Effects of borosilicate glass addition on the structure and dielectric properties of ZnTiO3 ceramics

ZnTiO₃ powders and borosilicate glass were made by sol-gel method, and then mixed for co-firing at low temperatures. The results show that the borosilicate glass was liquefied to improve the density of the ceramic during sintering. However, Zn₄O(BO₂)₆ and TiO₂ were formed if too much borosilicate glass was added (over 10 wt.%). The microwave dielectric properties of the ZnTiO₃ co-fired with borosilicate glass were also improved dramatically. With 5 wt.% borosilicate glass addition, ZnTiO₃ ceramics can be sintered at 850 °C and shows excellent microwave properties: 22.2 for dielectric constant, and 52,460 for Q × f value at a frequency of 6 GHz.     

Effects of dynamic impact on mechanical properties and microstructure of special stainless steel weldments

Variations in weld metal microstructure after impact at different strain rates for three weld metals, SAF 2507 DSS, SAF 2205 DSS and 254 SMO steel, are addressed. The twin grain forms that appear inside the γ grain of duplex stainless steel at low impact strain rates may be caused by adiabatic heat. The needle-like or thick streak-like twins occur in the γ grain of duplex stainless steel, caused by shear stress at a high strain rate. The impact induces dislocation loop formation in the γ phase of 254 SMO steel at low strain rate, but martensite is produced at a high strain rate. The chemical composition affects the stacking fault energy coupled with adiabatic heat to determine the final structure of the impact.     

Optimizing processes based on censored data obtained in repetitious experiments using grey prediction

The design of experiment (DOE) has been extensively adopted to increase the efficiency of designing new products and developing manufacturing processes in industry. However, some designed experiments cannot be completed for some uncontrollable reasons, such as cost and time restrictions or power damage during the experiment. Under such circumstances, incomplete data obtained in the experiment are referred to as censored data. Conventional approaches to analyzing censored data are computationally complex and frequently depend on assumptions of the normality of data. This study presents a procedure for analyzing the censored data obtained in repetitious experiments using the grey system theory. The proposed procedure does not make any statistical assumption and is less conceptual and computationally complex than current methods. Two experiments – one conventional experiment with type II censoring and one Taguchi experiment with type I censoring – are performed to demonstrate the effectiveness of the proposed procedure.     

A buyer-vendor EOQ model with changeable lead-time in supply chain

In this paper, we discuss a EOQ model on Stackelberg game in supply chain, that is, a distribution channel system contains one supplier and a single retailer, and the supplier in the channel holds monopolistic status, in which he not only owns cost information about the retailer but also has the decision-making right of the lead time. Under this circumstance, the optimal lead time and order cycle time of the supplier and the retailer, respectively, are investigated, and approximate solutions for then are derived. The analysis is made by numerical data that it’s likely to bring the supplier and the retailer profits and losses by controlling the lead time.     

Towards a better understanding of data models through themultilingual database system

An approach to the design of a database system, the multilingual database system (MLDS), has been proposed and implemented. MLDS is a single database system that can execute may transactions written respectively in different data languages and support many databases structured correspondingly in various data models, i.e. DL/I transactions on hierarchical databases, CODASYL-DML transactions on network databases, SQL transactions on relational databases, and Daplex transactions on functional databases. The authors describe MLDS, focusing on its motivation and structure. It is shown how MLDS, by providing an integrated environment for experimenting with data models and data languages, also serves as a testbed that provides insight to data models and data-model semantics, using qualitative and quantitative techniques. Related work on data-language comparison and analysis is indicated     

Altered responding to cholecystokinins and dopaminergic agonists following 6-hydroxydopamine treatment in rats.

In 5 experiments with 265 male Wistar albino rats, production of lesions in the brain dopamine (DA) system by intraventricular injection of 6-hydroxydopamine (6-OHDA) resulted in increased responses to subcutaneous apomorphine (0.5 mg/kg) and reduced responses to methamphetamine (0.15 mg/kg). It also made Ss increase responding to intracerebroventricular (icv) cholecystokinin octapeptide (CCK-8; 0.5–2 μg) and reduce responding to cholecystokinin tetrapeptide (CCK-4; 0.5–2 μg). Response changes were quantified by measuring the level of general activity. Results indicate that DA dysfunction not only affected DA receptor sensitivity but also the sensitivity of the CCK system. The response to CCK-8 was partially blocked by a selective CCK-8 antagonist, proglumide (5 μg, icv), a result suggesting the involvement of the CCK-8 receptor system. Results indicate that manipulation of 1 neuronal system could induce sensitivity changes in another closely related system. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A co-rotational formulation for nonlinear dynamic analysis of curved euler beam

A co-rotational finite element formulation for the dynamic analysis of a planar curved Euler beam is presented. The Euler-Bernoulli hypothesis and the initial curvature are properly considered for the kinematics of a curved beam. Both the deformational nodal forces and the inertial nodal forces of the beam element are systematically derived by consistent linearization of the fully geometrically nonlinear beam theory in element coordinates which are constructed at the current configuration of the corresponding beam element. An incremental-iterative method based on the Newmark direct integration method and the Newton-Raphson method is employed here for the solution of the nonlinear dynamic equilibrium equations. Numerical examples are presented to demonstrate the effectiveness of the proposed element and to investigate the effect of the initial curvature on the dynamic response of the curved beam structures.     

Congenital muscular dystrophy: report of one case

A case is reported of a newborn who presented with generalized hypotonia shortly after delivery. Creatine kinase (CK) was highly elevated. Muscle biopsy of the rectus femoris muscle revealed varying sized muscle fibers, displacement by fat and connective tissues, necrosis and regeneration of the muscle fibers. Magnetic resonance imaging (M.R.I.) of the brain showed normal development, compatible with the patient's age. Congenital muscular dystrophy was diagnosed from clinical manifestations, laboratory findings, and the results of muscle biopsy.     

Active devices under CMOS I/O pads

Active devices, including electrostatic discharge protection devices and ring-oscillator circuits, under CMOS I/O pads are investigated in a 130 nm full eight-level copper metal complementary metal-oxide-semiconductor process, using fluorinated silicate glass (FSG) low-k inter-metal dielectric. The high current I-V curve measured in the second breakdown trigger point (V/sub t2/, I/sub t2/) of ESD protection devices under various metal level stack structures, shows that i) I/sub t2/ depends very weakly on the number of metal levels used, as expected given specific junction power dissipation criteria; and ii) V/sub t2/ increases with the number of metal level stacks of I/O pads because of increased dynamic impedance due to the presence of more metal levels, as clarified by a simple RC model. Moreover, no noticeable degradation in the speed of the ring-oscillator circuit, as measured for a variety of test structures subjected to bonding mechanical stress, thermal stress by temperature cycling and DC electrical stress by transmission line pulse, as well as AC electrical stress by capacitive-coupling experiments. Accordingly, active devices under CMOS I/O pads are independent of bonding pad metal level structures.     

The rolling texture of iron of different purities

Deformation texture of 90% cold rolled iron of various purities was studied by pole figure measurements from which complete orientation distribution functions ODF were calculated using series expansion including the zero range method. The texture type consists of two mutually perpendicular orientation tubes which can be idealized as ( 110 )//RD and ( 111 )//ND in accordance with microstructural investigations which revealed two types of microstructures corresponding to these idealized fibres. The intensity superposition of the two fibres yields a maximum density in slightly deviating positions especially in the vicinity of the intersection of the two tubes which may be idealized as ( 110 ) 30° ND fibre component. The texture of the high-purity iron is nearest to the ( 111 )//ND fibre. Within this general texture type, two subtypes can be distinguished corresponding to high-purity iron on the one hand and the low-purity materials on the other. The texture of the high-purity iron at 90% of deformation still corresponds to the low-degree type of the lower-purity materials which is attributed to the occurrence of dynamic recovery in the high-purity iron.