The emission spectra and burning velocity of the premixed cyanogen-fluorine flame

The premixed C₂/N₂F₂ flame has been stabilized in the 10 mm Hg pressure range, its emission spectra recorded between 2,500 and 8,000Å, and its burning velocity measured. The spectrum consists, for the most part, of the CN red and violet systems. The only other emissions characteristic of the flame were that of NCN at 3,290Åand that of a continuum whose intensity peaks at 2,900Åand which is ascribed to F atom recombination. In addition, weak NO_γ bands are present due, most likely, to an oxygen impurity in the fluorine gas. The burning velocity of the stoichiometric flame at 16.4 mm Hg was (325 ± 50) cm sec^?1.     

Electricity System Reliability Issues During Energy System Transformation

Energy system transformation in the electric energy industry encompasses a broad range of changes in how primary energy is produced, transported, converted, priced, and delivered to consumers. Minnesota Power (ALLETE) is responding to these changes by implementing strategies like our EnergyForward resource strategy. EnergyForward describes the transition to a diverse and balanced generation portfolio that meets customers' desires for clean, safe, flexible, and affordable electricity.     

Using global student rating items for summative evaluation.

Research has established the multidimensional nature of student ratings of teaching, but debate continues concerning the use of multiple- vs single-item ratings for summative evaluation. In this study, the usefulness of global items in predicting weighted-composite evaluations of teaching was evaluated with a sample of 17,183 classes from 105 institutions. In separate regression analyses containing 2 global items—one concerning the instructor, the other concerning the course—each global item accounted for more than 50% of the variance in the weighted-composite criterion measure. Student, class, and method items generally added much less variance. Results suggested that, because global items accounted for a substantial amount of the variance, a short and economical form could capture much of the information needed for summative evaluation and longer diagnostic forms could be reserved for teaching improvement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

COMPARATIVE STUDIES OF FIVE POROUS SUPPORTS FOR YEAST IMMOBILISATION BY ADSORPTION/ATTACHMENT

Five different porous carriers for brewing yeast immobilisation were compared and evaluated for suitability in a fluidised bed reactor system. Carrier morphology as revealed by scanning electron microscopy, yeast cell load per mass of carrier, minimum fluidisation velocity, and practical aspects of carrier usage were investigated. Electron microscopy revealed both surface attachment and absorption of yeast within carrier pores, depending on the carrier. Carrier pore structure was found to be important: carriers with deep subsurface cavities and narrow pore entrances gave highest levels of yeast immobilisation. The carrier of choice was the smallest diameter porous glass carrier, SIKUG41. SIKUG41 exhibited no practical physical limitations, gave second highest yeast cell loading, and the second lowest minimum fluidisation velocity.     

Computer Assessment of Atherosclerosis from Angiographic Images

A computer method for detection and quantification of atherosclerosis from angiograms has been developed and used to measure lesion change in human clinical trials. The technique involves tracking the vessel edges and measuring individual lesions as well as the overall irregularity of the arterial image. Application of the technique to conventional arterial-injection femoral and coronary angiograms is outlined and an experimental study to extend the technique to analysis of intravenous angiograms of the carotid and cornary arteries is described.     

Understanding the three national databases on collegiate alcohol and drug use

Early admission and medical treatment can improve prognosis in patients with subarachnoid hemorrhage (SAH). In our Centre in 10 years, 595 patients with SAH have been treated: 422 were admitted within 24 hours (71%) and 498 (84%) within 72 hours. 374 underwent surgical treatment: 283 within 48 hours and 91 underwent late surgery. Thirty-three patients underwent emergency surgery for intracranial hematomas, with a mortality rate of 30%. One hundred eighty-one patients in Hunt-Hess grade I-II underwent early surgery. Mortality rate was 7%. Mortality rate for rebleeding, when surgery was delayed was more than 10%. Patients in Hunt-Hess grade III underwent early surgery in the majority of cases (68 out of 111). Only in 52% of cases surgical result was good. Thirty-four out of 108 in grade IV-V underwent early surgery, with a mortality rate of 45%. The analysis of general results shows that early surgery improves prognosis in Hunt-Hess grade III patients. Also patients in Hunt-Hess grade III-IV-V can take advantage of early surgery. Old age, arterial hypertension and angiographical vasospasm do not worsen prognosis even in patients operated on early. Endovascular treatment even in acute phase has improved results especially in cases of certain aneurysms types such as posterior circulation aneurysms.     

The electronic excitation of N2 and burning velocity measurements in low-pressure,pre-mixed ammonia-fluorine flames

The electronic emission spectrum of N₂ has been obtained for the first time from a flame system. The N₂ first and second positive band systems have been observed in pre-mixed ammonia-fluorine flames burning in the 1.0 to 4.0-mm Hg pressure range. It is proposed that the N₂ excitation to the A³Σ_u⁺ and B³Π_g states arises from binary collisions between N atoms and NH radicals produced by the rapid stripping of the ammonia molecule in the reaction zone. It is further postulated that the C³Π_u state, which is 11.1 eV above the ground state, is populated by energy pooling according to

$N_2(A^3{\sum }_u^{+})+N_2(A^3{\sum }_u^{+})\to N_2(X^1{\sum }_g^{+})+N_2(C^3{\Pi }_u)$

.The measured value of the flame's burning velocity and the estimated reaction time, at 4.0 mm Hg, were (3.5 ± 0.7) × 10³ cm sec^?1 and 10 μ sec, respectively. This burning velocity is 1 to 2 orders of magnitude higher than those measured in flames supported by oxygen.     

Do college teachers who voluntarily have courses evaluated receive higher student ratings?

Analyzed Instructional Development and Effectiveness Assessment (IDEA) student rating data from 13,063 classes from several academic fields and institutions. The purpose was to test the hypothesis that teachers who voluntarily continued to use the student rating form after a first mandatory use would be rated higher by students than "nonvolunteer" teachers, who chose not to use the rating. Classes were divided into 3 groups: volunteers, in which the decision to evaluate was entirely the instructor's; intermediate, in which the evaluation was required, but the instructor chose the class; and nonvolunteers, in which the instructor was required to have the class evaluated. Statistically significant differences among the 3 groups were found for 26 of the 39 IDEA items (probably because of the very large Ns). Based upon ω–2 analyses, none of these differences were of practical significance; none of the ω–2 values accounted for even 1% of the variance. It is concluded that voluntariness of evaluation need not be taken into consideration when using large, multi-institutional, comparative student rating data pools. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)