Search Results (6)

The surface roughness and wettability of wood are critical aspects to consider when producing laminated wood products with adhesive applications. This study aims to investigate the surface roughness and dynamic wettability of Jabon wood in the presence of melamine formaldehyde (MF)-based adhesives. Commercial MF adhesives (MF-0) and modified MF adhesives (MF-1) were applied to Jabon wood, which includes tangential (T), radial (R), and semi-radial (T/R) surfaces. The surface roughness of Jabon wood was assessed using a portable stylus-type profilometer. The low-bond axisymmetric drop shape analysis (LB-ADSA) method was employed to identify the contact angle (θ) of the MF-based adhesives on Jabon wood. The wettability was determined by evaluating the constant contact angle change rate (K value) using the Shi and Gardner (S/G) model. Dynamic mechanical analysis (DMA) was employed to investigate the viscoelastic characteristics of the interphase analysis of the wood and MF-based adhesives. The roughness level (Ra) of the Jabon board ranged from 5.62 to 6.94 µm, with the T/R having a higher level of roughness than the R and T. MF-0 exhibited a higher K value (0.262–0.331) than MF-1 (0.136–0.212), indicating that MF-0 wets the surface of Jabon wood more easily than MF-1. The wood–MF-0 interphase reached a maximum stiffness of 957 N/m at 123.0 °C, while the wood–MF-1 had a maximum stiffness of 2734 N/m at 110.5 °C. In addition, the wood–MF-0 had a maximum storage modulus of 12,650 MPa at a temperature of 128.9 °C, while the wood–MF-1 had a maximum storage modulus of 22,950 MPa at 113.5 °C. Full article

Atopic dermatitis (AD) has a negative influence on school attendance. We aimed to identify factors associated with school absenteeism in adolescents with AD. We used data from the 3rd to 11th annual Korean Youth Risk Behavior Web-based Survey completed from 2007 to 2015. Survey data were obtained from a stratified, multistage, clustered sample. Participants responded to the question “have you ever been diagnosed with AD?” Factors associated with AD-related school absenteeism (ADSA), which is defined as at least one school absence due to AD, were evaluated. Among the 141,899 subjects, the prevalence of AD increased (17.3% to 24.2%), while that of ADSA decreased (7.3% to 2.6%) from 2007 to 2015. Compared to adolescents without ADSA, those with ADSA were more likely to be male, middle school students, and have negative mental health states, including suicidality. In the multivariate logistic regression model, the association of sleep dissatisfaction and depression with ADSA was high (adjusted odds ratio, 6.12; 95% confidence intervals, 4.61–7.95; and 5.44; 5.23–5.67, respectively). The prevalence of ADSA has decreased despite an increase in the prevalence of AD in Korean adolescents; however, it is important for pediatricians to screen for factors associated with ADSA to improve school attendance in adolescents with AD. Full article

Surface tension is a meaningful parameter influencing boiling and condensation in macroscopic scale, in confined spaces, or for nanofluids; it further affects boiling with surfactants. Surface, or interfacial, tension is an important property in the research into increasing heat transfer, enhancing efficiency of photovoltaic systems, improving engine operation, or forming drugs or polymers. It is often determined using axisymmetric drop shape analysis based on the differential equations system formulated by Bashforth and Adams. The closed-form expression of the interface shape states the radii defining the bubbles are the negative numbers, which causes the temperature profile drops along the heat transfer direction, e.g., in the Wiśniewski formulas for the temperature in the vapor bubbles; moreover, the drop, or bubble, possesses only one main radius of curvature, which may reduce the number of the unknowns and equations in the Bashforth and Adams algorithm. An alternative method applying the closed-form expression for the droplet shape is validated for the water (denser) drop flowing down in octane (the lighter liquid); its spare equation is used for verifying the outcomes. Full article

Microsoft’s file system, NTFS, is the most utilised file system by Windows OS versions XP, Vista, 7, and 10. These systems have a little-known file attribute feature known as alternate data streams (ADS) which allows each file in the NTFS file system to have multiple data streams. ADS cannot be removed from the NTFS operating systems. However, the presence of ADS is not inevitably an issue in the OS or file system. Valid instances can be found on systems if scanned and might be valid. Windows OS does not have any in-built tools or applications to determine and remove the presence of existing ADS. This research presents ADSA or alternate data stream attack framework to exploit the alternate data streams and perform cyberattacks on Microsoft operating systems. This research discusses the process of creating and searching alternate data streams with a standard file and an executable binary. The authors executed ADS-hidden executable binary in the ADS. The authors present methods to detect and perform a clean-up by deleting the alternate data stream. Full article

Thanks to the advance of novel technologies, such as sensors and Internet of Things (IoT) technologies, big amounts of data are continuously gathered over time, resulting in a variety of time series. A semi-supervised anomaly detection framework, called Tri-CAD, for univariate time series is proposed in this paper. Based on the Pearson product-moment correlation coefficient and Dickey–Fuller test, time series are first categorized into three classes: (i) periodic, (ii) stationary, and (iii) non-periodic and non-stationary time series. Afterwards, different mechanisms using statistics, wavelet transform, and deep learning autoencoder concepts are applied to different classes of time series for detecting anomalies. The performance of the proposed Tri-CAD framework is evaluated by experiments using three Numenta anomaly benchmark (NAB) datasets. The performance of Tri-CAD is compared with those of related methods, such as STL, SARIMA, LSTM, LSTM with STL, and ADSaS. The comparison results show that Tri-CAD outperforms the others in terms of the precision, recall, and F₁-score. Full article

Arundo donax is a plant native to Asia and is considered an invader species in the Mediterranean region and many tropical zones in the world. These invader plants can be collected to produce a biomass, which can be converted to ash by combustion. The scope of the study is to assess the use of these ashes (Arundo donax straw ash [ADSA]) as supplementary cementing material due to their relatively high silica content. Electron microscopy studies on dried and calcined samples of different plant parts (cane, sheath leaf and leaf) were carried out. Some different cellular structures were identified in the spodogram (remaining skeleton after calcination). Major silica content was found in leaves and sheath leaves. The main element in all the ashes studied, together with oxygen, was potassium (22 to 46% depending on the part of the plant). Chloride content was also high (5–13%), which limits their use to non-steel reinforced concrete. The pozzolanic reactivity of ADSA was assessed in pastes by thermogravimetric analysis and in mortars with ordinary Portland cement based on compressive strength development. Excellent results were found in terms of reactivity. Full article