Ceramic materials from low-melting clays modified by industrial wastes from a glass-fiber plant

The wastes from the production of glass fiber can be used not only to solve a serious ecological problem but also to increase the quality of construction ceramic articles produced at brick manufacturing plants. © 2014 Springer Science+Business Media New York

Effect of the pore space on the strength of ceramics

The results of studies of the effect of the pore space and microcracks on ceramic strength are presented. © 2012 Springer Science+Business Media New York

Исследование влияния фазового состава на термическое расширение и механические свойства сплавов Al–Сu–Li

The study employed high-temperature X-ray diffraction, quantitative phase analysis, and tensile mechanical property measurements to investigate the relationship between coefficient of thermal expansion (CTE) and phase composition, along with the average yield strengths and Young's moduli of Al–Cu–Li alloys in three different sheet orientations: 1441, V-1461, V-1469, V-1480, and V-1481. The copper content within the solid solution and the mass fractions of the T1(Al2CuLi) and δ′(Al3Li) phases were determined using an innovative technique based on measuring the lattice distance of the α solid solution, Vegard's law, and balance equations for the elemental and phase compositions of the alloys. It was observed that as the lithium-to-copper ratio in the alloys increased from 0.32 to 1.12, the proportion of the δ′(Al3Li) phase increases from 6.3–8.4 wt.% in V-1481, V-1480 and V-1469 alloys to 16.0–17.3 wt.% in 1441 and V-1461 alloys, accompanied by a decrease in the T1(Al2CuLi) phase from 5 to 1 wt.%. This led to an increase in the Young's modulus from 75 to 77 GPa due to higher overall proportion of intermetallic compounds and a reduction in yield strength from 509 to 367 MPa due to the decrease in the T1 phase. This decrease in yield strength resulted from the fact that the hardening effect of the T1 phase was 3–4 times greater than that of the δ′ phase, and this couldn't be offset by an increase in the total intermetallic compound proportion. The observed increase in Young's modulus indicated that the elastic properties of the intermetallic phases were similar, and the rise in the total fraction of intermetallic compounds compensated for the decrease in the T1 phase. Furthermore, it was demonstrated that СTE, as measured based on the thermal expansion of the solid solution, also depended on the characteristics of the intermetallic phases present in the alloy. This expanded the potential interpretations of СTE measurement results. Методами высокотемпературной рентгенографии, количественного фазового анализа и измерения механических свойств при растяжении определяли корреляционные соотношения характеристик термического расширения (ТКЛР) и фазового состава с усредненными значениями по 3-м направлениям в листах пределов текучести и модулей Юнга сплавов системы Al–Cu–Li: 1441, В-1461, В-1469, В-1480 и В-1481. Содержание меди в твердом растворе и массовые доли фаз T1(Al2CuLi) и δ′(Al3Li) оценивали с помощью оригинальной методики, основанной на измерении периода решетки α-твердого раствора, законе Вегарда и уравнениях баланса элементного и фазового составов сплавов. Показано, что с увеличением отношения лития к меди в сплавах от 0,32 до 1,12 повышается доля δ′(Al3Li)-фазы от 6,3–8,4 мас.% в сплавах В-1481, В-1480 и В-1469 до 16,0–17,3 мас.% в сплавах 1441 и В-1461 за счет снижения количества T1(Al2CuLi)-фазы от 5 до 1 мас.%. Это приводит к увеличению модуля Юнга от 75 до 77 ГПа из-за возрастания суммарной доли интерметаллидов и к снижению предела текучести от 509 до 367 МПа из-за уменьшения количества Т1-фазы, поскольку эффект упрочнения T1-фазы в 3–4 раза превосходит упрочнение от выделения δ′-фазы, что не может быть скомпенсировано повышением суммарной доли интерметаллидов. Тот факт, что модуль Юнга при этом увеличивается, свидетельствует о том, что упругие свойства интерметаллидных фаз близки и возрастание суммарной доли интерметаллидов компенсирует снижение количества T1-фазы. Показано, что величина ТКЛР, измеренная на основании термического расширения твердого раствора, зависит также от характеристик присутствующих в сплаве интерметаллидных фаз, что расширяет возможности интерпретации результатов измерения ТКЛР.

Novel Anti-bacterial Activities of β-defensin 1 in Human Platelets: Suppression of Pathogen Growth and Signaling of Neutrophil Extracellular Trap Formation

Human β-defensins (hBD) are antimicrobial peptides that curb microbial activity. Although hBD's are primarily expressed by epithelial cells, we show that human platelets express hBD-1 that has both predicted and novel antibacterial activities. We observed that activated platelets surround Staphylococcus aureus (S. aureus), forcing the pathogens into clusters that have a reduced growth rate compared to S. aureus alone. Given the microbicidal activity of β-defensins, we determined whether hBD family members were present in platelets and found mRNA and protein for hBD-1. We also established that hBD-1 protein resided in extragranular cytoplasmic compartments of platelets. Consistent with this localization pattern, agonists that elicit granular secretion by platelets did not readily induce hBD-1 release. Nevertheless, platelets released hBD-1 when they were stimulated by α-toxin, a S. aureus product that permeabilizes target cells. Platelet-derived hBD-1 significantly impaired the growth of clinical strains of S. aureus. hBD-1 also induced robust neutrophil extracellular trap (NET) formation by target polymorphonuclear leukocytes (PMNs), which is a novel antimicrobial function of β-defensins that was not previously identified. Taken together, these data demonstrate that hBD-1 is a previously-unrecognized component of platelets that displays classic antimicrobial activity and, in addition, signals PMNs to extrude DNA lattices that capture and kill bacteria

Ceramic materials from low-melting clays modified by industrial wastes from a glass-fiber plant

The wastes from the production of glass fiber can be used not only to solve a serious ecological problem but also to increase the quality of construction ceramic articles produced at brick manufacturing plants. © 2014 Springer Science+Business Media New York

STUDY OF COMPOSITION FILM SYSTEM PB-SE AND CHANGE OF STRUCTURE UNDER TEMPERATURE ACTION

The Pb-Se film systems were obtained by solid-phase synthesis and investigated by Xray diffraction and X-ray photoelectron spectroscopy, electron Auger spectroscopy. It was found that the films are heterogeneous in structure and composition. To study the structural features under the influence of temperature, Raman spectra of samples at temperatures of 300 K and 373 K were investigated

Ceramic materials from low-melting clays modified by industrial wastes from a glass-fiber plant

The wastes from the production of glass fiber can be used not only to solve a serious ecological problem but also to increase the quality of construction ceramic articles produced at brick manufacturing plants. © 2014 Springer Science+Business Media New York