Gasvormige emissies en fijnstof uit konijnenstallen met mestopslag onder de welzijnshokken = Gasesous emissions and fine dust from rabbit housing systems

In this study emissions of ammonia and fine dust (PM2,5 and PM10) from rabbit housing systems were determined. In addition, emissions of greenhouse gases and odour were determined

Naar een jaarrond-emissie van ammoniak uit melkveestallen

In dit rapport wordt een overzicht gegeven van de onderzoeksresultaten op het gebied van ammoniakemissie vanuit diverse typen melkveestallen in Nederland

The nutritive value of black soldier fly larvae reared on common organic waste streams in Kenya

Open Access JournalIn Africa, livestock production currently accounts for about 30% of the gross value of agricultural production. However, production is struggling to keep up with the demands of expanding human populations, the rise in urbanization and the associated shifts in diet habits. High costs of feed prevent the livestock sector from thriving and to meet the rising demand. Insects have been identified as potential alternatives to the conventionally used protein sources in livestock feed due to their rich nutrients content and the fact that they can be reared on organic side streams. Substrates derived from organic by-products are suitable for industrial large-scale production of insect meal. Thus, a holistic comparison of the nutritive value of Black Soldier Fly larvae (BSFL) reared on three different organic substrates, i.e. chicken manure (CM), brewers’ spent grain (SG) and kitchen waste (KW), was conducted. BSFL samples reared on every substrate were collected for chemical analysis after the feeding process. Five-hundred (500) neonatal BSFL were placed in 23 × 15 cm metallic trays on the respective substrates for a period of 3–4 weeks at 28 ± 2 °C and 65 ± 5% relative humidity. The larvae were harvested when the prepupal stage was reached using a 5 mm mesh size sieve. A sample of 200 grams prepupae was taken from each replicate and pooled for every substrate and then frozen at −20 °C for chemical analysis. Samples of BSFL and substrates were analyzed for dry matter (DM), crude protein (CP), ether extracts (EE), ash, acid detergent fibre (ADF), neutral detergent fibre (NDF), amino acids (AA), fatty acids (FA), vitamins, flavonoids, minerals and aflatoxins. The data were then subjected to analysis of variance (ANOVA) using general linear model procedure. BSFL differed in terms of nutrient composition depending on the organic substrates they were reared on. CP, EE, minerals, amino acids, ADF and NDF but not vitamins were affected by the different rearing substrates. BSFL fed on different substrates exhibited different accumulation patterns of minerals, with CM resulting in the largest turnover of minerals. Low concentrations of heavy metals (cadmium and lead) were detected in the BSFL, but no traces of aflatoxins were found. In conclusion, it is possible to take advantage of the readily available organic waste streams in Kenya to produce nutrient-rich BSFL-derived feed

Fijnstofemissie uit stallen: nertsen = Dust emission from animal houses: minks

In this study emissions of fine dust (PM10 and PM2.5) from houses for minks were determined. In addition, emissions of ammonia, greenhouse gases and odour were determined

Metal artefacts severely hamper magnetic resonance imaging of the rotator cuff tendons after rotator cuff repair with titanium suture anchors

BackgroundThe rate of retear after rotator cuff surgery is 17%. Magnetic resonance imaging (MRI) scans are used for confirmative diagnosis of retear. However, because of the presence of titanium suture anchors, metal artefacts on the MRI are common. The present study evaluated the diagnostic value of MRI after rotator cuff tendon surgery with respect to assessing the integrity as well as the degeneration and atrophy of the rotator cuff tendons when titanium anchors are in place.MethodsTwenty patients who underwent revision surgery of the rotator cuff as a result of a clinically suspected retear between 2013 and 2015 were included. The MRI scans of these patients were retrospectively analyzed by four specialized shoulder surgeons and compared with intra-operative findings (gold standard). Sensitivity and interobserver agreement among the surgeons in assessing retears as well as the Goutallier and Warner classification were examined.ResultsIn 36% (range 15% to 50%) of the pre-operative MRI scans, the observers could not review the rotator cuff tendons. When the rotator cuff tendons were assessable, a diagnostic accuracy with a mean sensitivity of 0.84 (0.70 to 1.0) across the surgeons was found, with poor interobserver agreement (kappa = 0.12).ConclusionsMetal artefacts prevented accurate diagnosis from MRI scans of rotator cuff retear in 36% of the patients studied.</jats:sec

Structural tale of two novel (Cr, Mn)C carbides in steel

Chromium (Cr), manganese (Mn) and carbon (C) are well known alloying elements used in technologically important alloy steels and advanced high strength steels. It is known that binary CrCx and MnCx carbides can be formed in steels, but in this study we reveal for the first time that Cr and Mn were found combined in novel ternary cementite type (Cr, Mn)C carbides. Electron diffraction experiments showed that Cr, Mn and C formed two distinct carbide phases possessing orthorhombic and monoclinic crystal structures. Density functional theory calculations were performed on these phases and excellent agreement was found between calculations and experiments on the lattice parameters and relative atomic positions. The calculations showed that the combination of Mn and Cr resulted in a very high thermodynamic stability of the (Cr, Mn)C carbides, and that local structural relaxations are associated with carbon additions. Possible implications of these ternary carbides for novel applications in steel design and manufacturing are discussed

Thermal stability and electronic and magnetic properties of atomically thin 2D transition metal oxides

© The Author(s) 2019. Two-dimensional (2D) transition metal oxides (TMOs) are an emerging class of nanomaterials. Using density functional theory and ab initio molecular dynamics (AIMD) simulations, we carried out a systematic study of atomically thin metal oxide phases with compositions MO, M2O3, and MO2, for transition metal elements Sc, Ti, V, Cr, and Mn. We identified nine thermally stable structures that may be realized as free-standing nanosheets: hexagonal h-Sc2O3, h-V2O3, and h-Mn2O3; hexagonal t-VO, t-CrO, and t-MnO; and square sq-TiO, sq-VO, and sq-MnO. The t-MO phases are novel hexagonal structures which emerged naturally from phase transformations observed during AIMD simulations. The 2D TMOs were found to exhibit a wide range of remarkable electronic and magnetic properties, indicating that they are bright candidates for electronic and spintronic applications. Most exceptional in this regard is h-V2O3, that is the only phase that has been experimentally realized so far, and was found to be a ferromagnetic half-metal with Dirac-cone-like bands.This project is financially supported by the Dutch science foundation NWO via a VIDI grant (grant no. 723.012.006) and by the European Research Council through an ERC Consolidator Grant (grant no. 683076). This work was carried out on the Dutch national e-infrastructure with the support of SURF Cooperative and NWO Rekentijd (grant no. 16905)