An efficient flamelet progress-variable method for modeling non-premixed flames in weak electric fields

Combustion stabilization and enhancement of the flammability limits are mandatory objectives to improve nowadays combustion chambers. At this purpose, the use of an electric field in the flame region provides a solution which is, at the same time, easy to implement and effective to modify the flame structure. The present work describes an efficient flamelet progress-variable approach developed to model the fluid dynamics of flames immersed in an electric field. The main feature of this model is that it can use complex ionization mechanisms without increasing the computational cost of the simulation. The model is based on the assumption that the combustion process is not directly influenced by the electric field and has been tested using two chemi-ionization mechanisms of different complexity in order to examine its behavior with and without the presence of heavy anions in the mixture. Using a one- and two-dimensional numerical test cases, the present approach has been able to reproduce all the major aspects encountered when a flame is subject to an imposed electric field and the main effects of the different chemical mechanisms. Moreover, the proposed model is shown to produce a large reduction in the computational cost, being able to shorten the time needed to perform a simulation up to 40 times.Comment: 26 pages, 13 figures, paper accepted for publication on Computers and Fluid

Gaussian processes in complex media: new vistas on anomalous diffusion

Normal or Brownian diffusion is historically identified by the linear growth in time of the variance and by a Gaussian shape of the displacement distribution. Processes departing from the at least one of the above conditions defines anomalous diffusion, thus a nonlinear growth in time of the variance and/or a non-Gaussian displacement distribution. Motivated by the idea that anomalous diffusion emerges from standard diffusion when it occurs in a complex medium, we discuss a number of anomalous diffusion models for strongly heterogeneous systems. These models are based on Gaussian processes and characterized by a population of scales, population that takes into account the medium heterogeneity. In particular, we discuss diffusion processes whose probability density function solves space- and time-fractional diffusion equations through a proper population of time-scales or a proper population of length-scales. The considered modeling approaches are: the continuous time random walk, the generalized gray Brownian motion, and the time-subordinated process. The results show that the same fractional diffusion follows from different populations when different Gaussian processes are considered. The different populations have the common feature of a large spreading in the scale values, related to power-law decay in the distribution of population itself. This suggests the key role of medium properties, embodied in the population of scales, in the determination of the proper stochastic process underlying the given heterogeneous medium.This research was supported by the Basque Government through the BERC 2014–2017 and BERC 2018–2021 programs, and by the Spanish Ministry of Economy and Competitiveness MINECO through BCAM Severo Ochoa excellence accreditations SEV- 2013-0323 and SEV-2017-0718 and through project MTM2016- 76016-R MI

Early predictors of smoking cessation after myocardial infarction

The determinants of long-term smoking cessation were evaluated in 80 patients who smoked cigarettes and survived a myocardial infarction. All patients underwent a program of rehabilitation and secondary prevention including in-hospital counseling and physician-guided reinforcing sessions at 1, 3, and 6 months after discharge. At 18 months of follow-up, 53 patients (66.3%) had quit smoking. Variables associated with smoking cessation were duration of hospital stay greater than or equal to 19 days (79 vs. 48%; p less than 0.005) and peak creatine phosphokinase (CPK) elevation greater than or equal to 500 U/l (76 vs. 54%; p less than 0.05). Males tended to quit in higher proportion than females (68 vs. 44%). Age, prior myocardial infarction, other cardiovascular risk factors, infarction location, Killip class at entry, and duration of stay in coronary care unit did not significantly affect the quitting rates. Logistic regression analysis singled out the duration of hospital stay as a significant predictor of smoking cessation (p less than 0.005). Early and intensive secondary prevention during the hospital stay is crucial in promoting sustained smoking cessation after myocardial infarction

Evidence for tidal interaction and merger as the origin of galaxy morphology evolution in compact groups

We present the results of a morphological study based on NIR images of 25 galaxies, with different levels of nuclear activity, in 8 Compact Groups of Galaxies (CGs). We perform independently two different analysis: a isophotal study and a study of morphological asymmetries. The results yielded by the two analysis are highly consistent. For the first time, it is possible to show that deviations from pure ellipses are produced by inhomogeneous stellar mass distributions related to galaxy interactions and mergers. We find evidence of mass asymmetries in 74% of the galaxies in our sample. In 59% of these cases, the asymmetries come in pairs, and are consistent with tidal effects produced by the proximity of companion galaxies. The symmetric galaxies are generally small in size or mass, inactive, and have an early-type morphology. In 20% of the galaxies we find evidence for cannibalism. In 36% of the early-type galaxies the color gradient is positive (blue nucleus) or flat. Summing up these results, as much as 52% of the galaxies in our sample could show evidence of an on going or past mergers. Our observations suggest that galaxies in CGs merge more frequently under ``dry'' conditions. The high frequency of interacting and merging galaxies observed in our study is consistent with the bias of our sample towards CGs of type B, which represents the most active phase in the evolution of the groups. In these groups we also find a strong correlation between asymmetries and nuclear activity in early-type galaxies. This correlation allows us to identify tidal interactions and mergers as the cause of galaxy morphology transformation in CGs.[abridge]Comment: 64 pages, 35 figures. Accepted for publication in Ap

Awareness, treatment, and control of hypertension in the elderly in a general practice experience

In 3858 ambulatory elderly people (age greater than or equal to 65 years) prevalence of hypertension was 67.8%. The hypertensive status was unknown to both the doctor and the patient in 21.4% of cases. More than 90% of known hypertensives were treated, but hypertension could be considered as controlled in less than 30% of them

Arm position as a source of error in blood pressure measurement

The present study was designed to assess the value of correct positioning of a patient's arm when measuring blood pressure (BP). A total of 181 subjects were examined, 141 hypertensives on treatment, 25 untreated hypertensives, 15 normotensives. All the subjects underwent three BP measurements after a 5-min resting period in supine position. Then two BP readings were recorded in standing position with the arm either positioned by the patient's side or supported passively at patient's heart level. Average systolic BP (SBP) in standing position were 144.6 +/- 20.2 mmHg with the arm at the side and 136.4 +/- 21.1 mmHg with the arm at the heart level (p less than 0.001); average diastolic pressures were 99.0 +/- 12.0 mmHg and 90.2 +/- 12.3 mmHg (p less than 0.001), respectively. A fall in SBP greater than or equal to 20 mmHg from the supine to the upright position was detected in 18.2% of cases when measurement was performed at heart level; such a reduction was inapparent in two-thirds of cases when the arm was placed at the patient's body side. Incorrect positioning of a patient's arm during BP measurements in standing position leads to overestimation of BP values and masks the presence of postural hypotension

Shakhbazian compact galaxy groups. II. Photometric and spectroscopic study of ShCG 376

The results of the redshift measurements and of the detailed surface photometry in BVR of the compact group ShCG 376 are presented. The radial velocity dispersion, the virial mass, the total luminosity, the M/L ratio, and the crossing time of the group are estimated. The group consists of eight accordant redshift spiral galaxies. Four (or possibly five) of the group members have emission-line spectra. Such morphological content and the number of emission-line galaxies are very atypical for compact galaxy groups. There are signs of interaction between some members of the group. It is suggested that the irregular shape of the brightest galaxy No. 4 is probably due to interaction with other members of the group, particularly, the emission line galaxy No. 6 with a discordant redshift (Delta v = 2600 km/s). It is speculated that the latter galaxy may be a infalling intruder to the group.Comment: accepted A&A, 7 pages, 6 figures are in separate file

Anxiety and Expressed Emotion in a Sample of Obese Patients

INTRODUCTION Expressed Emotion (EE) is a measure of the intensity of the affective family climate and plays a role in disease course and outcome. Especially in urban settings, obesity is a severe problem with serious implications as far as health risks are concerned. Having a high EE caregiver has been suggested to correlate with a worse treatment compliance in obese patients. OBJECTIVES To measure level of EE, stressful events and anxiety in obese patients and their caregivers; to investigate the possible correlations between compliance with treatment and emotional temperature of families. METHODS We have already recruited more than 150 obese patients and their caregivers. Assessment included: Level of Expressed Emotion Scale (LEE), one version for patients and one for relatives in order to evaluate 4 dimensions: intrusiveness, emotional response, attitude toward disease, tolerance and expectation; the Paykel\u2019s Interview for Recent Life Events; STAI Y1 concerning state anxiety and STAI Y2 concerning trait anxiety. Furthermore we collected demographic characteristics and BMI (Body Mass Index). RESULTS Data collection and analyses are still ongoing. Preliminary results suggest a correlation between obesity and level of anxiety. We expect to find a correlation between level of EE and variation of BMI. CONCLUSIONS Levels of EE and anxiety should be considered when planning treatment interventions to enhance compliance in obese patients and to support change in their life-style

Pengendalian Frekuensi Dengan Menggunakan Kontrol Fuzzy Prediktif Pada Simulator Plant Turbin-Generator Pada PLTU

Sistem pembangkit dirasakan sangat perlu guna memenuhi kebutuhan tenaga listrik yang semakin meningkat, kestabilan sangat dibutuhkan pada proses pembangkit sehingga sistem pengendalian digunakan untuk menjaga variabel proses tersebut tetap stabil. Salah satunya adalah dengan melakukan pengendali frekuensi pada tubin-generator suatu pembangkit listik, contohnya PLTU (Pembangkit Listrik Tenaga Uap). Frekuensi dari turbin uap harus dijaga kestabilannya agar keluaran daya listrik di generator berjalan dengan baik. Fluktuasi frekuensi adalah salah satu kendala penyampaian daya listrik ke beban, juga waktu kembali yang tidak segera ke kondisi normal akan mengakibatkan kerusakan pada sistem seperti patahnya poros turbin-generator dan kemungkinan terjadi gangguan pada jaringan listrik, sehingga perlu dilakukan pengaturan laju aliran uap yang masuk ke turbin. Kontroler yang digunakan untuk menjaga Perubahan frekuensi adalah kontrol fuzzy prediktif, dengan penambahan gain K1 pada kontrol fuzzy prediktif sebesar 42.35 yang bekerja secara sucsessive kontroler ini dapat mengurangi error sebesar 1,04% jika sistem hanya menggunakan kontroler fuzzy pada saat terjadi Perubahan beban

No correlation among expressed emotion, anxiety, stress and weight loss in patients with overweight and obesity

The onset of some types of obesity may correlate with specific familial relational patterns, and expressed emotion (EE). The aim of this study is to address the current gap in the literature about EE and obesity, assessing EE in a sample of patients with overweight or obesity and their relatives. A further objective is to assess patients' weight loss, patients' and relatives' anxiety, perceived stress and their possible correlation with EE and diet compliance. A total of 220 patients with overweight or obesity and 126 relatives were recruited. Patients' baseline body mass index (BMI) was negatively correlated with educational level, but we failed to find any correlation between BMI and the other variables assessed. We found a positive correlation between EE median and stressful life events, as well as between median EE and state and trait anxiety. Our results seem to suggest that other factors than the psychological ones we investigated may play a role in treatment adherence and outcome in patients with overweight and obesity