EinExprs: Contraction Paths of Tensor Networks as Symbolic Expressions

Tensor Networks are graph representations of summation expressions in which vertices represent tensors and edges represent tensor indices or vector spaces. In this work, we present EinExprs.jl, a Julia package for contraction path optimization that offers state-of-art optimizers. We propose a representation of the contraction path of a Tensor Network based on symbolic expressions. Using this package the user may choose among a collection of different methods such as Greedy algorithms, or an approach based on the hypergraph partitioning problem. We benchmark this library with examples obtained from the simulation of Random Quantum Circuits (RQC), a well known example where Tensor Networks provide state-of-the-art methods.Comment: 4 pages, 5 figures, submitted to JuliaCon Proceedings 202

A selectivity index for public-private partnership projects in the urban water and sanitation sector in Latin America and the caribbean

The rapid urban development, the Agenda 2030, the climate change adaptation and the COVID 19 crisis high light the need to increase investment in public infrastructure and improve water supply and sanitation services. For this, an alternative to traditional public procurement is the participation of the private sector under the public-private partnership (PPP) model. The objective of this article is to develop a tool based on critical success factors (CSFs) that allows for evaluation during early stages of the convenience of developing a PPP project for W&S in urban areas of Latin America and the Caribbean. The index was developed based on literature review (779 variables), review of cases (20 variables) and expert opinion to assign them an estimated value of importance. The results were analysed by exploratory and confirmatory factor analysis, selecting 17 main variables grouped into 6 CSFs, the most relevant of which are Convenience, Certainty, Leadership, Attraction, Performance and Reliability. The application of this index allows an early assessment of the feasibility of a PPP project and/or the selection of the alternatives with the best chances of success. On the other hand, this study contributes to the international discussion on the most relevant elements related to the success of PPP in W&S projects

Procesamiento del rechazo de banano para la producción de harina como proceso alternativo para alimentos de cerdos

This project enters the design and construction of equipment such as the solar dryer and the artisan mill in order to elaborate flour of banana waste. The problematic situation of banana plantations and their waste was previously assessed during this project, which can be used as pig feed, the artisanal equipment established an alternative to use banana waste for flour production and taking into account the requirements established by the technical regulations of processed foods and food processing plants issued by MAGAP in conjunction with AGROCALIDAD. That one may concentrate this objective it starts drying the banana previously sliced, for which the solar dryer is used; once the optimum dehydration has been obtained, it is proceeded to grind with the built mill, thus determining the banana flour, the same one that was subjected to a physical-chemical study, obtaining the somewhat low nutritional characteristics; with this result, the nutritional content was improved by adding the wheat bran that allowed to recover the optimal nutritional percentages, resulting in: total humidity 12.07%, dry matter 87.93%, proteins 11.53%, fiber 2.09%, fat 1.25%, ash 3.89%, organic matter 96.11%.En el presente proyecto tecnológico se demuestra la elaboración de harina para cerdos envase al rechazo de banano, por medio de la construcción de equipos artesanales como el secador solar y el molino artesanal. Para el desarrollo de este proyecto, previamente se evaluó la situación problemática de las plantaciones de banano, que desconocen las diversas alternativas que se pueden realizar con el rechazo de banano. Con la ayuda de los equipos artesanales mencionados se establece una alternativa del uso del rechazo de banano para la elaboración de harina, tomando en cuenta los requerimiento establecidos por las normativas técnicas de alimentos procesados, plantas procesadoras de alimentos establecimientos de distribución, comercialización, transporte de alimentos, establecimientos de alimentación colectiva, expedido por el Ministerio de Agricultura, Ganadería, Acuacultura y Pesca en con junto con AGROCALIDAD, mediante la cual se realizaron análisis físico-químicos de la materia procesada. A través de la harina de banano se optó por realizar una formulación con el afrechillo para mejorar sus porcentajes nutricionales, dando como resultado un balanceado apto para la alimentación. Con la formulación realizada se garantiza que los estándares nutricionales de los cerdos son aptos para el consumo, por lo tanto, el producto será aceptado por los porcicultores, permitiendo optimizar costos operativos y economizar el bolsillo del porcicultor con la adquisición de un balanceado elaborado de manera artesanal

Comparative study of limestone calcined clay cement produced with mechanically activated kaolin and calcined kaolin

Limestone calcined clay cement (LC3) is a promising solution for mitigating CO2 emissions in cement production by substantially replacing clinker with widely available supplementary cementitious materials. While calcination is the conventional method for activating clay, there is a growing interest in mechanical activation. Incorporating mechanically activated kaolin into LC3 formulation would offer a novel approach to producing this cement. This study aims to assess the impact of replacing calcined clay (CC) with mechanically activated clay (MC) in LC3 properties and relevant features. Accordingly, LC3 with MC substitutions ranging from 0 to 100 wt% were formulated. The resulting cements were characterised to evaluate their physicochemical properties, microstructure, strength, and pore distribution. LC3 incorporating MC exhibited comparable crystalline and amorphous phases to LC3 containing CC. However, the incorporation of MC accelerated hydration, leading to the earlier formation of carboaluminates and consumption of portlandite, alongside enhanced compressive strength at early curing stages. At 28 days, LC3 with 100 wt% of MC displayed similar compressive strength (42 MPa) to LC3 with 100 wt% of CC (40 MPa) with comparable pore distribution and microstructure. These findings validate MC's potential to substitute CC in LC3, offering an alternative for activating clay