scholarly journals Correct determination of intrinsic viscosity

1968 ◽  
Vol 12 (4) ◽  
pp. 971-972 ◽  
Author(s):  
O. F. Solomon ◽  
B. S. Gottesman
Keyword(s):  
Intrinsic Viscosity ◽  
Correct Determination

scholarly journals Manufacturing PLA/PCL Blends by Ultrasonic Molding Technology

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2412
Author(s):  
Inés Ferrer ◽  
Ariadna Manresa ◽  
José Alberto Méndez ◽  
Marc Delgado-Aguilar ◽  
Maria Luisa Garcia-Romeu
Keyword(s):  
Molecular Weight ◽  
Crystallization Rate ◽  
Raw Material ◽  
Small Particle Size ◽  
Polymer Mixtures ◽  
Crystallinity Degree ◽  
Correct Determination ◽  
Production Stages ◽  
Process Speed

Ultrasonic molding (USM) is a good candidate for studying the plasticization of polymer mixtures or other composite materials due to either the little amount of material needed for processing, low waste or the needed low pressure and residence time of the mold. Thus, the novelty of this research is the capability of USM technology to process PLA/PCL blends and their corresponding neat materials, encompassing all the production stages, from raw material to the final specimen. The major findings of the work revealed that the thermal properties of the blends were not affected by the USM process, although the crystallinity degree experienced variations, decreasing for PLA and increasing for PCL, which was attributed to the crystallization rate of each polymer, the high process speed, the short cooling time and the small particle size. The employed ultrasonic energy increased the molecular weight with low variations through the specimen. However, the degradation results aligned with the expected trend of these material blends. Moreover, this study also showed the effect pellet shape and dimensions have over the process parameters, as well as the effect of the blend composition. It can be concluded that USM is a technology suitable to successfully process PLA/PCL blends with the correct determination of process parameter windows.

Evaluation of methods for detection of β-lactamase production in MSSA

2021 ◽  
Author(s):  
Robert Skov ◽  
David R Lonsway ◽  
Jesper Larsen ◽  
Anders Rhod Larsen ◽  
Jurgita Samulioniené ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Confirmatory Test ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
Confirmatory Tests ◽  
Correct Determination ◽  
Primary Test ◽  
Zone Edge ◽  
Evaluation Of Methods

Abstract Objectives Correct determination of penicillin susceptibility is pivotal for using penicillin in the treatment of Staphylococcus aureus infections. This study examines the performance of MIC determination, disc diffusion and a range of confirmatory tests for detection of penicillin susceptibility in S. aureus. Methods A total of 286 consecutive penicillin-susceptible S. aureus blood culture isolates as well as a challenge set of 62 MSSA isolates were investigated for the presence of the blaZ gene by PCR and subjected to penicillin-susceptibility testing using broth microdilution MIC determination, disc diffusion including reading of the zone edge, two nitrocefin tests and the cloverleaf test. Results Using PCR-based detection of blaZ as the gold standard, both broth microdilution MIC testing and disc diffusion testing resulted in a relatively low accuracy (82%–93%) with a sensitivity ranging from 49%–93%. Among the confirmatory tests, the cloverleaf test performed with 100% accuracy, while zone edge interpretation and nitrocefin-based tests increased the sensitivity of β-lactamase detection to 96%–98% and 82%–96% when using MIC determination or disc diffusion as primary test, respectively. Conclusions This investigation showed that reliable and accurate detection of β-lactamase production in S. aureus can be obtained by MIC determination or penicillin disc diffusion followed by interpretation of the zone edge as a confirmatory test for apparently penicillin-susceptible isolates. The more cumbersome cloverleaf test can also be used. Nitrocefin-based tests should not be used as the only test for confirmation of a presumptive β-lactamase-negative isolate.

IMPROVEMENT OF THE CAMERAL CHECKS PROCESS IN RUSSIA BASED ON FOREIGN EXPERIENCE

2020 ◽  
Author(s):  
Darya Sergeevna Kareva ◽  
◽  
Sevinj Mahmud kyzy Ismailova ◽  
Elena Evgenievna Dozhdva ◽  
◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Foreign Experience ◽  
Correct Determination

The article substantiates the need to reform cameral tax control in Russia based on the experience of the United States. The necessity of introducing into the procedure of cameral control the mechanism of requesting all documents confirming the correct determination of tax obligations is determined. The aim of improving the process of desk audits of control is that the new procedure for conducting audits will reduce the likelihood of tax violations.

scholarly journals Bee Bread Cells in Honey Super Distort The Results of Pollen Analysis of Honey

2018 ◽  
Vol 62 (2) ◽  
pp. 257-263
Author(s):  
Dariusz Teper ◽  
Piotr Semkiw ◽  
Piotr Skubida ◽  
Mikołaj Borański
Keyword(s):  
Centrifugal Force ◽  
Pollen Analysis ◽  
Reliable Test ◽  
Bee Bread ◽  
Correct Determination

Abstract The pollen analysis is currently the only reliable test to determine honey variety, but the results are sometimes burdened with error. The main reason for this is additional pollen that got into honey in a way other than with nectar collected by bees but through the centrifugation of combs containing bee bread cells. Studies were conducted in 2012 - 2013 on how different numbers of bee bread cells placed in the honey super influence lime honey pollen analysis. Bee bread pollen getting into honey during extraction in centrifugal-force honey extractors was proven to significantly influence the results of pollen analysis. In some extreme cases, it might skew the results so much that correct determination of honey variety by pollen analysis is no longer possible.

scholarly journals Results and recommendations from an intercomparison of six Hygroscopicity-TDMA systems

2010 ◽  
Vol 3 (1) ◽  
pp. 637-674
Author(s):  
A. Massling ◽  
N. Niedermaier ◽  
T. Hennig ◽  
E. Fors ◽  
E. Swietlicki ◽  
...  
Keyword(s):  
Ammonium Sulfate ◽  
Particle Diameter ◽  
Control Unit ◽  
Data Evaluation ◽  
Evaluation Procedure ◽  
Hygroscopic Growth ◽  
Atmospheric Measurements ◽  
Individual System ◽  
Correct Determination

Abstract. The performance of six custom-built Hygrocopicity-Tandem Differential Mobility Analyzers (H-TDMA) systems was investigated in the frame of an international calibration and intercomparison workshop held in Leipzig, February 2006. The goal of the workshop was to harmonize H-TDMA measurements and develop recommendations for atmospheric measurements and their data evaluation. The H-TDMA systems were compared in terms of the sizing of dry particles, relative humidity (RH) uncertainty and consistency in determination of number fractions of different hygroscopic particle groups. The experiments were performed in an air-conditioned laboratory using ammonium sulfate particles or an external mixture of ammonium sulfate and soot particles. The sizing of dry particles of the six H-TDMA systems was within 0.2 to 4.2% of the selected particle diameter depending on investigated size and individual system. With regard to RH uncertainties, the H-TDMA systems showed deviations up to 4.5% RH from the set point at RH=90% investigating the hygroscopic growth of ammonium sulfate particles and comparing the results with theory. The evaluation of number fractions investigating an externally mixed aerosol delivered differences up to +/−8% in calculated number fraction for one and the same aerosol type. We analysed the datasets of the different H-TDMAs with one fitting routine to investigate differences caused by the different data evaluation procedures. The results showed that the differences were reduced from +12/−13% to +8/−6%. We can conclude here that a common data evaluation procedure to determine the number fraction of externally mixed aerosols will improve the comparability of H-TDMA measurements. We finally recommend, to ensure a good calibration of all flow, temperature and RH sensors in the systems. It is most important to thermally insulate the RH control unit and the second DMA and to monitor those temperatures as accurately as 0.2 °C. For a correct determination of external mixtures, it is necessary to take into account size-dependent losses due to the diffusion in the pluming between the DMAs and in the aerosol humidification unit.

scholarly journals UV aerosol indices from SCIAMACHY: introducing the SCattering Index (SCI)

2009 ◽  
Vol 9 (3) ◽  
pp. 13569-13592 ◽  
Author(s):  
M. Penning de Vries ◽  
S. Beirle ◽  
T. Wagner
Keyword(s):  
Aerosol Absorption ◽  
Southeast Usa ◽  
Sulphate Aerosols ◽  
Correct Determination ◽  
High Production ◽  
Absorbing Aerosols ◽  
Scattering Index ◽  
Aerosol Index ◽  
Good Agreement

Abstract. The Absorbing Aerosol Index (AAI) is a useful tool for detecting aerosols that absorb UV radiation – especially in cases where other aerosol retrievals fail, such as over bright surfaces (e.g. desert) and in the presence of clouds. The AAI does not, however, consider contributions from "scattering" (hardly absorbing) aerosols and clouds: they cause negative AAI values and are usually discarded. In this paper, we demonstrate the use of the AAI's negative counterpart, the SCattering Index (SCI) to detect "scattering" aerosols. Maps of seasonally averaged SCI show significantly enhanced values in summer in Southeast USA and Southeast Asia, pointing to high production of "scattering" aerosols (presumably mainly sulphate aerosols and organic aerosols) in this season. The application of a cloud filter makes the presence of "scattering" aerosols even more clear. In a comparison of AOT from AERONET and our Aerosol Indices from SCIAMACHY, good agreement was found for two AERONET stations in Southeast USA, and two stations in Africa. This fact confirms the suitability of SCI as a tool to detect "scattering" aerosols. The combination of the UV Aerosol Indices AAI and SCI provides the unique possibility to characterise absorbing properties of aerosols from space. Accurate knowledge about aerosol absorption is crucial for the correct determination of the contribution of aerosols to the radiative budget.

Single point determination of intrinsic viscosity

1963 ◽  
Vol 7 (4) ◽  
pp. S30-S31 ◽  
Author(s):  
R. Z. Naar ◽  
H. H. Zabusky ◽  
R. F. Heitmiller
Keyword(s):  
Intrinsic Viscosity ◽  
Single Point ◽  
Point Determination

Identification of RAPD markers for percent hull in oat

Genome ◽  
1997 ◽  
Vol 40 (6) ◽  
pp. 873-878 ◽  
Author(s):  
P. S. Ronald ◽  
G. A. Penner ◽  
P. D. Brown ◽  
A. Brûlé-Babel
Keyword(s):  
Quantitative Trait Locus ◽  
Quantitative Trait ◽  
Genetic Factors ◽  
Bulked Segregant Analysis ◽  
Multiple Time ◽  
Test Statistics ◽  
Marker Loci ◽  
Correct Determination ◽  
Trait Locus

Percent hull is an important physical parameter of oat grain quality, but it is affected by environment. Multiple time-consuming evaluations are required to obtain a correct determination of phenotype. The application of marker-assisted selection for the genes involved would greatly simplify the identification of desirable oat genotypes. Bulked segregant analysis, with selected progeny lines derived from a cross between Cascade and AC Marie (30 and 23% hull, respectively), was used to identify randomly amplified polymorphic DNA markers linked to genetic factors controlling primary kernel hull percentage in oat. Twelve polymorphisms, identified between bulks, were tested for linkage to genetic factors controlling hull percentage by genotyping 80 randomly selected F2-derived F8 lines from the progeny population. Three markers showed significant test statistics for quantitative trait locus effects, when tested with primary kernel percent hull data from two environments. Together, the unlinked marker loci OPC13800, OPD20600, and OPK71300 explained approximately 41% of the genetic variance in primary kernel percent hull, after accounting for the main effect of environment.Key words: Avena sativa, hull percentage, bulked segregant analysis, quantitative trait locus.

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