Aspecten van ammoniak-emissie, monstername en -verwerking van stromest en drijfmest op bedrijven met scharrelvarkens

Two free-range pig farms are examined on their nitrogen balance. In a laboratory experiment the influence of straw bedding on the ammonia emission is investigated. Also the heterogenity of the samples is examine

Proton conductivity in mixed b-site doped perovskite oxide BaZr0.5In0.25Yb0.25O3-delta

A wet chemical route was used to prepare the oxygen deficient codoped perovskite oxide BaZr0.5In0.25Yb0.25O3−. Analysis of X-ray powder diffraction data showed that the sample belongs to the cubic crystal system with space group Pmm. Dynamic thermogravimetric (TG) analysis confirmed complete filling of oxygen vacancies (V) by protonic defects (OH) during the hydration process. The proton conductivity was investigated by impedance spectroscopy. The bulk and total conductivities of prehydrated BaZr0.5In0.25Yb0.25O3− were found to be 8.5 710−4 and 2.2 710−5 S cm−1, respectively, at 300\ub0C. The total conductivity in the codoped perovskite oxide was higher compared to that of the respective single doped perovskite oxides with the same doping level. The bulk and grain-boundary mobility and diffusion coefficients of protons were calculated at 200\ub0C using impedance and TG data to obtain the conductivity and proton concentration, respectively. The high bulk diffusivity (2.3 710−7 cm2 s−1) was obtained which indicates that the protons are more free to move in the heavily doped matrix compared to the lightly doped systems where trapping of protons occurs

Improved proton conductivity in spark-plasma sintered dense ceramic BaZr0.5In0.5O3-delta

Spark-plasma sintering method was used to prepare dense proton conducting perovskite oxide BaZr0.5In0.5O3-delta. Analysis of X-ray powder diffraction data showed that the sample adopt the cubic crystal structure having the space group Pm3m. Thermogravimetric analysis of prehydrated samples showed significant mass losses beyond 300 degrees C due to loss of protons as water vapor. Scanning electron microscope images show that the grain size of the spark-plasma sintered dense sample was smaller than that of solid-state sintered porous sample. The highest total proton conductivity (2 X 10(-3) S cm(-1) at 450 degrees C) was found for dense spark-plasma sintered sample under wet H-2 than the samples prepared by other routes

Influence of adrenodemedullation on ß2- and ß3-adrenoceptors mediating relaxation of oesophageal smooth muscle of spontaneously hypertensive rats

1 In oesophageal smooth muscle strips from spontaneously hypertensive rats (SHR) of 8-10 and 22-24 weeks of age, respectively, beta-adrenoceptor-mediated relaxation was investigated, by use of the beta-agonists, (-)-isoprenaline and fenoterol (both in the absence and presence of the beta(2)-selective antagonist ICI 118,551) and the selective beta(3)-agonist, BRL 37,344.2 In preparation from 8-10 week SHR, (-)-isoprenaline- and fenoterol-induced concentration-response curves (CRCs) were hardly antagonized by ICI 118,551 at concentrations up to 1 mu M, indicating only a minor contribution of beta(2)-adrenoceptors. pA(2)-values for ICI 118,551 of 5.30 ((-)-isoprenaline as agonist) and 5.46 (fenoterol as agonist), estimated from the shifts at the highest (10-100 mu M) antagonist concentrations, are consistent with affinity at a beta(3)-adrenoceptor, similar to that in Wistar rat oesophageal smooth muscle.3 In 8-10 week SHR, adrenodemedullated at 4 weeks of age (SHR-ADM4) the potency of fenoterol was markedly increased and CRCs were shallow. In addition, ICI 118,551 (0.1 mu M) now produced a clear rightward shift accompanied by a steepening of the CRC. A marked further shift was observed only at 100 mu M of the antagonist. The data are compatible with the involvement of both beta(2)- and beta(3)-adrenoceptors.4 In 22-24 week animals, the same differences between SHR and SHR-ADM4 were observed with fenoterol as in 8-10 week animals, though beta-adrenoceptor responsiveness was slightly decreased. The potency of ICI 118,551 at beta(3)-adrenoceptors (pA(2) = 5.11) was significantly different from the pA(2) value of 5.46 obtained with the younger animals.5 Responses to the beta(3)-adrenoceptor agonist, BRL 37,344, were similar in Wistar rat and SHR preparations, In 8-10 week SHR, a small decrease in the maximal response was observed, which in animals of 22-24 weeks of age was accompanied by a small decrease in the pEC(50) value as well.</p

'All that glisters...' Prehistoric gold (pickings) from the Netherlands

Gold is a rarity in archaeological research, and its prehistoric presence is often used to infer the existence of persons of extraordinary standing (Warmenbol 2004: 208 & 219). It therefore is a fitting topic to congratulate a colleague that we hold in extraordinary regard; our questions to Eugène on the Later Prehistoric archaeology and bronze artefacts of Belgium were never posed in vain and his constructive comments on our publications never missed their mark. In his honor, we present an overview of the prehistoric gold from the Late Neolithic up to the Early Iron Age from the Netherlands – another case in point of how we could build on foundations put in place by Eugène (esp. Warmenbol 1989: 509; Warmenbol 2004). An open access dataset comprising the full descriptions for the individual objects can be found here: https://doi.org/10.34894/8SQK5F. In this contribution we have discussed the few but notable gold finds datable from the Late Neolithic up to Early Iron Age from the Netherlands. Despite being low in numbers, a few trends come to the fore: both around 2300-2000 BCE and 1600-1400 BCE, gold ornaments are used in funerary context as markers of a special social standing, possibly related to interregional contacts and/or martial identities. The position of gold ornaments in both horizon 1 and 2 suggest that these are head-decorations, possible wrapped around locks or breads of hair, with the possible exception of the diadem (or neckring?) of Ede – Bennekom. In horizon 3, gold ornaments are no longer placed solely in graves, but – akin to their bronze counterparts – also deposited in wetland locations in the landscape. In this period, their association to weaponry (apart obviously of the gold inlay of the Oss sword; Van der Vaart-Verschoof 2017a: 122-124) appears to be lost, and small-diameter gold and gilded rings of unknown original usage (nose? ear? hair?) are added to cremated remains in urnfield period ceramic vessels. Their scarce occurrence in such contexts, suggests that gold had lost nothing of its exclusivity over the ages. We can only hope that Eugène’s work on prehistoric metalwork will similarly continue to glister upon his retirement

Effect of co-doping on proton conductivity in perovskite oxides BaZr0.9In0.05M0.05O3−δ (M = Yb3+ or Ga3+)

BaZr0.9In0.05M0.05O3-d (M ¼ Ga3+ or Yb3+) has been prepared by solid-statesynthesis route. Rietveld analysis of neutron powder diffraction data on as-prepared samples showed that both samples crystallise in the cubic space group Pm-3m. Scanning electron microscopy analysis showed that the grains intheBaZr0.9In0.05Ga0.05O3-d sample were larger than the BaZr0.9In0.05Yb0.05O3-d sample. Dynamic thermogravimetric analysis indicates that the proton concentration was higher inpre-hydrated BaZr0.9In0.05Ga0.05O3-d sample (40%of theoretical)than that of BaZr0.9In0.05Yb0.05O3-d sample (28%oftheoretical).Proton conductivity was studied on pre-hydrated samples(under both dry and wetAr atmospheres).The bulk proton conductivities of the heating cycle of pre-hydrated BaZr0.9In0.05M0.05O3-d (M ¼ Ga3+ or Yb3+) samples were 2.1 * 10-5 S cm-1 and 1.9 * 10-4 S cm-1 at 350C, respectively.The effect of co-doping onproton conductivity was investigated and the results are compared with single doped systems e.g. BaZr0.9M0.1O3-d (M=Ga3+, In3+ or Yb3+) samples

Revisiting the Redox Properties of Hydrous Iridium Oxide Films in the Context of Oxygen Evolution

The electrochemistry of hydrous iridium oxide films (HIROF) is revisited. Cyclic voltammograms of HIROFs display two reversible redox couples commonly assigned to the Ir(III)/Ir(IV) and Ir(IV)/Ir(V) transitions, respectively. However, compared to the first, the second redox couple has significantly less charge associated to it. This effect is interpreted as partial oxidation of Ir(IV) as limited by nearest neighbor repulsion of resulting Ir(V) sites. Thus, the redox process is divided into two steps: one preceding and one overlapping the oxygen evolution reaction (OER). Here, the ``super-nernstian'' pH dependence of the redox processes in the HIROF is used to expose how pH controls the overpotential for oxygen evolution, as evidenced by the complementary increased formation of Ir(V) oxide. A recently formulated binuclear mechanism for the OER is employed to illustrate how hydrogen bonding may suppress the OER, thus implicitly favoring Ir(V) oxide formation above the thermodynamic onset potential for the OER at low pH