Reservoir Chamber Research Articles

Picotesla optically pumped magnetometer using a laser-written vapor cell with sub-mm cross section

We demonstrate a sensitive optically pumped magnetometer using rubidium vapor and 0.75 amg of nitrogen buffer gas in a sub-mm-width sensing channel excavated by femtosecond laser writing followed by chemical etching. The channel is buried less than 1 mm below the surface of its fused silica host material, which also includes reservoir chambers and micro-strainer connections, to preserve a clean optical environment. Using a zero-field-resonance magnetometry strategy and a sensing volume of 2.25 mm3, we demonstrate a sensitivity of ≈1pT/Hz at 10 Hz. The device can be integrated with photonic structures and microfluidic channels with 3D versatility. Its sensitivity, bandwidth, and stand-off distance will enable detection of localized fields from magnetic nanoparticles and μL NMR samples.

A hydrate reservoir renovation device and its application in nitrogen bubble fracturing

Abstract. Natural gas hydrate (GH) is a significant potential energy source due to its large reserves, wide distribution, high energy density, and low pollution. However, the gas production rate of past gas hydrate production tests is much lower than the requirement of commercial gas production. Reservoir stimulation technologies like hydraulic fractures provide one potential approach to enhance gas production from GH. The reservoir reformation behavior of the hydrate-bearing sediments (HBSs), particularly sediments with a high clay content, is a complex process during a hydraulic fracturing operation which has been poorly understood and thus hardly predictable. This paper presents an experimental facility that was developed to analyze the hydraulic fracture mechanism in synthesized HBSs. This facility can be used to form GH in sediments, conduct visual observation of hydraulic fracturing experiments, and measure the permeability of HBSs under high-pressure (up to 30 MPa) and low-temperature conditions (from 253.15 to 323.15 K). It is mainly composed of a pressure control and injection unit, a low temperature and cooling unit, a cavitation unit, a visual sapphire reactor, and a data acquisition and measurement unit. The hydraulic fracture module consists of a gas cylinder, fracturing pump, hopper, proppant warehouse, and valves. The sapphire reservoir chamber is applied to observe and measure the fracture of HBSs during hydraulic fracturing. The permeability test module is composed of a constant-flux pump and pressure sensors, which can evaluate the permeability performance before and after the hydraulic fracture in HBSs. The fundamental principles of this apparatus are discussed. Some tests were performed to verify hydraulic fracture tests, and permeability tests could be practically applied in the HBS exploitation.

Design optimization and experimental demonstration of a gravity-assisted cryogenic loop heat pipe

Cryogenic loop heat pipe (CLHP) is an efficient two-phase heat transfer device utilized for cooling electronic components within a cryogenic operating temperature range (3–220 K), such as an infrared detector and superconductive magnet. Compared with the prevalent cryogenic loop heat pipe which uses a capillary starter pump to achieve the startup, this research studied a gravity-assisted CLHP that uses gravity to achieve the startup. In this way, the configuration of gravity-assisted CLHP became simple, and the preconditioning could be achieved without consuming the extra heat load on the capillary starter pump. This proposed CLHP is intended for use in ground and space (in the gravitational environment such as the Moon and Mars). A comprehensive design method including the design optimization of the gas reservoir and compensation chamber (CC) volumes was newly established by considering the variation of vapor-liquid distribution in CC during the operating temperature range, resulting in a significant reduction of at least 40 % in the gas reservoir volume compared to conventional CLHP designs. Then the fabrication and the experimental investigation were implemented. Nitrogen was selected as the working fluid. The CLHP was designed to transport heat exceeding 20 W over a distance of 2 m within the operating temperature range of 80–110 K. Based on the experimental result, the startup was achieved, and the heat transfer performance satisfied the design requirement. Additionally, the detailed operating characteristics of the CLHP, including the gravity effect, the startup behavior, and the hysteresis phenomena that occurred in the temperature of the evaporator, pressure, and thermal resistance, were also first reported and thoroughly investigated.

Left atrial functional assessment a prime clue in solving the puzzle of stable angina symptoms in suspected coronary artery disease patients

Abstract Background Assessing clinically for significant coronary artery disease (CAD) in stable angina patients presents a formidable task. Routinely performed echocardiography is limited in diagnosing CAD with provision for the regional wall motion abnormality (RWMA) for left ventricle (LV) systolic dysfunction and altered mitral inflow velocities for LV diastolic dysfunction. However, the advent of two-dimensional (2D) speckle-tracking technique has established the era of strain imaging, opening new possibilities in echocardiography. It is now possible to have a detailed functional assessment of left atrium (LA). We utilised speckle tracking imaging to obtain strain parameters for LA function. Combining these strain parameters with the doppler myocardial velocities and mitral inflow velocities, may prove useful mode of imaging to diagnose significant CAD in stable angina patients. Purpose To study the parameters of left atrial functions utilising echocardiographic strain imaging and evaluate their correlation with the syntax score-II in patients with symptoms of stable angina. Methods 103 patients with symptoms of stable angina undergoing coronary angiography for suspected coronary artery disease(CAD), were considered for LA function assessment and compared with their syntax-II score. Results The LA reservoir function parameters, peak atrial longitudinal strain (PALS) and peak global systolic strain rate (LAsSR), decreased with increasing syntax-II score (p values 0.011 and 0.001 respectively) and the parameter of LA conduit function, peak global early diastolic strain rate (LAeSR) increased (p value <0.001). The LA filling pressures reflected by E/e`, also increased with more severe syntax-II score (p value <0.001). We, further, configured cut off values of < 23.56 for PALS, < 1.15 for LAsSR, > -1.09 for LAeSR, and E/e` ratio > 10.39 as predictors of significant CAD, with good sensitivity and specificity. Therefore, stable angina patients who had significant CAD on coronary angiogram represented by severe syntax score-II, had higher LA filling pressures and deranged LA function with transition from more of reservoir chamber to merely a conduit. Conclusion Our study shows a significant association between LA strain parameters (PALS, LAsSR, and LAeSR) and LA filling pressures (E/e`), with the presence of significant CAD in these patients. The stable angina patients with more severe CAD as quantified by their severe syntax score-II, have an impaired LA reservoir and LA functions more as a conduit, with elevated filling pressures. This study establishes a significant association between LA deformation strain variables and severity of CAD and hence LA strain imaging can be a useful tool to diagnose significant CAD in stable angina patients.

Microfluidic Distillation System for Separation of Propionic Acid in Foods.

A microfluidic distillation system is proposed to facilitate the separation and subsequent determination of propionic acid (PA) in foods. The system comprises two main components: (1) a polymethyl methacrylate (PMMA) micro-distillation chip incorporating a micro-evaporator chamber, a sample reservoir, and a serpentine micro-condensation channel; and (2) and a DC-powered distillation module with built-in heating and cooling functions. In the distillation process, homogenized PA sample and de-ionized water are injected into the sample reservoir and micro-evaporator chamber, respectively, and the chip is then mounted on a side of the distillation module. The de-ionized water is heated by the distillation module, and the steam flows from the evaporation chamber to the sample reservoir, where it prompts the formation of PA vapor. The vapor flows through the serpentine microchannel and is condensed under the cooling effects of the distillation module to produce a PA extract solution. A small quantity of the extract is transferred to a macroscale HPLC and photodiode array (PDA) detector system, where the PA concentration is determined using a chromatographic method. The experimental results show that the microfluidic distillation system achieves a distillation (separation) efficiency of around 97% after 15 min. Moreover, in tests performed using 10 commercial baked food samples, the system achieves a limit of detection of 50 mg/L and a limit of quantitation of 96 mg/L, respectively. The practical feasibility of the proposed system is thus confirmed.

Unveiling the Hidden Chamber: Exploring the Importance of Left Atrial Function and Filling Pressure in Cardiovascular Health.

The left atrium (LA) is a vital component of the cardiovascular system, playing a crucial role in cardiac function. It acts as a reservoir, conduit, and contractile chamber, contributing to optimal left ventricle (LV) filling and cardiac output. Abnormalities in LA function have been associated with various cardiovascular conditions, including heart failure, atrial fibrillation, valvular heart disease, and hypertension. Elevated left ventricular filling pressures resulting from impaired LA function can lead to diastolic dysfunction and increase the risk of adverse cardiovascular events. Understanding the relationship between LA function and LV filling pressures is crucial for comprehending the pathophysiology of cardiovascular diseases and guiding clinical management strategies. This article provides an overview of the anatomy and physiology of the LA, discusses the role of LA mechanics in maintaining normal cardiac function, highlights the clinical implications of elevated filling pressures, and explores diagnostic methods for assessing LA function and filling pressures. Furthermore, it discusses the prognostic implications and potential therapeutic approaches for managing patients with abnormal LA function and elevated filling pressure. Continued research and clinical focus on left atrial function are necessary to improve diagnostic accuracy, prognostic assessment, and treatment strategies in cardiovascular diseases. It will explore the importance of assessing LA function as a marker of cardiac performance and evaluate its implications for clinical practice. In accordance with rigorous scientific methodology, our search encompassed PubMed database. We selected articles deemed pertinent to our subject matter. Subsequently, we extracted and synthesized the salient contents, capturing the essence of each selected article.

Effect of oxygen flow on aerosol delivery from a vibrating mesh nebulizer with a holding chamber

BackgroundA holding chamber (HC) was created to work with a vibrating mesh nebulizer (VMN) to boost the total inhalable dose for patients. In addition to the optional supply of supplemental oxygen, it facilitates intermittent and continuous nebulization. Our goal was to see how well a VMN coupled to a HC with a mouthpiece or valved facemask performed at varied oxygen flows starting at 0–6 L/min. In this study, we used a breathing simulator to simulate adults' spontaneous breathing patterns with a tidal volume of 500 mL and a 1:1 inhalation–exhalation ratio. For the combination of nebulizer and HC adapter with a valved facemask or mouthpiece, five determinations were made. Salbutamol was recovered and evaluated using high-performance liquid chromatography from the inhalation filter connected to the breathing simulator, the nebulizer reservoir chamber, and the HC.ResultsThe amount of salbutamol in the nebulizer reservoir chamber and within the HC did not differ significantly when using a mouthpiece or a valved facemask. However, the supplied dose to the inhalation filter was increased until oxygen flow reached 2 and 3 L/min using the mouthpiece and valved facemask as interfaces, respectively. The supplied salbutamol was much higher at this flow than at the other oxygen flows. This was followed by a progressive reduction in the supplied salbutamol until the lowest given dose was reached at 6 L/min oxygen flow, p < 0.005.ConclusionsThe supplied doses of salbutamol to the inhalation filter were variable with the VMN connected to the HC and mouthpiece or valved facemask, with significant improvements until an oxygen flow of 2 L/min with a mouthpiece and 3 L/min with a valved facemask, followed by gradual decreases to lower values at an oxygen flow of 6 L/min. An in vivo investigation is required to further validate the findings.

Field application of a modular multiple thermal fluid generator for heavy oil recovery

A modular multiple thermal fluid generator is introduced to enhance heavy oil production, which consists of water treatment system, fuel injection system, air compressor, central burning and heat exchanging system, and measuring and controlling system. All the components are mounted in three separated light shelters, which are easy to be lifted and installed, especially on the offshore production platform. It could be operated under 350 ℃ and 20 MPa, and the temperature and GWR (ratio of the volume of gas to the equivalent water volume of steam under standard conditions) could be adjusted by the water injection rate under the given heating capability of the central burning chamber. The temperature of the generated fluid is usually 200–300 ℃ with GWR of 200–300 m3/m3. Compared to conventional steam generator, such compact multiple thermal fluid generator is easy to be installed on the offshore oil production platform, and the generated multiple thermal fluid is potential to enhance heavy oil production in mechanisms of reducing heavy oil viscosity by both heating and injected gas, enlarging the heating reservoir chamber, and pressure by injected gas. In the past 10 years, the multiple thermal fluid generator has been applied to more than 40 wells in Bohai Offshore Oilfield and Xinjiang Oilfield in cyclic multiple thermal fluid stimulation (CMTFS in short) process. As a result, the multiple thermal fluid generators were operated soundly, and the heavy oil production of these wells was enhanced remarkably. (The oil production rate was 2–3 times more than cold production.)

How to Control the Microfluidic Flow and Separate the Magnetic and Non-Magnetic Particles in the Runner of a Disc.

Biochips play an important role in both medical and food industry safety testing. Moreover, magnetic activated cell sorting is a well-established technology for biochip development. However, biochips need to be manufactured by precision instruments, resulting in the high cost of biochips. Therefore, this study used magnetic-activation and mechanics theories to create a novel disc that could manipulate the microfluidic flow, mixing, reaction, and separation on the runner of the disc. The goal of the research was to apply in the field of biomedical detection systems to reduce the cost of biochips and simplify the operation process. The simulation and experimental investigation showed that the pattern of the reaction chamber was stomach-shaped and the reservoir chamber was rectangular-shaped on the disc. The microfluid could be controlled to flow to the reaction chamber from the buffer and sample chamber when the disc spun at 175~200 rpm within three minutes. This was defined as the first setting mode. The microfluid could then be controlled to flow to the reservoir chamber from the reaction chamber when the disc spun at 225 rpm within five to ten minutes. This was defined as the second setting mode. This verified that the pattern design of the disc was optimized for control of the microfluid flow, mixing, reaction, and separation in the runner of the disc by different setting modes.

An innovative experimental apparatus for the analysis of sand production during natural gas hydrate exploitation.

Natural gas hydrate (NGH) will become a significant potential energy source in the post-oil era due to its large reserves, wide distribution, high energy density, and low pollution. Sand production is one of the main problems that cause the impossible long-term production of NGH. This paper presents an experimental apparatus that was developed to synthesize NGH and hydrate-bearing sediments and was applied to analyze the sand production and sand control mechanism during hydrate exploitation. The sand production and sand control tests of NGH can be conducted over a temperature range varying from 253.15 to 323.15K and the maximum chamber pressure and overlying pressure up to 30 MPa. This apparatus is mainly composed of the simulated sand production system, the temperature and pressure control system, and the measurement control system. The simulated sand production system consists of a movable overlying pressure loader, a strain sensor, a simulated reservoir chamber, a sand control system, and a sand production monitoring system. A visual gas-liquid-solid separation tank is applied to observe the gas, water, and sand production. The basic principles of this apparatus are discussed, and a series of experiments were performed to verify that sand production and sand control can be practically applied in the exploitation of NGH reservoirs.

Flex Printed Circuit Board Implemented Graphene-Based DNA Sensor for Detection of SARS-CoV-2.

Since the COVID-19 outbreak was declared a pandemic by the World Health Organization (WHO) in March 2020, ongoing efforts have been made to develop sensitive diagnostic platforms. Detection of viral RNA provides the highest sensitivity and specificity for detection of early and asymptomatic infections. Thus, this work aimed at developing a label-free genosensor composed of graphene as a working electrode that could be embedded into a flex printed circuit board (FPCB) for the rapid, sensitive, amplification-free and label-free detection of SARS-CoV-2. To facilitate liquid handling and ease of use, the developed biosensor was embedded with a user-friendly reservoir chamber. As a proof-of-concept, detection of a synthetic DNA strand matching the sequence of ORF1ab was performed as a two-step strategy involving the immobilization of a biotinylated complementary sequence on a streptavidin-modified surface, followed by hybridization with the target sequence recorded by the differential pulse voltammetric (DPV) technique in the presence of a ferro/ferricyanide redox couple. The effective design of the sensing platform improved its selectivity and sensitivity and allowed DNA quantification ranging from 100 fg/mL to n}{}1~mu text{g}n/mL. Combining the electrochemical technique with FPCB enabled rapid detection of the target sequence using a small volume of the sample (5-n}{}20~mu text{L}n). We achieved a limit-of-detection of 100 fg/mL, whereas the predicted value was ~33 fg/mL, equivalent to approximately n}{}5times 10^{5}n copies/mL and comparable to sensitivities provided by isothermal nucleic acid amplification tests. We believe that the developed approach proves the ability of an FPCB-implemented DNA sensor to act as a potentially simpler and more affordable diagnostic assay for viral infections in Point-Of-Care (POC) applications.

A Fast Positioning Technology for Compensation Hole of Automobile Brake Master Cylinder

The compensation hole of the automobile brake master cylinder is an important structural part for adjusting the reservoir and pressure chamber of the brake master cylinder. Its detection accuracy is strictly controlled. However, because the compensation hole is located on the inner wall of the blind hole, the existing detection method cannot meet the testing needs. Therefore, this paper introduces the SSD model into the detection of the compensation hole of the brake master cylinder, and realizes the rapid positioning of the compensation hole by means of network fine-tuning. The compensation hole positioning detection is carried out on the self-developed automobile brake master cylinder compensation hole detector. The entire detection process time is about 5s, and the positioning accuracy is high. We apply the fine-tuning SSD model to the detection of the compensation hole of automobile brake master cylinder, which replaces the traditional method based on human-computer interaction to determine the position of the compensation hole. It has better detection accuracy and faster detection speed, and lays the foundation for the subsequent detection of the size of the compensation hole.

Experimental Evaluation of Performance Characteristics of a Horizontal Copper Mesh Wick-Based Miniature Loop Heat Pipe

The ever-increasing computational power of the electronic devices accompanies a greater power dissipation. Understanding and optimization of the heat rejection systems are thus vital to ensure effective thermal management of electronic devices in an often highly confined space. This paper reports the design, development, and results of an experimental investigation of a fast responding and passive heat-rejecting copper–water-based miniature loop heat pipe (mLHP) system. The designed mLHP has a square flat-faced evaporator of 20 mm length with opposite replenishment, four extended surfaces with vapor space, a liquid reservoir or compensation chamber, fin- and tube-type condenser, and different diameter transport lines. Capillary pumping action was ensured by a composite of 100PPI copper mesh with 37% porosity and absorbent wool of 20 µm average pore size. Wick hydration was safeguarded by a 67% filling ratio of mLHP at a cold state. A decrease in thermal resistance and an increase in heat transfer coefficient for evaporation were observed. The thermal resistance of the evaporator and mLHP was 0.109–0.396 °C/W and 0.132–0.644 °C/W with an uncertainty of 3.749% and 3.744%, respectively. The heat transfer coefficient for evaporation achieved during experimentation was 6.313–23.00 kW/m2K with 0.345% uncertainty. No reverse flow of vapors and evaporator dry-out was detected. The maximum temperature sustained was 108 °C against the 205 W heat load with a 4.5-min start-up duration. These results reveal the suitability of the designed miniature loop heat pipe for the heat dissipation of electronics.

Investigation of magnetically driven passage of magnetic nanoparticles through eye tissues for magnetic drug targeting

This paper elucidates the feasibility of magnetic drug targeting to the eye by using magnetic nanoparticles (MNPs) to which pharmaceutical drugs can be linked. Numerical simulations revealed that a magnetic field gradient of 20 T m−1 seems to be promising for dragging magnetic multicore nanoparticles of about 50 nm into the eye. Thus, a targeting magnet system made of superconducting magnets with a magnetic field gradient at the eye of about 20 T m−1 was simulated. For the proof-of-concept tissue experiments presented here the required magnetic field gradient of 20 T m−1 was realized by a permanent magnet array. MNPs with an optimized multicore structure were selected for this application by evaluating their stability against agglomeration of MNPs with different coatings in water for injections, physiological sodium chloride solution and biological media such as artificial tear fluid. From these investigations, starch turned out to be the most promising coating material because of its stability in saline fluids due to its steric stabilization mechanism. To evaluate the passage of MNPs through the sclera and cornea of the eye tissues of domestic pigs (Sus scrofa domesticus), a three-dimensionally printed setup consisting of two chambers (reservoir and target chamber) separated by the eye tissue was developed. With the permanent magnet array emulating the magnetic field gradient of the superconducting setup, experiments on magnetically driven transport of the MNPs from the reservoir chamber into the target chamber via the tissue were performed. The resulting concentration of MNPs in the target chamber was determined by means of quantitative magnetic particle spectroscopy. It was found that none of the tested particles passed the cornea, but starch-coated particles could pass the sclera at a rate of about 5 ng mm−2 within 24 h. These results open the door for future magnetic drug targeting to the eye.

Quantitative Microdialysis: Experimental Protocol and Software for Small Molecule Protein Affinity Determination and for Exclusion of Compounds with Poor Physicochemical Properties

Quantitative microdialysis is a traditional biophysical affinity determination technique. In the development of the detailed experimental protocol presented, we used commercially available equipment, rapid equilibrium dialysis (RED) devices (ThermoFisher Scientific), which means that it is open to most laboratories. The target protein and test compound are incubated in a chamber partitioned to allow only small molecules to transition to a larger reservoir chamber, then reversed-phase high performance liquid chromatography (RP-HPLC) or liquid chromatography–mass spectrometry (LC–MS) is used to determine the abundance of compound in each chamber. A higher compound concentration measured in the chamber that contains the target protein indicates binding. As a novel, and differentiating contribution, we present a protocol for mathematical analysis of experimental data. We provide the equations and the software to yield dissociation constants for the test compound-target protein complex up to 0.5 mM KD, and we quantitatively discuss the limitations of affinities in relation to measured compound concentrations.

Biosynthetic origin of benzoquinones in the explosive discharge of the bombardier beetle Brachinus elongatulus.

Bombardier beetles are well-known for their remarkable defensive mechanism. Their defensive apparatus consists of two compartments known as the reservoir and the reaction chamber. When challenged, muscles surrounding the reservoir contract sending chemical precursors into the reaction chamber where they mix with enzymes resulting in an explosive discharge of a hot noxious chemical spray containing two major quinones: 1,4-benzoquinone and 2-methyl-1,4-benzoquinone (toluquinone). Previously, it has been speculated that the biosynthesis of all benzoquinones originates from one core precursor, 1,4-hydroquinone. Careful ligation of the base of the reservoir chamber enabled us to prevent the explosive reaction and sample untransformed reservoir fluid, which showed that it accumulates significant quantities of 1,4-hydroquinone and 2-methyl-1,4-hydroquinone. We investigated the biosynthetic mechanisms leading to quinone formation by injecting or feeding Brachinus elongatulus beetles with stable-isotope-labeled precursors. Chemical analysis of defensive secretion samples obtained from 1,4-hydroquinone-d6-administered beetles demonstrated that it underwent conversion specifically to 1,4-benzoquinone. Analogously, results from m-cresol-d8 injected or fed beetles confirmed that m-cresol is metabolized to 2-methyl-1,4-hydroquinone, which is then oxidized to 2-methyl-1,4-benzoquinone in the hot spray. Our results refute the previous claim that 1,4-hydroquinone is the precursor of all substituted benzoquinones in bombardier beetles and reveal that they are biosynthetic products of two independent pathways. Most likely, the aforementioned biosynthetic channel of hydroxylation of appropriate phenolic precursors and subsequent oxidation is not restricted to bombardier beetles; it could well be a general pathway that leads to the formation of all congeners of benzoquinones, one of the most widely distributed groups of defensive compounds in arthropods. Graphical abstract.

Mathematical Modelling and Computational Simulation of the Hydraulic Damper during the Orifice-Working Stage for Railway Vehicles

The objective of this paper is to establish an accurate nonlinear mathematical model of the hydraulic damper during the orifice-working stage. A new mathematical model including the submodels of the orifices, hydraulic fluids, pressure chambers, and reservoir chambers is established based on theories of the fluid mechanics, hydropneumatics, and mechanics. Subsequently, a force element based on the established model of the hydraulic damper which contains 56 inputs, 6 force states, and 47 outputs is developed with the FORTRAN language in the secondary development environment of the multibody dynamics software SIMPACK. Using the force element, the damping characteristics of the modified yaw damper with different diameters of the base orifice are calculated under different amplitudes and frequencies of the sine excitation, and then the simulation results are compared with the experimental results which are obtained under the same conditions. Results show that during the orifice-working stage, the new established mathematical model can accurately reproduce the nonlinear static and dynamic characteristics of hydraulic dampers such as the force-displacement characteristic, force-velocity characteristic, fluid shortage, hysteresis effect, and pressure limited effect. Furthermore, it also shows that the nonlinear characteristics of the orifice, air release, cavitation, leakage for high frequencies, and dynamic characteristics of fluid (i.e., the density, bulk modulus, and air/gas content) should be taken seriously during the modelling of the hydraulic damper at the orifice-working stage. The mathematical model proposed in this paper is more applicable to the railway vehicle system dynamics and individual system description of the hydraulic damper.

Hybrid Upflow-Anaerobic Filter (HU-AF) Integrated technology for bio-methane generation from vinasse with shorter hydraulic retention time

Research about Hybrid Upflow-Anaerobic Filter (HU-AF) integrated technology for bioenergy generation from vinasse was conducted. Modification of influent flow system, expansion of filter contact area and addition of gas accumulator for biogas collection were used to enhance the degree of vinasse biodegradation biogas generation, and yet to shorten the hydraulic retention time (HRT). Hybrid Upflow-Anaerobic Filter (HU-AF) integrated technology was a double dome reactor with sequential connection, with up-flow inlet distribution inside the reactor. Total volume of HU-AF was 60 m3. A mixing and a feeding chamber, with volume 3 m3, each were installed before HU-AF reactor. A reservoir chamber with volume of 6 m3 was added after HU-AF reactor. OLR was 2.04 kg COD/day. A methanogenic seed sludge derived from anaerobic lagoon. The experiment was carried out initially by seeding, acclimatization and adaptation of microorganisms inside the reactor. A feeding ratio of vinasse: water = 1:4, and initial pH of 6 were adjusted. Result showed that Full-scale HU-AF integrated technology was able to degrade COD with maximum degradation of COD 55.45% at pH 7.1, and shorten the HRT into 32 days. Biogas production was consisted of 57.21 % methane, 13.98% CO2 and various gases 28.1% (H2S, VOC, CO and H2O). This experiment showed that HRT was shorter than conventional reactor.

A hydraulic-driven piezoelectric pump with separable channel for drug delivery

In order to further optimize the overall performance of separable piezoelectric drug delivery pump, a hydraulic-driven piezoelectric pump with separable channel for drug delivery (HPPSCDD) is proposed, which can realize the reuse of piezoelectric actuator. Initially, the influencing factors of the HPPSCDD output performance were analyzed theoretically in the regard of the maximum output flow and optimal working frequency. Then, HPPSCDD prototypes were designed and manufactured. Finally, based on key design parameters combination, the test and analysis of output flow properties were carried out. Experimental results indicated that, the optimum working frequency increases as increase of diaphragm thickness; when diaphragm thickness is fixed, the maximum output flow declines as increase of reservoir chamber height. The optimal performance can reach 8.70 ml/min at 20 Hz for the combination of 0.1 mm diaphragm thickness and 4.7 mm reservoir chamber height. HPPSCDD proposed in this paper has the advantages of simple structure, stable performance and convenient installation, which provides an important reference for the practical application of piezoelectric pump in the field of drug delivery.

Fabrication and preliminary testing of hydroxylammonium nitrate (HAN)-based ceramic microthruster for potential application of nanosatellites in constellation formation flying

Constellation formation flying of nanosatellites (< 10 kg) is becoming a trend for future space exploration missions. Liquid chemical micropropulsion that can provide high thrusting force for high ΔV orbital transfer is a crucial hardware component for successful constellation re-positioning. However, liquid chemical micropropulsion system dedicated for these nanosatellites still not currently available in the market. In this study, a microthruster was fabricated using alumina toughened zirconia (ATZ) as structural material and yttria-stabilised zirconia-graphene (YSZ-Gr) as electrode material. The device has a dimension of 1.7 cm (length) × 1.3 cm (width) × 0.5 cm (thickness) and weighing only 6.18 grams, comprising of five major components such as propellant reservoir, injector, electrodes, micronozzle and reaction chamber. Material characterization shows that both materials have negligible weight loss and small reduction in material hardness and fracture toughness after 20 thermal-vacuum cycles. Moreover, results from dynamic mechanical analysis (DMA) ascertain that addition of graphene significantly enhanced the damping behaviour of the zirconia composite. Electrolytic decomposition of hydroxylammonium nitrate (HAN) solution in the reaction chamber has been demonstrated with maximum thrust of 180.53 mN at a propellant flow rate of 60 µl/s. The preliminary results suggest that the HAN-based ceramic microthruster could potentially be used as primary propulsion for nanosatellites in constellation formation flying.