A low-complexity turbo decoder architecture for energy-efficient wireless sensor networks

Turbo codes have recently been considered for energy-constrained wireless communication applications, since they facilitate a low transmission energy consumption. However, in order to reduce the overall energy consumption, Look-Up- Table-Log-BCJR (LUT-Log-BCJR) architectures having a low processing energy consumption are required. In this paper, we decompose the LUT-Log-BCJR architecture into its most fundamental Add Compare Select (ACS) operations and perform them using a novel low-complexity ACS unit. We demonstrate that our architecture employs an order of magnitude fewer gates than the most recent LUT-Log-BCJR architectures, facilitating a 71% energy consumption reduction. Compared to state-of- the-art Maximum Logarithmic Bahl-Cocke-Jelinek-Raviv (Max- Log-BCJR) implementations, our approach facilitates a 10% reduction in the overall energy consumption at ranges above 58 m

Combined Time and Information Redundancy for SEU-Tolerance in Energy-Efficient Real-Time Systems

Recently the trade-off between energy consumption and fault-tolerance in real-time systems has been highlighted. These works have focused on dynamic voltage scaling (DVS) to reduce dynamic energy dissipation and on time redundancy to achieve transient-fault tolerance. While the time redundancy technique exploits the available slack time to increase the fault-tolerance by performing recovery executions, DVS exploits slack time to save energy. Therefore we believe there is a resource conflict between the time-redundancy technique and DVS. The first aim of this paper is to propose the usage of information redundancy to solve this problem. We demonstrate through analytical and experimental studies that it is possible to achieve both higher transient fault-tolerance (tolerance to single event upsets (SEU)) and less energy using a combination of information and time redundancy when compared with using time redundancy alone. The second aim of this paper is to analyze the interplay of transient-fault tolerance (SEU-tolerance) and adaptive body biasing (ABB) used to reduce static leakage energy, which has not been addressed in previous studies. We show that the same technique (i.e. the combination of time and information redundancy) is applicable to ABB-enabled systems and provides more advantages than time redundancy alone

Synthesis and characterization of silver nanoarticles from extract of Eucalyptus citriodora

The primary motivation for the study to develop simple eco-friendly green synthesis of silver nanoparticles using leaf extract of Eucalyptus citriodora as reducing and capping agent. The green synthesis process was quite fast and silver nanoparticles were formed within 0.5 h. The synthesis of the particles was observed by UV-visible spectroscopy by noting increase in absorbance. Characterization of the particles was carried out by X-ray diffraction, FTIR and electron microscopy. The developed nanoparticles demonstrated that E. citriodora is good source of reducing agents. UV-visible absorption spectra of the reaction medium containing silver nanoparticles showed maximum absorbance at 460 nm. FTIR analysis confirmed reduction of Ag+ to Ag0 atom in silver nanoparticles. The XRD pattern revealed the crystalline structure of silver nanoparticles. The SEM analysis showed the size and shape of the nanoparticles. The method being green, fast, easy and cost effective can be recommended for large scale production of AgNPs for their use in food, medicine and materials

Longitudinal and transverse fermion-boson vertex in QED at finite temperature in the HTL approximation

We evaluate the fermion-photon vertex in QED at the one loop level in Hard Thermal Loop approximation and write it in covariant form. The complete vertex can be expanded in terms of 32 basis vectors. As is well known, the fermion-photon vertex and the fermion propagator are related through a Ward-Takahashi Identity (WTI). This relation splits the vertex into two parts: longitudinal (Gamma_L) and transverse (Gamma_T). Gamma_L is fixed by the WTI. The description of the longitudinal part consumes 8 of the basis vectors. The remaining piece Gamma_T is then written in terms of 24 spin amplitudes. Extending the work of Ball and Chiu and Kizilersu et. al., we propose a set of basis vectors T^mu_i(P_1,P_2) at finite temperature such that each of these is transverse to the photon four-momentum and also satisfies T^mu_i(P,P)=0, in accordance with the Ward Identity, with their corresponding coefficients being free of kinematic singularities. This basis reduces to the form proposed by Kizilersu et. al. at zero temperature. We also evaluate explicitly the coefficient of each of these vectors at the above-mentioned level of approximation.Comment: 13 pages, uses RevTe

Mid-infrared intersubband absorption from p-Ge quantum wells grown on Si substrates

Mid-infrared intersubband absorption from p-Ge quantum wells with Si0.5Ge0.5 barriers grown on a Si substrate is demonstrated from 6 to 9 μm wavelength at room temperature and can be tuned by adjusting the quantum well thickness. Fourier transform infra-red transmission and photoluminescence measurements demonstrate clear absorption peaks corresponding to intersubband transitions among confined hole states. The work indicates an approach that will allow quantum well intersubband photodetectors to be realized on Si substrates in the important atmospheric transmission window of 8–13 μm

Mid-Infrared Intersubband Absorption from P-Ge Quantum Wells on Si

Mid-infrared intersubband absorption from p-Ge quantum wells with Si0.5Ge0.5 barriers grown on a Si substrate is demonstrated from 6 to 9 μm wavelength at room temperature and can be tuned by adjusting the quantum well thickness. Fourier transform infra-red spectroscopy measurements demonstrate clear absorption peaks corresponding to intersubband transitions among confined hole states. The work indicates an approach that will allow quantum well intersubband photodetectors to be realized on Si substrates in the important atmospheric transmission window of 8–13 μm

Hematological Indices of Sickle Cell Anaemia Patients with Pulmonary Tuberculosis in Northern Nigeria.

Nigeria has the fourth highest prevalence of TB and the highest prevalence of Sickle cell anaemia (SCA) in the world. SCA patients have impaired immunity and are vulnerable to TB. Hence, we studied the haematological indices of SCA patients with TB in Nigeria. A total of 23 SCA patients with TB were studied in parallel with equal number of age and sex matched SCA patients without TB. SCA patients with TB had significantly lower haematocrit, higher level of circulating sickle cells (CSCs) and similar level of reticulocyte count in comparison to patients without TB. SCA patients with TB had significantly higher mean WBC count associated with higher frequency of neutrophilia in comparison to those without TB. Monocytosis and eosinopenia were exclusively found in SCA patients with TB at frequencies of 52% and 65% respectively. Lymphocyte and basophil counts were normal in all patients with and without TB. Mean platelet counts were high in both patient groups but the frequency of thrombocytosis was significantly higher in patients with TB. SCA patients with TB had significantly higher mean ESR than their counterparts without the infection. The findings of this study revealed that TB in SCA patients was associated with rising level of CSCs, falling level of haematocrit, sub-optimal reticulocytosis, neutrophilia, monocytosis, thrombocytosis, eosinopenia and rising level of ESR. Hence, SCA patients presenting with these haematological indices should be investigated for TB

Transcranial direct current stimulation and stroke recovery: opportunities and challenges

Transcranial direct current stimulation (tDCS) is one type of neuromodulation, which is an emerging technology that holds promise for the future studies on therapeutic and diagnosis applications in treatment of neurological and psychiatric diseases. However, there is a serious question among developing countries with limited financial and human resources, about the potential returns of an investment in this field and regarding the best time to transfer this technology from controlled experimental settings to health systems in the public and private sectors. This article reviews the tDCS as tools of neuromodulation for stroke and discusses the opportunities and challenges available for clinicians and researchers interested in advancing neuromodulation therapy. The aim of this review is to highlight the usefulness of tDCS and to generate an interest that will lead to appropriate studies that assess the true clinical value of tDCS for brain diseases in developing countries. Methods: Literature review was done on PubMed from 2016 on neuromodulation in under-developed countries (UDCs) by non-invasive brain stimulation methods, using the key words “stroke”, “rehabilitation”, and “tDCS”. Results: We first identified articles and websites, of which were further selected for extensive analysis mainly based on clinical relevance, study quality and reliability, and date of publication. Conclusion: Despite the promising results obtained with tDCS in basic and clinical neuroscience, further progress has been impeded by a lack of clarity to use in mostly UDCs