397 research outputs found
An FFT-based framework for predicting corrosion-driven damage in fractal porous media
Understanding fracture in cementitious materials caused by the deposition and
growth of corrosion products requires scale-bridging approaches due to the
large length-scale difference between the micro-pores, where deposition occurs,
and the structure, where deterioration manifests. Cementitious materials bear a
highly heterogeneous micro-structure owing to the fractal nature of
micro-pores. Simultaneously, a corrosion-driven fracture is a multi-physics
problem involving ionic diffusion, chemical reactions, and stress development.
This multi-scale and multi-physical character makes scale-bridging studies
computationally costly, often leading to the use of simplified fractal porous
media, which has important consequences for the quantitative interpretation of
the results. Recent advances in homogenization approaches using
Fast-Fourier-Transform (FFT) based methods have raised interest due to their
ease of implementation and low computational cost. This paper presents an
FFT-based framework for solving corrosion-driven fractures within fractal
porous media. We demonstrate the effectiveness of the Fourier-based spectral
method in resolving the multiple corrosion-driven mechanisms such as ionic
diffusion, stress development, and damage within a fractal porous
microstructure. Based on the presented methodology, we analyze the impact of
simplifying fractal porous media with simple Euclidean geometry on
corrosion-driven fracture. Our results demonstrate the importance of preserving
both the porosity and fractal nature of pores for precise and reliable modeling
of corrosion-driven failure mechanisms
Prioritization of Factors Impacting on Performance of Power Looms by Using AHP
The purpose of this paper is to identify the critical success factors influencing the performance of power loom textiles, to evaluate their impact on the organizational performance and to find out the effect of these factors on the organizational performance of small and medium-sized enterprises (SMEs) in the Sholapur (Maharashtra) industrial sector by using AHP. The methodology adopted is factors are identified through the literature survey and finalization of these factors is done by taking the opinion of Experts in the Indian context. By cognitive map the relation between these factors (direct and indirect effect) is determined and cause and effect diagram is prepared. Then these factors are arranged hierarchically and tree diagram is prepared. A questionnaire was designed and distributed among the experts; data is collected. By using Expert choice software data is filled to quantify by pair wise comparison of these factors and are prioritized. The weights demonstrate several key findings: local and global priority reveals that there is a substantial effect of the Human Resource, product style and volume on the organizational performance. The skill and technology up gradation impact on organizational performance. Maintenance plays important role in improving the organizational performances of the SMEs. Overall, the results showed the central role of the operational factors are important. The research is subject to the normal limitations of AHP. The study is using perceptual data provided by Experts which may not provide clear measures of impact factors. However, this can be overcome using more experts to collect data in future studies. Interestingly, the findings here may be generalisable outside Solapur like Ichalkarnji, Malegaon and Bhiwadi (Maharashtra).Solapur power loom SMEs should consider AHP as an innovative tool for quantification of factors impacting on performance and improving operational and organizational performance in today’s dynamic manufacturing environment. The finding suggests the notion that these critical success factors (CSFs) are to be studied carefully and improvement strategy should be developed. Moreover, the study emphasizes the need to link priority of factors to organizational performance and improvement. The study integrates the CSFs of performance and its quantification by using AHP and its effect on performance of power loom textiles. The indirect impact of underling and fundamental factors are considered. Very few studies have been performed to investigate and understand this issue. Therefore, the research can make a useful contribution. Key words: AHP, Factors and sub factors, Prioritization, power loom
Role of corticosteroids in Functional Endoscopic Sinus Surgery - a systematic review and meta-analysis
Background: The aim of our study is to systematically review the existing evidence on the role of corticosteroids in patients undergoing functional endoscopic sinus surgery (FESS). Methodology: Systematic search of MEDLINE (1950- 2014), EMBASE (1980-2014), metaRegister, Cochrane Library and ISI conference proceedings was carried out. Results: Eighteen randomised controlled trials with 1309 patients were included. Use of local and/or systemic corticosteroids with FESS was reported in four categories; operative, anaesthesia related, post-operative outcomes and risk of recurrence. Metaanalysis for operative outcomes demonstrated that, mean operative time (MD -10.70 minutes; 95% CI -15.86, -5.55; P <0.0001) and mean estimated blood loss (MD -28.32 mls; 95% CI -40.93, -15.72; P <0.0001) was significantly lower; and surgical field quality (MD -0.81; 95% CI -1.32, -0.30; P = 0.002) was significantly better in corticosteroid group. Meta-analysis showed that post-operative endoscopic scores (SMD -0.39; 95% CI -0.60, -0.17; P = 0.0004) were significantly better in corticosteroid group compared to no corticosteroid group. There was no increase in risk of sinusitis (RR 0.64; 95% CI 0.32, 1.30; P = 0.22) between use of corticosteroids and no corticosteroids; There was no significant difference in recurrence risk of chronic rhinosinusitis (CRS) in mixed population studies (RR 0.77; 95% CI 0.35, 1.70; P = 0.52) between the two groups but analysis of studies reporting on chronic rhinosinusitis with nasal polyps (CRSwNP) (RR 0.64;95% CI 0.45,0.91;P=0.01) showed significant difference in favour of the corticosteroid group. Conclusion: Pre-operative use of local and/or systemic corticosteroids in FESS, results in significantly reduced blood loss, shorter operative time and improved surgical field quality. Studies are limited on the intra-operative use of corticosteroids to reduce postoperative pain. Postoperative corticosteroids improve postoperative endoscopic scores in CRS and recurrence rates in cases of CRSwNP
Transonic and supershear crack propagation driven by geometric nonlinearities
Linear elastic fracture mechanics theory predicts that the speed of crack
growth is limited by the Rayleigh wave speed. Although many experimental
observations and numerical simulations have supported this prediction, some
exceptions have raised questions about its validity. The underlying reasons for
these discrepancies and the precise limiting speed of dynamic cracks remain
unknown. Here, we demonstrate that tensile (mode I) cracks can exceed the
Rayleigh wave speed and propagate at supershear speeds. We show that taking
into account geometric non-linearities, inherent in most materials, is
sufficient to enable such propagation modes. These geometric non-linearities
modify the crack-tip singularity, resulting in different crack-tip opening
displacements, cohesive zone behavior, and energy flows towards the crack tip.Comment: 8 pages, 4 figure
Beam-like topologically interlocked structures with hierarchical interlocking
Topologically interlocked materials and structures, which are assemblies of
unbonded interlocking building blocks, are a promising concept for versatile
structural applications. They have been shown to display exceptional mechanical
properties including outstanding combinations of stiffness, strength, and
toughness, beyond those achievable with common engineering materials. Recent
work established the theoretical upper limit for the strength and toughness of
beam-like topologically interlocked structures. However, this theoretical limit
is only achievable for structures with unrealistically high friction
coefficients and, therefore, it remains unknown if it is achievable in actual
structures. Here, we propose, inspired by biological systems, a hierarchical
approach for topological interlocking which overcomes these limitations and
provides a path toward optimized mechanical performance. We consider beam-like
topologically interlocked structures with geometrically designed surface
morphologies, which increases the effective frictional strength of the
interfaces, and hence enables us to achieve the theoretical limit with
realistic friction coefficients. Using numerical simulations, we examine the
effect of sinusoidal surface morphology with controllable amplitude and
wavelength on the maximum load-carrying capacity of the structure. Our study
discusses various effects of architecturing the surface morphology of beam-like
topological interlocked structures, and most notably, it demonstrates its
ability to significantly enhance the structure's mechanical performance
Intellectual Capital: A Case Study of Power Loom using AHP
The purpose of this paper is to identify the critical success factors of IC influencing the performance of power loom textiles, to evaluate their impact on the organizational performance and to find out the effect of these factors on the organizational performance of small and medium-sized enterprises (SMEs) in Maharashtra using AHP. The methodology adopted is factors are identified through the literature survey and finalization of these factors is done by taking the opinion of Experts in the Indian context. By cognitive map the relation between these factors is determined and cause and effect diagram is prepared. Then these factors are arranged hierarchically and tree diagram is prepared. A questionnaire was designed and distributed among the experts; data is collected. By using Expert choice software data is filled to quantify by pair wise comparison of these factors and are prioritized. The weights demonstrate several key findings: local and global priority reveals there is a substantial effect of the Human capital on the organizational performance. The work related experience contributes 34.21%, which has a greater impact on performance. Operational procedures or practices contribute 52% in order to improve the operational performance and hence organizational performance. Overall, the results showed the central role of the human capital is important. The research is subject to the normal limitations of AHP. The study is using perceptual data provided by Experts which may not provide clear measures of impact factors. However, this can be overcome using more experts to collect data in future studies. Interestingly, the findings here may be generalisable outside Maharashtra, India. AHP as an innovative tool for quantification of IC factors impacting on performance and improving operational and organizational performance in today’s dynamic manufacturing environment. The finding suggests the notion that these critical success factors (CSFs) are to be studied carefully and improvement strategy should be developed. Moreover, the study emphasizes the need to link priority of factors to organizational performance and improvement. The study integrates the CSFs of performance and its quantification by using AHP and its effect on performance of power loom textiles. Very few studies have been performed to investigate and understand this issue. Therefore, the research can make a useful contribution. Keywords: Intellectual capital, RBV, Power looms, Performance, AHP, Maharashtr
The key to the enhanced performance of slab-like topologically interlocked structures with non-planar blocks
Topologically interlocked structures are assemblies of interlocking blocks
that hold together solely through contact. Such structures have been shown to
exhibit high strength, energy dissipation, and crack arrest properties. Recent
studies on beam-like topologically interlocked structures have shown that, with
non-planar blocks, it is possible to reach levels of strength and
work-to-failure which are otherwise possible only with unrealistically high
friction coefficients. While non-planar blocks have been extensively used for
slab-like assemblies, many questions in that context are still not fully
understood. Specifically, it is unclear what are the exact characteristics of
non-planar surface morphologies which can potentially improve the enhanced
mechanical response of slab-like assemblies. In addition, it is unclear if
slab-like structures with non-planar surface blocks can reach a saturated
response with realistic friction coefficient values, as is the case with
beam-like ones. Here, we investigate such fundamental questions using numerical
simulations. We show that, by using non-planar blocks, it is possible to reach
saturation to the response capacity of the structure with a realistic friction
coefficient. Furthermore, we show that the key morphology parameter responsible
for the enhanced performance is the local angle of inclination at the top of
the loaded block. Lastly, we show that non-planar morphologies lead to improved
work-to-failure and ultimate deflection, which cannot be attained with
planar-faced blocks. These findings shed new light on topologically interlocked
structures with non-planar blocks, allowing for a better understanding of their
strengths and potential applications
Surface modification of thermally evaporated CdTe thin films for sensing application of organic compounds
The study involves the growth of bulk cadmium telluride (CdTe) by using vertical directional solidification (VDS) technique. The as grown CdTe compound has been used as a source material to deposit thin films onto glass substrates at room temperature by thermal evaporation technique under high vacuum conditions of 10-5 mbar. The thickness of film has been measured around 310 nm. Characterization of bulk CdTe compound and its thin films have been done by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM) and photoluminescence (PL) techniques. CdTe thin films have been then used for exposure to vapors of organic compounds such as acetone, formaldehyde, methanol, ethanol, benzene, toluene and chloroform in order to ascertain the use of these films for various sensors. The optical and micro structural properties of CdTe thin films have been studied using PL and AFM techniques so as to evaluate the sensing capabilities of CdTe thin film towards specific compounds which have been used for exposure
Income support programmes for the older adults in South Asia:a scoping review protocol
INTRODUCTION: South Asian countries are ageing and experiencing a rapid increase in proportion of the older population. Income support programmes are of central importance for the older adults as they may help to mitigate the poverty risks associated with ageing and losing the ability to generate income from labour. Evidence related to the income support programmes can help in understanding whether the programmes have been impactful. This scoping review will map the evidence (and gaps) related to income support programmes and create a base to identify the feasibility of future primary research and/or the scope of systematic reviews in the areas where evidence is available. METHODS AND ANALYSIS: The Joanna Briggs Institute scoping review methodology will be followed. Eligibility criteria for the scoping review will be based on the ‘PCC’ or the ‘Population–Concept–Context’ concept. Advanced search for the relevant articles will be conducted in MEDLINE (via PubMed), Embase, Scopus, Campbell Collaboration, 3ie International Initiative for Impact Evaluation and Web of Science. Additional resources search will be conducted in important organisational websites. Findings of the scoping review will be summarised using descriptive information (frequencies and percentages) for the available evidence on concept (ie, income support programmes), population characteristics and other study variables. ETHICS AND DISSEMINATION: The review is based on data from available literature, hence an ethical approval is not necessary. With this review, we attempt to provide recommendations to the research community and the policymakers about the currently available evidence and the research required for income support of older adults in South Asia, so that resources can be directed towards addressing the same. We plan to disseminate the findings through presentation in international conference and publication in a peer-reviewed journal. REVIEW REGISTRATION: Not registered
Effect of spacings and fertilizers on growth, yield and physical fruit quality of chilli (Capsicum annuum L.) cultivars
The effect of spacings and fertilizers on growth, yield and fruit quality (physical) of chilli (Capsicum annuwn) cultivars was studied at Bikaner (Rajasthan, India). The cultivar Local Desi recorded significantly higher plant height, dry weight per plant, weight and volume per fruit. However, cultivar NP 46 prodnced maximum number of fruits per plant, fruit yield per plant and fruit yield per hectare. Application of 100 kg N in combination with 25 kg P and 50 kg K per ha recorded highest fruits per plant. Maximum plant height, fresh weight and dry weight per plant, number of fruits and yield of fruits per plant were recorded in the widest spacing (55 cm x 55 cm); closest spacing (25 cm x 25 cm) produced highest fruit yield per hectare. The quality offruits was affected by spacings. Interaction effect of spacings, fertilizers and cultivars was non significant to affect growth, yield and fruit quality attributes.
 
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