Loss Of Other Components Research Articles

Extraction of Coupling Coefficients of Directional Couplers Using Resonance Splitting

We theoretically and experimentally present a novel method to accurately extract coupling coefficients of directional couplers using a single circuit. It utilizes the phenomenon of resonance splitting induced by mode coupling in a ring resonator, where the splitting distance is directly proportional to the coupling coefficient of the coupler that couples two modes. Compared with previous approaches, it doesn't rely upon measured amplitudes for parameter extraction, therefore, this method is insensitive to the uncertainties in the losses of other components in the circuit such as fiber/chip couplers, waveguides and resonators, as well as gage errors. More importantly, it can work with very weak coupling coefficients, down to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> .

Driving factors and changes in components of terrestrial water storage in the endorheic Tibetan Plateau

Terrestrial water storage (TWS) in the endorheic Tibetan Plateau (ETP) increased from 2002 to 2012 but decreased in 2012–2016. This study used Gravity Recovery and Climate Experiment (GRACE) data and Global Land Data Assimilation System (GLDAS) data to analyse TWS changes in the ETP in 2012 from increasing to decreasing. The results showed that these TWS changes could be divided into two stages. From April 2002 to August 2012, TWS increased at a rate of 4.43 Gt/yr from the GRACE-Mascons and 1.11 Gt/yr from the GRACE-SH, whereas after September 2012, it declined at a rate of-5.62 Gt/yr from the GRACE-Mascons and −6.99 Gt/yr from the GRACE-SH. The increase in lake water storage (LWS) (7.98 Gt/yr) was higher than the loss of other components from 2002 to 2012, therefore, the LWS gradually dominated the increase in TWS. However, the soil moisture storage (SMS) decreased more significantly (-5.27 Gt/yr) than the increase in LWS (<1 Gt/yr) during 2012–2016, accounting for 66% of the decrease in TWS in the ETP. From a water balance perspective, the relationship between precipitation (P) and evapotranspiration determined the region’s changes in TWS. It was found that 90% of the decrease in TWS in the ETP during 2012–2016 was attributed to an increase in potential evapotranspiration (PET), whereas 7% was attributed to a decrease in P. Thus, climate change (P and PET) accounted for 97% of the TWS reduction during 2012–2016. Furthermore, 3% of the decrease in TWS in the region was attributed to land surface changes.

Effect of Water Temperature and Time during Heating on Mass Loss and Rheology of Cheese Curds.

During the manufacturing of mozzarella, cheese curds are heated to the desired stretching temperature traditionally by immersion in water, which influences the curd characteristics before stretching, and consequently the final cheese properties. In this study, cheese curds were immersed in hot water at 60, 70, 80 and 90 °C up to 16 min and the kinetics of mass loss and changes of rheological properties were investigated. The total mass of cooked curds increased up to 10% during the first minute, independent of the temperature, as a consequence of water retention. Fat was the main component lost into the cooking water (<3.5% w/w), while the concentration of protein increased up to 3.4% (w/w) compared to uncooked curds due to the loss of other components. Curds macrostructure during cooking showed that curds fully fuse at 70 °C/4 min; 80 °C/2 min and 90 °C/1 min, while after intensive cooking (>8 min) they lost the ability to fuse as a consequence of protein contraction and fat loss. Storage modulus, representing the curd strength, was dependent on cooking temperature and positively, and linearly, correlated with curd protein content (21.7–24.9%). This work shows the potential to modify curd composition and structure, which will have consequences for further processing and final product properties.

Maximizing the enzyme immobilization of enzymatic glucose biofuel cells through hierarchically structured reduced graphene oxide

The number of immobilized glucose oxidase (GOx) molecules is considerably increased by the structural modification of reduced graphene oxide (rGO), and the performance of enzymatic biofuel cells (EBFCs) is positively affected by the modification process. To do this, new rGO with three-dimensional open porous structure is formed by spray freeze drying method (sprGO), while tetrathiafulvalene (TTF) as mediator, and GOx are sequentially immobilized onto sprGO. To improve the loading amount of catalyst, rGO structure is modified to open porous sprGO structure possessing numerous anchoring sites, after which gelatin film crosslinked by glutaraldehyde is fabricated onto sprGO to prevent any losses of other components (sprGO/[TTF-GOx]/crosslinked-gelatin). Specific surface area and charge transfer resistance of sprGO are quantitatively measured, and the actual amount of immobilized GOx and the performance of EBFC using this catalyst are electrochemically examined. With this, it is found that the amount of GOx immobilized in sprGO/[TTF-GOx]/crosslinked-gelatin is twice better that in rGO/[TTF-GOx]/crosslinked-gelatin. More specifically, EBFC using this catalyst shows open circuit voltage of 0.85 V and maximum power density of 380 μW/cm2, and this is 1.4 times better than that using rGO/[TTF-GOx]/crosslinked-gelatin. These results indicate that the amount of immobilized GOx strongly affects the performance capabilities of EBFCs.

Mathematical modeling and dynamic Simulink simulation of high-pressure PEM electrolyzer system

PEM electrolysis based hydrogen generator system model is developed by using Simulink in MATLAB. The model covers the following system components: PEM electrolyzer stack, water pump, cooling fan, storage tank, water tank, power supply, control unit and sensors. In simulation, PEM electrolyzer stack model is the most complex component and consists of four parts; anode and cathode modules, membrane and finally voltage calculations module. Efficiency drops and voltage losses in the PEM electrolysis stack are estimated. The overpotentials are investigated as anode and cathode activation, electronic and ionic ohmic resistances. In addition, the loss of the other components is considered. The model is tested against the dynamic changes and it responded with quick outputs. The cell and stack behavior under different conditions (i.e. ranging of temperature and pressure) are examined. The loss of each system component at different current densities is added to the simulation. The study shows that the loss of stack dominates the losses of other components at higher current densities. The simulation counts that the stack and system model can run with different cases and scenarios. It is run for the scenario that it consumes constant power for a high pressure operation. Results show that current drawn by the stack decreases as the voltage increases because of the increasing pressure.The model is also compared with the experimental results and the model is found to be consistent with the experimental data.

Solid-phase extraction and nanoflow liquid chromatography-nanoelectrospray ionization mass spectrometry for improved global urine metabolomics.

Global urine metabolomics is a rapidly expanding field with the potential to discover biomarkers of disease and exposure. To date, most methods focus on rapid sample preparation, using neat or diluted urine, together with high-throughput analyses, and are poorly suited for detection of low abundance metabolites present in urine samples. In this study, novel methods have been developed to analyze urine by splitless nanoflowUHPLC-nanoESI-TOFMS (nUHPLC-nESI-TOFMS) after preconcentration by solid-phase extraction (SPE), thus enabling significant improvements in analytical sensitivity and coverage of the urinary metabolome. In initial work, urine samples were extracted by both anion and cation exchange mixed-mode polymeric SPE cartridges and qualitatively compared with those using conventional sample preparations using UHPLC-ESI-TOFMS analyses. Compared with neat or diluted urine samples, SPE concentration of urine resulted in detection of additional metabolites including bile acids, lipids, pharmaceuticals, and markers of lifestyle, with little loss of other components of the metabolome. Analyses of SPE preparations by nUHPLC-nESI-TOFMS revealed excellent retention time repeatability with <1% coefficient of variation (CV) for 96% of analyzed peaks. The repeatability of the MS response was <30% CV for >79% of MS features in both negative and positive nESI modes. Compared with UHPLC-ESI-TOFMS, analysis by the nanoplatform enabled detection of signaling molecules important in disease processes including sex steroids, glucocorticoids, eicosanoids, and neurotransmitter metabolites. The significant improvement in sensitivity arising from use of splitless nUHPLC-nESI-TOFMS analyses of SPE-concentrated samples represents a step change in coverage of the urinary metabolome, thereby increasing the potential for biomarker discovery.

High-Quality-Factor Active Capacitors for Millimeter-Wave Applications

This paper presents single-ended and differential configurations of active capacitors that exhibit high-quality (Q) factor at millimeter-wave frequencies. Both structures provide a small tunable negative resistance that can be exploited to compensate for the loss of other components, such as inductors in millimeter-wave integrated circuits. Unlike passive capacitors, which exhibit increasing capacitance with frequency (due to the inductive parasitic), the proposed active capacitors display relatively frequency-independent values. Fabricated in 0.13-μm IBM CMOS, tunable Q values of more than 20 are obtained at 60 GHz. A 40-GHz bandpass filter is designed and fabricated using the single-ended active capacitor cells in a 0.13-μm IBM CMOS process exhibiting 0-dB insertion loss.

Isolation of incubation chambers during brooding: effect of reduced pH on protoconch development in the estuarine gastropod Crepipatella dilatata (Calyptraeidae)

The sedentary gastropod Crepipatella dilatata encapsulates its embryos and incubates them in the pallial cavity. Females can deliberately isolate their embryos from the external environ- ment for many hours at a time by pressing their shells tightly against the substrate. We documented the effects of such isolation on pH in the pallial cavity and the effects of reduced pH on changes in shell thickness and the proportion of calcium in embryonic shells. We also quantified the concen- tration of calcium in the water retained in the pallial cavity during isolation, as well as the growth of encapsulated veligers. Average protoconch thickness decreased by as much as 50% at reduced pH (pH = 6 to 3). During 24 h of exposure to water at the different pHs, calcium was lost from shells, but in same proportion as the loss of other components. Calcium in the pallial fluid increased during the first 5 h of isolation for both brooding and non-brooding females, suggesting shell dissolution. The calcium content of pallial cavity fluid for brooding females differed from that of non-brooding females, but did not differ from that in the intracapsular fluid, suggesting that calcium diffuses freely through the egg capsule wall. Isolation of the incubatory chamber impeded embryonic shell growth, possibly because the calcium was acting as a 'buffer' to regulate pH changes in the pallial fluid. The isolation of embryos by incubating females, usually viewed as an adaptive benefit of brood- ing, can cause pronounced negative effects on embryonic development during the period of shell formation.

Oscillating Taylor-Couette flow (azimuthal motion)

It has been attempted to inject the energy directly into a higher mode in a rotating Taylor-Couette system by oscillation of inner cylinder. The earlier investigation on the axial and radial velocity components revealed a dip in the excitation function which indicates a energy loss. In contrary, the azimuthal velocity component shows an increase in its excitation curve, which implies a compensation of the energy loss of other components and indicates a possible energy injection into the WVF mode which is a higher mode than TVF mode.

MASK, a large ankyrin repeat and KH domain-containing protein involved in Drosophila receptor tyrosine kinase signaling.

The receptor tyrosine kinases Sevenless (SEV) and the Epidermal growth factor receptor (EGFR) are required for the proper development of the Drosophila eye. The protein tyrosine phosphatase Corkscrew (CSW) is a common component of many RTK signaling pathways, and is required for signaling downstream of SEV and EGFR. In order to identify additional components of these signaling pathways, mutations that enhanced the phenotype of a dominant negative form of Corkscrew were isolated. This genetic screen identified the novel signaling molecule MASK, a large protein that contains two blocks of ankyrin repeats as well as a KH domain. MASK genetically interacts with known components of these RTK signaling pathways. In the developing eye imaginal disc, loss of MASK function generates phenotypes similar to those generated by loss of other components of the SEV and EGFR pathways. These phenotypes include compromised photoreceptor differentiation, cell survival and proliferation. Although MASK is localized predominantly in the cellular cytoplasm, it is not absolutely required for MAPK activation or nuclear translocation. Based on our results, we propose that MASK is a novel mediator of RTK signaling, and may act either downstream of MAPK or transduce signaling through a parallel branch of the RTK pathway.

Chimeric probe‐mediated ribonuclease protection assay for molecular diagnosis of mRNA deficiencies

Investigations throughout the last decade have established that cytoskeleton integrity ensures red cell deformability and mechanical stability, and that defects in one of the skeletal components usually result in more or less severe hemolytic anemias. Although a large number of molecular defects have been identified to date, many others still bypass fast and commonly used methods, such as SSCP and DGGE, mostly because of a subtle change in mRNA transcription level or a complex interaction leading to the loss of other components. We describe a ribonuclease protection assay based on a simultaneous quantification of two cytoskeletal transcripts, using a chimeric probe, emphasizing the value of a nonspecific bridging sequence, inserted between the two specific probe sequences. It is anticipated that this powerful and reliable procedure would be an additional tool in the methodology array used for screening cytoskeletal inherited abnormalities. © 1996 Wiley-Liss, Inc.

Chimeric probe-mediated ribonuclease protection assay for molecular diagnosis of mRNA deficiencies

Investigations throughout the last decade have established that cytoskeleton integrity ensures red cell deformability and mechanical stability, and that defects in one of the skeletal components usually result in more or less severe hemolytic anemias. Although a large number of molecular defects have been identified to date, many others still bypass fast and commonly used methods, such as SSCP and DGGE, mostly because of a subtle change in mRNA transcription level or a complex interaction leading to the loss of other components. We describe a ribonuclease protection assay based on a simultaneous quantification of two cytoskeletal transcripts, using a chimeric probe, emphasizing the value of a nonspecific bridging sequence, inserted between the two specific probe sequences. It is anticipated that this powerful and reliable procedure would be an additional tool in the methodology array used for screening cytoskeletal inherited abnormalities.

Structural studies on the acidic polysaccharide of Bacillus cereus AHU 1356 cell walls

Structural studies were carried out on the acidic polymer fraction isolated from lysozyme digests of the N-acetylated cell walls of Bacillus cereus AHU 1356. The acidic polymer fraction contained glucosamine, galactose, rhamnose, glycerol and phosphorus in a molar ratio of 1:1:2:1:1, together with small amounts of glycopeptide components and muramic acid 6-phosphate. The hydrogen fluoride treatment led to removal of glycerol and phosphorus from the polymer without loss of other components. Results of the NaIO4 oxidation, methylation and proton magnetic resonance spectroscopy of the native and dephosphorylated preparations, in combination with data of the analysis of oligosaccharides obtained from partial hydrolysis of polysaccharide, led to the most likely structure of the repeating units of the acidic polysaccharide chain, ----4)N-acetylglucosaminyl-(alpha 1----3)rhamnosyl(alpha 1----3)galactosyl(alpha 1----4)[sn-glycerol 1-phospho-2]rhamnosyl(alpha 1----.