Processes for Nanomachining Using Carbon Nanotubes

Novel methods and devices for nanomachining a desired pattern on a surface of a conductive workpiece are disclosed. In one aspect, the method comprises using an electron beam emitted from one or more nanotubes to evaporate nanoscale quantities of material from the workpiece surface. The surface of the workpiece to be machined may be excited to a threshold energy to reduce the amount of power required to be emitted by the nanotube. In another aspect, a device is described for nanomachining a desired pattern on a surface of a conductive workpiece, comprising a vessel capable of sustaining a vacuum, a leveling support, a nanopositioning stage, and a laser for heating the workpiece. A nanotool is provided comprising at least one nanotube supported on an electrically conductive base, adapted to emit an electron beam for evaporating material from an electrically conductive workpiece

Effect of Fat and Casein Particles in Milk on the Scattering of Elliptically Polarized Light

In this article, we present an experimental approach to determine the milk fat content using scattered light intensity profiles. The elements of the scattering (Mueller) matrix have been shown to provide valuable information about variation of the optical properties of scattering particles. The scattering behavior of fat and casein in terms of the scattering matrix elements was experimentally determined for milk with varying fat levels ranging from 0.05 wt% (skim) to 3.20 wt% (whole). Three of the scattering Mueller matrix elements, specifically S11, S12/S11, and S33/S11, were found to be sensitive to the number of fat particles in milk. These results indicate that it should be possible to develop a reliable sensor based on the measurement of these scattering elements, which will allow for the development of a robust, in-line sensor to be used in food processing. In addition, an attempt was made to model the phenomena using a relatively simple approach based on single scattering with a size distribution. The disagreement between the model and experiments suggests that a more comprehensive model is needed which can account for multiple scattering

Radiation Modulator System

A radiation modulator system and related method for actively controlling a flame in a combustion system are provided. The system includes a plurality of radiation modulators positioned adjacent the flame. A sensor arrangement is provided for sensing combustion characteristics of the flame and generating a sensor signal representative of the combustion characteristics. The sensor signal is received in a computer which then generates a control signal for transmission to a linkage arrangement which provides for the repositioning of the radiation modulators. Thus, the flame is actively controlled by continually repositioning the modulators in response to the sensor signal and the control signal. The related method broadly includes the steps of: (1) positioning the radiation modulators adjacent the flame; (2) sensing combustion characteristics of the flame; and (3) repositioning the radiation modulators responsive to the combustion characteristics

Fiber Optic Sensor Response to High Levels of Fat in Cream

A light backscatter technique using optical fibers to deliver and receive light was investigated for measuring the milkfat content of unhomogenized cream. Light backscatter through cream at wavelengths of 450 to 900 nm was measured for fiber separation distances from 2 to 6.5 mm and for cream containing 10 to ~40 weight percent (wt%) milkfat. Unhomogenized cream (~40 wt% milkfat) was mixed with skim milk (~0.05 wt% milkfat) to yield samples with five different milkfat levels. Three optical response models were tested for correlation with milkfat content: one using the light intensity measurement at a single separation distance, the second using the ratio of the light intensity at two distances, and a third using the light intensity as a function of separation distance based on the backscatter of light in a particulate solution. The calibration equations from all three methods were used to predict milkfat content in the evaluation samples with root mean square errors (RMSEs) of 1.5 to 2.0 wt%. Statistical analysis did not find a significant difference between the three methods. For simplicity, using the ratio of the intensities measured and two different separation distances is attractive for further sensor design

Bringing sustainability to the heart of a university through teaching, research and service

In this short paper, we summarize our targeted efforts at Ozyegin University in Istanbul, Turkey for establishing a sustainable research, teaching and learning environment. The University is striving to have highest level impact on sustainable education, energy, architecture, built environment, business and life-long learning practices. The strategic plan of the University puts the principles of sustainability at the cornerstone of its efforts, with the aim to aspire not only our students and staff, but also the community at large

Analysis of Sustainable Materials for Radiative Cooling Potential of Building Surfaces

The main goal of this paper is to explore the radiative cooling and solar heating potential of several materials for the built environment, based on their spectrally-selective properties. A material for solar heating, should have high spectral emissivity/absorptivity in the solar radiation band (within the wavelength range of 0.2–2 μm), and low emissivity/absorptivity at longer wavelengths. Radiative cooling applications require high spectral emissivity/absorptivity, within the atmospheric window band (8–13 μm), and a low emissivity/absorptivity in other bands. UV-Vis spectrophotometer and FTIR spectroscopy, are used to measure, the spectral absorption/emission spectra of six different types of materials. To evaluate the radiative cooling potential of the samples, the power of cooling is calculated. Heat transfer through most materials is not just a surface phenomenon, but it also needs a volumetric analysis. Therefore, a coupled radiation and conduction heat transfer analysis is used. Results are discussed for the selection of the best materials, for different applications on building surfaces

A Transdisciplinary Approach and Design Thinking Methodology: For Applications to Complex Problems and Energy Transition

In this paper, we outline a transdisciplinary approach and design thinking methodology (TADTM) to tackle complex problems. Our premise is that these problems need a fundamental understanding of technological solutions and those for human interactions, business operations, financing, socioeconomic governance, legislation, and regulations. They must be approached by different decisionmakers from different disciplines to establish seamless interactions and structured teamwork. In this regard, we emphasize the need for a transdisciplinary framework that accounts for personal preferences based on human behavior as well as the traditional interdisciplinary frameworks. To test and prove our hypothesis, three case studies are discussed. Case Study 1 is based on our studies at a major medical establishment, and Case Study 2 is about the integrated engineering and architecture approach we used at our university campus. Case Study 3 is based on an ongoing project to lead industrial corporations to change their energy policies with practical energy efficiency measures and by adapting renewable/alternative energy adaptations for their operations. Developing creative solutions and strategies to decrease atmospheric greenhouse gas emissions requires such an energy transition framework and should involve every person, company, entity, and all governments. It can only be achieved with efforts on both local and global levels, which needs to convince (a) industries to change their traditional operation modalities, (b) people to alter their consumption behaviors, and (c) governments to change their rules, regulations, and incentives. The complexity and magnitude of this enormous task demand the coordination and collaboration of all stakeholders, as well as the need for technological innovations

A biomimicry design for nanoscale radiative cooling applications inspired by Morpho didius butterfly

Abstract In nature, novel colors and patterns have evolved in various species for survival, recognizability or mating purposes. Investigations of the morphology of various butterfly wings have shown that in addition to the pigmentation, micro and nanostructures within the wings have also allowed better communication systems and the pheromone-producing organs which are the main regulators of the temperature within butterfly wings. Within the blue spectrum (450–495 nm), Morpho didius butterfly exhibit iridescence in their structure-based wings’ color. Inspired by the rich physics behind this concept, we present a designer metamaterial system that has the potential to be used for near-field radiative cooling applications. This biomimicry design involves SiC palm tree-like structures placed in close proximity of a thin film in a vacuum environment separated by nanoscale gaps. The near-field energy exchange is enhanced significantly by decreasing the dimensions of the tree and rotating the free-standing structure by 90 degrees clockwise and bringing it to the close proximity of a second thin film. This exchange is calculated by using newly developed near-field radiative transfer finite difference time domain (NF-RT-FDTD) algorithm. Several orders of enhancement of near-field heat flux within the infrared atmospheric window (8–13 μm bandwidth) are achieved. This spectrally selective enhancement is associated with the geometric variations, the spatial location of the source of excitation and the material characteristics, and can be tuned to tailor strong radiative cooling mechanisms

Thermal radiation heat transfer

Providing a comprehensive overview of the radiative behavior and properties of materials, the fifth edition of this classic textbook describes the physics of radiative heat transfer, development of relevant analysis methods, and associated mathematical and numerical techniques. Retaining the salient features and fundamental coverage that have made it popular, Thermal Radiation Heat Transfer, Fifth Edition has been carefully streamlined to omit superfluous material, yet enhanced to update information with extensive references. Includes four new chapters on Inverse Methods, Electromagnetic Theory, Scattering and Absorption by Particles, and Near-Field Radiative Transfer Keeping pace with significant developments, this book begins by addressing the radiative properties of blackbody and opaque materials, and how they are predicted using electromagnetic theory and obtained through measurements. It discusses radiative exchange in enclosures without any radiating medium between the surfaces-and where heat conduction is included within the boundaries. The book also covers the radiative properties of gases and addresses energy exchange when gases and other materials interact with radiative energy, as occurs in furnaces. To make this challenging subject matter easily understandable for students, the authors have revised and reorganized this textbook to produce a streamlined, practical learning tool that: Applies the common nomenclature adopted by the major heat transfer journals Consolidates past material, reincorporating much of the previous text into appendices Provides an updated, expanded, and alphabetized collection of references, assembling them in one appendix Offers a helpful list of symbols With worked-out examples, chapter-end homework problems, and other useful learning features, such as concluding remarks and historical notes, this new edition continues its tradition of serving both as a comprehensive textbook for those studying and applying radiative transfer, and as a repository of vital literary references for the serious researcher.Introduction to Radiative TransferImportance of Thermal Radiation in EngineeringThermal Energy TransferThermal Radiative TransferRadiative Energy Exchange and Radiative IntensityCharacteristics of EmissionRadiative Energy Loss and Gain Along a Line-of-SightRadiative Transfer EquationRadiative Transfer in Nonparticipating EnclosuresDefinitions of Properties at InterfacesEmissivityAbsorptivityReflectivityTransmissivity at an InterfaceRelations among Reflectivity, Absorptivity, Emissivity, and TransmissivityRadiative Properties of Opaque MaterialsElectromagnetic Wave Theory PredictionsExtension