Abstract: Artisanal and small-scale gold mining (ASGM) is one of the largest sources of Hg emissions and is critical for addressing the Hg problem. Due to scarce and punctual statistics provided by governments and agencies, there is almost no accurate data on ASGM production, Hg use, and emissions. In this study, we surveyed different ap-proaches to estimate ASGM production and collected data from different sources, including academic papers and technical reports. Globally, 380-870 tonnes of gold is produced by ASGM each year, with a median value of 520 tonnes. The Hg use in the ASGM sector was estimated to be 640-1000 tonnes each year, with a median value of 892 tonnes. Consequently, 248-838 tonnes of Hg are emitted from the ASGM sector each year, with a median value of 615 tonnes. However, significant discrepancies were found in the data calculated using different ap-proaches, particularly in countries where the estimates were large, such as China. To obtain a more accurate picture of global ASGM activities, a general estimation approach combining specific studies of dominant coun-tries is necessary. For better management of ASGM in the future, developing a solid baseline and comprehensive future projection scenarios and establishing international collaboration to construct guidance on ASGM are recommended.

Abstract: Similar to the mixed-integer programming library (MIPLIB), we present a library of publicly available test problem instances for three classical types of open pit mining problems: the ultimate pit limit problem and two variants of open pit production scheduling problems. The ultimate pit limit problem determines a set of notional three-dimensional blocks containing ore and/or waste material to extract to maximize value subject to geospatial precedence constraints. Open pit production scheduling problems seek to determine when, if ever, a block is extracted from an open pit mine. A typical objective is to maximize the net present value of the extracted ore; constraints include precedence and upper bounds on operational resource usage. Extensions of this problem can include (i) lower bounds on operational resource usage, (ii) the determination of whether a block is sent to a waste dump, i.e., discarded, or to a processing plant, i.e., to a facility that derives salable mineral from the block, (iii) average grade constraints at the processing plant, and (iv) inventories of extracted but unprocessed material. Although open pit mining problems have appeared in academic literature dating back to the 1960s, no standard representations exist, and there are no commonly available corresponding data sets. We describe some representative open pit mining problems, briefly mention related literature, and provide a library consisting of mathematical models and sets of instances, available on the Internet. We conclude with directions for use of this newly established mining library. The library serves not only as a suggestion of standard expressions of and available data for open pit mining problems, but also as encouragement for the development of increasingly sophisticated algorithms.

Abstract: Chile is a world leader in copper production and is expected to reach production of around 6,237,000 tons of fine copper by 2022. On the other hand, in 2021 the production of copper by the hydrometallurgical route reached 1,509,000 tons and that of the smelting and refining route was 4,606,000 tons. Considering this production scenario, this article describes in a general way the contributions that the Chilean mining industry has made to the fulfillment of the 17 sustainable development goals, SDGs. The main advances are highlighted, besides discussing the main pending tasks to comply with the commitments made by Chile towards the international community.

Abstract: Our knowledge on reproductive traits of marine decapods is mainly based on studies concerning reproductive features of females, while the description of trends in reproductive cycles for males are scarce. Here, we analyzed the gonad development and the seasonal variation of the gonadosomatic index (GSI) of male Notocrangon antarcticus (N = 106; collected between 1986 and 1992; Weddell Sea), one of the most common caridean shrimp inhabiting the Antarctica. Male size ranged from 10.2 to 17.7 mm CL (carapax length), and individuals were significantly larger in autumn. The length of appendix masculina increased with male size, and there was no evidence for sex reversal, corroborating the assumption of dioceism in N. antarcticus. The average dry weight of the males was highest (mean 0.39) in autumn. The highest and lowest gonad dry weights were obtained from summer samples; however, we did not detect significant differences among seasons. The highest mean GSI was calculated for individuals collected in summer, and mean GSI was significantly different between summer-autumn and summer-spring, but not in autumn-spring. The GSI remained practically constant, independent of male CL. The size at sexual maturity was 13.8 mm CL, a size smaller than previously reported for N. antarcticus. The results obtained demonstrate that peak reproductive productivity of male N. antarcticus is during the summer months, when abundant nutritional resources are available.

Abstract: We introduce and motivate several variants of the bin packing problem where bins are assigned to time slots, and minimum and maximum lags are required between some pairs of items. We suggest two integer programming formulations for the general problem: a compact one and a stronger formulation with an exponential number of variables and constraints. We propose a branch-cut-and-price approach that exploits the latter formulation. For this purpose, we devise separation algorithms based on a mathematical characterization of feasible assignments for two important special cases of the problem: when the number of possible bins available at each period is infinite and when this number is limited to one and time lags are nonnegative. Computational experiments are reported for instances inspired from a real-case application of chemical treatment planning in vineyards, as well as for literature instances for special cases of the problem. The experimental results show the efficiency of our branch-cutand-price approach, as it outperforms the compact formulation on newly proposed instances and is able to obtain improved lower and upper bounds for literature instances. Summary of Contribution: The paper considers a new variant of the bin packing problem, which is one of the most important problems in operations research. A motivation for introducing this variant is given, as well as a real-life application. We present a novel and original exact branch-cut-and-price algorithm for the problem. We implement this algorithm, and we present the results of extensive computational experiments. The results show a very good performance of our algorithm. We give several research directions that can be followed by subsequent researchers to extend our contribution to more complex and generic problems.

Abstract: This paper shows how system design determines sustainability outcomes of cassava bioethanol production in Colombia. The recovery of the energy contained in by-products is recommended as compared to single product production. In particular, this study assesses the energy, greenhouse gases, water, and land use performance of alternative cassava cascades working at different scales, highlighting the implications of including anaerobic digestion technology in the chain. The centralized systems showed a poorer energy and greenhouse gases performance as compared to decentralized ones in part due to the artificial drying of cassava chips in the centralized facility. Under solar drying of cassava chips, systems with anaerobic digestion produced three to five times more energy than demanded and produced greenhouse gas savings of 0.3 kgCO(2eq) L EtOH-1. The water balance output depends upon the water reuse within the ethanol industry, which demands 21-23 L EtOH-1. In the anaerobic digestion scenarios, assuming liquid flows are treated separately, complete water recovery is feasible. Land use for cassava cultivation was calculated to be 0.27-0.35 ha tEtOH(-1). The energy and water content of the material to digest, the options for digestate reuse, and the recovery of the methane produced are major considerations substantially influencing the role of anaerobic digestion within cassava cascade configurations.

Abstract: Data in this article provides detailed information on the microbial dynamics and degradation performances in two fullscale anaerobic digesters operated in parallel for 476 days. One of them was kept at 35 degrees C for the whole experiment, while the other was submitted to sub-mesophilic (25 degrees C) conditions between days 123 and 373. Sludge samples were collected from both digesters at days 0, 80, 177, 218, 281, 353, and 462. The provided data include the operational conditions of the digesters and the characterization of the sludge samples at the physicochemical level, indicative of the digesters' degradation performance. It also includes the characterization of the sludge samples at the multiomics level (16S rRNA gene sequencing, metagenomics, and metabolomics profiling), to decipher the changes in the microbial structure and molecular activity. The 16S rDNA gene sequencing, metagenomics, and metabolomics data were generated using an IonTorrent PGM sequencer, an Illumina NextSeq 500 sequencer, and LTQ-Orbitrap XL mass spectrometer respectively. The 16S rDNA gene raw data and the metagenomics data have been deposited in the BioProject PRJEB49115, in the ENA database (https://www.ebi.ac.uk/ena/browser/view/PRJEB49115). The metabolomics data has been deposited at the Metabolomics Workbench, with study id ST002004 (DOI: 10.21228/M8JM6B). The data can be used as a source for comparisons with other studies working with data from full-scale anaerobic digesters, especially for those investigating the effect of the temperature modification. The data is associated with the research article “Metataxonomics, metagenomics, and metabolomics analysis of the influence of temperature modification in full-scale anaerobic digesters” (Puig-Castellvi et al [1]). (c) 2022 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Abstract: Adaptive phenotypic plasticity, has been recognized as an important strategy by which organisms maximize fitness in variable environments, which vary through development. A disassociation among stages should represent a null effect of the environment experienced during early ontogeny in the expression of adult traits. Food quality greatly influences survival, development and reproduction in many arthropod herbivores. We examined the effects of diet protein in physiological and life-history traits in the yellow mealworm beetle Tenebrio molitor through ontogeny. We established four experimental treatments: Low Protein (LP), Low Protein Control (LPC), High Protein (HP), and High Protein Control (HPC) with recently eclosioned larvae each. Individuals were maintained on the same diet or transferred to the opposite diet for all pupae period and almost all adult period. Contrary to the expected, the duration of life-cycle, larval growth rate and body mass in T molitor were similar in diet treatments. We found intra-individual trade-offs between environmental diet (rich or poor in protein content) during larval phase and egg number. Larvae fed on a protein-deficient diet exhibited significantly higher respiratory rates than larvae fed on a rich protein diet. Compensatory feeding could act in T molitor larvae indicating differences in metabolism but not in growth rate, body mass and life-cycle characteristics. Our results demonstrate the plasticity of reproductive and metabolic traits and life-cycle characteristics of T molitor and how changes that occur in relation to diet can have profound effects on progeny and female fitness.