The paper focuses on the application possibilities of the newly presented voltage differencing active building block called voltage differencing differential difference amplifier. Using this active element, a multifunction frequency filter is designed featuring the possibility of mutually independent control of quality factor Q and characteristic frequency \(\omega _0\) by means of active elements. The structure of the filter is based on the idea of the Akerberg-Mossberg (AM) filter, i.e. the integrators in the structure are always realized only by two active elements. This fact results in better phase compensation for the filter. Compared to the AM opamp based filter, the newly proposed structure features high-impedance inputs, low-impedance output, and all basic frequency responses. The performance of the proposed structure has been verified by SPICE simulations using the TSMC \(0.18\,\upmu \hbox {m}\) level-7 SCN018 CMOS process parameters with \(\pm 0.9\,\hbox {V}\) supply voltage. 相似文献
In the framework of context awareness within the home, our team is currently assessing the unobtrusive detection of inhabitants' activity through the monitoring of their use and consumption of electricity. The objective is to develop a system for the remote monitoring of large populations of elderly people living independently at home. To be readily deployable on the field, such a system must be minimally intrusive both for the home environment and for the field professionals (paramedics and social workers) visiting the patients at home. We carried out two successive field experiments to evaluate and to improve our system designed to deliver a single index of daily activity. The first experiment involved 13 elderly persons over a nine-month period (84,240 h data recorded) and the second one 12 elderly over six months (51,840 h). We evaluated both the relevance of the index and the acceptability of the system as a whole. We discovered that electrical activity is a kind of unique "signature" of each person's activity. Moreover, this profile provides unexpected information on the health status of the subject. We confirmed that the system was unobtrusive and well accepted both by the subjects and by the professionals involved. Our unique index of activity, and its trend over time, can provide timely information to the professionals on the patient. 相似文献
Motivated by the possibility of modifying energy levels of a molecule without substantially changing its band gap, the impact of gradual fluorination on the optical and structural properties of zinc phthalocyanine (FnZnPc) thin films and the electronic characteristics of FnZnPc/C60 (n = 0, 4, 8, 16) bilayer cells is investigated. UV–vis measurements reveal similar Q‐ and B‐band absorption of FnZnPc thin films with n = 0, 4, 8, whereas for F16ZnPc a different absorption pattern is detected. A correlation between structure and electronic transport is deduced. For F4ZnPc/C60 cells, the enhanced long range order supports fill factors of 55% and an increase of the short circuit current density by 18%, compared to ZnPc/C60. As a parameter being sensitive to the organic/organic interface energetics, the open circuit voltage is analyzed. An enhancement of this quantity by 27% and 50% is detected for F4ZnPc‐ and F8ZnPc‐based devices, respectively, and is attributed to an increase of the quasi‐Fermi level splitting at the donor/acceptor interface. In contrast, for F16ZnPc/C60 a decrease of the open circuit voltage is observed. Complementary photoelectron spectroscopy, external quantum efficiency, and photoluminescence measurements reveal a different working principle, which is ascribed to the particular energy level alignment at the interface of the photoactive materials. 相似文献
Mobile peer-to-peer networking (MP2P) is a relatively new paradigm compared to other wireless network technologies. In the last 10–15 years, it has gained tremendous popularity because of its usefulness in applications such as file sharing over the Internet in a decentralized manner. Security of mobile P2P networks represents an open research topic and a main challenge regarding the vulnerability of these networks and their convenience to different security attacks such as black hole, Sybil, etc. In this work, we analyze the black hole attack in wireless P2P networks using the AODV as the routing protocol. In a black hole attack, a malicious node assumes the identity of a legitimate node, by creating forged answers with a higher sequence number, and thus forces the victim node to prioritize it as a relay node. We propose a solution based on a modification of the AODV routing protocol, taking into account the behavior of each node participating in the network. The performances of our proposal are evaluated by simulation.
Here, we describe the procedure of a DNA extraction method from maize starch including the method??s validation by in-house and interlaboratory tests. The amplifiable amount of maize DNA tested by real-time PCR was used as parameter for evaluating our method. The practical (i.e. relative) limit of detection (LOD) was used as key criterion for assessing the suitability of the extraction method with respect to genetically modified organism analysis. In a round-robin test with ten participating laboratories, satisfactory results were achieved with practical LODs in the range of 0.1?% with three native maize starch materials. In-house tests showed that this protocol??with an additional purification step??can also be applied for extracting DNA from chemically or enzymatically modified starch. 相似文献
An upflow microbial fuel cell (UMFC) system with a U-shaped cathode inside the anode chamber was developed and produced a maximum volumetric power of 29.2 W/m3 at a volumetric loading rate of 3.40 kg COD/(m3 day) and an operating temperature of 35 degrees C while feeding sucrose continuously. The Coulombic efficiency decreased from 51.0% to 10.6% with the increase in the volumetric loading rate from 0.57 to 4.29 kg COD/(m3 day). In addition, the lab-scale UMFC maintained soluble chemical oxygen demand (COD) removal efficiencies exceeding 90% and volatile fatty acid concentrations of approximately 40 mg/L, indicating efficient wastewater treatment. The analysis of impedance spectroscopy, generated by fitting experimental data into an equivalent circuit, revealed that at a volumetric loading rate of 3.40 kg COD/(m3 day) the overall internal resistance was 17.13 omega. This internal resistance was composed of electrolyte resistance (8.62 omega), charge-transfer resistance (7.05 omega), and diffusion resistance (1.46 omega). Electrolyte resistance dominated throughout the entire range of loading rates. In addition, impedance spectroscopy demonstrated that both the anodic and the cathodic charge-transfer resistances were important limiting factors. To further improve the power output of the UMFC, we must reduce the electrolyte resistance by optimizing reactor configuration, reduce the anode charge-transfer resistances by selecting superior anodic microbiota, and reduce the cathodic charge-transfer resistance by exploring sustainable and efficient catalysts. 相似文献
The CYH2 gene from Saccharomyces cerevisiae containing one 510 bp intron is spliced inefficiently. We have shown previously that a non-conserved sequence within the intron is responsible for this low splicing efficiency. Using synthetic oligonucleotides comprising the identified region we show in this report that a very short region contains the specificity to act negatively on the splicing efficiency of the CYH2 gene. Furthermore, this sequence influences the splicing efficiency only when it is placed close to the 5' splice site of the gene. Investigations with chimeric CYH2/beta-actin genes show that this sequence acts independent from its natural surroundings. We propose that this sequence might interact with splicing factor(s). 相似文献
This study aimed to assess the influence of two label conditions on the acceptance of boar meat. A central location test was conducted with 145 consumers each assessing 4 pieces of pork loin. 相似文献