Papers by Keyword: Quantification

Abstract: We discuss the quantification of the secondary electron doping contrast in the scanningelectron microscope on 4H-SiC. It has been observed and studied at length mostly on silicon, but noconclusive theoretical model has been proposed yet. Therefore, we propose a simple physical modelthat allows for a quantification of the doping contrast. It is based on the changes in effective ionizationenergy for different doping concentrations and types. For a better agreement between our model andthe experiment, a locally increased temperature of the electron system or separate quasi Fermi levelsfor electrons and holes have to be assumed. A line profile of the sample under investigation is comparedwith a SRIM simulation of the corresponding implant and shows very good agreement.

Abstract: The aim of this work was to develop and validate RP-HPLC method for quantification of 4 major polyphenolic compounds of mulberry leaf infusion. The mulberry leaf samples were extracted by simulation of tea infusion beverage preparation. HPLC-DAD analysis combined with column C-18 150 mm x 4.6 mm, 2.7 μm was used to determine bioactive polyphenols such as chlorogenic acid, caffeic acid, rutin, and quercetin. The optimal conditions involved the flow rate of mobile phase at 0.3 ml/min with gradient elution of 0.1% formic acid in water and methanol, column temperature at 35 °C, 2 μl injection volume, and the detection wavelength at 320 nm (chlorogenic acid and caffeic acid) and 360 nm (rutin and quercetin). The retention times of chlorogenic acid, caffeic acid, rutin, and quercetin were 25.68, 28.03, 33.97 and 39.11 minutes, respectively. Analysis of four bioactive compounds was found to be linear with a correlation coefficient > 0.99 each at the tested concentration. All other validation parameters that represented accuracy and precision met the AOAC requirements. The developed analytical method was specific, robust, and accurate for simultaneous determining the stated compounds in mulberry leaf extracted with hot water. Moreover, this method could provide the chromatographic profiles of specific cultivar from specific source that could be used to control the quality of mulberry leaf tea products. Different cultivars and different origins of mulberry leaf in this study were also found to present different content of chlorogenic acid, caffeic acid, and rutin. No quercetin was found in the studied samples.

Abstract: The largest comparison of analytical techniques, useful for calcium phosphates, has been conducted, presenting recommendations for quality control and research of calcium phosphates. Results from three classical quantification methods (gravimetry, titramety, photometry) and three instrumental measurement methods (XRF, FAAS ICP-OES) are reported to determine the most accurate, fastest and cheapest analysis method. Remarks are given for increasing the accuracy for each method and corrections made for adsorbed water. For routine analysis, a recommendation is given to ICP-OES for a fast analysis, together with a less frequent use of gravimetry to validate the results and provide a periodic cross-check.

Abstract: The aim of the paper is to explore and establish a base for a possible development of a more holistic and spatially-inclusive method for evaluating energy performance of buildings. This is to be achieved by envisioning building envelopes as arrangements of spatial zones, which could improve the overall energy balance of buildings but at the same time reduce the usage of construction materials and thus consumption of production energy and built-up space. The wall deconstructed in spatial zones, as shown e.g. in Antivilla by Brandlhuber-+, opens a series of questions about the future of existing building codes and certification tools. The potentials are discussed based on the aspects of flexibility, responsiveness, adaptability, replaceability and affordability. The analysis outlines the benefits of the inclusion of those paradigms in the definition of sustainable architecture, and at the same time exposes the lack of possibility to reflect their potential by the established certification criteria. The paper aims at opening the discussion about the limits and traps of quantifying architecture and calls for rethinking of established schemes of sustainability in building sector.

Abstract: A wide-spread approach to foster production and logistics related improvements on a system level is value stream mapping (VSM). It is often used as a starting point for implementing lean manufacturing in producing companies. VSM as a modeling approach contains two major phases – one is the analysis, another one the design phase. During these there is always the question of getting accurate information out of the production system to enable a constructive improvement. It can be distinguished between direct data acquisitions (observation, questioning, interviews) and indirect data acquisition (using IT systems) where both quantitative and qualitative data arises. Standard value stream design (VSD) offers no option to combine these data types, instead mostly deterministic values are used for assessing future states; this can lead to an illusion of accuracy. Thus in this paper it is shown how to combine different data types with an appropriate modeling using fuzzy variables in the course of VSD. The whole procedure is applied during a laboratory study to provide internal validity.

Abstract: Waste generated in construction sites has recently increased and has become an uncontrollable cause of environmental problems and profit loss to contractors. The lack of real data or research on such wastes is due to the lack of suitable policies regarding this issue. The actions of contractors are not controlled by rules on this issue. This situation leads to the lack of action or awareness on the side of the contractor. Concrete waste is also part of the waste generated in construction sites. We determine the concrete waste generated in construction stages and conduct multiple linear regression analysis of the amount of column waste generated. The methodology employed in this study involves site observations, interviews with site personnel, and sampling at housing construction sites. The estimation method is utilized for the sampling of concrete waste. Results show that the average percentage of column waste is 13.93% and that of slab waste is 0.34%. These percentage values are derived from the total order of the concrete. The difference is due to the sizes of structures and method of handling. The regression model obtained from the sample data on column waste resulted in an adjusted R² value of 0.895. Therefore, the model predicts approximately 89.5% of the factors involved in concrete waste generation.

Abstract: In recent years, despite the significant improvement of sequencing technologies such as the pyrosequencing, rapid evaluation of microbial community structures remains very difficult because of the abundance and complexity of organisms in almost all natural microbial communities. In this paper, a group of phylum-specific primers were elaborately designed based on a single nucleotide discrimination technology to quantify the main microbial community structure from GuJingGong pit mud samples using the real-time quantitative PCR (qPCR). Specific PCR (polymerase chain reaction) primers targeting a particular group would provide promising sensitivity and more in-depth assessment of microbial communities.

Abstract: Ultrasonic guided wave quantitative detection technology has not been widely studied; this limits the application and development of guided waves testing technology greatly. For the quantitative detection study of notches in pipes, the theoretical model of guided waves interacted with notches has been built. Through the model, the relation formula between reflection coefficient and defects axial length and depth has been derived. The relation curves have been plotted based on the relation formula. And then, experiment method was used to verify the curves, the two methods can agree with each other. At last, the size of the defect was evaluated through the theoretical relation curves, the evaluation agrees with the practical size relatively. The research results provide necessary guide in theory to the defects quantification of guided wave detection.

Abstract: The quantitative classification of transformer supervision can improve the quality of transformer supervision. For the contents of transformer supervision, this paper establishes an index system of transformer supervision. Example results show that the extension matter-element theory which is applied to transformer supervision quantitative evaluation is more reasonable. According to the categories of transformer supervision, this paper quantifies the uncertainty and builds the evaluation system of transformer supervision. It realizes the evaluation of transformer supervision and gets the key factors which influence the transformer supervision. This evaluation system is conducive to guide the transformer supervision to be more scientific and effective.

Abstract: The grounding performance plays a very important role on system level EMC. This paper puts forward several key indicators that can greatly affect grounding performance. According to the characteristics of each kind of original data, fuzzy clustering method is adopted to quantify it. Then, based on the method of TOPSIS (Technique for Order Preference by Similarity to Ideal Solution), closeness degree model is established to achieve the comprehensive evaluation of the system grounding performance.