Effects of Surface Concentration on Drying Behavior of Carbohydrate Solutions

As the surface properties of the drying materials are very important not only for the drying rate but also for the quality change during drying, the effects of surface concentration on the drying behavior of liquid foods (sugar solutions) were investigated by isothermal drying experiments and by numerical calculation experiments. The isothermal drying experiments with gelled sugar solution systems (sucrose and maltodextrin) were carried out at various relative humidity (RH) values (RH = 0 to 84%). Separate experiments were carried out for determination of the desorption isotherms.

The isothermal drying curves of sugar solutions at RH = 0 to 51% were very similar. Numerical simulations also showed that the drying curves of these sugars at the surface concentration = 0 and 0.1 are almost the same, although the concentration distributions are different.

When a small amount of gelatin was added to sugar solutions, the drying rate decreased remarkably as the gelatin might form a thin film (skin) near the surface, and consequently the retention of ethanol increased.     

Synthesis,structural characterization,and antiproliferative/cytotoxic effects of a novel modified poly(maleic anhydride-co-vinyl acetate)/doxorubicin conjugate

Polymer Bulletin - Drug carrier, poly(maleic anhydride-co-vinyl acetate) (MAVA or poly[MA-co-VA]) copolymer, was traditionally synthesized by free radical chain polymerization reaction, in methyl...     

Dimensional changes and creep of silica core ceramics used in investment casting of superalloys

Dimensional changes and creep deformation of a silica/zircon (74%/24%, respectively) and a high silica (93% silica and 3% zircon) ceramic were characterized and compared. All specimens were tested with a thermal profile that consisted of a 300°C/h heating rate to 1475 or 1525°C, followed by a one-hour isothermal hold (where each specimen was compressively crept under a static stress of 2.07, 4.14, or 6.21 MPa). The specimens were cooled at a rate of 900°C/h under stress. Dimensional changes were interpreted from apparent thermal expansion behavior during heating as well as before-and-after dimensional measurements. The silica/zircon ceramic generally exhibited less total contraction than the high silica ceramic for a specific test condition even though it crept faster at all stresses and temperatures during the one-hour isothermal/isostress segment. This indicates that the total contraction for both was dominated by reinitiated sintering and subsequent cristobalite formation that occurred during the heating segment. Minimum creep rate during the one-hour isothermal/isostress segment was examined as a function of stress and temperature for both ceramics using a power-law creep model. Creep-rate stress exponents (n) and activation energies (Q) were equivalent (within 95% confidence) for both ceramics showing that their different contents of zircon (3 vs. 24%) did not affect them. Lastly, n 1.3–1.4 and Q 170 kJ/mol indicate that diffusion-assisted crystallization of cristobalite, combined with power-law sintering owing to the high concentration of porosity (28–30%) was likely the rate-limiting mechanism in the creep deformation for both ceramics.     

How accurately do drivers evaluate their own driving behavior? An on-road observational study

Self-assessment of driving skills became a noteworthy research subject in traffic psychology, since by knowing one's strenghts and weaknesses, drivers can take an efficient compensatory action to moderate risk and to ensure safety in hazardous environments. The current study aims to investigate drivers’ self-conception of their own driving skills and behavior in relation to expert evaluations of their actual driving, by using naturalistic and systematic observation method during actual on-road driving session and to assess the different aspects of driving via comprehensive scales sensitive to different specific aspects of driving. 19–63 years old male participants (N = 158) attended an on-road driving session lasting approximately 80 min (45 km). During the driving session, drivers’ errors and violations were recorded by an expert observer. At the end of the driving session, observers completed the driver evaluation questionnaire, while drivers completed the driving self-evaluation questionnaire and Driver Behavior Questionnaire (DBQ). Low to moderate correlations between driver and observer evaluations of driving skills and behavior, mainly on errors and violations of speed and traffic lights was found. Furthermore, the robust finding that drivers evaluate their driving performance as better than the expert was replicated. Over-positive appraisal was higher among drivers with higher error/violation score and with the ones that were evaluated by the expert as “unsafe”. We suggest that the traffic environment might be regulated by increasing feedback indicators of errors and violations, which in turn might increase the insight into driving performance. Improving self-awareness by training and feedback sessions might play a key role for reducing the probability of risk in their driving activity.     

Structure, Properties and Behavior of Kyanite： Use in Refractory Monolithics

1 Introduction Kyanite is an important naturally occurring in-dustrial mineral and is used in the manufacture of avariety of industrial ceramic products; notable exam-ples include refractories and porcelains. It is a high-pressure polymorph of the aluminosilicates of the ne-sosilicate group, which includes kyanite, sillimanite,and andalusite. These three aluminous or alumina-rich minerals are chemically identical with the compo-sition, Al_2SiO_5, but have different crystal structuresand physical properties. It is, however, their alumina     

Untersuchung der wirkenden Kräfte beim Entstehen und Ablösen von Einzelblasen mit einem Simulationsmodell

Verwendung eines früher entwickelten mathematischen Modells zur Simulierung der Vorgänge bei der Entstehung von Einzelblasen in Flüssigkeiten und Stahl. Berechnung der wirkenden Kräfte und ihrer Anteile.     

Untersuchung der Abhängigkeiten des Ablösevolumens einzelner Gasblasen mit einem Simulationsmodell

Mit einem früher¹) entwickelten, mathematischen Modell zur Simulierung der Vorgänge bei der Entstehung, Ablösung und Bewegung einzelner Blasen, die an Düsen gebildet werden, werden Abhängigkeiten des Ablösevolumens von den Flüssigkeitseigenschaften sowie von konstruktiven und operativen Parametern untersucht. Die Ergebnisse des Simulationsmodells werden mit experimentellen Daten aus dem Schrifttum verglichen. Die Übereinstimmung ist überraschend gut. Als Vorteil des Simulationsmodells stellte sich unter anderem heraus, daß bei der Untersuchung des Einflusses der physikalischen Eigenschaften der flüssigen Phase wie Dichte, Viskosität und Grenzflächenspannung der Einfluß der Veränderung eines einzelnen Parameters unter Konstanthalten aller übrigen untersucht werden konnte, was in Experimenten mit realen Flüssigkeiten nicht möglich ist. Das Blasenablösevolumen steigt (grob gesprochen) mit zunehmender Grenzflächenspannung sowie abnehmender Dichte und ist unabhängig von der dynamischen Viskosität, solange diese unter etwa 100 mPas bleibt. Bei kleinen Laplace-Kostanten ist es unabhängig von der Laplace-Konstanten, erst bei höheren Werten dieser Konstante hängt das Ablösevolumen deutlich von ihr ab. Die Tendenz zur Annäherung an ein Grenzgesetz ist deutlich. Der Düsenquerschnitt hat bei kleinen Gasdurchsätzen großen Einfluß auf das Ablösevolumen, sein Einfluß sinkt mit zunehmendem Gasdurchsatz, bei hohem Gasangebot wächst das Ablösevolumen deutlich mit dem Gasdurchsatz, auch hier ist die Annäherung an ein Grenzgesetz unverkennbar. Kleine Ablösevolumina bedeuten durch die damit verbundene feine Dispergierung des Gases eine große Grenzflächenentfaltung. Maßnahmen zur Erzielung kleiner Ablösevolumina werden angegeben.     

Electronic Nose and Its Applications: A Survey

Machine Intelligence Research - In the last two decades, improvements in materials, sensors and machine learning technologies have led to a rapid extension of electronic nose (EN) related research...