Apparent Resistance Research Articles

Influence of catholytes on the generation of steel corrosion in concrete with accelerated chloride migration method

In the aim of developing localized corrosion, artificial corrosion on a steel sheet coated with concrete was implemented through accelerated chloride migration with a constant applied voltage (20 V). Four chloride solutions (20 g/L NaCl) with different initial pH were used. The pH values and chloride concentrations of the solutions were recorded during the test. Electrochemical non-destructive measurements of corrosion potential (Ecorr) and apparent linear polarization resistance (Rp,app) of the steel sheet were made. The concrete cover was then removed to observe corrosion visually (autopsy). The corrosion products were characterized by XRD and SEM and the results showed that the migration of chloride ions in concrete was slowed down by hydroxide ions, which was highlighted by a reduction of chloride transport number. Whether chloride ions were present at the steel interface or not, corrosion occurred because of acidification at the steel sheet/concrete interface due to the anodic polarization. However, when chloride ions were present, the corrosion propagation phase started earlier and the corrosion rate was higher.

Prevalence of Elizabethkingia meningoseptica Infections and their Resistant Pattern in Tertiary Care Hospital

Elizabethkingia meningoseptica a rare pathogen in earlier times has been accused to infect the immunocompromised, preterm neonates, the patients exposed to longterm antibiotics and intensive care units. The apparent resistance of the multidrug Elizabethkingia meningoseptica affects the selection of appropriate antibacterial agents against it. The current study attempts to determine the prevalence of E. meningoseptica infections and consider the sensitivity pattern in a tertiary care hospital. A prospective study of prevalence of E. meningoseptica in a tertiary care hospital from March 2020 to March 2021 i.e over a period of 1 year. Patient clinical data as well as ABST patterns were collected and analyzed. Out of total 1813 patient’s samples E. meningoseptica was isolates from 21 cases (1.15%). Average age was 61.42 years, with males most likely to be infected (52.38%). All the adult patients had underlying diseases, obstructive gall bladder diseases (n=7, 33.33%) which included choledocholithiasis, obstructive jaundice, cholangitis and carcinoma gallbladder. Urinary tract diseases (n=8, 38.09%) which include chronic kidney disease (CKD) and acute kidney disease (AKD), pneumonia (n=11, 52.38%) including urosepsis and other diseases AML (n=1, 04.7%). Susceptibility tests showed 100% in vitro against few antimicrobials like cefepime, meropenem and amikacin which can be utilized to treat most common Gram-negative bacterial infections. Isolates are usually the completely sensitive to minocycline. E. meningoseptica is a rising microbe in intensive care setup due to its resistance pattern.

Comparison of structural and functional properties of maize starch produced with commercial or endogenous enzymes

To explore an effective and economic method to prepare higher contents of resistant starch (RS), different enzyme treatments including single pullulanase (PUL), commercial α-amylase (AA) or/and β-amylase (BA) with PUL, and malt endogenous amylase (MA) with PUL were used and the structural, physicochemical properties and digestibility of all modified starches (MS) were compared. All the enzyme-treated starches displayed a mixture of B and V-type diffraction patterns. The MA/PUL-MS showed higher V-type diffraction peak intensity as compared to other modified starches. Compared to the combination of commercial enzyme treatment, the combination of malt enzyme treatment led to higher apparent amylose contents (45.56%), RS content (53.93%) and thermal stability (302 °C), whereas it possessed lower solubility indices and predicted glycaemic index. The apparent viscosity and shear resistance of MA/PUL-MS were lower than that of AA/PUL-MS, whereas that of MA/PUL-MS was higher than that of BA/PUL-MS and BA/AA/PUL-MS. These findings would provide a theoretical and applicative basis to produce foods with lower GI in industrial production.

Musa Germplasm A and B Genomic Composition Differentially Affects Their Susceptibility to Banana Bunchy Top Virus and Its Aphid Vector, Pentalonia nigronervosa.

Banana bunchy top disease (BBTD), caused by the banana bunchy top virus (BBTV, genus Babuvirus), is the most destructive viral disease of banana and plantain (Musa spp.). The virus is transmitted persistently by the banana aphid, Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae). While research efforts have focused on screening Musa genotypes for BBTD resistance, comparatively little work has been carried out to identify resistance to banana aphids. This study assessed 44 Musa germplasm of different A and B genome composition for the performance of banana aphids under semicontrolled environmental screenhouse conditions and in a field trial established in a BBTD endemic location. In the screenhouse, the AA diploid Calcutta 4 had the lowest apterous aphid density per plant (9.7 ± 4.6) compared with AAB triploid Waema, which had the highest aphid densities (395.6 ± 20.8). In the field, the highest apterous aphid density per plant (29.2 ± 6.7) occurred on the AAB triploid Batard and the lowest (0.4 ± 0.2) on the AA diploid Pisang Tongat. The AA diploid Tapo was highly susceptible to BBTD (100% infection) compared with the genotypes Balonkawe (ABB), PITA 21 (AAB), Calcutta 4 (AA), and Balbisiana Los Banos (BB), which remained uninfected. The Musa genotypes with apparent resistance to BBTD and least susceptibility to aphid population growth provide options for considering aphid and BBTD resistance in banana and plantain breeding programs.

Effects of solid particle aspect ratio on the performance of hydrogen production by electrolyzed water

Hydrogen energy has become one of the important directions of future energy development. The hydrogen produced by electrolyzed water is regarded as "green hydrogen", is clean and pollution-free, and is considered the ultimate direction of hydrogen production. If the waste heat of solid particles can be used as the energy required for the water electrolysis process, the cost of "green hydrogen" will be much lower than that of fossil fuel hydrogen production. In order to study the effect of particle structure size on hydrogen production capacity, the heat transfer model of the ellipsoidal particles packed bed with single-vacancy was constructed. Further, the temperature, the apparent thermal resistance, the average heat flux, and the vacancy affects area were studied. With the increase of the particle aspect ratio, the apparent thermal resistance decreases, the average heat flux increase, and hydrogen production increases. When the particle aspect ratio increases from 0.5 to 2.0, the average heat flux of the packed bed with single-vacancy increases from 23.13 kW/m2 to 28.87 kW/m2, and the apparent thermal resistance decreases from 23.33 K/W to 9.27 K/W. As the particle aspect ratio increases, the area affected by single-vacancy increases, the hindering effect of the vacancy on the heat flow increases.

Investigating the effect of diagenesis on ESR dating of Middle Stone Age tooth samples from the open-air site of Lovedale, Free State, South Africa

Teeth are usually targeted for dating archaeological sites because they are less prone to dissolution, in comparison with bones. However, despite this apparent resistance, teeth do undergo diagenesis, which needs to be accounted for in order to obtain accurate ages. In particular, the uptake of trace elements such as uranium in dental tissues needs to be considered for dose rate determination when dated using electron spin resonance (ESR). Characterising the mineralogy and structural integrity of samples prior to dating may thus provide important information related to their state of preservation, especially in the case of teeth whose U content can significantly affect the dose rate.

Fouling of mammalian hair fibres exposed to a titanium dioxide colloidal suspension.

Fouling of surfaces in prolonged contact with liquid often leads to detrimental alteration of material properties and performance. A wide range of factors which include mass transport, surface properties and surface interactions dictate whether foulants are able to adhere to a surface. Passive means of foulant rejection, such as the microscopic patterns, have been known to develop in nature. In this work, we investigate the anti-fouling behaviour of animal fur and its apparent passive resistance to fouling. We compare the fouling performance of several categories of natural and manufactured fibres, and present correlations between contamination susceptibility and physio-mechanical properties of the fibre and its environment. Lastly, we present a correlation between the fouling intensity of a fibre and the cumulative impact of multiple interacting factors declared in the form of a dimensionless group. Artificial and natural hair strands exhibit comparable anti-fouling behaviour in flow, however, the absence of flow improves the performance of some artificial fibres. Among the plethora of factors affecting the fouling of fur hair, the dimensionless groups we present herein provide the best demarcation between fibres of different origin.

Manganese Oxides (Mn3O4 & α‐MnO2) as Co‐catalysts in Pd‐Based Nanomaterials for the Ethylene Glycol Electro‐Oxidation.

AbstractIncorporation of α‐MnO2 and Mn3O4 during the synthesis of Pd nanoparticles promoted better particle anchoring. Especially the Mn single spinel (Mn3O4) decreased the Pd particle size from ∼10 nm (obtained for Pd/C and Pd/α‐MnO2) to 4.4 nm. HR‐TEM and XPS analysis confirmed electronic changes from a better interaction between Pd and Mn3O4, decreasing the energy barriers for alcohol oxidation, obtaining the lowest apparent activation energy (15.54 kJ mol−1) and resistance to charge transfer (1.44 Ω cm2). The Pd/Mn3O4/C electrocatalyst displayed a current density of 334.74 mA cm−2 at 2 M EG+2 M KOH with an onset potential of −0.32 V vs. NHE. This current density was 2.2 and 3.6‐fold higher than that obtained using Pd/C and Pd/α‐MnO2/C. Further tests using sorbitol and glycerol as fuels revealed that maximum current densities of 255.2 and 472.9 mA cm−2 can be achieved.

Optimized Anticorrosion of Polypyrrole Coating by Inverted-Electrode Strategy: Experimental and Molecular Dynamics Investigations.

To improve the poor adhesion and the ensuing insufficient anticorrosion efficacy of electropolymerized polypyrrole (PPy) on copper surface, an inverted-electrode strategy was applied after the passivation procedure, for which the compact coating (PPy-I) was deposited on the substrate in a cathodic window. Morphological and physical characterizations revealed that PPy-I exerted satisfactory adhesion strength and suitable thickness and conductivity compared with the analogue prepared via the traditional protocol (PPy-T). Potentiodynamic polarization, electrochemical impedance spectroscopy and frequency modulation were employed to ascertain the propitious protection of PPy-I for copper in artificial seawater (ASW). Due to the dominant electroactivity, the PPy-I-coated sample possessed higher apparent current density and lower charge transfer resistance than its PPy-T-protected counterpart, which maintained the passivation of the substrate. Surface analysis also supported the viability of PPy-I for copper in ASW for a well-protected surface with inferior water wettability. Molecular dynamics simulations evidenced that PPy-I with the higher density retained efficient anticorrosion capacity on copper at elevated temperatures. Therein, the derived time-dependent spatial diffusion trajectories of ions were locally confined with low diffusion coefficients. Highly twisted pore passages and anodic protection behavior arising respectively from the tight coating architecture and electroactivity contributed to the adequate corrosion resistance of PPy-I-coated copper.

Geophysical characteristics of the Belaya Gora gold deposit (Khabarovsk Krai, Russia)

Research subject. SThe geophysical fields and physical properties of altered gold-bearing rocks within the Belogorskoye ore field and the Belaya Gora gold deposit located in the Khabarovsk Krai.Materials and methods. Magnetic field and the distribution of electrical resistivity and polarisability obtained during land-based surveys as well as magnetic susceptibility, apparent electrical resistivity and polarisability of the samples from trenches and drilling cores have been studied. The analysis of the spatial correlation of the features of geophysical fields and gold mineralisation has been carried out. The physical properties of rocks are analysed depending on the intensity and type of superimposed hydrothermal alterations and gold content.Results. A significant decrease of magnetic susceptibility for all types of altered rock is indicated. Differences in electrical resistivity and polarisability are observed for hydrothermally altered rocks of the pre-ore stage and ore-bearing metasomatites. The former, with a relatively increased electrical resistance, have the highest polarisability (within the ore field), while the latter are characterised by an even higher resistance, but with the significant decrease in polarisability, which remains slightly elevated relative to unaltered rocks. These patterns also determine the geophysical characteristics of the ore field and deposit. The gold ore field is characterised by a significant decrease in the magnetic field intensity, an areal anomaly of increased polarisability, and, in general, an increased apparent electrical resistance. The deposit itself, as an area covering ore bodies, is generally characterised by an even more intensive increase in apparent electrical resistivity and a relative decrease in polarisability against its generally high background.Conclusions. Based on the performed research, a geophysical model of the Belaya Gora gold deposit is proposed, which may be used as a reference during the planning of geophysical works and the interpretation of geophysical data during the exploration works for epithermal gold mineralisation within the volcanic-tectonic structures in the Nizhne-Amursky region.

Modeling and simulation of needle electrical impedance myography in nonhomogeneous isotropic skeletal muscle.

Needle electrical impedance myography (EIM) is a recently developed technique for neuromuscular evaluation. Despite its preliminary successful clinical application, further understanding is needed to aid interpreting EIM outcomes in nonhomogeneous skeletal muscle measurements. The framework presented models needle EIM measurements in a bidomain isotropic model. Finite element method (FEM) simulations verify the validity of our model predictions studying two cases: a spherical volume surrounded by tissue and a two-layered tissue. Our models show that EIM is influenced by the vicinity of tissue with different electrical properties. The apparent resistance, reactance and phase relative errors between our theoretical predictions and FEM simulations in the spherical volume case study are ≤0.2%, ≤1.2% and ≤1.0%, respectively. For the two-layered tissue model case study, the relative errors are ≤2%. We propose a bio-physics driven analytical framework describing needle EIM measurements in a nonhomogeneous bidomain tissue model. Our theoretical predictions may lead to new ways for interpreting needle EIM data in neuromuscular diseases that cause compositional changes in muscle content, e.g. connective tissue deposition within the muscle. These changes will manifest themselves by changing the electric properties of the conductor media and will impact impedance values.

Indicators for the preliminary assessment of magnetotelluric data sufficiency

The study was aimed at determining the sufficiency of the data obtained as a result of recording signals in the magnetotelluric sounding method. Based on the analysis of statistical methods and approaches to data processing and the characteristic properties of signals containing correlated and uncorrelated noise, a set of numerical indicators is proposed. These values can be used to assess the sufficiency of the data amount that will be used to obtain geoelectric structure. The key indicator is the coefficient describing the physical compliance of the apparent resistance, depending on the confidence intervals calculated at adjacent frequencies. The confidence intervals and the proposed coefficient can be used to make a decision about the statistical consistency of the gathered data and can be calculated in the data acquisition equipment.

A chameleon in the marrow – one germ cell tumour, two leukaemias

Mediastinal germ cell tumours (MGCTs) are rare malignancies found in the paediatric age group. Unlike the majority of germ cell tumours, non-seminomatous primary MGCTs tend to have a poor prognosis, and multiple additional malignancies have been reported in these patients. Approximately 6% will develop haematological malignancies, unrelated to prior treatment, which are associated with an extremely poor prognosis.1 These leukaemias seem to have a shared clonal origin with the MGST, possibly explaining their apparent resistance to standard leukaemia treatments.

Nonvolatile Ferroelectric‐Domain‐Wall Memory Embedded in a Complex Topological Domain Structure

The discovery and precise manipulation of atomic-size conductive ferroelectric domain walls offers new opportunities for a wide range of prospective electronic devices, and the emerging field of walltronics. Herein, a highly stable and fatigue-resistant nonvolatile memory device is demonstrated, which is based on deterministic creation and erasure of conductive domain walls that are geometrically confined in a topological domain structure. By introducing a pair of delicately designed coaxial electrodes onto the epitaxial BiFeO3 film, a center-type quadrant topological domain with conductive charged domain walls can be easily created. More importantly, reversible switching of the quadrant domain between the convergent state with highly conductive confined walls and the divergent state with insulating confined walls can be realized, resulting in an apparent resistance change with a large on/off ratio of >104 and a technically preferred readout current (up to 40nA). Owing to restrictions from the clamped quadrant ferroelastic domain, the device exhibits excellent restoration repeatability over 108 cycles and a long retention of over 12days (>106 s). These results provide a new pathway toward high-performance ferroelectric-domain-wall memory, which may spur extensive interest in exploring the immense potential in the emerging field of walltronics.

EcoBlends’up: PLA/BioPA blends composites, microfibrillated “in situ” through additive manufacturing

In certain polymer blends, a properly oriented microfibrillar morphology of the dispersed phase during the processing stage can generate a reinforcing effect by increasing the fracture toughness, especially in the crack propagation stage. These types of materials are called “in situ” microfibrillated composites (MFCs). Its obtention is conditioned by the rheological properties of the blend and the parameters of the forming process. In this context, additive manufacturing is of interest, specially fused filament fabrication (FFF) by pellets supply instead of extruded filaments. In this work, the study of the feasibility of manufacturing MFCs is proposed by inducing the microfibrillation of a BioPA in the PLA/BioPA “ecoblends”. The optimal processing conditions of the FFF process for the generation of MFCs are evaluated, as well as the uniaxial tensile behavior and the fracture behavior of the manufactured SENB test specimens, employing instrumented impact technique. The evidence obtained shows that the use of a rheologically modified PLA matrix by reactive extrusion (PLAREX) promotes the obtention of MFCs with a better balance of mechanical properties in terms of elastic modulus (E) and ductility and an improvement in apparent toughness and resistance to crack propagation of the fabricated part.

Impact of changed co-amoxiclav susceptibility testing formats on apparent resistance rates for bloodstream Escherichia coli in a long-term surveillance.

Impact of changed co-amoxiclav susceptibility testing formats on apparent resistance rates for bloodstream Escherichia coli in a long-term surveillance.

Protection of steel tube against corrosion using self-prestressing UHPC prepared with expansive agent and steel fibers

The use of monopiles for onshore and offshore wind turbines structures is gaining increasing popularity. However, steel exposed to atmospheric and oceanic environments is susceptible to corrosion. Previous studies suggested using concrete cover to inhibit corrosion, while limited promising result was achieved. In this regard, self-prestressing ultra-high-performance concrete (SPUHPC) utilizing the synergy between expansive agent (EA) and steel fibers (SF) was developed for concrete-steel tubular columns (CSTCs) to evaluate the corrosion behavior. Various concrete cover thicknesses were considered to examine the corrosion behavior under a constant anodic current. Results show that the apparent specific resistance was improved. The concrete cover cracking time and corrosion rate were delayed up to 40.1% and 97.4% with the combined addition of EA and SF in SPUHPC. Moreover, micro X-ray computed tomography (CT) analysis revealed that the combined use of EA and SF yields a denser microstructure. In addition, scanning electron microscopy (SEM) revealed that EA improved the bond for sand-matrix and fiber-matrix interface. An inverse relationship between average apparent specific resistance and average corrosion rate was identified quantitatively.

Schwannoma:Update on Molecular Profiling and Therapeutic Advances

Schwannoma is a tumor that develops from the Schwann cells in the peripheral nervous system or cranial nerves. Gamma Knife radiosurgery has become an accepted treatment for schwannoma, with a high rate of tumor control. For sporadic or neurofibromatosis type 2-associated schwannoma resistant to radiotherapy, vascular endothelial growth factor(VEGF)-A/VEGF receptor(VEGFR)-targeted therapy(e.g., bevacizumab)may become the first-line therapy. However, some aspects of treatment with bevacizumab are problematic, such as the need for frequent parenteral administration, side effects, apparent drug resistance, and rebound tumor progression after cessation. In these situations, the gene product of the SH3PXD2A-HTRA1 fusion and several protein tyrosine kinase inhibitors may be supportive in preventing tumor progression because merlin inhibits signaling by tyrosine receptor kinases and there is activation of downstream pathways, including the Ras/Raf/MEK/ERK and PI3K/Akt/mTORC1 pathways. Although the tumor-microenvironment(TME)plays a key role in tumor growth, this physiological state is unclear in schwannoma. Tumor-associated macrophages may be a major component of the immunosuppressive cells in the TME of schwannoma. To impede tumor growth, the TME is also explored as a potential therapeutic target. Multimodal therapy is required to manage patients with refractory schwannoma. Furthermore, basic scientific research may be essential in achieving a novel treatment strategy.

High-throughput Growth Measurements of Yeast Exposed to Visible Light.

Light is a double-edged sword: it is essential for life on the planet but also causes cellular damage and death. Consequently, organisms have evolved systems not only for harvesting and converting light energy into chemical energy but also for countering its toxic effects. Despite the omnipresence and importance of such light-dependent effects, there are very few unbiased genetic screens, if any, investigating the mechanistic consequences that visible light has on cells. Baker's yeast, Saccharomyces cerevisiae, is one of the best annotated organisms thanks to several easily available mutant collections and its amenability to high-throughput genetic screening. However, until recently this yeast was thought to lack receptors for visible light, therefore its response to visible light was poorly understood. Nevertheless, a couple of years ago it was discovered that yeast senses light via a novel and unconventional pathway involving a peroxisomal oxidase, hydrogen peroxide, and a particular type of antioxidant protein, called peroxiredoxin. Here, we describe in detail a protocol for scoring yeast genes involved in the resistance to visible light (400-700 nm) on a genome-wide scale. Because cells in dense cultures shield each other from light exposure, resulting in apparent light resistance, our method involves adaptations to reduce inoculum size under conditions amenable to high-throughput screens, to properly be able to identify light-sensitive mutants. We also describe how to measure growth in the presence of light, including two follow-up validation tests. In this way, this method makes it possible to score light-sensitivity on a genome-wide scale with high confidence. Graphic abstract: Overview of strategy for high-throughput determination of yeast growth upon visible light stress.

Evaluation of Energy Efficiency Performance of Heated Windows

Fenestration systems are widely used across the world. There is expansive research on window configurations, frames, and glazing technology, but not enough research has been published on reducing window heat loss through heat application to a pane. The presented study attempted to evaluate the performance of heated windows by developing an experimental setup to test a window at various temperatures by varying the power input to the window. Heated double pane window was installed in an insulated box. A temperature gradient was developed across the window by cooling one side of the window using gel-based ice packs. The other face of the window was heated by enabling power at different wattages through the window. The temperature of the inside and outside panes, current and voltage input, and temperature of the room and box were recorded. The data was used to calculate the apparent effective resistance of the window when not being heated vs. when being heated. The study concluded that, when window temperature was maintained close to the room temperature, the heated double pane window is effective in reducing heat loss by as much as 50% as compared to a non-heated double pane window. When temperature of the window was much higher than the room temperature, the heat loss through the window increased beyond that of a non-heated window. The issues encountered during the current stages of experiments are noted, and recommendations are provided for future studies.