Average Outer Diameter Research Articles

Retinal arteriolar wall-to-lumen ratios at 16–17 years in the Copenhagen Child Cohort 2000 Study

To study the thickness of retinal arteriolar walls in a population-based cohort of adolescents. This cross-sectional, observational study included 1217 participants aged 16-17 years from the Copenhagen Child Cohort 2000 Study. The wall thickness and lumen diameter of a major branch retinal arteriole were measured using adaptive optics imaging. The wall-to-lumen ratio was analyzed in relation to blood pressure and body composition variables using a general linear model. Overall in the study population, wall-to-lumen ratio was found to decrease by 0.49% per μm increase in arteriole diameter (P < 0.0001) and all subsequent analyzes were adjusted accordingly. The average outer and inner arteriole diameters were 117 ± 19 and 96.6 ± 18 μm (mean ± SD), corresponding to a wall-to-lumen ratio of 0.21 ± 0.024. There was no detectable difference between sexes. A higher wall-to-lumen ratio was associated with a higher BMI (+0.21% per kg/m, P = 0.0018), higher body fat percentage (+0.097% per 1% increase, P = 0.0052), wider hip circumference (+1.1% per 10 cm increase, P = 0.0006), wider waist circumference (+0.92% per 10 cm increase, P = 0.0009), higher SBP in girls (+1.1% per 10 mmHg increase, P = 0.0005), longer axial length (+0.70% per mm increase, P = 0.013), and younger age (+4.9% per year younger, P < 0.0001), adjusted for arteriole diameter, age, sex, and height. A higher retinal arteriolar wall-to-lumen ratio was associated with all registered indices of body fat proportion.

Thermal Analyses of Loose Agave, Wheat Straw Fibers and Agave/Wheat Straw as New Hybrid Thermal Insulating Materials for Buildings

ABSTRACT Agave (AF) and wheat straw (SF) fibers are good raw materials for thermal insulation. In this study, loose agave or wheat straw fibers and hybrid boards of agave/wheat straw with different compositions and densities are tested for their thermal insulation qualities. Three new novel hybrid specimens are considered. In all specimens, cornstarch (CS) was used as a binder for the fibers. Thermal conductivity coefficient is obtained for each specimen in the temperature range 10–60°C with the resulting average value in the range 0.04555–0.06835 W/m K. Without binding, loose fibers of agave and wheat straws have an average thermal conductivity of 0.043592 and 0.044678 W/m.K, respectively, at the same range of temperature. Micrographs of the wheat straw fibers (SF) are conducted using the scanning electron microscope (SEM) which showed an average outer diameter between 1.28 and 1.98 mm and an average diameter of the bound porous tubes (multicellular) within the straw in the range 34.5 to 75.6 μm. Fourier transformation infrared (FT-IR) analyses of the wheat straw fiber are carried out which indicated stretching wavenumbers which present different chemical functional groups. Thermogravimetric analysis of the wheat straw fiber (TGA and DTGA) showed that the straws lose less than 3% of its mass at temperatures as high as 184°. Finally, the differential scanning calorimetry (DSC) analysis test of the wheat straw fiber indicates that endothermic transition starts at 342°C with a peak value at 749°C. Three-point bending moment tests for bound specimens are made and show an increase in both flexural stress and flexural modulus of the hybrid specimens. Using these hybrid specimens, agro, renewable and environmentally friendly materials in buildings will share in energy saving when used as insulation materials for building walls.

Magnetic Vortex and Hyperthermia Suppression in Multigrain Iron Oxide Nanorings

Single-crystal iron oxide nanorings have been proposed as a promising candidate for magnetic hyperthermia application because of their unique shape-induced vortex-domain structure, which supports good colloidal stability and enhanced magnetic properties. However, the synthesis of single crystalline iron oxide has proven to be challenging. In this article, we showed that chemically synthesized multigrain magnetite nanorings disfavor a shape-induced magnetic vortex-domain structure. Our results indicate that the multigrain Fe3O4 nanorings with an average outer diameter of ~110 nm and an inner to outer diameter ratio of ~0.5 do not show a shape-induced vortex-domain structure, which was observed in the single-crystal Fe3O4 nanorings of similar dimensions. At 300 Ks, multigrain magnetite nanorings showed an effective anisotropy field of 440 Oe, which can be attributed to its high surface area and intraparticle interaction. Both calorimetric and AC loop measurements showed a moderate inductive heating efficiency of multigrain magnetite nanorings of ~300 W/g at 800 Oe. Our results shed light on the magnetic ground states of chemically synthesized multigrain Fe3O4 nanorings.

The applied anatomy and clinical significance of the proximal, V1 segment of vertebral artery.

The aim of the study was to probe the morphological features of the proximal segment (V1) of vertebral artery (VA) in a sample of Chinese cadavers. The origin, course and outer diameter at origin of the pre-vertebral part of the VAs were evaluated in 119 adult cadavers. It was found that 94.12% of the VAs originated from the subclavian arteries, bilaterally. The variant origins were present in 5.88% of the cadavers and all originated directly from the arch of the aorta. All the variations were observed on the left side of male cadavers. The average outer diameters at origin of the normal and variation groups were 4.35 ± 1.00 mm and 4.82 ± ± 1.42 mm, respectively, p = 0.035. In the normal group, but not in the variation group, the average diameter in the males was significantly larger than that in the females (4.50 ± 0.99 mm, 3.92 ± 0.92 mm, respectively, p = 0.000). In addition, only 5 cadavers in the normal group had hypoplastic VAs (4.20%, 4 males, 3 right-sided). Vertebral artery dominance (VAD) was present in 91 (69 males) out of 112 cadavers and more common on the left (n = 48). In addition, 3 cadavers satisfied conditions for coexistence of VAD and vertebral artery hypoplasia. All 7 cadavers in the variation group exhibited VAD, which was more common on the right side (n = 5). The morphologic variations and frequencies described above have implications for the early prevention, abnormal anatomy detection, accurate diagnosis, safe surgery and endovascular treatment of cardiovascular and neurological disease.

92 Using physical parameters of bovine zygotes to predict invitro development success

The objective of this study was to determine if physical parameters of bovine zygotes are correlated with invitro development success. We examined the relationship between a zygote's outer diameter (OD), cell area, and zona pellucida (ZP) thickness on blastocyst development and blastomere number. Bovine cumulus-oocyte complexes, from abattoir-derived ovaries, were matured in tissue culture medium 199-based maturation medium for 21-23h. Invitro fertilisation was performed with frozen thawed semen containing a pool of 4 Holstein bulls. After incubation with sperm for 16-18h, presumptive zygotes (n=875) were denuded and placed in 5µL droplets of synthetic oviductal fluid-bovine embryo 1 medium (SOF-BE1) under oil to be individually photographed using an inverted scope with a digital camera. Zygotes were then group-cultured in 50µL of synthetic oviductal fluid-BE1 droplets in a polyester micromesh to identify individuals. Development to the blastocyst stage was recorded on Day 7 and Day 8 of culture, and Day 8 embryos were fixed and stained with Hoechst 33342 (n=87). ImageJ was used to measure the OD, area, and ZP from images. Data were analysed with a logistic regression using the lme4 package in R with Day 7 or Day 8 blastocyst development as the response; OD, area, and ZP as predictors; and study replicate (n=11) and culture droplet as random effects. Residual estimates of area and ZP calculated from OD were used to account for collinearity. Average OD was 151.2µm, ranging 130.4-171.6µm. Average ZP was 11.8µm, ranging 7.2-17.5µm. Area averaged 9856.7µm2, ranging from 6421.9 to 13 814.8 µm2. There was a tendency for an effect of OD on probability of development on Day 8 (P=0.08) but not Day 7. There was an effect of ZP on the probability of development on Day 8 (P=0.04) but not Day 7. Blastocyst rates on Day 8 for zygotes with ZP &amp;lt;11.8µm were 24.3%, whereas zygotes with ZP &amp;gt;11.8µm were 21.7%. There was an interaction (P&amp;lt;0.05) between OD and ZP thickness on Day 7 and Day 8. Estimated probability of development of zygotes with ZP &amp;lt;10.7µm and OD &amp;lt;146.9µm averaged 28.5%, whereas those with ZP &amp;gt;12.7µm and OD &amp;gt;155.8µm averaged 43.3%. The observed blastocyst rates for these two groups were 26.2% and 25%, respectively. Zygotes with OD between 146.9-155.8µm and ZP between 10.7-12.7µm had an estimated development probability of 22.2%. The obtained Day 8 blastocyst rate for this group was 22.5%. Area did not affect probability of development, but was positively correlated with total blastomere number at Day 8 (P=0.01; marginal R2=0.09). The observed interaction between ZP thickness and OD may be indicative of an optimum ooplasm area before maturation or fertilisation that may enhance development. Area assessment after fertilisation is not correlated with development success. In addition, these data in comparison with our previous data generated in parthenogenetic embryos indicate that artificial activation of oocytes is not an ideal model in place of IVF for studying development. We continue to demonstrate that physical parameters of zygotes may have potential as a noninvasive, objective selection tool of embryos.

Hydrothermal synthesis and ethanol-sensing properties of α-Fe2O3 hollow nanospindles

Iron oxide nanostructures have been studied extensively because of their magnetic, optical, electrical, and catalytic properties. In this work, uniform α-Fe2O3 hollow nanospindles were synthesized through hydrothermal method. The average length and outer diameters of the nanospindles are 300 sand 100 nm, respectively. The hollow spindles’ dimensions can be tailored by varying the treatment duration. A growth mechanism of the α-Fe2O3 hollow nanospindle is discussed. Furthermore, the ethanol-sensing properties of the as-synthesized material are investigated at different gas concentrations (25–300 ppm) and operating temperatures (200–400 °C). The sensing output indicates that the α-Fe2O3 hollow nanospindles are an excellent ethanol-sensing material, which can be developed further for practical application.

Synthesis by anodisation method, characterization by SEM and EDS, and degradable ability of TiO2 nanotubes.

Obtaining of TiO2 nanotubes could be performed by anodized Ti in fluoride based electrolyte. During the growth of TiO2 nanotubes within the influence of anodizing process of Ti, a certain parameters are required, electrolyte composition, voltage, and time. The TiO2 nanotube array was synthesized electrochemically in a fluoride containing electrolyte by anodisation method of a pure titanium plate. The anodisation procedure was carried out in ethylene glycol electrolyte; the applied voltage was 60 volt. The average inner diameter of the nanotube was (67 nm) and the average outer diameter was (80 nm). Characterization of the nanotubes crystal structure, morphology, and oxide composition were performed via field emission scanning electron microscopy (FE-SEM) and energy dispersion spectroscopy (EDS). Elemental analysis by EDS shows the presence of fluoride, and confirm the formation of TiO2 nanotubes. The results show the possibility of study the distribution of the composition of the tubes elements using the scanning electron microscope-mapping. Synthesized TiO2 nanotubes were applied for the degradation of organic dye methylene blue as water dye pollutant. It is found that rate of degradation of MB in presence of TiO2 nanotubes was greater than in case of degradation without TiO2 nanotubes. It is clear that the main reason for this behavior belongs to the high surface area of TiO2 nanotubes. For (5) ppm of methylene blue, the degradation in presence of TiO2 nanotubes has done completely after (5 hours)

Magnetic hydroxyapatite nanotubes on micro-arc oxidized titanium for drug loading

A novel coating which comprised magnetic hydroxyapatite (HA) nanotubes as an outer layer and porous TiO2 as the inner layer was fabricated on Ti by a hybrid process of micro arc oxidation (MAO), hydrothermal treatment (HT) and electrochemical treatment (ET). The microstructure of HA nanorods after HT was investigated, and their morphology evolution from nanorods to nanotubes by prolonging ET was observed. The formation mechanism of HA nanotubes was explored, and magnetism property of the composite coating was evaluated. Monocrystallized HA nanorods doped with 1.19 At% Fe were initially formed on microporous TiO2 by MAO and HT, and they had a mean diameter of 300 nm. The mismatching between Ca and Fe ions induced some lattice distortions on the basal-faceted surfaces of HA. During ET process, Na+ and H+ ions should concentrate on the negatively charged basal planes of HA inducing further lattice distortion and local dissolution. By prolonging the ET process, dissolution of basal planes increased, resulting in the formation of HA nanotubes with an average outer diameter of about 300 nm, and wall thickness of about 30 nm. The composite coating showed magnetism behavior with a value of 0.3 emu g−1 at applied field of 4 T. A strategy to fabricate a magnetic HA nanotube coating on Ti was given, and the unique nanostructure should have a potential application in drug loading.

REACTIVE CHANGES IN THE RESISTIVE OF THE HEMOMYCOCIRCULATORY BED FOLLOWING THE ACTION OF 1% OF METHACRYLIC ACID ESTER

The morphometric study conducted has revealed that the effect of a 1% methacrylic acid-methyl ester solution affects the resistive section of the microvasculatory bed of the submandibular salivary gland lobes. The study was conducted on 30 white outbred male rats, 10 of which made up the control group of animals and 20 animals made up experimental group, whose oral mucosa was treated with 1% methacrylic acid-methyl ester solution for 30 days. After euthanasia of animals in 14 and 30 days, samples of the submandibular gland were embedded into epon-812. Semi-thin sections were stained with polychrome dye. A quantitative analysis of the results of the morphometric study and statistical processing of the morphometric data was performed using standard statistical methods using the Excel program. The outer diameter and lumen diameter of arterioles were measured. The thickness of the vascular wall was calculated using the formula VWTh = Dz-Dt / 2. On the 14th day, in response to the action of 1% methacrylic acid-methyl ester solution, the average outer arteriole diameter decreased by 13.04%, the diameter of the of arteriole lumen by 20.77%. There is a significant increase in the average thickness of the vascular wall by 5.45%, the value of which was 2.90 microns. On the 13th day of the study, it was found out that the average values ​​of the outer diameter of the arterioles increased by 5.04% (p &lt;0.05), compared with the control group. The lumen diameter was significantly larger by 15% that the values ​​in the control group of animals, and the average vascular wall thickness was significantly lower by 18.91% than the values ​​in the control group of animals (p &lt;0.05). Normalization of indicators for the 30th day has not been defined. Thus, the effect of 1% methacrylic acid-methyl ester solution on the arterioles of the submandibular salivary gland lobes is characterized by vascular spasms in the early stages, and vascular dilatation in the later stages of the experiment.

Establishment of experimental model for saphenous artery perforator flap in mini pig

Objective To investigate the anatomy characteristics of saphenous artery(SA) and its perforator vessels in mini pig, and to provide a new perforator flap animal model. Methods Between May, 2018 and August, 2018, 6 7-months-old mini pigs weight 25 kilograms were sacrificed by blooding under general anesthesia. The bilateral external iliac arteries were injected with a mixture of latex-lead oxide mixture and underwent CT-scanning to provide 3-dimensional reconstruction. The origin, diameter, courses and distribution of the SA and perforators of both hind limbs were observed. Results One of the hind limbs was abandoned due to the leakage of perfusion fluid. The other 11 hind limbs were available. The femoral artery passed through the medial femoral muscle and sartorius muscle in the middle of thigh, and run between the medial femoral muscle and gracilis muscle above the knee. Below the knee, it run on the surface of the medial leg muscles. A number of small branches were distributed in the tarsal joint and calcaneus at the medial malleolus, and there were abundant communicating branches with the posterior tibial artery. The average length of SA was (14.86±0.76) mm. The outer diameters of SA at initiative, medial tibial condyle and medial malleolus were(1.73±0.15) mm, (1.50±0.12) mm and (1.30±0.13) mm, respectively. There were a total of 79 perforators which were identified, with a mean of (7.09±1.16) perforators per hind limbs. And the average outer diameter was 0.10-0.78 (0.40±0.13) mm. Conclusion The SA constantly exist with good outer diameter. The number of perforator is abundant. SA can be used as a reliable animal model for studying and training of perforator flap. Key words: Saphenous artery; Perforator flap; Mini pig; Animal model

A Micro Peristaltic Pump Using an Optically Controllable Bioactuator

Abstract Peristalsis is widely seen in nature, as this pumping action is important in digestive systems for conveying sustenance to every corner of the body. In this paper, we propose a muscle-powered tubular micro pump that provides peristaltic transport. We utilized Drosophila melanogaster larvae that express channelrhodopsin-2 (ChR2) on the cell membrane of skeletal muscles to obtain light-responsive muscle tissues. The larvae were forced to contract with blue light stimulation. While changing the speed of the propagating light stimulation, we observed displacement on the surface of the contractile muscle tissues. We obtained peristaltic pumps from the larvae by dissecting them into tubular structures. The average inner diameter of the tubular structures was about 400 μm and the average outer diameter was about 750 μm. Contractions of this tubular structure could be controlled with the same blue light stimulation. To make the inner flow visible, we placed microbeads into the peristaltic pump, and thus determined that the pump could transport microbeads at a speed of 120 μm·s−1.

Halloysite nanotubes as tools to improve the actual challenge of fixed doses combinations in tuberculosis treatment.

Halloysite nanotubes (HLNTs) were used as nanocarriers of the tuberculostatic agent isoniazid (INH), a BCS (Biopharmaceutics Classification System) class III drug. Self-assembling nanohybrids (INH-loaded HLNTs) with an average outer diameter of 90 nm and polydispersity index of 0.7 approximately, were obtained by spontaneous adsorption of INH molecules to HLNTs powder in aqueous medium. The nanohybrids were aimed to improve oral drug bioavailability and reduce physicochemical incompatibility of INH with other concomitantly administered tuberculostatic agents. In vitro drug release from INH-loaded HLNTs was successfully fitted to a diffusive kinetic law founded on the adsorption-desorption equilibrium between drug molecules in solution and solid inorganic excipients. INH-loaded HLNTs showed good in vitro biocompatibility toward Caco-2 cells at the concentrations studied (up to 1233 μg/mL), with improved cell proliferation. Permeability tests showed that INH transport across Caco-2 cellular membranes was greatly enhanced and fluorescent microscopy confirmed that the drug encapsulated into nanohybrid was effectively internalized by the cells. INH-loaded HLNTs enhanced stability of the drug in presence of other tuberculostatic agents, both in binary and quaternary combinations. It has been demonstrated that simple interaction between INH with HLNTs leads to drug permeability and stability improvements that could greatly facilitate the design of multiple drug dosage forms, an actual challenge in oral treatment of tuberculosis. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Data mining to predict the average outer diameter of vertically aligned TiO2 nanotubes

Nowadays, the development of new technology is strongly based on nanomaterials studies, such as vertically aligned TiO2 nanotubes (TONTs), which are widely used in different fields of industry. Physical properties of these materials depend on their size (inner and outer diameters) and shape, for this reason they must be measured accurately. Inner and outer diameter measurement is performed manually on images obtained by means of scanning electron microscopy. Time-consuming image analysis, subjective and low-representative readings are some disadvantages found in this process. This paper proposes a model to predict the average outer diameter of TONTs using Data Mining and Ellipsometry, because they have the potential to overcome disadvantages mentioned above. The diameter with measurements of light reflection intensity and ellipsometric parameters is modelled using different techniques. A model that shows a very low prediction error using linear support vector machines for regression is reported.

Incidence of vertebral artery of aortic arch origin, its level of entry into transverse foramen, length, diameter and clinical significance.

The aim of this study was to show the incidence of vertebral artery of aortic arch origin, its level of entry into transverse foramen, including extra- and intracranial morphometry, and clinical significance. A total of 266 embalmed cadavers were studied. We found 14 left vertebral arteries (5.3%) emerging from aortic arch. Most of the left vertebral arteries of aortic arch origin (78.6%) entered the fifth cervical transverse foramina, whereas most of the vertebral arteries of subclavian origin (94.7% left and 99.2% right) entered the sixth cervical transverse foramina. Their average prevertebral length was 8.24 ± 1.09cm ,which was about twice as long as the right vertebral artery (3.88 ± 1.14cm). The average outer diameters of the prevertebral part and ensuing intracranial part of the left vertebral artery of aortic arch origin were 4.36 ± 0.93 and 3.62 ± 0.62mm, respectively. The mean corresponding diameters of the vertebral artery of subclavian origin were 5.06 ± 1.04 and 3.87 ± 0.83mm, respectively. All of the vertebral arteries decreased significantly in size after entering the cranial cavity. The reduction in caliber of the intracranial part of the vertebral artery compared with the prevertebral part of its own vessel has never been reported elsewhere. Knowledge of such anatomical variations is important in interpreting CT angiography, anterior cervical decompression and aortic arch surgery to prevent iatrogenic injury of the vertebral artery.

Dry-pressed anodized titania nanotube/CH3NH3PbI3 single crystal heterojunctions: The beneficial role of N doping

Highly ordered, anodically grown TiO2 nanotubes on titanium supports were annealed in ammonia atmosphere in order to incorporate nitrogen doping (≤2 at.%) in the titanium oxide lattice. FESEM micrographs revealed nanotubes with an average outer diameter of 101.5 ± 1.5 nm and an average wall thickness of about 13 nm. Anatase crystals were formed inside the tubes after annealing in ammonia atmosphere for 30 min. With further annealing, rutile peaks appeared due to the thermal oxidation of the foil and rise as the duration of heat treatment was increased. The concentration and chemical nature of nitrogen in the nanotube arrays can be correlated to the optical response of dry-pressed heterojunctions of doped TiO2/CH3NH3PbI3 single crystals. The N-TiO2/perovskite heterojunction with the highest amount of interstitial nitrogen exhibited an improved photocurrent, indicating the importance of the semiconductor doping-based heterojunction optimization strategies to deliver competitive levels of halide perovskite-based optoelectronic devices to be envisioned for urban infrastructures.

Production of bundled CNTs by floating a compound catalyst in an atmospheric pressure horizontal CVD reactor

Abstract Although floating catalyst CVD is an economical and flexible technique for production of carbon nanotubes (CNTs), scant information is available on production of bundled CNTs using this technique. In this study, multiwalled carbon nanotubes (MWCNTs) were grown in bundles by cracking ethylene molecules over Fe2O3/Al2O3 compound catalyst in a floating catalyst CVD reactor. The process temperature and catalyst weight were varied from 700 °C to 850 °C and 0.1 g to 0.5 g, respectively. The as-synthesized CNT bundles were characterized for their surface morphology, multi-layered structures, diameter distribution, chemical composition, elemental mapping, and crystallinity. The results showed the formation of CNT forest over Fe2O3/Al2O3 catalyst. The denseness of the forest varied with process temperature and catalyst weight. The product yield varies from 48% to 93%, depending on the process temperature and catalyst weight. The maximum yield and crystallinity of nanotubes were reported for process temperature of 800 °C and catalyst weight of 0.3 g. The Raman analysis of the product showed the lowest ID/IG ratio of 0.78 under optimized conditions. The average outer diameter of CNT bundles remained between 240 nm and 550 nm. The outer diameter of individual tubes was measured between 40 nm and 100 nm.

Folate-Functionalized Mesoporous Hollow SnO2 Nanofibers as a Targeting Drug Carrier to Improve the Antitumor Effect of Paclitaxel for Liver Cancer Therapy.

In this study, we prepared PTX-loaded mesoporous hollow SnO2 nanofibers conjugated with folic acid (SFNFP) for liver cancer therapy. According to SEM and TEM characterization, SFNF showed a mesoporous hollow structure. The average outer diameter was 200 nm, and the wall thickness was 50 nm. The DSC and XRD study showed that PTX in the channels of nanofibers was present in an amorphous state. The in vitro release experiments demonstrated that SFNF could efficiently improve the dissolution rate of PTX. Both in vitro cell experiments and in vivo antitumor experiments showed that SFNFP could efficiently inhibit the growth of liver cancer cells. Therefore, SFNF is a promising targeting antitumor drug delivery carrier.

HIGH POROUS NIO NANOSTRUCTURES: SYNTHESIS AND CHARACTERIZATION

&lt;p&gt;In this report,&lt;strong&gt; &lt;/strong&gt;the simple hydrothermal approaches to the fabrication of porous NiO nanostructures including nanospheres and nanotoroids were described. Morphologies and crystal structure of the as-fabricated nanomaterials were characterized by various techniques such as SEM, TEM, XRD, EDS, and N&lt;sub&gt;2&lt;/sub&gt; adsorption/desorption isotherm. The results showed that the porous NiO nanospheres have the diameter ranging from 2 to 10 µm, which are self-assembled nanoparticles (NPs). The nanotoroids have an average outer particle diameter and iner diameter are of ~300 nm and ~60 nm, respectively. This simple and mild approach to fabricate highly porous NiO nanostructures could be easily scaled up and potentially extended to the synthesis of other porous nanostructured metal oxides.&lt;/p&gt;

Novel preparation of self-assembled HCl-doped polyaniline nanotubes using compressed CO2-assisted polymerization

Recently, extraordinary attention has been given to the preparation of strong acid-doped polyaniline in distinct morphologies, such as nanofibers, nanotubes, and nanoflowers, while seeking proper and cheap energy polymeric materials. This work introduces the CO2-supported polymerization process as an advanced and novel polymerization technique to prepare rectangular cross-sectional self-assembled HCl-doped polyaniline nanotubes (HCl-PANNT) without the need to use any surfactants for the first time. Based on the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results, a rectangular cross-sectional HCl-PANNT with an average outer diameter and wall thickness of 110 and 35 nm, respectively, was prepared. Furthermore, X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were employed to reveal the crystallinity and the chemical structure of the prepared polyaniline, respectively. Accordingly, the produced PANNT has a partial crystalline structure and emeraldine salt form. Moreover, the produced HCl-PANNT showed a high electrical conductivity of 1.5 S/cm.

Synthesis and Thermoelectric Characterization of Lead Telluride Hollow Nanofibers.

Lead telluride (PbTe) nanofibers were fabricated by galvanic displacement of electrospun cobalt nanofibers where their composition and morphology were altered by adjusting the electrolyte composition and diameter of sacrificial cobalt nanofibers. By employing Co instead of Ni as the sacrificial material, residue-free PbTe nanofibers were synthesized. The Pb content of the PbTe nanofibers was slightly affected by the Pb2+ concentration in the electrolyte, while the average outer diameter increased with Pb2+ concentration. The surface morphology of PbTe nanofibers was strongly dependent on the diameter of sacrificial nanofibers where it altered from smooth to rough surface as the Pb2+ concentration increased. Some of thermoelectric properties [i.e., thermopower (S) and electrical conductivity(σ)] were systematically measured as a function of temperature. Energy barrier height (Eb) was found to be one of the key factors affecting the thermoelectric properties–that is, higher energy barrier heights increased the Seebeck coefficient, but lowered the electrical conductivity.