A collision-free formation reconfiguration control approach for Unmanned Aerial Vehicles

Formation flying of Unmanned Aerial Vehicles (UAVs) has gained a lot of interest due to its many potential advantages. Flying in formation allows wider sensing coverage area and in effect, this leads to improved surveillance and enhanced situational awareness. Also flying in formation eases coordination and data fusion. This paper presents the control architecture for fixed-wing UAV reconfiguration control using a novel combination of known techniques. The current premise is for the UAVs to assume their final target states within a specified time interval while avoiding collisions with one another or with an obstacle during the process. Some simulations are performed to assess the performance of the reconfiguration control scheme. The effects of the control parameters on the reconfiguration trajectories are also examined.     

Protein-templated gold nanoclusters: size dependent inversion of fluorescence emission in the presence of molecular oxygen

Gold nanoclusters are promising candidates as biological markers without having toxic effects like fluorescent quantum dots. Herein, bovine serum albumin (BSA) protein stabilized gold nanoclusters of two different sizes emitting at 410 and 645 nm have been synthesized. These nanoclusters have been shown to interact with molecular oxygen differentially. Spectroscopic and chemical evidences show that dioxygen molecule gets adsorbed at two different orientations on the nanoclusters. The orientation motifs have been hypothesized to be superoxo and peroxo types on the smaller and the larger gold nanoclusters, respectively. Due to the difference in attachments, the oxygen molecule shows opposite changes in fluorescence intensity for the nanoclusters. The fluorescence intensity of the blue emitting nanocluster shows a profuse enhancement whereas the red emitting species shows quenching of emission. Superoxo type adsorption of the oxygen molecule on the blue emitting gold nanoclusters induce formation of singlet oxygen that in turn enhances the fluorescence intensity of the species. This could be verified by oxidation of diaminobenzidine (DAB) by singlet oxygen. Enhancement in fluorescence intensity of the blue emitting gold nanoclusters with an increase in concentration of molecular oxygen may enable them to be good candidates in bioimaging and detection.     

软件无线电：总体设计思路和数字硬件选择探讨

This paper reviews the requirements for Software Defined Radio (SDR) systems for high-speed wireless applications and compares how well the different technology choices available- from ASICs, FPGAs to digital signal processors (DSPs) and general purpose processors (GPPs) - meet them.     

Developing Multimodal Adaptation Algorithm for Mobility Impaired Users by Evaluating Their Hand Strength

Recent research on interactive electronic systems like computer, digital TV, smartphones can improve the quality of life of many disabled and elderly people by helping them to engage more fully to the world. Previously, a simulator was developed that reflects the effect of impairment on interaction with electronic devices and thus helps designers in developing accessible systems. In this article, the scope of the simulator has been extended to multiple pointing devices. The way that hand strength affects pointing performance of people with and without mobility impairment in graphical user interfaces was investigated for four different input modalities, and a set of linear equations to predict pointing time and average number of submovements for different devices was developed. These models were used to develop an adaptation algorithm to facilitate pointing in electronic interfaces by users with motor impairment using different pointing devices. The algorithm attracts a pointer when it is near a target and thus helps to reduce random movement during homing and clicking. The algorithm was optimized using the simulator and then tested on a real-life application with multiple distractors involving three different pointing devices. The algorithm significantly reduces pointing time for different input modalities.     

Effect of temperature on zeta potential of functionalized gold nanorod

Nanorod immersed in electrolyte solution finds many applications in different fields encompassing biotechnology, drug delivery, micro-/nanofabrication, etc. In this article, a comprehensive theoretical model has been developed and solved numerically to study the effect of nanorod temperature on its potential distribution for different salt concentrations and solution pH. The study considers surface properties of nanorod functionalized with 11-MUA at higher solution temperatures in both the presence and absence of temperature gradient to analyze contribution of thermodiffusion (in the presence of temperature gradient) and different solution properties like ionic mobility and solution permittivity (in the absence of temperature gradient). Effect of solution temperature on nanorod zeta potential in the absence of temperature gradient has been shown through numerical study along with analytical verification. Present results show that zeta potential of nanorod functionalized with 11-MUA is negative, and with increasing nanorod temperature its zeta potential value increases. In the presence of thermodiffusion, increment in zeta potential value strongly depends on solution pH, whereas in the absence of temperature gradient increment in nanorod zeta potential value solely depends on solution permittivity and absolute solution temperature.     

Enhanced efficacy of clindamycin hydrochloride encapsulated in PLA/PLGA based nanoparticle system for oral delivery

Clindamycin hydrochloride (CLH) is a clinically important oral antibiotic with wide spectrum of antimicrobial activity that includes gram‐positive aerobes (staphylococci, streptococci etc.), most anaerobic bacteria, Chlamydia and certain protozoa. The current study was focused to develop a stabilised clindamycin encapsulated poly lactic acid (PLA)/poly (D,L‐lactide‐co‐glycolide) (PLGA) nano‐formulation with better drug bioavailability at molecular level. Various nanoparticle (NPs) formulations of PLA and PLGA loaded with CLH were prepared by solvent evaporation method varying drug: polymer concentration (1:20, 1:10 and 1:5) and characterised (size, encapsulation efficiency, drug loading, scanning electron microscope, differential scanning calorimetry [DSC] and Fourier transform infrared [FTIR] studies). The ratio 1:10 was found to be optimal for a monodispersed and stable nano formulation for both the polymers. NP formulations demonstrated a significant controlled release profile extended up to 144 h (both CLH‐PLA and CLH‐PLGA). The thermal behaviour (DSC) studies confirmed the molecular dispersion of the drug within the system. The FTIR studies revealed the intactness as well as unaltered structure of drug. The CLH‐PLA NPs showed enhanced antimicrobial activity against two pathogenic bacteria Streptococcus faecalis and Bacillus cereus. The results notably suggest that encapsulation of CLH into PLA/PLGA significantly increases the bioavailability of the drug and due to this enhanced drug activity; it can be widely applied for number of therapies.Inspec keywords: drug delivery systems, biomedical materials, antibacterial activity, nanoparticles, nanomedicine, microorganisms, polymers, nanofabrication, differential scanning calorimetry, encapsulation, drugs, scanning electron microscopy, Fourier transform infrared spectraOther keywords: Streptococcus faecalis, Bacillus cereus, DSC, stable nanoformulation, monodispersed nanoformulation, pathogenic bacteria, FTIR spectra, molecular dispersion, thermal behaviour, controlled release profile, Fourier transform infrared spectra, differential scanning calorimetry, scanning electron microscopy, drug loading, encapsulation efficiency, polymer concentration, solvent evaporation method, molecular level, drug bioavailability, stabilised clindamycin encapsulated poly lactic acid‐poly (D,L‐lactide‐co‐glycolide) nanoformulation, protozoa, Chlamydia, anaerobic bacteria, gram‐positive aerobes, antimicrobial activity, oral antibiotics, oral delivery, PLA‐PLGA based nanoparticle system, clindamycin hydrochloride     

Smart dual battery management system for expanding lifespan of wireless sensor node

Wireless sensor nodes have huge energy demand for their operations; they are deployed in remote locations for various applications like weather, industrial, satellite, construction, banking, and medical. Sensor nodes require continuous or uninterrupted power supply during their life cycles. When the available renewable power sources are not sufficient to run the system, the batteries are required to deliver a continuous and uninterrupted power supply. The main focus of proposed model is to design and develop a smart dual battery management system along with a hybrid energy harvesting model that can provide reliable and efficient power support to the sensor node. The problem under consideration also focuses on reducing the state of health degradation of batteries by applying a smart battery charging methodology using an ANFIS (adaptive neuro-fuzzy inference system) controller. The proposed power management system ensures and meets the expected objectives such as switching of power sources, smart battery charging methodology (constant current and constant voltage [CC-CV]), and dual battery power support using ANFIS controller. The result was obtained through the simulation and hardware prototype of the proposed system work flawlessly to meet the desired objective with partial charging and discharging of batteries for the prevention of battery degradation and also enhance the lifespan of the batteries.     

Solution-processable zinc oxide for the polymer solar cell based on P3HT:PCBM

The device performance of polymer solar cells with zinc oxide (ZnO) nanoparticles inserted as an electron injection layer between the poly(3-hexylthiopene) (P3HT):phenyl-C60-butyric acid methyl ester (PCBM) active layer and the Al electrode was studied. The polymer solar cell consists of molybdenum-oxide (MoO3) as a hole injection layer, P3HT:PCBM bulk heterojunction as an active layer, and ZnO NPs as an electron injection layer. The ZnO layer was formed from a precursor solution on the top part of the P3HT:PCBM film (1:0.8 weight ratio) via sol-gel spin-coating, and was annealed at a low temperature (150 degrees C). The crystallinity, the atomic ratio of Zn and O, the absorption spectra, and the surface morphology of the ZnO thin films were studied. The device with a ZnO layer showed 9-11% higher J(SC) and 8-9% higher PCE compared to the devices without a ZnO layer. These improved device properties are attributed to the efficient electron extraction and the decreased reflectivity owing to the use of a ZnO layer.     

Earthquake vibration control of structures using hybrid mass liquid damper

A tuned liquid damper (TLD) is a passive vibration control device consisting of a rigid tank filled with water that relies on the sloshing of water inside it to dissipate energy. In a standard TLD configuration the TLD is connected rigidly to the top of the building structure. Earlier research has shown that the TLD is more effective when its base acceleration amplitude is larger, as it dissipates more energy through increased sloshing. This characteristic has been utilized to design this alternate TLD configuration. In this alternate TLD configuration, the TLD is rigidly attached to a secondary mass that is attached to the primary structure through a spring system. This alternate configuration is, thus, defined as a hybrid mass liquid damper (HMLD). For particular values of the secondary spring’s flexibility, the motion of the secondary structure is in phase with that of the primary structure and the TLD base is subjected to a large amplitude acceleration that increases its effectiveness. It should be noted that when the secondary spring is rigid, the alternate and standard TLD configurations are identical for very small values of the secondary mass. It is seen that, for a given structure with HMLD there exists an optimum value of the secondary spring’s stiffness for which the HMLD effectiveness is maximum. An optimally designed HMLD configuration is shown to be more effective as a control device than the standard TLD configuration for both harmonic and broad-band earthquake motions.