38 research outputs found
Noncontact temperature measurement in glass and other transparent materials
The relationship between the optical properties of glass and temperature measurements in it by radiation pyrometry are described. Equations for the calculation of emissivity are presented and the transmittance, surface reflection and absorption characteristics of glass are defined. Recommendations are given regarding the selection of pyrometer wavelength sensitivity and the use of a blackbody radiator
Climate Change Meets the Law of the Horse
The climate change policy debate has only recently turned its full attention to adaptation - how to address the impacts of climate change we have already begun to experience and that will likely increase over time. Legal scholars have in turn begun to explore how the many different fields of law will and should respond. During this nascent period, one overarching question has gone unexamined: how will the legal system as a whole organize around climate change adaptation? Will a new distinct field of climate change adaptation law and policy emerge, or will legal institutions simply work away at the problem through unrelated, duly self-contained fields, as in the famous Law of the Horse? This Article is the first to examine that question comprehensively, to move beyond thinking about the law and climate change adaptation to consider the law of climate change adaptation. Part I of the Article lays out our methodological premises and approach. Using a model we call Stationarity Assessment, Part I explores how legal fields are structured and sustained based on assumptions about the variability of natural, social, and economic conditions, and how disruptions to that regime of variability can lead to the emergence of new fields of law and policy. Case studies of environmental law and environmental justice demonstrate the model’s predictive power for the formation of new distinct legal regimes. Part II applies the Stationarity Assessment model to the topic of climate change adaptation, using a case study of a hypothetical coastal region and the potential for climate change impacts to disrupt relevant legal doctrines and institutions. We find that most fields of law appear capable of adapting effectively to climate change. In other words, without some active intervention, we expect the law and policy of climate change adaptation to follow the path of the Law of the Horse - a collection of fields independently adapting to climate change - rather than organically coalescing into a new distinct field. Part III explores why, notwithstanding this conclusion, it may still be desirable to seek a different trajectory. Focusing on the likelihood of systemic adaptation decisions with perverse, harmful results, we identify the potential benefits offered by intervening to shape a new and distinct field of climate change adaptation law and policy. Part IV then identifies the contours of such a field, exploring the distinct purposes of reducing vulnerability, ensuring resiliency, and safeguarding equity. These features provide the normative policy components for a law of climate change adaptation that would be more than just a Law of the Horse. This new field would not replace or supplant any existing field, however, as environmental law did with regard to nuisance law, and it would not be dominated by substantive doctrine. Rather, like the field of environmental justice, this new legal regime would serve as a holistic overlay across other fields to ensure more efficient, effective, and just climate change adaptation solutions
Hot-pressed hydroxylapatite/monoclinic zirconia composites with improved mechanical properties
Composites of hydroxylapatite (HA) and monoclinic zirconia were hot-pressed at 1100 degrees C and 1200 degrees C under vacuum to study the phase transformations and the mechanical properties. X-ray diffraction results showed a higher phase transformation from monoclinic-ZrO2 to tetragonal-ZrO2 when the sintering temperature increased from 1100 degrees C to 1200 degrees C. HA decomposed faster when the amount of ZrO2 in the composites increased. Moreover, small amount of alpha-TCP and CaZrO3 was observed in the composites hot-pressed at 1200 degrees C. Hot-pressing at 1100 degrees C resulted in better mechanical properties than the hot-pressing at 1200 degrees C because of less reaction between HA and zirconia at 1100 degrees C. 40 wt% monoclinic zirconia and HA composite hot-pressed at 1100 degrees C resulted in promising mechanical properties which are 6.5 GPa of Vickers mu-hardness, 2.23 MPa root m of fracture toughness, and 66 MPa of diametral strength
Effect of MgF2 on hot pressed hydroxylapatite and monoclinic zirconia composites
Hydroxylapatite (HA) has been widely used in biomedical applications because of its excellent biocompatibility in the human body. A total of 25 wt% monoclinic (m) zirconia-HA composites (with and without 5 wt% MgF2) were synthesized to investigate their mechanical properties and phase stability. In HA-m-ZrO2 composites, HA and m-ZrO2 reacted to form CaZrO3 when there was no F- present in the composite and M-ZrO2 partially transformed to tetragonal ZrO2. When MgF2 was added into the system, it improved the thermal stability of the phases, densification, hardness, and fracture toughness of the composites and it caused the m-ZrO2 to transform completely to t-ZrO2 by incorporating the Mg2+ ions present in MgF2 in the ZrO2. Moreover, the stability of HA was improved by incorporating the F- ions from MgF2 in place of OH- ions in HA. Substitution of OH- by F- ions was verified by the change in HA's hexagonal lattice parameters. A fracture toughness of 2.0 MPa root m was calculated for the composite containing MgF2
Effect of AlF3, CaF2 and MgF2 on hot-pressed hydroxyapatite-nanophase alpha-alumina composites
Nanophase alpha-alumina and hydroxyapatite composites (with and without 5 wt% AlF3, CaF2 or MgF2 added separately) were hot pressed at 1100 degrees C and 1200 degrees C to investigate their mechanical properties and phase stability. Hydroxyapatite slightly decomposed to tri-calciurn-phosphate when there was no F- present. With the addition of AlF3, CaF2 or MgF2 into the composite, it improved its thermal stability and mechanical properties. Substitution of OH- by F- ions in hydroxyapatite was verified by the change in hydroxyapatite's hexagonal lattice parameters and unit cell volume. A fracture toughness of 2.8 MPa root m and mu-hardness of 8.25 GPa were calculated for the composite containing CaF2 after the hot pressing at 1200 degrees C
Effect of ZrF4 on hot-pressed hydroxyapatite/monoclinic zirconia composites
Composites of 25 wt.% monoclinic zirconia and 75 wt.% hydroxyapatite (HA) (with and without 5 wt.% ZrF4) were hot pressed to investigate their mechanical properties and phase stability. HA decomposed to tricalcium. phosphate when there was no ZrF4 present. Addition of ZrF4 into the composite improved its thermal stability and mechanical properties. Substitution of OH- by F- ions was verified by the change in HA's hexagonal lattice parameters. A fracture toughness of 2.1 MPa root m and microhardness of 6.9 GPa were calculated for the composite containing ZrF4. (c) 2006 Published by Elsevier Ltd. on behalf of Acta Materialia, Inc