Heterogeneous Exchange of Mixed Precipitates. [Agl + PbI2] solid in KI Solution

The heterogeneous exchange process of mixed AgI + PbI2 precipitates with iodide from the KI solution was studied using 1311. The systems under examination were prepared in statu nascendi at 293 K. Radiometrically determined solubility, differential thermal analysis and X-o:-ay diffraction analysis data were compared with radi:oanalytical results of the heterogeneous exchange processes. The results show ,strong mutual dependence of the metal halides present throughout the exchange process. The quantitative analysis of radiometric data indicates the specific influence of lead iodide onto silver iodide particles during the Ostwald\u27s ripening process

Hydrodynamic Effects of Debris Blockage and Scour on Masonry Bridges: Towards Experimental Modelling

This is the author accepted manuscript. The final version is available from CRC Press via the DOI in this record8th International Conference on Scour and Erosion, 12-15 September 2016, Oxford, UKThis paper describes the preliminary stage of an ongoing project investigating the hydrodynamic effects of debris blockage at masonry bridges. Debris blockage is cited as one of the primary causes of bridge failures in the UK and around the world. Masonry bridges, many of which are valuable historical assets, are particularly vulnerable to debris blockage due to their short spans and low clearance. This paper presents work done as part of the first phase of the project involving experimental research to understand the scientific relationships between debris characteristics and flow conditions. The study, being carried out at Centre for Water Systems at University of Exeter, utilizes a 0.6m-wide and 10m-long flume to run hydraulic experiments in order to characterize the impact of debris blockage on flow hydrodynamics, scour, and hydrodynamic pressures and forces at masonry bridges. This paper outlines the design of the experimental setup and the reasoning behind the choices for preliminary experimental parameters. The experiments are to include testing of bridge models and various 3D-printed debris shapes under realistic flow conditions. Geometry of the bridge and debris mod-els are kept approximately similar to prototype conditions, with hydraulic conditions of the experiments de-signed to the degree that experimental constraints allow based on Froude similarity. Velocities, scour and hy-drodynamic pressures are measured using an Acoustic Doppler Velocimeter, echo-sounding concept and pres-sure sensors, respectively. Preliminary results indicate that the designed experiments have the potential to en-hance our understanding of the hydrodynamic effects of debris blockage.The research presented in this paper was supported by funding from the UK’s Engineering and Physical Sciences Research Council (EPSRC) under grant EP/M017354/1. The authors are grateful to project partners for their support, particularly Devon County Council and Network Rail for providing useful prototype data

Radiosensitivity of sunflower inbred lines to mutagenesis

For much of the past century, mutagenesis has gained popularity in plant genetics research as a means of inducing novel genetic variation. Induced mutations have been applied for the past 40 years to produce mutant cultivars in sunflower by changing plant characteristics that significantly increase plant yield and quality. The present study is focused on generating baseline data to elucidate the role of genotypic differences in the response of sunflower to induced mutagenesis with the aim of expanding the applicability of the use of induced mutant stocks in the genetic improvement of the crop and in its functional genomics. The strategy adopted was to estimate the optimal treatment conditions (doses of mutagens) through relating the extent of damage in seedling progeny to the exposure levels of the initiating propagates to mutagens. Seeds of fifteen elite sunflower genotypes of commonly used as breeding stocks and grown on commercial scales were treated with a range of mutagens: gamma rays (γ rays); fast neutrons and with ethyl-methane-sulphonate (EMS) at different treatment doses. The three mutagenic agents affected seedling height, reducing it with increasing dosage. Based on the mutagen damage on seedling height, the 50% and 30% damage indices (D50 and D30, respectively) were estimated for the 15 sunflower genotypes for the three mutagens. The D50 (D30) values for the sunflower lines ranged from 120 to 325 Gy (5 to 207 Gy) for gamma irradiation; 9 to 21 Gy (0.1 to 10 Gy) for fast neutrons and 0.69 to 1.55% (0.01 to 0.68%) concentration of EMS

Selective Adsorption of Ionic Species Using Macroporous Monodispersed Polyethylene Glycol Diacrylate/Acrylic Acid Microgels with Tunable Negative Charge

Monodispersed polyethylene glycol diacrylate (PEGDA)/acrylic acid (AA) microgels with a tuneable negative charge and macroporous internal structure have been produced using a Lego-inspired droplet microfluidic device. The surface charge of microgels was controlled by changing the content of AA in the monomer mixture from zero (for noncharged PEGDA beads) to 4 wt%. The macroporosity of the polymer matrix was introduced by adding 20 wt% of 600-MW polyethylene glycol (PEG) as a porogen material into the monomer mixture. The porogen was successfully leached out with acetone after UV-crosslinking, which resulted in micron-sized cylindrical pores with crater-like morphology, uniformly arranged on the microgel surface. Negatively charged PEGDA/AA beads showed improved adsorption capacity towards positively charged organic dyes (methylene blue and rhodamine B) compared to neutral PEGDA beads and high repulsion of negatively charged dye molecules (methyl orange and congo red). Macroporous microgels showed better adsorption properties than nonporous beads, with a maximum adsorption capacity towards methylene blue of 45 mg/g for macroporous PEGDA/AA microgels at pH 8.6, as compared to 23 mg/g for nonporous PEGDA/AA microgels at the same pH. More than 98% of Cu(II) ions were removed from 50 ppm solution at pH 6.7 using 2.7 mg/mL of macroporous PEGDA/AA microgel. The adsorption of cationic species was significantly improved when pH was increased from 3 to 9 due to a higher degree of ionization of AA monomeric units in the polymer network. The synthesized copolymer beads can be used in drug delivery to achieve improved loading capacity of positively charged therapeutic agents and in tissue engineering, where a negative charge of scaffolds coupled with porous structure can help to achieve improved permeability of high-molecular-weight metabolites and nutrients, and anti-fouling activity against negatively charged species

Probing Primordial and Pre-Galactic Lithium with High Velocity Clouds

The pre-Galactic abundance of lithium offers a unique window into non-thermal cosmological processes. The primordial Li abundance is guaranteed to be present and probes big bang nucleosynthesis (BBN), while an additional Li component is likely to have been produced by cosmic rays accelerated in large scale structure formation. Pre-Galactic Li currently can only be observed in low metallicity Galactic halo stars, but abundance measurements are plagued with systematic uncertainties due to modeling of stellar atmospheres and convection. We propose a new site for measuring pre-Galactic Li: low-metallicity, high-velocity clouds (HVCs) which are likely to be extragalactic gas accreted onto the Milky Way, and which already have been found to have deuterium abundances consistent with primordial. A Li observation in such an HVC would provide the first extragalactic Li measurement, and could shed new light on the apparent discrepancy between BBN predictions and halo star Li abundance determinations. Furthermore, HVC Li could at the same time test for the presence of non-primordial Li due to cosmic rays. The observability of elemental and isotopic Li abundances is discussed, and candidate sites identified.Comment: 10 pages, AASTe

Insulin responses to acute glucose infusions in Buša and Holstein-Friesian cattle breed during the peripartum period: Comparative study

The aim of this study was to compare insulin responsevness to acute glucose infusion in cows of Holstein Friesian (HF) and Buša breeds during the peripartal period. Eight cows per each group (HF and Buša), were chosen. At day 7 prior to calving (ante partum) and day 14 after calving (post partum) animals were subjected to a glucose tolerance test (GTT). Blood samples were taken immediately before infusion and 15, 30, 60, 120 and 180 min thereafter. Glucose and insulin concentrations were measured in each blood sample, while BHBA and NEFA were measured only in samples taken before the infusion. QUICKY an indicator of insulin resistance in cows was calculated. Basal glycemia did not significantly differ between the breeds. Basal insulinemia was significantly higher in Buša than in HF cows in both examined periods (p<0.001, respectively). Basal NEFA levels tended (p=0.06) to be higher in Buša cows compared with those of HF ante partum, and was significantly higher (p<0.001) post partum. Basal BHBA was significantly lower in Buša than HF cows in both examined periods (p<0.01; p<0.001). QUICKI was significantly lower in Buša compared to HF cows both ante partum and post partum periods (p<0.001, respectively). Glycemia determined during GTT were higher in Buša than HF cows, both ante partum and post partum, but significantly starting from minute 15 ante partum i.e. minute 30 post partum. Insulinemia determined during GTT was significantly lower at min 15, and significantly higher starting from min 90 in Buša than HF cows, both ante partum and post partum. Results obtained in this study indicate on difference in insulin responsevness to acute glucose infusion between the examined breeds, which is probably a consequence of the difference in the degree of negative energy balance rather than of selection on high milk production. Namely, decreased insulin tissues sensitivity and decreased insulin responsiveness in Buša compared to HF cows is probably the consequence of inadequate energy intake from alimentary sources which leads to enhanced usage of energy from body reserves. [Projekat Ministarstva nauke Republike Srbije, br. 46002

Scour and hydrodynamic effects of debris blockage at masonry bridges: insights from experimental and numerical modelling

The final version is available from IAHR via the URL in this record.This paper describes preliminary results of a project investigating the scour and hydrodynamic effects of debris blockage at masonry bridges. Debris blockage, which is often cited as one of the primary causes of bridge failures in the UK and around the world, results in a larger obstruction to the flow leading to increased flow velocities, scour and hydrodynamic forces, compared to the conditions without debris. This, in turn, can affect the structural stability of bridges, for example, by undermining their foundations. Masonry bridges, many of which are valuable historical assets, are particularly vulnerable to debris blockage due to their short spans and low clearance. The reported study, being undertaken at the Centre for Water Systems at the University of Exeter, has two main phases: (i) laboratory experiments and (ii) CFD simulations. In the first phase, a 0.6m-wide and 10m-long flume is utilized to study the flow hydrodynamics and scour associated with pier/bridge models in several reference scenarios. The geometry of the pier/bridge and debris models are kept approximately similar to prototype conditions, with hydraulic conditions of the experiments designed to the degree that laboratory constraints allow to maintain Froude similarity. Velocities and scour are measured via an acoustic Doppler velocimeter and echo-sounding concept. Experimental results are used to calibrate and validate CFD models which can later enable simulation of more complicated scenarios. This paper will report these preliminary results from both experimental and CFD phases. Preliminary experimental results highlight the significance of debris existence in enhancing scour due to increasing flow downward velocities. Preliminary results from CFD modelling also show good agreement with experimental results.The research presented in this paper was supported by funding from the UK’s Engineering and Physical Sciences Research Council (EPSRC) under grant EP/M017354/1

Porous structure and fluid partitioning in polyethylene cores from 3D X-ray microtomoC12017

Abstract Using oil-wet polyethylene core models, we present the development of robust throat finding techniques for the extraction, from X-ray microtomographic images, of a pore network description of porous media having porosity up to 50%. Measurements of volume, surface area, shape factor, and principal diameters are extracted for pores and area, shape factor and principal diameters for throats. We also present results on the partitioning of wetting and non-wetting phases in the pore space at fixed volume increments of the injected fluid during a complete cycle of drainage and imbibition. We compare these results with fixed fractional flow injection, where wetting and non-wetting phase are simultaneously injected at fixed volume ratio. Finally we demonstrate the ability to differentiate three fluid phases (oil, water, air) in the pore space

New insights into body condition score and its association with fatty liver in Holstein dairy cows

The aim of this study was to estimate the association between body condition and fatty liver in high-yielding dairy cows. One hundred dry Holstein cows were selected. Cows were scored once for body condition during the dry period, puerperium and month 2 of lactation, according to the system provided by Elanco Animal Health Buletin Al 8478. Body condition loss was determined as marked if loss was over 0.7 points between two consecutive phases of cycles and over 1.5 points between puerperium and month 2 of lactation. Liver tissue samples were taken 12 d after calving and tested for lipid content. 50% of cows had mild (3.92 +/- 3.33% fat), 33% moderate (19.28 +/- 5.18% fat), and 17% severe fatty liver (36.21 +/- 4.55% fat). The mean body condition scores were 3.79 +/- 0.55 (dry period), 3.18 +/- 0.34 (puerperium) and 2.90 +/- 0.29 (month 2 of lactation). Marked body condition loss from the dry period to puerperium had 38% of cows, 20% from dry period to month 2 of lactation and 8% from puerperium to month 2 of lactation. Body condition scores out of the physiological range had 39% dry cows, 49 % cows in puerperium and 9% cows at month 2 of lactation. After dividing cows into groups according to fatty liver degree, it was shown that only cows with severe fatty liver were obese during the dry period and that 76.47% of cows from this group had marked condition loss from the dry period to puerperium, 47.06% from dry period to month 2 of lactation and 23.53% from puerperium to month 2 of lactation. These indicate that in cows with severe fatty liver lipomobilisation is intensive and starts around calving, before milk production enhacement. Our results indicate a strong association between body condition and fatty liver in cows, which can be estimated only when body condition is analyzed in details. Besides, our results clearly indicate that body condition is not the only etiological factor that leads to fatty liver in dairy cows

DISLOKACIJA SIRIŠTA KOD GOVEDA

Promena položaja je najvažnija bolest sirišta goveda. U zapatima visoko-mlečnihkrava pojavlјivanje bolesti varira u širokom rasponu od 1 do 18 posto, kod krava istočno-frizijske rase dislokacija sirišta je dijagnostikovana u 1 do 3 posto životinja, a uzapatima krava holštajn rase ustanovlјena je kod 5 do 18 posto životinja. Kod kravasimentalske rase promena pol