scholarly journals Experimental measurement of local high temperature at the surface of gold nanorods using doped ZnGa2O4 as nanothermometers

2021 ◽  
Author(s):  
Corinne Chaneac ◽  
Bruno Viana ◽  
Estelle Glais ◽  
Agnès Maître
Keyword(s):  
High Temperature ◽  
Metal Nanoparticles ◽  
Gold Nanorods ◽  
Experimental Measurement ◽  
Environmental Condition ◽  
Heat Measurement ◽  
Photo Catalysis ◽  
Further Development

Heat measurement induced by photoexcitation of a plasmonic metal nanoparticles assembly in environmental condition is of primary importance for the further development of applications in the field of (photo)catalysis, nanoelectronic...

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

scholarly journals Environmental effects on photosynthetic capacity of bean genotypes

2004 ◽  
Vol 39 (7) ◽  
pp. 615-623 ◽  
Author(s):  
Rafael Vasconcelos Ribeiro ◽  
Mauro Guida dos Santos ◽  
Gustavo Maia Souza ◽  
Eduardo Caruso Machado ◽  
Ricardo Ferraz de Oliveira ◽  
...  
Keyword(s):  
High Temperature ◽  
Natural Condition ◽  
Temperature Effects ◽  
Environmental Changes ◽  
Photosynthetic Capacity ◽  
Photosynthetic Apparatus ◽  
Co2 Assimilation ◽  
Fluorescence Yield ◽  
Environmental Condition ◽  
Response Curves

Photosynthetic responses to daily environmental changes were studied in bean (Phaseolus vulgaris L.) genotypes 'Carioca', 'Ouro Negro', and Guarumbé. Light response curves of CO2 assimilation and stomatal conductance (g s) were also evaluated under controlled (optimum) environmental condition. Under this condition, CO2 assimilation of 'Carioca' was not saturated at 2,000 µmol m-2 s-1, whereas Guarumbé and 'Ouro Negro' exhibited different levels of light saturation. All genotypes showed dynamic photoinhibition and reversible increase in the minimum chlorophyll fluorescence yield under natural condition, as well as lower photosynthetic capacity when compared with optimum environmental condition. Since differences in g s were not observed between natural and controlled conditions for Guarumbé and 'Ouro Negro', the lower photosynthetic capacity of these genotypes under natural condition seems to be caused by high temperature effects on biochemical reactions, as suggested by increased alternative electron sinks. The highest g s values of 'Carioca' were observed at controlled condition, providing evidences that reduction of photosynthetic capacity at natural condition was due to low g s in addition to the high temperature effects on the photosynthetic apparatus. 'Carioca' exhibited the highest photosynthetic rates under optimum environmental condition, and was more affected by daily changes of air temperature and leaf-to-air vapor pressure difference.

A robust procedure for the functionalization of gold nanorods and noble metal nanoparticles

2009 ◽  
pp. 1724 ◽  
Author(s):  
Benjamin Thierry ◽  
Jane Ng ◽  
Tina Krieg ◽  
Hans J. Griesser
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Gold Nanorods ◽  
Noble Metal Nanoparticles

INVESTIGATION OF THE GROWTH AND DISSOLUTION OF THE OXIDE PHASE ON TITANIUM WHEN HEATING DURING ITS HIGH-TEMPERATURE TREATMENT

2021 ◽  
pp. 107-112
Author(s):  
И.Л. Батаронов ◽  
В.В. Пешков ◽  
В.Ф. Селиванов ◽  
В.В. Шурупов
Keyword(s):  
High Temperature ◽  
Oxide Films ◽  
Oxide Phase ◽  
Temperature Treatment ◽  
Physical Contact ◽  
High Temperature Treatment ◽  
Diffusion Welding ◽  
Contact Surfaces ◽  
Welding Pressure ◽  
Further Development

Получение прочных диффузионно-сварных соединений поверхностно активных металлов связано с ростом и растворением оксидных пленок на контактных поверхностях. При этом процесс образования оксидов может протекать по различным механизмам. При высокотемпературном нагреве титановых сплавов при диффузионной сварке, реализуемой в вакууме, имеет место активное взаимодействие металла с остаточными газами вакуумированного пространства. Образующиеся оксидные пленки препятствуют физическому контакту и дальнейшему развитию качественного неразъемного соединения деталей. Ввиду быстротечности роста и растворения окислов на соединяемых поверхностях и невозможности в динамике количественно оценить их величину предложено физико-математическое моделирование процесса роста и растворения оксидов, позволяющее определить время и температуру нагрева поверхностей, при которых возможно приложение сварочного давления к контактным поверхностям, свободным от оксидов. Построенные на основе полученных математических выражений графики позволяют определить характер изменения толщины оксидной пленки. На основании анализа графических зависимостей установлено, что уменьшение толщины оксидов, вплоть до их практически окончательного удаления, зависит от скорости нагрева. При большей скорости нарастания температуры образуется меньший слой оксидов. Такая же ситуация прослеживается при увеличении степени вакуумирования в герметичной камере. Для практических задач установленные математические и графические данные позволяют определить технологические схемы и условия, при которых становится возможным сведение в контакт соединяемых поверхностей деталей из титана, когда их поверхности деблокированы от оксидов, что, в свою очередь, определяет качество и надежность диффузионно-сварного соединения The production of strong diffusion-welded joints of surfactants is associated with the growth and dissolution of oxide films on the contact surfaces. In this case, the process of formation of oxides can proceed by various mechanisms. At high-temperature heating of titanium alloys during diffusion welding, implemented in a vacuum, there is an active interaction of the metal with the residual gases of the evacuated space. The resulting oxide films prevent physical contact and the further development of a high-quality solid connection of parts. Due to the transience of the growth and dissolution of oxides on the connected surfaces and the inability to quantify their value in dynamics, we proposed a physical and mathematical modeling of the process of growth and dissolution of oxides, which allows us to determine the time and temperature of heating surfaces at which welding pressure can be applied to the contact surfaces free of oxides. Based on the analysis of graphical dependencies, we found that the reduction in the thickness of the oxides, up to their almost final removal, depends on the heating rate. At a higher rate of temperature rise, a smaller layer of oxides is formed. The same situation is observed when increasing the degree of vacuuming in a sealed chamber. For practical tasks, the established mathematical and graphical data allow us to determine the technological schemes and conditions under which it becomes possible to bring the connected surfaces of titanium parts into contact when their surfaces are unblocked from oxides, which, in turn, determines the quality and reliability of the diffusion-welded joint

Experimental measurement of oxygen catalytic recombination flux on ceramic materials at high temperature

1995 ◽  
Vol 27/28 (3) ◽  
pp. 287-291
Author(s):  
Marianne Balat ◽  
Marilyne Czerniak ◽  
Marc Geerts ◽  
Claude Dupuy
Keyword(s):  
High Temperature ◽  
Experimental Measurement ◽  
Ceramic Materials ◽  
Catalytic Recombination

Thermal Stability of Gold Nanorods for High-Temperature Plasmonic Sensing

2013 ◽  
Vol 117 (22) ◽  
pp. 11718-11724 ◽  
Author(s):  
Nicholas A. Joy ◽  
Brian K. Janiszewski ◽  
Steven Novak ◽  
Timothy W. Johnson ◽  
Sang-Hyun Oh ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Gold Nanorods ◽  
Plasmonic Sensing ◽  
Thermal Stability Of

Pyrometric Temperature Measurements on Solar Thermal High Temperature Receivers

2006 ◽  
Vol 128 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Markus Pfänder ◽  
Eckhard Lüpfert ◽  
Peter Heller
Keyword(s):  
High Temperature ◽  
Solar Radiation ◽  
Solar Thermal ◽  
Absorption Bands ◽  
Atmospheric Absorption ◽  
Efficient Operation ◽  
Solar Blind ◽  
Measurement Signal ◽  
Spectral Ranges ◽  
Further Development

The knowledge of the absorber surface temperature distribution is essential for efficient operation and further development of solar thermal high temperature receivers. However, the concentrated solar radiation makes it difficult to determine the temperature on irradiated surfaces. Contact thermometry is not appropriate and pyrometric measurements are distorted by the reflected solar radiation. The measurement in solar-blind spectral ranges offers a possible solution by eliminating the reflected solar radiation from the measurement signal. The paper shows that besides the incoming solar radiation and the absorber emittance, the bi-directional reflection properties and the temperature of the object are determining for the required selectivity of the spectral filter. Atmospheric absorption affects the solar blind pyrometric measurements in absorption bands of CO2 and water vapor. The deviation of temperature measurement due to atmospheric absorption is quantified and the possibilities and limitations of accounting for the atmospheric absorption with models based on radiation transfer calculations are discussed.

Sign in / Sign up

Export Citation Format

Share Document