16,537 research outputs found
Assessment of seawater mixing in a coastal aquifer by high resolution electrical resistivity tomography
No full textSeawater intrusion is a major problem in urbanized coastal regions of India which is due to over exploitation of groundwater for various purposes. This study was carried out with the objective of assessing the zone of mixing between seawater and groundwater in the coastal aquifer in south of Chennai, Tamil Nadu, India using high resolution electrical resistivity tomography. High resolution electrical resistivity tomography was carried out in five profiles perpendicular to the sea using IRIS make SYSCAL Pro-96 system with 2.5 m or 5 m inter-electrode separation. The maximum length of the profile was 170 m which resulted in a depth of investigation of 28.7 m. The apparent resistivity measured in this area varies from 0.3 ohm-m to 30,000 ohm-m. The apparent resistivity of saturated zone decreases towards the sea, indicating the influence of seawater. This was also confirmed by measuring the electrical conductivity of groundwater, which gradually increases from 156 μS/cm to 3430 μS/cm towards the sea. Further, the concentration profiles of electrical conductivity, sodium, chloride and chloride / bicarbonate ratio are compared with the high resolution electrical resistivity tomography profile. The distance of influence of seawater is comparatively high in northern part than in southern part of the area. The high resolution electrical resistivity tomography was effectively used to determine the effect of seawater mixing with groundwater. © IRSEN, CEERS, IAU
Syzygium namborense D. Dey, N. Devi & J. Sarma 2022, sp. nov.
No full textSyzygium namborense D. Dey, N. Devi & J. Sarma, sp. nov. (Figures 1–4; Table 1). Type:— INDIA. Assam: Golaghat district, Nambor Reserve Forest, Murphulani, 72m, 27 April 2019, 26 ° 22’36.53” N, 93 ° 46’55.49” E, D. Dey DDS2401 (holotype ASSAM!, isotype GUBH!). Syzygium namborense resembles S yzygium nervosum in having glabrous, chartaceous and aromatic leaves, paniculate inflorescence with second order branching, calyptrate flowers, numerous stamens and equal number of petals in the calyptra but differs in having more compressed branchlets with internodes 1.5–2 cm (versus internodes 6–7.7 cm in S.nervosum) and with up to 20 leaves (vs. up to 8 leaves), blades with acumen up to 0.6 cm (vs. up to 1 cm), strictly elliptic leaves with acuminate apex and cuneate base, greater number of lateral veins, intramarginal vein uniform along the blade, sessile yellowish white flowers with obconical hypanthium (vs. greenish white flowers with campanulate hypanthium and pedicel to 2 cm) and 20–30 ovules per locule (vs. 12–15 ovules per locule). Tree 8–15 m tall, 45–52 cm in diameter at body height. Bark coarse, olive green outside eventually turning into black, pale white inside. Branchlets terete, compressed, each with up to 20 leaves at a time, old branchlets greyish white, dry, young branchlets green, fleshy. Nodes thick, slightly angular, 1.5–2 cm apart. Leaves with petioles 1.2–2.5 cm long, the blades simple, opposite and decussate, chartaceous, glabrous, elliptic, 5–18 × 1.1–6.5 cm, cuneate at base, entire to slightly repand at margins, acuminate at apex, pellucid punctuate on both the surfaces, midrib sulcate above, raised below, secondary nerves 13–15 at each side, prominent beneath, forming intramarginal loops near the margin, acumen ca. 0.6 cm long. Inflorescences panicles, usually on leafless old twigs, axillary, 54–65-flowered, main axis 5–7 cm long, bracts minute, 0.1–0.2 cm long, caducous. Flowers yellowish white, 1–1.2 cm long, sessile, calyptrate, the calyptra 0.2 × 0.2 cm, rhombic, often persistent; hypanthium pellucid punctuate, obconical, slightly tapering towards the base, 0.4–0.5 × 0.3–0.5 cm; sepals 4, free, succulent, deciduous, deltate-prolate, rarely attached to the calyptra; petals 4, unified into a calyptra, each 0.1–0.2 cm long, orange brown at the center, white at the periphery with thin longitudinal grooves, irregularly elliptic, pellucid punctate, shortly clawed; stamens white, 60–80 per flower, 0.2–0.5 cm long, filaments slender, anther sacs parallel, dorsifixed, dehiscing by longitudinal slits; style 0.45 cm long, slightly bent; stigma falcate; ovary with axillary placentation; o vules 20–30 per locule. Fruits not seen. Distribution, habitat and ecology:—So far, Syzygium namborense is known only from the tropical semi-evergreen forests of Murphulani, Nambor Reserve Forest, Golaghat district and moist deciduous forests of Donkamukam, Rongkhang Reserve Forest, West Karbi Anglong district of Assam (Figure. 4). It generally grows on open areas of forest edge mostly at the base of hilltops between 71–77 m elev. During the entire survey, only two populations of the species were recorded in Assam. The first population was recorded from Nambor RF consisting of 1 matured individual while the second population was recorded from Rongkhang RF consisting of 5 individuals. Both locations are severely affected by various anthropogenic factors like logging and human settlements. The other associated plants located in the type locality (Nambor RF) were Carallia brachiata (Loureiro 1790: 296) Merrill (1919: 249), Gynocardia odorata R. Brown (1820: 95), Mangifera indica Linnaeus (1753: 200) and Syzygium cumini (Linnaeus 1753: 471) Skeels (1912: 25), whereas Syzygium nervosum, Clerodendrum glandulosum Lindley (1844: t. 19) and Chromolaena odorata (Linnaeus 1759: 1205) R.M. King & H. Robinson (1970: 204) were located in the other locality (Rongkhang RF). Note:—The leaves and flowers give off a strong fruity aroma and harbor a large number of insects, especially ants. They gather around at every node in large numbers and feed on the oozing sap (Figure 2C). Phenology:—Flowering occurs from April to June. Fruits were not seen. Paratypes:— INDIA. Assam: Golaghat district, Nambor Reserve Forest, Murphulani, 72m, 27 April 2019, 26 ° 22’36.53” N, 93 ° 46’55.49” E, D. Dey DDS2403 (GUBH!); West Karbi Anglong district, Rongkhang Reserve Forest, Donkamukam, 76m, 18 August 2019, 25 ° 58’0.65” N, 92 ° 43’2.39” E, J . Sarma JS 1500 (GUBH!). Etymology:—This new species is named after the type location, Nambor Reserve Forest of Assam. Affinities:— Syzygium namborense has resemblances with Syzygium nervosum with which it is compared in the diagnosis and in Table 1.Published as part of Dey, Debolina, Sarma, Jatindra & Devi, Nilakshee, 2022, Syzygium namborense (Myrtaceae), a new species from Assam, India, pp. 133-140 in Phytotaxa 538 (2) on page 134, DOI: 10.11646/phytotaxa.538.2.5, http://zenodo.org/record/633368
AFM study of the oxide film formed on dual phase Fe3Al-Fe3AlC intermetallies
No full textThe topography of the oxide film formed during initial stage of oxidation at 800 degreesC on the Fe3Al and Fe3AlC phases in an Fe- 16Al-0.5C alloy was analyzed using atomic force microscopy. The oxide film formed on the carbide phase was found to be thicker than that on the matrix, and the difference in thickness between two layers was around 0.5 mum. This was related to the presence of low Al content in the Fe3AlC phase compared with that in the Fe3Al phase. Due to different rate of oxidation in Fe3Al and Fe3AlC phases, the Fe- 16Al-0.5C alloy does not follow the parabolic rate behaviour. (C) 2004 Elsevier Ltd. All rights reserved.The author VSR thanks Prof. V.S. Raja of corrosion
science and engineering program, Indian Institute of
Technology, Bombay and Dr R.G. Baligidad of Defense
Metallurgical Research Laboratory, Hyderabad, India for
providing the material
Open access self-archiving: An author study
No full textThis, our second author international, cross-disciplinary study on open access had 1296 respondents. Its focus was on self-archiving. Almost half (49%) of the respondent population have self-archived at least one article during the last three years. Use of institutional repositories for this purpose has doubled and usage has increased by almost 60% for subject-based repositories. Self-archiving activity is greatest amongst those who publish the largest number of papers. There is still a substantial proportion of authors unaware of the possibility of providing open access to their work by self-archiving. Of the authors who have not yet self-archived any articles, 71% remain unaware of the option. With 49% of the author population having self-archived in some way, this means that 36% of the total author population (71% of the remaining 51%), has not yet been appraised of this way of providing open access. Authors have frequently expressed reluctance to self-archive because of the perceived time required and possible technical difficulties in carrying out this activity, yet findings here show that only 20% of authors found some degree of difficulty with the first act of depositing an article in a repository, and that this dropped to 9% for subsequent deposits. Another author worry is about infringing agreed copyright agreements with publishers, yet only 10% of authors currently know of the SHERPA/RoMEO list of publisher permissions policies with respect to self-archiving, where clear guidance as to what a publisher permits is provided. Where it is not known if permission is required, however, authors are not seeking it and are self-archiving without it. Communicating their results to peers remains the primary reason for scholars publishing their work; in other words,
researchers publish to have an impact on their field. The vast majority of authors (81%) would willingly comply with a mandate from their employer or research funder to deposit copies of their articles in an institutional or subject-based repository. A further 13% would comply reluctantly; 5% would not comply with such a mandate
Firearm suicide decedents in the Republic of Ireland, 1980–2005
No full textObjectives
To compare the sociodemographic characteristics of firearms suicide decedents and other suicide decedents in the Republic of Ireland between 1980 and 2005.
Study design
A cross-sectional study of sociodemographic characteristics of those who committed suicide with a firearm and those who committed suicide by an alternative method.
Methods
Suicide data from 1980 to 2005 inclusive, provided by the Central Statistics Office of Ireland, were analysed. For the purpose of this paper, suicide method was collapsed into two groups: firearm-assisted suicide (FAS) and non-firearm-assisted suicide (n-FAS). Differences in gender, marital status (married vs not married), area of residence (urban vs rural), agri-employment (agri-employed vs not agri-employed) and age were examined between the two groups. A logistic regression is presented using suicide method (FAS vs n-FAS) as the criterion variable and individual factors as predictors.
Results
In total, 9674 suicides were recorded from 1 January 1980 to 31 December 2005. Seven hundred and ninety-three of these were FAS and 8881 were n-FAS. For both suicide profiles, the deceased were predominantly male, living in a rural setting and not married. However, this profile was more salient in the FAS group. In comparison with the n-FAS group, a greater proportion of the FAS decedents were male [χ2(1)=152.5, P≤0.0001, odds ratio (OR)=4.5, 95% confidence interval (CI) 3.4–6.1], from a rural setting [χ2(1)=153.5, P≤0.0001, OR=4.4, 95%CI 3.2–5.6) and agri-employed [χ2(1)=21.3, P≤0.0001, OR=1.5, 95%CI 1.3–1.8). FAS decedents were significantly younger than n-FAS victims, although the size of this effect was small (z=−8.4, P<0.0005, r=−0.1). There was no difference in marital status between the two groups.
Conclusions
Risk factors for FAS should inform policy-making in this area, with particular attention paid to protecting young males resident in rural settings. Consideration should be given to targeting agri-employed individuals as a specific at-risk group
Average per-author h-index vs Average REF Impact Score.
No full textAverage per-author h-index vs Average REF Impact Score.</p
Proportion of junior vs. senior authors positioned first in the author byline of POA publications.
No full textProportion of junior vs. senior authors positioned first in the author byline of POA publications.</p
Compressible vs. incompressible pore water in fully-saturated poroelastic soil
No full textThis thesis aims to contribute to the understanding of how waves interact with soil. It is crucial for various applications in Civil Engineering to analyze the behaviour of soil and to understand the physics behind it. This master thesis contributes to this understanding via studying the impact of the boundary conditions on the model results with the aim of being able to model interaction between waves and soil.We assume a media that is poroelastic and fully-saturated, unless stated otherwise. We also assume that the porous media consists of incompressible soil particles and pore water particles that may either be compressible or incompressible. The main goals of this thesis are (1) to describe the response of porous media to transient hydraulic loads using numerical methods like the Finite-Element Method, and (2) to apply it to a one-dimensional case whereby a sandbed is subjected to waves. Currently, it is common to predict the changes in pore water pressures in porous media subjected to transient hydraulic loads using Biot’s model, which often assumes compressible pore water, assumes zero effective stresses on the surface of the seabed, and assumes that the wave load is completely carried by the pore water pressure only. Recently, a new model is proposed by Van Damme and Den Ouden-Van der Horst suggesting that transient hydraulic loads acting on a porous medium affect both the pore water pressures and effective stresses in soils. Note that this makes sure that the momentum balance equations are satisfied throughout the computational domain and its boundaries. The boundary conditions in this case do not satisfy Terzaghi’s effective stress principle, whereas the standard has been to impose Terzaghi’s effective stress principle when solving Biot’s equations. Terzaghi’s principle states that the sum of the effective stresses and pore water pressures must equal the hydraulic loads, whereas Biot’s model is in line with this principle.The model of Biot and the new model of Van Damme and Den Ouden-Van der Horst describe the physics differently which can have a large impact on the results. For example, the assumption of compressibility can significantly impact the distribution of the effective stress in the soil and thus the results.Biot’s model is more sensitive for changing the compressibility parameter than the new model. Both models give similar solutions to the water pressure. However, they give different solutions to the other variables like the volumetric strain and displacements which appear in both models. Furthermore, the new model in one dimension is in line with the momentum balance equations and satisfies the volume balance equation. On the other hand, the standard is to solve Biot’s model by imposing Terzaghi’s principle at the boundary. For the new model we found promising results for the water pressure, when validating with the data of two experiments. At the end, which model predict the best solutions for volumetricstrain, water pressure and displacements depends on what kind of problem the model is used for and the corresponding physics. The used code can be found at https://github.com/fpmklein/Compressiblevs.-incompressible-pore-water-in-fully-saturated-poroelastic-soil.https://github.com/fpmklein/Compressible-vs.-incompressible-pore-water-in-fully-saturated-poroelastic-soil The used code for this master thesis.Applied Mathematic
EasyCompress: Automated Compression for Deep Learning Models
No full textOver the past years the size of deep learning models has been growing consistently. This growth has led to significant improvements in performance, but at the expense of increased computational resource demands. Compression techniques can be used to improve the efficiency of deep learning models by shrinking their size and computational needs, whilepreserving performance.This thesis presents EasyCompress, an automated and user-friendly tool to compress deep learning models. The tool improves on existing compression research by focusing on generalizability and practical usability, in three ways. Firstly, it aligns with specific compression objectives and performance requirements, ensuring the compression accomplishes its intended goal effectively. Secondly, it employs flexible compression techniques, so that it is applicable to a diverse set of models without requiring deep model knowledge. Finally, it automates the compression process, eliminating difficult and time-consuming implementationefforts.EasyCompress intelligently selects, tailors, and combines various compression techniques to minimize model size, latency, or number of computations while preserving performance. It employs structured pruning to reduce the number of parameters and computations, uses knowledge distillation techniques to ensure better accuracy recovery, and uses quantization to achieve additional compression.The tool’s effectiveness is evaluated across diverse model architectures and configurations. Experimental results on a range of models and datasets demonstrate its ability to reduce the model size at least 5-fold, inference time by at least 1.5-fold, and the number of computations by at least 3-fold. Most compression rates are even higher, reaching up to 10, 20, and even 100-fold reductions.The tool is available online at https://thesis.abelvansteenweghen.com.https://thesis.abelvansteenweghen.com Deployed version of the web app. https://github.com/abel-vs/thesis GitHub repository containing the thesis code. https://github.com/abel-vs/thesis-app GitHub repository containing the web app code.Computer Science | Software Technolog
Comparing continuous and dichotomous scoring of the balanced inventory of desirable responding
No full textThe Balanced Inventory of Desirable Responding (BIDR; Paulhus, 1994) is a widely used instrument to measure the 2 components of social desirability: self-deceptive enhancement and impression management. With respect to scoring of the BIDR, Paulhus (1994) authorized 2 methods, namely continuous scoring (all answers on the continuous answer scale are counted) and dichotomous scoring (only extreme answers are counted). In this article, we report 3 studies with student samples, and continuous and dichotomous scoring of BIDR subscales are compared with respect to reliability, convergent validity, sensitivity to instructional variations, and correlations with personality. Across studies, the scores from continuous scoring (continuous scores) showed higher Cronbach's alphas than those from dichotomous scoring (dichotomous scores). Moreover, continuous scores showed higher convergent correlations with other measures of social desirability and more consistent effects with self-presentation instructions (fake-good vs. fake-bad instructions). Finally, continuous self-deceptive enhancement scores showed higher correlations with those traits of the Five-factor model for which substantial correlations were expected (i.e., Neuroticism, Extraversion, and Conscientiousness). Consequently, these findings indicate that continuous scoring may be preferable to dichotomous scoring when assessing socially desirable responding with the BID
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