In this work, two-STEP SINTERING (TSS) of Al/8wt%TiC with microwave heating has been performed successfully. The composites were fabricated by uniaxial pressing of mixed Al and TiC powders and subsequent SINTERING in an argon atmosphere at different SINTERING schedules. The observational studies show a well-dispersed TiC reinforcement in the Al matrix. According to the results, relative density and strength increased from about 95. 5% and 90 MPa to 97% and 100 MPa for sintered composites at 640 °C for 2 h and 600 °C for 10 h with single STEP SINTERING by a conventional method, respectively. Also, applying the TSS method enhanced the values from 97% and 101 MPa for conventional TSS (T1=640, T2=600 °C) to 98% and 211 MPa for microwave-assisted TSS technique. It can be related to the more effective activation of the surface mechanism during fast microwave heating than the tube furnace dilatory heating. Consequently, decreasing the SINTERING temperature (T2) can proceed with densifying mechanisms.

Hydroxyapatite [HAp; Ca10(PO4)6(OH)2] biocomposites are ceramic materials that exhibit excellent bioactivity, but their inherent low mechanical behavior render them unusable for practical applications. Titania (TiO2) is added to improve inmechanical properties without diminution of biocompatibility. Two STEP SINTERING (TSS) has been applied, in the present work, to suppress the accelerated grain growth of Hydroxyapatite and Titania nanoparticles in the HA-TiO2 composites in the last SINTERING stage. Samples characterized by X-Ray diffraction and scanning electron microscopy. It was shown by application of this method, the final grain size of HA-15 wt. %TiO2 maintainslower than 100nm while by application of conventional SINTERING it reaches higher than 100nm. The optimum regime consisted of heating the green bodies up to 1150oC in the first STEP of SINTERING and then holding at 1050oC for about 25h in the second STEP. This yielded the finest microstructure with no exaggeration in grain growth and density of specimens reaches higher than 95% theoretical density.

In current work, the effect of nanosized silicon carbide as reinforcing phase and multi-STEP SINTERING on flexural strength and Vickers hardness of alumina/silicon carbide nanocomposite was investigated. The results illustrated that in spite of decrease in the densification by addition of SiC, hardness and flexural strength of composite comparing with pure matrix was increased. Also, multi-STEP SINTERING to reach the same final temperature results, the increment of the density of composites that leads to enhancement of hardness and strength of composite. Mechanical properties improvement trend had the maximum on the application of reinforcing phase. Hence addition of 5 and 10 weight percent of SiC was the optimum quantity of reinforcing phase in order to achieve the maximum of hardness and flexural strength of composite respectively.

This paper reports the successful synthesis of nano structured forsterite (Mg2SiO4) scaffold with high compressive strength for tissue engineering application. Forsterite slurry was prepared and pre-cut foams were immersed in the slurry for 5 min. The saturated foams were then annealed at various times and temperatures using the two STEP SINTERING method. The compressive strength and porosity of the scaffolds were in the range of 0.03-24.16 MPa and 58-88% depends on the heat treatment process, respectively. The J samples consisted of grains in the range of 24 to35 nm and micron size pores that could be detected by SEM observation.

Lead piezoelectric ceramics are containing a high percentage of lead. Due to the toxicity of lead and environmental problems, various attempts have been made to replace the piezoelectric ceramics. In this paper, lead-free piezoelectric powder Potassium Sodium Niobate (KNN) as a compound candidate to replace Lead piezoelectric synthesis with conventional solid-state and the parameters of the two-STEP SINTERING ceramics - such as the temperature of the first stage (T1), the second temperature (T2), and hold time at temperature T2 were studied. Also, the effect of two-STEP SINTERING on microstructure and density of compound was investigated. SEM images and density measurement results show a higher density (95.3%) and smaller grain size (3.72 mm) and lower porosity (2.45%) KNN piezoceramics have been fabricated by different two-STEP SINTERING cycles, while the KNN ceramics with excellent density (93.5%) and grain size (4.42 mm) and porosity (6.48%) were obtained by conventional SINTERING. increasing T1, and T2 result in lower necessary time in the second STEP to reach higher density with smaller final grain size. Furthermore, two-STEP SINTERING can improve microstructure and density of the KNN piezoceramics. Result showed that the two-STEP SINTERING is a promising method in SINTERING of potassium sodium niobate lead-free piezoelectric ceramics.

Two- STEP SINTERING (TSS) has been applied, in the present work, to suppress the accelerated grain growth of Hydroxyapatite Zirconia Alumina Nano composites in the last SINTERING stage. The average grain size of near full dense specimens made via conventional SINTERING (CS) was around 400nm. By using novel tow- STEP SINTERING, however, the final grain size (200nm) dropped 2 times less than that for specimens produced by the CS method. After densification, the mechanical properties, the relative proportion of TCP formed and the microstructures of the composite were observed. By used of two STEP SINTERING, highest hardness and fracture toughness, lowest relative proportion of TCP and nanostructure were achieved.

A 25 - years- old man was admitted to the hospital because of fever, chills and jaundice after return from Pakistan. On physical examination he had fever (40' c) and BP of 120170,respiratory rate and pulse rate were 24 and 100 respectively. Heart sounds were normal and there wasn't any pathologic sound in lungs. The sclera was icteric yet there wasn't any signs of anemia 'and no adenopathy was found. In abdomen, hepatosplenomegalywas present and right upper quadrant had tenderness on examination, however, there wasn't ascitis and collateral circulation. Laboratory tests performed and revealed leukopenia (3500) and thrombocytopenia (70000) but no anemia, increased liver function tests and bilirubin, though normal PT and PTT. Wright, 2 ME, widal was negative. Sonography of abdomen revealed hepatosplenomegaly, still other findings were normal. Because of high fever blood culture performed and parenteral antibiotic started. For bicytopenia and increased liver function tests, bone marrow aspiration and additional tests, also, carriedout. Markers of viral hepatitis (HAV. HBV. HCV. CMV HBV.HSV) and autoimmune hepatitis were negative and BMA was normal. After five days of admission when the patient was on parenteral ceftriaxone and did not have any fever and felt much better, the result of blood culture reported as salmonella typhi.As a result in patients with fever, jaundice and hepatosplenomegaly it is essential to consider typhoid fever, although the widal test is negative.