Carbonate Hydroxyapatite and Silicon-Substituted Carbonate Hydroxyapatite: Synthesis, Mechanical Properties, and Solubility Evaluations

The present study investigates the chemical composition, solubility, and physical and mechanical properties of carbonate hydroxyapatite (CO3Ap) and silicon-substituted carbonate hydroxyapatite (Si-CO3Ap) which have been prepared by a simple precipitation method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF) spectroscopy, and inductively coupled plasma (ICP) techniques were used to characterize the formation of CO3Ap and Si-CO3Ap. The results revealed that the silicate (SiO4 4−) and carbonate (CO3 2−) ions competed to occupy the phosphate (PO4 3−) site and also entered simultaneously into the hydroxyapatite structure.TheSi-substitutedCO3Ap reduced the powder crystallinity and promoted ion release which resulted in a better solubility compared to that of Si-free CO3Ap. The mean particle size of Si-CO3Ap was much finer than that of CO3Ap. At 750∘C heat-treatment temperature, the diametral tensile strengths (DTS) of Si-CO3Ap and CO3Ap were about 10.8 ± 0.3 and 11.8 ± 0.4 MPa, respectively

Theoretical and experimental study of the orientational ordering in the field-induced intermediaite phase from the SmC*FI2 phase in chiral smectic liquid crystals

Under an electric field, chiral smectic liquid crystals transit usually to the unwound SmC* phase where the helical structure is completely unrolled. Sometimes the sample transits initially towards an intermediate polar state before the total destruction of the helix. Based on the extension of the H-T model, a theoretical study of these field-induced phase transitions was carried out. Two hypotheses of the dynamics that give rise to the appearance of the intermediate phase have been discussed. The results of a numerical analysis confirm the known experimental results; the intermediate phase has a three-layer periodicity structure

Modeling of Indoor Wave Propagation Models from 1 G Hz to 10 G Hz

This paper presents the modeling of indoor wave propagation from 1 GHz to 10 GHz. Several obstacles such as partition, whiteboard, and door have been tested and measured their losses compare to line of sight. Horn antennas have been used as transmitter and receiver. An average attenuation between of this obstacle between 1.5 dB to 3.0 dB has been observed. Prediction model for this indoor propagation has been presented using suitable software. Finally, results, discussion, conclusions and further work are given

High Gain Cascaded Low Noise Amplifier Using T Matching Network

This project presents a design of high gain cascaded low noise amplifier (LNA), which operates at 5.8 GHz frequency for WiMAX application. The LNA designed used T matching network consist of lump reactive elements and microstrip at the input and output impedance. A cascaded LNA is developed in this project contributes a high gain of 36.8 dB with overall noise figure of 1.3 dB. The overall measured bandwidth measures is 1.240 GHz with S parameters S11, S12 and S22 measured are -11.4dB, -39.1dB and -12.3dB respectively. The input sensitivity of the LNA is -80dBm which compliant with the IEEE 802.16 WiMAX application. The LNA used FET transistor FX 76 LP from Eudina In

5.8 GHz Radio Frequency Amplifier with 3 dB Π Network Attenuator

This paper presents a design of radio frequency amplifier (RFA), which operates at 5.8 GHz frequency for WiMAX application. The RFA designed used T matching network consist of lump reactive elements, 3 dB attenuator and microstrip line at the input and output impedance. The RFA developed in this project contributes a gain of 15.6 dB with overall noise figure of 2.4 dB. The overall measured bandwidth measures is 1.240 GHz with S parameters S11, S12 and S22 measured are -12.4 dB, -25.5 dB and -12.3 dB respectively. The RFA used FET transistor EPA018A from Excelics Semiconductor Inc

Circle grid fractal plate as a turbulent generator for premixed flame: an overview

This review paper focuses to ascertain a new approach in turbulence generation on the structure of premixed flames and external combustion using a fractal grid pattern. This review paper discusses the relationship between fractal pattern and turbulence flow. Many researchers have explored the fractal pattern as a new concept of turbulence generators, but researchers rarely study fractal turbulence generators on the structure premixed flame. The turbulent flow field characteristics have been studied tand investigated in a premixed combustion application. In terms of turbulence intensity, most researchers used fractal grid that can be tailored so that they can design the characteristic needed in premixed flame. This approach makes it extremely difficult to determine the exact turbulent burning velocity on the velocity fluctuation of the flow. The decision to carry out additional research on the effect circle grid fractal plate as a turbulent generator for premixed flame should depends on the blockage ratio and fractal pattern of the grid. 1

High Gain Cascaded Low Noise Amplifier using T-Matching Network

This project presents a design of high gain cascaded low noise amplifier (LNA), which operates at 5.8 GHz frequency for WiMAX application. The LNA designed used T-matching network consisting of lump reactive elements and microstrip at the input and the output matching load uses quarter wavelength techniques. A cascaded LNA is developed in this project contribute a high gain of 36.8 dB with overall noise figure of 1.3 dB. The overall measured bandwidth measures is 1.240 GHz with S parameters S11, S12 and S22 measured are -11.4dB, -39.1dB and -12.3dB respectively. The input sensitivity of the LNA is -80dBm which compliant with the IEEE 802.16 WiMAX application. The LNA used FET transistor FHX 76 LP from Eudina Inc

The DmsABC Sulfoxide Reductase Supports Virulence in Non-typeable Haemophilus influenzae.

Although molybdenum-containing enzymes are well-established as having a key role in bacterial respiration, it is increasingly recognized that some may also support bacterial virulence. Here, we show that DmsABC, a putative dimethylsulfoxide (DMSO) reductase, is required for fitness of the respiratory pathogen Haemophilus influenzae (Hi) in different models of infection. Expression of the dmsABC operon increased with decreasing oxygen availability, but despite this, a Hi2019Δd msA strain did not show any defects in anaerobic growth on chemically defined medium (CDM), and viability was also unaffected. Although Hi2019Δd msA exhibited increased biofilm formation in vitro and greater resistance to hypochlorite killing compared to the isogenic wild-type strain, its survival in contact with primary human neutrophils, in infections of cultured tissue cells, or in a mouse model of lung infection was reduced compared to Hi2019WT. The tissue cell infection model revealed a two-fold decrease in intracellular survival, while in the mouse model of lung infection Hi2019Δd msA was strongly attenuated and below detection levels at 48 h post-inoculation. While Hi2019WT was recovered in approximately equal numbers from bronchoalveolar lavage fluid (BALF) and lung tissue, survival of Hi2019Δd msA was reduced in lung tissue compared to BALF samples, indicating that Hi2019Δd msA had reduced access to or survival in the intracellular niche. Our data clearly indicate for the first time a role for DmsABC in H. influenzae infection and that the conditions under which DmsABC is required in this bacterium are closely linked to interactions with the host

Preparation of Microcrystals of Piroxicam Monohydrate by Antisolvent Precipitation via Microfabricated Metallic Membranes with Ordered Pore Arrays

Microcrystals of piroxicam (PRX) monohydrate with a narrow size distribution were prepared from acetone/PRX solutions by antisolvent crystallization via metallic membranes with ordered pore arrays. Crystallization was achieved by controlled addition of the feed solution through the membrane pores into a well-stirred antisolvent. A complete transformation of an anhydrous form I into a monohydrate form of PRX was confirmed by Raman spectroscopy and differential scanning calorimetry. The size of the crystals was 7–34 μm and was controlled by the PRX concentration in the feed solution (15–25 g L¯¹), antisolvent/solvent volume ratio (5–30), and type of antisolvent (Milli-Q water or 0.1–0.5 wt % aqueous solutions of hydroxypropyl methyl cellulose (HPMC), poly(vinyl alcohol) or Pluronic P-123). The smallest crystals were obtained by injecting 25 g L¯¹ PRX solution through a stainless-steel membrane with a pore size of 10 μm into a 0.06 wt % HPMC solution stirred at 1500 rpm using an antisolvent/solvent ratio of 20. HPMC provided better steric stabilization of microcrystals against agglomeration than poly(vinyl alcohol) and Pluronic P-123, due to hydrogen bonding interactions with PRX and water. A continuous production of large PRX monohydrate microcrystals with a volume-weighted mean diameter above 75 μm was achieved in a continuous stirred membrane crystallizer. Rapid pouring of Milli-Q water into the feed solution resulted in a mixture of highly polydispersed prism-shaped and needle-shaped crystals