From Lattice Gauge Theories to Hydrogen Atoms

We construct canonical transformations to obtain a complete and most economical realization of the physical Hilbert space ${\cal H}^p$ of pure $SU(2)_{2+1}$ lattice gauge theory in terms of Wigner coupled Hilbert spaces of hydrogen atoms. One hydrogen atom is assigned to every plaquette of the lattice. A complete orthonormal description of the Wilson loop basis in ${\cal H}^p$ is obtained by all possible angular momentum Wigner couplings of hydrogen atom energy eigenstates $\vert n~l~m\rangle$ describing electric fluxes on the loops. The SU(2) gauge invariance implies that the total angular momenta of all hydrogen atoms vanish. The canonical transformations also enable us to rewrite the Kogut-Susskind Hamiltonian in terms of fundamental Wilson loop operators and their conjugate electric fields. The resulting loop Hamiltonian has a global SU(2) invariance and a simple weak coupling ($g^2\rightarrow 0$) continuum limit. The canonical transformations leading to the loop Hamiltonian are valid for any SU(N). The ideas and techniques can also be extended to higher dimension.Comment: 8 pages, 5 figures. minor typos corrected, minor changes in abstrac

The valuation tool user guide: monetizing Cradle to Cradle®

This User Guide outlines the object, scope and expected deliverables from the Valuation Tool component of the Cradle to Cradle ® C2C BIZZ project. It describes the compendium of subtools that have been developed comprising: i) overview of funding tools; ii) C2C investment appraisal tool; and iii) C2C value indexing tool. The underpinning methodologies, as well as their inherent strengths and limitations are also described. The C2C BIZZ project as a whole aims specifically to promote and enhance the implementation of C2C methods in business site development within North Western Europe (NWE) (PAD, p.14). It is intended to infuse C2C notions into conventional site development, restructuring and management. The primary focus of the project is on planning, building and managing of business sites with C2C credentials (PAD, p.18) using sites in Lille Metropole (La Lainiere), London (London Sustainable Industries Park) and Luxemburg (Ecoparc Windhof) as experimental fields. C2C BIZZ is not concerned with the internal operations and activities of occupiers or users of the developed site. Accordingly, the scope of the valuation tool is confined to the planning, building and management of C2C sites. The deliverable from this component is a compendium of subtools (see Figure 1 below) that may be used to analyse the financial performance of C2C credentials in business sites to aid the making of a business case for such developments and evaluating the financial incentives for particular C2C site development projects. This entire work is premised on the argument that the wider adoption of C2C principles within the built environment depends on the rate of uptake by the private sector. The private sector, being profit driven, are likely to engage in C2C site development if they are convinced of its capacity to contribute to their business goals which ultimately is a return on their investment. The tool development described in this document attempts to provide a framework for collating an evidence base that can assist in articulating the business case for C2C in business site developments

Influence of Mineralogical Nature of Aggregates on Acid Resistance of Mortar

Cement-based materials being alkaline in nature are often subjected to rapid deterioration on exposure to the aggressive acidic environments. Acids penetrate into the cement matrix causing calcium leaching and deterioration of phases leading to alteration in the microstructure. Currently, there are hardly any codes or standards available for evaluating the durability of materials to acid attack. Moreover, the literature addressing the material resistance is quite inconclusive. This paper aims to evaluate the influence of mineralogical nature of aggregates on the degradation kinetics of cement mortar when exposed to inorganic and organic acid solutions by performing a static accelerated leaching test. Cement mortar (1: 3) specimens of size 10 × 10 × 60 mm were prepared using Ordinary Portland Cement (OPC), using limestone (calcareous) aggregates and siliceous aggregates with a water to cement ratio of 0.40. After 28 days of initial curing in saturated lime water, the specimens were exposed to various concentrations of sulphuric (1 % and 3 %) and acetic acid solutions (0.25 M and 0.5 M) for a testing period of 4 months. The acid solution was replenished on a periodic basis to maintain the aggressiveness of the solution. The degradation kinetics was investigated by measuring mass changes, thickness changes, changes in pH of the acid solution and imaging using X-ray micro-tomography. Additionally, periodic abrasive action applied manually (using soft nylon brush) was used to accelerate the degradation process in case of sulphuric acid exposure and its effect was compared with the testing without the abrasive action. An attempt was also made to evaluate the changes in compressive strength and changes in dynamic modulus of elasticity of cylindrical mortar specimens (25 mm diameter and 50 mm height) on exposure to the acid solutions. The test results indicate that the performance of limestone aggregates is better on exposure to sulphuric acid and worse in case of acetic acid when compared to siliceous aggregates

Genetic variability, stability and heritability for quality and yield characteristics in provitamin A cassava varieties

Open Access Article; Published online: 25 Jan 2020Cassava is widely consumed in many areas of Africa, including Ghana, and is a major part of most household diets. These areas are characterized by rampant malnutrition, because the tuberous roots are low in nutritional value. Provitamin A biofortified cassava varieties have been developed by the International Institute for Tropical Agriculture, but adoption of these varieties in Ghana will largely depend on their agronomic performance, including fresh root yield, dry matter content, resistance to major pests and diseases, mealiness, starch content and the stability of these traits. Eight provitamin A varieties with two white checks were planted in three environments for two seasons to determine stability and variability among the varieties for important traits. There were significant variations in performance between varieties and between environments for cassava mosaic disease, root number, fresh root yield and starch content. High broad-sense heritability and genetic advance were observed in all traits, except for storage root number, and could be exploited through improvement programs. This study identified the best performing enhanced provitamin A varieties for traits that are key drivers of variety adoption in Ghana. In view of this, some varieties can be recommended for varietal release after on-farm testing. The study also showed the possibility of tapping heterosis after careful selection of parents

EFFECT OF SUCROSE AND MEDIA STRENGTH ON IN VITRO MULTIPLICATION IN SWERTIA CHIRATA BUCH.-HAM EX WALL: AN ENDANGERED MEDICINAL HERB

Objective: The present study was performed to investigate the role of varying concentrations of carbohydrate source and strengths of nutrient medium in growth and development of in vitro shoots of Swertia chirata-an endangered medicinal plant. Methods: MS medium supplemented with 6-Benzylaminopurine (4.44 µM), Indole-3 acetic acid (2.85 µM) and Adenine sulphate (271.45 µM) was used to test the efficiency of of sucrose at concentrations of 1-5% and of media strength varying from full to one-fourth. The data were analysed using analysis of variance (ANOVA) of Completely Randomized Design (CRD) in GenStat 5 Edition 3.2 for PC/Windows NT (Copyright 1995, Lawes Agricultural Trust (Rothamsted Experimental Station)) Results: Observations on axillary shoot multiplication indicated that sucrose at a concentration of 3% and MS medium in its full strength proved to be most optimal for in vitro culture multiplication. On this medium combination mean number of 11.80 shoots (after 4 w) and 18.50 shoots (after 8 w) could be obtained On sucrose free medium the shoots exhibited necrosis while at lower concentrations of 1-2% sucrose, the shoots developed were thin and unsuitable for further growth in vitro. At higher levels of sucrose in the medium, the shoots became thick and stunted. Similarly, reduction in medium strength resulted in a decline in shoot number and shoot length to an average of 6.50 shoots (1.33 cm mean length) on half strength medium and 5.60 shoots (0.88 cm mean length) on one-fourth strength; as observed after 4 w. Conclusion: The experimental findings suggest that any decline from the standard had a significant effect on the number, size and overall health of shoots developed in vitro. The conditions so standardized augment the production of healthy shoots that shall aid in subsequent rooting and survival after transplantation of tissue-culture raised plantlets