Geometry, kinematics and rates of deformation in a normal fault segment boundary, central Greece

The geometry, kinematics and rates of deformation within a fault segment boundary between the ends of two major active normal fault segments have been investigated through examination of a faulted 126 ka marine terrace. Slip‐vector azimuths defined by striations on the faults indicate N‐S extension on c. E‐W faults, sub‐parallel to those from earthquake focal mechanisms, together with significant and contemporaneous E‐W extension on c. N‐S faults. Summed rates of E‐W extension along a c. 550 m transect (0.17 mm/yr) are comparable with those for N‐S extension (0.20 mm/yr) along a c. 350 m transect. Our observations show that distributed non‐plane strain extension occurs in fault segment boundaries and this should be noted when studying fault‐tip fracture toughness and regional deformation rates

Improving the Efficiency of Rice Drying: Impact of Operational Variables on the Drying Rate and Quality of a South American Variety

A key challenge for the rice industry during harvest is to improve the efficiency of the drying process, which involves increasing the drying rate and the head rice yield (HRY). In the present chapter, the main variables affecting the efficiency of rice drying were discussed. Then, the impact of the drying air conditions on the drying efficiency of a long-grain South American rice variety at different rice moisture contents (MC) was studied using a thin-layer lab-scale dryer. Drying at each air condition was modeled using Page’s equation. The drying rate increased as the air conditions became more extreme (higher temperature or lower relative humidity). The effect on the HRY depended on the rice MC. Therefore, a two-stage drying program was proposed using different drying air temperatures depending on rice MC. These results were applied to create a drying program for a long-grain South American variety dried in a cross-flow commercial dryer. The two programs tested increased the drying rate and one of them also increased the HRY, compared to drying at the industry operational conditions. Implementing this program would improve the efficiency of the drying process, increasing the reception capacity and the profitability of the rice obtained

Almacenamiento de arroz: influencia en la inocuidad del grano = Rice storage: effects on grain safety

La producción de arroz (Oryza sativa) ocupa el quinto lugar en las exportaciones agrícolas de Uruguay. Inadecuadas condiciones de temperatura y humedad favorecen el desarrollo de hongos e insectos impactando en la inocuidad del arroz almacenado. El objetivo de este trabajo fue evaluar la sanidad del arroz cáscara en condiciones de almacenamiento en silos comerciales durante dos zafras. Se utilizó la variedad de grano largo “El Paso 144” durante 8,5 y 7 meses en los años 2017 y 2018, respectivamente. Se detectaron e identificaron agentes de biodeterioro; se determinó capacidad germinativa, recuento microbiano y contenido de toxinas en arroz extraído de las zonas superior e inferior del silo, a distintos tiempos de almacenamiento. La población microbiana disminuyó en ambos años y posiciones dentro del silo. Se identificaron principalmente dos géneros micotoxigénicos, Fusarium sp. y Aspergillus sp. En relación con micotoxinas no se detectó Zearalenona ni Ocratoxina A, y Deoxinivalenol se detectó en un máximo 120 ppb (zafra 2017). No se dectaron aflatoxinas B1, B2, G1 y G2. Los insectos identificados fueron Sitophilus sp. y Rhizopertha sp. con una incidencia máxima de 0,1%. Estos resultados demuestran que las condiciones de almacenamiento no afectaron la seguridad del grano

Armazenamento de arroz: influência na segurança dos grãos

Rice (Oryza sativa) production ranks fifth in Uruguay’s agricultural exports. Inadequate temperature and humidity conditions increase grain respiration and favor the action of insects and fungi. This process contributes to mass grain losses and stored rice biodeterioration. The objective of this work was to evaluate paddy rice sanitary conditions during storage in commercial silos through two years. The study was carried out using the “El Paso 144” long grain variety for 8,5 and 7 months in 2017 and 2018, respectively. Main biodeterioration agents were detected  and identifed. Germination capacity, microbial population and toxin content in rice extracted from the upper and lower areas of the silo were determined at differentstorage times. The microbial population decreased after storage time and in both silos sampling positions. Two mycotoxigenic genera, Fusarium sp and Aspergillus sp. were detected. Mycotoxins, Zearalenone and Ocratoxin-A were not detected, while Deoxinivalenol reached a maximum level of 120 ppb (2017). Aflatoxins B1, B2, G1 and G2 were not detected. The coleopteran Sitophilus sp and Rhizopertha sp. were identifed and quantifed with a maximum incidence of 0,1%. These results demonstrate that storage conditions did not affect grain safety.La producción de arroz (Oryza sativa) ocupa el quinto lugar en las exportaciones agrícolas de Uruguay. Inadecuadas condiciones de temperatura y humedad favorecen el desarrollo de hongos e insectos impactando en la inocuidad del arroz almacenado. El objetivo de este trabajo fue evaluar la sanidad del arroz cáscara en condiciones de almacenamiento en silos comerciales durante dos zafras. Se utilizó la variedad degrano largo “El Paso 144” durante 8,5 y 7 meses en los años 2017 y 2018, respectivamente. Se detectaron e identifcaron agentes de biodeterioro; se determinó capacidad germinativa, recuento microbiano y contenido de toxinas en arroz extraído de las zonas superior e inferior del silo, a distintos tiempos de almacenamiento. La población microbiana disminuyó en ambos años y posiciones dentro del silo. Se identifcaron principalmente dos géneros micotoxigénicos, Fusarium sp. y Aspergillus sp. En relación con micotoxinas no se detectó Zearalenona ni Ocratoxina A, y Deoxinivalenol se detectó en un máximo 120 ppb (zafra 2017). No se dectaron aflatoxinas B1, B2, G1 y G2. Los insectos identifcados fueron Sitophilus sp. y Rhizopertha sp. con una incidencia máxima de 0,1%. Estos resultados demuestran que las condiciones de almacenamiento no afectaron la seguridad del grano.A produção de arroz (Oryza sativa) ocupa o quinto lugar nas exportações agrícolas do Uruguai. Condições inadequadas de temperatura e umidade favorecen a ação de insetos e fungos impactando na saúde do grão. O objetivo do trabalho foi avaliar o estado sanitário de casca de arroz em condições de armazenamento em silos comerciais para duas safras. O estudo foi realizado com a variedade de grão longo “El Paso 144” por 8,5 e 7 meses em 2017 e 2018, respectivamente. Os agentes de biodeterioração foram detectados e identifcados e a capacidade de germinação, a contagem microbiana e o conteúdo de toxinas no arroz extraído das áreas superior e inferior do silo foram determinados em diferentes tempos de armazenamento.A população microbiana diminuiu nos dois anos e nas posições dentro do silo. Dois gêneros micotoxigênicos foram identifcados principalmente: Fusarium sp. e Aspergillus sp. Em relação às micotoxinas, Zearalenona e Ocratoxina-A não foram detectadas, enquanto o Deoxinivalenol foi detectado no máximo em 120 ppb (safra2017). Não foram prescritas aflatoxinas B1, B2, G1 e G2. Os insetos Sitophilus sp. e Rhizopertha sp. foram detectados com uma incidência máxima de 0,1%. Portanto, as condições de armazenamento não afetaram a segurança do grão

Efecto de la variedad y de la humedad de cosecha en la temperatura de transición vítrea de variedades uruguayas de arroz = Effect of rice variety and harvest moisture content on the glass transition temperature of Uruguayan rice varieties

La temperatura de transición vítrea (Tg) de un material es el rango de tempe-raturas donde ocurre la transición entre un estado cauchoso y un estado vítreo, produciéndose cambios que se ven reflejados en sus propiedades fisicoquímicas. El objetivo de este trabajo es determinar las curvas de transición vítrea (Tg vs. Humedad de grano) de tres variedades uruguayas de arroz y evaluar si existen di-ferencias significativas entre ellas. Se estudia también la influencia de la humedad de cosecha (HC). Para ello, cada muestra de arroz se seca por diferentes períodos de tiempo para obtener humedades de grano (HG) en un rango entre 10% y 22% (en base húmeda). A continuación, se mide la Tg por calorimetría diferencial de barrido (DSC). Los resultados se comparan aplicando ANOVA y el test de Tukey. Se observó que la Tg aumenta a medida que disminuye la HG para las tres variedades estudiadas. Las curvas de transición vítrea muestran que existen diferencias significativas entre las tres variedades en el rango de HG de 12% a 16%. La HC no afectó la Tg en todo el rango estudiado. Los resultados obtenidos pueden aplicarse para optimizar el proceso de secado del arroz, minimizando la formación de fisura

A ten years analysis of deformation in the Corinthian Gulf via GPS and SAR Interferometry

The Corinthian Gulf in Greece, is the most active of a series of extending grabens which accomodate the deformation in the highly seismic Aegean region. The geodetic network established in the region has about 200 points: 50 1st order points and ~150 2nd order points. The network covers an area of about 100 x 80 km2, which correspond to an average density of 1 point every 5 km2. This dense network allows to study the main active faults in the region. Eleven field surveys were organized in 1990, 1991, 1992, 1993, 1994, June 1995, October 1995, 1997, and 2001. Two earthquakes occurred in the vicinity during the ten years period: the 1992, 18 November Ms=5.9 Galaxidi earthquake and the 1995, 15 June 1995 Ms=6.2 Aigion one. With respect to the stable Europe, we find for Peloponnessos an average displacement rate of 30 mm/yr in the N215° direction, similar to that found in previous studies. Our results show that most of the deformation in the Corinthian Gulf is localizes off-shore, in a narrow band, in the central part of the Gulf. The extension rate measured over 10 years is 11 mm/yr in the N185° direction in the middle of the Gulf (Xiloxastro) and 16 mm/yr in the N185° direction in its western part (Aigion). The southern block appears un-deformed, except the region of Aigion event. Using CNES DIAPASON software, we derived 85 interferograms of the Corinthian Gulf from 38 raw ERS SAR images acquired between 1992 and 1999. The interferograms sampling the 1995 earthquake show a clear coseismic signal reaching 250 +/- 15 mm at Psaromita cape, a value consistent with the GPS measurements. No post-seismic motion, within the error bars of SAR interferometry (+/- 15 mm), is observed during the 1995-1999 period

Crustal strain in central Greece from repeated GPS measurements in the interval 1989-1997

A 66-station GPS network spanning central Greece, first observed in 1989, has been occupied fully on three occasions: June 1989, October 1991 and May 1993. Subsets of this network bounding the Gulf of Korinthos have also been occupied in June 1995, October 1995, May 1996 and September/October 1997. The first three occupations were processed using a fiducial GPS methodology, whereas later surveys were processed using CODE precise orbits. Combination of data from different surveys to yield smooth site velocities requires global network translations at each epoch to compensate for errors in the realization of the reference frame. This method provides a posteriori estimates of the relative coordinate errors and reference frame noise. Only one earthquake, the 1995 June 15 Egion event, has caused significant local coseismic displacement, and its effects on the interseismic velocity field are removed using an elastic dislocation model. We constrain the orientation of the 100 yr triangulation—GPS velocity estimates of Davies et al. (1997) using 14 sites common to the two networks. The goodness of fit of this transformation indicates that the short-term and 100 yr geodetic estimates of deformation are highly compatible. We infer that short-term geodetic studies are capable of determining longer-term deformation rates provided that transient, local effects can be modelled. From the combined velocity field, we estimate principal strains and rigid-body rotation rates at points on a regular grid using data from neighbouring sites. Strain rates are high within the Gulf of Korinthos and much lower elsewhere. The extension rate across the Gulf of Korinthos increases from east to west. Comparison of the extension rate with historical and recent rates of seismic release of strain reveals significant medium-term seismic hazard in the western Gulf of Korinthos, and may also indicate long-term aseismic strai

Constraints from GPS measurements on the dynamics of deformation in Anatolia and the Aegean

We estimate the strength of the lithosphere in Anatolia and the Aegean, and the boundary forces acting upon it, using a dynamical model that treats the lithosphere as a thin fluid sheet deforming in response to variations in gravitational potential energy. This model has one free material parameter, the power law exponent, n, of the vertically averaged rheology of the lithosphere, and two parameters that specify the forces per unit length applied to its edges. Solutions to this model that best fit the velocities of 346 reliable GPS sites require an effective viscosity of the lithosphere of 1022 to 1021 Pa s at strain rates of 10 to 100 nanostrain per year. The best-fitting force at the Arabia-Anatolia boundary is consistent with the lithostatic pressure due to the high topography there, and the force at the Nubia-Aegean boundary is consistent with the contrast in lithostatic pressure across that boundary. No additional force, from “slab rollback” or basal tractions due to convection in the mantle, is required to explain the observations. These results are supported by scaling relations derived from approximate analytical solutions. The inverse relationship between the viscosity of the lithosphere and deviatoric stress produces strong slowly deforming regions in the Southern Aegean and Central Anatolia whose motions resemble those of microplates. The distribution of geodetic strain rates within the region, and the partitioning between normal and strike-slip faulting, are explained by the interplay between boundary conditions, internal variations in gravitational potential energy, and the power law rheology of the lithosphere

Measuring the Energy Required to Dry Rice in Commercial Rice Dryers

The objective of this research was to quantify and assess the energy use and efficiency of commercial cross-flow dryers when drying rice using a range of drying and ambient conditions. First, equations that predict the theoretical energy required to dry rice from any given initial moisture content to a desired final moisture content were developed for several rice cultivars using a semi-theoretical approach to obtain a basis for comparison to calculate energy efficiency. Theoretical energy requirements, expressed as the energy required per unit mass of water removed, increased exponentially as initial moisture content decreased. Additionally, medium-grains required more energy to be dried than long-grains; non-parboiled rice required more energy to be dried than parboiled rice. Second, a two-year study was performed to measure energy requirements of both an on-farm, cross-flow dryer and a commercial, cross-flow dryer. In 2011 for the on-farm dryer, energy requirements ranged from 2,840 to 5,310 kJ/kg water removed and in 2012 from 3,730 to 5,840 kJ/kg water removed. Energy efficiencies, which were calculated as the ratio of theoretical energy requirements to the measured energy requirements, ranged from 47 to 90% in 2011 and from 44 to 69% in 2012. Thermal energy requirements of the commercial dryer ranged from 6,900 to 9,670 kJ/kg water removed in 2011 and from 8,800 to 9,620 in 2012. Electrical energy use, which ranged from 300 to 400 kJ/kg water removed in 2011 and from 410 to 630 in 2012. Energy efficiency ranged from 26 to 36% in 2011 and from 27 to 29% in 2012. It was found for both dryers that thermal energy requirements were linearly correlated to the difference between drying air temperature and ambient temperature and linearly and inversely correlated to the amount of water removed per mass dry matter. Equations were developed to predict energy use and efficiency as a function of these two parameters

Energy use and efficiency of rice-drying systems II. Commercial, cross-flow dryer measurements

Energy use and efficiency of a commercial, cross-flow dryer were measured when drying rough rice across a range of ambient conditions and drying air temperatures. Four tests were conducted during the 2011 harvest season using rice with initial moisture contents ranging from 19.0% to 21.7% wet basis and three tests were conducted during the 2012 harvest using rice with initial moisture contents from 15.4% to18.3%. To obtain thermal energy requirements in terms of energy per unit mass water removed, the energy consumed by the burner was divided by the total amount of water removed. In addition, electrical energy requirements were determined by multiplying the average power draw of the fan motor by the fan operating duration. Thermal energy efficiency was calculated by dividing theoretical energy requirements by the measured thermal energy requirements. Thermal energy requirements to dry rice ranged from 6,900 to 9,670 kJ/kg water removed in 2011 and from 8,810 to 9,620 in 2012. Electrical energy use, which ranged from 300 to 400 kJ/kg water removed in 2011 and from 410 to 630 in 2012, accounted for ~4% to 5% of the total energy used to dry rice. Thermal energy requirements were linearly correlated to the difference between drying air temperature and ambient temperature and linearly and inversely correlated to the amount of water removed per mass dry matter. Thermal energy efficiency ranged from 26% to 36% in 2011 and from 27% to 29% in 2012