Application of TiO2 Nanoparticles in Clay Roofing Tiles as a Photocatalytic Active Material

A novel roofing tile was developed containing various types of nanoparticles of titanium dioxide (TiO2). Experiments were conducted using three types of TiO2 nanoparticles with and without polyethylene glycol (PEG). All types of newly developed nanomaterials were characterized using X-ray diffractometry. Particle size distribution analysis was performed and specific surface area was determined using the Brunauer–Emmet–Teller method. SEM imaging was used for the morphological characterization of nanoparticles. Commercial ceramic roofing tiles underwent a dip-coating procedure to obtain the desired photocatalytic surface. The TiO2 anatase samples exhibited greater surface areas of nanoparticles, thus providing potentially the highest photocatalytic efficiency.

Molecular analysis reveals Latonius planus Kononova to be a derived species of Trissolcus Ashmead

The monotypic genus Latonius Kononova, 1982 (Platygastroidea, Scelionidae), was described from a single female specimen collected in southern Ukraine. It somewhat resembles Trissolcus Ashmead but has a distinctive claval formula. The only species in the genus, Latonius planus Kononova, 1982, is lacking any details regarding biology, sexual dimorphism, intraspecific variability, or distribution. Based on recently collected specimens the present study clarifies the position of Latonius within the Telenominae, provides a comprehensive description accompanied by high quality images, and compares Latonius and Trissolcus. Five molecular markers were amplified, and sequences of L. planus were analyzed using a data set for the molecular phylogeny of Telenominae (Taekul et al. 2014) and a molecular phylogeny of Trissolcus (Talamas et al. 2019). We dissected the metasoma, tarsi, antennae, and ovipositor and performed SEM imaging. The genera Latonius and Ioseppinella Mineo, O’Connor & Ashe, 2010, are treated as junior synonyms of Trissolcus and the type species of Latonius and Ioseppinella are considered to be conspecific (syn. nov.).

Antibacterial and Antibiofilm Activity of Mercaptophenol Functionalized-Gold Nanorods Against a Clinical Isolate of Methicillin-Resistant Staphylococcus Aureus

Gold nanorods (AuNRs) were synthesized and surface functionalized with 4-mercaptophenol (4-MPH) ligand. The surface-functionalized AuNRs, 4-MPH-AuNRs, were characterized by UV-Vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM) imaging, zeta potential, and Fourier-Transformed Infrared (FTIR) spectroscopy. The antibacterial and antibiofilm activities of 4-MPH-AuNRs were evaluated against a clinical isolate of Methicillin-Resistant Staphylococcus aureus (MRSA). The results indicate that the surface-modified nanorods, 4-MPH-AuNRs, exhibit a bactericidal activity with a minimum inhibitory concentration (MIC) of ~6.25 \(\mu\)g/ml against a planktonic suspension of MRSA. Furthermore, 4-MPH-AuNRs resulted in 2-3 log-cycle reduction of MRSA biofilm viable count over a concentration range of 100-4.0 \(\mu\)g/ml. The bacterial uptake of surface-modified nanorods was investigated by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and scanning electron microscopy (SEM) imaging; the results reveal that ~27% of the nanorods were internalized into the bacterial cells after 6 hrs of exposure. SEM imaging revealed a significant accumulation of the nanorods at the bacterial cell wall and a possible cellular internalization. Thus, 4-MPH-AuNRs can be considered a potential novel antibacterial agent, particularly against resistant MRSA strain biofilm.

Proof of Reverse Engineering Barrier: SEM Image Analysis on Covert Gates

IC camouflaging has been proposed as a promising countermeasure against malicious reverse engineering. Camouflaged gates contain multiple functional device structures, but appear as one single layout under microscope imaging, thereby hiding the real circuit functionality from adversaries. The recent covert gate camouflaging design comes with a significantly reduced overhead cost, allowing numerous camouflaged gates in circuits and thus being resilient against various invasive and semi-invasive attacks. Dummy inputs are used in the design, but SEM imaging analysis was only performed on simplified dummy contact structures in prior work. Whether the e-beam during SEM imaging will charge differently on different contacts and further reveal the different structures or not requires extended research. In this study, we fabricated real and dummy contacts in various structures and performed a systematic SEM imaging analysis to investigate the possible charging and the consequent passive voltage contrast on contacts. In addition, machine-learning based pattern recognition was also employed to examine the possibility of differentiating real and dummy contacts. Based on our experimental results, we found that the difference between real and dummy contacts is insignificant in SEM imaging, which effectively prevents adversarial SEM-based reverse engineering. Index Terms—Reverse Engineering, IC Camouflaging, Scanning Electron Microscopy, Machine Learning, Countermeasure.

Selective Dry Etch Removal of Si and SiOxNy for Advanced Electron Beam Probing Applications

This paper presents a global die level sample preparation technique utilizing selective etch chemistry and laser interferometry to expose the entire die top-most metal layer surface for Ebeam electrical FI. A novel Ebeam based probing technique referred to as StaMPS is introduced alongside this prep technique to isolate logic structure failures observed through SEM image contrasts at different logic states. By landing SEM probe tips on exposed metal pads and controlling logic states via an applied bias, the varying states produce different contrast within SEM imaging highlighting structural failure locations. This global prep technique in combination with StaMPS Ebeam FI creates faster FI/FA turn-around time by delivering a globally delayered full die in under an hour and creating opportunity to locate several defect types within a single sample.

EBIRCH Localization for Low-Current Soft Fails

An experimental study was undertaken to determine the minimum level of leakage or shorting current could be detected by EBIRCH. A 22 nm SRAM array was overstressed with a series gradually increasing bias, followed by EBIRCH scans with 1 V applied bias and 2 kV SEM imaging, until fins were observed. The result was that with only 12 nA of shorting current, the fins of a pulldown device could be imaged by EBIRCH. Higher stresses created an ohmic short, and careful consideration of experiments with current direction provide additional evidence that EBIRCH is largely a temperaturedriven, or Seebeck effect.

Analysis of structural differences of Ag Nanoparticles generated using Thermal and E-beam process based on SEM imaging

The variation in applications of nanoparticles (NPs) comes from differences in their microstructures. This may be observed in the terms of variation in size, area fraction and even the morphology of the particles. It is mainly the size and topography of these particles which govern the Mechanical, Optoelectronics, properties and have a huge impact in Bio-medical engineering.

Fiber statistics of nonwoven materials by SEM images - influence of number of images

Electrospun nonwovens are widely applied in biomedicine and various other fields. For control of the manufacturing process and quality assurance Scanning electron microscopy (SEM) imaging is one standard practice. In this study, statistical datasets of 60 SEM images of three nonwoven samples were evaluated using Gaussian fit to obtain numerical results of their fiber diameter distributions. The question of how much effort is required for acceptable imaging and processing is being discussed. As determined here, for reliable statistics, a minimum surface area of the nonwoven has to be evaluated. The fiber diameter should be in a range of approximately 2 - 3% of the edge length of the square equivalent of the evaluated image area, using sufficiently magnified SEM images, in which the fiber diameter is imaged over at least 30 pixels.

Exploration of the Cs Trapping Phenomenon by Combining Graphene Oxide with α-K6P2W18O62 as Nanocomposite

A graphene oxide-based α-K6P2W18O62 (Dawson-type polyoxometalate) nanocomposite was formed by using two types of graphene oxide (GO) samples with different C/O compositions. Herein, based on the interaction of GO, polyoxometalates (POMs), and their nanocomposites with the Cs cation, quantitative data have been provided to explicate the morphology and Cs adsorption character. The morphology of the GO-POM nanocomposites was characterized by using TEM and SEM imaging. These results show that the POM particle successfully interacted above the surface of GO. The imaging also captured many small black spots on the surface of the nanocomposite after Cs adsorption. Furthermore, ICP-AES, the PXRD pattern, IR spectra, and Raman spectra all emphasized that the Cs adsorption occurred. The adsorption occurred by an aggregation process. Furthermore, the difference in the C/O ratio in each GO sample indicated that the ratio has significantly influenced the character of the GO-POM nanocomposite for the Cs adsorption. It was shown that the oxidized zone (sp2/sp3 hybrid carbon) of each nanocomposite sample was enlarged by forming the nanocomposite compared to the corresponding original GO sample. The Cs adsorption performance was also influenced after forming a composite. The present study also exhibited the fact that the sharp and intense diffractions in the PXRD were significantly reduced after the Cs adsorption. The result highlights that the interlayer distance was changed after Cs adsorption in all nanocomposite samples. This has a good correlation with the Raman spectra in which the second-order peaks changed after Cs adsorption.