modelling and simulation of the process step, experimental validation and optimization of the simulated process. In the presented case the yield increases from 45.4% to 93.6% and the productivity increases 3.4 times compared to the performance of a batch run for a nominal case. A rapid concentration build-up product can be seen during the first cycles, before the process reaches a cyclic steady-state with reoccurring concentration profiles. The optimization of the simulation model predicts that the recirculated salt can be used as a flying start of the elution, which would enhance the process performance. The proposed process is more complex than a batch process, but may improve the separation performance, especially while operating at cyclic steady-state. The recirculation of impure fractions reduces the product losses and ensures separation of product to a high degree of purity. Copyright © 2017 Elsevier B.V. All rights reserved.

Phosphorus zoning as a recorder of crystal growth kinetics

DEFF Research Database (Denmark)

Baziotis, I.; Asimow, P.D.; Ntaflos, T.

2017-01-01

spectrometry. The petrogenetic history of each vein involves melt intrusion, cooling accompanied by both wall-rock reaction and crystallization, quench of melt to a glass, and possibly later modifications. Exotic secondary olivine crystals in the veins display concentric phosphorus (P)-rich zoning, P...

7 CFR 58.728 - Cooking the batch.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Cooking the batch. 58.728 Section 58.728 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.728 Cooking the batch. Each batch of cheese within the cooker, including the optional...

NGBAuth - Next Generation Batch Authentication for long running batch jobs.

CERN Document Server

Juto, Zakarias

2015-01-01

This document describes the prototyping of a new solution for the CERN batch authentication of long running jobs. While the job submission requires valid user credentials, these have to be renewed due to long queuing and execution times. Described within is a new system which will guarantee a similar level of security as the old LSFAuth while simplifying the implementation and the overall architecture. The new system is being built on solid, streamlined and tested components (notably OpenSSL) and a priority has been to make it more generic in order to facilitate the evolution of the current system such as for the expected migration from LSF to Condor as backend batch system.

Lab-on-a-Chip Based Protein Crystallization

Science.gov (United States)

vanderWoerd, Mark J.; Brasseur, Michael M.; Spearing, Scott F.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

We are developing a novel technique with which we will grow protein crystals in very small volumes, utilizing chip-based, microfluidic ("LabChip") technology. This development, which is a collaborative effort between NASA's Marshall Space Flight Center and Caliper Technologies Corporation, promises a breakthrough in the field of protein crystal growth. Our initial results obtained from two model proteins, Lysozyme and Thaumatin, show that it is feasible to dispense and adequately mix protein and precipitant solutions on a nano-liter scale. The mixtures have shown crystal growth in volumes in the range of 10 nanoliters to 5 microliters. In addition, large diffraction quality crystals were obtained by this method. X-ray data from these crystals were shown to be of excellent quality. Our future efforts will include the further development of protein crystal growth with LabChip(trademark) technology for more complex systems. We will initially address the batch growth method, followed by the vapor diffusion method and the liquid-liquid diffusion method. The culmination of these chip developments is to lead to an on orbit protein crystallization facility on the International Space Station. Structural biologists will be invited to utilize the on orbit Iterative Biological Crystallization facility to grow high quality macromolecular crystals in microgravity.

Substantial increase in acceleration potential of pyroelectric crystals

International Nuclear Information System (INIS)

Tornow, W.; Lynam, S. M.; Shafroth, S. M.

2010-01-01

We report on a substantial increase in the acceleration potential achieved with a LiTaO 3 pyroelectric crystal. With a single 2.5 cm diameter and 2.5 cm long z-cut crystal without electric field-enhancing nanotip we produced positive ion beams with maximal energies between 300 and 310 keV during the cooling phase when the crystal was exposed to 5 mTorr of deuterium gas. These values are about a factor of 2 larger than previously obtained with single pyroelectric crystals.

Dendritic microstructure and hot cracking of laser additive manufactured Inconel 718 under improved base cooling

Energy Technology Data Exchange (ETDEWEB)

Chen, Yuan; Lu, Fenggui; Zhang, Ke; Nie, Pulin; Elmi Hosseini, Seyed Reza; Feng, Kai, E-mail: fengkai@sjtu.edu.cn; Li, Zhuguo, E-mail: lizg@sjtu.edu.cn

2016-06-15

The base cooling effect was improved by imposing the continuous water flow on the back of the substrate during the laser additive manufacturing of Inconel 718 (IN718). The dendritic microstructure, crystal orientation and hot cracking behavior were studied by using optical microscopy (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) techniques. The results showed that the crystal orientation was increased by increasing the base cooling effect during the deposition. Also, highly ordered columnar dendrites were established, and mono-crystalline texture was constructed in the final clad. It was fund that the effect of solidification cracking on the properties of final clad was negligible since it was only generated at the top region of the deposit, while liquation cracking was produced and remained in the heat affected zone (HAZ) and needed to be carefully controlled. The susceptibility to the liquation cracking showed a high dependence on the grain boundary misorientation, which was considered to be attributed to the stability of interdendritic liquation films, as well as the magnitude of local stress concentration in the last stage of solidification. - Highlights: • The base cooling effect was increased during laser additive manufacturing. • Highly ordered dendrites were established under improved base cooling. • The crystal orientation was increased by improving the base cooling effect. • Liquation cracking tendency was reduced due to the increase of base cooling. • Liquation cracking increased with the increase of grain boundary misorientation.

Dendritic microstructure and hot cracking of laser additive manufactured Inconel 718 under improved base cooling

International Nuclear Information System (INIS)

Chen, Yuan; Lu, Fenggui; Zhang, Ke; Nie, Pulin; Elmi Hosseini, Seyed Reza; Feng, Kai; Li, Zhuguo

2016-01-01

The base cooling effect was improved by imposing the continuous water flow on the back of the substrate during the laser additive manufacturing of Inconel 718 (IN718). The dendritic microstructure, crystal orientation and hot cracking behavior were studied by using optical microscopy (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) techniques. The results showed that the crystal orientation was increased by increasing the base cooling effect during the deposition. Also, highly ordered columnar dendrites were established, and mono-crystalline texture was constructed in the final clad. It was fund that the effect of solidification cracking on the properties of final clad was negligible since it was only generated at the top region of the deposit, while liquation cracking was produced and remained in the heat affected zone (HAZ) and needed to be carefully controlled. The susceptibility to the liquation cracking showed a high dependence on the grain boundary misorientation, which was considered to be attributed to the stability of interdendritic liquation films, as well as the magnitude of local stress concentration in the last stage of solidification. - Highlights: • The base cooling effect was increased during laser additive manufacturing. • Highly ordered dendrites were established under improved base cooling. • The crystal orientation was increased by improving the base cooling effect. • Liquation cracking tendency was reduced due to the increase of base cooling. • Liquation cracking increased with the increase of grain boundary misorientation.

NDA BATCH 2002-02

Energy Technology Data Exchange (ETDEWEB)

Lawrence Livermore National Laboratory

2009-12-09

QC sample results (daily background checks, 20-gram and 100-gram SGS drum checks) were within acceptable criteria established by WIPP's Quality Assurance Objectives for TRU Waste Characterization. Replicate runs were performed on 5 drums with IDs LL85101099TRU, LL85801147TRU, LL85801109TRU, LL85300999TRU and LL85500979TRU. All replicate measurement results are identical at the 95% confidence level as established by WIPP criteria. Note that the batch covered 5 weeks of SGS measurements from 23-Jan-2002 through 22-Feb-2002. Data packet for SGS Batch 2002-02 generated using gamma spectroscopy with the Pu Facility SGS unit is technically reasonable. All QC samples are in compliance with established control limits. The batch data packet has been reviewed for correctness, completeness, consistency and compliance with WIPP's Quality Assurance Objectives and determined to be acceptable. An Expert Review was performed on the data packet between 28-Feb-02 and 09-Jul-02 to check for potential U-235, Np-237 and Am-241 interferences and address drum cases where specific scan segments showed Se gamma ray transmissions for the 136-keV gamma to be below 0.1 %. Two drums in the batch showed Pu-238 at a relative mass ratio more than 2% of all the Pu isotopes.

Time measurements for thermalequilibrium in spodumene crystals

International Nuclear Information System (INIS)

Fujii, A.T.; Isotani, S.

1982-01-01

Experiments for measurement of time taken to reach thermal equilibrium in Spodumene crystals - 2mm to 5,4mm thick - in the temperature range 100 0 to 250 0 C are described. The measurements indicate a linear relationship between time and thickenes for heating as well as for cooling. Difference in thermal equilibrium time for heating and for cooling is about of 20 seconds. (author) [pt

Cryogenics for the MuCool Test Area (MTA)

International Nuclear Information System (INIS)

Darve, Christine; Norris, Barry; Pei, Liujin

2006-01-01

MuCool Test Area (MTA) is a complex of buildings at Fermi National Accelerator Laboratory, which are dedicated to operate components of a cooling cell to be used for Muon Collider and Neutrino Factory R and D. The long-term goal of this facility is to test ionization cooling principles by operating a 25-liter liquid hydrogen (LH2) absorber embedded in a 5 Tesla superconducting solenoid magnet. The MTA solenoid magnet will be used with RF cavities exposed to a high intensity beam. Cryogens used at the MTA include LHe, LN2 and LH2. The latter dictates stringent system design for hazardous locations. The cryogenic plant is a modified Tevatron refrigerator based on the Claude cycle. The implementation of an in-house refrigerator system and two 300 kilowatt screw compressors is under development. The helium refrigeration capacity is 500 W at 14 K. In addition the MTA solenoid magnet will be batch-filled with LHe every 2 days using the same cryo-plant. This paper reviews cryogenic systems used to support the Muon Collider and Neutrino Factory R and D programs and emphasizes the feasibility of handling cryogenic equipment at MTA in a safe manner

Bioprocess iterative batch-to-batch optimization based on hybrid parametric/nonparametric models.

Science.gov (United States)

Teixeira, Ana P; Clemente, João J; Cunha, António E; Carrondo, Manuel J T; Oliveira, Rui

2006-01-01

This paper presents a novel method for iterative batch-to-batch dynamic optimization of bioprocesses. The relationship between process performance and control inputs is established by means of hybrid grey-box models combining parametric and nonparametric structures. The bioreactor dynamics are defined by material balance equations, whereas the cell population subsystem is represented by an adjustable mixture of nonparametric and parametric models. Thus optimizations are possible without detailed mechanistic knowledge concerning the biological system. A clustering technique is used to supervise the reliability of the nonparametric subsystem during the optimization. Whenever the nonparametric outputs are unreliable, the objective function is penalized. The technique was evaluated with three simulation case studies. The overall results suggest that the convergence to the optimal process performance may be achieved after a small number of batches. The model unreliability risk constraint along with sampling scheduling are crucial to minimize the experimental effort required to attain a given process performance. In general terms, it may be concluded that the proposed method broadens the application of the hybrid parametric/nonparametric modeling technique to "newer" processes with higher potential for optimization.

Glucoamylase production in batch, chemostat and fed-batch cultivations by an industrial strain of Aspergillus niger

DEFF Research Database (Denmark)

Pedersen, Henrik; Beyer, Michael; Nielsen, Jens

2000-01-01

The Aspergillus niger strain BO-1 was grown in batch, continuous (chemostat) and fed-batch cultivations in order to study the production of the extracellular enzyme glucoamylase under different growth conditions. In the pH range 2.5-6.0, the specific glucoamylase productivity and the specific...

Morphology and antimony segregation of spangles on batch hot-dip galvanized coatings

Science.gov (United States)

Peng, Shu; Lu, Jintang; Che, Chunshan; Kong, Gang; Xu, Qiaoyu

2010-06-01

Spangles produced by batch hot-dip galvanizing process have a rougher surface and a greater surface segregation of alloying element compared with those in continuous hot-dip galvanizing line (CGL), owing to the cooling rate of the former is much smaller than that of the later. Therefore, typical spangles on a batch hot-dipped Zn-0.05Al-0.2Sb alloy coating were investigated. The chemical, morphological characterization and identification of the phases on the spangles were examined by scanning electron microscopy (SEM), backscattered electron imaging (BSE), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS) and X-ray diffraction analysis (XRD). The results showed that the coating surface usually exhibited three kinds of spangles: shiny, feathery and dull spangle, of which extensively antimony surface segregation was detected. The nature of precipitate on the coating surface was identified as β-Sb 3Zn 4, The precipitated β-Sb 3Zn 4 particles distributed randomly on the shiny spangle surface, both β-Sb 3Zn 4 particles and dentritic segregation of antimony dispersed in the dendritic secondary arm spacings of the feathery spangle and on the whole dull spangle surface. The dentritic segregation of antimony and precipitation of Sb 3Zn 4 compound are discussed by a proposed model.

The Spectral Shift Control Reactor as an option for much improved uranium utilisation in single-batch SMRs

Energy Technology Data Exchange (ETDEWEB)

Lindley, B.A., E-mail: bal29@cam.ac.uk; Parks, G.T.

2016-12-01

Highlights: • A PWR with mixed D{sub 2}O/H{sub 2}O moderator/coolant is investigated for SMR applications. • Heavy water concentration varied over the cycle to give ‘spectral shift’ operation. • Much wetter lattice than normal is neutronically favourable. • Taller fuel stack is thus needed to ensure acceptable MDNBR. • 35–43% increase in uranium utilisation for single batch reactor is possible. - Abstract: The Spectral Shift Control Reactor (SSCR) uses a mix of D{sub 2}O and H{sub 2}O to moderate and cool the reactor. Initially, a high proportion of D{sub 2}O is used, such that the reactor is substantially under-moderated, with excess neutrons being primarily captured in {sup 238}U, breeding {sup 239}Pu. Towards the end of the cycle (EOC), the coolant is predominantly H{sub 2}O, thermalising the neutron spectrum and increasing reactivity. Recently, small modular reactors (SMRs) have gained significant interest as a means of providing a power source that requires little maintenance and refuelling. This motivates long cycles and reduced batch operation. For a single-batch reactor, there is typically a 33% penalty to uranium utilisation compared to a 3-batch reactor. Lattice calculations demonstrate the potential of the SSCR to greatly improve uranium utilisation in single-batch reactors over a range of enrichments. A relatively ‘wet’ lattice is employed which further improves uranium utilisation. Cases with 5% and 15% fissile loading are considered, for which it is respectively possible to achieve 47% and 39% increases in natural uranium utilisation using the SSCR relative to a ‘reference’ light water reactor. In the latter case, if 25% thorium is mixed into the fuel, the improvement in uranium utilisation increases to a total of 49%. Hence, in both cases, it is possible to in effect eliminate the penalty of using a single fuel batch. The ‘wet’ lattice introduces substantial thermal-hydraulic challenges due to the significantly higher fuel

CONVERSION OF PINEAPPLE JUICE WASTE INTO LACTIC ACID IN BATCH AND FED – BATCH FERMENTATION SYSTEMS

Directory of Open Access Journals (Sweden)

Abdullah Mochamad Busairi

2012-01-01

Full Text Available Pineapple juice waste contains valuable components, which are mainly sucrose, glucose, and fructose. Recently, lactic acid has been considered to be an important raw material for the production of biodegradable lactide polymer. The fermentation experiments were carried out in a 3 litres fermentor (Biostat B Model under anaerobic condition with stirring speed of 50 rpm, temperature at 40oC, and pH of 6.00. Effect of feed concentration on lactic acid production, bacterial growth, substrate utilisation and productivity was studied. The results obtained from fed- batch culture fermentation showed that the maximum lactic acid productivity was 0.44 g/L.h for feed concentration of 90 g/L at 48 hours. Whereas the lactic acid productivity obtained from fed-batch culture was twice and half fold higher than that of batch culture productivity.  Buangan jus nanas mengandung komponen yang berharga terutama sukrosa, glukosa, dan fruktosa. Asam laktat adalah bahan baku yang terbaru dan penting untuk dibuat sebagai polimer laktat yang dapat terdegradasi oleh lingkungan. Percobaan dilakukan pada fermentor 3 liter (Model Biostat B di bawah kondisi anaerob dengan kecepatan pengadukan 50 rpm, temperatur 40oC, dan pH 6,00. Pengaruh konsentrasi umpan terhadap produksi asam laktat, pertumbuhan mikroba, pengggunaan substrat dan produktivitas telah dipelajari. Hasil yang didapatkan pada fermentasi dengan menggunakan sistem fed-batch menunjukkan bahwa produktivitas asam laktat maksimum adalah 0.44 g/L,jam dengan konsentrasi umpan, 90 g/L pada waktu 48 jam. Bahkan produktivitas asam laktat yang didapat pada kultur fed-batch lebih tinggi 2,5 kali dari pada proses menggunakan sistem batch

Passing in Command Line Arguments and Parallel Cluster/Multicore Batching in R with batch.

Science.gov (United States)

Hoffmann, Thomas J

2011-03-01

It is often useful to rerun a command line R script with some slight change in the parameters used to run it - a new set of parameters for a simulation, a different dataset to process, etc. The R package batch provides a means to pass in multiple command line options, including vectors of values in the usual R format, easily into R. The same script can be setup to run things in parallel via different command line arguments. The R package batch also provides a means to simplify this parallel batching by allowing one to use R and an R-like syntax for arguments to spread a script across a cluster or local multicore/multiprocessor computer, with automated syntax for several popular cluster types. Finally it provides a means to aggregate the results together of multiple processes run on a cluster.

Effect of γ-radiation on crystallization of polycaprolactone

International Nuclear Information System (INIS)

Zhu Guangming; Xu, Qianyong; Qin Ruifeng; Yan Hongxia; Liang Guozheng

2005-01-01

The crystallization behavior of radiation cross-linked poly(ε-caprolactone) (PCL) was studied by DSC at different cooling rates. The crystallization process was analyzed by the Ozawa equation and the Mo-Zhishen method that is developed from combining the Avrami equation and the Ozawa equation. It was concluded that the crystallization of radiation crosslinked PCL is governed by heterogeneous nucleation and single-dimension growth; the crystal fraction and rates of crystallization are related to the radiation dose and degree of cross-linking; the relationship between relative crystallinity and time follows the Ozawa equation: The higher the degree of crosslinking, the less the crystal velocity constant. The activation energy of crystallization for irradiated PCL is between 65 and 54kJ/mol

High performance batch production of LREBa2Cu3Oy using novel thin film Nd-123 seed

International Nuclear Information System (INIS)

Muralidhar, M.; Suzuki, K.; Fukumoto, Y.; Ishihara, A.; Tomita, M.

2011-01-01

A batch production for fabrication of LREBa 2 Cu 3 O y (LRE: Sm, Gd, NEG) 'LRE-123' pellets are developed in air and Ar-1% O 2 using a novel thin film Nd-123 seeds grown on MgO crystals. The SEM and XRD results conformed that the quality and orientation of the seed crystals are excellent. On the other hand, new seeds can withstand temperatures >1100 deg. C, as a result, the cold seeding process was applied even to grow Sm-123 material in Air. The trapped field observed in the best 45 mm single-grain puck of Gd-123 was in the range of 1.35 T and 0.35 T at 77.3 K and 87.3 K, respectively. The average trapped field at 77.3 K in the 24 mm diameter NEG-123 samples batch lies between 0.9 and 1 T. The maximum trapped field of 1.2 T was recorded at the sample surface. Further, the maximum trapped field of 0.23 T at 77 K was recorded in a sample with 16 mm diameter of Sm-123 with 3 mol% BaO 2 addition. As a result we made more then 130 single grain pucks within a couple of months. Taking advantage of the single grain batch processed material, we constructed self-made chilled levitation disk, which was used on the open day of railway technical research Institute. More then 150 children stood on the levitation disk and revel the experience of levitation. The present results prove that a high-performance good-quality class of LREBa 2 Cu 3 O y material can be made by using a novel thin film Nd-123 seeds.

On-line Scheduling Of Multi-Server Batch Operations

NARCIS (Netherlands)

van der Zee, D.J.; van Harten, A.; Schuur, P.C.

1999-01-01

Batching jobs in a manufacturing system is a very common policy in most industries. Main reasons for batching are avoidance of setups and/or facilitation of material handling. Good examples of batch-wise production systems are ovens found in aircraft industry and in semiconductor manufacturing.

[Batch release of immunoglobulin and monoclonal antibody products].

Science.gov (United States)

Gross, S

2014-10-01

The Paul-Ehrlich Institute (PEI) is an independent institution of the Federal Republic of Germany responsible for performing official experimental batch testing of sera. The institute decides about the release of each batch and performs experimental research in the field. The experimental quality control ensures the potency of the product and also the absence of harmful impurities. For release of an immunoglobulin batch the marketing authorization holder has to submit the documentation of the manufacture and the results of quality control measures together with samples of the batch to the PEI. Experimental testing is performed according to the approved specifications regarding the efficacy and safety. Since implementation of the 15th German drug law amendment, the source of antibody is not defined anymore. According to § 32 German drug law, all batches of sera need to be released by an official control laboratory. Sera are medicinal products, which contain antibodies, antibody fragments or fusion proteins with a functional antibody portion. Therefore, all batches of monoclonal antibodies and derivatives must also be released by the PEI and the marketing authorization holder has to submit a batch release application. Under certain circumstances a waiver for certain products can be issued with regard to batch release. The conditions for such a waiver apply to the majority of monoclonal antibodies.

The Effect of Water Mist Cooling of Casting Die on the Solidification, Microstructure and Properties of AlSi20 Alloy

Directory of Open Access Journals (Sweden)

Władysiak R.

2017-03-01

Full Text Available Unmodified AlSi20 alloy were casted at the research station, allowing for sequential multipoint cooling using a dedicated computer- controlled program. This method allows for the formation of the microstructure of hypereutectic AlSi20 alloy and also increases hardness. Primary silicon dendrites were found in the microstructure of cooled samples. Based on these dendrites, the formation of primary silicon particles is explained. Cooling of casting die with a water mist stream causes changes in solidification, which leads to expansion of the boundary layer with columnar crystals and shrinkage of the core zone with equiaxed crystals. It also causes more regular hardness distribution around pre-eutectic Si crystals, which can lead to tensile strength and machinability improvement.

LSF usage for batch at CERN

CERN Multimedia

Schwickerath, Ulrich

2007-01-01

Contributed poster to the CHEP07. Original abstract: LSF 7, the latest version of Platform's batch workload management system, addresses many issues which limited the ability of LSF 6.1 to support large scale batch farms, such as the lxbatch service at CERN. In this paper we will present the status of the evaluation and deployment of LSF 7 at CERN, including issues concerning the integration of LSF 7 with the gLite grid middleware suite and, in particular, the steps taken to endure an efficient reporting of the local batch system status and usage to the Grid Information System

Crystallization of glycine with ultrasound

DEFF Research Database (Denmark)

Louhi-Kultanen, Marjatta; Karjalainen, Milja; Rantanen, Jukka

2006-01-01

Sonocrystallization has proved to be an efficient tool to influence the external appearance and structure of a crystalline product obtained by various crystallization methods. The present work focuses on high intensity sonocrystallization of glycine by varying amplitude of ultrasound with an ultr...... ultrasound power. This study also showed, the higher the ultrasound amplitude the smaller the crystals obtained.......Sonocrystallization has proved to be an efficient tool to influence the external appearance and structure of a crystalline product obtained by various crystallization methods. The present work focuses on high intensity sonocrystallization of glycine by varying amplitude of ultrasound...... with an ultrasound frequency of 20kHz at two temperature ranges 40-50 and 20-30 degrees C in a jacketed 250-ml cooling crystallizer equipped with a stirrer. The polymorph composition of the obtained crystals was analyzed with a temperature variable X-ray powder diffractometer (XRPD). XRPD results showed that...

Single Crystal Piezoelectric Stack Actuator DM with Integrated Low-Power HVA-Based Driver ASIC, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This SBIR Phase I project aims to develop an innovative batch fabrication technique to create single crystal PMN-PT stack actuator deformable mirrors (DM) at low...

Transient Self-assembly of Edible Lipids During Crystallization

Science.gov (United States)

Mazzanti, Gianfranco; Marangoni, Alejandro; Idziak, Stefan

2002-03-01

The effects of cooling rate and shear on the structure and crystallization behavior of two natural triglyceride melts were studied using rheology and light scattering. A transparent Couette Cell with 1 mm gap was used to perform light scattering measurements. A rheometer with concentric cylinders with 1 mm gap was used for the rheological tests. Experiments were carried out at cooling rates of 3 and 0.5 C/min from the 45 C melt down to temperatures between 17.5 C and 30 C. The shear rates imposed were 90 and 1440 s-1. Results show that the effect of shear on the onset of crystallization is especially evident at slow cooling rates. The effect of shear on crystalline phase growth is more pronounced at higher temperatures and slow cooling rates. Quasi-stationary studies were carried out in the rheometer operated in a controlled stress oscillatory mode, and strain amplitudes were less than 2experiments were performed in a petroleum analyzer and in a glass capillary. The onset of light scattering coincides with an unexpected transient increase in the amplitude of the oscillatory response.

A convenient tool for gas derivatization using fine-needle capillary mounting for protein crystals

International Nuclear Information System (INIS)

Mizuno, Nobuhiro; Makino, Masatomo; Kumasaka, Takashi

2013-01-01

A convenient gas-derivatization tool for protein crystals is presented in combination with a fine-needle capillary and a gas-pressure regulator. Gas derivatization of protein crystals is useful not only to analyse gas-binding proteins but also to solve the phase problem of X-ray crystallography by using noble gases. However, the gas pressurization tools for these experiments are often elaborate and need to release the gas before flash-cooling. To simplify this step, a procedure using a fine-needle capillary to mount and flash-cool protein crystals under the pressurization of gases has been developed. After the crystals are picked up with the capillary, the capillary is sealed with an adhesive and then connected directly to a gas regulator. The quality of the diffraction data using this method is comparable with that of data from conventional pressurization procedures. The preparation of xenon-derivatives of hen egg-white lysozyme using this method was a success. In the derivatives, two new xenon binding sites were found and one of their sites vanished by releasing the gas. This observation shows the availability of flash-cooling under gas pressurization. This procedure is simple and useful for preparing gas-derivative crystals

Deposit control in process cooling water systems

International Nuclear Information System (INIS)

Venkataramani, B.

1981-01-01

In order to achieve efficient heat transfer in cooling water systems, it is essential to control the fouling of heat exchanger surfaces. Solubilities of scale forming salts, their growth into crystals, and the nature of the surfaces play important roles in the deposition phenomenon. Condensed phosphates, organic polymers and compounds like phosphates are effective in controlling deposition of scale forming salts. The surface active agents inhibit crystal growth and modify the crystals of the scale forming salts, and thus prevent deposition of dense, uniformly structured crystalline mass on the heat transfer surface. Understanding the mechanism of biofouling is essential to control it by surface active agents. Certain measures taken in the plant, such as back flushing, to control scaling, sometimes may not be effective and can be detrimental to the system itself. (author)

Family based dispatching with batch availability

NARCIS (Netherlands)

van der Zee, D.J.

2013-01-01

Family based dispatching rules seek to lower set-up frequencies by grouping (batching) similar types of jobs for joint processing. Hence shop flow times may be improved, as less time is spent on set-ups. Motivated by an industrial project we study the control of machines with batch availability,

On-line scheduling of multi-server batch operations

NARCIS (Netherlands)

Zee, Durk Jouke van der; Harten, Aart van; Schuur, Peter

The batching of jobs in a manufacturing system is a very common policy in many industries. The main reasons for batching are the avoidance of setups and/or facilitation of material handling. Good examples of batch-wise production systems are the ovens that are found in the aircraft industry and in

Separation of glucose and fructose by freezing crystallization

Energy Technology Data Exchange (ETDEWEB)

Silva, A.T.C.R.; Martinez, K.C.L. [Federal University of Sao Carlos, Chemical Engineering Department, Industrial Crystallization Laboratory - Rod. Washington Luis km 235, P.O. Box 676, CEP:13565-905, Sao Carlos-SP (Brazil); Brito, A.B.N. [Federal University of Espirito Santo, Engineering and Computing Dept. - Rodovia BR 101 Norte, Km. 60, Bairro Litoraneo, CEP 29932-540, Sao Mateus-ES (Brazil); Giulietti, M. [Laboratory of Chemical Process and Particle Technology of Institute for Technological Research, Av. Prof. Almeida Prado 532 -Universitary City, CEP:05508-901, Sao Paulo-SP (Brazil)

2010-10-15

This work comprises the implementation of a methodology for the study of an industrial crystallization process by freezing and cooling to be applied in the separation of sugars with industrial relevance (glucose and fructose). The main interest is the production of fructose. This sugar is obtained by sucrose hydrolysis in acidic solutions, which yields an equimolar mixture of glucose and fructose. The developed separation process is based on the solubility difference between the sugars. Experiments were carried out in a jacketed glass crystallizer where the solution coming from the sucrose acid inversion was submitted to a slow cooling. Since glucose has lower solubility than fructose, it crystallizes in the bulk as the temperature is lowered, thus it can be removed from the solution by filtration or centrifugation. Best fructose-glucose separation was achieved for a total sugar concentration of 50 wt%. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Modeling of tri-chloro-fluoro-methane hydrate formation in a w/o emulsion submitted to steady cooling

Energy Technology Data Exchange (ETDEWEB)

Avendano-Gomez, Juan Ramon; Limas-Ballesteros, Roberto [Laboratorio de Investigacion en Ingenieria Quimica Ambiental, SEPI-ESIQIE, Instituto Politecnico Nacional, Unidad Profesional Adolfo Lopez Mateos, Zacatenco, Edificio 8, 3. piso 07738, Mexico DF (Mexico); Garcia-Sanchez, Fernando [Laboratorio de Termodinamica, Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, 07730 Mexico DF (Mexico)

2006-05-15

The aim of this work is to study the modeling of the thermal evolution inside an hydrate forming system which is submitted to an imposed steady cooling. The study system is a w/o emulsion where the formulation considers the CCl{sub 3}F as the hydrate forming molecule dissolved in the oil phase. The hydrate formation occurs in the aqueous phase of the emulsion, i.e. in the dispersed phase. The model equation is based on the resolution of the continuity equation in terms of a heat balance for the dispersed phase. The crystallization of the CCl{sub 3}F hydrate occurs at supercooling conditions (T{sub c}crystallization interferes with the imposed condition of steady decrease of temperature around the system. Thus, the inclusion of the heat source term has to be considered in order to take into account the influence of crystallization. The rate of heat released during the crystallization is governed by the probability of nucleation J(T). Previous experimental measurements allowed to derive the corresponding function J(T) of the w/o emulsion. The results provided by the model equation subjected to boundary conditions allow to depict the evolution of temperature in the dispersed phase. The most singular point in the temperature-time curve is the onset time of hydrate crystallization. Three time intervals characterize the evolution of temperature during the steady cooling of the w/o emulsion: (1) steady cooling, (2) hydrate formation with a release of heat, (3) a last interval of steady cooling. (author)

Facile fabrication of single-crystal-diamond nanostructures with ultrahigh aspect ratio.

OpenAIRE

Tao Ye; Degen Christian

2013-01-01

A robust and facile approach for making single crystal diamond MEMS and NEMS devices is presented. The approach relies entirely on commercial diamond material and standard cleanroom processes. As an example batch fabrication of cantilever beams of thickness down to 45 nm and aspect ratios exceeding 2000:1 is demonstrated.

Batching System for Superior Service

Science.gov (United States)

2001-01-01

Veridian's Portable Batch System (PBS) was the recipient of the 1997 NASA Space Act Award for outstanding software. A batch system is a set of processes for managing queues and jobs. Without a batch system, it is difficult to manage the workload of a computer system. By bundling the enterprise's computing resources, the PBS technology offers users a single coherent interface, resulting in efficient management of the batch services. Users choose which information to package into "containers" for system-wide use. PBS also provides detailed system usage data, a procedure not easily executed without this software. PBS operates on networked, multi-platform UNIX environments. Veridian's new version, PBS Pro,TM has additional features and enhancements, including support for additional operating systems. Veridian distributes the original version of PBS as Open Source software via the PBS website. Customers can register and download the software at no cost. PBS Pro is also available via the web and offers additional features such as increased stability, reliability, and fault tolerance.A company using PBS can expect a significant increase in the effective management of its computing resources. Tangible benefits include increased utilization of costly resources and enhanced understanding of computational requirements and user needs.

Formation of co-crystals: Kinetic and thermodynamic aspects

Science.gov (United States)

Gagnière, E.; Mangin, D.; Puel, F.; Rivoire, A.; Monnier, O.; Garcia, E.; Klein, J. P.

2009-04-01

Co-crystallisation is a recent method of great interest for the pharmaceutical industry, since pharmaceutical co-crystals represent useful materials for drug products. In this study, an active pharmaceutical ingredient (carbamazepine (CBZ)) co-crystallized with a vitamin (nicotinamide (NCT)) was chosen as a model substance. This work was focused on the construction of a phase diagram for the system CBZ/NCT, split in six domains for kinetic reasons (the different solid phases which might appear during the crystallisation) and in four domains according to thermodynamic aspects (the stable final phase obtained). Although co-crystals are not ionic compounds, the supersaturation of co-crystals can be evaluated by considering the solubility product. Batch crystallisation operations were carried out in a stirred vessel equipped with an in situ video probe. This latter device was a powerful analysis tool to monitor the CBZ/NCT co-crystals and single CBZ crystals since these two crystalline phases grown in ethanol exhibited needle and platelet habits. As concerns kinetics, the different solid phases which might appear during the experiments were observed and competed against each others. In accordance with thermodynamics, the stable solid form was obtained at the end of the operation. Finally some preliminary results indicate that the nucleation of co-crystals may be favoured by the presence of CBZ crystals. Epitaxial relationships between CBZ/NCT co-crystals and CBZ crystals were suspected.

Performance limits of direct cryogenically cooled silicon monochromators - experimental results at the APS

International Nuclear Information System (INIS)

Lee, W.-K.; Fernandez, P.; Mills, D.M.

2000-01-01

The successful use of cryogenically cooled silicon monochromators at third-generation synchrotron facilities is well documented. At the Advanced Photon Source (APS) it has been shown that, at 100 mA operation with the standard APS undulator A, the cryogenically cooled silicon monochromator performs very well with minimal (<2 arcsec) or no observable thermal distortions. However, to date there has not been any systematic experimental study on the performance limits of this approach. This paper presents experimental results on the performance limits of these directly cooled crystals. The results show that if the beam is limited to the size of the radiation central cone then, at the APS, the crystal will still perform well at twice the present 100 mA single 2.4 m-long 3.3 cm-period undulator heat load. However, the performance would degrade rapidly if a much larger incident white-beam size is utilized

Effect of solvent on crystallization behavior of xylitol

Science.gov (United States)

Hao, Hongxun; Hou, Baohong; Wang, Jing-Kang; Lin, Guangyu

2006-04-01

Effect of organic solvents content on crystallization behavior of xylitol was studied. Solubility and crystallization kinetics of xylitol in methanol-water system were experimentally determined. It was found that the solubility of xylitol at various methanol content all increases with increase of temperature. But it decreases when increasing methanol content at constant temperature. Based on the theory of population balance, the nucleation and growth rates of xylitol in methanol-water mixed solvents were calculated by moments method. From a series of experimental population density data of xylitol gotten from a batch-operated crystallizer, parameters of crystal nucleation and growth rate equations at different methanol content were got by the method of nonlinear least-squares. By analyzing, it was found that the content of methanol had an apparent effect on nucleation and growth rate of xylitol. At constant temperature, the nucleation and growth rate of xylitol all decrease with increase of methanol content.

More accurate determination of the quantity of ice crystallized at low cooling rates in the glycerol and 1,2-propanediol aqueous solutions: comparison with equilibrium.

Science.gov (United States)

Boutron, P

1984-04-01

It is generally assumed that when cells are cooled at rates close to those corresponding to the maximum of survival, once supercooling has ceased, above the eutectic melting temperature the extracellular ice is in equilibrium with the residual solution. This did not seem evident to us due to the difficulty of ice crystallization in cryoprotective solutions. The maximum quantities of ice crystallized in glycerol and 1,2-propanediol solutions have been calculated from the area of the solidification and fusion peaks obtained with a Perkin-Elmer DSC-2 differential scanning calorimeter. The accuracy has been improved by several corrections: better defined baseline, thermal variation of the heat of fusion of the ice, heat of solution of the water from its melting with the residual solution. More ice crystallizes in the glycerol than in the 1,2-propanediol solutions, of which the amorphous residue contains about 40 to 55% 1,2-propanediol. The equilibrium values are unknown in the presence of 1,2-propanediol. With glycerol, in our experiments, the maximum is first lower than the equilibrium but approaches it as the concentration increases. It is not completely determined by the colligative properties of the solutes.

Batch-To-Batch Rational Feedforward Control : From Iterative Learning to Identification Approaches, with Application to a Wafer Stage

NARCIS (Netherlands)

Blanken, L.; Boeren, F.A.J.; Bruijnen, D.J.H.; Oomen, T.A.E.

2017-01-01

Feedforward control enables high performance for industrial motion systems that perform nonrepeating motion tasks. Recently, learning techniques have been proposed that improve both performance and flexibility to nonrepeating tasks in a batch-To-batch fashion by using a rational parameterization in

Improved reproducibility of unit-cell parameters in macromolecular cryocrystallography by limiting dehydration during crystal mounting.

Science.gov (United States)

Farley, Christopher; Burks, Geoffry; Siegert, Thomas; Juers, Douglas H

2014-08-01

In macromolecular cryocrystallography unit-cell parameters can have low reproducibility, limiting the effectiveness of combining data sets from multiple crystals and inhibiting the development of defined repeatable cooling protocols. Here, potential sources of unit-cell variation are investigated and crystal dehydration during loop-mounting is found to be an important factor. The amount of water lost by the unit cell depends on the crystal size, the loop size, the ambient relative humidity and the transfer distance to the cooling medium. To limit water loss during crystal mounting, a threefold strategy has been implemented. Firstly, crystal manipulations are performed in a humid environment similar to the humidity of the crystal-growth or soaking solution. Secondly, the looped crystal is transferred to a vial containing a small amount of the crystal soaking solution. Upon loop transfer, the vial is sealed, which allows transport of the crystal at its equilibrated humidity. Thirdly, the crystal loop is directly mounted from the vial into the cold gas stream. This strategy minimizes the exposure of the crystal to relatively low humidity ambient air, improves the reproducibility of low-temperature unit-cell parameters and offers some new approaches to crystal handling and cryoprotection.

Lipid production in batch and fed-batch cultures of Rhodosporidium toruloides from 5 and 6 carbon carbohydrates

Directory of Open Access Journals (Sweden)

Wiebe Marilyn G

2012-05-01

Full Text Available Abstract Background Microbial lipids are a potential source of bio- or renewable diesel and the red yeast Rhodosporidium toruloides is interesting not only because it can accumulate over 50% of its dry biomass as lipid, but also because it utilises both five and six carbon carbohydrates, which are present in plant biomass hydrolysates. Methods R. toruloides was grown in batch and fed-batch cultures in 0.5 L bioreactors at pH 4 in chemically defined, nitrogen restricted (C/N 40 to 100 media containing glucose, xylose, arabinose, or all three carbohydrates as carbon source. Lipid was extracted from the biomass using chloroform-methanol, measured gravimetrically and analysed by GC. Results Lipid production was most efficient with glucose (up to 25 g lipid L−1, 48 to 75% lipid in the biomass, at up to 0.21 g lipid L−1 h−1 as the sole carbon source, but high lipid concentrations were also produced from xylose (36 to 45% lipid in biomass. Lipid production was low (15–19% lipid in biomass with arabinose as sole carbon source and was lower than expected (30% lipid in biomass when glucose, xylose and arabinose were provided simultaneously. The presence of arabinose and/or xylose in the medium increased the proportion of palmitic and linoleic acid and reduced the proportion of oleic acid in the fatty acids, compared to glucose-grown cells. High cell densities were obtained in both batch (37 g L−1, with 49% lipid in the biomass and fed-batch (35 to 47 g L−1, with 50 to 75% lipid in the biomass cultures. The highest proportion of lipid in the biomass was observed in cultures given nitrogen during the batch phase but none with the feed. However, carbohydrate consumption was incomplete when the feed did not contain nitrogen and the highest total lipid and best substrate consumption were observed in cultures which received a constant low nitrogen supply. Conclusions Lipid production in R. toruloides was lower from arabinose and mixed

On-line monitoring of the crystallization process: relationship between crystal size and electrical impedance spectra

International Nuclear Information System (INIS)

Zhao, Yanlin; Yao, Jun; Wang, Mi

2016-01-01

On-line monitoring of crystal size in the crystallization process is crucial to many pharmaceutical and fine-chemical industrial applications. In this paper, a novel method is proposed for the on-line monitoring of the cooling crystallization process of L-glutamic acid (LGA) using electrical impedance spectroscopy (EIS). The EIS method can be used to monitor the growth of crystal particles relying on the presence of an electrical double layer on the charged particle surface and the polarization of double layer under the excitation of alternating electrical field. The electrical impedance spectra and crystal size were measured on-line simultaneously by an impedance analyzer and focused beam reflectance measurement (FBRM), respectively. The impedance spectra were analyzed using the equivalent circuit model and the equivalent circuit elements in the model can be obtained by fitting the experimental data. Two equivalent circuit elements, including capacitance ( C 2 ) and resistance ( R 2 ) from the dielectric polarization of the LGA solution and crystal particle/solution interface, are in relation with the crystal size. The mathematical relationship between the crystal size and the equivalent circuit elements can be obtained by a non-linear fitting method. The function can be used to predict the change of crystal size during the crystallization process. (paper)

Evaluation of vitrification factors from DWPF's macro-batch 1

International Nuclear Information System (INIS)

Edwards, T.B.

2000-01-01

The Defense Waste Processing Facility (DWPF) is evaluating new sampling and analytical methods that may be used to support future Slurry Mix Evaporator (SME) batch acceptability decisions. This report uses data acquired during DWPF's processing of macro-batch 1 to determine a set of vitrification factors covering several SME and Melter Feed Tank (MFT) batches. Such values are needed for converting the cation measurements derived from the new methods to a ''glass'' basis. The available data from macro-batch 1 were used to examine the stability of these vitrification factors, to estimate their uncertainty over the course of a macro-batch, and to provide a recommendation on the use of a single factor for an entire macro-batch. The report is in response to Technical Task Request HLW/DWPF/TTR-980015

Growth of emerald single crystals

International Nuclear Information System (INIS)

Bukin, G.V.; Godovikov, A.A.; Klyakin, V.A.; Sobolev, V.S.

1986-01-01

In addition to its use for jewelry, emerald can also be used in low-noise microwave amplifiers. The authors discuss flux crystallization of emerald and note that when emerald is grown by this method, it is desirable to use solvents which dissolve emerald with minimum deviations from congruence but at the same time with sufficient high efficiency. Emerald synthesis and crystal growth from slowly cooled solutions is discussed as another possibility. The techniques are examined. Vapor synthesis and growht of beryl crystals re reviewed and the authors experimentally study the seeded CVD crystallization of beryl from BeO, Al 2 O 3 and SiO 2 oxides, by using complex compounds as carrier agents. The color of crystals of emerald and other varieties of beryl is detemined by slelective light absorption in teh visible part of the spectrum and depends on the density and structural positions of chromphore ions: chromium, iron, vanadium, nickel, manganese and cobalt

Sojourn time distributions in a Markovian G-queue with batch arrival and batch removal

Directory of Open Access Journals (Sweden)

Yang Woo Shin

1999-01-01

Full Text Available We consider a single server Markovian queue with two types of customers; positive and negative, where positive customers arrive in batches and arrivals of negative customers remove positive customers in batches. Only positive customers form a queue and negative customers just reduce the system congestion by removing positive ones upon their arrivals. We derive the LSTs of sojourn time distributions for a single server Markovian queue with positive customers and negative customers by using the first passage time arguments for Markov chains.

Ilchulbong tuff cone, Jeju Island, Korea, revisited: A compound monogenetic volcano involving multiple magma batches, shifting vents, and discrete eruptive phases

Science.gov (United States)

Sohn, Y.; Brenna, M.; Smith, I. E.; Nemeth, K.; White, J. D.; Murtagh, R.; Jeon, Y.; Kwon, C.; Cronin, S. J.

2010-12-01

Ilchulbong (Sunrise Peak) tuff cone is a UNESCO World Heritage site that owes its scientific importance to the outstanding coastal exposures that surround it. It is also one of the classic sites that provided the sedimentary evidence for the primary pyroclastic processes that occur during phreatomagmatic basaltic eruptions. It has been long considered, based on the cone morphology, that this classic cone was produced via eruption from a single vent site. Reanalysis of the detailed sedimentary sequence has now revealed that two subtle paraconformities occur in this deposition sequence, one representing a significant time break of perhaps days to weeks or months, during which erosion and compaction of the lower cone occurred, the conduit cooled and solidified and a subsequent resumption of eruption took place in a new vent location. Detailed geochemical study of the juvenile clasts through this cone reveals that three separate alkali basaltic magma batches were erupted, the first and third erupted may be genetically related, with the latter showing evidence for longer periods of shallow-level fractionation. The second magma batch erupted was generated in a different mantle source area. Reconstructing the eruption sequence, the lower Ilchulbong cone was formed by eruption of magma 1. Cessation of eruption was accompanied by erosion to generate a volcano-wide unconformity, associated with reworked deposits in the lower cone flanks. The eruption resumed with magma 2 that, due to the cooled earlier conduit, was forced to erupt in a new site to the west of the initial vent. This formed the middle cone sequence over the initially formed structure. The third magma batch erupted with little or no interval after magma 2 from the same vent location, associated with cone instability and slumping, and making up the deposits of the upper cone. These results demonstrate how critical the examination for sedimentary evidence for time breaks in such eruption sequences is for

Study of Te Inclusions in CdMnTe Crystals for Nuclear Detector Applications

International Nuclear Information System (INIS)

Babalola, O.S.; Bolotnikov, A.; Groza, M.; Hossain, A.; Egarievwe, S.; James, R.; Burger, A.

2009-01-01

The concentration, size and spatial distribution of Te inclusions in the bulk of CdMnTe crystals mined from two batches of ingots were studied. An isolated planar layer decorated with Te inclusions was identified in CdMnTe crystals from the second ingot. The internal electric field of a CMT crystal was probed by infrared (IR) imaging employing Pockels electro-optic effect. The effect of an isolated plane of Te inclusions on the internal electric-field distribution within the CdMnTe crystal was studied. Space charge accumulation around the plane of Te inclusions was observed, which was found to be higher when the detector was reverse-biased. The effects of the plane of Te inclusions on the electric-field distribution within the CdMnTe crystal, and the quality of CdMnTe crystals for nuclear detector applications are discussed.

Study of alloy crystallization in systems undergoing peritectic transformations

International Nuclear Information System (INIS)

Psarev, V.I.; Kirij, V.G.; Kuznetsov, A.V.; Psareva, I.V.; Ivanov, A.L.

1982-01-01

Studies into Ge-Te, In-Te, Al-Mn, Sb-Zn, Sn-Au systems are carried out at melt cooling rates from 50 deg/h to 10 5 deg/h to establish regularities in stable and metastable crystallization of alloys undergoing peritectic transformations. Methods of metallographic, X-ray phase and X-ray diffraction analyses are used. Differentiation in types of peritectic transformations is made through their mechanisms under equilibrium and non-equilibrium crystallization conditions for various alloy systems. It is found out that ability to supercooling even at low or moderate cooling rates for Te-Ge and Te-In system melts can be one of the main indication of the possibility of amorphous alloy formation [ru

Device for isolation of seed crystals during processing of solution

Science.gov (United States)

Montgomery, K.E.; Zaitseva, N.P.; Deyoreo, J.J.; Vital, R.L.

1999-05-18

A device is described for isolation of seed crystals during processing of solutions. The device enables a seed crystal to be introduced into the solution without exposing the solution to contaminants or to sources of drying and cooling. The device constitutes a seed protector which allows the seed to be present in the growth solution during filtration and overheating operations while at the same time preventing the seed from being dissolved by the under saturated solution. When the solution processing has been completed and the solution cooled to near the saturation point, the seed protector is opened, exposing the seed to the solution and allowing growth to begin. 3 figs.

Queue Length and Server Content Distribution in an Infinite-Buffer Batch-Service Queue with Batch-Size-Dependent Service

Directory of Open Access Journals (Sweden)

U. C. Gupta

2015-01-01

Full Text Available We analyze an infinite-buffer batch-size-dependent batch-service queue with Poisson arrival and arbitrarily distributed service time. Using supplementary variable technique, we derive a bivariate probability generating function from which the joint distribution of queue and server content at departure epoch of a batch is extracted and presented in terms of roots of the characteristic equation. We also obtain the joint distribution of queue and server content at arbitrary epoch. Finally, the utility of analytical results is demonstrated by the inclusion of some numerical examples which also includes the investigation of multiple zeros.

Examining the role of canister cooling conditions on the formation of nepheline from nuclear waste glasses

Energy Technology Data Exchange (ETDEWEB)

Christian, J. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-09-01

Nepheline (NaAlSiO₄) crystals can form during slow cooling of high-level waste (HLW) glass after it has been poured into a waste canister. Formation of these crystals can adversely affect the chemical durability of the glass. The tendency for nepheline crystallization to form in a HLW glass increases with increasing concentrations of Al₂O₃ and Na₂O.

Polynomial Batch Codes for Efficient IT-PIR

Directory of Open Access Journals (Sweden)

Henry Ryan

2016-10-01

Full Text Available Private information retrieval (PIR is a way for clients to query a remote database without the database holder learning the clients’ query terms or the responses they generate. Compelling applications for PIR are abound in the cryptographic and privacy research literature, yet existing PIR techniques are notoriously inefficient. Consequently, no such PIRbased application to date has seen real-world at-scale deployment. This paper proposes new “batch coding” techniques to help address PIR’s efficiency problem. The new techniques exploit the connection between ramp secret sharing schemes and efficient information-theoretically secure PIR (IT-PIR protocols. This connection was previously observed by Henry, Huang, and Goldberg (NDSS 2013, who used ramp schemes to construct efficient “batch queries” with which clients can fetch several database records for the same cost as fetching a single record using a standard, non-batch query. The new techniques in this paper generalize and extend those of Henry et al. to construct “batch codes” with which clients can fetch several records for only a fraction the cost of fetching a single record using a standard non-batch query over an unencoded database. The batch codes are highly tuneable, providing a means to trade off (i lower server-side computation cost, (ii lower server-side storage cost, and/or (iii lower uni- or bi-directional communication cost, in exchange for a comparatively modest decrease in resilience to Byzantine database servers.

Citric acid production from hydrolysate of pretreated straw cellulose by Yarrowia lipolytica SWJ-1b using batch and fed-batch cultivation.

Science.gov (United States)

Liu, Xiaoyan; Lv, Jinshun; Zhang, Tong; Deng, Yuanfang

2015-01-01

In this study, crude cellulase produced by Trichoderma reesei Rut-30 was used to hydrolyze pretreated straw. After the compositions of the hydrolysate of pretreated straw were optimized, the study showed that natural components of pretreated straw without addition of any other components such as (NH4)2SO4, KH2PO4, or Mg(2+) were suitable for citric acid production by Yarrowia lipolytica SWJ-1b, and the optimal ventilatory capacity was 10.0 L/min/L medium. Batch and fed-batch production of citric acid from the hydrolysate of pretreated straw by Yarrowia lipolytica SWJ-1b has been investigated. In the batch cultivation, 25.4 g/L and 26.7 g/L citric acid were yields from glucose and hydrolysate of straw cellulose, respectively, while the cultivation time was 120 hr. In the three-cycle fed-batch cultivation, citric acid (CA) production was increased to 42.4 g/L and the cultivation time was extended to 240 hr. However, iso-citric acid (ICA) yield in fed-batch cultivation (4.0 g/L) was similar to that during the batch cultivation (3.9 g/L), and only 1.6 g/L of reducing sugar was left in the medium at the end of fed-batch cultivation, suggesting that most of the added carbon was used in the cultivation.

Morphology and antimony segregation of spangles on batch hot-dip galvanized coatings

Energy Technology Data Exchange (ETDEWEB)

Peng Shu, E-mail: shu.peng@mail.scut.edu.cn [School of Materials Science and Engineering, South China University of Technology, No. 371 Wushan Road, Tianhe District, Guangzhou 510640 (China); Lu Jintang; Che Chunshan; Kong Gang; Xu Qiaoyu [School of Materials Science and Engineering, South China University of Technology, No. 371 Wushan Road, Tianhe District, Guangzhou 510640 (China)

2010-06-01

Spangles produced by batch hot-dip galvanizing process have a rougher surface and a greater surface segregation of alloying element compared with those in continuous hot-dip galvanizing line (CGL), owing to the cooling rate of the former is much smaller than that of the later. Therefore, typical spangles on a batch hot-dipped Zn-0.05Al-0.2Sb alloy coating were investigated. The chemical, morphological characterization and identification of the phases on the spangles were examined by scanning electron microscopy (SEM), backscattered electron imaging (BSE), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS) and X-ray diffraction analysis (XRD). The results showed that the coating surface usually exhibited three kinds of spangles: shiny, feathery and dull spangle, of which extensively antimony surface segregation was detected. The nature of precipitate on the coating surface was identified as {beta}-Sb{sub 3}Zn{sub 4}, The precipitated {beta}-Sb{sub 3}Zn{sub 4} particles distributed randomly on the shiny spangle surface, both {beta}-Sb{sub 3}Zn{sub 4} particles and dentritic segregation of antimony dispersed in the dendritic secondary arm spacings of the feathery spangle and on the whole dull spangle surface. The dentritic segregation of antimony and precipitation of Sb{sub 3}Zn{sub 4} compound are discussed by a proposed model.

Batch and multi-step fed-batch enzymatic saccharification of Formiline-pretreated sugarcane bagasse at high solid loadings for high sugar and ethanol titers.

Science.gov (United States)

Zhao, Xuebing; Dong, Lei; Chen, Liang; Liu, Dehua

2013-05-01

Formiline pretreatment pertains to a biomass fractionation process. In the present work, Formiline-pretreated sugarcane bagasse was hydrolyzed with cellulases by batch and multi-step fed-batch processes at 20% solid loading. For wet pulp, after 144 h incubation with cellulase loading of 10 FPU/g dry solid, fed-batch process obtained ~150 g/L glucose and ~80% glucan conversion, while batch process obtained ~130 g/L glucose with corresponding ~70% glucan conversion. Solid loading could be further increased to 30% for the acetone-dried pulp. By fed-batch hydrolysis of the dried pulp in pH 4.8 buffer solution, glucose concentration could be 247.3±1.6 g/L with corresponding 86.1±0.6% glucan conversion. The enzymatic hydrolyzates could be well converted to ethanol by a subsequent fermentation using Saccharomices cerevisiae with ethanol titer of 60-70 g/L. Batch and fed-batch SSF indicated that Formiline-pretreated substrate showed excellent fermentability. The final ethanol concentration was 80 g/L with corresponding 82.7% of theoretical yield. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sequential crystallization and morphology of triple crystalline biodegradable PEO-b-PCL-b-PLLA triblock terpolymers

KAUST Repository

Palacios, Jordana

2016-01-05

The sequential crystallization of poly(ethylene oxide)-b-poly(e-caprolactone)-b-poly(L-lactide) (PEO-b-PCL-b-PLLA) triblock terpolymers, in which the three blocks are able to crystallize separately and sequentially from the melt, is presented. Two terpolymers with identical PEO and PCL block lengths and two different PLLA block lengths were prepared, thus the effect of increasing PLLA content on the crystallization behavior and morphology was evaluated. Wide angle X-Ray scattering (WAXS) experiments performed on cooling from the melt confirmed the triple crystalline nature of these terpolymers and revealed that they crystallize in sequence: the PLLA block crystallizes first, then the PCL block, and finally the PEO block. Differential scanning calorimetry (DSC) analysis further demonstrated that the three blocks can crystallize from the melt when a low cooling rate is employed. The crystallization process takes place from a homogenous melt as indicated by small angle X-Ray scattering (SAXS) experiments. The crystallization and melting enthalpies and temperatures of both PEO and PCL blocks decrease as PLLA content in the terpolymer increases. Polarized light optical microscopy (PLOM) demonstrated that the PLLA block templates the morphology of the terpolymer, as it forms spherulites upon cooling from the melt. The subsequent crystallization of PCL and PEO blocks occurs inside the interlamellar regions of the previously formed PLLA block spherulites. In this way, unique triple crystalline mixed spherulitic superstructures have been observed for the first time. As the PLLA content in the terpolymer is reduced the superstructural morphology changes from spherulites to a more axialitic-like structure.

On the texture and crystal structure of the B19' martensite in single-crystal titanium nickelide

International Nuclear Information System (INIS)

Gundyrev, V.M.; Zel'dovich, V.I.

2003-01-01

The texture of the B19' martensite formed by cooling the Ti-51 at. % Ni alloy in the B2-phase monocrystal is studied. The positions of the (002), (111-bar), (020) and (111) planes of B19' martensite proceeding from the plane (110) of B2-phase relative to this plane are determined for this purpose. It is established that the obtained results may be described on the basis of the accepted monoclinic structure of the B19' martensite and earlier determined orientation ratios. However small deviation from the parallelism of the (020) B19' and (110)B2 planes is observed. Not less that 12 crystallographically equivalent orientations of the martensite crystals are realized by transforming the B2 phase monocrystal into the B19' martensite in the process of cooling in the irradiated volume of 1.5 x 0.01 mm. Realization of various martensite orientations is practically equally probable. Large self-accommodation crystal groups having limited number of orientations do not appear. It is shown that the martensite phases R and B19' are formed by the martensite transformations in the process of cooling. The B19' martensite has the set of the monoclinic angles from 90 p to 96.8 deg [ru

Batch Computed Tomography Analysis of Projectiles

Science.gov (United States)

2016-05-01

ARL-TR-7681 ● MAY 2016 US Army Research Laboratory Batch Computed Tomography Analysis of Projectiles by Michael C Golt, Chris M...Laboratory Batch Computed Tomography Analysis of Projectiles by Michael C Golt and Matthew S Bratcher Weapons and Materials Research...values to account for projectile variability in the ballistic evaluation of armor. 15. SUBJECT TERMS computed tomography , CT, BS41, projectiles

Volume reduction by crystallization of low-level radioactive wastes

International Nuclear Information System (INIS)

Grant, D.C.; Murray, A.P.

1982-01-01

Low-level radioactive wastes containing boric acid, borax, or sodium sulfate, with radioactive contaminants, are generated during the operation of nuclear power plants. These wastes require disposal, and as such, it is economically and environmentally desirable to reduce their volume. Crystallization was examined in the laboratory as a means of accomplishing this. The crystallizer was operated in both of two modes: evaporative cooling and total evaporation. A 12 wt% boric acid waste feed was concentrated to a 40 to 45 wt% slurry in both modes of operation. Using pure boric acid, a slurry containing over 60 wt% was obtained. An 18.5 wt% borax waste feed was concentrated to 50 wt% in the total evaporative mode and 70 wt% in the evaporatively cooled mode. A 22 wt% sodium sulfate feed was concentrated to a 78 wt% slurry in the total evaporative mode. For all of the feeds, this represents a 4- to 5-fold volume reduction by the crystallizer

Degradation of Polypropylene Membranes Applied in Membrane Distillation Crystallizer

Directory of Open Access Journals (Sweden)

Marek Gryta

2016-03-01

Full Text Available The studies on the resistance to degradation of capillary polypropylene membranes assembled in a membrane crystallizer were performed. The supersaturation state of salt was achieved by evaporation of water from the NaCl saturated solutions using membrane distillation process. A high feed temperature (363 K was used in order to enhance the degradation effects and to shorten the test times. Salt crystallization was carried out by the application of batch or fluidized bed crystallizer. A significant membrane scaling was observed regardless of the method of realized crystallization. The SEM-EDS, DSC, and FTIR methods were used for investigations of polypropylene degradation. The salt crystallization onto the membrane surface accelerated polypropylene degradation. Due to a polymer degradation, the presence of carbonyl groups on the membranes’ surface was identified. Besides the changes in the chemical structure a significant mechanical damage of the membranes, mainly caused by the internal scaling, was also found. As a result, the membranes were severely damaged after 150 h of process operation. A high level of salt rejection was maintained despite damage to the external membrane surface.

4 K to 20 K rotational-cooling magnetic refrigerator capable of 1-mW to >1-W operation

International Nuclear Information System (INIS)

Barclay, J.A.

1980-02-01

The low-temperature, magnetic entropy of certain single-crystal paramagnetic materials, such as DyPO 4 , changes dramatically as the crystal rotates in a magnetic field. A new magnetic refrigerator design based on the anisotropic nature of such materials is presented. The key advantages of the rotational-cooling concept are (1) a single, rotary motion is required, (2) magnetic field shaping is not a problem because the entire working material is in a constant field, and (3) the refrigerator can be smaller than comparable magnetic refrigerators because the working material is entirely inside the magnet at all times. The main disadvantage of the rotational-cooling concept is that small-dimension single crystals are required

Test results of a diamond double-crystal monochromator at the advanced photon source

International Nuclear Information System (INIS)

Fernandez, P.B.; Graber, T.; Krasnicki, S.; Lee, W.; Mills, D.M.; Rogers, C.S.; Assoufid, L.

1997-01-01

We have tested the first diamond double-crystal monochromator at the Advanced Photon Source (APS). The monochromator consisted of two synthetic type 1b (111) diamond plates in symmetric Bragg geometry. We tested two pairs of single-crystal plates: the first pair was 6 mm by 5 mm by 0.25 mm and 6 mm by 5 mm by 0.37 mm; the second set was 7 mm by 5.5 mm by 0.44 mm. The monochromator first crystal was indirectly cooled by edge contact with a water-cooled copper holder. We studied the performance of the monochromator under the high-power x-ray beam delivered by the APS undulator A. We found no indication of thermal distortions or strains even at the highest incident power (280 watts) and power density (123W/mm 2 at normal incidence). The calculated maximum power and power density absorbed by the first crystal were 37 watts and 4.3W/mm 2 , respectively. We also compared the maximum intensity delivered by the diamond monochromator and by a silicon (111) cryogenically cooled monochromator. For energies in the range of 6 to 10 keV, the flux through the diamond monochromator was about a factor of two less than through the silicon monochromator, in good agreement with calculations. We conclude that water-cooled diamond monochromators can handle the high-power beams from the undulator beamlines at the APS. As single-crystal diamond plates of larger size and better quality become available, the use of diamond monochromators will become a very attractive option. copyright 1997 American Institute of Physics

Design of an integrated fermentation-crystallization process applied to the production of DOIP

NARCIS (Netherlands)

Blokker, S.; Dabkowski, M.; Groendijk, W.; Renckens, D.; De Rond, J.

2004-01-01

The design problem of CPD3312 was the comparison of the conventional batch (Base case) and the new integrated fermentation-crystallization process (In Situ Product Removal or ISPR case) in particular for the production of 2 tonnes 6R-dihydrooxoisophorone (DOIP) from 4-oxo-isophorone (OIP) per year.

Test of a high-heat-load double-crystal diamond monochromator at the advanced photon source

International Nuclear Information System (INIS)

Fernandez, P.B.; Graber, T.; Lee, W.-K.; Mills, D.M.; Rogers, C.S.; Assoufid, L.

1997-01-01

We have tested the first diamond double-crystal monochromator at the advanced photon source (APS). The monochromator consisted of two synthetic type 1b (111) diamond plates in symmetric Bragg geometry. The single-crystal plates were 6 mm x 5 mm x 0.25 mm and 6 mm x 5 mm x 0.37 mm and showed a combination of mosaic spread/strain of the order of 2-4 arcsec over a central 1.4 mm-wide strip. The monochromator first crystal was indirectly cooled by edge contact with a water-cooled copper holder. We studied the performance of the monochromator under the high-power X-ray beam delivered by the APS undulator A. By changing the undulator gap, we varied the power incident on the first crystal and found no indication of thermal distortions or strains even at the highest incident power (200 W) and power density (108 W/mm 2 in normal incidence). The calculated maximum power and power density absorbed by the first crystal were 14.5 W and 2.4 W/mm 2 , respectively. We also compared the maximum intensity delivered by this monochromator and by a silicon (111) cryogenically cooled monochromator. For energies in the range 6-10 keV, the flux through the diamond monochromator was about a factor of two less than through the silicon monochromator, in good agreement with calculations. We conclude that water-cooled diamond monochromators can handle the high-power beams from the undulator beamlines at the APS. As single-crystal diamond plates of larger size and better quality become available, the use of diamond monochromators will become a very attractive option. (orig.)

A canned food scheduling problem with batch due date

Science.gov (United States)

Chung, Tsui-Ping; Liao, Ching-Jong; Smith, Milton

2014-09-01

This article considers a canned food scheduling problem where jobs are grouped into several batches. Jobs can be sent to the next operation only when all the jobs in the same batch have finished their processing, i.e. jobs in a batch, have a common due date. This batch due date problem is quite common in canned food factories, but there is no efficient heuristic to solve the problem. The problem can be formulated as an identical parallel machine problem with batch due date to minimize the total tardiness. Since the problem is NP hard, two heuristics are proposed to find the near-optimal solution. Computational results comparing the effectiveness and efficiency of the two proposed heuristics with an existing heuristic are reported and discussed.

Prunus dulcis, Batch

African Journals Online (AJOL)

STORAGESEVER

2010-06-07

Jun 7, 2010 ... almond (Prunus dulcis, Batch) genotypes as revealed by PCR analysis. Yavar Sharafi1*, Jafar Hajilou1, Seyed AbolGhasem Mohammadi2, Mohammad Reza Dadpour1 and Sadollah Eskandari3. 1Department of Horticulture, Faculty of Agriculture, University of Tabriz, Tabriz, 5166614766, Iran.

Supervision of Fed-Batch Fermentations

DEFF Research Database (Denmark)

Gregersen, Lars; Jørgensen, Sten Bay

1999-01-01

Process faults may be detected on-line using existing measurements based upon modelling that is entirely data driven. A multivariate statistical model is developed and used for fault diagnosis of an industrial fed-batch fermentation process. Data from several (25) batches are used to develop...... a model for cultivation behaviour. This model is validated against 13 data sets and demonstrated to explain a significant amount of variation in the data. The multivariate model may directly be used for process monitoring. With this method faults are detected in real time and the responsible measurements...

40 CFR 63.1408 - Aggregate batch vent stream provisions.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Aggregate batch vent stream provisions... § 63.1408 Aggregate batch vent stream provisions. (a) Emission standards. Owners or operators of aggregate batch vent streams at a new or existing affected source shall comply with either paragraph (a)(1...

Insights into crystal growth rates from a study of orbicular granitoids from western Australia

Science.gov (United States)

Zhang, J.; Lee, C. T.

2017-12-01

The purpose of this study is to develop new tools for constraining crystal growth rate in geologic systems. Of interest is the growth of crystals in magmatic systems because crystallization changes the rheology of a magma as well as provides surfaces on which bubbles can nucleate. To explore crystal growth in more detail, we conducted a case study of orbicular granitoids from western Australia. The orbicules occur as spheroids dispersed in a granitic matrix. Most orbicules have at least two to three concentric bands, composed of elongate and radially oriented hornblende surrounded by interstitial plagioclase. We show that mineral modes and hence bulk composition at the scale of the band is homogeneous from rim to core. Crystal number density decreases and crystal size increases from rim to core. These observations suggest that the orbicules crystallized rapidly from rim to core. We hypothesize that the orbicules are blobs of hot dioritic liquid injected into a cold granitic magma and subsequently cooled and solidified. Crystals stop growing when the mass transport rate tends to zero due to the low temperature. We estimated cooling timescales based on conductive cooling models, constraining crystal growth rates to be 10-6 to 10-5 m/s. We also show that the oscillatory banding is controlled by disequilibrium crystallization, wherein hornblende preferentially crystallizes, resulting in the diffusive growth of a chemical boundary layer enriched in plagioclase component, which in turns results in crystallization of plagioclase. We show that the correlation between the width of each crystallization couplet (band) with distance from orbicule rim is linear, with the slope corresponding to the square root of the ratio between chemical diffusivity in the growth medium and thermal diffusivity. We estimate chemical diffusivity of 2*10-7 m2/s, which is remarkably fast for silicate liquids but reasonable for diffusion in hot aqueous fluids, suggesting that crystallization

Scintillation activity in an unirradiated single crystal of 3-hydroxyxanthine

International Nuclear Information System (INIS)

Cooke, D.W.; Jahan, M.S.; Alexander, C. Jr.

1976-01-01

A method of growing single crystals (approximately 4mm long) of 3-hydroxyxanthine is described. Observed scintillations occurring in an unirradiated single crystal of this potent oncogen as the temperature is lowered from 300 to 90 K are shown. It was found that these scintillations occur upon heating or cooling and do not diminish in activity as the number of heating and cooling cycles increase. It was found that a short duration u.v. exposure would terminate the scintillation activity and various attempts (such as annealing and pressure changes) to rejuvenate them were unsuccessful. With these observations in mind speculation is made concerning the mechanisms associated with the production of purine N-oxide derivatives. (U.K.)

Molecular rotation-vibration dynamics of low-symmetric hydrate crystal in the terahertz region.

Science.gov (United States)

Fu, Xiaojian; Wu, Hongya; Xi, Xiaoqing; Zhou, Ji

2014-01-16

The rotational and vibrational dynamics of molecules in copper sulfate pentahydrate crystal are investigated with terahertz dielectric spectra. It is shown that the relaxation-like dielectric dispersion in the low frequency region is related to the reorientation of water molecules under the driving of terahertz electric field, whereas the resonant dispersion can be ascribed to lattice vibration. It is also found that, due to the hydrogen-bond effect, the vibrational mode at about 1.83 THz along [-111] direction softens with decreasing temperature, that is, the crystal expands in this direction when cooled. On the contrary, the mode hardens in the direction perpendicular to [-111] during the cooling process. This contributes to the further understanding of the molecular structure and bonding features of hydrate crystals.

Science Issues Associated with the Use of a Microfluidic Chip Designed Specifically for Protein Crystallization

Science.gov (United States)

Holmes, Anna M.; Monaco, Lisa; Barnes, Cindy; Spearing, Scott; Jenkins, Andy; Johnson, Todd; Mayer, Derek; Cole, Helen

2003-01-01

The Iterative Biological Crystallization team in partnership with Caliper Technologies has produced a prototype microfluidic chip for batch crystallization that has been designed and tested. The chip is designed for the mixing and dispensing of up to five solutions with possible variation of the recipe being delivered to two growth wells. Developments that have led to the successful on-chip crystallization of a few model proteins have required investigative insight into many different areas, including fluid mixing dynamics, surface treatments, quantification and fidelity of reagent delivery. This presentation will encompass the ongoing studies and data accumulated toward these efforts.

The growth of crystals of erbium hydride

International Nuclear Information System (INIS)

Grimshaw, J.A.; Spooner, F.J.; Wilson, C.G.; McQuillan, A.D.

1981-01-01

Crystals of the rare-earth hydride ErH 2 have been produced with face areas greater than a square millimetre and corresponding volumes exceeding those of earlier crystals by orders of magnitude. The hydride, which was produced in bulk polycrystalline form by hydriding erbium metal at 950 0 C, has been examined by optical and X-ray techniques. For material of composition ErH 2 and ErHsub(1.8) the size of the grains and their degree of strain appears to depend more on oxygen contamination during formation and on the subsequent cooling procedure, than on the size of erbium metal crystals in the starting material. (author)

A computer-aided molecular design framework for crystallization solvent design

DEFF Research Database (Denmark)

Karunanithi, Arunprakash T.; Achenie, Luke E.K.; Gani, Rafiqul

2006-01-01

One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem is formu......One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem...... solvent molecules. Solvent design and selection for two types of solution crystallization processes namely cooling crystallization and drowning out crystallization are presented. In the first case study, the design of single compound solvent for crystallization of ibuprofen, which is an important...

Towards establishing a combined rate law of nucleation and crystal growth - The case study of gypsum precipitation

Science.gov (United States)

Rendel, Pedro M.; Gavrieli, Ittai; Wolff-Boenisch, Domenik; Ganor, Jiwchar

2018-03-01

The main obstacle in the formulation of a quantitative rate-model for mineral precipitation is the absence of a rigorous method for coupling nucleation and growth processes. In order to link both processes, we conducted a series of batch experiments in which gypsum nucleation was followed by crystal growth. Experiments were carried out using various stirring methods in several batch vessels made of different materials. In the experiments, the initial degree of supersaturation of the solution with respect to gypsum (Ωgyp) was set between 1.58 and 1.82. Under these conditions, heterogeneous nucleation is the dominant nucleation mode. Based on changes in SO42- concentration with time, the induction time of gypsum nucleation and the following rate of crystal growth were calculated for each experiment. The induction time (6-104 h) was found to be a function of the vessel material, while the rates of crystal growth, which varied over three orders of magnitude, were strongly affected by the stirring speed and its mode (i.e. rocking, shaking, magnetic stirrer, and magnetic impeller). The SO42- concentration data were then used to formulate a forward model that couples the simple rate laws for nucleation and crystal growth of gypsum into a single kinetic model. Accordingly, the obtained rate law is based on classical nucleation theory and heterogeneous crystal growth.

Vitrification and Devitrification of Rigid Amorphous Fraction of PET during Quasi-isothermal Cooling and Heating

Science.gov (United States)

Cebe, Peggy; Chen, Huipeng

2009-03-01

Poly(ethylene terephthalate), PET, was studied by quasi-isothermal (QI) Temperature Modulated Differential Scanning Calorimetry (TMDSC). For the first time, both the temperature dependent crystalline fraction and rigid amorphous fraction (RAF) were quantitatively analyzed during QI cooling and reheating. Specific reversing heat capacity measurements show that most RAF vitrifies step by step during QI cooling after completion of crystallization. Upon subsequent QI reheating, the RAF devitrifies also step by step and only a small RAF of 0.04 remains at 470K, while melting starts above 473K. To obtain the exact temperature of the start of melting, heat capacity measurements were made using subsequent standard DSC heating, after QI cooling. By combining this method with the QI results, the temperature dependent phase fractions were obtained during standard DSC heating. We conclude that RAF completely devitrifies before the temperature reaches the crystal melting endotherm under the conditions used in this work.

Preliminary calculations on the cooling rate of the Renca batholit, Sierra de San Luis, Argentina

International Nuclear Information System (INIS)

Lopez de Luchi, M.G.; Ostera, H.A.; Linares, E; Rosello, E.A

2001-01-01

Cooling rates can be used to constrain the unroofing history of plutonic-metamorphic system. Geocronological cooling rates (Spear and Parrish, 1996) can be unravelled using age calculations on minerals that were open systems and subsequently passed through their closure temperatures (Dodson, 1973) during cooling. Several age determinations on different minerals are needed in order to accurately constrain the cooling path of a pluton (Hodges 1991, Spear and Parrish, 1996 and references therein). Isotopic open-system behaviour in minerals can be modelled as volume diffusion process (Hodges, 1991 and references therein), which depends on the cooling rate of the whole system. We present the first results on the calculation of the cooling rate of the Renca batholith on the basis of the combination of both thermometric calculations and available crystallization and cooling ages (au)

Effect of glass-batch makeup on the melting process

International Nuclear Information System (INIS)

Hrma, Pavel R.; Schweiger, Michael J.; Humrickhouse, Carissa J.; Moody, J. Adam; Tate, Rachel M.; Rainsdon, Timothy T.; Tegrotenhuis, Nathan E.; Arrigoni, Benjamin M.; Marcial, Jose; Rodriguez, Carmen P.; Tincher, Benjamin

2010-01-01

The response of a glass batch to heating is determined by the batch makeup and in turn determines the rate of melting. Batches formulated for a high-alumina nuclear waste to be vitrified in an all-electric melter were heated at a constant temperature-increase rate to determine changes in melting behavior in response to the selection of batch chemicals and silica grain-size as well as the addition of heat-generating reactants. The type of batch materials and the size of silica grains determine how much, if any, primary foam occurs during melting. Small quartz grains, 5 (micro)m in size, caused extensive foaming because their major portion dissolved at temperatures 800 C when batch gases no longer evolved. The exothermal reaction of nitrates with sucrose was ignited at a temperature as low as 160 C and caused a temporary jump in temperature of several hundred degrees. Secondary foam, the source of which is oxygen from redox reactions, occurred in all batches of a limited composition variation involving five oxides, B 2 O 3 , CaO, Li 2 O, MgO, and Na 2 O. The foam volume at the maximum volume-increase rate was a weak function of temperature and melt basicity. Neither the batch makeup nor the change in glass composition had a significant impact on the dissolution of silica grains. The impacts of primary foam generation on glass homogeneity and the rate of melting in large-scale continuous furnaces have yet to be established via mathematical modeling and melter experiments.

Effect Of Glass-Batch Makeup On The Melting Process

International Nuclear Information System (INIS)

Kruger, A.A.; Hrma, P.

2010-01-01

The response of a glass batch to heating is determined by the batch makeup and in turn determines the rate of melting. Batches formulated for a high-alumina nuclear waste to be vitrified in an all-electric melter were heated at a constant temperature-increase rate to determine changes in melting behavior in response to the selection of batch chemicals and silica grain-size as well as the addition of heat-generating reactants. The type of batch materials and the size of silica grains determine how much, if any, primary foam occurs during melting. Small quartz grains, 5 (micro)m in size, caused extensive foaming because their major portion dissolved at temperatures 800 C when batch gases no longer evolved. The exothermal reaction of nitrates with sucrose was ignited at a temperature as low as 160 C and caused a temporary jump in temperature of several hundred degrees. Secondary foam, the source of which is oxygen from redox reactions, occurred in all batches of a limited composition variation involving five oxides, B 2 O 3 , CaO, Li 2 O, MgO, and Na 2 O. The foam volume at the maximum volume-increase rate was a weak function of temperature and melt basicity. Neither the batch makeup nor the change in glass composition had a significant impact on the dissolution of silica grains. The impacts of primary foam generation on glass homogeneity and the rate of melting in large-scale continuous furnaces have yet to be established via mathematical modeling and melter experiments.

Numerical and experimental simulation of mechanical and microstructural transformations in Batch annealing steels

International Nuclear Information System (INIS)

Monsalve, A.; Artigas, A.; Celentano, D.; Melendez, F.

2004-01-01

The heating and cooling curves during batch annealing process of low carbon steel have been modeled using the finite element technique. This has allowed to predict the transient thermal profile for every point of the annealed coils, particularly for the hottest and coldest ones. Through experimental measurements, the results have been adequately validated since a good agreement has been found between experimental values and those predicted by the model. Moreover, an Avrami recrystallization model. Moreover, and Avrami recrystallization model has been coupled to this thermal balance computation. Interrupted annealing experiments have been made by measuring the recrystallized fraction on the extreme points of the coil foe different times. These data gave the possibility to validate the developed recrystallization model through a reasonably good numerical-experimental fittings. (Author) 6 refs

Crystallization and Characterization of a New Magnesium Sulfate Hydrate MgSO4.11H2O

NARCIS (Netherlands)

Genceli, F.E.; Lutz, M.; Spek, A.L.; Witkamp, G.J.

2007-01-01

The MgSO4 crystal hydrate formed below approximately 0 °C was proven to be the undecahydrate, MgSO4 • 11H2O (meridianiite) instead of the reported dodecahydrate MgSO4 • 12H2O. The crystals were grown from solution by eutectic freeze and by cooling crystallization. The crystal structure analysis and

Macromolecular Crystal Growth by Means of Microfluidics

Science.gov (United States)

vanderWoerd, Mark; Ferree, Darren; Spearing, Scott; Monaco, Lisa; Molho, Josh; Spaid, Michael; Brasseur, Mike; Curreri, Peter A. (Technical Monitor)

2002-01-01

We have performed a feasibility study in which we show that chip-based, microfluidic (LabChip(TM)) technology is suitable for protein crystal growth. This technology allows for accurate and reliable dispensing and mixing of very small volumes while minimizing bubble formation in the crystallization mixture. The amount of (protein) solution remaining after completion of an experiment is minimal, which makes this technique efficient and attractive for use with proteins, which are difficult or expensive to obtain. The nature of LabChip(TM) technology renders it highly amenable to automation. Protein crystals obtained in our initial feasibility studies were of excellent quality as determined by X-ray diffraction. Subsequent to the feasibility study, we designed and produced the first LabChip(TM) device specifically for protein crystallization in batch mode. It can reliably dispense and mix from a range of solution constituents into two independent growth wells. We are currently testing this design to prove its efficacy for protein crystallization optimization experiments. In the near future we will expand our design to incorporate up to 10 growth wells per LabChip(TM) device. Upon completion, additional crystallization techniques such as vapor diffusion and liquid-liquid diffusion will be accommodated. Macromolecular crystallization using microfluidic technology is envisioned as a fully automated system, which will use the 'tele-science' concept of remote operation and will be developed into a research facility for the International Space Station as well as on the ground.

Spatial and interannual variability in Baltic sprat batch fecundity

DEFF Research Database (Denmark)

Haslob, H.; Tomkiewicz, Jonna; Hinrichsen, H.H.

2011-01-01

in the central Baltic Sea, namely the Bornholm Basin, Gdansk Deep and Southern Gotland Basin. Environmental parameters such as hydrography, fish condition and stock density were tested in order to investigate the observed variability in sprat fecundity. Absolute batch fecundity was found to be positively related...... to fish length and weight. Significant differences in absolute and relative batch fecundity of Baltic sprat among areas and years were detected, and could partly be explained by hydrographic features of the investigated areas. A non-linear multiple regression model taking into account fish length...... and ambient temperature explained 70% of variability in absolute batch fecundity. Oxygen content and fish condition were not related to sprat batch fecundity. Additionally, a negative effect of stock size on sprat batch fecundity in the Bornholm Basin was revealed. The obtained data and results are important...

Modeling the methane hydrate formation in an aqueous film submitted to steady cooling

Energy Technology Data Exchange (ETDEWEB)

Avendano-Gomez, J.R. [ESIQIE, Laboratorio de Ingenieria Quimica Ambiental, Mexico (Mexico). Inst. Politecnico Nacional; Garcia-Sanchez, F. [Laboratorio de Termodinamica, Mexico (Mexico). Inst. Mexicano del Petroleo; Gurrola, D.V. [UPIBI, Laboratorio de Diseno de Plantas, Mexico (Mexico). Inst. Politecnico Nacional

2008-07-01

Gas hydrates, or clathrate hydrates, are ice-like compounds that results from the kinetic process of crystallization of an aqueous solution supersaturated with a dissolved gas. This paper presented a model that took into account two factors involved in the hydrate crystallization, notably the stochastic nature of crystallization that causes sub-cooling and the heat resulting from the exothermic enthalpy of hydrate formation. The purpose of this study was to model the thermal evolution inside a hydrate forming system which was submitted to an imposed steady cooling. The study system was a cylindrical thin film of aqueous solution at 19 Mpa. The study involved using methane as the hydrate forming molecule. It was assumed that methane was homogeneously dissolved in the aqueous phase. Ethane hydrate was formed through a kinetic process of nucleation and crystallization. In order to predict the onset time of nucleation, the induction time needed to be considered. This paper discussed the probability of nucleation as well as the estimation of the rate of nucleation. It also presented the mathematical model and boundary conditions. These included assumptions and derivation of the model; boundary conditions; initial conditions; and numerical solution of the model equation. It was concluded that the heat source must be considered when investigating crystallization effects. 34 refs., 2 tabs., 2 figs.

Fuzzy batch controller for granular materials

OpenAIRE

Zamyatin Nikolaj; Smirnov Gennadij; Fedorchuk Yuri; Rusina Olga

2018-01-01

The paper focuses on batch control of granular materials in production of building materials from fluorine anhydrite. Batching equipment is intended for smooth operation and timely feeding of supply hoppers at a required level. Level sensors and a controller of an asynchronous screw drive motor are used to control filling of the hopper with industrial anhydrite binders. The controller generates a required frequency and ensures required productivity of a feed conveyor. Mamdani-type fuzzy infer...

Crystal growth of emerald by flux method

International Nuclear Information System (INIS)

Inoue, Mikio; Narita, Eiichi; Okabe, Taijiro; Morishita, Toshihiko.

1979-01-01

Emerald crystals have been formed in two binary fluxes of Li 2 O-MoO 2 and Li 2 O-V 2 O 5 using the slow cooling method and the temperature gradient method under various conditions. In the flux of Li 2 O-MoO 3 carried out in the range of 2 -- 5 of molar ratios (MoO 3 /Li 2 O), emerald was crystallized in the temperature range from 750 to 950 0 C, and the suitable crystallization conditions were found to be the molar ratio of 3 -- 4 and the temperature about 900 0 C. In the flux of Li 2 O-V 2 O 5 carried out in the range of 1.7 -- 5 of molar ratios (V 2 O 5 /Li 2 O), emerald was crystallized in the temperature range from 900 to 1150 0 . The suitable crystals were obtained at the molar ratio of 3 and the temperature range of 1000 -- 1100 0 C. The crystallization temperature rised with an increase in the molar ratio of the both fluxes. The emeralds grown in two binary fluxes were transparent green, having the density of 2.68, the refractive index of 1.56, and the two distinct bands in the visible spectrum at 430 and 600nm. The emerald grown in Li 2 O-V 2 O 5 flux was more bluish green than that grown in Li 2 O-MoO 3 flux. The size of the spontaneously nucleated emerald grown in the former flux was larger than the latter, when crystallized by the slow cooling method. As for the solubility of beryl in the two fluxes, Li 2 O-V 2 O 5 flux was superior to Li 2 O-MoO 3 flux whose small solubility of SiO 2 caused an experimental problem to the temperature gradient method. The suitability of the two fluxes for the crystal growth of emerald by the flux method was discussed from the view point of various properties of above-mentioned two fluxes. (author)

Crystallization from microemulsions ? a novel method for the preparation of new crystal forms of aspartame

Science.gov (United States)

Füredi-Milhofer, Helga; Garti, N.; Kamyshny, A.

1999-03-01

Solubilization and crystallization of the artificial sweetener aspartame (APM), in water/isooctane microemulsions stabilized with sodium diisooctyl sulfosuccinate (AOT) has been investigated. The amount of aspartame that could be solubilized depended primarily on the amount of surfactant and on the temperature. The maximum AOT/aspartame molar ratio at the w/o interface is shown to be 6.2 at 25°C. It was concluded that the dipeptide is located at the w/o interface interspersed between surfactant molecules and that it acts as a cosurfactant. A new crystal form, APM III, was obtained by cooling of hot w/isooctane/AOT microemulsions containing solubilized aspartame. The new crystal form exhibits a distinct X-ray diffraction powder pattern, as well as changes in the FTIR spectra, thermogravimetric and DSC patterns. H-NMR spectra of APM III dissolved in D 2O were identical to the spectrum of commercial aspartame recorded under the same conditions. The new crystal form has greatly improved dissolution kinetics.

Research on AO/FO batch management technology in aircraft production

Directory of Open Access Journals (Sweden)

Yin Haijun

2018-01-01

Full Text Available Based on the analysis of the characteristics and significance of AO/FO in the process of aircraft production, this paper analyzes the format rules of AO/FO batch management from the perspective of technology realization, and details the AO/FO The change of the query and the change status tracking, introduces the AO/FO single-stand status display in the batch management, increases the structure definition of the attribute table in the batch management, and designs the relevant algorithm to store and calculate the batch information. Finally, based on the above theory support AO/FO batch management system successfully used in the production of a machine.

Controlled in meso phase crystallization--a method for the structural investigation of membrane proteins.

Directory of Open Access Journals (Sweden)

Jan Kubicek

Full Text Available We investigated in meso crystallization of membrane proteins to develop a fast screening technology which combines features of the well established classical vapor diffusion experiment with the batch meso phase crystallization, but without premixing of protein and monoolein. It inherits the advantages of both methods, namely (i the stabilization of membrane proteins in the meso phase, (ii the control of hydration level and additive concentration by vapor diffusion. The new technology (iii significantly simplifies in meso crystallization experiments and allows the use of standard liquid handling robots suitable for 96 well formats. CIMP crystallization furthermore allows (iv direct monitoring of phase transformation and crystallization events. Bacteriorhodopsin (BR crystals of high quality and diffraction up to 1.3 Å resolution have been obtained in this approach. CIMP and the developed consumables and protocols have been successfully applied to obtain crystals of sensory rhodopsin II (SRII from Halobacterium salinarum for the first time.

Cooling off with physics

Energy Technology Data Exchange (ETDEWEB)

Clarke, Chris [Unilever R and D (United Kingdom)

2003-08-01

You might think of ice cream as a delicious treat to be enjoyed on a sunny summer's day. However, to the ice-cream scientists who recently gathered in Thessaloniki in Greece for the 2nd International Ice Cream Symposium, it is a complex composite material. Ice cream consists of three dispersed phases: ice crystals, which have a mean size of 50 microns, air bubbles with a diameter of about 70 microns, and fat droplets with a size of 1 micron. These phases are held together by what is called the matrix - not a sci-fi film, but a viscous solution of sugars, milk proteins and polysaccharides. The microstructure, and hence the texture that you experience when you eat ice cream, is created in a freezing process that has remained fundamentally unchanged since the first ice-cream maker was patented in the 1840s. The ingredients - water, milk protein, fat, sugar, emulsifiers, stabilizers, flavours and a lot of air - are mixed together before being pasteurized and homogenized. They are then pumped into a cylinder that is cooled from the outside with a refrigerant. As the mixture touches the cylinder wall it freezes and forms ice crystals, which are quickly scraped off by a rotating blade. The blade is attached to a beater that disperses the ice crystals into the mixture. At the same time, air is injected and broken down into small bubbles by the shear that the beater generates. As the mixture passes along the cylinder, the number of ice crystals increases and its temperature drops. As a result, the viscosity of the mixture increases, so that more energy input is needed to rotate the beater. This energy is dissipated as heat, and when the ice cream reaches about -6 deg. C the energy input through the beater equals the energy removed as heat by the refrigerant. The process therefore becomes self-limiting and it is not possible to cool the ice cream any further. However, at -6 deg. C the microstructure is unstable. The ice cream therefore has to be removed from the freezer

Heat transfer analytical models for the rapid determination of cooling time in crystalline thermoplastic injection molding and experimental validation

Science.gov (United States)

Didier, Delaunay; Baptiste, Pignon; Nicolas, Boyard; Vincent, Sobotka

2018-05-01

Heat transfer during the cooling of a thermoplastic injected part directly affects the solidification of the polymer and consequently the quality of the part in term of mechanical properties, geometric tolerance and surface aspect. This paper proposes to mold designers a methodology based on analytical models to provide quickly the time to reach the ejection temperature depending of the temperature and the position of cooling channels. The obtained cooling time is the first step of the thermal conception of the mold. The presented methodology is dedicated to the determination of solidification time of a semi-crystalline polymer slab. It allows the calculation of the crystallization time of the part and is based on the analytical solution of the Stefan problem in a semi-infinite medium. The crystallization is then considered as a phase change with an effective crystallization temperature, which is obtained from Fast Scanning Calorimetry (FSC) results. The crystallization time is then corrected to take the finite thickness of the part into account. To check the accuracy of such approach, the solidification time is calculated by solving the heat conduction equation coupled to the crystallization kinetics of the polymer. The impact of the nature of the contact between the polymer and the mold is evaluated. The thermal contact resistance (TCR) appears as significant parameter that needs to be taken into account in the cooling time calculation. The results of the simplified model including or not TCR are compared in the case of a polypropylene (PP) with experiments carried out with an instrumented mold. Then, the methodology is applied for a part made with PolyEtherEtherKetone (PEEK).

Ejection of Coulomb Crystals from a Linear Paul Ion Trap for Ion-Molecule Reaction Studies.

Science.gov (United States)

Meyer, K A E; Pollum, L L; Petralia, L S; Tauschinsky, A; Rennick, C J; Softley, T P; Heazlewood, B R

2015-12-17

Coulomb crystals are being increasingly employed as a highly localized source of cold ions for the study of ion-molecule chemical reactions. To extend the scope of reactions that can be studied in Coulomb crystals-from simple reactions involving laser-cooled atomic ions, to more complex systems where molecular reactants give rise to multiple product channels-sensitive product detection methodologies are required. The use of a digital ion trap (DIT) and a new damped cosine trap (DCT) are described, which facilitate the ejection of Coulomb-crystallized ions onto an external detector for the recording of time-of-flight (TOF) mass spectra. This enables the examination of reaction dynamics and kinetics between Coulomb-crystallized ions and neutral molecules: ionic products are typically cotrapped, thus ejecting the crystal onto an external detector reveals the masses, identities, and quantities of all ionic species at a selected point in the reaction. Two reaction systems are examined: the reaction of Ca(+) with deuterated isotopologues of water, and the charge exchange between cotrapped Xe(+) with deuterated isotopologues of ammonia. These reactions are examples of two distinct types of experiment, the first involving direct reaction of the laser-cooled ions, and the second involving reaction of sympathetically-cooled heavy ions to form a mixture of light product ions. Extensive simulations are conducted to interpret experimental results and calculate optimal operating parameters, facilitating a comparison between the DIT and DCT approaches. The simulations also demonstrate a correlation between crystal shape and image shape on the detector, suggesting a possible means for determining crystal geometry for nonfluorescing ions.

Hydrothermal syntheses and single crystal structural ...

Indian Academy of Sciences (India)

Unknown

Colourless. 84 lined stainless steel bomb. After heating in a pro- grammable oven at the respective temperatures and autogenous pressures for the notified time scale, cooling was carried out on a ramp of 10°C/h to room temperature. The crystals were collected by filtration, washed with, deionized water followed by diethyl-.

Variance bias analysis for the Gelbard's batch method

Energy Technology Data Exchange (ETDEWEB)

Seo, Jae Uk; Shim, Hyung Jin [Seoul National Univ., Seoul (Korea, Republic of)

2014-05-15

In this paper, variances and the bias will be derived analytically when the Gelbard's batch method is applied. And then, the real variance estimated from this bias will be compared with the real variance calculated from replicas. Variance and the bias were derived analytically when the batch method was applied. If the batch method was applied to calculate the sample variance, covariance terms between tallies which exist in the batch were eliminated from the bias. With the 2 by 2 fission matrix problem, we could calculate real variance regardless of whether or not the batch method was applied. However as batch size got larger, standard deviation of real variance was increased. When we perform a Monte Carlo estimation, we could get a sample variance as the statistical uncertainty of it. However, this value is smaller than the real variance of it because a sample variance is biased. To reduce this bias, Gelbard devised the method which is called the Gelbard's batch method. It has been certificated that a sample variance get closer to the real variance when the batch method is applied. In other words, the bias get reduced. This fact is well known to everyone in the MC field. However, so far, no one has given the analytical interpretation on it.

Bubble formation upon crystallization of high nitrogen iron base alloys

International Nuclear Information System (INIS)

Svyazhin, A.G.; Sivka, E.; Skuza, Z.

2000-01-01

A study is made into the conditions of nitrogen bubble formation during crystallization of unalloyed iron, alloys of Fe-O, Fe-O-S systems, steels 1Kh13, 0Kh18N9 and a two-phase Fe-11%Cr-1%Mo-0.2%V steel. It is revealed that the amount of bubbles in a high nitrogen steel casting increases with a degree of nitrogen supersaturation and decreases with a cooling rate growth and with a rise of surfactant concentration in the metal. In sound castings a nitrogen content can be increased due to a cooling rate growth, nitrogen dilution with inert gas, an increase of nitrogen pressure during crystallization as well as due to the introduction of such surfactants as sulphur, selenium, tellurium, tin [ru

Effects of quartz on crystallization behavior of mold fluxes and microstructural characteristics of flux film.

Science.gov (United States)

Lei, Liu; Xiuli, Han; Mingduo, Li; Di, Zhang

2018-01-01

Mold fluxes are mainly prepared using cement clinker, quartz, wollastonite, borax, fluorite, soda ash and other mineral materials. Quartz, as one of the most common and essential materials, was chosen for this study to analyze itseffects on crystallization temperature, critical cooling rate, crystal incubation time, crystallization ratio and phases of flux film. We used the research methods of process mineralogy with the application of the single hot thermocouple technique, heat flux simulator, polarizing microscope, X-ray diffraction, etc. Results: By increasing the quartz content from 16 mass% to 24 mass%, the crystallization temperature, critical cooling rate and crystallization ratio of flux film decreased, and the crystal incubation time was extended. Meanwhile, the mineralogical structure of the flux film changed, with a large amount of wollastonite precipitation and a significant decrease in the cuspidine content until it reached zero. This showed a steady decline in the heat transfer control capacity of the flux film. The reason for the results above is that, by increasing the quartz content, the silicon-oxygen tetrahedron network structure promoted a rise in viscosity and restrained ion migration, inhibiting crystal nucleation and growth, leading to the weakening of the crystallization and a decline in the crystallization ratio.

A Study of the Batch Annealing of Cold-Rolled HSLA Steels Containing Niobium or Titanium

Science.gov (United States)

Fang, Chao; Garcia, C. Isaac; Choi, Shi-Hoon; DeArdo, Anthony J.

2015-08-01

The batch annealing behavior of two cold-rolled, microalloyed HSLA steels has been studied in this program. One steel was microalloyed with niobium while the other with titanium. A successfully batch annealed steel will exhibit minimum variation in properties along the length of the coil, even though the inner and outer wraps experience faster heating and cooling rates and lower soaking temperatures, i.e., the so-called "cold spot" areas, than the mid-length portion of the coil, i.e., the so-called "hot spot" areas. The variation in strength and ductility is caused by differences in the extent of annealing in the different areas. It has been known for 30 years that titanium-bearing HSLA steels show more variability after batch annealing than do the niobium-bearing steels. One of the goals of this study was to try to explain this observation. In this study, the annealing kinetics of the surface and center layers of the cold-rolled sheet were compared. The surface and center layers of the niobium steel and the surface layer of the titanium steel all showed similar annealing kinetics, while the center layer of the titanium steel exhibited much slower kinetics. Metallographic results indicate that the stored energy of the cold-rolled condition, as revealed by grain center sub-grain boundary density, appeared to strongly influence the annealing kinetics. The kinetics were followed by the Kernel Average Misorientation reconstruction of the microstructure at different stages on annealing. Possible pinning effects caused by microalloy precipitates were also considered. Methods of improving uniformity and increasing kinetics, involving optimizing both hot-rolled and cold-rolled microstructure, are suggested.

Pyroelectric Study on Dipolar Alignment in 0.69Pb(Mg1/3Nb2/3)O3-0.31PbTiO3 Single Crystals

Institute of Scientific and Technical Information of China (English)

ZHAO Liang; SHEN Ming-Rong; CAO Wen-Wu

2012-01-01

Pyroelectric measurements are conducted during zero-Geld heating in [001], [110] and [111] poled 0.69Pb(Mg1/3 Nb2/3)O3-0.31PbTiO3 single crystals. Compared to the room-temperature-poled samples, the crystals poled by using the Rield cooling method show broad but well recognizable pyroelectric current peaks near 190℃, which is much higher than the Curie point (126℃) of the crystal. We propose that this peak of the crystals poled by field-cooling above the Curie point is ascribed to the order-disorder transition of the dipoles in polar nano-regions formed at the Burns temperature.%Pyroelectric measurements are conducted during zero-field heating in [001],[110] and [111] poled 0.69Pb(Mg1/3Nb2/3)O3-0.31PbTiO3 single crystals.Compared to the room-temperature-poled samples,the crystals poled by using the field cooling method show broad but well recognizable pyroelectric current peaks near 190℃,which is much higher than the Curie point (126℃) of the crystal.We propose that this peak of the crystals poled by field-cooling above the Curie point is ascribed to the order-disorder transition of the dipoles in polar nano-regions formed at the Burns temperature.

The influence of cooling parameters on the speed of continuous steel casting

Science.gov (United States)

Tirian, G. O.; Gheorghiu, C. A.; Hepuţ, T.; Chioncel, C. P.

2018-01-01

This paper analyzes the cooling parameters of the continuous casting speed. In the researches carried out we aimed to establish some correlation equations between the parameters characterizing the continuous casting process, the temperature of the steel at the entrance to the crystallizer, the superheating of the steel and the flow of the cooling water in the crystallizer and different zones of the secondary cooling. Parallel to these parameters were also the values for the casting speed. The research was made for the casting of round ϕ270mm semi-finished steel products. The steel was developed in an electric EBT furnace with a capacity of 100t, treated in L.F. (Ladle - Furnace) and VD (Vacuum-Degassing) and poured in a 5-wire continuous casting plant. The obtained data was processed in MATLAB using three types of correlation equations. The obtained results are presented both in the analytical and graphical form, each correlation being analyzed from the technological point of view, indicating the optimal values for the independent parameters monitored. In the analysis we present a comparison between the results obtained after the three types of equations for each correlation.

40 CFR 63.1322 - Batch process vents-reference control technology.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Batch process vents-reference control technology. 63.1322 Section 63.1322 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Batch process vents—reference control technology. (a) Batch process vents. The owner or operator of a...

The nature and dynamic of phase transitions during cooling - warming of garlic cell sap

Directory of Open Access Journals (Sweden)

А. Т. Ходько

2015-04-01

Full Text Available To identify the type of phase transition during cooling-warming in the garlic cell sap by cryomicroscopy of samples in transmitted light phenomenon of critical opalescence was recorded. Critical state is peculiar only for phase transitions between the isotropic mediums. This fact gives grounds to include phase transition in the investigated system to liquid-liquid type, which proceeds according to spinodal mechanism and nucleus growth mechanism. During rapid cooling cracking of the samples due to high internal stresses (in contrast to the slow cooling was observed. After the phase transition during cooling rouglydispersed system – highly concentrated emulsion-gel was formed. Signs of crystallization in the system under the studied conditions were not found.

The effect of oxygen fugacity on the rheological evolution of crystallizing basaltic melts

Science.gov (United States)

Kolzenburg, S.; Di Genova, D.; Giordano, D.; Hess, K. U.; Dingwell, D. B.

2018-04-01

Storage and transport of silicate melts in the Earth's crust and their emplacement on the planet's surface occur almost exclusively at sub-liquidus temperatures. At these conditions, the melts undergo crystallization under a wide range of cooling-rates, deformation-rates, and oxygen fugacities (fO2). Oxygen fugacity is known to influence the thermodynamics and kinetics of crystallization in magmas and lavas. Yet, its influence on sub-liquidus rheology remains largely uncharted. We present the first rheological characterization of crystallizing lavas along natural cooling paths and deformation-rates and at varying fO2. Specifically, we report on apparent viscosity measurements for two crystallizing magmatic suspensions 1) at log ⁡ fO2 of -9.15 (quartz-fayalite-magnetite buffer, QFM, -2.1) and 2) in air. These fugacities span a range of reduced to oxidized conditions pertinent to magma migration and lava emplacement. We find that: 1) crystallization at constant cooling-rates results in a quasi-exponential increase in the apparent viscosity of the magmatic suspensions until they achieve their rheological cut off temperature (Tcutoff), where the melt effectively solidifies 2) the rheological departure and Tcutoff increase with increasing fO2 and 3) increasing fO2 results in decreased crystallization-rates. Based on the experimental results and by comparison with previous rheological isothermal studies we propose a generalisation of the effect of fO2 on the dynamic rheological evolution of natural magmatic and volcanic suspensions. We further discuss the implications for magmatic transport in plumbing and storage systems (e.g. conduits, dikes and magma chambers) and during lava flow emplacement.

A PAT-based qualification of pharmaceutical excipients produced by batch or continuous processing.

Science.gov (United States)

Hertrampf, A; Müller, H; Menezes, J C; Herdling, T

2015-10-10

Pharmaceutical excipients have an influence on the main requirements for medicinal products (viz., quality, safety and efficacy) but also on their manufacturability. During product lifecycle it may become necessary to introduce minor changes (e.g., to continuously improve it) or major changes in the validated process (e.g., moving it to a new production site, replacing process version or even disruptively changing processing type). Those changes can influence the critical to quality attributes of the product. Therefore, it is important to enhance process understanding to avoid the risk of any significant quality changes. Process analytical technology can support better decision making and risk-management as required in quality by design - viz., by many pharmaceutical regulatory authorities. This study compares the quality of the pharmaceutical excipient sodium carbonate (anhydrous) produced either in a batch or a continuous process. For continuous processing two different production lines were available that differed on the dryer and crystallizer types used. Therefore their influence on critical to quality attributes of sodium carbonate was investigated for each of the three processing alternatives. The overall goal was to identify which of the continuous processes ensures a similar product quality to batch processing. Namely, changes on chemical and physical attributes of the product were investigated with Raman spectroscopy, laser diffraction and X-ray powder diffraction. Principal component analysis, a very common multivariate analysis technique, was applied to extract relevant information from small differences at multiple spectral regions from samples from each process type and from each analytical technique used. Changing processing from batch to continuous improved consistency of certain attributes (e.g., particle size distribution) but affected others. However, the increased process/product knowledge gained can lead to an enhanced control strategy and

Batch-to-Batch Quality Consistency Evaluation of Botanical Drug Products Using Multivariate Statistical Analysis of the Chromatographic Fingerprint

OpenAIRE

Xiong, Haoshu; Yu, Lawrence X.; Qu, Haibin

2013-01-01

Botanical drug products have batch-to-batch quality variability due to botanical raw materials and the current manufacturing process. The rational evaluation and control of product quality consistency are essential to ensure the efficacy and safety. Chromatographic fingerprinting is an important and widely used tool to characterize the chemical composition of botanical drug products. Multivariate statistical analysis has showed its efficacy and applicability in the quality evaluation of many ...

Fuzzy batch controller for granular materials

Directory of Open Access Journals (Sweden)

Zamyatin Nikolaj

2018-01-01

Full Text Available The paper focuses on batch control of granular materials in production of building materials from fluorine anhydrite. Batching equipment is intended for smooth operation and timely feeding of supply hoppers at a required level. Level sensors and a controller of an asynchronous screw drive motor are used to control filling of the hopper with industrial anhydrite binders. The controller generates a required frequency and ensures required productivity of a feed conveyor. Mamdani-type fuzzy inference is proposed for controlling the speed of the screw that feeds mixture components. As related to production of building materials based on fluoride anhydrite, this method is used for the first time. A fuzzy controller is proven to be effective in controlling the filling level of the supply hopper. In addition, the authors determined optimal parameters of the batching process to ensure smooth operation and production of fluorine anhydrite materials of specified properties that can compete with gypsum-based products.

SEPARATION OF CsCl FROM LiCl-CsCl MOLTEN SALT BY COLD FINGER MELT CRYSTALLIZATION

Directory of Open Access Journals (Sweden)

JOSHUA R. VERSEY

2014-06-01

Full Text Available This study provides a fundamental understanding of a cold finger melt crystallization technique by exploring the heat and mass transfer processes of cold finger separation. A series of experiments were performed using a simplified LiCl-CsCl system by varying initial CsCl concentrations (1, 3, 5, and 7.5 wt%, cold finger cooling rates (7.4, 9.8, 12.3, and 14.9 L/min, and separation times (5, 10, 15, and 30 min. Results showed a potential recycling rate of 0.36 g/min with a purity of 0.33 wt% CsCl in LiCl. A CsCl concentrated drip formation was found to decrease crystal purity especially for smaller crystal formations. Dimensionless heat and mass transfer correlations showed that separation production is primarily influenced by convective transfer controlled by cooling gas flow rate, where correlations are more accurate for slower cooling gas flow rates.

Dynamic crystallization of a eucrite basalt. [achondrite textural features produced by superheating and differing cooling rates

Science.gov (United States)

Walker, D.; Powell, M. A.; Hays, J. F.; Lofgren, G. E.

1978-01-01

The textural features produced in Stannern, a non-porpyritic representative of the eucrite basaltic achondrite class of meteorite, at differing cooling rates and various degrees of initial superheating were studied. Textures produced from mildly superheated melts were found to be fasciculate rather than porphyritic as the result of the cosaturated bulk chemistry of Stannern. The qualitative type of texture apparently depends mainly on the degree of initial superheating, whereas cooling rate exerts a strong influence on the coarseness of texture. Increasing the degree of superheating produces textures from intergranular/subophitic to fasciculate/porphyritic. With initial superheating to 1200 deg C the transition to quasi-porphyritic is controlled by cooling rate, but the development of phenocrysts is merely an overprint on the fasciculate background texture of the groundmass. The suppression of fasciculate texture is completed by a decrease of the degree of initial superheating below the plagioclast entry and suppression of quasi-porphyritic texture is completed by decrease of the degree of initial superheating below pyroxene entry; these qualitative changes do not seem to be produced by changes of cooling rate. A grain size/cooling rate dependence has been used to deduce the cooling rate of fasciculate-textured Stannern clasts (10.1 to 100 deg C/hr).

Evaluation of moderately cooled pure NaI as a scintillator for position-sensitive PET detectors

International Nuclear Information System (INIS)

Wear, J.A.; Karp, J.S.; Haigh, A.T.; Freifelder, R.

1996-01-01

A new evaluation of pure NaI has been performed to determine if moderate cooling would lead to better performance than that of existing, activated NaI(Tl) position-sensitive detectors, particularly at high countrates. Using a freezer, an initial effort was performed to cool the crystal assembly to -90 C (183 K). At this temperature, pure NaI has a decay constant of 35 nsec, a light output which is about 20% that of room temperature NaI(Tl), and an energy resolution of 15%. For the PET applications the signal of room temperature (25 C) NaI(Tl) is normally pulse clipped, reducing the light output to 40% of the unclipped signal and yielding an energy resolution of 10.5%. Since the long decay of NaI(Tl) causes it to suffer more significantly than pure NaI from pre-pulse pileup, the difference in energy resolution between the two crystals at high countrates will be reduced. Also, a significantly shorter trigger deadtime with pure NaI will lead to a reduction in coincidence deadtime losses in PET. Computer simulations of large-area crystals operating at high countrates have been performed to quantify their trigger deadtime behavior and position resolution as a function of light output and pulse decay time. Having gained experience with the practical issues of cooling large crystals, measurements of position resolution have been performed with a NaI bar detector of similar geometry to the NaI(Tl) detectors in use in the PENN-PET scanner

Operation strategy of industrial crystallization for the production of 2,3,4,4'-tetrahydroxybenzophenon

Energy Technology Data Exchange (ETDEWEB)

Kim, Do Yeon; Yang, Dae Ryook [Korea University, Seoul (Korea, Republic of)

2015-07-15

To improve the filterability of hydroxybenzophenone crystal, a cooling strategy for the cooling crystallization process is investigated by examining the solubility and growth kinetics of hydroxybenzophenone. The operating strategy is divided into two steps. The first step is to generate the seed by dissolving the raw material and by changing operating conditions. The second step is to grow seeds to the product with desired crystal size distribution. For each part, an operating strategy has been proposed based on the solid-liquid phase equilibrium data in a ternary system and growth kinetic experimental results. The strategy for the first step is experimentally determined under various operating conditions, and the second one is determined by theoretical modeling and model-based optimization. The average crystal size resulting from the proposed strategy has been improved and the filterability has been enhanced compared to an existing strategy used in the industry.

Operation strategy of industrial crystallization for the production of 2,3,4,4'-tetrahydroxybenzophenon

International Nuclear Information System (INIS)

Kim, Do Yeon; Yang, Dae Ryook

2015-01-01

To improve the filterability of hydroxybenzophenone crystal, a cooling strategy for the cooling crystallization process is investigated by examining the solubility and growth kinetics of hydroxybenzophenone. The operating strategy is divided into two steps. The first step is to generate the seed by dissolving the raw material and by changing operating conditions. The second step is to grow seeds to the product with desired crystal size distribution. For each part, an operating strategy has been proposed based on the solid-liquid phase equilibrium data in a ternary system and growth kinetic experimental results. The strategy for the first step is experimentally determined under various operating conditions, and the second one is determined by theoretical modeling and model-based optimization. The average crystal size resulting from the proposed strategy has been improved and the filterability has been enhanced compared to an existing strategy used in the industry

The cryogenic cooling program in high-heat-load optics at the Advanced Photon Source

International Nuclear Information System (INIS)

Rogers, C.S.

1993-07-01

This paper describes some of the aspects of the cryogenic optics program at the Advanced Photon Source (APS). A liquid-nitrogen-cooled, high-vacuum, double crystal monochromator is being fabricated at Argonne National Laboratory (ANL). A pumping system capable of delivering a variable flow rate of up to 10 gallons per minute of pressurized liquid nitrogen and removing 5 kilowatts of x-ray power is also being constructed. This specialized pumping system and monochromator will be used to test the viability of cryogenically cooled, high-heat-load synchrotron optics. It has been determined that heat transfer enhancement will be required for optics used with APS insertion devices. An analysis of a porous-matrix-enhanced monochromator crystal is presented. For the particular case investigated, a heat transfer enhancement factor of 5 to 6 was calculated

History based batch method preserving tally means

International Nuclear Information System (INIS)

Shim, Hyung Jin; Choi, Sung Hoon

2012-01-01

In the Monte Carlo (MC) eigenvalue calculations, the sample variance of a tally mean calculated from its cycle-wise estimates is biased because of the inter-cycle correlations of the fission source distribution (FSD). Recently, we proposed a new real variance estimation method named the history-based batch method in which a MC run is treated as multiple runs with small number of histories per cycle to generate independent tally estimates. In this paper, the history-based batch method based on the weight correction is presented to preserve the tally mean from the original MC run. The effectiveness of the new method is examined for the weakly coupled fissile array problem as a function of the dominance ratio and the batch size, in comparison with other schemes available

Kinetics of sugars consumption and ethanol inhibition in carob pulp fermentation by Saccharomyces cerevisiae in batch and fed-batch cultures.

Science.gov (United States)

Lima-Costa, Maria Emília; Tavares, Catarina; Raposo, Sara; Rodrigues, Brígida; Peinado, José M

2012-05-01

The waste materials from the carob processing industry are a potential resource for second-generation bioethanol production. These by-products are small carob kibbles with a high content of soluble sugars (45-50%). Batch and fed-batch Saccharomyces cerevisiae fermentations of high density sugar from carob pods were analyzed in terms of the kinetics of sugars consumption and ethanol inhibition. In all the batch runs, 90-95% of the total sugar was consumed and transformed into ethanol with a yield close to the theoretical maximum (0.47-0.50 g/g), and a final ethanol concentration of 100-110 g/l. In fed-batch runs, fresh carob extract was added when glucose had been consumed. This addition and the subsequent decrease of ethanol concentrations by dilution increased the final ethanol production up to 130 g/l. It seems that invertase activity and yeast tolerance to ethanol are the main factors to be controlled in carob fermentations. The efficiency of highly concentrated carob fermentation makes it a very promising process for use in a second-generation ethanol biorefinery.

Performance analysis of solar air cooled double effect LiBr/H2O absorption cooling system in subtropical city

International Nuclear Information System (INIS)

Li, Zeyu; Ye, Xiangyang; Liu, Jinping

2014-01-01

Highlights: • The meteorological data during the working period of air conditioning was measured. • The suitable working range of collector temperature of system was gotten. • The characteristic of hourly and monthly total efficiency of system were obtained. • The yearly performance of system was calculated. - Abstract: Due to the absence of cooling tower and independent on water, the air cooled solar double effect LiBr/H 2 O absorption cooling system is more convenient to be used in commercial building and household use. The performance with collector temperature is an important field for such system. The paper mainly deals with the performance with collector temperature for the solar air cooled double effect LiBr/H 2 O absorption cooling system in subtropical city. The parameters of system are: aperture area of collector array is 27 m 2 , tilted angle of collector with respect to the horizontal plane is 20 toward to south evaporator temperature is 5 °C and the cooling capacity is 20 kW. The simulation is based on the meteorological data of monthly typical day which was summarized from a year round measured data. A corresponding parametric model was developed. The hourly and average performance with the collector temperature for monthly typical day was obtained and discussed. It was found that the suitable working range of inlet temperature of collector is 110–130 °C to improve performance and lower the risk of crystallization. The difference of hourly total efficiency in 9:00–16:00 is less, and the monthly total efficiency from May to October is approximate. The yearly performance of system including total efficiency, cooling capacity per area of collector and solar fraction was given. Furthermore, the effect of effectiveness of heat exchanger and pressure drop on total efficiency and solar fraction was studied and compared. The paper can serve as a preliminary investigation of solar air cooled double effect LiBr/H 2 O absorption cooling system in

About Small Streams and Shiny Rocks: Macromolecular Crystal Growth in Microfluidics

Science.gov (United States)

vanderWoerd, Mark; Ferree, Darren; Spearing, Scott; Monaco, Lisa; Molho, Josh; Spaid, Michael; Brasseur, Mike; Curreri, Peter A. (Technical Monitor)

2002-01-01

We are developing a novel technique with which we have grown diffraction quality protein crystals in very small volumes, utilizing chip-based, microfluidic ("LabChip") technology. With this technology volumes smaller than achievable with any laboratory pipette can be dispensed with high accuracy. We have performed a feasibility study in which we crystallized several proteins with the aid of a LabChip device. The protein crystals are of excellent quality as shown by X-ray diffraction. The advantages of this new technology include improved accuracy of dispensing for small volumes, complete mixing of solution constituents without bubble formation, highly repeatable recipe and growth condition replication, and easy automation of the method. We have designed a first LabChip device specifically for protein crystallization in batch mode and can reliably dispense and mix from a range of solution constituents. We are currently testing this design. Upon completion additional crystallization techniques, such as vapor diffusion and liquid-liquid diffusion will be accommodated. Macromolecular crystallization using microfluidic technology is envisioned as a fully automated system, which will use the 'tele-science' concept of remote operation and will be developed into a research facility aboard the International Space Station.

Batch calculations in CalcHEP

International Nuclear Information System (INIS)

Pukhov, A.

2003-01-01

CalcHEP is a clone of the CompHEP project which is developed by the author outside of the CompHEP group. CompHEP/CalcHEP are packages for automatic calculations of elementary particle decay and collision properties in the lowest order of perturbation theory. The main idea prescribed into the packages is to make available passing on from the Lagrangian to the final distributions effectively with a high level of automation. According to this, the packages were created as a menu driven user friendly programs for calculations in the interactive mode. From the other side, long-time calculations should be done in the non-interactive regime. Thus, from the beginning CompHEP has a problem of batch calculations. In CompHEP 33.23 the batch session was realized by mean of interactive menu which allows to the user to formulate the task for batch. After that the not-interactive session was launched. This way is too restricted, not flexible, and leads to doubling in programming. In this article I discuss another approach how one can force an interactive program to work in non-interactive mode. This approach was realized in CalcHEP 2.1 disposed on http://theory.sinp.msu.ru/~pukhov/calchep.html

Method for single crystal growth of photovoltaic perovskite material and devices

Science.gov (United States)

Huang, Jinsong; Dong, Qingfeng

2017-11-07

Systems and methods for perovskite single crystal growth include using a low temperature solution process that employs a temperature gradient in a perovskite solution in a container, also including at least one small perovskite single crystal, and a substrate in the solution upon which substrate a perovskite crystal nucleates and grows, in part due to the temperature gradient in the solution and in part due to a temperature gradient in the substrate. For example, a top portion of the substrate external to the solution may be cooled.

Batch fabrication of polymer microfluidic cartridges for QCM sensor packaging by direct bonding

Science.gov (United States)

Sandström, Niklas; Zandi Shafagh, Reza; Gylfason, Kristinn B.; Haraldsson, Tommy; van der Wijngaart, Wouter

2017-12-01

Quartz crystal microbalance (QCM) sensing is an established technique commonly used in laboratory based life-science applications. However, the relatively complex, multi-part design and multi-step fabrication and assembly of state-of-the-art QCM cartridges make them unsuited for disposable applications such as point-of-care (PoC) diagnostics. In this work, we present the uncomplicated manufacturing of QCMs in polymer microfluidic cartridges. Our novel approach comprises two key innovations: the batch reaction injection molding of microfluidic parts; and the integration of the cartridge components by direct, unassisted bonding. We demonstrate molding of batches of 12 off-stoichiometry thiol-ene epoxy polymer (OSTE+) polymer parts in a single molding cycle using an adapted reaction injection molding process; and the direct bonding of the OSTE+  parts to other OSTE+  substrates, to printed circuit boards, and to QCMs. The microfluidic QCM OSTE+  cartridges were successfully evaluated in terms of liquid sealing as well as electrical properties, and the sensor performance characteristics are on par with those of a commercially available QCM biosensor cartridge. The simplified manufacturing of QCM sensors with maintained performance potentializes novel application areas, e.g. as disposable devices in a point of care setting. Moreover, our results can be extended to simplifying the fabrication of other microfluidic devices with multiple heterogeneously integrated components.

Combination of a Nd:YAG laser and a liquid cooling device to (Zr53Cu30Ni9Al8)Si0.5 bulk metallic glass welding

International Nuclear Information System (INIS)

Wang, H.S.; Chen, H.G.; Jang, J.S.C.; Chiou, M.S.

2010-01-01

Research highlights: → A liquid cooling device (LCD) helps to produce a lower initial welding temperature. → A lower initial welding temperature leads to a faster welding thermal cycle (WTC). → A faster WTC produces a crystallization free weld for a laser welded Zr-based BMG. - Abstract: Using pre-selected welding parameters, a crystallization-free weld for (Zr 53 Cu 30 Ni 9 Al 8 )Si 0.5 bulk metallic glass (BMG) was successfully produced by adopting a Nd:YAG pulse laser in combination with a liquid cooling device (LCD). When a LCD was employed, a faster cooling rate and shorter retention time for the crystallization temperature interval were produced, thus, no crystallization was observed in the weld fusion zone (WFZ) or heat affected zone (HAZ). The hardness in those areas did not differ significantly in comparison to the parent material (PM). For the room temperature laser weld (LCD was not employed), HAZ crystallization seemed unavoidable, although no crystallization occurred within the WFZ. The major crystalline phase in the HAZ was identified as Zr 2 Cu. When the precipitates were greater in the crystallized area (i.e., HAZ), cracks were more likely to form, thus, hardness in the area was decreased.

Crystal nucleation in metallic alloys using x-ray radiography and machine learning

Science.gov (United States)

Arteta, Carlos; Lempitsky, Victor

2018-01-01

The crystallization of solidifying Al-Cu alloys over a wide range of conditions was studied in situ by synchrotron x-ray radiography, and the data were analyzed using a computer vision algorithm trained using machine learning. The effect of cooling rate and solute concentration on nucleation undercooling, crystal formation rate, and crystal growth rate was measured automatically for thousands of separate crystals, which was impossible to achieve manually. Nucleation undercooling distributions confirmed the efficiency of extrinsic grain refiners and gave support to the widely assumed free growth model of heterogeneous nucleation. We show that crystallization occurred in temporal and spatial bursts associated with a solute-suppressed nucleation zone. PMID:29662954

Rapid cooling rates at an active mid-ocean ridge from zircon thermochronology

Science.gov (United States)

Schmitt, Axel K.; Perfit, Michael R.; Rubin, Kenneth H.; Stockli, Daniel F.; Smith, Matthew C.; Cotsonika, Laurie A.; Zellmer, Georg F.; Ridley, W. Ian

2011-01-01

Oceanic spreading ridges are Earth's most productive crust generating environment, but mechanisms and rates of crustal accretion and heat loss are debated. Existing observations on cooling rates are ambiguous regarding the prevalence of conductive vs. convective cooling of lower oceanic crust. Here, we report the discovery and dating of zircon in mid-ocean ridge dacite lavas that constrain magmatic differentiation and cooling rates at an active spreading center. Dacitic lavas erupted on the southern Cleft segment of the Juan de Fuca ridge, an intermediate-rate spreading center, near the intersection with the Blanco transform fault. Their U–Th zircon crystallization ages (29.3-4.6+4.8 ka; 1δ standard error s.e.) overlap with the (U–Th)/He zircon eruption age (32.7 ± 1.6 ka) within uncertainty. Based on similar 238U-230Th disequilibria between southern Cleft dacite glass separates and young mid-ocean ridge basalt (MORB) erupted nearby, differentiation must have occurred rapidly, within ~ 10–20 ka at most. Ti-in-zircon thermometry indicates crystallization at 850–900 °C and pressures > 70–150 MPa are calculated from H2O solubility models. These time-temperature constraints translate into a magma cooling rate of ~ 2 × 10-2 °C/a. This rate is at least one order-of-magnitude faster than those calculated for zircon-bearing plutonic rocks from slow spreading ridges. Such short intervals for differentiation and cooling can only be resolved through uranium-series (238U–230Th) decay in young lavas, and are best explained by dissipating heat convectively at high crustal permeability.

Efficient Havinga–Kondepudi resolution of conglomerate amino acid derivatives by slow cooling and abrasive grinding

NARCIS (Netherlands)

Leeman, Michel; Noorduin, Wim L.; Millemaggi, Alessia; Vlieg, Elias; Meekes, Hugo; Enckevort, Willem J.P. van; Kaptein, Bernard; Kellogg, Richard M.

2010-01-01

The complete resolution of the conglomerate racemates of two amino acid derivatives susceptible to racemization in solution was achieved by slow crystallization from a supersaturated solution accompanied by cooling and abrasive grinding.

Numerical modeling of batch formation in waste incineration plants

Directory of Open Access Journals (Sweden)

Obroučka Karel

2015-03-01

Full Text Available The aim of this paper is a mathematical description of algorithm for controlled assembly of incinerated batch of waste. The basis for formation of batch is selected parameters of incinerated waste as its calorific value or content of pollutants or the combination of both. The numerical model will allow, based on selected criteria, to compile batch of wastes which continuously follows the previous batch, which is a prerequisite for optimized operation of incinerator. The model was prepared as for waste storage in containers, as well as for waste storage in continuously refilled boxes. The mathematical model was developed into the computer program and its functionality was verified either by practical measurements or by numerical simulations. The proposed model can be used in incinerators for hazardous and municipal waste.

The effect of freestream turbulence on film cooling adiabatic effectiveness

International Nuclear Information System (INIS)

Mayhew, James E.; Baughn, James W.; Byerley, Aaron R.

2003-01-01

The film-cooling performance of a flat plate in the presence of low and high freestream turbulence is investigated using liquid crystal thermography. This paper contributes high-resolution color images that clearly show how the freestream turbulence spreads the cooling air around a larger area of the film-cooled surface. Distributions of the adiabatic effectiveness are determined over the film-cooled surface of the flat plate using the hue method and image processing. Three blowing rates are investigated for a model with three straight holes spaced three diameters apart, with density ratio near unity. High freestream turbulence is shown to increase the area-averaged effectiveness at high blowing rates, but decrease it at low blowing rates. At low blowing ratio, freestream turbulence clearly reduces the coverage area of the cooling air due to increased mixing with the main flow. However, at high blowing ratio, when much of the jet has lifted off in the low turbulence case, high freestream turbulence turns its increased mixing into an asset, entraining some of the coolant that penetrates into the main flow and mixing it with the air near the surface

Thermo-mechanical characterization of a thermoplastic composite and prediction of the residual stresses and lamina curvature during cooling

Science.gov (United States)

Péron, Mael; Jacquemin, Frédéric; Casari, Pascal; Orange, Gilles; Bailleul, Jean-Luc; Boyard, Nicolas

2017-10-01

The prediction of process induced stresses during the cooling of thermoplastic composites still represents a challenge for the scientific community. However, a precise determination of these stresses is necessary in order to optimize the process conditions and thus lower the stresses effects on the final part health. A model is presented here, that permits the estimation of residual stresses during cooling. It relies on the nonlinear laminate theory, which has been adapted to arbitrary layup sequences. The developed model takes into account the heat transfers through the thickness of the laminate, together with the crystallization kinetics. The development of the composite mechanical properties during cooling is addressed by an incremental linear elastic constitutive law, which also considers thermal and crystallization strains. In order to feed the aforementioned model, a glass fiber and PA6.6 matrix unidirectional (UD) composite has been characterized. This work finally focuses on the identification of the material and process related parameters that lower the residual stresses level, including the ply sequence, the fiber volume fraction and the cooling rate.

Monitoring a PVC batch process with multivariate statistical process control charts

NARCIS (Netherlands)

Tates, A. A.; Louwerse, D. J.; Smilde, A. K.; Koot, G. L. M.; Berndt, H.

1999-01-01

Multivariate statistical process control charts (MSPC charts) are developed for the industrial batch production process of poly(vinyl chloride) (PVC). With these MSPC charts different types of abnormal batch behavior were detected on-line. With batch contribution plots, the probable causes of these

Apparent temperature versus true temperature of silicon crystals as a function of their thickness using infrared measurements

International Nuclear Information System (INIS)

Smither, R.K.; Fernandez, P.B.

1993-01-01

The very high intensity x-ray beams that will be present at the Advanced Photon Source and other third generation synchrotron sources will require that the first optical element in the beamline and, possibly, the second optical element as well, be cooled to remove the heat deposited by the x-ray beam. In many of the beamlines this heat will be in the 1 to 5 kW range, and any failure of the cooling system will require a quick response from safety control circuits to shut off the beam before damage is done to the optical element. In many cases, this first optical element will be a silicon diffraction crystal. Viewing the surface of objects subjected to high heat fluxes with an infrared camera or infrared sensor has proved to be a very effective method for monitoring the magnitude and distribution of surface temperatures on the object. This approach has been quite useful in studies of cooling silicon crystals in monochromators subject to high heat loads. The main drawback to this method is that single crystals of silicon are partially transparent to the infrared radiation monitored in most infrared cameras. This means that the infrared radiation emitted from the surface contains a component that comes from the interior of the crystal and that the intensity of the emitted radiation and thus the apparent temperature of the surface of the crystal depends on the thickness of the crystal and the kind of coating on the back (and/or the front) of the crystal. The apparent temperature of the crystal increases as the crystal is made thicker. A series of experiments were performed at Argonne National Laboratory to calibrate the apparent surface temperature of the crystal as measured with an infrared camera as a function of the crystal thickness and the type of coating (if any) on the back side of the crystal. A number of examples are given for data taken in synchrotron experiments with high intensity x-ray beams

Erythritol: crystal growth from the melt.

Science.gov (United States)

Lopes Jesus, A J; Nunes, Sandra C C; Ramos Silva, M; Matos Beja, A; Redinha, J S

2010-03-30

The structural changes occurring on erythritol as it is cooled from the melt to low temperature, and then heated up to the melting point have been investigated by differential scanning calorimetry (DSC), polarized light thermal microscopy (PLTM), X-ray powder diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR). By DSC, it was possible to set up the conditions to obtain an amorphous solid, a crystalline solid, or a mixture of both materials in different proportions. Two crystalline forms have been identified: a stable and a metastable one with melting points of 117 and 104 degrees C, respectively. The fusion curve decomposition of the stable form revealed the existence of three conformational structures. The main paths of the crystallization from the melt were followed by PLTM. The texture and colour changes allowed the characterization of the different phases and transitions in which they are involved on cooling as well as on heating processes. The type of crystallization front and its velocity were also followed by microscopic observation. These observations, together with the data provided by PXRD, allowed elucidating the transition of the metastable form into the stable one. The structural changes occurring upon the cooling and subsequent heating processes, namely those arising from intermolecular hydrogen bonds, were also accompanied by infrared spectroscopy. Particular attention was given to the spectral changes occurring in the OH stretching region. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Theory of Vortex Crystal Formation in Two-Dimensional Turbulence

Science.gov (United States)

Jin, D. Z.

1999-11-01

The free relaxation of inviscid, incompressible 2D turbulence is often dominated by strong vortices (coherent patches of intense vorticity) that move chaotically and merge. However, recent experiments(K.S. Fine et al., Phys. Rev. Lett. 75), 3277 (1995). with pure electron plasmas have found that freely relaxing turbulent flows with a single sign of vorticity can spontaneously form ``vortex crystals'' -- symmetric, stable arrays of strong vortices that are immersed in a low vorticity background. In this talk we discuss how these complex equilibria can form from 2D turbulence. First, we formulate a statistical theory of the vortex crystals. We show that vortex crystals are well described as ``regional'' maximum fluid entropy (RMFE) states, which are equilibrium states reached through ergodic mixing of the background by the strong vortices.(D.Z. Jin and D.H.E. Dubin, Phys. Rev. Lett. 80), 4434 (1998). Given the dynamically conserved quantities as well as the number and the vorticity distributions of the strong vortices, the theory predicts the positions of the strong vortices and the coarse-grained vorticity distribution of the background. These predictions agree well with the observed vortex crystals. Second, we examine the formation process of the vortex crystals in more detail. In the RMFE theory, the vortex crystal equilibrium can only be predicted if the number Nc of the strong vortices in the final state is given. Here, we estimate Nc from the characteristics of the early turbulent flow. The estimate relies on the idea that vortex crystals form because the chaotic motions of the strong vortices are ``cooled'' due to mixing of the background by the vortices. When the rate of cooling is faster than the rate of pairwise mergers, the vortices fall into a crystal pattern before they can merge. We estimate the merger rate from the observed power law decay of the number of strong vortices in the early stages of the flow, and the cooling rate from the rate of mixing of

Pressure and cooling rate effect on polyhedron clusters in Cu-Al alloy by using molecular dynamics simulation

Science.gov (United States)

Celik, Fatih Ahmet

2014-10-01

In this study, the microstructural evolution of crystal-type and icosahedral (icos)-type polyhedrons in Cu-50 at%Al alloy based on the embedded atom method (EAM) model is studied at two cooling rates under normal and high pressures by using the molecular dynamics (MD) simulation method. The cluster-type index method (CTIM) which describes icos and defective icos polyhedrons and the new cluster-type index method (CTIM-2) which describes crystal-type polyhedrons have been used to perform polyhedron analysis in the model alloy system. The results of our simulations demonstrate that the effects of the cooling rate and pressure play an important role in the numbers of polyhedrons and their structures in the system.

Pressure and cooling rate effect on polyhedron clusters in Cu–Al alloy by using molecular dynamics simulation

Energy Technology Data Exchange (ETDEWEB)

Celik, Fatih Ahmet, E-mail: facelik@beu.edu.tr

2014-10-01

In this study, the microstructural evolution of crystal-type and icosahedral (icos)-type polyhedrons in Cu–50 at%Al alloy based on the embedded atom method (EAM) model is studied at two cooling rates under normal and high pressures by using the molecular dynamics (MD) simulation method. The cluster-type index method (CTIM) which describes icos and defective icos polyhedrons and the new cluster-type index method (CTIM-2) which describes crystal-type polyhedrons have been used to perform polyhedron analysis in the model alloy system. The results of our simulations demonstrate that the effects of the cooling rate and pressure play an important role in the numbers of polyhedrons and their structures in the system.

Spherical Nb single crystals containerlessly grown by electrostatic levitation

International Nuclear Information System (INIS)

Sung, Y.S.; Takeya, H.; Hirata, K.; Togano, K.

2003-01-01

Spherical Nb (T m =2750 K) single crystals were grown via containerless electrostatic levitation (ESL). Samples became spherical at melting in levitation and undercooled typically 300-450 K prior to nucleation. As-processed samples were still spherical without any macroscopic shape change by solidification showing a uniform dendritic surface morphology. Crystallographic {111} planes exposed in equilateral triangular shapes on the surface by preferential macroetching and spotty back-reflection Laue patterns confirm the single crystal nature of the ESL-processed Nb samples. No hysteresis in magnetization between zero field and field cooling also implies a clean defect-free condition of the spherical Nb single crystals

Iron single crystal growth from a lithium-rich melt

Science.gov (United States)

Fix, M.; Schumann, H.; Jantz, S. G.; Breitner, F. A.; Leineweber, A.; Jesche, A.

2018-03-01

α -Fe single crystals of rhombic dodecahedral habit were grown from a Li84N12Fe∼3 melt. Crystals of several millimeter along a side form at temperatures around T ≈ 800 ° C. Upon further cooling the growth competes with the formation of Fe-doped Li3N. The b.c.c. structure and good sample quality of α -Fe single crystals were confirmed by X-ray and electron diffraction as well as magnetization measurements and chemical analysis. A nitrogen concentration of 90 ppm was detected by means of carrier gas hot extraction. Scanning electron microscopy did not reveal any sign of iron nitride precipitates.

Blanket Cooling Plates Mock-ups Manufactured in different Diffusion Weld Setup

International Nuclear Information System (INIS)

Von Der Weth, A.; Aktaa, J.

2007-01-01

Full text of publication follows: The breeding blanket box is considered as one of the most important components of a future fusion power plant. It will be assembled by so called cooling plates (CP) with a system of internal cooling channels. Such a CP is produced by two symmetric half pieces with half milled-in channels. Both pieces will be joined by a diffusion weld (DW) process. Within recent years a two step DW process for different EUROFER batches has been developed. It has been first applied to small laboratory scaled samples with dimensions of 25 mm x 30 mm x 40 mm. Then the DW process had then been successfully transferred to so called compact mock ups which are small CPs with dimensions of 67 mm x 70 mm x 50 mm. As third step this process has been used to manufacture a CP (465 mm x 205 mm x 50 mm) of a breeder unit in an industrial uniaxial diffusion weld setup. This paper treats the manufacturing sequence of a cooling plate and a first wall mock up in an industrial hot isostatic pressing (HIP) setup. The firstly laboratory specimens scaled diffusion weld process has been adjusted to different cooling channel dimensions and a different DW setup. The weld quality is investigated by tensile and Charpy impact testing. This allows comparison of the weld quality of mock ups welded in different DW setups. (authors)

Turbine airfoil cooling system with cooling systems using high and low pressure cooling fluids

Science.gov (United States)

Marsh, Jan H.; Messmann, Stephen John; Scribner, Carmen Andrew

2017-10-25

A turbine airfoil cooling system including a low pressure cooling system and a high pressure cooling system for a turbine airfoil of a gas turbine engine is disclosed. In at least one embodiment, the low pressure cooling system may be an ambient air cooling system, and the high pressure cooling system may be a compressor bleed air cooling system. In at least one embodiment, the compressor bleed air cooling system in communication with a high pressure subsystem that may be a snubber cooling system positioned within a snubber. A delivery system including a movable air supply tube may be used to separate the low and high pressure cooling subsystems. The delivery system may enable high pressure cooling air to be passed to the snubber cooling system separate from low pressure cooling fluid supplied by the low pressure cooling system to other portions of the turbine airfoil cooling system.

Look-ahead strategies for controlling batch operations in industry - An overview

NARCIS (Netherlands)

Zee, Durk-Jouke van der; Chick, SE; Sanchez, PJ; Ferrin, D; Morrice, DJ

2003-01-01

Batching jobs in a manufacturing system is a very common policy in most industries. Main reasons for batching are avoidance of set ups and/or facilitation of material handling. Examples of batch-wise production systems are ovens found in aircraft industry and in semiconductor manufacturing. Starting

[Anaerobic hydrolysis of terramycin crystallizing mother solution].

Science.gov (United States)

Ma, W; Wang, J; Liang, C; Qi, R; Yang, M

2001-09-01

The terramycin crystallizing mother solution contained high organics and high nitrogen. There were many kinds of bioinhibition in it but not enough electronic donor. Anaerobic hydrolysis of terramycin crystallizing mother solution was completed with up anarobic sludge bed in order to improve the biodegradability of wastewater and electronic donor in it. The variations of pH, COD, NH4+, and SO4(2-) were monitored. The COD removal was in a narrow range between 10% and 16.4% even when the HRT of the reactor was changed from 1.5 h to 6 h. pH increased because of formation of NH3 and reduction of SO4(2-). Most of SO4(2-) was reduced to S2- when the HRT was longer than 2 h. Batch experiments on hydrolyzed wastewater demonstrated that reaction rates of nitrification and denitrification increased by 90.9% and 45.2%, respectively.

Feasibility of beam crystallization in a cooler storage ring

Directory of Open Access Journals (Sweden)

Yosuke Yuri

2005-11-01

Full Text Available It has been known theoretically that a charged-particle beam circulating in a storage ring exhibits an “ordered” configuration at the space-charge limit. Such an ultimate state of matter is called a crystalline beam whose emittance is ideally equal to zero except for quantum noise. This paper discusses how close one can come to various ordered states by employing currently available accelerator technologies. The dynamic nature of ultracold beams and conditions required for crystallization are briefly reviewed. Molecular dynamics simulations are performed to study the feasibility of this unique phenomenon, considering practical situations in general cooling experiments. It is pointed out that several essential obstacles must be overcome to reach a three-dimensional crystalline state in a storage ring. Doppler laser cooling of ion beams is also numerically simulated to explore the possibility of beam crystallization in an existing machine.

Hp Ge: Purification, crystal growth, and annealing properties

International Nuclear Information System (INIS)

Hall, R.N.

1984-01-01

The prospects for growing HP Ge crystals of increased size and purity are examined. One interesting approach is to grow dislocation-free crystals, which must then be annealed to reduce the concentration of V 2 H traps. The phenomena which occur during annealing are discussed and compared with experiment. Hydrogen, present in atomic form at the growth temperature, forms H 2 molecules during cooling, causing the effective diffusion coefficient to decrease rapidly. Models representing the reactions between H and the V 2 H, A(H, Si), and D(H,O) complexes are presented and analyzed

Kinetic model for quartz and spinel dissolution during melting of high-level-waste glass batch

International Nuclear Information System (INIS)

Pokorny, Richard; Rice, Jarrett A.; Crum, Jarrod V.; Schweiger, Michael J.; Hrma, Pavel

2013-01-01

The dissolution of quartz particles and the growth and dissolution of crystalline phases during the conversion of batch to glass potentially affects both the glass melting process and product quality. Crystals of spinel exiting the cold cap to molten glass below can be troublesome during the vitrification of iron-containing high-level wastes. To estimate the distribution of quartz and spinel fractions within the cold cap, we used kinetic models that relate fractions of these phases to temperature and heating rate. Fitting the model equations to data showed that the heating rate, apart from affecting quartz and spinel behavior directly, also affects them indirectly via concurrent processes, such as the formation and motion of bubbles. Because of these indirect effects, it was necessary to allow one kinetic parameter (the pre-exponential factor) to vary with the heating rate. The resulting kinetic equations are sufficiently simple for the detailed modeling of batch-to-glass conversion as it occurs in glass melters. The estimated fractions and sizes of quartz and spinel particles as they leave the cold cap, determined in this study, will provide the source terms needed for modeling the behavior of these solid particles within the flow of molten glass in the melter

Workshop on cooling of x-ray monochromators on high power beamlines

International Nuclear Information System (INIS)

Matsushita, T.; Ishikawa, T.

1989-03-01

This report is a Workshop on Cooling of X-ray Monochromators on High Power Beamlines held on August 31, 1988 at the Photon Factory during the Third International Conference on Synchrotron Radiation Instrumentation (SRI88). On high power beamlines, especially on insertion device beamlines, heating of crystal monochromators is becoming a serious problem: Researchers observe that the intensity of the X-ray beam on the sample is not proportional to the source intensity because of thermal distortion of the monochromator crystal. This problem will be even more serious on beamlines for the next generation X-ray rings. In the very tight program of the SRI88 conference, only 2 speakers were able to give invited talks closely related to this problem in the session of OPTICAL COMPONENTS FOR HIGH POWER BEAMLINES on Wednesday morning of August 31, 1988. We held this workshop in the afternoon of the same day with the intention of offering further opportunities to exchange information on efforts underway at various laboratories and to discuss ideas how to solve this problem. We also intended that the workshop would be a 'follow-up' to the X-ray optics workshop held at ESRF, Grenoble in September 1987, where the importance of crystal cooling was strongly pointed out. There were 32 participants from 7 countries. 12 people represented their experiences and ideas for reducing thermal distortion of crystal monochromators. Following those presentations, there were discussions on collaborations for solving this important problem. The attendees agreed that exchange of information should be continued by holding such meetings at reasonable intervals. (J.P.N.)

Morphological changes in polyoxymethylene on heating and cooling

Science.gov (United States)

Guruswamy, K.; Surve, N.; Mathew, R.; Bulakh, N.; Ajithkumar, T.; Rajamohanan, P.; Ratnagiri, R.

2010-03-01

We use modulated DSC, SAXS and solid state NMR to characterize melting, lamellar-level structure and nuclear environments respectively during heating of polyoxymethylene. Two model samples are investigated -- a melt crystallized injection molded sample and a sample obtained by dilute solution crystallization. On heating the molded sample, we observe evidence for pre-melting at temperatures significantly lower than the nominal melting point, and show that this correlates with the melting of thin, imperfect lamellae inserted in-between thicker lamellae. When the temperature is increased from room temperature to around 100^oC, the microstructural changes are essentially reversible on cooling to room temperature. However, on heating to temperatures above 135^oC, melting of the thin lamellae results in irreversible reorganization of the semicrystalline microstructure to form thicker lamellae. In contrast to the behavior of the melt crystallized samples, the solution crystals exhibit no change in the lamellar stacking on heating to 150^oC. With increase in temperature, there is amorphization at the basal surfaces of the lamellae, but the thermal motions of the amorphous chain segments remain highly constrained due to their connectivity to the lamellar surface.

Solving a chemical batch scheduling problem by local search

NARCIS (Netherlands)

Brucker, P.; Hurink, Johann L.

1999-01-01

A chemical batch scheduling problem is modelled in two different ways as a discrete optimization problem. Both models are used to solve the batch scheduling problem in a two-phase tabu search procedure. The method is tested on real-world data.

Crystallization of DNA-coated colloids

Science.gov (United States)

Wang, Yu; Wang, Yufeng; Zheng, Xiaolong; Ducrot, Étienne; Yodh, Jeremy S.; Weck, Marcus; Pine, David J.

2015-01-01

DNA-coated colloids hold great promise for self-assembly of programmed heterogeneous microstructures, provided they not only bind when cooled below their melting temperature, but also rearrange so that aggregated particles can anneal into the structure that minimizes the free energy. Unfortunately, DNA-coated colloids generally collide and stick forming kinetically arrested random aggregates when the thickness of the DNA coating is much smaller than the particles. Here we report DNA-coated colloids that can rearrange and anneal, thus enabling the growth of large colloidal crystals from a wide range of micrometre-sized DNA-coated colloids for the first time. The kinetics of aggregation, crystallization and defect formation are followed in real time. The crystallization rate exhibits the familiar maximum for intermediate temperature quenches observed in metallic alloys, but over a temperature range smaller by two orders of magnitude, owing to the highly temperature-sensitive diffusion between aggregated DNA-coated colloids. PMID:26078020

Experimental evaluation of a direct air-cooled lithium bromide-water absorption prototype for solar air conditioning

International Nuclear Information System (INIS)

Gonzalez-Gil, A.; Izquierdo, M.; Marcos, J.D.; Palacios, E.

2011-01-01

A new direct air-cooled single-effect LiBr-H 2 O absorption prototype is described and proposed for use in solar cooling. As distinguishing aspects, it presents: an adiabatic absorber using flat-fan sheets; an air-cooling system that directly refrigerates both the condenser and the absorber and; the possibility of being operated also as a double-effect unit. A solar facility comprising a 48 m 2 field of flat-plate collectors was used to test the single-effect operation mode of the prototype. Results from an experimental campaign carried out in Madrid during summer 2010 are shown and operation parameters corresponding to two typical summer days are detailed. The prototype worked efficiently, with COP values around 0.6. Cooling power varied from 2 kW to 3.8 kW, which represented about 85% of the prototype's nominal capacity. Chilled water temperatures mostly ranged between 14 o C and 16 o C, although the lowest measured value was of 12.8 o C. Condensation and absorption temperatures were under 50 o C and 46 o C, respectively, even with outdoor temperatures of 40 o C. Driving water temperature ranged between 85 o C and 110 o C. As a mean, the system was able to meet 65% of the cooling demand corresponding to a room of 40 m 2 . No signs of crystallization were observed during about a hundred hours of operation. - Highlights: → A novel direct air-cooled single-effect absorption prototype is described. → Feasibility of air-cooled technology for LiBr-H 2 O absorption cooling is proved. → An adiabatic absorber using flat-fan sheets avoids crystallization of the solution. → A field of flat-plate collectors powers the chiller at temperatures from 85 to 110 o C. → The prototype works with thermal COP about 0.6.

Palm-based diacylglycerol fat dry fractionation: effect of crystallisation temperature, cooling rate and agitation speed on physical and chemical properties of fractions

Directory of Open Access Journals (Sweden)

Razam Ab Latip

2013-05-01

Full Text Available Fractionation which separates the olein (liquid and stearin (solid fractions of oil is used to modify the physicochemical properties of fats in order to extend its applications. Studies showed that the properties of fractionated end products can be affected by fractionation processing conditions. In the present study, dry fractionation of palm-based diacylglycerol (PDAG was performed at different: cooling rates (0.05, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0°C/min, end-crystallisation temperatures (30, 35, 40, 45 and 50°C and agitation speeds (30, 50, 70, 90 and 110 rpm to determine the effect of these parameters on the properties and yield of the solid and liquid portions. To determine the physicochemical properties of olein and stearin fraction: Iodine value (IV, fatty acid composition (FAC, acylglycerol composition, slip melting point (SMP, solid fat content (SFC, thermal behaviour tests were carried out. Fractionation of PDAG fat changes the chemical composition of liquid and solid fractions. In terms of FAC, the major fatty acid in olein and stearin fractions were oleic (C18:1 and palmitic (C16:0 respectively. Acylglycerol composition showed that olein and stearin fractions is concentrated with TAG and DAG respectively. Crystallization temperature, cooling rate and agitation speed does not affect the IV, SFC, melting and cooling properties of the stearin fraction. The stearin fraction was only affected by cooling rate which changes its SMP. On the other hand, olein fraction was affected by crystallization temperature and cooling rate but not agitation speed which caused changes in IV, SMP, SFC, melting and crystallization behavior. Increase in both the crystallization temperature and cooling rate caused a reduction of IV, increment of the SFC, SMP, melting and crystallization behaviour of olein fraction and vice versa. The fractionated stearin part melted above 65°C while the olein melted at 40°C. SMP in olein fraction also reduced to a range of

Acceptance Test Data for Candidate AGR-5/6/7 TRISO Particle Batches BWXT Coater Batches 93165 93172 Defective IPyC Fraction and Pyrocarbon Anisotropy

Energy Technology Data Exchange (ETDEWEB)

Helmreich, Grant W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Skitt, Darren J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dyer, John A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Schumacher, Austin T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-03-01

Coated particle fuel batches J52O-16-93165, 93166, 93168, 93169, 93170, and 93172 were produced by Babcock and Wilcox Technologies (BWXT) for possible selection as fuel for the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program’s AGR-5/6/7 irradiation test in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR). Some of these batches may alternately be used as demonstration coated particle fuel for other experiments. Each batch was coated in a 150-mm-diameter production-scale fluidized-bed chemical vapor deposition (CVD) furnace. Tristructural isotropic (TRISO) coatings were deposited on 425-μm-nominal-diameter spherical kernels from BWXT lot J52R-16-69317 containing a mixture of 15.5%-enriched uranium carbide and uranium oxide (UCO). The TRISO coatings consisted of four consecutive CVD layers: a ~50% dense carbon buffer layer with 100-μm-nominal thickness, a dense inner pyrolytic carbon (IPyC) layer with 40-μm-nominal thickness, a silicon carbide (SiC) layer with 35-μm-nominal thickness, and a dense outer pyrolytic carbon (OPyC) layer with 40-μmnominal thickness. The TRISO-coated particle batches were sieved to upgrade the particles by removing over-sized and under-sized material, and the upgraded batches were designated by appending the letter A to the end of the batch number (e.g., 93165A).

PROOF on a Batch System

International Nuclear Information System (INIS)

Behrenhoff, W; Ehrenfeld, W; Samson, J; Stadie, H

2011-01-01

The 'parallel ROOT facility' (PROOF) from the ROOT framework provides a mechanism to distribute the load of interactive and non-interactive ROOT sessions on a set of worker nodes optimising the overall execution time. While PROOF is designed to work on a dedicated PROOF cluster, the benefits of PROOF can also be used on top of another batch scheduling system with the help of temporary per user PROOF clusters. We will present a lightweight tool which starts a temporary PROOF cluster on a SGE based batch cluster or, via a plugin mechanism, e.g. on a set of bare desktops via ssh. Further, we will present the result of benchmarks which compare the data throughput for different data storage back ends available at the German National Analysis Facility (NAF) at DESY.

Comparative study of trapping parameters of LiF(TLD-100) from different production batches

Energy Technology Data Exchange (ETDEWEB)

Bos, A.J.J.; Piters, T.M.; Vries, W. de; Hoogenboom, J.E. (Delft Univ. of Technology (Netherlands). Interfaculty Reactor Institute)

1990-01-01

Computerised glow curve analysis has been used to determine the trapping parameters of the main peaks of the thermoluminescent (TL) material LiF(TLD-100). The TL material (solid state chips) originated from six different production batches with at least 19 chips per batch. The maxima of glow peaks 2 to 5 are found at the same temperature within very small limits. The activation energy and frequency factor of the main glow peak (peak 5) of TLD-100 originating from two batches differ significantly from those of the other four investigated batches. Nevertheless, the sensitivity of glow peak 5 is more or less the same for all batches. The trapping parameters of glow peaks 2 to 4 of TLD-100 vary little from batch to batch. The measured half-life of peak 2 differed strongly from batch to batch. For all investigated peaks no correlation has been found between glow peak sensitivity and trapping parameters. The results of this study suggest that both defect concentration and nature of the trapping centres vary from batch to batch. It would appear that as a consequence of selection by the manufacturer, the differences between the batches in terms of total light output are small. (author).

From Fed-batch to Continuous Enzymatic Biodiesel Production

DEFF Research Database (Denmark)

Price, Jason Anthony; Nordblad, Mathias; Woodley, John M.

2015-01-01

In this this paper, we use mechanistic modelling to guide the development of acontinuous enzymatic process that is performed as a fed-batch operation. In this workwe use the enzymatic biodiesel process as a case study. A mechanistic model developedin our previous work was used to determine...... measured components (triglycerides, diglycerides, monoglycerides, free fatty acid and fatty acid methyl esters(biodiesel)) much better than using fed-batch data alone given the smaller residuals. We also observe a reduction in the correlation between the parameters.The model was then used to predict that 5...... reactors are required (with a combined residence time of 30 hours) to reach a final biodiesel concentration within 2 % of the95.6 mass % achieved in a fed-batch operation, for 24 hours....

Mechanism of Phase Formation in the Batch Mixtures for Slag-Bearing Glass Ceramics - 12207

Energy Technology Data Exchange (ETDEWEB)

Stefanovsky, Sergey V.; Stefanovsky, Olga I.; Malinina, Galina A. [SIA Radon, 7th Rostovskii lane 2/14, Moscow 119121 (Russian Federation)

2012-07-01

Slag surrogate was produced from chemicals by heating to 900 deg. C and keeping at this temperature for 1 hr. The product obtained was intermixed with either sodium di-silicate (75 wt.% waste loading) or borax (85 wt.% slag loading). The mixtures were heat-treated within a temperature range of 25 to 1300 deg. C. The products were examined by X-ray diffraction and infrared spectroscopy. The products prepared at temperatures of up to 1000 deg. C contained both phase typical of the source slag and intermediate phases as well as phases typical of the materials melted at 1350 deg. C such as nepheline, britholite, magnetite and matrix vitreous phase. Vitrification process in batch mixtures consisting of slag surrogate and either sodium di-silicate or sodium tetraborate runs through formation of intermediate phases mainly silico-phosphates capable to incorporate Sm as trivalent actinides surrogate. Reactions in the batch mixtures are in the whole completed by ∼1000 deg. C but higher temperatures are required to homogenize the products. If in the borate-based system the mechanism is close to simple dissolution of slag constituents in the low viscous borate melt, then in the silicate-based system the mechanism was found to be much complicated and includes re-crystallization during melting with segregation of newly-formed nepheline type phase. (authors)

Crystallization of Polymers Investigated by Temperature-Modulated DSC

Directory of Open Access Journals (Sweden)

Maria Cristina Righetti

2017-04-01

Full Text Available The aim of this review is to summarize studies conducted by temperature-modulated differential scanning calorimetry (TMDSC on polymer crystallization. This technique can provide several advantages for the analysis of polymers with respect to conventional differential scanning calorimetry. Crystallizations conducted by TMDSC in different experimental conditions are analysed and discussed, in order to illustrate the type of information that can be deduced. Isothermal and non-isothermal crystallizations upon heating and cooling are examined separately, together with the relevant mathematical treatments that allow the evolution of the crystalline, mobile amorphous and rigid amorphous fractions to be determined. The phenomena of ‘reversing’ and ‘reversible‘ melting are explicated through the analysis of the thermal response of various semi-crystalline polymers to temperature modulation.

Inorganic fouling mitigation by salinity cycling in batch reverse osmosis

OpenAIRE

Maswadeh, Laith A.; Warsinger, David Elan Martin; Tow, Emily W.; Connors, Grace B.; Swaminathan, Jaichander; Lienhard, John H

2018-01-01

Enhanced fouling resistance has been observed in recent variants of reverse osmosis (RO) desalination which use time-varying batch or semi-batch processes, such as closed-circuit RO (CCRO) and pulse flow RO (PFRO). However, the mechanisms of batch processes' fouling resistance are not well-understood, and models have not been developed for prediction of their fouling performance. Here, a framework for predicting reverse osmosis fouling is developed by comparing the fluid residence time in bat...

Dynamic Scheduling Of Batch Operations With Non-Identical Machines

NARCIS (Netherlands)

van der Zee, D.J.; van Harten, A.; Schuur, P.C.

1997-01-01

Batch-wise production is found in many industries. A good example of production systems which process products batch-wise are the ovens found in aircraft industry and in semiconductor manufacturing. These systems mostly consist of multiple machines of different types, given the range and volumes of

Dynamic scheduling of batch operations with non-identical machines

NARCIS (Netherlands)

van der Zee, D.J.; van Harten, Aart; Schuur, Peter

1997-01-01

Batch-wise production is found in many industries. A good example of production systems which process products batch-wise are the ovens found in aircraft industry and in semiconductor manufacturing. These systems mostly consist of multiple machines of different types, given the range and volumes of

Some performance measures for vacation models with a batch Markovian arrival process

Directory of Open Access Journals (Sweden)

Sadrac K. Matendo

1994-01-01

Full Text Available We consider a single server infinite capacity queueing system, where the arrival process is a batch Markovian arrival process (BMAP. Particular BMAPs are the batch Poisson arrival process, the Markovian arrival process (MAP, many batch arrival processes with correlated interarrival times and batch sizes, and superpositions of these processes. We note that the MAP includes phase-type (PH renewal processes and non-renewal processes such as the Markov modulated Poisson process (MMPP.

Calorimetric studies of non-isothermal crystallization in amorphous

Indian Academy of Sciences (India)

Administrator

the peak crystallization temperature. Amorphous alloys of Cu–Ti system are of special interest (Koster et al 1995) due to the fact that Cu–Ti is a congruently melting compound, which should allow static under-cooling experiments. Several works ... tion when mixed with another metal or rare earth metals. (Suzuki et al 2003).

Effects of high pressure on microstructure evolution and crystallization mechanisms during solidification of nickel

Science.gov (United States)

Zhang, Hai-Tao; Mo, Yun-Fei; Liu, Rang-Su; Tian, Ze-An; Liu, Hai-Rong; Hou, Zhao-Yang; Zhou, Li-Li; Liang, Yong-Chao; Peng, Ping

2018-03-01

To deeply understand the effects of high pressure on microstructural evolutions and crystallization mechanisms of liquid metal Ni during solidification process, MD simulation studies have been performed under 7 pressures of 0 ˜ 30 GPa, at cooling rate of 1.0 × 1011 K s-1. Adopting several microstructural analyzing methods, especially the cluster-type index method (CTIM-2) to analyze the local microstructures in the system. It is found that the pressure has important influence on the formation and evolution of microstructures, especially of the main basic clusters in the system. All the simulation systems are directly solidified into crystal structures, and the 1421, 1422, 1441 and 1661 bond-types, as well the FCC (12 0 0 0 12 0), HCP (12 0 0 0 6 6) and BCC (14 6 0 8 0 0) clusters play a key role in the microstructure transitions from liquid to crystal structures. The crystallization temperature T c is enhanced almost linearly with the increase of pressure. Highly interesting, it is found for the first time that there is an important phase transformation point from FCC to BCC structures between 20 ˜ 22.5 GPa during the solidification processes from the same initial liquid system at the same cooling rate. And the effect of increasing pressure is similar to that of decreasing cooling rate for the phase transformation of microstructures during solidification process of liquid metal Ni system, though they have different concrete effecting mechanisms.

21 CFR 80.37 - Treatment of batch pending certification.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Treatment of batch pending certification. 80.37 Section 80.37 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL COLOR ADDITIVE CERTIFICATION Certification Procedures § 80.37 Treatment of batch pending certification...

New Estimation of the Dosage of Scale Inhibitor in the Cooling Water System

Directory of Open Access Journals (Sweden)

Jiang Jiaomei

2011-01-01

Full Text Available In the cooling water system, excessive use of organic phosphate scale inhibitors is harmful to environment. Reducing the dosage of the organic phosphate scale inhibitor is important. A self-made jacketed crystallizer was used in this experiment. The critical pH values have been determined in cooling water systems with series of Ca2+ concentrations by adding different concentration of the scale inhibitor ATMP (Amino Trimethylene Phosphonic Acid according to the calcium carbonate Metastable zone theory. A model equation at 45 °C and pH=9 was proposed to estimate the lowest dose of the scale inhibitor ATMP. The measured pH value was approximate to the expected pH value in two cooling water systems through verification test.

Influence of coal batch preparation on the quality of metallurgical соkе

Directory of Open Access Journals (Sweden)

Катерина Олегівна Шмельцер

2015-10-01

Full Text Available To study the influence of coal batch properties on coke strength we have considered the quality of the coke produced at the plant in Krivoy Rog from 2008 till 2012. Such factors as the large number of coal suppliers, imprecise selection of the optimal degree of batch crushing result in the decline in coke quality, the batch density and contents of the lean class (<0,5 mm are not optimum; poor blending of the batch after crushing; increased moisture and ash content of the coking batch; and extreme fluctuation in the coal and batch characteristics. It was found that high humidity of coal batch and its large fluctuations has most profound effect on the mechanical properties of coke. Under deteriorating resource base the quality of the coking batch preparation is important, To have batch of proper quality the following key aspects must be taken into account: the batch must be crushed to an optimum degree that will result in leaning components decrease and increased contents of vitrivite in it which improves the sinterability and coking, and hence the quality of coke; the degree of mixing of the coking batch in all indices must be up to 98-99%, for uneven distribution in the coal chamber worsens the quality of coke

Beyond Batch Processing: Towards Real-Time and Streaming Big Data

OpenAIRE

Shahrivari, Saeed; Jalili, Saeed

2014-01-01

Today, big data is generated from many sources and there is a huge demand for storing, managing, processing, and querying on big data. The MapReduce model and its counterpart open source implementation Hadoop, has proven itself as the de facto solution to big data processing. Hadoop is inherently designed for batch and high throughput processing jobs. Although Hadoop is very suitable for batch jobs but there is an increasing demand for non-batch processes on big data like: interactive jobs, r...

Cooling crystallization of Indomethacin from different organic solvents

DEFF Research Database (Denmark)

Malwade, Chandrakant Ramkrishna; Qu, Haiyan

, 25, 35, and 45 °C. The solvents with varying polarities (ethanol, methanol, ethyl acetate, acetone, acetonitrile, and dichloromethane) were used for solubility measurement. Maximum solubility of IMC was observed in acetone, while acetonitrile showed the lowest solubility. Solid phase analysis...... of excess solute with XRPD and Raman spectroscopy confirmed formation of IMC solvate in acetone, methanol and dichloromethane at 15 °C. Based on solubility of IMC, the solvents ethanol, ethyl acetate, acetone, and dichloromethane were selected for crystallization experiments. Nucleation kinetics of IMC...... in selected solvents was investigated through the measurement of induction time at 5 °C and 15 °C. Longer induction times were observed for IMC in ethanol at both temperatures compared to the one in acetone. Metastable α form of IMC was obtained from ethanol, while solvate of IMC was produced from acetone....

Physical changes of beta-sitosterol crystals in oily suspensions during heating

DEFF Research Database (Denmark)

von Bonsdorff-Nikander, Anna; Lievonen, Satu; Christiansen, Leena

2005-01-01

with the mechanical properties of the suspensions during heating were studied by using variable temperature X-ray powder diffractometry (VT-XRPD), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). Hydrated beta-sitosterol crystals in an oil-suspension dehydrated, despite the composition...... of the suspensions, at low temperatures. At high beta-sitosterol concentration, the monohydrate crystal form changed partially to a hemihydrated form, and when only a small amount of water was initially incorporated, the hemihydrate crystal form dehydrated to a mostly anhydrate crystal form. The released water......, which was immiscible in the surrounding oil, caused the recrystallization of hydrated beta-sitosterol during cooling. This procedure indicated a reversible dehydration process. Structural and thermal analysis of beta-sitosterol crystals in suspensions, together with mechanical analysis made it possible...

Neutron production with a pyroelectric double-crystal assembly without nano-tip

International Nuclear Information System (INIS)

Tornow, W.; Corse, W.; Crimi, S.; Fox, J.

2010-01-01

Two cylindrical LiTaO 3 crystals facing each other's deuterated circular face were exposed to deuterium gas at an ambient pressure of a few mTorr. With a distance of about 4 cm between the z + and z - cut crystal faces, neutrons were produced via the 2 H(d,n) 3 He fusion reaction upon the heating and cooling of the crystals. The 2.5 MeV neutrons were detected with organic liquid scintillation detectors equipped with neutron-gamma pulse-shape discrimination electronics to reject pulses generated by the intense X-ray flux. During the cooling phase of naked crystals, deuterium ion-beam (D 2 + ) energies of up to 400 keV were obtained as deduced from the associated electron bremsstrahlung end-point energy. The highest electron-beam energy observed during the heating phase was 360 keV. With a layer of deuterated polyethylene evaporated on the front face of the crystals, the maximal energies were about 10% lower. In contrast to earlier studies, an electric-field enhancing nano-tip was not employed. Neutron yields up to 500 per thermal cycle were observed, resulting in a total neutron production yield of about 1.6x10 4 neutrons per thermal cycle. Our approach has the potential of being substantially improved by reducing the frequency of the discharges we are currently experiencing with our geometry, which was not designed for the unprecedented high potentials produced in the presentwork.

Unique Reversible Crystal-to-Crystal Phase Transition – Structural and Functional Properties of Fused Ladder Thienoarenes

KAUST Repository

Abe, Yuichiro

2017-08-15

Donor-acceptor type molecules based on fused ladder thienoarenes, indacenodithiophene (IDT) and dithienocyclopenta-thienothiophene (DTCTT), coupled with benzothiadiazole, are prepared and their solid-state structures are investigated. They display a rich variety of solid phases ranging from amorphous glass states to crystalline states, upon changes in the central aromatic core and side group structures. Most notably, the DTCTT-based derivatives showed reversible crystal-to-crystal phase transitions in heating and cooling cycles. Unlike what has been seen in π−conjugated molecules variable temperature XRD revealed that structural change occurs continuously during the transition. A columnar self-assembled structure with slip-stacked π−π interaction is proposed to be involved in the solid-state. This research provides the evidence of unique structural behavior of the DTCTT-based molecules through the detailed structural analysis. This unique structural transition paves the way for these materials to have self-healing of crystal defects, leading to improved optoelectronic properties.

Unique Reversible Crystal-to-Crystal Phase Transition – Structural and Functional Properties of Fused Ladder Thienoarenes

KAUST Repository

Abe, Yuichiro; Savikhin, Victoria; Yin, Jun; Grimsdale, Andrew C.; Soci, Cesare; Toney, Michael F.; Lam, Yeng Ming

2017-01-01

Donor-acceptor type molecules based on fused ladder thienoarenes, indacenodithiophene (IDT) and dithienocyclopenta-thienothiophene (DTCTT), coupled with benzothiadiazole, are prepared and their solid-state structures are investigated. They display a rich variety of solid phases ranging from amorphous glass states to crystalline states, upon changes in the central aromatic core and side group structures. Most notably, the DTCTT-based derivatives showed reversible crystal-to-crystal phase transitions in heating and cooling cycles. Unlike what has been seen in π−conjugated molecules variable temperature XRD revealed that structural change occurs continuously during the transition. A columnar self-assembled structure with slip-stacked π−π interaction is proposed to be involved in the solid-state. This research provides the evidence of unique structural behavior of the DTCTT-based molecules through the detailed structural analysis. This unique structural transition paves the way for these materials to have self-healing of crystal defects, leading to improved optoelectronic properties.

Expression, purification, crystallization and preliminary X-ray diffraction analysis of Arabidopsis thaliana cyclophilin 38 (AtCyp38)

International Nuclear Information System (INIS)

Vasudevan, Dileep; Gopalan, Gayathri; He, Zengyong; Luan, Sheng; Swaminathan, Kunchithapadam

2005-01-01

Crystallization of Arabidopsis thaliana cyclophilin 38. The crystal diffracts X-rays to 2.5 Å resolution. AtCyp38 is one of the highly divergent multidomain cyclophilins from Arabidopsis thaliana. A recombinant form of AtCyp38 (residues 83–437) was expressed in Escherichia coli and purified to homogeneity. The protein was crystallized using the vapour-batch technique with PEG 6000 and t-butanol as precipitants. Crystals of recombinant AtCyp38 diffracted X-rays to better than 2.5 Å resolution at 95 K using a synchrotron-radiation source. The crystal belongs to the C-centred orthorhombic space group C222 1 , with unit-cell parameters a = 58.2, b = 95.9, c = 167.5 Å, and contains one molecule in the asymmetric unit. The selenomethionine derivative of the AtCyp38 protein was overexpressed, purified and crystallized in the same space group and data were collected to 3.5 Å at the NSLS synchrotron. The structure is being solved by the MAD method

Following an Optimal Batch Bioreactor Operations Model

DEFF Research Database (Denmark)

Ibarra-Junquera, V.; Jørgensen, Sten Bay; Virgen-Ortíz, J.J.

2012-01-01

The problem of following an optimal batch operation model for a bioreactor in the presence of uncertainties is studied. The optimal batch bioreactor operation model (OBBOM) refers to the bioreactor trajectory for nominal cultivation to be optimal. A multiple-variable dynamic optimization of fed...... as the master system which includes the optimal cultivation trajectory for the feed flow rate and the substrate concentration. The “real” bioreactor, the one with unknown dynamics and perturbations, is considered as the slave system. Finally, the controller is designed such that the real bioreactor...

Initial crystallization and growth in melt processing of large-domain YBa2Cu3Ox for magnetic levitation

International Nuclear Information System (INIS)

Shi, D.

1994-10-01

Crystallization temperature in YBa 2 Cu 3 O x (123) during peritectic reaction has been studied by differential thermal analysis (DTA) and optical microscopy. It has been found that YBa 2 Cu 3 O x experiences partial melting near 1,010 C during heating while crystallization takes place at a much lower temperature range upon cooling indicating a delayed nucleation process. A series of experiments have been conducted to search for the initial crystallization temperature in the Y 2 BaCuO x + liquid phase field. The authors have found that the slow-cool period (1 C/h) for the 123 grain texturing can start at as low as 960 C. This novel processing has resulted in high-quality, large-domain, strongly pinned 123 magnetic levitators

Limiting factors in Escherichia colifed-batch production of recombinant proteins

DEFF Research Database (Denmark)

Sanden, A.M.; Prytz, I.; Tubelekas, I.

2003-01-01

recombinant protein production, fed-batch, specific growth rate, feed profile, induction, mRNA, transcription, translation, acetic acid formation......recombinant protein production, fed-batch, specific growth rate, feed profile, induction, mRNA, transcription, translation, acetic acid formation...

Growth of large PbTiO[sub 3] crystals by a self-flux technique

Energy Technology Data Exchange (ETDEWEB)

Sun, B.N. (Dept. of Materials Science and Engineering, Materials Research Lab., and Beckman Inst., Univ. of Illinois, Urbana-Champaign (United States)); Huang, Y. (Dept. of Materials Science and Engineering, Materials Research Lab., and Beckman Inst., Univ. of Illinois, Urbana-Champaign (United States)); Payne, D.A. (Dept. of Materials Science and Engineering, Materials Research Lab., and Beckman Inst., Univ. of Illinois, Urbana-Champaign (United States))

1993-03-01

Pure lead titanate (PbTiO[sub 3]) crystals (5x5x5 mm[sup 3]) were grown from high-temperature solutions by a slow cooling technique using PbO as a self-flux. The optimum growth conditions were determined to be: (1) (1-x) TiO[sub 2]+x PbO with x (in mol%) varying from 0.78 to 0.82 for the starting compositions, (2) 930-1050 C as the growth temperature range and (3) 0.4-1.5 C/h as the cooling rates. Evaporation of PbO was significantly reduced by use of a double-crucible technique. The grown crystals were characterized by X-ray diffraction, chemical analysis and optical microscopy. The transformation temperatures (onset) of 492.5 C (on heating) and 491.3 C (on cooling) were determined by differential scanning calorimetry. The transformation process had a thermal hysteresis of 1.2 C from onset data. (orig.)

Measurement of Total Condensation on a Shrouded Cryogenic Surface using a Single Quart Crystal Microbalance

International Nuclear Information System (INIS)

Haid, B.J.; Malsbury, T.N.; Gibson, C.R.; Warren, C.T.

2008-01-01

A single quartz crystal microbalance (QCM) is cooled to 18 K to measure condensation rates inside of a retractable ''shroud'' enclosure. The shroud is of a design intended to minimize condensate on fusion targets to be fielded at the National Ignition Facility (NIF). The shroud has a double-wall construction with an inner wall that may be cooled to 75-100 K. The QCM and the shroud system were mounted in a vacuum chamber and cooled using a cryocooler. Condensation rates were measured at various vacuum levels and compositions, and with the shroud open or closed. A technique for measuring total condensate during the cooldown of the system with an accuracy of better than 1.0 x 10 -6 g/cm 2 was also demonstrated. The technique involved a separate measurement of the condensate-free crystal frequency as a function of temperature that was later applied to the measurement of interest

Modelling and Simulation of the Batch Hydrolysis of Acetic ...

African Journals Online (AJOL)

The kinetic modelling of the batch synthesis of acetic acid from acetic anhydride was investigated. The kinetic data of the reaction was obtained by conducting the hydrolysis reaction in a batch reactor. A dynamic model was formulated for this process and simulation was carried out using gPROMS® an advanced process ...

40 CFR 63.1326 - Batch process vents-recordkeeping provisions.

Science.gov (United States)

2010-07-01

....1325(e) for aggregate batch vent streams; (ii) For a boiler or process heater, a description of the location at which the vent stream is introduced into the boiler or process heater; (iii) For a boiler or... process vents or halogenated aggregate batch vent streams, the percent reduction of total hydrogen halides...

Simulation of kefiran production of Lactobacillus kefiranofaciens JCM6985 in fed-batch reactor

Directory of Open Access Journals (Sweden)

Benjamas Cheirsilp

2006-09-01

Full Text Available Kinetics of kefiran production by Lactobacillus kefiranofaciens JCM6985 has been investigated. A mathematical model taking into account the mechanism of exopolysaccharides production has been developed. Experiments were carried out in batch mode in order to obtain kinetic model parameters that were further applied to simulate fed-batch processes. A simplification of parameter fitting was also introduced for complicated model. The fed-batch mode allows more flexibility in the control of the substrate concentration as well as product concentration in the culture medium. Based on the batch mathematical model, a fed-batch model was developed and simulations were done. Simulation study in fed-batch reactor resulted that substrate concentration should be controlled at 20 g L-1 to soften the product inhibition and also to stimulate utilization of substrate and its hydrolysate. From simulation results of different feeding techniques, it was found that constant feeding at 0.01 L h-1 was most practically effective feeding profile for exopolysaccharides production in fed-batch mode.

Proceedings: Cooling tower and advanced cooling systems conference

International Nuclear Information System (INIS)

1995-02-01

This Cooling Tower and Advanced Cooling Systems Conference was held August 30 through September 1, 1994, in St. Petersburg, Florida. The conference was sponsored by the Electric Power Research Institute (EPRI) and hosted by Florida Power Corporation to bring together utility representatives, manufacturers, researchers, and consultants. Nineteen technical papers were presented in four sessions. These sessions were devoted to the following topics: cooling tower upgrades and retrofits, cooling tower performance, cooling tower fouling, and dry and hybrid systems. On the final day, panel discussions addressed current issues in cooling tower operation and maintenance as well as research and technology needs for power plant cooling. More than 100 people attended the conference. This report contains the technical papers presented at the conference. Of the 19 papers, five concern cooling tower upgrades and retrofits, five to cooling tower performance, four discuss cooling tower fouling, and five describe dry and hybrid cooling systems. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

40 CFR 63.487 - Batch front-end process vents-reference control technology.

Science.gov (United States)

2010-07-01

... § 63.487 Batch front-end process vents—reference control technology. (a) Batch front-end process vents... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch front-end process vents-reference control technology. 63.487 Section 63.487 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

Barium iodide and strontium iodide crystals andd scintillators implementing the same

Science.gov (United States)

Payne, Stephen A; Cherepy, Nerine J; Hull, Giulia E; Drobshoff, Alexander D; Burger, Arnold

2013-11-12

In one embodiment, a material comprises a crystal comprising strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector according to another embodiment includes a scintillator optic comprising europium-doped strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector in yet another embodiment includes a scintillator optic comprising SrI.sub.2 and BaI.sub.2, wherein a ratio of SrI.sub.2 to BaI.sub.2 is in a range of between 0:1 A method for manufacturing a crystal suitable for use in a scintillator includes mixing strontium iodide-containing crystals with a source of Eu.sup.2+, heating the mixture above a melting point of the strontium iodide-containing crystals, and cooling the heated mixture near the seed crystal for growing a crystal. Additional materials, systems, and methods are presented.

Meeting report: batch-to-batch variability in estrogenic activity in commercial animal diets--importance and approaches for laboratory animal research.

Science.gov (United States)

Heindel, Jerrold J; vom Saal, Frederick S

2008-03-01

We report information from two workshops sponsored by the National Institutes of Health that were held to a) assess whether dietary estrogens could significantly impact end points in experimental animals, and b) involve program participants and feed manufacturers to address the problems associated with measuring and eliminating batch-to-batch variability in rodent diets that may lead to conflicting findings in animal experiments within and between laboratories. Data were presented at the workshops showing that there is significant batch-to-batch variability in estrogenic content of commercial animal diets, and that this variability results in differences in experimental outcomes. A combination of methods were proposed to determine levels of total estrogenic activity and levels of specific estrogenic constituents in soy-containing, casein-containing, and other soy-free rodent diets. Workshop participants recommended that researchers pay greater attention to the type of diet being used in animal studies and choose a diet whose estrogenic activity (or lack thereof) is appropriate for the experimental model and end points of interest. Information about levels of specific phytoestrogens, as well as estrogenic activity caused by other contaminants and measured by bioassay, should be disclosed in scientific publications. This will require laboratory animal diet manufacturers to provide investigators with information regarding the phytoestrogen content and other estrogenic compounds in commercial diets used in animal research.

The influence of brazing materials on the strain formation of intenally water-cooled x-ray optics

Czech Academy of Sciences Publication Activity Database

Oberta, Peter; Kittler, Martin; Áč, V.; Hrdý, Jaromír; Iragashi, N.; Scheinost, A.C.; Uchida, Y.

2015-01-01

Roč. 22, Mar (2015), 342-347 ISSN 0909-0495 Institutional support: RVO:68378271 Keywords : X-ray optics * high heat load * internal cooling * crystal bonding Subject RIV: BH - Optics , Masers, Lasers Impact factor: 2.736, year: 2014

Dependence of the residual surface resistance of superconducting radio frequency cavities on the cooling dynamics around Tc

Science.gov (United States)

Romanenko, A.; Grassellino, A.; Melnychuk, O.; Sergatskov, D. A.

2014-05-01

We report a strong effect of the cooling dynamics through Tc on the amount of trapped external magnetic flux in superconducting niobium cavities. The effect is similar for fine grain and single crystal niobium and all surface treatments including electropolishing with and without 120 °C baking and nitrogen doping. Direct magnetic field measurements on the cavity walls show that the effect stems from changes in the flux trapping efficiency: slow cooling leads to almost complete flux trapping and higher residual resistance, while fast cooling leads to the much more efficient flux expulsion and lower residual resistance.

Dynamic Extensions of Batch Systems with Cloud Resources

International Nuclear Information System (INIS)

Hauth, T; Quast, G; Büge, V; Scheurer, A; Kunze, M; Baun, C

2011-01-01

Compute clusters use Portable Batch Systems (PBS) to distribute workload among individual cluster machines. To extend standard batch systems to Cloud infrastructures, a new service monitors the number of queued jobs and keeps track of the price of available resources. This meta-scheduler dynamically adapts the number of Cloud worker nodes according to the requirement profile. Two different worker node topologies are presented and tested on the Amazon EC2 Cloud service.

Crystallization features of ternary reversible reciprocal systems

International Nuclear Information System (INIS)

Tomashik, V.N.; Shcherbak, L.P.; Fejchuk, P.I.; Grytsiv, V.I.

2006-01-01

Some features of the primary crystallization of phases in ternary reversible reciprocal system are considered and discussed. The diagonal join CdTe-GeSe of the CdTe + GeSe = CdSe + GeTe ternary reciprocal system is studied to show that the features in primary and secondary heating and cooling curves in such systems under fully equilibrium conditions are not reproduced upon consecutive heating and cooling sessions, because of the existence of different amounts of the reagents and the reaction products in the mixture; the temperatures of each transformation lie in a range. Those who experimentally investigate other ternary and more complex reversible reciprocal systems should take this fact into account [ru

Tier 3 batch system data locality via managed caches

Science.gov (United States)

Fischer, Max; Giffels, Manuel; Jung, Christopher; Kühn, Eileen; Quast, Günter

2015-05-01

Modern data processing increasingly relies on data locality for performance and scalability, whereas the common HEP approaches aim for uniform resource pools with minimal locality, recently even across site boundaries. To combine advantages of both, the High- Performance Data Analysis (HPDA) Tier 3 concept opportunistically establishes data locality via coordinated caches. In accordance with HEP Tier 3 activities, the design incorporates two major assumptions: First, only a fraction of data is accessed regularly and thus the deciding factor for overall throughput. Second, data access may fallback to non-local, making permanent local data availability an inefficient resource usage strategy. Based on this, the HPDA design generically extends available storage hierarchies into the batch system. Using the batch system itself for scheduling file locality, an array of independent caches on the worker nodes is dynamically populated with high-profile data. Cache state information is exposed to the batch system both for managing caches and scheduling jobs. As a result, users directly work with a regular, adequately sized storage system. However, their automated batch processes are presented with local replications of data whenever possible.

Effect of hole imperfection on adiabatic film cooling effectiveness

International Nuclear Information System (INIS)

Jovanovic, M.B.; Lange, H.C.; Steenhoven, A.A. van

2008-01-01

The influence of a discrete imperfection on film cooling is studied by means of thermochromic liquid crystals measurements of the adiabatic film cooling effectiveness. As a benchmark, the effect of a jet ejected through a perfect hole is used. The film cooling effectiveness achieved with an imperfect hole is compared to the benchmark. A half torus plays the role of the discrete imperfection. The influence of the presence of the imperfection, its position and the turbulence intensity of the free stream are analyzed. The measurement data are depicted as two-dimensional plots but also as integral values. It is found that the imperfection, placed one diameter from the hole leading edge, deteriorates the effectiveness at moderate velocity ratios. Under the same conditions, the same imperfection fixed at the hole exit improves the effectiveness. At the velocity ratio of 1.50, the exit imperfection improves the integral effectiveness relatively for more than two times. The turbulence intensity and imperfections placed deeper in the hole do not have a significant influence

An order batching algorithm for wave picking in a parallel-aisle warehouse

NARCIS (Netherlands)

Gademann, A.J.R.M.; Berg, van den J.P.; Hoff, van der H.H.

2001-01-01

In this paper we address the problem of batching orders in a parallel-aisle warehouse, with the objective to minimize the maximum lead time of any of the batches. This is a typical objective for a wave picking operation. Many heuristics have been suggested to solve order batching problems. We

Steady distribution structure of point defects near crystal-melt interface under pulling stop of CZ Si crystal

Science.gov (United States)

Abe, T.; Takahashi, T.; Shirai, K.

2017-02-01

In order to reveal a steady distribution structure of point defects of no growing Si on the solid-liquid interface, the crystals were grown at a high pulling rate, which Vs becomes predominant, and the pulling was suddenly stopped. After restoring the variations of the crystal by the pulling-stop, the crystals were then left in prolonged contact with the melt. Finally, the crystals were detached and rapidly cooled to freeze point defects and then a distribution of the point defects of the as-grown crystals was observed. As a result, a dislocation loop (DL) region, which is formed by the aggregation of interstitials (Is), was formed over the solid-liquid interface and was surrounded with a Vs-and-Is-free recombination region (Rc-region), although the entire crystals had been Vs rich in the beginning. It was also revealed that the crystal on the solid-liquid interface after the prolonged contact with the melt can partially have a Rc-region to be directly in contact with the melt, unlike a defect distribution of a solid-liquid interface that has been growing. This experimental result contradicts a hypothesis of Voronkov's diffusion model, which always assumes the equilibrium concentrations of Vs and Is as the boundary condition for distribution of point defects on the growth interface. The results were disscussed from a qualitative point of view of temperature distribution and thermal stress by the pulling-stop.

Thermal bump removal of a crystal monochromator by designing an optimal shape

Energy Technology Data Exchange (ETDEWEB)

Micha, Jean-Sébastien, E-mail: micha@esrf.fr [CRG-IF BM32 Beamline, ESRF, 6 rue J. Horowitz, BP 220, 38043 Grenoble (France); UMR SPrAM 5819, CEA-Grenoble/INAC/SPrAM, 17 avenue des Martyrs, 38054 Grenoble Cedex 9 (France); Geaymond, Olivier [CRG-IF BM32 Beamline, ESRF, 6 rue J. Horowitz, BP 220, 38043 Grenoble (France); Institut Néel, CNRS, 25 avenue des Martyrs, 38054 Grenoble Cedex 9 (France); Rieutord, Francois [CRG-IF BM32 Beamline, ESRF, 6 rue J. Horowitz, BP 220, 38043 Grenoble (France); CEA-Grenoble/INAC/NRS, 17 avenue des Martyrs, 38054 Grenoble Cedex 9 (France)

2013-05-11

Thermal bump arising at illuminated area of a water cooled monochromator crystal can be considerably reduced by designing an appropriate shape. Temperature and deformation have been simulated by finite element analysis (FEA) computations as a function of few geometrical parameters describing the shape of the crystal. As a result, a new crystal shape has been found which optimizes the throughput of a double crystals monochromator (DCM). Performances of the initial rectangular crystal and the new designed crystal predicted by FEA-based calculations and measured during experimental tests on a synchrotron beamline are reported. General design principles to overcome heat load issues and the objective function using the slope errors derived from FEA results are detailed. Current and foreseen performances at higher load are presented. Finally, advantages and limits of this simple-to-design and cheap solution are discussed.

Fed-batch coculture of Lactobacillus kefiranofaciens with Saccharomyces cerevisiae for effective production of kefiran.

Science.gov (United States)

Tada, Shiori; Katakura, Yoshio; Ninomiya, Kazuaki; Shioya, Suteaki

2007-06-01

In a batch coculture of kefiran-producing lactic acid bacteria Lactobacillus kefiranofaciens and lactate-assimilating yeast Saccharomyces cerevisiae, lactate accumulation in the medium was observed, which inhibited kefiran production. To enhance kefiran productivity by preventing lactate accumulation, we conducted lactose-feeding batch operation with feedforward/feedback control during the coculture, so that the lactate production rate of L. kefiranofaciens was balanced with the lactate consumption rate of S. cerevisiae. The lactate concentration was maintained at less than 6 g l(-1) throughout the fed-batch coculture using a 5 l jar fermentor, although the concentration reached 33 g l(-1) in the batch coculture. Kefiran production was increased to 6.3 g in 102 h in the fed-batch coculture, whereas 4.5 g kefiran was produced in 97 h in the batch coculture. The kefiran yield on lactose basis was increased up to 0.033 g g(-1) in the fed-batch coculture, whereas that in the batch coculture was 0.027 g g(-1).

Design of mirror and monochromator crystals for a high-resolution multiwavelength anomalous diffraction beam line on a bending magnet at the ESRF

International Nuclear Information System (INIS)

Roth, M.; Ferrer, J.; Simon, J.; Geissler, E.

1992-01-01

High intensity for diffraction experiments with high-energy resolution on an intense x-ray beam, like the bending magnet beam lines at the ESRF, requires a strict control of the curvature of the optical elements placed in the beam for geometrical focusing and for wavelength monochromatization. Unwanted curvatures can come from nonuniform and variable heating of the optical elements produced by the absorption of x rays. To design the CRG/D2AM beam line described in the accompanying paper, some new techniques were developed to control these effects based on geometrical, i.e., topological, considerations. (1) Cooling of the entrance mirror: longitudinal curvature can be strongly reduced by cooling the mirror from the sides (and not from the rear) and only near the reflecting surface (i.e., not over the whole lateral surface). The cooling can be achieved for instance with an isothermal liquid Ga eutectic bath. (2) Cooling of the first single-crystal Si monochromator: because of the size of the crystal, only cooling from the rear is conceivable in this case. It can be shown by calculation that the curvature due to the front-to-rear gradient can be exactly compensated by the thermal expansion of a metallic layer at the rear of the crystal, having a larger expansion coefficient than Si

Multiple batch recharging for industrial CZ silicon growth

Science.gov (United States)

Fickett, B.; Mihalik, G.

2001-05-01

The Czochralski (CZ) crystal growth process used in the Siemens Solar Industries’ (SSI) Vancouver, WA facility was non-continuous. Each furnace run's production was limited by the size of the starting charge. Once the charge was depleted, the furnace was shut down, cooled, and set back up for the next run. A recharge system was developed which transforms standard CZ growth into a semi-continuous process. Now when the charge is depleted, the crucible can be refilled in situ as the grown ingot is being removed from the furnace. SSI has demonstrated up to 14 recharge cycles in a single run. The resulting benefits included: significant cost reduction, increased yield, increased throughput, reduced energy consumption, improved process capability, reduced material handling requirements, and reduced labor. The recharge system also enables the use of granular silicon, which requires less than 30% of the energy required when manufacturing silicon-starting materials. This significantly reduces the energy “pay-back” time associated with SSI's finished product, photovoltaic panels.

Atomic and electronic structure transformations of silver nanoparticles under rapid cooling conditions.

Science.gov (United States)

Lobato, I; Rojas, J; Landauro, C V; Torres, J

2009-02-04

The structural evolution and dynamics of silver nanodrops Ag(2869) (4.4 nm in diameter) under rapid cooling conditions have been studied by means of molecular dynamics simulations and electronic density of state calculations. The interaction of silver atoms is modelled by a tight-binding semiempirical interatomic potential proposed by Cleri and Rosato. The pair correlation functions and the pair analysis technique are used to reveal the structural transition in the process of solidification. It is shown that Ag nanoparticles evolve into different nanostructures under different cooling processes. At a cooling rate of 1.5625 × 10(13) K s(-1) the nanoparticles preserve an amorphous-like structure containing a large amount of 1551 and 1541 pairs which correspond to icosahedral symmetry. For a lower cooling rate (1.5625 × 10(12) K s(-1)), the nanoparticles transform into a crystal-like structure consisting mainly of 1421 and 1422 pairs which correspond to the face centred cubic and hexagonal close packed structures, respectively. The variations of the electronic density of states for the differently cooled nanoparticles are small, but in correspondence with the structural changes.

Excitation of collective plasma modes during collisions between dust grains and the formation of dust plasma crystals

International Nuclear Information System (INIS)

Goree, J.A.; Morfill, G.; Tsytovich, V.N.

1998-01-01

Dust plasma crystals have recently been produced in experiments in a number of laboratories. For dust crystallization to occur, there should exist an efficient mechanism for the cooling of the dust plasma component. It is shown that the excitation of collective plasma modes during collisions between the grains may serve as the required cooling mechanism. The excitation of dust sound waves is found to be most efficient. It is shown that the cooling of dust grains via the excitation of collective plasma modes can be even more efficient than that due to collisions with neutral particles, which was previously considered to be the only mechanism for cooling of the dust plasma component. At present, the first experiments are being carried out to study collisions between individual dust grains. High efficiency of the excitation of plasma modes caused by collisions between dust grains is attributed to the coherent displacement of the plasma particles that shield the grains. it is shown that the excitation efficiency is proportional to the fourth power of the charge of the dust grains and to a large power of their relative velocity, and is independent of their mass. The results obtained can be checked in experiments studying how the binary collisions between dust grains and the pressure of the neutral component influence the dust crystallization

Exploring the Transition From Batch to Online

DEFF Research Database (Denmark)

Jørgensen, Anker Helms

2010-01-01

of the truly interactive use of computers known today. The transition invoked changes in a number of areas: technological, such as hybrid forms between batch and online; organisational such as decentralization; and personal as users and developers alike had to adopt new technology, shape new organizational...... structures, and acquire new skills. This work-in-progress paper extends an earlier study of the transition from batch to online, based on oral history interviews with (ex)-employees in two large Danish Service Bureaus. The paper takes the next step by ana-lyzing a particular genre: the commercial computer...

Pyroxenes in Serra de Mage - Cooling history in comparison with Moama and Moore County

Science.gov (United States)

Harlow, G. E.; Prinz, M.; Nehru, C. E.; Taylor, G. J.; Keil, K.

1979-01-01

Thin sections and single grains of pyroxenes from the Serra de Mage feldspar cumulate eucrites were studied by X-ray crystallography, electron microprobe and optical techniques. It was concluded that the pyroxene crystallized as pigeonite. On cooling augite was exsolved along (001) and inverted to hypersthene, with exsolution of (100) augite from hypersthene during continued slow cooling. The estimated original bulk composition of the pigeonite pyroxene is Wo10En51Fs39. The compositional data, textural relations, and existence of P2 sub 1 ca hypersthene suggest very low cooling (about 0.0004 deg C/year) below 800 deg. The Serra de Mage augite lamellae were found to be as thick or thicker than those of Moore County and Moama meteorites.

Comparison of the release of constituents from granular materials under batch and column testing.

Science.gov (United States)

Lopez Meza, Sarynna; Garrabrants, Andrew C; van der Sloot, Hans; Kosson, David S

2008-01-01

Column leaching testing can be considered a better basis for assessing field impact data than any other available batch test method and thus provides a fundamental basis from which to estimate constituent release under a variety of field conditions. However, column testing is time-intensive compared to the more simplified batch testing, and may not always be a viable option when making decisions for material reuse. Batch tests are used most frequently as a simple tool for compliance or quality control reasons. Therefore, it is important to compare the release that occurs under batch and column testing, and establish conservative interpretation protocols for extrapolation from batch data when column data are not available. Five different materials (concrete, construction debris, aluminum recycling residue, coal fly ash and bottom ash) were evaluated via batch and column testing, including different column flow regimes (continuously saturated and intermittent unsaturated flow). Constituent release data from batch and column tests were compared. Results showed no significant difference between the column flow regimes when constituent release data from batch and column tests were compared. In most cases batch and column testing agreed when presented in the form of cumulative release. For arsenic in carbonated materials, however, batch testing underestimates the column constituent release for most LS ratios and also on a cumulative basis. For cases when As is a constituent of concern, column testing may be required.

Optimization of the Production of Polygalacturonase from Aspergillus kawachii Cloned in Saccharomyces cerevisiae in Batch and Fed-Batch Cultures

Directory of Open Access Journals (Sweden)

Diego Jorge Baruque

2011-01-01

Full Text Available Polygalacturonases (PG; EC 3.2.1.15 catalyze the hydrolysis of pectin and/or pectic acid and are useful for industrial applications such as juice clarification and pectin extraction. Growth and heterologous expression of recombinant Saccharomyces cerevisiae which expresses an acidic PG from Aspergillus kawachii has been studied in batch and fed-batch cultures. Kinetics and stoichiometric parameters of the recombinant yeast were determined in batch cultures in a synthetic medium. In these cultures, the total biomass concentration, protein concentration, and enzyme activity achieved were 2.2 g/L, 10 mg/L, and 3 U/mL, respectively, to give a productivity of 0.06 U/(mL·h. In fed-batch cultures, various strategies for galactose feeding were used: (i after a glucose growth phase, the addition of a single pulse of galactose which gave a productivity of 0.19 U/(mL·h; (ii after a glucose growth phase, a double pulse of galactose at the same final concentration was added, resulting in a productivity of 0.21 U/(mL·h; (iii a simultaneous feeding of glucose and galactose, yielding a productivity of 1.32 U/(mL·h. Based on these results, the simultaneous feeding of glucose and galactose was by far the most suitable strategy for the production of this enzyme. Moreover, some biochemical characteristics of the recombinant enzyme such as a molecular mass of ~60 kDa, an isoelectric point of 3.7 and its ability to hydrolyze polygalacturonic acid at pH=2.5 were determined.

Development and test of small-scale batch-fired straw boilers in Denmark

International Nuclear Information System (INIS)

Kristensen, E.F.; Kristensen, J.K.

2004-01-01

In Denmark, government subsidies for the testing and installation of biomass-fired boilers were available for the period from 1995 until 2002. Each boiler type had to pass an official approval test to achieve subsidy. The combustion abilities of the boiler were optimized prior to the test. The main aim of this subsidy was to encourage the development of energy-efficient and environmentally friendly boilers. The scheme was therefore organized in such a way that the greatest subsidies were awarded for boilers with high efficiency and low emissions. This goal has in effect been achieved for batch-fired straw boilers, where the typical efficiency has been increased from about 75% in 1995 to about 87% in 2002. Similarly, the carbon monoxide emissions have been reduced from 5000 ppm (reference value 10% O 2 ) in 1995 to less than 1000 ppm in 2002. These improvements are mainly due to better insulation inside the combustion chamber, more efficient techniques for supplying air to the combustion process, improved cooling of the flue gas, and optimization of the electronic control unit for the air supply

Crystallization and preliminary X-ray characterization of the eukaryotic replication terminator Reb1-Ter DNA complex.

Science.gov (United States)

Jaiswal, Rahul; Singh, Samarendra K; Bastia, Deepak; Escalante, Carlos R

2015-04-01

The Reb1 protein from Schizosaccharomyces pombe is a member of a family of proteins that control programmed replication termination and/or transcription termination in eukaryotic cells. These events occur at naturally occurring replication fork barriers (RFBs), where Reb1 binds to termination (Ter) DNA sites and coordinates the polar arrest of replication forks and transcription approaching in opposite directions. The Reb1 DNA-binding and replication-termination domain was expressed in Escherichia coli, purified and crystallized in complex with a 26-mer DNA Ter site. Batch crystallization under oil was required to produce crystals of good quality for data collection. Crystals grew in space group P2₁, with unit-cell parameters a = 68.9, b = 162.9, c = 71.1 Å, β = 94.7°. The crystals diffracted to a resolution of 3.0 Å. The crystals were mosaic and required two or three cycles of annealing. This study is the first to yield structural information about this important family of proteins and will provide insights into the mechanism of replication and transcription termination.

Homogeneous crystal nucleation in polymers.

Science.gov (United States)

Schick, C; Androsch, R; Schmelzer, J W P

2017-11-15

The pathway of crystal nucleation significantly influences the structure and properties of semi-crystalline polymers. Crystal nucleation is normally heterogeneous at low supercooling, and homogeneous at high supercooling, of the polymer melt. Homogeneous nucleation in bulk polymers has been, so far, hardly accessible experimentally, and was even doubted to occur at all. This topical review summarizes experimental findings on homogeneous crystal nucleation in polymers. Recently developed fast scanning calorimetry, with cooling and heating rates up to 10 6 K s -1 , allows for detailed investigations of nucleation near and even below the glass transition temperature, including analysis of nuclei stability. As for other materials, the maximum homogeneous nucleation rate for polymers is located close to the glass transition temperature. In the experiments discussed here, it is shown that polymer nucleation is homogeneous at such temperatures. Homogeneous nucleation in polymers is discussed in the framework of the classical nucleation theory. The majority of our observations are consistent with the theory. The discrepancies may guide further research, particularly experiments to progress theoretical development. Progress in the understanding of homogeneous nucleation is much needed, since most of the modelling approaches dealing with polymer crystallization exclusively consider homogeneous nucleation. This is also the basis for advancing theoretical approaches to the much more complex phenomena governing heterogeneous nucleation.

A Model of Batch Scheduling for a Single Batch Processor with Additional Setups to Minimize Total Inventory Holding Cost of Parts of a Single Item Requested at Multi-due-date

Science.gov (United States)

Hakim Halim, Abdul; Ernawati; Hidayat, Nita P. A.

2018-03-01

This paper deals with a model of batch scheduling for a single batch processor on which a number of parts of a single items are to be processed. The process needs two kinds of setups, i. e., main setups required before processing any batches, and additional setups required repeatedly after the batch processor completes a certain number of batches. The parts to be processed arrive at the shop floor at the times coinciding with their respective starting times of processing, and the completed parts are to be delivered at multiple due dates. The objective adopted for the model is that of minimizing total inventory holding cost consisting of holding cost per unit time for a part in completed batches, and that in in-process batches. The formulation of total inventory holding cost is derived from the so-called actual flow time defined as the interval between arrival times of parts at the production line and delivery times of the completed parts. The actual flow time satisfies not only minimum inventory but also arrival and delivery just in times. An algorithm to solve the model is proposed and a numerical example is shown.

Simulated Batch Production of Penicillin

Science.gov (United States)

Whitaker, A.; Walker, J. D.

1973-01-01

Describes a program in applied biology in which the simulation of the production of penicillin in a batch fermentor is used as a teaching technique to give students experience before handling a genuine industrial fermentation process. Details are given for the calculation of minimum production cost. (JR)

Microbial analysis of meatballs cooled with vacuum and conventional cooling.

Science.gov (United States)

Ozturk, Hande Mutlu; Ozturk, Harun Kemal; Koçar, Gunnur

2017-08-01

Vacuum cooling is a rapid evaporative cooling technique and can be used for pre-cooling of leafy vegetables, mushroom, bakery, fishery, sauces, cooked food, meat and particulate foods. The aim of this study was to apply the vacuum cooling and the conventional cooling techniques for the cooling of the meatball and to show the vacuum pressure effect on the cooling time, the temperature decrease and microbial growth rate. The results of the vacuum cooling and the conventional cooling (cooling in the refrigerator) were compared with each other for different temperatures. The study shows that the conventional cooling was much slower than the vacuum cooling. Moreover, the microbial growth rate of the vacuum cooling was extremely low compared with the conventional cooling. Thus, the lowest microbial growth occurred at 0.7 kPa and the highest microbial growth was observed at 1.5 kPa for the vacuum cooling. The mass loss ratio for the conventional cooling and vacuum cooling was about 5 and 9% respectively.

Habit modification of potassium acid phthalate (KAP) single crystals by impurities

Science.gov (United States)

Murugakoothan, P.; Mohan Kumar, R.; Ushasree, P. M.; Jayavel, R.; Dhanasekaran, R.; Ramasamy, P.

1999-12-01

Nonlinear optical materials potassium dihydrogen phosphate (KDP), urea and L-arginine phosphate (LAP)-doped KAP crystals were grown by the slow cooling method. The LAP-doped crystals show pronounced habit modification compared to KDP and urea doping. The effect of these impurities on growth kinetics, surface morphology, habit modification, structure, optical and mechanical properties have been studied. Among the three impurities, urea doping yields high mechanical stability and optical transmission and for KDP and LAP doping there is a decrease in optical transmission.

Crystal Structure and Spectroscopic Characterization of K8(VO)2O(SO4)6:

DEFF Research Database (Denmark)

Rasmussen, Søren Birk; Rasmussen, Rikke Christina; Fehrmann, Rasmus

2003-01-01

Red and yellow dichroistic crystals of a vanadium(V) compound, potassium (mu-oxo, di-mu-suifato)bis(oxodisulfato-vanadate), K-8(VO)(2)O(SO4)(6), have been obtained from the ternary catalytic model melt system K2S2O7-K2SO4-V2O5. By slow cooling of the melt from 420 to 355 degreesC, crystal growth...

Neutron production with a pyroelectric double-crystal assembly without nano-tip

Energy Technology Data Exchange (ETDEWEB)

Tornow, W., E-mail: tornow@tunl.duke.ed [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Corse, W. [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Crimi, S. [Harriet L. Wilkes Honors College, Florida Atlantic University, Jupiter, FL 33458 (United States); Fox, J. [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)

2010-12-21

Two cylindrical LiTaO{sub 3} crystals facing each other's deuterated circular face were exposed to deuterium gas at an ambient pressure of a few mTorr. With a distance of about 4 cm between the z{sup +} and z{sup -} cut crystal faces, neutrons were produced via the {sup 2}H(d,n){sup 3}He fusion reaction upon the heating and cooling of the crystals. The 2.5 MeV neutrons were detected with organic liquid scintillation detectors equipped with neutron-gamma pulse-shape discrimination electronics to reject pulses generated by the intense X-ray flux. During the cooling phase of naked crystals, deuterium ion-beam (D{sub 2}{sup +}) energies of up to 400 keV were obtained as deduced from the associated electron bremsstrahlung end-point energy. The highest electron-beam energy observed during the heating phase was 360 keV. With a layer of deuterated polyethylene evaporated on the front face of the crystals, the maximal energies were about 10% lower. In contrast to earlier studies, an electric-field enhancing nano-tip was not employed. Neutron yields up to 500 per thermal cycle were observed, resulting in a total neutron production yield of about 1.6x10{sup 4} neutrons per thermal cycle. Our approach has the potential of being substantially improved by reducing the frequency of the discharges we are currently experiencing with our geometry, which was not designed for the unprecedented high potentials produced in the presentwork.

Cooling techniques

International Nuclear Information System (INIS)

Moeller, S.P.

1994-01-01

After an introduction to the general concepts of cooling of charged particle beams, some specific cooling methods are discussed, namely stochastic, electron and laser cooling. The treatment concentrates on the physical ideas of the cooling methods and only very crude derivations of cooling times are given. At the end three other proposed cooling schemes are briefly discussed. (orig.)

A study on effective thermal conductivity of crystalline layers in layer melt crystallization

International Nuclear Information System (INIS)

Kim, Kwang-Joo; Ulrich, Joachim

2002-01-01

An effective thermal conductivity in layer melt crystallization was explored based on a model considering inclusions inside a crystalline layer during crystal growth, molecular diffusion of inclusions migration due to temperature gradient and heat generation due to recrystallization of inclusions in the crystalline layer. The effective thermal conductivity increases with time, in general, as a result of compactness of the layer. Lower cooling temperature, i.e. greater supercooling, results in a more porous layer with lower effective thermal conductivity. A similar result is seen for the parameter of melt temperature, but less pronounced. A high concentration of the melt results in a high effective thermal conductivity while low concentration yields low effective thermal conductivity. At higher impurity levels in the melt phase, constitutional supercooling becomes more pronounced and unstable growth morphologies occur more easily. Cooling rate and Reynolds number also affect the effective thermal conductivity. The predictions of an effective thermal conductivity agree with the experimental data. The model was applied to estimate the thermal conductivities of the crystalline layer during layer melt crystallization. (author)

Surface energy and crystallization phenomena of ammonium dinitramide

Energy Technology Data Exchange (ETDEWEB)

Teipel, Ulrich; Heintz, Thomas [Fraunhofer-Institut fuer Chemische Technologie (ICT), PO Box 1240, D-76318 Pfinztal (Germany)

2005-12-01

Ammonium dinitramide (ADN) was characterized during recrystallization from the melt. The surface tension of molten ADN at 97 C was measured to be 89 mN/m. The wetting angles between molten ADN and different solid surfaces (polytetrafluoroethylene, glass, steel, and aluminum) were determined. The wettability depends on the surface tension of molten ADN, the free surface energy of the solid surfaces and the interfacial tension between the solid and liquid. Observations of the recrystallization behavior of molten ADN showed that nucleation does not occur, even at super cooling rates of 70 K. Crystallization can be initiated by the application of seed crystals. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

Response variation in a batch of TLDS

International Nuclear Information System (INIS)

Burrage, J.; Campbell, A.

2004-01-01

Full text: At Royal Perth Hospital, LiF thermoluminescent dosimeter rods (TLDs) are handled in batches of 50. Rods in each batch are always annealed together to ensure the same thermal history and an individual batch is used with the same type and energy of radiation. A subset of a batch is used for calibration purposes by exposing them to a range of known doses and their output is used to calculate the dose received by other rods used for a dose measurement. Variation in TLD response is addressed by calculating 95% certainty levels from the calibration rods and applying this to the dose measurement rods. This approach relies on the sensitivity of rods within each batch being similar. This work investigates the validity of this assumption and considers possible benefits of applying individual rod sensitivities. The variation in response of TLD rods was assessed using 25 TLD-100 rods (Harshaw/Bicron) which were uniformly exposed to 1 Gy using 6 MeV photons in a linear accelerator on 5 separate occasions. Rods were read with a Harshaw 5500 reader. During the read process the Harshaw reader periodically checks for noise and PMT gain drift and the data were corrected for these parameters. Replicate exposure data were analysed using 1-way Analysis of Variance (ANOVA) to determine whether the between rod variations were significantly different to the variations within a single rod. A batch of 50 rods was also exposed on three occasions using the above technique. Individual TLD rod sensitivity values were determined using the rod responses from 2 exposures and these values were applied to correct charges on a rod-by-rod basis for the third exposure. ANOVA results on the 5 exposures of 25 rods showed the variance between rods was significantly greater than the within rod variance (p < 0.001). The precision of an individual rod was estimated to have a standard deviation of 2.8%. This suggests that the 95% confidence limits for repeated measurements using the same dose and

Magnetic order of Nd5Pb3 single crystals

Science.gov (United States)

Yan, J.-Q.; Ochi, M.; Cao, H. B.; Saparov, B.; Cheng, J.-G.; Uwatoko, Y.; Arita, R.; Sales, B. C.; Mandrus, D. G.

2018-04-01

We report millimeter-sized Nd5Pb3 single crystals grown out of a Nd-Co flux. We experimentally study the magnetic order of Nd5Pb3 single crystals by measuring the anisotropic magnetic properties, electrical resistivity under high pressure up to 8 GPa, specific heat, and neutron single crystal diffraction. Two successive magnetic orders are observed at T N1  =  44 K and T N2  =  8 K. The magnetic cells can be described with a propagation vector k=(0.5, 0, 0) . Cooling below T N1, Nd1 and Nd3 order forming ferromagnetic stripes along the b-axis, and the ferromagnetic stripes are coupled antiferromagnetically along the a-axis for the k=(0.5, 0, 0) magnetic domain. Cooling below T N2, Nd2 orders antiferromagnetically to nearby Nd3 ions. All ordered moments align along the crystallographic c-axis. The magnetic order at T N1 is accompanied by a quick drop of electrical resistivity upon cooling and a lambda-type anomaly in the temperature dependence of specific heat. At T N2, no anomaly was observed in electrical resistivity but there is a weak feature in specific heat. The resistivity measurements under hydrostatic pressures up to 8 GPa suggest a possible phase transition around 6 GPa. Our first-principles band structure calculations show that Nd5Pb3 has the same electronic structure as does Y5Si3 which has been reported to be a one-dimensional electride with anionic electrons that do not belong to any atom. Our study suggests that R 5Pb3 (R  =  rare earth) can be a materials playground for the study of magnetic electrides. This deserves further study after experimental confirmation of the presence of anionic electrons.

Dose and batch-dependent hepatobiliary toxicity of 10 nm silver nanoparticles

Directory of Open Access Journals (Sweden)

Marcella De Maglie

2015-07-01

Full Text Available Silver nanoparticles (AgNPs are widely used because of their antimicrobial properties in medical devices and in a variety of consumer products. The extensive use of AgNPs raises concerns about their potential toxicity, although it is still difficult to draw definite conclusions about their toxicity based on published data. Our preliminary studies performed to compare the effect of the AgNPs size (10-40-100 nm on toxicity, demonstrated that the smallest AgNPs determine the most severe toxicological effects. In order to best investigate the impact of physicochemical characteristics of 10 nm AgNPs on toxicity, we compare three different batches of 10 nm AgNPs slightly different in size distribution (Batch A: 8.8±1.7 nm; Batch B: 9.4±1.7 nm; Batch C: 10.0±1.8 nm. Mice were intravenously treated with two doses (5 and 10 mg/kg of the 3 AgNPs. 24 hours after the treatment, mice were euthanized and underwent complete necropsy. Tissues were collected for histopathological examination and total silver content was determined in tissues by inductively coupled plasma mass spectrometry (ICP-MS. All batches induced severe hepatobiliary lesions, i.e. marked hepatocellular necrosis and massive hemorrhage of the gall bladder. The toxicity was dose-dependent and interestingly, the toxic effects were more severe in mice treated with batches A and B that contained smaller AgNPs. Since the total silver mass concentration was similar, the observed batch-dependent toxicity suggest that even subtle differences in size may contribute to relevant changes in the toxicological outcomes, confirming the fundamental involvement of physicochemical features with respect to toxicity.

Cloning, multicopy expression and fed-batch production of Rhodotorula araucariae epoxide hydrolase in yarrowia lipolytica

CSIR Research Space (South Africa)

Ramduth, D

2008-05-01

Full Text Available demonstrated a 4 fold enhanced EH activity over the transformant. The transformant was then evaluated in batch and fed batch fermentations, where the batch fermentations resulted in - 50% improved EH activity from flask evaluations. In fed batch fermentations...

The performance studies of DKDP crystals grown by a rapid horizontal growth method

Science.gov (United States)

Xie, Xiaoyi; Qi, Hongji; Wang, Bin; Wang, Hu; Chen, Duanyang; Shao, Jianda

2018-04-01

A deuterated potassium dihydrogen phosphate (DKDP) crystal with about 70% deuterium level was grown by a rapid horizontal growth method with independent design equipment, which includes a continuous filtration system. The cooling program during crystal growth was designed according to a self-developed software to catch the size of growing crystal in real time. The crystal structure, optical performance and laser induced damage threshold (LIDT) of this DKDP crystal were investigated in this paper. The deuterium concentration of the crystal was confirmed by the neutron diffraction technique, which was effective and available in determining a complete range of deuteration level. The dielectric property was measured to evaluate the perfection of the lattice. The transmittance and LIDT were carried out further to evaluate the optical and functional properties of this DKDP crystal grown in the rapid horizontal growth technique. All of the detailed characterization for DKDP figured out that the 70% deuterated KDP crystal grown in this way had relatively good qualities.

Simple approximations for the batch-arrival MX/G/1 queue

NARCIS (Netherlands)

van Ommeren, Jan C.W.

1990-01-01

In this paper we consider the MX/G/I queueing system with batch arrivals. We give simple approximations for the waiting-time probabilities of individual customers. These approximations are checked numerically and they are found to perform very well for a wide variety of batch-size and service-timed

Look-ahead strategies for controlling batch operations in industry - overview, comparison and exploration

NARCIS (Netherlands)

Zee, D.J. van der; Harten, A. van; Schuur, P.C.; Joines, JA; Barton, RR; Kang, K; Fishwick, PA

2000-01-01

Batching jobs in a manufacturing system is a very common policy in most industries. The main reasons for batching are avoidance of set ups and/or facilitation of material handling. Good examples of batch-wise production systems are ovens found in aircraft industry and in semiconductor manufacturing.

Kinetic studies on batch cultivation of Trichoderma reesei and application to enhance cellulase production by fed-batch fermentation.

Science.gov (United States)

Ma, Lijuan; Li, Chen; Yang, Zhenhua; Jia, Wendi; Zhang, Dongyuan; Chen, Shulin

2013-07-20

Reducing the production cost of cellulase as the key enzyme for cellulose hydrolysis to fermentable sugars remains a major challenge for biofuel production. Because of the complexity of cellulase production, kinetic modeling and mass balance calculation can be used as effective tools for process design and optimization. In this study, kinetic models for cell growth, substrate consumption and cellulase production in batch fermentation were developed, and then applied in fed-batch fermentation to enhance cellulase production. Inhibition effect of substrate was considered and a modified Luedeking-Piret model was developed for cellulase production and substrate consumption according to the growth characteristics of Trichoderma reesei. The model predictions fit well with the experimental data. Simulation results showed that higher initial substrate concentration led to decrease of cellulase production rate. Mass balance and kinetic simulation results were applied to determine the feeding strategy. Cellulase production and its corresponding productivity increased by 82.13% after employing the proper feeding strategy in fed-batch fermentation. This method combining mathematics and chemometrics by kinetic modeling and mass balance can not only improve cellulase fermentation process, but also help to better understand the cellulase fermentation process. The model development can also provide insight to other similar fermentation processes. Copyright © 2013 Elsevier B.V. All rights reserved.

Study of the growth and pyroelectric properties of TGS crystals doped with aniline-family dipolar molecules

Science.gov (United States)

Zhang, Kecong; Song, Jiancheng; Wang, Min; Fang, Changshui; Lu, Mengkai

1987-04-01

TGS crystals doped with aniline-family dipolar molecules (aniline, 2-aminobenzoic acid, 3-aminobenzoic acid, 3-aminobenzene-sulphonic acid, 4-aminobenzenesulphonic acid and 4-nitroraniline) have been grown by the slow-cooling solution method. The influence of these dopants on the growth habits, crystal morphology pyroelectric properties, and structure parameters of TGS crystals has been systematically investigated. The effects of the domain structure of the seed crystal on the pyroelectric properties of the doped crystals have been studied. It is found that the spontaneous polarization (P), pyroelectric coefficient (lambda), and internal bias field of the doped crystals are slightly higher than those of the pure TGS, and the larger the dipole moment of the dopant molecule, the higher the P and lambda of the doped TGS crystal.

Factors Affecting the Changes of Ice Crystal Form in Ice Cream

Science.gov (United States)

Wang, Xin; Watanabe, Manabu; Suzuki, Toru

In this study, the shape of ice crystals in ice cream was quantitatively evaluated by introducing fractal analysis. A small droplet of commercial ice cream mix was quickly cooled to about -30°C on the cold stage of microscope. Subsequently, it was heated to -5°C or -10°C and then held for various holding time. Based on the captured images at each holding time, the cross-sectional area and the length of circumference for each ice crystal were measured to calculate fractal dimension using image analysis software. The results showed that the ice crystals were categorized into two groups, e.g. simple-shape and complicated-shape, according to their fractal dimensions. The fractal dimension of ice crystals became lower with increasing holding time and holding temperature. It was also indicated that the growing rate of complicated-shape ice crystals was relatively higher because of aggregation.

Seeded growth of boron arsenide single crystals with high thermal conductivity

Science.gov (United States)

Tian, Fei; Song, Bai; Lv, Bing; Sun, Jingying; Huyan, Shuyuan; Wu, Qi; Mao, Jun; Ni, Yizhou; Ding, Zhiwei; Huberman, Samuel; Liu, Te-Huan; Chen, Gang; Chen, Shuo; Chu, Ching-Wu; Ren, Zhifeng

2018-01-01

Materials with high thermal conductivities are crucial to effectively cooling high-power-density electronic and optoelectronic devices. Recently, zinc-blende boron arsenide (BAs) has been predicted to have a very high thermal conductivity of over 2000 W m-1 K-1 at room temperature by first-principles calculations, rendering it a close competitor for diamond which holds the highest thermal conductivity among bulk materials. Experimental demonstration, however, has proved extremely challenging, especially in the preparation of large high quality single crystals. Although BAs crystals have been previously grown by chemical vapor transport (CVT), the growth process relies on spontaneous nucleation and results in small crystals with multiple grains and various defects. Here, we report a controllable CVT synthesis of large single BAs crystals (400-600 μm) by using carefully selected tiny BAs single crystals as seeds. We have obtained BAs single crystals with a thermal conductivity of 351 ± 21 W m-1 K-1 at room temperature, which is almost twice as conductive as previously reported BAs crystals. Further improvement along this direction is very likely.

Crystal Structure of Tetragonal Form of La2NiO4+x

Science.gov (United States)

Kajitani, Tsuyoshi; Hosoya, Syoichi; Hirabayashi, Makoto; Fukuda, Tsuguo; Onozuka, Takashi

1989-10-01

The crystal structure of the title oxide was studied by means of the X-ray and neutron single crystal diffraction measurements. At room temperature, the tetragonal crystal structure is P42/ncm-type (No. 138), which is one of the subgroup of the space group I4/mmm. The lattice parameters of a sample annealed and slowly cooled in oxygen atmosphere from 673 K are a{=}b{=}5.4640(1) Å and c{=}12.6719(2) Å, while the oxygen content, x{=}0.10(4), was determined from obtained neutron data. The title oxide undergoes a tetragonal (P42/ncm)/tetragonal (I4/mmm) phase transition at about 560 K. The transition temperature is almost identical both in the annealed and as-grown crystals.

Experimental results of a direct air-cooled ammonia–lithium nitrate absorption refrigeration system

International Nuclear Information System (INIS)

Llamas-Guillén, S.U.; Cuevas, R.; Best, R.; Gómez, V.H.

2014-01-01

Absorption thermal cooling systems driven by renewable energy are a viable option in order to reduce fossil fuel consumption and the associated emissions. This work shows the results of an air cooled absorption cooling prototype working with an ammonia–lithium nitrate mixture at high ambient temperatures. An absorption refrigeration system was designed and built. The prototype is a one stage ammonia–lithium nitrate air cooled chiller. The experimental system was instrumented to evaluate each component. This paper shows the operation conditions in the experimental unit as well as some of the heat loads encountered at different operating conditions. The system was operated successfully at ambient temperatures in the range of 25–35 °C. A series of test showed that even at ambient temperatures it can be operated at evaporator temperatures below 10 °C producing chilled water for air conditioning applications such as radiative cooling panels. The system proved to stabilize very quickly and no risk of crystallization was encountered so the first results are promising in order to continue with the development of a more advanced prototype. - Highlights: •Experimental results of a direct air-cooled ammonia–lithium nitrate system. •The prototype is a one stage ammonia–lithium nitrate air cooled chiller. •The absorption system was operated successfully at ambient temperatures. •Cooling loads of 4.5 kW were reached in the chilled water side

Atomic size effect on critical cooling rate and glass formation

International Nuclear Information System (INIS)

Jalali, Payman; Li Mo

2005-01-01

Atomic size effect on critical cooling rate and glass formability in a model binary system is investigated using molecular dynamics simulation. To isolate atomic size effect from the rest of the factors that critically influence the glass formation, a hard sphere model is employed in conjunction with a newly developed densification method. The glass formability is defined as a set of optimal conditions that result in the slowest cooling rate of the glass-forming liquid. Critical cooling rates are identified from extensive molecular dynamics simulations. A kinetic glass-forming diagram is mapped out that marks the boundary between the glass-forming regions and competing crystalline phases in terms of the parameters of the atomic size ratio and alloy concentration. It is found that the potency of the atomic size difference on glass formation is influenced greatly by the competing metastable and equilibrium crystalline phases in the system, and the kinetic processes leading to the formation of these phases. The mechanisms of the atomic size effect on topological instability of crystal packing and glass formation are discussed

Deflection of GeV particle beams by channeling in bent crystal planes of constant curvature

International Nuclear Information System (INIS)

Forster, J.S.; Hatton, H.; Toone, R.J.

1989-01-01

The deflection of charged particle beams moving within the (110) planes of a 43 mm long silicon crystal has been observed for momenta from 60 to 200 GeV/c. The crystal was bent by a 10.8 μm thick coating of ZnO along the central 26 mm of the crystal. Measurements were made with the crystal at room temperature, where a total deflection of 32.5 mrad was observed, and with the crystal cooled to -145 o C, where a 30.9 mrad deflection was observed. The ratio of the number of particles that dechannel upon entering the bend to the number of initially channeled particles compares well with calculations based on the continuum model. (author)

Growth of high-temperature superconductor crystals from flux

International Nuclear Information System (INIS)

Demianets, L.N.; Bykov, A.B.; Melnikov, O.K.; Stishov, S.M.

1991-01-01

Crystallization of high-temperature superconductors was studied in La-Sr-Cu-O, Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O systems. Platelet crystals YBa 2 Cu 3 Osub(6.5+x) were obtained by spontaneous crystallization from homogeneous nonstoichiometric melts enriched in barium and copper oxides. Lasub(2-x)Sr x CuO 4 was prepared by slow cooling of melts enriched in copper oxide. Bi 2 (Sr, Ca)sub(n+1)Cu n O y , (n=1;2) was obtained by melting zone travelling. The crystals show transition to superconducting state at T=93K, ΔT 0.2-0.5 K (Y, Ba cuprate), T=87K, ΔT 2K (Bi, Sr, Ca-cuprate). La, Sr-cuprate single crystals obtained by Czochralski method did not show transition to superconducting state. For flux-grown crystals T c was 5-26 K depending on the composition, growth and heat treatment. The short characterization of some accessory phases (Ba 3 Y 2 Cu 3 PtO 10 , Casub(1.75)Srsub(1.5)Cusub(0.75)PtO 6 , BaCuO 2 , Ba 41 Cu 44 O 84 Cl 2 ) is reported. (author). 15 ref s., 8 figs

Study of phosphoric acid crystallization using a focused beam reflectance measurement method

Energy Technology Data Exchange (ETDEWEB)

Ma, Yong [School of Chemistry and Resource Environment, Linyi Normal University, Linyi Shandong 276005 (China); Chen, Kui; Wu, Yanyang; Zhu, Jiawen [Chemical Engineering Research Center, East China University of Science and Technology, Shanghai 200237 (China); Sheng, Yong [SINOCHEN Fuling Chemical Industrial Co., Ltd, Chongqing 226005 (China)

2010-10-15

A way for restoring the crystal size distributions (CSD) from measured chord length distributions (CLD) was reported in this paper. The kinetics of phosphoric acid crystallization process was investigated in cooling mode using focused beam reflectance measurement (FBRM) and digital photo technique. In order to restore the CSD from measured CLD and verify the reliability of FBRM data, digital photo technique in real time and optical microscope were applied in large crystal size and small range, respectively. Results indicated a converting constant A existed between CLD and CSD when crystal growth follows size-independent growth (Mcabe's {delta}L law) law. It was verified by Malvern particles size analysis method. The converting constant A varied with crystal morphology. The crystal growth order increased with the stirring increasing speed during phosphoric acid crystallization process. The trend was especially notable at higher speed situations. It can illustrate that the state of phosphoric acid hemihydrate crystal growth was controlled by both diffusion and surface-integration with the increasing stirring speed. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

40 CFR 1065.245 - Sample flow meter for batch sampling.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Sample flow meter for batch sampling... Sample flow meter for batch sampling. (a) Application. Use a sample flow meter to determine sample flow... difference between a diluted exhaust sample flow meter and a dilution air meter to calculate raw exhaust flow...

Farm batch system and Fermi inter-process communication and synchronization toolkit

International Nuclear Information System (INIS)

Mandrichenko, I.V.

2001-01-01

Farms Batch System (FBS) was developed as a batch process management system for off-line Run II data processing at Fermilab. FBS will manage PC farms composed of up to 250 nodes and scalable to 1000 nodes with disk capacity of up to several TB. FBS allows users to start arrays of parallel processes on multiple computers. It uses a simplified resource counting method load balancing. FBS has been successfully used for more than a year at Fermilab by fixed target experiments and will be used for collider experiment off-line data processing. Fermi Inter-Process Communication toolkit (FIPC) was designed as a supplement product for FBS that helps establish synchronization and communication between processes running in a distributed batch environment. However, FIPC is an independent package, and can be used with other batch systems, as well as in a non-batch environment. FIPC provides users with a variety of global distributed objects such as semaphores, queues and string variables. Other types of objects can be easily added to FIPC. FIPC has been running on several PC farms at Fermilab for half a year and is going to be used by CDF for off-line data processing

Removing batch effects for prediction problems with frozen surrogate variable analysis

Directory of Open Access Journals (Sweden)

Hilary S. Parker

2014-09-01

Full Text Available Batch effects are responsible for the failure of promising genomic prognostic signatures, major ambiguities in published genomic results, and retractions of widely-publicized findings. Batch effect corrections have been developed to remove these artifacts, but they are designed to be used in population studies. But genomic technologies are beginning to be used in clinical applications where samples are analyzed one at a time for diagnostic, prognostic, and predictive applications. There are currently no batch correction methods that have been developed specifically for prediction. In this paper, we propose an new method called frozen surrogate variable analysis (fSVA that borrows strength from a training set for individual sample batch correction. We show that fSVA improves prediction accuracy in simulations and in public genomic studies. fSVA is available as part of the sva Bioconductor package.

Fabrication and characterization of poly(L-lactic acid) gels induced by fibrous complex crystallization with solvents

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Yasuhiro [ORNL; Fukatsu, Akinobu [Shizuoka University, Hamamatsu, Japan; Wang, Yangyang [ORNL; Miyamoto, Kazuaki [Shizuoka University, Hamamatsu, Japan; Mays, Jimmy [University of Tennessee, Knoxville (UTK); Tasaka, Shigeru [Shizuoka University, Hamamatsu, Japan

2014-01-01

Complex crystal induced gelation of poly(L-lactic acid) (PLLA) solutions was studied for a series of solvents, including N,N-dimethylformamide (DMF). By cooling the solutions prepared at elevated temperatures, PLLA gels were produced in solvents that induced complex crystals ( -crystals) with PLLA. Fibrous structure of PLLA in the gel with DMF was observed by polarizing optical microscopy, field emission electron microscopy, and atomic force microscopy. Upon heating, the crystal form of PLLA in the DMF gel changed from -crystal to a-crystal, the major crystal form in common untreated PLLA films, but the morphology and high elastic modulus of the gel remained until the a-crystal dissolved at higher temperature. In addition, a solvent exchanging method was developed, which allowed PLLA gels to be prepared in other useful solvents that do not induce -crystals without losing the morphology and mechanical properties.

Dependence of the residual surface resistance of superconducting radio frequency cavities on the cooling dynamics around T{sub c}

Energy Technology Data Exchange (ETDEWEB)

Romanenko, A., E-mail: aroman@fnal.gov; Grassellino, A., E-mail: annag@fnal.gov; Melnychuk, O.; Sergatskov, D. A. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)

2014-05-14

We report a strong effect of the cooling dynamics through T{sub c} on the amount of trapped external magnetic flux in superconducting niobium cavities. The effect is similar for fine grain and single crystal niobium and all surface treatments including electropolishing with and without 120 °C baking and nitrogen doping. Direct magnetic field measurements on the cavity walls show that the effect stems from changes in the flux trapping efficiency: slow cooling leads to almost complete flux trapping and higher residual resistance, while fast cooling leads to the much more efficient flux expulsion and lower residual resistance.

TIME-TEMPERATURE-TRANSFORMATION DIAGRAMS FOR THE SLUDGE BATCH 3 - FRIT 418 GLASS SYSTEM

International Nuclear Information System (INIS)

Billings, A.; Edwards, Tommy

2009-01-01

As a part of the Waste Acceptance Product Specifications (WAPS) for Vitrified High-Level Waste Forms defined by the Department of Energy - Office of Environmental Management, the phase stability must be determined for each of the projected high-level waste (HLW) types at the Savannah River Site (SRS). Specifically, WAPS 1.4.1 requires the glass transition temperature (Tg) to be defined and time-temperature-transformation (TTT) diagrams to be developed. The Tg of a glass is an indicator of the approximate temperature where the supercooled liquid converts to a solid on cooling or conversely, where the solid begins to behave as a viscoelastic solid on heating. A TTT diagram identifies the crystalline phases that can form as a function of time and temperature for a given waste type or more specifically, the borosilicate glass waste form. In order to assess durability, the Product Consistency Test (PCT) was used and the durability results compared to the Environmental Assessment (EA) glass. The measurement of glass transition temperature and the development of TTT diagrams have already been performed for the seven Defense Waste Processing Facility (DWPF) projected compositions as defined in the Waste Form Compliance Plan (WCP). These measurements were performed before DWPF start-up and the results were incorporated in Volume 7 of the Waste Form Qualification Report (WQR). Additional information exists for other projected compositions, but overall these compositions did not consider some of the processing scenarios now envisioned for DWPF to accelerate throughput. Changes in DWPF processing strategy have required this WAPS specification to be revisited to ensure that the resulting phases have been bounded. Frit 418 was primarily used to process HLW Sludge Batch 3 (SB3) at 38% waste loading (WL) through the DWPF. The Savannah River National Laboratory (SRNL) fabricated a cache of glass from reagent grade oxides to simulate the SB3-Frit 418 system at a 38 wt % WL for glass

Effects of Undercooling and Cooling Rate on Peritectic Phase Crystallization Within Ni-Zr Alloy Melt

Science.gov (United States)

Lü, P.; Wang, H. P.

2018-04-01

The liquid Ni-16.75 at. pct Zr peritectic alloy was substantially undercooled and containerlessly solidified by an electromagnetic levitator and a drop tube. The dependence of the peritectic solidification mode on undercooling was established based on the results of the solidified microstructures, crystal growth velocity, as well as X-ray diffraction patterns. Below a critical undercooling of 124 K, the primary Ni7Zr2 phase preferentially nucleates and grows from the undercooled liquid, which is followed by a peritectic reaction of Ni7Zr2+L → Ni5Zr. The corresponding microstructure is composed of the Ni7Zr2 dendrites, peritectic Ni5Zr phase, and inter-dendritic eutectic. Nevertheless, once the liquid undercooling exceeds the critical undercooling, the peritectic Ni5Zr phase directly precipitates from this undercooled liquid. However, a negligible amount of residual Ni7Zr2 phase still appears in the microstructure, indicating that nucleation and growth of the Ni7Zr2 phase are not completely suppressed. The micromechanical property of the peritectic Ni5Zr phase in terms of the Vickers microhardness is enhanced, which is ascribed to the transition of the peritectic solidification mode. To suppress the formation of the primary phase completely, this alloy was also containerlessly solidified in free fall experiments. Typical peritectic solidified microstructure forms in large droplets, while only the peritectic Ni5Zr phase appears in smaller droplets, which gives an indication that the peritectic Ni5Zr phase directly precipitates from the undercooled liquid by completely suppressing the growth of the primary Ni7Zr2 phase and the peritectic reaction due to the combined effects of the large undercooling and high cooling rate.

Adaptation to high throughput batch chromatography enhances multivariate screening.

Science.gov (United States)

Barker, Gregory A; Calzada, Joseph; Herzer, Sibylle; Rieble, Siegfried

2015-09-01

High throughput process development offers unique approaches to explore complex process design spaces with relatively low material consumption. Batch chromatography is one technique that can be used to screen chromatographic conditions in a 96-well plate. Typical batch chromatography workflows examine variations in buffer conditions or comparison of multiple resins in a given process, as opposed to the assessment of protein loading conditions in combination with other factors. A modification to the batch chromatography paradigm is described here where experimental planning, programming, and a staggered loading approach increase the multivariate space that can be explored with a liquid handling system. The iterative batch chromatography (IBC) approach is described, which treats every well in a 96-well plate as an individual experiment, wherein protein loading conditions can be varied alongside other factors such as wash and elution buffer conditions. As all of these factors are explored in the same experiment, the interactions between them are characterized and the number of follow-up confirmatory experiments is reduced. This in turn improves statistical power and throughput. Two examples of the IBC method are shown and the impact of the load conditions are assessed in combination with the other factors explored. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Model Integrasi Penjadwalan Produksi Batch dan Penjadwalan Perawatan dengan Kendala Due Date

Directory of Open Access Journals (Sweden)

Zahedi .

2014-01-01

Full Text Available This paper discusses the integration model of batch production and preventive maintenance scheduling on a single machine producing an item to be delivered at a common due date. The machine is a deteriorating machine that requires preventive maintenance to ensure the availability of the machine at a desired service level. Decision variables of the model are the number of preventive maintenances, the schedule, length of production runs, as well as the number of batches, batch sizes and the production schedule of the resulting batches for each production run. The objective function of the model is to minimize the total cost consisting of inventory costs during parts processing, setup cost and cost of preventive maintenance. The results show three important points: First, the sequence of optimal batches always follows the SPT (short processing time. Second, variation of preventive maintenance unit cost does not influence the sequence of batches. Third, the first production run length from production starting time is smaller than the next production run length and this pattern continues until the due date. When in process inventory unit cost is increased, the pattern will continue until a specified cost limit, and beyond the limit the pattern will change to be the opposite pattern.

PENENTUAN PRODUCTION LOT SIZES DAN TRANSFER BATCH SIZES DENGAN PENDEKATAN MULTISTAGE

Directory of Open Access Journals (Sweden)

Purnawan Adi W

2012-02-01

Full Text Available Pengendalian dan perawatan inventori merupakan suatu permasalahan yang sering dihadapi seluruh organisasi dalam berbagai sektor ekonomi. Salah satu tantangan yang yang harus dihadapi dalam pengendalian inventori adalah bagaimana menentukan ukuran lot yang optimal pada suatu sistem produksi dengan berbagai tipe. Analisis batch produksi (production lot dengan pendekatan hybrid simulasi analitik merupakan salah satu penelitian mengenai ukuran lot optimal. Penelitian tersebut menggunakan pendekatan sistem singlestage dimana tidak adanya hubungan antar proses di setiap stage atau dengan kata lain, proses yang satu independen terhadap proses yang lain. Dengan menggunakan objek penelitian yang sama dengan objek penelitian diatas, penelitian ini kemudian mengangkat permasalahan penentuan ukuran production lot dengan pendekatan multistage. Pertama, dengan menggunakan data-data yang sama dengan penelitian sebelumnya ditentukan ukuran production lot yang optimal dengan metode programa linier. Selanjutnya ukuran production lot digunakan sebegai input simulasi untuk menentukan ukuran transfer batch. Rata-rata panjang antrian dan waktu tunggu menjadi ukuran performansi yang digunakan sebagai acuan penentuan ukuran transfer batch dari beberapa alternatif ukuran yang ada. Pada penelitian ini, ukuran production lot yang dihasilkan sama besarnya dengan demand tiap periode. Sedangkan untuk ukuran transfer batch, hasil penentuan dengan menggunakan simulasi kemudian dimplementasikan ke dalam model. Hasilnya adalah adanya penurunan inventori yang terjadi sebesar 76,35% untuk produk connector dan 50,59% untuk produk box connector dari inventori yang dihasilkan dengan pendekatan singlestage. Kata kunci : multistage, production lot, transfer batch     Abstract   Inventory maintenance and inventory control is a problem that often faced by all organization in many economic sectors. One of challenges that must be faced in inventory control is how to determine the

Comparing Social Stories™ to Cool versus Not Cool

Science.gov (United States)

Leaf, Justin B.; Mitchell, Erin; Townley-Cochran, Donna; McEachin, John; Taubman, Mitchell; Leaf, Ronald

2016-01-01

In this study we compared the cool versus not cool procedure to Social Stories™ for teaching various social behaviors to one individual diagnosed with autism spectrum disorder. The researchers randomly assigned three social skills to the cool versus not cool procedure and three social skills to the Social Stories™ procedure. Naturalistic probes…

An adaptive crystal bender for high power synchrotron radiation beams

International Nuclear Information System (INIS)

Berman, L.E.; Hastings, J.B.

1992-01-01

Perfect crystal monochromators cannot diffract x-rays efficiently, nor transmit the high source brightness available at synchrotron radiation facilities, unless surface strains within the beam footprint are maintained within a few arcseconds. Insertion devices at existing synchrotron sources already produce x-ray power density levels that can induce surface slope errors of several arcseconds on silicon monochromator crystals at room temperature, no matter how well the crystal is cooled. The power density levels that will be produced by insertion devices at the third-generation sources will be as much as a factor of 100 higher still. One method of restoring ideal x-ray diffraction behavior, while coping with high power levels, involves adaptive compensation of the induced thermal strain field. The design and performance, using the X25 hybrid wiggler beam line at the National Synchrotron Light Source (NSLS), of a silicon crystal bender constructed for this purpose are described

The Feasibility of Bulk Crystallization as an Industrial Purification and Production Technique for Proteins

Science.gov (United States)

Judge, Russell A.; Forsythe, Elizabeth L.; Johns, Michael R.; Pusey, Marc L.; White, Edward T.

1998-01-01

Bulk crystallization in stirred vessels is used industrially for the recovery and purification of many inorganic and organic materials. Although much has been written on the crystallization of proteins for X-ray diffraction analysis, very little has been reported on the application of bulk crystallization in stirred vessels. In this study, a 1-liter, seeded, stirred, batch crystallizer was used with ovalbumin as a model protein to test the feasibility of this crystallization method as a recovery and purification process for proteins. Results were obtained for ovalbumin solubility, nucleation thresholds, crystal breakage and crystal growth kinetics in bulk solution under a range of operating conditions of pH and ammonium sulphate concentration (Judge et al., 1996). Experiments were also performed to determine the degree of purification that can be achieved by the crystallization of ovalbumin from a mixture of proteins. The effect of the presence of these proteins upon the ovalbumin crystal growth kinetics was also investigated (Judge et al., 1995). All of these aspects are essential for the design of bulk crystallization processes which have not previously been reported for proteins. Results from a second study that investigated the effect of structurally different proteins on the solubility, crystal growth rates and crystal purity of chicken egg white lysozyme are also presented (Judge et al., 1997). In this case face growth rates were measured using lysozyme purified by liquid chromatography and the effect of the addition of specific protein impurities were observed on the (110) and (101) crystal faces. In these two studies the results are presented to show the feasibility and purifying ability of crystallization as a production process for proteins.

Pollution prevention applications in batch manufacturing operations

Science.gov (United States)

Sykes, Derek W.; O'Shaughnessy, James

2004-02-01

Older, "low-tech" batch manufacturing operations are often fertile grounds for gains resulting from pollution prevention techniques. This paper presents a pollution prevention technique utilized for wastewater discharge permit compliance purposes at a batch manufacturer of detergents, deodorants, and floor-care products. This manufacturer generated industrial wastewater as a result of equipment rinses required after each product batch changeover. After investing a significant amount of capital on end of pip-line wastewater treatment technology designed to address existing discharge limits, this manufacturer chose to investigate alternate, low-cost approaches to address anticipated new permit limits. Mass balances using spreadsheets and readily available formulation and production data were conducted on over 300 products to determine how each individual product contributed to the total wastewater pollutant load. These mass balances indicated that 22 products accounted for over 55% of the wastewater pollutant. Laboratory tests were conducted to determine whether these same products could accept their individual changeover rinse water as make-up water in formulations without sacrificing product quality. This changeover reuse technique was then implement at the plant scale for selected products. Significant reductions in wastewater volume (25%) and wastewater pollutant loading (85+%) were realized as a direct result of this approach.

Film cooling for a closed loop cooled airfoil

Science.gov (United States)

Burdgick, Steven Sebastian; Yu, Yufeng Phillip; Itzel, Gary Michael

2003-01-01

Turbine stator vane segments have radially inner and outer walls with vanes extending therebetween. The inner and outer walls are compartmentalized and have impingement plates. Steam flowing into the outer wall plenum passes through the impingement plate for impingement cooling of the outer wall upper surface. The spent impingement steam flows into cavities of the vane having inserts for impingement cooling the walls of the vane. The steam passes into the inner wall and through the impingement plate for impingement cooling of the inner wall surface and for return through return cavities having inserts for impingement cooling of the vane surfaces. At least one film cooling hole is defined through a wall of at least one of the cavities for flow communication between an interior of the cavity and an exterior of the vane. The film cooling hole(s) are defined adjacent a potential low LCF life region, so that cooling medium that bleeds out through the film cooling hole(s) reduces a thermal gradient in a vicinity thereof, thereby the increase the LCF life of that region.

Air-cooled LiBr-water absorption chillers for solar air conditioning in extremely hot weathers

International Nuclear Information System (INIS)

Kim, D.S.; Infante Ferreira, C.A.

2009-01-01

A low temperature-driven absorption cycle is theoretically investigated for the development of an air-cooled LiBr-water absorption chiller to be combined with low-cost flat solar collectors for solar air conditioning in hot and dry regions. The cycle works with dilute LiBr-water solutions so that risk of LiBr crystallization is less than for commercially available water-cooled LiBr-water absorption chillers even in extremely hot ambient conditions. Two-phase heat exchangers in the system were modelled taking account of the heat and mass transfer resistances in falling film flows by applying the film theory in thermal and concentration boundary layers. Both directly and indirectly air-cooled chillers were modelled by properly combining component models and boundary conditions in a matrix system and solved with an algebraic equation solver. Simulation results predict that the chillers would deliver chilled water around 7.0 deg. C with a COP of 0.37 from 90 deg. C hot water under 35 deg. C ambient condition. At 50 deg. C ambient temperature, the chillers retained about 36% of their cooling power at 35 deg. C ambient. Compared with the directly air-cooled chiller, the indirectly air-cooled chiller presented a cooling power performance reduction of about 30%

Synthesis, growth, morphology and characterization of ferroelectric glycine phosphite single crystals

Energy Technology Data Exchange (ETDEWEB)

Devi, K. Renuka; Srinivasan, K. [Crystal Growth Laboratory, Department of Physics, School of Physical Sciences, Bharathiar University, Tamil Nadu (India)

2011-12-15

Glycine phosphite (NH{sub 3}CH{sub 2}COO.H{sub 3}PO{sub 3}), a potential ferroelectric material, was grown as single crystals from aqueous solutions by slow evaporation and slow cooling methods. Laboratory synthesized title compound was purified by recrystallization method and confirmed by Fourier transform infrared and Laser Raman studies. Temperature dependent solubility in double distilled water in the range between 288 and 328 K was determined by gravimetric method. Morphological importance of various growth faces were studied by optical goniometry. Powder x-ray diffraction study performed on the grown crystals confirms the crystal system and lattice parameters of the unit cell. Optical transparency of the grown crystals in the ultraviolet-visible -near infrared region was studied by spectroscopic method. Thermal stability of the grown crystals in the temperature region above ambient until melting was studied using differential scanning calorimetry. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Analysis of mercerization process based on the intensity change of deconvoluted resonances of 13C CP/MAS NMR: Cellulose mercerized under cooling and non-cooling conditions

International Nuclear Information System (INIS)

Miura, Kento; Nakano, Takato

2015-01-01

The area intensity change of C1, C4, and C6 in spectrum obtained by 13 C CP/MAS NMR and the mutual relationship between their changes were examined for cellulose samples treated with various concentrations of aqueous NaOH solutions under non-cooling and cooling conditions. The area intensity of C1-up and C6-down changed cooperatively with that of C4-down which corresponds to the crystallinity of samples: “-up” and “-down” are the up- and down- field component in a splitting peak of NMR spectrum, respectively. The intensity change of C1-up starts to decrease with decreasing in that of C4-down after that of C6-down is almost complete. These changes were more clearly observed for samples treated under cooling condition. It can be suggested that their characteristic change relates closely to the change in conformation of cellulose chains by induced decrystallization and the subsequent crystallization of cellulose II, and presumed that their changes at microscopic level relate to the macroscopic morphological changes such as contraction along the length of cellulose chains and recovery along the length. - Highlight: • Samples were mercerized at various NaOH concentrations under non-cooling and cooling. • The intensity change of C1 starts immediately after that of C6 is complete. • The creation of cell-II starts when decrystallization proceeds to a certain state. • This change relates closely to the change in conformation of cellulose chains. • The above change is more clearly found for samples treated under cooling

Retardation characteristics of radionuclides in geologic media through batch and packed column experiments

International Nuclear Information System (INIS)

Park, Hun Hwee; Han, Kyung Won; Han, Pil Soo; Lee, Jae Owan; Park, Chung Kyun; Yang, Ho Yeon

1988-03-01

Batch and packed column experiments are performed to investigate the retardation characteristics of radionuclide,i.e, Cs-137 in geologic media. In batch experiment, the effects of important parameters on the sorption of radionuclide in geologic media, such as nuclide concentration, pH, and particle size are examined. The Kd value obtained from breakthrough curve was compared with that from the batch sorption experiment to investigate the applicability of the Kd value from batch experiment to prediction of radionuclide migration in dynamic flow through porous media. The proposed model of radionuclide migration in porous media is also verified using the experimental results. (Author)

Nucleation and crystallization of new glasses from fly ash originating from thermal power plants

Energy Technology Data Exchange (ETDEWEB)

Barbieri, L.; Lancellotti, I.; Manfredini, T.; Pellacani, G.C.; Rincon, J.M.; Romero, M. [University of Modena & Reggio Emilia, Modena (Italy). Faculty of Engineering, Dept. of Chemistry

2001-08-01

The nucleation and crystallization kinetics of new glasses obtained by melting mixtures of a Spanish carbon fly ash with glass cullet and dolomite slag at 1500{degree}C has been evaluated by a calculation method. These glasses, whose microstructure was examined by TEM carbon replica, were susceptible to controlled crystallization in the 800{degree} -1100{degree}C range. The resulting glass-ceramics developed acicular and branched wollastonite crystals or a network of dendritic pyroxene mixed with anorthite feldspar (SEM and EDX analysis). The time-temperature-transformation curves (processing of the XRD data) showed the crystallization kinetics and the critical cooling rate to be in the 12{degree} -42{degree}C/min range.

Modelisation and numerical simulation for bulk crystal growth processes

International Nuclear Information System (INIS)

Duffar, F.; Dusserre, P.; Barat, C.; Nabot, J.P.

1993-01-01

The aim of this work is to study the relevance of numerical simulation for improving the process control in the field of crystal growth. This investigation focused on the growth of semiconductor and halide crystals by the Bridgman solidification technique, the principle of which is to cool a seeded feed material contained in a crucible, either by pulling the crucible or by decreasing the temperature in the furnace. Calculations are performed with the finite element method, and for comparison, experiments are carried out on Bridgman pulling machines operating either in a laboratory or in industrial plants. Calculations and experimental data have shown a good agreement and a satisfactory reliability

Lubricating and Waxy Esters. VI. Effect of Symmetry about Ester on Crystallization of Linear Monoester Isomers

Directory of Open Access Journals (Sweden)

Laziz Bouzidi

2014-08-01

Full Text Available The crystal structure development of jojoba-like esters incorporating either 1-decenoic acid and/or 1-decenol, namely octadec-9-enyl dec-9-enoate (JLE-281, and its isomer dec-9-enyl oleate (JLE-282 was investigated to reveal the effect of symmetry about the ester group on crystallization of aliphatic fatty monoesters. The phase transformation path was investigated with temperature-time resolved X-ray diffraction during stepped isothermal crystallization, and while cooling from the melt at a fixed rate. Startling differences in phase behavior were uncovered between the isomers. When stepped isothermals were used, selective extinctions occurred at a transition temperature for JLE-281 but not for JLE-282. The extinctions, which are due to dramatic changes in the electronic density of certain families of planes, indicate a phase transition attributed to a brusque rearrangement of the oxygen atoms in the crystal subcell. The phase transition did not occur when the JLEs were cooled continuously. The crucial role played by the position of the alkyl chain and its orientation relative to the easy rotation site of the C–O bond in the phase trajectories of the JLEs was particularly highlighted.

Vibrational, calorimetric and nonlinear optical studies of melaminium-bis(trichloroacetate) monohydrate molecular ionic crystal

Science.gov (United States)

Debrus, S.; Marchewka, M. K.; Drozd, M.; Ratajczak, H.

2007-04-01

The efficiency of second harmonic generation for melaminium bis(trichloroacetate) was estimated relatively to KDP: deff = 3.09 deff (KDP). Room temperature FT IR and FT Raman spectra were recorded. Some spectral features of this new crystal are referred to corresponding one for melamine crystal as well as for other trichloroacetates. Differential scanning calorimetric measurements performed on powder sample indicate the phase transition point at approximately 276 and 239 K for heating and cooling, respectively.

Divertor cooling device

International Nuclear Information System (INIS)

Nakayama, Tadakazu; Hayashi, Katsumi; Handa, Hiroyuki

1993-01-01

Cooling water for a divertor cooling system cools the divertor, thereafter, passes through pipelines connecting the exit pipelines of the divertor cooling system and the inlet pipelines of a blanket cooling system and is introduced to the blanket cooling system in a vacuum vessel. It undergoes emission of neutrons, and cooling water in the divertor cooling system containing a great amount of N-16 which is generated by radioactivation of O-16 is introduced to the blanket cooling system in the vacuum vessel by way of pipelines, and after cooling, passes through exit pipelines of the blanket cooling system and is introduced to the outside of the vacuum vessel. Radiation of N-16 in the cooling water is decayed sufficiently with passage of time during cooling of the blanket, thereby enabling to decrease the amount of shielding materials such as facilities and pipelines, and ensure spaces. (N.H.)

Anti-solvent co-crystallization of carbamazepine and saccharin.

Science.gov (United States)

Wang, In-Chun; Lee, Min-Jeong; Sim, Sang-Jun; Kim, Woo-Sik; Chun, Nan-Hee; Choi, Guang J

2013-06-25

The co-crystal approach has been investigated extensively over the past decade as one of the most promising methods to enhance the dissolution properties of insoluble drug substances. Co-crystal powders are typically produced by mechanical grinding (neat or wet) or a solution method (evaporation or cooling). In this study, high-purity carbamazepine-saccharin (CBZ-SAC) co-crystals were manufactured by a novel method, anti-solvent addition. Among various solvents, methanol was found to perform well with water as the anti-solvent for the co-crystallization of CBZ and SAC. When water was added to the methanol solution of CBZ and SAC at room temperature under agitation, nucleation of CBZ-SAC co-crystals occurred within 2-3 min. Co-crystallization was complete after 30 min, giving a solid yield as high as 84.5% on a CBZ basis. The effects of initial concentrations, focusing on the SAC/CBZ ratio, were examined to establish optimal conditions. The whole anti-solvent co-crystallization process was monitored at-line via ATR-FTIR analysis of regularly sampled solutions. The nucleation and crystal growth of CBZ-SAC co-crystals were detected by a significant increase in absorption in the range of 2400-2260 cm(-1), associated with the formation of hydrogen bonds between the carbonyl group in CBZ and the N-H of SAC. When CBZ hydrates were formed as impurities during anti-solvent co-crystallization, the hydrogen bonding between methanol and water was reduced greatly, primarily due to the incorporation of water molecules into the CBZ crystal lattice. In conclusion, an anti-solvent approach can be used to produce highly pure CBZ-SAC co-crystal powders with a high solid yield. Copyright © 2013 Elsevier B.V. All rights reserved.

Cool colored coating and phase change materials as complementary cooling strategies for building cooling load reduction in tropics

International Nuclear Information System (INIS)

Lei, Jiawei; Kumarasamy, Karthikeyan; Zingre, Kishor T.; Yang, Jinglei; Wan, Man Pun; Yang, En-Hua

2017-01-01

Highlights: • Cool colored coating and PCM are two complementary passive cooling strategies. • A PCM cool colored coating system is developed. • The coating reduces cooling energy by 8.5% and is effective yearly in tropical Singapore. - Abstract: Cool colored coating and phase change materials (PCM) are two passive cooling strategies often used separately in many studies and applications. This paper investigated the integration of cool colored coating and PCM for building cooling through experimental and numerical studies. Results showed that cool colored coating and PCM are two complementary passive cooling strategies that could be used concurrently in tropical climate where cool colored coating in the form of paint serves as the “first protection” to reflect solar radiation and a thin layer of PCM forms the “second protection” to absorb the conductive heat that cannot be handled by cool paint. Unlike other climate zones where PCM is only seasonally effective and cool paint is only beneficial during summer, the application of the proposed PCM cool colored coating in building envelope could be effective throughout the entire year with a monthly cooling energy saving ranging from 5 to 12% due to the uniform climatic condition all year round in tropical Singapore.

Optimal operation of batch membrane processes

CERN Document Server

Paulen, Radoslav

2016-01-01

This study concentrates on a general optimization of a particular class of membrane separation processes: those involving batch diafiltration. Existing practices are explained and operational improvements based on optimal control theory are suggested. The first part of the book introduces the theory of membrane processes, optimal control and dynamic optimization. Separation problems are defined and mathematical models of batch membrane processes derived. The control theory focuses on problems of dynamic optimization from a chemical-engineering point of view. Analytical and numerical methods that can be exploited to treat problems of optimal control for membrane processes are described. The second part of the text builds on this theoretical basis to establish solutions for membrane models of increasing complexity. Each chapter starts with a derivation of optimal operation and continues with case studies exemplifying various aspects of the control problems under consideration. The authors work their way from th...

Thermoelectric self-cooling for power electronics: Increasing the cooling power

International Nuclear Information System (INIS)

Martinez, Alvaro; Astrain, David; Aranguren, Patricia

2016-01-01

Thermoelectric self-cooling was firstly conceived to increase, without electricity consumption, the cooling power of passive cooling systems. This paper studies the combination of heat pipe exchangers and thermoelectric self-cooling, and demonstrates its applicability to the cooling of power electronics. Experimental tests indicate that source-to-ambient thermal resistance reduces by around 30% when thermoelectric self-cooling system is installed, compared to that of the heat pipe exchanger under natural convection. Neither additional electric power nor cooling fluids are required. This thermal resistance reaches 0.346 K/W for a heat flux of 24.1 kW/m"2, being one order of magnitude lower than that obtained in previous designs. In addition, the system adapts to the cooling demand, reducing this thermal resistance for increasing heat. Simulation tests have indicated that simple system modifications allow relevant improvements in the cooling power. Replacement of a thermoelectric module with a thermal bridge leads to 33.54 kW/m"2 of top cooling power. Likewise, thermoelectric modules with shorter legs and higher number of pairs lead to a top cooling power of 44.17 kW/m"2. These results demonstrate the applicability of thermoelectric self-cooling to power electronics. - Highlights: • Cooling power of passive systems increased. • No electric power consumption. • Applicable for the cooling of power electronics. • Up to 44.17 kW/m"2 of cooling power, one order of magnitude higher. • Source-to-ambient thermal resistance reduces by 30%.

Cryogenically cooled monochromators for the Advanced Photon Source

International Nuclear Information System (INIS)

Mills, D.M.

1996-01-01

The use of cryogenically cooled monochromators looks to be a very promising possibility for the Advanced Photon Source. This position has recently been bolstered by several experiments performed on beamlines at the ESRF and CHESS. At the ESRF, several crystal geometries have been tested that were designed for high power densities (approx-gt 150 W/mm 2 ) and moderate total absorbed powers (<200 W). These geometries have proven to be very successful at handling these power parameters with measured strains on the arc-second level. The experiments performed at CHESS were focused on high total power (approx-gt 1000 W) but moderate power densities. As with the previously mentioned experiments, the crystals designed for this application performed superbly with no measurable broadening of the rocking curves on the arc-second level. These experiments will be summarized and, based on these results, the performance of cryogenic monochromators for the APS will be assessed. copyright 1996 American Institute of Physics

Application of gain scheduling to the control of batch bioreactors

Science.gov (United States)

Cardello, Ralph; San, Ka-Yiu

1987-01-01

The implementation of control algorithms to batch bioreactors is often complicated by the inherent variations in process dynamics during the course of fermentation. Such a wide operating range may render the performance of fixed gain PID controllers unsatisfactory. In this work, a detailed study on the control of batch fermentation is performed. Furthermore, a simple batch controller design is proposed which incorporates the concept of gain-scheduling, a subclass of adaptive control, with oxygen uptake rate as an auxiliary variable. The control of oxygen tension in the biorector is used as a vehicle to convey the proposed idea, analysis and results. Simulation experiments indicate significant improvement in controller performance can be achieved by the proposed approach even in the presence of measurement noise.

Enhanced Electrical Resistivity after Rapid Cool of the Specimen in Layered Oxide LixCoO2

Science.gov (United States)

Miyoshi, K.; Manami, K.; Takeuchi, J.; Sasai, R.; Nishigori, S.

Measurements of electrical resistivity and DC magnetization for LixCoO2 (x=0.71 and 0.64) have been performed using single crystal specimens. It has been found that electrical resistivity measured after rapid cool of the specimen becomes larger compared with that after slow cool below the temperature TS∽155 K at which charge ordering of Co3+/Co4+(=2:1) occurs. The behavior can be understood considering that the charge ordering can be destroyed by Li ions which are in an amorphous state after rapid cool via the interlayer Coulomb interactions, and also that the disordered Co3+/Co4+ state becomes insulating, while the charge ordered state has a metallic electronic structure, as recently revealed by the scanning tunneling microscopy.

Thermodynamic performance analysis of gas-fired air-cooled adiabatic absorption refrigeration systems

International Nuclear Information System (INIS)

Wang, L.; Chen, G.M.; Wang, Q.; Zhong, M.

2007-01-01

In China, the application of small size gas-fired air-cooled absorption refrigeration systems as an alternative for electric compression air conditioning systems has shown broad prospects due to occurrence of electricity peak demand in Chinese big cities and lack of water resources. However, for conventional air-cooled absorption refrigeration systems, it is difficult to enhance the heat and mass transfer process in the falling film absorber, and may cause problems, for example, remarkable increase of pressure, temperature and concentration in the generators, risk of crystallization, acceleration of corrosion, degradation of performance, and so on. This paper presents a gas-fired air-cooled adiabatic absorption refrigeration system using lithium bromide-water solutions as its working fluid, which is designed with a cooling capacity of 16 kW under standard conditions. The system has two new features of waste heat recovery of condensed water from generator and an adiabatic absorber with an air cooler. Performance simulation and characteristic analysis are crucial for the optimal control and reliability of operation in extremely hot climates. A methodology is presented to simulate thermodynamic performance of the system. The influences of outdoor air temperature on operation performances of the system are investigated

Effects of the rate of supersaturation generation on polymorphic crystallization of m-hydroxybenzoic acid and o-aminobenzoic acid

Science.gov (United States)

He, Guangwen; Wong, Annie B. H.; Chow, Pui Shan; Tan, Reginald B. H.

2011-01-01

Effects of the rate of supersaturation generation on polymorphic crystallization have been investigated through evaporation and cooling crystallization experiments of m-hydroxybenzoic acid (m-HBA) in methanol, acetone and ethyl acetate, and o-aminobenzoic acid (o-ABA) in ethanol. The rate of supersaturation generation has been altered by systematically changing either the cooling rate or the evaporation rate of solvent using a jacketed crystallizer and a microfluidic evaporation device, respectively. The results have revealed that the rate of supersaturation generation and the tendency of the formation of the less stable polymorph are positively correlated. Kinetic effects are dominant when the rate of supersaturation generation is high, thereby producing the metastable polymorphs (orthorhombic m-HBA; Form II of o-ABA); on the contrary, more stable polymorphs (monoclinic m-HBA; Forms III and I of o-ABA) are formed when the rate of supersaturation generation is low and the thermodynamic effects are prevailing.

Vortex bending in a tilted YBa2Cu3O7-δ crystal

Science.gov (United States)

Obaidat, I. M.; Park, S. J.; Safar, H.; Kouvel, J. S.

1997-09-01

Magnetization-vector measurements were made on a YBa2Cu3O7-δ crystal, initially cooled to 4.2 K in an external field He parallel to the c axis. With He fixed, the crystal was then tilted, such that the angle θ between the c axis and He was gradually raised to 90° and lowered back to zero. Our results reveal that all the vortex flux remains parallel to the c axis until the tilt angle θ reaches a threshold value (close to 15° for Hevalue, the vortex flux in the ab plane rises rapidly from zero, and it appears to derive solely from a bending of the vortices initially directed along c. This whole process is fairly consistent with theoretical predictions, and it is found to be essentially reversible with the cycling of θ at low He. The hysteresis that develops at higher He rises and approaches the conventional hysteresis measured along ab after zero-field cooling. Comparison is also made with a cross-flux experiment, which is seen to be only superficially equivalent to the crystal-tilt experiment.

Look-ahead strategies for controlling batch operations in industry : basic insights in rule construction

NARCIS (Netherlands)

van der Zee, D.J.; Sullivan, W.A.; Ahmad, M.M.; Fichtner, D.; Sauer, W.; Weigert, G.; Zerna, T.

2002-01-01

Batching jobs in a manufacturing system is a very common policy in most industries. Main reasons for batching are avoidance of set ups and/or facilitation of material handling. Examples of batch-wise production systems are ovens found in aircraft industry and in semiconductor manufacturing. Starting

Control of polymer network topology in semi-batch systems

Science.gov (United States)

Wang, Rui; Olsen, Bradley; Johnson, Jeremiah

Polymer networks invariably possess topological defects: loops of different orders. Since small loops (primary loops and secondary loops) both lower the modulus of network and lead to stress concentration that causes material failure at low deformation, it is desirable to greatly reduce the loop fraction. We have shown that achieving loop fraction close to zero is extremely difficult in the batch process due to the slow decay of loop fraction with the polymer concentration and chain length. Here, we develop a modified kinetic graph theory that can model network formation reactions in semi-batch systems. We demonstrate that the loop fraction is not sensitive to the feeding policy if the reaction volume maintains constant during the network formation. However, if we initially put concentrated solution of small junction molecules in the reactor and continuously adding polymer solutions, the fractions of both primary loop and higher-order loops will be significantly reduced. There is a limiting value (nonzero) of loop fraction that can be achieved in the semi-batch system in condition of extremely slow feeding rate. This minimum loop fraction only depends on a single dimensionless variable, the product of concentration and with single chain pervaded volume, and defines an operating zone in which the loop fraction of polymer networks can be controlled through adjusting the feeding rate of the semi-batch process.

Monitoring of batch processes using spectroscopy

NARCIS (Netherlands)

Gurden, S. P.; Westerhuis, J. A.; Smilde, A. K.

2002-01-01

There is an increasing need for new techniques for the understanding, monitoring and the control of batch processes. Spectroscopy is now becoming established as a means of obtaining real-time, high-quality chemical information at frequent time intervals and across a wide range of industrial

In-situ Crystallization of Highly Volatile Commercial Mold Flux Using an Isolated Observation System in the Confocal Laser Scanning Microscope

Science.gov (United States)

Park, Jun-Yong; Ryu, Jae Wook; Sohn, Il

2014-08-01

The in situ crystallization behavior of highly volatile commercial mold fluxes for medium carbon steels was investigated using the confocal laser scanning microscope (CLSM) equipped with an optimized isolated observation system. The highly volatile compounds of the mold flux were suppressed during heating allowing direct observation in the CLSM. Cooling rates of 25, 50, 100, 400, and 800 K/min were incorporated and continuous cooling transformation (CCT) diagrams of 4 different commercial mold fluxes for medium carbon steels were developed. Identification of the crystalline phase was conducted with XRD and SEM-EDS analysis. A cuspidine crystalline was observed in all samples at various cooling rates. With higher basicity, CaF2, and NaF, the crystallization of the fluxes was enhanced according to the CCT diagram. As the slag structure becomes depolymerized, the diffusion rate of the cathodic ions seems to increase.

Development of longer Nd:LGGG crystal for high power laser application

Science.gov (United States)

Yin, Yanru; Tian, Hanlin; Zhang, Jian; Mu, Wenxiang; Zhang, Baitao; Jia, Zhitai; He, Jingliang; Tao, Xutang

2017-11-01

In order to further improve the Nd3+:(LuxGd1-x)3Ga5O12 (Nd:LGGG) crystal performance in high power laser field, a long Nd:LGGG crystal with dimensions of Φ 23 × 112 mm3 has been grown successfully by the Czochralski (Cz) method for laser rod fabrication. Compared with the normal size LGGG crystals (like 30-50 mm in length), we overcame several difficulties in the growth of longer ones, including crystal cracking by a large longitudinal temperature gradient, spiral growth by a small radial temperature gradient, and growth instability and even constitutional super cooling by Ga2O3 volatilizing continuously. The doping concentrations of Nd3+ and Lu3+ in the as-grown crystal and the crystal optical quality have been measured. The performance of diode-side-pumped Nd:LGGG rod laser has been preliminarily tested for the first time, simply by replacing the Nd:YAG crystal rod inside a commercial laser module. Under an incident pump power of 160 W, the maximum continuous wave output power of 38 W has been obtained, corresponding to an optical-optical conversion efficiency of 23.8% and a slope efficiency of 40.8%, respectively.

Production of tea vinegar by batch and semicontinuous fermentation

OpenAIRE

Kaur, Pardeep; Kocher, G. S.; Phutela, R. P.

2010-01-01

The fermented tea vinegar combines the beneficial properties of tea and vinegar. The complete fermentation takes 4 to 5 weeks in a batch culture and thus can be shortened by semi continuous/ continuous fermentation using immobilized bacterial cells. In the present study, alcoholic fermentation of 1.0 and 1.5% tea infusions using Saccharomyces cerevisae G was carried out that resulted in 84.3 and 84.8% fermentation efficiency (FE) respectively. The batch vinegar fermentation of these wines wit...

Kinetic modeling of multi‐component crystallization of industrial‐grade oils and fats

DEFF Research Database (Denmark)

Hjorth, Jeppe L.; Miller, Rasmus L.; Woodley, John M.

2015-01-01

Transient crystallization kinetics is investigated for complex, industrial‐grade vegetable oils consisting of more than ten triacylglycerols (TAG). The classical nucleation model has been used to describe primary nucleation, while secondary nucleation has been described by a semi‐empirical approach......‐fat content (SFC) measurements for a given oil at different cooling rates and degrees of dilution. The developed model can accommodate more polymorphs simultaneously and performs well with respect to predicting crystallization onset, rate of crystallization and final SFC value. It can also qualitatively...... compositions. Such a predictive model may provide a powerful tool to screen and optimize oil formulations in industrial processes and allow product developers to evaluate recrystallization events....

Analysis of mercerization process based on the intensity change of deconvoluted resonances of {sup 13}C CP/MAS NMR: Cellulose mercerized under cooling and non-cooling conditions

Energy Technology Data Exchange (ETDEWEB)

Miura, Kento [Mitsubishi Rayon Co., Ltd. Otake Research Laboratories (Japan); Nakano, Takato, E-mail: tnakano@kais.kyoto-u.ac.jp [Laboratory of Biomaterials Design, Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University (Japan)

2015-08-01

The area intensity change of C1, C4, and C6 in spectrum obtained by {sup 13}C CP/MAS NMR and the mutual relationship between their changes were examined for cellulose samples treated with various concentrations of aqueous NaOH solutions under non-cooling and cooling conditions. The area intensity of C1-up and C6-down changed cooperatively with that of C4-down which corresponds to the crystallinity of samples: “-up” and “-down” are the up- and down- field component in a splitting peak of NMR spectrum, respectively. The intensity change of C1-up starts to decrease with decreasing in that of C4-down after that of C6-down is almost complete. These changes were more clearly observed for samples treated under cooling condition. It can be suggested that their characteristic change relates closely to the change in conformation of cellulose chains by induced decrystallization and the subsequent crystallization of cellulose II, and presumed that their changes at microscopic level relate to the macroscopic morphological changes such as contraction along the length of cellulose chains and recovery along the length. - Highlight: • Samples were mercerized at various NaOH concentrations under non-cooling and cooling. • The intensity change of C1 starts immediately after that of C6 is complete. • The creation of cell-II starts when decrystallization proceeds to a certain state. • This change relates closely to the change in conformation of cellulose chains. • The above change is more clearly found for samples treated under cooling.

Anisotropic ultrasound propagation in a smectic-C liquid crystal

International Nuclear Information System (INIS)

Bhattacharya, S.; Umrigar, C.J.; Ketterson, J.B.

1976-01-01

The results of longitudinal ultrasound propagation in a magnetically aligned smectic-C liquid crystal (p-p' Heptyloxyazoxy benzene) are reported. In the smectic-C phase the plane normals can lie anywhere on a cone with the axis along the magnetic field direction in which the sample was cooled. The effects of the layer normal direction and the molecular orientation within the planes on the velocity anisotropy were separated by cooling the sample into the smectic-C phase at particular orientations of the magnetic field and subsequently rotating the magnetic field. The results were analyzed on the basis of a multidomain model where the azimuthal angle of the plane normal around the field direction was averaged over

Ethanol production from Sorghum bicolor using both separate and simultaneous saccharification and fermentation in batch and fed batch systems

DEFF Research Database (Denmark)

Mehmood, Sajid; Gulfraz, M.; Rana, N. F.

2009-01-01

The objective of this work was to find the best combination of different experimental conditions during pre-treatment, enzymatic saccharification, detoxification of inhibitors and fermentation of Sorghum bicolor straw for ethanol production. The optimization of pre-treatment using different...... were used in order to increase the monomeric sugar during enzymatic hydrolysis and it has been observed that the addition of these surfactants contributed significantly in cellulosic conversion but no effect was shown on hemicellulosic hydrolysis. Fermentability of hydrolyzate was tested using...... Saccharomyces cerevisiae Ethanol Red (TM) and it was observed that simultaneous saccharification and fermentation ( SSF) with both batch and fed batch resulted in better ethanol yield as compared to separate hydrolysis and fermentation ( SHF). Detoxification of furan during SHF facilitated reduction...

Semiconducting icosahedral boron arsenide crystal growth for neutron detection

Science.gov (United States)

Whiteley, C. E.; Zhang, Y.; Gong, Y.; Bakalova, S.; Mayo, A.; Edgar, J. H.; Kuball, M.

2011-03-01

Semiconducting icosahedral boron arsenide, B12As2, is an excellent candidate for neutron detectors, thermoelectric converters, and radioisotope batteries, for which high quality single crystals are required. Thus, the present study was undertaken to grow B12As2 crystals by precipitation from metal solutions (nickel) saturated with elemental boron (or B12As2 powder) and arsenic in a sealed quartz ampoule. B12As2 crystals of 10-15 mm were produced when a homogeneous mixture of the three elements was held at 1150 °C for 48-72 h and slowly cooled (3.5 °C/h). The crystals varied in color and transparency from black and opaque to clear and transparent. X-ray topography (XRT), and elemental analysis by energy dispersive X-ray spectroscopy (EDS) confirmed that the crystals had the expected rhombohedral structure and chemical stoichiometry. The concentrations of residual impurities (nickel, carbon, etc.) were low, as measured by Raman spectroscopy and secondary ion mass spectrometry (SIMS). Additionally, low etch-pit densities (4.4×107 cm-2) were observed after etching in molten KOH at 500 °C. Thus, the flux growth method is viable for growing large, high-quality B12As2 crystals.

Growth of NH4Cl Single Crystal from Vapor Phase in Vertical Furnace

Science.gov (United States)

Nigara, Yutaka; Yoshizawa, Masahito; Fujimura, Tadao

1983-02-01

A pure and internally stress-free single crystal of NH4Cl was grown successfully from the vapor phase. The crystal measured 1.6 cmφ× 2 cm and had the disordered CsCl structure, which was stable below 184°C. The crystal was grown in an ampoule in a vertical furnace, in which the vapor was efficiently transported both by diffusion and convection. In line with the growth mechanism of a single crystal, the temperature fluctuation (°C/min) on the growth interface was kept smaller than the product of the temperature gradient (°C/cm) and the growth rate (cm/min). The specific heat of the crystal was measured around -31°C (242 K) during cooling and heating cycles by AC calorimetry. The thermal hysteresis (0.4 K) obtained here was smaller than that (0.89 K) of an NH4Cl crystal grown from its aqueous solution with urea added as a habit modifier.

Three-batch reloading scheme for IRIS reactor extended cycles

International Nuclear Information System (INIS)

Jecmenica, R.; Pevec, D.; Grgic, D.

2004-01-01

To fully exploit the IRIS reactor optimized maintenance, and at the same time improve fuel utilization, a core design enabling a 4-year operating cycle together with a three-batch reloading scheme is desirable. However, this requires not only the increased allowed burnup but also use of fuel with uranium oxide enriched beyond 5%. This paper considers three-batch reloading scheme for a 4-year operating cycle with the assumptions of increased discharge burnup and fuel enrichment beyond 5%. Calculational model of IRIS reactor core has been developed based on FER FA2D code for group constants generation and NRC's PARCS nodal code for global core analysis. Studies have been performed resulting in a preliminary design of a three-batch core configuration for the first cycle. It must be emphasized that this study is outside the current IRIS licensing efforts, which rely on the present fuel technology (enrichment below 5%), but it is of long-term interest for potential future IRIS design upgrades. (author)

Thermal History of CBb Chondrules and Cooling Rate Distributions of Ejecta Plumes

Science.gov (United States)

Hewins, R. H.; Condie, C.; Morris, M.; Richardson, M. L. A.; Ouellette, N.; Metcalf, M.

2018-03-01

It has been proposed that some meteorites, CB and CH chondrites, contain material formed as a result of a protoplanetary collision during accretion. Their melt droplets (chondrules) and FeNi metal are proposed to have formed by evaporation and condensation in the resulting impact plume. We observe that the skeletal olivine (SO) chondrules in CBb chondrites have a blebby texture and an enrichment in refractory elements not found in normal chondrules. Because the texture requires complete melting, their maximum liquidus temperature of 1928 K represents a minimum temperature for the putative plume. Dynamic crystallization experiments show that the SO texture can be created only by brief reheating episodes during crystallization, giving a partial dissolution of olivine. The ejecta plume formed in a smoothed particle hydrodynamics simulation served as the basis for 3D modeling with the adaptive mesh refinement code FLASH4.3. Tracer particles that move with the fluid cells are used to measure the in situ cooling rates. Their cooling rates are ∼10,000 K hr‑1 briefly at peak temperature and, in the densest regions of the plume, ∼100 K hr‑1 for 1400–1600 K. A small fraction of cells is seen to be heating at any one time, with heating spikes explained by the compression of parcels of gas in a heterogeneous patchy plume. These temperature fluctuations are comparable to those required in crystallization experiments. For the first time, we find an agreement between experiments and models that supports the plume model specifically for the formation of CBb chondrules.

Results on testing pilot industrial batch of SC magnets for the UNK

International Nuclear Information System (INIS)

Ageev, A.I.; Andreev, N.I.; Balbekov, V.I.; Chirkov, P.N.; Dolzhenkov, V.I.; Gertsev, K.F.; Gridasov, V.I.; Myznikov, K.P.; Smirnov, N.L.; Sychev, V.A.

1992-01-01

IHEP has developed and studied the superconducting dipoles and quadrupoles of the regular part of the UNK main ring which satisfy the requirements imposed on them. The pilot-industrial batch of the UNK SC magnets has been produced now. The reproducibility of the magnet characteristics is studied and the mass production technology is optimized with this batch. The results of the cryogenic tests and the magnetic field measurements for the UNK SC dipoles of the pilot-industrial batch are presented. (author) 5 refs.; 6 figs.; 1 tab