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International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering Small-Signal Amplifier with JFETs in Triple Darlington Topology
No full textABSTRACT: New circuit model of small-signal amplifier with three identical JFETs in Triple Darlington topology is proposed and qualitatively analyzed for the first time. Unlike CS-JFET amplifiers, the voltage gain of the proposed circuit is found considerably higher than unity. This amplifier successfully scales signal excursions swinging in 1-35mV range at 1KHz frequency. In wide-band performance range (7.59MHz bandwidth), the proposed amplifier simultaneously produces high voltage and current gains (18.039 and 150.729 respectively) with considerably low THD (0.22%). These properties offer a flexible application range to the proposed circuit as high-voltage-gain wide-band amplifier in 42Hz-7MHz frequency range. An additional biasing resistance R A (ranging in 250Ω-100KΩ) is to be essentially used in the proposed circuit to maintain its voltage/current amplification property. This amplifier can also be tuned in specific range of audible frequency which explores its suitability to use in Radio and TV receiver stages. Small-signal AC analysis of the circuit, variations in voltage gain as a function of frequency and different biasing resistances, temperature dependency of performance parameters like voltage gain, bandwidth, current gain and total harmonic distortion of the amplifier are widely studied to observe a wide spectrum of qualitative performance
18. See supporting on Science Online for detailed methods. 19
No full textparticles have substantially more of them. If these low coordination number corner and/or edge positions are implicated as active sites for toluene oxidation, then their relatively higher occurrence in the Au-Pd/C sample could account for the superior performance displayed by this catalyst. Another possible explanation could lie in the difference in the distribution of Au-Pd particle morphologies found in the two catalyst samples. The Au-Pd/C catalyst predominantly has multiply twinned (icosahedral and decahedral) particles, which tend to have {111} facet terminations. In comparison, the Au-Pd/TiO 2 materials show an increased fraction of cuboctahedral and singly/doubly twinned particles, which exhibit mixed {100}/{111} facet terminations. Hence, the increasing proportion of {100}-type facets in the Au-Pd/TiO 2 sample correlates with a lowering of the catalytic activity, and preparation strategies need to avoid them. In a final set of experiments, we investigated the stability of the catalysts, because it is crucial to confirm that high-activity catalysts can be reused. With the Au-Pd/TiO 2 catalyst, the reaction was stopped after 7 hours, and the catalyst was recovered by decantation. Identical conversion was obtained on reuse of the Au-Pd/TiO 2 catalyst A critical design rule is that the range of interparticle interactions (hydrophobic attraction and electrostatic repulsion) must be short relative to particle size and that the interactions must be reversible. Clustering then favors densely packed structures with at most six nearest neighbors per particle, in contrast to the more open and less ordered structures formed by particles whose interaction range is larger (13). At very low salt concentrations, particles repel one another electrostatically, whereas at high salt concentrations, van der Waals forces cause the particles to aggregate irreversibly (19). Therefore, we consider intermediate concentrations of monovalent salt at which amphiphilic clusters self-assemble (20). If the hydrophobic patch is too small, assembly admits clusters composed of at most four particles. However, increase in patch size allows such clusters to grow into larger assemblies, with two constraints: First, particles must approach closely enough to experience hydrophobic attrac
Status Quo and Proposals in the Selection of Teaching Materials for Foreign Language Majors at Chinese Universities-An Integrated Course in Elementary Japanese as an Example
No full textWith the considerable amount of textbooks and teaching materials published in China, both administrators and teachers are still puzzled when they are selecting proper materials for the students majoring in foreign languages. Selection of teaching materials will have a direct impact on both program building and outcome of the graduates in the program. This paper attempts to discuss the current situation of teaching material selection for foreign language majors, analyze the factors in material selection, and put forward some proposals of how to select proper teaching materials for foreign language majors
Group 47 Twitter Political Influence -Presidential Election 2012 CS224W Final Report
No full textAbstract With the growing use of online social media, it's use in politics is starting to become extremely important. Analysis of the wealth of data contained in these online social networks can be used to gather more data about people's political leanings than ever before. In this paper, we analyze the spread of information during the 2012 presidential election to determine the most important topics to the US population. We want to be able to determine which political issue has larger outbreaks during the political campaigns and is thus more important in determining the presidential election. Ranking the importance of political issues to the US population will reveal how to better maximize a political campaign and possibly predict election results. Gathering twitter data on 8 different topics from the most recent presidential election we analyze what the data can tell us, and how it may possibly be used. We see that by measuring the number of mentions of specific topics we can accurately match the top issues identified in the independent research polls. We also identify the size of the graphs for all political issues as following a power law distribution. We then perform some sentiment analysis and show that the public's opinion on a candidates issues can be analyzed from the tweets gathered. Finally we show that using the temporal data associated with all of the tweets we can see trends that demonstrate peaks of interest in the campaign, and could possibly be used to help predict the outcome of elections
Effect of Fennel (Foeniculum Vulgare Mill.) Used as a Feed Additive on The Egg Quality of Laying Hens Under Heat Stress
No full textABSTRACT In this study, one hundred and twenty 40-wk-old White Leghorn laying hens were submitted to two different thermal conditions (24° C vs. 34° C) and were fed three levels (0, 10, or and 20 g/kg of diet) of fennel fruits (Foeniculum vulgare Mill.) as a feed additive in. This study was carried out according to a factorial design consisting of two temperatures and three fennel levels with five 5 replicates each (n = 2 × 3 × 5). Performance, egg production, egg quality, and oxidative product levels (malondialdehyde, MDA, and carbonyl) in the eggs were measured before and after heat exposure. The results showed that the tested temperatures did not affect egg production (p>0.05), but the production of eggs with broken shell and feed intake were affected by heat stress (p<0.05). The different temperatures also affected egg quality (p<0.05), reducing egg weight (EW), eggshell thickness (EST), eggshell strength (ESS), Haugh units (HU), albumen height (AH), and albumen weight (AW). At the high environmental temperature, MDA and carbonyl egg contents increased (p<0.05), while fennel consumption reduced the values of both parameters. Heat stress had no effect on yolk cholesterol levels (p>0.05), but increased yolk triglyceride levels. Hens that consumed fennel presented lower yolk cholesterol and triglyceride levels (p<0.05). In general, fennel fruit influenced egg yolk cholesterol and triglyceride contents, and because of its antioxidant properties, it may alleviate the adverse effects of heat stress on laying hens
Primary pulmonary melanoma: the unexpected tumour
No full textSUMMARY A 62-year-old woman was referred to our pulmonology team with exertional dyspnoea and chest tightness of 2 months duration. Her medical history included cervical cancer and thyroid nodules. Imaging studies showed collapse of left upper lobe. Fiberoptic bronchoscopy unveiled an endoluminal lesion and bronchial biopsy displayed features of melanoma. She denied a history of melanoma or excision of lesions of skin, mucous membranes or the eye. A thorough evaluation including combined positron emission tomography with CT scan excluded other possible sites of primary melanoma, but there was a metastasis in a thoracic vertebra. Palliative radiotherapy of the spine was performed. Chemotherapy initiation with dacarbazine was postponed by the appearance of a malignant pleural effusion, confirmed by pleural fluid cytology. After four cycles chemotherapy was discontinued due to disease progression. The patient is still alive with a follow-up of 12 months, currently on best supportive care. BACKGROUN
MR (2010) Modelling and analysis of planar cell polarity
No full textAbstract Planar cell polarity (PCP) occurs in the epithelia of many animals and can lead to the alignment of hairs, bristles and feathers; physiologically, it can organise ciliary beating. Here we present two approaches to modelling this phenomenon. The aim is to discover the basic mechanisms that drive PCP, while keeping the models mathematically tractable. We present a feedback and diffusion model, in which adjacent cell sides of neighbouring cells are coupled by a negative feedback loop and diffusion acts within the cell. This approach can give rise to polarity, but also to period two patterns. Polarisation arises via an instability provided a sufficiently strong feedback and sufficiently weak diffusion. Moreover, we discuss a conservative model in which proteins within a cell are redistributed depending on the amount of proteins in the neighbouring cells, coupled with intracellular diffusion. In this case polarity can arise from weakly polarised initial conditions or via a wave provided the diffusion is weak enough. Both models can overcome small anomalies in the initial conditions. Furthermore, the range of the effects of groups of cells with different properties than the surrounding cells depends on the strength of the initial global cue and the intracellular diffusion
Case Report Sensorineural Hearing Loss following Carbon Monoxide Poisoning
No full textA case study is presented of a 17-year-old male who sustained an anoxic brain injury and sensorineural hearing loss secondary to carbon monoxide poisoning. Audiological data is presented showing a slightly asymmetrical hearing loss of sensorineural origin and mild-to-severe degree for both ears. Word recognition performance was fair to poor bilaterally for speech presented at normal conversational levels in quiet. Management considerations of the hearing loss are discussed
Fruit-Enhanced Resistance to Microbial Infection Induced by Selective Laser Excitation
No full textTable grapes were irradiated with laser pulses at two different wavelengths: one selected at 302.1 nm, that is, resonant with the transresveratrol biphoton absorption band, and another selected at 300 nm, that is a nonresonant wavelength where transresveratrol two-photon absorption is negligible. Attenuated total re�ectance Fourier transformed infrared spectroscopic analyses of the irradiated grapes' skin showed an enhancement of polyphenols' content when the resonant wavelength was employed. Furthermore, microbiological analysis performed with nontreated (control), nonresonant, and resonantly irradiated grapes demonstrated how the last samples developed a signi�cantly lower number of colony forming units. Since the only difference between the two (resonant and nonresonant) irradiation conditions was just a couple of nanometres in the employed UV-B laser wavelengths, the germicidal effect should be considered very similar. As a result, the observed difference in the table grape resistance to microbial infection was attributed to a wavelength-dependent-induced photochemistry. Finally, the potentiality of this method to enhance the postharvest health status of table grapes is remarked