Buffer Reservoir Research Articles

Passive laser power stabilization in a broadband noise spectrum via a second-harmonic generator.

An extremely conspicuous passive power noise stabilization is the first, to the best of our knowledge, discovered in a cavity-enhanced second-harmonic generation (SHG) process. Differing from the SHG as a buffer reservoir, the stronger strength of the nonlinear interaction pushes the power noise suppression level to a higher value and exhibits a broadband noise reduction performance due to the mechanism of dynamic pump suppression in the SHG process. The noise is suppressed to near shot noise limit (SNL) among the kHz to MHz frequency range, accompanied by a maximum noise reduction of 35 dB. A comprehensive demonstration indicates that the nonlinear interaction has no function on the phase noise of fundamental and harmonic waves. A theoretical model is also established that is consistent well with the experimental results. The methodology is beneficial to multiple optical metrology experiments.

Sb/As immobilization and soil function improvement under the combined remediation strategy of modified biochar and Sb-oxidizing bacteria at a smelting site

Antimony (Sb) and arsenic (As) lead to soil pollution and structural degradation at Sb smelting sites. However, most sites focus solely on Sb/As immobilization, neglecting the restoration of soil functionality. Here, we investigated the effectiveness of Fe/H2O2 modified biochar (Fe@H2O2-BC) and Sb-oxidizing bacteria (Bacillus sp. S3) in immobilizing Sb/As and enhancing soil functional resilience at an Sb smelting site. Over a twelve-month period, the leaching toxicity of As and Sb was reduced to 0.05 and 0.005 mg L−1 (GB3838–2002) respectively, with 1% (w/w) Fe@H2O2-BC and 2% (v/v) Bacillus sp. S3 solution. Compared to CK, the combination of Fe@H2O2-BC and Bacillus sp. S3 significantly reduced the bioavailable As/Sb by 98.00%/93.52%, whilst increasing residual As and reducible Sb fractions by 210.31% and 96.51%, respectively. The combined application generally improved soil aggregate structure, pore characteristics, and water-holding capacity. Fe@H2O2-BC served as a pH buffer and long-term reservoir of organic carbon, changing the availability of carbon substrates to bacteria. The inoculation of Bacillus sp. S3 facilitated the transformation of Sb(III)/As(III) to Sb(V)/As(V) and differentiated the composition and functional roles of bacterial communities in soils. The combination increased the abundance of soil saprotrophs by 164.20%, whilst improving the relative abundance of N- and S-cycling bacteria according to FUNGuild and FAPROTAX analysis. These results revealed that the integrated application was instrumental in As/Sb detoxification/immobilization and soil function restoration, which demonstrating a promising microbially-driven ecological restoration strategy at Sb smelting sites.

Stochastic Sequential Model Predictive Control for Operating Buffer Reservoir in Hjartdøla Hydropower System under Uncertainty

Stochastic Sequential Model Predictive Control for Operating Buffer Reservoir in Hjartdøla Hydropower System under Uncertainty

Micro-extraction, pre-concentration, and microfluidic-based separation of organophosphate insecticides followed by the miniaturized electrochemical detection system

Introduction: A new analytical method based on the coupling of microextraction and microfluidics was developed and investigated for the pre-concentration, separation, and electrochemical detection of fenitrothion (FT) and parathion (PA) at the sub-ppm concentrations. Method: In the first step, the microchip capillary electrophoresis technique was used to serve as a separation and detection system. Analytes were injected into the 40 mm long microchannel with 10 mm sidearms. Then, they were separated by applying a direct electrical field (+1800V) between buffer and detection reservoirs. 2-(n-morpholino)ethanesulfonic acid (MES) buffer (20 mM, pH 5) was used as the running buffer. The electrochemical detection was performed using three Pt microelectrodes with the width of working, counter, and reference electrodes (50, 250, and 250 µm, respectively) in the out channel approach. Results: The system was devised to have the optimum detection potential equal to -1.2 V vs. Pseudo Ref. electrode. The dimensions of the SU-8 channel have 20 µm depth and 50 µm width. In the second step, an air-assisted liquid-liquid microextraction technique was used for the extraction and preconcentration of analytes from human blood plasma. Then, 1, 2 di-bromoethan was used as extractant solvent, the analytes were preconcentrated, and the sedimented solvent (50 µL) was evaporated in a 60 ˚C water bath followed by substitution of running buffer containing 10% ethanol. The optimum extraction cycles were found 8 with adding 1% NaCl to the aqueous phase. Analyzing time of the mentioned analytes was less than 100s, and the precision range was 3.3 – 8.2 with the linear range of 0.8 – 100 ppm and 1.2 - 100 ppm for FT and PA, respectively. The extraction recoveries were about 91% and 87% for FT and PA, respectively. The detection limits for FT and PA were 240 and 360 ppb, respectively. Finally, the reliability of the method was investigated by GC-FID. Conclusion: The proposed method and device were validated and can be used as in situ and portable detection system for detecting fenitrothion and parathion insecticides.

A Microfluidic Platform with an Embedded Miniaturized Electrochemical Sensor for On-Chip Plasma Extraction Followed by In Situ High-Sensitivity C-Reactive Protein (hs-CRP) Detection.

Blood testing is a clinical diagnostic tool to evaluate physiological conditions, the immune system response, or the presence of infection from whole blood samples. Although conventional blood testing can provide rich biological information, it usually requires complicated and tedious whole blood processing steps operated by benchtop instruments and well-experienced technicians, limiting its usage in point-of-care (POC) settings. To address the above problems, we propose a microfluidic platform for on-chip plasma extraction directly from whole blood and in situ biomarker detection. Herein, we chose C-reactive protein (CRP) as the target biomarker, which can be used to predict fatal cardiovascular disease (CVD) events such as heart attacks and strokes. To achieve a rapid, undiluted, and high-purity on-chip plasma extraction, we combined two whole blood processing methods: (1) anti-D immunoglobulin-assisted sedimentation, and (2) membrane filtration. To perform in situ CRP detection, we fabricated a three-dimensional (3D) microchannel with an embedded electrochemical (EC) sensor, which has a modular design to attach the blood collector and buffer reservoir with standard Luer connectors. As a proof of concept, we first confirmed that the dual plasma extraction design achieved the same purity level as the standard centrifugation method with smaller sample (100 µL of plasma extracted from 400 µL of whole blood) and time (7 min) requirements. Next, we validated the functionalization protocol of the EC sensor, followed by evaluating the detection of CRP spiked in plasma and whole blood. Our microfluidic platform performed on-chip plasma extraction directly from whole blood and in situ CRP detection at a 0.1-10 μg/mL concentration range, covering the CVD risk evaluation level of the high-sensitivity CRP (hs-CRP) test. Based on the above features, we believe that this platform constitutes a flexible way to integrate the processing of complex samples with accurate biomarker detection in a sample-to-answer POC platform, which can be applied in CVD risk monitoring under critical clinical situations.

THE ANALYSIS OF THE DNIESTER RIVER HIGH WATER REGIME (WITHIN THE IVANO-FRANKIVSK AND TERNOPIL REGIONS)

The Dniester is one of the main cross-border rivers of Eastern Europe. It originates from a source in a forest located in the Ukrainian Carpathians and flows into the Black Sea. The total length of the Dniester River is 1,350 kilometers, and the area of the basin is more than 72,000 square kilometers.
 The geological structure of the Dniester basin is complex. In some sections, the channel cuts through rocks of different ages and origins.
 One of the characteristic features of the Dniester hydrographic network is the absence of large tributaries and the presence of a significant number of small ones. More than 14 thousand tributaries up to 10 km long. There are also 65 reservoirs and more than three thousand ponds in the Dniester basin. In Ukraine, a hydropower complex has been created from the main and buffer reservoirs and a bulk reservoir on the Dniester. The construction of reservoirs in the Dniester hydropower complex significantly changed the ecological situation in the basin, acting as a barrier to the entry of pollutants in the lower reaches of the river.
 The average flow of water in the lower reaches of the Dniester is 311 cubic meters per second, and the average volume of annual runoff is about 10 cubic kilometers. About 60% of the river's annual runoff falls on the summer-autumn period, 25% on the spring period due to snow melting, and 15% on the winter period, which forms mainly through the soil nourishment of the river.
 The Dniester belongs to the number of rivers whose water regime is well studied. Observations of the river's water level began as early as 1850. At different times, up to 30 hydrological stations functioned on the Dniester.
 A characteristic feature of the Dniester is the high water regime. Every year, up to 5 high waters are observed on the river, during which the water level can rise by 3-4 meters, and sometimes even more. The largest amplitude of the water level fluctuations – up to 9–10 meters – can be observed at the Zalischyky post above the Dniester Reservoir. Maximum water flows pass through the Dniester in both spring and summer, but high water flows are much higher than flood flows.
 Floods and high waters are not uncommon in the Ukrainian Carpathians, where the Dniester River originates. Catastrophic high waters in the Carpathians occur once every 30-40 years. Since the beginning of systematic hydrological observations on the Dniester, such high waters have been recorded in 1941, 1969 and 2008. For example, at the Zalischyky post in the Dniester basin, the maximum water flow was 8040 m3/s in September 1941, 5450 m3/s in June 1969, and 5410 m3/s in July 2008. However, at many hydrological stations (Strilky, Sambir, Halych, Nyzhniv, Mohyliv-Podilskyi), it was the last high water that was the highest.
 A comparison of the characteristics of high waters in June 1969 and July 2008 allows us to conclude that they were formed under similar synoptic conditions, in the presence of a stationary cyclone over the central and southern regions of the Carpathians, which was characterized by high moisture saturation and a developed system of fronts.
 In both cases, a few days before the beginning of the high water formation, intense precipitation was observed, which reduced the water-regulating capabilities of the forest.
 Thus, it can be argued that the high water of 2008 is comparable to the high water of 1969.
 However, there are some differences. In particular, the feature of the high water in 2008 was not only a significant rise in the water level, but also the high speed of its formation. In three and a half days, the water level in the Dniester rose by more than 6 m.
 The 2008 high water caused significant flooding, which could have been even greater without the Dniester Reservoir, which acted as flood control.
 For the period of 2010-2021, the years 2010 and 2020 can be noted for their high water level. In these years, high waters due to rainfall were observed on the Dniester, which caused significant material damage, which makes high water forecasting important.
 Key words: high water, high water regime, natural hydrological phenomenon, maximum water level values.

Increased hydropower production and hydropeaking mitigation along the Upper Inn River (Tyrol, Austria) with a combination of buffer reservoirs, diversion hydropower plants and retention basins

AbstractResearch on hydropeaking in Austria started in the 1990s and the implementation of the WFD stipulated large research projects since the year 2009. The first research projects supported the process understanding and in a second investigation step, measures were evaluated. The mountains in the region of Tyrol create large heads and thus support the production of flexible energy. In this region, TIWAG is operating 9 large (>10 MW) and 27 small (<10 MW) hydropower plants, with an installed capacity of about 1,550 MW and a mean annual production of 3,000 GWh. As the governmental energy strategy foresees an extension of the hydropower production in Austria, suitable options were selected in 2004 by TIWAG and the water management framework plan for Western Tyrol was developed. This strategic planning instrument proposes five large power plants, with a generation of 1,800 GWh/year of renewable energy, which enables to reach the WFD targets, because the concept includes hydropeaking mitigation by combining buffer reservoirs (impoundments), diversion hydropower plants, and retention basins. We present our promising concept of hydropeaking mitigation and exemplify this based on the GKI, a hydropeaking diversion hydropower plants (HPP) at the Swiss/Austrian border as well as the Silz hydropeaking retention basin, with a volume of about 300,000 m3. As the presented case studies are the largest measures for hydropeaking mitigation being currently implemented in Central Europe, they have pilot‐character. Thus, ongoing research and monitoring programs are expected to improve the knowledge about hydropeaking mitigation.

Plastic microchip mediated coupling of capillaries for flow pinched sample injection and consecutive electrophoretic analysis

Capillary electrophoresis (CE) is a powerful separation tool for multicomponent analysis, but the necessity of switching the inlet end of the capillary between the vials of sample and running buffer for the sample injection complicates the operation and contributes to the irreproducibility, leading to poor compatibility with on-line analysis. Herein, coupling of capillaries with the aid of a plastic microchip was achieved for consecutive analysis. An assembly of 3 pieces of capillary with a cyclic olefin copolymer (COC) microchip was fabricated by thermal bonding of the COC plates with capillaries embedded in the micro-grooves with a cross-type configuration. Two capillaries acted as a sampling channel and the third capillary was used for separation. A buffer reservoir was installed on the microchip, which connected to the joint of the capillaries. The relative liquid levels of this reservoir and the vials at the other ends of the capillaries determine the length of the sample plug. With this assembly, the RSD of peak height and peak area for consecutive analysis were 0.54 % and 2.27 % (n = 9), the sample carryover was less than 0.32 %. The applicability of the device was confirmed by monitoring the leaching process of K+ in a green tea and vitamin C effervescent tablets.

Preparation of hierarchical porous carbon by pyrolyzing sargassum under microwave: The internal connection between structure−oriented regulation and performance optimization of supercapacitors

To find an effective correlation between the preparation process and the application performance of symmetric supercapacitors, the relationship between the structural characteristics of biomass porous carbon and the electrochemical performances of supercapacitors was studied. Based on a response surface experimental design, the pore structure of biochar produced by the microwave pyrolysis of sargassum was adjusted through the collaborative optimization of key parameters, and graded sargassum porous carbon (SPC) with different pore characteristics was successfully prepared. Three representative samples, SPC−1, SPC−2, and SPC−3, were selected by systematically exploring the effects of the specific surface area (SSA), pore volume (Vtotal), and pore size distribution on the electrochemical performances. The SSA and Vtotal values of SPC−1 were 1500.50 m2 g−1 and 1.0513 cm3 g−1, respectively. The large number of micropores provided space for electronic storage, allowing it to have an excellent electronic storage capacity. The SSA of SPC−2 was 2019.90 m2 g−1, and Vtotal was 1.2241 cm3 g−1. The rich micropores resulted in a good charge–discharge rate. The SSA of SPC−3 was as high as 2103.20 m2 g−1, and Vtotal was 1.4756 cm3 g−1. The micron−level mesopores between the SPC−3 carbon skeletons acted as ion buffer reservoirs to shorten the ion diffusion distance and produce excellent rate performances. Subsequently, the morphology and surface properties of porous carbon samples were characterized. The study revealed that hierarchical porous carbon materials with excellent properties must achieve a balance of the microstructure and surface properties and their influence on the electrochemistry. A higher degree of graphitization could bring about a high pore regularity, thereby optimizing the ion transport kinetics. Heteroatoms could increase redox active surface sites and provide additional pseudocapacitance, but the resulting defect structure formed a large number of pores with high edge roughness in the carbon material, which had a certain negative impact on the capacity properties of the materials. The above findings can provide technical support and a theoretical basis for controlling the pore networks and directionally optimizing the performances of supercapacitors by adjusting the pore structure of biochar.

Enhancement of Li+ ion kinetics in boehmite nanofiber coated polypropylene separator in LiFePO4 cells

Boehmite (γ-AlO(OH)) nanofibers (length 90–140 ​nm; dia. ∼15 ​nm) synthesized by low temperature (180 ​°C) hydrothermal method and coated onto both sides of surface modified polypropylene. Ceramic coated composite separator (ALO-PP) shows enhanced thermal and dimensional stability over uncoated polypropylene (PP). Optimum coating thickness is found to be 8 ​μm in each side. Electrochemical properties are investigated by assembling 2032-type coin cells using LiFePO4 as cathode against Li/Li+ in half-cell and Mesocarbon microbeads (MCMB) in full-cell configuration respectively. It is found that composite separator results in improved cell kinetics due to better electrolyte uptake and formation of a Li+ ions buffer reservoir facilitating fast ion transport at high current rates. About 16% higher capacity is observed for ALO-PP over PP at a current rate of C/5. Present results show that nanostructured boehmite could be a promising coating material for surface modification of polyolefin separators not only with improved safety but also with enhanced rate performance.

Model based optimization of a novel ventricular assist device

Abstract This paper presents an optimization-based control scheme for a novel left ventricular assist device. This cardiac support system consists of two pumps connected in series and a buffer reservoir in between them. This novel concept for relieving the left ventricle is designed to allow the pre- and afterload on the heart to be explicitly adjusted and independently of each other. The first pump controls the preload of the heart with a known physiological controller. With an iterative model-based optimization, the afterload is minimized by the second pump while complying with all constraints. The proof of the control concept and a comparison to the classical single pump left-sided cardiac support is performed on a hardware-in-the-loop test bench. The results show that with the new left ventricular assist device concept, the afterload can be reduced compared to the classical cardiac support.

Nucleic acid sample preparation from whole blood in a paper microfluidic device using isotachophoresis

Nucleic acid amplification tests (NAATs) are a crucial diagnostic and monitoring tool for infectious diseases. A key procedural step for NAATs is sample preparation: separating and purifying target nucleic acids from crude biological samples prior to nucleic acid amplification and detection. Traditionally, sample preparation has been performed with liquid- or solid-phase extraction, both of which require multiple trained user steps and significant laboratory equipment. The challenges associated with sample preparation have limited the dissemination of NAAT point-of-care diagnostics in low resource environments, including low- and middle-income countries. We report on a paper-based device for purification of nucleic acids from whole blood using isotachophoresis (ITP) for point-of-care NAATs. We show successful extraction and purification of target nucleic acids from large volumes (33 µL) of whole human blood samples with no moving parts and few user steps. Our device utilizes paper-based buffer reservoirs to fully contain the liquid ITP buffers and does not require complex filling procedures, instead relying on the natural wicking of integrated paper membranes. We perform on-device blood fractionation via filtration to remove leukocytes and erythrocytes from our sample, followed by integrated on-paper proteolytic digestion of endogenous plasma proteins to allow for successful isotachophoretic extraction. Paper-based isotachophoresis purifies and concentrates target nucleic acids that are added directly to recombinase polymerase amplification (RPA) reactions. We show consistent amplification of input copy concentrations of as low as 3 × 103 copies nucleic acid per mL input blood with extraction and purification taking only 30 min. By employing a paper architecture, we are able to incorporate these processes in a single, robust, low-cost design, enabling the direct processing of large volumes of blood, with the only intermediate user steps being the removal and addition of tape. Our device represents a step towards a simple, fully integrated sample preparation system for nucleic acid amplification tests at the point-of-care.

Inorganic oxidizer detection from propellants, pyrotechnics, and homemade explosive powders using gradient elution moving boundary electrophoresis

Advancement in rapid targeted chemical analysis of homemade and improvised explosive devices is critical for the identification of explosives-based hazards and threats. Gradient elution moving boundary electrophoresis (GEMBE), a robust electrokinetic separation technique, was employed for the separation and detection of common inorganic oxidizers from frequently encountered fuel-oxidizer mixtures. The GEMBE system incorporated sample and run buffer reservoirs, a short capillary (5cm), an applied electric field, and a pressure-driven counterflow. GEMBE provided a separation format that allowed for continuous injection of sample, selectivity of analytes, and no sample cleanup or filtration prior to analysis. Nitrate, chlorate, and perchlorate oxidizers were successfully detected from low explosive propellants (e.g., black powders and black powder substitutes), pyrotechnics (e.g., flash powder), and tertiary explosive mixtures (e.g., ammonium nitrate- and potassium chlorate-based fuel-oxidizer mixtures). Separation of these mixtures exhibited detection without interference from a plethora of additional organic and inorganic fuels, enabled single particle analysis, and demonstrated semiquantitative capabilities. The bulk counterflow successfully excluded difficult components from fouling the capillary, yielding estimated limits of detection down to approximately 10μmol/L. Finally, nitrate was separated and detected from postblast debris collected and directly analyzed from two nitrate-based charges.

Sulfur Transport and Metabolism in Legume Root Nodules.

Sulfur is an essential nutrient in plants as a constituent element of some amino acids, metal cofactors, coenzymes, and secondary metabolites. Not surprisingly, sulfur deficiency decreases plant growth, photosynthesis, and seed yield in both legumes and non-legumes. In nodulated legumes, sulfur supply is positively linked to symbiotic nitrogen fixation (SNF) and sulfur starvation causes three additional major effects: decrease of nodulation, inhibition of SNF, and slowing down of nodule metabolism. These effects are due, at least in part, to the impairment of nitrogenase biosynthesis and activity, the accumulation of nitrogen-rich amino acids, and the decline in leghemoglobin, ferredoxin, ATP, and glucose in nodules. During the last decade, some major advances have been made about the uptake and metabolism of sulfur in nodules. These include the identification of the sulfate transporter SST1 in the symbiosomal membrane, the finding that glutathione produced in the bacteroids and host cells is essential for nodule activity, and the demonstration that sulfur assimilation in the whole plant is reprogrammed during symbiosis. However, many crucial questions still remain and some examples follow. In the first place, it is of paramount importance to elucidate the mechanism by which sulfur deficiency limits SNF. It is unknown why homoglutahione replaces glutathione as a major water-soluble antioxidant, redox buffer, and sulfur reservoir, among other relevant functions, only in certain legumes and also in different tissues of the same legume species. Much more work is required to identify oxidative post-translational modifications entailing cysteine and methionine residues and to determine how these modifications affect protein function and metabolism in nodules. Likewise, most interactions of antioxidant metabolites and enzymes bearing redox-active sulfur with transcription factors need to be defined. Solving these questions will pave the way to decipher sulfur-dependent mechanisms that regulate SNF, thereby gaining a deep insight into how nodulated legumes adapt to the fluctuating availability of nutrients in the soil.

In situ synthesis of mesoporous Co3O4 nanorods anchored on reduced graphene oxide nanosheets as supercapacitor electrodes

In situ synthesis of mesoporous Co3O4 nanoparticles embedded in reduced graphene oxide nanosheets (GNSs) was implemented through coprecipitation method and pyrolytic process. In the charge-discharge process, electrolyte ions can fill with three-dimensional GNS matrix with connected pore network structures and mesoporous Co3O4 nanoparticles with uniform nanoscale structures as double ion buffer reservoirs. The capacitance value of Co3O4/GNS nanocomposites is 1085.6 F g−1 at the current density of 2 A g−1 in 2 M KOH solution. The composite has good cyclic stability, and the maximum capacitance loss is only 17.3% in 10,000 successive cycles.

A new sequential injection analysis-capillary electrophoresis system with amperometric detection.

A novel and fully automated sequential injection analysis manifold coupled to a capillary electrophoresis apparatus with amperometric detection, is described. The sequential injection manifold was isolated from the high voltage by inserting an air plug into the circuit. Small buffer reservoirs were used to avoid the need to pump fresh buffer to the interface during the electrophoretic separation. No decoupling device was used to mitigate the interference from the high voltage electric field, instead the potential shift induced by the separation voltage, was accounted for. The new hydrodynamic injection method presented is based on the overpressure created in the circuit when a pinch valve is closed for a predetermined time. The injection method yields RSD values of peak height and area below 2.55 and 1.82%, respectively, at different durations of valve closure (n=5). The capillary and working electrode alignment was achieved by adapting a commercial available capillary union. When the electrode was replaced, the alignment method proved to be very reliable, yielding RSD values of peak height and area lower than 2.64 and 2.08%, respectively (n=8). Using this system with a gold microelectrode, dopamine, and epinephrine could be quantified within the concentration range of 1-500 μM and detected at a concentration of 0.3 μM. The methods here presented could be applied for the development of new capillary electrophoresis systems with amperometric detection and/or to the design of fully automated systems for online process monitoring purposes.

Transparent Nanopore Cavity Arrays Enable Highly Parallelized Optical Studies of Single Membrane Proteins on Chip.

Membrane proteins involved in transport processes are key targets for pharmaceutical research and industry. Despite continuous improvements and new developments in the field of electrical readouts for the analysis of transport kinetics, a well-suited methodology for high-throughput characterization of single transporters with nonionic substrates and slow turnover rates is still lacking. Here, we report on a novel architecture of silicon chips with embedded nanopore microcavities, based on a silicon-on-insulator technology for high-throughput optical readouts. Arrays containing more than 14 000 inverted-pyramidal cavities of 50 femtoliter volumes and 80 nm circular pore openings were constructed via high-resolution electron-beam lithography in combination with reactive ion etching and anisotropic wet etching. These cavities feature both, an optically transparent bottom and top cap. Atomic force microscopy analysis reveals an overall extremely smooth chip surface, particularly in the vicinity of the nanopores, which exhibits well-defined edges. Our unprecedented transparent chip design provides parallel and independent fluorescent readout of both cavities and buffer reservoir for unbiased single-transporter recordings. Spreading of large unilamellar vesicles with efficiencies up to 96% created nanopore-supported lipid bilayers, which are stable for more than 1 day. A high lipid mobility in the supported membrane was determined by fluorescent recovery after photobleaching. Flux kinetics of α-hemolysin were characterized at single-pore resolution with a rate constant of 0.96 ± 0.06 × 10-3 s-1. Here, we deliver an ideal chip platform for pharmaceutical research, which features high parallelism and throughput, synergistically combined with single-transporter resolution.

Analytical modeling of dual-frequency solid-state lasers including a buffer reservoir for noise cancellation.

A theoretical model describing the dynamical behavior of dual-frequency solid-state lasers including a buffer reservoir (BR) is presented. It relies on the introduction of two additional coupled rate equations describing the interaction of the two laser modes with the BR. The relative intensity noise is derived by taking into account the fluctuations of both pump intensity and intra-cavity photons. This modelling approach accurately predicts the experimental noise spectra obtained with an Er,Yb:glass dual-frequency laser implemented in different cavity architecture configurations. The mode coupling strength in the BR is shown to rule the reduction efficiency of the excess noise lying at the in-phase and anti-phase frequencies.

Development of a sheathless CE-ESI-MS interface.

A sheath-flow interface is the most common ionization technique in CE-ESI-MS. However, this interface dilutes the analytes with the sheath liquid and decreases the sensitivity. In this study, we developed a sheathless CE-MS interface to improve sensitivity. The interface was fabricated by making a small crack approximately 2cm from the end of a capillary column fixed on a plastic plate, and then covering the crack with a dialysis membrane to prevent metabolite loss during separation. A voltage for CE separation was applied between the capillary inlet and the buffer reservoir. Under optimum conditions, 52 cationic metabolite standards were separated and selectively detected using MS. With a pressure injection of 5kPa for 15s (ca. 1.4nL), the detection limits for the tested compounds were between 0.06 and 1.7μmol/L (S/N = 3). The method was applied to analysis of cationic metabolites extracted from a small number (12000) of cancer cells, and the number of peaks detected was about 2.5 times higher than when using conventional sheath-flow CE-MS. Because the interface is easy to construct, it is cost-effective and can be adapted to any commercially available capillaries. This method is a powerful new tool for highly sensitive CE-MS-based metabolomic analysis.

Accelerated Irrigation Canal Flow Change Routing

AbstractIn a traditional automated upstream controlled canal with a downstream buffer reservoir, the process to fill the buffer reservoir requires one step: the inflow to the canal is increased, an...