Pack boronizing of AISI H11 tool steel: Role of surface mechanical attrition treatment

The role of surface mechanical attrition treatment (SMAT) on pack boronizing of AISI H11 type tool steel is addressed. SMAT induced plastic deformation, enabled nanocrystallization at the surface, reduced the grain size and increased the volume fraction of non-equilibrium gain boundaries, increased the accumulation of defects and dislocations at the grain boundaries and within the grains. These features helped to promote the diffusion of boron during boronizing and increased the case depth and hardness of the borided layer. Duplex treatment on SMATed H11 steel samples helps to achieve a higher case depth when compared to the single stage treatment. The findings of the study suggest that SMAT can be used as a pre-treatment for boronizing of H11 tool steel.     

Investigation of thermodynamic properties of the binary system polyethylene glycol/CO2 using new methods

The solubility and diffusivity of CO₂ in polyethylene glycols (PEGs) of different molecular weight measured by two different methods are discussed in the present work. Before solubility measurements, the melting temperatures of PEG with different molecular weights were determined by means of differential scanning calorimetry. For the purpose of the present study a temperature of 343 K was chosen as the working temperature for both employed methods since all studied polymers are in liquid state at this temperature. All samples were analyzed at isothermal conditions and in the pressure range from 0 MPa up to 30.0 MPa. A set of absorption experiments on the PEG/CO₂ systems was performed using an external balance method. In order to validate results obtained by the new method they were compared to the data obtained at the same process conditions by a method using magnetic suspension balance (MSB).     

Teachers’ attitude regarding the use of ICT. A factor reliability and validity study

Current research examines the need for design and validation of a unifactorial scale to measure attitudes of university teachers with regard to ICT. The main goal of this study is to achieve a simple scale, composed of a single factor contributing a clearly reliable measure with acceptable content and factorial validity. A case study is presented, which has been developed with the teaching staff of the University of Salamanca (Spain). In this case study, an expert content validation was done at a first stage. After that, an attitude scale regarding the usage of ICT in teaching was applied with a representative sample of teachers (N = 2329; n = 161). An individual analysis of the items was made with the obtained results and then a Cronbach’s alpha based reliability test was carried out to show the internal consistency of the survey. Finally, an exploratory and confirmatory factor analysis was applied to prove its structural soundness and unifactoriality. The main conclusion of this paper is to offer to the scientific community a tool with adequate psychometric properties that gives added pedagogical value to the introduction of ICT in higher education teaching.     

Effect of packing density on flame propagation of nickel-coated aluminum particles

The combustion-wave propagation of nickel-coated aluminum particles is studied theoretically for packing densities in the range of 10–100% of the theoretical maximum density. Emphasis is placed on the effect of packing density on the burning properties. The energy conservation equation is solved numerically and the burning rate is determined by tracking the position of the flame front. Atomic diffusion coefficients and reaction rate of isolated nickel-coated aluminum particles are input parameters to the model. The burning behaviors and combustion wave structures are dictated by the heat transfer from the flame zone to the unburned region. Five different models for the effective thermal conductivity of the mixture are employed. The impact of radiation heat transfer is also assessed. As a specific example, the case with a particle size of 79 μm is considered in detail. The burning rate remains nearly constant (<1 cm/s) up to a packing density of 60%, and then increases sharply toward the maximum value of 11.55 cm/s at a density of 100%. The Maxwell–Eucken–Bruggeman model of thermal conductivity offers the most accurate predictions of the burning rate for all loading densities.     

A methodology for estimating the value of privacy in information disclosure systems

In many types of information systems, users face an implicit tradeoff between disclosing personal information and receiving benefits, such as discounts by an electronic commerce service that requires users to divulge some personal information. While these benefits are relatively measurable, the value of privacy involved in disclosing the information is much less tangible, making it hard to design and evaluate information systems that manage personal information. Meanwhile, existing methods to assess and measure the value of privacy, such as self-reported questionnaires, are notoriously unrelated of real–world behavior. To overcome this obstacle, we propose a methodology called VOPE (Value of Privacy Estimator), which relies on behavioral economics' Prospect Theory (Kahneman & Tversky, 1979) and valuates people's privacy preferences in information disclosure scenarios. VOPE is based on an iterative and responsive methodology in which users take or leave a transaction that includes a component of information disclosure. To evaluate the method, we conduct an empirical experiment (n = 195), estimating people's privacy valuations in electronic commerce transactions. We report on the convergence of estimations and validate our results by comparing the values to theoretical projections of existing results (Tsai, Egelman, Cranor, & Acquisti, 2011), and to another independent experiment that required participants to rank the sensitivity of information disclosure transactions. Finally, we discuss how information systems designers and regulators can use VOPE to create and to oversee systems that balance privacy and utility.     

新疆油田原油交接计量存在的问题及改造对策

新疆油田大部分原油采用静态交接,存在很多不足,且满足不了油田信息自动化建设需要,因此对原油静态交接进行动态交接计量改造。对新疆油田原油动态交接改造过程中遇到的问题进行分析,并提出解决对策,对其他油田的动态交接改造有一定的指导作用。     

Evolution of phases in Al55Ni30Pd15 alloy at temperatures up to 600 °C

The originally as-cast Al₅₅Ni₃₀Pd₁₅ alloy was investigated during continuous heating from room temperature to 600 °C and after annealing at 600 °C for respective 455, 2650, and 4050 h. In the investigation the synchrotron X-ray diffraction and the high-resolution scanning electron microscopy inclusive of the energy-dispersive X-ray spectroscopy were used. In all the investigated conditions β-(Ni,Pd)Al (Pm3m) and Al₃(NiPd)₂ (P3m1) phases were identified. After 2650 h of annealing the former phase was found to be separated into two isostructural modifications differing from one another in Pd- and Ni-contents. The annealing for 455 h contributed to the decrease of lattice parameters in the Al₃NiPd phase compared to the original as-cast condition.     

An experimental analysis on the evolution of the transient tip penetration in reacting Diesel sprays

Schlieren imaging has helped deeply characterize the behavior of Diesel spray when injected into an oxygen-free ambient. However, when considering the transient penetration of the reacting spray after autoignition, i.e. the Diesel flame, few studies have been found in literature. Differences among optical setups as well as among experimental conditions have not allowed clear conclusions to be drawn on this issue. Furthermore, soot radiation may have a strong effect on the image quality, which cannot be neglected.     

From dynamic capabilities to ERP enabled business improvements: The mediating effect of the implementation project

This study explores whether an Enterprise Resource Planning (ERP) implementation project mediates the relationship between dynamic pre-adoption capabilities and ERP-enabled business improvements. The results from our field survey of large ERP adopters in Austria suggest that the effects of the two out of three selected dynamic capabilities are dependent on the properties of the underlying organizational transformation project. While external information acquisition and IT governance capabilities are fully mediated by the performance of the ERP implementation project, decision making only directly impacts business capabilities. These results further our understanding about the role of the implementation project for ERP value creation and the different natures of capability relationships. We call for more research on co-presence conditions related to dynamic capabilities and IT transformation project performance.     

PUBLIC OPINION,TRADITION, AND INFORMATION HALF-LIFE†

The information needs of a complex society are not met by an information-flow technology invented and developed in traditional societies. This article provides a theoretical framework derived from modern systems theory by which to understand the technology of public opinion policy formation in guidance operations of a complex society. Qualitative models of information flow systems are presented together with a discussion of the kind of society each information flow technology produces. Three are considered: tradition-based information-flow societies, managed information-flow societies (Utopian and elitist), and cybernetic issue-based information-flow societies.