Table shortcuts [Laplace transform]

A useful, but seldom used, Laplace transform pair is revisited. Despite the usefulness of this pair, it has generally been omitted from textbooks that introduce the one-sided Laplace transform. Its generality helps one see the roles of damping factor, natural frequency, and a zero in shaping the transient response of a second order system     

Processing effects on the surface properties of α-lactose monohydrate assessed by inverse gas chromatography (IGC)

As mechanically induced processing effects on powdered materials are primarily manifested in small regions on the particle surface, they frequently remain undetected by routine chemical and physical measurement techniques. Inverse gas chromatography was employed in this study to characterize the surface properties of -lactose monohydrate and determine any changes induced by milling and blending. Results highlighted the potential of this technique to detect and quantify surface energy differences induced by milling and blending and demonstrated how a second unit operation often achieves its effects by means of disrupting flaws caused during the first process. Studies of the flow properties revealed how the bulk behavior of powdered materials can change depending upon processing history, further emphasizing the importance of surface characterization in understanding the behavior of powdered materials.     

Effects of caffeine on human health

Caffeine is probably the most frequently ingested pharmacologically active substance in the world. It is found in common beverages (coffee, tea, soft drinks), in products containing cocoa or chocolate, and in medications. Because of its wide consumption at different levels by most segments of the population, the public and the scientific community have expressed interest in the potential for caffeine to produce adverse effects on human health. The possibility that caffeine ingestion adversely affects human health was investigated based on reviews of (primarily) published human studies obtained through a comprehensive literature search. Based on the data reviewed, it is concluded that for the healthy adult population, moderate daily caffeine intake at a dose level up to 400 mg day^-1 (equivalent to 6 mg kg^-1 body weight day^-1 in a 65-kg person) is not associated with adverse effects such as general toxicity, cardiovascular effects, effects on bone status and calcium balance (with consumption of adequate calcium), changes in adult behaviour, increased incidence of cancer and effects on male fertility. The data also show that reproductive-aged women and children are 'at risk' subgroups who may require specific advice on moderating their caffeine intake. Based on available evidence, it is suggested that reproductive-aged women should consume ≤ 300 mg caffeine per day (equivalent to 4.6 mg kg^-1 bw day^-1 for a 65-kg person) while children should consume ≤ 2.5 mg kg^-1 bw day^-1.     

Concentrations of bisphenol A in the composite food samples from the 2008 Canadian total diet study in Quebec City and dietary intake estimates

A total of 154 food composite samples from the 2008 total diet study in Quebec City were analysed for bisphenol A (BPA), and BPA was detected in less than half (36%, or 55 samples) of the samples tested. High concentrations of BPA were found mostly in the composite samples containing canned foods, with the highest BPA level being observed in canned fish (106 ng g(-1)), followed by canned corn (83.7 ng g(-1)), canned soups (22.2-44.4 ng g(-1)), canned baked beans (23.5 ng g(-1)), canned peas (16.8 ng g(-1)), canned evaporated milk (15.3 ng g(-1)), and canned luncheon meats (10.5 ng g(-1)). BPA levels in baby food composite samples were low, with 2.75 ng g(-1) in canned liquid infant formula, and 0.84-2.46 ng g(-1) in jarred baby foods. BPA was also detected in some foods that are not canned or in jars, such as yeast (8.52 ng g(-1)), baking powder (0.64 ng g(-1)), some cheeses (0.68-2.24 ng g(-1)), breads and some cereals (0.40-1.73 ng g(-1)), and fast foods (1.1-10.9 ng g(-1)). Dietary intakes of BPA were low for all age-sex groups, with 0.17-0.33 μg kg(-1) body weight day(-1) for infants, 0.082-0.23 μg kg(-1) body weight day(-1) for children aged from 1 to 19 years, and 0.052-0.081 μg kg(-1) body weight day(-1) for adults, well below the established regulatory limits. BPA intakes from 19 of the 55 samples account for more than 95% of the total dietary intakes, and most of the 19 samples were either canned or in jars. Intakes of BPA from non-canned foods are low.     

Predicting faculty job centrality in communication

Data from 1,581 faculty members affiliated with 98 doctoral-granting Communication programs in the United States were analyzed to determine normative publication rates and predictors of position centrality in the faculty hiring network. The Communication Institute for Online Scholarship (CIOS) database was used to measure publication frequency in refereed journals. Position centrality was measured using a Communication program’s relative position in the hiring network as established by Barnett, Danowski, Feeley, and Stalker (2010). The average publication frequencies by academic rank were as follows: assistant professors averaged 2.29 articles (N = 441, SD = 3.29); associate professors averaged 6.69 articles (N = 497, SD = 5.77); professors averaged 10.92 articles (N = 542, SD = 12.09). Results from multiple regression analyses indicate the number of publications for faculty members and position centrality of where one earned his or her doctoral degree significantly predicted current position centrality. Publication numbers for one’s advisor and year of earned doctorate did not emerge as significant predictors of position centrality.     

Measuring Quality in Communication Doctoral Education Using Network Analysis of Faculty‐Hiring Patterns

This research examines the prestige of doctoral degree programs in communication based on a network analysis of program links among 102 doctoral programs and 2,194 tenure‐track faculty members. University of Wisconsin–Madison (Journalism & Mass Communication), Michigan State University (Communication), University of Texas‐Austin (Communication Studies), and University of Illinois (Speech Communication) are the top four programs in terms of placement centrality in communication. Centrality of programs in this network, measured by out‐degree, closeness centrality, and eigenvector indices, is positively related to subjective prestige ratings of faculty and department chairs ( Neuendorf, Skalski, Atkin, Kogler‐Hill, & Perloff, 2007 ). Faculty size was also related to network centrality and interdisciplinarity of program. Further, centrality of programs is positively related to program prestige controlling for faculty size.     

Water: A critical resource in the thermoelectric power industry

Water availability represents a growing concern for meeting future power generation needs. In the United States, projected population growth rates, energy consumption patterns, and demand from competing water use sectors will increase pressure on power generators to reduce water use. Water availability and use also exhibit strong regional variations, complicating the nature of public policy and technological response.     

An update on DOE's Phase II and Phase III mercury control technology R&D program

The U.S. Department of Energy's National Energy Technology Laboratory, under the Office of Fossil Energy's Innovations for Existing Plants Program, carried out a comprehensive Hg research and development program for coal-fired power generation facilities since the mid-1990s. Working collaboratively with the U.S. Environmental Protection Agency, the Electric Power Research Institute, power plant operators, state and local agencies, and a host of research organizations and academic institutions, the Program identified the major factors that affect mercury speciation and capture in coal combustion flue gas and funneled this knowledge into the development of a suite of mercury control technologies for the diverse fleet of U.S. coal-fired power plants. The high performance observed during full-scale field testing has given coal-fired power plant operators the confidence to begin deploying technology. As of March 2009, more than 130 full-scale activated carbon injection systems have been ordered by the U.S. coal-fired power generators. These contracts include both new and retrofit installations and represent over 55 GW of coal-based electric generating capacity.     

Cosmetics and the esthetic patient and laboratory communication

With increasing consumer awareness of the innovative procedures available for cosmetic dentistry, this area of practice is growing rapidly and has become an excellent source for patient referrals. Unfortunately, it can also be a large source of stress for the practitioner. Esthetics has been described by The Pocket Oxford Dictionary as "the philosophy of beautiful"; its perception varies from individual to individual. In the field of dentistry, there are criteria which define one tooth as being more esthetic than another and one individual's smile as more pleasing than another. However, that which is esthetically pleasing to the clinician may not be esthetically pleasing to the patient.     

BIT: A Very Compact Scheme System for Microcontrollers

We present a compact implementation of Scheme for microcontrollers that includes a real-time garbage collector. The compiler runs on a normal workstation and produces byte-code from the source program. A smart linker links the byte-code with the runtime module. We demonstrate that with this system it is clearly possible to run realistic Scheme programs on a microcontroller with as little as 3 to 4 KB of RAM. Programs that access the whole Scheme library require only 13 KB of ROM. As a byproduct of this research, we designed a novel space-efficient real-time GC algorithm.