Alpha Emission Spectra of 27Al, 50,52Cr, 55Mn, 54,56Fe, 58,60Ni Nucleus for Neutron Induced Reaction

The design of novel nuclear facilities, fusion as well as fission reactors, requires the knowledge of all properties of relevant materials, including the nuclear differential cross sections for a careful selection. The nuclear cross sections data for gas production via particle (neutron, proton, alpha, etc.) induced reactions are great importance in the domain in the fusion reactor technology, particularly in the calculation of nuclear transmutation rates, nuclear heating and radiation damage due to gas formation. In fusion reactor structures, a serious damage mechanism has been gas production in the metallic resulting from diverse nuclear reactions, mainly through (n, p) and (n, α), (n, d), (n, t). In the present study, by using equilibrium reaction mechanisms, the (n, xα) reaction alpha emission spectra for ²⁷Al, ^50,52Cr, ⁵⁵Mn, ^54,56Fe, ^58,60Ni isotopes were investigated from 9 to 15 MeV incident neutron energy. The equilibrium results have been calculated by using the hybrid model, the geometry dependent hybrid model. Calculation results have been also compared with the available measurements in literature.     

A Review on the Fate of Legacy and Alternative Antimicrobials and Their Metabolites during Wastewater and Sludge Treatment

Antimicrobial compounds are used in a broad range of personal care, consumer and healthcare products and are frequently encountered in modern life. The use of these compounds is being reexamined as their safety, effectiveness and necessity are increasingly being questioned by regulators and consumers alike. Wastewater often contains significant amounts of these chemicals, much of which ends up being released into the environment as existing wastewater and sludge treatment processes are simply not designed to treat many of these contaminants. Furthermore, many biotic and abiotic processes during wastewater treatment can generate significant quantities of potentially toxic and persistent antimicrobial metabolites and byproducts, many of which may be even more concerning than their parent antimicrobials. This review article explores the occurrence and fate of two of the most common legacy antimicrobials, triclosan and triclocarban, their metabolites/byproducts during wastewater and sludge treatment and their potential impacts on the environment. This article also explores the fate and transformation of emerging alternative antimicrobials and addresses some of the growing concerns regarding these compounds. This is becoming increasingly important as consumers and regulators alike shift away from legacy antimicrobials to alternative chemicals which may have similar environmental and human health concerns.     

A Facile Technique to Produce Open Cell Titanium Foams

Nature prefers open cell order in most structures such as trees and skeletons. Engineers have been imitating the nature, to obtain high specific strength, to transfer heat, energy absorbance and filtering for various applications such as filters, heat exchangers, impact absorbers, bone implants. Although ceramic foams have been produced and used as heat shields and filters, recently a great effort has been put on metallic foams produced from aluminium, copper, iron, stainless steel, nickel and titanium. Studies on open cell structured titanium foams are steps forward among these materials due its good biocompatibility and high specific strength. In this study, open cell titanium foams are produced utilizing polymer impregnation process accompanied by a facile sintering method. In traditional foam making, long sintering durations reduce the efficiency as far as cost and delivery time for producers. In order to overcome these problems, an alternative solution is made in the production of open cell titanium foams. A facile method is designed to sinter the impregnated polymers by using induction heating. Titanium foams with open cell structures are successfully produced. SEM, XRD, metallographic characterizations are performed. Average hardness value is calculated as 815.093 ± 6.59 Hv0.1.     

An experimental and theoretical examination of the effect of sulfur on the pyrolytically grown carbon nanotubes from sucrose-based solid state precursors

Multi-walled carbon nanotubes (MWCNTs) were synthesized through pyrolysis of the sulfuric acid-carbonized byproduct of sucrose. While the presence of sulfur in the reaction media has a key role in the formation and population density of MWCNTs, we have not observed the formation of Y-junctions or encountered other novel carbon nanotube formations. Results indicate the presence of sulfur in catalyst particles trapped inside nanotubes, but failed to find sulfur in the side-walls of the CNTs. In order to verify and explain these findings, we analyzed the behavior of sulfur and its possible effects on the side-wall structure of CNTs by using density functional theory-based calculations on various atomic models depicting sulfur inclusion in the side-walls. The results of the computational study were in line with the experimental results and also provided a new perspective by suggesting that the defects such as pentagons may act as nucleation sites for the Y-branches. The results indicated that sulfur prefers to adsorb on these defective regions, but it is not responsible for the formation of these structures or defects.     

Discussion on “Empirical methods for determining shaft bearing capacity of semi-deep foundations socketed in rocks”[J Rock Mech Geotech Eng 6(2017)1140-151]

A new comprehensive set of data(n = 178) is compiled by adding a data set(n = 72) collected by Arioglu et al.(2007) to the data set(n = 106) presented in Rezazadeh and Eslami(2017). Then, the compiled data set is evaluated regardless of the variation in lithology/strength. The proposed empirical equation in this study comprises a wider range of uniaxial compressive strength(UCS)(0.15 MPa σ_(rc) 156 MPa) and various rock types. Rock mass cuttability index(RMCI) is correlated with shaft resistance(r_s) to predict the shaft resistance of rock-socketed piles. The prediction capacity of the RMCI versus r_s equation is also found to be in a fair good agreement with the presented data in Rezazadeh and Eslami(2017). Since the RMCI is a promising parameter in the prediction of shaft resistance, the researchers in the rock-socketed pile design area should consider this parameter in the further investigations.     

Sorption and desorption behaviours of 2,4‐D and glyphosate in calcareous soil from Antalya,Turkey

2,4‐Dichlorophenoxyl acetic acid (2,4‐D) and glyphosate are used extensively as a herbicide in vicinity of Antalya, Turkey. Laboratory batch experiments were conducted to investigate the sorption isotherm and sorption‐desorption characteristics of 2,4‐D and glyphosate. Results indicated that degree of sorption of glyphosate was approximately 50 times higher than 2,4‐D (K_d= 34.43 vs. 0.66 L/Kg). The sorption of 2,4‐D and glyphosate was described by linear and rate‐limited processes for soil. Organic carbon content was most likely responsible for sorption behaviour of 2,4‐D and glyphosate. The rapid desorption can be attributed to soft carbon fraction (humic/fluvic acid and lipids) whereas slower desorption can be responsible by hard carbon fraction (black carbon, kerogen) of soils that led to chemically nonideal behaviour (hysteresis). Sorption of 2,4‐D was low due to most likely deactivation of organic carbon surfaces by excess carbonate fraction, whereas strong binding of glyphosate onto organic carbon causing high sorption behaviour.     

Early and delayed thallium-201 scintigraphy in thyroid nodules: the relationship between early thallium-201 uptake and perfusion

Seventy-six patients with thyroid nodules were studied. Initially, 74 MBq of thallium-201 was injected. The thyroid gland was imaged 15 min (early) and 3 h (delayed) after the injection. Thereafter, 185 MBq technetium-99m pertechnetate was injected. Immediately after the injection, a 1-min perfusion image was acquired, followed by an image at 20 min. Increased early and delayed 201Tl uptake compared with the contralateral thyroid tissue was adopted as the criterion for malignancy. Sensitivity, specificity and negative predictive values were found to be 85%, 64% and 78%, respectively, in operated patients, but these values were 86%, 87% and 95%, respectively, in the whole group, including patients followed with fine-needle aspiration biopsy. With the purpose of investigating the relationship between perfusion and early 201Tl uptake, both perfusion and early images were graded comparing nodular activity with contralateral thyroid activity. There was a poor correlation between perfusion and 201Tl uptake. The correlation was even worse in hyperactive nodules. It is concluded that early and delayed 201Tl imaging should not be used in the differential diagnosis of cold nodules and that early 201Tl uptake seems to be more closely related to factors other than perfusion.     

EGFR-Targeted Pentacyclic Triterpene Analogues for Glioma Therapy

Glioma, particularly its most malignant form, glioblastoma multiforme (GBM), is the most common and aggressive malignant central nervous system tumor. The drawbacks of the current chemotherapy for GBM have aroused curiosity in the search for targeted therapies. Aberrantly overexpressed epidermal growth factor receptor (EGFR) in GBM results in poor prognosis, low survival rates, poor responses to therapy and recurrence, and therefore EGFR-targeted therapy stands out as a promising approach for the treatment of gliomas. In this context, a series of pentacyclic triterpene analogues were subjected to in vitro and in silico assays, which were conducted to assess their potency as EGFR-targeted anti-glioma agents. In particular, compound 10 was the most potent anti-glioma agent with an IC₅₀ value of 5.82 µM towards U251 human glioblastoma cells. Taking into account its low cytotoxicity to peripheral blood mononuclear cells (PBMCs), compound 10 exerts selective antitumor action towards Jurkat human leukemic T-cells. This compound also induced apoptosis and inhibited EGFR with an IC₅₀ value of 9.43 µM compared to erlotinib (IC₅₀ = 0.06 µM). Based on in vitro and in silico data, compound 10 stands out as a potential orally bioavailable EGFR-targeted anti-glioma agent endowed with the ability to cross the blood–brain barrier (BBB).     

The effect of antioxidants on the oxidation behaviour of magnesia–carbon refractory bricks

Oxidation of carbon is the main problem in magnesia–carbon refractories. The effects of various antioxidants, Al, Si, SiC and B₄C on the oxidation resistance of magnesia–carbon bricks were investigated at temperatures of 1300 °C and 1500 °C. Carbon losses as wt.% of the bricks were calculated and oxidized areas of the bricks were examined by XRD, SEM and EDS. B₄C was found to be the most effective antioxidant at both temperatures. Magnesium–borate (Mg₃B₂O₆) compound was determined to be present by characterization studies on B₄C added specimens. Magnesium–borate, which is in liquid state above 1360 °C, had an excellent effect on the oxidation resistance of the bricks by filling up the open pores and forming a protective layer on the surface. Forsterite (Mg₂SiO₄) and spinel (MgAl₂O₄) provided similar effects on the Si and Al added specimens respectively at both temperatures. The SiC added specimens had similar phases with Si added specimens, but SiC was the least effective antioxidant at both temperatures.     

Modeling user perception of 3D video based on ambient illumination context for enhanced user centric media access and consumption

For enjoying 3D video to its full extent, it is imperative that access and consumption of it is user centric, which in turn ensures improved 3D video perception. Several important factors including video characteristics, users’ preferences, contexts prevailing in various usage environments, etc have influences on 3D video perception. Thus, to assist efficient provision of user centric media, user perception of 3D video should be modeled considering the factors affecting perception. Considering ambient illumination context to model 3D video perception is an interesting research topic, which has not been particularly investigated in literature. This context is taken into account while modeling video quality and depth perception of 3D video in this paper. For the video quality perception model: motion and structural feature characteristics of color texture sequences; and for the depth perception model: luminance contrast of color texture and depth intensity of depth map sequences of 3D video are used as primary content related factors in the paper. Results derived using the video quality and depth perception models demonstrate that these models can efficiently predict user perception of 3D video considering the ambient illumination context in user centric media access and consumption environments.