The Effect of Dilution on Microsegregation in AWS ER NiCrMo-14 Alloy Welding Claddings

NASA Astrophysics Data System (ADS)

Miná, Émerson Mendonça; da Silva, Yuri Cruz; Dille, Jean; Silva, Cleiton Carvalho

2016-12-01

Dilution and microsegregation are phenomena inherent to claddings, which, in turn, directly affect their main properties. This study evaluated microsegregation in the fusion zone with different dilution levels. The overlays were welded by the TIG cold wire feed process. Dilution was calculated from the geometric characteristics of the claddings and from the conservation of mass equation using chemical composition measurements. Microsegregation was calculated using energy dispersive X-ray spectroscopy measurements of the dendrites and the chemical composition of the fusion zone. The dilution of the claddings was increased by reducing the wire feed rate. Fe showed potential to be incorporated into the solid phase ( k > 1), and this increased with the increase of dilution. Mo, in turn, was segregated into the liquid phase ( k < 1) and also increased with the increase of dilution. However, Cr and W showed a slight decrease in their partition coefficients ( k) with the increase of dilution.

Nanoparticles and Ocean Optics

DTIC Science & Technology

2005-09-30

ANSI Std Z39-18 control infection by the dilution process. Subsequent dilution experiments used eukaryotic hosts ( Emiliania huxleyi) and its...Results of dilution experiment with Emiliania huxleyi (strain 88E) and its virus. In this experiment, infection rate is controlled by the dilution

Helium 3/Helium 4 dilution cryocooler for space

NASA Technical Reports Server (NTRS)

Hendricks, John B.; Dingus, Michael L.

1991-01-01

Prototype dilution cryocoolers based on dilution refrigeration and adiabatic demagnetization refrigeration (ADR) cycles were designed, constructed, and tested. Although devices the devices did not operate as fully functional dilution cryocoolers, important information was gathered. The porous metal phase separator was demonstrated to operate in the -1-g configuration; this phase separation is the critical element in the He-3 circulation dilution cryocooler. Improvements in instrumentation needed for additional tests and development were identified.

Serial Dilution Simulation Lab

ERIC Educational Resources Information Center

Keler, Cynthia; Balutis, Tabitha; Bergen, Kim; Laudenslager, Bryanna; Rubino, Deanna

2010-01-01

Serial dilution is often a difficult concept for students to understand. In this short dry lab exercise, students perform serial dilutions using seed beads. This exercise helps students gain skill at performing dilutions without using reagents, bacterial cultures, or viral cultures, while being able to visualize the process.

Infectivity and RNA patterns as functions of high- and low-dilution passage of murine sarcoma-leukemia virus: evidence for autointerference within an oncornavirus population.

PubMed

Bondurant, M C; Hackett, A J; Schaffer, F L

1973-05-01

Heterogeneity of buoyant density and RNA content of virions of Moloney murine leukemia-sarcoma complex [MSV (MLV)] was the result of passage at low dilution. Heterogeneous stocks revealed two major RNA components in the population, with the smaller component, apparent mol wt 4 x 10(6) to 5 x 10(6), becoming predominant upon serial passage at low dilution. Concomitantly, infectivity titers of both MLV and MSV decreased upon serial passage at low dilution. MSV (MLV) passaged at high dilution retained high titers and a rather homogeneous high-molecular-weight RNA population characteristic of high-buoyant-density virions. Interference of both MLV and MSV replication was demonstrated by employing mixed inocula containing both low- and high-dilution passage stocks of MSV (MLV). In contrast to results with MSV (MLV), MLV freed of MSV by limit dilution did not show heterogeneity of buoyant density or of RNA when propagated at low dilution.

Infectivity and RNA Patterns as Functions of High- and Low-Dilution Passage of Murine Sarcoma-Leukemia Virus: Evidence for Autointerference Within an Oncornavirus Population

PubMed Central

Bondurant, M. C.; Hackett, A. J.; Schaffer, F. L.

1973-01-01

Heterogeneity of buoyant density and RNA content of virions of Moloney murine leukemia-sarcoma complex [MSV (MLV)] was the result of passage at low dilution. Heterogeneous stocks revealed two major RNA components in the population, with the smaller component, apparent mol wt 4 × 106 to 5 × 106, becoming predominant upon serial passage at low dilution. Concomitantly, infectivity titers of both MLV and MSV decreased upon serial passage at low dilution. MSV (MLV) passaged at high dilution retained high titers and a rather homogeneous high-molecular-weight RNA population characteristic of high-buoyant-density virions. Interference of both MLV and MSV replication was demonstrated by employing mixed inocula containing both low- and high-dilution passage stocks of MSV (MLV). In contrast to results with MSV (MLV), MLV freed of MSV by limit dilution did not show heterogeneity of buoyant density or of RNA when propagated at low dilution. PMID:4350709

Diluting the burden of load: perceptual load effects are simply dilution effects.

PubMed

Tsal, Yehoshua; Benoni, Hanna

2010-12-01

The substantial distractor interference obtained for small displays when the target appears alone is reduced in large displays when the target is embedded among neutral letters. This finding has been interpreted as reflecting low-load and high-load processing, respectively, thereby supporting the theory of perceptual load (Lavie & Tsal, 1994). However, a possible alternative interpretation of this effect is that the distractor is similarly processed in both displays, yet its interference in the large ones is diluted by the presence of the neutral letters. We separated the effects of load and dilution by introducing dilution displays. They contained as many letters as the high-load displays but were clearly distinguished from the target, thus allowing for a low-load processing mode. Distractor interference obtained under both the low-load and high-load conditions disappeared under the dilution condition. Hence, the display size effect traditionally misattributed to perceptual load is fully accounted for by dilution. Furthermore, when dilution is controlled for, it is high load not low load producing greater interference.

[A.I. in pigs: influence of boar seminal plasma on breeding efficiency of diluted boar semen (author's transl)].

PubMed

Meding, J H

1976-01-01

Ejaculates from six boars of Danish Landrace were divided into four parts, I, II, III and IV which were treated in the following way: I was diluted 1:4-1:6 with EDTA-diluter, and filled into glass vials (single doses). II was centrifugated at 1800-2000 r.p.m. in 12-15 min.; the centifugate was resuspended in the supernatant and diluted as indicated under I. III and IV were centrifugated at 1800-2000 r.p.m. in 12-15 min. The supernatant was removed by aspiration and the centrifugate diluted with as much EDTA-diluter necessary to produce the same no, of doses of 10 ml as was produced from I and II respectively. The diluted semen was stored at 18-20 degrees C and used on the day of collection. Just before insemination the semen from I, II and III was diluted with IVT-diluter to a final volume of 75 ml. Semen from IV was diluted to the same volume with IVT-diluter with the addition of 50% boar seminal plasma, procured by centrifugation of ejaculates from other boars of the A.I. Centre, and stored at divided by 20 degrees C until use. The results have been set out in Table I. Inseminations with semen from I and II resulted in pregnancy rates of 84,6% and 86,3% and average litter sizes of 10,3 and 10,1 for sows and 9,1 and 9,6 for gilts; inseminations with semen from III and IV resulted in pregnancy rates of 78,9 and 78,2% and average litter sizes of 10,5 and 10,7 for sows and 10,0 and 8,7 for gilts. None of the differences in pregnancy rates between groups were significant. The findings were: 1. By insemination with initially diluted semen without seminal plasma a tendency to a decline in pregnancy rates could be demonstrated. 2. The decline persisted after the addition of 50% boar seminal plasma to the diluter used for the final dilution just before insemination.

Apparatus and method for maintaining multi-component sample gas constituents in vapor phase during sample extraction and cooling

DOEpatents

Felix, Larry Gordon; Farthing, William Earl; Irvin, James Hodges; Snyder, Todd Robert

2010-05-11

A dilution apparatus for diluting a gas sample. The apparatus includes a sample gas conduit having a sample gas inlet end and a diluted sample gas outlet end, and a sample gas flow restricting orifice disposed proximate the sample gas inlet end connected with the sample gas conduit and providing fluid communication between the exterior and the interior of the sample gas conduit. A diluted sample gas conduit is provided within the sample gas conduit having a mixing end with a mixing space inlet opening disposed proximate the sample gas inlet end, thereby forming an annular space between the sample gas conduit and the diluted sample gas conduit. The mixing end of the diluted sample gas conduit is disposed at a distance from the sample gas flow restricting orifice. A dilution gas source connected with the sample gas inlet end of the sample gas conduit is provided for introducing a dilution gas into the annular space, and a filter is provided for filtering the sample gas. The apparatus is particularly suited for diluting heated sample gases containing one or more condensable components.

Toxicity of contaminated sediments in dilution series with control sediments

USGS Publications Warehouse

Nelson, M.K.; Landrum, P.F.; Burton, G.A.; Klaine, S.J.; Crecelius, E.A.; Byl, T.D.; Gossiaux, Duane C.; Tsymbal, V.N.; Cleveland, L.; Ingersoll, Christopher G.; Sasson-Brickson, G.

1993-01-01

The use of dilutions has been the foundation of our approach for assessing contaminated water, and accordingly, it may be important to establish similar or parallel approaches for sediment dilutions. Test organism responses to dilution gradients can identify the degree of necessary sediment alteration to reduce the toxicity. Using whole sediment dilutions to represent the complex interactions of in situ sediments can identify the toxicity, but the selection of the appropriate diluent for the contaminated sediment may affect the results and conclusions drawn. Contaminated whole sediments were examined to evaluate the toxicity of dilutions of sediments with a diversity of test organisms. Dilutions of the contaminated sediments were prepared with differing diluents that varied in organic carbon content, particle size distribution, and volatile solids. Studies were conducted using four macroinvertebrates and a vascular, rooted plant. Responses by some test organisms followed a sigmoidal dose-response curve, but others followed a U-shaped curve. Initial dilutions reduced toxicity as expected, but further dilution resulted in an increase in toxicity. The type of diluent used was an important factor in assessing the sediment toxicity, because the control soil reduced toxicity more effectively than sand as a diluent of the same sediment. Using sediment chemical and physical characteristics as an indicator of sediment dilution may not be as useful as chemical analysis of contaminants, but warrants further investigation.

Upfront dilution of ferritin samples to reduce hook effect, improve turnaround time and reduce costs.

PubMed

Wu, Shu Juan; Hayden, Joshua A

2018-02-15

Sandwich immunoassays offer advantages in the clinical laboratory but can yield erroneously low results due to hook (prozone) effect, especially with analytes whose concentrations span several orders of magnitude such as ferritin. This study investigated a new approach to reduce the likelihood of hook effect in ferritin immunoassays by performing upfront, five-fold dilutions of all samples for ferritin analysis. The impact of this change on turnaround time and costs were also investigated. Ferritin concentrations were analysed in routine clinical practice with and without upfront dilutions on Siemens Centaur® XP (Siemens Healthineers, Erlang, Germany) immunoanalysers. In addition, one month of baseline data (1026 results) were collected prior to implementing upfront dilutions and one month of data (1033 results) were collected after implementation. Without upfront dilutions, hook effect was observed in samples with ferritin concentrations as low as 86,028 µg/L. With upfront dilutions, samples with ferritin concentrations as high as 126,050 µg/L yielded values greater than the measurement interval and would have been diluted until an accurate value was obtained. The implementation of upfront dilution of ferritin samples led to a decrease in turnaround time from a median of 2 hours and 3 minutes to 1 hour and 18 minutes (P = 0.002). Implementation of upfront dilutions of all ferritin samples reduced the possibility of hook effect, improved turnaround time and saved the cost of performing additional dilutions.

A noncoding melanophilin gene (MLPH) SNP at the splice donor of exon 1 represents a candidate causal mutation for coat color dilution in dogs.

PubMed

Drögemüller, Cord; Philipp, Ute; Haase, Bianca; Günzel-Apel, Anne-Rose; Leeb, Tosso

2007-01-01

Coat color dilution in several breeds of dog is characterized by a specific pigmentation phenotype and sometimes accompanied by hair loss and recurrent skin inflammation, the so-called color dilution alopecia or black hair follicular dysplasia. Coat color dilution (d) is inherited as a Mendelian autosomal recessive trait. In a previous study, MLPH polymorphisms showed perfect cosegregation with the dilute phenotype within breeds. However, different dilute haplotypes were found in different breeds, and no single polymorphism was identified in the coding sequence that was likely to be causative for the dilute phenotype. We resequenced the 5'-region of the canine MLPH gene and identified a strong candidate single nucleotide polymorphism within the nontranslated exon 1, which showed perfect association to the dilute phenotype in 65 dilute dogs from 7 different breeds. The A/G polymorphism is located at the last nucleotide of exon 1 and the mutant A-allele is predicted to reduce splicing efficiency 8-fold. An MLPH mRNA expression study using quantitative reverse transcriptase-polymerase chain reaction confirmed that dd animals had only about approximately 25% of the MLPH transcript compared with DD animals. These results provide preliminary evidence that the reported regulatory MLPH mutation might represent a causal mutation for coat color dilution in dogs.

Dilution in single pass arc welds

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

DuPont, J.N.; Marder, A.R.

1996-06-01

A study was conducted on dilution of single pass arc welds of type 308 stainless steel filler metal deposited onto A36 carbon steel by the plasma arc welding (PAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), and submerged arc welding (SAW) processes. Knowledge of the arc and melting efficiency was used in a simple energy balance to develop an expression for dilution as a function of welding variables and thermophysical properties of the filler metal and substrate. Comparison of calculated and experimentally determined dilution values shows the approach provides reasonable predictions of dilution when the melting efficiencymore » can be accurately predicted. The conditions under which such accuracy is obtained are discussed. A diagram is developed from the dilution equation which readily reveals the effect of processing parameters on dilution to aid in parameter optimization.« less

40 CFR 1065.240 - Dilution air and diluted exhaust flow meters.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements... interval. You may use the difference between a diluted exhaust flow meter and a dilution air meter to... compression-ignition engines, 2-stroke spark-ignition engines, and 4-stroke spark-ignition engines below 19 kW...

40 CFR 1065.240 - Dilution air and diluted exhaust flow meters.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements... interval. You may use the difference between a diluted exhaust flow meter and a dilution air meter to... compression-ignition engines, two-stroke spark-ignition engines, or four-stroke spark-ignition engines at or...

40 CFR 1065.240 - Dilution air and diluted exhaust flow meters.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements... interval. You may use the difference between a diluted exhaust flow meter and a dilution air meter to... compression-ignition engines, 2-stroke spark-ignition engines, and 4-stroke spark-ignition engines below 19 kW...

40 CFR 1065.240 - Dilution air and diluted exhaust flow meters.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements... interval. You may use the difference between a diluted exhaust flow meter and a dilution air meter to... compression-ignition engines, 2-stroke spark-ignition engines, and 4-stroke spark-ignition engines below 19 kW...

21 CFR 864.5240 - Automated blood cell diluting apparatus.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Automated blood cell diluting apparatus. 864.5240 Section 864.5240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... § 864.5240 Automated blood cell diluting apparatus. (a) Identification. An automated blood cell diluting...

21 CFR 864.5240 - Automated blood cell diluting apparatus.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automated blood cell diluting apparatus. 864.5240 Section 864.5240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... § 864.5240 Automated blood cell diluting apparatus. (a) Identification. An automated blood cell diluting...

21 CFR 864.5240 - Automated blood cell diluting apparatus.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Automated blood cell diluting apparatus. 864.5240 Section 864.5240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... § 864.5240 Automated blood cell diluting apparatus. (a) Identification. An automated blood cell diluting...

Science Notes: Dilution of a Weak Acid

ERIC Educational Resources Information Center

Talbot, Christopher; Wai, Chooi Khee

2014-01-01

This "Science note" arose out of practical work involving the dilution of ethanoic acid, the measurement of the pH of the diluted solutions and calculation of the acid dissociation constant, K[subscript a], for each diluted solution. The students expected the calculated values of K[subscript a] to be constant but they found that the…

Use of laser-induced spark for studying ignition stability and unburned hydrogen escaping from laminar diluted hydrogen diffusion jet flames

NASA Astrophysics Data System (ADS)

Phuoc, Tran X.; Chen, Ruey-Hung

2007-08-01

Ignition and unburned hydrogen escaping from hydrogen jet diffusion flames diluted with nitrogen up to 70% were experimentally studied. The successful ignition locations were about 2/3 of the flame length above the jet exit for undiluted flames and moved much closer to the exit for diluted flames. For higher levels of dilution or higher flow rates, there existed a region within which a diluted hydrogen diffusion flame can be ignited and burns with a stable liftoff height. This is contrary to previous findings that pure and diluted hydrogen jet diffusion cannot achieve a stable lifted flame configuration. With liftoff, the flame is noisy and short with significant amount of unburned hydrogen escaping into the product gases. If ignition is initiated below this region, the flame propagates upstream quickly and attaches to the burner rim. Results from measurements of unburned hydrogen in the combustion products showed that the amount of unburned hydrogen increased as the nitrogen dilution level was increased. Thus, hydrogen diffusion flame diluted with nitrogen cannot burn completely.

Effects of diluting medium and holding time on sperm motility analysis by CASA in ram.

PubMed

Mostafapor, Somayeh; Farrokhi Ardebili, Farhad

2014-01-01

The aim of this study was to evaluate the effects of dilution rate and holding time on various motility parameters using computer-assisted sperm analysis (CASA). The semen samples were collected from three Ghezel rams. Samples were diluted in seminal plasma (SP), phosphate-buffered saline (PBS) containing 1% bovine serum albumin (BSA) and Bioexcell. The motility parameters that computed and recorded by CASA include curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), straightness (STR), linearity (LIN), amplitude of lateral head displacement (ALH), and beat cross frequency (BCF). In all diluters, there was a decrease in the average of all three parameters of sperms movement velocity as the time passed, but density of this decrease was more intensive in SP. The average of ALH between diluters indicated a significant difference, as it was more in Bioexcell in comparison with the similar amount in SP and PBS. The average of LIN in the diluted sperms in Bioexcell was less than two other diluters in all three times. The motility parameters of the diluted sperms in Bioexcell and PBS indicated an important and considerable difference with the diluted sperms in SP. According to the gained results, the Bioexcell has greater ability in preserving motility of sperm in comparison with the other diluters but as SP is considered as physiological environment for sperm. It seems that the evaluation of the motility parameters in Bioexcell and PBS cannot be an accurate and comparable evaluation with SP.

A method for predicting optimized processing parameters for surfacing

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

Dupont, J.N.; Marder, A.R.

1994-12-31

Welding is used extensively for surfacing applications. To operate a surfacing process efficiently, the variables must be optimized to produce low levels of dilution with the substrate while maintaining high deposition rates. An equation for dilution in terms of the welding variables, thermal efficiency factors, and thermophysical properties of the overlay and substrate was developed by balancing energy and mass terms across the welding arc. To test the validity of the resultant dilution equation, the PAW, GTAW, GMAW, and SAW processes were used to deposit austenitic stainless steel onto carbon steel over a wide range of parameters. Arc efficiency measurementsmore » were conducted using a Seebeck arc welding calorimeter. Melting efficiency was determined based on knowledge of the arc efficiency. Dilution was determined for each set of processing parameters using a quantitative image analysis system. The pertinent equations indicate dilution is a function of arc power (corrected for arc efficiency), filler metal feed rate, melting efficiency, and thermophysical properties of the overlay and substrate. With the aid of the dilution equation, the effect of processing parameters on dilution is presented by a new processing diagram. A new method is proposed for determining dilution from welding variables. Dilution is shown to depend on the arc power, filler metal feed rate, arc and melting efficiency, and the thermophysical properties of the overlay and substrate. Calculated dilution levels were compared with measured values over a large range of processing parameters and good agreement was obtained. The results have been applied to generate a processing diagram which can be used to: (1) predict the maximum deposition rate for a given arc power while maintaining adequate fusion with the substrate, and (2) predict the resultant level of dilution with the substrate.« less

Just add water: Accuracy of analysis of diluted human milk samples using mid-infrared spectroscopy.

PubMed

Smith, R W; Adamkin, D H; Farris, A; Radmacher, P G

2017-01-01

To determine the maximum dilution of human milk (HM) that yields reliable results for protein, fat and lactose when analyzed by mid-infrared spectroscopy. De-identified samples of frozen HM were obtained. Milk was thawed and warmed (40°C) prior to analysis. Undiluted (native) HM was analyzed by mid-infrared spectroscopy for macronutrient composition: total protein (P), fat (F), carbohydrate (C); Energy (E) was calculated from the macronutrient results. Subsequent analyses were done with 1 : 2, 1 : 3, 1 : 5 and 1 : 10 dilutions of each sample with distilled water. Additional samples were sent to a certified lab for external validation. Quantitatively, F and P showed statistically significant but clinically non-critical differences in 1 : 2 and 1 : 3 dilutions. Differences at higher dilutions were statistically significant and deviated from native values enough to render those dilutions unreliable. External validation studies also showed statistically significant but clinically unimportant differences at 1 : 2 and 1 : 3 dilutions. The Calais Human Milk Analyzer can be used with HM samples diluted 1 : 2 and 1 : 3 and return results within 5% of values from undiluted HM. At a 1 : 5 or 1 : 10 dilution, however, results vary as much as 10%, especially with P and F. At the 1 : 2 and 1 : 3 dilutions these differences appear to be insignificant in the context of nutritional management. However, the accuracy and reliability of the 1 : 5 and 1 : 10 dilutions are questionable.

The Effect of Albumin and Platelet-Poor Plasma Supplemented Botulinum A Toxin on Bioavaliability: An Experimental Rabbit Model.

PubMed

Sibar, Serhat; Findikcioglu, Kemal; Zinnuroglu, Murat; Cenetoglu, Seyhan

2017-04-01

Today, botulinum toxin is commonly used for cosmetic purposes throughout the world. Despite various agents reducing the efficiency of toxin are well defined, the studies related to increasing the bioavailability are limited. The purpose of our study is to assess the effect of the preparation of toxin by diluting with platelet-poor plasma (PPP) and/or albumin instead of standard dilution (saline) on bioavailability in cosmetic-purpose botulinum toxin applications.In the study, 24 New Zealand rabbits were used. Right anterior auricular muscle was preferred for toxin injections. Subjects were divided in 4 groups and in every group; botulinum A toxin (BTxA) that was prepared by different dilution methods was injected. 2.5 U saline-diluted BTxA was injected to the subjects in group 1, 2.5 U ready-to-use rabbit albumin-diluted BTxA was injected to group 2 and 2.5 U autologous PPP-diluted BTxA was injected to group 3 and pure saline was injected to group 4.Before the injection (0th week) and in the second, sixth, and 12th weeks after the injection, visual and electroneuromyographic evaluations of the ears of the subjects were performed.In the second week, median amplitude levels in group 2 were significantly found lower than other groups.In the sixth week, median amplitude levels in group 1 were significantly found lower than other groups.In 12th week, no significant difference was found among all the groups in terms of median amplitude levels.Visual findings were also correlated with electroneuromyographic findings.It was observed that the dilution of BTxA with albumin had caused a stronger paralysis when compared to dilution with saline or PPP at the beginning (second week); however, in the following weeks (sixth week), it was seen that dilution with saline had maintained paralysis better when compared with other dilution methods.In cosmetic BTxA applications, dilution of the toxin with albumin or PPP instead of standard dilution has no positive effect on bioavailability and such modifications regarding this kind of dilution are found unsuitable. Further studies are needed to directly relate the results with clinical applications.

Method and apparatus for maintaining multi-component sample gas constituents in vapor phase during sample extraction and cooling

DOEpatents

Farthing, William Earl [Pinson, AL; Felix, Larry Gordon [Pelham, AL; Snyder, Todd Robert [Birmingham, AL

2008-02-12

An apparatus and method for diluting and cooling that is extracted from high temperature and/or high pressure industrial processes. Through a feedback process, a specialized, CFD-modeled dilution cooler is employed along with real-time estimations of the point at which condensation will occur within the dilution cooler to define a level of dilution and diluted gas temperature that results in a gas that can be conveyed to standard gas analyzers that contains no condensed hydrocarbon compounds or condensed moisture.

Method and apparatus maintaining multi-component sample gas constituents in vapor phase during sample extraction and cooling

DOEpatents

Farthing, William Earl; Felix, Larry Gordon; Snyder, Todd Robert

2009-12-15

An apparatus and method for diluting and cooling that is extracted from high temperature and/or high pressure industrial processes. Through a feedback process, a specialized, CFD-modeled dilution cooler is employed along with real-time estimations of the point at which condensation will occur within the dilution cooler to define a level of dilution and diluted gas temperature that results in a gas that can be conveyed to standard gas analyzers that contains no condensed hydrocarbon compounds or condensed moisture.

EMJH medium with 5-fluorouracil and nalidixic acid associated with serial dilution technique used to recover Leptospira spp from experimentally contaminated bovine semen

PubMed Central

Miraglia, Fabiana; de Moraes, Zenaide Maria; Melville, Priscilla Anne; Dias, Ricardo Augusto; Vasconcellos, Silvio Arruda

2009-01-01

Bovine semen experimentally contaminated with Leptospira santarosai serovar Guaricura was submitted to the modified EMJH medium with 5-fluorouracil (300mg/L) and nalidixic acid (20mg/L), named as “selective medium” and using the serial dilution technique, in order to evaluate the percentage of recovery of the added microorganism. The selective EMJH medium was found with higher percentage of recovery of leptospiras and minor losses of samples due to contamination with opportunistic microorganisms than the non-selective EMJH medium: 151/376 (40.0%) of positive growth; and 38/376 (10.0%) contamination and 58/376 (15%) and 129/376 (34.0%), respectively. These results were statistically significant (p<0. 0001; Fisher). Differences were found when the frequencies of positive leptospires recovery have been compared in the serial dilution technique (10-1 to 10-4) between the selective and non-selective media at different dilution factors. At 1/10th dilution the percentages found were (0%, 0/80) and (38%, 30/80), at 1/100th dilution, (3%, 2/80) and (49%, 39/ 80) and at 1/1,000th dilution, (25%, 20/80) and (50%, 40/80), respectively. The percentage of recovery of leptospires was found to be directly proportional to the dilution used. The methodology of the serial dilution technique (setting at least three dilutions) and the use of selective EMJH medium have been found to be efficient for the isolation of leptospires from the bovine semen samples. PMID:24031342

[Diagnostic contribution of abnormal delayed-type hypersensitivity to Candida albicans. Characterization test by activation of cells sensitized to successive dilutions of Candida].

PubMed

Brunet, J L; Cozon, G; Sainte-Laudy, J; Boissel, J P; Delair, S; Peyramond, D

1997-10-01

By measuring the activation of different cell models (lymphocytes and lymphocytic subsets) in the presence of Candida albicans with flow cytometry reading, it is possible to show that successive dilutions of Candida albicans can lead to lymphocyte activation in abnormally-sensitized subjects. In a first trial, 10 subjects were tested in duplicate. The decrease of activity of the dilutions does not appear to be regular in relation to the progression of the dilutions. The activity of the dilutions wanes relatively rapidly with the first dilutions, then recurs later very distinctly, at the 6th dilution, then ebbs, then reappears in similar manner at the 9th, the 14th, and finally, the 19th dilution. Cell reactivity appears to differ depending on the subject. It can be represented through the calculated slope of the regression line, for each series of data. It therefore appears feasible to determine a threshold of reactivity and a scale of sensitivity, to make it possible to specify the degree of abnormal reactivity existing at a given time for a given subject. The constancy of the activity of the different dilutions tested, on 10 cultures of a single cell suspension, is especially well demonstrated in the second trial, showing unusually small standard deviations. Thus, the question arises as to the exact nature of the observed phenomenon and of its analysis from a physical-chemical point of view, with regard to the pharmacological effect of successive dilutions of Candida albicans.

Two-Exon Skipping within MLPH Is Associated with Coat Color Dilution in Rabbits

PubMed Central

Lehner, Stefanie; Gähle, Marion; Dierks, Claudia; Stelter, Ricarda; Gerber, Jonathan; Brehm, Ralph; Distl, Ottmar

2013-01-01

Coat color dilution turns black coat color to blue and red color to cream and is a characteristic in many mammalian species. Matings among Netherland Dwarf, Loh, and Lionhead Dwarf rabbits over two generations gave evidence for a monogenic autosomal recessive inheritance of coat colour dilution. Histological analyses showed non-uniformly distributed, large, agglomerating melanin granules in the hair bulbs of coat color diluted rabbits. We sequenced the cDNA of MLPH in two dilute and one black rabbit for polymorphism detection. In both color diluted rabbits, skipping of exons 3 and 4 was present resulting in altered amino acids at p.QGL[37-39]QWA and a premature stop codon at p.K40*. Sequencing of genomic DNA revealed a c.111-5C>A splice acceptor mutation within the polypyrimidine tract of intron 2 within MLPH. This mutation presumably causes skipping of exons 3 and 4. In 14/15 dilute rabbits, the c.111-5C>A mutation was homozygous and in a further dilute rabbit, heterozygous and in combination with a homozygous frame shift mutation within exon 6 (c.585delG). In conclusion, our results demonstrated a colour dilution associated MLPH splice variant causing a strongly truncated protein (p.Q37QfsX4). An involvement of further MLPH-associated mutations needs further investigations. PMID:24376820

Mid-dilution hemodiafiltration: a comparison with pre- and postdilution modes using the same polyphenylene membrane.

PubMed

Maduell, Francisco; Arias, Marta; Vera, Manel; Fontseré, Néstor; Blasco, Miquel; Barros, Xoana; Garro, Julia; Elena, Montserrat; Bergadá, Eduardo; Cases, Aleix; Bedini, Jose Luis; Campistol, Josep M

2009-01-01

As a change from Diapes to polyphenylene membrane in the mid-dilution filter has recently been developed, the aim of this study was to compare mid-dilution using this new dialyzer versus pre- and postdilution. The prospective study included 20 patients who underwent 4 hemodiafiltration (HDF) sessions: 1.7 m(2) polyphenylene and predilution infusion flow (Qi) 200 ml/min, 1.7 m(2) and postdilution Qi 100 ml/min, 1.9 and 2.2 m(2) mid-dilution both with Qi 200 ml/ min. The urea and creatinine reduction ratios were slightly higher in postdilution. The beta(2)-microglobulin (85.8%), myoglobin (73.6%), prolactin (67.8%) and retinol-binding protein (29.2%) reduction ratios with 1.9 m(2) mid-dilution, which was similar to 2.2 m(2) mid-dilution, were significantly higher than with the post- and predilution modes. Mid-dilution appears to be a good HDF alternative that allows a better removal of larger molecules than postdilution and, mainly, predilution. Mid-dilution using 1.9 or 2.2 m(2) dialyzers, at the same convective volume, showed a similar removal. Copyright 2009 S. Karger AG, Basel.

Use of diluted urine for cultivation of Chlorella vulgaris.

PubMed

Jaatinen, Sanna; Lakaniemi, Aino-Maija; Rintala, Jukka

2016-01-01

Our aim was to study the biomass growth of microalga Chlorella vulgaris using diluted human urine as a sole nutrient source. Batch cultivations (21 days) were conducted in five different urine dilutions (1:25-1:300), in 1:100-diluted urine as such and with added trace elements, and as a reference, in artificial growth medium. The highest biomass density was obtained in 1:100-diluted urine with and without additional trace elements (0.73 and 0.60 g L(-1), respectively). Similar biomass growth trends and densities were obtained with 1:25- and 1:300-diluted urine (0.52 vs. 0.48 gVSS L(-1)) indicating that urine at dilution 1:25 can be used to cultivate microalgal based biomass. Interestingly, even 1:300-diluted urine contained sufficiently nutrients and trace elements to support biomass growth. Biomass production was similar despite pH-variation from < 5 to 9 in different incubations indicating robustness of the biomass growth. Ammonium formation did not inhibit overall biomass growth. At the beginning of cultivation, the majority of the biomass consisted of living algal cells, while towards the end, their share decreased and the estimated share of bacteria and cell debris increased.

Optimization of single plate-serial dilution spotting (SP-SDS) with sample anchoring as an assured method for bacterial and yeast cfu enumeration and single colony isolation from diverse samples.

PubMed

Thomas, Pious; Sekhar, Aparna C; Upreti, Reshmi; Mujawar, Mohammad M; Pasha, Sadiq S

2015-12-01

We propose a simple technique for bacterial and yeast cfu estimations from diverse samples with no prior idea of viable counts, designated as single plate-serial dilution spotting (SP-SDS) with the prime recommendation of sample anchoring (10 0 stocks). For pure cultures, serial dilutions were prepared from 0.1 OD (10 0 ) stock and 20 μl aliquots of six dilutions (10 1 -10 6 ) were applied as 10-15 micro-drops in six sectors over agar-gelled medium in 9-cm plates. For liquid samples 10 0 -10 5 dilutions, and for colloidal suspensions and solid samples (10% w/v), 10 1 -10 6 dilutions were used. Following incubation, at least one dilution level yielded 6-60 cfu per sector comparable to the standard method involving 100 μl samples. Tested on diverse bacteria, composite samples and Saccharomyces cerevisiae , SP-SDS offered wider applicability over alternative methods like drop-plating and track-dilution for cfu estimation, single colony isolation and culture purity testing, particularly suiting low resource settings.

Further studies on rapid dilution and warming of boar semen.

PubMed

Bamba, K; Cran, D G

1988-03-01

Studies have been carried out to investigate factors related to the induction of warm shock in boar spermatozoa. Rapid dilution per se caused visible damage to acrosomes when the sample contained 7.5% or more glycerol. This dilution effect was greater at lower temperatures. Acrosomal damage was greatly reduced by raising the dilution temperature from 15 to 25 degrees C, suggesting that a change in the physico-chemical characteristics of the acrosomal membrane occurred between these temperatures. During rapid dilution with warming, the dilution rate, the magnitude of the temperature change and the terminal temperature had a significant influence on acrosomal integrity; a terminal temperature of 35 degrees C was much more detrimental than one of 25 degrees C. The first sign of acrosomal damage was observed 15 sec after rapid dilution + warming and the damage was nearly maximal by 60 sec. An antioxidant, butylated hydroxytoluene (BHT), was effective against both rapid cooling and warming, while glycerol, dimethylsulphoxide and propylene glycol were ineffective in preventing warm shock.

Effects of dilution on elastohydrodynamic coating flow of an anti-HIV microbicide vehicle

NASA Astrophysics Data System (ADS)

Szeri, Andrew; Park, Su Chan; Tasoglu, Savas; Katz, David F.

2009-11-01

Elastohydrodynamic lubrication over soft substrates characterizes the drug delivery of anti-HIV topical microbicides carried in gel vehicles. These gels are under development to prevent HIV transmission into vulnerable vaginal mucosa during intercourse. Their effectiveness depends on completeness and durability of coating, as well as on the active ingredients. Here we investigate the influence of dilution by vaginal fluid on the coating flows that serve to protect the user. The effects of dilution by vaginal fluid simulant are assessed through rheological experiments at variable dilution of the gel vehicle. This involves determination of the way parameters in a Carreau model of a shear-thinning gel are modified by dilution. The changes in coating are determined from a computational model, based on dilution rheology measured in the laboratory. The elastohydrodynamic lubrication model of Szeri, et al. Physics of Fluids (2008) is supplemented with a convective-diffusive transport equation to handle dilution, and solved using a multi-step scheme in a moving domain.

A helium-3/helium-4 dilution cryocooler for operation in zero gravity

NASA Technical Reports Server (NTRS)

Hendricks, John B.

1988-01-01

This research effort covered the development of He-3/He-4 dilution cryocooler cycles for use in zero gravity. The dilution cryocooler is currently the method of choice for producing temperatures below 0.3 Kelvin in the laboratory. However, the current dilution cryocooler depends on gravity for their operation, so some modification is required for zero gravity operation. In this effort, we have demonstrated, by analysis, that the zero gravity dilution cryocooler is feasible. We have developed a cycle that uses He-3 circulation, and an alternate cycle that uses superfluid He-4 circulation. The key elements of both cycles were demonstrated experimentally. The development of a true 'zero-gravity' dilution cryocooler is now possible, and should be undertaken in a follow-on effort.

In vitro impairment of whole blood coagulation and platelet function by hypertonic saline hydroxyethyl starch.

PubMed

Hanke, Alexander A; Maschler, Stephanie; Schöchl, Herbert; Flöricke, Felix; Görlinger, Klaus; Zanger, Klaus; Kienbaum, Peter

2011-02-10

Hypertonic saline hydroxyethyl starch (HH) has been recommended for first line treatment of hemorrhagic shock. Its effects on coagulation are unclear. We studied in vitro effects of HH dilution on whole blood coagulation and platelet function. Furthermore 7.2% hypertonic saline, 6% hydroxyethylstarch (as ingredients of HH), and 0.9% saline solution (as control) were tested in comparable dilutions to estimate specific component effects of HH on coagulation. The study was designed as experimental non-randomized comparative in vitro study. Following institutional review board approval and informed consent blood samples were taken from 10 healthy volunteers and diluted in vitro with either HH (HyperHaes, Fresenius Kabi, Germany), hypertonic saline (HT, 7.2% NaCl), hydroxyethylstarch (HS, HAES6%, Fresenius Kabi, Germany) or NaCl 0.9% (ISO) in a proportion of 5%, 10%, 20% and 40%. Coagulation was studied in whole blood by rotation thrombelastometry (ROTEM) after thromboplastin activation without (ExTEM) and with inhibition of thrombocyte function by cytochalasin D (FibTEM), the latter was performed to determine fibrin polymerisation alone. Values are expressed as maximal clot firmness (MCF, [mm]) and clotting time (CT, [s]). Platelet aggregation was determined by impedance aggregrometry (Multiplate) after activation with thrombin receptor-activating peptide 6 (TRAP) and quantified by the area under the aggregation curve (AUC [aggregation units (AU)/min]). Scanning electron microscopy was performed to evaluate HyperHaes induced cell shape changes of thrombocytes. 2-way ANOVA for repeated measurements, Bonferroni post hoc test, p < 0.01. Dilution impaired whole blood coagulation and thrombocyte aggregation in all dilutions in a dose dependent fashion. In contrast to dilution with ISO and HS, respectively, dilution with HH as well as HT almost abolished coagulation (MCFExTEM from 57.3 ± 4.9 mm (native) to 1.7 ± 2.2 mm (HH 40% dilution; p < 0.0001) and to 6.6 ± 3.4 mm (HT 40% dilution; p < 0.0001) and thrombocyte aggregation (AUC from 1067 ± 234 AU/mm (native) to 14.5 ± 12.5 AU/mm (HH 40% dilution; p < 0.0001) and to 20.4 ± 10.4 AU/min (HT 40% dilution; p < 0.0001) without differences between HH and HT (MCF: p = 0.452; AUC: p = 0.449). HH impairs platelet function during in vitro dilution already at 5% dilution. Impairment of whole blood coagulation is significant after 10% dilution or more. This effect can be pinpointed to the platelet function impairing hypertonic saline component and to a lesser extend to fibrin polymerization inhibition by the colloid component or dilution effects.Accordingly, repeated administration and overdosage should be avoided.

In Vitro impairment of whole blood coagulation and platelet function by hypertonic saline hydroxyethyl starch

PubMed Central

2011-01-01

Background Hypertonic saline hydroxyethyl starch (HH) has been recommended for first line treatment of hemorrhagic shock. Its effects on coagulation are unclear. We studied in vitro effects of HH dilution on whole blood coagulation and platelet function. Furthermore 7.2% hypertonic saline, 6% hydroxyethylstarch (as ingredients of HH), and 0.9% saline solution (as control) were tested in comparable dilutions to estimate specific component effects of HH on coagulation. Methods The study was designed as experimental non-randomized comparative in vitro study. Following institutional review board approval and informed consent blood samples were taken from 10 healthy volunteers and diluted in vitro with either HH (HyperHaes®, Fresenius Kabi, Germany), hypertonic saline (HT, 7.2% NaCl), hydroxyethylstarch (HS, HAES6%, Fresenius Kabi, Germany) or NaCl 0.9% (ISO) in a proportion of 5%, 10%, 20% and 40%. Coagulation was studied in whole blood by rotation thrombelastometry (ROTEM) after thromboplastin activation without (ExTEM) and with inhibition of thrombocyte function by cytochalasin D (FibTEM), the latter was performed to determine fibrin polymerisation alone. Values are expressed as maximal clot firmness (MCF, [mm]) and clotting time (CT, [s]). Platelet aggregation was determined by impedance aggregrometry (Multiplate) after activation with thrombin receptor-activating peptide 6 (TRAP) and quantified by the area under the aggregation curve (AUC [aggregation units (AU)/min]). Scanning electron microscopy was performed to evaluate HyperHaes induced cell shape changes of thrombocytes. Statistics: 2-way ANOVA for repeated measurements, Bonferroni post hoc test, p < 0.01. Results Dilution impaired whole blood coagulation and thrombocyte aggregation in all dilutions in a dose dependent fashion. In contrast to dilution with ISO and HS, respectively, dilution with HH as well as HT almost abolished coagulation (MCFExTEM from 57.3 ± 4.9 mm (native) to 1.7 ± 2.2 mm (HH 40% dilution; p < 0.0001) and to 6.6 ± 3.4 mm (HT 40% dilution; p < 0.0001) and thrombocyte aggregation (AUC from 1067 ± 234 AU/mm (native) to 14.5 ± 12.5 AU/mm (HH 40% dilution; p < 0.0001) and to 20.4 ± 10.4 AU/min (HT 40% dilution; p < 0.0001) without differences between HH and HT (MCF: p = 0.452; AUC: p = 0.449). Conclusions HH impairs platelet function during in vitro dilution already at 5% dilution. Impairment of whole blood coagulation is significant after 10% dilution or more. This effect can be pinpointed to the platelet function impairing hypertonic saline component and to a lesser extend to fibrin polymerization inhibition by the colloid component or dilution effects. Accordingly, repeated administration and overdosage should be avoided. PMID:21310047

Dilutions Made Easy.

ERIC Educational Resources Information Center

Kamin, Lawrence

1996-01-01

Presents problems appropriate for high school and college students that highlight dilution methods. Promotes an understanding of dilution methods in order to prevent the unnecessary waste of chemicals and glassware in biology laboratories. (JRH)

Sample Diluter for Detecting Hypergolic Propellants and Other Toxic or Hazardous Gases

NASA Technical Reports Server (NTRS)

Barile, R. G.; Hodge, T. R.; Meneghelli, B. J.; Gursky, R.; Lueck, D. E.

1997-01-01

Hardware was developed to dilute vapor samples of purged hypergolic propellants (with air) into the range of existing instruments for detection of such toxic vapors. Since these detectors are normally used to monitor at the threshold limit value (TLV), most do not have quantitative capability at percent levels which relate to lower explosion limit (LEL) and fire hazards. For example, the upper limits of Energetic Sciences (ESI) 6000 series detectors used at KSC are 200 parts per million (ppm) for monomethyl hydrazine (MMH) and 500 ppm for nitrogen dioxide (NO2) arising from decomposition of nitrogen tetroxide (N2O4). Orbiter Processing Facility (OPF) personnel servicing Shuttle thrusters need to measure up to 250 ppm MMH and 7500 ppm NO2 with portable, intrinsically safe instruments. Our objective was to quickly fabricate a sample diluter out of existing materials as a temporary measure while other parallel efforts were conducted to provide a commercial or in-house-developed instrument to detect high propellant levels. A 3 to 1 diluter would bring 500 ppm MMH into the range of the existing fuel ESI, and a 30 to 1 diluter would do the same for NO2. In this way, familiar equipment already available would be used, resulting in minimal paperwork, safety, and training impacts and low cost. An MMH vapor sample-diluter was constructed from a 1/4-inch Kynar tee, along with specially designed lengths of sample and dilution tubing. The sample line was 3 feet of Bev-A-Line 4, 1/4 inch tube leading to the straight run of the tee. The side run of the tee had a 17-inch length of Bev-A-Line 4, 1/4-inch tube, for nominal 3 to 1 dilution. A gas sample bag was prepared and assayed at 113 ppm MMH, and diluted vapor sarnples were assayed at 39.5 ppm, or a measured dilution of 2.9 to 1. For NO2, a 316 stainless steel (SS) 1/8-inch tee with 49.5 inches of coiled, 1/8-inch outside diameter (OD) 316 SS tubing was used as the sarnpling end of the dilution system. The side run of the tee was open. The measured dilution ratio, based on the input value of 6,480 ppm NO2 and the average output value of 233 ppm, was 28 to 1. Thus, sample-diluters were successful in diluting concentrated hypergolic propellant vapors, both MMH and N2O4, into the ranges of existing TLV detectors.

Sample Diluter for Detecting Hypergolic Propellants and Other Toxic or Hazardous Gases

NASA Technical Reports Server (NTRS)

Barile, R. G.; Hodge, T. R.; Meneghelli, B. J.; Gursky, R.; Lueck, D. E.

1997-01-01

Hardware was developed to dilute vapor samples of purged hypergolic propellants (with air) into the range of existing instruments for detection of such toxic vapors. Since these detectors are normally used to monitor at the threshold limit value (TLV), most do not have quantitative capability at percent levels which relate to lower explosion limit (LEL) and fire hazards. For example, the upper limits of Energetic Sciences (ESI) 6000 series detectors used at KSC are 200 parts per million (ppm) for monomethyl hydrazine (MMH) and 500 ppm for nitrogen dioxide (NO2) arising from decomposition of nitrogen tetroxide (N2O4). Orbiter Processing Facility (OPF) personnel servicing Shuttle thrusters need to measure up to 250 ppm MMH and 7,500 ppm NO2 with portable, intrinsically safe instruments. Our objective was to quickly fabricate a sample diluter out of existing materials as a temporary measure while other parallel efforts were conducted to provide a commercial or in-house-developed instrument to detect high propellant levels. A 3 to 1 diluter would bring 500 ppm MMH into the range of the existing fuel ESI, and a 30 to 1 diluter would do the same for NO2. In this way, familiar equipment already available would be used, resulting in minimal paperwork, safety, and training impacts and low cost. An MMH vapor sample-diluter was constructed from a 1/4-inch Kynar tee, along with specially designed lengths of sample and dilution tubing. The sample line was 3 feet of Bev-A-Line 4, 1/4-inch tube leading to the straight run of the tee. The side run of the tee had a 17-inch length of Bev-A-Line 4, 1/4-inch tube, for nominal 3 to 1 dilution. A gas sample bag was prepared and assayed at 113 ppm ppm MMH, and diluted vapor samples were assayed at 39.5 ppm, or a measured dilution of 2.9 to 1. For NO2, a 316 stainless steel (SS) 1/8-inch tee with 49.5 inches of coiled, 1/8-inch outside diameter (OD) 316 SS tubing was used as the sampling end of the dilution system. The side run of the tee was open. The measured dilution ratio, based on the input value of 6,480 ppm NO2, and the average output value of 233 ppm, was 28 to 1. Thus, sample-diluters were successful in diluting concentrated hypergolic propellant vapors, both MMH and N2O4 into the ranges of existing TLV detectors.

Particles size distribution in diluted magnetic fluids

NASA Astrophysics Data System (ADS)

Yerin, Constantine V.

2017-06-01

Changes in particles and aggregates size distribution in diluted kerosene based magnetic fluids is studied by dynamic light scattering method. It has been found that immediately after dilution in magnetic fluids the system of aggregates with sizes ranging from 100 to 250-1000 nm is formed. In 50-100 h after dilution large aggregates are peptized and in the sample stationary particles and aggregates size distribution is fixed.

Evaluation of an intravenous preparation information system for improving the reconstitution and dilution process.

PubMed

Jo, Yun Hee; Shin, Wan Gyoon; Lee, Ju-Yeun; Yang, Bo Ram; Yu, Yun Mi; Jung, Sun Hoi; Kim, Hyang Sook

2016-10-01

There are very few studies reporting the impact of providing intravenous (IV) preparation information on quality use of antimicrobials, particularly regarding their reconstitution and dilution. Therefore, to improve these processes in IV antimicrobial administration, an IV preparation information system (IPIS) was implemented in a hospital. We aimed to evaluate the effect of improving reconstitution and dilution by implementing an IPIS in the electronic medical record (EMR) system. Prescriptions and activity records of nurses for injectable antimicrobials that required reconstitution and dilution for IV preparation from January 2008 to December 2013 were retrieved from EMR, and assessed based on packaging label information for reconstituting and diluting solutions. We defined proper reconstitution and dilution as occurring when the reconstitution and dilution solutions prescribed were consistent with the nurses' acting records. The types of intervention in the IPIS were as follows: a pop-up alert for proper reconstitution and passive guidance for proper dilution. We calculated the monthly proper reconstitution rate (PRR) and proper dilution rate (PDR) and evaluated the changes in these rates and trends using interrupted time series analyses. Prior to the initiation of the reconstitution alert and dilution information, the PRR and PDR were 12.7 and 46.1%, respectively. The reconstitution alert of the IPIS rapidly increased the PRR by 41% (p<0.001), after which the PRR decreased by 0.9% (p=0.013) per month after several months. However, there was no significant change in the rate or trend of the PDR during the study period. This study demonstrated that the provision of reconstitution alerts by the IPIS contributed to improving the reconstitution process of IV antimicrobial injection administration. However, providing passive information on dilution solutions was ineffective. Furthermore, solutions to ensure the continuous effectiveness of alert systems are warranted and should be actively sought. Copyright © 2016. Published by Elsevier Ireland Ltd.

Polymorphisms within the canine MLPH gene are associated with dilute coat color in dogs

PubMed Central

Philipp, Ute; Hamann, Henning; Mecklenburg, Lars; Nishino, Seiji; Mignot, Emmanuel; Günzel-Apel, Anne-Rose; Schmutz, Sheila M; Leeb, Tosso

2005-01-01

Background Pinschers and other dogs with coat color dilution show a characteristic pigmentation phenotype. The fur colors are a lighter shade, e.g. silvery grey (blue) instead of black and a sandy color (Isabella fawn) instead of red or brown. In some dogs the coat color dilution is sometimes accompanied by hair loss and recurrent skin inflammation, the so called color dilution alopecia (CDA) or black hair follicular dysplasia (BHFD). In humans and mice a comparable pigmentation phenotype without any documented hair loss is caused by mutations within the melanophilin gene (MLPH). Results We sequenced the canine MLPH gene and performed a mutation analysis of the MLPH exons in 6 Doberman Pinschers and 5 German Pinschers. A total of 48 sequence variations was identified within and between the breeds. Three families of dogs showed co-segregation for at least one polymorphism in an MLPH exon and the dilute phenotype. No single polymorphism was identified in the coding sequences or at splice sites that is likely to be causative for the dilute phenotype of all dogs examined. In 18 German Pinschers a mutation in exon 7 (R199H) was consistently associated with the dilute phenotype. However, as this mutation was present in homozygous state in four dogs of other breeds with wildtype pigmentation, it seems unlikely that this mutation is truly causative for coat color dilution. In Doberman Pinschers as well as in Large Munsterlanders with BHFD, a set of single nucleotide polymorphisms (SNPs) around exon 2 was identified that show a highly significant association to the dilute phenotype. Conclusion This study provides evidence that coat color dilution is caused by one or more mutations within or near the MLPH gene in several dog breeds. The data on polymorphisms that are strongly associated with the dilute phenotype will allow the genetic testing of Pinschers to facilitate the breeding of dogs with defined coat colors and to select against Large Munsterlanders carrying BHFD. PMID:15960853

Polymorphisms within the canine MLPH gene are associated with dilute coat color in dogs.

PubMed

Philipp, Ute; Hamann, Henning; Mecklenburg, Lars; Nishino, Seiji; Mignot, Emmanuel; Günzel-Apel, Anne-Rose; Schmutz, Sheila M; Leeb, Tosso

2005-06-16

Pinschers and other dogs with coat color dilution show a characteristic pigmentation phenotype. The fur colors are a lighter shade, e.g. silvery grey (blue) instead of black and a sandy color (Isabella fawn) instead of red or brown. In some dogs the coat color dilution is sometimes accompanied by hair loss and recurrent skin inflammation, the so called color dilution alopecia (CDA) or black hair follicular dysplasia (BHFD). In humans and mice a comparable pigmentation phenotype without any documented hair loss is caused by mutations within the melanophilin gene (MLPH). We sequenced the canine MLPH gene and performed a mutation analysis of the MLPH exons in 6 Doberman Pinschers and 5 German Pinschers. A total of 48 sequence variations was identified within and between the breeds. Three families of dogs showed co-segregation for at least one polymorphism in an MLPH exon and the dilute phenotype. No single polymorphism was identified in the coding sequences or at splice sites that is likely to be causative for the dilute phenotype of all dogs examined. In 18 German Pinschers a mutation in exon 7 (R199H) was consistently associated with the dilute phenotype. However, as this mutation was present in homozygous state in four dogs of other breeds with wildtype pigmentation, it seems unlikely that this mutation is truly causative for coat color dilution. In Doberman Pinschers as well as in Large Munsterlanders with BHFD, a set of single nucleotide polymorphisms (SNPs) around exon 2 was identified that show a highly significant association to the dilute phenotype. This study provides evidence that coat color dilution is caused by one or more mutations within or near the MLPH gene in several dog breeds. The data on polymorphisms that are strongly associated with the dilute phenotype will allow the genetic testing of Pinschers to facilitate the breeding of dogs with defined coat colors and to select against Large Munsterlanders carrying BHFD.

Avian plasma chemistry analysis using diluted samples.

PubMed

Waldoch, Jennifer; Wack, Raymund; Christopher, Mary

2009-12-01

Clinical chemistry tests are essential for the diagnosis and monitoring of disease in birds. The small volume of blood that can be obtained from many avian species limits the use of routine in-house chemistry analyzers. The aim of this study was to examine the accuracy and precision of avian plasma chemistry values obtained by use of a benchtop analyzer in samples diluted with sterile water, as compared with undiluted samples. Whole blood samples were collected from 13 clinically healthy thick-billed parrots (Rhynchopsitta pachyrhyncha). The samples were placed in lithium heparin tubes and centrifuged and the plasma decanted. One aliquot was analyzed immediately using a VetScan benchtop analyzer with an avian-reptile-specific rotor that included 12 analytes. The remainder of the plasma was divided into two aliquots and stored at -80 degrees C until analysis. One of these aliquots was diluted 1:1, 1:1.5, 1:2, and 1:2.5 with sterile water to give final dilutions of 1:2, 1:2.5, 1:3, and 1:3.5, respectively. The other aliquot was pooled with the 12 other samples to create a plasma pool. The undiluted plasma pool and two final dilutions (1:2 and 1:3) of the pooled plasma were analyzed in replicate (n = 20) to determine intra- and interassay imprecision. Each dilution was analyzed using the avian-reptile rotor and the results multiplied by the appropriate dilution factor to obtain the final result. Significant differences were observed in clinical chemistry results obtained from diluted plasma samples for all analytes except aspartate aminotransferase, creatine kinase, and glucose. Uric acid concentration was not significantly different at dilutions of up to 1:3. Bile acids, globulins, and sodium concentrations were below the limit of detection in all diluted samples and were not statistically analyzed. Based on these results, dilution with sterile water is not recommended for biochemical analysis of avian plasma using the VetScan benchtop analyzer.

Impact of different dilution techniques on boar sperm quality and sperm distribution of the extended ejaculate.

PubMed

Schulze, M; Ammon, C; Schaefer, J; Luther, A-M; Jung, M; Waberski, D

2017-07-01

The dilution of ejaculates is a fundamental step for the production of liquid-preserved boar semen. For a long time, it has been recommended to add the extender to the ejaculate. The aim of the present study was to first compare the effect of the position ('center' vs. 'wall') where the extender is added to the semen-mixing cylinder (height 32.5cm; diameter 12.7cm) using an automatic dispenser (n=11). In experiment 2 (n=30), we analyzed the two main dilution methods (extender to the semen ('control') vs. 'reverse'). Experiment 3 was carried out to study the dilution effect on kinematics. In Experiments 1 and 2, the sperm distribution 10min after the dilution and the sperm quality parameters during long-term storage (d1, d3, d5, and d7) were evaluated. In Experiment 3, sperm quality was assessed during short-term storage at 0, 10, 20, 30 and 60min after semen dilution ('control' vs. 'reverse'; n=6). There were no significant differences (P>0.05) between the treatments in the specific response to bicarbonate, mitochondrial activity, membrane status, thermo-resistance or sperm motility immediately after dilution or long-term storage. The sperm distribution was significantly (P=0.029) affected by the dilution method in Experiment 2. In summary, treatment with the extender first, which is used by only a few European boar studs, leads to comparable results in sperm quality during storage and better results in sperm distribution after dilution. This procedure is also less time consuming, less foam formation occurs during the semen dilution and the procedure is more hygienic. Copyright © 2017 Elsevier B.V. All rights reserved.

Headspace solid phase microextraction and gas chromatography-olfactometry dilution analysis of young and aged Chinese "Yanghe Daqu" liquors.

PubMed

Fan, Wenlai; Qian, Michael C

2005-10-05

The aroma compounds of young and aged Chinese "Yanghe Daqu" liquor samples were extracted by solid phase microextraction (SPME) and analyzed by gas chromatography (GC)-olfactometry dilution analysis. The original liquor samples were diluted with deionized water to give a final alcohol content of 14% (v/v). The samples were stepwise diluted (1:1) with 14% (by volume) ethanol-water solution and then extracted by headspace SPME. The samples were preequilibrated at 50 degrees C for 15 min and extracted with stirring at the same temperature for 30 min prior to injection into GC. The aroma compounds were identified by both GC-MS and GC-olfactometry using DB-Wax and DB-5 columns. The results suggested that esters were the major contributors to Yanghe Daqu liquor aroma. Ethyl hexanoate, ethyl butanoate, and ethyl pentanoate had very high flavor dilution values in both young and aged liquors (FD > 8192). Methyl hexanoate, ethyl heptanoate, ethyl benzoate, and butyl hexanoate could also be very important because of their high flavor dilution values (FD > or = 256). Moreover, two acetals, 1,1-diethoxyethane and 1,1-diethoxy-3-methylbutane, also were shown high flavor dilution values in Yanghe Daqu liquors (FD > or = 256). Other aroma compounds having moderate flavor dilution values included acetaldehyde, 3-methylbutanol, and 2-pentanol (FD > or = 32). Comparing young and aged liquors, the aroma profiles were similar, but the aroma compounds in the aged sample had higher flavor dilution values than in the young ones.

Effects of Time and Storage Conditions on the Chemical and Microbiologic Stability of Diluted Buprenorphine for Injection

PubMed Central

DenHerder, Johnathan M; Reed, Ralph L; Sargent, Jennifer L; Bobe, Gerd; Stevens, Jan F; Diggs, Helen E

2017-01-01

Buprenorphine is a partial μ-opioid agonist used for analgesia. Due to the small size of laboratory rodents, buprenorphine HCl is typically diluted 10- or 20-fold with a sterile diluent, such as saline, for accurate dosing. Protocols for preparing and storing diluted buprenorphine vary by institution, and little published information is available regarding stability and beyond-use dating of specific buprenorphine preparations. The purpose of this study was to determine the chemical and microbiologic stability of diluted buprenorphine stored for a maximum of 180 d. Buprenorphine HCl was diluted 1:10 into sterile bacteriostatic saline by using aseptic technique. Diluted samples were stored in glass vials or plastic syringes, protected from light, and maintained at refrigerated or room temperature for as long as 180 d. Aerobic and anaerobic cultures on all stored samples were negative for bacterial and fungal growth. According to HPLC analysis, diluted buprenorphine stored in glass vials experienced less than 10% loss when stored for 180 d at either refrigerated or room temperature. However, the concentration of buprenorphine stored in syringes declined rapidly to more than 80% loss at room temperature and 28% loss in the refrigerator after 180 d. According to the results of this study, diluted buprenorphine stored in glass vials retains more than 90% of the initial concentration and is microbiologically stable for 180 d. However, our data suggest that, regardless of the duration, storing diluted buprenorphine in plastic syringes is inadvisable. PMID:28724496

Optimization of coronary attenuation in coronary computed tomography angiography using diluted contrast material.

PubMed

Kawaguchi, Naoto; Kurata, Akira; Kido, Teruhito; Nishiyama, Yoshiko; Kido, Tomoyuki; Miyagawa, Masao; Ogimoto, Akiyoshi; Mochizuki, Teruhito

2014-01-01

The purpose of this study was to evaluate a personalized protocol with diluted contrast material (CM) for coronary computed tomography angiography (CTA). One hundred patients with suspected coronary artery disease underwent retrospective electrocardiogram-gated coronary CTA on a 256-slice multidetector-row CT scanner. In the diluted CM protocol (n=50), the optimal scan timing and CM dilution rate were determined by the timing bolus scan, with 20% CM dilution (5ml/s during 10s) being considered suitable to achieve the target arterial attenuation of 350 Hounsfield units (HU). In the body weight (BW)-adjusted protocol (n=50, 222mg iodine/kg), only the optimal scan timing was determined by the timing bolus scan. The injection rate and volume in the timing bolus scan and real scan were identical between the 2 protocols. We compared the means and variations in coronary attenuation between the 2 protocols. Coronary attenuation (mean±SD) in the diluted CM and BW-adjusted protocols was 346.1±23.9 HU and 298.8±45.2 HU, respectively. The diluted CM protocol provided significantly higher coronary attenuation and lower variance than did the BW-adjusted protocol (P<0.05, in each). The diluted CM protocol facilitates more uniform attenuation on coronary CTA in comparison with the BW-adjusted protocol.  

Randomly diluted eg orbital-ordered systems.

PubMed

Tanaka, T; Matsumoto, M; Ishihara, S

2005-12-31

Dilution effects on the long-range ordered state of the doubly degenerate e(g) orbital are investigated. Quenched impurities without the orbital degree of freedom are introduced in the orbital model where the long-range order is realized by the order-from-disorder mechanism. It is shown by Monte Carlo simulations and the cluster-expansion method that a decrease in the orbital-ordering temperature by dilution is substantially larger than that in the randomly diluted spin models. Tilting of orbital pseudospins around impurities is the essence of this dilution effect. The present theory provides a new viewpoint for the recent resonant x-ray scattering experiments in KCu(1-x)Zn(x)F(3).

Dilute acid/metal salt hydrolysis of lignocellulosics

DOEpatents

Nguyen, Quang A.; Tucker, Melvin P.

2002-01-01

A modified dilute acid method of hydrolyzing the cellulose and hemicellulose in lignocellulosic material under conditions to obtain higher overall fermentable sugar yields than is obtainable using dilute acid alone, comprising: impregnating a lignocellulosic feedstock with a mixture of an amount of aqueous solution of a dilute acid catalyst and a metal salt catalyst sufficient to provide higher overall fermentable sugar yields than is obtainable when hydrolyzing with dilute acid alone; loading the impregnated lignocellulosic feedstock into a reactor and heating for a sufficient period of time to hydrolyze substantially all of the hemicellulose and greater than 45% of the cellulose to water soluble sugars; and recovering the water soluble sugars.

Stability of purified tuberculin in high dilution

PubMed Central

Magnus, Knut; Guld, Johannes; Waaler, Hans; Magnusson, Mogens

1958-01-01

The authors have investigated the effect of storage on the potency of 5 TU dilutions (5 TU per 0.1 ml) of the purified tuberculin RT 19-21 (Statens Seruminstitut, Copenhagen). Dilutions stored at 2-4°C, 20°C and 37°C for different periods up to 18 months were compared by intradermal testing. About 900 BCG-vaccinated schoolchildren were given duplicate tests and in addition 500 tests were made in BCG-vaccinated guinea-pigs. The results showed unexpected variability. It appeared that this variability was due to unsystematic variations in potency both between dilutions prepared at different times and between ampoules of the same dilution. Because of this variability only limited conclusions could be drawn. At 2-4°C the effect of storage seemed to be very slight, the potency of the dilutions being reduced by less than 25% after 18 months. At the higher temperatures, the decrease in activity was more rapid. Nevertheless, the dilutions could be stored at room temperature (20°C) for some months without any practically significant loss of potency. PMID:13618718

Synthesis and formation mechanism of pinnoite in sulfated-type boron concentrated brine by dilution method

NASA Astrophysics Data System (ADS)

Peng, Jiaoyu; Bian, Shaoju; Lin, Feng; Wang, Liping; Dong, Yaping; Li, Wu

2017-10-01

The synthesis of pinnoite (MgB2O(OH)6) in boron-containing brine was established with a novel dilution method. Effects of temperature, precipitation time, boron concentration and mass dilution ratio on the formation of pinnoite were investigated. The products obtained were characterized by X-ray diffraction (XRD), Raman, thermogravimetric and differential scanning calorimeter (TG-DSC), and scanning electron microscopy. The transformation mechanism of pinnoite with different dilution ratios was assumed by studying the crystal growth of pinnoite. The results showed that pinnoite was synthesized above 60 °C in the diluted brine. There were two reaction steps - precipitation of amorphous solid and the formation of pinnoite crystals - during the whole reaction process of pinnoite when the dilution ratio is more than 1.0 at 80 °C. While in the 0.5 diluted brine, only one reaction step of pinnoite crystal formation was observed and its transformation mechanism was discussed based on dissociation of polyborates in brine. Besides, the origin of pinnoite mineral deposited on salt lake bottom was proposed.

Multiple component end-member mixing model of dilution: hydrochemical effects of construction water at Yucca Mountain, Nevada, USA

NASA Astrophysics Data System (ADS)

Lu, Guoping; Sonnenthal, Eric L.; Bodvarsson, Gudmundur S.

2008-12-01

The standard dual-component and two-member linear mixing model is often used to quantify water mixing of different sources. However, it is no longer applicable whenever actual mixture concentrations are not exactly known because of dilution. For example, low-water-content (low-porosity) rock samples are leached for pore-water chemical compositions, which therefore are diluted in the leachates. A multicomponent, two-member mixing model of dilution has been developed to quantify mixing of water sources and multiple chemical components experiencing dilution in leaching. This extended mixing model was used to quantify fracture-matrix interaction in construction-water migration tests along the Exploratory Studies Facility (ESF) tunnel at Yucca Mountain, Nevada, USA. The model effectively recovers the spatial distribution of water and chemical compositions released from the construction water, and provides invaluable data on the matrix fracture interaction. The methodology and formulations described here are applicable to many sorts of mixing-dilution problems, including dilution in petroleum reservoirs, hydrospheres, chemical constituents in rocks and minerals, monitoring of drilling fluids, and leaching, as well as to environmental science studies.

Single polymer dynamics in semi-dilute unentangled and entangled solutions: from molecular conformation to normal stress

NASA Astrophysics Data System (ADS)

Schroeder, Charles

Semi-dilute polymer solutions are encountered in a wide array of applications such as advanced 3D printing technologies. Semi-dilute solutions are characterized by large fluctuations in concentration, such that hydrodynamic interactions, excluded volume interactions, and transient chain entanglements may be important, which greatly complicates analytical modeling and theoretical treatment. Despite recent progress, we still lack a complete molecular-level understanding of polymer dynamics in these systems. In this talk, I will discuss three recent projects in my group to study semi-dilute solutions that focus on single molecule studies of linear and ring polymers and a new method to measure normal stresses in microfluidic devices based on the Stokes trap. In the first effort, we use single polymer techniques to investigate the dynamics of semi-dilute unentangled and semi-dilute entangled DNA solutions in extensional flow, including polymer relaxation from high stretch, transient stretching dynamics in step-strain experiments, and steady-state stretching in flow. In the semi-dilute unentangled regime, our results show a power-law scaling of the longest polymer relaxation time that is consistent with scaling arguments based on the double cross-over regime. Upon increasing concentration, we observe a transition region in dynamics to the entangled regime. We also studied the transient and steady-state stretching dynamics in extensional flow using the Stokes trap, and our results show a decrease in transient polymer stretch and a milder coil-to-stretch transition for semi-dilute polymer solutions compared to dilute solutions, which is interpreted in the context of a critical Weissenberg number Wi at the coil-to-stretch transition. Interestingly, we observe a unique set of polymer conformations in semi-dilute unentangled solutions that are highly suggestive of transient topological entanglements in solutions that are nominally unentangled at equilibrium. Taken together, these results suggest that the transient stretching pathways in semi-dilute solution extensional flows are qualitatively different than for both dilute solutions and for semi-dilute solutions in shear flow. In a second effort, we studied the dynamics of ring polymers in background solutions of semi-dilute linear polymers. Interestingly, we observe strikingly large fluctuations in steady-state polymer extension for ring polymers in flow, which occurs due to the interplay between polymer topology and concentration leading to chain `threading' in flow. In a third effort, we developed a new microfluidic method to measure normal stress and extensional viscosity that can be loosely described as passive yet non-linear microrheology. In particular, we incorporated 3-D particle imaging velocimetry (PIV) with the Stokes trap to study extensional flow-induced particle migration in semi-dilute polymer solutions. Experimental results are analyzed using the framework of a second-order-fluid model, which allows for measurement of normal stress and extensional viscosity in semi-dilute polymer solutions, all of which is a first-of-its-kind demonstration. Microfluidic measurements of extensional viscosity are directly compared to the dripping-onto-substrate or DOS method, and good agreement is generally observed. Overall, our work aims to provide a molecular-level understanding of the role of polymer topology and concentration on bulk rheological properties by using single polymer techniques.

Cloning by limiting dilution: an improved estimate that an interesting culture is monoclonal.

PubMed Central

Staszewski, R.

1984-01-01

An interesting culture obtained by limiting dilution is less likely to be monoclonal than a random viable culture. Current practice using limiting dilution to establish monoclonal lines of interesting recombinant DNA or hybridoma-derived organisms overestimates the probability that promising cultures are monoclonal, resulting in inadequate dilutions, with the need for additional subcloning and the avoidable loss (avoidable instability) of interesting lines by overgrowth with uninteresting varieties. PMID:6537695

Total body water and lean body mass estimated by ethanol dilution

NASA Technical Reports Server (NTRS)

Loeppky, J. A.; Myhre, L. G.; Venters, M. D.; Luft, U. C.

1977-01-01

A method for estimating total body water (TBW) using breath analyses of blood ethanol content is described. Regression analysis of ethanol concentration curves permits determination of a theoretical concentration that would have existed if complete equilibration had taken place immediately upon ingestion of the ethanol; the water fraction of normal blood may then be used to calculate TBW. The ethanol dilution method is applied to 35 subjects, and comparison with a tritium dilution method of determining TBW indicates that the correlation between the two procedures is highly significant. Lean body mass and fat fraction were determined by hydrostatic weighing, and these data also prove compatible with results obtained from the ethanol dilution method. In contrast to the radioactive tritium dilution method, the ethanol dilution method can be repeated daily with its applicability ranging from diseased individuals to individuals subjected to thermal stress, strenuous exercise, water immersion, or the weightless conditions of space flights.

Videodensitometric Methods for Cardiac Output Measurements

NASA Astrophysics Data System (ADS)

Mischi, Massimo; Kalker, Ton; Korsten, Erik

2003-12-01

Cardiac output is often measured by indicator dilution techniques, usually based on dye or cold saline injections. Developments of more stable ultrasound contrast agents (UCA) are leading to new noninvasive indicator dilution methods. However, several problems concerning the interpretation of dilution curves as detected by ultrasound transducers have arisen. This paper presents a method for blood flow measurements based on UCA dilution. Dilution curves are determined by real-time densitometric analysis of the video output of an ultrasound scanner and are automatically fitted by the Local Density Random Walk model. A new fitting algorithm based on multiple linear regression is developed. Calibration, that is, the relation between videodensity and UCA concentration, is modelled by in vitro experimentation. The flow measurement system is validated by in vitro perfusion of SonoVue contrast agent. The results show an accurate dilution curve fit and flow estimation with determination coefficient larger than 0.95 and 0.99, respectively.

Functional consortium for denitrifying sulfide removal process.

PubMed

Chen, Chuan; Ren, Nanqi; Wang, Aijie; Liu, Lihong; Lee, Duu-Jong

2010-03-01

Denitrifying sulfide removal (DSR) process simultaneously converts sulfide, nitrate, and chemical oxygen demand from industrial wastewaters to elemental sulfur, nitrogen gas, and carbon dioxide, respectively. This investigation utilizes a dilution-to-extinction approach at 10(-2) to 10(-6) dilutions to elucidate the correlation between the composition of the microbial community and the DSR performance. In the original suspension and in 10(-2) dilution, the strains Stenotrophomonas sp., Thauera sp., and Azoarcus sp. are the heterotrophic denitrifiers and the strains Paracoccus sp. and Pseudomonas sp. are the sulfide-oxidizing denitrifers. The 10(-4) dilution is identified as the functional consortium for the present DSR system, which comprises two functional strains, Stenotrophomonas sp. strain Paracoccus sp. At 10(-6) dilution, all DSR performance was lost. The functions of the constituent cells in the DSR granules were discussed based on data obtained using the dilution-to-extinction approach.

Color-dilution alopecia in dogs.

PubMed

Kim, Jae Hoon; Kang, Kyung Il; Sohn, Hyun Joo; Woo, Gye Hyeong; Jean, Young Hwa; Hwang, Eui Kyung

2005-09-01

Color-dilution alopecia is a relatively uncommon hereditary skin disease seen in "Blue" and other color-diluted dogs. This syndrome is associated with a color-dilution gene. The initial clinical signs are the gradual onset of a dry, dull and poor hair coat quality. Hair shafts and hair regrowth are poor, and follicular papules may develop and progress to frank comedones. Hair loss and comedo formation are usually most severe on the trunk, especially color-diluted area on the skin. Six cases of color-dilution alopecia are reported in 3 months to 10 years old dogs. The breeds of dogs are blue Doberman Pinscher, Miniature Pinscher, Dachshund, and Schnauzer. Grossly, extensive partial hair loss was seen on the skin. Histopathologically, the epidermis is relatively normal but may be hyperplastic. Hair follicles are characterized by atrophy and distortion. Heavily clumped melanin is present in the epidermis, dermis and hair follicles.

A roadmap to defining the clinical reportable ranges of chemistry analytes: Increasing automation efficiency and decreasing manual dilutions.

PubMed

Lo, Sheng-Ying; Baird, Geoffrey S; Greene, Dina N

2015-12-07

Proper utilization of resources is an important operational objective for clinical laboratories. To reduce unnecessary manual interventions on automated instruments, we conducted a workflow analysis that optimized dilution parameters and reporting of abnormally high chemistry results for the Beckman AU series of chemistry analyzers while maintaining clinically acceptable reportable ranges. Workflow analysis for the Beckman AU680/5812 and DxC800 chemistry analyzers was performed using historical data. Clinical reportable ranges for 53 chemistry analytes were evaluated. Optimized dilution parameters and upper limit of reportable ranges for the AU680/5812 instruments were derived and validated to meet these reportable ranges. The number of specimens that required manual dilutions before and after optimization was determined for both the AU680/5812 and DxC800, with the DxC800 serving as the reference instrument. Retrospective data analysis revealed that 7700 specimens required manual dilutions on the DxC over a 2-y period. Using our optimized AU-specific dilution and reporting parameters, the data-driven simulation analysis showed a 61% reduction in manual dilutions. For the specimens that required manual dilutions on the AU680/5812, we developed standardized dilution procedures to further streamline workflow. We provide a data-driven, practical outline for clinical laboratories to efficiently optimize their use of automated chemistry analyzers. The outcomes can be used to assist laboratories wishing to improve their existing procedures or to facilitate transitioning into a new line of instrumentation, regardless of the instrument model or manufacturer. Copyright © 2015 Elsevier B.V. All rights reserved.

Dilution testing using rapid diagnostic tests in a HIV diagnostic algorithm: a novel alternative for confirmation testing in resource limited settings.

PubMed

Shanks, Leslie; Siddiqui, M Ruby; Abebe, Almaz; Piriou, Erwan; Pearce, Neil; Ariti, Cono; Masiga, Johnson; Muluneh, Libsework; Wazome, Joseph; Ritmeijer, Koert; Klarkowski, Derryck

2015-05-14

Current WHO testing guidelines for resource limited settings diagnose HIV on the basis of screening tests without a confirmation test due to cost constraints. This leads to a potential risk of false positive HIV diagnosis. In this paper, we evaluate the dilution test, a novel method for confirmation testing, which is simple, rapid, and low cost. The principle of the dilution test is to alter the sensitivity of a rapid diagnostic test (RDT) by dilution of the sample, in order to screen out the cross reacting antibodies responsible for falsely positive RDT results. Participants were recruited from two testing centres in Ethiopia where a tiebreaker algorithm using 3 different RDTs in series is used to diagnose HIV. All samples positive on the initial screening RDT and every 10th negative sample underwent testing with the gold standard and dilution test. Dilution testing was performed using Determine™ rapid diagnostic test at 6 different dilutions. Results were compared to the gold standard of Western Blot; where Western Blot was indeterminate, PCR testing determined the final result. 2895 samples were recruited to the study. 247 were positive for a prevalence of 8.5 % (247/2895). A total of 495 samples underwent dilution testing. The RDT diagnostic algorithm misclassified 18 samples as positive. Dilution at the level of 1/160 was able to correctly identify all these 18 false positives, but at a cost of a single false negative result (sensitivity 99.6 %, 95 % CI 97.8-100; specificity 100 %, 95 % CI: 98.5-100). Concordance between the gold standard and the 1/160 dilution strength was 99.8 %. This study provides proof of concept for a new, low cost method of confirming HIV diagnosis in resource-limited settings. It has potential for use as a supplementary test in a confirmatory algorithm, whereby double positive RDT results undergo dilution testing, with positive results confirming HIV infection. Negative results require nucleic acid testing to rule out false negative results due to seroconversion or misclassification by the lower sensitivity dilution test. Further research is needed to determine if these results can be replicated in other settings. ClinicalTrials.gov, NCT01716299 .

Use of wind data for estimating horizontal dilution potential of atmosphere.

PubMed

George, K V; Verma, P; Devotta, S

2007-04-01

In this study, a new methodology is suggested for estimating horizontal dilution potential of an area using wind data. The mean wind speed and wind direction variation are used as a measure of linear and angular spread of pollutants in the atmosphere. A formula is developed for estimating the potential of horizontal spread of pollutants in an area wherein only the wind speed and direction are used. The methodology is further applied to monitor wind data of one year. It is found that there is a very smooth variation of horizontal dilution potential over a year with limited dilution during post monsoon period and a high dilution in pre monsoon period.

Dynamics of atmospheres with a non-dilute condensible component

PubMed Central

Ding, Feng

2016-01-01

The diversity of characteristics for the host of recently discovered exoplanets opens up a great deal of fertile new territory for geophysical fluid dynamics, particularly when the fluid flow is coupled to novel thermodynamics, radiative transfer or chemistry. In this paper, we survey one of these new areas—the climate dynamics of atmospheres with a non-dilute condensible component, defined as the situation in which a condensible component of the atmosphere makes up a substantial fraction of the atmospheric mass within some layer. Non-dilute dynamics can occur for a wide range of condensibles, generically applying near both the inner and the outer edges of the conventional habitable zone and in connection with runaway greenhouse phenomena. It also applies in a wide variety of other planetary circumstances. We first present a number of analytical results developing some key features of non-dilute atmospheres, and then show how some of these features are manifest in simulations with a general circulation model adapted to handle non-dilute atmospheres. We find that non-dilute atmospheres have weak horizontal temperature gradients even for rapidly rotating planets, and that their circulations are largely barotropic. The relative humidity of the condensible component tends towards 100% as the atmosphere becomes more non-dilute, which has important implications for runaway greenhouse thresholds. Non-dilute atmospheres exhibit a number of interesting organized convection features, for which there is not yet any adequate theoretical understanding. PMID:27436980

Bio-derived Fuel Blend Dilution of Marine Engine Oil and Imapct on Friction and Wear Behavior

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

Ajayi, Oyelayo O.; Lorenzo-Martin, Cinta; Fenske, George R.

To reduce the amount of petroleum-derived fuel used in vehicles and vessels powered by internal combustion engines, the addition of bio-derived fuel extenders is a common practice. Ethanol is perhaps the most common bio-derived fuel used for blending, and butanol is being evaluated as a promising alternative. The present study determined the fuel dilution rate of three lubricating oils (E0, E10, and i-B16) in a marine engine operating in on-water conditions with a start-and-stop cycle protocol. The level of fuel dilution increased with the number of cycles for all three fuels. The most dilution was observed with i-B16 fuel, andmore » the least with E10 fuel. In all cases, fuel dilution substantially reduced the oil viscosity. The impacts of fuel dilution and the consequent viscosity reduction on the lubricating capability of the engine oil in terms of friction, wear, and scuffing prevention were evaluated by four different tests protocols. Although the fuel dilution of the engine oil had minimal effect on friction, because the test conditions were under the boundary lubrication regime, significant effects were observed on wear in many cases. Fuel dilution also was observed to reduce the load-carrying capacity of the engine oils in terms of scuffing load reduction.« less

Dynamics of atmospheres with a non-dilute condensible component.

PubMed

Pierrehumbert, Raymond T; Ding, Feng

2016-06-01

The diversity of characteristics for the host of recently discovered exoplanets opens up a great deal of fertile new territory for geophysical fluid dynamics, particularly when the fluid flow is coupled to novel thermodynamics, radiative transfer or chemistry. In this paper, we survey one of these new areas-the climate dynamics of atmospheres with a non-dilute condensible component, defined as the situation in which a condensible component of the atmosphere makes up a substantial fraction of the atmospheric mass within some layer. Non-dilute dynamics can occur for a wide range of condensibles, generically applying near both the inner and the outer edges of the conventional habitable zone and in connection with runaway greenhouse phenomena. It also applies in a wide variety of other planetary circumstances. We first present a number of analytical results developing some key features of non-dilute atmospheres, and then show how some of these features are manifest in simulations with a general circulation model adapted to handle non-dilute atmospheres. We find that non-dilute atmospheres have weak horizontal temperature gradients even for rapidly rotating planets, and that their circulations are largely barotropic. The relative humidity of the condensible component tends towards 100% as the atmosphere becomes more non-dilute, which has important implications for runaway greenhouse thresholds. Non-dilute atmospheres exhibit a number of interesting organized convection features, for which there is not yet any adequate theoretical understanding.

In vitro effects of 3% hypertonic saline and 20% mannitol on canine whole blood coagulation and platelet function.

PubMed

Adamik, Katja-Nicole; Butty, Emmanuelle; Howard, Judith

2015-09-24

Hyperosmolar therapy, using either mannitol or hypertonic saline (HTS), is considered the treatment of choice for intracranial hypertension. However, hyperosmolar agents may impair coagulation and platelet function, limiting their use in patients at risk for hemorrhage. Despite this, studies evaluating the effects of mannitol compared to other hyperosmolar agents in dogs are largely lacking. The aim of this study was to compare the in vitro effects on global hemostasis and platelet function of 20% mannitol and 3% HTS on canine blood. Citrated whole blood from 15 healthy dogs was diluted with 0.9% saline, 20% mannitol and 3% HTS in ratios of 1:16 and 1:8. Rotational thromboelastometry (ROTEM) was used to assess clotting time (CT), clot formation time (CFT) and maximal clot firmness (MCF) following extrinsic activation (Ex-tem) and after platelet inhibition (Fib-tem). A platelet function analyzer (PFA-100) was used to assess closure time (Ct(PFA)). No significant differences were observed between untreated whole blood and samples diluted with saline. Samples diluted with both mannitol and HTS were hypocoagulable compared to untreated whole blood samples. At a dilution of 1:16, no significant differences were found between any measured parameter in samples diluted with saline compared to mannitol or HTS. At a 1:8 dilution, Ct(PFA) was prolonged in samples diluted with mannitol and HTS compared to saline, and Ct(PFA) was prolonged more with mannitol than HTS. Ex-tem CT was increased at a 1:8 dilution with mannitol compared to HTS. Ex-tem CFT was prolonged at a 1:8 dilution with both agents compared to saline, and was prolonged more with mannitol than HTS. Ex-tem MCF was reduced at a 1:8 dilution with both agents compared to saline. Data in this study indicate that both mannitol and HTS affect canine platelet function and whole blood coagulation in vitro in a dose-dependent fashion. The most pronounced effects were observed after high dilutions with mannitol, which impaired platelet aggregation, clot formation time, clot strength, and fibrin formation significantly more than HTS. Further in vivo studies are necessary before recommendations can be made.

Dilution of boar ejaculates with BTS containing HEPES in place of bicarbonate immediately after ejaculation can reduce the increased inducibility of the acrosome reaction by treatment with calcium and calcium ionophore A23187, which is potentially associated with boar subfertility.

PubMed

Murase, Tetsuma; Imaeda, Noriaki; Yamada, Hiroto; Takasu, Masaki; Taguchi, Kazuo; Katoh, Tsutomu

2010-06-01

The present study investigated whether substitution of HEPES for bicarbonate in BTS (BTS-H) used to dilute boar ejaculates immediately after ejaculation could reduce the increased inducibility of the acrosome reaction by calcium and calcium ionophore A23187. When an ejaculate was split, diluted 5-fold with regular BTS (BTS-B) and BTS-H and stored at 17 C for 12 h or 60 h, the extender or storage time had no significant influence on sperm motility or viability measured by the eosin-nigrosin method. When spermatozoa diluted serially with BTS-B and stored (36 h) were stimulated with Ca2+ (3 mM) and A23187 (0.3 microM), the proportion of spermatozoa that underwent the acrosome reaction (% acrosome reactions) significantly increased as the magnifications of dilution increased (bicarbonate content almost unchanged by dilution). By contrast, the % acrosome reactions in spermatozoa similarly diluted and stored with BTS-H decreased with the increasing magnifications of dilution (bicarbonate decreased). Sperm motility immediately after the end of incubation without A23178 tended to be lower for BTS-H than BTS-B, and the ejaculates for BTS-H had a tendency to have a lower total protein in seminal plasma than those for BTS-B. These results implied that the samples for BTS-H could be used as a model for ejaculates possibly collected during summer and showing subfertility. When an ejaculate was split, diluted serially with BTS-B and BTS-H and stored, viability measured by staining with propidium iodide was extremely similar between the 2 extenders and among the different dilution magnifications, regardless of whether spermatozoa were washed (stored for 36-66 h) or not (stored for 66-72 h). These results suggest that boar ejaculate can be stored with BTS-H at least according to the results for sperm motility and viability and that hypersensitivity of spermatozoa to Ca2+ and A23187 potentially associated with boar subfertility could be lessened by diluting ejaculates with BTS-H.

Nanosized solvent superstructures in ultramolecular aqueous dilutions: twenty years' research using water proton NMR relaxation.

PubMed

Demangeat, Jean-Louis

2013-04-01

proton nuclear magnetic resonance (NMR) relaxation times T1, T2, T1/T2 are sensitive to motion and organization of water molecules. Especially, increase in T1/T2 reflects a higher degree of structuring. My purpose was to look at physical changes in water in ultrahigh aqueous dilutions. Samples were prepared by iterative centesimal (c) dilution with vigorous agitation, ranging between 3c and 24c (Avogadro limit 12c). Solutes were silica-lactose, histamine, manganese-lactose. Solvents were water, NaCl 0.15 M or LiCl 0.15 M. Solvents underwent strictly similar, simultaneous dilution/agitation, for each level of dilution, as controls. NMR relaxation was studied within 0.02-20 MHz. No changes were observed in controls. Increasing T1 and T1/T2 were found in dilutions, which persisted beyond 9c (manganese-lactose), 10c (histamine) and 12c (silica-lactose). For silica-lactose in LiCl, continuous decrease in T2 with increase in T1/T2 within the 12c-24c range indicated growing structuring of water despite absence of the initial solute. All changes vanished after heating/cooling. These findings were interpreted in terms of nanosized (>4-nm) supramolecular structures involving water, nanobubbles and ions, if any. Additional study of low dilutions of silica-lactose revealed increased T2 and decreased T1/T2 compared to solvent, within the 10(-3)-10(-6) range, reflecting transient solvent destructuring. This could explain findings at high dilution. Proton NMR relaxation demonstrated modifications of the solvent throughout the low to ultramolecular range of dilution. The findings suggested the existence of superstructures that originate stereospecifically around the solute after an initial destructuring of the solvent, developing more upon dilution and persisting beyond 12c. Copyright © 2013 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Linking manipulative experiments to field data to test the dilution effect.

PubMed

Venesky, Matthew D; Liu, Xuan; Sauer, Erin L; Rohr, Jason R

2014-05-01

The dilution effect, the hypothesis that biodiversity reduces disease risk, has received support in many systems. However, few dilution effect studies have linked mechanistic experiments to field patterns to establish both causality and ecological relevance. We conducted a series of laboratory experiments and tested the dilution effect hypothesis in an amphibian-Batrachochytrium dendrobatidis (Bd) system and tested for consistency between our laboratory experiments and field patterns of amphibian species richness, host identity and Bd prevalence. In our laboratory experiments, we show that tadpoles can filter feed Bd zoospores and that the degree of suspension feeding was positively associated with their dilution potential. The obligate suspension feeder, Gastrophryne carolinensis, generally diluted the risk of chytridiomycosis for tadpoles of Bufo terrestris and Hyla cinerea, whereas tadpoles of B. terrestris (an obligate benthos feeder) generally amplified infections for the other species. In addition, G. carolinensis reduced Bd abundance on H. cinerea more so in the presence than absence of B. terrestris and B. terrestris amplified Bd abundance on H. cinerea more so in the absence than presence of G. carolinensis. Also, when ignoring species identity, species richness was a significant negative predictor of Bd abundance. In our analysis of field data, the presence of Bufo spp. and Gastrophryne spp. were significant positive and negative predictors of Bd prevalence, respectively, even after controlling for climate, vegetation, anthropogenic factors (human footprint), species richness and sampling effort. These patterns of dilution and amplification supported our laboratory findings, demonstrating that the results are likely ecologically relevant. The results from our laboratory and field data support the dilution effect hypothesis and also suggest that dilution and amplification are predictable based on host traits. Our study is among the first to link manipulative experiments, in which a potential dilution mechanism is supported, with analyses of field data on species richness, host identity, spatial autocorrelation and disease prevalence. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Disentangling niche competition from grazing mortality in phytoplankton dilution experiments

PubMed Central

Weitz, Joshua S.

2017-01-01

The dilution method is the principal tool used to infer in situ microzooplankton grazing rates. However, grazing is the only mortality process considered in the theoretical model underlying the interpretation of dilution method experiments. Here we evaluate the robustness of mortality estimates inferred from dilution experiments when there is concurrent niche competition amongst phytoplankton. Using a combination of mathematical analysis and numerical simulations, we find that grazing rates may be overestimated—the degree of overestimation is related to the importance of niche competition relative to microzooplankton grazing. In response, we propose a conceptual method to disentangle the effects of niche competition and grazing by diluting out microzooplankton, but not phytoplankton. Our theoretical results suggest this revised “Z-dilution” method can robustly infer grazing mortality, regardless of the dominant phytoplankton mortality driver in our system. Further, we show it is possible to independently estimate both grazing mortality and niche competition if the classical and Z-dilution methods can be used in tandem. We discuss the significance of these results for quantifying phytoplankton mortality rates; and the feasibility of implementing the Z-dilution method in practice, whether in model systems or in complex communities with overlap in the size distributions of phytoplankton and microzooplankton. PMID:28505212

Approaches of aroma extraction dilution analysis (AEDA) for headspace solid phase microextraction and gas chromatography-olfactometry (HS-SPME-GC-O): Altering sample amount, diluting the sample or adjusting split ratio?

PubMed

Feng, Yunzi; Cai, Yu; Sun-Waterhouse, Dongxiao; Cui, Chun; Su, Guowan; Lin, Lianzhu; Zhao, Mouming

2015-11-15

Aroma extract dilution analysis (AEDA) is widely used for the screening of aroma-active compounds in gas chromatography-olfactometry (GC-O). In this study, three aroma dilution methods, (I) using different test sample volumes, (II) diluting samples, and (III) adjusting the GC injector split ratio, were compared for the analysis of volatiles by using HS-SPME-AEDA. Results showed that adjusting the GC injector split ratio (III) was the most desirable approach, based on the linearity relationships between Ln (normalised peak area) and Ln (normalised flavour dilution factors). Thereafter this dilution method was applied in the analysis of aroma-active compounds in Japanese soy sauce and 36 key odorants were found in this study. The most intense aroma-active components in Japanese soy sauce were: ethyl 2-methylpropanoate, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, ethyl 4-methylpentanoate, 3-(methylthio)propanal, 1-octen-3-ol, 2-methoxyphenol, 4-ethyl-2-methoxyphenol, 2-methoxy-4-vinylphenol, 2-phenylethanol, and 4-hydroxy-5-ethyl-2-methyl-3(2H)-furanone. Copyright © 2015. Published by Elsevier Ltd.

Polymer relaxation and stretching dynamics in semi-dilute DNA solutions: a single molecule study

NASA Astrophysics Data System (ADS)

Hsiao, Kai-Wen; Brockman, Christopher; Schroeder, Charles

2015-03-01

In this work, we study polymer relaxation and stretching dynamics in semi-dilute DNA solutions using single molecule techniques. Using this approach, we uncover a unique scaling relation for longest polymer relaxation time that falls in the crossover regime described by semi-flexible polymer solutions, which is distinct from truly flexible polymer chains. In addition, we performed a series of step-strain experiments on single polymers in semi-dilute solutions in planar extensional flow using an automated microfluidic trap. In this way, we are able to precisely control the flow strength and the amount of strain applied to single polymer chains, thereby enabling direct observation of the full stretching and relaxation process in semi-dilute solutions during transient start-up and flow cessation. Interestingly, we observe polymer individualism in the conformation of single chains in semi-dilute solutions, which to our knowledge has not yet been observed. In addition, we observe the relaxation data can be explained by a multi-exponential decay process after flow cessation in semi-dilute solutions. Overall, our work reports key advance in non-dilute polymer systems from a molecular perspective via direct observation of dynamics in strong flows. DOW fellowship.

The mathematics of dilution.

PubMed

Chatterjee, Barun Kumar

2014-04-01

The major objection to homeopathic medicine is that the doses of medicine prescribed in some cases are too dilute for any active ingredient to be present. The medicines would hence be rendered inactive, necessitating novel explanations for the action. A further examination of dilution in the light of the Langmuir equation shows that homeopathic medicines may not be as dilute as a simplistic application of Avogadro's Principle suggests, due to surface effects. Copyright © 2013 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Experimental study of the effects of secondary air on the emissions and stability of a lean premixed combustor

NASA Technical Reports Server (NTRS)

Roffe, G.; Raman, R. S. V.; Marek, C. J.

1982-01-01

A study of the effects of secondary air addition on the stability and emissions of a gas turbine combustor has been performed. Tests were conducted with two types of flameholders and varying amounts of dilution air addition. Results indicate that NO(x) decreases with increasing dilution air injection, whereas CO is independent of the amount of dilution air and is related to the gas temperature near the walls. The axial location of the dilution air addition has no effect on the performance or stability. Results also indicate that the amount of secondary air entrained by the flameholder recirculation zone is dependent on the amount of dilution air and flameholder geometry.

Number of siblings and intellectual development. The resource dilution explanation.

PubMed

Downey, D B

2001-01-01

The resource dilution model posits that parental resources are finite and that as the number of children in the family increases, the resources accrued by any one child necessarily decline. Siblings are competitors for parents' time, energy, and financial resources and so the fewer the better. Even one sibling is too many. The author describes the general elements of the dilution position and assesses its merits for explaining the effect of siblings on one component of the educational process--tests of intellectual development. The author identifies critical flaws in recent critiques of the dilution position and concludes that dilution continues to provide the most promising explanation for why children with few siblings score higher on tests of cognitive skills than children with many siblings.

40 CFR 1065.667 - Dilution air background emission correction.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.667 Dilution air background emission correction. (a) To determine the mass of background emissions to subtract... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Dilution air background emission...

40 CFR 1065.667 - Dilution air background emission correction.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.667 Dilution air background emission correction. (a) To determine the mass of background emissions to subtract... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Dilution air background emission...

40 CFR 1065.667 - Dilution air background emission correction.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.667 Dilution air background emission correction. (a) To determine the mass of background emissions to subtract... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Dilution air background emission...

40 CFR 1065.667 - Dilution air background emission correction.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.667 Dilution air background emission correction. (a) To determine the mass of background emissions to subtract... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Dilution air background emission...

40 CFR 1065.667 - Dilution air background emission correction.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.667 Dilution air background emission correction. (a) To determine the mass of background emissions to subtract... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Dilution air background emission...

Microfluidic Serial Dilution Circuit

PubMed Central

Paegel, Brian M.; Grover, William H.; Skelley, Alison M.; Mathies, Richard A.; Joyce, Gerald F.

2008-01-01

In vitro evolution of RNA molecules requires a method for executing many consecutive serial dilutions. To solve this problem, a microfluidic circuit has been fabricated in a three-layer glass-PDMS-glass device. The 400-nL serial dilution circuit contains five integrated membrane valves: three two-way valves arranged in a loop to drive cyclic mixing of the diluent and carryover, and two bus valves to control fluidic access to the circuit through input and output channels. By varying the valve placement in the circuit, carryover fractions from 0.04 to 0.2 were obtained. Each dilution process, which is comprised of a diluent flush cycle followed by a mixing cycle, is carried out with no pipeting, and a sample volume of 400 nL is sufficient for conducting an arbitrary number of serial dilutions. Mixing is precisely controlled by changing the cyclic pumping rate, with a minimum mixing time of 22 s. This microfluidic circuit is generally applicable for integrating automated serial dilution and sample preparation in almost any microfluidic architecture. PMID:17073422

Deep freezing of Angora goat semen: effects of diluent composition and method and rate of dilution on survival of spermatozoa.

PubMed

Salamon, S; Ritar, A J

1982-01-01

Five factorial experiments were conducted to examine the effects of concentration of tris(hydroxymethyl)aminomethane (Tris), type and concentration of sugar in the diluent, rate and method of dilution on the survival of goat spermatozoa after freezing by the pellet method. Spermatozoa tolerated a relatively wide range in concentration of Tris, but the cell survival depended on the type of sugar included in the Tris diluent. Glucose and fructose were more suitable components than lactose or raffinose. Survival of spermatozoa after thawing was better for three- to fivefold prefreezing dilution. There was interaction between method of semen dilution (one-step, two-step), holding time at 5 degrees C, and glycerol concentration. The best result was obtained after one-step dilution at 30 degrees C (Tris 375 mM-glucose 41.625 mM-citric acid 124 mM), 1.5 h holding at 5 degrees C, and with 4% (v/v) glycerol concentration in the diluted semen.

Use of Empty Fruit Bunches from the oil palm for bioethanol production: a thorough comparison between dilute acid and dilute alkali pretreatment.

PubMed

Chiesa, S; Gnansounou, E

2014-05-01

In the present work, two pretreatment techniques using either dilute acid (H2SO4) or dilute alkali (NaOH) have been compared for producing bioethanol from Empty Fruit Bunches (EFBs) from oil palm tree, a relevant feedstock for tropical countries. Treatments' performances under different conditions have been assessed and statistically optimized with respect to the response upon standardized enzymatic saccharification. The dilute acid treatment performed at optimal conditions (161.5°C, 9.44 min and 1.51% acid loading) gave 85.5% glucose yield, comparable to those of other commonly investigated feedstocks. Besides, the possibility of using fibers instead of finely ground biomass may be of economic interest. Oppositely, treatment with dilute alkali has shown lower performances under the conditions explored, most likely given the relatively significant lignin content, suggesting that the use of stronger alkali regime (with the associated drawbacks) is unavoidable to improve the performance of this treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of very low doses of mediators on fungal laccase activity - nonlinearity beyond imagination

PubMed Central

Malarczyk, Elzbieta; Kochmanska-Rdest, Janina; Jarosz-Wilkolazka, Anna

2009-01-01

Laccase, an enzyme responsible for aerobic transformations of natural phenolics, in industrial applications requires the presence of low-molecular substances known as mediators, which accelerate oxidation processes. However, the use of mediators is limited by their toxicity and the high costs of exploitation. The activation of extracellular laccase in growing fungal culture with highly diluted mediators, ABTS and HBT is described. Two high laccase-producing fungal strains, Trametes versicolor and Cerrena unicolor, were used in this study as a source of enzyme. Selected dilutions of the mediators significantly increased the activity of extracellular laccase during 14 days of cultivation what was distinctly visible in PAGE technique and in colorimetric tests. The same mediator dilutions increased demethylation properties of laccase, which was demonstrated during incubation of enzyme with veratric acid. It was established that the activation effect was assigned to specific dilutions of mediators. Our dose-response dilution process smoothly passes into the range of action of homeopathic dilutions and is of interest for homeopaths. PMID:19732425

Conversion of depleted uranium hexafluoride to a solid uranium compound

DOEpatents

Rothman, Alan B.; Graczyk, Donald G.; Essling, Alice M.; Horwitz, E. Philip

2001-01-01

A process for converting UF.sub.6 to a solid uranium compound such as UO.sub.2 and CaF. The UF.sub.6 vapor form is contacted with an aqueous solution of NH.sub.4 OH at a pH greater than 7 to precipitate at least some solid uranium values as a solid leaving an aqueous solution containing NH.sub.4 OH and NH.sub.4 F and remaining uranium values. The solid uranium values are separated from the aqueous solution of NH.sub.4 OH and NH.sub.4 F and remaining uranium values which is then diluted with additional water precipitating more uranium values as a solid leaving trace quantities of uranium in a dilute aqueous solution. The dilute aqueous solution is contacted with an ion-exchange resin to remove substantially all the uranium values from the dilute aqueous solution. The dilute solution being contacted with Ca(OH).sub.2 to precipitate CaF.sub.2 leaving dilute NH.sub.4 OH.

Worldwide estimation of river concentrations of any chemical originating from sewage-treatment plants using dilution factors.

PubMed

Keller, Virginie D J; Williams, Richard J; Lofthouse, Caryn; Johnson, Andrew C

2014-02-01

Dilution factors are a critical component in estimating concentrations of so-called "down-the-drain" chemicals (e.g., pharmaceuticals) in rivers. The present study estimated the temporal and spatial variability of dilution factors around the world using geographically referenced data sets at 0.5° × 0.5° resolution. Domestic wastewater effluents were derived from national per capita domestic water use estimates and gridded population. Monthly and annual river flows were estimated by accumulating runoff estimates using topographically derived flow directions. National statistics, including the median and interquartile range, were generated to quantify dilution factors. Spatial variability of the dilution factor was found to be considerable; for example, there are 4 orders of magnitude in annual median dilution factor between Canada and Morocco. Temporal variability within a country can also be substantial; in India, there are up to 9 orders of magnitude between median monthly dilution factors. These national statistics provide a global picture of the temporal and spatial variability of dilution factors and, hence, of the potential exposure to down-the-drain chemicals. The present methodology has potential for a wide international community (including decision makers and pharmaceutical companies) to assess relative exposure to down-the-drain chemicals released by human pollution in rivers and, thus, target areas of potentially high risk. © 2013 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Biodiversity inhibits parasites: Broad evidence for the dilution effect.

PubMed

Civitello, David J; Cohen, Jeremy; Fatima, Hiba; Halstead, Neal T; Liriano, Josue; McMahon, Taegan A; Ortega, C Nicole; Sauer, Erin Louise; Sehgal, Tanya; Young, Suzanne; Rohr, Jason R

2015-07-14

Infectious diseases of humans, wildlife, and domesticated species are increasing worldwide, driving the need to understand the mechanisms that shape outbreaks. Simultaneously, human activities are drastically reducing biodiversity. These concurrent patterns have prompted repeated suggestions that biodiversity and disease are linked. For example, the dilution effect hypothesis posits that these patterns are causally related; diverse host communities inhibit the spread of parasites via several mechanisms, such as by regulating populations of susceptible hosts or interfering with parasite transmission. However, the generality of the dilution effect hypothesis remains controversial, especially for zoonotic diseases of humans. Here we provide broad evidence that host diversity inhibits parasite abundance using a meta-analysis of 202 effect sizes on 61 parasite species. The magnitude of these effects was independent of host density, study design, and type and specialization of parasites, indicating that dilution was robust across all ecological contexts examined. However, the magnitude of dilution was more closely related to the frequency, rather than density, of focal host species. Importantly, observational studies overwhelmingly documented dilution effects, and there was also significant evidence for dilution effects of zoonotic parasites of humans. Thus, dilution effects occur commonly in nature, and they may modulate human disease risk. A second analysis identified similar effects of diversity in plant-herbivore systems. Thus, although there can be exceptions, our results indicate that biodiversity generally decreases parasitism and herbivory. Consequently, anthropogenic declines in biodiversity could increase human and wildlife diseases and decrease crop and forest production.

40 CFR 89.424 - Dilute emission sampling calculations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Dilute emission sampling calculations... Emission Test Procedures § 89.424 Dilute emission sampling calculations. (a) The final reported emission... concentration. For cases where exhaust sampling of CO2 is not performed, the following approximation is...

40 CFR 89.424 - Dilute emission sampling calculations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Dilute emission sampling calculations... Emission Test Procedures § 89.424 Dilute emission sampling calculations. (a) The final reported emission... concentration. For cases where exhaust sampling of CO2 is not performed, the following approximation is...

21 CFR 862.2750 - Pipetting and diluting system for clinical use.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pipetting and diluting system for clinical use... SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2750 Pipetting and diluting system for clinical use. (a) Identification. A pipetting and...

40 CFR 797.1400 - Fish acute toxicity test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... construction materials, test chambers, and testing apparatus to dilution water or to test solutions prior to... or the leaching of substances from the test facilities into the dilution water or test solution. (5... intermittent passage of test solution or dilution water through a test chamber, or a holding or acclimation...

21 CFR 172.710 - Adjuvants for pesticide use dilutions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Adjuvants for pesticide use dilutions. 172.710 Section 172.710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... HUMAN CONSUMPTION Other Specific Usage Additives § 172.710 Adjuvants for pesticide use dilutions. The...

21 CFR 172.710 - Adjuvants for pesticide use dilutions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Adjuvants for pesticide use dilutions. 172.710 Section 172.710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... HUMAN CONSUMPTION Other Specific Usage Additives § 172.710 Adjuvants for pesticide use dilutions. The...

30 CFR 36.49 - Tests of exhaust-gas dilution system.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests of exhaust-gas dilution system. 36.49..., EVALUATION, AND APPROVAL OF MINING PRODUCTS APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT Test Requirements § 36.49 Tests of exhaust-gas dilution system. The performance and...

30 CFR 36.49 - Tests of exhaust-gas dilution system.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Tests of exhaust-gas dilution system. 36.49..., EVALUATION, AND APPROVAL OF MINING PRODUCTS APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT Test Requirements § 36.49 Tests of exhaust-gas dilution system. The performance and...

40 CFR 156.146 - Residue removal instructions for nonrefillable containers-rigid containers with dilutable...

Code of Federal Regulations, 2010 CFR

2010-07-01

... product packaged in a rigid nonrefillable container must include the following residue removal... dilutable pesticide product packaged in rigid nonrefillable containers must include one of the following sets of instructions. (1) For liquid dilutable pesticide products in containers small enough to shake...

40 CFR 268.3 - Dilution prohibited as a substitute for treatment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS General § 268.3 Dilution prohibited as a... circumvent a land disposal prohibition imposed by RCRA section 3004. (b) Dilution of wastes that are... hazardous wastes in order to achieve any land disposal restriction treatment standard for lead. Lead...

40 CFR 268.3 - Dilution prohibited as a substitute for treatment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS General § 268.3 Dilution prohibited as a... circumvent a land disposal prohibition imposed by RCRA section 3004. (b) Dilution of wastes that are... hazardous wastes in order to achieve any land disposal restriction treatment standard for lead. Lead...

40 CFR 268.3 - Dilution prohibited as a substitute for treatment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS General § 268.3 Dilution prohibited as a... circumvent a land disposal prohibition imposed by RCRA section 3004. (b) Dilution of wastes that are... hazardous wastes in order to achieve any land disposal restriction treatment standard for lead. Lead...

Dilution refrigeration for space applications

NASA Technical Reports Server (NTRS)

Israelsson, U. E.; Petrac, D.

1990-01-01

Dilution refrigerators are presently used routinely in ground based applications where temperatures below 0.3 K are required. The operation of a conventional dilution refrigerator depends critically on the presence of gravity. To operate a dilution refrigerator in space many technical difficulties must be overcome. Some of the anticipated difficulties are identified in this paper and possible solutions are described. A single cycle refrigerator is described conceptually that uses forces other than gravity to function and the stringent constraints imposed on the design by requiring the refrigerator to function on the earth without using gravity are elaborated upon.

Enumeration procedure for monitoring test microbe populations on inoculated carriers in AOAC use-dilution methods.

PubMed

Tomasino, Stephen F; Fiumara, Rebecca M; Cottrill, Michele P

2006-01-01

The AOAC Use-Dilution methods do not provide procedures to enumerate the test microbe on stainless steel carriers (penicylinders) or guidance on the expected target populations of the test microbe (i.e., a performance standard). This report describes the procedures used by the U.S. Environmental Protection Agency to enumerate the test microbe (carrier counts) associated with conducting the Use-Dilution method with Staphylococcus aureus (Method 955.15) and Pseudomonas aeruginosa (Method 964.02) and the examination of historical data. The carrier count procedure involves the random selection of carriers, shearing bacterial cells from the carrier surface through sonication, and plating of serially diluted inoculum on trypticase soy agar. For each Use-Dilution test conducted, the official AOAC method was strictly followed for carrier preparation, culture initiation, test culture preparation, and carrier inoculation steps. Carrier count data from 78 Use-Dilution tests conducted over a 6-year period were compiled and analyzed. A mean carrier count of 6.6 logs (approximately 4.0 x 10(6) colony-forming units/carrier) was calculated for both S. aureus and P. aeruginosa. Of the mean values, 95% fell within +/- 2 repeatability standard deviations. The enumeration procedure and target carrier counts are desirable for standardizing the Use-Dilution methods, increasing their reproducibility, and ensuring the quality of the data.

Estimation method for serial dilution experiments.

PubMed

Ben-David, Avishai; Davidson, Charles E

2014-12-01

Titration of microorganisms in infectious or environmental samples is a corner stone of quantitative microbiology. A simple method is presented to estimate the microbial counts obtained with the serial dilution technique for microorganisms that can grow on bacteriological media and develop into a colony. The number (concentration) of viable microbial organisms is estimated from a single dilution plate (assay) without a need for replicate plates. Our method selects the best agar plate with which to estimate the microbial counts, and takes into account the colony size and plate area that both contribute to the likelihood of miscounting the number of colonies on a plate. The estimate of the optimal count given by our method can be used to narrow the search for the best (optimal) dilution plate and saves time. The required inputs are the plate size, the microbial colony size, and the serial dilution factors. The proposed approach shows relative accuracy well within ±0.1log10 from data produced by computer simulations. The method maintains this accuracy even in the presence of dilution errors of up to 10% (for both the aliquot and diluent volumes), microbial counts between 10(4) and 10(12) colony-forming units, dilution ratios from 2 to 100, and plate size to colony size ratios between 6.25 to 200. Published by Elsevier B.V.

Wind tunnel measurements of the dilution of tailpipe emissions downstream of a car, a light-duty truck, and a heavy-duty truck tractor head.

PubMed

Chang, Victor W C; Hildemann, Lynn M; Chang, Cheng-hisn

2009-06-01

The particle and gaseous pollutants in vehicle exhaust emissions undergo rapid dilution with ambient air after exiting the tailpipe. The rate and extent of this dilution can greatly affect both the size evolution of primary exhaust particles and the potential for formation of ultrafine particles. Dilution ratios were measured inside of a wind tunnel in the region immediately downstream of the tailpipe using model vehicles (approximately one-fifth to one-seventh scale models) representing a light-duty truck, a passenger car, and a heavy-duty tractor head (without the trailer). A tracer gas (ethene) was released at a measured flow rate from the tailpipe, and 60 sampling probes placed downstream of the vehicle simultaneously sampled gas tracer concentrations in the near-wake (first few vehicle heights) and far-wake regions (beyond 10 vehicle heights). Tests using different tunnel wind speeds show the range of dilution ratios that can be expected as a function of vehicle type and downstream distance (i.e., time). The vehicle shape quite strongly influences dilution profiles in the near-wake region but is much less important in the far-wake region. The tractor generally produces higher dilution rates than the automobile and light-duty truck under comparable conditions.

Studies on the Ecological Adaptability of Growing Rice with Floating Bed on the Dilute Biogas Slurry

PubMed Central

Du, Qi; Cheng, Bowen; Liao, Zhiqi; Sun, Chengcheng

2016-01-01

This study aimed to explore the ecological adaptability and the possibility of growing rice with floating bed on the dilute biogas slurry. The results of the experiments show that the growth stage, rice plant height, and rice yield and quality were significantly affected by multiple dilutions; rice plants cultivated with 45 multiple dilutions had better ecological adaptability than others. In the 45 multiple dilutions' group, the yield of rice was 13.3 g/bucket (8 rice plants), milled rice rate was 63.1%, and the content of crude protein in the rice was 6.3%. The concentrations of heavy metals in the rice cultivated with 30 multiple dilutions' slurry, such as total lead, cadmium, mercury, chromium, and arsenic, were all below the national standard. The study shows that it is possible and safe to cultivate rice plants with no soil but diluted biogas slurry. In the experiments, the yield, milled rice rate, and crude protein of the rice cultivated with slurry were not as much as those of rice cultivated with regular way in soil. This study provides the basic theoretical support for the development of biogas projects and the potential achievement of organic farming in special agricultural facilities and circular economy. PMID:27882324

Validation of an ultrasound dilution technology for cardiac output measurement and shunt detection in infants and children.

PubMed

Lindberg, Lars; Johansson, Sune; Perez-de-Sa, Valeria

2014-02-01

To validate cardiac output measurements by ultrasound dilution technology (COstatus monitor) against those obtained by a transit-time ultrasound technology with a perivascular flow probe and to investigate ultrasound dilution ability to estimate pulmonary to systemic blood flow ratio in children. Prospective observational clinical trial. Pediatric cardiac operating theater in a university hospital. In 21 children (6.1 ± 2.6 kg, mean ± SD) undergoing heart surgery, cardiac output was simultaneously recorded by ultrasound dilution (extracorporeal arteriovenous loop connected to existing arterial and central venous catheters) and a transit-time ultrasound probe applied to the ascending aorta, and when possible, the main pulmonary artery. The pulmonary to systemic blood flow ratio estimated from ultrasound dilution curve analysis was compared with that estimated from transit-time ultrasound technology. Bland-Altman analysis of the whole cohort (90 pairs, before and after surgery) showed a bias between transit-time ultrasound (1.01 ± 0.47 L/min) and ultrasound dilution technology (1.03 ± 0.51 L/min) of -0.02 L/min, limits of agreement -0.3 to 0.3 L/min, and percentage error of 31%. In children with no residual shunts, the bias was -0.04 L/min, limits of agreement -0.28 to 0.2 L/min, and percentage error 19%. The pooled co efficient of variation was for the whole cohort 3.5% (transit-time ultrasound) and 6.3% (ultrasound dilution), and in children without shunt, it was 2.9% (transit-time ultrasound) and 4% (ultrasound dilution), respectively. Ultrasound dilution identified the presence of shunts (pulmonary to systemic blood flow ≠ 1) with a sensitivity of 100% and a specificity of 92%. Mean pulmonary to systemic blood flow ratio by transit-time ultrasound was 2.6 ± 1.0 and by ultrasound dilution 2.2 ± 0.7 (not significant). The COstatus monitor is a reliable technique to measure cardiac output in children with high sensitivity and specificity for detecting the presence of shunts.

Impact of pretreatment and downstream processing technologies on economics and energy in cellulosic ethanol production.

PubMed

Kumar, Deepak; Murthy, Ganti S

2011-09-05

While advantages of biofuel have been widely reported, studies also highlight the challenges in large scale production of biofuel. Cost of ethanol and process energy use in cellulosic ethanol plants are dependent on technologies used for conversion of feedstock. Process modeling can aid in identifying techno-economic bottlenecks in a production process. A comprehensive techno-economic analysis was performed for conversion of cellulosic feedstock to ethanol using some of the common pretreatment technologies: dilute acid, dilute alkali, hot water and steam explosion. Detailed process models incorporating feedstock handling, pretreatment, simultaneous saccharification and co-fermentation, ethanol recovery and downstream processing were developed using SuperPro Designer. Tall Fescue (Festuca arundinacea Schreb) was used as a model feedstock. Projected ethanol yields were 252.62, 255.80, 255.27 and 230.23 L/dry metric ton biomass for conversion process using dilute acid, dilute alkali, hot water and steam explosion pretreatment technologies respectively. Price of feedstock and cellulose enzymes were assumed as $50/metric ton and 0.517/kg broth (10% protein in broth, 600 FPU/g protein) respectively. Capital cost of ethanol plants processing 250,000 metric tons of feedstock/year was $1.92, $1.73, $1.72 and $1.70/L ethanol for process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Ethanol production cost of $0.83, $0.88, $0.81 and $0.85/L ethanol was estimated for production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Water use in the production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment was estimated 5.96, 6.07, 5.84 and 4.36 kg/L ethanol respectively. Ethanol price and energy use were highly dependent on process conditions used in the ethanol production plant. Potential for significant ethanol cost reductions exist in increasing pentose fermentation efficiency and reducing biomass and enzyme costs. The results demonstrated the importance of addressing the tradeoffs in capital costs, pretreatment and downstream processing technologies.

Impact of pretreatment and downstream processing technologies on economics and energy in cellulosic ethanol production

PubMed Central

2011-01-01

Background While advantages of biofuel have been widely reported, studies also highlight the challenges in large scale production of biofuel. Cost of ethanol and process energy use in cellulosic ethanol plants are dependent on technologies used for conversion of feedstock. Process modeling can aid in identifying techno-economic bottlenecks in a production process. A comprehensive techno-economic analysis was performed for conversion of cellulosic feedstock to ethanol using some of the common pretreatment technologies: dilute acid, dilute alkali, hot water and steam explosion. Detailed process models incorporating feedstock handling, pretreatment, simultaneous saccharification and co-fermentation, ethanol recovery and downstream processing were developed using SuperPro Designer. Tall Fescue (Festuca arundinacea Schreb) was used as a model feedstock. Results Projected ethanol yields were 252.62, 255.80, 255.27 and 230.23 L/dry metric ton biomass for conversion process using dilute acid, dilute alkali, hot water and steam explosion pretreatment technologies respectively. Price of feedstock and cellulose enzymes were assumed as $50/metric ton and 0.517/kg broth (10% protein in broth, 600 FPU/g protein) respectively. Capital cost of ethanol plants processing 250,000 metric tons of feedstock/year was $1.92, $1.73, $1.72 and $1.70/L ethanol for process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Ethanol production cost of $0.83, $0.88, $0.81 and $0.85/L ethanol was estimated for production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Water use in the production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment was estimated 5.96, 6.07, 5.84 and 4.36 kg/L ethanol respectively. Conclusions Ethanol price and energy use were highly dependent on process conditions used in the ethanol production plant. Potential for significant ethanol cost reductions exist in increasing pentose fermentation efficiency and reducing biomass and enzyme costs. The results demonstrated the importance of addressing the tradeoffs in capital costs, pretreatment and downstream processing technologies. PMID:21892958

Mixing zone and drinking water intake dilution factor and wastewater generation distributions to enable probabilistic assessment of down-the-drain consumer product chemicals in the U.S.

PubMed

Kapo, Katherine E; McDonough, Kathleen; Federle, Thomas; Dyer, Scott; Vamshi, Raghu

2015-06-15

Environmental exposure and associated ecological risk related to down-the-drain chemicals discharged by municipal wastewater treatment plants (WWTPs) are strongly influenced by in-stream dilution of receiving waters which varies by geography, flow conditions and upstream wastewater inputs. The iSTREEM® model (American Cleaning Institute, Washington D.C.) was utilized to determine probabilistic distributions for no decay and decay-based dilution factors in mean annual and low (7Q10) flow conditions. The dilution factors derived in this study are "combined" dilution factors which account for both hydrologic dilution and cumulative upstream effluent contributions that will differ depending on the rate of in-stream decay due to biodegradation, volatilization, sorption, etc. for the chemical being evaluated. The median dilution factors estimated in this study (based on various in-stream decay rates from zero decay to a 1h half-life) for WWTP mixing zones dominated by domestic wastewater flow ranged from 132 to 609 at mean flow and 5 to 25 at low flow, while median dilution factors at drinking water intakes (mean flow) ranged from 146 to 2×10(7) depending on the in-stream decay rate. WWTPs within the iSTREEM® model were used to generate a distribution of per capita wastewater generated in the U.S. The dilution factor and per capita wastewater generation distributions developed by this work can be used to conduct probabilistic exposure assessments for down-the-drain chemicals in influent wastewater, wastewater treatment plant mixing zones and at drinking water intakes in the conterminous U.S. In addition, evaluation of types and abundance of U.S. wastewater treatment processes provided insight into treatment trends and the flow volume treated by each type of process. Moreover, removal efficiencies of chemicals can differ by treatment type. Hence, the availability of distributions for per capita wastewater production, treatment type, and dilution factors at a national level provides a series of practical and powerful tools for building probabilistic exposure models. Copyright © 2015 Elsevier B.V. All rights reserved.

Genotoxicity of mercury used in chromosome aberration tests.

PubMed

Akiyama, M; Oshima, H; Nakamura, M

2001-01-01

The purpose of this study was to investigate the genotoxic effects of Hg released from dental amalgams. The chromosome aberration test was conducted using original extracts and their diluted solutions of conventional type amalgam and high copper amalgam. The concentrations of Hg, Cu and Ag in the original extract of high copper amalgam were 17.64, 7.97 and 43.90 microM, respectively. Those in the original extract of conventional type amalgam were 20.63, 7.87 and 14.79 microM, respectively. 10 and 30 microM Hg(2+) were also used for comparison. The frequency of chromosome aberrations was below 5% with 0 microM Hg(2+) and with a triple dilution of high copper amalgam extract, containing 5.88 microM Hg, 14.63 microM Cu and 2.65 microM Ag. However, 9.5% of the cells showed chromosome aberrations with a quadruple dilution of conventional type amalgam, containing 5.15 microM Hg, 3.69 microM Cu and 1.96 microM Ag. The amount of Hg in the quadruple dilution of conventional type amalgam was less than that in the triple dilution of high copper amalgam extract and 10 microM Hg(2+). A concentration of 30 microM Hg(2+) caused 34.5% of the cells to show chromosome aberrations while with a two-thirds dilution of high copper amalgam extract, containing 11.76 microM Hg, 29.26 microM Cu and 5.31 microM Ag, 58.5% of the cells showed chromosome aberrations. A two-thirds dilution of high copper amalgam extract induced more chromosome aberrations than 30 microM Hg(2+), although the amount of Hg was less than 30 microM Hg(2+). A triple dilution of conventional type amalgam extract, original extracts of conventional type amalgam and high copper amalgam and 100 microM Hg(2+) were induced few metaphases. It was revealed that the conventional type amalgam induced chromosome aberrations with quadruple dilution where cell viability was about 80% and that the high copper amalgam induced a high level of chromosome aberrations with the two-thirds dilution. The effects of low level Hg on humans are not clear.

Optimization and validation of enzyme-linked immunosorbent assay for the determination of endosulfan residues in food samples.

PubMed

Zhang, Yan; Liu, Jun W; Zheng, Wen J; Wang, Lei; Zhang, Hong Y; Fang, Guo Z; Wang, Shuo

2008-02-01

In this study, an enzyme-linked immunosorbent assay (ELISA) was optimized and applied to the determination of endosulfan residues in 20 different kinds of food commodities including vegetables, dry fruits, tea and meat. The limit of detection (IC(15)) was 0.8 microg kg(-1) and the sensitivity (IC(50)) was 5.3 microg kg(-1). Three simple extraction methods were developed, including shaking on the rotary shaker at 250 r min(-1) overnight, shaking on the rotary shaker for 1 h and thoroughly mixing for 2 min. Methanol was used as the extraction solvent in this study. The extracts were diluted in 0.5% fish skin gelatin (FG) in phosphate-buffered saline (PBS) at various dilutions in order to remove the matrix interference. For cabbage (purple and green), asparagus, Japanese green, Chinese cabbage, scallion, garland chrysanthemum, spinach and garlic, the extracts were diluted 10-fold; for carrots and tea, the extracts were diluted 15-fold and 900-fold, respectively. The extracts of celery, adzuki beans and chestnuts, were diluted 20-fold to avoid the matrix interference; ginger, vegetable soybean and peanut extracts were diluted 100-fold; mutton and chicken extracts were diluted 10-fold and for eel, the dilution was 40-fold. Average recoveries were 63.13-125.61%. Validation was conducted by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The results of this study will be useful to the wide application of an ELISA for the rapid determination of pesticides in food samples.

Comparison of gravimetric and a double-indicator dilution technique for assessment of extra-vascular lung water in endotoxaemia.

PubMed

Rossi, P; Oldner, A; Wanecek, M; Leksell, L G; Rudehill, A; Konrad, D; Weitzberg, E

2003-03-01

To compare a molecular double-indicator dilution technique with the gravimetrical reference method for measurement of extra-vascular lung water in porcine endotoxin shock. Open comparative experimental study. Animal research laboratory. In fourteen anaesthetised, mechanically ventilated landrace pigs, central and pulmonary haemodynamics as well as pulmonary gas exchange were measured. Extra-vascular lung water was quantitated gravimetrically as well as with a molecular double indicator dilution technique. Eight of these animals were subjected to endotoxaemia, the rest serving as sham controls. No difference in extra-vascular lung water was observed between the two methods in sham animals. Furthermore, extra-vascular lung water assessed with the molecular double-indicator dilution technique at the initiation of endotoxin infusion did not differ significantly from the corresponding values for sham animals. Endotoxaemia induced a hypodynamic shock with concurrent pulmonary hypertension and a pronounced deterioration in gas exchange. No increase in extra-vascular lung water was detected with the molecular double-indicator dilution technique in response to endotoxin, whereas this parameter was significantly higher when assessed with the gravimetric method. The molecular double-indicator dilution technique showed similar results as the gravimetrical method for assessment of extra-vascular lung water in non-endotoxaemic conditions. However, during endotoxin-induced lung injury the molecular double indicator dilution technique failed to detect the significant increase in extra-vascular lung water as measured by the gravimetric method. These data suggest that the molecular double indicator dilution technique may be of limited value during sepsis-induced lung injury.

Modeling syngas-fired gas turbine engines with two dilutants

NASA Astrophysics Data System (ADS)

Hawk, Mitchell E.

2011-12-01

Prior gas turbine engine modeling work at the University of Wyoming studied cycle performance and turbine design with air and CO2-diluted GTE cycles fired with methane and syngas fuels. Two of the cycles examined were unconventional and innovative. The work presented herein reexamines prior results and expands the modeling by including the impacts of turbine cooling and CO2 sequestration on GTE cycle performance. The simple, conventional regeneration and two alternative regeneration cycle configurations were examined. In contrast to air dilution, CO2 -diluted cycle efficiencies increased by approximately 1.0 percentage point for the three regeneration configurations examined, while the efficiency of the CO2-diluted simple cycle decreased by approximately 5.0 percentage points. For CO2-diluted cycles with a closed-exhaust recycling path, an optimum CO2-recycle pressure was determined for each configuration that was significantly lower than atmospheric pressure. Un-cooled alternative regeneration configurations with CO2 recycling achieved efficiencies near 50%, which was approximately 3.0 percentage points higher than the conventional regeneration cycle and simple cycle configurations that utilized CO2 recycling. Accounting for cooling of the first two turbine stages resulted in a 2--3 percentage point reduction in un-cooled efficiency, with air dilution corresponding to the upper extreme. Additionally, when the work required to sequester CO2 was accounted for, cooled cycle efficiency decreased by 4--6 percentage points, and was more negatively impacted when syngas fuels were used. Finally, turbine design models showed that turbine blades are shorter with CO2 dilution, resulting in fewer design restrictions.

Premature preterm rupture of the membrane diagnosis in early pregnancy: PAMG-1 and IGFBP-1 detection in amniotic fluid with biochemical tests.

PubMed

Doret, Muriel; Cartier, Régine; Miribel, Juliette; Massardier, Jérome; Massoud, Mona; Bordes, Agnès; Moret, Stéphanie; Gaucherand, Pascal

2013-12-01

Previable premature rupture of the membranes (pPROM), occurring before 24WG, is associated with a 25% neonatal survival rate. This terrible prognosis may lead to elective pregnancy termination on parents' request. Therefore, certain diagnosis is essential but remains difficult in about 10% of patients. Bed-side biochemical tests developed to help in diagnosis had never been evaluated in early pregnancies. This study aimed to evaluate and compare the in vitro sensitivity, detection limit, reaction time and consistency of AmniSure detecting placental alpha microglobulin-1 (PAMG-1) and actim PROM detecting Insulin Growth Factor Binding Protein-1 (IGFBP-1) in amniotic fluid between 15 and 20weeks of gestation (WG). Samples of amniotic fluid were collected by amniocentesis performed between 15 and 20 completed WG in 55 patients. Dilution series were prepared and both tests were performed twice at each dilution. In vitro sensitivity, detection limit, and reaction time were evaluated and compared in serial dilution. A total of 460 AmniSure and 476 actim PROM tests were performed. Both tests' in vitro sensitivity was 100% at dilution 1:20 and remained up to 90% until dilution 1:80. In vitro sensitivities were not different at any dilution. Detection limit and consistency were similar for both tests at all dilution. Actim PROM reaction time was shorter than AmniSure at all dilutions, except 1:320 (p<0.05). PAMG-1 and IGFBP-1 can be detected in amniotic fluid between 15 and 20 completed WG, using respectively AmniSure and actim PROM. © 2013.

The effects of inhomogeneous boundary dilution on the coating flow of an anti-HIV microbicide vehicle

NASA Astrophysics Data System (ADS)

Tasoglu, Savas; Peters, Jennifer J.; Park, Su Chan; Verguet, Stéphane; Katz, David F.; Szeri, Andrew J.

2011-09-01

A recent study in South Africa has confirmed, for the first time, that a vaginal gel formulation of the antiretroviral drug Tenofovir, when topically applied, significantly inhibits sexual HIV transmission to women [Karim et al., Science 329, 1168 (2010)]. However, the gel for this drug and anti-HIV microbicide gels in general have not been designed using an understanding of how gel spreading and retention in the vagina govern successful drug delivery. Elastohydrodynamic lubrication theory can be applied to model spreading of microbicide gels [Szeri et al., Phys. Fluids 20, 083101 (2008)]. This should incorporate the full rheological behavior of a gel, including how rheological properties change due to contact with, and dilution by, ambient vaginal fluids. Here, we extend our initial analysis, incorporating the effects of gel dilution due to contact with vaginal fluid produced at the gel-tissue interface. Our original model is supplemented with a convective-diffusive transport equation to characterize water transport into the gel and, thus, local gel dilution. The problem is solved using a multi-step scheme in a moving domain. The association between local dilution of gel and rheological properties is obtained experimentally, delineating the way constitutive parameters of a shear-thinning gel are modified by dilution. Results show that dilution accelerates the coating flow by creating a slippery region near the vaginal wall akin to a dilution boundary layer, especially if the boundary flux exceeds a certain value. On the other hand, if the diffusion coefficient of boundary fluid is increased, the slippery region diminishes in extent and the overall rate of gel spreading decreases.

Number of Siblings and Intellectual Development: The Resource Dilution Explanation.

ERIC Educational Resources Information Center

Downey, Douglas B.

2001-01-01

Resource dilution model suggests that as the number of children increases, parental resources for each child decline. Assesses whether resource dilution could explain the effect of siblings on intellectual development tests. Identifies flaws in recent critiques of this position, discussing it as an explanation for why children with few siblings…

A modified Lowry protein test for dilute protein solutions

Treesearch

Garold F. Gregory; Keith F. Jensen

1971-01-01

A modified Lowry protein test for dilute protein solutions modified Lowry protein test was compared with the standard Lowry protein test. The modified test was found to give estimates of protein concentration that were as good as the standard test and has the advange that proteins can be measured in very dilute solutions.

Effects of Fuel Laminar Flame Speed Compared to Engine Tumble Ratio, Ignition Energy, and Injection Strategy on Lean and EGR Dilute Spark Ignition Combustion

DOE PAGES

Kolodziej, Christopher P.; Pamminger, Michael; Sevik, James; ...

2017-03-28

Previously we show that fuels with higher laminar flame speed also have increased tolerance to EGR dilution. In this work, the effects of fuel laminar flame speed on both lean and EGR dilute spark ignition combustion stability were examined. Fuels blends of pure components (iso-octane, n-heptane, toluene, ethanol, and methanol) were derived at two levels of laminar flame speed. Each fuel blend was tested in a single-cylinder spark-ignition engine under both lean-out and EGR dilution sweeps until the coefficient of variance of indicated mean effective pressure increased above thresholds of 3% and 5%. The relative importance of fuel laminar flamemore » speed to changes to engine design parameters (spark ignition energy, tumble ratio, and port vs. direct injection) was also assessed. Our results showed that fuel laminar flame speed can have as big an effect on lean or EGR dilute engine operation as engine design parameters, with the largest effects seen during EGR dilute operation and when changes were made to cylinder charge motion.« less

Effects of Fuel Laminar Flame Speed Compared to Engine Tumble Ratio, Ignition Energy, and Injection Strategy on Lean and EGR Dilute Spark Ignition Combustion

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

Kolodziej, Christopher P.; Pamminger, Michael; Sevik, James

Previously we show that fuels with higher laminar flame speed also have increased tolerance to EGR dilution. In this work, the effects of fuel laminar flame speed on both lean and EGR dilute spark ignition combustion stability were examined. Fuels blends of pure components (iso-octane, n-heptane, toluene, ethanol, and methanol) were derived at two levels of laminar flame speed. Each fuel blend was tested in a single-cylinder spark-ignition engine under both lean-out and EGR dilution sweeps until the coefficient of variance of indicated mean effective pressure increased above thresholds of 3% and 5%. The relative importance of fuel laminar flamemore » speed to changes to engine design parameters (spark ignition energy, tumble ratio, and port vs. direct injection) was also assessed. Our results showed that fuel laminar flame speed can have as big an effect on lean or EGR dilute engine operation as engine design parameters, with the largest effects seen during EGR dilute operation and when changes were made to cylinder charge motion.« less

Hydrodynamic and chemical effects of hydrogen dilution on soot evolution in turbulent nonpremixed bluff body ethylene flames

NASA Astrophysics Data System (ADS)

Deng, Sili; Mueller, Michael E.; Chan, Qing N.; Qamar, Nader H.; Dally, Bassam B.; Alwahabi, Zeyad T.; Nathan, Graham J.

2015-11-01

A turbulent nonpremixed bluff body ethylene/hydrogen (volume ratio 2:1) flame is studied and compared with the ethylene counterpart [Mueller et al., Combust. Flame, 160, 2013]. Similar to the ethylene buff body flame, a low-strain recirculation zone, a high-strain neck region, and a downstream jet-like region are observed. However, the maximum soot volume fraction in the recirculation zone of the hydrogen diluted case is significantly lower than the ethylene case. Large Eddy Simulation is used to further investigate soot evolution in the recirculation zone and to elucidate the role of hydrogen dilution. Since the central jet Reynolds numbers in both cases are the same (approximately 30,900), the jet velocity of the hydrogen diluted case is higher, resulting in a shorter and leaner recirculation zone. In addition, hydrogen dilution chemically suppresses soot formation due to the reduction of C/H ratio. Consequently, the reduction of the soot volume fraction for the hydrogen diluted ethylene flame is attributed to two major effects: hydrodynamic and chemical effects.

Sugar yields from dilute oxalic acid pretreatment of maple wood compared to those with other dilute acids and hot water.

PubMed

Zhang, Taiying; Kumar, Rajeev; Wyman, Charles E

2013-01-30

Dilute oxalic acid pretreatment was applied to maple wood to improve compatibility with downstream operations, and its performance in pretreatment and subsequent enzymatic hydrolysis was compared to results for hydrothermal and dilute hydrochloric and sulfuric acid pretreatments. The highest total xylose yield of ∼84% of the theoretical maximum was for both 0.5% oxalic and sulfuric acid pretreatment at 160 °C, compared to ∼81% yield for hydrothermal pretreatment at 200 °C and for 0.5% hydrochloric acid pretreatment at 140 °C. The xylooligomer fraction from dilute oxalic acid pretreatment was only 6.3% of the total xylose in solution, similar to results with dilute hydrochloric and sulfuric acids but much lower than the ∼70% value for hydrothermal pretreatment. Combining any of the four pretreatments with enzymatic hydrolysis with 60 FPU cellulase/g of glucan plus xylan in the pretreated maple wood resulted in virtually the same total glucose plus xylose yields of ∼85% of the maximum possible. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fast and accurate calculation of dilute quantum gas using Uehling–Uhlenbeck model equation

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

Yano, Ryosuke, E-mail: ryosuke.yano@tokiorisk.co.jp

The Uehling–Uhlenbeck (U–U) model equation is studied for the fast and accurate calculation of a dilute quantum gas. In particular, the direct simulation Monte Carlo (DSMC) method is used to solve the U–U model equation. DSMC analysis based on the U–U model equation is expected to enable the thermalization to be accurately obtained using a small number of sample particles and the dilute quantum gas dynamics to be calculated in a practical time. Finally, the applicability of DSMC analysis based on the U–U model equation to the fast and accurate calculation of a dilute quantum gas is confirmed by calculatingmore » the viscosity coefficient of a Bose gas on the basis of the Green–Kubo expression and the shock layer of a dilute Bose gas around a cylinder.« less

Theory of a microfluidic serial dilution bioreactor for growth of planktonic and biofilm populations.

PubMed

Hsu, Sze-Bi; Yang, Ya-Tang

2016-04-01

We present the theory of a microfluidic bioreactor with a two-compartment growth chamber and periodic serial dilution. In the model, coexisting planktonic and biofilm populations exchange by adsorption and detachment. The criteria for coexistence and global extinction are determined by stability analysis of the global extinction state. Stability analysis yields the operating diagram in terms of the dilution and removal ratios, constrained by the plumbing action of the bioreactor. The special case of equal uptake function and logistic growth is analytically solved and explicit growth curves are plotted. The presented theory is applicable to generic microfluidic bioreactors with discrete growth chambers and periodic dilution at discrete time points. Therefore, the theory is expected to assist the design of microfluidic devices for investigating microbial competition and microbial biofilm growth under serial dilution conditions.

Diluted thrombin time reliably measures low to intermediate plasma dabigatran concentrations.

PubMed

Božič-Mijovski, Mojca; Malmström, Rickard E; Malovrh, Petra; Antovic, Jovan P; Vene, Nina; Šinigoj, Petra; Mavri, Alenka

2016-07-01

Direct oral anticoagulant dabigatran was first introduced as a fixed-dose drug without routine coagulation monitoring, but current recommendations suggest that diluted thrombin time can be used to estimate plasma drug level. The aim of this study was to assess a diluted thrombin time assay based on the same thrombin reagent already used for traditional thrombin time measurements that reliably measure low to intermediate plasma dabigatran levels. We included 44 patients with atrial fibrillation who started treatment with dabigatran 150 mg (23 patients) or 110 mg (21 patients) twice a day. Blood samples were collected at baseline (no dabigatran) and 2-4 weeks after the beginning of dabigatran therapy at trough and at peak. Plasma dabigatran levels were measured with diluted thrombin time and compared to liquid chromatography with tandem mass spectrometry as the reference method. The performance of the diluted thrombin time was compared to Hemoclot® Thrombin Inhibitor and Ecarin Chromogenic Assay. In ex vivo plasma samples, diluted thrombin time highly correlated with the liquid chromatography with tandem mass spectrometry (Pearson's R = 0.9799). In the low to intermediate range (dabigatran concentration ≤ 100 µg/L) diluted thrombin time correlated significantly more closely to the liquid chromatography with tandem mass spectrometry (R = 0.964) than Hemoclot® Thrombin Inhibitor (R = 0.935, p = 0.05) or Ecarin Chromogenic Assay (R = 0.915, p < 0.01). It was also the only functional assay without any significant bias in the low to intermediate range. Both trough and peak diluted thrombin time values were similar to liquid chromatography with tandem mass spectrometry. We conclude that the diluted thrombin time assay presented in this study reliably detects dabigatran and that it is superior to the Hemoclot® Thrombin Inhibitor assay in the low to intermediate range. © The Author(s) 2015.

Vitamins D and A can be successfully measured by LC-MS/MS in cord blood diluted plasma.

PubMed

Albarhani, Ali A; Collier, Fiona; Greaves, Ronda F; Ponsonby, Anne-Louise; Allen, Katrina J; Vuillermin, Peter J; Roche, Peter; Clarke, Michael W

2015-11-01

In widely used protocols for the collection and isolation of cord blood mononuclear cells, investigators are left with substantial volumes of diluted plasma which could be used for other measurements. The aim of this study was to ascertain the validity of umbilical cord blood (UCB) diluted plasma samples for vitamin D, A and E analysis compared to UCB serum samples. Twenty UCB matched samples of diluted plasma and serum were collected. The samples were analysed by two liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods on two separate occasions. The results of 25(OH)D3 obtained by the two laboratories demonstrated close agreement with a mean difference of 0.14nmol/L [95% confidence interval (95% CI), -6.8 to 7.1]. Both methods demonstrate close agreement for 25(OH)D3 in UCB serum versus diluted UCB plasma; mean difference 2.2nmol/L [95% CI, -9.5 to 13.9] and 4.1nmol/L [95% CI, -14.5 to 6.1] for the results from Lab A and Lab B, respectively. Vitamin A was quantified by Lab A in UCB serum and diluted UCB plasma; mean difference 0.07μmol/L [95% CI, -0.41 to 0.28]. Results of 25(OH)D3 epimer and vitamin E in the diluted UCB plasma were below the limit of quantification, and could not be compared with UCB serum. Diluted UCB plasma can be used for the quantification of retinol and 25(OH)D3 by LC-MS/MS. By contrast, quantification of 25(OH)D3 epimer and vitamin E in diluted UCB plasma is not supported by this study due to limitations in analytical sensitivity. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Attentional sets influence perceptual load effects, but not dilution effects.

PubMed

Benoni, Hanna; Zivony, Alon; Tsal, Yehoshua

2014-01-01

Perceptual load theory [Lavie, N. (1995). Perceptual load as a necessary condition for selective attention. Journal of Experimental Psychology: Human Perception and Performance, 21, 451-468.; Lavie, N., & Tsal, Y. (1994) Perceptual load as a major determinant of the locus of selection in visual attention. Perception & Psychophysics, 56, 183-197.] proposes that interference from distractors can only be avoided in situations of high perceptual load. This theory has been supported by blocked design manipulations separating low load (when the target appears alone) and high load (when the target is embedded among neutral letters). Tsal and Benoni [(2010a). Diluting the burden of load: Perceptual load effects are simply dilution effects. Journal of Experimental Psychology: Human Perception and Performance, 36, 1645-1656.; Benoni, H., & Tsal, Y. (2010). Where have we gone wrong? Perceptual load does not affect selective attention. Vision Research, 50, 1292-1298.] have recently shown that these manipulations confound perceptual load with "dilution" (the mere presence of additional heterogeneous items in high-load situations). Theeuwes, Kramer, and Belopolsky [(2004). Attentional set interacts with perceptual load in visual search. Psychonomic Bulletin & Review, 11, 697-702.] independently questioned load theory by suggesting that attentional sets might also affect distractor interference. When high load and low load were intermixed, and participants could not prepare for the presentation that followed, both the low-load and high-load trials showed distractor interference. This result may also challenge the dilution account, which proposes a stimulus-driven mechanism. In the current study, we presented subjects with both fixed and mixed blocks, including a mix of dilution trials with low-load trials and with high-load trials. We thus separated the effect of dilution from load and tested the influence of attentional sets on each component. The results revealed that whereas perceptual load effects are influenced by attentional sets, the dilution component is not. This strengthens the notion that dilution is a stimulus-driven mechanism, which enables effective selectivity.

High-dose HOOK effect in urinary DcR2 assay in patients with chronic kidney disease.

PubMed

Chen, Jia; Chen, Ke-Hong; Wang, Li-Ming; Zhang, Wei-Wei; Feng, Lei; Dai, Huan-Zi; He, Ya-Ni

2018-06-05

Urinary DcR2 (uDcR2) is a biomarker for the early detection the tubulointerstitial injury (TII) in patients with chronic kidney disease (CKD), but the high-dose hook effect may lead to falsely low or even negative results when using an enzyme-linked immunosorbent assay (ELISA). This study aimed to investigate if the high-dose hook effect exists with ELISA testing, and to uncover a potential approach for reducing this effect. 72 CKD patients were recruited and categorized into four groups based on TII scores. uDcR2 was measured in undiluted and serially diluted (two-, four-, eight- and 16-fold dilutions) urine using an ELISA kit. The results from the assay were normalized to urinary creatinine. We evaluated the correlation between uDcR2/cre levels at different dilutions and renal histological parameters. Receiver operating characteristic (ROC) curves were generated to examine the value of uDcR2/cre for predicting TII. uDcR2/cre levels in the undiluted urine were significantly higher in patients with CKD than those in the control. However, higher TII scores did not yield higher levels of uDcR2/cre in the undiluted urine. After serial dilution, uDcR2/cre levels were highest with the four-fold dilution. A positive correlation was found between uDcR2/cre levels at different dilutions and TII scores, with the highest correlation coefficient and the largest AUC being observed at the four-fold dilution. The high-dose hook effect was apparent during ELISA testing of uDcR2 in CKD patients, yet dilution of the urine samples neutralized this effect. However, the use of a four-fold dilution of urine for uDcR2/cre testing may eliminate the high-dose hook effect and make it possible to effectively monitor the severity of TII in CKD patients. Copyright © 2018. Published by Elsevier Inc.

Low probability of a dilution effect for Lyme borreliosis in Belgian forests.

PubMed

Ruyts, Sanne C; Landuyt, Dries; Ampoorter, Evy; Heylen, Dieter; Ehrmann, Steffen; Coipan, Elena C; Matthysen, Erik; Sprong, Hein; Verheyen, Kris

2018-04-22

An increasing number of studies have investigated the consequences of biodiversity loss for the occurrence of vector-borne diseases such as Lyme borreliosis, the most common tick-borne disease in the northern hemisphere. As host species differ in their ability to transmit the Lyme borreliosis bacteria Borrelia burgdorferi s.l. to ticks, increased host diversity can decrease disease prevalence by increasing the proportion of dilution hosts, host species that transmit pathogens less efficiently. Previous research shows that Lyme borreliosis risk differs between forest types and suggests that a higher diversity of host species might dilute the contribution of small rodents to infect ticks with B. afzelii, a common Borrelia genospecies. However, empirical evidence for a dilution effect in Europe is largely lacking. We tested the dilution effect hypothesis in 19 Belgian forest stands of different forest types along a diversity gradient. We used empirical data and a Bayesian belief network to investigate the impact of the proportion of dilution hosts on the density of ticks infected with B. afzelii, and identified the key drivers determining the density of infected ticks, which is a measure of human infection risk. Densities of ticks and B. afzelii infection prevalence differed between forest types, but the model indicated that the density of infected ticks is hardly affected by dilution. The most important variables explaining variability in disease risk were related to the density of ticks. Combining empirical data with a model-based approach supported decision making to reduce tick-borne disease risk. We found a low probability of a dilution effect for Lyme borreliosis in a north-western European context. We emphasize that under these circumstances, Lyme borreliosis prevention should rather aim at reducing tick-human contact rate instead of attempting to increase the proportion of dilution hosts. Copyright © 2018. Published by Elsevier GmbH.

A Candide response to Panglossian accusations by Randolph and Dobson: biodiversity buffers disease.

PubMed

Ostfeld, Richard S

2013-09-01

Randolph and Dobson (2012) criticize the dilution effect, which describes the negative relationship between biodiversity and infectious disease risk. Unfortunately, their commentary includes distortions, errors of omission, and errors of commission, which are rebutted herein. Contrary to their claims, the dilution effect is not a 'mantra' that asserts that reduced disease risk is a 'universal' outcome of high diversity. Although universality of the dilution effect has not been claimed, and conditions under which diversity can amplify disease risk have been described, the growing literature indicates that the dilution effect is indeed a widespread phenomenon.

On the Wigner law in dilute random matrices

NASA Astrophysics Data System (ADS)

Khorunzhy, A.; Rodgers, G. J.

1998-12-01

We consider ensembles of N × N symmetric matrices whose entries are weakly dependent random variables. We show that random dilution can change the limiting eigenvalue distribution of such matrices. We prove that under general and natural conditions the normalised eigenvalue counting function coincides with the semicircle (Wigner) distribution in the limit N → ∞. This can be explained by the observation that dilution (or more generally, random modulation) eliminates the weak dependence (or correlations) between random matrix entries. It also supports our earlier conjecture that the Wigner distribution is stable to random dilution and modulation.

Two-stage dilute acid prehydrolysis of biomass

DOEpatents

Grohmann, Karel; Torget, Robert W.

1992-01-01

A two-stage dilute acid prehydrolysis process on xylan containing hemicellulose in biomass is effected by: treating feedstock of hemicellulosic material comprising xylan that is slow hydrolyzable and xylan that is fast hydrolyzable under predetermined low temperature conditions with a dilute acid for a residence time sufficient to hydrolyze the fast hydrolyzable xylan to xylose; removing said xylose from said fast hydrolyzable xylan and leaving a residue; and treating said residue having a slow hydrolyzable xylan with a dilute acid under predetermined high temperature conditions for a residence time required to hydrolyze said slow hydrolyzable xylan to xylose.

Where have we gone wrong? Perceptual load does not affect selective attention.

PubMed

Benoni, Hanna; Tsal, Yehoshua

2010-06-18

The theory of perceptual load (Lavie & Tsal, 1994) proposes that with low load in relevant processing left over resources spill over to process irrelevant distractors. Interference could only be prevented under High-Load Conditions where relevant processing exhausts attentional resources. The theory is based primarily on the finding that distractor interference obtained in low load displays, when the target appears alone, is eliminated in high load displays when it is embedded among neutral letters. However, a possible alternative interpretation of this effect is that the distractor is similarly processed in both displays, yet its interference in the large displays is diluted by the presence of the neutral letters. We separated the possible effects of load and dilution by adding dilution displays that were high in dilution and low in perceptual load. In the first experiment these displays contained as many letters as the high load displays, but their neutral letters were clearly distinguished from the target, thereby allowing for a low load processing mode. In the second experiment we presented identical multicolor displays in the Dilution and High-Load Conditions. However, in the former the target color was known in advance (thereby preserving a low load processing mode) whereas in the latter it was not. In both experiments distractor interference was completely eliminated under the Dilution Condition. Thus, it is dilution not perceptual load affecting distractor processing. 2010 Elsevier Ltd. All rights reserved.

Sensitivity of the activated partial thromboplastin time, the dilute Russell's viper venom time, and the kaolin clotting time for the detection of the lupus anticoagulant: a direct comparison using plasma dilutions.

PubMed

Martin, B A; Branch, D W; Rodgers, G M

1996-01-01

Increasing dilutions of lupus anticoagulant (LA) plasmas from twelve patients were used to directly compare the sensitivity of four tests for LA. The tests evaluated were the modified Bell and Alton activated partial thromboplastin time (APTT), an APTT using a commercially prepared partial thromboplastin (Platelin LS APTT), a modified dilute Russell's viper venom time (DRVVT), and a modified kaolin clotting time (KCT). LAs were detected in all twelve plasmas by each of three tests and eleven of twelve plasmas in a fourth test when undiluted patient plasma was used. Repeating the tests after diluting the LA plasmas with normal platelet-free plasma (PFP) showed that the KCT was the most sensitive test for LA, detecting eleven of twelve LAs at a dilution of 10% patient plasma and ten of twelve LAs at a dilution of 5% patient plasma. The modified Bell and Alton APTT and the modified DRVVT had similar sensitivities at a patient plasma concentration of 10%, detecting seven of twelve and eight of twelve LAs, respectively. The Platelin LS APTT detected only four of twelve LAs at a patient plasma concentration of 10%. Our results indicate that the modified KCT is a sensitive method for the detection of LAs. The modified Bell and Alton APTT and the DRVVT were less sensitive.

Gluconeogenesis from labeled carbon: estimating isotope dilution

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

Kelleher, J.K.

1986-03-01

To estimate the rate of gluconeogenesis from steady-state incorporation of labeled 3-carbon precursors into glucose, isotope dilution must be considered so that the rate of labeling of glucose can be quantitatively converted to the rate of gluconeogenesis. An expression for the value of this isotope dilution can be derived using mathematical techniques and a model of the tricarboxylic acid (TCA) cycle. The present investigation employs a more complex model than that used in previous studies. This model includes the following pathways that may affect the correction for isotope dilution: 1) flux of 3-carbon precursor to the oxaloacetate pool via acetyl-CoAmore » and the TCA cycle; 2) flux of 4- or 5-carbon compounds into the TCA cycle; 3) reversible flux between oxaloacetate (OAA) and pyruvate and between OAA and fumarate; 4) incomplete equilibrium between OAA pools; and 5) isotope dilution of 3-carbon tracers between the experimentally measured pool and the precursor for the TCA-cycle OAA pool. Experimental tests are outlined which investigators can use to determine whether these pathways are significant in a specific steady-state system. The study indicated that flux through these five pathways can significantly affect the correction for isotope dilution. To correct for the effects of these pathways an alternative method for calculating isotope dilution is proposed using citrate to relate the specific activities of acetyl-CoA and OAA.« less

Antibacterial activity of four mouthrinses containing triclosan against salivary Staphylococcus aureus

PubMed Central

Tanomaru, Juliane Maria Guerreiro; Nascimento, Andresa Piacezzi; Watanabe, Evandro; Matoba-Júnior, Fumio; Tanomaru-Filho, Mário; Ito, Izabel Yoko

2008-01-01

The maximum inhibitory dilution (MID) of triclosan-based mouthwashes against 28 Staphylococcus aureus strains was evaluated. Dilutions ranging from 1/10 to 1/655,360 were prepared. Strains were inoculated using a Steers multipoint inoculator. The MID was considered as the maximum dilution capable of inhibiting microorganism growth. The mouthwashes presented different MIDs. PMID:24031267

Antibacterial activity of four mouthrinses containing triclosan against salivary Staphylococcus aureus.

PubMed

Tanomaru, Juliane Maria Guerreiro; Nascimento, Andresa Piacezzi; Watanabe, Evandro; Matoba-Júnior, Fumio; Tanomaru-Filho, Mário; Ito, Izabel Yoko

2008-07-01

The maximum inhibitory dilution (MID) of triclosan-based mouthwashes against 28 Staphylococcus aureus strains was evaluated. Dilutions ranging from 1/10 to 1/655,360 were prepared. Strains were inoculated using a Steers multipoint inoculator. The MID was considered as the maximum dilution capable of inhibiting microorganism growth. The mouthwashes presented different MIDs.

40 CFR 1065.546 - Validation of minimum dilution ratio for PM batch sampling.

Code of Federal Regulations, 2012 CFR

2012-07-01

... chemical balance terms as given in § 1065.655(e). You may determine the raw exhaust flow rate based on the measured intake air and dilute exhaust molar flow rates and the dilute exhaust chemical balance terms as... air, fuel rate measurements, and fuel properties, consistent with good engineering judgment. (b...

40 CFR 1065.546 - Validation of minimum dilution ratio for PM batch sampling.

Code of Federal Regulations, 2013 CFR

2013-07-01

... chemical balance terms as given in § 1065.655(e). You may determine the raw exhaust flow rate based on the measured intake air and dilute exhaust molar flow rates and the dilute exhaust chemical balance terms as... air, fuel rate measurements, and fuel properties, consistent with good engineering judgment. (b...

40 CFR 1065.546 - Verification of minimum dilution ratio for PM batch sampling.

Code of Federal Regulations, 2014 CFR

2014-07-01

... chemical balance terms as given in § 1065.655(e). You may determine the raw exhaust flow rate based on the measured intake air and dilute exhaust molar flow rates and the dilute exhaust chemical balance terms as... air, fuel rate measurements, and fuel properties, consistent with good engineering judgment. (b...

Structural and functional comparison of mobile and recalcitrant humic fractions from agricultural soils

USDA-ARS?s Scientific Manuscript database

Mobile humic acid (MHA) and calcium humate (CaHA) are humic fractions sequentially extracted from soil samples. MHA is extracted by dilute NaOH, and CaHA is subsequently extracted by dilute NaOH from the dilute HCl-washed soil residues of the first extraction. This chapter reviews the recent advance...

Dilution effects on ultrafine particle emissions from Euro 5 and Euro 6 diesel and gasoline vehicles

NASA Astrophysics Data System (ADS)

Louis, Cédric; Liu, Yao; Martinet, Simon; D'Anna, Barbara; Valiente, Alvaro Martinez; Boreave, Antoinette; R'Mili, Badr; Tassel, Patrick; Perret, Pascal; André, Michel

2017-11-01

Dilution and temperature used during sampling of vehicle exhaust can modify particle number concentration and size distribution. Two experiments were performed on a chassis dynamometer to assess exhaust dilution and temperature on particle number and particle size distribution for Euro 5 and Euro 6 vehicles. In the first experiment, the effects of dilution (ratio from 8 to 4 000) and temperature (ranging from 50 °C to 150 °C) on particle quantification were investigated directly from tailpipe for a diesel and a gasoline Euro 5 vehicles. In the second experiment, particle emissions from Euro 6 diesel and gasoline vehicles directly sampled from the tailpipe were compared to the constant volume sampling (CVS) measurements under similar sampling conditions. Low primary dilutions (3-5) induced an increase in particle number concentration by a factor of 2 compared to high primary dilutions (12-20). Low dilution temperatures (50 °C) induced 1.4-3 times higher particle number concentration than high dilution temperatures (150 °C). For the Euro 6 gasoline vehicle with direct injection, constant volume sampling (CVS) particle number concentrations were higher than after the tailpipe by a factor of 6, 80 and 22 for Artemis urban, road and motorway, respectively. For the same vehicle, particle size distribution measured after the tailpipe was centred on 10 nm, and particles were smaller than the ones measured after CVS that was centred between 50 nm and 70 nm. The high particle concentration (≈106 #/cm3) and the growth of diameter, measured in the CVS, highlighted aerosol transformations, such as nucleation, condensation and coagulation occurring in the sampling system and this might have biased the particle measurements.

Comparison of homeopathic globules prepared from high and ultra-high dilutions of various starting materials by ultraviolet light spectroscopy.

PubMed

Klein, Sabine D; Wolf, Ursula

2016-02-01

Homeopathic globules are commonly used in clinical practice, while research focuses on liquid potencies. Sequential dilution and succussion in their production process has been proposed to change the physico-chemical properties of the solvent(s). It has been reported that aqueous potencies of various starting materials showed significant differences in ultraviolet light transmission compared to controls and between different dilution levels. The aim of the present study was to repeat and expand these experiments to homeopathic globules. Globules were specially produced for this study by Spagyros AG (Gümligen, Switzerland) from 6 starting materials (Aconitum napellus, Atropa belladonna, phosphorus, sulfur, Apis mellifica, quartz) and for 6 dilution levels (6x, 12x, 30c, 200c, 200CF (centesimal discontinuous fluxion), 10,000CF). Native globules and globules impregnated with solvents were used as controls. Globules were dissolved in ultrapure water, and absorbance in the ultraviolet range was measured. The average absorbance from 200 to 340nm was calculated and corrected for differences between measurement days and instrumental drift. Statistically significant differences were found for A. napellus, sulfur, and A. mellifica when normalized average absorbance of the various dilution levels from the same starting material (including control and solvent control globules) was compared. Additionally, absorbance within dilution levels was compared among the various starting materials. Statistically significant differences were found among 30c, 200c and 200CF dilutions. This study has expanded previous findings from aqueous potencies to globules and may indicate that characteristics of aqueous high dilutions may be preserved and detectable in dissolved globules. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Doping control analysis of 46 polar drugs in horse plasma and urine using a 'dilute-and-shoot' ultra high performance liquid chromatography-high resolution mass spectrometry approach.

PubMed

Kwok, Wai Him; Choi, Timmy L S; Kwok, Karen Y; Chan, George H M; Wong, Jenny K Y; Wan, Terence S M

2016-06-17

The high sensitivity of ultra high performance liquid chromatography coupled with high resolution mass spectrometry (UHPLC-HRMS) allows the identification of many prohibited substances without pre-concentration, leading to the development of simple and fast 'dilute-and-shoot' methods for doping control for human and equine sports. While the detection of polar drugs in plasma and urine is difficult using liquid-liquid or solid-phase extraction as these substances are poorly extracted, the 'dilute-and-shoot' approach is plausible. This paper describes a 'dilute-and-shoot' UHPLC-HRMS screening method to detect 46 polar drugs in equine urine and plasma, including some angiotensin-converting enzyme (ACE) inhibitors, sympathomimetics, anti-epileptics, hemostatics, the new doping agent 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR), as well as two threshold substances, namely dimethyl sulfoxide and theobromine. For plasma, the sample (200μL) was protein precipitated using trichloroacetic acid, and the resulting supernatant was diluted using Buffer A with an overall dilution factor of 3. For urine, the sample (20μL) was simply diluted 50-fold with Buffer A. The diluted plasma or urine sample was then analysed using a UHPLC-HRMS system in full-scan ESI mode. The assay was validated for qualitative identification purpose. This straightforward and reliable approach carried out in combination with other screening procedures has increased the efficiency of doping control analysis in the laboratory. Moreover, since the UHPLC-HRMS data were acquired in full-scan mode, the method could theoretically accommodate an unlimited number of existing and new doping agents, and would allow a retrospectively search for drugs that have not been targeted at the time of analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Impact of dilution on microbial community structure and functional potential: comparison of numerical simulations and batch culture experiments

NASA Technical Reports Server (NTRS)

Franklin, R. B.; Garland, J. L.; Bolster, C. H.; Mills, A. L.

2001-01-01

A series of microcosm experiments was performed using serial dilutions of a sewage microbial community to inoculate a set of batch cultures in sterile sewage. After inoculation, the dilution-defined communities were allowed to regrow for several days and a number of community attributes were measured in the regrown assemblages. Based upon a set of numerical simulations, community structure was expected to differ along the dilution gradient; the greatest differences in structure were anticipated between the undiluted-low-dilution communities and the communities regrown from the very dilute (more than 10(-4)) inocula. Furthermore, some differences were expected among the lower-dilution treatments (e.g., between undiluted and 10(-1)) depending upon the evenness of the original community. In general, each of the procedures used to examine the experimental community structures separated the communities into at least two, often three, distinct groups. The groupings were consistent with the simulated dilution of a mixture of organisms with a very uneven distribution. Significant differences in community structure were detected with genetic (amplified fragment length polymorphism and terminal restriction fragment length polymorphism), physiological (community level physiological profiling), and culture-based (colony morphology on R2A agar) measurements. Along with differences in community structure, differences in community size (acridine orange direct counting), composition (ratio of sewage medium counts to R2A counts, monitoring of each colony morphology across the treatments), and metabolic redundancy (i.e., generalist versus specialist) were also observed, suggesting that the differences in structure and diversity of communities maintained in the same environment can be manifested as differences in community organization and function.

The integration of dilute acid hydrolysis of xylan and fast pyrolysis of glucan to obtain fermentable sugars.

PubMed

Jiang, Liqun; Wu, Nannan; Zheng, Anqing; Zhao, Zengli; He, Fang; Li, Haibin

2016-01-01

Fermentable sugars are important intermediates in the biological conversion of biomass. Hemicellulose and amorphous cellulose are easily hydrolyzed to fermentable sugars in dilute acid, whereas crystalline cellulose is more difficult to be hydrolyzed. Cellulose fast pyrolysis is an alternative method to liberate valuable fermentable sugars from biomass. The amount of levoglucosan generated from lignocellulose by fast pyrolysis is usually lower than the theoretical yield based on the cellulose fraction. Pretreatment is a promising route to improve the yield of levoglucosan from lignocellulose. The integration of dilute sulfuric acid hydrolysis and fast pyrolysis to obtain fermentable sugars was evaluated in this study. Dilute sulfuric acid hydrolysis could remove more than 95.1 and 93.4 % of xylan (the main component of hemicellulose) from sugarcane bagasse and corncob with high yield of xylose. On the other hand, dilute sulfuric acid hydrolysis was also an effective pretreatment to enhance levoglucosan yield from lignocellulose. Dilute acid hydrolysis could accumulate glucan (the component of cellulose) and remove most of the alkali and alkaline earth metals which were powerful catalysts during fast pyrolysis. Further increase in dilute acid concentration (from 0 to 2 %) in pretreatment could promote the yield of levoglucosan in fast pyrolysis. The acid pretreated sugarcane bagasse and corncob gave levoglucosan yields of 43.8 and 35.2 % which were obvious higher than those of raw sugarcane bagasse (12.0 %) and corncob (7.0 %). Obtaining fermentable sugars by combination dilute acid hydrolysis of xylan and fast pyrolysis of glucan could make full utilization of biomass, and get fermentable sugars economically from biomass for bio-refinery.

The effects of sewage discharge on water quality and phytoplankton of Hawai'ian coastal waters.

PubMed

Parnell, P Ed

2003-05-01

The effects of sewage discharge on algal populations and the quality of Hawai'ian coastal waters were investigated. Two outfalls were studied. One discharges primary treated sewage and the other discharges secondary treated sewage but are otherwise similar. This enabled comparisons of the effects of these different levels of treatment on the water quality and algal productivity of receiving waters. Plumes were followed and repeatedly sampled in a time-series manner. Rhodamine dye was used as a conservative tracer to compare the dilution behavior of the plume constituents MRP, NO(3)+NO(2), NH(4), Silicate, TDP, TDN, total bacteria, PC, and PN. Rates of initial dilution ranged from two to almost three orders of magnitude, and were in reasonable agreement with engineering model predictions. Dilution of plume constituents approximated that of Rhodamine until background concentrations were reached, typically within 10 min of discharge. Chl a concentrations did not increase through time in the primary sewage plume but did increase up to 30% in the secondary sewage plume. However, rates of far-field dilution were so rapid that the increase could not have been due to algal growth. The increase was attributed to the plume mixing with a water mass whose relative chl a concentrations were greater. Rates of secondary dilution ranged from 2 to 3 orders of magnitude resulting in total dilutions of 10(5)-10(6) within 3 h of discharge. These rates of secondary dilution were much greater than model predictions. From a nutrient standpoint, secondary treatment exhibited no advantages over primary treatment because dilutions were so rapid. Copyright 2002 Elsevier Science B.V.

Determination of diffusion coefficients of various livestock antibiotics in water at infinite dilution

NASA Astrophysics Data System (ADS)

Soriano, Allan N.; Adamos, Kristoni G.; Bonifacio, Pauline B.; Adornado, Adonis P.; Bungay, Vergel C.; Vairavan, Rajendaran

2017-11-01

The fate of antibiotics entering the environment raised concerns on the possible effect of antimicrobial resistance bacteria. Prediction of the fate and transport of these particles are needed to be determined, significantly the diffusion coefficient of antibiotic in water at infinite dilution. A systematic determination of diffusion coefficient of antibiotic in water at infinite dilution of five different kinds of livestock antibiotics namely: Amtyl, Ciprotyl, Doxylak Forte, Trisullak, and Vetracin Gold in the 293.15 to 313.15 K temperature range are reported through the use of the method involving the electrolytic conductivity measurements. A continuous stirred tank reactor is utilized to measure the electrolytic conductivities of the considered systems. These conductivities are correlated by using the Nernst-Haskell equation to determine the infinite dilution diffusion coefficient. Determined diffusion coefficients are based on the assumption that in dilute solution, these antibiotics behave as strong electrolyte from which H+ cation dissociate from the antibiotic's anion.

3-D Surface Visualization of pH Titration "Topos": Equivalence Point Cliffs, Dilution Ramps, and Buffer Plateaus

ERIC Educational Resources Information Center

Smith, Garon C.; Hossain, Md Mainul; MacCarthy, Patrick

2014-01-01

3-D topographic surfaces ("topos") can be generated to visualize how pH behaves during titration and dilution procedures. The surfaces are constructed by plotting computed pH values above a composition grid with volume of base added in one direction and overall system dilution on the other. What emerge are surface features that…

RM Methods for Multiple Fare Structure Environments

DTIC Science & Technology

2008-06-01

110 9 LIST OF FIGURES 1 INTRODUCTION Figure 1-1: Revenue Losses due to Overprotection and Dilution... overprotection or dilution. If an airline’s objective is to focus on high-yield business travelers and charge only a single high fare for the...Lost Revenue from Customer Surplus Captured Revenue Rejected Passengers Overprotection Dilution Figure 1-1: Revenue Losses due to Overprotection

40 CFR 1065.308 - Continuous gas analyzer system-response and updating-recording verification-for gas analyzers not...

Code of Federal Regulations, 2012 CFR

2012-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications § 1065.308 Continuous..., the gas concentrations must be adjusted to account for the dilution from ambient air drawn into the... recommended when blending span gases diluted in N2 with span gases diluted in air. You may use a multi-gas...

40 CFR 1065.308 - Continuous gas analyzer system-response and updating-recording verification-for gas analyzers not...

Code of Federal Regulations, 2013 CFR

2013-07-01

...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications § 1065.308 Continuous..., the gas concentrations must be adjusted to account for the dilution from ambient air drawn into the... recommended when blending span gases diluted in N2 with span gases diluted in air. You may use a multi-gas...

Dilute sulfuric acid pretreatment of corn stover for enzymatic hydrolysis and efficient ethanol production by recombinant Escherichia coli FBR5 without detoxification

USDA-ARS?s Scientific Manuscript database

A pretreatment strategy for dilute H2SO4 pretreatment of corn stover was developed for the purpose of reducing the generation of inhibitory substances during pretreatment so that a detoxification step is not required prior to fermentation while maximizing the sugar yield. We have optimized dilute su...

Declining ecosystem health and the dilution effect.

PubMed

Khalil, Hussein; Ecke, Frauke; Evander, Magnus; Magnusson, Magnus; Hörnfeldt, Birger

2016-08-08

The "dilution effect" implies that where species vary in susceptibility to infection by a pathogen, higher diversity often leads to lower infection prevalence in hosts. For directly transmitted pathogens, non-host species may "dilute" infection directly (1) and indirectly (2). Competitors and predators may (1) alter host behavior to reduce pathogen transmission or (2) reduce host density. In a well-studied system, we tested the dilution of the zoonotic Puumala hantavirus (PUUV) in bank voles (Myodes glareolus) by two competitors and a predator. Our study was based on long-term PUUV infection data (2003-2013) in northern Sweden. The field vole (Microtus agrestis) and the common shrew (Sorex araneus) are bank vole competitors and Tengmalm's owl (Aegolius funereus) is a main predator of bank voles. Infection probability in bank voles decreased when common shrew density increased, suggesting that common shrews reduced PUUV transmission. Field voles suppressed bank vole density in meadows and clear-cuts and indirectly diluted PUUV infection. Further, Tengmalm's owl decline in 1980-2013 may have contributed to higher PUUV infection rates in bank voles in 2003-2013 compared to 1979-1986. Our study provides further evidence for dilution effect and suggests that owls may have an important role in reducing disease risk.

Quantifying the dilution effect for models in ecological epidemiology.

PubMed

Roberts, M G; Heesterbeek, J A P

2018-03-01

The dilution effect , where an increase in biodiversity results in a reduction in the prevalence of an infectious disease, has been the subject of speculation and controversy. Conversely, an amplification effect occurs when increased biodiversity is related to an increase in prevalence. We explore the conditions under which these effects arise, using multi species compartmental models that integrate ecological and epidemiological interactions. We introduce three potential metrics for quantifying dilution and amplification, one based on infection prevalence in a focal host species, one based on the size of the infected subpopulation of that species and one based on the basic reproduction number. We introduce our approach in the simplest epidemiological setting with two species, and show that the existence and strength of a dilution effect is influenced strongly by the choices made to describe the system and the metric used to gauge the effect. We show that our method can be generalized to any number of species and to more complicated ecological and epidemiological dynamics. Our method allows a rigorous analysis of ecological systems where dilution effects have been postulated, and contributes to future progress in understanding the phenomenon of dilution in the context of infectious disease dynamics and infection risk. © 2018 The Author(s).

Oxalate content of different drinkable dilutions of tea infusions after different brewing times.

PubMed

Lotfi Yagin, Neda; Mahdavi, Reza; Nikniaz, Zeinab

2012-01-01

The aims of this study were to determine the effect of different brewing times and diluting on oxalate content of loose-packed black teas consumed in Tabriz, Iran. The oxalate content of black teas after brewing for 5, 10, 15, 30, 60 minutes was measured in triplicate by enzymatic assay. In order to attain the most acceptable dilution of tea infusions, tea samples which were brewed for 15, 30 and 60 minutes were diluted two (120 ml), three (80 ml) and four (60 ml) times respectively. There was a stepwise increase in oxalate concentrations associated with increased brewing times (P< 0.001) with oxalate contents ranging from 4.4 mg/240 ml for the 5 min to 6.3 mg/240 ml for 60 min brewing times, respectively. There were significant differences between the mean oxalate content of different dilutions after brewing for 15, 30 and 60 minutes (P< 0.001). The oxalate content of Iranian consumed black tea after different brewing times and different dilution was below the recommended levels. Therefore, it seems that consumption of black tea several times per day would not pose significant health risk in kidney stone patients and susceptible individuals.

Oxalate Content of Different Drinkable Dilutions of Tea Infusions after Different Brewing Times

PubMed Central

Lotfi Yagin, Neda; Mahdavi, Reza; Nikniaz, Zeinab

2012-01-01

Background: The aims of this study were to determine the effect of different brewing times and diluting on oxalate content of loose-packed black teas consumed in Tabriz, Iran. Methods: The oxalate content of black teas after brewing for 5, 10, 15, 30, 60 minutes was measured in triplicate by enzymatic assay. In order to attain the most acceptable dilution of tea infusions, tea samples which were brewed for 15, 30 and 60 minutes were diluted two (120 ml), three (80 ml) and four (60 ml) times respectively. Results: There was a stepwise increase in oxalate concentrations associated with increased brewing times (P< 0.001) with oxalate contents ranging from 4.4 mg/240 ml for the 5 min to 6.3 mg/240 ml for 60 min brewing times, respectively. There were significant differences between the mean oxalate content of different dilutions after brewing for 15, 30 and 60 minutes (P< 0.001). Conclusion: The oxalate content of Iranian consumed black tea after different brewing times and different dilution was below the recommended levels. Therefore, it seems that consumption of black tea several times per day would not pose significant health risk in kidney stone patients and susceptible individuals. PMID:24688937

Doing More with Less? Toward Increasing the Resolution of Protistan Grazing-rate Measurements.

NASA Astrophysics Data System (ADS)

Morison, F.; Menden-Deuer, S.

2016-02-01

The dilution method is the standard protocol to quantify phytoplankton grazing-mortality rates and has been key in developing an understanding of protistan grazing impact on ocean primary production. Although the method's extensive use has facilitated the acquisition of a global dataset, its laborious application hinders the sampling resolution needed to fill knowledge gaps remaining at the geographical, seasonal, and vertical scales, and of the effects of climate-related factors influencing grazing magnitude. Here we present a rigorous assessment of an abbreviated method known as the 2-point. We analyzed unpublished results from 77 dilution experiments performed using a series of up to 5 dilutions under a wide range of chlorophyll concentrations and temperatures. We quantified the difference between estimates of both phytoplankton growth and grazing-mortality obtained based on the full dilution series and those obtained when the number of dilutions was reduced to 2. We considered the effect of non-linearity and chlorophyll concentration, and generated quantified estimates of trade-offs when choosing the fraction of seawater in the diluted treatment. Ultimately, we provide an assessment of the reliability of the 2-point method and recommendations on how to apply it.

Comparison of Agar Dilution, Disk Diffusion, MicroScan, and Vitek Antimicrobial Susceptibility Testing Methods to Broth Microdilution for Detection of Fluoroquinolone-Resistant Isolates of the Family Enterobacteriaceae

PubMed Central

Steward, Christine D.; Stocker, Sheila A.; Swenson, Jana M.; O’Hara, Caroline M.; Edwards, Jonathan R.; Gaynes, Robert P.; McGowan, John E.; Tenover, Fred C.

1999-01-01

Fluoroquinolone resistance appears to be increasing in many species of bacteria, particularly in those causing nosocomial infections. However, the accuracy of some antimicrobial susceptibility testing methods for detecting fluoroquinolone resistance remains uncertain. Therefore, we compared the accuracy of the results of agar dilution, disk diffusion, MicroScan Walk Away Neg Combo 15 conventional panels, and Vitek GNS-F7 cards to the accuracy of the results of the broth microdilution reference method for detection of ciprofloxacin and ofloxacin resistance in 195 clinical isolates of the family Enterobacteriaceae collected from six U.S. hospitals for a national surveillance project (Project ICARE [Intensive Care Antimicrobial Resistance Epidemiology]). For ciprofloxacin, very major error rates were 0% (disk diffusion and MicroScan), 0.9% (agar dilution), and 2.7% (Vitek), while major error rates ranged from 0% (agar dilution) to 3.7% (MicroScan and Vitek). Minor error rates ranged from 12.3% (agar dilution) to 20.5% (MicroScan). For ofloxacin, no very major errors were observed, and major errors were noted only with MicroScan (3.7% major error rate). Minor error rates ranged from 8.2% (agar dilution) to 18.5% (Vitek). Minor errors for all methods were substantially reduced when results with MICs within ±1 dilution of the broth microdilution reference MIC were excluded from analysis. However, the high number of minor errors by all test systems remains a concern. PMID:9986809

Effects of in vitro hemodilution with crystalloids, colloids, and plasma on canine whole blood coagulation as determined by kaolin-activated thromboelastography.

PubMed

Morris, Bari R; deLaforcade, Armelle; Lee, Joyce; Palmisano, Joseph; Meola, Dawn; Rozanski, Elizabeth

2016-01-01

To investigate the effects of in vitro hemodilution with lactated Ringers solution (LRS), hetastarch (HES), and fresh frozen plasma (FFP) on whole blood coagulation in dogs as assessed by kaolin-activated thromboelastography. In vitro experimental study. University teaching hospital. Six healthy client-owned dogs. Whole blood was collected and diluted in vitro at a 33% and 67% dilution with either LRS, HES, or FFP. Kaolin-activated thromboelastography was performed on each sample as well as a control. Thromboelastographic parameters R (min), alpha (deg), K (min), and MA (mm) were measured and compared to the sample control for each dilution using mixed model methodology. Prolongation in coagulation times were seen at both dilutions with LRS and HES. There was no significant difference in R times at the 33% dilution, but R time was significantly prolonged at the 67% dilution with HES (P = 0.004). MA was significantly decreased for LRS at both dilutions (P = 0.013, P < 0.001) and more profoundly decreased for HES (P < 0.001, P = 0.006). No significant difference in any parameter was found for FFP. In vitro hemodilution of whole blood with both LRS and HES but not FFP resulted in significant effects on coagulation with HES having a more profound effect. In vivo evaluation of changes in coagulation with various resuscitation fluids is warranted and may be clinically relevant. © Veterinary Emergency and Critical Care Society 2015.

Effects of dilution on dissolved oxygen depletion and microbial populations in the biochemical oxygen demand determination.

PubMed

Seo, Kyo Seong; Chang, Ho Nam; Park, Joong Kon; Choo, Kwang-Ho

2007-09-01

The biochemical oxygen demand (BOD) value is still a key parameter that can determine the level of organics, particularly the content of biodegradable organics in water. In this work, the effects of sample dilution, which should be done inevitably to get appropriate dissolved oxygen (DO) depletion, on the measurement of 5-day BOD (BOD(5)), was investigated with and without seeding using natural and synthetic water. The dilution effects were also evaluated for water samples taken in different seasons such as summer and winter because water temperature can cause a change in the types of microbial species, thus leading to different oxygen depletion profiles during BOD testing. The predation phenomenon between microbial cells was found to be dependent on the inorganic nutrients and carbon sources, showing a change in cell populations according to cell size after 5-day incubation. The dilution of water samples for BOD determination was linked to changes in the environment for microbial growth such as nutrition. The predation phenomenon between microbial cells was more important with less dilution. BOD(5) increased with the specific amount of inorganic nutrient per microbial mass when the natural water was diluted. When seeding was done for synthetic water samples, the seed volume also affected BOD due to the rate of organic uptake by microbes. BOD(5) increased with the specific bacterial population per organic source supplied at the beginning of BOD measurement. For more accurate BOD measurements, specific guidelines on dilution should be established.

Comparison of the antibacterial activity of an ozonated oil with chlorhexidine digluconate and povidone-iodine. A disk diffusion test.

PubMed

Montevecchi, Marco; Dorigo, Antonio; Cricca, Monica; Checchi, Luigi

2013-07-01

Ozonated oils are antiseptics obtained from the chemical reaction between ozone and unsaturated fatty acids of vegetable oils. The aim of this study was to investigate the antimicrobial effectiveness of a commercially available ozonated oil (O3-Oil), in comparison with 0.2% chlorhexidine digluconate (CHX) and 10% povidone-iodine (PVP-I) through a disk diffusion test. For each antiseptic a series of two-fold dilutions was made, obtaining seven dilutions: 1:2, 1:4, 1:8, 1:16, 1:32, 1:64 and 1:128. The undiluted antiseptics and the seven dilutions were tested against two freeze-dried bacterial strains: Staphylococcus aureus (Sa) and Porphyromonas gingivalis (Pg). O3-Oil showed significantly greater diameters of growth inhibition (p<0.01) than CHX and PVP-I in all dilutions for both tested strains. CHX lost any antibacterial efficacy when diluted more than 1:32. At the highest dilution, the diameters of growth inhibition against Sa were 20.67±0.58 mm and 15.33±0.58 mm, for O3-Oil and PVP-I, respectively. At the same dilution, the diameters of growth inhibition against Pg were: 19.00 mm for O3-Oil and 13.67±0.58 mm for PVP-I. The promising results obtained for the O3-Oil, against the opportunistic Sa, and Pg, one of the main periodontal pathogens, suggest its potential applicability for periodontal treatment. Further preclinical and clinical investigations are warranted.

Body composition among Sri Lankan infants by 18*O dilution method and the validity of anthropometric equations to predict body fat against 18*O dilution

USDA-ARS?s Scientific Manuscript database

Body composition indicators provide a better guidance for growth and nutritional status of the infants. This study was designed to (1) measure the body composition of the Sri Lankan infants using a reference method, the 18*O dilution method; (2) calculate the body fat content of the infants using pu...

Methods for deoxygenating biomass-derived pyrolysis oil

DOEpatents

Brandvold, Timothy A.

2015-07-14

Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method comprising the steps of diluting the biomass-derived pyrolysis oil with a phenolic-containing diluent to form a diluted pyoil-phenolic feed is provided. The diluted pyoil-phenolic feed is contacted with a deoxygenating catalyst in the presence of hydrogen at hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

Experimental Measurements for the Effect of Dilution Procedure in Blood Esterases as Animals Biomarker for Exposure to OP Compounds

PubMed Central

Abass, Kasim Sakran

2014-01-01

Organophosphate compounds can bind to carboxylesterase, which may lower the concentration of organophosphate pesticides at the target site enzyme, cholinesterase. It is unclear from the literature whether it is the carboxylesterase affinity for the organophosphate and/or the number of carboxylesterase molecules that is the dominant factor in determining the protective potential of carboxylesterase. The fundamental dilutions and kinetic effects of esterase enzyme are still poorly understood. This study aims to confirm and extend our current knowledge about the effects of dilutions on esterases activities in the blood for birds with respect to protecting the enzyme from organophosphate inhibition. There was significantly higher esterases activities in dilution 1 : 10 in the all blood samples from quail, duck, and chick compared to other dilutions (1 : 5, 1 : 15, 1 : 20, and 1 : 25) in all cases. Furthermore, our results also pointed to the importance of estimating different dilutions effects prior to using in birds as biomarker tools of environmental exposure. Concentration-inhibition curves were determined for the inhibitor in the presence of dilutions 1 : 5, 1 : 10, plus 1 : 15 (to stimulate carboxylesterase). Point estimates (concentrations calculated to produce 20, 50, and 80% inhibition) were compared across conditions and served as a measure of esterase-mediated detoxification. Results with well-known inhibitors (malathion) were in agreement with the literature, serving to support the use of this assay. Among the thiol-esters dilution 1 : 5 was observed to have the highest specificity constant (k cat/K m), and the K m and k cat values were 176 μM and 16,765 s−1, respectively, for S-phenyl thioacetate ester, while detected in dilution 1 : 15 was the lowest specificity constant (k cat/K m), and the K m and k cat values were 943 μM and 1154 s−1, respectively, for acetylthiocholine iodide ester. PMID:24864243

An Investigation Into the Effects of In Vitro Dilution With Different Colloid Resuscitation Fluids on Clot Microstructure Formation.

PubMed

Lawrence, Matthew James; Marsden, Nick; Kaczynski, Jakub; Davies, Gareth; Davies, Nia; Hawkins, Karl; Perumal, Sounder; Brown, Martin Rowan; Morris, Keith; Davidson, Simon J; Williams, Phylip Rhodri; Evans, Phillip Adrian

2016-11-01

Balancing the beneficial effects of resuscitation fluids against their detrimental effect on hemostasis is an important clinical issue. We aim to compare the in vitro effects of 3 different colloid resuscitation fluids (4.5% albumin, hydroxyethyl starch [Voluven 6%], and gelatin [Geloplasma]) on clot microstructure formation using a novel viscoelastic technique, the gel point. This novel hemorheologic technique measures the biophysical properties of the clot and provides an assessment of clot microstructure from its viscoelastic properties. Importantly, in contrast to many assays in routine clinical use, the measurement is performed using unadulterated whole blood in a near-patient setting and provides rapid assessment of coagulation. We hypothesized that different colloids will have a lesser or greater detrimental effect on clot microstructure formation when compared against each other. Healthy volunteers were recruited into the study (n = 104), and a 20-mL sample of whole blood was obtained. Each volunteer was assigned to 1 of the 3 fluids, and the sample was diluted to 1 of 5 different dilutions (baseline, 10%, 20%, 40%, and 60%). The blood was tested using the gel point technique, which measures clot mechanical strength and quantifies clot microstructure (df) at the incipient stages of fibrin formation. df and clot mechanical strength decrease with progressive dilution for all 3 fluids. A significant reduction in df from baseline was recorded at dilutions of 20% for albumin (P < .0001), 40% for starch (P < .0001), and 60% for gelatin (P < .0001). We also observed significant differences, in terms of df, when comparing the different types of colloid (P < .0001). We found that albumin dilution produced the largest changes in clot microstructure, providing the lowest values of df (= 1.41 ± 0.061 at 60% dilution) compared with starch (1.52 ± 0.081) and gelatin (1.58 ± 0.063). We show that dilution with all 3 fluids has a significant effect on coagulation at even relatively low dilution volumes (20% and 40%). Furthermore, we quantify, using a novel viscoelastic technique, how the physiochemical properties of the 3 colloids exert individual changes on clot microstructure.

Single-molecule dilution and multiple displacement amplification for molecular haplotyping.

PubMed

Paul, Philip; Apgar, Josh

2005-04-01

Separate haploid analysis is frequently required for heterozygous genotyping to resolve phase ambiguity or confirm allelic sequence. We demonstrate a technique of single-molecule dilution followed by multiple strand displacement amplification to haplotype polymorphic alleles. Dilution of DNA to haploid equivalency, or a single molecule, is a simple method for separating di-allelic DNA. Strand displacement amplification is a robust method for non-specific DNA expansion that employs random hexamers and phage polymerase Phi29 for double-stranded DNA displacement and primer extension, resulting in high processivity and exceptional product length. Single-molecule dilution was followed by strand displacement amplification to expand separated alleles to microgram quantities of DNA for more efficient haplotype analysis of heterozygous genes.

Progressing batch hydrolysis process

DOEpatents

Wright, John D.

1986-01-01

A progressive batch hydrolysis process for producing sugar from a lignocellulosic feedstock, comprising passing a stream of dilute acid serially through a plurality of percolation hydrolysis reactors charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the cellulose component of the feedstock to glucose; cooling said dilute acid stream containing glucose, after exiting the last percolation hydrolysis reactor, then feeding said dilute acid stream serially through a plurality of prehydrolysis percolation reactors, charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the hemicellulose component of said feedstock to glucose; and cooling the dilute acid stream containing glucose after it exits the last prehydrolysis reactor.

Methods and apparatuses for deoxygenating biomass-derived pyrolysis oil

DOEpatents

Baird, Lance Awender; Brandvold, Timothy A.

2015-10-20

Embodiments of methods and apparatuses for deoxygenating a biomass-derived pyrolysis oil are provided. In one example, a method comprises the steps of separating a low-oxygen biomass-derived pyrolysis oil effluent into a low-oxygen-pyoil organic phase stream and an aqueous phase stream. Phenolic compounds are removed from the aqueous phase stream to form a phenolic-rich diluent recycle stream. A biomass-derived pyrolysis oil stream is diluted and heated with the phenolic-rich diluent recycle stream to form a heated diluted pyoil feed stream. The heated diluted pyoil feed stream is contacted with a deoxygenating catalyst in the presence of hydrogen to deoxygenate the heated diluted pyoil feed stream.

Identification of Key Odorants in Withering-Flavored Green Tea by Aroma Extract Dilution Analysis

NASA Astrophysics Data System (ADS)

Mizukami, Yuzo; Yamaguchi, Yuichi

This research aims to identify key odorants in withering-flavored green tea. Application of the aroma extract dilution analysis using the volatile fraction of green tea and withering-flavored green tea revealed 25 and 35 odor-active peaks with the flavor dilution factors of≥4, respectively. 4-mercapto-4-methylpentan-2-one, (E)-2-nonenal, linalool, (E,Z)-2,6-nonadienal and 3-methylnonane-2,4-dione were key odorants in green tea with the flavor dilution factor of≥16. As well as these 5 odorants, 1-octen-3-one, β-damascenone, geraniol, β-ionone, (Z)-methyljasmonate, indole and coumarine contributed to the withering flavor of green tea.

Interventions in Early Mathematics: Avoiding Pollution and Dilution.

PubMed

Sarama, Julie; Clements, Douglas H

2017-01-01

Although specific interventions in early mathematics have been successful, few have been brought to scale successfully, especially across the challenging diversity of populations and contexts in the early childhood system in the United States. In this chapter, we analyze a theoretically based scale-up model for early mathematics that was designed to avoid the pollution and dilution that often plagues efforts to achieve broad success. We elaborate the theoretical framework by noting the junctures that are susceptible to dilution or pollution. Then we expatiate the model's guidelines to describe specifically how they were designed and implemented to mitigate pollution and dilution. Finally, we provide evidence regarding the success of these efforts. © 2017 Elsevier Inc. All rights reserved.

Biodiesel Impact on Engine Lubricant Dilution During Active Regeneration of Aftertreatment Systems

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

He, X.; Williams, A.; Christensen, E.

Experiments were conducted with ultra low sulfur diesel (ULSD) and 20% biodiesel blends (B20) to compare lube oil dilution levels and lubricant properties for systems using late in-cylinder fuel injection for aftertreatment regeneration. Lube oil dilution was measured by gas chromatography (GC) following ASTM method D3524 to measure diesel content, by Fourier transform infrared (FTIR) spectrometry following a modified ASTM method D7371 to measure biodiesel content, and by a newly developed back-flush GC method that simultaneously measures both diesel and biodiesel. Heavy-duty (HD) engine testing was conducted on a 2008 6.7L Cummins ISB equipped with a diesel oxidation catalyst (DOC)more » and diesel particle filter (DPF). Stage one of engine testing consisted of 10 consecutive repeats of a forced DPF regeneration event. This continuous operation with late in-cylinder fuel injection served as a method to accelerate lube-oil dilution. Stage two consisted of 16 hours of normal engine operation over a transient test cycle, which created an opportunity for any accumulated fuel in the oil sump to evaporate. Light duty (LD) vehicle testing was conducted on a 2010 VW Jetta equipped with DOC, DPF and a NOx storage catalyst (NSC). Vehicle testing comprised approximately 4,000 miles of operation on a mileage-accumulation dynamometer (MAD) using the U.S. Environmental Protection Agency's Highway Fuel Economy Cycle because of the relatively low engine oil and exhaust temperatures, and high DPF regeneration frequency of this cycle relative to other cycles examined. Comparison of the lube oil dilution analysis methods suggests that D3524 does not measure dilution by biodiesel. The new back-flush GC method provided analysis for both diesel and biodiesel, in a shorter time and with lower detection limit. Thus all lube oil dilution results in this paper are based on this method. Analysis of the HD lube-oil samples showed only 1.5% to 1.6% fuel dilution for both fuels during continuous operation under DPF regeneration events. During the second stage of HD testing, the ULSD lube-oil dilution levels fell from 1.5% to 0.8%, while for B20, lube-oil dilution levels fell from 1.6% to 1.0%, but the fuel in the oil was 36% biodiesel. For the LD vehicle tests, the frequency of DPF regeneration events was observed to be the same for both ULSD and B20. No significant difference between the two fuels' estimated soot loading was detected by the engine control unit (ECU), although a 23% slower rate of increase in differential pressure across DPF was observed with B20. It appears that the ECU estimated soot loading is based on the engine map, not taking advantage of the lower engine-out particulate matter from the use of biodiesel. After 4,000 miles of LD vehicle operation with ULSD, fuel dilution in the lube-oil samples showed total dilution levels of 4.1% diesel. After 4,000 miles of operation with B20, total fuel in oil dilution levels were 6.7% consisting of 3.6% diesel fuel and 3.1% biodiesel. Extrapolation to the 10,000-mile oil drain interval with B20 suggests that the total fuel content in the oil could reach 12%, compared to 5% for operation on ULSD. Analysis of the oil samples also included measurement of total acid number, total base number, viscosity, soot, metals and wear scar; however, little difference in these parameters was noted.« less

Effect of α-Amylase, Papain, and Spermfluid treatments on viscosity and semen parameters of dromedary camel ejaculates.

PubMed

Monaco, Davide; Fatnassi, Meriem; Padalino, Barbara; Hammadi, Mohamed; Khorchani, Touhami; Lacalandra, Giovanni Michele

2016-04-01

Ejaculates from five clinically healthy dromedary camels (Camelus dromedarius) were used to evaluate the effects of different enzymatic treatments (Amylase, Papain, Spermfluid) on liquefaction and seminal parameters. After collection, ejaculates were divided into 5 aliquots: (1) kept undiluted (control); or diluted 1:1 with: (2) Tris-Citrate-Fructose (TCF), (3) TCF containing Amylase, (4) TCF containing Papain or (5) Spermfluid containing Bromelain. At 120 min after dilution, each aliquot was evaluated, at 20-min intervals, for viscosity, motility, viability and agglutination. Only the aliquots diluted with TCF containing Papain underwent complete liquefaction. Sperm motility decreased significantly during the observation times, except for the samples diluted with Spermfluid (P=0.005). Diluted samples showed different levels of agglutination, with the lowest being observed in the control and the highest in the Papain-treated samples. The viscosity of dromedary camel ejaculates could be effectively reduced by using the proteolytic enzyme Papain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pseudo-lignin Formation during Dilute Acid Pretreatment for Cellulosic Ethanol

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

Meng, Xianzhi; Ragauskas, Arthur J.

Dilute acid-based pretreatment represents one of the most important pretreatment technologies to reduce biomass recalcitrance and it has been successfully applied to a wide range of feedstocks. During this type of pretreatment, the relative lignin content usually increases partially due to the loss of carbohydrates. More importantly, it has been reported that the increase of lignin content after dilute acid pretreatment is mainly due to the formation of pseudo-lignin. Furthermore, the exact reaction mechanisms leading to the formation of pseudo-lignin is still under investigation. However, it has been proposed that rearrangement of hydroxymethylfurfural (HMF) or furfural can produce aromatic typemore » of compounds which can further undergo polymerization reactions to from a lignin-like polyphenolic structures termed as pseudo-lignin. Likewise, this mini-review mainly covers recent advances in understanding the fundamentals of pseudo-lignin formation during dilute acid pretreatment, the impact of its formation on enzymatic hydrolysis, and how to suppress its formation during dilute acid pretreatment.« less

Quantitation of Rotundone in Grapefruit (Citrus paradisi) Peel and Juice by Stable Isotope Dilution Assay.

PubMed

Nakanishi, Akira; Fukushima, Yusuke; Miyazawa, Norio; Yoshikawa, Keisuke; Maeda, Tomoko; Kurobayashi, Yoshiko

2017-06-21

Aroma extract dilution analyses of the aromas of peels and juices of white and pink grapefruits revealed that rotundone, responsible for peppery, spicy, and woody odors, was detected for the first time at high flavor dilution factors of 256-1024. In both juices, rotundone was detected at the highest flavor dilution factor of 1024. Rotundone in grapefruits was quantitated by a stable isotope dilution assay with a newly synthesized deuterium-labeled internal standard, rotundone-d 2,3 : its levels were 2180 and 1920 ng/kg in white and pink grapefruit peels and 29.6 and 49.8 ng/kg in white and pink grapefruit juices, respectively. On the basis of these results, sensory analysis was performed to assess the effects of rotundone on a white grapefruit juice aroma reconstitute. This sensory analysis revealed that rotundone does not impart a woody odor or affect any of the existing attributes, but increases various attributes, thus confirming that rotundone is indispensable for the aroma of grapefruit juice.

Unanticipated error in HbA(1c) measurement on the HLC-723 G7 analyzer.

PubMed

van den Ouweland, Johannes M W; de Keijzer, Marinus H; van Daal, Henny

2010-04-01

Investigation of falsely elevated HbA(1c) measurements on the HLC-723 G7 analyser. Comparison of HbA(1c) in blood samples that were diluted either in hemolysis reagent or water. HbA(1c) results became falsely elevated when samples were diluted in hemolysis reagent, but not in water. QC-procedures failed to detect this error as calibrator and QC samples were manually diluted in water, according to manufacturer's instructions, whereas patient samples were automatically diluted using hemolysing reagent. After replacement of the instruments' sample-loop and rotor seal comparable HbA(1c) results were obtained, irrespective of dilution with hemolysing reagent or water. This case illustrates the importance of treating calibrator and QC materials similar to routine patient samples in order to prevent unnoticed drift in patient HbA(1c) results. Copyright 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Determination of buildup and dilution of wastewater effluent in shellfish growing waters through a modified application of super-position.

PubMed

Goblick, Gregory N; Ao, Yaping; Anbarchian, Julie M; Calci, Kevin R

2017-02-15

Since 1925, dilution analysis has been used to minimize pathogenic impacts to bivalve molluscan shellfish growing areas from treated wastewater effluent in the National Shellfish Sanitation Program (NSSP). For over twenty five years, the U.S. Food and Drug Administration (FDA) has recommended a minimum of 1000:1 dilution of effluent within prohibited closure zones established around wastewater treatment plant (WWTP) discharges. During May 2010, using recent technologies, a hydrographic dye study was conducted in conjunction with a pathogen bioaccumulation study in shellfish adjacent to a WWTP discharge in Yarmouth, ME. For the first time an improved method of the super-position principle was used to determine the buildup of dye tagged sewage effluent and steady state dilution in tidal waters. Results of the improved method of dilution analysis illustrate an economical, reliable and more accurate and manageable approach for estimating the buildup and steady state pollutant conditions in coastal and estuarine waters. Published by Elsevier Ltd.

Field measurements and modeling of dilution in the wake of a US navy frigate.

PubMed

Katz, C N; Chadwick, D B; Rohr, J; Hyman, M; Ondercin, D

2003-08-01

A field measurement and computer modeling effort was made to assess the dilution field of pulped waste materials discharged into the wake of a US Navy frigate. Pulped paper and fluorescein dye were discharged from the frigate's pulper at known rates. The subsequent particle and dye concentration field was then measured throughout the wake by a following vessel using multiple independent measures. Minimum dilution of the pulped paper reached 3.2 x 10(5) within 1900 m behind the frigate, or about 8 min after discharge. Independent measures typically agreed within 25% of one another and within 20% of model predictions. Minimum dilution of dye reached 2.3 x 10(5) at a down-wake distance of approximately 3500 m, or roughly 15 min. Comparison to model measurements were again within 20%. The field test was not only successful at characterizing wake dilution under one set of at-sea conditions, but was successful at validating the computer model used for assessing a wide range of ships and conditions.

Dilution effect on the formation of amorphous phase in the laser cladded Ni-Fe-B-Si-Nb coatings after laser remelting process

NASA Astrophysics Data System (ADS)

Li, Ruifeng; Li, Zhuguo; Huang, Jian; Zhu, Yanyan

2012-08-01

Ni-Fe-B-Si-Nb coatings have been deposited on mild steel substrates using high power diode laser cladding. Scanning laser beam at high speeds was followed to remelt the surface of the coatings. Different laser cladding powers in the range of 700-1000 W were used to obtain various dilution ratios in the coating. The dilution effect on the chemical characterization, phase composition and microstructure is analyzed by energy dispersive spectroscopy, X-ray diffraction and scanning-electron microscopy. The microhardness distribution of the coatings after laser processing is also measured. The results reveal that Ni-based amorphous composite coatings have successfully been fabricated on mild steel substrate at low dilution ratio when the cladding power was 700 W, 800 W and 900 W. While at high laser power of 1000 W, no amorphous phase was found. The coatings with low dilution ratio exhibit the highest microhardness of 1200 HV0.5 due to their largest volume fraction of amorphous phase.

A new gas dilution method for measuring body volume.

PubMed Central

Nagao, N; Tamaki, K; Kuchiki, T; Nagao, M

1995-01-01

This study was designed to examine the validity of a new gas dilution method (GD) for measuring human body volume and to compare its accuracy with the results obtained by the underwater weighing method (UW). We measured the volume of plastic bottles and 16 subjects (including two females), aged 18-42 years with each method. For the bottles, the volume measured by hydrostatic weighing was correlated highly (r = 1.000) with that measured by the new gas dilution method. For the subjects, the body volume determined by the two methods was significantly correlated (r = 0.998). However, the subject's volume measured by the gas dilution method was significantly larger than that by underwater weighing method. There was significant correlation (r = 0.806) between GD volume-UW volume and the body mass index (BMI), so that UW volume could be predicted from GD volume and BMI. It can be concluded that the new gas dilution method offers promising possibilities for future research in the population who cannot submerge underwater. PMID:7551760

One-Shot Coherence Dilution.

PubMed

Zhao, Qi; Liu, Yunchao; Yuan, Xiao; Chitambar, Eric; Ma, Xiongfeng

2018-02-16

Manipulation and quantification of quantum resources are fundamental problems in quantum physics. In the asymptotic limit, coherence distillation and dilution have been proposed by manipulating infinite identical copies of states. In the nonasymptotic setting, finite data-size effects emerge, and the practically relevant problem of coherence manipulation using finite resources has been left open. This Letter establishes the one-shot theory of coherence dilution, which involves converting maximally coherent states into an arbitrary quantum state using maximally incoherent operations, dephasing-covariant incoherent operations, incoherent operations, or strictly incoherent operations. We introduce several coherence monotones with concrete operational interpretations that estimate the one-shot coherence cost-the minimum amount of maximally coherent states needed for faithful coherence dilution. Furthermore, we derive the asymptotic coherence dilution results with maximally incoherent operations, incoherent operations, and strictly incoherent operations as special cases. Our result can be applied in the analyses of quantum information processing tasks that exploit coherence as resources, such as quantum key distribution and random number generation.

Simultaneous treatment of food-waste recycling wastewater and cultivation of Tetraselmis suecica for biodiesel production.

PubMed

Heo, Sung-Woon; Ryu, Byung-Gon; Nam, Kibok; Kim, Woong; Yang, Ji-Won

2015-07-01

There is an increasing interest in the use of cultivated microalgae to simultaneously produce biodiesel and remove nutrients from various wastewaters. For this purpose, Tetraselmis suecica was cultivated in flasks and fermenters using diluted food-waste recycling wastewater (FRW). The effect of FRW dilution on T. suecica growth and nutrient removal was initially tested in flasks. The maximal microalgal concentration after 14 days was in medium with a twofold dilution (28.3 × 10(6) cells/mL) and a fivefold dilution (25.5 × 10(6) cells/mL). When fivefold diluted medium was used in fermenters, the final dry cell weight of T. suecica was 2.0 g/L. The removal efficiencies of ammonium and phosphate in the fermenters were 99.0 and 52.3%, respectively. In comparison with the results of previous studies, the growth data of T. suecica in the FRW medium indicate that microalgal cultivation system incorporating removal of nutrients in FRW is feasible at the field level.

Pseudo-lignin Formation during Dilute Acid Pretreatment for Cellulosic Ethanol

DOE PAGES

Meng, Xianzhi; Ragauskas, Arthur J.

2017-04-17

Dilute acid-based pretreatment represents one of the most important pretreatment technologies to reduce biomass recalcitrance and it has been successfully applied to a wide range of feedstocks. During this type of pretreatment, the relative lignin content usually increases partially due to the loss of carbohydrates. More importantly, it has been reported that the increase of lignin content after dilute acid pretreatment is mainly due to the formation of pseudo-lignin. Furthermore, the exact reaction mechanisms leading to the formation of pseudo-lignin is still under investigation. However, it has been proposed that rearrangement of hydroxymethylfurfural (HMF) or furfural can produce aromatic typemore » of compounds which can further undergo polymerization reactions to from a lignin-like polyphenolic structures termed as pseudo-lignin. Likewise, this mini-review mainly covers recent advances in understanding the fundamentals of pseudo-lignin formation during dilute acid pretreatment, the impact of its formation on enzymatic hydrolysis, and how to suppress its formation during dilute acid pretreatment.« less

Microstructures and mechanical properties of bonding layers between low carbon steel and alloy 625 processed by gas tungsten arc welding

NASA Astrophysics Data System (ADS)

Lou, Shuai; Lee, Seul Bi; Nam, Dae-Geun; Choi, Yoon Suk

2017-11-01

A filler metal wire, Alloy 625, was cladded on a plate of a low carbon streel, SS400, by gas tungsten arc welding, and the morphology of the weld bead and resulting dilution ratio were investigated under different welding parameter values (the input current, weld speed and wire feed speed). The wire feed speed was found to be most influential in controlling the dilution ratio of the weld bead, and seemed to limit the influence of other welding parameters. Two extreme welding conditions (with the minimum and maximum dilution ratios) were identified, and the corresponding microstructures, hardness and tensile properties near the bond line were compared between the two cases. The weld bead with the minimum dilution ratio showed superior hardness and tensile properties, while the formation lath martensite (due to relatively fast cooling) affected mechanical properties in the heat affected zone of the base metal with the maximum dilution ratio.

One-Shot Coherence Dilution

NASA Astrophysics Data System (ADS)

Zhao, Qi; Liu, Yunchao; Yuan, Xiao; Chitambar, Eric; Ma, Xiongfeng

2018-02-01

Manipulation and quantification of quantum resources are fundamental problems in quantum physics. In the asymptotic limit, coherence distillation and dilution have been proposed by manipulating infinite identical copies of states. In the nonasymptotic setting, finite data-size effects emerge, and the practically relevant problem of coherence manipulation using finite resources has been left open. This Letter establishes the one-shot theory of coherence dilution, which involves converting maximally coherent states into an arbitrary quantum state using maximally incoherent operations, dephasing-covariant incoherent operations, incoherent operations, or strictly incoherent operations. We introduce several coherence monotones with concrete operational interpretations that estimate the one-shot coherence cost—the minimum amount of maximally coherent states needed for faithful coherence dilution. Furthermore, we derive the asymptotic coherence dilution results with maximally incoherent operations, incoherent operations, and strictly incoherent operations as special cases. Our result can be applied in the analyses of quantum information processing tasks that exploit coherence as resources, such as quantum key distribution and random number generation.

REUSABLE ADSORBENTS FOR DILUTE SOLUTIONS SEPARATION. 6. BATCH AND CONTINUOUS REACTORS FOR ADSORPTION AND DEGRADATION OF 1,2-DICHLOROBENZENE FROM DILUTE WASTEWATER STREAMS USING TITANIA AS A PHOTOCATALYST. (R828598C753)

EPA Science Inventory

Two types of external lamp reactors were investigated for the titania catalyzed photodegradation of 1,2-dichlorobenzene (DCB) from a dilute water stream. The first one was a batch mixed slurry reactor and the second one was a semi-batch reactor with continuous feed recycle wit...

The effect of ultrasound on particle size, color, viscosity and polyphenol oxidase activity of diluted avocado puree.

PubMed

Bi, Xiufang; Hemar, Yacine; Balaban, Murat O; Liao, Xiaojun

2015-11-01

The effect of ultrasound treatment on particle size, color, viscosity, polyphenol oxidase (PPO) activity and microstructure in diluted avocado puree was investigated. The treatments were carried out at 20 kHz (375 W/cm(2)) for 0-10 min. The surface mean diameter (D[3,2]) was reduced to 13.44 μm from an original value of 52.31 μm by ultrasound after 1 min. A higher L(∗) value, ΔE value and lower a(∗) value was observed in ultrasound treated samples. The avocado puree dilution followed pseudoplastic flow behavior, and the viscosity of diluted avocado puree (at 100 s(-1)) after ultrasound treatment for 1 min was 6.0 and 74.4 times higher than the control samples for dilution levels of 1:2 and 1:9, respectively. PPO activity greatly increased under all treatment conditions. A maximum increase of 25.1%, 36.9% and 187.8% in PPO activity was found in samples with dilution ratios of 1:2, 1:5 and 1:9, respectively. The increase in viscosity and measured PPO activity might be related to the decrease in particle size. The microscopy images further confirmed that ultrasound treatment induced disruption of avocado puree structure. Copyright © 2015 Elsevier B.V. All rights reserved.

The effect of dilute acid pre-treatment process in bioethanol production from durian (Durio zibethinus) seeds waste

NASA Astrophysics Data System (ADS)

Ghazali, K. A.; Salleh, S. F.; Riayatsyah, T. M. I.; Aditiya, H. B.; Mahlia, T. M. I.

2016-03-01

Lignocellulosic biomass is one of the promising feedstocks for bioethanol production. The process starts from pre-treatment, hydrolysis, fermentation, distillation and finally obtaining the final product, ethanol. The efficiency of enzymatic hydrolysis of cellulosic biomass depends heavily on the effectiveness of the pre-treatment step which main function is to break the lignin structure of the biomass. This work aims to investigate the effects of dilute acid pre-treatment on the enzymatic hydrolysis of durian seeds waste to glucose and the subsequent bioethanol fermentation process. The yield of glucose from dilute acid pre-treated sample using 0.6% H2SO4 and 5% substrate concentration shows significant value of 23.4951 g/L. Combination of dilute acid pre-treatment and enzymatic hydrolysis using 150U of enzyme able to yield 50.0944 g/L of glucose content higher compared to normal pre-treated sample of 8.1093 g/L. Dilute acid pre-treatment sample also shows stable and efficient yeast activity during fermentation process with lowest glucose content at 2.9636 g/L compared to 14.7583g/L for normal pre-treated sample. Based on the result, it can be concluded that dilute acid pre-treatment increase the yield of ethanol from bioethanol production process.

[Responses of antioxidation system of Cynodon dactylon to recirculated landfill leachate irrigation].

PubMed

Wang, Ruyi; He, Pinjing; Shao, Liming; Zhang, Bin; Li, Guojian

2005-05-01

With pot experiment, this paper studied the membrane lipid peroxidation and the variations of antioxidation system in Cynodon dactylon under recirculated landfill leachate irrigation. The results showed that when irrigated with low dilution ratio (< 25%) leachate, the chlorophyll a/b ratio increased with increasing dilution ratio, membrane permeability and MDA and H2O2 contents were in adverse, and membrane lipid peroxidation was relatively weak. However, with the increasing leachate dilution ratio (> 25%), there existed an obvious negative fect on Cynodon dactylon, i.e., the chlorophyll a/b ratio decreased, while cell membrane permeability and MDA and H2O2 contents increased, which meant that the membrane lipid peroxidation was accelerated. The contents antioxidants AsA, GSH and Car also showed the similar trend, i.e., they increased with increasing leachate dilution ratio when irrigated with low dilution ratio leachate, but decreased under medium or high dilution ratio leachate irrigation. Among three test anti-oxidative enzymes, SOD and POD activities showed a similar change test antioxidants, and POD activity was more sensitive, while CAT activity was on the contrary. The contents test antioxidants and the activities of SOD and POD were negatively and significantly correlated to MDA content, indicating that they might play an important role in preventing Cynodon dactylon from cell membrane lipid peroxdation.

Mixed aqueous solutions as dilution media in the determination of residual solvents by static headspace gas chromatography.

PubMed

D'Autry, Ward; Zheng, Chao; Wolfs, Kris; Yarramraju, Sitaramaraju; Hoogmartens, Jos; Van Schepdael, Ann; Adams, Erwin

2011-06-01

Static headspace (HS) sampling has been commonly used to test for volatile organic chemicals, usually referred to as residual solvents (RS) in pharmaceuticals. If the sample is not soluble in water, organic solvents are used. However, these seriously reduce the sensitivity in the determination of some RS. Here, mixed aqueous dilution media (a mixture of water and an organic solvent like dimethyl formamide, dimethyl sulfoxide or dimethyl acetamide) were studied as alternative media for static HS-gas chromatographic analysis. Although it has been known that mixed aqueous dilution media can often improve sensitivity for many RS, this study used a systematic approach to investigate phase volumes and the organic content in the HS sampling media. Reference solutions using 18 different class 1, 2 and 3 RS were evaluated. The effect of salt addition was also studied in this work. A significant increase in the peak area was observed for all RS using mixed aqueous dilution media, when compared with organic solvents alone. Matrix effects related to the mixed aqueous dilution media were also investigated and reported. Repeatability and linearity obtained with mixed aqueous dilution media were found to be similar to those observed with pure organic solvents. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Continuous cultivation of bakers' yeast: change in cell composition at different dilution rates and effect of heat stress on trehalose level.

PubMed

Ertugay, N; Hamamci, H

1997-01-01

The cell composition of bakers' yeast in a continuous culture was determined for different dilution rates. Also, the cellular response to heat stress in terms of trehalose, RNA, glycogen and protein was determined at a specified dilution rate of 0.1/h. The amount of storage saccharides, trehalose and glycogen, was found to decrease whereas the amount of RNA and protein increased with increasing dilution rates. As the dilution rate was increased from 0.1 to 0.4/h at 0.05 intervals the steady-state trehalose content decreased from 33 to 8.6 mg/g biomass, and glycogen content from 150 to 93 mg/g biomass. On the other hand, the protein content increased from 420 to 530 mg/g biomass and the RNA content from 93 to 113 mg/g biomass. Heat stress was applied by increasing the medium temperature from 30 to 36, 38 or 40 degrees C at constant dilution rates. The highest amount of trehalose accumulation, 108 mg/g biomass, was achieved when heat stress at 38 degrees C was applied. The protein content, on the other hand, decreased from 350 to 325 mg/g biomass at the end of the experiment.

Oesophageal bioadhesion of sodium alginate suspensions: particle swelling and mucosal retention.

PubMed

Richardson, J Craig; Dettmar, Peter W; Hampson, Frank C; Melia, Colin D

2004-09-01

This paper describes a prospective bioadhesive liquid dosage form designed to specifically adhere to the oesophageal mucosa. It contains a swelling polymer, sodium alginate, suspended in a water-miscible vehicle and is activated by dilution with saliva to form an adherent layer of polymer on the mucosal surface. The swelling of alginate particles and the bioadhesion of 40% (w/w) sodium alginate suspensions were investigated in a range of vehicles: glycerol, propylene glycol, PEG 200 and PEG 400. Swelling of particles as a function of vehicle dilution with artificial saliva was quantified microscopically using 1,9-dimethyl methylene blue (DMMB) as a visualising agent. The minimum vehicle dilution to initiate swelling varied between vehicles: glycerol required 30% (w/w) dilution whereas PEG 400 required nearly 60% (w/w). Swelling commenced when the Hildebrand solubility parameter of the diluted vehicle was raised to 37 MPa(1/2). The bioadhesive properties of suspensions were examined by quantifying the amount of sodium alginate retained on oesophageal mucosa after washing in artificial saliva. Suspensions exhibited considerable mucoretention and strong correlations were obtained between mucosal retention, the minimum dilution to initiate swelling, and the vehicle Hildebrand solubility parameter. These relationships may allow predictive design of suspensions with specific mucoretentive properties, through judicious choice of vehicle characteristics.

New methods allowing the detection of protein aggregates

PubMed Central

Demeule, Barthélemy; Palais, Caroline; Machaidze, Gia; Gurny, Robert

2009-01-01

Aggregation compromises the safety and efficacy of therapeutic proteins. According to the manufacturer, the therapeutic immunoglobulin trastuzumab (Herceptin®) should be diluted in 0.9% sodium chloride before administration. Dilution in 5% dextrose solutions is prohibited. The reason for the interdiction is not mentioned in the Food and Drug Administration (FDA) documentation, but the European Medicines Agency (EMEA) Summary of Product Characteristics states that dilution of trastuzumab in dextrose solutions results in protein aggregation. In this paper, asymmetrical flow field-flow fractionation (FFF), fluorescence spectroscopy, fluorescence microscopy and transmission electron microscopy (TEM) have been used to characterize trastuzumab samples diluted in 0.9% sodium chloride, a stable infusion solution, as well as in 5% dextrose (a solution prone to aggregation). When trastuzumab samples were injected in the FFF channel using a standard separation method, no difference could be seen between trastuzumab diluted in sodium chloride and trastuzumab diluted in dextrose. However, during FFF measurements made with appropriate protocols, aggregates were detected in 5% dextrose. The parameters enabling the detection of reversible trastuzumab aggregates are described. Aggregates could also be documented by fluorescence microscopy and TEM. Fluorescence spectroscopy data were indicative of conformational changes consistent with increased aggregation and adsorption to surfaces. The analytical methods presented in this study were able to detect and characterize trastuzumab aggregates. PMID:20061815

A theoretical framework for modeling dilution enhancement of non-reactive solutes in heterogeneous porous media.

PubMed

de Barros, F P J; Fiori, A; Boso, F; Bellin, A

2015-01-01

Spatial heterogeneity of the hydraulic properties of geological porous formations leads to erratically shaped solute clouds, thus increasing the edge area of the solute body and augmenting the dilution rate. In this study, we provide a theoretical framework to quantify dilution of a non-reactive solute within a steady state flow as affected by the spatial variability of the hydraulic conductivity. Embracing the Lagrangian concentration framework, we obtain explicit semi-analytical expressions for the dilution index as a function of the structural parameters of the random hydraulic conductivity field, under the assumptions of uniform-in-the-average flow, small injection source and weak-to-mild heterogeneity. Results show how the dilution enhancement of the solute cloud is strongly dependent on both the statistical anisotropy ratio and the heterogeneity level of the porous medium. The explicit semi-analytical solution also captures the temporal evolution of the dilution rate; for the early- and late-time limits, the proposed solution recovers previous results from the literature, while at intermediate times it reflects the increasing interplay between large-scale advection and local-scale dispersion. The performance of the theoretical framework is verified with high resolution numerical results and successfully tested against the Cape Cod field data. Copyright © 2015 Elsevier B.V. All rights reserved.

Flux-related and Critical Dilution Indices: Quantitative Indicators of Mixing and Mixing-controlled Reactions in Heterogeneous Porous Media

NASA Astrophysics Data System (ADS)

Chiogna, G.; Cirpka, O. A.; Grathwohl, P.; Rolle, M.

2010-12-01

The correct quantification of mixing is of utmost importance for modeling reactive transport in porous media and, thereby assessing the fate and transport of contaminants in the subsurface. An appropriate measure of mixing in heterogeneous porous formations should correctly capture the effects on mixing intensity of various processes at different scales, such as local dispersion and the effect of mixing enhancement due to heterogeneities. In this work, we use the concept of the flux-related dilution index as a measure of transverse mixing. This quantity expresses the dilution of the mass flux of a tracer solution over the total discharge of the system and is particularly suited to address problems where a compound is continuously injected into the domain. We focus our attention on two-dimensional systems under steady-state flow conditions and investigate both conservative and reactive transport in both homogeneous and heterogeneous porous media at different scales. For mixing-controlled reactive systems, we introduce and illustrate the concept of the critical dilution index, which represents the amount of mixing required for complete degradation of a continuously emitted plume undergoing decay upon mixing with ambient water. We perform two-dimensional numerical experiments at bench and field scales in homogeneous and heterogeneous conductivity fields. These numerical simulations show that the flux-related dilution index quantifies mixing and that the concept of the critical dilution index is a useful measure to relate the mixing of conservative tracers to mixing-controlled turnover of reactive compounds. In the end we define an effective transverse dispersion coefficient which is able to capture the main characteristics of the physical mechanisms controlling reactive transport at the field scale. Furthermore we investigated the influence of compound specific local transverse dispersion coefficients on the flux related dilution index and on the critical dilution index.

Developments on drug discovery and on new therapeutics: highly diluted tinctures act as biological response modifiers.

PubMed

de Oliveira, Carolina C; Abud, Ana Paula R; de Oliveira, Simone M; Guimarães, Fernando de S F; de Andrade, Lucas F; Di Bernardi, Raffaello P; Coletto, Ediely L de O; Kuczera, Diogo; Da Lozzo, Eneida J; Gonçalves, Jenifer P; Trindade, Edvaldo da S; Buchi, Dorly de F

2011-10-26

In the search for new therapies novel drugs and medications are being discovered, developed and tested in laboratories. Highly diluted substances are intended to enhance immune system responses resulting in reduced frequency of various diseases, and often present no risk of serious side-effects due to its low toxicity. Over the past years our research group has been investigating the action of highly diluted substances and tinctures on cells from the immune system. We have developed and tested several highly diluted tinctures and here we describe the biological activity of M1, M2, and M8 both in vitro in immune cells from mice and human, and in vivo in mice. Cytotoxicity, cytokines released and NF-κB activation were determined after in vitro treatment. Cell viability, oxidative response, lipid peroxidation, bone marrow and lymph node cells immunophenotyping were accessed after mice in vivo treatment. None of the highly diluted tinctures tested were cytotoxic to macrophages or K562. Lipopolysaccharide (LPS)-stimulated macrophages treated with all highly diluted tinctures decreased tumour necrosis factor alpha (TNF-α) release and M1, and M8 decreased IFN-γ production. M1 has decreased NF-κB activity on TNF-α stimulated reporter cell line. In vivo treatment lead to a decrease in reactive oxygen species (ROS), nitric oxide (NO) production was increased by M1, and M8, and lipid peroxidation was induced by M1, and M2. All compounds enhanced the innate immunity, but M1 also augmented acquired immunity and M2 diminished B lymphocytes, responsible to acquired immunity. Based on the results presented here, these highly diluted tinctures were shown to modulate immune responses. Even though further investigation is needed there is an indication that these highly diluted tinctures could be used as therapeutic interventions in disorders where the immune system is compromised.

Enhanced Detection of Vibrio Cholerae in Oyster Homogenate Based on Centrifugal Removal of Inhibitory Agents

NASA Technical Reports Server (NTRS)

Alexander, Donita; DePaola, Angelo; Young, Ronald B.

1998-01-01

The disease cholera, caused by Vibrio cholerae, has been associated with consumption of contaminated seafood, including raw oysters. Detection of V. cholerae in foods typically involves blending the oysters, diluting the homogenate in alkaline peptone water (APW), overnight enrichment, and isolation on selective agar. Unfortunately, the oyster homogenate must be diluted to large volumes because lower dilutions inhibit the growth of V. cholerae. The goals of this study were to develop an alternative to large dilutions and to evaluate the basis for the inhibition observed in lower dilutions of oyster homogenates. Centrifugation of oyster homogenates at 10,000 x g for 15 min, followed by enrichment of the resulting pellet in APW, was found to eliminate the inhibition of V. cholerae growth. Inhibition appears not to be due to competing microflora but to a component(s) released when V. cholerae grows in the presence of oyster homogenate. The inhibitory component(s) kills the V. cholerae after the cell concentration reaches > 10(exp 8) cells/mL, rather than initially preventing their growth. The pH also declines from 8.0 to 5.5 during this period; however, the pH decline by itself appears not to cause V. cholerae death. Seven strains of V. cholerae (01 and non-01) and two strains of V. vulnificus were susceptible to the inhibitory agent(s). However, other Vibrio and non-Vibrio species tested were not inhibited by the oyster homogenates. Based on digestion of oyster homogenates with pronase, trypsin and lipase, the inhibitory reaction involves a protein(s). In a preliminary trial with oyster homogenate seeded with 1 cfu/g of V. cholerae, the modified centrifugation technique detected a slightly higher percentage of samples at a 1:10 dilution than the standard FDA Bacteriological Analytical Method (BAM) detected in uncentrifuged oyster homogenate at a 1:100 dilution. V. cholerae in seeded samples could also be detected more frequently by the modified centrifugation method than by PCR at a 1:10 dilution.

A mass-balance code for the quantitative interpretation of fluid column profiles in ground-water studies

NASA Astrophysics Data System (ADS)

Paillet, Frederick

2012-08-01

A simple mass-balance code allows effective modeling of conventional fluid column resistivity logs in dilution tests involving column replacement with either distilled water or dilute brine. Modeling a series of column profiles where the inflowing formation water introduces water quality interfaces propagating along the borehole gives effective estimates of the rate of borehole flow. Application of the dilution model yields estimates of borehole flow rates that agree with measurements made with the heat-pulse flowmeter under ambient and pumping conditions. Model dilution experiments are used to demonstrate how dilution logging can extend the range of borehole flow measurement at least an order of magnitude beyond that achieved with flowmeters. However, dilution logging has the same dynamic range limitation encountered with flowmeters because it is difficult to detect and characterize flow zones that contribute a small fraction of total flow when that contribution is superimposed on a larger flow. When the smaller contribution is located below the primary zone, ambient downflow may disguise the zone if pumping is not strong enough to reverse the outflow. This situation can be addressed by increased pumping. But this is likely to make the moveout of water quality interfaces too fast to measure in the upper part of the borehole, so that a combination of flowmeter and dilution method may be more appropriate. Numerical experiments show that the expected weak horizontal flow across the borehole at conductive zones would be almost impossible to recognize if any ambient vertical flow is present. In situations where natural water quality differences occur such as flowing boreholes or injection experiments, the simple mass-balance code can be used to quantitatively model the evolution of fluid column logs. Otherwise, dilution experiments can be combined with high-resolution flowmeter profiles to obtain results not attainable using either method alone.

Modulating prime molecular expressions and in vitro wound healing rate in keratinocyte (HaCaT) population under characteristic honey dilutions.

PubMed

Chaudhary, Amrita; Bag, Swarnendu; Mandal, Mousumi; Krishna Karri, Sri Phani; Barui, Ananya; Rajput, Monika; Banerjee, Provas; Sheet, Debdoot; Chatterjee, Jyotirmoy

2015-05-26

In traditional medicines honey is known for healing efficacy and vividly used as "Anupan" in Ayurvedic medicines appreciating roles in dilutions. Validating efficacy of physico-chemically characterized honey in dilutions, studies on in vitro wound healing and attainment of cellular confluence epithelial cells including expressions of cardinal genes is crucial. To evaluate effects of characterized honey in varied dilutions on cellular viability, in vitro wound healing and modulation of prime epithelial gene expressions. Six Indian honey-samples from different sources were physico-chemically characterized and optimal one was explored in dilutions (v/v%) through in vitro studies on human epithelial (HaCaT) cells for viability, wound healing and expressions of genes p63, E-cadherin, β-catenin, GnT-III and GnT-V. Studied honey samples (i.e. A-F) depicted range of pH (2-4), water (12.48-23.95), electrical conductivity (2.57-14.34), carbohydrate (68.73-98.65), protein (.316-5.36) and antioxidant potential. Though sample A and F showed physico-chemical proximity, but overall bio-impact of the earlier was better, thus studied in 8-.1% (v/v) dilution range. Four dilutions (.01, .04, .1, .25 v/v%) augmented cellular viability but in vitro wound healing was fastest (p<.05) under .1%. Such efficacy was further documented for p63 up-regulation by immunocytochemistry and mRNA studies. The E-cadherin and β-catenin mRNA-expressions were also up-regulated and their proteins were predominantly cytoplasmic. E-cadherin up-regulation was corroborative with down-regulation and up-regulation of GnT-III and GnT-V respectively. Present study illustrated efficacy of particular honey dilution (.1%) with characteristic free radical scavenging activity in facilitating cell proliferation and attainment of confluence towards faster wound healing and modulation of cardinal epithelial genes (viz. p63, E-cadherin, β-catenin, Gnt-III and V). Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Wheat and ultra high diluted gibberellic acid--further experiments and re-analysis of data.

PubMed

Endler, Peter Christian; Scherer-Pongratz, Waltraud; Lothaller, Harald; Stephen, Saundra

2015-10-01

Following studies (a) on wheat seedlings and ultra high diluted silver nitrate, and (b) on amphibians and an ultra high diluted hormone, (c) a bio-assay on wheat and extremely diluted gibberellic acid was standardized. This assay was intended to combine the easy-to-handle aspect of (a) and biologically interesting aspects of (b). The purpose of the data analysis presented here was to investigate the influence of an extreme dilution of gibberellic acid on wheat stalk length and to determine the influence of external factors on the experimental outcome. Grains of winter wheat (Triticum aestivum, Capo variety) were observed under the influence of extremely diluted gibberellic acid (10(-30)) prepared by stepwise dilution and agitation according to a protocol derived from homeopathy ('G30x'). Analogously prepared water was used for control ('W30x'). 16 experiments including 8000+8000 grains were performed by 9 researchers. Experiments that were performed between January and April showed inconsistent results, whereas most of the experiments performed between September and December showed shorter stalks in the G30x group. This was confirmed by correlation analysis (p<0.01). Thus winter/spring experiments and autumn experiments were analysed separately. When all 10 autumn experiments were pooled, mean stalk lengths (mm) were 48.3±21.4 for the verum group and 52.1±20.4 for control (mean±SD) at grain level (N=5000 per group) and ±5.3 and ±5.1 respectively at dish level. In other words, verum stalk length (92.67%) was 7.33% smaller than control stalk length (100%). The effect size is small when calculation is done on the basis of grains (d=0.18) but, due to the smaller SD at dish level, medium when done on the basis of dishes (d=0.73). The inhibiting effect was observed by 6 of the 6 researchers who performed the autumn experiments. The model may be useful for further research as there exists a theoretical justification due to previous studies with wheat and extremely diluted silver nitrate, as well as to previous studies with amphibians and diluted hormones, and its methods are well standardized. Data confirm the hypothesis that information can be stored in the test liquid, even at a dilution of the original substance beyond Avogadro's value; and that the wheat bio-assay is sensitive to such information. Copyright © 2015 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Can low-temperature thermoluminescence cast light on the nature of ultra-high dilutions?

PubMed

Rey, Louis

2007-07-01

Low-temperature thermoluminescence has been used in attempt to understand the particular structure of ultra high dilutions. Samples are activated by irradiation after freezing at the temperature of liquid nitrogen (77 degrees K). Experimental results show that, in the course of rewarming, the thermoluminescent glow is susbtantially different between dilutions of different substances. It is suggested that the dispersed gas phase might play a role in this process.

Partial desalination and concentration of glyphosate liquor by nanofiltration.

PubMed

Xie, Ming; Xu, Yanhua

2011-02-15

Partial desalination and concentration of glyphosate liquor by nanofiltration under different operation modes were investigated experimentally in this study. These operation modes were direct nanofiltration, diafiltration, dilute-diafiltration and interval washing-nanofiltration. The four different operation modes were evaluated and compared in terms of glyphosate recovery and NaCl removal. Diafiltration and dilute-diafiltration performed better than direct nanofiltration. The glyphosate loss was between 11.5% and 18.8% when the dilution factor varied from 0.4 to 0.8. Interval washing-nanofiltration alleviated the concentration polarization and membrane fouling to a certain extent. Dilute-diafiltration may be the best operation mode in terms of glyphosate recovery, salt removal and cost. Copyright © 2010 Elsevier B.V. All rights reserved.

Production and distribution of dilute species in semiconducting materials

DOEpatents

James, Ralph B.; Camarda, Giuseppe; Bolotnikov, Aleksey E.; Hossain, Anwar; Yang, Ge; Kim, Kihyun

2016-09-06

Technologies are described effective to implement systems and methods of producing a material. The methods comprise receiving a tertiary semiconductor sample with a dilute species. The sample has two ends. The first end of the sample includes a first concentration of the dilute species lower than a second concentration of the dilute species in the second end of the sample. The method further comprises heating the sample in a chamber. The chamber has a first zone and a second zone. The first zone having a first temperature higher than a second temperature in the second zone. The sample is orientated such that the first end is in the first zone and the second end is in the second zone.

Determination of the viscosity number of thermoplastics in dilute solution; polyamides (PA)

NASA Technical Reports Server (NTRS)

1985-01-01

This West German Standard presents a test used to determine the viscosity number of polyamides and copolyamides which are easily diluted in sulfuric acid, and for other polyamides which are less easily diluted in sulfuric acid, and which are diluted in m-cresol. As formic acid is often used in industry instead of sulfuric acid, this solvent is also presented as an alternative, however, sulfuric acid is preferred because of the thermodynamic solubility characteristics of the polyamides and the handling safety. In addition, it is shown which solvent should be used for each polyamide. Finally, determinations concerning the preparation of the samples are presented. Using the viscosity number, a determination of the molar mass of the polyamides is possible.

Cardiac output monitoring using indicator-dilution techniques: basics, limits, and perspectives.

PubMed

Reuter, Daniel A; Huang, Cecil; Edrich, Thomas; Shernan, Stanton K; Eltzschig, Holger K

2010-03-01

The ability to monitor cardiac output is one of the important cornerstones of hemodynamic assessment for managing critically ill patients at increased risk for developing cardiac complications, and in particular in patients with preexisting cardiovascular comorbidities. For >30 years, single-bolus thermodilution measurement through a pulmonary artery catheter for assessment of cardiac output has been widely accepted as the "clinical standard" for advanced hemodynamic monitoring. In this article, we review this clinical standard, along with current alternatives also based on the indicator-dilution technique, such as the transcardiopulmonary thermodilution and lithium dilution techniques. In this review, not only the underlying technical principles and the unique features but also the limitations of each application of indicator dilution are outlined.

Stable isotope dilution analysis of hydrologic samples by inductively coupled plasma mass spectrometry

USGS Publications Warehouse

Garbarino, John R.; Taylor, Howard E.

1987-01-01

Inductively coupled plasma mass spectrometry is employed in the determination of Ni, Cu, Sr, Cd, Ba, Ti, and Pb in nonsaline, natural water samples by stable isotope dilution analysis. Hydrologic samples were directly analyzed without any unusual pretreatment. Interference effects related to overlapping isobars, formation of metal oxide and multiply charged ions, and matrix composition were identified and suitable methods of correction evaluated. A comparability study snowed that single-element isotope dilution analysis was only marginally better than sequential multielement isotope dilution analysis. Accuracy and precision of the single-element method were determined on the basis of results obtained for standard reference materials. The instrumental technique was shown to be ideally suited for programs associated with certification of standard reference materials.

Mechanical properties of electron-beam-melted molybdenum and dilute molybdenum-rhenium alloys

NASA Technical Reports Server (NTRS)

Klopp, W. D.; Witzke, W. R.

1972-01-01

A study of molybdenum and three dilute molybdenum-rhenium alloys was undertaken to determine the effects of rhenium on the low temperature ductility and other mechanical properties of molybdenum. Alloys containing 3.9, 5.9, and 7.7 atomic percent rhenium exhibited lower ductile-brittle transition temperatures than did the unalloyed molybdenum. The maximum improvement in the annealed condition was observed for molybdenum - 7.7 rhenium, which had a ductile-brittle transition temperature approximately 200 C (360 F) lower than that for unalloyed molybdenum. Rhenium additions also increased the low and high temperature tensile strengths and the high temperature creep strength of molybdenum. The mechanical behavior of dilute molybdenum-rhenium alloys is similar to that observed for dilute tungsten-rhenium alloys.

Determination of dilution factors for discharge of aluminum-containing wastes by public water-supply treatment facilities into lakes and reservoirs in Massachusetts

USGS Publications Warehouse

Colman, John A.; Massey, Andrew J.; Brandt, Sara L.

2011-09-16

Dilution of aluminum discharged to reservoirs in filter-backwash effluents at water-treatment facilities in Massachusetts was investigated by a field study and computer simulation. Determination of dilution is needed so that permits for discharge ensure compliance with water-quality standards for aquatic life. The U.S. Environmental Protection Agency chronic standard for aluminum, 87 micrograms per liter (μg/L), rather than the acute standard, 750 μg/L, was used in this investigation because the time scales of chronic exposure (days) more nearly match rates of change in reservoir concentrations than do the time scales of acute exposure (hours).Whereas dilution factors are routinely computed for effluents discharged to streams solely on the basis of flow of the effluent and flow of the receiving stream, dilution determination for effluents discharged to reservoirs is more complex because (1), compared to streams, additional water is available for dilution in reservoirs during low flows as a result of reservoir flushing and storage during higher flows, and (2) aluminum removal in reservoirs occurs by aluminum sedimentation during the residence time of water in the reservoir. Possible resuspension of settled aluminum was not considered in this investigation. An additional concern for setting discharge standards is the substantial concentration of aluminum that can be naturally present in ambient surface waters, usually in association with dissolved organic carbon (DOC), which can bind aluminum and keep it in solution.A method for dilution determination was developed using a mass-balance equation for aluminum and considering sources of aluminum from groundwater, surface water, and filter-backwash effluents and losses caused by sedimentation, water withdrawal, and spill discharge from the reservoir. The method was applied to 13 reservoirs. Data on aluminum and DOC concentrations in reservoirs and influent water were collected during the fall of 2009. Complete reservoir volume was determined to be available for mixing on the basis of vertical and horizontal aluminum-concentration profiling. Losses caused by settling of aluminum were assumed to be proportional to aluminum concentration and reservoir area. The constant of proportionality, as a function of DOC concentration, was established by simulations in each of five reservoirs that differed in DOC concentration.In addition to computing dilution factors, the project determined dilution factors that would be protective with the same statistical basis (frequency of exceedance of the chronic standard) as dilutions computed for streams at the 7-day-average 10-year-recurrence annual low flow (the 7Q10). Low-flow dilutions are used for permitting so that receiving waters are protected even at the worst-case flow levels. The low-flow dilution factors that give the same statistical protection are the lowest annual 7-day-average dilution factors with a recurrence of 10 years, termed 7DF10s. Determination of 7DF10 values for reservoirs required that long periods of record be simulated so that dilution statistics could be determined. Dilution statistics were simulated for 13 reservoirs from 1960 to 2004 using U.S. Geological Survey Firm-Yield Estimator software to model reservoir inputs and outputs and present-day values of filter-effluent discharge and aluminum concentration.Computed settling velocities ranged from 0 centimeters per day (cm/d) at DOC concentrations of 15.5 milligrams per liter (mg/L) to 21.5 cm/d at DOC concentrations of 2.7 mg/L. The 7DF10 values were a function of aluminum effluent discharged. At current (2009) effluent discharge rates, the 7DF10 values varied from 1.8 to 115 among the 13 reservoirs. In most cases, the present-day (2009) discharge resulted in receiving water concentrations that did not exceed the standard at the 7DF10. Exceptions were one reservoir with a very small area and three reservoirs with high concentrations of DOC. Maximum permissible discharges were determined for water-treatment plants by adjusting discharges upward in simulations until the 7DF10 resulted in reservoir concentrations that just met the standard. In terms of aluminum flux, these discharges ranged from 0 to 28 kilograms of aluminum per day.

Effect of dilution temperature on boar semen quality.

PubMed

López Rodríguez, A; Rijsselaere, T; Vyt, P; Van Soom, A; Maes, D

2012-10-01

As boar semen is very sensitive to cold shock and changes in temperature during semen processing can have a profound impact on semen quality, the effect of the extender temperature at the time of dilution was investigated in a two-step dilution protocol for boar semen being processed for liquid storage. Fifteen boars of different breeds and ages from a commercial artificial insemination centre were included. One ejaculate per boar was collected and processed with Beltsville Thawing Solution semen extender. Each ejaculate was diluted (1 : 1) at 30 °C, and subsequently, the samples were diluted (30 × 10(6) sperm/ml) with either preheated extender [29.3 °C ± 0.2 °C, group A (GA)] or extender at room temperature [22.7 °C ± 0.6 °C, group B (GB)]. Samples were transported to the Faculty of Veterinary Medicine (University of Ghent, Belgium) in two isotherm boxes (one per group), stored at 17 °C and investigated for three consecutive days (D0 to D2). At D0, D1 and D2, motility parameters [computer-assisted semen analysis (CASA)] and the per cent of sperm with intact membrane (% IM) by eosin nigrosin staining were evaluated. At D0 and D2, the % of sperm with intact acrosome (% IA) was studied by Pisum sativum agglutinin staining. The average temperature of the 1 : 1 dilution was 29.4 °C ± 1.1 °C immediately after extender addition. No significant differences were found between groups for per cent motility [79.3 ± 9.0 for GA and 81.1 ± 9.2 for GB (p = 0.372)], % progressive motility [56.5 ± 13.3 for GA and 58.4 ± 13.8 for GB (p = 0.737)] or any CASA parameter. No differences were found for % IM [85.1 ± 10.7 and 84.5 ± 3.8 for GA and GB, respectively (p = 0.761)] and % IA [72.2 ± 9.4 for GA and 68.3 ± 16.6 for GB (p = 0.792)]. In conclusion, when a two-step dilution is performed, preheating the extender for the second dilution to match the semen temperature did not result in better semen quality compared to a dilution at a moderate room temperature. © 2011 Blackwell Verlag GmbH.

Use of ATP to characterize biomass viability in freely suspended and immobilized cell bioreactors

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

Gikas, P.; Livingston, A.G.

1993-12-01

This work describes investigations into the viability of cells growing on 3,4-dichloroaniline (34DCA). Two bio-reactors are employed for microbial growth, a continuous stirred tank (CST) bioreactor with a 2-L working volume, and a three-phase air lift (TPAL) bioreactor with a 3-L working volume. Experiments have been performed at several dilution rates between 0.027 and 0.115 h[sup [minus]1] in the CST bioreactor and between 0.111 and 0.500h[sup [minus]1] in the TPAL bioreactor. The specific ATP concentration was calculated at each dilution rate in the suspended biomass in both bioreactors as well as in the immobilized biomass in the TPAL bioreactor. Themore » cultures were inspected under an electron microscope to monitor compositional changes. Results from the CST bioreactor showed that the biomass-specific ATP concentration increases from 0.44 to 1.86 mg ATP g[sup [minus]1] dry weight (dw) as dilution rate increases from 0.027 to 0.115 h[sup [minus]1]. At this upper dilution rate the cells were washed out. The specific ATP concentration reached a limiting average value of 1.73 mg ATP g[sup [minus]1] dw, which is assumed to be the quantity of ATP in 100% viable biomass, In the TPAL bioreactor, the ATP level increased with dilution rat in both the immobilized and suspended biomass. The specific ATP concentration in the immobilized biomass increased from approximately 0.051 mg ATP g[sup [minus]1] dw at dilution rates between 0.111 and 0.200 h[sup [minus]1] to approximately 0.119 mg ATP g[sup [minus]1] dw at dilution rates between 0.300 and 0.500 h[sup [minus]1].« less

Predicting solubilisation features of ternary phase diagrams of fully dilutable lecithin linker microemulsions.

PubMed

Nouraei, Mehdi; Acosta, Edgar J

2017-06-01

Fully dilutable microemulsions (μEs), used to design self-microemulsifying delivery system (SMEDS), are formulated as concentrate solutions containing oil and surfactants, without water. As water is added to dilute these systems, various μEs are produced (water-swollen reverse micelles, bicontinuous systems, and oil-swollen micelles), without the onset of phase separation. Currently, the formulation dilutable μEs follows a trial and error approach that has had a limited success. The objective of this work is to introduce the use of the hydrophilic-lipophilic-difference (HLD) and net-average-curvature (NAC) frameworks to predict the solubilisation features of ternary phase diagrams of lecithin-linker μEs and the use of these predictions to guide the formulation of dilutable μEs. To this end, the characteristic curvatures (Cc) of soybean lecithin (surfactant), glycerol monooleate (lipophilic linker) and polyglycerol caprylate (hydrophilic linker) and the equivalent alkane carbon number (EACN) of ethyl caprate (oil) were obtained via phase scans with reference surfactant-oil systems. These parameters were then used to calculate the HLD of lecithin-linkers-ethyl caprate microemulsions. The calculated HLDs were able to predict the phase transitions observed in the phase scans. The NAC was then used to fit and predict phase volumes obtained from salinity phase scans, and to predict the solubilisation features of ternary phase diagrams of the lecithin-linker formulations. The HLD-NAC predictions were reasonably accurate, and indicated that the largest region for dilutable μEs was obtained with slightly negative HLD values. The NAC framework also predicted, and explained, the changes in microemulsion properties along dilution lines. Copyright © 2017 Elsevier Inc. All rights reserved.

Enrichment and detection of microorganisms involved in direct and indirect methanogenesis from methanol in an anaerobic thermophilic bioreactor.

PubMed

Roest, Kees; Altinbas, Mahmut; Paulo, Paula L; Heilig, H G H J; Akkermans, Antoon D L; Smidt, Hauke; de Vos, Willem M; Stams, Alfons J M

2005-10-01

To gain insight into the microorganisms involved in direct and indirect methane formation from methanol in a laboratory-scale thermophilic (55 degrees C) methanogenic bioreactor, reactor sludge was disrupted and serial dilutions were incubated in specific growth media containing methanol and possible intermediates of methanol degradation as substrates. With methanol, growth was observed up to a dilution of 10(8). However, when Methanothermobacter thermoautotrophicus strain Z245 was added for H2 removal, growth was observed up to a 10(10)-fold dilution. With H2/CO2 and acetate, growth was observed up to dilutions of 10(9) and 10(4), respectively. Dominant microorganisms in the different dilutions were identified by 16S rRNA-gene diversity and sequence analysis. Furthermore, dilution polymerase chain reaction (PCR) revealed a similar relative abundance of Archaea and Bacteria in all investigated samples, except in enrichment with acetate, which contained 100 times less archaeal DNA than bacterial DNA. The most abundant bacteria in the culture with methanol and strain Z245 were most closely related to Moorella glycerini. Thermodesulfovibrio relatives were found with high sequence similarity in the H2/CO2 enrichment, but also in the original laboratory-scale bioreactor sludge. Methanothermobacter thermoautotrophicus strains were the most abundant hydrogenotrophic archaea in the H2/CO2 enrichment. The dominant methanol-utilizing methanogen, which was present in the 10(8)-dilution, was most closely related to Methanomethylovorans hollandica. Compared to direct methanogenesis, results of this study indicate that syntrophic, interspecies hydrogen transfer-dependent methanol conversion is equally important in the thermophilic bioreactor, confirming previous findings with labeled substrates and specific inhibitors.

[Effect of self-microemulsifying system on cell tight junctions].

PubMed

Sha, Xian-Yi; Fang, Xiao-Ling

2006-01-01

To study the effect of negatively charged and positively charged self-microemulsifying systems (SMES) on the cellular tight junction complex was to be investigated at molecular cell level. Human intestinal epithelial Caco-2 cell model was established. Effect of formulations on the transepithelial electrical resistance (TEER) and permeability of the paracellular transport marker mannitol were measured to evaluate the cell integrity. Changes in subcellular localization of the tight junction protein zona occludens 1 (ZO-1) and cytoskeleton protein actin by immunofluorescence were also assessed after treatment of two SMESs in different dilutions. The TEER of cell monolayers was not markedly affected by negatively charged SMES in different dilutions. The positively charged SMES could significantly decrease the TEER (P < 0.05) in three dilutions. The full recovery of TEER was found after the treatment of lower dilution for 2 h, then cultured for 48 h, while the recovery of TEER was 81.3% of control in 1 : 50 dilution. Two SMESs could enhance the apparent permeability coefficient of mannitol (2.9 - 64.6 folds), which depended on the dilution times. The immunofluorescent results indicated that the distribution of ZO-1 and actin were discrete in cell membrane after the treatment of formulation. Since the positively charged microemulsion could bind to the epithelial cell membrane by electrostatic interaction, the actin of the cells undergone some kind of stress stimulated by the higher concentration of microemulsion was more markedly affected than the negatively charged SMES. Effect of formulations on ZO-1 and actin relied on the dilution. SMES is able to enhance the paracellular transport marker mannitol. The mechanism of opening of tight junctions by SMES might be the change of distribution of ZO-1 and actin.

Colloid osmotic pressure and extravasation of plasma proteins following infusion of Ringer's acetate and hydroxyethyl starch 130/0.4.

PubMed

Zdolsek, J H; Bergek, C; Lindahl, T L; Hahn, R G

2015-11-01

During fluid infusion therapy, plasma proteins are diluted and leak from the intravascular space, which alters the colloid osmotic pressure (COP) and potentially affects coagulation. We hypothesised that acetated Ringer's and starch solution, alone or in combination, influence these mechanisms differently. On different occasions, 10 male volunteers were infused with 20 ml/kg acetated Ringer's and 10 ml/kg 6% hyroxyethyl starch 130/0.4 (Voluven(®) ) alone or in combination (first with starch solution followed by Ringer's solution). Blood samples were collected every 30-min for measurements of COP, blood haemoglobin, platelets, and plasma concentrations of albumin, immunoglobulins (IgG and IgM), coagulation factor VII (FVII), fibrinogen, cystatin C, activated partial thromboplastin time (APTT) and prothrombin international normalised ratio (PT-INR). Changes were compared with the haemoglobin-derived plasma dilution. The COP increased by 8.4% (SD 3) with starch and decreased by 26.2% (7.9) with Ringer's. These infusions diluted the plasma by 23.4% (5.3) and 18.7% (4.9) respectively. The COP changes in the combined experiment followed the same pattern as the individual infusions. Albumin and IgG changes in excess of the plasma dilution were very subtle. The intravascular contents of the IgM and platelets decreased, whereas FVII, fibrinogen and cystatin C increased. PT-INR increased by 1/3 of the plasma dilution, whereas changes in APTT did not correlate with the plasma dilution. The starch increased COP and only minor capillary leak occurred in healthy volunteers. The fluid-induced plasma dilution correlated with mild impairment of the extrinsic coagulation pathway but not of the intrinsic pathway. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Estimation of the volatility distribution of organic aerosol combining thermodenuder and isothermal dilution measurements

NASA Astrophysics Data System (ADS)

Louvaris, Evangelos E.; Karnezi, Eleni; Kostenidou, Evangelia; Kaltsonoudis, Christos; Pandis, Spyros N.

2017-10-01

A method is developed following the work of Grieshop et al. (2009) for the determination of the organic aerosol (OA) volatility distribution combining thermodenuder (TD) and isothermal dilution measurements. The approach was tested in experiments that were conducted in a smog chamber using organic aerosol (OA) produced during meat charbroiling. A TD was operated at temperatures ranging from 25 to 250 °C with a 14 s centerline residence time coupled to a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a scanning mobility particle sizer (SMPS). In parallel, a dilution chamber filled with clean air was used to dilute isothermally the aerosol of the larger chamber by approximately a factor of 10. The OA mass fraction remaining was measured as a function of temperature in the TD and as a function of time in the isothermal dilution chamber. These two sets of measurements were used together to estimate the volatility distribution of the OA and its effective vaporization enthalpy and accommodation coefficient. In the isothermal dilution experiments approximately 20 % of the OA evaporated within 15 min. Almost all the OA evaporated in the TD at approximately 200 °C. The resulting volatility distributions suggested that around 60-75 % of the cooking OA (COA) at concentrations around 500 µg m-3 consisted of low-volatility organic compounds (LVOCs), 20-30 % of semivolatile organic compounds (SVOCs), and around 10 % of intermediate-volatility organic compounds (IVOCs). The estimated effective vaporization enthalpy of COA was 100 ± 20 kJ mol-1 and the effective accommodation coefficient was 0.06-0.07. Addition of the dilution measurements to the TD data results in a lower uncertainty of the estimated vaporization enthalpy as well as the SVOC content of the OA.

Permanent physico-chemical properties of extremely diluted aqueous solutions of homeopathic medicines.

PubMed

Elia, V; Baiano, S; Duro, I; Napoli, E; Niccoli, M; Nonatelli, L

2004-07-01

The purpose of this study was to obtain information about the influence of successive dilutions and succussions on the water structure. 'Extremely diluted solutions' (EDS) are solutions obtained through the iteration of two processes: dilution in stages of 1:100 and succussion, typically used in homeopathic medicine. The iteration is repeated until extreme dilutions are reached, so that the chemical composition of the solution is identical to that of the solvent. Nine different preparations, were studied from the 3cH to 30cH (Hahnemannian Centesimal Dilution). Four of those were without the active principle (potentized water). Two different active principles were used: Arsenicum sulphuratum rubrum (ASR), As4S4, 2,4-dichlorophenoxyacetic acid (2,4D). The solvents were: a solution of sodium bicarbonate and of silicic acid at 5 x 10(-5) M (mol/l) each, and solutions of sodium bicarbonate 5 x 10(-5), 7.5 x 10(-5) and 10 x 10(-5) M (mol/l) in double-distilled water. The containers were Pyrex glass to avoid the release of alkaline oxide and silica from the walls. Conductivity measurements of the solutions were carried out as a function of the age of the potencies. We found increases of electrical conductivity compared to untreated solvent. Successive dilution and succussion can permanently alter the physico-chemical properties of the aqueous solvent. But we also detected changes in physio-chemical parameters with time. This has not previously been reported. The modification of the solvent could provide an important support to the validity of homeopathic medicine, that employs 'medicines without molecules'. The nature of the phenomena here described remains still unexplained, nevertheless some significant experimental results were obtained.

Evaluation of in vitro properties of di-tri-octahedral smectite on clostridial toxins and growth.

PubMed

Weese, J S; Cote, N M; deGannes, R V G

2003-11-01

Clostridial colitis and endotoxaemia of intestinal origin are significant causes of morbidity and mortality in horses. Intestinal adsorbents are available for treatment of these conditions; however, little information exists supporting their use. To evaluate the ability of di-tri-octahedral smectite to bind to Clostridium difficile toxins A and B, C. perfringens enterotoxin and endotoxin, inhibit clostridial growth and the actions of metronidazole in vitro. Clostridium difficile toxins, C. perfringens enterotoxin and endotoxin were mixed with serial dilutions of di-tri-octahedral smectite, then tested for the presence of clostridial toxins or endotoxin using commercial tests. Serial dilutions of smectite were tested for the ability to inhibit growth of C. perfringens in culture broth, and to interfere with the effect of metronidazole on growth of C. perfringens in culture broth. Clostridium difficile toxins A and B, and C. perfringens enterotoxin were completely bound at dilutions of 1:2 to 1:16. Partial binding of C. difficile toxins occurred at dilutions up to 1:256 while partial binding of C. perfringens enterotoxin occurred up to a dilution of 1:128. Greater than 99% binding of endotoxin occurred with dilutions 1:2 to 1:32. No inhibition of growth of C. difficile or C. perfringens was present at any dilution, and there was no effect on the action of metronidazole. Di-tri-octahedral smectite possesses the ability to bind C. difficile toxins A and B, C. perfringens enterotoxin and endotoxin in vivo while having no effect on bacterial growth or the action of metronidazole. In vivo studies are required to determine whether di-tri-octahedral smectite might be a useful adjunctive treatment of clostridial colitis and endotoxaemia in horses.

Honey dilution impact on in vitro wound healing: Normoxic and hypoxic condition.

PubMed

Chaudhary, Amrita; Bag, Swarnendu; Barui, Ananya; Banerjee, Provas; Chatterjee, Jyotirmoy

2015-01-01

Honey is known as a popular healing agent against tropical infections and wounds. However, the effects of honey dilutions on keratinocyte (HaCaT) wound healing under hypoxic condition is still not explored. In this study, we examined whether honey dilution have wound healing potential under hypoxic stress. The antioxidant potential and healing efficacy of honey dilution on in vitro wound of human epidermal keratinocyte (HaCaT cells) under hypoxia (3% O2 ), and normoxia is explored by nitro blue tetrazolium assay. The cell survival % quantified by MTT assay to select four honey dilutions like 10, 1, 0.1, and 0.01 v/v% and the changes in cellular function was observed microscopically. Further, the cell proliferation, migration, cell-cell adhesion, and relevant gene expression were studied by flow cytometry, migration/scratch assay, immunocytochemistry, and reverse transcription-polymerase chain reaction, respectively. The expression pattern of cardinal molecular features viz. E-cadherin, cytoskeletal protein F-actin, p63, and hypoxia marker Hif 1α were examined. Honey dilution in 0.1% v/v combat wound healing limitations in vitro under normoxia and hypoxia (3%). Its wound healing potential was quantified by immunocytochemistry and real-time PCR for the associated molecular features that were responsible for cell proliferation and migration. Our data showed that honey dilution can be effective in hypoxic wound healing. Additionally, it reduced superoxide generation and supplied favorable bioambience for cell proliferation, migration, and differentiation during hypoxic wound healing. These findings may reveal the importance of honey as an alternative and cost effective therapeutic natural product for wound healing in hypoxic condition. © 2015 by the Wound Healing Society.

Isotope dilution ICP-MS with laser-assisted sample introduction for direct determination of sulfur in petroleum products.

PubMed

Boulyga, Sergei F; Heilmann, Jens; Heumann, Klaus G

2005-08-01

Inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with direct laser-assisted introduction of isotope-diluted samples into the plasma, using a laser ablation system with high ablation rates, was developed for accurate sulfur determinations in different petroleum products such as 'sulfur-free' premium gasoline, diesel fuel, and heating oil. Two certified gas oil reference materials were analyzed for method validation. Two different 34S-enriched spike compounds, namely, elementary sulfur dissolved in xylene and dibenzothiophene in hexane, were synthesized and tested for their usefulness in this isotope dilution technique. The isotope-diluted sample was adsorbed on a filter-paper-like material, which was fixed in a special holder for irradiation by the laser beam. Under these conditions no time-dependent spike/analyte fractionation was only observed for the dibenzothiophene spike during the laser ablation process, which means that the measured 34S/32S isotope ratio of the isotope-diluted sample remained constant-a necessary precondition for accurate results with the isotope dilution technique. A comparison of LA-ICP-IDMS results with the certified values of the gas oil reference materials and with results obtained from ICP-IDMS analyses with wet sample digestion demonstrated the accuracy of the new LA-ICP-IDMS method in the concentration range of 9.2 microg g(-1) ('sulfur-free' premium gasoline) to 10.4 mg g(-1) (gas oil reference material BCR 107). The detection limit for sulfur by LA-ICP-IDMS is 0.04 microg g(-1) and the analysis time is only about 10 min, which therefore also qualifies this method for accurate determinations of low sulfur contents in petroleum products on a routine level.

Correlation Between Iron and alpha and pi Glutathione-S-Transferase Levels in Humans

DTIC Science & Technology

2012-09-01

assays were performed as described in the Biotrin High Sensitivity Alpha GST EIA kit protocol. First, serum samples were diluted 1:10 with wash solution...immunosorbent assays were performed as described in the Biotrin Pi GST EIA kit protocol. First, plasma samples were diluted 1:5 with sample diluent...immunosorbent assays were performed as described in the AssayMax Human Transferrin ELISA kit protocol. First, serum samples were diluted 1:2000 with MIX

Creatine Supplementation Increases Total Body Water in Soccer Players: a Deuterium Oxide Dilution Study.

PubMed

Deminice, R; Rosa, F T; Pfrimer, K; Ferrioli, E; Jordao, A A; Freitas, E

2016-02-01

This study aimed to evaluate changes in total body water (TBW) in soccer athletes using a deuterium oxide dilution method and bioelectrical impedance (BIA) formulas after 7 days of creatine supplementation. In a double-blind controlled manner, 13 healthy (under-20) soccer players were divided randomly in 2 supplementation groups: Placebo (Pla, n=6) and creatine supplementation (CR, n=7). Before and after the supplementation period (0.3 g/kg/d during 7 days), TBW was determined by deuterium oxide dilution and BIA methods. 7 days of creatine supplementation lead to a large increase in TBW (2.3±1.0 L) determined by deuterium oxide dilution, and a small but significant increase in total body weight (1.0±0.4 kg) in Cr group compared to Pla. The Pla group did not experience any significant changes in TBW or body weight. Although 5 of 6 BIA equations were sensitive to determine TBW changes induced by creatine supplementation, the Kushner et al. 16 method presented the best concordance levels when compared to deuterium dilution method. In conclusion, 7-days of creatine supplementation increased TBW determined by deuterium oxide dilution or BIA formulas. BIA can be useful to determine TBW changes promoted by creatine supplementation in soccer athletes, with special concern for formula choice. © Georg Thieme Verlag KG Stuttgart · New York.

The development of a practicable method for deepfreezing of boar spermatozoa.

PubMed

Larsson, K; Einarsson, S; Swensson, T

1977-03-01

The present study was made in order to develop the freezing method of Crabo & Einarsson (1971) into a practicable deep-freezing method for boar spermatozoa. Semen was concentrated before dilution and a dosewise thawing procedure for the pellet-frozen semen was utilized. Two fertility tests on altogther 68 gilts were performed. In the first trial the insemination doses contained 6x10(9) spermatozoa and the dilution rate before cooling was 3:2 with a total dilution before freezing of 3:7. In the second trial the insemination doses contained 4.5x10(9) spermatozoa, primary dilution was 3:3 and final dilution 3:7. The pregnancy rate in trial 1 was 53% and in trial 2 72%. Mean litter size in pregnant gilts was 6.5 in trial 1 and 9.7 in trial 2. The difference in ratio of foetuses to c.l. in pregnant gilts between the trials was highly significant. The different dilution procedures are discussed and the lower fertility of semen frozen in trial 1 is suggested to be due to a shortened fertile life of spermatozoa so treated. The freezing method utilized in trial 2 is considered to be practically acceptable and the results are concluded to be satisfactory. A detailed description of the method and the equipment utilized can be requested from the authors.

Motor-mediated microtubule self-organization in dilute and semi-dilute filament solutions.

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

Swaminathan, S.; Ziebert, F.; Aranson, I. S.

We study molecular motor-induced microtubule self-organization in dilute and semi-dilute filament solutions. In the dilute case, we use a probabilistic model of microtubule interaction via molecular motors to investigate microtubule bundle dynamics. Microtubules are modeled as polar rods interacting through fully inelastic, binary collisions. Our model indicates that initially disordered systems of interacting rods exhibit an orientational instability resulting in spontaneous ordering. We study the existence and dynamic interaction of microtubule bundles analytically and numerically. Our results reveal a long term attraction and coalescing of bundles indicating a clear coarsening in the system; microtubule bundles concentrate into fewer orientations onmore » a slow logarithmic time scale. In semi-dilute filament solutions, multiple motors can bind a filament to several others and, for a critical motor density, induce a transition to an ordered phase with a nonzero mean orientation. Motors attach to a pair of filaments and walk along the pair bringing them into closer alignment. We develop a spatially homogenous, mean-field theory that explicitly accounts for a force-dependent detachment rate of motors, which in turn affects the mean and the fluctuations of the net force acting on a filament. We show that the transition to the oriented state can be both continuous and discontinuous when the force-dependent detachment of motors is important.« less

Effect of Water Surface Salinity on Evaporation: The Case of a Diluted Buoyant Plume Over the Dead Sea

NASA Astrophysics Data System (ADS)

Mor, Z.; Assouline, S.; Tanny, J.; Lensky, I. M.; Lensky, N. G.

2018-03-01

Evaporation from water bodies strongly depends on surface water salinity. Spatial variation of surface salinity of saline water bodies commonly occurs across diluted buoyant plumes fed by freshwater inflows. Although mainly studied at the pan evaporation scale, the effect of surface water salinity on evaporation has not yet been investigated by means of direct measurement at the scale of natural water bodies. The Dead Sea, a large hypersaline lake, is fed by onshore freshwater springs that form local diluted buoyant plumes, offering a unique opportunity to explore this effect. Surface heat fluxes, micrometeorological variables, and water temperature and salinity profiles were measured simultaneously and directly over the salty lake and over a region of diluted buoyant plume. Relatively close meteorological conditions prevailed in the two regions; however, surface water salinity was significantly different. Evaporation rate from the diluted plume was occasionally 3 times larger than that of the main salty lake. In the open lake, where salinity was uniform with depth, increased wind speed resulted in increased evaporation rate, as expected. However, in the buoyant plume where diluted brine floats over the hypersaline brine, wind speed above a threshold value (˜4 m s-1) caused a sharp decrease in evaporation probably due to mixing of the stratified plume and a consequent increase in the surface water salinity.

[Formation of oxalate in oxaliplatin injection diluted with infusion solutions].

PubMed

Eto, Seiji; Yamamoto, Kie; Shimazu, Kounosuke; Sugiura, Toshimune; Baba, Kaori; Sato, Ayaka; Goromaru, Takeshi; Hagiwara, Yoshiaki; Hara, Keiko; Shinohara, Yoshitake; Takahashi, Kojiro

2014-01-01

Oxaliplatin use can cause acute peripheral neuropathy characterized by sensory paresthesias, which are markedly exacerbated by exposure to cold temperatures, and is a dose-limiting factor in the treatment of colorectal cancer.Oxalate is eliminated in a series of nonenzymatic conversions of oxaliplatin in infusion solutions or biological fluids.Elimination of oxalate from oxaliplatin has been suggested as one of the reasons for the development of acute neuropathy.In this study, we developed a high-performance liquid chromatography(HPLC)-based method to detect oxalate formation, and investigated the time dependent formation of oxalate in oxaliplatin diluted with infusion solutions.The results obtained showed that the amount of oxalate in the solution corresponded to 1.6% of oxaliplatin 8 h after oxaliplatin dilution with a 5% glucose solution. On the other hand, oxalate formation from oxaliplatin diluted with a saline solution was ten-fold higher than that from oxaliplatin diluted with the 5% glucose solution.Most patients who were intravenously injected with oxaliplatin experienced venous pain.As a preventive measure against venous pain, dexamethasone was added to the oxaliplatin injection.We measured the amount of oxalate formed in the dexamethasone-containing oxaliplatin injection diluted with a 5% glucose solution.The amount of oxalate formed when dexamethasone was added did not differ significantly from that formed when dexamethasone was not added.Thus, there are no clinical problems associated with the stability of oxaliplatin solutions.

Investigation of Possible Maillard Reaction Between Acyclovir and Dextrose upon Dilution Prior to Parenteral Administration.

PubMed

Siahi Shadbad, Mohammad Reza; Ghaderi, Faranak; Hatami, Leila; Monajjemzadeh, Farnaz

2016-12-01

In this study the stability of parenteral acyclovir (ACV) when diluted in dextrose (DEX) as large volume intravenous fluid preparation (LVIF) was evaluated and the possible Maillard reaction adducts were monitored in the recommended infusion time. Different physicochemical methods were used to evaluate the Maillard reaction of dextrose with ACV to track the reaction in real infusion condition. Other large volume intravenous fluids were checked regarding the diluted drug stability profile. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and mass data proved the reaction of glucose with dextrose. A Maillard-specific high performance liquid chromatography (HPLC) method was used to track the reaction in real infusion condition in vitro. The nucleophilic reaction occurred in diluted parenteral preparations of acyclovir in 5% dextrose solutions. The best diluent solution was also selected as sodium chloride and introduced based on drug stability and also its adsorption onto different infusion sets (PVC or non PVC) to provide an acceptable administration protocol in clinical practices. Although, the Maillard reaction was proved and successfully tracked in diluted solutions, and the level of drug loss when diluted in dextrose was reported to be between 0.27 up to 1.03% of the initial content. There was no drug adsorption to common infusion sets. The best diluent for parenteral acyclovir is sodium chloride large volume intravenous fluid.

The diversity-disease relationship: evidence for and criticisms of the dilution effect.

PubMed

Huang, Z Y X; VAN Langevelde, F; Estrada-Peña, A; Suzán, G; DE Boer, W F

2016-08-01

The dilution effect, that high host species diversity can reduce disease risk, has attracted much attention in the context of global biodiversity decline and increasing disease emergence. Recent studies have criticized the generality of the dilution effect and argued that it only occurs under certain circumstances. Nevertheless, evidence for the existence of a dilution effect was reported in about 80% of the studies that addressed the diversity-disease relationship, and a recent meta-analysis found that the dilution effect is widespread. We here review supporting and critical studies, point out the causes underlying the current disputes. The dilution is expected to be strong when the competent host species tend to remain when species diversity declines, characterized as a negative relationship between species' reservoir competence and local extinction risk. We here conclude that most studies support a negative competence-extinction relationship. We then synthesize the current knowledge on how the diversity-disease relationship can be modified by particular species in community, by the scales of analyses, and by the disease risk measures. We also highlight the complex role of habitat fragmentation in the diversity-disease relationship from epidemiological, evolutionary and ecological perspectives, and construct a synthetic framework integrating these three perspectives. We suggest that future studies should test the diversity-disease relationship across different scales and consider the multiple effects of landscape fragmentation.

Investigations on Mg-borate kinetics and mechanisms during evaporation, dilution and crystallization by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Peng, Jiaoyu; Chen, Jing; Dong, Yaping; Li, Wu

2018-06-01

Raman spectra of boron-concentrated, diluted, and corresponding mother solutions of brine were recorded at 298.15 K. The main polyborate anions present and their interactions in brine during evaporation and dilution were proposed according to the Raman spectra. The polyborate anions B(OH)3, B3O3(OH)4-, B5O6(OH)4-, and B6O7(OH)62- were found to be the main forms in boron-concentrated brine with B3O3(OH)4- ion being the principal form. Diluting brines with water accelerated depolymerization of B5O6(OH)4- and B6O7(OH)62- anions into B(OH)3 and B3O3(OH)4- ions and generated OH- ions, causing the pH of the solutions to increase from 4.2 to almost 8.0. Mg-borates precipitated from all diluted solutions could be classified as either hexaborates or triborates. A mechanism of solid phase transformation was also proposed and discussed based on Raman spectra analysis and solid species and solution pH data.

Ab-initio study of dilute nitride substitutional and split-interstitial impurities in gallium antimonide (N-GaSb)

NASA Astrophysics Data System (ADS)

Jadaun, Priyamvada; Nair, Hari P.; Bank, Seth R.; Banerjee, Sanjay K.

2012-02-01

We present an ab-initio density functinal theory study of dilute-nitride GaSb. Adding dilute quantities of nitrogen causes rapid reduction in bandgap of GaSb (˜300 meV for 2% N). Due to this rapid reduction in bandgap, dilute-nitrides provide a pathway for extending the emission of GaSb based type-I diode lasers into the mid-infrared wavelength region (3-5 micron). In this study we look at the effect of substitutional N impurity on the electronic properties of our system and compare it with the band-anticrossing model, a phenomenological model, which has been used to explain giant band bowing observed in dilute-nitride alloys. We also study the effect of Sb-N split interstitials which are known to be non-radiative recombination centers. Furthermore we also discuss the stability of the Sb-N split interstitial relative to substitutional nitrogen to determine if the split interstitials can be annihilated using post-growth annealing to improve the radiative lifetime of the material which essential for laser operation.

Evolution of magnetic and orbital properties in the magnetically diluted A -site spinel Cu1 -xZnxRh2O4

NASA Astrophysics Data System (ADS)

Zakrzewski, A. V.; Gangopadhyay, S.; MacDougall, G. J.; Aczel, A. A.; Calder, S.; Williams, T. J.

2018-06-01

In frustrated spinel antiferromagnets, dilution with nonmagnetic ions can be a powerful strategy for probing unconventional spin states or uncovering interesting phenomena. Here, we present x-ray, neutron scattering, and thermodynamic studies of the effects of magnetic dilution of the tetragonally distorted A -site spinel antiferromagnet, CuRh2O4 , with nonmagnetic Zn2 + ions. Our data confirm the helical spin order recently identified at low temperatures in this material, and further demonstrate a systematic suppression of the associated Néel temperature with increasing site dilution towards a continuous transition with critical doping of xspin˜0.44 . Interestingly, this critical doping is demonstrably distinct from a second structural critical point at xJ T˜0.6 , which is consistent with the suppression of orbital order on the A site through a classical percolative mechanism. This anomalously low value for xspin is confirmed via multiple measurements, and is inconsistent with predictions of classical percolation theory, suggesting that the spin transition in this material is driven by an enhancement of preexisting spin fluctuations with weak dilution.

Effect of feeding mode and dilution on the performance and microbial community population in anaerobic digestion of food waste.

PubMed

Park, Jong-Hun; Kumar, Gopalakrishnan; Yun, Yeo-Myeong; Kwon, Joong-Chun; Kim, Sang-Hyoun

2018-01-01

The effect of feeding mode and dilution was studied in anaerobic digestion of food waste. An upflow anaerobic digester with a settler was fed at six different organic loading rates (OLRs) from 4.6 to 8.6kgCOD/m 3 /d for 200days. The highest methane productivity of 2.78LCH 4 /L/d was achieved at 8.6kgCOD/m 3 /d during continuous feeding of diluted FW. Continuous feeding of diluted food waste showed more stable and efficient performance than stepwise feeding of undiluted food waste. Sharp increase in propionate concentration attributed towards deterioration of the digester performances in stepwise feeding of undiluted food waste. Microbial communities at various OLRs divulged that the microbial distribution in the continuous feeding of diluted food waste was not significantly perturbed despite the increase of OLR up to 8.6kgCOD/m 3 /d, which was contrast to the unstable distribution in stepwise feeding of undiluted food waste at 6.1kgCOD/m 3 /d. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel method for on-road emission factor measurements using a plume capture trailer.

PubMed

Morawska, L; Ristovski, Z D; Johnson, G R; Jayaratne, E R; Mengersen, K

2007-01-15

The method outlined provides for emission factor measurements to be made for unmodified vehicles driving under real world conditions at minimal cost. The method consists of a plume capture trailer towed behind a test vehicle. The trailer collects a sample of the naturally diluted plume in a 200 L conductive bag and this is delivered immediately to a mobile laboratory for subsequent analysis of particulate and gaseous emissions. The method offers low test turnaround times with the potential to complete much larger numbers of emission factor measurements than have been possible using dynamometer testing. Samples can be collected at distances up to 3 m from the exhaust pipe allowing investigation of early dilution processes. Particle size distribution measurements, as well as particle number and mass emission factor measurements, based on naturally diluted plumes are presented. A dilution profile relating the plume dilution ratio to distance from the vehicle tail pipe for a diesel passenger vehicle is also presented. Such profiles are an essential input for new mechanistic roadway air quality models.

Helium dilution refrigeration system

DOEpatents

Roach, Patrick R.; Gray, Kenneth E.

1988-01-01

A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains .sup.3 He and .sup.4 He liquids which are precooled by a coupled container containing .sup.3 He liquid, enabling the phase separation of a .sup.3 He rich liquid phase from a dilute .sup.3 He-.sup.4 He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the .sup.3 He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute .sup.3 He-.sup.4 He liquid phase.

Helium dilution refrigeration system

DOEpatents

Roach, P.R.; Gray, K.E.

1988-09-13

A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation is disclosed. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains [sup 3]He and [sup 4]He liquids which are precooled by a coupled container containing [sup 3]He liquid, enabling the phase separation of a [sup 3]He rich liquid phase from a dilute [sup 3]He-[sup 4]He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the [sup 3]He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute [sup 3]He-[sup 4]He liquid phase. 2 figs.

Analysis of boron dilution in a four-loop PWR

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

Sun, J.G.; Sha, W.T.

1995-12-31

Thermal mixing and boron dilution in a pressurized water reactor were analyzed with COMMIX codes. The reactor system was the four loop Zion reactor. Two boron dilution scenarios were analyzed. In the first scenario, the plant is in cold shutdown and the reactor coolant system has just been filled after maintenance on the steam generators. To flush the air out of the steam generator tubes, a reactor coolant pump (RCP) is started, with the water in the pump suction line devoid of boron and at the same temperature as the coolant in the system. In the second scenario, the plantmore » is at hot standby and the reactor coolant system has been heated up to operating temperature after a long outage. It is assumed that an RCP is started, with the pump suction line filled with cold unborated water, forcing a slug of diluted coolant down the downcomer and subsequently through the reactor core. The subsequent transient thermal mixing and boron dilution that would occur in the reactor system is simulated for these two scenarios. The reactivity insertion rate and the total reactivity are evaluated.« less

Solubilization of Tea Seed Oil in a Food-Grade Water-Dilutable Microemulsion

PubMed Central

Deng, Lingli; Que, Fei; Wei, Hewen; Xu, Guangwei; Dong, Xiaowei; Zhang, Hui

2015-01-01

Food-grade microemulsions containing oleic acid, ethanol, Tween 20, and water were formulated as a carrier system for tea seed oil (Camellia oleifera Abel.). The effect of ethanol on the phase behavior of the microemulsion system was clearly reflected in pseudo-ternary diagrams. The solubilization capacity and solubilization efficiency of tea seed oil dispersions were measured along the dilution line at a 70/30 surfactant/oil mass ratio with Tween 20 as the surfactant and oleic acid and ethanol (1:3, w/w) as the oil phase. The dispersed phase of the microemulsion (1.5% weight ratio of tea seed oil to the total amount of oil, surfactant, and tea seed oil) could be fully diluted with water without phase separation. Differential scanning calorimetry and viscosity measurements indicated that both the carrier and solubilized systems underwent a similar microstructure transition upon dilution. The dispersion phases gradually inverted from the water-in-oil phase (< 35% water) to the bicontinuous phase (40–45% water) and finally to the oil-in-water phase (> 45% water) along the dilution line. PMID:25996147

Solubilization of tea seed oil in a food-grade water-dilutable microemulsion.

PubMed

Deng, Lingli; Que, Fei; Wei, Hewen; Xu, Guangwei; Dong, Xiaowei; Zhang, Hui

2015-01-01

Food-grade microemulsions containing oleic acid, ethanol, Tween 20, and water were formulated as a carrier system for tea seed oil (Camellia oleifera Abel.). The effect of ethanol on the phase behavior of the microemulsion system was clearly reflected in pseudo-ternary diagrams. The solubilization capacity and solubilization efficiency of tea seed oil dispersions were measured along the dilution line at a 70/30 surfactant/oil mass ratio with Tween 20 as the surfactant and oleic acid and ethanol (1:3, w/w) as the oil phase. The dispersed phase of the microemulsion (1.5% weight ratio of tea seed oil to the total amount of oil, surfactant, and tea seed oil) could be fully diluted with water without phase separation. Differential scanning calorimetry and viscosity measurements indicated that both the carrier and solubilized systems underwent a similar microstructure transition upon dilution. The dispersion phases gradually inverted from the water-in-oil phase (< 35% water) to the bicontinuous phase (40-45% water) and finally to the oil-in-water phase (> 45% water) along the dilution line.

Measurements of left-to-right intracardiac shunting in adults: oximetric versus indicator dilution techniques.

PubMed

Hillis, L D; Winniford, M D; Jackson, J A; Firth, B G

1985-01-01

Of the various techniques that are available to assess the presence and magnitude of intracardiac shunting, oximetry and indicator dilution are used most frequently. This study was performed to compare these methods in adult patients with pure left-to-right intracardiac shunting. In 27 patients [12 men, 15 women, aged 32 +/- 12 (mean +/- SD) years], shunt magnitude was assessed in close temporal proximity by both techniques. The oximetric percentage left-to-right shunt averaged 55 +/- 16%, whereas the indocyanine green dye percentage shunt was significantly less (36 +/- 14%, p less than 0.001). The oximetric percentage shunt exceeded the indocyanine green dye percentage shunt in 26 and did so by greater than 20% in 23 patients. Thus, there is a substantial difference in shunt magnitude between the oximetric and the indicator dilution techniques. In infants, indicator dilution yields results that are larger than those obtained with the oximetric method. Conversely, in adults, the indicator dilution technique gives results that are consistently smaller than those obtained with oximetry. As a result, the decision regarding therapy of an intracardiac shunt should be made with this in mind.

Stability of florfenicol in drinking water.

PubMed

Hayes, John M; Eichman, Jonathan; Katz, Terry; Gilewicz, Rosalia

2003-01-01

Florfenicol, a broad-spectrum antibiotic, is being developed for veterinary application as an oral concentrate intended for dilution with drinking water. When a drug product is dosed via drinking water in a farm setting, a number of variables, including pH, chlorine content, hardness of the water used for dilution, and container material, may affect its stability, leading to a decrease in drug potency. The stability of florfenicol after dilution of Florfenicol Drinking Water Concentrate Oral Solution, 23 mg/mL, with drinking water was studied. A stability-indicating, validated liquid chromatographic method was used to evaluate florfenicol stability at 25 degrees C at 5, 10, and 24 h after dilution. The results indicate that florfenicol is stable under a range of simulated field conditions, including various pipe materials and conditions of hard or soft and chlorinated or nonchlorinated water at low or high pH. Significant degradation (> 10%) was observed only for isolated combinations in galvanized pipes. Analysis indicated that the florfenicol concentration in 8 of the 12 water samples stored in galvanized pipes remained above 90% of the initial concentration (100 mg/L) for 24 h after dilution.

Mossbauer effect in dilute iron alloys

NASA Technical Reports Server (NTRS)

Singh, J. J.

1975-01-01

The effects of variable concentration, x, of Aluminum, Germanium, and Lanthanum atoms in Iron lattice on various Mossbauer parameters was studied. Dilute binary alloys of (Fe-Al), (Fe-Ge), (Fe-Al) containing up to x = 2 a/o of the dilute constituent were prepared in the form of ingots and rolled to a thickness of 0.001 in. Mossbauer spectra of these targets were then studied in transmission geometry to measure changes in the hyperfine field, peak widths isomer shifts as well as the ratio of the intensities of peaks (1,6) to the intensities of peaks (2,5). It was shown that the concept of effective hyperfine structure field in very dilute alloys provides a useful means of studying the effects of progressively increasing the solute concentration on host lattice properties.

Process of concentrating ethanol from dilute aqueous solutions thereof

DOEpatents

Oulman, C.S.; Chriswell, C.D.

1981-07-07

Relatively dilute aqueous solutions of ethanol are concentrated by passage through a bed of a crystalline silica polymorph, such as silicalite, to adsorb the ethanol with residual dilute feed in contact with the bed, which is displaced by passing concentrated aqueous ethanol through the bed without displacing the adsorbed ethanol. A product concentrate is then obtained by removing the adsorbed ethanol from the bed together with at least a portion of the concentrated aqueous ethanol used as the displacer liquid. This process permits ethanol to be concentrated from dilute fermentation beers, which may contain from 6 to 10% ethanol, to obtain a concentrate product at very low energy cost having an ethanol concentration in excess of 95%, such as a concentration of from 98 to 99.5%. 5 figs.

Process of concentrating ethanol from dilute aqueous solutions thereof

DOEpatents

Oulman, Charles S. [Ames, IA; Chriswell, Colin D. [Slater, IA

1981-07-07

Relatively dilute aqueous solutions of ethanol are concentrated by passage through a bed of a crystalline silica polymorph, such as silicalite, to adsorb the ethanol with residual dilute feed in contact with the bed, which is displaced by passing concentrated aqueous ethanol through the bed without displacing the adsorbed ethanol. A product concentrate is then obtained by removing the adsorbed ethanol from the bed together with at least a portion of the concentrated aqueous ethanol used as the displacer liquid. This process permits ethanol to be concentrated from dilute fermentation beers, which may contain from 6 to 10% ethanol, to obtain a concentrate product at very low energy cost having an ethanol concentration in excess of 95%, such as a concentration of from 98 to 99.5%.

Agar dilution and agar screen with cefoxitin and oxacillin: what is known and what is unknown in detection of meticillin-resistant Staphylococcus aureus.

PubMed

Perez, Leandro Reus Rodrigues; Dias, Cícero; d'Azevedo, Pedro Alves

2008-08-01

In this study we evaluated the performance of the oxacillin agar screen test, and agar dilution tests using cefoxitin and oxacillin antimicrobials, to detect meticillin resistance in Staphylococcus aureus isolates. The presence of the mecA gene, detected by PCR, was used as the standard to which agar screen and agar dilution tests were compared. The best performance was obtained using the agar dilution test (99.4 % accuracy) with breakpoints of 4 mug ml(-1) for oxacillin and 8 mug ml(-1) for cefoxitin, and using the oxacillin agar screen test. Also, a strong correlation between MIC values of cefoxitin and oxacillin permits the use of either drug for detection of meticillin resistance.

Biodiesel production from Scenedesmus bijuga grown in anaerobically digested food wastewater effluent.

PubMed

Shin, Dong Yun; Cho, Hyun Uk; Utomo, Joseph Christian; Choi, Yun-Nam; Xu, Xu; Park, Jong Moon

2015-05-01

Microalgae, Scenedesmus bijuga, was cultivated in anaerobically digested food wastewater effluent (FWE) to treat the wastewater and produce biodiesel simultaneously. Three different mixing ratios with municipal wastewater were compared for finding out proper dilution ratio in biodiesel production. Of these, 1/20 diluted FWE showed the highest biomass production (1.49 g/L). Lipid content was highest in 1/10 diluted FWE (35.06%), and the lipid productivity showed maximum value in 1/20 diluted FWE (15.59 mg/L/d). Nutrient removal was also measured in the cultivation. FAME compositions were mainly composed of C16-C18 (Over 98.94%) in S. bijuga. In addition, quality of FAMEs was evaluated by Cetane Number (CN) and Bis-allylic Position Equivalent (BAPE). Copyright © 2015. Published by Elsevier Ltd.

Assessment of a bedside test for N-terminal pro B-type natriuretic peptide (NT-proBNP) to differentiate cardiac from non-cardiac causes of pleural effusion in cats.

PubMed

Wurtinger, Gabriel; Henrich, Estelle; Hildebrandt, Nicolai; Wiedemann, Nicola; Schneider, Matthias; Hassdenteufel, Esther

2017-12-20

Cats with pleural effusion represent common emergencies in small animal practice. The aim of this prospective study was to investigate the diagnostic ability of a point-of-care ELISA (POC-ELISA) for the measurement of N-terminal pro B-type natriuretic peptide (NT-proBNP) to differentiate cardiac from non-cardiac disease in cats with pleural effusion. The sample material for use of this rapid test was either plasma or diluted pleural effusion. Twenty cats with moderate to severe pleural effusion were prospectively recruited. The cats were grouped into two groups, with or without congestive heart failure (CHF; N-CHF), after complete work-up. Blood and effusion were collected in EDTA tubes. Plasma and pleural effusion supernatants were transferred into stabilizer tubes and frozen. POC-ELISA for NT-proBNP was performed with plasma and diluted effusion (1:1). Quantitative NT-proBNP measurement was performed in plasma and diluted and undiluted effusions. Six cats were assigned to the CHF group. Of the 14 cats in the N-CHF group, 6 had concurrent cardiac abnormalities that were not responsible for the effusion. For the detection of CHF, the test displayed respective sensitivities and specificities of 100% and 79% in plasma and 100% and 86% in diluted pleural fluid. Receiver operating characteristic (ROC) analysis for quantitative NT-proBNP measurement of plasma and diluted and undiluted pleural effusions displayed areas under the curve of 0.98, sensitivities of 100% and specificities of 86%. The optimum cut-off was calculated at 399 pmol/l in plasma and 229 pmol/l in the diluted effusion and 467 pmol/l in the undiluted effusion. POC-ELISA for NT-proBNP in both plasma and diluted pleural effusion was suitable to differentiate cardiac from non-cardiac causes of feline pleural effusion. According to our results, use of pleural effusion is feasible, but dilution of the effusion before measurement seems to improve specificity.

Using the tracer-dilution discharge method to develop streamflow records for ice-affected streams in Colorado

USGS Publications Warehouse

Capesius, Joseph P.; Sullivan, Joseph R.; O'Neill, Gregory B.; Williams, Cory A.

2005-01-01

Accurate ice-affected streamflow records are difficult to obtain for several reasons, which makes the management of instream-flow water rights in the wintertime a challenging endeavor. This report documents a method to improve ice-affected streamflow records for two gaging stations in Colorado. In January and February 2002, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, conducted an experiment using a sodium chloride tracer to measure streamflow under ice cover by the tracer-dilution discharge method. The purpose of this study was to determine the feasibility of obtaining accurate ice-affected streamflow records by using a sodium chloride tracer that was injected into the stream. The tracer was injected at two gaging stations once per day for approximately 20 minutes for 25 days. Multiple-parameter water-quality sensors at the two gaging stations monitored background and peak chloride concentrations. These data were used to determine discharge at each site. A comparison of the current-meter streamflow record to the tracer-dilution streamflow record shows different levels of accuracy and precision of the tracer-dilution streamflow record at the two sites. At the lower elevation and warmer site, Brandon Ditch near Whitewater, the tracer-dilution method overestimated flow by an average of 14 percent, but this average is strongly biased by outliers. At the higher elevation and colder site, Keystone Gulch near Dillon, the tracer-dilution method experienced problems with the tracer solution partially freezing in the injection line. The partial freezing of the tracer contributed to the tracer-dilution method underestimating flow by 52 percent at Keystone Gulch. In addition, a tracer-pump-reliability test was conducted to test how accurately the tracer pumps can discharge the tracer solution in conditions similar to those used at the gaging stations. Although the pumps were reliable and consistent throughout the 25-day study period, the pumps underdischarged the tracer by 5.8-15.9 percent as compared to the initial pumping rate setting, which may explain some of the error in the tracer-dilution streamflow record as compared to current-meter streamflow record.

Media and dilution procedures tested to minimize handling effects on human, rabbit, and bull sperm for computer-assisted sperm analysis (CASA).

PubMed

Farrell, P B; Foote, R H; McArdle, M M; Trouern-Trend, V L; Tardif, A L

1996-01-01

Proper handling of semen prior to computer-assisted sperm analysis (CASA) is critical if the analysis is to be representative of the fresh sample. The effects of diluting medium or dilution and holding time before CASA on multiple sperm characteristics were studied. Four replicates of unselected semen samples from each of eight human donors were diluted with phosphate-buffered saline (PBS)-glucose plus bovine serum albumin (BSA), with Tyrode's albumen lactate pyruvate (TALP), and with high-potassium TALP (K-TALP) to a concentration of approximately 25 x 10(6) sperm/ml. The diluted semen was held for 0, 1, and 2 hours at approximately 30 degrees C before CASA, with little difference between the three diluents in all 12 variables measured. There was a decline of 3-6% in the proportion of motile sperm over a 2-hour period (P < 0.05). Donors were the largest source of differences (P < 0.05). Rabbit sperm (five bucks, four ejaculates per buck) were processed in a manner similar to that of the human sperm. There was a major effect of media. The average percentages of motile sperm over 2 hours in TALP, K-TALP, and PBS were 76, 42, and 29%, respectively (P < 0.05), with a decline of only 3% in TALP during the 2 hours. Hyperactivity and other characteristics were affected by treatment. Donors were a large source of variation. Bull semen (10 bulls, two ejaculates per bull) either was not diluted or diluted with TALP 2x or 4x and held for 0, 1, and 2 hours at 30 degrees C. It was then diluted to 25 x 10(6) sperm/ml with TALP. There was little change in most sperm characteristics in any treatment during the first hour, although many of the changes were statistically significant. The percentage of motile sperm in undiluted semen declined from 87% to 82% over 2 hours. Modified TALP was a suitable medium for sperm from all three species, and a simple PBS-glucose-BSA medium can be used for human sperm.

Use of a novel radiometric method to assess the inhibitory effect of donepezil on acetylcholinesterase activity in minimally diluted tissue samples

PubMed Central

Kikuchi, Tatsuya; Okamura, Toshimitsu; Arai, Takuya; Obata, Takayuki; Fukushi, Kiyoshi; Irie, Toshiaki; Shiraishi, Tetsuya

2010-01-01

Background and purpose: Cholinesterase inhibitors have been widely used for the treatment of patients with dementia. Monitoring of the cholinesterase activity in the blood is used as an indicator of the effect of the cholinesterase inhibitors in the brain. The selective measurement of cholinesterase with low tissue dilution is preferred for accurate monitoring; however, the methods have not been established. Here, we investigated the effect of tissue dilution on the action of cholinesterase inhibitors using a novel radiometric method with selective substrates, N-[14C]methylpiperidin-4-yl acetate ([14C]MP4A) and (R)-N-[14C]methylpiperidin-3-yl butyrate ([14C]MP3B_R), for AChE and butyrylcholinesterase (BChE) respectively. Experimental approach: We investigated the kinetics of hydrolysis of [14C]-MP4A and [14C]-MP3B_R by cholinesterases, and evaluated the selectivity of [14C]MP4A and [14C]MP3B_R for human AChE and BChE, respectively, compared with traditional substrates. Then, IC50 values of cholinesterase inhibitors in minimally diluted and highly diluted tissues were measured with [14C]MP4A and [14C]MP3B_R. Key results: AChE and BChE activities were selectively measured as the first-order hydrolysis rates of [14C]-MP4A and [14C]MP3B_R respectively. The AChE selectivity of [14C]MP4A was an order of magnitude higher than traditional substrates used for the AChE assay. The IC50 values of specific AChE and BChE inhibitors, donepezil and ethopropazine, in 1.2-fold diluted human whole blood were much higher than those in 120-fold diluted blood. In addition, the IC50 values of donepezil in monkey brain were dramatically decreased as the tissue was diluted. Conclusions and implications: This method would effectively monitor the activity of cholinesterase inhibitors used for therapeutics, pesticides and chemical warfare agents. PMID:20401964

Separation processes using expulsion from dilute supercritical solutions

DOEpatents

Cochran, Jr., Henry D.

1993-01-01

A process for separating isotopes as well as other mixtures by utilizing the behavior of dilute repulsive or weakly attractive elements of the mixtures as the critical point of the solvent is approached.

40 CFR 1065.245 - Sample flow meter for batch sampling.

Code of Federal Regulations, 2011 CFR

2011-07-01

... POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.245... difference between a diluted exhaust sample flow meter and a dilution air meter to calculate raw exhaust flow...

40 CFR 1065.245 - Sample flow meter for batch sampling.

Code of Federal Regulations, 2014 CFR

2014-07-01

... POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.245... difference between a diluted exhaust sample flow meter and a dilution air meter to calculate raw exhaust flow...

40 CFR 1065.245 - Sample flow meter for batch sampling.

Code of Federal Regulations, 2013 CFR

2013-07-01

... POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.245... difference between a diluted exhaust sample flow meter and a dilution air meter to calculate raw exhaust flow...

40 CFR 1065.245 - Sample flow meter for batch sampling.

Code of Federal Regulations, 2012 CFR

2012-07-01

... POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.245... difference between a diluted exhaust sample flow meter and a dilution air meter to calculate raw exhaust flow...

Anomalous Capacitance Maximum of the Glassy Carbon-Ionic Liquid Interface through Dilution with Organic Solvents.

PubMed

Bozym, David J; Uralcan, Betül; Limmer, David T; Pope, Michael A; Szamreta, Nicholas J; Debenedetti, Pablo G; Aksay, Ilhan A

2015-07-02

We use electrochemical impedance spectroscopy to measure the effect of diluting a hydrophobic room temperature ionic liquid with miscible organic solvents on the differential capacitance of the glassy carbon-electrolyte interface. We show that the minimum differential capacitance increases with dilution and reaches a maximum value at ionic liquid contents near 5-10 mol% (i.e., ∼1 M). We provide evidence that mixtures with 1,2-dichloroethane, a low-dielectric constant solvent, yield the largest gains in capacitance near the open circuit potential when compared against two traditional solvents, acetonitrile and propylene carbonate. To provide a fundamental basis for these observations, we use a coarse-grained model to relate structural variations at the double layer to the occurrence of the maximum. Our results reveal the potential for the enhancement of double-layer capacitance through dilution.

Semiquantitative determination of mesophilic, aerobic microorganisms in cocoa products using the Soleris NF-TVC method.

PubMed

Montei, Carolyn; McDougal, Susan; Mozola, Mark; Rice, Jennifer

2014-01-01

The Soleris Non-fermenting Total Viable Count method was previously validated for a wide variety of food products, including cocoa powder. A matrix extension study was conducted to validate the method for use with cocoa butter and cocoa liquor. Test samples included naturally contaminated cocoa liquor and cocoa butter inoculated with natural microbial flora derived from cocoa liquor. A probability of detection statistical model was used to compare Soleris results at multiple test thresholds (dilutions) with aerobic plate counts determined using the AOAC Official Method 966.23 dilution plating method. Results of the two methods were not statistically different at any dilution level in any of the three trials conducted. The Soleris method offers the advantage of results within 24 h, compared to the 48 h required by standard dilution plating methods.

Screening fungicides for use in fish culture: Evaluation of the agar plug transfer, cellophane transfer, and agar dilution methods

USGS Publications Warehouse

Bailey, Tom A.

1983-01-01

The reliability, reproducibility, and usefulness of three screening methods -- the cellophane transfer, the agar plug transfer, and the agar dilution -- to screen aquatic fungicides were evaluated. Achlya flagellata and Saprolegnia hypogyna were exposed to 1, 10, and 100 mg/L of malachite green to test each method. The cellophane transfer and agar plug transfer techniques had similar reliability and reproducibility in rating fungicidal activity, and were both superior to the agar dilution technique. The agar plug transfer and agar dilution techniques adequately projected in vivo activity of malachite green, but the cellophane transfer technique overestimated its activity. Overall, the agar plug transfer technique most accurately rated the activity of malachite green and was the easiest test to perform. It therefore appears to be the method of choice for testing aquatic fungicides.

Dilution cycle control for an absorption refrigeration system

DOEpatents

Reimann, Robert C.

1984-01-01

A dilution cycle control system for an absorption refrigeration system is disclosed. The control system includes a time delay relay for sensing shutdown of the absorption refrigeration system and for generating a control signal only after expiration of a preselected time period measured from the sensed shutdown of the absorption refrigeration system, during which the absorption refrigeration system is not restarted. A dilution cycle for the absorption refrigeration system is initiated in response to generation of a control signal by the time delay relay. This control system is particularly suitable for use with an absorption refrigeration system which is frequently cycled on and off since the time delay provided by the control system prevents needless dilution of the absorption refrigeration system when the system is turned off for only a short period of time and then is turned back on.

Pinch-off dynamics, extensional viscosity and relaxation time of dilute and ultradilute aqueous polymer solutions

NASA Astrophysics Data System (ADS)

Biagioli, Madeleine; Dinic, Jelena; Jimenez, Leidy Nallely; Sharma, Vivek

Free surface flows and drop formation processes present in printing, jetting, spraying, and coating involve the development of columnar necks that undergo spontaneous surface-tension driven instability, thinning, and pinch-off. Stream-wise velocity gradients that arise within the thinning neck create and extensional flow field, which induces micro-structural changes within complex fluids that contribute elastic stresses, changing the thinning and pinch-off dynamics. In this contribution, we use dripping-onto-substrate (DoS) extensional rheometry technique for visualization and analysis of the pinch-off dynamics of dilute and ultra-dilute aqueous polyethylene oxide (PEO) solutions. Using a range of molecular weights, we study the effect of both elasticity and finite extensibility. Both effective relaxation time and the transient extensional viscosity are found to be strongly concentration-dependent even for highly dilute solutions.

Transverse mixing of conservative and reactive tracers in porous media: Quantification through the concepts of flux-related and critical dilution indices

NASA Astrophysics Data System (ADS)

Chiogna, Gabriele; Cirpka, Olaf A.; Grathwohl, Peter; Rolle, Massimo

2011-02-01

The correct quantification of mixing is of utmost importance for modeling reactive transport in porous media and for assessing the fate and transport of contaminants in the subsurface. An appropriate measure of mixing in heterogeneous porous formations should correctly capture the effects on mixing intensity of various processes at different scales, such as local dispersion and the mixing enhancement due to heterogeneities. In this work, we use the concept of flux-related dilution index as a measure of transverse mixing. This quantity expresses the dilution of the mass flux of a conservative tracer solution over the total discharge of the system, and is particularly suited to address problems where a compound is continuously injected into the domain. We focus our attention on two-dimensional systems under steady state flow conditions and investigate both conservative and reactive transport in homogeneous and heterogeneous porous media at different scales. For mixing-controlled reactive systems, we introduce and illustrate the concept of critical dilution index, which represents the amount of mixing required for complete degradation of a continuously emitted plume undergoing decay upon mixing with ambient water. We perform two-dimensional numerical experiments at bench and field scales in homogeneous and heterogeneous conductivity fields. These numerical simulations show that the flux-related dilution index quantifies mixing and that the concept of critical dilution index is a useful measure to relate the mixing of conservative tracers to mixing-controlled degradation of reactive compounds.

Dilution of protein-surfactant complexes: a fluorescence study.

PubMed

Azadi, Glareh; Chauhan, Anuj; Tripathi, Anubhav

2013-09-01

Dilution of protein-surfactant complexes is an integrated step in microfluidic protein sizing, where the contribution of free micelles to the overall fluorescence is reduced by dilution. This process can be further improved by establishing an optimum surfactant concentration and quantifying the amount of protein based on the fluorescence intensity. To this end, we study the interaction of proteins with anionic sodium dodecyl sulfate (SDS) and cationic hexadecyl trimethyl ammonium bromide (CTAB) using a hydrophobic fluorescent dye (sypro orange). We analyze these interactions fluourometrically with bovine serum albumin, carbonic anhydrase, and beta-galactosidase as model proteins. The fluorescent signature of protein-surfactant complexes at various dilution points shows three distinct regions, surfactant dominant, breakdown, and protein dominant region. Based on the dilution behavior of protein-surfactant complexes, we propose a fluorescence model to explain the contribution of free and bound micelles to the overall fluorescence. Our results show that protein peak is observed at 3 mM SDS as the optimum dilution concentration. Furthermore, we study the effect of protein concentration on fluorescence intensity. In a single protein model with a constant dye quantum yield, the peak height increases with protein concentration. Finally, addition of CTAB to the protein-SDS complex at mole fractions above 0.1 shifts the protein peak from 3 mM to 4 mM SDS. The knowledge of protein-surfactant interactions obtained from these studies provides significant insights for novel detection and quantification techniques in microfluidics. © 2013 The Protein Society.

Growth of Carrot and Tomato from Oxamyl-coated Seed and Control of Meloidogyne hapla.

PubMed

Townshend, J L

1990-04-01

Oxamyl was coated on carrot (Daucus carota L. cv. Spartan Fancy-80) and tomato (Lycopersicon esculentum Mill. cv. Glamour) seeds with a polymer sticker for the control of Meloidogyne hapla. The sticker diluted in water 1:1 delayed carrot seedling emergence. Oxamyl at 40 mg/ml in a 1:5 dilution of sticker lowered the rate of carrot seedling emergence until day 13 and plant growth until day 28. Oxamyl at 20 or 40 mg/ml in a 1:5 dilution of sticker on carrot seeds planted in M. hapla-infested muck soil resulted in fewer galled tap roots and fewer galls per root system 4 weeks after planting. Tap root lengths were greater than those of the control. Tomato seedling emergence was delayed and top and root weights were reduced, relative to the control, at 25 days by the sticker diluted 1:1 to 1:3. Oxamyl at 20 or 40 mg/ml in a 1:5 diluted sticker delayed tomato seedling emergence. Top weights of tomato seedlings from seeds coated with 20 mg/ml of oxamyl in a 1:5 diluted sticker planted in a silt loam were greater than control top weights at 4 and 6 weeks. Root weights were greater than those of the control only at 4 weeks. There were fewer galls per gram of root on seedlings from oxamyl-coated seeds and fewer juveniles per pot of soil, relative to the controls, only at 4 weeks.

Characterization of a multilayer aquifer using open well dilution tests.

PubMed

West, L Jared; Odling, Noelle E

2007-01-01

An approach to characterization of multilayer aquifer systems using open well borehole dilution is described. The approach involves measuring observation well flow velocities while a nearby extraction well is pumped by introducing a saline tracer into observation wells and collecting dilution vs. depth profiles. Inspection of tracer profile evolution allows discrete permeable layers within the aquifer to be identified. Dilution profiles for well sections between permeable layers are then converted into vertical borehole flow velocities and their evolution, using an analytic solution to the advection-dispersion equation applied to borehole flow. The dilution approach is potentially able to measure much smaller flow velocities that would be detectable using flowmeters. Vertical flow velocity data from the observation wells are then matched to those generated using a hydraulic model of the aquifer system, "shorted" by the observation wells, to yield the hydraulic properties of the constituent layers. Observation well flow monitoring of pumping tests represents a cost-effective alternative or preliminary approach to pump testing each layer of a multilayer aquifer system separately using straddle packers or screened wells and requires no prior knowledge of permeable layer depths and thicknesses. The modification described here, of using tracer dilution rather than flowmeter logging to obtain well flow velocities, allows the approach to be extended to greater well separations, thus characterizing a larger volume of the aquifer. An example of the application of this approach to a multilayer Chalk Aquifer in Yorkshire, Northeast England, is presented.

Impact of varying area of polluting surface materials on perceived air quality.

PubMed

Sakr, W; Knudsen, H N; Gunnarsen, L; Haghighat, F

2003-06-01

A laboratory study was performed to investigate the impact of the concentration of pollutants in the air on emissions from building materials. Building materials were placed in ventilated test chambers. The experimental set-up allowed the concentration of pollution in the exhaust air to be changed either by diluting exhaust air with clean air (changing the dilution factor) or by varying the area of the material inside the chamber when keeping the ventilation rate constant (changing the area factor). Four different building materials and three combinations of two or three building materials were studied in ventilated small-scale test chambers. Each individual material and three of their combinations were examined at four different dilution factors and four different area factors. An untrained panel of 23 subjects assessed the air quality from the chambers. The results show that a certain increase in dilution improves the perceived air quality more than a similar decrease in area. The reason for this may be that the emission rate of odorous pollutants increases when the concentration in the chamber decreases. The results demonstrate that, in some cases the effect of increased ventilation on the air quality may be less than expected from a simple dilution model.

Path selection rules for droplet trains in single-lane microfluidic networks

NASA Astrophysics Data System (ADS)

Amon, A.; Schmit, A.; Salkin, L.; Courbin, L.; Panizza, P.

2013-07-01

We investigate the transport of periodic trains of droplets through microfluidic networks having one inlet, one outlet, and nodes consisting of T junctions. Variations of the dilution of the trains, i.e., the distance between drops, reveal the existence of various hydrodynamic regimes characterized by the number of preferential paths taken by the drops. As the dilution increases, this number continuously decreases until only one path remains explored. Building on a continuous approach used to treat droplet traffic through a single asymmetric loop, we determine selection rules for the paths taken by the drops and we predict the variations of the fraction of droplets taking these paths with the parameters at play including the dilution. Our results show that as dilution decreases, the paths are selected according to the ascending order of their hydrodynamic resistance in the absence of droplets. The dynamics of these systems controlled by time-delayed feedback is complex: We observe a succession of periodic regimes separated by a wealth of bifurcations as the dilution is varied. In contrast to droplet traffic in single asymmetric loops, the dynamical behavior in networks of loops is sensitive to initial conditions because of extra degrees of freedom.

One-step pretreatment of yellow poplar biomass using peracetic acid to enhance enzymatic digestibility.

PubMed

Lee, Hyeong Rae; Kazlauskas, Romas J; Park, Tai Hyun

2017-09-22

Pretreatment of biomass with dilute acid requires high temperatures of >160 °C to remove xylan and does not remove lignin. Here we report that the addition of peracetic acid, a strong oxidant, to mild dilute acid pretreatment reduces the temperature requirement to only 120 °C. Pretreatment of yellow poplar with peracetic acid (300 mM, 2.3 wt%) and dilute sulfuric acid (100 mM, 1.0 wt%) at 120 °C for 5 min removed 85.7% of the xylan and 90.4% of the lignin leaving a solid consisting of 75.6% glucan, 6.0% xylan and 4.7% lignin. Low enzyme loadings of 5 FPU/g glucan and 10 pNPGU/g glucan converted this solid to glucose with an 84.0% yield. This amount of glucose was 2.5 times higher than with dilute acid-pretreated solid and 13.8 times higher than with untreated yellow poplar. Thus, the addition of peracetic acid, easily generated from acetic acid and hydrogen peroxide, dramatically increases the effectiveness of dilute acid pretreatment of biomass.

Warming and fertilization alter the dilution effect of host diversity on disease severity.

PubMed

Liu, Xiang; Lyu, Shengman; Zhou, Shurong; Bradshaw, Corey J A

2016-07-01

An essential ecosystem service is the dilution effect of biodiversity on disease severity, yet we do not fully understand how this relationship might change with continued climate warming and ecosystem degradation. We designed removal experiments in natural assemblages of Tibetan alpine meadow vegetation by manipulating plot-level plant diversity to investigate the relationship between different plant biodiversity indices and foliar fungal pathogen infection, and how artificial fertilization and warming affect this relationship. Although pathogen group diversity increased with host species richness, disease severity decreased as host diversity rose (dilution effect). The dilution effect of phylogenetic diversity on disease held across different levels of host species richness (and equal abundances), meaning that the effect arises mainly in association with enhanced diversity itself rather than from shifting abundances. However, the dilution effect was weakened by fertilization. Among indices, phylogenetic diversity was the most parsimonious predictor of infection severity. Experimental warming and fertilization shifted species richness to the most supported predictor. Compared to planting experiments where artificial communities are constructed from scratch, our removal experiment in natural communities more realistically demonstrate that increasing perturbation adjusts natural community resistance to disease severity. © 2016 by the Ecological Society of America.

Designing and Interpreting Limiting Dilution Assays: General Principles and Applications to the Latent Reservoir for Human Immunodeficiency Virus-1.

PubMed

Rosenbloom, Daniel I S; Elliott, Oliver; Hill, Alison L; Henrich, Timothy J; Siliciano, Janet M; Siliciano, Robert F

2015-12-01

Limiting dilution assays are widely used in infectious disease research. These assays are crucial for current human immunodeficiency virus (HIV)-1 cure research in particular. In this study, we offer new tools to help investigators design and analyze dilution assays based on their specific research needs. Limiting dilution assays are commonly used to measure the extent of infection, and in the context of HIV they represent an essential tool for studying latency and potential curative strategies. Yet standard assay designs may not discern whether an intervention reduces an already miniscule latent infection. This review addresses challenges arising in this setting and in the general use of dilution assays. We illustrate the major statistical method for estimating frequency of infectious units from assay results, and we offer an online tool for computing this estimate. We recommend a procedure for customizing assay design to achieve desired sensitivity and precision goals, subject to experimental constraints. We consider experiments in which no viral outgrowth is observed and explain how using alternatives to viral outgrowth may make measurement of HIV latency more efficient. Finally, we discuss how biological complications, such as probabilistic growth of small infections, alter interpretations of experimental results.

Detection of Toxoplasma oocysts from soil by modified sucrose flotation and PCR methods.

PubMed

Matsuo, Junji; Kimura, Daisuke; Rai, Shiba Kumar; Uga, Shoji

2004-06-01

A detection method of Toxoplasma gondii oocysts from soil was evaluated using the sucrose flotation technique with modification involving addition of 0.1% gelatin into washing and floating solutions. PCR was performed on untreated samples and after treatment with polyvinylpyrrolidone (PVP), heating and cooling, and NaCl. The addition of gelatin in the sucrose solution yielded a higher number of oocysts. A very thin band was observed when DNA extract was diluted to 1:1024, indicating the presence of PCR inhibitor in the soil. PCR performed on untreated DNA, on PVP-treated, and on PVP-treated with heating and cooling without added bovine serum albumin (BSA) showed a band only at higher dilutions (1:1024 and 1:512) but at a much lower dilution (1:8) with BSA. In contrast, DNA treated with all three agents showed a band at a much lower dilution (1:64), even without added BSA, and no dilution was required when BSA was added. The PCR inhibitors present in the soil were removed by employing various treatment procedures during DNA extraction, and BSA in PCR. Furthermore, the detection limit with the method was 1 oocyst/g of soil, indicating that this method is useful in epidemiological studies.

Effects of iodinated contrast agent, xylocaine and gadolinium concentration on the signal emitted in magnetic resonance arthrography: a samples study*

PubMed Central

da Silva, Yvana Lopes Pinheiro; Costa, Rita Zanlorensi Visneck; Pinho, Kátia Elisa Prus; Ferreira, Ricardo Rabello; Schuindt, Sueliton Miyamoto

2015-01-01

Objective To investigate the effects of dilution of paramagnetic contrast agent with iodinated contrast and xylocaine on the signal intensity during magnetic resonance arthrography, and to improve the paramagnetic contrast agent concentration utilized in this imaging modality. Materials and Methods Samples specially prepared for the study with three different concentrations of paramagnetic contrast agent diluted in saline, iodinated contrast agent and xylocaine were imaged with fast spin echo T1-weighted sequences with fat saturation. The samples were placed into flasks and graphical analysis of the signal intensity was performed as a function of the paramagnetic contrast concentration. Results As compared with samples of equal concentrations diluted only with saline, the authors have observed an average signal intensity decrease of 20.67% for iodinated contrast agent, and of 28.34% for xylocaine. However, the increased gadolinium concentration in the samples caused decrease in signal intensity with all the dilutions. Conclusion Minimizing the use of iodinated contrast media and xylocaine and/or the use of a gadolinium concentration of 2.5 mmol/L diluted in saline will improve the sensitivity of magnetic resonance arthrography. PMID:25987746

Comparison of Anaerobic Susceptibility Results Obtained by Different Methods

PubMed Central

Rosenblatt, J. E.; Murray, P. R.; Sonnenwirth, A. C.; Joyce, J. L.

1979-01-01

Susceptibility tests using 7 antimicrobial agents (carbenicillin, chloramphenicol, clindamycin, penicillin, cephalothin, metronidazole, and tetracycline) were run against 35 anaerobes including Bacteroides fragilis (17), other gram-negative bacilli (7), clostridia (5), peptococci (4), and eubacteria (2). Results in triplicate obtained by the microbroth dilution method and the aerobic modification of the broth disk method were compared with those obtained with an agar dilution method using Wilkins-Chalgren agar. Media used in the microbroth dilution method included Wilkins-Chalgren broth, brain heart infusion broth, brucella broth, tryptic soy broth, thioglycolate broth, and Schaedler's broth. A result differing by more than one dilution from the Wilkins-Chalgren agar result was considered a discrepancy, and when there was a change in susceptibility status this was termed a significant discrepancy. The microbroth dilution method using Wilkins-Chalgren broth and thioglycolate broth produced the fewest total discrepancies (22 and 24, respectively), and Wilkins-Chalgren broth, thioglycolate, and Schaedler's broth had the fewest significant discrepancies (6, 5, and 5, respectively). With the broth disk method, there were 15 significant discrepancies, although half of these were with tetracycline, which was the antimicrobial agent associated with the highest number of significant discrepancies (33), considering all of the test methods and media. PMID:464560

Review of the use of high potencies in basic research on homeopathy.

PubMed

Clausen, Jürgen; van Wijk, Roeland; Albrecht, Henning

2011-10-01

The HomBRex database includes details of about 1500 basic research experiments in homeopathy. A general overview on the experiments listed in the HomBRex database is presented, focusing on high dilutions and the different settings in which those were used. Though often criticised, many experiments with remedies diluted beyond Avogadro's number demonstrate specific effects. A total of 830 experiments employing high potencies was found; in 745 experiments of these (90%), at least one positive result was reported. Animals represent the most often used model system (n=371), followed by plants (n=201), human material (n=92), bacteria and viruses (n=37) and fungi (n=32). Arsenicum album (Ars.) is the substance most often applied (n=101), followed by Sulphur (Sulph.) and Thuja (Thuj.) (n=65 and 48, respectively). Proving, prophylactic and therapeutic study designs have all been used and appear appropriate for homeopathy basic research using high dilutions. The basic research data set to support specific effects unique to high dilutions and opposite to those observed with low dilutions is, to date, insufficient. Copyright © 2011 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

The effect of calcium hydroxide, alkali dilution and calcium concentration in mitigating the alkali silica reaction using palm oil fuel ash

NASA Astrophysics Data System (ADS)

Asrah, Hidayati; Mirasa, Abdul Karim; Bolong, Nurmin

2018-02-01

This study investigated the mechanism of how POFA mitigated the ASR expansion. Two types of POFA; the UPOFA and GPOFA with different fineness were used to replace the cement at 20% and 40% and their effects on the mortar bar expansion, calcium hydroxide, alkali dilution, and calcium concentration were investigated. The results showed that UPOFA has a significant ability to mitigate the ASR, even at a lower level of replacement (20%) compared to GPOFA. The mechanism of UPOFA in mitigating the ASR expansion was through a reduction in the calcium hydroxide content, which produced low calcium concentration within the mortar pore solution. Low pore solution alkalinity signified that UPOFA had good alkali dilution effect. Meanwhile, a higher dosage of GPOFA was required to mitigate the ASR expansion. An increase in the pore solution alkalinity of GPOFA mortar indicated higher penetration of alkalis from the NaOH solution, which reduced the alkali dilution effect. However, this was compensated by the increase in the cement dilution effect at higher GPOFA replacement, which controlled the mortar bar expansion below the ASTM limit.

Separation processes using expulsion from dilute supercritical solutions

DOEpatents

Cochran, H.D. Jr.

1993-04-20

A process is described for separating isotopes as well as other mixtures by utilizing the behavior of dilute repulsive or weakly attractive elements of the mixtures as the critical point of the solvent is approached.

40 CFR 1066.140 - Diluted exhaust flow calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... whenever corrective action does not resolve a failure to meet the diluted exhaust flow verification (i.e... subsonic venturi flow meter, a long-radius ASME/NIST flow nozzle, a smooth approach orifice, a laminar flow...

40 CFR 1065.340 - Diluted exhaust flow (CVS) calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... initial CVS installation and whenever corrective action does not resolve a failure to meet the diluted... such as a subsonic venturi flow meter, a long-radius ASME/NIST flow nozzle, a smooth approach orifice...

40 CFR 1065.340 - Diluted exhaust flow (CVS) calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... initial CVS installation and whenever corrective action does not resolve a failure to meet the diluted... such as a subsonic venturi flow meter, a long-radius ASME/NIST flow nozzle, a smooth approach orifice...

40 CFR 1065.340 - Diluted exhaust flow (CVS) calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... initial CVS installation and whenever corrective action does not resolve a failure to meet the diluted... such as a subsonic venturi flow meter, a long-radius ASME/NIST flow nozzle, a smooth approach orifice...

Determination of 241Am in sediments by isotope dilution high resolution inductively coupled plasma mass spectrometry (ID HR ICP-MS).

PubMed

Agarande, M; Benzoubir, S; Bouisset, P; Calmet, D

2001-08-01

Trace levels (pg kg(-1)) of 241Am in sediments were determined by isotope dilution high resolution inductively coupled plasma mass spectrometry (ID HR ICP-MS) using a microconcentric nebulizer. 241Am was isolated from major elements like Ca and Fe by different selective precipitations. In further steps. Am was first separated from other transuranic elements and purified by anion exchange and extraction chromatography prior to the mass spectrometric measurements. The ID HR ICP-MS results are compared with isotope dilution alpha spectrometry.

Determination of the concentration of a Bryonia Dioica tincture by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Milea, Irimie; Culea, E.; Iliescu, T.; Milea, Janetta

1995-03-01

It was established a method based on Raman spectroscopy in order to control the content and concentration of homeopathic dilutions. Dilutions of a tincture of Bryonia Dioica in ethanol were prepared and investigated by Raman spectroscopy. The Raman line at 881 cm-1 was found to depend linearly versus the concentration of Bryonia Dioica. This permits to obtain a calibration curve that may be used to determine the concentration of Bryonia Dioica in ethanol. The method may be extended to determine the concentration of various homeopathic dilutions.

Effect of rapid warming of boar semen on sperm morphology and physiology.

PubMed

Bamba, K; Cran, D G

1985-09-01

The effect of rapid dilution (1:8 with BTS or 1:6.5 with KRP) and temperature change on sperm morphology and physiology were studied using boar spermatozoa pre-diluted in BF5 diluent. Rapid dilution of cold semen (5 degrees C) with a warm solution (37 degrees C) caused marked acrosomal changes which were most prominent in the anterior region. The acrosomal damage appeared to be caused mainly by rapid warming. In contrast to rapid cooling, rapid warming had little effect upon motility, glutamic-oxaloacetic transaminase release and respiration.

Suppression of Beneficial Mutations in Dynamic Microbial Populations

NASA Astrophysics Data System (ADS)

Bittihn, Philip; Hasty, Jeff; Tsimring, Lev S.

2017-01-01

Quantitative predictions for the spread of mutations in bacterial populations are essential to interpret evolution experiments and to improve the stability of synthetic gene circuits. We derive analytical expressions for the suppression factor for beneficial mutations in populations that undergo periodic dilutions, covering arbitrary population sizes, dilution factors, and growth advantages in a single stochastic model. We find that the suppression factor grows with the dilution factor and depends nontrivially on the growth advantage, resulting in the preferential elimination of mutations with certain growth advantages. We confirm our results by extensive numerical simulations.

Detailed mechanism of benzene oxidation

NASA Technical Reports Server (NTRS)

Bittker, David A.

1987-01-01

A detailed quantitative mechanism for the oxidation of benzene in both argon and nitrogen diluted systems is presented. Computed ignition delay time for argon diluted mixtures are in satisfactory agreement with experimental results for a wide range of initial conditions. An experimental temperature versus time profile for a nitrogen diluted oxidation was accurately matched and several concentration profiles were matched qualitatively. Application of sensitivity analysis has given approximate rate constant expressions for the two dominant heat release reactions, the oxidation of C6H5 and C5H5 radicals by molecular oxygen.

Basic research in homeopathy and ultra-high dilutions: what progress is being made?

PubMed

Betti, Lucietta; Trebbi, Grazia; Olioso, Debora; Marzotto, Marta; Bellavite, Paolo

2013-04-01

This report summarises the latest research developments in the field of high dilutions and homeopathy, as presented at the GIRI symposium of the leading international organisation of scientists in this field, in Florence, Italy in September 2012. The scientific community's early scepticism concerning the possible biological and pharmacological activity of highly diluted solutions, is giving way to a more open-minded attitude that no longer obstructs critical and experimental investigations in this emerging field of biomedicine. Copyright © 2013. Published by Elsevier Ltd.. All rights reserved.

In Situ Local Fracture Flow Measurement by the Double Packer Dilution Test

NASA Astrophysics Data System (ADS)

Englert, A.; Le Borgne, T.; Bour, O.; Klepikova, M.; Lavenant, N.

2011-12-01

For prediction of flow and transport in fractured media, prior estimation of the fracture network is essential, but challenging. Recent developments in hydraulic tomography have shown promising results for understanding connectivities between boreholes. However, as the hydraulic tomographic survey is typically based on the propagation of head only, it becomes a strongly non unique problem. To reduce the non uniqueness of tomographic surveys point conditioning has been found beneficial. Just as well, measurement of local flow in a fracture can serve as point conditioning for hydraulic and tracer tomographic surveys. Nevertheless, only few measurements of local fracture flow have been performed since this type of measurements implies several important technical issues. Dilution test in a packed off interval is a possible method for measuring fracture flow (e.g. Drost et al. 1968, Novakowski et al., 2005). However, a key issue for estimating flow with dilution tests is to ensure a full mixing of the tracer in the packed interval. This is typically done by including a mixing system within the packer. The design of such system can be challenging for deep wells and small diameters. Here, we propose a method where mixing is ensured by a recirculation loop including a surface tank. This method is adapted from the design proposed by Brouyere et al. (2008), who measured dilution in open wells. Dilution is quantified by measuring the concentration in the surface barrel as function of time. Together with the measurement of the circulating flow and the water filled volume in the surface barrel, the measured tracer dilution allows for calculation of the fracture flow. Since the method can be applied using a classical double packer system, it may provide a broader application of local flow measurements in heterogeneous media. We tested the approach on the Ploemeur fractured crystalline rock site. A one meter interval at depth 80 m with a single flowing fracture was isolated with a double packer dilution system. We performed a pumping test in the adjacent well. Different flow rates were estimated from the dilution curves for the different pumping rates in the adjacent well, showing a linear response. The obtained fracture flow rates provide important information on the flow geometry and connectivity between the two wells. Future joint interpretation of flow measurements, hydraulic head and tracer test data is expected to provide detailed insights in the flow and transport processes at the Ploemeur site. Drost, W., Klotz, D., Koch, A., Moser, H., Neumaier, F., Rauert, W.: Point dilution methods of investigating ground water flow by means of radioisotopes, Water. Resour. Res., 4(1), 1968. Novakowski, K., Bickerton, G., Lapcevic, P., Voralek, J., Ross, N.: Measurements of groundwater velocity in discrete rock fractures: Jour. Cont. Hydr., 82(1-2), 2006. Brouyere, S., Batlle-Aguilar, J., Goderniaux, P., Dassargues, A.: A new tracer technique for monitoring groundwater fluxes: The Finite Volume Point Dilution Method, Jour. Cont. Hydr., 95(3-4), 121-140, 2008.

Dilution and Mixing in transient velocity fields: a first-order analysis

NASA Astrophysics Data System (ADS)

Di Dato, Mariaines; de Barros, Felipe, P. J.; Fiori, Aldo; Bellin, Alberto

2017-04-01

An appealing remediation technique is in situ oxidation, which effectiveness is hampered by difficulties in obtaining good mixing of the injected oxidant with the contaminant, particularly when the contaminant plume is contained and therefore its deformation is physically constrained. Under such conditions (i.e. containment), mixing may be augmented by inducing temporal fluctuations of the velocity field. The temporal variability of the flow field may increase the deformation of the plume such that diffusive mass flux becomes more effective. A transient periodic velocity field can be obtained by an engineered sequence of injections and extractions from wells, which may serve also as a hydraulic barrier to confine the plume. Assessing the effectiveness of periodic flows to maximize solute mixing is a difficult task given the need to use a 3D setup and the large number of possible flow configurations that should be analyzed in order to identify the optimal one. This is the typical situation in which analytical solutions, though approximated, may assist modelers in screening possible alternative flow configurations such that solute dilution is maximized. To quantify dilution (i.e. a precondition that enables reactive mixing) we utilize the concept of the dilution index [1]. In this presentation, the periodic flow takes place in an aquifer with spatially variable hydraulic conductivity field which is modeled as a Stationary Spatial Random Function. We developed a novel first-order analytical solution of the dilution index under the hypothesis that the flow can be approximated as a sequence of steady state configurations with the mean velocity changing with time in intensity and direction. This is equivalent to assume that the characteristic time of the transient behavior is small compared to the period characterizing the change in time of the mean velocity. A few closed paths have been analyzed quantifying their effectiveness in enhancing dilution and thereby mixing between the resident contaminant and an oxidant. In particular, we considered three different flow configurations: (1) a "circular" pattern, in which the vector of the mean velocity rotates at a constant celerity; (2) a "shake" pattern, in which the velocity has a constant magnitude and changes direction alternatively leading to a "back and forth" type of movement and finally (3) a more general "shake and rotate" pattern, which combines the previous two configurations. The new analytical solution shows that dilution is affected by the configuration of the periodic mean flow. Results show that the dilution index increases when the rotation-shake configuration is adopted. In addition, the dilution index is augmented with the oscillation amplitude of the shake component. This analysis is useful to identify optimal flow configurations that may be approximately reproduced in the field and which efficiency may be checked more accurately by numerical simulations, thereby alleviating the computational burden by efficiently screening among alternative configurations. References [1] Kitanidis, P. K. (1994), The concept of the Dilution Index, Water Resour. Res., 30(7), 2011-2026, doi:10.1029/94WR00762.

Cluster Dynamics Modeling with Bubble Nucleation, Growth and Coalescence

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

de Almeida, Valmor F.; Blondel, Sophie; Bernholdt, David E.

The topic of this communication pertains to defect formation in irradiated solids such as plasma-facing tungsten submitted to helium implantation in fusion reactor com- ponents, and nuclear fuel (metal and oxides) submitted to volatile ssion product generation in nuclear reactors. The purpose of this progress report is to describe ef- forts towards addressing the prediction of long-time evolution of defects via continuum cluster dynamics simulation. The di culties are twofold. First, realistic, long-time dynamics in reactor conditions leads to a non-dilute di usion regime which is not accommodated by the prevailing dilute, stressless cluster dynamics theory. Second, long-time dynamics callsmore » for a large set of species (ideally an in nite set) to capture all possible emerging defects, and this represents a computational bottleneck. Extensions beyond the dilute limit is a signi cant undertaking since no model has been advanced to extend cluster dynamics to non-dilute, deformable conditions. Here our proposed approach to model the non-dilute limit is to monitor the appearance of a spatially localized void volume fraction in the solid matrix with a bell shape pro le and insert an explicit geometrical bubble onto the support of the bell function. The newly cre- ated internal moving boundary provides the means to account for the interfacial ux of mobile species into the bubble, and the growth of bubbles allows for coalescence phenomena which captures highly non-dilute interactions. We present a preliminary interfacial kinematic model with associated interfacial di usion transport to follow the evolution of the bubble in any number of spatial dimensions and any number of bubbles, which can be further extended to include a deformation theory. Finally we comment on a computational front-tracking method to be used in conjunction with conventional cluster dynamics simulations in the non-dilute model proposed.« less

Short communication: milk output in llamas (Lama glama) in relation to energy intake and water turnover measured by an isotope dilution technique.

PubMed

Riek, A; Klinkert, A; Gerken, M; Hummel, J; Moors, E; Südekum, K-H

2013-03-01

Despite the fact that llamas have become increasingly popular as companion and farm animals in both Europe and North America, scientific knowledge on their nutrient requirements is scarce. Compared with other livestock species, relatively little is known especially about the nutrient and energy requirements for lactating llamas. Therefore, we aimed to measure milk output in llama dams using an isotope dilution technique and relate it to energy intakes at different stages of lactation. We also validated the dilution technique by measuring total water turnover (TWT) directly and comparing it with values estimated by the isotope dilution technique. Our study involved 5 lactating llama dams and their suckling young. Milk output and TWT were measured at 4 stages of lactation (wk 3, 10, 18, and 26 postpartum). The method involved the application of the stable hydrogen isotope deuterium ((2)H) to the lactating dam. Drinking water intake and TWT decreased significantly with lactation stage, whether estimated by the isotope dilution technique or calculated from drinking water and water ingested from feeds. In contrast, lactation stage had no effect on dry matter intake, metabolizable energy (ME) intake, or the milk water fraction (i.e., the ratio between milk water excreted and TWT). The ratios between TWT measured and TWT estimated (by isotope dilution) did not differ with lactation stage and were close to 100% in all measurement weeks, indicating that the D(2)O dilution technique estimated TWT with high accuracy and only small variations. Calculating the required ME intakes for lactation from milk output data and gross energy content of milk revealed that, with increasing lactation stage, ME requirements per day for lactation decreased but remained constant per kilogram of milk output. Total measured ME intakes at different stages of lactation were similar to calculated ME intakes from published recommendation models for llamas. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Evaluation of biocompatibility of sodium perborate and 30% hydrogen peroxide using the analysis of the adherence capacity and morphology of macrophages.

PubMed

Asfora, Kattyenne Kabbaz; Santos, Maria do Carmo Moreira da Silva; Montes, Marcos Antonio Japiassú Resende; de Castro, Célia Maria Machado Barbosa

2005-02-01

The purpose of this study was to evaluate the biocompatibility of the most used bleaching materials for pulpless teeth, sodium perborate and 30% hydrogen peroxide, in an experimental model of macrophages, through analysis of the adherence index and the cellular morphology. Inflammatory macrophages were obtained from peritoneal washed of Wistar rats. The evaluation of the adherence capacity of these cells to the plastic surface was conducted in Eppendorf tubes containing RPMI, after treatment with the bleaching agents diluted in 1:10, 1:100 and 1:1000 for 15 and 30 min, and incubation at 37 degrees C and humidified atmosphere of 5% CO(2) in air. The cellular morphology was verified after incubation of the cells treated with the bleaching agents in culture plaques and compared with normal cells in culture medium. Results showed that sodium perborate neither increased the adherence index, nor altered the cellular morphology when compared to the control group. The distribution, cellular morphology, cytoplasmatic and nuclear characteristics, reproduced the aspects observed in normal macrophages. However, the treatment with 30% hydrogen peroxide presented an increase in adherence index when compared to the control group (RPMI), in all dilutions, according to Mann-Whitney test (n=08 and p=0.001 for dilutions 1:10 and 1:100, and n=08 and p=0.004 for dilution 1:1000). The morphology of the cells treated with this product presented structural alterations proportionally greater, depending on the dilution of this bleaching agent, and even in the highest dilution (1:1000) the cells presented very evident alterations. This irreversible cellular damage as well as the elevation of the adherence index, characterizes the aggressive potential of 30% hydrogen peroxide, regardless of its dilution. Sodium perborate, on the other hand, showed biocompatibitity, since, no morphological nor functional alteration was observed in macrophages.

A Multilaboratory, Multicountry Study To Determine Bedaquiline MIC Quality Control Ranges for Phenotypic Drug Susceptibility Testing

PubMed Central

Cirillo, Daniela M.; Hoffner, Sven; Ismail, Nazir A.; Kaur, Devinder; Lounis, Nacer; Metchock, Beverly; Pfyffer, Gaby E.; Venter, Amour

2016-01-01

The aim of this study was to establish standardized drug susceptibility testing (DST) methodologies and reference MIC quality control (QC) ranges for bedaquiline, a diarylquinoline antimycobacterial, used in the treatment of adults with multidrug-resistant tuberculosis. Two tier-2 QC reproducibility studies of bedaquiline DST were conducted in eight laboratories using Clinical Laboratory and Standards Institute (CLSI) guidelines. Agar dilution and broth microdilution methods were evaluated. Mycobacterium tuberculosis H37Rv was used as the QC reference strain. Bedaquiline MIC frequency, mode, and geometric mean were calculated. When resulting data occurred outside predefined CLSI criteria, the entire laboratory data set was excluded. For the agar dilution MIC, a 4-dilution QC range (0.015 to 0.12 μg/ml) centered around the geometric mean included 95.8% (7H10 agar dilution; 204/213 observations with one data set excluded) or 95.9% (7H11 agar dilution; 232/242) of bedaquiline MICs. For the 7H9 broth microdilution MIC, a 3-dilution QC range (0.015 to 0.06 μg/ml) centered around the mode included 98.1% (207/211, with one data set excluded) of bedaquiline MICs. Microbiological equivalence was demonstrated for bedaquiline MICs determined using 7H10 agar and 7H11 agar but not for bedaquiline MICs determined using 7H9 broth and 7H10 agar or 7H9 broth and 7H11 agar. Bedaquiline DST methodologies and MIC QC ranges against the H37Rv M. tuberculosis reference strain have been established: 0.015 to 0.12 μg/ml for the 7H10 and 7H11 agar dilution MICs and 0.015 to 0.06 μg/ml for the 7H9 broth microdilution MIC. These methodologies and QC ranges will be submitted to CLSI and EUCAST to inform future research and provide guidance for routine clinical bedaquiline DST in laboratories worldwide. PMID:27654337

Compatibility of an Ultraselective Microcatheter and Epirubicin Loaded 300-500-μm DC Bead in Ex Vivo Study.

PubMed

Fukuoka, Yasushi; Tanaka, Toshihiro; Nishiofuku, Hideyuki; Sato, Takeshi; Kichikawa, Kimihiko

2015-10-01

The purpose of this study is to examine whether epirubicin loaded DC Bead 300-500 μm in size can pass through a 1.8-Fr ultraselective microcatheter in ex vivo study. Epirubicin (25 mg/1 mL) loaded 100-300 and 300-500 μm DC Bead were tested. Both sizes were diluted 5, 10, and 30 times using contrast material. Ultraselective microcatheter with the outer diameter of 1.8 Fr and the inner diameter of .017 inch (431.8 μm) was used. The diluted DC Bead was injected at a speed of 1 mL/min, and the pressure was continuously measured. The microspheres' shapes after ejection were observed by a stereomicroscope. The maximum pressure of contrast material alone was 8.40 ± 0.21 psi. The maximum pressure in 5, 10, and 30 times dilution groups of 100-300 μm were 9.67 ± 1.18, 9.25 ± 0.25, and 9.71 ± 0.28 psi, respectively, whereas 21.10 ± 10.2, 10.48 ± 2.14, 10.09 ± 0.37 psi, respectively in 300-500 μm groups. The maximum pressure in 5 times dilution group of 300-500 μm was significantly higher than the other groups (P < 0.05). In 300-500 μm, 4 of 10 measurements showed high pressure over 24 psi (the maximum value was 43.5 psi) in 5 times dilution group, whereas in 10 times and 30 times dilution groups, all measurements showed less than 12 psi. No damages of microspheres were found. Epirubicin loaded DC Bead 300-500 μm in size can pass through a 1.8-Fr ultraselective microcatheter. To avoid high resistance due to microspheres' aggregation, dilution more than 10 times is needed.

[Comparison of single-indicator thermodilution versus gravimetric measurement in determination of extra-vascular lung water in dogs with acute respiratory distress syndrome].

PubMed

Shen, Ju-fang; Qiu, Hai-bo; Yang, Yi; Liu, Song-qiao; Chen, Yong-ming; Li, Jia-qiong; Wu, Bin; Ding, Hui-min

2006-06-01

To compare the measurement of extra-vascular lung water (EVLW) by a single-indicator dilution technique and measurement obtained by gravimetry in different types of acute respiratory distress syndrome (ARDS). Thirty-three dogs were randomly assigned to three groups: control group, oleic acid group and hydrochloric acid group. ARDS was reproduced by either intravenous injection of oleic acid or intratracheal instillation of hydrochloric acid. EVLW was measured before ARDS, at the onset of ARDS and 10 hours after ARDS by a single indicator dilution technique. Ten hours after ARDS, dogs were sacrificed and then EVLW was quantitated by a gravimetric measurement (golden standard). Hemodynamics and pulmonary gas exchange were determined. There was a close positive correlation (r=0.8820, P<0.05) between single indicator dilution and gravimetric measurements. However, the measurement with the single indicator dilution was consistently higher than the gravimetric measurement. In the control group, there was a positive correlation (r=0.9870, P<0.05) between the values of EVLW as measured by single indicator dilution and by gravimetric measurements. In the oleic acid group, there was also a significant correlation (r=0.9360, P<0.05) between the values of EVLW as measured by single indicator dilution and by gravimetric measurements. In the hydrochloric acid group, correlation (r=0.7950, P<0.05) was also found between EVLW as measured by the two methods. However, the correlation found was lower in the hydrochloric acid group than those in other two groups. Hydrochloric acid instillation resulted in a significant increase in shunting and the partial pressure of carbon dioxide in artery (PaCO(2)) compared with oleic acid group at 10 hours after ARDS. The results of measuring EVLW using single indicator dilution measurement are closely related with those of gravimetric measurement in ARDS, however, the correlations varies with the methods of reproduction of ARDS.

Efficacy of disinfectants containing accelerated hydrogen peroxide against conidial arthrospores and isolated infective spores of Microsporum canis and Trichophyton sp.

PubMed

Moriello, Karen A; Hondzo, Hanna

2014-06-01

Accelerated hydrogen peroxide is a proprietary disinfectant formulation that is available for both commercial and home use and is labelled as antifungal. To determine the antifungal efficacy of accelerated hydrogen peroxide disinfectants against Microsporum and Trichophyton spp. Three products formulated as ready to use and three concentrates were used. Concentrates were tested at dilutions of 1:8, 1:16 (recommended dilution) and 1:32. One product was a surgical instrument disinfectant. Sterile water, sodium hypochlorite (1:32 dilution) and over-the-counter 3% hydrogen peroxide were used as controls. Conidial suspensions contained ~9.6 × 10(5) /mL Microsporum canis, ~1.0 × 10(7) /mL M. gypseum or ~2.0 × 10(7) /mL Trichophyton sp. and were tested at 1:10 dilution. Isolated infective spore suspensions of M. canis from an untreated cat and T. erinacei from an untreated hedgehog were tested at 1:10, 1:5 and 1:1 spore-to-disinfectant dilutions. Too many colonies to count were present on untreated control plates. Accelerated hydrogen peroxide and household hydrogen peroxide inhibited growth of both pathogens in conidial (1:10 dilution) and spore suspensions (1:10, 1:5 and 1:10 dilution). There was no lack of efficacy of products that were >12 months old. Accelerated hydrogen peroxide products are an option for environmental disinfection of surfaces exposed to M. canis and Trichophyton sp. after appropriate gross decontamination and mechanical cleaning with a detergent. The results from conidial testing were identical to those of isolated infected spore testing, which suggests that accelerated hydrogen peroxide products with label claim as antifungal against Trichophyton mentagrophytes may be suitable as an alternative disinfectant to sodium hypochlorite. © 2014 ESVD and ACVD.

Comparative in vitro efficacy of antimicrobial shampoos: a pilot study.

PubMed

Young, Rebecca; Buckley, Laura; McEwan, Neil; Nuttall, Tim

2012-02-01

This study compared the antimicrobial efficacy of shampoos against meticillin-sensitive Staphylococcus pseudintermedius (MSSP), meticillin-resistant S. pseudintermedius (MRSP), antibiotic-sensitive Pseudomonas aeruginosa (PA), multidrug-resistant P. aeruginosa (MDR-PA) and Malassezia pachydermatis. Three isolates were incubated for 10, 30 and 60 min with each shampoo diluted in phosphate-buffered saline. Aliquots were then incubated for 16-18 h on sheep blood agar (bacteria) or for 3 days on Sabouraud's dextrose agar (Malassezia). The minimal bactericidal concentrations (MBCs) for chlorhexidine products (Malaseb(®), Pyoderm(®)/Microbex(®) and Hibiscrub(®)) were 1:1,024-1:2,048 for MSSP and MRSP, 1:512-1:1,024 for PA and MDR-PA, and 1:2,048-1:5,096 for Malassezia at all time points. The MBCs for benzoyl peroxide (Paxcutol(®)) for MSSP and MRSP were 1:2-1:8 at 10 min, and 1:256 after 30 and 60 min. A 1:2 dilution was effective against Pseudomonas, and 1:512-1:1,024 dilutions were effective against Malassezia at all time points. The MBCs for ethyl lactate (Etiderm(®)) for MSSP and MRSP were 1:2 at 10 min, and 1:2-1:16 after 30 and 60 min. A 1:2 dilution was effective against Pseudomonas, and a 1:512 dilution was effective against Malassezia at all time points. Chloroxylenol (Coatex(®)) and acetic acid-boric acid (Malacetic(®)) were not effective against MSSP, MRSP or Pseudomonas. Both were effective against Malassezia at 1:8-1:16 dilution at 10 min, and at 1:8-1:32 dilution after 30 and 60 min. In conclusion, chlorhexidine appeared to be the most effective topical biocide, and MRSP and MDR-PA were no less susceptible than antibiotic-sensitive organisms. These results should, however, be confirmed with larger numbers of isolates. © 2011 The Authors. Veterinary Dermatology. © 2011 ESVD and ACVD.

40 CFR 1065.340 - Diluted exhaust flow (CVS) calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... action does not resolve a failure to meet the diluted exhaust flow verification (i.e., propane check) in... subsonic venturi flow meter, a long-radius ASME/NIST flow nozzle, a smooth approach orifice, a laminar flow...

Formation of nanocrystalline diamond in polymer like carbon films deposited by plasma CVD.

PubMed

Bhaduri, A; Chaudhuri, P

2009-09-01

Conventional plasma enhanced chemical vapour deposition (PECVD) method is generally not suitable for the growth of nanocrystalline diamond (NCD) films. However, our study shows that conditions favourable for powder formation help to grow large amount of nanocrystallites in conventional PECVD. With CH4 as the carbon source gas, dilution with Ar and moderate (50 W) rf power enhances formations of powders (nanoparticles) and C2 dimers within the plasma. On the other hand, with pure CH4 or with hydrogen diluted CH4, powder formation as also NCD growth is hindered. It is proposed that the nanoparticles formed in the plasma act as the "islands" while the C2 dimers are the "seeds" for the NCD growth. The structure of the films deposited on the grounded anode under different conditions of dilution has been studied. It is observed that with high Ar dilution the films contain NCD embedded in polymer like carbon (PLC) matrix.

Application of Cryocoolers to a Vintage Dilution Refrigerator

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

Schmitt, Richard; Smith, Gary; Ruschman, Mark

2011-06-06

A dilution refrigerator is required for 50mK detector operation of CDMS (Cryogenic Dark Matter Search). Besides shielding the dilution refrigerator itself, the liquid nitrogen shield and liquid helium bath in the refrigerator cool the detector cryostat heat shields and cool electronics, resulting in significant external heat loads at 80K and at 4K. An Oxford Instruments Kelvinox 400 has served this role for ten years but required daily transfers of liquid nitrogen and liquid helium. Complicating the cryogen supply is the location 800 meters below ground in an RF shielded, class 10000 clean room at Soudan, MN. Nitrogen and helium re-liquefiersmore » using cryocoolers were installed outside the clean room and continuously condense room temperature gas and return the liquids to the dilution refrigerator through a transfer line. This paper will describe the design, installation, controls and performance of liquefaction systems.« less

Navier-Stokes hydrodynamics of thermal collapse in a freely cooling granular gas.

PubMed

Kolvin, Itamar; Livne, Eli; Meerson, Baruch

2010-08-01

We show that, in dimension higher than one, heat diffusion and viscosity cannot arrest thermal collapse in a freely evolving dilute granular gas, even in the absence of gravity. Thermal collapse involves a finite-time blowup of the gas density. It was predicted earlier in ideal, Euler hydrodynamics of dilute granular gases in the absence of gravity, and in nonideal, Navier-Stokes granular hydrodynamics in the presence of gravity. We determine, analytically and numerically, the dynamic scaling laws that characterize the gas flow close to collapse. We also investigate bifurcations of a freely evolving dilute granular gas in circular and wedge-shaped containers. Our results imply that, in general, thermal collapse can only be arrested when the gas density becomes comparable with the close-packing density of grains. This provides a natural explanation to the formation of densely packed clusters of particles in a variety of initially dilute granular flows.

Impacts of blending on dilution of negatively buoyant brine discharge in a shallow tidal sea.

PubMed

Kämpf, Jochen

2009-07-01

A fine-resolution three-dimensional hydrodynamic model is applied to study the dilution of desalination brine discharged into a tidal sea. Based on given inflow rate and salinity excess of discharge brine, this study explores variations in mid-field dilutions when other low-salinity wastewater is added to the discharge. Findings reveal that this blending leads to a decrease in dilution in the mixing zone and therefore to higher levels of pollutants in this zone, while, on the other hand, the mixing zone occupies a smaller area. The reason is that the discharge of brine creates a density-driven flow that operates to partially remove effluent from the discharge location. This removal is less efficient for the decrease in density excess of the discharge. Hence, in an ambient sea of moderate mixing, blending can be expected to increase the risk of marine pollution in the mixing zone.

A method for measuring particle number emissions from vehicles driving on the road.

PubMed

Shi, J P; Harrison, R M; Evans, D E; Alam, A; Barnes, C; Carter, G

2002-01-01

Earlier research has demonstrated that the conditions of dilution of engine exhaust gases profoundly influence the size distribution and total number of particles emitted. Since real world dilution conditions are variable and therefore difficult to simulate, this research has sought to develop and validate a method for measuring particle number emissions from vehicles driving past on a road. This has been achieved successfully using carbon dioxide as a tracer of exhaust gas dilution. By subsequent adjustment of data to a constant dilution factor, it is possible to compare emissions from different vehicles using different technologies and fuels based upon real world emission data. Whilst further optimisation of the technique, especially in terms of matching the instrument response times is desirable, the measurements offer useful insights into emissions from gasoline and diesel vehicles, and the substantial proportion of particles emitted in the 3-7 nanometre size range.

Partial molar volume of n-alcohols at infinite dilution in water calculated by means of scaled particle theory.

PubMed

Graziano, Giuseppe

2006-04-07

The partial molar volume of n-alcohols at infinite dilution in water is smaller than the molar volume in the neat liquid phase. It is shown that the formula for the partial molar volume at infinite dilution obtained from the scaled particle theory equation of state for binary hard sphere mixtures is able to reproduce in a satisfactory manner the experimental data over a large temperature range. This finding implies that the packing effects play the fundamental role in determining the partial molar volume at infinite dilution in water also for solutes, such as n-alcohols, forming H bonds with water molecules. Since the packing effects in water are largely related to the small size of its molecules, the latter feature is the ultimate cause of the decrease in partial molar volume associated with the hydrophobic effect.

Competition explains limited attention and perceptual resources: implications for perceptual load and dilution theories.

PubMed

Scalf, Paige E; Torralbo, Ana; Tapia, Evelina; Beck, Diane M

2013-01-01

Both perceptual load theory and dilution theory purport to explain when and why task-irrelevant information, or so-called distractors are processed. Central to both explanations is the notion of limited resources, although the theories differ in the precise way in which those limitations affect distractor processing. We have recently proposed a neurally plausible explanation of limited resources in which neural competition among stimuli hinders their representation in the brain. This view of limited capacity can also explain distractor processing, whereby the competitive interactions and bias imposed to resolve the competition determine the extent to which a distractor is processed. This idea is compatible with aspects of both perceptual load and dilution models of distractor processing, but also serves to highlight their differences. Here we review the evidence in favor of a biased competition view of limited resources and relate these ideas to both classic perceptual load theory and dilution theory.

Refractometry for quality control of anesthetic drug mixtures.

PubMed

Stabenow, Jennifer M; Maske, Mindy L; Vogler, George A

2006-07-01

Injectable anesthetic drugs used in rodents are often mixed and further diluted to increase the convenience and accuracy of dosing. We evaluated clinical refractometry as a simple and rapid method of quality control and mixing error detection of rodent anesthetic or analgesic mixtures. Dilutions of ketamine, xylazine, acepromazine, and buprenorphine were prepared with reagent-grade water to produce at least 4 concentration levels. The refraction of each concentration then was measured with a clinical refractometer and plotted against the percentage of stock concentration. The resulting graphs were linear and could be used to determine the concentration of single-drug dilutions or to predict the refraction of drug mixtures. We conclude that refractometry can be used to assess the concentration of dilutions of single drugs and can verify the mixing accuracy of drug combinations when the components of the mixture are known and fall within the detection range of the instrument.

Deuterium dilution technique for body composition assessment: resolving methodological issues in children with moderate acute malnutrition.

PubMed

Fabiansen, Christian; Yaméogo, Charles W; Devi, Sarita; Friis, Henrik; Kurpad, Anura; Wells, Jonathan C

2017-08-01

Childhood malnutrition is highly prevalent and associated with high mortality risk. In observational and interventional studies among malnourished children, body composition is increasingly recognised as a key outcome. The deuterium dilution technique has generated high-quality data on body composition in studies of infants and young children in several settings, but its feasibility and accuracy in children suffering from moderate acute malnutrition requires further study. Prior to a large nutritional intervention trial among children with moderate acute malnutrition, we conducted pilot work to develop and adapt the deuterium dilution technique. We refined procedures for administration of isotope doses and collection of saliva. Furthermore, we established that equilibration time in local context is 3 h. These findings and the resulting standard operating procedures are important to improve data quality when using the deuterium dilution technique in malnutrition studies in field conditions, and may encourage a wider use of isotope techniques.

High-throughput method to predict extrusion pressure of ceramic pastes.

PubMed

Cao, Kevin; Liu, Yang; Tucker, Christopher; Baumann, Michael; Grit, Grote; Lakso, Steven

2014-04-14

A new method was developed to measure the rheology of extrudable ceramic pastes using a Hamilton MicroLab Star liquid handler. The Hamilton instrument, normally used for high throughput liquid processing, was expanded to function as a low pressure capillary rheometer. Diluted ceramic pastes were forced through the modified pipettes, which produced pressure drop data that was converted to standard rheology data. A known ceramic paste containing cellulose ether was made and diluted to various concentrations in water. The most dilute paste samples were tested in the Hamilton instrument and the more typical, highly concentrated, ceramic paste were tested with a hydraulic ram extruder fitted with a capillary die and pressure measurement system. The rheology data from this study indicates that the dilute high throughput method using the Hamilton instrument correlates to, and can predict, the rheology of concentrated ceramic pastes normally used in ceramic extrusion production processes.

Water-based adhesives with tailored hydrophobic association: dilution resistance and improved setting behavior.

PubMed

Dundua, Alexander; Landfester, Katharina; Taden, Andreas

2014-11-01

Hydrophobic association and stimuli-responsiveness is a powerful tool towards water-based adhesives with strongly improved properties, which is demonstrated based on the example of hydrophobically modified alkali-soluble latexes (HASE) with modulated association. Their rheological properties are highly tunable due to the hydrophobic domains that act as physical crosslinking sites of adjustable interaction strength. Ethanol, propanol, and butanol are used as water-soluble model additives with different hydrophobicity in order to specifically target the association sites and impact the viscoelastic properties and stimuli-responsiveness. The rheological and mechanical property response upon dilution with water can be tailored, and dilution-resistant or even dilution-thickening systems are obtained. The investigations are of high importance for water-based adhesives, as our findings provide insight into general structure-property relationships to improve their setting behavior, especially upon contact with wet substrates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Apparatuses and methods for deoxygenating biomass-derived pyrolysis oil

DOEpatents

Kalnes, Tom N.

2015-12-29

Apparatuses and methods for deoxygenating a biomass-derived pyrolysis oil are provided herein. In one example, the method comprises of dividing a feedstock stream into first and second feedstock portions. The feedstock stream comprises the biomass-derived pyrolysis oil and has a temperature of about 60.degree. C. or less. The first feedstock portion is combined with a heated organic liquid stream to form a first heated diluted pyoil feed stream. The first heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen to form an intermediate low-oxygen pyoil effluent. The second feedstock portion is combined with the intermediate low-oxygen pyoil effluent to form a second heated diluted pyoil feed stream. The second heated diluted pyoil feed stream is contacted with a second deoxygenating catalyst in the presence of hydrogen to form additional low-oxygen pyoil effluent.

Moderate Dilution of Copper Slag by Natural Gas

NASA Astrophysics Data System (ADS)

Zhang, Bao-jing; Zhang, Ting-an; Niu, Li-ping; Liu, Nan-song; Dou, Zhi-he; Li, Zhi-qiang

2018-01-01

To enable use of copper slag and extract the maximum value from the contained copper, an innovative method of reducing moderately diluted slag to smelt copper-containing antibacterial stainless steel is proposed. This work focused on moderate dilution of copper slag using natural gas. The thermodynamics of copper slag dilution and ternary phase diagrams of the slag system were calculated. The effects of blowing time, temperature, matte settling time, and calcium oxide addition were investigated. The optimum reaction conditions were identified to be blowing time of 20 min, reaction temperature of 1250°C, settling time of 60 min, CaO addition of 4% of mass of slag, natural gas flow rate of 80 mL/min, and outlet pressure of 0.1 MPa. Under these conditions, the Fe3O4 and copper contents of the residue were 7.36% and 0.50%, respectively.

Dispersion/dilution enhances phytoplankton blooms in low-nutrient waters

NASA Astrophysics Data System (ADS)

Lehahn, Yoav; Koren, Ilan; Sharoni, Shlomit; D'Ovidio, Francesco; Vardi, Assaf; Boss, Emmanuel

2017-03-01

Spatial characteristics of phytoplankton blooms often reflect the horizontal transport properties of the oceanic turbulent flow in which they are embedded. Classically, bloom response to horizontal stirring is regarded in terms of generation of patchiness following large-scale bloom initiation. Here, using satellite observations from the North Pacific Subtropical Gyre and a simple ecosystem model, we show that the opposite scenario of turbulence dispersing and diluting fine-scale (~1-100 km) nutrient-enriched water patches has the critical effect of regulating the dynamics of nutrients-phytoplankton-zooplankton ecosystems and enhancing accumulation of photosynthetic biomass in low-nutrient oceanic environments. A key factor in determining ecological and biogeochemical consequences of turbulent stirring is the horizontal dilution rate, which depends on the effective eddy diffusivity and surface area of the enriched patches. Implementation of the notion of horizontal dilution rate explains quantitatively plankton response to turbulence and improves our ability to represent ecological and biogeochemical processes in oligotrophic oceans.

High preservation of DNA standards diluted in 50% glycerol.

PubMed

Schaudien, Dirk; Baumgärtner, Wolfgang; Herden, Christiane

2007-09-01

Standard curves are important tools in real-time quantitative polymerase chain reaction (PCR) to precisely analyze gene expression patterns under physiologic and pathologic conditions. Handling of DNA standards often implies multiple cycles of freezing and thawing that might affect DNA stability and integrity. This in turn might influence the reliability and reproducibility of quantitative measurements in real-time PCR assays. In this study, 3 DNA standards such as murine tumor necrosis factor (TNF) alpha, interferon (IFN) gamma, and kainat-1 receptor were diluted in 50% glycerol or water after 1, 4, and 16 cycles of freezing and thawing and amplified copy numbers after real-time PCR were compared. The standards diluted in water showed a reduction to 83%, 55%, and 50% after 4 cycles, to 24%, 5%, and 4% after 16 cycles for kainat-1 receptor, TNFalpha, and IFNgamma standards, respectively, when compared with a single cycle of freezing and thawing. Interestingly, all cDNA samples diluted in 50% glycerol were amplified in comparable copy numbers even after 16 cycles of freezing and thawing. The effect of the standards undergoing different cycles of freezing and thawing on sample values was demonstrated by amplifying cDNA obtained from Borna disease virus infected and noninfected TNF-transgenic mice brain. This revealed significant differences of measured cDNA copy numbers using water-diluted DNA standards. In contrast, sample values did not vary using glycerol-diluted standards that were frozen and thawed for 16 times. In conclusion, glycerol storage of DNA standards represents a suitable tool for the accurate and reproducible quantification of cDNA samples in real-time PCR analysis.

Controlled biomass formation and kinetics of toluene degradation in a bioscrubber and in a reactor with a periodically moved trickle-bed.

PubMed

Wübker, S M; Laurenzis, A; Werner, U; Friedrich, C

1997-08-20

The kinetics of degradation of toluene from a model waste gas and of biomass formation were examined in a bioscrubber operated under different nutrient limitations with a mixed culture. The applicability of the kinetics of continuous cultivation of the mixed culture was examined for a special trickle-bed reactor with a periodically moved filter bed. The efficiency of toluene elimination of the bioscrubber was 50 to 57% and depended on the toluene mass transfer as evident from a constant productivity of 0.026 g dry cell weight/L . h over the dilution rate. Under potassium limitation the biomass productivity was reduced by 60% to 0.011 g dry cell weight/L . h at a dilution rate of 0.013/h. Conversely, at low dilution rates the specific toluene degradation rates increased. Excess biomass in a trickle-bed reactor causes reduction of interfacial area and mass transfer, and increase in pressure drop. To avoid these disadvantages, the trickle-bed was moved periodically and biomass was removed with outflowing medium. The concentration of steady state biomass fixed on polyamide beads decreased hyperbolically with the dilution rate. Also, the efficiency of toluene degradation decreased from 72 to 56% with increasing dilution rate while the productivity increased. Potassium limitation generally caused a reduction in biomass, productivity, and yield while the specific degradation increased with dilution rate. This allowed the application of the principles of the chemostat to the trickle-bed reactor described here, for toluene degradation from waste gases. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 686-692, 1997.

Mitochondrial DNA as a non-invasive biomarker: Accurate quantification using real time quantitative PCR without co-amplification of pseudogenes and dilution bias

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

Malik, Afshan N., E-mail: afshan.malik@kcl.ac.uk; Shahni, Rojeen; Rodriguez-de-Ledesma, Ana

2011-08-19

Highlights: {yields} Mitochondrial dysfunction is central to many diseases of oxidative stress. {yields} 95% of the mitochondrial genome is duplicated in the nuclear genome. {yields} Dilution of untreated genomic DNA leads to dilution bias. {yields} Unique primers and template pretreatment are needed to accurately measure mitochondrial DNA content. -- Abstract: Circulating mitochondrial DNA (MtDNA) is a potential non-invasive biomarker of cellular mitochondrial dysfunction, the latter known to be central to a wide range of human diseases. Changes in MtDNA are usually determined by quantification of MtDNA relative to nuclear DNA (Mt/N) using real time quantitative PCR. We propose that themore » methodology for measuring Mt/N needs to be improved and we have identified that current methods have at least one of the following three problems: (1) As much of the mitochondrial genome is duplicated in the nuclear genome, many commonly used MtDNA primers co-amplify homologous pseudogenes found in the nuclear genome; (2) use of regions from genes such as {beta}-actin and 18S rRNA which are repetitive and/or highly variable for qPCR of the nuclear genome leads to errors; and (3) the size difference of mitochondrial and nuclear genomes cause a 'dilution bias' when template DNA is diluted. We describe a PCR-based method using unique regions in the human mitochondrial genome not duplicated in the nuclear genome; unique single copy region in the nuclear genome and template treatment to remove dilution bias, to accurately quantify MtDNA from human samples.« less

Gas nanobubbles and aqueous nanostructures: the crucial role of dynamization.

PubMed

Demangeat, Jean-Louis

2015-04-01

Nanobubbles (NBs) have been a subject of intensive research over the past decade. Their peculiar characteristics, including extremely low buoyancy, longevity, enhanced solubility of oxygen in water, zeta potentials and burst during collapse, have led to many applications in the industrial, biological and medical fields. NBs may form spontaneously from dissolved gas but the process is greatly enhanced by gas supersaturation and mechanical actions such as dynamization. Therefore, the formation of NBs during the preparation of homeopathic dilutions under atmospheric pressure cannot be ignored. I suggested in 2009 the involvement of NBs in nanometric superstructures revealed in high dilutions using NMR relaxation. These superstructures seemed to increase in size with dilution, well into the ultramolecular range (>12c). I report here new experiments that confirm the involvement of NBs and prove the crucial role of dynamization to create superstructures specific to the solute. A second dynamization was shown to enhance or regenerate these superstructures. I postulate that superstructures result from a nucleation process of NBs around the solute, with shells of highly organized water (with ions and silicates if any) which protect the solute against out-diffusion and behave as nucleation centres for further dilution steps. The sampling tip may play an active role by catching the superstructures and thus carry the encaged solute across the dilution range, possibly up to the ultramolecular range. The superstructures were not observed at low dilution, probably because of a destructuring of the solvent by the solute and/or of an inadequate gas/solute ratio. Copyright © 2015 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Effects of holding temperature and storage time on respiratory rate, motility, and fertility of chicken and turkey semen.

PubMed

Clarke, R N; Sexton, T J; Ottinger, M A

1982-09-01

A series of experiments was conducted to measure the respiratory activity, motility, and fertility of chicken and turkey sperm in undiluted and diluted (1 part semen to 5 parts Beltsville Poultry Semen Extender) semen held at either 41, 25, 15, or 5 C for 3 or 6 hr. Sperm respiration was temperature dependent, increasing with increasing temperature. When incubated under identical conditions, the respiratory rate of spermatozoa in diluted semen of both species was significantly (P less than .05) higher than in undiluted semen. In undiluted and diluted chicken and turkey semen, sperm mortality was lowest at 41 C. No differences in the motility of spermatozoa from undiluted and diluted semen of either species were observed in the unstored controls. Sperm motility in samples held at 15 or 5 C was similar to that of the unstored controls. The fertility of diluted chicken semen was highest (75%) after 6 hr of storage at 5 C. Fertility levels (71 to 83%) of chicken semen was highest (75%) after 6 hr of storage at 5 C. Fertility levels (71 to 83%) of chicken semen held for 3 hr at 25, 15, or 5 C did not differ from the unstored control. In contrast, the fertilizing capacity of diluted turkey semen (0 to 45%) was significantly lower than the unstored controls (68%), regardless of holding times and temperatures. The fertility of undiluted turkey semen was significantly (P less than .05) lower than the unstored control in all cases, with the exception of semen held at 25 C for 3 hr.

Relative sensitivity of an amphipod Hyalella azteca, a midge Chironomus dilutus, and a unionid mussel Lampsilis siliquoidea to a toxic sediment

USGS Publications Warehouse

Ingersoll, Christopher G.; Kunz, James L.; Hughes, Jamie P.; Wang, Ning; Ireland, D. Scott; Mount, David R.; Hockett, J. Russell; Valenti, Ted W

2015-01-01

The objective of the present study was to evaluate the relative sensitivity of test organisms in exposures to dilutions of a highly toxic sediment contaminated with metals and organic compounds. One dilution series was prepared using control sand (low total organic carbon [TOC; <0.1%, low binding capacity for contaminants]) and a second dilution series was prepared using control sediment from West Bearskin Lake, Minnesota, USA (high TOC [∼10% TOC, higher binding capacity for contaminants]). Test organisms included an amphipod (Hyalella azteca; 10-d and 28-d exposures), a midge (Chironomus dilutus; 20-d and 48-d exposures started with <1-h-old larvae, and 13-d and 48-d exposures started with 7-d-old larvae), and a unionid mussel (Lampsilis siliquoidea; 28-d exposures). Relative species sensitivity depended on the toxicity endpoint and the diluent. All 3 species were more sensitive in sand dilutions than in West Bearskin Lake sediment dilutions. The <1-h-old C. dilutus were more sensitive than 7-d-old C. dilutus, but replicate variability was high in exposures started with the younger midge larvae. Larval biomass and adult emergence endpoints of C. dilutus exhibited a similar sensitivity. Survival, weight, and biomass of H. azteca were more sensitive endpoints in 28-d exposures than in 10-d exposures. Weight and biomass of L. siliquoidea were sensitive endpoints in both sand and West Bearskin Lake sediment dilutions. Metals, ammonia, oil, and other organic contaminants may have contributed to the observed toxicity.

[Evaluation of visualization of biological stains with the use of alternative light source (ALS) for the purpose of genetic identification. Part I. Blood and saliva stains analysis].

PubMed

Szeremeta, Michał; Pepiński, Witold; Niemcunowicz-Janica, Anna; Skawrońska, Małgorzata; Sackiewicz, Adam; Ptaszyńska-Sarosiek, Iwona; Okłota, Magdalena

2010-01-01

The objective of the investigation was evaluation of visualization of human blood and saliva stains with the use of alternative light source for the purpose of genetic identification. Experimental bloodstains on the bright base were the most clearly seen in the natural light and white light, up to blood dilution of 1:600. Complete typeability of AmpFISTR SGM Plus kit profiles was obtained from bloodstains at dilution 1:1500. Partial AmpFISTR SGM Plus kit profiles were typed from bloodstains at dilutions 1:1750 and 1:2000. Experimental saliva stains on the light-colored base were completely invisible in the natural light and white light, while they were visualized at wavelength range 300-415 nm through yellow goggles, and at wavelength range 300-455 nm through orange goggles at saliva dilution 1: 600. Complete typeability of AmpFISTR SGM Plus kit loci was obtained from saliva stains at dilution 1:1750. Partial AmpFISTR SGM Plus kit profiles were typed from saliva stains at dilution 1:2000. The wavelength of 455 nm and orange goggles were the optimal set for visualization of bloodstains on various, noncontrasting materials. Other useful wavelength/combinations of goggles were CSS light/red goggles. In case of saliva, the most useful general condition for visualization of stains on various, non-contrasting materials was with the wavelength set to 300-415 nm, while wearing yellow goggles. Other useful combinations of wavelength/goggles were 300-455 nm/orange or red goggles, and also CSS light/orange or red goggles.

Pretreatment efficiency and structural characterization of rice straw by an integrated process of dilute-acid and steam explosion for bioethanol production.

PubMed

Chen, Wen-Hua; Pen, Ben-Li; Yu, Ching-Tsung; Hwang, Wen-Song

2011-02-01

The combined pretreatment of rice straw using dilute-acid and steam explosion followed by enzymatic hydrolysis was investigated and compared with acid-catalyzed steam explosion pretreatment. In addition to measuring the chemical composition, including glucan, xylan and lignin content, changes in rice straw features after pretreatment were investigated in terms of the straw's physical properties. These properties included crystallinity, surface area, mean particle size and scanning electron microscopy imagery. The effect of acid concentration on the acid-catalyzed steam explosion was studied in a range between 1% and 15% acid at 180°C for 2 min. We also investigated the influence of the residence time of the steam explosion in the combined pretreatment and the optimum conditions for the dilute-acid hydrolysis step in order to develop an integrated process for the dilute-acid and steam explosion. The optimum operational conditions for the first dilute-acid hydrolysis step were determined to be 165°C for 2 min with 2% H(2)SO(4) and for the second steam explosion step was to be carried out at 180°C for 20 min; this gave the most favorable combination in terms of an integrated process. We found that rice straw pretreated by the dilute-acid/steam explosions had a higher xylose yield, a lower level of inhibitor in the hydrolysate and a greater degree of enzymatic hydrolysis; this resulted in a 1.5-fold increase in the overall sugar yield when compared to the acid-catalyzed steam explosion. Copyright © 2010 Elsevier Ltd. All rights reserved.

Dilute-and-shoot coupled to nanoflow liquid chromatography high resolution mass spectrometry for the determination of drugs of abuse and sport drugs in human urine.

PubMed

Alcántara-Durán, Jaime; Moreno-González, David; Beneito-Cambra, Miriam; García-Reyes, Juan F

2018-05-15

In this work, a sensitive nanoflow liquid chromatography high-resolution mass spectrometry screening method has been developed for the determination of multiclass drugs of abuse and sport drugs in human urine. 81 drugs belonging to different multiclass pharmaceuticals were targeted. The method is based on the use of a nanoLC column (75 µm × 150 mm, 3 µm particle size and 100 Å pore) with the nanospray emitter tip integrated so that dead volumes are significantly minimized. Data acquisition method included both full-scan and all ion fragmentation experiments using an Orbitrap analyser (Q-Exactive) operated in the positive ionization mode. To increase laboratory throughput, a dilute-and-shoot methodology has been tested and proposed, based solely on direct urine dilution without further sample workup. Matrix effects were evaluated, showing a negligible effect for all studied compounds when a dilution 1:50 was implemented. Despite this high-dilution factor, limits of quantification were still satisfactory, with values below 5 µg L -1 in most cases, being lower than their minimum required performance limits correspond established by the World Anti-Doping Agency. Therefore, the use of the dilute-and-shoot method with the enhanced sensitivity provided by nanoflow LC setup could be useful tool for the determination of studied compounds in drug testing, thus increasing laboratory performance, because a minimum sample treatment steps are required. Copyright © 2018 Elsevier B.V. All rights reserved.

Poor preservation efficacy versus quality and safety of pediatric extemporaneous liquids.

PubMed

Ghulam, Asif; Keen, Kate; Tuleu, Catherine; Wong, Ian Chi-Kei; Long, Paul F

2007-05-01

Most medicines are available only as solid, adult-strength dosage forms from which oral extemporaneous liquids are often prepared for children. There are few comprehensive reference lists for the preparation of pediatric extemporaneous formulations. Some pediatric reformulations are made by diluting the suspending vehicle, and a shelf life of up to 3 months can be used without documented microbial stability. Although most commercially available ready-to-use vehicles are supplied as preserved formulations, it is still common practice in many European dispensaries to prepare and dilute these vehicles as required for specific prescriptions. To determine what influence dilution of vehicles has on the preservation efficiency of extemporaneous formulations. Suspending vehicles were made by diluting methylcellulose 1% and simple syrup, BP (British Pharmacopoeia) in ratios of 1:1 and 1:4. The efficacy of antimicrobial preservation was tested according to the 2007 standards required by the BP. Dilution in ratios greater than 1:1 failed the BP 2007 criteria. Such dilution represents a potential biohazard, especially to premature, newborn, or immunocompromised children, exposing them not only to possible organoleptic changes of the preparation, but also to ingestion of either dangerous numbers of microorganisms or medicines that may have undergone biotransformation, rendering them inactive or toxic. Significant concerns have been raised regarding the quality of extemporaneous preparations. We call for further research in this neglected area to address issues of antimicrobial preservation, including revision of existing quality assurance monographs. Moreover, these monographs should take into account testing that simulates multiple dosing from a single storage container during the intended in-use shelf life of multidose extemporaneous preparations.

Sodium perxenate permits rapid oxidation of manganese for easy spectrophotometric determination

NASA Technical Reports Server (NTRS)

Bane, R. W.

1967-01-01

Sodium perxenate oxidizes manganese to permanganate almost instantaneously in dilute acid solution and without a catalyst. A solution is prepared by dissolving 200 mg of sodium perxenate in distilled water and diluting to 100 ml.

Comparison of the in vitro effects of saline, hypertonic hydroxyethyl starch, hypertonic saline, and two forms of hydroxyethyl starch on whole blood coagulation and platelet function in dogs.

PubMed

Wurlod, Virginie A; Howard, Judith; Francey, Thierry; Schweighauser, Ariane; Adamik, Katja N

2015-01-01

To compare the in vitro effects of hypertonic solutions and colloids to saline on coagulation in dogs. In vitro experimental study. Veterinary teaching hospital. Twenty-one adult dogs. Blood samples were diluted with saline, 7.2% hypertonic saline solution with 6% hydroxyethylstarch with an average molecular weight of 200 kDa and a molar substitution of 0.4 (HH), 7.2% hypertonic saline (HTS), hydroxyethyl starch (HES) 130/0.4 or hydroxyethyl starch 600/0.75 at ratios of 1:22 and 1:9, and with saline and HES at a ratio of 1:3. Whole blood coagulation was analyzed using rotational thromboelastometry (extrinsic thromboelastometry-cloting time (ExTEM-CT), maximal clot firmness (MCF) and clot formation time (CFT) and fibrinogen function TEM-CT (FibTEM-CT) and MCF) and platelet function was analyzed using a platelet function analyzer (closure time, CTPFA ). All parameters measured were impaired by saline dilution. The CTPFA was prolonged by 7.2% hypertonic saline solution with 6% hydroxyethylstarch with an average molecular weight of 200 kDa and a molar substitution of 0.4 (HH) and HTS but not by HES solutions. At clinical dilutions equivalent to those generally administered for shock (saline 1:3, HES 1:9, and hypertonic solutions 1:22), CTPFA was more prolonged by HH and HTS than other solutions but more by saline than HES. No difference was found between the HES solutions or the hypertonic solutions. ExTEM-CFT and MCF were impaired by HH and HTS but only mildly by HES solutions. At clinically relevant dilutions, no difference was found in ExTEM-CFT between HTS and saline or in ExTEM-MCF between HH and saline. No consistent difference was found between the 2 HES solutions but HH impaired ExTEM-CFT and MCF more than HTS. At high dilutions, FibTEM-CT and -MCF and ExTEM-CT were impaired by HES. Hypertonic solutions affect platelet function and whole blood coagulation to a greater extent than saline and HES. At clinically relevant dilutions, only CTPFA was markedly more affected by hypertonic solutions than by saline. At high dilutions, HES significantly affects coagulation but to no greater extent than saline at clinically relevant dilutions. © Veterinary Emergency and Critical Care Society 2015.

Representative Atmospheric Plume Development for Elevated Releases

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

Eslinger, Paul W.; Lowrey, Justin D.; McIntyre, Justin I.

2014-02-01

An atmospheric explosion of a low-yield nuclear device will produce a large number of radioactive isotopes, some of which can be measured with airborne detection systems. However, properly equipped aircraft may not arrive in the region where an explosion occurred for a number of hours after the event. Atmospheric conditions will have caused the radioactive plume to move and diffuse before the aircraft arrives. The science behind predicting atmospheric plume movement has advanced enough that the location of the maximum concentrations in the plume can be determined reasonably accurately in real time, or near real time. Given the assumption thatmore » an aircraft can follow a plume, this study addresses the amount of atmospheric dilution expected to occur in a representative plume as a function of time past the release event. The approach models atmospheric transport of hypothetical releases from a single location for every day in a year using the publically available HYSPLIT code. The effective dilution factors for the point of maximum concentration in an elevated plume based on a release of a non-decaying, non-depositing tracer can vary by orders of magnitude depending on the day of the release, even for the same number of hours after the release event. However, the median of the dilution factors based on releases for 365 consecutive days at one site follows a power law relationship in time, as shown in Figure S-1. The relationship is good enough to provide a general rule of thumb for estimating typical future dilution factors in a plume starting at the same point. However, the coefficients of the power law function may vary for different release point locations. Radioactive decay causes the effective dilution factors to decrease more quickly with the time past the release event than the dilution factors based on a non-decaying tracer. An analytical expression for the dilution factors of isotopes with different half-lives can be developed given the power law expression for the non-decaying tracer. If the power-law equation for the median dilution factor, Df, based on a non-decaying tracer has the general form Df=a(×t)^(-b) for time t after the release event, then the equation has the form Df=e^(-λt)×a×t^(-b) for a radioactive isotope, where λ is the decay constant for the isotope.« less

Diluted magnetic semiconductor nanowires exhibiting magnetoresistance

DOEpatents

Yang, Peidong [El Cerrito, CA; Choi, Heonjin [Seoul, KR; Lee, Sangkwon [Daejeon, KR; He, Rongrui [Albany, CA; Zhang, Yanfeng [El Cerrito, CA; Kuykendal, Tevye [Berkeley, CA; Pauzauskie, Peter [Berkeley, CA

2011-08-23

A method for is disclosed for fabricating diluted magnetic semiconductor (DMS) nanowires by providing a catalyst-coated substrate and subjecting at least a portion of the substrate to a semiconductor, and dopant via chloride-based vapor transport to synthesize the nanowires. Using this novel chloride-based chemical vapor transport process, single crystalline diluted magnetic semiconductor nanowires Ga.sub.1-xMn.sub.xN (x=0.07) were synthesized. The nanowires, which have diameters of .about.10 nm to 100 nm and lengths of up to tens of micrometers, show ferromagnetism with Curie temperature above room temperature, and magnetoresistance up to 250 Kelvin.

Extended Le Chatelier's formula for carbon dioxide dilution effect on flammability limits.

PubMed

Kondo, Shigeo; Takizawa, Kenji; Takahashi, Akifumi; Tokuhashi, Kazuaki

2006-11-02

Carbon dioxide dilution effect on the flammability limits was measured for various flammable gases. The obtained values were analyzed using the extended Le Chatelier's formula developed in a previous study. As a result, it has been found that the flammability limits of methane, propane, propylene, methyl formate, and 1,1-difluoroethane are adequately explained by the extended Le Chatelier's formula using a common set of parameter values. Ethylene, dimethyl ether, and ammonia behave differently from these compounds. The present result is very consistent with what was obtained in the case of nitrogen dilution.

Seasonal Variation of the Effect of Extremely Diluted Agitated Gibberellic Acid (10e-30) on Wheat Stalk Growth: A Multiresearcher Study

PubMed Central

Endler, Peter Christian; Matzer, Wolfgang; Reich, Christian; Reischl, Thomas; Hartmann, Anna Maria; Thieves, Karin; Pfleger, Andrea; Hofäcker, Jürgen; Lothaller, Harald; Scherer-Pongratz, Waltraud

2011-01-01

The influence of a homeopathic high dilution of gibberellic acid on wheat growth was studied at different seasons of the year. Seedlings were allowed to develop under standardized conditions for 7 days; plants were harvested and stalk lengths were measured. The data obtained confirm previous findings, that ultrahigh diluted potentized gibberellic acid affects stalk growth. Furthermore, the outcome of the study suggests that experiments utilizing the bioassay presented should best be performed in autumn season. In winter and spring, respectively, no reliable effects were found. PMID:22125426

Precooling of a dilution refrigerator

NASA Astrophysics Data System (ADS)

Pavlov, Valentin N.

A non-trivial system for Precooling of the dilution refrigerator for low-temperatureexperiments on an ISOL-facility is described in detail. Neither exchange gas in the vacuum jacket of the cryostat nor a demantable window in the 4K shield are used in this system. Instead of that the dilution refrigerator is supplemented with two capillaries and a heater in order to cool all low-temperature parts of the refrigerator down to start conditions. The, time of cooling depends on the total impedance of the first heat exchanger. Such system has been developed and tested in Dubna, and it is in operation.

Computer registration of radioactive indicator-dilution curves.

PubMed

Shepherd, A P; Perry, M A; Alexander, G M; Granger, D N; Riedel, G L; Kvietys, P R; Franke, C P

1983-12-01

A system is described for recording indicator-dilution curves produced by gamma radiation-emitting tracers. The system consists of a flow-through cuvette in a well counter, appropriate commercially available gamma radiation-detecting equipment, an Apple II computer, and a two-channel pulse-counting interface of our own design. With the counting interface and the software described here, an investigator can simultaneously record two indicator-dilution curves produced by gamma emitters. Instead of having to wait hours or days for results, the investigator can watch the data being recorded and display the results in graphic form almost immediately after each injection.

Methods for deoxygenating biomass-derived pyrolysis oil

DOEpatents

Baird, Lance Awender; Brandvold, Timothy A.

2015-06-30

Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method for deoxygenating a biomass-derived pyrolysis oil comprising the steps of combining a biomass-derived pyrolysis oil stream with a heated low-oxygen-pyoil diluent recycle stream to form a heated diluted pyoil feed stream is provided. The heated diluted pyoil feed stream has a feed temperature of about 150.degree. C. or greater. The heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen at first hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

Automatic dilution gaging of rapidly varying flow

USGS Publications Warehouse

Duerk, M.D.

1983-01-01

The analysis showed that the discharges measured by dye-dilution techniques were generally within ± 10 percent of the discharges determined from ratings established by current-meter measurements. Larger differences were noted at the start of and on the rising limb of four hydrographs. Of the 20 storms monitored, dilution measurements on 17 were of acceptable accuracy. Peak discharges from the open-channel site ranged from 0 to 12 percent departures from the existing rating whereas the comparison of peak discharge at the storm sewer site ranged from 0 to 5 percent departures from the existing rating.

Nuclei-mode particulate emissions and their response to fuel sulfur content and primary dilution during transient operations of old and modern diesel engines.

PubMed

Liu, Z Gerald; Vasys, Victoria N; Kittelson, David B

2007-09-15

The effects of fuel sulfur content and primary dilution on PM number emissions were investigated during transient operations of an old and a modern diesel engine. Emissions were also studied during steady-state operations in order to confirm consistency with previous findings. Testing methods were concurrent with those implemented by the EPA to regulate PM mass emissions, including the use of the Federal Transient Testing Procedure-Heavy Duty cycle to simulate transient conditions and the use of a Critical Flow Venturi-Constant Volume System to provide primary dilution. Steady-state results were found to be consistent with previous studies in that nuclei-mode particulate emissions were largely reduced when lower-sulfur content fuel was used in the newer engine, while the nuclei-mode PM emissions from the older engine were much less affected by fuel sulfur content. The transient results, however, show that the total number of nuclei-mode PM emissions from both engines increases with fuel sulfur content, although this effect is only seen under the higher primary dilution ratios with the older engine. Transient results further show that higher primary dilution ratios increase total nuclei-mode PM number emissions in both engines.

Analysis of boron dilution in a four-loop PWR

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

Sun, J.G.; Sha, W.T.

1995-03-01

Thermal mixing and boron dilution in a pressurized water reactor were analyzed with COMMIX codes. The reactor system was the four-loop Zion reactor. Two boron dilution scenarios were analyzed. In the first scenario, the plant is in cold shutdown and the reactor coolant system has just been filled after maintenance on the steam generators. To flush the air out of the steam generator tubes, a reactor coolant pump (RCP) is started, with the water in the pump suction line devoid of boron and at the same temperature as the coolant in the system. In the second scenario, the plant ismore » at hot standby and the reactor coolant system has been heated to operating temperature after a long outage. It is assumed that an RCP is started, with the pump suction line filled with cold unborated water, forcing a slug of diluted coolant down the downcomer and subsequently through the reactor core. The subsequent transient thermal mixing and boron dilution that would occur in the reactor system is simulated for these two scenarios. The reactivity insertion rate and the total reactivity are evaluated and a sensitivity study is performed to assess the accuracy of the numerical modeling of the geometry of the reactor coolant system.« less

Improving the Efficiency of 3-D Hydrogeological Mixers: Dilution Enhancement Via Coupled Engineering-Induced Transient Flows and Spatial Heterogeneity

NASA Astrophysics Data System (ADS)

Di Dato, Mariaines; de Barros, Felipe P. J.; Fiori, Aldo; Bellin, Alberto

2018-03-01

Natural attenuation and in situ oxidation are commonly considered as low-cost alternatives to ex situ remediation. The efficiency of such remediation techniques is hindered by difficulties in obtaining good dilution and mixing of the contaminant, in particular if the plume deformation is physically constrained by an array of wells, which serves as a containment system. In that case, dilution may be enhanced by inducing an engineered sequence of injections and extractions from such pumping system, which also works as a hydraulic barrier. This way, the aquifer acts as a natural mixer, in a manner similar to the industrialized engineered mixers. Improving the efficiency of hydrogeological mixers is a challenging task, owing to the need to use a 3-D setup while relieving the computational burden. Analytical solutions, though approximated, are a suitable and efficient tool to seek the optimum solution among all possible flow configurations. Here we develop a novel physically based model to demonstrate how the combined spatiotemporal fluctuations of the water fluxes control solute trajectories and residence time distributions and therefore, the effectiveness of contaminant plume dilution and mixing. Our results show how external forcing configurations are capable of inducing distinct time-varying groundwater flow patterns which will yield different solute dilution rates.

Antibacterial activity of dilute povidone-iodine solutions used for ocular surface disinfection in dogs.

PubMed

Roberts, S M; Severin, G A; Lavach, J D

1986-06-01

Bacterial cultures of specimens from healthy canine eyelids and ocular surfaces were found to demonstrate bacterial growth in 69.7% (53/76) of the eyes sampled. Organisms most commonly isolated included: Staphylococcus aureus, alpha-hemolytic Streptococcus sp, S epidermidis, and Escherichia coli. Evaluation of dilute povidone-iodine solutions for effectiveness as ocular surface disinfectants was conducted. Bacterial growth initially detected in 32 of 46 eyes was not detected after disinfection with a 2-minute scrub and 2-minute soaking procedure, using 1:2, 1:10, or 1:50 dilutions of a povidone-iodine solution that contained 1% available iodine. The eyelid and ocular surfaces of 16 eyes were disinfected with 1:100 povidone-iodine solution. Bacterial growth initially present in 10 of 16 eyes was present in 1 eye after disinfection and consisted of a single colony of E coli. After eyes were disinfected with 1:10, 1:50, or 1:100 povidone-iodine solutions, there was no evidence of corneal epithelial edema or sloughing. In 15 eyes subjected to disinfection with the 1:2 dilution, one instance of epithelial corneal edema was noticed. A 1:50 dilution of povidone-iodine is recommended as an ocular surface disinfectant for use in presurgical situations.

Sterility and Stability of Diluted Carprofen in a Multidose Vial in the Laboratory Animal Setting.

PubMed

Simonek, Gregory D; Alarcio, Gwendolyne G; Brignolo, Laurie L

2017-05-01

Using compounded multidose vials (cMDV) is a common practice in the laboratory animal setting, where medications often are diluted to provide appropriate doses to rodents. However, bacterial contamination of MDV has been well established in both the human and veterinary medical literature. For this study, we created 14 cMDV by diluting carprofen into sterile water (dilution, 1:10) and stored 6 cMDV each at 5 and 24 °C. The stoppers of the cMDV were not cleaned with alcohol, and all were punctured twice daily for 28 d. The sterility of the diluted carprofen was evaluated by assessing bacterial growth on days 0, 7, 14, 21, and 28 and by testing for bacterial endotoxin on days 0 and 28. We used liquid chromatography-tandem mass spectrometry to assess the stability of 2 cMDV, with each cMDV being divided into the 2 storage-temperature subsets for days 0, 7, 14, 21, and 28. Neither bacterial contamination nor endotoxin was detected, and drug stability was stable over the 28 d. We suggest that with pragmatic techniques, such as secondary containment and consistent use of new needles, the contents of cMDV can remain sterile and stable for 28 d.

Declining ecosystem health and the dilution effect

PubMed Central

Khalil, Hussein; Ecke, Frauke; Evander, Magnus; Magnusson, Magnus; Hörnfeldt, Birger

2016-01-01

The “dilution effect” implies that where species vary in susceptibility to infection by a pathogen, higher diversity often leads to lower infection prevalence in hosts. For directly transmitted pathogens, non-host species may “dilute” infection directly (1) and indirectly (2). Competitors and predators may (1) alter host behavior to reduce pathogen transmission or (2) reduce host density. In a well-studied system, we tested the dilution of the zoonotic Puumala hantavirus (PUUV) in bank voles (Myodes glareolus) by two competitors and a predator. Our study was based on long-term PUUV infection data (2003–2013) in northern Sweden. The field vole (Microtus agrestis) and the common shrew (Sorex araneus) are bank vole competitors and Tengmalm’s owl (Aegolius funereus) is a main predator of bank voles. Infection probability in bank voles decreased when common shrew density increased, suggesting that common shrews reduced PUUV transmission. Field voles suppressed bank vole density in meadows and clear-cuts and indirectly diluted PUUV infection. Further, Tengmalm’s owl decline in 1980–2013 may have contributed to higher PUUV infection rates in bank voles in 2003–2013 compared to 1979–1986. Our study provides further evidence for dilution effect and suggests that owls may have an important role in reducing disease risk. PMID:27499001

Sterility and Stability of Diluted Carprofen in a Multidose Vial in the Laboratory Animal Setting

PubMed Central

Simonek, Gregory D; Alarcio, Gwendolyne G; Brignolo, Laurie L

2017-01-01

Using compounded multidose vials (cMDV) is a common practice in the laboratory animal setting, where medications often are diluted to provide appropriate doses to rodents. However, bacterial contamination of MDV has been well established in both the human and veterinary medical literature. For this study, we created 14 cMDV by diluting carprofen into sterile water (dilution, 1:10) and stored 6 cMDV each at 5 and 24 °C. The stoppers of the cMDV were not cleaned with alcohol, and all were punctured twice daily for 28 d. The sterility of the diluted carprofen was evaluated by assessing bacterial growth on days 0, 7, 14, 21, and 28 and by testing for bacterial endotoxin on days 0 and 28. We used liquid chromatography–tandem mass spectrometry to assess the stability of 2 cMDV, with each cMDV being divided into the 2 storage-temperature subsets for days 0, 7, 14, 21, and 28. Neither bacterial contamination nor endotoxin was detected, and drug stability was stable over the 28 d. We suggest that with pragmatic techniques, such as secondary containment and consistent use of new needles, the contents of cMDV can remain sterile and stable for 28 d. PMID:28535864

Nucleation mode particles with a nonvolatile core in the exhaust of a heavy duty diesel vehicle.

PubMed

Rönkkö, Topi; Virtanen, Annele; Kannosto, Jonna; Keskinen, Jorma; Lappi, Maija; Pirjola, Liisa

2007-09-15

The characteristics of the nucleation mode particles of a Euro IV heavy-duty diesel vehicle exhaust were studied. The NOx and PM emissions of the vehicle were controlled through the use of cooled EGR and high-pressure fuel injection techniques; no exhaust gas after-treatment was used. Particle measurements were performed in vehicle laboratory and on road. Nucleation mode dominated the particle number size distribution in all the tested driving conditions. According to the on-road measurements, the nucleation mode was already formed after 0.7 s residence time in the atmosphere and no significant changes were observed for longer residence times. The nucleation mode was insensitive to the fuel sulfur content, dilution air temperature, and relative humidity. An increase in the dilution ratio decreased the size of the nucleation mode particles. This behavior was observed to be linked to the total hydrocarbon concentration in the diluted sample. In volatility measurements, the nucleation mode particles were observed to have a nonvolatile core with volatile species condensed on it. The results indicate that the nucleation mode particles have a nonvolatile core formed before the dilution process. The core particles have grown because of the condensation of semivolatile material, mainly hydrocarbons, during the dilution.

Application of isotope dilution technique in vitamin A nutrition.

PubMed

Wasantwisut, Emorn

2002-09-01

The isotope dilution technique involving deuterated retinol has been developed to quantitatively estimate total body reserves of vitamin A in humans. The technique provided good estimates in comparison to hepatic vitamin A concentrations in Bangladeshi surgical patients. Kinetic studies in the United States, Bangladesh, and Guatemala indicated the mean equilibration time of 17 to 20 days irrespective of the size of hepatic reserves. Due to the controversy surrounding the efficacy of a carotene-rich diet on improvement of vitamin A status, the isotope dilution technique was proposed to pursue this research question further (IAEA's coordinated research program). In the Philippines, schoolchildren with low serum retinol concentrations showed significant improvement in total body vitamin A stores following intake of carotene-rich foods (orange fruits and vegetables), using a three-day deuterated-retinol-dilution procedure. When Chinese kindergarten children were fed green and yellow vegetables during the winter, their total body vitamin A stores were sustained as compared to a steady decline of vitamin A stores in the control children. Likewise, daily consumption of purified beta-carotene or diet rich in provitamin A carotenoids were shown to prevent a loss in total body vitamin A stores among Thai lactating women during the rice-planting season. These studies demonstrate potentials of the isotope dilution technique to evaluate the impact of provitamin A carotenoid intervention programs.

Weld Bead Geometry of Ni-Based Alloy Deposited by PTA Process for Pipe Conduction of Shale Gas

NASA Astrophysics Data System (ADS)

Echavarria-Figueroa, C.; García-Vázquez, F.; Ruiz-Mondragón, J.; Hernández-García, H. M.; González-González, D.; Vargas, A.

The transportation of shale gas has the problem that the piping used for the extraction does not resist the erosion generated by the amount of solids causing cracks over the surface and it is necessary to extend the life of the pipelines. Plasma transferred arc (PTA) welded coatings are used to improve the surface properties of mechanical parts. Therefore, in this paper is studied the use of Ni-based filler metal as weld bead deposits on A36 steel substrates by PTA. In order to determine the suitable conditions to ensure coating quality on the substrate a design of experiments (DOE) was determined. Welding current, feed rate, and travel speed were used as input parameters and the dilution percentage as the response variable. The composition and properties of hardfacing or overlay deposited are strongly influenced by the dilution obtained. Control of dilution is important, where typically low dilution is desirable. When the dilution is low, the final deposit composition will be closer to that of the filler metal, and the wear and corrosion resistance of the hardfacing will also be maintained. To evaluate the features on the weld beads/substrate interface a microstructural characterization was performed by using scanning electron microscopy and to evaluate the mechanical properties was carried out hardness test.

Quantitative Analysis by Isotopic Dilution Using Mass Spectroscopy: The Determination of Caffeine by GC-MS.

ERIC Educational Resources Information Center

Hill, Devon W.; And Others

1988-01-01

Describes a laboratory technique for quantitative analysis of caffeine by an isotopic dilution method for coupled gas chromatography-mass spectroscopy. Discusses caffeine analysis and experimental methodology. Lists sample caffeine concentrations found in common products. (MVL)

POLYSACCHARIDES FROM CELL WALLS OF AUREOBASIDIUM (PULLULARIA) PULLULANS. PART I. GLUCANS,

DTIC Science & Technology

The cell wall of Aureobasidium (Pullularia) pullulans contains three types of beta - glucan . One, extracted with dilute alkali, has a linear backbone...insoluble in dilute alkali contains a highly crystalline, essentially linear linked glucan and an amorphous glucan . (Author)

DIVERSE MODELS FOR SOLVING CONTRASTING OUTFALL PROBLEMS

EPA Science Inventory

Mixing zone initial dilution and far-field models are useful for assuring that water quality criteria will be met when specific outfall discharge criteria are applied. Presented here is a selective review of mixing zone initial dilution models and relatively simple far-field tran...

USING BIOPLUME IV TO MODEL SUSTAINABILITY OF MNA

EPA Science Inventory

At most sites where Monitored Natural Attenuation (MNA) has been selected as a remedy for ground water contamination, dilution and dispersion are not the primary mechanisms responsible for attenuation along the flow path in the aquifer. In most aquifers, dilution and dispersion ...

40 CFR 86.527-90 - Test procedures, overview.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 86.527-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... constant volume (variable dilution) sampler. (d) Except in cases of component malfunction or failure, all... emissions measurements are made. For exhaust testing, this requires sampling and analysis of the dilution...

Characterization and Behavior of Cold Lake Blend and Western Canadian Select Diluted Bitumen Products

EPA Science Inventory

Unconventional diluted bitumen (dilbit) oil products present an increasing environmental concern because of extensive transport in North America, recent spills into aquatic habitats, and limited understanding of environmental fate and toxicity. Dilbits are blends of highly weathe...

Microfocused Ultrasound with Visualization and Calcium Hydroxylapatite for Improving Skin Laxity and Cellulite Appearance

PubMed Central

Pereira, Gregório

2017-01-01

Background: Age-associated skin laxity contributes to worsening of cellulite appearance. This study evaluated the effects of microfocused ultrasound with visualization (MFU-V; Ultherapy) in combination with diluted calcium hydroxylapatite (CaHA; Radiesse) on cellulite appearance and on neocollagenesis. Methods: Twenty women (18–55 years old) with skin laxity and moderate-to-severe cellulite on the buttocks and thighs were retrospectively enrolled. MFU-V was applied using 4 and 7 MHz transducers (25 lines/transducer/site) and immediately followed by subdermal CaHA injection (1 ml/buttock or thigh). Photographs at baseline and 90 days were assessed by 2 independent, blinded evaluators using a 5-item cellulite severity scale. One subject scheduled for thighplasty received treatment with 6 different CaHA dilutions (0.3 ml/5 cm2) followed by MFU-V. Tissue specimens from each dilution site were examined under polarized light microscopy to assess neocollagenesis. Results: Both evaluators reported statistically significant improvements compared with baseline for each item on the cellulite severity scale (P < 0.001) with a 4.5-point improvement in mean overall score (P < 0.001) after a single MFU-V/CaHA treatment. At 90 days, histologic analysis showed peak neocollagenesis in samples treated with the 1:1 dilution, whether with CaHA alone or in combination with MFU-V. The highest conversion of collagen type III into collagen type I at month 3 occurred in samples injected with 1:1 and 1:0.6 CaHA dilutions without subsequent MFU-V treatment. Both procedures were well tolerated, and subject satisfaction was high. Conclusions: Combination treatment with MFU-V and diluted CaHA is effective for improving skin laxity and the appearance of cellulite on the buttocks and upper thighs. PMID:28831339

[The effect of selected antibiotics on microorganisms contaminating boar ejaculate].

PubMed

Mazurová, J; Vinter, P

1991-04-01

The occurrence of microorganisms, including their total counts in boar native ejaculates, was investigated in two stages; the objective of this investigation also was to determine contamination after the sperms were treated with diluents containing the antibiotics ampicillin, gentamycin, apramycin, cefoxitin, or antibiotic combinations penicillin + streptomycin, ampicillin + cefoxitin, gentamycin + cefoxitin and ampicillin + gentamycin. The representation of bacterial species and total counts of microbes in 1 ml diluted sperm stored at a temperature of about 18 degrees C were determined in 24, 48 and 72 h after dilution. The microorganisms were cultivated from all native ejaculates. Proteus sp. (63.3%) and Pseudomonas aeruginosa (51.5% of the total number of examined samples) were the most frequent species. The number of contaminated diluted ejaculates ranged from 12.5 to 95.8% in 24 h after dilution, from 12.5 to 98.5% in 48 h and from 16.8 to 95.8% of the total number of examined ejaculates in 72 h. The occurrence of microorganisms correlated mostly with the efficiency spectrum of the antibiotics or their combinations. The average counts of microorganisms in 1 ml of native ejaculate made 2,363,000 in stage I and 1,472,108 in stage II. The highest average counts in 1 ml of diluted sperm were found in ejaculates containing cefoxitin and apramycin. Gentamycin was the most effective antibiotic used as a sole component (average counts of microorganisms CPM in 1 ml were 416 in 24 h, 955 in 48 h and 2260 in 72 h after dilution); ampicillin and gentamycin were the most efficient combination (14--20--21). This combination exerted very good effects also on Proteus sp. and Pseudomonas aeruginosa.

Sperm cryopreservation of African catfish, Clarias gariepinus: cryoprotectants, freezing rates and sperm:egg dilution ratio.

PubMed

Viveiros, A T; So, N; Komen, J

2000-12-01

Methods for cryopreserving spermatozoa and optimizing sperm:egg dilution ratio in African catfish Clarias gariepinus were developed. Five percent to 25% DMSO and methanol were tested as cryoprotectants, by diluting semen in Ginzburg fish ringer and freezing in 1-milliliter cryovials in a programmable freezer. To avoid an excess of spermatozoa per egg, post-thaw semen was diluted 1:20, 1:200 or 1:2,000 before fertilization. Highest hatching rates were obtained by spermatozoa frozen in 10% methanol and post-thaw diluted to 1:200. Then, slow freezing rates (-2, -5 or -10 degrees C/min) to various endpoint temperatures (range -25 to -70 degrees C) before fast freezing in liquid nitrogen (LN2) were evaluated. Hatching rates equal to control (P > 0.05) were obtained by spermatozoa frozen at -5 degrees C/min to -45 to -50 degrees C and at -10 degrees C/min to -55 degrees C. In 3-step freezing programs, at -5 degrees C/min, the effect of holding spermatozoa for 0, 2 or 5 min at -30, -35 or -40 degrees C before fast freezing in LN2 was analyzed. Hatching rates equal to control (P > 0.05) were produced by spermatozoa frozen to, and held at, -35 degrees C for 5 min and at -40 degrees C for 2 or 5 min. Finally, frozen spermatozoa (10% methanol, -5 degrees C/min, 5-min hold at -40 degrees C, LN2, post-thaw diluted to 1:200) were tested in on-farm fertilization conditions. Again, no difference (P > 0.05) in hatching rate was observed between frozen and fresh spermatozoa. Cryopreservation offers utility as a routine method of sperm storage and management for catfish.

Effect of production management on semen quality during long-term storage in different European boar studs.

PubMed

Schulze, M; Kuster, C; Schäfer, J; Jung, M; Grossfeld, R

2018-03-01

The processing of ejaculates is a fundamental step for the fertilizing capacity of boar spermatozoa. The aim of the present study was to identify factors that affect quality of boar semen doses. The production process during 1 day of semen processing in 26 European boar studs was monitored. In each boar stud, nine to 19 randomly selected ejaculates from 372 Pietrain boars were analyzed for sperm motility, acrosome and plasma membrane integrity, mitochondrial activity and thermo-resistance (TRT). Each ejaculate was monitored for production time and temperature for each step in semen processing using the special programmed software SEQU (version 1.7, Minitüb, Tiefenbach, Germany). The dilution of ejaculates with a short-term extender was completed in one step in 10 AI centers (n = 135 ejaculates), in two steps in 11 AI centers (n = 158 ejaculates) and in three steps in five AI centers (n = 79 ejaculates). Results indicated there was a greater semen quality with one-step isothermal dilution compared with the multi-step dilution of AI semen doses (total motility TRT d7: 71.1 ± 19.2%, 64.6 ± 20.0%, 47.1 ± 27.1%; one-step compared with two-step compared with the three-step dilution; P < .05). There was a marked advantage when using the one-step isothermal dilution regarding time management, preservation suitability, stability and stress resistance. One-step dilution caused significant lower holding times of raw ejaculates and reduced the possible risk of making mistakes due to a lower number of processing steps. These results lead to refined recommendations for boar semen processing. Copyright © 2018 Elsevier B.V. All rights reserved.

Synergistic cosolubilization of omega-3 fatty acid esters and CoQ10 in dilutable microemulsions.

PubMed

Deutch-Kolevzon, Rivka; Aserin, Abraham; Garti, Nissim

2011-10-01

Water-dilutable microemulsions were prepared and loaded with two types of omega-3 fatty acid esters (omega-3 ethyl esters, OEE; and omega-3 triacylglycerides, OTG), each separately and together with ubiquinone (CoQ(10)). The microemulsions showed high and synergistic loading capabilities. The linear fatty acid ester (OEE) solubilization capacity was greater than that of the bulky and robust OTG. The location of the guest molecules within the microemulsions at any dilution point were determined by electrical conductivity, viscosity, DSC, SAXS, cryo-TEM, SD-NMR, and DLS. We found that OEE molecules pack well within the surfactant tails to form reverse micelles that gradually, upon water dilution, invert into bicontinuous phase and finally into O/W droplets. The CoQ(10) increases the stabilization and solubilization of the omega-3 fatty acid esters because it functions as a kosmotropic agent in the micellar system. The hydrophobic and bulky OTG molecule strongly interferes with the tail packing and spaces them significantly - mainly in the low and medium range water dilutions. When added to the micellar system, CoQ(10) forms some reverse hexagonal mesophases. The inversion into direct micelles is more difficult in comparison to the OEE system and requires additional water dilution. The OTG with or without CoQ(10) destabilizes the structures and decreases the solubilization capacity since it acts as a chaotropic agent to the micellar system and as a kosmotropic agent to hexagonal packing. These results explain the differences in the behavior of these molecules with vehicles that solubilize them in aqueous phases. Temperature disorders the bicontinuous structures and reduces the supersaturation of the system containing OEE with CoQ(10); as a result CoQ(10) crystallization is retarded. Copyright © 2011. Published by Elsevier Ireland Ltd.

Numerical simulations to assess the tracer dilution method for measurement of landfill methane emissions.

PubMed

Taylor, Diane M; Chow, Fotini K; Delkash, Madjid; Imhoff, Paul T

2016-10-01

Landfills are a significant contributor to anthropogenic methane emissions, but measuring these emissions can be challenging. This work uses numerical simulations to assess the accuracy of the tracer dilution method, which is used to estimate landfill emissions. Atmospheric dispersion simulations with the Weather Research and Forecast model (WRF) are run over Sandtown Landfill in Delaware, USA, using observation data to validate the meteorological model output. A steady landfill methane emissions rate is used in the model, and methane and tracer gas concentrations are collected along various transects downwind from the landfill for use in the tracer dilution method. The calculated methane emissions are compared to the methane emissions rate used in the model to find the percent error of the tracer dilution method for each simulation. The roles of different factors are examined: measurement distance from the landfill, transect angle relative to the wind direction, speed of the transect vehicle, tracer placement relative to the hot spot of methane emissions, complexity of topography, and wind direction. Results show that percent error generally decreases with distance from the landfill, where the tracer and methane plumes become well mixed. Tracer placement has the largest effect on percent error, and topography and wind direction both have significant effects, with measurement errors ranging from -12% to 42% over all simulations. Transect angle and transect speed have small to negligible effects on the accuracy of the tracer dilution method. These tracer dilution method simulations provide insight into measurement errors that might occur in the field, enhance understanding of the method's limitations, and aid interpretation of field data. Copyright © 2016 Elsevier Ltd. All rights reserved.

Congener-specific determination of ultratrace levels of chlorinated and brominated polycyclic aromatic hydrocarbons in atmosphere and industrial stack gas by isotopic dilution gas chromatography/high resolution mass spectrometry method.

PubMed

Jin, Rong; Liu, Guorui; Zheng, Minghui; Fiedler, Heidelore; Jiang, Xiaoxu; Yang, Lili; Wu, Xiaolin; Xu, Yang

2017-08-04

Isotopic dilution gas chromatography combined with high resolution mass spectrometry (GC/HRMS) has overwhelming advantages with respect to the accuracy of congener-specific ultratrace analysis of complex persistent organic pollutants (POPs) in environmental matrices. However, an isotopic dilution GC/HRMS method for analysis of chlorinated and brominated polycyclic aromatic hydrocarbons (Cl-PAHs and Br-PAHs) using 13 C-labelled congeners as internal standards has not been established. In this study, a method for identification and quantification of 38 congeners of Cl-PAHs and Br-PAHs in atmosphere and stack gas samples from waste incinerators was developed using the isotopic dilution GC/HRMS technique. The instrumental detection limits of the GC/HRMS method ranged from 0.2pg to 1.8pg for Cl-PAH congeners, and 0.7pg to 2.7pg for Br-PAH congeners, which were about three orders of magnitude lower than those of the GC/quadrupole MS method. This new method developed was also the first to enable determination of Cl-PAH and Br-PAH homologs comprising congeners with the same molecular skeleton and chlorine or bromine substitution numbers. Among the detected congeners, seven Cl-PAH congeners and thirteen Br-PAH congeners that were abundant in the atmosphere and stack gases released from waste incinerators were firstly detected in real samples and reported using the established isotopic dilution GC/HRMS method. The developed isotopic dilution GC/HRMS is significant and needed for better studying the environmental behavior and health risk of Cl-PAHs and Br-PAHs. Copyright © 2017 Elsevier B.V. All rights reserved.

Validation of dilution of plasma samples with phosphate buffered saline to eliminate the problem of small volumes associated with children infected with HIV-1 for viral load testing using Cobas AmpliPrep/COBAS TaqMan HIV-1 test, version 2.0 (CAP CTM HIV v2.0).

PubMed

Mine, Madisa; Nkoane, Tapologo; Sebetso, Gaseene; Sakyi, Bright; Makhaola, Kgomotso; Gaolathe, Tendani

2013-12-01

The sample requirement of 1 mL for the Roche COBAS AmpliPrep/COBAS TaqMan HIV-1 test, version 2.0 (CAP CTM HIV v2.0) limits its utility in measuring plasma HIV-1 RNA levels for small volume samples from children infected with HIV-1. Viral load monitoring is the standard of care for HIV-1-infected patients on antiretroviral therapy in Botswana. The study aimed to validate the dilution of small volume samples with phosphate buffered saline (1× PBS) when quantifying HIV-1 RNA in patient plasma. HIV RNA concentrations were determined in undiluted and diluted pairs of samples comprising panels of quality assessment standards (n=52) as well as patient samples (n=325). There was strong correlation (R(2)) of 0.98 and 0.95 within the dynamic range of the CAP CTM HIV v2.0 test between undiluted and diluted samples from quality assessment standards and patients, respectively. The difference between viral load measurements of diluted and undiluted pairs of quality assessment standards and patient samples using the Altman-Bland test showed that the 95% limits of agreement were between -0.40 Log 10 and 0.49 Log 10. This difference was within the 0.5 Log 10 which is generally considered as normal assay variation of plasma RNA levels. Dilution of samples with 1× PBS produced comparable viral load measurements to undiluted samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of brewery wastewater obtained from different phases of treatment plant on seed germination of chickpea (Cicer arietinum), maize (Zea mays), and pigeon pea (Cajanus cajan).

PubMed

Salian, Rupa; Wani, Suhas; Reddy, Ramamohan; Patil, Mukund

2018-03-01

Brewing industry releases large quantities of wastewater after product generation. Brewery wastewater contains organic compounds which are biodegradable in nature. These biodegradable wastes can be recycled and reused and hence considered as suitable products for agriculture. But before using wastewater for agriculture, it is better to evaluate the phytotoxic effects of wastewater on crops. Hence, the main objective of this study is to evaluate the effects of brewery effluent on seed germination and growth parameters of selected crop species like chickpea (Cicer arietinum), maize (Zea mays), and pigeon pea (Cajanus cajan). Study comprised seven types of water treatments-tap water as control, diluted UASBR effluent (50% effluent + 50% distilled water): UASBR50, undiluted UASBR effluent: UASBR100, diluted TC effluent (50% effluent + 50% distilled water): ETP50,TC effluent without dilution: ETP100, 10% diluted reverse osmosis (RO10) reject (10% RO reject + 90% distilled water), and 25% diluted reverse osmosis(RO25) reject (25% RO reject + 75% distilled water) with three replications in completely randomized design. Germination test was performed in petri plates for 5 days. Parameters like germination percentage, germination rate index, seedling length, phytotoxicity index, seed vigor index, and biomass were calculated. All parameters decreased with increase in respective effluent concentration. Among all treatments, RO25 showed highest inhibitory effect on all three crops. Even though undiluted effluent of UASBR and ETP effluent showed positive effect on germination, seedling growth of three crops was promoted to the maximum by UASBR50 and ETP50. Hence, from the study, it was concluded that dilution of brewery effluent can be recommended before using it for irrigational purpose.

Changes of jugular venous blood temperature associated with measurements of cerebral blood flow using the transcerebral double-indicator dilution technique.

PubMed

Mielck, F; Bräuer, A; Radke, O; Hanekop, G; Loesch, S; Friedrich, M; Hilgers, R; Sonntag, H

2004-04-01

The transcerebral double-indicator dilution technique is a recently developed method to measure global cerebral blood flow at bedside. It is based on bolus injection of ice-cold indocyanine green dye and simultaneous recording of resulting thermo- and dye-dilution curves in the aorta and the jugular bulb. However, with this method 40 mL of ice-cold solution is administered as a bolus. Therefore, this prospective clinical study was performed to elucidate the effects of repeated administration of indicator on absolute blood temperature and on cerebral blood flow and metabolism. The investigation was performed in nine male patients scheduled for elective coronary artery bypass grafting. Absolute blood temperature was measured in the jugular bulb and in the aorta before and after repeated measurements using the transcerebral double-indicator dilution technique. During the investigated time course, the blood temperature in the jugular bulb, compared to the aorta, was significantly higher with a mean difference of 0.21 degrees C. The administration of an ice-cold bolus reduced the mean blood temperature by 0.06 degrees C in the jugular bulb as well as in the aorta. After the transcerebral double-indicator dilution measurements a temperature recovery to baseline conditions was not observed during the investigated time period. Cerebral blood flow and cerebral metabolism did not change during the investigated time period. Repeated measurements with the transcerebral double-indicator dilution technique do not affect absolute jugular bulb blood temperatures negatively. Global cerebral blood flow and metabolism measurements remain unaltered. However, accuracy and resolution of this technique is not high enough to detect the effect of minor changes of physiological variables.

The use of animal models in homeopathic research--a review of 2010-2014 PubMed indexed papers.

PubMed

Bonamin, Leoni Villano; Cardoso, Thayná Neves; de Carvalho, Aloísio Cunha; Amaral, Juliana Gimenez

2015-10-01

In the 1990s, a study was performed on the effects of highly diluted thyroxine on frog metamorphosis. This model represented one of the most discussed examples of the biological effects of high dilutions over the next two decades. In 2010, another critical conceptual review of the use of animal models in homeopathy and high-dilution research was published. The main contribution of these studies was the elucidation of the biological features and phenomenology of the effects of high dilutions on living systems, representing an important step forward in our understanding of the mechanisms of action of homeopathic medicines. We performed a further review of this line of investigation using the same methods. Fifty-three articles that were indexed in the PubMed database and used 12 different animal species were systematically evaluated. Only a fraction of the studies (29/53) reported herein were performed with "ultra high" dilutions. The other studies were performed with dilutions in ranges below 10(-23) (14/53 articles) or commercial complexes (10/53 articles). Only two articles reported negative results; both used in vivo protocols to test commercial complexes, one in fish and one in bees. The quality of the employed techniques improved in 2010-2014 compared with the studies that were reviewed previously in 2010, with the inclusion of more ethically refined protocols, including in vitro primary cell cultures and ex vivo studies (10/53 articles), often with three or more replicates and analyses of epigenetic mechanisms that were previously unknown in 2010. In our updated review of the past 5 years, we found further demonstrations of the biological effects of homeopathy using more refined animal models and in vitro techniques. Copyright © 2015 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Characterization of ultrafiltration of undiluted and diluted stored urine.

PubMed

Ouma, J; Septien, S; Velkushanova, K; Pocock, J; Buckley, C

2016-11-01

Urine ultrafiltration (UF) was studied in terms of flux, permeability, resistance and fouling. Two types of samples were used: stored urine representing the feedstock obtained from urine diversion dry toilets; and diluted stored urine representing the feedstock obtained from urinals. Three different filtration experiment sets were adopted in this study. For the first case, pressure was set in an ascending order, i.e. from 10 to 60 kPa during filtration of stored urine. For the second case, pressure was set in a descending order, i.e. from 60 to 10 kPa for the same feed stream. The third case involved filtration of diluted urine with pressure in ascending order, i.e. from 10 to 60 kPa. The results indicated that diluted urine had higher flux than undiluted urine with maximum values of 43 and 26 L·m -2 ·h -1 respectively. Cake formation was the dominating fouling mechanism during urine filtration with a contribution of about 90% to the total hydraulic resistance. The contribution of chemically irreversible fouling was low (-2%), unless operating from high to low pressures. Indeed, irreversible fouling appeared to be greater during the experiments starting at higher pressure. Although undiluted urine had a higher fouling potential compared to diluted urine, the specific cake resistance was higher for diluted urine, probably due to a denser cake caused by lower particle sizes in that sample. The permeate obtained after urine filtration had much lower suspended solids content compared to the feedstock, with rejections up to 99%. The concentration of the ionic species remained unchanged, and 75% of the organic compounds and dissolved solids remained in the permeate. Urine UF could then be used as pre-treatment to remove suspended solids.

Improving hydrolysis of food waste in a leach bed reactor

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

Browne, James D.; Allen, Eoin; Murphy, Jerry D., E-mail: jerry.murphy@ucc.ie

2013-11-15

Highlights: • This paper assesses leaching of food waste in a two phase digestion system. • Leaching is assessed with and without an upflow anaerobic sludge blanket (UASB). • Without the UASB, low pH reduces hydrolysis, while increased flows increase leaching. • Inclusion of the UASB increases pH to optimal levels and greatly improves leaching. • The optimal conditions are suggested as low flow with connection to the UASB. - Abstract: This paper examines the rate of degradation of food waste in a leach bed reactor (LBR) under four different operating conditions. The effects of leachate recirculation at a lowmore » and high flow rate are examined with and without connection to an upflow anaerobic sludge blanket (UASB). Two dilution rates of the effective volume of the leach bed reactors were investigated: 1 and 6 dilutions per LBR per day. The increase in dilution rate from 1 to 6 improved the destruction of volatile solids without connection to the UASB. However connection to the UASB greatly improved the destruction of volatile solids (by almost 60%) at the low recirculation rate of 1 dilution per day. The increase in volatile solids destruction with connection to the UASB was attributed to an increase in leachate pH and buffering capacity provided by recirculated effluent from the UASB to the leach beds. The destruction of volatile solids for both the low and high dilution rates was similar with connection to the UASB, giving 82% and 88% volatile solids destruction respectively. This suggests that the most efficient leaching condition is 1 dilution per day with connection to the UASB.« less

Distributed combustion in a cyclonic burner

NASA Astrophysics Data System (ADS)

Sorrentino, Giancarlo; Sabia, Pino; de Joannon, Mara; Cavaliere, Antonio; Ragucci, Raffaele

2017-11-01

Distributed combustion regime occurs in several combustion technologies were efficient and environmentally cleaner energy conversion are primary tasks. For such technologies (MILD, LTC, etc…), working temperatures are enough low to boost the formation of several classes of pollutants, such as NOx and soot. To access this temperature range, a significant dilution as well as preheating of reactants is required. Such conditions are usually achieved by a strong recirculation of exhaust gases that simultaneously dilute and pre-heat the fresh reactants. However, the intersection of low combustion temperatures and highly diluted mixtures with intense pre-heating alters the evolution of the combustion process with respect to traditional flames, leading to significant features such as uniformity and distributed ignition. The present study numerically characterized the turbulence-chemistry and combustion regimes of propane/oxygen mixtures, highly diluted in nitrogen, at atmospheric pressure, in a cyclonic combustor under MILD Combustion operating conditions. The velocity and mixing fields were obtained using CFD with focus on mean and fluctuating quantities. The flow-field information helped differentiate between the impact of turbulence levels and dilution ones. The integral length scale along with the fluctuating velocity is critical to determine Damköhler and Karlovitz numbers. Together these numbers identify the combustion regime at which the combustor is operating. This information clearly distinguishes between conventional flames and distributed combustion. The results revealed that major controllers of the reaction regime are dilution and mixing levels; both are significantly impacted by lowering oxygen concentration through entrainment of hot reactive species from within the combustor, which is important in distributed combustion. Understanding the controlling factors of distributed regime is critical for the development and deployment of these novel combustion technologies for near zero emissions from high intensity combustors and energy savings using fossil and biofuels for sustainable energy conversion.

Evaluation and reporting of enzyme immunoassay determinations of antibody to herpes simplex virus in sera and cerebrospinal fluid.

PubMed Central

Cremer, N E; Cossen, C K; Hanson, C V; Shell, G R

1982-01-01

Several methods for evaluating and reporting enzyme immunoassay (EIA) determinations of antibody to herpes simplex virus derived from one dilution of single serum samples were studied. An EIA ratio method for serological evidence of current infection from paired serum samples was also evaluated. Optical density (OD) of the reaction at a 1:100 serum dilution and estimated titers obtained by reference of the OD of the serum dilution to a standard curve were compared to the corresponding plotted EIA titer obtained by titration to endpoint. Neither the OD per se nor the estimated titer was completely predictive of the plotted titer (correlation coefficient [r] of 0.824 and 0.817, respectively), and they provided only a semiquantitative measurement of antibody concentration. For an antibody status report, however, OD would be sufficient if related to the cutoff value as an EIA index (OD of sample divided by cutoff OD for positive specimens). The OD of the EIA reaction at a single dilution (1:5) of cerebrospinal fluid, on the other hand, correlated quite well with the titer obtained by titration (r = 0.950). For serological diagnosis of current infection, the OD ratio of convalescence-phase/acute-phase sera was determined at several dilutions. A ratio of greater than or equal to 1.54 was calculated as a reliable index for a significant rise in antibody concentration and compatible with current infection. By determining the convalescent-phase/acute-phase serum ratio at two dilutions, 1:100 and 1:1,000, the EIA ratio method appeared to be a sensitive as or more sensitive than, complement fixation in diagnosing current infection. PMID:6284791

40 CFR 156.146 - Residue removal instructions for nonrefillable containers-rigid containers with dilutable...

Code of Federal Regulations, 2011 CFR

2011-07-01

... nonrefillable containers-rigid containers with dilutable pesticides. 156.146 Section 156.146 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS LABELING REQUIREMENTS FOR PESTICIDES AND DEVICES Container Labeling § 156.146 Residue removal instructions for nonrefillable containers...

40 CFR 156.146 - Residue removal instructions for nonrefillable containers-rigid containers with dilutable...

Code of Federal Regulations, 2014 CFR

2014-07-01

... nonrefillable containers-rigid containers with dilutable pesticides. 156.146 Section 156.146 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS LABELING REQUIREMENTS FOR PESTICIDES AND DEVICES Container Labeling § 156.146 Residue removal instructions for nonrefillable containers...

40 CFR 156.146 - Residue removal instructions for nonrefillable containers-rigid containers with dilutable...

Code of Federal Regulations, 2013 CFR

2013-07-01

... nonrefillable containers-rigid containers with dilutable pesticides. 156.146 Section 156.146 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS LABELING REQUIREMENTS FOR PESTICIDES AND DEVICES Container Labeling § 156.146 Residue removal instructions for nonrefillable containers...

40 CFR 156.146 - Residue removal instructions for nonrefillable containers-rigid containers with dilutable...

Code of Federal Regulations, 2012 CFR

2012-07-01

... nonrefillable containers-rigid containers with dilutable pesticides. 156.146 Section 156.146 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS LABELING REQUIREMENTS FOR PESTICIDES AND DEVICES Container Labeling § 156.146 Residue removal instructions for nonrefillable containers...

Reusable chelating resins concentrate metal ions from highly dilute solutions

NASA Technical Reports Server (NTRS)

Bauman, A. J.; Weetal, H. H.; Weliky, N.

1966-01-01

Column chromatographic method uses new metal chelating resins for recovering heavy-metal ions from highly dilute solutions. The absorbed heavy-metal cations may be removed from the chelating resins by acid or base washes. The resins are reusable after the washes are completed.

Dilution, Concentration, and Flotation

ERIC Educational Resources Information Center

Liang, Ling; Schmuckler, Joseph S.

2004-01-01

As both classroom teaching practice and literature show, many students have difficulties learning science concepts such as density. Here are some investigations that identify the relationship between density and floating through experimenting with successive dilution of a liquid, or the systematic change of concentration of a saltwater solution.…

US researchers study effectiveness of Fluidized Sand Biofilters

USDA-ARS?s Scientific Manuscript database

Intensive aquaculture facilities generally produce two separate waste flows: 1) a high volume dilute discharge from culture tanks or pump sumps, and 2) a moderately small and solids-concentrated discharge typically backwashed from mechanical filtration units. The high volume dilute flow can appear p...

USING BIOPLUME IV TO MODEL SUSTAINABILITY OF MNA (ABSTRACT ONLY)

EPA Science Inventory

At most sites where Monitored Natural Attenuation (MNA) has been selected as a remedy for ground water contamination, dilution and dispersion are not the primary mechanisms responsible for attenuation along the flow path in the aquifer. In most aquifers, dilution and dispersion ...

Performance characteristics of constant-flow phase dilution oxygen mask designs for general aviation.

DOT National Transportation Integrated Search

1967-05-01

The report describes evaluation of two prototype phase dilution rebreathing masks as compared to an open port rebreathing mask design. Human subjects wearing the prototype masks and engaged in three minute periods of rest and exercise were exposed to...

Study the Effect of SiO2 Based Flux on Dilution in Submerged Arc Welding

NASA Astrophysics Data System (ADS)

kumar, Aditya; Maheshwari, Sachin

2017-08-01

This paper highlights the method for prediction of dilution in submerged arc welding (SAW). The most important factors of weld bead geometry are governed by the weld dilution which controls the chemical and mechanical properties. Submerged arc welding process is used generally due to its very easy control of process variables, good penetration, high weld quality, and smooth finish. Machining parameters, with suitable weld quality can be achieved with the different composition of the flux in the weld. In the present study Si02-Al2O3-CaO flux system was used. In SiO2 based flux NiO, MnO, MgO were mixed in various proportions. The paper investigates the relationship between the process parameters like voltage, % of flux constituents and dilution with the help of Taguchi’s method. The experiments were designed according to Taguchi L9 orthogonal array, while varying the voltage at two different levels in addition to alloying elements. Then the optimal results conditions were verified by confirmatory experiments.

What infusion flow should be used for mid-dilution hemodiafiltration?

PubMed

Maduell, Francisco; Arias, Marta; Fontseré, Néstor; Vera, Manel; Masso, Elisabeth; Garro, Julia; Barros, Xoana; Martina, Maria N; Elena, Montserrat; Bergadá, Eduardo; Cases, Aleix; Bedini, Jose Luis; Campistol, Josep M

2010-01-01

There is still no consensus on the optimal infusion flow (Qi) in mid-dilution hemodiafiltration. The aim of this study was to compare mid-dilution with varying Qi. Prospective study in 25 patients who underwent seven hemodialysis sessions with a Qi of 0, 50, 100, 150, 200, 250 and 300 ml/min. All sessions were well tolerated except Qi 300 ml/min. No significant differences in urea, creatinine, alpha(1)-microglobulin or alpha(1)-acid glycoprotein reduction ratios were observed. beta(2)-Microglobulin, myoglobin and prolactin reduction ratios were higher with Qi 150, 200, 250 and 300 ml/min in comparison with Qi of 0, 50 and 100 ml/min. There were no differences in the removal of small or larger molecules when Qi was 150 ml/min or higher. Optimal Qi in mid-dilution appears to be in the range of 150-250 ml/min since good clinical outcomes, similar efficiency and no technical complications up to a Qi of 250 ml/min were observed.

Anti-site-induced diverse diluted magnetism in LiMgPdSb-type CoMnTiSi alloy

NASA Astrophysics Data System (ADS)

Lin, T. T.; Dai, X. F.; Guo, R. K.; Cheng, Z. X.; Wang, L. Y.; Wang, X. T.; Liu, G. D.

2017-02-01

The effect of three kinds of anti-site disorder to electronic structure and magnetic properties of the LiMgPdSb-type CoMnTiSi alloy are investigated. It was found the Mn-Ti anti-site disorder can induce the diluted magnetism in CoMnTiSi matrix. The magnetic structure has an oscillation between the ferromagnetic and antiferromagnetic states with the different degree of Mn-Ti anti-site disorder. Two novel characteristics: the diluted antiferromagnetic half-metallicity and the diluted zero-gap half-metallity are found in the different degree range of the Mn-Ti anti-site disorder. The Co-Mn and Co-Ti anti-site disorder have little effect on the magnetic properties. The width of energy gap and the intensity of DOS at the Fermi level can be adjusted by the degree of Co-Mn or Co-Ti anti-site disorder. The independent control to the carrier concentration and magnetization can be realized by introducing the different anti-site disorder.

A generic template for automated bioanalytical ligand-binding assays using modular robotic scripts in support of discovery biotherapeutic programs.

PubMed

Duo, Jia; Dong, Huijin; DeSilva, Binodh; Zhang, Yan J

2013-07-01

Sample dilution and reagent pipetting are time-consuming steps in ligand-binding assays (LBAs). Traditional automation-assisted LBAs use assay-specific scripts that require labor-intensive script writing and user training. Five major script modules were developed on Tecan Freedom EVO liquid handling software to facilitate the automated sample preparation and LBA procedure: sample dilution, sample minimum required dilution, standard/QC minimum required dilution, standard/QC/sample addition, and reagent addition. The modular design of automation scripts allowed the users to assemble an automated assay with minimal script modification. The application of the template was demonstrated in three LBAs to support discovery biotherapeutic programs. The results demonstrated that the modular scripts provided the flexibility in adapting to various LBA formats and the significant time saving in script writing and scientist training. Data generated by the automated process were comparable to those by manual process while the bioanalytical productivity was significantly improved using the modular robotic scripts.

Mobil-Badger technologies for benzene reduction in gasoline

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

Goelzer, A.R.; Ram, S.; Hernandez, A.

1993-01-01

Many refiners will need to reduce the barrels per day of benzene entering the motor gasoline pool. Mobil and Badger have developed and now jointly license three potential refinery alternatives to conventional benzene hydrosaturation to achieve this: Mobil Benzene Reduction, Ethylbenzene and Cumene. The Mobil Benzene Reduction Process (MBR) uses dilute olefins in FCC offgas to extensively alkylate dilute benzene as found in light reformate, light FCC gasoline, or cyclic C[sub 6] naphtha. MBR raises octanes and lowers C[sub 5]+ olefins. MBR does not involve costly hydrogen addition. The refinery-based Mobil/Badger Ethylbenzene Process reacts chemical-grade benzene extracted from light reformatemore » with dilute ethylene found in treated FCC offgas to make high-purity ethylbenzene. EB is the principal feedstock for the production of styrene. The Mobil/Badger Cumene Process alkylates FCC-derived dilute propylene and extracted benzene to selectively yield isopropyl benzene (cumene). Cumene is the principal feedstock for the production of phenol. All three processes use Mobil developed catalysts.« less

Ficts and facts of epinephrine and norepinephrine stability in injectable solutions.

PubMed

Hoellein, Ludwig; Holzgrabe, Ulrike

2012-09-15

Epinephrine (EPI) and norepinephrine (NE) play an important role in emergency medicine and acute treatment of hypotension and shocks in the intensive care unit. Injectable solutions can either be provided as proprietary medicinal products or as individually prepared dilutions. Due to the chemical structure of EPI and NE, the stability of the corresponding solutions is limited. Thus, most manufacturers of EPI and NE injectable solutions use sulfites and nitrogen for stabilization, Nevertheless, storage conditions such as temperature and light have to be considered, but are often neglected in the daily hospital routine. In addition, hospital pharmacies prepare EPI and NE solutions and dilute commercially available solutions for individual therapy, especially on ICUs. Since the influence of dilution and the presence of excipients and other preservatives are not systematically explored, we collected published data and investigations on stability on the potency of EPI and NE injectable solutions in order to deduce storage recommendations for diluted EPI and NE solutions of different concentration. Copyright © 2012 Elsevier B.V. All rights reserved.

ESTIMATION OF THE NUMBER OF INFECTIOUS BACTERIAL OR VIRAL PARTICLES BY THE DILUTION METHOD

PubMed Central

Seligman, Stephen J.; Mickey, M. Ray

1964-01-01

Seligman, Stephen J. (University of California, Los Angeles), and M. Ray Mickey. Estimation of the number of infectious bacterial or viral particles by the dilution method. J. Bacteriol. 88:31–36. 1964.—For viral or bacterial systems in which discrete foci of infection are not obtainable, it is possible to obtain an estimate of the number of infectious particles by use of the quantal response if the assay system is such that one infectious particle can elicit the response. Unfortunately, the maximum likelihood estimate is difficult to calculate, but, by the use of a modification of Haldane's approximation, it is possible to construct a table which facilitates calculation of both the average number of infectious particles and its relative error. Additional advantages of the method are that the number of test units per dilution can be varied, the dilutions need not bear any fixed relation to each other, and the one-particle hypothesis can be readily tested. PMID:14197902

Ab initio calculations of the concentration dependent band gap reduction in dilute nitrides

NASA Astrophysics Data System (ADS)

Rosenow, Phil; Bannow, Lars C.; Fischer, Eric W.; Stolz, Wolfgang; Volz, Kerstin; Koch, Stephan W.; Tonner, Ralf

2018-02-01

While being of persistent interest for the integration of lattice-matched laser devices with silicon circuits, the electronic structure of dilute nitride III/V-semiconductors has presented a challenge to ab initio computational approaches. The origin of the computational problems is the strong distortion exerted by the N atoms on most host materials. Here, these issues are resolved by combining density functional theory calculations based on the meta-GGA functional presented by Tran and Blaha (TB09) with a supercell approach for the dilute nitride Ga(NAs). Exploring the requirements posed to supercells, it is shown that the distortion field of a single N atom must be allowed to decrease so far that it does not overlap with its periodic images. This also prevents spurious electronic interactions between translational symmetric atoms, allowing us to compute band gaps in very good agreement with experimentally derived reference values. In addition to existing approaches, these results offer a promising ab initio avenue to the electronic structure of dilute nitride semiconductor compounds.

Water Quality Planning in Rivers: Assimilative Capacity and Dilution Flow.

PubMed

Hashemi Monfared, Seyed Arman; Dehghani Darmian, Mohsen; Snyder, Shane A; Azizyan, Gholamreza; Pirzadeh, Bahareh; Azhdary Moghaddam, Mehdi

2017-11-01

Population growth, urbanization and industrial expansion are consequentially linked to increasing pollution around the world. The sources of pollution are so vast and also include point and nonpoint sources, with intrinsic challenge for control and abatement. This paper focuses on pollutant concentrations and also the distance that the pollution is in contact with the river water as objective functions to determine two main necessary characteristics for water quality management in the river. These two necessary characteristics are named assimilative capacity and dilution flow. The mean area of unacceptable concentration [Formula: see text] and affected distance (X) are considered as two objective functions to determine the dilution flow by a non-dominated sorting genetic algorithm II (NSGA-II) optimization algorithm. The results demonstrate that the variation of river flow discharge in different seasons can modify the assimilation capacity up to 97%. Moreover, when using dilution flow as a water quality management tool, results reveal that the content of [Formula: see text] and X change up to 97% and 93%, respectively.

Diluted povidone-iodine versus saline for dressing metal-skin interfaces in external fixation.

PubMed

Chan, C K; Saw, A; Kwan, M K; Karina, R

2009-04-01

To compare infection rates associated with 2 dressing solutions for metal-skin interfaces. 60 patients who underwent distraction osteogenesis with external fixators were equally randomised into 2 dressing solution groups (diluted povidone-iodine vs. saline). Fixations were attained using either rigid stainless steel 5-mm diameter half pins or smooth stainless steel 1.8-mm diameter wires. Half-pin fixation had one metal-skin interface, whereas wire fixation had 2 interfaces. Patients were followed up every 2 weeks for 6 months. Of all 788 metal-skin interfaces, 143 (18%) were infected: 72 (19%) of 371 in the diluted povidone-iodine group and 71 (17%) of 417 in the saline group. Dressing solution and patient age did not significantly affect infection rates. Half-pin fixation was more likely to become infected than wire fixation (25% vs 15%). Saline is as effective as diluted povidone-iodine as a dressing solution for metal-skin interfaces of external fixators. Saline is recommended in view of its easy availability and lower costs.

Breakdown of cell wall nanostructure in dilute acid pretreated biomass.

PubMed

Pingali, Sai Venkatesh; Urban, Volker S; Heller, William T; McGaughey, Joseph; O'Neill, Hugh; Foston, Marcus; Myles, Dean A; Ragauskas, Arthur; Evans, Barbara R

2010-09-13

The generation of bioethanol from lignocellulosic biomass holds great promise for renewable and clean energy production. A better understanding of the complex mechanisms of lignocellulose breakdown during various pretreatment methods is needed to realize this potential in a cost and energy efficient way. Here we use small-angle neutron scattering (SANS) to characterize morphological changes in switchgrass lignocellulose across molecular to submicrometer length scales resulting from the industrially relevant dilute acid pretreatment method. Our results demonstrate that dilute acid pretreatment increases the cross-sectional radius of the crystalline cellulose fibril. This change is accompanied by removal of hemicellulose and the formation of R(g) ∼ 135 A lignin aggregates. The structural signature of smooth cell wall surfaces is observed at length scales larger than 1000 A, and it remains remarkably invariable during pretreatment. This study elucidates the interplay of the different biomolecular components in the breakdown process of switchgrass by dilute acid pretreatment. The results are important for the development of efficient strategies of biomass to biofuel conversion.

Construction and operation of a 10 cfm (cubic feet per minute) sampling system with a 10:1 dilution ratio for measuring condensable emissions. Final report

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

Steele, W.J.; Williamson, A.D.; McCain, J.D.

1988-04-01

The report describes a transportable sampling apparatus designed to sample incineration sources at municipal and hazardous-waste disposal facilities, and to provide non-contaminated samples of condensable materials. The sample gas, at a flow rate of 10 cubic feet per minute (c f/m), passes through a modified Source Assessment Sampling System (SASS) cyclone and is then diluted with clean air at 100 cf/m by a novel, perforated cone assembly. Rapid uniform dilution takes place through the vigorous mixing of the sample and clean air streams in the dilution chamber. The resultant gas, cooled to about atmospheric conditions, is passed through a mixingmore » section that provides a residence time of about 3 seconds. The resulting aerosol particles are collected on a Teflon-coated glass-fiber filter. These solids, along with those collected in the cyclone, are subsequently provided for chemical and biological assay analysis.« less

Odorant Screening and Quantitation of Thiols in Carmenere Red Wine by Gas Chromatography-Olfactometry and Stable Isotope Dilution Assays.

PubMed

Pavez, Carolina; Agosin, Eduardo; Steinhaus, Martin

2016-05-04

The sensory impact of thiols in Vitis vinifera 'Carmenere' red wines was evaluated. For this purpose, aroma extract dilution analysis was applied to the thiols isolated from a Carmenere red wine by affinity chromatography with a mercurated agarose gel. Results revealed the presence of four odorants, identified as 2-furanylmethanethiol, 3-sulfanylhexyl acetate, 3-sulfanyl-1-hexanol, and 2-methyl-3-sulfanyl-1-butanol, with the latter being described here for the first time in Carmenere red wines. Quantitation of the four thiols in the Carmenere wine screened by aroma extract dilution analysis and in three additional Carmenere wines by stable isotope dilution assays resulted in concentrations above the respective orthonasal odor detection threshold values. Triangle tests applied to wine model solutions with and without the addition of the four thiols showed significant differences, thus suggesting that the compounds do have the potential to influence the overall aroma of red wine.

Numerical simulation and optimization of red mud separation thickener with self-dilute feed

DOE PAGES

Zhou, Tian; Li, Mao; Zhou, Chenn-qian; ...

2014-03-01

In order to acquire the flow pattern and investigate the settling behavior of the red mud in the separation thickener, computational fluid dynamics (CFD), custom subroutines and agglomerates settling theory were employed to simulate the three-dimensional flow field in an industrial scale thickener with the introduction of a self-dilute feed system. Our simulation results show good agreement with the measurement onsite and the flow patterns of the thickener are presented and discussed on both velocity and concentration field. Optimization experiments on feed well and self-dilute system were also carried out, and indicate that the optimal thickener system can dilute themore » solid concentration in feed well from 110 g/L to 86 g/L which would help the agglomerates’ formation and improve the red mud settling speed. The additional power of recirculation pump can be saved and flocculants dosage was reduced from 105g/t to 85g/t in the operation.« less

Infinitely dilute partial molar properties of proteins from computer simulation.

PubMed

Ploetz, Elizabeth A; Smith, Paul E

2014-11-13

A detailed understanding of temperature and pressure effects on an infinitely dilute protein's conformational equilibrium requires knowledge of the corresponding infinitely dilute partial molar properties. Established molecular dynamics methodologies generally have not provided a way to calculate these properties without either a loss of thermodynamic rigor, the introduction of nonunique parameters, or a loss of information about which solute conformations specifically contributed to the output values. Here we implement a simple method that is thermodynamically rigorous and possesses none of the above disadvantages, and we report on the method's feasibility and computational demands. We calculate infinitely dilute partial molar properties for two proteins and attempt to distinguish the thermodynamic differences between a native and a denatured conformation of a designed miniprotein. We conclude that simple ensemble average properties can be calculated with very reasonable amounts of computational power. In contrast, properties corresponding to fluctuating quantities are computationally demanding to calculate precisely, although they can be obtained more easily by following the temperature and/or pressure dependence of the corresponding ensemble averages.

ANTIGEN-INDUCED CHANGES IN LYMPHOID CELL HISTONES

PubMed Central

Black, Maurice M.; Ansley, Hudson R.

1967-01-01

In this study we have examined the solubility of deoxyribonucleoprotein (DNP) isolated from control and antigen-affected thymocytes. 2-M sodium chloride extracts containing the DNP of rat thymus glands were serially diluted. A comparison was made of the effect of dilution on fiber formation in the control and test series. Fiber formation is usually complete for the control material at a salt concentration between 0.63 and 0.57 M. The test material shows some fiber formation within this range. However, a significant portion of the DNP is precipitated at dilutions of 0.54–0.48 M. Ammoniacal silver (A-S) stains the control fibers a characteristic yellowish color. With the test material, those fibers formed within the control range tended to be stained yellowish brown by A-S, whereas those formed only after greater dilution stained blackish. These data, coupled with our previous observations on altered A-S staining, clearly demonstrate an antigen-induced physical and/or chemical alteration of the histone or histone-DNA complex of lymphoid cell chromatin. PMID:4168881

Effects of Dilute Acid Pretreatment on Cellulose DP and the Relationship Between DP Reduction and Cellulose Digestibility

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

Wang, W.; Chen, X.; Tucker, M.

2012-01-01

The degree of polymerization(DP) of cellulose is considered to be one of the most important properties affecting the enzymatic hydrolysis of cellulose. Various pure cellulosic and biomass materials have been used in a study of the effect of dilute acid treatment on cellulose DP. A substantial reduction in DP was found for all pure cellulosic materials studied even at conditions that would be considered relatively mild for pretreatment. The effect of dilute acid pretreatment on cellulose DP in biomass samples was also investigated. Corn stover pretreated with dilute acid under the most optimal conditions contained cellulose with a DPw inmore » the range of 1600{approx}3500, which is much higher than the level-off DP(DPw 150{approx}300) obtained with pure celluloses. The effect of DP reduction on the saccharification of celluloses was also studied. From this study it does not appear that cellulose DP is a main factor affecting cellulose saccharification.« less

Consideration of some dilute-solution phenomena based on an expression for the Gibbs free energy

NASA Astrophysics Data System (ADS)

Jonah, D. A.

1986-07-01

Rigorous expressions based on the Lennard-Jones (6 12) potential, are presented for the Gibbs and Helmholtz free energy of a dilute mixture. These expressions give the free energy of the mixture in terms of the thermodynamic properties of the pure solvent, thereby providing a convenient means of correlating dilute mixture behavior with that of the pure solvent. Expressions for the following dilute binary solution properties are derived: Henry's constant, limiting activity coefficients with their derivatives, solid solubilities in supercritical gases, and mixed second virial coefficients. The Henry's constant expression suggests a linear temperature dependence; application to solubility data for various gases in methane and water shows a good agreement between theory and experiment. In the thermodynamic modeling of supercritical fluid extraction, we have demonstrated how to predict new solubility-pressure isotherms from a given isotherm, with encouraging results. The mixed second virial coefficient expression has also been applied to experimental data; the agreement with theory is good.

Suppression of dilution in Ni-Cr-Si-B alloy cladding layer by controlling diode laser beam profile

NASA Astrophysics Data System (ADS)

Tanigawa, Daichi; Funada, Yoshinori; Abe, Nobuyuki; Tsukamoto, Masahiro; Hayashi, Yoshihiko; Yamazaki, Hiroyuki; Tatsumi, Yoshihiro; Yoneyama, Mikio

2018-02-01

A Ni-Cr-Si-B alloy layer was produced on a type 304 stainless steel plate by laser cladding. In order to produce cladding layer with smooth surface and low dilution, influence of laser beam profile on cladding layer was investigated. A laser beam with a constant spatial intensity at the focus spot was used to suppress droplet formation during the cladding layer formation. This line spot, formed with a focussing unit designed by our group, suppressed droplet generation. The layer formed using this line spot with a constant spatial intensity had a much smoother surface compared to a layer formed using a line spot with a Gaussian-like beam. In addition, the dilution of the former layer was much smaller. These results indicated that a line spot with a constant spatial intensity was more effective in producing a cladding layer with smooth surface and low dilution because it suppressed droplet generation.

The (Conditional) Resource Dilution Model: State- and Community-Level Modifications.

PubMed

Gibbs, Benjamin G; Workman, Joseph; Downey, Douglas B

2016-06-01

One of the most consistent patterns in the social sciences is the relationship between sibship size and educational outcomes: those with fewer siblings outperform those with many. The resource dilution (RD) model emphasizes the increasing division of parental resources within the nuclear family as the number of children grows, yet it fails to account for instances when the relationship between sibship size and education is often weak or even positive. To reconcile, we introduce a conditional resource dilution (CRD) model to acknowledge that nonparental investments might aid in children's development and condition the effect of siblings. We revisit the General Social Surveys (1972-2010) and find support for a CRD approach: the relationship between sibship size and educational attainment has declined during the first half of the twentieth century, and this relationship varies across religious groups. Findings suggest that state and community resources can offset the impact of resource dilution-a more sociological interpretation of sibship size patterns than that of the traditional RD model.

Mixotrophic growth and biochemical analysis of Chlorella vulgaris cultivated with diluted monosodium glutamate wastewater.

PubMed

Ji, Yan; Hu, Wenrong; Li, Xiuqing; Ma, Guixia; Song, Mingming; Pei, Haiyan

2014-01-01

Monosodium glutamate wastewater (MSGW) is a potential medium for microbial cultivation because of containing abundant organic nutrient. This paper seeks to evaluate the feasibility of growing Chlorella vulgaris with MSGW and assess the influence of MSGW concentration on the biomass productivity and biochemical compositions. The MSGW diluted in different concentrations was prepared for microalga cultivation. C. vulgaris growth was greatly promoted with MSGW compared with the inorganic BG11 medium. C. vulgaris obtained the maximum biomass concentration (1.02 g/L) and biomass productivity (61.47 mg/Ld) with 100-time diluted MSGW. The harvested biomass was rich in protein (36.01-50.64%) and low in lipid (13.47-25.4%) and carbohydrate (8.94-20.1%). The protein nutritional quality and unsaturated fatty acids content of algal increased significantly with diluted MSGW. These results indicated that the MSGW is a feasible alternative for mass cultivation of C. vulgaris. Copyright © 2013 Elsevier Ltd. All rights reserved.

Generation and characterization of four dilutions of diesel engine exhaust for a subchronic inhalation study.

PubMed

McDonald, Jacob D; Barr, Edward B; White, Richard K; Chow, Judith C; Schauer, James J; Zielinska, Barbara; Grosjean, Eric

2004-05-01

Exposure atmospheres for a rodent inhalation toxicology study were generated from the exhaust of a 2000 Cummins ISB 5.9L diesel engine coupled to a dynamometer and operated on a slightly modified heavy-duty Federal Test Procedure cycle. Exposures were conducted to one clean air control and four diesel exhaust levels maintained at four different dilution rates (300:1, 100:1, 30:1, 10:1) that yielded particulate mass concentrations of 30, 100, 300, and 1000 microg/m3. Exposures at the four dilutions were characterized for particle mass, particle size distribution (reported elsewhere), detailed chemical speciation of gaseous, semivolatile, and particle-phase inorganic and organic compounds. Target analytes included metals, inorganic ions and gases, organic and elemental carbon, alkanes, alkenes, aromatic and aliphatic acids, aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), oxygenated PAH, nitrogenated PAH, isoprenoids, carbonyls, methoxyphenols, sugar derivatives, and sterols. The majority of the mass of material in the exposure atmospheres was gaseous nitrogen oxides and carbon monoxide, with lesser amounts of volatile organics and particle mass (PM) composed of carbon (approximately 90% of PM) and ions (approximately 10% of PM). Measured particle organic species accounted for about 10% of total organic particle mass and were mostly alkanes and aliphatic acids. Several of the components in the exposure atmosphere scaled in concentration with dilution but did not scale precisely with the dilution rate because of background from the rodents and scrubbed dilution air, interaction of animal derived emissions with diesel exhaust components, and day-to-day variability in the output of the engine. Rodent-derived ammonia reacted with exhaust to form secondary inorganic particles (at different rates dependent on dilution), and rodent respiration accounted for volatile organics (especially carbonyls and acids) in the same range as the diesel exhaust at the lowest exhaust exposure concentrations. Day-to-day variability in the engine output was implicated partially for differences of several components, including some of the particle bound organics. Though these observations have likely occurred in nearly all inhalation exposure atmospheres that contain complex mixtures of material, the speciations conducted here illustrate many of them for the first time.

Dilution correction equation revisited: The impact of stream slope, relief ratio and area size of basin on geochemical anomalies

NASA Astrophysics Data System (ADS)

Shahrestani, Shahed; Mokhtari, Ahmad Reza

2017-04-01

Stream sediment sampling is a well-known technique used to discover the geochemical anomalies in regional exploration activities. In an upstream catchment basin of stream sediment sample, the geochemical signals originating from probable mineralization could be diluted due to mixing with the weathering material coming from the non-anomalous sources. Hawkes's equation (1976) was an attempt to overcome the problem in which the area size of catchment basin was used to remove dilution from geochemical anomalies. However, the metal content of a stream sediment sample could be linked to several geomorphological, sedimentological, climatic and geological factors. The area size is not itself a comprehensive representative of dilution taking place in a catchment basin. The aim of the present study was to consider a number of geomorphological factors affecting the sediment supply, transportation processes, storage and in general, the geochemistry of stream sediments and their incorporation in the dilution correction procedure. This was organized through employing the concept of sediment yield and sediment delivery ratio and linking such characteristics to the dilution phenomenon in a catchment basin. Main stream slope (MSS), relief ratio (RR) and area size (Aa) of catchment basin were selected as the important proxies (PSDRa) for sediment delivery ratio and then entered to the Hawkes's equation. Then, Hawkes's and new equations were applied on the stream sediment dataset collected from Takhte-Soleyman district, west of Iran for Au, As and Sb values. A number of large and small gold, antimony and arsenic mineral occurrences were used to evaluate the results. Anomaly maps based on the new equations displayed improvement in anomaly delineation taking the spatial distribution of mineral deposits into account and could present new catchment basins containing known mineralization as the anomaly class, especially in the case of Au and As. Four catchment basins having Au and As mineralization were added to anomaly class and also one catchment basin with known As occurrence was highlighted as anomalous using new approach. The results demonstrated the usefulness of considering geomorphological parameters in dealing with dilution phenomenon in a catchment basin.

An in vitro comparison of the effects of voluven (6% hydroxyethyl starch 130/0.4) and hespan (6% hydroxyethyl starch 670/0.75) on measures of blood coagulation in canine blood.

PubMed

Griego-Valles, Michelle; Buriko, Yekaterina; Prittie, Jennifer E; Fox, Philip R

2017-01-01

To assess primary and secondary hemostasis following in vitro dilution of canine whole blood (WB) with hydroxyethyl starch (HES) 130/0.4 and HES 670/0.75. In vitro experimental study. Private practice, teaching hospital. Twenty-five healthy dogs. Each dog underwent venipuncture and 18 mL of venous blood was sampled once. Collected blood was separated in 4 aliquots. Aliquot A served as baseline sample. The remaining tubes of WB were diluted with 0.9% saline, HES 670/0.75 and HES 130/0.4 at a ratio of 1:5.5. Dilutional effects were evaluated using prothrombin time (PT), activated partial thromboplastin time (aPTT), packed cell volume (PCV), thromboelastography (TEG), and platelet closure time (Ct), which was measured using a platelet function analyzer (PFA). Clot strength (ie, G value) was calculated from measured TEG values. Significant increases in PT (P < 0.05) and aPTT (P < 0.05) were documented following WB dilution with saline. Dilution of WB with HES 670/0.75 and HES 130/0.4 resulted in significant hypocoagulable changes in K, MA and G (P < 0.05) compared to baseline and saline. When comparing saline to HES 670/0.75, both R and K values were significantly increased (P < 0.05). K value was significantly increased (P < 0.05) when comparing baseline to HES 130/0.4 and HES 670/0.75. Ct (P < 0.05) was significantly prolonged after WB dilution with HES solutions but not after saline. Dilution of WB with HES 670/0.75 and HES 130/0.4 resulted in changes in primary and secondary hemostasis. Although there were small differences between saline and HES 670/0.75, no differences between HES solutions were evident in this small study. This may suggest there would be minimal increases in bleeding risk when either solution is administered to dogs at low doses. Clinical relevance of our findings requires further investigation. © Veterinary Emergency and Critical Care Society 2016.

Sin Nombre Virus and Rodent Species Diversity: A Test of the Dilution and Amplification Hypotheses

PubMed Central

Clay, Christine A.; Lehmer, Erin M.; Jeor, Stephen St.; Dearing, M. Denise

2009-01-01

Background Species diversity is proposed to greatly impact the prevalence of pathogens. Two predominant hypotheses, the “Dilution Effect” and the “Amplification Effect”, predict divergent outcomes with respect to the impact of species diversity. The Dilution Effect predicts that pathogen prevalence will be negatively correlated with increased species diversity, while the Amplification Effect predicts that pathogen prevalence will be positively correlated with diversity. For many host-pathogen systems, the relationship between diversity and pathogen prevalence has not be empirically examined. Methodology/Principal Findings We tested the Dilution and Amplification Effect hypotheses by examining the prevalence of Sin Nombre virus (SNV) with respect to diversity of the nocturnal rodent community. SNV is directly transmitted primarily between deer mice (Peromyscus maniculatus). Using mark-recapture sampling in the Spring and Fall of 2003–2005, we measured SNV prevalence in deer mice at 16 landscape level sites (3.1 hectares each) that varied in rodent species diversity. We explored several mechanisms by which species diversity may affect SNV prevalence, including reduced host density, reduced host persistence, the presence of secondary reservoirs and community composition. We found a negative relationship between species diversity and SNV prevalence in deer mice, thereby supporting the Dilution Effect hypothesis. Deer mouse density and persistence were lower at sites with greater species diversity; however, only deer mouse persistence was positively correlated with SNV prevalence. Pinyon mice (P. truei) may serve as dilution agents, having a negative effect on prevalence, while kangaroo rats (Dipodomys ordii), may have a positive effect on the prevalence of SNV, perhaps through effects on deer mouse behavior. Conclusions/Significance While previous studies on host-pathogen systems have found patterns of diversity consistent with either the Dilution or Amplification Effects, the mechanisms by which species diversity influences prevalence have not been investigated. Our study indicates that changes in host persistence, coupled with interspecific interactions, are important mechanisms through which diversity may influence patterns of pathogens. Our results reveal the complexity of rodent community interactions with respect to SNV dynamics. PMID:19649283

Assessing the Accuracy of the Tracer Dilution Method with Atmospheric Dispersion Modeling

NASA Astrophysics Data System (ADS)

Taylor, D.; Delkash, M.; Chow, F. K.; Imhoff, P. T.

2015-12-01

Landfill methane emissions are difficult to estimate due to limited observations and data uncertainty. The mobile tracer dilution method is a widely used and cost-effective approach for predicting landfill methane emissions. The method uses a tracer gas released on the surface of the landfill and measures the concentrations of both methane and the tracer gas downwind. Mobile measurements are conducted with a gas analyzer mounted on a vehicle to capture transects of both gas plumes. The idea behind the method is that if the measurements are performed far enough downwind, the methane plume from the large area source of the landfill and the tracer plume from a small number of point sources will be sufficiently well-mixed to behave similarly, and the ratio between the concentrations will be a good estimate of the ratio between the two emissions rates. The mobile tracer dilution method is sensitive to different factors of the setup such as placement of the tracer release locations and distance from the landfill to the downwind measurements, which have not been thoroughly examined. In this study, numerical modeling is used as an alternative to field measurements to study the sensitivity of the tracer dilution method and provide estimates of measurement accuracy. Using topography and wind conditions for an actual landfill, a landfill emissions rate is prescribed in the model and compared against the emissions rate predicted by application of the tracer dilution method. Two different methane emissions scenarios are simulated: homogeneous emissions over the entire surface of the landfill, and heterogeneous emissions with a hot spot containing 80% of the total emissions where the daily cover area is located. Numerical modeling of the tracer dilution method is a useful tool for evaluating the method without having the expense and labor commitment of multiple field campaigns. Factors tested include number of tracers, distance between tracers, distance from landfill to transect path, and location of tracers with respect to the hot spot. Results show that location of the tracers relative to the hot spot of highest landfill emissions makes the largest difference in accuracy of the tracer dilution method.

Compatibility of an Ultraselective Microcatheter and Epirubicin Loaded 300–500-μm DC Bead in Ex Vivo Study

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

Fukuoka, Yasushi, E-mail: miyano.y.fukuoka@gmail.com; Tanaka, Toshihiro, E-mail: toshihir@bf6.so-net.ne.jp; Nishiofuku, Hideyuki, E-mail: nishiofukuhideyuki@yahoo.co.jp

PurposeThe purpose of this study is to examine whether epirubicin loaded DC Bead 300–500 μm in size can pass through a 1.8-Fr ultraselective microcatheter in ex vivo study.MethodsEpirubicin (25 mg/1 mL) loaded 100–300 and 300–500 μm DC Bead were tested. Both sizes were diluted 5, 10, and 30 times using contrast material. Ultraselective microcatheter with the outer diameter of 1.8 Fr and the inner diameter of .017 inch (431.8 μm) was used. The diluted DC Bead was injected at a speed of 1 mL/min, and the pressure was continuously measured. The microspheres’ shapes after ejection were observed by a stereomicroscope.ResultsThe maximum pressure of contrast material alone was 8.40 ± 0.21 psi.more » The maximum pressure in 5, 10, and 30 times dilution groups of 100–300 μm were 9.67 ± 1.18, 9.25 ± 0.25, and 9.71 ± 0.28 psi, respectively, whereas 21.10 ± 10.2, 10.48 ± 2.14, 10.09 ± 0.37 psi, respectively in 300–500 μm groups. The maximum pressure in 5 times dilution group of 300–500 μm was significantly higher than the other groups (P < 0.05). In 300–500 μm, 4 of 10 measurements showed high pressure over 24 psi (the maximum value was 43.5 psi) in 5 times dilution group, whereas in 10 times and 30 times dilution groups, all measurements showed less than 12 psi. No damages of microspheres were found.ConclusionsEpirubicin loaded DC Bead 300–500 μm in size can pass through a 1.8-Fr ultraselective microcatheter. To avoid high resistance due to microspheres’ aggregation, dilution more than 10 times is needed.« less

Steady-state shock-driven reactions in mixtures of nano-sized aluminum and dilute hydrogen peroxide

DOE PAGES

Schmitt, Matthew Mark; Bowden, Patrick Robert; Tappan, Bryce C.; ...

2017-09-21

Mixtures of nanoaluminum (nAl) and dilute hydrogen peroxide (HP) were studied to determine their potential to detonate when subjected to explosive shock. Results of explosively driven rate stick experiments revealed steady shock propagation for stoichiometric mixtures of nAl and 10 wt% HP. The critical diameter of this composition is estimated to be between 27.7 and 34.5 mm. Detonation velocities between 3.034 and 3.187 mm/μs were obtained, varying with charge diameter and density. Furthermore this represents the first measured shock-driven, self-sustained reaction in nAl and dilute HP mixtures.

OnabotulinumtoxinA therapy for compensatory hyperhidrosis.

PubMed

Adefusika, Jessica A; Brewer, Jerry D

2013-09-01

Compensatory hyperhidrosis due to the treatment for focal primary hyperhidrosis can be devastating and life-altering. The purpose of this paper is to discuss use of the iodine starch test and dilute botulinum toxin to decrease compensatory hyperhidrosis over large surface areas. A large area of the trunk affected by compensatory hyperhidrosis was treated with dilute botulinum toxin therapy using a starch iodine test for localization. The patient had exceptional results with his compensatory truncal sweating returning to normal and remaining stable for multiple months. Treating compensatory hyperhidrosis of large surface areas with dilute botulinum toxin therapy is effective and safe. © 2013 Wiley Periodicals, Inc.

Photosensitive adhesive bonding process of magnetooptic waveguides with Si guiding layer for optical nonreciprocal devices

NASA Astrophysics Data System (ADS)

Choowitsakunlert, Salinee; Takagiwa, Kenji; Kobashigawa, Takuya; Hosoya, Nariaki; Silapunt, Rardchawadee; Yokoi, Hideki

2018-05-01

A photosensitive adhesive bonding process for a magnetooptic waveguide for an optical isolator employing a nonreciprocal guided-radiation mode conversion is investigated at 1.55 µm. The magnetooptic waveguide is a straight rib type, and it is fabricated by bonding the Si guiding layer to a magnetic garnet. In the fabrication process, an adhesive material is diluted to obtain a certain thickness before depositing on a silicon-on-insulator (SOI) substrate. The relationship between the percent dilution ratio and the thickness of the adhesive layer is considered. The smallest gap thickness is found to be 0.66 µm at a dilution ratio of 2%.

Key Aroma Compounds in Lippia dulcis (Dushi Button).

PubMed

Schmitt, Rainer; Cappi, Michael; Pollner, Gwendola; Greger, Veronika

2018-03-14

An aroma extract dilution analysis (AEDA) applied on aroma extracts prepared from the edible flower Dushi Button ( Lippia dulcis) resulted in the detection of 34 odor-active compounds. The highest flavor dilution (FD) factors were determined for methyl 2-methylbutanoate, ethyl 2-methylbutanoate, 4-mercapto-4-methyl-2-pentanone, an unknown caramel-like compound, and vanillin. Quantitative measurements performed by application of stable isotope dilution assays (SIDA), followed by a calculation of odor activity values (OAVs), resulted in the revelation of 4-mercapto-4-methyl-2-pentanone, linalool, myrcene, ethyl 2-methylbutanoate, methyl 2-methylbutanoate, and ( Z)-3-hexenal as important contributors to the flavor of Dushi Buttons.

Photometry of icy satellites: How important is multiple scattering in diluting shadows?

NASA Technical Reports Server (NTRS)

Buratti, B.; Veverka, J.

1984-01-01

Voyager observations have shown that the photometric properties of icy satellites are influenced significantly by large-scale roughness elements on the surfaces. While recent progress was made in treating the photometric effects of macroscopic roughness, it is still the case that even the most complete models do not account for the effects of multiple scattering fully. Multiple scattering dilutes shadows caused by large-scale features, yet for any specific model it is difficult to calculate the amount of dilution as a function of albedo. Accordingly, laboratory measurements were undertaken using the Cornell Goniometer to evaluate the magnitude of the effect.

Combustion characteristics of an SI engine fueled with biogas fuel

NASA Astrophysics Data System (ADS)

Chen, Lei; Long, Wuqiang; Song, Peng

2017-04-01

An experimental research of the effect of H2 substitution and CO2 dilution on CH4 combustion has been carried out on a spark ignition engine. The results show that H2 addition could improve BMEP, thermal efficiency, CO and THC emissions. NOX emissions increased for higher low heating value (LHV) of H2 than CH4. CO2 dilution could effective reduce NOX emission of H2-CH4 combustion. Although engine performance, thermal efficiency and exhaust get unacceptable under high fuel dilution ratio (F.D.R.) conditions, it could be solved by decreasing F.D.R. and/or increasing hydrogen substitution ratio (H.S.R.).

In Vitro Activities of Gemifloxacin versus Five Quinolones and Two Macrolides against 271 Spanish Isolates of Legionella pneumophila: Influence of Charcoal on Susceptibility Test Results

PubMed Central

García, M. T.; Pelaz, C.; Giménez, M. J.; Aguilar, L.

2000-01-01

The MICs at which 90% of isolates are inhibited for gemifloxacin, trovafloxacin, and grepafloxacin were low (≤0.01 μg/ml) for 271 Legionella isolates when they were determined by the broth microdilution method but increased (≥6 dilutions) when they were determined by the agar dilution method. This was due to the charcoal in the agar dilution medium, as shown by the progressive decrease in the MICs when the charcoal concentrations decreased. As free drug is the active fraction, charcoal binding should be considered. PMID:10898695

40 CFR 1065.805 - Sampling system.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Sampling system. 1065.805 Section 1065... ENGINE-TESTING PROCEDURES Testing With Oxygenated Fuels § 1065.805 Sampling system. (a) Dilute engine exhaust, and use batch sampling to collect proportional flow-weighted dilute samples of the applicable...

40 CFR 1065.805 - Sampling system.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Sampling system. 1065.805 Section 1065... ENGINE-TESTING PROCEDURES Testing With Oxygenated Fuels § 1065.805 Sampling system. (a) Dilute engine exhaust, and use batch sampling to collect proportional flow-weighted dilute samples of the applicable...

Production of ethanol and furfural from corn stover

USDA-ARS?s Scientific Manuscript database

Corn stover has potential for economical production of biofuels and value-added chemicals. The conversion of corn stover to sugars involves pretreatment and enzymatic hydrolysis. We have optimized hydrothermal, dilute H2SO4 and dilute H3PO4 pretreatments of corn stover for enzymatic saccharificati...

Fuel ethanol production from corn stover under optimized dilute phosphoric acid pretreatment and enzymatic hydrolysis

USDA-ARS?s Scientific Manuscript database

Ethanol is a renewable oxygenated fuel. Dilute acid pretreatment is a promising pretreatment technology for conversion of lignocellulosic biomass to fuel ethanol. Generation of fermentable sugars from corn stover involves pretreatment and enzymatic saccharification. Pretreatment is crucial as nat...

19 CFR 10.206 - Value content requirement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... countries, plus the direct costs of processing operations performed in a beneficiary country or countries...)(1) of this part. Any cost or value of materials or direct costs of processing operations...) combining or packaging operations, or mere dilution with water or mere dilution with another substance that...

40 CFR 86.537-90 - Dynamometer test runs.

Code of Federal Regulations, 2014 CFR

2014-07-01

... “transient” formaldehyde exhaust sample, the “transient” dilution air sample bag, the “transient” methanol... start “transient” exhaust and dilution air bag samples to the analytical system and process the samples... Section 86.537-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 86.537-90 - Dynamometer test runs.

Code of Federal Regulations, 2012 CFR

2012-07-01

... “transient” formaldehyde exhaust sample, the “transient” dilution air sample bag, the “transient” methanol... start “transient” exhaust and dilution air bag samples to the analytical system and process the samples... Section 86.537-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 86.537-90 - Dynamometer test runs.

Code of Federal Regulations, 2013 CFR

2013-07-01

... “transient” formaldehyde exhaust sample, the “transient” dilution air sample bag, the “transient” methanol... start “transient” exhaust and dilution air bag samples to the analytical system and process the samples... Section 86.537-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

Lab tests on the biodegradation of chemically dispersed oil should consider the rapid dilution that occurs at sea.

PubMed

Lee, Kenneth; Nedwed, Tim; Prince, Roger C; Palandro, David

2013-08-15

Most crude oils spread on open water to an average thickness as low as 0.1 mm. The application of dispersants enhances the transport of oil as small droplets into the water column, and when combined with the turbulence of 1 m waves will quickly entrain oil into the top 1 m of the water column, where it rapidly dilutes to concentrations less than 100 ppm. In less than 24 h, the dispersed oil is expected to mix into the top 10 m of the water column and be diluted to concentrations well below 10 ppm, with dilution continuing as time proceeds. Over the multiple weeks that biodegradation takes place, dispersed oil concentrations are expected to be below 1 ppm. Measurements from spills and wave basin studies support these calculations. Published laboratory studies focused on the quantification of contaminant biodegradation rates have used concentrations orders of magnitude greater than this, as it was necessary to ensure the concentrations of hydrocarbons and other chemicals were higher than the detection limits of chemical analysis. However, current analytical methods can quantify individual alkanes and PAHs (and their alkyl homologues) at ppb and ppm levels. To simulate marine biodegradation of dispersed oil at dilute concentrations commonly encountered in the field, laboratory studies should be conducted at similarly low hydrocarbon concentrations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Quality- and dilution losses in the recycling of ferrous materials from end-of-life passenger cars: input-output analysis under explicit consideration of scrap quality.

PubMed

Nakamura, Shinichiro; Kondo, Yasushi; Matsubae, Kazuyo; Nakajima, Kenichi; Tasaki, Tomohiro; Nagasaka, Tetsuya

2012-09-04

Metals can in theory be infinitely recycled in a closed-loop without any degradation in quality. In reality, however, open-loop recycling is more typical for metal scrap recovered from end-of-life (EoL) products because mixing of different metal species results in scrap quality that no longer matches the originals. Further losses occur when meeting the quality requirement of the target product requires dilution of the secondary material by adding high purity materials. Standard LCA usually does not address these losses. This paper presents a novel approach to quantifying quality- and dilution losses, by means of hybrid input-output analysis. We focus on the losses associated with the recycling of ferrous materials from end-of-life vehicle (ELV) due to the mixing of copper, a typical contaminant in steel recycling. Given the quality of scrap in terms of copper density, the model determines the ratio by which scrap needs to be diluted in an electric arc furnace (EAF), and the amount of demand for EAF steel including those quantities needed for dilution. Application to a high-resolution Japanese IO table supplemented with data on ferrous materials including different grades of scrap indicates that a nationwide avoidance of these losses could result in a significant reduction of CO(2) emissions.

Multi-laboratory survey of qPCR enterococci analysis method performance

EPA Pesticide Factsheets

Quantitative polymerase chain reaction (qPCR) has become a frequently used technique for quantifying enterococci in recreational surface waters, but there are several methodological options. Here we evaluated how three method permutations, type of mastermix, sample extract dilution and use of controls in results calculation, affect method reliability among multiple laboratories with respect to sample interference. Multiple samples from each of 22 sites representing an array of habitat types were analyzed using EPA Method 1611 and 1609 reagents with full strength and five-fold diluted extracts. The presence of interference was assessed three ways: using sample processing and PCR amplifications controls; consistency of results across extract dilutions; and relative recovery of target genes from spiked enterococci in water sample compared to control matrices with acceptable recovery defined as 50 to 200%. Method 1609, which is based on an environmental mastermix, was found to be superior to Method 1611, which is based on a universal mastermix. Method 1611 had over a 40% control assay failure rate with undiluted extracts and a 6% failure rate with diluted extracts. Method 1609 failed in only 11% and 3% of undiluted and diluted extracts analyses. Use of sample processing control assay results in the delta-delta Ct method for calculating relative target gene recoveries increased the number of acceptable recovery results. Delta-delta tended to bias recoveries fr

Simplified Method for Groundwater Treatment Using Dilution and Ceramic Filter

NASA Astrophysics Data System (ADS)

Musa, S.; Ariff, N. A.; Kadir, M. N. Abdul; Denan, F.

2016-07-01

Groundwater is one of the natural resources that is not susceptible to pollutants. However, increasing activities of municipal, industrial, agricultural or extreme land use activities have resulted in groundwater contamination as occured at the Research Centre for Soft Soil Malaysia (RECESS), Universiti Tun Hussein Onn Malaysia (UTHM). Thus, aims of this study is to treat groundwater by using rainwater and simple ceramic filter as a treatment agent. The treatment uses rain water dilution, ceramic filters and combined method of dilute and filtering as an alternate treatment which are simple and more practical compared to modern or chemical methods. The water went through dilution treatment processes able to get rid of 57% reduction compared to initial condition. Meanwhile, the water that passes through the filtering process successfully get rid of as much as 86% groundwater parameters where only chloride does not pass the standard. Favorable results for the combination methods of dilution and filtration methods that can succesfully eliminate 100% parameters that donot pass the standards of the Ministry of Health and the Interim National Drinking Water Quality Standard such as those found in groundwater in RECESS, UTHM especially sulfate and chloride. As a result, it allows the raw water that will use clean drinking water and safe. It also proves that the method used in this study is very effective in improving the quality of groundwater.

Measurement of LNAPL flow using single-well tracer dilution techniques.

PubMed

Sale, Tom; Taylor, Geoffrey Ryan; Iltis, Gabriel; Lyverse, Mark

2007-01-01

This paper describes the use of single-well tracer dilution techniques to resolve the rate of light nonaqueous phase liquid (LNAPL) flow through wells and the adjacent geologic formation. Laboratory studies are presented in which a fluorescing tracer is added to LNAPL in wells. An in-well mixer keeps the tracer well mixed in the LNAPL. Tracer concentrations in LNAPL are measured through time using a fiber optic cable and a spectrometer. Results indicate that the rate of tracer depletion is proportional to the rate of LNAPL flow through the well and the adjacent formation. Tracer dilution methods are demonstrated for vertically averaged LNAPL Darcy velocities of 0.00048 to 0.11 m/d and LNAPL thicknesses of 9 to 24 cm. Over the range of conditions studied, results agree closely with steady-state LNAPL flow rates imposed by pumping. A key parameter for estimating LNAPL flow rates in the formation is the flow convergence factor alpha. Measured convergence factors for 0.030-inch wire wrap, 0.030-inch-slotted polyvinyl chloride (PVC), and 0.010-inch-slotted PVC are 1.7, 0.91, and 0.79, respectively. In addition, methods for using tracer dilution data to determine formation transmissivity to LNAPL are presented. Results suggest that single-well tracer dilution techniques are a viable approach for measuring in situ LNAPL flow and formation transmissivity to LNAPL.

The Effects of Urbanization and Flood Control on Sediment Discharge of a Southern California River, Evidence of a Dilution Effect

NASA Astrophysics Data System (ADS)

Warrick, J. A.; Orzech, K. M.; Rubin, D. M.

2004-12-01

The southern California landscape has undergone dramatic urbanization and population growth during the past 60 years and currently supports almost 20 million inhabitants. During this time, rivers of the region have been altered with damming, channel straightening and hardening, and water transfer engineering. These changes have drastically altered water and sediment discharge from most of the region's drainage basins. Here we focus on changes in sediment discharge from the largest watershed of southern California, the Santa Ana River. Order-of-magnitude drops in the suspended sediment rating curves (the relationship between suspended sediment concentration and instantaneous river discharge) are observed between 1967 and 2001, long after the construction of a major flood control dam in 1941. These sediment concentration decreases do not, however, represent alteration of the total sediment flux from the basin (a common interpretation of sediment rating curves), but rather a dilution of suspended sediment by increases (approx. 4x) in stormwater discharge associated with urbanization. Increases in peak and total stormwater discharge are consistent with runoff patterns from urbanizing landscapes, supporting our hypothesis that the diluting water originated from stormwater runoff generated in urban areas both up- and downstream of dams. Our dilution hypothesis is further supported with water and sediment budgets, dilution calculations, and suspended and bed grain size information.

Animal models for studying homeopathy and high dilutions: conceptual critical review.

PubMed

Bonamin, Leoni Villano; Endler, Peter Christian

2010-01-01

This is a systematic review of the animal models used in studies of high dilutions. The objectives are to analyze methodological quality of papers and reported results, and to highlight key conceptual aspects of high dilution to suggest clues concerning putative mechanisms of action. Papers for inclusion were identified systematically, from the Pubmed-Medline database, using 'Homeopathy' and 'Animal' as keywords. Only original full papers in English published between January 1999 and June 2009 were included, reviews, scientific reports, thesis, older papers, papers extracted from Medline using similar keywords, papers about mixed commercial formulas and books were also considered for discussion only. 31 papers describing 33 experiments were identified for the main analysis and a total of 89 items cited. Systematic analysis of the selected papers yielded evidence of some important intrinsic features of high dilution studies performed in animal models: a) methodological quality was generally adequate, some aspects could be improved; b) convergence between results and materia medica is seen in some studies, pointing toward to the possibility of systematic study of the Similia principle c) both isopathic and Similia models seem useful to understand some complex biological phenomena, such as parasite-host interactions; d) the effects of high dilutions seem to stimulate restoration of a 'stable state', as seen in several experimental models from both descriptive and mathematical points of view. Copyright 2009 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

The effectiveness of processed grapefruit-seed extract as an antibacterial agent: II. Mechanism of action and in vitro toxicity.

PubMed

Heggers, John P; Cottingham, John; Gusman, Jean; Reagor, Lee; McCoy, Lana; Carino, Edith; Cox, Robert; Zhao, Jian-Gang; Reagor, Lana

2002-06-01

Recent testimonials report grapefruit-seed extract, or GSE (Citricidal) to be effective against more than 800 bacterial and viral strains, 100 strains of fungus, and a large number of single and multicelled parasites. This study investigated GSE for antibacterial activity at varying time intervals and concentration levels and tissue toxicity at varying concentrations in an effort to determine if a concentration existed that was both microbicidal and nontoxic and in what period of time. Gram-negative and gram-positive isolates were introduced into graduated dilutions of GSE (twofold concentrations ranging from 1:1, through 1:512) for determination of bacterial activity. In vitro assays with human skin fibroblast cells were also performed at the same dilutions to determine toxicity. These tests indicated that from the 1:1 through the 1:128 concentrations, GSE remained toxic as well as bactericidal. However, test results indicated that at the 1:512 dilution, GSE remained bactericidal, but completely nontoxic. The initial data shows GSE to have antimicrobial properties against a wide range of gram-negative and gram-positive organisms at dilutions found to be safe. With the aid of scanning transmission electron microscopy (STEM), the mechanism of GSE's antibacterial activity was revealed. It was evident that GSE disrupts the bacterial membrane and liberates the cytoplasmic contents within 15 minutes after contact even at more dilute concentrations.

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

Beavin, P. Jr.

A previously published method for determining zirconium in antiperspirant aerosols was collaboratively studied by 7 laboratories. The method consists of 2 procedures: a rapid dilution procedure for soluble zirconium compounds or a lengthier fusion procedure for total zirconium followed by colorimetric determination. The collaborators were asked to perform the following: Spiking materials representing 4 levels of soluble zirconium were added to weighed portions of a zirconium-free cream base concentrate and the portions were assayed by the dilution procedure. Spiking materials representing 4 levels of zirconium in either the soluble or the insoluble form (or as a mixture) were also addedmore » to portions of the same concentrate and these portions were assayed by the fusion procedure. They were also asked to concentrate and assay, by both procedures, 2 cans each of 2 commercial aerosol antiperspirants containing zirconyl hydroxychloride. The average percent recoveries and standard deviations for spiked samples were 99.8-100.2 and 1.69-2.71, respectively, for soluble compounds determined by the dilution procedure, and 93.8-97.4 and 3.09-4.78, respectively, for soluble and/or insoluble compounds determined by the fusion procedure. The average perent zirconium found by the dilution procedure in the 2 commercial aerosol products was 0.751 and 0.792. Insufficient collaborative results were received for the fusion procedure for statistical evaluation. The dilution procedure has been adopted as official first action.« less

Probe colorimeter for quantitating enzyme-linked immunosorbent assays and other colorimetric assays performed with microplates.

PubMed Central

Ackerman, S B; Kelley, E A

1983-01-01

The performance of a fiberoptic probe colorimeter (model PC800; Brinkmann Instruments, Inc., Westbury, N.Y.) for quantitating enzymatic or colorimetric assays in 96-well microtiter plates was compared with the performances of a spectrophotometer (model 240; Gilford Instrument Laboratories, Inc., Oberlin, Ohio) and a commercially available enzyme immunoassay reader (model MR590; Dynatech Laboratories, Inc., Alexandria, Va.). Alkaline phosphatase-p-nitrophenyl phosphate in 3 M NaOH was used as the chromophore source. Six types of plates were evaluated for use with the probe colorimeter; they generated reproducibility values (100% coefficient of variation) ranging from 91 to 98% when one individual made 24 independent measurements on the same dilution of chromophore on each plate. Eleven individuals each performed 24 measurements with the colorimeter on either a visually light (absorbance of 0.10 at 420 nm) or a dark (absorbance of 0.80 at 420 nm) dilution of chromophore; reproducibilities averaged 87% for the light dilution and 97% for the dark dilution. When one individual measured the same chromophore sample at least 20 times in the colorimeter, in the spectrophotometer or in the enzyme immunoassay reader, reproducibility for each instrument was greater than 99%. Measurements of a dilution series of chromophore in a fixed volume indicated that the optical responses of each instrument were linear in a range of 0.05 to 1.10 absorbance units. Images PMID:6341399

Probe colorimeter for quantitating enzyme-linked immunosorbent assays and other colorimetric assays performed with microplates.

PubMed

Ackerman, S B; Kelley, E A

1983-03-01

The performance of a fiberoptic probe colorimeter (model PC800; Brinkmann Instruments, Inc., Westbury, N.Y.) for quantitating enzymatic or colorimetric assays in 96-well microtiter plates was compared with the performances of a spectrophotometer (model 240; Gilford Instrument Laboratories, Inc., Oberlin, Ohio) and a commercially available enzyme immunoassay reader (model MR590; Dynatech Laboratories, Inc., Alexandria, Va.). Alkaline phosphatase-p-nitrophenyl phosphate in 3 M NaOH was used as the chromophore source. Six types of plates were evaluated for use with the probe colorimeter; they generated reproducibility values (100% coefficient of variation) ranging from 91 to 98% when one individual made 24 independent measurements on the same dilution of chromophore on each plate. Eleven individuals each performed 24 measurements with the colorimeter on either a visually light (absorbance of 0.10 at 420 nm) or a dark (absorbance of 0.80 at 420 nm) dilution of chromophore; reproducibilities averaged 87% for the light dilution and 97% for the dark dilution. When one individual measured the same chromophore sample at least 20 times in the colorimeter, in the spectrophotometer or in the enzyme immunoassay reader, reproducibility for each instrument was greater than 99%. Measurements of a dilution series of chromophore in a fixed volume indicated that the optical responses of each instrument were linear in a range of 0.05 to 1.10 absorbance units.

Development of reproducible assays for polygalacturonase and pectinase.

PubMed

Li, Qian; Coffman, Anthony M; Ju, Lu-Kwang

2015-05-01

Polygalacturonase and pectinase activities reported in the literature were measured by several different procedures. These procedures do not give comparable results, partly owing to the complexity of the substrates involved. This work was aimed at developing consistent and efficient assays for polygalacturonase and pectinase activities, using polygalacturonic acid and citrus pectin, respectively, as the substrate. Different enzyme mixtures produced by Aspergillus niger and Trichoderma reesei with different inducing carbon sources were used for the method development. A series of experiments were conducted to evaluate the incubation time, substrate concentration, and enzyme dilution. Accordingly, for both assays the recommended (optimal) hydrolysis time is 30min and substrate concentration is 5g/L. For polygalacturonase, the sample should be adjusted to have 0.3-0.8U/mL polygalacturonase activity, because in this range the assay outcomes were consistent (independent of dilution factors). Such a range did not exist for the pectinase assay. The recommended procedure is to assay the sample at multiple (at least 2) dilution factors and determine, by linear interpolation, the dilution factor that would release reducing sugar equivalent to 0.4g/L d-galacturonic acid, and then calculate the activity of the sample accordingly (dilution factor×0.687U/mL). Validation experiments showed consistent results using these assays. Effects of substrate preparation methods were also examined. Copyright © 2015 Elsevier Inc. All rights reserved.

Bactericidal activity of lemon juice and lemon derivatives against Vibrio cholerae.

PubMed

de Castillo, M C; de Allori, C G; de Gutierrez, R C; de Saab, O A; de Fernandez, N P; de Ruiz, C S; Holgado, A P; de Nader, O M

2000-10-01

Food products can be possible vectors of the agent responsible for cholera epidemics, because some of these products allow Vibrio cholerae O1 to develop to concentrations above the dangerous level. This study deals with the behaviour of essential oils, natural and concentrated lemon juice and fresh and dehydrated lemon peel against V. cholerae O1 biotype Eltor serotype Inaba tox+. Our aim was to evaluate whether these products, used at different dilutions, exhibit bactericidal or bacteriostatic activity against the microorganism, when present at concentrations of 10(2), 10(4), 10(6) and 10(8) colony forming units (CFU) ml(-1), and after different exposure times. 10(8) CFU ml(-1) was considered an infectious dose. Concentrated lemon juice and essential oils inhibited V. cholerae completely at all studied dilutions and exposure times. Fresh lemon peel and dehydrated lemon peel partially inhibited growth of V. cholerae. Freshly squeezed lemon juice, diluted to 10(-2), showed complete inhibition of V. cholerae at a concentration of 10(8) CFU ml(-1) after 5 min of exposure time; a dilution of 2 x 10(-3) produced inhibition after 15 min and a dilution of 10(-3) after 30 min. It can be concluded that lemon, a natural product which is easily obtained, acts as a biocide against V. cholerae, and is, therefore, an efficient decontaminant, harmless to humans.

Effect of the dilution rate on microbial competition: r-strategist can win over k-strategist at low substrate concentration.

PubMed

Winkler, Mari-K H; Boets, Pieter; Hahne, Birk; Goethals, Peter; Volcke, Eveline I P

2017-01-01

The conditions present in both in vitro and in vivo ecosystems determine the microbial population harbouring it. One commonly accepted theory is that a species with a high substrate affinity and low growth rate (k-strategist) will win the competition against a second species with a lower substrate affinity and higher growth rate (r-strategist) if both species are subjected to low substrate concentrations. In this study two nitrite oxidizing bacteria (NOB), Nitrospira defluvii (k-strategist) and Nitrobacter vulgaris (r-strategist), were cultivated in a continuous reactor systems. The minimal hydraulic retention time (HRT) required for maintaining the slower growing Nitrospira was first determined. A reactor containing Nitrobacter was set to the same HRT and Nitrospira was injected to evaluate the effect of the dilution rate on the competition between both species. By following the microbial population dynamics with qPCR analysis, it was shown that not only the substrate affinity drives the competition between k- and r-strategists but also the dilution rate. Experimental data and numerical simulations both revealed that the washout of Nitrobacter was significantly delayed at dilution rates close to the μmax of Nitrospira. The competition could be even reverted towards Nitrobacter (r-strategist) despite of low nitrite concentrations and dilution rates lower than the μmax of Nitrospira.

Determination of 232Th in urine by ICP-MS for individual monitoring purposes.

PubMed

Baglan, N; Cossonnet, C; Ritt, J

2001-07-01

Thorium is naturally occurring in various ores used for industrial purposes and has numerous applications. This paper sets out to investigate urine analysis as a suitable monitoring approach for workers potentially exposed to thorium. Due to its biokinetic behavior and its low solubility, urinary concentrations are generally very low, requiring therefore high sensitivity analytical methods. An analytical procedure has been developed for detecting 232Th concentrations of below 1 mBq L(-1) quickly and easily. Due to the long half-life (1.41 x 10(10) y) of 232Th, the potential of a procedure based on urine sample dilution and ICP-MS (inductively coupled plasma-mass spectrometry) measurement was investigated first. Two dilution factors were chosen: 100, which is more suitable for long-term measurement trials, and 20, which increases sensitivity. It has been shown that a 100-fold dilution can be used to measure concentrations of below 1 mBq L(-1), whereas a 20-fold one can be used to reach concentrations of below 0.06 mBq L(-1). Then, on the basis of the limitation of the procedure based on urine dilution, the suitable field of application for the different procedures (100-fold and 20-fold dilution and also a chemical purification followed by an ICP-MS measurement) was determined in relation to monitoring objectives.

Effectiveness of qPCR permutations, internal controls and dilution as means for minimizing the impact of inhibition while measuring Enterococcus in environmental waters.

PubMed

Cao, Y; Griffith, J F; Dorevitch, S; Weisberg, S B

2012-07-01

  Draft criteria for the optional use of qPCR for recreational water quality monitoring have been published in the United States. One concern is that inhibition of the qPCR assay can lead to false-negative results and potentially inadequate public health protection. We evaluate the effectiveness of strategies for minimizing the impact of inhibition.   Five qPCR method permutations for measuring Enterococcus were challenged with 133 potentially inhibitory fresh and marine water samples. Serial dilutions were conducted to assess Enterococcus target assay inhibition, to which inhibition identified using four internal controls (IC) was compared. The frequency and magnitude of inhibition varied considerably among qPCR methods, with the permutation using an environmental master mix performing substantially better. Fivefold dilution was also effective at reducing inhibition in most samples (>78%). ICs were variable and somewhat ineffective, with 54-85% agreement between ICs and serial dilution.   The current IC methods appear to not accurately predict Enterococcus inhibition and should be used with caution; fivefold dilution and the use of reagents designed for environmental sample analysis (i.e. more robust qPCR chemistry) may be preferable.   Suitable approaches for defining, detecting and reducing inhibition will improve implementation of qPCR for water monitoring. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Effect of Melanin Free Ink Extracted From Squid (Loligo sp.) on Proximate and Sensory Characteristics of Soft-Bone Milkfish (Chanos chanos) During Storage

NASA Astrophysics Data System (ADS)

Winarni Agustini, Tri; Hadiyanto; Wijayanti, Ima; Amalia, Ulfah; Benjakul, Soottawat

2018-02-01

Antioxidant could be extracted and isolated from squid inks. Squid ink in the form of melanin free ink (MFI) could be act as an electron donor which can stabilize free radicals in lipid oxidation. This study was carried out to assess the antioxidant activity of squid inks converted into MFI in different dilution and to optimize the extraction conditions for the application of MFI as an antioxidative agent on fish product. Three different types of MFI extracts i.e : pure squid ink, squid ink with 5 times dilution and squid ink with 10 times dilutions by using cooled ionized water (4°C). The ink was then centrifuged at 18.000 x g for 30 minutes at cooled centrifuge (4°C) followed by DPPH analysis. The results showed that the IC50 of MFI extracts were 2.84 ppm; 1.11 ppm and 0.34 ppm, respectively (p < 0.05). The results indicated that squid ink with 10 times dilution in extraction of MFI had the highest value in free radical inhibitory. Although the IC50 of three different dilutions are equally low, and are considered as very strong antioxidative agent, however, it showed that the MFI extracted from squid ink had the ability to prevent free radical

Improved quantification of a commercial enzyme-linked immunosorbent assay kit for measuring anti-MDA5 antibody.

PubMed

Gono, Takahisa; Okazaki, Yuka; Murakami, Akihiro; Kuwana, Masataka

2018-04-09

To compare the quantitative performance for measuring anti-MDA5 antibody titer of two enzyme-linked immunosorbent assay (ELISA) systems: an in-house ELISA and the commercial MESACUP TM anti-MDA5 test. Anti-MDA5 antibody titer was measured in sera from 70 patients with dermatomyositis using an in-house ELISA and the MESACUP TM anti-MDA5 test side-by-side. For the commercial ELISA kit, serum samples diluted 1:101 were used according to the manufacturer's protocol, but serial dilutions of sera were also examined to identify the optimal serum dilution for quantification. The anti-MDA5 antibody titers measured by the in-house and commercial ELISAs were positively correlated with each other (r = 0.53, p = .0001), but the antibody titer measured by the commercial ELISA was less sensitive to change after medical treatment, and 37 (80%) of 46 anti-MDA5-positive sera had antibody titer exceeding the quantification range specified by the manufacturer (≥150 index). Experiments using diluted serum samples revealed that diluting the sera 1:5050 improved the quantitative performance of the MESACUP TM anti-MDA5 test, including a better correlation with the in-house ELISA results and an increased sensitivity to change. We improved the ability of the commercial ELISA kit to quantify anti-MDA5 antibody titer by altering its protocol.

Mitigation of ammonia inhibition by internal dilution in high-rate anaerobic digestion of food waste leachate and evidences of microbial community response.

PubMed

Yun, Yeo-Myeong; Kim, Dong-Hoon; Cho, Si-Kyung; Shin, Hang-Sik; Jung, Kyung-Won; Kim, Hyun-Woo

2016-09-01

A high-rate anaerobic digestion of food waste leachate were tested using intermittent continuously stirred tank reactors (iCSTRs) to evaluate how severe ammonia inhibition could be mitigated with internal dilution strategy, and to identify how bacterial and archaeal community respond in genus and species level. Experimental results show that the digestion performance was well maintained up to hydraulic retention time (HRT) of 40 days but could not keep steady-state as HRT decreased to 30 days due to severe free ammonia (FA) inhibition. Coupling internal dilution was the key to relieve the inhibition since it reduced FA concentration as low as 62 mg/L even at HRT 30 days, which corresponds to organic loading rate of 5 g COD/L/d, demonstrating CH4 yield of 0.32 L CH4 /g CODadded . It was confirmed that the dilution offers iCTSRs manage severe ammonia inhibition with the balanced community structure between bacteria and archaea in this high-rate anaerobic digestion. Genus and species level pyrosequencing evidence that FA inhibition to community dynamics of Methanosarcina and Methanosaeta is strongly connected to methanogenesis, and Methanosarcina plays a key role in an iCSTR with the dilution. Biotechnol. Bioeng. 2016;113: 1892-1901. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Reactivity of Pleistocene aged organic matter in the Siberian Arctic

NASA Astrophysics Data System (ADS)

Davydov, S.; Vonk, J. E.; Mann, P. J.; Davydova, A.; Sobczak, W. V.; Schade, J. D.; Bulygina, E. B.; Zimov, S. A.; Holmes, R. M.

2011-12-01

Half of the global stock of soil organic carbon (OC) is stored in Arctic permafrost. About one third of this pool consists of so-called yedoma, organic-rich deposits that were formed during the Pleistocene. Previous studies show rapid respiration of yedoma upon thawing, with the potential release of large quantities of relict OC into the contemporary C cycle. The fluvial and coastal reactivity of this OC, however, and its fate remain unclear. Duvannyi Yar is a well-studied yedoma exposure on the banks of Kolyma River in Northeastern Siberia. It can serve as a model for the >7000 km long East Siberian Arctic coastline that is dominated by similarly exposed yedoma cliffs, and is increasingly vulnerable to erosion with climate warming-induced decreases in sea-ice, and increases in storms and wave-fetch. Permafrost thaw causes the slopes of Duvannyi Yar to retreat 3-5 m/y, producing mudstreams that drain into the Kolyma River. These streams are heavily loaded with freshly thawed yedoma sediments (ca. 650 g/L; POC ca. 10 g/L; DOC ca. 150 mg/L). Partial CO2 pressure in these streams was on average 8400 ppm (stdev 2100; n=4) whereas the Kolyma River at the stream mouth contained CO2 concentrations of ca. 900 ppm (stdev 90; n=4), suggesting substantial outgassing during transport. We performed biological oxygen demand assays in combination with a set of incubations to estimate OC lability in a range of dilutions of Duvannyi Yar water with Kolyma River and East Siberian Sea water, in combination with nutrient and enzymatic activity rate analysis to identify potential limitation processes. Our goal was to assess carbon consumption rates and the effect of different microbial communities along its transport towards the ocean. O2 loss (% after 24h) increased significantly from undiluted Kolyma water to increasingly spiked dilutions with filtered Duvannyi Yar filtered water; 0%/0.5%/1%/10%/100% dilutions showed O2 losses of 1.6%, 3.5%, 5.1%, 13% and 35%, respectively. However, C-normalized O2 losses demonstrated a different pattern. After a 24h C-loss of 5-7% for all three dilutions, the 10% dilution continued to respond up to a total of 33% lost carbon after 5 days. Enzymatic activity rates of the lignin-degrading enzyme phenoloxidase corroborated this by showing strongly elevated activity rates for the 10% Duvannyi Yar-Kolyma dilution, opposite to the 1% or 0.5% dilutions or Kolyma background. Dilutions with Kolyma water showed a slightly but consistently higher processing rate compared to dilutions of East Siberian Sea water (26 salinity). These results suggest that old OC is biologically labile upon fluvial release and its breakdown appears to be limited by availability of organic substrates. Furthermore, it appears that refractory carbon in the Kolyma is in fact being processed faster when enough Duvannyi Yar water, along with its microbes and enzymes, is added.

40 CFR 180.1196 - Peroxyacetic acid; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD... antimicrobial treatment in solutions containing a diluted end use concentration of peroxyacetic acid up to 100... food commodities when used in sanitizing solutions containing a diluted end-use concentration of...

Xylanase supplementation on enzymatic saccharification of dilute acid pretreated poplars at different severities

Treesearch

Chao Zhang; Xinshu Zhuang; Zhao Jiang Wang; Fred Matt; Franz St. John; J.Y. Zhu

2013-01-01

Three pairs of solid substrates from dilute acid pretreatment of two poplar wood samples were enzymatically hydrolyzed by cellulase preparations supplemented with xylanase. Supplementation of xylanase improved cellulose saccharification perhaps due to improved cellulose accessibility by xylan hydrolysis. Total xylan removal directly affected enzymatic cellulose...

Comparison of Dilute Acid and Ionic Liquid Pretreatment of Switchgrass: Biomass Recalcitrance, Delignification and Enzymatic Saccharification

USDA-ARS?s Scientific Manuscript database

The efficiency of two biomass pretreatment technologies, dilute acid hydrolysis and dissolution in an ionic liquid, are compared in terms of delignification, saccharification efficiency and saccharide yields with switchgrass serving as a model bioenergy crop. When subject to ionic liquid pretreatme...

40 CFR 86.605-88 - Maintenance of records; submittal of information.

Code of Federal Regulations, 2014 CFR

2014-07-01

... of the mixture of exhaust and dilution air entering the positive displacement pump, pressure increase... being collected. (3) Humidity of dilution air. (4) Manufacturer, model, type and serial number. (C... temperature and humidity. (2) Data and time of day. (ii) In lieu of recording test equipment information...

An Isotopic Dilution Experiment Using Liquid Scintillation: A Simple Two-System, Two-Phase Analysis.

ERIC Educational Resources Information Center

Moehs, Peter J.; Levine, Samuel

1982-01-01

A simple isotonic, dilution analysis whose principles apply to methods of more complex radioanalyses is described. Suitable for clinical and instrumental analysis chemistry students, experimental manipulations are kept to a minimum involving only aqueous extraction before counting. Background information, procedures, and results are discussed.…

21 CFR 172.710 - Adjuvants for pesticide use dilutions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Adjuvants for pesticide use dilutions. 172.710 Section 172.710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Other Specific Usage...

21 CFR 866.2500 - Microtiter diluting and dispensing device.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microtiter diluting and dispensing device. 866.2500 Section 866.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2500...

21 CFR 866.2500 - Microtiter diluting and dispensing device.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Microtiter diluting and dispensing device. 866.2500 Section 866.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2500...

21 CFR 866.2500 - Microtiter diluting and dispensing device.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Microtiter diluting and dispensing device. 866.2500 Section 866.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2500...

21 CFR 866.2500 - Microtiter diluting and dispensing device.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Microtiter diluting and dispensing device. 866.2500 Section 866.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2500...

21 CFR 866.2500 - Microtiter diluting and dispensing device.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Microtiter diluting and dispensing device. 866.2500 Section 866.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2500...

Implementing Inquiry-Based Learning in Teaching Serial Dilutions

ERIC Educational Resources Information Center

Walker, Candace L.; McGill, Michael T.; Buikema, Arthur L., Jr.; Stevens, Ann M.

2008-01-01

The 5E model of inquiry-based learning was incorporated into a sophomore-level microbiology laboratory to increase student understanding of serial dilutions, a concept that is often difficult for most students to comprehend. Quantitative and qualitative assessments were conducted during the semester to determine the value of this approach for…

WET OXIDATION OF MUNICIPAL SLUDGE BY THE VERTICAL TUBE REACTOR

EPA Science Inventory

A study was undertaken to assess the feasibility of carrying out oxidation of dilute sewage sludge by means of the vertical tube reactor (VTR) system. A pilot scale facility along with a laboratory reactor were used for this study. Dilute sewage sludge was oxidized in the laborat...

40 CFR 148.3 - Dilution prohibited as a substitute for treatment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for treatment. 148.3 Section 148.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) HAZARDOUS WASTE INJECTION RESTRICTIONS General § 148.3 Dilution prohibited as a substitute for treatment. The prohibition of § 268.3 shall apply to owners or operators of...

40 CFR 148.3 - Dilution prohibited as a substitute for treatment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... for treatment. 148.3 Section 148.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) HAZARDOUS WASTE INJECTION RESTRICTIONS General § 148.3 Dilution prohibited as a substitute for treatment. The prohibition of § 268.3 shall apply to owners or operators of...

Color dilution alopecia in a blue Doberman pinscher crossbreed

PubMed Central

Perego, Roberta; Proverbio, Daniela; Roccabianca, Paola; Spada, Eva

2009-01-01

A 6-year-old male, blue Doberman pinscher crossbreed was presented with coat abnormalities; in particular, flank alopecia and pruritus. Based on medical the history, clinical evidence, and histopathological examination, color dilution alopecia was diagnosed. The dog was with oral melatonin treated for 3 months without success. PMID:19436637

Color dilution alopecia in a blue Doberman pinscher crossbreed.

PubMed

Perego, Roberta; Proverbio, Daniela; Roccabianca, Paola; Spada, Eva

2009-05-01

A 6-year-old male, blue Doberman pinscher crossbreed was presented with coat abnormalities; in particular, flank alopecia and pruritus. Based on medical the history, clinical evidence, and histopathological examination, color dilution alopecia was diagnosed. The dog was with oral melatonin treated for 3 months without success.

Chemical Disposal for a High School Chemistry Laboratory

ERIC Educational Resources Information Center

Mento, Mary Ann

1973-01-01

A method of disposal is suggested that is superior to the dilution method. The proceudres are based on the conversion of the wastes to less toxic or harmless forms or neutralization, so that they won't be a shock to the sewage system, and then excess dilution. (Author/DF)

Sulfuric Acid and Water: Paradoxes of Dilution

ERIC Educational Resources Information Center

Leenson, I. A.

2004-01-01

On equilibrium properties of aqueous solutions of sulfuric acid, Julius Thomsen has marked that the heat evolved on diluting liquid sulfuric acid with water is a continuous function of the water used, and excluded absolutely the acceptance of definite hydrates as existing in the solution. Information about thermochemical measurement, a discussion…

Process for producing 8-fluoropurines

DOEpatents

Barrio, J.R.; Satyamurthy, N.; Namavari, M.; Phelps, M.E.

1999-01-19

An efficient, regio-controlled approach to the synthesis of 8-fluoropurines by direct fluorination of purines with dilute elemental fluorine, or acetyl hypofluorite, is provided. In a preferred embodiment, a purine compound is dissolved in a polar solvent and reacted with a dilute mixture of F{sub 2} in He or other inert gas.

40 CFR 268.3 - Dilution prohibited as a substitute for treatment.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) The waste consists of organic, debris-like materials (e.g., wood, paper, plastic, or cloth... (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS General § 268.3 Dilution prohibited as a... restricted waste or the residual from treatment of a restricted waste as a substitute for adequate treatment...

40 CFR 268.3 - Dilution prohibited as a substitute for treatment.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) The waste consists of organic, debris-like materials (e.g., wood, paper, plastic, or cloth... (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS General § 268.3 Dilution prohibited as a... restricted waste or the residual from treatment of a restricted waste as a substitute for adequate treatment...

21 CFR 862.2750 - Pipetting and diluting system for clinical use.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pipetting and diluting system for clinical use. 862.2750 Section 862.2750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory...

21 CFR 862.2750 - Pipetting and diluting system for clinical use.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pipetting and diluting system for clinical use. 862.2750 Section 862.2750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory...

21 CFR 862.2750 - Pipetting and diluting system for clinical use.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pipetting and diluting system for clinical use. 862.2750 Section 862.2750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory...

21 CFR 862.2750 - Pipetting and diluting system for clinical use.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pipetting and diluting system for clinical use. 862.2750 Section 862.2750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory...

40 CFR 86.537-90 - Dynamometer test runs.

Code of Federal Regulations, 2010 CFR

2010-07-01

... phase of the test. Obtain methanol and formaldehyde sample analyses, if applicable, within 24 hours of... minutes of the end of the sample collection phase of the test. Obtain methanol and formaldehyde sample... the dilute exhaust and dilution air sample collection systems. (4) For methanol-fueled vehicles, with...

40 CFR 86.537-90 - Dynamometer test runs.

Code of Federal Regulations, 2011 CFR

2011-07-01

... phase of the test. Obtain methanol and formaldehyde sample analyses, if applicable, within 24 hours of... minutes of the end of the sample collection phase of the test. Obtain methanol and formaldehyde sample... the dilute exhaust and dilution air sample collection systems. (4) For methanol-fueled vehicles, with...

Policy Statement: Clarification of the Dilution Prohibition and Combustion of Inorganic Metal-Bearing Hazardous Wastes for Land Disposal Restrictions

EPA Pesticide Factsheets

This memorandum sets out a Statement of Policy under the RCRA clarifying the application of the Land Disposal Restrictions (LDR) prohibition on dilution (see 40 CFR 268.3) to combustion of certain inorganic metal-bearing hazardous wastes.

Growth kinetics of Bacillus stearothermophilus BR219

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

Worden, R.M.; Subramanian, R.; Bly, M.J.

1991-12-31

Bacillus stearothermophilus BR219, a phenol-resistant thermophile, can convert phenol to the specialty chemical catechol. The growth kinetics of this organism were studied in batch, continuous, and immobilized-cell culture. Batch growth was insensitive to pH between 6.0 and 8.0, but little growth occurred at 5.5. In continuous culture on a dilute medium supplemented with 10 mM phenol, several steady states were achieved between dilution rates of 0.25 and 1.3 h{sup -1}. Phenol degradation was found to be uncoupled from growth. Immobilized cells grew rapidly in a rich medium, but cell viability plummeted following a switch to a dilute medium supplemented withmore » 5 mM phenol.« less

Rheological observation of glassy dynamics of dilute polymer solutions near the coil-stretch transition in elongational flows.

PubMed

Sridhar, T; Nguyen, D A; Prabhakar, R; Prakash, J Ravi

2007-04-20

It has long been conjectured that the macroscopic dynamics of dilute polymer solutions may exhibit a glasslike slowdown caused by ergodicity breaking, in the vicinity of the coil-stretch transition in elongational flows. We report experimental observations using a filament stretching rheometer that confirm the existence of such glassy states. It is observed that different time-dependent elongational strain-rate profiles lead to a pronounced history dependence and aging effects within a narrow range of strain rates. The results have a direct bearing on the analysis and design of processes employing dilute polymer solutions, such as ink-jet printing, surface coating, and turbulent-drag reduction.

Transformation Model Choice in Nonlinear Regression Analysis of Fluorescence-based Serial Dilution Assays

PubMed Central

Fong, Youyi; Yu, Xuesong

2016-01-01

Many modern serial dilution assays are based on fluorescence intensity (FI) readouts. We study optimal transformation model choice for fitting five parameter logistic curves (5PL) to FI-based serial dilution assay data. We first develop a generalized least squares-pseudolikelihood type algorithm for fitting heteroscedastic logistic models. Next we show that the 5PL and log 5PL functions can approximate each other well. We then compare four 5PL models with different choices of log transformation and variance modeling through a Monte Carlo study and real data. Our findings are that the optimal choice depends on the intended use of the fitted curves. PMID:27642502

Modification of vortex ring formation using dilute polymer solution

NASA Astrophysics Data System (ADS)

Jordan, Daniel; Krane, Michael; Peltier, Joel; Patterson, Eric; Fontaine, Arnold

2006-11-01

This talk will present the results of an experimental study to determine the effect of dilute polymer solution on the formation of a vortex ring. Experiments were conducted in a large, glass tank, filled with water. Vortex rings were produced by injecting a slug of dilute polymer solution into the tank through a nozzle. The injection was controlled by a prescribed piston motion in the nozzle. For the same piston motion, vortex rings were produced for 3 concentrations of the polymer solution, including one with no polymer. The vortex ring flowfield was measured using DPIV. Differences between the 3 cases of polymer concentration in vortex ring formation time, circulation, size, and convection speed are presented.

Development of a thermodynamic model for a cold cycle 3He-4He dilution refrigerator

NASA Astrophysics Data System (ADS)

Mueller, B. W.; Miller, F. K.

2016-10-01

A thermodynamic model of a 3He-4He cold cycle dilution refrigerator with no actively-driven mechanical components is developed and investigated. The refrigerator employs a reversible superfluid magnetic pump, passive check valves, a phase separation chamber, and a series of recuperative heat exchangers to continuously circulate 3He-4He and maintain a 3He concentration gradient across the mixing chamber. The model predicts cooling power and mixing chamber temperature for a range of design and operating parameters, allowing an evaluation of feasibility for potential 3He-4He cold cycle dilution refrigerator prototype designs. Model simulations for a prototype refrigerator design are presented.

Progressing batch hydrolysis process

DOEpatents

Wright, J.D.

1985-01-10

A progressive batch hydrolysis process is disclosed for producing sugar from a lignocellulosic feedstock. It comprises passing a stream of dilute acid serially through a plurality of percolation hydrolysis reactors charged with feed stock, at a flow rate, temperature and pressure sufficient to substantially convert all the cellulose component of the feed stock to glucose. The cooled dilute acid stream containing glucose, after exiting the last percolation hydrolysis reactor, serially fed through a plurality of pre-hydrolysis percolation reactors, charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the hemicellulose component of said feedstock to glucose. The dilute acid stream containing glucose is cooled after it exits the last prehydrolysis reactor.

Husimi-cactus approximation study on the diluted spin ice

NASA Astrophysics Data System (ADS)

Otsuka, Hiromi; Okabe, Yutaka; Nefedev, Konstantin

2018-04-01

We investigate dilution effects on the classical spin-ice materials such as Ho2Ti2O7 and Dy2Ti2O7 . In particular, we derive a formula of the thermodynamic quantities as functions of the temperature and a nonmagnetic ion concentration based on a Husimi-cactus approximation. We find that the formula predicts a dilution-induced crossover from the cooperative to the conventional paramagnets in a ground state, and that it also reproduces the "generalized Pauling's entropy" given by Ke et al. To verify the formula from a numerical viewpoint, we compare these results with Monte Carlo simulation calculation data, and then find good agreement for all parameter values.

Sibship Size and Gendered Resource Dilution in Different Societal Contexts

PubMed Central

Kalmijn, Matthijs

2016-01-01

Resource dilution theory hypothesizes that children’s educational attainment suffers from being raised with many siblings, as the parental resources have to be shared with more children. Based on economic and cultural theories, we hypothesize that resource dilution is gendered: especially a larger number of brothers is harmful to a person’s educational attainment. Using the Survey of Health, Ageing and Retirement in Europe, covering 18 European countries, we show that the number of brothers is more negatively related with the odds of obtaining a college degree than the number of sisters. This holds particularly for women. However, this pattern is weaker in countries that are known to have a more gender-egalitarian climate. PMID:27560371

Thromboresistant surface coatings for the measurement of cardiac output through continuous low flow peripheral A-V shunts.

PubMed Central

Deeb, G M; Borovetz, H S; Griffith, B P; Hardesty, R L

1980-01-01

The dilution technique for determining cardiac output using indocyanine green dye is limited in patients weighing less than 20 kg because of the obligatory volume loss. Reproducible achieved using the green dye dilution method by the establishment of a low flow peripheral arteriovenous shunt. The shunt materials were treated with thromboresistant agents--TDMAC (7%) and albumin (1 g/dl)--to facilitate the use of this technique without heparin. For A-V shunt flow rates of 8-30 cc/min reproducible values of cardiac output were obtained for up to 38 hours which were in good agreement with determinations made using the conventional technique of dye dilution. PMID:6986120

Two-stage, dilute sulfuric acid hydrolysis of wood : an investigation of fundamentals

Treesearch

John F. Harris; Andrew J. Baker; Anthony H. Conner; Thomas W. Jeffries; James L. Minor; Roger C. Pettersen; Ralph W. Scott; Edward L Springer; Theodore H. Wegner; John I. Zerbe

1985-01-01

This paper presents a fundamental analysis of the processing steps in the production of methanol from southern red oak (Quercus falcata Michx.) by two-stage dilute sulfuric acid hydrolysis. Data for hemicellulose and cellulose hydrolysis are correlated using models. This information is used to develop and evaluate a process design.

40 CFR 1065.140 - Dilution for gaseous and PM constituents.

Code of Federal Regulations, 2013 CFR

2013-07-01

... nitrogen. For gaseous emission measurement the diluent must be at least 15 °C. Note that the composition of... chemical balance equations in § 1065.655 to calculate the mole fraction of water in the dilute exhaust... condensation (either measured or from the chemical balance), and set any negative values to zero. This...

40 CFR 1065.140 - Dilution for gaseous and PM constituents.

Code of Federal Regulations, 2011 CFR

2011-07-01

... nitrogen. For gaseous emission measurement the diluent must be at least 15 °C. Note that the composition of... chemical balance equations in § 1065.655 to calculate the mole fraction of water in the dilute exhaust... condensation (either measured or from the chemical balance), and set any negative values to zero. This...

40 CFR 1065.140 - Dilution for gaseous and PM constituents.

Code of Federal Regulations, 2014 CFR

2014-07-01

... nitrogen. References in this part to “dilution air” may include any of these. For gaseous emission... test interval does not exceed the specified limits. (A) Use chemical balance equations in § 1065.655 to... balance), and set any negative values to zero. This difference is the potential mole fraction of the...

40 CFR 1065.140 - Dilution for gaseous and PM constituents.

Code of Federal Regulations, 2010 CFR

2010-07-01

... nitrogen. For gaseous emission measurement the diluent must be at least 15 °C. Note that the composition of... chemical balance equations in § 1065.655 to calculate the mole fraction of water in the dilute exhaust... condensation (either measured or from the chemical balance), and set any negative values to zero. This...

40 CFR 1065.140 - Dilution for gaseous and PM constituents.

Code of Federal Regulations, 2012 CFR

2012-07-01

... nitrogen. For gaseous emission measurement the diluent must be at least 15 °C. Note that the composition of... chemical balance equations in § 1065.655 to calculate the mole fraction of water in the dilute exhaust... condensation (either measured or from the chemical balance), and set any negative values to zero. This...

STATISTICAL ESTIMATES OF VARIANCE FOR 15N ISOTOPE DILUTION MEASUREMENTS OF GROSS RATES OF NITROGEN CYCLE PROCESSES

EPA Science Inventory

It has been fifty years since Kirkham and Bartholmew (1954) presented the conceptual framework and derived the mathematical equations that formed the basis of the now commonly employed method of 15N isotope dilution. Although many advances in methodology and analysis have been ma...

High temperature dilute phosphoric acid pretreatment of corn stover for furfural and ethanol production

USDA-ARS?s Scientific Manuscript database

Furfural was produced from corn stover by one stage pretreatment process using dilute H3PO4 and solid residues following furfural production were used for ethanol production by Saccharomyces cerevisiae NRRL- Y2034. A series of experiments were conducted at varied temperatures (140-200 oC) and acid ...

75 FR 24972 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Cooperative...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-06

... DEPARTMENT OF JUSTICE Antitrust Division Notice Pursuant to the National Cooperative Research and Production Act of 1993--Cooperative Research Group on High Efficiency Dilute Gasoline Engine II Notice is... Research Group on High-Efficiency Dilute Gasoline Engine II, (``HEDGE II'') has filed written notifications...

76 FR 9811 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Cooperative...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-22

... DEPARTMENT OF JUSTICE Antitrust Division Notice Pursuant to the National Cooperative Research and Production Act of 1993--Cooperative Research Group on High-Efficiency Dilute Gasoline Engine II Notice is... Research Group on High-Efficiency Dilute Gasoline Engine II (``HEDGE II'') has filed written notifications...

75 FR 62569 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Cooperative...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-12

... DEPARTMENT OF JUSTICE Antitrust Division Notice Pursuant to the National Cooperative Research and Production Act of 1993--Cooperative Research Group on High Efficiency Dilute Gasoline Engine II Notice is...--Cooperative Research Group on High-Efficiency Dilute Gasoline Engine II, (``HEDGE II'') has filed written...