Scanning Electron Microscopy Photographs Research Articles

Improving the flame retardancy and smoke suppression of flexible PVC by incorporating zinc borate‐modified diantimony trioxide

AbstractThe properties and structure of flexible PVC by incorporating zinc borate (ZB)‐modified diantimony trioxide (Sb2O3) were investigated. The results of flame retardancy and smoke suppression testing indicate that there was an obvious maximum Limited oxygen index (LOI) value of PVC/20 wt.% ZB–Sb2O3 composites reached 37.5% and passed the UL 94 V‐0 rating. An obvious synergistic effect between ZB and Sb2O3 was observed by LOI, SDR, and TG. Moreover, remarkable decreases in the smoke density were observed when ZB–Sb2O3 was incorporated into PVC. In addition, the tensile strength and elongation at break of PVC/ZB–Sb2O3 composites was higher than PVC/Sb2O3 composites, and this ameliorative effect was mainly arising from the ZB–Sb2O3 nanoparticles, which reduced the degree of fatal defects on PVC. The addition of ZB and Sb2O3 greatly increased the amount of residual char and apparently improved the mechanical properties of PVC composites. According to scanning electron microscopy photographs of residual char, after thermal decomposition, there were many fragments linked to the condensed phase and the compact char layer. Fourier transform infrared spectroscopy shows the residues char was composed of benzene ring, the flame retardants occurred and the condensed phase with significant interactions.

MORPHOMETRIC AND SCANNING ELECTRON MICROSCOPE-BASED IDENTIFICATION OF Taenia hydatigena PARASITES IN STRAY DOGS

Taenia hydatigena, an intestinal parasite of domestic and wild canids which can cause medical problems and economic losses in animals. Thirty T. hydatigena recovered from the intestine of stray dogs after T. hydatigena based on morphological characters and morphometric observations involving Scanning Electron Microscopy (SEM) and the scoleces were stained by Semichon's acid carmine and viewed on a light microscope. High-quality SEM photographs were shown the blade dimensions of both large and small hooks (83.89 µm and 48.16 µm) respectively, which was close to measurements by a digital camera. The number of hooks around the rostellum were 30 hooks, and both were equal in number (15 hooks), while the average length of the large hooks was 220.11 ±28.07 µm, and was 88.58 ±7.92, and the average length of small hooks was142.37 ±12.52 µm and was 65.73 ±6.94 µm. body surface of Taenia hydatigena presence of characteristic transverse cuticular striations.

Modulation of impedance matching of hollow cubic carbon with semi-closed structure for effective microwave absorption

In this paper, a certain degree of semi-closed structure was successfully introduced in hollow cubic carbons (HCCs) by selective dissolution of phenolic resin (PR)/NaCl precursor by acetone. The impedance matching of the HCCs absorber was improved, which in turn lead to the enhancement of the electromagnetic wave absorption capacity. By controlling the selective dissolution time of acetone, HCCs with different degrees of integrity were formed, and the degree and mechanism of the influence of the semi-closed structure of HCCs on the wave absorbing properties were investigated by analyzing the microstructure and physical phase composition of HCCs. From the scanning electron microscope photographs, it can be seen that with the increase of the acetone treatment time of HCCs, the samples gradually appeared a certain degree of semi-closed structure. With the extension of the acetone treatment time to 60 min, the structure of the HCCs was seriously damaged, at which time the impedance matching of the wave-absorbing materials was seriously deteriorated, and the electromagnetic wave absorption performance was also decreased. Among them, the electromagnetic wave absorption performance of HCCs30min is the most outstanding, specifically, when the loading rate is 10 wt%, the maximum absorption peak value of HCCs30min with a thickness of 2.7 mm reaches −41.1 dB, and the corresponding absorption bandwidth is 3.8 GHz (8.9 GHz–12.7 GHz). The experiment confirms that the existence of the degree of structural integrity can affect the impedance matching and wave absorption performance of HCCs.

Synergistically improving the edge-on impact damage resistance of composite laminates using multi-scale CNF/Z-pin toughening

Edge-on impact damage of composite structures has drawn significant attention from the engineering and academic communities because of the much more notorious damage caused than that by out-of-plane impacts. However, research focusing on improving the edge-on impact resistance of these structures has been limited. This paper proposed a synergistic toughening approach involving multi-scale carbon nanofiber (CNF) and Z-pin to improve the composite laminates' edge-on impact damage resistance. Through analysis of mechanical response, C-scan, optical and Scanning electron microscopy (SEM) photographs of unreinforced, CNF-reinforced, Z-pin-reinforced and CNF/Z-pin-reinforced laminates, the failure mechanisms of the four types of laminates and the synergistic toughening mechanism of CNF/Z-pin were revealed. The results show that the synergistic toughening of CNF/Z-pin could weaken the negative effects caused by Z-pin implantation and that CNF has the potential to increase the damage initiation energy threshold of the laminate. Furthermore, the toughening effect of Z-pin was significantly greater than that of CNF in damage propagation. Specifically, at 50 J impact energy, the damage area of CNF/Z-pin, Z-pin and CNF-reinforced laminates was reduced by 50.5 %, 39.8 %, and 8.3 %, respectively, compared to unreinforced laminates.

Performance prediction method based on Liang-Kleeman information flow and wood tracheid morphology

In order to improve the production efficiency of the wood industry and achieve intelligent feedback control in production processes, non-destructive online prediction of performance is crucial. With the increasing maturity of nanotechnology, the use of scanning electron microscopy (SEM) is becoming increasingly frequent. The Liang Kleeman (L-K) information flow theory is a quantitative causal analysis method based on time series data, which has the advantage of fast calculation. In order to predict the mechanical properties of wood in real-time, fast, and non-destructive manner, this article obtains feature data from SEM photos of wood tracheids, A performance prediction method based on L-K information flow and wood tracheid morphology was proposed. This method first extracts the aspect ratio, wall cavity ratio, double thick wall, and cavity diameter ratio characteristics of wood tracheids from SEM photos, and then calculates the L-K information flow of the tracheid characteristics on mechanical properties (compressive strength, flexural strength, flexural modulus of elasticity, tensile strength). The causal influence strength between them is quantitatively characterized by the coefficient of variation of the L-K information flow, Then, a linear function is constructed with tracheid characteristics as the independent variable, mechanical properties as the dependent variable, and causal influence strength as a coefficient to achieve non-destructive prediction of wood properties. The experimental results show that the highest prediction accuracy of this method reaches 92%, effectively achieving online performance prediction based on causal relationships and image data, providing data reference for screening high-quality performance wood.

Mechanical‐wear behavior and microstructure analysis of Al2214 alloy with B4C and graphite particles hybrid composites

AbstractIn the present work, hybrid composites made of Al2214 alloy with B4C and graphite were produced by using a liquid metallurgical process. Al2214 alloy was utilized to create hybrid composites that had 1.5–6 wt% of B4C particles and a constant 3 wt% of graphite particles. Microstructural analysis using scanning electron microscope (SEM), energy dispersion spectroscopy (EDS), and X‐ray diffraction (XRD) was done on the produced composites. The density, hardness, ultimate, yield strength, and elongation as a percentage were carried out using ASTM E8 for tensile and E10 standard for hardness test. The wear behavior of Al2214‐B4C and graphite composites was examined as per ASTM G99 standard using a wear testing device under a variety of loads and rotation speeds. Graphite and boron carbide particles were equally dispersed throughout the Al2214 alloy, according to SEM photographs. Graphite and B4C particles were detected in the Al2214 alloy by EDS and XRD analyses. The density of Al alloy composites was decreased by adding dual particles to the matrix. The Al2214 alloy's hardness, ultimate strength, yield strength, and wear resistance were all enhanced by the inclusion of dual particles, which increased these properties by 15.4%, 40.4%, and 46.7%, respectively. The presence of hybrid particles in the Al2214 alloy was revealed by EDS and XRD patterns. The density of Al alloy composites was decreased by adding dual particles to the matrix. Tensile force micrographs provided further evidence of the unique fracture behaviors shown by the Al2214 alloy and its composites. In order to examine the wear mechanisms and different morphologies of worn surfaces, scanning electron micrographs were taken.

Efficiency Evaluation and Characterization of Microbially, Phyto and Chemically Synthesized Silver Nanoparticles

The present research objectives involves the synthesis and characterization of microbially, Phyto- and chemically silver nanoparticles (AgNPs) and evaluation the antimicrobial and cytotoxicity effect. Silver nanoparticles were biosynthesized through Streptomyces clavuligerus and Curcuma extract in addition to chemical reduction method with trisodium citrate as reducing agent silver nitrate as the metal substrate. The syntheses of the silver nanoparticles were characterized using UV-Vis spectroscopy and scanning electron microscopy (SEM). The results of characterization revealed absorption peaks obtained at range from 217-222 nm for all AgNPs types. SEM photographs of biosynthesized AgNPs indicate a narrow size distribution with average 8 nm in ‎spherical with smooth surfaces‎ and serruond protein but, chemical AgNPs showed ‎ without serruond protein. Antibacterial activity of AgNPs was determined using agar well diffusion method against Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginos. Results show similar significant antibacterial activity of microbial and Phyto- biosynthesized silver NPs. On the other hand, the chemically synthesized AgNPs recorded no activity against all tested pathogens. The cytotoxicity of AgNPs was tested in vitro on lung tissue fibroblast (WI-38) using MTT with various concentrations. The results recorded IC50 4.6, 1.25 and 2.18 µgml-1 for microbially, Phyto- and chemically AgNPs respectively. Almost all the microbial synthesis of silver nanoparticles exhibit the beast characteristics that qualify it for application in the pharmaceutical field due to its being the smallest in size, antimicrobial activity, and the less toxic on host cells.

The Influence of Salt Erosion on the Mechanical Performances of Ultra-High-Performance Concrete with Secondary Aluminum Dross

Secondary aluminum dross containing a large amount of active substance can be used to prepare concrete. The mechanical strengths, the mass loss rate (MR) and the relative dynamic modulus of elasticity (RME) of ultra-high-performance concrete with secondary aluminum dross are researched. The NaCl freeze–thaw cycles (F-Cs) and dry–wet alternation (D-A) effects with NaCl and Na2SO4 are considered. The corresponding permeability of chloride ions and the carbonation depth (Dc) are obtained. The scanning electron microscope (SEM) photos are researched to reveal the variation of the mechanical mechanism. Results show that after specimens’ suffering from the action of 20 NaCl D-As, the MR of ultra-high-performance concrete is the highest. Specimens exposed to 200 NaCl F-Cs show the lowest MR and CMC. The RME of UHPC under salt actions increase in the order of 20 NaCl D-As < 20 Na2SO4 D-As < 200 NaCl F-Cs. After suffering 200 NaCl F-Cs, 20 Na2SO4 D-As and 20 NaCl D-As, the corresponding Dc values are 1.86 mm to 2.31 mm, 1.79 mm to 2.23 mm and 2.11 mm to 2.76 mm. The flexural strength decreases at the rates of 0.99%–25%, 3.92%–27.84% and 1.47%–21.59% respectively. The MR increases and the RME decreases as the cubic function changes with the amount of salt erosion. After the secondary aluminum dross is added, the CMC decreases at the rates of 0% to 11.53%, 0% to 33.17% and 0% to 8.41% during the process of the salt action. The SAD can reduce the Dc with the decreasing rates of 19.48%, 23.55% and 19.73%. The SAD can increase the compactness of ultra-high-performance concrete. Ultra-high-performance concrete suffering from 20 NaCl D-As shows the largest number and the highest width of cracks. However, when the specimens are exposed to 20 Na2SO4 D-As, the number of cracks is the lowest and the width is the narrowest.

Gold nanoparticle-Enhanced Bioglass: Unveiling In Vitro and In Vivo Bioactivity Characteristics for Advanced Medical Applications

Incorporated gold ions Au into glass with composition 30P2O5–20Ca(OH)2–20ZnO-8.0KF-5B2O3–2.0TiO2 in mol% with 400 ppm (Gold III Chloride trihydrate HAuCl4–3H2O) and 600 ppm (Gold III Chloride trihydrate HAuCl4–3H2O) by using terdiurnal method quenching method. The present glass’s Vicker microhardness, Hv, was determined together with X-ray diffraction (XRD) and differential thermal analysis (DTA). Utilizing a transmission electron microscope (TEM) and a scanning electron microscope (SEM), the gold nanoparticle and microstructure of these glasses were examined. According to the SEM photographs the heat treatment method significantly changed the form of the crystals phase of produced glass-ceramic. The glass-doped Au was verified by TEM to be nanocrystalline, with a spherical form and varying sizes between 14.7 and 16.2 nm. Investigations have been carried out into the bioactivity of the produced glass, including its antibacterial, anti-proliferative/cytotoxic properties against both normal and activated splenic cells In Vitro, and anticancer effects. These findings demonstrated the strongest antibacterial activity against both Gram positive and Gram negative bacteria as well as fungi in the glass doped with 600 parts per million of Au ions. It also demonstrated anti-proliferative/cytotoxicity against normal splenic cells, but had the maximum level of neither cytotoxicity nor proliferative effects on activated splenic cells. According to the data, these produced glasses show promise as possibilities for many medical applications.

Report of three centrohelid heliozoan species (Centroplasthelida Febre-Chevalier et Febre) from new localities in Europe with notes on their distribution.

Raphidocystis marginata (Siemensma, 1981), Raineriophrys echinata (Rainer, 1968), and Pterocystis fortesca (Nicholls, 1983) are heliozoan protists, have been recorded only in a few localities in Europe, and considered to be rare species. These centrohelid heliozoans have been reported for the first time in Ukrainian Polissia, and we provide their morphological descriptions with new morphometric data of exoskeleton (periplast) based on Ukrainian material. The diagnostic morphological characters are illustrated by light and scanning electron microscope photographs. Their geographical distribution in Europe and biotope preference are discussed.

Enhancement effect of Li addition on nitriding reaction and combustion of Al-Li alloy in N2

For aluminum-based alloy particles, the addition of alloying element lithium (Li) with the properties of a high chemical activity and a low melting/boiling point can significantly improve the thermo-reactive properties of aluminum (Al) particles. To further reveal the combustion mechanism, this paper presents the nitriding reaction and combustion characteristics of Al-Li alloy in nitrogen (N2) through thermogravimetric analysis and differential scanning calorimetry (TG-DSC) analysis at a low heating rate and laser-induced ignition experiments at a high heating rate, considering the influences of two kinds of Li contents (1.0 wt% @ Al-1.0Li and 2.5 wt% @ Al-2.5Li) on these characteristics and making a comparison to the counterpart Al. Al-Li alloy powders as-prepared by gas atomization method showed the texture of the Li-rich eutectic phase compounds on the surface by scanning electron microscope (SEM) characterization. The TG-DSC results demonstrated that the thermal nitriding reaction of Al-Li alloy in N2 was significantly faster than that of pure Al. The nitriding reaction temperature decreased from 853 °C for pure Al to 245 °C for Al-2.5Li alloy with a reduction of 71 %. The final weight gain of Al-2.5Li alloy was almost three times higher than that of pure Al in N2. The SEM photograph of intermediate nitriding products revealed that the cracks and loose “island” structures in the Li-rich zone on the Al-Li surface were the key to preventing the formation of a “passivation effect” into Al and promoting N2 uptake during melting. In addition, Li also acts as a catalytic carrier and “oxygen absorber” to enhance the Al-N reaction. The combustion of single Al-Li alloy microparticles induced by laser showed two stages: preheating and rapid nitriding. Al-Li alloy particles were ignited more rapidly and showed typical gas-phase / surface combustion modes different from pure Al. According to these findings, the combustion mechanism was proposed to help guide the development of Al-based solid propellants containing Li and the synthesis of AlN/Al composites in nitrogen-rich environments.

Determination of ultrasructural changes in the enamel of primary teeth in starting phases of early childhood caries, with and without local fluoride therapy

Early childhood caries is often found under the name connected with the manner of feeding nutrition of children such as “Baby bottle Syndrome” or “Baby bottle caries”. The aim of the study was to determine ultrastructural changes in the enamel of primary teeth in starting phases of early childhood caries, with and without local fluoride therapy, because it has of great influence in the preventive aspect of the disease. The investigation was done on laboratory tests on tree groups extracted primary teeth: one of 20 healthy mandibular incisors, as control group and two more groups of primary tested teeth: 10 maxillary incisors with initial lesion and 10 maxillary incisors with superficial form. The all dental samples were observed with Scanning Electron Microscope (SEM) and we made comparative analyzes in ultrastructural changes of enamel between untreated and treated teeth, and control group teeth. After that, we have analysis with SEM photo attachments. In some dental samples with initial lesion after local treatmant we managed to get almost healthy enamel, i.e. complete remineralization process. Once again, we have confirmation of one of the many benefits of fluoride in dentistry which is long been known.

Inhibitory effect of UV and gamma radiation for fungal biodeterioration of concrete: A short-term study for sustainable conservation

The conservation of concrete-based deteriorated heritage buildings is a big challenging issue worldwide including in India. This study focused on to prevent fungal biodeterioration in concrete using UVC and gamma radiation. M20 graded concrete cubes (5 cm × 5 cm × 5 cm) were infected with Aspergillus tamarii, which was isolated from a 200 years old historic heritage building. M20 signifies a mixture of cement, sand and aggregate (1:1.5:3), made in such a way that the concrete cube has a compressive strength of 20 N/mm2 when examined after 28 days of curing. The fungal growth appeared clearly as calcium oxalate crystals in the Scanning Electron Microscope (SEM) photographs. Several doses of UVC and gamma radiation were applied on concrete cube. The changes in concrete properties were examined after 30 days in terms of weight, compressive strength, Fourier Transform Infrared Spectroscopy (FTIR) and micro Energy Dispersive X-ray Fluorescence (EDXRF). The results exhibited that compressive strength of control (non-infected and non-irradiated), biodeteriorated (infected), UVC (625 µw/cm² × 300 s) and gamma (0.5 KGy) irradiated infected (inhibition) concrete cubes were 19.74 ± 0.46, 18.88 ± 0.43, 20.20 ± 0.34 and 19.93 ± 0.20 N/mm2 respectively whereas negligible weight losses were observed for inhibition cubes compared to biodeteriorated ones. Calcite (1400, 874 and 705 cm−1), one of the major functional band present in concrete became weak after getting infected by Aspergillus tamarii and strong for inhibition samples irradiated with the above doses. The EDXRF analysis exhibited that mass percentage of calcium ions of the biodeteriorated concrete cubes (49.88 ± 0.65%) was lower than that of UV (75.75 ± 0.16%) and gamma (70.95 ± 0.30%) irradiated infected or inhibition concrete cubes. Altogether, the efficacy of the recommended inhibitory dose of ultraviolet and gamma radiation against concrete deterioration in the field of conservation of heritage building was observed to be positive.

Crystal structures and microwave dielectric properties of (1-x)Ba(Zn1/3Nb2/3)O3 − xBaWO4 (0 ≤ x ≤ 0.25) ceramics

The (1-x)Ba(Zn1/3Nb2/3)O3 − xBaWO4 (0 ≤ x ≤ 0.25) ceramics were manufactured by the conventional solid-phase reaction process, and the effects of BaWO4 addition on the phase composition, crystal structures, microstructure, and microwave dielectric properties were investigated. X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy were implemented to explore the phase composition, crystal structure and chemical states of the samples, respectively. According to XRD analysis, the main phase of the samples was assigned as Ba(Zn1/3Nb2/3)O3 (BZN), while the secondary phases contained Ba5Nb4O15 and BaWO4. Scanning electron microscopy photographs suggested the average grain size firstly increased and then decreased with the replacement of W6+ ions to Nb5+ ions in BZN. Due to the proper substitution amount of W6+, the apparent density increased accordingly. The microwave dielectric properties were closely associated with the secondary phases and apparent density. Finally, (1-x)Ba(Zn1/3Nb2/3)O3 − xBaWO4 (x = 0.15) ceramics sintered at 1325 °C for 4 h had excellent microwave dielectric properties with ε r = 33.11, Q × f = 90,479 GHz, and τ f = +0.86 ppm °C−1.

Electrochemical synthesis of conjugated copolymer poly(3-hexylthiophene-co-dithenopyrrole): Stepwise approach to enhance electro-optical properties

Electrochemical polymerisation of 3-hexylthiophene (3HT) and electrochemical copolymerisation of 3HT and N-benzoyl dithienopyrrole (BDP) were performed to prepare polymer and copolymer films using a linear sweep voltammetry potentiostatic technique with a voltage range from 1.7-1.8 V and a scan rate of 0.1 mV/s. Cyclic voltammetry (CV) curves, Fourier-transform infrared (FTIR) spectra, scanning electron microscope (SEM) images, and UV-Vis absorption spectra of the polymer and copolymer were recorded for analysis and comparison of the electropolymerisation process and properties of the resultant films. The SEM photographs of the copolymer base on 3HT and BDP exhibited a rigid structure with large spherical aggregates with an average size around 200 nm. The copolymer of 3HT and BDP exhibited the band gaps of 2.25 eV which was determined via electrochemical measurement that is higher than of band gaps of homopolymer poly(3-hexylthiophene) (P3HT). The copolymer’s energy bandgap HOMO-LUMO was enhanced compared to polymer P3HT. Moreover, the increased conjugation length significantly improved the morphology structure as well as the electrochemical stability of the conjugated copolymer.

Thermal behavior of La3+, Ni2+ and Sn4+ co-doped CaCu3Ti4O12 ceramics dielectric response

Dielectric properties control by elements co-doping is important research problem for application of ceramics based on CaCu3Ti4O12 (CCTO) as a component of electronic devices. In this work, the effect of La3+, Ni2+ and Sn4+ co-doping on the dielectric properties of CCTO ceramics, including their thermal stability, was investigated. Solid solutions with compositions of Ca1-xLa2x/3Cu2.95Ni0.05Ti3.7Sn0.3O12 (x = 0.010–0.055), Ca0.94La0.027Cu3-yNiyTi3.7Sn0.3O12 (y = 0.020–0.065), Ca0.94La0.027Cu2.95Ni0.05Ti4-zSnzO12 (z = 0.25–0.4) were synthesized by the solid-state method at 970 °C. The incorporation of doping elements into the ceramic structure after sintering at 1080 °C was confirmed by X-ray diffraction data. Grain morphology and size of various solid solutions were estimated from scanning electron microscopy photographs. The optimal concentrations of doping elements were x = 0.04, y = 0.05, and z = 0.3, which is evident by high permittivity ε′ = 11,000 and low dielectric losses tanδ = 0.051 at f = 1 kHz. La3+, Ni2+ and Sn4+ co-doped CCTO ceramics demonstrated high stability of the permittivity in the temperature range from −60 to +125 °C. Based on the demonstrated dielectric properties, the presented solid solutions are suitable for use in ceramic capacitors.

Method for taking Scanning Electron Microscope photographs of nematodes and meiofauna with the support of a low-cost and easy-made container.

This paper presents a method for capturing Scanning Electron Microscope (SEM) photographs of small specimens, including nematodes, arthropods, small insects, and other meiofauna. Our method is tailored to handle nematode specimens mounted on permanent slides, an area with relatively limited documentation. Besides, the process of transferring such delicate specimens from one solution to another has historically posed numerous challenges. To address this issue, we introduce a low-cost and easy-made container designed specifically to facilitate the aforementioned procedure, with a particular focus on SEM photography. The newly introduced container offers a practical solution that enhances the efficiency and effectiveness of specimen handling, ultimately enabling high-quality SEM imaging. This method holds significant promise for researchers working in the field of micro-scopic organism analysis, providing a valuable tool for their investigations with minimum cost.

Quantity and diameter of dentinal tubules of human teeth and teeth of experimental animals according to scanning electron microscopy data

Insight into the interrelation between the structure and mechanical properties of dentin of a tooth is crucial for prevention and treatment of oral cavity diseases. The study of the structure of dental dentin is important for understanding the pathogenetic mechanisms of the spread of cariogenic microflora in progressive dental caries to the pulp and periodontium, as well as for the interpretation of the results of studies of dental dentin-adhesive materials. The in vitro research presented here involved the examination of coronal dentin in 46 intact teeth from rats, cats, dogs, and humans at various distances from the pulp chamber, with a focus on the quantity and diameter of dentinal tubules. The calculations were based on the analysis of 155 scanning electron microscope photographs of the enamel surface and pulp chamber wall. The researchers calculated the quantity and diameter of dentinal tubules per unit area, which they measured at various distances from the pulp chamber. It was found that dentinal tubules are the widest near the pulp chamber wall, where the average diameter ranged from 1.7 to 2.8 µm. The highest values were found in premolars of young humans and the lowest - in the incisors of rats. In the middle portion of the dentin, the diameter of dentinal tubules ranged from 1.0 to 13.3 µm, while at the periphery, it was 0.6–0.9 µm. The highest density of dentinal tubules per unit area was found closest to the pulp horn, and the lowest was in the enamel region. Near the pulp chamber wall, the average density of dentinal tubules ranged from 50 000 to 90 000/mm², in the middle of the dentin, it ranged from 37 000 to 50 000/mm², and at the periphery, it ranged from 10 000 to 25 000/mm². All examined teeth exhibited straight dentinal tubules, except for the rats’ incisors, which showed local irregularities. A comparison was made based on the quantity and width of dentinal tubules in the examined animals and humans.

Immature stages of Phloeosinus tacubayae (Curculionidae: Scolytinae): morphology and chaetotaxy of larva and pupa, sexual dimorphism of adults, and developmental time.

The current knowledge of morphology and chaetotaxy of the different developmental stages within the subfamily Scolytinae presents an information deficit that needs to be addressed. Thus, the objective of the present study was to describe, the chaetotaxy and morphology of larvae and pupae, and determine the number of larval instars, the sexual dimorphism in adults, and the development time in Phloeosinus tacubayae. The number of larval instars was determined using traditional morphometry of cephalic capsule and multivariate analysis; description of morphology and chaetotaxy of larvae and pupae, and sexual dimorphism in adults was based on light microscopy and scanning electron microscopy photographs; finally, we quantified development time by mean reviews of 10 gallery systems selected randomly in infested logs, in the laboratory. Morphometric analysis of the cephalic capsule allowed the recognition of 3 different instars. Our results showed that the larvae of P. tacubayae have unique attributes in the body that differentiate them from other genera of the subfamily for example the epicranial suture is not marked, and differentiated from Phloeosinus canadensis, such as a smaller number of setae in the maxillae and without a tergal plate. The pupa had a smaller number of setae on the whole body. The most useful morphological characters to identify a sexual dimorphism in adults were found in the shape and relative position of the seventh and eighth tergites; development time lasted 40 days in total, being the pupal stage the one that took the longest to complete.

Chemical, electrochemical and morphology studies of three di-cationic amphiphiles and their applications: Corrosion inhibitors for carbon steel in formation water during gas and oil production and as broad antimicrobial agents against standard microbial strains

In the present work, the previously synthesized di-cationic amphiphiles surfactants have displayed an excellent surface attitude in formation water, according to surface tension findings. The three di-cationic amphiphiles surfactants (CSI, CSII, and CSIII) were tested as corrosion inhibitors for carbon steel (CS) in the formation water during gas and oil production using weight loss (WL), Tafel polarization (TP) and electrochemical impedance spectroscopy (EIS) and surface morphology using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The obtained results demonstrated that the di-cationic amphiphiles surfactants are good corrosion inhibitors in the formation water.As the concentration of the inhibitors increased, the effectiveness of the dissuasion increased. The Tafel polarization results showed that, corrosion current densities (icorr) decreased whereas inhibition effecenicy (ηp) increased as the inhibitor concentration increased. EIS results showed that, the constant phase element (CPE) values decreased and the polarization resistance (RP) values increased with increasing the inhibitor concentrations. SEM & AFM photos exhibited a good CS surface in presence of the CSI, CSII & CSIII in opposite of the absence of them. Furthermore, the three di-cationic amphiphiles surfactants (CSI, CSII, and CSIII) were applied as broad antimicrobial agents against standard microbial strains (bacterial and candida strains). Results demonstrated a great broad antimicrobial activity of the three di-cationic amphiphiles surfactants with a zone of inhibitions ranging from (15–30) mm for the bacterial strains and (25–30) mm for the candida standard stain in comparison to the positive control antimicrobial agents. Moreover, the CSI, CSII & CSIII have displayed the highest antibacterial efficiency against the Gram-positive (27–30 mm) than the Gram-negative bacterial strains (15–19 mm).