Different Methods For Determination Research Articles

Comparation of different methods for determination of Cannabis inflorescences humidity

Comparation of different methods for determination of Cannabis inflorescences humidity

Evaluation of the suitability of different methods for determination of the crosslink density in highly filled EPDM compounds

The crosslink density of elastomers is the essential property that determines many other but especially the mechanical product properties. Different raw materials, especially recycled and bio-based materials, influence the vulcanization and may change the crosslink density when they are used as a substitute to conventional raw materials. Aim of this study is to develop a procedure that allows the reliable determination of the crosslink density in highly filled EPDM compounds as basis for future investigations focussed on substitution with sustainable materials in this compound. Unfortunately, experiences with other rubber compounds like tire treads cannot be directly applied here because of the use of other filler types and amounts as well as the differences in the polymer with regard to active sites (available double bonds). Equilibrium swelling, Flory-stress-strain-measurements, freezing point depression and temperature-scanning-stress-relaxation are applied to a model EPDM compound with high filler and softener amount as typically used for sealings. For sensitivity investigation the amount of the crosslink agent sulfur was varied. Furthermore, the influence of different accelerators was investigated. All methods are able to determine the crosslink density but with different standard deviations due to measurement errors. Partially, they can be optimized for this use case. Based on the results a combination of Flory-stress-strain-measurements and freezing point depression was chosen to be used in the future.

Exciton Binding Energy of MAPbI3 Thin Film Elucidated via Analysis and Modeling of Perovskite Absorption and Photoluminescence Properties Using Various Methodologies

This work presents spectroscopic investigations of methylammonium lead iodide, MAPbI3, a perovskite thin film, with a focus on elucidating the exciton binding energy of the semiconductor via various approaches in modeling of absorption and photoluminescence spectroscopic data collected in the 150–293 K temperature range. These include the application of modified versions of Elliott’s formula to reconstruct steady-state absorption of the semiconductor in the spectral range of the bandgap edge, validated by conjunction with outcomes from transient absorption spectroscopy, and application of numerous variations of the Arrhenius equation to model temperature-induced broadening of the excitonic absorption band and temperature-dependent changes in intensity of photoluminescence emission spectra. All these approaches were simultaneously applied on the spectroscopic data acquired on the same MAPbI3 sample and provide a more comprehensive image of how the value of exciton binding energy depends on the determination methodology. This work demonstrates that after excluding outliers originating most likely from the application of inappropriate fitting models, the exciton binding energy falls within the narrow 7–17 meV energetic range. This study shows that better agreement between different methods of determination of exciton binding energy from analysis of absorption and photoluminescence spectra could be achieved if correct fitting models are applied, and other variables, as for example sample aging, are excluded.

МОДЕЛИРОВАНИЕ РАЗОГРЕВА ЭНЕРГЕТИЧЕСКИХ МАТЕРИАЛОВ

An analysis of the known approximations for describing the dependence of the heat capacity at a constant volume of energetic materials (molecular crystals) on the crystal temperature has shown that there are reliable approximations of the dependence of the heat capacity at a constant volume that do not require complex quantum mechanical calculations to determine the frequencies of normal vibrations, both intermolecular and inside the molecule. To obtain the dependence of the thermal part of the internal energy of a molecular crystal, which is responsible for heating the material, it is required to integrate the heat capacity expression at constant volume over temperature. In this work, calculations have been made for the dependence of the thermal part of the internal energy of a molecular crystal in case when it is calculated through the frequencies of normal vibrations, and in case when it is calculated by integrating the heat capacity at a constant volume with respect to temperature using approximation formulas. When solving the spectral problem of determining the frequencies of normal vibrations within the molecule, the PM3 and DFT quantum chemical methods have been used. The paper presents the dependences of the thermal part of the internal energy of molecular crystals on temperature, calculated for different methods of determination, and a comparative analysis, which has shown that the difference has equaled less than 1 %.

Different methods for determination of shale volume for Yamama formation in an oil field in southern Iraq

The determination of the shale volume is necessary for formations properties, because it is important for computing fluid content, formation porosity and formation permeability. Different methods of determining shale volume such as Clay Indicators and Double Clay Indicators can be applied to obtain results with high accuracy. Single Clay Indicators includes several methods, the most important of which from gamma ray, Resistivity log and Neutron log. Double Clay Indicators include three methods, Density – Acoustic cross-plot, Density- Neutron cross plot and Acoustic- Neutron cross plot. The excellent way for identifying the rock formation has been achieved by using the above methods whilst determination of the magma from only one method does not reach perfect findings. Moreover, the results of these methods are closely similar which give us a confidence in the obtained findings. In this study, applying these methods in Yamama Formation in an oil field in southern Iraq that the volume of shale calculated using the gamma ray method was less than 10%, while the volume of shale calculated using the neutron method was less than 12%, and the volume of shale calculated by the Resistivity Cross plots method, it was less than 10%, and it was also less than 10% using the Sonic -Density Cross plots method, Neutron -Density Cross plots method, and Neutron -Sonic Cross plots method. The comparison of these methods shows that the volume of shale calculated by the gamma ray log was more accurate than Neutron log, because the all other methods were matched with Gamma ray log.

Unified model for the prediction of consecutivesolid–liquidfiltration and expression at the constant pressure

AbstractUnified nonlinear model is proposed for the prediction of consecutive solid–liquid filtration and expression at the constant pressure. This model is based on the Darcy–Terzaghi filtration‐consolidation equations modified to consider power‐law pressure dependence of the specific cake resistance, and transforming Darcy law to the linear form. The model considers nonuniform structure of compressible filter cakes obtained by filtration and following expression. The profiles of local compressive pressure and local cake characteristics are simulated and compared for different moderately and highly compressible filter cakes (H.K. kaolin, CaCO3, silica, activated sludge) based on the analytical and numerical solutions of the model. It is shown that the behavior of solid–liquid expression depends from the initial structure of compressed materials. Consolidation ratioUof the filter cakes with initially nonuniform structure formed by filtration differs from that of semi‐solid materials with initially uniform structure. Different methods of determination of consolidation coefficient are analyzed and compared for nonuniformly structured filter cakes.

Comparison of a Deep Learning Algorithm vs. Humans for Vertebral Heart Scale Measurements in Cats and Dogs Shows a High Degree of Agreement Among Readers.

Heart disease is a leading cause of death among cats and dogs. Vertebral heart scale (VHS) is one tool to quantify radiographic cardiac enlargement and to predict the occurrence of congestive heart failure. The aim of this study was to evaluate the performance of artificial intelligence (AI) performing VHS measurements when compared with two board-certified specialists. Ground truth consisted of the average of constituent VHS measurements performed by board-certified specialists. Thirty canine and 30 feline thoracic lateral radiographs were evaluated by each operator, using two different methods for determination of the cardiac short axis on dogs' radiographs: the original approach published by Buchanan and the modified approach proposed by the EPIC trial authors, and only Buchanan's method for cats' radiographs. Overall, the VHS calculated by the AI, radiologist, and cardiologist had a high degree of agreement in both canine and feline patients (intraclass correlation coefficient (ICC) = 0.998). In canine patients, when comparing methods used to calculate VHS by specialists, there was also a high degree of agreement (ICC = 0.999). When evaluating specifically the results of the AI VHS vs. the two specialists' readings, the agreement was excellent for both canine (ICC = 0.998) and feline radiographs (ICC = 0.998). Performance of AI trained to locate VHS reference points agreed with manual calculation by specialists in both cats and dogs. Such a computer-aided technique might be an important asset for veterinarians in general practice to limit interobserver variability and obtain more comparable VHS reading over time.

Theoretical Calculations of pKa Values for Substituted Carboxylic Acid

Six different methods of determination have been used for studying ten derivatives of carboxylic compounds. Semi-empirical (AM1 and PM3), Hartree Fock (HF/STO-3G and HF/3-21G), and Density Function Theory (DFT/STO-3G and DFT/6-31G) were employed to calculate many physical theoretical parameters. The calculated data were correlated with experimental values of pKa using different regression(enter, stepwise and simple regression). Depending on the Fisher values, (HF/STO-3G) was shown as the best method for predicted of the pKa data compare to the (PM3) method using enter method. While (HF/3-21G)method has a big value of fisher compared with(PM3) using (stepwise) and (simple) methods. So, Multiple linear regression was performed to obtain the best prediction values using (enter) compare with (stepwise), and the two methods are the best compared with simple regression.

Assessment of antinuclear antibodies (ANA): National recommendations on behalf of the Croatian society of medical biochemistry and laboratory medicine.

Antinuclear antibodies (ANA) represent a family of autoantibodies targeting ubiquitous cellular constituents and are a hallmark of systemic inflammatory autoimmune rheumatic diseases named connective tissue diseases (CTD). The gold standard method for ANA determination is indirect immunofluorescence (IIF) on the human laryngeal epidermoid carcinoma cell line type 2 substrate (HEp-2), but with increasing demand for ANA testing, novel methods eased for automation emerged, which allows testing by staff less experienced in this specific field of laboratory diagnostic. In 2016 The working group (WG) for laboratory diagnostics of autoimmune diseases as part of the Committee for the Scientific Professional Development of the Croatian Society of Medical Biochemistry and Laboratory Medicine (CSMBLM) published the data of a survey regarding general practice in laboratory diagnostics of autoimmune diseases in Croatia. Results indicated high diversity in the performance of autoantibody testing as well as reporting of the results and indicated the need of creating recommendations for the assessment of ANA that would help harmonize diagnostics of systemic autoimmune rheumatic diseases in Croatia. This document encompasses twenty-seven recommendations for ANA testing created concerning indications for ANA testing, preanalytical, analytical, and postanalytical issues, including rational algorithm and quality control assurance. These recommendations are based on the relevant international recommendations and guidelines for the assessment of ANA testing and relevant literature search and should help to harmonize the approach in ANA testing and clarify differences in interpretation of the results obtained using different methods of determination.

P37.09 Comparison of 3 Different Methods for Determination of EGFR p.Thr790Met mutation in patients with NSCLC

P37.09 Comparison of 3 Different Methods for Determination of EGFR p.Thr790Met mutation in patients with NSCLC

Characteristics of clinical, laboratory, and immunological manifestations in patients with anticentromere antibody-associated Sjögren's disease

Objective: to study clinical and laboratory features in patients with anticentromere antibody (ACA)-positive SjЪgren's disease (SD), as well as the sensitivity of different methods for determination of ACA, and to elaborate an algorithm for differential diagnosis in ACA-positive patients.Patients and methods. The V.A. Nasonova Research Institute of Rheumatology followed up 136 patients who were highly positive for ACA. The investigators used the 2001 Russian criteria for the diagnosis for SD; the 2013 ACR/European League Against Rheumatism (EULAR) criteria for that of scleroderma systematica (SDS); the guidelines of the American Association for the Study of Liver Diseases, the Russian Gastroenterological Association, and the Russian Society for the Study of the Liver for that of primary biliary cholangitis (PBC)/biliary duct epitheliitis in the presence of SD. Lymphomas were diagnosed by biopsies of affected organs according to the WHO classification. SD was diagnosed in 119 patients; SDS in 49 cases (37 with SDS concurrent with SD and 12 with isolated SDS), PBC/biliary duct epitheliitis in 23 (all cases with PBC/biliary duct epitheliitis concurrent with SD and/or SDS); 5 patients were excluded from the investigation. Further analysis included 131 ACA-positive patients. The patients were divided into three groups: SD (n=82 or 62.6%); SD+SDS (n=37 or 28.24%); SDS (n=12 or 9.16%).Results and discussion. Autoantibodies to centromere peptide (CENP) A and CENP-B in the same titers were detected in all ACA-positive patients, regardless of diagnosis. Comparative analysis of three patient groups revealed no statistically significant differences in the frequency of laboratory deviations. The signs characteristic of classical SD (rheumatoid factor (RF)), anti-Ro and anti-La antibodies, leukopenia, higher ESR values, hypergammaglobulinemia, and elevated IgG/IgA levels) were found in a small proportion of patients. The frequency and severity of glandular manifestations did not differ in SD and SD + SDS. PBC/biliary duct epitheliitis was present in 17.5% of ACA-positive patients (in most antimitochondrial antibody-positive cases); no statistically significant differences in its frequency were found between the groups. Other extraglandular manifestations in SD and SD + SDS were identified in a smaller number of patients. All sclerodermic spectrum manifestations were more common in SD and SD + SDS than in BS. Pulmonary arterial hypertension was not diagnosed in any patient from the SD group. MALT lymphomas were detected in 19 ACA-positive patients. Those were present only in BS patients and absent in the SDS group. MALT lymphomas developed in the first 10 years after the onset of SD. The transformation of MALT lymphoma into diffuse large B-cell lymphoma was observed in 2 patients. The main signs of lymphomas in SD patients were persistent parotid salivary gland enlargement, decreased levels of complement C4 and peripheral blood CD19+ cells, as well as cryoglobulinemic vasculitis, serum monoclonal secretion, lymphoid infiltration in the minor salivary glands (a focus score of >4), and severe damage to the salivary and lacrimal glands.Conclusion. ACA-associated SD is an independent disease subtype characterized by an increased risk for SDS, PBC, and MALT lymphomas and by a low frequency of the systemic manifestations and laboratory signs characteristic of classical SD. Regardless of the detected type of antibodies and the presence or absence of extraglandular manifestations, damage to the salivary and lacrimal glands progresses in SD, which often leads to lymphomas; therefore, the therapy that may prevent this complication should be initiated as soon as possible after SD diagnosis. The lymphoproliferation signs identified in this investigation should be taken into account in all ACA-positive patients with SD for the early diagnosis of lymphoid tumors before therapy is prescribed. An algorithm for differential diagnosis in seropositivity for ACA is presented. Determination of autoantibodies to CENP-A and CENP-B does not allow the differential diagnosis in ACA-positive patients.

Simplified determination of commissural orientation in bicuspid aortic valves.

In bicuspid aortic valves (BAV), commissural orientation (CO) varies between 180° and close to 120°. Postoperative CO has a strong effect on repair durability, and different repair approaches have been proposed according to CO; it is thus important for aortic repair. A precise, simple and reproducible determination by preoperative echocardiography would facilitate intraoperative decision-making. We compared 4 different methods of determination of CO in BAV. Preoperative transoesophageal echocardiograms of 62 patients with BAV were analysed. CO was measured using either the coaptation centre or the geometric centre of the root. The geometric centre of the root was determined through approximation using a circle or an ellipse, or the midpoint of a line between the centre of the non-fused and the fused sinuses. The 3 different geometric methods led to almost identical results (interclass coefficient 0.98-0.99), with the line segment being the easiest to use. The use of the coaptation centre was associated with the underestimation of commissural angle of up to 30° compared to the geometric centre; the discrepancy was significant and most pronounced for asymmetric BAV (140-160°; P = 0.005). CO can reproducibly be determined using a line segment between the centre of the non-fused and fused sinuses. The use of the coaptation centre can lead to misleading results, in particular in asymmetric BAVs.

Lead – factors affecting its content in bone tissue

Abstract Lead is an element whose presence in the environment results mainly from man’s activities. It infiltrates the bodies of living organisms in many ways; in the human body, it has a multidirectional activity, causing anemia, kidney damage, mental retardation in children, genotoxicity, impaired immune function, damage to the nervous system and an inhibition of heme synthesis. Lead also affects bones; its concentrations there, in contrast to soft tissues, are dependent on exposure and increase throughout ones lifespan. This element is the most often studied and described metal in the bone tissue. The aim of this study was to determine the factors that influence the content of lead in the bone tissue and trace its content in this tissue based on literature data. The analysis of the collected literature showed an incredibly wide range of lead content in human bones was observed. This could be due to the different methods of determination (AAS, ICP-AES, K x-ray fluorescence) and the weight of the sample (dry or wet).

A Comparison between Different Methods to Study the Supermassive Black Hole Mass - Pitch Angle Relation

In this study, we compared the different Methods of determination of SMBH masses to study a correlation between mass of supermassive black hole and spiral arm pitch angle for 41 images of spiral galaxies using Spitzer/IRAS 3.6-µm. We selected four methods to find a determination mass of SMBH. Velocity dispersions (σ) measurements and pitch angle of spiral arm took from the literature. In addition, SMBH masses estimates using a several methods (reverberation mapping RM, stellar dynamics SD, gas dynamics GD) from the literature from. In addition, the determinations of SMBH masses were found using the (MBH-σ) relation. Finally, we compared the (MBH-P) relation for these galaxies using each method with the Seigar’s equation, and found the results to agree for these methods.

Thermal Properties of Na2O-MgO-TiO2-Al2O3-B2O3-SiO2 Glasses and Prospects for Their Use for Sealing Solid Oxide Fuel Cells

A series of Na2O-MgO-TiO2-Al2O3-B2O3-SiO2 glasses promising as sealants for solid oxide fuel cells are prepared. The glassy state is confirmed by X-ray diffraction analysis, and the elemental composition is determined by inductively coupled plasma atomic emission spectroscopy. The coefficient of thermal expansion (CTE) is calculated from the dilatometric data; it varies within (69–77) × 10−7 K−1 and increases with the MgO to Al2O3 concentration ratio. The CTE calculation by the Appen method gives the results that are underestimated by 5–8% relative to the experimental data. The temperature dependences of the heat capacity of the glasses are determined by differential scanning calorimetry and calculated using the Kopp-Neumann rule. Comparison of the calculated values with the experimental data shows that the Kopp-Neumann rule is observed for the systems under consideration with relatively high accuracy. The sensitivity of different methods in determination of the glass transition point has been evaluated.

Comparison of two different methods for determination of parathyroid hormone in homeostasis bone metabolism

Comparison of two different methods for determination of parathyroid hormone in homeostasis bone metabolism

Review of Specific Heat Capacity Determination of Lithium-Ion Battery

This paper reviews different methods for determination of specific heat capacity of lithium-ion batteries. Thermal modelling of lithium-ion battery cells and battery packs is of great importance. The specific heat capacity of the battery is an essential parameter for the establishment of the thermal model, and it is affected by many factors (such as SOC, temperature, etc.). The scientific purpose of this paper is to collect, sort out and compare different measurement methods of specific heat capacity of battery. The advantages and disadvantages of different methods are discussed. The applicability of each measurement method for various battery types and the required experimental conditions are discussed. The factors influencing the specific heat capacity of the battery are also summarized.

Progress in separation and purification of nattokinase and its enzyme activity determination

In this paper, the separation and purification of nattokinase have been reviewed by primarily focusing on solvent precipitation, adsorption column chromatography, magnetic microspheres, expanded bed, reverse micelle, and three-phase separation methods. The different methods for determination of the enzyme activity have been discussed and compared. Finally, the feasibility that the nucleic acid-based identification techniques can be used for nattokinase purification and enzyme activity assay has been proposed.

Understanding beef flavour and overall liking traits using two different methods for determination of thiobarbituric acid reactive substance (TBARS)

Two extraction methods were applied to measure the thiobarbituric acid reactive substances (TBARS) values of vacuum packaged grass-fed beef steaks that were aged under four temperatures and five different time interval combinations to capture a range in lipid oxidation. The relationships between TBARS values and consumer assessment of flavour liking, flavour intensity and overall liking, were examined. M1 values had a normal distribution (0.02 to 2.55 mg MDA/kg), whereas M2 had a skewed distribution with the majority of the values <1.0 mg MDA/kg and the maximum value being 10.72 mg MDA/kg. No relationship was found between these methods. Interestingly, there were no significant effects of TBARS value on the sensory results, irrespective of the method used. This suggests that untrained consumers cannot detect abnormal flavour development due to high levels of lipid oxidation (TBARS) as indicated by the TBARS test, and are therefore undiscouraged when tasting these beef samples.

Asma Yaprak Alanın Belirlenmesinde Farklı İki Yöntemin Karşılaştırılması

Bitkilerde fotosentez, transpirasyon, solunum gibi birçok hayati mekanizmayı kontrol eden yapraklar, bilimsel çalışmalarda tür ya da çeşit tespitinin yapıldığı, bitkinin çeşitli stres şartlarına olan tepkisinin ölçüldüğü temel organlardır. Yaprakların yüzey alanının tespiti de birçok çalışmaya ışık tutmaktadır. Bu çalışmada yaprak alanını belirlemede iki farklı yöntemin karşılaştırılması amaçlanmıştır. Kullanılan birinci yöntemle görüntü işleme programı Photoshop CS6 kullanılarak piksel değerleri üzerinden piksel-alan hesaplaması ile yaprak alanını tespit edilmiştir. Bir diğer yöntem ise ağırlık-alan ilişkisinden yararlanılarak, yaprak alanı belirlenmeye çalışılmıştır. Ele alınan 28 farklı yerel üzüm çeşidinin yapraklarında iki yöntem arasındaki alanının-12.93-9.2 cm2 arasında değişim gösterdiği belirlenmiştir. Çalışmada iki yöntem karşılaştırılarak her çeşit için yaprak alan katsayısı saptanmıştır. Bilgisayarda taranan ve Adobe Photoshop 6.0 programı ile belirlenen alan ile ağırlık alan ilişkisi yöntemi kullanılarak belirlenen alan arasındaki regresyon katsayısı R2=0.908 (p&amp;lt;0.0l) olarak bulunmuştur. İki yöntem arasındaki bu ilişkinin istatistik olarak önemli olması, bilgisayarla tespitin mümkün olmadığı durumlarda ağırlık-alan ilişkisinden yararlanılarak yaprak alanlarının hesaplanabileceğini göstermektedir.