Plow Power Requirements for Forestry Site Preparation
Abstract In this field study, data were collected to determine power requirements required by a trailing site preparation plow and the magnitudes of dynamic forces experienced by a plow during normal operation and during impact with stumps or other obstructions. Drawbar pull data were collected from five different tillage treatments on a recently harvested loblolly pine (Pinus taeda) site in central Alabama. The five treatments were: 1) a coulter, ripping shank, and four bedding disks; 2) a coulter, ripping shank, and two bedding disks; 3) a coulter and ripping shank; 4) a coulter alone; and 5) a ripping shank alone. A 330 kN [75 000 lb] capacity tension load cell was used to measure the drawbar load, a GPS receiver recorded tractor speed, four direct current displacement transducers (DCDT’s) monitored the depth of the disks, and two optical tachometers measured the speed of the tractor’s front and rear drive shafts. Each treatment produced significantly different drawbar loads (to alpha levels less than 0.001). The resulting mean loads were 46.0 kN [10 300 lb], 33.5 kN [7530 lb], 31.5 kN [7080 lb], 15.8 kN [3560 lb], and 43.4 kN [9760 lb] for treatments one through five, respectively. Maximum recorded drawbar load during a collision with a stump was 338.9 kN [76 188 lb].
EVALUATION OF THE SUBSOILER TINE DESIGNED AND MANUFACTURED LOCALLY AND ITS EFFECT ON SOME POWER INDICATORS AND CORN YIELD
This research study was conducted at Gerdarasha field, College of Agriculture, University of Salahaddin in Erbil during summer, 2018 on a silty clay loam soil texture. The experiment used completely randomized block design with split plot and three replications. Tillage depth was the first factor that three deepness of (20 – 25), (30 – 35) and (40 – 45) cm were studied. The second factor included type of tine (conventional which was manufactured in Massey Ferguson Corporation and modified one with wings and angels). Since the corn is very sensitive to soil compaction, it was selected to be grown. For comparing, the machinery indicators and crop yield were measured and evaluated. The summarized considerable points were: Tillage depth was more influence on corn yield indicator which totally showed their highest values at the deepest tillage depth (40-45) cm and the lowest values at the shallowest depth (20 – 25) cm. The greater results were observed for this indicator and disturbed area by applying modified tine rather than conventional one (22.40% and 26.13% respectively),and, it increased by increasing the depth. Drawbar power was considerably affected when subsoiler increasing values were recorded by depth increasing. The highest value of that was recorded at the deepest depth when plow equipped with modified tine. Besides that, subsoiler showed better vertical stability at the shallower depths.
Treatment of sentence production deficits in aphasia: A linguistic-specific approach to wh-interrogative training and generalization
Abstract The present research examines the effects of a linguistic-specific treatment on acquisition and generalization of wh-interrogative structures in two aphasic subjects presenting with deficit patterns consistent with agrammatism. The underlying linguistic representation of sentence structures selected for treatment and generalization was considered based on aspects of Chomsky's (1981) Government Binding (GB) theory, and a linguistic-based, wh-movement treatment strategy was implemented. Using a single-subject multiple-baseline design across behaviours and subjects, the effects of treatment were explored by examining generalization patterns across wh question forms requiring wh-movement (movement of a direct object NP to COMP). Within question form generalization also was evaluated by examining formulation of untrained sentences of varied complexity—with complexity defined in terms of the number of phrasal nodes in the d-structure representation of sentences. Results indicated that for both subjects...