537 research outputs found
Chemical functionalisation of 2D materials via batch and continuous hydrothermal flow synthesis
2D materials are single or few layered materials consisting of one or several elements with a thickness of a few nanometers. Their unique, tunable physical and chemical properties including ease of chemical functionalization makes this class of materials useful in a variety of technological applications. The feasibility of 2D materials strongly depends on better synthetic approaches to improve properties, increase performance and durability and reduce costs. As such, in the synthesis of nanomaterials, hydrothermal processes are widely adopted through a precursor-product synthesis route. This method includes batch or continuous flow systems, both employing water at elevated temperatures (above boiling point) and pressures to fine tune the physical, chemical, optical and electronic properties of the nanomaterial. Both techniques yield particles with different morphology, size and surface area due to different mechanisms of particle formation. In this review, we present batch and continuous hydrothermal synthesis of a selection of 2D derivatives (graphene, MXene and molybdenum disulphide), their chemical functionalisation as an advantageous approach in exploring properties of these materials as well as the benefits and challenges of employing these processes, and an outlook for further research
The Biological Effect of a Class of Alternating Magnetic Field on Life Field Using Distilled Water as Test Materials
This study investigated the biological effect of a class of alternating magnetic field on life field using distilled water as test materials. Extremely low frequency magnetic field (ELF - MF) was carried out using a 50Hz AC power as the source, and a self made copper wire solenoid (magnetic chamber) inside which the sample was placed. A variable transformer was used to vary the current in the magnetic chamber to achieve different field intensities. The results indicate that magnetic field affects the rate of solubility of salts in water as well as an alteration in its pH. This study supports initial reports that extremely low frequency magnetic field alters the physiochemical properties of water. Keywords: magnetic field, life field, distilled water, biological effec
An Empirical Analysis of cluster-based routing protocols in wireless sensor network
Wireless Sensor Networks (WSNs) are utilized for condition monitoring, developing the board, following animals or goods, social protection, transportation, and house frameworks. WSNs are revolutionizing research. A WSN includes a large number of sensor nodes, or bits, in the application. Bits outfitted with the application\u27s sensors acquire nature data and send it to at least one sink center (in like manner called base stations). This article simulates energy-efficient network initialization strategies using simulation models. First, an overview of network initiation and exploration procedures in wireless ad-hoc networks is provided. The clustering-based routing strategy was selected since it\u27s best for ad-hoc sensor networks. The clustering-based routing techniques used for this study are described below. LEACH, SEP, and Z-SEP are used. MATLAB was used to implement and simulate all routing protocols. All protocols were simulated with various parameters like Number of CHs, Number of Alive Nodes, Number of Dead Nodes, Number of packets to BS, and circumstances to show their functioning and to determine their behavior in different sensor networks
Facial Image Verification and Quality Assessment System -FaceIVQA
Although several techniques have been proposed for predicting biometric system performance using quality values, many of the research works were based on no-reference assessment technique using a single quality attribute measured directly from the data. These techniques have proved to be inappropriate for facial verification scenarios and inefficient because no single quality attribute can sufficient measure the quality of a facial image. In this research work, a facial image verification and quality assessment framework (FaceIVQA) was developed. Different algorithms and methods were implemented in FaceIVQA to extract the faceness, pose, illumination, contrast and similarity quality attributes using an objective full-reference image quality assessment approach. Structured image verification experiments were conducted on the surveillance camera (SCface) database to collect individual quality scores and algorithm matching scores from FaceIVQA using three recognition algorithms namely principal component analysis (PCA), linear discriminant analysis (LDA) and a commercial recognition SDK. FaceIVQA produced accurate and consistent facial image assessment data. The Result shows that it accurately assigns quality scores to probe image samples. The resulting quality score can be assigned to images captured for enrolment or recognition and can be used as an input to quality-driven biometric fusion systems.DOI:http://dx.doi.org/10.11591/ijece.v3i6.503
Exploitation of juveniles of the spinycheek grouper, Epinephelus diacanthus by multiday trawlers along Dakshina Kannada coast
The juveniles in the size range 9-24 cm are in
sizeable quantities during October - May at
Mangalore and Malpe landing centres of Dakshina
Kannada coast. The present study is undertaken
to highlight the magnitude of the exploitation of
the juveniles of the Spinycheek grouper.
Epinephelus diacanthus by trawlers along the
Dakshina Kannada coast and its impact on the
stock with a brief description on its biology. This
species is known to grow to a large size and
supports a fishery of some magnitude in other
parts of the Indian coast. The results presented here are based on the data collected on the landing of the species at Mangalore and Malpe during 1988/'89 - 1993-'9
Globalization: Its Effects
A global culture is now increasingly emerging. The process of globalization is facilitated by technology. This technology comes from but one place – education. The primary way to accept (or fight it) globalization is through knowledge. Education is the main way to facilitate interaction and increase the quality of life for people everywhere
Effect of different levels of urea treated Gamba hay on growth performance of Yankasa rams
Twenty four (24) Yankasa yearling rams were used to determine the effect of feeding high levels of urea treated gamba hay (Andropogon gayanus). The rams aged 15 – 18 months with an average weight of 22 .45kg were randomly allocated to one of four dietary groups, rams in group A served as control and were offered untreated gamba hay at 2.5% of their body weight while rams in groups 2, 3 and 4 where offered 5%, 6% and 7% urea treated gamba hay respectively at 2.5% of their body weight for 90 days. All rams had equal access to water, salt lick blocks and concentrate fed at 2.0% of their body weight. Data was collected daily on feed intake, while live body weight changes and body condition score were measured weekly. Dry matter composition of the gamba hay offered declined as the level of urea treatment increased, the crude protein content of the diets also increased as the level of urea treatment increased. However the values of NDF and ADF declined as the level of urea treatment increased. Rams fed 6% and 7% treated gamba hay had significantly the highest total dry matter intake while rams fed untreated gamba hay had significantly (P<0.05) the lowest weight gain. There was no significant (P>0.05) difference in the weight gains of rams fed 6% and those fed 7% urea treated gamba hay and the rams in both groups had significantly (P<0.05) the highest weight gains. Rams fed the 6% urea treated gamba hay had the best FCR. It can be concluded that 6% &7% urea treated gamba gave similar performance but 6% had the better feed conversion ratio and is more cost effective.Key words: Urea treated gamba hay, cost effectivenes
'Marinefish-famine'(?) In Karnataka with particular reference to Udupi district during 1998-'99
'Marinefish-famine' is an issue often raised by the fishermen of Karnataka over the past
several years whenever, they are affected monetarily and there is a failure of major fisheries of
the region like mackerel and oil sardine and the high-value resources like cuttlefishes,
squids and prawnsThe production of 1,64,710 t in 1998 is less by 12.3%(23,048 t) compared to 1997 but, higher than the average production of 1.59,567 t for 1993-'97. Therefore, this marginal decrease in production in 1998 cannot be considered as anyfishfamine condition in the marine fishery sectorof the state during 1998. As far as the fishery situation during 1998-99
in the Udupi district is concerned, the study on the fish landing at the largest landing centre
of the district i.e., Malpe Fisheries Harbour shows that the production during 1998-'99 was
normal compared to the past several years but, when compared to the previous year (which was
one of the two most productive years since the commssioning of the MFH in 1986-'87 with a
record landing of 50,558 t), the landing declined by 31.4% (15,897 t). Short-term, long-term and cyclic fluctuations in marine fish landings are common features and are governed by a complex of biotic and abiotic factors and the exact causes for these variations are largely unknown. Therefore, the decrease of 12.8 and 31.4% in the marine fish landings of the state and Udupi district with reference to Malpe Fisheries Harbour respectively during 1998-'99 can be treated as
one such short-term fluctuations and hence, the year cannot be considered as fish famin
The efficacy of intravitreal antivascular endothelial growth factor as primary treatment of retinopathy of prematurity: Experience from a tertiary hospital
Background. Retinopathy of prematurity (ROP) is a vasoproliferative disease affecting premature babies and a major cause of blindness in childhood. Appropriate screening and treatment can prevent blindness.Objective. To report on the efficacy of using antivascular endothelial growth factor (bevacizumab) as first-line therapy in ROP.Methods. This was a retrospective analysis of patients with ROP treated at St John Eye Hospital, Johannesburg, South Africa, over a 3-year period. Outcome measures were the clinical response to intravitreal bevacizumab (IVB) as well as the economic impact of IVB therapy.Results. Twenty-three patients were treated for active ROP or type 1 disease, in 44 eyes. Two patients required treatment in one eye only. The mean birth weight of these patients was 1 074 g (range 810 - 1 480). Response to treatment outcome was available for 22 patients (43 eyes). The mean follow-up period was 9 months (range 1 - 18). Forty-one eyes (95.3%) showed complete regression or non-progression of the disease. Two eyes (one eye each in two patients) progressed to advanced disease. There were no short-term adverse events. A cost-effective model showed that IVB treatment was much more economical than laser therapy.Conclusion. IVB is a safe and effective first-line treatment for ROP and should be considered in resource-limited centres
Palynomorphs Content and Paleodepositional Environments of Mamu Formation in Okpekpe-1, Imiegba-1 and Imiegba-2, Benin Flank of Anambra Basin, Nigeria
Twenty surface samples were taken from road cuttings along Okpekpe and Imiegba areas located in Benin Flank of Anambra Basin, Nigeria with an aim to establish the biozones, age and paleodepositional environments of the Mamu Formation. Using palynological laboratory standard procedures, the shale surface samples collected from the Mamu Formation in the study area were prepared and analyzed. The recovered marker pollens, spores and dinoflagellate cysts from the study area are Milforadia jardinei, Milforadia sp., Longapertites marginatus, Longapertites sp., Retidiporites sp., Monocolpites marginatus,Cyathidites minor, Cyathidites spp., Cingulatisporites ornatus, Distaverrusporites simplex, Laevigatosporites spp., Foveotriletes margaritae, Subtilisphaera sp., Andalusiella sp., Paleocystodinium australinium and microforaminiferal wall linings. Four biozones were erected for the shale intervals in the study area, namely: Longapertites sp., Monocolpites marginatus, Cyathidites minor, and Paleocystodinium australinium biozone, respectively, dated to Upper Maastrichtian to Early Paleocene age, which are lateral equivalents to Spinizonocolpites baculatus biozone of the Upper Benue Trough. The presence of the dinoflagellates cysts such as Paleocystodinium australinium, Subtilisphaera sp. and Andalusiella sp., microforaminiferal wall linings, pollens and spores established that the shales were deposited in nearshore to shallow marine environments. The presence of Cingulatisporites ornatus and Distaverrusporites simplex are indicative of marine regression that was followed by fluvial continental influence in anoxic bottom conditions that in turn favored the formation of coal seams in shales in the study area. The paucity of palynomorphs in the study area is inferred to have occurred because of the dry climatic condition that prevailed during the Upper Maastrichtian to Early Paleocene
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