15,157 research outputs found
Determination of effective stress-effective strain relationship for use as a machinability index
In recent work it has been shown that the effective stress effective
strain relationship of a work material is important in determining the
shear angle in orthogonal cutting. This note describes the method of
obtaining this relationship
Recommended from our members
Standardization and the production of justice in summary criminal courts: a post human analysis
Since the 1980s, successive governments have become increasingly distrustful of professional judgment in those services which remain funded by the state, including the criminal justice system. Against this background, governments sought to increase efficiency in summary criminal courts. One way that this seems to have occurred is via the use of standardized forms in case progression. During 2013, Welsh conducted empirical research in which the reliance placed on standardized case management forms became apparent. We argue, drawing on post-humanist vocabularies to inform our analytic framework, that such documents may have shifted the temporality of summary criminal justice, which has the (perhaps unintended) consequence of (further) marginalizing defendant participation and limiting the types of legal issue that are litigated. These documents and processes, therefore, participate in the development of a particularized, and temporally situated, form of ‘justice’
COMMITTEE ON EXTERNAL ECONOMIC RELATIONS. DRAFT REPORT on the renewal of the Multi-Fibre Arrangement with particular reference to the situation of the European textile industry. EXPLANATORY STATEMENT: PART B. 5 March 1981
Report drawn up on behalf of the Committee on Economic and Monetary Affairs on the proposal for a block exemption on motor vehicle distribution and servicing agreements. Working Documents 1984/85, Document 1-192/84, 5 May 1984
Spin chains and channels with memory
In most studies of the channel capacity of quantum channels, it is assumed
that the errors in each use of the channel are independent. However, recent
work has begun to investigate the effects of memory or correlations in the
error. This work has led to speculation that interesting non-analytic behaviour
may occur in the capacity. Motivated by these observations, we connect the
study of channel capacities under correlated error to the study of critical
behaviour in many-body physics. This connection enables us the techniques of
many-body physics to either completely solve or understand qualitatively a
number of interesting models of correlated error. The models can display
analogous behaviour to associated many-body systems, including `phase
transitions'.Comment: V2: changes in presentation, some additional comments on
generalisation. V3: In accordance with published version, most (but not all)
details of proofs now included. A separate paper will shortly be submitted
separately with all details and more result
Reply to the comment on 'Validity of certain soft photon amplitudes'
We respond to the accompanying Comment on our paper, 'Validity of certain
soft photon amplitudes'. While we hope the discussion here clarifies the
issues, we have found nothing which leads to a change in the original
conclusions of our paper.Comment: 6 pages, Latex, uses ReVTeX, now publishe
A review of knowledge: inter-row hoeing & its associated agronomy in organic cereal & pulse crops
The aim of this project was to establish the “state of the art” for inter-row hoeing and its associated agronomic practices in organic cereal and pulse crops. To achieve this a detailed review of literature was undertaken.
• To facilitate inter-row cultivation in cereal and pulse crops, some adjustment of row spacing may be required. For cereals, drilling crops in 25 cm rows can reduce yield compared with normal drilling practice, primarily due to greater intra-specific competition amongst the crop (i.e. competition between crop plants).
• The yield penalty resulting from widely spaced crop rows can be minimised using a number of approaches, depending on the drill:
1. Reducing the seed rate in widely spaced crop rows can help to minimise excessive intra-specific competition.
2. Band sowing the crop in wide rows can also help to minimise intra-specific competition as the seed is distributed over a greater area.
3. Using a twin-row arrangement can completely overcome the yield penalty.
• The recommended row spacing for peas (up to 20 cm) and beans (up to 35 cm) does not require any further adjustment for inter-row hoeing.
• Recent developments in automated guidance of inter-row hoeing equipment mean that weeding operations can now be conducted a much higher speeds (10 km h-1). This has highlighted the limitations of some of the cultivators currently used (e.g. ‘A’ blades), as excessive soil throw can occur at this high speed. Rolling cultivators may prove to be the most suitable at high forward speeds. For manually guided hoes working at slower speeds (5 km h-1), ‘A’ and ‘L’ blades offer an effective low cost solution.
• In terms of the timing of inter-row hoeing, it is suggested that weeding operations should be conducted at an early stage in the growing season, as the weeds that emerge with or shortly after the crop are the ones that pose the most significant threat for crop yield. Weeding on two occasions can provide better levels of weed control than weeding once, but weeding more frequently offered little additional benefit. Reductions of weed biomass of up to 99 % have been reported as a result of inter-row hoeing, although this has not always resulted in a positive crop yield response. This is probably due to crop damage resulting from inaccurate hoeing, a problem that can be overcome with automated guidance.
• There is some evidence to suggest that mechanical weeding operations can mineralise soil bound nitrogen.
• The impact of inter-row hoeing on ground nesting birds is uncertain. Early indications suggest that skylarks prefer to nest directly adjacent to or in the crop row rather than between rows.
The information contained within this review should enable farmers to make best use of inter-row hoeing in their arable crops.
There are a number of areas that require further research and development:
• The interaction of seed rate and row spacing needs to be confirmed in organic systems.
• Relatively little is known about the mechanisms of weed kill and the detailed interaction between the cultivator blade, the weed and the soil. This is particularly important with the new automated guidance equipment that allows weeding at high forward speeds.
• The timing and frequency of inter-row hoeing has received very little attention. The optimum weed control timings are based on small-plot crop:weed competition studies and need to be verified under field scale management with inter-row hoeing equipment.
• Finally, the impact of inter-row hoeing and widely spaced crop rows on ground-nesting birds has not been looked at directly, but is of importance.
Please see the main report for a more detailed summary before the full text
Gas Absorption Detected from the Edge-on Debris Disk Surrounding HD32297
Near-infrared and optical imaging of HD32297 indicate that it has an edge-on
debris disk, similar to beta Pic. I present high resolution optical spectra of
the NaI doublet toward HD32297 and stars in close angular proximity. A
circumstellar absorption component is clearly observed toward HD32297 at the
stellar radial velocity, which is not observed toward any of its neighbors,
including the nearest only 0.9 arcmin away. An interstellar component is
detected in all stars >90 pc, including HD32297, likely due to the interstellar
material at the boundary of the Local Bubble. Radial velocity measurements of
the nearest neighbors, BD+07 777s and BD+07 778, indicate that they are
unlikely to be physically associated with HD32297. The measured circumstellar
column density around HD32997, log N(NaI) ~ 11.4, is the strongest NaI
absorption measured toward any nearby main sequence debris disk, even the
prototypical edge-on debris disk, beta Pic. Assuming that the morphology and
abundances of the gas component around HD32297 are similar to beta Pic, I
estimate an upper limit to the gas mass in the circumstellar disk surrounding
HD32297 of ~0.3 M_Earth.Comment: 13 pages, 2 figures; Accepted for publication in ApJ Letter
- …
