Techno-economic analysis of conventional and advanced high-pressure tube trailer configurations for compressed hydrogen gas transportation and refueling

Transporting compressed gaseous hydrogen in tube trailers to hydrogen refueling stations (HRSs) is an attractive economic option in early fuel cell electric vehicle (FCEV) markets. This study examines conventional (Type I, steel) and advanced (Type IV, composite) high-pressure tube trailer configurations to identify those that offer maximum payload and lowest cost per unit of deliverable payload under United States Department of Transportation (DOT) size and weight constraints. The study also evaluates the impacts of various tube trailer configurations and payloads on the transportation and refueling cost of hydrogen under various transportation distance and HRS capacity scenarios. Composite tube trailers can transport large hydrogen payloads, up to 1100 kg at 7300 psi (500 bar) working pressure, while steel tube trailer configurations are limited by DOT weight regulations and may transport a maximum hydrogen payload of approximately 270 kg. Using steel pressure vessels to transport hydrogen at high pressure is counterproductive because of the rapid increase in vessel weight with wall thickness. The most economic composite tube trailer configuration includes 30-inch-diameter vessels packed in a 3 × 3 array. A linear relationship between the deliverable payload and the capital cost of a composite tube trailer has been developed for configurations with the lowest cost-per-unit payload. The capital cost is approximately $1100 per kg of deliverable hydrogen payload. Considering the entire delivery pathway (including refueling), tube trailer configurations with smaller vessels packed in greater numbers enable higher payload delivery and lower delivery cost in terms of $/kg H₂, when delivering hydrogen over longer distances to large stations. Selection of the appropriate tube trailer configuration and corresponding hydrogen payload can reduce hydrogen delivery cost by up to 16%.     

Real time asset tracking in the data center

The importance and difficultly of asset tracking make it worthy of attention. We focus on data centers consisting of vertical racks where each rack may accommodate a variety of equipment. We describe an asset tracking system which automatically detects and identifies equipment within rack; has “pinpoint” accuracy, i.e., location resolution equals asset size; relays this information to possibly several management back-ends; includes a back-end application that maintains a location history for all equipment; and uses a visualization tool to display both the current state and the history of deployment. The solution features a flexible architecture that simplifies the connection with both existing and future asset management applications. The architecture supports simple configuration, load balancing, and redundancy. Care has been taken to use widely recognized standards wherever possible. Recommended by Monem Beitelmal     

Upgrading Coal Washery Rejects Through Caustic-acid Leaching

Physical beneficiation of West Bokaro run-of-mine coal gives 15% ash clean coal with 38% yield. Further lowering the ash content in clean coal may cause significant yield loss as well as generation of enormous quantities of middling and reject coals, which are low value material. West Bokaro coal washery of Tata Steel Ltd produces 0.7 million tons of reject coal annually. This work deals with the effect of caustic-acid leaching route for producing 19.7% ash clean coal with more than 40% yield from the rejects with 60% ash. The clean coal obtained in this process can be utilized in thermal power stations and cement industries.     

Estimation of Electronic Suppression Circuit Resistance for Protective Relaying Applications

The transient response of instrument transformers affects the performance of high-speed relays, particularly speed and overreach in case of distance protection. Transient response of a capacitive voltage transformer depends on the type of ferro-resonance suppression circuit (FSC), i.e., active, passive, or electronic, provided in the secondary to damp the ferro-resonant oscillations. The objective of this article is not to estimate optimum resistance but to provide a systematic approach instead of the trial-and-error approach to estimate damping resistance for the electronic ferro-resonance suppression circuit used in the: capacitive voltage transformer for protective relaying application. The performance of the numerical distance relay for the: capacitive voltage transformer with estimated damping resistance in the electronic ferro- resonance suppression circuit is tested and validated in real time using a field programmable gate array.     

CoBi: Pattern Based Co-Regulated Biclustering of Gene Expression Data

Co-regulation is a common phenomenon in gene expression. Finding positively and negatively co-regulated gene clusters from gene expression data is a real need. Existing techniques based on global similarity are unable to detect true up- and down-regulated gene clusters. This paper presents an expression pattern based biclustering technique, CoBi, for grouping both positively and negatively regulated genes from microarray expression data. Regulation pattern and similarity in degree of fluctuation are accounted for while computing similarity between two genes. Unlike traditional biclustering techniques, which use greedy iterative approaches, it uses a BiClust tree that needs single pass over the entire dataset to find a set of biologically relevant biclusters. Biclusters determined from different gene expression datasets by the technique show highly enriched functional categories.     

Synthesis of nanocrystalline iron oxide ultrathin films by thermal decomposition of iron nitropruside: Structural and optical properties

Ultrathin films of nanocrystalline α-Fe₂O₃ have been deposited on glass substrates from an inorganic precursor, iron nitropruside. This is a novel route of synthesis for iron oxide thin films on glass substrates, by annealing the precursor thin film in air at 650 °C for 15 min. The films were characterized using TG-DTA analysis, X-ray diffraction, UV-visible, FESEM, AFM and Raman measurements. X-ray diffraction and Raman analyses revealed that the deposited films contain α-phase of Fe₂O₃ (hematite). The synthetic route described here provides a very simple and cost-effective method to deposit α-Fe₂O₃ thin films on glass substrates with band gap energy of about 2.75 eV. The deposited films were found to show catalytic effect for the photo-degradation of phenol.     

Microstructure-Based Modeling and Estimation of Mechanical Properties of High-Carbon Steel

Herein, attempts are made to estimate the mechanical properties using microstructure-based finite element (FE) modeling and validate these results with the experimental results. The two high-carbon steel specimens are hot-rolled and air-cooled to develop ferrite–pearlite microstructures. Different characterizations are utilized to observe microstructures as well as Vickers hardness and tensile tests are carried out to determine the mechanical properties. Two high-resolution scanning electron micrographs are chosen for representative volume element-based FE analyses for modeling the mechanical behavior of ferrite–cementite microstructure. Object-oriented finite elements (OOF2) and Abaqus FEA 6.14 software are used to estimate the elastic and elastoplastic behavior assuming plane stress conditions. The correlation between cementite lamellae orientation and the predicted elastoplastic properties is investigated and compared with the experimental results. The influence of image size and mesh size on the predicted true stress–true strain behavior is discussed. The hard and brittle cementite lamellae face maximum stress while the softer ferrite matrix experiences maximum strain. It is found that strain accumulation is maximum at the interfaces of ferrite and cementite. These findings are further validated by the microvoid and crack initiation spots in the fracture surface and subsurface micrographs of broken tensile specimens.     

Growth Mechanism in Infiltration Growth Processed YBCO Composites Through Quench Studies

The mechanism of YBa₂Cu₃O_7?x (Y123/YBCO) growth and the dispersion of Y₂BaCuO₅ (Y211) particles in YBCO composites were investigated at various stages during infiltration growth process by quenching the samples in liquid nitrogen from different temperatures (1005, 1010 and 1045 °C) through peritectic reaction. Structural details of the samples were investigated using X-ray diffraction, microstructural and elemental analysis was carried out to study the distribution and composition of the matrix and Y211 inclusions at different stages. The present studies reveal that breaking down of sintered Y211 particles on application of pressure and slow cooling to 1005 °C allow sufficient infiltration of liquid phases. Peritectic reaction of liquids with Y211 particles caused rounding up of the broken sharp edges and their refinement leading to distribution of very fine Y211 precipitates in Y123 matrix.     

Introduction of Nano Ceria into Infiltration Growth Processed YBCO Superconducting Composites

Introduction of nanoparticles as flux pinning centers in yttrium barium copper oxide (YBCO/Y-123) superconductors has been extensively explored in order to improve high field current-carrying capabilities. A uniform distribution of these nanodopants throughout the superconducting matrix is the most essential and desirable. The present work provides a nonconventional approach of introducing nanoparticles into YBCO superconductors by introducing nanoparticles in Y₂BaCuO₅ (Y-211) preform and then subjecting the preform to infiltration and growth process. The Y-211 preform containing 2 wt.% ceria nanoparticles of the order of 60 nm is referred to as Ce-2 preform. The microstructure of Ce-2 preform shows a uniform distribution of nanoparticles without much interaction even to a temperature of 950 °C. At a higher concentration, a mild interaction was observed which in a way aided in keeping the nanoparticles firmly attached to Y-211 particles. Superconducting transition temperature (T _c) of Ce-2 has reduced to 86 from 92 K of pure YBCO with a broad transition. Microstructures of Ce-2 composite suggest strong interaction of ceria nanoparticles with Y-211 as well as with liquid phases which resulted in the formation of fine particles of BaCeO ₃ of the order of 200 nm, which has been observed by many investigators. It is possible that some amount of ceria might have entered into a superconducting matrix which can reduce T _c as reported earlier. The presence of low T _c phase along with a large number of fine particles have improved critical currents densities (J _c ) to a field of 9 T at 65 K. The present approach has demonstrated substantial improvement in J _c at high fields at the expense of low and broad T _c. ?AuthQuery{Q2}{The sentence “The present approach provides a scope for detail study on reaction mechanisms and infiltration process in IGP with nanoparticles” was modified to “The present approach provides a scope for detailed study on reaction mechanisms in infiltration and growth process (IGP) with nanoparticles.” Please check if the edit made appropriately retains the intended meaning of the sentence.}The present approach provides a scope for detailed study on reaction mechanisms in infiltration and growth process (IGP) with nanoparticles.