Investigation of critical burning of fuel droplets

Fuel droplets were simulated by porous spheres having diameters in the range 0.63 to 1.9 cm and combustion tests were conducted at pressures up to 78 atm in a quiescent cold air environment. Measurements were made of the burning rate and liquid surface temperature during steady combustion. A high pressure flat flame burner apparatus is under development in order to allow testing of high pressure droplet burning in a combustion gas environment. Work was continued on the high pressure strand combustion characteristics of liquid fuels, with the major emphasis on hydrazine. Data was obtained on the burning rate and liquid surface temperatures at pressures in the range 7 to 500 psia. The response of a burning liquid monopropellant to imposed pressure oscillations is being investigated

The investigation of critical pressure burning of fuel droplets Annual report, 1 Jan. - 31 Dec. 1970

Experimental and theoretical results of critical pressure burning of fuel droplet

High pressure combustion of liquid fuels

Measurements were made of the burning rates and liquid surface temperatures for a number of alcohol and n-paraffin fuels under natural and forced convection conditions. Porous spheres ranging in size from 0.64-1.9 cm O.D. were emloyed to simulate the fuel droplets. The natural convection cold gas tests considered the combustion in air of methanol, ethanol, propanol-1, n-pentane, n-heptane, and n-decane droplets at pressures up to 78 atmospheres. The pressure levels of the natural convection tests were high enough so that near critical combustion was observed for methanol and ethanol vaporization rates and liquid surface temperature measurements were made of droplets burning in a simulated combustion chamber environment. Ambient oxygen molar concentrations included 13%, 9.5% and pure evaporation. Fuels used in the forced convection atmospheric tests included those listed above for the natural convection tests. The ambient gas temperature ranged from 600 to 1500 K and the Reynolds number varied from 30 to 300. The high pressure forced convection tests employed ethanol and n-heptane as fuels over a pressure range of one to 40 atmospheres. The ambient gas temperature was 1145 K for the two combustion cases and 1255 K for the evaporation case

COGNITIVE COMMUNICATION COMPETENCE AS A FUNCTION OF ADAPTABILITY AND APPREHENSION IN COMMUNICATION AMONG SENIOR HIGH SCHOOL STUDENTS

This study determined to find out which domain of communicative adaptability and communication apprehension significantly predicts cognitive communication competence. A quantitative descriptive-predictive design was employed in this study. The research participants were 250 Grade 11 Senior High School students enrolled in English 1s – Oral Communication in Context at UM Digos Senior High School. The gathered data were analyzed and interpreted using the mean, standard deviation, Pearson-r, regression, and multiple linear regression. It was found that the SHS students have a high level of communicative adaptability, moderate communication apprehension, and a high level of cognitive communication competence. The study’s findings revealed a significant relationship between communicative adaptability and cognitive communication competence. In contrast, communication apprehension was adversely related to cognitive communication competence. Through multiple linear regression, the findings corroborated the three domains of communicative adaptability and communication apprehension: social confirmation, appropriate, and apprehension in small groups, significantly predict cognitive communication competence. The findings obtained in this study suggest that English language teachers may employ strategies and activities, with various contexts among various individuals, as performance tasks. It will help students adapt to various communication contexts, lessen communication apprehension, and improve communication competence.  Article visualizations

ENGLISH WRITING INSTRUCTION AND STRATEGIES AS PREDICTORS OF WRITING ANXIETY OF STUDENTS

This study aimed to determine English teachers’ writing instruction and students’ writing strategies significantly predict students’ ESL writing anxiety. The working group for the present study, in which quantitative descriptive-predictive design was employed, included 271 first-year students enrolled in GE 2 subject at UM Digos College. The participants answered adopted standard questionnaires to quantify which dimension/s of English Teachers’ writing instruction and English students’ writing strategies significantly predict/s writing anxiety. The gathered data were analyzed and interpreted using the mean and standard deviation, Pearson-r, regression, and multiple linear regression. Regression analysis was used to predict the value of writing anxiety based on the value of writing instruction and strategies. Multiple linear regression was used to model the linear relationship between writing anxiety and writing instruction and strategies. The results revealed that teachers’ explicit writing instruction in teaching and students’ employment strategies in writing helped the learners lessen their writing anxiety. The findings corroborated the three domains for English writing instructions and English writing strategies: learning to write factual texts, learning to write formal and informal texts, and resourcing, significantly predict English writing anxiety. The findings obtained in this study suggest that the employment of effective instruction and strategies for students may alleviate anxiety and desirably perform various writing tasks in any particular genre.  Article visualizations

Digital Media Player Controls Supporting Music Education

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Low NT-proBNP levels in overweight and obese patients do not rule out a diagnosis of heart failure with preserved ejection fraction

Background Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome that presents clinicians with a diagnostic challenge. The use of natriuretic peptides to exclude a diagnosis of HFpEF has been proposed. We sought to compare HFpEF patients with N-terminal pro-brain natriuretic peptide (NT-proBNP) level above and below the proposed cut-off. Methods Stable patients (n = 30) with left ventricular (LV) ejection fraction ≥ 50% were eligible if they had a diagnosis of HF according to the European Society of Cardiology diagnostic criteria. Characteristics of patients with NT-proBNP below (≤125 pg/mL) and above (\u3e125 pg/mL) the diagnostic criterion were compared. Results There were 19 (66%) women with median age 54 years. Half were African American (16, 53%), and most were obese. There were no significant differences in clinical characteristics or medication use between groups. LV end-diastolic volume index was greater in high NT-proBNP patients (P = 0.03). Left atrial volume index, E/e\u27 ratio, and E/e\u27 ratio at peak exercise were not significantly different between NT-proBNP groups. Peak oxygen consumption (VO2), VO2 at ventilatory threshold, and ventilatory efficiency measures were impaired in all patients and were not significantly different between high and low NT-proBNP patients. Conclusions NT-proBNP was below the proposed diagnostic cut-off point of 125 pg/mL in half of this obese study cohort. Cardiac diastolic dysfunction and cardiorespiratory fitness were not significantly different between high and low NT-proBNP patients. These data indicate that excluding the diagnosis of HFpEF based solely on NT-proBNP levels should be discouraged

Metabolic Modulation Predicts Heart Failure Tests Performance

The metabolic changes that accompany changes in Cardiopulmonary testing (CPET) and heart failure biomarkers (HFbio) are not well known. We undertook metabolomic and lipidomic phenotyping of a cohort of heart failure (HF) patients and utilized Multiple Regression Analysis (MRA) to identify associations to CPET and HFBio test performance (peak oxygen consumption (Peak VO2), oxygen uptake efficiency slope (OUES), exercise duration, and minute ventilation-carbon dioxide production slope (VE/VCO2 slope), as well as the established HF biomarkers of inflammation C-reactive protein (CRP), beta-galactoside-binding protein (galectin-3), and N-terminal prohormone of brain natriuretic peptide (NT-proBNP)). A cohort of 49 patients with a left ventricular ejection fraction \u3c 50%, predominantly males African American, presenting a high frequency of diabetes, hyperlipidemia, and hypertension were used in the study. MRA revealed that metabolic models for VE/VCO2 and Peak VO2 were the most fitted models, and the highest predictors’ coefficients were from Acylcarnitine C18:2, palmitic acid, citric acid, asparagine, and 3-hydroxybutiric acid. Metabolic Pathway Analysis (MetPA) used predictors to identify the most relevant metabolic pathways associated to the study, aminoacyl-tRNA and amino acid biosynthesis, amino acid metabolism, nitrogen metabolism, pantothenate and CoA biosynthesis, sphingolipid and glycerolipid metabolism, fatty acid biosynthesis, glutathione metabolism, and pentose phosphate pathway (PPP). Metabolite Set Enrichment Analysis (MSEA) found associations of our findings with pre-existing biological knowledge from studies of human plasma metabolism as brain dysfunction and enzyme deficiencies associated with lactic acidosis. Our results indicate a profile of oxidative stress, lactic acidosis, and metabolic syndrome coupled with mitochondria dysfunction in patients with HF tests poor performance. The insights resulting from this study coincides with what has previously been discussed in existing literature thereby supporting the validity of our findings while at the same time characterizing the metabolic underpinning of CPET and HFBio

Production and characterization of green and black olive paste using cream of animal and vegetable origins

Now-a-days the quest for foods with high flavonoid polyphenols content, lower fat concentration and relative high proportion of monounsaturated or polyunsaturated fatty acids is increasing. Following this tendency green and black olive pastes applying soy cream or cream of animal origin were produced equating a subsequent industrial output, and the rheological, physicochemical and sensory characteristics of were characterized. It was found that the cohesiveness, adhesiveness and hardness of the black olive paste having cream of animal origin showed minimal values. Among samples the moisture varied between 67.15 -72.16% and the inorganic residue of the black olive pastes were also significantly lower from the green olive pastes. Minimum and maximum pH values were measured in green olive paste having soy cream and black paste with cream of animal origin, respectively. The crude fat showed significant differences among the olive pastes, whereas the protein content did not vary significantly. The colour of the black paste with cream of animal origin and soy were slightly orange, whereas the green paste remained green. The sensory analysis of the black olive paste including cream of animal origin showed lower average values for consistency and appearance attributes but the opposite occurred with the salty taste and overall assessment. Concerning to the aroma, the black olive pastes showed the highest values, while the green olive pastes kept similar values. It is concluded that the higher pH of the black olive pastes in conjunction with the water contents limits the shelf life and clearly pointed the need a careful microbial control. Considering that the colour parameters of a food is the first contact point of the consumer, these descriptors in the green olive pastes also seemed to have better acceptance, whereas preferences did not followed healthy options