In a quest of search for a new burning rate modifier for composite propellant, strontium titanate (SrTiO3), a perovskite oxide has been chosen for evaluation in a composite propellant formulation based on its other ca...In a quest of search for a new burning rate modifier for composite propellant, strontium titanate (SrTiO3), a perovskite oxide has been chosen for evaluation in a composite propellant formulation based on its other catalytic applications. Initially, SrTiO3 was characterized for particle size, morphology and material/ phase identification (using XRD). By varying SrTiO3 content in a standard composite propellant, different compositions were prepared and their performance and processing parameters like the end of mix (EOM) viscosity, mechanical properties, density, burning rate, pressure exponent (n-value), etc. were measured. The results reveal that 2% SrTiO3 causes more than 12% enhancement in propellant burning rate (at 70 ksc pressure) in comparison to the standard propellant composition. The pressure exponent also increases to 0.46, whereas the standard composition was having its value as 0.35.展开更多
Cardiovascular diseases (CVD) are the leading cause of mortality necessitating its early detection. The emergence of newer subclinical biomarkers in addition to the known cardiometabolic risk factors may play an impor...Cardiovascular diseases (CVD) are the leading cause of mortality necessitating its early detection. The emergence of newer subclinical biomarkers in addition to the known cardiometabolic risk factors may play an important role in early detection of CVD risk. In the present study, 74 adult females (30 -?75 y) with metabolic syndrome (MS) were selected and additional biochemical parameters such as C-reactive protein (CRP) and Homocysteine (Hcy) levels were analyzed. The average body mass index (BMI) and waist circumference of subjects were found to be 30 kg/m2 and99 cmrespectively. Mean LDL levels were found to be much higher than normal (139 mg/dl) while the HDL levels were low (41.5 mg/dl). The average fasting blood sugar and insulin levels were within the normal range. However, 40.5% females had serum Hcy levels >13.2 μmol/l and 59.5% women had CRP levels >3 mg/L indicating increased risk of CVD. Higher Hcy levels were associated with hyperinsulinemia (p < 0.01) and hyperglycemia (p < 0.05), indicating predilection for glucose intolerance. CRP levels showed significant negative correlation with HDL (p < 0.05), indicating a predilection for glucose intolerance. The present study reports overall more than 40% MS women are classified as high risk group using the Western standards. Limited data on normal levels of inflammatory biomarkers are available for Asian Indians. The study results indicate the importance of Hcy and CRP values among females having metabolic syndrome, known to be at a high risk of CVD.展开更多
In monolayer transition metal dichalcogenide semiconductors,valley coherence degrades rapidly due to a combination of fast scattering and inter-valley exchange interaction.This leads to a sub-picosecond valley coheren...In monolayer transition metal dichalcogenide semiconductors,valley coherence degrades rapidly due to a combination of fast scattering and inter-valley exchange interaction.This leads to a sub-picosecond valley coherence time,making coherent manipulation of exciton a highly challenging task Using monolayer MoS_(2) sandwiched between top and bottom graphene,here we demonstrate fully valley-coherent excitons by observing~100%degree of linear polarization in steady state photoluminescence.This is achieved in this unique design through a combined effect of(a)suppression in exchange interaction due to enhanced dielectric screening,(b)reduction in exciton lifetime due to a fast inter-layer transfer to graphene,and(c)operating in the motional narrowing regime.We disentangle the role of the key parameters affecting valley coherence by using a combination of calculation(solutions of Bethe-Salpeter and Maiallle-Silva-Sham equations)and a careful choice of design of experiments using four different stacks with systematic variation of screening and exciton lifetime.To the best of our knowledge,this is the first report in which the excitons are found to be valley coherent in the entire lifetime in monolayer semiconductors,allowing optical readout of valley coherence possible.展开更多
文摘In a quest of search for a new burning rate modifier for composite propellant, strontium titanate (SrTiO3), a perovskite oxide has been chosen for evaluation in a composite propellant formulation based on its other catalytic applications. Initially, SrTiO3 was characterized for particle size, morphology and material/ phase identification (using XRD). By varying SrTiO3 content in a standard composite propellant, different compositions were prepared and their performance and processing parameters like the end of mix (EOM) viscosity, mechanical properties, density, burning rate, pressure exponent (n-value), etc. were measured. The results reveal that 2% SrTiO3 causes more than 12% enhancement in propellant burning rate (at 70 ksc pressure) in comparison to the standard propellant composition. The pressure exponent also increases to 0.46, whereas the standard composition was having its value as 0.35.
文摘Cardiovascular diseases (CVD) are the leading cause of mortality necessitating its early detection. The emergence of newer subclinical biomarkers in addition to the known cardiometabolic risk factors may play an important role in early detection of CVD risk. In the present study, 74 adult females (30 -?75 y) with metabolic syndrome (MS) were selected and additional biochemical parameters such as C-reactive protein (CRP) and Homocysteine (Hcy) levels were analyzed. The average body mass index (BMI) and waist circumference of subjects were found to be 30 kg/m2 and99 cmrespectively. Mean LDL levels were found to be much higher than normal (139 mg/dl) while the HDL levels were low (41.5 mg/dl). The average fasting blood sugar and insulin levels were within the normal range. However, 40.5% females had serum Hcy levels >13.2 μmol/l and 59.5% women had CRP levels >3 mg/L indicating increased risk of CVD. Higher Hcy levels were associated with hyperinsulinemia (p < 0.01) and hyperglycemia (p < 0.05), indicating predilection for glucose intolerance. CRP levels showed significant negative correlation with HDL (p < 0.05), indicating a predilection for glucose intolerance. The present study reports overall more than 40% MS women are classified as high risk group using the Western standards. Limited data on normal levels of inflammatory biomarkers are available for Asian Indians. The study results indicate the importance of Hcy and CRP values among females having metabolic syndrome, known to be at a high risk of CVD.
文摘In monolayer transition metal dichalcogenide semiconductors,valley coherence degrades rapidly due to a combination of fast scattering and inter-valley exchange interaction.This leads to a sub-picosecond valley coherence time,making coherent manipulation of exciton a highly challenging task Using monolayer MoS_(2) sandwiched between top and bottom graphene,here we demonstrate fully valley-coherent excitons by observing~100%degree of linear polarization in steady state photoluminescence.This is achieved in this unique design through a combined effect of(a)suppression in exchange interaction due to enhanced dielectric screening,(b)reduction in exciton lifetime due to a fast inter-layer transfer to graphene,and(c)operating in the motional narrowing regime.We disentangle the role of the key parameters affecting valley coherence by using a combination of calculation(solutions of Bethe-Salpeter and Maiallle-Silva-Sham equations)and a careful choice of design of experiments using four different stacks with systematic variation of screening and exciton lifetime.To the best of our knowledge,this is the first report in which the excitons are found to be valley coherent in the entire lifetime in monolayer semiconductors,allowing optical readout of valley coherence possible.
