Spatial problem solving in a dual runway task by normal and septal rats.

On the Maier 3-table spatial integration task, the addition of a dual runway configuration did not disrupt the successful performance of 10 normal male Long-Evans hooded rats or improve the deficit of 10 Ss with septal lesions. Both groups displayed a preference for the outside runway configuration during exploration. During testing, however, septal-lesioned Ss retained this preference, whereas normal Ss attempted solution by using the inside runway configuration. This fact, in addition to the apparent lack of habituation during exploration, suggests that septal-lesioned Ss did not acquire a spatial representation of the test situation. It is suggested that the inability of septal-lesioned rats in spatial situations is due to an inability to form rather than to use spatial maps. The cognitive representation of a problem space is considered in relation to route complexity, response biases, and self-corrections. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Only connections: A critique of semantic networks.

Examines theories that assume that semantic networks account for the mental representation of meaning. Similarities and divergencies between the theories are assessed, and it is argued that as a class, these theories remain too powerful to be refuted by empirical evidence. The theories are also confronted by a number of problematical semantic phenomena that arise because networks deal with the connections between concepts rather than with their connections to the world. Although semantic network theories specify a form for the mental representation of meaning and also account for intensional properties and relations, they are not designed to specify the extensions of words or expressions, and their accounts of inference are inadequate. The solution to these problems could be embodied in a new network system, but such a system would differ in both structure and function from current network theories. (83 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increased Cement Grinding Efficiency by Using High-Efficiency Separators

High-efficiency classifiers improve the grain size distribution of the finished cement and reduce grinding power requirements. Theoretical calculations indicate potential power savings of up to one-third at the main mill motor when applying high-efficiency classifiers instead of conventional separators at a cement fineness of 15 percent residue at 0.030 mm. The most commonly used separators of conventional and high-efficiency design are presented and briefly characterized. Data on actual performance of grinding systems are stated which indicate that some 15 percent of the grinding system's power consumption can be saved when applying high-efficiency classifiers instead of conventional separators at 3500-4000 cm2/g (Blaine) cement fineness.     

On the estimation of the size of a subgroup in industrial production: The test gate method

Even in high quality manufacturing, some units may exhibit deviations. Although such units are not actually nonconforming to usage requirements when sent to the field, the deviations may lead to a reduced lifetime. It is therefore imperative to estimate the number of units bearing such deviations for risk assessment. Standard sampling methods are inefficient for this purpose. As an efficient alternative, we suggest the test gate method. The method is demonstrated on two practical examples and we provide an empirical model with stochastic extensions. We discuss the test gate method and customary alternatives, in particular control sampling.     

Advanced nanofibrous textile-based dressing material for treating chronic wounds

In the present work, an electrospun nanofibrous textile composed of polyurethane (PU), sodium bicarbonate (\(\hbox {NaHCO}_{3}\)) and pantothenic acid (PA) is developed for treating chronic wounds. Wounds are a common health problem and in particular, the chronic wounds such as vascular ulcers, diabetic ulcers and pressure ulcers cause a large number of morbidity and mortality. The main problems of the chronic wounds are prolonged inflammation phase and presence of acidic environment. These events deactivate the operation of growth factors and also the progression of natural healing mechanism. Hence, various types of advanced textile-based dressings are developed to address the clinical complications associated with chronic wound management. The prepared electrospun scaffolds were characterized to study their physicochemical and haemocompatible properties. The scanning electron microscopy micrographs depicted continuous, smooth-interconnected nanofibrous morphology of PU–NaHCO\(_{3}\)–PA scaffolds. The Fourier transform infrared spectroscopy spectra indicated the addition of NaHCO\(_{3}\) and PA-based hydrophilic chemical groups, which significantly enhanced the wettability of the composites. Further, the PU–NaHCO\(_{3}\)–PA composite membrane inferred to have a highly porous structure with the mean porosity of 79.4 ± 4.8%, which may provide a conducive environment for adherence and proliferation of skin cells. The composite scaffold also offers a highly haemocompatible surface by delaying coagulation of blood through contact activation pathways and by limiting red blood cells damage. Therefore, the excellent physicochemical properties, blood compatibility and the delivery of PA are anticipated to speed up the impaired healing process of chronic wounds.     

Torsional bridge setup for the characterization of integrated circuits and microsensors under mechanical shear stress

We present a torsional bridge setup for the electro-mechanical characterization of devices integrated in the surface of silicon beams under mechanical in-plane shear stress. It is based on the application of a torsional moment to the longitudinal axis of the silicon beams, which results in a homogeneous in-plane shear stress in the beam surface. The safely applicable shear stresses span the range of ±50 MPa. Thanks to a specially designed clamping mechanism, the unintended normal stress typically stays below 2.5% of the applied shear stress. An analytical model is presented to compute the induced shear stress. Numerical computations verify the analytical results and show that the homogeneity of the shear stress is very high on the beam surface in the region of interest. Measurements with piezoresistive microsensors fabricated using a complementary metal-oxide-semiconductor process show an excellent agreement with both the computational results and comparative measurements performed on a four-point bending bridge. The electrical connection to the silicon beam is performed with standard bond wires. This ensures that minimal forces are applied to the beam by the electrical interconnection to the external instrumentation and that devices with arbitrary bond pad layout can be inserted into the setup.     

Rare earth (RE: Nd,Dy, Ho,Y, Yb,and Sc) aluminosilicates for joining silicon carbide components

Six different types of glass 12.18 RE₂O₃‐22 Al₂O₃‐65.82 SiO₂ (mol %) where RE: Nd, Dy, Ho, Y, Yb, and Sc were tested for joining silicon carbide (SiC) components. The different types of glass vary in their thermal properties but they are similar in their behavior for the joining process when a laser‐based heating technology was used. The quality of the joints was characterized by microscopic analysis, mechanical tests, and measurements of tightness. Annealing experiments were conducted at temperatures in the range of the glass transition and crystallization allowing an assessment of the compositions for usability as glass and as glass‐ceramic interlayers. Five of the investigated compositions can be recommended for application up to temperatures of 900°C. The Y‐ and Yb‐based compositions guarantee a high joint quality at temperatures up to 1200°C. The high temperature assessment was based on tightness and microstructural analyses of the joints after the annealing procedures. The results can be transferred to joining processes with lower heating and cooling rates.