Synthesis and characterization of calcium phosphate coatings on Nitinol

In recent years, coating of metal orthopedic implants with bioactive layers to promote fixation with bones has become increasingly common. Calcium phosphate coatings on the Nitinol surface were formed using two low-temperature methods: sol–gel and electrochemically assisted deposition. The coatings formed were characterized using: X-ray diffraction analysis, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. Cyclic voltammetry studies were carried out in the deposition solution to determine parameters for electrodeposition and to understand electrochemistry of deposition. The barrier properties and corrosion resistance of coatings were tested in the physiological Hanks’ solution using electrochemical impedance spectroscopy. The sol–gel deposited coating consisted of two phases, hydroxyapatite and tricalcium phosphate (TCP). Apatite coatings containing TCP offered the opportunity to create a grafting material with high bioactivity and bioresorbility. The electrodeposited coating consisted of Ca-deficient HAp which resembles to biological HAp.     

Rietveld refinement and estimation of residual stress in GDC–LSCF oxygen transport membrane ceramic composites

The phase purity and crystal structure of dual-phase Ce_.9Gd_.1O_2–δ–La_.6Sr_.4Co_.2Fe_.8O_3–δ (GDC–LSCF) composites were refined using data obtained from X-ray diffraction (XRD) by employing the Rietveld method. Rietveld analysis indicated that the structures of GDC and LSCF phases are well crystallized as cubic Fm$\stackrel{?}{3}$m and rhombohedral R$\stackrel{?}{3}$c space groups, respectively. Scanning electron microscopy images showed smooth and dense structures, depicting a homogeneous crystalline structure of the samples. When the composites were cooled from their sintering temperature (1250?°C), compressive stresses were generated in the GDC and corresponding tensile stresses were generated in the LSCF due to differences in thermal expansion coefficients. The compressive residual stresses of the composites were investigated by high-angle XRD measurements using the well-known sin²ψ method. The average compressive residual stresses in GDC phase are estimated to be ??312 and ??290?MPa for 80 GDC–20 LSCF and 50 GDC–50 LSCF, respectively. The aim of this study is to provide a better understanding of the crystal structures and residual stresses in GDC–LSCF composites through XRD and the suitability of these composites for oxygen transport membranes.     

Machine learning method for knowledge discovery experimented with otoneurological data

We have been interested in developing an otoneurological decision support system that supports diagnostics of vertigo diseases. In this study, we concentrate on testing its inference mechanism and knowledge discovery method. Knowledge is presented as patterns of classes. Each pattern includes attributes with weight and fitness values concerning the class. With the knowledge discovery method it is possible to form fitness values from data. Knowledge formation is based on frequency distributions of attributes. Knowledge formed by the knowledge discovery method is tested with two vertigo data sets and compared to experts' knowledge. The experts' and machine learnt knowledge are also combined in various ways in order to examine effects of weights on classification accuracy. The classification accuracy of knowledge discovery method is compared to 1- and 5-nearest neighbour method and Naive-Bayes classifier. The results showed that knowledge bases combining machine learnt knowledge with the experts' knowledge yielded the best classification accuracies. Further, attribute weighting had an important effect on the classification capability of the system. When considering different diseases in the used data sets, the performance of the knowledge discovery method and the inference method is comparable to other methods employed in this study.     

Effect of laccase and transglutaminase on the textural and water-binding properties of cooked chicken breast meat gels

The effects of laccase and transglutaminase (TG) on the firmness and weight loss of cooked chicken meat homogenate gels were investigated at laboratory scale. The salt, trisodium pyrophosphate and meat contents were also used as variables. Laccase decreased firmness and increased weight loss of phosphate-free, low-meat (65%) and low-salt (1%) gels, although it modified myosin and troponin T and reacted with isolated myofibrils. By applying both low-salt (1%) and low-phosphate (0.17%) amounts, gel firmness decreased and weight loss increased (p<0.05) greatly. A high dosage of TG significantly improved (p<0.05) the strength of phosphate-free, low-meat and low-salt homogenate gels compared to the corresponding no-enzyme controls. TG improved gel firmness of the low-meat homogenate to the level of the homogenate containing 75% meat. Weight loss was increased significantly (p<0.05) in all cases when the high-TG dosage was used. Enzymes were not capable of improving either texture or water-holding capacity in the low-salt–low-phosphate system. The firmness and cooking loss of the chicken meat products containing different amounts of meat, salt and TG were investigated at pilot scale. Under the conditions and dosages used, TG was capable of improving (p<0.05) firmness of the products without a significant reduction in water-holding capacity.     

Corrosion protection of anisotropically conductive adhesive joined flip chips

Corrosion is a common cause of failure in electronic devices. Conformal coatings may be used to prevent corrosion of electronics packages. Water and contaminants are thus not in direct contact with the package surface, which may improve resistance to corrosion. However, it is important to study the effects of corrosion on both coating materials and on the electronics itself. The protection method and the level of protection can then be selected.This study presents a salt spray test of anisotropically conductive adhesive joined flip chip components on FR-4 substrate, where half of the test samples were parylene C coated. A dramatic difference was seen between these two test lots. Parylene C proved to be an excellent barrier against salt spray. The test lots without conformal coating suffered severe corrosion, and were thus considerably less reliable. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) revealed the reasons for the failures in the non-coated test samples. The main reason was found to be severe corrosion of the nickel layer. There were no failures among the parylene C coated test samples during the 3000 h test. Moisture absorption of the FR-4 substrate material is also studied in this paper. Both plain FR-4 and parylene C coated FR-4 materials were studied. These tests were performed both at room temperature and in boiling water.     

Electrochemical Wear of Carbon Cathodes in Electrowinning of Aluminum

Cathode wear is the main factor limiting the lifetime of high-amperage aluminum electrolysis cells with graphitized cathodes. The current article deals with an investigation of cathode wear in a laboratory cell, where the cathode is directly exposed to the electrolyte during electrolysis. The wear was shown to be electrochemical in nature and dependent on the current density, the rotation speed, and the depth of prefabricated slots in the cylindrical cathodes. The wear mechanism is discussed with respect to kinetics influencing the electrochemistry as well as the solubility of aluminum carbide in the electrolyte.     

Nutrient discharges to Biscayne Bay, Florida: trends, loads, and a pollutant index

Changes in land use, management practices, and environmental conditions may all lead to detectable differences in nutrients transported to aquatic systems. Biscayne Bay, an oligotrophic estuary in southeastern Florida, requires minimal phosphorus and nitrogen inputs and here we quantified the effects of continued watershed development. Nutrient (nitrate/nitrite-nitrogen [NO_X-N], total ammonia nitrogen [NH₃-N], and total phosphorus [TP]) water quality data (1992-2006) from six monitoring sites were evaluated using trend analysis, load estimation, and a new Pollutant Empower Density (PED) index. The PED index assesses the effect of discharged pollutants relative to the background productivity of aquatic environments. NO_X-N, NH₃-N, and TP concentrations declined or exhibited no change at most sites, with only six instances of significantly (p < 0.1) increasing trends. Load estimates revealed higher NO_X-N loads in the southern, agricultural section of the watershed and higher NH₃-N and TP loads in the urbanized northern and central areas. NO_X-N loads from site MW04 (south) were the highest for all sites while site LR06 (north) had the highest NH₃-N and TP loads. Of the evaluated canal discharges, PED index values also suggested that canal discharges from these two sites (MW04 and LR06) had the greatest potential for impact in the bay. Overall, water quality is generally improving but canal discharges are coupled with land use activities in adjacent drainage areas. Trend analysis, load estimation, and the PED index can be used together to provide a more holistic interpretation of water quality, which is necessary for optimizing resources to meet watershed management goals.     

Characterization of Volatile Organic Compounds Emitted by Barley (Hordeum vulgare L.) Roots and Their Attractiveness to Wireworms

Root volatile organic compounds (VOCs), their chemistry and ecological functions have garnered less attention than aboveground emitted plant VOCs. We report here on the identification of VOCs emitted by barley roots (Hordeum vulgare L.). Twenty nine VOCs were identified from isolated 21-d-old roots. The detection was dependent on the medium used for root cultivation. We identified 24 VOCs from 7-d-old roots when plants were cultivated on sterile Hoagland gelified medium, 33 when grown on sterile vermiculite, and 34 on non-sterile vermiculite. The major VOCs were fatty acid derived compounds, including hexanal, methyl hexanoate, (E)-hex-2-enal, 2-pentylfuran, pentan-1-ol, (Z)-2-(pentenyl)-furan, (Z)-pent-2-en-1-ol, hexan-1-ol, (Z)-hex-3-en-1-ol, (E)-hex-2-en-1-ol, oct-1-en-3-ol, 2-ethylhexan-1-ol (likely a contaminant), (E)-non-2-enal, octan-1-ol, (2E,6Z)-nona-2,6-dienal, methyl (E)-non-2-enoate, nonan-1-ol, (Z)-non-3-en-1-ol, (E)-non-2-en-1-ol, nona-3,6-dien-1-ol, and nona-2,6-dien-1-ol. In an olfactometer assay, wireworms (larvae of Agriotes sordidus Illiger, Coleoptera: Elateridae) were attracted to cues emanating from barley seedlings. We discuss the role of individual root volatiles or a blend of the root volatiles detected here and their interaction with CO₂ for wireworm attraction.     

Effect of lubricant on the formation of heavy-duty diesel exhaust nanoparticles

The effect of lubricants on nanoparticle formation in heavy-duty diesel exhaust with and without a continuously regenerating diesel particulate filter (CRDPF) is studied. A partial flow sampling system with a particle size distribution measurement starting from 3 nm, approximately, is used. Tests are conducted using four different lubricant formulations, a very low sulfur content fuel, and four steady-state driving modes. A well-documented test procedure was followed for each test. Two different kinds of nanoparticle formation were observed, and both were found to be affected bythe lubricant but in differentway. Without CRDPF, nanoparticles were observed at low loads. No correlation between lubricant sulfur and these nanoparticles was found. These nanoparticles are suggested to form mainly from hydrocarbons. With CRDPF, installed nanoparticles were formed only at high load. The formation correlated positively with the lubricant (and fuel) sulfur level, suggesting that sulfuric compounds are the main nucleating species in this situation. Storage effects of CRDPF had an effect on nanoparticle concentration as the emissions of nanoparticles decreased over time.