Oxidation-Based Model for Thermal Barrier Coating Life

A procedure is described for modeling the lives of thermal barrier coatings subjected to high-temperature environments. The model is used to calculate cycles-to-failure as a function of heating cycle duration. It is based on the presumption that oxidation is the single important time-dependent factor which limits the life of these coatings, and that oxidation-induced strains combine with cyclic strains to promote slow crack growth in the ceramic layer. Good agreement is obtained between calculated and experimental lives for specimens tested in a furnace. This shows that an oxidation-based approach is promising. The importance of reproducible specimen preparation is also discussed.     

Nucleic Acid Content of Bovine Bone Marrow, Muscle and Mechanically Deboned Beef

The purpose of this study was to quantify nucleic acids in bone marrow and to determine if nucleic acid levels in mechanically deboned meat (MDM) which contains marrow are high enough to be nutritionally hazardous. Bone marrow from cervical and lumbar vertebrae, MDM and longissimus muscle samples were analyzed for DNA and RNA. Nucleic acid concentrations in marrow were influenced by class of animal and by anatomical location of bones. Marrow, MDM and muscle averaged 20.3, 7.6, and 1.4 mg DNA/g, and 1.9, 0.7 and 0.4 mg RNA/g respectively, indicating that increased levels of marrow in MDM would increase nucleic acid content. Nevertheless, processed meat is limited to 20% of the meat block as MDM. At this level processed meats would contain moderate amounts of nucleic acids which would not be substantially greater than levels already found in processed meat.     

EFFECTS OF PAPAIN,FICIN AND SPLEEN ENZYMES ON TEXTURAL,VISUAL, COOKING AND SENSORY PROPERTIES OF BEEF BULLOCK RESTRUCTURED STEAKS1

Twelve blends were formulated from young bullocks to contain 0, 0.125, 0.250 or 0.375% spleen extract, papain or ficin enzymes. All blends were analyzed for chemical, sensory and visual properties. Control blends were superior to all enzyme treated restructured steaks for flavor desirability and overall satisfaction ratings. Type and level of enzyme significantly decreased fat and increased moisture percentages, and the enzymatic degradation of the myofibril caused emulsion instability. Cooking loss and cooking time were longer for blends made with enzymes as the protein matrix was denatured extensively. Storage time was reduced significantly with the addition of spleen enzymes and all restructured steaks were undesirable for raw appearance ratings. Restructured steaks formulated with these enzymes had reduced connective tissue amount; however, the proper level of these enzymes needs to be studied further in order to minimize the problems in binding and sensory properties.     

Effects of Electrical Stimulation on the Functional Properties of Lamb Muscle

One side from each of eleven lamb carcasses was electrically stimulated (60 Herz alternating current at 240v followed by 420v) within 45 min postmortem. Three carcasses (stimulated and respective control sides) were rapidly chilled (1°C), three carcasses received a delayed chill (12°C until pH 6.0 was attained, then excision and 1°C), and three carcasses were slowly chilled (12°C). Measurements beginning at 44 hr postmortem showed that stimulation increased the sarcomere lengths but had few consistent or significant effects on water-holding capacity, protein solubility, emulsifying capacity, gel strength, cooking loss, or binding strength. The remaining two carcasses were rapidly chilled and their meat was manufactured into frankfurters. The emulsion stability was slightly improved by stimulation but smokehouse weight loss, Warner-Bratzler shear force, penetration force, cooking loss, and sensory characteristics were unaffected.     

Wheat Hardness: Time Required to Grind Wheat with the Brabender Automatic. Micro Hardness Tester

The Brabender automatic micro hardness tester was used to measure the time required to grind 4g of wheat. Effects of temperature and moisture were determined. Increasing temperature from 15 to 40°C generally decreased grinding time, but differentiation among samples was better at 15°C than at higher temperatures. Increasing moisture content increased the grinding time of soft wheat much more than it increased the grinding time of hard wheat. The tester can detect differences related to milling properties of hard wheats, hardness among some wheat classes and among some varieties representing a single class of wheat. The instrument can also be used to evaluate hardness of plant-breeders' samples, so that selections with extreme hardness or softness can be discarded, and to distinguish between hard and soft wheats in marketing channels.     

ALPHA WAVES-ARTIFACTS?

J. L. KENNEDY (SEE 35:2) HAS ARGUED THAT ALPHA RHYTHM RECORDINGS ARE ARTIFACTS CAUSED BY THE MECHANICAL PULSATION OF A GEL (THE LIVING BRAIN) WITH DIFFERENT ELECTRICAL POTENTIALS. KENNEDY'S HYPOTHESIS SEEMED INSUFFICIENTLY SUPPORTED, AND CONTRADICTED THE CONSENSUS CONCERNING THE ORIGIN OF ALPHA WAVES. SIGNIFICANT RECENT RESEARCH IS EXAMINED WHICH PROVIDES STRONG EVIDENCE THAT ALPHA WAVES REPRESENT A BASIC CELLULAR PROCESS PROBABLY RELATED TO EXCITABILITY. IT IS SUGGESTED THAT KENNEDY'S PHENOMENON BE EXPLORED FURTHER TO CLARIFY ANY EFFECT IT MAY HAVE ON STANDARD EEG RECORDINGS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)