737 research outputs found
The impact of the particle size of meat and bone meal (MBM) incineration ash on phosphate precipitation and phosphorus recovery
Meat and bone meal (MBM) ash was characterized and used for phosphate wastewater treatment and phosphorus recovery. The bottom ash (MBM-BA) with size >250 μm accounted for ~80% and distributed evenly in the >1000 μm, 500-1000 μm, and 250-500 μm fractions, while air pollution control residue (MBM-APCr) distributed evenly among the 250-500 μm, 125-250 μm, and 1000 μm and 8 was favorable to P removal. Based on the compositions of the solid phases, extracts before and after treatment, and Ca/P ratio 1.22-1.73, the phosphate removal mechanisms were dominated by HAP crystallization/precipitation. Using MBM-BA for wastewater treatment increased its P content to 16.30%. Depending on particle size, the acid consumption for P recovery of 84% from MBM-BA was 2.6-3.0 mM H+/mM P. Strategies for management and utilization of MBMA according to these findings were proposed
Bioresponsive microspheres for on‐demand delivery of anti‐inflammatory cytokines for articular cartilage repair
Despite innovations in surgical interventions, treatment of cartilage injury in osteoarthritic joints remains a challenge due to concomitant inflammation. Obstructing a single dominant inflammatory cytokine has shown remarkable clinical benefits in rheumatoid arthritis, and similar strategies are being suggested to target inflammatory pathways in osteoarthritis (OA). Here, we describe the utility of gelatin microspheres that are responsive to proteolytic enzymes typically expressed in arthritic flares, resulting in on‐demand and spatiotemporally controlled release of anti‐inflammatory cytokines for cartilage preservation and repair. These microspheres were designed with a net negative charge to sequester cationic anti‐inflammatory cytokines, and the magnitude of the negative charge potential increased with an increase in crosslinking density. Collagenase‐mediated degradation of the microspheres was dependent on the concentration of the enzyme. Release of anti‐inflammatory cytokines from the loaded microspheres directly correlated with the degradation of the gelatin matrix. Exposure of the IL‐4 and IL‐13 loaded microspheres reduced the inflammation of chondrocytes up to 80%. Hence, the delivery of these microspheres in an OA joint can attenuate the stimulation of chondrocytes and the resulting secretion of catabolic factors such as proteinases and nitric oxide. The microsphere format also allows for minimally invasive delivery and is less susceptible to mechanically induced drug release. Consequently, bioresponsive microspheres can be an effective tool for cartilage preservation and arthritis treatment.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153665/1/jbma36852_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153665/2/jbma36852.pd
Проблеми розвитку регіональної економіки: старопромислової регіони та нові точки соціально-економічного росту
Interdigitated back contact silicon heterojunction solar cells Towards an industrially applicable structuring method
We report on the investigation and comparison of two different processing approaches for interdigitated back contacted silicon heterojunction solar cells our photolithography based reference procedure and our newly developed shadow mask process. To this end, we analyse fill factor losses in different stages of the fabrication process. We find that although comparably high minority carrier lifetimes of about 4 ms can be observed for both concepts, the shadow masked solar cells suffer yet from poorly passivated emitter regions and significantly higher series resistance. Approaches for addressing the observed issues are outlined and first solar cell results with efficiencies of about 17 and 23 for shadow masked and photolithographically structured solar cells, respectively, are presente
Evolution of E2 transition strength in deformed hafnium isotopes from new measurements on Hf, Hf, and Hf
The available data for E2 transition strengths in the region between
neutron-deficient Hf and Pt isotopes are far from complete. More and precise
data are needed to enhance the picture of structure evolution in this region
and to test state-of-the-art nuclear models. In a simple model, the maximum
collectivity is expected at the middle of the major shell. However, for actual
nuclei, this picture may no longer be the case, and one should use a more
realistic nuclear-structure model. We address this point by studying the
spectroscopy of Hf. We remeasure the 2^+_1 half-lives of 172,174,176Hf, for
which there is some disagreement in the literature. The main goal is to
measure, for the first time, the half-lives of higher-lying states of the
rotational band. The new results are compared to a theoretical calculation for
absolute transition strengths. The half-lives were measured using \gamma-\gamma
and conversion-electron-\gamma delayed coincidences with the fast timing
method. For the determination of half-lives in the picosecond region, the
generalized centroid difference method was applied. For the theoretical
calculation of the spectroscopic properties, the interacting boson model is
employed, whose Hamiltonian is determined based on microscopic energy-density
functional calculations. The measured 2^+_1 half-lives disagree with results
from earlier \gamma-\gamma fast timing measurements, but are in agreement with
data from Coulomb excitation experiments and other methods. Half-lives of the
4^+_1 and 6^+_1 states were measured, as well as a lower limit for the 8^+_1
states. We show the importance of the mass-dependence of effective boson charge
in the description of E2 transition rates in chains of nuclei. It encourages
further studies of the microscopic origin of this mass dependence. New data on
transition rates in nuclei from neighboring isotopic chains could support these
studies.Comment: 16 pages, 16 figures, 7 tables; Abstract shortened due to character
limi
Use of Micro-Computed Tomography to Nondestructively Characterize Biomineral Coatings on Solid Freeform Fabricated Poly (L-Lactic Acid) and Poly (ɛ-Caprolactone) Scaffolds In Vitro and In Vivo
Biomineral coatings have been extensively used to enhance the osteoconductivity of polymeric scaffolds. Numerous porous scaffolds have previously been coated with a bone-like apatite mineral through incubation in simulated body fluid (SBF). However, characterization of the mineral layer formed on scaffolds, including the amount of mineral within the scaffolds, often requires destructive methods. We have developed a method using micro-computed tomography (?-CT) scanning to nondestructively quantify the amount of mineral in vitro and in vivo on biodegradable scaffolds made of poly (L-lactic acid) (PLLA) and poly (?-caprolactone) (PCL). PLLA and PCL scaffolds were fabricated using an indirect solid freeform fabrication (SFF) technique to achieve orthogonally interconnected pore architectures. Biomineral coatings were formed on the fabricated PLLA and PCL scaffolds after incubation in modified SBF (mSBF). Scanning electron microscopy and X-ray diffraction confirmed the formation of an apatite-like mineral. The scaffolds were implanted into mouse ectopic sites for 3 and 10 weeks. The presence of a biomineral coating within the porous scaffolds was confirmed through plastic embedding and ?-CT techniques. Tissue mineral content (TMC) and volume of mineral on the scaffold surfaces detected by ?-CT had a strong correlation with the amount of calcium measured by the orthocresolphthalein complex-one (OCPC) method before and after implantation. There was a strong correlation between OCPC pre- and postimplantation and ?-CT measured TMC (R2=0.96 preimplant; R2=0.90 postimplant) and mineral volume (R2=0.96 preimplant; R2=0.89 postimplant). The ?-CT technique showed increases in mineral following implantation, suggesting that ?-CT can be used to nondestructively determine the amount of calcium on coated scaffolds.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140242/1/ten.tec.2012.0495.pd
Electrode positions, transformation coordinates for ECG reconstruction from S-ICD vectors.
The article contains data pertaining to the reconstruction of an 8-lead ECG from 2 subcutaneous implantable cardioverter defibrillator vectors. The location of electrodes on the precordium required for the data collection are detailed; the flow chart for patient selection and exclusion is shown; the summary data of the root mean square error (RMSE) (in microvolts) and Pearson r for the ECG transformation all cases and the pearson correlation for all the leads measured and reconstructed leads are also shown. Detailed background, methodology and discussion can be found in the linked research article
Symmetry-breaking transitions in networks of nonlinear circuit elements
We investigate a nonlinear circuit consisting of N tunnel diodes in series,
which shows close similarities to a semiconductor superlattice or to a neural
network. Each tunnel diode is modeled by a three-variable FitzHugh-Nagumo-like
system. The tunnel diodes are coupled globally through a load resistor. We find
complex bifurcation scenarios with symmetry-breaking transitions that generate
multiple fixed points off the synchronization manifold. We show that multiply
degenerate zero-eigenvalue bifurcations occur, which lead to multistable
current branches, and that these bifurcations are also degenerate with a Hopf
bifurcation. These predicted scenarios of multiple branches and degenerate
bifurcations are also found experimentally.Comment: 32 pages, 11 figures, 7 movies available as ancillary file
Untersuchungen an den Ladungen 3 und 4 des Schnell-Thermischen Argonaut-Reaktors STARK. EUR 3701. = Studies on the charges 3 and 4 of the quick-thermal Argonaut reactor STARK. EUR 3701.
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