Mass Deposition Research Articles

In situ Preservation Solutions for Deposited Iron Age Human Bones in Alken Enge, Denmark

The rich mass deposition of Iron Age human bone material from the Danish site, Alken Enge, is extraordinary not only from an archaeological perspective but also from a preservation point of view. The main find is situated in a waterlogged, anoxic environment which provides excellent preservation conditions and therefore enables in situ preservation of the human bones. However, major differences in local environmental conditions challenge an in situ preservation of the entire site area as parts of the bone material presently deteriorate. In this paper, a multi-proxy environmental monitoring approach is used to document threats and to suggest the best preservation solution for the archaeological finds, whether in or ex situ.

Effect of the interplanetary magnetic field orientation and intensity in the mass and energy deposition on the Hermean surface

The aim of the present study is to simulate the interaction between the solar wind and the Hermean magnetosphere. We use the MHD code PLUTO in spherical coordinates with an axisymmetric multipolar expansion of the Hermean magnetic field, to perform a set of simulations with different interplanetary magnetic field orientations and intensities. We fix the hydrodynamic parameters of the solar wind to study the distortions driven by the interplanetary magnetic field in the topology of the Hermean magnetosphere, leading to variations of the mass and energy deposition distributions, the integrated mass deposition, the oval aperture, the area covered by open magnetic field lines and the regions of efficient particle sputtering on the planet surface. The simulations show a correlation between the reconnection regions and the local maxima of plasma inflow and energy deposition on the planet surface.

Abstracts from The Aerosol Society Drug Delivery to the Lungs 26 Edinburgh International Conference Centre Edinburgh, Scotland, UK December 9-11, 2015.

Abstracts from The Aerosol Society Drug Delivery to the Lungs 26 Edinburgh International Conference Centre Edinburgh, Scotland, UK December 9-11, 2015.

Lithium granule ablation and penetration during ELM pacing experiments at DIII-D

At DIII-D, lithium granules were radially injected into the plasma at the outer midplane to trigger and pace edge localized modes (ELMs). Granules ranging in size from 300 to 1000 microns were horizontally launched into H-mode discharges with velocities near 100m/s, and granule to granule injection frequencies less than 500Hz. While the smaller granules were only successful in triggering ELMs approximately 20% of the time, the larger granules regularly demonstrated ELM triggering efficiencies of greater than 80%. A fast visible camera looking along the axis of injection observed the ablation of the lithium granules. The duration of ablation was used as a benchmark for a neutral gas shielding calculation, and approximated the ablation rate and mass deposition location for the various size granules, using measured edge plasma profiles as inputs. This calculation suggests that the low triggering efficiency of the smaller granules is due to the inability of these granules to traverse the steep edge pressure gradient region and reach the top of the pedestal prior to full ablation.

Sea salt aerosol deposition in the coastal zone: A large eddy simulation study

Inland deposition of sea salt aerosol (SSA) particles emitted over the ocean is studied via numerical and theoretical models. The focus is on the large particles that contribute most to the total mass deposition. Large eddy simulations of idealized sea wind are used to investigate the development of the particle plume over land for different particle sizes and to validate some of the assumptions in the theoretical model. An existing theoretical modeling framework for particle dispersion in the atmospheric boundary layer is adapted to the problem of SSA deposition and it is shown to be adequate for the large particles of interest here. The decay of monodisperse SSA particle deposition flux with distance from the shoreline is shown to have a power-law behavior far from the shoreline. A complete model for predicting mass deposition as a function of distance is formulated and shown to present reasonable agreement with existing data.

Studies of the CO oxidation kinetic regularities on Cu–Co–Fe oxide catalysts, bulk and deposited on the carbon nanotubes

The effect of catalysts of the carbon nanotubes synthesis and of the technology of a Cu–Co–Fe active oxide mass deposition on the kinetic regularities of the CO oxidation reaction has been studied. It has been shown that the experimental data on both catalysts, bulk Cu–Co–Fe and deposited onto carbon nanotubes, agree with the Eley–Readil kinetic scheme. Based on the suggested mechanism, the effective reaction rate constants have been calculated by various methods. It has been shown that the use of Cu–Co–Fe catalysts deposited on carbon nanotubes offers considerable promise.

Propagation of nitrogen gas in a liquid helium cooled vacuum tube following sudden vacuum loss – Part II: Analysis of the propagation speed

The propagation of near-atmospheric nitrogen gas entering a liquid helium (LHe) cooled vacuum tube following an accidental loss of vacuum will be strongly influenced by condensation of the gas on the tube wall. Our previous experimental study revealed that in presence of condensation, the propagation speed of the gas front decreases nearly exponentially as the front advances in the tube. In the present paper, the exponential decrease is studied semi-analytically. We reduce the analytical model of the front speed, using assumptions, to show its derivative in the direction of propagation to be proportional to the mass deposition rate near the front. The deposition rate is then obtained at discreet locations along the tube from the condensation heat transfer rate at these locations. We find the deposition rate to diminish nearly exponentially along the tube so that the spatial derivative of the speed will show the same effect. In this special case, the front speed will also fall exponentially along the tube. Within the experimental and procedural uncertainty, the exponential decay length-scale of the mass deposition rate also agrees reasonably with the empirically determined exponential decay length-scale of the propagation speed.

Variability of dust mass concentrations and deposition rates under different weather conditions in Cele Oasis, southern Tarim Basin

Sand and dust invasions are a serious issue for oases; therefore, understanding the characteristics of dust concentrations, deposition rates, and influencing factors, under a variety of differing dust weather intensities, is important for the prevention of dust disasters. Field observations made in the Cele Oasis, in the southern Tarim Basin, indicated that the atmospheric levels of suspended mineral dust were far above those of other regions in China, and very close to Sahelian belt. The mass concentrations of TSP (total suspended particulates) and PM10 (particles with aerodynamical diameter <10 μm) span three orders of magnitude under different intensities of dust weathers. The TSP and PM10 concentrations exceeded the second grid of China’s National Standard 66.0- and 20.8-fold during dust storms, 35.8- and 9.2-fold during blowing sand, and 17.8- and 3.8-fold during floating dust. The dust accumulation caused by dust storms, blowing sand, and floating dust accounted for 40.16, 31.57, and 28.27 % of the total accumulation, respectively, but the blowing sand and floating dust had almost the same average deposition rate, which was 37 % less than that of dust storms. Winds blowing from the WSW, W, WNW, and NW brought more dust into the oasis than other directions. The correlation analysis between the dust concentrations, deposition rates and meteorological factors revealed that the oasis microclimate effect plays an important role in enhancing dust deposition during blowing sand and floating dust days. The hygroscopic growth of particles, in particular, is most likely the main mechanism for enhancing deposition.

A non-lethal biopsy technique for sampling subcutaneous adipose tissue of small and medium-sized birds

Analysis of fatty acids from adipose tissue can provide important information about the physiological and nutritional condition of birds. However, non-lethal biopsy procedures and their potential negative effects on small and medium-sized birds have not been adequately assessed. We developed a biopsy procedure for collecting small amounts of adipose tissue from the furcular area of small and medium-sized birds (13–62 g) without adverse effects. The biopsy procedure was performed on Dunlins (Calidris alpina), a medium-sized migratory shorebird, and small hybrid songbirds (European Goldfinch [Carduelis carduelis] × Atlantic Canary [Serinus canaria]). The biopsy involved making a skin incision 2–3 mm long on one side of the furcular region to collect 2–16 mg of adipose tissue. All birds were monitored for 2 weeks after biopsies to examine potential effects of the procedure on body mass, visible fat deposition, time for wound healing, hematocrit levels, total white blood cell counts, and heterophil:lymphocyte ratios. Visible scars were apparent for 10 d for hybrids and 6 d for Dunlins, with no evidence of infection or abnormal scar tissue formation. Body mass of songbirds did not differ before and after the biopsy, but Dunlins increased body mass and visible fat deposition after biopsy. The collection of adipose tissue in the furcular region was performed only for birds with fat scores ≥2, and the tissue collected never represented more than 0.07% of a bird's body mass; we recommend both these values to avoid any possible unknown negative effects. Our non-lethal biopsy technique is relatively simple to perform, and we recommend it as an alternative to lethal methods for sampling adipose tissue in studies of wild and captive birds. Una técnica no letal de biopsia para el muestreo de tejido adiposo subcutáneo en aves de tamaño pequeño y mediano El análisis de ácidos grasos a partir de tejido adiposo puede proveer información importante sobre la condición fisiológica y nutricional de las aves. Sin embargo, no existen estudios sobre el impacto negativo de procedimientos de biopsias no letales sobre aves de pequeño y mediano tamaño. Desarrollamos un procedimiento para colectar pequeñas cantidades de tejido adiposo sin efectos adversos, del área de la fúrcula de aves de tamaño pequeño y mediano (13–62 g). Realizamos la biopsia a Caidris alpina, un ave playera migratoria de tamaño mediano, y un ave pequeña hibrido entre Carduelis carduelis y Serinus canaria. La biopsia requiere realizar una incisión en la piel de aproximadamente 2–3mm de longitud en uno de los lados de la región de la fúrcula, con el fin de colectar 2–16 mg de tejido adiposo. Todas las aves fueron monitoreadas por dos semanas después de la biopsia con el fin de examinar efectos potenciales del procedimiento sobre la masa corporal, la deposición visible de grasa, tiempo de curación de la herida, niveles de hematocrito, conteos totales de glóbulos blancos y tasas heterófilos:linfocitos. Las cicatrices visibles fueron notorias durante 10 días en los híbridos y 6 días en Calidris alpina, sin ninguna evidencia de infección o formación anormal de tejido cicatrizante. La masa corporal de los híbridos no cambio entre antes y después de la biopsia, pero Calidris alpina incrementó en masa corporal y la deposición de grasa visible después de la biopsia. La colección de tejido adiposo en la región de la fúrcula fue realizada solamente en aves con puntuaciones de grasa ≥ 2 y el tejido colectado nunca fue superior al 0.07% de la masa corporal del ave. Recomendamos que se sigan estos dos requerimientos para evitar cualquier posible efecto negativo en las aves. Nuestra técnica no letal de biopsia es relativamente simple de realizar y la recomendamos como una alternativa a métodos letales para colectar tejido adiposo para estudios de aves silvestres y en cautiverio.

Investigation of subsequent deposit growth on pre‐existing lubricant deposits: a substitutional growth model

AbstractThe Penn State Micro‐Oxidation (PSMO) test was used in an inverse manner to pre‐cover metallic pan surfaces with polymeric, transitioning and carbonaceous films. These pre‐coated pans were then used as the initial test specimen/surface upon which fresh lubricant samples were aged. The effects of pre‐deposits of varied ages were gauged against the baseline of a virgin metallic surface to decouple the lubricant‐deposit system towards resolving their effect upon further deposit growth. From such data, a uniform deposition model describing deposit formation and aging was developed. Chemical characterisation of PSMO deposits by Fourier transform infrared‐attenuated total reflectance and energy‐dispersive X‐ray spectroscope analyses provide additional supporting evidence of changes in chemical bonding (alkyl C–H and carbonyl C=O bond stretching vibrations) and composition (C‐ and O‐atom content) as the deposits undergo deoxygenation and dehydrogenation reactions. Across different aged oils and films, the substitution tests show a declining activity towards mass deposition with film age, interpreted as decline in reactivity. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Natural egg mass deposition by the Humboldt squid (Dosidicus gigas) in the Gulf of California and characteristics of hatchlings and paralarvae – ERRATUM

Natural egg mass deposition by the Humboldt squid (Dosidicus gigas) in the Gulf of California and characteristics of hatchlings and paralarvae – ERRATUM

CFD modelling of CaCO3 crystallization fouling on heat transfer surfaces

Supersaturation of inversely soluble salts, like calcium carbonate, causes crystallization fouling on heated surfaces of heat exchangers. In this paper, crystallization fouling of calcium carbonate is studied by CFD modelling. Crystallization fouling is modelled in 2D and 3D flat plate geometries, which correspond to an experimental set-up of an idealised heat exchanger. The model is validated with experimental data under various operating conditions and is used to identify the regions where different parameters have the greatest effect on fouling.The CFD model presented in this paper is a novel combination of a fouling model, which includes the surface integration term and the shear stress dependent residence time, and the hydrodynamics and heat transfer modelled by CFD. The crystallization fouling CFD model predicts the experimental mass deposition rate and the linear fouling resistance within the experimental uncertainty in most of the studied conditions. The crystallization fouling CFD model is very sensitive to the heat exchanger surface temperature, but also relatively sensitive to the shear stress.The validated crystallization fouling model may be utilised to study fouling of industrial heat exchangers when the fouling is controlled by the surface integration. If mass transfer controls the crystallization fouling, the mass transport of ions should be included to the model.

Langasite-Type Resonant Sensors for Harsh Environments

ABSTRACTOperation of single crystalline Ca3TaGa3Si2O14 (CTGS) and La3Ga5SiO14 (LGS) bulk acoustic wave resonators is demonstrated up to 1270 °C and 1470 °C, respectively. The mass sensitivity of such devices is about 35 cm2 Hz/μg at 800 °C. Therefore, they are sensitive transducers suited to monitoring, for example, mass deposition processes at high temperatures. The electromechanical loss in CTGS is found to be significantly lower than that in LGS. Platinum coated CTGS samples show a remarkable long-term stability at 1000 °C in air. After an initial period of 300 h, the conductivity is found to remain nearly constant for at least 2400 h. Measurements of resonance frequency of CTGS for 1000 h show a qualitatively similar sequence, with an initial systematic increase followed by nearly constant values. In contrast, measurements on platinum-coated LGS plates show a conductivity decreasing by 15 % over a period of 5000 h.

Effect of Resveratrol and Derivatives on Interactions between Alzheimer's Disease Associated Aβ Protein Oligomers and Lipid Membranes: A Quartz Crystal Microbalance Analysis

Resveratrol and derivatives, abundant natural polyphenols in red wine, have been speculated to be responsible for the association between moderate red wine consumption and a reduced incidence of Alzheimer's disease (AD). Amyloid-β (Aβ) protein is highly involved in the pathology of AD, and one proposed mechanism for its pathogenesis is that Aβ aggregates’ interactions with lipid membranes induces cytotoxicity. This study investigates the effect of resveratrol and its derivatives on interactions between Aβ oligomers and lipid membranes modeled by supported lipid bilayers (SPBs).SPBs comprised of POPC, DPPC and DPPG are formed on the surface of a SiO2-coated quartz crystal for monitoring using a quartz crystal microbalance (QCM). QCM is a highly sensitive, real-time mass measurement technique based on the piezoelectric property of quartz. QCM can continually measure a crystal's resonance frequency shifts, which linearly correlate with changes in deposited mass. This study, by measuring the mass deposition rate, evaluates the binding between Aβ oligomeric aggregates and lipid membranes consisting of varying POPC/DPPC/DPPG ratios. The effect of resveratrol and its derivatives on Aβ-lipid interactions is additionally assessed by preparing Aβ oligomers in the presence of different polyphenols and comparing their respective deposition rate upon SPBs.The binding of Aβ aggregates to lipid membrane is believed to cause defects within the membrane and result in functional disorders. Thus, polyphenols that can effectively reduce this binding have the potential to protect membranes from disturbance and might be therapeutic for AD.

3D numerical simulation of debris-flow motion using SPH method incorporating non-Newtonian fluid behavior

Flow-type landslide, such as debris-flow, often exhibits high velocity and long run-out distance. Simulation on it benefits the propagation analysis and provides solution for risk assessment and mitigation design. Previous studies commonly used shallow water assumption to simulate this phenomenon, ignoring the information in vertical direction, and the Bingham model to describe constitutive law of non-Newtonian fluid can cause numerical divergence unless necessary parameter is defined. To address the issue, the full Navier–Stokes equations are adopted to describe the dynamics of the flow-type landslides. Additionally, the general Cross model is employed as the constitutive model, which ensures the numerical convergence. Rheological parameters are introduced from the Bingham model and the Mohr–Coulomb yield criterion. Subsequently, the governing equations incorporating the modified rheological model are numerically built in the smoothed particle hydrodynamics (SPH) framework and implemented into the open-source DualSPHysics code. To illustrate its performance, the 2010 Yohutagawa debris-flow event in Japan is selected as a case study. Parameters regarding the debris magnitude, i.e., the front velocity and section discharge, were also well analyzed. Simulated mass volume and deposition depth at the alluvial fan are in good agreements with the in situ observation. On the basis of the results, the developed method performs well to reproduce the debris-flow process and also benefits the analysis of flow characteristics, affected area for risk assessment and mitigation design.

17α-Estradiol Alleviates Age-related Metabolic and Inflammatory Dysfunction in Male Mice Without Inducing Feminization.

Aging is associated with visceral adiposity, metabolic disorders, and chronic low-grade inflammation. 17α-estradiol (17α-E2), a naturally occurring enantiomer of 17β-estradiol (17β-E2), extends life span in male mice through unresolved mechanisms. We tested whether 17α-E2 could alleviate age-related metabolic dysfunction and inflammation. 17α-E2 reduced body mass, visceral adiposity, and ectopic lipid deposition without decreasing lean mass. These declines were associated with reductions in energy intake due to the activation of hypothalamic anorexigenic pathways and direct effects of 17α-E2 on nutrient-sensing pathways in visceral adipose tissue. 17α-E2 did not alter energy expenditure or excretion. Fasting glucose, insulin, and glycosylated hemoglobin were also reduced by 17α-E2, and hyperinsulinemic-euglycemic clamps revealed improvements in peripheral glucose disposal and hepatic glucose production. Inflammatory mediators in visceral adipose tissue and the circulation were reduced by 17α-E2. 17α-E2 increased AMPKα and reduced mTOR complex 1 activity in visceral adipose tissue but not in liver or quadriceps muscle, which is in contrast to the generalized systemic effects of caloric restriction. These beneficial phenotypic changes occurred in the absence of feminization or cardiac dysfunction, two commonly observed deleterious effects of exogenous estrogen administration. Thus, 17α-E2 holds potential as a novel therapeutic for alleviating age-related metabolic dysfunction through tissue-specific effects.

Initial Growth of Functional Plasma Polymer Nanofilms

To gain deeper insights into the initial growth mechanism, with respect to functional group density and cross-linking, plasma polymer films (PPFs) were deposited from C2H4/NH3 discharges. Keeping gas phase processes and electrical discharge conditions constant all over the deposition process, the mass deposition rate of the PPF was found to be initially lower and regularly increasing before reaching steady-state conditions after a film thickness of about 5 nm on metal oxide substrates. The first gradient nano-layer, i.e. the first 5 nm deposited, were observed to possess less amino functional groups and to be more cross-linked and thus more stable compared to the film prepared in steady state conditions, in which the uniform film comprises more amino functional groups, yet is less cross-linked and thus less stable. Due to its sticking probability, the substrate thus influences the initial deposition rate. Over plasma exposure time, the substrate becomes covered by an initial layer of PPF and the film-forming species are no longer deposited onto the pristine substrate but onto the already deposited organic polymer film. The preparation of the highly stable functional nanofilm, i.e. the initial PPF layer, can lead to new possible applications and fast deposition processes.

Synoptic and mesoscale processes supporting vertical superposition of the polar and subtropical jets in two contrasting cases

Observational studies have shown that the tropopause characteristically exhibits a three‐step Pole‐to‐Equator structure, with each break between steps in the tropopause height associated with a jet stream. While the two jet streams, the polar and subtropical jets, typically occupy different latitude bands, their separation can occasionally vanish, resulting in a relatively rare vertical superposition of the two jets. A cursory examination of several historical and recent high‐impact weather events over North America and the North Atlantic suggests that superposed jets are a component of their evolution. This study examines the processes that support the production of a polar/subtropical jet superposition during two such events; the 18–20 December 2009 Mid‐Atlantic Blizzard and the 1–3 May 2010 Nashville Flood.Given that ageostrophic transverse circulations and convection have both been shown to be capable of restructuring the tropopause within a single jet environment, the analysis focuses on the role these same processes play within the more complex double‐jet environment. The results demonstrate that ageostrophic transverse circulations play a primary role in the production of a superposition during the December 2009 case by placing subsidence, and a downward protrusion of high potential vorticity (PV) air, between the two jet cores, thereby contributing to the production of the single, steep tropopause wall characteristic of the superposed jet environment. Furthermore, convection fundamentally influences the existence and structure of the subtropical jet stream in both cases, through its associated latent heat release and irrotational outflow as well as the geostrophic adjustment process that responds to upper‐tropospheric mass deposition from convection on the anticyclonic shear side of the jet.

Chondrocytic ephrin B2 promotes cartilage destruction by osteoclasts in endochondral ossification.

The majority of the skeleton arises by endochondral ossification, whereby cartilaginous templates expand and are resorbed by osteoclasts then replaced by osteoblastic bone formation. Ephrin B2 is a receptor tyrosine kinase expressed by osteoblasts and growth plate chondrocytes that promotes osteoblast differentiation and inhibits osteoclast formation. We investigated the role of ephrin B2 in endochondral ossification using Osx1Cre-targeted gene deletion. Neonatal Osx1Cre.Efnb2(Δ/Δ) mice exhibited a transient osteopetrosis demonstrated by increased trabecular bone volume with a high content of growth plate cartilage remnants and increased cortical thickness, but normal osteoclast numbers within the primary spongiosa. Osteoclasts at the growth plate had an abnormal morphology and expressed low levels of tartrate-resistant acid phosphatase; this was not observed in more mature bone. Electron microscopy revealed a lack of sealing zones and poor attachment of Osx1Cre.Efnb2(Δ/Δ) osteoclasts to growth plate cartilage. Osteoblasts at the growth plate were also poorly attached and impaired in their ability to deposit osteoid. By 6 months of age, trabecular bone mass, osteoclast morphology and osteoid deposition by Osx1Cre.Efnb2(Δ/Δ) osteoblasts were normal. Cultured chondrocytes from Osx1Cre.Efnb2(Δ/Δ) neonates showed impaired support of osteoclastogenesis but no significant change in Rankl (Tnfsf11) levels, whereas Adamts4 levels were significantly reduced. A population of ADAMTS4(+) early hypertrophic chondrocytes seen in controls was absent from Osx1Cre.Efnb2(Δ/Δ) neonates. This suggests that Osx1Cre-expressing cells, including hypertrophic chondrocytes, are dependent on ephrin B2 for their production of cartilage-degrading enzymes, including ADAMTS4, and this might be required for attachment of osteoclasts and osteoblasts to the cartilage surface during endochondral ossification.

Multistage Continuous Mixed-Suspension, Mixed-Product Removal (MSMPR) Crystallization with Solids Recycle

Continuous crystallization process has potential advantages such as lower cost and improved flexibility in pharmaceutical production when compared to batch crystallization. A good continuous crystallization process should achieve a high product yield and purity comparable to current batch crystallization processes. For compounds that have low growth rates, a high yield is difficult to achieve without long residence times. Solids recycle is a potential solution for this problem as it can increase the surface area of crystals in the crystallizer thus increasing the mass deposition rate. In this study, solids recycle was used in a two-stage continuous mixed-suspension, mixed-product removal (MSMPR) cooling crystallization. Manual solids recycle and the use of a designed column for automatic slurry concentration were employed. The crystallization of cyclosporine, which has very low growth rate (about 0.1 μm/min) at low temperatures in acetone, showed only 65.0% yield in a two-stage MSMPR without solids recycl...