bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Extremophyles in Solar Salt Production
Authors: Davis J S 
Published: July 2020

Abstract
One-third of the worldwide sodium chloride (salt) production (about 200 million tons per year) is manufactured in solar saltworks. A solar saltworks is a series of one or more interconnected, shallow concentrating ponds (40 to 70 cm deep) through which seawater flows, evaporates by wind and sun, and deposits sodium chloride on the floors of crystallizer ponds (30 cm to 50 cm deep). In the downstream flow, salts of low solubility (in respect to sodium chloride) precipitate, with calcium carbonate first dropping out near three times, and calcium sulfate (gypsum) first appearing near four times seawater salinity. Shortly before reaching saturation with sodium chloride (about S.G. 1.214), the brine flows into crystallizer ponds (crystallizers), where evaporation continues until 5 to 20 cm of sodium chloride is deposited on the floors. The supernatant liquid, rich in compounds of calcium, magnesium, chloride, and sulfate, is removed, and the salt is harvested, washed, stockpiled for a time to decrease contaminants, and marketed.
A SEM Study of Epilithic and Endolithic Algae and Cyanophytes in Coquina Beach Rock of North Central Florida
Authors: Love N C , Kelley K L , Davis J S 
Published: July 2020

Abstract
The eastern coast of north central Florida is home to a habitat unique in the southeastern United States. Some areas of the north to north-central Florida beaches consist of outcroppings of coquina, a beach rock formed by shell fragments and sand held together by a calcareous cement. The major constituents of coquina are shell fragments of the surf clam Donax variabilis, while fragments of Area sp. and Dinocardium sp. are also generally present. These same shell fragments are also found loose comprising most of the beach “sand” in this area. The coquina serves as a substrate for a variety of attatched seaweeds and fouling organisms. Microalgae and cyanophytes of interest to this study can be classified as either epilithic or endolithic. Epilithic microorganisms inhabit the surface, using the rock primarily as a site of attatchment. The endolithic microorganisms are those algae and cyanophytes that actively bore into the coquina rock's shell fragments.
Impact of Cryo Techniques on Cytological Studies of Plant Pathogenic Fungi and their Hosts
Authors: Howard R J , Bourett T M , Duncan K E 
Published: July 2020

Abstract
Cryo techniques of specimen preparation have become the standard for cytological studies of biological specimens. From the pioneering work of Feder and Sidman, and Zalokar, the now ubiquitous application of freeze substitution for transmission electron microscope studies of fungi was a direct result of work reported in 1979. Since then, cryopreparative methods have also become the standard for SEM studies and may, for certain purposes, replace conventional methods of fixation for light microscopy as well. Undoubtedly, there are instances where non-cryo methods might be preferred, or where comparisons of results using cryo vs. chemical fixations can provide unique information. On the whole, however, the advantages offered to mycologists and plant pathologists by cryo fixation over any chemical methods are many, and include (a) the opportunity to preserve specimens in a non-aqueous environment, (b) preservation of labile structures such as certain organelles, extracellular matrices, or various cellular content such as ions or that of vacuoles, (c) preservation of cells in a more life-like state,
Ultrastructure of Conidia of the Plant Pathogenic Fungus Entomosporium Mespili
Authors: Richardson Elizabeth A , Mims Charles W 
Published: July 2020

Abstract
Entomosporium mespili has emerged as a significant pathogen of red tip (Photinia × fraseri), a popular and widely grown ornamental in the southeastern United States. This fungal pathogen produces its distinctive multi-celled, insect-like asexual spores or conidia (Fig. 1) in structures known as acervuli (Fig. 2) that rupture the surfaces of infected leaves. This study examines the fine structure of these conidia using a combination of scanning and transmission electron microscopy. In the case of transmission electron microscopy, conidia were prepared for study using either plunge freezing or high pressure freezing followed by freeze substitution.
Each mature conidium of E. mespili consists of four to six cells (Fig. 1). These include one apical cell and one basal cell and two to four small lateral cells attached to the basal cell. The apical and lateral cells each possess a long, slender appendage. Excluding these appendages, the length of a mature conidium is usually 20-24μm while the diameters of the apical and basal cells are 8-11μm and 6-9μm respectively.
Ultrastructure of the Infection of Poinsettia by Oidium SP. using High Pressure Freezing and Freeze Substitution
Authors: Celio G J , Richardson E A , Mims C W 
Published: July 2020

Abstract
Cryofixation is becoming more widely used to study host-pathogen relationships in fungal diseases of plants. This presentation describes results we have obtained using high pressure freezing and freeze substitution to study powdery mildew disease of poinsettia ﹛Euphorbia pulcherrima) caused by Oidium sp.
Approximately 0.5 mm leaf disks bearing sporulating colonies of Oidium sp. were excised and placed in a 15% dextran solution contained in brass planchets. Samples were frozen using a Balzer's HPM 010 High Pressure Freezing Machine and substituted according to the procedures of Hoch.6 Thin sections of embedded leaves were cut using a diamond knife, collected on gold slot grids, and placed on formvar-coated racks. Sections were poststained with uranyl acetate and lead citrate and examined using a Zeiss EM 902A transmission electron microscope.
Outstanding preservation of haustoria, the specialized nutrient-absorbing structures produced in host epidermal cells by Oidium, was obtained. Both young, unlobed (Fig. 1) as well as mature, highly lobed (Fig. 2) haustoria were observed.
Semiconductor Defect Studies Using Scanning Probes
Authors: Hsu Julia W P 
Published: July 2020

Abstract
Understanding how defects alter physical properties of materials has lead to improvements in materials growth as well as device performance. Transmission electron microscopy (TEM) provides an invaluable tool for structural characterization of defects. Our current knowledge of crystallographic defects, such as dislocations, would not have been possible without TEM. Recently, scanning tunneling microscopy and scanning force microscopy (SFM) have shown the capability of imaging surface defects with atomic or near-atomic resolution in topographic images. What is more important is to gain knowledge on how the presence of a certain type of defects changes the physical properties of materials. For example, how is the carrier lifetime altered near electrically active defects? How does photoresponse vary near grain boundaries? Where are defect levels in the forbidden bandgap? This talk will discuss several examples of how scanning probe microscopies (SPMs) can contribute to this aspect of defect studies in semiconductors.
Polarization Screening and Image Formation in SSPM, EFM and Piezoresponse Imaging of Ferroelectric BaTiO3 (100) Surface
Authors: Kalinin Sergei V , Bonnell Dawn A 
Published: July 2020

Abstract
Possible applications of ferroelectric materials in non-volatile memories, MEMS, microwave ceramics, PTCR devices and sensors draw significant interest to these materials. Operation of most of these devices relies heavily on the surface (FRAM and other thin-film devices) and interface (PTCR, varistors) properties of ferroeiectrics, particularly on the polarization and charge distribution in the surface or interface region. Electrostatic scanning probe techniques such as electrostatic force microscopy (EFM), scanning surface potential microscopy (SSPM) and piezoresponse imaging (PRI) can be successfully employed for the characterization of ferroelectric surfaces on the micron and submicron level. The former technique is based on the detection of the resonant frequency shift of mechanically driven cantilever, which is proportional to gradient of electrostatic force acting on the tip. The latter two techniques are based on the voltage modulation approach, i.e. during imaging the piezoelectric actuator driving the cantilever is disengaged and the AC bias is applied directly to conductive tip.
Quantitative Study Of MgO (110) Surface Faceting Angles by AFM and SEM
Authors: Giese D R , Lamelas F J , Owen H A , Gajdardziska-Josifovska M 
Published: July 2020

Abstract
The stability of polar and neutral MgO surfaces has been addressed by theory and experiment as an ideal example of ionic oxides with rock-salt structure, but with unresolved controversial results. For example, energy-minimization theory predicted that higher energy polar MgO (111) and neutral MgO (110) surfaces could thermally facet into the lowest energy MgO (100) planes. Early low-energy electron diffraction (LEED) experiments reported diffraction spot splitting, interpreted as evidence for thermal faceting to ﹛100﹜ planes. However, a recent study found MgO (111) faceting was caused by chemical etching with nitric or phosphoric acid, and not promoted by annealing. Quantitative atomic force microscopy (AFM) and scanning electron microscopy (SEM) measurement of the facet angles revealed them to be vicinal planes rather than the predicted ﹛100﹜ planes. A recent AFM study reported thermal faceting of MgO (110) into vicinal planes.
Imaging Ultrathin Organic Films on the Nanometer Level Using Surface Plasmons
Authors: Bailey GW , McKernan S , Price RL , Walck SD , Charest P-M , Gauvin R , Fried G , Bohn W 
Published: July 2020

Abstract
Surface plasmons have been used to detect single molecular layers for many years. The most common examples are biosensor systems and the detection of self-assembled monolayers (SAMs). A surface plasmon is a two-dimensional electromagnetic wave that travels on the surface of a noble metal, most commonly gold or silver. This electromagnetic wave is extremely sensitive to changes in the dielectric constant 100 nm above the metal surface. When the dielectric constant above the metal changes due to the addition of a molecular layer, the intensity of the surface plasmon will decrease. In this way monolayers may be indirectly imaged on a surface by mapping the surface plasmon intensity.
Although there are many reasons for imaging ultrathin films or molecular layers over large distances (10-100 μm), there are several difficulties involved. Typically the substrate has a roughness greater than the height of a single monolayer. This can mask the presence of the monolayer on large area scans.
Determining Grain Boundary Potential from Electrostatic Force Based Scanning Probe Imaging
Authors: Bonnell Dawn A , Kalinin Sergei V 
Published: July 2020

Abstract
A combination of electrostatic force microscopy (EFM) and scanning surface potential microscopy (SSPM) is used to quantify nanometer scale field variations for the general case of electronically inhomogeneous surfaces. The specific example illustrated here is the intersection of a Σ5 grain boundary in donor doped SrTiO3 intersecting the (100) surface. ‘The topographic structure is compared to the surface potential, the positive and the negative electrostatic force images in figure 1. The EFM contrast changes sign with the polarity of the applied bias, as expected for an electrostatic attractive/repulsive interaction. There is a significant localization of surface potential at the grain boundary that is manifest as a protrusion in the SPPM image.
To quantify the properties at the surface, rather than above the surface where the measurements are acquired, a relationship connecting the sample-tip interaction is required. It has been shown that models based on simple geometric assumptions do not represent the behavior well.
Direct Electron Exposed Silicon Detectors in EELS
Authors: Orsholm Claes , Csillag Stefan 
Published: July 2020

Abstract
Samples to be studied using EELS techniques are more or less sensitive to the effects of the radiation exposed to them by the beam. Quite often the sample is damaged due to the high radiation doses in the areas where the beam has been focused. Secondly, the build up of carbon contamination on the surface of the sample caused by the beam affects the results of the analysis if the sample itself contains carbon. The solution to these problems is to minimize the exposure times needed to record the spectrum, which will lower the radiation-doses on the sample. In addition, problems related to beam instabilities would be reduced due to the shortened acquisition times. However, in order still to achieve an acceptable signal-to-noise ratio the need for a detector with high detective quantum efficiency is essential. We have investigated the possibilities using silicon detectors such as photodiode arrays (PDA) and charge coupled devices (CCD) in direct electron detection mode using 100 keV incident electrons.
New Multifunctional Detector Unit for SEM
Authors: Dolukhanyan T , Galstyan V , Nielsen C , Sung C 
Published: July 2020

Abstract
In order to increase analytical capabilities of SEM we have developed a multifunctional detector unit, which allows the simultaneous and highly efficient registration of the information from the chosen area of the specimen using backscattered electrons (BSE) and cathodoluminescent (CL) radiation. At the same time secondary electrons (SE) could be collected by the regular Everhart - Thornley detector. Thus, the unit allows to perform microstructural investigations in three modes of SEM operation simultaneously - BSE, CL and SE. A schematic diagram of the unit is presented in Fig. 1.
In the plate made of scintillating material, and installed between the pole piece of SEM and the specimen, the bottom side is a part of spherical surface. The surface covers completely the whole top surface of the specimen and collects BSE and CL radiation in the solid angle ∼2 π sr.
Electrostatic Aberration Correction in LV-SEM
Authors: Maas DJ , Henstra A , Krijn MPCM , Mentink SAM 
Published: July 2020

Abstract
The resolution of a low-voltage electron microscope is limited by the chromatic and spherical aberration of the objective lens, see Fig. 1. The design of state-of-the-art objective lenses is optimised for minimal aberrations. Any significant improvement of the resolution requires an aberration corrector. Recently, correction of both Cc and Cs has been demonstrated in SEM, using a combination of magnetic and electrostatic quadrupoles and octupoles (Zach and Haider, 1995). The present paper presents an alternative design, which is based on a purely electrostatic concept, potentially simplifying the ease-of-use of an aberration corrected microscope.
In 1936 Scherzer showed that the fundamental lens aberrations of round lenses are positive definite, in absence of time-varying fields and/or space charge. Negative lens aberrations, required for the correction of Cc and Cs, can only be obtained using non-round lenses, e.g. quadrupoles and octupoles (Scherzer, 1947).
The Energy Spectra of Secondary Electrons
Authors: Joy David C , Braski David 
Published: July 2020

Abstract
It has been estimated that more than 90% of all scanning electron microscope (SEM) images ever published have been obtained using secondary electrons (SE) which are defined as being those electrons emitted with energies between 0 and 50eV. The properties of these secondary electron are therefore of considerable interest and importance. However, although secondary electrons have been intensively studied since their discovery by Starke in 1901 the majority of the work has been aimed at determining the SE yield coefficient and its variation with energy for elements and compounds. The energy spectrum of secondary electrons has received far less attention although it is evident that the form of the spectrum must have an effect on the image contrast observed in the SEM because SE detectors are energy selective devices. The few studies that have been made have mostly concentrated on spectra obtained from clean samples observed under ultra-high vacuum conditions. This is understandable, because it is certain that the presence of a surface layer of contamination will change the SE spectrum to some degree or other, but it is unfortunate because all specimens in real SEMs are dirty and it is information about this situation that is required.
Imaging of Insulators in LVSEM and Related Physical Mechanisms
Authors: Cazaux Jacques 
Published: July 2020

Abstract
From the best fit of two adjustable parameters, B (escape probability) and ƛ (empirical escape depth of the secondary electrons, s.e.), the constant loss theory accounts fairly well for the s. e. emission from materials: δ (E0) = B [E0/E(e.h)] [ƛ/R] [1 - exp. -(R/ ƛ)] (1) (with E(e.h): energy required for generating a s.e. inside the specimen; R: range of the incident electron related to the primary beam energy, E0, via a power law of the form: R=C E0n). The influence of the angle of incidence, i, may also be estimated by changing R into R cos i (see fig la for the example of diamond with B/ E(e.h) = 22 keV-1; ƛ ≈ 10 nm). For insulators, δ is obtained from short pulse experiments (to prevent charging) and, in the 1-5 keV range, it is often one order of magnitude (or more) larger than that of metals via a larger ƛ value (also more sensitive to the temperature, to the crystalline state and resulting from a random walk involving many elastic and inelastic-phonon- scattering events).
Imaging and Microanalysis of Non-Conducting Materials in the Lowvoltage FE-SEM: Challenges and Strategies
Authors: Liu Jingyue 
Published: July 2020

Abstract
Under high-energy electron bombardment, electrical charge can rapidly build up in non-conducting materials. The electron-induced charging process is very complex and is still not well understood. Injection of energetic electrons into insulators generates electron-hole pairs which can be localized at pre-existing or newly created charge-trap centers. Charging of insulators results from a balance between the emission of secondary electrons and the diffusion and trapping of incident electrons. In the SEM, charging is usually a dynamic process: the degree of specimen charging depends on the energy and the dose of the incident electrons, the image magnification, the pixel dwell time (PDT), and the history of the electron irradiation of the specimen. Although the degree of charging can be reduced by varying the energy of the incident electrons, charging of non-conducting specimens cannot be completely eliminated due to variations in the local SE yield across the specimen surface and the presence of charge-traps inside the specimen.
Applications of High Resolution Microcalorimeter Type X-Ray Spectrometers in Material Analysis
Authors: Höhne Jens , Bühler Matthias , Hertrich Theo , Hess Uwe 
Published: July 2020

Abstract
As the semiconductor industry further shrinks feature sizes, new analytical solutions are required for elemental composition analysis. Conventional EDX analysis is limited by the obtainable energy resolution. In order to analyze extremely small impurity particles, material doping, interdiffusion effects or small chip structures, the diameter of the area hit by an electron beam and particularly the volume of electron-surface interaction has to be reduced accordingly. This can be achieved by reducing the electron beam energy.
X-ray spectroscopy is most frequently used for damage free material testing. Nowadays, semiconductor based energy dispersive X-ray spectrometers (EDS) are employed on a routine basis and are frequently used in combination with scanning electron microscopes (SEMs). But performance is limited by their rather poor energy resolution, which is typically in the 130eV range for a 6keV X-ray line, and their limited capability of resolving X-ray lines within short spectral ranges. Further, overlaps of spectral lines are most critical in the low energy range.
Low Voltage Topographic Imaging of Biological Samples in the SEM
Authors: Walther Paul 
Published: July 2020

Abstract
Joy and Pawley (1992) defined the limitations of spatial resolution in the SEM as follows. “The spatial resolution of the scanning electron microscope is limited by at least three factors: the diameter of the electron probe, the size and shape of the beam/specimen interaction volume with the solid for the mode of imaging employed and the Poisson statistics of the detected signal.” The interaction volume of the primary beam in the sample increases with increasing accelerating voltage (Vo), because electrons with higher energy penetrate deeper into the sample. The interaction volume affects the spatial resolution, because the electrons that finally form the image do not only originate from the impact point of the primary beam, but from the much larger interaction volume. It is not simple to understand how this affects spatial resolution, since resolution is also heavily influenced by the properties of the sample surface (the surface coating) and it is the issue of ongoing debates.
Field Emission SEM with a Newly Developed FEGUN and Conical Strongly Excited Objective Lens
Authors: Bailey GW , McKernan S , Price RL , Walck SD , Charest P-M , Gauvin R , Kazumori H , Yamada A , Mita M , Nokuo T , Saito M 
Published: July 2020

Abstract
A newly developed cold FE-GUN which enables to us to obtain large probe current and low emission noise, and conical strongly excited objective lens has been installed on the JSM-6700F Scanning Electron Microscope (SEM). In the range of accelerating voltages from 0.5 to 15kV, this instrument has got much better resolution as compared with in-lens type SEM (Ohyama et al 1986)(Fig. 1). We can obtain high-resolution secondary electron images with large samples (ex. 150mm ϕ×10mmH).
Our old type objective lens (Kazumori et al 1994) has the limitation of working distance (WD), but the new lens enables us to work at very short WD at accelerating voltage of 15kV. As a result the spherical (Cs) and chromatic (Cc) aberration constants are 1.9mm and 1.7mm respectively at a WD of 3mm.
In order to get large probe current, we increased emission current and got near the distance between the t ip of emi tter and the pr inciple plane of condenser lens.
Fractal Characterization of the Fractured Surface of a Duplex Stainless Steel and Their Relation with the Strength and Ductility
Authors: Hilders O A , Sáenz L , Peña N , Ramos M , Quintero A , Caballero R , Berrío L 
Published: July 2020

Abstract
Due to the very good combination of the most outstanding properties of ferrite and austenite, the microstructure of duplex stainless steels allows them to obtain high strength and toughness levels even at low temperatures. As a result of these combined effects, duplex stainless steels have become very popular for many applications. In practice, the prolonged use of these materials at temperatures below approximately 500°C may cause an embrittlement of the ferrite phase, which has been called 475°C embrittlement. Thus, the isothermal aging at 475°C can be exploited to produce a variety of strength values associated with the corresponding decreases in ductility and variations of the fractal dimension of the fracture surfaces. No experimental measurements of the fractal dimension - tensile properties relationships are available for many commercial metallic alloys, then, the present experiments on a duplex stainless steel were conducted to show that the fractal dimension, D, many be used as a characterization parameter in fracture morphology - mechanical properties studies.