Flexible CMOS low-noise amplifiers for beyond-3G wireless hand-held devices

This paper explores the use of reconfigurable Low-Noise Amplifiers (LNAs) for the implementation of CMOS Radio Frequency (RF) front-ends in the next generation of multi-standard wireless transceivers. Main circuit strategies reported so far for multi-standard LNAs are reviewed and a novel flexible LNA intended for Beyond-3G RF hand-held terminals is presented. The proposed LNA circuit consists of a two-stage topology that combines inductive-source degeneration with PMOS-varactor based tuning network and a programmable load to adapt its performance to different standard specifications without penalizing the circuit noise and with a reduced number of inductors as compared to previous reported reconfigurable LNAs. The circuit has been designed in a 90-nm CMOS technology to cope with the requirements of the GSM, WCDMA, Bluetooth and WLAN (IEEE 802.11b-g) standards. Simulation results, including technology and packaging parasitics, demonstrate correct operation of the circuit for all the standards under study, featuring NF13.3dB and IIP3>10.9dBm, over a 1.85GHz-2.4GHz band, with an adaptive power consumption between 17mW and 22mW from a 1-V supply voltage. Preliminary experimental measurements are included, showing a correct reconfiguration operation within the operation band

Total organic carbon, total nitrogen and chemical characteristics of an haplic cambisol after biochar incorporation

Biochar has been used as a soil conditioner to increase the soil organic carbon content and to improve the soil chemical characteristics. However, the effect of biochar on soil is still not clear and the soil type and biochar composition should also play an important role. In this context, the main objective of this work was to evaluate the effect of biochar application on the organic carbon (C) content and on chemical characteristics of subtropical Cambisol. The field experiment was located at the State University of Centro ‐ Oeste in Irati, Brazil, and the soil was classified as an Haplic Cambisol (Embrapa, 1999). The applied biochar was composed mainly by fine residues ( 70% < 2mm ) of an eucalyptus biochar that was a waste of the local steel industry. In February 2010, four increasing doses of biochar were applied to the soil (T1 ‐ 0 t ha ‐ 1 ; T2 ‐ 10 t ha ‐ 1 ; T3 ‐ 20 t ha ‐ 1 and T4 ‐ 40 t ha ‐ 1 ) with four replicates. Soil samples were composed by three subsamples collected within each plot. Biochar was applied on the soil surface and thereafter it was incorporated into a 0 ‐ 10 cm soil depth with an harrow. Soil samples were collected in September 2011 at four soil depths: 0 ‐ 5; 5 ‐ 10; 10 ‐ 20 and 20 ‐ 30 cm. The samples were air dried and passed through a 2 mm sieve. Soil C and nitrogen (N) contents were determined by dry combustion and the soil characteristics assessed were: pH in water, available P, exchangeable K, Ca, Mg and Al, potential acidity (H + Al), cation exchange capacity (CEC), effective cation exchange capacity (ECEC) and base saturation (V%) (Tedesco et al., 1995). The mean values were compared using SAS software (Tukey 10%). The main alterations in soil characteristics were observed in the superficial depth (0 ‐ 5 cm) (Table 1) probably due to the permanence of the biochar fine particles at the soil surface. In this layer, the application of 40 t ha ‐ 1 of biochar (treatment T4) increased in 15.5 g kg ‐ 1 the C content in comparison to treatment T1. The treatments T2 and T3 also increased the C content, but the differences were not significant. N content was not affected by biochar application. The highest dose of biochar (treatment T4) promoted an increase of the C/N ratio from 12 to 16 at the 0 ‐ 5 cm depth. Treatment T4 also increased the soil pH value in comparison to treatment T1. In addition, the contents of available P, exchangeable K and Ca where higher under treatment T4 in comparison to treatment T1 (Table 1). In opposition, exchangeable Mg content, Al+H, V% and CEC were not altered by any treatment, but T4 increased the ECEC in 3.1 cmol c dm ‐ 3 in comparison to T1. The results observed are probably due the high C and ash (26,5%) contents of biochar. A contribution of the functional groups on the surface of the biochar to the ECEC should not be excluded (Sparkes & Stoutjesdijk, 2011). Our results indicate that after two years of biochar application an increase of soil organic carbon and a positive impact on the soil chemical characteristics at the soil surface were attained, but only with the highest tested dose (40 t ha ‐ 1 ) .Peer reviewe

Effect of biochar amendment on morphology, productivity and water relations of sunflower plants under non-irrigation conditions

páginas.-- 6 figuras.-- 2 tablas.-- 56 referencias.-- Supplementary data to this article can be found online at http://dx.doi.org/10.1016/j.catena.2016.07.037.Three biochars (B1: pine wood, B2: paper-sludge, B3: sewage-sludge) produced under controlled pyrolysis conditions and one produced in kilns (B4: grapevine wood) were used as organic ameliorants in a Calcic Cambisol, which represents a typical agricultural soil of the Mediterranean region. This field study was performed with plants of sunflower (Helianthus annuus L.) at the experimental station “La Hampa”, located in the Guadalquivir river valley (SW Spain). The soil was amended with doses equivalent to 1.5 and 15 t ha− 1 of the four biochars in two independent plantations. In addition, un-amended plots were prepared in both experiments for comparison purposes. The major goal of this study was the assessment of the effect of biochar amendment on the physiology and development of sunflower plants at field conditions. During most of the growing period plants of un-amended and amended plots showed no stress symptoms either by their appearance or by stress-sensitive biochemical parameters such as the stability of the photosystem II (QY). Biochar addition had no effect on seed germination. Addition of 1.5 t ha− 1 biochar did not significantly change the pH of the soil, its electrical conductivity (EC) or its water holding capacity (WHC). Concomitantly the plant development and plant biomass production remained unaltered. Amendments with 15 t ha− 1 slightly increased the WHC of the soil but showed no lasting impact on the soil pH. It stimulated plant growth and led to a greater leaf area, larger plant stems and wider inflorescences of the sunflower plants than those cultivated on the un-amended soil. At the end of the experiment, biochar amendment of soil caused no significant increase of the total biomass production excepting B4, the biochar with the lowest capacity of water retention, which exhibited the highest vegetative growth and seed production. The lack of rain during the last weeks caused a water shortage in the culture that produced greater QY loss in non-amended plants. Interestingly, better growth of amended plants during the drought period correlated with higher reduction of stomatal conductance, indicating that the greater water use efficiency is at the origin of the better crop performance of biochar-amended plants. This finding points to the agronomic relevance of biochar amendment of Mediterranean rain fed crops.The Marie Skłodowska-Curie actions of the European Union's FP7 People Programme (REA grant agreement no PCIG12-GA-2012-333784-Biocharisma project) and the Spanish Ministry of Economy and Competitiveness (MINECO) (project PCGL2012-37041) are thanked for the financial support of the present study. The Spanish Ministry of Education, Culture and Sport is acknowledged for funding the FPU fellowship (FPU 13/05831) of Marina Paneque, and the contract of Juan De Dios Franco-Navarro (AGL2009-08339/AGR). The European Biochar Network (Biochar as option for sustainable resource management-COST action TD1107) and Bodegas Torres (Spain) are acknowledged for providing the biochar samples. M. Velasco is gratefully acknowledged for her technical assistance at field.Peer reviewe

Evaluación de la alteración de biochars utilizados como enmienda de un cultivo de girasol bajo condiciones de clima mediterráneo

5 páginas.-- 1 figura.-- 3 tablas.-- 8 referenciasEl biochar es un subproducto de la pirólisis de biomasa, generalmente posee un elevado contenido en carbono y una alta porosidad. El biochar puede mejorar las propiedades físicas y químicas del suelo, y por tanto incrementar la calidad agronómica del mismo. Además se considera una estrategia eficaz para mitigar la emisión de dióxido de carbono a la atmósfera, ya que es rico en carbono recalcitrante funcionando como sumidero de carbono. Diversos factores como el tipo de materia prima, así como las condiciones de pirólisis determinarán la composición, estructura y propiedades de los biochars, lo queocasiona una gran heterogeneidad de los productos. Aún no se conoce suficientemente como afecta la degradación al biochar en condiciones de campo. Es necesario conocer cómo se modifica la composición de esta materia orgánica pirogénica una vez es incorporada al suelo, con este objetivo principal se sometió a cinco tipos diferentes de biochars a un envejecimiento en condiciones de clima Mediterráneo. Para ello, se mezclaron las muestras de biochar con un cambisol de la finca experimental “La Hampa” a modo de enmienda. Posteriormente se sembraron plantas de girasol, que fueron cosechadas a los 6 meses de su germinación. A los 6, 12 y 24 meses de iniciado el experimento se tomaron muestras de suelo y de biochar para su estudio. Con el fin de poder conocer las alteraciones en la composición y propiedades del biochar, se han realizado análisis de C y N, de pH, conductividad eléctrica y la determinación de la fragmentación. Además, el uso de la Resonancia Magnética Nuclear de 13C en estado sólido nos permitió observar los cambios en la funcionalidad de este material.M. Paneque agradece al Ministerio de Educación de España la financiación de la beca FPU 13/05831. Se agradece al MINECO la financiación del proyecto BIOREMEC (CGL2016-76498-R).N

Cambios temporales en el origen de la materia orgánica en las marismas del Río Miño (NW Península Ibérica) mediante marcadores lipídicos. Temporal changes in the organic matter sources in the Minho River tidal marshes (NW Iberian Península): A lipid biomarker approach.

[EN]: The lipid biomarker distribution in a sediment core fromMinho river tidal-marshes (NW Iberian Peninsula) was studiedusing gas chromatography-mass spectrometry (GC/MS) in order to evaluate changes in the sources and distribution of organic matter (OM) in the estuary during the last centuries. The distribution of terrestrial and phytoplankton biomarker inventory reflected an heterogeneous mixture of OM from marine and terrestrial sources. Lignin derived phenols, triterpenoids and long chain n-alkanes with an odd number of carbons are indicators of soil-and vascular plant-derived continental OM, being more abundant on the topmost sections of the core. In addition, a conspicuous contribution from plankton-derived OM (e.g. short chain fatty acids and alcohols, phytosterols) is observed in the deepest sections of the core. However, in general the lipid biomarker assemblage found indicate the existence of a complex input of organic matter (OM) to this estuarine area, from both river run-off and marine depositions. Temporal variations observed could also be attributed to terrigenous contributions after flooding events from Miño river, although a differential degradation of individual biomarkers should not be neglected when interpreting biomarker assemblages in this geodynamically active environment. [ES]: Con el objetivo de evaluar las variaciones en las fuentes y distribución de la matería orgânica (MO) durante los últimos siglos, se estudia la distribución de biomarcadores lipídicos en una secuencia sedimentaria de las marismas del río Miño (NW Península Ibérica) mediante Cromatografía de Gases¿Espectrometria de Masas (CG/MS) . La distribución de biomarcadores terrestres y marinos muestra una mezcla heterogénea de MO con diferente orígen. Los fenoles derivados de la lignina, triterpenoides y n-alcanos de cadena larga con número impar de carbonos proceden de plantas superiores, indicadores de MO de origen continental , se encuentran com mayor abundancia en las secciones superiores del sondeo. Los lípidos derivados del plancton marino (ej., acidos grasos y alcoholes de cadena corta, fitosteroles) se encontraron con mayor abundancia relativa en las secciones mas profundas del sondeo. Sin embargo, la distribución global de los biomarcadores lipídicos estudiados muestra la complejidad de las fuentes de MO en este estuario, y que incluye las descargas del río y deposiciones de sedimentos marinos. Algunas variaciones observadas pueden deberse a contribuciones de MO terrígena debidas a descargas elevadas procedentes del río Miño. No obstante, a la hora de interpretar los cámbios observados en la distribución de determinados biomarcadores en este ambiente geodinámicamente activo, se debe tener en cuenta la posible ocurrencia de fenómenos de degradación preferencial o selectiva en el sedimento.Peer Reviewe

Determination of refractory organic matter in marine sediments by chemical oxidation, analytical pyrolysis and solid-state 13C nuclear magnetic resonance spectroscopy

Seeking to quantify the amount of refractory organic matter (ROM), which includes black carbon-like material (BC), in marine sediments, we have applied a two-step procedure that consists of a chemical oxidation with sodium chlorite of the demineralized sediments followed by integration of the aromatic C region in the remaining residues by solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. The efficacy for lignin removal was tested by analytical pyrolysis in the presence of tetramethyl ammonium hydroxide (TMAH). Riverine, estuarine and offshore marine sediment samples were collected from the southwest Atlantic coast of Spain, a site of geological and environmental interest. Measured contents of BC-like material ranged between 3.0 and 45.7% of the total organic carbon. Greater relative BC contents were found in riverine sediments close to urban areas, which show an elevated input of anthropogenic organic material. The contents of BC-like material in offshore marine sediments (5.5–6.1%) were similar to those previously reported for these kinds of samples. However, NMR and pyrolysis-GC/MS of the isolated ROM reveals that abundant refractory aliphatic organic material remains in most of the marine samples after chlorite oxidation. We suggest that this pool of aliphatic carbon may play an important role as a stable carbon pool within the global C cycle.The Spanish Ministry of Education provided financial support for this research (fellowship BES-2003-1900 and project CGL2006-12730-C03-C01).9 páginas, 3 figuras, 6 tablas, 38 referencias.-- [email protected] reviewe

Direct specific isotopic analysis of compounds released by pyrolysis (Py-CSIA): Novel applications in paleoenvironmental studies

Poster J.03 presentado en el The 40th International Symposium on Capillary Chromatography and 13th GCxGC Symposium May 29-June 03, (2016) Riva del Garda Fierecongressi, Riva del Garda, Italyisotopic analysis (Py-CSIA) and analytical pyrolysis (Py-GC/MS) opens new windows of information and is particularly useful to study solid materials that are not soluble and therefore not amenable by conventional GC/MS techniques. Py-CSIA is a rather novel hyphenated technique that combines the chromatographic separation of compounds released by pyrolysis (Py-GC) with an isotope ratio mass spectrometer (IRMS). The technique allows the measurement of stable isotope proportions i.e., δ13C, δ15N and δ2H, δ18O in specific compounds released by pyrolysis. The sample preparation is minimized and a molecular fingerprinting of the material is achieved.N

Factors involved in soil organic matter stabilization in Peruvian Amazonian soils (Ucayali region) and the molecular composition of extractable lipids

Poster E1012b presentado en el 27th International Meeting on Organic Geochemistry September 13–18, 2015, Prague, Czech RepublicAmazonian ecosystems are considered important sinks for atmospheric CO2 on Earth. It is therefore desirable to preserve their biodiversity and productivity. In this communication an assessment of the influence of different agro-forestry practices on soil C storage in representative ecosystems from the Peruvian Ucayali region is approached by analyzing the soil lipid fraction. In fact, this organic matter fraction is an important source of analytical surrogates of soil C stabilization and accumulation processes (Naafs at al., 2004; Poulenard et al., 2004; Rumpel et al., 2004). Top (0–20 cm) and subsoil (20–40 cm) samples were taken from the Amazonian Ucayali region (Pucallpa, Perú), ranging from recent alluvial soils in muddy zones of riverside areas (wetlands referred to as ‘mud’, ‘beach’ and low ‘restinga’ soils) to more developed soils located in medium and higher riverine terraces, as well as in hills. The lipid fraction was Soxhlet extracted with a mixture of ichloromethane:methanol (2:1 by vol.), saponified and divided into neutral and acid subfractions. The acid fractions were then sequentially methylated and silylated prior to the chromatographic analysis (González-Vila et al., 2003). Neutral and acid sub-fractions were separated and the major compounds were identified by gas chromatography-mass spectrometry using an HP G1800A GCD System (electron impact detector at 70 eV) equipped with a DB-5 fused silica capillary column (30 m × 0.32 mm i.d., film thickness 0.25 µm) and using He as carrier gas at a flow rate of 1.5 mL min-1. The chromatographic oven temperature was programmed to increase from 40 to 100 ºC at 30 ºC min-1 and then to 300 ºC at 6 ºC min -1. The values of soil organic matter and lipids ranged from 25.8 to 5.8 g kg-1, and from 5.2 to 0.2 g kg-1, respectively. This variability as well as the differences in lipid molecular composition could suggest differences in the soils’ use and management practices (Van Bergen et al.,1996). The main families of signature lipids detected in the soil extracts were n-alkanes, linear isoprenoids, cyclic alkanes, n-fatty acids, branched fatty acids, unsaturated fatty acids, hydroxyacids, n-alcohols, ketones, polycyclic hydrocarbons and sterols. Very significant differences in qualitative and quantitative lipid composition were found in terms of soil depth. This effect was more pronounced in the soils from the riverine high terraces devoted to agro-forestry practices (Figs. 1 and 2). In addition, lipidic compounds of high molecular weight (i.e., di- and triterpenes) were detected as regular components of the free lipid fractions from the different ecosystems (wetlands, terraces and hills) reflecting specific vegetation and soil-use influences. Xenobiotic compounds (naphthenic acids) detected within the unresolved chromatographic ‘hump’ (highly unresolved mixture of cyclic or branched hydrocarbons) were also observed, indicating anthropogenic contamination by mineral oils. Likewise, dialkyl phthalates (Phth) from plasticizers were also detected.Projects CGL2012-38655-C04-01 and CGL2008-04296 and fellowship BES-2013-062573 given to N.T.J.M by the Spanish Ministry of Economy and Competitiveness. Dr. J.M.R. is the recipient of a fellowship from the JAE-Doc subprogram financed by the CSIC and the European Social Fund.Peer Reviewe

Contents

Póser presentado en el 17th International Conference on Chemistry and the Environment (ICCE 2019) 16th and 20th of June, 2019 Thessaloniki (Greece).- Puede descargar el programa completo en https://icce2019.org/content/ICCE-2019-Conference-Programme.pdfBiochar is the solid material rich in aromatic carbon produced through the pyrolysis (heating under limited oxygen conditions) of residual biomass (De la Rosa et al., 2014). Paz-Ferreiro et al. (2014) showed that biochars can reduce the bioavailability and leachability of heavy metals in contaminated soils. Trace elemen t polluted soils is a worldwide concern covering 37% of the degraded soils in the European Union (EEA, 2007). The aim of this study is to produce a biochar from agricultural residues efficient in the restoration of soils contaminated with trace elements. In this study, the influence of biochar on soil enzymatic activity and plant germination were studied in two Typic Xerofluvent soils polluted with trace elements, which were sampled in an area affected by the breaching of a tailing dam occurred in 1998 (Aznalcóllar mine accident; SW Spain) with two respective levels of contamination (MPS; moderately polluted soil and HPS; highly polluted soil). Biochars used in this study were produced from four different biomasses: rice husk, pruned olive trees, olive pits and “alperujo” (a byproduct of the olive oil). The feedstock was pyrolysed in a 0.64L steel reactor under N2 atmosphere. Pyrolysis temperature and reaction time were controlled, thus biochars were produced with temperatures ranging between 400 and 500 ºC whereas reaction time ranged from 1 to 4h. Each soil was mixed with 0, 2, 5 and 10% of biochar, and the pots were made in triplicate. All the pots were incubated under controlled conditions (60% of water holding capacity; 25 ºC) during 65 days and sown (Brassica rapa spp. Pekinensis). The plant experiment also lasted 65 days. The following parameters were determined for this study: bioavailability of trace elements (As, Cd, Cu, Fe, Ni, Pb, Sr and Zn), germination rates, plant biomass, partitioning of trace elements into Brassica leaves (Ba, Cd, Cu, Fe, Ni, Pb, Sr and Zn), pH, dehydrogenase (DHA) and β-glucosidase (BGA) activities in biochar amended and un-amended soils. Changes in bioavailability of trace elements in soils were influenced by incubation conditions, not by biochar application. Soil pH increased with the dose of biochar. DHA showed 10 times greater activity in MPS than HPS. Furthermore, biochar amended MPS showed greater DHA than control soils. BGA decreased with increasing biochar rate application. No significant differences were observed in the germination rates in MPS, whereas germination increased with biochar dose for HPS.References De la Rosa, J.M., Paneque, M., Miller, A.Z. & Knicker, H. (2014). Relating physical and chemical properties of four different biochars and their application rate to biomass production of Lolium perenne on a Calcic Cambisol during a pot experiment of 79 days. Science of the Total Environment, 499, 175-184. EEA. (2007). Progress in Management of Contaminated Sites. CSI 015. Copenhagen, Denmark: European Environmental Agency. Paz-Ferreiro, J., Lu, H., Fu, S., Méndez, A. & Gascó, G. (2014). Use of phytoremediation and biochar to remediate heavy metal polluted soils: a review. Solid Earth, 5, 65-75.The Spanish Ministry of Economy, Industry and Competitiveness (MINEICO) and AEI/FEDER are thanked for funding the project CGL2016-76498-R. P. Campos thanks the “Fundación Tatiana Pérez de Guzmán el Bueno” for funding her PhD.Peer reviewe