Draft

Abstract A single-acting (3 × 3) 510 mm powered disc harrow was developed to achieve timeliness in operation in the extensively followed rice-wheat cropping system by reducing tillage passes with the proper incorporation of residues left after rice cultivation. Experiments were carried out at forward speeds of 3.69, 4.67 and 6.55 km h−1 corresponding to speed ratios of 4.74, 3.75 and 2.67, respectively and at 90, 120 and 140 mm operating depths in sandy clay loam soil having an average moisture content of 12 ± 0.75% (db) and cone index of 930 ± 40 kPa. Its comparison was also made with conventional free rolling disc tilling which generally requires more passes. Optimum performance in terms of tillage performance index was achieved at speed ratio of 3.75 with a reduction in draft, slip, and clod size by 30–36%, 53.47–72.25% and 39.20–60.73%, respectively at the cost of 14.28–18.40% increase in fuel consumption (l ha−1) when operated at depth of 120 mm as compared to free rolling mode indicating better energy utilization. Effect of multiple passes of tilling on soil compaction beneath the tillage depth (100–200 mm) was also studied from separate experiments. Soil compaction was observed to be 4.71–7.17% and 5.21–6.86% lesser as compared to that obtained with rotavator after first and second passes of tillage, respectively. However, it was about 0.38–3.00% and 3.00–5.32% more compared to free rolling disc tilling after first and second passes, respectively. Reduced number of passes required for preparing seedbed with powered disc justifies its use for carrying out the tillage.

Equipping tines with the wings increases draft and soil loosening. Wing
angles affect tine performance, soil aggregation and remained residue. In this research, conventional wing with no bent plus backward and forward bent wings with bend angles of 10 and 20° were attached to both a subsoiler and paraplow tine. The rake angle of all wings was 15°. The effects of tine and wing on draft, soil disturbance area, specific draft,
remained residue, and mean weight diameter (MWD) were investigated
in a clay loam soil at depth of 40 cm and speed of 1.6 km h−1. The effect of tine and wing plus interaction of them on all parameters was significant (p < 0.01) with the exception of remained residue. The bent winged tines required higher draft and caused higher disturbance area,
lower specific draft, and lower MWD than the conventional tines and
those without wing. The highest draft, disturbed area and remained
residue plus the lowest specific draft and MWD were obtained when
applying the 10° forward bent-winged tines. In present work, the paraplow equipped with forward bent wings with a bend angle of 10° was suggested as a suitable tool for deep soil loosening under a conservation tillage system.

Der einführende Beitrag versucht, nach der Erläuterung des Konzepts einer „lernförderlichen Begleitforschung“ den medientheoretischen Begriff „Format“ für die Erwachsenenpädagogik nutzbar zu machen. Daran anknüpfend nimmt er den speziellen Typus „Programmformat“ in den Blick. An ihm lässt sich verdeutlichen, was Nachhaltigkeit im Sinne von „Auf-Dauer-Stellen“ auf der Ebene eines Programmformats für ein pädagogisches Verständnis von Verbandsarbeit meint und welche Konsequenzen dies für professionelles Weiterbildungsmanagement haben kann. Abschließend werden zusammenfassend die konzeptionellen Eckpunkte eines einrichtungsübergreifenden Programmformats Lernort Gemeinde charakterisiert. (DIPF/ Orig.)

Biologische Ansatze zur Erklarung von »geschlechtsspezifischer Sozialisation« erleben derzeit eine Renaissance. Ihrer Unterkomplexitat wird ein Konzept entgegengesetzt, das »Sozialisation in alltaglicher Lebensfuhrung« begreift. In ihm sind Prozesse des Doing Gender ebenso verankerbar wie Gender als Institution. Mit dem Habitusbegriff wird Geschlecht sowohl als vergeschlechtlichtes Merkmal wie als vergeschlechtlichende Praxis fasbar. Dabei durfen Machtverhaltnisse jedoch nicht auser Betracht bleiben. Vor allem in den Ansatzen der hegemonialen Mannlichkeit bzw. der mannlichen Herrschaft lassen sich Bedingungen aufzeigen, die erklaren, wie die Sozialisation der Geschlechter sich vollzieht und zugleich, wie Geschlechterverhaltnisse veranderbar sind. (DIPF/Orig.)

Although desalination of archaeological iron reduces its chloride concentration and enhances object stability, the reduction in corrosion rate that this produces has never been quantified. This study measures post-treatment corrosion rates in accelerated corrosion environments to identify the impact of removing chloride ions on corrosion rate. Thirty-five archaeological iron nails, treated individually in either alkaline sulphite or nitrogen-deoxygenated sodium hydroxide, were exposed to 75°C and 75% relative humidity together with 31 untreated objects from the same archaeological sites. Object weight change and visual examination of physical change before and after the test period were used to monitor corrosion. 77% of treated objects showed no weight gain and no visible signs of corrosion, while 90% of untreated objects did corrode. The impact of chloride on corrosion of untreated objects was clearly established by a significant linear correlation between chloride content and weight gain. Treated objects with <400 ppm chloride content showed no corrosion behaviour. Corrosion of treated objects was attributed to incomplete treatment: 93% of objects treated to <5 mg/l Cl− in the final solution bath displayed no corrosion behaviour. Based on these results, desalination of iron objects to enhance their stability offers a valuable option for reducing corrosion rates of archaeological iron, which should increase object lifespan. The results also raise the question of whether low levels of post-treatment residual chloride produce corrosion of any significance. Answering this will be an important step forward for managing the preservation of archaeological iron.

Office workers’ preferences for air movement have been extracted from a database of indoor environmental quality surveys performed in over 200 buildings. Dissatisfaction with the amount of air motion is very common, with too little air movement cited far more commonly than too much air movement. Workers were also surveyed in a detailed two-season study of a single naturally ventilated building. About one-half the building’s population wanted more air movement and only 4% wanted less. This same ratio applied when the air movement in workspaces was higher than 0.2 m/s, the de facto draft limit in the current ASHRAE and ISO thermal environment standards. Preference for “less air motion” exceeded that for “more” only at thermal sensations of −2 (cool) or colder. These results raise questions about the consequences of the ASHRAE and ISO standards’ restrictions on air movement, especially for neutral and warm conditions.

Rising urban and environmental demand for water has created growing pressure to re-allocate water from traditional agricultural uses. The evolution of water markets has been more complicated than those for other resources. In this paper, we first explain these differences by examining water rights and regulatory issues. Second, we place our research in the context of the economics literature on water marketing. Third, we present new, comprehensive data on prices and the extent, nature, and timing of water transfers across 12 western states from 1987-2005. We find that prices are higher for agriculture-to-urban trades versus within-agriculture trades, in part, reflecting the differences in marginal values between the two uses. Prices for urban use are also growing relative to agricultural use. Markets are responding in that the number

Stationary reciprocal processes defined on a finite interval of the integer line can be seen as a special class of Markov random fields restricted to one dimension. Non stationary reciprocal processes have been extensively studied in the past especially by Jamison, Krener, Levy and co-workers. The specialization of the non-stationary theory to the stationary case, however, does not seem to have been pursued in sufficient depth in the literature. Stationary reciprocal processes (and reciprocal stochastic models) are potentially useful for describing signals which naturally live in a finite region of the time (or space) line. Estimation or identification of these models starting from observed data seems still to be an open problem which can lead to many interesting applications in signal and image processing. In this paper, we discuss a class of reciprocal processes which is the acausal analog of auto-regressive (AR) processes, familiar in control and signal processing. We show that m...

This article reports on the experience of members of an Australian Aboriginal community as they used synchronous computer technologies to enhance their literacy learning. The aspiration to learn meaningful and relevant literacy and computer skills was discussed in focus groups, as well as the need to articulate the group&#39;s position within the wider community, the value of the wisdom of the Elders, and the importance of the dissemination of traditional language and Aboriginal knowledge. Educational integrity was deeply embedded in the project&#39;s approach to the Aboriginal learning experience, and included ensuring respect for cultural needs and traditions, as well as acknowledging the learners as active participants of their own learning. Successful implementation of the project led to the creation of the Community Strength Model (CSM) based on the premise of Henderson&#39;s multiple cultural model, which incorporates ethnic minority and Indigenous culture as a cultural logic ...