Commercial Tube Research Articles

Light-Emitting Diode-Based Pulsed Illumination Source for Continuous, Cycle-Resolved Spray Measurements

This paper presents a modular, high-powered light emitting diode (LED)-based illumination source to be used for spray measurements of the liquid phase via Mie scattering. The recent availability of consumer-grade LED arrays with average rated radiant powers of more than 100 W have enabled lower-cost designs than were possible with the previous laser illuminants. Flash tubes suffer from a non-constant rate of emission intensity and a fixed discharge time,which can be a restricting factor, especially with multiple injections. The narrow spectral distributionof LEDs,with a full width at half maximum of 17nm,aids in distinguishing the measurement signal from unwanted background noise.Using frame- synchronous LED pulse generation at repetition rates of 100 kHz,it is possible to record both arbitrarily spaced multiple injections as well as consecutive working cycles, for example ininternal combustion engines. Pulse durations are currently variable in the range 1-78 μs. Luminous flux is boosted by driving the light source at a significantly higher current and voltage as compared to the continuously rated specifications, which results in a high temporal resolution,as exposure times as low as oneμs provide ample recorded intensities. Benchmarks based on a commercial xenon flash tube and laser diode demonstrate the design’s versatility along with first applications in an optically accessibly research engine.

Activated nitrogen-doped ordered porous carbon as advanced anode for high-performance microbial fuel cells

Microbial fuel cells (MFCs) emerge as an active research topic in environmental engineering as they can effectively recover energy by degrading organic pollutants. However, the low power output impedes their further development. In this study, natural cassava straws are used as a carbon source to prepare activated nitrogen-doped porous carbon via a facile electrochemical activation method. Scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transformer infrared (FT-IR) spectra, and nitrogen adsorption-desorption experiments are conducted to characterize the as-prepared carbon materials. The results indicate that the electrochemical treatment endows the carbon substrate with a large pore volume and some nitrogen and oxygen dopants, which dramatically enhance its electrochemical performance. Consequently, the maximum power density of the MFC with the three-dimensional porous carbon anode prepared under an electrical current of 5 mA reaches 2204.5±29 W m−3, which is 1.90 and 2.76 times of the power densities of the MFCs with the unmodified anode (1155.6±41W m−3) and a commercial graphitic tube anode (808.24 W m−3), respectively. This study provides a meaningful reference for the development of biomass-based, highly efficient, three-dimensional carbon anodes.

The effects of inclination on a two stage pulse tube cryocooler for use with a ground based observatory

Ground-based observatories across a wide range of wavelengths implement cryogenic cooling techniques to increase the sensitivity of instruments and enable low temperature detector technologies. Commercial pulse tube cryocoolers (PTCs) are frequently used to provide 40K and 4K stages as thermal shells in scientific instruments. However, PTC operation is dependent on gravity, giving rise to changes in cooling capacity over the operational tilt range of pointed telescopes. We present a study of the performance of a two stage PTC with a cooling capacity of 1.8W at 4.2K and 50W at 45K (Cryomech PT420-RM) from 0-55° away from vertical to probe capacity as a function of angle over a set of realistic thermal loading conditions. Our study provides a method to extract temperature estimates given predicted thermal loading conditions across the angular range sampled. We then discuss the design implications for current and future tilted cryogenic systems.

Cost-effective technique to fabricate a tubular through-hole anodic aluminum oxide membrane using one-step anodization

In order to reduce the time required to prepare a tubular through-hole anodic aluminum oxide (AAO) membrane, this study improved the manufacturing processes using one-step anodization. AAO membranes were first prepared by using 6063 commercial aluminum alloy tubes using an external anodizing method. The manufacturing processes for a tubular through-hole AAO membrane include: annealing, physically wet grinding, buff wheel polishing, ultrasonic cleaning, one-step anodizing, aluminum substrate removing, and barrier layer alumina (BLA) etching. The influence of chemical etching time on the nanostructure of AAO membranes was observed by a Field Emission Scanning Electron Microscope (FE-SEM). The results of the fabrication of a tubular through-hole AAO membrane showed that increasing the chemical etching time of the BLA etching process could result in an enhanced nanotube pore size and a reduced AAO membrane thickness, and excessive chemical etching time would collapse the nanotube structure. The tubular through-hole AAO membrane obtained was straight nanotubes with a thickness of 48 μm and an average bottom pore size of 109 nm.

Characteristic Analysis and Design Optimization of Bubble Artificial Muscles.

Soft robotics requires new actuators and artificial muscles that are lighter, less expensive, and more effective than current technologies. Recently developed bubble artificial muscles (BAMs) are lightweight, flexible, inexpensive, pneumatic actuators with the capability of being scalable, contracting at a low pressure, and generating sufficient tension and contraction for assisting human mobility. The BAMs are simply fabricated by using a commercial plastic tubing with retaining rings, forming a “bubble” shape and creating a series of contractile units to attain a desired stroke. They can deliver high contraction through optimization of actuator length and radius, or high tension by strengthening their materials to operate at high pressure. Here, we present a detailed analysis of BAMs, define a model for their actuation, and verify the model through a series of experiments with fabricated BAM actuators. In tests, a maximum contraction of 43.1% and a maximum stress of 0.894 MPa were achieved, corresponding to the BAM lifting a load 1000 times its own weight (5.39 g). The BAM model was built to predict experimental performance, for example, the relationship between tension and contraction at various applied pressures, and between contraction and pressure. Characteristic analysis and design optimization of the BAM are presented as an approach to design and manufacture the ideal “bubble” actuator at any required dimensions. A BAM orthosis is demonstrated as assisting a sit-to-stand transition on a leg mechanism, constructed to match the scale of a human's lower limb. Guidelines for further improvement of the BAM are also included.

Commercial blood cell separation systems versus tube centrifugation methods for the preparation of platelet-rich plasma: a preliminary cross-sectional study.

Clinical studies claim that platelet-rich plasma (PRP) accelerates tissue healing due to its high concentration of growth factors and that the combination with leukocytes improves the antimicrobial effect of the concentrate. Most of these studies obtained PRP using different separation systems, and few analyzed the content of the PRP used for treatment. This study characterized the composition of PRP and white blood cells (WBC) from a single donor produced by three commercially available PRP separation systems and two anticoagulated general analytical tubes. Five patients donated 50 mL of blood, which was processed to produce PRP and WBC using three PRP concentration systems (i.e., Easy PRP Kit, GloPRP, and Wego) and two tubes for general analysis anticoagulated with ethylenediaminetetraacetic acid (EDTA) and citrate. Platelets and WBC in combination with their concentrates were analyzed by automated systems in a clinical laboratory. There were no significant differences in the average concentrations of PRP platelets and WBC between GloPRP and the tubes for general analysis with EDTA and citrate; however, the Easy PRP Kit gave results much superior to the rest of the methods, especially comparing it with the Wego Kit, whose concentrates were especially low, even nonexistent for WBC. The Easy PRP Kit concentrates WBC-rich PRP, resulting in increased WBC concentrations, compared with low WBC-low PRP of GloPRP and general tube methods for EDTA and citrate analysis and the even lower concentration of PRP from the Wego Kit, with the absence of leukocytes.

The protective effect of astaxanthin on cisplatin-induced ototoxicity.

Promising studies have been conducted with many substances to reduce the ototoxic effects of cisplatin, but there is no treatment that completely eliminates the ototoxic effect. To determine the effectiveness of astaxanthin (ASX) as a protective agent against cisplatin-induced ototoxicity. Thirty-six rats were randomly divided into 6 groups. Group 1 received no drug injections except for anesthetics; group 2 received intraperitoneal (IP) olive oil only for 8 days; group 3 received only IP ASX 75 mg/kg dissolved in olive oil for 8 days; group 4 received a single dose of only IP 16 mg/kg cisplatin on the 5th day; group 5 received 25 mg/kg ASX IP daily for 8 days and a single 16 mg/kg dose of cisplatin on the 5th day; group 6 received 75 mg/kg ASX IP daily for 8 days and a single 16 mg/kg dose of cisplatin on the 5th day. The animals were tested for distortion product otoacoustic emissions (DPOAE) before and 3 days after cisplatin treatment. The animals in all groups were sacrificed under anesthesia on the 10th day. Before sacrifice, inferior vena cava blood samples were drawn into commercial tubes for biochemical analysis and their cochlea were prepared for histological analysis. The ASX+cisplatin groups demonstrated significantly higher DPOAE thresholds when compared to the cisplatin-only group (p < 0.05). The ASX 25 mg/kg/day+cisplatin group showed a significant increase in total antioxidant capacity compared to the cisplatin-only group, whereas the ASX 75 mg/kg/day+cisplatin group had significantly lower total oxidative stress and oxidative stress index. Histologic results showed that the cortical organ was better preserved in the ASX+cisplatin groups compared to the cisplatin-only group, and the degeneration in the spiral ganglion and inner and outer hair cells was less visible in the ASX groups. Astaxanthin can protect hearing from cisplatin-induced ototoxicity, prevent cellular degeneration and significantly reduce oxidative stress.

Implosion tests of aluminium-alloy ring-stiffened cylinders subjected to external hydrostatic pressure

In this paper, the dynamic implosion responses of ring-stiffened cylindrical tubes under external hydrostatic pressure are reported. The ring-stiffened cylinder models were fabricated from commercial seamless aluminium-alloy 6061-T6 tubes. Six external stiffened models were constructed: three models with three stiffeners, and the other three with five stiffeners. To quantify the effects of stiffening on the structural behaviour, implosion tests were also performed on another three unstiffened tube models. In this study, a total of nine tube models were tested until their failure. Implosion was initiated by increasing the hydrostatic pressure in the chamber until the tubes collapsed, and the effects of different types of pressurising media were investigated: (i) water only and (ii) water and nitrogen gas combined. The implosion pressure pulse near the collapsing tube was recorded during the event. The models with five stiffeners increased the implosion pressure pulse by approximately 3.5 times compared with the unstiffened model.

Continuous synthesis of stable ferrocene nanoparticles using a self-aligned coaxial turbulent jet mixer

Ferrocene nanoparticles possess an outstanding characteristic as a drug delivery carrier, in being able to trigger on-demand release of drugs in a specific condition with reactive oxygen species (ROS). However, due to the limitation of the conventional bulk nanoprecipitation method, uniform and highly stable nanoparticles have still been difficult to develop. In this study, we developed device-mediated ferrocene nanoparticles (D-FNPs) with highly controlled uniform size and long-term stability through a flash nanoprecipitation method using a self-aligned coaxial turbulent jet mixer. The self-aligned coaxial turbulent jet mixer could be easily assembled using commercial tube fittings, which enabled the coaxial self-alignment of fluidic parts. In addition, by utilizing diaphragm pumps and pulsation dampers for the control of fluid flow, the coaxial turbulent jet mixer could be operated in a fully continuous manner. Thus, the D-FNPs could be prepared in a continuous manner with a high production rate of 633 mg/min. The D-FNPs were highly stable in aqueous media for 3 months. In addition, after lyophilization without any cryoprotectants, the D-FNPs exhibited stable dispersion in aqueous solution. Importantly, the D-FNPs maintained their original outstanding ROS-responsive characteristics, while showing no cytotoxicity.

High-speed continuous production of polymeric nanoparticles with improved stability using a self-aligned coaxial turbulent jet mixer

Continuous synthesis of polymeric nanoparticles (NPs) has been intensively studied due to its great potential to produce NPs with the physicochemical properties of reproducibility and controllability. Here, we developed a self-aligned coaxial turbulent jet mixer for high-speed continuous synthesis of polymeric NPs. The coaxial turbulent jet mixer can be constructed using commercial tube fittings and tubes. Since those fluidic components are self-aligned coaxially, leak-free jet mixers can be assembled without the use of tools or specialized skills in robust manner. Using the jet mixer with polystyrene (PS) solution, uniform polymeric NPs can be synthesized in a fully continuous manner, for which diaphragm pumps and pulsation dampers are used for continuous control of the flow. We also improved the dispersion stability of the PS NPs in aqueous solution against centrifugation by introducing polystyrene-poly(ethylene oxide) diblock copolymer (PS-b-PEO) as steric stabilizer. The NPs prepared using the coaxial turbulent jet mixer were smaller and more uniform in size compared to NPs synthesized by a bulk nanoprecipitation method.

Experimental Investigation of Illumination Performance of Hollow Light Pipe for Energy Consumption Reduction in Buildings

This work investigates the light illumination intensity, light transmission performance, light distribution on the floor, and daylight factor of vertical light hollow tubes at various incident elevation angles of a light source. The light tubes were made from commercial aluminum alloy sheets and commercial zinc alloy sheets to investigate internal illuminance for buildings and reducing the demand of electrical energy from artificial lighting. The vertical light tubes with a constant length of 0.5 m and diameters of 0.20, 0.25, and 0.30 m were designed in a testing room model, with dimensions of 1 m × 1 m × 1 m. A 20-W light-emitting diode (LED) lamp was used as the light source for the lighting simulations, which was placed away from the top of the light tube. The incident elevation angle of the light source was changed between 0° and 80° with 5° increments. It was found that the elevation angle of the incidence light had an influence on the light intensity distribution on both ends of light tube. The average illuminance performance of both material types increased with an increase of the incidence angle from 0° to 80° and an increase of the tube diameter from 0.20 m to 0.30 m. The commercial aluminum alloy tube promotes greater light transmission and daylight factor when compared with the commercial zinc alloy tube in each condition. This illuminance measurement demonstrates that the light tube could be included in the lighting systems of some deeper or windowless areas of buildings to decrease the demand of energy consumption in the lighting of buildings.

High Confidence Shotgun Lipidomics Using Structurally Selective Ion Mobility-Mass Spectrometry.

Ion mobility (IM) is a gas phase separation strategy that can either supplement or serve as a high-throughput alternative to liquid chromatography (LC) in shotgun lipidomics. Incorporating the IM dimension in untargeted lipidomics workflows can help resolve isomeric lipids, and the collision cross section (CCS) values obtained from the IM measurements can provide an additional molecular descriptor to increase lipid identification confidence. This chapter provides a broad overview of an untargeted ion mobility-mass spectrometry (IM-MS) workflow using a commercial drift tube ion mobility-quadrupole-time-of-flight mass spectrometer (IM-QTOF) for high confidence lipidomics.

Systematic approach to determine the transient cooling power and heat leak of a commercial pulse tube cryocooler

In a typical pulse tube cryocooler application, modeling the cool-down dynamics of a load attached to the cold tip require knowledge of the transient cooling power. Although this data may be calculated for in-house developed cryocoolers, the only data provided in commercial off-the-shelf cryocoolers is the steady state cooling power. In this paper, we show a systematic approach to derive transient cooling power data by performing heating and cooling experiments. The data obtained is verified with cooling data of an attached mass, which showed a good agreement. We also present a method to determine the parasitic heat load in a steady and transient operation of a commercial pulse tube cryocooler.

Design of an Instrument to Determine the Acoustic Characteristics of Non Wovens Made from Recycled Polyester, Jute and Flax

The influence of acoustic property of fabrics made from recycled polyethylene terephthalate (recycled PET), jute and flax fibres have been studied. Six different blended proportions (100 % Recycled PET, 100 % Jute, 100 % flax, 25 % jute: 25 % flax: 50 % recycled PET, 50 % jute: 25 % flax: 25 % recycled PET, 25 % jute: 50 % flax: 25 % recycled PET) of different grams per square meter 200, 400, 600 needle punched technique non woven fabrics have been produced and analyzed for their properties. The sound reduction of needle punched 50 % jute: 25 % flax: 25 % recycled PET non-woven has shown better performance among the six samples. The grams per square meter of the samples influence the sound reduction values of non woven fabric. Increase in gsm of the material also increases the sound reduction value. Among all the samples, the 50 % jute: 25 % flax: 25 % recycled PET non-woven sample produces good acoustic property in developed digital sound reduction tester and commercial sound impedance tube absorption co efficient value. Anova mathematical tool shows the there is a significant difference between input and output signal in the digital sound reduction tester. From the results, It is found that the sound reduction property of non woven fabrics increases and decreases with the types of fibre and grams per square meter of the samples. The jute non woven fabric can be used as good sound reduction material for various industrial applications.

Silicon Microfabricated Preconcentrator Design and Characterization

MEMS fabrication technology has been applied to build micro-GC systems for portable analysis and detection of volatile organic compounds for environmental monitoring, medical diagnostics and food safety and security (1). Pioneering work at Sandia National Laboratories developed - these miniature systems (2). Novel designs for pre-concentrators have been developed to provide efficient sample injection into these systems (3). We have integrated a 6m length micro-GC column with an ion trap mass spectrometer (4). To inject the sample into the column, our initial method was to use a syringe injection into a heated septum with Agilent 6890. However, for automated operation and method of sampling, pre-concentration of the volatile organic compounds is required, followed by rapid heating, for sample injection for analysis. A microfabricated pre-concentrator can fulfill this function by providing a high surface area in a compact platform with reduced thermal mass, compared to commercial desorption tubes. The design has an integrated platinum heater and was fabricated using standard photolithography, deep reactive ion etching and wafer bonding. To evaluate the performance, the pre-concentrator is mounted inside a commercial Agilent 6890 GC system. Liquid injections 0.02uL, using a syringe, with a 100:1 split, at a helium flow rate of 0.005 ml/min. The flow rate was increased during the desorption cycle, and the preconcentrator was heated by electrical current of providing approx. 5W to enable rapid heating to 180°C. This miniature pre-concentrator provides a small thermal mass design and was capable of fast desorption of several analytes with detection by FID.

Capacitively coupled discharge as a tunable impedance element for RF systems

A concept of plasma-based reconfigurable radio-frequency (RF) components is studied experimentally. The concept's main idea is to control the real and imaginary parts of impedance experienced through a weak high-frequency signal applied to the RF discharge electrodes by varying the plasma excitation frequency and/or power. To prove the concept, an experimental setup was built that enabled the application of both strong plasma excitation RF and weak RF/microwave signals to the same set of electrodes. Three different plasma cells were examined. The largest system had 5 cm diameter electrodes with 2 cm gap, and the experiments were conducted in argon at 1 Torr. The impedance characteristics of the plasmas as experienced by the probing signal in the range of 270–3000 MHz demonstrated wide variability and a complex non-monotonic behavior at high frequencies. Experiments with a smaller cell that had 1 cm diameter electrodes and 2 mm gap also showed the controllability of the real and imaginary parts of the impedance, including transition from capacitive to inductive behavior. Because of the smaller size comparable with the probing signal wavelength, the high-frequency behavior of this system can be described with a simple lumped-parameter equivalent circuit model. The smallest system studied in this work utilized a commercial sealed gas discharge tube as an RF plasma cell and also demonstrated wide impedance tunability and transition from capacitive to inductive behavior. These results could potentially be useful for plasma-based electronically reconfigurable RF electronics, particularly in applications involving high power where alternative solutions experience problems.

Intercostal chest drain fixation strength: comparison of techniques and sutures

ObjectiveThe accidental removal of an intercostal chest drain (ICD) is common and may result in serious complications. A number of fixation techniques and suture material are in use, and the...

Improved intact peptide and protein quantitation by LC-MS: Battling the deleterious effects of analyte adsorption.

Peptide and protein quantitation by liquid chromatography-mass spectrometry relies on the assumption of linear signal response with concentration. At low concentrations, analyte adsorption to pipette tips, sample vials and equipment can have significant deleterious effects on signal response. Meanwhile at high concentrations, linearity breaks down due to competitive ionization, signal suppression, and the formation of peptide or protein multimers. These effects result in calibration curves that are more sigmoidal than linear. Linearity at low protein levels for identification and quantitation is of paramount importance in the discovery and validation of biomarker molecules. Herein, we demonstrate the benefits of using commercial low-bind microcentrifuge tubes and LC vials on the response of a 27-mer peptide, Vn96, and the intact proteins apomyoglobin and carbonic anhydrase. Linear curves were acquired for Vn96 while apomyoglobin required the addition of intact carbonic anhydrase as an adsorption competitor to achieve linearity. A linear calibration curve for carbonic anhydrase was also acquired by using the polypeptide ubiquitin as an adsorption competitor and internal standard. Linear response was recorded for approximately two orders of magnitude for apomyoglobin and carbonic anhydrase and three orders of magnitude for Vn96 with detection limits ranging from 0.33 to 19 fmol/µL. Finally, we used low-bind vials for the online enzymatic digestion of apomyoglobin where a high concentration of apomyoglobin acted as an adsorption blocker for the low level trypsin enzyme. Fortunately, the liberated tryptic peptides showed no affinity for the walls of the low-bind vials. In this study, we take a comprehensive approach to combat analyte adsorption by showing the significance of utilizing low-bind vials and adsorption competitors to greatly improve upon signal sensitivity at low concentrations of target molecules. The use of these methodologies should improve the low-level detection of molecules by mass spectrometry.

Binder-free CuO nanoneedle arrays based tube-type sensor for H2S gas sensing

CuO nanoneedle arrays were directly prepared on the commercial ceramic tubes by magnetron sputtering and subsequent wet chemical etching and annealing. This brand-new fabrication of the tube-type gas sensor retains the high specific surface area of nanoneedle and avoids using binders that are generally used for coating gas-sensitive materials on the surface of the ceramic tube. The as-fabricated binder-free CuO nanoneedle arrays sensor exhibits a decent response of 76.50 % to 10 ppm H2S at a low temperature of 150 °C. The response decreases to 20.27 % as the relative humidity increases from 40 % to 80 %. Moreover, the sensor shows good selectivity, reproducibility, and long-term stability to a low concentration of 10 ppm H2S. This superior sensing performance can be attributed to the abundant surface reactive adsorption sites provided by CuO nanoneedle arrays and the sensitization effect of p-p nano-homojunctions that arose from the interlaced CuO nanoneedles.

Influence of periodic side-to-side and heaving motions on the performance of a Stirling pulse tube cryocooler

Cryocoolers can experience near-periodic heaving or side-to-side motion and acceleration in some applications, in particular on moving platforms. In this work, the effect of heaving and rolling (side-to-side movement) on a Stirling pulse tube cryocooler was experimentally studied. Periodic heaving and rolling motions with various amplitudes, and frequencies in the 0.2 to 0.8 Hz range were imposed on a test section using a motion platform. The test section represented a prototypical commercial pulse tube cryocooler (PTC). The PTC was tested at two different neutral positions, vertical with the cold end pointing down (ideal orientation) and vertical with the cold end pointing up (inverted). When the PTC was at vertical position with the cold end pointing down, heaving movement had no measurable influence on its performance. Furthermore, the rolling motion caused some fluctuation but less than 2% drop in the cooling power of the tested PTC. When the PTC was at inverted, upside-down position, it showed significantly more sensitivity to periodic motions. Heaving motion and rolling motion resulted in approximately 5% and 10% maximum drops in the cooling power, respectively. Rolling motion also caused larger fluctuation in cooling power, with amplitudes about 15% of the average cooling power. Increasing the frequency and the amplitude of the motions both had notable negative effects on the performance of the PTC.