Correction to: A subthreshold low-power CMOS LC-VCO with high immunity to PVT variations

This paper presents a capacitor-free low dropout (LDO) linear regulator based on a dual loop topology. The regulator utilizes two feedback loops to satisfy the challenges of hearing aid devices, which include fast transient performance and small voltage spikes under rapid load-current changes. The proposed design works without the need of a decoupling capacitor connected at the output and operates with a 0–100 pF capacitive load. The design has been taped out in a \(0.18\,\upmu \hbox {m}\) CMOS process. The proposed regulator has a low component count, area of \(0.012\, \hbox {mm}^2\) and is suitable for system-on-chip integration. It regulates the output voltage at 0.9 V from a 1.0–1.4 V supply. The measured results for a current step load from 250 to 500 \(\upmu \hbox {A}\) with a rise and fall time of \(1.5\,\upmu \hbox {s}\) are an overshoot of 26 mV and undershoot of 26 mV with a settling time of \(3.5\,\upmu \hbox {s}\) when \({C_L}\) between 0 and 100 pF. The proposed LDO regulator consumes a quiescent current of only \(10.5\,\upmu \hbox {A}\). The design is suitable for application with a current step edge time of 1 ns while maintaining \(\Delta V_{out}\) of 64 mV.     

Voice spoofing detection based on acoustic and glottal flow features using conventional machine learning techniques

Multimedia Tools and Applications - Automatic Speaker Verification (ASV) systems are vulnerable to spoofing attacks. Most existing spoofing detection systems rely on two main points; the feature...     

Accountable privacy preserving attribute-based access control for cloud services enforced using blockchain

International Journal of Information Security - When dealing with cloud services, there are important security requirements that are highly recommended to be achieved, notably, access control....     

A subthreshold low-power CMOS LC-VCO with high immunity to PVT variations

This paper presents a current driver with a novel high voltage (HV) switch schematic for the use as a protective switch for recording circuits during the stimulation sequence in neural measurement system. The current driver can source and sink currents of amplitudes up to ±8.2 mA with a HV tolerance from 30 V up to 120 V. The proposed HV switch also tolerates the voltage difference up to 120 V between its terminals. Between stimulation sequences the driver provides the effective isolation of the stimulation electrode from ground and HV supply voltage. The inter pulse current is no more than 60 pA. The chip was fabricated with AMS HV 0.35 \(\mu\)m CMOS technology. For test purposes the complete stimulation system including the proposed chip and the external C8051F410 controller was build. For the proposed system the mismatch between the sourced and sinked current does not exceed 20 \(\mu\)A. The possibility to stimulate with frequencies up to 1 kHz is proven by measurement along with the electrode-tissue model.     

Selective catalytic reduction of NO by NH3 on Cu (II) ion-exchanged offretite prepared by different methods

The influence of the preparation method on the NO–SCR by NH₃ activity of Cu-OFF catalysts has been studied on presence of oxygen. The catalysts structure and the nature of copper species have been investigated by XRD, ²⁷Al MAS NMR, UV-visible spectroscopy and H₂-TPR. Among the examined preparation methods, the ionic exchange in aqueous solution gives the highest efficient catalyst in NO-SCR. It is shown that Cu cationic species are formed in large extent with this method despite the presence of minor amounts of small oxide clusters.     

Proposal of new eco-manufacturing feature interaction-based methodology in CAD phase

Following the environmental crises of recent decades, a turning point in the awareness of the fragility of ecosystems has been marked, i.e., environmental awareness. This has contributed to the development of various environmental laws and regulations such as the “Waste Electrical and Electronic Equipment,” the “Restriction of Hazardous Substances,” and the “Registration, Evaluation, Authorization and Restriction of Chemicals” regulations and the “Energy Using Products” Directives. Our work contributes to the development of eco-friendly product manufacturing processes. In order to estimate and optimize the environmental impacts of a product, most of the methodologies, concepts, and tools that integrate computer-aided design (CAD) and life cycle assessment systems generally exploit the feature technology at the level of each feature independently of the others, i.e., “microplanning.” The feature interaction technology (FIT) is treated only in few studies, but it is pivotal in the eco-manufacturing process. In this paper, we propose a new manufacturing-scenarios-based methodology by using FIT and a Multi-criteria Decision Support Method (MCDSM), which helps manufacturers maintain their marketplaces by producing goods in an eco-friendly way. In fact, this methodology helps designers choose from the CAD design phase the most ecological manufacturing process from possible existent scenarios in real time.     

Trypsin from zebra blenny (Salaria basilisca) viscera: Purification,characterisation and potential application as a detergent additive

An alkaline trypsin was purified from the viscera of zebra blenny (Salaria basilisca) by ammonium sulphate (40?80% saturation) precipitation, Sephadex G-100, Mono Q-Sepharose and ultrafiltration. A yield of 12% with a purification-fold of 4.2 was obtained. The trypsin had an apparent molecular weight of 27 kDa. Soybean trypsin inhibitor and phenylmethylsulfonyl fluoride showed a strong inhibitory effect on the purified trypsin. Trypsin had maximal activity at pH 9.5 and 60 °C for the hydrolysis of Nα-benzoyl-dl-arginine-p-nitroanilide (BAPNA). It was stable at low temperatures and in the pH range of 7.0?12.0. The N-terminal amino acid sequence of the first 12 amino acids of the purified protease was IVGGRECTEPSQ. S. basilisca trypsin, which showed high homology with other fish trypsins, had a charged Arg residue at position 5, where Tyr is common in marine vertebrates and mammalian trypsins. The trypsin kinetic constants, K_m and k_cat for BAPNA, were 0.6 mM and 1.38 s^?1, respectively.     

Sol–gel derived mesoporous Cr/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalysts for SCR of NO by ammonia

Catalytic performances of Cr/Al₂O₃ catalysts were investigated in Selective Catalytic Reduction (SCR) of NO by NH₃ in the presence of oxygen. Solids were prepared either by sol–gel method or by impregnation and were characterized by different techniques such as chemical analysis, N₂ physisorption, XRD, ²⁷Al MAS NMR, DRIFT, UV–Vis Diffuse Reflectance (DRS), Raman Spectroscopy and Temperature Programmed Reduction by H₂ (H₂-TPR). The physisorption of N₂ at 77 K reveals that solids are mesoporous. On the other hand, XRD shows that xerogels are amorphous but supercritical drying leads to a nanosized crystallite state. No crystalline α-Cr₂O₃ was found which indicate that metal species reside essentially on the surface of Al₂O₃ and their size measured less than 4 nm. Furthermore, ²⁷Al MAS NMR reveals that part of chromium ions occupies sites on/in Al₂O₃ in close vicinity of tetrahedral ²⁷Al. This, apparently, is not the case for aerogels. DRIFT results show that there is a consumption of hydroxyl groups of alumina after calcination. The esterification reaction between hydroxyl groups and chromium oxide during calcination leads to the formation of anchored (poly-)chromates according to DRS, Raman, and H₂-TPR results. The catalysts are active in the studied reaction by NH₃ and the activity is principally governed by preparation method and operating conditions. When compared to xerogels, aerogels are more active in NO reduction and less selective toward N₂O. Preparation method and drying mode seem to involve the predominance of active species which are essentially mono and polychromates but Cr³⁺ ions incorporated inside alumina seem to be inactive.