Development and Characterization of Biodegradable/Edible Wheat Protein Films

Biodegradable and edible films were prepared from three types of wheat flours: commercial bread, hard red winter, and soft white. Films were produced at two pH values (4 and 11) and tested for oxygen permeability as related to temperature. Films were also produced with a cross-linked agent and tested for tensile strengths. Oxygen permeability was 5.9 × 10^?20 to 18.5 × 10^?20 m³O₂ m m^?2 s^?1 Pa^?1 similar to values for commercial nylon. The oxygen permeability activation energy varied from 9.1 to 14.5 kcal mol^?1, depending on type of flour and pH did not affect oxygen permeability. Presence of the cross-linking agent increased the strength of films and elongation at break ranged from 490% to 640%, while tensile stress at break ranged from 25.8 × 10^?3 kg m^?2 to 44.1 × 10^?3 kg m^?2, lower than commercial nylon.     

CYSTEINE PROTEINASE ACTIVITY IN JUMBO SQUID (DOSIDICUS GIGAS) HEPATOPANCREAS EXTRACTS

Jumbo squid specimens were captured, dissected, and the hepatopancreas was freeze dried for the extraction of proteolytic enzymes. An autolysis experiment conducted at 25C showed two peaks with maximum proteolysis at pH 3 and 5. The proteinase activity of the extract was measured using azocasein, BANA, Z‐PAAFC and Z‐AAAFC substrates. Activity of the extract with azocasein (pH 5) had a maximum at 55C and increased threefold with the inclusion of cysteine or DTT. The proteinase activity remained at least at 60% of the original after 45 h at 4C in the pH range of 3–8. Activity was inhibited 70–85% when extracts were treated with cysteine proteinase specific inhibitors. The proteinases extracted from jumbo squid hepatopancreas are mainly of the cysteine type and have significant activity towards a cathepsin L specific substrate. The understanding of proteinases from this tissue could have implications for quality control of jumbo squid food products.     

A VISCOSITY MODEL FOR A COOKING DOUGH1

A five parameter semi-empirical model is developed describing the apparent viscosity of a cooking dough as a function of applied shear rate, temperature, and time-temperature history. Such a model will be useful in the mathematical simulation of the extrusion cooking process. Other factors which can affect the apparent viscosity of a cooking dough are also discussed. The viscosity model is verified and the constants evaluated for a typical dough by combining the results of Amylograph and capillary viscometer experiments.     

A GENERAL APPROACH TO THE STUDY OF SPATIAL SYSTEMS;I. The Relational Representation of Measurable Attributes

In this, the First part of a two part work, a general model of spatial organization is introduced. Following a brief synopsis of some of Spinoza's and Leibniz's views regarding natural structure, an extension of the Spinozian model is presented in which the attribute spatial extension is portrayed as a relational system that implicitly underlies the differentiation of sensible space into “modifications” (“natural systems”) and the latter's subdifferentiation into “modes” On the basis of this model, all instances of modal differentiation are understood to take place in a manner explained by this relational structure, the existence (but not the specific characteristics) of which is initially assumed. The nature of the structure is then deduced according to a “most-probable-state” kind of logic; next, it is demonstrated via simulation that the resulting aspatial model of internal relations has a corresponding spatial interpretation (and therefore, in theory, that sensible space structures can be supported by the particular rational ordering posed). The matter of how to apply the model to the study of real world systems is taken up last; discussion focuses on related aspects of the treatment of equilibrium and nonequilibrium systems and the recognition and measurement of modal structures.     

LANGUAGE THEORY: CONSENSUAL SELECTION OF DYNAMICS

Both representational and self organizing approaches to language avoid in different ways the concept of symbol We argue that representationalism denies the particular aspects of a subjects embodiment while the self organizing paradigm refuses to address the utility of the concept of symbol and its evolutionary relationship with an environment We call for an inclusive approach that considers the syntactic semantic and pragmatic aspects of language We further offer a mathematical structure defined in terms of fuzzy set and evidence theories as a model of linguistic categories under this inclusive framework     

再生细骨料逐级取代对再生砂浆强度和微观形貌的影响

基于天然砂分计筛余百分率,采用再生细骨料按照0～0.315 mm、0～0.63 mm、0～1.25 mm、0～2.5 mm和0～5.0 mm不同粒级逐级取代天然砂制作再生砂浆,测定其在0.55、0.60、0.65水灰比下7d、14d和28 d的抗折抗压强度和微观形貌.试验结果表明:再生砂浆试件的抗折抗压强度均大于空白试件,且随着再生细骨料逐级取代率的提高而增大;当再生细骨料100％逐级取代天然砂时,龄期为14 d时的再生砂浆的强度增长最大;28 d时,再生砂浆抗压强度的降低幅度随着水灰比的增加而增加,但抗折强度的降低幅度却随着水灰比的增加而减小;随水化龄期的增加,再生砂浆中水化产物不断增多,界面过渡区越来越密实.     

Phase Separation in the System (Fe,Mn)O

Transmission electron microscopy was used to observe variations in composition in single crystals of Fe _y Mn_{1– y} O_{1+] x} on a scale of 100 to 500 Å. Compositional fluctuations were resolved as lamellar-like striations oriented primarily in the [100] direction. Specimens had been equilibrated at 900°C in oxygen partial pressures within the monoxide phase region and then quenched to room temperature. A region of solid-solid immiscibility in the monoxide phase field is proposed. A different submicrostructure resulted from low-temperature decomposition (150°C) due to localized heating when samples were prepared by ion-bombardment thinning.