The Mecoptera of Michigan

(excerpt) To date, no one has published on the Mecoptera of Michigan. A comprehensive taxonomic paper on the Mecoptera of Illinois, by Donald W. Webb, Illinois Natural History Survey, and Norman D. Penny, University of Kansas, is in preparation and will include keys to and descriptions of the midwestern species of Mecoptera. It is hoped that the present paper will supplement the publication by Webb and Penny and enable interested persons in Michigan to easily identify adult Mecoptera

Modelling and Control of an Annular Momentum Control Device

The results of a modelling and control study for an advanced momentum storage device supported on magnetic bearings are documented. The control challenge posed by this device lies in its dynamics being such a strong function of flywheel rotational speed. At high rotational speed, this can lead to open loop instabilities, resulting in requirements for minimum and maximum control bandwidths and gains for the stabilizing controllers. Using recently developed analysis tools for systems described by complex coefficient differential equations, the closed properties of the controllers were analyzed and stability properties established. Various feedback controllers are investigated and discussed. Both translational and angular dynamics compensators are developed, and measures of system stability and robustness to plant and operational speed variations are presented

Stability of optically-active charged excitons in quasi-two dimensional systems

A negatively charged quasi-two dimensional exciton ($X^-$) is solved exactly numerically in the presence of a uniform perpendicular B-field. Various quasi-two dimensional geometries are studied. The charge distribution of the $X^-$ parallel to the B-field is found to be crucial in determining the stability of the optically-active $X^-$ and hence its photoluminescence (PL) signature. The theory provides a quantitative explanation of recent experimental results obtained for a GaAs quantum well. Effects are found which cannot be described within a lowest Landau level approximation. PACS: 78.20.Ls 78.66.-w 73.20.DxComment: Minor revisions, mainly removal of the term trion in favour of the term charged-exciton to comply with Physical Review B. To be published as a Rapid Communication in Physical Review

Numbers, Condition and Economics in Range Management

Recently I participated in Montana\u27s Ag Lender\u27s Range School in Miles City. It was, in my judgment, a good session. We had the opportunity to view range research that demonstrated long-term differences in livestock performance where variable stocking rates and utilization had been practiced. In total, the best systems were those that were conservative and consistent with Soil Conservation Service and Montana State University guidelines

An Evaluation of Implementation and Effectiveness of Professional Learning Communities in Minnesota Public Schools

Abstract In 1985, professional learning community (PLC) pioneers, Shirley Hord, Richard DuFour and Robert Eaker undertook an exploration of the concept of teachers working in small groups or learning communities. Participants in these initial learning communities shared common experiences, ideas, practices, and developed strategies to address issues they faced in their work with students (Hord 1997; DuFour & Eaker 1998). This concept was supported by McLaughlin and Talbert (1993) when they suggested that, given the opportunity for collaborative inquiry, veteran teachers will share the wisdom they have gained through experience in a way that allows improved teaching practices for all involved. In 2000, Senge, Cambron-McCabe, Lucas, Smith, Dutton and Kleiner, reported that the, “learning organization approach to education” needs to be more than just talking and working in groups. It needs to involve everyone “…in expressing their aspirations, building their awareness and developing their capabilities together” (Senge et al., 2000, p. 5). Over time this learning community concept became known as the professional learning community, or PLC (Hord, 1997). DuFour & Eaker (1998), Lieberman and Pointer-Mace (2009), Darling-Hammond (1996) and Bryk and Schneider (2003), all contended that these professional learning communities have the capacity to transcend reform movements and result in continuous improvement in schools. Over time, many school districts and their leaders have modified the professional learning community concept. They have done so to such a degree that they may no longer achieve, fully, their originally desired or anticipated results. In July 2011, the Minnesota legislature passed House File No. 26 (HF 26), a revision of the statewide teacher evaluation system. This legislation brought about numerous changes to Minnesota Statute 122A.40, subd. 8. One of these changes was the promotion of PLCs in public schools. Even though much has been written about PLCs and their intended uses, limited research was found regarding whether or not PLCs are being implemented consistent with best practice, as identified in research, in the public schools of Minnesota. This study will examine the level to which the key characteristics of PLCs, as identified by DuFour, DuFour, Eaker and Many (2010) are being implemented in Minnesota public schools. It also identifies the barriers encountered by public school districts in implementing PLCs. The conceptual framework for this study was derived from the work of DuFour et al. (2010), in their book, Learning by Doing: A Handbook for Professional Learning Communities at Work (2nd Ed). The purpose of the study is to examine professional learning communities in public schools in Minnesota using the characteristics identified by DuFour et al. (2010). While PLCs are now recommended in all public schools by Minnesota State Statute, there are no studies which examine whether or not these PLCs are being implemented effectively based on best practices described in research. This study attempts to determine if PLCs are in fact being implemented effectively, based on best practices described in research, by: describing and contrasting the characteristics of PLCs employed in public school districts in Minnesota, the districts’ duration of use of PLCs, and district barriers teachers and administrators have encountered when implementing PLCs

Silicon device performance measurements to support temperature range enhancement

Semiconductor power devices are typically rated for operation below 150 C. Little data is known for power semiconductors over 150 C. In most cases, the device is derated to zero operating power at 175 C. At the high temperature end of the temperature range, the intrinsic carrier concentration increases to equal the doping concentration level and the silicon behaves as an intrinsic semiconductor. The increase in intrinsic carrier concentration results in a shift of the Fermi level toward mid-bandgap at elevated temperatures. This produces a shift in devices characteristics as a function of temperature. By increasing the doping concentration higher operating temperatures can be achieved. This technique was used to fabricate low power analog and digital devices in silicon with junction operating temperatures in excess of 300 C. Additional temperature effects include increased p-n junction leakage with increasing temperature, resulting in increased resistivity. The temperature dependency of physical properties results in variations in device characteristics. These must be quantified and understood in order to develop extended temperature range operation

The Capitalization of Seller Paid Consessions

Using a hedonic pricing model, we analyze the capitalization of total seller paid discount points and closing costs into the price of a house. We hypothesize that sellers are concerned about the sales price net of total seller paid concessions (SPNC), rather than the exact terms of the transaction. Since the SPNC is easily ascertained in the negotiation process, we further hypothesize that total seller paid concessions (TSPC) are fully capitalized into the sales price. To test this hypothesis, sales price is regressed on a set of control variables including TSPC. In this framework, TSPC will be positive and not significantly different from one if concessions are fully capitalized. The empirical results provide support for the capitalization hypothesis. Negotiation strategies and study limitations follow from the empirical results.