Simple Substitution Method Research Articles

Alternatif Karışım Yöntemleri ile F tipi Uçucu Külünün Çimento Harcı İçerisinde Kullanımı

In this study, it is focused on the use of fly ash, which is one of the industrial wastes, as a partial replacement of cement and fine aggregate in cement mortar. The feasibility of using fly ash as an alternative to cement and fine aggregates in concrete was determined by examining its effect on strength and durability properties in composites. Fly ash was used in the mixtures with three different mixing methods. This is the simple substitution method, addition method and partial substitution method. In each method, 10%, 20% and 30% of the material was removed by weight, and a total of ten different mixtures were prepared by adding fly ash instead. As a result of the experiments to determine the properties of the mixtures in the fresh and hardened state, the addition of fly ash to the mixtures improved the workability and freeze-thaw resistance. When we look at the results in terms of the methods used in the study, it was seen that the addition method gave better results in pressure, water absorption and capillary water absorption experiments than other methods, and according to the bending and cylinder splitting test results, higher values were obtained in the mixtures prepared with the partial substitution method compared to the other mixing methods.

Chemical Substitution‐Grown Lithium‐Magnesium Alloy as Ion Redistributor and Surface Protector for Highly Stable Lithium‐Metal Anode

AbstractAddressing lithium‐dendrite problem caused by uneven lithium (Li) plating/stripping is crucial for improving cycle‐life and safety of Li‐metal batteries. Here we describe a simple chemical substitution method of 2Li+Mg(PF6)2=Mg+2LiPF6 to construct a highly stable Li−Mg alloy on Li metal anode. The self‐grown Li−Mg alloy exhibits homogeneous β‐phase bulk structure with flat and dense surface morphology. Systematic studies reveal that the obtained Li−Mg film acts as ion redistributor and surface stabilizer to protect Li metal anode by its low strain, fast conductivity, superior lithophilicity and excellent stability. Compared to the bare Li metal, symmetric cells assembled using Li−Mg‐protected Li exhibit better cycling performance with lower charge‐discharge overpotential. Notably, this Li−Mg film demonstrates great potential for Li‐metal batteries, it can effectively suppress Li‐dendrite growth and work effectively in LiFePO4//Li and LiNi0.8Co0.1Mn0.1O2//Li cells. This work provides a simple and effective strategy to construct Li‐ion redistributor and surface protector to guard Li anodes operating in high‐energy Li batteries.

Exposure Assessment Techniques Applied to the Highly Censored Deepwater Horizon Gulf Oil Spill Personal Measurements.

The GuLF Long-term Follow-up Study (GuLF STUDY) is investigating potential adverse health effects of workers involved in the Deepwater Horizon (DWH) oil spill response and cleanup (OSRC). Over 93% of the 160 000 personal air measurements taken on OSRC workers were below the limit of detection (LOD), as reported by the analytic labs. At this high level of censoring, our ability to develop exposure estimates was limited. The primary objective here was to reduce the number of measurements below the labs' reported LODs to reflect the analytic methods' true LODs, thereby facilitating the use of a relatively unbiased and precise Bayesian method to develop exposure estimates for study exposure groups (EGs). The estimates informed a job-exposure matrix to characterize exposure of study participants. A second objective was to develop descriptive statistics for relevant EGs that did not meet the Bayesian criteria of sample size ≥5 and censoring ≤80% to achieve the aforementioned level of bias and precision. One of the analytic labs recalculated the measurements using the analytic method's LOD; the second lab provided raw analytical data, allowing us to recalculate the data values that fell between the originally reported LOD and the analytical method's LOD. We developed rules for developing Bayesian estimates for EGs with >80% censoring. The remaining EGs were 100% censored. An order-based statistical method (OBSM) was developed to estimate exposures that considered the number of measurements, geometric standard deviation, and average LOD of the censored samples for N ≥ 20. For N < 20, substitution of ½ of the LOD was assigned. Recalculation of the measurements lowered overall censoring from 93.2 to 60.5% and of the THC measurements, from 83.1 to 11.2%. A total of 71% of the EGs met the ≤15% relative bias and <65% imprecision goal. Another 15% had censoring >80% but enough non-censored measurements to apply Bayesian methods. We used the OBSM for 3% of the estimates and the simple substitution method for 11%. The methods presented here substantially reduced the degree of censoring in the dataset and increased the number of EGs meeting our Bayesian method's desired performance goal. The OBSM allowed for a systematic and consistent approach impacting only the lowest of the exposure estimates. This approach should be considered when dealing with highly censored datasets.

Facile Assembly of Carbazolyl-Derived Phosphine Ligands and Their Applications in Palladium-Catalyzed Sterically Hindered Arylation Processes

Phosphine ligands embodying a carbazolyl motif have been found to be successful in many palladium-catalyzed biaryl syntheses and direct C–H bond arylation processes. Here, a practical scaled-up synthesis of a series of carbazolyl-derived phosphine ligands, the PhenCarPhos series, is described. The original protocol for accessing the target ligand skeleton via aromatic C–N bond formation is limited by the use of a substoichiometric amount of copper salt and diamine catalysts, which both add cost and generate purification problems (significant amounts of side products and copper residues). In order to develop a more attractive and scalable synthetic pathway, a simple nucleophilic substitution method was attempted involving simple heating of 1-bromo-2-fluorobenzene, a carbazole derivative, and KOH in DMF without inert atmosphere protection. This route enables the large-scale synthesis of the desired ligand skeletons and minimizes the association of inseparable reduction side products. Particular examples of the use of these ligands in Pd-catalyzed sterically hindered arylation processes are also shown.

Preparation and Superhydrophobicity of Sn Thin Film Based Zn Substrate

In this paper, superhydrophobic Sn thin film based on Zn substrate was prepared by simple substitution method. X-ray diffraction analysis was used to determine the chemical composition and structural phase of the film, and the metallographic analyzer was employed to characterize the morphology of Sn film. The results showed that Sn metal and its corresponding Sn/Zn metal oxides formed a special micro/nano composite structure on the surface of Sn thin film. The morphology of Sn film is a composite structure consisting of micro-nano lines and micro-nano particles via the observation. In addition, the water contact angle was used to demonstrate the wettability of the film surface. Specifically, the water contact angle of Sn thin film based on Zn substrate exceeded 150°, which showed its superhydrophobic property. In detail, the influence of the surfactant to achieve a superhydrophobic surface was studied by changing the concentration of each component. By contrast, the best component content for superhydrophobic surface was including 0.02 M SnCl2, 0.01 M diluted sulfuric acid, and 0.05 M stearic acid solution, respectively. It should be mentioned that the superhydrophobicity of metal surface is a very important property of mechanical engineering and structural material, even an application on corrosion protection of metals.

Optimal LSBs-based quantum watermarking with lower distortion

Based on the NEQR representation of quantum grayscale images and binary images, the optimal LSBs-based quantum watermarking scheme is investigated in this paper, which embeds several binary images (watermark images) into a grayscale image (cover image). The size of the cover image and secret image are both assumed to be [Formula: see text]. Compared to quantum simple LSBs substitution method generating one stego-pixel, our presented quantum optimal LSBs-based method can generate three stego-pixel simultaneously first. Then one of them with lowest visual distortion is chosen as the final stego-pixel. To this end, first of all, the quantum circuits for a few basic quantum modules (i.e. Quantum Comparator, Parallel CNOT, Parallel Swap, ADDER MOD, Subtracter (SUB.ER) MOD and Absolute Value) are predefined. Following that, based on these simple modules, two composite quantum modules (i.e. the ADDER and SUB.ER MOD [Formula: see text] module and Choose final stego-pixel module) are further constructed. With the help of the basic and composite quantum modules, the integrated quantum circuit implementation of the optimal LSBs-based quantum watermark images embedding/extracting procedures are illustrated. Then, the experiment result are simulated under the classical computer software MATLAB 2014(b), which illustrates our presented optimal LSBs-based quantum watermarking methods are superior to the simple LSBs scheme in terms of PSNR and histogram graphs on the basis of visual effect, and the circuit’s complexity analysis also demonstrates our investigated scheme with a very low computational complexity. Finally, we analyze the security of quantum cryptography system, which verifies the quantum watermarking data can be securely transmitted to other legal normal users.

Effect of compositional data in the multivariate analysis of sterol concentrations in river sediments

In this paper, multivariate analysis of sterol concentrations detected in river sediment samples was performed. In order to remove co-dependence of values, concentrations of sterols were transformed using centered log-ratio (CLR) transformation. The main objective of the work was to point out the damaging effects of working in the wrong geometry on the principal component analysis (PCA) assessment of sterol pollution. In order to determine if the dimension lost have effect on the principal component analysis of sterols in sediments, we have performed the PCA using raw and log-ratio transformed sterol data. Additionally, two rounded zero replacement approaches, i.e. a simple-substitution method (DL/2, 0.55DL and DL/√2) and multiplicative replacement strategy (0.65 DL), were compared in order to determine if the replacement values have an effect on PCA results and conclusions. Relevant differences were noted by comparing the results of the principal component analysis obtained with raw data and log-ratio transformed sterol data. Only the PC loadings obtained from the CLR PCA allowed the clear distinction between human-sourced pollution and biogenic sources of sterols, whereas in the case of PCA with raw data loadings were all grouped almost in a single quadrant. For the small proportion of rounded zeros (not more than 10%), two different replacement approaches did not have any effect on transformed PCA output. The results presented in this work have shown that the effect of “closure” in the sterol data can be easily observed from the PCA biplot, and that it obstructs the evaluation of human contribution to pollution of river sediments. Therefore, prior to the PCA, sterol concentrations must be CLR transformed in order to perform a reliable assessment of the sewage contamination.

Time-dependent ROC analysis for censored biomarker data due to limit of detection

ABSTRACTReceiver operating characteristic (ROC) curve is a well-established analysis method to evaluate biomarker’s discrimination accuracy for binary outcomes. When the endpoint of interest is time to event outcome such as time to cancer recurrence, a biomarker’s time-varying discriminatory performance is often assessed by time-dependent ROC analysis. In practice, biomarkers are often imprecisely measured due to the limitation of assay sensitivity. The values below the limit of detection are not detectable. Ignorance of such data characteristic may lead to inaccurate estimation of marker’s potential discriminatory power. The objective of this article is to extend time-dependent ROC method to censored biomarker data by using parameter estimates from the Cox regression model that accommodates censored biomarker measurements. In the simulation study, the proposed methods are shown to outperform the simple substitution method that has been conventionally adopted for handling censored data. Application data are also given to illustrate our methods.

Multi-SNP Haplotype Analysis Methods for Association Analysis.

Haplotype analysis forms the basis of much of genetic association analysis using both related and unrelated individuals (we concentrate on unrelated). For example, haplotype analysis indirectly underlies the SNP imputation methods that are used for testing trait associations with known but unmeasured variants and for performing collaborative post-GWAS meta-analysis. This chapter is focused on the direct use of haplotypes in association testing. It reviews the rationale for haplotype-based association testing, discusses statistical issues related to haplotype uncertainty that affect the analysis, then gives practical guidance for testing haplotype-based associations with phenotype or outcome trait, first of candidate gene regions and then for the genome as a whole. Haplotypes are interesting for two reasons, first they may be in closer LD with a causal variant than any single measured SNP, and therefore may enhance the coverage value of the genotypes over single SNP analysis. Second, haplotypes may themselves be the causal variants of interest and some solid examples of this have appeared in the literature.This chapter discusses three possible approaches to incorporation of SNP haplotype analysis into generalized linear regression models: (1) a simple substitution method involving imputed haplotypes, (2) simultaneous maximum likelihood (ML) estimation of all parameters, including haplotype frequencies and regression parameters, and (3) a simplified approximation to full ML for case-control data.Examples of the various approaches for a haplotype analysis of a candidate gene are provided. We compare the behavior of the approximation-based methods and argue that in most instances the simpler methods hold up well in practice. We also describe the practical implementation of haplotype risk estimation genome-wide and discuss several shortcuts that can be used to speed up otherwise potentially very intensive computational requirements.

Onsite Substitution Synthesis of Ultrathin Ni Nanofilms Loading Ultrafine Pt Nanoparticles for Hydrogen Evolution.

Here, the ultrathin Ni nanofilms loading ultrafine Pt nanoparticles (Ni/Pt nanocomposites) were synthesized by a simple substitution method for the electrocatalysis of hydrogen evolution reaction (HER). First, the ultrathin Ni nanofilms were prepared by using NaBH4 to reduce Ni salt. Then the ultrafine Pt nanoparticles attached on the surface of the ultrathin Ni nanofilms through the onsite substitution reaction between PtCl6(2-) and Ni element. X-ray photoelectron spectroscopy (XPS) experiment confirmed that Ni in Ni/Pt nanocomposites exists in the form of Ni(OH)2. Transmission electro microscope (TEM) study showed that the ultrafine Pt nanoparticles were sufficiently dispersed and loaded at Ni ultrathin nanofilms. The obtained Ni/Pt nanocomposites exhibited superior activity of HER and good stability in acidic media. It obtained 10 and 100 mA/cm(2) with overpotential of only 36 and 115 mV, respectively. The stability experiment of 20,000 s gave nearly negligible current decrease. On the one hand, the ultrathin Ni nanofilms help to disperse and form the ultrafine Pt nanoparticles. On the other hand, the ultrathin Ni nanofilms help to load the ultrafine Pt nanoparticles as catalyst support and immobilize both of them onto the electrode surface because of the high surface free energy of ultrathin nanofilm and the leading high adsorption ability. In addition, Ni itself exhibited somewhat electrocatalytic activity of HER, which contributed to the whole HER electrocatalysis of Ni/Pt nanocomposites. The excellent electrocatalysis may lead to the decreased consumption of expensive Pt and open up new opportunities for applications in hydrogen energy.

Influência de dados censurados no cálculo da concentração média das variáveis de qualidade da água demanda química de oxigênio e fosfato

Um dos problemas comumente encontrado na análise estatística de dados provenientes do monitoramento da qualidade da água envolve os chamados dados censurados. Este estudo mostra como os valores calculados das concentração médias de amostras que contenham dados censurados são influenciadas pelo tamanho da amostra, percentual de dados censurados e método de cálculo. As concentrações médias foram calculadas com os métodos de substituição e maximum likelihood estimator (MLE) para amostras de demanda química de oxigênio e fosfato. O intervalo de confiança da média foi utilizado como métrica de comparação. Os resultados revelam que as concentrações médias calculadas com o método de substituição simples se posiciona fora do intervalo de confiança. Já o método MLE calcula valores aceitáveis, porém, a eficácia do método depende de um limite de elasticidade do nível de censura e do tamanho da amostra.

Highly water-soluble, porous, and biocompatible boron nitrides for anticancer drug delivery.

Developing materials for "Nano-vehicles" with clinically approved drugs encapsulated is envisaged to enhance drug therapeutic effects and reduce the adverse effects. However, design and preparation of the biomaterials that are porous, nontoxic, soluble, and stable in physiological solutions and could be easily functionalized for effective drug deliveries are still challenging. Here, we report an original and simple thermal substitution method to fabricate perfectly water-soluble and porous boron nitride (BN) materials featuring unprecedentedly high hydroxylation degrees. These hydroxylated BNs are biocompatible and can effectively load anticancer drugs (e.g., doxorubicin, DOX) up to contents three times exceeding their own weight. The same or even fewer drugs that are loaded on such BN carriers exhibit much higher potency for reducing the viability of LNCaP cancer cells than free drugs.

A New Steganography Technique Using Snake Scan Ordering Strategy

In this paper, we propose a new steganography technique using the snake scan ordering strategy. The proposed method hides the secret data that is an image in another image, known as the cover image. In this method, the pixel values of the secret image are organized in snake scan order, which are preprocessed to reduce their size. The resultant data is embedded into the Least Significant Bits (LSBs) of the pixels of the cover image. To minimize the error/distortion, the pixel values of the stegoimage are adjusted using Optimal Pixel Adjustment Process (OPAP). The performance of the proposed method is compared with that of the simple LSB substitution method, Chang et al. method, Thein & Lin method, and Chen method in terms of Peak Signal to Noise Ratio (PSNR). Our proposed method has higher PSNR in almost all cases.

Keggin type inorganic–organic hybrid material containing Mn(II) monosubstituted phosphotungstate and S-(+)-sec-butyl amine: Synthesis and characterization

A new inorganic–organic POM-based hybrid material comprising Keggin type mono manganese substituted phosphotungstate and enantiopure S-(+)-sec-butyl amine was synthesized in an aqueous media by simple ligand substitution method. The synthesized hybrid material was systematically characterized in solid as well as solution by various physicochemical techniques such as elemental analysis, TGA, UV–vis, FT-IR, ESR and multinuclear solution NMR ( 31P, 1H, 13C). The presence of chirality in the synthesized material was confirmed by CD spectroscopy and polarimeter. The above study reveals the attachment of S-(+)-sec-butyl amine to Keggin type mono manganese substituted phosphotungstate through N → Mn bond. It also indicates the retainment of Keggin unit and presence of chirality in the synthesized material. An attempt was made to use the synthesized material as a heterogeneous catalyst for carrying out aerobic asymmetric oxidation of styrene using molecular oxygen. The catalyst shows the potential of being used as a stable recyclable catalytic material after simple regeneration without significant loss in conversion.

Functionalization of Keggin type manganese substituted phosphotungstate by R-(−)-1-cyclohexylethylamine: Synthesis and characterization

A new chiral polyoxometalates based functionalized material comprising Keggin type mono manganese substituted phosphotungstate and enantiopure R-(−)-1-cyclohexylethylamine was synthesized in an aqueous media by simple ligand substitution method. The POM-based synthesized material was systematically characterized in solid as well as solution by various physicochemical techniques such as elemental analysis, TGA, UV–Vis, FT-IR, ESR and multinuclear solution NMR (31P, 1H, 13C). The presence of chirality in the synthesized material was confirmed by CD spectroscopy and polarimeter. The above study reveals the attachment of R-(−)-1-cyclohexylethylamine to Keggin type mono manganese substituted phosphotungstate through N→Mn dative bond. It also indicates the retainment of Keggin unit and chirality in the synthesized material.

Measurements of structure-borne sound from building service equipment by a substitution method—Round robin comparisons

A pilot project has been performed with a round robin comparison (inter-laboratory test), where a modified heavy-duty washing machine has been circulated for tests among 6 laboratories. The main goal of this pilot project was to find out whether a simple substitution method could be applied to estimate the structure-borne sound pressure level of some typical building service equipments. First, the vibration levels of a heavy low mobility test floor are measured when a machine with high internal mobility operates on this floor. Then, the vibration levels are measured at the same positions on the same floor when a standardized tapping machine (ISO 140-7) operates in the same positions as the test machine. The differences between the vibration level are then calculated. The difference may be used to compare the performance of different machines at one site or to estimate the sound pressure level in other buildings with heavy floors. In its simplest form, this can be made in the same way as for floorings, i.e., first calculating the normalized impact sound pressure level (EN 12354-2) and then subtracting the vibration level difference of the actual machine compared to the tapping machine. It remains to apply this method in the field and to compare estimated sound pressure levels with measured.

An Accurate Substitution Method for Analyzing Censored Data

When analyzing censored datasets, where one or more measurements are below the limit of detection (LOD), the maximum likelihood estimation (MLE) method is often considered the gold standard for estimating the GM and GSD of the underlying exposure profile. A new and relatively simple substitution method, called β -substitution, is presented and compared with the MLE method and the common substitution methods (LOD/2 and LOD/√2 substitution) when analyzing a left-censored dataset with either single or multiple censoring points. A computer program was used to generate censored exposure datasets for various combinations of true geometric standard deviation (1.2 to 4), percent censoring (1% to 50%), and sample size (5 to 19 and 20 to 100). Each method was used to estimate four parameters of the lognormal distribution: (1) the geometric mean, GM; (2) geometric standard deviation, GSD; (3) 95th percentile, and (4) Mean for the censored datasets. When estimating the GM and GSD, the bias and root mean square error (rMSE) for the β -substitution method closely matched those for the MLE method, differing by only a small amount, which decreased with increasing sample size. When estimating the Mean and 95th percentile the β -substitution method bias results closely matched or bettered those for the MLE method. In addition, the overall imprecision, as indicated by the rMSE, was similar to that of the MLE method when estimating the GM, GSD, 95th percentile, and Mean. The bias for the common substitution methods was highly variable, depending strongly on the range of GSD values. The β-substitution method produced results comparable to the MLE method and is considerably easier to calculate, making it an attractive alternative. In terms of bias it is clearly superior to the commonly used LOD/2 and LOD/√2 substitution methods. The rMSE results for the two substitution methods were often comparable to rMSE results for the MLE method, but the substitution methods were often considerably biased.

Information Hiding for G.711 Speech Based on Substitution of Least Significant Bits and Estimation of Tolerable Distortion

In this paper, we propose a novel data hiding technique for G.711-coded speech based on the LSB substitution method. The novel feature of the proposed method is that a low-bitrate encoder, G.726 ADPCM, is used as a reference for deciding how many bits can be embedded in a sample. Experiments showed that the method outperformed the simple LSB substitution method and the selective embedding method proposed by Aoki. We achieved 4-kbit/s embedding with almost no subjective degradation of speech quality, and 10kbit/s while maintaining good quality.

Rodność i umieralność na ziemiach polskich w kontekście teorii przejścia demograficznego

An attempt was made, in the article, to explain changes of people's fertility and mortality in ln 1918–1939 in context of the demographic transition as well as to determine transition phase periods. To set the beginning and the end of the "right" demographic transition, the non-linear regression (approximation by anti-logistic function in connection with the simple substitution method) was used in case of rigid fertility and mortality rates. According to the used methodology, it was found the "right" demographic transition (decrease in the mortality outdistanced decrease in the fertility) took place about 1885 on the Polish areas. Important differences in the level and dynamic of the fertility and mortality in different Poland's districts were indicated in the study too. On the basis of estimated models for each district it was stated, i.a. that the earliest (about 1871 and 1875) distinct collapse of the mortality trend took place in the west and south areas. From the time the "right" demographic transition was done on the areas. Moreover, on the basis of mortality tables from the twenty year period between two World Wars, it was recognized the value increase of the average life expectancy as well as a minor increase of the average years number of the reproduction age of the Poland's population (total: men and women).

To the distortion of the frequency of occurrence of characters in a simple substitution code

This paper considers coding messages by the simple substitution method, when a text is coded by using a substitution on the set of letters in the alphabet and transforming the result by applying an arithmetic function. In the initial text, different letters occur with different frequency (tables of relative frequencies of occurrence of letters in alphabets are given in, e.g., [3, 4]). We assume the frequency characteristic of the text under consideration to be close to table characteristics. Thus, the letter occurence frequency characteristics of the initial text coincide with those of the cipher, which is, as a rule, used for reconstructing the initial text. Therefore, changing the frequency characteristic of the cipher text impedes reconstructing the initial text. We distort frequency characteristics by using arithmetic functions. In [1], a method for distorting the frequency characteristics of a cipher text obtained by a simple substitution was suggested with used the quadratic root modulo some number as an arithmetic function. In this paper, we suggest a method for distorting the frequency of occurrence of letters in a cipher text obtained by a simple substitution based on the arithmetic function of raising to the second power modulo some number. The coding procedure is as follows. Suppose that the alphabet comprises 31 letters (such as the Russian alphabet in which the letters Â, fi and ¸,˙ are identified). We arrange the letters in this alphabet in the order of decreasing frequency of occurrence: (1) O , 0.090; (2) Â , 0.072; (3) ‡ , 0.062; (4) I , 0.062; …; (31) U , 0.002. We divide all residues modulo 31 into two classes, one of which consists of the 15 quadratic nonresidues and the other, of the 15 quadratic residues and zero. Suppose given an open text. (1) We code the text by the simple substitution method with the use of some substitution. (2) We order the letters in the cipher text by decreasing frequencies. After this, each of the first fifteen letters is assigned consecutive values of quadratic nonresidues modulo 31 according to their enumeration, and the remaining letters are assigned consecutive values of quadratic residues and 0. (3) Then, the letters of the cipher text that correspond to quadratic nonresidues according to (2) are coded by the squares of these nonresidues modulo 31, which belong to the interval [0, 30], and the letters corresponding to quadratic residues and zero are coded by these quadratic residues and zero themselves.