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

MODLEACH: A Variant of LEACH for WSNs

Wireless sensor networks are appearing as an emerging need for mankind. Though, Such networks are still in research phase however, they have high potential to be applied in almost every field of life. Lots of research is done and a lot more is awaiting to be standardized. In this work, cluster based routing in wireless sensor networks is studied precisely. Further, we modify one of the most prominent wireless sensor network's routing protocol "LEACH" as modified LEACH (MODLEACH) by introducing \emph{efficient cluster head replacement scheme} and \emph{dual transmitting power levels}. Our modified LEACH, in comparison with LEACH out performs it using metrics of cluster head formation, through put and network life. Afterwards, hard and soft thresholds are implemented on modified LEACH (MODLEACH) that boast the performance even more. Finally a brief performance analysis of LEACH, Modified LEACH (MODLEACH), MODLEACH with hard threshold (MODLEACHHT) and MODLEACH with soft threshold (MODLEACHST) is undertaken considering metrics of throughput, network life and cluster head replacements.Comment: IEEE 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, Franc

Comparison of spatial domain optimal trade-off maximum average correlation height (OT-MACH) filter with scale invariant feature transform (SIFT) using images with poor contrast and large illumination gradient

A spatial domain optimal trade-off Maximum Average Correlation Height (OT-MACH) filter has been previously developed and shown to have advantages over frequency domain implementations in that it can be made locally adaptive to spatial variations in the input image background clutter and normalised for local intensity changes. In this paper we compare the performance of the spatial domain (SPOT-MACH) filter to the widely applied data driven technique known as the Scale Invariant Feature Transform (SIFT). The SPOT-MACH filter is shown to provide more robust recognition performance than the SIFT technique for demanding images such as scenes in which there are large illumination gradients. The SIFT method depends on reliable local edge-based feature detection over large regions of the image plane which is compromised in some of the demanding images we examined for this work. The disadvantage of the SPOTMACH filter is its numerically intensive nature since it is template based and is implemented in the spatial domain. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Autogenous self-healing of cement with expansive minerals-I: Impact in early age crack healing

This study investigates the impact of expansive minerals, namely magnesium oxide, bentonite clay, and quicklime on the early age autogenous self-healing capacity of Portland cement (PC) paste. Individual mineral dosage in PC was studied comprehensively together with several multiple mineral combinations. The study also covers a brief state of the art on autogenous self-healing and the use of minerals. The healing performance was compared using flexural strength recovery, crack sealing, and permeability tests. Materials microstructural investigations were carried out using XRD, TGA and SEM-EDX. The hydrated and swelling products of expansive minerals have effectively contributed to the production of healing materials. Cracks in the range of 150 µm healed efficiently in a mineral containing mixes within 28 days. Self-healing recovery was triggered through the crack bridging (strength recovery), sealing (physical closer of cracks through crystallisation) and durability performance improvement.The support of Islamic Development Bank (IDB) scholarship collaborating with Cambridge Overseas Trust for the first author’s PhD research is greatly appreciated. Moreover, collaboration from the Engineering and Physical Sciences Research Council (EPSRC) for this study (Project Ref. EP/K026631/1 – “Materials for Life: Biomimetic multi-scale damage immunity for construction materials”) is also gratefully acknowledged

Stillbirth should be given greater priority on the global health agenda

Stillbirths are largely excluded from international measures of mortality and morbidity. Zeshan Qureshi and colleagues argue that stillbirth should be higher on the global health agenda

AC and DC House Wiring Efficiency Estimations Using a Fast Extensive Measurements Approach

DC-based appliances are exponentially increasing in the present market. This scenario opens the opportunity to utilize the DC electricity produced by the PV panels directly without going through the conversion stages. Due to high penetration of DC electricity sources, it is timely to utilize DC electricity directly. Several research works have been reported in the literature to experimentally test and compare AC and DC wiring options. Accurate and precise experimental measurements are vital to establish a sound theoretical basis. However, this is difficult due to cost and time constraints. Therefore, to avoid costly measurements, this paper develops a mathematical model based on measurements on selected AC and DC wiring at four voltage levels (12 V DC, 24 V DC, 48 V DC, and 230 V AC). A digital simulation calibration using DigSilent is conducted to validate the proposed mathematical model. This paper proposed to utilize the simulation calibration approach that is a cost-effective and timesaving option to perform extensive measurements accurately

A 3D multi-frequency response electrical mesh phantom for validation of the planar structure EIT system performance

Assessment and validation of the Electrical Impedance Tomography (EIT) system performance and calibration of systematic errors in the electrical field generated inside of the interrogated volume is an important requirement. System instabilities can be caused by the EIT design and must be characterized before and during the clinical trials. Evaluation of the Sussex EIT system used in the clinical study can be based on a realistic electronic phantom. We designed a mesh phantom based on the electrode configuration and mesh structures of the image reconstruction. The phantom has the capability of modelling the cellular electrical properties that are operative within a circular homogeneous medium. The design is optimized to assess the planar topology of the internal impedance distribution. The system employs the information from the electrical properties of biological tissues to evaluate the Cole-Cole dispersion data. This mesh phantom is capable of producing localized conductivity perturbations between each arbitrary channel in the electrode placement planar phantom topology by measuring all 1416 combinations that are to be used in the image reconstruction. The phantom is especially designed for the Sussex EIT system to validate system performance of measurements consisting of SNR, and modelling system accuracy

An evaluation of topical and local anesthesia in phacoemulsification

Objective: To assess the comparative efficacy of topical and local anesthesia in phacoemulsification.MATERIAL AND Methods: The medical records of 186 men and women between the ages of 45-85 years, who underwent elective cataract surgery by phacoemulsification technique, under the care of one surgeon, over a period of one year, from March 1999-March 2000 were reviewed.Results: Of 186 patients who underwent small incision, self-healing phacoemulsification cataract surgery, 124 received topical and 62 local anesthesia. The most common cataract types were nuclear sclerosis. The duration of surgery with topical anesthesia was shorter. Sutures and eye padding were more frequently applied for procedures done under local anesthesia. Uncorrected visual acuity in the first post-op week was between 20/20-20/50 for 53.6% of the cases done under topical compared to 30.9% in local anesthesia. A similar trend was noted in the visual acuity one month post operatively.CONCLUSION: The uncorrected visual acuity improves faster and the duration of surgery is shorter when topical anesthesia is used

Ground state magnetic structure of Mn3_3Ge

We have used spherical neutron polarimetry to investigate the magnetic structure of the Mn spins in the hexagonal semimetal Mn$_3$Ge, which exhibits a large intrinsic anomalous Hall effect. Our analysis of the polarimetric data finds a strong preference for a spin structure with $E_{1g}$ symmetry relative to the $D_{6h}$ point group. We show that weak ferromagnetism is an inevitable consequence of the symmetry of the observed magnetic structure, and that sixth order anisotropy is needed to select a unique ground state