Development of an Innovative Inspection Tool for Superheater Tubes in Fossil Fuel Power Plants

Fossil fuel power plants are complex systems containing multiple components that require periodic health monitoring. Failures in these systems can lead to increased downtime for the plant, reduction of power, and significant cost for repairs. Inspections of the plant’s superheater tubes are typically manual, laborious, and extremely time-consuming. This is due to their small diameter size (between 1.3 and 7.6 cm) and the coiled structure of the tubing. In addition, the tubes are often stacked close to each other, limiting access for external inspection. This paper presents the development and testing of an electrically powered pipe crawler that can navigate inside 5 cm diameter tubes and provide an assessment of their health. The crawler utilizes peristaltic motion within the tubes via interconnected modules for gripping and extending. The modular nature of the system allows it to traverse through straight sections and multiple 90° and 180° bends. Additional modules in the system include an ultrasonic sensor for tube thickness measurements, as well as environmental sensors, a light detecting and ranging (LiDAR) sensor, and camera. These modules utilize a gear system that allows for 360° rotation and provides a means to inspect the entire internal circumference of the tubes.

Recovery of Gelatin from Bovine Skin with the Aid of Pepsin and Its Effects on the Characteristics of the Extracted Gelatin

Pepsin enzyme was used to pretreat the bovine skin at the rate of 5, 15, and 25 units of enzyme/g of skin to recover gelatin, and the recovered gelatins were referred to as Pe5, Pe15, and Pe25, respectively. The gelatin yield increased significantly (p < 0.05) from 18.17% for Pe5 to 24.67% for Pe25 as the level of pepsin increased, but the corresponding gel strength and viscosity decreased significantly (p < 0.05) from 215.49 to 56.06 g and 9.17 to 8.17 mPa.s for Pe5 and Pe25, respectively. β- and α1- and α2-chains were degraded entirely in all the gelatins samples as observed in protein pattern elaborated by gel electrophoresis. 1H nuclear magnetic resonance (1H NMR) analysis indicated the coiled structure of gelatin protein chains. The lowest amide III amplitude of Pe25 as found by Fourier transform infrared (FTIR) spectroscopy indicated that α-helix structure of protein chains were lost to more irregular coiled structure. Thus, it could be summarized that pepsin might be used at the lower level (5 units/g of wet skin) to extract gelatin from bovine skin with good functional properties and at higher level (15/25 units/g of wet skin) to obtain gelatin of industrial grade with high yield.

Self-Reinforced Nylon 6 Composite for Smart Vibration Damping

Passive vibration control using polymer composites has been extensively investigated by the engineering community. In this paper, a new kind of vibration dampening polymer composite was developed where oriented nylon 6 fibres were used as the reinforcement, and 3D printed unoriented nylon 6 was used as the matrix material. The shape of the reinforcing fibres was modified to a coiled structure which transformed the fibres into a smart thermoresponsive actuator. This novel self-reinforced composite was of high mechanical robustness and its efficacy was demonstrated as an active dampening system for oscillatory vibration of a heated vibrating system. The blocking force generated within the reinforcing coiled actuator was responsible for dissipating vibration energy and increase the magnitude of the damping factor compared to samples made of non-reinforced nylon 6. Further study shows that the appropriate annealing of coiled actuators provides an enhanced dampening capability to the composite structure. The extent of crystallinity of the reinforcing actuators is found to directly influence the vibration dampening capacity.

A Nature’s Curiosity: The Argonaut “Shell” and Its Organic Content

Molluscs are known for their ability to produce a calcified shell resulting from a genetically controlled and matrix-mediated process, performed extracellularly. The occluded organic matrix consists of a complex mixture of proteins, glycoproteins and polysaccharides that are in most cases secreted by the mantle epithelium. To our knowledge, the model studied here—the argonaut, also called paper nautilus—represents the single mollusc example where this general scheme is not valid: the shell of this cephalopod is indeed formed by its first dorsal arms pair and it functions as an eggcase, secreted by females only; furthermore, this coiled structure is fully calcitic and the organization of its layered microstructures is unique. Thus, the argonautid shell appears as an apomorphy of this restricted family, not homologous to other cephalopod shells. In the present study, we investigated the physical and biochemical properties of the shell of Argonauta hians, the winged argonaut. We show that the shell matrix contains unusual proportions of soluble and insoluble components, and that it is mostly proteinaceous, with a low proportion of sugars that appear to be mostly sulfated glycosaminoglycans. Proteomics performed on different shell fractions generated several peptide sequences and identified a number of protein hits, not shared with other molluscan shell matrices. This may suggest the recruitment of unique molecular tools for mineralizing the argonaut’s shell, a finding that has some implications on the evolution of cephalopod shell matrices.

Carboxy-Terminal Cementum Protein 1-Derived Peptide 4 (cemp1-p4) Promotes Mineralization through wnt/β-catenin Signaling in Human Oral Mucosa Stem Cells

Human cementum protein 1 (CEMP1) is known to induce cementoblast and osteoblast differentiation and alkaline phosphatase (ALP) activity in human periodontal ligament-derived cells in vitro and promotes bone regeneration in vivo. CEMP1′s secondary structure analysis shows that it has a random-coiled structure and is considered an Intrinsic Disordered Protein (IDP). CEMP1′s short peptide sequences mimic the biological capabilities of CEMP1. However, the role and mechanisms of CEMP1′s C-terminal-derived synthetic peptide (CEMP1-p4) in the canonical Wnt/β-catenin signaling pathway are yet to be described. Here we report that CEMP1-p4 promotes proliferation and differentiation of Human Oral Mucosa Stem Cells (HOMSCs) by activating the Wnt/β-catenin pathway. CEMP1-p4 stimulation upregulated the expression of β-catenin and glycogen synthase kinase 3 beta (GSK-3B) and activated the transcription factors TCF1/7 and Lymphoid Enhancer binding Factor 1 (LEF1) at the mRNA and protein levels. We found translocation of β-catenin to the nucleus in CEMP1-p4-treated cultures. The peptide also penetrates the cell membrane and aggregates around the cell nucleus. Analysis of CEMP1-p4 secondary structure revealed that it has a random-coiled structure. Its biological activities included the induction to nucleate hydroxyapatite crystals. In CEMP1-p4-treated HOMSCs, ALP activity and calcium deposits increased. Expression of Osterix (OSX), Runt-related transcription factor 2 (RUNX2), Integrin binding sialoproptein (IBSP) and osteocalcin (OCN) were upregulated. Altogether, these data show that CEMP1-p4 plays a direct role in the differentiation of HOMSCs to a “mineralizing-like” phenotype by activating the β-catenin signaling cascade.

Electro-osmotic trapping and compression of single DNA molecules while passing through a nanopore

Complicated DNA molecular behaviors exist during translocation into a nanopore because their large and coiled structure needs to unwind.

The History and Science of Hurricanes in the Greater Caribbean

The Caribbean’s most emblematic weather symbol is the hurricane, a large rotating storm that can bring destructive winds, coastal and inland flooding, and torrential rain. A hurricane begins as a tropical depression, an area of low atmospheric pressure that produces clouds and thunderstorms. Hurricane season in the Caribbean runs from June 1 through November 30, although there have been infrequent storms that formed outside these dates. Hurricanes are classified according to their maximum wind speed, and when a tropical system reaches the wind speed of a tropical storm (35 mph), it is given a name. Lists of names, which are rotated periodically, are specific to certain regions. If a named storm is responsible for causing a significant number of deaths or property damage, the name is retired and replaced with another. Most deaths in a storm came from drowning, from storm surge along the coast or from flooding or mudslides in the interior. Storm-related deaths also occur when structures collapse or when victims are struck by flying debris. One important and underestimated cause of death after the passage of a storm is disease. Even if the destruction is not immediate, the passage of a hurricane can leave significant ecological damage along the coast and in the interior. Hurricanes can have a devastating effect on a community that takes a direct hit. Repeated hurricane strikes can leave a sense of helplessness and hopelessness, “hurricane fatigue.” Conversely, survivors of a disaster are often left with a feeling of confidence that, since they have endured the effects of at least one deadly hurricane, they can do so again. Until the last half of the 18th century, meteorology remained primitive, but the Age of Enlightenment brought scientific and ideological advances. Major beneficiaries were royal navies whose navigation manuals and nautical charts became increasingly more accurate. In 1821, William C. Redfield established the circular nature of storms and their counterclockwise rotation, while other scientists showed how wind currents within the storms moved upward. Once the coiled structure of hurricanes were established by mid-century, the term “cyclone” was applied, based upon the Greek word for the coils of a snake. After the mid-19th century, scientists moved from information gathering to attempts to predict hurricane strikes. Technology, in the form of the telegraph, was a key component in creating a forecasting system aided by organizations such as the Colegio de Belén, in Havana, Cuba. Later in the century, governments worldwide created official observation networks in which weather reports were radiotelegraphed from ships at sea to stations on land. The 20th century experienced advances, such as the use of kites and balloons, and the introduction of weather reconnaissance aircraft during World War II. In April 1960, the first satellite was launched to observe weather patterns, and by the early 1980s, ocean buoys and sophisticated radar systems made forecasts increasingly more accurate.

Electrohydrodynamic Direct Writing Platform Based on Near-Field Electrospinning

Electrohydrodynamic Direct Writing (EDW) based on Near-Field Electrospinning (NFES) is a novel method to fabricate aligned micro/nano structure. In this article, linear motors and PIV&F servo control algorithm are introduced to set up an EDW experiment platform, by which patterned micro/nano structure can be direct-written. The motion track and position of collector is adjusted accurately by the platform, thus the deposition position and pattern of direct-written micro/nano structure can be controlled according to the pre-designed pattern. When motion velocity of collector higher than the ejection jet, micro/nano structure in straight line can be gained; but twisted structure can be direct-written under lower motion velocity of collector. The standstill of collector is introduced to overcome the pattern distortion that stems from the sharp change of collector motion track and the inertia of following jet. With the help of motion standstill, the patterned micro/nano structure without distortion can be direct-written, and more jet would be deposited at the corner of the pattern leaded to coiled structure. The EHD platform builds up the based for the industrial application of 1D micro/nano structure.

High Energy Density, High Operating Frequency and Energy Efficient On-Chip Inductors based on Coiled Carbon Nanotubes (CCNTs)

ABSTRACTWe demonstrate the superior inductive properties of coiled carbon nanotubes (CCNTs) through numerical computation and analytical modeling, for the next generation of nanoscale, on-chip inductors. Taking advantage of the kinetic inductance (Lk), particularly evident at the nanoscale we find that the inductance can be increased by three orders of magnitude through changing the tube radius as well as the coil radius while the device footprint of the CCNTs can be reduced by 60%. By varying the geometric parameters of the coiled structure, the external magnetic inductance (LM,ext) can be as high as 20% of the Lk. We also report that the self resonant frequency (fSR) of CCNTs can be as much of the order of THz whereas the fSR of conventional copper(Cu) spiral inductors are limited to around 40GHz. Moreover when the material volume is considered, CCNTs have the potential to achieve Quality Factor (Q) eight times as Cu and when the footprint volume is considered Q can be twice as Cu All these promising properties of CCNTs make them a potential candidate for the entire frequency spectrum.