Temperature and pollution control in flames

We apply control theory for PDEs to flame control. The targeted flame is calculated with complex chemistry. For pollutant control in flames we study both the control of temperature distribution in the flame and flame length at given fuel rate in the flow. Approximate state and sensitivity evaluations as well as mesh adaptation are used to keep the complexity as low as possible and get mesh independent results. In addition, a new recursive semi-deterministic global optimization approach is tested

Y-Chromosomal Diversity in Lebanon Is Structured by Recent Historical Events

Lebanon is an eastern Mediterranean country inhabited by approximately four million people with a wide variety of ethnicities and religions, including Muslim, Christian, and Druze. In the present study, 926 Lebanese men were typed with Y-chromosomal SNP and STR markers, and unusually, male genetic variation within Lebanon was found to be more strongly structured by religious affiliation than by geography. We therefore tested the hypothesis that migrations within historical times could have contributed to this situation. Y-haplogroup J∗(xJ2) was more frequent in the putative Muslim source region (the Arabian Peninsula) than in Lebanon, and it was also more frequent in Lebanese Muslims than in Lebanese non-Muslims. Conversely, haplogroup R1b was more frequent in the putative Christian source region (western Europe) than in Lebanon and was also more frequent in Lebanese Christians than in Lebanese non-Christians. The most common R1b STR-haplotype in Lebanese Christians was otherwise highly specific for western Europe and was unlikely to have reached its current frequency in Lebanese Christians without admixture. We therefore suggest that the Islamic expansion from the Arabian Peninsula beginning in the seventh century CE introduced lineages typical of this area into those who subsequently became Lebanese Muslims, whereas the Crusader activity in the 11th–13th centuries CE introduced western European lineages into Lebanese Christians

A low-complexity global optimization algorithm for temperature and pollution control in flames with complex chemistry

Controlling flame shapes and emissions is a major objective for all combustion engineers. Considering the complexity of reacting flows, new optimization methods are required: this paper explores the application of control theory for partial differential equations to combustion. Both flame temperature and pollutant levels are optimized in a laminar Bunsen burner computed with complex chemistry using a recursive semi-deterministic global optimization algorithm. In order to keep computational time low, the optimization procedure is coupled with mesh adaptation and incomplete gradient techniques

Semideterministic global optimization method: Application to a control problem of the Burgers equation

This paper has two objectives. We introduce a new global optimization algorithm reformulating optimization problems in terms of boundary-value problems. Then, we apply this algorithm to a pointwise control problem of the viscous Burgers equation, where the control weight coefficient is progressively decreased. The results are compared with those obtained with a genetic algorithm and an LM-BFGS algorithm in order to check the efficiency of our method and the necessity of using global optimization techniques

The impact of gravity vs suction-driven therapeutic thoracentesis on pressure-related complications: the GRAVITAS multicenter randomized controlled trial

BACKGROUND: Thoracentesis can be accomplished by active aspiration or drainage with gravity. We investigated whether gravity drainage could protect against negative-pressure related complications, such as chest discomfort, re-expansion pulmonary edema or pneumothorax, compared to active aspiration. METHODS: This prospective, multicenter single blinded randomized controlled trial allocated patients with large free-flowing effusions estimated ≥ 500 mL 1:1 to active aspiration or gravity drainage. Patients rated chest discomfort on 100 mm visual analog scales before, during, and after drainage. Thoracentesis was halted at complete evacuation or for persistent chest discomfort, intractable cough, or other complication. The primary outcome was overall procedural chest discomfort scored five minutes post-procedure. Secondary outcomes included measures of discomfort and breathlessness through 48 hours post-procedure. RESULTS: One hundred forty-two patients were randomized with 140 in the final analysis. Groups did not differ for the primary outcome (mean VAS score difference 5.3 mm, 95% CI -2.4 to 13.0, p = 0.17). Secondary outcomes of discomfort and dyspnea did not differ between groups. Comparable volumes were drained in both groups but procedure duration was significantly longer in the gravity arm (mean difference 7.4 minutes, 95% CI 10.2 to 4.6, p<0.001). There were no serious complications. CONCLUSIONS: Thoracentesis via active aspiration and gravity drainage both appear safe and result in comparable levels of procedural comfort and dyspnea improvement. Active aspiration requires less total procedural time

The impact of gravity vs suction-driven therapeutic thoracentesis on pressure-related complications: the GRAVITAS multicenter randomized controlled trial

BACKGROUND: Thoracentesis can be accomplished by active aspiration or drainage with gravity. We investigated whether gravity drainage could protect against negative-pressure related complications, such as chest discomfort, re-expansion pulmonary edema or pneumothorax, compared to active aspiration. METHODS: This prospective, multicenter single blinded randomized controlled trial allocated patients with large free-flowing effusions estimated ≥ 500 mL 1:1 to active aspiration or gravity drainage. Patients rated chest discomfort on 100 mm visual analog scales before, during, and after drainage. Thoracentesis was halted at complete evacuation or for persistent chest discomfort, intractable cough, or other complication. The primary outcome was overall procedural chest discomfort scored five minutes post-procedure. Secondary outcomes included measures of discomfort and breathlessness through 48 hours post-procedure. RESULTS: One hundred forty-two patients were randomized with 140 in the final analysis. Groups did not differ for the primary outcome (mean VAS score difference 5.3 mm, 95% CI -2.4 to 13.0, p = 0.17). Secondary outcomes of discomfort and dyspnea did not differ between groups. Comparable volumes were drained in both groups but procedure duration was significantly longer in the gravity arm (mean difference 7.4 minutes, 95% CI 10.2 to 4.6, p<0.001). There were no serious complications. CONCLUSIONS: Thoracentesis via active aspiration and gravity drainage both appear safe and result in comparable levels of procedural comfort and dyspnea improvement. Active aspiration requires less total procedural time