Statistical forecasting algorithm on circuit level gain transformation due to negative bias temperature instability for the microwave frequency spectrum

Negative Bias Temperature Instability (NBTI) is a critical reliability issue for CMOS technology, as this directly impacts the CMOS circuit performance parameters causing system failure. Moreover, NBTI behavior for radio frequency (RF) signals needs more understanding. On the device level, there has been much research on the relation between NBTI and RF. Many of those works contradict each other on the question of RF dependency with NBTI. Hence, the behavior of NBTI must be analyzed at the circuit level using a prediction technique. In this article, we analyzed the circuit level impact of NBTI for microwave frequency and developed a gain transformation technique for RF circuits in the microwave frequency range. To do this, we employed a 65 nm conventional ring oscillator as an RF block and carried out an aging simulation on it. A compatibility analysis was performed on low and high bandwidth microwave signals. The implemented statistical technique can determine the actual operable frequency range, so that the RF circuit can perform with minimal NBTI effect.     

Two-step growth of hexagonal-shaped ZnO nanowires and nanorods and their properties

Single-crystalline with perfect hexagonal-shaped ZnO nanowires and nanorods, possessing the Zn-terminated (0001) facets bounded with the six-crystallographic equivalent [0110] surfaces, have been grown on Au-coated silicon substrate via thermal evaporation method using the metallic zinc powder in presence of oxygen. The detailed structural analyses reveal that the obtained nanostructures are single-crystalline with the wurtzite hexagonal phase and are preferentially oriented in the c-axis, [0001] direction. Raman spectra exhibit a sharp and strong optical phonon E2 mode at 437 cm(-1) further confirms the good crystal quality with wurtzite hexagonal crystal structure for the deposited products. The room-temperature photoluminescence (PL) spectra, for both the structures, showed a sharp and strong UV emission with a suppressed green emission, indicating the good optical properties for the as-grown nanostructures.     

Low-temperature growth of flower-shaped UV-emitting ZnO nanostructures on steel alloy by thermal evaporation

Flower-shaped ZnO nanostructures, containing the triangular-shaped petals (sharpened tips and wider bases) have been achieved by simple thermal evaporation of high purity metallic zinc powder in the presence of oxygen at 440 degrees C on steel alloy substrate without the use of metal catalyst or additives. Detailed structural studies confirm that the obtained flower-shaped nanostructures are single crystalline and possesses a wurtzite hexagonal structure, grown along the c-axis in the [0001] direction. Raman and room temperature photoluminescence analysis substantiate a wurtzite hexagonal phase with a good crystal quality and a strong UV emission at 378 nm, respectively, indicating few or no structural defects. Additionally, a detailed possible growth mechanism has also been discussed.     

CD33 monoclonal antibody conjugated Au cluster nano-bioprobe for targeted flow-cytometric detection of acute myeloid leukaemia

Protein stabilized gold nanoclusters (Au-NCs) are biocompatible, near-infrared (NIR) emitting nanosystems having a wide range of biomedical applications. Here, we report the development of a Au-NC based targeted fluorescent nano-bioprobe for the flow-cytometric detection of acute myeloid leukaemia (AML) cells. Au-NCs with ～ 25-28 atoms showing bright red-NIR fluorescence (600-750 nm) and average size of ～ 0.8 nm were prepared by bovine serum albumin assisted reduction-cum-stabilization in aqueous phase. The protein protected clusters were conjugated with monoclonal antibody against CD33 myeloid antigen, which is overexpressed in ～ 99.2% of the primitive population of AML cells, as confirmed by immunophenotyping using flow cytometry. Au-NC-CD33 conjugates having average size of ～ 12 nm retained bright fluorescence over an extended duration of ～ a year, as the albumin protein protects Au-NCs against degradation. Nanotoxicity studies revealed excellent biocompatibility of Au-NC conjugates, as they showed no adverse effect on the cell viability and inflammatory response. Target specificity of the conjugates for detecting CD33 expressing AML cells (KG1a) in flow cytometry showed specific staining of ～ 95.4% of leukaemia cells within 1-2 h compared to a non-specific uptake of ～ 8.2% in human peripheral blood cells (PBMCs) which are CD33(low). The confocal imaging also demonstrated the targeted uptake of CD33 conjugated Au-NCs by leukaemia cells, thus confirming the flow cytometry results. This study demonstrates that novel nano-bioprobes can be developed using protein protected fluorescent nanoclusters of Au for the molecular receptor targeted flow cytometry based detection and imaging of cancer cells.     

Simulation of multiphase boost DC-DC converter with the stable control strategy

The multiphase boost DC-DC converter with stable control strategy is presented. Multi- phase boost DC-DC converter is designed for high voltage and high power applications, and could be achieved by the adjustment of voltage doubler rectifiers on the secondary side of high frequency transformers. The stable control strategy for three phase boost DC-DC converter has been utilized during simulation in this study and this strategy can be extend to N-number of phases. The stable control strategy consists of only three voltage loops, which are sufficient for appropriate and efficient operation of three phase boost DC-DC converter. With the stable control strategy, the equal power balance sharing can be obtained between input and output. The stability of control strategy has been evaluated by simulating the multiphase boost DC-DC converter for the same and mismatch turn ratios of high frequency transformers. The simulation result is good and the objective of the strategy is a- chieved.     

Highly Breathable and Stretchable Strain Sensors with Insensitive Response to Pressure and Bending

Wearable tensile strain sensors have aroused substantial attention on account of their exciting applications in rebuilding tactile inputs of human and intelligent robots. Conventional such devices, however, face the dilemma of both sensitive response to pressure and bending stimulations, and poor breathability for wearing comfort. In this paper, a breathable, pressure and bending insensitive strain sensor is reported, which presents fascinating properties including high sensitivity and remarkable linearity (gauge factor of 49.5 in strain 0–100%, R² = 99.5%), wide sensing range (up to 200%), as well as superior permeability to moisture, air, and water vapor. On the other hand, it exhibits negligible response to wide-range pressure (0–100 kPa) and bending (0–75%) inputs. This work provides a new route for achieving wearing comfortable, high-performance, and anti-jamming strain sensors.     

A stateless fairness-driven active queue management scheme for efficient and fair bandwidth allocation in congested Internet routers

Fair bandwidth sharing is important for the Internet architecture to be more accommodative of the heterogeneity. The Internet relies primarily on the end-systems to cooperatively deploy congestion control mechanisms for achieving high network utilization and some degree of fairness among flows. However, the cooperative behavior may be abandoned by some end-systems that act selfishly to be more competitive through bandwidth abuse. The result can be severe unfairness and even congestion collapse. Fairness-driven active queue management, thus, becomes essential for allocating the shared bottleneck bandwidth fairly among competing flows. This paper proposes a novel stateless active queue management algorithm, termed CHOKeH, to enforce fairness in bottleneck routers. CHOKeH splits the queue into dynamic regions at each packet arrival and treats each region differently for performing matched-drops using a dynamically updated drawing factor, which is based on the level of queue occupancy and the buffer size. In this way, CHOKeH can effectively identify and restrict unfair flows from dominating the bandwidth by discarding more packets from these flows. The performance of CHOKeH is studied through extensive simulations. The results demonstrate that CHOKeH is well suited for fair bandwidth allocation even in the presence of multiple unresponsive flows and across a wider range of buffer sizes. The results also show the ability of CHOKeH to provide inter-protocol and intra-protocols fairness and protection for short-lived flows. With a low per-packet-processing complexity, CHOKeH is amenable to implementation in core routers to offer an effective incentive structure for end-systems to self-impose some form of congestion control.     

Higher order mode excitation for high gain microstrip patch antenna

Higher order mode excitation in the microstrip patch has been achieved to alleviate the low gain problem associated with this particular class of antennas. This higher order mode excitation is achieved by geometric modification of the radiating patch. The designed antenna structure is simple in nature, provides easy fabrication and manufacturing while exhibiting high gain characteristic. The proposed antenna has a measured gain of 10.21 dBi at the operating frequency of 16 GHz. The half power beam width is approximately 36° and 34° in the H- and E- planes respectively. The antenna can be used in the different applications related to the Ku band.