160 research outputs found

    Factors Affecting Forage Quality of Native Species in Iranian Rangelands

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    Animal performance is closely correlated with the nutrient value of the forage available and this is affected by different factors (Arzani et al., 2001). Crude protein content (CP), digestible dry matter (DDM) and metabolisable energy (ME) were considered particularly appropriate for evaluation of range forage quality. This paper reports on factors affecting the forage quality of range species grown in Iran

    Online Optimal Neuro-Fuzzy Flux Controller for DTC Based Induction Motor Drives

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    In this paper a fast flux search controller based on the Neuro-fuzzy systems is proposed to achieve the best efficiency of a direct torque controlled induction motor at light load. In this method the reference flux value is determined through a minimization algorithm with stator current as objective function. This paper discusses and demonstrates the application of Neurofuzzy filtering to stator current estimation. Simulation and experimental results are presented to show the fast response of proposed controller

    Plankton composition and environmental parameters in the habitat of the Iranian cave barb (Iranocypris typhlops) in Iran

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    La composición planctónica y los parámetros ambientales en el hábitat del barbo cavernícola iraní Iranocypris typhlops El barbo cavernícola iraní, Iranocypris typhlops (Bruun & Kaiser, 1944) es una especie catalogada como “Vulnerable” en la Lista Roja de la IUCN. Endémica de una única localidad situada en las montañas Zagros, en Irán occidental. Se trata de una especie omnívora que depende del plancton para alimentarse. Se estudió la distribución espacial y estacional del plancton en el hábitat original del barbo cavernícola iraní entre mayo de 2012 y febrero de 2013. Se midieron varios parámetros ambientales y se relacionaron con la distribución del plancton. La comunidad planctónica comprendía 13 géneros y cinco especies. El filo Rotifera tenía el mayor número de géneros (4) y de especies (4), seguido por Arthropoda (3), Ochrophyta (3), Myzozoa (2), Charophyta (2), Chlorophyta (2), Ciliophora (1) y Cryptophyta (1). Por lo que respecta a la cantidad, las especies dominantes de fitoplancton y zooplancton fueron Achnanthidium sp. y Lecane sp. Los coeficientes de correlación de Pearson pusieron de manifiesto que la relación entre las comunidades de plancton y los parámetros ambientales era baja pero significativa. Entre los parámetros ambientales, el total de sólidos en suspensión y la turbidez parecieron ser los más influyentes en la distribución temporal de las especies de plancton. Asimismo, se observó que el oxígeno disuelto desempeñaba una función importante para la mayoría de las especies de plancton, al igual que la temperatura para la mayoría de las especies de zooplancton. La diversidad y la abundancia de fitoplancton y zooplancton eran bajas durante todo el año en la cueva con una media anual de 96,4 ind./l y no mostraron ningún máximo durante el año.La composición planctónica y los parámetros ambientales en el hábitat del barbo cavernícola iraní Iranocypris typhlops El barbo cavernícola iraní, Iranocypris typhlops (Bruun & Kaiser, 1944) es una especie catalogada como “Vulnerable” en la Lista Roja de la IUCN. Endémica de una única localidad situada en las montañas Zagros, en Irán occidental. Se trata de una especie omnívora que depende del plancton para alimentarse. Se estudió la distribución espacial y estacional del plancton en el hábitat original del barbo cavernícola iraní entre mayo de 2012 y febrero de 2013. Se midieron varios parámetros ambientales y se relacionaron con la distribución del plancton. La comunidad planctónica comprendía 13 géneros y cinco especies. El filo Rotifera tenía el mayor número de géneros (4) y de especies (4), seguido por Arthropoda (3), Ochrophyta (3), Myzozoa (2), Charophyta (2), Chlorophyta (2), Ciliophora (1) y Cryptophyta (1). Por lo que respecta a la cantidad, las especies dominantes de fitoplancton y zooplancton fueron Achnanthidium sp. y Lecane sp. Los coeficientes de correlación de Pearson pusieron de manifiesto que la relación entre las comunidades de plancton y los parámetros ambientales era baja pero significativa. Entre los parámetros ambientales, el total de sólidos en suspensión y la turbidez parecieron ser los más influyentes en la distribución temporal de las especies de plancton. Asimismo, se observó que el oxígeno disuelto desempeñaba una función importante para la mayoría de las especies de plancton, al igual que la temperatura para la mayoría de las especies de zooplancton. La diversidad y la abundancia de fitoplancton y zooplancton eran bajas durante todo el año en la cueva con una media anual de 96,4 ind./l y no mostraron ningún máximo durante el año.The Iranian cave barb (Iranocypris typhlops Bruun & Kaiser, 1944) is ‘Vulnerable’ in the IUCN Red List. It is an endemic species of ray–finned fish of the family Cyprinidae from a single locality in the Zagros Mountains, western Iran. This species is an omnivore that depends on plankton for food. We studied the spatial and seasonal distribution of plankton in the native habitat of the Iranian cave barb between May 2012 and February 2013. We measured various environmental parameters and related these to plankton distribution. The plankton assemblage included 13 genera and five species. Rotifera had the highest number of genera (4) and species (4), followed by Arthropoda (3), Ochrophyta (3), Myzozoa (2), Charophyta (2), Chlorophyta (2), Ciliophora (1) and Cryptophyta (1). In terms of numbers, the dominant species of phytoplankton and zooplankton were Achnanthidium sp. and Lecane sp. Pearson correlation coefficients showed a low but significant relationship between plankton communities and environmental parameters. Among the environmental parameters, total suspended solids and turbidity seemed to have the most important influence on the temporal distribution of plankton species. We also observed that dissolved oxygen played an important role for most plankton species, as did temperature for most zooplankton species. The diversity and abundance of phytoplankton and zooplankton were low throughout the year in the cave with an annual mean of 96.4 ind./l and they did not show any peaks during the year

    Breeding ecology of the Iranian ground jay (Podoces pleskei)

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    Although Podoces pleskei is the only endemic bird of Iran, little information exists on its ecological features, population dynamics and threats that concern it. This species occurs in desert and semi desert areas, mostly on the Iranian plateau, though its range spreads southeast ward to the Iran- Pakistan border. In this research, a total of 52 nests were studied in three locations, the “Ghare Tappe”, “Marvast” and “Mehrano” region, from 2005 to 2008. Breeding habits, nest characteristics, hatching features, clutch size, length of incubation time, nesting period and features of the chicks were observed in the three locations and were analyzed using analysis of variance (ANOVA). To compare breeding success among the three study areas, Z test was applied. This bird builds its nest at the top of and within the denser parts of plants, particularly Atraphaxis spinosa, Ephedra intermedia and Zygophyllum eurypterum. At times of danger, they hide beneath shrubs. Z-tests showed that the breeding success of this bird varied between Marvast and Mehrano. The greatest cause of nest failure and chick mortality was the transcaspian desert monitor (Varanus griseus caspius), which feeds on the eggs and chicks.Key words: Breeding ecology, Pleske’s ground jay, nest characteristics, clutch size, nest success, threat

    On high-temperature evolution of passivation layer in Li–10 wt % Mg alloy via in situ SEM-EBSD

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    Li–10 wt % Mg alloy (Li–10 Mg) is used as an anode material for a solid-state battery with excellent electrochemical performance and no evidence of dendrite formation during cycling. Thermal treatment of Li metal during manufacturing improves the interfacial contact between a Li metal electrode and solid electrolyte to achieve an all solid-state battery with increased performance. To understand the properties of the alloy passivation layer, this paper presents the first direct observation of its evolution at elevated temperatures (up to 325°C) by in situ scanning electron microscopy. We found that the morphology of the surface passivation layer was unchanged above the alloy melting point, while the bulk of the material below the surface was melted at the expected melting point, as confirmed by in situ electron backscatter diffraction. In situ heat treatment of Li-based materials could be a key method to improve battery performance
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