Determination of kojic acid using carbon paste electrode modified by [Fe(HL)2Cl2] nano-complex and ionic liquid

A new mononuclear Fe(II) (1) complex with the formula [Fe(HL)2Cl2] (HL= N-(2-hydroxy-1-naphthylidene)-2-methyl aniline) was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), UV–Vis and elemental analysis. The spectroscopy analyses revealed the two Schiff base ligands via oxygen and nitrogen atoms and two chloride atoms create an octahedral geometry. The nano-size of [Fe(HL)2Cl2] complex (2) was synthesized by the sonochemical process. Characterization of nano-complex (2) was carried out via X-ray powder diffraction (XRD), scanning electron microscopy (SEM), UV-Vis, FT-IR spectroscopy. The nano-complex (2) average size synthesized via the sono­che­mical method was approximately 52 nm. In this work, a simple sensor based on a carbon paste electrode modified with [Fe(HL)2Cl2] nano-complex and the ionic liquid - IL (1-Butyl-3-methylimidazolium hexafluorophosphate) was developed ([Fe(HL)2Cl2] nano-complex-IL/CPE) for convenient and fast electrochemical detection of kojic acid. The modified electrode considerably improves voltammetric sensitivity toward kojic acid compared to the bare electrode. Experimental conditions influencing the analytical performance of the modified electrode were optimized. Under optimal conditions, the oxidation peak current was proportional to kojic acid concentration in the range from 0.3 to 237.0 μM with a detection limit of 0.09±0.001 μM. The [Fe(HL)2Cl2] nano-complex-IL/CPE sensor was successfully applied for the highly sensitive determination of kojic acid in real samples with satisfactory results

Electrochemical sensor for determination of butylated hydroxyanisole in real samples using glassy carbon electrode modified by [Co(HL)2Cl2] nano-complex

A new mononuclear Co(II) complex with the formula [Co(HL)2Cl2] (1) (HL= N-(2-hydroxy-1-naphthylidene)-2-methyl aniline) has been synthesized and characterized by Fourier transform infrared spectroscopy, UV–Vis, elemental analysis and single crystal X-ray structure analysis. Single crystals of the complex [Co(HL)2Cl2] (1) were obtained through slow evaporation of an acetonitrile solution at room temperature. The crystal structure analysis revealed that the two Schiff base ligands create a tetrahedral geometry via oxygen atoms and two chloride atoms. The nano-size of [Co(HL)2Cl2] (2) have been synthesized by the sonochemical process. Characterization of nanoparticles (2) was carried out via X-ray powder diffraction (XRD), scanning electron microscopy (SEM), UV-Vis, and FT-IR spectroscopy. The average sample size synthesized via the sonochemical method was approximately 56 nm. In this work, a simple sensor based on a glassy carbon electrode modified with [Co(HL)2Cl2] nano-complex was developed ([Co(HL)2Cl2] nano-complex/GCE) for convenient and fast electrochemical detection of butylated hydroxyanisole (BHA). The modified electrode offers considerably improved voltammetric sensitivity toward BHA compared to the bare electrode. Applying linear differential pulse voltammetry, a good linear relationship of the oxidation peak current with respect to concentrations of BHA across the range of 0.5–150 μM and a detection limit of 0.12 μM was achieved. The [Co(HL)2Cl2] nano-complex/GCE sensor was applied to the determination of BHA in real samples successfully

Plant discrimination by Support Vector Machine classifier based on spectral reflectance

Support Vector Machine (SVM) algorithms are developed for weed-crop discrimination and their accuracies are compared with a conventional data-aggregation method based on the evaluation of discrete Normalised Difference Vegetation Indices (NDVIs) at two different wavelengths. A testbed is especially built to collect the spectral reflectance properties of corn (as a crop) and silver beet (as a weed) at 635 nm, 685 nm, and 785 nm, at a speed of 7.2 km/h. Results show that the use of the Gaussian-kernel SVM method, in conjunction with either raw reflected intensities or NDVI values as inputs, provides better discrimination accuracy than that attained using the discrete NDVI-based aggregation algorithm. Experimental results carried out in laboratory conditions demonstrate that the developed Gaussian SVM algorithms can classify corn and silver beet with corn/silver-beet discrimination accuracies of 97%, whereas the maximum accuracy attained using the conventional NDVI-based method does not exceed 70%

Surface Electromyography Feature Extraction Based on Wavelet Transform

Considering the vast variety of EMG signal applications such as rehabilitation of people suffering from some mobility limitations, scientists have done much research on EMG control system. In this regard, feature extraction of EMG signal has been highly valued as a significant technique to extract the desired information of EMG signal and remove unnecessary parts. In this study, Wavelet Transform (WT) has been applied as the main technique to extract Surface EMG (SEMG) features because WT is consistent with the nature of EMG as a nonstationary signal. Furthermore, two evaluation criteria, namely, RES index (the ratio of a Euclidean distance to a standard deviation) and scatter plot are recruited to investigate the efficiency of wavelet feature extraction. The results illustrated an improvement in class separability of hand movements in feature space. Accordingly, it has been shown that only the SEMG features extracted from first and second level of WT decomposition by second order of Daubechies family (db2) yielded the best class separability

Bayesian Analysis of Doubly Inflated Poisson Regression for Correlated Count Data: Application to DMFT Data

Outcome variables in clinical studies sometimes include count data with inflation in two points (usually zero and k (k>0)). Doubly inflated models can be adopted for modeling these types of data. In statistical modeling, the association among subjects due to longitudinal or cluster study designs is considered by random effects models. In this article, we proposed a doubly inflated random effects model using the Bayesian approach for correlated count data with inflation in two values, and compared this model with Bayesian zero-inflated Poisson and Bayesian Poisson models. The parameters’ estimates by these models were obtained by Markov Chain Monte Carlo method using OpenBUGS software. Bayesian models were compared using the deviance information criterion. To this end, we utilized the total number of decayed, missed, and filled teeth of 12-year-old children and also conducted a simulation study.  Results of real data and the simulation study revealed that the proposed model is fitted better than previous models.&nbsp

Thermal peformance of miniature loop heat pipe operating under different heating modes

In the new generation microprocessors, it is observed that the power density over the active surface can vary from uniform to non uniform modes depending on the clock speed and the processing load on the chipset. The latter mode of operation can result in hot spots on the microprocessors that can result in the increase of the local temperature above the permissible limit and ultimately in the failure of the electronic device. In order to propose a solution for this problem a miniature loop heat pipe (mLHP) with the flat disk shaped evaporator, 30 mm in diameter and 10 mm thick, was developed. The proposed mLHP was tested under uniformly as well as non-uniformly heating mode. In the uniform heating, the entire active area of the evaporator was heated while in the non-uniform mode only 14% of the evaporator active area was heated locally. The thermal performance of the mLHP under these heating modes was compared on the basis of the evaporator wall temperature and thermal resistance between different loop components. The results of the experiment help to classify mLHP as the viable thermal solution for the cooling of microprocessors with local hot spots and non-uniform heating pattern

Global Dam‐Driven Changes to Riverine N:P:Si Ratios Delivered to the Coastal Ocean

River damming alters nutrient fluxes along the land-ocean aquatic continuum as a result of biogeochemical processes in reservoirs. Both the changes in riverine nutrient fluxes and nutrient ratios impact ecosystem functioning of receiving water bodies. We utilize spatially distributed mechanistic models of nitrogen (N), phosphorus (P), and silicon (Si) cycling in reservoirs to quantify changes in nutrient stoichiometry of river discharge to coastal waters. The results demonstrate that the growing number of dams decouples the riverine fluxes of N, P, and Si. Worldwide, preferential removal of P over N in reservoirs increases N:P ratios delivered to the ocean, raising the potential for P limitation of coastal productivity. By midcentury, more than half of the rivers discharging to the coastal zone will experience a higher removal of reactive Si relative to reactive P and total N, in response to the rapid pace at which new hydroelectric dams are being built

Warm perineal compresses during the second stage of labor for reducing perineal trauma: A meta-analysis

OBJECTIVE: Perineal trauma may have a negative impact on women's lives as it has been associated with perineal pain, urinary incontinence and sexual dysfunction. The aim of this systematic review and meta-analysis of randomized controlled trials was to evaluate the effectiveness of warm compresses during the second stage of labor in reducing perineal trauma. METHODS: Electronic databases were searched from inception of each database to May 2019. Inclusion criteria were randomized trials comparing warm compresses (i.e. intervention group) with no warm compresses (i.e. control group) during the second stage of labor. Types of participants included pregnant women planning to have a spontaneous vaginal birth at term with a singleton in a cephalic presentation. The primary outcome was the incidence of intact perineum. Meta-analysis was performed using the Cochrane Collaboration methodology with results being reported as relative risk (RR) with 95% confidence interval (CI). RESULTS: Seven trials, including 2103 participants, were included in this meta-analysis. Women assigned to the intervention group received warm compresses made from clean washcloths or perineal pads immersed in warm tap water. These were held against the woman's perineum during and in between pushes in second stage. Warm compresses usually started when the baby's head began to distend the perineum or when there was active fetal descent in the second stage of labor. We found a higher rate of intact perineum in the intervention group compared to the control group (22.4% vs 15.4%; RR 1.46, 95% CI 1.22 to 1.74); a lower rate of third degree tears (1.9% vs 5.0%; RR 0.38, 95% CI 0.22 to 0.64), fourth degree tears (0.0% vs 0.9%; RR 0.11, 95% CI 0.01 to 0.86) third and fourth degree tears combined (1.9% vs 5.8%; RR 0.34, 95% CI 0.20 to 0.56) and episiotomy (10.4% vs 17.1%; RR 0.61, 95% CI 0.51 to 0.74). CONCLUSION: Warm compresses applied during the second stage of labor increase the incidence of intact perineum and lower the risk of episiotomy and severe perineal trauma