Influence of simultaneous variation in size of type, width of line, and leading for newspaper type.

A speed of reading technique was employed with 820 readers to determine the effect on legibility of simultaneous variation of type size, line width, and leading for Excelsior newspaper type. 9 typographical variations were compared with text set in 8-point type in a 12-pica line width with 2-point leading. Results revealed that 7-, 8-, and 9-point type in a 12-pica line width with 2-point leading were read most rapidly and equally fast. But text in relatively long lines, very short lines, and small type size, or combinations of these with little or no leading were read significantly slower than the standard. Judgments for relative legibility and pleasingness revealed a reader preference for 8- or 9-point type with 2-point leading in a line width of 12 picas (12 or 18 picas for 9-point type). Text in relatively long or short lines, small type size, and no leading received low ratings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recent studies of eye movements in reading.

Grouping the studies under the general topic headings of techniques of measurement, analysis of the reading process, training to improve eye movements, typography and eye movements, and eye movements and fatigue the author reviews the relevant research literature which has appeared since January, 1945. In general there has been a dimunition of interest in this area. However, there has appeared a large amount of work on visual fixation, speed of eye movements, reaction time of the eye, oculomotor efficiency, and vision during eye movements. There is a need for more basic research. 72-item bibliography. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increased Uptake of Chelated Copper Ions by Lolium perenne Attributed to Amplified Membrane and Endodermal Damage

The contributions of mechanisms by which chelators influence metal translocation to plant shoot tissues are analyzed using a combination of numerical modelling and physical experiments. The model distinguishes between apoplastic and symplastic pathways of water and solute movement. It also includes the barrier effects of the endodermis and plasma membrane. Simulations are used to assess transport pathways for free and chelated metals, identifying mechanisms involved in chelate-enhanced phytoextraction. Hypothesized transport mechanisms and parameters specific to amendment treatments are estimated, with simulated results compared to experimental data. Parameter values for each amendment treatment are estimated based on literature and experimental values, and used for model calibration and simulation of amendment influences on solute transport pathways and mechanisms. Modeling indicates that chelation alters the pathways for Cu transport. For free ions, Cu transport to leaf tissue can be described using purely apoplastic or transcellular pathways. For strong chelators (ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA)), transport by the purely apoplastic pathway is insufficient to represent measured Cu transport to leaf tissue. Consistent with experimental observations, increased membrane permeability is required for simulating translocation in EDTA and DTPA treatments. Increasing the membrane permeability is key to enhancing phytoextraction efficiency.     

Functionalized [2]Rotaxanes

The synthesis of a series of dumbbell-shaped compounds, which can act as a host (e.g., toward alkali metal cations) and as a guest (e.g., toward cyclobis(paraquat-p-phenylene)) in a supramolecular context is described. The self-assembly of [2]pseudorotaxanes and [2]rotaxanes, in which cyclobis(paraquat-p-phenylene) encircles polyether chains intercepted in their middles by a hydroquinone ring and terminated at each end by 12-crown-4, 15-crown-5, monoaza-18-crown-6, 18-crown-6, or adamantyl groups, is achieved using either threading, clipping, or slipping procedures. All the [2]pseudorotaxanes and [2]rotaxanes are characterized in solution by spectroscopic means and, in the case of two of the [2]rotaxanes, by X-ray crystal structures in the solid state. In the presence of metal ions, [2]pseudorotaxanes carrying 12-crown-4 or 15-crown-5 stoppers can be disassembled in solution. The research shows how one kind of complexation can affect another kind of complexation—manifesting itself in a physical change in the system and so acting as a prototype of a potential molecular device.     

Effect of Dissolved Gases on Spray Evaporative Cooling with Water

An experimental investigation of the effect of nondegassed water used to cool a solid surface is presented. The solid surface is subjected to thermal radiant input from three panels positioned above it. The water is deposited on the surface in the form of a sparse spray with droplets of about 10 µl. Previous experiments with degassed water are compared to a new set of experiments. In addition, the effect of dissolved gases (air) is quantified in terms of the overall transient thermal behavior of the solid. A lower steady-state average temperature is achieved when gases remain in the water. This result suggests that the configuration of the liquid droplets on the surface and the radiant heat input into the droplet are altered by the gas bubbles in the deposited droplet. This information provides insight into fire control mechanisms by automatic sprinkler systems.     

Parents' job insecurity affects children's academic performance through cognitive difficulties.

The authors developed and tested a model in which children who perceive their parents to be insecure about their jobs are distracted cognitively, which in turn affects their academic performance negatively. Participants were 102 female and 18 male undergraduates (mean age?=?18 years), their fathers (mean age?=?49 years), and their mothers (mean age?=?47 years). Students completed questionnaires measuring perceived parental job insecurity, identification with parents, and cognitive difficulties; 3 months later, they also reported their midyear grades. Fathers and mothers each completed questionnaires assessing their job insecurity. Support for the model was obtained using LISREL 8, and as predicted, children's identification with their mothers and fathers moderated the relationship between their perceptions of their mothers' and fathers' job insecurity and their own cognitive difficulties. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Occult parasitic energy loss in heat engines

When a reversible process, such as the compression of a working gas, is treated as a feedback mechanism coupling adjacent heat engine cycles, analysis reveals a parasitic energy loss unaccounted for by traditional theory. Including this feedback‐induced energy loss in the derivation of an efficiency relation yields predictions that reproduce experimental observations with sufficient accuracy as to propose this effect as being the primary source of disparity between practice and existing theory. Further, it is shown that both the Carnot and Curzon–Ahlborn efficiency relations are derivable special cases of this more general result. Finally, it is postulated that substantial gains in thermodynamic efficiency may be affected in practical heat engines, including increases on the order of 30% in internal combustion engines, by frustrating these feedback mechanisms through simple mechanical modifications. Copyright © 2007 John Wiley & Sons, Ltd.     

Characteristics and performance of the Sunna high dose dosemeter using green photoluminescence and UV absorption readout methods

Growth in the use of ionising radiation for medical sterilisation and the potential for wide-scale international food irradiation have created the need for robust, mass-producible, inexpensive, and highly accurate radiation dosemeters. The Sunna dosemeter, lithium fluoride injection-moulded in a polyethylene matrix, can be read out using either green photoluminescence or ultraviolet (UV) absorption. The Sunna dosemeter can be mass-produced inexpensively with high precision. Both the photoluminescent and the UV absorption reader are simple and inexpensive. Both methods of analysis display negligible humidity effects, minimal dose rate dependence, acceptable post-irradiation effects, and permit measurements with a precision of nearly 1% 1sigma. The UV method shows negligible irradiation temperature effects from -30 degrees C to +60 degrees C. The photoluminescence method shows negligible irradiation temperature effects above room temperature for sterilisation dose levels and above. The dosimetry characteristics of these two readout methods are presented along with performance data in commercial sterilisation facilities.