Bipolar Processing Research Articles

Bioleaching and immobilizing of copper and zinc using endophytes coupled with biochar-hydroxyapatite: Bipolar remediation for heavy metals contaminated mining soils

Copper and zinc are toxic heavy metals in soils that require development of feasible strategies for remediation of contaminated soils around the mine areas. In this study, the processing conditions and mechanisms of immobilization and bioleaching for remediation of highly contaminated soils with heavy metals are investigated. Soil remediation is carried out using a bioleaching-immobilization bipolar method. The results show that LSE03 bacteria provide efficient leaching result and immobilization on Cu2+ and Zn2+. Among the bacterial metabolites, cis, cis-muconic acid and isovaleric acid play major roles in the bioleaching process. The bacterial extracellular polymeric substances are rich in a variety of organic acids that show a significant decrease in content after the adsorption process, indicating that all of these substances are involved in the binding of heavy metals. Characterization of the endophytes and immobilizing agents with FTIR, TEM-mapping, and XPS techniques reveal the ability of both bacteria and composites to adsorb Cu–Zn as well as the main functional groups of –OH, –COOH, –PO43–, and –NH. According to the heavy metals species analyses, competitive adsorption experiments, and bioleaching desorption experiments, it is planned to carry out the bipolar remediation of contaminated soil through immobilization followed by bioleaching process. After bipolar remediation processing, 97.923% and 96.387% of available Cu and Zn are respectively removed. Soils fertility significantly increases in all cases. Our study provides a green, practical, and environmentally friendly treatment method for soils contaminated with high concentrations of heavy metals.

C-reactive protein and affective inhibition in bipolar disorder

BackgroundIndividuals with bipolar disorder (BD) experience cognitive and affective processing deficits that often persist beyond the remission of acute mood symptoms. One possible biological mechanism for these deficits involves the potential effects of chronic low-grade peripheral inflammation on brain function. Peripheral inflammation has been associated with reduced executive functioning and memory performance, as well as altered reward processing in BD, but whether it is also implicated in cognitive-affective processing remains unknown. MethodPeripheral inflammation was measured by serum C-reactive protein (CRP) in 119 adults with BD I or II, age 18–65. All participants completed the Affective Go/No-Go Task, a measure of cognitive-emotional processing. Correlations of CRP with discrimination of and response times to Negative, Positive, and Neutral words were performed before and after adjustment for severity of residual depressive symptoms and other demographic and clinical characteristics associated with inflammation. ResultsIncreased CRP was significantly associated with reduced negative target discriminability, which was also significantly reduced compared to positive and neutral target conditions. Additionally, greater CRP was associated with faster response times for both negative hits and commissions, as well as positive commissions. ConclusionsThis study adds to existing research demonstrating associations between inflammation and cognition or reward sensitivity and motivation separately in BD, by raising the possibility that inflammation is also implicated in the integration of cognitive-affective processing. Assessment of these associations over time is warranted to determine involvement of inflammation and cognitive-emotional processing in course of illness and identify critical periods for possible modulation of inflammation.

CODAS methods for multiple attribute group decision making with interval-valued bipolar uncertain linguistic information and their application to risk assessment of Chinese enterprises’ overseas mergers and acquisitions

Bipolar fuzzy set theory has been successfully applied in some areas, but there are situations in real life which can’t be represented by bipolar fuzzy sets. However, all the existing approaches are unsuitable to describe the positive and negative membership degree an element to an uncertain linguistic label to have an interval value, which can reflect the decision maker’s confidence level when they are making an evaluation. In order to overcome this limit, we propose the definition of interval-valued bipolar uncertain linguistic sets (IVBULSs) to solve this problem based on the bipolar fuzzy sets and uncertain linguistic information processing models. In this paper, we extend the traditional information aggregating operators to interval-valued bipolar uncertain linguistic sets (IVBULSs) and propose some IVBUL aggregating operators. Then, we extend the CODAS method to solve multiple attribute group decision making (MAGDM) issues with interval-valued bipolar uncertain linguistic numbers (IVBULNs) based on these operators. An example for risk assessment of Chinese enterprises’ overseas mergers and acquisitions (M&As) is given to illustrate the proposed methodology.

ПІДВИЩЕННЯ ДОВГОВІЧНОСТІ СФЕРИЧНИХ ШАРНІРІВ ЗМІЦНЕННЯМ КУЛЬОВИХ ПАЛЬЦІВ СТАТИКО-ІМПУЛЬСНОЮ ОБРОБКОЮ

The possibility of improving the durability of spherical sliding hinges due to the strengthening of the incomplete spherical surface of ball fingers by static-pulse processing is considered. The review of recent researches and publications was carried out and promising directions for increasing the durability of ball joints were established. The influence of the shock system parameters on the shape and amplitude of the impact pulse is analyzed. The recommended range of correlations of the geometric parameters of the elements of the shock system is established. On the basis of theoretical and experimental studies, a model of shock system with static load of the boom and tool, as well as a bipolar shock treatment scheme is proposed. The method of calculating the parameters of the shock system and the mathematical dependences have been developed. The model of the mechanical impulse generator of shock impact machine with static load of the boom and the tool according to the bipolar impact processing scheme is proposed. The method and algorithm of calculation of parameters of the generator of mechanical impulses of the device for strengthening of incomplete spherical surfaces is developed.

Delayed bipolar and ganglion cells neuroretinal processing in regular cannabis users: The retina as a relevant site to investigate brain synaptic transmission dysfunctions

Cannabis use is widespread worldwide, but the impact of smoking cannabis regularly on brain synaptic transmission has only been partially elucidated. The retina is considered as an easy means of determining dysfunction in brain synaptic transmission. The endocannabinoid system is involved in regulating retinal synaptic transmission, which might also be affected by tobacco. Previous preliminary results have shown impairments in retinal ganglion cell response in cannabis users. Here, we test the extent to which earlier retinal levels—bipolar cells and photoreceptors—are affected in cannabis users, i.e. by the association of tobacco and cannabis.We recorded pattern (PERG) and flash (fERG) ERG in 53 regular cannabis users and 29 healthy controls. Amplitude and peak time of P50 and N95 (PERG) and of a- and b-waves (fERG) were evaluated. Cannabis users showed a significant increase in PERG N95 peak time and in fERG light-adapted 3.0 b-wave peak time, compared with controls (p = 0.0001 and p = 0.002, respectively; Mann-Whitney U test). No significant difference was found between the groups in terms of wave amplitude (p = 0.525 and p = 0.767 for the N95 and light-adapted 3.0 b-wave amplitude respectively; Mann-Whitney U test). The results demonstrated delayed ganglion and bipolar cell responses in cannabis users. These results reflect a delay in the transmission of visual information from the retina to the brain. This retinal dysfunction may be explained by an effect of cannabis use on retinal synaptic transmission. Main limitations of these results concern tobacco and alcohol use that differed between groups. The consequences of these anomalies on visual perception along with the molecular mechanisms underlying this retinal dysfunction should be explored in future human and animal studies.

Altered Sensory Phenomena Experienced in Bipolar Disorder.

Altered Sensory Phenomena Experienced in Bipolar Disorder.

Design and Implementation of Bipolar Digital Signal Acquisition and Processing System Based on FPGA and ACPL-224

This paper proposes new approaches for designing a bipolar DS acquisition system to reduce the harm of external factors on equipment, as well as fulfill system requirements at the veracity and reliability of the equipment to quickly connect. The design method chosen is ACPL-224 for chip of the interface about data acquisition on the FPGA device, including system principle, interface circuit logic, the method of data processing, and so forth. Now that this method has been applied, it has achieved good results, including extending the system’s adaptive range of external signal and enhancing the efficiency of the interface to quickly connect.

Two routes for bipolar information processing, and a blind spot in between

This position paper addresses the question of why, whilst the human brain is apparently geared to process information of mixed polarities, human reasoners sometimes fail to deal appropriately with simple instances of mixed evidence or mixed prospects. From a dual-process perspective of thinking, two mental routes for bipolar information processing are identified. One is biologically acquired and evolution tied, and the other is the product of a cultural elaboration of rational norms. In between the two routes, a blind spot accounts for failures of bipolar information processing. © 2008 Wiley Periodicals, Inc.

215 – Bipolar disorder and processing of emotional faces: differential brain activation in patients and their 1st degree relatives

215 – Bipolar disorder and processing of emotional faces: differential brain activation in patients and their 1st degree relatives

Gaussian activation functions using Markov chains

We extend, in two major ways, earlier work in which sigmoidal neural nonlinearities were implemented using stochastic counters. 1) We define the signal to noise limitations of unipolar and bipolar stochastic arithmetic and signal processing. 2) We generalize the use of stochastic counters to include neural transfer functions employed in Gaussian mixture models. The hardware advantages of (nonlinear) stochastic signal processing (SSP) may be offset by increased processing time; we quantify these issues. The ability to realize accurate Gaussian activation functions for neurons in pulsed digital networks using simple hardware with stochastic signals is also analyzed quantitatively.

Gunter Schwuttke

Gunter Schwuttke

Inverter plasma discharge system

We have developed a bipolar pulsed dc glow plasma discharge system using an inverter power supply. A target of the developed system is a low-cost surface modification operated in a low background pressure region (10 1–10 3 Pa) obtained with rotary pumps. In this pressure region, breakdown voltages for most gases have minimum values without the help of magnetic fields like a magnetron. Accordingly, we can use simple discharge electrodes such as parallel plates that would be extended for large area processing. These electrodes are driven by the bipolar voltage pulses including dc bias components which would drive both positive ions and electrons. A composition of the developed discharge system is shown. Voltage and current waveforms and emission light signals are measured to demonstrate a discharge operation. Initial applications of the developed system using a bipolar pulse processing technique are proposed.

RF circuits and advanced A/D converters

The fast growing demand for mobile communications has lead to numerous development efforts in chip technology for the RF front-end of these systems. Recent improvements in bipolar processing and dimension reduction have raised silicon operating frequency up to 2 GHz. Low power mobile applications present a good opportunity for submicron BiCMOS process. The first part of this presentation will describe some advanced BiCMOS RF architectures and present some experimental results. The A/D converter generally remains the most critical block of an integrated acquisition chain, as regards the whole channel performance and especially for low power applications. This presentation will be focused on the design of efficient submicron CMOS delta-sigma A/D converters dedicated to general purpose signal processing applications and some experimental results will also be discussed.

Bipolar-compatible epitaxial poly for smart sensors: stress minimization and applications

This paper presents the optimization of the fabrication process for bipolar-compatible epipoly for micromachining applications. The use of an epitaxial reactor to grow polysilicon enables the growth of monocrystalline silicon (for bipolar electronics) and polysilicon on top of oxkle (for MEMS) in a single deposition step. However, after bipolar processing the early structures showed compressive strain in the epipoly layer, which then required careful MEMS design. The cause of this compressive strain is shown to be the oxidation steps in the bipolar process. The occurrence of this strain can be explained by the presence of oxygen in the epipoly. An alternative processing technique, where the epipoly is doped using implantation and shielded from oxidation by a nitride layer during further bipolar processing, yields epipoly layers without compressive strain. The full thermal budget of the bipolar process is used to diffuse and activate the implanted epipoly dopant. Functional thermal and electrostatic sensor and actuator structures have been fabricated to demonstrate the feasibility of this process

An integrated silicon colour sensor using selective epitaxial growth

Abstract An integrated silicon colour sensor using selective epitaxial growth (SEG) of silicon is presented. The sensor concept is based on the strong wavelength dependence of the photon absorption coefficient in silicon in the visible spectral range. Photocurrents of three vertically stacked photodiodes, with the desired position and thickness of the depletion regions, represent full tricolorimetric information. The upper two photodiodes are integrated in the 1.2 μ thick SEG silicon, which is grown on the conventional epilayer where the lower photodiode is placed. High-quality SEG silicon with pattern-insensitive growth has been achieved. Diodes formed in SEG silicon show an ideality factor close to 1, provided the edges are oriented in the [100] directions. The first prototypes of the colour sensor have been fabricated, and measured spectral responses give reasonable agreement with simulation. Using the SEG process together with low-temperature deposited masking oxide (TEOS), maintains compatibility with standard bipolar processing and enables the integration of read-out circuitry to realize a truly smart sensor.

Self-linearized analog differential self-electro-optic-effect device

We describe, demonstrate, and characterize an analog self-electro-optic-effect device that gives a difference between two optical output powers that is linearly proportional to an electrical or an optical drive. Such a device should permit bipolar (positive and negative) processing in novel image processing arrays. The device is able to operate over a range of more than 4 orders of magnitude of optical power from 50 nW to 2.5 mW, corresponding to uniform incident intensities as low as 3.3 mW/cm(2). The frequency response (3-dB limit) varies linearly from 7 kHz at 1-µW absorber power to 3.5 MHz at 1 mW of absorbed powers.

Integrated instrumentation amplifier for the phase readout of piezoresistive strain gauges

An integrated instrumentation amplifier combined with a bandpass filter has been fabricated in a bipolar process for the phase readout of piezoresistive sensors. Changes in the resistance can be measured directly using an ac-operated bridge configuration. A special technique has been employed to convert these changes into a phase angle relative to the excitation signal. The instrumentation amplifier should have a very high Common-Mode Rejection Ratio (CMRR) at a relatively high bridge operating frequency (100 kHz) in order to actually exploit the advantages of this readout method. The filter should have a well-determined phase behavior to prevent a change in the frequency from affecting the output phase angle. Special emphasis has been placed on the compatibility between micromachining technologies in silicon and bipolar processing, so that a fully integrated smart silicon micromechanical sensor can be made.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Analog differential self-linearized quantum-well self-electro-optic-effect modulator

We describe an analog self-electro-optic-effect device that gives a difference between two optical output powers that is linearly proportional to electrical or optical drive, permitting bipolar processing in novel image-processing arrays. The device is able to operate over a range of more than four orders of magnitude optical power, from 50 nW to 2.5 mW, corresponding to uniform incident intensities as low as 3.3 mW/cm(2).

A heated membrane for a capacitive gas sensor

Interdigital capacitors covered with a gas-sensitive layer are suitable for the integration of gas sensors with microelectronic technologies. They can be temperature stabilized by mounting them on a heated membrane. Usually one faces the problem of significant temperature gradients across the membrane for large-area sensors. In this work a heater arrangement capable of maintaining an almost even temperature distribution on the heated membrane is presented. An analytical approach and finite-element simulations are used to estimate heating power distribution for a square-shaped membrane. A test chip was designed and fabricated. The fabrication process is fully compatible with standard bipolar processing.

High contrast marks for e-beam direct write made by reactive ion etching

Square wells, etched in silicon (111) substrates by reactive ion etching, are characterized as alignment marks for direct write electron beam lithography. In addition to compatibility with subsequent silicon bipolar processing steps, the contrast of the marks is comparable to etched V-shaped holes in silicon (100). The mark properties are investigated systematically by varying the size, the depth and the slope of the edges. Marks with a size smaller than 10 μm and a depth larger than about 1 μm have a sufficient contrast (>0.1) for automatic detection by a Philips EBPG-3 after deposition of 0.4 μm SiO 2 and 0.25 μm Ti/ 0.2 μm Pt/0.6 μm Au. Although the slope of the mark edges degrades after deposition of the layers, the marks allow an overlay accuracy between 50 to 100 nm. The application of the marks is not restricted to silicon (111) since the fabrication of the marks only depends on the anisotropic nature of reactive ion etching and this technique is applicable to many other substrates.