Educação matemática pela arte
Gusmão, Lucimar Donizete
2013-08-28
Search results
66,926 records were found.
Acid soils limit the growth of aluminum-(Al) sensitive crops such as alfalfa (Medicago sativa L.). Management of acid subsoils can be difficult due to physical and economic constraints. Field experiments were conducted at two locations to evaluate the effectiveness of surface-applied gypsum and a flue gas desulfurization by-product for reducing the toxic effects of acid subsoils on alfalfa. The materials were applied at rates of 0, 5, 10, and 15 Mg ha-1. In addition, a glasshouse experiment was conducted that used 0, 5, and 10 Mg ha-1 of gypsum only. Field studies were concluded 41 and 45 months after treatment application at the two locations. No effect of material on alfalfa yield or tissue mineral concentration was observed. Also, rate did not affect yield. However, there were differences in plant tissue mineral concentration i...
Cotton (Gossypium hirsutum) is able to survive relatively large levels of both water and
salinity stress. The objective of this study was to evaluate cotton lint production and soil
salinization under a conjunctive use strategy using saline water at deficit levels. A three-year
experiment applying irrigation at deficit amounts on cotton was conducted in Pecos, Texas on a
Hoban silty clay loam. Treatments were four irrigation water qualities, conjunctively applied.
Initial irrigation was with water having an electrical conductivity (ECIW) of 4.5 dSm-1,
representing about one-third of the total amount of water applied. Thereafter, treatments were
applied using water of varying ECIW, e.g., 1.5, 4.5, 9.0, and 15.0 dSm-1 for all subsequent
irrigations. Total irrigation plus rain was approximately two-thirds of full water requirements.
Lint ...
A study was conducted to assess the effects of two instructional strategies: manipulative-based instruction and visual cues in mathematics (both enhanced by explicit vocabulary enrichment) in a small group setting with young Hispanic students who are English language learners. The duration of the study was five weeks. Sixty-four third and fourth grade students were selected for participation based on their performance with problem solving items from the four release tests for 1999-2002 mathematics Texas Assessment of Academic Skills (TAAS) for third and fourth grades. A pre-assessment composed of 10 of the 13 TAAS objectives were administered. The four pre-selected objectives on which the students scored the lowest were identified for further instruction and assessment. The student population was limited to those of the original si...
The saga of the American bison (Bison bison) is a well-known story of death, destruction, and greed circumvented by early conservationists. The foresight of 5 cattlemen and the Canadian and U.S. governments at the apex of the population bottleneck in the 1880s led to the eventual establishment of several federal bison populations, from which virtually all of the 300,000 extant bison are descended.
A survey of 54 microsatellite loci spanning each autosomal and both sex chromosomes was used to compare levels of genetic variation among 10 of the 11 federal bison populations in the U.S. Although most populations contain moderate levels of genetic variation, the majority of genetic variation is contained within only 4 of the federal populations surveyed. The distribution and partitioning of genetic variation confirm historical records of...
The physical, chemical, and antioxidant properties of extrudates prepared from specialty tannin sorghum (CSC3xR28) and Tx430 black sorghums were evaluated. White food type sorghums (ATx631xRTx436) and commercial corn meal were also extruded. Sorghums were extruded as whole kernels or cracked (broken) kernels through a Maddox MX-3001 high-friction extruder. Cracked sorghum fortified with bran (0 -50%) derived from decortication or roller-milling were also extruded. Tannin sorghums extruded similarly to white food-type sorghums, with very little difference in extrudate quality. Cracking the sorghums produced lower feed rates, higher specific mechanical energy (SME) and extrudates that were less dense, more expanded, and softer than whole kernel extrudates. Whole and cracked sorghum materials had feed rates similar to corn meal, but low...
Beef subprimals (n = 356), representing USDA Low Choice and Select grades,
were obtained from a major beef processor. Selected subprimals represented the normal
weight variation and standard packer fat trim levels associated with commodity boxed
beef. The subprimals selected included beef rib, blade meat; beef rib, ribeye roll, lip-on,
bone-in; beef rib, ribeye roll (0x0); beef rib, ribeye, lip-on (2x2) (5.08 cm x 5.08 cm);
beef rib, ribeye, lip-on modified (1x1) (2.54 cm x 2.54 cm); beef rib, ribeye (IM,
individual muscle); beef rib, ribeye cap (IM); beef chuck, outside shoulder clod,
trimmed; beef chuck, outside shoulder clod, top blade roast; beef chuck, square cut,
pectoral meat (IM); beef chuck, chuck roll; beef plate, inside skirt (IM); beef round, top
(inside) untrimmed; beef round, outside round (flat); beef round, eye of round...
Torsional vibration is an oscillatory angular twisting motion in the rotating members of a system. It can be deemed quite dangerous in that it cannot be detected as easily as other forms of vibration, and hence, subsequent failures that it leads to are often abrupt and may cause direct breakage of the shafts of the drive train. The need for sufficient analysis during the design stage of a rotating machine is, thus, well justified in order to avoid expensive modifications during later stages of the manufacturing process. In 1998, a project was initiated by the Turbomachinery Research Consortium (TRC) at Texas A&M University, College Station, TX, to develop a suite of computer codes to model torsional vibration of large drive trains. The author had the privilege of developing some modules in Visual Basic for Applications (VBA-Excel) for ...
Reproductive, maternal, and weight traits were analyzed for Angus (A), Brahman
(B), and Hereford (H) straightbred cows; F1 and F2 BA and BH cows; and 3/8 B 5/8 A
first (Bn) and second (Bn2) generation cows in Central Texas. Heterosis was estimated
for calf crop born (CCB), calf crop weaned (CCW), and cow weight at palpation (PW)
by linear contrasts within cow breed groups. F1 BA cows expressed heterosis (P<0.01)
for CCB (0.10) and CCW (0.11), while F2 BA cows expressed negative heterosis
(P<0.10) for CCB (-0.06) and CCW (-0.07). F1 BH cows expressed heterosis (P<0.001)
for CCB (0.15) and CCW (0.16), and F2 BH cows retained F1 heterosis (P<0.001) for
CCB (0.13) and CCW (0.15). Bn2 cows expressed heterosis (P<0.01) for CCB (0.14),
but Bn cows did not express heterosis (P>0.10) for CCB or CCW. Only the F1 BA (22.9
kg) and F2 BH (42.1 kg) ...
Because of limited tester time and memory, a primary goal of digital circuit manufacture test generation is to create compact test sets. Test generation programs that use Ordered Binary Decision Diagrams (OBDDs) as their primary functional representation excel at this task. Unfortunately, the use of OBDDs limits the application of these test generation programs to small circuits. This is because the size of the OBDD used to represent a function can be exponential in the number of the function's switching variables. Working with these functions can cause OBDD-based programs to exceed acceptable time and memory limits. This research proposes using Ordered Partial Decision Diagrams (OPDDs) instead as the primary functional representation for test generation systems. By limiting the number of vertices allowed in a single OPDD, complex...
The main objective of this work is to demonstrate some new computational methods
for estimation, optimization and modeling of dynamical systems that use automatic
differentiation. Particular focus will be upon dynamical systems arising in Aerospace
Engineering. Automatic differentiation is a recursive computational algorithm, which
enables computation of analytically rigorous partial derivatives of any user-specified
function. All associated computations occur, in the background without user
intervention, as the name implies. The computational methods of this dissertation are
enabled by a new automatic differentiation tool, OCEA (Object oriented Coordinate
Embedding Method). OCEA has been recently developed and makes possible efficient
computation and evaluation of partial derivatives with minimal user coding. The key
results in this d...
