Hall-effect analogue a.c.-ratio computer

A fully transistorised a.c.-ratio computer using a thin-film indium antimonide Hall probe is described. The output signal of the divider is proportional to the ratio of an input voltage and the magnetising current of the Hall multiplier. The characteristics of the computer are presented, and its dynamic range of operation is discussed.     

Characterization of the pneumatic behavior of a novel spouted bed apparatus with two adjustable gas inlets

Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating processes. Within this work the fluid dynamics of a novel spouted bed plant with two adjustable gas inlets is investigated. By analysis of gas phase pressure fluctuation spectra by means of fast Fourier transformation algorithm and quantitative particle image velocimetry (PIV) measurements, different operation ranges will be identified and depicted graphically. A stable spouting range will be identified if a uniform and circulating particle motion without occurrence of dead zones is observable resulting in equal gas phase pressure fluctuations. Particle velocity vector maps as well as root mean square (rms) velocity plots provided by the PIV measurements confirm the results of the determination of the stable spouting range by analysis of the gas phase pressure fluctuations.     

Changes in the fatty acid composition of dietetic ready-to-cook chicken meat products during frozen storage

A study was made on the fatty acid composition of dietetic ready-to-cook products of boneless chicken legs or breasts prepared by curing using several curing mixtures during frozen storage. Leg muscles were found to be richer in unsaturated fatty acids than breast muscles, substantial differences having been found in the contents of palmitoleic and linolenic acids. During frozen storage, the contents of unsaturated fatty acids were reduced, especially intensively in the leg muscle ready-to-cook products. The fastest changes occurred in linolenic and linolic acids and partly in palmitic acid. The level of oleic acid remained substantially unchanged throughout the storage period. Irrespective of the changes found, the ratio of unsaturated and saturated fatty acids in all the groups studied remained greater than 1 for both types of meat. The application of citrate in the curing mixture had a favourable effect on the changes, in that a minimum alteration in the contents of unsaturated fatty acids was achieved.     

Matrix Metalloproteinase Responsive,Proximity‐Activated Polymeric Nanoparticles for siRNA Delivery

Small interfering RNA (siRNA) has significant potential to evolve into a new class of pharmaceutical inhibitors, but technologies that enable robust, tissue‐specific intracellular delivery must be developed before effective clinical translation can be achieved. A pH‐responsive, smart polymeric nanoparticle (SPN) with matrix metalloproteinase (MMP)‐7‐dependent proximity‐activated targeting (PAT) is described here. The PAT‐SPN is designed to trigger cellular uptake and cytosolic delivery of siRNA once activated by MMP‐7, an enzyme whose overexpression is a hallmark of cancer initiation and progression. The PAT‐SPN is composed of a corona‐forming polyethylene glycol (PEG) block, an MMP‐7‐cleavable peptide, a cationic siRNA‐condensing block, and a pH‐responsive, endosomolytic terpolymer block that drives self‐assembly and forms the PAT‐SPN core. With this novel design, the PEG corona shields cellular interactions until it is cleaved in MMP‐7‐rich environments, shifting the SPN ζ‐potential from +5.8 to +14.4 mV and triggering a 2.5 fold increase in carrier internalization. The PAT‐SPN exhibits pH‐dependent membrane disruptive behavior that enables siRNA escape from endo‐lysosomal pathways. Intracellular siRNA delivery and knockdown of the model enzyme luciferase in R221A‐Luc mammary tumor cells is significantly increased by MMP‐7 pre‐activation (p < 0.05). These combined data indicate that the PAT‐SPN provides a promising new platform for tissue‐specific, proximity‐activated siRNA delivery to MMP‐rich pathological environments.     

Compatibilization of blends of polyethylene with a semirigid liquid crystalline polymer by PE-g-LCP copolymers

The blends of thermoplastics with liquid crystalline polymers show, in general, poor properties because of the lack of adherence between the two phases. The use of ad hoc synthesized copolymers containing the monomer units of the two polymers has been recently considered by some of us for blend compatibilization, and the results appear promising. In this work, new PE-g-LCP copolymers, prepared either by the synthesis of the LCP in the presence of a functionalized PE, or by reactive blending of the latter polymer with preformed LCP, have been employed as compatibilizing additives for blends of PE with a semirigid LCP. The morphology and the rheological and mechanical properties of the ternary blends, compared with those of samples without compatibilizers, or containing conventional maleic anhydride grafted PE, indicate that the PE-g-LCP copolymers do in fact lead to an improvement of interfacial adhesion, both in the melt and in the solid state, as well as to a modest enhancement of the mechanical properties. The results may be rationalized considering that the PE-g-LCP copolymers used by us consist of fairly short PE backbones with LCP grafts of various length. The molecules with longer LCP branches are thought to become mixed at the surface of the LCP particles and to give rise to fairly weak interaction with the PE matrix. It is argued that new PE-g-LCP copolymers synthesized from higher molar mass functionalized PE samples might show much better compatibilizing performance.     

Some possibilities for improving the holographic recording characteristics in Bi12Si020monocrystals

On the basis of detailed consideration of the influence of a number of factors such as recording and readout light intensity, condition of preliminary illumination, electrical contact properties, parameters of the applied external electric field (direct and alternating), and the anisotropic properties of light diffraction from a simple hologram (diffraction grating), possibilities are sought for optimal conditions of holographic recording in crystal of the type Bi12(Si, Ge, Ti)O20.     

Effects of some technologies of curing uncomminuted meat products on their flavour Part 2. Contents of carbonyl compounds and their relation to flavour

Studies were made of carbonyl compounds and the flavour components of two types of uncomminuted pork products, loin and neck, manufactured by three technologies: I. brine curing; 11. dry curing, and 111. dry curing using 0.6 % honey. Meat flavour was evaluated by a trained panel by the method of sensory profiles, using a 5 point scale. A considerable increase was found in the contents of total carbonyl compounds in the meat products manufactured by technology II, and particularly by technology III. The difference in mono-carbonyl compounds and ketoglycerides was insignificant. The data from the sensory analysis indicated a more intensive flavour in the latter meat products, which was particularly marked in the those made of loin.