119 research outputs found

    Cache-only memory architectures

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    Adsorption of representative pharmaceutical compounds from hospital wastewater by carbon materials

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    Pharmaceuticals are a class of emerging environmental contaminants that are extensively and increasingly being used in human and veterinary medicine. The worldwide consumption of these substances has increased in both hospitals and households, which represents a major concern in terms of their potential harmful effects on the environment and human health [1]. Thus, fluoroquinolone antibiotics are widely used in human medicine and animal breeding for preventing and curing diseases. Ciprofloxacin is a wide-spectrum fluoroquinolone antibiotic extensively used in the world, which can generate high contributions to public sewers. Meanwhile, carbamazepine, one of the most widely prescribed psychoactive drugs, shows important endocrine disrupting effects and it is frequently detected in high concentrations in both WWTPs effluents and river water. Because of the removal efficiency of these compounds in the conventional wastewater treatment plants is not complete (ranging from 7-8% for carbamazepine), it is necessary the implementation of tertiary technologies in order to achieve WWTPs effluents with a better quality. Adsorption onto carbon materials has proven as an efficient treatment in the removal of a broad spectrum of micro-pollutants. This work has been focused on the study of equilibrium adsorption of carbamazepine (CBZ) and ciprofloxacin (CPX) from ultrapure water at 30 ºC using carbonaceous materials. Commercial carbon materials (AC-F400 activated carbon, multi-walled carbon nanotubes, MWNT, and carbon nanofibers, CNF) and lab-synthesized activated carbons from peach stones (AC-PS) and rice husk (AC-RH) as precursors have been used. Moreover, carbon adsorbents have been used to treat a real hospital wastewater containing 55 different pharmaceutical compounds. Among them, both CBZ and CPX were found at concentrations of 162.55 and \u3e 40 ng.L-1, respectively. The removal efficiency of quality macroscopic parameters (Total Organic Carbon concentration, TOC, Total Nitrogen concentration, TN, carbonates, CO32-, and aromaticity) and each of the pharmaceuticals contained in the wastewater was evaluated. Large adsorption capacities of CBZ and CPX (around 240 and 200 mg.g-1) were found in 4 hours, using adsorbent doses ranging from 2-3 g.L-1, natural pH, temperature of 30 ºC and stirring rate of 250 rpm. In addition, competitive adsorption experiments using both pollutants in ultrapure water have been performed. The bi-component adsorption systems were reasonably well-fitted by the extended Freundlich model equation. In the treatment of the hospital wastewater, a maximum TOC reduction of 96.5% ([TOC]0 = 110 mg L-1) was achieved by adsorption onto AC-RH activated carbon, since all the studied macroscopic parameters were too efficiently removed. Moreover, by the adsorption treatment, the complete disappearance of all the pharmaceutical compounds (except two of them) was observed. References [1] S. Ortiz de García, G. Pinto Pinto, P. García Encina, R. Irusta Mata, Consumption and occurrence of pharmaceutical and personal care products in the aquatic environment in Spain, Sci. Total Environ. 444 (2013) 451–465

    Establishing a framework for dynamic risk management in 'intelligent' aero-engine control

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    The behaviour of control functions in safety critical software systems is typically bounded to prevent the occurrence of known system level hazards. These bounds are typically derived through safety analyses and can be implemented through the use of necessary design features. However, the unpredictability of real world problems can result in changes in the operating context that may invalidate the behavioural bounds themselves, for example, unexpected hazardous operating contexts as a result of failures or degradation. For highly complex problems it may be infeasible to determine the precise desired behavioural bounds of a function that addresses or minimises risk for hazardous operation cases prior to deployment. This paper presents an overview of the safety challenges associated with such a problem and how such problems might be addressed. A self-management framework is proposed that performs on-line risk management. The features of the framework are shown in context of employing intelligent adaptive controllers operating within complex and highly dynamic problem domains such as Gas-Turbine Aero Engine control. Safety assurance arguments enabled by the framework necessary for certification are also outlined

    Influencia de la reserva cognitiva en la calidad de vida en sujetos con enfermedad de Alzheimer

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    La calidad de vida (CV) se define como la percepción personal que un individuo tiene de su situación vital. Dentro de los factores que pueden influir en la CV, se encuentra la Reserva Cognitiva (RC), que podría entenderse como la capacidad del cerebro para hacer frente al daño cerebral generado por la patología, mediante procesos cognitivos preexistentes o compensatorios. El objetivo principal de este estudio, consiste en analizar, como influye la RC en la auto-percepción subjetiva de la CV en sujetos diagnosticados de Enfermedad de Alzheimer (EA) y comprobar si existen perfiles diferenciales en función de la sintomatología depresiva y el estado cognitivo de los mismos. La muestra utilizada estaba formada por 112 sujetos que se distribuyeron en dos grupos: uno de 74 sujetos diagnosticados de EA, y otro de 38 sujetos sanos. Se ha utilizado el cuestionario SF-36 para evaluar la CV. En relación a la variable RC, destacar que los sujetos con mayor RC, puntuaron más alto en cada una de las dimensiones del SF-36. La RC podría ser una fuente de influencia en la percepción de la CV de las personas con EA, en la medida en que sus diversos componentes conducirían a la consecución de una capacidad funcional más óptima y una aceptación del estado cognitivo

    Critical review of technologies for the on-site treatment of hospital wastewater: From conventional to combined advanced processes

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    This review aims to assess different technologies for the on-site treatment of hospital wastewater (HWW) to remove pharmaceutical compounds (PhCs) as sustances of emerging concern at a bench, pilot, and full scales from 2014 to 2020. Moreover, a rough characterisation of hospital effluents is presented. The main detected PhCs are antibiotics and psychiatric drugs, with concentrations up to 1.1 mg/L. On the one hand, regarding the presented technologies, membrane bioreactors (MBRs) are a good alternative for treating HWW with PhCs removal values higher than 80% in removing analgesics, anti-inflammatories, cardiovascular drugs, and some antibiotics. Moreover, this system has been scaled up to the pilot plant scale. However, some target compounds are still present in the treated effluent, such as psychiatric and contrast media drugs and recalcitrant antibiotics (erythromycin and sulfamethoxazole). On the other hand, ozonation effectively removes antibiotics found in the HWW (>93%), and some studies are carried out at the pilot plant scale. Even though, some families, such as the X-ray contrast media, are recalcitrant to ozone. Other advanced oxidation processes (AOPs), such as Fenton-like or UV treatments, seem very effective for removing pharmaceuticals, Antibiotic Resistance Bacteria (ARBs) and Antibiotic Resistance Genes (ARGs). However, they are not implanted at pilot plant or full scale as they usually consider extra reactants such as ozone, iron, or UV-light, making the scale-up of the processes a challenging task to treat high-loading wastewater. Thus, several examples of biological wastewater treatment methods combined with AOPs have been proposed as the better strategy to treat HWW with high removal of PhCs (generally over 98%) and ARGs/ARBs (below the detection limit) and lower spending on reactants. However, it still requires further development and optimisation of the integrated processes.Comunidad de Madri

    Critical review of technologies for the on-site treatment of hospital wastewater: From conventional to combined advanced processes

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    In this work, a raw and low cost mineral, ilmenite (FeTiO3), has been tested for the first time as a photocatalyst paired with peroxymonosulfate (HSO5-; PMS) for the inactivation of Enterococcus faecalis as an alternative to conventional treatments to disinfect wastewater for reuse. The influence of some operational parameters such as reagent dosage, catalyst concentration, initial pH, or flow rate was also studied and optimized. After several tests, the scarce pure photoactivity under UV-A was remarked by ilmenite because of its high iron content, which favors photogenerated charge recombination. However, ilmenite activity was highly promoted when combined with low concentrations of PMS and UV-A light, reaching total inactivation of Enterococcus faecalis in 120 min. Quenching tests were performed using methanol, tert-butyl alcohol, furfuryl alcohol, and Cu(II) to assess the main reactive species involved in the disinfection process determining the critical role of both HO·and SO4·- radicals in the process. Finally, the influence of the water matrix was also evaluated by studying the effect of water hardness and the presence of nutrients on the system. Overall, the PMS/Ilmenite/UV-A system yielded promising results with a total removal of Enterococcus faecalis in 120 min. However, it also showed the need for further study and understanding of the disinfection mechanism to achieve the same level of performance in real wastewaterThe "Comunidad de Madrid" supported this research through REMTAVARES S2013/MAE-2716 and S2018/EMT-434

    Energy-water-food nexus in the Spanish greenhouse tomato production

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    The nexus energy–water–food of the tomato greenhouse production in the Almeria region (Spain) has been studied following a Process Systems Analysis Method connecting the ecosystem services to the market demands with a holistic view based on Life Cycle Assessment. The management of the agri-food subsystem, the industrial subsystem and the urban subsystem plays an important role in the nexus of the E–W–F system, where transport and information technologies connect the three subsystems to the global markets. The local case study of the tomato production in Almeria (Spain) has been developed as an example of the food production under cropland restrictions, semiarid land. After study of the economic and social sustainability in time, the evolution of the ecosystem services supply is the main restriction of the system, where after the land use change in the region, water and energy supply play the mean role with a trade-off between the water quality degradation and the economic cost of the energy for water desalination. Water footprint, Carbon footprint and Chemicals footprint are useful indicators to the environmental sustainability assessment of local alternatives in the E–W–F system under study. As it is shown in the conclusions, the holistic view based on the process analysis method and the life cycle assessment methodology and indicators is an useful tool for decision support

    Upcycling spent brewery grains through the production of carbon adsorbents: application to the removal of carbamazepine from water

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    Spent brewery grains, a by-product of the brewing process, were used as precursor of biochars and activated carbons to be applied to the removal of pharmaceuticals from water. Biochars were obtained by pyrolysis of the raw materials, while activated carbons were produced by adding a previous chemical activation step. The influence of using different precursors (from distinct fermentation processes), activating agents (potassium hydroxide, sodium hydroxide, and phosphoric acid), pyrolysis temperatures, and residence times was assessed. The adsorbents were physicochemically characterized and applied to the removal of the antiepileptic carbamazepine from water. Potassium hydroxide activation produced the materials with the most promising properties and adsorptive removals, with specific surface areas up to 1120 m2 g-1 and maximum adsorption capacities up to 190 ± 27 mg g-1 in ultrapure water. The adsorption capacity suffered a reduction of < 70% in wastewater, allowing to evaluate the impact of realistic matrices on the efficiency of the materials.publishe

    Active memory controller

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    Inability to hide main memory latency has been increasingly limiting the performance of modern processors. The problem is worse in large-scale shared memory systems, where remote memory latencies are hundreds, and soon thousands, of processor cycles. To mitigate this problem, we propose an intelligent memory and cache coherence controller (AMC) that can execute Active Memory Operations (AMOs). AMOs are select operations sent to and executed on the home memory controller of data. AMOs can eliminate a significant number of coherence messages, minimize intranode and internode memory traffic, and create opportunities for parallelism. Our implementation of AMOs is cache-coherent and requires no changes to the processor core or DRAM chips. In this paper, we present the microarchitecture design of AMC, and the programming model of AMOs. We compare AMOs\u27 performance to that of several other memory architectures on a variety of scientific and commercial benchmarks. Through simulation, we show that AMOs offer dramatic performance improvements for an important set of data-intensive operations, e.g., up to 50x faster barriers, 12x faster spinlocks, 8.5x-15x faster stream/array operations, and 3x faster database queries. We also present an analytical model that can predict the performance benefits of using AMOs with decent accuracy. The silicon cost required to support AMOs is less than 1% of the die area of a typical high performance processor, based on a standard cell implementation
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