This paper presents an adaptive Improved Recycling Folded Cascode (IRFC) amplifier with improved gain, high slew rate, high phase margin and reduced power consumption. The proposed design is implemented using 180 nm technology with a supply voltage of 1.8 V and a capacitive load of 1 pF. The proposed design is compared with basic two stage op-amp, cascode amplifier and conventional recycling folded cascode amplifier (RFC). Analysis demonstrates that the flexible structure of IRFC with adaptive biasing shows an improvement in gain to 87.74 dB, approximately three times enhancement in slew rate to 53.8 V/µs when compared with the design specifications. The phase margin was observed to be 64.86°. The design also reports an increase in output swing. The gain increases to 109 dB when a cascode stage is added to the IRFC structure.
Delineation of groundwater potential zones (GWPZ) has been performed for a coastal groundwater basin of eastern India. The groundwater potential zone index (GWPZI) map is generated by using Analytic Hierarchy Process (AHP) from different influencing features, e.g., Land Use/Land Cover (LU/LC), soil (S), geomorphology (GM), hydrogeology (HG), surface geology (SG), recharge rate (RR), drainage density (DD), rainfall (RF), slope (Sl), surface water bodies (SW), lineament density (LD), and Normalized Difference Vegetative Index (NDVI). Recharge rate values are estimated from hydrological water balance model. Overlay weighted sum method is used to integrate all thematic feature maps to generate GWPZ map of the study area. Four zones have been identified for the coastal groundwater basin [very good: 36.39 % (273.53 km2, good: 43.57 % (327.47 km2), moderate: 18.27 % (137.30 km2), and poor: 1.77 % (13.27 km2)]. Areas in north to south-west and south-east direction show very good GWPZ due to the presence of low drainage density. GWPZ map and well yield values show good agreement. Sensitivity analysis reveals that exclusion/absence of rainfall and lineament density increases the poor groundwater potential zones. Omission of hydrogeology, soils, surface geology, and NDVI show maximum increase in good GWPZ. Obtained GWPZ map can be utilized effectively for planning of sustainable agriculture. This analysis demonstrates the potential applicability of the methodology for a general coastal groundwater basin. 相似文献
Field studies were conducted during two consecutive wet seasons in flooded rice (Oryza sativa L.) to determine the effect of green manure on urea utilization in a rice-fallow-rice cropping sequence. Replicated plots were fertilized with 60 to 120 kg of urea N ha–1 in three split applications (50, 25 and 25%) with or without incorporation of dhaincha (Sesbania aculeata L.) (100 kg N ha–1). During the first crop only 31 to 44% of the urea added was used by the rice. Incorporatingin situ grown dhaincha (GM) into the soil at transplanting had little effect on urea utilization. Forty-four to 54% of the N added was not recovered in the soil, rice crop, or as nitrate leachate during the first cropping season. Incorporation of GM had no effect on fertilizer N recovery. Only about 2% of the urea N added to the first rice crop was taken up by the second rice crop and, as in the first crop, the GM had little effect on residual N, either in amount or utilization. 相似文献
Homologues long‐chain chrysin derivatives (LCD, Cn: 8–18) were synthesized and incorporated into nanostructured lipid carriers (NLC) with the aim to treat human neuroblastoma. Mutual miscibility and attractive interactions among the NLC components, namely tripalmitin (TP), cetyl palmitate (CP), oleic acid (OA), and the chrysin (CHR) derivatives (LCD) at the air–water interface were assessed by the Langmuir monolayer approach. Optimum combination for the NLC formulations was found to be 2:2:1 (M/M/M) for TP/CP/OA, respectively. NLC formulations, both in the absence and presence of LCD, were characterized by combined dynamic light scattering, electron microscopy, atomic force microscopy, and differential scanning calorimetry. The size and zeta potential of the NLC formulations were found in the range 200–350 nm and ?12 to ?18 mV, respectively. Encapsulation efficiency and release kinetics of CHR and LCD when loaded into NLC were also evaluated. LCD exhibited maximum incorporation, drug‐loading capacity, and sustained release because of its enhanced hydrophobicity. Superior incorporation efficiency and sustained‐release profile of LCD were able to enhance their anticancer activity against human neuroblastoma cell lines, compared to CHR, making them promising agents in combating cancer. 相似文献
In this paper, we propose a simple repetitive learning variable structure control (RLVSC) scheme to reduce periodic speed ripples in a permanent magnet synchronous motor (PMSM). These speed ripples are induced by parasitic torque pulsations that vary periodically with rotor position. The conventional PI speed controller is able to reduce speed ripples to a certain extent but not sufficient enough for many high performance applications. During steady state, the RLVSC generates a reference compensation current that together with the outer loop PI speed controller is used to minimize the speed ripples. Being a plug-in module, the proposed RLVSC controller can be easily integrated to any of the existing PMSM drive systems. Experimental evaluation of the proposed scheme is carried out on a DSP-controlled PMSM drive platform. Test results obtained demonstrate the effectiveness of the proposed control scheme in reducing speed ripples by a factor of approximately 3 under various operating conditions. 相似文献
An enhancement mode p-GaN gate AlGaN/GaN HEMT is proposed and a physics based virtual source charge model with Landauer approach for electron transport has been developed using Verilog-A and simulated using Cadence Spectre, in order to predict device characteristics such as threshold voltage, drain current and gate capacitance. The drain current model incorporates important physical effects such as velocity saturation, short channel effects like DIBL (drain induced barrier lowering), channel length modulation (CLM), and mobility degradation due to self-heating. The predicted Id-Vds, Id-Vgs, and C-V characteristics show an excellent agreement with the experimental data for both drain current and capacitance which validate the model. The developed model was then utilized to design and simulate a single-pole single-throw (SPST) RF switch. 相似文献
Eutectoid steels, which are traditionally used as rails in railway systems, are prone to corrosion, especially in coastal environments. In order to minimize this problem, four new rail steel compositions, with different combinations of microalloying elements Cu, Cr, Ni and Si, were designed and processed as per the thermomechanical schedule for normal rail steel processing in industry. Corrosion behavior of the rail steels were studied by weight loss measurement after immersion test and Tafel polarization in freely aerated 3.5 % NaCl. The rust obtained after immersion test were characterized by Fourier transform infrared spectroscopy (FTIR). Corrosion rate obtained weight loss measurement was similar for all the rail steels. γ-FeOOH (lepidocrocite) and δ-FeOOH were identified as the major rust phases from the FTIR spectra of the rail steels. The relative absorption intensities of these rust phases were similar for all the rail steels. Corrosion rates calculated from Tafel polarization tests were similar for all the rail steels. The corresponding free corrosion potentials were also similar for all the rail steels. The zero corrosion potential obtained from Tafel polarization of Cu-Mo, Cr-Mn, Cu-Ni, Cr-Cu-Ni and Cr-Cu-Ni-Si rail steels was more noble compared to C-Mn and Cu-Si rail steels indicating better corrosion resistance of these alloys. The importance of conducting alternate wetting and drying test has been emphasized. 相似文献