Sulfidation treatment of copper-containing plating sludge towards copper resource recovery

The present study is concerned with the sulfidation treatment of copper-containing plating sludge towards copper resource recovery by flotation of copper sulfide from treated sludge. The sulfidation treatment was carried out by contacting simulated or real copper plating sludge with Na(2)S solution for a period of 5 min to 24 h. The initial molar ratio of S(2-) to Cu(2+) (S(2-) to Me(2+) in the case of real sludge) was adjusted to 1.00, 1.25 or 1.50, while the solid to liquid ratio was set at 1:50. As a result, it was found that copper compounds were converted to various copper sulfides within the first 5 min. In the case of simulated copper sludge, CuS was identified as the main sulfidation product at the molar ratio of S(2-) to Cu(2+) of 1.00, while Cu(7)S(4) (Roxbyite) was mainly found at the molar ratios of S(2-) to Cu(2+) of 1.50 and 1.25. Based on the measurements of oxidation-reduction potential, the formation of either CuS or Cu(7)S(4) at different S(2-) to Cu(2+) molar ratios was attributed to the changes in the oxidation-reduction potential. By contrast, in the case of sulfidation treatment of real copper sludge, CuS was predominantly formed, irrespective of S(2-) to Me(2+) molar ratio.     

Effects of Non-Opioid Analgesics on the Cell Membrane of Skin and Gastrointestinal Cancers

Skin and gastrointestinal cancer cells are the target of research by many scientists due to the increasing morbidity and mortality rates around the world. New indications for drugs used in various conditions are being discovered. Non-opioid analgesics are worth noting as very popular, widely available, relatively cheap medications. They also have the ability to modulate the membrane components of tumor cells. The aim of this review is to analyze the impact of diclofenac, ibuprofen, naproxen, acetylsalicylic acid and paracetamol on skin and gastrointestinal cancers cell membrane. These drugs may affect the membrane through topical application, at the in vitro and in vivo level after oral or parenteral administration. They can lead to up- or downregulated expression of receptors, transporters and other molecules associated with plasma membrane. Medications may also alter the lipid bilayer composition of membrane, resulting in changes in its integrity and fluidity. Described modulations can cause the visualization of cancer cells, enhanced response of the immune system and the initiation of cell death. The outcome of this is inhibition of progression or reduction of tumor mass and supports chemotherapy. In conclusion, non-opioid analgesics may be used in the future as adjunctive therapy for the treatment of these cancers.     

A real-time DOA-based smart antenna processor

We designed, built, and tested a real-time processor for a direction-of-arrival-based smart antenna GSM 1800 base station with eight half-wavelength spaced antenna elements. Its processing steps include direction-of-arrival (DOA) estimation, user identification, tracking, beamforming, and signal reconstruction. We demonstrate that the accuracy of DOA estimation is not of primary concern, but the robustness is. This can be assessed by a new parameter, the estimation range. Tracking of reliable user DOAs only, increases the robustness against interference. Our tracking concept is compatible with frequency hopping. We quantify the benefits of smart antennas by the statistics of the gain in carrier-to-interference ratio (C/I) and in signal-to-noise ratio (SNR), both measured at the 90 or 99% levels with actual transmitted data. In an urban environment with large angular spread and overlap of user and interferer signals, the C/I gain is as high as 18 dB. Interferer ing increases the C/I gain only slightly, but enhances robustness against angular spread, particularly if broad s are applied. Separating SNR gain in its contributions due to beamforming and diversity gives valuable insight into the way of operation. In uplink, the processor can exploit angular diversity. The entire suite of processing steps is done within less than 1 ms, demonstrating that sophisticated DOA-based smart antenna processing is feasible in real time. Our solution does not require any change in the GSM standard.     

Martensitic zirconium alloys: Influence of chemical composition on creep characteristics

Results of an extensive investigation of creep in martensitic zirconium alloys are summarized with the aim to show the influence of chemical composition on the main creep characteristics — the steady state creep rate and the time and strain to fracture. The activation energy of creep and the parameter of stress sensitivity of steady state creep rate are determined and possible creep mechanisms as well as creep strengthening mechanisms are discussed. The time to fracture $\text{t}{}_{\mathrm{f}}$, is related to the steady state creep rate ge_s through the Monkman-Grant relation as modified by Dobe? and Milic?ka. The creep fracture shows features different from those of “classical” intergranular cavitation creep fracture. Most probably the creep fracture is controlled by the same deformation mechanism as the creep.     

Preliminary study of behavioral and safety effects of driver dependence on a warning system in a driving simulator

Warning systems are being developed to improve traffic safety using visual, auditory, and/or tactile displays by informing drivers of the existence of a threat in the roadway. Behavioral and safety effects of driver dependence on such a warning system, especially when the warning system is unreliable, were investigated in a driving-simulator study. Warning-system accuracy was defined in terms of miss rate (MR) and positive predictive value (PPV) (PPV is the fraction of warnings that were correct detections). First, driver behavior and performance were measured across four warning-system accuracy conditions. Second, the authors estimated the probability of collision in each accuracy condition to measure the overall system effectiveness in terms of safety benefit. Combining these results, a method was proposed to evaluate the degree of driver dependence on a warning system and its effect on safety. One major result of the experiment was that the mean driving speed decreased as the missed detection rate increased, demonstrating a decrease in driver's reliance on warnings when the system was less effective in detecting threats. Second, both the acceleration-pedal and brake-pedal reaction times increased as the PPV of the warning system decreased, demonstrating a decrease in driver compliance with warnings when the system became more prone to false alarms. A key implication of the work is that performance is not necessarily directly correlated to warning-system quality or trends in subjective ratings, highlighting the importance of objective evaluation. Practical applications of the work include design and analysis of in-vehicle warning systems.     

Developing Concept-Based User Interfaces for Scientific Computing

Although drawings and graphs can express complex concepts, such methods can't be computationally analyzed. Researchers have developed visual approaches and paradigms that scientists can use to capture and represent scientific models in a computational form that they can link to and integrate with data sets and applications.     

Integrating objective and subjective hazard risk in decision-aiding system design

A generalized model is presented to incorporate objective (hard) and subjective (soft) hazard information in automated decision-aiding systems. The model may be used with more than one hazard, of more than one type, in a given problem. Uncertainties in state measurements, dynamics, hazard extent, and hazard severity are included, as is the consideration of the fact that different operators may have different concepts of what is an acceptable or unacceptable risk. By examining the tradeoffs created by these uncertainties, appropriate decision thresholds can be selected. Using an aviation case study, information gained from observation of aircraft behavior in the presence of weather was used to develop a model of weather as a soft hazard. This information can then be used in a decision aid to provide feedback on route acceptability.     

Directional macro-cell channel characterization from urbanmeasurements

We measured the angular power distribution at the mobile station in downtown Paris at 890 MHz. The transmit antenna was omnidirectional and placed high above rooftops. The receiver antenna, a 21×41 element rectangular synthetic array, was located on the roof of a van. The refined high-resolution evaluation method, particularly robust against nonstationary signal components, allows an angular resolution of better than 1° in both azimuth and elevation and a delay resolution of 33 ns. Combined angular/temporal domain measurements are crucial for the understanding of the propagation mechanisms. The evaluated sites showed strongly street-dominated propagation. We found a combined circular and rectangular distribution of scatterers around the mobile station in street-dominated environments. Propagation over the roofs was significant; typically 65% of energy was incident with elevation larger than 100. Our results corroborate the hypothesis on the importance of multiple reflections/diffractions in urban macro cells. We explain this behavior by two reasons: narrow streets favoring a canyon effect and strong scatterers without line-of-sight (LOS) to the mobile station