Hiring Qualified College Graduates: MIS Business Majors Versus Computer Science Majors

When decisions must be made regarding systems productivity and control trade-offs, many companies automatically opt for productivity improvement. However, critical functions, documentation, testing, and training are sometimes sacrificed. To establish a balance between these competing needs, MIS management should educate systems developers and users about the nature of and need for controls.     

同步、低EMI LED驱动器具有集成式开关和内部PWM调光能力

具有内部同步、2A开关的36V LED驱动器LT3922,是一款紧凑、通用的LED驱动器。     

Experimental and computational studies of bulk polymerization of styrene in the presence of N-(O-(1-phenylmethyl)oxy) phthalimide or cyclohexanone-O-(1-phenylmethyl)oxime

Summary Syntheses of potential initiators N-(O-(1-phenylethyl)oxy)phthalimide, N-(O-(1-phenylmethyl)oxy)phthalimide (POP), cyclohexanone-O-(1-phenylethyl)oxime, and cyclohexanone-O-(1-phenylmethyl)oxime (CHPO) are described. Bulk polymerization of styrene in the presence of POP or CHPO and molecular weight measurement by GPC indicate that the polymerization is not a living process. Ab initio calculations show that the C-O or O-N bond cleavage energies of POP and CHPO are close to each other (3: C-O: 46.4, O-N: 47.3 kcal/mol; 1: C-O: 46.9, O-N: 63.0 kcal/mol) and much higher than the similar analogs of 2,2,6,6-tetramethylpiperidinyloxy (TEMPO) (C-O: 20.9, O-N: 34.4 kcal/mol). The similar C-O and O-N bond cleavage energies of the synthesized initiators (POP/CHPO) indicate two possible cleavage pathways and may explain the non-living nature of the polymerization. These results may be helpful in finding future reversible terminator compounds for living polymerization. Received: 28 August 2000/Revised version: 5 December 2000/Accepted: 7 December 2000     

Developing and Maintaining an Inspection-Ready Pipeline Safety Program

For the past several decades, pipeline incidents have resulted in highly publicized accounts of property damage, environmental harm, neighborhood destruction, serious injury, and death.     

Evaluation of environmental design strategies for university buildings

ABSTRACT

This paper examines the performance of environmental strategies in seven recently constructed or refurbished university buildings in the UK. These buildings contain a range of administrative spaces, classrooms, libraries and studios, reflecting their often complex, multi-use, heterogeneous nature. The key features of each environmental strategy are described (including passive, mixed-mode or active systems), in the context of the occupants and spaces they serve and the level of interaction that they afford. Energy performance and occupant thermal comfort (assessed by user surveys) are analysed and compared with studies of other non-domestic buildings, which have typically focused on more predictable single administrative uses (e.g. government offices), and unusually effective operation scenarios (e.g. continuous monitoring by expert building managers). The paper concludes by examining two of the case studies that reflect an increasingly common model of ‘flexible’ environmental design in more detail, identifying key features of the strategies for each building that have had a significant impact on their performance. The design assumptions leading to these features will be explored, and key lessons identified, contributing towards the development of a more robust evidential basis for choosing appropriate environmental strategies for university and other non-domestic buildings in the UK.     

Improved fallow: growth and nitrogen accumulation of five native tree species in Brazil

Nitrogen (N) is the most important yield-limiting factor in agricultural systems, however, N application can lead to emissions and environmental problems such as global warming (N₂O) and groundwater contamination (NO₃ ^?). This study analyses the N balance, nitrogen-use efficiency, and N loss potential of conventional farming systems (arable farming, improved arable farming, and agroforestry) and organic farming systems (mixed farming, arable farming, and agroforestry) based on long-term field experiments in southern Germany. The effects of the conversion of farm structure and N management are identified. The conventional farming systems in this study were high N-input and high N-output systems. The conventional arable farming system had the lowest nitrogen-use efficiency and the highest N surplus. An optimised N management and the use of high-yielding crop varieties improved its nitrogen-use efficiency. The establishment of conventional agroforestry resulted in the reduction of N input, N output and N surplus, while maintaining high yields. The organic mixed farming system is characterised by a relatively high N input and N output, the accumulation of soil organic nitrogen, the highest nitrogen-use efficiency, and the lowest N surplus of all analysed systems. These good results can be attributed to the intensive farm N cycle between soil–plant–animal. The shift from organic mixed farming to organic arable farming system extensified the N cycle, reduced N input, crop yield and N output. The change from organic arable farming to organic agroforestry reduced the N input, increased the biomass yield, and remained the N surplus within an optimal range.     

Matched‐dual‐polymer electrochromic lenses,using new cathodically coloring conducting polymers,with exceptional performance and incorporated into automated sunglasses

Reported are syntheses of several new monomer precursors of cathodically coloring conducting polymers (CPs), based on a propylene dioxythiophene skeleton. These are shown to yield CPs—both as homopolymers and as copolymers—that are nearly “perfectly” matched electrochemically and electrochromically with a set of anodically coloring poly(aromatic amines), for use in dual‐polymer electrochromic lenses. Resulting dual‐polymer electrochromic lenses display very high light/dark contrast (typically up to 70/7% or 50/0.5% Transmission (integrated over visible spectrum, vs. air reference), Haze < 2%, very high cyclability (> 10 K cycles), multiyear shelf life, appealing transparent to dark‐blue‐black transition, and excellent optical memory. Dramatic lowering of switching time, from 8 to < 1 s, is demonstrated using unique applied‐potential algorithm resident on inexpensive Microcontroller chip. Working, practical dual‐polymer electrochromic spectacles are demonstrated with electrochromic lenses retrofitted to spectacles meeting ANSI Z87.1, GL‐PD 10–12 (U.S. military) specifications. These incorporate photosensor, rechargeable Li battery, Microcontroller, allow for automated operation. Ab‐initio‐design spectacles, also conforming to above specifications, are also demonstrated, with components seamlessly hidden within frame. To the best of our knowledge, the electrochromic lenses and sunglasses reported herein represent the best visible‐region electrochromic performance for dual‐polymer CP electrochromic systems to date and the first practical implementation in working sunglasses. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41043.     

The performance of a distributed combat simulation with the time warp operating system

This paper analyzes the performance of a discrete-event combat simulation executed on a parallel processor under control of the Time Warp Operating System. Time Warp is in a class of distributed simulation methods called Optimistic methods which have proven to be useful over a wide range of simulations. The combat simulation used for this performance study, called STB88, is a division-corps model incorporating a number of different types of computations. The speed-up for three versions of this model on the Caltech/JPL Mark III Hypercube and the BBN Butterfly parallel processors was measured relative to an efficient sequential execution of the same model on the same hardware. The results indicate that STB88 version 1 achieves a speed-up of 28.6 on 60 Mark III processors, while STB88 version 2 achieves a speed-up of 36.8 on 100 Butterfly processors. Version 3 of STB88 achieved a speed-up of 38.5 on 128 Mark III processors. The versions differed only in their interface to Time Warp. On the Butterfly, the sequential execution completed in 2 hours, while the 100 processor execution completed in 3.2 minutes.     

Product design: Formulation of a screen-printable sintering-type conductive paste

Due to the complexity of the screen-printing operation and the rheological behaviors of the screen-printable paste, such a paste is usually formulated by trial-and-error. In this report, a systematic procedure, based on heuristics and mechanistic models, for the design of a screen-printable paste is developed. The procedure is demonstrated by a case study of the formulation of a conductive paste of copper particles.