Assessment on the Collection Efficiency of an Aerosol Sampler in Micro and Nanoparticles Environment

2014 ◽  
Vol 609-610 ◽  
pp. 483-488 ◽  
Author(s):  
Yi Yang ◽  
Ping Mao ◽  
Shu Yan Feng ◽  
Jin Hua Zhang
Keyword(s):  
Collection Efficiency ◽  
Cascade Impactor ◽  
Test Results ◽  
Simple Method ◽  
Workplace Environment ◽  
Aerosol Nanoparticles ◽  
Micrometer Particle ◽  
In Series ◽  
Order Of Magnitude ◽  
Assessment Result

The collection efficiency (CE) of an aerosol sampler is usually assessed dependently by using a sampler with higher CE and higher sampling accuracy or comparing the grain size distribution, concentration and/or other characteristics of the collected dust to that of the original dust, instead of the sampler itself. To establish a simple method for the assessment on the collection efficiency (CE) of an aerosol sampler, a self-dependent method was derived to calculate the CE of an aerosol sampler, which was patented with the number of ZL200910233001.X by the State Intellectual Property Office of China. According to the patent method, two or more uniform aerosol samplers of the same model were connected in series the inlet of a sampler was connected directly with the outlet of another sampler. The CE (η) of the aerosol sampler can be calculated by a simple equation as:η=1-m2/m1, in whichm1andm2is the weight of the aerosol particles collected by sampler 1# and sampler 2# in the connection sequence, respectively. A cascade impactor sampler was used to sample in a micrometer particle (d50=2.5 μm) aerosol environment and a nanoparticle (d50=42 nm) aerosol environment which were formed artificially in a glove box, as well as a workplace environment which manufactured nanometer powders. The sampling test results indicated that the cascade impactor sampler showed relative high CE (99.51%) for micrometer aerosol but a little bit low CE (95.2%) for nanoparticle aerosol. However, a low CE (93.93%) was calculated out by the method because of low concentration aerosol nanoparticles in the workplace environment, which result to big testing errors. It was found that the assessment result on collection efficiency of a sampler is highly affected by the subsequent analytical methods and detection accuracies after the sampling process. If the precision of the electronic balance was improved to a reasonable higher order of magnitude, the cascade impactor sampler can hopefully show much higher collection efficiency on nanoparticle aerosols.

Treatment of Dairy Wastewater in a Novel Moving Bed Biofilm Reactor

1992 ◽  
Vol 26 (3-4) ◽  
pp. 703-711 ◽  
Author(s):  
B. Rusten ◽  
H. Ødegaard ◽  
A. Lundar
Keyword(s):  
Surface Area ◽  
Pilot Plant ◽  
Industrial Effluents ◽  
Biofilm Reactor ◽  
Dairy Wastewater ◽  
Test Results ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
Biofilm Reactors ◽  
In Series

A novel moving bed biofilm reactor has been developed, where the biofilm grows on small, free floating plastic elements with a large surface area and a density slightly less than 1.0 g/cm3. The specific biofilm surface area can be regulated as required, up to a maximum of approximately 400 m2/m3. The ability to remove organic matter from concentrated industrial effluents was tested in an aerobic pilot-plant with two moving bed biofilm reactors in series and a specific biofilm surface area of 276 m2/m3. Treating dairy wastewater, the pilot-plant showed 85% and 60% COD removal at volumetric organic loading rates of 500 g COD/m3h and 900 g COD/m3h respectively. Based on the test results, the moving bed biofilm reactors should be very suitable for treatment of food industry effluents.

Effect of Environmental Materials on Aqueous Corrosion of R7T7 Glass

1988 ◽  
Vol 127 ◽  
Author(s):  
N. Godon ◽  
E. Vernaz ◽  
J. H. Thomassin ◽  
J. C. Touray
Keyword(s):  
Atmospheric Pressure ◽  
Test Results ◽  
Aqueous Corrosion ◽  
Environmental Material ◽  
Environmental Materials ◽  
Activated Bentonite ◽  
Order Of Magnitude ◽  
Glass Specimen ◽  
Icp Analysis ◽  
Glass Behavior

ABSTRACTR7T7 glass behavior was investigated in contact with eleven different materials including smectites, bentonites, illites, granite and sand. The experiments were conducted at 90°C under atmospheric pressure with a 4 cm−1 SA/V ratio using two grams of material in double distilled water under static leaching conditions without renewal of the leachate. For each material a control test was conducted under the same conditions but without the glass specimen, as well as a series of tests on glass alone, without the environmental material. Kinetics studies lasting up to 364 days were performed on four selected materials.The test results (mass loss, ICP analysis of the leachates, SEM and TEM observations) showed relatively slight glass alteration in contact with sand, granite and one bentonite (i.e. the same order of magnitude as glass alone in deionized water), but greater alteration of glass in contact with all the other clays.The significant differences in glass behavior in contact with environmental materials can be accounted for by the behavior of the latter in solution: activated bentonite releases very large amounts of silicon and sodium into solution while smectite seems to remove silicon from solution.

Evaluation of the Service Performance of Ships

2005 ◽  
Vol 42 (04) ◽  
pp. 177-183
Author(s):  
Poul Andersen ◽  
Anne-Sophie Borrod ◽  
Hervé Blanchot
Keyword(s):  
Input Data ◽  
High Efficiency ◽  
Service Performance ◽  
The Other ◽  
Simple Method ◽  
Propulsive Efficiency ◽  
Order Of Magnitude ◽  
Time Periods

A simple method has been established for the evaluation of the service performance of ships. Input data are easily collected daily on board and transformed to a well-defined condition that makes possible the comparison between ships, for instance, sister ships, and between different time periods of voyages for the same ship. The procedure has been applied to two ships that are identical, with the only exception that one has a conventional propeller, whereas the other one is fitted with a high-efficiency propeller of the KAPPEL type. The results are obtained from a period of 2 years steaming for both vessels. They clearly confirm the increase of propulsive efficiency obtained with the KAPPEL propeller in the order of magnitude of 4%.

A Simple Method for Elastic Analysis of Grillages

1968 ◽  
Vol 12 (02) ◽  
pp. 153-159
Author(s):  
Pin-Yu Chang
Keyword(s):  
Finite Element ◽  
Plate Theory ◽  
Computer Time ◽  
Design Tool ◽  
Matrix Transformations ◽  
Simple Method ◽  
Elastic Foundations ◽  
Beam Analysis ◽  
Order Of Magnitude ◽  
Desk Calculator

The theory of beams supported by elastic foundations has been shown to be particularly well-suited to the analysis of grillage beams [1, 2, 3[.2 This theory leads to a far more general formulation regarding the types of structures amenable to analysis than that offered by the orthotropic plate theory. As compared to the methods of finite element theory, the theory of beams supported by elastic foundations decreases the computer time by an order of magnitude, thus making the analysis particularly valuable as a design tool. This paper shows that the measurement of the grillage beam analysis based upon the elastic foundation concept can be further simplified by certain matrix transformations that uncouple the deflection equations. The problem has, in fact, been simplified to such an extent that many large grillages can be analyzed with the aid of a desk calculator. Whenever comparison with results obtained from finite element methods has been possible, it has been found that, for all practical purposes, complete correlation exists.

Simple method for preparing a concentration gradient of serum components by freezing and thawing

1991 ◽  
Vol 37 (7) ◽  
pp. 1225-1229 ◽  
Author(s):  
Tetsuo Hirano ◽  
Toshiaki Yoneyama ◽  
Hiroko Matsuzaki ◽  
Takainitsu Sekine
Keyword(s):  
Concentration Gradient ◽  
Clinical Laboratory ◽  
Freezing Temperature ◽  
Test Results ◽  
Freezing And Thawing ◽  
Serum Samples ◽  
Simple Method ◽  
Gradient Formation ◽  
Repeated Freezing ◽  
Serum Components

Abstract We created a simple method for obtaining a series of successively more-concentrated samples from a serum without changing the ratio of its components. We froze a pooled serum and then allowed it to thaw undisturbed. The serum components formed a gradient of increasing concentration from the top of the sample to the bottom. We found that (a) in test results, each fraction of serum in the gradient showed almost the same relative concentrations of components (i.e., inorganic and organic compounds, proteins, metals, and hormones), irrespective of atomic or molecular mass; (b) the concentration gradient depended on the thawing temperature but not on the freezing temperature; (c) when we thawed the frozen sample with centrifugation, the slope of the concentration gradient increased with increasing centrifugal force; (d) when the thawed sample was fractionated into 10 fractions from the top to the bottom, the original serum concentration was always maintained between the sixth and seventh fractions from the top; and (e) the concentration gradient became steeper with repeated freezing and thawing. By using this method, one can easily prepare serum samples at gradients of concentration useful in the clinical laboratory, although the mechanism of gradient formation is still unclear.

The performance of batch stabilization reservoirs for wastewater treatment, storage and reuse in Israel

1996 ◽  
Vol 33 (10-11) ◽  
pp. 149-159 ◽  
Author(s):  
Marcelo Juanico
Keyword(s):  
Wastewater Treatment ◽  
Controlled Release ◽  
Treated Wastewater ◽  
Batch Reactors ◽  
Batch Mode ◽  
Removal Of Heavy Metals ◽  
In Series ◽  
Order Of Magnitude ◽  
Real Scale

Stabilization reservoirs receive partially treated wastewater effluents for storage and controlled release. They are used in Israel for two purposes: a) to upgrade the quality of the effluents during the long residence time within the reservoirs and, b) to store the effluents during the rainy winter in order to perform agricultural irrigation during the dry summer. The improvement obtained in the quality of the effluents (i.e., the treatment capacity of the reservoirs) depends on the operational regime of the reservoirs as reactors: continuous flow, in series, batch, etc. The performance of the reservoirs as batch reactors for wastewater treatment is herein analyzed based on outdoor experiments carried out in real scale reservoirs with different hydraulic and organic loadings. The results of the experiments are compared with forecasts obtained through statistical and kinetic models. Stabilization reservoirs working in batch mode, when properly designed and operated, are able to remove COD, BOD, TSS and detergents by up to one order of magnitude, and Faecal coliforms by up to five orders of magnitude (before chlorination). A significant removal of heavy metals, bacteriophages and other pollutants is also obtained. The quality of the effluents released from the reservoirs, added to the capability for controlled release, permits both wide crop rotation and easy management of irrigation.

Investigation of Chatter Vibration in End-Milling Process by Considering Coupled System Model

2014 ◽  
Vol 939 ◽  
pp. 201-208
Author(s):  
Kosuke Hattori ◽  
Hiroyuki Kodama ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
Cutting Tool ◽  
End Milling ◽  
Milling Process ◽  
Work Piece ◽  
Vibration Modes ◽  
Test Results ◽  
Chatter Vibration ◽  
Simple Method ◽  
Excited Vibration ◽  
End Milling Process

Chatter vibration in cutting processes usually leads to surface finish degradation, tool damage, cutting noise, energy loss, etc. Self-excited vibration particularly seems to be a problem that is easily increased to large vibration. The regenerative effect is considered as one of the causes of chatter vibration. Although the chatter vibration occurs in various types of processing, the end-milling is a typical process that seems to cause the chatter vibration due to a lack of rigidity of one or more parts of the machine tools, cutting tool, and work-piece. The aim of our research is to propose a simple method to control chatter vibration of the end-milling process on the basis of a coupling model integrating the related various elements. In this study, hammering tests were carried out to measure the transfer function of a machine tool and cutting tool system, which seems to cause vibration. By comparing these results, finite elemental method (FEM) analysis models were constructed. Additionally, cutting experiments were carried out to confirm the chatter vibration frequencies in end-milling with a machining center. In the hammering tests, impulse hammer and multiple acceleration pick-ups are connected to a multi-channel FFT analyzer and estimate the natural frequencies and natural vibration modes. A simplified FEM model is proposed by circular section stepped beam elements on the basis of the hammering test results, considering a coupling effect. In comparisons of the calculated results and hammering test results, the vibration modes are in good agreement. As a result, the proposed model accurately predicts the chatter vibration considering several effects among the relating elements in end-milling. Moreover, it can be seen that the chatter vibration is investigated from a viewpoint of the integrating model of the end-milling process.

Deep Levels in 4H Silicon Carbide Epilayers Induced by Neutron-Irradiation up to 1016 n/cm2

2006 ◽  
Vol 911 ◽  
Author(s):  
Anna Cavallini ◽  
Antonio Castaldini ◽  
Filippo Nava ◽  
Paolo Errani ◽  
Vladimir Cindro
Keyword(s):  
Deep Level ◽  
Collection Efficiency ◽  
Deep Levels ◽  
Charge Collection ◽  
Charge Collection Efficiency ◽  
Temperature Range ◽  
Order Of Magnitude ◽  
Irradiation Level ◽  
Transient Spectroscopy ◽  
Induced Defects

AbstractWe investigated the electronic levels of defects introduced in 4H-SiC α-particle detectors by irradiation with 1 MeV neutrons up to a fluence equal to 8x1015 n/cm2. As well, we investigated their effect on the detector radiation hardness. This study was carried out by deep level transient spectroscopy (DLTS) and photo-induced current transient spectroscopy (PICTS). As the irradiation level approaches fluences in the order of 1015 n/cm2, the material behaves as highly resistive due to a very great compensation effect but the diodes are still able to detect with a acceptably good charge collection efficiency (CCE) equal to 80%. By further increasing fluence, CCE decreases reaching the value of ≈ 20% at fluence of 8x1015 n/cm2.The dominant peaks in the PICTS spectra occur in the temperature range [400, 700] K. Enthalpy, capture cross-section and order of magnitude of the density of such deep levels were calculated. In the above said temperature range the deep levels associated to the radiation induced defects play the key role in the degradation of the CCE. Two deep levels at Et = 1.18 eV and Et = 1.50 eV are likely to be responsible of such dramatic decrease of the charge collection efficiency. These levels were reasonably associated to an elementary defect involving a carbon vacancy and to a defect complex involving a carbon and a silicon vacancy, respectively.

The Transonic Flow Through a Plane Turbine Cascade as Measured in Four European Wind Tunnels

1986 ◽  
Vol 108 (2) ◽  
pp. 277-284 ◽  
Author(s):  
R. Kiock ◽  
F. Lehthaus ◽  
N. C. Baines ◽  
C. H. Sieverding
Keyword(s):  
Transonic Flow ◽  
High Speed ◽  
Turbine Rotor ◽  
Wind Tunnels ◽  
Test Results ◽  
Turbine Rotor Blade ◽  
Pressure Distributions ◽  
Order Of Magnitude ◽  
Blade Section ◽  
Flow Through

Reliable cascade data are esssential to the development of high-speed turbomachinery, but it has long been suspected that the tunnel environment influences the test results. This has now been investigated by testing one plane gas turbine rotor blade section in four European wind tunnels of different test sections and instrumentation. The Reynolds number of the transonic flow tests was Re2 = 8 × 105 based on exit flow conditions. The turbulence was not increased artificially. A comparison of results from blade pressure distributions and wake traverse measurements reveals the order of magnitude of tunnel effects.

scholarly journals Partitioning Reference Intervals by Use of Genetic Information

2011 ◽  
Vol 57 (3) ◽  
pp. 475-481 ◽  
Author(s):  
Brian H Shirts ◽  
Andrew R Wilson ◽  
Brian R Jackson
Keyword(s):  
Genetic Information ◽  
Clinical Information ◽  
Reference Interval ◽  
Reference Intervals ◽  
Genetic Effects ◽  
Test Results ◽  
Simple Method ◽  
Asian Populations ◽  
Gilbert Syndrome ◽  
Recessive Effects

BACKGROUND Reference intervals that incorporate genetic information could reduce the misidentification of unusual test results caused by non–disease-associated genetic variation and increase the detection of results indicating underlying pathology. Subdividing reference groups by genetic effects, however, may lead to increased uncertainty around reference interval endpoints (because of the smaller subgroup sample sizes), thus offsetting any benefits. METHODS We evaluated CLSI guidelines to develop a method appropriate for partitioning reference intervals on the basis of genetic variants with dominant or recessive effects. This method uses information available before reference samples are recruited, thus allowing a preliminary decision regarding partitioning to be made before sampling. We used this method to evaluate the example of Gilbert syndrome. RESULTS The decision point for partitioning occurs when the percentage of total variance attributable to a dominant or recessive genetic polymorphism exceeds 4%. Similarly, partitioning decision curves are presented based on difference in means between 2 subgroups, sample SD, and subgroup or allele frequency. Laboratory-specific partitioned reference intervals for Gilbert syndrome appear to be statistically warranted for white and African-American populations, but not for Asian populations. CONCLUSIONS We present a simple method to evaluate whether partitioning based on dominant or recessive genetic effects is statistically justified. Important limitations remain that, in many situations, will preclude integration of genetic, laboratory, and clinical information. As society moves toward personalized medicine, additional research is needed on how to evaluate patient normality while accounting for additive genetic, multigenic, and other multifactorial effects.

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