Displaced Capital

This paper studies the efficiency with which physical capital can be reallocated across sectors. It presents a model of a firm selling specialized capital in a thin resale market. The model predicts that the selling price depends not only on the sectoral specificity of capital, but also on the thinness of the market and the discount factor of the firm. It then provides empirical evidence on the sectoral mobility of capital based on equipment-level data from aerospace industry auctions. These data track the flow of used capital across industries, as well as the discounts at which the capital sells. The results suggest substantial sectoral specificity of capital. Capital that flowed out of the sector sold for only one-third of its estimated replacement cost.

Why Do Computers Depreciate?

The value of installed computers falls rapidly and therefore computers have a very high user cost. The paper provides a complete account of the non-financial user cost of personal computers -- decomposing it into replacement cost change, obsolescence, instantaneous depreciation, and age-related depreciation. The paper uses data on the resale price of computers and a hedonic price index for new computers to achieve this decomposition. Once obsolescence is taken into account, age-related depreciation -- which is often identified as deterioration -- is estimated to be negligible. While the majority of the loss in value of used computers comes from declines in replacement cost, this paper shows the second most important source of decline in value is obsolescence. Obsolescence is accelerated by the decline in replacement cost of computers. Cheaper computing power drives developments in software and networks that make older computers less productive even though their original functionality remains intact.

Elastic Weights for Trusses by the String Polygon Methrod

Civil Engineerin

Gadolinium-153 production at the Oak Ridge National Laboratory

Gadolinium-153 production at the Oak Ridge National Laboratory (ORNL) involves the neutron irradiation of natural europium oxide (47.8% /sup 151/Eu, 52.2% /sup 153/Eu). This target material undergoes a series of neutron captures and radioactive decays to produce the desired /sup 153/Gd product. Several undesirable europium isotopes (/sup 152/Eu, /sup 154/Eu, and /sup 156/Eu) are also produced during this irradiation process. Recent technical advances and other improvements in the radiochemical processing of this isotope have allowed ORNL to increase production by more than sevenfold. A newly developed electrochemical process has allowed the separation of the bulk of undesirable europium isotopes and has also effected a more efficient use of high-pressure ion exchange to achieve a final product radiochemical purity >99.999%. Specific activities >60 Ci/g of gadolinium oxide and product specific yields >2.9 Ci/g of irradiated europium oxide have been produced. Use of unique glove box manipulators and special equipment designed at ORNL have allowed final source fabrication to keep pace with the increased production rate while minimizing the radiation exposure to operating personnel. 5 refs., 4 figs., 4 tabs

What Trump and Clinton’s personality traits tell us about how they might govern as president.

During the course of the 2016 presidential election, the topic of candidate temperament and fitness for office has been widely discussed. Adam J. Ramey, Jonathan D. Klingler, and Gary E. Hollibaugh, Jr. show how their personality traits can be estimated from their speech, and what these estimates imply for how they might govern from the White House: Clinton is likely to push substantive policies and back them up, while Trump would push for bolder and more costly proposals, without as much follow-through

Totally endoscopic robot-assisted transmyocardial revascularization

ObjectiveLaser transmyocardial revascularization is an emerging therapy for intractable angina stemming from diffuse, small-vessel coronary disease not amenable to percutaneous coronary intervention or coronary bypass grafting. Presently, this therapy is delivered through a median sternotomy or left thoracotomy. In this pilot study, we sought to combine the advantages of a dexterous robotic surgical platform with a flexible fiberoptic laser to develop a minimally invasive approach toward transmyocardial revascularization.MethodsA flexible fiberoptic holmium:yttrium-aluminum-garnet laser probe (CardioGenesis Corporation, Foothill Ranch, Calif), deployed with the da Vinci surgical robotic system (Intuitive Surgical, Sunnyvale, Calif), was used to create transmyocardial channels through all left ventricular wall regions in 5 canine subjects. The channels were localized, quantified, and histologically analyzed to assess distribution, dimensions, and transmurality.ResultsTransmyocardial channels were successfully created in all 6 defined left ventricular wall segments by using this minimally invasive approach without port repositioning, instrument exchange, or probe modifications. Gross pathologic and histologic analyses confirmed the uniform distribution of 1.0-mm transmural channels in all left ventricular regions. No direct pressure, topical hemostatic agents, or suture repairs were required for hemostasis. No significant hemodynamic instability or sustained arrhythmias were encountered at any time during the procedures.ConclusionsWe report the first use of a prototype flexible fiberoptic laser probe deployed by the da Vinci surgical robotic system to successfully perform totally endoscopic off-pump transmyocardial revascularization in a canine model, demonstrating the feasibility, precision, and safety of this approach. Refinement of this minimally invasive technique may reduce the morbidity of open-chest transmyocardial revascularization and facilitate its use as sole therapy or as an adjunct to percutaneous coronary interventions