bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of fan‐pattern spray nozzle wear using scanning electron microscopy
Authors: Krause C. R. , Reichard D. L. , Zhu H. , Brazee R. D. , Fox R. D. , Ozkan H. E. 
Published: June 2010

AbstractWorn nozzles on spray equipment severely affect the efficiency of crop management systems while causing unnecessary pesticide contamination of non target areas. Scanning electron microscopy (SEM) that has been applied for direct measurement of pesticide deposition, was used to observe worn and unused brass and stainless steel fan‐pattern spray nozzles. Wear and other changes were observed in both nozzle materials. Scanning electron microscopy can provide nozzle manufacturers with greater insight and needed information on nozzle mechanics to improve performance. More reliable delivery of pesticide spray should enhance integrated pest and disease management and crop protection for growers.
Correction for piezoelectric creep in scanning probe microscopy images using polynomial mapping
Authors: Trawick Matthew L. , Megens Mischa , Angelescu Dan E. , Harrison Christopher , Vega Daniel A. , Chaikin Paul M. , Register Richard A. , Adamson Douglas H. 
Published: June 2010

AbstractWe describe a method for using polynomial mapping to correct scanning probe microscope images for distortion due to piezoelectric creep. Because such distortion varies from image to image, this method can be used when the actual locations of some features within an image are known absolutely, or in a series of images in which the actual locations of some features are known not to vary. While the general case of polynomial mapping of degree N requires the determination of 2(N+1)2 matrix elements by regression, we find that by understanding the mechanism by which piezoelectric creep distorts scanning probe microscope images, we can fix most of these coefficients at 0 or 1 a priori, leaving only 2(N+1) coefficients to be determined by regression. We describe our implementation of this strategy using the Interactive Data Language (IDL) programming language, and demonstrate our technique on a series of atomic force microscopy (AFM) images of diblock copolymer microdomains. Using our simplified scheme, we are able to reduce the effects of distortion in an AFM image from 5% of the scan width to a single pixel, using only five reference points.
Scanning Electron Microscopy Analysis of Corrosion Degradation on Tinplate Substrates
Authors: Zumelzu E. , Cabezas C. , Vera A. 
Published: June 2010

AbstractThe degradation of electrolytic tinplate used in food containers was analysed and evaluated, using scanning electron microscopy and electrochemical measurements of microcorrosion and ion dissolution by atomic absorption to prevent food contamination caused by metal traces and to increase the durability of such tinplates.
Rime and graupel: Description and characterization as revealed by low‐temperature scanning electron microscopy
Authors: Rango Albert , Foster James , Josberger Edward G. , Erbe Eric F. , Wergin William P. , Pooley Christopher 
Published: June 2010

AbstractSnow crystals, which form by vapor deposition, occasionally come in contact with supercooled cloud droplets during their formation and descent. When this occurs, the droplets adhere and freeze to the snow crystals in a process known as accretion. During the early stages of accretion, discrete snow crystals exhibiting frozen cloud droplets are referred to as rime. If this process continues, the snow crystal may become completely engulfed in frozen cloud droplets. The resulting particle is known as graupel. Light microscopic investigations have studied rime and graupel for nearly 100 years. However, the limiting resolution and depth of field associated with the light microscope have prevented detailed descriptions of the microscopic cloud droplets and the three‐dimensional topography of the rime and graupel particles. This study uses low‐temperature scanning electron microscopy to characterize the frozen precipitates that are commonly known as rime and graupel. Rime, consisting of frozen cloud droplets, is observed on all types of snow crystals including needles, columns, plates, and dendrites. The droplets, which vary in size from 10 to 100 μm, frequently accumulate along one face of a single snow crystal, but are found more randomly distributed on aggregations consisting of two or more snow crystals (snowflakes). The early stages of riming are characterized by the presence of frozen cloud droplets that appear as a layer of flattened hemispheres on the surface of the snow crystal. As this process continues, the cloud droplets appear more sinuous and elongate as they contact and freeze to the rimed crystals. The advanced stages of this process result in graupel, a particle 1 to 3 mm across, composed of hundreds of frozen cloud droplets interspersed with considerable air spaces; the original snow crystal is no longer discernible. This study increases our knowledge about the process and characteristics of riming and suggests that the initial appearance of the flattened hemispheres may result from impact of the leading face of the snow crystal with cloud droplets. The elongated and sinuous configurations of frozen cloud droplets that are encountered on the more advanced stages suggest that aerodynamic forces propel cloud droplets to the trailing face of the descending crystal where they make contact and freeze.
Tools and Procedures for Quantitative Microbeam Isotope Ratio Imaging by Secondary Ion Mass Spectrometry
Authors: Gillen Greg , Bright David 
Published: June 2010

AbstractIn this work we demonstrate the use of secondary ion mass spectrometry (SIMS) combined with the Lispix image processing program (Bright 1995) to generate quantitative isotope ratio images from a test sample of a calcium‐aluminum rich inclusion from the Allende meteorite that is known to contain discrete mineral grains with perturbed Mg isotopic ratios. Using 19.5 keV impact O‐ primary ion bombardment and detection of positive secondary ions, microbeam imaging SIMS has allowed us to identify, from the isotope ratio images, enrichments in the 26Mg/24Mg isotope ratio of approximately 5‐15% in selected mineral grains. Using custom image processing software, each isotopic ratio image is corrected on an individual pixel basis for a number of factors including detector dead‐time, mass bias effects, and isobaric interferences. We have developed procedures for correlating the isotopic images with polarized optical microscopy so that targeted mineral grains could be identified for further SIMS analysis. Finally, additional image processing tools have been developed to allow for pixel‐by‐pixel evaluation of the influence of detector dead‐time and count rate errors on the isotopic ratio images and for correlation of the isotopic images with elemental distribution maps.
MgATP‐induced conformational changes in a single myosin molecule observed by atomic force microscopy: Periodicity of substructures in myosin rods
Authors: Taniguchi Mieko , Suzuki Shigehito , Yamane Takashi , Matsumoto Osamu , Okuda Ayumu , Taga Tooru , Nishino Yasunobu 
Published: June 2010

AbstractThis paper discusses the conformational changes in a single myosin molecule directly observed using atomic force microscopy (AFM). The myosin molecules were pretreated in rigor solutions without MgATP or in relaxed solutions with various concentrations of MgATP. The images of these molecules were obtained using a tapping mode AFM. The results indicate that the orientation of the myosin's heads and tail strongly depend on the MgATP concentration. Without using MgATP, almost all of the myosin molecules are in the extended form; however, when MgATP is used, the molecules bend according to the level of MgATP concentration. The mean‐square end‐to‐end distance of the myosin molecules is significantly shorter with p[MgATP] = 4 than with p[MgATP] = 6. The rod region did not show the same level of intensity along their length in the extended form. The rods exhibited clusters of discontinuity, which were identified as substructures. The size of these substructures change at intervals that are multiples of 14.3‐14.5 nm, which reflects the periodicity of the α;‐helical coiled coils. The substructure clusters also correspond to the myosin cross‐bridge spacing in muscles (14.3 or 43 nm). These results suggest that the myosin's head bends in conjunction with the bending or tilting in the helical substructures. Conformational changes of the myosin molecule induced by MgATP seem to mimic the molecular motions in a muscle's force generation process.
Software acceleration techniques for the simulation of scanning electron microscope images
Authors: Seeger Adam , Fretzagias Charalampos , Taylor Russell 
Published: June 2010

AbstractA scanning electron microscope (SEM) simulator was developed based on the models used in the MONSEL software. This simulator extends earlier work by introducing an object‐oriented framework and adding optimization methods based on precomputation of electron trajectories. Several optimizations enable speedup by factors of 5–100 on a single processor over unoptimized simulations without introducing additional approximations. The speedup for a particular surface depends on the selfsimilarity of the surface at the scale of the electron penetration depth. We further accelerate by parallelizing the calculations for a total speedup of about 100‐2000 on 30 processors. The goal of this work was to create a system capable of simulating a quantitatively accurate SEM image of a relatively unconstrained surface. Results of this work include simulation software, optimization algorithms, performance measurements with various optimizations, and examples of simulated images.
A microcantilever‐based pathogen detector
Authors: Weeks B. L. , Camarero J. , Noy A. , Miller A. E. , De Yoreo J. J. , Stanker L. 
Published: June 2010

AbstractThe ability to detect small amounts of materials, especially bacterial organisms, is important for medical diagnostics and national security issues. Engineered micromechanical systems provide one approach for constructing multifunctional, highly sensitive, real‐time, immunospecific biological detectors. We present qualitative detection of specific Salmonella enterica strains using a functionalized silicon nitride microcantilever. Detection is achieved due to a change in the surface stress on the cantilever surface in situ upon binding of a small number of bacteria. Scanning electron micrographs indicate that less than 25 adsorbed bacteria are required for detection.
Electron backscatter diffraction characterization of inlaid cu lines for interconnect applications
Authors: Field D. P. , Muppidi T. , Sanchez J. E. 
Published: June 2010

AbstractAutomated electron backscatter diffraction (EBSD) techniques have been used to characterize the microstructures of thin films for the past decade or so. The recent change in strategy from an aluminum‐based interconnect structure in integrated circuits to one based on copper has necessitated the development of new fabrication procedures. Along with new processes, complete characterization of the microstructures is imperative for improving manufacturability of the Cu interconnect lines and in‐service reliability. Electron backscatter diffraction has been adopted as an important characterization tool in this effort. Cu microstructures vary dramatically as a function of processing conditions, including electroplating bath chemistry, sublayer material, stacking sequence of sublayers, annealing conditions, and line widths and depths. Crystallographic textures and grain size and grain boundary character distributions, all of which may influence manufacturability and reliability of interconnect lines, are ideally characterized using EBSD. The present discussion presents some results showing structural dependence upon processing parameters. In addition, the authors identify an in‐plane orientation preference in inlaid Cu lines {111} normal to the line surface and 〈110〉 aligned with the line direction. This relationship tends to strengthen as the line width decreases.
New application of variable‐pressure/environmental microscopy to semiconductor inspection and metrology
Authors: Postek Michael T. , Vladár András E. 
Published: June 2010

AbstractVariable‐pressure/environmental scanning electron microscopy has been used for successful investigation binary and phase‐shifting chromium on quartz optical photomasks. This methodology was also applied to patterned 193 nm photoresist structures. The application of this methodology to semiconductor metrology is new because of the recent availability of variable‐pressure scanning electron microscopy (SEM) instrumentation equipped with high‐resolution, high‐signal, thermally assisted field emission technology in conjunction with large chamber and sample transfer capabilities. The variable‐pressure SEM methodology employs a gaseous environment around the sample to help diminish the charge build‐up that occurs under irradiation with the electron beam. Although very desirable for the charge reduction in many biological, pharmaceutical, and food applications, this methodology has not been employed for semiconductor photomask or wafer metrology until now. This is a new application of this technology to this area, and it shows great promise in inspection, imaging, and metrology in a charge‐free operational mode. For accurate metrology, variable‐pressure SEM methodology also affords a path that minimizes, if not eliminates, the need for charge modeling. This paper presents some of the early results in the variable‐pressure SEM metrology of photomask and photoresist structures.
Mathematical modeling of human secondary osteons
Authors: Ascenzi Maria‐Grazia , Kabo J. Michael , Andreuzzi Marta 
Published: June 2010

AbstractThis investigation explores the structural dimensions and patterns within single secondary osteons, with consideration of their biological variation. New data from images obtained previously of osteons observed through linearly polarized light, electron microscopy, and micro‐x‐ray, combined with recent findings on lamellae by circularly polarized light, confocal microscopy, synchrotron x‐ray diffraction, and micro‐x‐ray, provide the basis for novel computerized models of single osteons and single lamellae. The novelty of such models is the concurrent representation of (1) collagen‐hydroxyapatite orientation, (2) relative hydroxyapatite percentage, (3) distributions of osteocytes' lacunae and canaliculae, and (4) biological variations in dimensions of the relevant structures. The mathematical software Maple realizes the computerized models. While the parts of the models are constructed on a personal computer, the voluminous data associated with the representation of lacunar and canalicular distributions require a supercomputer for assembly of the models and final analysis. The programming used to define the models affords the option to randomize the dimensional specifications of osteons, lamellae, lacunae, and canaliculae within the experimentally observed numeric ranges and distributions. Through this option, the program can operate so that each run of the file produces a unique random model within the observed biological variations. The program can also be run to implement specific dimensional requirements. The modeling has applications in the microstructural study of fracture propagation and remodeling, as well as in the simulation of mechanical testing. The approach taken here is of wide application and could be of value in other areas of microscopy such as scanning electron microscopy, microcomputerized tomography scan, and magnetic resonance imaging on cancellous bone structures.
Effect of shot noise and secondary emission noise in scanning electron microscope images
Authors: Sim K. S. , Thong J. T. L. , Phang J. C. H. 
Published: June 2010

AbstractThe effect of shot noise and emission noise due to materials that have different emission properties was simulated. Local variations in emission properties affect the overall signal‐to‐noise ratio (SNR) value of the scanning electron microscope image. In the case in which emission noise is assumed to be absent, the image SNRs for silicon and gold on a black background are identical. This is because only shot noise in the primary beam affects the SNRs, irrespective of the assumed noiseless secondary electron emission or backscattered electron emission processes. The addition of secondary emission noise degrades the SNR. Materials with higher secondary electron yield and backscattering electron yield give rise to higher SNR. For images formed from two types of material, the contrast of the image is lower. The reduction in image signal reduces the overall image SNR. As expected, large differences in δ or η give rise to higher SNR images.
Contributions of scanning electron microscopy to the assessment of the effectiveness of stone conservation treatments
Authors: de Buergo M. Alvarez , Fort R. , Gomez‐Heras M. 
Published: June 2010

AbstractThe efficiency of 16 products (with consolidating and/or water‐repellency effects) applied to granites and limestones have been assessed by means of scanning electron microscopy (SEM). The technique offers the possibility of observing the porous system of the stone, the products' filming capacity, the penetration depth of the products into the stone, their distribution on the porous system, and their conservation degree through time. Scanning electron microscopy has to be considered as complementary to some other tests and techniques to assess the efficiency of conservation treatments, such as stone‐water contact angle, water vapour permeability, and global colour variations, among others. The conclusion reached is that the SEM technique defines some of the parameters, properties, and characteristics that highly control the efficiency of the treatments. This work confirms the SEM technique, particularly using backscattering electrons, as a very useful and complementary tool to assess the efficiency of the conservation treatments applied to stone materials for restoration purposes.
Research on double‐probe, double‐ and triple‐tip effects during atomic force microscopy scanning
Authors: Chen Yong , Cai Jiye , Liu Meili , Zeng Gucheng , Feng Qian , Chen Zhengwei 
Published: June 2010

AbstractInformation obtained by atomic force microscopy (AFM) depends strongly on the kind of probe or tip used; therefore, probe and tip effects have to be taken into account when verifying or interpreting the data acquired. In many papers, double‐tip effects have been mentioned while other research was done; however, there are only a few special reports on double‐ or triple‐tip effects, especially double‐probe effects. In our paper, metaphase chromosomes of Chinese hamster ovary (CHO) cells, aggregates of pectin molecules, membrane surface of mouse embryonic stem cells, and R‐phycoerythrin‐conjugated immunoglobulin G complexes were imaged by AFM with high‐quality probes, double‐probe cantilever, and doubletip and triple‐tip probes, respectively, in order to determine double‐probe, double‐tip, and triple‐tip effects during AFM scanning. We found that the double‐probe, double‐tip, and triple‐tip effects share the same principle, and that these effects correlate with distance and height differences between probes of double‐probe cantilever or tips of double‐tip or multiple‐tip probes. Since many other factors influence double‐probe or double‐tip effects, more in‐depth studies must be undertaken. However, this initial research will make all users of AFM techniques aware of double‐probe and double‐tip or triple‐tip effects during AFM scanning and aid in verifying or interpreting the data acquired.
Charging in scanning electron microscopy “from inside and outside”
Authors: Cazaux Jacques 
Published: June 2010

AbstractThis paper is an attempt to analyse most of the complicated mechanisms involved in charging and discharging of insulators investigated by scanning electron microscopy (SEM). Fundamental concepts on the secondary electron emission (SEE) yield from insulators combined with electrostatics arguments permit to reconsider, first, the widespread opinion following which charging is minimized when the incident beam energy E0 is chosen to be equal to the critical energy E°2, where the nominal total yield δ°+η°=1. For bare insulators submitted to a defocused irradiation, it is suggested here that the critical energy under permanent irradiation EC2 corresponds to a range of primary electrons, R, and nearly equals the maximum escape depth of the secondary electrons, r. This suggestion is supported by a comparison between published data of the SEE yield δ° of insulators (short pulse experiments) and experimental results obtained from a permanent irradiation for EC2. New SEE effects are also predicted at the early beginning of irradiation when finely focused probes are used. Practical considerations are also developed, with specific attention given to the role of a contamination layer where a negative charging may occur at any beam energy. The role of the various time constants involved in charging and discharging is also investigated, with special attention given to the dielectric time constant, which explains the dose rate‐dependent effects on the effective landing energy in the steady state. Numerical applications permit to give orders of magnitude of various effects, and several other practical consequences are deduced and illustrated. Some new mechanisms for the contrast reversal during irradiation or with the change of the primary electron (PE) energy are also suggested.
Atomic force microscopy imaging of retroviruses: Human immunodeficiency virus and murine leukemia virus
Authors: Kuznetsov Yu. G. , Low A. , Fan H. , McPherson A. , Victoria J. G. , Robinson W. E. 
Published: June 2010

AbstractRetroviruses are membrane‐enveloped, RNA‐containing viruses that produce a wide range of threatening diseases in higher animals. Among these are human immunodeficiency virus (HIV), which produces acquired immune deficiency syndrome (AIDS) in humans, and murine leukemia virus (MuLV), which produces leukemias in rodents. We have obtained the first atomic force microscopy (AFM) images of these two retroviruses, both isolated from culture media and emerging from infected cell surfaces. The HIV virions are 127 nm diameter on average, and those of MuLV are 145 nm, although there are wide distributions about the means. The AFM images show the arrangement of the envelope protein, responsible for host cell entry, on the surfaces of both virions. Disruption of the viruses using detergents or physical means allowed us to visualize interior structures, including the outer shells of both MuLVand HIV, the cores of MuLV, and the nucleic acid of HIV complexed with core proteins. Using immunolabeling techniques borrowed from electron microscopy, we were able to demonstrate the binding of gold‐labeled antibodies directed against the envelope protein of MuLV. The AFM images are revealing, not only in terms of surface topology, but in terms of interior features as well, and they reveal the eccentricities and uniqueness of individual virus particles rather than yielding the average member of the population. Further application of AFM to viruses associated with other pathologies may ultimately have a significant impact on the diagnosis and treatment of virus‐promoted diseases.
Mechanical scanning of the specimen in the scanning electron microscope
Authors: Oho Eisaku , Miyamoto Makoto 
Published: June 2010

AbstractA scanning electron microscope (SEM) system equipped with a motor drive specimen stage fully controlled with a personal computer (PC) has been utilized for obtaining ultralow magnification SEM images. This modern motor drive stage works as a mechanical scanning device. To produce ultra‐low magnification SEM images, we use a successful combination of the mechanical scanning, electronic scanning, and digital image processing techniques. This new method is extremely labor and time saving for ultra‐low magnification and wide‐area observation. The option of ultra‐low magnification observation (while maintaining the original SEM functions and performance) is important during a scanning electron microscopy session.