Electromagnetic band gap coupled tri-notched miniaturized ultra-wideband antenna loaded with slot and parasitic strip

An electromagnetic band gap (EBG) coupled miniaturized tri-notched printed ultra-wideband (UWB) monopole microstrip antenna having dimensions of 22 mm × 26 mm × 1.6 mm loaded with a slot in radiating patch and a parasitic strip in the ground plane has been presented. The proposed structure incorporates a square-shaped metallic radiating patch with a square EBG structure adjacent to the microstrip feed line, a U-shaped meandered slot over the radiating element, and a U-shaped parasitic resonator at the ground plane beneath the radiating element, to reject the C-band satellite downlink (3.7 to 4.2 GHz), WLAN frequency band (5.15 to 5.85 GHz), and X-band satellite downlink (7.25 to 7.75 GHz) frequency bands, respectively. The designed antenna operates in the frequency range from 3 to 11.1 GHz, with an impedance bandwidth of 8.1 GHz and a percentage bandwidth of 114%. Modification steps incorporating into the reference antenna to achieve the desired design objectives have been discussed, along with parametric studies. The proposed design has been simulated using Ansys HFSS, and measurement has been taken using standard measurement technique and compared with the simulated results.     

2D Covalent Organic Frameworks for Biomedical Applications

Covalent organic frameworks (COFs) are an emerging class of organic crystalline polymers with well‐defined molecular geometry and tunable porosity. COFs are formed via reversible condensation of lightweight molecular building blocks, which dictate its geometry in two or three dimensions. Among COFs, 2D COFs have garnered special attention due to their unique structure composed of two‐dimensionally extended organic sheets stacked in layers generating periodic columnar π‐arrays, functional pore space, and their ease of synthesis. These unique features in combination with their low density, high crystallinity, large surface area, and biodegradability have made them an excellent candidate for a plethora of applications ranging from energy to biomedical sciences. In this article, the evolution of 2D COFs is briefly discussed in terms of different types of chemical linkages, synthetic strategies of bulk and nanoscale 2D COFs, and their tunability from a biomedical perspective. Next, the biomedical applications of 2D COFs specifically for drug delivery, phototherapy, biosensing, bioimaging, biocatalysis, and antibacterial activity are summarized. In addition, current challenges and emerging approaches in designing 2D COFs for advanced biomedical applications are discussed.     

Golden-Free Hardware Trojan Detection with High Sensitivity Under Process Noise

Malicious modification of integrated circuits in untrusted design house or foundry has emerged as a major security threat. Such modifications, popularly referred to as Hardware Trojans, are difficult to detect during manufacturing test. Sequential hardware Trojans, usually triggered by a sequence of rare events, represent a common and deadly form of Trojans that can be extremely hard to detect using logic testing approaches. Side-channel analysis has emerged as an effective approach for detection of hardware Trojans. However, existing side-channel approaches suffer from increasing process variations, which largely reduce the detection sensitivity and sets a lower limit of the sizes of Trojans detectable. In this paper, we present TeSR, a Temporal Self-Referencing approach that compares the current signature of a chip at two different time windows to isolate the Trojan effect. Since it uses a chip as a reference to itself, the method completely eliminates the effect of process noise and other design marginalities (e.g. capacitive coupling), thus providing high detection sensitivity for Trojans of varying size. Furthermore, unlike most of the existing approaches, TeSR does not require a golden reference chip instance, which may impose a major limitation. Associated test generation, test application, and signature comparison approaches aimed at maximizing Trojan detection sensitivity are also presented. Simulation results for three complex sequential designs and three representative sequential Trojan circuits demonstrate the effectiveness of the approach under large inter- and intra-die process variations. The approach is also validated with current measurement results from several Xilinx Virtex-II FPGA chips.     

Local structure studies of Ni doped ZnO/PVDF composite free-standing flexible thin films using XPS and EXAFS studies

Free-standing flexible films of Ni-ZnO/PVDF with three Ni concentrations were obtained by sol–gel technique. The as-deposited and the poled composite Ni-ZnO/PVDF films contained three different amount of Ni doping in ZnO nanocrystals as Zn_1?x Ni _x O (x?=?0.01, 0.04, and 0.09). XANES, XPS measurements have been carried out to investigate the valence states of the host and dopant ions in samples while local environments surrounding Zn and Ni sites have been critically examined using extended EXAFS and XPS measurements to throw a clear insight on the bonding environment in the Ni-ZnO/PVDF films     

Characterization of budding twigs of flower-type zinc oxide nanocrystals for the fabrication and study of nano-ZnO/p-Si heterojunction UV light photodiode

Journal of Materials Science: Materials in Electronics - In this work, we focused on the study of the structural and optical properties of chemical precipitation-derived special shape (budding...     

Performance evaluation of a low conductive growth medium (LCGM) for growth of healthy and stressed Listeria monocytogenes and other common bacterial species

The performance of a low conductive growth medium (LCGM) (conductivity of <1300 microS) was evaluated for its ability to support growth of food borne bacterial pathogens including Listeria monocytogenes and to determine the expression of the two key virulence proteins in L. monocytogenes for possible applications in an impedance-based microfluidic biochip detection platform. Growth of Listeria was monitored spectrophotometrically and the lag phase, generation time, growth rate and maximum population density were determined using the Gompertz equation. LCGM had a lag phase of 2.3 h and showed a higher cell density compared to Luria Bertini (LB) broth. Length of lag phase was highly dependent on initial inoculum concentrations. The changes in conductivity with respect to growth in the low conductive medium were monitored using a conductivity probe. L. monocytogenes growth could be detected within 2 h (0.1 mS) in LCGM and within 6 h in LB. The performance of the media was also evaluated for the recovery of Listeria cells exposed to various stresses as 42 degrees C for 1, 2 or 6 h, an osmotic stress in 10.5% NaCl, an acidic stress at pH 2, 3 or 5 and a combined stress of 10.5% NaCl, pH 5 and 1 h exposure at 42 degrees C. The recovery rate was comparable with that of Tryptic soy broth containing yeast extract (TSBYE). L. monocytogenes in LCGM supported the expression of two key virulence markers, actin polymerization protein (ActA) and internalin B (InlB), which could be detected using specific antibodies. In general LCGM also supported the growth of several other bacterial species suggesting its implication in microbial quality monitoring of products. In conclusion, LCGM is a sensitive low conductive medium that supports the growth as well as the expression of virulence markers for potential applications in sensitive detection of L. monocytogenes or other food borne pathogens in impedance-based sensor platform.     

Interval valued demand related inventory model under all units discount facility and deterioration via parametric approach

In the yard of business organization, due to a major number of competitors and uncertainty of customers’ demand, everyone faces some disturbances for smoothly running of their business. To survive in the fierce competition some modern business policies are required and accordingly the formulation of an advanced inventory model is indispensable by handling the uncertainty of customers’ demand. In this model formulation, discount facility is considered as a business policy whereas interval valued demand is proposed to tackle the uncertainty of customers’ demand. The purpose of this work is to analyze a model with interval valued parameters for deteriorating items considering two situations (with shortages and without shortage) in the discount environment. Moreover, deterioration rate is taken into account as interval valued and unit carrying cost is supposed to be a function of the length of storage time as well as interval valued purchase cost. Also, the interval valued purchase cost is assumed to be a step function (decreasing) of lot size under discount business policy. Considering without shortage and with shortages separately, using parametric approach of interval differential equations, the proposed model is formulated in two different cases. After formulating the proposed model properly, the corresponding profit functions are obtained for two different cases (without shortage and with shortages). In order to optimize the profit, various types of meta-heuristic algorithms (weighted quantum behaved particle swarm optimization and Gaussian quantum behaved particle swarm optimization) are used and then the obtained results are compared. Finally, to justify the reality of the model, numerical illustrations are presented and also post optimality analyses are performed with the changes of known parameters.