Open Air Test Research Articles

Experimental study on small-scale hydrogen liquefaction of 0.5 L/h

A small-scale hydrogen liquefaction device based on two-stage G-M refrigerator was designed and manufactured. Many practical operation processes on the liquefaction device were conducted in the open-air test base. The experimental results shown that 1) The direct liquefaction scheme of micro-positive pressure with normal temperature hydrogen realized by two-stage pressure reducing valve was feasible and effective; 2) Design of four-stage heat exchanger for G-M refrigerator cold head was reasonable and reliable; 3) The liquefaction rate in pure hydrogen was 0.47 L/h, and liquefaction pressure can maintain the range of about 120 kPa∼160 kPa; 4) After venting hydrogen-helium mixture, the liquefaction rate of hydrogen was 0.439 L/h again. In other words, the previously filled helium in the liquid hydrogen Dewar could be discharged through multiple venting method. The residue helium had little effect on the hydrogen liquefaction rate; 5) The scheme of simultaneous liquefaction and transmission was proved to be feasible; 6) Operation process experience and safety precautions on the hydrogen liquefaction were summarized. The testing results provided a technical support for design and operation of small-scale hydrogen liquefactions.

Electroacupuncture Attenuates Depressive Disorder and Gastrointestinal Dysfunction in Myocardial Hypertrophy via Upregulation of 5-HT on Rats

Although acupuncture therapy, as a preventive and therapeutic technique, is low or no risk for some cardiovascular diseases, its role in safeguarding myocardial hypertrophy (MH) has not been clarified. Therefore, this study focused on examining whether electroacupuncture (EA) can alleviate MH by up-regulating tryptophan 5-serotonin (5-HT) metabolism, depressive disorder, and gastrointestinal dysfunction in MH rat models. We evaluated the effect of EA on myocardial ischemia in the ISO-induced myocardial hypertrophy (MH) rat model. Forty SpragueDawley (SD) rats aged 3 months were randomly divided into normal group, model group, EA group, and sham EA group with 10 rats in each group. Heart weight/body weight ratio (HW/BW) and left ventricular weight/body weight ratio (LVW/BW) were used to evaluate the regression of MH. Cardiac pathology was evaluated by ultrastructural observation and hematoxylin and eosin (H&E) staining. Sucrose preference test (SPT), forced swimming test (FSW), and open-air test (OFT) were used to study depressive Although acupuncture therapy, as a preventive and therapeutic technique, is low or no risk for some cardiovascular diseases, its role in safeguarding myocardial hypertrophy (MH) has not been clarified. Therefore, this study focused on examining whether electroacupuncture (EA) can alleviate MH by up-regulating tryptophan 5-serotonin (5-HT) metabolism, depressive disorder, and gastrointestinal dysfunction in MH rat models. We evaluated the effect of EA on myocardial ischemia in the ISO-induced myocardial hypertrophy (MH) rat model. Forty Sprague – Dawley (SD) rats aged 3 months were randomly divided into normal group, model group, EA group, and sham EA group with 10 rats in each group. Heart weight/body weight ratio (HW/BW) and left ventricular weight/body weight ratio (LVW/BW) were used to evaluate the regression of MH. Cardiac pathology was evaluated by ultrastructural observation and hematoxylin and eosin (H&E) staining. Sucrose preference test (SPT), forced swimming test (FSW), and open-air test (OFT) were used to study depressive behavior. The gastric retention and intestinal transport were evaluated by carbon powder labeling and the expression of 5-HT in the cerebral cortex and ileum was detected by immunohistochemistry. Depression-like symptoms in rats can be relieved by EA therapy. For instance, the consumption rate of sucrose solution was higher, the total distance and central distance in the open field test were increased, and EA treatment could reduce the immobility time of these rats. Swimming, struggling and immobility latencies were also increased in the forced swimming test. After EA treatment, the expression of 5-HT in the cerebral cortex and ileum increased. Finally, we found that EA ameliorated ischemia, depression, and gastrointestinal dysfunction in ISO-induced MH rats, which may be related to 5-HT metabolism.

Effect of Shock Wave on Constant Load Behaviour of Pb-Free/Cnt Solder Joint

The constant load behaviour of SAC305 solder joint with addition of carbon nanotube (CNT), exposed to shock wave condition was investigated. Formulated SAC305-CNT solder pastes with 0.04 wt. % CNT were manually printed to the printed circuit board (PCB) with copper surface finish to form solder joint. The solder joint was exposed to the shock wave condition via open field blast air test using Trinitrotoluene (TNT) explosive. Nanoindentation approach was used to determine the constant load behavior of the SAC305-CNT solder joint under shock wave condition. The results showed that addition of CNT reduced the indentation depth of SAC305 solder joint at 10 mN peak load for blast test sample and control sample. Indentation depth displacement of SAC305-CNT solder joint for blast test sample and control sample were reduced about ~ 42 and ~56%, respectively, if compared to the SAC305 solder joint for blast test sample and control sample. SAC305-CNT solder joint was experienced minimal changes of stress exponent when exposed to the shock wave. The existence of CNT in the solder joint slows down the depth displacement due to constant load.

Angular needle tracker and stabilizer for image-guided interventions

Introduction Minimally invasive image-guided interventions have changed the face of procedural medicine. For these procedures, safety and efficacy depend on precise needle placement. Needle targeting devices help improve the accuracy of needle placement, but their use has not seen broad penetration. Some of these devices are costly and require major modifications to the clinical workflow. In this article, we developed a low-cost, disposable, and easy-to-use angulation tracking device, which was based on a redesigned commercial passive needle holder. Material and methods The new design provided real-time angulation information for needle tracking. In this design, two potentiometers were used as angulation sensors, and they were connected to two axes of the passive needle holder’s arch structure through a 3 D-printed bridge structure. A control unit included an Arduino Pro Mini, a Bluetooth module, and two rechargeable batteries. The angulation was calculated and communicated in real time to a novel developed smartphone app, where real-time angulation information was displayed for guiding the operator to position the needle to the planned angles. Results The open-air test results showed that the average errors are 1.03° and 1.08° for left–right angulation and head–foot angulation, respectively. The animal cadaver tests revealed that the novel system had an average angular error of 3.2° and a radial distance error of 3.1 mm. Conclusions The accuracy was comparable with some commercially available solutions. The novel and low-cost needle tracking device may find a role as part of a real-time precision approach to both planning and implementation of image-guided therapies.

The effectiveness of drones in measuring particulate matter

The use of low-cost air pollution sensors mounted on drones is an exciting new approach to conduct affordable and highly resolved air quality measurements. However, the air flow around a drone consists of complex, unsteady turbulent structures which interact directly with ambient particulate matter and gases. These interactions influence the transport of fine particulate matter (e.g. PM2.5) and, subsequently, its measurement using on-board PM sensors. In this work, we aim to quantify this effect by conducting wind tunnel and open-air experiments using a quadrotor drone and an array of low-cost sensors and research grade instruments. Sensors and instruments were placed around the drone to assess the effect of mixing, dilution, and particle segregation in the wake generated by the drone. Our results indicate little impact on the shape of the particle size distribution but significant differences (p<0.05) in PM2.5 concentration ranging from -70% to greater than 400% when comparing measurements before and after the drone is turned on. These effects varied greatly with sensor location and across experiments. In the wind tunnel, the sensor least affected was located far upstream from the drone with concentration differences less than 7%. The sensor far downstream from the drone as well as one of the sensors to the side of the drone also showed relatively small concentration differences (<50%) compared to the other sensors. In the open-air tests, the sensor directly under the drone and one of the sensors to the side drone showed the smallest changes after the drone was turned on with concentration differences less than 20%. This study highlights many important factors to consider when working with low-cost sensors mounted on drones. It also lays the groundwork for more in-depth studies into how to effectively take air-quality measurements using drones.

The Feasibility of Using a Smartphone Magnetometer for Assisting Needle Placement.

Minimally invasive surgical procedures often require needle insertion. For these procedures, efficacy greatly depends on precise needle placement. Many methods, such as optical tracking and electromagnetic tracking, have been applied to assist needle placement by tracking the real-time position information of the needle. Compared with the optical tracking method, electromagnetic tracking is more suitable for minimally invasive surgery since it has no requirement of line-of-sight. However, the devices needed for electromagnetic tracking are usually expensive, which will increase the cost of surgery. In this study, we presented a low-cost smartphone-based permanent magnet tracking method compatible with CT imaging and designed a 3D printed operation platform to assist with needle placement prior to needle insertion during minimally invasive surgery. The needle positioning accuracy of this method was tested in an open air test and a prostate phantom test in a CT environment. For these two tests, the average radial errors were 0.47 and 2.25 mm, respectively, and the standard deviations were 0.29 and 1.63, respectively. The materials and fabrication required for the presented method are inexpensive. Thus, many image-guided therapies may benefit from the presented method as a low-cost option for needle positioning prior to needle insertion.

Experimental Study on Air Decomposition By-Product Under Creepage Discharge Fault and Their Impact on Insulating Materials

Creepage discharge faults in air on solid insulating material play a vital role in degradation and ageing of material which ultimately leads to breakdown of power system equipment. And electric discharge decompose air in to its byproducts such as Ozone and NOx gases. By analyzing air decomposition gases is a potential method for fault diagnostic in air. In this paper, experimental research has been conducted to study the effect of creepage discharge on rate of generation of air decomposition by-products using different insulating materials such as RTV, epoxy and fiberglass laminated sheet. Moreover XRF analysis has been done to analyze creepage discharge effect on these insulating materials. All experiments have been done in an open air test cell under constant temperature and pressure conditions. While analysis has been made for low and high humidity conditions. The results show that the overall concentration of air decomposition byproducts under creepage discharge in low humidity is 4% higher than concentration measured in high humidity. Based on this study a mathematical relationship is also proposed for the rate of generation of air decomposition by-products under creepage discharge fault. This study leads to indirect way for diagnostic of creepage discharge propagation in air.

Rotational Raman-based temperature measurements in a high-velocity, turbulent jet

Spontaneous rotational Raman scattering spectroscopy is used to acquire measurements of the mean and root mean square (rms) temperature fluctuations in turbulent, high-velocity heated jets. Raman spectra in air were obtained across a matrix of radial and axial locations downstream from a 50 mm diameter nozzle operating from subsonic to supersonic conditions over a wide range of temperatures and Mach numbers, in accordance with the Tanna matrix frequently used in jet noise studies. These data were acquired in the hostile, high noise (115 dB) environment of a large scale open air test facility at NASA Glenn Research Center (GRC). Temperature estimates were determined by performing non-linear least squares fitting of the single shot spectra to the theoretical rotational Stokes spectra of N2 and O2. The laser employed in this study was a high energy, long-pulsed, frequency doubled Nd:YAG laser. One thousand single-shot spectra were acquired at each spatial coordinate. Mean temperature and rms temperature variations were calculated at each measurement location. Excellent agreement between the averaged and single-shot temperatures was observed with an accuracy better than 2.5% for temperature, and rms variations in temperature between ±2.2% at 296 K and ±4.5% at 850 K. The mean and normalized rms temperatures measured here were then compared to NASA’s Consensus data set of PIV velocity and turbulence measurements in similar jet flows. The results of this and planned follow-on studies will support NASA GRC’s development of physics-based jet noise prediction, turbulence modeling and aeroacoustic source modeling codes.

Criteria Defining Rain Protecting External Rendering Systems

In the 1960s and 70s extensive experimental investigations were carried out at the open air test site of the Fraunhofer-Institute of Building Physics concerning the driving rain protection of Autoclaved Aerated Concrete (AAC) walls coated with innovative synthetic resin renders. Since some of the exposed test walls did not perform as well as others, a correlation between the water absorption and the vapour diffusion properties of the façade coatings was established. This correlation was subsequently introduced into the German Standard for exterior rendering systems with a slight modification to account for the special characteristics of mineral renders.When models to simulate transient heat and moisture transport processes in the building envelope were successfully applied in the middle of the 90s, parametric studies confirmed that the empirical correlation, established 30 years ago, is appropriate to define the rain protection characteristics of façade systems. However, the magnitude of the parameters depends on the climate conditions and the wall assembly. While the existing specifications are suitable for moderately insulating masonry, walls made out of well-insulated blocks may get too wet. Similarly, masonry structures with interior insulation may accumulate too much moisture behind the insulation layer unless the existing limit for the water absorption coefficient is reduced by 60% for high wind driven rain zones. Recent calculation results show that the local driving rain load and intermittent drying conditions as well as the characteristics of the substrate are the principle factors for selecting limit criteria for rain protecting rendering systems.

Corrosion Behavior of Extruded near Eutectic Al–Si–Mg and 6063 Alloys

In this work, a comparison study on corrosion behavior of extruded near eutectic Al–12.3%Si–0.26%Mg and 6063 alloys has been carried out by mass loss test in 4% H 2 SO 4 aqueous solution in the open air and potentiodynamic polarization test in 3.5 wt.% NaCl aqueous solution. Results indicate that the corrosion resistance of the near eutectic Al–Si–Mg alloy is less than that of 6063 alloy. Macro/microscopy and scanning electron microscopy results clearly show the difference of the corrosion progress of these two alloys in 4% H 2 SO 4 aqueous solution. The corrosion type of 6063 alloy is pitting corrosion. The Mg 2 Si and AlFeSi particles and surface defects act as nucleation sites for pitting, and the amount and distribution of them have a significant effect on the pitting behavior. For the near eutectic alloy, there are two types of corrosion cells. One is between the extruded primary α-Al and the eutectic, the other is between the eutectic Al and eutectic Si particles. Combination of these two types of corrosion cells leads to a lower corrosion resistance, a higher mass loss of the near eutectic alloy compared with 6063 alloy, and the formation of the paralleling corroded grooves.

Brand new fire test facilities at ‘BAM Test Site Technical Safety’

AbstractFire testing is an essential part of the hypothetical, cumulative mechanical and thermal accident test conditions that shall guarantee package safety in severe accidents. Not only for radioactive material transport packages but also for other containments of dangerous goods, international standards require specific thermal load specifications. Following the guideline ‘Safety in technology and chemistry’ BAM, as a scientific and technical German federal government institute, operates a 12 km2 large open air test facility for experimental investigations of dangerous goods and their containments. On an area beside the well-known 200-ton drop test facility, BAM has put into operation a new fire test facility. This facility provides two fire test stands that utilise liquid propane as fuel from a central, earth-covered 60 m3 LPG storage tank. From that storage the propane is pumped via pipelines to the test stands where the gas is released from nozzles, and ignited by ignition burners. The fire exposure...

Development and performance evaluation of a high velocity burner for furnace operations

Burners are very important in the metal processing industries where they are used for a variety of purposes. A high velocity burner is developed and tested. The main components of the burner include the burner nozzle, mixing tube, down-stream section and the throat. A cross-connected Regulator is also incorporated for air fuel ratio control. An open-air test was carried out on the burner and flame temperature values were taken along the axial flame axis for different gas pressures. From the test carried out, the highest temperatures recorded were 488.1, 688.8 960.3 and 1275 C for gas pressures maintained at 30, 60, 90 and 100% corresponding to 0.53, 1.02, 1.53 and 1.7 bar respectively. The results show that the burner can be used for high temperature Furnace applications.

Analysis of Properties of Reflectance Reference Targets for Permanent Radiometric Test Sites of High Resolution Airborne Imaging Systems

Reliable and optimal exploitation of rapidly developing airborne imaging methods requires geometric and radiometric quality assurance of production systems in operational conditions. Permanent test sites are the most promising approach for cost-efficient performance assessment. Optimal construction of permanent radiometric test sites for high resolution airborne imaging systems is an unresolved issue. The objective of this study was to assess the performance of commercially available gravels and painted and unpainted concrete targets for permanent, open-air radiometric test sites under sub-optimal climate conditions in Southern Finland. The reflectance spectrum and reflectance anisotropy and their stability were characterized during the summer of 2009. The management of reflectance anisotropy and stability were shown to be the key issues for better than 5% reflectance accuracy.

Photocatalytic inactivation and removal of algae with TiO2-coated materials

The capabilities of TiO2-coated materials for the inactivation and removal of algae were investigated. As supports for TiO2, non-woven fabric and Ni foam were chosen. To evaluate the ability of noble metal cocatalyst additions to facilitate the photocatalytic algal inhibition of TiO2-coated materials, Pd nanoparticles were deposited on non-woven fabric-supported TiO2 by photoelectrochemical deposition. The fabric-supported Pd/TiO2 showed higher inhibition activity for algal growth compared to the fabric-supported TiO2 without Pd. In addition, Ni foam-supported TiO2 also showed high inhibition activity, both in laboratory-scale tests and open-air tests. Therefore, TiO2-coated materials with suitable coating methods such as the use of cocatalysts or large surface area can substantially inhibit algal growth. The ability of the TiO2-coated materials to inhibit algae correlated well with their activity for the photocatalytic decolorization of methylene blue, suggesting a nonspecific mechanism in the breakdown of cellular structures.

Transient Calculation of the Boundary Layer Flow over Spills

AbstractIn this work, results of numerical simulations and experimental investigations of the mass flow from evaporating liquid pools are presented. Numerical simulations are based on the boundary layer equations combined with an algebraic turbulence model. The experiments were carried out on open air test sites within flat and very rough topographies, at different temperatures with ethanol and cyclohexane as the evaporating liquids. An experimental investigation of the influence of the topography on the evaporation of a liquid pool is conducted. The results of the simulation are validated against experimental data from the open air experiments. Furthermore, a comparison of the simulation results with empirical prediction models has been made.

Experiences with the Weather Parameter Method for the use in overhead line monitoring systems

Overhead lines are essential components of high voltage power systems worldwide. The performance of this network element is important for a save and reliable transmission of electrical energy. The load capability of a line is related basically to the line design itself and takes centre stage of the economic operation whereas the sag behaviour and the technical condition of the conductor and their components are more related to the line and network safety. Based on this situation overhead line monitoring systems are actually under discussion in many committees worldwide. This auxiliary equipment for overhead power lines helps to evaluate the actual transfer capability and/or to increase the system reliability. Therefore, a number of systems using different measuring methods and monitoring techniques are available on the market. More or less all methods are based on physical data and process information to achieve a suitable output to control the line stress. One of these methods is called the Weather Parameter Method, which uses local metrological weather data and system load information to estimate the conductor temperature. In a research project running over years an overhead line monitoring system was set up in cooperation with the Austrian transmission utility APG. After these years of experience a number of information and data based on the principle of the Weather Parameter Method is available and gives the scientific basement for this contribution. Three observation stations are collecting data all over the year; two stations are at a 220 kV overhead line and one station at the open air test field of the IHS in Graz in use. This contribution focuses on the coherences of the different parameters collected for the evaluation of the conductor temperature and it is not the main goal to discuss the improved performance by using a thermal management system, as mentioned in many other papers. By the knowledge of the punch-through of significant parameters in combination with the appearance probability a more accurate scheduling of the utilisation of the line under observation will be possible. A well prepared processing of many significant parameters for an overhead line monitoring system and a scientific approach based on some years of practical experience is presented in this contribution.

Effect of injection-nozzle operating parameters on the interaction between a gas–liquid jet and a gas–solid fluidized bed

The objective of the present study was to provide insight into the effect of operating conditions on the performance of gas-assisted nozzles injecting liquid into gas–solid fluidized beds. Acquisition of such knowledge is relevant to many industrial applications where liquid injections into fluidized beds of solid particles are performed via spray nozzles. In the fluid coking process, for example, product yields and reactor operability strongly benefit from a rapid and uniform distribution of the liquid feed on fluidized solid particles, which, in turn, is greatly affected by the performance of the liquid-injection system used. A novel experimental technique was employed to investigate the effect of varying the air-to-liquid ratio (ALR), the liquid mass flow rate, and the nozzle size on the contact efficiency of injected liquid on fluidized bed particles. Increasing the ALR or the liquid flow rate increased the nozzle spraying efficiency. On the contrary, increasing the nozzle size while keeping the gas and the liquid flow rates constant, and hence decreasing the pressure at the nozzle tip, lowered the liquid–solid contact efficiency. The effect of increasing the ALR on the liquid–solid contact resulting from nozzle-injections into the fluid bed, was correlated to both the nozzle atomization performance, as determined by open-air tests using a laser-photocell equipment, and the solids entrainment into the gas–liquid jet, as predicted by a model.

Real-Time Fluorogenic Reverse Transcription-PCR Assays for Detection of Bacteriophage MS2

Bacteriophage MS2 is used in place of pathogenic viruses in a wide variety of studies that range from testing of compounds for disinfecting surfaces to studying environmental transport and fate of pathogenic viruses in groundwater. MS2 is also used as a pathogen simulant in the research, development, and testing (including open air tests) of methods, systems, and devices for the detection of pathogens in both the battlefield and homeland defense settings. PCR is often used as either an integral part of such detection systems or as a reference method to assess the sensitivity and specificity of microbial detection. To facilitate the detection of MS2 by PCR, we describe here a set of real-time fluorogenic reverse transcription-PCR assays. The sensitivity of the assays (performed with primer pairs and corresponding dye-labeled probes) ranged from 0.4 to 40 fg of MS2 genomic RNA (200 to 20,000 genome equivalents). We also demonstrate the usefulness of the primer pairs in assays without dye-labeled probe that included the DNA-binding dye SYBR green. None of the assays gave false-positive results when tested against 400 pg of several non-MS2 nucleic acid targets.

Strengthening the BTWC: The role of the Biological and Toxin Weapons Convention in combating natural and deliberate disease outbreaks

Strengthening the BTWC: The role of the Biological and Toxin Weapons Convention in combating natural and deliberate disease outbreaks

The history of biological warfare: Human experimentation, modern nightmares and lone madmen in the twentieth century

The history of biological warfare: Human experimentation, modern nightmares and lone madmen in the twentieth century