30,163 research outputs found
Phosphate and ammonium removal from wastewaters using natural-based innovative bentonites impacting on resource recovery and circular economy
No full textThe research objective of the study is the estimation of a novel low-cost composite material f-MB (Fe-modified bentonite) as a P and N adsorbent from wastewaters. The present study aimed at examining the phosphate and ammonium removal efficiency from different types of wastewater using f-MB, by conducting bench-scale batch experiments to investigate its equilibrium characteristics and kinetics. The SEM analysis revealed that the platelets of bentonite in f-MB do not form normal bentonite sheets, but they have been restructured in a more compact formation with a great porosity. Regarding the sorption efficiencies (Qm), the maximum phosphate sorption efficiencies (Qm) calculated using the Langmuir model were 24.54, 25.09, 26.13, 24.28, and 23.21 mg/g, respectively, for a pH range of 5 to 9. In addition, the maximum NH4+-N adsorption capacities (Qm) calculated from the Langmuir model were 131.8, 145.7, 168.5, 156.7, and 159.6 mg/g, respectively, for a pH range from 5 to 9. Another important finding of this study is that f-MB can recover P from treated wastewater impacting on resource recovery and circular economy (CE). The modified clay f-MB performed the phosphate and ammonium recovery rates of 80% and 78.5%, respectively. Finally, f-MB can slowly release the largest proportion of phosphate and ammonium ions for a long time, thus extending the application of the f-MB material as a slow-release fertilizer and soil improver
Application of novel composite materials as sediment capping agents: Column experiments and modelling
No full textThe research objective of the study is the estimation of PhoslockTM as a P&N-inactivation agent in the overlying water and sediment cores under oxic and anoxic conditions from a polluted pond. PhoslockTM was compared with ferrihydrite, unmodified bentonite (N-Bentonite), natural Zeolite (N-Zeolite), Alum and commercial Z2G1TM. Under oxic conditions, the maximum sorption capacities (qm) calculated from the Langmuir model were 14.1, 12.4, 11.2, 9.1 and 3.7 mg g–1 for ferrihydrite, PhoslockTM, alum, Z2G1, and natural bentonite, respectively. However, under anoxic conditions the maximum sorption capacities followed the order: PhoslockTM > alum > Z2G1>ferrihydrite > N-bent onite. Moreover, PhoslockTM as a P-inactivation agent resulted in about ~81% and ~82% reduction of the phosphate flux from oxic and anoxic sediments respectively. Also, the effect of dissolved organic matter (DOM) on phosphate sorption capacity (PAC) of PhoslockTM and Z2G1 was studied experimentally and theoretically, simulating natural eutrophic waters. At both P-sorption agents by increasing the concentration of DOM, the sorption capacity is declined. However, it is noteworthy that in the case of PhoslockTM application the PAC is retarded, whereas in the case of Z2G1 is sharp. Furthermore, the results unveiled that PhoslockTM restrained P release from the sediments, therefore a portion of P-mobile is reduced in sediments and undergone transformation to non-reactive species. Finally, in economic terms the research outcomes of this study were verified by literature, where we reported that the concentration of 20.53 mg mobile P kg–1 can be feasibly treated for $30.53 kg–1 of PhoslockTM applied
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
C*-algebras have a quantitative version of Pełczyński's property (V)
No full textsummary:A Banach space has Pełczyński's property (V) if for every Banach space every unconditionally converging operator is weakly compact. H. Pfitzner proved that -algebras have Pełczyński's property (V). In the preprint (Krulišová, (2015)) the author explores possible quantifications of the property (V) and shows that spaces for a compact Hausdorff space enjoy a quantitative version of the property (V). In this paper we generalize this result by quantifying Pfitzner's theorem. Moreover, we prove that in dual Banach spaces a quantitative version of the property (V) implies a quantitative version of the Grothendieck property
Novel composite materials as P-adsorption agents and their potential application as fertilizers
No full textThe main objective of this study is to review the role of phosphorus in fertilizers, emphasizing in phosphate rock which is the primary source for phosphate fertilizer, with reference to harmful heavy metals as a consequence of their use. Simultaneously, this study examined the use of P-Adsorption agents as a potential application in agriculture, as the adsorbed phosphorus can be used as fertilizer or enriching soil conditioners. Therefore, it is generated a sustainable cycle taking into account a renewable resource-based Phosphorus Adsorption Agent (P-AA) leading to environmental protection and conservation of natural resources. Finally, this study highlighted new aspects that support P bioavailability of Humic-metal-P (HMP) in soils, correlating with novel materials in water purification
Illuminaçao Apologetica do retrato de Morteçor en que aparecem com mais vivas côres os erros do author do novo Methodo, e seu Apologista ...
No full textFecha sacada de la pág.2 y 159Sign.: A-V\p4\sError tipográfico de signatura : a B\b2\s llama B\b3\
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A ± 12-A High-Side Current Sensor With 25 V Input CM Range and 0.35% Gain Error From −40 °C to 85 °C
No full textThis letter presents the most accurate shunt-based high-side current sensor ever reported. It achieves a 25 V input common-mode range from a single 1.8-V supply by using a beyond-the-rails ADC. A hybrid analog/digital temperature compensation scheme is proposed to simplify the circuit implementation while maintaining the state-of-the-art accuracy. Over a ±12-A current range, the sensor exhibits 0.35% gain error from -40 °C to 85 °C with 3× better power efficiency.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A 16 MHz CMOS RC Frequency Reference With ±90 ppm Inaccuracy From -45 °C to 85 °C
No full textThis article presents a 16-MHz RC frequency reference implemented in a standard 180-nm CMOS process. It consists of a frequency-locked loop (FLL) in which the output frequency of a digitally controlled oscillator (DCO) is locked to the frequency-phase characteristic of a Wien bridge RC filter. Since it is made from on-chip resistors and capacitors, the filter's characteristic is temperature dependent. To compensate for this, the control signal of the DCO is derived by digitizing the filter's output phase and combining it with the digital output of a Wheatstone bridge temperature sensor. After a two-point trim, this digital temperature compensation scheme achieves an inaccuracy of ±90 ppm from -45 °C to 85 °C. The frequency reference draws 220 from a 1.8-V supply, with a supply sensitivity of 0.12%/V and a 320-ppb Allan Deviation floor for a 10-s stride.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A CMOS Dual- RC Frequency Reference With ±200-ppm Inaccuracy From -45 °C to 85 °C
No full textThis paper presents a 7-MHz CMOS RC frequency reference. It consists of a frequency-locked loop in which the output frequency of a digitally controlled oscillator (DCO) is locked to the combined phase shifts of two independent RC (Wien bridge) filters, each employing resistors with complementary temperature coefficients. The filters are driven by the DCO's output frequency and the resulting phase shifts are digitized by high-resolution phase-to-digital converters. Their outputs are then combined in the digital domain to realize a temperature-independent frequency error signal. This digitally assisted temperature compensation scheme achieves an inaccuracy of ±200 ppm from -45 °C to 85 °C after a two-point trim. The frequency reference draws 430 μA from a 1.8-V supply, while achieving a supply sensitivity of 0.18%/V and a 330-ppb Allan deviation floor in 3 s of measurement time.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronics(OLD)Applied Quantum Architecture
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