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Information about decadal to millennial variability of El Nino Southern Oscillation (ENSO) is fundamental for the assessment of ENSO responses to natural and anthropogenic forcings. Despite a growing number of ENSO reconstructions, the overall picture of Holocene ENSO variability is inconsistent. Here, we revisit the iconic Holocene ENSO sediment record of Lake Pallcacocha, Ecuador (Rodbell et al., 1999). We asked: (i) How coherent are the records of clastic layers (flood layers) in the sediments of Lake Pallcacocha and adjacent Lake Fondococha? (ii) What are the synoptic-scale atmospheric conditions that lead to intense precipitation and, potentially, to alluvial activity promoting the deposition of clastic layers in these lakes? (iii) Is intense precipitation in this area associated with El Nino, or not? We analyzed clastic layers in Late-Holocene sediments from multiple cores in Lakes Pallcacocha and Fondococha from Cajas National Park, southern Ecuadorian Andes. Additionally, we investigated precipitation data from 13 nearby meteorological stations to test if intense precipitation (percentiles P0.95, P0.99, P0.995) is predominantly related to El Nino conditions or not (based on 15 different ENSO indices). Our results show that the absolute flood frequencies (clastic layers per 100 years) differ substantially from lake to lake. This indicates that the frequency of clastic layers reflects different sensitivities (thresholds of precipitation) of the catchments to alluvial activity. 210Pb ages suggest that neither the 1982/83 nor the 1997/98 very strong El Ninos produced clastic layers comparable to those found in the late Holocene. Daily precipitation records from meteorological stations close to Lake Pallcacocha including a high-altitude station from the western slope of the Andes did not show unusually high precipitation during the super El Nino 2015/16. We further find that intense precipitation in this area occurs at roughly equal probability under El Nino, La Nina and neutral conditions. Although the spectral properties of the late Holocene clastic layers in Lake Pallcacocha fall into the typical ENSO frequency band, we do not find evidence in the recent sediments and the meteorological data that would support a diagnostic link between alluvial activity in Lake Pallcacocha and strong El Nino events. Our data do not support the idea that the (late) Holocene flood record of Lake Pallcacocha is a conclusive paleo-El Nino record

ABSTRACT This study aims to investigate the hydrothermal co-liquefaction of rice straw (RS) and waste cooking-oil model compound (WCOM) under sub-critical conditions for the optimum bio-crude yield and conversion. Effects of temperature, catalyst (K2CO3), residence time and mass ratios of RS to WCOM on products’ distribution were examined and the reaction mechanism for co-liquefaction of RS and WCOM was also explored. The highest bio-crude yield (88.77%) was obtained when mass ratio of RS to WCOM was 1:3 at 300 ℃, 10 min and in absence of K2CO3. When the mass ratio was 3:1, 1:1 and 1:3, the synergistic effect approached 14.38%, 11.38% and 12.84%, respectively. WCOM could improve the overall conversion rate of RS during co-liquefaction. GC-MS analysis suggested that the bio-crude contained large amounts of fatty acids and smaller amounts of phenols and ketone aldehydes. Co-liquefaction was found effective to improve the qualitative and quantitate features of products from biomass.

The European Union is currently in the process of transformation toward a circular economy model in which different areas of activity should be integrated for more efficient management of raw materials and waste. The wastewater sector has a great potential in this regard and therefore is an important element of the transformation process to the circular economy model. The targets of the circular economy policy framework such as resource recovery are tightly connected with the wastewater treatment processes and sewage sludge management. With this in view, the present study aims to review existing indicators on resource recovery that can enable efficient monitoring of the sustainable and circular solutions implemented in the wastewater sector. Within the reviewed indicators, most of them were focused on technological aspects of resource recovery processes such as nutrient removal efficiency, sewage sludge processing methods and environmental aspects as the pollutant share in the sewage sludge or its ashes. Moreover, other wide-scope indicators such as the wastewater service coverage or the production of bio-based fertilizers and hydrochar within the wastewater sector were analyzed. The results were used for the development of recommendations for improving the resources recovery monitoring framework in the wastewater sector and a proposal of a circularity indicator for a wastewater treatment plant highlighting new challenges for further researches and wastewater professionals.

Abstract This paper presents the computational fluid dynamics (CFD) analysis of the flow inside a cyclone with the division of gas and particle flow in a vortex finder. A doubled vortex finder which was used for the investigations divides gas cleaned in the cyclone into two parts. The gas elements exiting the cyclone through the external tube (i.e. bleed flow) were 20%, 40% and 57%, respectively. The particle size distribution of both streams has also been determined. The Reynolds-averaged Navier–Stokes equations with the Reynolds stress turbulence model (RSM) were used for the analysis. The Lagrangian method was employed to track the particle motion and calculate the cyclone and the efficiencies of division. The conducted division of exhaust gas practically does not change the gas flow and the efficiency of the cyclone. However, the particle size distribution of both gas streams is different. The difference in the particle size can be used for subsequent cleaning of bleed flow in a bag filter and for improving the efficiency of the modified system of the cyclone with an additional filter. Such a system would remove more dust than dividing the gas stream alone.

Energy efficient execution of scientific applications requires insight into how HPC system features affect the performance and power of the applications. In this paper, we analyze and model performance and power characteristics of hybrid MPI/OpenMP LULESH (Livermore Unstructured Lagrange Explicit Shock Hydrodynamics) miniapps under various workloads using MuMMI (Multiple Metrics Modeling Infrastructure). Output from these models is then used to guide code optimizations of performance and power. Our optimization methods result in performance improvement and energy savings of up to approximately 10%. Further, based on the insight learned from our models and measurements under various workloads, applying DCT (Dynamic Concurrency Throttling) to the optimized codes results in the energy savings by 43.12% to 58.30% for different problem sizes compared with the baseline results on 27 nodes with 32 threads per node on a 36-node Intel Haswell testbed cluster Shepard.

An effective method of low-enthalpy energy acquiring from waters pumped out from mines in a low-temperature geothermal power plant with the capacity of 5 MWt has been presented. The geothermal power plant will allow to achieve favorable energy and ecological effects. It can be built in all underground mines in the Upper Silesian Coal Basin (USCB) that ensure access to the water stream in a suitably long period of time, minimum a dozen or so years. Cooled waters can be injected back into mine workings — however, this depends on local geological and mining conditionings. With the aim of quick selection of installation capacity a nomogram was constructed to determine the parameters of the geothermal power plant installations.

This paper deals with the evolution of concentration field at a single membrane system. Concentration field evolution is described by concentration effect of stable boundary layers, which originate in this system. The concentration effect of boundary layers (CBLE) is studied experimentally on the basis concentration profiles obtained from computer analysis of interferometric pictures of near-membrane regions. Besides experimental results, we also report theoretical investigations and numerical calculations of this effect for two models of membranes (an infinite thin wall and the wall of thickness l). Evolution of concentration field at different distances from membrane surface describes accurately the spatio-temporal structure of the concentration boundary layers (CBLs). Results have shown that their spatial structure is fully established and these layers develop diffusively.