Electro-generated nickel/carbon nanotube composites in ionic liquid

It is reported, for the first time, that compact nickel-multiwalled carbon nanotube (Ni/MWCNT) composites were successfully electrodeposited in choline chloride/urea based deep eutectic solvent (DES) on a copper substrate. Dispersion stability of MWCNTs is excellent in DES nickel chloride solution therefore electrodeposition of Ni/MWCNT composites was easily achieved. MWCNTs were uniformly distributed in the nickel matrix and gave different morphologies and high surface roughness to the coating. Coating with oxygen-functionalized MWCNTs exhibited higher stability and better corrosion resistance than the coating with pristine MWCNTs.     

Multi-walled carbon nanotube modified carbon paste electrode as an electrochemical sensor for the determination of epinephrine in the presence of ascorbic acid and uric acid

A biocompatible electrochemical sensor for selective detection of epinephrine (EP) in the presence of 1000-fold excess of ascorbic acid (AA) and uric acid (UA) was fabricated by modifying the carbon paste electrode (CPE) with multi-walled carbon nanotubes (MWCNTs) using a casting method. The electro-catalytic activity of the modified electrode for the oxidation of EP was investigated. The current sensitivity of EP was enhanced to about five times upon modification. A very minimum amount of modifier was used for modification. The voltammetric response of EP was well resolved from the responses of AA and UA. The electrochemical impedance spectroscopic (EIS) studies reveal the least charge transfer resistance for the modified electrode. The AA peak that is completely resolved from that of EP at higher concentrations of AA and the inability of the sensor to give an electrochemical response for AA below a concentration of 3.0 × 10^? 4 M makes it a unique electrochemical sensor for the detection of EP which is 100% free from the interference of AA. Two linear dynamic ranges of 1.0 × 10^? 4–1.0 × 10^? 5 and 1.0 × 10^? 5–5.0 × 10^? 7 M with a detection limit of 2.9 × 10^? 8 M were observed for EP at modified electrode. The practical utility of this modified electrode was demonstrated by detecting EP in spiked human blood serum and EP injection. The modified electrode is highly reproducible and stable with anti fouling effects.     

Entropy analysis of muscular near-infrared spectroscopy (NIRS) signals during exercise programme of type 2 diabetic patients: Quantitative assessment of muscle metabolic pattern

Diabetes mellitus (DM) is a metabolic disorder that is widely rampant throughout the world population these days. The uncontrolled DM may lead to complications of eye, heart, kidney and nerves. The most common type of diabetes is the type 2 diabetes or insulin-resistant DM.     

Results with collagen fleece coated with fibrin glue (TachoComb). A macroscopical and histological experimental study

Diffuse bleeding from parenchymatous organs at conventional surgery is eliminated with the usual methods coagulation tamponade or styches. We performed experimental series at 9 dogs. After resection of spleen, liver, pancreas and kidney, the bleeding surface was covered by collagen fleece coated with fibrin glue (TachoComb). Postoperatively 7 days, 10 days, 14 days and 28 days we made a relaparotomy. Then the results were analyzed macroscopically and microscopically. In the abdominal cavity neither significant quantity of blood nor greater adhesions were detected. At all cases the fibrin glue was found on place were it was put before. Histologically a perfect wound healing experienced. The fibrin glue (TachoComb) using at diffuse parenchymatous organs' bleeding give a very good results when the wound area is at least 1 cm beyond the immediate wound margin and the fibrin glue is applied onto the wound and pressed on it for 4-5 minutes.     

Linear and nonlinear analysis of normal and CAD-affected heart rate signals

Coronary artery disease (CAD) is one of the dangerous cardiac disease, often may lead to sudden cardiac death. It is difficult to diagnose CAD by manual inspection of electrocardiogram (ECG) signals. To automate this detection task, in this study, we extracted the heart rate (HR) from the ECG signals and used them as base signal for further analysis. We then analyzed the HR signals of both normal and CAD subjects using (i) time domain, (ii) frequency domain and (iii) nonlinear techniques. The following are the nonlinear methods that were used in this work: Poincare plots, Recurrence Quantification Analysis (RQA) parameters, Shannon entropy, Approximate Entropy (ApEn), Sample Entropy (SampEn), Higher Order Spectra (HOS) methods, Detrended Fluctuation Analysis (DFA), Empirical Mode Decomposition (EMD), Cumulants, and Correlation Dimension. As a result of the analysis, we present unique recurrence, Poincare and HOS plots for normal and CAD subjects. We have also observed significant variations in the range of these features with respect to normal and CAD classes, and have presented the same in this paper. We found that the RQA parameters were higher for CAD subjects indicating more rhythm. Since the activity of CAD subjects is less, similar signal patterns repeat more frequently compared to the normal subjects. The entropy based parameters, ApEn and SampEn, are lower for CAD subjects indicating lower entropy (less activity due to impairment) for CAD. Almost all HOS parameters showed higher values for the CAD group, indicating the presence of higher frequency content in the CAD signals. Thus, our study provides a deep insight into how such nonlinear features could be exploited to effectively and reliably detect the presence of CAD.     

Fuel cells for carbon capture and power generation: Simulation studies

The decarbonization of hydrocarbons is explored in this work as a method to produce hydrogen and mitigate carbon dioxide (CO₂) emissions. An integrated process for power generation and carbon capture based on a hydrocarbon fueled-decarbonization unit was proposed and simulated. Ethane and propane were used as fuels and subjected to the thermal decomposition (decarbonization) process. The system is also composed of a carbon fuel cell (CFC) and hydrogen fuel cell (HFC) for the production of power and a pure CO₂ stream that is ready for sequestration. The HFC is a high-temperature proton exchange membrane fuel cell operating at 200 °C. Simulations were performed using ASPEN HYSYS V.10 for the entire process including the CFC and HFC being operated at various operating temperatures (200–800 °C). The power output from the CFC and the HFC as well as the overall process efficiency were calculated. The model incorporates an energy recovery system by adopting a counter-current shell and tube heat exchangers and a turbine. The water produced from the fuel cell system can be utilized in the plant to recover the heat from the furnace. The results showed a 100% carbon capture with a nominal plant capacity of 108 MWe produced when propane fuel was fed to the decarbonizer. The CFC theoretical efficiency is 100% and the practical efficiency was taken as 70% when all internal polarizations were considered. The results showed that, in the case of propane, the CFC power output was 89 MWe when the CFC operated at 650 °C, and the HFC power output was around 45 MWe at 200 °C with an overall actual plant efficiency of 35% and 100% carbon capture. Sensitivity analysis recommends a hydrocarbon fuel cost of 0.011 $/kW as the most feasible option. The results reported here on the decarbonization of hydrocarbon fuels are promising toward the direct production of hydrogen with full carbon dioxide sequestration at a potentially lower cost especially in rural areas. The overall actual efficiencies are very competitive to those of conventional power plants operated without carbon capture.     

Effect of vitamin E on peroxidation and permeability of the peritoneum

Because of the evidence that peritoneal macrophages are activated during peritoneal dialysis, we hypothesised that the injury of the peritoneum is, at least in part, dependent on the intraperitoneal generation of free radicals. The aim of the study was to evaluate the effect of vitamin E on the peroxidation and permeability of the peritoneum during chronic peritoneal dialysis in rats. Supplementation of the intraperitoneally infused saline with vitamin E decreased the peroxidation of peritoneum estimated as the malondialdehyde (MDA) level in rats' omentum. However the permeability of the peritoneum to glucose and protein in vitamin E treated rats was increased. In in vitro study we have found that vitamin E is cytotoxic to human mesothelial cells (HMC) as measured by inhibition of their proliferation and this effect was irreversible. We conclude that vitamin E, despite its antioxidant effect, causes the changes of the peritoneum permeability which could decrease the effectiveness of peritoneal dialysis.     

Permanent magnetic materials with low reversible temperature coefficient

Permanent magnets made from SmCo5exhibit negative reversible change in magnetization with increasing temperature, typically of the order of 0.04% per deg C between -100 and +200°C. For certain special applications in precision instruments such as gyros and accelerometers, it is highly desirable to improve this property. Earlier studies have shown that ternaries of the composition RxSm1-xCo5(where R = Gd, Ho, Er, or Dy and x is nearly 0.4) exhibit improved temperature compensation. A systematic investigation of the temperature coefficients of magnetization of a number of quaternaries in the temperature range 100-400 K has been undertaken. The effect of variation of the cobalt concentration on the temperature compensation of one typical system has also been examined. The results indicate that good temperature compensated magnets can be synthesized with composition Sm0.6Gd0.3DY0.1Co5(α = 0.0056 at 200-300 K; 0.002 at 300-350 K and ∼0 at 350-400 K). Slight variation of cobalt concentration does not have significant effects on the temperature compensation. Lattice constants, saturation magnetization, and the theoretical energy products of a number of quaternaries are also reported.     

SIMULTANEOUS ETHANE AND ETHYLENE DETECTION USING A CO-OVERTONE LASER PHOTOACOUSTIC SPECTROMETER: A NEW TOOL FOR STRESS/DAMAGE STUDIES IN PLANT PHYSIOLOGY

Abstract

The simultaneous measurement of the C₂H₆ and C₂H₄ emission by plant material is known to be a good stress/damage indicator. A photoacoustic spectrometer, utilizing the CO-Overtone laser, has been used for such measurements for the first time. For the simultaneous online detection of C₂H₆ and C₂H₄ in plant physiological studies, a sensitivity was achieved of 370 ppt and 2 ppb, respectively. The performance of the system has been demonstrated measuring the stress/damage behaviour of rhododendron leaves after the application of freezing stress.