Optimal Processes for Controllable Oscillators

We consider the problem of optimal parametric control for a single oscillator or an ensemble of oscillators due to a change in one of the coefficients of the system of equations characterizing them. We obtain solutions for the problem of finding the maximal change in the energy of oscillations for a given time.     

Lipid degradation and sensory characteristics of M. biceps femoris in dry‐cured hams from Duroc using three different processing methods

Hams from Norwegian Duroc pigs, reared and fed identically, were dry‐cured using three different processing methods: Spanish Serrano (SS), Norwegian Parma‐style (PS) and deboning before curing (ND). The fatty acid compositions of the green and dry‐cured hams were analysed in terms of their neutral lipid, phospholipid and free fatty acid contents and correlated with sensory attributes. Although the three dry‐curing processes were quite different, the hams′ lipid profiles, lipid degradation patterns and lipid‐associated sensorial characteristics differed only slightly. The phospholipids were the most extensively degraded lipid class (88, 89% and 84% degradation in PS, SS and ND hams, respectively) for all processing methods. The SS and PS hams had slightly riper sensory profiles due to their extensive conversion of fatty acids into aroma components. The free fatty acid contents of PS, SS and ND hams were 6.3, 6.2 and 7.5 times greater than those of green hams, respectively.     

Health counseling in adolescent preventive visits: effectiveness, current practices, and quality measurement

Most morbidity and mortality among adolescents results from their participation in health-compromising behaviors. Recent guidelines for clinical adolescent preventive services recommend that primary care clinicians routinely screen for and counsel adolescents about these behaviors, identify and address related social, psychological, and biologic factors. Office-based counseling can influence adult health behaviors, but little is known about the effectiveness of office-based counseling for adolescents. In this review we: (a) evaluate available information about the effectiveness of office-based health counseling to improve outcomes; (b) report what is known about the health counseling adolescents receive from primary care clinicians; and (c) critically review different approaches that have been, or might be, used to measure the content and quality of health counseling provided during adolescent medical visits. With the emphasis on accountability in the current health care environment, evidence supporting the effectiveness of counseling is needed to justify investment in this aspect of clinical adolescent preventive services. Challenges to studying the effectiveness of health counseling include the lack of well-defined theory-based models for adolescent office-based counseling, the complexity of measuring counseling quality, and the many factors that influence adolescent outcomes. Reliable and valid measures of counseling quality are needed both to study and to ensure the quality of counseling received by adolescents. No single measure can be expected to fully capture counseling quality, although patient self-report deserves further development.     

Leydig cell tumor--comparison of results of radical and testis-sparing surgery in a single center

Twenty-two mesial roots of extracted human mandibular molars were divided into two groups based on root curvature and length. The mesiolingual canals were instrumented using either Flexofiles in a step-back anticurvature filing method, or they were instrumented with engine-driven 0.02 taper nickel-titanium files. Ground sections were prepared at 1-, 2.5-, and 5-mm levels from the working length. The mesiobuccal canal was used as an uninstrumented control for predentin character. Digitizing software was used to calculate the instrumented portion as a percentage of the total canal perimeter. The results indicated no significant difference in overall canal wall planning between the two groups and no significant difference at each of the three levels.     

In situ X-ray scattering investigations of solutions of cellulose in N-methylmorpholine-N-oxide during shear flow

There are conflicting reports that concentrated solutions of cellulose in N-methylmorpholine-N-oxide (MMNO) exhibit liquid crystal structures as is the case for many cellulose derivatives. We have prepared cellulose/MMNO solutions using two different approaches with compositions in the range 9 to 34% w/w. We have subjected these solutions to in situ X-ray scattering studies during shear flow. Such solutions do not develop any significant level of preferred orientation during shear flow. Such zero macroscopic orientation contrasts with the behaviour of related lyotropic liquid crystal polymers based on cellulose derivatives and with other liquid crystal polymer systems, for which, in all cases, a substantial level of preferred orientation develops during shear flow. We conclude that the range of cellulose/MMNO solutions studied here do not exhibit liquid crystal phases.     

A shearing-wave generator for operation in deep bore holes

An oscillation generator is developed for the German geological research project KTB (continental deep drilling). The purpose is to explore the structure of the lithosphere by shearing waves. Some technical demands are similar to the requirements of industrial servo drives: true running without cogging torques, run-up without rotor position sensor, and torque detection from the cable terminals. Supplying the machine and measuring the data through a thin and long cable impose additional problems that must be solved. The investigations show that a permanent-magnet synchronous machine is appropriate for producing shearing waves at the bottom of a deep bore hole. The restricted transmittable power makes a separate run-up motor necessary operating at a fifth of the generator frequency. The operation program, the sensorless run-up process, and the torque determination from the cable terminals are controlled by a microprocessor