Search

Excessive fragmentary myoclonus (EFM) is a frequent finding in patients undergoing video-polysomnography (VPSG). We aimed to evaluate the potential effect of sleep-related breathing disorder's treatment with positive airway pressure (PAP) therapy on EFM. One hundred consecutive patients with EFM and sleep-related breathing disorder subsequently treated with PAP at the sleep lab of the Medical University of Innsbruck, Department of Neurology, Austria, were included. Each patient underwent two nights of VPSG: the first night without and the second night with PAP therapy. Fragmentary myoclonus was automatically scored with validated software, and fragmentary myoclonus index (FMI) and minutes of non-rapid eye movement (NREM) sleep with EFM (min NREM+EFM) were calculated. Under PAP therapy there was a significant decrease in the min NREM+EFM — 60.5 (9.5–161.8) at baseline vs. 37.5 (6.3–168.8) minutes under PAP, p = 0.025. No significant differences were observed for FMI between the two nights. Sleep variables, sleep diagnoses, comorbidities, and medication did not influence FMI or the min NREM+EFM. The initiation of PAP treatment led to a significant reduction of min NREM+EFM , but not of FMI. The results suggest that PAP therapy might influence the distribution of FM potentials. • First study evaluating effect of PAP on excessive fragmentary myoclonus (EFM). • PAP therapy significantly reduces minutes of NREM sleep with EFM. • No significant reduction of fragmentary myoclonus indices. • PAP therapy might have influence on the distribution of FM potentials. [ABSTRACT FROM AUTHOR]

The electrical and optical characteristics of pure and Al-doped zinc oxide (ZnO) nanoparticles were analyzed. The work function of these nanoparticles was investigated using Kelvin Probe Force Microscopy (KPFM). The work function of the Al-doped ZnO nanoparticles was found to be lower than that of undoped ZnO nanoparticles. Electrostatic Force Microscopy (EFM) was employed to map the distribution of charges and conductivity in both ZnO and Al -doped ZnO, revealing enhanced charge trapping and increased conductivity in the Al-doped ZnO nanoparticles compared to the undoped ones. XRD analysis verified that both pure ZnO and Al-doped ZnO nanoparticles exhibited a hexagonal wurtzite crystal structure. Additionally, Raman spectroscopy revealed new vibrational modes at 572 cm−1, which were attributed to E1 (LO) in Al-doped ZnO. UV–visible spectroscopy indicated that the band gap of Al -doped ZnO nanoparticles is wider than that of pure ZnO nanoparticles, Additionally, photoluminescence spectroscopy demonstrated a blue shift in the emission spectrum of the Al-doped ZnO nanoparticles, accompanied by a reduction in green emission defects.

Amaç: Kadınların doğum sürecinde uygulanan vajinal muayene ve elektronik fetal monitöre yönelik deneyimlerini ortaya koymaktır.Yöntem: Tanımlayıcı tipte olan araştırma İstanbul’da bulunan bir eğitim ve araştırma hastanesinin doğum kliniğinde yapılmıştır. Araştırmanın örneklemini Aralık 2021-Mart 2022 tarihleri arasında doğumhane biriminde normal vajinal yolla canlı doğum yapmış, araştırmaya katılmayı kabul eden 120 gönüllü kadın oluşturmuştur. Veriler, araştırmacılar tarafından literatür doğrultusunda hazırlanan “anket formu” ile toplanmıştır.Bulgular: Çalışmaya katılan gebelerin yarıdan fazlasının vajinal muayene sırasında rahatsızlık hissi ve korku duygusu yaşadığı görülmüştür. Bu duyguların nedeninin ise mahrem bölgelerini göstermek (%90) olduğu saptanmıştır. Kadınlar vajinal muayeneyi yapan sağlık personelinin cinsiyetinin erkek olmasının daha fazla rahatsızlık vereceğini (%78,3) belirtmişlerdir. Gebeler elektronik fetal monitöre yönelik doğuma yardımcı bir araç olduğunu (%77,5) ve bebeğe zarar vereceğini (%40,8) düşündüklerini belirtirlerken kadınların dörtte biri (%25) makineden gelen seslerin korkutucu olduğunu belirtmişlerdir.Sonuç: Gebelerin vajinal muayene ve elektronik fetal monitör uygulaması deneyimlerinin genelde olumsuz olduğu saptanmıştır. Gebelerin rahatsız olduğu durumlar dikkate alınarak vajinal muayene sadece gerekli durumlarda yapılmalıdır.

The inhibiting impact of ecofriendly 5-[4-(dimethylamino) benzylidene]-1,3-dimethylbarbituric acid in 1 M HCl on the corrosion for carbon steel has been examined via "weight loss (WL) method, potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM) tests". The attained outcomes exhibit that the investigated compound is excellent inhibitor and its inhibition efficiency (%IE) rises by raising concentration and decreases by raising the temperature. The adsorption of 5-arylidene barbituric acid on the surface of C-steel follows Langmuir isotherm. The adsorption process of the investigated compound is spontaneous and considered as of chemisorption and physisorption type. PP curves revealed that the 5-arylidene barbituric acid derivative is mixed-type inhibitor. Moreover, EIS results confirmed the adsorption of the investigated compound on C-steel surface via increasing on charge transfer resistance (R ct). The IE% of this inhibitor reached to 86.9% at concentration 21×10-6 M according to PP method. Finally, the experimental and theoretical results are in good harmony.

The inhibition efficiency derivative imidazole, 2-mercapto-5,5-diphenyl-3,5-dihydro-4 H-imidazol-4-one (AM0), against corrosion in a hydrochloric acid (HCl) environment was studied. The research focused on the compound's ability to adsorb onto mild steel surfaces. Various experimental techniques, including potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM), and impedance spectroscopy (EIS), were employed to analyze the inhibitory effects. Results showed that the effectiveness of AM0 increased with concentration, reaching an inhibitory efficiency of 95.1 %. Polarization studies revealed that the inhibitor displayed mixed-type behavior. The adsorption process was modeled using the Langmuir adsorption model. Surface characterization techniques such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), and X-ray photoelectron spectroscopy (XPS) were utilized to examine the inhibited corrosion surfaces. Theoretical calculations based on density functional theory (DFT) and density functional tight binding (DFTB) suggested that inhibitors with electron-accepting capabilities exhibited strong interactions with the iron surface, shedding light on specific bond formations that contribute to the stability and interaction dynamics at the molecular interface. This study provides valuable information on the corrosion inhibition potential of the new imidazole compound, offering important pointers for the development of effective corrosion inhibitors in acidic environments. [Display omitted] • AM0 shows high corrosion inhibition efficiency of up to 95.1% for mild steel in hydrochloric acid. • AM0 increases activation energy, indicating effective protective layer formation on the metal surface. • AM0 adsorption follows Langmuir isotherm, suggesting monolayer adsorption with a chemisorption mechanism. • Theoretical studies (DFT and MC simulations) confirm AM0's effectiveness as a corrosion inhibitor. [ABSTRACT FROM AUTHOR]

The exploration of hybrid composites holds great promise in the pursuit of synergistic energy-harvesting solutions, providing an efficient approach to tap into multiple energy sources. One striking example is the BTO (BaTiO 3)-polymer hybrid where its high dielectric constant and the piezo-/ferroelectricity are leveraged to improve the triboelectricity of the polymer-based triboelectric nanogenerator (TENG). Beyond this, the BTO also exhibits a photoactive nature, which, until now, has not been exploited to enhance triboelectricity. In this study, a facile method to exploit BTO's photoresponses in a BTO-polymer hybrid is reported, where surface states present in BTO nanoparticles enable visible spectrum absorption, and the interfaces are designed to facilitate charge spatial separation. Upon visible light illumination, surface charges are generated on the BTO-polymer hybrid, significantly enhancing the photo-induced charge electrification, which in turn boosts the TENG output. These findings demonstrate the possibility of simultaneously harvesting solar and mechanical energies in TENGs using ceramic-polymer hybrids. Additionally, the study employs multiple advanced Scanning Probe Microscopy (SPM) techniques to elucidate the roles of each component and interface in energy harvesting, shedding light on the functional material design. This work not only broadens the variety of energy sources for TENGs but also addresses the growing demand for sustainable and adaptable methods of power generation. [Display omitted] • Surface states and interface engineering work in tandem to harness visible light, inducing surface charge on a dynamic ceramic/polymer hybrid. • The light-induced surface charges on the BTO-polymer hybrid elevate TENG voltage by 118 % and current by 31.7 %. • BTO-polymer hybrid-based TENGs showcase the simultaneous capture of solar and mechanical energies. [ABSTRACT FROM AUTHOR]

In this study, mixed convection regarding nanofluid within the wavy lid-driven enclosure and a prominent heat source is investigated. A two-phase method is applied to the employed nanoliquid which leads to a non-homogeneous concentration field. The obtained governing equations are solved by the finite element technique. The effects of adding nanoparticles in base flow on velocity, temperature, and concentration field are investigated. Also, the effects of different geometric dimensions on heat transfer, such as heat source aspect ratio, wave number, and amplitude of wavy walls are investigated. The outcomes reveal that increasing the application of nanoparticles, wave number and amplitude of the wavy wall, and aspect ratio of heat source yields an improvement within the rate of heat transfer.

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Expired nizatidine drug (END) was studied as inhibitor for a-brass in 1M HCl utilizing weight loss (WL), and electrochemical methods namely, AC impedance (EIS), Potentiodynamic polarization (PP), and electrochemical frequency modulation (EFM) tests. The protection efficiency (%IE) was improved with raising in the dose of the expired nizatidine and decreases with raising the temperature. The (%IE) reaching maximum value 95 % at higher dose of expired nizatidine drug at 25°C. PP data indicated that nizatidine drug behaves like a mixed kind drug. The protection of a-brass corrosion by nizatidine can fit to the adsorption ability of nizatidine drug molecules onto the reactive sites of the a-brass surface. The adsorption of the drug follows Langmuir adsorption isotherm. The surface morphology of a-brass was investigated. The results obtained from different methods are in excellent agreement.

Four pyridine-pyrimidine derivatives, namely pyridine-2,6-diamine (PD), pyrimidine-2-amine (PA), 6-amino-3,4-dihydropyrimidine-2(1H)-thione (ADT) and ethyl (R)-6-(4-chlorophenyl)-2-mercapto-4-methyl-1,6-dihydropyrimidine-5-carboxylate (EMMD) are used as effective inhibitors for aluminum corrosion in 1 M HCl solution. The anti-corrosive potential of these heterocyclic compounds has been evaluated by electrochemical frequency modulation (EFM) method, The inhibition efficiency of these inhibitors was strongly associated to the concentration (10−7–10−3M) and the structure of the molecules; reached a maximum of 95.68% for EMMD at 10−3 M owing to more anchoring functional groups. The effect of temperature on the corrosion behaviour was assessed at solution temperature range 298–323 K. The four inhibitors adsorbed according to the Langmuir’s adsorption isotherm. Thermodynamic activation parameters for the dissolution process of aluminum in 1 M HCl and inhibited solutions were calculated and discussed. Surface analysis (SEM, EDX, and AFM) confirmed the formation of a protective layer adsorbed on the aluminum surface. In addition, theoretical studies by DFT and MD revealed the correlation between the molecular chemical structure of studied inhibitors and their inhibition efficiency. The adsorption mechanism is revealed by theoretical calculations.

• AMT and AMH of two Schiff bases were synthesized and confirmed successfully. • Polarisation investigations revealed that both inhibitors were mixed-type inhibitors. • According to adsorption studies, the inhibitors followed the Langmuir isotherm. • The experimental findings and theoretical computations were in agreement. The suitability of the two synthesized hydrazones namely N''-[(4-aminocoumarin-3-yl)methylidene]thiocarbonohydrazide (AMT), and 2-[(4-Aminocoumarin-3-yl)methylidene]hydrazinecarbodithioic acid (AMH) as corrosion inhibitors for N80 carbon steel (N80 CS) metal in acidic hydrochloric solution has been investigated at different concentrations of inhibitors (10–7 to 10–3 M) and different temperatures (298–328 K). The Inhibition efficiency was examined by gravimetric measurements, electrochemical methods supplemented with AFM, SEM-EDX, contact angle measurement, and XRD. The compounds have been characterized using IR, 1H NMR, 13C NMR, and mass spectra. It was found that AMT and AMH exhibit maximum inhibition efficiency of 90.52 and 93.28 %, respectively, at 10−3M against N80 CS corrosion in 1.0 M HCl solutions. The adsorption of inhibitors on the N80 CS surface tends to obey the Langmuir adsorption isotherm. Potentiodynamic polarization results revealed that AMT and AMH functioned as mixed-type inhibitors. All thermodynamic parameters were estimated and discussed. The combination of density functional theory (DFT) and molecular dynamic simulations was used to understand the sites in the AMT and AMH molecules where interaction with the N80 CS surface can occur. Results of the biological test revealed the excellent bioactivity of the AMT and AMH compounds, suggesting AMT and AMH are environmentally friendly corrosion inhibitors. [Display omitted] [ABSTRACT FROM AUTHOR]

Equipotential bonding, whereby objects are connected to a common electrical potential (usually ground) to prevent electrostatic discharges during material handling, has been shown to increase the risk of field-induced reticle damage. It is explained how the presence of an electric field can cause electrostatic damage in a reticle without a discharge event taking place. A comparison is drawn between the damage mechanisms that can take place in reticles and in semiconductor devices. The use of equipotential bonding during the manufacture of electrically sensitive semiconductor and micro-electro-mechanical systems is discussed. It is concluded that while equipotential bonding eliminates the risk of ESD during material handling, it simultaneously creates other risks for the devices being manufactured, which has the potential to introduce latent defects. An alternative methodology for dealing with electrostatic risk in semiconductor manufacturing is proposed, which would eliminate the undesirable enhancement of field-induction effects that is a consequence of using equipotential bonding.

This article possesses new exact wave structures to the Gilson–Pickering equation (GPE) that describes the prorogation of waves in plasma physics. The solutions are achieved in single and combined behavior like shock, singular, shock-singular, singular periodic waves and periodic as well rational function by utilizing innovative integration norms namely (G′G2)-expansion method and expansion function method (EFM). Moreover, under the suitable choice of involved parameters 3-, 2-dimensional, and their corresponding contour plots are also sketched. The obtained results show that the applied computational schemes are straightforward, efficient, concise and can be utilized for more complex physical phenomena in various fields of sciences. The reported results are helpful to understand the studying of wave propagation and are also vital for numerical and experimental verification in plasma physics.

Introduction: A "Primary Learner Assessment" (PLA) was created to provide an individualized learning plan, offering education as part of a 4‐step computer‐based process. The PLA is intended to improve learner's knowledge, skills, and patient safety perceptions, regarding interpretation of electronic fetal monitoring (EFM) data and administration of appropriate interventions in a timely fashion to mitigate fetal and maternal risks. Research was conducted to determine if learner knowledge, skills, and patient safety perceptions improved after completion of a 4‐step computer‐based, individualized adaptive‐learning process. Methods: Participants were registered nurses (RNs) responsible for administering and interpreting EFM, from three U.S. hospitals with labor and delivery units. This mixed method pilot study was determined to be exempt by the institutional review board; all participants provided consent. The process included four steps. In step one, RNs completed the baseline PLA. Based on incorrect quantitative and EFM interpretation responses, computer‐based EFM education courses were recommended (step two). After completion of recommended courses weeks or greater of practice (step three), the RNs completed a follow‐up PLA (step four). Results: Of the 55 RN participants, most (85.5%) were clinical nurses, had a bachelor degree in nursing or higher (80.0%), and 11.2 average years of labor and delivery experience. There was a statistically significant improvement (P <.0001) in overall average percentage of correct PLA scores from baseline (76.7, SD = 9.1) to follow‐up (82.5, SD = 6.9). Practice‐related perceptions showed increased ranking of familiarity with the National Institute of Child Health and Human Development (NICHD) 2008 EFM terminology and guidelines from baseline of 49.0% to follow‐up of 87.4% and of impact to which the participants integrated EFM administration and interpretation of NICHD EFM terminology and guidelines into practice from 52.8% at baseline to 94.5% at follow‐up. In addition, RNs perceived improvement in their oxygen therapy competence and accuracy in interpreting EFM data with implementation of appropriate interventions. Conclusion: These pilot study findings support a 4‐step, computer‐based individualized adaptive‐learning process as RNs responsible for EFM to potentially mitigate fetal and maternal risk had improved knowledge and skills. Research is warranted in larger samples. [ABSTRACT FROM AUTHOR]

Expired Famotidine was tested as a corrosion protection for α-brass in 1 M HCl using modified methods: weight loss (WL), Tafel polarization (TP), AC impedance spectra (EIS) and electrochemical frequency modulation (EFM). The polarization resistance (Rp) data increased with increasing famotidine dose. The inhibition efficiency (IE) improved with raising famotidine concentration. The maximum IE of 90% has been achieved at 300 ppm. On the other hand, the efficiency lowered with temperature increased. The outcome data obtained revealed that famotidine performed excellently as a corrosion inhibitor for α‑brass in this medium at dissimilar temperatures. The surface of α-brass was tested utilizing scanning electron microscope (SEM), energy dispersion spectroscopy X-ray spectra (EDX), Fourier transform infrared spectroscopy (FT–IR), and atomic force microscopy (AFM analysis). [ABSTRACT FROM AUTHOR]

The behavior of Cu in 1 M mixture of nitric and phosphoric acids containing different concentrations of moringa oleifera leaves (MOL) extract has been studied by weight loss (WL) and electrochemical techniques [potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM)]. The maximum inhibition efficiency was found to be 89% at concentration 0.300 mol L-1 of the extract at 298K after 3 hours immersion period. The inhibition efficiency (IE) increased with increasing the extract concentration while decreased with increasing the temperature indicates that the extract is physically adsorbed on Cu surface. The adsorption of the extract follows Langmuir adsorption isotherm. Some thermodynamic parameters of activation and adsorption processes were also determined and discussed. Surface analysis was also studied.

The corrosion performance of α-brass in 1 M HNO3 and in the presence of polyethylene glycol (PEG) has been investigated using AC impedance spectra (EIS), potentiodynamic polarization (PP), electrochemical frequency modulation (EFM), and mass reduction (MR) techniques. The outcome data of EIS showed a rise in the resistance charge transfer (Rct) and a decrease in the capacitance double layer (Cdl). Protection efficiency (IE) of PEG has been obtained by varying the dose of the PEG and temperature. PEG adsorbed on α-brass in acidic solution follows isotherm Langmuir. The polarization curves displayed that PEG acts as a mixed-kind inhibitor. The parameters obtained from thermodynamic activation of corrosion α-brass in 1 M HNO3 were obtained and debated. The results obtained from all tests were in excellent agreement.

The adsorption action of polyethylene oxide (PEO) on copper surface in 3.5 wt.% NaCl solution was tested using electrochemical frequency modulation (EFM), atomic absorption spectrometry (AAS), UV- visible spectrometry and the morphology of copper surface was investigated by attenuated total reflectance spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) techniques. Results obtained show that PEO is effective in preventing the corrosion of copper in NaCl solution. The adsorption of PEO onto copper surface was found to follow Langmuir isotherm model. ATR-FTIR, SEM and EDX spectroscopy techniques confirmed the adsorption of protective film of PEO on copper surface. Further, quantum chemical calculations were in agreement with inhibition efficiency (%I) of PEO that were obtained experimentally. [ABSTRACT FROM AUTHOR]

The effect of different pH values of artificial sea water on the passivation behavior and the pitting corrosion resistance of Ni70Cr21Si0.5B0.5P8C≤0.1Co≤1Fe≤1 (VZ1) and Ni72.65Cr7.3Si6.7B2.15C≤0.06Fe8.2Mo3 (VZ2) glassy alloys were studied using impedance spectroscopy measurements (EIS), cyclic polarization, and electrochemical frequency modulation techniques. The results showed that the alloys undergo a general corrosion process and tend to form an oxide film on the alloy surface, developing a stable protective layer in the artificial seawater solution. In both alloys, the lower corrosion current density was observed at a pH of 8.5 but had less pitting corrosion resistance. The VZ1 alloy had a relatively lower passive current density value, having a smaller anodic hysteresis loop area compared to the VZ2 alloy. The effect of the medium's pH on corrosion potential, corrosion current density, pitting potential, and repassivation potential was investigated and discussed, as was surface morphology. [ABSTRACT FROM AUTHOR]

Novel anionic 4-tert-Octylphenol Ethoxylated Phosphate Dipotassium salt (ethoxylated with 5 moles of ethylene oxide) surfactant was prepared and designated as OP-5-EO-K2PO, was characterized for its structure using spectroscopic measurements, in addition, its surface properties were investigated. The results indicated that OP-5-EO-K2PO exhibits excellent surface activity. Evaluation of the prepared surfactant as a corrosion inhibitor was carried out. The inhibition effect of OP-5-EO-K2PO surfactant, on the corrosion of C-steel in 0.5 M HCl was studied by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. It was found that the novel anionic surfactant acts as effective inhibitor and its inhibition efficiency was significantly increased with increasing concentration. Polarization curves revealed that the novel prepared anionic surfactant represents mixed-type inhibitors. Adsorption of the investigated surfactant led to a reduction in the double layer capacitance and an increase in the charge transfer resistance. [ABSTRACT FROM AUTHOR]

Nowadays, the search for novel compounds by chemical synthesis is in trend. Herein, we report the deposition of Cd 1- x - y Zn x Cu y Se (0.025 ≤ x = y ≤ 0.15) films by facile, industry-oriented chemical synthesis. The Cd 1- x - y Zn x Cu y Se thin films were deposited at the optimized growth conditions (temperature = 70 ± 0.1 °C, pH = 10.3 ± 0.1, substrate rotation speed = 70 ± 2 rpm and time = 100 min). As-synthesized thin films were characterized for physical, chemical, topographical and electrical attributes. The study of vibrational modes in Cd 1- x - y Zn x Cu y Se thin films was done with the help of Raman spectroscopy. Improvement in surface topography with the integration of Cu2+ and Zn2+ into the CdSe lattice has been noticed by the atomic force microscopy (AFM). The electrochemical impedance spectroscopy revealed lower values of R s and R ct for x = y = 0.05 composition. Chemical deposition of Cd 1- x - y Zn x Cu y Se thin films may offer an excellent way to fabricate quaternary chalcogenide-based absorber materials for solar cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bismuth ferrite at titanium dioxide nanotubes was prepared. • Charge trapping centers are formed in the sample. • Fractal analysis shows the surface changes under applied voltages. A heterostructure BiFeO 3 /TiO 2 (Nt)Ti (BFOT) was obtained by the atomic layer deposition (ALD) method. After thermal treatment, the redistribution of Fe/Ti atoms forms an Aurivillius intermediate layered phase, and local charge capture centers are formed in the sample. Due to cationic non-stoichiometry, the BFO film exhibits p -type conductivity, while the nanotubes exhibit n -type conductivity due to oxygen vacancies. It was observed that lateral displacement of the sample can lead to ferroelectric switching, which can, in turn, affect the transition of the memristive structure from high-resistance (HRS) to low-resistance states (LRS). The hysteresis suppression tends to transition to an ohmic character and depends on the amplitude, frequency, and duration of the periodic signal. It has been found that compensation of static charge during resistive switching can affect the transport properties of the material. Fractal dimension analysis showed an acceleration of structure restructuring with increasing voltage, possibly contributing to the transition from an insulator to a metal in certain areas of the film volume. The joint analysis of piezoresponse force microscopy (PFM), electrostatic force microscopy (EFM), and fractal/multifractal dynamics showed a correlation between surface static charge and piezopotential. The new methodology described in this work can help understand the resistive switching processes in ferroelectric/semiconductor memristive structures. [ABSTRACT FROM AUTHOR]

• A suggested QSAR model was used to predict the corrosion inhibition efficiency of a newly synthesized bispyrazole derivative (BPYR-P). • The corrosion inhibitory efficiency of the BPYR-P is investigated using EFM, EIS, and PDP. • Adsorption of BPYR-P is physicochemical and spontaneous. • Surface characterizations were performed by SEM / EDX and AFM. • DFT and MD are utilized to investigate characteristic molecular parameters associated with inhibition efficiency. Using the potentiodynamic polarization (PDP) technique, a set of seven newly synthesized bispyrazole derivatives (PYR-1 to PYR-7) were examined as corrosion inhibitors for 304 stainless steel (304 SS) in 1.0 M HCl solutions at different concentrations (10−13 to 10−5 M). The experimental results were used to create a predictive model for the anticorrosion properties of another inhibitor (BPYR-P) within the same family. The model was created by relating various physicochemical descriptors of the seven bispyrazol inhibitors to their experimental inhibitory efficiency using the quantitative structure-activity relationship (QSAR) methodology along with the genetic function approximation (GFA) technique. The predicted inhibition efficiency was validated by several electrochemical techniques, including electrochemical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP). The predicted QSAR values for BPYR-P showed good agreement with experimental data, establishing the reliability of the model in predicting the inhibitor's performance. The BPYR-P acts as an excellent corrosion inhibitor for 304 SS in a 1.0 M HCl solution, and its inhibition efficiency increases with the increase in concentrations. The double-layer capacitance (C dl) decreases and the charge transfer resistance of 304 SS increases as the BPYR-P concentrations increase. The adsorption of predicted BPYR-P on a 304 SS surface displayed mixed-type inhibitor and obeyed the Langmuir adsorption isotherm. AFM, SEM-EDX, UV–visible spectra, contact angle measurement, XRD, parameters derived from quantum chemical calculations (DFT) and molecular dynamic simulations (MD) were in good agreement with the experimental data obtained. [Display omitted] [ABSTRACT FROM AUTHOR]

High Hydrostatic Pressure (HHP) technology is considered an alternative method of food preservation. Nevertheless, the current dogma is that HHP might be insufficient to preserve food lastingly against some pathogens. Incompletely damaged cells can resuscitate under favorable conditions, and they may proliferate in food during storage. This study was undertaken to characterize the extent of sublethal injuries induced by HHP (300–500 MPa) on Escherichia coli and Listeria inncua strains. The morphological changes were evaluated using microscopy methods such as Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Epifluorescence Microscopy (EFM). The overall assessment of the physiological state of tested bacteria through TEM and SEM showed that the action of pressure on the structure of the bacterial membrane was almost minor or unnoticeable, beyond the L. innocua wild-type strain. However, alterations were observed in subcellular structures such as the cytoplasm and nucleoid for both L. innocua and E. coli strains. More significant changes after the HHP of internal structures were reported in the case of wild-type strains isolated from raw juice. Extreme condensation of the cytoplasm was observed, while the outline of cells was intact. The percentage ratio between alive and injured cells in the population was assessed by fluorescent microscopy. The results of HHP-treated samples showed a heterogeneous population, and red cell aggregates were observed. The percentage ratio of live and dead cells (L/D) in the L. innocua collection strain population was higher than in the case of the wild-type strain (69%/31% and 55%/45%, respectively). In turn, E. coli populations were characterized with a similar L/D ratio. Half of the cells in the populations were distinguished as visibly fluorescing red. The results obtained in this study confirmed sublethal HHP reaction on pathogens cells.

The effect of Calotropis Procera (CP) extract on the corrosion inhibition of 304 stainless steel (SS) in 2 M HCl was studied using electrochemical (electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PP) and electrochemical frequency modulation (EFM) and chemical weight loss (WL) methods at 25ºC. The adsorption of the extract on 304 SS surface is consistent with Langmuir adsorption isotherm. The polarization plots revealed that the addition of extract shifts the cathodic and anodic branches towards lower currents. Such shifts indicate that CP extract acts as a mixed-type inhibitor. The thermodynamic parameters of activation and adsorption processes were calculated and discussed. The surface morphology of the 304 SS specimens was evaluating using different techniques.

Modazar drug was tested as corrosion inhibitor for carbon steel in 1 M HCl solution using chemical (weight loss and gasometric) and electrochemical (open {circdeg;}uit potential, potentiodynamic polarization, electrochemical frequency modulation and electrochemical impedance spectroscopy) techniques. The results showed that the inhibitory efficiency increased with the increase in drug concentration reaching a maximum value of 92.3% at 300 ppm while it decreases with increasing the temperature. Polarization curves showed that Modazar drug is a mixed type inhibitor but the cathode is more polarized than the anode. The drug was adsorbed physically on the C-steel surface obeying Langmuir adsorption isotherm. The morphology of the surface of the specimens was analyzed using atomic force microscopy, energy dispersion spectroscopy and scanning electron microscopy. The results obtained from chemical and electrochemical techniques are in good agreement.

El Ti6Al4V ELI (ASTM F136) es una de las aleaciones más empleadas en dispositivos de osteosíntesis y reemplazo articular. Sin embargo, las propiedades de esta aleación pueden ser mejoradas respecto a su biocompatibilidad y osteointegración con el tejido óseo a través de recubrimientos. El objetivo de este trabajo fue evaluar el comportamiento electroquímico de un recubrimiento obtenido por oxidación por plasma electrolítico sobre Ti6Al4V ELI empleando soluciones electrolíticas enriquecidas con iones de PO4 2-, Ca+2, Si+4 y varias concentraciones de Ag+1. Los recubrimientos se caracterizaron mediante espectroscopia de impedancia electroquímica (EIS) y Mott-Schottky (M-S) en una celda de tres electrodos con una solución fisiológica simulada. El comportamiento electroquímico se contrastó con microscopía de fuerza electrostática (EFM), donde se analizó el potencial eléctrico del recubrimiento. Los resultados de EIS mostraron mejores propiedades de estabilidad frente a la corrosión en los sustratos recubiertos con Ca- P-Ag, comparados con los recubiertos con Ca-P-Si-Ag. Los espectros de Nyquist y Bode mostraron relajaciones relacionadas con la transferencia de carga hacia la doble capa electroquímica como reflejo de los cambios microestructurales y de conductividad de los recubrimientos, dada por la presencia particular en cada caso, de los elementos contenidos en estos. De acuerdo con los resultados de M-S, todas las muestras ensayadas presentaron un comportamiento con dopado tipo n, cuya conductividad incrementó con la inclusión de plata. Mediante EFM se observaron mayores contrastes en el potencial, fase y la amplitud de los recubrimientos con mayor cantidad de plata respecto al Ti6Al4V sin recubrir.

This paper describes a new coding method based on binary $(d,k)$ runlength constraints used for recording or transmitting an audio or video signal, computer data, etc. Data words of $m$ bits are translated into codewords of $n$ bits using a conversion table. The codewords satisfy a $(d,k)$ runlength constraint in which at least $d$ and not more than $k$ ‘0’s occur between consecutive ‘1’s. The $n$ -bit codewords alternate with $p$ -bit merging words which in the prior art are selected such that the $d$ and $k$ are satisfied at the borders of consecutive codewords. We present a new coding method, where the codewords obey the $(d,k)$ -constraint, but the merging words are not required to obey the $(d)$ -constraint. The merging word that satisfies said conditions, yielding the lowest low-frequency spectral content of the encoded signal obtained after modulo-2 integration, is selected. The spectral performance of the new coding method has been appraised by computer simulations for the EFM (Eight-to-Fourteen Modulation) parameters, $d=2, k=10$ , and $p=3$. The low-frequency content of the signal generated by the newly presented coding method is around 4 dB lower in the relevant low-frequency range than that generated by the conventional EFM method. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study is to evaluate the associations of electronic fetal heart rate monitoring (EFM) patterns and adverse neonatal outcomes Study design: From 2013 to 2016; 12,067 term, singleton deliveries in labor ≥2 h with abnormal EFM defined as absent accelerations, variable, late or prolonged decelerations, tachycardia, bradycardia, or minimal variability were analyzed as any documentation during labor, in first hour and last hour of labor. Outcomes were composite neonatal adverse outcomes, neonatal intensive care unit (NICU) admission, neonatal hypoxia, neonatal hypoglycemia, umbilical artery pH, and base excess. Independent associations were ascertained using regression analysis. Results: Significant independent associations occurred between any abnormal EFM during the last hour and five adverse neonatal outcomes; between abnormal EFM at any time and one adverse neonatal outcome while there was none with the first hour of labor. In the last hour, accelerations had significant negative associations with three adverse neonatal outcomes, while prolonged decelerations, late decelerations, tachycardia, and bradycardia had significant positive associations with three adverse neonatal outcomes. Throughout labor, increasing accelerations events were significantly negatively correlated with all adverse neonatal outcomes, while increasing frequency of late, variable, and prolonged decelerations were positively associated with five adverse neonatal outcomes. Hierarchical analysis showed that bradycardia/tachycardia contributed only 0.8%, while all EFM periodic changes contributed 1%; the addition of the frequencies of abnormal EFM events contributed 0.6% to the variance in umbilical artery pH and base excess. Conclusions: Terminal EFM patterns are independently associated with neonatal outcomes. Accelerations are protective of adverse neonatal outcomes. Increasing frequency of EFM patterns overtime contributes to neonatal outcome. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study is to evaluate the associations of electronic fetal heart rate monitoring (EFM) patterns and adverse neonatal outcomes Study design: From 2013 to 2016; 12,067 term, singleton deliveries in labor ≥2 h with abnormal EFM defined as absent accelerations, variable, late or prolonged decelerations, tachycardia, bradycardia, or minimal variability were analyzed as any documentation during labor, in first hour and last hour of labor. Outcomes were composite neonatal adverse outcomes, neonatal intensive care unit (NICU) admission, neonatal hypoxia, neonatal hypoglycemia, umbilical artery pH, and base excess. Independent associations were ascertained using regression analysis. Results: Significant independent associations occurred between any abnormal EFM during the last hour and five adverse neonatal outcomes; between abnormal EFM at any time and one adverse neonatal outcome while there was none with the first hour of labor. In the last hour, accelerations had significant negative associations with three adverse neonatal outcomes, while prolonged decelerations, late decelerations, tachycardia, and bradycardia had significant positive associations with three adverse neonatal outcomes. Throughout labor, increasing accelerations events were significantly negatively correlated with all adverse neonatal outcomes, while increasing frequency of late, variable, and prolonged decelerations were positively associated with five adverse neonatal outcomes. Hierarchical analysis showed that bradycardia/tachycardia contributed only 0.8%, while all EFM periodic changes contributed 1%; the addition of the frequencies of abnormal EFM events contributed 0.6% to the variance in umbilical artery pH and base excess. Conclusions: Terminal EFM patterns are independently associated with neonatal outcomes. Accelerations are protective of adverse neonatal outcomes. Increasing frequency of EFM patterns overtime contributes to neonatal outcome. [ABSTRACT FROM AUTHOR]

Doping in organic–inorganic perovskite semiconductors is an effective method to tailor their optoelectronic properties. In this work, manganese-doped perovskite films with different Mn/Pb ratios ranging from 0% to 2% were systematically studied. The device performance of 0.2% Mn-doped devices was improved compared to that of a device without Mn. However, a further increase of the doping concentration induced a decrease in performance. Several characteristics (especially different scanning probe microscopy characteristics) reveal that an increased dopant concentration results in reduced crystallinity and a change in the film morphology and causes a deterioration in photovoltaic performance for higher dopant concentrations. In the best-performing samples (0.2%), a shift in the valence band level and band gap are found which are responsible for the increased open circuit voltage, while increased grain boundaries and lower surface charge density are responsible for a small reduction in the short circuit current. Thus, multifunctional scanning probe microscopy approaches, combined with different film characterization techniques, offer us effective tools to investigate the impact of doping in the perovskite materials and the corresponding device performance. • Scanning Kelvin Probe Microscopy is used to test the open circuit voltage of films. • Conductive atomic force microscopy is used to study the short-circuit of films. • Electrostatic force microscopy is used to distinguish the surface charge change of films. [ABSTRACT FROM AUTHOR]

Highlights • The protection performance of sol-gel coatings is enhanced by the synergism with the IL. • The internal IL modifier results in better protection efficiency than external modifier at high IL concentration. • R ct of modified sol-gel coatings is increased by six times compared to the unmodified coating. • The presence of the IL modifier increases the operation stability of protective coatings. • From SEM, cracks in protective coatings, due to corrosion disappeared upon modification. Abstract Unmodified and ionic liquid-modified sol-gel materials, based on tetraethylorthosilicate and 3-mercaptopropyl-trimethoxysilane, were synthesized and applied as protective coatings for cast iron corrosion in 0.5 mol L−1 HCl solution. The modification is done by adding 4-methyl-1-(prop-2-nyl) pyridinium ionic liquid at the early stage of the sol-gel synthesis, as an internal modifier, or by adding the ionic liquid in the corrosive medium while applying unmodified sol-gel coating on the metal surface, as an external modifier. Scanning electron microscope (SEM) is used to investigate the surface features of different coatings. Electrochemical measurements such as potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM) were performed to prove the synergism in the protection ability caused by the combination of the sol-gel coating and the ionic liquid inhibitor. The charge-transfer resistance of the sol-gel coating is increased by six times in the presence of the ionic liquid. The effect of the ionic liquid concentration on the protection efficiency in both types of modification was examined. Internal modification is more efficient at relatively higher ionic liquid concentration. Tafel polarization, conducted at different exposure time, showed the high operation stability of ionic liquid-modified sol-gel coatings. [ABSTRACT FROM AUTHOR]

Highlights • Wheat starch electrical characterization contributes to understand dust explosions. • Macroscale starch's permittivity decreases with the increment of frequency. • Macroscale starch's permittivity increases with humidity contents above 30%. • Microscale permittivity shows high values ≈82 and increases with temperature. • High microscale permittivity suggests that surface effects mediate dust ignition. Abstract Wheat starch is a widely used material in the food, pharmaceutical and entertainment industry not considered hazard but recently associated to dust explosions during processing and handling. How an insulating starch grain is charged and how its ability to be polarized is affected by environmental conditions such as temperature, humidity and frequency? are fundamental questions that must be explored in order to understand the dust explosion phenomena. Here we investigate the dependence of temperature, humidity and low-frequency on the relative permittivity of wheat starch. We characterized starch at the micro and macro scales using atomic force microscopy-based techniques and capacitive planar sensor-based measurements respectively. The results show high values of permittivity (˜80) at the microscale (single starch grains) compared to the low values (10–20) at the macroscale (20 mg of wheat starch). The differences are attributed to the Maxwell–Wagner–Sillars interfacial polarization process on individual grains and potential charge exchange between grains. Permittivity is a critical property to investigate starch electrostatic hazards. [ABSTRACT FROM AUTHOR]

Abstract Electrochemical behavior of two Metal-Metal glassy alloys Fe 78 Co 9 Cr 10 Mo 2 Al 1 (VX9) and Fe 49 Co 49 V 2 (VX50) (at.%) were investigated at different immersion times in artificial acid rain at 20 °C using electrochemical techniques as electrochemical impedance spectroscopy (EIS) and cyclic polarization (CP). The morphology and composition of alloy surface were investigated using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) measurements and atomic force microscopy (AFM). VX9 alloy has high corrosion resistance more than VX50 due to good protective elements as Cr 10% that create chromium oxide. Immersion measurements during (0.5–12 h) reveal the critical time for VX9 alloy is about 3 h to begin corrosion resistance while the VX50 alloy take a longer time to form protective film. The susceptibility of studied alloys for localized corrosion was observed by cyclic-polarization data due to passive film of two layers (inner compact and outer prose). The VX50 alloy has low value of charge transfer resistance due to exposure to more pitting attack. The AFM and SEM images found that average surface roughness (Ra) of VX9 alloy is lower than VX50 alloy. [ABSTRACT FROM AUTHOR]

Structural analysis of constraint-based metabolic network models attempts to find the network’s properties by searching for subsets of suitable modes or Elementary Flux Modes (EFMs). One useful approach is based on Linear Program (LP) techniques, which introduce an objective function to convert the stoichiometric and thermodynamic constraints into a linear program (LP), using additional constraints to generate different nontrivial modes. This work introduces FLFS-FC (Fixed Length Function Sampling with Flux Coupling), a new approach to increase the efficiency of generation of large sets of different EFMs for the network. FLFS-FC is based on the importance of the length of the objective functions used in the associated LP problem and the imposition of additional negative constraints. Our proposal overrides some of the known drawbacks associated with the EFM extraction, such as the appearance of unfeasible problems or multiple repeated solutions arising from different LP problems.

Scanning Kelvin probe microscopy (SKPM), electrostatic force microscopy (EFM) are used to study the microscopic processes of the photo-induced charge separation at the interface of Ag and conductive polymers, i.e., poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-bʹ]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) and poly(3-hexylthiophene-2,5-diyl) (P3HT). They are also widely used in order to directly observe the charge distribution and dynamic changes at the interfaces in nanostructures, owing to their high sensitivity. Using SKPM, it is proved that the charge of the photo-induced polymer PCPDTBT is transferred to Ag nanoparticles (NPs). The surface charge of the Ag-induced NPs is quantified while using EFM, and it is determined that the charge is injected into the polymer P3HT from the Ag NPs. We expect that this technology will provide guidance to facilitate the separation and transfer of the interfacial charges in the composite material systems and it will be applicable to various photovoltaic material systems.

Abstract A new cationic surfactant named (N-(3-(dimethyl hexadecyl ammonio)propyl) palmitamide bromide has been evaluated as corrosion inhibitor for API N80 Steel Pipelines in 1M HCl solution. Four different techniques have been utilized for studying the corrosion behavior of the synthesized cationic amphipathic corrosion inhibitor. The prepared corrosion inhibitor was evaluated at five different temperatures 25, 30, 40, 50 and 60 °C, using weight loss technique. The three other techniques which are potentiodynamic polarization, Electrochemical impedance (EIS) and Electrochemical frequency modulation (EFM) were used for evaluation at room temperature (25 °C ± 1). The results outlined that the synthesized DMHPP amphipathic corrosion inhibitor was good inhibitor and their inhibition efficiencies were directly proportional with both the inhibitor concentration and temperature. Polarization curve revealed that the studied inhibitor act as a mixed-type of inhibitor. The adsorption of the used inhibitor led to a reduction in the double layer capacitance and an increase in the charge transfer resistance. The adsorption behavior of the amphipathic inhibitor obey Langmuir adsorption model. The change in free energy of adsorption of the synthesized inhibitor range from −40.5 to −45.5 kJ mol−1 as an indication for chemisorption process between inhibitor and steel. A clear correlation was found between corrosion inhibition efficiency and theoretical parameters obtained using density functional theory (DFT). [ABSTRACT FROM AUTHOR]

Highlights • The synthesized cationic surfactant HEDDB can be used as an effective corrosion inhibitor for steel in 1.0 M HCl. • Data of the Polarization exhibit that, the HEDDB synthesized surfactant acts as a mixed-type inhibitor. • Double layer capacitances value decreased with respect to the blank. • The adsorption of HEDDB inhibitor was detected to follow the Langmuir isotherm model. • The inhibition efficiency increases by increasing both HEDDB surfactant concentrations and temperature. • Theoretical study demonstrates the influence of molecular structure on inhibition efficiency. Abstract Corrosion inhibition of a novel cationic surfactant namely, N-(2-(2-hydroxyethoxy)ethyl)-N,N-dimethyldodecan-1-aminium bromide (HEDDB) was evaluated as a corrosion inhibitor for carbon steel in 1.0 M HCl by electrochemical frequency modulation (EFM), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. Results of Tafel polarization exhibit that the synthesized surfactant HEDDB behaves as mixed-type inhibitor. The effectiveness of temperature on the corrosion rate which evaluated by chemical technique (weight loss) was investigated and assessed. Langmuir's adsorption isotherm was the preferable fitted isotherm. The results of weight loss clarified that the efficiency of the synthesized surfactant increases with raising both the concentration of the surfactant and the temperature. HEDDB effectiveness on the morphology of metal surface was monitored by Atomic Force Microscopy (AFM) and Scanning Electron Microscope (SEM) techniques. Quantum chemical technique has been employed to discuss the inhibition efficiency by effectiveness of molecular structure of the synthesized inhibitor. The various techniques which used in this research have inhibition efficiency (IE) with the same direction. [ABSTRACT FROM AUTHOR]