We present a measurement of the cosmic-ray spectrum above 100 PeV using the part of the surface detector of the Pierre Auger Observatory that has a spacing of 750 m. An inflection of the spectrum is observed, confirming the presence of the so-called second-knee feature. The spectrum is then combined with that of the 1500 m array to produce a single measurement of the flux, linking this spectral feature with the three additional breaks at the highest energies. The combined spectrum, with an energy scale set calorimetrically via fluorescence telescopes and using a single detector type, results in the most statistically and systematically precise measurement of spectral breaks yet obtained. These measurements are critical for furthering our understanding of the highest energy cosmic rays.
More than half a century after the discovery of ultra-high energy cosmic rays (UHECRs), their origin is still an open question. The study of anisotropies in the arrival directions of such particles is an essential ingredient to solve this puzzle. We update our previous analysis of large-scale anisotropies observed by the Pierre Auger Observatory using the latest data collected before the AugerPrime upgrade. We select events with zenith angles up to 80 degrees, implying a sky coverage of 85%, and energies above 4 EeV, for which the surface detector of the Observatory is fully efficient. Dipolar and quadrupolar amplitudes are evaluated through a combined Fourier analysis of the event count rate in right ascension and azimuth. The analysis is performed in three energy bins with boundaries at 4, 8, 16 and 32 EeV and two additional cumulative bins with energies above 8 and 32 EeV. The most significant signal is a dipolar modulation in right ascension for energies above 8 EeV, as previously reported, with statistical significance of 6.6 . Additionally, we report the measurements of the angular power spectrum for the same energy bins with the same dataset.
A search for ultra-high-energy photons at the Pierre Auger Observatory exploiting air-shower Universality Pierpaolo Savina a,b,c,d, * on behalf of the Pierre Auger e Collaboration
ABSTRACT. The objective of this study was to compare tests used to identify vigor in soybean seeds and to establish a model that relates the seeds' vigor, as determined in the laboratory, with field emergence. Five soybean cultivars were evaluated based on their germination, sand emergence, immersion in sodium hypochlorite, accelerated aging, controlled deterioration, cold test, seedling growth, electrical conductivity, tetrazolium, emergence percentage, seedling length in the field and seedling dry weight. The experimental design was completely randomized and means were compared by the Tukey test at 5% probability. Assays for accelerated aging, controlled deterioration and tetrazolium showed the closest correlation to field emergence. The regression model included the sand emergence speed, germination speed index and index of sand emergence speed as the variables that best correlated with field emergence.Keywords: germination, seeds quality, regression model.Comparação de testes para análise de vigor em sementes de soja e sua relação com a emergência em campo RESUMO. O objetivo deste trabalho foi comparar testes utilizados para indicar o vigor de sementes de soja, e estabelecer um modelo que relacione os testes de vigor propostos até o momento com a emergência das plântulas em campo. Foram utilizadas cinco cultivares de soja as quais foram submetidas aos seguintes testes de vigor: germinação, emergência em areia, hipoclorito de sódio, envelhecimento acelerado, deterioração controlada, teste de frio, crescimento de plântulas (comprimento da plântula e peso de matéria seca da plântula), condutividade elétrica, tetrazólio, porcentagem de emergência e comprimento das plântulas no campo e massa seca de plântula. O delineamento experimental utilizado foi o inteiramente casualizado com quatro repetições e as médias foram comparadas pelo teste de Tukey a 5% de probabilidade. Concluiu-se que os testes de envelhecimento acelerado, deterioração controlada e tetrazólio demonstraram mais eficiência quanto a distinguir a diferença de vigor entre as cultivares. O modelo de regressão contemplou a velocidade de emergência em areia, o índice de velocidade de germinação (IVG) e o índice de velocidade de emergência em areia, como as variáveis que melhor se relacionam com a emergência em campo.Palavras-chave: germinação, qualidade de sementes, modelo de regressão.
R ESU M OOs atributos químicos e físicos do solo apresentam, frequentemente, dependência espacial. Portanto, é imprescindível estudar sua variabilidade espacial visando ao manejo mais preciso da lavoura, a redução do impacto ambiental, a otimização do uso de máquinas e o aumento da eficiência das equipes de trabalho. Assim, o objetivo deste trabalho foi avaliar a variabilidade espacial de atributos físicos de um Latossolo Vermelho distroférrico típico após o cultivo de soja. Os dados foram coletados em uma área de 2 ha cultivada sob sistema de plantio direto utilizando-se uma grade amostral de 30 x 33 m, em que foram avaliados os parâmetros: macroporosidade, microporosidade, porosidade total, densidade e umidade do solo, na camada de 0 -0,1 m; após as análises exploratória e geoestatística, os modelos teóricos foram ajustados aos semivariogramas para cada atributo; já a interpolação dos dados foi realizada utilizando-se a krigagem ordinária, verificando-se que todas as variáveis estudadas apresentaram dependência espacial, que variou entre moderada (macroporosidade, porosidade total e umidade do solo) e forte (microporosidade e densidade do solo), em função do coeficiente de efeito pepita. Palavras-chave: geoestatística, porosidade do solo, umidade do solo, densidade do solo Spatial variability of physical attributes of a distroferric Red Latosol after soybean crop A B ST R A C TThe chemical and physical properties of a soil often show a spatial dependence. Thus, it is important to study their spatial variability, aiming to improve the crop management, to reduce the environmental impact, to optimize the machinery use, and to increase the efficiency of staff. So, this study aimed to evaluate the spatial variability of the physical properties of a distroferric Red Latosol (Typic Haplorthox) after soybean crop. The data were collected in an area of 2 ha managed under no tillage system, using a sampling grid of 30 x 33 m, where it was evaluated the macro, micro and the total porosity, the bulk density and the soil water content in 0 -0.1 m layer. After the exploratory and geostatistical analyses, the theoretical models were set to the semivariograms for each attribute. The data interpolation was performed using the ordinary kriging. All the variables showed spatial dependence, which ranged from moderate (macroporosity, total porosity and soil water content) to strong (microporosity and bulk density), according to the nugget effect coefficient.
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