Fougerite (IMA 2003-057) was accepted by the Commission on New Minerals and Mineral Names of the International Mineralogical Association (IMA) in 2004 as a new mineral to represent the green rust (GR) family. The data on which it was approved, however, are inconsistent. X-ray diffraction patterns from the Fougères soils contain no peaks that could meaningfully be attributed to a GR phase. The sequential dissolution procedure used to identify GR in the soils was not rigorously tested for selectivity. If indeed it is selective, the results indicate the presence of 40–78% Fe in minerals other than GR. Other Fe-bearing phases were not included in the interpretation of the spectroscopy data that were presented. The data are consistent with the presence of Fe-bearing clays and other silicate minerals. In light of the ambiguous and conflicting data, we recommend that the case for fougerite as a mineral be re-evaluated by the IMA.

Farm animal welfare has now been studied, within a scientific framework, for several decades. The framework does not include ethical issues, but unless measurements of animal welfare at farm level are embedded in an ethical context, there is a danger that these measurements will not be properly utilised. This paper considers the relationship between ethical questions and animal welfare assessment. In it, the following four key ethical questions are identified. What is the baseline standard for morally acceptable animal welfare? What is a good animal life? What farming purposes are legitimate? What kinds of compromise are acceptable in a less-than-perfect world? The authors suggest that animal welfare scientists need to reflect carefully on these questions if welfare assessments are to be properly interpreted and put to practical use. Such reflection will lead to a more transparent appreciation of the values underlying welfare assessment. In this way, it will both offer welfare scientists a greater awareness of their own value-assumptions and enable the same scientists to communicate effectively with the wider audience — farmers, consumers, pressure groups, policy-makers and so on — for which the results of animal welfare assessments are of concern.

Nano-technology has a lot to contribute toward efforts for a sustainable environment. In addition to the promise of sensors, monitoring devices and functional particles, there is new, fundamental information to begaine d by applying nm-scale measuring techniques to natural materials. Improved understanding of the interaction of fluids with natural solids can lead us to new solutions for some of society’s problems, especially in the realm of clean water and safe treatment of waste. Ultra-high resolution lets us define the molecular-scale processes responsible for uptake of contaminants such as transition metals (e.g. Ni and Cr), radioactive species (e.g. Np) and organic compounds (e.g. glyphosate, a pesticide), while they adsorb on minerals such as calcite and Fe oxides and in some cases, are immobilized by solid-solution formation. With molecular-level resolution, we can see changes that with our traditional methods would only be visible after years or geological time.

Intercropping is a common practice in Africa, but the advantage compared to sole cropping depends on the crop plants and local agro-ecological conditions. The potential of intercropping maize (Zea mays) or sorghum (Sorghum bicolor) with watermelon (Citrullus lanatus) was tested in two on-farm trials in southern Mozambique under semi-arid conditions in an area with low and unpredictable rainfall. In the first experiment, plant density, yield and monetary value of sole and intercropping plots of maize with watermelon were determined in 17 farmers' fields in an area where all crops developed to maturity and harvest. There was a significant reduction in yield of both maize (28.8%) and watermelon (57.8%) in the intercrop compared with the sole crop yields. However, the mean land equivalent ratio of 1.13 for yield showed that intercropping had advantages as, on average, an area planted with sole crops would require 13% more land than an intercrop production to generate the same outcome. In the second experiment, carried out in another area with 16 farmers' fields, drought was more pronounced and only watermelon developed to maturity. Intercroppings with maize and sorghum resulted in 70% and 69% yield reduction, respectively. In conclusion, watermelon is a good companion crop for intercropping with cereals to mitigate the risk of total crop failure due to drought.

On-farm yield experiments were carried out in the Tombouctou region of Mali in 2009/10 under heat- and drought-prone desert conditions with three local landraces of seed-type watermelons. The landraces, named Fombou, Kaneye and Musa Musa by the farmers, exhibited distinct characteristics for fruit morphology, but in particular for seed traits. On average, the three landraces produced a fruit yield of 11·6 t/ha and an estimated seed yield of 364 kg/ha, with no significant differences among landraces. Kaneye showed the highest stability of fruit number/ha in different field environments, suggesting this landrace is the best among the three for a poor growing environment, whereas Fombou and especially Musa Musa responded positively to more favourable environments. Seed weight revealed a different trend, with Fombou as the most responsive to favourable conditions, while Kaneye and Musa Musa were less responsive. The yields obtained suggest that these local landraces of watermelon are valuable plant genetic resources for securing food supply in arid, heat- and drought-prone areas.

During the 20th century scientists have made genuine progress in explaining and modifying usefully the processes of life. The main leap forward was, of course, the rediscovery of Mendelian genetics at the beginning of the century. Since the 1930s this theory has been put to use in an ever more efficient and systematic way, particularly in breeding domestic animals with desired traits. Thus the animal breeder can now plan how he wants future generations of domestic animals to be, knowing that the plans will work.

During the 20th century scientists have made genuine progress in explaining and modifying usefully the processes of life. The main leap forward was, of course, the rediscovery of Mendelian genetics at the beginning of the century. Since the 1930s this theory has been put to use in an ever more efficient and systematic way, particularly in breeding domestic animals with desired traits. Thus the animal breeder can now plan how he wants future generations of domestic animals to be, knowing that the plans will work.

Over a period of seven years farmers participated in trials in which common vetch (Vicia sativa (V)) or chickling (Lathyrus sativus (C)) replaced the fallow in a barley (Hordeum vulgare)–fallow rotation (F) or were introduced into continuous barley cropping (B) – giving a total of four rotations, B–F, B–B, B–V and B–C. Trials on 4 ha, 2 ha per phase of each rotation, were replicated on 6–8 farms. Some vetch and chickling crops were grazed in spring. Mean seven-year dry matter yields were 2.91 t ha−1 for B–F, 4.82 t for B–B, 5.02 t for B–C and 5.32 t for B–V; total crude protein outputs were twice as high from rotations including legumes; and the B–V rotation yielded most metabolizable energy. Realizing the benefit, farmers started to adopt vetch. In 1991 three farmers were growing vetch on 7 ha but by 1997 174 farmers in 15 villages were growing vetch on 420 ha. Forage legumes will not, however, become more widely grown until inexpensive and efficient mechanized methods of harvesting the mature crop are available in order to avoid the high cost of hand labour. Drought and cold tolerance, early maturation and high harvest index may also enhance farmers' interest in forage legumes.

A participatory on-farm research project was started at Tah village, 100 km south of Aleppo, Syria in 1984. The objective was to introduce annual medics (Medicago spp.) as a replacement for fallow in dryland wheat (Triticum durum)/fallow farming systems. About 50 farmers were directly involved in the project while an equal number were passive participants, receiving seed but no technical advice. The project did not attain its original intention of introducing a ley-farming system into Syria. The Syrian Government decided to eliminate fallow – which was to receive medics – in the agricultural planning for 1989–90. An array of profitable crops such as lentil (Lens culinaris), cumin (Cuminum cyminum), sesame (Sesamum indicum) and watermelon (Citrullus lanatus), together with price supports on wheat presented formidable economic competition to the use of pasture on cultivated land. Technical constraints include insufficient farm size, lack of a medic phase in every year, deep ploughing, overgrazing and uncontrolled grazing. The Tah project experience also suggests that feed production projects must include an assessment of how the feed benefits animals and be designed to demonstrate the economic advantages of integrating livestock and crops in dryland farming systems.

Electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD) is used to grow thin epitaxial films on Si(100) wafers. We report on systematic variations of deposition parameters like substrate temperature, substrate dc bias voltage, and gas composition. The structural quality was significantly improved by increasing the substrate temperature from 325 to 500 °C. Simultaneously, compressive lattice strain tends to increase. A negative dc bias voltage resulted in highly disordered films and increased surface roughness due to enhanced ion damage. In contrast positive bias voltages decreased the defect creation by reducing the ion bombardment of the surface during growth. Under so far optimized conditions the remaining disorder is given by two-dimensional, extended defects running parallel to the growth direction and forming grain boundaries with a lateral spacing of 500–700 nm. The single grains are essentially free of one- and two-dimensional defects and show the same orientation as the substrate. By reducing the H2 dilution and adding Ar to the excitation gas the deposition rate increased from 5.3 to 16.2 nm/min. This resulted in inferior structural quality which might be attributed to the reduced etching effect, the enhanced ion bombardment and/or the increased growth rate.

The preparation of μc-Si films from SiH4-H2 mixtures by electron-cyclotron resonance (ECR) CVD at deposition temperatures ≤ 400°C on foreign substrates is reported. Deposition conditions were identified for which Si films with a high degree of crystallinity were grown as was confirmed by Raman spectroscopy. A factorial analysis was carried out, for which the influence of deposition temperature, microwave power, hydrogen dilution and total pressure on film growth were investigated. Samples of optimized crystallinity were prepared in a lowpressure and high-hydrogen dilution regime. In-plane grain sizes were measured by TEM and found to be on the order of 10 - 12 nm. Next to the optimization of crystallinity several sources of impurity contamination during film deposition were identified and eliminated. Intrinsic μc-Si layers could be prepared under these conditions that exhibited a dark conductivity σd of 2 × 10-7 S/cm and photosensitivity σph/σd of 150. It is concluded that ECR CVD is capable of producing intrinsic layers with electronic properties as necessary for use in state-of-the-art n-i-p μc-Si solar cells.

Epitaxial GaN films grown by metal organic vapour phase epitaxy (MOVPE) or gas source molecular beam epitaxy (GSMBE) have opened up new applications in short wavelength photonic devices as well as high-power and high-temperature devices. The large lattice mismatch of 14% between GaN and sapphire, which is frequently used as the substrate, and the different thermal expansion coefficients generally lead to high densities of structural defects. We investigate the defect structure of MOVPE- and GSMBE-grown GaN layers on sapphire by Rutherford backscattering and ion channeling measurements. Channeling along the c-axis revealed χmin-values as low as 1.2% even in samples with dislocation densities in the order of 109 cm−2. Channeling measurements along different crystal planes were performed in order to improve the sensitivity to dechanneling by crystalline defects. Angular yield scans around the c-axis indicate clearly the hexagonal symmetry of the GaN lattice. Dechanneling results were combined with transmission electron microscopy investigations (TEM). The results suggest that the dechanneling-cross-section of edge dislocations is about 4 times larger than the dechannelingcross-section of screw dislocations. screw dislocations.

We analyse by means of transmission electron microscopy (TEM) and atomic force microscopy (AFM) the strain relaxation mechanisms in InGaN layers on GaN as dependent on the In content. At the experimentally given thickness of 100 nm, the layers remain coherently strained, up to an In concentration of 14 %. We show that part of the strain is reduced elastically by formation of hexagonally facetted pinholes. First misfit dislocations are observed to form at pinholes that reach the InGaN/GaN interface. We discuss these results in the framework of the Matthews-Blakeslee model for the critical thickness considering the Peierls force for glide of threading dislocations in the different slip systems of the wurtzite lattice.

The introduction of appropriate crop rotations is known to be beneficial in many farming systems. One feature of rotations is that it takes a valuable length of time for the advantage of the rotation to take effect. In long-term rotation trials, the observations from the same plot over years are correlated; ignoring such correlations may affect the precision of the estimates of rotation effects. We examined five covariance structures between the plot errors over time to assess the effect of correlations on the standard errors of rotation means and rotation x cycle combination (interaction) means on wheat yields using eight years of data from six two-phase rotations with wheat. Based on wheat yield data from the four cycles of the rotations considered, the compound symmetry covariance structure (constant correlation) between plot errors arising over alternate years gave more efficient estimates of rotation means compared with the other four covariance structures.

We report on a comprehensive study of the defect structure in GaN grown on c-oriented sapphire by gas source molecular beam epitaxy and metal organic vapour phase epitaxy. Transmission electron microscopy is used to investigate the defect structures which are dominated by threading dislocations perpendicular to the sapphire surface and stacking faults. Additionally, dislocation densities are determined. For determination of dislocation densities by x-ray diffraction we employ a model that uses the linewidth of x-ray rocking curves for this purpose. Finally, Rutherford backscattering spectrometry is performed to complement the structural investigation.