Analysis of broadband microwave conductivity and permittivity measurements of semiconducting materials

We perform broadband phase sensitive measurements of the reflection coefficient from 45 MHz up to 20 GHz employing a vector network analyzer with a 2.4 mm coaxial sensor which is terminated by the sample under test. While the material parameters (conductivity and permittivity) can be easily extracted from the obtained impedance data if the sample is metallic, no direct solution is possible if the material under investigation is an insulator. Focusing on doped semiconductors with largely varying conductivity, here we present a closed calibration and evaluation procedure for frequencies up to 5 GHz, based on the rigorous solution for the electromagnetic field distribution inside the sample combined with the variational principle; basically no limiting assumptions are necessary. A simple static model based on the electric current distribution proves to yield the same frequency dependence of the complex conductivity up to 1 GHz. After a critical discussion we apply the developed method to the hopping transport in Si:P at temperature down to 1 K.Comment: 9 pages, 10 figures, accepted for publication in the Journal of Applied Physic

Drones: Innovative Technology for Use in Precision Pest Management.

Arthropod pest outbreaks are unpredictable and not uniformly distributed within fields. Early outbreak detection and treatment application are inherent to effective pest management, allowing management decisions to be implemented before pests are well-established and crop losses accrue. Pest monitoring is time-consuming and may be hampered by lack of reliable or cost-effective sampling techniques. Thus, we argue that an important research challenge associated with enhanced sustainability of pest management in modern agriculture is developing and promoting improved crop monitoring procedures. Biotic stress, such as herbivory by arthropod pests, elicits physiological defense responses in plants, leading to changes in leaf reflectance. Advanced imaging technologies can detect such changes, and can, therefore, be used as noninvasive crop monitoring methods. Furthermore, novel methods of treatment precision application are required. Both sensing and actuation technologies can be mounted on equipment moving through fields (e.g., irrigation equipment), on (un)manned driving vehicles, and on small drones. In this review, we focus specifically on use of small unmanned aerial robots, or small drones, in agricultural systems. Acquired and processed canopy reflectance data obtained with sensing drones could potentially be transmitted as a digital map to guide a second type of drone, actuation drones, to deliver solutions to the identified pest hotspots, such as precision releases of natural enemies and/or precision-sprays of pesticides. We emphasize how sustainable pest management in 21st-century agriculture will depend heavily on novel technologies, and how this trend will lead to a growing need for multi-disciplinary research collaborations between agronomists, ecologists, software programmers, and engineers

Una nueva especie del género Achondrostoma Robalo, Almada, Levy & Doadrio, 2007 (Actynopterigii, Cyprinidae) del oeste de España

A new freshwater fish species, Achondrostoma salmantinum, formerly considered as one population of Iberochondrostoma lemmingii, is described on the basis of genetic and morphological characters. The new species inhabits the rivers Huebra, Águeda and Uces and tributaries in the Duero River basin in Salamanca province, western Spain. The species is distinguished from Iberochondrostoma lemmingii and from other species of the genus Achondrostoma according to morphometric, meristic and genetic characters such as a narrow caudal peduncle, long postorbital and head lengths, small number of scales (9-10/44-53/4-6), small number of gill rakers (15-22), usually 5-5 pharyngeal teeth, four diagnostic isozyme loci (IDHP-2*, IDHP-3*, MDH-B* and PEP*) and one unique allele (MDH-A*95). The distribution of I. lemmingii is currently known to be restricted to the Tajo, Guadiana, Odiel and Guadalquivir basins. This new cyprinid is considered Endangered (EN) according to IUCN Red List Categories.Se describe una nueva especie de pez de agua dulce, Achondrostoma salmantinum, anteriormente considerada como una población de Iberochondrostoma lemmingii, a partir de caracteres genéticos y morfológicos. La nueva especie vive en la cuenca del río Duero en los ríos Uces, Huebra y Águeda y sus afluentes en la provincia de Salamanca en el oeste de España. De acuerdo con los caracteres morfométricos y genéticos la especie se distingue de Iberochondrostoma lemmingii y de otras especies del género Achondrostoma por un pedúnculo caudal estrecho, larga longitud de la cabeza y de la distancia postorbital, pequeño número de escamas (9/10/44-53/4-6), pequeño número de branquispinas (15-22), frecuentemente 5-5 dientes faríngeos, cuatro loci isozimáticos diagnósticos (IDHP-2*, IDHP-3*, MDH-B* y PEP*) y un único alelo (MDH-A*95). La distribución de I. lemmingii se restringe ahora a las cuencas de los ríos Tajo, Guadiana, Odiel y Guadalquivir. Este nuevo ciprínido es considerado En Peligro (EN) de acuerdo a las categorías de la Lista Roja de la UICN

Further observations on the morphological characters of Acipenser sturio L., 1758 from the Iberian Peninsula: A comparison with North and Adriatic Sea populations

Forty-two Acipenser sturio L., 1758 from Spain and Portugal were morphologically analysed. These Iberian sturgeons were collected in the Bay of Biscay, mouths of the Mondego and Tagus, and the Douro, Guadalquivir and Ebro Rivers. Specimens captured in the North and Adriatic Seas were compared with these Iberian specimens. In addition, morphological characters of various specimens of Acipenser naccarii Bonaparte, 1836 were included in this comparative analysis. Various morphological features, as well as 39 morphometric and 12 meristic characters, were determined and compared among specimens. Principal Component Analysis (PCA), using a correlation matrix, was used to assess meristic and shape variations. This technique revealed morphological differences between A. sturio and A. naccarii, and grouped all A. sturio from the three geographical areas considered. Nonetheless, univariate analysis revealed significant differences among North Sea specimens, and both Iberian and Adriatic A. sturio. Intra-specific variation of morphological patterns in A. sturio warrants further comparative research, adding specimens from other European regions, particularly from the Gironde estuary and from the Black and Baltic Seas.Se ha estudiado la morfología de cuarenta y dos ejemplares de Acipenser sturio L., 1758 conservados en colecciones de España y Portugal. Estos esturiones ibéricos proceden del mar Cantábrico, de las desembocaduras del Mondego y del Tajo, y de los ríos Duero, Guadalquivir y Ebro. Asimismo, ejemplares de A. sturio del Mar del Norte y del Adriático fueron comparados con los de la península Ibérica. Los caracteres morfológicos de algunos ejemplares de Acipenser naccarii Bonaparte, 1836 también fueron incluidos en el análisis. Se estudiaron algunos caracteres morfológicos cualitativos, así como 39 caracteres morfométricos y 12 merísticos. Para evaluar la variación merística y de la forma utilizamos el análisis de componentes principales (ACP), a partir de una matriz de correlación. Este análisis multivariado mostró diferencias morfológicas entre los ejemplares de A. sturio y los de A. naccarii, pero no marcó diferencias apreciables entre grupos para los ejemplares de A. sturio de las tres áreas investigadas. Sin embargo, cuando aplicamos un análisis univariado, encontramos algunas diferencias significativas de los ejemplares de A. sturio del Mar del Norte frente a los ibéricos y adriáticos. Estas variaciones intraespecíficas del patrón morfológico deben ser contrastadas incluyendo muestras adicionales de otras regiones europeas, principalmente del estuario del Gironda y de los mares Báltico y Negro.Instituto Español de Oceanografí

Past and present distribution of Acipenser sturio L., 1758 on the Iberian Peninsula

The present paper reviews the ichthyological and historical literature referring to sturgeon on the Iberian Peninsula. Three different species of Acipenseridae, namely Acipenser sturio L., 1758, A. naccarii Bonaparte, 1836, and Huso huso (L., 1758), have, in the past, been recorded in the Iberian seas and rivers. However, examination of specimens housed in zoological collections has clearly proved that just one, the Atlantic sturgeon A. sturio, is native to the Iberian Peninsula. Analysis of captures and observations suggests a regression of the species in Portugal and Spain, notable from the middle of the 20th century. However, A. sturio is not technically extirpated, at least not in Spain, since it was fished in 1988 off the coast of Cantabria, and in 1992 near the mouth of the Guadalquivir. Consequently, two local populations are reported as still living on the Iberian littoral: one in the Bay of Biscay and the other in Cadiz Bay. This is not contradicted by historical and present data on the Iberian distribution and status of the sturgeon.En este trabajo se revisa la bibliografía ictiológica e histórica relativa a la presencia del esturión en la península Ibérica. En el pasado se han citado hasta tres especies distintas de Acipenseridae en los mares y ríos ibéricos: Acipenser sturio L., 1758, A. naccarii Bonaparte, 1836 y Huso huso (L., 1758). Sin embargo, el estudio de los ejemplares conservados en colecciones zoológicas ha probado que sólo una, el esturión atlántico A. sturio, es nativo de la península Ibérica. El análisis de capturas y observaciones sugiere una grave regresión de la especie en Portugal y en España, muy acentuada desde mediados del siglo XX. Todavía, A. sturio no se puede considerar técnicamente extinguido, al menos en España, ya que ejemplares aislados fueron capturados en la costa de Cantabria en 1988 y cerca de la desembocadura del Guadalquivir en 1992. Por tanto, se reconocen dos poblaciones locales supervivientes en el litoral ibérico: una en el mar Cantábrico y otra en el golfo de Cádiz. Esto no se contradice con los datos históricos y actuales de la distribución ibérica y del estado de conservación del esturión.Instituto Español de Oceanografí

Studi Eksperimental Proporsi Campuran Ferrosemen Untuk Pelat Fondasi Kedap Air

Terdapatperbedaanpadamutubetonantarabeton normal tanpazataditifdanbeton yang diberizataditif.Tujuanpenelitianiniuntukmengetahuiproporsicampuran yang baikuntukpembuatanpelatferrosemenkedap air.Pengujiandilakukandengancaraujikedap air normal dankedap air agresifterhadapbendaujisilinderdengan diameter 15 cm dantinggi 30 cm, sertaujikorositerhadapbendaujipersegidengandimensi 4 cm x 4 cm x 20 cm. Benda ujiterbagimenjaditigajeniskelompok, yaitukelompokbendaujitanpazataditif, kelompokbendaujidengantambahanzataditifpolcon, dankelompokbendaujidengantambahanzataditif tam. Hasilpenelitianmenunjukkanbahwapenambahanzataditifmampumeningkatkankuattekanbetondanmeningkatkansifatkedap air betontersebut.Padahasilujieksperimentaldenganpembandingberupabendaujisilindertanpazataditif, menghasilkanpeningkatankuattekandenganpenambahanzataditifpolconsebesar 10,06% danuntukbendaujisilinderdenganpenambahanzataditif tam sebesar 13,50%. Besarresapan air padabetontanpazataditifadalah 3,61%, sedangkanbetondenganpenambahanzataditifpolconsebesar 3,74%, danbetondenganpenambahanzataditif tam sebesar 3,31%. Seluruhbendaujisilinderbetonmemenuhisyaratbataspengukurankedap air normal yaituresapansebesarkurangdari 6,5%. Dalamnyapenetrasi air padabetontanpazataditifberkisar 1,0 – 3,5 cm sehinggatergolongkedap air agresifsedang. Sedangkandalamnyapenetrasi air padabetondenganpenambahanzataditifpolconberkisar 1,0 – 2,5 cm danbetondenganpenambahanzataditif tam berkisar 0,5 – 2,0 cm sehinggatergolongagresifkuat. Padapengujiankorosi, seluruhkelompokbendaujimampumemproteksitulangansehinggatulangantidakmengalamikorosidenganempatjenisperlakuan, yaitubendaujitidakdirendam, direndamkedalam air tawar, direndamkedalam air asin, dandirendamkedalam air gambutselama 4 bulan. Sehinggasecarakeseluruhan, ketigajeniskelompokbendaujiiniterbuktimemilikisifatkedap air. Kata

Prediction of destructive properties using descriptive analysis of nd measurements

Three groups of measurements related to peach maturity were acquired through destructive (D) mechanical tests (Magness Taylor Firmness, MTF), mechanical non destructive (ND) tests, and ND optical spectroscopy (Optical indexes). The relationship between these groups of variables was studied in order to estimate D mechanical measurements (MTF, with higher instrumental and sampling variability, time consuming, generally used as a reference for the assessment of peach handling), from ND measurements (quick, applicable on line, dealing better with the high variability found in fruit products). Multivariate exploratory analysis was used to extract the structure of the data. The information about the data structure of ND measurements, the relationship of MTF with the space defined by ND variables, and the expert knowledge regarding to the dataset was then used for modelling MTF (R 2 =0.72 and standard error on validation 5.73 N

Reconciling threshold and subthreshold expansions for pion-nucleon scattering

Heavy-baryon chiral perturbation theory (ChPT) at one loop fails in relating the pion-nucleon amplitude in the physical region and for subthreshold kinematics due to loop effects enhanced by large low-energy constants. Studying the chiral convergence of threshold and subthreshold parameters up to fourth order in the small-scale expansion, we address the question to what extent this tension can be mitigated by including the $\Delta(1232)$ as an explicit degree of freedom and/or using a covariant formulation of baryon ChPT. We find that the inclusion of the $\Delta$ indeed reduces the low-energy constants to more natural values and thereby improves consistency between threshold and subthreshold kinematics. In addition, even in the $\Delta$-less theory the resummation of $1/m_N$ corrections in the covariant scheme improves the results markedly over the heavy-baryon formulation, in line with previous observations in the single-baryon sector of ChPT that so far have evaded a profound theoretical explanation.Comment: 10 pages, 4 tables, Mathematica notebook with the analytic expressions for threshold and subthreshold parameters included as supplementary material; journal versio

Acipenser sturio L., 1758 conservation resources on the World Wide Web

This paper presents a comprehensive review of the information currently available on the World Wide Web regarding Acipenser sturio L., 1758, featuring 113 selected sites concerning its conservation, biology, and related subjects. Web sites with additional information on other sturgeon species' conservation are also included. A Web page of links to the main sources of news on A. sturio and the conservation of other sturgeons can be accessed at http://www.ucm.es/ info/zoo/Vertebrados/elvira.htm.Este trabajo comprende un análisis detenido de la información disponible sobre conservación y otros temas relacionados de Acipenser sturio L., 1758 localizada en la World Wide Web. Se seleccionaron 113 páginas con información relevante sobre la biología y conservación del esturión atlántico. Asimismo, se incluyen las direcciones Web con información complementaria sobre conservación de esturiones. Una página Web que contacta con las principales fuentes de noticias sobre conservación de A. sturio y otros esturiones se encuentra disponible en http://www.ucm.es/info/zoo/Vertebrados/elvira.htm.Instituto Español de Oceanografí