Tungsten bronze structure ceramics have found vital potential in many applications such as actuators, transducer, electro-optic, ferroelectric random access memory and microwave devices. These type ceramics are extens...Tungsten bronze structure ceramics have found vital potential in many applications such as actuators, transducer, electro-optic, ferroelectric random access memory and microwave devices. These type ceramics are extensively used in many industrial applications due to their spontaneous polarization and well-known for its high dielectric constant, low dielectric loss, low leakage current density, good thermal stability and high piezoelectric coefficient. In present work, Ba5CaTi2Nb8O30 (BCTN) has been synthesized first time through solid state reaction method. The microstructures, dielectric, ferroelectric, ferromagnetic and Raman spectra have been investigated by means of X-ray diffraction, Scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), LCR meter, P-E loop tracer, VSM and Raman spectrometer respectively. X-ray dif-fraction study revealed the formation of single phase tetragonal structure with space group P4bm. The crystallite size was observed to be in the range 14.4 nm. Detailed dielectric properties of BCTN compound as function of temperature at different frequencies show that sample exhibits diffuse type transition at curie temperature 316°C. The P-E and M-H studies confirmed the coexistent ferroelectricity and magnetism at room temperature.展开更多
Polycrystalline cobalt-substituted tungsten bronze ferroelectric ceramics with chemical composition Ba_(5)CaTi_(2-x)Co_(X)Nb_(8)O_(30)(x=0.00,0.02,0.04 and 0.08)were synthesized by solid state reaction technique.X-ray...Polycrystalline cobalt-substituted tungsten bronze ferroelectric ceramics with chemical composition Ba_(5)CaTi_(2-x)Co_(X)Nb_(8)O_(30)(x=0.00,0.02,0.04 and 0.08)were synthesized by solid state reaction technique.X-ray diffraction(XRD)technique was used to confirm the phase formation and it revealed the formation of single phase tetragonal structure with space group P4bm.The surface morphology of the samples was studied by using the scanning electron microscopy(SEM)technique.The dielectric properties such as dielectric constant and dielectric loss have been investigated as a function of temperature and frequency.The P-E and M-H studies confirmed the coexistent of ferroelectricity and magnetism at room temperature.The P-E loop study indicated an increase in the coercive field while the M-H study depicted a decrease in the magnetization with the incorporation of cobalt ions.展开更多
Pulmonary alveolar proteinosis(PAP)is an idiopathic rare diffuse pulmonary disease,first described in 1958 by Rosen et al.Its estimated prevalence is about 1 in 3.7-6.9×10^(6) with a male:female ratio of 1:1-2:1....Pulmonary alveolar proteinosis(PAP)is an idiopathic rare diffuse pulmonary disease,first described in 1958 by Rosen et al.Its estimated prevalence is about 1 in 3.7-6.9×10^(6) with a male:female ratio of 1:1-2:1.Majority of the patient’s age ranges between 20 and 50 years.PAP on microscopy is characterized by the presence of massive insoluble,amorphous,phospholipid-rich protein deposits in the bronchial and alveolar cavities.Most patients with acquired PAP present with cough and exertional dyspnea.It has been studied that there is increased risk of superinfection in PAP with opportunistic organisms like pneumocystis and vice versa.Definitive diagnosis of Pneumocystis jirovecii pneumonia rests on the demonstration of the organism within the alveoli by special stains like Grocott Methenamine Silver stain.Molluscum contagiosum(MC)is a common superficial skin infection caused by the poxvirus.MC is characterized by painless papules commonly seen in children and immunocompromised individuals.Here,we present a 34-year-old female who had complaints of severe difficulty in breathing and was brought dead to our hospital.On external examination,she had multiple warts over chest,abdomen,and over genitalia.Internal examination was unremarkable.Specimens of kidney,lung,and skin biopsy of genital warts sent for histopathological examination revealed acute tubular necrosis,P.jirovecii with PAP,and MC respectively.展开更多
文摘Tungsten bronze structure ceramics have found vital potential in many applications such as actuators, transducer, electro-optic, ferroelectric random access memory and microwave devices. These type ceramics are extensively used in many industrial applications due to their spontaneous polarization and well-known for its high dielectric constant, low dielectric loss, low leakage current density, good thermal stability and high piezoelectric coefficient. In present work, Ba5CaTi2Nb8O30 (BCTN) has been synthesized first time through solid state reaction method. The microstructures, dielectric, ferroelectric, ferromagnetic and Raman spectra have been investigated by means of X-ray diffraction, Scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), LCR meter, P-E loop tracer, VSM and Raman spectrometer respectively. X-ray dif-fraction study revealed the formation of single phase tetragonal structure with space group P4bm. The crystallite size was observed to be in the range 14.4 nm. Detailed dielectric properties of BCTN compound as function of temperature at different frequencies show that sample exhibits diffuse type transition at curie temperature 316°C. The P-E and M-H studies confirmed the coexistent ferroelectricity and magnetism at room temperature.
基金the Deanship of Scientific Research at King Saud University for its funding through the Research Group Project No.RG-1437-030.
文摘Polycrystalline cobalt-substituted tungsten bronze ferroelectric ceramics with chemical composition Ba_(5)CaTi_(2-x)Co_(X)Nb_(8)O_(30)(x=0.00,0.02,0.04 and 0.08)were synthesized by solid state reaction technique.X-ray diffraction(XRD)technique was used to confirm the phase formation and it revealed the formation of single phase tetragonal structure with space group P4bm.The surface morphology of the samples was studied by using the scanning electron microscopy(SEM)technique.The dielectric properties such as dielectric constant and dielectric loss have been investigated as a function of temperature and frequency.The P-E and M-H studies confirmed the coexistent of ferroelectricity and magnetism at room temperature.The P-E loop study indicated an increase in the coercive field while the M-H study depicted a decrease in the magnetization with the incorporation of cobalt ions.
文摘Pulmonary alveolar proteinosis(PAP)is an idiopathic rare diffuse pulmonary disease,first described in 1958 by Rosen et al.Its estimated prevalence is about 1 in 3.7-6.9×10^(6) with a male:female ratio of 1:1-2:1.Majority of the patient’s age ranges between 20 and 50 years.PAP on microscopy is characterized by the presence of massive insoluble,amorphous,phospholipid-rich protein deposits in the bronchial and alveolar cavities.Most patients with acquired PAP present with cough and exertional dyspnea.It has been studied that there is increased risk of superinfection in PAP with opportunistic organisms like pneumocystis and vice versa.Definitive diagnosis of Pneumocystis jirovecii pneumonia rests on the demonstration of the organism within the alveoli by special stains like Grocott Methenamine Silver stain.Molluscum contagiosum(MC)is a common superficial skin infection caused by the poxvirus.MC is characterized by painless papules commonly seen in children and immunocompromised individuals.Here,we present a 34-year-old female who had complaints of severe difficulty in breathing and was brought dead to our hospital.On external examination,she had multiple warts over chest,abdomen,and over genitalia.Internal examination was unremarkable.Specimens of kidney,lung,and skin biopsy of genital warts sent for histopathological examination revealed acute tubular necrosis,P.jirovecii with PAP,and MC respectively.
