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Ken Mitchell

Publications and source records attributed to Ken Mitchell.

6 recordsLinked to original sources

Regions of strong coupling between soil moisture and precipitation.

Previous estimates of land-atmosphere interaction (the impact of soil moisture on precipitation) have been limited by a lack of observational data and by the model dependence of computational estimates. To counter the second limitation, a dozen climate-modeling groups have recently performed the same highly controlled numerical experiment as part of a coordinated comparison project. This allows a multimodel estimation of the regions on Earth where precipitation is affected by soil moisture anomalies during Northern Hemisphere summer. Potential benefits of this estimation may include improved seasonal rainfall forecasts.

Journal Article↗

Intraorbital ophthalmic artery aneurysms.

Angiographically documented aneurysms of the intraorbital ophthalmic artery are extremely rare. Two cases are presented of intra-orbital ophthalmic artery aneurysms, both associated with arteriovenous malformation (AVM). There have only been isolated reports documenting this combination of vascular anomalies. In the first case, the aneurysm was treated conservatively and in the second case, after staging angiography and interventional embolization, the aneurysm was removed along with the associated AVM. The clinical presentation, pathogenesis and management of this rare combination of vascular anomalies is briefly discussed.

Adult↗

More than one dilemma.

We present an unusual case that highlights a number of management dilemmas: the cause, investigation and treatment of subarachnoid hemmorrhage in patients iwth vascular connective tissue diseases; the further investigation of small aneurysms identified on CT angiography; and the difficulties associated with anticoagulation, mechanical cardiac valves and cerebral hemorrhage.

Adult↗

Comparison of vehicle exhaust emissions from modified diesel fuels.

Three diesel fuels, one oil sand-derived (OSD) diesel serving as base fuel, one cetane-enhanced base fuel, and one oxygenate [diethylene glycol dimethyl ether (DEDM)]-blended base fuel, were tested for their emission characterizations in vehicle exhaust on a light-duty diesel truck that reflects the engine technology of the 1994 North American standard. Both the cetane-enhanced and the oxygenate-blended fuels were able to reduce regulated [CO, particulate matter (PM), total hydrocarbon (THC)] and nonregulated [polyaromatic hydrocarbons (PAHs), carbonyls, and other volatile organic chemicals] emissions, except for nitrogen oxides (NO(x)), compared with the base fuel. Although burning a fuel that contains oxygen could conceivably yield more oxygenated compounds in emissions, the oxygenate-blended diesel fuel resulted in reduced emissions of formaldehyde along with hydrocarbons such as benzene, 1,3-butadiene, and PAHs. Reductions in nitro-PAH emissions have been observed in both the cetane-enhanced and oxygenated fuels. This further demonstrates the benefits of using a cetane enhancer and the oxygenated fuel component.

Air Pollutants↗