1ft 'J .Ó AP E418 Superconductivity ExperimentS uperconductivity may beome one of the most signifcant inovations of mom times. Ths is a result of very recent discoveries of high temperature superconductorswhich may revolutionize everything from electrcal generation and transmission to high-speed cQmputers to controlled fusion generatig plants.In ths experiment, you will investigate the superconductivity of the new Y -Ba-Cu-O compound system as a function of temperature and magnetic field. The most important question should should answer is "What is the resistance of the superconductor as the temperatu and applied magnetic field ar changed?" Other questions which you wil not be able to answer are related to the determination of curent density which can pass through the material and the mechanical strength and elasticity of the material.Attached to these notes are some articles which describe aspects of superconductivity and the results of recent measurements of the Y -Ba-Cu-O compound made by Prof. M. K. Wu and co-workers. These wil provide background for the experiments that you wil be penormg. Pay paricular attention to Prof. Wu's aricle. Their measurements are identical to those that you can obtan with the equipment supplied in the laboratory. Next, look over the description of tye 1 and j , ty.e 2 superconductors given by Gennes in Superconductivity in Metals and Alloys.o.f\1. , l' -Type 1 superconductors have a "correlation length" between. conduction electrons ((sheri (denoted by the symbol, ÇO) much longer than the magnetic field penetration length ( denoted by Â.). They generally have a very abrupt crtical field, He, below which the P-i1lèt material is superconducting and excludes all magnetic flux. (H e is a function of temperature.) This "penect diamagnetîsm" is charaèteristic of the superconducting state. Type 2 superconductors have Â. ~ Ço and have a more gradual transition to this superconducting state. They are described by thee critical magnetic fields. Below Hci (the lowest critical field), a typ 2 superconductor has no resistace and, like a type 1 superconductor, excludes flux. Between H c1 and H e2, the resistance is very low, but finite, and the superconductor parally excludes flux. Between He2 and He3, the resistance is low, but no flux is excluded. Finally, above the highest of the three crtical fields, He3. the material is no longer superconducting. DescrI ptionThe Y -Ba-Cu-O compound becomes superconducting between 77 and 85 eK.This makes the cryogenic aspects of these experiment very easy compared with experiments using more conventional superconductors that require temperatures below 22 eK. Liquid nitrogen is relatively inexpensive and a styrofoam thermos is al that is required to store it for several hours.-We have built three LN2 containers for you, and these are large enough to hold stainless-steel and copper "sample stands". The sample stands cool the 1 \, W£t.~ i-superconducting sample and provide a stable base to make your measurements. Also, attached to each sample is a calibrated t...

Seawater desalination is a promising approach to satisfying water demand in coastal countries suffering from water scarcity. To clarify its potential future global scale, we perform a detailed investigation of the economic feasibility of desalination development for different countries using a feasibility index (F i ) that reflects a comparison between the price of water and the cost of production. We consider both past and future time periods. For historical validation, F i is first evaluated for nine major desalination countries; its variation is in good agreement with the actual historical development of desalination in these countries on both spatial and temporal scales. We then simulate the period of 2015-2050 for a Shared Socioeconomic Pathway (SSP2) and two climate scenarios. Our projected results suggest that desalination will become more feasible for countries undergoing continued development by 2050. The corresponding total global desalination population will increase by 3.2-fold in 2050 compared to the present (from 551.6 × 10 6 in 2015 to 1768 × 10 6 ). The major spread of seawater desalination to more countries and its availability to larger populations is mainly attributed to the diminishing production costs and increasing water prices in these countries under the given socioeconomic/climate scenarios.

Arabinogalactan proteins (AGPs) are highly glycosylated proteins that play pivotal roles in diverse developmental processes in plants. Type-II AG glycans, mostly O-linked to the hydroxyproline residues of the protein backbone, account for up to 95% w/w of the AGP, but their functions are still largely unclear. Cotton fibers are extremely elongated single-cell trichomes on the seed epidermis; however, little is known of the molecular basis governing the regulation of fiber cell development. Here, we characterized the role of a CAZy glycosyltransferase 31 (GT31) family member, GhGalT1, in cotton fiber development. The fiber length of the transgenic cotton overexpressing GhGalT1 was shorter than that of the wild type, whereas in the GhGalT1-silenced lines there was a notable increase in fiber length compared with wild type. The carbohydrate moieties of AGPs were altered in fibers of GhGalT1 transgenic cotton. The galactose: arabinose ratio of AG glycans was higher in GhGalT1 overexpression fibers, but was lower in GhGalT1-silenced lines, compared with that in the wild type. Overexpression of GhGalT1 upregulates transcript levels of a broad range of cell wall-related genes, especially the fasciclin-like AGP (FLA) backbone genes. An enzyme activity assay demonstrated that GhGalT1 is a β-1,3-galactosyltransferase (β-1,3-GalT) involved in biosynthesis of the β-1,3-galactan backbone of the type-II AG glycans of AGPs. We also show that GhGalT1 can form homo- and heterodimers with other cotton GT31 family members to facilitate AG glycan assembly of AGPs. Thus, our data demonstrate that GhGalT1 influences cotton fiber development via controlling the glycosylation of AGPs, especially FLAs.

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This article discusses how to efficiently and completely solve a bi‐objective pavement maintenance and rehabilitation‐scheduling problem, which aims at optimizing two objectives of pavement condition improvement and budget utilization in a simultaneous manner. This problem may be addressed by the weighting method, constraint method, ranking method, and various metaheuristic methods. However, none of these methods can guarantee the complete Pareto‐optimal solution set, which would potentially lead to suboptimal decisions. In this article, a parametric method is suggested to solve the bi‐objective pavement maintenance and rehabilitation‐scheduling problem. The effectiveness and efficiency of the parametric method is investigated and demonstrated through a case study using the real‐world data set from the Dallas District's Pavement Management Information System. A performance comparison between the widely used weighting method and the parametric method clearly justifies the computational advantages of the parametric method.