In Front of Your Nose

SUMMARY

Establishing meaningful connections to faculty is a continuing challenge for academic librarians. One library's efforts at faculty outreach received unexpected assistance from the Internet, when faculty and student curiosity about this resource created opportunities for new library staff to build connections to faculty and establish their credibility on campus. In the process, the library made progress towards meeting another challenge: determining the role of the Internet in the library. Internet instruction is now integrated with library instruction and is available to faculty and students in a variety of formats.     

Critical values of stress intensity factor in mode II fracture of cementitious composites

The problem of mode II of brittle matrix composites is considered. After a short discussion of the present knowledge and a review of test results, the importance of fracture toughness in mode II is stressed. The test results presented concern both modes of fracture, and obtained values of stress intensity factorsK _Ic andK _IIc are discussed, taking into consideration the results of observations on SEM micrographs. It is suggested that the fracture toughness of concretelike materials should be expressed as a combination of mode I and II characteristics.     

SOFTWARE PROCESS FLIGHT SIMULATION Dynamic Modeling Tools and Metrics

Process flight simulation tools can help managers understand the dynamics of new processes and technologies before they are introduced. This article tells how these exploratory tools can be used for IS project management, simple modeling of the software process, and modeling the dynamics of the IS organization in transition.     

Plasma polymerization of tetrafluoroethylene. III. Capacitive audio frequency (10 kHz) and AC discharge

The plasma polymerization of tetrafluoroethylene (TFE) is studied in a capacitively coupled system with internal electrodes using a 10 kHz (af) and a 60 Hz (ac) source. The emphasis is on identifying conditions that are compatible with continuous coating of plasma polymer on a substrate moving through the center of the interelectrode gap. Operation at a pressure below 100 mTorr is most favorable for deposition of a substantial portion of the plasma polymer on this substrate. Plasma polymer deposited in this way is characterized by ESCA and by deposition rate data and compared to that deposited using rf power in both capacitively and inductively coupled systems. The polymers found in all systems are broadly similar and completely different from conventional poly(TFE). The distribution of power density in the various systems has been identified and compared. This is accomplished by using the known susceptibility of fluorine-containing polymers (including plasma polymer) to a high-power plasma as a probe of plasma power density within the interelectrode gap in the capacitively coupled system. The most active zone of the af or ac plasma is close to the electrode at a plasma pressure of approximately 40 mTorr. The use of a magnetic field leads to an intense localized glow such that etching by active fluorine atoms occurs at a specific locus on the electrode. By contrast, the low-pressure rf capacitively coupled glow discharge is the mildest of those investigated, and its most active zone is further from the electrode and much more diffusely localized by a magnetic field.     

The identification of highly chlorinated ethers and diethers in river sediment near an epichlorohydrin plant

In harbour sediment samples taken near an epichlorohydrin production plant, a series of highly chlorinated ethers and diethers were detected viz. three isomeric bis(dichloropropyl)ethers, several structurally closely related ethers with 9 carbon atoms (C₉ ethers), a number of C₁₂ ethers and diethers, and finally several C₁₅ ethers. The formation of this new class of ether compounds can be explained on the basis of the chemistry of the addition of HOCl to allylchloride. After initial addition of Cl⁻, a reactive intermediate is formed which may react with the product dichloropropanol, to give the C₆ ethers, or may polymerize with the starting compound allylchloride followed by reaction with the product, to give the C₉, C₁₂ and C₁₅ ethers.     

Ischemic preconditioning prior to myocardial protection with cold blood cardioplegia in coronary surgery

OBJECTIVE: Encouraging results on myocardial preconditioning in experimental models of infarction, stunning or prolonged ischemia raise the question whether preconditioning techniques may enhance conventional cardioplegic protection used for routine coronary surgery. METHODS: A prospective clinical trial was conducted to investigate the effect of additional ischemic normothermic preconditioning prior to cardioplegic arrest applying cold blood cardioplegia in patients scheduled for routine coronary surgery (3 vessel disease, left ventricular ejection fraction > 50%). Two cross clamp periods of 5 min with the hearts beating in sinus rhythm were applied followed by 10 min of reperfusion, each (n = 7, group I). Inducing moderate hypothermia cold blood cardioplegia was delivered antegradely. In control groups, cold intermittent blood cardioplegia (n = 7, group II) was used alone. Coronary sinus effluents were analyzed for release of creatine kinase (CK), CK-MB, lactate, and troponin T at 1, 3, 6, 9, and 12 h. In addition, postoperative catecholamine requirements were monitored. RESULTS: The procedure was tolerated well, and no perioperative myocardial infarction in any of the groups studied occurred. Concentrations of lactate tended to be higher in group I, but this difference was not significant. In addition, no significant differences for concentrations of CK, CK-MB, and troponin T were found. Following ischemic preconditioning an increased dosage of dopamine was required within the first 12 h postoperatively (group I: 2.63 +/- 1.44 microg/kg/min, group II: 0.89 +/- 1.06 microg/kg/min). CONCLUSIONS: Combining ischemic preconditioning and cardioplegic protection with cold blood cardioplegia does not appear to ameliorate myocardial protection when compared to cardioplegic protection applying cold blood cardioplegia alone. Inversely, contractile function seemed to be impaired when applying this protocol of ischemic preconditioning.     

New concepts for lithium minerals processing

A new concept for the enrichment of lithium minerals is offering higher purity and higher yield by applying new processing technologies addressing the specific properties of the pegmatitic host rock. Additional value is created from high quality by-products which will improve the sustainability of mining activity and the overall cost base. Within the new concept, flotation may even be avoided where wet separation techniques are not applicable.Two innovative processing technologies have been integrated in the new concept: electrodynamic fragmentation and optical sorting. Detailed results of lab-technical tests show that the new process design can achieve highly selective liberation and separation processes. Optical and mineralogical analyses of the test products indicate a high benefit for commercial applications.     

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