Time filter

Source Type

Laranjeiras do Sul, Brazil

Maule M.,Federal University of Rio Grande do Sul | Comba J.L.D.,Federal University of Rio Grande do Sul | Torchelsen R.P.,UFFS | Bastos R.,Nvidia
Computers and Graphics (Pergamon) | Year: 2011

Transparency is an important effect for several graphics applications. Correct transparency rendering requires fragment-sorting, which can be more expensive than sorting geometry primitives, and can handle situations that might not be solved in geometry space, such as object interpenetrations. In this paper we survey different transparency techniques and analyze them in terms of processing time, memory consumption, and accuracy. Ideally, the perfect method computes correct transparency in real-time with low memory usage. However, achieving these goals simultaneously is still a challenging task. We describe features and trade-offs adopted by each technique, pointing out pros and cons that can be used to help with the decision of which method to use in a given situation. © 2011 Elsevier Ltd. All rights reserved. Source

Heldwein A.B.,Federal University of Santa Maria | Maldaner I.C.,Instituto Federal Farroupilha | Radons S.Z.,UFFS | Loose L.H.,Federal University of Santa Maria | And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2012

This study aimed to develop models for estimating the net radiation (Q *) from the incident solar radiation (Rg) on canopies of sunflower plants. The experiments were conducted at the Plant Science Department of the Federal University of Santa Maria in 2007, 2008 and 2009 years. Q* was measured by net radiometers above the plants and Rg by automatic weather stations. For purposes of calculation, daily sums of Q* and Rg were performed, obtaining the relationship between Q* and Rg for each day. Models with high coefficient of determination and low RQME were obtained in test between measured and estimated values from an independent database, indicating precision to estimate net radiation in sunflower canopies, regardless of cultivation time in year. The general linear function with data obtained from different times of cultivation was: Q* = 0.5285 Rg (R 2 = 0.95), that the test showed RQME = 1.04 MJ m -2 d -1. It was concluded that net radiation (Q*) can be estimated using solar radiation measured by an automatic stations with sufficient accuracy for different purposes in sunflower agrometeorology. Source

dos Santos D.,UFFS | Guimaraes V.F.,West Parana State University | Klein J.,West Parana State University | Fioreze S.L.,Sao Paulo State University | Macedo Junior E.K.,West Parana State University
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2012

The water restriction can damage the performance of crops, especially in the flowering period. Thus, the aim of this research was to evaluate the response of genotypes of wheat submitted to water deficit in the beginning of flowering. The experiment was conducted in greenhouse, in a completely randomized design, in factorial scheme 3 x 2, with five replications. The factors studied were: three wheat cultivars (Coodetec (CD) 105, 108 and 111) and 2 irrigation managements (with and without imposition of water deficit). During the period of water deficit imposition, gravimetric soil moisture and the relative content of water in leaf were evaluated, while at the moment of rehydration the biometric variables were determined. At the end of the crop cycle the components of production were evaluated. Reduction was found in the gravimetric soil moisture, in the relative levels of water and in all biometric variables, in function of the water deficit. The grain production showed difference only among the water regimes, in which the cultivar CD 111 is more efficient in the maintenance of the productive potential in conditions of water deficit, through the quick recovery in the relative content of water in leaves. Source

Schulz D.G.,West Parana State University | Fey R.,UFFS | Malavasi U.C.,West Parana State University | De Matos Malavasi M.,West Parana State University
Floresta | Year: 2014

This essay compared development and fruit production of Jatropha curcas L. in relation to growing space and presence of an herbaceous competitor. The essay was composed by two circular plots with four plant growing areas (1.57 m2, 3.92 m2, 6.28 m2, and 8.63 m2) with eight replications for plot intercropped or not with Tifton 85. The cultivation of physic nut in the spacing of 6.28 m2 resulted in lower plant height and higher levels of leaf nitrogen and phosphorus, while the 1,57 m2 spacing resulted in increased plant height. The lowest values for plant height, number of leaves, number of fruits, SPAD index, and levels of nitrogen and phosphorus resulted in the intercropped plot. However, the 1.57 m2 spacing yelded higher stem diameter. Crown diameter presented the highest values in the 3.92 m2 spacing while the 1.57m2 limited the crown expansion. Maximum fruit production in monocrop plot was reached 18 months after planting date, which corresponded to the warmest season independently of planting space. Source

Uliana M.B.,West Parana State University | Fey R.,UFFS | Malavasi M.M.,West Parana State University | Malavasi U.C.,West Parana State University
Floresta | Year: 2014

This essay evaluated the development of seedlings of Anadenanthera macrocarpa as a function of substrates made from decomposed sugarcane and fertigation frequency. The essay was conducted in a randomized block design with three fertigation frequencies (7, 14 or 21 days) plus a control (without fertigation) and three substrates from decomposed sugarcane mixed with humus, vermiculite, vermiculite and sand, and a commercial substrate (control). Measurements included seedling height, stem diameter, and shoot and root biomass at 50, 80, 110, and 140 days after seed emergence. The results revealed faster growth of Anadenanthera macrocarpa seedlings produced with decomposed sugarcane mixed with humus 7:3 (v/v), while fertigation frequency had little effect upon seedling growth. Source

Discover hidden collaborations