Polarimetric Response of Rice Fields at C-Band: Analysis and Phenology Retrieval

A set of ten RADARSAT-2 images acquired in fully polarimetric mode over a test site with rice fields in Seville, Spain, has been analyzed to extract the main features of the C-band radar backscatter as a function of rice phenology. After observing the evolutions versus phenology of different polarimetric observables and explaining their behavior in terms of scattering mechanisms present in the scene, a simple retrieval approach has been proposed. This algorithm is based on three polarimetric observables and provides estimates from a set of four relevant intervals of phenological stages. The validation against ground data, carried out at parcel level for a set of six stands and up to nine dates per stand, provides a 96% rate of coincidence. Moreover, an equivalent compact-pol retrieval algorithm has been also proposed and validated, providing the same performance at parcel level. In all cases, the inversion is carried out by exploiting a single satellite acquisition, without any other auxiliary information.

Estimation of Key Dates and Stages in Rice Crops Using Dual-Polarization SAR Time Series and a Particle Filtering Approach

Information of crop phenology is essential for evaluating crop productivity. In a previous work, we determined phenological stages with remote sensing data using a dynamic system framework and an extended Kalman filter (EKF) approach. In this paper, we demonstrate that the particle filter is a more reliable method to infer any phenological stage compared to the EKF. The improvements achieved with this approach are discussed. In addition, this methodology enables the estimation of key cultivation dates, thus providing a practical product for many applications. The dates of some important stages, as the sowing date and the day when the crop reaches the panicle initiation stage, have been chosen to show the potential of this technique.

Using Sewage-Sludge Ash as Filler in Bituminous Mixes

In this study, the behavior of bituminous mixes made with sewage sludge ash (SSA) as mineral filler was investigated. The behavior of these mixes was evaluated with the Cantabro, indirect tensile strength, water sensitivity, permanent deformation, and resilient modulus tests. The results show that SSA waste may be used in bituminous mixes at approximately 2–3% weight percent, maintaining adequate levels of cohesion and adhesion in the mixtures, which is comparable to mixtures made with active fillers such as hydrated lime and cement. Moreover, its use does not increase permanent deformations. However, the resilient modulus test gave slightly lower results for mixes made with SSA than for mixtures made with other fillers. It may be concluded that SSA waste may be used as a filler for bituminous mixes with better results than for mixes made with limestone fillers and with similar results for mixes made with other fillers such as hydrated lime and cement.

Influence of Incidence Angle on the Coherent Copolar Polarimetric Response of Rice at X-Band

The coherent nature of the acquisition by TerraSAR-X of both copolar channels (HH and VV) enables the generation of many different polarimetric observables with physical interpretation, as have recently been used for monitoring rice fields. In this letter, the influence of incidence angle upon these polarimetric observables is analyzed by comparing three stacks of images that were acquired simultaneously at different incidence angles (22°, 30°, and 40°) during a whole cultivation campaign. We show that the response of observables related to dominance (entropy, ratios of components) and type of scattering mechanisms (alpha angles) is not greatly influenced by incidence angle at some stages: early and advanced vegetative phases, and maturation. Moreover, the acquisition geometry drives the sensitivity to the presence of the initial stems and tillers, being detected earlier at shallower angles. This analysis is a necessary step before studying potential methodologies for combining different orbits and beams for reducing the time between acquisitions for monitoring purposes.

Semivolatile and Volatile Compound Evolution during Pyrolysis and Combustion of Colombian Coffee Husk

Thermal characterization of coffee husk (Coffea arabica) from Colombian coffee has been studied. Different products, mostly volatile and semivolatile compounds, were analyzed, paying special attention to 16 polycyclic aromatic hydrocarbons (PAHs) classified by the United States Environmental Protection Agency (U.S. EPA) as priority pollutants, frequently used for checking toxicity in environmental samples. A fixed amount of raw material was exposed to different excess air ratios (λ = 0–2.33) and nominal temperature of 1123 K in a horizontal quartz reactor. The results show that coffee husk is a promising biomass for energetic exploitation with reduced formation of PAHs in a low air excess ratio. This implies reduction of carcinogenic potential in the limited presence of oxygen, demonstrated by calculating the carcinogenic potential (KE) for each experimental condition. Most volatile and semivolatile compounds followed different trends, with the oxygen presence prevailing their decomposition with increasing the air excess ratio.

Payment order for Samuel Adams on behalf of John Rice, 1772 July 1

Handwritten order to John Sale to pay scholarship funds to Samuel Adams for use by student John Rice (Harvard AB 1774), signed by Charles Chauncey, Thomas Waite, Jonathan Williams, and Daniel Marsh.

Hādhā kitāb al-Simṭ al-ʻabqarī fī sharḥ al-ʻIqd al-jawharī fī al-farq bayna kasbay al-Māturidī wa-al-Ashʻarī

al-matn min muṣannafāt al-Shaykh Khālid Ḍiyāʼ al-Dīn ; wa-al-sharḥ min muʼallafāt al-muḥaqqiq al-almaʻī wa-al-mudaqqiq al-lawzaʻī ʻAbd al-Ḥamīd Ḥamdī Afandī al-Kharpūtī, al-shahīr bi-Ibn shāriḥ al-Burdah.

Hādhihi Ṭabaqāt al-ʻallāmah al-Shaykh Aḥmad al-Shurnūbī yadhkuru fīhā manāqib al-awliyāʼ al-arbaʻah wa-karāmāt aṣḥāb al-ashāyir al-arbaʻ

[Muḥammad al-Bulqīnī].

Kitāb-i ashʻār-i malik al-shuʻārāʼ Amīr Muʻizzī : manuscript, 1156

Title from f. 1r.

Taẕkirah-ʼi ashʻār-i zanān-i vilāyat-i Īrān va-ghayruhu musammá ba-Javāhir al-ʻajāyib : manuscript, 1849

Unbound.