Overview of the incinerator offgas system study

The wide range of incineration designs under development or in operation for treatment of a variety of radioactive wastes has resulted in numerous offgas cleanup systems. A study has been undertaken to review current incineration and offgas systems, categorize the waste-incinerator-effluent cases, identify common offgas treatment problems and criteria, and establish class of readily available and required technology. This presentation discusses the general approach of the study and preliminary results from the incinerator and offgas systems review efforts

Diffusion and Concentration Profiles for Loading DL-propanolol in a Crosslinked Drug Carrier, Poly(N-isopropyl acrylamide) Hydrogel

As drug carriers, hydrogels feature the ability to hold a large quantity of a hydrophilic drug with highly tunable release profiles by adjusting the physicochemical properties of the polymer. Thermally sensitive polymeric hydrogels composed of poly (N-isopropylacrylamide) (PNIPAm) have attracted the attention of researchers recently due to its temperature-dependent phase transition properties. The drug in the present research was DL-propranolol hydrochloride, a synthetic beta-adrenergic receptor blocker. In this study the diffusion coefficient of drug in water was both modelled and experimentally determined The mass transfer experiment used a syringe method. UV-visible spectra of the DL-propoanolol showed a characteristic peak at 290 nm. The spectra at 8, 10 and 14 hours showed characteristic time dependent concentration profiles. An equilibrium partition coefficient was also measured at much longer times. These data will be used to parameterize a COMSOL-based model to understand the real-time loading of the drug in a massively arrayed microfluidic environment under continuous flows

Radioactive waste incineration studies at the Los Alamos Scientific Laboratory

Development and demonstration of a transuranic (TRU) waste volume-reduction process is described. A controlled-air incinerator, based upon commercially available equipment and technology, was modified for radioactive service and was successfully tested and demonstrated with contaminated waste. Demonstration of the production-scale unit was completed in May 1980 with the incineration of 272 kg of waste with an average TRU content of about 20 nCi/g. Weight and volume reduction factors for the demonstration run were 40:1 and 120:1, respectively

Recurrent Ischemic Stroke and Bleeding in Patients With Atrial Fibrillation Who Suffered an Acute Stroke While on Treatment With Nonvitamin K Antagonist Oral Anticoagulants: The RENO-EXTEND Study

Background: In patients with atrial fibrillation who suffered an ischemic stroke while on treatment with nonvitamin K antagonist oral anticoagulants, rates and determinants of recurrent ischemic events and major bleedings remain uncertain. Methods: This prospective multicenter observational study aimed to estimate the rates of ischemic and bleeding events and their determinants in the follow-up of consecutive patients with atrial fibrillation who suffered an acute cerebrovascular ischemic event while on nonvitamin K antagonist oral anticoagulant treatment. Afterwards, we compared the estimated risks of ischemic and bleeding events between the patients in whom anticoagulant therapy was changed to those who continued the original treatment. Results: After a mean follow-up time of 15.0±10.9 months, 192 out of 1240 patients (15.5%) had 207 ischemic or bleeding events corresponding to an annual rate of 13.4%. Among the events, 111 were ischemic strokes, 15 systemic embolisms, 24 intracranial bleedings, and 57 major extracranial bleedings. Predictive factors of recurrent ischemic events (strokes and systemic embolisms) included CHA2DS2-VASc score after the index event (odds ratio [OR], 1.2 [95% CI, 1.0–1.3] for each point increase; P=0.05) and hypertension (OR, 2.3 [95% CI, 1.0–5.1]; P=0.04). Predictive factors of bleeding events (intracranial and major extracranial bleedings) included age (OR, 1.1 [95% CI, 1.0–1.2] for each year increase; P=0.002), history of major bleeding (OR, 6.9 [95% CI, 3.4–14.2]; P=0.0001) and the concomitant administration of an antiplatelet agent (OR, 2.8 [95% CI, 1.4–5.5]; P=0.003). Rates of ischemic and bleeding events were no different in patients who changed or not changed the original nonvitamin K antagonist oral anticoagulants treatment (OR, 1.2 [95% CI, 0.8–1.7]). Conclusions: Patients suffering a stroke despite being on nonvitamin K antagonist oral anticoagulant therapy are at high risk of recurrent ischemic stroke and bleeding. In these patients, further research is needed to improve secondary prevention by investigating the mechanisms of recurrent ischemic stroke and bleeding

The risk of stroke recurrence in patients with atrial fibrillation and reduced ejection fraction

Abstract Background: Atrial fibrillation (AF) and congestive heart failure often coexist due to their shared risk factors leading to potential worse outcome, particularly cerebrovascular events. The aims of this study were to calculate the rates of ischemic and severe bleeding events in ischemic stroke patients having both AF and reduced ejection fraction (rEF) (⩽40%), compared to ischemic stroke patients with AF but without rEF. Methods: We performed a retrospective analysis that drew data from prospective studies. The primary outcome was the composite of either ischemic (stroke or systemic embolism), or hemorrhagic events (symptomatic intracranial bleeding and severe extracranial bleeding). Results: The cohort for this analysis comprised 3477 patients with ischemic stroke and AF, of which, 643 (18.3%) had also rEF. After a mean follow-up of 7.5 ± 9.1 months, 375 (10.8%) patients had 382 recorded outcome events, for an annual rate of 18.0%. While the number of primary outcome events in patients with rEF was 86 (13.4%), compared to 289 (10.2%) for the patients without rEF; on multivariable analysis rEF was not associated with the primary outcome (OR 1.25; 95% CI 0.84–1.88). At the end of follow-up, 321 (49.9%) patients with rEF were deceased or disabled (mRS ⩾3), compared with 1145 (40.4%) of those without rEF; on multivariable analysis, rEF was correlated with mortality or disability (OR 1.35; 95% CI 1.03–1.77). Conclusions: In patients with ischemic stroke and AF, the presence of rEF was not associated with the composite outcome of ischemic or hemorrhagic events over short-term follow-up but was associated with increased mortality or disability

Offgas treatment for radioactive waste incinerators

Incineration of radioactive materials for resource recovery or waste volume reduction is recognized as an effective waste treatment method that will increase in usage and importance throughout the nuclear industry. The offgas cleanup subsystem of an incineration process is essential to ensure radionuclide containment and protection of the environment. Several incineration processes and associated offgas cleanup systems are discussed along with potential application of commercial pollution control components to radioactive service. Problems common to radioactive waste incinerator offgas service are identified and areas of needed research and development effort are noted

Sensitivity and performance characterization of DINGU. [1,4-dinitroglycoluril (DINGU)]

DINGU, as a relatively insensitive high explosive (HE), may have interesting applications. We have been working on better methods for preparation and characterization. We have achieved a particle size suitable for formulating this compound into a PBX and have tested DINGU/binder by plate dent. We have compared the sensitivity of DINGU with that of TATB in small-scale tests. 14 refs., 2 figs., 3 tabs