Method For Determination Of Number Research Articles

An improved method for determining the water number for surfactants

Surfactants have a significant role in everyday life and various industries. Their amphipathic nature significantly influences their properties, functions, and applicability. The ratio of water and oil solubility is characterized by the HLB value (hydrophilic-lipophilic balance) or the closely related water number.A determination of the water number of surfactants represents the amount of water that a surfactant can incorporate into a microemulsion. The results of measuring the water number provide information about the hydrophilic properties of the surfactant in question. Understanding the water number helps determine the applicability of surfactants. From the water number of surfactants, conclusions can be drawn about the HLB value of the particular surfactant, providing further insights into its properties. Although a well-established method for determining water number has long been available, it has been revealed that many of the auxiliary substances and chemicals used in this process have severe health-damaging effects, leading to their discontinuation in routine laboratory use.Our goal was to find a solvent combination that would be suitable for the water number determination method. Additionally, we aimed to investigate solvents that are environmentally and human-biologically less harmful, easily and affordably obtainable.•The study presents a method for determining the water number of surfactants.•The method is straightforward to execute and free from harmful solvents.•By improving the method, we enhanced the reliability of the examination.

Blind modal identification for decentralized sensor network by modified sparse component analysis in frequency-domain subspace

It is practical to develop a modal identification method using a decentralized sensor network for field tests. Sparse component analysis (SCA) is a potential method in the framework of blind source separation to overcome the difficulty of using limited sensors. Nevertheless, it is still challenging for SCA to identify a larger number of modes than the number of measurements using the decentralized sensor network. This is because the partial mode shapes may be similar. It is convenient to perform SCA in frequency-domain subspaces to improve SCA further for decentralized sensor implementation; this is owing to the distinguishability of different partial mode shapes. In this study, a modal identification method applied to a largely underdetermined case caused by a decentralized sensor network is proposed by modifying SCA by automatic segmentation of frequency-domain subspaces. First, a method for determining the segmenting point is developed by identifying the valleys of the energy fluctuation spectrum using the scale-space peak detection method. Second, single-mode-points in the time–frequency plane are detected to facilitate mode shape estimation in the frequency-domain subspaces. Third, density peak clustering with the clustering number determination method is developed to estimate mode shapes, particularly for closely spaced modes. Finally, the modal frequencies and damping ratios are identified through the inverse operator in the frequency-domain subspaces and the curve fitting of the expected instant spectrum. The proposed method is verified by a 10 degree-of-freedom system, a structure with close modes, and an actual cable-stayed bridge. The investigations verified the effectiveness of the proposed method for decentralized sensor networks and practical applications.

Dynamic evaluation of regional water resources carrying capacity based on set pair analysis and partial connection number

Abstract In order to quantitatively evaluate and analyze regional water resources carrying capacity (WRCC) and to describe the micro motion between connection number components, a more applicable evaluation model was sought. Firstly, an evaluation index system and grade standards for a regional WRCC were constructed. Then, a method for determining the connection number was proposed, which considered the micro motion between the connection number components in the system structure. Finally, an evaluation model based on set pair analysis (SPA) and partial connection number (PCN) that used subtraction set pair potential (SPP) to identify vulnerability factors was built, and identification results were compared with the total partial connection number (TPCN). The model was applied to Huaibei City, Anhui Province, China. The results showed that: the WRCC grade value was between 2 and 3 which was poor; the support and regulation subsystem grade value was between 2 and 3, and the pressure subsystem grade value was between 1 and 2. SPP identified that the support force and regulation force subsystem were the vulnerable subsystems. Eight indexes, including water resources per capita, rate of ecological water consumption and density of population, were the main indicators causing the poor WRCC, which were in good agreement with the local measured data. In addition, the SPP and TPCN were compared to further verify rationality of the connection number determination method and reliability of the identification results. The model established in this paper has strong applicability and can also be used for the dynamic evaluation of other resources, including the environment and ecological carrying capacity. The results in this study provide a scientific basis for water resources management and decision-making.

Removal of Pb(II) ions from Tigris river wastewater in Mosul city by using modified commercial activated carbon

Background: The water pollution of Tigris river is considered the main increasing problem in Mosul city, Iraq. The divalent lead ions are direct or indirect toxic heavy metals ions contaminant confirmed as non-biodegradables and have a long half-life due to corrosions and sedimentation of these metal ions in storm sewer trunk mains, the critical issue is eliminating these heavy metal ions by treating wastewater via commercial activated carbon (CAC), which is the most effective used adsorbent in the adsorption process. Aim: This study aimed to eliminate divalent lead ions by treating wastewater using commercial activated carbon (CAC). Methodology: The surface of commercial activated carbon (CAC) was modified by using concentrated nitric acid. For this purpose, nitric acid in different concentrations (2, 4, 6, 8, and 10 M) and different temperatures (25, 50, 75, and 100( °C were used. Results and Discussion: The best results were observed at 50 °C in which it was used as a standard temperature. A 10 M nitric acid concentration was noticed as the best one. It could be observed that the high pore volume observed in modified activated carbon samples (estimated as the highest adsorption capacity towards iodine, using iodine number determination method) was (707.2 mg/g). This result was supported by methylene blue (190 mg/g). The modified activated carbon (MAC) at the chosen acid concentration was a useful filter to remove the methylene blue organic dye. The modified activated carbon (MAC) was used to adsorbed Pb2+ ions from the Mosul Tigris river wastewaters, the percentage of mean changed activated carbon (MAC) surface adsorption removal efficiency of divalent lead ions were increased by 219% compared with the commercial activated carbon (CAC). 1.1.1. Conclusions: Using the methods for iodine number, ash content, methylene blue and density determinations, it was proven that the excellent sorption properties, strong microporous structure, large pore volume, surface of the acidic character, and porosity are the most critical chemical characterization parameters

Determination of average times for Brillouin optical time domain analysis sensor denoising by non-local means filtering

Integration of signal average and image restoration can improve the performance of distributed optical fiber sensors. Here we illustrate the denoising behavior of non-local means filtering (NLM) affected by number of average. On the one hand, the signal average can effectively remove the high-frequency noise but be time-consuming; on the other hand, the NLM can accelerate decent in noise but is dependent on level of noise contained in raw sensing image. To best of our knowledge, this is the first time to apply NLM to conventional Brillouin optical time domain analysis sensor (BOTDA) with theoretically spatial resolution of 10 ns. Moreover, we propose an optimal averaging number determination method for further denoising by NLM to achieve trade-off between accuracy and average times. The results indicated that the optimal-times for BOTDA configured 10 ns and 10km fiber-loop is 13 with Brillouin frequency shift uncertainty of 0.85MHz. The proposed method has potential to apply in engineering applications and commercialized software for BOTDA denoising by image restoration.

Comparison of Multiple Methods for Determination of FCGR3A/B Genomic Copy Numbers in HapMap Asian Populations with Two Public Databases.

Low FCGR3 copy numbers (CNs) has been associated with susceptibility to several systemic autoimmune diseases. However, inconsistent associations were reported and errors caused by shaky methods were suggested to be the major causes. In large scale case control association studies, robust copy number determination method is thus warranted, which was the main focus of the current study. In the present study, FCGR3 CNs of 90 HapMap Asians were firstly checked using four assays including paralog ratio test combined with restriction enzyme digest variant ratio (PRT-REDVR), real-time quantitative (qPCR) using TaqMan assay, real-time qPCR using SYBR Green dye and short tenden repeat (STR). To improve the comparison precision reproductively, the results were compared with those from recently released sequencing data from 1000 genomes project as well as whole-genome tiling BAC array data. The tendencies of inconsistent samples by these methods were also characterized. Refined in-home TaqMan qPCR assay showed the highest correlation with array-CGH results (r = 0.726, p < 0.001) and the highest concordant rate with 1000 genome sequencing data (FCGR3A 91.76%, FCGR3B 85.88%, and FCGR3 81.18%). For samples with copy number variations, comprehensive analysis of multiple methods was required in order to improve detection accuracy. All these method were prone to detect copy number to be higher than that from direct sequencing. All the four PCR based CN determination methods (qPCR using TaqMan probes or SYBR Green, PRT, STR) were prone to higher estimation errors and thus may lead to artificial associations in large-scale case-control association studies. But different to previous reports, we observed that properly refined TaqMan qPCR assay was not inferior to or even more accurate than PRT when using sequencing data as the reference.

Development of the original method for determination of diclofenac sodium in different drug dosage forms

There are a number of methods for determination of diclofenac sodium in medicines; however, they all differ by analytical methods involved depending on the drug dosage form. The aim of the study was to develop the universal HPLC-method for determination of diclofenac sodium, which would be suitable for quantitative determination of this active pharmaceutical ingredient (API) in various dosage forms. In our study a chromatograph 2695 with a photodiode array detector 2996 (Waters Corp., USA) and the column containing the C18 phase with the particle size of 5 mm, ER-182 balances (AND company, Japan), measuring glassware of class A were used. Validation of the method has been conducted in accordance with the requirements of the State Pharmacopoeia of Ukraine (SPhU). The HPLC-method for determination of diclofenac sodium in different drug dosage forms and UPLCvariant of this method for conducting rapid measurements have been developed. Validation of the methods proposed has been conducted, their suitability for determining diclofenac sodium in different drug dosage forms, as well as the insignificant effect of the sample preparation on the analysis results have been proven. The analysis of various medicines has been performed; the possibility of using the methods developed for the analysis of existing medicines based on diclofenac sodium has been proven.

Quantification of nanomaterial bioconjugation based on electrophoretic mobility shift.

Electrophoretic mobility shift assay (EMSA) is a well-established technique to monitor interactions between biomolecules particularly DNA and proteins. Even though numerous variations of this method have been presented, challenges in the form of detection sensitivity and/or variations in the stability of the formed complex still remain. With advances in the area of nanomaterials improvements in EMSA have been also suggested. Recently, Zhang and Wang (Electrophoresis 2015, 36, 1011-1015) presented electrophoretic mobility shift method for determination of number of DNA molecules conjugated to quantum dots (QDs), which was further utilized for calculation of enzymatic activity, sequence specific DNA detection, and neutral molecule quantification.

A new method for 3D designing of complementary exploration drilling layout based on ore value and objective functions

In the earth sciences modeling, a great deal of uncertainty is associated with interpretation of subsurface data. Drilling borehole is one of the best tools for subsurface exploration and data gathering. Uncertainty of ore reserve modeling can be reduced by intelligent design of complementary drillings between the primary boreholes. This paper introduces a new method for determination of number, as well as directional and dimensional properties of such additional drillings based on ore value and objective functions, by applying an interval threshold concept. The proposed method is verified in Choghart iron deposit, central Iran. After calculations of descriptive statistical parameters, followed by geostatistical stages such as variography, anisotropy modeling, and kriging estimation of Fe (iron) and P (phosphorus) variables are performed. Thresholds commonly separate data sets into two classes by a sharp boundary and assigning samples to these indicators involve uncertainty. Instead of point threshold, an interval threshold with fuzzy membership function was implemented. Interval threshold is applied to determine indicators by considering Fe and P grades of kriging (soft) outputs. On the basis of one threshold for Fe and two thresholds for P, six classes of combination indicators of Fe and P were generated. Indicator-weighted average (IWA) and class membership degrees (CMD) for each block (sample) were measured by interval thresholds. Fe and P preference functions were defined for modeling of positive, neutral, and negative values (behaviors) in different ranges of grades. Ore value function is defined as a function of CMD, preference degrees, and weight factors for Fe and P grades. Finally, multiplicative equation of the ore value function and kriging variance is computed as objective function. Given large amounts of the objective function, four vertical and a single-directional drilling along with approximate length, priority of locations, azimuth, and dip angles of drillings are the final output of this method.

Electrical Resistivity Measurements of Layer Number Determined Multilayer Graphene Wiring for Future Large Scale Integrated Circuit Interconnects

To investigate the feasibility of nanocarbon interconnects for future LSIs, the electrical resistance of exfoliated multilayer graphene (MLG) wirings has been studied with accurate measurements of the number of layers. We employed transmission electron microscopy (TEM) as an exact number determination method, atomic force microscopy (AFM) as a simple method, and an extended optical contrast method as an easy distinction method, which we proposed for determining the number of layers. The sheet resistance of MLG wirings, including TEM determined 3-, 54-, and 341-layer MLGs, has been measured using the four-probe method and the layer number dependence of sheet resistance was discussed on the basis of a ladder circuit model simulation. It is shown that the dependence agrees well with the simulations, suggesting parallel conduction in MLG wirings, even if the probe electrodes are deposited just on the top layer of MLG.

Quasi-Static Step Number Determination Method of a Quadruped in Step Crossing

Legged living creatures can move on any kinds of terrain with good adaptability. They read the terrain conditions and repeat inherent or acquired obstacle crossing sequences, which can be imitated mechanically for the design of a Quadruped. For the prototype model and the step, four corner distances are determined according to the desired body angle and the continuous locomotion sequences are determined. Also, the requirements to satisfy three conditions for step-down are introduced, which makes it possible to determine the exact number of steps in the second phase of step-down. Since step-up is the reverse of step-down, all the governing parameters are the same and the locomotion sequences of step-down are also the reverse of step-up, except for the case of walking-down by gravity. The dimensions of a suggested quadruped are used to calculate the crossing performance for the purpose of comparison.

New fast method for determination of number of UHMWPE wear particles

Ultra-high molecular weight polyethylene (UHMWPE) wear particles are the major cause of total joint replacement (TJR) failures because the wear particles, released from TJR's, cause bone loosening. To simplify the study of the relationship between numbers of particles at various locations around TJR's and extent of bone loosening at these locations, the authors of this work tried to develop a new method for easy and fast determination of number of wear particles. The method, called LSC (Light Scattering with Calibration spheres), is based on light scattering of a suspension of wear particles and calibration spheres, and yields relative numbers of particles. A modified LSC method, called LSCm, requires one additional experiment, a gravimetric analysis of a mixture of all studied samples, to determine absolute numbers of wear particles. LSC and LSCm methods are easy and fast, which make them suitable for processing and comparing high number of samples.

High-throughput transgene copy number estimation by competitive PCR

Transgene copy number affects the level and stability of gene expression. Therefore, it is important to determine the copy number of each transgenic line. Polymerase chain reaction (PCR) is widely employed to quantify amounts of target sequences. Although PCR is not inherently quantitative, various means of overcoming this limitation have been devised. Recent real-time PCR methods are rapid; however, they typically lack a suitable internal standard, limit the size of the target sequence, and require expensive specialized equipment. Competitive PCR techniques avoid these problems, but traditional competitive methods are time consuming. Here we apply mathematical modeling to create a rapid, simple, and inexpensive copy number determination method that retains the robustness of competitive PCR.

Assessment of the height equivalent to a theoretical plate in liquid chromatography

A number of methods for determination of the height equivalent to a theoretical plate particularly in reversed-phase liquid chromatography, are discussed. The methods are based on measurements of the peak width at half height, points of inflection, Gaussian curve fit, moments and on the exponentially modified Gaussian function. Data from 180 chromatograms obtained using the same column, together with additional data from other columns, were computer processed and applied to the different methods, the Gaussian curve fit and peak width at half height being found to be the methods of greatest merit. A significant deviation from earlier published curve forms of the Van Deemter plot is presented.