Triacetin as Lubricant Additive: Slipping Friction between Metal Pairs under Boundary Lubrication

Friction between rubbing pairs plays a key role in operating machines in an efficient approach. In some intended works or occasional circumstances, slipping friction may occur during dry or boundary lubrication. Lubricating mechanical equipment using proper and efficient lubricant agents is tremendously necessary. This work explores the synthesized triacetin as an additive for lubricant under slipping friction between steel rollers and aluminum, brass, copper, and stainless-steel rods under boundary lubrication. The metal surface morphology under the lubricant with 10% triacetin additive covering roughness periphery is investigated by Field Emission Scanning Electron Microscope imaging. In the dry slipping condition, the friction coefficient is lower for the copper-steel pair compared to the aluminum-steel combination. Compared to the absence of triacetin additive, the steel roller combinations with the rod metal specimens undergoing boundary lubrication with 10% triacetin additive in the lubricant can reduce the slipping friction coefficient by up to 49.2% in the case of steel roller and brass rod pair. The quantitative influences of triacetin additive on metal rubbing pair friction coefficients under boundary lubrication are inversely exponential correlated to triacetin additive, varying in the range of 0 to 10% v/v.

A Study of Fabricating Nano-W Colloid by Discharge Energy Enhancement of the micro-EDM System

This study enhanced the discharge energy of an existing micro-electric discharge machining (EDM) system to provide the system with the ability to prepare nano-tungsten (nano-W) colloid. The energy- enhanced EDM system, referred to as the upgraded-micro-EDM system, enables spark discharge using tungsten wires immersed in deionized water to produce nano-W colloids. Compared with the chemical preparation method, the processing environment for preparing colloids will not have nanoparticle escape in this study. Among the nano-W colloids prepared using the upgraded-micro-EDM system and an industrial EDM system, the colloid prepared by the upgraded-micro-EDM system exhibited more favorable absorbance, suspensibility, and particle size. The colloid prepared by the upgraded-micro-EDM system with the pulse on time and off time of 10–10 µs had an absorbance of 0.277 at the wavelength of 315 nm, ζ potential of −64.9 mV, and an average particle size of 164.9 nm. Transmission electron microscope imaging revealed the minimum particle size of approximately 11 nm, and the X-ray diffractometer spectrum verified that the colloid contained only \({\text{W}}_{2.00}\) and W nanoparticles. Relative to industrial EDM applications for nano-W colloid preparation, the upgraded system boasts lower costs and smaller size, and produces nano-W colloid with superior performance. These advantages contribute to the competitiveness of electrical spark discharge method in the preparation of high-quality nano-W colloids.

Propaedeutic Study of Biocomposites Obtained With Natural Fibers for Oceanographic Observing Platforms

In response to the pervasive anthropogenic pollution of the ocean, this manuscript suggests the use of biodegradable elastomers in marine applications. The present study characterizes 25 samples of highly biodegradable polymers, obtained blending a base elastomer with natural fibers. Mechanical analysis and Scanning Electron Microscope imaging, reveal how base polymers behave differently depending on the plant fiber chosen, on the external forcing—exposure to water—and on the doses that constitute the final biocomposite. Results suggest that EcoflexTM 00-30 and EcoflexTM 00-50, mixed with potato starch, perform best mechanically, maintaining up to 70% of their maximum tensile strain. Moreover, early signs of degradation are visible on polysiloxane rubber blended with 50% vegetable fibers after 19 hours in distilled water. Analyses demonstrate that highly biodegradable elastomers are good candidates to satisfy the requirements of aquatic devices. Furthermore, the discussed materials can improve the dexterity and biodegradability of marine technology.

Artificial Intelligence to Detect Meibomian Gland Dysfunction From in-vivo Laser Confocal Microscopy

Background: In recent years, deep learning has been widely used in a variety of ophthalmic diseases. As a common ophthalmic disease, meibomian gland dysfunction (MGD) has a unique phenotype in in-vivo laser confocal microscope imaging (VLCMI). The purpose of our study was to investigate a deep learning algorithm to differentiate and classify obstructive MGD (OMGD), atrophic MGD (AMGD) and normal groups.Methods: In this study, a multi-layer deep convolution neural network (CNN) was trained using VLCMI from OMGD, AMGD and healthy subjects as verified by medical experts. The automatic differential diagnosis of OMGD, AMGD and healthy people was tested by comparing its image-based identification of each group with the medical expert diagnosis. The CNN was trained and validated with 4,985 and 1,663 VLCMI images, respectively. By using established enhancement techniques, 1,663 untrained VLCMI images were tested.Results: In this study, we included 2,766 healthy control VLCMIs, 2,744 from OMGD and 2,801 from AMGD. Of the three models, differential diagnostic accuracy of the DenseNet169 CNN was highest at over 97%. The sensitivity and specificity of the DenseNet169 model for OMGD were 88.8 and 95.4%, respectively; and for AMGD 89.4 and 98.4%, respectively.Conclusion: This study described a deep learning algorithm to automatically check and classify VLCMI images of MGD. By optimizing the algorithm, the classifier model displayed excellent accuracy. With further development, this model may become an effective tool for the differential diagnosis of MGD.

Revision of Ischnopelta Stål, 1868 with the description of twenty new species (Hemiptera: Pentatomidae: Discocephalinae)

Ischnopelta Stål, 1868 is a Discocephalini genus with three known species, I. scutellata (Signoret, 1851), I. oblonga (Fieber, 1851), and I. luteicornis (Walker, 1867), and distribution restricted to South America. The examination of 284 specimens from several localities in Venezuela, Brazil, Bolivia, Argentina, and Paraguay, revealed the existence of new species. Measurements of 24 morphometric parameters were taken using stereomicroscope and tpsDig2 version 2.16 from images captured with an MShot MD50 camera coupled to a Techno RZ stereomicroscope and edited in MShot DIS version 1.1. The genitalia of both sexes was dissected upon specimen availability, digested in KOH 10%, dehydrated in ethanol 70%, stained in Congo red (when needed), and preserved in liquid glycerin. Photographs were made in a Nikon AZ100M stereomicroscope, and a focus stacking procedure was done with Nikon NIS-Elements Ar Microscope Imaging Software. Drawings were produced over the images with a vectorial image processor. In this work Ischnopelta is revised, I. scutellata and I. luteicornis are redescribed, and keys to males and females of the species are proposed. We describe 20 new species: I. alalonga sp. n., I. anangulata sp. n., I. bechyneorum sp. n., I. confusa sp. n., I. coralinae sp. n., I. cordiformis sp. n., I. crassula sp. n., I. cristulata sp. n., I. cylindrata sp. n., I. guarani sp. n., I. impunctata sp. n., I. magna sp. n., I. marginella sp. n., I. montana sp. n., I. paiagua sp. n., I. parvula sp. n., I. pellucidula sp. n., I. ruckesi sp. n., I. vellozia sp. n., and I. wigodzinskyi sp. n.. We were unable to locate the syntypes of I. oblonga (Fieber, 1851) and the species is treated here as incertae sedis.

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.

Automated Metrology on the Verticality of Cross-Sectioned Channel Hole at V-NAND with Over 200 Layers by Transmission Electron Microscope

In this paper, we present a nanoscale verticality measurement method for V-NAND with 200 or more layers of high layers using an automated transmission electron microscope, which has been developed a lot in the analysis field. Nanoscale measurements in cross-sectional images in 3D-NAND with such a high layer do not include both the top and bottom areas in one image of FOV. Therefore, it is very difficult for a person to objectively measure the etching angle or verticality of the channel hole. We experimented the verticality measurement of a channel hole in the two images in different areas using an automated transmission electron microscope imaging and measurement. In this paper, we present the results and analysis of the experiment and detailed metrology methods.

Development of Chitosan/Squid Skin Gelatin Hydrolysate Films: Structural, Physical, Antioxidant, and Antifungal Properties

Chitosan (85% deacetylated, viscosity > 400 MPa, and molecular weight of 570.3 kDa)/squid gelatin hydrolysates (SGH) were prepared by incorporating SGHs (10%, 20%, and 40%) into chitosan films. SGH were obtained from squid skin gelatin by hydrolysis with Alcalase. The effects of adding SGH on the physical, chemical structure, mechanical, degradability, antioxidant, and antifungal properties of the chitosan films were evaluated. Films containing SGH were opaquer and more colored than the reference. Scanning electron microscope imaging showed that the surface sections of the CH/SGH films were smooth and homogeneous, though a small amount of insoluble microparticles was observed. Atomic force microscopy indicated that the surface roughness of the chitosan films increased with the addition of SGH. Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy suggested an excellent compatibility of the components due to hydrogen bonding. The flexibility and in vitro degradability of the films increased as the SGH content increased. The 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate acid and 1,1-diphenyl-2-picrylhydrazyl scavenging rate of films increased with the addition of SGH. Moreover, films containing 20% SGH improved the fungistatic activity against Aspergillus parasiticus of chitosan films. The chitosan/SGH composite films have the potential for use in food packaging.