A multiple-step slit die rheometer for rheological characterization of extruded starch melts

Extrusion cooking is a very important process in the field of cereal and snack manufacturing. The rheological properties of the starch based matrix strongly influence this process. A newly developed online rheometer was mounted on a twin screw extruder in order to measure these properties. It was possible to obtain viscosity of wheat flour and corn grits at typical extrusion cooking conditions over a shear rate range of three decades. Flow curves for varying screw speed and water content at a constant thermomechanical history of the starch were measured. Also the temperature dependence of the apparent viscosities could be determined showing activation energies in the range found for synthetic polymers. Furthermore, additional pressure drops that occur at step changes of the slit height were detected. Thus, it was possible to evaluate visco-elastic properties of extruded starch melts at different extrusion cooking conditions.     

ERCS08: A FORTRAN program equipped with a Windows graphics user interface that calculates ECPSSR cross sections for the removal of atomic electrons

ERCS08 is a program for computing the atomic electron removal cross sections. It is written in FORTRAN in order to make it more portable and easier to customize by a large community of physicists, but it also comes with a separate windows graphics user interface control application ERCS08w that makes it easy to quickly prepare the input file, run the program, as well as view and analyze the output. The calculations are based on the ECPSSR theory for direct (Coulomb) ionization and non-radiative electron capture. With versatility in mind, the program allows for selective inclusion or exclusion of individual contributions to the cross sections from effects such as projectile energy loss, Coulomb deflection of the projectile, perturbation of electron's stationary state (polarization and binding), as well as relativity. This makes it straightforward to assess the importance of each effect in a given collision regime. The control application also makes it easy to setup for calculations in inverse kinematics (i.e. ionization of projectile ions by target atoms or ions).

Program summary

Program title: ERCS08Catalogue identifier: AECU_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECU_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 12 832No. of bytes in distributed program, including test data, etc.: 318 420Distribution format: tar.gzProgramming language: Once the input file is prepared (using a text editor or ERCS08w), all the calculations are done in FORTRAN using double precision.Computer: see “Operating system” belowOperating system: The main program (ERCS08) can run on any computer equipped with a FORTRAN compiler. Its pre-compiled executable file (supplied) runs under DOS or Windows. The supplied graphics user interface control application (ERCS08w) requires a Windows operating system. ERCS08w is designed to be used along with a text editor. Any editor can be used, including the one that comes with the operating system (for example, Edit for DOS or Notepad for Windows).Classification: 16.7, 16.8Nature of problem: ECPSSR has become a typical tag word for a theory that goes beyond the standard plane wave Born approximation (PWBA) in order to predict the cross sections for direct (Coulomb) ionization of atomic electrons by projectile ions, taking into account the energy loss (E) and Coulomb deflection (C) of the projectile, as well as the perturbed stationary state (PSS) and relativistic nature (R) of the target electron. Its treatment of non-radiative electron capture to the projectile goes beyond the Oppenheimer-Brinkman-Kramers approximation (OBK) to include the effects of C, PSS, and R. PSS is described in terms of increased target electron binding (B) due to the presence of the projectile in the vicinity of the target nucleus, and (for direct ionization only) polarization of the target electron cloud (P) while projectile is outside the electron's shell radius. Several modifications of the theory have been recently suggested or endorsed by one of its authors (Lapicki). These modifications are sometimes explicit in the tag word (for example, eCPSSR, eCUSR, ReCPSShsR, etc.) A cross section for the ionization of a target electron is assumed to equal the sum of the cross sections for direct ionization (DI) and electron capture (EC).Solution method: The calculations are based on the ECPSSR theory for direct (Coulomb) ionization and non-radiative electron capture. With versatility in mind, the program allows for selective inclusion or exclusion of individual contributions to the cross sections from effects such as projectile energy loss, Coulomb deflection of the projectile, perturbation of electron's stationary state (polarization and binding), as well as relativity. This makes it straightforward to assess the importance of each effect in a given collision regime. The control application also makes it easy to setup for calculations in inverse kinematics (i.e. ionization of projectile ions by target atoms or ions).Restrictions: The program is restricted to the ionization of K, L, and M electrons. The theory is non-relativistic, which effectively limits its applicability to projectile energies up to about 50 MeV/amu. However, the theory is extended to apply to relativistic light projectiles. Radiative electron capture is not taken into account, since its contribution is found to be negligible in the collision regimes covered by the ECPSSR theory.Unusual features: Windows graphics user interface along with a FORTRAN code for calculations, selective inclusion or exclusion of specific corrections, inclusion of the extension to relativistic light projectiles, inclusion of non-radiative electron capture.Running time: Running the program using the input data provided with the distribution only takes a few seconds.     

Identification of some acids from autoxidation of methyl linoleate

The acids from autoxidation of methyl linoleate have been analyzed as their methyl esters by combined capillary gas chromatography-mass spectrometry (GC-MS). The principal components were hexanoic, trans-2-octenoic, suberic and azelaic acid. Minor components included formic, pentanoic, heptanoic, trans-2-heptenoic, octanoic and nonanoic acid. In addition,trans-2,3-epoxy-octanoic acid was isolated as its methyl ester by preparative GLC and was identified by means of NMR, high resolution MS, IR and by conversion to a known derivative. W. Utiliz. Res. Dev. Div., ARS, USDA.     

Toxicity assessment of heavy metal mixtures by Lemna minor L

The discharge of untreated electroplating wastewaters directly into the environment is a certain source of heavy metals in surface waters. Even though heavy metal discharge is regulated by environmental laws many small-scale electroplating facilities do not apply adequate protective measures. Electroplating wastewaters contain large amounts of various heavy metals (the composition depending on the facility) and the pH value often bellow 2. Such pollution diminishes the biodiversity of aquatic ecosystems and also endangers human health. The aim of our study was to observe/measure the toxic effects induced by a mixture of seven heavy metals on a bioindicator species Lemna minor L. Since artificial laboratory metal mixtures cannot entirely predict behaviour of metal mixtures nor provide us with informations relating to the specific conditions in the realistic environment we have used an actual electroplating wastewater sample discharged from a small electroplating facility. In order to obtain three more samples with the same composition of heavy metals but at different concentrations, the original electroplating wastewater sample has undergone a purification process. The purification process used was developed by Orescanin et al. [Orescanin V, Mikeli? L, Luli? S, Nad K, Rubci? M, Pavlovi? G. Purification of electroplating wastewaters utilizing waste by-product ferrous sulphate and wood fly ash. J Environ Sci Health A 2004; 39 (9): 2437-2446.] in order to remove the heavy metals and adjust the pH value to acceptable values for discharge into the environment. Studies involving plants and multielemental waters are very rare because of the difficulty in explaining interactions of the combined toxicities. Regardless of the complexity in interpretation, Lemna bioassay can be efficiently used to assess combined effects of multimetal samples. Such realistic samples should not be avoided because they can provide us with a wide range of information which can help explain many different interactions of metals on plant growth and metabolism. In this study we have primarily evaluated classical toxicity endpoints (relative growth rate, Nfronds/Ncolonies ratio, dry to fresh weight ratio and frond area) and measured guaiacol peroxidase (GPX) activity as early indicator of oxidative stress. Also, we have measured metal accumulation in plants treated with waste ash water sample with EDXRF analysis and have used toxic unit (TU) approach to predict which metal will contribute the most to the general toxicity of the tested samples.     

Detection of suspiciousness as a function of pleas for honesty.

Conducted an experimental study with 161 male undergraduates to assess the relative effect of 2 sophistication levels of Ss (informed or naive) and 3 pleas for their honesty (personal, impersonal, or control) on a postexperimental questionnaire designed to measure suspiciousness within the context of a deception experiment. Results convincingly indicate that properly designed postexperimental techniques will accurately assess suspicions from truly suspicious Ss while keeping naive Ss from falsely reporting suspicions. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Internal bremsstrahlung: Exact relativistic independent-particle-approximation calculations

Recently, natural and social scientists have pointed out that the need to make scientific results apply to both sexes is not met by simply adding women as research subjects. They suggest that the social and biological specificity of both sexes must be recognized and adjustments made to the ways questions are asked, hypotheses are generated, research subjects are chosen, and data are analysed. It is important to examine the definitions, concepts and methods used in research in occupational health to see whether they obstruct recognition of women's occupational health problems or interfere with gender-neutral standard setting. Unravelling the effects of sex on occupational health is complicated by the fact that women and men do not, by and large, work at the same jobs. Definitions of "work" must in some cases be adjusted to take account of women's occupations, just as definitions involving "health" must include women's biological specificity. Appropriate changes must be made to generate sex-inclusive definitions of exposures to occupational hazards and of health effects. Methods for evaluating exposures typical of women's work must be developed. Women and their work must be appropriately included when standards for occupational exposures are set. If these adjustments are not made, women's occupational health problems will be seriously underestimated and understanding of health problems of both sexes will be hindered. Sociological analysis should also be done to reveal the mechanisms by which biased concepts and procedures develop and are reinforced.     

Biomonitoring of mercury in polluted coastal area using transplanted mussels

The Kastela Bay is heavily polluted with inorganic mercury originated from direct discharges from the chlor-alkali plant, which operated in the period from 1950 to 1990. Even though the plant was closed 15 years ago, elevated levels of total mercury are still evident in surface sediments of the bay. In order to assess the availability of remobilized mercury to marine organisms, cultured mussels (M. galloprovincialis) were transplanted from pristine area to Kastela Bay, in the period from September 2000 to March 2001. Mussel samples were collected for the analysis of THg and MeHg in whole soft tissue, gills and digestive gland. Surface sediments and suspended matter were collected for the analysis of THg. Digestive gland was the target organ for the accumulation of THg, while concentrations of MeHg were similar in all analyzed tissues. The percentage of MeHg in mussel tissues (4-27%) was characteristic for the areas contaminated with inorganic mercury. A significant negative correlation was observed between the THg concentration in the tissues and the percentage of MeHg. Concentrations of THg in mussel tissues, which were decreasing from the source of contamination in an anticlockwise direction towards the exit of the bay, were significantly positively correlated to THg content in sediment and suspended particles. Spatial distribution of mercury species (THg and MeHg) in different environmental compartments was in accordance with the prevailing circulation in the bay. Data obtained through 6 months of biomonitoring experiment indicated that digestive gland was more sensitive indicator of THg concentrations in the environment than the whole organism or gills. As for MeHg, all tissues were equally suitable as biomonitors of MeHg concentrations in the environment.     

Reduction of mouldboard plough share wear by a combination technique of hardfacing

This paper presents comparison of wear of regular mouldboard plough shares and two plough shares made of different basic materials, steel EN 10027 (HF-1) and EN 50Mn7 (HF-2), hardfaced by a combination of two welding processes, namely shielded metal arc welding (SMAW) and high-frequency induction welding (HFIW). Wear was determined by measurements of the changes of dimensions and weight during ploughing of sandy clay soil in Croatia. The dimensions and weight losses were lower for both types of hardfaced plough shares in comparison to regular shares, and lower fuel consumption and a higher rate of work were achieved with hardfaced plough shares. Hardfaced plough shares also offer lower production costs in comparison to regular plough shares. According to the overall results, this protection method can be recommended as an efficient solution for plough share wear protection.     

Elastic properties of extruded starchy melts containing wheat bran using on-line rheology and dynamic mechanical thermal analysis

Addition of wheat bran reduces the expansion volumes of extruded cereals. This may be explained by the influence wheat bran has on the elastic properties of the melt. The elastic properties of extruded refined wheat flour supplemented with wheat bran were investigated using a complementary on-line and an off-line rheological technique. The Bagley pressure (end pressure), reflecting extensional properties of the melt, was measured on-line using the orifice die method (dies with different lengths). The storage modulus of the extruded samples was measured using dynamic mechanical thermal analysis (DMTA). Increasing the bran concentration to an intermediate level significantly increased the Bagley pressure likely due to a reduced mobility of starch molecules. Further increasing the bran concentration significantly decreased the Bagley pressure. This might be caused by physical rupture of the melt at the die exit due to the low adhesion properties between starch and bran particles. This change in Bagley pressure indicates that the elastic properties of the composite melt may be reduced by bran particles. The storage modulus measured by DMTA was decreased when increasing the bran concentration, further supporting a potential decrease of the elastic properties of the melt with bran.