Process technology associated with pyrochemical reprocessing

The process technology of the following three representative processes in pyrochemical reprocessing are examined in detail: melt refining, zinc distillation, and salt transport. (LK

A STUDY OF THE THERMODYNAMIC PROPERTIES OF THE VANADIUM-IRON ALLOY SYSTEM

The vapor pressure of iron over vanadium-iron alloys was measured by the torsion-effusion method in the temperature range from 1500 to 1700 deg K. The chemical activities, as weil as the free energies, entropies, and enthalpies of formation, of the alloys were computed from the vapor pressure data. The activities of iron exhibited large negative deviations from Raoult's law throughout the entire compositional range. Although the activities of vanadium, as determined by the Gibbs-Duhem relation, deviated negatively from ideal behavior in the iron-rich alloys, nearly ideal behavior was observed in the vanadium-rich alloys. Large positive excess entropies and enthalpies of formation were found at 1600 deg K. An attempt was made to interpret these quantities in terms of the various configurational, vibrational, and magnetic changes that occur in this system on alloying. (auth

Solid oxide fuel cells for transportation: A clean, efficient alternative for propulsion

Fuel cells show great promise for providing clean and efficient transportation power. Of the fuel cell propulsion systems under investigation, the solid oxide fuel cell (SOFC) is particularly attractive for heavy duty transportation applications that have a relatively long duty cycle, such as locomotives, trucks, and barges. Advantages of the SOFC include a simple, compact system configuration; inherent fuel flexibility for hydrocarbon and alternative fuels; and minimal water management. The specific advantages of the SOFC for powering a railroad locomotive are examined. Feasibility, practicality, and safety concerns regarding SOFCs in transportation applications are discussed, as am the major R D issues

Ionic conductors for solid oxide fuel cells

An electrolyte that operates at temperatures ranging from 600{degree}C to 800{degree}C is discussed. The electrolyte conducts charge ionically as well as electronically. The ionic conductors include molecular framework structures having planes or channels large enough to transport oxides or hydrated protons and having net-positive or net-negative charges. Representative molecular framework structures include substituted aluminum phosphates, orthosilicates, silicoaluminates, cordierites, apatites, sodalites, and hollandites

Development of high-performance Na/NiCl sub 2 cell

The performance of the Ni/NiCl{sub 2} positive electrode for the Na/NiCl{sub 2} battery has been significantly improved by lowering the impedance and increasing the usable capacity through the use of chemical additives and a tailored electrode morphology. The improved electrode has excellent performance even below 200{degrees}C and can be recharged within one hour. The performance of this new electrode was measured by a conventional galvanostatic method and by a newly developed powerdynamic'' method. These measurements were used to project the performance of 40 to 60-kWh batteries built with this new electrode combined with already highly developed sodium/{beta} -- alumina negative electrode. These calculated results yielded a specific power of 150--400 W/kg and a specific energy of 110--200 Wh/kg for batteries with single-tube and bipolar cell designs. This high performance, along with the high cell voltage, mid-temperature operation, fast recharge capability, and short-circuited failure mode of the electrode couple, makes the NA/NiCl{sub 2} battery attractive for electric vehicle applications

Perioperative fluid management strategies in major surgery

BACKGROUND: Both “liberal” and “goal-directed” (GD) therapy use a large amount of perioperative fluid, but they appear to have very different effects on perioperative outcomes. We sought to determine whether one fluid management strategy was superior to the others. METHODS: We selected randomized controlled trials (RCTs) on the use of GD or restrictive versus liberal fluid therapy (LVR) in major adult surgery from MEDLINE, EMBASE, PubMed (1951 to April 2011), and Cochrane controlled trials register without language restrictions. Indirect comparison between the GD and LVR strata was performed. RESULTS: A total of 3861 patients from 23 GD RCTs (median sample size = 90, interquartile range [IQR] 57 to 109) and 1160 patients from 12 LVR RCTs (median sample size = 80, IQR36 to 151) were considered. Both liberal and GD therapy used more fluid compared to their respective comparative arm, but their effects on outcomes were very different. Patients in the liberal group of the LVR stratum had a higher risk of pneumonia (risk ratio [RR] 2.2, 95% confidence interval [CI] 1.0 to 4.5), pulmonary edema (RR 3.8, 95% CI 1.1 to 13), and a longer hospital stay than those in the restrictive group (mean difference [MD] 2 days, 95% CI 0.5 to 3.4). Using GD therapy also resulted in a lower risk of pneumonia (RR 0.7, 95% CI 0.6 to 0.9) and renal complications (0.7, 95% CI 0.5 to 0.9), and a shorter length of hospital stay (MD 2 days, 95% CI 1 to 3) compared to not using GD therapy. Liberal fluid therapy was associated with an increased length of hospital stay (4 days, 95% CI 3.4 to 4.4), time to first bowel movement (2 days, 95% CI 1.3 to 2.3), and risk of pneumonia (RR ratio 3, 95% CI 1.8 to 4.8) compared to GD therapy. CONCLUSION: Perioperative outcomes favored a GD therapy rather than liberal fluid therapy without hemodynamic goals. Whether GD therapy is superior to a restrictive fluid strategy remains uncertain

Electrochemical and in situ neutron diffraction investigations of La-Ni-Al-H alloys

Li/metal hydride batteries are a strong contender to replace Ni/Cd batteries. Since the role of alloying components is not yet understood, a combination of electrochemical and neutron diffraction techniques has been designed to investigate metal hydrides. In this work, several Al-substituted LaNi{sub 5} alloys were investigated for their specific capacity (measured by mAh/La and symbolized by x in LaNi{sub 5-y}Al{sub y}H{sub x}), impedance, and cycling stability. Neutron diffraction was used to study the electrochemically induced phase transformation and structure change during charge/discharge

Dexamethasone and clinically significant postoperative nausea and vomiting: A prespecified substudy of the randomised perioperative administration of dexamethasone and infection (PADDI) trial

Background Clinically significant postoperative nausea and vomiting (PONV) is a patient-reported outcome which reflects patient experience. Although dexamethasone prevents PONV, it is unknown what impact it has on this experience. Methods In this prespecified embedded superiority substudy of the randomised Perioperative Administration of Dexamethasone and Infection (PADDI) trial, patients undergoing non-urgent noncardiac surgery received dexamethasone 8 mg or placebo intravenously after induction of anaesthesia, and completed a validated PONV questionnaire. The primary outcome was the incidence of clinically significant PONV on day 1 or day 2 postoperatively. Secondary outcomes included the incidence of clinically significant PONV and severe PONV on days 1 and 2 considered separately. Results A total of 1466 participants were included, with 733 patients allocated to the dexamethasone arm and 733 to matched placebo. The primary outcome occurred in 52 patients (7.1%) in the dexamethasone arm and 66 (9%) patients in the placebo arm (relative risk [RR]=0.79; 95% confidence interval [CI], 0.56–1.11; P=0.18). Severe PONV occurred on day 2 in 27 patients (3.9%) in the dexamethasone arm and 47 patients (6.7%) in the placebo arm (RR=0.58; 95% CI, 0.37–0.92; P=0.02; number needed-to-treat (NNT)=36.7; 95% CI, 20–202). In the entire cohort of 8880 PADDI patients, lower nausea scores, less frequent administration of antiemetics, and fewer vomiting events were recorded by patients in the dexamethasone arm up to day 2 after surgery. Conclusions Administration of dexamethasone 8 mg i.v. did not influence clinically significant PONV. Dexamethasone administration did, however, decrease the incidence and severity of PONV, and was associated with less frequent administration of antiemetic agents