WorldWideScience

Sample records for ferrofluid drying process

  1. PREFACE: Ferrofluids

    Odenbach, Professor Stefan

    2006-09-01

    suspensions with properties clearly focused towards the need of the application. While such tailoring of fluids to certain well defined properties sounds like a straightforward approach one has to face the fact that it requires a clear definition of the required properties. This definition itself has to be based on a fundamental physical knowledge of the processes determining certain magnetically controlled phenomena in ferrofluids. To make this point concrete one can look into the detailed aims of the mentioned research program. The application areas identified for the future development of research and application of suspensions of magnetic nanoparticles have been on the one hand the biomedical application—especially with respect to cancer treatment—and on the other hand the use of magnetically controlled rheological properties of ferrofluids for new active technical devices. Both directions require, as mentioned, as a basis for success the synthesis of new ferrofluids with dedicated properties. While the medical applications have to rely on biocompatibility as well as on stability of the suspensions in a biomedical environment, the use of ferrofluids in technical devices employing their magnetically controlled rheological properties will depend on an enhancement of the changes of the fluid's viscous properties in the presence of moderate magnetic fields. For both requirements ferrofluids with a make up clearly different from the usual magnetite based fluids have to be synthesized. The question of how the detailed microscopic make up of the fluids would have to look has to be answered on the basis of basic research results defining the physics background of the respective phenomena. Taking these aspects together it becomes obvious that the aforementioned research program had goals aiming far beyond the state of the art of classical ferrofluid research. These goals as well as the basic strategy to achieve them is in a way reflected by the structure of this issue of

  2. Dry process potentials

    Faugeras, P.

    1997-01-01

    Various dry processes have been studied and more or less developed in order particularly to reduce the waste quantities but none of them had replaced the PUREX process, for reasons departing to policy errors, un-appropriate demonstration examples or too late development, although realistic and efficient dry processes such as a fluoride selective volatility based processes have been demonstrated in France (CLOVIS, ATILA) and would be ten times cheaper than the PUREX process. Dry processes could regain interest in case of a nuclear revival (following global warming fears) or thermal wastes over-production. In the near future, dry processes could be introduced in complement to the PUREX process, especially at the end of the process cycle, for a more efficient recycling and safer storage (inactivation)

  3. Magnetic detection of ferrofluid injection zones

    Borglin, S.; Moridis, G.; Becker, A.

    1998-03-01

    Ferrofluids are stable colloidal suspensions of magnetic particles that can be stabilized in various carrier liquids. In this study the authors investigate the potential of ferrofluids to trace the movement and position of liquids injected in the subsurface using geophysical methods. An ability to track and monitor the movement and position of injected liquids is essential in assessing the effectiveness of the delivery system and the success of the process. Ferrofluids can also provide a significant detection and verification tool in containment technologies, where they can be injected with the barrier liquids to provide a strong signature allowing determination of the barrier geometry, extent, continuity and integrity. Finally, ferrofluids may have unique properties as tracers for detecting preferential flow features (such as fractures) in the subsurface, and thus allow the design of more effective remediation systems. In this report the authors review the results of the investigation of the potential of ferrofluids to trace the movement and position of liquids injected in the subsurface using geophysical methods. They demonstrate the feasibility of using conventional magnetometry for detecting subsurface zones of injected ferrofluids used to trace liquids injected for remediation or barrier formation. The geometrical shapes considered were a sphere, a thin disk, a rectangular horizontal slab, and a cylinder. Simple calculations based on the principles of magnetometry are made to determine the detection depths of FTs. Experiments involving spherical, cylindrical and horizontal slabs show a very good agreement between predictions and measurements.

  4. Air dehumidification and drying processes

    Steiner, R.

    1988-07-01

    Details are given on the physical principles of air dehumidification and drying as well as on appropriate systems available on the market. Reference is made to dehumidification through condensation (intermittent compressor or electric auxiliary heater defrosting, reversible-circuit hot gas bypass defrosting), air drying through sorption (sorbents, regeneration through heat inputs), the operation of absorptive dryers (schematic sketches), and the change of state of air (Mollier h,x-diagramm). Practical examples refer to the dehumidification of storage rooms, archives, and waterworks as well as to air drying in the pharmaceutical industry, the pastry and candy industry, the food industry, and the drying (preservation) of turbines and generators during long standstill periods. A diagramm shows that while adsorption processes are efficient at temperatures below 80/sup 0/C, low-temperature dehumidification is efficient at temperatures above. (HWJ).

  5. Spray Drying Processing: granules production and drying kinetics of droplets

    Mondragon, R.; Julia, J. E.; Barba, A.; Jarque, J. C.

    2013-01-01

    Spray drying is a unit operation very common in many industrial processes. For each particular application, the resulting granulated material must possess determined properties that depend on the conditions in which the spray drying processing has been carried out, and whose dependence must be known in order to optimize the quality of the material obtained. The large number of variables that influence on the processes of matter and energy transfer and on the formation of granular material has required a detailed analysis of the drying process. Over the years there have been many studies on the spray drying processing of all kind of materials and the influence of process variables on the drying kinetics of the granulated material properties obtained. This article lists the most important works published for both the spray drying processing and the drying of individual droplets, as well as studies aimed at modeling the drying kinetics of drops. (Author)

  6. Capillary viscosimetry on ferrofluids

    Pop, L M; Odenbach, S

    2008-01-01

    Experiments performed for different ferrofluids under shear flow have shown that an increase of the magnetic field strength applied to the sample yields an increase of the fluid's viscosity, the so called magnetoviscous effect. It has been shown that the magnitude of the effect is strongly related to the modification of the microstructure of ferrofluids and can be influenced by varying both the dipole-dipole interaction between the particles and the concentration of large particles within the fluid. This result has been further used to synthesize new ferrofluids which, on one hand, are more compatible for technical applications but, on the other hand, led to difficulties for the experimenters in measuring the viscous behavior in the presence of a magnetic field. To overcome this problem, a specially designed ferrofluid-compatible capillary viscometer has been developed. Within this paper, the experimental setup as well as experimental results concerning the investigation of the magnetoviscous effect in both diluted and concentrated cobalt-based ferrofluids are presented

  7. Modelling of a free-surface ferrofluid flow

    Habera, M., E-mail: habera@karlin.mff.cuni.cz; Hron, J., E-mail: hron@karlin.mff.cuni.cz

    2017-06-01

    The Cauchy's stress tensor of a ferrofluid exposed to an external magnetic field is subject to additional magnetic terms. For a linearly magnetizable medium, the terms result in interfacial magnetic force acting on the ferrofluid boundaries. This force changes the characteristics of many free-surface ferrofluid phenomena. The aim of this work is to implement this force into the incompressible Navier-Stokes equations and propose a numerical method to solve them. The interface of ferrofluid is tracked with the use of the characteristic level-set method and additional reinitialization step assures conservation of its volume. Incompressible Navier-Stokes equations are formulated for a divergence-free velocity fields while discrete interfacial forces are treated with continuous surface force model. Velocity-pressure coupling is implemented via the projection method. To predict the magnetic force effect quantitatively, Maxwell's equations for magnetostatics are solved in each time step. Finite element method is utilized for the spatial discretization. At the end of the work, equilibrium droplet shape are compared to known experimental results. - Highlights: • Incompressible Navier-Stokes equations are formulated for the problem of free-surface ferrofluid flow. • Computed equilibrium ferrofluid droplet shape is compared to known experimental result. • Magnetic field substantially changes the dynamics of ferrofluid dripping process.

  8. Analysis of Drying Process Quality in Conventional Dry-Kilns

    Sedlar Tomislav; Pervan Stjepan

    2010-01-01

    This paper presents testing results of drying quality in a conventional dry kiln. Testing is based on a new methodology that will show the level of success of the drying process management by analyzing the quality of drying process in a conventional dry kiln, using a scientifi cally improved version of the check list in everyday practical applications. A company that specializes in lamel and classic parquet production was chosen so as to verify the new testing methodology. A total of 56 m3 of...

  9. The dynamics analysis of a ferrofluid shock absorber

    Yao, Jie; Chang, Jianjun; Li, Decai; Yang, Xiaolong

    2016-01-01

    The paper presents a shock absorber using three magnets as the inertial mass. Movement of the inertial mass inside a cylindrical body filled with ferrofluid will lead to a viscous dissipation of the oscillating system energy. The influence of a dumbbell-like ferrofluid structure on the energy dissipation is considered and the magnetic restoring force is investigated by experiment and theoretical calculation. A theoretical model of the hydrodynamics and energy dissipation processes is developed, which includes the geometrical characteristics of the body, the fluid viscosity, and the external magnetic field. The theory predicts the experimental results well under some condition. The shock absorber can be used in spacecraft technology. - Highlights: • We study a ferrofluid shock absorber. • The mechanical model of the flow of the ferrofluid has been built. • The theoretical model of the energy dissipation processes is developed. • The magnetic restoring force between the body and the magnets has been measured.

  10. The dynamics analysis of a ferrofluid shock absorber

    Yao, Jie; Chang, Jianjun [School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Li, Decai, E-mail: dcli@bjtu.edu.cn [School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Yang, Xiaolong [School of Mechanical Engineering, Guangxi University of Science and Technology, Liuzhou, Guangxi 545006 (China)

    2016-03-15

    The paper presents a shock absorber using three magnets as the inertial mass. Movement of the inertial mass inside a cylindrical body filled with ferrofluid will lead to a viscous dissipation of the oscillating system energy. The influence of a dumbbell-like ferrofluid structure on the energy dissipation is considered and the magnetic restoring force is investigated by experiment and theoretical calculation. A theoretical model of the hydrodynamics and energy dissipation processes is developed, which includes the geometrical characteristics of the body, the fluid viscosity, and the external magnetic field. The theory predicts the experimental results well under some condition. The shock absorber can be used in spacecraft technology. - Highlights: • We study a ferrofluid shock absorber. • The mechanical model of the flow of the ferrofluid has been built. • The theoretical model of the energy dissipation processes is developed. • The magnetic restoring force between the body and the magnets has been measured.

  11. FREEZE DRYING PROCESS: A REVIEW

    Soham Shukla

    2011-01-01

    Among the various methods of drying, this article has mentioned only one most important method, “Freeze drying”. This method is mainly used for the drying of thermo labile materials. This method works on the principle of sublimation. This method is divided into 3 steps for its better understanding; these are Freezing, Primary drying, and secondary drying. There are many advantages and disadvantages of this method, but still this is the most useful drying method nowadays.

  12. Inert carrier drying and coating process

    1980-01-01

    An inert carrier process is described for drying radioactive (particularly low level) waste material and for incorporating the dry material into a binder matrix from which the dried material will not be leached. Experimental details, and examples of the carrier and binder materials, are given. (U.K.)

  13. Spray drying for processing of nanomaterials

    Lindeloev, Jesper Saederup; Wahlberg, Michael

    2009-01-01

    Consolidation of nano-particles into micron-sized granules reduces the potential risks associated with handling nano-powders in dry form. Spray drying is a one step granulation technique which can be designed for safe production of free flowing low dusty granules from suspensions of nano-particles. Spray dried granules are well suited for subsequent processing into final products where the superior properties given by the nano-particles are retained. A spray drier with bag filters inside the drying chamber and recycling of drying gas combined with containment valves are proposed as a safe process for granulation of potential hazardous nano-particles.

  14. Extrusion processing : effects on dry canine diets

    Tran, Q.D.

    2008-01-01

    Keywords: Extrusion, Canine diet, Protein, Lysine, Starch gelatinization, Palatability, Drying.

    Extrusion cooking is a useful and economical tool for processing animal feed. This high temperature, short time processing technology causes chemical and physical changes that alter the

  15. FINAL REPORT: Transformational electrode drying process

    Claus Daniel, C.; Wixom, M.(A123 Systems, Inc.)

    2013-12-19

    This report includes major findings and outlook from the transformational electrode drying project performance period from January 6, 2012 to August 1, 2012. Electrode drying before cell assembly is an operational bottleneck in battery manufacturing due to long drying times and batch processing. Water taken up during shipment and other manufacturing steps needs to be removed before final battery assembly. Conventional vacuum ovens are limited in drying speed due to a temperature threshold needed to avoid damaging polymer components in the composite electrode. Roll to roll operation and alternative treatments can increase the water desorption and removal rate without overheating and damaging other components in the composite electrode, thus considerably reducing drying time and energy use. The objective of this project was the development of an electrode drying procedure, and the demonstration of processes with no decrease in battery performance. The benchmark for all drying data was an 80°C vacuum furnace treatment with a residence time of 18 – 22 hours. This report demonstrates an alternative roll to roll drying process with a 500-fold improvement in drying time down to 2 minutes and consumption of only 30% of the energy compared to vacuum furnace treatment.

  16. Transient magnetoviscosity of dilute ferrofluids

    Soto-Aquino, Denisse; Rinaldi, Carlos

    2011-01-01

    The magnetic field induced change in the viscosity of a ferrofluid, commonly known as the magnetoviscous effect and parameterized through the magnetoviscosity, is one of the most interesting and practically relevant aspects of ferrofluid phenomena. Although the steady state behavior of ferrofluids under conditions of applied constant magnetic fields has received considerable attention, comparatively little attention has been given to the transient response of the magnetoviscosity to changes in the applied magnetic field or rate of shear deformation. Such transient response can provide further insight into the dynamics of ferrofluids and find practical application in the design of devices that take advantage of the magnetoviscous effect and inevitably must deal with changes in the applied magnetic field and deformation. In this contribution Brownian dynamics simulations and a simple model based on the ferrohydrodynamics equations are applied to explore the dependence of the transient magnetoviscosity for two cases: (I) a ferrofluid in a constant shear flow wherein the magnetic field is suddenly turned on, and (II) a ferrofluid in a constant magnetic field wherein the shear flow is suddenly started. Both simulations and analysis show that the transient approach to a steady state magnetoviscosity can be either monotonic or oscillatory depending on the relative magnitudes of the applied magnetic field and shear rate. - Research Highlights: →Rotational Brownian dynamics simulations were used to study the transient behavior of the magnetoviscosity of ferrofluids. →Damped and oscillatory approach to steady state magnetoviscosity was observed for step changes in shear rate and magnetic field. →A model based on the ferrohydrodynamics equations qualitatively captured the damped and oscillatory features of the transient response →The transient behavior is due to the interplay of hydrodynamic, magnetic, and Brownian torques on the suspended particles.

  17. Numerical simulation on ferrofluid flow in fractured porous media based on discrete-fracture model

    Huang, Tao; Yao, Jun; Huang, Zhaoqin; Yin, Xiaolong; Xie, Haojun; Zhang, Jianguang

    2017-06-01

    Water flooding is an efficient approach to maintain reservoir pressure and has been widely used to enhance oil recovery. However, preferential water pathways such as fractures can significantly decrease the sweep efficiency. Therefore, the utilization ratio of injected water is seriously affected. How to develop new flooding technology to further improve the oil recovery in this situation is a pressing problem. For the past few years, controllable ferrofluid has caused the extensive concern in oil industry as a new functional material. In the presence of a gradient in the magnetic field strength, a magnetic body force is produced on the ferrofluid so that the attractive magnetic forces allow the ferrofluid to be manipulated to flow in any desired direction through the control of the external magnetic field. In view of these properties, the potential application of using the ferrofluid as a new kind of displacing fluid for flooding in fractured porous media is been studied in this paper for the first time. Considering the physical process of the mobilization of ferrofluid through porous media by arrangement of strong external magnetic fields, the magnetic body force was introduced into the Darcy equation and deals with fractures based on the discrete-fracture model. The fully implicit finite volume method is used to solve mathematical model and the validity and accuracy of numerical simulation, which is demonstrated through an experiment with ferrofluid flowing in a single fractured oil-saturated sand in a 2-D horizontal cell. At last, the water flooding and ferrofluid flooding in a complex fractured porous media have been studied. The results showed that the ferrofluid can be manipulated to flow in desired direction through control of the external magnetic field, so that using ferrofluid for flooding can raise the scope of the whole displacement. As a consequence, the oil recovery has been greatly improved in comparison to water flooding. Thus, the ferrofluid

  18. Cooking and drying processes optimization of Pentadesma ...

    Aghomotsegin

    2015-09-30

    Sep 30, 2015 ... This work determined the optimum conditions of cooking and drying processes. ... Key words: Forest galeries, Pentadesma butyraceae, cosmetic industry, ..... butyracea kernels can lead to the production of butter of.

  19. Radioactive Dry Process Material Treatment Technology Development

    Park, J. J.; Hung, I. H.; Kim, K. K. (and others)

    2007-06-15

    The project 'Radioactive Dry Process Material Treatment Technology Development' aims to be normal operation for the experiments at DUPIC fuel development facility (DFDF) and safe operation of the facility through the technology developments such as remote operation, maintenance and pair of the facility, treatment of various high level process wastes and trapping of volatile process gases. DUPIC Fuel Development Facility (DFDF) can accommodate highly active nuclear materials, and now it is for fabrication of the oxide fuel by dry process characterizing the proliferation resistance. During the second stage from march 2005 to February 2007, we carried out technology development of the remote maintenance and the DFDF's safe operation, development of treatment technology for process off-gas, and development of treatment technology for PWR cladding hull and the results was described in this report.

  20. Continuous-flow sheathless diamagnetic particle separation in ferrofluids

    Zhou, Yilong; Song, Le; Yu, Liandong; Xuan, Xiangchun

    2016-01-01

    Separating particles from a complex mixture is often necessary in many chemical and biomedical applications. This work presents a continuous-flow sheathless diamagnetic particle separation in ferrofluids through U-shaped microchannels. Due to the action of a size-dependent magnetic force, diamagnetic particles are focused into a single stream in the inlet branch of the U-turn and then continuously separated into two streams in its outlet branch. A 3D numerical model is developed to predict and understand the diamagnetic particle transport during this separation process. The numerical predictions are found to agree well with the experimental observations in a systematic study of the effects of multiple parameters including ferrofluid flow rate, concentration and magnet-channel distance. Additional numerical studies of the geometric effects of the U-turn reveal that increasing the outlet-branch width of the U-turn can significantly enhance the diamagnetic particle separation in ferrofluids. - Highlights: • Particles are focused and separated in the two branches of a U-shaped microchannel. • Negative magnetophoretic motion in ferrofluids causes the particle deflection. • A 3D numerical model is developed to simulate the particle separation. • Multiple parametric effects are studied both experimentally and numerically. • Increasing the outlet-branch width significantly enhances the particle separation.

  1. Continuous-flow sheathless diamagnetic particle separation in ferrofluids

    Zhou, Yilong [Department of Mechanical Engineering, Clemson University, Clemson, SC 29634-0921 (United States); Song, Le [School of Instrument Science and Opto-electronic Engineering, Hefei University of Technology, Hefei 230009 (China); Yu, Liandong, E-mail: liandongyu@hfut.edu.cn [School of Instrument Science and Opto-electronic Engineering, Hefei University of Technology, Hefei 230009 (China); Xuan, Xiangchun, E-mail: xcxuan@clemson.edu [Department of Mechanical Engineering, Clemson University, Clemson, SC 29634-0921 (United States)

    2016-08-15

    Separating particles from a complex mixture is often necessary in many chemical and biomedical applications. This work presents a continuous-flow sheathless diamagnetic particle separation in ferrofluids through U-shaped microchannels. Due to the action of a size-dependent magnetic force, diamagnetic particles are focused into a single stream in the inlet branch of the U-turn and then continuously separated into two streams in its outlet branch. A 3D numerical model is developed to predict and understand the diamagnetic particle transport during this separation process. The numerical predictions are found to agree well with the experimental observations in a systematic study of the effects of multiple parameters including ferrofluid flow rate, concentration and magnet-channel distance. Additional numerical studies of the geometric effects of the U-turn reveal that increasing the outlet-branch width of the U-turn can significantly enhance the diamagnetic particle separation in ferrofluids. - Highlights: • Particles are focused and separated in the two branches of a U-shaped microchannel. • Negative magnetophoretic motion in ferrofluids causes the particle deflection. • A 3D numerical model is developed to simulate the particle separation. • Multiple parametric effects are studied both experimentally and numerically. • Increasing the outlet-branch width significantly enhances the particle separation.

  2. Effects of Interfacial Translation-rotation Coupling for Confined Ferrofluids

    Fang, Angbo

    2011-03-01

    Ferrofluids have wide applications ranging from semiconductor fabrications to biomedical processes. The hydrodynamic spin diffusion theory for ferrofluids has been successful in explaining many experimental data, but it suffers from some fatal flaws. For example, it fails to predict the incorrect flow direction for a ferrofluid confined in a concentric cylinder channel in the presence of a rotating magnetic field. In this work we develop a method to establish the general hydrodynamic boundary conditions (BCs) for micro-polar fluids such as ferrofluids. Through a dynamic generalization of the mesoscopic diffuse interface model, we are able to obtain the surface dissipation functional, in which the interfacial translation-rotation coupling plays a significant role. The generalized hydrodynamic BCs can be obtained straightforwardly by using Onsager's variational approach. The resulted velocity profile and other quantities compares well with the experimental data, strikingly different from traditional theories. The methodology can be applied to study the hydrodynamic behavior of other structured fluids in confined channels or multi-phase flows. The work is supported by a research award made by the King Abdullah University of Science and Technology.

  3. Ferrofluids in liquid crystalline systems

    Figueiredo Neto, A.M.; Liebert, L.

    1989-08-01

    It is a well-known fact that intermediate or mesomorphic phase may exist between the crystalline and the isotropic liquid phases. The symmetry properties of these mesophases are intermediate between those of a crystal and a liquid. In this paper, some aspects of the use of ferrofluids in thermotropic and lyotropic systems are studied both the experimental difficulties as well as the fundamental phypical phenomena involved. (A.C.A.S.) [pt

  4. Evaluation of alternative drying techniques for the earthworm flour processing

    Laura Suárez Hernández

    2016-01-01

    Full Text Available Production of earthworm flour includes several steps, among which the most critical is the drying process due to factors such as time and energ y requirements. In addition, the information available about this process is relquite limited. Thus, this work evaluated four drying techniques likely to be implemented by lombricultores: sun drying, oven drying, drying tunnel and microwave assisted drying. Drying kinetics values were obtained for all drying techniques, and specific parameters as the following were evaluated: drying tray material (stainless and ceramic steel for sun drying, microwave power (30 %, 50 % and 80 % and amount of material to be dried (72 and 100 g for microwave assisted drying, temperature (50, 65, 90 and 100 °C for oven drying, and temperature (50 and 63 °C and air speed (2.9 to 3.6 m/s for tunnel drying. It was determined that the most efficient technique is the drying tunnel, because this allows the combination of heat transfer by conduction and convection, and enables controlling the operating parameters. Finally, nutritional analyzes were performed in samples obtained by each drying technique evaluated. The crude protein content for sun drying, microwave assisted drying, oven drying and tunnel drying were 66.36 %, 67.91 %, 60.35 % and 62.33 % respectively, indicating that the drying method and operating parameters do not significantly affect the crude protein content.

  5. Study of audio speakers containing ferrofluid

    Rosensweig, R E [34 Gloucester Road, Summit, NJ 07901 (United States); Hirota, Y; Tsuda, S [Ferrotec, 1-4-14 Kyobashi, chuo-Ku, Tokyo 104-0031 (Japan); Raj, K [Ferrotec, 33 Constitution Drive, Bedford, NH 03110 (United States)

    2008-05-21

    This work validates a method for increasing the radial restoring force on the voice coil in audio speakers containing ferrofluid. In addition, a study is made of factors influencing splash loss of the ferrofluid due to shock. Ferrohydrodynamic analysis is employed throughout to model behavior, and predictions are compared to experimental data.

  6. OPTIMIZATION OF THE PROCESS OF DRYING THE FILTRATE DISTILLERY DREGS

    A. A. Shevtsov

    2013-01-01

    Full Text Available The interactions of various factors affecting the process of drying the filtrate distillery dregs are investigated. Rational conditions for the process of drying the filtrate distillery dregs in a spray dryer are obtained.

  7. Dry processing versus dense medium processing for preparing thermal coal

    De Korte, GJ

    2013-10-01

    Full Text Available of the final product. The separation efficiency of dry processes is, however, not nearly as good as that of dense medium and, as a result, it is difficult to effectively beneficiate coals with a high near-dense content. The product yield obtained from some raw...

  8. Investigation of near dry EDM compared with wet and dry EDM processes

    Gholipoor, Ahad; Baseri, Hamid; Shabgard, Mohammad Reza

    2015-01-01

    Material removal rate (MRR), tool wear ratio (TWR) and surface roughness (SR) obtained by near-dry EDM process were compared with wet and dry EDM at three levels of discharge energy in drilling of SPK steel. Surface integrity machined by this process was studied and compared with wet and dry EDM processes, by scanning electron microscopy (SEM). The results showed that at high level of discharge energy, wet EDM has the most MRR, TWR and SR, and dry EDM has the least MRR, TWR and SR, while at low discharge energy levels, near-dry EDM process has the most MRR and the least SR. SEM micrographs showed that the quality of surface obtained by near-dry EDM process is better than others and the machined surfaces by near-dry EDM process have lower micro-cracks and craters, relatively.

  9. Investigation of near dry EDM compared with wet and dry EDM processes

    Gholipoor, Ahad [Islamic Azad University of Tabriz, Tabriz (Iran, Islamic Republic of); Baseri, Hamid [Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Shabgard, Mohammad Reza [University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2015-05-15

    Material removal rate (MRR), tool wear ratio (TWR) and surface roughness (SR) obtained by near-dry EDM process were compared with wet and dry EDM at three levels of discharge energy in drilling of SPK steel. Surface integrity machined by this process was studied and compared with wet and dry EDM processes, by scanning electron microscopy (SEM). The results showed that at high level of discharge energy, wet EDM has the most MRR, TWR and SR, and dry EDM has the least MRR, TWR and SR, while at low discharge energy levels, near-dry EDM process has the most MRR and the least SR. SEM micrographs showed that the quality of surface obtained by near-dry EDM process is better than others and the machined surfaces by near-dry EDM process have lower micro-cracks and craters, relatively.

  10. 9 CFR 590.542 - Spray process drying operations.

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Spray process drying operations. 590..., Processing, and Facility Requirements § 590.542 Spray process drying operations. (a) The drying room shall be... interrupted. (1) Spray nozzles, orifices, cores, or whizzers shall be cleaned immediately after cessation of...

  11. Time-dependent scattering of incident light of various wavelengths in ferrofluids under external magnetic field

    Jin, Jingyu; Song, Dongxing; Geng, Jiafeng; Jing, Dengwei

    2018-02-01

    Ferrofluids can exhibit the anisotropic thermodynamic properties under magnetic fields. The dynamic optical properties of ferrofluids in the presence of magnetic fields are of particular interest due to their potential application as various optical devices. Although time-dependent light scattering by ferrofluids have been extensively studied, the effect of wavelength of incident light have been rarely considered. Here, for the first time, we investigated both the time- and wavelength-dependent light scattering in water based ferrofluids containing Fe3O4 nanoparticles under an external magnetic field. The field-induced response behavior of the prepared ferrofluid samples was determined and verified first by thermal conductivity measurement and numerical simulation. Double-beam UV-Vis spectrophotometer was employed to record the temporal evolution of transmitted intensity of incident light of various wavelengths passing through the ferrofluid sample and propagating parallel to the applied field. As expected, the light intensity decreases to a certain value right after the field is turned on due to the thermal fluctuation induced disorder inside the flexible particle chains. Then the light intensity further decreases with time until the appearance of a minimum at time τ0 followed by an inversed increase before finally reaches equilibrium at a particular time. More importantly, the characteristic inversion time τ0 was found to follow a power law increase with the wavelength of incident light (τ0 ∼ λα, where α = 2.07). A quantitative explanation for the wavelength dependence of characteristic time was proposed based on the finite-difference time-domain (FDTD) method. The simulation results are in good agreement with our experimental observations. The time-dependent light scattering in ferrofluids under different incident wavelengths was rationalized by considering both the coarsening process of the particle chains and the occurrence of resonance within the

  12. Ferrofluid-based Stretchable Magnetic Core Inductors

    Lazarus, N.; Meyer, C. D.

    2015-12-01

    Magnetic materials are commonly used in inductor and transformer cores to increase inductance density. The emerging field of stretchable electronics poses a new challenge since typical magnetic cores are bulky, rigid and often brittle. This paper presents, for the first time, stretchable inductors incorporating ferrofluid as a liquid magnetic core. Ferrofluids, suspensions of nanoscale magnetic particles in a carrier liquid, provide enhanced magnetic permeability without changing the mechanical properties of the surrounding elastomer. The inductor tested in this work consisted of a liquid metal solenoid wrapped around a ferrofluid core in separate channels. The low frequency inductance was found to increase from 255 nH before fill to 390 nH after fill with ferrofluid, an increase of 52%. The inductor was also shown to survive uniaxial strains of up to 100%.

  13. Magnetoviscous effect in ferrofluids diluted with sheep blood

    Nowak, J.; Borin, D.; Haefner, S.; Richter, A.; Odenbach, S.

    2017-11-01

    Suspensions of magnetic nanoparticles in suitable carrier liquids, denoted as ferrofluids, are in the focus of current research in the biomedical area. Those fluids can be potentially used for the treatment of cancer by coupling chemotherapeutic agents and accumulating them in the diseased region with the help of external magnetic fields or by artificially local induced heating. Those applications rely on the help of external magnetic fields, which are well known to drastically influence the physical behaviour of ferrofluids. This study investigates the changing viscosity of a biocompatible ferrofluid in a flow situation close to the situation found in a biomedical application. For this purpose blood as diluting agent and thin capillaries have been utilised. The strong magnetoviscous effects found lead to the assumption of quite big changes of the microstructure due to the external magnetic fields, which was investigated and quantified using a microscopic setup. In the result an increases of the structure size as well as faster structure formation in the stronger magnetic fields were observed. Moreover, with increasing duration of the applied magnetic field the size of the structures increases too. The observed process of the structure formation is reversible.

  14. Research experiments on pressure-difference sensors with ferrofluid

    Ruican, Hao, E-mail: haoruican@163.com [School of Mechanical Engineering, Beijing Polytechnic, Beijing 100176 (China); Huagang, Liu; Wen, Gong; Na, Zhang [School of Mechanical Engineering, Beijing Polytechnic, Beijing 100176 (China); Ruixiao, Hao [Civil and Architectural Engineering Institute of CCCC-FHEB Co., Ltd., Beijing 101102 (China)

    2016-10-15

    Ferrofluid has distinctive properties and can be applied in many industrial uses, especially in sensors. The principles of pressure-difference sensors with ferrofluid were illustrated and experiments were demonstrated. Four types of ferrofluids with different concentrations were selected for the experiments performed. Then, the parameters of ferrofluid, such as density and magnetization, were measured. The magnetization curves of the ferrofluid were sketched. Four U tubes with different diameters were designed and built. Experiments were conducted to analyze the impacts of tube diameter and ferrofluid concentration on the output voltage/pressure difference performance. According to the experiment results, the tube diameter has little effect on the sensor output voltage. With the concentration of ferrofluid increasing, the output voltage and sensitivity of the pressure-difference sensor increases. The measurable range of the sensor also increases with the increasing concentration of ferrofluid. The workable range and the sensitivity of the designed sensor were (−2000~+2000)Pa and 1.26 mV/Pa, respectively. - Highlights: • The principle of pressure difference sensor with ferrofluid was illustrated. • The parameters of ferrofluid, such as density and magnetization, were measured. The magnetization curves of the ferrofluid were sketched. • Four series of U tubes with different diameter were designed and manufactured. • The experiments were made to analyze the factors of the tube diameter and the concentration of ferrofluid on the output-input pressure difference. • The sensitivity of the pressure difference sensor with ferrofluid was studied and the corresponding conclusions were obtained.

  15. Research experiments on pressure-difference sensors with ferrofluid

    Ruican, Hao; Huagang, Liu; Wen, Gong; Na, Zhang; Ruixiao, Hao

    2016-01-01

    Ferrofluid has distinctive properties and can be applied in many industrial uses, especially in sensors. The principles of pressure-difference sensors with ferrofluid were illustrated and experiments were demonstrated. Four types of ferrofluids with different concentrations were selected for the experiments performed. Then, the parameters of ferrofluid, such as density and magnetization, were measured. The magnetization curves of the ferrofluid were sketched. Four U tubes with different diameters were designed and built. Experiments were conducted to analyze the impacts of tube diameter and ferrofluid concentration on the output voltage/pressure difference performance. According to the experiment results, the tube diameter has little effect on the sensor output voltage. With the concentration of ferrofluid increasing, the output voltage and sensitivity of the pressure-difference sensor increases. The measurable range of the sensor also increases with the increasing concentration of ferrofluid. The workable range and the sensitivity of the designed sensor were (−2000~+2000)Pa and 1.26 mV/Pa, respectively. - Highlights: • The principle of pressure difference sensor with ferrofluid was illustrated. • The parameters of ferrofluid, such as density and magnetization, were measured. The magnetization curves of the ferrofluid were sketched. • Four series of U tubes with different diameter were designed and manufactured. • The experiments were made to analyze the factors of the tube diameter and the concentration of ferrofluid on the output-input pressure difference. • The sensitivity of the pressure difference sensor with ferrofluid was studied and the corresponding conclusions were obtained.

  16. FERROFLUIDS INFLUENCE ON DEHYDROGENASES ACTIVITY IN CELLULOLYTIC FUNGUS CHAETOMIUM GLOBOSUM

    Alexandru Manoliu

    2003-08-01

    Different results were noticed for different ferrofluids concentrations: 20, 40, 60, 80 and 100 μl/L. Inhibitory or stimulatory ferrofluids effect was obtained depending on the nature of the investigated enzyme.

  17. Drying process strongly affects probiotics viability and functionalities.

    Iaconelli, Cyril; Lemetais, Guillaume; Kechaou, Noura; Chain, Florian; Bermúdez-Humarán, Luis G; Langella, Philippe; Gervais, Patrick; Beney, Laurent

    2015-11-20

    Probiotic formulations are widely used and are proposed to have a variety of beneficial effects, depending on the probiotic strains present in the product. The impact of drying processes on the viability of probiotics is well documented. However, the impact of these processes on probiotics functionality remains unclear. In this work, we investigated variations in seven different bacterial markers after various desiccation processes. Markers were composed of four different viability evaluation (combining two growth abilities and two cytometric measurements) and in three in vitro functionalities: stimulation of IL-10 and IL-12 production by PBMCs (immunomodulation) and bacterial adhesion to hexadecane. We measured the impact of three drying processes (air-drying, freeze-drying and spray-drying), without the use of protective agents, on three types of probiotic bacteria: Bifidobacterium bifidum, Lactobacillus plantarum and Lactobacillus zeae. Our results show that the bacteria respond differently to the three different drying processes, in terms of viability and functionality. Drying methods produce important variations in bacterial immunomodulation and hydrophobicity, which are correlated. We also show that adherence can be stimulated (air-drying) or inhibited (spray-drying) by drying processes. Results of a multivariate analysis show no direct correlation between bacterial survival and functionality, but do show a correlation between probiotic responses to desiccation-rewetting and the process used to dry the bacteria. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Application of pulse combustion technology in spray drying process

    I. Zbicinski

    2000-12-01

    Full Text Available The paper presents development of valved pulse combustor designed for application in drying process and drying tests performed in a specially built installation. Laser technique was applied to investigate the flow field and structure of dispersed phase during pulse combustion spray drying process. PDA technique was used to determine initial atomization parameters as well as particle size distribution, velocity of the particles, mass concentration of liquid phase in the cross section of spray stream, etc., in the drying chamber during drying tests. Water was used to estimate the level of evaporation and 5 and 10% solutions of sodium chloride to carry out drying tests. The Computational Fluid Dynamics technique was used to perform theoretical predictions of time-dependent velocity, temperature distribution and particle trajectories in the drying chamber. Satisfactory agreement between calculations and experimental results was found in certain regions of the drying chamber.

  19. Radiation processing as a post-harvest quarantine control for raisins, dried figs and dried apricots

    Cetinkaya, N.; Ozyardimci, B.; Denli, E.; Ic, E.

    2006-01-01

    The commercially packed samples of raisins, dried figs and dried apricots were irradiated using doses in the range of 0.5-1.0 kGy for disinfestation and 0.5-5.0 kGy for sensory analysis with the dose rate ranging from 1.44 to 1.92 kGy/h. Pests on dried fruits were evaluated after 0, 1, 2 and 3 months of storage for irradiated dried figs and 1, 3, 6 and 12 months of storage for raisins and dried apricots. Sensory analysis of dried figs, dried apricots and raisins were carried out after 0, 1, 3, 6 and 12 months of storage. The results indicated that radiation processing at low doses (∼1.0 kGy) is an effective post-harvest treatment and quarantine control for these products with no adverse effects on sensory (marketing) attributes

  20. Radiation processing as a post-harvest quarantine control for raisins, dried figs and dried apricots

    Cetinkaya, N. [TAEA, Ankara Nuclear Research Center in Agriculture and Animal Sciences, 06983 Ankara (Turkey)]. E-mail: nurcet@taek.gov.tr; Ozyardimci, B. [TAEA, Ankara Nuclear Research Center in Agriculture and Animal Sciences, 06983 Ankara (Turkey); Denli, E. [TAEA, Ankara Nuclear Research Center in Agriculture and Animal Sciences, 06983 Ankara (Turkey); Ic, E. [TAEA, Ankara Nuclear Research Center in Agriculture and Animal Sciences, 06983 Ankara (Turkey)

    2006-03-15

    The commercially packed samples of raisins, dried figs and dried apricots were irradiated using doses in the range of 0.5-1.0 kGy for disinfestation and 0.5-5.0 kGy for sensory analysis with the dose rate ranging from 1.44 to 1.92 kGy/h. Pests on dried fruits were evaluated after 0, 1, 2 and 3 months of storage for irradiated dried figs and 1, 3, 6 and 12 months of storage for raisins and dried apricots. Sensory analysis of dried figs, dried apricots and raisins were carried out after 0, 1, 3, 6 and 12 months of storage. The results indicated that radiation processing at low doses ({approx}1.0 kGy) is an effective post-harvest treatment and quarantine control for these products with no adverse effects on sensory (marketing) attributes.

  1. Usage of Heat Pump Dryer in Food Drying Process and Apple Drying Application

    Gökhan Gürlek

    2015-12-01

    Full Text Available In Turkey, drying is achieved natural method by spreading out the material on the ground. In this way, there are many disadvantages like low quality and hygienic problems. The resulting loss of food quality in the dried products may have effect negatively trade potential and economical worth. For preventing the deterioration of the materials different types of drying methods have been developed. Low energy consumption applications are important for drying industry besides high product quality. For this purpose, heat pump dryer is gaining importance day by day in drying applications. In this study, the working principle of the heat pump dryer, heat pump types in the drying process and the heat pump dryer performance criteria will be considered. An example of application will be described using obtained results from apple drying operation that is conducted in the heat pump dryer.

  2. 9 CFR 590.546 - Albumen flake process drying facilities.

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Albumen flake process drying facilities. 590.546 Section 590.546 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... INSPECTION ACT) Sanitary, Processing, and Facility Requirements § 590.546 Albumen flake process drying...

  3. 9 CFR 590.540 - Spray process drying facilities.

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Spray process drying facilities. 590.540 Section 590.540 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., Processing, and Facility Requirements § 590.540 Spray process drying facilities. (a) Driers shall be of a...

  4. Persistence and survival of pathogens in dry foods and dry food processing environments

    Beuchat, L.; Komitopoulou, E.; Betts, R.; Beckers, H.; Bourdichon, F.; Joosten, H.; Fanning, S.; ter Kuile, B.

    2011-01-01

    Low-moisture foods and food ingredients, i.e., those appearing to be dry or that have been subjected to a drying process, represent important nutritional constituents of human diets. Some of these foods are naturally low in moisture, such as cereals, honey and nuts, whereas others are produced from

  5. Drying characteristics and nitrogen loss of biogas digestate during drying process

    Maurer, C.; Muller, J. [Hohenheim Univ., Stuttgart (Germany). Inst. of Agricultural Engineering, Tropical and Subtropical Group

    2010-07-01

    The cost of transporting biogas digestate can be decreased by reducing its water content. However, the digestate emits volatile compounds during drying. This study investigated the drying behaviour and the change of digestate composition. Drying took place in a hybrid solar/waste-heat dryer that used solar energy as well as waste heat from a combined heat and power unit (CHP) and the exhaust air of a microturbine. The experiment involved the use of 60 t of liquid digestate. Climatic conditions were measured inside and outside the drying hall. Dry matter (DM) and organic dry matter (ODM) were also measured on a daily basis. In addition, the energy consumption of waste and solar heat were recorded and related to the quantity of dried feedstock. The total nitrogen, ammonium, phosphate, potassium oxide, magnesium oxide and calcium oxide in the digestate were subjected to chemical analysis before and after the drying process. Losses of nitrogen were calculated. Specific energy consumption depended on the climatic condition. Most of the energy consumption was covered by the waste heat of the CHP. A considerable amount of nitrogen was lost during the drying process.

  6. Scalable organic solvent free supercritical fluid spray drying process for producing dry protein formulations.

    Nuchuchua, O; Every, H A; Hofland, G W; Jiskoot, W

    2014-11-01

    In this study, we evaluated the influence of supercritical carbon dioxide (scCO2) spray drying conditions, in the absence of organic solvent, on the ability to produce dry protein/trehalose formulations at 1:10 and 1:4 (w/w) ratios. When using a 4L drying vessel, we found that decreasing the solution flow rate and solution volume, or increasing the scCO2 flow rate resulted in a significant reduction in the residual water content in dried products (Karl Fischer titration). The best conditions were then used to evaluate the ability to scale the scCO2 spray drying process from 4L to 10L chamber. The ratio of scCO2 and solution flow rate was kept constant. The products on both scales exhibited similar residual moisture contents, particle morphologies (SEM), and glass transition temperatures (DSC). After reconstitution, the lysozyme activity (enzymatic assay) and structure (circular dichroism, HP-SEC) were fully preserved, but the sub-visible particle content was slightly increased (flow imaging microscopy, nanoparticle tracking analysis). Furthermore, the drying condition was applicable to other proteins resulting in products of similar quality as the lysozyme formulations. In conclusion, we established scCO2 spray drying processing conditions for protein formulations without an organic solvent that holds promise for the industrial production of dry protein formulations. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Development of the vacuum drying process for the PWR spent nuclear fuel dry storage

    Baeg, Chagn Yeal; Cho, Chun Hyung [Korea Radioactive Waste Agency, Daejeon (Korea, Republic of)

    2016-12-15

    This paper describes the development of a dry operation process for PWR spent nuclear fuel, which is currently stored in the domestic NPP's storage pool, using a dual purpose metal cask. Domestic NNPs have had experience with wet type transportation of PWR spent nuclear fuel between neighboring NPPs since the early 1990s, but no experience with dry type operation. For this reason, we developed a specific operation process and also confirmed the safety of the major cask components and its spent nuclear fuel during the dual purpose metal cask operation process. We also describe the short term operation process that was established to be completed within 21 hours and propose the allowable working time for each step (15 hours for wet process, 3 hours for drain process and 3 hours for vacuum drying process)

  8. The influence of lysozyme on mannitol polymorphism in freeze-dried and spray-dried formulations depends on the selection of the drying process

    Grohganz, Holger; Lee, Yan-Ying; Rantanen, Jukka

    2013-01-01

    Freeze-drying and spray-drying are often applied drying techniques for biopharmaceutical formulations. The formation of different solid forms upon drying is often dependent on the complex interplay between excipient selection and process parameters. The purpose of this study was to investigate...... the influence of the chosen drying method on the solid state form. Mannitol-lysozyme solutions of 20mg/mL, with the amount of lysozyme varying between 2.5% and 50% (w/w) of total solid content, were freeze-dried and spray-dried, respectively. The resulting solid state of mannitol was analysed by near......-dried formulations an increase in protein concentration resulted in a shift from ß-mannitol to a-mannitol. An increase in final drying temperature of the freeze-drying process towards the temperature of the spray-drying process did not lead to significant changes. It can thus be concluded that it is the drying...

  9. Characterisation of Aronia powders obtained by different drying processes.

    Horszwald, Anna; Julien, Heritier; Andlauer, Wilfried

    2013-12-01

    Nowadays, food industry is facing challenges connected with the preservation of the highest possible quality of fruit products obtained after processing. Attention has been drawn to Aronia fruits due to numerous health promoting properties of their products. However, processing of Aronia, like other berries, leads to difficulties that stem from the preparation process, as well as changes in the composition of bioactive compounds. Consequently, in this study, Aronia commercial juice was subjected to different drying techniques: spray drying, freeze drying and vacuum drying with the temperature range of 40-80 °C. All powders obtained had a high content of total polyphenols. Powders gained by spray drying had the highest values which corresponded to a high content of total flavonoids, total monomeric anthocyanins, cyaniding-3-glucoside and total proanthocyanidins. Analysis of the results exhibited a correlation between selected bioactive compounds and their antioxidant capacity. In conclusion, drying techniques have an impact on selected quality parameters, and different drying techniques cause changes in the content of bioactives analysed. Spray drying can be recommended for preservation of bioactives in Aronia products. Powder quality depends mainly on the process applied and parameters chosen. Therefore, Aronia powders production should be adapted to the requirements and design of the final product. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. A Process Technology For Conversion Of Dried Cassava Chips Into ...

    “Gari”, made from fermented bitter Cassava roots (Manihot esculenta crantz) were successfully processed from already dried Cassava chips at 7% moisture level. Cassava mash at 67% moisture was prepared from dried Cassava chips. This was seeded severally with fresh cassava mash and fermented for 72hours.

  11. 9 CFR 590.547 - Albumen flake process drying operations.

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Albumen flake process drying operations. 590.547 Section 590.547 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... free of flies, insects, and rodents. (b) Drying units, racks, and trucks shall be kept in a clean and...

  12. The process research of drying UF4 by microwave

    Wen Guo; Wang Yunbo; Liu Long

    2010-01-01

    This paper make use of microwave to dry UF 4 filter cake, the aim is desorbed adsorption water. The research focus on such process conditions, boat material, thickness of filter cake, drying time, setting temperature, heating power and so on. the research of desorption crystal water of UF 4 that dried by microwave in fixed bed .When UF 4 drying by microwave and claiming by fixed bed, the qualified UF 4 powder is prepared. The research is shown that microwave can desorbs adsorption water which contain in UF 4 filter cake. There is a stable water contents in UF 4 after drying, and the sum of two members is less. After drying by microwave and claiming by fixed bed, the contents of water, UO 2 and UO 2 F 2 are all according to the quality standard. (authors)

  13. Infrared pre-drying and dry-dehulling of walnuts for improved processing efficiency and product quality

    The walnut industry is faced with an urgent need to improve post-harvest processing efficiency, particularly drying and dehulling operations. This research investigated the feasibility of dry-dehulling and infrared (IR) pre-drying of walnuts for improved processing efficiency and dried product quali...

  14. Description of saturation curves and boiling process of dry air

    Vestfálová Magda

    2018-01-01

    Full Text Available Air is a mixture of gases forming the gas wrap of Earth. It is formed by dry air, moisture and other pollutants. Dry air is a substance whose thermodynamic properties in gaseous state, as well as the thermodynamic properties of its main constituents in gaseous state, are generally known and described in detail in the literature. The liquid air is a bluish liquid and is industrially used to produce oxygen, nitrogen, argon and helium by distillation. The transition between the gaseous and liquid state (the condensation process, resp. boiling process, is usually displayed in the basic thermodynamic diagrams using the saturation curves. The saturation curves of all pure substances are of a similar shape. However, since the dry air is a mixture, the shapes of its saturation curves are modified relative to the shapes corresponding to the pure substances. This paper deals with the description of the dry air saturation curves as a mixture, i.e. with a description of the process of phase change of dry air (boiling process. The dry air saturation curves are constructed in the basic thermodynamic charts based on the values obtained from the literature. On the basis of diagrams, data appearing in various publications are interpreted and put into context with boiling process of dry air.

  15. Energy and exergy analyses of solar drying process of pistachio

    Midilli, A.; Kucuk, H.

    2003-01-01

    This paper is concerned with the energy and exergy analyses of the drying process of shelled and unshelled pistachios using a solar drying cabinet. Using the first law of thermodynamics, energy analysis was carried to estimate the amounts of energy gained from solar air collectors and the ratios of energy utilization. However, exergy analysis was accomplished to determine the location, type, and magnitude of exergy losses during the solar drying process by applying the second law of thermodynamics. It was deduced that the exergy losses took place mostly in the 15th shelf where the available energy was less utilized. Moreover, the shelled and unshelled pistachios are sufficiently dried in the ranges between 40 and 60 deg. C and 37 and 62% of relative humidity at 1.23 m s -1 of drying air velocity in 6 h despite the exergy losses of 0.15-3.08 kJ kg -1

  16. Energy and exergy analyses of solar drying process of pistachio

    Midilli, A [University of Nigde (Turkey). Dept. of Mechanical Engineering; Kucuk, H [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Mechanical Engineering

    2003-05-01

    This paper is concerned with the energy and exergy analyses of the drying process of shelled and unshelled pistachios using a solar drying cabinet. Using the first law of thermodynamics, energy analysis was carried to estimate the amounts of energy gained from solar air collectors and the ratios of energy utilization. However, exergy analysis was accomplished to determine the location, type, and magnitude of exergy losses during the solar drying process by applying the second law of thermodynamics. It was deduced that the exergy losses took place mostly in the 15th shelf where the available energy was less utilized. Moreover, the shelled and unshelled pistachios are sufficiently dried in the ranges between 40 and 60{sup o}C and 37 and 62% of relative humidity at 1.23 m s{sup -1} of drying air velocity in 6 h despite the exergy losses of 0.15-3.08 kJ kg{sup -1}. (Author)

  17. A novel implantable glaucoma valve using ferrofluid.

    Eleftherios I Paschalis

    Full Text Available PURPOSE: To present a novel design of an implantable glaucoma valve based on ferrofluidic nanoparticles and to compare it with a well-established FDA approved valve. SETTING: Massachusetts Eye & Ear Infirmary, Boston, USA. METHODS: A glaucoma valve was designed using soft lithography techniques utilizing a water-immiscible magnetic fluid (ferrofluid as a pressure-sensitive barrier to aqueous flow. Two rare earth micro magnets were used to calibrate the opening and closing pressure. In-vitro flow measurements were performed to characterize the valve and to compare it to Ahmed™ glaucoma valve. The reliability and predictability of the new valve was verified by pressure/flow measurements over a period of three months and X-ray diffraction (XRD analysis over a period of eight weeks. In vivo assessment was performed in three rabbits. RESULTS: In the in vitro experiments, the opening and closing pressures of the valve were 10 and 7 mmHg, respectively. The measured flow/pressure response was linearly proportional and reproducible over a period of three months (1.8 µl/min at 12 mmHg; 4.3 µl/min at 16 mmHg; 7.6 µl/min at 21 mmHg. X-ray diffraction analysis did not show oxidization of the ferrofluid when exposed to water or air. Preliminary in vivo results suggest that the valve is biocompatible and can control the intraocular pressure in rabbits. CONCLUSIONS: The proposed valve utilizes ferrofluid as passive, tunable constriction element to provide highly predictable opening and closing pressures while maintaining ocular tone. The ferrofluid maintained its magnetic properties in the aqueous environment and provided linear flow to pressure response. Our in-vitro tests showed reliable and reproducible results over a study period of three months. Preliminary in-vivo results were very promising and currently more thorough investigation of this device is underway.

  18. Floating and flying ferrofluid bridges induced by external magnetic fields

    Ma, Rongchao; Zhou, Yixin; Liu, Jing

    2015-04-01

    A ferrofluid is a mixture that exhibits both magnetism and fluidity. This merit enables the ferrofluid to be used in a wide variety of areas. Here we show that a floating ferrofluid bridge can be induced between two separated boards under a balanced external magnetic field generated by two magnets, while a flying ferrofluid bridge can be induced under an unbalanced external magnetic field generated by only one magnet. The mechanisms of the ferrofluid bridges were discussed and the corresponding mathematical equations were also established to describe the interacting magnetic force between the ferro particles inside the ferrofluid. This work answered a basic question that, except for the well-known floating water bridges that are related to electricity, one can also build up a liquid bridge that is related to magnetism.

  19. Heterofermentative process in dry fermented sausages - a case report

    Josef Kameník

    2013-01-01

    Full Text Available In certain circumstances the fermentation process in dry fermented sausages converts to heterofermentation pathway leading to acetic acid and carbon dioxide beside lactic acid. The study describes two cases of undesirable heterofermentation in dry sausages from two different producers. In the sausage samples (n = 7 the pH value and the content of lactic and acetic acids were measured. Microbial analysis focused on quantitative and qualitative detection of lactic acid bacteria. The acetic acid content varied from 24.28 to 67.41 µmol·g-1 dry matter, in the case of samples from the second producer the content of acetic acid (48.45 to 67.41 µmol·g-1 dry matter was higher than the lactic acid content (20.98 to 29.02 µmol·g-1 dry matter. The lactobacilli strains from the sausages were assigned to the corresponding species by Matrix-Assisted Laser Desorption-Ionization – Time of Flight Mass Spectrometry (MALDI-TOF MS and classified to three groups according to the sugar fermentation pattern (obligately homofermentative, facultatively heterofermentative and obligately heterofermentative and they caused the heterofermentation process in the samples of dry fermented sausages. The description of the case of heterofermentation process in dry sausages is unique and there is little information about this topic.

  20. Criticality safety for deactivation of the Rover dry headend process

    Henrikson, D.J.

    1995-01-01

    The Rover dry headend process combusted Rover graphite fuels in preparation for dissolution and solvent extraction for the recovery of 235 U. At the end of the Rover processing campaign, significant quantities of 235 U were left in the dry system. The Rover Dry Headend Process Deactivation Project goal is to remove the remaining uranium bearing material (UBM) from the dry system and then decontaminate the cells. Criticality safety issues associated with the Rover Deactivation Project have been influenced by project design refinement and schedule acceleration initiatives. The uranium ash composition used for calculations must envelope a wide range of material compositions, and yet result in cost effective final packaging and storage. Innovative thinking must be used to provide a timely safety authorization basis while the project design continues to be refined

  1. Analysis on energy consumption of drying process for dried Chinese noodles

    Wang, Zhenhua; Zhang, Yingquan; Zhang, Bo; Yang, Fuguang; Yu, Xiaolei; Zhao, Bo; Wei, Yimin

    2017-01-01

    Highlights: • Energy analysis of a tunnel dryer for dried Chinese noodles is completed. • Energy saving performance of dryers with different inlet air was compared. • MND was developed and evaluated, and the efficiency and throughput was improved. - Abstract: Drying is an important operation during the production of dried Chinese noodles, and the energy consumption from drying accounts for approximately 60% of the total energy consumption during the manufacturing process. To investigate the energy consumption and throughput of dryers for dried Chinese noodles, experiments were conducted using a new 130-m long tunnel dryer with two lines of noodles (ND) and an old 60-m long tunnel dryer with five lines of noodles (OD). The energy saving effects of a modified new 130-m long tunnel dryer (MND), which was only modified through the inclusion of automatic control for temperature and humidity without any modifications to the oil heater or ND dryer structure, were also compared. The energy saving effect was determined from the enthalpy difference between the inlet and outlet humid air of the ND and MND. Finally, the MND was found to be better than ND in terms of energy efficiency and throughput, and trends for the future of noodle drying were discussed.

  2. Dry process fuel performance technology development

    Kang, Kweon Ho; Kim, K. W.; Kim, B. K. (and others)

    2006-06-15

    The objective of the project is to establish the performance evaluation system of DUPIC fuel during the Phase III R and D. In order to fulfil this objectives, property model development of DUPIC fuel and irradiation test was carried out in Hanaro using the instrumented rig. Also, the analysis on the in-reactor behavior analysis of DUPIC fuel, out-pile test using simulated DUPIC fuel as well as performance and integrity assessment in a commercial reactor were performed during this Phase. The R and D results of the Phase III are summarized as follows: Fabrication process establishment of simulated DUPIC fuel for property measurement, Property model development for the DUPIC fuel, Performance evaluation of DUPIC fuel via irradiation test in Hanaro, Post irradiation examination of irradiated fuel and performance analysis, Development of DUPIC fuel performance code (KAOS)

  3. Dry process fuel performance technology development

    Kang, Kweon Ho; Kim, K. W.; Kim, B. K.

    2006-06-01

    The objective of the project is to establish the performance evaluation system of DUPIC fuel during the Phase III R and D. In order to fulfil this objectives, property model development of DUPIC fuel and irradiation test was carried out in Hanaro using the instrumented rig. Also, the analysis on the in-reactor behavior analysis of DUPIC fuel, out-pile test using simulated DUPIC fuel as well as performance and integrity assessment in a commercial reactor were performed during this Phase. The R and D results of the Phase III are summarized as follows: Fabrication process establishment of simulated DUPIC fuel for property measurement, Property model development for the DUPIC fuel, Performance evaluation of DUPIC fuel via irradiation test in Hanaro, Post irradiation examination of irradiated fuel and performance analysis, Development of DUPIC fuel performance code (KAOS)

  4. Modeling of an industrial drying process by artificial neural networks

    E. Assidjo

    2008-09-01

    Full Text Available A suitable method is needed to solve the nonquality problem in the grated coconut industry due to the poor control of product humidity during the process. In this study the possibility of using an artificial neural network (ANN, precisely a Multilayer Perceptron, for modeling the drying step of the production of grated coconut process is highlighted. Drying must confer to the product a final moisture of 3%. Unfortunately, under industrial conditions, this moisture varies from 1.9 to 4.8 %. In order to control this parameter and consequently reduce the proportion of the product that does not meet the humidity specification, a 9-4-1 neural network architecture was established using data gathered from an industrial plant. This Multilayer Perceptron can satisfactorily model the process with less bias, ranging from -0.35 to 0.34%, and can reduce the rate of rejected products from 92% to 3% during the first cycle of drying.

  5. Vortices and vortex lattices in quantum ferrofluids

    Martin, A M; Marchant, N G; Parker, N G; O’Dell, D H J

    2017-01-01

    The experimental realization of quantum-degenerate Bose gases made of atoms with sizeable magnetic dipole moments has created a new type of fluid, known as a quantum ferrofluid, which combines the extraordinary properties of superfluidity and ferrofluidity. A hallmark of superfluids is that they are constrained to rotate through vortices with quantized circulation. In quantum ferrofluids the long-range dipolar interactions add new ingredients by inducing magnetostriction and instabilities, and also affect the structural properties of vortices and vortex lattices. Here we give a review of the theory of vortices in dipolar Bose–Einstein condensates, exploring the interplay of magnetism with vorticity and contrasting this with the established behaviour in non-dipolar condensates. We cover single vortex solutions, including structure, energy and stability, vortex pairs, including interactions and dynamics, and also vortex lattices. Our discussion is founded on the mean-field theory provided by the dipolar Gross–Pitaevskii equation, ranging from analytic treatments based on the Thomas–Fermi (hydrodynamic) and variational approaches to full numerical simulations. Routes for generating vortices in dipolar condensates are discussed, with particular attention paid to rotating condensates, where surface instabilities drive the nucleation of vortices, and lead to the emergence of rich and varied vortex lattice structures. We also present an outlook, including potential extensions to degenerate Fermi gases, quantum Hall physics, toroidal systems and the Berezinskii–Kosterlitz–Thouless transition. (topical review)

  6. Vortices and vortex lattices in quantum ferrofluids

    Martin, A. M.; Marchant, N. G.; O'Dell, D. H. J.; Parker, N. G.

    2017-03-01

    The experimental realization of quantum-degenerate Bose gases made of atoms with sizeable magnetic dipole moments has created a new type of fluid, known as a quantum ferrofluid, which combines the extraordinary properties of superfluidity and ferrofluidity. A hallmark of superfluids is that they are constrained to rotate through vortices with quantized circulation. In quantum ferrofluids the long-range dipolar interactions add new ingredients by inducing magnetostriction and instabilities, and also affect the structural properties of vortices and vortex lattices. Here we give a review of the theory of vortices in dipolar Bose-Einstein condensates, exploring the interplay of magnetism with vorticity and contrasting this with the established behaviour in non-dipolar condensates. We cover single vortex solutions, including structure, energy and stability, vortex pairs, including interactions and dynamics, and also vortex lattices. Our discussion is founded on the mean-field theory provided by the dipolar Gross-Pitaevskii equation, ranging from analytic treatments based on the Thomas-Fermi (hydrodynamic) and variational approaches to full numerical simulations. Routes for generating vortices in dipolar condensates are discussed, with particular attention paid to rotating condensates, where surface instabilities drive the nucleation of vortices, and lead to the emergence of rich and varied vortex lattice structures. We also present an outlook, including potential extensions to degenerate Fermi gases, quantum Hall physics, toroidal systems and the Berezinskii-Kosterlitz-Thouless transition.

  7. Ferrofluid based micro-electrical energy harvesting

    Purohit, Viswas; Mazumder, Baishakhi; Jena, Grishma; Mishra, Madhusha; Materials Department, University of California, Santa Barbara, CA93106 Collaboration

    2013-03-01

    Innovations in energy harvesting have seen a quantum leap in the last decade. With the introduction of low energy devices in the market, micro energy harvesting units are being explored with much vigor. One of the recent areas of micro energy scavenging is the exploitation of existing vibrational energy and the use of various mechanical motions for the same, useful for low power consumption devices. Ferrofluids are liquids containing magnetic materials having nano-scale permanent magnetic dipoles. The present work explores the possibility of the use of this property for generation of electricity. Since the power generation is through a liquid material, it can take any shape as well as response to small acceleration levels. In this work, an electromagnet-based micropower generator is proposed to utilize the sloshing of the ferrofluid within a controlled chamber which moves to different low frequencies. As compared to permanent magnet units researched previously, ferrofluids can be placed in the smallest of containers of different shapes, thereby giving an output in response to the slightest change in motion. Mechanical motion from 1- 20 Hz was able to give an output voltage in mV's. In this paper, the efficiency and feasibility of such a system is demonstrated.

  8. The drying process of concrete: a neutron radiography study

    Beer, F.C. de; Strydom, W.J.; Griesel, E.J.

    2004-01-01

    The natural drying process of concrete, which has a significant effect on its characteristics, for example durability, was studied at the neutron radiography facility at SAFARI-1 nuclear research reactor, operated by Necsa. Monitoring of the movement of the water in concrete samples, which were wet cured for one day and covered on all the sides but one, was done by means of a CCD camera system. In this paper the methodology in observing the drying process will be described together with results obtained from this investigation. The measured water content and porosity results were quantified and compared reasonably well with conventional gravimetrical measurements

  9. Advanced Drying Process for Lower Manufacturing Cost of Electrodes

    Ahmad, Iftikhar [Lambda Technologies, Inc., Morrisville, NC (United States); Zhang, Pu [Lambda Technologies, Inc., Morrisville, NC (United States)

    2016-11-30

    For this Vehicle Technologies Incubator/Energy Storage R&D topic, Lambda Technologies teamed with Navitas Systems and proposed a new advanced drying process that promised a 5X reduction in electrode drying time and significant reduction in the cost of large format lithium batteries used in PEV's. The operating principle of the proposed process was to use penetrating radiant energy source Variable Frequency Microwaves (VFM), that are selectively absorbed by the polar water or solvent molecules instantly in the entire volume of the electrode. The solvent molecules are thus driven out of the electrode thickness making the process more efficient and much faster than convective drying method. To evaluate the Advanced Drying Process (ADP) a hybrid prototype system utilizing VFM and hot air flow was designed and fabricated. While VFM drives the solvent out of the electrode thickness, the hot air flow exhausts the solvent vapors out of the chamber. The drying results from this prototype were very encouraging. For water based anodes there is a 5X drying advantage (time & length of oven) in using ADP over standard drying system and for the NMP based cathodes the reduction in drying time has 3X benefit. For energy savings the power consumption measurements were performed to ADP prototype and compared with the convection standard drying oven. The data collected demonstrated over 40% saving in power consumption with ADP as compared to the convection drying systems. The energy savings are one of the operational cost benefits possible with ADP. To further speed up the drying process, the ADP prototype was explored as a booster module before the convection oven and for the electrode material being evaluated it was possible to increase the drying speed by a factor of 4, which could not be accomplished with the standard dryer without surface defects and cracks. The instantaneous penetration of microwave in the entire slurry thickness showed a major advantage in rapid drying of

  10. Neutron depolarisation in ferrofluids during magnetising/demagnetising cycles

    Zabenkin, V N; Gordeev, G P; Lazebnik, I M; Orlova, D N; Kraan, W H; Vorobiev, A A

    2002-01-01

    3-D neutron depolarisation data were taken from ferrofluids of several concentrations along magnetic loops with the field both parallel and perpendicular to the neutron direction. The data taken at a concentration of 10 vol % of Fe sub 3 O sub 4 indicate a strong dependence of the organisation of the ferrofluid particles on the magnetic history over several cycles of the field. (orig.)

  11. Ferrofluids: Modeling, numerical analysis, and scientific computation

    Tomas, Ignacio

    This dissertation presents some developments in the Numerical Analysis of Partial Differential Equations (PDEs) describing the behavior of ferrofluids. The most widely accepted PDE model for ferrofluids is the Micropolar model proposed by R.E. Rosensweig. The Micropolar Navier-Stokes Equations (MNSE) is a subsystem of PDEs within the Rosensweig model. Being a simplified version of the much bigger system of PDEs proposed by Rosensweig, the MNSE are a natural starting point of this thesis. The MNSE couple linear velocity u, angular velocity w, and pressure p. We propose and analyze a first-order semi-implicit fully-discrete scheme for the MNSE, which decouples the computation of the linear and angular velocities, is unconditionally stable and delivers optimal convergence rates under assumptions analogous to those used for the Navier-Stokes equations. Moving onto the much more complex Rosensweig's model, we provide a definition (approximation) for the effective magnetizing field h, and explain the assumptions behind this definition. Unlike previous definitions available in the literature, this new definition is able to accommodate the effect of external magnetic fields. Using this definition we setup the system of PDEs coupling linear velocity u, pressure p, angular velocity w, magnetization m, and magnetic potential ϕ We show that this system is energy-stable and devise a numerical scheme that mimics the same stability property. We prove that solutions of the numerical scheme always exist and, under certain simplifying assumptions, that the discrete solutions converge. A notable outcome of the analysis of the numerical scheme for the Rosensweig's model is the choice of finite element spaces that allow the construction of an energy-stable scheme. Finally, with the lessons learned from Rosensweig's model, we develop a diffuse-interface model describing the behavior of two-phase ferrofluid flows and present an energy-stable numerical scheme for this model. For a

  12. The influence of lysozyme on mannitol polymorphism in freeze-dried and spray-dried formulations depends on the selection of the drying process.

    Grohganz, Holger; Lee, Yan-Ying; Rantanen, Jukka; Yang, Mingshi

    2013-04-15

    Freeze-drying and spray-drying are often applied drying techniques for biopharmaceutical formulations. The formation of different solid forms upon drying is often dependent on the complex interplay between excipient selection and process parameters. The purpose of this study was to investigate the influence of the chosen drying method on the solid state form. Mannitol-lysozyme solutions of 20mg/mL, with the amount of lysozyme varying between 2.5% and 50% (w/w) of total solid content, were freeze-dried and spray-dried, respectively. The resulting solid state of mannitol was analysed by near-infrared spectroscopy in combination with multivariate analysis and further, results were verified with X-ray powder diffraction. It was seen that the prevalence of the mannitol polymorphic form shifted from β-mannitol to δ-mannitol with increasing protein concentration in freeze-dried formulations. In spray-dried formulations an increase in protein concentration resulted in a shift from β-mannitol to α-mannitol. An increase in final drying temperature of the freeze-drying process towards the temperature of the spray-drying process did not lead to significant changes. It can thus be concluded that it is the drying process in itself, rather than the temperature, that leads to the observed solid state changes. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Advanced computational modelling for drying processes – A review

    Defraeye, Thijs

    2014-01-01

    Highlights: • Understanding the product dehydration process is a key aspect in drying technology. • Advanced modelling thereof plays an increasingly important role for developing next-generation drying technology. • Dehydration modelling should be more energy-oriented. • An integrated “nexus” modelling approach is needed to produce more energy-smart products. • Multi-objective process optimisation requires development of more complete multiphysics models. - Abstract: Drying is one of the most complex and energy-consuming chemical unit operations. R and D efforts in drying technology have skyrocketed in the past decades, as new drivers emerged in this industry next to procuring prime product quality and high throughput, namely reduction of energy consumption and carbon footprint as well as improving food safety and security. Solutions are sought in optimising existing technologies or developing new ones which increase energy and resource efficiency, use renewable energy, recuperate waste heat and reduce product loss, thus also the embodied energy therein. Novel tools are required to push such technological innovations and their subsequent implementation. Particularly computer-aided drying process engineering has a large potential to develop next-generation drying technology, including more energy-smart and environmentally-friendly products and dryers systems. This review paper deals with rapidly emerging advanced computational methods for modelling dehydration of porous materials, particularly for foods. Drying is approached as a combined multiphysics, multiscale and multiphase problem. These advanced methods include computational fluid dynamics, several multiphysics modelling methods (e.g. conjugate modelling), multiscale modelling and modelling of material properties and the associated propagation of material property variability. Apart from the current challenges for each of these, future perspectives should be directed towards material property

  14. Research advances in dry anaerobic digestion process of solid ...

    The dry anaerobic digestion process is an innovative waste-recycling method to treat high-solidcontent bio-wastes. This can be done without dilution with water by microbial consortia in an oxygenfree environment to recover potential renewable energy and nutrient-rich fertilizer for sustainable solid waste management.

  15. Intensifying drying process with creation of functional plant compositions

    Zh. Petrova

    2015-05-01

    Full Text Available Introduction. The process of drying agricultural raw products is associated with loss of bioactive substances by the products exposed to heat, light, oxygen, or рН medium. It is reasonable to enhance the table beet processing technology in order to achieve maximum betanin conservation at lower energy consumption. Materials and methods. Table beets, rhubarbs, lemons, and tomatoes were dried at temperature of 50 to 100 ºС, air speed of 1.5 to 3.5 m/s, heat carrier water content of 7 to 15 g/kg, and layer thickness of 2 to 20 mm. The betanіn content was determined via absorption spectra, using the optical density value at 540 nm wavelength. A differential microcalorimeter was used for measuring evaporation heat consumption. Results and discussion.The effect of raw product pre-drying preparation was studied. With no preliminary preparation, the loss of betanin after drying reaches 66 %. The preliminary preparation technology we have developed includes boiling whole root crops with optimal selection of acid medium and allows us to reduce the betanin loss down to 6 %. Regretfully, the process requires large energy consumption. Low energy consumption pre-drying preparation method was developed for antioxidant raw products with thermal processing replaced by blending. The betanin loss, in this case, does not exceed 5 %. Optimal drying temperature of betanin-containing raw stock, after its preliminary processing, is 60 °С. It allows to keep up to 95 % of betanіn. Specific heat consumption for water evaporation out of the developed table beet based antioxidant plant compositions, with addition of rhubarb and lemon, is less by 4 to 5 % as compared to the initial components. Conclusions. Dependence of betanin loss in plant raw stock on the material temperature and composition components, in the course of their pre-drying preparation, was found. It was also found that water evaporation heat, for some antioxidant plant compositions developed, is less

  16. Ferrofluid magnetization in the bulk and in the vicinity of an interface to Si

    Vorobiev, A.; Axelrod, L.; Gordeev, G.; Major, J.; Zabenkin, V.; Toperverg, B.P

    2003-07-01

    The process of ferrofluid (FF) magnetization in low magnetic field is investigated by polarized neutrons in the bulk of the sample and in the vicinity of its bottom interface with an Si wafer. The bulk magnetization is determined in experiments on the Larmor precession of the polarization vector of neutrons passing through the FF sample. The magnetization of the bottom layer is obtained with polarized neutron reflectometry. An appreciable difference between those two cases is shown.

  17. Magneto-optical extinction trend inversion in ferrofluids

    Shulyma, S.I., E-mail: kiw_88@mail.ru; Tanygin, B.M., E-mail: b.m.tanygin@gmail.com; Kovalenko, V.F.; Petrychuk, M.V.

    2016-10-15

    Effects of pulse magnetic field on the optical transmission properties of thin ferrofluid (FF) layers were experimentally investigated. It was observed that, under an influence of an external uniform magnetic field, pulses applied to the samples surfaces in normal direction decrease the optical transmission with further returning it to its original state, even before the end of the field pulse. The dependencies of the observed effects on the magnetic pulse magnitude and the samples thickness were investigated. The experimental results are explained using FF columnar aggregates growth and lateral coalescence under influence of a magnetic field, leading to a light scattering type Rayleigh-to-Mie transition. Further evolution of this process comes to a geometrical optics scale and respective macroscopic observable opaque FF columnar aggregates emergence. These changes of optical transmission are non-monotonic during the magnetic field pulse duration with minimal value in the case of Mie scattering, which is known as a magneto-optical extinction trend inversion. The residual inversion was detected after the external magnetic field pulse falling edge. Using molecular dynamics simulation, we showed that a homogeneous external magnetic field is enough for the formation of columnar aggregates and their fusion. The results clarify the known Li theory (Li et al., 2004, 2007), implying an inhomogeneous field as a required prerequisite for the magneto-optical extinction trend inversion phenomenon. - Highlights: • Ferrofluid columnar aggregates have been observed in a homogeneous magnetic field. • Magneto-optical extinction trend inversion is related to the Mie light scattering. • Crucial role of columnar aggregates growth and lateral coalescence has been revealed. • Residual extinction trend inversion was observed after the field switch off.

  18. Magneto-optical extinction trend inversion in ferrofluids

    Shulyma, S.I.; Tanygin, B.M.; Kovalenko, V.F.; Petrychuk, M.V.

    2016-01-01

    Effects of pulse magnetic field on the optical transmission properties of thin ferrofluid (FF) layers were experimentally investigated. It was observed that, under an influence of an external uniform magnetic field, pulses applied to the samples surfaces in normal direction decrease the optical transmission with further returning it to its original state, even before the end of the field pulse. The dependencies of the observed effects on the magnetic pulse magnitude and the samples thickness were investigated. The experimental results are explained using FF columnar aggregates growth and lateral coalescence under influence of a magnetic field, leading to a light scattering type Rayleigh-to-Mie transition. Further evolution of this process comes to a geometrical optics scale and respective macroscopic observable opaque FF columnar aggregates emergence. These changes of optical transmission are non-monotonic during the magnetic field pulse duration with minimal value in the case of Mie scattering, which is known as a magneto-optical extinction trend inversion. The residual inversion was detected after the external magnetic field pulse falling edge. Using molecular dynamics simulation, we showed that a homogeneous external magnetic field is enough for the formation of columnar aggregates and their fusion. The results clarify the known Li theory (Li et al., 2004, 2007), implying an inhomogeneous field as a required prerequisite for the magneto-optical extinction trend inversion phenomenon. - Highlights: • Ferrofluid columnar aggregates have been observed in a homogeneous magnetic field. • Magneto-optical extinction trend inversion is related to the Mie light scattering. • Crucial role of columnar aggregates growth and lateral coalescence has been revealed. • Residual extinction trend inversion was observed after the field switch off.

  19. Ferrofluid-in-oil two-phase flow patterns in a flow-focusing microchannel

    Sheu, T. S.; Chen, Y. T.; Lih, F. L.; Miao, J. M.

    This study investigates the two-phase flow formation process of water-based Fe3O4 ferrofluid (dispersed phase) in a silicon oil (continuous phase) flow in the microfluidic flow-focusing microchannel under various operational conditions. With transparent PDMS chip and optical microscope, four main two-phase flow patterns as droplet flow, slug flow, ring flow and churn flow are observed. The droplet shape, size, and formation mechanism were also investigated under different Ca numbers and intended to find out the empirical relations. The paper marks an original flow pattern map of the ferrofluid-in-oil flows in the microfluidic flow-focusing microchannels. The flow pattern transiting from droplet flow to slug flow appears for an operational conditions of QR < 1 and Lf / W < 1. The power law index that related Lf / W to QR was 0.36 in present device.

  20. Influence of water-based ferrofluid upon chlorophylls in cereals

    Racuciu, Mihaela [Lucian Blaga University, Faculty of Science, 10 Blvd. Victoriei, Sibiu, 550012 (Romania)]. E-mail: mracuciu@yahoo.com; Creanga, Dorina-Emilia [Al. I. Cuza University, Faculty of Physics, 11A Blvd.Copou, Iasi, 700506 (Romania)

    2007-04-15

    The present experimental investigation was focused on the study of the simultaneous influence of the water-based ferrofluid and static magnetic field exposure on young cereal plants. Water-based ferrofluid, stabilized with citric acid was added daily in various concentrations, ranging between 10 and 250 {mu}L/L, in the culture medium of maize (Zea mays) plants in their early ontogenetic stages. The used static magnetic field was about 50 mT. In order to investigate the biochemical changes of chlorophylls and total carotenoids, spectrophotometric measurements were carried out, that revealed stimulatory effects of ferrofluid and magnetic exposure upon the studied plant species.

  1. Cytogenetic changes induced by aqueous ferrofluids in agricultural plants

    Racuciu, Mihaela [Faculty of Sciences, Lucian Blaga University, 10 Blvd. Victoriei, Sibiu 550012 (Romania)]. E-mail: mracuciu@yahoo.com; Creanga, Dorina [Faculty of Physics, Al. I. Cuza University, 11A Blvd.Copou, Iasi 700506 (Romania)

    2007-04-15

    In this paper, the authors present their results regarding the cellular division rate and the percentage of chromosomal aberrations in the root meristematic cells of agricultural plants when cultivated in the presence of different concentrations of aqueous ferrofluid, ranging between 10 and 250 {mu}L/L. The agricultural species (Zea mays) with a major role in the life of people was chosen for the experimental project. The water-based ferrofluid was prepared following the chemical co-precipitation method, using tetramethylammonium hydroxide as magnetite core stabilizer. Microscopic investigations (cytogenetic tests) resulted in the evaluation of the mitotic and chromosomal aberration index. They appeared to increase following ferrofluid addition.

  2. Adaptive mechanical-wetting lens actuated by ferrofluids

    Cheng, Hui-Chuan; Xu, Su; Liu, Yifan; Levi, Shoshana; Wu, Shin-Tson

    2011-04-01

    We report an adaptive mechanical-wetting lens actuated by ferrofluids. The ferrofluids works like a piston to pump liquids in and out from the lens chamber, which in turn reshapes the lens curvature and changes the focal length. Both positive and negative lenses are demonstrated experimentally. The ferrofluid-actuated mechanical-wetting lens exhibits some attractive features, such as high resolution, fast response time, low power consumption, simple structure and electronic control, weak gravity effect, and low cost. Its potential applications in medical imaging, surveillance, and commercial electronics are foreseeable.

  3. Influence of water-based ferrofluid upon chlorophylls in cereals

    Racuciu, Mihaela; Creanga, Dorina-Emilia

    2007-01-01

    The present experimental investigation was focused on the study of the simultaneous influence of the water-based ferrofluid and static magnetic field exposure on young cereal plants. Water-based ferrofluid, stabilized with citric acid was added daily in various concentrations, ranging between 10 and 250 μL/L, in the culture medium of maize (Zea mays) plants in their early ontogenetic stages. The used static magnetic field was about 50 mT. In order to investigate the biochemical changes of chlorophylls and total carotenoids, spectrophotometric measurements were carried out, that revealed stimulatory effects of ferrofluid and magnetic exposure upon the studied plant species

  4. Utilization of geothermal heat in tropical fruit-drying process

    Chen, B.H.; Lopez, L.P.; King, R.; Fujii, J.; Tanaka, M.

    1982-10-01

    The power plant utilizes only the steam portion of the HGP-A well production. There are approximately 50,000 pounds per hour of 360/sup 0/F water produced (approximately 10 million Btu per hour) and the water is currently not used and is considered a waste. This tremendous resource could very well be used in applications such as food processing, food dehydration and other industrial processing that requires low-grade heat. One of the applications is examined, namely the drying of tropical fruits particularly the papaya. The papaya was chosen for the obvious reason that it is the biggest crop of all fruits produced on the Big Island. A conceptual design of a pilot plant facility capable of processing 1000 pounds of raw papaya per day is included. This facility is designed to provide a geothermally heated dryer to dehydrate papayas or other tropical fruits available on an experimental basis to obtain data such as drying time, optimum drying temperature, etc.

  5. Effect of drying parameters on physiochemical and sensory properties of fruit powders processed by PGSS-, Vacuum- and Spray-drying.

    Feguš, Urban; Žigon, Uroš; Petermann, Marcus; Knez, Željko

    2015-01-01

    Aim of this experimental work was to investigate the possibility of producing fruit powders without employing drying aid and to investigate the effect of drying temperatures on the final powder characteristics. Raw fruit materials (banana puree, strawberry puree and blueberry concentrate) were processed using three different drying techniques each operating at a different temperature conditions: vacuum-drying (-27-17 °C), Spray-drying (130-160 °C) and PGSS-drying (112-152 °C). Moisture content, total colour difference, antioxidant activity and sensory characteristics of the processed fruit powders were analysed. The results obtained from the experimental work indicate that investigated fruit powders without or with minimal addition of maltodextrin can be produced. Additionally, it was observed that an increase in process temperature results in a higher loss of colour, antioxidant activity and intensity of the flavour profile.

  6. Simulations of ferrofluid dynamics: Rigid dipoles model versus particles with internal degrees of freedom

    Berkov, D.V.; Gorn, N.L.; Stock, D.

    2007-01-01

    For numerical studies of a ferrofluid dynamics we have developed a model which includes internal magnetic degrees of freedom of ferrofluid particles. Contrary to standard models, we take into account that the magnetocrystalline anisotropy of a ferrofluid particle material is finite, so that the particle moment is allowed to rotate with respect to the particle itself. Simulating magnetization relaxation of a ferrofluid after switching off the external field and comparing results with those obtained for rigid dipoles model, we demonstrate that for anisotropy typical for commonly used ferrofluid materials inclusion of 'magnetic' degrees of freedom is essential for a correct description of ferrofluid dynamics

  7. Experimental research of solid waste drying in the process of thermal processing

    Bukhmirov, V. V.; Kolibaba, O. B.; Gabitov, R. N.

    2015-10-01

    The convective drying process of municipal solid waste layer as a polydispersed multicomponent porous structure is studied. On the base of the experimental data criterial equations for calculating heat transfer and mass transfer processes in the layer, depending on the humidity of the material, the speed of the drying agent and the layer height are obtained. These solutions are used in the thermal design of reactors for the thermal processing of multicomponent organic waste.

  8. Development of a modified dry curing process for beef.

    Hayes, J E; Kenny, T A; Ward, P; Kerry, J P

    2007-11-01

    The development of a dry curing process using physical treatments to promote the diffusion of the cure ingredients was studied. Vacuum pulsing with and without tumbling, continuous vacuum, and tumbling only treatments were compared with a conventional static dry cure control method on beef M. supraspinatus. Vacuum tumble and tumble only treatments gave highest core salt content after 7 days conditioning (3.3% and 3.1%, respectively). All test treatments resulted in higher colour uniformity and lower % cook loss in comparison to control (PCured beef slices were stored in modified atmosphere packs (MAP) (80%N(2):20%CO(2)) for up to 28 day at 4°C. Redness (a(∗), Pcured beef products with enhanced organoleptic quality and increased yields.

  9. Magnetoviscous effect in ferrofluids with different dispersion media

    Borin, D.Yu [TU Dresden, Institute of Fluid Mechanics, Dresden 01062 (Germany); Korolev, V.V. [G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo (Russian Federation); Ramazanova, A.G., E-mail: agr@isc-ras.ru [G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo (Russian Federation); Odenbach, S. [TU Dresden, Institute of Fluid Mechanics, Dresden 01062 (Germany); Balmasova, O.V.; Yashkova, V.I. [G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo (Russian Federation); Korolev, D.V. [Federal Sate Unitary Enterprise all Russian Scientific Research Institute of Aviation Materials (Russian Federation)

    2016-10-15

    Ferrofluids based on magnetite nanoparticles dispersed in different carrier media (dialkyldiphenyl and polyethylsiloxane) have been synthesized using mixed surfactants (oleic acid, stearic acid and alkenyl succinic anhydride). Magnetic properties of the samples and a change of their shear viscosities in an applied magnetic field have been studied in order to evaluate an influence of the carrier medium on a magnetoviscous effect. A significance of the interaction of the carrier medium and surfactant with a consideration of the magnetic and rheological behavior of ferrofluids was demonstrated. - Highlights: • Ferrofluids based on mixed surfactants were synthesized. • Oleic, stearic acid and alkenylsuccinic anhydride were used. • The nature of the surfactant has a high impact on the ferrofluids' shear viscosity. • The core size distribution is not the only determining reason of the structuring. • Significance of the interaction of the carrier medium and surfactant is demonstrated.

  10. Printing microstructures in a polymer matrix using a ferrofluid droplet

    Abdel Fattah, Abdel Rahman; Ghosh, Suvojit; Puri, Ishwar K.

    2016-01-01

    We print complex curvilinear microstructures in an elastomer matrix using a ferrofluid droplet as the print head. A magnetic field moves the droplet along a prescribed path in liquid polydimethylsiloxane (PDMS). The droplet sheds magnetic nanoparticle (MNP) clusters in its wake, forming printed features. The PDMS is subsequently heated so that it crosslinks, which preserves the printed features in the elastomer matrix. The competition between magnetic and drag forces experienced by the ferrofluid droplet and its trailing MNPs highlight design criteria for successful printing, which are experimentally confirmed. The method promises new applications, such as flexible 3D circuitry. - Highlights: • Magnetically guided miscible ferrofluid droplets print 3D patterns in a polymer. • Printing mechanism depends on the dynamics between the fluid and magnetic forces. • Droplet size influences the width of the printed trail. • The Colloidal distribution of the ferrofluid is important for pattern integrity. • Particle trajectories and trails are simulated and validated through experiments.

  11. Self-suspended permanent magnetic FePt ferrofluids

    Dallas, Panagiotis; Kelarakis, Antonios; Sahore, Ritu; DiSalvo, Francis J.; Livi, Sebastien; Giannelis, Emmanuel P.

    2013-01-01

    on the surface of L10 FePt nanoparticles. In contrast, all types of ferrofluids previously reported employ either volatile solvents as the suspending media or superparamagnetic iron oxide nanoparticles (that lacks permanent magnetization) as the inorganic

  12. Printing microstructures in a polymer matrix using a ferrofluid droplet

    Abdel Fattah, Abdel Rahman [Department of Mechanical Engineering, Hamilton, Ontario (Canada); Ghosh, Suvojit [Department of Engineering Physics, McMaster University, Hamilton, Ontario (Canada); Puri, Ishwar K. [Department of Mechanical Engineering, Hamilton, Ontario (Canada); Department of Engineering Physics, McMaster University, Hamilton, Ontario (Canada)

    2016-03-01

    We print complex curvilinear microstructures in an elastomer matrix using a ferrofluid droplet as the print head. A magnetic field moves the droplet along a prescribed path in liquid polydimethylsiloxane (PDMS). The droplet sheds magnetic nanoparticle (MNP) clusters in its wake, forming printed features. The PDMS is subsequently heated so that it crosslinks, which preserves the printed features in the elastomer matrix. The competition between magnetic and drag forces experienced by the ferrofluid droplet and its trailing MNPs highlight design criteria for successful printing, which are experimentally confirmed. The method promises new applications, such as flexible 3D circuitry. - Highlights: • Magnetically guided miscible ferrofluid droplets print 3D patterns in a polymer. • Printing mechanism depends on the dynamics between the fluid and magnetic forces. • Droplet size influences the width of the printed trail. • The Colloidal distribution of the ferrofluid is important for pattern integrity. • Particle trajectories and trails are simulated and validated through experiments.

  13. Investigation of influence of drying agent movement on the drying process effectiveness in the gravitational shelf dryer

    N. O. Artyukhova

    2017-12-01

    Full Text Available The article stands for a research of the drying process efficiency of various approaches of reciprocal movement organization of drying agent and disperse material. It focuses on the results of shelf dryer investigation. The test condition was as follows: backflow of the drying agent and disperse material movement; backflow of the drying agent and disperse material movement with the drying agent recirculation; backflow of the drying agent and disperse material movement with the bypassing of drying agent and it’s putting on separate stage of gravitational shelf dryer. The influence of the drying agent movement organization on the characteristics of disperse material and drying agent, energy costs for this process and its efficiency is shown. The recommendations of usage of represented approaches of flows movement organization depending on the desired final moisture of the material as well as its physical and chemical properties are given. The proposed ways of reciprocal flows movement organization allow to reduce the costs of drying agent heating or to increase the efficiency of moisture removal at constant energy consumption.

  14. Neutron depolarisation in ferrofluids during magnetising/demagnetising cycles

    Zabenkin, V.N.; Axelrod, L.A.; Gordeev, G.P.; Lazebnik, I.M.; Orlova, D.N. [Petersburg Nuclear Physics Institute, 188300, Gatchina (Russian Federation); Kraan, W.H. [Interfacultair Reactor Institute, TU-Delft, 2629 JB Delft (Netherlands); Vorobiev, A.A. [Petersburg Nuclear Physics Institute, 188300, Gatchina (Russian Federation); Max-Planck-Institut fuer Metallforschung, Heisenbergstr. 1, 70569 Stuttgart (Germany)

    2002-07-01

    3-D neutron depolarisation data were taken from ferrofluids of several concentrations along magnetic loops with the field both parallel and perpendicular to the neutron direction. The data taken at a concentration of 10 vol % of Fe{sub 3}O{sub 4} indicate a strong dependence of the organisation of the ferrofluid particles on the magnetic history over several cycles of the field. (orig.)

  15. Application of exopolysaccharides to optimize the performance of ceramic bodies in the unidirectional dry pressing process

    Caneira I.; Machado-Moreira, B.; Dionísio, A.; Godinho, V.; Neves, O.; Dias, Diamantino; Sáiz-Jiménez, Cesáreo; Miller, A. Z.

    2015-01-01

    Ceramic industry represents an important sector of economic activity in the European countries and involves complex and numerous manufacturing processes. The unidirectional dry pressing process includes milling and stirring of raw materials (mainly clay and talc minerals) in aqueous suspensions, followed by spray drying to remove excess water obtaining spray-dried powders further subjected to dry pressing process (conformation). However, spray-dried ceramic powders exhibit an important variab...

  16. Development and demonstration of calculation tool for industrial drying processes ''DryPack''; Udvikling og demonstration af beregningsvaerktoej til industrielle toerreprocesser ''DryPack''

    Schneider, P.; Weinkauff Kristoffersen, J.; Blazniak Andreasen, M. [Teknologisk Institut, Aarhus (Denmark); Elmegaard, B.; Kaern, M. [Danmarks Tekniske Univ.. DTU Mekanik, Kgs. Lyngby (Denmark); Monrad Andersen, C. [Lokal Energi, Viby J. (Denmark); Grony, K. [SE Big Blue, Kolding (Denmark); Stihoej, A. [Enervision, Kolding (Denmark)

    2013-03-15

    In this project we have developed a calculation tool for calculating energy consumption in different drying processes - primarily drying processes with air. The program can be used to determine the energy consumption of a current drying process, after which it can be calculated how much energy can be saved by various measures. There is also developed a tool for the simulation of a batch drier, which calculates the drying of a batch depending on the time. The programs have demonstrated their usefulness in connection with three cases that are reviewed in the report. In the project measurements on four different dryers have been carried out, and energy consumption is calculated using ''DryPack''. With ''DryPack'' it is possible to find potential savings by optimizing the drying processes. The program package includes utilities for the calculation of moist air: 1) Calculation of the thermodynamic properties of moist air; 2) Device operation with moist air (mixing, heating, cooling and humidification); 3) Calculation of the relative change of the drying time by changing the process parameters; 4) IX-diagram at a temperature above 100 deg. C. (LN)

  17. Pyrochemical and Dry Processing Methods Program. A selected bibliography

    McDuffie, H.F.; Smith, D.H.; Owen, P.T.

    1979-03-01

    This selected bibliography with abstracts was compiled to provide information support to the Pyrochemical and Dry Processing Methods (PDPM) Program sponsored by DOE and administered by the Argonne National Laboratory. Objectives of the PDPM Program are to evaluate nonaqueous methods of reprocessing spent fuel as a route to the development of proliferation-resistant and diversion-resistant methods for widespread use in the nuclear industry. Emphasis was placed on the literature indexed in the ERDA--DOE Energy Data Base (EDB). The bibliography includes indexes to authors, subject descriptors, EDB subject categories, and titles

  18. Pyrochemical and Dry Processing Methods Program. A selected bibliography

    McDuffie, H.F.; Smith, D.H.; Owen, P.T.

    1979-03-01

    This selected bibliography with abstracts was compiled to provide information support to the Pyrochemical and Dry Processing Methods (PDPM) Program sponsored by DOE and administered by the Argonne National Laboratory. Objectives of the PDPM Program are to evaluate nonaqueous methods of reprocessing spent fuel as a route to the development of proliferation-resistant and diversion-resistant methods for widespread use in the nuclear industry. Emphasis was placed on the literature indexed in the ERDA--DOE Energy Data Base (EDB). The bibliography includes indexes to authors, subject descriptors, EDB subject categories, and titles.

  19. Radiation processing of dry food ingredients - a review

    Farkas, J.

    1985-01-01

    Radiation decontamination of dry ingredients, herbs and enzyme preparations is a technically feasible, economically viable and safe physical process. The procedure is direct, simple, requires no additives, does not leave residues and is highly efficient. Its dose requirement is moderate. Radiation doses of 3 to 10 kGy proved to be sufficient to reduce the viable cell counts to a satisfactory level. Ionizing radiations do not cause any significant rise in temperature and the flavour, texture or other important technological or sensory properties of most ingredients are not influenced at radiation doses necessary for a satisfactory decontamination. The microflora surviving the cell-count reduction by irradiation is more sensitive to subsequent food processing treatments than the microflora of untreated ingredients. Recontamination can be prevented since the product can be irradiated in its final packaging. Irradiation can be carried out in commercial containers and it results in considerable savings of energy and labour as compared to alternative decontamination techniques. Radiation processing of dry ingredients is an emerging technology in several countries and more and more clearances on irradiated foods are issued or expected to be granted in the near future. (author)

  20. Radiation processing of dry food ingredients - a review

    Farkas, J

    1985-01-01

    Radiation decontamination of dry ingredients, herbs and enzyme preparations is a technically feasible, economically viable and safe physical process. The procedure is direct, simple, requires no additives, does not leave residues and is highly efficient. Its dose requirement is moderate. Radiation doses of 3 to 10 kGy proved to be sufficient to reduce the viable cell counts to a satisfactory level. Ionizing radiations do not cause any significant rise in temperature and the flavour, texture or other important technological or sensory properties of most ingredients are not influenced at radiation doses necessary for a satisfactory decontamination. The microflora surviving the cell-count reduction by irradiation is more sensitive to subsequent food processing treatments than the microflora of untreated ingredients. Recontamination can be prevented since the product can be irradiated in its final packaging. Irradiation can be carried out in commercial containers and it results in considerable savings of energy and labour as compared to alternative decontamination techniques. Radiation processing of dry ingredients is an emerging technology in several countries and more and more clearances on irradiated foods are issued or expected to be granted in the near future.

  1. Thin layer modelling of Gelidium sesquipedale solar drying process

    Ait Mohamed, L.; Ethmane Kane, C.S.; Kouhila, M.; Jamali, A.; Mahrouz, M.; Kechaou, N.

    2008-01-01

    The effect of air temperature and air flow rate on the drying kinetics of Gelidium sesquipedale was investigated in convective solar drying. Drying was conducted at 40, 50 and 60 deg. C. The relative humidity was varied from 50% to 57%, and the drying air flow rate was varied from 0.0277 to 0.0833 m 3 /s. The expression for the drying rate equation is determined empirically from the characteristic drying curve. Thirteen mathematical models of thin layer drying are selected in order to estimate the suitable model for describing the drying curves. The two term model gives the best prediction of the drying curves and satisfactorily describes the drying characteristics of G. sesquipedale with a correlation coefficient R of 0.9999 and chi-square (χ 2 ) of 3.381 x 10 -6

  2. Thin layer modelling of Gelidium sesquipedale solar drying process

    Ait Mohamed, L. [Laboratoire d' Energie Solaire et des Plantes Aromatiques et Medicinales, Ecole Normale Superieure, BP 2400, Marrakech (Morocco); Faculte des Sciences Semlalia, BP 2390, Marrakech (Morocco); Ethmane Kane, C.S. [Faculte des Sciences de Tetouan, BP 2121, Tetouan (Morocco); Kouhila, M.; Jamali, A. [Laboratoire d' Energie Solaire et des Plantes Aromatiques et Medicinales, Ecole Normale Superieure, BP 2400, Marrakech (Morocco); Mahrouz, M. [Faculte des Sciences Semlalia, BP 2390, Marrakech (Morocco); Kechaou, N. [Ecole Nationale d' Ingenieurs de Sfax, BPW 3038 (Tunisia)

    2008-05-15

    The effect of air temperature and air flow rate on the drying kinetics of Gelidium sesquipedale was investigated in convective solar drying. Drying was conducted at 40, 50 and 60 C. The relative humidity was varied from 50% to 57%, and the drying air flow rate was varied from 0.0277 to 0.0833 m{sup 3}/s. The expression for the drying rate equation is determined empirically from the characteristic drying curve. Thirteen mathematical models of thin layer drying are selected in order to estimate the suitable model for describing the drying curves. The two term model gives the best prediction of the drying curves and satisfactorily describes the drying characteristics of G. sesquipedale with a correlation coefficient R of 0.9999 and chi-square ({chi}{sup 2}) of 3.381 x 10{sup -6}. (author)

  3. Radiation decontamination of dry food ingredients and processing aids

    Farkas, J

    1984-01-01

    Radiation decontamination of dry ingredients, herbs and enzyme preparations is a technically feasible, economically viable and safe physical process. The procedure is direct, simple, requires no additives and is highly efficient. Its dose requirement is moderate. Radiation doses of 3-10 kGy (0.3-1 mrad) have proved sufficient to reduce the viable counts to a satisfactory level. Ionising radiations do not cause any significant rise in temperature. The flavour, texture or other important technological or sensory properties of most ingredients are not influenced at radiation doses necessary for satisfactory decontamination, and radiation obviates the chemical residue problem. The microflora surviving radiation decontamination of dry ingredients are more susceptible to subsequent antimicrobial treatments. Recontamination can be prevented as the product can be irradiated in its final packaging. Irradiation could be carried out in commercial containers and would result in considerable savings of energy and labour as compared to alternative decontamination techniques. Radiation processing of these commodities is an established technology in several countries and more clearances on irradiated foods are expected to be granted in the near future.

  4. Drying characteristics of zucchini and empirical modeling of its drying process

    Naciye Kutlu

    2017-10-01

    Full Text Available The aim of the study was to dry zucchini (Cucurbita pepo by two different methods (convective hot-air (CHD and microwave-assisted drying (MWD. The effect of air temperature (60, 70 and 80°C, microwave (MW power (180, 360, 540 W and sample thickness (5 and 10 mm on some drying characteristics of zucchini were investigated. Thirteen mathematical models available in the literature were fitted to the experimental moisture ratio data. The coefficients of the models were determined by non-linear regression analysis. It was determined that the model that fits the moisture ratio data the best varies at different drying conditions. Increasing drying temperature and MW power and reducing sample thickness improved the drying rate and drying time. Drying in microwave has reduced the drying time by 52-64% for zucchini. It was found that the effective moisture diffusivities increased with increasing temperature and MW power. MWD samples had better rehydration ratios compared to ones dried only in tray drier for 5 mm thickness.  

  5. Hydroclimatological Processes in the Central American Dry Corridor

    Hidalgo, H. G.; Duran-Quesada, A. M.; Amador, J. A.; Alfaro, E. J.; Mora, G.

    2015-12-01

    This work studies the hydroclimatological variability and the climatic precursors of drought in the Central American Dry Corridor (CADC), a subregion located in the Pacific coast of Southern Mexico and Central America. Droughts are frequent in the CADC, which is featured by a higher climatological aridity compared to the highlands and Caribbean coast of Central America. The CADC region presents large social vulnerability to hydroclimatological impacts originated from dry conditions, as there is a large part of population that depends on subsistance agriculture. The influence of large-scale climatic precursors such as ENSO, the Caribbean Low-Level Jet (CLLJ), low frequency signals from the Pacific and Caribbean and some intra-seasonal signals such as the MJO are evaluated. Previous work by the authors identified a connection between the CLLJ and CADC precipitation. This connection is more complex than a simple rain-shadow effect, and instead it was suggested that convection at the exit of the jet in the Costa-Rica and Nicaragua Caribbean coasts and consequent subsidence in the Pacific could be playing a role in this connection. During summer, when the CLLJ is stronger than normal, the Inter-Tropical Convergence Zone (located mainly in the Pacific) displaces to a more southern position, and vice-versa, suggesting a connection between these two processes that has not been fully explained yet. The role of the Western Hemisphere Warm Pool also needs more research. All this is important, as it suggest a working hypothesis that during summer, the effect of the Caribbean wind strength may be responsible for the dry climate of the CADC. Another previous analysis by the authors was based on downscaled precipitation and temperature from GCMs and the NCEP/NCAR reanalysis. The data was later used in a hydrological model. Results showed a negative trend in reanalysis' runoff for 1980-2012 in San José (Costa Rica) and Tegucigalpa (Honduras). This highly significant drying trend

  6. Improvement in dry active waste segregation and processing

    Hillmer, T.P.; Anderson, K.D.; Dahlen, D.E.

    1989-01-01

    At the Palo Verde Nuclear Generating Station (PVNGS) the majority of dry active waste (DAW) volume reduction activities are performed in the site's new DAW processing and storage facility. This facility houses an interim storage area for a five year volume of compacted DAW, a shredder/compactor, and a DAW segregation area. The DAW segregation program locates and separates non-radioactive and reusable materials from DAW generated at the three unit PVNGS site. This program has saved more than 24,000 cubic feet of burial space and has reclaimed more than $1,000,000 worth of materials. Palo Verde has made numerous changes to the DAW segregation program since its inception. To ensure that the DAW segregation program remained cost effective and in compliance with applicable regulatory guidance, segregation techniques were revised and new equipment was evaluated and procured. This paper details that effort and summarizes the operational data that has been collected

  7. Mathematical modeling of a convective textile drying process

    G. Johann

    2014-12-01

    Full Text Available This study aims to develop a model that accurately represents the convective drying process of textile materials. The mathematical modeling was developed from energy and mass balances and, for the solution of the mathematical model, the technique of finite differences, in Cartesian coordinates, was used. It transforms the system of partial differential equations into a system of ordinary equations, with the unknowns, the temperature and humidity of both the air and the textile material. The simulation results were compared with experimental data obtained from the literature. In the statistical analysis the Shapiro-Wilk test was used to validate the model and, in all cases simulated, the results were p-values greater than 5 %, indicating normality of the data. The R-squared values were above 0.997 and the ratios Fcalculated/Fsimulated, at the 95 % confidence level, higher than five, indicating that the modeling was predictive in all simulations.

  8. Particle dry deposition to water surfaces: Processes and consequences

    Pryor, S.C.; Barthelmie, R.J.

    2000-01-01

    flux to coastal waters, atmosphere-surface exchange represents a significant component of the total flux and may be particularly critical during the summertime when both the riverine input and ambient nutrient concentrations are often at a minimum. In this chapter, we present an overview...... of the physical and chemical processes which dictate the quantity (and direction) of atmosphere-surface fluxes of trace chemicals to (and above) water surfaces with particular emphasis on the role of particles. Dry deposition (transfer to the surface in the absence of precipitation) of particles is determined...... efforts to simulate and measure fluxes close to the coastline. These arise in part from the complexity of atmospheric flow in this region where energy and chemical fluxes are highly inhomogeneous in space and time and thermally generated atmospheric circulations are commonplace. (C) 2000 Elsevier Science...

  9. Study of Energy Consumption of Potato Slices During Drying Process

    Hafezi Negar

    2015-06-01

    Full Text Available One of the new methods of food drying using infrared heating under vacuum is to increase the drying rate and maintain the quality of dried product. In this study, potato slices were dried using vacuum-infrared drying. Experiments were performed with the infrared lamp power levels 100, 150 and 200 W, absolute pressure levels 20, 80, 140 and 760 mmHg, and with three thicknesses of slices 1, 2 and 3 mm, in three repetitions. The results showed that the infrared lamp power, absolute pressure and slice thickness have important effects on the drying of potato. With increasing the radiation power, reducing the absolute pressure (acts of vacuum in the dryer chamber and also reducing the thickness of potato slices, drying time and the amount of energy consumed is reduced. In relation to thermal utilization efficiency, results indicated that with increasing the infrared radiation power and decreasing the absolute pressure, thermal efficiency increased.

  10. Stress relaxation in a ferrofluid with clustered nanoparticles

    Borin, Dmitry Yu; Odenbach, Stefan; Zubarev, Andrey Yu; Chirikov, Dmitry N

    2014-01-01

    The formation of structures in a ferrofluid by an applied magnetic field causes various changes in the rheological behaviour of the ferrofluid. A ferrofluid based on clustered iron nanoparticles was investigated. We experimentally and theoretically consider stress relaxation in the ferrofluid under the influence of a magnetic field, when the flow is suddenly interrupted. It is shown that the residual stress observed in the fluid after the relaxation is correlated with the measured and theoretically predicted magnetic field-induced yield stress. Furthermore, we have shown that the total macroscopic stress in the ferrofluid after the flow is interrupted is defined by the presence of both linear chains and dense, drop-like bulk aggregates. The proposed theoretical approach is consistent with the experimentally observed behaviour, despite a number of simplifications which have been made in the formulation of the model. Thus, the obtained results contribute a lot to the understanding of the complex, magnetic field-induced rheological properties of magnetic colloids near the yield stress point. (paper)

  11. Analysis of a ferrofluid core differential transformer tilt measurement sensor

    Medvegy, T.; Molnár, Á.; Molnár, G.; Gugolya, Z.

    2017-04-15

    In our work, we developed a ferrofluid core differential transformer sensor, which can be used to measure tilt and acceleration. The proposed sensor consisted of three coils, from which the primary was excited with an alternating current. In the space surrounded by the coils was a cell half-filled with ferrofluid, therefore in the horizontal state of the sensor the fluid distributes equally in the three sections of the cell surrounded by the three coils. Nevertheless when the cell is being tilted or accelerated (in the direction of the axis of the coils), there is a different amount of ferrofluid in the three sections. The voltage induced in the secondary coils strongly depends on the amount of ferrofluid found in the core surrounded by them, so the tilt or the acceleration of the cell becomes measurable. We constructed the sensor in several layouts. The linearly coiled sensor had an excellent resolution. Another version with a toroidal cell had almost perfect linearity and a virtually infinite measuring range. - Highlights: • A ferrofluid core differential transformer can be used to measure tilt. • The theoretical description of two different type of the sensor is introduced. • The measuring range, and the sensitivity depends on the dimensions of the sensor.

  12. SOME STUDIES ABOUT CEREALS BEHAVIOR DURING FREEZE DRYING PROCESS

    GABRIELA-VICTORIA MNERIE

    2009-05-01

    Full Text Available The paper presents some special method and equipment and the principal advantages of freeze-dried food. The freeze drying is a good method of freeze-drying for make some experiments with many kind of cereals, for the improvement that in food production. It is necessary and is possible to study the corn oil extract, wheat flour, the maltodextrin from corn, modified cornstarch, spice extracts, soy sauce, hydrolyzed wheat gluten, partially hydrogenated soybean and cottonseed oil etc. That is very porous, since it occupies the same volume as the original and so rehydrates rapidly. There is less loss of flavour and texture than with most other methods of drying.

  13. Key composition optimization of meat processed protein source by vacuum freeze-drying technology

    Yan Ma

    2018-05-01

    Full Text Available Vacuum freeze-drying technology is a high technology content, a wide range of knowledge of technology in the field of drying technology is involved, it is also a method of the most complex drying equipment, the largest energy consumption, the highest cost of drying method, but due to the particularity of its dry goods: the freeze-drying food has the advantages of complex water performance is good, cooler and luster of freezing and drying food to maintain good products, less nutrient loss, light weight, easy to carry transportation, easy to long-term preservation, and on the quality is far superior to the obvious advantages of other dried food, making it become the forefront of drying technology research and development. The freeze-drying process of Chinese style ham and western Germany fruit tree tenderloin is studied in this paper, their eutectic point, melting point and collapse temperature, freeze-drying curve and its heat and mass transfer characteristics are got, then the precool temperature and the highest limiting temperature of sublimation interface are determined. The effect of system pressure on freeze-dried rate in freeze-drying process is discussed, and the method of regulating pressure circularly is determined. Keywords: Ham, Tenderloin, Vacuum freeze-dry, Processing, Optimization

  14. Drying of water based foundry coatings: Innovative test, process design and optimization methods

    Di Muoio, Giovanni Luca; Johansen, Bjørn Budolph

    on real industrial cases. These tools have been developed in order to simulate and optimize the drying process and reduce drying time and power consumption as well as production process design time and cost of expensive drying equipment. Results show that test methods from other industries can be used...... capacity goals there is a need to understand how to design, control and optimize drying processes. The main focus of this project was on the critical parameters and properties to be controlled in production in order to achieve a stable and predictable drying process. We propose for each of these parameters...... of Denmark with the overall aim to optimize the drying process of water based foundry coatings. Drying of foundry coatings is a relatively new process in the foundry industry that followed the introduction of water as a solvent. In order to avoid moisture related quality problems and reach production...

  15. Experimental demonstration of metamaterial "multiverse" in a ferrofluid.

    Smolyaninov, Igor I; Yost, Bradley; Bates, Evan; Smolyaninova, Vera N

    2013-06-17

    Extraordinary light rays propagating inside a hyperbolic metamaterial look similar to particle world lines in a 2 + 1 dimensional Minkowski spacetime. Magnetic nanoparticles in a ferrofluid are known to form nanocolumns aligned along the magnetic field, so that a hyperbolic metamaterial may be formed at large enough nanoparticle concentration nH. Here we investigate optical properties of such a metamaterial just below nH. While on average such a metamaterial is elliptical, thermal fluctuations of nanoparticle concentration lead to transient formation of hyperbolic regions (3D Minkowski spacetimes) inside this metamaterial. Thus, thermal fluctuations in a ferrofluid look similar to creation and disappearance of individual Minkowski spacetimes (universes) in the cosmological multiverse. This theoretical picture is supported by experimental measurements of polarization-dependent optical transmission of a cobalt based ferrofluid at 1500 nm.

  16. Wet milling versus co-precipitation in magnetite ferrofluid preparation

    Almásy László

    2015-01-01

    Full Text Available Various uses of ferrofluids for technical applications continuously raise the interest in improvement and optimization of preparation methods. This paper deals with preparation of finely granulated magnetite particles coated with oleic acid in hydrocarbon suspensions following either chemical co-precipitation from iron salt precursors or wet milling of micron size magnetite powder with the goal to compare the benefits and disadvantages of each method. Microstructural measurements showed that both methods gave similar magnetite particle size of 10-15 nm. Higher saturation magnetization was achieved for the wet-milled magnetite suspension compared to relatively rapid co-precipitation synthesis. Different efficacies of ferrophase incorporation into kerosene could be related to the different mechanisms of oleic acid bonding to nanoparticle surface. The comparative data show that wet milling represents a practicable alternative to the traditional co-precipitation since despite of longer processing time, chemicals impact on environment can be avoided as well as the remnant water in the final product.

  17. Performance degradation of ferrofluidic feedthroughs in a mixed irradiation field

    Simos, Nikolaos; Fernandes, S.; Mittig, Wolfgang; Pellemoine, Frederique; Avilov, M.; Kostin, M.; Mausner, L.; Ronningen, R.; Schein, M.; Bollen, G.

    2017-01-01

    Ferrofluidic feedthrough (FF) rotary seals containing either NdFeB or SmCo-type permanent magnets have been considered for use in the target and beam dump systems of the Facility for Rare Isotope Beams (FRIB). To evaluate their performance under irradiation three FF seals were irradiated in a mixed field consisting of fast neutrons, protons and γ-rays to an average absorbed dose of 0.2, 2.0, and 20.0 MGy at the Brookhaven Linac Isotope Producer facility (BLIP). The radiation types and energy profiles mimic those expected at the FRIB facility. Degradation of the operational performance of these devices due to irradiation is expected to be the result of the de-magnetization of the permanent magnets contained within the seal and the changes in the ferrofluid properties. Post-irradiation performance was evaluated by determining the ferrofluidic seal vacuum tightness and torque under static and dynamic conditions. The study revealed that the ferrofluidic feedthrough seal irradiated to a dose of 0.2 MGy maintained its vacuum tightness under both static and rotational condition while the one irradiated to a dose of 2.0 MGy exhibited signs of ferrofluid damage but no overall performance loss. At 20 MGy dose the effects of irradiation on the ferrofluid properties (viscosity and particle agglomeration) were shown to be severe. Furthermore, limited de-magnetization of the annular shaped Nd2Fe14B and Sm2Co17 magnets located within the irradiated FFs was observed for doses of 0.2 MGy and 20 MGy respectively.

  18. Effects of Freeze-Dried Vegetable Products on the Technological Process and the Quality of Dry Fermented Sausages.

    Eisinaite, Viktorija; Vinauskiene, Rimante; Viskelis, Pranas; Leskauskaite, Daiva

    2016-09-01

    The aim of this study was to compare the chemical composition of freeze-dried vegetable powders: celery, celery juice, parsnip and leek. The effect of different freeze-dried vegetables onto the ripening process and the properties of dry fermented sausages was also evaluated. Vegetable products significantly (p products contained higher amounts of nitrates, total phenolic compounds and lower amounts of sucrose, parsnip had higher concentration of proteins, leek was rich in fat. The analysis of pH, water activity, lactic acid bacteria, coagulase-positive staphylococci and coliforms content showed that the incorporation of freeze-dried vegetables had no negative effect on the fermentation and ripening process of dry fermented sausages. In addition, the color parameters for sausages with the added lyophilised celery products were considerable (p products and control. Freeze-dried celery, celery juice, parsnip and leek have some potential for the usage as a functional ingredient or as a source for indirect addition of nitrate in the production of fermented sausages. © 2016 Institute of Food Technologists®

  19. Computed tomographic analysis of vegetable during far infrared radiation drying process

    Maneechot, P.; Tojo, S.; Watanabe, K.

    2006-01-01

    Far Infrared Radiation (FIR) technology is widely used in the automotive industry to cure painted finishes during manufacturing. FIR drying is used not only in manufacturing but also in agricultural processing such as rice drying. At the present time, FIR drying technology has rarely been used for fruits and vegetables except in research laboratories. In this study, FIR drying and hot air convection drying were compared with respect to energy consumption and time requirement. The internal changes of the agricultural product were also observed during the FIR drying process. A Computed Tomographic (CT) scanner was employed for the observation of the tested material, carrot, and was used to analyze the structural deformation and the internal moisture distribution of the test material. CT data and the hardness of the sample were recorded at regular intervals during the drying experiment. For 200, 400 and 600W FIR drying, the maximum drying rates were 173, 459 and 724%d.b./hr respectively, and the required drying times were 26, 12 and 4.5 hours, respectively. The structure of the carrot sample shrank in accordance with the reduction of moisture content in 200W FIR drying as well as in hot air drying, whereas in 400W and 600W FIR drying the sample was dried without so much deformation

  20. PWR-to-PWR fuel cycle model using dry process

    Iqbal, M.; Jeong, Chang Joon; Rho, Gyu Hong

    2002-03-01

    PWR-to-PWR fuel cycle model has been developed to recycle the spent fuel using the dry fabrication process. Two types of fuels were considered; first fuel was based on low initial enrichment with low discharge burnup and second one was based on more initial enrichment with high discharge burnup in PWR. For recycling calculations, the HELIOS code was used, in which all of the available fission products were considered. The decay of 10 years was applied for reuse of the spent fuel. Sensitivity analysis for the fresh feed material enrichment has also been carried out. If enrichment of the mixing material is increased the saving of uranium reserves would be decreased. The uranium saving of low burned fuel increased from 4.2% to 7.4% in fifth recycling step for 5 wt% to 19.00wt% mixing material enrichment. While for high burned fuel, there was no uranium saving, which implies that higher uranium enrichment required than 5 wt%. For mixing of 15 wt% enriched fuel, the required mixing is about 21.0% and 37.0% of total fuel volume for low and high burned fuel, respectively. With multiple recycling, reductions in waste for low and high burned fuel became 80% and 60%, for first recycling, respectively. In this way, waste can be reduced more and the cost of the waste disposal reduction can provide the economic balance

  1. Supercritical fluid processing: a new dry technique for photoresist developing

    Gallagher-Wetmore, Paula M.; Wallraff, Gregory M.; Allen, Robert D.

    1995-06-01

    Supercritical fluid (SCF) technology is investigated as a dry technique for photoresist developing. Because of their unique combination of gaseous and liquid-like properties, these fluids offer comparative or improved efficiencies over liquid developers and, particularly carbon dioxide, would have tremendous beneficial impact on the environment and on worker safety. Additionally, SCF technology offers the potential for processing advanced resist systems which are currently under investigation as well as those that may have been abandoned due to problems associated with conventional developers. An investigation of various negative and positive photoresist systems is ongoing. Initially, supercritical carbon dioxide (SC CO2) as a developer for polysilane resists was explored because the exposure products, polysiloxanes, are generally soluble in this fluid. These initial studies demonstrated the viability of the SCF technique with both single layer and bilayer systems. Subsequently, the investigation focused on using SC CO2 to produce negative images with polymers that would typically be considered positive resists. Polymers such as styrenes and methacrylates were chemically modified by fluorination and/or copolymerization to render them soluble in SC CO2. Siloxane copolymers and siloxane-modified methacrylates were examined as well. The preliminary findings reported here indicate the feasibility of using SC CO2 for photoresist developing.

  2. Spray Drying Processing: granules production and drying kinetics of droplets; El proceso de secado por atomizacion: formacion de granulos y cinetica de secado de gotas

    Mondragon, R.; Julia, J. E.; Barba, A.; Jarque, J. C.

    2013-09-01

    Spray drying is a unit operation very common in many industrial processes. For each particular application, the resulting granulated material must possess determined properties that depend on the conditions in which the spray drying processing has been carried out, and whose dependence must be known in order to optimize the quality of the material obtained. The large number of variables that influence on the processes of matter and energy transfer and on the formation of granular material has required a detailed analysis of the drying process. Over the years there have been many studies on the spray drying processing of all kind of materials and the influence of process variables on the drying kinetics of the granulated material properties obtained. This article lists the most important works published for both the spray drying processing and the drying of individual droplets, as well as studies aimed at modeling the drying kinetics of drops. (Author)

  3. OPTIMUM DRYING PROCESS. Best drying conditions to grind fruits and vegetables

    Pina Laguna, Meritxell

    2013-01-01

    World’s population is increasing annually, thereby increasing world’s food demand. Considering current trends, changes in food production must be done in order to meet the estimated future demand. This problem and its possible solutions such as drying or pulverizing the foods, in which this thesis is focused on, are described in detail below.

  4. Key composition optimization of meat processed protein source by vacuum freeze-drying technology.

    Ma, Yan; Wu, Xingzhuang; Zhang, Qi; Giovanni, Vigna; Meng, Xianjun

    2018-05-01

    Vacuum freeze-drying technology is a high technology content, a wide range of knowledge of technology in the field of drying technology is involved, it is also a method of the most complex drying equipment, the largest energy consumption, the highest cost of drying method, but due to the particularity of its dry goods: the freeze-drying food has the advantages of complex water performance is good, cooler and luster of freezing and drying food to maintain good products, less nutrient loss, light weight, easy to carry transportation, easy to long-term preservation, and on the quality is far superior to the obvious advantages of other dried food, making it become the forefront of drying technology research and development. The freeze-drying process of Chinese style ham and western Germany fruit tree tenderloin is studied in this paper, their eutectic point, melting point and collapse temperature, freeze-drying curve and its heat and mass transfer characteristics are got, then the precool temperature and the highest limiting temperature of sublimation interface are determined. The effect of system pressure on freeze-dried rate in freeze-drying process is discussed, and the method of regulating pressure circularly is determined.

  5. CFD modelling of condensers for freeze-drying processes

    Freeze-drying; condenser; CFD simulation; mathematical modelling; ... it is used for the stabilization and storage of delicate, heat-sensitive materials .... The effect of the surface mass transfer has been included in the continuity equation and.

  6. Effect of aggregates on the magnetization property of ferrofluids: A model of gaslike compression

    Jian Li, Yan Huang, Xiaodong Liu, Yueqing Lin, Lang Bai and Qiang Li

    2007-01-01

    Full Text Available The effect of field-induced aggregation of particles on the magnetization property of ferrofluids is investigated. From the viewpoint of energy, magnetizability of ferrofluids is more complicated than predicted by Langevin theory because the aggregation, i.e., the transition of ferrofluid microstructure, would consume the energy of the applied magnetic field. For calculating the effect of aggregates on the magnetization of ferrofluids, a model of gaslike compression (MGC is proposed to simulate the evolution of the aggregate structure. In this model, the field-induced colloidal particles aggregating in ferrofluids is equivalent to the "gas of the particles" being compressed by the applied magnetic field. The entropy change of the ferrofluid microstructure is proportional to the particle volume fraction in field-induced aggregates phivH. On the basis of the known behavior of ferrofluid magnetization and the aggregate structure determined from the present experiments, phivH is obtained and found to depend on the aggregating characteristic parameter of ferrofluid particles γ in addition to the particle volume fraction in ferrofluids phiv and the strength of applied magnetic field H. The effect of the nonmagnetic surface layer of ferrofluid particles is also studied. The theory of MGC conforms to our experimental results better than Langevin theory.

  7. A ferrofluid based artificial tactile sensor with magnetic field control

    Volkova, T.I., E-mail: tatiana.volkova@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany); Böhm, V., E-mail: valter.boehm@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany); Naletova, V.A., E-mail: naletova@imec.msu.ru [Faculty of Mechanics and Mathematics, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Kaufhold, T., E-mail: tobias.kaufhold@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany); Becker, F., E-mail: felix.becker@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany); Zeidis, I., E-mail: igor.zeidis@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany); Zimmermann, K., E-mail: klaus.zimmermann@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany)

    2017-06-01

    The paper deals with a tactile sensor inspired by biological hairs of mammals. The working principle is based on the effect of the magnetic force exerted on a paramagnetic body submerged into a ferrofluid volume under the influence of a nonuniform magnetic field. The deflection of the sensor's rod caused by external mechanical stimuli may be unambiguously identified by the distortion of the magnetic field, which occurs due to the motion of the attached body in the ferrofluid. The magnetic force acting on the body is evaluated experimentally and theoretically for the nonuniform magnetic field of a permanent magnet. The controlled oscillations of the rod are realised by applying a nonuniform magnetic field of periodically altering direction. - Highlights: • A design approach of a tactile sensor inspired by special mammalian hairs is presented. • The working principle is based on magnetic properties of a ferrofluid in magnetic fields. • The magnetic force acting on a body submerged into a ferrofluid volume is evaluated. • External mechanical stimuli may be identified by the distortion of the magnetic field. • The controlled whisking-like oscillations of the sensor's rod are realised experimentally.

  8. Ferrofluid thin films as optical gaussmeters proposed for field and ...

    Department of Physics, Cochin University of Science and Technology, Cochin 682 022, India ... Magnetic field induced laser transmission through these ... An optical gaussmeter can be formulated with these ferrofluid thin films with the help of an LDR, and a laser (a diode laser or a cheaper torch laser which gives a stream ...

  9. A ferrofluid based artificial tactile sensor with magnetic field control

    Volkova, T.I.; Böhm, V.; Naletova, V.A.; Kaufhold, T.; Becker, F.; Zeidis, I.; Zimmermann, K.

    2017-01-01

    The paper deals with a tactile sensor inspired by biological hairs of mammals. The working principle is based on the effect of the magnetic force exerted on a paramagnetic body submerged into a ferrofluid volume under the influence of a nonuniform magnetic field. The deflection of the sensor's rod caused by external mechanical stimuli may be unambiguously identified by the distortion of the magnetic field, which occurs due to the motion of the attached body in the ferrofluid. The magnetic force acting on the body is evaluated experimentally and theoretically for the nonuniform magnetic field of a permanent magnet. The controlled oscillations of the rod are realised by applying a nonuniform magnetic field of periodically altering direction. - Highlights: • A design approach of a tactile sensor inspired by special mammalian hairs is presented. • The working principle is based on magnetic properties of a ferrofluid in magnetic fields. • The magnetic force acting on a body submerged into a ferrofluid volume is evaluated. • External mechanical stimuli may be identified by the distortion of the magnetic field. • The controlled whisking-like oscillations of the sensor's rod are realised experimentally.

  10. Numerical analysis of hydrodynamic journal bearings lubricated with ferrofluid

    Montazeri, H.

    2008-01-01

    The current work focuses on studying the hydrodynamic characteristics of flow in journal bearings lubricated with ferrofluid. The bearing has an infinite length and operates under incompressible laminar flow and steady conditions. Assuming linear behaviour for the magnetic material of the

  11. Magnetization behavior of ferrofluids with cryogenically imaged dipolar chains

    Klokkenburg, M; Erne, B H; Mendelev, V; Ivanov, A O

    2008-01-01

    Theories and simulations have demonstrated that field-induced dipolar chains affect the static magnetic properties of ferrofluids. Experimental verification, however, has been complicated by the high polydispersity of the available ferrofluids, and the morphology of the dipolar chains was left to the imagination. We now present the concentration- and field-dependent magnetization of particularly well-defined ferrofluids, with a low polydispersity, three different average particle sizes, and with dipolar chains that were imaged with and without magnetic field using cryogenic transmission electron microscopy. At low concentrations, the magnetization curves obey the Langevin equation for noninteracting dipoles. Magnetization curves for the largest particles strongly deviate from the Langevin equation but quantitatively agree with a recently developed mean-field model that incorporates the field-dependent formation and alignment of flexible dipolar chains. The combination of magnetic results and in situ electron microscopy images provides original new evidence for the effect of dipolar chains on the field-dependent magnetization of ferrofluids

  12. Magnetic Sensing with Ferrofluid and Fiber Optic Connectors

    Daniel Homa

    2014-02-01

    Full Text Available A simple, cost effective and sensitive fiber optic magnetic sensor fabricated with ferrofluid and commercially available fiber optic components is described in this paper. The system uses a ferrofluid infiltrated extrinsic Fabry-Perot interferometer (EFPI interrogated with an infrared wavelength spectrometer to measure magnetic flux density. The entire sensing system was developed with commercially available components so it can be easily and economically reproduced in large quantities. The device was tested with two different ferrofluid types over a range of magnetic flux densities to verify performance. The sensors readily detected magnetic flux densities in the range of 0.5 mT to 12.0 mT with measurement sensitivities in the range of 0.3 to 2.3 nm/mT depending on ferrofluid type. Assuming a conservative wavelength resolution of 0.1 nm for state of the art EFPI detection abilities, the estimated achievable measurement resolution is on the order 0.04 mT. The inherent small size and basic structure complimented with the fabrication ease make it well-suited for a wide array of research, industrial, educational and military applications.

  13. A capillary viscometer designed for the characterization of biocompatible ferrofluids

    Nowak, J., E-mail: johannes.nowak@tu-dresden.de; Odenbach, S.

    2016-08-01

    Suspensions of magnetic nanoparticles are receiving a growing interest in biomedical research. These ferrofluids can, e.g., be used for the treatment of cancer, making use of the drug targeting principle or using an artificially induced heating. To enable a safe application the basic properties of the ferrofluids have to be well understood, including the viscosity of the fluids if an external magnetic field is applied. It is well known that the viscosity of ferrofluids rises if a magnetic field is applied, where the rise depends on shear rate and magnetic field strength. In case of biocompatible ferrofluids such investigations proved to be rather complicated as the experimental setup should be close to the actual application to allow justified predictions of the effects which have to be expected. Thus a capillary viscometer, providing a flow situation comparable to the flow in a blood vessel, has been designed. The glass capillary is exchangeable and different inner diameters can be used. The range of the shear rates has been adapted to the range found in the human organism. The application of an external magnetic field is enabled with two different coil setups covering the ranges of magnetic field strengths required on the one hand for a theoretical understanding of particle interaction and resulting changes in viscosity and on the other hand for values necessary for a potential biomedical application. The results show that the newly designed capillary viscometer is suitable to measure the magnetoviscous effect in biocompatible ferrofluids and that the results appear to be consistent with data measured with rotational rheometry. In addition, a strong change of the flow behaviour of a biocompatible ferrofluid was proven for ranges of the shear rate and the magnetic field strength expected for a potential biomedical application. - Highlights: • A capillary viscometer to characterize biocompatible ferrofluids is presented. • Shear rates and capillary diameters

  14. Magnetoviscoelastic characteristics of superparamagnetic oxides (Fe, Ni) based ferrofluids

    Katiyar, Ajay, E-mail: ajay_k@ric.drdo.in [Research and Innovation Centre (DRDO), IIT Madras Research Park, Chennai 600113 (India); Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Dhar, Purbarun [Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 (India); Nandi, Tandra [Defence Materials and Stores Research and Development Establishment (DRDO), G.T. Road, Kanpur 208013 (India); Das, Sarit K. [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 (India)

    2017-08-15

    Highlights: • The magnetoviscous effect in ferrofluids in the presence of magnetic field is investigated. • Oxides of Fe and Ni are dispersed in oil to formulate the ferrofluids. • Drastic enhancement in the yield stress and viscosity under the magnetic field is observed for Fe{sub 3}O{sub 4}-based ferrofluids. • Viscoelastic properties of the formulated ferrofluids demonstrate the strong function of magnetic field. • The increase in temperature reduces the magneto-viscous effect in ferrofluids under the magnetic field. - Abstract: Ferrofluids have been popular among the academic and scientific communities owing to their intelligent physical characteristics under external stimuli and are in fact among the first nanotechnology products to be employed in real world applications. However, studies on the magnetoviscoelastic behavior of concentrated ferrofluids, especially of superparamagnetic oxides of iron and nickel are rare. The present article comprises the formulation of magneto-colloids utilizing the three various metal oxides nanoparticles viz. Iron (II, III) oxide (Fe{sub 3}O{sub 4}), Iron (III) oxide (Fe{sub 2}O{sub 3}) and Nickel oxide (NiO) in oil. Iron (II, III) oxide based colloids demonstrate high magnetoviscous characteristics over the other oxides based colloids under external magnetic fields. The maximum magnitude of yield stress and viscosity is found to be 3.0 kPa and 2.9 kPa.s, respectively for iron (II, III) oxide based colloids at 2.6 vol% particle concentration and 1.2 T magnetic field. Experimental investigations reveal that the formulated magneto-nanocolloids are stable, even in high magnetic fields and almost reversible when exposed to rising and drop of magnetic fields of the same magnitude. Observations also reveal that the elastic behavior dominates over the viscous behavior with enhanced relaxation and creep characteristics under the magnetic field. The effect of temperature on viscosity and yield stress of magneto

  15. Developing a framework to model the primary drying step of a continuous freeze-drying process based on infrared radiation

    Van Bockstal, Pieter-Jan; Corver, Jos; Mortier, Séverine Thérèse F.C.

    2018-01-01

    . These results assist in the selection of proper materials which could serve as IR window in the continuous freeze-drying prototype. The modelling framework presented in this paper fits the model-based design approach used for the development of this prototype and shows the potential benefits of this design...... requires the fundamental mechanistic modelling of each individual process step. Therefore, a framework is presented for the modelling and control of the continuous primary drying step based on non-contact IR radiation. The IR radiation emitted by the radiator filaments passes through various materials...

  16. A rheological and microscopical characterization of biocompatible ferrofluids

    Nowak, J.; Wolf, D.; Odenbach, S.

    2014-01-01

    There is an increasing interest in suspensions of magnetic nanoparticles in the biomedical area. Those ferrofluids are e.g. used for magnetic resonance imaging and emerging research focuses on employing the fluids for magnetic drug targeting or magnetic particle heating as a potential treatment for cancer. For these applications the knowledge of the suspensions' thermophysical properties is of major interest to guarantee a safe and effective application. Therefore the flow behavior cannot be neglected as it might significantly influence the execution of the aforementioned applications. In this experimental study two biocompatible ferrofluids were investigated. Rheological measurements were carried out using rotational rheometry. To allow an interpretation of the fluids' behavior the microscopic make-up was investigated using dynamic light scattering and transmission electron microscopy. Measurements of diluted ferrofluids were carried out as a first step to simulate the rheological behavior reflecting the concentration of magnetic nanoparticles found in blood flow for most biomedical applications of such fluids. The detected strong effects show the potential to significantly influence application and handling of the biocompatible ferrofluids in the medical area and should therefore be taken into account for further research as well as for the application of such fluids. - Highlights: • The rheology of biocompatible multicore ferrofluids is influenced by magnetic fields. • The flow curves can be described by the Herschel–Bulkley model. • A connection between the magnetoviscous effect and the particle size is found. • The strong magnetoviscous effect exists even if the fluids are diluted. • The connection between the effect and the dilution is mathematically described

  17. Rheological characterization of a magnetorheological ferrofluid using iron nitride nanoparticles

    Armijo, Leisha M.; Ahuré-Powell, Louise A.; Wereley, Norman M.

    2015-05-01

    Magnetorheology of a magnetorheological ferrofluid (MRFF) was investigated to study the role of a ferromagnetic nanoparticle (NP) additive in magnetorheological fluids (MRFs). Iron nitride (Fe16N2) NPs, nominally within the diameter range of ˜16-45 nm (spherical NPs) and ˜30-66 nm (cubic NPs), were coated with carboxy-polyethylene glycol (carboxy-PEG) and dispersed in silicone oil in order to produce a magnetic carrier fluid or ferrofluid for two solids loadings: 2 vol. % and 5 vol. %. Conventional spherical carbonyl iron (CI) particles, varying in diameter from 6 to 10 μm, were suspended in the ferrofluid at 25 vol. % solids loading. Rheological properties of the MRFF synthesized with the carboxy-PEG-based ferromagnetic carrier fluid were compared to the MRF synthesized with silicone oil to determine how ferrofluid can influence dynamic viscosity and yield stress. Rheological measurements of both MRF and MRFF samples were carried out using a Paar Physica 300 rheometer to estimate the field-off viscosity and to measure flow curves (i.e., shear stress vs. shear rate) as a function of magnetic field. A Bingham-plastic model was used to characterize the flow curves, and results show that there is an increase in the dynamic viscosity of the MRFF over the MRF. The ferromagnetic carrier fluid greatly increases yield stress as only 2 vol. % of added carboxy-PEG NPs improves the yield stress performance by almost 5%. A second MRFF sample synthesized with 5 vol. % of added carboxy-PEG NPs contained in the ferrofluid significantly enhanced the yield stress performance by 13% over the MRF at the same CI solids loading (25 vol. %).

  18. Design of Temperature Measurement System on the Drying Process of Madura Tobacco Leaves

    Wardana, Humadillah Kurniadi; Endarko, Endarko

    2015-01-01

    The quality of dried chopped leaves of tobacco is an important factor. The present work developed an oven for drying process to measure and evalute on drying shrinkage characteristic of choped leaves Madura tobacco. The oven has three racks for analyzing and monitoring the rate of drying shrinkage of Madura tobacco. Every rack has a different amount of chopped leaves as follows: 120 g on top rack, 100 g for middle rack and 80 g for bottom rack. Rate of drying shrinkage was analyzed for 20 min...

  19. Tropical dry forest recovery : processes and causes of change

    Lebrija Trejos, E.E.

    2009-01-01

    Seasonally dry areas are one of the preferred zones for human inhabitance in the tropics. Large forest areas are converted to other land uses and many are covered by secondary forests that grow naturally after cessation of disturbance. Surprisingly, secondary succession in these strongly seasonal

  20. Temperature processes at two sliding surfaces subjected to dry friction

    Půst, Ladislav; Pešek, Luděk; Cibulka, Jan; Bula, Vítězslav

    2012-01-01

    Roč. 63, 5/6 (2012), s. 277-292 ISSN 0039-2472 R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : dry friction * vibration damping * experimental set * increase of temperature * lost energy Subject RIV: BI - Acoustics

  1. Optimization of frozen wild blueberry vacuum drying process

    Šumić Zdravko M.

    2015-01-01

    Full Text Available The objective of this research was to optimize the vacuum drying of frozen blueberries in order to preserve health benefits phytochemicals using response surface methodology. The drying was performed in a new design of vacuum dryer equipment. Investigated range of temperature was 46-74°C and of pressure 38-464 mbar. Total solids, total phenolics, vitamin C, anthocyanin content and total color change were used as quality indicators of dried blueberries. Within the experimental range of studied variables, the optimum conditions of 60 °C and 100 mbar were established for vacuum drying of blueberries. Separate validation experiments were conducted at optimum conditions to verify predictions and adequacy of the second-order polynomial models. Under these optimal conditions, the predicted amount of total phenolics was 3.70 mgCAE/100dw, vitamin C 59.79 mg/100gdw, anthocyanin content 2746.33 mg/100gdw, total solids 89.50% and total color change 88.83. [Projekat Ministarstva nauke Republike Srbije, br. TR 31044

  2. Effects of different drying processes on the concentrations of metals and metalloids in plant materials

    Anawar, H.M.; Canha, N.; Freitas, M.C; Santa Regina, I.; Garcia-Sanchez, A.

    2011-01-01

    The drying process of fresh plant materials may affect the porous structure, dehydration and a number of quality characteristics of these materials. Therefore, this study has investigated the effect of different drying processes on the variation of metal and metalloid concentrations in the dried plant materials. Seven varieties of native plant species collected from Sao Domingos mine were analyzed by instrumental neutron activation analysis (INAA) to investigate the effects of freeze-drying (FD), ambient air-drying (AAD) and oven-drying (OD) process on the concentrations of metals and metalloids in the plant biomass. Comparison of ambient air-dried, oven-dried and freeze-dried preparations allows a phenomenological description of the dehydration artefacts. In the quantitative analysis of metals and metalloids, FD and OD plant samples show the higher concentrations of metals and metalloids when compared to those in the AAD plant biomass. The freeze-drying process is comparatively reliable for determination of metals and metalloids concentrations in plant materials. (author)

  3. The effect of dryer load on freeze drying process design.

    Patel, Sajal M; Jameel, Feroz; Pikal, Michael J

    2010-10-01

    Freeze-drying using a partial load is a common occurrence during the early manufacturing stages when insufficient amounts of active pharmaceutical ingredient (API) are available. In such cases, the immediate production needs are met by performing lyophilization with less than a full freeze dryer load. However, it is not obvious at what fractional load significant deviations from full load behavior begin. The objective of this research was to systematically study the effects of variation in product load on freeze drying behavior in laboratory, pilot and clinical scale freeze-dryers. Experiments were conducted with 5% mannitol (high heat and mass flux) and 5% sucrose (low heat and mass flux) at different product loads (100%, 50%, 10%, and 2%). Product temperature was measured in edge as well as center vials with thermocouples. Specific surface area (SSA) was measured by BET gas adsorption analysis and residual moisture was measured by Karl Fischer. In the lab scale freeze-dryer, the molar flux of inert gas was determined by direct flow measurement using a flowmeter and the molar flux of water vapor was determined by manometric temperature measurement (MTM) and tunable diode laser absorption spectroscopy (TDLAS) techniques. Comparative pressure measurement (capacitance manometer vs. Pirani) was used to determine primary drying time. For both 5% mannitol and 5% sucrose, primary drying time decreases and product temperature increases as the load on the shelves decreases. No systematic variation was observed in residual moisture and vapor composition as load decreased. Further, SSA data suggests that there are no significant freezing differences under different load conditions. Independent of dryer scale, among all the effects, variation in radiation heat transfer from the chamber walls to the product seems to be the dominant effect resulting in shorter primary drying time as the load on the shelf decreases (i.e., the fraction of edge vials increases).

  4. Microstructural and bulk property changes in hardened cement paste during the first drying process

    Maruyama, Ippei, E-mail: ippei@dali.nuac.nagoya-u.ac.jp [Graduate School of Environmental Studies, Nagoya University, ES Building, No. 546, Furo-cho, Chikusa-ku, Nagoya 464–8603 (Japan); Nishioka, Yukiko; Igarashi, Go [Graduate School of Environmental Studies, Nagoya University, ES Building, No. 539, Furo-cho, Chikusa-ku, Nagoya 464–8603 (Japan); Matsui, Kunio [Products and Marketing Development Dept. Asahi-KASEI Construction Materials Corporation, 106 Someya, Sakai-machi, Sashima-gun, Ibaraki, 306–0493 (Japan)

    2014-04-01

    This paper reports the microstructural changes and resultant bulk physical property changes in hardened cement paste (hcp) during the first desorption process. The microstructural changes and solid-phase changes were evaluated by water vapor sorption, nitrogen sorption, ultrasonic velocity, and {sup 29}Si and {sup 27}Al nuclear magnetic resonance. Strength, Young's modulus, and drying shrinkage were also examined. The first drying process increased the volume of macropores and decreased the volume of mesopores and interlayer spaces. Furthermore, in the first drying process globule clusters were interconnected. During the first desorption, the strength increased for samples cured at 100% to 90% RH, decreased for 90% to 40% RH, and increased again for 40% to 11% RH. This behavior is explained by both microstructural changes in hcp and C–S–H globule densification. The drying shrinkage strains during rapid drying and slow drying were compared and the effects of the microstructural changes and evaporation were separated.

  5. Ferrofluid of magnetic clay and menthol based deep eutectic solvent: Application in directly suspended droplet microextraction for enrichment of some emerging contaminant explosives in water and soil samples.

    Zarei, Ali Reza; Nedaei, Maryam; Ghorbanian, Sohrab Ali

    2018-06-08

    In this work, for the first time, ferrofluid of magnetic montmorillonite nanoclay and deep eutectic solvent was prepared and coupled with directly suspended droplet microextraction. Incorporation of ferrofluid in a miniaturized sample preparation technique resulted in achieving high extraction efficiency while developing a green analytical method. The prepared ferrofluid has strong sorbing properties and hydrophobic characteristics. In this method, a micro-droplet of ferrofluid was suspended into the vortex of a stirring aqueous solution and after completing the extraction process, was easily separated from the solution by a magnetic rod without any operational problems. The predominant experimental variables affecting the extraction efficiency of explosives were evaluated. Under optimal conditions, the limits of detection were in the range 0.22-0.91 μg L -1 . The enrichment factors were between 23 and 93 and the relative standard deviations were <10%. The relative recoveries were ranged from 88 to 104%. This method was successfully applied for the extraction and preconcentration of explosives in water and soil samples, followed their determination by high performance liquid chromatography with ultraviolet detection (HPLC-UV). Copyright © 2018 Elsevier B.V. All rights reserved.

  6. MEASUREMENT OF INDOOR AIR EMISSIONS FROM DRY-PROCESS PHOTOCOPY MACHINES

    The article provides background information on indoor air emissions from office equipment, with emphasis on dry-process photocopy machines. The test method is described in detail along with results of a study to evaluate the test method using four dry-process photocopy machines. ...

  7. Exergoeconomic analyses of a gas engine driven heat pump drier and food drying process

    Gungor, Aysegul; Erbay, Zafer; Hepbasli, Arif

    2011-01-01

    Exergoeconomic analysis of a pilot scale gas engine driven heat pump (GEHP) drying system is performed based on the experimental values using Exergy, Cost, Energy and Mass (EXCEM) analysis method in this study. The performance of the drying system components is discussed, while the important system components are determined to improve the system efficiency. The performance of the drying process is also analyzed for three different medicinal and aromatic plants from the exergoeconomic point of view. A comprehensive parametric study is conducted to investigate the effect of varying dead (reference) state temperatures on exergoeconomic performance parameters for both drying system components and drying process. The correlations between the performance parameters and dead state temperatures are developed. The results have indicated that the dead state temperature affects the performance parameters, particularly the drying process parameters. Rising the dead state temperature leads to an increase in the exergy efficiencies of the drying process and a decrease in the ratio of the thermodynamic loss rate to the capital cost (R . ex ) values in a polynomial form. R . ex values of the drying process are obtained to be very higher compared to those of the drying system components.

  8. Simulation of the process kinetics and analysis of physicochemical properties in the freeze drying of kale

    Dziki, Dariusz; Polak, Renata; Rudy, Stanisław; Krzykowski, Andrzej; Gawlik-Dziki, Urszula; Różyło, Renata; Miś, Antoni; Combrzyński, Maciej

    2018-01-01

    Investigations were performed to study the freeze-drying process of kale (Brassica oleracea L. var acephala). The process of freeze-drying was performed at temperatures of 20, 40, and 60°C for whole pieces of leaves and for pulped leaves. The kinetics of the freeze-drying of both kale leaves and kale pulp were best described by the Page model. The increasing freeze-drying temperature from 20 to 60°C induced an approximately two-fold decrease in the drying time. Freeze-drying significantly increased the value of the lightness, delta Chroma, and browning index of kale, and had little influence on the hue angle. The highest increase in the lightness and delta Chroma was observed for whole leaves freeze-dried at 20°C. An increase in the drying temperature brought about a slight decrease in the lightness, delta Chroma and the total colour difference. Pulping decreased the lightness and hue angle, and increased browning index. Freeze-drying engendered a slight decrease in the total phenolics content and antioxidant activity, in comparison to fresh leaves. The temperature of the process and pulping had little influence on the total phenolics content and antioxidant activity of dried kale, but significantly decreased the contents of chlorophyll a and chlorophyll b.

  9. Montmorillonite based artificial nacre prepared via a drying process

    Bennadji-Gridi, Fayza; Smith, Agnes; Bonnet, Jean-Pierre

    2006-01-01

    Taking advantage of the specific behaviour of Na/Ca montmorillonite in aqueous dispersion, textured films were prepared by progressive evaporation of dispersions with low concentrations of delaminated platelets. The increase of the concentration of ions during evaporation changes the nature of the clay mineral platelet face interactions from repulsive to attractive. After complete drying, a dense brick-like structure is obtained when a sodium salt is used as deflocculant. The bending strength of the textured film is strongly affected by cracks formation during drying, specially when the sample thickness increases. After optimisation, crack-free textured samples with a 140 μm thickness, 20 cm x 25 cm area and 120 MPa bending strength were obtained

  10. The Effect of External Magnetic Field on Dielectric Permeability of Multiphase Ferrofluids

    Dotsenko, O. A.; Pavlova, A. A.; Dotsenko, V. S.

    2018-03-01

    Nowadays, ferrofluids are applied in various fields of science and technology, namely space, medicine, geology, biology, automobile production, etc. In order to investigate the feasibility of applying ferrofluids in magnetic field sensors, the paper presents research into the influence of the external magnetic field on dielectric permeability of ferrofluids comprising magnetite nanopowder, multiwall carbon nanotubes, propanetriol and deionized water. The real and imaginary parts of the dielectric permeability change respectively by 3.7 and 0.5% when applying the magnetic field parallel to the electric. The findings suggest that the considered ferrofluid can be used as a magnetic level gauge or in design of variable capacitors.

  11. Process and apparatus for indirect-fired heating and drying

    Abbasi, Hamid Ali; Chudnovsky, Yaroslav

    2005-04-12

    A method for heating flat or curved surfaces comprising injecting fuel and oxidant along the length, width or longitudinal side of a combustion space formed between two flat or curved plates, transferring heat from the combustion products via convection and radiation to the surface being heated on to the material being dried/heated, and recirculating at least 20% of the combustion products to the root of the flame.

  12. All-dry resist processes for 193-nm lithography

    Horn, Mark W.; Maxwell, Brian E.; Kunz, Roderick R.; Hibbs, Michael S.; Eriksen, Lynn M.; Palmateer, Susan C.; Forte, Anthony R.

    1995-06-01

    We report on two different all-dry resist schemes for 193-nm lithography, one negative tone and one positive tone. Our negative tone resist is an extension of our initial work on all-dry photoresists. This scheme employs a bilayer in which the imaging layer is formed by plasma enhanced chemical vapor deposition (PECVD) from tetramethylsilane (TMS) and deposited onto PECVD carbon-based planarizing layers. Figure 1 shows SEMs of dark field and light field octagons patterned in projection on Lincoln Laboratory's 0.5-NA 193-nm Micrascan system. These 0.225-micrometers and 0.200-micrometers line and space features were obtained at a dose of approximately 58 mJ/cm2. Dry development of the exposed resist was accomplished using Cl2 chemistry in a helicon high-ion-density etching tool. Pattern transfer was performed in the helicon tool with oxygen-based chemistries. Recently, we have also developed an all-dry positive-tone silylation photoresist. This photoresist is a PECVD carbon-based polymer which is crosslinked by 193-nm exposure, enabling selective silylation similar to that initially reported by Hartney et al., with spin-applied polymers. In those polymers, for example polyvinylphenol, the silylation site concentration is fixed by the hydroxyl groups on the polymer precursors, thus limiting the silicon uptake per unit volume. With PECVD polymers, the total concentration of silylation sites and their depth can be tailored by varying plasma species as a function of time during the deposition. This affords the possibility of greater silicon uptake per unit volume and better depth control of the silylation profile. Figure 2 shows a SEM of 0.5-micrometers features patterned in plasma deposited silylation resist.

  13. Freeze-dried processing of tungsten heavy alloys

    White, G.D.; Gurwell, W.E.

    1989-06-01

    Tungsten heavy alloy powders were produced from freeze-dried aqueous solutions of ammonium metatungstate and, principally, sulfates of Ni and Fe. The freeze-dried salts were calcined and hydrogen reduced to form very fine, homogeneous, low-density, W heavy alloy powders having a coral-like structure with elements of approximately 0.1 μm in diameter. The powders yield high green strength and sinterability. Tungsten heavy alloy powders of 70%, 90%, and 96% W were prepared by freeze drying, compacted, and solid-state (SS) sintered to fully density at temperatures as low as 1200 degree C and also at conventional liquid-phase (LP) sintering temperatures. Solid-state sintered microstructures contained polygonal W grains with high contiguity; the matrix did not coat and separate the W grains to form low-contiguity, high-ductility structures. Liquid-phase sintered microstructures were very conventional in appearance, having W spheroids of low contiguity. All these materials were found to be brittle. High levels of residual S accompanied by segregation of the S to all the microstructural interfaces are principally responsible for the brittleness; problems with S could be eliminated by using Fe and Ni nitrates rather than the sulfates. 9 refs., 22 figs., 3 tabs

  14. Correlations of Mean Process Parameters for Agricultural Products Drying in Thin Bed in Solar Direct Dryers

    MSc. Ciro César Bergues-Ricardo

    2015-11-01

    Full Text Available A group of correlations is given between mean parameters of drying process drying velocity, energy losses, useful energy, and thermal efficiency. Those are suitable for conditions of thin bed drying, in direct solar dryers, and may help for developing of an integral approach of solar drying in those conditions. Correlations are reliable for drying processes of diverse crop products specified, suchas roots, seeds, vegetables, fruits, wood, etc, with natural or forced convection. Correlations were validated in Cuba for usual ranges of efficiency and products in solar dryers of cover, cabinet and house types, in tropical conditions. These correlations are useful for design and exploitation ofdryers and for theoretical and practical comprehension of solar drying like a system.

  15. Global Sensitivity Analysis as Good Modelling Practices tool for the identification of the most influential process parameters of the primary drying step during freeze-drying

    Van Bockstal, Pieter-Jan; Mortier, Séverine Thérèse F.C.; Corver, Jos

    2018-01-01

    Pharmaceutical batch freeze-drying is commonly used to improve the stability of biological therapeutics. The primary drying step is regulated by the dynamic settings of the adaptable process variables, shelf temperature Ts and chamber pressure Pc. Mechanistic modelling of the primary drying step...

  16. Sensory profiles for dried fig (Ficus carica L.) cultivars commercially grown and processed in California.

    Haug, Megan T; King, Ellena S; Heymann, Hildegarde; Crisosto, Carlos H

    2013-08-01

    A trained sensory panel evaluated the 6 fig cultivars currently sold in the California dried fig market. The main flavor and aroma attributes determined by the sensory panel were "caramel," "honey," "raisin," and "fig," with additional aroma attributes: "common date," "dried plum," and "molasses." Sensory differences were observed between dried fig cultivars. All figs were processed by 2 commercial handlers. Processing included potassium sorbate as a preservative and SO2 application as an antibrowning agent for white cultivars. As a consequence of SO2 use during processing, high sulfite residues affected the sensory profiles of the white dried fig cultivars. Significant differences between dried fig cultivars and sources demonstrate perceived differences between processing and storage methods. The panel-determined sensory lexicon can help with California fig marketing. © 2013 The Regents of California, Davis Campus Department of Plant Sciences.

  17. An analytical method for determining the temperature dependent moisture diffusivities of pumpkin seeds during drying process

    Can, Ahmet [Department of Mechanical Engineering, University of Trakya, 22030 Edirne (Turkey)

    2007-02-15

    This paper presents an analytical method, which determines the moisture diffusion coefficients for the natural and forced convection hot air drying of pumpkin seeds and their temperature dependence. In order to obtain scientific data, the pumpkin seed drying process was investigated under both natural and forced hot air convection regimes. This paper presents the experimental results in which the drying air was heated by solar energy. (author)

  18. Study of the dry processing of uranium ores

    Guillet, H.

    1959-02-01

    A description is given of direct fluorination of pre-concentrated uranium ores in order to obtain the hexafluoride. After normal sulfuric acid treatment of the ore to eliminate silica, the uranium is precipitated by a load of lime to obtain: either impure calcium uranate of medium grade, or containing around 10% of uranium. This concentrate is dried in an inert atmosphere and then treated with a current of elementary fluorine. The uranium hexafluoride formed is condensed at the outlet of the reaction vessel and may be used either for reduction to tetrafluoride and the subsequent manufacture of uranium metal or as the initial product in a diffusion plant. (author) [fr

  19. Influence of Ripeness and Drying Process on the Polyphenols and Tocopherols of Pistacia vera L.

    Gabriele Ballistreri

    2009-10-01

    Full Text Available This paper highlights, for the first time, the changes in the phenolics fraction (anthocyanins, flavonoids and stilbenes and tocopherols of unpeeled Pistacia vera L. var. bianca with ripening, and the effect of the sun-drying process. The total polyphenol levels in pistachios, measured as mg of Gallic Acid Equivalent (GAE, were: 201 ± 10.1, 349 ± 18.3 and 184.7 ± 6.2 mg GAE/100 g DM in unripe, ripe and dried ripe samples, respectively. Most phenolics in ripe pistachios were found to be anthocyanins. They increased with ripening, while the sun drying process caused a susbtantial loss. Flavonoids found in all pistachio samples were daidzein, genistein, daidzin, quercetin, eriodictyol, luteolin, genistin and naringenin, which decreased both with ripening and drying. Before the drying process both unripe and ripe pistachios showed a higher content of trans-resveratrol than dried ripe samples. γ-Tocopherol was the major vitamin E isomer found in pistachios. The total content (of α- and γ-tocopherols decreased, both during ripening and during the drying process. These results suggested that unpeeled pistachios can be considered an important source of phenolics, particularly of anthocyanins. Moreover, in order to preserve these healthy characteristics, new and more efficient drying processes should be adopted.

  20. Graphene oxide for acid catalyzed-reactions: Effect of drying process

    Gong, H. P.; Hua, W. M.; Yue, Y. H.; Gao, Z.

    2017-03-01

    Graphene oxides (GOs) were prepared by Hummers method through various drying processes, and characterized by XRD, SEM, FTIR, XPS and N2 adsorption. Their acidities were measured using potentiometric titration and acid-base titration. The catalytic properties were investigated in the alkylation of anisole with benzyl alcohol and transesterification of triacetin with methanol. GOs are active catalysts for both reaction, whose activity is greatly affected by their drying processes. Vacuum drying GO exhibits the best performance in transesterification while freezing drying GO is most active for alkylation. The excellent catalytic behavior comes from abundant surface acid sites as well as proper surface functional groups, which can be obtained by selecting appropriate drying process.

  1. Parameters Online Detection and Model Predictive Control during the Grain Drying Process

    Lihui Zhang

    2013-01-01

    Full Text Available In order to improve the grain drying quality and automation level, combined with the structural characteristics of the cross-flow circulation grain dryer designed and developed by us, the temperature, moisture, and other parameters measuring sensors were placed on the dryer, to achieve online automatic detection of process parameters during the grain drying process. A drying model predictive control system was set up. A grain dry predictive control model at constant velocity and variable temperature was established, in which the entire process was dried at constant velocity (i.e., precipitation rate per hour is a constant and variable temperature. Combining PC with PLC, and based on LabVIEW, a system control platform was designed.

  2. A free boundary approach to the Rosensweig instability of ferrofluids

    Parini, Enea; Stylianou, Athanasios

    2018-04-01

    We establish the existence of saddle points for a free boundary problem describing the two-dimensional free surface of a ferrofluid undergoing normal field instability. The starting point is the ferrohydrostatic equations for the magnetic potentials in the ferrofluid and air, and the function describing their interface. These constitute the strong form for the Euler-Lagrange equations of a convex-concave functional, which we extend to include interfaces that are not necessarily graphs of functions. Saddle points are then found by iterating the direct method of the calculus of variations and applying classical results of convex analysis. For the existence part, we assume a general nonlinear magnetization law; for a linear law, we also show, via convex duality, that the saddle point is a constrained minimizer of the relevant energy functional.

  3. Spatial Dynamics Methods for Solitary Waves on a Ferrofluid Jet

    Groves, M. D.; Nilsson, D. V.

    2018-04-01

    This paper presents existence theories for several families of axisymmetric solitary waves on the surface of an otherwise cylindrical ferrofluid jet surrounding a stationary metal rod. The ferrofluid, which is governed by a general (nonlinear) magnetisation law, is subject to an azimuthal magnetic field generated by an electric current flowing along the rod. The ferrohydrodynamic problem for axisymmetric travelling waves is formulated as an infinite-dimensional Hamiltonian system in which the axial direction is the time-like variable. A centre-manifold reduction technique is employed to reduce the system to a locally equivalent Hamiltonian system with a finite number of degrees of freedom, and homoclinic solutions to the reduced system, which correspond to solitary waves, are detected by dynamical-systems methods.

  4. Magnetic manipulation of particles and cells in ferrofluid flow through straight microchannels using two magnets

    Zeng, Jian

    Microfluidic devices have been increasingly used in the past two decades for particle and cell manipulations in many chemical and biomedical applications. A variety of force fields have been demonstrated to control particle and cell transport in these devices including electric, magnetic, acoustic, and optical forces etc. Among these particle handling techniques, the magnetic approach provides clear advantages over others such as low cost, noninvasive, and free of fluid heating issues. However, the current knowledge of magnetic control of particle transport is still very limited, especially lacking is the handling of diamagnetic particle. This thesis is focused on the magnetic manipulation of diamagnetic particles and cells in ferrofluid flow through the use of a pair of permanent magnets. By varying the configuration of the two magnets, diverse operations of particles and cells is implemented in a straight microchannel that can potentially be integrated into lab-on-a-chip devices for various applications. First, an approach for embedding two, symmetrically positioned, repulsive permanent magnets about a straight rectangular microchannel in a PDMS-based microfluidic device is developed for particle focusing. Focusing particles and cells into a tight stream is often required in order for continuous detection, counting, and sorting. The closest distance between the magnets is limited only by the size of the magnets involved in the fabrication process. The device is used to implement and investigate the three-dimensional magnetic focusing of polystyrene particles in ferrofluid microflow with both top-view and side-view visualizations. The effects of flow speed and particle size on the particle focusing effectiveness are studied. This device is also applied to magnetically focus yeast cells in ferrofluid, which proves to be biocompatible as verified by cell viability test. In addition, an analytical model is developed and found to be able to predict the experimentally

  5. Textile Dry Cleaning Using Carbon Dioxide : Process, Apparatus and Mechanical Action

    Sutanto, S.

    2014-01-01

    Fabrics that are sensitive to water, may wrinkle or shrink when washed in regular washing machines and are usually cleaned by professional dry cleaners. Dry cleaning is a process of removing soils from substrate, in this case textile, using a non-aqueous solvent. The most common solvent in

  6. Performance of a Big Scale Green House Type Dryer for Coffee Drying Process

    Sukrisno Widyotomo

    2014-12-01

    Full Text Available Dying is one of important steps in coffee processing to produce good quality. Greenhouse is one of artificial drying alternatives that potential for coffee drying method cause of cleans environmental friendly, renewable energy sources and chippers. Indonesian Coffee and Cocoa Research Institute has developed and testing a big scale greenhouse type dryer for fresh coffee cherries and wet parchment coffee drying process. Greenhouse has 24 m length, 18 m width, also 3 m high of the front side and 2 m high of the rear side. The maximum capacity of greenhouse is 40 tons fresh coffee cherries. Fiber Reinforced Plastic (FRP used as greenhouse roof that combined with I and C profile of steel. Fresh coffee cherries and wet parchment coffee from Robusta variety use as main materials in this research. The treatment of this research was 30 kg/m2, 60 kg/m2 and 90 kg/m2 for coffee density. String process has done by manual, two times a day in the morning and in the afternoon. As control, fresh coffee cherries and wet parchment coffee has dried by fully sun drying method. The result showed that a big scale greenhouse has heat drying efficiency between 29.9-58.2% depend on type and density of coffee treatments. On the full sunny day, greenhouse has produced maximum drying air temperature up to 52oC. In radiation cumulative level 4-5 kW-jam/m2 per day, 12.9-38.8 tons fresh coffee cherries or wet parchment coffee with 58-64% moisture content can be dried to 12% moisture content for 6 up to 14 days drying process. Slowly drying mechanism can be avoided negative effect to degradation of quality precursor compound. Capacity of the dryer can be raise and fungi can be reduce with application of controllable mechanical stirring in the greenhouse. Keywords: greenhouse, coffee, drying, quality

  7. Parametric modulation in the Taylor-Couette ferrofluid flow

    Singh, Jitender; Bajaj, Renu

    2008-01-01

    A parametric instability of the Taylor-Couette ferrofluid flow excited by a periodically oscillating magnetic field, has been investigated numerically. The Floquet analysis has been employed. It has been found that the modulation of the applied magnetic field affects the stability of the basic flow. The instability response has been found to be synchronous with respect to the frequency of periodically oscillating magnetic field.

  8. Scattering and depolarization of polarized neutrons in ferrofluids

    Balasoiu, M.; Dokukin, E.B.; Kozhevnikov, S.V.; Nikitenko, Y.V.

    1999-01-01

    On the SPN - 1 polarized neutron spectrometer at IBR -2 high - flux pulsed rector there were carried out preliminary measurements on transmission and polarization of a neutron beam passing through a magnetic colloidal system of Fe 3 O 4 particles in transformer oil and dodecane carriers. It was found that in the ferrofluids with magnetite particles exist, dependent on the particle volume concentration and the magnitude of the external magnetic field, effects of depolarization and nuclear - magnetic small angle scattering. (author)

  9. Modelling of drying processes of pharmaceutical granules. Pharmaceutical Sciences for the Future of Medicines

    Mortier, S.T.F.C.; Vedantam, S.; De Beer, T.

    Tablets are conventionally produced via consecutive batch process steps. Recent introduction of continuous process equipment is gaining industrial importance in pharmaceutics. Transition to continuous production requires improved understanding of all operations, necessitating the development...... of mechanistic models of multi‐phase systems which in the end allow process control. This contribution focuses on continuous fluidized bed drying of pharmaceutical wet granules. A stepwise approach is used in model development, starting with the drying behaviour of single granules. Experiments to determine...

  10. [Freeze drying process optimization of ginger juice-adjuvant for Chinese materia medica processing and stability of freeze-dried ginger juice powder].

    Yang, Chun-Yu; Guo, Feng-Qian; Zang, Chen; Cao, Hui; Zhang, Bao-Xian

    2018-02-01

    Ginger juice, a commonly used adjuvant for Chinese materia medica, is applied in processing of multiple Chinese herbal decoction pieces. Because of the raw materials and preparation process of ginger juice, it is difficult to be preserved for a long time, and the dosage of ginger juice in the processing can not be determined base on its content of main compositions. Ginger juice from different sources is hard to achieve consistent effect during the processing of traditional Chinese herbal decoction pieces. Based on the previous studies, the freeze drying of ginger juice under different shelf temperatures and vacuum degrees were studied, and the optimized freeze drying condition of ginger juice was determined. The content determination method for 6-gingerol, 8-gingerol, 10-gingerol and 6-shagaol in ginger juice and redissolved ginger juice was established. The content changes of 6-gingerol, 8-gingerol, 10-gingerol, 6-gingerol, 6-shagaol, volatile oil and total phenol were studied through the drying process and 30 days preservation period. The results showed that the freeze drying time of ginger juice was shortened after process optimization; the compositions basically remained unchanged after freeze drying, and there was no significant changes in the total phenol content and gingerol content, but the volatile oil content was significantly decreased( P <0.05). Within 30 days, the contents of gingerol, total phenol, and volatile oil were on the decline as a whole. This study has preliminarily proved the feasibility of freeze-drying process of ginger juice as an adjuvant for Chinese medicine processing. Copyright© by the Chinese Pharmaceutical Association.

  11. State-of-the-art dry active waste processing facility

    Hillmer, T.; Ingalsbe, H.; Alcorn, G.; Anderson, K.; Dahlen, D.

    1989-01-01

    Palo Verde Nuclear Generating Station (PVNGS) is operated by Arizona Public Service for a consortium of seven owners. The site consists of three identical single unit power plants. Each unit is a Combustion Engineering Series 80 pressurized water reactor (PWR) rated at 1270 Megawatts electric. The site is located 100 kilometers west of Phoenix, Arizona in the arid southwest desert region of the United States of America. Since the start up of Unit One in 1985, Palo Verde has aggressively pursued waste volume reduction. This includes a dry active waste (DAW) segregation program that locates and separates nonradioactive and reusable materials that have been mixed with the radioactive DAW. The DAW program is described in further detail in the paper

  12. Self-suspended permanent magnetic FePt ferrofluids

    Dallas, Panagiotis

    2013-10-01

    We present the synthesis and characterization of a new class of self-suspended ferrofluids that exhibit remanent magnetization at room temperature. Our system relies on the chemisorption of a thiol-terminated ionic liquid with very low melting point on the surface of L10 FePt nanoparticles. In contrast, all types of ferrofluids previously reported employ either volatile solvents as the suspending media or superparamagnetic iron oxide nanoparticles (that lacks permanent magnetization) as the inorganic component. The ferrofluids do not show any sign of flocculation or phase separation, despite the strong interactions between the magnetic nanoparticles due to the strong chemisorption of the ionic liquid as evidenced by Raman spectroscopy and thermal analysis. Composites with high FePt loading (40 and 70. wt%) exhibit a pseudo solid-like rheological behavior and high remanent magnetization values (10.1 and 12.8. emu/g respectively). At lower FePt loading (12. wt%) a liquid like behavior is observed and the remanent and saturation magnetization values are 3.5 and 6.2. emu/g, respectively. The magnetic and flow properties of the materials can be easily fine tuned by controlling the type and amount of FePt nanoparticles used. © 2013 Elsevier Inc.

  13. Immunomagnetic cell separation, imaging, and analysis using Captivate ferrofluids

    Jones, Laurie; Beechem, Joseph M.

    2002-05-01

    We have developed applications of CaptivateTM ferrofluids, paramagnetic particles (approximately 200 nm diameter), for isolating and analyzing cell populations in combination with fluorescence-based techniques. Using a microscope-mounted magnetic yoke and sample insertion chamber, fluorescent images of magnetically captured cells were obtained in culture media, buffer, or whole blood, while non-magnetically labeled cells sedimented to the bottom of the chamber. We combined this immunomagnetic cell separation and imaging technique with fluorescent staining, spectroscopy, and analysis to evaluate cell surface receptor-containing subpopulations, live/dead cell ratios, apoptotic/dead cell ratios, etc. The acquired images were analyzed using multi-color parameters, as produced by nucleic acid staining, esterase activity, or antibody labeling. In addition, the immunomagnetically separated cell fractions were assessed through microplate analysis using the CyQUANT Cell Proliferation Assay. These methods should provide an inexpensive alternative to some flow cytometric measurements. The binding capacities of the streptavidin- labled Captivate ferrofluid (SA-FF) particles were determined to be 8.8 nmol biotin/mg SA-FF, using biotin-4- fluorescein, and > 106 cells/mg SA-FF, using several cell types labeled with biotinylated probes. For goat anti- mouse IgG-labeled ferrofluids (GAM-FF), binding capacities were established to be approximately 0.2 - 7.5 nmol protein/mg GAM-FF using fluorescent conjugates of antibodies, protein G, and protein A.

  14. Temperature dependent viscosity of cobalt ferrite / ethylene glycol ferrofluids

    Kharat, Prashant B.; Somvanshi, Sandeep B.; Kounsalye, Jitendra S.; Deshmukh, Suraj S.; Khirade, Pankaj P.; Jadhav, K. M.

    2018-04-01

    In the present work, cobalt ferrite / ethylene glycol ferrofluid is prepared in 0 to 1 (in the step of 0.2) volume fraction of cobalt ferrite nanoparticles synthesized by co-precipitation method. The XRD results confirmed the formation of single phase spinel structure. The Raman spectra have been deconvoluted into individual Lorentzian peaks. Cobalt ferrite has cubic spinel structure with Fd3m space group. FT-IR spectra consist of two major absorption bands, first at about 586 cm-1 (υ1) and second at about 392 cm-1 (υ2). These absorption bands confirm the formation of spinel-structured cobalt ferrite. Brookfield DV-III viscometer and programmable temperature-controlled bath was used to study the relationship between viscosity and temperature. Viscosity behavior with respect to temperature has been studied and it is revealed that the viscosity of cobalt ferrite / ethylene glycol ferrofluids increases with an increase in volume fraction of cobalt ferrite. The viscosity of the present ferrofluid was found to decrease with increase in temperature.

  15. Drying of supercritical carbon dioxide with membrane processes

    Lohaus, Theresa; Scholz, Marco; Koziara, Beata; Benes, Nieck Edwin; Wessling, Matthias

    2015-01-01

    In supercritical extraction processes regenerating the supercritical fluid represents the main cost constraint. Membrane technology has potential for cost efficient regeneration of water-loaded supercritical carbon dioxide. In this study we have designed membrane-based processes to dehydrate

  16. Fabrication of Li2TiO3 pebbles by a freeze drying process

    Lee, Sang-Jin; Park, Yi-Hyun; Yu, Min-Woo

    2013-01-01

    Li 2 TiO 3 pebbles were successfully fabricated by using a freeze drying process. The Li 2 TiO 3 slurry was prepared using a commercial powder of particle size 0.5–1.5 μm and the pebble pre-form was prepared by dropping the slurry into liquid nitrogen through a syringe needle. The droplets were rapidly frozen, changing their morphology to spherical pebbles. The frozen pebbles were dried at −10 °C in vacuum. To make crack-free pebbles, some glycerin was employed in the slurry, and long drying time and a low vacuum condition were applied in the freeze drying process. In the process, the solid content in the slurry influenced the spheroidicity of the pebble green body. The dried pebbles were sintered at 1200 °C in an air atmosphere. The sintered pebbles showed almost 40% shrinkage. The sintered pebbles revealed a porous microstructure with a uniform pore distribution and the sintered pebbles were crushed under an average load of 50 N in a compressive strength test. In the present study, a freeze drying process for fabrication of spherical Li 2 TiO 3 pebbles is introduced. The processing parameters, such as solid content in the slurry and the conditions of freeze drying and sintering, are also examined

  17. Behavior of solid matters and heavy metals during conductive drying process of sewage sludge

    Jianping Luo

    2016-12-01

    Full Text Available Behavior of solid matters and heavy metals during conductive drying process of sewage sludge was evaluated in a sewage sludge disposal center in Beijing, China. The results showed most of solid matters could be retained in the dried sludge after drying. Just about 3.1% of solid matters were evaporated with steam mainly by the form of volatile fatty acids. Zn was the dominant heavy metal in the sludge, followed by Cu, Cr, Pb, Ni, Hg, and Cd. The heavy metals in the condensate were all below the detection limit except Hg. Hg in the condensate accounted for less than 0.1% of the total Hg. It can be concluded that most of the heavy metals are also retained in the dried sludge during the drying process, but their bioavailability could be changed significantly. The results are useful for sewage sludge utilization and its condensate treatment.

  18. Crispy banana obtained by the combination of a high temperature and short time drying stage and a drying process

    K. Hofsetz

    2005-06-01

    Full Text Available The effect of the high temperature and short time (HTST drying stage was combined with an air drying process to produce crispness in bananas. The fruit was dehydrated in an air drier for five minutes at 70°C and then immediately set at a HTST stage (130, 140, 150°C and 9, 12, 15 minutes and then at 70°C until water activity (a w was around 0.300. Crispness was evaluated as a function of water activity, using sensory and texture analyses. Drying kinetics was evaluated using the empirical Lewis model. Crispy banana was obtained at 140°C-12min and 150°C-15min in the HTST stage, with a w = 0.345 and a w = 0.363, respectively. Analysis of the k parameter (Lewis model suggests that the initial moisture content of the samples effects this parameter, overcoming the HTST effect. Results showed a relationship between sensory crispness, instrumental texture and the HTST stage.

  19. Structure and viscosity of a transformer oil-based ferrofluid under an external electric field

    Rajnak, M., E-mail: rajnak@saske.sk [Institute of Experimental Physics SAS, Watsonova 47, 04001 Košice (Slovakia); Faculty of Electrical Engineering and Informatics, Technical University of Košice, Letná 9, 04200 Košice (Slovakia); Timko, M.; Kopcansky, P.; Paulovicova, K. [Institute of Experimental Physics SAS, Watsonova 47, 04001 Košice (Slovakia); Tothova, J.; Kurimsky, J.; Dolnik, B.; Cimbala, R. [Faculty of Electrical Engineering and Informatics, Technical University of Košice, Letná 9, 04200 Košice (Slovakia); Avdeev, M.V. [Joint Institute for Nuclear Research, Joliot-Curie 6, Moscow region, 141980 Dubna (Russian Federation); Petrenko, V.I. [Joint Institute for Nuclear Research, Joliot-Curie 6, Moscow region, 141980 Dubna (Russian Federation); Taras Shevchenko Kyiv National University, Volodymyrska Street 64, 01601 Kyiv (Ukraine); Feoktystov, A. [Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85748 Garching (Germany)

    2017-06-01

    Various structural changes of ferrofluids have been intensively studied under external magnetic fields. In this work we present an experimental evidence of similar changes induced by an electric field. In the context of the electric field effect on ferrofluids structure, we studied a simple ferrofluid consisting of iron oxide nanoparticles coated with oleic acid and dispersed in transformer oil. The structural changes have been observed both on macroscopic and microscopic scale. We also demonstrate a remarkable impact of the electric field on the ferrofluid viscosity in relation to the reported structural changes. It was found that the electric field induced viscosity changes are analogous to the magnetoviscous effect. These changes and the electroviscous effect are believed to stem from the dielectric permittivity contrast between the iron oxide nanoparticles and transformer oil, giving rise to the effective electric polarization of the nanoparticles. It is highlighted that this electrorheological effect should be considered in studies of ferrofluids for high voltage engineering applications, as it can have impact on the thermomagnetic convection or the dielectric breakdown performance. - Highlights: • An experimental evidence of the electric field induced structural changes in a ferrofluid is presented. • An electroviscous effect in the transformer oil-based ferrofluid is shown. • The dielectric contrast between the particles and the carrier fluid is the key factor. • The potential impact on the thermomagnetic convection of ferrofluids in power transformers is highlighted.

  20. Mathematical modeling and determination of thermodynamic properties of jabuticaba peel during the drying process

    Cristian F. Costa

    2016-06-01

    Full Text Available ABSTRACT Jabuticaba is a fruit native of Brazil and, besides containing many nutritional qualities, it also has a good field for use in products such as flour for cakes and biscuits, juice, liqueur, jelly and others. This study aimed to model the drying kinetics and determine the thermodynamic properties of jabuticaba peel at different drying air temperatures. Ripe fruits of jabuticaba (Myrciaria jaboticaba were collected and pulped manually. Drying was carried out in a forced-air circulation oven with a flow of 5.6 m s-1 at temperatures of 40, 50, 60 and 70 °C. Six mathematical models commonly used to represent the drying process of agricultural products were fitted to the experimental data. The Arrhenius model was used to represent the drying constant as a function of temperature. The Midilli model showed the best fit to the experimental data of drying. The drying constant increased with the increment in drying temperature and promoted an activation energy of 37.29 kJ mol-1. Enthalpy and Gibbs free energy decreased with the increase in drying temperature, while entropy decreased and was negative.

  1. Criticality Safety Evaluation Report for the Cold Vacuum Drying (CVD) Facility's Process Water Handling System

    KESSLER, S.F.

    2000-01-01

    This report addresses the criticality concerns associated with process water handling in the Cold Vacuum Drying Facility. The controls and limitations on equipment design and operations to control potential criticality occurrences are identified

  2. Criticality safety evaluation report for the cold vacuum drying facility's process water handling system

    NELSON, J.V.

    1999-01-01

    This report addresses the criticality concerns associated with process water handling in the Cold Vacuum Drying Facility. The controls and limitations on equipment design and operations to control potential criticality occurrences are identified

  3. Preparation of polymer-organo clay nano composites through the spray drying process

    Bernardo, Paulo R.A.; Pessan, Luiz A.; Carvalho, Antonio J.F. de; Vidotti, Suel E.

    2011-01-01

    The objective of the work was the study and preparation of polymer nano composites with montmorillonite organo clays (MMT) through the spray drying process. A new technique was proposed and tested to obtaining polymer nano composites, based on the use of the spray drying process to produce a nano composite with high clay content. The process consisted of the following stages: clay intercalation in water solution, with after addition of polyvinyl alcohol (PVOH) and a hydro soluble polyester ionomer (GEROLPS20) as exfoliation agents; spray drying the mixture obtained; incorporation powder in EVOH, PET e PP matrix. The effects of exfoliation agent on morphological and thermal properties of the nano composites were studied by XRD, transmission electron microscopy (TEM) and TGA. The results demonstrate that the process of spray drying is an innovative way to obtain a nano composite with high clay content. (author)

  4. Digital holographic inspection for drying processes of paint films and ink dots

    Yokota, M.; Aoyama, F.

    2017-06-01

    Digital holographic techniques to investigate drying processes of both paint films and ink dot is presented. The proposed technique based on digital holographic interferometry can achieve both visualization of variations and analysis of dryness of paint films in the drying process by using phase changes between two subsequent reconstructed complex amplitudes of the reflected light from the film. To follow the drying processes, holograms are recorded at a constant time interval. Phase-shifting digital holography has been applied to analyze the dryness of commercial paints applied on the metal plate. For analysis of an ink dot having diameter of a few hundred micrometers, digital holographic microscopy is applied to evaluating the time history of dryness of ink dot in the drying process. This paper describes these holographic techniques applied to the commercially available paint and ink and presents some experimental results.

  5. Effects of annealing on the physical properties of therapeutic proteins during freeze drying process.

    Lim, Jun Yeul; Lim, Dae Gon; Kim, Ki Hyun; Park, Sang-Koo; Jeong, Seong Hoon

    2018-02-01

    Effects of annealing steps during the freeze drying process on etanercept, model protein, were evaluated using various analytical methods. The annealing was introduced in three different ways depending on time and temperature. Residual water contents of dried cakes varied from 2.91% to 6.39% and decreased when the annealing step was adopted, suggesting that they are directly affected by the freeze drying methods Moreover, the samples were more homogenous when annealing was adopted. Transition temperatures of the excipients (sucrose, mannitol, and glycine) were dependent on the freeze drying steps. Size exclusion chromatography showed that monomer contents were high when annealing was adopted and also they decreased less after thermal storage at 60°C. Dynamic light scattering results exhibited that annealing can be helpful in inhibiting aggregation and that thermal storage of freeze-dried samples preferably induced fragmentation over aggregation. Shift of circular dichroism spectrum and of the contents of etanercept secondary structure was observed with different freeze drying steps and thermal storage conditions. All analytical results suggest that the physicochemical properties of etanercept formulation can differ in response to different freeze drying steps and that annealing is beneficial for maintaining stability of protein and reducing the time of freeze drying process. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Characteristics and functionality of appetite-reducing thylakoid powders produced by three different drying processes.

    Östbring, Karolina; Sjöholm, Ingegerd; Sörenson, Henrietta; Ekholm, Andrej; Erlanson-Albertsson, Charlotte; Rayner, Marilyn

    2018-03-01

    Thylakoids, a chloroplast membrane extracted from green leaves, are a promising functional ingredient with appetite-reducing properties via their lipase-inhibiting effect. Thylakoids in powder form have been evaluated in animal and human models, but no comprehensive study has been conducted on powder characteristics. The aim was to investigate the effects of different isolation methods and drying techniques (drum-drying, spray-drying, freeze-drying) on thylakoids' physicochemical and functional properties. Freeze-drying yielded thylakoid powders with the highest lipase-inhibiting capacity. We hypothesize that the specific macromolecular structures involved in lipase inhibition were degraded to different degrees by exposure to heat during spray-drying and drum-drying. We identified lightness (Hunter's L-value), greenness (Hunter's a-value), chlorophyll content and emulsifying capacity to be correlated to lipase-inhibiting capacity. Thus, to optimize the thylakoids functional properties, the internal membrane structure indicated by retained green colour should be preserved. This opens possibilities to use chlorophyll content as a marker for thylakoid functionality in screening processes during process optimization. Thylakoids are heat sensitive, and a mild drying technique should be used in industrial production. Strong links between physicochemical parameters and lipase inhibition capacity were found that can be used to predict functionality. The approach from this study can be applied towards production of standardized high-quality functional food ingredients. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  7. Nutritive value of palm oil sludge fermented with Aspergillus niger after therma1 drying process

    T Purwadaria

    1999-12-01

    Full Text Available Solid substrate fermentation by Aspergillus niger has been carried out to improve the nutritive value of palm oil sludge (POS. POS was fermented aerobically for four days in a fermentor chambers (28°C, RH 80%, with 60% moisture content Some of the product was further incubated anaerobically for 2 days at 28°C. Both products from aerobic and anaerobic fermentation processes were dried by various methods, i.e. sunlight, oven at 60°C, oven with blower at 40°C, at the moisture content less than 11%. Results of the drying methods were also compared with the fresh fermented product. Statistic analysis using factorial design (2 x 4 showed that there was no interaction between kind of fermentation processes (aerobic and anaerobic and drying methods (fresh, sunlight, oven 60°C, and blower 40°C for almost all parameters except total a-amino acid content Significant results (p<0.05 were obtained on the drying methods for parameters of crude protein, true protein, in vitro dry matter and protein digestibilities, and mannanase and cellulase activities. There were no significant results between treatments in the crude fiber analysis and soluble nitrogen content Significant results also did not occur between treatment of aerob and anaerob fermentation processes for almost all parameters except for dry matter digestibilities. Results from true protein and in vitro digestibilities show that the fresh fermented product has the best nutritive value, while product dried by sunlight was best among other drying processes. Results from in vivo of protein and energy digestibilities show that there were better metabolizable energy and protein for product with aerobic process and dried with oven and blower treatments, while sunlight drying was best for product processed in anaerobic condition. Although fresh fermented product gave better result from in vitro digestibilities and enzyme activity analyses, for some reasons (easy handling and preservation sunlight

  8. Monitoring and Optimization of the Process of Drying Fruits and Vegetables Using Computer Vision: A Review

    Flavio Raponi

    2017-11-01

    Full Text Available An overview is given regarding the most recent use of non-destructive techniques during drying used to monitor quality changes in fruits and vegetables. Quality changes were commonly investigated in order to improve the sensory properties (i.e., appearance, texture, flavor and aroma, nutritive values, chemical constituents and mechanical properties of drying products. The application of single-point spectroscopy coupled with drying was discussed by virtue of its potentiality to improve the overall efficiency of the process. With a similar purpose, the implementation of a machine vision (MV system used to inspect foods during drying was investigated; MV, indeed, can easily monitor physical changes (e.g., color, size, texture and shape in fruits and vegetables during the drying process. Hyperspectral imaging spectroscopy is a sophisticated technology since it is able to combine the advantages of spectroscopy and machine vision. As a consequence, its application to drying of fruits and vegetables was reviewed. Finally, attention was focused on the implementation of sensors in an on-line process based on the technologies mentioned above. This is a necessary step in order to turn the conventional dryer into a smart dryer, which is a more sustainable way to produce high quality dried fruits and vegetables.

  9. Physical quality of grains subjected to moistening and drying processes for marketing

    Paulo C. Coradi

    Full Text Available ABSTRACT The aim was to evaluate the physical quality of conventional and transgenic corn grains, through drying and wetting processes for marketing. The experimental design was completely randomized in a factorial scheme (7 x 3 x 2, corresponding to seven drying times (0, 20, 40, 60, 80, 100 and 120 min, three temperatures of the drying air (80, 100 and 120 °C and two hybrids of corn (conventional AG 1051 and transgenic Herculex@ 30S31H. Grain drying was held in convection oven with forced air ventilation while the wetting was done in a B.O.D chamber. The water movement in the grain, the volume and the electrical conductivity were evaluated periodically. The results showed that the transgenic corn grain reduced the negative effects of drying and moistening on the physical quality. The increase in drying air temperature accelerated the physical deterioration of conventional and transgenic corn grains. The increase in water content by the moistening process caused losses in grain physical quality, similar to the drying process, for both the conventional and transgenic corn grains.

  10. Evaluation of Heat Flux Measurement as a New Process Analytical Technology Monitoring Tool in Freeze Drying.

    Vollrath, Ilona; Pauli, Victoria; Friess, Wolfgang; Freitag, Angelika; Hawe, Andrea; Winter, Gerhard

    2017-05-01

    This study investigates the suitability of heat flux measurement as a new technique for monitoring product temperature and critical end points during freeze drying. The heat flux sensor is tightly mounted on the shelf and measures non-invasively (no contact with the product) the heat transferred from shelf to vial. Heat flux data were compared to comparative pressure measurement, thermocouple readings, and Karl Fischer titration as current state of the art monitoring techniques. The whole freeze drying process including freezing (both by ramp freezing and controlled nucleation) and primary and secondary drying was considered. We found that direct measurement of the transferred heat enables more insights into thermodynamics of the freezing process. Furthermore, a vial heat transfer coefficient can be calculated from heat flux data, which ultimately provides a non-invasive method to monitor product temperature throughout primary drying. The end point of primary drying determined by heat flux measurements was in accordance with the one defined by thermocouples. During secondary drying, heat flux measurements could not indicate the progress of drying as monitoring the residual moisture content. In conclusion, heat flux measurements are a promising new non-invasive tool for lyophilization process monitoring and development using energy transfer as a control parameter. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  11. Spray-drying nanocapsules in presence of colloidal silica as drying auxiliary agent: formulation and process variables optimization using experimental designs.

    Tewa-Tagne, Patrice; Degobert, Ghania; Briançon, Stéphanie; Bordes, Claire; Gauvrit, Jean-Yves; Lanteri, Pierre; Fessi, Hatem

    2007-04-01

    Spray-drying process was used for the development of dried polymeric nanocapsules. The purpose of this research was to investigate the effects of formulation and process variables on the resulting powder characteristics in order to optimize them. Experimental designs were used in order to estimate the influence of formulation parameters (nanocapsules and silica concentrations) and process variables (inlet temperature, spray-flow air, feed flow rate and drying air flow rate) on spray-dried nanocapsules when using silica as drying auxiliary agent. The interactions among the formulation parameters and process variables were also studied. Responses analyzed for computing these effects and interactions were outlet temperature, moisture content, operation yield, particles size, and particulate density. Additional qualitative responses (particles morphology, powder behavior) were also considered. Nanocapsules and silica concentrations were the main factors influencing the yield, particulate density and particle size. In addition, they were concerned for the only significant interactions occurring among two different variables. None of the studied variables had major effect on the moisture content while the interaction between nanocapsules and silica in the feed was of first interest and determinant for both the qualitative and quantitative responses. The particles morphology depended on the feed formulation but was unaffected by the process conditions. This study demonstrated that drying nanocapsules using silica as auxiliary agent by spray drying process enables the obtaining of dried micronic particle size. The optimization of the process and the formulation variables resulted in a considerable improvement of product yield while minimizing the moisture content.

  12. Kinetics of varnish long-term drying process monitored by a heterogeneous optical sensor system

    Saccon, F A M; De Oliveira, F M D R; Ribas, M O; Zambianchi, P Jr; Muller, M; Fabris, J L

    2013-01-01

    The drying process of an acrylic varnish film was monitored over 24 h by a heterogeneous optical sensor system. The system employs a fibre optic transducer based on Bragg gratings and optical coherence tomography, operating respectively around 1.55 and 1.3 µm. The sensor is able to provide information about the temporal evolution of temperature, mechanical deformation, thickness and average refractive index of the coating during the drying process. Resolutions for these optically measured parameters are 0.05 °C (temperature), 0.5 µε (strain), 1.5 µm (thickness) and 0.004 (refractive index). Besides, the sensor can detect the growth of a surface dry skin and supply information about the film bulk uniformity. A model for the mass loss of solvent as the drying process evolves is also discussed. (paper)

  13. Pulsed high-density plasmas for advanced dry etching processes

    Banna, Samer; Agarwal, Ankur; Cunge, Gilles; Darnon, Maxime; Pargon, Erwine; Joubert, Olivier

    2012-01-01

    Plasma etching processes at the 22 nm technology node and below will have to satisfy multiple stringent scaling requirements of microelectronics fabrication. To satisfy these requirements simultaneously, significant improvements in controlling key plasma parameters are essential. Pulsed plasmas exhibit considerable potential to meet the majority of the scaling challenges, while leveraging the broad expertise developed over the years in conventional continuous wave plasma processing. Comprehending the underlying physics and etching mechanisms in pulsed plasma operation is, however, a complex undertaking; hence the full potential of this strategy has not yet been realized. In this review paper, we first address the general potential of pulsed plasmas for plasma etching processes followed by the dynamics of pulsed plasmas in conventional high-density plasma reactors. The authors reviewed more than 30 years of academic research on pulsed plasmas for microelectronics processing, primarily for silicon and conductor etch applications, highlighting the potential benefits to date and challenges in extending the technology for mass-production. Schemes such as source pulsing, bias pulsing, synchronous pulsing, and others in conventional high-density plasma reactors used in the semiconductor industry have demonstrated greater flexibility in controlling critical plasma parameters such as ion and radical densities, ion energies, and electron temperature. Specifically, plasma pulsing allows for independent control of ion flux and neutral radicals flux to the wafer, which is key to eliminating several feature profile distortions at the nanometer scale. However, such flexibility might also introduce some difficulty in developing new etching processes based on pulsed plasmas. Therefore, the main characteristics of continuous wave plasmas and different pulsing schemes are compared to provide guidelines for implementing different schemes in advanced plasma etching processes based on

  14. 7 CFR 319.56-11 - Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes.

    2010-01-01

    ... QUARANTINE NOTICES Fruits and Vegetables § 319.56-11 Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes. (a) Dried, cured, or processed fruits and vegetables (except frozen fruits and... 7 Agriculture 5 2010-01-01 2010-01-01 false Importation of dried, cured, or processed fruits...

  15. Dry etch challenges for CD shrinkage in memory process

    Matsushita, Takaya; Matsumoto, Takanori; Mukai, Hidefumi; Kyoh, Suigen; Hashimoto, Kohji

    2015-03-01

    Line pattern collapse attracts attention as a new problem of the L&S formation in sub-20nm H.P feature. Line pattern collapse that occurs in a slight non-uniformity of adjacent CD (Critical dimension) space using double patterning process has been studied with focus on micro-loading effect in Si etching. Bias RF pulsing plasma etching process using low duty cycle helped increase of selectivity Si to SiO2. In addition to the effect of Bias RF pulsing process, the thin mask obtained from improvement of selectivity has greatly suppressed micro-loading in Si etching. However it was found that micro-loading effect worsen again in sub-20nm space width. It has been confirmed that by using cycle etch process to remove deposition with CFx based etching micro-loading effect could be suppressed. Finally, Si etching process condition using combination of results above could provide finer line and space without "line pattern collapse" in sub-20nm.

  16. Current problems of raw fish material processing while manufacturing dried products

    Yashonkov A. A.

    2017-09-01

    Full Text Available The substantiation for using techniques of fish raw material canning has been presented, raw fish being caught or farmed in aquaculture. The main problems in raw fish canning have been reviewed, including significant reduction in thermolabile vitamins in the ultimate product as compared with the raw material due to the thermal processing. Promising canning technique – vacuum drying – has been proposed. This technique makes possible to reduce the temperature of thermal processing down to 50…55 °С and significantly enlarge preservation of thermolabile vitamins from the raw fish. Sampling of raw materials, semi-finished products, finished products, including preparation for analysis has been conducted by standard methods. Disadvantages of this way have been found, it is low energy efficiency of the process. The way to intensify the vacuum drying of aquatic organisms has been proposed based on the method of preliminary pore-forming due to augmenting the area of moisture evaporation. The design of the pilot plant has been proposed in order to research the process of pore forming and vacuum drying. Target species for processing have been suggested. They are as follows: Azov goby (fillet for food products and Black Sea sprat for feeds. The recipes of the feed mixture for granulated floating food for trout have been developed. The results of the first series of the pilot research have been provided. The experiments have proved that preliminary pore forming immediately before vacuum drying makes possible to enlarge the surface area of moisture evaporation by 15…25 %. By processing photomicrographs of sections by means of a special software the authors have got the results demonstrating that when manufacturing dried products by pore forming and drying under pressure 10 kPa the pore take 35...38 % of the inner volume of the product and with drying under pressure 10 kPa – only 18...21 %, and when drying under the atmospheric pressure – 11...13 %.

  17. Study of the flash drying of the residue from soymilk processing - "okara"

    Regina Kitagawa Grizotto

    2011-09-01

    Full Text Available The objective of this research project was to study the drying of soymilk residue in a pneumatic flash dryer, using response Surface Methodology (RSM, and to evaluate the quality of the dried residue. Soymilk residue, also known as okara, was provided by a Brazilian soymilk factory. RSM showed that for a 120 second drying cycle, the lower the residue moisture contents (y obtained, the higher the recirculation rates (x1, regardless of the air drying temperature (x2, and it could be expressed by the equation y = 7.072 - 7.92x1, with R² = 92,92%. It is possible to obtain okara with 10% of moisture (dwb under the condition x1=1.25, equivalent to RR = 61%, with air drying temperatures ranging from 252 °C to 308 °C. The dried okara obtained through Central Compound Rotational Design (CCRD presented a centesimal composition similar to the okara dried in a tray dryer, known as the original okara. There were significant variations (p < 0.05 in the Emulsifying Capacity (EC, Emulsion Stability (ES and Protein Solubility (PS between the dehydrated residues obtained. It was concluded that the flash drying of okara is technically feasible and that the physicochemical composition of the residue was not altered; on the contrary, the process promoted a positive effect on the technological functional properties.

  18. Dry anaerobic conversion of municipal solid wastes: Dranco process

    Six, W.; De Baere, L.

    1992-01-01

    The DRANCO process was developed for the conversion of solid organic wastes, specifically the organic fraction of municipal solid waste (MSW), to energy and a humus-like final product, called Humotex. The DRANCO process can be compared to landfill gas production accelerated by a factor 1000. A Dranco installation with a digester of 808 cubic meters treating 10,500 tonnes of source separated waste per year is under construction in Brecht, Belgium. A description of the plant is presented. A 56 cubic meters demonstration plant, using mixed garbage as feedstock, has been in operation for several years in Gent, Belgium. The operating temperature in the digester is 55 degrees C and the total solids concentration is about 32%. The gas production process is finalized in 3 weeks. The final product is de-watered and further stabilized in 10 days during aerobic post-treatment. Humotex is free of pathogens. Low concentrations of heavy metals can only be obtained through the collection of sorted garbage. The Dranco process is suitable for the digestion of source separated wastes such as vegetables, fruit, garden and non-recyclable paper wastes

  19. The potato chips and dry mashed as products of potato rational processing

    A. Mazur

    2015-05-01

    Full Text Available Introduction. The percentage of potato processing for food products in the former Soviet Union decreased to 1%, at the same time in some countries of Europe and the USA the share of potato processing is 60-80%. Numerous works have shown the economic feasibility of potato processing for food products. Materials and methods. In laboratory and industrial conditions of the open stock company «Mashpishcheprod» (Maryina Gorka, Minsk region, Belarus researches have been conducted on increase of efficiency of technological processes potato processing. Sampling, preparation and conducting of tests were performed by standard and special methods of analysis. Results and discussion. Potato varieties suitable for the production of dry mashed potatoes and potatocrisps have been determined, acclimatization before processing ensures minimumthe content of the reducing sugars, which provide high quality of the finished product. Studies have shown that the process of kneading potato at temperatures close to cooking temperature is optimal, in which the process of destruction cells is hardly taking place. Pneumatic dryers for drying boiled potato provide high product quality due to the low temperature of heating and short contact of a powdered product with a drying agent. However, the contents of damaged cells in the finished product do not exceed 1.3-2.6%. The optimum modes and parameters of potato crisps production have been defined, the processes of cutting, blanching, treatment with salt, drying and roasting have been scientifically grounded, that provide a finished product with fat content not more than 27.7%. Conclusion. Economic expediency of processing the following varieties of potato Desire, Temp, Synthesis for dry mashed potato and potato crisps has been proved. The processes of kneading and drying potato are decisive stages of the processing, because they determine the number of destroyedcells in the finished product. Optimal parameters of production

  20. Innovative application of the moisture analyzer for determination of dry mass content of processed cheese

    Kowalska, Małgorzata; Janas, Sławomir; Woźniak, Magdalena

    2018-04-01

    The aim of this work was the presentation of an alternative method of determination of the total dry mass content in processed cheese. The authors claim that the presented method can be used in industry's quality control laboratories for routine testing and for quick in-process control. For the test purposes both reference method of determination of dry mass in processed cheese and moisture analyzer method were used. The tests were carried out for three different kinds of processed cheese. In accordance with the reference method, the sample was placed on a layer of silica sand and dried at the temperature of 102 °C for about 4 h. The moisture analyzer test required method validation, with regard to drying temperature range and mass of the analyzed sample. Optimum drying temperature of 110 °C was determined experimentally. For Hochland cream processed cheese sample, the total dry mass content, obtained using the reference method, was 38.92%, whereas using the moisture analyzer method, it was 38.74%. An average analysis time in case of the moisture analyzer method was 9 min. For the sample of processed cheese with tomatoes, the reference method result was 40.37%, and the alternative method result was 40.67%. For the sample of cream processed cheese with garlic the reference method gave value of 36.88%, and the alternative method, of 37.02%. An average time of those determinations was 16 min. Obtained results confirmed that use of moisture analyzer is effective. Compliant values of dry mass content were obtained for both of the used methods. According to the authors, the fact that the measurement took incomparably less time for moisture analyzer method, is a key criterion of in-process control and final quality control method selection.

  1. MODEL REPRESENTATION OF THE SPRAY DRYING PROCESS OF THE DISTILLERY STILLAGE FILTRATE BASED ON NAVIERSTOKES EQUATIONS

    A. A. Shevtsov

    2015-01-01

    Full Text Available Spray drying of solutions and suspensions is among the most common methods of producing a wide range of powdered products in chemical, food and pharmaceutical industries. For the drying of heat-sensitive materials, which is fully applicable to the distillery stillage filtrate continuous-flow type of contact of drying agent and the solution droplets is examined. Two-phase simulation method of computational hydrodynamics in a stationary state for studying the process of drying of the distillery stillage filtrate in the pilot spray dryer under the following assumptions was used. The components form an ideal mixture, the properties of which are calculated directly from the properties of the components and their proportions. The droplets were presented in spherical form. The density and specific heat of the solution and the coefficient of vapors diffusion in the gas phase remained unchanged. To solve the heat exchange equations between the drying agent and the drops by the finite volume method the software package ANSYS CFX was used. The bind between the two phases was established by Navier-Stokes equations. The continuous phase (droplets of the distillery stillage filtrate was described by the k-ε turbulence model. The results obtained showed that the interaction of "drop-wall" causes a significant change of velocity, temperature and humidity both of a drying agent and the product particles. The behavior of the particles by spraying, collision with walls and deposition of the finished product allowed to determine the dependence of physical parameters of the drying process, of the geometric dimensions of the dryer. Comparison of simulation results with experimental data showed satisfactory convergence of the results: for the temperature of the powder 10% its humidity of 12% and temperature of the spent drying agent at the outlet from the drier of 13%. The possibility of using the model in the spray dryers designing, and control of the drying process

  2. Fiber Bragg Grating Sensor to Monitor Stress Kinetics in Drying Process of Commercial Latex Paints

    Ivo de Lourenço

    2010-05-01

    Full Text Available In this paper, we report a study about the application of packaged fiber Bragg gratings used as strain sensors to monitor the stress kinetics during the drying process of commercial latex paints. Three stages of drying with distinct mechanical deformation and temporal behaviors were identified for the samples, with mechanical deformation from 15 μm to 21 μm in the longitudinal film dimension on time intervals from 370 to 600 minutes. Drying time tests based on human sense technique described by the Brazilian Technical Standards NBR 9558 were also done. The results obtained shows that human sense technique has a limited perception of the drying process and that the optical measurement system proposed can be used to characterize correctly the dry-through stage of paint. The influence of solvent (water addition in the drying process was also investigated. The paint was diluted with four parts paint and one part water (80% paint, and one part paint and one part water (50% paint. It was observed that the increase of the water ratio mixed into the paint decreases both the mechanical deformation magnitude and the paint dry-through time. Contraction of 5.2 μm and 10.4 μm were measured for concentrations of 50% and 80% of paint in the mixture, respectively. For both diluted paints the dry-through time was approximately 170 minutes less than undiluted paint. The optical technique proposed in this work can contribute to the development of new standards to specify the drying time of paint coatings.

  3. Slip effects on MHD flow and heat transfer of ferrofluids over a moving flat plate

    Ramli, Norshafira; Ahmad, Syakila; Pop, Ioan

    2017-08-01

    In this study, the problem of MHD flow and heat transfer of ferrofluids over a moving flat plate with slip effect and uniform heat flux is considered. The governing ordinary differential equations are solved via shooting method. The effect of slip parameter on the dimensionless velocity, temperature, skin friction and Nusselt numbers are numerically studied for the three selected ferroparticles; magnetite (Fe3O4), cobalt ferrite (CoFe2O4) and Mn-Zn ferrite (Mn-ZnFe2O4) with water-based fluid. The results indicate that dual solutions exist for a plate moving towards the origin. It is found that the slip process delays the boundary layer separation. Moreover, the velocity and thermal boundary-layer thicknesses decrease in the first solution while increase with the increase of the value of slip parameters in second solution.

  4. Mathematical modeling for the annatto (Bixa orellana L. seed drying process

    Dyego da Costa Santos

    2013-09-01

    Full Text Available The pigment extraction process using annatto (Bixa orellana L. seed produces a large amount of seed waste. Although most of these seeds are discarded, a number of studies report promising results with their use in animal feed. The good fiber content also suggests human nutrition applications, with possible incorporation in dietary foods. In the present study, annatto seeds derived from color extraction were dried, with and without the layer of oil left over from the process. Seeds were dried at 40, 50, 60 and 70 °C. Drying data were fitted to the Diffusion Approximation, Two Term, Midilli, Page and Thompson models. Drying was carried out up to a moisture content of approximately 5% wet basis. All the models studied exhibited adequate fit to the drying kinetics data of the annatto seeds, with coefficients of determination above 0.98 and root mean squared error (RMSE below 1.0. Seeds with oil had longer drying times at 40 and 50 °C and shorter times at 60 and 70 °C. The coefficients of diffusion showed values between 2.67 x 10-11 and 9.50 x 10-11 m² s-1 and between 2.7 x 10-11 and 6.21 x 10-11 m² s-1, while activation energies for liquid diffusions were 38.04 and 23.52 kJ mol-1, for residual seed drying with and without oil, respectively.

  5. Development of a Population Balance Model of a pharmaceutical drying process and testing of solution methods

    Mortier, Séverine Thérèse F.C.; Gernaey, Krist; De Beer, Thomas

    2013-01-01

    Drying is frequently used in the production of pharmaceutical tablets. Simulation-based control strategy development for such a drying process requires a detailed model. First, the drying of wet granules is modelled using a Population Balance Model. A growth term based on a reduced model was used......, which describes the decrease of the moisture content, to follow the moisture content distribution for a batch of granules. Secondly, different solution methods for solving the PBM are compared. The effect of grid size (discretization methods) is analyzed in terms of accuracy and calculation time. All...

  6. Temperature and humidity response in the curing and drying process for Burley tobacco

    Edilson Daniel Gomez-Herrera

    2016-12-01

    Full Text Available This paper present the methodology development used for characterization and implementation of a control and automation of a camera for curing and drying of Burley tobacco, done with the purpose of analyzing its three stages: yellowing, color fixing and drying.As first step, the paper gives to know the process that is important for air curing of Burley tobacco. As second step, analysis of heating and humidification of system is presented, for determinate the most adequate control system for maintenance the ideal conditions for curing and drying of Burley. Results are presented through figures and tables.

  7. Selected chemical compounds in firm and mellow persimmon fruit before and after the drying process.

    Senica, Mateja; Veberic, Robert; Grabnar, Jana Jurhar; Stampar, Franci; Jakopic, Jerneja

    2016-07-01

    Persimmon is a seasonal fruit and only available in fresh form for a short period of each year. In addition to freezing, drying is the simplest substitute for the fresh fruit and accessible throughout the year. The effect of mellowing and drying was evaluated in 'Tipo' persimmon, an astringent cultivar. 'Tipo' firm fruit contained high levels of tannins (1.1 mg g(-1) DW), which were naturally decreased to 0.2 mg g(-1) DW after mellowing. The drying process greatly impacted the contents of carotenoids, total phenols, individual phenolics, tannins, organic acids, sugars and colour parameters in firm and mellow fruit. The reduction of tannins, phenolic compounds and organic acids were accompanied by the increase of sugars and carotenoids, improving the colour of the analysed samples. These results showed that the drying process improved the quality of persimmon products and extended their shelf life. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  8. Retention of ferrofluid aggregates at the target site during magnetic drug targeting

    Asfer, Mohammed, E-mail: asfer786@gmail.com [School of Engineering and Technology, BML Munjal University, Haryana (India); Saroj, Sunil Kumar [Department of Mechanical Engineering, IIT Kanpur, Kanpur (India); Panigrahi, Pradipta Kumar, E-mail: panig@iitk.ac.in [Department of Mechanical Engineering, IIT Kanpur, Kanpur (India)

    2017-08-15

    Highlights: • The present in vitro work reports the retention dynamics of ferrofluid aggregates at the target site against a bulk flow of DI water inside a micro capillary during magnetic drug targeting. • The recirculation zone at the downstream of the aggregate is found to be a function of aggregate height, Reynolds number and the degree of surface roughness of the outer boundary of the aggregate. • The reported results of the present work can be used as a guideline for the better design of MDT technique for in vivo applications. - Abstract: The present study reports the retention dynamics of a ferrofluid aggregate localized at the target site inside a glass capillary (500 × 500 µm{sup 2} square cross section) against a bulk flow of DI water (Re = 0.16 and 0.016) during the process of magnetic drug targeting (MDT). The dispersion dynamics of iron oxide nanoparticles (IONPs) into bulk flow for different initial size of aggregate at the target site is reported using the brightfield visualization technique. The flow field around the aggregate during the retention is evaluated using the µPIV technique. IONPs at the outer boundary experience a higher shear force as compared to the magnetic force, resulting in dispersion of IONPs into the bulk flow downstream to the aggregate. The blockage effect and the roughness of the outer boundary of the aggregate resulting from chain like clustering of IONPs contribute to the flow recirculation at the downstream region of the aggregate. The entrapment of seeding particles inside the chain like clusters of IONPs at the outer boundary of the aggregate reduces the degree of roughness resulting in a streamlined aggregate at the target site at later time. The effect of blockage, structure of the aggregate, and disturbed flow such as recirculation around the aggregate are the primary factors, which must be investigated for the effectiveness of the MDT process for in vivo applications.

  9. MODEL OF A PROCESS FOR DRYING Eucalyptus spp AT HIGH TEMPERATURES

    P. C. C. PINHEIRO

    1998-12-01

    Full Text Available A mathematical model of a process for drying of Eucalyptus spp is presented. This model was based on fundamental heat and mass transfer equations and it was numerically solved using a segregated finite volume method. Software in the FORTRAN language was developed to solve the mathematical model. The kinetic parameters of drying for Eucalyptus spp were experimentally obtained by isothermal thermogravimetry (TG. The theoretical results generated using the mathematical model were validated by experimental data.

  10. Dry uranium tetrafluoride process preparation using the uranium hexafluoride reconversion process effluents

    Silva Neto, Joao Batista da

    2008-01-01

    It is a well known fact that the use of uranium tetrafluoride allows flexibility in the production of uranium suicide and uranium oxide fuel. To its obtention there are two conventional routes, the one which reduces uranium from the UF 6 hydrolysis solution with stannous chloride, and the hydro fluorination of a solid uranium dioxide. In this work we are introducing a third and a dry way route, mainly utilized to the recovery of uranium from the liquid effluents generated in the uranium hexafluoride reconversion process, at IPEN/CNEN-SP. Working in the liquid phase, this route comprises the recuperation of ammonium fluoride by NH 4 HF 2 precipitation. Working with the solid residues, the crystallized bifluoride is added to the solid UO 2 , which comes from the U mini plates recovery, also to its conversion in a solid state reaction, to obtain UF 4 . That returns to the process of metallic uranium production unity to the U 3 Si 2 obtention. This fuel is considered in IPEN CNEN/SP as the high density fuel phase for IEA-R1m reactor, which will replace the former low density U 3 Si 2 -Al fuel. (author)

  11. Quality by Design approach to spray drying processing of crystalline nanosuspensions.

    Kumar, Sumit; Gokhale, Rajeev; Burgess, Diane J

    2014-04-10

    Quality by Design (QbD) principles were explored to understand spray drying process for the conversion of liquid nanosuspensions into solid nano-crystalline dry powders using indomethacin as a model drug. The effects of critical process variables: inlet temperature, flow and aspiration rates on critical quality attributes (CQAs): particle size, moisture content, percent yield and crystallinity were investigated employing a full factorial design. A central cubic design was employed to generate the response surface for particle size and percent yield. Multiple linear regression analysis and ANOVA were employed to identify and estimate the effect of critical parameters, establish their relationship with CQAs, create design space and model the spray drying process. Inlet temperature was identified as the only significant factor (p value dried nano-crystalline powders. Aspiration and flow rates were identified as significant factors affecting yield (p value dried at higher inlet temperatures had lower moisture compared to those dried at lower inlet temperatures. Published by Elsevier B.V.

  12. Electromagnetic Linear Vibration Energy Harvester Using Sliding Permanent Magnet Array and Ferrofluid as a Lubricant

    Song Hee Chae

    2017-09-01

    Full Text Available We present an electromagnetic linear vibration energy harvester with an array of rectangular permanent magnets as a springless proof mass. Instead of supporting the magnet assembly with spring element, ferrofluid has been used as a lubricating material. When external vibration is applied laterally to the harvester, magnet assembly slides back and forth on the channel with reduced friction and wear due to ferrofluid, which significantly improves the long-term reliability of the device. Electric power is generated across an array of copper windings formed at the bottom of the aluminum housing. A proof-of-concept harvester has been fabricated and tested with a vibration exciter at various input frequencies and accelerations. For the device where 5 μL of ferrofluid was used for lubrication, maximum output power of 493 μW has been generated, which was 4.37% higher than that without ferrofluid. Long-term reliability improvement due to ferrofluid lubrication has also been verified. For the device with ferrofluid, 1.02% decrease of output power has been observed, in contrast to 59.73% decrease of output power without ferrofluid after 93,600 cycles.

  13. Polymer degradation in reactive ion etching and its possible application to all dry processes

    Hiraoka, H.; Welsh, L.W. Jr.

    1981-01-01

    Dry etching processes involving CF 4 -plasma and reactive ion etching become increasingly important for microcircuit fabrication techniques. In these techniques polymer degradation and etch resistance against reactive species like F atoms and CF 3 + ions are the key factors in the processes. It is well-known that classical electron beam resists like poly(methyl methacrylate) and poly(1-butene sulfone) are not suitable for dry etching processes because they degrade rapidly under these etching conditions. In order to find a correlation of etching rate and polymer structures the thickness loss of polymer films have been measured for a variety of polymer films in reactive ion etching conditions, where CF 3 + ions are the major reactive species with an accelerating potential of 500 volts. Because of its high CF 4 -plasma and reactive ion etch resistance, and because of its high electron beam sensitivity, poly(methacrylonitrile) provides a positive working electron beam resist uniquely suited for all dry processes. (author)

  14. A comprehensive sensitivity and uncertainty analysis of a milk drying process

    Ferrari, A.; Gutiérrez, S.; Sin, G.

    2015-01-01

    A simple steady state model of a milk drying process was built to help process understanding. It involves a spray chamber and also internal/external fluid beds. The model was subjected to a statistical analysis for quality assurance using sensitivity analysis (SA) of inputs/parameters, identifiab......A simple steady state model of a milk drying process was built to help process understanding. It involves a spray chamber and also internal/external fluid beds. The model was subjected to a statistical analysis for quality assurance using sensitivity analysis (SA) of inputs...... technique. SA results provide evidence towards over-parameterization in the model, and the chamber inlet dry bulb air temperature was the variable (input) with the highest sensitivity. IA results indicated that at most 4 parameters are identifiable: two from spray chamber and one from each fluid bed dryer...

  15. Degradability of dry matter and crude protein of dry grains and wet grain silages from different processing corn hybrids (Zea mays)

    Wagner dos Reis; Ciniro Costa; Paulo Roberto de Lima Meirelles; Marina Gabriela Berchiol da Silva; Marco Aurélio Factori; Janaína Conte Hadlich; Kátia de Oliveira; Erikelly Aline Ribeiro de Santana; Cristiano Magalhães Pariz; Josineudson Augusto II de Vasconcelos Silva

    2013-01-01

    The objective of this work was to evaluate the effect of processing two corn hybrids conserved, dry and humid grains, the dry matter (DM) and crude protein (CP) degradability in situ. The particle size was determined and difference was verified in MGD (Medium Geometric Diameter) of processed ingredients. Three sheep were used with rumen canulated, in a completely randomized design, using a factorial outline 2 x 2 x 3, being two corn hybrid, two conservation methods and three processing forms ...

  16. The use of ferrofluids for heat removal: Advantage or disadvantage?

    Krauzina, Marina T., E-mail: krauzina@psu.ru [Faculty of Physics, Perm State University, 15 Bukirev Street, Perm 614990 (Russian Federation); Bozhko, Aleksandra A., E-mail: bozhko@psu.ru [Faculty of Physics, Perm State University, 15 Bukirev Street, Perm 614990 (Russian Federation); Krauzin, Pavel V., E-mail: krauzin@psu.ru [Faculty of Physics, Perm State University, 15 Bukirev Street, Perm 614990 (Russian Federation); Suslov, Sergey A., E-mail: ssuslov@swin.edu.au [Department of Mathematics H38, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia)

    2017-06-01

    It is shown experimentally that, depending on the relative orientation of the gravity and the thermal gradient and on the pre-history of experiment, the application of a uniform external vertical magnetic field to a spherical cavity filled with magnetic ferrofluid can either enhance or suppress a convective heat transfer. - Highlights: • Conduction heat transfer in magnetic fluid heated from above is stronger than that in a fluid not containing nanoparticles. • The application of a uniform vertical magnetic field enhances heat transfer when magnetic fluid is heated from above. • Heat transfer in a magnetic fluid heated from below is weaker than that in a fluid not containing nanoparticles.

  17. Ferrofluid meniscus in a horizontal or vertical magnetic field

    Rosensweig, R.E.; Elborai, S.; Lee, S.-H.; Zahn, M.

    2005-01-01

    An optical system using reflections of a narrow laser beam to measure the height and shape of a ferrofluid meniscus in response to uniform applied magnetic fields finds that meniscus height on a vertical flat wall decreases in horizontal applied field and increases in vertical applied field. An approximate energy minimization analysis predicts meniscus height in directional agreement with measurements. This study is a first step in calculating the tangential surface force acting in flows where magnetization magnitude and direction lag a changing magnetic field direction, and the meniscus shape is magnetically perturbed

  18. Effects of drying process on the physicochemical properties of nopal cladodes at different maturity stages.

    Contreras-Padilla, Margarita; Gutiérrez-Cortez, Elsa; Valderrama-Bravo, María Del Carmen; Rojas-Molina, Isela; Espinosa-Arbeláez, Diego Germán; Suárez-Vargas, Raúl; Rodríguez-García, Mario Enrique

    2012-03-01

    Chemical proximate analysis was done in order to determine the changes of nutritional characteristics of nopal powders from three different maturity stages 50, 100, and 150 days and obtained by three different drying processes: freeze dried, forced air oven, and tunnel. Results indicate that nopal powder obtained by the process of freeze dried retains higher contents of protein, soluble fiber, and fat than the other two processes. Also, freeze dried process had less effect on color hue variable. No changes were observed in insoluble fiber content, chroma and lightness with the three different drying processes. Furthermore, the soluble fibers decreased with the age of nopal while insoluble fibers and ash content shows an opposite trend. In addition, the luminosity and hue values did not show differences among the maturity stages studied. The high content of dietary fibers of nopal pad powder could to be an interesting source of these important components for human diets and also could be used in food, cosmetics and pharmaceutical industry.

  19. Evaluation of hyperspectral reflectance for estimating dry matter and sugar concentration in processing potatoes

    The measurement of sugar concentration and dry matter in processing potatoes is a time and resource intensive activity, cannot be performed in the field, and does not easily measure within tuber variation. A proposed method to improve the phenotyping of processing potatoes is to employ hyperspectral...

  20. Modeling a production scale milk drying process: parameter estimation, uncertainty and sensitivity analysis

    Ferrari, A.; Gutierrez, S.; Sin, Gürkan

    2016-01-01

    A steady state model for a production scale milk drying process was built to help process understanding and optimization studies. It involves a spray chamber and also internal/external fluid beds. The model was subjected to a comprehensive statistical analysis for quality assurance using...

  1. The determination of optimum condition in water hyacinth drying process by mixed adsorption drying method and modified fly ash as an adsorbent

    Saputra, Asep Handaya; Putri, Rizky Anggreini

    2017-05-01

    Water hyacinth is an aquatic weed that has a very fast growth which makes it becomes a problem to the ecosystem. On the other hand, water hyacinth has a high fiber content (up to 20% by weight) which makes it potential to become raw material for composites and textile industries. As an aquatic plant, water hyacinth has a high initial moisture content that reaches more than 90%. Meanwhile the moisture content of fiber as a raw material for composite and textile industry should not be more than 10% to maintain the good quality of the products. Mixed adsorption drying method is one of the innovative method that can replace conventional drying process. Fluidization method which has been commonly used in agricultural and pharmaceutical products drying, can be enhanced by combining it with the adsorption method as performed in this study. In mixed fluidization-adsorption drying method, fly ash as adsorbent and water hyacinth fiber were put together into the fluidization column where the drying air evaporate the moisture content in water hyacinth fiber. In addition, the adsorbent adsorb the moisture content in the drying air to make the moisture content of the drying air remain low. The drying process is performed in various temperature and composition of water hyacinth and adsorbent in order to obtain the optimum drying condition. In addition, the effect of fly ash pellet and fly ash powder to the drying process was also performed. The result shows that the higher temperature and the more amount of adsorbent results in the faster drying rate. Fly ash pellet shows a better adsorption since it has a smaller pore diameter and wider surface area. The optimum temperature obtained from this study is 60°C and the optimum ratio of water hyacinth and fly ash is 50:50.

  2. Stevia rebaudiana Leaves: Effect of Drying Process Temperature on Bioactive Components, Antioxidant Capacity and Natural Sweeteners.

    Lemus-Mondaca, Roberto; Ah-Hen, Kong; Vega-Gálvez, Antonio; Honores, Carolina; Moraga, Nelson O

    2016-03-01

    Stevia leaves are usually used in dried state and undergo the inevitable effect of drying process that changes the quality characteristics of the final product. The aim of this study was to assess temperature effect on Stevia leaves through analysis of relevant bioactive components, antioxidant capacity and content of natural sweeteners and minerals. The drying process was performed in a convective dryer at constant temperatures ranging from 30 to 80 °C. Vitamin C was determined in the leaves and as expected showed a decrease during drying proportional to temperature. Phenolics and flavonoids were also determined and were found to increase during drying below 50 °C. Antioxidant activity was determined by DPPH and ORAC assays, and the latter showed the highest value at 40 °C, with a better correlation with the phenolics and flavonoids content. The content of eight natural sweeteners found in Stevia leaves was also determined and an increase in the content of seven of the sweeteners, excluding steviol bioside, was found at drying temperature up to 50 °C. At temperatures between 60 and 80 °C the increase in sweeteners content was not significant. Stevia leaves proved to be an excellent source of antioxidants and natural sweeteners.

  3. Modification of Cell Wall Polysaccharides during Drying Process Affects Texture Properties of Apple Chips

    Min Xiao

    2018-01-01

    Full Text Available The influences of hot air drying (AD, medium- and short-wave infrared drying (IR, instant controlled pressure drop drying (DIC, and vacuum freeze drying (FD on cell wall polysaccharide modification were studied, and the relationship between the modifications and texture properties was analyzed. The results showed that the DIC treated apple chips exhibited the highest crispness (92 and excellent honeycomb-like structure among all the dried samples, whereas the FD dried apple chips had low crispness (10, the minimum hardness (17.4 N, and the highest volume ratio (0.76 and rehydration ratio (7.55. Remarkable decreases in the contents of total galacturonic acid and the amounts of water extractable pectin (WEP were found in all the dried apple chips as compared with the fresh materials. The highest retention of WEP fraction (102.7 mg/g AIR was observed in the FD dried apple chips, which may lead to a low structural rigidity and may be partially responsible for the lower hardness of the FD apple chips. In addition, the crispness of the apple chips obtained by DIC treatment, as well as AD and IR at 90°C, was higher than that of the samples obtained from the other drying processes, which might be due to the severe degradation of pectic polysaccharides, considering the results of the amounts of pectic fractions, the molar mass distribution, and concentrations of the WEP fractions. Overall, the data suggested that the modifications of pectic polysaccharides of apple chips, including the amount of the pectic fractions and their structural characteristics and the extent of degradation, significantly affect the texture of apple chips.

  4. Investigation of temperature dependent magnetic hyperthermia in Fe3O4 ferrofluids

    Nemala, Humeshkar Bhaskar

    Magnetic nanoparticles (MNPs) of Fe3O4 and gamma-Fe2O3 have been exploited in the biomedical fields for imaging, targeted drug delivery and magnetic hyperthermia. Magnetic hyperthermia (MHT), the production of heat using ferrofluids, colloidal suspensions of MNPs, in an external AC magnetic field (amplitude, 100-500 Oe and frequency 50 kHz -1MHz), has been explored by many researchers, both in vitro and in vivo, as an alternative viable option to treat cancer. The heat energy generated by Neel and Brownian relaxation processes of the internal magnetic spins could be used to elevate local tissue temperature to about 46 ˚C to arrest cancerous growth. MHT, due to its local nature of heating, when combined with other forms of treatment such as chemotherapy and/or radiation therapy, it could become an effective therapy for cancer treatment. The efficiency of heat production in MHT is quantified by specific absorption rate (SAR), defined as the power output per gram of the MNPs used. In this thesis, ferrofluids consisting of Fe3O4 MNPs of three different sizes (˜ 10 - 13 nm) coated with two different biocompatible surfactants, dextran and polyethylene glycol (PEG), have been investigated. The structural and magnetic characterization of the MNPs were done using XRD, TEM, and DC magnetization measurements. While XRD revealed the crystallite size, TEM provided the information about morphology and physical size distribution of the MNPs. Magnetic measurements of M-vs-H curves for ferrofluids provided information about the saturation magnetization (Ms) and magnetic core size distribution of MNPs. Using MHT measurements, the SAR has been studied as a function of temperature, taking into account the heat loss due to non-adiabatic nature of the experimental set-up. The observed SAR values have been interpreted using the theoretical framework of linear response theory (LRT). We found the SAR values depend on particle size distribution of MNPs, Ms (65-80 emu/g) and the magnetic

  5. Transverse magneto-optical anisotropy in bidisperse ferrofluids with long range particle correlations

    Elfimova, E.A.; Ivanov, A.O. [Ural Federal University, ul. Lenina 51, Yekaterinburg 620000 (Russian Federation); Popescu, L.B. [Institute for Space Sciences, Atomistilor 409, Magurele RO-077125 (Romania); Socoliuc, V., E-mail: vsocoliuc@acad-tim.tm.edu.ro [Romanian Academy-Timisoara Branch, Center for Fundamental and Advanced Technical Research, Lab. Magnetic Fluids, Bv.M. Viteazu 24, Timisoara RO-300223 (Romania)

    2017-06-01

    A comparative study between experiment and the predictions of a theoretical model developed for the description of magnetically induced dichroism in ferrofluids with long range interacting bidisperse spherical nanoparticles is presented. Magnetically induced dichroism in dilution series of two ferrofluids with different surfactant thickness was measured. Both ferrofluids show a concave solid volume fraction dependence of the specific dichroism, whose characteristics are very well qualitatively explained by the theoretical model. The theory fails to satisfactorily explain the magnetic field dependence of the highly concentrated samples specific dichroism, due to inherent approximations in the virial expansion of the pair correlation function.

  6. Application of exopolysaccharides to improve the performance of ceramic bodies in the unidirectional dry pressing process

    Caneira, Inês; Machado-Moreira, Bernardino; Dionísio, Amélia; Godinho, Vasco; Neves, Orquídia; Dias, Diamantino; Saiz-Jimenez, Cesareo; Miller, Ana Z.

    2015-04-01

    Ceramic industry represents an important sector of economic activity in the European countries and involves complex and numerous manufacturing processes. The unidirectional dry pressing process includes milling and stirring of raw materials (mainly clay and talc minerals) in aqueous suspensions, followed by spray drying to remove excess water obtaining spray-dried powders further subjected to dry pressing process (conformation). However, spray-dried ceramic powders exhibit an important variability in their performance when subjected to the dry pressing process, particularly in the adhesion to the mold and mechanical strength, affecting the quality of the final conformed ceramic products. Therefore, several synthetic additives (deflocculants, antifoams, binders, lubricants and plasticizers) are introduced in the ceramic slips to achieve uniform and homogeneous pastes, conditioning their rheological properties. However, an important variability associated with the performance of the conformed products is still reported. Exopolysaccharides or Extracellular Polymeric Substances (EPS) are polymers excreted by living organisms, such as bacteria, fungi and algae, which may confer unique and potentially interesting properties with potential industrial uses, such as viscosity control, gelation, and flocculation. Polysaccharides, such as pullulan, gellan, carrageenan and xanthan have found a wide range of applications in food, pharmaceutical, petroleum, and in other industries. The aim of this study was the assessment of exopolysaccharides as natural additives to optimize the performance of spray-dried ceramic powders during the unidirectional dry pressing process, replacing the synthetic additives used in the ceramic production process. Six exopolysaccharides, namely pullulan, gellan, xanthan gum, κappa- and iota-carrageenan, and guar gum were tested in steatite-based spray-dried ceramic powders at different concentrations. Subsequently, these ceramic powders were

  7. Development of a freeze-drying process of waste-solution, 2

    Kondo, Isao; Kawasaki, Takeshi

    1988-01-01

    The waste solution treatment process in Plutonium Conversion Development Facility (PCDF) consists of Evaporation-Condensation and Neutrazation-Agglometation-Precipitation process, which produces the distillate as recovered acid at first step and separates Pu-U element from condenced solution at second step. This process needs many stages to get high decontamination efficiency and then the Evaporator is in very corrosive state because the nitric acid solution is heated over 100 degrees C to be evaporated. So, in PCDF, it was started the development of Freeze-Drying process to waste solution treatment. This process is suitable for a little quantity of the solution including nitric acid as produced in the Microwave Heating method. Moreover the process has high decontamination efficiency and has good performance of equipment. The result of the cold test of Freeze-Drying process with nitric acid is discribed in this paper. (author)

  8. Review of the literature for dry reprocessing oxide, metal, and carbide fuel: The AIROX, RAHYD, and CARBOX pyrochemical processes

    Hoyt, R.C.; Rhee, B.W. [Rockwell International Corp., Canoga Park, CA (United States). Energy Systems Group

    1979-09-30

    The state of the art of dry processing oxide, carbide, and metal fuel has been determined through an extensive literature review. Dry processing in one of the most proliferation resistant fuel reprocessing technologies available to date, and is one of the few which can be exported to other countries. Feasibility has been established for oxide, carbide, and metal fuel on a laboratory scale, and large-scale experiments on oxide and carbide fuel have shown viability of the dry processing concept. A complete dry processing cycle has been demonstrated by multicycle processing-refabrication-reirradiation experiments on oxide fuel. Additional experimental work is necessary to: (1) demonstrate the complete fuel cycle for carbide and metal fuel, (2) optimize dry processing conditions, and (3) establish fission product behavior. Dry process waste management is easier than for an aqueous processing facility since wastes are primarily solids and gases. Waste treatment can be accomplished by techniques which have been, or are being, developed for aqueous plants.

  9. Biogenic amine profile in unripe Arabica coffee beans processed according to dry and wet methods.

    Dias, Eduardo C; Pereira, Rosemary G F A; Borém, Flávio M; Mendes, Eulália; de Lima, Renato R; Fernandes, José O; Casal, Susana

    2012-04-25

    Immature coffee fruit processing contributes to a high amount of defective beans, which determines a significant amount of low-quality coffee sold in the Brazilian internal market. Unripe bean processing was tested, taking the levels of bioactive amines as criteria for evaluating the extent of fermentation and establishing the differences between processing methods. The beans were processed by the dry method after being mechanically depulped immediately after harvest or after a 12 h resting period in a dry pile or immersed in water. Seven bioactive amines were quantified: putrescine, spermine, spermidine, serotonin, cadaverine, histamine, and tyramine, with global amounts ranging from 71.8 to 80.3 mg/kg. The levels of spermine and spermidine were lower in the unripe depulped coffee than in the natural coffee. The specific conditions of dry and wet processing also influenced cadaverine levels, and histamine was reduced in unripe depulped coffee. A resting period of 12 h does not induce significant alteration on the beans and can be improved if performed in water. These results confirm that peeling immature coffee can decrease fermentation processes while providing more uniform drying, thus reducing the number of defects and potentially increasing beverage quality.

  10. Anisotropy of magnetoviscous effect in structure-forming ferrofluids

    Sreekumari, Aparna; Ilg, Patrick

    2015-07-01

    The magnetoviscous effect, change in viscosity with change in magnetic field strength, and the anisotropy of the magnetoviscous effect, change in viscosity with orientation of magnetic field, have been a focus of interest for four decades. A satisfactory understanding of the microscopic origin of anisotropy of the magnetoviscous effect in magnetic fluids is still a matter of debate and a field of intense research. Here, we present an extensive simulation study to understand the relation between the anisotropy of the magnetoviscous effect and the underlying change in microstructures of ferrofluids. Our results indicate that field-induced chainlike structures respond very differently depending on their orientation relative to the direction of an externally applied shear flow, which leads to a pronounced anisotropy of viscosity. In this work, we focus on three exemplary values of dipolar interaction strengths which correspond to weak, intermediate, and strong interactions between dipolar colloidal particles. We compare our simulation results with an experimental study on cobalt-based ferrofluids as well as with an existing theoretical model called the chain model. A nonmonotonic behavior in the anisotropy of the magnetoviscous effect is observed with increasing dipolar interaction strength and is explained in terms of microstructure formation.

  11. Numerical investigation on splitting of ferrofluid microdroplets in T-junctions using an asymmetric magnetic field with proposed correlation

    Aboutalebi, Mohammad; Bijarchi, Mohamad Ali; Shafii, Mohammad Behshad; Kazemzadeh Hannani, Siamak

    2018-02-01

    The studies surrounding the concept of microdroplets have seen a dramatic increase in recent years. Microdroplets have applications in different fields such as chemical synthesis, biology, separation processes and micro-pumps. This study numerically investigates the effect of different parameters such as Capillary number, Length of droplets, and Magnetic Bond number on the splitting process of ferrofluid microdroplets in symmetric T-junctions using an asymmetric magnetic field. The use of said field that is applied asymmetrically to the T-junction center helps us control the splitting of ferrofluid microdroplets. During the process of numerical simulation, a magnetic field with various strengths from a dipole located at a constant distance from the center of the T-junction was applied. The main advantage of this design is its control over the splitting ratio of daughter droplets and reaching various microdroplet sizes in a T-junction by adjusting the magnetic field strength. The results showed that by increasing the strength of the magnetic field, the possibility of asymmetric splitting of microdroplets increases in a way that for high values of field strength, high splitting ratios can be reached. Also, by using the obtained results at various Magnetic Bond numbers and performing curve fitting, a correlation is derived that can be used to accurately predict the borderline between splitting and non-splitting zones of microdroplets flow in micro T-junctions.

  12. System Model of Heat and Mass Transfer Process for Mobile Solvent Vapor Phase Drying Equipment

    Shiwei Zhang

    2014-01-01

    Full Text Available The solvent vapor phase drying process is one of the most important processes during the production and maintenance for large oil-immersed power transformer. In this paper, the working principle, system composition, and technological process of mobile solvent vapor phase drying (MVPD equipment for transformer are introduced in detail. On the basis of necessary simplification and assumption for MVPD equipment and process, a heat and mass transfer mathematical model including 40 mathematical equations is established, which represents completely thermodynamics laws of phase change and transport process of solvent, water, and air in MVPD technological processes and describes in detail the quantitative relationship among important physical quantities such as temperature, pressure, and flux in key equipment units and process. Taking a practical field drying process of 500 KV/750 MVA power transformer as an example, the simulation calculation of a complete technological process is carried out by programming with MATLAB software and some relation curves of key process parameters changing with time are obtained such as body temperature, tank pressure, and water yield. The change trend of theoretical simulation results is very consistent with the actual production record data which verifies the correctness of mathematical model established.

  13. Mechanistic modelling of fluidized bed drying processes of wet porous granules

    Mortier, Séverine Thérèse F.C.; De Beer, Thomas; Gernaey, Krist

    2011-01-01

    depending on the geometry of the gas inlet, the gas velocity, characteristics of the particles, the dryer design, etc. Computational Fluid Dynamics (CFD) allows to model this behaviour. Moreover, turbulence can be modelled using several approaches: Reynolds-averaged Navier–Stokes Equations (RANS) or Large...... are powerful tools to gain process insight and eventually develop well-controlled processes. The level of detail embedded in such a model depends on the goal of the model. Several models have therefore been proposed in the literature and are reviewed here. The drying behaviour of one single granule, a porous...... particle, can be described using the continuum approach, the pore network modelling method and the shrinkage of the diameter of the wet core approach. As several granules dry at a drying rate dependent on the gas temperature, gas velocity, porosity, etc., the moisture content of a batch of granules...

  14. True density and apparent density during the drying process for vegetables and fruits: a review.

    Rodríguez-Ramírez, J; Méndez-Lagunas, L; López-Ortiz, A; Torres, S Sandoval

    2012-12-01

    This review presents the concepts involved in determining the density of foodstuffs, and summarizes the volumetric determination techniques used to calculate true density and apparent density in foodstuffs exposed to the drying process. The behavior of density with respect to moisture content (X) and drying temperature (T) is presented and explained with a basis in changes in structure, conformation, chemical composition, and second-order phase changes that occur in the processes of mass and heat transport, as reported to date in the literature. A review of the empirical and theoretical equations that represent density is presented, and their application in foodstuffs is discussed. This review also addresses cases with nonideal density behavior, including variations in ρ(s) and ρ(w) as a function of the inside temperature of the material, depending on drying conditions (X, T). A compilation of studies regarding the density of dehydrated foodstuffs is also presented. © 2012 Institute of Food Technologists®

  15. Pharmaceutical spray drying: solid-dose process technology platform for the 21st century.

    Snyder, Herman E

    2012-07-01

    Requirement for precise control of solid-dosage particle properties created with a scalable process technology are continuing to expand in the pharmaceutical industry. Alternate methods of drug delivery, limited active drug substance solubility and the need to improve drug product stability under room-temperature conditions are some of the pharmaceutical applications that can benefit from spray-drying technology. Used widely for decades in other industries with production rates up to several tons per hour, pharmaceutical uses for spray drying are expanding beyond excipient production and solvent removal from crystalline material. Creation of active pharmaceutical-ingredient particles with combinations of unique target properties are now more common. This review of spray-drying technology fundamentals provides a brief perspective on the internal process 'mechanics', which combine with both the liquid and solid properties of a formulation to enable high-throughput, continuous manufacturing of precision powder properties.

  16. Spent nuclear fuel project cold vacuum drying facility process water conditioning system design description

    IRWIN, J.J.

    1998-01-01

    This document provides the System Design Description (SDD) for the Cold Vacuum Drying Facility (CVDF) Process Water Conditioning (PWC) System. The SDD was developed in conjunction with HNF-SD-SNF-SAR-002, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998), the HNF-SD-SNF-DRD-O02, 1998, Cold Vacuum Drying Facility Design Requirements, and the CVDF Design Summary Report. The SDD contains general descriptions of the PWC equipment, the system functions, requirements and interfaces. The SDD provides references for design and fabrication details, operation sequences and maintenance. This SDD has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved

  17. Preliminary comparison of three processes of AlN oxidation: dry, wet and mixed ones

    Korbutowicz R.

    2016-03-01

    Full Text Available Three methods of AlN layers oxidation: dry, wet and mixed (wet with oxygen were compared. Some physical parameters of oxidized thin films of aluminum nitride (AlN layers grown on silicon Si(1 1 1 were investigated by means Energy-Dispersive X-ray Spectroscopy (EDS and Spectroscopic Ellipsometry (SE. Three series of the thermal oxidations processes were carried out at 1012 °C in pure nitrogen as carrying gas and various gas ambients: (a dry oxidation with oxygen, (b wet oxidation with water steam and (c mixed atmosphere with various process times. All the research methods have shown that along with the rising of the oxidation time, AlN layer across the aluminum oxide nitride transforms to aluminum oxide. The mixed oxidation was a faster method than the dry or wet ones.

  18. Measurement techniques in dry-powdered processing of spent nuclear fuels

    Bowers, D. L.; Hong, J.-S.; Kim, H.-D.; Persiani, P. J.; Wolf, S. F.

    1999-01-01

    High-performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICPMS) detection, α-spectrometry (α-S), and γ-spectrometry (γ-S) were used for the determination of nuclide content in five samples excised from a high-burnup fuel rod taken from a pressurized water reactor (PWR). The samples were prepared for analysis by dissolution of dry-powdered samples. The measurement techniques required no separation of the plutonium, uranium, and fission products. The sample preparation and analysis techniques showed promise for in-line analysis of highly-irradiated spent fuels in a dry-powdered process. The analytical results allowed the determination of fuel burnup based on 148 Nd, Pu, and U content. A goal of this effort is to develop the HPLC-ICPMS method for direct fissile material accountancy in the dry-powdered processing of spent nuclear fuel

  19. Encapsulation of lycopene using spray-drying and molecular inclusion processes

    Itaciara Larroza Nunes

    2007-09-01

    Full Text Available This study aimed to obtain encapsulated lycopene in a powder form, using either spray-drying or molecular inclusion with beta -cyclodextrin ( beta -CD followed by freeze-drying. The encapsulation efficiency using spray-drying ranged from 94 to 96%, with an average yield of 51%, with microcapsules showing superficial indentations and lack of cracks and breakages. Lycopene- beta -CD complexes were only formed at a molar ratio of 1:4, and irregular structures of different sizes that eventually formed aggregates, similar to those of beta -CD, were observed after freeze-drying. About 50% of the initial lycopene did not form complexes with beta -CD. Lycopene purity increased from 96.4 to 98.1% after spray-drying, whereas lycopene purity decreased from 97.7 to 91.3% after complex formation and freeze-drying. Both the drying processes yielded pale-pink, dry, free-flowing powders.Técnicas de encapsulamento, como "spray-drying" e formação de complexos por inclusão com ciclodextrinas, vêm sendo avaliadas para viabilizar a adição de carotenóides em sistemas hidrofílicos e aumentar a sua estabilidade durante o processamento e estocagem. Portanto, o objetivo do presente trabalho foi obter licopeno encapsulado na forma de pó, utilizando processos de "spray-drying" ou de inclusão molecular com beta -ciclodextrina (CD seguido de liofilização. A eficiência do encapsulamento utilizando "spray-drying" variou de 94 a 96% e o rendimento médio foi de 51%, com as microcápsulas apresentando indentações superficiais, porém sem falhas ou aberturas na superfície. A formação de complexo licopeno- beta -CD ocorreu apenas quando utilizada razão molar de 1:4, e estruturas irregulares de diferentes tamanhos que eventualmente formaram agregados, similares às da beta -CD, foram observadas após liofilização. O licopeno não complexado neste processo ficou em torno de 50%. A pureza do licopeno (% área do all-trans-licopeno aumentou de 96,4 para 98,1% ap

  20. The spray-drying process is sufficient to inactivate infectious porcine epidemic diarrhea virus in plasma.

    Gerber, Priscilla F; Xiao, Chao-Ting; Chen, Qi; Zhang, Jianqiang; Halbur, Patrick G; Opriessnig, Tanja

    2014-11-07

    Porcine epidemic diarrhea virus (PEDV) is considered an emergent pathogen associated with high economic losses in many pig rearing areas. Recently it has been suggested that PEDV could be transmitted to naïve pig populations through inclusion of spray-dried porcine plasma (SDPP) into the nursery diet which led to a ban of SDPP in several areas in North America and Europe. To determine the effect of spray-drying on PEDV infectivity, 3-week-old pigs were intragastrically inoculated with (1) raw porcine plasma spiked with PEDV (RAW-PEDV-CONTROL), (2) porcine plasma spiked with PEDV and then spray dried (SD-PEDV-CONTROL), (3) raw plasma from PEDV infected pigs (RAW-SICK), (4) spray-dried plasma from PEDV infected pigs (SD-SICK), or (5) spray-dried plasma from PEDV negative pigs (SD-NEG-CONTROL). For the spray-drying process, a tabletop spray-dryer with industry-like settings for inlet and outlet temperatures was used. In the RAW-PEDV-CONTROL group, PEDV RNA was present in feces at day post infection (dpi) 3 and the pigs seroconverted by dpi 14. In contrast, PEDV RNA in feces was not detected in any of the pigs in the other groups including the SD-PEDV-CONTROL group and none of the pigs had seroconverted by termination of the project at dpi 28. This work provides direct evidence that the experimental spray-drying process used in this study was effective in inactivating infectious PEDV in the plasma. Additionally, plasma collected from PEDV infected pigs at peak disease did not contain infectious PEDV. These findings suggest that the risk for PEDV transmission through commercially produced SDPP is minimal. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Novel hybridized drying methods for processing of apple fruit: Energy conservation approach

    Hazervazifeh, Amin; Nikbakht, Ali M.; Moghaddam, Parviz A.

    2016-01-01

    Strategic outlook of apple cultivation and its significant post-processing challenges have been the leading factors for energy and time saving research approaches in apple processing. In this research, apple slices were subjected to hot air flow, microwave radiation and combined microwave-hot air flow drying. Drying time, energy consumption and thermal efficiency at different microwave power levels (500 W, 1000 W, 1500 W and 2000 W), hot air temperatures (40 °C, 50 °C, 60 °C and 70 °C) and inlet air velocities (0.5 ms"−"1, 1 ms"−"1, 1.5 ms"−"1 and 2 ms"−"1) were studied and compared. The minimum time of processing was 17 min when integrated hot air flow and microwave radiation was applied with 2000 W power at the temperature of 70 °C and air velocity of 2 ms"−"1. Furthermore, the minimum value of total energy consumption during entire process of apple slices drying was 2684 kJ which belonged to microwave drying with 2000 W power. - Highlights: • Microwave radiation is implemented to reduce the energy demand for drying. • Simultaneous impact of microwave and hot air on energy and time consumption was analyzed. • Minimum drying time occurs with combined utilization of microwave and hot air. • Thermal efficiency was desirable in low air velocities and high temperatures. • Thermal efficiency of microwave radiation increased by 200% compared to single hot air method.

  2. Application of ferrofluid density separation to particles in the micrometer-size range

    Strebin, R.S. Jr.; Johnson, J.W.; Robertson, D.M.

    1976-02-01

    A device designed and described by AVCO* as a ''Ferrofluid Density Separator''/sup (1)/ develops an apparent fluid density from nominally 2 to 20 g/cm 3 dependent on the magnitude of an imposed magnetic field gradient. The ferrofluid retains other normal properties of a liquid. One of these devices and a concentration series of ferrofluids were obtained in order to determine the practicality of separating groups of micrometer-size particles into density fractions. Such separations would be of enormous value in the study of various particle burdens because particles of interest are almost always diluted with overwhelming amounts of other particles. The results of a study of separations of micrometer-size particles with the ferrofluid density separator are presented

  3. Evaluation of using ferrofluid as an interface material for a field-reversible thermal connector

    Yousif, Ahmed S.

    The electrical functionality of an avionics chassis is limited due to heat dissipation limits. The limits arise due to the fact that components in an avionic computer boxes are packed very compactly, with the components mounted onto plug-in cards, and the harsh environment experienced by the chassis limits how heat can be dissipated from the cards. Convective and radiative heat transfer to the ambient are generally not possible. Therefore it is necessary to have heat transferred from the components conducted to the edge of the plug-in cards. The heat then needs to conduct from the card edge to a cold block that not only holds the card in place, but also removes the generated heat by some heat transfer fluid that is circulated through the cold block. The interface between the plug-in card and the cold block typically has a high thermal resistance since it is necessary for the card to have the capability to be re-workable, meaning that the card can be removed and then returned to the chassis. Reducing the thermal resistance of the interface is the objective of the current study and the topic of this thesis. The current design uses a pressure interface between the card and cold block. The contact pressure is increased through the addition of a wedgelock, which is a field-reversible mechanical connector. To use a wedgelock, the cold block has channels milled on the surface with widths that are larger than the thickness of the plug-in card and the un-expanded wedgelock. The card edge is placed in the channel and placed against one of the channel walls. A wedgelock is then placed between the card and the other channel wall. The wedgelock is then expanded by using either a screw or a lever. As the wedgelock expands it fills in the remaining channel gap and bears against the other face of the plug-in card. The majority of heat generated by the components on the plug-in card is forced to conduct from the card into the wall of the cold block, effectively a single sided, dry

  4. Some biological effects of one water based ferrofluid in cucurbita pepo

    Racuciu, M.; Creanga, D.; Olteanu, Z.; Horga, E. I.

    2005-01-01

    Full text: The biological interest in the ferrofluid effect in living organisms represents an important application field, mainly for biotechnological use, since the small ferrophase size allows the penetration through the biological membranes. Experiments have been designed to reveal the influences of an aqueous ferrofluid on the assimilatory pigments, the peroxide level, nucleic acid level and on the substance accumulation. Water based ferrofluid, stabilized with citric acid was added in various concentrations (10-50-100- 150-200-250 micro L/L) (after vigorous shaking) in the culture medium of Cucurbita pepo plantlets (pumpkin). Spectrophotometric standard assay methods have been applied in order to get experimental data regarding the levels of assimilatory pigments (chlorophyll a, chlorophyll b, carotenes), nucleic acids and peroxydase like enzymes. JASCO V350 spectrophotometer provided with. The stimulatory effect of relatively high ferrofluid concentrations have been observed in the ratio chlorophyll a/b, known as a measure of photosynthesis ratio. Non-significant changes in the nucleic acid level were noticed. Inhibitory effect upon the enzyme biosynthesis was assigned to the ferrofluid addition. The statistic analysis was accomplished by considering five repetitions of every measurement in ferrofluid samples and control ones. Average values of ferrofluid samples and control ones have been compared by means of t-test. Statistic significance was revealed in comparison to the significance threshold of 0.05. (Also one figure included.) References: [1] C. Gro , K.Buescher, E. Romanus, C,A, Helm, W.Weitschies, European cells and Materials, 2002, 3(2), 163. [2] M.M.Zamfirache, G. Capraru, D. Creanga, M. Racuciu, Gh. Calugaru, Ferrofluid experiment for simulating pollution effect on plant growth, The Annals of University Galati, 2004(XXVII), Fasc.II, 37. [3] A.Goodarzi, Y.Sahoo, M.T.Swihart, P.N. Prasad, Mat.Res.Soc.Symp.Proc., 2004,Vol.789, N6.6.1

  5. Laser cutting eliminates nucleic acid cross-contamination in dried-blood-spot processing.

    Murphy, Sean C; Daza, Glenda; Chang, Ming; Coombs, Robert

    2012-12-01

    Dried blood spots (DBS) are useful for molecular assays but are prone to false positives from cross-contamination. In our malaria DBS assay, cross-contamination was encountered despite cleaning techniques suitable for HIV-1. We therefore developed a contact-free laser cutting system that effectively eliminated cross-contamination during DBS processing.

  6. Increase in the free radical scavenging capability of bitter gourd by a heat-drying process.

    Wei, Lu; Shaoyun, Wang; Shutao, Liu; Jianwu, Zhou; Lijing, Ke; Pingfan, Rao

    2013-12-01

    Bitter gourd (Momordica charantia Linn.) is widely regarded as one of the best remedy foods for diabetes. The positive effect of bitter gourd on diabetes has been attributed in part to the remarkable free radical scavenging activity of its boiled water extract from sun-dried fruits. It is well known that a heat process significantly influences the antioxidant activity of fresh fruits. However, the heat drying processes of bitter gourd have not been studied so far. Here, we show that the free radical scavenging capability of bitter gourd extract significantly increases after the heat drying process, while the content of flavonoids and phenols, which are generally regarded as the main antioxidant components in bitter gourd, remain unaffected. Furthermore, the content of free amino acids and the total reducing sugar were found to decrease with increasing browning index, indicating the progression of the Maillard reaction, products of which are known to possess significant antioxidant activity. Therefore, it suggests that Maillard reaction products may be the main contributors to the increase in antioxidant capability. Finally, the bitter gourd extract with the higher antioxidant activity, was shown to manifest a corresponding higher proliferation activity on NIT-1 beta-cells. These results suggest that controllable conditions in the heat-drying processing of fresh bitter gourd fruit is of significance for enhancing the total free radical scavenging capacity, beta-cell proliferation activity and possibly the anti-diabetic activity of this fruit.

  7. Physically based modelling and optimal operation for product drying during post-harvest processing.

    Boxtel, van A.J.B.; Lukasse, L.; Farkas, I.; Rendik, Z.

    1996-01-01

    The development of new procedures for crop production and post-harvest processing requires models. Models based on physical backgrounds are most useful for this purpose because of their extrapolation potential. An optimal procedure is developed for alfalfa drying using a physical model. The model

  8. PROPOSAL FOR THE IMPLEMENTATION OF SPRAY DRYING IN THE ACTIVATION PROCESS OF BENTONITE WITH SULFURIC ACID

    Romero, P.; Otiniano, M.

    2014-01-01

    The present work propose the replacement of the three stages of the activation process of bentonite with sulfuric acid by the only stage spray drying. El presente trabajo propone reemplazar tres etapas del proceso de activación de la bentonita con ácido sulfúrico por una sola etapa, la del secado por atomización.

  9. Quality by design approach in the optimization of the spray-drying process.

    Baldinger, Arnaud; Clerdent, Lucas; Rantanen, Jukka; Yang, Mingshi; Grohganz, Holger

    2012-01-01

    The aim of this study was to illustrate the influence of the processing parameters, inlet temperature, atomization air flow rate and feed flow rate, on critical quality attributes of spray-dried powders using design of experiments (DoE). Spray-dried powders were characterized by laser diffraction, X-ray powder diffraction (XRPD) and near-infrared spectroscopy (NIR). Multivariate analysis of two different experimental designs was performed to elucidate the optimal process conditions. XRPD revealed that the spray-dried powders consisted of crystalline β-mannitol and amorphous trehalose. Non-invasive NIR measurement was successfully used for correlating the critical quality attribute particle size with size determined by laser diffraction. The full factorial design proved to be unsuitable due to the non-linear influence of factors. The composite face-centered design improved the quality of the models and showed both linear and non-linear influence of the parameters on the outcomes. A model explaining the influence of the factors on all quality attributes showed similar results as the models optimized for a single response. This study showed the applicability of DoE for the investigation of spray-dried powders. The knowledge of the interplay between process parameters and quality attributes will enable rational process design to achieve a desired outcome.

  10. Optimization of a pharmaceutical freeze-dried product and its process using an experimental design approach and innovative process analyzers.

    De Beer, T R M; Wiggenhorn, M; Hawe, A; Kasper, J C; Almeida, A; Quinten, T; Friess, W; Winter, G; Vervaet, C; Remon, J P

    2011-02-15

    The aim of the present study was to examine the possibilities/advantages of using recently introduced in-line spectroscopic process analyzers (Raman, NIR and plasma emission spectroscopy), within well-designed experiments, for the optimization of a pharmaceutical formulation and its freeze-drying process. The formulation under investigation was a mannitol (crystalline bulking agent)-sucrose (lyo- and cryoprotector) excipient system. The effects of two formulation variables (mannitol/sucrose ratio and amount of NaCl) and three process variables (freezing rate, annealing temperature and secondary drying temperature) upon several critical process and product responses (onset and duration of ice crystallization, onset and duration of mannitol crystallization, duration of primary drying, residual moisture content and amount of mannitol hemi-hydrate in end product) were examined using a design of experiments (DOE) methodology. A 2-level fractional factorial design (2(5-1)=16 experiments+3 center points=19 experiments) was employed. All experiments were monitored in-line using Raman, NIR and plasma emission spectroscopy, which supply continuous process and product information during freeze-drying. Off-line X-ray powder diffraction analysis and Karl-Fisher titration were performed to determine the morphology and residual moisture content of the end product, respectively. In first instance, the results showed that - besides the previous described findings in De Beer et al., Anal. Chem. 81 (2009) 7639-7649 - Raman and NIR spectroscopy are able to monitor the product behavior throughout the complete annealing step during freeze-drying. The DOE approach allowed predicting the optimum combination of process and formulation parameters leading to the desired responses. Applying a mannitol/sucrose ratio of 4, without adding NaCl and processing the formulation without an annealing step, using a freezing rate of 0.9°C/min and a secondary drying temperature of 40°C resulted in

  11. Magnetowetting and sliding motion of a sessile ferrofluid droplet in the presence of a permanent magnet.

    Nguyen, Nam-Trung; Zhu, Guiping; Chua, Yong-Chin; Phan, Vinh-Nguyen; Tan, Say-Hwa

    2010-08-03

    Motion of a droplet on a planar surface has applications in droplet-based lab on a chip technology. This paper reports the experimental results of the shape, contact angles, and motion of ferrofluid droplets driven by a permanent magnet on a planar homogeneous surface. The water-based ferrofluid in use is a colloidal suspension of single-domain magnetic nanoparticles. The effect of the magnetic field on the apparent contact angle of the ferrofluid droplet was first investigated. The results show that an increasing magnetic flux decreases the apparent contact angle of a sessile ferrofluid droplet. Next, the dynamic contact angle was investigated by observing the shape and the motion of a sessile ferrofluid droplet. The advancing and receding contact angles of the moving ferrofluid were measured at different moving speeds and magnetic field strengths. The measured contact angles were used to estimate the magnitude of the forces involved in the sliding motion. Scaling analysis was carried out to derive the critical velocity, beyond which the droplet is not able to catch up with the moving magnet.

  12. Preparation of a novel ferrofluidic photoresist for two-photon photopolymerization technique

    Tian Ye; Lu Dongxiao; Jiang Haobo; Lin Xiaomei

    2012-01-01

    We present a novel route for the preparation of ferrofluidic photoresist compatible with two-photon photopolymerization (TPP). To get a homogeneous ferrofluidic photoresit, the compatibility of photoresist and magnetic materials has been improved. Monodispersed Fe 3 O 4 nanoparticles synthesized via thermal decomposition of iron precursor were stabilized by 6-(methacryloyloxy) hexanoic acid (a kind of acrylate-based monomer). A ferrofluidic photoresist was prepared by doping the modified Fe 3 O 4 nanoparticles in acrylate-based resin. In this way, the dispersibility of nanoparticles in photoresist was enhanced significantly. As a representative example, a precise magnetic micron-sized spring was created. In the test of the magnetic response, the sensitivity of magnetic microspring was improved remarkably due to the optimization of the ferrofluidic photoresist. When the intensity of external magnetic field reached a value of 1500 Gs, the deformation rate of the microspring would get to 2.25, indicating the compatibility of the ferrofluidic photoresist in microfabrication. - Highlights: ► A novel ferrofluid photoresist was developed for TPP fabrication. ► A micrometer-sized magnetic spring was successfully created. ► Performance of microsprings was highly improved due to the optimization of nanoparticles.

  13. Optimization and application of spray-drying process on oyster cooking soup byproduct

    Huibin CHEN

    Full Text Available Abstract Oyster drying processes have produced a large amount of cooking soup byproducts. In this study, oyster cooking soup byproduct was concentrated and spray-dried after enzymatic hydrolysis to produce seasoning powder. Response surface methodology (RSM was performed on the basis of single-factor studies to optimize the feeding temperature, hot air temperature, atomization pressure, and total solid content of oyster drying. Results revealed the following optimized parameters of this process: feeding temperature of 60 °C, total solid content of 30%, hot air temperature of 197 °C, and atomization pressure of 92 MPa. Under these conditions, the oyster powder yield was 63.7% ± 0.7% and the moisture content was 4.1% ± 0.1%. Our pilot trial also obtained 63.1% yield and 4.0% moisture content. The enzyme hydrolysis of cooking soup byproduct further enhanced the antioxidant activity of the produced oyster seasoning powder to some extent. Spray drying process optimized by RSM can provide a reference for high-valued applications of oyster cooking soup byproducts.

  14. Experimental investigation on influence of porous material properties on drying process by a hot air jet

    Di Marco, P; Filippeschi, S

    2012-01-01

    The drying process of porous media is a subject of scientific interest, and different mathematical approaches can be found in the literature. A previous paper by the same authors showed that the celebrated Martin correlation for hot air jet heat and mass transfer yields different degrees of accuracy (from 15% to 65%, increasing at high values of input power) if tested on different fabrics, the remaining conditions being the same. In this paper the fabric drying has been experimentally investigated more in depth. A dedicated experimental apparatus for hot jet drying was assembled and operated, in which a hot jet impinges perpendicularly onto a wet fabric. A calibrated orifice was adopted to measure the jet flow rate, with an accuracy better than 3%. The drying power was determined by continuously weighing with a precision scale a moistened patch exposed to the drying jet. The effect of the time of the exposure and the initial amount of water has been evaluated for each sample. During the hot jet exposure, the temperature distribution over the wet patch has been observed by an infrared thermo-camera. A mathematical model of water transport inside and outside the fabric was developed, in order to evidence the governing transport resistances. The theoretical predictions have been compared with the experimental results, and showed the necessity to modify correlations and models accounting for fabric properties.

  15. Incineration of dry burnable waste from reprocessing plants with the Juelich incineration process

    Dietrich, H.; Gomoll, H.; Lins, H.

    1987-01-01

    The Juelich incineration process is a two stage controlled air incineration process which has been developed for efficient volume reduction of dry burnable waste of various kinds arising at nuclear facilities. It has also been applied to non nuclear industrial and hospital waste incineration and has recently been selected for the new German Fuel Reprocessing Plant under construction in Wackersdorf, Bavaria, in a modified design

  16. Influence of chemical, physical and texture characteristics in the dry milled clays micro granulation process

    Bernardes, L.B.; Moreno, M.M.T.

    2012-01-01

    We studied the effects of the granulation in ceramic dry process classified as BIIb. For this we used a high intensity granulator to obtain information on the technical and economic viability in the production line and the possible contributions to the improvement of the process. Industrial compositions of clays were used. These materials were processed under different conditions and subsequently processed for obtaining the ceramic bodies pressed. The results indicate that the use of high intensity granulator, with or without modifications to the particle size distribution of mass, can decrease the firing cycle and / or sintering temperature of the ceramic, causing economic gain (author)

  17. Assessment of the dry process fuel sodium-cooled fast reactors

    Roh, Gyu Hong; Choi, Hang Bok

    2004-04-01

    The feasibility of using dry-processed oxide fuel in a Sodium-cooled Fast Reactor (SFR) was analyzed for the equilibrium fuel cycle of two reference cores: Hybrid BN-600 benchmark core with a enlarged lattice pitch and modified BN-600 core. The dry process technology assumed in this study based on the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was {approx}50% and most of the fission products were removed.

  18. Assessment of the dry process fuel sodium-cooled fast reactors

    Roh, Gyu Hong; Choi, Hang Bok

    2004-04-01

    The feasibility of using dry-processed oxide fuel in a Sodium-cooled Fast Reactor (SFR) was analyzed for the equilibrium fuel cycle of two reference cores: Hybrid BN-600 benchmark core with a enlarged lattice pitch and modified BN-600 core. The dry process technology assumed in this study based on the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was ∼50% and most of the fission products were removed

  19. Evaluation of Internal Cracks and Collapse in Poplar Wood (Populus nigra during a Conventional Drying Process with Ultrasonic Inspection

    Saeid ESHAGHI

    2012-05-01

    Full Text Available In this research, internal cracks and collapse of wood, formed during drying process, were measured using ultrasonic inspection. For this purpose, seven poplar (Populus nigra small blocks were dried, according to a time-based schedule. Ultrasonic waves� propagation velocity was measured at both parallel and perpendicular to grain directions, using Sylvatest ultrasound device, during kiln drying process. Results showed that in all dried blocks, waves� propagation velocity in the parallel direction was higher than in the perpendicular direction to grain. Ultrasonic waves� propagation test for non-destructive identification of internal cracks, which occurs in wood during drying process in the parallel direction, was more successful compared to the perpendicular direction. Using ultrasonic waves� propagation test for detection of collapse that occurs in wood during drying process was not useful.

  20. Evaluation of Internal Cracks and Collapse in Poplar Wood (Populus nigra during a Conventional Drying Process with Ultrasonic Inspection

    Saeid ESHAGHI

    2012-05-01

    Full Text Available In this research, internal cracks and collapse of wood, formed during drying process, were measured using ultrasonic inspection. For this purpose, seven poplar (Populus nigra small blocks were dried, according to a time-based schedule. Ultrasonic waves propagation velocity was measured at both parallel and perpendicular to grain directions, using Sylvatest ultrasound device, during kiln drying process. Results showed that in all dried blocks, waves propagation velocity in the parallel direction was higher than in the perpendicular direction to grain. Ultrasonic waves propagation test for non-destructive identification of internal cracks, which occurs in wood during drying process in the parallel direction, was more successful compared to the perpendicular direction. Using ultrasonic waves propagation test for detection of collapse that occurs in wood during drying process was not useful.

  1. Modeling of the process of moisture loss during the storage of dried apricots.

    Miranda, G; Berna, A; Bon, J; Mulet, A

    2011-10-01

    Moisture content is a reference parameter for dried food because the growth of most microorganisms is inhibited below certain water activity levels. In addition, it has a determining influence on the evolution of important parameters, such as color and flavor, and on other properties and deterioration reactions, such as texture, oxidation processes and nutritional value. During the storage of some dried fruits, moisture is produced due to Maillard reactions and exchanged with the surrounding environment through the packaging. The evolution of dried foods during their shelf life depends on the storage conditions. The aim of this study is to analyze the evolution of the moisture content in dried apricots packaged in different types of containers, namely glass and thermosealed polypropylene trays. The samples were stored at constant temperatures: 5, 15, 25 and 35 °C and were analyzed periodically over a period of 12 months. The sorption isotherms of apricots used in this study were also determined. In order to model how the moisture evolved, an empirical kinetic model was tested. This model considers both water transfer from the fruit and also water production as a result of the Maillard processes. The explained variance was higher than 95% in the samples stored in trays, which were thermosealed with film.

  2. Optimization of Agave tequilana Weber var. Azul Juice Spray Drying Process

    Alejandra Chávez-Rodríguez

    2014-01-01

    Full Text Available In this work, the response surface methodology was employed to optimize the microencapsulation of Agave tequilana Weber var. azul juice with whey protein isolated using a spray drying technique. A Box-Behnken design was used to establish optimum spray drying conditions for Agave tequilana juice. The process was optimized to obtain maximum powder yield with the best solubility time, hygroscopicity, bulk density, water activity, and reducing sugars. The independent parameters for the spray drying process were outlet temperature of 70–80°C, atomizer speed of 20000–30000 rpm, and airflow of 0.20–0.23 m3 s−1. The best spray drying condition was at outlet temperature of 80°C, atomizer speed of 20000 rpm, and air flow rate of 0.23 m3 s−1 to obtain maximum powder yield (14.65%bm, minimum solubility time (352.8 s, maximum bulk density (560 kg m−3, minimum hygroscopicity (1.9×10-7 kgwater s−1, and minimum aw (0.39. The Agave tequilana powder may be considered as an interesting source of dietary fiber used as food additive in food and nutraceutical industries.

  3. Sewage sludge drying process integration with a waste-to-energy power plant.

    Bianchini, A; Bonfiglioli, L; Pellegrini, M; Saccani, C

    2015-08-01

    Dewatered sewage sludge from Waste Water Treatment Plants (WWTPs) is encountering increasing problems associated with its disposal. Several solutions have been proposed in the last years regarding energy and materials recovery from sewage sludge. Current technological solutions have relevant limits as dewatered sewage sludge is characterized by a high water content (70-75% by weight), even if mechanically treated. A Refuse Derived Fuel (RDF) with good thermal characteristics in terms of Lower Heating Value (LHV) can be obtained if dewatered sludge is further processed, for example by a thermal drying stage. Sewage sludge thermal drying is not sustainable if the power is fed by primary energy sources, but can be appealing if waste heat, recovered from other processes, is used. A suitable integration can be realized between a WWTP and a waste-to-energy (WTE) power plant through the recovery of WTE waste heat as energy source for sewage sludge drying. In this paper, the properties of sewage sludge from three different WWTPs are studied. On the basis of the results obtained, a facility for the integration of sewage sludge drying within a WTE power plant is developed. Furthermore, energy and mass balances are set up in order to evaluate the benefits brought by the described integration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Magnetoviscoelastic characteristics of superparamagnetic oxides (Fe, Ni) based ferrofluids

    Katiyar, Ajay; Dhar, Purbarun; Nandi, Tandra; Das, Sarit K.

    2017-08-01

    Ferrofluids have been popular among the academic and scientific communities owing to their intelligent physical characteristics under external stimuli and are in fact among the first nanotechnology products to be employed in real world applications. However, studies on the magnetoviscoelastic behavior of concentrated ferrofluids, especially of superparamagnetic oxides of iron and nickel are rare. The present article comprises the formulation of magneto-colloids utilizing the three various metal oxides nanoparticles viz. Iron (II, III) oxide (Fe3O4), Iron (III) oxide (Fe2O3) and Nickel oxide (NiO) in oil. Iron (II, III) oxide based colloids demonstrate high magnetoviscous characteristics over the other oxides based colloids under external magnetic fields. The maximum magnitude of yield stress and viscosity is found to be 3.0 kPa and 2.9 kPa.s, respectively for iron (II, III) oxide based colloids at 2.6 vol% particle concentration and 1.2 T magnetic field. Experimental investigations reveal that the formulated magneto-nanocolloids are stable, even in high magnetic fields and almost reversible when exposed to rising and drop of magnetic fields of the same magnitude. Observations also reveal that the elastic behavior dominates over the viscous behavior with enhanced relaxation and creep characteristics under the magnetic field. The effect of temperature on viscosity and yield stress of magneto-nanocolloids under magnetic fields has also been discussed. Thus, the present findings have potential applications in various fields such as electromagnetic clutch and brakes of automotive, damping, sealing, optics, nanofinishing etc.

  5. Advantages and Challenges of Dried Blood Spot Analysis by Mass Spectrometry Across the Total Testing Process

    Zakaria, Rosita; Allen, Katrina J.; Koplin, Jennifer J.; Roche, Peter

    2016-01-01

    Introduction Through the introduction of advanced analytical techniques and improved throughput, the scope of dried blood spot testing utilising mass spectrometric methods, has broadly expanded. Clinicians and researchers have become very enthusiastic about the potential applications of dried blood spot based mass spectrometric applications. Analysts on the other hand face challenges of sensitivity, reproducibility and overall accuracy of dried blood spot quantification. In this review, we aim to bring together these two facets to discuss the advantages and current challenges of non-newborn screening applications of dried blood spot quantification by mass spectrometry. Methods To address these aims we performed a key word search of the PubMed and MEDLINE online databases in conjunction with individual manual searches to gather information. Keywords for the initial search included; “blood spot” and “mass spectrometry”; while excluding “newborn”; and “neonate”. In addition, databases were restricted to English language and human specific. There was no time period limit applied. Results As a result of these selection criteria, 194 references were identified for review. For presentation, this information is divided into: 1) clinical applications; and 2) analytical considerations across the total testing process; being pre-analytical, analytical and post-analytical considerations. Conclusions DBS analysis using MS applications is now broadly applied, with drug monitoring for both therapeutic and toxicological analysis being the most extensively reported. Several parameters can affect the accuracy of DBS measurement and further bridge experiments are required to develop adjustment rules for comparability between dried blood spot measures and the equivalent serum/plasma values. Likewise, the establishment of independent reference intervals for dried blood spot sample matrix is required. PMID:28149263

  6. Simultaneous application of microwave energy and hot air to whole drying process of apple slices: drying kinetics, modeling, temperature profile and energy aspect

    Horuz, Erhan; Bozkurt, Hüseyin; Karataş, Haluk; Maskan, Medeni

    2018-02-01

    Drying kinetics, modeling, temperature profile and energy indices were investigated in apple slices during drying by a specially designed microwave-hot air domestic hybrid oven at the following conditions: 120, 150 and 180 W microwave powers coupled with 50, 60 and 70 °C air temperatures. Both sources of energy were applied simultaneously during the whole drying processes. The drying process continued until the moisture content of apple slices reached to 20% from 86.3% (wet basis, w.b). Drying times ranged from 330 to 800 min and decreased with increasing microwave power and air temperatures. The constant rate period was only observed at low microwave powers and air temperatures. Two falling rate periods were observed. Temperature of apple slices sharply increased within the first 60 min, then reached equilibrium with drying medium and finally increased at the end of the drying process. In order to describe drying behavior of apple slices nine empirical models were applied. The Modified Logistic Model fitted the best our experimental data ( R 2 = 0.9955-0.9998; χ 2 = 3.46 × 10-5-7.85 × 10-4 and RMSE = 0.0052-0.0221). The effective moisture and thermal diffusivities were calculated by Fick's second law and ranged from 1.42 × 10-9 to 3.31 × 10-9 m2/s and 7.70 × 10-9 to 12.54 × 10-9 m2/s, respectively. The activation energy ( Ea) values were calculated from effective moisture diffusivity ( Deff), thermal diffusivity ( α) and the rate constant of the best model ( k). The Ea values found from these three terms were similar and varied from 13.04 to 33.52 kJ/mol. Energy consumption and specific energy requirement of the hybrid drying of apple slices decreased and energy efficiency of the drying system increased with increasing microwave power and air temperature. Apples can be dried rapidly and effectively by use of the hybrid technique.

  7. Global Sensitivity Analysis as Good Modelling Practices tool for the identification of the most influential process parameters of the primary drying step during freeze-drying.

    Van Bockstal, Pieter-Jan; Mortier, Séverine Thérèse F C; Corver, Jos; Nopens, Ingmar; Gernaey, Krist V; De Beer, Thomas

    2018-02-01

    Pharmaceutical batch freeze-drying is commonly used to improve the stability of biological therapeutics. The primary drying step is regulated by the dynamic settings of the adaptable process variables, shelf temperature T s and chamber pressure P c . Mechanistic modelling of the primary drying step leads to the optimal dynamic combination of these adaptable process variables in function of time. According to Good Modelling Practices, a Global Sensitivity Analysis (GSA) is essential for appropriate model building. In this study, both a regression-based and variance-based GSA were conducted on a validated mechanistic primary drying model to estimate the impact of several model input parameters on two output variables, the product temperature at the sublimation front T i and the sublimation rate ṁ sub . T s was identified as most influential parameter on both T i and ṁ sub , followed by P c and the dried product mass transfer resistance α Rp for T i and ṁ sub , respectively. The GSA findings were experimentally validated for ṁ sub via a Design of Experiments (DoE) approach. The results indicated that GSA is a very useful tool for the evaluation of the impact of different process variables on the model outcome, leading to essential process knowledge, without the need for time-consuming experiments (e.g., DoE). Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Assessment of the Dry Processed Oxide Fuel in Liquid Metal Fast Reactors

    Roh, Gyu Hong; Choi, Hang Bok

    2005-09-15

    The neutronic feasibility of the dry process oxide fuel was assessed for the sodium-cooled and lead-cooled fast reactors (SFR and LFR, respectively), which were recommended as Generation-IV (Gen-IV) reactor systems by the Gen-IV international forum. The reactor analysis was performed for the equilibrium fuel cycle of two core configurations: Hybrid BN-600 benchmark core with an enlarged lattice pitch and a modified BN-600 core. The dry process technology assumed in this study is the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic (TRU) enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a fissile self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was {approx}50% and most of the fission products were removed. If the design criteria used in this study is proved to be acceptable through a detailed physics design and thermal hydraulic analysis in the future, it is practically possible to construct an equilibrium fuel cycle of the SFR and LFR systems based on the oxide fuel by utilizing the dry process technology.

  9. Assessment of the Dry Processed Oxide Fuel in Liquid Metal Fast Reactors

    Roh, Gyu Hong; Choi, Hang Bok

    2005-09-01

    The neutronic feasibility of the dry process oxide fuel was assessed for the sodium-cooled and lead-cooled fast reactors (SFR and LFR, respectively), which were recommended as Generation-IV (Gen-IV) reactor systems by the Gen-IV international forum. The reactor analysis was performed for the equilibrium fuel cycle of two core configurations: Hybrid BN-600 benchmark core with an enlarged lattice pitch and a modified BN-600 core. The dry process technology assumed in this study is the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic (TRU) enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a fissile self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was ∼50% and most of the fission products were removed. If the design criteria used in this study is proved to be acceptable through a detailed physics design and thermal hydraulic analysis in the future, it is practically possible to construct an equilibrium fuel cycle of the SFR and LFR systems based on the oxide fuel by utilizing the dry process technology

  10. Breakage and drying behaviour of granules in a continuous fluid bed dryer: Influence of process parameters and wet granule transfer.

    De Leersnyder, F; Vanhoorne, V; Bekaert, H; Vercruysse, J; Ghijs, M; Bostijn, N; Verstraeten, M; Cappuyns, P; Van Assche, I; Vander Heyden, Y; Ziemons, E; Remon, J P; Nopens, I; Vervaet, C; De Beer, T

    2018-03-30

    Although twin screw granulation has already been widely studied in recent years, only few studies addressed the subsequent continuous drying which is required after wet granulation and still suffers from a lack of detailed understanding. The latter is important for optimisation and control and, hence, a cost-effective practical implementation. Therefore, the aim of the current study is to increase understanding of the drying kinetics and the breakage and attrition phenomena during fluid bed drying after continuous twin screw granulation. Experiments were performed on a continuous manufacturing line consisting of a twin-screw granulator, a six-segmented fluid bed dryer, a mill, a lubricant blender and a tablet press. Granulation parameters were fixed in order to only examine the effect of drying parameters (filling time, drying time, air flow, drying air temperature) on the size distribution and moisture content of granules (both of the entire granulate and of size fractions). The wet granules were transferred either gravimetrically or pneumatically from the granulator exit to the fluid bed dryer. After a certain drying time, the moisture content reached an equilibrium. This drying time was found to depend on the applied airflow, drying air temperature and filling time. The moisture content of the granules decreased with an increasing drying time, airflow and drying temperature. Although smaller granules dried faster, the multimodal particle size distribution of the granules did not compromise uniform drying of the granules when the target moisture content was achieved. Extensive breakage of granules was observed during drying. Especially wet granules were prone to breakage and attrition during pneumatic transport, either in the wet transfer line or in the dry transfer line. Breakage and attrition of granules during transport and drying should be anticipated early on during process and formulation development by performing integrated experiments on the granulator

  11. Economical analysis of the spray drying process by pre-dehumidification of the inlet air

    Madeira, A.N.; Camargo, J.R. [University of Taubate (UNITAU), SP (Brazil). Mechanical Engineering Dept.

    2009-07-01

    Spray drying is a dehumidification process by atomization in a closed chamber that aims to remove moisture of a product by heat and mass transfer from the product's contained water to the air that, in this process is previously heated. This paper presents a case study for an industry that produces food ingredients. The current process applied in the product to heat the air can uses one of these two systems: a direct heating process that burns liquid petroleum gas in contact with the inlet air or indirect heating that uses a heat exchanger which heat the air. This heating system consumes 90% of the total process energy. However, this inlet air can reach the dehumidifier with high moisture from the atmosphere condition requesting, in this case, more energy consumption according to the year's seasons. This paper promotes a utilization study of the current process through the installation of a pre-dehumidification device of the inlet air and shows a study to three different dehumidification systems that means by refrigeration, adsorption and actual comparing their performance in an energetic and economical point of view. The goals of this study are to analyze the capacity of moisture removing of each removing device, the influence of moisture variation of the inlet air in the process as well as the economic impact of each device in the global system. It concludes that the utilization of dehumidification devices can eliminate the heating system reducing this way the energy consumption. Moreover it promotes the increasing of moisture gradient between the inlet air and the product optimizing the drying process and increasing the global energy efficiency in the global system. Choosing the most appropriate system for the pre-dehumidification device depends on the desired initial and final moisture content of the product, but applying pre-dehumidifiers at the inlet air promotes an energetic optimization in the spray drying process. (author)

  12. Combined osmotic dehydration and drying process of pirarucu (Arapaima gigas) fillets.

    Martins, Mayara Galvão; da Silva Pena, Rosinelson

    2017-09-01

    The osmotic dehydration (OD) and complementary drying of pirarucu ( Arapaima gigas ) fillets were studied. Pieces of the dorsal portion of pirarucu (60 mm × 20 mm × 10 mm) underwent OD in a binary solution (NaCl-water) with the application of vacuum pulse following a central rotatable composite design. The effect of the following process variables was assessed: temperature (20-40 °C), osmotic solution concentration (15-25% NaCl), and vacuum pulse pressure (7-101 kPa) on water loss (WL), solid gain (SG), and water activity (a w ). OD kinetics was obtained and the Peleg model was fitted to WL and SG data. The osmotically dehydrated pirarucu was dried (40-70 °C) in a fixed-bed dryer and mathematical models were fitted to the drying data. The optimal operational condition for the OD process was 35 °C, solution with 25% NaCl, and atmospheric pressure, which yielded WL of 14.87 ± 1.46%, SG of 8.56 ± 0.45%, and a w of 0.87 ± 0.02. The Peleg model efficiently predicted the WL and SG kinetics. The increase in the water loss in drying was more evident at low temperatures (40-50 °C) with effective diffusivity ranging from 10.85 × 10 -9 to 12.30 × 10 -9 m 2 /s. The Midilli and Page models efficiently predicted the drying kinetics.

  13. ENVIRONMENTAL AFTERMATH FROM THE DRYING PROCESSES OF AL-HUWAIZA MARSHLAND, IRAQ

    Khafaja Ahmed Mays SADKHAN

    2017-01-01

    Al-Huwaiza marsh shows environmental and economic significance, but it has been exposed to the drying processes and then to the drowning processes. It has witnessed great decrease in the water resources specified for the country and the decrease in the water portion feeding it. A fact which shows negative effects on its area, for the change of the environmental variables, has affected the process of nurturing the marsh - only 33.4% of the area of the marsh has been drowned during the 1990s...

  14. Temperature Control of Heating Zone for Drying Process: Effect of Air Velocity Change

    Wutthithanyawat Chananchai

    2016-01-01

    Full Text Available This paper proposes a temperature control technique to adjust air temperature in a heating zone for drying process. The controller design is achieved by using an internal model control (IMC approach. When the IMC controller parameters were designed by calculating from an actual process transfer function estimated through an open-loop step response with input step change from 50% to 60% at a reference condition at air velocity of 1.20 m/s, the performance of temperature controller was experimentally tested by varying an air velocity between 1.32 m/s and 1.57 m/s, respectively. The experimental results showed that IMC controller had a high competency for controlling the drying temperature.

  15. Effect of Intermittent Drying Conditions on Fissuring Percentage and Process Duration of Long and Medium Rough Rice Varieties

    A. Ghasemi

    2016-02-01

    Full Text Available One of the factors which affect the quality of rice during milling is internal fissures created during and after drying operation. In many industrial countries intermittent drying method is hired to reduce the moisture content of rough rice in order to reduce the drying time and maintain the quality of the final product. A high percentage of rice breakage during milling process, at least in Iran, necessitates performing the intermittent drying process and optimize it for Iranian varieties. In this study, the effect of this method (drying-tempering and continuous drying method (no tempering on fissuring percentage of Hashemi (long grain and Koohsar (medium grain varieties was investigated. The experiments were carried out at constant drying and tempering temperature of 60 °C, drying durations of 20, 40 and 60 min, and tempering durations of 0 (continuous drying, 40, 80, 120, 160, 200, 240 min. The results revealed that the tempering process significantly reduced the drying time and fissured kernels percentage. Moreover, for both varieties it was observed that the rice fissuring decreased significantly by continuing the tempering process until certain durations. Overall, for optimization of intermittent drying process in terms of the considered qualitative parameters, i.e. reducing energy consumption and losses, conducting 160 and 200 min tempering process after 40 min drying was found appropriate for Hashemi and Koohsar varieties, respectively. In addition, according to the higher fissuring for Koohsar (medium grain compared to Hashemi (long grain, it can be concluded that physical properties such as kernel slenderness ratio is effective on its fissuring.

  16. Parametrication of numerical simulation of drying process in atypicall condenzation lumber kiln

    Jiří Zejda

    2004-01-01

    Full Text Available This work deal with modelling of the process of drying, air flow, temperature and moisture distribution in a condensation lumber kiln. This model was made and solved in the computing system ANSYS with the use of the finite element method. There are comparationes of the 2D and 3D models, shape of wood stacks and variability of their parameters (height, width, length, cross section in the work. The flow velocity and orientation, pressure and temperature field were observed.

  17. Continuous Process for the Etching, Rinsing and Drying of MEMS Using Supercritical Carbon Dioxide

    Min, Seon Ki; Han, Gap Su; You, Seong-sik [Korea University of Technology and Education, Cheonan (Korea, Republic of)

    2015-10-15

    The previous etching, rinsing and drying processes of wafers for MEMS (microelectromechanical system) using SC-CO{sub 2} (supercritical-CO{sub 2}) consists of two steps. Firstly, MEMS-wafers are etched by organic solvent in a separate etching equipment from the high pressure dryer and then moved to the high pressure dryer to rinse and dry them using SC-CO{sub 2}. We found that the previous two step process could be applied to etch and dry wafers for MEMS but could not confirm the reproducibility through several experiments. We thought the cause of that was the stiction of structures occurring due to vaporization of the etching solvent during moving MEMS wafer to high pressure dryer after etching it outside. In order to improve the structure stiction problem, we designed a continuous process for etching, rinsing and drying MEMS-wafers using SC-CO{sub 2} without moving them. And we also wanted to know relations of states of carbon dioxide (gas, liquid, supercritical fluid) to the structure stiction problem. In the case of using gas carbon dioxide (3 MPa, 25 .deg. C) as an etching solvent, we could obtain well-treated MEMS-wafers without stiction and confirm the reproducibility of experimental results. The quantity of rinsing solvent used could be also reduced compared with the previous technology. In the case of using liquid carbon dioxide (3 MPa, 5 .deg. C), we could not obtain well-treated MEMS-wafers without stiction due to the phase separation of between liquid carbon dioxide and etching co-solvent(acetone). In the case of using SC-CO{sub 2} (7.5 Mpa, 40 .deg. C), we had as good results as those of the case using gas-CO{sub 2}. Besides the processing time was shortened compared with that of the case of using gas-CO{sub 2}.

  18. Method of drying passivated micromachines by dewetting from a liquid-based process

    Houston, Michael R.; Howe, Roger T.; Maboudian, Roya; Srinivasan, Uthara

    2000-01-01

    A method of fabricating a micromachine includes the step of constructing a low surface energy film on the micromachine. The micromachine is then rinsed with a rinse liquid that has a high surface energy, relative to the low surface energy film, to produce a contact angle of greater than 90.degree. between the low surface energy film and the rinse liquid. This relatively large contact angle causes any rinse liquid on the micromachine to be displaced from the micromachine when the micromachine is removed from the rinse liquid. In other words, the micromachine is dried by dewetting from a liquid-based process. Thus, a separate evaporative drying step is not required, as the micromachine is removed from the liquid-based process in a dry state. The relatively large contact angle also operates to prevent attractive capillary forces between micromachine components, thereby preventing contact and adhesion between adjacent microstructure surfaces. The low surface energy film may be constructed with a fluorinated self-assembled monolayer film. The processing of the invention avoids the use of environmentally harmful, health-hazardous chemicals.

  19. Nano and microparticle engineering of water insoluble drugs using a novel spray-drying process.

    Schafroth, Nina; Arpagaus, Cordin; Jadhav, Umesh Y; Makne, Sushil; Douroumis, Dennis

    2012-02-01

    In the current study nano and microparticle engineering of water insoluble drugs was conducted using a novel piezoelectric spray-drying approach. Cyclosporin A (CyA) and dexamethasone (DEX) were encapsulated in biodegradable poly(D,L-lactide-co-glycolide) (PLGA) grades of different molecular weights. Spray-drying studies carried out with the Nano Spray Dryer B-90 employed with piezoelectric driven actuator. The processing parameters including inlet temperature, spray mesh diameter, sample flow rate, spray rate, applied pressure and sample concentration were examined in order to optimize the particle size and the obtained yield. The process parameters and the solute concentration showed a profound effect on the particle engineering and the obtained product yield. The produced powder presented consistent and reproducible spherical particles with narrow particle size distribution. Cyclosporin was found to be molecularly dispersed while dexamethasone was in crystalline state within the PLGA nanoparticles. Further evaluation revealed excellent drug loading, encapsulation efficiency and production yield. In vitro studies demonstrated sustained release patterns for the active substances. This novel spray-drying process proved to be efficient for nano and microparticle engineering of water insoluble active substances. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Material accountancy measurement techniques in dry-powdered processing of nuclear spent fuels

    Wolf, S. F.

    1999-01-01

    The paper addresses the development of inductively coupled plasma-mass spectrometry (ICPMS), thermal ionization-mass spectrometry (TIMS), alpha-spectrometry, and gamma spectrometry techniques for in-line analysis of highly irradiated (18 to 64 GWD/T) PWR spent fuels in a dry-powdered processing cycle. The dry-powdered technique for direct elemental and isotopic accountancy assay measurements was implemented without the need for separation of the plutonium, uranium and fission product elements in the bulk powdered process. The analyses allow the determination of fuel burn-up based on the isotopic composition of neodymium and/or cesium. An objective of the program is to develop the ICPMS method for direct fissile nuclear materials accountancy in the dry-powdered processing of spent fuel. The ICPMS measurement system may be applied to the KAERI DUPIC (direct use of spent PWR fuel in CANDU reactors) experiment, and in a near-real-time mode for international safeguards verification and non-proliferation policy concerns

  1. Application of residual polysaccharide-degrading enzymes in dried shiitake mushrooms as an enzyme preparation in food processing.

    Tatsumi, E; Konishi, Y; Tsujiyama, S

    2016-11-01

    To examine the activities of residual enzymes in dried shiitake mushrooms, which are a traditional foodstuff in Japanese cuisine, for possible applications in food processing. Polysaccharide-degrading enzymes remained intact in dried shiitake mushrooms and the activities of amylase, β-glucosidase and pectinase were high. A potato digestion was tested using dried shiitake powder. The enzymes reacted with potato tuber specimens to solubilize sugars even under a heterogeneous solid-state condition and that their reaction modes were different at 38 and 50 °C. Dried shiitake mushrooms have a potential use in food processing as an enzyme preparation.

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

    Kanojia, Gaurav; Willems, Geert-Jan; Frijlink, Henderik W; Kersten, Gideon F A; Soema, Peter C; Amorij, Jean-Pierre

    2016-09-25

    Spray dried vaccine formulations might be an alternative to traditional lyophilized vaccines. Compared to lyophilization, spray drying is a fast and cheap process extensively used for drying biologicals. The current study provides an approach that utilizes Design of Experiments for spray drying process to stabilize whole inactivated influenza virus (WIV) vaccine. The approach included systematically screening and optimizing the spray drying process variables, determining the desired process parameters and predicting product quality parameters. The process parameters inlet air temperature, nozzle gas flow rate and feed flow rate and their effect on WIV vaccine powder characteristics such as particle size, residual moisture content (RMC) and powder yield were investigated. Vaccine powders with a broad range of physical characteristics (RMC 1.2-4.9%, particle size 2.4-8.5μm and powder yield 42-82%) were obtained. WIV showed no significant loss in antigenicity as revealed by hemagglutination test. Furthermore, descriptive models generated by DoE software could be used to determine and select (set) spray drying process parameter. This was used to generate a dried WIV powder with predefined (predicted) characteristics. Moreover, the spray dried vaccine powders retained their antigenic stability even after storage for 3 months at 60°C. The approach used here enabled the generation of a thermostable, antigenic WIV vaccine powder with desired physical characteristics that could be potentially used for pulmonary administration. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Process development for spray drying of sticky pharmaceuticals; case study of bioadhesive nicotine microparticles for compressed medicated chewing gum

    Sander, Camilla; Nielsen, Henrik Stillhof; Søgaard, Susanne Roslev

    2013-01-01

    Spray drying of pharmaceutical compounds with sticky properties is a challenging task and may require substantial time and resources. By including small-scale studies of single droplet drying kinetics a relatively high number of experiments with less material is allowed. This means one can constr...... chewing gum. By illustration of initial studies on single droplet drying kinetics, subsequent characterization of microparticles, and final characterization of compressed chewing gum this paper summarizes the entire development process....

  4. The choice of rational parameters of beet pulp drying process in a pulsed low-pressure vibro-boiling layer

    A. V. Drannikov

    2017-01-01

    Full Text Available Beet pulp is the main sugar industry by-product obtained with traditional production technology. It has high nutritional qualities, but in its raw form it turns sour quickly so it must be preserved. One of the most common methods is drying. Drying of the beet pulp with superheated vapor of reduced pressure in the pulsating vibro-boiling layer allows to improve the quality of the finished product by lowering of the drying agent temperature, thereby retaining a significant amount of nutrients in the initial product. To study the kinetic and hydrodynamic dependencies of the drying process, an experimental apparatus was developed that makes it possible to obtain the most accurate and reproducible results. In the course of the work, a lot of experiments were carried out. Drying curves, drying rate curves and heating curves were made based on these experiments results. According to the nature of the changes the corresponding conclusions were drawn. To study the interaction of various factors affecting the beet pulp drying process, the mathematical methods of experiment planning are applied. A mathematical description of this process can be obtained empirically. At the same time, its mathematical model has the form of a regression equation, determined by statistical methods on the basis of experiments. As a result of statistical processing of experimental data, regression equations were obtained that adequately describe the beet pulp drying process in a pulsed low-pressure vibro-boiling layer in the experimental apparatus. With reference to this drying apparatus, such technological modes of its operation were determined that ensure a minimum specific energy consumption of the drying process per kilogram of evaporated moisture and the maximum drying chamber moisture stress.

  5. Automatic humidification system to support the assessment of food drying processes

    Ortiz Hernández, B. D.; Carreño Olejua, A. R.; Castellanos Olarte, J. M.

    2016-07-01

    This work shows the main features of an automatic humidification system to provide drying air that match environmental conditions of different climate zones. This conditioned air is then used to assess the drying process of different agro-industrial products at the Automation and Control for Agro-industrial Processes Laboratory of the Pontifical Bolivarian University of Bucaramanga, Colombia. The automatic system allows creating and improving control strategies to supply drying air under specified conditions of temperature and humidity. The development of automatic routines to control and acquire real time data was made possible by the use of robust control systems and suitable instrumentation. The signals are read and directed to a controller memory where they are scaled and transferred to a memory unit. Using the IP address is possible to access data to perform supervision tasks. One important characteristic of this automatic system is the Dynamic Data Exchange Server (DDE) to allow direct communication between the control unit and the computer used to build experimental curves.

  6. Sabah snake grass extract pre-processing: Preliminary studies in drying and fermentation

    Solibun, A.; Sivakumar, K.

    2016-06-01

    Clinacanthus nutans (Burm. F.) Lindau which also known as ‘Sabah Snake Grass’ among Malaysians have been studied in terms of its medicinal and chemical properties in Asian countries which is used to treat various diseases from cancer to viral-related diseases such as varicella-zoster virus lesions. Traditionally, this plant has been used by the locals to treat insect and snake bites, skin rashes, diabetes and dysentery. In Malaysia, the fresh leaves of this plant are usually boiled with water and consumed as herbal tea. The objectives of this study are to determine the key process parameters for Sabah Snake Grass fermentation which affect the chemical and biological constituent concentrations within the tea, extraction kinetics of fermented and unfermented tea and the optimal process parameters for the fermentation of this tea. Experimental methods such as drying, fermenting and extraction of C.nutans leaves were conducted before subjecting them to analysis of antioxidant capacity. Conventional oven- dried (40, 45 and 50°C) and fermented (6, 12 and 18 hours) whole C.nutans leaves were subjected to tea infusion extraction (water temperature was 80°C, duration was 90 minutes) and the sample liquid was extracted for every 5th, 10th, 15th, 25th, 40th, 60th and 90th minute. Analysis for antioxidant capacity and total phenolic content (TPC) were conducted by using 2, 2-diphenyl-1-pycryl-hydrazyl (DPPH) and Folin-Ciocaltheu reagent, respectively. The 40°C dried leaves sample produced the highest phenolic content at 0.1344 absorbance value in 15 minutes of extraction while 50°C dried leaves sample produced 0.1298 absorbance value in 10 minutes of extraction. The highest antioxidant content was produced by 50°C dried leaves sample with absorbance value of 1.6299 in 5 minutes of extraction. For 40°C dried leaves sample, the highest antioxidant content could be observed in 25 minutes of extraction with the absorbance value of 1.1456. The largest diameter of disc

  7. Advanced applications of tunable ferrofluids in energy systems and energy harvesters: A critical review

    Khairul, M.A.; Doroodchi, Elham; Azizian, Reza; Moghtaderi, Behdad

    2017-01-01

    Highlights: • Current developments in ferrofluids are reviewed. • The effects of unique features of ferrofluids on thermal properties are studied. • Applications of tunable magnetic nanofluids in energy harvesters are discussed. • Future research on ferrofluid based electromagnetic energy harvesters are suggested. - Abstract: Ferrofluids or Magnetic nanofluids (MNFs) are the suspensions of magnetic nanoparticles and non-magnetic base fluid. The heat transfer performance of a magnetic nano-suspension is influenced by the strength and orientation of an applied magnetic field. The main attraction of these types of nanofluids is that they not only enhance the fluids’ thermophysical properties but also possess both magnetic characteristics like the other magnetic materials and flow ability similar to any other fluids. Such an exclusive feature enables to control heat transfer, fluid flow and movement of the nanoparticles by using the external magnetic fields. This review paper summarises the recent investigations of magnetic nanofluids with the aim of identifying the effects of major parameters on the performance of heat transfer. In addition, this study also acknowledged the novel application of ferrofluids in the electromagnetic energy harvesters, and its challenges as well as the potentiality in the future research.

  8. Studying effect of carrier fluid viscosity in magnetite based ferrofluids using optical tweezers

    Savitha, S.; Iyengar, Shruthi S.; Ananthamurthy, Sharath; Bhattacharya, Sarbari

    2018-02-01

    Ferrofluids with varying viscosities of carrier fluids have been prepared with magnetite (Fe3O4) nanoparticles. The nanoparticles were synthesized by chemical co-precipitation and characterized using X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). They were found to be nearly spherical in shape with an almost uniform size of 13nm. The superparamagnetic nature of the water based ferrofluids at room temperature was established by SQUID magnetometry. Dynamic light scattering (DLS) was carried out to establish the size of the nanoparticle clusters in the ferrofluids synthesized. The results indicate an increase in cluster size with increase in carrier fluid viscosity. This is supported by results from Raman Spectroscopy. A further attempt to characterise these ferrofluids was made by studying the behaviour of well characterised non-magnetic micron sized probes that are optically trapped while suspended in the ferrofluid. An increase in carrier fluid viscosity results in a decrease in corner frequency when only the carrier fluid is used as the suspending medium. When the magnetic component is also present the corner frequency is higher than with just the carrier fluid. This relative increase happens at all laser powers at the trapping plane. This trend is also found to be independent of the size and material of the probe particle. Comparisons of various parameters that influence optical trapping lead us to believe that the enhancement could be due to a directed motion of the magnetic clusters in the presence of an optical trap.

  9. Nanocrystallite characterization of milled simulated dry process fuel powders by neutron diffraction

    Ryu, Ho Jin; Kang, Kwon Ho; Moon, Je Sun; Song, Kee Chan; Choi, Yong Nam

    2003-01-01

    The nano-scale crystallite sizes of simulated spent fuel powders were measured by the neutron diffraction line broadening method in order to analyze the sintering behavior of the dry process fuel. The mixed U0 2 and fission product oxide powders were dry-milled in an attritor for 30, 60, and 120 min. The diffraction patterns of the powders were obtained by using the high resolution powder diffractometer in the HANARO research reactor. Diffraction line broadening due to crystallite size was measured using various techniques such as the Stokes' deconvolution, profile fitting methods using Cauchy function, Gaussian function, and Voigt function, and the Warren-Averbach method. The r.m.s. strain, stacking fault, twin and dislocation density were measured using the information from the diffraction pattern. The realistic crystallite size can be obtained after separation of the contribution from the non-uniform strain, stacking fault and twin

  10. Dielectric-spectroscopy approach to ferrofluid nanoparticle clustering induced by an external electric field.

    Rajnak, Michal; Kurimsky, Juraj; Dolnik, Bystrik; Kopcansky, Peter; Tomasovicova, Natalia; Taculescu-Moaca, Elena Alina; Timko, Milan

    2014-09-01

    An experimental study of magnetic colloidal particles cluster formation induced by an external electric field in a ferrofluid based on transformer oil is presented. Using frequency domain isothermal dielectric spectroscopy, we study the influence of a test cell electrode separation distance on a low-frequency relaxation process. We consider the relaxation process to be associated with an electric double layer polarization taking place on the particle surface. It has been found that the relaxation maximum considerably shifts towards lower frequencies when conducting the measurements in the test cells with greater electrode separation distances. As the electric field intensity was always kept at a constant value, we propose that the particle cluster formation induced by the external ac electric field accounts for that phenomenon. The increase in the relaxation time is in accordance with the Schwarz theory of electric double layer polarization. In addition, we analyze the influence of a static electric field generated by dc bias voltage on a similar shift in the relaxation maximum position. The variation of the dc electric field for the hysteresis measurements purpose provides understanding of the development of the particle clusters and their decay. Following our results, we emphasize the utility of dielectric spectroscopy as a simple, complementary method for detection and study of clusters of colloidal particles induced by external electric field.

  11. Ferrofluid synthesis using oleic acid coated Fe3O4 nanoparticles dispersed in mineral oil for heat transfer applications

    Imran, Mohd; Rahman Ansari, Akhalakur; Hussain Shaik, Aabid; Abdulaziz; Hussain, Shahir; Khan, Afzal; Rehaan Chandan, Mohammed

    2018-03-01

    Ferrofluids are stable dispersion of iron oxide nanoparticles in a carrier fluid which find potential applications in heat transfer. Fe3O4 nanoparticles of mean size in the range of 5–10 nm were synthesized using conventional co-precipitation method. This work deals with the synthesis of ferrofluids using mineral oil as a carrier fluid and oleic acid coated Fe3O4 nanoparticles as dispersed phase. Morphology (shape and size) and crystallinity of the synthesized nanoparticle is captured using TEM and XRD. Oleic acid coating on nanoparticle is probed using FTIR for confirming the stability of ferrofluid. Thermal properties of mineral oil based ferrofluid with varying concentration of nanoparticles are evaluated in terms of thermal conductivity. It was found that the thermal conductivity of ferrofluid increases upto 2.5% (w/v) nanoparticle loading, where a maximum enhancement of ∼51% in thermal conductivity was recorded as compared to the base fluid.

  12. Experimental verification of the energetic model of the dry mechanical reclamation process

    R. Dańko

    2008-04-01

    Full Text Available The experimental results of the dry mechanical reclamation process, which constituted the bases for the verification of the energetic model of this process, developed by the author on the grounds of the Rittinger’s deterministic hypothesis of the crushing process, are presented in the paper. Used foundry sands with bentonite, with water-glass from the floster technology and used sands with furan FL 105 resin were used in the reclamation tests. In the mechanical and mechanical-cryogenic reclamation a wide range of time variations and reclamation conditions influencing intensity of the reclamation process – covering all possible parameters used in industrial devices - were applied. The developed theoretical model constitutes a new tool allowing selecting optimal times for the reclamation treatment of the given spent foundry sand at the assumed process intensity realized in rotor reclaimers - with leaves or rods as grinding elements mounted horizontally on the rotor axis.

  13. Yeast diversity and dynamics in the production processes of Norwegian dry-cured meat products.

    Asefa, Dereje T; Møretrø, Trond; Gjerde, Ragnhild O; Langsrud, Solveig; Kure, Cathrine F; Sidhu, Maan S; Nesbakken, Truls; Skaar, Ida

    2009-07-31

    This study investigate the diversity and dynamics of yeasts in the production processes of one unsmoked and two smoked dry-cured meat products of a Norwegian dry-cured meat production facility. A longitudinal observational study was performed to collect 642 samples from the meat, production materials, room installations and indoor and outdoor air of the production facility. Nutrient rich agar media were used to isolate the yeasts. Morphologically different isolates were re-cultivated in their pure culture forms. Both classical and molecular methods were employed for species identification. Totally, 401 yeast isolates belonging to 10 species of the following six genera were identified: Debaryomyces, Candida, Rhodotorula, Rhodosporidium, Cryptococcus and Sporidiobolus. Debaryomyces hansenii and Candida zeylanoides were dominant and contributed by 63.0% and 26.4% respectively to the total isolates recovered from both smoked and unsmoked products. The yeast diversity was higher at the pre-salting production processes with C. zeylanoides being the dominant. Later at the post-salting stages, D. hansenii occurred frequently. Laboratory studies showed that D. hansenii was more tolerant to sodium chloride and nitrite than C. zeylanoides. Smoking seems to have a killing or a temporary growth inhibiting effect on yeasts that extend to the start of the drying process. Yeasts were isolated only from 31.1% of the environmental samples. They belonged to six different species of which five of them were isolated from the meat samples too. Debaryomyces hansenii and Rhodotorula glutinis were dominant with a 62.6% and 22.0% contribution respectively. As none of the air samples contained D. hansenii, the production materials and room installations used in the production processes were believed to be the sources of contamination. The dominance of D. hansenii late in the production process replacing C. zeylanoides should be considered as a positive change both for the quality and safety

  14. CHARACTERISTICS OF THE WOOD DRYING PROCESS COMPLETED IN THE SAWMILLS IN THE CITY OF SINOP, MATO GROSSO

    Vinícius de Almeida dos Anjos

    2011-05-01

    Full Text Available Drying is the first and most important step in the process of wood industrialization and it aims to provide material with suitable characteristics for use. This operation must be planned and conducted the right way, because it determines the final product quality. This study aimed to characterize the drying process of wood made in sawmills in the city of Sinop, Mato Grosso, through qualitative and quantitative parameters, and identify common aspects and possible failures in the process. For this, data were collected through interviews in twelve sawmills in order to obtain information on the major species submitted to the drying process, drying methods, methods of stacking, consumer markets, methods of control of moisture content, major errors found in the drying yard or in the form of stacking, among others. The results show that Erisma uncinatum (cedrinho and Vochysia sp. (cambará are the main species subject to drying and marketed, especially in southern and southeastern Brazil. There were several flaws in the process as absence drying methods employing conventional chambers, lack of precise methods of controlling the final moisture content, improper stacking unaligned battens and drying patios with poor distribution of primary and secondary accesses.

  15. Effect of drying process assisted by high-pressure impregnation on protein quality and digestibility in red abalone (Haliotis rufescens).

    Cepero-Betancourt, Yamira; Oliva-Moresco, Patricio; Pasten-Contreras, Alexis; Tabilo-Munizaga, Gipsy; Pérez-Won, Mario; Moreno-Osorio, Luis; Lemus-Mondaca, Roberto

    2017-10-01

    Abalone (Haliotis spp.) is an exotic seafood product recognized as a protein source of high biological value. Traditional methods used to preserve foods such as drying technology can affect their nutritional quality (protein quality and digestibility). A 28-day rat feeding study was conducted to evaluate the effects of the drying process assisted by high-pressure impregnation (HPI) (350, 450, and 500 MPa × 5 min) on chemical proximate and amino acid compositions and nutritional parameters, such as protein efficiency ratio (PER), true digestibility (TD), net protein ratio, and protein digestibility corrected amino acid score (PDCAAS) of dried abalone. The HPI-assisted drying process ensured excellent protein quality based on PER values, regardless of the pressure level. At 350 and 500 MPa, the HPI-assisted drying process had no negative effect on TD and PDCAAS then, based on nutritional parameters analysed, we recommend HPI-assisted drying process at 350 MPa × 5 min as the best process condition to dry abalone. Variations in nutritional parameters compared to casein protein were observed; nevertheless, the high protein quality and digestibility of HPI-assisted dried abalones were maintained to satisfy the metabolic demands of human beings.

  16. Core characteristics of fast reactor cycle with simple dry pyrochemical processing

    Ikegami, Tetsuo

    2008-01-01

    Fast reactor core concept and core nuclear characteristics are studied for the application of the simple dry pyrochemical processing for fast reactor mixed oxide spent fuels, that is, the Compound Process Fuel Cycle, large FR core with of loaded fuels are recycled by the simple dry pyrochemical processing. Results of the core nuclear analyses show that it is possible to recycle FR spent fuel once and to have 1.01 of breeding ratio without radial blanket region. The comparison is made among three kinds of recycle fuels, LWR UO 2 spent fuel, LWR MOX spent fuel, and FR spent fuel. The recycle fuels reach an equilibrium state after recycles regardless of their starting heavy metal compositions, and the recycled FR fuel has the lowest radio-activity and the same level of heat generation among the recycle fuels. Therefore, the compound process fuel cycle has flexibility to recycle both LWR spent fuel and FR spent fuel. The concept has a possibility of enhancement of nuclear non-proliferation and process simplification of fuel cycle. (author)

  17. Use of a continuous twin screw granulation and drying system during formulation development and process optimization.

    Vercruysse, J; Peeters, E; Fonteyne, M; Cappuyns, P; Delaet, U; Van Assche, I; De Beer, T; Remon, J P; Vervaet, C

    2015-01-01

    Since small scale is key for successful introduction of continuous techniques in the pharmaceutical industry to allow its use during formulation development and process optimization, it is essential to determine whether the product quality is similar when small quantities of materials are processed compared to the continuous processing of larger quantities. Therefore, the aim of this study was to investigate whether material processed in a single cell of the six-segmented fluid bed dryer of the ConsiGma™-25 system (a continuous twin screw granulation and drying system introduced by GEA Pharma Systems, Collette™, Wommelgem, Belgium) is predictive of granule and tablet quality during full-scale manufacturing when all drying cells are filled. Furthermore, the performance of the ConsiGma™-1 system (a mobile laboratory unit) was evaluated and compared to the ConsiGma™-25 system. A premix of two active ingredients, powdered cellulose, maize starch, pregelatinized starch and sodium starch glycolate was granulated with distilled water. After drying and milling (1000 μm, 800 rpm), granules were blended with magnesium stearate and compressed using a Modul™ P tablet press (tablet weight: 430 mg, main compression force: 12 kN). Single cell experiments using the ConsiGma™-25 system and ConsiGma™-1 system were performed in triplicate. Additionally, a 1h continuous run using the ConsiGma™-25 system was executed. Process outcomes (torque, barrel wall temperature, product temperature during drying) and granule (residual moisture content, particle size distribution, bulk and tapped density, hausner ratio, friability) as well as tablet (hardness, friability, disintegration time and dissolution) quality attributes were evaluated. By performing a 1h continuous run, it was detected that a stabilization period was needed for torque and barrel wall temperature due to initial layering of the screws and the screw chamber walls with material. Consequently, slightly deviating

  18. Synthetic gas production from dry black liquor gasification process using direct causticization with CO2 capture

    Naqvi, Muhammad; Yan, Jinyue; Dahlquist, Erik

    2012-01-01

    Highlights: ► We study synthetic gas production from dry black liquor gasification system. ► Direct causticization eliminates energy intensive lime kiln reducing biomass use. ► Results show large SNG production potential at significant energy efficiency (58%). ► Substantial CO 2 capture potential plus CO 2 reductions from natural gas replacement. ► Significant transport fuel replacement especially in Sweden and Europe. -- Abstract: Synthetic natural gas (SNG) production from dry black liquor gasification (DBLG) system is an attractive option to reduce CO 2 emissions replacing natural gas. This article evaluates the energy conversion performance of SNG production from oxygen blown circulating fluidized bed (CFB) black liquor gasification process with direct causticization by investigating system integration with a reference pulp mill producing 1000 air dried tonnes (ADt) of pulp per day. The direct causticization process eliminates use of energy intensive lime kiln that is a main component required in the conventional black liquor recovery cycle with the recovery boiler. The paper has estimated SNG production potential, the process energy ratio of black liquor (BL) conversion to SNG, and quantified the potential CO 2 abatement. Based on reference pulp mill capacity, the results indicate a large potential of SNG production (about 162 MW) from black liquor but at a cost of additional biomass import (36.7 MW) to compensate the total energy deficit. The process shows cold gas energy efficiency of about 58% considering black liquor and biomass import as major energy inputs. About 700 ktonnes per year of CO 2 abatement i.e. both possible CO 2 capture and CO 2 offset from bio-fuel use replacing natural gas, is estimated. Moreover, the SNG production offers a significant fuel replacement in transport sector especially in countries with large pulp and paper industry e.g. in Sweden, about 72% of motor gasoline and 40% of total motor fuel could be replaced.

  19. Calculation of the process of vacuum drying of a metal-concrete container with spent nuclear fuel

    Karyakin, Yu. E.; Lavrent'ev, S. A.; Pavlyukevich, N. V.; Pletnev, A. A.; Fedorovich, E. D.

    2012-01-01

    An algorithm and results of calculation of the process of vacuum drying of a metal-concrete container intended for long-term "dry" storage of spent nuclear fuel are presented. A calculated substantiation of the initial amount of moisture in the container is given.

  20. Synthesis, processing behavior, and characterization of bismuth superconductors using freeze dried nitrate precursors

    Coppa, N.V.; Hults, W.L.; Smith, J.L.; Brynestad, J.

    1994-01-01

    The synthesis of Bi 2-x Pb x Sr 2 Ca 2 Cu 3 O 10 (Bi2223) powders from a freeze dried nitrate precursor is reported here. We examine the composition and morphology of the precursor material, describe the chemistry and kinetics of product formation, and evaluate the phase composition and superconducting properties of the products. A nitrate solution containing the appropriate ratio of cations was rapidly frozen and then freeze dried at low temperatures to form an atomic mixture of the component salts. The thermal processing of the freeze dried material consisted of three steps: (i) dehydration, (ii) denitration, and (iii) solid state reaction to form the Bi2223 superconducting product. Calcium substituted bismuthates and strontium-substituted calcium cuprate, not Bi2201, are the intermediates between the nitrates and the superconducting products. These highly disordered phases rapidly transform into Bi2212 or Bi2223 at higher temperatures (>790 degree C). The kinetics of product formation was studied using XRD analysis and magnetic susceptibility. The kinetics were shown to follow the nucleation and growth mechanism. Bi2223 formed after only 30 min at a few degrees below the melting point, and after 37 h Bi2223 products exhibited excellent phase composition and magnetic susceptibility characteristics

  1. Dry coating of solid dosage forms: an overview of processes and applications.

    Foppoli, Anastasia Anna; Maroni, Alessandra; Cerea, Matteo; Zema, Lucia; Gazzaniga, Andrea

    2017-12-01

    Dry coating techniques enable manufacturing of coated solid dosage forms with no, or very limited, use of solvents. As a result, major drawbacks associated with both organic solvents and aqueous coating systems can be overcome, such as toxicological, environmental, and safety-related issues on the one hand as well as costly drying phases and impaired product stability on the other. The considerable advantages related to solventless coating has been prompting a strong research interest in this field of pharmaceutics. In the article, processes and applications relevant to techniques intended for dry coating are analyzed and reviewed. Based on the physical state of the coat-forming agents, liquid- and solid-based techniques are distinguished. The former include hot-melt coating and coating by photocuring, while the latter encompass press coating and powder coating. Moreover, solventless techniques, such as injection molding and three-dimensional printing by fused deposition modeling, which are not purposely conceived for coating, are also discussed in that they would open new perspectives in the manufacturing of coated-like dosage forms.

  2. Wet and dry deposition and resuspension of AFCT/TFCT fuel processing radionuclides. Final report

    Slinn, W.G.N.; Katen, P.C.; Wolf, M.A.; Loveland, W.D.; Radke, L.F.; Miller, E.L.; Ghannam, L.J.; Reynolds, B.W.; Vickers, D.

    1979-09-01

    After short summary and introductory chapters, Chapter IV contains a critical analysis of available parameterizations for resuspension and for wet and dry removal processes and recommends interim parameterizations for use in radiation dose calculations. Chapter V describes methods and experimental results from field studies of in-cloud vs below-cloud scavenging, precipitation efficiency, and modifications of aerosols by clouds. In Chapter VI are contained descriptions of methods and results from four different approaches to the problem of measuring the dry deposition velocities of submicron aerosol particles depositing on vegetation. Chapter VII describes experimental results from a study of resuspension and weathering of tracer aerosol particles deposited on soil, grass and gravel; typical resuspension rates were found to be of the order of 10 -8 s -1 and it is recommended that the concept of weathering be reassessed. In Chapter VIII, National Weather Service data are used to obtain Lagrangian statistics for use in a regional-scale study of wet and dry removal. Chapter IX develops new concepts in reservoir models for application at regional to global scales. In the final chapter are some comments about the results found in this study and recommendations for future research

  3. Simulation and energy efficiency analysis of desiccant wheel systems for drying processes

    De Antonellis, Stefano; Joppolo, Cesare Maria; Molinaroli, Luca; Pasini, Alberto

    2012-01-01

    In drying processes it is necessary to appropriately control air humidity and temperature in order to enhance water evaporation from product surface. The aim of this work is to investigate several HVAC configurations for product drying based on desiccant wheels, in order to find systems which reach high primary energy savings through the appropriate integration of refrigerating machines, adsorption wheels and cogenerative engines. Simulations are carried out for different values of sensible to latent ambient load ratio and the effect of ambient and outside air conditions is evaluated for each configuration. It is shown that primary energy savings can reach 70–80% compared to the reference technology based on a cooling coil. With respect to works available in literature, the results of this study keep a general approach and they can be used as a simple tool for preliminary assessment in a wide range of applications. -- Highlights: ► Several HVAC systems for product drying based on desiccant wheels are investigated. ► The sensible to latent ambient load ratio influences the choice of the best system. ► Energy savings can reach 80% compared to the technology based on a cooling coil. ► Simulation results can be used for preliminary assessment in many applications.

  4. Production of ethanol from winter barley by the EDGE (enhanced dry grind enzymatic process

    Kurantz M

    2010-04-01

    Full Text Available Abstract Background US legislation requires the use of advanced biofuels to be made from non-food feedstocks. However, commercialization of lignocellulosic ethanol technology is more complex than expected and is therefore running behind schedule. This is creating a demand for non-food, but more easily converted, starch-based feedstocks other than corn that can fill the gap until the second generation technologies are commercially viable. Winter barley is such a feedstock but its mash has very high viscosity due to its high content of β-glucans. This fact, along with a lower starch content than corn, makes ethanol production at the commercial scale a real challenge. Results A new fermentation process for ethanol production from Thoroughbred, a winter barley variety with a high starch content, was developed. The new process was designated the EDGE (enhanced dry grind enzymatic process. In this process, in addition to the normal starch-converting enzymes, two accessory enzymes were used to solve the β-glucan problem. First, β-glucanases were used to hydrolyze the β-glucans to oligomeric fractions, thus significantly reducing the viscosity to allow good mixing for the distribution of the yeast and nutrients. Next, β-glucosidase was used to complete the β-glucan hydrolysis and to generate glucose, which was subsequently fermented in order to produce additional ethanol. While β-glucanases have been previously used to improve barley ethanol production by lowering viscosity, this is the first full report on the benefits of adding β-glucosidases to increase the ethanol yield. Conclusions In the EDGE process, 30% of total dry solids could be used to produce 15% v/v ethanol. Under optimum conditions an ethanol yield of 402 L/MT (dry basis or 2.17 gallons/53 lb bushel of barley with 15% moisture was achieved. The distillers dried grains with solubles (DDGS co-product had extremely low β-glucan (below 0.2% making it suitable for use in both ruminant

  5. Criticality safety evaluation report for the Cold Vacuum Drying Facility's process water handling system

    Roblyer, S.D.

    1998-01-01

    This report addresses the criticality concerns associated with process water handling in the Cold Vacuum Drying Facility (CVDF). The controls and limitations on equipment design and operations to control potential criticality occurrences are identified. The effectiveness of equipment design and operation controls in preventing criticality occurrences during normal and abnormal conditions is evaluated and documented in this report. Spent nuclear fuel (SNF) is removed from existing canisters in both the K East and K West Basins and loaded into a multicanister overpack (MCO) in the K Basin pool. The MCO is housed in a shipping cask surrounded by clean water in the annulus between the exterior of the MCO and the interior of the shipping cask. The fuel consists of spent N Reactor and some single pass reactor fuel. The MCO is transported to the CVDF near the K Basins to remove process water from the MCO interior and from the shipping cask annulus. After the bulk water is removed from the MCO, any remaining free liquid is removed by drawing a vacuum on the MCO's interior. After cold vacuum drying is completed, the MCO is filled with an inert cover gas, the lid is replaced on the shipping cask, and the MCO is transported to the Canister Storage Building. The process water removed from the MCO contains fissionable materials from metallic uranium corrosion. The process water from the MCO is first collected in a geometrically safe process water conditioning receiver tank. The process water in the process water conditioning receiver tank is tested, then filtered, demineralized, and collected in the storage tank. The process water is finally removed from the storage tank and transported from the CVDF by truck

  6. Effects of physical parameters on the heat and mass transfer characteristics in freeze-drying processes of fruits and vegetables

    Guo, Yuming; Liu, Lijuan; Liang, Li [Shanxi Agricultural Univ. (China). Coll. of Engineering and Technology], E-mail: guoyuming99@sina.com

    2008-07-01

    Studying the effects mechanism of material physical parameters on the heat and mass transfer characteristics, the process parameters and energy consumption during freeze-drying process is of importance in improving the vacuum freeze-drying process with low energy consumption. In this paper, the sliced and mashed carrots of one variety were selected to perform the vacuum freeze-drying experiments. First, the variation laws of surface temperatures and sublimation front temperatures of the two shapes samples during the freeze-drying processes were analyzed, and it was verified that the process of sliced carrots is controlled by mass transfer, while that of the mashed ones is heat-transfer control. Second, the variations of water loss rate, energy consumption and temperature of the two shapes samples under the appropriate heating plate temperature and the different drying chamber pressure were analyzed. In addition, the effects of thermal conductivity and thermal diffusivity on freeze-drying time and process parameters were discussed by utilizing the theory of heat and mass transfer. In conclusion, under the heat transfer condition, the temperature of the heating plate should be as high as possible within the permitted range, and the drying chamber pressure should be set at optimal level. While under the mass transport-limited condition, the pressure level need to be altered in short time. (author)

  7. INVESTIGATION OF THE POSSIBILITY OF OBTAINING DRY BASES FROM PROCESSED FISH PRODUCTS OF LITTLE VALUE

    O. P. Dvoryaninova

    2014-01-01

    Full Text Available Summary. Competitive advantages of this direction of researches are in justification of actions and offers on a technical provision of production of a dry fish basis from meat- and bone residue of pond fishes that will allow to produce fast foods of high quality and biological value (broths, soups, sauces, to expand the assortment taking into account market demand, to introduce the new forms of food convenient in storage and use at home and outside as well as for special food. The first courses on dry fish broth are easily digestible, with the high contents of micro and macro elements in the quantity of them they surpass meat broths. Their other advantage is the content of the polynonsaturated fatty acids neutralizing negative impact of substances, destroying tendons, ligaments and cartilage in the human body, thereby eliminating joint pains that is especially important for the determined groups of the population, for example, the military personnel, sportsmen, etc. In addition, this technology includes sparing modes of processing of raw materials, keeping thereby native properties of useful substances (protein, fat as much as possible. Researches on selection of an optimum ratio of the heads and the bones providing high organoleptic rates of broths on their basis were carried out to produce dry fish bases. Conditions and parameters of convective drying of little value products of cutting of silver carp and cod are determined. The results allow to draw a preliminary conclusion on the possibility of creation a new technology of powdery products for broths fast preparation. The developed technology is of great importance in the creation of waste-free and low-waste production at the enterprises of fishery industry of the Russian Federation.

  8. Drying process in the formation of sol-gel derived TiO2 ceramic membrane

    Kumar, K.N.P.; Kumar, K.N.P.; Zaspalis, V.T.; Zaspalis, V.T.; Keizer, Klaas; Burggraaf, Anthonie; Burggraaf, A.J.

    1993-01-01

    Accurate drying data for thin titania gel layers dried at 40°C and 20% relative humidity (RH) are given. The drying rate versus free moisture content diagram should show three regions as predicted by the classical drying theory. They are the constant rate period, the first falling rate period and

  9. Zeolite Formation and Weathering Processes in Dry Valleys of Antartica: Martian Analogs

    Gibson, E. K., Jr.; Wentworth, S. J.; McKay, D. S.; Socki, R. A.

    2004-01-01

    Terrestrial weathering processes in cold-desert climates such as the Dry Valleys of Antarctica may provide an excellent analog to chemical weathering and diagenesis of soils on Mars. Detailed studies of soil development and the chemical and mineralogical alterations occurring within soil columns in Wright Valley, Antarctica show incredible complexity in the upper meter of soil. Previous workers noted the ice-free Dry Valleys are the best terrestrial approximations to contemporary Mars. Images returned from the Pathfinder and Spirit landers show similarities to surfaces observed within the Dry Valleys. Similarities to Mars that exist in these valleys are: mean temperatures always below freezing (-20 C), no rainfall, sparse snowfall-rapidly removed by sublimation, desiccating winds, diurnal freeze-thaw cycles (even during daylight hours), low humidity, oxidative environment, relatively high solar radiation and low magnetic fields . The Dry Valley soils contain irregular distributions and low abundances of soil microorganisms that are somewhat unusual on Earth. Physical processes-such as sand abrasion-are dominant mechanisms of rock weathering in Antarctica. However, chemical weathering is also an important process even in such extreme climates. For example, ionic migration occurs even in frozen soils along liquid films on individual soil particles. It has also been shown that water with liquid-like properties is present in soils at temperatures on the order of approx.-80 C and it has been observed that the percentage of oxidized iron increases with increasing soil age and enrichments in oxidized iron occurs toward the surface. The presence of evaporates is evident and appear similar to "evaporite sites" within the Pathfinder and Spirit sites. Evaporites indicate ionic migration and chemical activity even in the permanently frozen zone. The presence of evaporates indicates that chemical weathering of rocks and possibly soils has been active. Authogenic zeolites have

  10. Degradability of dry matter and crude protein of dry grains and wet grain silages from different processing corn hybrids (Zea mays

    Wagner dos Reis

    2013-03-01

    Full Text Available The objective of this work was to evaluate the effect of processing two corn hybrids conserved, dry and humid grains, the dry matter (DM and crude protein (CP degradability in situ. The particle size was determined and difference was verified in MGD (Medium Geometric Diameter of processed ingredients. Three sheep were used with rumen canulated, in a completely randomized design, using a factorial outline 2 x 2 x 3, being two corn hybrid, two conservation methods and three processing forms (whole, coarsely and finely ground, with five times of incubation (3, 6, 12, 24 and 48 hours. The fraction A in SDC (silage of dent corn of DM was superior to GDC (grain of dent corn in all of the particles size. The ensiling process increased the DM solubility, reducing the fraction B in comparison to dry grain. The values regarding the fractions DP and DE the 5% per hour of the protein, were larger for SDC and GDC, it presents a decreasing when the incubation time advances. The fermentation rate was superior for SDC and GDC. The ensiling process has positive effect in the decreasing of DM and CP in comparison to GDC.

  11. Fabrication of Li{sub 2}TiO{sub 3} pebbles by a freeze drying process

    Lee, Sang-Jin, E-mail: lee@mokpo.ac.kr [Department of Advanced Materials Science and Engineering, Mokpo National University, Muan 534-729 (Korea, Republic of); Park, Yi-Hyun [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Yu, Min-Woo [Department of Advanced Materials Science and Engineering, Mokpo National University, Muan 534-729 (Korea, Republic of)

    2013-11-15

    Li{sub 2}TiO{sub 3} pebbles were successfully fabricated by using a freeze drying process. The Li{sub 2}TiO{sub 3} slurry was prepared using a commercial powder of particle size 0.5–1.5 μm and the pebble pre-form was prepared by dropping the slurry into liquid nitrogen through a syringe needle. The droplets were rapidly frozen, changing their morphology to spherical pebbles. The frozen pebbles were dried at −10 °C in vacuum. To make crack-free pebbles, some glycerin was employed in the slurry, and long drying time and a low vacuum condition were applied in the freeze drying process. In the process, the solid content in the slurry influenced the spheroidicity of the pebble green body. The dried pebbles were sintered at 1200 °C in an air atmosphere. The sintered pebbles showed almost 40% shrinkage. The sintered pebbles revealed a porous microstructure with a uniform pore distribution and the sintered pebbles were crushed under an average load of 50 N in a compressive strength test. In the present study, a freeze drying process for fabrication of spherical Li{sub 2}TiO{sub 3} pebbles is introduced. The processing parameters, such as solid content in the slurry and the conditions of freeze drying and sintering, are also examined.

  12. Elastic stability of silicone ferrofluid internal tamponade (SFIT) in retinal detachment surgery

    Voltairas, P.A. E-mail: pvolter@cs.uoi.gr; Fotiadis, D.I.; Massalas, C.V

    2001-07-01

    It has been argued that silicone ferrofluid internal tamponade (SFIT) can provide (360 deg.) tamponade of the retina in retinal detachment surgery. Provided that the produced SFIT is biocompatible, exact knowledge is needed of its elastic stability in the magnetic field produced by the semi-solid magnetic silicon band (MSB) used as a scleral buckle. We propose a quantitative, phenomenological model to estimate the critical magnetic field produced by the MSB that 'closes' retinal tears and results in the reattachment of the retina. The magnetic 'deformation' of SFIT is modeled in accordance with the deformation of a ferrofluid droplet in an external magnetic field.

  13. Ferrofluid aggregation in chains under the influence of a magnetic field

    Ivanov, Alexey O.; Kantorovich, Sofia S.; Mendelev, Valentin S.; Pyanzina, Elena S.

    2006-01-01

    The paper is devoted to the basic problem of chain aggregate formation in magnetic fluids under the influence of an external magnetic field. Chain distribution in dynamic equilibrium is obtained on the basis of free energy minimization method under the condition when the interparticle dipole-dipole interaction between the nearest neighboring ferroparticles in each chain is taken into account. The modified mean field approach is used for considering the dipole-dipole interaction between all particles in a ferrofluid. The model describes well the molecular dynamics simulations of magnetostatic properties for monodisperse ferrofluids containing chain aggregates

  14. Tribological investigations of the applicability of surface functionalization for dry extrusion processes

    Teller, Marco; Prünte, Stephan; Ross, Ingo; Temmler, André; Schneider, Jochen M.; Hirt, Gerhard

    2017-10-01

    Cold extrusion processes are characterized by large relative contact stresses combined with a severe surface enlargement of the workpiece. Under these process conditions a high risk for galling of workpiece material to the tool steel occurs especially in processing of aluminum and aluminum alloys. In order to reduce adhesive wear lubricants for separation of workpiece and tool surfaces are used. As a consequence additional process steps (e.g. preparation and cleaning of workpieces) are necessary. Thus, the realization of a dry forming process is aspired from an environmental and economic perspective. In this paper a surface functionalization with self-assembled-monolayers (SAM) of the tool steels AISI D2 (DIN 1.2379) and AISI H11 (DIN 1.2343) is evaluated by a process-oriented tribological test. The tribological experiment is able to resemble and scale the process conditions of cold extrusion related to relative contact stress and surface enlargement for the forming of pure aluminum (Al99.5). The effect of reduced relative contact stress, surface enlargement and relative velocity on adhesive wear and tool lifetime is evaluated. Similar process conditions are achievable by different die designs with decreased extrusion ratios and adjusted die angles. The effect of surface functionalization critically depends on the substrate material. The different microstructure and the resulting differences in surface chemistry of the two tested tool steels appear to affect the performance of the tool surface functionalization with SAM.

  15. Physical quality characteristics of the microwave-dried breadfruit powders due to different processing conditions

    Taruna, I.; Hakim, A. L.; Sutarsi

    2018-03-01

    Production of breadfruit powder has been an option to make easy its uses in various food processing. Accordingly, there is a need recently to apply advanced drying method, i.e. microwave drying, for improving quality since conventional methods produced highly variable product quality and required longer process. The present work was aimed to study the effect of microwave power and grinding time on physical quality of breadfruit powders. The experiment was done initially by drying breadfruit slices in a microwave dryer at power level of 420, 540, and 720 W and then grinding for 3, 5, and 7 min to get powdery product of less than 80 mesh. The physical quality of breadfruit powders were measured in terms of fineness modulus (FM), average particle size (D), whiteness (WI), total color difference (ΔE), water absorption (Wa), oil absorption (La), bulk density (ρb) and consistency gel (Gc). The results showed that physical quality of powders and its ranged-values included the FM (2.08-2.62), D (0.44-0.68 mm), WI (75.2-77.9), ΔE (7.4-10.5), Wa (5.5-6.2 ml/g), La (0.7-0.9 ml/g), ρb (0.62-0.70 g/cm3) and Gc (41.3-46.8 mm). The experiment revealed that variation of microwave power and grinding time affected significantly the quality of the breadfruit powders. However, microwave power was more dominant factor to affect quality of breadfruit powder in comparison to the grinding time.

  16. Overall Quality of Fruits and Vegetables Products Affected by the Drying Processes with the Assistance of Vacuum-Microwaves.

    Figiel, Adam; Michalska, Anna

    2016-12-30

    The seasonality of fruits and vegetables makes it impossible to consume and use them throughout the year, thus numerous processing efforts have been made to offer an alternative to their fresh consumption and application. To prolong their availability on the market, drying has received special attention as currently this method is considered one of the most common ways for obtaining food and pharmaceutical products from natural sources. This paper demonstrates the weakness of common drying methods applied for fruits and vegetables and the possible ways to improve the quality using different drying techniques or their combination with an emphasis on the microwave energy. Particular attention has been drawn to the combined drying with the assistance of vacuum-microwaves. The quality of the dried products was ascribed by chemical properties including the content of polyphenols, antioxidant capacity and volatiles as well as physical parameters such as color, shrinkage, porosity and texture. Both these fields of quality classification were considered taking into account sensory attributes and energy aspects in the perspective of possible industrial applications. In conclusion, the most promising way for improving the quality of dried fruit and vegetable products is hybrid drying consisting of osmotic dehydration in concentrated fruit juices followed by heat pump drying and vacuum-microwave finish drying.

  17. Overall Quality of Fruits and Vegetables Products Affected by the Drying Processes with the Assistance of Vacuum-Microwaves

    Adam Figiel

    2016-12-01

    Full Text Available The seasonality of fruits and vegetables makes it impossible to consume and use them throughout the year, thus numerous processing efforts have been made to offer an alternative to their fresh consumption and application. To prolong their availability on the market, drying has received special attention as currently this method is considered one of the most common ways for obtaining food and pharmaceutical products from natural sources. This paper demonstrates the weakness of common drying methods applied for fruits and vegetables and the possible ways to improve the quality using different drying techniques or their combination with an emphasis on the microwave energy. Particular attention has been drawn to the combined drying with the assistance of vacuum-microwaves. The quality of the dried products was ascribed by chemical properties including the content of polyphenols, antioxidant capacity and volatiles as well as physical parameters such as color, shrinkage, porosity and texture. Both these fields of quality classification were considered taking into account sensory attributes and energy aspects in the perspective of possible industrial applications. In conclusion, the most promising way for improving the quality of dried fruit and vegetable products is hybrid drying consisting of osmotic dehydration in concentrated fruit juices followed by heat pump drying and vacuum-microwave finish drying.

  18. Performance of A Horizontal Cylinder Type Rotary Dryer for Drying Process ofOrganic Compost from Solid Waste Cocoa Pod

    Sukrisno Widyotomo

    2008-07-01

    Full Text Available Cocoa pod husk is the bigest component of cocoa pod, about 70% of total ht of mature pod, and to potentially used as organic compost source. Poten tial solid waste of cocoa pod husk from a cocoa processing centre is about 15— 22 m3/ha/year. A cocoa plantation needs about 20—30 ton/ha/year of organic matters. One of important steps in compos processing technology of cocoa pod solid waste is drying process. Organic compost with 20% moisture content is more easy in handling, application, storage and distribution. Indonesian Coffee and Cocoa Research Institute has designed and tested a horizontal cylinder type rotary dryer for drying process of organic compos from solid waste cocoa pod with kerosene burner as energy sources. The objective of this research is to study performance of a horizontal cylinder type rotary dryer using kerosene burner as energy source for drying process of organic compost from solid waste cocoa pod. The material used was solid waste cocoa pod with 70—75% moisture content (wet basis, 70% size particle larger than 4.76 mm, and 30% size particle less than 4.76 mm, 690—695 kg/m3 bulk density. Drying process temperatures treatment were 60OC, 80OC, and 100OC, and cylinder rotary speed treatments were 7 rpm, 10 rpm, dan 16 rpm. The results showed that dryer had capacity about 102—150 kg/h depend on drying temperature and cylinder rotary speed. Optimum operation condition at 100OC drying temperature, and 10 rpm cylinder rotary speed with drying time to reach final moisture content of 20% was 1,6 h, capacity 136,14 kg/ h, bulk density 410 kg/m3, porocity 45,15%, kerosene consumption as energy source was 2,57 l/h, and drying efficiency 68,34%. Key words : cocoa, drying, rotary dryer, compost, waste

  19. [Analysis of dynamic changes of flavonoids and alkaloids during different drying process of Morus alba leaves].

    Bai, Yong-liang; Duan, Jin-ao; Su, Shu-lan; Qian, Ye-fei; Qian, Da-wei; Ouyang, Zhen

    2014-07-01

    To find out dynamic changes of flavonoids and alkaloids in Morus alba leaves by analyzing influence of different drying method and drying degrees, in order to provide evidence for quality evaluation of Morus alba leaves. Different drying methods, programmed temperature methods and constant temperature methods were adopted to dry Morus alba leaves samples respectively. Contents of flavonoids and alkaloids were analyzed by HPLC-PDA and LC-TQ/MS respectively. It's shown obviously that the content of flavonoids were influenced heavily by different drying methods. Methods that suitable for flavonoids were freezing-dried > shade-dried > dried > sun-dried > microwave-dried > infrared-dried; Methods that suitable for alkaloids were freezing-dried > shade-dried > dried > sun-dried > infrared-dried > microwave-dried. The 55 -65 degrees C group was shown to be the lowest in both flavonoids and DNJ while the 85 - 95 degrees C group was shown to be the best for DNJ. For fagomine, the 45 degrees C group was shown to be the lowest concentrations while the 95 - 105 degrees C group was shown to be the highest. Samples with different moisture were shown to be different in content of flavonoids and alkaloids. And samples with 10% moisture contain highest flavonoids while those with 30% - 50% moisture contain lowest flavonoids. Content of DNJ and fagomine raised as moisture decreasing. In addition, the 55 - 65 degrees C group was better than the 95 -105 degrees C one in alkaloids content. The results provide optimal drying methods and condition for drying Morus alba leaves, and foundations for uncovering biochemical transform of Morus alba leaves.

  20. Effect of deposition temperature and thermal annealing on the dry etch rate of a-C: H films for the dry etch hard process of semiconductor devices

    Lee, Seung Moo; Won, Jaihyung; Yim, Soyoung; Park, Se Jun; Choi, Jongsik; Kim, Jeongtae; Lee, Hyeondeok; Byun, Dongjin

    2012-01-01

    thermal annealing of the high density, as-deposited a-C:H films. Furthermore, not only the density itself but also the variation of density with thermal annealing need to be elucidated in order to understand the dry etch properties of annealed a-C:H films. - Highlights: ► A-C:H(amorphous carbon) films are grown for using hard mask in dry etch process by plasma-enhanced chemical vapor deposition and annealed. ► Physical, chemical and mechanical properties of grown amorphous carbon films are changed by hydrogen and hydrocarbon contents, be determined by deposition and annealing temperature. ► Dry etch rate of a-C:H films is decreased and the film density increased through thermal annealing with high density, low hydrogen content, as-deposited film.

  1. Theoretical and experimental investigations of ferrofluids for guiding and detecting liquids in the subsurface. FY 1997 annual report

    Moridis, G.J.; Borglin, S.E.; Oldenburg, C.M.; Becker, A.

    1998-03-01

    Ferrofluids are stable colloidal suspensions of magnetic particles in various carrier liquids with high saturation magnetizations, which can be manipulated in virtually any fashion, defying gravitational or viscous forces in response to external magnetic fields. In this report, the authors review the results of their investigation of the potential of ferrofluids (1) to accurately and effectively guide reactants (for in-situ treatment) or barrier liquids (low-viscosity permeation grouts) to contaminated target zones in the subsurface using electromagnetic forces, and (2) to trace the movement and position of liquids injected in the subsurface using geophysical methods. They investigate the use of ferrofluids to enhance the efficiency of in-situ treatment and waste containment through (a) accurate guidance and delivery of reagent liquids to the desired subsurface contamination targets and/or (b) effective sweeping of the contaminated zone as ferrofluids move from the application point to an attracting magnet/collection point. They also investigate exploiting the strong magnetic signature of ferrofluids to develop a method for monitoring of liquid movement and position during injection using electromagnetic methods. The authors demonstrated the ability to induce ferrofluid movement in response to a magnetic field, and measured the corresponding magnetopressure. They demonstrated the feasibility of using conventional magnetometry for detecting subsurface zones of various shapes containing ferrofluids for tracing liquids injected for remediation or barrier formation. Experiments involving spherical, cylindrical and horizontal slabs showed a very good agreement between predictions and measurements.

  2. Theoretical and experimental investigations of ferrofluids for guiding and detecting liquids in the subsurface. FY 1997 annual report

    Moridis, G.J.; Borglin, S.E.; Oldenburg, C.M.; Becker, A.

    1998-03-01

    Ferrofluids are stable colloidal suspensions of magnetic particles in various carrier liquids with high saturation magnetizations, which can be manipulated in virtually any fashion, defying gravitational or viscous forces in response to external magnetic fields. In this report, the authors review the results of their investigation of the potential of ferrofluids (1) to accurately and effectively guide reactants (for in-situ treatment) or barrier liquids (low-viscosity permeation grouts) to contaminated target zones in the subsurface using electromagnetic forces, and (2) to trace the movement and position of liquids injected in the subsurface using geophysical methods. They investigate the use of ferrofluids to enhance the efficiency of in-situ treatment and waste containment through (a) accurate guidance and delivery of reagent liquids to the desired subsurface contamination targets and/or (b) effective sweeping of the contaminated zone as ferrofluids move from the application point to an attracting magnet/collection point. They also investigate exploiting the strong magnetic signature of ferrofluids to develop a method for monitoring of liquid movement and position during injection using electromagnetic methods. The authors demonstrated the ability to induce ferrofluid movement in response to a magnetic field, and measured the corresponding magnetopressure. They demonstrated the feasibility of using conventional magnetometry for detecting subsurface zones of various shapes containing ferrofluids for tracing liquids injected for remediation or barrier formation. Experiments involving spherical, cylindrical and horizontal slabs showed a very good agreement between predictions and measurements

  3. The study of some physical properties and energy aspects of potatoes drying process by the infrared-vacuum method

    N Hafezi

    2016-09-01

    Full Text Available Introduction Potato (Solanumtuberosum L. is one of the unique and most potential crops having high productivity, supplementing major food requirement in the world. Drying is generally carried out for two main reasons, one to reduce the water activity which eventually increases the shelf life of food and second to reduce the weight and bulk of food for cheaper transport and storage. The quality evaluation of the dried product was carried out on the basis of response variables such as rehydration ratio, shrinkage percentage, color and the overall acceptability. Drying is the most energy intensive process in food industry. Therefore, new drying techniques and dryers must be designed and studied to minimize the energy cost in drying process. Considering the fact that the highest energy consumption in agriculture is associated with drying operations, different drying methods can be evaluated to determine and compare the energy requirements for drying a particular product. Thermal drying operations are found in almost all industrial sectors and are known, according to various estimates, to consume 10-25% of the national industrial energy in the developed world. Infrared radiation drying has the unique characteristics of energy transfer mechanism. Kantrong et al. (2012 were studied the drying characteristics and quality of shiitake mushroom undergoing microwave-vacuum combined with infrared drying. Motevali et al. (2011 were evaluated energy consumption for drying of mushroom slices using various drying methods including hot air, microwave, vacuum, infrared, microwave-vacuum and hot air-infrared. The objectives of this research were to experimental study of drying kinetics considering quality characteristics including the rehydration and color distribution of potato slices in a vacuum- infrared dryer and also assessment of specific energy consumption and thermal utilization efficiency of potato slices during drying process. Materials and Methods A

  4. Implementation of hazard analysis and critical control point (HACCP) in dried anchovy production process

    Citraresmi, A. D. P.; Wahyuni, E. E.

    2018-03-01

    The aim of this study was to inspect the implementation of Hazard Analysis and Critical Control Point (HACCP) for identification and prevention of potential hazards in the production process of dried anchovy at PT. Kelola Mina Laut (KML), Lobuk unit, Sumenep. Cold storage process is needed in each anchovy processing step in order to maintain its physical and chemical condition. In addition, the implementation of quality assurance system should be undertaken to maintain product quality. The research was conducted using a survey method, by following the whole process of making anchovy from the receiving raw materials to the packaging of final product. The method of data analysis used was descriptive analysis method. Implementation of HACCP at PT. KML, Lobuk unit, Sumenep was conducted by applying Pre Requisite Programs (PRP) and preparation stage consisting of 5 initial stages and 7 principles of HACCP. The results showed that CCP was found in boiling process flow with significant hazard of Listeria monocytogenesis bacteria and final sorting process with significant hazard of foreign material contamination in the product. Actions taken were controlling boiling temperature of 100 – 105°C for 3 - 5 minutes and training for sorting process employees.

  5. Optimization of drying process of Zea Mays malt to use as alternative source of amylolytics enzymes

    Joana Paula Menezes Biazus

    2005-06-01

    Full Text Available This work aimed to study the drying process optimization of maize (Zea Mays malt for obtaining maize malt, without affecting enzymatic activity of alpha e beta-amylases from maize malt. Results showed that dryer operation must occur in zone at 54°C and 5.18-6 h process time. The maize malt obtained had good enzymatic properties.Este trabalho objetivou a otimização da secagem do malte de milho (Zea Mays para obter um malte sem afetar a atividade das enzimas presentes neste, alfa e beta -amilases. Os resultados mostraram que a operação do secador deve ser feita a 54°C e entre 5,18-6 h de processo. O malte obtido possuiu boas propriedades enzimáticas.

  6. Powder stickiness in milk drying: uncertainty and sensitivity analysis for process understanding

    Ferrari, Adrián; Gutiérrez, Soledad; Sin, Gürkan

    2017-01-01

    A powder stickiness model based in the glass transition temperature (Gordon – Taylor equations) was built for a production scale milk drying process (including a spray chamber, and internal/external fluid beds). To help process understanding, the model was subjected to sensitivity analysis (SA...... for nonlinear error propagation was selected as the main UA approach. SA results show an important local sensitivity on the spray dryer, but at the end of the internal fluid bed (critical point for stickiness) minor local sensitivities were observed. Feed concentrate moisture was found as the input with major...... global sensitivity on the glass transition temperature at the critical point, so it could represent a key variable for helping on stickiness control. UA results show the major model predictions uncertainty on the spray dryer, but it does not represent a stickiness issue since the product...

  7. Analysis of process factors of dry fermented salami to control Listeria monocytogenes

    Enrico Novelli

    2017-01-01

    Full Text Available Challenge tests are a clear opportunity for manufacturers interested in the evaluation of their management system with the aim to reduce the spread of foodborne pathogens. This is a main concern especially in ready-to-eat food in relation to the risk associated with Listeria monocytogenes. For small and medium-scale food industry the manufacturing practices and products formulation are characterised by a wider variability and poor repeatability. The use of ad hoc challenge test and the comparison among different processing systems are strongly required. This paper reports a preliminary comparison among different challenge tests (n=12 commissioned by three manufacturers of raw-fermented salami during a period of three years (2013-2016. The challenge tests were designed to evaluate the growth potential (δ of L. monocytogenes during the whole processing period of the salami. The doughs were prepared according to different formulations: the simplest formulation was represented by the use of salt, potassium nitrate, black pepper and starter cultures, while the most composited formulations also included the use of sugars and ascorbic acid in addition to nitrite salt. All the processing steps were conducted within an experimental laboratory dedicated for the processing of meat. After stuffing, the salami were dried and ripened under temperature and relative humidity control. The sugar inclusion can be considered as a protective factor, while the drying step at high temperature (above 20°C was associated with higher δ values (δ>0.5 log10 cfu/g. The addition of starter cultures, and the subsequent acidification highlighted the importance of pH as the parameter able to affect the L. monocytogenes growth.

  8. Analysis of Process Factors of Dry Fermented Salami to Control Listeria Monocytogenes

    Novelli, Enrico; Dal Santo, Lucia; Balzan, Stefania; Cardazzo, Barbara; Spolaor, Dino; Lombardi, Angiolella; Carraro, Lisa; Fasolato, Luca

    2017-01-01

    Challenge tests are a clear opportunity for manufacturers interested in the evaluation of their management system with the aim to reduce the spread of foodborne pathogens. This is a main concern especially in ready-to-eat food in relation to the risk associated with Listeria monocytogenes. For small and medium-scale food industry the manufacturing practices and products formulation are characterised by a wider variability and poor repeatability. The use of ad hoc challenge test and the comparison among different processing systems are strongly required. This paper reports a preliminary comparison among different challenge tests (n=12) commissioned by three manufacturers of raw-fermented salami during a period of three years (2013-2016). The challenge tests were designed to evaluate the growth potential (δ) of L. monocytogenes during the whole processing period of the salami. The doughs were prepared according to different formulations: the simplest formulation was represented by the use of salt, potassium nitrate, black pepper and starter cultures, while the most composited formulations also included the use of sugars and ascorbic acid in addition to nitrite salt. All the processing steps were conducted within an experimental laboratory dedicated for the processing of meat. After stuffing, the salami were dried and ripened under temperature and relative humidity control. The sugar inclusion can be considered as a protective factor, while the drying step at high temperature (above 20°C) was associated with higher δ values (δ>0.5 log10 cfu/g). The addition of starter cultures, and the subsequent acidification highlighted the importance of pH as the parameter able to affect the L. monocytogenes growth. PMID:28462203

  9. Mathematical experimental modeling for muffle furnace drying process of municipal sewage sludge in Beijing and Osaka

    Li, Xinyi; Takaoka, Masaki; Zhu, Fenfen; Oshita, Kazuyuki; Mizuno, Tadao; Morisawa, Shinsuke

    2010-01-01

    Over the past two decades, China has experienced rapid urbanization, which also leads to a lot of environmental problems including those of sewage sludge. As the amount of sewage sludge increases, conventional methods of treatment, such as compost and landfill, are facing the problems of limitations in demands or land. Considering that the demand of constructive materials in China keeps increasing, reusing municipal sewage sludge (MSS) in cement manufactory plant as fuels and raw materials is another practicable way to deal with it. The aim of this study is to describe the process of the heating of sewage sludge under different atmospheres of nitrogen and oxygen, and to find out some relation between the moisture of MSS and the heating time under different surrounding temperature by means of a mathematical model. In this study, we compared 4 kinds of MSS sampled in Beijing and Osaka. First of all, we defined the differences in those fundamental physical properties, such as concentration of various elements, calorific values and so on. Then the macroscopical thermal properties of the sludges were observed by means of thermogravimetric (TG) analysis. Both pyrolysis and combustion of 4 samples of MSS were studied by TG dynamic runs carried out at 10K/m. Visual observation of the heating profiles shows three stages in the heating process, which have been characterized. At last, we focused on batch processing drying tests using muffle furnace under temperature of 200, 250 and 300 degrees Celsius. The volatile matters loss besides moisture during heating process was evaluated and the experimental drying curves were matched with a mathematical model. (author)

  10. Processing of surrogate nuclear fuel pellets for better dimensional control with dry bag isostatic pressing

    Hoggan, Rita E., E-mail: Rita.hoggan@inl.gov; Zuck, Larry D., E-mail: Larry.zuck@inl.gov; Cannon, W. Roger, E-mail: cannon@rutgers.edu; Lessing, Paul A., E-mail: p.a.l.2@hotmail.com

    2016-12-15

    A study of improved methods of processing fuel pellets was undertaken using ceria and zirconia/yttria/alumina as surrogates. Through proper granulation, elimination of fines and vertical vibration (tapping) of the parts bag prior to dry bag isostatic pressing (DBIP), reproducibility of diameter profiles among multiple pellets of ceria was improved by almost an order of magnitude. Reproducibility of sintered pellets in these studies was sufficient to allow pellets to be introduced into the cladding with a gap between the pellet and cladding on the order of 50 μm to 100 μm but not a uniform gap with tolerance of ±12 μm as is currently required. Deviation from the mean diameter along the length of multiple pellets, and deviation from roundness, decreased after sintering. This is not generally observed with dry pressed pellets. Sintered shrinkage was uniform to ±0.05% and thus, as an alternative, pellets may be machined to tolerance before sintering, thus avoiding the waste associated with post-sinter grinding. - Highlights: • Three methods of granule preparation for two different powder sources were outlined and compared using tap density curves. • A dry bag isostatic press was used to fabricate pellets and longer rods. Thus longer pellets could be fabricated by this technique. • Vertical vibrations to pack granules decreased variation in dimensions from pellet to pellet by a factor of nine. • Sintering shrinkage varied by only 0.1% along the length of a rod. Thus green machining prior to sintering could result in tight tolerances.

  11. Non-isothermal processes during the drying of bare soil: Model Development and Validation

    Sleep, B.; Talebi, A.; O'Carrol, D. M.

    2017-12-01

    Several coupled liquid water, water vapor, and heat transfer models have been developed either to study non-isothermal processes in the subsurface immediately below the ground surface, or to predict the evaporative flux from the ground surface. Equilibrium phase change between water and gas phases is typically assumed in these models. Recently, a few studies have questioned this assumption and proposed a coupled model considering kinetic phase change. However, none of these models were validated against real field data. In this study, a non-isothermal coupled model incorporating kinetic phase change was developed and examined against the measured data from a green roof test module. The model also incorporated a new surface boundary condition for water vapor transport at the ground surface. The measured field data included soil moisture content and temperature at different depths up to the depth of 15 cm below the ground surface. Lysimeter data were collected to determine the evaporation rates. Short and long wave radiation, wind velocity, air ambient temperature and relative humidity were measured and used as model input. Field data were collected for a period of three months during the warm seasons in south eastern Canada. The model was calibrated using one drying period and then several other drying periods were simulated. In general, the model underestimated the evaporation rates in the early stage of the drying period, however, the cumulative evaporation was in good agreement with the field data. The model predicted the trends in temperature and moisture content at the different depths in the green roof module. The simulated temperature was lower than the measured temperature for most of the simulation time with the maximum difference of 5 ° C. The simulated moisture content changes had the same temporal trend as the lysimeter data for the events simulated.

  12. Management type affects composition and facilitative processes in altoandine dry grassland

    Catorci, Andrea; Cesaretti, Sabrina; Velasquez, Jose Luis; Burrascano, Sabina; Zeballos, Horacio

    2013-10-01

    We performed our study in the Dry Puna of the southern Peruvian Andes. Through a comparative approach we aimed to assess the effects of the two management systems, low grazing pressure by wild camelids vs. high grazing pressure by domestic livestock and periodic burning. Our general hypothesis was that the traditional high disturbance regime affects the dry Puna species diversity and composition through modifications of the magnitude of plant-plant-interactions and changes of the community structure due to shifts in species dominance. In 40 plots of 10 × 10 m, the cover value of each species was recorded and the species richness, floristic diversity, and community similarity of each treatment were compared. For each disturbance regime, differences of soil features (organic matter, carbon/nitrogen ratio, and potassium content) were tested. To evaluate plant-plant interactions, 4 linear transect divided into 500 plots of 10 × 10 cm were laid out and co-occurrence analysis was performed. We found that different disturbance regimes were associated with differences in the floristic composition, and that the high disturbance condition had lower species diversity and evenness. A decrease of tall species such as Festuca orthophylla and increase of dwarf and spiny Tetraglochin cristatum shrubs was observed as well. In addition, different disturbance intensities caused differences in the functional composition of the plant communities, since species with avoidance strategies are selected by high grazing pressure. High disturbance intensity was also associated to differences of soil features and to different clumped spatial structure of the dry Puna. Our results indicate also that: positive interactions are often species-specific mainly depending on the features of nurse and beneficiary species; the importance of positive interaction is higher at low grazing pressure than at high disturbance intensity; the magnitude and direction of the herbivory-mediated facilitation

  13. Preparation of polyaniline/sodium alanate hybrid using a spray-drying process

    Moreira, B. R., E-mail: bru-rms@yahoo.com.br, E-mail: fabiopassador@gmail.com, E-mail: pessan@ufscar.br; Passador, F. R., E-mail: bru-rms@yahoo.com.br, E-mail: fabiopassador@gmail.com, E-mail: pessan@ufscar.br; Pessan, L. A., E-mail: bru-rms@yahoo.com.br, E-mail: fabiopassador@gmail.com, E-mail: pessan@ufscar.br [Dep. de Engenharia de Materiais, Federal University of São Carlos (Brazil)

    2014-05-15

    Nowadays, hydrogen is highly interesting as an energy source, in particular in the automotive field. In fact, hydrogen is attractive as a fuel because it prevents air pollution and greenhouse emissions. One of the main problems with the utilization of hydrogen as a fuel is its on-board storage. The purpouse of this work was to develop a new hybrid material consisting of a polyaniline matrix with sodium alanate (NaAlH{sub 4}) using a spray-drying process. The polyaniline used for this experiment was synthesized by following a well-established method for the synthesis of the emeraldine base form of polyaniline using dodecylbenzenesulfonic acid as dopant. Micro particles of polyaniline/sodium alanate hybrids with 30 and 50 wt% of sodium alanate were prepared by using a spray-drying technique. Dilute solutions of polyaniline/sodium alanate were first prepared, 10g of the solid materials were mixed with 350 ml of toluene under stirring at room temperature for 24h and the solutions were dried using spray-dryer (Büchi, Switzerland) with 115°C of an inlet temperature. The hybrids were analyzed by differential scanning calorimetry, FT-IR and scanning electron microscopy (SEM). The addition of sodium alanate decreased the glass transition temperature of the hybrids when compared to neat polyaniline. FT-IR spectrum analysis was performed to identify the bonding environment of the synthesized material and was observed that simply physically mixture occurred between polyaniline and sodium alanate. The SEM images of the hybrids showed the formation of microspheres with sodium alanate dispersed in the polymer matrix.

  14. Rapid formation of phase-clean 110 K (Bi-2223) powders derived via freeze-drying process

    Balachandran, U.

    1996-06-04

    A process for the preparation of amorphous precursor powders for Pb-doped Bi{sub 2}Sr{sub 2} Ca{sub 2}Cu{sub 3}O{sub x} (2223) includes a freeze-drying process incorporating a splat-freezing step. The process generally includes splat freezing a nitrate solution of Bi, Pb, Sr, Ca, and Cu to form flakes of the solution without any phase separation; grinding the frozen flakes to form a powder; freeze-drying the frozen powder; heating the dried powder to form a dry green precursor powders; denitrating the green-powders; heating the denitrated powders to form phase-clean Bi-2223 powders. The grain boundaries of the 2223 grains appear to be clean, leading to good intergrain contact between 2223 grains. 11 figs.

  15. Exogenous iron redistribution between brain and spleen after the administration of the {sup 57}Fe{sub 3}O{sub 4} ferrofluid into the ventricle of the brain

    Gabbasov, Raul, E-mail: gabbasov_rr@nrcki.ru [National Research Centre “Kurchatov Institute”, Moscow (Russian Federation); Polikarpov, Dmitry [Department of Clinical Medicine, Faculty of Medicine and Health Science, Macquarie University, NSW (Australia); Cherepanov, Valery [National Research Centre “Kurchatov Institute”, Moscow (Russian Federation); Chuev, Michael; Mischenko, Ilya [Institute of Physics and Technology, Russian Academy of Sciences, Moscow (Russian Federation); Loginiva, Nadezhda; Loseva, Elena [Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow (Russian Federation); Nikitin, Maxim [Moscow Institute of Physics and Technology, Dolgoprudny (Russian Federation); Panchenko, Vladislav [National Research Centre “Kurchatov Institute”, Moscow (Russian Federation)

    2017-04-01

    Iron clearance pathways after the injection of {sup 57}Fe{sub 3}O{sub 4}-based dextran-stabilized ferrofluid into the brain ventricles were studied by Mössbauer spectroscopy and histologically. The nanoparticles appeared in spleen tissues within 3 h after transcranial injection. We separated and independently estimated concentrations of iron encapsulated in nanoparticles and iron encapsulated in proteins in the all rat organs. It was found that the dextran coated initial nanoparticles of the ferrofluid disintegrated in the brain into separate superparamagnetic nanoparticles within a week after the injection.The nanoparticles completely exited from the brain in a few weeks. The exogenous iron appeared in the spleen in 3 h after the injection and remained in the spleen for more than month. The appearance of additional component in Mössbauer spectra of spleen samples revealed a fundamental difference in the mechanisms of processing of iron nanoparticles in this organ, which was also confirmed by histological examination.

  16. Swarm motility inhibitory and antioxidant activities of pomegranate peel processed under three drying conditions.

    John, K M Maria; Bhagwat, Arvind A; Luthria, Devanand L

    2017-11-15

    During processing of ready-to-eat fresh fruits, large amounts of peel and seeds are discarded as waste. Pomegranate (Punicagranatum) peels contain high amounts of bioactive compounds which inhibit migration of Salmonella on wet surfaces. The metabolic distribution of bioactives in pomegranate peel, inner membrane, and edible aril portion was investigated under three different drying conditions along with the anti-swarming activity against Citrobacter rodentium. Based on the multivariate analysis, 29 metabolites discriminated the pomegranate peel, inner membrane, and edible aril portion, as well as the three different drying methods. Punicalagins (∼38.6-50.3mg/g) were detected in higher quantities in all fractions as compared to ellagic acid (∼0.1-3.2mg/g) and punicalins (∼0-2.4mg/g). The bioactivity (antioxidant, anti-swarming) and phenolics content was significantly higher in peels than the edible aril portion. Natural anti-swarming agents from food waste may have promising potential for controlling food borne pathogens. Published by Elsevier Ltd.

  17. Study of caprine bones after moist and dry heat processes by X-ray diffraction

    Barbosa, Caroline M.; Azeredo, Soraia R.; Lopes, Ricardo T.; Souza, Sheila M.F.M de

    2013-01-01

    Bone tissue is a biological material composed of hydroxyapatite (HAp) and collagen matrix. The bone X-ray diffraction (XRD) pattern presents characteristics of the hydroxyapatite crystallography planes. This paper presents the characterization by X-ray diffraction of caprine bone powder pattern and the comparison of this pattern with moist or dry heat cooked bone patterns. The parameters chosen to characterize the X-ray diffraction peaks were: angular position (2θ), full width at half maximumt (FWHM), and relative intensity (I rel ). The X-ray diffraction patterns were obtained with a Shimadzu XRD-6000 diffractometer. The caprine bone XRD pattern revealed a significant correlation of several crystallographic parameters (lattice data) with hydroxyapatite. The profiles of the three bone types analyzed presented differences. The study showed as small angular displacement (decrease of the 2θ angle) of some peaks was observed after moist and dry heat cooking processes. The characterization of bone tissue aimed to contribute to future analysis in the field of archeology. (author)

  18. Process of desulfurizing dephenolating, and cracking raw pitch obtained by dry distilling lignite, shale, etc

    1932-12-21

    A process is described of desulfurizing, dephenelating, and cracking the dry pitch obtained by dry distillation of lignite, bituminous shale, asphaltic rocks, and peat and fossil coals, that is characterized by the raw material being distilled in a retort together with calcium oxide, the vapors escaping from the still being compelled to pass through a catalyst tube containing calcium oxide mixed with other metallic oxide, the catalyst being helped by suitable heating to a temperature higher than that of the retort mentioned. For the purpose of lessening the quantity of phenolic groups contained in the raw tar to eliminate a great part of the sulfur belonging to the thiophenols and hydrogen sulfide without removing the organic radical to which they are attached, to accomplish a pyrogenic dissociation at the temperature of distillation of the pitch by means of using bone acid (phosphoric) to obtain a greater yield of light hydrocarbon from heavy hydrocarbons. Another purpose is the elimination of sulfur and thiophene and whatever neutral sulfur is contained in the primary pitch, by means of iron sulfate and copper in the anhydrous state or by means of other sulfates whose metals have the ability to form sulfides with sulfur.

  19. Study of caprine bones after moist and dry heat processes by X-ray diffraction

    Barbosa, Caroline M., E-mail: carolmattosb@yahoo.com.br [Instituto de Arqueologia Brasileira (IAB), Belford Roxo, RJ (Brazil); Azeredo, Soraia R.; Lopes, Ricardo T., E-mail: soraia@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/LIN/UFRJ), Rio de Janeiro, RJ (Brazil). Laboratorio de Instrumentacao Nuclear; Souza, Sheila M.F.M de, E-mail: sferraz@ensp.fiocruz.br [Fundacao Oswaldo Cruz (ENSP/FIOCRUZ), Rio de Janeiro, RJ (Brazil). Escola Nacional de Saude Publica Sergio Arouca

    2013-07-01

    Bone tissue is a biological material composed of hydroxyapatite (HAp) and collagen matrix. The bone X-ray diffraction (XRD) pattern presents characteristics of the hydroxyapatite crystallography planes. This paper presents the characterization by X-ray diffraction of caprine bone powder pattern and the comparison of this pattern with moist or dry heat cooked bone patterns. The parameters chosen to characterize the X-ray diffraction peaks were: angular position (2θ), full width at half maximumt (FWHM), and relative intensity (I{sub rel}). The X-ray diffraction patterns were obtained with a Shimadzu XRD-6000 diffractometer. The caprine bone XRD pattern revealed a significant correlation of several crystallographic parameters (lattice data) with hydroxyapatite. The profiles of the three bone types analyzed presented differences. The study showed as small angular displacement (decrease of the 2θ angle) of some peaks was observed after moist and dry heat cooking processes. The characterization of bone tissue aimed to contribute to future analysis in the field of archeology. (author)

  20. Spray Freeze-drying - The Process of Choice for Low Water Soluble Drugs?

    Leuenberger, H.

    2002-01-01

    Most of the novel highly potent drugs, developed on the basis of modern molecular medicine, taking into account cell surface recognition techniques, show poor water solubility. A chemical modification of the drug substance enhancing the solubility often decreases the pharmacological activity. Thus, as an alternative an increase of the solubility can be obtained by the reduction of the size of the drug particles. Unfortunately, it is often difficult to obtain micro or nanosized drug particles by classical or more advanced crystallization using supercritical gases or by milling techniques. In addition, nanosized particles are often not physically stable and need to be stabilized in an appropriate matrix. Thus, it may be of interest to manufacture directly nanosized drug particles stabilized in an inert hydrophilic matrix, i.e. nanostructured and nanocomposite systems. Solid solutions and solid dispersions represent nanostructured and nanocomposite systems. In this context, the use of the vacuum-fluidized-bed technique for the spray-drying of a low water soluble drug cosolubilized with a hydrophilic excipient in a polar organic solvent is discussed. In order to avoid the use of organic solvents, a special spray-freeze-drying technique working at atmospheric pressure is presented. This process is very suitable for temperature and otherwise sensitive drugs such as pharmaproteins

  1. Equipment and obtention process of 131I by dry distillation starting from TeO2

    Alanis M, J.

    2000-08-01

    The present invention refers to an equipment and process for the obtaining of 131 I by dry distillation starting from TeO 2 that has three interconnected systems, the manipulation system, the electric system and the distillation system, the combination of these systems, allows to improve the yield and the separation of the 131 I during the distillation process, since inside the electric system it is an oven that has a special design based on a temperature gradient. The more relevant aspects of the equipment its are the design of each one of its components that give as result the effectiveness of the production of 131 I in routinary form (industrial) whose final product can end up reaching a radiochemical purity up to 99% and a radionuclide purity of approximately 100%. The object of this invention is to provide a distillation equipment different to those that at the moment exist, thanks to its novel internal construction whose main characteristics already gather advantages on those existent. The reaction of obtaining of the TeO 2 , the development of the technique and studies of TeO 2 sintering and the irradiation experiments, its contributed to characterize with more precision the 'new process of obtaining of 131 I by dry via starting from the Te' developed in the ININ, and in this way it was achieved a more pure product, more economic, with less risks, from a point of view of Radiological Safety and mainly that it avoids the import to the country and it makes to self-sufficient Mexico in the production of 131 I. (Author)

  2. New Ultrasonic Controller and Characterization System for Low Temperature Drying Process Intensification

    Andrés, R. R.; Blanco, A.; Acosta, V. M.; Riera, E.; Martínez, I.; Pinto, A.

    Process intensification constitutes a high interesting and promising industrial area. It aims to modify conventional processes or develop new technologies in order to reduce energy needs, increase yields and improve product quality. It has been demonstrated by this research group (CSIC) that power ultrasound have a great potential in food drying processes. The effects associated with the application of power ultrasound can enhance heat and mass transfer and may constitute a way for process intensification. The objective of this work has been the design and development of a new ultrasonic system for the power characterization of piezoelectric plate-transducers, as excitation, monitoring, analysis, control and characterization of their nonlinear response. For this purpose, the system proposes a new, efficient and economic approach that separates the effect of different parameters of the process like excitation, medium and transducer parameters and variables (voltage, current, frequency, impedance, vibration velocity, acoustic pressure and temperature) by observing the electrical, mechanical, acoustical and thermal behavior, and controlling the vibrational state.

  3. NIR spectroscopy for the in-line monitoring of a multicomponent formulation during the entire freeze-drying process

    Rosas, Juan G; de Waard, Hans; De Beer, Thomas; Vervaet, Chris; Remon, Jean Paul; Hinrichs, Wouter L J; Frijlink, Henderik W; Blanco, Marcel

    2014-01-01

    Freeze drying is a complex, time consuming and thus expensive process, hence creating a need for understanding the material behaviour in the process environment and for process optimization. Near-infrared (NIR) spectroscopy offers the opportunity to monitor physicochemical changes of the formulation

  4. Thermomagnetic characterization of organic-based ferrofluids prepared with Ni ferrite nanoparticles

    Arana, Mercedes; Bercoff, Paula G.; Jacobo, Silvia E.

    2017-01-01

    Highlights: • Kerosene-based ferrofluids of Ni-ferrite NPs from high energy ball milling. • Thermomagnetic characterization of organic-based ferrofluids. • Measured thermal variables enhancements of ferrofluid vs. magnetic field. • Curves successfully fitted by a gas-compression model of nanoaggregates. - Abstract: In this work, a thermomagnetic characterization of kerosene-based ferrofluids (FFs) prepared with Ni-ferrite nanoparticles (NPs) is performed by measuring their thermal conductivity and diffusivity coefficient enhancements. The particles were synthesized by high-energy ball milling, as an alternative to the most commonly chosen NPs synthesis methods for FFs. The action of an applied magnetic field on the FF increases the thermal conductivity and diffusivity due to cooperation between the NPs, as it agglomerates them favoring chain-like and clusters formations. It was found that the heat capacity of the studied FFs decreases under the application of a magnetic field. The obtained results for thermal conductivity of FFs under magnetic fields were fitted by a gas-compression model that considers NPs agglomerates in the fluid.

  5. Implementation and automation of a Faraday experiment for the magneto-optical characterization of ferrofluids

    Velásquez, A A; Urquijo, J P

    2016-01-01

    This work presents the design, assembly and automation of a Faraday experiment for use in characterization of the magneto-optical response of fluids and ferrofluids. The magneto-optical Faraday experiment was automated using programmable equipment, controlled through the IEEE-488 port via Standard Commands for Programmable Instruments executed from a graphical interface developed in LabVIEW software. To calibrate the system the Verdet constants of distilled water and isopropyl alcohol were measured, obtaining an error percentage less than 2% for both fluids. Subsequently we used the system for measuring the Verdet constant of a ferrofluid of iron oxide nanoparticles diluted in distilled water, which was synthesized and, before its dilution, characterized by scanning electron microscopy, room temperature Mössbauer spectroscopy and vibrating sample magnetometry. We found that the Verdet constant of the diluted ferrofluid was smaller than that of distilled water, indicating opposite contributions of the effects of the diamagnetic and paramagnetic phases present in the ferrofluid to the magneto-optical effect. Details of the assembly, control of the experiment and development of the measurements are presented in this paper. (paper)

  6. Experimental verification of radial magnetic levitation force on the cylindrical magnets in ferrofluid dampers

    Yang, Wenming, E-mail: wenming_y@126.com [School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Wang, Pengkai [School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Hao, Ruican [School of Mechanical Engineering, Beijing Polytechnic, Beijing 100176 (China); Ma, Buchuan [Beijing Institute of Aerospace Control Devices, Beijing 100854 (China)

    2017-03-15

    Analytical and numerical calculation methods of the radial magnetic levitation force on the cylindrical magnets in cylindrical vessels filled with ferrofluid was reviewed. An experimental apparatus to measure this force was designed and tailored, which could measure the forces in a range of 0–2.0 N with an accuracy of 0.001 N. After calibrated, this apparatus was used to study the radial magnetic levitation force experimentally. The results showed that the numerical method overestimates this force, while the analytical ones underestimate it. The maximum deviation between the numerical results and the experimental ones was 18.5%, while that between the experimental results with the analytical ones attained 68.5%. The latter deviation narrowed with the lengthening of the magnets. With the aids of the experimental verification of the radial magnetic levitation force, the effect of eccentric distance of magnets on the viscous energy dissipation in ferrofluid dampers could be assessed. It was shown that ignorance of the eccentricity of magnets during the estimation could overestimate the viscous dissipation in ferrofluid dampers. - Highlights: • Experimental method measuring magnetic levitation force of ferrofluid was studied. • A simple but rather witty apparatus was designed and tailored. • The apparatus can measure forces in a range of 0–2.0 N with an accuracy of 0.001 N. • Existing methods calculating magnetic levitation force were verified experimentally.

  7. Experimental verification of radial magnetic levitation force on the cylindrical magnets in ferrofluid dampers

    Yang, Wenming; Wang, Pengkai; Hao, Ruican; Ma, Buchuan

    2017-01-01

    Analytical and numerical calculation methods of the radial magnetic levitation force on the cylindrical magnets in cylindrical vessels filled with ferrofluid was reviewed. An experimental apparatus to measure this force was designed and tailored, which could measure the forces in a range of 0–2.0 N with an accuracy of 0.001 N. After calibrated, this apparatus was used to study the radial magnetic levitation force experimentally. The results showed that the numerical method overestimates this force, while the analytical ones underestimate it. The maximum deviation between the numerical results and the experimental ones was 18.5%, while that between the experimental results with the analytical ones attained 68.5%. The latter deviation narrowed with the lengthening of the magnets. With the aids of the experimental verification of the radial magnetic levitation force, the effect of eccentric distance of magnets on the viscous energy dissipation in ferrofluid dampers could be assessed. It was shown that ignorance of the eccentricity of magnets during the estimation could overestimate the viscous dissipation in ferrofluid dampers. - Highlights: • Experimental method measuring magnetic levitation force of ferrofluid was studied. • A simple but rather witty apparatus was designed and tailored. • The apparatus can measure forces in a range of 0–2.0 N with an accuracy of 0.001 N. • Existing methods calculating magnetic levitation force were verified experimentally.

  8. Investigation of Oriented Magnetic Field Effects on Entropy Generation in an Inclined Channel Filled with Ferrofluids

    Elgiz Baskaya

    2017-07-01

    Full Text Available Dispersion of super-paramagnetic nanoparticles in nonmagnetic carrier fluids, known as ferrofluids, offers the advantages of tunable thermo-physical properties and eliminate the need for moving parts to induce flow. This study investigates ferrofluid flow characteristics in an inclined channel under inclined magnetic field and constant pressure gradient. The ferrofluid considered in this work is comprised of Cu particles as the nanoparticles and water as the base fluid. The governing differential equations including viscous dissipation are non-dimensionalised and discretized with Generalized Differential Quadrature Method. The resulting algebraic set of equations are solved via Newton-Raphson Method. The work done here contributes to the literature by searching the effects of magnetic field angle and channel inclination separately on the entropy generation of the ferrofluid filled inclined channel system in order to achieve best design parameter values so called entropy generation minimization is implemented. Furthermore, the effect of magnetic field, inclination angle of the channel and volume fraction of nanoparticles on velocity and temperature profiles are examined and represented by figures to give a thorough understanding of the system behavior.

  9. Thermomagnetic characterization of organic-based ferrofluids prepared with Ni ferrite nanoparticles

    Arana, Mercedes, E-mail: mercedes.arana@labh2.coppe.ufrj.br [Facultad de Matemática, Astronomía, Física y Computación (FaMAF), Universidad Nacional de Córdoba, IFEG, CONICET, Medina Allende s/n, Ciudad Universitaria, Córdoba (Argentina); Bercoff, Paula G. [Facultad de Matemática, Astronomía, Física y Computación (FaMAF), Universidad Nacional de Córdoba, IFEG, CONICET, Medina Allende s/n, Ciudad Universitaria, Córdoba (Argentina); Jacobo, Silvia E. [DiQuiMMAI, Facultad de Ingeniería, Universidad de Buenos Aires, INTECIN, CONICET, Av. Paseo Colón 850, Buenos Aires (Argentina)

    2017-01-15

    Highlights: • Kerosene-based ferrofluids of Ni-ferrite NPs from high energy ball milling. • Thermomagnetic characterization of organic-based ferrofluids. • Measured thermal variables enhancements of ferrofluid vs. magnetic field. • Curves successfully fitted by a gas-compression model of nanoaggregates. - Abstract: In this work, a thermomagnetic characterization of kerosene-based ferrofluids (FFs) prepared with Ni-ferrite nanoparticles (NPs) is performed by measuring their thermal conductivity and diffusivity coefficient enhancements. The particles were synthesized by high-energy ball milling, as an alternative to the most commonly chosen NPs synthesis methods for FFs. The action of an applied magnetic field on the FF increases the thermal conductivity and diffusivity due to cooperation between the NPs, as it agglomerates them favoring chain-like and clusters formations. It was found that the heat capacity of the studied FFs decreases under the application of a magnetic field. The obtained results for thermal conductivity of FFs under magnetic fields were fitted by a gas-compression model that considers NPs agglomerates in the fluid.

  10. The influence of sun drying process and prolonged storage on composition of essential oil from clove buds (Syzygium aromaticum)

    Hastuti, L. T.; Saepudin, E.; Cahyana, A. H.; Rahayu, D. U. C.; Murni, V. W.; Haib, J.

    2017-07-01

    Clove (Syzygium aromaticum) is native to Indonesia and used as a spice in virtually all of the world's cuisine. Clove bud oil, a yellow liquid, is obtained from distillation of buds. The quality of oil is influenced by origin, post-harvest processing, pre-treatment before distillation, the distillation method, and post-distillation treatment. The objective of this study is to investigate the effect of drying process and prolonged storage on essential oil composition of clove bud from the Tolitoli, Indonesia. To determine the effect of drying, fresh clove bud was dried under sunlight until it reached moisture content 13±1 %. The effect of storage was studied in the oil extracted from clove bud that was stored in laboratory at 25 °C for 4 months. The essential oil of each treatment was obtained by steam distillation and its chemical composition was analyzed by GC/MS. The major components found in fresh and dried clove are as follows: eugenol, eugenyl acetate, and caryophyllene. Percentage of caryophyllene was slightly increase after drying but decrease during storage. While the content of eugenyl acetate decreased during drying and storage, the content of eugenol increased. The drying and storage also affect to the change on minor compounds of essential oil of clove.

  11. Change of the structure and the digestibility of myofibrillar proteins in Nanjing dry-cured duck during processing.

    Du, Xiaojing; Sun, Yangying; Pan, Daodong; Wang, Ying; Ou, Changrong; Cao, Jinxuan

    2018-06-01

    To investigate the change of bioavailability and structure of myofibrillar proteins during Nanjing dry-cured duck processing, carbonyl content, sulfhydryl (SH) group, disulfide (SS) group, sodium dodecyl sulfate polyacrylamide gel electrophoresis, surface hydrophobicity, secondary structures and in vitro digestibility were determined. During processing, carbonyl content and surface hydrophobicity increased; SH turned into SS group; α-helix turned into β-sheet and random coil fractions. Protein degradation occurred during dry-curing and drying-ripening stages. The in vitro digestibility of pepsin and pancreatic proteases increased during the salt curing stage and decreased during the drying-ripening stage. The increase of digestibility could be attributed to the mild oxidation, degradation and unfolding of proteins while the decrease of digestibility was related to the intensive oxidation and aggregation of proteins. Protein degradation was not a main factor of digestibility during the drying-ripening stage. Results demonstrated that the bioavailability loss of myofibrillar proteins in Nanjing dry-cured duck occurred during the stage of drying-ripening instead of curing. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Hybrid response surface methodology-artificial neural network optimization of drying process of banana slices in a forced convective dryer.

    Taheri-Garavand, Amin; Karimi, Fatemeh; Karimi, Mahmoud; Lotfi, Valiullah; Khoobbakht, Golmohammad

    2018-06-01

    The aim of the study is to fit models for predicting surfaces using the response surface methodology and the artificial neural network to optimize for obtaining the maximum acceptability using desirability functions methodology in a hot air drying process of banana slices. The drying air temperature, air velocity, and drying time were chosen as independent factors and moisture content, drying rate, energy efficiency, and exergy efficiency were dependent variables or responses in the mentioned drying process. A rotatable central composite design as an adequate method was used to develop models for the responses in the response surface methodology. Moreover, isoresponse contour plots were useful to predict the results by performing only a limited set of experiments. The optimum operating conditions obtained from the artificial neural network models were moisture content 0.14 g/g, drying rate 1.03 g water/g h, energy efficiency 0.61, and exergy efficiency 0.91, when the air temperature, air velocity, and drying time values were equal to -0.42 (74.2 ℃), 1.00 (1.50 m/s), and -0.17 (2.50 h) in the coded units, respectively.

  13. Development of Improved Process with Treatment of Cellulase for Isolation of Ampelopsin from Dried Fruits of Ampelopsis grossedentata

    Wa Gao

    2016-02-01

    Full Text Available The commercial method for isolation of ampelopsin, one of the most common flavonoids isolated from the plant species Ampelopsis grossedentata, is a simple hydrothermal extraction at high temperature. To develop an improved process to isolate ampelopsin, the effects of treatment of cellulase on hydrolysis of the dried fruit of A. grossedentata were investigated. The treatment of cellulase was found to decrease the temperature and time for hydrolysis of the dried fruit of A. grossedentata. The conditions of the filter press and continuous flow centrifuge for removal of insoluble materials from the hydrolysate of the dried fruit of A. grossedentata were optimized. The recovery yield of ampelopsin from the dried fruits of A. grossedentata was 39.4%, as determined by HPLC chromatographic analysis. A safe and economical process at low temperature with treatment of cellulase for the isolation of ampelopsin was developed in this study.

  14. Effect of steam thermal treatment on the drying process of Eucalyptus dunnii variables

    Elias Taylor Durgante Severo

    2013-12-01

    Full Text Available The aim of this study was to evaluate the effect of steam treatment prior to drying on the initial moisture content, moisture gradient, and drying rate in Eucalyptus dunnii Maiden wood. Boards were steamed at 100ºC for 3 h after 1 h of heating-up. Part of these boards was dried in a drying electric oven at 50ºC, and part was dried at kiln. The results showed that the steaming prior to drying of wood: (1 significantly reduced by 9.2% the initial moisture content; (2 significantly increased by 6.2% the drying rate; (3 significantly decreased by 15.6 and 14.8% the moisture gradient between the outer layer and the center of boards and between the outer and intermediate layers of boards, respectively. Steamed boards when dried in an oven showed drying rate of 0.007065 whereas in kiln were 0.008200 and 0.034300 from green to 17 and 17 to 12% moisture content, respectively. It was demonstrated that the steaming prior to drying can be suitable for reduces the drying times of this kind of wood.

  15. Hepatoprotective Activity of Dried- and Fermented-Processed Virgin Coconut Oil

    Z. A. Zakaria

    2011-01-01

    Full Text Available The present study aims to determine the hepatoprotective effect of MARDI-produced virgin coconut oils, prepared by dried- or fermented-processed methods, using the paracetamol-induced liver damage in rats. Liver injury induced by 3 g/kg paracetamol increased the liver weight per 100 g bodyweight indicating liver damage. Histological observation also confirms liver damage indicated by the presence of inflammations and necrosis on the respective liver section. Interestingly, pretreatment of the rats with 10, but not 1 and 5, mL/kg of both VCOs significantly (P<.05 reduced the liver damage caused by the administration of paracetamol, which is further confirmed by the histological findings. In conclusion, VCO possessed hepatoprotective effect that requires further in-depth study.

  16. Implementation of a dry process fuel cycle model into the DYMOND code

    Park, Joo Hwan; Jeong, Chang Joon; Choi, Hang Bok

    2004-01-01

    For the analysis of a dry process fuel cycle, new modules were implemented into the fuel cycle analysis code DYMOND, which was developed by the Argonne National Laboratory. The modifications were made to the energy demand prediction model, a Canada Deuterium Uranium (CANDU) reactor, direct use of spent Pressurized Water Reactor (PWR) fuel in CANDU reactors (DUPIC) fuel cycle model, the fuel cycle calculation module, and the input/output modules. The performance of the modified DYMOND code was assessed for the postulated once-through fuel cycle models including both the PWR and CANDU reactor. This paper presents modifications of the DYMOND code and the results of sample calculations for the PWR once-through and DUPIC fuel cycles

  17. Effect of Fluidized Bed Stirring on Drying Process of Adhesive Particles

    P. Hoffman

    2017-04-01

    Full Text Available This paper presents an attempt to optimize fluidized bed drying of wet and adhesive particles (with an initial diameter of about 580 mm with the use of stirring, and discusses the influence of stirring on the total drying time. The goal was to demonstrate the positive effect of stirring a fluidized bed to the drying time, to find the optimal parameters (stirrer design, speed, and size. Experiments were conducted on a drying chamber in batch operation. The objective was to evaluate the effect of stirring on the total drying time. The drying chambers were 85 mm, 100 mm, and 140 mm in diameter. An optimal stirrer shape and speed were specified. Our arrangement of the fluidized bed resulted in a decrease in drying time by up to 40 %.

  18. Tools for studying dry-cured ham processing by using computed tomography.

    Santos-Garcés, Eva; Muñoz, Israel; Gou, Pere; Sala, Xavier; Fulladosa, Elena

    2012-01-11

    An accurate knowledge and optimization of dry-cured ham elaboration processes could help to reduce operating costs and maximize product quality. The development of nondestructive tools to characterize chemical parameters such as salt and water contents and a(w) during processing is of special interest. In this paper, predictive models for salt content (R(2) = 0.960 and RMSECV = 0.393), water content (R(2) = 0.912 and RMSECV = 1.751), and a(w) (R(2) = 0.906 and RMSECV = 0.008), which comprise the whole elaboration process, were developed. These predictive models were used to develop analytical tools such as distribution diagrams, line profiles, and regions of interest (ROIs) from the acquired computed tomography (CT) scans. These CT analytical tools provided quantitative information on salt, water, and a(w) in terms of content but also distribution throughout the process. The information obtained was applied to two industrial case studies. The main drawback of the predictive models and CT analytical tools is the disturbance that fat produces in water content and a(w) predictions.

  19. Coal preparation and coal cleaning in the dry process; Kanshiki sentaku to coal cleaning

    Tanaka, Z; Morikawa, M; Fujii, Y [Okayama University, Okayama (Japan). Faculty of Engineering

    1996-09-01

    Because the wet process has a problem such as waste water treatment, coal cleaning in the dry process was discussed. When a fluidized bed (using glass beads and calcium carbonate) is utilized instead of the heavy liquid, the fluidized bed will have apparent density as the liquid does, whereas the relative relationship therewith determines whether a substance having been put into the fluidized bed will float or sink. This is utilized for coals. In addition, two powder constituents of A and B may be wanted to be separated using the fluidized extraction process (similar to the liquid-liquid extraction process). In such a case, a fluidized bed in which both constituents are mixed is added with a third constituent C (which will not mix with A, but mix well with B), where the constituents are separated into A and (B + C), and the (B + C) constituent is separated further by using a sieve. If coal has the coal content mixed with ash content and pulverized, it turns into particle groups which have distributions in grain size and density. Groups having higher density may contain more ash, and those having lower density less ash. In addition, the ash content depends also on the grain size. The ash content may be classified by using simultaneously wind classification (for density and grain size) and a sieve (for grain size). This inference may be expanded to consideration of constructing a multi-stage fluidized bed classification tower. 12 figs., 5 tabs.

  20. Surface modification of magnesium hydroxide sulfate hydrate whiskers using a silane coupling agent by dry process

    Zhu, Donghai; Nai, Xueying; Lan, Shengjie; Bian, Shaoju; Liu, Xin; Li, Wu

    2016-01-01

    Highlights: • Dry process was adopted to modify the surface of MHSH whiskers using silane. • Si−O−Mg bonds were formed directly by the reaction between Si−OC 2 H 5 and −OH of MHSH. • Dispersibility and compatibility of modified whiskers greatly improved in organic phase. • Thermal stability of whiskers was enhanced after modified. - Abstract: In order to improve the compatibility of magnesium hydroxide sulfate hydrate (MHSH) whiskers with polymers, the surface of MHSH whiskers was modified using vinyltriethoxysilane (VTES) by dry process. The possible mechanism of the surface modification and the interfacial interactions between MHSH whiskers and VTES, as well as the effect of surface modification, were studied. Scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and X-ray powder diffraction (XRD) analyses showed that the agglomerations were effectively separated and a thin layer was formed on the surface of the whiskers after modification. Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses showed that the VTES molecules were bound to the surface of MHSH whiskers after modification. Chemical bonds (Si−O−Mg) were formed by the reaction between Si−OC 2 H 5 or Si−OH and the hydroxyl group of MHSH whiskers. The effect of surface modification was evaluated by sedimentation tests, contact angle measurements and thermogravimetric analysis (TGA). The results showed that the surface of MHSH whiskers was transformed from hydrophilic to hydrophobic, and the dispersibility and the compatibility of MHSH whiskers were significantly improved in the organic phase. Additionally, the thermal stability of the VTES-modified MHSH whiskers was improved significantly.

  1. Microstructure and textural and viscoelastic properties of model processed cheese with different dry matter and fat in dry matter content

    Černíková, M.; Nebesářová, Jana; Salek, R. N.; Řiháčková, L.; Buňka, F.

    2017-01-01

    Roč. 100, č. 6 (2017), s. 4300-4307 ISSN 0022-0302 R&D Projects: GA MŠk(CZ) LM2015062 Institutional support: RVO:60077344 Keywords : processed cheese * texture * rheology * scanning electron microscopy Subject RIV: FS - Medical Facilities ; Equipment OBOR OECD: 2.11 Other engineering and technologies Impact factor: 2.474, year: 2016

  2. Design of experiment characterization of microneedle fabrication processes based on dry silicon etching

    Held, J.; Gaspar, J.; Ruther, P.; Hagner, M.; Cismak, A.; Heilmann, A.; Paul, O.

    2010-02-01

    This paper reports on the characterization of dry etching-based processes for the fabrication of silicon microneedles using a design of experiment (DoE) approach. The possibility of using such microneedles as protruding microelectrodes able to electroporate adherently growing cells and record intracellular potentials motivates the systematic analysis of the influence of etching parameters on the needle shape. Two processes are characterized: a fully isotropic etch process and a three-step etching approach. In the first case, the shape of the microneedles is defined by a single etch step. For the stepped method, the structures are realized using the following sequence: a first, isotropic step defines the tip; this is followed by anisotropic etching that increases the height of the needle; a final isotropic procedure thins the microneedle and sharpens its tip. From the various process parameters tested, it is concluded that the isotropic fabrication is influenced mostly by four process parameters, whereas six parameters dominantly govern the outcome of the stepped etching technique. The dependence of the needle shape on the etch mask diameter is also investigated. Microneedles with diameters down to the sub-micrometer range and heights below 10 µm are obtained. The experimental design is performed using the D-optimal method. The resulting geometry, i.e. heights, diameters and radii of curvature measured at different positions, is extracted from scanning electron micrographs of needle cross-sections obtained from cuts by focused ion beam. The process parameters are used as inputs and the geometry features of the microneedles as outputs for the analysis of the process.

  3. Design of experiment characterization of microneedle fabrication processes based on dry silicon etching

    Held, J; Gaspar, J; Ruther, P; Paul, O; Hagner, M; Cismak, A; Heilmann, A

    2010-01-01

    This paper reports on the characterization of dry etching-based processes for the fabrication of silicon microneedles using a design of experiment (DoE) approach. The possibility of using such microneedles as protruding microelectrodes able to electroporate adherently growing cells and record intracellular potentials motivates the systematic analysis of the influence of etching parameters on the needle shape. Two processes are characterized: a fully isotropic etch process and a three-step etching approach. In the first case, the shape of the microneedles is defined by a single etch step. For the stepped method, the structures are realized using the following sequence: a first, isotropic step defines the tip; this is followed by anisotropic etching that increases the height of the needle; a final isotropic procedure thins the microneedle and sharpens its tip. From the various process parameters tested, it is concluded that the isotropic fabrication is influenced mostly by four process parameters, whereas six parameters dominantly govern the outcome of the stepped etching technique. The dependence of the needle shape on the etch mask diameter is also investigated. Microneedles with diameters down to the sub-micrometer range and heights below 10 µm are obtained. The experimental design is performed using the D-optimal method. The resulting geometry, i.e. heights, diameters and radii of curvature measured at different positions, is extracted from scanning electron micrographs of needle cross-sections obtained from cuts by focused ion beam. The process parameters are used as inputs and the geometry features of the microneedles as outputs for the analysis of the process.

  4. Processing of Polysulfone to Free Flowing Powder by Mechanical Milling and Spray Drying Techniques for Use in Selective Laser Sintering

    Nicolas Mys

    2016-04-01

    Full Text Available Polysulfone (PSU has been processed into powder form by ball milling, rotor milling, and spray drying technique in an attempt to produce new materials for Selective Laser Sintering purposes. Both rotor milling and spray drying were adept to make spherical particles that can be used for this aim. Processing PSU pellets by rotor milling in a three-step process resulted in particles of 51.8 μm mean diameter, whereas spray drying could only manage a mean diameter of 26.1 μm. The resulting powders were characterized using Differential Scanning Calorimetry (DSC, Gel Permeation Chromatography (GPC and X-ray Diffraction measurements (XRD. DSC measurements revealed an influence of all processing techniques on the thermal behavior of the material. Glass transitions remained unaffected by spray drying and rotor milling, yet a clear shift was observed for ball milling, along with a large endothermic peak in the high temperature region. This was ascribed to the imparting of an orientation into the polymer chains due to the processing method and was confirmed by XRD measurements. Of all processed powder samples, the ball milled sample was unable to dissolve for GPC measurements, suggesting degradation by chain scission and subsequent crosslinking. Spray drying and rotor milling did not cause significant degradation.

  5. Synthesis of ferrofluid based nanoarchitectured polypyrrole composites and its application for electromagnetic shielding

    Varshney, Swati [Polymeric and Soft Materials Section, National Physical Laboratory (CSIR), New Delhi 110012 (India); Department of Chemistry, Delhi Institute of Tool Engineering, Okhla, New Delhi 110020 (India); Amity Institute of Advanced Research and Studies, Materials and Devices, AIARS (M and D), Amity University, Noida, UP 201303 (India); Ohlan, Anil [Department of Physics, M.D. University, Rohtak, Haryana 124001 (India); Jain, V.K. [Amity Institute of Advanced Research and Studies, Materials and Devices, AIARS (M and D), Amity University, Noida, UP 201303 (India); Dutta, V.P. [Department of Chemistry, Delhi Institute of Tool Engineering, Okhla, New Delhi 110020 (India); Dhawan, S.K., E-mail: skdhawan@mail.nplindia.ernet.in [Polymeric and Soft Materials Section, National Physical Laboratory (CSIR), New Delhi 110012 (India)

    2014-01-15

    The monodispersion of magnetic nanoparticles in conducting polymer is the prerequisite to make a high quality composite for tunable electromagnetic interference (EMI) shielding. To meet this challenge, we have designed and synthesized ferrofluid based nanoarchitectured polypyrrole composites containing Fe{sub 3}O{sub 4} (8–12 nm) via in situ oxidative polymerization. To tune the microwave signals, polypyrrole composites (PFF) with different monomer/ferrofluid weight ratios have been prepared and characterized in microwave frequency domain. A maximum shielding effectiveness value of SE{sub A(max)} = 20.4 dB (∼99% attenuation) due to the absorption of microwave has been observed in the frequency range of 12.4–18 GHz and attenuation level varied with ferrofluid loading. The electrical conductivity of PFF composite is of the order of 10{sup −2} S cm{sup −1} order and having superparamagnetic nature with saturation magnetization (M{sub s}) of 5.5 emu g{sup −1}. The lightweight PFF composites with high attenuations can provide full control over the atomic structure and are favorable for the practical EMI shielding application for commercial electronic appliances. - Highlights: • Aqueous ferrofluid has been incorporated in polypyrrole matrix leads to PFF nanocomposites. • PFF composites shows conductivity of the order of 10{sup −2} S cm{sup −1} and saturation magnetization of 5.5 emu g{sup −1}. • Shielding effectiveness of 23.5 dB (SE{sub A} ∼ 20.4 dB and SE{sub R} ∼ 3.1 dB) has been achieved. • Shielding effectiveness depends on the ferrofluid loading.

  6. Optimization of the Büchi B-90 spray drying process using central composite design for preparation of solid dispersions.

    Gu, Bing; Linehan, Brian; Tseng, Yin-Chao

    2015-08-01

    A central composite design approach was applied to study the effect of polymer concentration, inlet temperature and air flow rate on the spray drying process of the Büchi B-90 nano spray dryer (B-90). Hypromellose acetate succinate-LF was used for the Design of Experiment (DoE) study. Statistically significant models to predict the yield, spray rate, and drying efficiency were generated from the study. The spray drying conditions were optimized according to the models to maximize the yield and efficiency of the process. The models were further validated using a poorly water-soluble investigational compound (BI064) from Boehringer Ingelheim Pharmaceuticals. The polymer/drug ratio ranged from 1/1 to 3/1w/w. The spray dried formulations were amorphous determined by differential scanning calorimetry and X-ray powder diffraction. The particle size of the spray dried formulations was 2-10 μm under polarized light microscopy. All the formulations were physically stable for at least 3h when suspended in an aqueous vehicle composed of 1% methyl cellulose. This study demonstrates that DoE is a useful tool to optimize the spray drying process, and the B-90 can be used to efficiently produce amorphous solid dispersions with a limited quantity of drug substance available during drug discovery stages. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Aeolian process of the dried-up riverbeds of the Hexi Corridor, China: a wind tunnel experiment.

    Zhang, Caixia; Wang, Xunming; Dong, Zhibao; Hua, Ting

    2017-08-01

    Wind tunnel studies, which remain limited, are an important tool to understand the aeolian processes of dried-up riverbeds. The particle size, chemical composition, and the mineral contents of sediments arising from the dried river beds are poorly understood. Dried-up riverbeds cover a wide area in the Hexi Corridor, China, and comprise a complex synthesis of different land surfaces, including aeolian deposits, pavement surfaces, and Takyr crust. The results of the present wind tunnel experiment suggest that aeolian transport from the dried-up riverbeds of the Hexi Corridor ranges from 0 to 177.04 g/m 2 /min and that dry riverbeds could be one of the main sources of dust emissions in this region. As soon as the wind velocity reaches 16 m/s and assuming that there are abundant source materials available, aeolian transport intensity increases rapidly. The dried-up riverbed sediment and the associated aeolian transported material were composed mainly of fine and medium sands. However, the transported samples were coarser than the bed samples, because of the sorting effect of the aeolian processes on the sediment. The aeolian processes also led to regional elemental migration and mineral composition variations.

  8. Enhanced bio-compatibility of ferrofluids of self-assembled superparamagnetic iron oxide-silica core-shell nanoparticles

    Narayanan, T.N.; Mary, A.P.R.; Swalih, P.K.A.; Kumar, D.S.; Makarov, D.; Albrecht, M.; Puthumana, J.; Anas, A.; Anantharaman, A.

    -interacting, monodispersed and hence the synthesis of such nanostructures has great relevance in the realm of nanoscience. Silica-coated superparamagnetic iron oxide nanoparticles based ferrofluids were prepared using polyethylene glycol as carrier fluid by employing a...

  9. Non-regularized inversion method from light scattering applied to ferrofluid magnetization curves for magnetic size distribution analysis

    Rijssel, Jos van; Kuipers, Bonny W.M.; Erné, Ben H.

    2014-01-01

    A numerical inversion method known from the analysis of light scattering by colloidal dispersions is now applied to magnetization curves of ferrofluids. The distribution of magnetic particle sizes or dipole moments is determined without assuming that the distribution is unimodal or of a particular shape. The inversion method enforces positive number densities via a non-negative least squares procedure. It is tested successfully on experimental and simulated data for ferrofluid samples with known multimodal size distributions. The created computer program MINORIM is made available on the web. - Highlights: • A method from light scattering is applied to analyze ferrofluid magnetization curves. • A magnetic size distribution is obtained without prior assumption of its shape. • The method is tested successfully on ferrofluids with a known size distribution. • The practical limits of the method are explored with simulated data including noise. • This method is implemented in the program MINORIM, freely available online

  10. Investigating the Plasma-Assisted and Thermal Catalytic Dry Methane Reforming for Syngas Production: Process Design, Simulation and Evaluation

    Evangelos Delikonstantis

    2017-09-01

    Full Text Available The growing surplus of green electricity generated by renewable energy technologies has fueled research towards chemical industry electrification. By adapting power-to-chemical concepts, such as plasma-assisted processes, cheap resources could be converted into fuels and base chemicals. However, the feasibility of those electrified processes at large scale has not been investigated yet. Thus, the current work strives to compare, for first time in the literature, plasma-assisted production of syngas, from CH4 and CO2 (dry methane reforming, with thermal catalytic dry methane reforming. Specifically, both processes are conceptually designed to deliver syngas suitable for methanol synthesis (H2/CO ≥ 2 in mole. The processes are simulated in the Aspen Plus process simulator where different process steps are investigated. Heat integration and equipment cost estimation are performed for the most promising process flow diagrams. Collectively, plasma-assisted dry methane reforming integrated with combined steam/CO2 methane reforming is an effective way to deliver syngas for methanol production. It is more sustainable than combined thermal catalytic dry methane reforming with steam methane reforming, which has also been proposed for syngas production of H2/CO ≥ 2; in the former process, 40% more CO2 is captured, while 38% less H2O is consumed per mol of syngas. Furthermore, the plasma-assisted process is less complex than the thermal catalytic one; it requires higher amount of utilities, but comparable capital investment.

  11. ENVIRONMENTAL AFTERMATH FROM THE DRYING PROCESSES OF AL-HUWAIZA MARSHLAND, IRAQ

    Khafaja Ahmed Mays SADKHAN

    2017-01-01

    Full Text Available Al-Huwaiza marsh shows environmental and economic significance, but it has been exposed to the drying processes and then to the drowning processes. It has witnessed great decrease in the water resources specified for the country and the decrease in the water portion feeding it. A fact which shows negative effects on its area, for the change of the environmental variables, has affected the process of nurturing the marsh - only 33.4% of the area of the marsh has been drowned during the 1990s. As a result, its environmental features have been deteriorated, which have negatively affected the kind of water contained in it and which require a series of procedures and solutions to be done in this regard. Among these there are the following: encouraging the dialogue and negotiations with the countries in which the high basins of the rivers Tigris and Euphrates are located (Turkey, Syria and Iran, controlling the random spread of the marshes and concentrating on the constant and deep marshes, developing and rehabilitating the deep marshes by means of establishing natural protected areas, enlivening the constant marshes by means of connecting them to one another, supporting and encouraging studies and research, controlling the pollution of the marshes, developing the general services of the marsh areas and the neighboring ones, and stronger involving of the ministries which should pay their serious and actual attention to the environment and the population of the marshes.

  12. Evaluation of the processing of dry biological ferment for gamma radiation

    Sabundjian, Ingrid Traete

    2007-01-01

    The developed work had with objectives to demonstrate if it had alteration in the growth of UFC in plate and in the viability of yeasts and total bacteria when dry biological ferment was dealt with by different doses to gamma radiation and under different times storage, to determine the D10 dose for total bacteria and yeasts in this product and to analyzed the processing of this product it promoted some benefit without causing unfeasibility of exactly. The different samples of dry biological ferment had been irradiated at IPEN in a Gammacell - 220 source at 0.5; 1; 2 and 3 kGy doses (dose rate of 3.51 kGy/h). This procedure referring samples to each dose of radiation had been after destined to the microbiological analysis and the test of viability while excessively the samples had been stored the ambient temperature (23 degree C). The increase of the dose of radiation caused a reduction in the counting of yeasts growth, of total bacteria growth and also in the frequency of viable yeast cells, demonstrated by FDA-EB fluorescent method. Beyond of radiation the storage time also it influenced in counting reduction of total bacteria and reduction of frequency of viable cells. According with the analysis of simple linear regression, the dose of radiation necessary to eliminate 90% of the yeast population was between 1.10 and 2.23 kGy and for the bacterial population varied between 2.31 and 2.95 kGy. These results demonstrated clearly the negative points of the application of ionizing radiation in dry biological ferment; therefore the interval of D10 found for total bacteria is superior to found for yeasts. Being thus, the use of this resource for the improvement of the product quality becomes impracticable, since to reduce significantly the bacterial population necessarily we have that to diminish the population of yeasts. With yeasts reduction of we will go significantly to modify the quality and the viability of product. (author)

  13. Better lumber drying process with a non-greenhouse type solar kiln

    Yang, K C

    1979-01-01

    The preliminary study of using solar energy for lumber drying in NW Ontario is proven applicable and practical by the evidence of data collected. It was found that lumber seasoning using solar energy in the region is more favorable in the summer than in the winter. The most significant advantages of lumber drying with a solar kiln are: (1) low percentage of drying defect lumber produced; (2) higher strength properties of lumber produced; (3) unlimited sources of heat energy from the sun are available. The longer drying periods with a solar kiln as compared to a conventional steam kiln can be overcome by utilizing a supplemental heat system, e.g., wood residue burner to shorten the drying period. However, some improvements and modification of the existing kiln should be done in order to increase the efficiency of the lumber drying system.

  14. Electron-beam and combined e-b and microwave processing of dried food ingredients

    Ferdes, O.; Minea, R.; Martin, D.; Tirlea, A.; Badea, M.; Oproiu, C.

    1998-01-01

    Complete text of publication follows. There are summarized and presented the results on the irradiated dried food ingredients, as starches, flour, spices, enzymes, pigments. It has investigated the electron-beam and microwave processing to achieve the hygienic and microbiological quality requirements for these materials. There are presented the results regarding the e-b and microwave effects on the main specific parameters (nutritional; microbiological; physical and chemical) for each item. Irradiation has carried out to different electron accelerators, mainly to ALIN-7 linac (W e ∼6 MeV) and using a special designed microwave equipment (2.45 GHz magnetron of 850 W maximum output power). The samples have been irradiated up to 25 kGy (dose rate ∼ 2.0 kGy/min) and there were treated by microwaves (250 W-550 W) for different exposure time. There have analyzed and presented the influence of these two physical fields on some common physical, biochemical and microbiological properties (mainly the total germ count, CFU/g) of these food materials. The main technological and physical characteristics of the materials are preserved, under irradiation up to 10 kGy and microwave treatment in the case of satisfying the national requirements for food and food grade additives microbiological load. The combined treatment seems to be present a synergistic effect arising on non-thermal basis. From these results it could be pointed out that electron-beam and microwave treatment is feasible and represents an alternative to other hygienization techniques for the dried food ingredients. It should be considered that combined treatments lead to reducing irradiation dose without losing the microbicidal effects

  15. Laboratory-scale dry/wet-milling process for the extraction of starch and gluten from wheat

    Steeneken, P.A.M.; Helmens, H.J.

    2009-01-01

    A laboratory-scale process is presented for the manufacture of starch and gluten from wheat. Main feature of this process is that whole wheat kernels are crushed dry between smooth rolls prior to wet disintegration in excess water in such way that gluten formation is prevented and fibres can be

  16. Bioconversion of Radiation Processed Dried Tomato Pomace to High Protein Animal Fee

    Farag, H.; Diaa El-Din, M.; El-Niely, H. F.G.

    2006-01-01

    The increasing expansion of agro-industrial activity over the last 50 years has led to the accumulation of a large quantity of organic residues all over the world that they have become a threat to the environment. Bioconversion of these wastes seems to be a practical and promising alternative for increasing their nutritional value, transforming them into animal feed and thus producing a value added product. Radiation processing has the capability to reduce or eliminate pathogenic bacteria, insects and parasites, thereby increasing the utilization and sustainable management of waste organic matter from food production and processing while contributing to improve food quality and reducing the environmental impact of the wastes. The main purpose of this study was to evaluate the effect of radiation treatment at 25 kGy and fermentation process by Aspergillus niger, on crude and soluble protein, amino acid profile, available lysine and in vitro digestibility of dried tomato pomace (DTP), the by-product of the tomato canning industry. The study has also, investigated the effect of supplementation of 30% of raw or processed DTP meal in food of male Albino rats for six weeks on body and liver weight evaluation and the effect on blood lipid pattern. The work concluded that the combination between the irradiation of DTP at 25 kGy and fermentation process has increased the nutritional value of treated DTP meal and improved the plasma and liver lipid pattern of rats. Therefore, the combination treatment has beneficial effects on recycling of DTP and permits it to be included in monogastric animals' food without any health hazard or nutritional problem

  17. Generation and manipulation of monodispersed ferrofluid emulsions: the effect of a uniform magnetic field in flow-focusing and T-junction configurations.

    Tan, Say Hwa; Nguyen, Nam-Trung

    2011-09-01

    This paper demonstrates the use of magnetically controlled microfluidic devices to produce monodispersed ferrofluid emulsions. By applying a uniform magnetic field on flow-focusing and T-junction configurations, the size of the ferrofluid emulsions can be actively controlled. The influences of the flow rates, the orientation, and the polarity of the magnetic field on the size of ferrofluid emulsions produced in both flow-focusing and T-junction configurations are compared and discussed.

  18. Research of rheological characteristics and determination of rational parameters of drying process of activated ferment for bakery products

    D. M. Borodulin

    2017-01-01

    Full Text Available The work is aimed at investigating the rheological properties of the ferment in the process of maturation and storage with subsequent determination of the rational parameters of its drying in various drying plants with the analysing of microflora of dried samples. We studied the rheological properties of the ferment using the strain of the lactobacilli L. Acidothilus 146A (activator and without it, which showed that the ferment for the production of special purpose bakery products to non-Newtonian or anomalously viscous liquids described by the Osthald-de-Vale rheological equation. We found that the introduction the strain of the lactobacilli L. Acidothilus 146A helps to reduce the viscosity during maturation by almost 3 times, and when storing the samples – in 2 times, this is indicated by the value of the consistency coefficient. The activator reduces the influence of temperature, so the structure of the ferment becomes more stable. It is easier to further process in this state. Consequently, the energy consumption for production is significantly reduced and the increases expiration date after the strain of the lactobacilli L. Acidothilus 146A is added to the starter for the production of special purpose bakery products. We detected kinetic patterns of drying of the activated ferment in thermoradiation, convective and sublimation dryers under different temperature operating conditions. We have determined the rational parameters of drying the ferment for the production of bakery products of specialized purpose. We analyzed the useful microflora of the dried samples. It has been revealed that microorganisms undergoing convective and sublimation (freeze drying are subjected to the smallest destructive effect. We found that microorganisms are less destroyed by convective and freeze drying. The microbial titer in these samples is at least 1(105CFU/g. While drying by the method of infrared irradiation, this titer is lower by a factor of ten

  19. Contents Changes of Triterpenic Acids, Nucleosides, Nucleobases, and Saccharides in Jujube (Ziziphus jujuba) Fruit During the Drying and Steaming Process.

    Guo, Sheng; Duan, Jin-Ao; Zhang, Ying; Qian, Dawei; Tang, Yuping; Zhu, Zhenhua; Wang, Hanqing

    2015-12-12

    Chinese jujube (Ziziphus jujuba), a medicinal and edible plant, is widely consumed in Asian countries owing to the remarkable health activities of its fruits. To facilitate selection of the suitable processing method for jujube fruits, in this study their contents of triterpenic acids, nucleosides, nucleobases and saccharides after drying and steaming treatment were determined using ultra-high performance liquid chromatography and high performance liquid chromatography coupled with evaporative light scattering detector methods. The results showed that except for sucrose, the content levels of most analytes were increasing in the jujube fruits during drying treatment at 45 °C. The levels of cyclic nucleotides such as adenosine 3',5'-cyclic monophosphate and guanosine 3',5'-cyclic monophosphate, were significantly decreased after the fruits were steamed. Therefore, owing to the bioactivities of these components for human health, the dried fruits would be the better choice as medicinal material or functional food, and dried jujube fruit should not be further steamed.

  20. Ultrafiltration of thin stillage from conventional and e-mill dry grind processes.

    Arora, Amit; Dien, Bruce S; Belyea, Ronald L; Wang, Ping; Singh, Vijay; Tumbleson, M E; Rausch, Kent D

    2011-05-01

    We used ultrafiltration (UF) to evaluate membrane filtration characteristics of thin stillage and determine solids and nutrient compositions of filtered streams. To obtain thin stillage, corn was fermented using laboratory methods. UF experiments were conducted in batch mode under constant temperature and flow rate conditions. Two regenerated cellulose membranes (10 and 100 kDa molecular weight cutoffs) were evaluated with the objective of retaining solids as well as maximizing permeate flux. Optimum pressures for 10 and 100 kDa membranes were 207 and 69 kPa, respectively. Total solids, ash, and neutral detergent fiber contents of input TS streams of dry grind and E-Mill processes were similar; however, fat and protein contents were different (p stillage fractionation had higher mean total solids contents (27.6% to 27.8%) compared to E-Mill (22.2% to 23.4%). Total solids in retentate streams were found similar to those from commercial evaporators used in industry (25% to 35% total solids). Fat contents of retentate streams ranged from 16.3% to 17.5% for the conventional process. A 2% increment in fat concentration was observed in the E-Mill retentate stream. Thin stillage ash content was reduced 60% in retentate streams.

  1. A study of a co-processed dry binder composed of microcrystalline cellulose and glycerol monostearate.

    Mužíková, Jitka; Muchová, Sandra

    2012-10-01

    The paper studies the co-processed dry binder LubriToseTM MCC from the viewpoint of energy evaluation of the compression process, strength and disintegration time of tablets. The results were compared with the identical evaluation of physical mixtures of microcrystalline cellulose with several types of lubricants. LubriTose MCC showed the lowest value of energy for friction, the highest value of energy accumulated by the tablet, and the highest plasticity of all tableting materials under study. There were no marked differences in the values of the energy of decompression. The tensile strength of tablets from LubriTose MCC was lower than in those from the mixture of Vivapur® 12 and glycerol monostearate, in the compression forces of 4 and 5 kN it was comparable with the tensile strength of tablets from Vivapur 12 with Poloxamer 407. Disintegration time of tablets from LubriTose MCC was shorter than that of those from Vivapur 12 with glycerol monostearate at the compression force of 3 kN, in the case of the compression forces of 4 and 5 kN no statistically significant difference was found between the values of these tableting materials.

  2. Effects of Processing Temperature on Color Properties of Dry-Cured Hams Made without Nitrite

    Giovanni Parolari

    2016-04-01

    Full Text Available Dry cured hams were investigated for their ability to develop red color even at low temperature (3–4 °C and in the absence of added nitrites; results were compared with those obtained from nitrite-free hams made at conventional warm maturing temperatures. Colorimetric parameters (L*, a*, b*, and hue and concentration of the main pigments Zn protoporphyrin IX (ZnPP and heme were measured at three stages of preparation (six, nine, and 12 months, showing that red color was successfully formed at low temperatures, though at a slower rate and less intensively than under warm conditions. Major differences in the pattern of color development were found with the two processing temperatures. While the typical features of an enzyme-dependent mechanism, with a progressive drop in enzyme activity paralleling the synthesis of Zn protoporphyrin IX, were observed at warm temperatures, the same did not occur in cold-made hams, where the enzyme activity was almost unchanged throughout the process. These results, along with data from a descriptive sensory analysis, are supportive of a non-enzymatic mechanism leading to ZnPP (hence the red color under cold conditions, with an estimated three-month delay compared with nitrite-free hams manufactured in a warm maturing regimen.

  3. Effects of Processing Temperature on Color Properties of Dry-Cured Hams Made without Nitrite.

    Parolari, Giovanni; Aguzzoni, Agnese; Toscani, Tania

    2016-04-29

    Dry cured hams were investigated for their ability to develop red color even at low temperature (3-4 °C) and in the absence of added nitrites; results were compared with those obtained from nitrite-free hams made at conventional warm maturing temperatures. Colorimetric parameters (L*, a*, b*, and hue) and concentration of the main pigments Zn protoporphyrin IX (ZnPP) and heme were measured at three stages of preparation (six, nine, and 12 months), showing that red color was successfully formed at low temperatures, though at a slower rate and less intensively than under warm conditions. Major differences in the pattern of color development were found with the two processing temperatures. While the typical features of an enzyme-dependent mechanism, with a progressive drop in enzyme activity paralleling the synthesis of Zn protoporphyrin IX, were observed at warm temperatures, the same did not occur in cold-made hams, where the enzyme activity was almost unchanged throughout the process. These results, along with data from a descriptive sensory analysis, are supportive of a non-enzymatic mechanism leading to ZnPP (hence the red color) under cold conditions, with an estimated three-month delay compared with nitrite-free hams manufactured in a warm maturing regimen.

  4. Phycocyanin stability in microcapsules processed by spray drying method using different inlet temperature

    Purnamayati, L.; Dewi, EN; Kurniasih, R. A.

    2018-02-01

    Phycocyanin is natural blue colorant which easily damages by heat. The inlet temperature of spray dryer is an important parameter representing the feature of the microcapsules.The aim of this study was to investigate the phycocyanin stability of microcapsules made from Spirulina sp with maltodextrin and κ-Carrageenan as the coating material, processed by spray drying method in different inlet temperature. Microcapsules were processed in three various inlet temperaturei.e. 90°C, 110°C, and 130°C, respectively. The results indicated that phycocyanin microcapsule with 90°C of inlet temperature produced the highest moisture content, phycocyanin concentration and encapsulation efficiency of 3,5%, 1,729% and 29,623%, respectively. On the other hand, the highest encapsulation yield was produced by 130°C of theinlet temperature of 29,48% and not significantly different with 110°C. The results of Scanning Electron Microscopy (SEM) showed that phycocyanin microcapsules with 110°C of inlet temperature produced the most rounded shape. To sum up, 110°C was the best inlet temperature to phycocyanin microencapsulation by the spray dryer.

  5. Effects of Processing Temperature on Color Properties of Dry-Cured Hams Made without Nitrite

    Parolari, Giovanni; Aguzzoni, Agnese; Toscani, Tania

    2016-01-01

    Dry cured hams were investigated for their ability to develop red color even at low temperature (3–4 °C) and in the absence of added nitrites; results were compared with those obtained from nitrite-free hams made at conventional warm maturing temperatures. Colorimetric parameters (L*, a*, b*, and hue) and concentration of the main pigments Zn protoporphyrin IX (ZnPP) and heme were measured at three stages of preparation (six, nine, and 12 months), showing that red color was successfully formed at low temperatures, though at a slower rate and less intensively than under warm conditions. Major differences in the pattern of color development were found with the two processing temperatures. While the typical features of an enzyme-dependent mechanism, with a progressive drop in enzyme activity paralleling the synthesis of Zn protoporphyrin IX, were observed at warm temperatures, the same did not occur in cold-made hams, where the enzyme activity was almost unchanged throughout the process. These results, along with data from a descriptive sensory analysis, are supportive of a non-enzymatic mechanism leading to ZnPP (hence the red color) under cold conditions, with an estimated three-month delay compared with nitrite-free hams manufactured in a warm maturing regimen. PMID:28231128

  6. CFD Analysis to Calculate the Optimal Air Velocity in Drying Green Tea Process Using Fluidized Bed Dryer

    Yohana, Eflita; Nugraha, Afif Prasetya; Diana, Ade Eva; Mahawan, Ilham; Nugroho, Sri

    2018-02-01

    Tea processing is basically distinguished into three types which black tea, green tea, and oolong tea. Green tea is processed by heating and drying the leaves. Green tea factories in Indonesia are generally using the process of drying by panning the leaves. It is more recommended to use the fluidization process to speed up the drying process as the quality of the tea can be maintained. Bubbling fluidization is expected to occur in this research. It is a process of bubbles are formed in the fluidization. The effectiveness of the drying process in a fluidized bed dryer machine needs to be improved by using a CFD simulation method to proof that umf < u < ut, where the average velocity value is limited by the minimum and the maximum velocity of the calculation the experimental data. The minimum and the maximum velocity value of the fluidization is 0.96 m/s and 8.2 m/s. The result of the simulation obtained that the average velocity of the upper bed part is 1.81 m/s. From the results obtained, it can be concluded that the calculation and the simulation data is in accordance with the condition of bubbling fluidization in fluidized bed dryer.

  7. The effect of acoustic and solar energy on drying process of pistachios

    Kouchakzadeh, Ahmad

    2013-01-01

    Highlights: ► In this research, accelerated drying of pistachios under open sun by applying power ultrasound was investigated. ► No constant falling rate period of drying was observed. ► By applying the 20 kHz ultrasound about 17 W/kg, the drying period could be reduced to 4 h. - Abstract: A new approach of ultrasound-assisted sun drying was tested in this study using a flat bed as product support and two extensional piezoelectric Bolt-clamped 20 kHz transducer elements. The mono layer of moist unshelled pistachios was dried under open sun by applying 500 and 1000 W power ultrasound. The results showed that the Page model was found to be the most suitable for describing drying curve of pistachios. But, the Logarithmic model was described to satisfactorily drying curve of pistachios for open sun method when the ultrasound power was turned off. By applying the ultrasound about 17 W/kg moist pistachios in thin layer, the drying period could be reduced to 4 h

  8. Effect of Dietary Processed Sulfur Supplementation on Texture Quality, Color and Mineral Status of Dry-cured Ham.

    Kim, Ji-Han; Ju, Min-Gu; Yeon, Su-Jung; Hong, Go-Eun; Park, WooJoon; Lee, Chi-Ho

    2015-01-01

    This study was performed to investigate the chemical composition, mineral status, oxidative stability, and texture attributes of dry-cured ham from pigs fed processed sulfur (S, 1 g/kg feed), and from those fed a basal diet (CON), during the period from weaning to slaughter (174 d). Total collagen content and soluble collagen of the S group was significantly higher than that of the control group (pham (pham from the control group, that from the S group exhibited lower springiness and gumminess; these results suggest that feeding processed sulfur to pigs can improve the quality of the texture and enhance the oxidative stability of dry-cured ham.

  9. Drying process of fermented inulin fiber concentrate by Bifidobacterium bifidum as a dietary fiber source for cholesterol binder

    Susilowati, Agustine; Aspiyanto, Ghozali, Muhammad

    2017-11-01

    Fermentation on inulin hydrolysate as fructooligosaccharides (FOS) by Bifidobacterium bifidum as a result of hydrolysis by inulase enzyme of Scopulariopsis sp.-CBS1 fungi has been performed to bind cholesterol. Their applications on preparation of fermented pour beverages was conducted via a series of concentration process using dead-end Stirred Ultrafiltration Cell (SUFC) mode at stirrer rotation of 400 rpm, room temperature and pressure of 40 psia for 0 minute (pre-concentration process) as concentrate (A) and 45 minutes as concentrate (B), and drying process using vacuum dryer at 30 °C and 22 cm Hg for 0, 8, 16, 24, 32, 40 and 48 hours. Based on optimization of Total Dietary Fiber (TDF), the best time of drying process was achieved for 40 hours. Long time of drying process would increase TDF and total solids, decreased total acids, and fluctuated dissolved protein and Cholesterol Binding Capacity (CBC). At the optimum condition of drying process was get fermented inulin fiber powder from concentration processes using both UF as pre process (0 minute) as concentrate (A) and UF for 45 minutes as concentrate (B) with compositions of total solids of 92.31 % and 93.67 %, TDF of 59.07 % (dry weight) and 69.28 %, total acids of 7.03 % and 7.5 %, dissolved protein of 3.95 mg/mL and 3.05 mg/mL, and CBC pH 2 15.71 mg/g and 16.8 mg/g, respectively. Concentration process through dead-end SUFC mode gave distribution of particles with better smoothness level than without through dead-end SUFC mode.

  10. DEVELOPMENT OF MATHEMATICAL MODEL OF PROCESS OF BLACK CURRANT BERRIES DRYING IN VACUUMDEVICE WITH THE MICROWAVE POWER SUPPLY

    S. T. Antipov

    2014-01-01

    Full Text Available Summary. The mathematical model allowed to reproduce and study at qualitative level the change of berries form and the structure of the berries layer in the course of drying. The separate berry in the course of drying loses gradually its elasticity, decreases in volume, the peel gathers in folds, there appear internal emptiness. In the course of drying the berries layer decreases in thickness, contacting berries stick strongly with each other due to the coordinated folds of peel appearing, the layer is condensed due to penetration of the berries which have lost elasticity into emptiness between them. The model with high specification describes black currant drying process and therefore has a large number of the parameters available to change. Among them three most important technological parameters, influencing productivity and the drying quality are chosen: the power of microwave radiation P, thickness of the berries layer h, environmental pressure p. From output indicators of the model the most important are three functions from time: dependence of average humidity of the layer on time Wcp (t, dependence of the speed of change of average humidity on time dWcp (t/dt, dependence of the layer average temperature on time Tср (t. On the standard models classification the offered model is algorithmic, but not analytical. It means that output characteristics of model are calculated with the entrance ones, not by analytical transformations (it is impossible principally for the modeled process, but by means of spatial and temporary sampling and the corresponding calculation algorithm. Detailed research of the microwave drying process by means of the model allows to allocate the following stages: fast heating, the fast dehydration, the slowed-down dehydration, consolidation of a layer of a product, final drying, heating after dehydration.

  11. Effects of steam-microwave blanching and different drying processes on drying characteristics and quality attributes of Thunbergia laurifolia Linn. leaves.

    Phahom, Traiphop; Phoungchandang, Singhanat; Kerr, William L

    2017-08-01

    Dried Thunbergia laurifolia leaves are usually prepared using tray drying, resulting in products that have lost substantial amounts of bioactive compounds and antioxidant activity. The maturity of the raw material, blanching techniques and drying methods were investigated in order to select the best condition to produce high qualities of dried T. laurifolia leaves. The 1st stage of maturity was selected and steam-microwave blanching (SMB) for 4 min was adequate for blanching leading to the maximum recovery of bioactive compounds. The modified Halsey model was the best desorption isotherm model. A new drying model proposed in this study was the best to fit the drying curves as compared to five common drying models. Moisture diffusivities were increased with the increase of drying temperature when combining SMB and heat pump-dehumidified drying. Microwave heat pump-dehumidified drying (MHPD) provided the shortest drying time, high specific moisture extraction rate (SMER) and could reduce drying time by 67.5% and increase caffeic acid and quercetin by 51.24% and 60.89%, respectively. MHPD was found to be the best drying method and provided the highest antioxidant activity and bioactive compounds content, high SMER and short drying time. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  12. The Influence of Log Felling Season on the Extent of Discoloration in Rubberwood Sawn Timber during the Kiln Drying Process

    Jegatheswaran Ratnasingam

    2016-04-01

    Full Text Available This study investigated the effects of felling season on the discoloration of rubberwood sawn timber during conventional kiln drying. The samples were collected throughout the year 2015 to monitor the variation of free sugars and starch content in the rubberwood logs. Two batches of logs, one from the rainy season and the other from the dry season, were felled and sawn for experimentation. The findings showed that discoloration was more prominent in sawn timber obtained from logs felled during the dry season. The amount of free sugars and starch in the logs had a strong influence on the extent of discoloration in the rubberwood sawn timber during the kiln drying process. A higher amount of free sugars and starch in the logs felled during the dry season increased the incidence of blue stain on these logs. The results of this study conclusively showed that discoloration in rubberwood can be minimized by the choice of log felling season and the use of an appropriate drying technique, which will inevitably improve the aesthetic appeal of the wood.

  13. Noise Reduction Properties of an Experimental Bituminous Slurry with Crumb Rubber Incorporated by the Dry Process

    Moisés Bueno

    2014-08-01

    Full Text Available Nowadays, cold technology for asphalt pavement in the field of road construction is considered as an alternative solution to conventional procedures from both an economic and environmental point of view. Among these techniques, bituminous slurry surfacing is obtaining an important role due to the properties of the obtained wearing course. The functional performance of this type of surfaces is directly related to its rough texture. Nevertheless, this parameter has a significant influence on the tire/road noise generation. To reduce this undesirable effect on the sound performance, new designs of elastic bituminous slurries have been developed. Within the FENIX project, this work presents the acoustical characterization of an experimental bituminous slurry with crumb rubber from wasted automobile tires incorporated by the dry process. The obtained results show that, under controlled operational parameters, the close proximity sound levels associated to the experimental slurry are considerably lower than those emitted by a conventional slurry wearing course. However, after one year of supporting traffic loads and different weather conditions, the evaluated bituminous slurry, although it conserves the original noise reduction properties in relation to the conventional one, noticeably increases the generated sound emission. Therefore, it is required to continue improving the design of experimental surfaces in order to enhance its long-term performance.

  14. Mechanical and dielectric characterization of hemp fibre reinforced polypropylene (HFRPP by dry impregnation process

    2010-03-01

    Full Text Available Natural fibres such as jute, coir, sisal, bamboo and pineapple are known to have high specific strength and can be effectively used in composites in various applications. The use of hemp fibres to reinforce the polymer aroused great interest and expectations amongst scientists and materials engineers. In this paper, composites with isotactic polypropylene (iPP matrix and hemp fibres were studied. These materials were manufactured via the patented FIBROLINE process based on the principle of the dry impregnation of a fibre assembly with a thermoplastic powder (iPP, using an alternating electric field. The aim of this paper is to show the influence of fibre/matrix interfaces on dielectric properties coupled with mechanical behaviours. Fibres or more probably the fibre/matrix interfaces allow the diffusion of electric charges and delocalise the polarisation energy. In this way, damages are limited during mechanical loading and the mechanical properties of the composites increase. The structure of composite samples was investigated by X-ray and FTIR analysis. The mechanical properties were analysed by quasistatic and dynamic tests. The dielectric investigations were carried out using the SEMME (Scanning Electron Microscope Mirror Effect method coupled with the measurement of the induced current (ICM.

  15. Inoculation of starter cultures in a semi-dry coffee (Coffea arabica) fermentation process.

    Evangelista, Suzana Reis; Miguel, Maria Gabriela da Cruz Pedrozo; Cordeiro, Cecília de Souza; Silva, Cristina Ferreira; Pinheiro, Ana Carla Marques; Schwan, Rosane Freitas

    2014-12-01

    The aim of this study was to evaluate the use of yeasts as starter cultures in coffee semi-dry processing. Arabica coffee was inoculated with one of the following starter cultures: Saccharomyces cerevisiae UFLA YCN727, S. cerevisiae UFLA YCN724, Candida parapsilosis UFLA YCN448 and Pichia guilliermondii UFLA YCN731. The control was not inoculated with a starter culture. Denaturing gradient gel electrophoresis (DGGE) was used to assess the microbial population, and organic acids and volatile compounds were quantified by HPLC and HS-SPME/GC, respectively. Sensory analyses were evaluated using the Temporal Dominance of Sensations (TDS). DGGE analysis showed that the inoculated yeasts were present throughout the fermentation. Other yeast species were also detected, including Debaryomyces hansenii, Cystofilobasidium ferigula and Trichosporon cavernicola. The bacterial population was diverse and was composed of the following genera: Weissella, Leuconostoc, Gluconobacter, Pseudomonas, Pantoea, Erwinia and Klebsiella. Butyric and propionic acids, were not detected in any treatment A total of 47 different volatiles compounds have been identified. The coffee inoculated with yeast had a caramel flavor that was not detected in the control, as assessed by TDS. The use of starter cultures during coffee fermentation is an interesting alternative for obtaining a beverage quality with distinctive flavor. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Microbial Analysis of Australian Dry Lake Cores; Analogs For Biogeochemical Processes

    Nguyen, A. V.; Baldridge, A. M.; Thomson, B. J.

    2014-12-01

    Lake Gilmore in Western Australia is an acidic ephemeral lake that is analogous to Martian geochemical processes represented by interbedded phyllosilicates and sulfates. These areas demonstrate remnants of a global-scale change on Mars during the late Noachian era from a neutral to alkaline pH to relatively lower pH in the Hesperian era that continues to persist today. The geochemistry of these areas could possibly be caused by small-scale changes such as microbial metabolism. Two approaches were used to determine the presence of microbes in the Australian dry lake cores: DNA analysis and lipid analysis. Detecting DNA or lipids in the cores will provide evidence of living or deceased organisms since they provide distinct markers for life. Basic DNA analysis consists of extraction, amplification through PCR, plasmid cloning, and DNA sequencing. Once the sequence of unknown DNA is known, an online program, BLAST, will be used to identify the microbes for further analysis. The lipid analysis approach consists of phospholipid fatty acid analysis that is done by Microbial ID, which will provide direct identification any microbes from the presence of lipids. Identified microbes are then compared to mineralogy results from the x-ray diffraction of the core samples to determine if the types of metabolic reactions are consistent with the variation in composition in these analog deposits. If so, it provides intriguing implications for the presence of life in similar Martian deposits.

  17. Lipid oxidation and fatty acid composition in salt-dried yellow croaker ( Pseudosciaena polyactis) during processing

    Cai, Qiuxing; Wu, Yanyan; Li, Laihao; Wang, Yueqi; Yang, Xianqing; Zhao, Yongqiang

    2017-10-01

    Lipid oxidation in salt-dried yellow croaker ( Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value (POV), the thiobarbituric acid reactive substances (TBARS) value, and oxidative-relative lipoxygenase (LOX) activity. Additionally, fatty acids were analyzed using gas chromatography-mass spectrometry. Both POV and TBARS increased significantly ( P acids were identified. Combined eicosapentaenoic acid (EPA; C20:5n3) and docosahexaenoic acid (DHA; C22:6n3) content varied between (19.20 ± 0.37) mg g-1 and (23.45 ± 1.05) mg g-1. The polyunsaturated fatty acid/saturated fatty acid (PUFA/SFA) ratio in yellow croaker was 0.73-1.10, and the n-6/n-3 PUFA ratio was approximately 0.13-0.20. The contents of most fatty acids varied significantly ( P acids are potential markers for evaluating lipid oxidation in fish muscle because there was a significant correlation between these markers and TBARS and LOX activity ( P 0.931.

  18. Transport and solubility of Hetero-disperse dry deposition particulate matter subject to urban source area rainfall-runoff processes

    Ying, G.; Sansalone, J.

    2010-03-01

    SummaryWith respect to hydrologic processes, the impervious pavement interface significantly alters relationships between rainfall and runoff. Commensurate with alteration of hydrologic processes the pavement also facilitates transport and solubility of dry deposition particulate matter (PM) in runoff. This study examines dry depositional flux rates, granulometric modification by runoff transport, as well as generation of total dissolved solids (TDS), alkalinity and conductivity in source area runoff resulting from PM solubility. PM is collected from a paved source area transportation corridor (I-10) in Baton Rouge, Louisiana encompassing 17 dry deposition and 8 runoff events. The mass-based granulometric particle size distribution (PSD) is measured and modeled through a cumulative gamma function, while PM surface area distributions across the PSD follow a log-normal distribution. Dry deposition flux rates are modeled as separate first-order exponential functions of previous dry hours (PDH) for PM and suspended, settleable and sediment fractions. When trans-located from dry deposition into runoff, PSDs are modified, with a d50m decreasing from 331 to 14 μm after transport and 60 min of settling. Solubility experiments as a function of pH, contact time and particle size using source area rainfall generate constitutive models to reproduce pH, alkalinity, TDS and alkalinity for historical events. Equilibrium pH, alkalinity and TDS are strongly influenced by particle size and contact times. The constitutive leaching models are combined with measured PSDs from a series of rainfall-runoff events to demonstrate that the model results replicate alkalinity and TDS in runoff from the subject watershed. Results illustrate the granulometry of dry deposition PM, modification of PSDs along the drainage pathway, and the role of PM solubility for generation of TDS, alkalinity and conductivity in urban source area rainfall-runoff.

  19. Changes in the carotenoid metabolism of capsicum fruits during application of modelized slow drying process for paprika production.

    Pérez-Gálvez, Antonio; Hornero-Méndez, Dámaso; Mínguez-Mosquera, María Isabel

    2004-02-11

    A temperature profile simulating the traditional slow drying process of red pepper fruits, which is conducted in La Vera region (Spain) for paprika production, was developed. Carotenoid and ascorbic acid content, as well as moisture of fruits, were monitored during the slow drying process designed. Data obtained suggested that the evolution of carotenoid concentration, the main quality trait for paprika, directly depend on the physical conditions imposed. During the drying process, three different stages could be observed in relation to the carotenoids. The first stage corresponds to a physiological adaptation to the new imposed conditions that implied a decrease (ca. 20%) in the carotenoid content during the first 24 h. After that short period and during 5 days, a second stage was noticed, recovering the biosynthetic (carotenogenic) capability of the fruits, which denotes an accommodation of the fruits to the new environmental conditions. During the following 48 h (third stage) a sharp increase in the carotenoid content was observed. This last phenomenon seems to be related with an oxidative-thermal stress, which took place during the first stage, inducing a carotenogenesis similar to that occurring in over-ripening fruits. Results demonstrate that a fine control of the temperature and moisture content would help to positively modulate carotenogenesis and minimize catabolism, making it possible to adjust the drying process to the ripeness stage of fruits with the aim of improving carotenoid retention and therefore quality of the resulting product. In the case of ascorbic acid, data demonstrated that this compound is very sensitive to the drying process, with a decrease of about 76% during the first 24 h and remaining only at trace levels during the rest of the process. Therefore, no antioxidant role should be expected from ascorbic acid during the whole process and in the corresponding final product (paprika), despite that red pepper fruit is well-known to be rich

  20. High-pressure treatment of wood - combination of mechanical and thermal drying in the ''I/D process''

    Stahl, M. [Bundesforschungsanstalt fuer Ernaehrung, Institut fuer Verfahrenstechnik, Haid-und-Neu-Str. 9, D-76131 Karlsruhe (Germany); Bentz, M. [Institut fuer Mechanische Verfahrenstechnik und Mechanik, Universitaet Karlsruhe (T.H.), D-76128 Karlsruhe (Germany)

    2004-11-01

    Thermal drying of materials with internal pores is always a time-consuming and energy-intensive step within a production process. For chemical and pharmaceutical mass products and, in particular, for wood as an important raw material it is desirable to reduce the water content before thermal treatment by mechanical operations. The wood-processing industry, facing a rising stress of competition, is forced more than ever to offer high-quality products at lowest prices. Today, drying of timber is mostly done by air drying or by technical drying in kiln dryers. In any case, drying is necessary to prevent deterioration in quality by shrinkage, formation of cracks, discoloration or infestation. A new process of dewatering wood by combining mechanical and thermal means has been developed at the University of Karlsruhe. Compared to conventional drying processes, short drying times and a low residual moisture content can be achieved and, thus, energy consumption and costs can be reduced. In industrial wood drying only thermal processes (e.g., convective kiln drying, vacuum drying, etc.) have been established because so far no method has been known for removing liquid by mechanical force without significant change in wood structure. With the new I/D process chances for alternatives to conventional thermal drying or for mechanothermal applications are offered. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  1. State of polyphenols in the drying process of fruits and vegetables.

    McSweeney, M; Seetharaman, K

    2015-01-01

    This review presents an overview of drying technologies and its impact on the polyphenol content of vegetables and fruits. Polyphenols contribute to many health benefits and can act as antioxidants. Specifically an increased intake of polyphenols has been shown to decrease the incidence of cardiovascular disease; furthermore, it has been shown to help reduce the risk of neurodegenerative diseases in humans. Many researchers have reported on the effect of different drying techniques on the polyphenol content in fruits and vegetables. Polyphenol degradation mechanisms proposed in literature and pretreatments that potentially lead to higher retention of polyphenols during drying are also discussed.

  2. Potential of Near-Infrared Chemical Imaging as Process Analytical Technology Tool for Continuous Freeze-Drying.

    Brouckaert, Davinia; De Meyer, Laurens; Vanbillemont, Brecht; Van Bockstal, Pieter-Jan; Lammens, Joris; Mortier, Séverine; Corver, Jos; Vervaet, Chris; Nopens, Ingmar; De Beer, Thomas

    2018-04-03

    Near-infrared chemical imaging (NIR-CI) is an emerging tool for process monitoring because it combines the chemical selectivity of vibrational spectroscopy with spatial information. Whereas traditional near-infrared spectroscopy is an attractive technique for water content determination and solid-state investigation of lyophilized products, chemical imaging opens up possibilities for assessing the homogeneity of these critical quality attributes (CQAs) throughout the entire product. In this contribution, we aim to evaluate NIR-CI as a process analytical technology (PAT) tool for at-line inspection of continuously freeze-dried pharmaceutical unit doses based on spin freezing. The chemical images of freeze-dried mannitol samples were resolved via multivariate curve resolution, allowing us to visualize the distribution of mannitol solid forms throughout the entire cake. Second, a mannitol-sucrose formulation was lyophilized with variable drying times for inducing changes in water content. Analyzing the corresponding chemical images via principal component analysis, vial-to-vial variations as well as within-vial inhomogeneity in water content could be detected. Furthermore, a partial least-squares regression model was constructed for quantifying the water content in each pixel of the chemical images. It was hence concluded that NIR-CI is inherently a most promising PAT tool for continuously monitoring freeze-dried samples. Although some practicalities are still to be solved, this analytical technique could be applied in-line for CQA evaluation and for detecting the drying end point.

  3. Formulation and process considerations for the design of sildenafil-loaded polymeric microparticles by vibrational spray-drying

    Beck-Broichsitter, Moritz; Bohr, Adam; Aragão-Santiago, Leticia

    2017-01-01

    CONTEXT AND OBJECTIVE: The current study reports the preparation and characterization of sildenafil-loaded poly(lactide-co-glycolide) (PLGA)-based microparticles (MPs) by means of vibrational spray-drying. Emphasis was placed on relevant formulation and process parameters with influence on the pr......CONTEXT AND OBJECTIVE: The current study reports the preparation and characterization of sildenafil-loaded poly(lactide-co-glycolide) (PLGA)-based microparticles (MPs) by means of vibrational spray-drying. Emphasis was placed on relevant formulation and process parameters with influence......), respectively. Furthermore, interactions between sildenafil and the PLGA matrix were observed for the spray-dried MPs. Optimization of spray-drying conditions allowed for a fabrication of defined MPs (size range of ∼4-8 μm) displaying a high sildenafil encapsulation efficiency (>90%) and sustained sildenafil...... properties of the prepared powders. CONCLUSION: Identification of relevant formulation and spray-drying parameters enabled the fabrication of tailored sildenafil-loaded PLGA-based MPs, which meet the needs of the individual application (e.g. controlled drug delivery to the lungs)....

  4. Shape and fission instabilities of ferrofluids in non-uniform magnetic fields

    Vieu, Thibault; Walter, Clément

    2018-04-01

    We study static distributions of ferrofluid submitted to non-uniform magnetic fields. We show how the normal-field instability is modified in the presence of a weak magnetic field gradient. Then we consider a ferrofluid droplet and show how the gradient affects its shape. A rich phase transitions phenomenology is found. We also investigate the creation of droplets by successive splits when a magnet is vertically approached from below and derive theoretical expressions which are solved numerically to obtain the number of droplets and their aspect ratio as function of the field configuration. A quantitative comparison is performed with previous experimental results, as well as with our own experiments, and yields good agreement with the theoretical modeling.

  5. Investigations on electrostatic dissipative materials derived from Poly(vinyl alcohol/ferrofluid composites

    Winatthakan Phuchaduek

    2013-10-01

    Full Text Available Biodegradable polymer composites based on polyvinyl alcohol (PVA and ferrofluid (FF were prepared by solutioncasting method. Such composites were characterized by various methods in order to evaluate their potential for use as elec-trostatic dissipative (ESD materials. Effects of ferrofluid content on mechanical, thermal, and electrical properties of thecomposites were investigated. The morphology of the composites was examined by SEM and the water contact angle on thecomposite surface was also measured. Experimental results showed that surface resistivity of the composites can be reducedby the addition of FF. The abrupt transition of such resistivity occurred in the concentration range 20-30 wt.% FF. Theconductive mechanism of the proposed composites is a complex manner, including contact conduction and tunnelingconduction.

  6. Investigation of magneto-optical properties of ferrofluids by laser light scattering techniques

    Nepomnyashchaya, E.K., E-mail: elina.nep@gmail.com [Department of Quantum Electronics, Peter the Great Saint Petersburg Polytechnic University, Saint Petersburg 195251 (Russian Federation); Prokofiev, A.V.; Velichko, E.N. [Department of Quantum Electronics, Peter the Great Saint Petersburg Polytechnic University, Saint Petersburg 195251 (Russian Federation); Pleshakov, I.V.; Kuzmin, Yu I. [Department of Quantum Electronics, Peter the Great Saint Petersburg Polytechnic University, Saint Petersburg 195251 (Russian Federation); Laboratory of Quantum Electronics, Ioffe Institute, Saint-Petersburg 194021 (Russian Federation)

    2017-06-01

    Investigation of magnetooptical characteristics of ferrofluids is an important task aimed at the development of novel optoelectronic systems. This article reports on the results obtained in the experimental studies of the factors that affect the intensity and spatial distribution of the laser radiation scattered by magnetic particles and their agglomerates in a magnetic field. Laser correlation spectroscopy and direct measurements of laser radiation scattering for studies of the interactions and magnetooptical properties of magnetic particles in solutions were employed. The objects were samples of nanodispersed magnetite (Fe{sub 3}O{sub 4}) suspended in kerosene and in water. Our studies revealed some new behavior of magnetic particles in external magnetic and light fields, which make ferrofluids promising candidates for optical devices.

  7. Predictive modeling of infrared radiative heating in tomato dry-peeling process: Part II. Model validation and sensitivity analysis

    A predictive mathematical model was developed to simulate heat transfer in a tomato undergoing double sided infrared (IR) heating in a dry-peeling process. The aims of this study were to validate the developed model using experimental data and to investigate different engineering parameters that mos...

  8. Melt extrusion vs. spray drying: The effect of processing methods on crystalline content of naproxen-povidone formulations.

    Haser, Abbe; Cao, Tu; Lubach, Joe; Listro, Tony; Acquarulo, Larry; Zhang, Feng

    2017-05-01

    Our hypothesis is that melt extrusion is a more suitable processing method than spray drying to prepare amorphous solid dispersions of drugs with a high crystallization tendency. Naproxen-povidone K25 was used as the model system in this study. Naproxen-povidone K25 solid dispersions at 30% and 60% drug loadings were characterized by modulated DSC, powder X-ray diffraction, FT-IR, and solid-state 13 C NMR to identify phase separation and drug recrystallization during processing and storage. At 30% drug loading, hydrogen bond (H-bond) sites of povidone K25 were not saturated and the glass transition (T g ) temperature of the formulation was higher. As a result, both melt-extruded and spray-dried materials were amorphous initially and remained so after storage at 40°C. At 60% drug loading, H-bond sites were saturated, and T g was low. We were not able to prepare amorphous materials. The initial crystallinity of the formulations was 0.4%±0.2% and 5.6%±0.6%, and increased to 2.7%±0.3% and 21.6%±1.0% for melt-extruded and spray-dried materials, respectively. Spray-dried material was more susceptible to re-crystallization during processing, due to the high diffusivity of naproxen molecules in the formulation matrix and lack of kinetic stabilization from polymer solution. A larger number of crystalline nucleation sites and high surface area made the spray-dried material more susceptible to recrystallization during storage. This study demonstrated the unique advantages of melt extrusion over spray drying for the preparation of amorphous solid dispersions of naproxen at high drug level. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Visualization and comparative investigations of pulsating ferro-fluid heat pipe

    Gandomkar, A.; Saidi, M.H.; Shafii, M.B.; Vandadi, M.; Kalan, K.

    2017-01-01

    Highlights: • Nanofluid was unstable and also agglomerated and deposited in the copper pipe; whereas, it was stable in the Pyrex pipe. • For the Pyrex heat pipe, applying the magnetic field caused weaker performance. • For Pyrex PHP, increasing the concentration improved the performance. • For the copper PHP, applying the magnetic field had the best performance. • For copper PHP, concentration of the nanofluid in each case of the magnet and input power has an optimum value. - Abstract: Pulsating heat pipes (PHPs) are among the best solutions for the electronics cooling due to their low cost, effectiveness and being passive. Experiments to study the effective factors on heat transfer performance have been designed and as a result, improvement of ferrofluid PHP performance has been achieved. Two different heat pipes made of copper and glass were prepared to investigate the behavior of magnetic nanofluids. In order to find the best condition for heat transfer performance, different concentrations of nanofluid with a filling ratio of 50% were tested in 3 different cases of magnetic field. The results indicated that the ferrofluid is more stable in the glass PHP. It also shows that the presence of magnetic field in the copper PHP has the best outcome while in the glass PHP, the absence of magnetic field results better. It was detected that using a more concentrated ferrofluid causes a better performance in the copper PHP only when the magnetic field is applied, while in the glass PHP, increasing the concentration of ferrofluid improves the performance of the PHP in all conditions of applying the magnetic field.

  10. Spheroidal and conical shapes of ferrofluid-filled capsules in magnetic fields

    Wischnewski, Christian; Kierfeld, Jan

    2018-04-01

    We investigate the deformation of soft spherical elastic capsules filled with a ferrofluid in external uniform magnetic fields at fixed volume by a combination of numerical and analytical approaches. We develop a numerical iterative solution strategy based on nonlinear elastic shape equations to calculate the stretched capsule shape numerically and a coupled finite element and boundary element method to solve the corresponding magnetostatic problem and employ analytical linear response theory, approximative energy minimization, and slender-body theory. The observed deformation behavior is qualitatively similar to the deformation of ferrofluid droplets in uniform magnetic fields. Homogeneous magnetic fields elongate the capsule and a discontinuous shape transition from a spheroidal shape to a conical shape takes place at a critical field strength. We investigate how capsule elasticity modifies this hysteretic shape transition. We show that conical capsule shapes are possible but involve diverging stretch factors at the tips, which gives rise to rupture for real capsule materials. In a slender-body approximation we find that the critical susceptibility above which conical shapes occur for ferrofluid capsules is the same as for droplets. At small fields capsules remain spheroidal and we characterize the deformation of spheroidal capsules both analytically and numerically. Finally, we determine whether wrinkling of a spheroidal capsule occurs during elongation in a magnetic field and how it modifies the stretching behavior. We find the nontrivial dependence between the extent of the wrinkled region and capsule elongation. Our results can be helpful in quantitatively determining capsule or ferrofluid material properties from magnetic deformation experiments. All results also apply to elastic capsules filled with a dielectric liquid in an external uniform electric field.

  11. Small-Angle Neutron Scattering investigations of ferrofluids with different carrier liquids

    Balasoiu, M.; Avdeev, M. V.; Hasegan, D.; Ghenescu, V.; Ghenescu, M.; Bica, D.; Vekas, L.

    2004-01-01

    The aim of this paper is to present a method to investigate the properties of magnetic fluids by means of small angle neutron scattering (SANS). Ferrofluids are dispersions of small, single-domain magnetic particles suspended in a fluid carrier. The neutron scattering methods have been largely used the last two decades for the determination of structural properties of magnetic liquids at microscopic level. There can be investigated the structure of the particle, the aggregation phenomena, the magnetic liquid dynamics, particle-surfactant interaction, surfactant liquid-base interaction and structure and magnetic behavior of the samples. SANS is often used in structural studies of ferrofluids exploring two specific features of neutrons, the possibility of wide contrast variation using protonated/deuterated components and high magnetic scattering from ferromagnetics. This method can be effectively used for determination of the structural parameters of ferrofluids at the scale interval of 1-100 nm. In previous SANS experiments with ferrofluids of the same type it was shown that the nuclear scattering is described well by the spherical core-shell model (magnetite core plus surfactant shell) in a wide interval of momentum transfer (0.05 - 5 nm -1 ) and no significant effects of aggregation and interparticle interaction were observed in this interval for the magnetite concentration up to 5 vol. %. Experiments on small angle neutron scattering were carried out on SANS instrument YuMO in function at IBR-2 high pulsed reactor at the Frank Laboratory of Neutron Physics, Joint Institute of Nuclear Research, Dubna, Russia. (authors)

  12. Magnetic Thermal Ablation Using Ferrofluids: Influence of Administration Mode on Biological Effect in Different Porcine Tissues

    Bruners, Philipp; Hodenius, Michael; Baumann, Martin; Oversohl, Jessica; Guenther, Rolf W.; Schmitz-Rode, Thomas; Mahnken, Andreas H.

    2008-01-01

    The purpose of this study was to compare the effects of magnetic thermal ablation in different porcine tissues using either a singular injection or a continuous infusion of superparamagnetic iron oxide nanoparticles. In the first setting samples of three ferrofluids containing different amounts of iron (1:171, 2:192, and 3:214 mg/ml) were singularly interstitially injected into specimens of porcine liver, kidney, and muscle (n = 5). Then the specimens were exposed to an alternating magnetic field (2.86 kA/m, 190 kHz) generated by a circular coil for 5 min. In the second experimental setup ferrofluid samples were continuously interstitially infused into the tissue specimens during the exposure to the magnetic field. To measure the temperature increase two fiber-optic temperature probes with a fixed distance of 0.5 cm were inserted into the specimens along the puncture tract of the injection needle and the temperature was measured every 15 s. Finally, the specimens were dissected, the diameters of the created thermal lesions were measured, and the volumes were calculated and compared. Compared to continuous infusion, a single injection of ferrofluids resulted in smaller coagulation volumes in all tissues. Significant differences regarding coagulation volume were found in kidney and muscle specimens. The continuous infusion technique led to more elliptically shaped coagulation volumes due to larger diameters along the puncture tract. Our data show the feasibility of magnetic thermal ablation using either a single interstitial injection or continuous infusion for therapy of lesions in muscle, kidney, and liver. Continuous infusion of ferrofluids results in larger zones of necrosis compared to a single injection technique.

  13. Synthesis of ferrofluids based on cobalt ferrite nanoparticles: Influence of reaction time on structural, morphological and magnetic properties

    Amirabadizadeh, Ahmad; Salighe, Zohre; Sarhaddi, Reza, E-mail: reza.sarhaddi@birjand.ac.ir; Lotfollahi, Zahra

    2017-07-15

    Highlights: • Ferrofluids based on cobalt ferrite nanoparticles were synthesized by co-precipitation method. • The crystallite and particle size of cobalt ferrite can be controlled effectively by reaction time. • The ferrofluids have lower values of saturation magnetization and coercivity as compared to nanoparticles. • By increasing the size of nanoparticles, the narrower and sharper spikes of ferrofluids are formed. - Abstract: In this work, for first time the ferrofluids based on the cobalt ferrite (CoFe{sub 2}O{sub 4}) nanoparticles were prepared by the co-precipitation method at different reaction times (0.5–6.5 h). Crystal structure, morphology and magnetic properties of the cobalt ferrite nanoparticles and the ferrofluids based on the nanoparticles were studied by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM). The XRD patterns of CoFe{sub 2}O{sub 4} nanoparticles synthesized at different reaction times indicated that all samples are single phase in accordance with inverse cubic spinel structure with space group Fd-3m, and no impurity phase was observed. By increasing the reaction time to 3.5 h, the lattice parameter and the average crystallites size increased and then afterwards decreased by increasing the reaction time. The microscopic studies indicated the formation of nanosized particles with nearly spherical in shape, whereas the average particle size for all samples is found to be less than 50 nm. The results of VSM also showed that the saturation magnetization and coercivity field of the cobalt ferrite nanoparticles and the ferrofluids were influenced by reaction time, whereas the ferrofluids have lower values of magnetic parameters than that of nanoparticles.

  14. Moisture and drug solid-state monitoring during a continuous drying process using empirical and mass balance models

    Fonteyne, Margot; Gildemyn, Delphine; Peeters, Elisabeth

    2014-01-01

    of Process Analytical Technology (PAT) tools (Raman and NIR spectroscopy) and a mass balance approach. The six-segmented fluid bed drying system being part of a fully continuous from-powder-to-tablet production line (ConsiGma™-25) was used for this study. A theophylline:lactose:PVP (30:67.5:2.5) blend......, the different size fractions of the dried granules obtained during different experiments (fines, yield and oversized granules) were compared separately, revealing differences in both solid state of theophylline and moisture content between the different granule size fractions. © 2014 Elsevier B.V. All rights...... reserved...

  15. Carbon behavior in the cyclic operation of dry desulfurization process for oxy-fuel integrated gasification combined cycle power generation

    Kobayashi, Makoto; Akiho, Hiroyuki

    2016-01-01

    Highlights: • Power plant with semi-closed gas turbine and O_2–CO_2 coal gasifier was studied. • Dry gas sulfur removal sorbent was improved for durability to carbon deposition. • The improved sorbent showed very low amount of deposited carbon during operation. • The sorbent is regenerable to be used repeatedly in the cyclic operation. • The sorbent exhibited high sulfur-removal performance in the cyclic operation. - Abstract: The dry sulfur-removal process is essential to provide suitable syngas treatment for the oxy-fuel integrated gasification combined cycle power generation plant. It is required that the dry sulfur-removal process to be durable to the carbon deposition due to syngas containing high concentration of carbon monoxide in addition to achieve sufficient performance for sulfur removal. Zinc ferrite sorbent is the most promising candidate for the dry sulfur-removal process. The sorbent was improved to enhance durability to the carbon deposition by modifying preparation. The improved sorbent was prepared from sulfates as the raw materials of zinc ferrite, while the former sorbent was using nitrates as the raw materials. The improved sorbent as well as the former sorbent were evaluated on the performance and carbon deposition tendency in oxy-fuel syngas condition in a fixed bed reactor at elevated pressure and temperature. The results expressed that the improved sorbent has higher desulfurization performance and durability to carbon deposition in the condition expected for cyclic operation of the sulfur-removal process in comparison with the former sorbent. The improved sorbent possessed the superior desulfurization performance as well as the capability for inhibit carbon deposition in the oxy-fuel syngas conditions. The results confirmed the enhanced feasibility of the dry sulfur-removal process by utilizing the improved sorbent.

  16. Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet.

    Zhou, Yilong; Kumar, Dhileep Thanjavur; Lu, Xinyu; Kale, Akshay; DuBose, John; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

    2015-07-01

    Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles.

  17. Deformation of ferrofluid marbles in the presence of a permanent magnet.

    Nguyen, Nam-Trung

    2013-11-12

    This paper investigates the deformation of ferrofluid marbles in the presence of a permanent magnet. Ferrofluid marbles are formed using a water-based ferrofluid and 1 μm hydrophobic polytetrafluoride particles. A marble placed on a Teflon coated glass plate deforms under gravity. In the presence of a permanent magnet, the marble is further deformed with a larger contact area. The geometric parameters are normalized by the radius of an undistorted spherical marble. The paper first discusses a scaling relationship between the dimensionless radius of the contact area as well as the dimensionless height and the magnetic Bond number. The dimensionless contact radius is proportional to the fourth root of the magnetic bond number. The dimensionless height scales with the inverse square root of the magnetic Bond number. In the case of a moving marble dragged by a permanent magnet, the deformation is evaluated as the difference between advancing and receding curvatures of the top view. The dimensionless height and the contact diameter of the marble do not significantly depend on the speed or the capillary number. The scaling analysis and experimental data show that the deformation is proportional to the capillary number.

  18. Synthesis of Ferrofluids Made of Iron Oxide Nanoflowers: Interplay between Carrier Fluid and Magnetic Properties

    Federico Spizzo

    2017-11-01

    Full Text Available Ferrofluids are nanomaterials consisting of magnetic nanoparticles that are dispersed in a carrier fluid. Their physical properties, and hence their field of application are determined by intertwined compositional, structural, and magnetic characteristics, including interparticle magnetic interactions. Magnetic nanoparticles were prepared by thermal decomposition of iron(III chloride hexahydrate (FeCl3·6H2O in 2-pyrrolidone, and were then dispersed in two different fluids, water and polyethylene glycol 400 (PEG. A number of experimental techniques (especially, transmission electron microscopy, Mössbauer spectroscopy and superconducting quantum interference device (SQUID magnetometry were employed to study both the as-prepared nanoparticles and the ferrofluids. We show that, with the adopted synthesis parameters of temperature and FeCl3 relative concentration, nanoparticles are obtained that mainly consist of maghemite and present a high degree of structural disorder and strong spin canting, resulting in a low saturation magnetization (~45 emu/g. A remarkable feature is that the nanoparticles, ultimately due to the presence of 2-pyrrolidone at their surface, are arranged in nanoflower-shape structures, which are substantially stable in water and tend to disaggregate in PEG. The different arrangement of the nanoparticles in the two fluids implies a different strength of dipolar magnetic interactions, as revealed by the analysis of their magnetothermal behavior. The comparison between the magnetic heating capacities of the two ferrofluids demonstrates the possibility of tailoring the performances of the produced nanoparticles by exploiting the interplay with the carrier fluid.

  19. Potential of enhancing a natural convection loop with a thermomagnetically pumped ferrofluid

    Aursand, Eskil; Gjennestad, Magnus Aa.; Lervåg, Karl Yngve, E-mail: karl.lervag@sintef.no; Lund, Halvor

    2016-11-01

    The feasibility of using a thermomagnetically pumped ferrofluid to enhance the performance of a natural convection cooling loop is investigated. First, a simplified analytical estimate for the thermomagnetic pumping action is derived, and then design rules for optimal solenoid and ferrofluid are presented. The design rules are used to set up a medium-scale (1 m, 10–1000 W) case study, which is modeled using a previously published and validated model (Aursand et al. [1]). The results show that the thermomagnetic driving force is significant compared to the natural convection driving force, and may in some cases greatly surpass it. The results also indicate that cooling performance can be increased by factors up to 4 and 2 in the single-phase and two-phase regimes, respectively, even when taking into the account the added heat from the solenoid. The performance increases can alternatively be used to obtain a reduction in heat-sink size by up to 75%. - Highlights: • We consider a thermomagnetically pumped ferrofluid for heat transfer. • The performance of the thermomagnetic pump is compared to natural convection. • The flow is simulated using a two-phase flow model. • The thermomagnetic driving force improves heat transfer significantly.

  20. Measuring the magnetization of nano ferro-fluid with D.C electromagnetic application.

    Ho, Je-Ee; Young, Hong T

    2009-07-01

    A new electromagnetic measuring technology of smaller size, simple structure and high efficiency was proposed in this study. Based on the ferrohydrodynamics (FHD) theory with the absence of viscous effect, the device, independent to the geometry of electro-magnetism, was set up to determine the magnetization of ferrofluid containing magnetite microcrystals of 10 approximately 100 nm size. To strengthen the magnetic intensity, a soft iron was placed across the solenoid of about 2,800 turns, and operated at a DC voltage of 10 V approximately 30 V. The magnetic intensity in this radial component had been found to be most active at this specific setting, which significantly influenced the hydrodynamics of the ferrofluid. With the rise of the liquid, caused by the action of the radial magnetic field, the permeability ratio of ferrofluid at about 1.32 approximately 1.24 could be successfully estimated by the FHD Bernoulli equation. If compared with the experimental data of 1.27, given by Matsumoto Yushi-Seiyaka Co., the relative errors are no more than 5%.

  1. Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet

    Zhou, Yilong; Kumar, Dhileep Thanjavur; Lu, Xinyu; Kale, Akshay; DuBose, John; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

    2015-01-01

    Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles. PMID:26221197

  2. Non-linear dynamics and alternating 'flip' solutions in ferrofluidic Taylor-Couette flow

    Altmeyer, Sebastian

    2018-04-01

    This study treats with the influence of a symmetry-breaking transversal magnetic field on the nonlinear dynamics of ferrofluidic Taylor-Couette flow - flow confined between two concentric independently rotating cylinders. We detected alternating 'flip' solutions which are flow states featuring typical characteristics of slow-fast-dynamics in dynamical systems. The flip corresponds to a temporal change in the axial wavenumber and we find them to appear either as pure 2-fold axisymmetric (due to the symmetry-breaking nature of the applied transversal magnetic field) or involving non-axisymmetric, helical modes in its interim solution. The latter ones show features of typical ribbon solutions. In any case the flip solutions have a preferential first axial wavenumber which corresponds to the more stable state (slow dynamics) and second axial wavenumber, corresponding to the short appearing more unstable state (fast dynamics). However, in both cases the flip time grows exponential with increasing the magnetic field strength before the flip solutions, living on 2-tori invariant manifolds, cease to exist, with lifetime going to infinity. Further we show that ferrofluidic flow turbulence differ from the classical, ordinary (usually at high Reynolds number) turbulence. The applied magnetic field hinders the free motion of ferrofluid partials and therefore smoothen typical turbulent quantities and features so that speaking of mildly chaotic dynamics seems to be a more appropriate expression for the observed motion.

  3. Initial evaluation of dry storage issues for spent nuclear fuels in wet storage at the Idaho Chemical Processing Plant

    Guenther, R J; Johnson, Jr, A B; Lund, A L; Gilbert, E R [and others

    1996-07-01

    The Pacific Northwest Laboratory has evaluated the basis for moving selected spent nuclear fuels in the CPP-603 and CPP-666 storage pools at the Idaho Chemical Processing Plant from wet to dry interim storage. This work is being conducted for the Lockheed Idaho Technologies Company as part of the effort to determine appropriate conditioning and dry storage requirements for these fuels. These spent fuels are from 22 test reactors and include elements clad with aluminum or stainless steel and a wide variety of fuel materials: UAl{sub x}, UAl{sub x}-Al and U{sub 3}O{sub 8}-Al cermets, U-5% fissium, UMo, UZrH{sub x}, UErZrH, UO{sub 2}-stainless steel cermet, and U{sub 3}O{sub 8}-stainless steel cermet. The study also included declad uranium-zirconium hydride spent fuel stored in the CPP-603 storage pools. The current condition and potential failure mechanisms for these spent fuels were evaluated to determine the impact on conditioning and dry storage requirements. Initial recommendations for conditioning and dry storage requirements are made based on the potential degradation mechanisms and their impacts on moving the spent fuel from wet to dry storage. Areas needing further evaluation are identified.

  4. Initial evaluation of dry storage issues for spent nuclear fuels in wet storage at the Idaho Chemical Processing Plant

    Guenther, R.J.; Johnson, A.B. Jr.; Lund, A.L.; Gilbert, E.R.

    1994-11-01

    The Pacific Northwest Laboratory has evaluated the basis for moving selected spent nuclear fuels in the CPP-603 and CPP-666 storage pools at the Idaho Chemical Processing Plant from wet to dry interim storage. This work is being conducted for the Lockheed Idaho Technologies Company as part of the effort to determine appropriate conditioning and dry storage requirements for these fuels. These spent fuels are from 22 test reactors and include elements clad with aluminum or stainless steel and a wide variety of fuel materials: UAl x , UAl x -Al and U 3 O 8 -Al cermets, U-5% fissium, UMo, UZrH x , UErZrH, UO 2 -stainless steel cermet, and U 3 O 8 -stainless steel cermet. The study also included declad uranium-zirconium hydride spent fuel stored in the CPP-603 storage pools. The current condition and potential failure mechanisms for these spent fuels were evaluated to determine the impact on conditioning and dry storage requirements. Initial recommendations for conditioning and dry storage requirements are made based on the potential degradation mechanisms and their impacts on moving the spent fuel from wet to dry storage. Areas needing further evaluation are identified

  5. Critical solvent properties affecting the particle formation process and characteristics of celecoxib-loaded plga microparticles via spray-drying.

    Wan, Feng; Bohr, Adam; Maltesen, Morten Jonas; Bjerregaard, Simon; Foged, Camilla; Rantanen, Jukka; Yang, Mingshi

    2013-04-01

    It is imperative to understand the particle formation mechanisms when designing advanced nano/microparticulate drug delivery systems. We investigated how the solvent power and volatility influence the texture and surface chemistry of celecoxib-loaded poly (lactic-co-glycolic acid) (PLGA) microparticles prepared by spray-drying. Binary mixtures of acetone and methanol at different molar ratios were applied to dissolve celecoxib and PLGA prior to spray-drying. The resulting microparticles were characterized with respect to morphology, texture, surface chemistry, solid state properties and drug release profile. The evaporation profiles of the feed solutions were investigated using thermogravimetric analysis (TGA). Spherical PLGA microparticles were obtained, irrespectively of the solvent composition. The particle size and surface chemistry were highly dependent on the solvent power of the feed solution. An obvious burst release was observed for the microparticles prepared by the feed solutions with the highest amount of poor solvent for PLGA. TGA analysis revealed distinct drying kinetics for the binary mixtures. The particle formation process is mainly governed by the PLGA precipitation rate, which is solvent-dependent, and the migration rate of celecoxib molecules during drying. The texture and surface chemistry of the spray-dried PLGA microparticles can therefore be tailored by adjusting the solvent composition.

  6. Monitoring of multiple solvent induced form changes during high shear wet granulation and drying processes using online Raman spectroscopy.

    Reddy, Jay Poorna; Jones, John W; Wray, Patrick S; Dennis, Andrew B; Brown, Jonathan; Timmins, Peter

    2018-04-25

    Form changes during drug product processing can be a risk to the final product quality in terms of chemical stability and bioavailability. In this study, online Raman spectroscopy was used to monitor the form changes in real time during high shear wet granulation of Compound A, a highly soluble drug present at a high drug load in an extended release formulation. The effect of water content, temperature, wet massing time and drying technique on the degree of drug transformation were examined. A designed set of calibration standards were employed to develop quantitative partial least square regression models to predict the concentration of each drug form during both wet granulation and the drying process. Throughout all our experiments we observed complex changes of the drug form during granulation, manifest as conversions between the initial non-solvated form of Compound A, the hemi-hydrate form and the "apparent" amorphous form (dissolved drug). The online Raman data demonstrate that the non-solvated form converts to an "apparent" amorphous form (dissolved drug) due to drug dissolution with no appearance of the hemi-hydrate form during water addition stage. The extent of conversion of the non-solvated form was governed by the amount of water added and the rate of conversion was accelerated at higher temperatures. Interestingly, in the wet massing zone, the formation of the hemi-hydrate form was observed at a rate equivalent to the rate of depletion of the non-solvated form with no change in the level of the "apparent amorphous" form generated. The level of hemi-hydrate increased with an increase in wet massing time. The drying process had a significant effect on the proportion of each form. During tray drying, changes in drug form continued for hours. In contrast fluid bed drying appeared to lock the final proportions of drug form product attained during granulation, with comparatively small changes observed during drying. In conclusion, it was possible to

  7. Drying process optimization for an API solvate using heat transfer model of an agitated filter dryer.

    Nere, Nandkishor K; Allen, Kimberley C; Marek, James C; Bordawekar, Shailendra V

    2012-10-01

    Drying an early stage active pharmaceutical ingredient candidate required excessively long cycle times in a pilot plant agitated filter dryer. The key to faster drying is to ensure sufficient heat transfer and minimize mass transfer limitations. Designing the right mixing protocol is of utmost importance to achieve efficient heat transfer. To this order, a composite model was developed for the removal of bound solvent that incorporates models for heat transfer and desolvation kinetics. The proposed heat transfer model differs from previously reported models in two respects: it accounts for the effects of a gas gap between the vessel wall and solids on the overall heat transfer coefficient, and headspace pressure on the mean free path length of the inert gas and thereby on the heat transfer between the vessel wall and the first layer of solids. A computational methodology was developed incorporating the effects of mixing and headspace pressure to simulate the drying profile using a modified model framework within the Dynochem software. A dryer operational protocol was designed based on the desolvation kinetics, thermal stability studies of wet and dry cake, and the understanding gained through model simulations, resulting in a multifold reduction in drying time. Copyright © 2012 Wiley-Liss, Inc.

  8. Impact analysis of different chemical pre-treatments on colour of apple discs during drying process

    Jasmina Lukinac

    2009-01-01

    Full Text Available The main purpose of this study was to compare colour changes of chemically pre-treated dried apple discs. Changes were observed by chromameter in L*a*b* colour model by using Minolta chromameter CR-400 and by image analysis system in RGB colour model. Apple discs variety "Gold Rush" were pre-treated and dried in laboratory tray drier at drying temperature 70 °C and at airflow velocity of 1.5 ms-1. Different chemical pre-treatments were applied on apple discs (dipping in 0.5% ascorbic acid solution; 0.3% L–cysteine solution; 0.1% 4–hexyl resorcinol solution and 1% sodium metabisulphite solution. Mean values of colour parameters, colour changes and correlation coefficients for apple discs were calculated for both colour models. The analysis showed statistically significant influence of pre-treatment method on total colour changes for both chosen colour models of dried apples. Calculated correlation coefficient between colour changes for used models was found to be 0.894. According to colour characteristics the best results were achieved when samples were pre-treated with 0.5% ascorbic acid solution. According to calculated results it was found that image analysis method as well as colorimetric method can be used to observe the colour changes on dried apple discs.

  9. Effect of Physical Osmosis Methods on Quality of Tilapia Fillets Processed by Heat Pump Drying

    Li Min

    2017-06-01

    Full Text Available In order to achieve the influence of different pretreatment methods on heat pump dried tilapia fillets, the effects of trehalose, ultrasound-assisted and freeze-thaw cycle assisted osmotic dehydration on the color, rehydration, texture and Ca2+-ATPase activity were investigated. Tilapia fillets (100 mm length × 50 mm width × 5 mm height were first osmoconcentrated in a trehalose solution combined with 4°C under atmospheric pressure for 1 h, different power of ultrasound and freeze-thawing respectively, then heat pump dried. The results showed that under the same drying method, the comprehensive score of ultrasound in 400 Watt was best, compared to freeze-thaw, the ultrasound pretreatment had a significant (p0.05 effect on the rehydration and texture. However, both of them significantly (p<0.05 affected the quality in comparison to that of osmosis at 4°C. It indicates that suitable ultrasonic pretreatment conditions improve the quality of dried products effectively and the conclusion of this research provides reference for heat pump dried similar products.

  10. Evaluation of a dry process for conversion of U-AVLIS product to UF{sub 6}. Milestone U361

    NONE

    1992-05-01

    A technical and engineering evaluation has been completed for a dry UF{sub 6} production system to convert the product of an initial two-line U-AVLIS plant. The objective of the study has been to develop a better understanding of process design requirements, capital and operating costs, and demonstration requirements for this alternate process. This report summarizes the results of the study and presents various comparisons between the baseline and alternate processes, building on the information contained in UF{sub 6} Product Alternatives Review Committee -- Final Report. It also provides additional information on flowsheet variations for the dry route which may warrant further consideration. The information developed by this study and conceptual design information for the baseline process will be combined with information to be developed by the U-AVLIS program and by industrial participants over the next twelve months to permit a further comparison of the baseline and alternate processes in terms of cost, risk, and compatibility with U-AVLIS deployment schedules and strategies. This comparative information will be used to make a final process flowsheet selection for the initial U-AVLIS plant by March 1993. The process studied is the alternate UF{sub 6} production flowsheet. Process steps are (1) electron-beam distillation to reduce enriched product iron content from about 10 wt % or less, (2) hydrofluorination of the metal to UF{sub 4}, (3) fluorination of UF{sub 4} to UF{sub 6}, (4) cold trap collection of the UF{sub 6} product, (5) UF{sub 6} purification by distillation, and (6) final blending and packaging of the purified UF{sub 6} in cylinders. A preliminary system design has been prepared for the dry UF{sub 6} production process based on currently available technical information. For some process steps, such information is quite limited. Comparisons have been made between this alternate process and the baseline plant process for UF{sub 6} production.

  11. Evaluation of a dry process for conversion of U-AVLIS product to UF6. Milestone U361

    1992-05-01

    A technical and engineering evaluation has been completed for a dry UF 6 production system to convert the product of an initial two-line U-AVLIS plant. The objective of the study has been to develop a better understanding of process design requirements, capital and operating costs, and demonstration requirements for this alternate process. This report summarizes the results of the study and presents various comparisons between the baseline and alternate processes, building on the information contained in UF 6 Product Alternatives Review Committee -- Final Report. It also provides additional information on flowsheet variations for the dry route which may warrant further consideration. The information developed by this study and conceptual design information for the baseline process will be combined with information to be developed by the U-AVLIS program and by industrial participants over the next twelve months to permit a further comparison of the baseline and alternate processes in terms of cost, risk, and compatibility with U-AVLIS deployment schedules and strategies. This comparative information will be used to make a final process flowsheet selection for the initial U-AVLIS plant by March 1993. The process studied is the alternate UF 6 production flowsheet. Process steps are (1) electron-beam distillation to reduce enriched product iron content from about 10 wt % or less, (2) hydrofluorination of the metal to UF 4 , (3) fluorination of UF 4 to UF 6 , (4) cold trap collection of the UF 6 product, (5) UF 6 purification by distillation, and (6) final blending and packaging of the purified UF 6 in cylinders. A preliminary system design has been prepared for the dry UF 6 production process based on currently available technical information. For some process steps, such information is quite limited. Comparisons have been made between this alternate process and the baseline plant process for UF 6 production

  12. Heat transfer fouling characteristics of microfiltered thin stillage from the dry grind process.

    Arora, Amit; Dien, Bruce S; Belyea, Ronald L; Singh, Vijay; Tumbleson, M E; Rausch, Kent D

    2010-08-01

    We investigated effects of microfiltration (MF) on heat transfer fouling tendencies of thin stillage. A stainless steel MF membrane (0.1 micron pore size) was used to remove solids from thin stillage. At filtration conditions of 690kPa, the MF process effectively recovered total solids from thin stillage. Thin stillage was concentrated from 7.0% to 22.4% solids with average permeate flux rates of 180+/-30 L/m(2)/h at 75 degrees C. In retentate streams, protein and fat contents were increased from 23.5 and 16.7% db to 27.6 and 31.1% db, respectively, and ash content was reduced from 10.5% to 3.8% db. Removal of solids, protein and fat generated a microfiltration permeate (MFP) that was used as an input stream to the fouling probe system; MFP fouling tendencies were measured. An annular fouling probe was used to measure fouling tendencies of thin stillage from a commercial dry grind facility. When comparing diluted thin stillage (DTS) stream and MFP, a reduction in solids concentration was not the only reason of fouling decrement. Selective removal of protein and fat played an important role in mitigating the fouling. At t=10h, mean fouling rates of MFP were an order of magnitude lower when compared to thin stillage and diluted streams. When maximum probe temperature (200 degrees C) was reached, mean fouling rates for thin stillage, DTS and MFP were 7.1x10(-4), 4.2x10(-4) and 2.6x10(-4) m(2) degrees C/kW/min, respectively. In DTS and MFP, the induction period was prolonged by factors of 4.3 and 9.5, respectively, compared to the induction period for thin stillage fouling. Mean fouling rates were decreased by factors of 2.3 and 23.4 for DTS and MFP, respectively. Fouling of MFP took twice the time to reach a probe temperature of 200 degrees C than did thin stillage (22 h vs 10 h, respectively). A reduction in heat transfer fouling could be achieved by altering process stream composition using microfiltration. Copyright 2010 Elsevier Ltd. All rights reserved.

  13. Extinction of polarized light in ferrofluids with different magnetic particle concentrations

    Socoliuc, V.; Popescu, L.B.

    2012-01-01

    The magnetic field intensity and nanoparticle concentration dependence of the polarized light extinction in a ferrofluid made of magnetite particles stabilized with technical grade oleic acid dispersed in transformer oil was experimentally investigated. The magnetically induced optical anisotropy, i.e. the dichroism divided by concentration, was found to decrease with increasing sample concentration from 2% to 8%. The magnetically induced change in the optical extinction of light polarized at 54.74 o with respect to the magnetic field direction was found to be positive for the less concentrated sample (2%) and negative for the samples with 4% and 8% magnetic nanoparticle concentrations, the more negative the higher the concentration and field intensity. Based on the theoretically proven fact that the particle orientation mechanism has no effect on the extinction of light polarized at 54.74 o with respect to the field direction, we analyzed the experimental findings in the frames of the agglomeration and long-range pair correlations theories for the magnetically induced optical anisotropy in ferrofluids. We developed a theoretical model in the approximation of single scattering for the optical extinction coefficient of a ferrofluid with magnetically induced particle agglomeration. The model predicts the existence of a polarization independent component of the optical extinction coefficient that is experimentally measurable at 54.74 o polarization angle. The change in the optical extinction of light polarized at 54.74 o is positive if only the formation of straight n-particle chains is considered and may become negative in the hypothesis that the longer chains degenerate to more isotropic structures (polymer-like coils, globules or bundles of chains). The model for the influence on the light absorption of the long-range pair correlations, published elsewhere, predicts that the change in the optical extinction of light polarized at 54.74 o is always negative, the more

  14. A Three-Dimensional Pore-Scale Model for Non-Wetting Phase Mobilization with Ferrofluid

    Wang, N.; Prodanovic, M.

    2017-12-01

    Ferrofluid, a stable dispersion of paramagnetic nanoparticles in water, can generate a distributed pressure difference across the phase interface in an immiscible two-phase flow under an external magnetic field. In water-wet porous media, this non-uniform pressure difference may be used to mobilize the non-wetting phase, e.g. oil, trapped in the pores. Previous numerical work by Soares et al. of two-dimensional single-pore model showed enhanced non-wetting phase recovery with water-based ferrofluid under certain magnetic field directions and decreased recovery under other directions. However, the magnetic field selectively concentrates in the high magnetic permeability ferrofluid which fills the small corners between the non-wetting phase and the solid wall. The magnetic field induced pressure is proportional to the square of local magnetic field strength and its normal component, and makes a significant impact on the non-wetting phase deformation. The two-dimensional model omitted the effect of most of these corners and is not sufficient to compute the magnetic-field-induced pressure difference or to predict the non-wetting blob deformation. Further, it is not clear that 3D effects on magnetic field in an irregular geometry can be approximated in 2D. We present a three-dimensional immiscible two-phase flow model to simulate the deformation of a non-wetting liquid blob in a single pore filled with a ferrofluid under a uniform external magnetic field. The ferrofluid is modeled as a uniform single phase because the nanoparticles are 104 times smaller than the pore. The open source CFD solver library OpenFOAM is used for the simulations based on the volume of fluid method. Simulations are performed in a converging-diverging channel model on different magnetic field direction, different initial oil saturations, and different pore shapes. Results indicate that the external magnetic field always stretches the non-wetting blob away from the solid channel wall. A magnetic

  15. Influence of predictive contamination to agricultural products due to dry and wet processes during an accidental release of radionuclides

    Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Jeong, Hyo Joon; Han, Moon Hee; Lee, Chang Woo

    2003-01-01

    The influence of predictive contamination to agricultural products due to the wet processes as well as dry processes from radioactive air concentration during a nuclear emergency is comprehensively analyzed. The previous dynamic food chain model DYNACON considering Korean agricultural and environmental conditions, in which the initial input parameter was radionuclide concentrations on the ground, is improved so as to evaluate radioactive contamination to agricultural products from either radioactive air concentrations or radionuclide concentrations on the ground. As for the results, wet deposition is a more dominant mechanism than dry deposition in contamination on the ground. While, the contamination levels of agricultural products are strongly dependent on radionuclide and precipitation when the deposition of radionuclides occurs. It means that the contamination levels of agricultural products are determined from which is the more dominant process between deposition on the ground and interception to agricultural plants

  16. Rewetting of semi-dried ink patterns by vapour annealing for developing a reflow process in reverse offset printing

    Kusaka, Yasuyuki; Ushijima, Hirobumi; Sugihara, Kazuyoshi; Koutake, Masayoshi

    2017-01-01

    A process for reflowing patterned materials for reverse offset printing was developed, with the aim of mitigating the step-coverage problem in multilayered devices. The proposed reflow process involves a single step of vapour annealing at moderate temperatures ranging from 60 to 70 °C. This step successfully changes the height profile of semi-dried ink patterns formed on a silicone blanket, from an initially rectangular shape to a rounded shape. A systematic investigation on the effects of various vapour species and vapour temperatures on the reflow process revealed that the miscibility between the vapour and the ink, and a low boiling point of the respective solvent (high vapour pressure) are the prerequisites for successful reflows of semi-dried ink layers patterned on a silicone blanket. The results suggested that the rewetting of previously semi-dried patterns is the main mechanism in the reflow process, which led to a change in the height profile. Furthermore, the reflowed patterns demonstrated almost identical peak-height thicknesses, irrespective of the width of the patterns. This is a unique property that is unattainable by other printing methods, including gravure offset printing and microcontact printing, wherein printed patterns have rounded shapes without a reflow process, but their thickness inevitably depends on the pattern sizes. (technical note)

  17. Preparation of dry ports for a competitive environment in the container seaport system: A process benchmarking approach

    J. Jeevan

    2017-06-01

    Full Text Available The significant exodus of containers inland due to the container revolution has increased the salience of inland terminals for efficient freight distribution. Further, the migration of containers gradually inland has forced seaports to depend on these inland terminals to determine their competitiveness and offer a mechanism for competitive freight price to the consumer. The performance of dry ports need to be improved along with the dynamic nature of maritime business, to efficiently fulfil the demand all the key players in the container seaport system, provide economies of scale and scope to their respective clients and enhances the importance of inland networks to improve and consistently elongate the competitiveness of container seaports. Predicated to these importance, this paper aims to enhance dry port performance by adapting a process benchmarking strategy among the Malaysian dry ports. Prior to the adaptation of the process benchmarking approach, a grounded theory had been conducted as a method of analysis among the key players of the Malaysian container seaport system in order to provide essential inputs for the benchmarking. Through this paper, the outcome shows all four Malaysian dry ports need to improve their transportation infrastructure and operation facilities, container planning strategy, competition, location and externalities in order to assist all the key players in the container seaport system efficiently and effectively.

  18. Effect of Sol Concentration, Aging and Drying Process on Cerium Stabilization Zirconium Gel Produced by External Gelation

    Sukarsono, R.; Rachmawati, M.; Susilowati, S. R.; Husnurrofiq, D.; Nurwidyaningrum, K.; Dewi, A. K.

    2018-02-01

    Cerium Stabilized Zirconium gel has been prepared using external gelation process. As the raw materials was used ZrO(NO3)2 and Ce(NO3)4 nitrate salt which was dissolved with water into Zr-Ce nitrate mixture. The concentration of the nitrate salt mixture in the sol solution was varied by varying the concentration of zirconium and cerium nitrate in the sol solution and the addition of PVA and THFA to produce a sol with a viscosity of 40-60 cP. The viscosity range of 40-60cP is the viscosity of the sol solution that was easy to produce a good gel in the gelation apparatus. Sol solution was casted in a gelation column equipped with following tools: a 1 mm diameter drip nozzle which was vibrated to adjust the best frequency and amplitude of vibration, a flow meter to measure the flow rate of sol, flowing of NH3 gas to presolidification process. Gelation column was contained NH4OH solution as gelation medium and gel container to collect gel product. Gel obtained from the gelation process than processed with ageing, washing, drying and calcinations to get round gel and not broken at calcinations up to 500°C. The parameters observed in this research are variation of Zr nitrate concentration, Ce nitrate concentration, ratio of Zr and Ce in the sol and ageing and drying process method which was appropriate to get a good gel. From the gelation processes that has been done, it can be seen that with the presolidification process can be obtained a round gel and without presolidification process, produce not round gel. In the process of ageing to get not broken gel, ageing was done on the rotary flask so that during the ageing, gels rotate in gelation media. Gels, then be washed by dilute ammonium nitrate, demireralized water and iso prophyl alcohol. The washed gel was then dried by vacuum drying to form pores on the gel which become the path for the gases resulting from decomposition of the gel to exit the gel. Vacuum drying can prevent cracking because the pores allow the gel

  19. Mineralogy of Antarctica Dry Valley Soils: Implications for Pedogenic Processes on Mars

    Quinn, J. E.; Ming, D. W.; Morris, R. V.; Douglas, S.; Kounaves, S. P.; McKay, C. P.; Tamppari, L, K.; Smith, P. H.; Zent, A. P.; Archer, P. D., Jr.

    2010-01-01

    The Antarctic Dry Valleys (ADVs) located in the Transantarctic Mountains are the coldest and driest locations on Earth. The mean annual air temperature is -20 C or less and the ADVs receive 100mm or less of precipitation annually in the form of snow. The cold and dry climate in the ADVs is one of the best terrestrial analogs for the climatic conditions on Mars [2]. The soils in the ADVs have been categorized into three soil moisture zones: subxerous, xerous and ultraxerous. The subxerous zone is a coastal region in which soils have ice-cemented permafrost relatively close to the surface. Moisture is available in relatively large amounts and soil temperatures are above freezing throughout the soil profile (above ice permafrost) in summer months. The xerous zone, the most widespread of the three zones, is an inland region with a climate midway between the subxerous and ultraxerous. The soils from this zone have dry permafrost at moderate depths (30-75cm) but have sufficient water in the upper soil horizons to allow leaching of soluble materials. The ultraxerous zone is a high elevation zone, where both temperature and precipitation amounts are very low resulting in dry permafrost throughout the soil profile. The three moisture regime regions are similar to the three microclimatic zones (coastal thaw, inland mixed, stable upland) defined by Marchant and Head.

  20. Preparation of interconnected highly porous polymeric structures by a replication and freeze-drying process

    Hou, Q.; Grijpma, Dirk W.; Feijen, Jan

    2003-01-01

    Three-dimensional degradable porous polymeric structures with high porosities (93-98%) and well-interconnected pore networks have been prepared by freeze-drying polymer solutions in the presence of a leachable template followed by leaching of the template. Templates of the pore network were prepared

  1. Experimental Research of Moisture Evaporation Process from Biomass in a Drying Chamber

    Bulba E.E.

    2015-01-01

    Full Text Available Presented mass evaporation rate hardwood (birch, aspen, maple, poplar derived from experimental studies. The dependence of temperature on evaporation mass rate and calculated the accommodation coefficient for the respective temperature ranges are obtained. Analyzed the temperature of drying conditions relevant species hardwood.

  2. Advanced exergoeconomic analysis of a gas engine heat pump (GEHP) for food drying processes

    Gungor, Aysegul; Tsatsaronis, George; Gunerhan, Huseyin; Hepbasli, Arif

    2015-01-01

    Highlights: • Comparison between conventional and advanced exergoconomic analyses for food drying. • 74% of the total energy destruction can be avoided. • The condenser has the highest improvement potential. • Inefficiencies and options for improvement are identified for each component. - Abstract: Exergetic and exergoeconomic analyses are often used to evaluate the performance of energy systems from the thermodynamic and economic points of view. While a conventional exergetic analysis can be used to recognize the sources of inefficiencies, the so-called advanced exergy-based analysis is convenient for identifying the real potential for thermodynamic improvements and the system component interactions by splitting the exergy destruction and the total operating cost within each component into endogenous/exogenous and unavoidable/avoidable parts. In this study for the first time an advanced exergoeconomic analysis is applied to a gas-engine-driven heat pump (GEHP) drying system used in food drying for evaluating its performance along with each component. The advanced exergoeconomic analysis shows that the unavoidable part of the exergy destruction cost rate within the components of the system is lower than the avoidable part. The most important components based on the total avoidable costs are drying ducts, the condenser and the expansion valve. The inefficiencies within the condenser could particularly be improved by structural improvements of the whole system and the remaining system components. Finally, it can be concluded that the internal design changes play a more essential role in determining the cost of each component

  3. Predictive modeling of infrared radiative heating in tomato dry-peeling process: Part I. Model development

    Infrared (IR) dry-peeling has emerged as an effective non-chemical alternative to conventional lye and steam methods of peeling tomatoes. Successful peel separation induced by IR radiation requires the delivery of a sufficient amount of thermal energy onto tomato surface in a very short duration. Th...

  4. A double stage dry-wet-fermentation process for a fast and safe digestion of different kinds of organic material

    Busch, G.; Sieber, M.; Buschmann, J.; Burkhardat, M.

    2009-01-01

    The fermentation of organic material is a four-step-process. It is admissible to merge the first two steps (hydrolysis and acidification) to hydrolysis in general and the last two steps (aceto genesis and methano genesis) to methano genesis. The Brandenburg University of Technology in Cottbus has devised a double stage dry-wet-fermentation process for fast and safe anaerobic degradation. Using these processes, it is possible to decompose different kinds of organic material like renewable material (e. g. maize silage), waste (e. g. household-waste) and industrial material (e. g. glycerine). (Author)

  5. Influence of radioactive contamination to agricultural products due to dry and wet deposition processes during a nuclear emergency

    Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Han, Moon Hee; Choi, Yong Ho; Lee, Chang Woo

    2002-01-01

    Combined with deposition model onto the ground of radionuclides, the influence of radioactive contamination to agricultural products was analyzed due to wet deposition as well as dry deposition from radioactive air concentration during a nuclear emergency. The previous dynamic food chain model, in which initial input parameter is only radionuclide concentrations on the ground, was improved for the evaluating of radioactive contamination to agricultural products from either radionuclide concentrations in air or radionuclide concentrations on the ground. As the results, in case of deposition onto the ground, wet deposition was more dominant process than dry deposition. While the contamination levels of agricultural products were dependent on the a variety of factors such as radionuclides and rainfall rate. It means that the contamination levels of agricultural products are determined from which is more dominant process between deposition on the ground and interception onto agricultural plants

  6. Effect of processing history on the surface interfacial properties of budesonide in carrier-based dry-powder inhalers.

    Shur, Jagdeep; Pitchayajittipong, Chonladda; Rogueda, Philippe; Price, Robert

    2013-08-01

    Influence of air-jet micronization, post-micronization conditioning and storage on the surface properties of budesonide in dry-powder inhaler formulations was investigated. Crystalline budesonide was air jet-micronized and conditioned using organic vapor. Particle engineering was also used to fabricate respirable particles of budesonide. Surface imaging by atomic force microscopy suggested that micronized material possessed process-induced surface disorder, which relaxed upon conditioning with organic vapor. Particle engineered material was devoid of such surface disorder. Surface interfacial properties of all batches were different and correlated to in vitro fine particle delivery. The surface properties and in vitro performance of the conditioned material changed upon storage of the budesonide at 44% relative humidity and 25°C, while the micronized and particle-engineered material remained stable. These data suggest that processing conditions of budesonide affected the surface properties of the material, which was demonstrated to have direct affect on dry-powder inhaler formulation performance.

  7. Synthesis and electrochemical characteristics of spinel LiMn2O4 via a precipitation spray-drying process

    Wu, H.M.; Tu, J.P.; Yuan, Y.F.; Li, Y.; Zhao, X.B.; Cao, G.S.

    2005-01-01

    Spinel LiMn 2 O 4 has been successfully synthesized using a precipitation spray-drying process. After the precursor was annealed at 750 deg. C for 10 h, the synthesized material was well-crystallized spinel particle, and exhibited uniform particle size distribution. From cyclic voltammetry results, there is an anomalous redox peaks (3.75/3.26 V). In the charge/discharge potential (versus Li) ranging from 3.2 to 4.5 V, it delivered a high initial discharge capacity of 123 mAh/g at a discharge rate of 60 μA/cm 2 (1/4 C rate). At a high discharge rate of 2.4 mA/cm 2 (10 C rate), the obtainable reversible capacity was 79 mAh/g. The simple procedure of precipitation spray-drying process is time and energy saving, and thus is promising for commercial application

  8. Degradation Dynamics and Dietary Risk Assessments of Two Neonicotinoid Insecticides during Lonicera japonica Planting, Drying, and Tea Brewing Processes.

    Fang, Qingkui; Shi, Yanhong; Cao, Haiqun; Tong, Zhou; Xiao, Jinjing; Liao, Min; Wu, Xiangwei; Hua, Rimao

    2017-03-01

    The degradation dynamics and dietary risk assessments of thiamethoxam and thiacloprid during Lonicera japonica planting, drying, and tea brewing processes were systematically investigated using high-performance liquid chromatography. The half-lives of thiamethoxam and thiacloprid were 1.0-4.1 d in the honeysuckle flowers and leaves, with degradation rate constants k ranging from -0.169 to -0.696. The safety interval time was 7 d. The sun- and oven-drying (70 °C) percent digestions were 59.4-81.0% for the residues, which were higher than the shade- and oven-drying percentages at lower temperatures (30, 40, 50, and 60 °C, which ranged from 37.7% to 57.0%). The percent transfers of thiamethoxam and thiacloprid were 0-48.4% and 0-25.2%, respectively, for the different tea brewing conditions. On the basis of the results of this study, abiding by the safety interval time is important, and using reasonable drying methods and tea brewing conditions can reduce the transfer of thiamethoxam and thiacloprid to humans.

  9. Estimating the Energy Content of Wastewater Using Combustion Calorimetry and Different Drying Processes

    Korth, Benjamin; Maskow, Thomas; Günther, Susanne; Harnisch, Falk, E-mail: falk.harnisch@ufz.de [Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research, Leipzig (Germany)

    2017-09-19

    The energy content of wastewater is routinely assessed by chemical oxygen demand (COD) measurements that only provide an incomplete picture and the data fundament of other energy parameters remains scarce. The volumetric heat of combustion (Δ{sub C}H) of raw wastewater from a municipal wastewater treatment plant (WWTP) was assessed using oven drying method (Δ{sub C}H{sub vol} = −6.8 ± 4.3 kJ L{sup −1}, n = 20) and freeze drying method (Δ{sub C}H{sub vol} = −20.2 ± 9.7 kJ L{sup −1}, n = 6) illustrating the substantial loss during the oven drying approach. Normalizing Δ{sub C}H to COD of raw wastewater yielded −6.2 ± 3.5 kJ gCOD{sup −1} for oven-dried samples (n = 14) and −13.0 ± 1.6 kJ gCOD{sup −1} for freeze-dried samples (n = 3). A subsequent correlation analysis with further chemical wastewater parameters revealed a dependency of Δ{sub C}H{sub vol} on COD, total organic carbon (TOC), C:N ratio, and total sulfur content. To verify these correlations, wastewater of a second WWTP was sampled and analyzed. Only COD and TOC were in accordance with the data set from the first WWTP representing potential predictors for the chemical energy stored in wastewater for comparable WWTPs. Unfortunately, during the most practical method (oven drying), a certain loss of volatile compounds is inevitable so that the derived Δ{sub C}H{sub vol} systematically underestimates the total energetic potential of wastewater. Nevertheless, this work expands the, so far, little data fundament on the energy resource wastewater and implies the requirement for further long-term studies on different sites and different wastewater types with a highly standardized sample treatment protocol.

  10. Role of Biotic and Abiotic Processes on Soil CO2 Dynamics in the McMurdo Dry Valleys, Antarctica

    Risk, D. A.; Macintyre, C. M.; Lee, C.; Cary, C.; Shanhun, F.; Almond, P. C.

    2016-12-01

    In the harsh conditions of the Antarctic Dry Valleys, microbial activity has been recorded via measurements of soil carbon dioxide (CO2) concentration and surface efflux. However, high temporal resolution studies in the Dry Valleys have also shown that abiotic solubility-driven processes can strongly influence (and perhaps even dominate) the CO2 dynamics in these low flux environments and suggests that biological activity may be lower than previously thought. In this study, we aim to improve our understanding of CO2 dynamics (biotic and abiotic) in Antarctic Dry Valley soils using long-term automated measurements of soil CO2 surface flux and soil profile concentration at several sites, often at sub-diel frequency. We hypothesize that soil CO2 variations are driven primarily by environmental factors affecting CO2 solubility in soil solution, mainly temperature, and that these processes may even overprint biologic production in representative Dry Valley soils. Monitoring of all sites revealed only one likely biotic CO2 production event, lasting three weeks during the Austral summer and reaching fluxes of 0.4 µmol/m2/s. Under more typical low flux conditions (sampling campaigns. Subsurface CO2 monitoring and a lab-controlled Antarctic soil simulation experiment confirmed that abiotic processes are capable of dominating soil CO2 variability. Diel temperature cycles crossing the freezing boundary revealed a dual abiotic cycle of solubility cycling and gas exclusion from ice formation observed only by high temporal frequency measurements (30 min). This work demonstrates a need for a numerical model to partition the dynamic abiotic processes underlying any biotic CO2 production in order to understand potential climate-change induced increases in microbial productivity in terrestrial Antarctica.

  11. Thermohydraulic modeling of the dry air passive containment cooling system process in the Westinghouse AP-600 ALWR

    Harari, R; Weis, Y; Barnea, Y [Israel Atomic Energy Commission, Beersheba (Israel). Nuclear Research Center-Negev

    1996-12-01

    Following postulated events of a LOCA, the passive Containment Cooling System (PCCS) uses dry air to transfer the residual heat by natural circulation. The air flow path, designed between the steel reactor containment hot shell and the concrete shield building, creates an open thermosyphon. The purpose of this inherently safe process is to assure the long term steady-state cooling of the nuclear core after an emergency shutdown (authors).

  12. Real-time particle size analysis using focused beam reflectance measurement as a process analytical technology tool for a continuous granulation-drying-milling process.

    Kumar, Vijay; Taylor, Michael K; Mehrotra, Amit; Stagner, William C

    2013-06-01

    Focused beam reflectance measurement (FBRM) was used as a process analytical technology tool to perform inline real-time particle size analysis of a proprietary granulation manufactured using a continuous twin-screw granulation-drying-milling process. A significant relationship between D20, D50, and D80 length-weighted chord length and sieve particle size was observed with a p value of 0.05).

  13. Biodegradability of poly(butylene succinate-co-butylene adipate) (PBSA) controlled by temperature during the dried-gel process

    Yamazaki, Hana; Maeda, Tomoki; Hotta, Atsushi

    Currently there is a growing interest in biodegradable plastics that can be readily degraded into H2O and CO2. Among them, poly(butylene succinate-co-butylene adipate)(PBSA) is one of the mechanically attractive materials that can be biodegraded by surrounding water molecules and microorganisms after the disposal of the plastics. In order to expand the use of PBSA, the proper and effective control of the biodegradability of PBSA should be realized. In this work, the dried-gel process of the PBSA was carefully studied considering the temperature of the process. Three different types of dried PBSA gels were prepared at three different gel-process temperatures. From the biodegradability testing by immersing the PBSA samples in NaOH aq., it was found that the percentage of the weight loss of the PBSA was increased, indicating that the biodegradability was enhanced as the gel preparation temperature became lower. In fact, smaller spherocrystals were observed in PBSA dried at cooler temperature, studied by the scanning electron microscopy (SEM). It was therefore concluded that the microstructures of PBSA could be well controlled by changing the gel preparation temperatures for the precise control of the biodegradability of PBSA. This work was supported by a Grant-in-Aid for Scientific Research (A) (No. 15H02298 to A.H.) and a Grant-in-Aid for Research Activity Start-up (No.15H06586 to T.M.) from JSPS: KAKENHI\\x9D.

  14. GaN MOSFET with Boron Trichloride-Based Dry Recess Process

    Jiang, Y; Wang, Q P; Tamai, K; Ao, J P; Ohno, Y; Miyashita, T; Motoyama, S; Wang, D J

    2013-01-01

    The dry recessed-gate GaN metal-oxide-semiconductor field-effect transistors (MOSFETs) on AlGaN/GaN heterostructure using boron trichloride (BCl 3 ) as etching gas were fabricated and characterized. Etching with different etching power was conducted. Devices with silicon tetrachloride (SiCl 4 ) etching gas were also prepared for comparison. Field-effect mobility and interface state density were extracted from current-voltage (I-V) characteristics. GaN MOSFETs on AlGaN/GaN heterostructure with BCl 3 based dry recess achieved a high maximum electron mobility of 141.5 cm 2 V −1 s −1 and a low interface state density.

  15. Chemical characterisation of MOX grinder sludge and process evaluation for its dry recycling

    Mallik, G K; Fulzele, A K; Kothari, M; Bhargava, V K; Kamath, H S [Bhabha Atomic Research Centre, Tarapur (India). Advanced Fuel Fabrication Facility

    1997-09-01

    A large quantity of sludge (approximately 5%) is generated as a result of centreless grinding of MOX pellets. Plutonium and uranium are recovered from such sludge, consisting of coolant, resin and some metallic impurities, by a wet chemical route. A case has been made for the recycling of the sludge by an optimum dry route on the basis of chemical characterisation of sludge generated at Advanced Fuel Fabrication Facility using diamond grinding wheel. (author). 2 tabs.

  16. Chemical characterisation of MOX grinder sludge and process evaluation for its dry recycling

    Mallik, G.K.; Fulzele, A.K.; Kothari, M.; Bhargava, V.K.; Kamath, H.S.

    1997-01-01

    A large quantity of sludge (approximately 5%) is generated as a result of centreless grinding of MOX pellets. Plutonium and uranium are recovered from such sludge, consisting of coolant, resin and some metallic impurities, by a wet chemical route. A case has been made for the recycling of the sludge by an optimum dry route on the basis of chemical characterisation of sludge generated at Advanced Fuel Fabrication Facility using diamond grinding wheel. (author). 2 tabs

  17. Crystalisation of aqueous ferrofluids at the free liquid interface investigated by specular and off-specular x-ray reflectometry

    Gapon, I. V.; Petrenko, V. I.; Soltwedel, O.; Khaydukov, Yu N.; Kubovcikova, M.; Kopcansky, P.; Bulavin, L. A.; Avdeev, M. V.

    2018-03-01

    Structural organization of nanoparticles from aqueous ferrofluids on free liquid surface was studied by X-ray reflectometry. The observed layered structure at interface is associated with the evaporation of the solvent. By orienting an external magnetic during evaporation of the aqueos ferrofluids their structural organization can be manipulated. For a magnetic field applied perpendicular to the surface a more pronounced ordering along the surface normal is observed as in the case of a parallel field. Independent on the orientation of the magantic field a ∼ 20 μm thick surface layer of depleted nanoparticle concentration is found at the interface.

  18. Application of Optical Coherence Tomography Freeze-Drying Microscopy for Designing Lyophilization Process and Its Impact on Process Efficiency and Product Quality.

    Korang-Yeboah, Maxwell; Srinivasan, Charudharshini; Siddiqui, Akhtar; Awotwe-Otoo, David; Cruz, Celia N; Muhammad, Ashraf

    2018-01-01

    Optical coherence tomography freeze-drying microscopy (OCT-FDM) is a novel technique that allows the three-dimensional imaging of a drug product during the entire lyophilization process. OCT-FDM consists of a single-vial freeze dryer (SVFD) affixed with an optical coherence tomography (OCT) imaging system. Unlike the conventional techniques, such as modulated differential scanning calorimetry (mDSC) and light transmission freeze-drying microscopy, used for predicting the product collapse temperature (Tc), the OCT-FDM approach seeks to mimic the actual product and process conditions during the lyophilization process. However, there is limited understanding on the application of this emerging technique to the design of the lyophilization process. In this study, we investigated the suitability of OCT-FDM technique in designing a lyophilization process. Moreover, we compared the product quality attributes of the resulting lyophilized product manufactured using Tc, a critical process control parameter, as determined by OCT-FDM versus as estimated by mDSC. OCT-FDM analysis revealed the absence of collapse even for the low protein concentration (5 mg/ml) and low solid content formulation (1%w/v) studied. This was confirmed by lab scale lyophilization. In addition, lyophilization cycles designed using Tc values obtained from OCT-FDM were more efficient with higher sublimation rate and mass flux than the conventional cycles, since drying was conducted at higher shelf temperature. Finally, the quality attributes of the products lyophilized using Tc determined by OCT-FDM and mDSC were similar, and product shrinkage and cracks were observed in all the batches of freeze-dried products irrespective of the technique employed in predicting Tc.

  19. Método acelerado de processamento de presunto cru Accelerated method of dry-cured ham processing

    Walter Bergamin Filho

    2010-06-01

    Full Text Available Nos métodos tradicionais de elaboração de presunto cru usa-se o pernil suíno inteiro, diferentemente da metodologia proposta neste trabalho, que combinou desossa, adição de transglutaminase, massageamento e moldagem das peças previamente à secagem e maturação, objetivando reduzir o tempo de processamento do produto. Avaliaram-se os efeitos de dois teores de NaCl adicionados (T1 - 3,5% e T2 - 5%, sobre características físico-químicas e microbiológicas dos presuntos crus ao longo do processo, além da avaliação sensorial dos produtos finais. Os presuntos crus obtidos atenderam aos padrões físico-químicos e microbiológicos determinados na legislação brasileira e não foram encontradas diferenças significativas (p The traditional methodologies of dry-cured ham production use the entire ham, differently from the one proposed in this study that combined boning, addition of transglutaminase, and tumbling and moulding before the drying and ageing stages. The effects of two levels of added NaCl (T1 - 3.5% and T2 - 5% on the physicochemical and microbiological characteristics of dry-cured hams during the process and the sensory analyses of the final products were evaluated. The dry-cured hams met the physicochemical and microbiological standards of the Brazilian legislation, and no significant differences (p < 0.05 were found between the two treatments in the parameters evaluated during the process and in the final products, except for the weight loss, which was higher in T1 (39.74 ± 4.02% than in T2 (37.22 ± 2.96%. The shape and thickness of the dry-cured hams prepared in this research were adequate to slicing, and they had excellent appearance, typical aroma, and flavor similar to traditional dry-cured hams usually found in the Brazilian market receiving about 80% of acceptance by consumers.

  20. Headspace Moisture Mapping and the Information That Can Be Gained about Freeze-Dried Materials and Processes.

    Cook, Isobel A; Ward, Kevin R

    2011-01-01

    Regulatory authorities require proof that lyophilization (freeze drying) cycles have been developed logically and demonstrate uniformity. One measure of uniformity can be consistency of residual water content throughout a batch. In primary drying, heat transfer is effected by gaseous convection and conduction as well as the degree of shelf contact and evenness of heat applied; therefore residual water can be affected by container location, degree of container/tray/shelf contact, radiative heating, packing density, product formulation, and the cycle conditions themselves. In this study we have used frequency modulation spectroscopy (FMS) to create a map of headspace moisture (HSM) for 100% of vials within a number of freeze-dried batches. Karl Fischer (KF)/HSM correlations were investigated in parallel with the moisture mapping studies. A clear, linear relationship was observed between HSM and KF values for vials containing freeze-dried sucrose, implying a relatively straightforward interaction between water and the lyophilized cake for this material. Mannitol demonstrated a more complex correlation, with the interaction of different crystalline forms giving important information on the uniformity of the material produced. It was observed that annealing had a significant impact on the importance of heat transfer by conduction for vials in direct and non-direct contact with the shelf. Moisture mapping of all vials within the freeze dryer enabled further information to be obtained on the relationship of the formulation, process conditions, and equipment geometry on the intra-batch variability in HSM level. The ability of FMS to allow 100% inspection could mean that this method could play an important part in process validation and quality assurance. Lyophilization, also known as freeze drying, is a relatively old technique that has been used in its most basic form for thousands of years (e.g., preservation of fish and meat products). In its more advanced form it is

  1. Metabolomic Profiling as a Possible Reverse Engineering Tool for Estimating Processing Conditions of Dry-Cured Hams.

    Sugimoto, Masahiro; Obiya, Shinichi; Kaneko, Miku; Enomoto, Ayame; Honma, Mayu; Wakayama, Masataka; Soga, Tomoyoshi; Tomita, Masaru

    2017-01-18

    Dry-cured hams are popular among consumers. To increase the attractiveness of the product, objective analytical methods and algorithms to evaluate the relationship between observable properties and consumer acceptability are required. In this study, metabolomics, which is used for quantitative profiling of hundreds of small molecules, was applied to 12 kinds of dry-cured hams from Japan and Europe. In total, 203 charged metabolites, including amino acids, organic acids, nucleotides, and peptides, were successfully identified and quantified. Metabolite profiles were compared for the samples with different countries of origin and processing methods (e.g., smoking or use of a starter culture). Principal component analysis of the metabolite profiles with sensory properties revealed significant correlations for redness, homogeneity, and fat whiteness. This approach could be used to design new ham products by objective evaluation of various features.

  2. Anisotropy of the magnetoviscous effect in a cobalt ferrofluid with strong interparticle interaction

    Linke, J.M., E-mail: julia.linke@tu-dresden.de; Odenbach, S.

    2015-12-15

    The anisotropy of the magnetoviscous effect (MVE) of a cobalt ferrofluid has been studied in a slit die viscometer for three orientations of the applied magnetic field: in the direction of the fluid flow (Δη{sub 1}), the velocity gradient (Δη{sub 2}), and the vorticity (Δη{sub 3}). The majority of the cobalt particles in the ferrofluid exhibit a strong dipole–dipole interaction, which corresponds to a weighted interaction parameter of λ{sub w}≈10.6. Thus the particles form extended microstructures inside the fluid which lead to enhanced MVE ratios Δη{sub 2}/Δη{sub 1}>3 and Δη{sub 3}/Δη{sub 1}>0.3 even for strong shearing and weak magnetic fields compared to fluids which contain non-interacting spherical particles with Δη{sub 2}/Δη{sub 1}≈1 and Δη{sub 3}/Δη{sub 1}=0. Furthermore, a non-monotonic increase has been observed in the shear thinning behavior of Δη{sub 2} for weak magnetic fields <10 kA/m, which cannot be explained solely by the magnetization of individual particles and the formation and disintegration of linear particle chains but indicates the presence of heterophase structures. - Highlights: • The magnetoviscous effect in a ferrofluid with strong interaction is anisotropic. • The strongest effects are found in a magnetic field parallel to the shear gradient. • In strong magnetic fields the microstructure of the fluid is stable against shearing. • In weak fields the fluid behavior indicates the presence of heterophase structures.

  3. Dynamics of magnetic modulation of ferrofluid droplets for digital microfluidic applications

    Sen, Uddalok; Chatterjee, Souvick [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL, 60607 (United States); Sen, Swarnendu [Mechanical Engineering Department, Jadavpur University, Kolkata, 700032 India (India); Tiwari, Manish K. [Department of Mechanical Engineering, University College London, London, WC1E 7JE UK (United Kingdom); Mukhopadhyay, Achintya [Mechanical Engineering Department, Jadavpur University, Kolkata, 700032 India (India); Ganguly, Ranjan, E-mail: ranjan@pe.jusl.ac.in [Department of Power Engineering, Jadavpur University, Kolkata, 700098 India (India)

    2017-01-01

    Active control of droplet generation in a microfluidic platform attracts interest for development of digital microfluidic devices ranging from biosensors to micro-reactors to point-of-care diagnostic devices. The present paper characterizes, through an unsteady three-dimensional Volume of Fluid (VOF) simulation, the active control of ferrofluid droplet generation in a microfluidic T-junction in presence of a non-uniform magnetic field created by an external magnetic dipole. Two distinctly different positions of the dipole were considered – one upstream of the junction and one downstream. While keeping the ferrofluid flow rate fixed, a parametric variation of the continuous phase capillary number, dipole strength, and dipole position was carried out. Differences in the flow behaviour in terms of dripping or jetting and the droplet characteristics in terms of droplet formation time period and droplet size were studied. The existence of a threshold dipole strength, below which the magnetic force was not able to influence the flow behaviour, was identified. It was also observed that, for dipoles placed upstream of the junction, droplet formation was suppressed at some higher dipole strengths, and this value was found to increase with increasing capillary number. Droplet time period was also found to increase with increasing dipole strength, along with droplet size, i.e. an increase in droplet volume. - Highlights: • Active control of ferrofluid droplet generation in a microfluidic T-junction is demonstrated. • Unsteady three-dimensional Volume of Fluid (VOF) simulation is adopted. • Capillary number, dipole strength and position influence droplet shedding behaviour. • Magnetic actuation of a microfluidic droplet generator is characterised.

  4. Process for fabrication of dry flue gas gypsum. Verfahren zur Herstellung von trockenem Rauchgasgips

    Wirsching, F.; Hueller, R.; Limmer, B.

    1984-06-20

    According to the invention gypsum from flue gas wet desulfurization is dried without loss of crystallization water by a 1-4% sidestream of the flue gas in a suspended bed dryer and is subsequently separated in a cyclone. The sidestream is removed after the electrostatic precipitator, where the gas temperature is 100-130 degrees, and returned to the main gas stream prior to desulfurization, thus preventing the dehydration of the gypsum and eliminating the energy costs of reheating the gas stream to prevent acid condensation.

  5. Effects of drying pretreatment and particle size adjustment on the composting process of discarded flue-cured tobacco leaves.

    Zhao, Gui-Hong; Yu, Yan-Ling; Zhou, Xiang-Tong; Lu, Bin-Yu; Li, Zi-Mu; Feng, Yu-Jie

    2017-05-01

    The main characteristic of discarded flue-cured tobacco leaves is their high nicotine content. Aerobic composting is an effective method to decrease the nicotine level in tobacco leaves and stabilize tobacco wastes. However, high levels of nicotine in discarded flue-cured tobacco leaves complicate tobacco waste composting. This work proposes a drying pretreatment process to reduce the nicotine content in discarded flue-cured tobacco leaves and thus enhance its carbon-to-nitrogen ratio to a suitable level for composting. The effect of another pretreatment method, particle size adjustment, on composting efficiency was also tested in this work. The results indicated that the air-dried (nicotine content: 1.35%) and relatively long discarded flue-cured tobacco leaves (25 mm) had a higher composting efficiency than damp (nicotine content: 1.57%) and short discarded flue-cured tobacco leaves (15 mm). When dry/25 mm discarded flue-cured tobacco leaves mixed with tobacco stems in an 8:2 ratio was composted at a temperature above 55 °C for 9 days, the nicotine content dropped from 1.29% to 0.28%. Since the discarded flue-cured tobacco leaves was successfully composted to a fertile and harmless material, the germination index values increased to 85.2%. The drying pretreatment and particle size adjustment offered ideal physical and chemical conditions to support microbial growth and bioactivity during the composting process, resulting in efficient conversion of discarded flue-cured tobacco leaves into a high quality and mature compost.

  6. Exhaust circulation into dry gas desulfurization process to prevent carbon deposition in an Oxy-fuel IGCC power generation

    Kobayashi, Makoto; Nakao, Yoshinobu; Oki, Yuso

    2014-01-01

    Highlights: • Power plant with semi-closed gas turbine and O 2 –CO 2 coal gasifier was studied. • We adopt dry gas sulfur removal process to establish the system. • The exhaust gas circulation remarkably prevented carbon deposition. • Efficiency loss for exhaust gas circulation is quite small. • Appropriate operating condition of sulfur removal process is revealed. - Abstract: Semi-closed cycle operation of gas turbine fueled by oxygen–CO 2 blown coal gasification provides efficient power generation with CO 2 separation feature by excluding pre-combustion type CO 2 capture that usually brings large efficiency loss. The plant efficiency at transmission end is estimated as 44% at lower heating value (LHV) providing compressed CO 2 with concentration of 93 vol%. This power generation system will solve the contradiction between economical resource utilization and reduction of CO 2 emission from coal-fired power plant. The system requires appropriate sulfur reduction process to protect gas turbine from corrosion and environment from sulfur emission. We adopt dry gas sulfur removal process to establish the system where apprehension about the detrimental carbon deposition from coal gas. The effect of circulation of a portion of exhaust gas to the process on the retardation of carbon deposition was examined at various gas compositions. The circulation remarkably prevented carbon deposition in the sulfur removal sorbent. The impact of the circulation on the thermal efficiency is smaller than the other auxiliary power consumption. Thus, the circulation is appropriate operation for the power generation

  7. A loss-based, magnetic field sensor implemented in a ferrofluid infiltrated microstructured polymer optical fiber

    Candiani, A.; Argyros, A.; Leon-Saval, S. G.; Lwin, R.; Selleri, S.; Pissadakis, S.

    2014-01-01

    We report an in-fiber magnetic field sensor based on magneto-driven optical loss effects, while being implemented in a ferrofluid infiltrated microstructured polymer optical fiber. We demonstrate that magnetic field flux changes up to 2000 gauss can be detected when the magnetic field is applied perpendicular to the fiber axis. In addition, the sensor exhibits high polarization sensitivity for the interrogated wavelengths, providing the possibility of both field flux and direction measurements. The underlying physical and guidance mechanisms of this sensing transduction are further investigated using spectrophotometric, light scattering measurements, and numerical simulations, suggesting photonic Hall effect as the dominant physical, transducing mechanism

  8. Structurization of ferrofluids in the absence of an external magnetic field

    Zubarev, A. Yu.; Iskakova, L. Yu.

    2013-01-01

    Structural transformations in a model ferrofluid in the absence of an external magnetic field have been theoretically studied. The results agree with well-known laboratory experiments and computer simulations in showing that, if the concentration of particles and their magnetic interaction energy are below certain critical values, most particles form separate linear chains. If these parameters exceed the critical values, most particles concentrate so as to form branched network structures. The passage from chains to network has a continuous character rather than represents a discontinuous first-order phase transition.

  9. Effect of thermomagnetic treatment on the magnetic state of a ferrofluid: a polarised neutron study

    Zabenkin, V.N.; Axelrod, L.A.; Gordeev, G.P.; Kraan, W.H.; Lazebnik, I.M.; Vorobiev, A.A

    2004-07-15

    In magnetic colloids of sufficiently high particle concentration, frustration of dipolar interactions could arise as found in spin-glass systems. To understand this situation, a ferrofluid consisting of magnetite particles was frozen in either a horizontal or a vertical field and then 3D neutron-polarisation analysis was performed around the hysteresis loop in both field configurations. The same was done in the fluid state. A comparison of the data leads to the conclusion that frustration plays a key role in the self-organisation of nanoparticles in a frozen magnetic colloid.

  10. Development of active magnetic bearings and ferrofluid seals toward oil free sodium pumps

    Sreedhar, B.K.; Kumar, R. Nirmal; Sharma, Prashant; Ruhela, Shivprakash; Philip, John; Sundarraj, S.I.; Chakraborty, N.; Mohana, M.; Sharma, Vijay; Padmakumar, G.; Nashine, B.K.; Rajan, K.K.

    2013-01-01

    Sodium centrifugal pumps employ conventional oil cooled bearings and mechanical seals to support the rotor assembly outside sodium and to seal the cover gas from the atmosphere. Although engineered safety features are incorporated in the design and detailed operational procedures formulated to ensure that no oil contamination of sodium can occur, there have been incidents of oil ingress into sodium. A design variant that eliminates the need for oil in top bearings and seals is therefore a promising option. This paper discusses the work in progress to develop a magnetic bearing and ferrofluid seal combination that can achieve this purpose

  11. Dynamic Performance Characteristics of a Curved Slider Bearing Operating with Ferrofluids

    Udaya P. Singh

    2012-01-01

    Full Text Available In the present theoretical investigation, the effect of ferrofluid on the dynamic characteristics of curved slider bearings is presented using Shliomis model which accounts for the rotation of magnetic particles, their magnetic moments, and the volume concentration in the fluid. The modified Reynolds equation for the dynamic state of the bearing is obtained. The results of dynamic stiffness and damping characteristics are presented. It is observed that the effect of rotation of magnetic particles improves the stiffness and damping capacities of the bearings.

  12. Draining and drying process development of the Tokamak Cooling Water System of ITER

    Kim, Seokho, E-mail: kims@ornl.gov [US ITER, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Van Hove, Walter; Ferrada, Juan [US ITER, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Di Maio, Pietro Alessandro [University of Palermo, Viale delle Scienze, Palermo 90128 (Italy); Felde, David [Reactor and Nuclear Systems Division, ORNL, Oak Ridge, TN (United States); Raphael, Mitteau; Dell’Orco, Giovanni [ITER Organization, 13067 St Paul Lez Durance (France); Berry, Jan [US ITER, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2016-11-01

    Highlights: • A thermal-hydraulic model using RELAP was developed for the ITER FW/BLK modules to determine design parameters for the nitrogen blowout flow rate and pressure. • The analysis indicates that as low as 2 MPa of pressure difference over the blanket modules will sufficiently evacuate the water in blankets. • A limited validation study indicates that the analysis yields less conservative results to compare against data collected from experiments. Therefore, the designed blow out flow of the drying system was selected with a large margin above the measured values to ensure the blow out operation. - Abstract: The ITER Organization (IO) developed a thermal-hydraulic (TH) model of the complex first wall and blanket (FW/BLK) cooling channels to determine gas flow rate and pressure required to effectively blow out the water in the FW/BLK. In addition, US ITER conducted experiments for selected geometries of FW/BLK flow channels to predict the blowout parameters. The analysis indicates that as low as 2 MPa of pressure difference over the blanket modules will ensure substantial evacuation of the water in blankets with just a few percent remaining in the blanket flow channels. A limited validation study indicates that the analysis yields less conservative results to compare against data collected from experiments. Therefore, the designed blow out flow of the drying system was selected with a large margin above the measured values to ensure the blow out operation.

  13. Comparison of alternative flue gas dry treatment technologies in waste-to-energy processes.

    Dal Pozzo, Alessandro; Antonioni, Giacomo; Guglielmi, Daniele; Stramigioli, Carlo; Cozzani, Valerio

    2016-05-01

    Acid gases such as HCl and SO2 are harmful both for human health and ecosystem integrity, hence their removal is a key step of the flue gas treatment of Waste-to-Energy (WtE) plants. Methods based on the injection of dry sorbents are among the Best Available Techniques for acid gas removal. In particular, systems based on double reaction and filtration stages represent nowadays an effective technology for emission control. The aim of the present study is the simulation of a reference two-stage (2S) dry treatment system performance and its comparison to three benchmarking alternatives based on single stage sodium bicarbonate injection. A modelling procedure was applied in order to identify the optimal operating configuration of the 2S system for different reference waste compositions, and to determine the total annual cost of operation. Taking into account both operating and capital costs, the 2S system appears the most cost-effective solution for medium to high chlorine content wastes. A Monte Carlo sensitivity analysis was carried out to assess the robustness of the results. Copyright © 2016. Published by Elsevier Ltd.

  14. Synthesis of high intrinsic loss power aqueous ferrofluids of iron oxide nanoparticles by citric acid-assisted hydrothermal-reduction route

    Behdadfar, Behshid; Kermanpur, Ahmad; Sadeghi-Aliabadi, Hojjat; Morales, Maria del Puerto; Mozaffari, Morteza

    2012-01-01

    Monodispersed aqueous ferrofluids of iron oxide nanoparticle were synthesized by hydrothermal-reduction route. They were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy and dynamic light scattering. The results showed that certain concentrations of citric acid (CA) are required to obtain only magnetic iron oxides with mean particle sizes around 8 nm. CA acts as a modulator and reducing agent in iron oxide formation which controls nanoparticle size. The XRD, magnetic and heating measurements showed that the temperature and time of hydrothermal reaction can affect the magnetic properties of obtained ferrofluids. The synthesized ferrofluids were stable at pH 7. Their mean hydrodynamic size was around 80 nm with polydispersity index (PDI) of 0.158. The calculated intrinsic loss power (ILP) was 9.4 nHm 2 /kg. So this clean and cheap route is an efficient way to synthesize high ILP aqueous ferrofluids applicable in magnetic hyperthermia. - Graphical abstract: Monodispersed aqueous ferrofluids of iron oxide nanoparticles were synthesized by hydrothermal-reduction method with citric acid as reductant which is an efficient way to synthesize aqueous ferrofluids applicable in magnetic hyperthermia. Highlights: ► Aqueous iron oxide ferrofluids were synthesized by hydrothermal-reduction route. ► Citric acid acted as reducing agent and surfactant in the route. ► This is a facile, low energy and environmental friendly route. ► The aqueous iron oxide ferrofluids were monodispersed and stable at pH of 7. ► The calculated intrinsic loss power of the synthesized ferrofluids was very high.

  15. Energy savings by optimization of drying processes through use of models and effective control; Energibesparelser ved optimering af toerreprocesser gennem anvendelse af modeller og effektiv regulering

    Didriksen, H.; Sandvig Nielsen, J.; Weel Hansen, M.

    2001-06-01

    The aim of the project is to present a procedure to optimize existing drying processes. The optimization deals with energy consumption, capacity utilization and product quality. Other factors can also be included in the optimization, e.g. minimization of volume of discharged air. The optimization of existing drying processes will use calculation tool based on a mathematical simulation model for the process to calculate the most optimum operation situation on the basis of given conditions. In the project mathematical models have been developed precisely with this aim. The calculation tools have been developed with a user interface so that the tools can be used by technical staff in industrial companies and by consultants. The project also illustrates control of drying processes. Based on the developed models, the effect of using different types of control strategies by means of model simulations is illustrated. Three types of drying processes are treated: drum dryers, disc dryers and drying chambers. The work with the development of the simulation models has been very central in the project, as these have to be the basis for the optimization of the processes. The work is based on a large amount of information from academical literature and knowledge and experience about modelling thermal processes at dk-TEKNIK. The models constitute the core in the simulation programmes. The models describe the most important physical effects in connection with mass and energy transfer and transport under the drying for the three treated drying technologies. (EHS)

  16. On the determination of the dynamic properties of a transformer oil based ferrofluid in the frequency range 0.1–20 GHz

    Fannin, P.C.; Vekas, L.; Marin, C.N.; Malaescu, I.

    2017-01-01

    Complex susceptibility measurements provide a unique and efficient means for the investigation and determination of the dynamic properties of magnetic fluids. In particular, measurement of the frequency, f(Hz), and field, H(kA/m), dependent, complex susceptibility, χ(ω, Η)= χ′(ω, Η)−iχ″(ω, Η), of magnetic fluids has proven to be a valuable and reliable technique for investigating such properties. The experimental data presented here was obtained from measurements of a transformer oil based ferrofluid, with measurements being performed over the frequency range 0.1–20 GHz and polarising fields 0–168 kA/m. In the case of transformer oil magnetic fluids, the normal measurement emphasis has been on the investigation of their dielectric properties, including the effects which lightning may have on these properties. Little has been reported on the measurement of the corresponding magnetic susceptibility, χ(ω), of such fluids and in this paper we address this fact. Thus we consider it worthwhile, in the case of a transformer with magnetic fluid transformer oil, being affected as a result of a lightening occurrence, to have knowledge of the fluids dynamic properties, at the microwave frequencies. In the process of determining the sample susceptibility profiles, it was found that the peak value of the χ″(ω) component, was approximately constant over the frequency range 2.4–6.3 GHz. From this it was determined that the fluid was effectively operating as a wideband absorber over a bandwidth of 3.9 GHz. - Highlights: • Complex magnetic susceptibility measurements in the frequency range 0.1–20 GHz. • Determination of the dynamic properties of a transformer oil based ferrofluid. • Wideband attenuator ( Absorber) in the frequency range 2.4–6.3 GHz.

  17. Two-dimensional mathematical model for simulation of the drying process of thick layers of natural materials in a conveyor-belt dryer

    Salemović Duško R.

    2017-01-01

    Full Text Available This paper presents the mathematical model and numerical analysis of the convective drying process of thick slices of colloidal capillary-porous materials slowly moving through conveyor-belt dryer. A flow of hot moist air was used as drying agent. The drying process has been analyzed in the form of a 2-D mathematical model, in two directions: along the conveyor and perpendicular on it. The mathematical model consists of two non-linear differential equations and one equation with a transcendent character and it is based on the mathematical model developed for drying process in a form of a 1-D thin layer. The appropriate boundary conditions were introduced. The presented model is suitable for the automated control of conveyor-belt dryers. The obtained results with analysis could be useful in predicting the drying kinetics of potato slices and similar natural products.

  18. The mathematical description of the process of drying the grain of millet in the device with active hydromechanical mode

    S. T. Antipov

    2016-01-01

    Full Text Available The basis for the creation of new designs dryers laid the mathematical description of the test process, taking into account the method of loading and handling of the product in the machine, how to supply coolant or other type of energy supply, the theoretical performance, and structural (geometric component of the apparatus. To simulate the process of our work was considered of cylindrical dryers with active hydrodynamic regime and microwave energy supply, one feature of which is the loading of the product in a stream tangential coolant flow. The object of the study was chosen millet grain, because of the high biological value and high prevalence in the southern regions of the Russian Federation. On the basis of theoretical analysis, it was decided to divide the mathematical model into two conditional components: the study of heat and mass transfer study of aerodynamic component of the drying process. In this paper, we have been disclosed in detail is the second part of the process. The basis of this model were the equations of motion of millet grains by Newton's second law. The coolant in the framework of the proposed model is considered to be a continuous medium, highly compressible and has an internal viscosity, described by the Navier-Stokes equations. The initial conditions of the mathematical model were the following assumptions: the speed of the mechanical motion elements are equal to zero, the initial density of the air environment in all nodes is the equilibrium density of the air, the initial velocity of the air quality in all nodes is zero. The boundary conditions can be described as the constancy of the flow temperature and humidity, and its displacement is directly design constraints of the drying chamber. This model will be useful for professionals engaged in the problems of calculation and design of drying equipment.

  19. Impact of fermentation, drying, roasting, and Dutch processing on epicatechin and catechin content of cacao beans and cocoa ingredients.

    Payne, Mark J; Hurst, W Jeffrey; Miller, Kenneth B; Rank, Craig; Stuart, David A

    2010-10-13

    Low molecular weight flavan-3-ols are thought to be responsible, in part, for the cardiovascular benefits associated with cocoa powder and dark chocolate. The levels of epicatechin and catechin were determined in raw and conventionally fermented cacao beans and during conventional processing, which included drying, roasting, and Dutch (alkali) processing. Unripe cacao beans had 29% higher levels of epicatechin and the same level of catechin compared to fully ripe beans. Drying had minimal effect on the epicatechin and catechin levels. Substantial decreases (>80%) in catechin and epicatechin levels were observed in fermented versus unfermented beans. When both Ivory Coast and Papua New Guinea beans were subjected to roasting under controlled conditions, there was a distinct loss of epicatechin when bean temperatures exceeded 70 °C. When cacao beans were roasted to 120 °C, the catechin level in beans increased by 696% in unfermented beans, by 650% in Ivory Coast beans, and by 640% in Papua New Guinea fermented beans compared to the same unroasted beans. These results suggest that roasting in excess of 70 °C generates significant amounts of (-)-catechin, probably due to epimerization of (-)-epicatechin. Compared to natural cocoa powders, Dutch processing caused a loss in both epicatechin (up to 98%) and catechin (up to 80%). The epicatechin/catechin ratio is proposed as a useful and sensitive indicator for the processing history of cacao beans.

  20. Microbiological, physicochemical and sensory parameters of dry fermented sausages manufactured with high hydrostatic pressure processed raw meat.

    Omer, M K; Prieto, B; Rendueles, E; Alvarez-Ordoñez, A; Lunde, K; Alvseike, O; Prieto, M

    2015-10-01

    The aim of this trial was to describe physicochemical, microbiological and organoleptic characteristics of dry fermented sausages produced from high hydrostatic pressure (HHP) pre-processed trimmings. During ripening of the meat products pH, weight, water activity (aw), and several microbiological parameters were measured at zero, eight, fifteen days and after 6weeks. Sensory characteristics were estimated at day 15 and after six weeks by a test panel by using several sensory tests. Enterobacteriaceae were not detected in sausages from HHP-processed trimmings. Fermentation was little affected, but weight and aw of the HHP-processed sausages decreased faster during ripening. HHP-treated sausages were consistently less favoured than non HHP-treated sausages, but the strategy may be an alternative approach if the process is optimized. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. [Optimization of vacuum belt drying process of Gardeniae Fructus in Reduning injection by Box-Behnken design-response surface methodology].

    Huang, Dao-sheng; Shi, Wei; Han, Lei; Sun, Ke; Chen, Guang-bo; Wu Jian-xiong; Xu, Gui-hong; Bi, Yu-an; Wang, Zhen-zhong; Xiao, Wei

    2015-06-01

    To optimize the belt drying process conditions optimization of Gardeniae Fructus extract from Reduning injection by Box-Behnken design-response surface methodology, on the basis of single factor experiment, a three-factor and three-level Box-Behnken experimental design was employed to optimize the drying technology of Gardeniae Fructus extract from Reduning injection. With drying temperature, drying time, feeding speed as independent variables and the content of geniposide as dependent variable, the experimental data were fitted to a second order polynomial equation, establishing the mathematical relationship between the content of geniposide and respective variables. With the experimental data analyzed by Design-Expert 8. 0. 6, the optimal drying parameter was as follows: the drying temperature was 98.5 degrees C , the drying time was 89 min, the feeding speed was 99.8 r x min(-1). Three verification experiments were taked under this technology and the measured average content of geniposide was 564. 108 mg x g(-1), which was close to the model prediction: 563. 307 mg x g(-1). According to the verification test, the Gardeniae Fructus belt drying process is steady and feasible. So single factor experiments combined with response surface method (RSM) could be used to optimize the drying technology of Reduning injection Gardenia extract.

  2. Pattern and process of prescribed fires influence effectiveness at reducing wildfire severity in dry coniferous forests

    Arkle, Robert S.; Pilliod, David S.; Welty, Justin L.

    2012-01-01

    We examined the effects of three early season (spring) prescribed fires on burn severity patterns of summer wildfires that occurred 1–3 years post-treatment in a mixed conifer forest in central Idaho. Wildfire and prescribed fire burn severities were estimated as the difference in normalized burn ratio (dNBR) using Landsat imagery. We used GIS derived vegetation, topography, and treatment variables to generate models predicting the wildfire burn severity of 1286–5500 30-m pixels within and around treated areas. We found that wildfire severity was significantly lower in treated areas than in untreated areas and significantly lower than the potential wildfire severity of the treated areas had treatments not been implemented. At the pixel level, wildfire severity was best predicted by an interaction between prescribed fire severity, topographic moisture, heat load, and pre-fire vegetation volume. Prescribed fire severity and vegetation volume were the most influential predictors. Prescribed fire severity, and its influence on wildfire severity, was highest in relatively warm and dry locations, which were able to burn under spring conditions. In contrast, wildfire severity peaked in cooler, more mesic locations that dried later in the summer and supported greater vegetation volume. We found considerable evidence that prescribed fires have landscape-level influences within treatment boundaries; most notable was an interaction between distance from the prescribed fire perimeter and distance from treated patch edges, which explained up to 66% of the variation in wildfire severity. Early season prescribed fires may not directly target the locations most at risk of high severity wildfire, but proximity of these areas to treated patches and the discontinuity of fuels following treatment may influence wildfire severity and explain how even low severity treatments can be effective management tools in fire-prone landscapes.

  3. The initial magnetic susceptibility of polydisperse ferrofluids: A comparison between experiment and theory over a wide range of concentration

    Solovyova, Anna Y.; Goldina, Olga A.; Ivanov, Alexey O.; Elfimova, Ekaterina A.; Lebedev, Aleksandr V.

    2016-01-01

    Temperature dependencies of the static initial magnetic susceptibility for ferrofluids at various concentrations are studied using experiment and statistical-mechanical theories. Magnetic susceptibility measurements are carried out for twelve samples of magnetite-based fluids stabilized with oleic acid over a wide range of temperatures (210 K ≲T ≲ 390 K); all samples have the same granulometric composition but different volume ferroparticle concentrations (0.2 ≲ φ ≲ 0.5). Experimental results are analyzed using three theories: the second-order modified mean-field theory (MMF2) [A. O. Ivanov and O. B. Kuznetsova, Phys. Rev. E 64, 41405 (2001)]; its correction for polydisperse ferrofluids arising from Mayer-type cluster expansion and taking into account the first terms of the polydisperse second virial coefficient [A. O. Ivanov and E. A. Elfimova, J. Magn. Magn. Mater 374, 327 (2015)]; and a new theory based on MMF2 combined with the first terms of the polydisperse second and third virial contributions to susceptibility. It turns out that the applicability of each theory depends on the experimental sample density. If twelve ferrofluid samples are split into three groups of strong, moderate, and low concentrated fluids, the temperature dependences of the initial magnetic susceptibility in each group are very precisely described by one of the three theories mentioned above. The determination of a universal formula predicting a ferrofluid susceptibility over a broad range of concentrations and temperatures remains as a challenge.

  4. Dry-grind processing using amylase corn and superior yeast to reduce the exogenous enzyme requirements in bioethanol production.

    Kumar, Deepak; Singh, Vijay

    2016-01-01

    Conventional corn dry-grind ethanol production process requires exogenous alpha and glucoamylases enzymes to breakdown starch into glucose, which is fermented to ethanol by yeast. This study evaluates the potential use of new genetically engineered corn and yeast, which can eliminate or minimize the use of these external enzymes, improve the economics and process efficiencies, and simplify the process. An approach of in situ ethanol removal during fermentation was also investigated for its potential to improve the efficiency of high-solid fermentation, which can significantly reduce the downstream ethanol and co-product recovery cost. The fermentation of amylase corn (producing endogenous α-amylase) using conventional yeast and no addition of exogenous α-amylase resulted in ethanol concentration of 4.1 % higher compared to control treatment (conventional corn using exogenous α-amylase). Conventional corn processed with exogenous α-amylase and superior yeast (producing glucoamylase or GA) with no exogenous glucoamylase addition resulted in ethanol concentration similar to control treatment (conventional yeast with exogenous glucoamylase addition). Combination of amylase corn and superior yeast required only 25 % of recommended glucoamylase dose to complete fermentation and achieve ethanol concentration and yield similar to control treatment (conventional corn with exogenous α-amylase, conventional yeast with exogenous glucoamylase). Use of superior yeast with 50 % GA addition resulted in similar increases in yield for conventional or amylase corn of approximately 7 % compared to that of control treatment. Combination of amylase corn, superior yeast, and in situ ethanol removal resulted in a process that allowed complete fermentation of 40 % slurry solids with only 50 % of exogenous GA enzyme requirements and 64.6 % higher ethanol yield compared to that of conventional process. Use of amylase corn and superior yeast in the dry-grind processing industry

  5. Synthesis of ITO Powder by Dry Process and Lifetime Characteristics of the ITO Target Fabricated with its Powder

    Takahashi, Seiichiro; Itoh, Hironori; Komatsu, Ryuichi

    Lifetime of an indium tin oxide (ITO) target is an important characteristic in the production of liquid crystal displays (LCDs). Increasing the sintering density of the ITO target is assumed to lead to an increased lifetime. So far, it has been clarified that the carbon concentration in In2O3 powder, the raw material of ITO targets, influences remarkably the target lifetime. In this study, with the aim of reducing the concentration of carbon in In2O3 powder, the synthesis of In2O3 powder containing dissolved Sn by a dry process was performed.

  6. High pressure processing for dark-firm-dry beef: effect on physical properties and oxidative deterioration during refrigerated storage

    Dicky Tri Utama; Seung Gyu Lee; Ki Ho Baek; Woon Si Chung; In Ae Chung; Jung Tae Jeon; Sung Ki Lee

    2017-01-01

    Objective Study on the application of high pressure processing (HPP) for dark-firm-dry (DFD) beef was conducted to observe whether HPP has any impact on physical properties and to evaluate oxidative deterioration during refrigerated storage under vacuum. Methods The longissimus lumborum muscles obtained from Friesian Holstein steers (33?0.5 months old) with 24-h postmortem pH higher than 6.0 were vacuum-packed and subjected to pressurization at 200, 400, and 600 MPa for 180 s at 15?C?2?C; the...

  7. Quality by design in formulation and process development for a freeze-dried, small molecule parenteral product: a case study.

    Mockus, Linas N; Paul, Timothy W; Pease, Nathan A; Harper, Nancy J; Basu, Prabir K; Oslos, Elizabeth A; Sacha, Gregory A; Kuu, Wei Y; Hardwick, Lisa M; Karty, Jacquelyn J; Pikal, Michael J; Hee, Eun; Khan, Mansoor A; Nail, Steven L

    2011-01-01

    A case study has been developed to illustrate one way of incorporating a Quality by Design approach into formulation and process development for a small molecule, freeze-dried parenteral product. Sodium ethacrynate was chosen as the model compound. Principal degradation products of sodium ethacrynate result from hydrolysis of the unsaturated ketone in aqueous solution, and dimer formation from a Diels-Alder condensation in the freeze-dried solid state. When the drug crystallizes in a frozen solution, the eutectic melting temperature is above -5°C. Crystallization in the frozen system is affected by pH in the range of pH 6-8 and buffer concentration in the range of 5-50 mM, where higher pH and lower buffer concentration favor crystallization. Physical state of the drug is critical to solid state stability, given the relative instability of amorphous drug. Stability was shown to vary considerably over the ranges of pH and buffer concentration examined, and vial-to-vial variability in degree of crystallinity is a potential concern. The formulation design space was constructed in terms of pH and drug concentration, and assuming a constant 5 mM concentration of buffer. The process design space is constructed to take into account limitations on the process imposed by the product and by equipment capability.

  8. Dry fermentation of manure with straw in continuous plug flow reactor: Reactor development and process stability at different loading rates.

    Patinvoh, Regina J; Kalantar Mehrjerdi, Adib; Sárvári Horváth, Ilona; Taherzadeh, Mohammad J

    2017-01-01

    In this work, a plug flow reactor was developed for continuous dry digestion processes and its efficiency was investigated using untreated manure bedded with straw at 22% total solids content. This newly developed reactor worked successfully for 230days at increasing organic loading rates of 2.8, 4.2 and 6gVS/L/d and retention times of 60, 40 and 28days, respectively. Organic loading rates up to 4.2gVS/L/d gave a better process stability, with methane yields up to 0.163LCH 4 /gVS added /d which is 56% of the theoretical yield. Further increase of organic loading rate to 6gVS/L/d caused process instability with lower volatile solid removal efficiency and cellulose degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Circularly polarized light to study linear magneto-optics for ferrofluids: θ-scan technique

    Meng, Xiangshen; Huang, Yan; He, Zhenghong; Lin, Yueqiang; Liu, Xiaodong; Li, Decai; Li, Jian; Qiu, Xiaoyan

    2018-06-01

    Circularly polarized light can be divided into two vertically linearly polarized light beams with  ±π/2 phase differences. In the presence of an external magnetic field, when circularly polarized light travels through a ferrofluid film, whose thickness is no more than that of λ/4 plate, magneto-optical, magnetic birefringence and dichroism effects cause the transmitted light to behave as elliptically polarized light. Using angular scan by a continuously rotating polarizer as analyzer, the angular (θ) distribution curve of relative intensity (T) corresponding to elliptically polarized light can be measured. From the T  ‑  θ curve having ellipsometry, the parameters such as the ratio of short to long axis, and angular orientation of the long axis to the vertical field direction can be obtained. Thus, magnetic birefringence and dichroism can be probed simultaneously by measuring magneto-optical, positive or negative birefringence and dichroism features from the transmission mode. The proposed method is called θ-scan technique, and can accurately determine sample stability, magnetic field direction, and cancel intrinsic light source ellipticity. This study may be helpful to further research done to ferrofluids and other similar colloidal samples with anisotropic optics.

  10. Magnetic field induced flow pattern reversal in a ferrofluidic Taylor-Couette system.

    Altmeyer, Sebastian; Do, Younghae; Lai, Ying-Cheng

    2015-12-21

    We investigate the dynamics of ferrofluidic wavy vortex flows in the counter-rotating Taylor-Couette system, with a focus on wavy flows with a mixture of the dominant azimuthal modes. Without external magnetic field flows are stable and pro-grade with respect to the rotation of the inner cylinder. More complex behaviors can arise when an axial or a transverse magnetic field is applied. Depending on the direction and strength of the field, multi-stable wavy states and bifurcations can occur. We uncover the phenomenon of flow pattern reversal as the strength of the magnetic field is increased through a critical value. In between the regimes of pro-grade and retrograde flow rotations, standing waves with zero angular velocities can emerge. A striking finding is that, under a transverse magnetic field, a second reversal in the flow pattern direction can occur, where the flow pattern evolves into pro-grade rotation again from a retrograde state. Flow reversal is relevant to intriguing phenomena in nature such as geomagnetic reversal. Our results suggest that, in ferrofluids, flow pattern reversal can be induced by varying a magnetic field in a controlled manner, which can be realized in laboratory experiments with potential applications in the development of modern fluid devices.

  11. Magnetic characterization by SQUID and FMR of a biocompatible ferrofluid based on Fe3O4

    Gamarra, L F; Amaro Jr, E; Pontuschka, W M; Mamani, J B; Cornejo, D R; Oliveira, T R; Vieira, E D; Costa-Filho, A J

    2009-01-01

    Biocompatible superparamagnetic iron oxide nanoparticles of magnetite coated with dextran were magnetically characterized using the techniques of SQUID (superconducting quantum interference device) magnetometry and ferromagnetic resonance (FMR). The SQUID magnetometry characterization was performed by isothermal measurements under applied magnetic field using the methods of zero-field-cooling (ZFC) and field-cooling (FC). The magnetic behavior of the nanoparticles indicated their superparamagnetic nature and it was assumed that they consisted exclusively of monodomains. The transition to a blocked state was observed at the temperature T B = (43 ± 1) K for frozen ferrofluid and at (52 ± 1) K for the lyophilized ferrofluid samples. The FMR analysis showed that the derivative peak-to-peak linewidth (ΔH PP ), gyromagnetic factor (g), number of spins (N S ), and spin-spin relaxation time (T 2 ) were strongly dependent on both temperature and super-exchange interaction. This information is important for possible nanotechnological applications, mainly those which are strongly dependent on the magnetic parameters.

  12. Magnetic filtration of phase separating ferrofluids: From basic concepts to microfluidic device

    Kuzhir, P.; Magnet, C.; Ezzaier, H.; Zubarev, A.; Bossis, G.

    2017-06-01

    In this work, we briefly review magnetic separation of ferrofluids composed of large magnetic particles (60 nm of the average size) possessing an induced dipole moment. Such ferrofluids exhibit field-induced phase separation at relatively low particle concentrations (∼0.8 vol%) and magnetic fields (∼10 kA/m). Particle aggregates appearing during the phase separation are extracted from the suspending fluid by magnetic field gradients much easier than individual nanoparticles in the absence of phase separation. Nanoparticle capture by a single magnetized microbead and by multi-collector systems (packed bed of spheres and micro-pillar array) has been studied both experimentally and theoretically. Under flow and magnetic fields, the particle capture efficiency Λ decreases with an increasing Mason number for all considered geometries. This decrease may become stronger for aggregated magnetic particles (Λ ∝Ma-1.7) than for individual ones (Λ ∝Ma-1) if the shear fields are strong enough to provoke aggregate rupture. These results can be useful for development of new magneto-microfluidic immunoassays based on magnetic nanoparticles offering a much better sensitivity as compared to presently used magnetic microbeads.

  13. Dynamics of magnetic modulation of ferrofluid droplets for digital microfluidic applications

    Sen, Uddalok; Chatterjee, Souvick; Sen, Swarnendu; Tiwari, Manish K.; Mukhopadhyay, Achintya; Ganguly, Ranjan

    2017-01-01

    Active control of droplet generation in a microfluidic platform attracts interest for development of digital microfluidic devices ranging from biosensors to micro-reactors to point-of-care diagnostic devices. The present paper characterizes, through an unsteady three-dimensional Volume of Fluid (VOF) simulation, the active control of ferrofluid droplet generation in a microfluidic T-junction in presence of a non-uniform magnetic field created by an external magnetic dipole. Two distinctly different positions of the dipole were considered - one upstream of the junction and one downstream. While keeping the ferrofluid flow rate fixed, a parametric variation of the continuous phase capillary number, dipole strength, and dipole position was carried out. Differences in the flow behaviour in terms of dripping or jetting and the droplet characteristics in terms of droplet formation time period and droplet size were studied. The existence of a threshold dipole strength, below which the magnetic force was not able to influence the flow behaviour, was identified. It was also observed that, for dipoles placed upstream of the junction, droplet formation was suppressed at some higher dipole strengths, and this value was found to increase with increasing capillary number. Droplet time period was also found to increase with increasing dipole strength, along with droplet size, i.e. an increase in droplet volume.

  14. Dry sample storage system for an analytical laboratory supporting plutonium processing

    Treibs, H.A.; Hartenstein, S.D.; Griebenow, B.L.; Wade, M.A.

    1990-01-01

    The Special Isotope Separation (SIS) plant is designed to provide removal of undesirable isotopes in fuel grade plutonium by the atomic vapor laser isotope separation (AVLIS) process. The AVLIS process involves evaporation of plutonium metal, and passage of an intense beam of light from a laser through the plutonium vapor. The laser beam consists of several discrete wavelengths, tuned to the precise wavelength required to ionize the undesired isotopes. These ions are attracted to charged plates, leaving the bulk of the plutonium vapor enriched in the desired isotopes to be collected on a cold plate. Major portions of the process consist of pyrochemical processes, including direct reduction of the plutonium oxide feed material with calcium metal, and aqueous processes for purification of plutonium in residues. The analytical laboratory for the plant is called the Material and Process Control Laboratory (MPCL), and provides for the analysis of solid and liquid process samples

  15. Microparticles obtained by complex coacervation: influence of the type of reticulation and the drying process on the release of the core material

    Izabela Dutra Alvim

    2010-12-01

    Full Text Available Microparticles obtained by complex coacervation were crosslinked with glutaraldehyde or with transglutaminase and dried using freeze drying or spray drying. Moist samples presented Encapsulation Efficiency (%EE higher than 96%. The mean diameters ranged from 43.7 ± 3.4 to 96.4 ± 10.3 µm for moist samples, from 38.1 ± 5.36 to 65.2 ± 16.1 µm for dried samples, and from 62.5 ± 7.5 to 106.9 ± 26.1 µm for rehydrated microparticles. The integrity of the particles without crosslinking was maintained when freeze drying was used. After spray drying, only crosslinked samples were able to maintain the wall integrity. Microparticles had a round shape and in the case of dried samples rugged walls apparently without cracks were observed. Core distribution inside the particles was multinuclear and homogeneous and core release was evaluated using anhydrous ethanol. Moist particles crosslinked with glutaraldehyde at the concentration of 1.0 mM.g-1 protein (ptn, were more efficient with respect to the core retention compared to 0.1 mM.g-1 ptn or those crosslinked with transglutaminase (10 U.g-1 ptn. The drying processes had a strong influence on the core release profile reducing the amount released to all dry samples

  16. Performance improvements of binary diffractive structures via optimization of the photolithography and dry etch processes

    Welch, Kevin; Leonard, Jerry; Jones, Richard D.

    2010-08-01

    Increasingly stringent requirements on the performance of diffractive optical elements (DOEs) used in wafer scanner illumination systems are driving continuous improvements in their associated manufacturing processes. Specifically, these processes are designed to improve the output pattern uniformity of off-axis illumination systems to minimize degradation in the ultimate imaging performance of a lithographic tool. In this paper, we discuss performance improvements in both photolithographic patterning and RIE etching of fused silica diffractive optical structures. In summary, optimized photolithographic processes were developed to increase critical dimension uniformity and featuresize linearity across the substrate. The photoresist film thickness was also optimized for integration with an improved etch process. This etch process was itself optimized for pattern transfer fidelity, sidewall profile (wall angle, trench bottom flatness), and across-wafer etch depth uniformity. Improvements observed with these processes on idealized test structures (for ease of analysis) led to their implementation in product flows, with comparable increases in performance and yield on customer designs.

  17. Thin layer drying kinetics of by-products from olive oil processing.

    Montero, Irene; Miranda, Teresa; Arranz, Jose Ignacio; Rojas, Carmen Victoria

    2011-01-01

    The thin-layer behavior of by-products from olive oil production was determined in a solar dryer in passive and active operation modes for a temperature range of 20-50 °C. The increase in the air temperature reduced the drying time of olive pomace, sludge and olive mill wastewater. Moisture ratio was analyzed to obtain effective diffusivity values, varying in the oil mill by-products from 9.136 × 10(-11) to 1.406 × 10(-9) m(2)/s in forced convection (m(a) = 0.22 kg/s), and from 9.296 × 10(-11) to 6.277 × 10(-10) m(2)/s in natural convection (m(a) = 0.042 kg/s). Diffusivity values at each temperature were obtained using the Fick's diffusion model and, regardless of the convection, they increased with the air temperature. The temperature dependence on the effective diffusivity was determined by an Arrhenius type relationship. The activation energies were found to be 38.64 kJ/mol, 30.44 kJ/mol and 47.64 kJ/mol for the olive pomace, the sludge and the olive mill wastewater in active mode, respectively, and 91.35 kJ/mol, 14.04 kJ/mol and 77.15 kJ/mol in natural mode, in that order.

  18. Dry Phosphorus silicate glass etching and surface conditioning and cleaning for multi-crystalline silicon solar cell processing

    Kagilik, Ahmed S.

    2014-01-01

    As an alternative to the wet chemical etching method, dry chemical etching processes for Phosphorus silicate glass [PSG} layer removal using Trifluormethane/Sulfur Hexafluoride (CHF 3 / SF 6 ) gas mixture in commercial silicon-nitride plasma enhanced chemical vapour deposition (SiN-PECVD) system is applied. The dependence of the solar cell performance on the etching temperature is investigated and optimized. It is found that the SiN-PECVD system temperature variation has a significant impact on the whole solar cell characteristics. A dry plasma cleaning treatment of the Si wafer surface after the PSG removal step is also investigated and developed. The cleaning step is used to remove the polymer film which is formed during the PSG etching using both oxygen and hydrogen gases. By applying an additional cleaning step, the polymer film deposited on the silicon wafer surface after PSG etching is eliminated. The effect of different plasma cleaning conditions on solar cell performance is investigated. After optimization of the plasma operating conditions, the performance of the solar cell is improved and the overall gain in efficiency of 0.6% absolute is yielded compared to a cell without any further cleaning step. On the other hand, the best solar cell characteristics can reach values close to that achieved by the conventional wet chemical etching processes demonstrating the effectiveness of the additional O 2 /H 2 post cleaning treatment.(author)

  19. Multifractality and autoregressive processes of dry spell lengths in Europe: an approach to their complexity and predictability

    Lana, X.; Burgueño, A.; Serra, C.; Martínez, M. D.

    2017-01-01

    Dry spell lengths, DSL, defined as the number of consecutive days with daily rain amounts below a given threshold, may provide relevant information about drought regimes. Taking advantage of a daily pluviometric database covering a great extension of Europe, a detailed analysis of the multifractality of the dry spell regimes is achieved. At the same time, an autoregressive process is applied with the aim of predicting DSL. A set of parameters, namely Hurst exponent, H, estimated from multifractal spectrum, f( α), critical Hölder exponent, α 0, for which f( α) reaches its maximum value, spectral width, W, and spectral asymmetry, B, permits a first clustering of European rain gauges in terms of the complexity of their DSL series. This set of parameters also allows distinguishing between time series describing fine- or smooth-structure of the DSL regime by using the complexity index, CI. Results of previous monofractal analyses also permits establishing comparisons between smooth-structures, relatively low correlation dimensions, notable predictive instability and anti-persistence of DSL for European areas, sometimes submitted to long droughts. Relationships are also found between the CI and the mean absolute deviation, MAD, and the optimum autoregressive order, OAO, of an ARIMA( p, d,0) autoregressive process applied to the DSL series. The detailed analysis of the discrepancies between empiric and predicted DSL underlines the uncertainty over predictability of long DSL, particularly for the Mediterranean region.

  20. Process understanding on high shear granulated lactose agglomerates during and after drying

    Nieuwmeyer, F.J.S.

    2009-01-01

    In 2001 the FDA launched the Process Analytical Technology initiative as a response to the growing public and industrial awareness that there is a lack of process understanding required to have an optimal control of pharmaceutical manufacturing. The current research project was initiated based upon