Differential Scanning Calorimetry (DSC) Analyses Of Superelastic And Nonsuperelastic Nickel-Titanium Orthodontic Wires

The purpose of this study was to determine the transformation temperatures for the austenitic, martensitic, and rhombohedral (R) structure phases in representative as-received commercial nitinol (NiTi) orthodontic wire alloys, to reconcile discrepancies among recent publications. Specimens were examined by differential scanning calorimetry (DSC) over a temperature range from approximately −170° C to 100° C, with a scanning rate of 10° C per minute. Two different pathways, with the intermediate R structure either absent or present, were observed for the transformation from martensitic to austenitic NiTi, whereas the reverse transformation from austenitic to martensitic NiTi always included the R structure. The enthalpy (ΔH) for the transformation from martensite to austenite ranged from 0.3 to 35 calories per gram. The lowest ΔH value for the nonsuperelastic Nitinol wire is consistent with a largely work-hardened, stable, martensitic microstructure in this product. The DSC results indicate that the transformation processes are broadly similar in superelastic, body-temperature shape-memory, and nonsuperelastic NiTi wires. Differences in bending properties for the NiTi orthodontic wires at room temperature and 37° C are due to the relative proportions of the metallurgical phases in the microstructures

Genetic selection for feed intake and efficiency in beef cattle

2019 Fall.Includes bibliographical references.To view the abstract, please see the full text of the document

Iodine, a Factor in Feeding Young Growing Swine

Iodine is now generally believed to be absolutely essential for the proper growth and development of the mammalian organism, and its use in animal feeding is becoming more and more general, particularly in goitrous regions

Supplemental Specialty Feeds for Making 225 Pound Pigs on Pasture

The results of pig feeding tests, conducted in 1920–21 with specialty or commercial feeds by the Animal Husbandry Section of the Iowa Agricultural Experiment Station, have been so grossly and persistently misrepresented by one company in particular that this circular Is Is· sued to present the complete figures. The misrepresentation con· slated In using only a part of the experimental figures, thus giving an Incorrect interpretation of the data secured in the test

Feeding the Brood Sow

The brood sows represent in a large measure the backbone or the swine herd, hence their correct nutrition and handling are of dollars and cents Importance

2019 James R. Browning Distinguished Lecture in Law, Holding the Delicate Balance Steady and True : The History of FISA\u27s Grand Bargain

The Honorable Richard C. Tallman and his career law clerk Tania M. Culbertson explain what led to the passage of the Foreign Intelligence Surveillance Act ( FISA ) and its creation of the FISA courts, and describe the grand bargain that was struck between our three branches of government when creating FISA\u27s judicial review procedures over domestic espionage and counter-terrorism investigations. Their hope is to leave you with a keener understanding of how we have arrived at where we are today, and how the judiciary understands its oversight role within FISA\u27s statutory framework under our Constitution