Studying physiochemical changes in a new pasta product containing beef heart by vibrational spectroscopy

A new pasta product was developed by partially replacing durum wheat flour with beef heart to enhance its nutritional value. Physiochemical changes of the pasta were investigated by vibrational spectroscopy, namely Fourier transform infrared (FT-IR) and Raman spectroscopy. Relationships between pasta texture and the intensity of vibrational spectra were established. Lipid-protein complex formation, β-sheet arrangement, degree of polysaccharide polymerization, and cysteine thiol group were related to hardness and chewiness of pasta. The lipid portion and β-sheet structure were two significant parameters for explaining pasta adhesiveness, while pasta firmness might be related to β-sheet alignment and the polysaccharide network. Pasta cohesiveness might involve the α-helical structures and hydrogen bonding formation in the gluten network. However, no variable met the p < 0.1 significance level for inclusion into the model to explain pasta springiness. These results reveal that FT-IR and Raman spectroscopy could be employed to evaluate the physical chemistry of pasta and showed a potential use for quality assessment in pasta products.     

Interpretation of partial discharges at dc voltages

The aim of this paper is to give an overview on partial discharges at dc voltage. A model is presented which describes the stochastic discharge process. The model is experimentally verified for internal discharges and for corona in air. In addition, the classification of discharge patterns is discussed. The 3-dimensional histogram describing the number of discharges depending on the discharge magnitude and on the time to the successive discharge is suggested to be used as a base for discharge recognition at dc voltage. Experimental proof is presented to show the strength of this approach     

Scavenging of As from acid mine drainage by schwertmannite and ferrihydrite: a comparison with synthetic analogues

Ochreous precipitates containing 5.5-69.8 g/kg As were isolated from mine drainage in Finland and were composed of schwertmannite, ferrihydrite, and goethite. Schwertmannite formation was favored at pH 3-4, but its structure was degraded at high As levels. A series of coprecipitates were therefore prepared from mixed iron arsenate/sulfate solutions to define the limits of schwertmannite stability. Schwertmannite was replaced as the dominant phase by a poorly crystalline ironIII hydroxy arsenate (FeOHAs) when As/Fe mole ratios exceeded 0.15. The FeOHAs gave an X-ray diffraction pattern similar to that obtained from an "amorphous" ironIII arsenate (As/Fe = 1.0) with broad peaks at 0.30 and 0.16 nm. The FeOHAs possessed a magnetic hyperfinefield of 41.9T at 4.2 K that was intermediate to those of schwertmannite (46.1 T) and the ironIII arsenate (24.8 T). These data indicate a strong disruptive effect of arsenate on magnetic ordering and structure development in schwertmannite. Equilibration of 0.01 M arsenate solutions with freshly prepared schwertmannite and 2-line ferrihydrite at pH 3.0 for up to 60 d gave sorbed As contents of 175 and 210 g/kg, respectively. Arsenate sorption degraded the host schwertmannite and ferrihydrite, perhaps due to the formation of an FeOHAs surface phase.     

Evidence that leptin contributes to intestinal cholesterol absorption in obese (ob/ob) mice and wild-type mice

In the present study, the effect of leptin on intestinal cholesterol absorption was investigated in C57 BL/6 OlaHsd Lep^ob/Lep^ob obese (ob/ob) mice and lean C57 BL/6 (wild-type) mice. Animals were treated either with or without recombinant leptin for 2 wk. Cholesterol absorption was measured by the constant isotope feeding method and indirectly by the ratio of campesterol to cholesterol in serum. In ob/ob mice, cholesterol absorption was significantly higher compared to wild-type mice [83.4±2.3% (SD) vs. 77.6±1.5%, P<0.01]. Treatment with leptin significantly reduced cholesterol absorption in both ob/ob and wild-type mice by 8.5 (P<0.001) and 5.2% (P<0.05), respectively. Serum concentrations of campesterol and the ratio of campesterol to cholesterol in ob/ob mice were significantly higher compared to wild-type mice (2.2±0.3 mg/dL vs. 1.2±0.3 mg/dL, P<0.001; and 36.8±2.8 μg/mg vs. 28.0±3.3 μg/mg, P<0.001). After treatment of ob/ob mice with leptin, concentrations of campesterol and its ratio to cholesterol were significantly lower (2.2±0.3 mg/dL vs. 1.0±0.2 μg/mg, P<0.001; and 36.8±2.8 μg/mg vs. 13.2±2.2 μg/mg, P<0.001, respectively). In wild-type mice, the ratio of campesterol to cholesterol in serum was also significantly lower after treatment with leptin (28.0±3.3 μg/mg vs. 22.6±5.0 μg/mg, P<0.05). A significant positive correlation (r=0.701, P<0.01) between cholesterol absorption and the ratio of campesterol to cholesterol, in serum was found. It is concluded that leptin contributes to intestinal cholesterol absorption in ob/ob mice and lean wild-type mice.     

Processing characteristics of PTCR ceramics with low sintering temperature

The processing behavior of PTCR ceramics of (Ba,Sr,Ca,Pb)TiO₃ solid solution composition with additives of lanthanum oxide (La₂O₃) and boron nitride (BN) was studied. The ceramics can be sintered at temperatures as low as 1100 °C and possess rather low room-temperature resistivity with good PTCR effect. The sample ball milled with de-ionized water exhibits a more uniform microstructure compared to the sample ball-milled with alcohol. Particle size of less than 1 m was found to be adequate for preparing the ceramics and the finer particles (0.45 m) do not significantly improve the PTCR behavior. The performance of the PTCR sample is not sensitive to the sintering parameters such as the sintering time and cooling rate. This may be ascribed to the presence of excess BaO in the sample and the low sintering temperature, thereby eliminating the effect of Ba ion vacancies on the properties of the PTCR sample.     

Histomorphological, histomorphometrical and biomechanical analysis of ceramic bone substitutes in a weight-bearing animal model

It was the purpose of this investigation to prove the biomechanical properties, the osteoconductive capacity and the degradation rate of tricalcium phosphate ( TCP), a neutralized glass ceramics (GB9N) and a composite material (GB9N+copolymers). In a weight-bearing animal model six substitutes each were implanted in the medial tibial head of the right lower leg of adult Merino-sheep in a standardized surgical technique. After nine months the implants were harvested and prepared for histomorphological and histomorphometrical investigations (undecalcified Masson Goldner staining). For additional biomechanical testing of the specimens, non-operated bone blocks from the contralateral tibia as well as native implants served as controls. No significant differences for the maximum fracture load as well as for the yield strength were detected between harvested specimens and bone blocks from the contralateral tibia. However there were marked differences to ceramics that were not implanted. All substitutes showed osteoconduction, leading to a continuous ingrowth of new formed bone. However in the composite material soft tissue could be identified within the scaffold and there were signs of ongoing bone remodeling, nine months after implantation. The bone per tissue volume of -TCP in conjunction to new bone (=percentage of trabecular bone volume plus percentage of residual substitute) was higher than for GB9N and the composite material. Nine months after implantation the percentage of residual -TCP was 48%, it was 32% for GB9N and 28% for the composite.The intention of further studies should be to accelerate the degradation rates of substitutes and to improve biomechanical properties of implants by either modifying the chemical composition or combining materials with agents as, e.g. growth factors.     

QoS Recovery Schemes Based on Differentiated MPLS Services in All-Optical Transport Next Generation Internet

The Internet is evolving from best-effort service toward an integrated or differentiated service framework with quality-of-service (QoS) assurances that are required for new multimedia service applications. Given this increasing demand for high bandwidth Internet with QoS assurances in the coming years, an IP/MPLS-based control plane combined with a wavelength-routed dense wavelength division multiplexing (DWDM) optical network is seen as a very promising approach for the realization of future re-configurable transport networks. Fault and attack survivability issues concerning physical security in a DWDM all-optical transport network (AOTN) require a new approach taking into consideration AOTN physical characteristics. Furthermore, unlike in electronic networks that regenerate signals at every node, attack detection and isolation schemes may not have access to the overhead bits used to transport supervisory information between regenerators or switching sites to perform their functions. This paper presents an analysis of attack and protection problems in an AOTN. Considering this, we propose a framework for QoS guarantees based on the differentiated MPLS service (DMS) model and QoS recovery schemes against QoS degradation caused by devices failures or attack-induced faults in an AOTN. We also suggest how to integrate our attack management model into the NISTs simulator—modeling, evaluation and research of lightwave networks (MERLiN).     

A system for rapid large-area monitoring of gamma dose rates in the environment based on MCP-N (LiF:Mg,Cu,P) TL detectors

One lesson learned from the Chernobyl accident was that the spatial distribution of far-field contamination was strongly non-uniform due to local variation of atmospheric conditions, such as wind direction, rain etc. An environmental monitoring system using highly sensitive thermoluminescent LiF:Mg,Cu,P (MCP-N) detectors has been completed and field-tested. The system consists of 3000 MCP-N detectors in 1000 TLD cards (three TLDs per card), two Mikrolab automatic TL readers, heating ovens, and specially developed software which includes a database for rapid evaluation of results. The main dosimetric parameters of MCP-N dosemeters, such as thermally-induced fading, light sensitivity, minimum detectable dose, self-dose, zero-dose, energy response up to 6-7 MeV, influence of annealing and readout conditions on detector stability, have been tested. About 100 locations over an area of about 15,000 km2 in the south of Poland were selected for measurements lasting from 4 days to 3 months. The kerma rates measured over a 4 day screening period agree well with kerma rates determined over a 75 day monitoring period. Results from short- and long-term exposure periods agree well with those performed using MTS-N (LiF:Mg,Ti) over southern Poland in 1985, before the Chernobyl accident. Thus, using the system based on MCP-N detectors, one is able simultaneously to monitor environmental radiation kerma rates at a large number of locations over periods of four days or less. Provided natural background kerma rates at selected monitoring points are available prior to the accident, the system can be applied to assess kerma rates rapidly in the environment, following a nuclear accident.     

Fabrication and electroosmotic flow measurements in micro- and nanofluidic channels

An easy method for fabricating micro- and nanofluidic channels, entirely made of a thermally grown silicon dioxide is presented. The nanochannels are up to 1-mm long and have widths and heights down to 200 nm, whereas the microfluidic channels are 20-μm wide and 4.8-μm high. The nanochannels are created at the interface of two silicon wafers. Their fabrication is based on the expansion of growing silicon dioxide and the corresponding reduction in channel cross-section. The embedded silicon dioxide channels were released and are partially freestanding. The transparent and hydrophilic silicon dioxide channel system could be spontaneously filled with aqueous, fluorescent solution. The electrical resistances of the micro- and nanofluidic channel segments were calculated and the found values were confirmed by current measurements. Electrical field strengths up to 600 V/cm were reached within the nanochannels when applying a potential of only 10 V. Electroosmotic flow (EOF) measurements through micro- and nanofluidic channel systems resulted in electroosmotic mobilities in the same order of those encountered in regular, fused silica capillaries.