scholarly journals Efficient Techniques for Solution of Complex Computational Tasks in Building Physics

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Václav Kočí ◽  
Jiří Maděra ◽  
Tomáš Krejčí ◽  
Jaroslav Kruis ◽  
Robert Černý
Keyword(s):  
High Performance ◽  
Computational Homogenization ◽  
Optimization Techniques ◽  
Time Saving ◽  
Effective Media ◽  
Effective Media Theory ◽  
Hygrothermal Performance ◽  
Building Physics ◽  
Single Material

Various simplification or optimization techniques are sought that reduce demands of computational modeling on time or computing power while keeping a sufficient level of accuracy. In this paper, determination of hygrothermal performance of a brick block is presented using two homogenization techniques based on different principles. While the computational homogenization technique uses a multiscale method realized on the master/slave computer system, the materials homogenization comes out from the effective media theory (EMT), and after the determination of effective material properties, the whole isotropic problem can be transformed to one dimension. Contrary to most applications of EMT, free parameters of mixing formulas are not determined based on an experimental measurement of a single material property but on a complex hygrothermal performance of the element where the distribution of moisture and temperature over a reference year is taken into account. The calculated results from both techniques are compared with results obtained by high-performance computing without any computational simplifications. For materials homogenization, the best results are achieved when k = 0.9 in Lichtenecker’s mixing rule is assumed, which corresponds to a nearly parallel arrangement of the block. The root mean square error (RMSE) of relative humidity (RH) and temperature distribution is only 0.992% and 0.566°C, respectively. This is even better than the results of computational homogenization (RMSE: 1.502% of RH and 0.629°C). Besides obtaining sufficiently precise results, a significant time-saving is achieved, accounting for more than 99%, while being solved on a single-processor computer.

Determination of Abamectin Residues in Edible Oils by High-Performance Liquid Chromatography with Fluorescence Detection

2014 ◽  
Vol 97 (3) ◽  
pp. 928-932 ◽  
Author(s):  
Xue-Xue Miao ◽  
Yuan-Yuan Yang ◽  
Xiao-Yun Yang ◽  
Qi-Liang Huang ◽  
Hai Hong
Keyword(s):  
High Performance Liquid Chromatography ◽  
Fluorescence Detection ◽  
Mobile Phase ◽  
High Performance ◽  
Detection Method ◽  
Edible Oils ◽  
Edible Oil ◽  
Time Saving ◽  
Satisfactory Precision

Abstract A rapid and simple HPLC-fluorescence detection method has been developed for the determination of abamectin residues in edible oil. Residues are extracted with acetonitrile and by vortexing and then directly derivatized with no need for a time-consuming cleanup step. Trifluoroacetic anhydride and N-methylimidazole were used as derivatizing agents of abamectin. Abamectin was detected and quantitated with fluorescence detection (excitation: 365 nm; emission: 475 nm), and methanol was used as the mobile phase. The LOD was 0.001 mg/kg and the LOQ was 0.003 mg/kg. The recoveriesranged from 86 to 100.4% with satisfactory precision (RSD < 10.1%). This method proved to be sensitive, environmentally friendly, time-saving, and efficient.

Analysis of Thermal Conductivity of Lime Plaster with Pozzolanic Addition by Different Homogenization Techniques

2014 ◽  
Vol 982 ◽  
pp. 1-5
Author(s):  
Jan Fořt ◽  
Lukáš Fiala ◽  
Milena Pavlíková ◽  
Zbyšek Pavlík ◽  
Robert Černý
Keyword(s):  
Thermal Conductivity ◽  
Pulse Method ◽  
Measured Data ◽  
Media Theory ◽  
Practical Applications ◽  
Effective Media ◽  
Effective Media Theory ◽  
Lime Plaster ◽  
Water Saturated

Thermal conductivity of lime-pozzolan plaster is analyzed in the paper. At first, determination of basic physical properties of tested material is done for its basic characterization, as well as for the assessment of input parameters in the subsequent analysis of measured data by different homogenization techniques. The measurements of thermal conductivity are performed in dependence on moisture content from the dry state to the fully water saturated state using transient pulse method. Among the homogenization techniques based on effective media theory, Lichtenecker’s and Dobson’s models are used. The measured data presented in this paper can find utilization in practical applications of the studied plaster. The analyzed homogenization techniques are found to be applicable for a rapid evaluation of moisture dependent thermal conductivity.

scholarly journals High-Performance Liquid Chromatographic and First Derivative of the Ratio Spectrophotometric Determination of Amlodipine and Valsartan in Their Binary Mixtures

2010 ◽  
Vol 93 (3) ◽  
pp. 882-890 ◽  
Author(s):  
Dilek Kul ◽  
Burcu Dogan-Topal ◽  
Tugba Kutucu ◽  
Bengi Uslu ◽  
Sibel A Ozkan
Keyword(s):  
Spectrophotometric Method ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Time Saving ◽  
Pharmaceutical Dosage Form ◽  
First Derivative ◽  
Significant Difference ◽  
Long Acting

Abstract Amlodipine besylate (AML) is a long-acting calcium channel blocker used as an antihypertensive agent. Valsartan (VAL) is also used to treat hypertension, either alone or in combination with other agents. Two-component mixtures of AML and VAL were analyzed by HPLC and the ratio spectra of the first derivative spectrophotometric technique. The spectrophotometric method depends on the first derivative of the ratio-spectra by measurements of the amplitudes at 234.0 nm for VAL and 351.0 nm for AML. Calibration graphs were established for 0.520 g/mL AML and 132 g/mL VAL using the ratio spectra of the first derivative spectrophotometric method. In the HPLC method, an ACE 5 C18 (4.6 150 mm, 5 m) RP column at 30C with the mobile phase methanolacetonitrileNaH2PO4H2O buffer, including 5 mL/L triethylamine and adjusted to pH 3.0 (42 + 18 + 40, v/v/v) at 2.0 mL/min flow rate was used to separate both compounds with detection at 254.0 nm. Linearity was obtained in the concentration range of 0.5500 g/mL for AML and 5.0900 g/mL for VAL. The proposed methods have been extensively validated. These methods allow a number of cost- and time-saving benefits. They were successfully applied to the determination of AML and VAL in synthetic mixtures and in a pharmaceutical dosage form. There was no significant difference between the performance of the proposed methods regarding the mean and SD values. The proposed methods are simple, rapid, and suitable for QC applications.

scholarly journals Monitoring of Aflatoxin B1 in Dry Aged Meats using a modified HPLC-FLD method

2021 ◽  
Vol 26 (4) ◽  
pp. 2885-2891
Author(s):  
HATICE AHU KAHRAMAN ◽  
HIDAYET TUTUN
Keyword(s):  
Aflatoxin B1 ◽  
High Performance ◽  
Limit Of Detection ◽  
Meat Products ◽  
Performance Parameters ◽  
Limit Of Quantification ◽  
Time Saving ◽  
Modified Method ◽  
Meat Samples

The presence of aflatoxins residues in meat and meat products occurs through ingestion of feeds contaminated with Aflatoxin B1 (AFB1) or during the processing of the meat products. Little research has been conducted concerning the detection of AFB1 on meat. The aim of this study was to modify the method for AFB1 determination by high performance liquid chromatography with fluorescence detection in dry aged meats. The aged meat samples used for determination of AFB1 were obtained from a commercial dry aged meat plants and produced for 28 days in a meat plant chiller. All meat samples were analyzed according to the modified method. The samples were cleaned to remove impurities by using a immunoaffinity column. Photochemical reactor was used for the recording and evaluation of the chromatograms. The analytical performance parameters showed that the method was specific for AFB1 detection in the meat samples. Recovery rate, reproducibility (RSDr%) and repeatability (RSDR%) were found to be 85.889%, 3.822% and 6.601%, respectively. Limit of detection and limit of quantification were 0.15 ng/mL and 0.501 ng/mL, respectively. AFB1 was not detected in the meat samples. Our results indicated that the method modified for monitoring AFB1 level in the meats was simple, time-saving and reliable.

Fluoroimmunoassay Based on FITC-Labeled Antibody for the Determination of Estradiol

2014 ◽  
Vol 960-961 ◽  
pp. 3-6
Author(s):  
Long Jun Wang ◽  
Wei Li Xue ◽  
Ling Yun Du
Keyword(s):  
Human Urine ◽  
High Performance ◽  
Solid Phase ◽  
High Sensitivity ◽  
Good Precision ◽  
Experimental Conditions ◽  
Time Saving ◽  
Relevant Variable ◽  
Relative Standard

A new fluorescence immunoassay with high sensitivity, time-saving, good precision and reliablility was proposed for the determination of estradiol (E2) in human urine. The complex of FITC-labeled anti-E2antibody was produced and regarded as a probe in this system. Ninety-six microplate was coated with ovalbumin conjugated E2antigen as solid phase for the immunoassay. The method parameters affecting the determination, such as the concentration of immunoreagents, pH, and other relevant variable conditions upon the immunoassay were studied and optimized systematically. Under the optimal experimental conditions, it was found that the proposed method exhibited high performance with the detection limit of 9.2 pg/mL, and the linear range of determination of 0.01-1000 ng/mL. The recoveries were 93.58-105.82% with the relative standard deviations (RSD) 5.52-7.09%. The proposed method has been used for the determination of E2in human urine with satisfactory results, and may be expected to find wide application in other environmental samples.

scholarly journals Determination of dehydroepiandrosterone in dietary supplements by reversed-phase HPLC

2022 ◽  
Vol 20 (2) ◽  
pp. 383-387
Author(s):  
Yahia Z. Tabaza ◽  
Kamal M. Mansi ◽  
Hanan A. Azzam ◽  
Farah F. Al-Mamoori ◽  
Ali M. Al-Samydai ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Dietary Supplements ◽  
High Performance ◽  
Cost Effective ◽  
Reversed Phase ◽  
Hplc Method ◽  
Time Saving ◽  
Relative Standard

Purpose: To develop a reversed phase high performance liquid chromatography (HPLC) method for the determination of dehydroepiandrosterone (DHEA) in dietary supplements. Methods: A reversed-phase high performance liquid chromatography (HPLC) method was developed for the determination of DHEA in dietary supplements. An isocratic system consisting of methanol and water (70:30 v/v) was run at a flow rate of 1 mL/min on a C18 HPLC column to achieve the separation. The method was validated with regard to linearity, intra-day and inter-day precision, and limits of both detection and quantification. Results: The method achieved a retention time of 10.8 min, a resolution of 4.12, a detection limit (LOD) of 50 ng/μL, a quantification limit (LOQ) of 166.7 ng/μL and a label claim of 108.6 % with a relative standard deviation (RSD) of 0.38 % over a range of 0.0625 – 0.50 mg/mL with a correlation coefficient of 0.9997. Conclusion: The method is simple, cost effective, time-saving and reliable for determining DHEA when compared to other reported methods in literature. Thus, it will be of benefit to manufacturers of this dietary supplement to adopt the method for quantitative laboratory analysis.

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