Filter Assembly Research Articles

A Simple and Disposable Sampler for Inhalable Aerosol.

The state-of-the-art for personal sampling for inhalable aerosol hazards is constrained by issues of sampler cost and complexity; these issues have limited the adoption and use of some samplers by practicing hygienists. Thus, despite the known health effects of inhalable aerosol hazards, personal exposures are routinely assessed for only a small fraction of the at-risk workforce. To address the limitations of current technologies for inhalable aerosol sampling, a disposable inhalable aerosol sampler was developed and evaluated in the laboratory. The new sampler is designed to be less expensive and simpler to use than existing technologies. The sampler incorporates a lightweight internal capsule fused to the sampling filter. This capsule-filter assembly allows for the inclusion of particles deposited on the internal walls and inlet, thus minimizing the need to wash or wipe the interior sampling cassette when conducting gravimetric analyses. Sampling efficiency and wall losses were tested in a low-velocity wind tunnel with particles ranging from 9.5 to 89.5 μm. The results were compared to the proposed low-velocity inhalability criterion as well as published data on the IOM sampler. Filter weight stability and time-to-equilibrium were evaluated as these factors affect the practicality of a design. Preliminary testing of the new sampler showed good agreement with both the IOM and the proposed low-velocity inhalability curve. The capsule and filter assemblies reached equilibrium within 25h of manufacturing when conditioned at elevated temperatures. After reaching equilibrium, the capsule-filter assemblies were stable within 0.01mg.

Dimethyl sulfide adsorption from natural gas for solid oxide fuel cell applications

The use of solid oxide fuel cell (SOFC) systems in micro-CHP applications is of great interest because of high efficiency, low emissions and absence of noise. However, SOFCs are sensitive to degradation caused by organic sulfur compounds present in natural gas or added as odorants. Among them, dimethyl sulfide (DMS) is one of the sulfur species most resistant to purification treatments and, relative to DMS removal, a lack in literature is highlighted for the investigated application.Regarding adsorption technology, the present work deals with an organic sensitivity performance analysis of different commercial sorbents. Virgin and impregnated activated carbons and a natural zeolite were tested, varying gas hourly space velocity, reactor geometry and filter assembly. Because of differences in activity towards DMS exhibited by the investigated materials, to exploit their selectivity, also layered sorbents were realized and tested.Starting from resulting data, for the yearly operation of 1kWel SOFC-based micro-CHP system, an optimization of filter assembly (also considering multi-layered configurations) and operative conditions was performed, leading to a strong reduction in filter volume (up to five times) and cost (more than three times), with overall pressure drops compatible with pipeline gas distribution pressure.

Strength properties of composite clay balls containing additives from industry wastes as new filter media in water treatment

Pebble matrix filtration (PMF) is a water treatment technology that can remove suspended solids in highly turbid surface water during heavy storms. PMF typically uses sand and natural pebbles as filter media. Hand-made clay pebbles (balls) can be used as alternatives to natural pebbles in PMF treatment plants, where natural pebbles are not readily available. Since the high turbidity is a seasonal problem that occurs during heavy rains, the use of newly developed composite clay balls instead of pure clay balls have the advantage of removing other pollutants such as natural organic matter (NOM) during other times. Only the strength properties of composite clay balls are described here as the pollutant removal is beyond the scope of this paper. These new composite clay balls must be able to withstand dead and live loads under dry and saturated conditions in a filter assembly. Absence of a standard ball preparation process and expected strength properties of composite clay balls were the main reasons behind the present study. Five different raw materials from industry wastes: Red Mud (RM), Water Treatment Alum Sludge (S), Shredded Paper (SP), Saw Dust (SD), and Sugar Mulch (SM) were added to common clay brick mix (BM) in different proportions. In an effort to minimize costs, in this study clay balls were fired to <TEX>$1100^{\circ}C$</TEX> at a local brick factory together with their bricks. A comprehensive experimental program was performed to evaluate crushing strength of composite hand-made clay balls, using uniaxial compression test to establish the best material combination on the basis of strength properties for designing sustainable filter media for water treatment plants. Performance at both construction and operating stages were considered by analyzing both strength properties under fully dry conditions and strength degradation after saturation in a water bath. The BM-75% as the main component produced optimum combination in terms of workability and strength. With the material combination of BM-75% and additives-25%, the use of Red Mud and water treatment sludge as additives produced the highest and lowest strength of composite clay balls, with a failure load of 5.4 kN and 1.4 kN respectively. However, this lower value of 1.4 kN is much higher than the effective load on each clay ball of 0.04 kN in a typical filter assembly (safety factor of 35), therefore, can still be used as a suitable filter material for enhanced pollutant removal.

Ultra-thick porous films of graphene-encapsulated silicon nanoparticles as flexible anodes for lithium ion batteries

Silicon is a highly promising anode material of lithium ion batteries (LIBs) for its low insertion voltage and high reversible capacity. A flexible, honeycomb-like film of reduced graphene (RGO)/Si nanoparticles (NPs) composite with a thickness as thick as 25μm is synthesized by a facile vacuum filter assembly process. The Si NPs are enwrapped into the RGO sheets with an areal density of 0.65mgcm−2. The ultra-thick composite film is directly employed as an anode for LIBs without using any binder and conductive additive. The flexible RGO sheet coat enables the electrode to maintain the structural integrity and provide continuous conductive paths for Si NPs. The electrode exhibits a high capacity of 2370mAhg−1 over 50 cycles at a current of 210mAg−1 and a capacity higher than 1000mAhg−1 at a current density of 4200mAg−1 after 500 cycles. Especially, the electrode exhibits excellent rate capability, indicating that it may be applied to the high-power LIBs as a flexible, high areal capacity, binder-free and free-standing anode.

Diesel cold flow evaluation using design of experiment

It is very important to supply the diesel fuel from fuel tank to combustion chamber in case of cold start procedure. Paraffin hydrocarbons are easily solidified at low fuel temperature and it can block the fuel supply to the high pressure fuel pump. In order to reduce the fuel crystallization (Waxing), not only cold flow additives have been developed but also proper mounting design of fuel filter. Block heater in the fuel filter assembly have been also contained to improve the cold start and prevent blocking the fuel supply in Common Rail Direct Injection System. We need to make a test procedure of diesel cold flow evaluation to analyze the diesel cold flow characteristics. We can also obtain the design variables which have an effect to the diesel cold flow using the design of experiment and robust design. Finally the characteristics of diesel cold flow due to implementing cold flow evaluation test could be known.

Impaired glucose tolerance alters functional ability of peripheral blood-derived mononuclear cells in Asian Indian men.

To compare the adhesion, migration and endothelial differentiation potential of peripheral blood-derived mononuclear cells (PBMCs) obtained from drug-naive normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) Asian Indian men. Based on the 75-g oral glucose tolerance test, 30 NGT and 31 IGT subjects were recruited into the study. PBMCs were isolated from fasting blood using histopaque density gradient centrifugation. Isolated PBMCs were analysed for their ability to adhere to extracellular matrices, incorporation into tubular structures formed by matured endothelial cells and differentiation into endothelial cells upon 7-day culture in endothelial-specific growth medium. PBMCs obtained from IGT subjects exhibit poor adherence to fibronectin and reduced incorporation into tubular structures. Migration towards stromal cell-derived factor-1α (SDF-1α) in a trans-well filter assembly was also reduced for these cells. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis revealed decreased expression of CXCR4 and β2 integrin and increased expression of arginase II in IGT subjects. No differences were observed with regard to endothelial differentiation; however, cultured PBMCs of IGT subjects had decreased intracellular nitric oxide (NO) production. In pre-diabetic, Asian Indian men, PBMCs exhibit defective migration and homing potential.

디젤차량용 통합연료히터의 저온유동성 성능평가

It is very important to supply the diesel fuel from fuel tank to combustion chamber in case of cold start procedure. the paraffin hydrocarbons are easily solidified at low fuel temperature and it can be blocking the fuel supply to the high pressure fuel pump. In order to reduce the fuel crystallization (Waxing), it have been used to develop not only cold flow additives but also the proper mounting design of fuel filter. Block heater in the fuel filter assembly have been also contained to improve the cold start and prevent blocking the fuel supply in Common Rail Direct Injection System. we can obtain the fuel pressure drop and fuel flow rate, power consumption of fuel heater to have the cold flow evaluation test with the saperated and composited fuel heater at the low ambient temperature, Due to evaluating cold flow performance of two block heater, we knew that composited package fuel heater was the excellent cold flow performance compared to separated type and obtained the parameters of cold flow.

JPCAM: A 1.2 GPIXEL CAMERA FOR THE J-PAS SURVEY

JPCam is a 14-CCD mosaic camera, using the new e2v 9k-by-9k 10 μm-pixel 16-channel detectors, to be deployed on a dedicated 2.55 m wide-field telescope at the OAJ (Observatorio Astrofísico de Javalambre) in Aragon, Spain. The camera is designed to perform a Baryon Acoustic Oscillations (BAO) survey of the northern sky. The J-PAS survey strategy will use 54 relatively narrow-band (~ 13.8 nm) filters equi-spaced between 370 and 920 nm plus 3 broad-band filters to achieve unprecedented photometric red-shift accuracies for faint galaxies over ~8000 square degrees of sky. The cryostat, detector mosaic and read electronics, is being supplied by e2v under contract to J-PAS while the mechanical structure, housing the shutter and filter assembly, is being designed and constructed by a Brazilian consortium led by INPE (Instituto Nacional de Pesquisas Espaciais). The cryostat is bridged to the telescope via a hexapod actuator system to maintain image quality across the field. Four sets of 14 filters are placed in the ambient environment, just above the dewar window but directly in line with the detectors, leading to a mosaic having ~ 10 mm gaps between each CCD. The massive 500 mm aperture shutter is expected to be supplied by the Bonn-Shutter UG. We will present an overview of JPCam, from the filter configuration through to the CCD mosaic camera. A brief outline of the main J-PAS science projects will be included.

Note: Cryogenic coaxial microwave filters

The careful filtering of microwave electromagnetic radiation is critical for controlling the electromagnetic environment for experiments in solid-state quantum information processing and quantum metrology at millikelvin temperatures. We describe the design and fabrication of a coaxial filter assembly and demonstrate that its performance is in excellent agreement with theoretical modelling. We further perform an indicative test of the operation of the filters by making current-voltage measurements of small, underdamped Josephson junctions at 15 mK.

Aerosol emission monitoring in the production of silicon carbide nanoparticles by induction plasma synthesis

In this study, the synthesis of silicon carbide (SiC) nanoparticles in a prototype inductively coupled thermal plasma reactor and other supporting processes, such as the handling of precursor material, the collection of nanoparticles, and the cleaning of equipment, were monitored for particle emissions and potential worker exposure. The purpose of this study was to evaluate the effectiveness of engineering controls and best practice guidelines developed for the production and handling of nanoparticles, identify processes which result in a nanoparticle release, characterize these releases, and suggest possible administrative or engineering controls which may eliminate or control the exposure source. No particle release was detected during the synthesis and collection of SiC nanoparticles and the cleaning of the reactor. This was attributed to most of these processes occurring in closed systems operated at slight underpressure. Other tasks occurring in more open spaces, such as the disconnection of a filter assembly from the reactor system and the use of compressed air for the cleaning of filters where synthesized SiC nanoparticles were collected, resulted in releases of submicrometer particles with a mode size of ~170–180 nm. Observation of filter samples under scanning electron microscope confirmed that the particles were agglomerates of SiC nanoparticles.

Mesophase pitch-based carbon fiber spinning through a filter assembly and the microstructure evolution mechanism

A filter assembly in the upper stream of the spinneret was used to disturb the mesophase pitch (MP) melt flow during the spinning of precursor fibers. We studied the microstructure evolution mechanism of the MP-based carbon fibers during this process. Results showed that the use of filter assembly had a significant effect on the size of the split in the cross-section of carbon fibers. The split has been completely depressed in the carbon fibers spun with 50 layers of plain-weave. Selected area electron diffraction results showed that carbon fibers spun with 50 layers of plain-weave screens exhibited an apparent decrease of the orientational order of the (002) diffraction plane in both center and transition regions. The results of Raman spectroscopy indicated that, the size of graphitic microcrystalline domain in carbon fibers decreased with increasing the number of plain-weave screens in the filter assembly. Our studies confirmed the roles of the filter assembly in precursor fiber spinning to disrupt the mesophase domain formation in the MP melt and thus induce a reduced domain size.

Structure Design of Closed-Loop Rotary Steerable Drilling Tools

Rotating automatic steerable drilling technology is a new automated drilling technology developed in the early 1990s, which is an important aspect of the development of drilling technology in today's world. The basic structure of closed-loop rotary drilling tools is designed and basic structure of hydraulic thrust control system which greatly saves the time for hydraulic oil flowing back into the tank is innovatively designed based on Auto Trak RCLS (Baker Hughes). The structure of closed-loop rotary steering drilling tools, hydraulic thrust control system principle diagram, basic structure of hydraulic thrust control system and basic structure of flow pressure differential control valve and basic structure of oil filter assembly are rendered by AutoCAD drawing software.

A simulation of neural coding and auditory frequency analysis

Our understanding of the neural mechanisms underlying the very fine auditory frequency discrimination exhibited by listeners remains far from complete. To investigate this question we developed a functional model of the cochlear process in sufficient detail to allow the simulation of the principal characteristics of the cochlea's response to multi-tone and noise stimuli over a wide range of input levels. The model simulates level-dependent changes in frequency selectivity, combination-tone distortion, tone-on-tone suppression and masking, adaptation, and critical-band masking. The model is structured as 3000 channels, each consisting of a basilar membrane bandpass filter and inner-hair cell assembly. Input to each channel is the stapes displacement signal, and the output consists of ten independent stochastic point processes that are transmitted to the CNS on auditory-nerve fibers (ANFs). Our main purpose is to address these questions: (1) What narrowband spectrum information is available in the cochlea output? (2) How is this information encoded on the ANFs? (3) How might it be decoded in the CNS? An analysis of ensemble coding of the cochlear output showed that the precision (signal-to-noise ratio) of the information decoded by the CNS frequency analysis is directly related to the bandwidth of the basilar membrane filters.

An Integrated X-Ray/Optical Tomography System for Pre-clinical Radiation Research.

The current Small Animal Radiation Research Platform (SARRP) is poor for localizing small soft tissue targets for irradiation or tumor models growing in a soft tissue environment. Therefore, an imaging method complementary to x-ray CT is required to localize the soft tissue target's Center of Mass (CoM) to within 1 mm. In this paper, we report the development of an integrated x-ray/bioluminescence imaging/tomography (BLI/BLT) system to provide a pre-clinical, high resolution irradiation system. This system can be used to study radiation effects in small animals under the conebeam computed tomography (CBCT) imaging guidance by adding the bioluminescence imaging (BLI) system as a standalone system which can also be docked onto the SARRP. The proposed system integrates two robotic rotating stages and an x-ray source rated at maximum 130 kVp and having a small variable focal spot. A high performance and low noise CCD camera mounted in a light-tight housing along with an optical filter assembly is used for multi-wavelength BL tomography. A three-mirror arrangement is implemented to eliminate the need of rotating the CCD camera for acquiring multiple views. The mirror system is attached to a motorized stage to capture images in angles between 0-90° (for the standalone system). Camera and CBCT calibration are accomplished.

Indigenous technology development and standardization of the process for obtaining ready to use sterile sodium pertechnetate-Tc-99m solution from Geltech generator

Purpose of the Study:The indigenous design and technology development for processing large scale zirconium molybdate-Mo-99 (ZrMo-99) Geltech generator was successfully commissioned in Board of Radiation and Isotope Technology (BRIT), India, in 2006. The generator production facility comprises of four shielded plant facilities equipped with tongs and special process gadgets amenable for remote operations for radiochemical processing of ZrMo-99 gel.Results:Over 2800 Geltech generators have been processed and supplied to user hospitals during the period 2006-2013. Geltech generator supplied by BRIT was initially not sterile. Simple elution of Tc-99m is performed by a sterile evacuated vial with sterile and pyrogen free 0.9% NaCl solution to obtain sodium (Tc-99m) pertechnetate solution. A special type online 0.22 μm membrane filter has been identified and adapted in Geltech generator.Conclusions:The online filtration of Tc-99m from Geltech generator; thus, provided sterile Tc-99m sodium pertechnetate solution. Generators assembled with modified filter assembly were supplied to local hospital in Mumbai Radiation Medicine Centre (RMC) and S.G.S. Medical College and KEM Hospital) and excellent performances were reported by users.

Focus on materials

Focus on materials

In Vitro Investigation of the Effect of Ambient Humidity on Regional Delivered Dose with Solution and Suspension MDIs

Existing literature has shown that high relative humidity (RH) affects in vitro aerosol drug delivery of nebulizer and pressurized metered dose inhaler (pMDI) formulations. The aim of this study is to investigate in vitro mouth-throat deposition and lung delivery of selected solution and suspension pMDI formulations, under a range of RH, temperature, and flow rate conditions. The Alberta Idealized Throat was connected to a collection filter and placed in an environmental control chamber. The formulations selected were beclomethasone dipropionate (BDP) in 13% w/w ethanol/1.3% w/w glycerol and HFA-134a propellant solution ("BDP HFA134a"), BDP in 13% w/w ethanol and HFA-227 propellant solution ("BDP HFA227"), and Flixotide Evohaler (fluticasone propionate 250 μg/dose in HFA-134a suspension). Each of these pMDI formulations was dispersed into the mouth-throat and filter assembly in triplicate, according to an experimental matrix consisting of the following conditions: air flow rates of 28.3, 60, and 90 L/min; 0%, 35%, and 80% RH; operating temperatures of 20°C and 40°C. There was a general increase in mouth-throat deposition and corresponding decrease in filter deposition (representing lung dose fraction), with increasing RH for both BDP HFA134a and Flixotide pMDIs. Increasing temperature from 20°C to 40°C resulted in decreased mouth-throat deposition and increased lung dose fraction for the solution pMDIs, but generally no effect for the suspension pMDI. Not only is the dose delivery of pMDI formulations affected by environmental conditions (in some cases causing up to 50% reduction in lung delivery), but solution and suspension formulations also behave differently in response to these conditions. These results have implications during dosage form design, testing, and for usage patient use.

Soller slit design and characteristics

For X-ray absorption spectroscopy, either in transmission mode with concentrated samples or for dilute samples in fluorescence mode, it is advantageous to improve the signal-to-noise ratio by implementing a slit apparatus. Several investigations into the improvement of measurements when slits and filters are employed have been reported; however, these have always been for a particular design and are not transferable between dissimilar systems. A generalized approach to Soller slit design will be presented which enables a target level of noise rejection to be achieved by varying the number, size and placement of the filter and Soller slit assembly. A procedure for determining the reduction in efficiency of the Soller slits with respect to misalignment with the sample will also be discussed.

Understanding adhesives for filter fabrication

Up and down the production line at filter manufacturing plants, adhesives are mixed, extruded and coated onto components. Given the vital role of adhesives in filter assembly, filter manufacturers want to know more about them. Hugh Evans of Franklin Adhesives & Polymers provides some basic information to aid understanding and selection of the right adhesive technologies for specific bonding applications in filter manufacturing plants.

QMS in the Third Stability Zone with a Transverse Magnetic Field Applied

We report here a study using a quadrupole mass spectrometer (QMS) in which a static magnetic field is applied transversely to the body of the mass filter operating in stability zone 3. Significant improvement in QMS performance was obtained under certain magnetic field conditions, and these have been explained in terms of our theoretical model. The theoretical approach assumed in the model is that the QMS contains hyperbolic rods as electrodes and that the magnetic field acts over the full length of the mass filter assembly. Our latest analysis also predicts for what values of operating parameters an enhancement of the quadrupole resolution is achieved when a transverse magnetic field is applied. The model predicts instrument resolution R > 5000 for Ar with a 100 mm long mass filter and R > 3500 for a HT and D(2) mixture with a 200 mm long mass filter via application of a transverse magnetic field.