In this study, the physical and mechanical behaviors of geopolymers prepared by using different amounts of silica fume and calcium hydroxide as binding materials, acidic pumice as fine aggregate and waste aluminium particles as air-entraining agent were investigated. Test results showed that binder types, amount of binders and alkali activator (sodium hydroxide) significantly affected the physical and mechanical behavior of geopolymer specimens. Bulk density, compressive and flexural strength decreased with the higher alkali activator content. Addition of waste aluminium particles led to decrease in bulk density and strength due to the some extent of entrained air. In the case of same alkali activator content, compressive and flexural strength increased with increase in silica fume and calcium hydroxide up to a certain level. 相似文献
Dielectric constant (DC) and dielectric loss factor (DLF) are the two principal parameters that determine the coupling and
distribution of electromagnetic energy during radiofrequency and microwave processing. In this study, chemometric methods
[classical least square (CLS), principle component regression (PCR), partial least square (PLS), and artificial neural networks
(ANN)] were investigated for estimation of DC and DLF values of cakes by using porosity, moisture content and main formulation
components, fat content, emulsifier type (Purawave™, Lecigran™), and fat replacer type (maltodextrin, Simplesse). Chemometric
methods were calibrated firstly using training data set, and then they were tested using test data set to determine estimation
capability of the method. Although statistical methods (CLS, PCR and PLS) were not successful for estimation of DC and DLF
values, ANN estimated the dielectric properties accurately (R2, 0.940 for DC and 0.953 for DLF). The variation of DC and DLF of the cakes when the porosity value, moisture content, and
formulation components were changed were also visualized using the data predicted by trained network. 相似文献
The acceptance and widespread use of the Android operating system drew the attention of both legitimate developers and malware authors, which resulted in a significant number of benign and malicious applications available on various online markets. Since the signature-based methods fall short for detecting malicious software effectively considering the vast number of applications, machine learning techniques in this field have also become widespread. In this context, stating the acquired accuracy values in the contingency tables in malware detection studies has become a popular and efficient method and enabled researchers to evaluate their methodologies comparatively. In this study, we wanted to investigate and emphasize the factors that may affect the accuracy values of the models managed by researchers, particularly the disassembly method and the input data characteristics. Firstly, we developed a model that tackles the malware detection problem from a Natural Language Processing (NLP) perspective using Long Short-Term Memory (LSTM). Then, we experimented with different base units (instruction, basic block, method, and class) and representations of source code obtained from three commonly used disassembling tools (JEB, IDA, and Apktool) and examined the results. Our findings exhibit that the disassembly method and different input representations affect the model results. More specifically, the datasets collected by the Apktool achieved better results compared to the other two disassemblers.
The bacterial strain Bacillus sp. ATS-2 isolated from Pb(II) polluted soil was immobilized with a silica matrix and Pb(II) biosorption properties of immobilized biosorbent were examined. Optimum biosorption conditions were investigated in the fixed bed column with the variation in the parameters of pH, bed length, flow rate and influent concentration. The Pb(II) biosorption equilibrium was attained within 60 min and the maximum biosorption yield for silica gel immobilized Bacillus sp. ATS-2 was determined as 91.73% at pH 4.0. The higher biosorption yields were observed at flow rates of 60 and 180 ml h(-1). The optimum bed length for the column was found as 10 cm. Data obtained from batch studies were evaluated by Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherm models. The maximum monolayer capacity of Bacillus sp. ATS-2 for Pb(II) was 2.36 x 10(-5) mol g(-1). The involvement of the functional groups on the surface of immobilized cells in biosorption process was also evaluated by FTIR spectral analysis. 相似文献
The construction of nanoporous membranes is of great technological importance for various applications, including catalyst supports, filters for biomolecule purification, environmental remediation and seawater desalination. A major challenge is the scalable fabrication of membranes with the desirable combination of good thermal stability, high selectivity and excellent recyclability. Here we present a self-assembly method for constructing thermally stable, free-standing nanowire membranes that exhibit controlled wetting behaviour ranging from superhydrophilic to superhydrophobic. These membranes can selectively absorb oils up to 20 times the material's weight in preference to water, through a combination of superhydrophobicity and capillary action. Moreover, the nanowires that form the membrane structure can be re-suspended in solutions and subsequently re-form the original paper-like morphology over many cycles. Our results suggest an innovative material that should find practical applications in the removal of organics, particularly in the field of oil spill cleanup. 相似文献
The rapid development of molecular biology is creating a pressing need for arrays of biomolecules that are able to detect smaller and smaller volumes of analytes. This goal can be achieved by shrinking the average size and spacing of the arrays' constituent features. While bioarrays with dot size and spacing on the nanometer scale have been successfully fabricated via scanning probe microscopy-based techniques, such fabrication methods are serial in nature and consequently slow and expensive. Additionally, the development of truly small arrays able to analyze scarce volumes of liquids is hindered by the present use of optical detection, which sets the minimum dot spacing on the order of roughly half the excitation wavelength. Here, we show that supramolecular nanostamping, a recently introduced truly parallel method for the stamping of DNA features, can efficiently reproduce DNA arrays with features as small as 14 +/- 2 nm spaced 77 +/- 10 nm. Moreover, we demonstrate that hybridization of these nanoarrays can be detected using atomic force microscopy in a simple and scaleable way that additionally does not require labeling of the DNA strands. 相似文献
In this study, the efficacy of electro activated water (EAW) and its mechanism on Escherichia coli and Enterococcus faecalis were investigated. The effects of different operating parameters of EAW on inactivation of bacteria were evaluated by response surface methodology (RSM). The interaction of free chlorine concentration and treatment time at 25 °C had a synergetic effect on E. coli and E. faecalis inactivation. The increase in crystal violet uptake showed the deterioration of cell membrane permeability. The release of 260 nm absorbing materials from both bacteria increased after EAW treatment. Protein degeneration increased with deformation of E. coli and E. faecalis cell membranes, which in turn was followed by the release of proteins together with other intracellular components such as DNA, RNA, potassium, and phosphate.
Practical applications
An electrode module was setup to produce EAW from a mixture of salt and tap water. Freshly prepared EAW was added to the bacterial pellets, mixing thoroughly and immediately initiating a timer. The mixtures were set at different treatment times. The effects of three operating parameters (treatment time, free chlorine concentration (FCC) and temperature) on bacteria inactivation were investigated using Response surface methodology. Crystal violet uptake assay, 260 nm release study and FT‐IR spectroscopy analysis were conducted to determine the mechanism of action of EAW. 相似文献