Seperation & Recovery of Cu and Zn by Solvent Extraction - Electrowinning from the Sulphate Leach Liquor of Complex Sulphide Ore

Complex sulphide ores containing Cu, Zn, and Pb form an important source of base metals in India. The sulphides are first floated out and the buck sulphide concentrates are subjected to roasting in fluidised bed reactor, where the metal sulphides are converted to setluble sulphates. The roasted mass is leached with water when copper and zinc get solubilised leaving lead in the insoluble residue. The solution is processed further by solvent extraction technique to extract copper quantitatively using the commercial extractant, LIX 64N, The zinc remains unextracted and can be recovered by electro-winning. This paper describes the process developed and the results obtained on recovery of electrolytic grade- copper and zinc

First documented occurrences of Cladonia krogiana and C. rangiformis in north America

Funding Information: We thank Scott LaGreca for providing a photograph of the specimen of C. rangiformis at BM that was reportedly collected on Bermuda; Bruce Allen and the late Ronald Pursell for allowing us to cite their collections of Homalothecium sericeum from Newfoundland; Zdeněk Palice for enabling us to compare his collection of C. krogiana from the Czech Republic with material from Canada and Norway; Nathalie Djan-Chékar (Provincial Museum of Newfoundland and Labrador) for co-organizing the 2007 Tuckerman Workshop; and Irwin Brodo, James Lendemer, and an anonymous reviewer for their helpful comments on the manuscript. Permission to collect lichens in Fundy National Park and New River Beach Provincial Park (NRBPP) was approved by Renee Wissink (Parks Canada) and Martin MacMullin (NB Department of Tourism, Heritage, and Culture). Fieldwork in NRBPP and follow-up studies were supported in part by the New Brunswick Wildlife Trust Fund and the New Brunswick Environmental Trust Fund. Publisher Copyright: © 2021, New York Botanical Garden. All rights reserved.– Cladonia krogiana, previously known only from Norway and the Czech Republic, is reported here for North America from two localities near the Bay of Fundy, New Brunswick, Canada. It occurs there on open, rocky banks of clear, free-flowing rivers, habitats similar to those in which it has been found in Norway. We also document the occurrence of C. rangiformis in North America, based on collections from two localities on the southwest coast of Conception Bay, on the Avalon Peninsula of the island of Newfoundland, Canada. It is possibly an accidental, but naturalized, introduction in this area, where European settlement began in the early 1600s. A molecular phylogenetic analysis confirmed the identity of one of the Newfoundland specimens. The IGS rDNA haplotype to which it belongs is the same as the most widely distributed haplotype of C. rangiformis in Europe and Macaronesia. Previous reports of C. rangiformis for continental North America are based on misidentifications. A 19th century collection reportedly made on the island of Bermuda, while correctly identified, is of uncertain provenance.Peer reviewe

Feed intake and performance of growing lambs raised on concentrate-based diets under cafeteria feeding systems

8 pages, 4 tables, 3 figures.--Two trials were undertaken to study the effects of cafeteria feeding systems on the feed intake, animal performance and carcass characteristics of growing lambs, Trial 1 was designed to compare conventional and cafeteria feeding systems in terms of the growth of individually reared lambs. For this assay, 26 weaned Merino lambs (15.5 +/- 0.20 kg live weight) were assigned to three dietary treatment groups: (1) a control group fed barley straw and commercial concentrate under a conventional feeding system, (2) group W100S, fed soya-bean meal, whole barley grain and a mineral-vitamin supplement under a cafeteria feeding system, and (3) group W100S-T, fed as in the W100S treatment but allowing the lambs an initial training period so they could learn to identify a number of feeds. The feeding system had no significant effect (P > 0.05) on either average daily live-weight gain, carcass weight, or carcass conformation. The food conversion ratio was lower (P < 0.05) for the cafeteria-reared animals (2.9 +/- 0.16 v. 2.5 +/- 0.08g dry-matter intake per g average daily gain) than those of the control group. This might be related to the higher crude protein intake seen in the cafeteria groups (150 +/- 5.6 v. 208 +/- 12.5g per animal per day, P < 0.001). In trial 2, cafeteria and conventional feeding system were compared in terms of the growth of feedlot lambs. Two hundred weaned Merino lambs (13.1 +/- 0.10 kg) were divided into two experimental groups: (1) a control group, offered commercial concentrate and barley straw, and (2) a cafeteria group fed the same diet as W100ST in trial 1. The average daily gain (282 +/- 5.8 and 309 6.5, P 0.001) in the conventional than in the cafeteria system lambs. The use of cafeteria systems for fattening lambs can improve the feed conversion efficiency and body growth rate over those achieved with conventional feeding systems, although the crude protein intake in these systems seems to be in excess of requirements.This research was funded by Magnus S.A., with additional support from the collaboration between Caja España and the Estación Agrícola Experimental (CSIC, Spanish National Research Council).Peer reviewe

Large contribution of supercooled liquid clouds to the solar radiation budget of the Southern Ocean

The Southern Ocean is a critical region for global climate, yet large cloud and solar radiation biases over the Southern Ocean are a long-standing problem in climate models and are poorly understood, leading to biases in simulated sea surface temperatures. This study shows that supercooled liquid clouds are central to understanding and simulating the Southern Ocean environment. A combination of satellite observational data and detailed radiative transfer calculations is used to quantify the impact of cloud phase and cloud vertical structure on the reflected solar radiation in the Southern Hemisphere summer. It is found that clouds with supercooled liquid tops dominate the population of liquid clouds. The observations show that clouds with supercooled liquid tops contribute between 27% and 38% to the total reflected solar radiation between 40° and 70°S, and climate models are found to poorly simulate these clouds. The results quantify the importance of supercooled liquid clouds in the Southern Ocean environment and highlight the need to improve understanding of the physical processes that control these clouds in order to improve their simulation in numerical models. This is not only important for improving the simulation of present-day climate and climate variability, but also relevant for increasing confidence in climate feedback processes and future climate projections

An evaluation of clouds and precipitation in convection-permitting forecasts for South Africa

Since 2016, the South African Weather Service (SAWS) has been running convective-scale simulations to assist with forecast operations across southern Africa. These simulations are run with a tropical configuration of the Met Office Unified Model (UM), nested in the Met Office global model, but without data assimilation. For November 2016, convection-permitting simulations at 4.4-km and 1.5-km grid length are compared against a simulation at 10-km grid length with convection parametrization (the current UM global atmosphere configuration) to identify the benefits of increasing model resolution for forecasting convection across southern Africa. The simulations are evaluated against satellite rainfall estimates, CloudSat vertical cloud profiles, and SAWS radar data. In line with previous studies using the UM, on a monthly time scale, the diurnal cycle of convection and the distribution of rainfall rates compare better against observations when convection-permitting model configurations are used. The SAWS radar network provides a three-dimensional composite of radar reflectivity for northeast South Africa at 6-minute intervals, allowing the evaluation of the vertical development of precipitating clouds and of the timing of the onset of deep convection. Analysis of four case study days indicates that the 4.4-km simulations have a later onset of convection than the 1.5-km simulations, but there is no consistent bias of the simulations against the radar observations across the case studies

Can reducing the incoming energy flux over the Southern Ocean in a CGCM improve its simulation of tropical climate?

Atmosphere-ocean general circulation models (CGCMs) show important systematic errors. Simulated precipitation in the tropics is generally overestimated over the oceans south of the equator, and stratocumulus (SCu) clouds are underestimated above too warm sea surface temperatures (SSTs). In the extratropics, SSTs are also too warm over the Southern Ocean. We argue that ameliorating these extratropical errors in a CGCM can result in an improved model's performance in the tropics depending upon the success in simulating the sensitivity of SCu to underlying SST. Our arguments are supported by the very different response obtained with two CGCMs to an idealized reduction of solar radiation flux incident at the top of the atmosphere over the Southern Ocean. It is shown that local perturbation impacts are very similar in the two models but that SST reductions in the SCu regions of the southern subtropics are stronger in the model with the stronger SCu-SST feedbacks.NOAA's Climate Program Office, Climate Variability and Predictability Program Award. Grant Number: NA14OAR4310278. European Union Seventh Framework Programme. Grant Numbers: FP7/2007–2013, 60352Peer reviewe

Monitoring rumen environment in finishing Lidia bulls

Objective. The aim of this work was to characterize the changes in rumen pH and temperature in finishing Lidia breed bulls reared on pasture and fed a total mixed ration (TMR). Materials and methods. Five 4-year-old Lidia bulls received approximately 10 kg of the TMR per animal and day in the morning. Bulls could move freely in a 17-ha fenced area and express normally their feeding behaviour. Internal wireless boluses were used to collect pH and temperature values every 10 minutes throughout the measurement period. Results. Average daily pH was 6.2. Average and maximum daily temperatures were not high enough to be indicative of disease (infections of other pathologies). Conclusions. When rations and feeding systems are appropriately managed, Lidia bulls can be supplemented with concentrates in the finishing stages of their productive cycle without impairing the rumen environment. Objetivo. El presente trabajo pretendió caracterizar las modificaciones que se producen en el pH y la temperatura ruminal de los toros de lidia, criados con un sistema de alimentación basado en el suministro de una mezcla unifeed seca durante la etapa de acabado. Materiales y métodos. Se utilizaron 5 toros cuatreños de la raza de Lidia alimentados con, aproximadamente, 10 kg/animal y día de la mezcla unifeed a primera hora de la mañana. Los toros disponían de un espacio cercado de 17 ha, que les permitiría expresar sus patrones de comportamiento de pastoreo en libertad con plena normalidad. El pH y la temperatura ruminal se midió de forma continua utilizando una sonda interna sin cables. Resultados. El pH medio fue de 6.20. Ni los valores de temperatura ruminal medios ni los máximos registrados son excesivamente altos como para ser indicativos del desarrollo de patologías o infecciones que pudieran afectar al estado de los animales. Conclusiones. Mediante el manejo adecuado de las raciones y del sistema de alimentación, puede llevarse a cabo una suplementación con alimentos concentrados para toros de lidia en la fase de remate de manera adecuada y respetuosa con su ambiente ruminal

The impact of equilibrating hemispheric albedos on tropical performance in the HadGEM2-ES coupled climate model

The Earth's hemispheric reflectances are equivalent to within ± 0.2 Wm-2, even though the Northern Hemisphere contains a greater proportion of higher reflectance land areas, because of greater cloud cover in the Southern Hemisphere. This equivalence is unlikely to be by chance, but the reasons are open to debate. Here we show that equilibrating hemispheric albedos in the Hadley Centre Global Environment Model version 2-Earth System coupled climate model significantly improves what have been considered longstanding and apparently intractable model biases. Monsoon precipitation biases over all continental land areas, the penetration of monsoon rainfall across the Sahel, the West African monsoon 'jump', and indicators of hurricane frequency are all significantly improved. Mechanistically, equilibrating hemispheric albedos improves the atmospheric cross-equatorial energy transport and increases the supply of tropical atmospheric moisture to the Hadley cell. We conclude that an accurate representation of the cross-equatorial energy transport appears to be critical if tropical performance is to be improved