The high-risk polytrauma patient and inferior vena cava filter use.

PubMed

Berber, Onur; Vasireddy, Aswin; Nzeako, Obi; Tavakkolizadeh, Adel

2017-07-01

The aim of this study was to assess the impact on practice of vena cava filter insertion guidelines (Eastern Association for the Surgery of Trauma: practice management guidelines). The study was performed at a level 1 trauma centre with data from the 'Trauma Audit and Research Network' cross-referenced to hospital data. A total of 1138 specific 'high-risk' major trauma patients were identified over a 6-year period. The mean age was 46 years (18-102) and the male to female ratio was 3.3:1. The average Injury Severity Score was 23.6 (4-75). The overall DVT rate was 2.6% and the PE rate was 1.8%. A retrievable IVC filter was inserted in 42 cases (3.8%). The filter retrieval rate was 23.8% at a mean of 68.5days (4-107). Only one complication was reported of a breakthrough PE despite filter. Applying the EAST guidelines to this cohort would have suggested filter insertion in 279 (24.6%) cases. The kappa concordance value between observed practice and the 'EAST filter group' was 0.103 (poor). The PE rate in the 'EAST filter group' was 2.2% vs 1.6% in the 'no filter group' (p=0.601, no statistical difference) and the observed odds ratio was 0.814 (95% CI 0.413, 1.602). The EAST guidelines are useful but may be overestimating the need for filter insertion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Infrared floodlight assembly

DOEpatents

Wierzbicki, Julian J.; Chakrabarti, Kirti B.

1987-09-22

An infrared floodlight assembly (10) including a cast aluminum outer housing (11) defining a central chamber (15) therein. A floodlight (14), having a tungsten halogen lamp as the light source, is spacedly positioned within a heat conducting member (43) within chamber (15) such that the floodlight is securedly positioned in an aligned manner relative to the assembly's filter (35) and lens (12) components. The invention also includes venting means (51) to allow air passage between the interior of the member (43) and the adjacent chamber (15), as well as engagement means (85) for engaging a rear surface of the floodlight (14) to retain it firmly against an internal flange of the member (43). A reflector (61), capable of being compressed to allow insertion or removal, is located within the heat conducting member's interior between the floodlight (14) and filter (35) to reflect infrared radiation toward the filter (35) and spaced lens (12).

Improvement of the radiographic method for measurement of effective energy of pulsed X-ray emission from a PF device for different anode's insert materials.

PubMed

Miremad, Seyed Milad; Shirani, Babak

2018-06-01

In this paper, effective energy of pulsed X-Ray emitted from a Mather-type plasma focus device in stored energy of 2.5 kJ with six different anode's insert materials was measured using radiographic method with attenuation filters. Since intensity and energy of X-ray beam were considerably changed with changing the insert material, the method was improved by using different filters simultaneously in all the experiments and selection of the best filter in each experiment according to the appropriate criteria. Effective energy of pulsed X-ray beam was measured 16, 28, 50, 51, 34 and 44 keV when aluminum, copper, zinc, tin, tungsten and lead were used as insert materials, and aluminum, copper, silver, silver, copper and lead were used as filters, respectively. Copyright © 2018 Elsevier Ltd. All rights reserved.

Disturbance of the inclined inserting-type sand fence to wind-sand flow fields and its sand control characteristics

NASA Astrophysics Data System (ADS)

Cheng, Jian-jun; Lei, Jia-qiang; Li, Sheng-yu; Wang, Hai-feng

2016-06-01

The inclined inserting-type sand fence is a novel sand retaining wall adopted along the Lanxin High-Speed Railway II in Xinjiang for controlling and blocking sand movement. To verify the effectiveness of the new fence structure for sand prevention, a wind tunnel test was used for flow field test simulation of the sand fence. The results indicate that the inclined inserting-type sand fence was able to deflect the flow of the sand and was able to easily form an upward slant acceleration zone on the leeward side of the sand fence. As shown by the percentage change in sand collection rates on the windward side and the leeward side of the sand fence, the sand flux per unit area at 4 m height in the slant upward direction increased on the leeward side of the inclined inserting-type sand fence. By comparing the flow fields, this site is an acceleration zone, which also reaffirms the correspondence of wind-sand flow fields with the spatial distribution characteristic of the wind-carried sand motion. The field sand collection data indicates that under the effects of the inclined inserting-type sand fence, the sandy air currents passing in front and behind the sand fence not only changed in quality, but the grain composition and particle size also significantly changed, suggesting that the inclined inserting-type sand fence has a sorting and filtering effect on the sandy air currents that passed through. The fence retained coarse particulates on the windward side and fine particulates within the shade of the wind on the leeward side.

UW Imaging of Seismic-Physical-Models in Air Using Fiber-Optic Fabry-Perot Interferometer.

PubMed

Rong, Qiangzhou; Hao, Yongxin; Zhou, Ruixiang; Yin, Xunli; Shao, Zhihua; Liang, Lei; Qiao, Xueguang

2017-02-17

A fiber-optic Fabry-Perot interferometer (FPI) has been proposed and demonstrated for the ultrasound wave (UW) imaging of seismic-physical models. The sensor probe comprises a single mode fiber (SMF) that is inserted into a ceramic tube terminated by an ultra-thin gold film. The probe performs with an excellent UW sensitivity thanks to the nanolayer gold film, and thus is capable of detecting a weak UW in air medium. Furthermore, the compact sensor is a symmetrical structure so that it presents a good directionality in the UW detection. The spectral band-side filter technique is used for UW interrogation. After scanning the models using the sensing probe in air, the two-dimensional (2D) images of four physical models are reconstructed.

Establishment of an inferior vena cava filter database and interventional radiology led follow-up - retrieval rates and patients lost to follow-up.

PubMed

Klinken, Sven; Humphries, Charlotte; Ferguson, John

2017-10-01

To evaluate the rates of inferior vena cava (IVC) filter retrieval and the number of patient's lost to follow-up, before and after the establishment of an IVC filter database and interventional radiology (inserting physician) led follow-up. On the 1st of June 2012, an electronic interventional radiology database was established at our Institution. In addition, the interventional radiology team took responsibility for follow-up of IVC filters. Data were prospectively collected from the database for all patients who had an IVC filter inserted between the 1st June 2012 and the 31st May 2014. Data on patients who had an IVC filter inserted between the 1st of June 2009 to the 31st of May 2012 were retrospectively reviewed. Patient demographics, insertion indications, filter types, retrieval status, documented retrieval decisions, time in situ, trackable events and complications were obtained in the pre-database (n = 136) and post-database (n = 118) cohorts. Attempted IVC filter retrieval rates were improved from 52.9% to 72.9% (P = 0.001) following the establishment of the database. The number of patients with no documented decision (lost to follow-up) regarding their IVC filter reduced from 31 of 136 (23%) to 0 of 118 patients (P = < 0.001). There was a non-significant reduction in IVC filter dwell time in the post-database group (113 as compared to 137 days, P = 0.129). Following the establishment of an IVC filter database and interventional radiology led follow-up, we demonstrate a significant improvement in the attempted retrieval rates of IVC filters and the number of patient's lost to follow-up. © 2017 The Royal Australian and New Zealand College of Radiologists.

Thermo-mechanical analysis of a user filter assembly for undulator/wiggler operations at the Advanced Photon Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nian, H.L.T.; Kuzay, T.M.; Collins, J.

1996-12-31

This paper reports a thermo-mechanical study of a beamline filter (user filter) for undulator/wiggler operations. It is deployed in conjunction with the current commissioning window assembly on the APS insertion device (ID) front ends. The beamline filter at the Advanced Photon Source (APS) will eventually be used in windowless operations also. Hence survival and reasonable life expectancy of the filters under intense insertion device (ID) heat flu are crucial to the beamline operations. To accommodate various user requirements, the filter is configured to be a multi-choice type and smart to allow only those filter combinations that will be safe tomore » operate with a given ring current and beamline insertion device gap. However, this paper addresses only the thermo-mechanical analysis of individual filter integrity and safety in all combinations possible. The current filter design is configured to have four filter frames in a cascade with each frame holding five filters. This allows a potential 625 total filter combinations. Thermal analysis for all of these combinations becomes a mammoth task considering the desired choices for filter materials (pyrolitic graphite and metallic filters), filter thicknesses, undulator gaps, and the beam currents. The paper addresses how this difficult task has been reduced to a reasonable effort and computational level. Results from thermo-mechanical analyses of the filter combinations are presented both in tabular and graphical format.« less

Indications, complications and outcomes of inferior vena cava filters: A retrospective study.

PubMed

Wassef, Andrew; Lim, Wendy; Wu, Cynthia

2017-05-01

Inferior vena cava filters are used to prevent embolization of a lower extremity deep vein thrombosis when the risk of pulmonary embolism is thought to be high. However, evidence is lacking for their benefit and guidelines differ on the recommended indications for filter insertion. The study aim was to determine the reasons for inferior vena cava filter placement and subsequent complication rate. A retrospective cohort of patients receiving inferior vena cava filters in Edmonton, Alberta, Canada from 2007 to 2011. Main outcome was the indication of inferior vena cava filter insertion. Other measures include baseline demographic and medical history of patients, clinical outcomes and filter retrieval rates. 464 patients received inferior vena cava filters. An acute deep vein thrombosis with a contraindication to anticoagulation was the indication for 206 (44.4%) filter insertions. No contraindication to anticoagulation could be identified in 20.7% of filter placements. 30.6% were placed in those with active cancer, in which mortality was significantly higher. Only 38.9% of retrievable filters were successfully retrieved. Inferior vena cava filters were placed frequently in patients with weak or no guideline-supported indications for filter placement and in up to 20% of patients with no contraindication to anticoagulation. The high rates of cancer and the high mortality rate of the cohort raise the possibility that some filters are placed inappropriately in end of life settings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radiological/biological/aerosol removal system

DOEpatents

Haslam, Jeffery J

2015-03-17

An air filter replacement system for existing buildings, vehicles, arenas, and other enclosed airspaces includes a replacement air filter for replacing a standard air filter. The replacement air filter has dimensions and air flow specifications that allow it to replace the standard air filter. The replacement air filter includes a filter material that removes radiological or biological or aerosol particles.

Tunable Microwave Filter Design Using Thin-Film Ferroelectric Varactors

NASA Astrophysics Data System (ADS)

Haridasan, Vrinda

Military, space, and consumer-based communication markets alike are moving towards multi-functional, multi-mode, and portable transceiver units. Ferroelectric-based tunable filter designs in RF front-ends are a relatively new area of research that provides a potential solution to support wideband and compact transceiver units. This work presents design methodologies developed to optimize a tunable filter design for system-level integration, and to improve the performance of a ferroelectric-based tunable bandpass filter. An investigative approach to find the origins of high insertion loss exhibited by these filters is also undertaken. A system-aware design guideline and figure of merit for ferroelectric-based tunable band- pass filters is developed. The guideline does not constrain the filter bandwidth as long as it falls within the range of the analog bandwidth of a system's analog to digital converter. A figure of merit (FOM) that optimizes filter design for a specific application is presented. It considers the worst-case filter performance parameters and a tuning sensitivity term that captures the relation between frequency tunability and the underlying material tunability. A non-tunable parasitic fringe capacitance associated with ferroelectric-based planar capacitors is confirmed by simulated and measured results. The fringe capacitance is an appreciable proportion of the tunable capacitance at frequencies of X-band and higher. As ferroelectric-based tunable capac- itors form tunable resonators in the filter design, a proportionally higher fringe capacitance reduces the capacitance tunability which in turn reduces the frequency tunability of the filter. Methods to reduce the fringe capacitance can thus increase frequency tunability or indirectly reduce the filter insertion-loss by trading off the increased tunability achieved to lower loss. A new two-pole tunable filter topology with high frequency tunability (> 30%), steep filter skirts, wide stopband rejection, and constant bandwidth is designed, simulated, fabricated and measured. The filters are fabricated using barium strontium titanate (BST) varactors. Electromagnetic simulations and measured results of the tunable two-pole ferroelectric filter are analyzed to explore the origins of high insertion loss in ferroelectric filters. The results indicate that the high-permittivity of the BST (a ferroelectric) not only makes the filters tunable and compact, but also increases the conductive loss of the ferroelectric-based tunable resonators which translates into high insertion loss in ferroelectric filters.

Sequential cooling insert for turbine stator vane

DOEpatents

Jones, Russel B

2017-04-04

A sequential flow cooling insert for a turbine stator vane of a small gas turbine engine, where the impingement cooling insert is formed as a single piece from a metal additive manufacturing process such as 3D metal printing, and where the insert includes a plurality of rows of radial extending impingement cooling air holes alternating with rows of radial extending return air holes on a pressure side wall, and where the insert includes a plurality of rows of chordwise extending second impingement cooling air holes on a suction side wall. The insert includes alternating rows of radial extending cooling air supply channels and return air channels that form a series of impingement cooling on the pressure side followed by the suction side of the insert.

Shoe inserts and orthotics for sport and physical activities.

PubMed

Nigg, B M; Nurse, M A; Stefanyshyn, D J

1999-07-01

The purposes of this paper were to discuss the perceived benefits of inserts and orthotics for sport activities and to propose a new concept for inserts and orthotics. There is evidence that inserts or orthotics reduce or prevent movement-related injuries. However, there is limited knowledge about the specific functioning an orthotic or insert provides. The same orthotic or insert is often proposed for different problems. Changes in skeletal movement due to inserts or orthotics seem to be small and not systematic. Based on the results of a study using bone pins, one may question the idea that a major function of orthotics or inserts consists in aligning the skeleton. Impact cushioning with shoe inserts or orthotics is typically below 10%. Such small reductions might not be important for injury reduction. It has been suggested that changes in material properties might produce adjustments in the muscular response of the locomotor system. The foot has various sensors to detect input signals with subject specific thresholds. Subjects with similar sensitivity threshold levels seem to respond in their movement pattern in a similar way. Comfort is an important variable. From a biomechanical point of view, comfort may be related to fit, additional stabilizing muscle work, fatigue, and damping of soft tissue vibrations. Based on the presented evidence, the concept of minimizing muscle work is proposed when using orthotics or inserts. A force signal acts as an input variable on the shoe. The shoe sole acts as a first filter, the insert or orthotic as a second filter, the plantar surface of the foot as a third filter for the force input signal. The filtered information is transferred to the central nervous system that provides a subject specific dynamic response. The subject performs the movement for the task at hand. For a given movement task, the skeleton has a preferred path. If an intervention supports/counteracts the preferred movement path, muscle activity can/must be reduced/increased. Based on this concept, an optimal insert or orthotic would reduce muscle activity, feel comfortable, and should increase performance.

Retrievable Inferior Vena Cava Filters: Indications, Indwelling Time, Removal, Success and Complication Rates.

PubMed

Tashbayev, Alisher; Belenky, Alexander; Litvin, Sergey; Knizhnik, Michael; Bachar, Gil N; Atar, Eli

2016-02-01

Various vena cava filters (VCF) are designed with the ability to be retrieved percutaneously. Yet, despite this option most of them remain in the inferior vena cava (IVC). To report our experience in the placement and retrieval of three different types of VCFs, and to compare the indications for their insertion and retrieval as reported in the literature. During a 5 year period three types of retrievable VCF (ALN, OptEase, and Celect) were inserted in 306 patients at the Rabin Medical Center (Beilinson and Hasharon hospitals). Indications, retrieval rates, median time to retrieval, success and complication rates were viewed and assessed in the three groups of filter types and were compared with the data of similar studies in the literature. Of the 306 VCFs inserted, 31 (10.1%) were retrieved with equal distribution in the three groups. In most patients the reason for filter insertion was venous thromboembolic events (VTE) and contraindications to anticoagulant therapy. Mean age was 68.38 ± 17.5 years (range 18-99) and was noted to be significantly higher compared to similar studies (53-56 years) (P < 0.0001). Multi-trauma patients were significantly older (71.11 ± 14.99 years) than post-pulmonary embolism patients (48.03 ± 20.98 years, P < 0.0001) and patients with preventive indication (26.00 ± 11.31, P < 0.0001). The mean indwelling time was 100.6 ± 103.399 days. Our results are comparable with the results of other studies, and there was no difference in percentage of retrieval or complications between patients in each of the three groups. In 1 of 10 patients filters should be removed after an average of 3.5 months. All three IVC filter types used are safe to insert and retrieve.

Apparatus for real-time airborne particulate radionuclide collection and analysis

DOEpatents

Smart, John E.; Perkins, Richard W.

2001-01-01

An improved apparatus for collecting and analyzing an airborne particulate radionuclide having a filter mounted in a housing, the housing having an air inlet upstream of the filter and an air outlet downstream of the filter, wherein an air stream flows therethrough. The air inlet receives the air stream, the filter collects the airborne particulate radionuclide and permits a filtered air stream to pass through the air outlet. The improvement which permits real time counting is a gamma detecting germanium diode mounted downstream of the filter in the filtered air stream. The gamma detecting germanium diode is spaced apart from a downstream side of the filter a minimum distance for a substantially maximum counting detection while permitting substantially free air flow through the filter and uniform particulate radionuclide deposition on the filter.

A vacuum-operated pore-water extractor for estuarine and freshwater sediments

USGS Publications Warehouse

Winger, Parley V.; Lasier, Peter J.

1991-01-01

A vacuum-operated pore-water extractor for estuarine and freshwater sediments was developed and constructed from a fused-glass air stone attached with aquarium airline tubing to a 30 or 60 cc polypropylene syringe. Pore water is extracted by inserting the air stone into the sediment and creating a vacuum by retracting and bracing the syringe plunger. A hand-operated vacuum pump attached to a filtration flask was also evaluated as an alternative vacuum source. The volume and time to extract pore water varies with the number of devices and the sediment particle size. Extraction time is longer for fine sediments than for sandy sediments. Four liters of sediment generally yield between 500 and 1,500 mL of pore water. The sediment that surrounds and accumulates on the air stone acts as a filter, and, except for the first few milliliters, the collected pore water is clear. Because there is no exposure to air or avenue for escape, volatile compounds andin situ characteristics are retained in the extracted pore water.

Guide wire entrapment by inferior vena cava filters: an experimental study.

PubMed

Rosen, Michael J; Burns, Justin M; Cobb, William S; Jacobs, David G; Heniford, B Todd; Sing, Ronald F

2005-09-01

In situ vena cava filters are at risk for complications with the use of J-tipped guide wires. The purpose of this study was to evaluate the impact of two commonly used J-tipped guide wires on the stability of the four most recently released vena cava filters in an in vitro flow model. Four filters (OptEase [F1], Günther Tulip [F2], Vena Tech LP [F3], and Recovery [F4]) were inserted into an in vitro flow model. Two J-tipped guide wires (0.032-inch [GW-1], 0.035-inch [GW-2]) were passed through each filter (n = 50 passes per wire) for a distance of 10 cm. The inserter was blind as to the effects of the wire. The filters were monitored by an independent observer for adverse events occurring between the filters and the guide wires. These were defined as: migrations (>1 cm), change of position (tilt>10 degrees), and entrapment of the wire (unable to remove wire). Descriptive statistics, chi-square, and Fisher's exact test were used (p < 0.05 considered significant). GW-1 resulted in a lower incidence of entrapment, migration, and tilt for all filters compared with GW-2 (F1, p = 0.003; F2, p < 0.0001; F3, p < 0.0001; F4, p = 0.0004). GW-1 resulted in entrapment in 0%, migration in 7.5%, and tilt in 10.5% of insertions. GW-2 resulted in entrapment in 1%, migration in 26.5%, and tilt in 5.5% of insertions. The incidence of adverse events for GW-1 was significantly different compared with all filters (F1, 0%; F2, 46%; F3, 4%; and F4, 22%; p < 0.0001). Similarly, the incidence of adverse events for GW-2 was significantly different when evaluating all filters (F1, 12%; F2, 48%; F3, 22%; F4 60%; p < 0.0001). The smaller-diameter guide wire resulted in a decreased incidence of adverse events for all filters, but there is still risk for complications. Knowledge of potential complications associated with vena cava filters and the postinsertion use of guide wires are essential to avoid potential mishaps.

Acid-Soluble Internal Capsules for Closed-Face Cassette Elemental Sampling and Analysis of Workplace Air

PubMed Central

Harper, Martin; Ashley, Kevin

2013-01-01

Airborne particles that are collected using closed-face filter cassettes (CFCs), which are used widely in the sampling of workplace aerosols, can deposit in places other than on the filter and thereby may not be included in the ensuing analysis. A technique for ensuring that internal non-filter deposits are included in the analysis is to collect airborne particles within an acid-soluble internal capsule that, following sampling, can be dissolved along with the filter for subsequent elemental analysis. An interlaboratory study (ILS) was carried out to evaluate the use of cellulosic CFC capsule inserts for their suitability in the determination of trace elements in airborne samples. The ILS was performed in accordance with an applicable ASTM International standard practice, ASTM E691, which describes statistical procedures for investigating interlaboratory precision. Performance evaluation materials consisted of prototype cellulose acetate capsules attached to mixed-cellulose ester filters. Batches of capsules were dosed with Pb-containing materials (standard aqueous solutions, and certified reference material soil and paint). Also, aerosol samples containing nine target analyte elements (As, Cd, Co, Cr, Cu, Fe, Pb, Mn, and Ni) were generated using a multiport sampler; various concentrations and sampling times were employed to yield samples fortified at desired loading levels. Triplicates of spiked capsules at three different loadings were conveyed to each volunteer laboratory; loading levels were unknown to the participants. The laboratories were asked to prepare the samples by acid dissolution and to analyze aliquots of extracted samples by atomic spectrometry in accordance with applicable ASTM International Standards. Participants were asked to report their results in units of μg of each target element per sample. For the elements investigated, interlaboratory precision and recovery estimates from the participating laboratories demonstrated the utility of the cellulosic capsule inserts for the measurement of sampled trace elements. PMID:23548078

Guide to Air Cleaners in the Home

MedlinePlus

... In-duct Particle Removal Flat or panel air filters Pleated or extended surface filters In-duct Gaseous Pollutant Removal In-duct Pollutant ... can remove particles from the air — mechanical air filters and electronic air cleaners. Mechanical air filters remove ...

A single center experience with retrievable IVC filters.

PubMed

Renno, Anas; Khateeb, Faisal; Kazan, Viviane; Qu, Weikai; Gollapudi, Anurekha; Aplin, Brett; Abbas, Jihad; Zelenock, Gerald; Nazzal, Munier

2015-08-01

To evaluate retrievable IVC filters in our institution and assess their retrieval following a well-structured follow up program. Retrospective cohort study. The medical records of patients implanted with retrievable IVC filters were reviewed. All retrievable filter insertions between July 2007 and August 2011 at our institution were reviewed. Data was analyzed for age, gender, indication, complications, retrieval rate, and brand of filter inserted. Statistical analysis was done using SPSS software v19. Chi-square was used to compare discrete data and t-test for continuous data. P < 0.05 was significant. A total of 484 patients were reviewed of which 258 (53.1%) had a complete medical record. And 96 (37.2%) filters were placed as permanent at the time of insertion. An additional 40 (15.5%) filters were converted to permanent (total permanent filters 136; 52.7%). Death was reported in 26 (10%) patients and 96 (37.2%) out of the remaining 232 patients presented for potential retrieval. Also, 73 (28.2%) had an attempt to retrieve the filters, 69 (94.5%) were successful and 4 (5.4%) failed to retrieve. The remaining 23 (8.9%) patients declined retrieval. Filters studied include Celect (38%), Bard (31.4%), Option (26.2%), Tulip (4.1%), and Recovery (0.2%). Bard was more commonly used as a retrievable filter (80.9%). Retrieval on the first attempt was 90.4% (n = 66) successful. Of the remaining seven filters, three were successfully retrieved on a second attempt, and four failed to retrieve due to filter tilt. The success rates of retrieval for Celect and Tulip were significantly lower than for Bard (p = 0.04 and 0.023, respectively). Our study showed that a variety of IVC filters can be retrieved successfully with minimal complication rates. In more than half of our patients, IVC filters were used as permanent. Failure of retrieval was most frequently due to filter tilting. © The Author(s) 2014.

Performance of a high Tc superconducting ultralow-loss microwave stripline filter

NASA Technical Reports Server (NTRS)

Zahopoulos, C.; Sridhar, S.; Bautista, J. J.; Ortiz, G.; Lanagan, M.

1991-01-01

The successful fabrication is reported of a five-pole interdigital stripline filter made of the 93 K superconductor Y1Ba2Cu3O(y) coated on a silver substrate, with a center frequency of 8.5 GHz and an extremely high rejection ratio of 80 dB. The lowest insertion loss measured was 0.1 dB at 12 K, with a return loss better than 16 dB, representing significant improvements over a similar Cu filter, and comparable to low Tc filters. The insertion loss appears to be limited by extrinsic factors such as tuning mismatch and joint losses, and not by the superconducting material losses.

Self-pressurized air-Q® intubating laryngeal airway versus the LMA® Classic™: a randomized clinical trial.

PubMed

Ha, Sang Hee; Kim, Min-Soo; Suh, Jiwoo; Lee, Jong Seok

2018-05-01

The self-pressurized air-Q® (air-Q SP) intubating laryngeal airway is a relatively new supraglottic airway (SGA) device. The intracuff pressure of air-Q dynamically equilibrates with the airway pressure and adjusts to the patient's pharyngeal and periglottic anatomy, potentially providing improved airway fit and seal. The aim of this prospective randomized study was to compare the clinical performance of air-Q to the LMA® Classic™ SGA. Adult patients requiring general anesthesia for elective surgery were prospectively enrolled and randomly assigned to either air-Q SP or the LMA Classic SGA. Oropharyngeal leak pressure (primary endpoint), success rate, insertion features (insertion time, ease of insertion, requirement for device manipulation), sealing function, gastric insufflation, bronchoscopic view, and oropharyngeal complications at device insertion and following its removal (sore throat, dysphagia, dysphonia) were compared. The mean (standard deviation [SD]) oropharyngeal leak pressure just after insertion was similar in the air-Q SP and LMA [16.8 (4.9) vs 18.6 (5.5) cm H 2 O, respectively; mean difference, 1.8 cm H 2 O; 95% CI, -0.5 to 4.2; P = 0.13] and did not differ at ten minutes following device insertion. Median [interquartile range (IQR)] peak inspiratory pressure just after insertion was lower in the air-Q SP (11.0 [10.0-13.0] vs 13.0 [11.0-14.0] cmH 2 O, median difference, 1.0 cm H 2 O; 95% CI, 0.0 to 2.0; P = 0.03) but no difference was observed at ten minutes. The median [IQR] insertion time was faster with the air-Q SP (15.9 [13.6-20.3] sec vs 24 [21.2-27.1] sec; median difference, 8.1 sec; 95% CI, 5.6 to 9.9; P < 0.001) and improved bronchoscopic viewing grade were seen with the air-Q SP immediately after insertion (P < 0.001). No differences between the groups were observed with respect to the rate of successful insertion at first attempt, overall insertion success rate, ease of insertion, and complications. The air-Q SP had similar leak pressures but a faster insertion time and superior bronchoscopic viewing grade when compared with the LMA Classic. The air-Q SP is a suitable alternative to the LMA Classic in adult patients and may be a superior conduit for tracheal intubation. www.clinicaltrials.gov (NCT02206438). Registered 1 August 2014.

Filter replacement lifetime prediction

DOEpatents

Hamann, Hendrik F.; Klein, Levente I.; Manzer, Dennis G.; Marianno, Fernando J.

2017-10-25

Methods and systems for predicting a filter lifetime include building a filter effectiveness history based on contaminant sensor information associated with a filter; determining a rate of filter consumption with a processor based on the filter effectiveness history; and determining a remaining filter lifetime based on the determined rate of filter consumption. Methods and systems for increasing filter economy include measuring contaminants in an internal and an external environment; determining a cost of a corrosion rate increase if unfiltered external air intake is increased for cooling; determining a cost of increased air pressure to filter external air; and if the cost of filtering external air exceeds the cost of the corrosion rate increase, increasing an intake of unfiltered external air.

Optical add/drop filter for wavelength division multiplexed systems

DOEpatents

Deri, Robert J.; Strand, Oliver T.; Garrett, Henry E.

2002-01-01

An optical add/drop filter for wavelength division multiplexed systems and construction methods are disclosed. The add/drop filter includes a first ferrule having a first pre-formed opening for receiving a first optical fiber; an interference filter oriented to pass a first set of wavelengths along the first optical fiber and reflect a second set of wavelengths; and, a second ferrule having a second pre-formed opening for receiving the second optical fiber, and the reflected second set of wavelengths. A method for constructing the optical add/drop filter consists of the steps of forming a first set of openings in a first ferrule; inserting a first set of optical fibers into the first set of openings; forming a first set of guide pin openings in the first ferrule; dividing the first ferrule into a first ferrule portion and a second ferrule portion; forming an interference filter on the first ferrule portion; inserting guide pins through the first set of guide pin openings in the first ferrule portion and second ferrule portion to passively align the first set of optical fibers; removing material such that light reflected from the interference filter from the first set of optical fibers is accessible; forming a second set of openings in a second ferrule; inserting a second set of optical fibers into the second set of openings; and positioning the second ferrule with respect to the first ferrule such that the second set of optical fibers receive the light reflected from the interference filter.

Disinfecting Filters For Recirculated Air

NASA Technical Reports Server (NTRS)

Pilichi, Carmine A.

1992-01-01

Simple treatment disinfects air filters by killing bacteria, algae, fungi, mycobacteria, viruses, spores, and any other micro-organisms filters might harbor. Concept applied to reusable stainless-steel wire mesh filters and disposable air filters. Treatment used on filters in air-circulation systems in spacecraft, airplanes, other vehicles, and buildings to help prevent spread of colds, sore throats, and more-serious illnesses.

An L-section DC electric field switchable bulk acoustic wave solidly mounted resonator filter based on Ba0.5Sr0.5TiO3.

PubMed

Saddik, George N; York, Robert A

2012-09-01

This paper reports on the modeling, fabrication, and experimental results of a voltage switchable barium strontium titanate solidly mounted resonator filter at 6 GHz. The filter insertion loss was measured to be -4.26 dB and the return loss to be -13.5 dB. The 3-dB bandwidth was measured to be 72 MHz and the quality factor was calculated to be 83. The data were collected at a dc bias voltage of 10 V. Temperature data were also collected, and the filter demonstrated a 0.71-dB increase in insertion loss and a 7-MHz decrease in center frequency with increase in temperature.

Capability of air filters to retain airborne bacteria and molds in heating, ventilating and air-conditioning (HVAC) systems.

PubMed

Möritz, M; Peters, H; Nipko, B; Rüden, H

2001-07-01

The capability of air filters (filterclass: F6, F7) to retain airborne outdoor microorganisms was examined in field experiments in two heating, ventilating and air conditioning (HVAC) systems. At the beginning of the 15-month investigation period, the first filter stages of both HVAC systems were equipped with new unused air filters. The number of airborne bacteria and molds before and behind the filters were determined simultaneously in 14 days-intervals using 6-stage Andersen cascade impactors. Under relatively dry (< 80% R. H.) and warm (> 12 degrees C) outdoor air conditions air filters led to a marked reduction of airborne microorganism concentrations (bacteria by approximately 70% and molds by > 80%). However, during long periods of high relative humidity (> 80% R. H.) a proliferation of bacteria on air filters with subsequent release into the filtered air occurred. These microorganisms were mainly smaller than 1.1 microns therefore being part of the respirable fraction. The results showed furthermore that one possibility to avoid microbial proliferation is to limit the relative humidity in the area of the air filters to 80% R. H. (mean of 3 days), e.g. by using preheaters in front of air filters in HVAC-systems.

Retrievable Günther Tulip Vena Cava Filter in the prevention of pulmonary embolism in patients with acute deep venous thrombosis in perinatal period.

PubMed

Köcher, Martin; Krcova, Vera; Cerna, Marie; Prochazka, Martin

2009-04-01

To evaluate the feasibility and efficacy of the retrievable Günther Tulip Vena Cava Filter in the prevention of pulmonary embolism in patients with acute deep vein thrombosis in the perinatal period and to discuss the technical demands associated with the filter's implantation and retrieval. Between 1996 until 2007, eight women (mean age 27.4 years, range 20-42 years) with acute deep iliofemoral venous thrombosis in the perinatal period of pregnancy and increased risk of pulmonary embolism during delivery were indicated for retrievable Günther Tulip Vena Cava Filter implantation. All filters were inserted and removed under local anesthesia from the jugular approach. The Günther Tulip Vena Cava Filter was implanted suprarenally in all patients on the day of caesarean delivery. In follow-up cavograms performed just before planned filter removal, no embolus was seen in the filter in any patient. In all patients the filter was retrieved without complications on the 12th day after implantation. Retrievable Günther Tulip Vena Cava Filters can be inserted and removed in patients during the perinatal period without major complications.

Correlation of Electric Field and Critical Design Parameters for Ferroelectric Tunable Microwave Filters

NASA Technical Reports Server (NTRS)

Subramanyam, Guru; VanKeuls, Fred W.; Miranda, Felix A.; Canedy, Chadwick L.; Aggarwal, Sanjeev; Venkatesan, Thirumalai; Ramesh, Ramamoorthy

2000-01-01

The correlation of electric field and critical design parameters such as the insertion loss, frequency ability return loss, and bandwidth of conductor/ferroelectric/dielectric microstrip tunable K-band microwave filters is discussed in this work. This work is based primarily on barium strontium titanate (BSTO) ferroelectric thin film based tunable microstrip filters for room temperature applications. Two new parameters which we believe will simplify the evaluation of ferroelectric thin films for tunable microwave filters, are defined. The first of these, called the sensitivity parameter, is defined as the incremental change in center frequency with incremental change in maximum applied electric field (EPEAK) in the filter. The other, the loss parameter, is defined as the incremental or decremental change in insertion loss of the filter with incremental change in maximum applied electric field. At room temperature, the Au/BSTO/LAO microstrip filters exhibited a sensitivity parameter value between 15 and 5 MHz/cm/kV. The loss parameter varied for different bias configurations used for electrically tuning the filter. The loss parameter varied from 0.05 to 0.01 dB/cm/kV at room temperature.

Carbon fiber composite molecular sieve electrically regenerable air filter media

DOEpatents

Wilson, K.A.; Burchell, T.D.; Judkins, R.R.

1998-10-27

An electrically regenerable gas filter system includes a carbon fiber composite molecular sieve (CFCMS) filter medium. After a separate medium-efficiency pre-filter removes particulate from the supply air stream, the CFCMS filter sorbs gaseous air pollutants before the air is recirculated to the space. When saturated, the CFCMS media is regenerated utilizing a low-voltage current that is caused to pass through the filter medium. 3 figs.

ARRANGEMENT FOR REPLACING FILTERS

DOEpatents

Blomgren, R.A.; Bohlin, N.J.C.

1957-08-27

An improved filtered air exhaust system which may be continually operated during the replacement of the filters without the escape of unfiltered air is described. This is accomplished by hermetically sealing the box like filter containers in a rectangular tunnel with neoprene covered sponge rubber sealing rings coated with a silicone impregnated pneumatic grease. The tunnel through which the filters are pushed is normal to the exhaust air duct. A number of unused filters are in line behind the filters in use, and are moved by a hydraulic ram so that a fresh filter is positioned in the air duct. The used filter is pushed into a waiting receptacle and is suitably disposed. This device permits a rapid and safe replacement of a radiation contaminated filter without interruption to the normal flow of exhaust air.

Effectiveness of in-room air filtration and dilution ventilation for tuberculosis infection control.

PubMed

Miller-Leiden, S; Lobascio, C; Nazaroff, W W; Macher, J M

1996-09-01

Tuberculosis (TB) is a public health problem that may pose substantial risks to health care workers and others. TB infection occurs by inhalation of airborne bacteria emitted by persons with active disease. We experimentally evaluated the effectiveness of in-room air filtration systems, specifically portable air filters (PAFs) and ceiling-mounted air filters (CMAFs), in conjunction with dilution ventilation, for controlling TB exposure in high-risk settings. For each experiment, a test aerosol was continuously generated and released into a full-sized room. With the in-room air filter and room ventilation system operating, time-averaged airborne particle concentrations were measured at several points. The effectiveness of in-room air filtration plus ventilation was determined by comparing particle concentrations with and without device operation. The four PAFs and three CMAFs we evaluated reduced room-average particle concentrations, typically by 30% to 90%, relative to a baseline scenario with two air-changes per hour of ventilation (outside air) only. Increasing the rate of air flow recirculating through the filter and/or air flow from the ventilation did not always increase effectiveness. Concentrations were generally higher near the emission source than elsewhere in the room. Both the air flow configuration of the filter and its placement within the room were important, influencing room air flow patterns and the spatial distribution of concentrations. Air filters containing efficient, but non-high efficiency particulate air (HEPA) filter media were as effective as air filters containing HEPA filter media.

Effectiveness of In-Room Air Filtration and Dilution Ventilation for Tuberculosis Infection Control.

PubMed

Miller-Leiden, S; Lohascio, C; Nazaroff, W W; Macher, J M

1996-09-01

Tuberculosis (TB) is a public health problem that may pose substantial risks to health care workers and others. TB infection occurs by inhalation of airborne bacteria emitted by persons with active disease. We experimentally evaluated the effectiveness of in-room air filtration systems, specifically portable air filters (PAFs) and ceiling-mounted air filters (CMAFs), in conjunction with dilution ventilation, for controlling TB exposure in high-risk settings. For each experiment, a test aerosol was continuously generated and released into a full-sized room. With the in-room air filter and room ventilation system operating, time-averaged airborne particle concentrations were measured at several points. The effectiveness of in-room air filtration plus ventilation was determined by comparing particle concentrations with and without device operation. The four PAFs and three CMAFs we evaluated reduced room-average particle concentrations, typically by 30% to 90%, relative to a baseline scenario with two air-changes per hour of ventilation (outside air) only. Increasing the rate of air flow recirculating through the filter and/or air flow from the ventilation did not always increase effectiveness. Concentrations were generally higher near the emission source than elsewhere in the room. Both the air flow configuration of the filter and its placement within the room were important, influencing room air flow patterns and the spatial distribution of concentrations. Air filters containing efficient, but non-high efficiency particulate air (HEPA) filter media were as effective as air filters containing HEPA filter media.

A linear 180 nm SOI CMOS antenna switch module using integrated passive device filters for cellular applications

NASA Astrophysics Data System (ADS)

Jie, Cui; Lei, Chen; Peng, Zhao; Xu, Niu; Yi, Liu

2014-06-01

A broadband monolithic linear single pole, eight throw (SP8T) switch has been fabricated in 180 nm thin film silicon-on-insulator (SOI) CMOS technology with a quad-band GSM harmonic filter in integrated passive devices (IPD) technology, which is developed for cellular applications. The antenna switch module (ASM) features 1.2 dB insertion loss with filter on 2G bands and 0.4 dB insertion loss in 3G bands, less than -45 dB isolation and maximum -103 dB intermodulation distortion for mobile front ends by applying distributed architecture and adaptive supply voltage generator.

Transparent air filter for high-efficiency PM2.5 capture.

PubMed

Liu, Chong; Hsu, Po-Chun; Lee, Hyun-Wook; Ye, Meng; Zheng, Guangyuan; Liu, Nian; Li, Weiyang; Cui, Yi

2015-02-16

Particulate matter (PM) pollution has raised serious concerns for public health. Although outdoor individual protection could be achieved by facial masks, indoor air usually relies on expensive and energy-intensive air-filtering devices. Here, we introduce a transparent air filter for indoor air protection through windows that uses natural passive ventilation to effectively protect the indoor air quality. By controlling the surface chemistry to enable strong PM adhesion and also the microstructure of the air filters to increase the capture possibilities, we achieve transparent, high air flow and highly effective air filters of ~90% transparency with >95.00% removal of PM2.5 under extreme hazardous air-quality conditions (PM2.5 mass concentration >250 μg m(-3)). A field test in Beijing shows that the polyacrylonitrile transparent air filter has the best PM2.5 removal efficiency of 98.69% at high transmittance of ~77% during haze occurrence.

Transparent air filter for high-efficiency PM2.5 capture

NASA Astrophysics Data System (ADS)

Liu, Chong; Hsu, Po-Chun; Lee, Hyun-Wook; Ye, Meng; Zheng, Guangyuan; Liu, Nian; Li, Weiyang; Cui, Yi

2015-02-01

Particulate matter (PM) pollution has raised serious concerns for public health. Although outdoor individual protection could be achieved by facial masks, indoor air usually relies on expensive and energy-intensive air-filtering devices. Here, we introduce a transparent air filter for indoor air protection through windows that uses natural passive ventilation to effectively protect the indoor air quality. By controlling the surface chemistry to enable strong PM adhesion and also the microstructure of the air filters to increase the capture possibilities, we achieve transparent, high air flow and highly effective air filters of ~90% transparency with >95.00% removal of PM2.5 under extreme hazardous air-quality conditions (PM2.5 mass concentration >250 μg m-3). A field test in Beijing shows that the polyacrylonitrile transparent air filter has the best PM2.5 removal efficiency of 98.69% at high transmittance of ~77% during haze occurrence.

Phlegmasia Caerulea Dolens in a Patient With an Inferior Vena Cava Filter: Treatment of Massive Iliocaval Thrombosis Using Local Intravenous Catheter-Directed Thrombolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cookson, Daniel, E-mail: danielthomascookson@yahoo.co.uk; Caldwell, Stuart, E-mail: stuart.caldwell@middlemore.co.nz

Phlegmasia caerulea dolens (PCD) is a potentially disastrous complication of inferior vena cava filter insertion, and its optimum management has not been clearly established. We present a case report of a patient with pulmonary embolism and acute adrenal haemorrhage who developed PCD secondary to massive iliocaval thrombosis after insertion of a Cook Celect removable filter. Local intravenous catheter-directed thrombolysis (CDT), followed by systemic anticoagulation, achieved limb salvage and virtual resolution of symptoms at 3 months without complications. CDT can be a successful primary treatment of filter-associated PCD and can be safe in selected patients with acute nontraumatic haemorrhage. Systemic anticoagulationmore » may subsequently restore complete venous patency and may therefore be a useful approach to postthrombolysis management of residual iliocaval thrombus when filter removal is indicated.« less

Wavelength-tunable thulium-doped fiber laser by employing a self-made Fabry-Perot filter

NASA Astrophysics Data System (ADS)

Wang, Y. P.; Ju, Y. L.; Wu, C. T.; Liu, W.; Yang, C.

2017-06-01

In this demonstration, we proposed a novel wavelength-tunable thulium-doped fiber laser (TDFL) with a self-made Fabry-Perot (F-P) filter. When the F-P filter was not inserted, the maximum output power of 11.1 W was achieved when the pump power was 70.2 W. The corresponding optical-to-optical conversion efficiency was 15.8% and the slope efficiency was 22.1%. When the F-P filter was inserted, the output wavelength could be tuned from 1952.9 to 1934.9 nm with the change of cavity length of F-P filter which was fixed on a piezoelectric ceramic transducer (PZT) controlled by the voltage applied to it. The full width at half maximum (FWHM) was no more than 0.19 nm. Furthermore, the wavelength fluctuations of the tunable fiber laser were kept within  ±0.2 nm.

Sweat collection capsule

NASA Technical Reports Server (NTRS)

Delaplaine, R. W.; Greenleaf, J. E.

1979-01-01

Capsule, with filter paper insert, is used to collect sweat for rate monitoring, chromatographic analysis, or active sweat gland location within specified area. Construction of capsule allows change of inserts while device remains strapped in place.

Bird's Nest Filter Causing Symptomatic Hydronephrosis Following Transmural Penetration of the Inferior Vena Cava

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stacey, C.S., E-mail: cheika@doctors.org.uk; Manhire, A.R.; Rose, D.H.

2004-01-15

We report a case of symptomatic hydronephrosis caused by transcaval penetration of a Bird's Nest filter. Perforation of the wall of the inferior vena cava (IVC) following insertion of a caval filter is a well-recognized complication. Whilst two cases of hydronephrosis have been described with Greenfield filters, no case involving a Bird's Nest filter has been reported previously.

Fungal colonization of air filters and insulation in a multi-story office building: production of volatile organics

NASA Technical Reports Server (NTRS)

Ahearn, D. G.; Crow, S. A.; Simmons, R. B.; Price, D. L.; Mishra, S. K.; Pierson, D. L.

1997-01-01

Secondary air filters in the air-handling units on four floors of a multi-story office building with a history of fungal colonization of insulation within the air distribution system were examined for the presence of growing fungi and production of volatile organic compounds. Fungal mycelium and conidia of Cladosporium and Penicillium spp. were observed on insulation from all floors and both sides of the air filters from one floor. Lower concentrations of volatile organics were released from air filter medium colonized with fungi as compared with noncolonized filter medium. However, the volatiles from the colonized filter medium included fungal metabolites such as acetone and a carbonyl sulfide-like compound that were not released from noncolonized filter medium. The growth of fungi in air distribution systems may affect the content of volatile organics in indoor air.

Fungal colonization of air filters and insulation in a multi-story office building: production of volatile organics.

PubMed

Ahearn, D G; Crow, S A; Simmons, R B; Price, D L; Mishra, S K; Pierson, D L

1997-11-01

Secondary air filters in the air-handling units on four floors of a multi-story office building with a history of fungal colonization of insulation within the air distribution system were examined for the presence of growing fungi and production of volatile organic compounds. Fungal mycelium and conidia of Cladosporium and Penicillium spp. were observed on insulation from all floors and both sides of the air filters from one floor. Lower concentrations of volatile organics were released from air filter medium colonized with fungi as compared with noncolonized filter medium. However, the volatiles from the colonized filter medium included fungal metabolites such as acetone and a carbonyl sulfide-like compound that were not released from noncolonized filter medium. The growth of fungi in air distribution systems may affect the content of volatile organics in indoor air.

Rugged fiber optic probe for raman measurement

DOEpatents

O'Rourke, Patrick E.; Toole, Jr., William R.; Nave, Stanley E.

1998-01-01

An optical probe for conducting light scattering analysis is disclosed. The probe comprises a hollow housing and a probe tip. A fiber assembly made up of a transmitting fiber and a receiving bundle is inserted in the tip. A filter assembly is inserted in the housing and connected to the fiber assembly. A signal line from the light source and to the spectrometer also is connected to the filter assembly and communicates with the fiber assembly. By using a spring-loaded assembly to hold the fiber connectors together with the in-line filters, complex and sensitive alignment procedures are avoided. The close proximity of the filter assembly to the probe tip eliminates or minimizes self-scattering generated by the optical fiber. Also, because the probe can contact the sample directly, sensitive optics can be eliminated.

Particulate matter concentrations in residences: an intervention study evaluating stand-alone filters and air conditioners.

PubMed

Batterman, S; Du, L; Mentz, G; Mukherjee, B; Parker, E; Godwin, C; Chin, J-Y; O'Toole, A; Robins, T; Rowe, Z; Lewis, T

2012-06-01

This study, a randomized controlled trial, evaluated the effectiveness of free-standing air filters and window air conditioners (ACs) in 126 low-income households of children with asthma. Households were randomized into a control group, a group receiving a free-standing HEPA filter placed in the child's sleeping area, and a group receiving the filter and a window-mounted AC. Indoor air quality (IAQ) was monitored for week-long periods over three to four seasons. High concentrations of particulate matter (PM) and carbon dioxide were frequently seen. When IAQ was monitored, filters reduced PM levels in the child's bedroom by an average of 50%. Filter use varied greatly among households and declined over time, for example, during weeks when pollutants were monitored, filter use was initially high, averaging 84±27%, but dropped to 63±33% in subsequent seasons. In months when households were not visited, use averaged only 34±30%. Filter effectiveness did not vary in homes with central or room ACs. The study shows that measurements over multiple seasons are needed to characterize air quality and filter performance. The effectiveness of interventions using free-standing air filters depends on occupant behavior, and strategies to ensure filter use should be an integral part of interventions. Environmental tobacco smoke (ETS) increased particulate matter (PM) levels by about 14 μg/m3 and was often detected using ETS-specific tracers despite restrictions on smoking in the house as reported on questionnaires administered to caregivers. PM concentrations depended on season, filter usage, relative humidity, air exchange ratios, number of children, outdoor PM levels, sweeping/dusting, and presence of a central air conditioner (AC). Free-standing air filters can be an effective intervention that provides substantial reductions in PM concentrations if the filters are used. However, filter use was variable across the study population and declined over the study duration, and thus strategies are needed to encourage and maintain use of filters. The variability in filter use suggests that exposure misclassification is a potential problem in intervention studies using filters. The installation of a room AC in the bedroom, intended to limit air exchange ratios, along with an air filter, did not lower PM levels more than the filter alone. © 2011 John Wiley & Sons A/S.

Filter for on-line air monitor unaffected by radon progeny and method of using same

DOEpatents

Phillips, Terrance D.; Edwards, Howard D.

1999-01-01

An apparatus for testing air having contaminants and radon progeny therein. The apparatus includes a sampling box having an inlet for receiving the air and an outlet for discharging the air. The sampling box includes a filter made of a plate of sintered stainless steel. The filter traps the contaminants, yet allows at least a portion of the radon progeny to pass therethrough. A method of testing air having contaminants and radon progeny therein. The method includes providing a testing apparatus that has a sampling box with an inlet for receiving the air and an outlet for discharging the air, and has a sintered stainless steel filter disposed within said sampling box; drawing air from a source into the sampling box using a vacuum pump; passing the air through the filter; monitoring the contaminants trapped by the filter; and providing an alarm when a selected level of contaminants is reached. The filter traps the contaminants, yet allows at least a portion of the radon progeny to pass therethrough.

Fiber ring laser sensor based on Fabry-Perot cavity interferometer for temperature sensing

NASA Astrophysics Data System (ADS)

Zou, Hui; Ma, Lei; Xiong, Hui; Zhang, Yunshan; Li, Yong Tao

2018-01-01

A ring laser temperature sensor based on a novel reflective fiber Fabry-Perot (F-P) interferometer air cavity is proposed and experimentally demonstrated. The reflective F-P air cavity, which consists of a segment of glass capillary inserted between two single-mode fibers, is utilized as a sensing element as well as as a filter in the fiber ring cavity. As temperature increases, the reflection spectra of the F-P sensor move towards the longer wavelength, and then cause lasing wavelength shifts. By monitoring the variation of lasing wavelength, we obtain a temperature sensor system with a high temperature sensitivity of 0.249 nm °C-1, a narrow 3 dB bandwidth of 0.1514 nm, and a high signal-to-noise ratio of 52 dB. Moreover, it is convenient to fabricate the sensor head, and the stability is very good, giving it a wide range of applications.

Impact of the air filtration on indoor particle concentration by using combination filters in offices building

NASA Astrophysics Data System (ADS)

Kabrein, H.; Hariri, A.; Leman, A. M.; Noraini, N. M. R.; Yusof, M. Z. M.; Afandi, A.

2017-09-01

Heating ventilation and air conditioning system (HVAC) is very important for offices building and human health. The combining filter method was used to reduce the air pollution indoor such as that particulate matter and gases pollution that affected in health and productivity. Using particle filters in industrial HVAC systems (factories and manufacturing process) does not enough to remove all the indoor pollution. The main objective of this study is to investigate the impact of combination filters for particle and gases removal efficiency. The combining method is by using two filters (particulate filter pre-filter and carbon filter) to reduce particle matter and gases respectively. The purpose of this study is to use minimum efficiency reporting value (MERV filter) rating 13 and activated carbon filter (ACF) to remove indoor air pollution and controlling the air change rate to enhance the air quality and energy saving. It was concluded that the combination filter showed good removal efficiency of particle up to 90.76% and 89.25% for PM10 and PM2.5 respectively. The pressure drop across the filters was small compared with the high-efficiency filters. The filtration efficiency of combination filters after three months’ was better than efficiency by the new MERV filter alone.

78 FR 46315 - Foreign-Trade Zone (FTZ) 247-Erie, Pennsylvania, Notification of Proposed Production Activity, GE...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-31

...; cover assemblies; strainer assemblies; oil filter assemblies; air filter assemblies; screen assemblies; filter assemblies; breather assemblies; filter box assemblies; sand trap assemblies; valve stems; brake... holders; staples; rivets; brazing alloys; diesel engines; frame assemblies; air inlets; filter box air...

True Measures

ERIC Educational Resources Information Center

Cox, Ron

2010-01-01

Air filters perform an important function in commercial and institutional facilities. Because indoor air typically is two to five times more polluted than outdoor air, air filters are needed to remove respirable particles such as microorganisms, dust and allergens from the breathing air. In fact, air filters provide the primary defense for…

First report of Legionella pneumophila in car cabin air filters. Are these a potential exposure pathway for professional drivers?

PubMed

Alexandropoulou, Ioanna G; Konstantinidis, Theocharis G; Parasidis, Theodoros A; Nikolaidis, Christos; Panopoulou, Maria; Constantinidis, Theodoros C

2013-12-01

Recent findings have identified professional drivers as being at an increased risk of Legionnaires' disease. Our hypothesis was that used car cabin air filters represent a reservoir of Legionella bacteria, and thus a potential pathway for contamination. We analysed used cabin air filters from various types of car. The filters were analysed by culture and by molecular methods. Our findings indicated that almost a third of air filters were colonized with Legionella pneumophila. Here, we present the first finding of Legionella spp. in used car cabin air filters. Further investigations are needed in order to confirm this exposure pathway. The presence of Legionella bacteria in used cabin air filters may have been an unknown source of infection until now.

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

21 CFR 347.52 - Labeling of astringent drug products.

Code of Federal Regulations, 2011 CFR

2011-04-01

... states “[bullet] dissolve 1 to 3 packets in [insert volume] of cool or warm water [bullet] stir until... [bullet] stir until fully dissolved; do not strain or filter. The resulting mixture contains [insert...

14 CFR 23.1107 - Induction system filters.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Induction system filters. 23.1107 Section... § 23.1107 Induction system filters. If an air filter is used to protect the engine against foreign material particles in the induction air supply— (a) Each air filter must be capable of withstanding the...

14 CFR 23.1107 - Induction system filters.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Induction system filters. 23.1107 Section... § 23.1107 Induction system filters. If an air filter is used to protect the engine against foreign material particles in the induction air supply— (a) Each air filter must be capable of withstanding the...

14 CFR 23.1107 - Induction system filters.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction system filters. 23.1107 Section... § 23.1107 Induction system filters. If an air filter is used to protect the engine against foreign material particles in the induction air supply— (a) Each air filter must be capable of withstanding the...

14 CFR 23.1107 - Induction system filters.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Induction system filters. 23.1107 Section... § 23.1107 Induction system filters. If an air filter is used to protect the engine against foreign material particles in the induction air supply— (a) Each air filter must be capable of withstanding the...

14 CFR 23.1107 - Induction system filters.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Induction system filters. 23.1107 Section... § 23.1107 Induction system filters. If an air filter is used to protect the engine against foreign material particles in the induction air supply— (a) Each air filter must be capable of withstanding the...

Protein-Based Nanofabrics for Multifunctional Air Filtering

NASA Astrophysics Data System (ADS)

Souzandeh, Hamid

With the fast development of economics and population, air pollution is getting worse and becomes a great concern worldwide. The release of chemicals, particulates and biological materials into air can lead to various diseases or discomfort to humans and other living organisms, alongside other serious impacts on the environment. Therefore, improving indoor air quality using various air filters is in critical need because people stay inside buildings most time of the day. However, current air filters using traditional polymers can only remove particles from the polluted air and disposing the huge amount of used air filters can cause serious secondary environmental pollution. Therefore, development of multi-functional air filter materials with environmental friendliness is significant. For this purpose, we developed "green" protein-based multifunctional air-filtering materials. The outstanding performance of the green materials in removal of multiple species of pollutants, including particulate matter, toxic chemicals, and biological hazards, simultaneously, will greatly facilitate the development of the next-generation air-filtration systems. First and foremost, we developed high-performance protein-based nanofabric air-filter mats. It was found that the protein-nanofabrics possess high-efficiency multifunctional air-filtering properties for both particles and various species of chemical gases. Then, the high-performance natural protein-based nanofabrics were promoted both mechanically and functionally by a textured cellulose paper towel. It is interestingly discovered that the textured cellulose paper towel not only can act as a flexible mechanical support, but also a type of airflow regulator which can improve the pollutant-nanofilter interactions. Furthermore, the protein-based nanofabrics were crosslinked in order to enhance the environmental-stability of the filters. It was found that the crosslinked protein-nanofabrics can significantly improve the structure stability against different moisture levels and temperatures, while maintain the multifunctional filtration performance. Moreover, it was demonstrated that the crosslinked protein-nanomaterials also possess antibacterial properties against the selected gram-negative and gram-positive bacteria. This provides a cost-effective solution for advanced "green" nanomaterials with excellent performance in both filtration functions and structure stability under varying environment. This work indicates that protein-based air-filters are promising "green" air-filtering materials for next-generation air-filtration systems.

Carbon fiber composite molecular sieve electrically regenerable air filter media

DOEpatents

Wilson, Kirk A.; Burchell, Timothy D.; Judkins, Roddie R.

1998-01-01

An electrically regenerable gas filter system includes a carbon fiber composite molecular sieve (CFCMS) filter medium. After a separate medium-efficiency pre-filter removes particulate from the supply airstream, the CFCMS filter sorbs gaseous air pollutants before the air is recirculated to the space. When saturated, the CFCMS media is regenerated utilizing a low-voltage current that is caused to pass through the filter medium.

Achieving 'excellent' indoor air quality in commercial offices equipped with air-handling unit--respirable suspended particulate.

PubMed

Lam, K S; Chan, F S; Fung, W Y; Lui, B S S; Lau, L W L

2006-04-01

A study was carried out to investigate the feasibility of achieving ultra low respirable suspended particulates (RSP) in commercial offices without major modification of existing ventilation systems by enhancing the particulates removal efficiency of existing central ventilation systems. Four types of filters which include pre-filters, cartridge filters, bag filters and high efficiency particulates air (HEPA) filters were tested in a commercial building in Causeway Bay. The results show that an RSP objective of <20 microg/m3 could be met by removing RSP from both the return air and outdoor air supply simultaneously. This level of performance is classed as 'excellent' by the Hong Kong Government, Environmental Protection Department. Filters with efficiency that exceed 80% placed both in the return air and outdoor air were sufficient to meet the objective. It is not necessary to install HEPA filters to achieve the 'excellent' class. The outdoor air filter has great influence on the steady state indoor RSP concentration while the effective cleaning rate is governed by the return air filter. Higher efficiency filters increased the static drop but the volume flow of the air fan was not affected significantly. The additional cost incurred was <5% of the existing operation cost. This paper reports a field study of RSP control for an indoor office environment. The results are directly applicable to building service engineering in the design of ventilation systems using air-handling units. Field observations indicated that indoor RSP in an office environment could be suppressed below 20 microg/m3 within 1 h by the simultaneous filtration of outdoor air and return air. Outdoor air filtration has a great influence on the steady state indoor concentration and return air filtration governs the cleaning rate. It is believed that the results of this study could be extended to the cleaning of other indoor pollutants such as volatile organic compounds.

Industrial stator vane with sequential impingement cooling inserts

DOEpatents

Jones, Russell B; Fedock, John A; Goebel, Gloria E; Krueger, Judson J; Rawlings, Christopher K; Memmen, Robert L

2013-08-06

A turbine stator vane for an industrial engine, the vane having two impingement cooling inserts that produce a series of impingement cooling from the pressure side to the suction side of the vane walls. Each insert includes a spar with a row of alternating impingement cooling channels and return air channels extending in a radial direction. Impingement cooling plates cover the two sides of the insert and having rows of impingement cooling holes aligned with the impingement cooling channels and return air openings aligned with the return air channel.

78 FR 16604 - Airworthiness Directives; Diamond Aircraft Industries GmbH Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-18

... unsafe condition as the engine air inlet filter is subject to icing. We are issuing this AD to require... warmer air conditions. The subsequent investigation identified that the engine air inlet filter is... with a manually controlled alternate air valve which bypasses the inlet air filter and provides...

Preparation of Fiber Based Binder Materials to Enhance the Gas Adsorption Efficiency of Carbon Air Filter.

PubMed

Lim, Tae Hwan; Choi, Jeong Rak; Lim, Dae Young; Lee, So Hee; Yeo, Sang Young

2015-10-01

Fiber binder adapted carbon air filter is prepared to increase gas adsorption efficiency and environmental stability. The filter prevents harmful gases, as well as particle dusts in the air from entering the body when a human inhales. The basic structure of carbon air filter is composed of spunbond/meltblown/activated carbon/bottom substrate. Activated carbons and meltblown layer are adapted to increase gas adsorption and dust filtration efficiency, respectively. Liquid type adhesive is used in the conventional carbon air filter as a binder material between activated carbons and other layers. However, it is thought that the liquid binder is not an ideal material with respect to its bonding strength and liquid flow behavior that reduce gas adsorption efficiency. To overcome these disadvantages, fiber type binder is introduced in our study. It is confirmed that fiber type binder adapted air filter media show higher strip strength, and their gas adsorption efficiencies are measured over 42% during 60 sec. These values are higher than those of conventional filter. Although the differential pressure of fiber binder adapted air filter is relatively high compared to the conventional one, short fibers have a good potential as a binder materials of activated carbon based air filter.

Resonant Transmission of Air-Coupled Ultrasound Through Metallic Inserts in Honeycomb Sandwich Structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, J.J.; Barnard, D.J.; Hsu, D.K.

2005-04-09

Metallic inserts are embedded into composite honeycomb sandwiches as hard points for mechanical connections. Air-coupled ultrasound can be used for detecting disbonds between the insert and the facesheet. It was discovered in such inspections that a surprisingly large amplitude could be transmitted through thick metallic inserts (e.g. 0.75'' thick and 1.5'' diameter), whereas a thin plate of the same material will transmit a much weaker signal. This paper reports an experimental and analytic study of the geometrical effect of inserts on transmitted UT signals. Modal analyses of cylindrical inserts were made using the finite element code ANSYS. The transmission efficiencymore » or air-coupled ultrasound correlated well with the longitudinal vibration mode of the cylinder.« less

Engineering Filters for Reducing Spontaneous Emission in cQED

NASA Astrophysics Data System (ADS)

Bronn, Nicholas; Masluk, Nicholas; Srinivasan, Srikanth; Chow, Jerry; Abraham, David; Rothwell, Mary; Keefe, George; Gambetta, Jay; Steffen, Matthias; Lirakis, Chris

2014-03-01

Inserting a notch filter between a qubit and the external environment at the qubit frequency can significantly suppress spontaneous emission mediated by the cavity (``Purcell effect''). In order to realize this filtering in multi-qubit architectures, where space comes at a premium, we will present a filter with minimal space requirements. We acknowledge support from IARPA under contract W911NF-10-1-0324.

Filter vapor trap

DOEpatents

Guon, Jerold

1976-04-13

A sintered filter trap is adapted for insertion in a gas stream of sodium vapor to condense and deposit sodium thereon. The filter is heated and operated above the melting temperature of sodium, resulting in a more efficient means to remove sodium particulates from the effluent inert gas emanating from the surface of a liquid sodium pool. Preferably the filter leaves are precoated with a natrophobic coating such as tetracosane.

Natural Air Purifier

NASA Technical Reports Server (NTRS)

1993-01-01

NASA environmental research has led to a plant-based air filtering system. Dr. B.C. Wolverton, a former NASA engineer who developed a biological filtering system for space life support, served as a consultant to Terra Firma Environmental. The company is marketing the BioFilter, a natural air purifier that combines activated carbon and other filter media with living plants and microorganisms. The filter material traps and holds indoor pollutants; plant roots and microorganisms then convert the pollutants into food for the plant. Most non-flowering house plants will work. After pollutants have been removed, the cleansed air is returned to the room through slits in the planter. Terra Firma is currently developing a filter that will also disinfect the air.

Wildfire Smoke

MedlinePlus

... keep the fresh-air intake closed and the filter clean to prevent outdoor smoke from getting inside. ... inside with the windows closed. Use an air filter . Use a freestanding indoor air filter with particle ...

Efficiency of different air filter types for pig facilities at laboratory scale

PubMed Central

Wenke, Cindy; Pospiech, Janina; Reutter, Tobias; Truyen, Uwe

2017-01-01

Air filtration has been shown to be efficient in reducing pathogen burden in circulating air. We determined at laboratory scale the retention efficiency of different air filter types either composed of a prefilter (EU class G4) and a secondary fiberglass filter (EU class F9) or consisting of a filter mat (EU class M6 and F8-9). Four filter prototypes were tested for their capability to remove aerosol containing equine arteritis virus (EAV), porcine reproductive and respiratory syndrome virus (PRRSV), bovine enterovirus 1 (BEV), Actinobacillus pleuropneumoniae (APP), and Staphylococcus (S.) aureus from air. Depending on the filter prototype and utilisation, the airflow was set at 1,800 m3/h (combination of upstream prefilter and fiberglass filter) or 80 m3/h (filter mat). The pathogens were aerosolized and their concentration was determined in front of and behind the filter by culture or quantitative real-time RT-PCR. Furthermore, survival of the pathogens over time in the filter material was determined. Bacteria were most efficiently filtered with a reduction rate of up to 99.9% depending on the filter used. An approximately 98% reduction was achieved for the viruses tested. Viability or infectivity of APP or PRRSV in the filter material decreased below the detection limit after 4 h and 24 h, respectively, whereas S. aureus was still culturable after 4 weeks. Our results demonstrate that pathogens can efficiently be reduced by air filtration. Consequently, air filtration combined with other strict biosecurity measures markedly reduces the risk of introducing airborne transmitted pathogens to animal facilities. In addition, air filtration might be useful in reducing bioaerosols within a pig barn, hence improving respiratory health of pigs. PMID:29028843

Efficiency of different air filter types for pig facilities at laboratory scale.

PubMed

Wenke, Cindy; Pospiech, Janina; Reutter, Tobias; Truyen, Uwe; Speck, Stephanie

2017-01-01

Air filtration has been shown to be efficient in reducing pathogen burden in circulating air. We determined at laboratory scale the retention efficiency of different air filter types either composed of a prefilter (EU class G4) and a secondary fiberglass filter (EU class F9) or consisting of a filter mat (EU class M6 and F8-9). Four filter prototypes were tested for their capability to remove aerosol containing equine arteritis virus (EAV), porcine reproductive and respiratory syndrome virus (PRRSV), bovine enterovirus 1 (BEV), Actinobacillus pleuropneumoniae (APP), and Staphylococcus (S.) aureus from air. Depending on the filter prototype and utilisation, the airflow was set at 1,800 m3/h (combination of upstream prefilter and fiberglass filter) or 80 m3/h (filter mat). The pathogens were aerosolized and their concentration was determined in front of and behind the filter by culture or quantitative real-time RT-PCR. Furthermore, survival of the pathogens over time in the filter material was determined. Bacteria were most efficiently filtered with a reduction rate of up to 99.9% depending on the filter used. An approximately 98% reduction was achieved for the viruses tested. Viability or infectivity of APP or PRRSV in the filter material decreased below the detection limit after 4 h and 24 h, respectively, whereas S. aureus was still culturable after 4 weeks. Our results demonstrate that pathogens can efficiently be reduced by air filtration. Consequently, air filtration combined with other strict biosecurity measures markedly reduces the risk of introducing airborne transmitted pathogens to animal facilities. In addition, air filtration might be useful in reducing bioaerosols within a pig barn, hence improving respiratory health of pigs.

Concentric Split Flow Filter

NASA Technical Reports Server (NTRS)

Stapleton, Thomas J. (Inventor)

2015-01-01

A concentric split flow filter may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, filter may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow filter may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of filter media and substantially the other half of the air flow to be treated traveling through the second bed of filter media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of filter may be reduced by as much as a factor of 4 as compare to the conventional design.

Allergy-Proof Your House

MedlinePlus

... small-particle or high-efficiency particulate air (HEPA) filter. Shampoo the carpet frequently. Curtains and blinds. Use ... dander they shed. Air filtration. Choose an air filter that has a small-particle or HEPA filter. ...

Design and analysis of a high Q MEMS passive RF filter

NASA Astrophysics Data System (ADS)

Rathee, Vishal; Pande, Rajesh

2016-04-01

Over the past few years, significant growth has been observed in using MEMS based passive components in the RF microelectronics domain, especially in transceiver system. This is due to some excellent properties of the MEMS devices like low loss, low cost and excellent isolation. This paper presents a design of high performance MEMS passive band pass filter, consisting of L and C with improved quality factor and insertion loss less than the reported filters. In this paper we have presented a design of 2nd order band pass filter with 2.4GHz centre frequency and 83MHz bandwidth for Bluetooth application. The simulation results showed improved Q-factor of 34 and Insertion loss of 1.7dB to 1.9dB. The simulation results needs to be validated by fabricating the device, fabrication flow of which is also presented in the paper.

Particulate matter concentrations in residences: an intervention study evaluating stand-alone filters and air conditioners

PubMed Central

Batterman, S.; Du, L.; Mentz, G.; Mukherjee, B.; Parker, E.; Godwin, C.; Chin, J.-Y.; O'Toole, A.; Robins, T.; Rowe, Z.; Lewis, T.

2014-01-01

This study, a randomized controlled trial, evaluated the effectiveness of free-standing air filters and window air conditioners (ACs) in 126 low-income households of children with asthma. Households were randomized into a control group, a group receiving a free-standing HEPA filter placed in the child's sleeping area, and a group receiving the filter and a window-mounted AC. Indoor air quality (IAQ) was monitored for week-long periods over three to four seasons. High concentrations of particulate matter (PM) and carbon dioxide were frequently seen. When IAQ was monitored, filters reduced PM levels in the child's bedroom by an average of 50%. Filter use varied greatly among households and declined over time, for example, during weeks when pollutants were monitored, filter use was initially high, averaging 84 ± 27%, but dropped to 63 ± 33% in subsequent seasons. In months when households were not visited, use averaged only 34 ± 30%. Filter effectiveness did not vary in homes with central or room ACs. The study shows that measurements over multiple seasons are needed to characterize air quality and filter performance. The effectiveness of interventions using free-standing air filters depends on occupant behavior, and strategies to ensure filter use should be an integral part of interventions. PMID:22145709

Improving indoor air quality and thermal comfort in office building by using combination filters

NASA Astrophysics Data System (ADS)

Kabrein, H.; Yusof, M. Z. M.; Hariri, A.; Leman, A. M.; Afandi, A.

2017-09-01

Poor indoor air quality and thermal comfort condition in the workspace affected the occupants’ health and work productivity, especially when adapting the recirculation of air in heating ventilation and air-conditioning (HVAC) system. The recirculation of air was implemented in this study by mixing the circulated returned indoor air with the outdoor fresh air. The aims of this study are to assess the indoor thermal comfort and indoor air quality (IAQ) in the office buildings, equipped with combination filters. The air filtration technique consisting minimum efficiency reporting value (MERV) filter and activated carbon fiber (ACF) filter, located before the fan coil units. The findings of the study show that the technique of mixing recirculation air with the fresh air through the combination filters met the recommended thermal comfort condition in the workspace. Furthermore, the result of the post-occupancy evaluation (POE) and the environmental measurements comply with the ASHRAE 55 standard. In addition, the level of CO2 concentration continued to decrease during the period of the measurement.

Experimental investigation of air pressure affecting filtration performance of fibrous filter sheet.

PubMed

Xu, Bin; Yu, Xiao; Wu, Ya; Lin, Zhongping

2017-03-01

Understanding the effect of air pressure on their filtration performance is important for assessing the effectiveness of fibrous filters under different practical circumstances. The effectiveness of three classes of air filter sheets were investigated in laboratory-based measurements at a wide range of air pressures (60-130 KPa). The filtration efficiency was found most sensitive to the air pressure change at smaller particle sizes. As the air pressure increased from 60 to 130 KPa, significant decrease in filtration efficiency (up to 15%) and increase in pressure drop (up to 90 Pa) were observed. The filtration efficiency of the filter sheet with largest fiber diameter and smallest solid volume fraction was affected most, while the pressure drop of the filter sheet with smallest fiber diameter and largest solid volume fraction was affected most. The effect of air pressure on the filtration efficiency was slightly larger at greater filter face air velocity. However, the effect of air pressure on the pressure drop was negligible. The filtration efficiency and pressure drop were explicitly expressed as functions of the air pressure. Two coefficients were empirically derived and successfully accounted for the effects of air pressure on filtration efficiency and pressure drop.

Fungal colonization of air filters for use in heating, ventilating, and air conditioning (HVAC) systems.

PubMed

Simmons, R B; Crow, S A

1995-01-01

New and used cellulosic air filters for HVAC systems including those treated with antimicrobials were suspended in vessels with a range of relative humidities (55-99%) and containing non-sterile potting soil which stimulates fungal growth. Most filters yielded fungi prior to suspension in the chambers but only two of 14 nontreated filters demonstrated fungal colonization following use in HVAC systems. Filters treated with antimicrobials, particularly a phosphated amine complex, demonstrated markedly less fungal colonization than nontreated filters. In comparison with nontreated cellulosic filters, fungal colonization of antimicrobial-treated cellulosic filters was selective and delayed.

Use of Whatman-41 filters in air quality sampling networks (with applications to elemental analysis)

NASA Technical Reports Server (NTRS)

Neustadter, H. E.; Sidik, S. M.; King, R. B.; Fordyce, J. S.; Burr, J. C.

1974-01-01

The operation of a 16-site parallel high volume air sampling network with glass fiber filters on one unit and Whatman-41 filters on the other is reported. The network data and data from several other experiments indicate that (1) Sampler-to-sampler and filter-to-filter variabilities are small; (2) hygroscopic affinity of Whatman-41 filters need not introduce errors; and (3) suspended particulate samples from glass fiber filters averaged slightly, but not statistically significantly, higher than from Whatman-41-filters. The results obtained demonstrate the practicability of Whatman-41 filters for air quality monitoring and elemental analysis.

Optical Filter Assembly for Interplanetary Optical Communications

NASA Technical Reports Server (NTRS)

Chen, Yijiang; Hemmati, Hamid

2013-01-01

Ground-based, narrow-band, high throughput optical filters are required for optical links from deep space. We report on the development of a tunable filter assembly that operates at telecommunication window of 1550 nanometers. Low insertion loss of 0.5 decibels and bandwidth of 90 picometers over a 2000 nanometers operational range of detectors has been achieved.

Air filtration in the free molecular flow regime: a review of high-efficiency particulate air filters based on carbon nanotubes.

PubMed

Li, Peng; Wang, Chunya; Zhang, Yingying; Wei, Fei

2014-11-01

Air filtration in the free molecular flow (FMF) regime is important and challenging because a higher filtration efficiency and lower pressure drop are obtained when the fiber diameter is smaller than the gas mean free path in the FMF regime. In previous studies, FMF conditions have been obtained by increasing the gas mean free path through reducing the pressure and increasing the temperature. In the case of carbon nanotubes (CNTs) with nanoscale diameters, it is possible to filtrate in the FMF regime under normal conditions. This paper reviews recent progress in theoretical and experimental studies of air filtration in the FMF regime. Typical structure models of high-efficiency particulate (HEPA) air filters based on CNTs are introduced. The pressure drop in air filters operated in the FMF regime is less than that predicted by the conventional air filtration theory. The thinnest HEPA filters fabricated from single-walled CNT films have an extremely low pressure drop. CNT air filters with a gradient nanostructure are shown to give a much better filtration performance in dynamic filtration. CNT air filters with a hierarchical structure and an agglomerated CNT fluidized bed air filter are also introduced. Finally, the challenges and opportunities for the application of CNTs in air filtration are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Retrievable Inferior Vena Cava Filters for Venous Thromboembolism

PubMed Central

Win, Lei Lei

2013-01-01

Inferior vena cava (IVC) filters are used as an alternative to anticoagulants for prevention of fatal pulmonary embolism (PE) in venous thromboembolic disorders. Retrievable IVC filters have become an increasingly attractive option due to the long-term risks of permanent filter placement. These devices are shown to be technically feasible in insertion and retrieval percutaneously while providing protection from PE. Nevertheless, there are complications and failed retrievals with these retrievable filters. The aim of the paper is to review the retrievable filters and their efficacy, safety, and retrievability. PMID:24967292

A Novel Technique for Inferior Vena Cava Filter Extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnston, Edward William, E-mail: ed.johnston@doctors.org.uk; Rowe, Luke Michael Morgan; Brookes, Jocelyn

Inferior vena cava (IVC) filters are used to protect against pulmonary embolism in high-risk patients. Whilst the insertion of retrievable IVC filters is gaining popularity, a proportion of such devices cannot be removed using standard techniques. We describe a novel approach for IVC filter removal that involves snaring the filter superiorly along with the use of flexible forceps or laser devices to dissect the filter struts from the caval wall. This technique has used to successfully treat three patients without complications in whom standard techniques failed.

The Optional VenaTech{sup Trade-Mark-Sign} Convertible{sup Trade-Mark-Sign} Vena Cava Filter: Experimental Study in Sheep

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le Blanche, Alain F., E-mail: le_blanche.alain@chu-amiens.fr; Ricco, Jean-Baptiste; Bonneau, Michel

Purpose: Retrieval of optional caval filters may be impaired by filter tilting, migration, fracture, or embedding in the IVC wall. The goal of this experimental study was to evaluate a new optional filter, convertible by unlocking and removing the filter head. Methods: Forty-nine Pre-Alp sheep (average weight, 55 kg) were anesthetized. IVC was catheterized via the right femoral vein (n = 46) or via the internal jugular vein (n = 3) with a 12.9-F sheath. VenaTech{sup Trade-Mark-Sign} Convertible{sup Trade-Mark-Sign} IVC filters were inserted as either permanent filters (n = 14) or as filters to be converted. Conversion was immediately aftermore » deployment (n = 19) or delayed after 1, 3, or 6 months (n = 20). Filter delivery, deployment, and conversion with measurement of migration and tilting were evaluated by cavography. Incorporation of the filter's stabilizers and arms in the IVC wall was assessed by gross anatomy. Results: Delivery system insertion, filter release, and immediate conversion were successful in all cases. Delayed conversion was completed in all but one sheep, due to insufficient snare tension. Complimentary balloon-catheter inflation was required in 12 of 20 delayed conversions to achieve filter opening. In all 49 sheep, no thrombosis, migration, or significant tilting occurred. Within 4 weeks of conversion, the filter's stabilizers and arms were incorporated into the IVC wall. Upon removal, the filter head was free of intimal growth. Conclusions: The VenaTech{sup Trade-Mark-Sign} Convertible{sup Trade-Mark-Sign} optional IVC filter was successfully implanted in all sheep with no migration or tilting. Conversion at various dates by filter head removal was feasible in all but one case.« less

Efficiency of automotive cabin air filters to reduce acute health effects of diesel exhaust in human subjects

PubMed Central

Rudell, B.; Wass, U.; Horstedt, P.; Levin, J. O.; Lindahl, R.; Rannug, U.; Sunesson, A. L.; Ostberg, Y.; Sandstrom, T.

1999-01-01

OBJECTIVES: To evaluate the efficiency of different automotive cabin air filters to prevent penetration of components of diesel exhaust and thereby reduce biomedical effects in human subjects. Filtered air and unfiltered diluted diesel exhaust (DDE) were used as negative and positive controls, respectively, and were compared with exposure to DDE filtered with four different filter systems. METHODS: 32 Healthy non- smoking subjects (age 21-53) participated in the study. Each subject was exposed six times for 1 hour in a specially designed exposure chamber: once to air, once to unfiltered DDE, and once to DDE filtered with the four different cabin air filters. Particle concentrations during exposure to unfiltered DDE were kept at 300 micrograms/m3. Two of the filters were particle filters. The other two were particle filters combined with active charcoal filters that might reduce certain gaseous components. Subjective symptoms were recorded and nasal airway lavage (NAL), acoustic rhinometry, and lung function measurements were performed. RESULTS: The two particle filters decreased the concentrations of diesel exhaust particles by about half, but did not reduce the intensity of symptoms induced by exhaust. The combination of active charcoal filters and a particle filter significantly reduced the symptoms and discomfort caused by the diesel exhaust. The most noticable differences in efficacy between the filters were found in the reduction of detection of an unpleasant smell from the diesel exhaust. In this respect even the two charcoal filter combinations differed significantly. The efficacy to reduce symptoms may depend on the abilities of the filters investigated to reduce certain hydrocarbons. No acute effects on NAL, rhinometry, and lung function variables were found. CONCLUSIONS: This study has shown that the use of active charcoal filters, and a particle filter, clearly reduced the intensity of symptoms induced by diesel exhaust. Complementary studies on vehicle cabin air filters may result in further diminishing the biomedical effects of diesel exhaust in subjects exposed in traffic and workplaces.   PMID:10450238

Incident-response monitoring technologies for aircraft cabin air quality

NASA Astrophysics Data System (ADS)

Magoha, Paul W.

Poor air quality in commercial aircraft cabins can be caused by volatile organophosphorus (OP) compounds emitted from the jet engine bleed air system during smoke/fume incidents. Tri-cresyl phosphate (TCP), a common anti-wear additive in turbine engine oils, is an important component in today's global aircraft operations. However, exposure to TCP increases risks of certain adverse health effects. This research analyzed used aircraft cabin air filters for jet engine oil contaminants and designed a jet engine bleed air simulator (BAS) to replicate smoke/fume incidents caused by pyrolysis of jet engine oil. Field emission scanning electron microscopy (FESEM) with X-ray energy dispersive spectroscopy (EDS) and neutron activation analysis (NAA) were used for elemental analysis of filters, and gas chromatography interfaced with mass spectrometry (GC/MS) was used to analyze used filters to determine TCP isomers. The filter analysis study involved 110 used and 90 incident filters. Clean air filter samples exposed to different bleed air conditions simulating cabin air contamination incidents were also analyzed by FESEM/EDS, NAA, and GC/MS. Experiments were conducted on a BAS at various bleed air conditions typical of an operating jet engine so that the effects of temperature and pressure variations on jet engine oil aerosol formation could be determined. The GC/MS analysis of both used and incident filters characterized tri- m-cresyl phosphate (TmCP) and tri-p-cresyl phosphate (TpCP) by a base peak of an m/z = 368, with corresponding retention times of 21.9 and 23.4 minutes. The hydrocarbons in jet oil were characterized in the filters by a base peak pattern of an m/z = 85, 113. Using retention times and hydrocarbon thermal conductivity peak (TCP) pattern obtained from jet engine oil standards, five out of 110 used filters tested had oil markers. Meanwhile 22 out of 77 incident filters tested positive for oil fingerprints. Probit analysis of jet engine oil aerosols obtained from BAS tests by optical particle counter (OPC) revealed lognormal distributions with the mean (range) of geometric mass mean diameter (GMMD) = 0.41 (0.39, 0.45) microm and geometric standard deviation (GSD), sigma g = 1.92 (1.87, 1.98). FESEM/EDS and NAA techniques found a wide range of elements on filters, and further investigations of used filters are recommended using these techniques. The protocols for air and filter sampling and GC/MS analysis used in this study will increase the options available for detecting jet engine oil on cabin air filters. Such criteria could support policy development for compliance with cabin air quality standards during incidents.

Dynamic Radioactive Source for Evaluating and Demonstrating Time-dependent Performance of Continuous Air Monitors.

PubMed

McLean, Thomas D; Moore, Murray E; Justus, Alan L; Hudston, Jonathan A; Barbé, Benoît

2016-11-01

Evaluation of continuous air monitors in the presence of a plutonium aerosol is time intensive, expensive, and requires a specialized facility. The Radiation Protection Services Group at Los Alamos National Laboratory has designed a Dynamic Radioactive Source, intended to replace plutonium aerosol challenge testing. The Dynamic Radioactive Source is small enough to be inserted into the sampler filter chamber of a typical continuous air monitor. Time-dependent radioactivity is introduced from electroplated sources for real-time testing of a continuous air monitor where a mechanical wristwatch motor rotates a mask above an alpha-emitting electroplated disk source. The mask is attached to the watch's minute hand, and as it rotates, more of the underlying source is revealed. The measured alpha activity increases with time, simulating the arrival of airborne radioactive particulates at the air sampler inlet. The Dynamic Radioactive Source allows the temporal behavior of puff and chronic release conditions to be mimicked without the need for radioactive aerosols. The new system is configurable to different continuous air monitor designs and provides an in-house testing capability (benchtop compatible). It is a repeatable and reusable system and does not contaminate the tested air monitor. Test benefits include direct user control, realistic (plutonium) aerosol spectra, and iterative development of continuous air monitor alarm algorithms. Data obtained using the Dynamic Radioactive Source has been used to elucidate alarm algorithms and to compare the response time of two commercial continuous air monitors.

Dynamic Radioactive Source for Evaluating and Demonstrating Time-dependent Performance of Continuous Air Monitors

DOE PAGES

McLean, Thomas D.; Moore, Murray E.; Justus, Alan L.; ...

2016-01-01

Evaluation of continuous air monitors in the presence of a plutonium aerosol is time intensive, expensive, and requires a specialized facility. The Radiation Protection Services Group at Los Alamos National Laboratory has designed a Dynamic Radioactive Source, intended to replace plutonium aerosol challenge testing. Furthermore, the Dynamic Radioactive Source is small enough to be inserted into the sampler filter chamber of a typical continuous air monitor. Time-dependent radioactivity is introduced from electroplated sources for real-time testing of a continuous air monitor where a mechanical wristwatch motor rotates a mask above an alpha-emitting electroplated disk source. The mask is attached tomore » the watch’s minute hand, and as it rotates, more of the underlying source is revealed. The alpha activity we measured increases with time, simulating the arrival of airborne radioactive particulates at the air sampler inlet. The Dynamic Radioactive Source allows the temporal behavior of puff and chronic release conditions to be mimicked without the need for radioactive aerosols. The new system is configurable to different continuous air monitor designs and provides an in-house testing capability (benchtop compatible). It is a repeatable and reusable system and does not contaminate the tested air monitor. Test benefits include direct user control, realistic (plutonium) aerosol spectra, and iterative development of continuous air monitor alarm algorithms. We also used data obtained using the Dynamic Radioactive Source to elucidate alarm algorithms and to compare the response time of two commercial continuous air monitors.« less

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

Code of Federal Regulations, 2013 CFR

2013-10-01

... inhalation pressure to draw the ambient air through the air-purifying filter elements (filters) to remove... classified into three series, N-, R-, and P-series. The N-series filters are restricted to use in those workplaces free of oil aerosols. The R- and P-series filters are intended for removal of any particulate that...

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

Code of Federal Regulations, 2011 CFR

2011-10-01

... inhalation pressure to draw the ambient air through the air-purifying filter elements (filters) to remove... classified into three series, N-, R-, and P-series. The N-series filters are restricted to use in those workplaces free of oil aerosols. The R- and P-series filters are intended for removal of any particulate that...

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

Code of Federal Regulations, 2014 CFR

2014-10-01

... inhalation pressure to draw the ambient air through the air-purifying filter elements (filters) to remove... classified into three series, N-, R-, and P-series. The N-series filters are restricted to use in those workplaces free of oil aerosols. The R- and P-series filters are intended for removal of any particulate that...

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

Code of Federal Regulations, 2012 CFR

2012-10-01

... inhalation pressure to draw the ambient air through the air-purifying filter elements (filters) to remove... classified into three series, N-, R-, and P-series. The N-series filters are restricted to use in those workplaces free of oil aerosols. The R- and P-series filters are intended for removal of any particulate that...

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

Code of Federal Regulations, 2010 CFR

2010-10-01

... inhalation pressure to draw the ambient air through the air-purifying filter elements (filters) to remove... classified into three series, N-, R-, and P-series. The N-series filters are restricted to use in those workplaces free of oil aerosols. The R- and P-series filters are intended for removal of any particulate that...

Evaluation of a commercial air filter for removal of viruses from the air.

PubMed

Roelants, P; Boon, B; Lhoest, W

1968-10-01

The effectiveness of a commercial absolute air filter for removal of viruses from air was tested with an actinophage, under the usual conditions of a laminar airflow clean room. A new method of dry phage dispersion is described. The filter showed an average reduction of 99.996% of airborne actinophage.

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2011 CFR

2011-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2013 CFR

2013-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2012 CFR

2012-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2014 CFR

2014-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

Progress on applications of high temperature superconducting microwave filters

NASA Astrophysics Data System (ADS)

Chunguang, Li; Xu, Wang; Jia, Wang; Liang, Sun; Yusheng, He

2017-07-01

In the past two decades, various kinds of high performance high temperature superconducting (HTS) filters have been constructed and the HTS filters and their front-end subsystems have been successfully applied in many fields. The HTS filters with small insertion loss, narrow bandwidth, flat in-band group delay, deep out-of-band rejection, and steep skirt slope are reviewed. Novel HTS filter design technologies, including those in high power handling filters, multiband filters and frequency tunable filters, are reviewed, as well as the all-HTS integrated front-end receivers. The successful applications to various civilian fields, such as mobile communication, radar, deep space detection, and satellite technology, are also reviewed.

Inferior Vena Cava Filters: Guidelines, Best Practice, and Expanding Indications

PubMed Central

DeYoung, Elliot; Minocha, Jeet

2016-01-01

Vena caval interruption, currently accomplished by percutaneous image-guided insertion of an inferior vena cava (IVC) filter, is an important therapeutic option in the management of selected patients with venous thromboembolism. The availability of optional (or retrievable) filters, in particular, has altered the practice patterns for IVC filters, with a shift to these devices and expansion of indications for filter placement. As new devices have become available and clinicians have become more familiar and comfortable with IVC filters, the indications for filter placement have continued to evolve and expand. This article reviews current guidelines and expanding indications for IVC filter placement. PMID:27247472

Development and testing of a portable wind sensitive directional air sampler

NASA Technical Reports Server (NTRS)

Deyo, J.; Toma, J.; King, R. B.

1975-01-01

A portable wind sensitive directional air sampler was developed as part of an air pollution source identification system. The system is designed to identify sources of air pollution based on the directional collection of field air samples and their analysis for TSP and trace element characteristics. Sources can be identified by analyzing the data on the basis of pattern recognition concepts. The unit, designated Air Scout, receives wind direction signals from an associated wind vane. Air samples are collected on filter slides using a standard high volume air sampler drawing air through a porting arrangement which tracks the wind direction and permits collection of discrete samples. A preset timer controls the length of time each filter is in the sampling position. At the conclusion of the sampling period a new filter is automatically moved into sampling position displacing the previous filter to a storage compartment. Thus the Air Scout may be set up at a field location, loaded with up to 12 filter slides, and left to acquire air samples automatically, according to the wind, at any timer interval desired from 1 to 30 hours.

Reduction of timing jitter and intensity noise in normal-dispersion passively mode-locked fiber lasers by narrow band-pass filtering.

PubMed

Qin, Peng; Song, Youjian; Kim, Hyoji; Shin, Junho; Kwon, Dohyeon; Hu, Minglie; Wang, Chingyue; Kim, Jungwon

2014-11-17

Fiber lasers mode-locked with normal cavity dispersion have recently attracted great attention due to large output pulse energy and femtosecond pulse duration. Here we accurately characterized the timing jitter of normal-dispersion fiber lasers using a balanced cross-correlation method. The timing jitter characterization experiments show that the timing jitter of normal-dispersion mode-locked fiber lasers can be significantly reduced by using narrow band-pass filtering (e.g., 7-nm bandwidth filtering in this work). We further identify that the timing jitter of the fiber laser is confined in a limited range, which is almost independent of cavity dispersion map due to the amplifier-similariton formation by insertion of the narrow bandpass filter. The lowest observed timing jitter reaches 0.57 fs (rms) integrated from 10 kHz to 10 MHz Fourier frequency. The rms relative intensity noise (RIN) is also reduced from 0.37% to 0.02% (integrated from 1 kHz to 5 MHz Fourier frequency) by the insertion of narrow band-pass filter.

Magnetic analyses of powders from exhausted cabin air filters

NASA Astrophysics Data System (ADS)

Winkler, Aldo; Sagnotti, Leonardo

2013-04-01

The automotive cabin air filter is a pleated-paper filter placed in the outside-air intake for the car's passenger compartment. Dirty and saturated cabin air filters significantly reduce the airflow from the outside and introduce particulate matter (PM) and allergens (for example, pollen) into the cabin air stream. Magnetic measurements and analyses have been carried out on powders extracted from exhausted cabin air filters to characterize their magnetic properties and to compare them to those already reported for powders collected from disk brakes, gasoline exhaust pipes and Quercus ilex leaves. This study is also aimed at the identification and quantification of the contribution of the ultrafine fraction, superparamagnetic (SP) at room temperature, to the overall magnetic properties of these powders. This contribution was estimated by interpreting and comparing data from FORCs, isothermal remanent magnetization vs time decay curves, frequency and field dependence of the magnetic susceptibility and out-of-phase susceptibility. The magnetic properties and the distribution of the SP particles are generally homogenous and independent of the brand of the car, of the model of the filter and of its level of usage. The relatively high concentration of magnetic PM trapped in these filters poses relevant questions about the air quality inside a car.

Detection of respiratory viruses on air filters from aircraft.

PubMed

Korves, T M; Johnson, D; Jones, B W; Watson, J; Wolk, D M; Hwang, G M

2011-09-01

To evaluate the feasibility of identifying viruses from aircraft cabin air, we evaluated whether respiratory viruses trapped by commercial aircraft air filters can be extracted and detected using a multiplex PCR, bead-based assay. The ResPlex II assay was first tested for its ability to detect inactivated viruses applied to new filter material; all 18 applications of virus at a high concentration were detected. The ResPlex II assay was then used to test for 18 respiratory viruses on 48 used air filter samples from commercial aircraft. Three samples tested positive for viruses, and three viruses were detected: rhinovirus, influenza A and influenza B. For 33 of 48 samples, internal PCR controls performed suboptimally, suggesting sample matrix effect. In some cases, influenza and rhinovirus RNA can be detected on aircraft air filters, even more than 10 days after the filters were removed from aircraft. With protocol modifications to overcome PCR inhibition, air filter sampling and the ResPlex II assay could be used to characterize viruses in aircraft cabin air. Information about viruses in aircraft could support public health measures to reduce disease transmission within aircraft and between cities. © The MITRE corporation. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

Exposure to cyclic anhydrides in welding: a new allergen-chlorendic anhydride.

PubMed

Pfäffli, Pirkko; Hämeilä, Mervi; Keskinen, Helena; Wirmoila, Ritva

2002-11-01

Respiratory effects associated with welding fumes have been manifested in welders as occupational asthma. Previous studies have concerned mainly the effects of metal fume exposure, although it has also been suggested that asthma may develop as a result of exposure to contaminants generated from painted metals. To determine whether welding fumes contain irritating and sensitizing anhydrides, air samples were collected during the repair welding of forest harvesters, which were painted with chlorinated polyester paint. Samples were collected with an assembly of a spiral glass trap inserted between a filter holder with a Teflon filter and a Tenax sampling tube. Sample analyses were with GC-MS and GC-ECD. Sensitizing anhydrides released from the paint into the air were primarily chlorendic anhydride (<2-44 microg/m(3)) and phthalic anhydride (11-21 microg/m(3)). Hydrogen chloride (HCl) and hexachlorocyclopentadiene were also found. Airborne HCl was measured with Dräger tubes. Since paint films are electrical insulators, the film around the welding seam was removed before arc welding. Removal of paint with an abrasive wheel caused the least exposure to HCl (<0.5 ppm) in contrast to burning with a gas fuel torch, (HCl approximately 5 ppm). HCl exposure was the highest (<0.5-20 ppm) during welding. It is recommended that dry paint coating be removed from an area around the seam with an abrasive wheel, not by burning, before welding.

Evaluation of a Commercial Air Filter for Removal of Virus from the Air

PubMed Central

Roelants, P.; Boon, B.; Lhoest, W.

1968-01-01

The effectiveness of a commercial absolute air filter for removal of viruses from air was tested with an actinophage, under the usual conditions of a laminar airflow clean room. A new method of dry phage dispersion is described. The filter showed an average reduction of 99.996% of airborne actinophage. PMID:5684200

Hemodialysis dialyzers contribute to contamination of air microemboli that bypass the alarm system in the air trap.

PubMed

Stegmayr, C; Jonsson, P; Forsberg, U; Stegmayr, B

2008-04-01

Previous studies have shown that micrometer-sized air bubbles are introduced into the patient during hemodialysis. The aim of this study was to investigate, in vitro, the influence of dialysis filters on the generation of air bubbles. Three different kind of dialyzers were tested: one high-flux FX80 dry filter (Fresenius Medical Care AG&Co. KGaA, Bad Homburg, Germany), one low-flux F8HPS dry filter (Fresenius Medical Care AG&Co. KGaA, Bad Homburg, Germany) and a wet-stored APS-18u filter (Asahi Kasei Medical, Tokyo, Japan). The F8HPS was tested with pump flow ranging between 100 to 400 ml/min. The three filters were compared using a constant pump flow of 300 ml/min. Measurements were performed using an ultrasound Doppler instrument. In 90% of the series, bubbles were measured after the outlet line of the air trap without triggering an alarm. There were significantly more bubbles downstream than upstream of the filters F8HPS and FX80, while there was a significant reduction using the APS-18u. There was no reduction in the number of bubbles after passage through the air trap versus before the air trap (after the dialyzer). Increased priming volume reduced the extent of bubbles in the system. Data indicate that the air trap does not prevent air microemboli from entering the venous outlet part of the dialysis tubing (entry to the patient). More extended priming of the dialysis circuit may reduce the extent of microemboli that originate from dialysis filters. A wet filter may be favorable instead of dry-steam sterilized filters.

Personal continuous air monitor

DOEpatents

Morgan, Ronald G.; Salazar, Samuel A.

2000-01-01

A personal continuous air monitor capable of giving immediate warning of the presence of radioactivity has a filter/detector head to be worn in the breathing zone of a user, containing a filter mounted adjacent to radiation detectors, and a preamplifier. The filter/detector head is connected to a belt pack to be worn at the waist or on the back of a user. The belt pack contains a signal processor, batteries, a multichannel analyzer, a logic circuit, and an alarm. An air pump also is provided in the belt pack for pulling air through the filter/detector head by way of an air tube.

Receptacle for Optical-Fiber Scraps

NASA Technical Reports Server (NTRS)

Nevin, R.

1986-01-01

Small pieces of glass trapped by moving air. Device traps fibers in section of black air-conditioner filter material. Filter section rests on metal screen above axial fan, which pulls air down through filter. Fan is small, quiet unit of type ordinarily used to cool electronic equipment.

Fibrous Filter to Protect Building Environments from Polluting Agents: A Review

NASA Astrophysics Data System (ADS)

Chavhan, Md. Vaseem; Mukhopadhyay, Arunangshu

2016-04-01

This paper discusses the use of fibrous filter to protect the building environments from air born polluting agents and especially of concern chemical, biological and radiological agents. Air-filtration includes removal of particulate from air and toxic gases from air. In air filtration, particulate which are mostly biological and radioactive types of agents can be removed by using mechanical and electrostatic filters. Some biological agents, which cannot be removed by air filtration alone, special techniques like antimicrobial finish, UV germicides, coated filters etc. are required. Biocide agent can be added into the fibre itself by grafting reaction to impart antimicrobial activity. Chemical agents like toxic gases can be removed by integrating adsorbents and sorbents in filters or by fibre modifications. It is also possible to impart catalytic conversion properties into the fibre to remove volatile gasous. Radioactive agents can be removed by particulate filter if present in the form of aerosol or by gas cleaning by the use of specific fibre impregnate.

Predicting inferior vena cava (IVC) filter retrievability using positional parameters: A comparative study of various filter types.

PubMed

Gotra, A; Doucet, C; Delli Fraine, P; Bessissow, A; Dey, C; Gallix, B; Boucher, L-M; Valenti, D

2018-05-14

To compare changes in inferior vena cava (IVC) filter positional parameters from insertion to removal and examine how they affect retrievability amongst various filter types. A total of 447 patients (260 men, 187 women) with a mean age of 55 years (range: 13-91 years) who underwent IVC filter retrieval between 2007-2014 were retrospectively included. Post-insertion and pre-retrieval angiographic studies were assessed for filter tilt, migration, strut wall penetration and retrieval outcomes. ANCOVA and multiple logistic regression models were used to analyze factors affecting retrieval success. Pairwise comparisons between filter types were performed. Of 488 IVC filter retrieval attempts, 94.1% were ultimately successful. The ALN filter had the highest mean absolute value of tilt (5.6 degrees), the Optease filter demonstrated the largest mean migration (-8.0mm) and the Bard G2 filter showed highest mean penetration (5.2mm). Dwell time of 0-90 days (OR, 11.1; P=0.01) or 90-180 days (OR, 2.6; P=0.02), net tilt of 10-15 degrees (OR 8.9; P=0.05), caudal migration of -10 to 0mm (OR, 3.46; P=0.03) and penetration less than 3mm (OR, 2.6; P=0.01) were positive predictors of successful retrievability. Higher odds of successful retrieval were obtained for the Bard G2X, Bard G2 and Cook Celect when compared to the ALN and Cordis Optease filters. Shorter dwell time, lower mean tilt, caudal migration and less caval wall penetration are positive predictors of successful IVC filter retrieval. Copyright © 2018 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Isokinetic air sampler

DOEpatents

Sehmel, George A.

1979-01-01

An isokinetic air sampler includes a filter, a holder for the filter, an air pump for drawing air through the filter at a fixed, predetermined rate, an inlet assembly for the sampler having an inlet opening therein of a size such that isokinetic air sampling is obtained at a particular wind speed, a closure for the inlet opening and means for simultaneously opening the closure and turning on the air pump when the wind speed is such that isokinetic air sampling is obtained. A system incorporating a plurality of such samplers provided with air pumps set to draw air through the filter at the same fixed, predetermined rate and having different inlet opening sizes for use at different wind speeds is included within the ambit of the present invention as is a method of sampling air to measure airborne concentrations of particulate pollutants as a function of wind speed.

Miniaturized LTCC elliptic-function lowpass filters with side stopbands

DOE PAGES

Hsieh, Lung -Hwa; Dai, Steve Xunhu

2015-05-28

A compact, high-selectivity, and wide stopband lowpass filter is highly demanded in wireless communication systems to suppress adjacent harmonics and unwanted signals. In this letter, a new miniaturized lowpass filter with elliptic-function frequency response is introduced. The filter is fabricated in multilayer low temperature cofired ceramics. The size of the miniaturized filter is 5.5 × 3.9 × 1.72 mm3. As a result, the measured insertion loss of the filter is better than 0.37 dB from DC to 1.28 GHz and the measured stopband of the filter is great than 22 dB from 2.3 to 7.5 GHz.

HEPA air filter (image)

MedlinePlus

... pet dander and other irritating allergens from the air. Along with other methods to reduce allergens, such ... controlling the amount of allergens circulating in the air. HEPA filters can be found in most air ...

Effect of post-filter anticoagulation on mortality in patients with cancer-associated pulmonary embolism.

PubMed

Kang, Jieun; Kim, Seon Ok; Oh, Yeon-Mok; Lee, Sang-Do; Lee, Jae Seung

2018-05-17

Malignancy is associated with an increased risk of venous thromboembolism. Inferior vena cava filters are a viable alternative when anticoagulation is infeasible because of the risk of bleeding. Although the current guidelines recommend that all patients with a vena cava filter be treated with anticoagulation treatment when the risk of bleeding is reduced, studies concerning the role of concomitant anticoagulation after vena cava filter insertion in high-risk patients are scarce. Since many cancer patients suffer from a high risk of hemorrhagic complications, we aimed to determine the effect of post-filter anticoagulation on mortality in patients with a malignant solid tumor. A retrospective cohort study of patients with pulmonary embolism was performed between January 2010 and May 2016. Patients with a solid tumor and vena cava filter inserted because of pulmonary embolism were included. Using Cox proportional hazards model, the prognostic effect of clinical variables was analyzed. A total of 180 patients were analyzed, with 143 patients receiving and 37 patients not receiving post-filter anticoagulation treatment. Mortality was not significantly different between the two groups. The presence of metastatic cancer and that of pancreatobiliary cancer were significant risk factors for mortality. However, post-filter anticoagulation did not show significant effect on mortality regardless of the stage of cancer. In patients with cancer-associated pulmonary embolism, the effect of post-filter anticoagulation on mortality may not be critical, especially in patients with a short life expectancy.

Methodology for modeling the microbial contamination of air filters.

PubMed

Joe, Yun Haeng; Yoon, Ki Young; Hwang, Jungho

2014-01-01

In this paper, we propose a theoretical model to simulate microbial growth on contaminated air filters and entrainment of bioaerosols from the filters to an indoor environment. Air filter filtration and antimicrobial efficiencies, and effects of dust particles on these efficiencies, were evaluated. The number of bioaerosols downstream of the filter could be characterized according to three phases: initial, transitional, and stationary. In the initial phase, the number was determined by filtration efficiency, the concentration of dust particles entering the filter, and the flow rate. During the transitional phase, the number of bioaerosols gradually increased up to the stationary phase, at which point no further increase was observed. The antimicrobial efficiency and flow rate were the dominant parameters affecting the number of bioaerosols downstream of the filter in the transitional and stationary phase, respectively. It was found that the nutrient fraction of dust particles entering the filter caused a significant change in the number of bioaerosols in both the transitional and stationary phases. The proposed model would be a solution for predicting the air filter life cycle in terms of microbiological activity by simulating the microbial contamination of the filter.

29 CFR 1910.134 - Respiratory protection.

Code of Federal Regulations, 2012 CFR

2012-07-01

... impact and penetration. High efficiency particulate air (HEPA) filter means a filter that is at least 99... as a high efficiency particulate air (HEPA) filter, or an air-purifying respirator equipped with a... frequency of respirator use (including use for rescue and escape); (C) The expected physical work effort; (D...

29 CFR 1910.134 - Respiratory protection.

Code of Federal Regulations, 2014 CFR

2014-07-01

... impact and penetration. High efficiency particulate air (HEPA) filter means a filter that is at least 99... as a high efficiency particulate air (HEPA) filter, or an air-purifying respirator equipped with a... frequency of respirator use (including use for rescue and escape); (C) The expected physical work effort; (D...

29 CFR 1910.134 - Respiratory protection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... impact and penetration. High efficiency particulate air (HEPA) filter means a filter that is at least 99... as a high efficiency particulate air (HEPA) filter, or an air-purifying respirator equipped with a... frequency of respirator use (including use for rescue and escape); (C) The expected physical work effort; (D...

Effect of Intake Air Filter Condition on Light-Duty Gasoline Vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, John F; Huff, Shean P; West, Brian H

2012-01-01

Proper maintenance can help vehicles perform as designed, positively affecting fuel economy, emissions, and the overall drivability. This effort investigates the effect of one maintenance factor, intake air filter replacement, with primary focus on vehicle fuel economy, but also examining emissions and performance. Older studies, dealing with carbureted gasoline vehicles, have indicated that replacing a clogged or dirty air filter can improve vehicle fuel economy and conversely that a dirty air filter can be significantly detrimental to fuel economy. The effect of clogged air filters on the fuel economy, acceleration and emissions of five gasoline fueled vehicles is examined. Fourmore » of these were modern vehicles, featuring closed-loop control and ranging in model year from 2003 to 2007. Three vehicles were powered by naturally aspirated, port fuel injection (PFI) engines of differing size and cylinder configuration: an inline 4, a V6 and a V8. A turbocharged inline 4-cylinder gasoline direct injection (GDI) engine powered vehicle was the fourth modern gasoline vehicle tested. A vintage 1972 vehicle equipped with a carburetor (open-loop control) was also examined. Results reveal insignificant fuel economy and emissions sensitivity of modern vehicles to air filter condition, but measureable effects on the 1972 vehicle. All vehicles experienced a measured acceleration performance penalty with clogged intake air filters.« less

40 CFR 94.211 - Emission-related maintenance instructions for purchasers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... filter change, fuel filter change, air filter change, cooling system maintenance, adjustment of idle... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES... at 1,500-hour intervals thereafter. (i) Exhaust gas recirculation system-related filters and coolers...

COMPUTATIONS ON THE PERFORMANCE OF PARTICLE FILTERS AND ELECTRONIC AIR CLEANERS

EPA Science Inventory

The paper discusses computations on the performance of particle filters and electronic air cleaners (EACs). The collection efficiency of particle filters and ACs is calculable if certain factors can be assumed or calibrated. For fibrous particulate filters, measurement of colle...

YBCO High-Temperature Superconducting Filters on M-Plane Sapphire Substrates

NASA Technical Reports Server (NTRS)

Sabataitis, J. C.; Mueller, C. H.; Miranda, F. A.; Warner, J.; Bhasin, K. B.

1996-01-01

Since the discovery of High Temperature Superconductors (HTS) in 1986, microwave circuits have been demonstrated using HTS films on various substrates. These HTS-based circuits have proven to operate with less power loss than their metallic film counterparts at 77 K. This translates into smaller and lighter microwave circuits for space communication systems such as multiplexer filter banks. High quality HTS films have conventionally been deposited on lanthanum aluminate (LaAlO3) substrates. However, LaAlO3 has a relative dielectric constant (epsilon(sub r)) of 24. With a epsilon(sub r) approx. 9.4-11.6, sapphire (Al2O3) would be a preferable substrate for the fabrication of HTS-based components since the lower dielectric constant would permit wider microstrip lines to be used in filter design, since the lower dielectric constant would permit wider microstrip lines to be used for a given characteristic impedance (Z(sub 0)), thus lowering the insertion losses and increasing the power handling capabilities of the devices. We report on the fabrication and characterization of YBa2Cu3O(7-delta) (YBCO) on M-plane sapphire bandpass filters at 4.0 GHz. For a YBCO 'hairpin' filter, a minimum insertion loss of 0.5 dB was measured at 77 K as compared with 1.4 dB for its gold counterpart. In an 'edge-coupled' configuration, the insertion loss went down from 0.9 dB for the gold film to 0.8 dB for the YBCO film at the same temperature.

Case of a Misplaced IVC Filter: A Lesson to Learn

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Sanjay, E-mail: drssharma@hotmail.com; Mukund, Amar, E-mail: dramarmukund@gmail.co; Agarwal, Sandeep, E-mail: sandeep_aiims@yahoo.co.i

2010-08-15

The inferior vena cava (IVC) filter insertion is a well established procedure to prevent significant pulmonary embolism in selected situations. It is generally considered straight forward without significant complications. We report an interesting case of a young postpartum woman in whom an IVC filter was misplaced in the right gonadal vein. This complication is only rarely reported. Presence of prominent right gonadal vein must always be kept in mind during trans-jugular placement of infra renal filter in the IVC in post partum women.

Wideband bandpass filters employing broadside-coupled microstrip lines for MIC and MMIC applications

NASA Technical Reports Server (NTRS)

Tran, M.; Nguyen, C.

1994-01-01

Wideband bandpass filters employing half-wavelength broadside-coupled microstrip lines suitable for microwave and mm-wave integrated monolithic integrated circuits (MIC and MMIC) are presented. Several filters have been developed at X-band (8 to 12 GHz) with 1 dB insertion loss. Fair agreement between the measured and calculated results has been observed. The analysis of the broadside-coupled microstrip lines used in the filters, based on the quasi-static spectral domain technique, is also described.

Electrically heated particulate filter embedded heater design

DOEpatents

Gonze, Eugene V.; Chapman, Mark R.

2014-07-01

An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine and wherein an upstream surface of the particulate filter includes machined grooves. A grid of electrically resistive material is inserted into the machined grooves of the exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF.

Chemical Protection Testing of Sorbent-Based Air Purification Components (APCs)

DTIC Science & Technology

2016-06-24

APC’s ability to filter air in a chemically contaminated environment. 15. SUBJECT TERMS Air purification component; APC; filtration fabric...FF, filter media, collective protection; individual protection. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18...incoming air. The intent of this process is to produce traceable, quantifiable, and defensible data that can be used to analyze an APC’s ability to filter

Problems in creation of modern air inlet filters of power gas turbine plants in Russia and methods of their solving

NASA Astrophysics Data System (ADS)

Mikhaylov, V. E.; Khomenok, L. A.; Sherapov, V. V.

2016-08-01

The main problems in creation and operation of modern air inlet paths of gas turbine plants installed as part of combined-cycle plants in Russia are presented. It is noted that design features of air inlet filters shall be formed at the stage of the technical assignment not only considering the requirements of gas turbine plant manufacturer but also climatic conditions, local atmospheric air dustiness, and a number of other factors. The recommendations on completing of filtration system for air inlet filter of power gas turbine plants depending on the facility location are given, specific defects in design and experience in operation of imported air inlet paths are analyzed, and influence of cycle air preparation quality for gas turbine plant on value of operating expenses and cost of repair works is noted. Air treatment equipment of various manufacturers, influence of aerodynamic characteristics on operation of air inlet filters, features of filtration system operation, anti-icing system, weather canopies, and other elements of air inlet paths are considered. It is shown that nonuniformity of air flow velocity fields in clean air chamber has a negative effect on capacity and aerodynamic resistance of air inlet filter. Besides, the necessity in installation of a sufficient number of differential pressure transmitters allowing controlling state of each treatment stage not being limited to one measurement of total differential pressure in the filtration system is noted in the article. According to the results of the analysis trends and methods for modernization of available equipment for air inlet path, the importance of creation and implementation of new technologies for manufacturing of filtering elements on sites of Russia within the limits of import substitution are given, and measures on reliability improvement and energy efficiency for air inlet filter are considered.

Antimicrobial nanoparticle-coated electrostatic air filter with high filtration efficiency and low pressure drop.

PubMed

Sim, Kyoung Mi; Park, Hyun-Seol; Bae, Gwi-Nam; Jung, Jae Hee

2015-11-15

In this study, we demonstrated an antimicrobial nanoparticle-coated electrostatic (ES) air filter. Antimicrobial natural-product Sophora flavescens nanoparticles were produced using an aerosol process, and were continuously deposited onto the surface of air filter media. For the electrostatic activation of the filter medium, a corona discharge electrification system was used before and after antimicrobial treatment of the filter. In the antimicrobial treatment process, the deposition efficiency of S. flavescens nanoparticles on the ES filter was ~12% higher than that on the pristine (Non-ES) filter. In the evaluation of filtration performance using test particles (a nanosized KCl aerosol and submicron-sized Staphylococcus epidermidis bioaerosol), the ES filter showed better filtration efficiency than the Non-ES filter. However, antimicrobial treatment with S. flavescens nanoparticles affected the filtration efficiency of the filter differently depending on the size of the test particles. While the filtration efficiency of the KCl nanoparticles was reduced on the ES filter after the antimicrobial treatment, the filtration efficiency was improved after the recharging process. In summary, we prepared an antimicrobial ES air filter with >99% antimicrobial activity, ~92.5% filtration efficiency (for a 300-nm KCl aerosol), and a ~0.8 mmAq pressure drop (at 13 cm/s). This study provides valuable information for the development of a hybrid air purification system that can serve various functions and be used in an indoor environment. Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 89.109 - Maintenance instructions and minimum allowable maintenance intervals.

Code of Federal Regulations, 2011 CFR

2011-07-01

... change, oil filter change, fuel filter change, air filter change, cooling system maintenance, adjustment... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION...) Exhaust gas recirculation system-related filters and coolers. (ii) Positive crankcase ventilation valve...

40 CFR 89.109 - Maintenance instructions and minimum allowable maintenance intervals.

Code of Federal Regulations, 2010 CFR

2010-07-01

... change, oil filter change, fuel filter change, air filter change, cooling system maintenance, adjustment... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION...) Exhaust gas recirculation system-related filters and coolers. (ii) Positive crankcase ventilation valve...

Define and Quantify the Physics of Air Flow, Pressure Drop and Aerosol Collection in Nuclear Grade HEPA Filters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, Murray E.

Objective: Develop a set of peer-review and verified analytical methods to adjust HEPA filter performance to different flow rates, temperatures and altitudes. Experimental testing will measure HEPA filter flow rate, pressure drop and efficiency to verify the analytical approach. Nuclear facilities utilize HEPA (High Efficiency Particulate Air) filters to purify air flow for workspace ventilation. However, the ASME AG-1 technical standard (Code on Nuclear Air and Gas Treatment) does not adequately describe air flow measurement units for HEPA filter systems. Specifically, the AG-1 standard does not differentiate between volumetric air flow in ACFM (actual cubic feet per minute)compared to massmore » flow measured in SCFM (standard cubic feet per minute). More importantly, the AG-1 standard has an overall deficiency for using HEPA filter devices at different air flow rates, temperatures, and altitudes. Technical Approach: The collection efficiency and pressure drops of 18 different HEPA filters will be measured over a range of flow rates, temperatures and altitudes. The experimental results will be compared to analytical scoping calculations. Three manufacturers have allocated six HEPA filters each for this effort. The 18 filters will be tested at two different flow rates, two different temperatures and two different altitudes. The 36 total tests will be conducted at two different facilities: the ATI Test facilities (Baltimore MD) and the Los Alamos National Laboratory (Los Alamos NM). The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally designed to evaluate small air samplers. In 2010, modifications were started to convert the wind tunnel for HEPA filter testing. (Extensive changes were necessary for the required aerosol generators, HEPA test fixtures, temperature control devices and measurement capabilities.) To this date, none of these modification activities have been funded through a specific DOE or NNSA program. This is expected to require six months of time, after receipt of funding. Benefits: US DOE facilities that use HEPA filters will benefit from access to the new operational measurement methods. Uncertainty and guesswork will be removed from HEPA filter operations.« less

Bypassing Races in Live Applications with Execution Filters

DTIC Science & Technology

2010-01-01

LOOM creates the needed locks and semaphores on demand. The first time a lock or semaphore is refer- enced by one of the inserted synchronization ...runtime. LOOM provides a flexible and safe language for develop- ers to write execution filters that explicitly synchronize code. It then uses an...first compile their application with LOOM. At runtime, to workaround a race, an application developer writes an execution filter that synchronizes the

Chronic Pain Syndrome Caused by a Bird's Nest Filter: First Case Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Basheer, Mamoun Ahmad, E-mail: drbasheer30@yahoo.co; Hamilton, Mark; Holdaway, Chris

2008-07-15

AimTo report the first case of a Bird's Nest IVC filter causing a chronic pain syndrome lasting 13 years through IVC wall penetration and subsequent break off of one of the filter struts.Materials and ResultsA 43-year-old female presented with a 13-year history of abdominal pain following uneventful insertion of a Bird's Nest vena cava filter through a right internal jugular percutanous approach. A year following the procedure, CT scan revealed one arm of the filter to be outside IVC borders. Nine years from the date of insertion the nature of the pain changed acutely following a five feet jump tomore » more localized RUQ pain worse with twisting movements. A CT scan showed the strut to have pierced the IVC wall and penetrated the Unicate process of pancreas. Plain x-rays taken at different times in February 2006 showed one of the struts to be free floating in the peritoneal cavity. The floating strut was removed surgically from the wall of the Ileum. Postoperative recovery was uneventful and the patient was discharged pain free three days later.ConclusionChronic pain is an added complication of BNF devices. Although rare, it further emphasizes the need for long-term follow up of patients with IVC filters.« less

77 FR 60887 - Airworthiness Directives; Alpha Aviation Concept Limited Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-05

... possible installation of non-conforming air filter elements that are not fitted with metallic mesh and... finding a non conforming air filter fitted to an overseas aircraft during maintenance. Investigation revealed that air filters with P/N 57.34.00.010 supplied by CEAPR between June 2009 and April 2012 may not...

77 FR 44511 - Airworthiness Directives; Alpha Aviation Concept Limited Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-30

... possible installation of non-conforming air filter elements that are not fitted with metallic mesh and... conforming air filter fitted to an overseas aircraft during maintenance. Investigation revealed that air filters with P/N 57.34.00.010 supplied by CEAPR between June 2009 and April 2012 may not have the metallic...

40 CFR 721.10411 - Alkanenitrile, bis(cyanoalkyl)amino (generic) (P-07-537).

Code of Federal Regulations, 2012 CFR

2012-07-01

... with N100 (if oil aerosols absent), R100, or P100 filters; NIOSH-certified powered air-purifying respirator equipped with a loose- fitting hood or helmet and high efficiency particulate air (HEPA) filters... HEPA filters; or NIOSH-certified supplied-air respirator operated in pressure demand or continuous flow...

40 CFR 721.10411 - Alkanenitrile, bis(cyanoalkyl)amino (generic) (P-07-537).

Code of Federal Regulations, 2013 CFR

2013-07-01

... with N100 (if oil aerosols absent), R100, or P100 filters; NIOSH-certified powered air-purifying respirator equipped with a loose- fitting hood or helmet and high efficiency particulate air (HEPA) filters... HEPA filters; or NIOSH-certified supplied-air respirator operated in pressure demand or continuous flow...

40 CFR 721.10411 - Alkanenitrile, bis(cyanoalkyl)amino (generic) (P-07-537).

Code of Federal Regulations, 2014 CFR

2014-07-01

... with N100 (if oil aerosols absent), R100, or P100 filters; NIOSH-certified powered air-purifying respirator equipped with a loose- fitting hood or helmet and high efficiency particulate air (HEPA) filters... HEPA filters; or NIOSH-certified supplied-air respirator operated in pressure demand or continuous flow...

Gamma inert sterilization: a solution to polyethylene oxidation?

PubMed

Medel, Francisco J; Kurtz, Steven M; Hozack, William J; Parvizi, Javad; Purtill, James J; Sharkey, Peter F; MacDonald, Daniel; Kraay, Matthew J; Goldberg, Victor; Rimnac, Clare M

2009-04-01

In the 1990s, oxidation was found to occur in ultra-high molecular weight polyethylene total joint replacement components following gamma irradiation and prolonged shelf aging in air. Orthopaedic manufacturers developed barrier packaging to reduce oxidation during and after radiation sterilization. The present study explores the hypothesis that polyethylene components sterilized in a low-oxygen environment undergo similar in vivo oxidative mechanisms as inserts sterilized in air. In addition, the potential influence of the different sterilization processes on the wear performance of the polyethylene components was examined. An analysis of oxidation, wear, and surface damage was performed for forty-eight acetabular liners and 123 tibial inserts. The mean implantation time was 12.3+/-3.7 years for thirty-one acetabular liners that had been gamma sterilized in air and 4.0+/-2.5 years for the seventeen acetabular liners that had been gamma sterilized in inert gas. The mean implantation time was 11.0+/-3.2 years for the twenty-six tibial inserts that had been sterilized in air and 2.8+/-2.2 years for the ninety-seven tibial inserts that had been gamma sterilized in inert gas. Oxidation and hydroperoxide levels were characterized in loaded and unloaded regions of the inserts. Measurable oxidation and oxidation potential were observed in all cohorts. The oxidation and hydroperoxide levels were regional. Surfaces with access to body fluids were more heavily oxidized than protected bearing surfaces were. This variation appeared to be greater in historical (gamma-in-air-sterilized) components. Regarding wear performance, historical and conventional acetabular liners showed similar wear penetration rates, whereas a low incidence of delamination was confirmed for the conventional tibial inserts in the first decade of implantation. The present study explores the impact of industry-wide changes in sterilization practices for polyethylene. We found lower oxidation and oxidation potential in the conventional acetabular liners and tibial inserts that had been gamma sterilized in inert gas as compared with the historical components that had been gamma sterilized in air. However, we also found strong evidence that conventional components undergo mechanisms of in vivo oxidation similar to those observed following gamma irradiation in air. In addition, gamma sterilization in inert gas did not provide polyethylene with a significant improvement in terms of wear resistance as compared with gamma sterilization in air, except for a lower incidence of delamination in the first decade of implantation for tibial inserts.

Gross Alpha Beta Radioactivity in Air Filters Measured by Ultra Low Level α/β Counter

NASA Astrophysics Data System (ADS)

Cfarku, Florinda; Bylyku, Elida; Deda, Antoneta; Dhoqina, Polikron; Bakiu, Erjona; Perpunja, Flamur

2010-01-01

Study of radioactivity in air as very important for life is done regularly using different methods in every country. As a result of nuclear reactors, atomic centrals, institutions and laboratories, which use the radioactivity substances in open or closed sources, there are a lot radioactive wastes. Mixing of these wastes after treatment with rivers and lakes waters makes very important control of radioactivity. At the other side nuclear and radiological accidents are another source of the contamination of air and water. Due to their radio toxicity, especially those of Sr90, Pu239, etc. a contamination hazard for human begins exist even at low concentration levels. Measurements of radioactivity in air have been performed in many parts of the world mostly for assessment of the doses and risk resulting from consuming air. In this study we present the results of international comparison organized by IAEA Vienna, Austria for the air filters spiked with unknown Alpha and Beta Activity. For the calibration of system we used the same filters spiked: a) with Pu-239 as alpha source; b) Sr-90 as beta source and also the blank filter. The measurements of air filter samples after calibration of the system are done with Ultra Low Level α/β Counter (MPC 9604) Protean Instrument Corporation. The high sensitivity of the system for the determination of the Gross Alpha and Beta activity makes sure detection of low values activity of air filters. Our laboratory results are: Aα = (0.19±0.01) Bq/filter and Aα (IAEA) = (0.17±0.009) Bq/filter; Aβ = (0.33±0.009) Bq/filter and Aβ (IAEA) = (0.29±0.01) Bq/filter. As it seems our results are in good agreement with reference values given by IAEA (International Atomic Energy Agency).

78 FR 5773 - Notification of Proposed Production Activity, Generac Power Systems, Inc., Subzone 41J...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-28

... assemblies; oil/fuel filters; air/oil separation equipment; air filters/elements; catalytic converters... assemblies; AC line filters; dielectric items of paper/plastic; capacitors; circuit breakers; switching...

Mold Occurring on the Air Cleaner High-Efficiency Particulate Air Filters Used in the Houses of Child Patients with Atopic Dermatitis

PubMed Central

Kim, Seong Hwan; Ahn, Geum Ran; Son, Seung Yeol; Bae, Gwi-Nam

2014-01-01

Fungi are the known sources of irritation associated with atopic diseases (e.g., asthma, allergic rhinoconjunctivitis, and atopic eczema). To quantitatively estimate their presence in the indoor environment of atopic dermatitis-inflicted child patient's houses (ADCPHs), the high-efficiency particulate air (HEPA) filters installed inside the air cleaners of three different ADCPHs were investigated for the presence of mold. The air cleaner HEPA filters obtained from the three different ADCPHs were coded as HEPA-A, -B, and -C, respectively, and tested for the presence of mold. The colony forming units (CFUs) corresponding to the HEPA-A, -B, and -C filters were estimated to be 6.51 × 102 ± 1.50 × 102 CFU/cm2, 8.72 × 102 ± 1.69 × 102 CFU/cm2, and 9.71 × 102 ± 1.35 × 102 CFU/cm2, respectively. Aspergillus, Penicillium, Alternaria, Cladosporium, Trichoderma, and other fungal groups were detected in the 2,494 isolates. The distribution of these fungal groups differed among the three filters. Cladosporium was the major fungal group in filters HEPA-A and -C, whereas Penicillium was the major fungal group in the filter HEPA-B. Nine fungal species, including some of the known allergenic species, were identified in these isolates. Cladosporium cladosporioides was the most common mold among all the three filters. This is the first report on the presence of fungi in the air cleaner HEPA filters from ADCPHs in Korea. PMID:25346608

Radon detection

DOEpatents

MacArthur, D.W.; Allander, K.S.; Bounds, J.A.

1994-01-25

A detector for atmospheric radon using a long range alpha detector as its sensing element is described. An electrostatic filter removes ions from ambient air, while allowing radon atoms to pass into a decay cavity. Here, radon atoms are allowed to decay, creating air ions. These air ions are drawn by a fan through a second electrostatic filter which can be activated or deactivated, and into the long range alpha detector. With the second electrostatic filter activated, no air ions are allowed to pass, and the signal output from the long range alpha detector consists of only the electronic background. With the second electrostatic filter deactivated, air ions and cosmic rays will be detected. The cosmic ray contribution can be minimized by shielding. 3 figures.

Radon detection

DOEpatents

MacArthur, Duncan W.; Allander, Krag S.; Bounds, John A.

1994-01-01

A detector for atmospheric radon using a long range alpha detector as its sensing element. An electrostatic filter removes ions from ambient air, while allowing radon atoms to pass into a decay cavity. Here, radon atoms are allowed to decay, creating air ions. These air ions are drawn by a fan through a second electrostatic filter which can be activated or deactivated, and into the long range alpha detector. With the second electrostatic filter activated, no air ions are allowed to pass, and the signal output from the long range alpha detector consists of only the electronic background. With the second electrostatic filter deactivated, air ions and cosmic rays will be detected. The cosmic ray contribution can be minimized by shielding.

Gunther Tulip Retrievable Inferior Vena Caval Filters: Indications, Efficacy, Retrieval, and Complications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Looby, S.; Given, M.F.; Geoghegan, T.

Purpose. We evaluated the Gunther Tulip (GT) retrievable inferior vena cava (IVC) filter with regard to indications, filtration efficacy, complications, retrieval window, and use of anticoagulation. Method. A retrospective study was performed of 147 patients (64 men, 83 women; mean age 58.8 years) who underwent retrievable GT filter insertion between 2001 and 2005. The indications for placement included a diagnosis of pulmonary embolism or deep venous thrombosis with a contraindication to anticoagulation (n = 68), pulmonary embolism or deep venous thrombosis while on anticoagulation (n = 49), prophylactic filter placement for high-risk surgical patients with a past history of pulmonarymore » embolism or deep venous thrombosis (n = 20), and a high risk of pulmonary embolism or deep venous thrombosis (n = 10). Forty-nine of the 147 patients did not receive anticoagulation (33.7%) while 96 of 147 patients did, 82 of these receiving warfarin (56.5%), 11 receiving low-molecular weight heparins (7.58%), and 3 receiving antiplatelet agents alone (2.06%). Results. Filter placement was successful in 147 patients (100%). Two patients had two filters inserted. Of the 147 patients, filter deployment was on a permanent basis in 102 and with an intention to retrieve in 45 patients. There were 36 (80%) successful retrievals and 9 (20%) failed retrievals. The mean time to retrieval was 33.6 days. The reasons for failed retrieval included filter struts tightly adherent to the IVC wall (5/9), extreme filter tilt (2/9), and extensive filter thrombus (2/9). Complications included pneumothorax (n = 4), failure of filter expansion (n = 1), and breakthrough pulmonary embolism (n = 1). No IVC thrombotic episodes were recorded. Discussion. The Gunther Tulip retrievable filter can be used as a permanent or a retrievable filter. It is safe and efficacious. GT filters can be safely retrieved at a mean time interval of 33.6 days. The newly developed Celect filter may extend the retrieval interval.« less

System and Apparatus for Filtering Particles

NASA Technical Reports Server (NTRS)

Agui, Juan H. (Inventor); Vijayakumar, Rajagopal (Inventor)

2015-01-01

A modular pre-filtration apparatus may be beneficial to extend the life of a filter. The apparatus may include an impactor that can collect a first set of particles in the air, and a scroll filter that can collect a second set of particles in the air. A filter may follow the pre-filtration apparatus, thus causing the life of the filter to be increased.

Aircraft Recirculation Filter for Air-Quality and Incident Assessment

PubMed Central

Eckels, Steven J.; Jones, Byron; Mann, Garrett; Mohan, Krishnan R.; Weisel, Clifford P.

2015-01-01

The current research examines the possibility of using recirculation filters from aircraft to document the nature of air-quality incidents on aircraft. These filters are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the filter was chosen as the initial focus. A two-step study was undertaken. First, a compressor/bleed air simulator was developed to simulate an engine oil leak, and samples were analyzed with gas chromatograph-mass spectrometry. These samples provided a concrete link between tricresyl phosphates and a homologous series of synthetic pentaerythritol esters from oil and contaminants found on the sample paper. The second step was to test 184 used aircraft filters with the same gas chromatograph-mass spectrometry system; of that total, 107 were standard filters, and 77 were nonstandard. Four of the standard filters had both markers for oil, with the homologous series synthetic pentaerythritol esters being the less common marker. It was also found that 90% of the filters had some detectable level of tricresyl phosphates. Of the 77 nonstandard filters, 30 had both markers for oil, a significantly higher percent than the standard filters. PMID:25641977

Aircraft Recirculation Filter for Air-Quality and Incident Assessment.

PubMed

Eckels, Steven J; Jones, Byron; Mann, Garrett; Mohan, Krishnan R; Weisel, Clifford P

The current research examines the possibility of using recirculation filters from aircraft to document the nature of air-quality incidents on aircraft. These filters are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the filter was chosen as the initial focus. A two-step study was undertaken. First, a compressor/bleed air simulator was developed to simulate an engine oil leak, and samples were analyzed with gas chromatograph-mass spectrometry. These samples provided a concrete link between tricresyl phosphates and a homologous series of synthetic pentaerythritol esters from oil and contaminants found on the sample paper. The second step was to test 184 used aircraft filters with the same gas chromatograph-mass spectrometry system; of that total, 107 were standard filters, and 77 were nonstandard. Four of the standard filters had both markers for oil, with the homologous series synthetic pentaerythritol esters being the less common marker. It was also found that 90% of the filters had some detectable level of tricresyl phosphates. Of the 77 nonstandard filters, 30 had both markers for oil, a significantly higher percent than the standard filters.

Methodology for Modeling the Microbial Contamination of Air Filters

PubMed Central

Joe, Yun Haeng; Yoon, Ki Young; Hwang, Jungho

2014-01-01

In this paper, we propose a theoretical model to simulate microbial growth on contaminated air filters and entrainment of bioaerosols from the filters to an indoor environment. Air filter filtration and antimicrobial efficiencies, and effects of dust particles on these efficiencies, were evaluated. The number of bioaerosols downstream of the filter could be characterized according to three phases: initial, transitional, and stationary. In the initial phase, the number was determined by filtration efficiency, the concentration of dust particles entering the filter, and the flow rate. During the transitional phase, the number of bioaerosols gradually increased up to the stationary phase, at which point no further increase was observed. The antimicrobial efficiency and flow rate were the dominant parameters affecting the number of bioaerosols downstream of the filter in the transitional and stationary phase, respectively. It was found that the nutrient fraction of dust particles entering the filter caused a significant change in the number of bioaerosols in both the transitional and stationary phases. The proposed model would be a solution for predicting the air filter life cycle in terms of microbiological activity by simulating the microbial contamination of the filter. PMID:24523908

British Society of Interventional Radiology (BSIR) Inferior Vena Cava (IVC) Filter Registry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uberoi, Raman, E-mail: raman.Uberoi@orh.nhs.uk; Tapping, Charles Ross; Chalmers, Nicholas

Purpose: The British Society of Interventional Radiology (BSIR) Inferior Vena Cava (IVC) Filter Registry was produced to provide an audit of current United Kingdom (UK) practice regarding placement and retrieval of IVC filters to address concerns regarding their safety. Methods: The IVC filter registry is a web-based registry, launched by the BSIR on behalf of its membership in October 2007. This report is based on prospectively collected data from October 2007 to March 2011. This report contains analysis of data on 1,434 IVC filter placements and 400 attempted retrievals performed at 68 UK centers. Data collected included patient demographics, insertionmore » and retrieval data, and patient follow-up. Results: IVC filter use in the majority of patients in the UK follows accepted CIRSE guidelines. Filter placement is usually a low-risk procedure, with a low major complication rate (<0.5 %). Cook Gunther Tulip (560 filters: 39 %) and Celect (359 filters: 25 %) filters constituted the majority of IVC filters inserted, with Bard G2, Recovery filters, Cordis Trapease, and OptEase constituting most of the remainder (445 filters: 31 %). More than 96 % of IVC filters deployed as intended. Operator inexperience (<25 procedure) was significantly associated with complications (p < 0.001). Of the IVC filters initially intended for temporary placement, retrieval was attempted in 78 %. Of these retrieval was technically successful in 83 %. Successful retrieval was significantly reduced for implants left in situ for >9 weeks versus those with a shorter dwell time. New lower limb deep vein thrombosis (DVT) and/or IVC thrombosis was reported in 88 patients following filter placement, there was no significant difference of incidence between filter types. Conclusions: This registry report provides interventional radiologists and clinicians with an improved understanding of the technical aspects of IVC filter placement to help improve practice, and the potential consequences of IVC filter placement so that we are better able to advise patients. There is a significant learning curve associated with IVC filter insertion, and when a filter is placed with the intention of removal, procedures should be in place to avoid the patient being lost to follow-up.« less

75 FR 62874 - Keystone Steel and Wire Company; Grant of a Permanent Variance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-13

... the crane-motor cleaning operation by inserting the nozzle of the compressed-air gun into an opening... inserting the nozzle of the compressed-air gun into an opening in the housing, then triggers the compressed...

Switchable multiwavelength thulium-doped fiber ring lasers

NASA Astrophysics Data System (ADS)

Zhao, Shui; Lu, Ping; Liu, Deming; Zhang, Jiangshan

2013-08-01

Two kinds of thulium-doped fiber ring lasers based on a spatial mode beating filter and comb filtering effect are presented and experimentally demonstrated, which all show multiwavelength laser spectrum around 2 μm. In the implementation of the first type of experiment configuration by the use of a piece of multimode fiber (MMF) as a spatial mode beating filter, dual-,triple-, and quadruple-wavelengths appeared whose extinction noise ratio is 25 dB by adjusting the angle of polarization controller. Different wavelength spaces are obtained by inserting different lengths of MMF. The second type is achieved by inserting a Sagnac loop mirror, which was constructed by a 3-dB coupler and a piece of polarization maintaining fiber. Seven stable wavelengths with channel spacing of 0.65 nm and an extinction ratio of 35 dB was achieved. These systems are simple and easy to construct, which can be useful for 2 μm wavelength-division-multiplexed applications.

Simultaneous removal of formaldehyde and benzene in indoor air with a combination of sorption- and decomposition-type air filters.

PubMed

Sekine, Yoshika; Fukuda, Mitsuru; Takao, Yosuke; Ozano, Takahiro; Sakuramoto, Hikaru; Wang, Kuan Wei

2011-12-01

Urgent measures for indoor air pollution caused by volatile organic compounds are required in urban areas of China. Considering indoor air concentration levels and hazardous properties, formaldehyde and benzene should be given priority for pollution control in China. The authors proposed the use of air-cleaning devices, including stand-alone room air cleaners and in-duct devices. This study aimed to find the best combination of sorption and decomposition filters for the simultaneous removal of formaldehyde and benzene, employing four types of air filter units: an activated charcoal filter (ACF), an ACF impregnated with a trapping agent for acidic gases (ACID), a MnO2 filter (MDF) for oxidative decomposition of formaldehyde at room temperature and a photocatalyst filter (PHOTO) coupled with a parallel beam ultraviolet (UV) irradiation device. The performance of the combined systems under air flow rates of 35-165 m3 h(-1) was evaluated in a test chamber (2 m3) with a constant gas generation system. The experimental results and data analysis using a kinetic approach showed the combined system of ACF, PHOTO and MDF significantly reduced both concentrations of formaldehyde and benzene in air without any unpleasant odours caused by the UV-induced photocatalytic reaction. The system was then evaluated in a full-size laboratory (22 m3). This test proved the practical performance of the system even at full scale, and also suggested that the filters should be arranged in the order of PHOTO/ACF/MDF from upstream to downstream. The proposed system has the potential of being used for improving indoor air quality of houses and buildings in China.

Test Operations Procedure (TOP) 08-2-197 Chemical Protection Testing of Sorbent-Based Air Purification Components (APCs)

DTIC Science & Technology

2016-06-24

APC’s ability to filter air in a chemically contaminated environment. 15. SUBJECT TERMS Air purification component; APC; filtration fabric...FF, filter media, collective protection; individual protection. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18...incoming air. The intent of this process is to produce traceable, quantifiable, and defensible data that can be used to analyze an APC’s ability to filter

40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face) and HEPA filters; and supplied-air respirator operated in pressure...

40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face) and HEPA filters; and supplied-air respirator operated in pressure...

40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face) and HEPA filters; and supplied-air respirator operated in pressure...

40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face) and HEPA filters; and supplied-air respirator operated in pressure...

Fractional kalman filter to estimate the concentration of air pollution

NASA Astrophysics Data System (ADS)

Vita Oktaviana, Yessy; Apriliani, Erna; Khusnul Arif, Didik

2018-04-01

Air pollution problem gives important effect in quality environment and quality of human’s life. Air pollution can be caused by nature sources or human activities. Pollutant for example Ozone, a harmful gas formed by NOx and volatile organic compounds (VOCs) emitted from various sources. The air pollution problem can be modeled by TAPM-CTM (The Air Pollution Model with Chemical Transport Model). The model shows concentration of pollutant in the air. Therefore, it is important to estimate concentration of air pollutant. Estimation method can be used for forecast pollutant concentration in future and keep stability of air quality. In this research, an algorithm is developed, based on Fractional Kalman Filter to solve the model of air pollution’s problem. The model will be discretized first and then it will be estimated by the method. The result shows that estimation of Fractional Kalman Filter has better accuracy than estimation of Kalman Filter. The accuracy was tested by applying RMSE (Root Mean Square Error).

[The use of individual protective devices for decreasing the microbial contamination of the inhaled air].

PubMed

Sedov, A V; Akin'shin, A V; Tregub, T I

1995-01-01

The work was aimed to justify application of gas masks and respirators with autonomous air source fo lower bacterial contamination of inhaled air. The studies also covered possible catch of bacteria by cotton and filters FPP-15-1.5, those composed of antimicrobial materials, containing furagin or copper ions. As the studies proved, for lower bacterial contaminations of inhaled air one can apply autonomous air source apparatus with filters made of Petrianov tissue, antimicrobial tissue (containing furagin or copper ions), as they reduce fungal content of the air. Such filters are self-disinfecting, but do not influence total contamination of the air.

SOURCE CHARACTERIZATION OF AIR FRESHENERS

EPA Science Inventory

The paper discusses research in which five air fresheners of two styles were analyzed for their constituent volatile organic compounds. Both styles were refills to be inserted into heated electric plug-in units; one refill released the fragrance from a gel pack insert and the oth...

Airborne irritant contact dermatitis due to synthetic fibres from an air-conditioning filter.

PubMed

Patiwael, Jiska A; Wintzen, Marjolein; Rustemeyer, Thomas; Bruynzeel, Derk P

2005-03-01

We describe 8 cases of occupational airborne irritant contact dermatitis in intensive care unit (ICU) employees caused by synthetic (polypropylene and polyethylene) fibres from an air-conditioning filter. Not until a workplace investigation was conducted, was it possible to clarify the unusual sequence of events. High filter pressure in the intensive care air-conditioning system, maintained to establish an outward airflow and prevent microorganisms from entering the ward, probably caused fibres from the filter to become airborne. Upon contact with air-exposed skin, fibres subsequently provoked skin irritation. Test periods in the ICU with varying filter pressures, in an attempt to improve environmental conditions, led to even higher filter pressure levels and more complaints. The sometimes-very-low humidity might have contributed to development of skin irritation. The fact that most patients recovered quickly after treatment with emollients and changing the filters made it most likely that the airborne dermatitis was of an irritant nature.

High Efficiency, Transparent, Reusable, and Active PM2.5 Filters by Hierarchical Ag Nanowire Percolation Network.

PubMed

Jeong, Seongmin; Cho, Hyunmin; Han, Seonggeun; Won, Phillip; Lee, Habeom; Hong, Sukjoon; Yeo, Junyeob; Kwon, Jinhyeong; Ko, Seung Hwan

2017-07-12

Air quality has become a major public health issue in Asia including China, Korea, and India. Particulate matters are the major concern in air quality. We present the first environmental application demonstration of Ag nanowire percolation network for a novel, electrical type transparent, reusable, and active PM2.5 air filter although the Ag nanowire percolation network has been studied as a very promising transparent conductor in optoelectronics. Compared with previous particulate matter air filter study using relatively weaker short-range intermolecular force in polar polymeric nanofiber, Ag nanowire percolation network filters use stronger long-range electrostatic force to capture PM2.5, and they are highly efficient (>99.99%), transparent, working on an active mode, low power consumption, antibacterial, and reusable after simple washing. The proposed new particulate matter filter can be applied for a highly efficient, reusable, active and energy efficient filter for wearable electronics application.

Apparatus and method for maintaining an article at a temperature that is less than the temperature of the ambient air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klett, James; Klett, Lynn

An apparatus for maintaining the temperature of an article at a temperature that is below the ambient air temperature includes an enclosure having an outer wall that defines an interior chamber for holding a volume of sealed air. An insert is disposed inside of the chamber and has a body that is made of a porous graphite foam material. A vacuum pump penetrates the outer wall and fluidly connects the sealed air in the interior chamber with the ambient air outside of the enclosure. The temperatures of the insert and article is maintained at temperatures that are below the ambientmore » air temperature when a volume of a liquid is wicked into the pores of the porous insert and the vacuum pump is activated to reduce the pressure of a volume of sealed air within the interior chamber to a pressure that is below the vapor pressure of the liquid.« less

Consequences of air around an ionization chamber: Are existing solid phantoms suitable for reference dosimetry on an MR-linac?

PubMed

Hackett, S L; van Asselen, B; Wolthaus, J W H; Kok, J G M; Woodings, S J; Lagendijk, J J W; Raaymakers, B W

2016-07-01

A protocol for reference dosimetry for the MR-linac is under development. The 1.5 T magnetic field changes the mean path length of electrons in an air-filled ionization chamber but has little effect on the electron trajectories in a surrounding phantom. It is therefore necessary to correct the response of an ionization chamber for the influence of the magnetic field. Solid phantoms are used for dosimetry measurements on the MR-linac, but air is present between the chamber wall and phantom insert. This study aimed to determine if this air influences the ion chamber measurements on the MR-linac. The absolute response of the chamber and reproducibility of dosimetry measurements were assessed on an MR-linac in solid and water phantoms. The sensitivity of the chamber response to the distribution of air around the chamber was also investigated. Measurements were performed on an MR-linac and replicated on a conventional linac for five chambers. The response of three waterproof chambers was measured with air and with water between the chamber and the insert to measure the influence of the air volume on absolute chamber response. The distribution of air around the chamber was varied indirectly by rotating each chamber about the longitudinal chamber axis in a solid phantom and a water phantom (waterproof chambers only) and measuring the angular dependence of the chamber response, and varied directly by displacing the chamber in the phantom insert using a paper shim positioned at different orientations between the chamber casing and the insert. The responses of the three waterproof chambers measured on the MR-linac were 0.7%-1.2% higher with water than air in the chamber insert. The responses of the chambers on the conventional linac changed by less than 0.3% when air in the insert was replaced with water. The angular dependence of the chambers ranged from 0.6% to 1.9% in the solid phantom on the MR-linac but was less than 0.5% in water on the MR-linac and less than 0.3% in the solid phantom on the conventional linac. Inserting a shim around the chamber induced changes of the chamber response in a magnetic field of up to 2.2%, but the change in chamber response on the conventional linac was less than 0.3%. The interaction between the magnetic field and secondary electrons in the air around the chamber reduces the charge collected from 0.7% to 1.2%. The large angular dependence of ion chambers measured in the plastic phantom in a magnetic field appears to arise from a change of air distribution as the chamber is moved within the insert, rather than an intrinsic isotropy of the chamber sensitivity to radiation. It is recommended that reference dosimetry measurements on the MR-linac can be performed only in water, rather than in existing plastic phantoms.

PubMed search filters for the study of putative outdoor air pollution determinants of disease

PubMed Central

Curti, Stefania; Gori, Davide; Di Gregori, Valentina; Farioli, Andrea; Baldasseroni, Alberto; Fantini, Maria Pia; Christiani, David C; Violante, Francesco S; Mattioli, Stefano

2016-01-01

Objectives Several PubMed search filters have been developed in contexts other than environmental. We aimed at identifying efficient PubMed search filters for the study of environmental determinants of diseases related to outdoor air pollution. Methods We compiled a list of Medical Subject Headings (MeSH) and non-MeSH terms seeming pertinent to outdoor air pollutants exposure as determinants of diseases in the general population. We estimated proportions of potentially pertinent articles to formulate two filters (one ‘more specific’, one ‘more sensitive’). Their overall performance was evaluated as compared with our gold standard derived from systematic reviews on diseases potentially related to outdoor air pollution. We tested these filters in the study of three diseases potentially associated with outdoor air pollution and calculated the number of needed to read (NNR) abstracts to identify one potentially pertinent article in the context of these diseases. Last searches were run in January 2016. Results The ‘more specific’ filter was based on the combination of terms that yielded a threshold of potentially pertinent articles ≥40%. The ‘more sensitive’ filter was based on the combination of all search terms under study. When compared with the gold standard, the ‘more specific’ filter reported the highest specificity (67.4%; with a sensitivity of 82.5%), while the ‘more sensitive’ one reported the highest sensitivity (98.5%; with a specificity of 47.9%). The NNR to find one potentially pertinent article was 1.9 for the ‘more specific’ filter and 3.3 for the ‘more sensitive’ one. Conclusions The proposed search filters could help healthcare professionals investigate environmental determinants of medical conditions that could be potentially related to outdoor air pollution. PMID:28003291

75 FR 26898 - Determination of Attainment for PM-10; Fort Hall PM-10 Nonattainment Area, Idaho

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-13

... 2009. \\9\\ FRMs are manual samplers that pull air through a filter for 24 hours (midnight to midnight... of the filter and the volume of air drawn through it. In 2008, an additional filter-based PM-10... Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing under the Clean Air Act (CAA) to determine...

40 CFR 721.10575 - 1-Propanone, 1,1'-(oxydi-4,1-phenylene)bis[2-hydroxy-2-methyl-.

Code of Federal Regulations, 2013 CFR

2013-07-01

...), R100, or P100 filters. (B) NIOSH-certified air-purifying, tight-fitting full-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters. (C) NIOSH-certified powered air-purifying respirator equipped with a loose-fitting hood or helmet and high efficiency particulate air (HEPA) filters...

40 CFR 721.10575 - 1-Propanone, 1,1'-(oxydi-4,1-phenylene)bis[2-hydroxy-2-methyl-.

Code of Federal Regulations, 2014 CFR

2014-07-01

...), R100, or P100 filters. (B) NIOSH-certified air-purifying, tight-fitting full-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters. (C) NIOSH-certified powered air-purifying respirator equipped with a loose-fitting hood or helmet and high efficiency particulate air (HEPA) filters...

122. View in subway showing air filters for unit turbinegenerator ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

122. View in subway showing air filters for unit turbine-generator unit no. 3; looking north. To the left is opening through wall which brings fresh air into the filters; this opening is above the tailrace. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

Sequential cooling insert for turbine stator vane

DOEpatents

Jones, Russell B.; Krueger, Judson J.; Plank, William L.

2014-04-01

A sequential impingement cooling insert for a turbine stator vane that forms a double impingement for the pressure and suction sides of the vane or a triple impingement. The insert is formed from a sheet metal formed in a zigzag shape that forms a series of alternating impingement cooling channels with return air channels, where pressure side and suction side impingement cooling plates are secured over the zigzag shaped main piece. Another embodiment includes the insert formed from one or two blocks of material in which the impingement channels and return air channels are machined into each block.

Sequential cooling insert for turbine stator vane

DOEpatents

Jones, Russel B; Krueger, Judson J; Plank, William L

2014-11-04

A sequential impingement cooling insert for a turbine stator vane that forms a double impingement for the pressure and suction sides of the vane or a triple impingement. The insert is formed from a sheet metal formed in a zigzag shape that forms a series of alternating impingement cooling channels with return air channels, where pressure side and suction side impingement cooling plates are secured over the zigzag shaped main piece. Another embodiment includes the insert formed from one or two blocks of material in which the impingement channels and return air channels are machined into each block.

High Efficiency Particulate Air (HEPA) Filter Generation, Characterization, and Disposal Experiences at the Oak Ridge National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coffey, D. E.

2002-02-28

High Efficiency Particulate Air filtration is an essential component of the containment and ventilation systems supporting the research and development activities at the Oak Ridge National Laboratory. High Efficiency Particulate Air filters range in size from 7.6cm (3 inch) by 10.2 cm (4 inch) cylindrical shape filters to filter array assemblies up to 2.1 m (7 feet) high by 1.5 m (5 feet) wide. Spent filters are grouped by contaminates trapped in the filter media and become one of the components in the respective waste stream. Waste minimization and pollution prevention efforts are applied for both radiological and non-radiological applications.more » Radiological applications include laboratory hoods, glove boxes, and hot cells. High Efficiency Particulate Air filters also are generated from intake or pre-filtering applications, decontamination activities, and asbestos abatement applications. The disposal avenues include sanitary/industrial waste, Resource Conservation and Recovery Act and Toxic Substance Control Act, regulated waste, solid low-level waste, contact handled transuranic, and remote handled transuranic waste. This paper discusses characterization and operational experiences associated with the disposal of the spent filters across multiple applications.« less

Infiltration of forest fire and residential wood smoke: an evaluation of air cleaner effectiveness.

PubMed

Barn, Prabjit; Larson, Timothy; Noullett, Melanie; Kennedy, Susan; Copes, Ray; Brauer, Michael

2008-09-01

Communities impacted by fine-particle air pollution (particles with an aerodynamic diameter less than 2.5 microm; PM(2.5)) from forest fires and residential wood burning require effective, evidence-based exposure-reduction strategies. Public health recommendations during smoke episodes typically include advising community members to remain indoors and the use of air cleaners, yet little information is available on the effectiveness of these measures. Our study attempted to address the following objectives: to measure indoor infiltration factor (F(inf)) of PM(2.5) from forest fires/wood smoke, to determine the effectiveness of high-efficiency particulate air (HEPA) filter air cleaners in reducing indoor PM(2.5), and to analyze the home determinants of F(inf) and air cleaner effectiveness (ACE). We collected indoor/outdoor 1-min PM(2.5) averages and 48-h outdoor PM(2.5) filter samples for 21 winter and 17 summer homes impacted by wood burning and forest fire smoke, respectively, during 2004-2005. A portable HEPA filter air cleaner was operated indoors with the filter removed for one of two sampling days. Particle F(inf) and ACE were calculated for each home using a recursive model. We found mean F(inf)+/-SD was 0.27+/-0.18 and 0.61+/-0.27 in winter (n=19) and summer (n=13), respectively, for days when HEPA filters were not used. Lower F(inf)+/-SD values of 0.10+/-0.08 and 0.19+/-0.20 were found on corresponding days when HEPA filters were in place. Mean+/-SD ACE ([F(inf) without filter-F(inf) with filter]/F(inf) without filter) in winter and summer were 55+/-38% and 65+/-35%, respectively. Number of windows and season predicted F(inf) (P<0.001). No significant predictors of ACE were identified. Our findings show that remaining indoors combined with use of air cleaner can effectively reduce PM(2.5) exposure during forest fires and residential wood burning.

Mold occurring on the air cleaner high-efficiency particulate air filters used in the houses of child patients with atopic dermatitis.

PubMed

Kim, Seong Hwan; Ahn, Geum Ran; Son, Seung Yeol; Bae, Gwi-Nam; Yun, Yeo Hong

2014-09-01

Fungi are the known sources of irritation associated with atopic diseases (e.g., asthma, allergic rhinoconjunctivitis, and atopic eczema). To quantitatively estimate their presence in the indoor environment of atopic dermatitis-inflicted child patient's houses (ADCPHs), the high-efficiency particulate air (HEPA) filters installed inside the air cleaners of three different ADCPHs were investigated for the presence of mold. The air cleaner HEPA filters obtained from the three different ADCPHs were coded as HEPA-A, -B, and -C, respectively, and tested for the presence of mold. The colony forming units (CFUs) corresponding to the HEPA-A, -B, and -C filters were estimated to be 6.51 × 10(2) ± 1.50 × 10(2) CFU/cm(2), 8.72 × 10(2) ± 1.69 × 10(2) CFU/cm(2), and 9.71 × 10(2) ± 1.35 × 10(2) CFU/cm(2), respectively. Aspergillus, Penicillium, Alternaria, Cladosporium, Trichoderma, and other fungal groups were detected in the 2,494 isolates. The distribution of these fungal groups differed among the three filters. Cladosporium was the major fungal group in filters HEPA-A and -C, whereas Penicillium was the major fungal group in the filter HEPA-B. Nine fungal species, including some of the known allergenic species, were identified in these isolates. Cladosporium cladosporioides was the most common mold among all the three filters. This is the first report on the presence of fungi in the air cleaner HEPA filters from ADCPHs in Korea.

Quantitative filter forensics for indoor particle sampling.

PubMed

Haaland, D; Siegel, J A

2017-03-01

Filter forensics is a promising indoor air investigation technique involving the analysis of dust which has collected on filters in central forced-air heating, ventilation, and air conditioning (HVAC) or portable systems to determine the presence of indoor particle-bound contaminants. In this study, we summarize past filter forensics research to explore what it reveals about the sampling technique and the indoor environment. There are 60 investigations in the literature that have used this sampling technique for a variety of biotic and abiotic contaminants. Many studies identified differences between contaminant concentrations in different buildings using this technique. Based on this literature review, we identified a lack of quantification as a gap in the past literature. Accordingly, we propose an approach to quantitatively link contaminants extracted from HVAC filter dust to time-averaged integrated air concentrations. This quantitative filter forensics approach has great potential to measure indoor air concentrations of a wide variety of particle-bound contaminants. Future studies directly comparing quantitative filter forensics to alternative sampling techniques are required to fully assess this approach, but analysis of past research suggests the enormous possibility of this approach. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Numerical study of canister filters with alternatives filter cap configurations

NASA Astrophysics Data System (ADS)

Mohammed, A. N.; Daud, A. R.; Abdullah, K.; Seri, S. M.; Razali, M. A.; Hushim, M. F.; Khalid, A.

2017-09-01

Air filtration system and filter play an important role in getting a good quality air into turbo machinery such as gas turbine. The filtration system and filter has improved the quality of air and protect the gas turbine part from contaminants which could bring damage. During separation of contaminants from the air, pressure drop cannot be avoided but it can be minimized thus helps to reduce the intake losses of the engine [1]. This study is focused on the configuration of the filter in order to obtain the minimal pressure drop along the filter. The configuration used is the basic filter geometry provided by Salutary Avenue Manufacturing Sdn Bhd. and two modified canister filter cap which is designed based on the basic filter model. The geometries of the filter are generated by using SOLIDWORKS software and Computational Fluid Dynamics (CFD) software is used to analyse and simulates the flow through the filter. In this study, the parameters of the inlet velocity are 0.032 m/s, 0.063 m/s, 0.094 m/s and 0.126 m/s. The total pressure drop produce by basic, modified filter 1 and 2 is 292.3 Pa, 251.11 Pa and 274.7 Pa. The pressure drop reduction for the modified filter 1 is 41.19 Pa and 14.1% lower compared to basic filter and the pressure drop reduction for modified filter 2 is 17.6 Pa and 6.02% lower compared to the basic filter. The pressure drops for the basic filter are slightly different with the Salutary Avenue filter due to limited data and experiment details. CFD software are very reliable in running a simulation rather than produces the prototypes and conduct the experiment thus reducing overall time and cost in this study.

Indoor-outdoor relationships of PM2.5 in four residential dwellings in winter in the Yangtze River Delta, China.

PubMed

Wang, Fang; Meng, Dan; Li, Xiuwei; Tan, Junjie

2016-08-01

Indoor and outdoor air PM2.5 concentrations in four residential dwellings characterized with different building envelope air tightness levels and HVAC-filter configurations in Yangtze River Delta (YRD) were measured during winter periods in 2014-2015. Steady-state models for indoor PM2.5 were developed for each of the tested dwellings, based on mass balance equation. The indoor air PM2.5 concentrations in the four tested apartments were significantly different. The lowest geometric mean values of indoor air PM2.5 concentrations, I/O ratios, and infiltration factor were observed in D3 with high air tightness and without HVAC-filter system (26.0 μg/m(3), 0.197, and 0.167, respectively), while the highest geometric mean values of indoor air PM2.5 concentrations, I/O ratios, and infiltration factor were observed in D1 (64.9 μg/m(3), 0.876, and 0.867, respectively). For apartment D1 with normal air tightness and without any HVAC-filter system, indoor air PM2.5 concentrations were significantly correlated with outdoor PM2.5 concentrations, especially in severe ambient pollution days, when closed windows can only play a very weak role on the decline of indoor PM2.5 concentrations. With the enhancement of building air tightness, the indoor air PM2.5 concentrations can be decreased effectively and don't vary as much in response to fluctuations in ambient concentrations. For buildings with normal air tightness, the use of HVAC-filter combinations will decrease the indoor PM2.5 significantly. However, for buildings with enhanced air tightness, the only use of fresh makeup air supply system with filter may increase the indoor PM2.5 concentrations. The improvement of filter efficiency for both fresh makeup air and indoor recirculated air are very important. However, purifiers for indoor recirculated air were highly recommended for all buildings. Copyright © 2016 Elsevier Ltd. All rights reserved.

40 CFR 63.11567 - Who implements and enforces this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

...). 2. A high-efficiency air filter or fiber bed filter a. Inlet gas temperature b, andb. Pressure drop...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt...

Are too many inferior vena cava filters used? Controversial evidences in different clinical settings: a narrative review.

PubMed

Dalla Vestra, Michele; Grolla, Elisabetta; Bonanni, Luca; Pesavento, Raffaele

2018-03-01

The use of inferior vena cava filters to prevent pulmonary embolism is increasing mainly because of indications that appear to be unclearly codified and recommended. The evidence supporting this approach is often heterogeneous, and mainly based on observational studies and consensus opinions, while the insertion of an IVC filter exposes patients to the risk of complications and increases health care costs. Thus, several proposed indications for an IVC filter placement remain controversial. We attempt to review the proof on the efficacy and safety of IVC filters in several "special" clinical settings, and assess the robustness of the available evidence for any specific indication to place an IVC filter.

Reducing emissions by using special air filters for internal combustion engines

NASA Astrophysics Data System (ADS)

Birtok-Băneasă, C.; Raţiu, S. A.; Alexa, V.; Crăciun, A. L.; Josan, A.; Budiul-Berghian, A.

2017-05-01

This paper presents the experimental methodology to carry out functional performance tests for an air filter with a particular design of its housing, generically named Super absorbing YXV „Air by Corneliu”, patented and homologated by the Romanian Automotive Registry, to which numerous prizes and medals were awarded at national and international innovations salons. The tests were carried out in the Internal Combustion Engines Laboratory, within the specialization “Road vehicles” belonging to the Faculty of Engineering Hunedoara, component of Politehnica University of Timisoara. The scope of the study is to optimise the air intake into the engine cylinders by reducing the gas-dynamic resistances caused by the air filter and, therefore, to achieve higher energy efficiency, i.e. fuel consumption reduction and engine performance increase. We present some comparative values of various operating parameters of the engine fitted, in the first measuring session, with the original filter, and then with the studied filter. The data collected shows a reduction in fuel consumption by using this type of filter, which leads to lower emissions.

Impact of Air Filter Material on Metal Oxide Semiconductor (MOS) Device Characteristics in HF Vapor Environment

NASA Astrophysics Data System (ADS)

Hsiao, Chih-Wen; Lou, Jen-Chung; Yeh, Ching-Fa; Hsieh, Chih-Ming; Lin, Shiuan-Jeng; Kusumi, Toshio

2004-05-01

Airborne molecular contamination (AMC) is becoming increasingly important as devices are scaled down to the nanometer generation. Optimum ultra low penetration air (ULPA) filter technology can eliminate AMC. In a cleanroom, however, the acid vapor generated from the cleaning process may degrade the ULPA filter, releasing AMC to the air and the surface of wafers, degrading the electrical characteristics of devices. This work proposes the new PTFE ULPA filter, which is resistant to acid vapor corrosion, to solve this problem. Experimental results demonstrate that the PTFE ULPA filter can effectively eliminate the AMC and provide a very clean cleanroom environment.

Room air monitor for radioactive aerosols

DOEpatents

Balmer, D.K.; Tyree, W.H.

1987-03-23

A housing assembly for use with a room air monitor for simultaneous collection and counting of suspended particles includes a casing containing a combination detector-preamplifier system at one end, a filter system at the other end, and an air flow system consisting of an air inlet formed in the casing between the detector-preamplifier system and the filter system and an air passageway extending from the air inlet through the casing and out the end opposite the detector-preamplifier combination. The filter system collects suspended particles transported directly through the housing by means of the air flow system, and these particles are detected and examined for radioactivity by the detector-preamplifier combination. 2 figs.

Temperature Tunable Air-Gap Etalon Filter

NASA Technical Reports Server (NTRS)

Krainak, Michael A.; Stephen, Mark A.; Lunt, David L.

1998-01-01

We report on experimental measurements of a temperature tuned air-gap etalon filter. The filter exhibits temperature dependent wavelength tuning of 54 pm/C. It has a nominal center wavelength of 532 nm. The etalon filter has a 27 pm optical bandpass and 600 pm free spectral range (finesse approximately 22). The experimental results are in close agreement with etalon theory.

Market Investigation for Surface Supplied Diving Air Compressors

DTIC Science & Technology

1990-06-12

South Coast Air Quality Management District, 9150 Flair Drive, El Monte, CA 91731). (Non-Government standards and other publications are normally...magnetic CSA and UL approved starter in a NEMA 1 enclosure (single or three phase) correctly sized for proper voltage. It is provided with heater ele - ments...Val v 5 MIN Chance Diea; el i1 and Filter 20 MIN Chan-nc Diecsel Air Filter 5 MIN Ch-,np Compres:,cjr Air Filter 5 MIN Chango.e Compr,?sor 0 11 2) M IN

9 CFR 590.540 - Spray process drying facilities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... equipped with approved air intake filters. (d) Air shall be drawn into the drier from sources free from..., if used, shall be equipped with approved air filters at blower intake. (f) High-pressure pump heads...

9 CFR 590.540 - Spray process drying facilities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... equipped with approved air intake filters. (d) Air shall be drawn into the drier from sources free from..., if used, shall be equipped with approved air filters at blower intake. (f) High-pressure pump heads...

Radar range data signal enhancement tracker

NASA Technical Reports Server (NTRS)

1975-01-01

The design, fabrication, and performance characteristics are described of two digital data signal enhancement filters which are capable of being inserted between the Space Shuttle Navigation Sensor outputs and the guidance computer. Commonality of interfaces has been stressed so that the filters may be evaluated through operation with simulated sensors or with actual prototype sensor hardware. The filters will provide both a smoothed range and range rate output. Different conceptual approaches are utilized for each filter. The first filter is based on a combination low pass nonrecursive filter and a cascaded simple average smoother for range and range rate, respectively. Filter number two is a tracking filter which is capable of following transient data of the type encountered during burn periods. A test simulator was also designed which generates typical shuttle navigation sensor data.

Laboratory and on-road evaluations of cabin air filters using number and surface area concentration monitors.

PubMed

Qi, Chaolong; Stanley, Nick; Pui, David Y H; Kuehn, Thomas H

2008-06-01

An automotive cabin air filter's effectiveness for removing airborne particles was determined both in a laboratory wind tunnel and in vehicle on-road tests. The most penetrating particle size for the test filter was approximately 350 nm, where the filtration efficiency was 22.9 and 17.4% at medium and high fan speeds, respectively. The filtration efficiency increased for smaller particles and was 43.9% for 100 nm and 72.0% for 20 nm particles at a medium fan speed. We determined the reduction in passenger exposure to particles while driving in freeway traffic caused by a vehicle ventilation system with a cabin air filter installed. Both particle number and surface area concentration measurements were made inside the cabin and in the surrounding air. At medium fan speed, the number and surface area concentration-based exposure reductions were 65.6 +/- 6.0% and 60.6 +/- 9.4%, respectively. To distinguish the exposure reduction contribution from the filter alone and the remainder of the ventilation system, we also performed tests with and without the filter in place using the surface area monitors. The ventilation system operating in the recirculation mode with the cabin air filter installed provided the maximum protection, reducing the cabin particle concentration exponentially over time and usually taking only 3 min to reach 10 microm2/cm3 (a typical office air condition) under medium fan speed.

Evaluation of Low-Pressure Drop Antimicrobial and Hybrid Air Filters

DTIC Science & Technology

2006-09-01

purification of aerosol- contaminated air streams has been performed by mechanical filtration. Existing particle filters will stop bacterial and viral...or hybrid low-∆P antimicrobial particulate filter materials. 1.2 Background Traditional purification of aerosol- contaminated air streams has...Plastics, Lima , Ohio). Each path runs through a test article and thence through one AGI-30 all-glass impinger (Chemglass, Vineland, N.J.) partially

Method and apparatus for duct sealing using a clog-resistant insertable injector

DOEpatents

Wang, Duo; Modera, Mark P.

2010-12-14

A method for forming a duct access region through one side of a previously installed air duct, wherein the air duct has an air flow with an air flow direction by inserting an aerosol injector into a previously installed air duct through the access region. The aerosol injector includes a liquid tube having a liquid tube orifice for ejecting a liquid to be atomized; and a propellant cap. The method is accomplished by aligning the aerosol injector with the direction of air flow in the duct; activating an air flow within the duct; and spraying a sealant through the aerosol injector to seal the duct in the direction of the air flow.

Ozone Air Purifiers: Can They Improve Asthma Symptoms?

MedlinePlus

... and cleaner. However, ozone generators don't actually filter out the small particles that trigger asthma. Inhaling ... air — but they may generate unwanted ozone. Air filters that remove small particles — such as high-efficiency ...

Forced-air warming blowers: An evaluation of filtration adequacy and airborne contamination emissions in the operating room.

PubMed

Albrecht, Mark; Gauthier, Robert L; Belani, Kumar; Litchy, Mark; Leaper, David

2011-05-01

Forced-air warming (FAW) is widely used to prevent hypothermia during surgical procedures. The airflow from these blowers is often vented near the operative site and should be free of contaminants to minimize the risk of surgical site infection. Popular FAW blowers contain a 0.2-μm rated intake filter to reduce these risks. However, there is little evidence that the efficiency of the intake filter is adequate to prevent airborne contamination emissions or protect the internal air path from microbial contamination buildup. Five new intake filters were obtained directly from the manufacturer (Bair Hugger 505, model 200708D; Arizant Healthcare, Eden Prairie, MN), and 5 model 200708C filters currently in hospital use were removed from FAW devices. The retention efficiency of these filters was assessed using a monodisperse sodium chloride aerosol. In the same hospitals, internal air path surface swabs and hose outlet particle counts were performed on 52 forced-air warming devices (all with the model 200708C filter) to assess internal microbial buildup and airborne contamination emissions. Intake filter retention efficiency at 0.2 μm was 93.8% for the 200708C filter and 61.3% at for the 200708D filter. The 200708D filter obtained directly from the manufacturer has a thinner filtration media than the 200708C filter in current hospital use, suggesting that the observed differences in retention efficiency were due to design changes. Fifty-eight percent of the FAW blowers evaluated were internally generating and emitting airborne contaminants, with microorganisms detected on the internal air path surfaces of 92.3% of these blowers. Isolates of Staphylococcus aureus, coagulase-negative Staphylococcus, and methicillin-resistant S aureus were detected in 13.5%, 3.9%, and 1.9% of FAW blowers, respectively. The design of popular FAW devices using the 200708C filter was found to be inadequate for preventing the internal buildup and emission of microbial contaminants into the operating room. Substandard intake filtration allowed airborne contaminants (both viable and nonviable) to penetrate the intake filter and reversibly attach to the internal surfaces within the FAW blowers. The reintroduction of these contaminants into the FAW blower air stream was detected and could contribute to the risk of cross-infection. Given the deficiencies identified with the 200708C intake filter, the introduction of a new filter (model 200708D) with substantially lower retention efficiency is of concern. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Spin-Orbit Torque and Spin Pumping in YIG/Pt with Interfacial Insertion Layers (Postprint)

DTIC Science & Technology

2018-05-03

Distribution Statement A. Approved for public release: distribution unlimited. © 2018 AMERICAN INSTITUTE OF PHYSICS (STINFO COPY) AIR FORCE RESEARCH ...SPONSORING/MONITORING AGENCY ACRONYM(S) Air Force Research Laboratory Materials and Manufacturing Directorate Wright-Patterson Air Force Base, OH... observe a large enhancement of Gilbert damping with the insertion of Py that cannot be accounted for solely by spin pumping, revealing significant spin

Curve fitting air sample filter decay curves to estimate transuranic content.

PubMed

Hayes, Robert B; Chiou, Hung Cheng

2004-01-01

By testing industry standard techniques for radon progeny evaluation on air sample filters, a new technique is developed to evaluate transuranic activity on air filters by curve fitting the decay curves. The industry method modified here is simply the use of filter activity measurements at different times to estimate the air concentrations of radon progeny. The primary modification was to not look for specific radon progeny values but rather transuranic activity. By using a method that will provide reasonably conservative estimates of the transuranic activity present on a filter, some credit for the decay curve shape can then be taken. By carrying out rigorous statistical analysis of the curve fits to over 65 samples having no transuranic activity taken over a 10-mo period, an optimization of the fitting function and quality tests for this purpose was attained.

40 CFR 63.1187 - What do I need to know about operations, maintenance, and monitoring plans?

Code of Federal Regulations, 2011 CFR

2011-07-01

... include: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air...

40 CFR 63.1187 - What do I need to know about operations, maintenance, and monitoring plans?

Code of Federal Regulations, 2013 CFR

2013-07-01

... include: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air...

40 CFR 63.1187 - What do I need to know about operations, maintenance, and monitoring plans?

Code of Federal Regulations, 2012 CFR

2012-07-01

... include: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air...

40 CFR 63.1187 - What do I need to know about operations, maintenance, and monitoring plans?

Code of Federal Regulations, 2014 CFR

2014-07-01

... include: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air...

Efficacy of photocatalytic HEPA filter on microorganism removal.

PubMed

Chuaybamroong, P; Chotigawin, R; Supothina, S; Sribenjalux, P; Larpkiattaworn, S; Wu, C-Y

2010-06-01

This study assessed the application of photocatalytic oxidation (PCO) to the high efficiency particulate air (HEPA) filter for disinfection of airborne microorganisms. Experiments were conducted at two TiO2 loadings (1870 +/- 169 and 3140 +/- 67 mg/m(2)) on the HEPA filter irradiated with UV-A at the intensity of 0.85 +/- 0.18 or 4.85 +/- 0.09 mW/cm(2) under two relative humidity conditions (45 +/- 5% and 75 +/- 5%). Inactivation and penetration of four microorganisms were tested, including Aspergillus niger, Penicillium citrinum, Staphylococcus epidermidis, and Bacillus subtilis. It was found that microorganisms retained on a photocatalytic filter were inactivated around 60-80% and even 100% for S. epidermidis when the PCO reactions occurred. Lower penetration was also found from the photocatalytic filter for all airborne microorganisms. High humidity decreased photocatalysis efficacy. Increasing TiO2 loading or irradiance intensity did not substantially affect its disinfection capability. The high efficiency particulate air filter is used widely to remove particulates and microorganisms from the air stream. However, the filter may become a source of microbes if those retained microorganisms proliferate and re-entrain back into the filtered air. This study demonstrates that such a problem can be handled effectively by using photocatalytic reactions to inactivate those confined microorganisms. A 60-100% microbe reduction can be achieved for a wide variety of microorganisms to provide better indoor air quality for hospitals, offices, and domestic applications.

Filters from taxis air conditioning system: A tool to characterize driver's occupational exposure to bioburden?

PubMed

Viegas, Carla; Monteiro, Ana; Dos Santos, Mateus; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Quintal Gomes, Anita; Marchand, Geneviève; Lacombe, Nancy; Viegas, Susana

2018-07-01

Bioburden proliferation in filters from air conditioning systems of taxis represents a possible source of occupational exposure. The aim of this study was to determine the occurrence of fungi and bacteria in filters from the air conditioning system of taxis used for patient transportation and to assess the exposure of drivers to bioburden. Filters from the air conditioning systems of 19 taxis and 28 personal vehicles (used as controls) operating in three Portuguese cities including the capital Lisbon, were collected during the winter season. The occurrence and significance of bioburden detected in the different vehicles are reported and discussed in terms of colony-forming units (CFU) per 1 m 2 of filter area and by the identification of the most frequently detected fungal isolates based on morphology. Azole-resistant mycobiota, fungal biomass, and molecular detection of Aspergillus species/strains were also determined. Bacterial growth was more prevalent in taxis (63.2%) than in personal vehicles (26.3%), whereas fungal growth was more prevalent in personal vehicles (53.6%) than in taxis (21.1-31.6%). Seven different azole-resistant species were identified in this study in 42.1% taxi filters. Levels of fungal biomass were above the detection limit in 63% taxi filters and in 75% personal vehicle filters. No toxigenic species were detected by molecular analysis in the assessed filters. The results obtained show that bioburden proliferation occurs widely in filters from the air conditioning systems of taxis, including the proliferation of azole-resistant fungal species, suggesting that filters should be replaced more frequently. The use of culture based-methods and molecular tools combined enabled an improved risk characterization in this setting. Copyright © 2018 Elsevier Inc. All rights reserved.

Use of dust fall filters as passive samplers for metal concentrations in air for communities near contaminated mine tailings

PubMed Central

Beamer, P.I.; Sugeng, A. J.; Kelly, M.D.; Lothrop, N.; Klimecki, W.; Wilkinson, S.T.; Loh, M.

2014-01-01

Mine tailings are a source of metal exposures in many rural communities. Multiple air samples are necessary to assess the extent of exposures and factors contributing to these exposures. However, air sampling equipment is costly and requires trained personnel to obtain measurements, limiting the number of samples that can be collected. Simple, low-cost methods are needed to allow for increased sample collection. The objective of our study was to assess if dust fall filters can serve as passive air samplers and be used to characterize potential exposures in a community near contaminated mine tailings. We placed filters in cylinders, concurrently with active indoor air samplers, in 10 occupied homes. We calculated an estimated flow rate by dividing the mass on each dust fall filter by the bulk air concentration and the sampling duration. The mean estimated flow rate for dust fall filters was significantly different during sampling periods with precipitation. The estimated flow rate was used to estimate metal concentration in the air of these homes, as well as in 31 additional homes in another rural community impacted by contaminated mine tailings. The estimated air concentrations had a significant linear association with the measured air concentrations for beryllium, manganese and arsenic (p<0.05), whose primary source in indoor air is resuspended soil from outdoors. In the second rural community, our estimated metal concentrations in air were comparable to active air sampling measurements taken previously. This passive air sampler is a simple low-cost method to assess potential exposures near contaminated mining sites. PMID:24469149

Determination of sub-part-per-million levels of formaldehyde in air using active or passive sampling on 2,4-dinitrophenylhydrazine-coated glass fiber filters and high-performance liquid chromatography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levin, J.O.; Andersson, K.; Lindahl, R.

1985-05-01

Formaldehyde is sampled from air with the use of a standard miniature glass fiber filter impregnated with 2,4-dinitrophenylhydrazine and phosphoric acid. The formaldehyde hydrazone is desorbed from the filter with acetonitrile and determined by high-performance liquid chromatography using UV detection at 365 nm. Recovery of gas-phase-generated formaldehyde as hydrazone from a 13-mm impregnated filter is 80-100% in the range 0.3-30 ..mu..g of formaldehyde. This corresponds to 0.1-10 mg/m/sup 3/ in a 3-L air sample. When the filter sampling system is used in the active mode, air can be sampled at a rate of up to 1 L/min, affording an overallmore » sensitivity of about 1 ..mu..g/m/sup 3/ based on a 60-L air sample. Results are given from measurements of formaldehyde in indoor air. The DNP-coated filters were also evaluated for passive sampling. In this case 37-mm standard glass fibers were used and the sampling rate was 55-65 mL/min in two types of dosimeters. The diffusion samplers are especially useful for personal exposure monitoring in the work environment. 24 references, 2 figures, 4 tables.« less

Assessment of the capacity of vehicle cabin air inlet filters to reduce diesel exhaust-induced symptoms in human volunteers

PubMed Central

2014-01-01

Background Exposure to particulate matter (PM) air pollution especially derived from traffic is associated with increases in cardiorespiratory morbidity and mortality. In this study, we evaluated the ability of novel vehicle cabin air inlet filters to reduce diesel exhaust (DE)-induced symptoms and markers of inflammation in human subjects. Methods Thirty healthy subjects participated in a randomized double-blind controlled crossover study where they were exposed to filtered air, unfiltered DE and DE filtered through two selected particle filters, one with and one without active charcoal. Exposures lasted for one hour. Symptoms were assessed before and during exposures and lung function was measured before and after each exposure, with inflammation assessed in peripheral blood five hours after exposures. In parallel, PM were collected from unfiltered and filtered DE and assessed for their capacity to drive damaging oxidation reactions in a cell-free model, or promote inflammation in A549 cells. Results The standard particle filter employed in this study reduced PM10 mass concentrations within the exposure chamber by 46%, further reduced to 74% by the inclusion of an active charcoal component. In addition use of the active charcoal filter was associated by a 75% and 50% reduction in NO2 and hydrocarbon concentrations, respectively. As expected, subjects reported more subjective symptoms after exposure to unfiltered DE compared to filtered air, which was significantly reduced by the filter with an active charcoal component. There were no significant changes in lung function after exposures. Similarly diesel exhaust did not elicit significant increases in any of the inflammatory markers examined in the peripheral blood samples 5 hour post-exposure. Whilst the filters reduced chamber particle concentrations, the oxidative activity of the particles themselves, did not change following filtration with either filter. In contrast, diesel exhaust PM passed through the active charcoal combination filter appeared less inflammatory to A549 cells. Conclusions A cabin air inlet particle filter including an active charcoal component was highly effective in reducing both DE particulate and gaseous components, with reduced exhaust-induced symptoms in healthy volunteers. These data demonstrate the effectiveness of cabin filters to protect subjects travelling in vehicles from diesel exhaust emissions. PMID:24621126

29 CFR 1910.1027 - Cadmium.

Code of Federal Regulations, 2010 CFR

2010-07-01

... respirators when they experience eye irritation. (C) Provide HEPA filters for powered and non-powered air.... High-efficiency particulate air (HEPA) filter means a filter capable of trapping and retaining at least..., the employer shall sample the employee(s) expected to have the highest cadmium exposures. (2) Specific...

Air filters from HVAC systems as possible source of volatile organic compounds (VOC) - laboratory and field assays

NASA Astrophysics Data System (ADS)

Schleibinger, Hans; Rüden, Henning

The emission of volatile organic compounds (VOC) from air filters of HVAC systems was to be evaluated. In a first study carbonyl compounds (14 aldehydes and two ketones) were measured by reacting them with 2,4-dinitrophenylhydrazine (DNPH). Analysis was done by HPLC and UV detection. In laboratory experiments pieces of used and unused HVAC filters were incubated in test chambers. Filters to be investigated were taken from a filter bank of a large HVAC system in the centre of Berlin. First results show that - among those compounds - formaldehyde and acetone were found in higher concentrations in the test chambers filled with used filters in comparison to those with unused filters. Parallel field measurements were carried out at the prefilter and main filter banks of the two HVAC systems. Here measurements were carried out simultaneously before and after the filters to investigate whether those aldehydes or ketones arise from the filter material on site. Formaldehyde and acetone significantly increased in concentration after the filters of one HVAC system. In parallel experiments microorganisms were proved to be able to survive on air filters. Therefore, a possible source of formaldehyde and acetone might be microbes.

Consequences of air around an ionization chamber: Are existing solid phantoms suitable for reference dosimetry on an MR-linac?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hackett, S. L., E-mail: S.S.Hackett@umcutrecht.nl

Purpose: A protocol for reference dosimetry for the MR-linac is under development. The 1.5 T magnetic field changes the mean path length of electrons in an air-filled ionization chamber but has little effect on the electron trajectories in a surrounding phantom. It is therefore necessary to correct the response of an ionization chamber for the influence of the magnetic field. Solid phantoms are used for dosimetry measurements on the MR-linac, but air is present between the chamber wall and phantom insert. This study aimed to determine if this air influences the ion chamber measurements on the MR-linac. The absolute responsemore » of the chamber and reproducibility of dosimetry measurements were assessed on an MR-linac in solid and water phantoms. The sensitivity of the chamber response to the distribution of air around the chamber was also investigated. Methods: Measurements were performed on an MR-linac and replicated on a conventional linac for five chambers. The response of three waterproof chambers was measured with air and with water between the chamber and the insert to measure the influence of the air volume on absolute chamber response. The distribution of air around the chamber was varied indirectly by rotating each chamber about the longitudinal chamber axis in a solid phantom and a water phantom (waterproof chambers only) and measuring the angular dependence of the chamber response, and varied directly by displacing the chamber in the phantom insert using a paper shim positioned at different orientations between the chamber casing and the insert. Results: The responses of the three waterproof chambers measured on the MR-linac were 0.7%–1.2% higher with water than air in the chamber insert. The responses of the chambers on the conventional linac changed by less than 0.3% when air in the insert was replaced with water. The angular dependence of the chambers ranged from 0.6% to 1.9% in the solid phantom on the MR-linac but was less than 0.5% in water on the MR-linac and less than 0.3% in the solid phantom on the conventional linac. Inserting a shim around the chamber induced changes of the chamber response in a magnetic field of up to 2.2%, but the change in chamber response on the conventional linac was less than 0.3%. Conclusions: The interaction between the magnetic field and secondary electrons in the air around the chamber reduces the charge collected from 0.7% to 1.2%. The large angular dependence of ion chambers measured in the plastic phantom in a magnetic field appears to arise from a change of air distribution as the chamber is moved within the insert, rather than an intrinsic isotropy of the chamber sensitivity to radiation. It is recommended that reference dosimetry measurements on the MR-linac can be performed only in water, rather than in existing plastic phantoms.« less

Effectiveness of photocatalytic filter for removing volatile organic compounds in the heating, ventilation, and air conditioning system.

PubMed

Yu, Kuo-Pin; Lee, Grace Whei-May; Huang, Wei-Ming; Wu, Chih-Cheng; Lou, Chia-ling; Yang, Shinhao

2006-05-01

Nowadays, the heating, ventilation, and air conditioning (HVAC) system has been an important facility for maintaining indoor air quality. However, the primary function of typical HVAC systems is to control the temperature and humidity of the supply air. Most indoor air pollutants, such as volatile organic compounds (VOCs), cannot be removed by typical HVAC systems. Thus, some air handling units for removing VOCs should be added in typical HVAC systems. Among all of the air cleaning techniques used to remove indoor VOCs, photocatalytic oxidation is an attractive alternative technique for indoor air purification and deodorization. The objective of this research is to investigate the VOC removal efficiency of the photocatalytic filter in a HVAC system. Toluene and formaldehyde were chosen as the target pollutants. The experiments were conducted in a stainless steel chamber equipped with a simplified HVAC system. A mechanical filter coated with Degussa P25 titania photocatalyst and two commercial photocatalytic filters were used as the photocatalytic filters in this simplified HVAC system. The total air change rates were controlled at 0.5, 0.75, 1, 1.25, and 1.5 hr(-1), and the relative humidity (RH) was controlled at 30%, 50%, and 70%. The ultraviolet lamp used was a 4-W, ultraviolet-C (central wavelength at 254 nm) strip light bulb. The first-order decay constant of toluene and formaldehyde found in this study ranged from 0.381 to 1.01 hr(-1) under different total air change rates, from 0.34 to 0.433 hr(-1) under different RH, and from 0.381 to 0.433 hr(-1) for different photocatalytic filters.

Effects of antimicrobial treatment on fiberglass-acrylic filters.

PubMed

Cecchini, C; Verdenelli, M C; Orpianesi, C; Dadea, G M; Cresci, A

2004-01-01

The aims of the present study were to: (i) analyse a group of antimicrobial agents and to select the most active against test microbial strains; (ii) test the effect of the antimicrobial treatment on air filters in order to reduce microbial colonization. Different kinds of antimicrobial agents were analysed to assess their compatibility with the production process of air filter media. The minimal inhibitory concentration for each antimicrobial agent was determined against a defined list of microbial strains, and an antimicrobial activity assay of filter prototypes was developed to determine the most active agent among the compatible antimicrobials. Then, the most active was chosen and added directly to the filter during the production process. The microbial colonization of treated and untreated filter media was assessed at different working times for different incubation times by stereomicroscope and scanning electron microscope analysis. Some of the antimicrobial agents analysed were more active against microbial test strains and compatible with the production process of the filter media. Filter sections analysis of treated filter media showed a significantly lower microbial colonization than those untreated, a reduction of species both in density and varieties and of the presence of bacteria and fungal hyphae with reproductive structures. This study demonstrated the ability of antimicrobial treatments to inhibit the growth of micro-organisms in filter media and subsequently to increase indoor air quality (IAQ), highlighting the value of adding antimicrobials to filter media. To make a contribution to solving the problem of microbial contamination of air filters, by demonstrating the efficacy of incorporating antimicrobial agents in the filter media to improve IAQ and health.

Whole house particle removal and clean air delivery rates for in-duct and portable ventilation systems.

PubMed

Macintosh, David L; Myatt, Theodore A; Ludwig, Jerry F; Baker, Brian J; Suh, Helen H; Spengler, John D

2008-11-01

A novel method for determining whole house particle removal and clean air delivery rates attributable to central and portable ventilation/air cleaning systems is described. The method is used to characterize total and air-cleaner-specific particle removal rates during operation of four in-duct air cleaners and two portable air-cleaning devices in a fully instrumented test home. Operation of in-duct and portable air cleaners typically increased particle removal rates over the baseline rates determined in the absence of operating a central fan or an indoor air cleaner. Removal rates of 0.3- to 0.5-microm particles ranged from 1.5 hr(-1) during operation of an in-duct, 5-in. pleated media filter to 7.2 hr(-1) for an in-duct electrostatic air cleaner in comparison to a baseline rate of 0 hr(-1) when the air handler was operating without a filter. Removal rates for total particulate matter less than 2.5 microm in aerodynamic diameter (PM2.5) mass concentrations were 0.5 hr(-1) under baseline conditions, 0.5 hr(-1) during operation of three portable ionic air cleaners, 1 hr(-1) for an in-duct 1-in. media filter, 2.4 hr(-1) for a single high-efficiency particle arrestance (HEPA) portable air cleaner, 4.6 hr(-1) for an in-duct 5-in. media filter, 4.7 hr(-1) during operation of five portable HEPA filters, 6.1 hr(-1) for a conventional in-duct electronic air cleaner, and 7.5 hr(-1) for a high efficiency in-duct electrostatic air cleaner. Corresponding whole house clean air delivery rates for PM2.5 attributable to the air cleaner independent of losses within the central ventilation system ranged from 2 m3/min for the conventional media filter to 32 m3/min for the high efficiency in-duct electrostatic device. Except for the portable ionic air cleaner, the devices considered here increased particle removal indoors over baseline deposition rates.

111. DETAIL OF FILTER DISCS ON DENVER FILTER IN CO91107. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

111. DETAIL OF FILTER DISCS ON DENVER FILTER IN CO-91-107. AS DISCS SLOWLY ROTATE, VACUUM INSIDE DISCS ATTRACT SLURRY IN THE SUMP AND DEWATERS CONCENTRATE AS DISCS MOVE THROUGH AIR. FURTHER ROTATION PASSES A BAR TO SCRAPE OFF DRIED METAL CONCENTRATE, ASSISTED BY BLASTS OF COMPRESSED AIR. METAL CONCENTRATE READY FOR SHIPMENT TO SMELTER FALLS INTO BIN BELOW. EIMCO FILTERS OPERATE SIMILARLY. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

Hybrid Filter Membrane

NASA Technical Reports Server (NTRS)

Laicer, Castro; Rasimick, Brian; Green, Zachary

2012-01-01

Cabin environmental control is an important issue for a successful Moon mission. Due to the unique environment of the Moon, lunar dust control is one of the main problems that significantly diminishes the air quality inside spacecraft cabins. Therefore, this innovation was motivated by NASA s need to minimize the negative health impact that air-suspended lunar dust particles have on astronauts in spacecraft cabins. It is based on fabrication of a hybrid filter comprising nanofiber nonwoven layers coated on porous polymer membranes with uniform cylindrical pores. This design results in a high-efficiency gas particulate filter with low pressure drop and the ability to be easily regenerated to restore filtration performance. A hybrid filter was developed consisting of a porous membrane with uniform, micron-sized, cylindrical pore channels coated with a thin nanofiber layer. Compared to conventional filter media such as a high-efficiency particulate air (HEPA) filter, this filter is designed to provide high particle efficiency, low pressure drop, and the ability to be regenerated. These membranes have well-defined micron-sized pores and can be used independently as air filters with discreet particle size cut-off, or coated with nanofiber layers for filtration of ultrafine nanoscale particles. The filter consists of a thin design intended to facilitate filter regeneration by localized air pulsing. The two main features of this invention are the concept of combining a micro-engineered straight-pore membrane with nanofibers. The micro-engineered straight pore membrane can be prepared with extremely high precision. Because the resulting membrane pores are straight and not tortuous like those found in conventional filters, the pressure drop across the filter is significantly reduced. The nanofiber layer is applied as a very thin coating to enhance filtration efficiency for fine nanoscale particles. Additionally, the thin nanofiber coating is designed to promote capture of dust particles on the filter surface and to facilitate dust removal with pulse or back airflow.

Performance Evaluation of Axial Flow AG-1 FC and Prototype FM (High Strength) HEPA Filters - 13123

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giffin, Paxton K.; Parsons, Michael S.; Wilson, John A.

High efficiency particulate air (HEPA) filters are routinely used in DOE nuclear containment activities. The Nuclear Air Cleaning Handbook (NACH) stipulates that air cleaning devices and equipment used in DOE nuclear applications must meet the American Society of Mechanical Engineers (ASME) Code on Nuclear Air and Gas Treatment (AG-1) standard. This testing activity evaluates two different axial flow HEPA filters, those from AG-1 Sections FC and FM. Section FM is under development and has not yet been added to AG-1 due to a lack of qualification data available for these filters. Section FC filters are axial flow units that utilizemore » a fibrous glass filtering medium. The section FM filters utilize a similar fibrous glass medium, but also have scrim backing. The scrim-backed filters have demonstrated the ability to endure pressure impulses capable of completely destroying FC filters. The testing activities presented herein will examine the total lifetime loading for both FC and FM filters under ambient conditions and at elevated conditions of temperature and relative humidity. Results will include loading curves, penetration curves, and testing condition parameters. These testing activities have been developed through collaborations with representatives from the National Nuclear Security Administration (NNSA), DOE Office of Environmental Management (DOE-EM), New Mexico State University, and Mississippi State University. (authors)« less

High-Tc superconductor coplanar waveguide filter

NASA Technical Reports Server (NTRS)

Chew, Wilbert; Bajuk, Louis J.; Cooley, Thomas W.; Foote, Marc C.; Hunt, Brian D.; Rascoe, Daniel L.; Riley, A. L.

1991-01-01

Coplanar waveguide (CPW) low-pass filters made of YBa2Cu3O(7-delta) (YBCO) on LaAlO3 substrates, with dimensions suited for integrated circuits, were fabricated and packaged. A complete filter gives a true idea of the advantages and difficulties in replacing thin-film metal with a high-temperature superconductor in a practical circuit. Measured insertion losses in liquid nitrogen were superior to the loss of a similar thin-film copper filter throughout the 0- to 9.5-GHz passband. These results demonstrate the performance of fully patterned YBCO in a practical CPW structure after sealing in a hermetic package.

Transfemoral Filter Eversion Technique following Unsuccessful Retrieval of Option Inferior Vena Cava Filters: A Single Center Experience.

PubMed

Posham, Raghuram; Fischman, Aaron M; Nowakowski, Francis S; Bishay, Vivian L; Biederman, Derek M; Virk, Jaskirat S; Kim, Edward; Patel, Rahul S; Lookstein, Robert A

2017-06-01

This report describes the technical feasibility of using the filter eversion technique after unsuccessful retrieval attempts of Option and Option ELITE (Argon Medical Devices, Inc, Athens, Texas) inferior vena cava (IVC) filters. This technique entails the use of endoscopic forceps to evert this specific brand of IVC filter into a sheath inserted into the common femoral vein, in the opposite direction in which the filter is designed to be removed. Filter eversion was attempted in 25 cases with a median dwell time of 134 days (range, 44-2,124 d). Retrieval success was 100% (25/25 cases), with an overall complication rate of 8%. This technique warrants further study. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

Optical air data systems and methods

NASA Technical Reports Server (NTRS)

Caldwell, Loren M. (Inventor); Tang, Shoou-Yu (Inventor); O'Brien, Martin J. (Inventor)

2009-01-01

A method for remotely sensing air outside a moving aircraft includes generating laser radiation within a swept frequency range. A portion of the laser radiation is projected from the aircraft into the air to induce scattered laser radiation. Filtered scattered laser radiation, filtered laser radiation, and unfiltered laser radiation are detected. At least one actual ratio is determined from data corresponding to the filtered scattered laser radiation and the unfiltered laser radiation. One or more air parameters are determined by correlating the actual ratio to at least one reference ratio.

Optical air data systems and methods

NASA Technical Reports Server (NTRS)

Caldwell, Loren M. (Inventor); O'Brien, Martin J. (Inventor); Tang, Shoou-Yu (Inventor)

2011-01-01

A method for remotely sensing air outside a moving aircraft includes generating laser radiation within a swept frequency range. A portion of the laser radiation is projected from the aircraft into the air to induce scattered laser radiation. Filtered scattered laser radiation, filtered laser radiation, and unfiltered laser radiation are detected. At least one actual ratio is determined from data corresponding to the filtered scattered laser radiation and the unfiltered laser radiation. One or more air parameters are determined by correlating the actual ratio to at least one reference ratio.

EVALUATION OF THE FILTER PACK FOR LONG-DURATION SAMPLING OF AMBIENT AIR

EPA Science Inventory

A 14-week filter pack (FP) sampler evaluation field study was conducted at a site near Bondville, IL to investigate the impact of weekly sampling duration. Simultaneous samples were collected using collocated filter packs (FP) from two independent air quality monitoring networks...

Model-based flow rate control for an orfice-type low-volume air sampler

USDA-ARS?s Scientific Manuscript database

The standard method of measuring air suspended particulate matter concentration per volume of air consists of continuously drawing a defined volume of air across a filter over an extended period of time, then measuring the mass of the filtered particles and dividing it by the total volume sampled ov...

40 CFR 1068.261 - What provisions apply for selling or shipping certified engines that are not yet in the certified...

Code of Federal Regulations, 2010 CFR

2010-07-01

... without air filters or other portions of the air intake system that are specifically identified by part... appropriate aftertreatment device and/or air filter, but without completing the assembly with all the... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS GENERAL...

40 CFR 1068.261 - What provisions apply for selling or shipping certified engines that are not yet in the certified...

Code of Federal Regulations, 2011 CFR

2011-07-01

... without air filters or other portions of the air intake system that are specifically identified by part... appropriate aftertreatment device and/or air filter, but without completing the assembly with all the... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS GENERAL...

Measuring Concentrations of Particulate 140La in the Air

DOE PAGES

Okada, Colin E.; Kernan, Warnick J.; Keillor, Martin E.; ...

2016-05-01

Air sampling systems were deployed to measure the concentration of radioactive material in the air during the Full-Scale Radiological Dispersal Device experiments. The air samplers were positioned 100-600 meters downwind of the release point. The filters were collected immediately and analyzed in the field. Quantities for total activity collected on the air filters are reported along with additional information to compute the average or integrated air concentrations.

Pressure-controlled terahertz filter based on 1D photonic crystal with a defective semiconductor

NASA Astrophysics Data System (ADS)

Qinwen, XUE; Xiaohua, WANG; Chenglin, LIU; Youwen, LIU

2018-03-01

The tunable terahertz (THz) filter has been designed and studied, which is composed of 1D photonic crystal (PC) containing a defect layer of semiconductor GaAs. The analytical solution of 1D defective PC (1DDPC) is deduced based on the transfer matrix method, and the electromagnetic plane wave numerical simulation of this 1DDPC is performed by using the finite element method. The calculated and simulated results have confirmed that the filtering transmittance of this 1DDPC in symmetric structure of air/(Si/SiO2) N /GaAs/(SiO2/Si) N /air is far higher than in asymmetric structure of air/(Si/SiO2) N /GaAs/(Si/SiO2) N /air, where the filtering frequency can be tuned by the external pressure. It can provide a feasible route to design the external pressure-controlled THz filter based on 1DPC with a defective semiconductor.

Ultra-wide bandpass filter based on long-period fiber gratings and the evanescent field coupling between two fibers.

PubMed

Kim, Myoung Jin; Jung, Yong Min; Kim, Bok Hyeon; Han, Won-Taek; Lee, Byeong Ha

2007-08-20

We demonstrate a fiber-based bandpass filter with an ultra-wide spectral bandwidth. The ultra-wide band feature is achieved by inscribing a long-period fiber grating (LPG) in a specially-designed low index core single mode fiber. To get the bandpass function, the evanescent field coupling between two attached fibers is utilized. By applying strain, the spectral shape of the pass-band is adjusted to flat-top and Gaussian shapes. For the flat-top case, the bandwidth is obtained ~ 160 nm with an insertion loss of ~ 2 dB. With strain, the spectral shape is switched into a Gaussian one, which has ~ 120 nm FWHM and ~ 4.18 dB insertion loss at the peak.

PubMed search filters for the study of putative outdoor air pollution determinants of disease.

PubMed

Curti, Stefania; Gori, Davide; Di Gregori, Valentina; Farioli, Andrea; Baldasseroni, Alberto; Fantini, Maria Pia; Christiani, David C; Violante, Francesco S; Mattioli, Stefano

2016-12-21

Several PubMed search filters have been developed in contexts other than environmental. We aimed at identifying efficient PubMed search filters for the study of environmental determinants of diseases related to outdoor air pollution. We compiled a list of Medical Subject Headings (MeSH) and non-MeSH terms seeming pertinent to outdoor air pollutants exposure as determinants of diseases in the general population. We estimated proportions of potentially pertinent articles to formulate two filters (one 'more specific', one 'more sensitive'). Their overall performance was evaluated as compared with our gold standard derived from systematic reviews on diseases potentially related to outdoor air pollution. We tested these filters in the study of three diseases potentially associated with outdoor air pollution and calculated the number of needed to read (NNR) abstracts to identify one potentially pertinent article in the context of these diseases. Last searches were run in January 2016. The 'more specific' filter was based on the combination of terms that yielded a threshold of potentially pertinent articles ≥40%. The 'more sensitive' filter was based on the combination of all search terms under study. When compared with the gold standard, the 'more specific' filter reported the highest specificity (67.4%; with a sensitivity of 82.5%), while the 'more sensitive' one reported the highest sensitivity (98.5%; with a specificity of 47.9%). The NNR to find one potentially pertinent article was 1.9 for the 'more specific' filter and 3.3 for the 'more sensitive' one. The proposed search filters could help healthcare professionals investigate environmental determinants of medical conditions that could be potentially related to outdoor air pollution. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Indications, complications and outcomes of elderly patients undergoing retrievable inferior vena cava filter placement.

PubMed

Rottenstreich, Amihai; Kleinstern, Geffen; Bloom, Allan I; Klimov, Alexander; Kalish, Yosef

2017-10-01

The utilization of inferior vena cava filter placement for pulmonary embolism prevention in elderly patients has not been well characterized. The present study aimed to review indications, complications and follow-up data of elderly patients undergoing inferior vena cava filter placement. A retrospective review was carried out of consecutive admitted patients who underwent inferior vena cava filter insertion at a large university hospital with a level I trauma center. Overall, 455 retrievable filters were inserted between 2009 and 2014. A total of 133 patients (29.2%) were aged ≥70 years. Elderly patients were less likely to have their filter retrieved compared with non-elderly patients (5.3% vs 21.4%, P < 0.001). Filter-related complications occurred in 13% of non-elderly patients and 14.3% of elderly patients (P = 0.72), most of them occurring in the first 3 months after filter placement. Survival among elderly patients with no evidence of active malignancy was similar to the non-elderly patients with a 1-year survival rate of 76.3% versus 82% in non-elderly patients (P = 0.22), and a 2-year survival rate of 73.1% versus 78.6% in non-elderly patients (P = 0.27). Although decreased, survival rates among elderly patients with active cancer were still substantial, with a 1-year survival rate of 45% and 2-year survival rate of 40%. Elderly patients had significantly lower rates of filter retrieval with similar complication rate. Survival rates among elderly patients were substantial, and in elderly patients with no active cancer were even comparable with non-elderly patients. When feasible, filter retrieval should be attempted in all elderly patients in order to prevent filter-related complications. Geriatr Gerontol Int 2017; 17: 1508-1514. © 2016 Japan Geriatrics Society.

Noise elimination method using a transmission line for the diagnostics of radio frequency plasma

NASA Astrophysics Data System (ADS)

Shimizu, K.; Hallil, A.; Amemiya, H.

1997-04-01

A filter using a transmission line formed by a cascade connection of inverted L-type networks has been developed to reject the distortion of the probe characteristics by rf (radio-frequency) noise. Each inverse L network consists of two coaxial cables with the same physical constant and length. The filter can remove discrete frequency components including the fundamental and harmonic components, the cut-off frequencies being determined by the distributed circuit constant and the length of the cables. By inserting different kinds of the network in cascade, many noise components associated with the rf frequency can be eliminated at the end section of the filter. Experiments have been performed in rf plasmas by inserting three kinds of inverted L networks with the frequency f (13.56 MHz), 2 f and 4f as the cut-off frequency. Distortion free probe characteristics have been obtained, from which accurate determination of plasma parameter such as the electron energy distribution is possible.

A randomized comparison of the i-gel with the self-pressurized air-Q intubating laryngeal airway in children.

PubMed

Kim, Min-Soo; Lee, Jae Hoon; Han, Sang Won; Im, Young Jae; Kang, Hyo Jong; Lee, Jeong-Rim

2015-04-01

Supraglottic airway devices with noninflatable cuff have advantages in omitting the cuff pressure monitoring and reducing potential pharyngolaryngeal complications. Typical devices without cuff inflation available in children are the i-gel and the self-pressurized air-Q intubating laryngeal airway (air-Q SP). To date, there is no comparative study between these devices in pediatric patients. The purpose of this randomized study was to compare the i-gel(™) and the self-pressurized air-Q(™) intubating laryngeal airway (air-Q SP) in children undergoing general anesthesia. Eighty children, 1-108 months of age, 7-30 kg of weight, and scheduled for elective surgery in which supraglottic airway devices would be suitable for airway management, were randomly assigned to either the i-gel or the air-Q SP. Oropharyngeal leak pressure and fiberoptic view were assessed three times as follows: after insertion and fixation of the device, 10 min after initial assessment, and after completion of surgery. We also assessed insertion parameters and complications. Insertion of the i-gel was regarded as significantly easier compared to the air-Q SP (P = 0.04). Compared to the air-Q SP group, the i-gel group had significantly higher oropharyngeal leak pressures at all measurement points and significantly lower frequencies of gastric insufflation at 10 min after initial assessment and completion of surgery. The air-Q SP group had better fiberoptic views than the i-gel group at all measurement points. Our results showed that the i-gel had easier insertion and better sealing function, and the air-Q SP provided improved fiberoptic views in children requiring general anesthesia. © 2015 John Wiley & Sons Ltd.

42 CFR 84.177 - Inhalation and exhalation valves; minimum requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... air from adversely affecting filters, except where filters are specifically designed to resist... DEVICES Non-Powered Air-Purifying Particulate Respirators § 84.177 Inhalation and exhalation valves... external influence; and (3) Designed and constructed to prevent inward leakage of contaminated air. ...

42 CFR 84.177 - Inhalation and exhalation valves; minimum requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... air from adversely affecting filters, except where filters are specifically designed to resist... DEVICES Non-Powered Air-Purifying Particulate Respirators § 84.177 Inhalation and exhalation valves... external influence; and (3) Designed and constructed to prevent inward leakage of contaminated air. ...

Stabilizing an optoelectronic microwave oscillator with photonic filters

NASA Technical Reports Server (NTRS)

Strekalov, D.; Aveline, D.; Yu, N.; Thompson, R.; Matsko, A. B.; Maleki, L.

2003-01-01

This paper compares methods of active stabilization of an optoelectronic microwave oscillator (OEO) based on insertion of a source of optical group delay into an OEO loop. The performance of an OEO stabilized with either a high- optical cavity or an atomic cell is analyzed. We show that the elements play a role of narrow-band microwave filters improving an OEO stability.

Ultra-wideband filtering of spoof surface plasmon polaritons using deep subwavelength planar structures

PubMed Central

Hu, Ming Zhe; Zhang, Hao Chi; Yin, Jia Yuan; Ding, Zhao; Liu, Jun Feng; Tang, Wen Xuan; Cui, Tie Jun

2016-01-01

Novel ultra-wideband filtering of spoof surface plasmon polaritons (SPPs) is proposed in the microwave frequency using deep subwavelength planar structures printed on thin and flexible dielectric substrate. The proposed planar SPPs waveguide is composed of two mirror-oriented metallic corrugated strips, which are further decorated with parallel-arranged slots in the main corrugated strips. This compound structure provides deep subwavelength field confinement as well as flexible parameters when employed as a plasmonic waveguide, which is potential to construct miniaturization. Using momentum and impedance matching technology, we achieve a smooth conversion between the proposed SPPs waveguide and the conventional transmission line. To verify the validity of the design, we fabricate a spoof SPPs filter, and the measured results illustrate excellent performance, in which the reflection coefficient is less than −10 dB within the −3 dB passband from 1.21 GHz to 7.21 GHz with the smallest insertion loss of 1.23 dB at 2.21 GHz, having very good agreements with numerical simulations. The ultra-wideband filter with low insertion loss and high transmission efficiency possesses great potential in modern communication systems. PMID:27883028

Ultra-wideband filtering of spoof surface plasmon polaritons using deep subwavelength planar structures.

PubMed

Hu, Ming Zhe; Zhang, Hao Chi; Yin, Jia Yuan; Ding, Zhao; Liu, Jun Feng; Tang, Wen Xuan; Cui, Tie Jun

2016-11-24

Novel ultra-wideband filtering of spoof surface plasmon polaritons (SPPs) is proposed in the microwave frequency using deep subwavelength planar structures printed on thin and flexible dielectric substrate. The proposed planar SPPs waveguide is composed of two mirror-oriented metallic corrugated strips, which are further decorated with parallel-arranged slots in the main corrugated strips. This compound structure provides deep subwavelength field confinement as well as flexible parameters when employed as a plasmonic waveguide, which is potential to construct miniaturization. Using momentum and impedance matching technology, we achieve a smooth conversion between the proposed SPPs waveguide and the conventional transmission line. To verify the validity of the design, we fabricate a spoof SPPs filter, and the measured results illustrate excellent performance, in which the reflection coefficient is less than -10 dB within the -3 dB passband from 1.21 GHz to 7.21 GHz with the smallest insertion loss of 1.23 dB at 2.21 GHz, having very good agreements with numerical simulations. The ultra-wideband filter with low insertion loss and high transmission efficiency possesses great potential in modern communication systems.

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR PREPARATION OF FILTERS AND PUF FOR FIELD COLLECTION OF METALS AND PESTICIDES IN AIR (BCO-L-2.0)

EPA Science Inventory

The purpose of this SOP is to describe the procedures for pre-cleaning filters and polyurethane foam (PUF) plug prior to air sampling with these media. The sampling media are used for sampling indoor air, outdoor air, and personal air. This procedure was followed to ensure consi...

A new technique for preliminary estimates of TRU activity on air sample filters and radiological smears.

PubMed

Hayes, Robert

2004-10-01

In most nuclear facilities, fixed air samplers and sometimes portable air samplers are used where some probability of a release exists but is not expected, and so the added expense and effort of using a continuous air monitor is not deemed justified. When a release is suspected, naturally occurring radioactive material buildup on the filter typically prevents any quantitative measurements within the first day or so. Likewise, outdoor air measurements suffer from the same limitations (such as those taken during the Los Alamos fires) and so any rapid quantifiable measurements of fixed air sampler/portable air sampler filters which are technically defendable (even though conservative) are of use. The technique presented here is only intended for use in routine health physics survey applications and does not presently appear to be appropriate for sub pico Curie activity determinations. This study evaluates the utility of using a portable continuous air monitor as an alpha spectrometer to make transuranic activity determinations of samples using both the built in algorithm for air monitoring and a simple region of interest analysis. All samples evaluated were from air sample filters taken using a portable air sampler. Samples were taken over many months to quantify effects from natural variation in radon progeny activity distributions.

Wavelength-tunable filter utilizing non-cyclic arrayed waveguide grating to create colorless, directionless, contentionless ROADMs

NASA Astrophysics Data System (ADS)

Niwa, Masaki; Takashina, Shoichi; Mori, Yojiro; Hasegawa, Hiroshi; Sato, Ken-ichi; Watanabe, Toshio

2015-01-01

With the continuous increase in Internet traffic, reconfigurable optical add-drop multiplexers (ROADMs) have been widely adopted in the core and metro core networks. Current ROADMs, however, allow only static operation. To realize future dynamic optical-network services, and to minimize any human intervention in network operation, the optical signal add/drop part should have colorless/directionless/contentionless (C/D/C) capabilities. This is possible with matrix switches or a combination of splitter-switches and optical tunable filters. The scale of the matrix switch increases with the square of the number of supported channels, and hence, the matrix-switch-based architecture is not suitable for creating future large-scale ROADMs. In contrast, the numbers of splitter ports, switches, and tunable filters increase linearly with the number of supported channels, and hence the tunable-filter-based architecture will support all future traffic. So far, we have succeeded in fabricating a compact tunable filter that consists of multi-stage cyclic arrayed-waveguide gratings (AWGs) and switches by using planar-lightwave-circuit (PLC) technologies. However, this multistage configuration suffers from large insertion loss and filter narrowing. Moreover, power-consuming temperature control is necessary since it is difficult to make cyclic AWGs athermal. We propose here novel tunable-filter architecture that sandwiches a single-stage non-cyclic athermal AWG having flatter-topped passbands between small-scale switches. With this configuration, the optical tunable filter attains low insertion loss, large passband bandwidths, low power consumption, compactness, and high cost-effectiveness. A prototype is monolithically fabricated with PLC technologies and its excellent performance is experimentally confirmed utilizing 80-channel 30-GBaud dual-polarization quadrature phase-shift-keying (QPSK) signals.

Effect of Intake Air Filter Condition on Vehicle Fuel Economy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norman, Kevin M; Huff, Shean P; West, Brian H

2009-02-01

The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy and the U.S. Environmental Protection Agency (EPA) jointly maintain a fuel economy website (www.fueleconomy.gov), which helps fulfill their responsibility under the Energy Policy Act of 1992 to provide accurate fuel economy information [in miles per gallon (mpg)] to consumers. The site provides information on EPA fuel economy ratings for passenger cars and light trucks from 1985 to the present and other relevant information related to energy use such as alternative fuels and driving and vehicle maintenance tips. In recent years, fluctuations in the price of crude oilmore » and corresponding fluctuations in the price of gasoline and diesel fuels have renewed interest in vehicle fuel economy in the United States. (User sessions on the fuel economy website exceeded 20 million in 2008 compared to less than 5 million in 2004 and less than 1 million in 2001.) As a result of this renewed interest and the age of some of the references cited in the tips section of the website, DOE authorized the Oak Ridge National Laboratory (ORNL) Fuels, Engines, and Emissions Research Center (FEERC) to initiate studies to validate and improve these tips. This report documents a study aimed specifically at the effect of engine air filter condition on fuel economy. The goal of this study was to explore the effects of a clogged air filter on the fuel economy of vehicles operating over prescribed test cycles. Three newer vehicles (a 2007 Buick Lucerne, a 2006 Dodge Charger, and a 2003 Toyota Camry) and an older carbureted vehicle were tested. Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in fuel economy with increasing restriction. However, the level of restriction required to cause a substantial (10-15%) decrease in fuel economy (such as that cited in the literature) was so severe that the vehicle was almost undrivable. Acceleration performance on all vehicles was improved with a clean air filter. Once it was determined how severe the restriction had to be to affect the carbureted vehicle fuel economy, the 2007 Buick Lucerne was retested in a similar manner. We were not able to achieve the level of restriction that was achieved with the 1972 Pontiac with the Lucerne. The Lucerne's air filter box would not hold the filter in place under such severe conditions. (It is believed that this testing exceeded the design limits of the air box.) Tests were conducted at a lower restriction level (although still considerably more severe than the initial clogged filter testing), allowing the air filter to stay seated in the air box, and no significant change was observed in the Lucerne's fuel economy or the AFR over the HFET cycle. Closed-loop control in modern fuel injected vehicle applications is sophisticated enough to keep a clogged air filter from affecting the vehicle fuel economy. However for older, open-loop, carbureted vehicles, a clogged air filter can affect the fuel economy. For the vehicle tested, the fuel economy with a new air filter improved as much as 14% over that with a severely clogged filter (in which the filter was so clogged that drivability was impacted). Under a more typical state of clog, the improvement with a new filter ranged from 2 to 6%.« less

The effect of ambient ozone and humidity on the performance of nylon and Teflon filters used in ambient air monitoring filter-pack systems

Treesearch

PE Padgett

2010-01-01

Nylon and Teflon filter media are frequently used for monitoring ambient air pollutants. These media are subject to many environmental factors that may influence adsorption and retention of particulate and gaseous nitrogenous pollutants. This study evaluated the effects of ozone and humidity on the efficacy of nylon and Teflon filters used in the US dry deposition...

Composition of the excimer laser-induced plume produced during LASIK refractive surgery

NASA Astrophysics Data System (ADS)

Glickman, Randolph D.; Liu, Yun; Mayo, George L.; Baribeau, Alan D.; Starck, Tomy; Bankhead, Tom

2003-07-01

Because of concerns about potential hazards to surgical personnel of the plume associated with laser refractive surgery, this study was performed to characterize the composition of such plumes. Filter elements were removed from the smoke evacuator of a VISX S3 excimer laser (filter pore size ~0.3 microns) and from a Mastel Clean Room ( filter pore size ~0.2 microns) used with a LADARVISION excimer laser. The filters from both laser systems captured the laser-induced plumes from multiple, routine, LASIK patient procedures. Some filters were processed for scanning electron microscopy, while others were extracted with methanol and chloroform for biochemical analysis. Both the VISX "Final Air" filter and the Mastel "Clean Room" filter captured material that was not observed in filters that had clean operating room air only passed through them. In the VISX system, air flows through the filter unit parallel to the filter matrix. SEM analysis showed these filters captured discrete particles of 0.3 to 3.0 microns in size. In the Mastel Clean Room unit, air flows orthogonally through the filter, and the filter matrix was heavily layered with captured debris so that individual particles were not readily distinguished. Amino acid analysis and gel electrophoresis of extracted material revealed proteinaceous molecules as large as 5000 molecular weight. Such large molecules in the laser plume are not predicted by the existing theory of photochemical ablation. The presence of relatively large biomolecules may constitute a risk of allergenic reactions in personnel exposed to the plume, and also calls into question the precise mechanism of excimer laser photochemical ablation. Supported by the RMG Research Endowment, and Research to Prevent Blindness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fisk, William J.; Destaillats, H.; Apte, M.G.

Heating, ventilating, and cooling classrooms in California consume substantial electrical energy. Indoor air quality (IAQ) in classrooms affects studenthealth and performance. In addition to airborne pollutants that are emitted directly by indoor sources and those generated outdoors, secondary pollutants can be formed indoors by chemical reaction of ozone with other chemicals and materials. Filters are used in nearly all classroom heating, ventilation and air?conditioning (HVAC) systems to maintain energy-efficient HVAC performance and improve indoor air quality; however, recent evidence indicates that ozone reactions with filters may, in fact, be a source of secondary pollutants. This project quantitatively evaluated ozone depositionmore » in HVAC filters and byproduct formation, and provided a preliminary assessment of the extent towhich filter systems are degrading indoor air quality. The preliminary information obtained will contribute to the design of subsequent research efforts and the identification of energy efficient solutions that improve indoor air quality in classrooms and the health and performance of students.« less

Breathing zone air sampler

DOEpatents

Tobin, John

1989-01-01

A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

40 CFR 63.11552 - What are my monitoring requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... filter for air leaks, torn or broken bags or filter media, or any other condition that may cause an...? 63.11552 Section 63.11552 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

40 CFR 63.11552 - What are my monitoring requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... filter for air leaks, torn or broken bags or filter media, or any other condition that may cause an...? 63.11552 Section 63.11552 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

40 CFR 63.11552 - What are my monitoring requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... filter for air leaks, torn or broken bags or filter media, or any other condition that may cause an...? 63.11552 Section 63.11552 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

40 CFR 63.11552 - What are my monitoring requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... filter for air leaks, torn or broken bags or filter media, or any other condition that may cause an...? 63.11552 Section 63.11552 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

Comparison of Gravity Wave Temperature Variances from Ray-Based Spectral Parameterization of Convective Gravity Wave Drag with AIRS Observations

NASA Technical Reports Server (NTRS)

Choi, Hyun-Joo; Chun, Hye-Yeong; Gong, Jie; Wu, Dong L.

2012-01-01

The realism of ray-based spectral parameterization of convective gravity wave drag, which considers the updated moving speed of the convective source and multiple wave propagation directions, is tested against the Atmospheric Infrared Sounder (AIRS) onboard the Aqua satellite. Offline parameterization calculations are performed using the global reanalysis data for January and July 2005, and gravity wave temperature variances (GWTVs) are calculated at z = 2.5 hPa (unfiltered GWTV). AIRS-filtered GWTV, which is directly compared with AIRS, is calculated by applying the AIRS visibility function to the unfiltered GWTV. A comparison between the parameterization calculations and AIRS observations shows that the spatial distribution of the AIRS-filtered GWTV agrees well with that of the AIRS GWTV. However, the magnitude of the AIRS-filtered GWTV is smaller than that of the AIRS GWTV. When an additional cloud top gravity wave momentum flux spectrum with longer horizontal wavelength components that were obtained from the mesoscale simulations is included in the parameterization, both the magnitude and spatial distribution of the AIRS-filtered GWTVs from the parameterization are in good agreement with those of the AIRS GWTVs. The AIRS GWTV can be reproduced reasonably well by the parameterization not only with multiple wave propagation directions but also with two wave propagation directions of 45 degrees (northeast-southwest) and 135 degrees (northwest-southeast), which are optimally chosen for computational efficiency.

Performance Enhancement of Tunable Bandpass Filters Using Selective Etched Ferroelectric Thin Films

NASA Technical Reports Server (NTRS)

Miranda, Felix A.; Mueller, Carl H.; VanKeuls, Fred W.; Subramanyam, Guru; Vignesparamoorthy, Sivaruban

2003-01-01

The inclusion of voltage-tunable barium strontium titanate (BSTO) thin films into planar band pass filters offers tremendous potential to increase their versatility. The ability to tune the passband so as to correct for minor deviations in manufacturing tolerances, or to completely reconfigure the operating frequencies of a microwave communication system, are highly sought-after goals. However, use of ferroelectric films in these devices results in higher dielectric losses, which in turn increase the insertion loss and decrease the quality factors of the filters. This study explores the use of patterned ferroelectric layers to minimize dielectric losses without degrading tunability. Patterning the ferroelectric layers enables us to constrict the width of the ferroelectric layers between the coupled microstrip lines, and minimize losses due to ferroelectric layers. Coupled one-pole microstrip bandpass filters with fundamental resonances at approx. 7.2 GHz and well defined harmonic resonances at approx. 14.4 and approx. 21.6 GHz, were designed, simulated and tested. For one of the filters, experimental results verified that its center frequency was tunable by 528 MHz at a center frequency of 21.957 GHz, with insertion losses varying from 4.3 to 2.5 dB, at 0 and 3.5 V/micron, respectively. These data demonstrate that the tuning-to-loss figure of merit of tunable microstrip filters can be greatly improved using patterned ferroelectric thin films as the tuning element, and tuning can be controlled by engineering the ferroelectric constriction in the coupled sections.

Determination of polybrominated diphenyl ethers (PBDEs) in dust samples collected in air conditioning filters of different usage - method development.

PubMed

Śmiełowska, M; Zabiegała, B

2018-06-19

This study presents the results of studies aimed at the development of an analytical procedure for separation, identification, and determination of PBDEs compounds in dust samples collected from automotive cabin air filters and samples collected from filters installed as part of the air purification system in academic facilities. Ultrasound-assisted dispersive solid phase extraction (UA-dSPE) was found to perform better in terms of extract purification than the conventional SPE technique. GC-EIMS was used for final determination of analytes. The concentrations of PBDEs in car filters ranged from < LOD to 688 ng/g while from < LOD to 247 ng/g in dust from air conditioning filters. BDE-47 and BDE-100 were reported the dominating congeners. The estimated exposure to PBDEs via ingestion of dust from car filters varied from 0.00022 to 0.012 ng/day in toddlers and from 0.000036 to 0.0029 ng/day in adults; dust from air conditioning filters: from 0.017 to 0.25 ng/day in toddlers and from 0.0029 to 0.042 ng/day. In addition, an attempt was made at extracting PBDEs from a dust samples using the matrix solid-phase dispersion (MSPD) technique as a promising alternative to conventional SPE separations. Copyright © 2018 Elsevier B.V. All rights reserved.

Method for contamination control and barrier apparatus with filter for containing waste materials that include dangerous particulate matter

DOEpatents

Pinson, Paul A.

1998-01-01

A container for hazardous waste materials that includes air or other gas carrying dangerous particulate matter has incorporated in barrier material, preferably in the form of a flexible sheet, one or more filters for the dangerous particulate matter sealably attached to such barrier material. The filter is preferably a HEPA type filter and is preferably chemically bonded to the barrier materials. The filter or filters are preferably flexibly bonded to the barrier material marginally and peripherally of the filter or marginally and peripherally of air or other gas outlet openings in the barrier material, which may be a plastic bag. The filter may be provided with a backing panel of barrier material having an opening or openings for the passage of air or other gas into the filter or filters. Such backing panel is bonded marginally and peripherally thereof to the barrier material or to both it and the filter or filters. A coupling or couplings for deflating and inflating the container may be incorporated. Confining a hazardous waste material in such a container, rapidly deflating the container and disposing of the container, constitutes one aspect of the method of the invention. The chemical bonding procedure for producing the container constitutes another aspect of the method of the invention.

Method for contamination control and barrier apparatus with filter for containing waste materials that include dangerous particulate matter

DOEpatents

Pinson, P.A.

1998-02-24

A container for hazardous waste materials that includes air or other gas carrying dangerous particulate matter has incorporated barrier material, preferably in the form of a flexible sheet, and one or more filters for the dangerous particulate matter sealably attached to such barrier material. The filter is preferably a HEPA type filter and is preferably chemically bonded to the barrier materials. The filter or filters are preferably flexibly bonded to the barrier material marginally and peripherally of the filter or marginally and peripherally of air or other gas outlet openings in the barrier material, which may be a plastic bag. The filter may be provided with a backing panel of barrier material having an opening or openings for the passage of air or other gas into the filter or filters. Such backing panel is bonded marginally and peripherally thereof to the barrier material or to both it and the filter or filters. A coupling or couplings for deflating and inflating the container may be incorporated. Confining a hazardous waste material in such a container, rapidly deflating the container and disposing of the container, constitutes one aspect of the method of the invention. The chemical bonding procedure for producing the container constitutes another aspect of the method of the invention. 3 figs.

Advanced hybrid particulate collector and method of operation

DOEpatents

Miller, Stanley J.

1999-01-01

A device and method for controlling particulate air pollutants of the present invention combines filtration and electrostatic collection devices. The invention includes a chamber housing a plurality of rows of filter elements. Between each row of filter elements is a grounded plate. Between the grounded plates and the filter elements are electrode grids for creating electrostatic precipitation zones between each row of filter elements. In this way, when the filter elements are cleaned by pulsing air in a reverse direction, the dust removed from the bags will collect in the electrostatic precipitation zones rather than on adjacent filter elements.

Advanced hybrid particulate collector and method of operation

DOEpatents

Miller, S.J.

1999-08-17

A device and method for controlling particulate air pollutants of the present invention combines filtration and electrostatic collection devices. The invention includes a chamber housing a plurality of rows of filter elements. Between each row of filter elements is a grounded plate. Between the grounded plates and the filter elements are electrode grids for creating electrostatic precipitation zones between each row of filter elements. In this way, when the filter elements are cleaned by pulsing air in a reverse direction, the dust removed from the bags will collect in the electrostatic precipitation zones rather than on adjacent filter elements. 12 figs.

Calculation of airborne radioactivity in a Technegas lung ventilation unit.

PubMed

López Medina, A; Miñano, J A; Terrón, J A; Bullejos, J A; Guerrero, R; Arroyo, T; Ramírez, A; Llamas, J M

1999-12-01

Airborne contamination by 99Tcm has been monitored in the Nuclear Medicine Department in our hospital to assess the risk of internal contamination to occupational workers exposed to Technegas studies. An air sampler fitted with a membrane filter was used. The optimum time for air absorption for obtaining the maximum activity in the filter was calculated. Maximum activity in the membrane filter ensures minimum uncertainty, which is especially important when low-level activities are being measured. The optimum time depends on air absorption velocity, room volume and filter efficiency for isotope collection. It tends to 1/lambda (lambda = disintegration constant for 99Tcm) for large volume and low velocity. Room activity with the air pump switched on was related to filter activity, and its variation with time was studied. Free activity in air for each study was approximately 7 x 10(-4) the activity used, and the effective half-life of the isotope in the room was 13.9 min (decay and diffusion). For a typical study (630 MBq), the effective dose to staff was 0.01 microSv when in the room for 10 min.

Detection of viruses in used ventilation filters from two large public buildings.

PubMed

Goyal, Sagar M; Anantharaman, Senthilvelan; Ramakrishnan, M A; Sajja, Suchitra; Kim, Seung Won; Stanley, Nicholas J; Farnsworth, James E; Kuehn, Thomas H; Raynor, Peter C

2011-09-01

Viral and bacterial pathogens may be present in the air after being released from infected individuals and animals. Filters are installed in the heating, ventilation, and air-conditioning (HVAC) systems of buildings to protect ventilation equipment and maintain healthy indoor air quality. These filters process enormous volumes of air. This study was undertaken to determine the utility of sampling used ventilation filters to assess the types and concentrations of virus aerosols present in buildings. The HVAC filters from 2 large public buildings in Minneapolis and Seattle were sampled to determine the presence of human respiratory viruses and viruses with bioterrorism potential. Four air-handling units were selected from each building, and a total of 64 prefilters and final filters were tested for the presence of influenza A, influenza B, respiratory syncytial, corona, parainfluenza 1-3, adeno, orthopox, entero, Ebola, Marburg, Lassa fever, Machupo, eastern equine encephalitis, western equine encephalitis, and Venezuelan equine encephalitis viruses. Representative pieces of each filter were cut and eluted with a buffer solution. Attempts were made to detect viruses by inoculation of these eluates in cell cultures (Vero, MDCK, and RK-13) and specific pathogen-free embryonated chicken eggs. Two passages of eluates in cell cultures or these eggs did not reveal the presence of any live virus. The eluates were also examined by polymerase chain reaction or reverse-transcription polymerase chain reaction to detect the presence of viral DNA or RNA, respectively. Nine of the 64 filters tested were positive for influenza A virus, 2 filters were positive for influenza B virus, and 1 filter was positive for parainfluenza virus 1. These findings indicate that existing building HVAC filters may be used as a method of detection for airborne viruses. As integrated long-term bioaerosol sampling devices, they may yield valuable information on the epidemiology and aerobiology of viruses in air that can inform the development of methods to prevent airborne transmission of viruses and possible deterrents against the spread of bioterrorism agents. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

40 CFR 86.145-82 - Calculations; particulate emissions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., inside the dilution air filter box at EPA is very low. Pb will be assumed = 0, and background particulate.... 86.145-82 Section 86.145-82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... further defined in § 86.144. (3) P e = mass of particulate per test on the exhaust filter(s), grams. (4...

40 CFR 86.145-82 - Calculations; particulate emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., inside the dilution air filter box at EPA is very low. Pb will be assumed = 0, and background particulate.... 86.145-82 Section 86.145-82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... further defined in § 86.144. (3) P e = mass of particulate per test on the exhaust filter(s), grams. (4...

77 FR 32632 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-01

... Hydrogen Peroxide Filter Extraction'' In this method, total suspended particulate matter (TSP) is collected on glass fiber filters according to 40 CFR Appendix G to part 50, EPA Reference Method for the Determination of Lead in Suspended Particulate Matter Collected From Ambient Air. The filter samples are...

76 FR 74708 - National Emission Standards for Hazardous Air Pollutants for Source Categories

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-01

... as follows: Bag leak detection system means a monitoring device for a fabric filter that identifies an increase in particulate matter emissions resulting from a broken filter bag or other malfunction... thermoset a binder on the mineral wool fiber used to make bonded products. Fabric filter means an air...

[Gohieria fusca found in dust of air-conditioner filters].

PubMed

Qiang, Chai; Xiao-Dong, Zhan; Wei, Guo; Chao-Pin, Li

2017-09-25

To investigate the pollution status of Gohieria fusca in the air conditioner-filters of different places in Wuhu City. The dust samples were collected from the filters of air-conditioners in dining rooms, shopping malls, hotels and households between June and September, 2013, and G. fusca was detected in the dust samples. There were 430 dust samples collected and 98 were G. fusca positive with the breeding rate of 22.79%. The difference of breeding rates of G. fusca were statistically significant among the different places ( χ 2 =18.294, P < 0.05). Among 510.5 g dust samples in total, 783 G. fusca mites were detected with an average breeding density of 1.53 mite/g. G. fusca breeds in the dust of air-conditioner filters in Wuhu City gravely.

Air filtration systems and restrictive access conditions improve indoor air quality in clinical units: Penicillium as a general indicator of hospital indoor fungal levels.

PubMed

Araujo, Ricardo; Cabral, João Paulo; Rodrigues, Acácio Gonçalves

2008-03-01

High-efficiency particulate air (HEPA) filters do not completely prevent nosocomial fungal infections. The first aim of this study was to evaluate the impact of different filters and access conditions upon airborne fungi in hospital facilities. Additionally, this study identified fungal indicators of indoor air concentrations. Eighteen rooms and wards equipped with different air filter systems, and access conditions were sampled weekly, during 16 weeks. Tap water samples were simultaneously collected. The overall mean concentration of atmospheric fungi for all wards was 100 colony forming units/m(3). We found a direct proportionality between the levels of the different fungi in the studied atmospheres. Wards with HEPA filters at positive air flow yielded lower fungal levels. Also, the existence of an anteroom and the use of protective clothes were associated to the lowest fungal levels. Principal component analysis showed that penicillia afforded the best separation between wards' air fungal levels. Fungal strains were rarely recovered from tap water samples. In addition to air filtration systems, some access conditions to hospital units, like presence of anteroom and use of protective clothes, may prevent high fungal air load. Penicillia can be used as a general indicator of indoor air fungal levels at Hospital S. João.

17. VIEW OF AIR LOCK ENTRY DOOR. BANKS OF AIR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. VIEW OF AIR LOCK ENTRY DOOR. BANKS OF AIR FILTERS ARE VISIBLE TO THE SIDES OF THE DOORS. THE BUILDING WAS DIVIDED INTO ZONES BY AIRLOCK DOORS AND AIR FILTERS. AIR PRESSURE DIFFERENTIALS WERE MAINTAINED IN THE ZONES, SUCH THAT AIRFLOW WAS PROGRESSIVELY TOWARD AREAS WITH THE HIGHEST POTENTIAL FOR CONTAMINATION. (9/24/91) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

Effects of piston surface treatments on performance and emissions of a methanol-fueled, direct injection, stratified charge engine

NASA Astrophysics Data System (ADS)

West, B.; Green, J. B.

1994-07-01

The purpose of this study was to investigate the effects of thermal barrier coatings and/or surface treatments on the performance and emissions of a methanol-fueled, direct-injection, stratified-charge (DISC) engine. A Ricardo Hydra Mark III engine was used for this work and in previous experiments at Oak Ridge National Laboratory (ORNL). The primary focus of the study was to examine the effects of various piston insert surface treatments on hydrocarbon (HC) and oxides of nitrogen (NO(x)) emissions. Previous studies have shown that engines of this class have a tendency to perform poorly at low loads and have high unburned fuel emissions. A blank aluminum piston was modified to employ removable piston bowl inserts. Four different inserts were tested in the experiment: aluminum, stainless steel with a 1.27-mm (0.050-in.) air gap (to act as a thermal barrier), and two stainless steel/air-gap inserts with coatings. Two stainless steel inserts were dimensionally modified to account for the coating thickness (1.27-mm) and coated identically with partially stabilized zirconia (PSZ). One of the coated inserts then had an additional seal-coat applied. The coated inserts were otherwise identical to the stainless steel/air-gap insert (i.e., they employed the same 1.27-mm air gap). Thermal barrier coatings were employed in an attempt to increase combustion chamber surface temperatures, thereby reducing wall quenching and promoting more complete combustion of the fuel in the quench zone. The seal-coat was applied to the zirconia to reduce the surface porosity; previous research suggested that despite the possibly higher surface temperatures obtainable with a ceramic coating, the high surface area of a plasma-sprayed coating may actually allow fuel to adhere to the surface and increase the unburned fuel emissions and fuel consumption.

Aspergillus prevalence in air conditioning filters from vehicles: taxis for patient transportation, forklifts, and personal vehicles.

PubMed

Viegas, Carla; Moreira, Ricardo; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Gomes, Anita Quintal; Viegas, Susana

2018-05-04

The frequency and importance of Aspergillus infections is increasing worldwide. This study aimed to assess the occupational exposure of forklifts and taxi drivers to Aspergillus spp. Nineteen filters from air conditioning system of taxis, 17 from forklifts and 37 from personal vehicles were assessed. Filters extract were streaked onto MEA, DG18 and in azole-supplemented media. Real-time quantitative PCR amplification of selected Aspergillus species-complex was also performed. Forklifts filter samples presented higher median values. Aspergillus section Nigri was the most observed in forklifts filters in MEA (28.2%) and in azole-supplemented media. DNA from Aspergillus sections Fumigati and Versicolores was successfully amplified by qPCR. This study enlightens the added value of using filters from the air conditioning system to assess Aspergillus spp. occupational exposure. Aspergillus azole resistance screening should be included in future occupational exposure assessments.

Palladium-103 plaque radiation therapy for ciliary body melanoma through a functioning glaucoma filtering bleb.

PubMed

Pathan, Arif H K; Barash, Alexander; Tena, Lawrence B; Finger, Paul T

2018-01-01

To provide a clinical description of the long-term outcome of a 103 Pd plaque-irradiated ciliary body melanoma with extrascleral extension while attempting to preserve a subadjacent glaucoma filtering bleb. A 75-year-old woman with pseudoexfoliative glaucoma for 17 years, 16 years status post argon laser trabeculoplasty, and 15 years status post trabeculectomy in the left eye, was diagnosed with an ipsilateral ciliary body melanoma with visible extrascleral extension. Treatment involved insertion of a 103 Pd radioactive plaque over the functioning trabeculectomy, with removal 7 days later. At plaque insertion, amniotic membrane grafts were used to cover the plaque and protect the filtering site. The tumor was successfully treated without clinical evidence of harm to the filtering bleb, with resultant stable intraocular pressure. However, the patient developed blebitis 1.5 years later. Though it resolved with topical antibiotic therapy, the bleb became less succulent. Two years postoperatively, she developed a spontaneous hyphema that resolved after one injection of transscleral bevacizumab 1.25 mg. Her tumor continually regressed in thickness. Without additional glaucoma surgery, her intraocular pressure remained well-controlled on topical medications for 6 years. Ciliary body melanoma with minimal extrascleral extension beneath a functioning filtering bleb can be treated using radioactive plaque therapy. In this case, we were able to achieve both tumor regression and glaucoma control by covering the plaque with an amniotic membrane graft.

Room air monitor for radioactive aerosols

DOEpatents

Balmer, David K.; Tyree, William H.

1989-04-11

A housing assembly for use with a room air monitor for simultaneous collection and counting of suspended particles includes a casing containing a combination detector-preamplifier system at one end, a filter system at the other end, and an air flow system consisting of an air inlet formed in the casing between the detector-preamplifier system and the filter system and an air passageway extending from the air inlet through the casing and out the end opposite the detector-preamplifier combination. The filter system collects suspended particles transported directly through the housing by means of the air flow system, and these particles are detected and examined for radioactivity by the detector-pre The U.S. Government has rights in this invention pursuant to Contract No. DE-AC04-76DP03533 between the Department of Energy and Rockwell International Corporation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, T; Graham, C L; Sundsmo, T

This procedure provides instructions for the calibration and use of the Canberra iSolo Low Background Alpha/Beta Counting System (iSolo) that is used for counting air filters and swipe samples. This detector is capable of providing radioisotope identification (e.g., it can discriminate between radon daughters and plutonium). This procedure includes step-by-step instructions for: (1) Performing periodic or daily 'Background' and 'Efficiency QC' checks; (2) Setting-up the iSolo for counting swipes and air filters; (3) Counting swipes and air filters for alpha and beta activity; and (4) Annual calibration.

Over 10,000 new maize mutants added to the uniformMu public resource: now 67,000 total Mu insertions with 42% genome coverage

USDA-ARS?s Scientific Manuscript database

Over 10,000 new mutants have been added to the UniformMu reverse genetics resource in release 7, bringing the total to over 67,000 germinal transposon insertions. These are available in 11,140 independent seed stocks. Close to half of the maize filtered gene set (42%) is represented by at least one ...

Testing Air-Filtering Systems

PubMed Central

Songer, Joseph R.; Sullivan, James F.; Hurd, James W.

1963-01-01

A procedure was developed for evaluating high-efficiency filters mounted in exhaust ducts at the National Animal Disease Laboratory. An aerosol of the test organism, Escherichia coli B T3 bacteriophage, was generated in a chamber attached to a ceiling exhaust register in concentrations of at least 1000 viable organisms per ft3 of air. Samples were collected from both the pre- and postfilter areas, and the number of organisms per ft3 of air was determined. The efficiency of the filter was calculated from these figures. A total of 269 high-efficiency filters were tested. Of these, 249 had efficiencies of 98% or greater. The remaining 20, with efficiencies of less than 98%, were repaired and retested. No filter was accepted with an efficiency of less than 98%. Images Fig. 2 PMID:14063779

Washable antimicrobial polyester/aluminum air filter with a high capture efficiency and low pressure drop.

PubMed

Choi, Dong Yun; Heo, Ki Joon; Kang, Juhee; An, Eun Jeong; Jung, Soo-Ho; Lee, Byung Uk; Lee, Hye Moon; Jung, Jae Hee

2018-06-05

Here, we introduce a reusable bifunctional polyester/aluminum (PET/Al) air filter for the high efficiency simultaneous capture and inactivation of airborne microorganisms. Both bacteria of Escherichia coli and Staphylococcus epidermidis were collected on the PET/Al filter with a high efficiency rate (∼99.99%) via the electrostatic interactions between the charged bacteria and fibers without sacrificing pressure drop. The PET/Al filter experienced a pressure drop approximately 10 times lower per thickness compared with a commercial high-efficiency particulate air filter. As the Al nanograins grew on the fibers, the antimicrobial activity against airborne E. coli and S. epidermidis improved to ∼94.8% and ∼96.9%, respectively, due to the reinforced hydrophobicity and surface roughness of the filter. Moreover, the capture and antimicrobial performances were stably maintained during a cyclic washing test of the PET/Al filter, indicative of its reusability. The PET/Al filter shows great potential for use in energy-efficient bioaerosol control systems suitable for indoor environments. Copyright © 2018 Elsevier B.V. All rights reserved.

Enhancing indoor air quality –The air filter advantage

PubMed Central

Vijayan, Vannan Kandi; Paramesh, Haralappa; Salvi, Sundeep Santosh; Dalal, Alpa Anil Kumar

2015-01-01

Air pollution has become the world's single biggest environmental health risk, linked to around 7 million deaths in 2012 according to a recent World Health Organisation (WHO) report. The new data further reveals a stronger link between, indoor and outdoor air pollution exposure and cardiovascular diseases, such as strokes and ischemic heart disease, as well as between air pollution and cancer. The role of air pollution in the development of respiratory diseases, including acute respiratory infections and chronic obstructive pulmonary diseases, is well known. While both indoor and outdoor pollution affect health, recent statistics on the impact of household indoor pollutants (HAP) is alarming. The WHO factsheet on HAP and health states that 3.8 million premature deaths annually - including stroke, ischemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer are attributed to exposure to household air pollution. Use of air cleaners and filters are one of the suggested strategies to improve indoor air quality. This review discusses the impact of air pollutants with special focus on indoor air pollutants and the benefits of air filters in improving indoor air quality. PMID:26628762

Enhancing indoor air quality -The air filter advantage.

PubMed

Vijayan, Vannan Kandi; Paramesh, Haralappa; Salvi, Sundeep Santosh; Dalal, Alpa Anil Kumar

2015-01-01

Air pollution has become the world's single biggest environmental health risk, linked to around 7 million deaths in 2012 according to a recent World Health Organisation (WHO) report. The new data further reveals a stronger link between, indoor and outdoor air pollution exposure and cardiovascular diseases, such as strokes and ischemic heart disease, as well as between air pollution and cancer. The role of air pollution in the development of respiratory diseases, including acute respiratory infections and chronic obstructive pulmonary diseases, is well known. While both indoor and outdoor pollution affect health, recent statistics on the impact of household indoor pollutants (HAP) is alarming. The WHO factsheet on HAP and health states that 3.8 million premature deaths annually - including stroke, ischemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer are attributed to exposure to household air pollution. Use of air cleaners and filters are one of the suggested strategies to improve indoor air quality. This review discusses the impact of air pollutants with special focus on indoor air pollutants and the benefits of air filters in improving indoor air quality.

Towards Polarised Antiprotons: Machine Developments for Spin-Filtering Studies

NASA Astrophysics Data System (ADS)

Lenisa, Paolo

2016-02-01

We address the commissioning of the experimental equipment and the machine studies required for the first spin-filtering experiment with protons at the COSY ring in Jülich (Germany) at a beam kinetic energy of 49.3 MeV. The implementation of a low-beta insertion made it possible to achieve beam lifetimes of 8000 s in the presence of a dense polarized hydrogen storage cell target. The developed techniques can be directly applied to antiproton machines and allow for the determination of the spin-dependent pbar-p cross sections via spin-filtering.

Highly-Effective Purification of Air on the Fibrous Filtering Nozzles

NASA Astrophysics Data System (ADS)

Galtseva, O. V.; Bordunov, S. V.; Torgaev, S. N.

2016-02-01

A series of experiments by air purification on fibrous filtering nozzles was made. It is experimentally shown that the fibrous filter can operate in a wide rate range. The degree of trapping of fine aerosols of glass was 99% at a linear rate of 0.01 m/s. the degree of capture decreased to 85% at the increasing of filtration rate up to 0.06 m/s. Dustiness of the air ranged from 3 to 5 g/m3 at the course of the experiment. Hydraulic resistance changed from 5 to 25 mm of water column. The calculated data of resistance and falling of pressure on fibrous filters are given; these data were received on the equations from various sources in comparison with experimentally obtained data. According to the results of series of experiments the amendment of the well-known Fuchsian equation is calculated for calculation of the resistance of fibrous air filter. This amendment considers a form and defects of surface of the fibers received by centrifugal-spinneret method.

Stay away from asthma triggers

MedlinePlus

... cleaner with a HEPA (high-efficiency particulate arrestor) filter. Replace wall-to-wall carpet with wood or ... a central air conditioning system, use a HEPA filter to remove pet allergens from indoor air. Use ...

Effect of High-Pass Filtering on the Neonatal Auditory Brainstem Response to Air- and Bone-Conducted Clicks.

ERIC Educational Resources Information Center

Stuart, Andrew; Yang, Edward Y.

1994-01-01

Simultaneous 3- channel recorded auditory brainstem responses (ABR) were obtained from 20 neonates with various high-pass filter settings and low intensity levels. Results support the advocacy of less restrictive high-pass filtering for neonatal and infant ABR screening to air-conducted and bone-conducted clicks. (Author/JDD)

40 CFR 721.10583 - Benzenamine, 4,4′-[1,3-phenylenebis(1-methylethylidene)]bis-.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., tight-fitting half-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters... aerosols absent), R100, or P100 filters. (C) NIOSH-certified powered air-purifying respirator equipped with a loose-fitting hood or helmet and high efficiency particulate air (HEPA) filters. (D) NIOSH...

40 CFR 721.10583 - Benzenamine, 4,4′-[1,3-phenylenebis(1-methylethylidene)]bis-.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., tight-fitting half-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters... aerosols absent), R100, or P100 filters. (C) NIOSH-certified powered air-purifying respirator equipped with a loose-fitting hood or helmet and high efficiency particulate air (HEPA) filters. (D) NIOSH...

Design and Simulation of Microstrip Hairpin Bandpass Filter with Open Stub and Defected Ground Structure (DGS) at X-Band Frequency

NASA Astrophysics Data System (ADS)

Hariyadi, T.; Mulyasari, S.; Mukhidin

2018-02-01

In this paper we have designed and simulated a Band Pass Filter (BPF) at X-band frequency. This filter is designed for X-band weather radar application with 9500 MHz center frequency and bandwidth -3 dB is 120 MHz. The filter design was performed using a hairpin microstrip combined with an open stub and defected ground structure (DGS). The substrate used is Rogers RT5880 with a dielectric constant of 2.2 and a thickness of 1.575 mm. Based on the simulation results, it is found that the filter works on frequency 9,44 - 9,56 GHz with insertion loss value at pass band is -1,57 dB.

Evaluation of the Long-Term Effect of Air Filtration on the Occurrence of New PRRSV Infections in Large Breeding Herds in Swine-Dense Regions

PubMed Central

Dee, Scott; Cano, Jean Paul; Spronk, Gordon; Reicks, Darwin; Ruen, Paul; Pitkin, Andrea; Polson, Dale

2012-01-01

Airborne transmission of porcine reproductive and respiratory syndrome virus (PRRSV) is a risk factor for the infection of susceptible populations. Therefore, a long‑term sustainability study of air filtration as a means to reduce this risk was conducted. Participating herds (n = 38) were organized into 4 independent cohorts and the effect of air filtration on the occurrence of new PRRSV infections was analyzed at 3 different levels from September 2008 to January 2012 including the likelihood of infection in contemporary filtered and non-filtered herds, the likelihood of infection before and after implementation of filtration and the time to failure in filtered and non-filtered herds. Results indicated that new PRRSV infections in filtered breeding herds were significantly lower than in contemporary non-filtered control herds (P < 0.01), the odds for a new PRRSV infection in breeding herds before filtration was 7.97 times higher than the odds after filtration was initiated (P < 0.01) and the median time to new PRRSV infections in filtered breeding herds of 30 months was significantly longer than the 11 months observed in non-filtered herds (P < 0.01). In conclusion, across all 3 levels of analysis, the long-term effect of air filtration on reducing the occurrence of new PRRSV infections in the study population was demonstrated. PMID:22754642

Humidifiers: Air Moisture Eases Skin, Breathing Symptoms

MedlinePlus

... fan to blow air through a wet wick, filter or belt. Steam vaporizers use electricity to create ... help dry out damp basements. Dirty reservoirs and filters in humidifiers can quickly breed bacteria and mold. ...

The influence of reaction time on hydrogen sulphide removal from air by means of Fe(III)-EDTA/Fiban catalysts

NASA Astrophysics Data System (ADS)

Wasag, H.; Cel, W.; Chomczynska, M.; Kujawska, J.

2018-05-01

The paper deals with a new method of hydrogen sulphide removal from air by its filtration and selective catalytic oxidation with the use of fibrous carriers of Fe(III)-EDTA complex. The basis of these filtering materials includes fibrous ion exchangers with the complex immobilized on their functional groups. It has been established that the degree of catalytic hydrogen sulphide decomposition depends on the reaction time. Thus, the required degree of hydrogen sulphide removal from air could be easily controlled by applying appropriate thickness of the filtering layer under a given filtering velocity. It allows applying very thin filtering layers of the Fe(III)-EDTA/Fiban AK-22 or Fiban A-6 catalysts. The obtained results of the research confirm the applicability of these materials for deep air purification from hydrogen sulphide.

Molecular comparison of the sampling efficiency of four types of airborne bacterial samplers.

PubMed

Li, Kejun

2011-11-15

In the present study, indoor and outdoor air samples were collected using four types of air samplers often used for airborne bacterial sampling. These air samplers included two solid impactors (BioStage and RCS), one liquid impinger (BioSampler), and one filter sampler with two kinds of filters (a gelatin and a cellulose acetate filter). The collected air samples were further processed to analyze the diversity and abundance of culturable bacteria and total bacteria through standard culture techniques, denaturing gradient gel electrophoresis (DGGE) fingerprinting and quantitative polymerase chain reaction (qPCR) analysis. The DGGE analysis indicated that the air samples collected using the BioStage and RCS samplers have higher culturable bacterial diversity, whereas the samples collected using the BioSampler and the cellulose acetate filter sampler have higher total bacterial diversity. To obtain more information on the sampled bacteria, some gel bands were excised and sequenced. In terms of sampling efficiency, results from the qPCR tests indicated that the collected total bacterial concentration was higher in samples collected using the BioSampler and the cellulose acetate filter sampler. In conclusion, the sampling bias and efficiency of four kinds of air sampling systems were compared in the present study and the two solid impactors were concluded to be comparatively efficient for culturable bacterial sampling, whereas the liquid impactor and the cellulose acetate filter sampler were efficient for total bacterial sampling. Copyright © 2011 Elsevier B.V. All rights reserved.

Effects of photochemical smog on lemons and navel oranges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, C.R.; Taylor, O.C.; Richards, B.L.

1970-05-01

Experiments were carried out on lemon and Navel orange trees to determine the kind and extent of damage caused by air pollution in the Los Angeles Basin. Trees were enclosed in filter-equipped greenhouses and compared with control trees which were exposed to ambient air. Yield of lemons was about one third more in filtered trees, and with oranges, the yield was about doubled. Fruit drop in oranges was a major problem associated with the exposure to ambient air pollution. Trees in ambient air were reduced in photosynthesis to 66% of filtered-air treatments. Fluoride, while present in the atmosphere was ofmore » minor importance to the health and performance of the trees. 2 tables.« less

High-energy metal air batteries

DOEpatents

Zhang, Ji-Guang; Xiao, Jie; Xu, Wu; Wang, Deyu; Williford, Ralph E.; Liu, Jun

2014-07-01

Disclosed herein are embodiments of lithium/air batteries and methods of making and using the same. Certain embodiments are pouch-cell batteries encased within an oxygen-permeable membrane packaging material that is less than 2% of the total battery weight. Some embodiments include a hybrid air electrode comprising carbon and an ion insertion material, wherein the mass ratio of ion insertion material to carbon is 0.2 to 0.8. The air electrode may include hydrophobic, porous fibers. In particular embodiments, the air electrode is soaked with an electrolyte comprising one or more solvents including dimethyl ether, and the dimethyl ether subsequently is evacuated from the soaked electrode. In other embodiments, the electrolyte comprises 10-20% crown ether by weight.

High-energy metal air batteries

DOEpatents

Zhang, Ji-Guang; Xiao, Jie; Xu, Wu; Wang, Deyu; Williford, Ralph E.; Liu, Jun

2013-07-09

Disclosed herein are embodiments of lithium/air batteries and methods of making and using the same. Certain embodiments are pouch-cell batteries encased within an oxygen-permeable membrane packaging material that is less than 2% of the total battery weight. Some embodiments include a hybrid air electrode comprising carbon and an ion insertion material, wherein the mass ratio of ion insertion material to carbon is 0.2 to 0.8. The air electrode may include hydrophobic, porous fibers. In particular embodiments, the air electrode is soaked with an electrolyte comprising one or more solvents including dimethyl ether, and the dimethyl ether subsequently is evacuated from the soaked electrode. In other embodiments, the electrolyte comprises 10-20% crown ether by weight.

21 CFR 113.40 - Equipment and procedures.

Code of Federal Regulations, 2011 CFR

2011-04-01

... ensure a supply of clean, dry air. (3) Pressure gages. Each retort should be equipped with a pressure... should have adequate filter systems to ensure a supply of clean, dry air. (3) Pressure gages. (i) Each... controllers should have adequate filter systems to ensure a supply of clean, dry air. (3) Pressure gages. Each...

21 CFR 113.40 - Equipment and procedures.

Code of Federal Regulations, 2014 CFR

2014-04-01

... have adequate filter systems to ensure a supply of clean, dry air. A steam controller activated by the... ensure a supply of clean, dry air. (5) Steam introduction. Steam shall be distributed in the bottom of... temperature controllers should have adequate filter systems to ensure a supply of clean, dry air. (5) Bleeders...

21 CFR 113.40 - Equipment and procedures.

Code of Federal Regulations, 2013 CFR

2013-04-01

... have adequate filter systems to ensure a supply of clean, dry air. A steam controller activated by the... ensure a supply of clean, dry air. (5) Steam introduction. Steam shall be distributed in the bottom of... temperature controllers should have adequate filter systems to ensure a supply of clean, dry air. (5) Bleeders...

21 CFR 113.40 - Equipment and procedures.

Code of Federal Regulations, 2012 CFR

2012-04-01

... have adequate filter systems to ensure a supply of clean, dry air. A steam controller activated by the... ensure a supply of clean, dry air. (5) Steam introduction. Steam shall be distributed in the bottom of... temperature controllers should have adequate filter systems to ensure a supply of clean, dry air. (5) Bleeders...

40 CFR 721.9719 - Tris carbamoyl triazine (generic).

Code of Federal Regulations, 2012 CFR

2012-07-01

... the requirements for § 721.63(a)(4): (A) Air purifying, tight-fitting half-face respirator equipped... filter (N100 if oil aerosols are absent, R100, or P100); (B) Air purifying, tight-fitting full-face...) filter; powered air-purifying respirator equipped with tight-fitting facepiece (either half-face or full...

Reducing indoor air pollutants with air filtration units in wood stove homes.

PubMed

McNamara, Marcy L; Thornburg, Jonathon; Semmens, Erin O; Ward, Tony J; Noonan, Curtis W

2017-08-15

Biomass burning has been shown to be a major source of poor indoor air quality (IAQ) in developing and higher income countries across the world. Specifically, wood burning for cooking and heating contributes to high indoor concentrations of fine (particles with aerodynamic diameters<2.5μm; PM 2.5 ) and coarse (particles with aerodynamic diameters <10μm and >2.5μm; PMc) particulate matter. Endotoxin, predominantly found within the coarse fraction of airborne particulate matter, is associated with proinflammatory effects and adverse outcomes among susceptible populations. The aim of this study was to assess the efficacy of air filter interventions in reducing indoor PM 2.5 , PMc, and PMc-associated endotoxin concentrations in homes using a wood stove for primary heating. Homes (n=48) were randomized to receive in-room air filtration units with either a high efficiency filter (i.e. active) or a lower efficiency fiberglass filter (i.e., placebo). The active filter intervention showed a 66% reduction in indoor PM 2.5 concentrations (95% CI: 42.2% to 79.7% reduction) relative to the placebo intervention. Both the active and the placebo filters were effective in substantially reducing indoor concentrations of PMc (63.3% and 40.6% average reduction for active and placebo filters, respectively) and PMc-associated endotoxin concentrations (91.8% and 80.4% average reductions, respectively). These findings support the use of high efficiency air filtration units for reducing indoor PM 2.5 in homes using a wood stove for primary heating. We also discovered that using lower efficiency, lower cost filter alternatives can be effective for reducing PMc and airborne endotoxin in homes burning biomass fuel. Copyright © 2017. Published by Elsevier B.V.

Removal of viable bioaerosol particles with a low-efficiency HVAC filter enhanced by continuous emission of unipolar air ions.

PubMed

Huang, R; Agranovski, I; Pyankov, O; Grinshpun, S

2008-04-01

Continuous emission of unipolar ions has been shown to improve the performance of respirators and stationary filters challenged with non-biological particles. In this study, we investigated the ion-induced enhancement effect while challenging a low-efficiency heating, ventilation and air-conditioning (HVAC) filter with viable bacterial cells, bacterial and fungal spores, and viruses. The aerosol concentration was measured in real time. Samples were also collected with a bioaerosol sampler for viable microbial analysis. The removal efficiency of the filter was determined, respectively, with and without an ion emitter. The ionization was found to significantly enhance the filter efficiency in removing viable biological particles from the airflow. For example, when challenged with viable bacteria, the filter efficiency increased as much as four- to fivefold. For viable fungal spores, the ion-induced enhancement improved the efficiency by a factor of approximately 2. When testing with virus-carrying liquid droplets, the original removal efficiency provided by the filter was rather low: 9.09 +/- 4.84%. While the ion emission increased collection about fourfold, the efficiency did not reach 75-100% observed with bacteria and fungi. These findings, together with our previously published results for non-biological particles, demonstrate the feasibility of a new approach for reducing aerosol particles in HVAC systems used for indoor air quality control. Recirculated air in HVAC systems used for indoor air quality control in buildings often contains considerable number of viable bioaerosol particles because of limited efficiency of the filters installed in these systems. In the present study, we investigated - using aerosolized bacterial cells, bacterial and fungal spores, and virus-carrying particles - a novel idea of enhancing the performance of a low-efficiency HVAC filter utilizing continuous emission of unipolar ions in the filter vicinity. The findings described in this paper, together with our previously published results for non-biological particles, demonstrate the feasibility of the newly developed approach.

Histology of Tissue Adherent to OptEase Inferior Vena Cava Filters Regarding Indwelling Time

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rimon, Uri, E-mail: rimonu@sheba.health.gov.il; Volkov, Alexander; Garniek, Alexander

The purpose of this paper is to report on the histology of tissues found on retrieved filters with regard to indwelling time. Between February 2006 and January 2007, 28 Optease inferior vena cava filters (Cordis Europa, Roden, The Netherlands) were retrieved from 27 patients. Twenty-two filters were inserted prophylactically for trauma patients and six for patients with venous thromboembolism. Cavography was performed both before and after filter removal to evaluate the presence of thrombi or wall damage. Filters were retrieved with the snare and sheath method. All material adherents to the filters were examined histologically.The mean indwelling time of themore » filters was 24.9 days (range, 6-69 days). Red tissue fragments were seen on all the filters, consistent microscopically with clots and fibrin. On five filters (18%; mean indwelling time, 45.4 days) white tissue consistent with vascular intima was found. All postprocedure cavographies were normal. We conclude that most material adherent to the retrieved filters is thrombi, while vascular intima can be found in the minority of filters with a longer indwelling time.« less

Low-loss lateral-extensional piezoelectric filters on ultrananocrystalline diamond.

PubMed

Fatemi, Hediyeh; Abdolvand, Reza

2013-09-01

In this work, lateral-extensional thin-film piezoelectric- on-diamond (TPoD) filters with very low insertion loss (IL) values (<4 dB) are reported. Two different lateral-extensional modes of a resonant structure are coupled together to realize a two-pole filter. The filters of this work exhibit low IL values, with fractional bandwidth between 0.08% and 0.2%, and have a very small footprint. This paper reports on the lowest IL in the literature for lateral-extensional thin-film piezoelectric filters with 50 Ω terminations in the GSM frequency band (~900 MHz). The narrow-band filters of this work are fabricated on three ultrananocrystalline diamond substrates to achieve higher frequencies without excessive reduction in the feature size. The paper also thoroughly studies the parameters that affect the performance of such filters and then discussions are evaluated by the statistical data collected from the fabricated wafers.

[Contamination levels to room air arising from the use of 99mTc-gas and prevention from the contamination].

PubMed

Komatani, A; Akutsu, T; Yamaguchi, K; Onodera, Y; Manaka, Y; Takahashi, K

1996-04-01

99mTc-gas (TECHNEGAS) is a 99mTc-labeled micro-aerosol which is considered to have different behavior from 133Xe or 81mKr gas. In order to estimate contamination levels to room air arising from the use of 99mTc-gas, filtered expired air during administration and 1, 2, 3, 5, 10 min after the administration were collected in each polyethylene bag. Radioactivities of the polyethylene bags, used filter and the lung were measured with 3-head scintillation camera. The activity of the expired air diminished within 6-10 min and about 5% of whole discharged 99mTc-gas was released to room air. The activity of the used filter was two times of the lung. According to these results, it is recommended that the 99mTc-gas may be administrated in a exclusive room. The administrated patient and used filter must be remain in the exclusive room.

Formulation and implementation of nonstationary adaptive estimation algorithm with applications to air-data reconstruction

NASA Technical Reports Server (NTRS)

Whitmore, S. A.

1985-01-01

The dynamics model and data sources used to perform air-data reconstruction are discussed, as well as the Kalman filter. The need for adaptive determination of the noise statistics of the process is indicated. The filter innovations are presented as a means of developing the adaptive criterion, which is based on the true mean and covariance of the filter innovations. A method for the numerical approximation of the mean and covariance of the filter innovations is presented. The algorithm as developed is applied to air-data reconstruction for the space shuttle, and data obtained from the third landing are presented. To verify the performance of the adaptive algorithm, the reconstruction is also performed using a constant covariance Kalman filter. The results of the reconstructions are compared, and the adaptive algorithm exhibits better performance.

40 CFR 90.407 - Engine inlet and exhaust systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine must...

40 CFR 90.407 - Engine inlet and exhaust systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine must...

40 CFR 90.407 - Engine inlet and exhaust systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine must...

40 CFR 90.407 - Engine inlet and exhaust systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine must...

40 CFR 90.407 - Engine inlet and exhaust systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine must...

Effects of ceiling-mounted HEPA-UV air filters on airborne bacteria concentrations in an indoor therapy pool building.

PubMed

Kujundzic, Elmira; Zander, David A; Hernandez, Mark; Angenent, Largus T; Henderson, David E; Miller, Shelly L

2005-02-01

The purpose of this study was to assess the effectiveness of a new generation of high-volume, ceiling-mounted high-efficiency particulate air (HEPA)-ultraviolet (UV) air filters (HUVAFs) for their ability to remove or inactivate bacterial aerosol. In an environmentally controlled full-scale laboratory chamber (87 m3), and an indoor therapy pool building, the mitigation ability of air filters was assessed by comparing concentrations of total bacteria, culturable bacteria, and airborne endotoxin with and without the air filters operating under otherwise similar conditions. Controlled chamber tests with pure cultures of aerosolized Mycobacterium parafortuitum cells showed that the HUVAF unit tested provided an equivalent air-exchange rate of 11 hr(-1). Using this equivalent air-exchange rate as a design basis, three HUVAFs were installed in an indoor therapy pool building for bioaerosol mitigation, and their effectiveness was studied over a 2-year period. The HUVAFs reduced concentrations of culturable bacteria by 69 and 80% during monitoring periods executed in respective years. The HUVAFs reduced concentrations of total bacteria by 12 and 76% during the same monitoring period, respectively. Airborne endotoxin concentrations were not affected by the HUVAF operation.

Characterization of outdoor air particles as source of impurities in supply air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pasanen, P.; Kalliokoski, P.; Tuomainen, A.

1997-12-31

Odor emission of supply air filters has proved to be a major source of stuffy odor of supply air. In this study, the odor emission characteristics of outdoor air particles and odor emissions of coarse prefilters and fine filters were studied. The outdoor air samples were collected by the aid of high volume impactor. Odor emissions of the size fractions, < 2.1 {micro}m , 2.1--10 {micro}m and >10 {micro}m were studied separately in laboratory with a trained olf panel: The odor emissions of the ventilation filters in real use were evaluated five times during the 14 month study period. Aftermore » the field evaluation the emissions of carbonyl compounds and other volatile organic compounds. The odor emissions of outdoor air particles were the highest during the heating season and lowest in the summer. The particles in the coarsest fraction had the most abundant emissions (1,200 olf/g) while the emissions from fine particles were lowest (100 olf/g). The odor emissions evaluated from the coarse and fine ventilation filters supported the finding that particles collected on coarse prefilter had the most abundant odor emission.« less

Air-to-Air Missile Vector Scoring

DTIC Science & Technology

2012-03-22

SIR sampling-importance resampling . . . . . . . . . . . . . . 53 EPF extended particle filter . . . . . . . . . . . . . . . . . . . . 54 UPF unscented...particle filter ( EPF ) or a unscented particle fil- ter (UPF) [20]. The basic concept is to apply a bank of N EKF or UKF filters to move particles from...Merwe, Doucet, Freitas and Wan provide a comprehensive discussion on the EPF and UPF, including algorithms for implementation [20]. 2Result based on

The long-term performance of electrically charged filters in a ventilation system.

PubMed

Raynor, Peter C; Chae, Soo Jae

2004-07-01

The efficiency and pressure drop of filters made from polyolefin fibers carrying electrical charges were compared with efficiency and pressure drop for filters made from uncharged glass fibers to determine if the efficiency of the charged filters changed with use. Thirty glass fiber filters and 30 polyolefin fiber filters were placed in different, but nearly identical, air-handling units that supplied outside air to a large building. Using two kinds of real-time aerosol counting and sizing instruments, the efficiency of both sets of filters was measured repeatedly for more than 19 weeks while the air-handling units operated almost continuously. Pressure drop was recorded by the ventilation system's computer control. Measurements showed that the efficiency of the glass fiber filters remained almost constant with time. However, the charged polyolefin fiber filters exhibited large efficiency reductions with time before the efficiency began to increase again toward the end of the test. For particles 0.6 microm in diameter, the efficiency of the polyolefin fiber filters declined from 85% to 45% after 11 weeks before recovering to 65% at the end of the test. The pressure drops of the glass fiber filters increased by about 0.40 in. H2O, whereas the pressure drop of the polyolefin fiber filters increased by only 0.28 in. H2O. The results indicate that dust loading reduces the effectiveness of electrical charges on filter fibers. Copyright 2004 JOEH, LLC

Tailoring Mechanically Robust Poly(m-phenylene isophthalamide) Nanofiber/nets for Ultrathin High-Efficiency Air Filter

PubMed Central

Zhang, Shichao; Liu, Hui; Yin, Xia; Li, Zhaoling; Yu, Jianyong; Ding, Bin

2017-01-01

Effective promotion of air filtration applications proposed for fibers requires their real nanoscale diameter, optimized pore structure, and high service strength; however, creating such filter medium has proved to be a tremendous challenge. This study first establishes a strategy to design and fabricate novel poly(m-phenylene isophthalamide) nanofiber/nets (PMIA NF/N) air filter via electrospinning/netting. Our strategy results in generation of a bimodal structure including a scaffold of nanofibers and abundant two-dimensional ultrathin (~20 nm) nanonets to synchronously construct PMIA filters by combining solution optimization, humidity regulation, and additive inspiration. Benefiting from the structural features including the true nanoscale diameter, small pore size, high porosity, and nets bonding contributed by the widely distributed nanonets, our PMIA NF/N filter exhibits the integrated properties of superlight weight (0.365 g m−2), ultrathin thickness (~0.5 μm), and high tensile strength (72.8 MPa) for effective air filtration, achieving the ultra-low penetration air filter level of 99.999% and low pressure drop of 92 Pa for 300–500 nm particles by sieving mechanism. The successful synthesis of PMIA NF/N would not only provide a promising medium for particle filtration, but also develop a versatile platform for exploring the application of nanonets in structural enhancement, separation and purification. PMID:28074880

Tailoring Mechanically Robust Poly(m-phenylene isophthalamide) Nanofiber/nets for Ultrathin High-Efficiency Air Filter

NASA Astrophysics Data System (ADS)

Zhang, Shichao; Liu, Hui; Yin, Xia; Li, Zhaoling; Yu, Jianyong; Ding, Bin

2017-01-01

Effective promotion of air filtration applications proposed for fibers requires their real nanoscale diameter, optimized pore structure, and high service strength; however, creating such filter medium has proved to be a tremendous challenge. This study first establishes a strategy to design and fabricate novel poly(m-phenylene isophthalamide) nanofiber/nets (PMIA NF/N) air filter via electrospinning/netting. Our strategy results in generation of a bimodal structure including a scaffold of nanofibers and abundant two-dimensional ultrathin (~20 nm) nanonets to synchronously construct PMIA filters by combining solution optimization, humidity regulation, and additive inspiration. Benefiting from the structural features including the true nanoscale diameter, small pore size, high porosity, and nets bonding contributed by the widely distributed nanonets, our PMIA NF/N filter exhibits the integrated properties of superlight weight (0.365 g m-2), ultrathin thickness (~0.5 μm), and high tensile strength (72.8 MPa) for effective air filtration, achieving the ultra-low penetration air filter level of 99.999% and low pressure drop of 92 Pa for 300-500 nm particles by sieving mechanism. The successful synthesis of PMIA NF/N would not only provide a promising medium for particle filtration, but also develop a versatile platform for exploring the application of nanonets in structural enhancement, separation and purification.

Electrospun Magnetic Nanoparticle-Decorated Nanofiber Filter and Its Applications to High-Efficiency Air Filtration.

PubMed

Kim, Juyoung; Chan Hong, Seung; Bae, Gwi Nam; Jung, Jae Hee

2017-10-17

Filtration technology has been widely studied due to concerns about exposure to airborne dust, including metal oxide nanoparticles, which cause serious health problems. The aim of these studies has been to develop mechanisms for the continuous and efficient removal of metal oxide dusts. In this study, we introduce a novel air filtration system based on the magnetic attraction force. The filtration system is composed of a magnetic nanoparticle (MNP)-decorated nanofiber (MNP-NF) filter. Using a simple electrospinning system, we fabricated continuous and smooth electrospun nanofibers with evenly distributed Fe 3 O 4 MNPs. Our electrospun MNP-NF filter exhibited high particle collection efficiency (∼97% at 300 nm particle size) compared to the control filter (w/o MNPs, ∼ 68%), with a ∼ 64% lower pressure drop (∼17 Pa) than the control filter (∼27 Pa). Finally, the filter quality factors of the MNP-NF filter were 4.7 and 11.9 times larger than those of the control filter and the conventional high-efficiency particulate air filters (>99% and ∼269 Pa), respectively. Furthermore, we successfully performed a field test of our MNP-NF filter using dust from a subway station tunnel. This work suggests that our novel MNP-NF filter can be used to facilitate effective protection against hazardous metal oxide dust in real environments.

Summary of efficiency testing of standard and high-capacity high-efficiency particulate air filters subjected to simulated tornado depressurization and explosive shock waves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, P.R.; Gregory, W.S.

1985-04-01

Pressure transients in nuclear facility air cleaning systems can originate from natural phenomena such as tornadoes or from accident-induced explosive blast waves. This study was concerned with the effective efficiency of high-efficiency particulate air (HEPA) filters during pressure surges resulting from simulated tornado and explosion transients. The primary objective of the study was to examine filter efficiencies at pressure levels below the point of structural failure. Both standard and high-capacity 0.61-m by 0.61-m HEPA filters were evaluated, as were several 0.2-m by 0.2-m HEPA filters. For a particular manufacturer, the material release when subjected to tornado transients is the samemore » (per unit area) for both the 0.2-m by 0.2-m and the 0.61-m by 0.61-m filters. For tornado transients, the material release was on the order of micrograms per square meter. When subjecting clean HEPA filters to simulated tornado transients with aerosol entrained in the pressure pulse, all filters tested showed a degradation of filter efficiency. For explosive transients, the material release from preloaded high-capacity filters was as much as 340 g. When preloaded high-capacity filters were subjected to shock waves approximately 50% of the structural limit level, 1 to 2 mg of particulate was released.« less

Workplace Exposure to Titanium Dioxide Nanopowder Released from a Bag Filter System

PubMed Central

Ji, Jun Ho; Kim, Jong Bum; Lee, Gwangjae; Noh, Jung-Hun; Yook, Se-Jin; Cho, So-Hye; Bae, Gwi-Nam

2015-01-01

Many researchers who use laboratory-scale synthesis systems to manufacture nanomaterials could be easily exposed to airborne nanomaterials during the research and development stage. This study used various real-time aerosol detectors to investigate the presence of nanoaerosols in a laboratory used to manufacture titanium dioxide (TiO2). The TiO2 nanopowders were produced via flame synthesis and collected by a bag filter system for subsequent harvesting. Highly concentrated nanopowders were released from the outlet of the bag filter system into the laboratory. The fractional particle collection efficiency of the bag filter system was only 20% at particle diameter of 100 nm, which is much lower than the performance of a high-efficiency particulate air (HEPA) filter. Furthermore, the laboratory hood system was inadequate to fully exhaust the air discharged from the bag filter system. Unbalanced air flow rates between bag filter and laboratory hood systems could result in high exposure to nanopowder in laboratory settings. Finally, we simulated behavior of nanopowders released in the laboratory using computational fluid dynamics (CFD). PMID:26125024

A Pollen Primer | NIH MedlinePlus the Magazine

MedlinePlus

... air filters (HEPA) or an electrostatic air filter. Tree Pollen Trees produce pollen earliest, as soon as January in ... distributed miles away. Fewer than 100 kinds of trees cause allergies. Some common ones are catalpa, elm, ...

9 CFR 590.546 - Albumen flake process drying facilities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... be equipped with approved intake filters. (b) The intake air source shall be free from foul odors, dust, and dirt. (c) Premix-type burners, if used, shall be equipped with approved air filters at blower...

9 CFR 590.546 - Albumen flake process drying facilities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... be equipped with approved intake filters. (b) The intake air source shall be free from foul odors, dust, and dirt. (c) Premix-type burners, if used, shall be equipped with approved air filters at blower...

Apparatus and method for removing particulate deposits from high temperature filters

DOEpatents

Nakaishi, Curtis V.; Holcombe, Norman T.; Micheli, Paul L.

1992-01-01

A combustion of a fuel-air mixture is used to provide a high-temperature and high-pressure pulse of gaseous combustion products for the back-flush cleaning of ceramic filter elements contained in a barrier filter system and utilized to separate particulates from particulate-laden process gases at high temperature and high pressure. The volume of gaseous combustion products provided by the combustion of the fuel-air mixture is preferably divided into a plurality of streams each passing through a sonic orifice and conveyed to the open end of each filter element as a high pressure pulse which passes through the filter elements and dislodges dust cake supported on a surface of the filter element.

Using liquid desiccant as a regenerable filter for capturing and deactivating contaminants

DOEpatents

Slayzak, Steven J.; Anderson, Ren S.; Judkoff, Ronald D.; Blake, Daniel M.; Vinzant, Todd B.; Ryan, Joseph P.

2007-12-11

A method, and systems for implementing such method, for purifying and conditioning air of weaponized contaminants. The method includes wetting a filter packing media with a salt-based liquid desiccant, such as water with a high concentration of lithium chloride. Air is passed through the wetted filter packing media and the contaminants in are captured with the liquid desiccant while the liquid desiccant dehumidifies the air. The captured contaminants are then deactivated in the liquid desiccant, which may include heating the liquid desiccant. The liquid desiccant is regenerated by applying heat to the liquid desiccant and then removing moisture. The method includes repeating the wetting with the regenerated liquid desiccant which provides a regenerable filtering process that captures and deactivates contaminants on an ongoing basis while also conditioning the air. The method may include filtration effectiveness enhancement by electrostatic or inertial means.

Performance of a high T (sub c) superconducting ultra-low loss microwave stripline filter

NASA Technical Reports Server (NTRS)

Bautista, J. J.; Ortiz, G.; Zahopoulos, C.; Sridhar, S.; Lanagan, M.

1991-01-01

Discussed here is the successful fabrication of a five-pole interdigital stripline filter made of the 93 K superconductor (Y1Ba2Cu3O sub y) coated on a silver substrate, with center frequency of 8.5 GHz and an extremely high rejection ratio of 80 dB. The lowest injection loss measured was 0.1 dB at 12 K, with a return loss of better than 16 dB, representing a significant improvement over a similar copper filter, and is comparable to low critical temperature filters. The insertion loss appears to be limited by extrinsic factors, such as tuning mismatch and joint losses, and not by superconducting material losses.

Design optimization of integrated BiDi triplexer optical filter based on planar lightwave circuit.

PubMed

Xu, Chenglin; Hong, Xiaobin; Huang, Wei-Ping

2006-05-29

Design optimization of a novel integrated bi-directional (BiDi) triplexer filter based on planar lightwave circuit (PLC) for fiber-to-the premise (FTTP) applications is described. A multi-mode interference (MMI) device is used to filter the up-stream 1310nm signal from the down-stream 1490nm and 1555nm signals. An array waveguide grating (AWG) device performs the dense WDM function by further separating the two down-stream signals. The MMI and AWG are built on the same substrate with monolithic integration. The design is validated by simulation, which shows excellent performance in terms of filter spectral characteristics (e.g., bandwidth, cross-talk, etc.) as well as insertion loss.

Design optimization of integrated BiDi triplexer optical filter based on planar lightwave circuit

NASA Astrophysics Data System (ADS)

Xu, Chenglin; Hong, Xiaobin; Huang, Wei-Ping

2006-05-01

Design optimization of a novel integrated bi-directional (BiDi) triplexer filter based on planar lightwave circuit (PLC) for fiber-to-the premise (FTTP) applications is described. A multi-mode interference (MMI) device is used to filter the up-stream 1310nm signal from the down-stream 1490nm and 1555nm signals. An array waveguide grating (AWG) device performs the dense WDM function by further separating the two down-stream signals. The MMI and AWG are built on the same substrate with monolithic integration. The design is validated by simulation, which shows excellent performance in terms of filter spectral characteristics (e.g., bandwidth, cross-talk, etc.) as well as insertion loss.

A wideband superconducting filter at Ku-band based on interdigital coupling

NASA Astrophysics Data System (ADS)

Jiang, Ying; Wei, Bin; Cao, Bisong; Li, Qirong; Guo, Xubo; Jiang, Linan; Song, Xiaoke; Wang, Xiang

2018-04-01

In this paper, an interdigital-type resonator with strong electric coupling is proposed for the wideband high-frequency (>10 GHz) filter design. The proposed microstrip resonator consists of an H-shaped main line part with its both ends installed with interdigital finger parts. Strong electric coupling is achieved between adjacent resonators. A six-pole high-temperature superconducting filter at Ku-band using this resonator is designed and fabricated. The filter has a center frequency of 15.11 GHz with a fractional bandwidth of 30%. The insertion loss of the passband is less than 0.3 dB, and the return loss is greater than 14 dB without any tuning.

Background culturable bacteria aerosol in two large public buildings using HVAC filters as long term, passive, high-volume air samplers.

PubMed

Stanley, Nicholas J; Kuehn, Thomas H; Kim, Seung Won; Raynor, Peter C; Anantharaman, Senthilvelan; Ramakrishnan, M A; Goyal, Sagar M

2008-04-01

Background culturable bacteria aerosols were collected and identified in two large public buildings located in Minneapolis, Minnesota and Seattle, Washington over a period of 5 months and 3 months, respectively. The installed particulate air filters in the ventilation systems were used as the aerosol sampling devices at each location. Both pre and final filters were collected from four air handing units at each site to determine the influence of location within the building, time of year, geographical location and difference between indoor and outdoor air. Sections of each loaded filter were eluted with 10 ml of phosphate buffered saline (PBS). The resulting solutions were cultured on blood agar plates and incubated for 24 h at 36 degrees C. Various types of growth media were then used for subculturing, followed by categorization using a BioLog MicroStation (Biolog, Hayward, CA, USA) and manual observation. Environmental parameters were gathered near each filter by the embedded on-site environmental monitoring systems to determine the effect of temperature, humidity and air flow. Thirty nine different species of bacteria were identified, 17 found only in Minneapolis and 5 only in Seattle. The hardy spore-forming genus Bacillus was the most commonly identified and showed the highest concentrations. A significant decrease in the number of species and their concentration occurred in the Minneapolis air handling unit supplying 100% outdoor air in winter, however no significant correlations between bacteria concentration and environmental parameters were found.

Large-scale generic test stand for testing of multiple configurations of air filters utilizing a range of particle size distributions

NASA Astrophysics Data System (ADS)

Giffin, Paxton K.; Parsons, Michael S.; Unz, Ronald J.; Waggoner, Charles A.

2012-05-01

The Institute for Clean Energy Technology (ICET) at Mississippi State University has developed a test stand capable of lifecycle testing of high efficiency particulate air filters and other filters specified in American Society of Mechanical Engineers Code on Nuclear Air and Gas Treatment (AG-1) filters. The test stand is currently equipped to test AG-1 Section FK radial flow filters, and expansion is currently underway to increase testing capabilities for other types of AG-1 filters. The test stand is capable of producing differential pressures of 12.45 kPa (50 in. w.c.) at volumetric air flow rates up to 113.3 m3/min (4000 CFM). Testing is performed at elevated and ambient conditions for temperature and relative humidity. Current testing utilizes three challenge aerosols: carbon black, alumina, and Arizona road dust (A1-Ultrafine). Each aerosol has a different mass median diameter to test loading over a wide range of particles sizes. The test stand is designed to monitor and maintain relative humidity and temperature to required specifications. Instrumentation is implemented on the upstream and downstream sections of the test stand as well as on the filter housing itself. Representative data are presented herein illustrating the test stand's capabilities. Digital images of the filter pack collected during and after testing is displayed after the representative data are discussed. In conclusion, the ICET test stand with AG-1 filter testing capabilities has been developed and hurdles such as test parameter stability and design flexibility overcome.

Numerical study on self-cleaning canister filter with modified filter cap

NASA Astrophysics Data System (ADS)

Mohammed, Akmal Nizam; Zolkhaely, Mohd Hafiz; Sahrudin, Mohd Sahrizan; Razali, Mohd Azahari; Sapit, Azwan; Hushim, Mohd Faisal

2017-04-01

Air filtration system plays an important role in getting good quality air into turbo machinery such as gas turbine. The filtration system and filters improve the quality of air and protect the gas turbine parts from contaminants which could bring damage. This paper is focused on the configuration of the self-cleaning canister filter in order to obtain the minimal pressure drop along the filter. The configuration includes a modified canister filter cap that is based on the basic geometry that conforms to industry standard. This paper describes the use of CFD to simulate and analyze the flow through the filter. This tool is also used to monitor variables such as pressure and velocity along the filter and to visualize them in the form of contours, vectors and streamlines. In this study, the main parameter varied is the inlet velocity set in the boundary condition during simulations, which are 0.032, 0.063, 0.094 and 0.126 m/s respectively. The data obtained from simulations are then validated with reference data sourced from the industry, and comparisons have subsequently been made for these two filters. As a result, the improvement of the pressure drop for the modified filter is found to be 11.47% to 14.82% compared to the basic filter at the inlet velocity from 0.032 to 0.126 m/s. the total pressure drop produced is 292.3 Pa by the basic filter and 251.11 Pa for modified filter. The pressure drop reduction is 41.19 Pa, which is 14.1% from the basic filter.

Removal of infused water predominantly during insertion (water exchange) is consistently associated with an increase in adenoma detection rate - review of data in randomized controlled trials (RCTs) of water-related methods

PubMed Central

Harker, JO; Leung, JW; Siao-Salera, RM; Mann, SK; Ramirez, FC; Friedland, S; Amato, A; Radaelli, F; Paggi, S; Terruzzi, V; Hsieh, YH

2011-01-01

Introduction Variation in outcomes in RcTs comparing water-related methods and air insufflation raises challenging questions regarding the new approach. This report reviews impact of water exchange - simultaneous infusion and removal of infused water during insertion on adenoma detection rate (ADR) defined as proportion of patients with a least one adenoma of any size. Methods Medline (2008–2011) searches, abstract of 2011 Digestive Disease Week (DDW) meeting and personal communications were considered to identify RcTs that compared water-related methods and air insufflation to aid insertion of colonoscope. Results Since 2008, eleven reports of RcTs (6 published, 1 submitted and 4 abstracts, n=1728) described ADR in patients randomized to be examined by air and water-related methods. The water-related methods differed in timing of removal of the infused water -predominantly during insertion (water exchange) (n=825) or predominantly during withdrawal (water immersion) (n=903). Water immersion was associated with both increases and decreases in ADR compared to respective air method patients and the net overall change (-7%) was significant. On the other hand water exchange was associated with increases in ADR consistently and the net changes (overall, 8%; proximal overall, 11%; and proximal <10 mm, 12%) were all significant. Conclusion Comparative data generated the hypothesis that significantly larger increases in overall and proximal colon ADRs were associated with water exchange than water immersion or air insufflation during insertion. The hypothesis should be evaluated by RCTs to elucidate the mechanism of water exchange on adenoma detection. PMID:22163082

21 CFR 886.1800 - Schirmer strip.

Code of Federal Regulations, 2010 CFR

2010-04-01

... device made of filter paper or similar material intended to be inserted under a patient's lower eyelid to stimulate and evaluate formation of tears. (b) Classification. Class I (general controls). If the device is...

Cabin air filtration: helping to protect occupants from infectious diseases.

PubMed

Bull, Karen

2008-05-01

Presentation made at the Aviation Health Conference, London, November 2006. In modern aircraft, the air in the cabin is provided by the environmental control system (ECS) and consists of approximately 50% outside air (engine 'bleed air') mixed with approximately 50% filtered, recirculated air. This paper describes how modern aircraft cabin air filters are effective at removing airborne particulate contamination (such as bacteria and viruses) from the recirculated air system. It also describes one of the technological solutions that is currently available to treat any odours or volatile organic compounds (VOCs) that may be present in the aircraft ECS.

Emergency sacrificial sealing method in filters, equipment, or systems

DOEpatents

Brown, Erik P

2014-09-30

A system seals a filter or equipment component to a base and will continue to seal the filter or equipment component to the base in the event of hot air or fire. The system includes a first sealing material between the filter or equipment component and the base; and a second sealing material between the filter or equipment component and the base and proximate the first sealing material. The first sealing material and the second seal material are positioned relative to each other and relative to the filter or equipment component and the base to seal the filter or equipment component to the base and upon the event of fire the second sealing material will be activated and expand to continue to seal the filter or equipment component to the base in the event of hot air or fire.

Air-conditioner filters enriching dust mites allergen.

PubMed

Zhan, Xiaodong; Li, Chaopin; Xu, Haifeng; Xu, Pengfei; Zhu, Haibin; Diao, Jidong; Li, Na; Zhao, Beibei

2015-01-01

We detected the concentration of dust mites allergen (Der f1 & Der p1) in the air of different places before and after the starting of air-conditioners in Wuhu City, Anhui, China, and to discuss the relation between the dust mites allergen in air-conditioner filters and the asthma attack. The dust samples were collected from the air-conditioner filters in dining rooms, shopping malls, hotels and households respectively. Concentrations of dust mites major group allergen 1 (Der f 1, Der p1) were detected with enzyme linked immunosorbent assay (ELISA), and the dust mite immune activities were determined by dot-ELISA. The concentration of Der f1 in dining rooms, shopping malls, hotels and households was 1.52 μg/g, 1.24 μg/g, 1.31 μg/g and 1.46 μg/g respectively, and the concentration of Der p1 in above-mentioned places was 1.23 μg/g, 1.12 μg/g, 1.16 μg/g and 1.18 μg/g respectively. The concentration of Der f1 & Der p1 in air was higher after the air-conditioners starting one hours later, and the difference was significant (P<0.05, respectively). Additionally, dot-ELISA findings revealed that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. The study concludes that air-conditioner filters can enrich dust mites major group allergen, and the allergens can induce asthma. The air-conditioner filters shall be cleaned or replaced regularly to prevent or reduce accumulation of the dust mites and its allergens.

Air-conditioner filters enriching dust mites allergen

PubMed Central

Zhan, Xiaodong; Li, Chaopin; Xu, Haifeng; Xu, Pengfei; Zhu, Haibin; Diao, Jidong; Li, Na; Zhao, Beibei

2015-01-01

We detected the concentration of dust mites allergen (Der f1 & Der p1) in the air of different places before and after the starting of air-conditioners in Wuhu City, Anhui, China, and to discuss the relation between the dust mites allergen in air-conditioner filters and the asthma attack. The dust samples were collected from the air-conditioner filters in dining rooms, shopping malls, hotels and households respectively. Concentrations of dust mites major group allergen 1 (Der f 1, Der p1) were detected with enzyme linked immunosorbent assay (ELISA), and the dust mite immune activities were determined by dot-ELISA. The concentration of Der f1 in dining rooms, shopping malls, hotels and households was 1.52 μg/g, 1.24 μg/g, 1.31 μg/g and 1.46 μg/g respectively, and the concentration of Der p1 in above-mentioned places was 1.23 μg/g, 1.12 μg/g, 1.16 μg/g and 1.18 μg/g respectively. The concentration of Der f1 & Der p1 in air was higher after the air-conditioners starting one hours later, and the difference was significant (P<0.05, respectively). Additionally, dot-ELISA findings revealed that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. The study concludes that air-conditioner filters can enrich dust mites major group allergen, and the allergens can induce asthma. The air-conditioner filters shall be cleaned or replaced regularly to prevent or reduce accumulation of the dust mites and its allergens. PMID:26064381

FILTER FOR HIGH VELOCITY GAS STREAMS

DOEpatents

Heckman, R.A.; Warner, H.F.

1963-11-01

An air filter that is particularly useful in air-sampling rockets is presented. The filter comprises a cellulose fiber mat having an evenly disposed thin coating of stearic acid. Protective loose weave fabric covers are stitched to the front and back of the fiber mat, the stitching being in the form of a sine wave spiraled from the midpoint of the mat out to its periphery. (AEC)

A simple and inexpensive method for maintaining a defined flora mouse colony.

PubMed

Sedlacek, R S; Mason, K A

1977-10-01

The use of autoclaved cages, feed, bedding, water, and filter caps combined with aseptic techniques of animal husbandry in an existing mouse colony was ineffective in maintaining a defined flora colony. The addition of a laminar air flow bench equipped with a high efficiency particulate air filter provided a sterile environment in which to manipulate mice when the filter caps were removed. The installation of a duct to direct all air entering the room through the bench filter reduced the airborne bacterial counts in the room. This modification combined with the culling or marking of infected cages so that no future breeders would be taken from these cages eliminated a number of bacterial contaminants (Staphylococcus aureus, S epidermidis, and streptococci) from the colony.

Effect of Selectively Etched Ferroelectric Thin-Film Layer on the Performance of a Tunable Bandpass Filter

NASA Technical Reports Server (NTRS)

Subramanyam, Guru; Vignesparamoorthy, Sivaruban; Mueller, Carl; VanKeuls, Fred; Warner, Joseph; Miranda, Felix A.

2001-01-01

The main purpose of this work is to study the effect of a selectively etched ferroelectric thin film layer on the performance of an electrically tunable filter. An X-band tunable filter was designed, fabricated and tested on a selectively etched Barium Strontium Titanate (BSTO) ferroelectric thin film layer. Tunable filters with varying lengths of BSTO thin-film in the input and output coupling gaps were modeled, as well as experimentally tested. Experimental results showed that filters with coupling gaps partially filled with BSTO maintained frequency tunability and improved the insertion loss by approx. 2dB. To the best of our knowledge, these results represent the first experimental demonstration of the advantages of selective etching in the performance of thin film ferroelectric-based tunable microwave components.

High emission reduction performance of a novel organic-inorganic composite filters containing sepiolite mineral nanofibers

PubMed Central

Wang, Fei; Zhang, Hui; Liang, Jinsheng; Tang, Qingguo; Li, Yanxia; Shang, Zengyao

2017-01-01

In this work, a new organic-inorganic composite filter was prepared. The thickness, pore size, air permeability, bursting strength and microstructure were characterized systematically, proving that coatings had regulatory effect on filters physical properties. Benefitting from the distinct coatings containing 5% sepiolite nanofibers after five times dilution, the physical properties of corresponding air filter exhibits the most favorable performance and meet the standard of air filter. When used as fuel filter, it satisfies the fuel filter standard and achieves the best performance after six times dilution. The contrast test on engine emission was taken based on auto filters coated with/without as prepared nanofibers. An obvious decrease in the emission of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NOx) can be observed after installation of composite filter on vehicles. Under the high idle condition, gasoline engine emission decreased by 8.13%, 11.35% and 44.91% for CO, HC and NOx, respectively. When tested in the low idle condition, engine emission reduced by 0.43%, 1.14% and 85.67% for CO, HC and NOx, respectively. The diesel engine emissions of CO, NOx and total amount of HC and NOx decreased by 32.26%, 3.28% and 4.66%, respectively. The results illustrate the composite installation exhibits satisfactory emission reduction effect. PMID:28252034

High emission reduction performance of a novel organic-inorganic composite filters containing sepiolite mineral nanofibers

NASA Astrophysics Data System (ADS)

Wang, Fei; Zhang, Hui; Liang, Jinsheng; Tang, Qingguo; Li, Yanxia; Shang, Zengyao

2017-03-01

In this work, a new organic-inorganic composite filter was prepared. The thickness, pore size, air permeability, bursting strength and microstructure were characterized systematically, proving that coatings had regulatory effect on filters physical properties. Benefitting from the distinct coatings containing 5% sepiolite nanofibers after five times dilution, the physical properties of corresponding air filter exhibits the most favorable performance and meet the standard of air filter. When used as fuel filter, it satisfies the fuel filter standard and achieves the best performance after six times dilution. The contrast test on engine emission was taken based on auto filters coated with/without as prepared nanofibers. An obvious decrease in the emission of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NOx) can be observed after installation of composite filter on vehicles. Under the high idle condition, gasoline engine emission decreased by 8.13%, 11.35% and 44.91% for CO, HC and NOx, respectively. When tested in the low idle condition, engine emission reduced by 0.43%, 1.14% and 85.67% for CO, HC and NOx, respectively. The diesel engine emissions of CO, NOx and total amount of HC and NOx decreased by 32.26%, 3.28% and 4.66%, respectively. The results illustrate the composite installation exhibits satisfactory emission reduction effect.

[Evaluation of the viability of BEAS-2B cells exposed to gasoline engine exhaust with different particle sizes by air-liquid interface].

PubMed

Yu, T; Zhang, X Y; Wang, Z X; Li, B; Zheng, Y X; Bin, P

2017-06-20

Objective: To evaluate the viability of gasoline engine exhaust (GEE) with different particle sizes on human lung cell line BEAS-2B in vitro by air-liquid interface (ALI) . Methods: GEE were collected with a Tedlar bag and their particulate matter (PM) number, surface and mass concentration in three kind of GEE (filtered automobile exhaust, non-filtered automobile exhaust and motorcycle exhaust without three-way catalytic converter) were measured by two type of particle size spectrometer including TSI-3321 and SMPS-3938. Five groups were included, which divided into blank control group, clean air group, filtered automobile exhaust group, non-filtered automobile exhaust group and motorcycle exhaust without three-way catalytic converter group. Except the blank control group, BEAS-2B cells, cultured on the surface of Transwells, were treated with clean air or GEE by ALI method at a flow rate of 25 ml/min, 37 ℃ for 60 min in vitro . CCK-8 cytotoxicity test kit was used to determine the cell relative viability of BEAS-2B cells. Results: In the filtered automobile exhaust, non-filtered automobile exhaust and motorcycle exhaust without three-way catalytic converter, high concentrations of fine particles can be detected, but the coarse particles only accounted for a small proportion, and the sequence of PM concentration was motorcycle exhaust without three-way catalytic converter group> non-filtered automobile exhaust group> filtered automobile exhaust group ( P <0.001) . Compared with the clean air group, the cell relative viability in the 3 GEE-exposed groups were significantly lower ( P <0.001) . Among the comparisons of GEE exposure groups with different particle size spectra, the sequence of the cell relative viability was filtered automobile exhaust group >non-filtered automobile exhaust group> motorcycle exhaust without three-way catalytic converter group ( P <0.001) . When took the clean air control group as a reference, the mean of the cell relative viability in the filtered automobile exhaust group, non-filtered automobile exhaust group and motorcycle exhaust without three-way catalytic converter group, was decreased by 26.34%, 36.00% and 49.59%, respectively. Conclusion: GEE with different particle size spectra could induce different levels of toxic effects to the human lung cells BEAS-2B by ALI. After lowering the concentration of particles in the GEE and using the three-way catalytic converter could obviously improve the survival rate of lung cells.

Interior Landscape Plants for Indoor Air Pollution Abatement

NASA Technical Reports Server (NTRS)

Wolverton, B. C.; Johnson, Anne; Bounds, Keith

1989-01-01

In this study, the leaves, roots, soil, and associated microorganisms of plants have been evaluated as a possible means of reducing indoor air pollutants. Additionally, a novel approach of using plant systems for removing high concentrations of indoor air pollutants such as cigarette smoke, organic solvents, and possibly radon has been designed from this work. This air filter design combines plants with an activated carbon filter. The rationale for this design, which evolved from wastewater treatment studies, is based on moving large volumes of contaminated air through an activated carbon bed where smoke, organic chemicals, pathogenic microorganisms (if present), and possibly radon are absorbed by the carbon filter. Plant roots and their associated microorganisms then destroy the pathogenic viruses, bacteria, and the organic chemicals, eventually converting all of these air pollutants into new plant tissue. It is believed that the decayed radon products would be taken up the plant roots and retained in the plant tissue.

Low pressure EGR system having full range capability

DOEpatents

Easley, Jr., William Lanier; Milam, David Michael; Roozenboom, Stephan Donald; Bond, Michael Steven; Kapic, Amir

2009-09-22

An exhaust treatment system for an engine is disclosed and may have an air induction circuit, an exhaust circuit, and an exhaust recirculation circuit. The air induction circuit may be configured to direct air into the engine. The exhaust circuit may be configured to direct exhaust from the engine and include a turbine driven by the exhaust, a particulate filter disposed in series with and downstream of the turbine, and a catalytic device disposed in series with and downstream of the particulate filter. The exhaust recirculation circuit may be configured to selectively redirect at least some of the exhaust from between the particulate filter and the catalytic device to the air induction circuit. The catalytic device is selected to create backpressure within the exhaust circuit sufficient to ensure that, under normal engine operating conditions above low idle, exhaust can flow into the air induction circuit without throttling of the air.

The impact of particle filtration on indoor air quality in a classroom near a highway.

PubMed

van der Zee, S C; Strak, M; Dijkema, M B A; Brunekreef, B; Janssen, N A H

2017-03-01

A pilot study was performed to investigate whether the application of a new mechanical ventilation system with a fine F8 (MERV14) filter could improve indoor air quality in a high school near the Amsterdam ring road. PM10, PM2.5, and black carbon (BC) concentrations were measured continuously inside an occupied intervention classroom and outside the school during three sampling periods in the winter of 2013/2014. Initially, 3 weeks of baseline measurements were performed, with the existing ventilation system and normal ventilation habits. Next, an intervention study was performed. A new ventilation system was installed in the classroom, and measurements were performed during 8 school weeks, in alternating 2-week periods with and without the filter in the ventilation system under otherwise identical ventilation conditions. Indoor/outdoor ratios measured during the weeks with filter were compared with those measured without filter to evaluate the ability of the F8 filter to improve indoor air quality. During teaching hours, the filter reduced BC exposure by, on average, 36%. For PM10 and PM2.5, a reduction of 34% and 30% was found, respectively. This implies that application of a fine filter can reduce the exposure of schoolchildren to traffic exhaust at hot spot locations by about one-third. © 2016 The Authors. Indoor Air published by John Wiley & Sons Ltd.

Microwave Bandpass Filter Based on Mie-Resonance Extraordinary Transmission

PubMed Central

Pan, Xiaolong; Wang, Haiyan; Zhang, Dezhao; Xun, Shuang; Ouyang, Mengzhu; Fan, Wentao; Guo, Yunsheng; Wu, Ye; Huang, Shanguo; Bi, Ke; Lei, Ming

2016-01-01

Microwave bandpass filter structure has been designed and fabricated by filling the periodically metallic apertures with dielectric particles. The microwave cannot transmit through the metallic subwavelength apertures. By filling the metallic apertures with dielectric particles, a transmission passband with insertion loss 2 dB appears at the frequency of 10–12 GHz. Both simulated and experimental results show that the passband is induced by the Mie resonance of the dielectric particles. In addition, the passband frequency can be tuned by the size and the permittivity of the dielectric particles. This approach is suitable to fabricate the microwave bandpass filters. PMID:27992440

A Dual Mode BPF with Improved Spurious Response Using DGS Cells Embedded on the Ground Plane of CPW

NASA Astrophysics Data System (ADS)

Weng, Min-Hang; Ye, Chang-Sin; Hung, Cheng-Yuan; Huang, Chun-Yueh

A novel dual mode bandpass filter (BPF) with improved spurious response is presented in this letter. To obtain low insertion loss, the coupling structure using the dual mode resonator and the feeding scheme using coplanar-waveguide (CPW) are constructed on the two sides of a dielectric substrate. A defected ground structure (DGS) is designed on the ground plane of the CPW to achieve the goal of spurious suppression of the filter. The filter has been investigated numerically and experimentally. Measured results show a good agreement with the simulated analysis.

Removal of residual particulate matter from filter media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almlie, Jay C.; Miller, Stanley J.

A method for removing residual filter cakes that remain adhered to a filter after typical particulate removal methodologies have been employed, such as pulse-jet filter element cleaning, for all cleanable filters used for air pollution control, dust control, or powder control.

Removal of residual particulate matter from filter media

DOEpatents

Almlie, Jay C; Miller, Stanley J

2014-11-11

A method for removing residual filter cakes that remain adhered to a filter after typical particulate removal methodologies have been employed, such as pulse-jet filter element cleaning, for all cleanable filters used for air pollution control, dust control, or powder control.

Inferior vena cava filters.

PubMed

Duffett, L; Carrier, M

2017-01-01

Use of inferior vena cava (IVC) filters has increased dramatically in recent decades, despite a lack of evidence that their use has impacted venous thromboembolism (VTE)-related mortality. This increased use appears to be primarily driven by the insertion of retrievable filters for prophylactic indications. A growing body of evidence, however, suggests that IVC filters are frequently associated with clinically important adverse events, prompting a closer look at their role. We sought to narratively review the current evidence on the efficacy and safety of IVC filter placements. Inferior vena cava filters remain the only treatment option for patients with an acute (within 2-4 weeks) proximal deep vein thrombosis (DVT) or pulmonary embolism and an absolute contraindication to anticoagulation. In such patients, anticoagulation should be resumed and IVC filters removed as soon as the contraindication has passed. For all other indications, there is insufficient evidence to support the use of IVC filters and high-quality trials are required. In patients where an IVC filter remains, regular follow-up to reassess removal and screen for filter-related complications should occur. © 2016 International Society on Thrombosis and Haemostasis.

Ultra-wideband ladder filter using SH(0) plate wave in thin LiNbO(3) plate and its application to tunable filter.

PubMed

Kadota, Michio; Tanaka, Shuji

2015-05-01

A cognitive radio terminal using vacant frequency bands of digital TV (DTV) channels, i.e., TV white space, strongly requires a compact tunable filter covering a wide frequency range of the DTV band (470 to 710 MHz in Japan). In this study, a T-type ladder filter using ultra-wideband shear horizontal mode plate wave resonators was fabricated, and a low peak insertion loss of 0.8 dB and an ultra-large 6 dB bandwidth of 240 MHz (41%) were measured in the DTV band. In addition, bandpass filters with different center frequencies of 502 and 653 MHz at 6 dB attenuation were numerically synthesized based on the same T-type ladder filter in conjunction with band rejection filters with different frequencies. The results suggest that the combination of the wideband T-type ladder filter and the band rejection filters connected with variable capacitors enables a tunable filter with large tunability of frequency and bandwidth as well as large rejection at the adjacent channels of an available TV white space.

Günther Tulip and Celect IVC filters in multiple-trauma patients.

PubMed

Rosenthal, David; Kochupura, Paul V; Wellons, Eric D; Burkett, Allison B; Methodius-Rayford, Walaya C

2009-08-01

To evaluate results with the retrievable Günther Tulip (GT) and Celect inferior vena cava filters (IVCFs) placed at the intensive care unit (ICU) bedside under "real-time" intravascular ultrasound (IVUS) guidance in multiple-trauma patients. Between December 2004 and December 2008, 187 multiple-trauma patients (109 men; mean age 44+/-2 years, range 17-71) with contraindications to low-dose anticoagulation therapy or sequential compression devices had Günther Tulip (n = 97) or Celect (n = 90) retrievable IVCFs placed under real-time IVUS guidance. Günther Tulip filters were inserted using a "double-puncture" technique. The Celect IVCFs were placed with a simplified single-puncture technique in which the filter introducer sheath was advanced until the radiopaque tip "covered" the IVUS image of the renal vein, indicating that the filter sheath was in position for filter deployment. The 2 filter groups were compared on the endpoints of technical implantation success, retrievability, prevention of PE, and procedure-related deep vein thrombosis (DVT). As verified by abdominal radiography, 93.1% (174/187) of IVCFs were placed without complications; 6 IVCFs (all GT; p = 0.03 versus Celect) were misplaced in the iliac vein but uneventfully retrieved and replaced in the IVC within 24 hours. Two insertion site femoral vein DVTs (both in the dual puncture group; p>0.2) and 5 groin hematomas occurred during follow-up. GT filters were in place a mean of 107 days and Celect 97 days. In this time, 2 pulmonary embolisms occurred (1 in each group; p>0.2). Of the 115 filters scheduled for retrieval (50 Günther Tulip, 65 Celect), 33 (23 Günther Tulip, 10 Celect) could not be retrieved (p = 0.0004). Vena cavography identified filter tilting (>20 degrees ) in 21 cases (15 GT, 6 Celect), while 12 filters (8 GT, 4 Celect) had extended indwell times (mean 187 days) and excessive tissue ingrowth covering the retrieval hook. Subjectively, the Celect filters were clinically "easier" to retrieve; they also had fewer cases of significant tilt (>20%) than the GT filters, but the difference was not statistically significant. GT and Celect IVCFs placed at the ICU bedside under IVUS guidance in multiple-trauma patients was simple, safe, and avoided transporting critically ill patients out of the ICU. Further investigation of the single sheath IVUS technique and the role of retrievable IVCFs in multi-trauma patients is warranted.

Risks and benefits of prophylactic inferior vena cava filters in patients undergoing bariatric surgery.

PubMed

Birkmeyer, Nancy J; Finks, Jonathan F; English, Wayne J; Carlin, Arthur M; Hawasli, Abdelkader A; Genaw, Jeffrey A; Wood, Michael H; Share, David A; Birkmeyer, John D

2013-04-01

The United States Food and Drug Administration recently issued a warning about adverse events in patients receiving inferior vena cava (IVC) filters. To assess relationships between IVC filter insertion and complications while controlling for differences in baseline patient characteristics and medical venous thromboembolism prophylaxis. Propensity-matched cohort study. The prospective, statewide, clinical registry of the Michigan Bariatric Surgery Collaborative. Bariatric surgery patients (n=35,477) from 32 hospitals during the years 2006 through 2012. Prophylactic IVC filter insertion. Outcomes included the occurrence of complications (pulmonary embolism, deep vein thrombosis, and overall combined rates of complications by severity) within 30 days of bariatric surgery. There were no significant differences in baseline characteristics among the 1,077 patients with IVC filters and in 1,077 matched control patients. Patients receiving IVC filters had higher rates of pulmonary embolism (0.84% vs 0.46%; odds ratio [OR], 2.0; 95% confidence interval [CI], 0.6-6.5; P=0.232), deep vein thrombosis (1.2% vs 0.37%; OR, 3.3; 95% CI, 1.1-10.1; P=0.039), venous thromboembolism (1.9% vs 0.74%; OR, 2.7; 95% CI, 1.1-6.3, P=0.027), serious complications (5.8% vs 3.8%; OR, 1.6; 95% CI, 1.0-2.4; P=0.031), permanently disabling complications (1.2% vs 0.37%; OR, 4.3; 95% CI, 1.2-15.6; P=0.028), and death (0.7% vs 0.09%; OR, 7.0; 95% CI, 0.9-57.3; P=0.068). Of the 7 deaths among patients with IVC filters, 4 were attributable to pulmonary embolism and 2 to IVC thrombosis/occlusion. We have identified no benefits and significant risks to the use of prophylactic IVC filters among bariatric surgery patients and believe that their use should be discouraged. Copyright © 2013 Society of Hospital Medicine.

A 96-well screen filter plate for high-throughput biological sample preparation and LC-MS/MS analysis.

PubMed

Peng, Sean X; Cousineau, Martin; Juzwin, Stephen J; Ritchie, David M

2006-01-01

A novel 96-well screen filter plate (patent pending) has been invented to eliminate a time-consuming and labor-intensive step in preparation of in vivo study samples--to remove blood or plasma clots. These clots plug the pipet tips during a manual or automated sample-transfer step causing inaccurate pipetting or total pipetting failure. Traditionally, these blood and plasma clots are removed by picking them out manually one by one from each sample tube before any sample transfer can be made. This has significantly slowed the sample preparation process and has become a bottleneck for automated high-throughput sample preparation using robotic liquid handlers. Our novel screen filter plate was developed to solve this problem. The 96-well screen filter plate consists of 96 stainless steel wire-mesh screen tubes connected to the 96 openings of a top plate so that the screen filter plate can be readily inserted into a 96-well sample storage plate. Upon insertion, the blood and plasma clots are excluded from entering the screen tube while clear sample solutions flow freely into it. In this way, sample transfer can be easily completed by either manual or automated pipetting methods. In this report, three structurally diverse compounds were selected to evaluate and validate the use of the screen filter plate. The plasma samples of these compounds were transferred and processed in the presence and absence of the screen filter plate and then analyzed by LC-MS/MS methods. Our results showed a good agreement between the samples prepared with and without the screen filter plate, demonstrating the utility and efficiency of this novel device for preparation of blood and plasma samples. The device is simple, easy to use, and reusable. It can be employed for sample preparation of other biological fluids that contain floating particulates or aggregates.

Simultaneous sampling of indoor and outdoor airborne radioactivity after the Fukushima Daiichi nuclear power plant accident.

PubMed

Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Arae, Hideki; Sahoo, Sarata Kumar; Janik, Miroslaw; Hosoda, Masahiro; Tokonami, Shinji

2014-02-18

Several studies have estimated inhalation doses for the public because of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Most of them were based on measurement of radioactivity in outdoor air and included the assumption that people stayed outdoors all day. Although this assumption gives a conservative estimate, it is not realistic. The "air decontamination factor" (ratio of indoor to outdoor air radionuclide concentrations) was estimated from simultaneous sampling of radioactivity in both inside and outside air of one building. The building was a workplace and located at the National Institute of Radiological Sciences (NIRS) in Chiba Prefecture, Japan. Aerosol-associated radioactive materials in air were collected onto filters, and the filters were analyzed by γ spectrometry at NIRS. The filter sampling was started on March 15, 2011 and was continued for more than 1 year. Several radionuclides, such as (131)I, (134)Cs, and (137)Cs were found by measuring the filters with a germanium detector. The air decontamination factor was around 0.64 for particulate (131)I and 0.58 for (137)Cs. These values could give implications for the ratio of indoor to outdoor radionuclide concentrations after the FDNPP accident for a similar type of building.

[Research on dust mite allergen gathered from filters of air-conditioners].

PubMed

Zhan, Xiao-dong; Wu, Hua; Hu, Hui-min; Li, Chao-pin

2015-12-01

To discuss the relation between the dust mite allergen (Der) in air-conditioner filters and the asthma attack. The dust samples were collected from the filters of air-conditioners in dining rooms, shopping malls, hotels and households, respectively. The concentrations of Der f 1 and Der p1 were detected by ELISA, and the dust mite immune activities were determined by dot-ELISA. The concentrations of Der f 1 in the dining rooms, shopping malls, hotels and households were 1.52, 1.24, 1.31 µg/g and 1.46 µg/g respectively, and the concentrations of Der p 1 were 1.23, 1.12, 1.16 µg/ g and 1.18 µg, respectively. One hour after the running of air-conditioners, the concentrations of Der f 1 and Der p 1 in the air were higher than those before the running of air-conditioners, and the differences were significant (P < 0.05). Additionally, the dot-ELISA results revealed that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. Der f 1 and Der p 1 appear abundantly in the filters of air-conditioners in domestic houses in Wuhu City, and the allergens can induce asthma.

Combining tissue-phantom ratios to provide a beam-quality specifier for flattening filter free photon beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dalaryd, Mårten, E-mail: Marten.Dalaryd@med.lu.se; Knöös, Tommy; Ceberg, Crister

Purpose: There are currently several commercially available radiotherapy treatment units without a flattening filter in the beam line. Unflattened photon beams have an energy and lateral fluence distribution that is different from conventional beams and, thus, their attenuation properties differ. As a consequence, for flattening filter free (FFF) beams, the relationship between the beam-quality specifier TPR{sub 20,10} and the Spencer–Attix restricted water-to-air mass collision stopping-power ratios, (L{sup -}/ρ){sub air}{sup water}, may have to be refined in order to be used with equivalent accuracy as for beams with a flattening filter. The purpose of this work was twofold. First, to studymore » the relationship between TPR{sub 20,10} and (L{sup -}/ρ){sub air}{sup water} for FFF beams, where the flattening filter has been replaced by a metal plate as in most clinical FFF beams. Second, to investigate the potential of increasing the accuracy in determining (L{sup -}/ρ){sub air}{sup water} by adding another beam-quality metric, TPR{sub 10,5}. The relationship between (L{sup -}/ρ){sub air}{sup water} and %dd(10){sub x} for beams with and without a flattening filter was also included in this study. Methods: A total of 24 realistic photon beams (10 with and 14 without a flattening filter) from three different treatment units have been used to calculate (L{sup -}/ρ){sub air}{sup water}, TPR{sub 20,10}, and TPR{sub 10,5} using the EGSnrc Monte Carlo package. The relationship between (L{sup -}/ρ){sub air}{sup water} and the dual beam-quality specifier TPR{sub 20,10} and TPR{sub 10,5} was described by a simple bilinear equation. The relationship between the photon beam-quality specifier %dd(10){sub x} used in the AAPM’s TG-51 dosimetry protocol and (L{sup -}/ρ){sub air}{sup water} was also investigated for the beams used in this study, by calculating the photon component of the percentage depth dose at 10 cm depth with SSD 100 cm. Results: The calculated (L{sup -}/ρ){sub air}{sup water} for beams without a flattening filter was 0.3% lower, on average, than for beams with a flattening filter and comparable TPR{sub 20,10}. Using the relationship in IAEA, TRS-398 resulted in a root mean square deviation (RMSD) of 0.0028 with a maximum deviation of 0.0043 (0.39%) from Monte Carlo calculated values. For all beams in this study, the RMSD between the proposed model and the Monte Carlo calculated values was 0.0006 with a maximum deviation of 0.0013 (0.1%). Using an earlier proposed relationship [Xiong and Rogers, Med. Phys. 35, 2104–2109 (2008)] between %dd(10){sub x} and (L{sup -}/ρ){sub air}{sup water} gave a RMSD of 0.0018 with a maximum deviation of 0.0029 (0.26%) for all beams in this study (compared to RMSD 0.0015 and a maximum deviation of 0.0048 (0.47%) for the relationship used in AAPM TG-51 published by Almond et al. [Med. Phys. 26, 1847–1870 (1999)]). Conclusions: Using TPR{sub 20,10} as a beam-quality specifier, for the flattening filter free beams used in this study, gave a maximum difference of 0.39% between (L{sup -}/ρ){sub air}{sup water} predicted using IAEA TRS-398 and Monte Carlo calculations. An additional parameter for determining (L{sup -}/ρ){sub air}{sup water} has been presented. This parameter is easy to measure; it requires only an additional dose measurement at 5 cm depth with SSD 95 cm, and provides information for accurate determination of the (L{sup -}/ρ){sub air}{sup water} ratio for beams both with and without a flattening filter at the investigated energies.« less

Percutaneous Venous Thrombectomy Using the Arrow-Trerotola Percutaneous Thrombolytic Device (PTD) with Temporary Caval Filtration: In Vitro Investigations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wildberger, Joachim Ernst, E-mail: wildberg@rad.rwth-aachen.de; Haage, Patrick; Bovelander, Jan

2005-04-15

Purpose. To evaluate the size and quantity of downstream emboli after thrombectomy using the Arrow-Trerotola Percutaneous Thrombolytic Device (PTD) with or without temporary filtration for extensive iliofemoral and iliocaval thrombi in an in vitro flow model. Methods. Iliocaval thrombi were simulated by clotted bovine blood in a flow model (semilucent silicone tubings, diameter 12-16 mm). Five experimental set-ups were performed 10 times each; thrombus particles and distribution were measured in the effluent. First, after retrograde insertion, mechanical thrombectomy was performed using the PTD alone. Then a modified self-expanding tulip-shaped temporary vena cava stent filter was inserted additionally at the beginningmore » of each declotting procedure and removed immediately after the intervention without any manipulation within or at the filter itself. In a third step, the filter was filled with thrombus only. Here, two experiments were performed: Careful closure within the flow circuit without any additional fragmentation procedure and running the PTD within the filter lumen, respectively. In the final set-up, mechanical thrombectomy was performed within the thrombus-filled tubing as well as in the filter lumen. The latter was closed at the end of the procedure and both devices were removed from the flow circuit. Results. Running the PTD in the flow circuit without filter protection led to a fragmentation of 67.9% ({+-}7.14%) of the clot into particles {<=}500 {mu}m; restoration of flow was established in all cases. Additional placement of the filter safely allowed maceration of 82.9% ({+-}5.59%) of the thrombus. Controlled closure of the thrombus-filled filter within the flow circuit without additional mechanical treatment broke up 75.2% ({+-}10.49%), while additional mechanical thrombectomy by running the PTD within the occluded filter led to dissolution of 90.4% ({+-}3.99%) of the initial clot. In the final set-up, an overall fragmentation rate of 99.6% ({+-}0.44%) was achieved. Conclusions. The combined use of the Arrow-Trerotola PTD and a temporary vena cava stent filter proved to be effective for even large clot removal in this experimental set-up.« less

Semi-volatile organic compounds in heating, ventilation, and air-conditioning filter dust in retail stores.

PubMed

Xu, Y; Liang, Y; Urquidi, J R; Siegel, J A

2015-02-01

Retail stores contain a wide range of products that can emit a variety of indoor pollutants. Among these chemicals, phthalate esters and polybrominated diphenyl ethers (PBDEs) are two important categories of semi-volatile organic compounds (SVOCs). Filters in heating, ventilation, and air-conditioning (HVAC) system collect particles from large volumes of air and thus potentially provide spatially and temporally integrated SVOC concentrations. This study measured six phthalate and 14 PBDE compounds in HVAC filter dust in 14 retail stores in Texas and Pennsylvania, United States. Phthalates and PBDEs were widely found in the HVAC filter dust in retail environment, indicating that they are ubiquitous indoor pollutants. The potential co-occurrence of phthalates and PBDEs was not strong, suggesting that their indoor sources are diverse. The levels of phthalates and PBDEs measured in HVAC filter dust are comparable to concentrations found in previous investigations of settled dust in residential buildings. Significant correlations between indoor air and filter dust concentrations were found for diethyl phthalate, di-n-butyl phthalate, and benzyl butyl phthalate. Reasonable agreement between measurements and an equilibrium model to describe SVOC partitioning between dust and gas-phase is achieved. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparative Efficacy of the Air-Q Intubating Laryngeal Airway during General Anesthesia in Pediatric Patients: A Systematic Review and Meta-Analysis.

PubMed

Ahn, Eun Jin; Choi, Geun Joo; Kang, Hyun; Baek, Chong Wha; Jung, Yong Hun; Woo, Young Cheol; Bang, Si Ra

2016-01-01

Air-Q® (air-Q) is a supraglottic airway device which can be used as a guidance of intubation in pediatric as well as in adult patients. We evaluated the efficacy and safety of air-Q compared to other airway devices during general anesthesia in pediatric patients by conducting a systematic review and meta-analysis. A total of 10 studies including 789 patients were included in the final analysis. Compared with other supraglottic airway devices, air-Q showed no evidence for a difference in leakage pressure and insertion time. The ease of insertion was significantly lower than other supraglottic airway devices. The success rate of intubation was significantly lower than other airway devices. However, fiberoptic view was better through the air-Q than other supraglottic airway devices. Therefore, air-Q could be a safe substitute for other airway devices and may provide better fiberoptic bronchoscopic view.

[Wrong connection of a flexible medical air hose to a nitrous oxide outlet caused by a defective safety device].

PubMed

Nicaise, C; Robert, C; Ancellin, J; Cazalaà, J B

1996-01-01

When plugging the O2, N2O and air hoses into the corresponding wall sockets, the air hose was wrongly inserted into the N2O wall outlet. This was made possible because of faulty retaining clasps of the male coupler of the air probe. French "fail-safe" connections consist of a two-clasp male coupler for air, three clasps for O2 and four clasps for N2O hoses. Additionally the clasps of the air probe are broader then those of the N2O probe. However, the latter difference was lost due to wear. The incident was recognized without delay as the N2O hose could not be inserted into the air outlet. However, it could have remained unnoticed had there been two N2O wall outlets and could have resulted in severe adverse effects.

Emergency sacrificial sealing method in filters, equipment, or systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Erik P.

A system seals a filter or equipment component to abase and will continue to seal the filter or equipment component to the base in the event of hot air or fire. The system includes a first sealing material between the filter or equipment component and the base; and a second sealing material between the filter or equipment component and the base and proximate the first sealing material. The first sealing material and the second seal material are positioned relative to each other and relative to the filter or equipment component and the base to seal the filter or equipment componentmore » to the base and upon the event of fire the second sealing material will be activated and expand to continue to seal the filter or equipment component to the base in the event of hot air or fire.« less

Method and apparatus for assembling solid oxide fuel cells

DOEpatents

Szreders, Bernard E.; Campanella, Nicholas

1989-01-01

A plurality of jet air tubes are supported and maintained in a spaced matrix array by a positioning/insertion assembly for insertion in respective tubes of a solid oxide fuel cell (SOFC) in the assembly of an SOFC module. The positioning/insertion assembly includes a plurality of generally planar, elongated, linear vanes which are pivotally mounted at each end thereof to a support frame. The vanes, which each include a plurality of spaced slots along the facing edges thereof, may be pivotally displaced from a generally vertical orientation, wherein each jet air tube is positioned within and engaged by the aligned slots of a plurality of paired upper and lower vanes to facilitate their insertion in respective aligned SOFC tubes arranged in a matrix array, to an inclined orientation, wherein the jet air tubes may be removed from the positioning/insertion assembly after being inserted in the SOFC tubes. A rectangular compression assembly of adjustable size is adapted to receive and squeeze a matrix of SOFC tubes so as to compress the inter-tube nickel felt conductive pads which provide series/parallel electrical connection between adjacent SOFCs, with a series of increasingly larger retainer frames used to maintain larger matrices of SOFC tubes in position. Expansion of the SOFC module housing at the high operating temperatures of the SOFC is accommodated by conductive, flexible, resilient expansion, connector bars which provide support and electrical coupling at the top and bottom of the SOFC module housing.

Impact of backwashing procedures on deep bed filtration productivity in drinking water treatment.

PubMed

Slavik, Irene; Jehmlich, Alexander; Uhl, Wolfgang

2013-10-15

Backwash procedures for deep bed filters were evaluated and compared by means of a new integrated approach based on productivity. For this, different backwash procedures were experimentally evaluated by using a pilot plant for direct filtration. A standard backwash mode as applied in practice served as a reference and effluent turbidity was used as the criterion for filter run termination. The backwash water volumes needed, duration of the filter-to-waste period, time out of operation, total volume discharged and filter run-time were determined and used to calculate average filtration velocity and average productivity. Results for filter run-times, filter backwash volumes, and filter-to-waste volumes showed considerable differences between the backwash procedures. Thus, backwash procedures with additional clear flushing phases were characterised by an increased need for backwash water. However, this additional water consumption could not be compensated by savings during filter ripening. Compared to the reference backwash procedure, filter run-times were longer for both single-media and dual-media filters when air scour and air/water flush were optimised with respect to flow rates and the proportion of air and water. This means that drinking water production time is longer and less water is needed for filter bed cleaning. Also, backwashing with additional clear flushing phases resulted in longer filter run-times before turbidity breakthrough. However, regarding the productivity of the filtration process, it was shown that it was almost the same for all of the backwash procedures investigated in this study. Due to this unexpected finding, the relationships between filter bed cleaning, filter ripening and filtration performance were considered and important conclusions and new approaches for process optimisation and resource savings were derived. Copyright © 2013 Elsevier Ltd. All rights reserved.

Particle Concentrations and Effectiveness of Free-Standing Air Filters in Bedrooms of Children with Asthma in Detroit, Michigan

PubMed Central

Du, Liuliu; Batterman, Stuart; Parker, Edith; Godwin, Christopher; Chin, Jo-Yu; O'Toole, Ashley; Robins, Thomas; Brakefield-Caldwell, Wilma; Lewis, Toby

2011-01-01

Asthma can be exacerbated by environmental factors including airborne particulate matter (PM) and environmental tobacco smoke (ETS). We report on a study designed to characterize PM levels and the effectiveness of filters on pollutant exposures of children with asthma. 126 households with an asthmatic child in Detroit, Michigan, were recruited and randomized into control or treatment groups. Both groups received asthma education; the latter also received a free-standing high efficiency air filter placed in the child’s bedroom. Information regarding the home, emission sources, and occupant activities was obtained using surveys administered to the child's caregiver and a household inspection. Over a one-week period, we measured PM, carbon dioxide (CO2), environmental tobacco smoke (ETS) tracers, and air exchange rates (AERs). Filters were installed at midweek. Before filter installation, PM concentrations averaged 28 µg m−3, number concentrations averaged 70,777 and 1,471 L−1 in 0.3–1.0 and 1–5 µm size ranges, respectively, and the median CO2 concentration was 1,018 ppm. ETS tracers were detected in 23 of 38 homes where smoking was unrestricted and occupants included smokers and, when detected, PM concentrations were elevated by an average of 15 µg m−3. Filter use reduced PM concentrations by an average of 69 to 80%. Simulation models representing location conditions show that filter air flow, room volume and AERs are the key parameters affecting PM removal, however, filters can achieve substantial removal in even "worst" case applications. While PM levels in homes with asthmatic children can be high, levels can be dramatically reduced using filters. PMID:21874085

Particle Concentrations and Effectiveness of Free-Standing Air Filters in Bedrooms of Children with Asthma in Detroit, Michigan.

PubMed

Du, Liuliu; Batterman, Stuart; Parker, Edith; Godwin, Christopher; Chin, Jo-Yu; O'Toole, Ashley; Robins, Thomas; Brakefield-Caldwell, Wilma; Lewis, Toby

2011-10-01

Asthma can be exacerbated by environmental factors including airborne particulate matter (PM) and environmental tobacco smoke (ETS). We report on a study designed to characterize PM levels and the effectiveness of filters on pollutant exposures of children with asthma. 126 households with an asthmatic child in Detroit, Michigan, were recruited and randomized into control or treatment groups. Both groups received asthma education; the latter also received a free-standing high efficiency air filter placed in the child's bedroom. Information regarding the home, emission sources, and occupant activities was obtained using surveys administered to the child's caregiver and a household inspection. Over a one-week period, we measured PM, carbon dioxide (CO(2)), environmental tobacco smoke (ETS) tracers, and air exchange rates (AERs). Filters were installed at midweek. Before filter installation, PM concentrations averaged 28 µg m(-3), number concentrations averaged 70,777 and 1,471 L(-1) in 0.3-1.0 and 1-5 µm size ranges, respectively, and the median CO(2) concentration was 1,018 ppm. ETS tracers were detected in 23 of 38 homes where smoking was unrestricted and occupants included smokers and, when detected, PM concentrations were elevated by an average of 15 µg m(-3). Filter use reduced PM concentrations by an average of 69 to 80%. Simulation models representing location conditions show that filter air flow, room volume and AERs are the key parameters affecting PM removal, however, filters can achieve substantial removal in even "worst" case applications. While PM levels in homes with asthmatic children can be high, levels can be dramatically reduced using filters.

Reducing patients' exposures to asthma and allergy triggers in their homes: an evaluation of effectiveness of grades of forced air ventilation filters.

PubMed

Brown, Kathleen Ward; Minegishi, Taeko; Allen, Joseph G; McCarthy, John F; Spengler, John D; MacIntosh, David L

2014-08-01

Many interventions to reduce allergen levels in the home are recommended to asthma and allergy patients. One that is readily available and can be highly effective is the use of high performing filters in forced air ventilation systems. We conducted a modeling analysis of the effectiveness of filter-based interventions in the home to reduce airborne asthma and allergy triggers. This work used "each pass removal efficiency" applied to health-relevant size fractions of particles to assess filter performance. We assessed effectiveness for key allergy and asthma triggers based on applicable particle sizes for cat allergen, indoor and outdoor sources of particles <2.5 µm in diameter (PM2.5), and airborne influenza and rhinovirus. Our analysis finds that higher performing filters can have significant impacts on indoor particle pollutant levels. Filters with removal efficiencies of >70% for cat dander particles, fine particulate matter (PM2.5) and respiratory virus can lower concentrations of those asthma triggers and allergens in indoor air of the home by >50%. Very high removal efficiency filters, such as those rated a 16 on the nationally recognized Minimum Efficiency Removal Value (MERV) rating system, tend to be only marginally more effective than MERV12 or 13 rated filters. The results of this analysis indicate that use of a MERV12 or higher performing air filter in home ventilation systems can effectively reduce indoor levels of these common asthma and allergy triggers. These reductions in airborne allergens in turn may help reduce allergy and asthma symptoms, especially if employed in conjunction with other environmental management measures recommended for allergy and asthma patients.

Reducing patients’ exposures to asthma and allergy triggers in their homes: an evaluation of effectiveness of grades of forced air ventilation filters

PubMed Central

Minegishi, Taeko; Allen, Joseph G.; McCarthy, John F.; Spengler, John D.; MacIntosh, David L.

2014-01-01

Objective Many interventions to reduce allergen levels in the home are recommended to asthma and allergy patients. One that is readily available and can be highly effective is the use of high performing filters in forced air ventilation systems. Methods We conducted a modeling analysis of the effectiveness of filter-based interventions in the home to reduce airborne asthma and allergy triggers. This work used “each pass removal efficiency” applied to health-relevant size fractions of particles to assess filter performance. We assessed effectiveness for key allergy and asthma triggers based on applicable particle sizes for cat allergen, indoor and outdoor sources of particles <2.5 µm in diameter (PM2.5), and airborne influenza and rhinovirus. Results Our analysis finds that higher performing filters can have significant impacts on indoor particle pollutant levels. Filters with removal efficiencies of >70% for cat dander particles, fine particulate matter (PM2.5) and respiratory virus can lower concentrations of those asthma triggers and allergens in indoor air of the home by >50%. Very high removal efficiency filters, such as those rated a 16 on the nationally recognized Minimum Efficiency Removal Value (MERV) rating system, tend to be only marginally more effective than MERV12 or 13 rated filters. Conclusions The results of this analysis indicate that use of a MERV12 or higher performing air filter in home ventilation systems can effectively reduce indoor levels of these common asthma and allergy triggers. These reductions in airborne allergens in turn may help reduce allergy and asthma symptoms, especially if employed in conjunction with other environmental management measures recommended for allergy and asthma patients. PMID:24555523

78 FR 27951 - Foreign-Trade Zone (FTZ) 75-Phoenix, Arizona; Notification of Proposed Production Activity...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-13

... systems; duct temperature limiters; air/oil heat exchangers; oil cooler fans; fuel filter assemblies... assemblies; filter extractors; de- coupler/disassembly wrenches; torque wrench adaptors; test benches; drills...; filter assemblies; oil filter install kits; cartridge screens; filter housings; trim balance weights...

Self-Cleaning Particulate Prefilter Media

NASA Technical Reports Server (NTRS)

Weber, Olivia; Lalwani, San-jiv; Sharma, Anjal

2012-01-01

A long-term space mission requires efficient air revitalization performance to sustain the crew. Prefilter and particulate air filter media are susceptible to rapid fouling that adversely affects their performance and can lead to catastrophic failure of the air revitalization system, which may result in mission failure. For a long-term voyage, it is impractical to carry replacement particulate prefilter and filter modules due to the usual limitations in size, volume, and weight. The only solution to this problem is to reagentlessly regenerate prefilter and filter media in place. A method was developed to modify the particulate prefilter media to allow them to regenerate reagentlessly, and in place, by the application of modest thermocycled transverse or reversed airflows. The innovation may allow NASA to close the breathing air loop more efficiently, thereby sustaining the vision for manned space exploration missions of the future. A novel, self-cleaning coatings technology was developed for air filter media surfaces that allows reagentless in-place regeneration of the surface. The technology grafts thermoresponsive and nonspecific adhesion minimizing polymer nanolayer brush coatings from the prefilter media. These polymer nanolayer brush architectures can be triggered to contract and expand to generate a "pushing-off" force by the simple application of modestly thermocycled (i.e. cycling from ambient cabin temperature to 40 C) air streams. The nonspecific adhesion-minimizing properties of the coatings do not allow the particulate foulants to adhere strongly to the filter media, and thermocycled air streams applied to the media allow easy detachment and in-place regeneration of the media with minimal impact in system downtime or astronaut involvement in overseeing the process.

Wood dust particle and mass concentrations and filtration efficiency in sanding of wood materials.

PubMed

Welling, Irma; Lehtimäki, Matti; Rautio, Sari; Lähde, Tero; Enbom, Seppo; Hynynen, Pasi; Hämeri, Kaarle

2009-02-01

The importance of fine particles has become apparent as the knowledge of their effects on health has increased. Fine particle concentrations have been published for outside air, plasma arc cutting, welding, and grinding, but little data exists for the woodworking industry. Sanding was evaluated as the producer of the woodworking industry's finest particles, and was selected as the target study. The number of dust particles in different particle size classes and the mass concentrations were measured in the following environments: workplace air during sanding in plywood production and in the inlet and return air; in the dust emission chamber; and in filter testing. The numbers of fine particles were low, less than 10(4) particles/cm(3) (10(7) particles/L). They were much lower than typical number concentrations near 10(6) particles/cm(3) measured in plasma arc cutting, grinding, and welding. Ultrafine particles in the size class less than 100 nm were found during sanding of MDF (medium density fiberboard) sheets. When the cleaned air is returned to the working areas, the dust content in extraction systems must be monitored continuously. One way to monitor the dust content in the return air is to use an after-filter and measure pressure drop across the filter to indicate leaks in the air-cleaning system. The best after-filtration materials provided a clear increase in pressure drop across the filter in the loading of the filter. The best after-filtration materials proved to be quite effective also for fine particles. The best mass removal efficiencies for fine particles around 0.3 mum were over 80% for some filter materials loaded with sanding wood dust.

Relationship between product demand, tibial polyethylene insert shelf age, and total knee arthroplasty survival: retrospective review of total knees of one design.

PubMed

Urban, Joshua A; Collier, Matthew B; Engh, C Anderson; Engh, Gerard A

2006-04-01

Shelf aging of gamma-irradiated-in-air polyethylene tibial components has been associated with increased articular surface wear and an elevated risk for revision. Nine hundred fifty cruciate-retaining inserts of one design were implanted between 1987 and 1996 (shelf age, 1.0 +/- 1.2 years). Less frequently used inserts (smallest/largest sizes, thicker thicknesses, supplemental articular constraint) had longer shelf ages (means ranged from 1.2 to 2.6 years). Survival analysis showed that shelf age (P < .01) and gamma-sterilization in air (P = .01) elevated the risk for revision. Surgeons must remain attentive to identify the shelf-aged gamma-irradiated-in-air polyethylene tibial component while following designs from the era when this sterilization method was used. Recognition is expedited by understanding how shelf life is related to product demand and can be of aid when diagnosing the painful knee.

Preliminary design of the spatial filters used in the multipass amplification system of TIL

NASA Astrophysics Data System (ADS)

Zhu, Qihua; Zhang, Xiao Min; Jing, Feng

1998-12-01

The spatial filters are used in Technique Integration Line, which has a multi-pass amplifier, not only to suppress parasitic high spatial frequency modes but also to provide places for inserting a light isolator and injecting the seed beam, and to relay image while the beam passes through the amplifiers several times. To fulfill these functions, the parameters of the spatial filters are optimized by calculations and analyzes with the consideration of avoiding the plasma blow-off effect and components demanding by ghost beam focus. The 'ghost beams' are calculated by ray tracing. A software was developed to evaluate the tolerance of the spatial filters and their components, and to align the whole system on computer simultaneously.

76 FR 49303 - Approval and Promulgation of Air Quality Implementation Plans; Minnesota; Rules Update

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-10

... design requirements for the monitoring systems. The revised CMS rules also delineate the recordkeeping..., [Insert page number where the document begins]. 7017.1140 CEMS design 03/01/99 08/10/11, [Insert page...]. 7017.1190 COMS design 03/01/99 08/10/11, [Insert page requirements. number where the document begins...

Experimental Study on Ultrafine Particle Removal Performance of Portable Air Cleaners with Different Filters in an Office Room

PubMed Central

Ma, Huan; Shen, Henggen; Shui, Tiantian; Li, Qing; Zhou, Liuke

2016-01-01

Size- and time-dependent aerodynamic behaviors of indoor particles, including PM1.0, were evaluated in a school office in order to test the performance of air-cleaning devices using different filters. In-situ real-time measurements were taken using an optical particle counter. The filtration characteristics of filter media, including single-pass efficiency, volume and effectiveness, were evaluated and analyzed. The electret filter (EE) medium shows better initial removal efficiency than the high efficiency (HE) medium in the 0.3–3.5 μm particle size range, while under the same face velocity, the filtration resistance of the HE medium is several times higher than that of the EE medium. During service life testing, the efficiency of the EE medium decreased to 60% with a total purifying air flow of 25 × 104 m3/m2. The resistance curve rose slightly before the efficiency reached the bottom, and then increased almost exponentially. The single-pass efficiency of portable air cleaner (PAC) with the pre-filter (PR) or the active carbon granule filter (CF) was relatively poor. While PAC with the pre-filter and the high efficiency filter (PR&HE) showed maximum single-pass efficiency for PM1.0 (88.6%), PAC with the HE was the most effective at removing PM1.0. The enhancement of PR with HE and electret filters augmented the single-pass efficiency, but lessened the airflow rate and effectiveness. Combined with PR, the decay constant of large-sized particles could be greater than for PACs without PR. Without regard to the lifetime, the electret filters performed better with respect to resource saving and purification improvement. A most penetrating particle size range (MPPS: 0.4–0.65 μm) exists in both HE and electret filters; the MPPS tends to become larger after HE and electret filters are combined with PR. These results serve to provide a better understanding of the indoor particle removal performance of PACs when combined with different kinds of filters in school office buildings. PMID:26742055

Fabrication of an anti-viral air filter with SiO₂-Ag nanoparticles and performance evaluation in a continuous airflow condition.

PubMed

Joe, Yun Haeng; Woo, Kyoungja; Hwang, Jungho

2014-09-15

In this study, SiO2 nanoparticles surface coated with Ag nanoparticles (SA particles) were fabricated to coat a medium air filter. The pressure drop, filtration efficiency, and anti-viral ability of the filter were evaluated against aerosolized bacteriophage MS2 in a continuous air flow condition. A mathematical approach was developed to measure the anti-viral ability of the filter with various virus deposition times. Moreover, two quality factors based on the anti-viral ability of the filter, and a traditional quality factor based on filtration efficiency, were calculated. The filtration efficiency and pressure drop increased with decreasing media velocity and with increasing SA particle coating level. The anti-viral efficiency also increased with increasing SA particle coating level, and decreased by with increasing virus deposition time. Consequently, SA particle coating on a filter does not have significant effects on filtration quality, and there is an optimal coating level to produce the highest anti-viral quality. Copyright © 2014 Elsevier B.V. All rights reserved.

The Fate of Mengovirus on Fiberglass Filter of Air Handling Units.

PubMed

Bandaly, Victor; Joubert, Aurélie; Le Cann, Pierre; Andres, Yves

2017-12-01

One of the most important topics that occupy public health problems is the air quality. That is the reason why mechanical ventilation and air handling units (AHU) were imposed by the different governments in the collective or individual buildings. Many buildings create an artificial climate using heating, ventilation, and air-conditioning systems. Among the existing aerosols in the indoor air, we can distinguish the bioaerosol with biological nature such as bacteria, viruses, and fungi. Respiratory viral infections are a major public health issue because they are usually highly infective. We spend about 90% of our time in closed environments such as homes, workplaces, or transport. Some studies have shown that AHU contribute to the spread and transport of viral particles within buildings. The aim of this work is to study the characterization of viral bioaerosols in indoor environments and to understand the fate of mengovirus eukaryote RNA virus on glass fiber filter F7 used in AHU. In this study, a set-up close to reality of AHU system was used. The mengovirus aerosolized was characterized and measured with the electrical low pressure impact and the scanner mobility particle size and detected with RT-qPCR. The results about quantification and the level of infectivity of mengovirus on the filter and in the biosampler showed that mengovirus can pass through the filter and remain infectious upstream and downstream the system. Regarding the virus infectivity on the filter under a constant air flow, mengovirus was remained infectious during 10 h after aerosolization.

Critically safe vacuum pickup for use in wet or dry cleanup of radioactive materials

DOEpatents

Zeren, Joseph D.

1994-01-01

A vacuum pickup of critically safe quantity and geometric shape is used in cleanup of radioactive materials. Collected radioactive material is accumulated in four vertical, parallel, equally spaced canisters arranged in a cylinder configuration. Each canister contains a filter bag. An upper intake manifold includes four 90 degree spaced, downward facing nipples. Each nipple communicates with the top of a canister. The bottom of each canister communicates with an exhaust manifold comprising four radially extending tubes that meet at the bottom of a centrally located vertical cylinder. The top of the central cylinder terminates at a motor/fan power head. A removable HEPA filter is located intermediate the top of the central cylinder and the power head. Four horizontal bypass tubes connect the top of the central cylinder to the top of each of the canisters. Air enters the vacuum cleaner via a hose connected to the intake manifold. Air then travels down the canisters, where particulate material is accumulated in generally equal quantities in each filter bag. Four air paths of bag filtered air then pass radially inward to the bottom of the central cylinder. Air moves up the central cylinder, through the HEPA filter, through a vacuum fan compartment, and exits the vacuum cleaner. A float air flow valve is mounted at the top of the central cylinder. When liquid accumulates to a given level within the central cylinder, the four bypass tubes, and the four canisters, suction is terminated by operation of the float valve.

Tightly-Coupled Image-Aided Inertial Navigation Using the Unscented Kalman Filter

DTIC Science & Technology

2007-01-01

Integrated GPS/MEMS Inertial Navigation Package. In Proceedings of ION GNSS 2004, pp. 825–832, September 2004. [2] R. G. Brown and P. Y. Hwang ...Tightly-Coupled Image-Aided Inertial Navigation Using the Unscented Kalman Filter S. Ebcin, Air Force Institute of Technology M. Veth, Air Force...inertial sen- sors using an extended Kalman filter (EKF) algo- rithm. In this approach, the image feature corre- spondence search was aided using the

Three field tests of a gas filter correlation radiometer

NASA Technical Reports Server (NTRS)

Campbell, S. A.; Casas, J. C.; Condon, E. P.

1977-01-01

Test flights to remotely measure nonurban carbon monoxide (CO) concentrations by gas filter correlation radiometry are discussed. The inferred CO concentrations obtained through use of the Gas Filter Correlation Radiometer (GFCR) agreed with independent measurements obtained by gas chromatography air sample bottle analysis to within 20 percent. The equipment flown on board the aircraft, the flight test procedure, the gas chromatograph direct air sampling procedure, and the GFCR data analysis procedure are reported.

42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

Code of Federal Regulations, 2011 CFR

2011-10-01

...; filter identification. 84.179 Section 84.179 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH...-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of the application for certification, shall specify the filter series and the filter efficiency level (i.e., “N95...

42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

Code of Federal Regulations, 2013 CFR

2013-10-01

...; filter identification. 84.179 Section 84.179 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH...-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of the application for certification, shall specify the filter series and the filter efficiency level (i.e., “N95...

42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

Code of Federal Regulations, 2010 CFR

2010-10-01

...; filter identification. 84.179 Section 84.179 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH...-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of the application for certification, shall specify the filter series and the filter efficiency level (i.e., “N95...

42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

Code of Federal Regulations, 2012 CFR

2012-10-01

...; filter identification. 84.179 Section 84.179 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH...-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of the application for certification, shall specify the filter series and the filter efficiency level (i.e., “N95...

42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

Code of Federal Regulations, 2014 CFR

2014-10-01

...; filter identification. 84.179 Section 84.179 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH...-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of the application for certification, shall specify the filter series and the filter efficiency level (i.e., “N95...

Leaf photosynthetic and water-relations responses for 'Valencia' orange trees exposed to oxidant air pollution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszyk, D.M.; Takemoto, B.K.; Poe, M.

1991-01-01

Leaf responses were measured to test a hypothesis that reduced photosynthetic capacity and/or altered water relations were associated with reductions in yield for 'Valencia' orange trees (Citrus sinensis (L.), Osbeck) exposed to ambient oxidant air pollution. Exposures were continuous for 4 years to three levels of oxidants (in charcoal-filtered, half-filtered, and non-filtered air). Oxidants had no effect on net leaf photosynthetic rates or on photosynthetic pigment concentrations. A single set of measurements indicated that oxidants increased leaf starch concentrations (24%) prior to flowering, suggesting a change in photosynthate allocation. Leaves exposed to oxidants had small, but consistent, changes in watermore » relations over the summer growing season, compared to trees growing in filtered air. Other changes included decreased stomatal conductance (12%) and transpiration (9%) rates, and increased water pressure potentials (5%). While all responses were subtle, their cumulative impact over 4 years indicated that 'Valencia' orange trees were subject to increased ambient oxidant stress.« less

Self absorption of alpha and beta particles in a fiberglass filter.

PubMed

Luetzelschwab, J W; Storey, C; Zraly, K; Dussinger, D

2000-10-01

Environmental air sampling uses fiberglass filters to collect particulate matter from the air and then a gas flow detector to measure the alpha and beta activity on the filter. When counted, the filter is located close to the detector so the alpha and beta particles emerging from the filter travel toward the detector at angles ranging from zero to nearly 90 degrees to the normal to the filter surface. The particles at small angles can readily pass through the filter, but particles at large angles pass through a significant amount of filter material and can be totally absorbed. As a result, counting losses can be great. For 4 MeV alpha particles, the filter used in this experiment absorbs 43% of the alpha particles; for 7.5 MeV alphas, the absorption is 13%. The measured beta activities also can have significant counting losses. Beta particles with maximum energies of 0.2 and 2.0 MeV have absorptions of 44 and 2%, respectively.

Measuring the radon concentration in air meting van de radonconcentratie in lucht

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aten, J.B.T.; Bierhuizen, H.W.J.; Vanhoek, L.P.

1975-01-01

A simple transportable apparatus for measurement of the radon concentration in the air of a workshop was developed. An air sample is sucked through a filter and the decay curve of the alpha activity is measured. The counting speed 40 min after sampling gives an indication of the radon activity. The apparatus was calibrated by analyzing an analogous decay curve obtained with a big filter and a big air sample, the activity being measured with an anti-coincidence counter. (GRA)

Comparison of 8 to 12 Micrometer and 3 to 5 Micrometer CVF Transmissometer Data with LOWTRAN Calculations.

DTIC Science & Technology

1984-06-26

case may be, in excess of 80 percent. They are multilayer coatings made by Optical Coating Laboratories, Inc., specifically for this application. The...series of measurements were made using each pinhole without the broadband filter. Then, the filters were inserted into the collimator source optics...between the primary mirror and the aperture wheel pinholes. Mea- surements were made at three (’VI positions corresponding to wavelengths cen- t(ered at

Effect of protective filters on fire fighter respiratory health: field validation during prescribed burns.

PubMed

De Vos, Annemarie J B M; Cook, Angus; Devine, Brian; Thompson, Philip J; Weinstein, Philip

2009-01-01

Bushfire smoke contains a range of air toxics. To prevent inhalation of these toxics, fire fighters use respiratory equipment. Yet, little is known about the effectiveness of the equipment on the fire ground. Experimental trials in a smoke chamber demonstrated that, the particulate/organic vapor/formaldehyde (POVF) filter performed best under simulated conditions. This article reports on the field validation trials during prescribed burns in Western Australia. Sixty-seven career fire fighters from the Fire and Emergency Services Authority of Western Australia were allocated one of the three types of filters. Spirometry, oximetry, self-reported symptom, and personal air sampling data were collected before, during and after exposure to bushfire smoke from prescribed burns. Declines in FEV(1) and SaO(2) were demonstrated after 60 and 120 min exposure. A significant higher number of participants in the P filter group reported increases in respiratory symptoms after the exposure. Air sampling inside the respirators demonstrated formaldehyde levels significantly higher in the P filter group compared to the POV and the POVF filter group. The field validation trials during prescribed burns supported the findings from the controlled exposure trials in the smoke chamber. Testing the effectiveness of three types of different filters under bushfire smoke conditions in the field for up to 2 hr demonstrated that the P filter is ineffective in filtering out respiratory irritants. The performance of the POV and the POVF filter appears to be equally effective after 2 hr bushfire smoke exposure in the field.

Is ultraviolet radiation on haemodialysis RO water beneficial?

PubMed

Stragier, A

2005-01-01

The quality of dialysis fluids has become increasingly important in the treatment of HD patients. Purified water represents over 95% of its volume. Bacterial and endotoxin content of Reverse Osmosis (RO) water is usually kept under control by bacterial filters, inserted in the distribution departure loop, and by monthly disinfection of the distribution circuit; the simpler the circuit, the better. This paper reports 12 years experience during which Ultraviolet Irradiation (UV) has replaced bacterial filters. To keep the bacterial growth under control in a complex RO water circuit (including a tank and multiple loops) a simple UV lamp was inserted in the departure line. It proved sufficient to keep bacterial count within AAMI norms. Failure of the UV lamp was associated with a rise of up to 500 cfu/ml in the last (fourth week) before routine disinfection. Normal levels were again obtained after replacement of the UV lamp. Six years later, a second UV lamp was added on the return loop. Bacterial counts and endotoxin levels in RO water promptly fell to <1 cfu/ml and <0.125 EU, till today. It is concluded that UV lamps should be favoured over bacterial filters in systems that are not disinfected daily, such as the RO water circuit. The principle of UV irradiation is explained and its advantage over bacterial filters is discussed. Future possible applications of UV are presented.

Novel Hollow Fiber Air Filters for the Removal of Ultrafine Particles in PM2.5 with Repetitive Usage Capability.

PubMed

Li, Manqing; Feng, Yingnan; Wang, Kaiyu; Yong, Wai Fen; Yu, Liya; Chung, Tai-Shung

2017-09-05

Severe air pollution has become a global concern, and there is a pressing need to develop effective and efficient air filters for removing airborne particulate matters (PMs). In this work, a highly permeable poly(ether sulfone) (PES) based hollow fiber membrane was developed via a one-step dry-jet wet spinning. For the first time, a hollow fiber membrane was used in removing the ultrafine particles (PMs with aerodynamic equivalent diameters of less than 100 nm) in PM 2.5 . The novel air filter was designed to possess the synergistic advantages of porous filters and fibrous filters with a sievelike outer surface and a fibrouslike porous substrate. A filtration efficiency of higher than 99.995% could be easily achieved when the self-support hollow fiber was challenged with less than 300 nm particulates. Without losses of the structural advantages, we have demonstrated that the permeation properties of the hollow fiber membrane can be facilely tailored via manipulation of the dope and bore fluid formulations. Various cleaning strategies were explored to regenerate the membrane performance after fouling. Both water rinse and backwash showed effectiveness to restore the membrane permeance for repetitive usage.

40 CFR 61.34 - Air sampling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... filters, or for replacement of equipment needing major repair. (c) Filters shall be analyzed and concentrations calculated within 30 days after filters are collected. Records of concentrations at all sampling...

40 CFR 61.34 - Air sampling.

Code of Federal Regulations, 2014 CFR

2014-07-01

... filters, or for replacement of equipment needing major repair. (c) Filters shall be analyzed and concentrations calculated within 30 days after filters are collected. Records of concentrations at all sampling...

Nonequal iteration directional filters permit selective clearance of ripples in passband circuits

NASA Technical Reports Server (NTRS)

Kurpis, G. P.

1970-01-01

Modified directional filter is comprised of alternate pairs of dielectric and air gap filter sections with unequal electrical lengths. Filter provides more flexibility in choosing dielectric material thickness and permits switching from specially ground to standard thicknesses.

A Chemical-Biological-Radio-Nuclear (CBRN) Filter can be Added to the Air-Outflow Port of a Ventilator to Protect a Home Ventilated Patient From Inhalation of Toxic Industrial Compounds.

PubMed

Be'eri, Eliezer; Owen, Simon; Beeri, Maurit; Millis, Scott R; Eisenkraft, Arik

2018-02-21

Chemical-biological-radio-nuclear (CBRN) gas masks are the standard means for protecting the general population from inhalation of toxic industrial compounds (TICs), for example after industrial accidents or terrorist attacks. However, such gas masks would not protect patients on home mechanical ventilation, as ventilator airflow would bypass the CBRN filter. We therefore evaluated in vivo the safety of adding a standard-issue CBRN filter to the air-outflow port of a home ventilator, as a method for providing TIC protection to such patients. Eight adult patients were included in the study. All had been on stable, chronic ventilation via a tracheostomy for at least 3 months before the study. Each patient was ventilated for a period of 1 hour with a standard-issue CBRN filter canister attached to the air-outflow port of their ventilator. Physiological and airflow measurements were made before, during, and after using the filter, and the patients reported their subjective sensation of ventilation continuously during the trial. For all patients, and throughout the entire study, no deterioration in any of the measured physiological parameters and no changes in measured airflow parameters were detected. All patients felt no subjective difference in the sensation of ventilation with the CBRN filter canister in situ, as compared with ventilation without it. This was true even for those patients who were breathing spontaneously and thus activating the ventilator's trigger/sensitivity function. No technical malfunctions of the ventilators occurred after addition of the CBRN filter canister to the air-outflow ports of the ventilators. A CBRN filter canister can be added to the air-outflow port of chronically ventilated patients, without causing an objective or subjective deterioration in the quality of the patients' mechanical ventilation. (Disaster Med Public Health Preparedness. 2018;page 1 of 5).

Solar Cell Modules With Improved Backskin

DOEpatents

Chevrefils, Andre; Grigore, Daniel Gheorghe

2001-01-23

The present invention relates to gas turbines and more particularly to a device for controlling the flow of cooling air through a flowpath in a turbine blade. The device can be inserted in the inlet opening of the blade flowpath and be retained therein. The device comprises a plug member for adjusting the flow of cooling air through the flowpath. The plug member comprises a retaining portion for retaining the plug member at the inlet opening of the flowpath and a blocking portion inserted within the flowpath for reducing the cross-sectional area of the inlet opening. Such a device is inexpensive and can be easily inserted in the inlet opening of a blade flowpath and retained therein.

Application of air ions for bacterial de-colonization in air filters contaminated by aerosolized bacteria.

PubMed

Kim, Yang Seon; Yoon, Ki Young; Park, Jae Hong; Hwang, Jungho

2011-01-15

We aerosolized the Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis) bacteria and collected them on membrane filters. Then we generated air ions by applying a high voltage to a carbon fiber tip and applied them to the contaminated filters. The antibacterial efficiency was not significantly affected by the bacteria being Gram-positive or Gram-negative, however, negative ions showed a lower antibacterial efficiency than positive ions to both E. coli and S. epidermidis, even though the concentration of negative air ions was much higher than that of positive air ions. With a field emission scanning electron microscope (FE-SEM) images and fluorescence microscopy images using a LIVE/DEAD BacLight Bacterial Viability Kit, electrostatic disruption of the bacteria was found to be the dominant antibacterial effect. Copyright © 2010 Elsevier B.V. All rights reserved.

A simple novel device for air sampling by electrokinetic capture

DOE PAGES

Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra; ...

2015-12-27

A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrodemore » assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87%, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. In conclusion, the performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.« less

A simple novel device for air sampling by electrokinetic capture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra

A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrodemore » assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87%, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. In conclusion, the performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.« less

A simple novel device for air sampling by electrokinetic capture.

PubMed

Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra; Frazier, Angel; Hampton-Marcell, Jarrad; Gilbert, Jack A

2015-12-27

A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrode assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87 %, with the reference filter taken as "gold standard." Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. The performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.

Miniaturized dielectric waveguide filters

NASA Astrophysics Data System (ADS)

Sandhu, Muhammad Y.; Hunter, Ian C.

2016-10-01

Design techniques for a new class of integrated monolithic high-permittivity ceramic waveguide filters are presented. These filters enable a size reduction of 50% compared to air-filled transverse electromagnetic filters with the same unloaded Q-factor. Designs for Chebyshev and asymmetric generalised Chebyshev filter and a diplexer are presented with experimental results for an 1800 MHz Chebyshev filter and a 1700 MHz generalised Chebyshev filter showing excellent agreement with theory.

Collection of biological and non-biological particles by new and used filters made from glass and electrostatically charged synthetic fibers.

PubMed

Raynor, P C; Kim, B G; Ramachandran, G; Strommen, M R; Horns, J H; Streifel, A J

2008-02-01

Synthetic filters made from fibers carrying electrostatic charges and fiberglass filters that do not carry electrostatic charges are both utilized commonly in heating, ventilating, and air-conditioning (HVAC) systems. The pressure drop and efficiency of a bank of fiberglass filters and a bank of electrostatically charged synthetic filters were measured repeatedly for 13 weeks in operating HVAC systems at a hospital. Additionally, the efficiency with which new and used fiberglass and synthetic filters collected culturable biological particles was measured in a test apparatus. Pressure drop measurements adjusted to equivalent flows indicated that the synthetic filters operated with a pressure drop less than half that of the fiberglass filters throughout the test. When measured using total ambient particles, synthetic filter efficiency decreased during the test period for all particle diameters. For particles 0.7-1.0 mum in diameter, efficiency decreased from 92% to 44%. It is hypothesized that this reduction in collection efficiency may be due to charge shielding. Efficiency did not change significantly for the fiberglass filters during the test period. However, when measured using culturable biological particles in the ambient air, efficiency was essentially the same for new filters and filters used for 13 weeks in the hospital for both the synthetic and fiberglass filters. It is hypothesized that the lack of efficiency reduction for culturable particles may be due to their having higher charge than non-biological particles, allowing them to overcome the effects of charge shielding. The type of particles requiring capture may be an important consideration when comparing the relative performance of electrostatically charged synthetic and fiberglass filters. Electrostatically charged synthetic filters with high initial efficiency can frequently replace traditional fiberglass filters with lower efficiency in HVAC systems because properly designed synthetic filters offer less resistance to air flow. Although the efficiency of charged synthetic filters at collecting non-biological particles declined substantially with use, the efficiency of these filters at collecting biological particles remained steady. These findings suggest that the merits of electrostatically charged synthetic HVAC filters relative to fiberglass filters may be more pronounced if collection of biological particles is of primary concern.

BIOLOGICAL WASTE AIR TREATMENT IN BIOTRICKLING FILTERS. (R825392)

EPA Science Inventory

Abstract

Recent studies in the area of biological waste air treatment in biotrickling filters have addressed fundamental key issues, such as biofilm architecture, microbiology of the process culture and means to control accumulation of biomass. The results from these s...

36. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" AIR FILTERS LOOKING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

36. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" AIR FILTERS LOOKING SOUTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - AIR PURATOR CORPORATION HUYGLAS 1405M FILTER SAMPLE

EPA Science Inventory

Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

Cleaner Air for Home and Office

NASA Technical Reports Server (NTRS)

1989-01-01

Increased insulation has led to higher concentrations in homes and offices of toxic chemicals caused by emissions from synthetic building components. Recent NASA research regarding future interplanetary manned spacecraft has shown that certain plants can absorb gasses, reducing indoor air pollution. After working with water purifying water hyacinths, Dr. B. C. Wolverton at NSTL developed a carbon/plant filter system to remove chemicals, smoke, etc. Two companies have commercialized the system. Bio-safe provides plants, a bed of activated carbon and an air pump installed near the plant's roots. Pollutants are trapped by the charcoal and either digested by the roots or broken down by microorganisms. Purified air is then directed back into the room. Applied Indoor Resource Company markets Bio-Pure, which includes plants on a layer of patented soil medium with activated carbon. Legumes and mosses filter the air; a blower moves air through the filtering system for cleansing by microorganisms. Research at NSTL continues, and the system may eventually be enlarged.

System for controlling child safety seat environment

NASA Technical Reports Server (NTRS)

Elrod, Susan V. (Inventor); Dabney, Richard W. (Inventor)

2008-01-01

A system is provided to control the environment experienced by a child in a child safety seat. Each of a plurality of thermoelectric elements is individually controllable to be one of heated and cooled relative to an ambient temperature. A first portion of the thermoelectric elements are positioned on the child safety seat such that a child sitting therein is positioned thereover. A ventilator coupled to the child safety seat moves air past a second portion of the thermoelectric elements and filters the air moved therepast. One or more jets coupled to the ventilator receive the filtered air. Each jet is coupled to the child safety seat and can be positioned to direct the heated/cooled filtered air to the vicinity of the head of the child sitting in the child safety seat.

UWB Filtering Power Divider with Two Narrow Notch-bands and Wide Stop-band

NASA Astrophysics Data System (ADS)

Wei, Feng; Wang, Xin-Yi; Zou, Xin Tong; Shi, Xiao Wei

2017-12-01

A compact filtering ultra-wideband (UWB) microstrip power divider (PD) with two sharply rejected notch-bands and wide stopband is analyzed and designed in this paper. The proposed UWB PD is based on a conventional Wilkinson power divider, while two stub loaded resonators (SLRs) are coupled into two symmetrical output ports to achieve a bandpass filtering response. The simplified composite right/left-handed (SCRLH) resonators are employed to generate the dual notched bands. Defected ground structure (DGS) is introduced to improve the passband performance. Good insertion/return losses, isolation and notch-band rejection are achieved as demonstrated in both simulation and experiment.

Cascaded Mach-Zehnder wavelength filters in silicon photonics for low loss and flat pass-band WDM (de-)multiplexing.

PubMed

Horst, Folkert; Green, William M J; Assefa, Solomon; Shank, Steven M; Vlasov, Yurii A; Offrein, Bert Jan

2013-05-20

We present 1-to-8 wavelength (de-)multiplexer devices based on a binary tree of cascaded Mach-Zehnder-like lattice filters, and manufactured using a 90 nm CMOS-integrated silicon photonics technology. We demonstrate that these devices combine a flat pass-band over more than 50% of the channel spacing with low insertion loss of less than 1.6 dB, and have a small device size of approximately 500 × 400 µm. This makes this type of filters well suited for application as WDM (de-)multiplexer in silicon photonics transceivers for optical data communication in large scale computer systems.

Toward polarized antiprotons: Machine development for spin-filtering experiments

NASA Astrophysics Data System (ADS)

Weidemann, C.; Rathmann, F.; Stein, H. J.; Lorentz, B.; Bagdasarian, Z.; Barion, L.; Barsov, S.; Bechstedt, U.; Bertelli, S.; Chiladze, D.; Ciullo, G.; Contalbrigo, M.; Dymov, S.; Engels, R.; Gaisser, M.; Gebel, R.; Goslawski, P.; Grigoriev, K.; Guidoboni, G.; Kacharava, A.; Kamerdzhiev, V.; Khoukaz, A.; Kulikov, A.; Lehrach, A.; Lenisa, P.; Lomidze, N.; Macharashvili, G.; Maier, R.; Martin, S.; Mchedlishvili, D.; Meyer, H. O.; Merzliakov, S.; Mielke, M.; Mikirtychiants, M.; Mikirtychiants, S.; Nass, A.; Nikolaev, N. N.; Oellers, D.; Papenbrock, M.; Pesce, A.; Prasuhn, D.; Retzlaff, M.; Schleichert, R.; Schröer, D.; Seyfarth, H.; Soltner, H.; Statera, M.; Steffens, E.; Stockhorst, H.; Ströher, H.; Tabidze, M.; Tagliente, G.; Engblom, P. Thörngren; Trusov, S.; Valdau, Yu.; Vasiliev, A.; Wüstner, P.

2015-02-01

The paper describes the commissioning of the experimental equipment and the machine studies required for the first spin-filtering experiment with protons at a beam kinetic energy of 49.3 MeV in COSY. The implementation of a low-β insertion made it possible to achieve beam lifetimes of τb=8000 s in the presence of a dense polarized hydrogen storage-cell target of areal density dt=(5.5 ±0.2 )×1 013 atoms /cm2 . The developed techniques can be directly applied to antiproton machines and allow the determination of the spin-dependent p ¯p cross sections via spin filtering.

Assessing and reducing fine and ultrafine particles inside Los Angeles taxis

NASA Astrophysics Data System (ADS)

Yu, Nu; Shu, Shi; Lin, Yan; Zhu, Yifang

2018-05-01

Taxi drivers and passengers are exposed to high levels of traffic-related air pollutants, but their exposures to fine (PM2.5) and ultrafine particles (UFPs) and related mitigation strategies are rarely explored. In this study, UFP and PM2.5 concentrations were monitored concurrently inside and outside of 22 taxis under different ventilation and mitigation conditions. Under realistic working conditions (no mitigation; NM), the average UFP and PM2.5 levels inside taxis were 1.46 × 104 particles/cm3 and 26 μg/m3, respectively. When the taxi ventilation was set to outside air mode and the windows kept closed, in-cabin UFP and PM2.5 concentrations are significantly associated with on-road concentrations, driving speed, and cabin air filter usage. The average in-cabin to on-roadway (I/O) ratios for UFP and PM2.5 were reduced from 0.60 to 0.75 under NM, to 0.47 and 0.52 under the most stringent mitigation strategy of keeping the windows closed and operating a high efficiency cabin air filter (WC + HECA). Among all tested taxi models, Toyota Prius exhibited the lowest UFP and PM2.5 I/O ratios under WC + HECA. Switching cabin air filters from the originally equipped manufacturer filter (OEM) to a HECA filter reduced the UFP and PM2.5 I/O ratios most effectively in Toyota Prius taxis as well.

Inflation with air via a facepiece for facilitating insertion of a nasogastric tube: a prospective, randomised, double-blind study.

PubMed

Gupta, D; Agarwal, A; Nath, S S; Goswami, D; Saraswat, V; Singh, P K

2007-02-01

Insertion of a nasogastric tube is a routine procedure but during anaesthesia it is often difficult and time consuming. One hundred and sixty adults undergoing elective surgery under general anaesthesia were randomly divided into two groups. After induction of anaesthesia, neuromuscular blockade and tracheal intubation, a nasogastric tube was inserted through the nose with the head of the patient in the neutral position, either with or without prior inflation with air via a facepiece attached to a self-inflating bag applied firmly with the face. Insertion of the nasogastric tube was successful in 75/78 (96%) following inflation compared with 54/80 (68%) without inflation (p<0.001). In four patients receiving inflation, a fibreoptic endoscope was passed as far as the upper oesophageal sphincter; this revealed opening of the upper oesophageal sphincter during inflation.

Hepa filter dissolution process

DOEpatents

Brewer, Ken N.; Murphy, James A.

1994-01-01

A process for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal.

A randomized double-blind crossover study of indoor air filtration and acute changes in cardiorespiratory health in a First Nations community.

PubMed

Weichenthal, S; Mallach, G; Kulka, R; Black, A; Wheeler, A; You, H; St-Jean, M; Kwiatkowski, R; Sharp, D

2013-06-01

Few studies have examined indoor air quality in First Nations communities and its impact on cardiorespiratory health. To address this need, we conducted a crossover study on a First Nations reserve in Manitoba, Canada, including 37 residents in 20 homes. Each home received an electrostatic air filter and a placebo filter for 1 week in random order, and lung function, blood pressure, and endothelial function measures were collected at the beginning and end of each week. Indoor air pollutants were monitored throughout the study period. Indoor PM2.5 decreased substantially during air filter weeks relative to placebo (mean difference: 37 μg/m(3) , 95% CI: 10, 64) but remained approximately five times greater than outdoor concentrations owing to a high prevalence of indoor smoking. On average, air filter use was associated with a 217-ml (95% CI: 23, 410) increase in forced expiratory volume in 1 s, a 7.9-mm Hg (95% CI: -17, 0.82) decrease in systolic blood pressure, and a 4.5-mm Hg (95% CI: -11, 2.4) decrease in diastolic blood pressure. Consistent inverse associations were also observed between indoor PM2.5 and lung function. In general, our findings suggest that reducing indoor PM2.5 may contribute to improved lung function in First Nations communities. Indoor air quality is known to contribute to adverse cardiorespiratory health, but few studies have examined indoor air quality in First Nations communities. Our findings suggest that indoor PM2.5 may contribute to reduced lung function and that portable air filters may help to alleviate these effects by effectively reducing indoor levels of particulate matter. © Her Majesty the Queen in Right of Canada 2012. Reproduced with the permission of the Minister of Health Canada.

Development and comparison of projection and image space 3D nodule insertion techniques

NASA Astrophysics Data System (ADS)

Robins, Marthony; Solomon, Justin; Sahbaee, Pooyan; Samei, Ehsan

2016-04-01

This study aimed to develop and compare two methods of inserting computerized virtual lesions into CT datasets. 24 physical (synthetic) nodules of three sizes and four morphologies were inserted into an anthropomorphic chest phantom (LUNGMAN, KYOTO KAGAKU). The phantom was scanned (Somatom Definition Flash, Siemens Healthcare) with and without nodules present, and images were reconstructed with filtered back projection and iterative reconstruction (SAFIRE) at 0.6 mm slice thickness using a standard thoracic CT protocol at multiple dose settings. Virtual 3D CAD models based on the physical nodules were virtually inserted (accounting for the system MTF) into the nodule-free CT data using two techniques. These techniques include projection-based and image-based insertion. Nodule volumes were estimated using a commercial segmentation tool (iNtuition, TeraRecon, Inc.). Differences were tested using paired t-tests and R2 goodness of fit between the virtually and physically inserted nodules. Both insertion techniques resulted in nodule volumes very similar to the real nodules (<3% difference) and in most cases the differences were not statistically significant. Also, R2 values were all <0.97 for both insertion techniques. These data imply that these techniques can confidently be used as a means of inserting virtual nodules in CT datasets. These techniques can be instrumental in building hybrid CT datasets composed of patient images with virtually inserted nodules.

CHEMICAL REMOVAL OF BIOMASS FROM WASTE AIR BIOTRICKLING FILTERS: SCREENING CHEMICALS OF POTENTIAL INTEREST. (R825392)

EPA Science Inventory

A protocol was developed to rapidly assess the efficiency of chemical washing for the removal of excess biomass from biotrickling filters for waste air treatment. Although the experiment was performed on a small scale, conditions were chosen to simulate application in full-scale ...

Reiter works with SWAB ASD Filter Kit in the U.S. Laboratory during Expedition 13

NASA Image and Video Library

2006-09-10

ISS013-E-80066 (10 Sept. 2006) --- European Space Agency (ESA) astronaut Thomas Reiter, Expedition 13 flight engineer, works with the surface, water and air biocharacterization (SWAB) air sampling device (ASD) filter kit in the Destiny laboratory of the International Space Station.

Astronaut Frederick Gregory vacuums air filters in avionics bay

NASA Image and Video Library

1985-05-03

51B-13-008 (29 April-6 May 1985) --- Astronaut Frederick D. Gregory vacuums air filters in avionics bay. The 51-B pilot is physically located in the overhead area of the middeck on Challenger, but his activity is only a few meters away from the flight deck.

Should We Remove the Retrievable Cook Celect Inferior Vena Cava Filter? Eight Years of Experience at a Single Center.

PubMed

Son, Joohyung; Bae, Miju; Chung, Sung Woon; Lee, Chung Won; Huh, Up; Song, Seunghwan

2017-12-01

The inferior vena cava filter (IVCF) is very effective for preventing pulmonary embolism in patients who cannot undergo anticoagulation therapy. However, if a filter is placed in the body permanently, it may lead to other complications. A retrospective study was performed of 159 patients who underwent retrievable Cook Celect IVCF implantation between January 2007 and April 2015 at a single center. Baseline characteristics, indications, and complications caused by the filter were investigated. The most common underlying disease of patients receiving the filter was cancer (24.3%). Venous thrombolysis or thrombectomy was the most common indication for IVCF insertion in this study (47.2%). The most common complication was inferior vena cava penetration, the risk of which increased the longer the filter remained in the body (p=0.032, Exp(B)=1.004). If the patient is able to retry anticoagulation therapy and the filter is no longer needed, the filter should be removed, even if a long time has elapsed since implantation. If the filter cannot be removed, it is recommended that follow-up computed tomography be performed regularly to monitor the progress of venous thromboembolisms as well as any filter-related complications.

Electronic resonant tunneling on graphene superlattice heterostructures with a tunable graphene layer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Shan; Cui, Liyong; Liu, Fen

We have theoretically investigated the electronic resonant tunneling effect in graphene superlattice heterostructures, where a tunable graphene layer is inserted between two different superlattices. It is found that a complete tunneling state appears inside the enlarged forbidden gap of the heterostructure by changing the thickness of the inserted graphene layer and the transmittance of the tunneling state depends on the thickness of the inserted layer. Furthermore, the frequency of the tunneling state changes with the thickness of the inserted graphene layer but it always located in the little overlapped forbidden gap of two graphene superlattices. Therefore, both a perfect tunnelingmore » state and an ultrawide forbidden gap are realized in such heterostrutures. Since maximum probability densities of the perfect tunneling state are highly localized near the interface between the inserted graphene layer and one graphene superlattice, it can be named as an interface-like state. Such structures are important to fabricate high-Q narrowband electron wave filters.« less

Development of Test Protocols for International Space Station Particulate Filters

NASA Technical Reports Server (NTRS)

Green, Robert D.; Vijayakumar, R.; Agui, Juan H.

2014-01-01

Air quality control on the International Space Station (ISS) is a vital requirement for maintaining a clean environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of gravitational settling. The ISS Environmental Control and Life Support System (ECLSS) uses a filtration system that has been in use for over 14 years and has proven to meet this challenge. The heart of this system is a traditional High- Efficiency Particulate Air (HEPA) filter configured to interface with the rest of the life support elements and provide effective cabin filtration. Over the years, the service life of these filters has been re-evaluated based on limited post-flight tests of returned filters and risk factors. On earth, a well designed and installed HEPA filter will last for several years, e.g. in industrial and research clean room applications. Test methods for evaluating these filters are being developed on the basis of established test protocols used by the industry and the military. This paper will discuss the test methods adopted and test results on prototypes of the ISS filters. The results will assist in establishing whether the service life can be extended for these filters. Results from unused filters that have been in storage will also be presented to ascertain the shelf life and performance deterioration, if any and determine if the shelf life may be extended.

Results from Evaluation of Proposed ASME AG-1 Section FI Metal Media Filters - 13063

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, John A.; Giffin, Paxton K.; Parsons, Michael S.

High efficiency particulate air (HEPA) filtration technology is commonly used in Department of Energy (DOE) facilities that require control of radioactive particulate matter (PM) emissions due to treatment or management of radioactive materials. Although HEPA technology typically makes use of glass fiber media, metal and ceramic media filters are also capable of filtering efficiencies beyond the required 99.97%. Sintered metal fiber filters are good candidates for use in DOE facilities due to their resistance to corrosive environments and resilience at high temperature and elevated levels of relative humidity. Their strength can protect them from high differential pressure or pressure spikesmore » and allow for back pulse cleaning, extending filter lifetime. Use of these filters has the potential to reduce the cost of filtration in DOE facilities due to life cycle cost savings. ASME AG-1 section FI has not been approved due to a lack of protocols and performance criteria for qualifying section FI filters. The Institute for Clean Energy Technology (ICET) with the aid of the FI project team has developed a Section FI test stand and test plan capable of assisting in the qualification ASME AG-1 section FI filters. Testing done at ICET using the FI test stand evaluates resistance to rated air flow, test aerosol penetration and resistance to heated air of the section FI filters. Data collected during this testing consists of temperature, relative humidity, differential pressure, flow rate, upstream particle concentration, and downstream particle concentration. (authors)« less

Broadband notch filter design for millimeter-wave plasma diagnostics.

PubMed

Furtula, V; Michelsen, P K; Leipold, F; Salewski, M; Korsholm, S B; Meo, F; Nielsen, S K; Stejner, M; Moseev, D; Johansen, T

2010-10-01

Notch filters are integrated in plasma diagnostic systems to protect millimeter-wave receivers from intensive stray radiation. Here we present a design of a notch filter with a center frequency of 140 GHz, a rejection bandwidth of ∼900 MHz, and a typical insertion loss below 2 dB in the passband of ±9 GHz. The design is based on a fundamental rectangular waveguide with eight cylindrical cavities coupled by T-junction apertures formed as thin slits. Parameters that affect the notch performance such as physical lengths and conductor materials are discussed. The excited resonance mode in the cylindrical cavities is the fundamental TE(11). The performance of the constructed filter is measured using a vector network analyzer monitoring a total bandwidth of 30 GHz. We compare the measurements with numerical simulations.

Design and performance of a high-Tc superconductor coplanar waveguide filter

NASA Technical Reports Server (NTRS)

Chew, Wilbert; Riley, A. L.; Rascoe, Daniel L.; Hunt, Brian D.; Foote, Marc C.; Cooley, Thomas W.; Bajuk, Louis J.

1991-01-01

The design of a coplanar waveguide low-pass filter made of YBa2Cu3O(7-delta) (YBCO) on an LaAlO3 substrate is described. Measurements were incorporated into simple models for microwave CAD analysis to develop a final design. The patterned and packaged coplanar waveguide low-pass filter of YBCO, with dimensions suited for integrated circuits, exhibited measured insertion losses when cooled in liquid nitrogen superior to those of a similarly cooled thin-film copper filter throughout the 0 to 9.5 GHz passband. Coplanar waveguide models for use with thin-film normal metal (with thickness either greater or less than the skin depth) and YBCO are discussed and used to compare the losses of the measured YBCO and copper circuits.

A comparison of two nano-sized particle air filtration tests in the diameter range of 10 to 400 nanometers

NASA Astrophysics Data System (ADS)

Japuntich, Daniel A.; Franklin, Luke M.; Pui, David Y.; Kuehn, Thomas H.; Kim, Seong Chan; Viner, Andrew S.

2007-01-01

Two different air filter test methodologies are discussed and compared for challenges in the nano-sized particle range of 10-400 nm. Included in the discussion are test procedure development, factors affecting variability and comparisons between results from the tests. One test system which gives a discrete penetration for a given particle size is the TSI 8160 Automated Filter tester (updated and commercially available now as the TSI 3160) manufactured by the TSI, Inc., Shoreview, MN. Another filter test system was developed utilizing a Scanning Mobility Particle Sizer (SMPS) to sample the particle size distributions downstream and upstream of an air filter to obtain a continuous percent filter penetration versus particle size curve. Filtration test results are shown for fiberglass filter paper of intermediate filtration efficiency. Test variables affecting the results of the TSI 8160 for NaCl and dioctyl phthalate (DOP) particles are discussed, including condensation particle counter stability and the sizing of the selected particle challenges. Filter testing using a TSI 3936 SMPS sampling upstream and downstream of a filter is also shown with a discussion of test variables and the need for proper SMPS volume purging and filter penetration correction procedure. For both tests, the penetration versus particle size curves for the filter media studied follow the theoretical Brownian capture model of decreasing penetration with decreasing particle diameter down to 10 nm with no deviation. From these findings, the authors can say with reasonable confidence that there is no evidence of particle thermal rebound in the size range.

Operation JANGLE. Particle Studies. Projects 2.5a-1, 2.5a-2, 2.5a-3, 2. 8,

DTIC Science & Technology

1979-10-01

air with time. 26.1 Brookhaven Air Monitor A filter paper feed system traveling at 4 inches per hour combined with a vacuum pump (3.5 ou ft/min) was...Monitor This Instrument also employs an air pumping system (2.6 cu.ft/min) with filter paper 6 Inohes wide traveling at 7 inches per hour or multiples...JANGLE of the Portable Air Sampler (PAS) used previously by Test Division, CRL and Dug.way Proving Ground, Utah. Its purpose was to pro- vde an

In situ fabrication of depth-type hierarchical CNT/quartz fiber filters for high efficiency filtration of sub-micron aerosols and high water repellency

NASA Astrophysics Data System (ADS)

Li, Peng; Zong, Yichen; Zhang, Yingying; Yang, Mengmeng; Zhang, Rufan; Li, Shuiqing; Wei, Fei

2013-03-01

We fabricated depth-type hierarchical CNT/quartz fiber (QF) filters through in situ growth of CNTs upon quartz fiber (QF) filters using a floating catalyst chemical vapor deposition (CVD) method. The filter specific area of the CNT/QF filters is more than 12 times higher than that of the pristine QF filters. As a result, the penetration of sub-micron aerosols for CNT/QF filters is reduced by two orders of magnitude, which reaches the standard of high-efficiency particulate air (HEPA) filters. Simultaneously, due to the fluffy brush-like hierarchical structure of CNTs on QFs, the pore size of the hybrid filters only has a small increment. The pressure drop across the CNT/QF filters only increases about 50% with respect to that of the pristine QF filters, leading to an obvious increased quality factor of the CNT/QF filters. Scanning electron microscope images reveal that CNTs are very efficient in capturing sub-micron aerosols. Moreover, the CNT/QF filters show high water repellency, implying their superiority for applications in humid conditions.We fabricated depth-type hierarchical CNT/quartz fiber (QF) filters through in situ growth of CNTs upon quartz fiber (QF) filters using a floating catalyst chemical vapor deposition (CVD) method. The filter specific area of the CNT/QF filters is more than 12 times higher than that of the pristine QF filters. As a result, the penetration of sub-micron aerosols for CNT/QF filters is reduced by two orders of magnitude, which reaches the standard of high-efficiency particulate air (HEPA) filters. Simultaneously, due to the fluffy brush-like hierarchical structure of CNTs on QFs, the pore size of the hybrid filters only has a small increment. The pressure drop across the CNT/QF filters only increases about 50% with respect to that of the pristine QF filters, leading to an obvious increased quality factor of the CNT/QF filters. Scanning electron microscope images reveal that CNTs are very efficient in capturing sub-micron aerosols. Moreover, the CNT/QF filters show high water repellency, implying their superiority for applications in humid conditions. Electronic supplementary information (ESI) available: Schematic of the synthesis process of the CNT/QF filter; typical size distribution of atomized polydisperse NaCl aerosols used for air filtration testing; images of a QF filter and a CNT/QF filter; SEM image of a CNT/QF filter after 5 minutes of sonication in ethanol; calculation of porosity and filter specific area. See DOI: 10.1039/c3nr34325a

Soil separator and sampler and method of sampling

DOEpatents

O'Brien, Barry H [Idaho Falls, ID; Ritter, Paul D [Idaho Falls, ID

2010-02-16

A soil sampler includes a fluidized bed for receiving a soil sample. The fluidized bed may be in communication with a vacuum for drawing air through the fluidized bed and suspending particulate matter of the soil sample in the air. In a method of sampling, the air may be drawn across a filter, separating the particulate matter. Optionally, a baffle or a cyclone may be included within the fluidized bed for disentrainment, or dedusting, so only the finest particulate matter, including asbestos, will be trapped on the filter. The filter may be removable, and may be tested to determine the content of asbestos and other hazardous particulate matter in the soil sample.

Disk filter

DOEpatents

Bergman, Werner

1986-01-01

An electric disk filter provides a high efficiency at high temperature. A hollow outer filter of fibrous stainless steel forms the ground electrode. A refractory filter material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer filter surfaces through the electrified refractory filter media and between the high voltage electrodes and is removed from a space in the high voltage electrode.

Disk filter

DOEpatents

Bergman, W.

1985-01-09

An electric disk filter provides a high efficiency at high temperature. A hollow outer filter of fibrous stainless steel forms the ground electrode. A refractory filter material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer filter surfaces through the electrified refractory filter media and between the high voltage electrodes and is removed from a space in the high voltage electrode.

40 CFR Appendix Xii to Part 266 - Nickel or Chromium-Bearing Materials that may be Processed in Exempt Nickel-Chromium Recovery...

Code of Federal Regulations, 2012 CFR

2012-07-01

... sweepings Air filters Electroplating bath filters Wastewater filter media Wood pallets Disposable clothing... cartridge filters Paper hand towels B. Exempt Nickel or Chromium-Bearing Materials when Generated by Any... Nickel, chromium, and iron catalysts Nickel-cadmium and nickel-iron batteries Filter cake from wet...

HEPA filter dissolution process

DOEpatents

Brewer, K.N.; Murphy, J.A.

1994-02-22

A process is described for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal. 4 figures.

40 CFR Appendix Xii to Part 266 - Nickel or Chromium-Bearing Materials that may be Processed in Exempt Nickel-Chromium Recovery...

Code of Federal Regulations, 2014 CFR

2014-07-01

... sweepings Air filters Electroplating bath filters Wastewater filter media Wood pallets Disposable clothing... cartridge filters Paper hand towels B. Exempt Nickel or Chromium-Bearing Materials when Generated by Any... Nickel, chromium, and iron catalysts Nickel-cadmium and nickel-iron batteries Filter cake from wet...

40 CFR Appendix Xii to Part 266 - Nickel or Chromium-Bearing Materials that may be Processed in Exempt Nickel-Chromium Recovery...

Code of Federal Regulations, 2010 CFR

2010-07-01

... sweepings Air filters Electroplating bath filters Wastewater filter media Wood pallets Disposable clothing... cartridge filters Paper hand towels B. Exempt Nickel or Chromium-Bearing Materials when Generated by Any... Nickel, chromium, and iron catalysts Nickel-cadmium and nickel-iron batteries Filter cake from wet...

40 CFR Appendix Xii to Part 266 - Nickel or Chromium-Bearing Materials that may be Processed in Exempt Nickel-Chromium Recovery...

Code of Federal Regulations, 2013 CFR

2013-07-01

... sweepings Air filters Electroplating bath filters Wastewater filter media Wood pallets Disposable clothing... cartridge filters Paper hand towels B. Exempt Nickel or Chromium-Bearing Materials when Generated by Any... Nickel, chromium, and iron catalysts Nickel-cadmium and nickel-iron batteries Filter cake from wet...

40 CFR Appendix Xii to Part 266 - Nickel or Chromium-Bearing Materials that may be Processed in Exempt Nickel-Chromium Recovery...

Code of Federal Regulations, 2011 CFR

2011-07-01

... sweepings Air filters Electroplating bath filters Wastewater filter media Wood pallets Disposable clothing... cartridge filters Paper hand towels B. Exempt Nickel or Chromium-Bearing Materials when Generated by Any... Nickel, chromium, and iron catalysts Nickel-cadmium and nickel-iron batteries Filter cake from wet...

Air-mass flux measurement system using Doppler-shifted filtered Rayleigh scattering

NASA Technical Reports Server (NTRS)

Shirley, John A.; Winter, Michael

1993-01-01

An optical system has been investigated to measure mass flux distributions in the inlet of a high speed air-breathing propulsion system. Rayleigh scattered light from air is proportional to the number density of molecules and hence can be used to ascertain the gas density in a calibrated system. Velocity field measurements are achieved by spectrally filtering the elastically-scattered Doppler-shifted light with an absorbing molecular filter. A novel anamorphic optical collection system is used which allows optical rays from different scattering angles, that have different Doppler shifts, to be recorded separately. This is shown to obviate the need to tune the laser through the absorption to determine velocities, while retaining the ability to make spatially-resolved measurements along a line. By properly selecting the laser tuning and filter parameters, simultaneous density measurements can be made. These properties are discussed in the paper and experiments demonstrating the velocimetry capability are described.

Evaluating the suitability of highly cross-linked and remelted materials for use in posterior stabilized knees.

PubMed

Huot, J Caitlin; Van Citters, Douglas W; Currier, John H; Currier, Barbara H; Mayor, Michael B; Collier, John P

2010-11-01

Posterior stabilized (PS) knee designs are a popular choice for cruciate sacrificing knee arthroplasty procedures. The introduction of PS inserts fabricated from highly cross-linked and remelted Ultra High Molecular Weight Polyethylene (UHMWPE) has recently generated concern as these materials have been shown to possess reduced mechanical properties. This study investigated whether highly cross-linked and remelted UHMWPE material (referred to as XRP) can be expected to perform similarly to historical gamma-air polyethylene, which has suffered few reported incidences of tibial post failure. Never-implanted gamma-air PS tibial inserts shelf-aged 14 years were examined and compared to XRP materials. Evaluation of oxidation levels, impact toughness, and fatigue strength demonstrated never-implanted gamma-air PS tibial inserts to possess nonuniform mechanical properties. Despite severe oxidation along the exterior of gamma-air tibial posts, comparatively low oxidation levels at the center of the tibial posts corresponded to sufficiently high mechanical properties. XRP material (75 kGy) showed superior impact toughness over shelf aged gamma-air material; however, tibial post fatigue testing demonstrated XRP material (100 kGy) to be less resistant to fatigue failure than historical gamma-air material. Results from this study indicate that XRP materials (100 kGy) may demonstrate an inferior resistance to tibial post failure than historical polyethylene. © 2010 Wiley Periodicals, Inc.

Quick-change filter cartridge

DOEpatents

Rodgers, John C.; McFarland, Andrew R.; Ortiz, Carlos A.

1995-01-01

A quick-change filter cartridge. In sampling systems for measurement of airborne materials, a filter element is introduced into the sampled airstream such that the aerosol constituents are removed and deposited on the filter. Fragile sampling media often require support in order to prevent rupture during sampling, and careful mounting and sealing to prevent misalignment, tearing, or creasing which would allow the sampled air to bypass the filter. Additionally, handling of filter elements may introduce cross-contamination or exposure of operators to toxic materials. Moreover, it is desirable to enable the preloading of filter media into quick-change cartridges in clean laboratory environments, thereby simplifying and expediting the filter-changing process in the field. The quick-change filter cartridge of the present invention permits the application of a variety of filter media in many types of instruments and may also be used in automated systems. The cartridge includes a base through which a vacuum can be applied to draw air through the filter medium which is located on a porous filter support and held there by means of a cap which forms an airtight seal with the base. The base is also adapted for receiving absorbing media so that both particulates and gas-phase samples may be trapped for investigation, the latter downstream of the aerosol filter.

40 CFR 60.431 - Definitions and notations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Definitions and notations. 60.431 Section 60.431 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., package inserts, book jackets, market circulars, magazine inserts, and shopping news, Newspapers, magazine...

40 CFR 60.431 - Definitions and notations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Definitions and notations. 60.431 Section 60.431 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., package inserts, book jackets, market circulars, magazine inserts, and shopping news, Newspapers, magazine...

40 CFR 60.431 - Definitions and notations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Definitions and notations. 60.431 Section 60.431 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., package inserts, book jackets, market circulars, magazine inserts, and shopping news, Newspapers, magazine...

40 CFR 60.431 - Definitions and notations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Definitions and notations. 60.431 Section 60.431 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., package inserts, book jackets, market circulars, magazine inserts, and shopping news, Newspapers, magazine...

40 CFR 60.431 - Definitions and notations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Definitions and notations. 60.431 Section 60.431 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., package inserts, book jackets, market circulars, magazine inserts, and shopping news, Newspapers, magazine...

The effectiveness of stand alone air cleaners for shelter-in-place.

PubMed

Ward, M; Siegel, J A; Corsi, R L

2005-04-01

Stand-alone air cleaners may be efficient for rapid removal of indoor fine particles and have potential use for shelter-in-place (SIP) strategies following acts of bioterrorism. A screening model was employed to ascertain the potential significance of size-resolved particle (0.1-2 microm) removal using portable high efficiency particle arresting (HEPA) air cleaners in residential buildings following an outdoor release of particles. The number of stand-alone air cleaners, air exchange rate, volumetric flow rate through the heating, ventilating and air-conditioning (HVAC) system, and size-resolved particle removal efficiency in the HVAC filter were varied. The effectiveness of air cleaners for SIP was evaluated in terms of the outdoor and the indoor particle concentration with air cleaner(s) relative to the indoor concentration without air cleaners. Through transient and steady-state analysis of the model it was determined that one to three portable HEPA air cleaners can be effective for SIP following outdoor bioaerosol releases, with maximum reductions in particle concentrations as high as 90% relative to conditions in which an air cleaner is not employed. The relative effectiveness of HEPA air cleaners vs. other removal mechanisms was predicted to decrease with increasing particle size, because of increasing competition by particle deposition with indoor surfaces and removal to HVAC filters. However, the effect of particle size was relatively small for most scenarios considered here. The results of a screening analysis suggest that stand-alone (portable) air cleaners that contain high efficiency particle arresting (HEPA) filters can be effective for reducing indoor fine particle concentrations in residential dwellings during outdoor releases of biological warfare agents. The relative effectiveness of stand-alone air cleaners for reducing occupants' exposure to particles of outdoor origin depends on several factors, including the type of heating, ventilating and air-conditioning (HVAC) filter, HVAC operation, building air exchange rate, particle size, and duration of elevated outdoor particle concentration. Maximum particle reductions, relative to no stand-alone air cleaners, of 90% are predicted when three stand-alone air cleaners are employed.

42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

AMERICAN AIR FILTER KINPACTOR 10 X 56 VENTURI SCRUBBER EVALUATION

EPA Science Inventory

The report gives results of an evaluation of an American Air Filter Kinpactor 10 x 56 venturi scrubber, operating on emissions from a large borax fusing furnace. Average total efficiency was 97.5% during the test period. The venturi was operated at a pressure drop of 110 cm W. C....

40 CFR 60.5225 - What are the monitoring and calibration requirements for compliance with my operating limits?

Code of Federal Regulations, 2014 CFR

2014-07-01

... limited to the following: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY... maintain your bag leak detection system in continuous operation according to your monitoring plan required...

40 CFR 60.5225 - What are the monitoring and calibration requirements for compliance with my operating limits?

Code of Federal Regulations, 2013 CFR

2013-07-01

... limited to the following: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY... maintain your bag leak detection system in continuous operation according to your monitoring plan required...

Compressed air as a source of inhaled oxidants in intensive care units.

PubMed

Thibeault, D W; Rezaiekhaligh, M H; Ekekezie, I; Truog, W E

1999-01-01

Exhaled gas from mechanically ventilated preterm infants was found to have similar oxidant concentrations, regardless of lung disease, leading to the hypothesis that wall outlet gases were an oxidant source. Oxidants in compressed room air and oxygen from wall outlets were assessed in three hospitals. Samples were collected by flowing wall outlet gas through a heated humidifier and an ice-packed condenser. Nitric oxide (NO) was measured in intensive care room air and in compressed air with and without a charcoal filter using a Sievers NOA280 nitric oxide analyzer (Boulder, CO). Oxidants were measured by spectrophotometry and expressed as nMol equivalents of H2O2/mL. The quantity of oxidant was also expressed as amount of Vitamin C (nMol/mL) added until the oxidant was nondetectable. This quantity of Vitamin C was also expressed in Trolox Equivalent Antioxidant Capacity (TEAC) units (mMol/L). Free and total chlorine were measured with a Chlorine Photometer. Oxidants were not found in compressed oxygen and were only found in compressed air when the compression method used tap water. At a compressed room air gas flow of 1.5 L/min, the total volume of condensate was 20.2 +/- 1 mL/hr. The oxidant concentration was 1.52 +/- 0.09 nMol/mL equivalents of H2O2/mL of sample and 30.8 +/- 1.2 nMol/hr; 17.9% of that found in tap water. Oxidant reduction required 2.05 +/-0.12 nMol/mL vitamin C, (1.78 +/- 0.1 x 10(-3) TEAC units). Free and total chlorine in tap water were 0.3 +/- 0.02 mg/mL and 2.9 +/- 0.002 mg/mL, respectively. Outlet gas contained 0.4 +/- 0.06 mg/mL and 0.07 + 0.01 mg/mL total and free chlorine, respectively; both 14% of tap water. When a charcoal filter was installed in the hospital with oxidants in compressed air, oxidants were completely removed. Nursery room air contained 12.4 +/- 0.5 ppb NO; compressed wall air without a charcoal filter, 8.1 +/- 0.1 ppb and compressed air with a charcoal filter 12.5 +/- 0.5 ppb. A charcoal filter does not remove NO. (Table 3) We recommend that all compressed air methods using tap water have charcoal filters at the compression site and the gases be assessed periodically for oxidants.

Does interspecific competition alter effects of early season ozone exposure on plants from wet grasslands? Results of a three-year experiment in open-top chambers.

PubMed

Tonneijck, A E G; Franzaring, J; Brouwer, G; Metselaar, K; Dueck, Th A

2004-09-01

Chronic effects of ozone on wet grassland species early in the growing season might be altered by interspecific competition. Individual plants of Holcus lanatus, Lychnis flos-cuculi, Molinia caerulea and Plantago lanceolata were grown in monocultures and in mixed cultures with Agrostis capillaris. Mesocosms were exposed to charcoal-filtered air plus 25 nl l(-1) ozone (CF+25), non-filtered air (NF), non-filtered air plus 25 nl l(-1) ozone (NF+25) and non-filtered air plus 50 nl l(-1) ozone (NF+50) early in the growing seasons of 2000 through 2002. Ozone-enhanced senescence and visible foliar injury were recorded on some of the target plants in the first year only. Ozone effects on biomass production were minimal and plant response to ozone did not differ between monocultures and mixed cultures. After three years, above-ground biomass of the plants in mixed culture compared to monocultures was three times greater for H. lanatus and two to four times smaller for the other species.

Energy efficient skylight construction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jentoft, A.P.; Couture, P.A.

1978-02-14

An energy efficient skylight construction is described. A skylight cover is secured by a frame to a curbing comprised of an insulating core, the interior and exterior surfaces of which are covered by non-combustible shields separated along the upper and lower surfaces of the curbing by a gap which serves as a ''thermal break'' between the highly conductive inner and outer shields. The frame is pierced by drain openings the exterior of which are covered by a filter type material such as foam or glass fibers that is both absorbtive of moisture and resistant to the passage of air. Themore » frame is secured to the outward portion of the curbing and includes a flange extending inward across the gap between the shields, which serves as a gutter to collect condensation which drips off the glazing. The inward portion of the flange is covered with an insulating gasket which prevents condensation from forming on the flange and which prevents the warmer, more moisture laden, inside air from reaching the cold underside of the gutter flange or the edge of the outerskin. The core insulation is inserted, without adhesives, into the assembled inside skin, and then the exposed surface of the insulation is bonded to the inside surface of the outer skin.« less

Genetic diversity of Aspergillus fumigatus in indoor hospital environments.

PubMed

Araujo, Ricardo; Amorim, António; Gusmão, Leonor

2010-09-01

Environmental isolates of Aspergillus fumigatus are less studied than those recovered from clinical sources. In the present study, the genetic diversity among such environmental isolates was assessed, as well as their dispersion ability and the acquisition of new strains in 19 medical units of the same hospital. A. fumigatus isolates were genotyped using a single multiplex PCR-based reaction with eight microsatellite markers and an insertion/deletion polymorphism. A total of 130 unique genotypes were found among a total of 250 A. fumigatus isolates. Genotypic diversity ranged from 0.86 to 1 in samples from hospital rooms, and there was no correlation between these samples and the presence of high-efficiency particulate air filters or any other air filtration system. Four of the six most prevalent A. fumigatus strains were recovered from water samples. The occurrence of microvariation was common among environmental isolates, which affected each of the microsatellite markers. The assessment of the genetic diversity of A. fumigatus is a useful tool for illustrating the presence or absence of specific clonal populations in a clinical setting. A. fumigatus populations were highly dynamic indoors, and new populations were found in just a few months. Due to the high indoor dispersion capability of A. fumigatus, more attention should be given to strains with increased pathogenic potential or reduced susceptibility to anti-fungal drugs.

40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2012 CFR

2012-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2013 CFR

2013-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2014 CFR

2014-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2011 CFR

2011-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2010 CFR

2010-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

ETV TEST REPORT OF CONTROL OF BIOAEROSOLS IN HVAC SYSTEMS GLASFLOSS INDUSTRIES EXCEL FILTER, MODEL SBG24242898

EPA Science Inventory

The Environmental Technology Verification report discusses the technology and performance of the Excel Filter, Model SBG24242898 air filter for dust and bioaerosol filtration manufactured by Glasfloss Industries, Inc. The pressure drop across the filter was 82 Pa clean and 348 Pa...

Proceedings of the 21st DOE/NRC Nuclear Air Cleaning Conference; Sessions 1--8

DOE Office of Scientific and Technical Information (OSTI.GOV)

First, M.W.

1991-02-01

Separate abstracts have been prepared for the papers presented at the meeting on nuclear facility air cleaning technology in the following specific areas of interest: air cleaning technologies for the management and disposal of radioactive wastes; Canadian waste management program; radiological health effects models for nuclear power plant accident consequence analysis; filter testing; US standard codes on nuclear air and gas treatment; European community nuclear codes and standards; chemical processing off-gas cleaning; incineration and vitrification; adsorbents; nuclear codes and standards; mathematical modeling techniques; filter technology; safety; containment system venting; and nuclear air cleaning programs around the world. (MB)

Air purification equipment combining a filter coated by silver nanoparticles with a nano-TiO2 photocatalyst for use in hospitals

NASA Astrophysics Data System (ADS)

Son Le, Thanh; Hien Dao, Trong; Nguyen, Dinh Cuong; Chau Nguyen, Hoai; Balikhin, I. L.

2015-03-01

X-ray diffraction, scanning electron microscopy and transmission electron microscopy showed that TiO2 particles synthesized by a sol-gel procedure exhibited uniform size about 16-20 nm. This nanopowder was deposited on a porous quartz tube (D = 74 mm, L = 418 mm, deposit density ˜16.4 mg cm-2) through an intermediate adhesive polymethylmethacrylate layer to manufacture a photocatalytic filter tube. A polypropylene pre-filter was coated with a nanosilver layer (particle size ˜20 nm) prepared by aqueous molecular solution method. An air cleaner of 250 m3 h-1 capacity equipped with this pre-filter, an electrostatic air filter, 4 photocatalytic filter tubes and 4 UV-A lamps (36 W) presented the high degradation ability for certain volatile organic compounds (VOCs), bacteria and fungi. The VOCs degradation performances of the equipment with respect to divers compounds are different: in a 10 m3 box, 91.6% of butanol was removed within 55 min, 80% of acetone within 100 min, 70.1% of diethyl ether within 120 min and only 43% of benzene was oxidized within 150 min. Over 99% of bacteria and fungi were killed after the air passage through the equipment. For application, it was placed in the intensive care room (volume of 125 m3) of E hospital in Hanoi; 69% of bacteria and 63% of fungi were killed within 6 h.

Optical molecular fluorescence determination of ultra-trace beryllium in occupational and environmental samples using highly alkaline conditions.

PubMed

Adams, Lori; Agrawal, Anoop; Cronin, John P; Ashley, Kevin

2017-01-01

Exposures to beryllium (Be), even at extremely low levels, can cause severe health effects in a percentage of those exposed; consequently, occupational exposure limits (OELs) promulgated for this element are the lowest established for any element. This work describes the advantages of using highly alkaline dye solutions for determination of Be in occupational hygiene and environmental samples by means of an optical molecular fluorescence technique after sample extraction in 1-3% (w˖w -1 ) aqueous ammonium bifluoride (NH 4 HF 2 ). Improved attributes include the ability to further enhance the detection limits of Be in extraction solutions of high acidity with minimal dilution, which is particularly beneficial when NH 4 HF 2 solutions of higher concentration are used for extraction of Be from soil samples. Significant improvements in Be method detection limits (MDLs) are obtained at levels many-fold below those reported previously for this methodology. Notably, MDLs for Be of <0.01 ng l -1 / 0.1 ng per sample have been attained, which are superior to MDLs routinely reported for this element by means of the most widely used ultra-trace elemental measurement technique, inductively coupled plasma mass spectrometry (ICP-MS). Very low MDLs for Be are essential in consideration of reductions in OELs for this element in workplace air by health organizations and regulatory agencies in the USA and internationally. Applications of enhanced Be measurements to air filter samples, surface wipe samples, soils and newly-designed occupational air sampler inserts are illustrated.

Air Sampling Filter

NASA Technical Reports Server (NTRS)

1980-01-01

General Metal Works' Accu-Vol is a high-volume air sampling system used by many government agencies to monitor air quality for pollution control purposes. Procedure prevents possible test-invalidating contamination from materials other than particulate pollutants, caused by manual handling or penetration of windblown matter during transit, a cassette was developed in which the filter is sealed within a metal frame and protected in transit by a snap-on aluminum cover, thus handled only under clean conditions in the laboratory.

Approach to Cultural Asset Preservation "Enzyme Filter Media Has Bactericidal Effect and Bacteriostasis Effect in Air Phase"

NASA Astrophysics Data System (ADS)

Isomae, Kazuro

Enzyme air-filter media according to the bactericidal effect as an environmental green technology acquired the high appraisal and the result in the domestic and foreign clean room and the air conditioning field. The mechanism of this enzyme technology, safety, and the bactericidal effect in the real environment are discussed by using the electron microscopic picture etc. And it proposes to apply these technologies to the cultural asset preservation.

Fusion of electromagnetic trackers to improve needle deflection estimation: simulation study.

PubMed

Sadjadi, Hossein; Hashtrudi-Zaad, Keyvan; Fichtinger, Gabor

2013-10-01

We present a needle deflection estimation method to anticipate needle bending during insertion into deformable tissue. Using limited additional sensory information, our approach reduces the estimation error caused by uncertainties inherent in the conventional needle deflection estimation methods. We use Kalman filters to combine a kinematic needle deflection model with the position measurements of the base and the tip of the needle taken by electromagnetic (EM) trackers. One EM tracker is installed on the needle base and estimates the needle tip position indirectly using the kinematic needle deflection model. Another EM tracker is installed on the needle tip and estimates the needle tip position through direct, but noisy measurements. Kalman filters are then employed to fuse these two estimates in real time and provide a reliable estimate of the needle tip position, with reduced variance in the estimation error. We implemented this method to compensate for needle deflection during simulated needle insertions and performed sensitivity analysis for various conditions. At an insertion depth of 150 mm, we observed needle tip estimation error reductions in the range of 28% (from 1.8 to 1.3 mm) to 74% (from 4.8 to 1.2 mm), which demonstrates the effectiveness of our method, offering a clinically practical solution.

Enhanced performance of a filter-sensor system.

PubMed

Sasaki, Isao; Josowicz, Mira; Janata, Jirí; Glezer, Ari

2006-06-01

In this paper are addressed two important, but seemingly unrelated issues: long term performance of a gas sensing array and performance of an air purification unit. It is shown that when considered together, the system can be regarded as a "smart filter". The enhancement is achieved by periodic differential sampling and measurement of the "upstream" and "downstream" gases of a filter. The correctly functioning filter supplies the "zero gas" from the downstream for the continuous sensor baseline correction. A key element in this scheme is the synthetic jet that delivers well-defined pulses of the two gases. The deterioration of the performance of the "smart filter" can be diagnosed from the response pattern of the sensor. The approach has been demonstrated on removal/sensing of ammonia gas from air.

Simple Freeze-Drying Procedure for Producing Nanocellulose Aerogel-Containing, High-Performance Air Filters.

PubMed

Nemoto, Junji; Saito, Tsuguyuki; Isogai, Akira

2015-09-09

Simple freeze-drying of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibril (TOCN) dispersions in water/tert-butyl alcohol (TBA) mixtures was conducted to prepare TOCN aerogels as high-performance air filter components. The dispersibility of the TOCNs in the water/TBA mixtures, and the specific surface area (SSA) of the resulting TOCN aerogels, was investigated as a function of the TBA concentration in the mixtures. The TOCNs were homogeneously dispersed in the water/TBA mixtures at TBA concentrations up to 40% w/w. The SSAs of the TOCN aerogels exceeded 300 m2/g when the TBA concentration in the aqueous mixtures was in the range from 20% to 50% w/w. When a commercially available, high-efficiency particulate air (HEPA) filter was combined with TOCN/water/TBA dispersions prepared using 30% TBA, and the product was freeze-dried, the resulting TOCN aerogel-containing filters showed superior filtration properties. This was because nanoscale, spider-web-like networks of the TOCNs with large SSAs were formed within the filter.

Compact ultra wide band microstrip bandpass filter based on multiple-mode resonator and modified complementary split ring resonator.

PubMed

Marcotegui, J Antonio; Illescas, Jesús Miguel; Estevez, Aritz; Falcone, Francisco

2013-01-01

A new class of broadband microstrip filters for Ultra Wide Band (UWB) applications is proposed. In the design, different stages of parallel-coupled microstrip line and other stages with a Modified Complementary Split Ring Resonator (MCSRR)-a concept proposed here for the first time-are adjusted to obtain the desired response with broadband, sharp rejection, low insertion loss, and low return loss. Full wave simulation results as well as measurement results from fabricated prototypes are presented, showing good agreement. The proposed technique offers a new alternative to implement low-cost high-performance filter devices, applicable to a wide range of communication systems.

Compact Ultra Wide Band Microstrip Bandpass Filter Based on Multiple-Mode Resonator and Modified Complementary Split Ring Resonator

PubMed Central

Marcotegui, J. Antonio; Illescas, Jesús Miguel; Estevez, Aritz

2013-01-01

A new class of broadband microstrip filters for Ultra Wide Band (UWB) applications is proposed. In the design, different stages of parallel-coupled microstrip line and other stages with a Modified Complementary Split Ring Resonator (MCSRR)—a concept proposed here for the first time—are adjusted to obtain the desired response with broadband, sharp rejection, low insertion loss, and low return loss. Full wave simulation results as well as measurement results from fabricated prototypes are presented, showing good agreement. The proposed technique offers a new alternative to implement low-cost high-performance filter devices, applicable to a wide range of communication systems. PMID:24319366

Crosstalk elimination in the detection of dual-beam optical tweezers by spatial filtering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ott, Dino; Oddershede, Lene B., E-mail: oddershede@nbi.dk; Reihani, S. Nader S.

2014-05-15

In dual-beam optical tweezers, the accuracy of position and force measurements is often compromised by crosstalk between the two detected signals, this crosstalk leading to systematic and significant errors on the measured forces and distances. This is true both for dual-beam optical traps where the splitting of the two traps is done by polarization optics and for dual optical traps constructed by other methods, e.g., holographic tweezers. If the two traps are orthogonally polarized, most often crosstalk is minimized by inserting polarization optics in front of the detector; however, this method is not perfect because of the de-polarization of themore » trapping beam introduced by the required high numerical aperture optics. Here we present a simple and easy-to-implement method to efficiently eliminate crosstalk. The method is based on spatial filtering by simply inserting a pinhole at the correct position and is highly compatible with standard back focal plane photodiode based detection of position and force. Our spatial filtering method reduces crosstalk up to five times better than polarization filtering alone. The effectiveness is dependent on pinhole size and distance between the traps and is here quantified experimentally and reproduced by theoretical modeling. The method here proposed will improve the accuracy of force-distance measurements, e.g., of single molecules, performed by dual-beam optical traps and hence give much more scientific value for the experimental efforts.« less

Fungal spore concentrations in two haematopoietic stem cell transplantation (HSCT) units containing distinct air control systems.

PubMed

Brun, C P; Miron, D; Silla, L M R; Pasqualotto, A C

2013-04-01

Invasive fungal diseases have emerged as important causes of morbidity and mortality in haematological patients. In this study air samples were collected in two haematopoietic stem cell transplantation (HSCT) units, in which distinct air-control systems were in place. In hospital 1 no high-efficiency particulate air (HEPA) filter was available whereas in hospital 2 HSCT rooms were equipped with HEPA filters, with positive air pressure in relation to the corridor. A total of 117 samples from rooms, toilets and corridors were obtained during December 2009 to January 2011, using a six-stage Andersen sampler. In both hospitals, the concentration of potentially pathogenic fungi in the air was reduced in patients' rooms compared to corridors (P < 0·0001). Despite the presence of a HEPA filter in hospital 2, rooms in both hospitals showed similar concentrations of potentially pathogenic fungi (P = 0·714). These findings may be explained by the implementation of additional protective measures in hospital 1, emphasizing the importance of such measures in protected environments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ottney, T.C.

Filtration systems that are incorrectly selected, installed and maintained can cause excessive particulates in occupied spaces. This article describes how to identify and correct problems. Particulate matter can be removed from ventilation air at several sites within a building. These sites include: on heat exchanger surfaces; inside ductwork, ceiling tiles and diffusers; and in the air filter. The cost associated with removing these unwanted contaminants is unavoidable. However, this removal cost varies depending on where the particulates have been deposited. Not all particulates that are generated by work-related activities are transported to the filter bank by return air currents beforemore » being deposited on other surfaces. Accordingly, walls still have to be repainted at varying intervals and carpeting vacuumed. Ceiling tiles will discolor at a rate that is influenced by their texture, the air outlet velocity, the amount of dirt in the ventilation air and how much contaminant is being generated in the room. It is estimated that 15% of ventilation air escapes the air filtration process. This leakage results in higher utility, janitorial and redecorating costs as well as contributing to employee absenteeism. When building management does not prevent it, air-conditioning coils and ductwork become an unintended part of the building's air filtration system. In time, this is much more expensive both in energy and cleaning costs than the steps available to keep them clean. Good particulate control can lower the total cost of building operation. However, a building operator may not have to upgrade to a higher efficiency filter to achieve higher system efficiency. Simply eliminating the source of leaks and better management of the existing filters may be all that is necessary.« less

Mid- and long-term outcome of patients with permanent inferior vena cava filters: a single center review.

PubMed

Chow, Felix Che-Lok; Chan, Yiu-Che; Cheung, Grace Chung-Yan; Cheng, Stephen Wing-Keung

2015-07-01

Inferior vena cava (IVC) filters are used to prevent pulmonary embolism (PE), especially in patients with active contraindication to systemic anticoagulation. The aim of this study is to examine the outcomes of patients who received permanent IVC filters at our institution. This is a single-center retrospective observational study with review of a prospectively collected database for patients who had permanent IVC filters. Patient demographics, indications of filter placement, postprocedure clinical outcome and complications, as well as use of anticoagulant therapy were documented. Chi-squared test was used to test for statistically significant differences (IBM SPSS version 21; IBM Corp., Armonk, NY), while survival was calculated using Kaplan-Meier survival curves analysis. Between February 1998 and December 2013, a total of 109 patients with a median age of 65 (47 men, range 19-97) years had IVC filters inserted at our institution. All of them had documented venous thromboembolism (VTE) before filter placement: 99 (90.8%) had lower extremity deep vein thrombosis (DVT) (including 34 iliac, 65 infrainguinal), 9 (8.3%) had massive PE without evidence of lower limb DVT, and 1 (0.9%) had isolated IVC thrombosis. Forty-seven (43.1%) patients had PE before filter insertion. There were 2 serious procedure-related complications: one access site thrombosis and one right ventricular perforation. With a mean follow-up of 36 ± 33 months, no patient had further symptomatic PE or paradoxical embolism. There were a total of 54 (49.5%) deaths, with a 30-day mortality of 8.3%; none of them was device or procedure related. Among the 92 patients followed up, 27 (29.3%) had further VTE-either DVT in the index or the contralateral lower limb (20 patients, 21.7%), or thrombus inside the filter or the IVC (14 patients, 15.2%). Forty-one (44.6%) patients reported post-thrombotic syndrome (PTS) symptoms. Anticoagulant therapy was given to 39 (42.4%) and 55 (59.8%) patients in the periprocedural period and at any time during the study period, respectively. It did not reduce the rate of postfilter VTE or PTS in both instances. None of the filters in this series was retrieved. This observational study showed that IVC filters were effective in the prevention of PE, although symptomatic postfilter VTE and PTS were common, leading to significant morbidity. Patients who received permanent filters have high mortality on follow-up; however, none were procedure or device related. Copyright © 2015 Elsevier Inc. All rights reserved.

48 CFR 1352.271-72 - Additional Item Requirements (AIR)-growth work

Code of Federal Regulations, 2011 CFR

2011-10-01

... Requirements (AIR)-growth work 1352.271-72 Section 1352.271-72 Federal Acquisition Regulations System... Clauses 1352.271-72 Additional Item Requirements (AIR)—growth work As prescribed in 48 CFR 1371.103, insert the following clause: Additional Item Requirements (Air)—Growth Work (APR 2010) (a) This clause...

14 CFR 250.9 - Written explanation of denied boarding compensation and boarding priorities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... of air carrier), you are probably entitled to monetary compensation. This notice explains the airline... of (name of air carrier): (In this space the carrier inserts its boarding priority rules or a summary... compensation is based shall include any surcharge and air transportation tax. “Alternate transportation” is air...

The impact of recirculation, ventilation and filters on secondary organic aerosols generated by indoor chemistry

NASA Astrophysics Data System (ADS)

Fadeyi, M. O.; Weschler, C. J.; Tham, K. W.

This study examined the impact of recirculation rates (7 and 14 h -1), ventilation rates (1 and 2 h -1), and filtration on secondary organic aerosols (SOAs) generated by ozone of outdoor origin reacting with limonene of indoor origin. Experiments were conducted within a recirculating air handling system that serviced an unoccupied, 236 m 3 environmental chamber configured to simulate an office; either no filter, a new filter or a used filter was located downstream of where outdoor air mixed with return air. For otherwise comparable conditions, the SOA number and mass concentrations at a recirculation rate of 14 h -1 were significantly smaller than at a recirculation rate of 7 h -1. This was due primarily to lower ozone concentrations, resulting from increased surface removal, at the higher recirculation rate. Increased ventilation increased outdoor-to-indoor transport of ozone, but this was more than offset by the increased dilution of SOA derived from ozone-initiated chemistry. The presence of a particle filter (new or used) strikingly lowered SOA number and mass concentrations compared with conditions when no filter was present. Even though the particle filter in this study had only 35% single-pass removal efficiency for 100 nm particles, filtration efficiency was greatly amplified by recirculation. SOA particle levels were reduced to an even greater extent when an activated carbon filter was in the system, due to ozone removal by the carbon filter. These findings improve our understanding of the influence of commonly employed energy saving procedures on occupant exposures to ozone and ozone-derived SOA.

Instituting a filtration/pressurization system to reduce dust concentrations in a control room at a mineral processing plant

PubMed Central

Noll, J.; Cecala, A.; Hummer, J.

2016-01-01

The National Institute for Occupational Safety and Health has observed that many control rooms and operator compartments in the U.S. mining industry do not have filtration systems capable of maintaining low dust concentrations in these areas. In this study at a mineral processing plant, to reduce respirable dust concentrations in a control room that had no cleaning system for intake air, a filtration and pressurization system originally designed for enclosed cabs was modified and installed. This system was composed of two filtering units: one to filter outside air and one to filter and recirculate the air inside the control room. Eighty-seven percent of submicrometer particles were reduced by the system under static conditions. This means that greater than 87 percent of respirable dust particles should be reduced as the particle-size distribution of respirable dust particles is greater than that of submicrometer particles, and filtration systems usually are more efficient in capturing the larger particles. A positive pressure near 0.02 inches of water gauge was produced, which is an important component of an effective system and minimizes the entry of particles, such as dust, into the room. The intake airflow was around 118 cfm, greater than the airflow suggested by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) for acceptable indoor air quality. After one year, the loading of the filter caused the airflow to decrease to 80 cfm, which still produces acceptable indoor air quality. Due to the loading of the filters, the reduction efficiency for submicrometer particles under static conditions increased to 94 percent from 87 percent. PMID:26834293

Apparatus tube configuration and mounting for solid oxide fuel cells

DOEpatents

Zymboly, G.E.

1993-09-14

A generator apparatus is made containing long, hollow, tubular, fuel cells containing an inner air electrode, an outer fuel electrode, and solid electrolyte there between, placed between a fuel distribution board and a board which separates the combustion chamber from the generating chamber, where each fuel cell has an insertable open end and in insertable, plugged, closed end, the plugged end being inserted into the fuel distribution board and the open end being inserted through the separator board where the plug is completely within the fuel distribution board. 3 figures.

Copper emissions from a high volume air sampler

NASA Technical Reports Server (NTRS)

King, R. B.; Toma, J.

1975-01-01

High volume air samplers (hi vols) are described which utilize a brush-type electric motor to power the fans used for pulling air through the filter. Anomalously high copper values were attributed to removal of copper from the commutator into the air stream due to arcing of the brushes and recirculation through the filter. Duplicate hi vols were set up under three operating conditions: (1) unmodified; (2) gasketed to prevent internal recirculation; and (3) gasketed and provided with a pipe to transport the motor exhaust some 20 feet away. The results of 5 days' operation demonstrate that hi vols can suddenly start emitting increased amounts of copper with no discernible operational indication, and that recirculation and capture on the filter can take place. Copper levels found with hi vols whose exhaust was discharged at a distance downwind were among the lowest found, and apparently provides a satisfactory solution to copper contamination.

Aethalometer™ Instrument Handbook

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sedlacek, Arthur J.

2016-04-01

The Aethalometer is an instrument that provides a real-time readout of the concentration of “Black” or “Elemental” carbon aerosol particles (BC or E) in an air stream (see Figure 1 and Figure 2). It is a self-contained instrument that measures the rate of change of optical transmission through a spot on a filter where aerosol is being continuously collected and uses the information to calculate the concentration of optically absorbing material in the sampled air stream. The instrument measures the transmitted light intensities through the “sensing” portion of the filter, on which the aerosol spot is being collected, and amore » “reference” portion of the filter as a check on the stability of the optical source. A mass flowmeter monitors the sample air flow rate. The data from these three measurements is used to determine the mean BC content of the air stream.« less