Modified Dugdale Model

A precise determination of the influence of plastic yielding on the deformation and failure at a crack tip is needed for accurate predictions of the behavior of cracked bodies under static load large enough to cause fracture, and subcritical repetitive loads which cause fatigue. The catastrophic growth of cracks in plates under monotonically increasing load depends on a number of factors. A general view concerning the behavior of material at the leading edge of a crack is that plastic flow and subsequent fracture of the material is influenced by factors such as strain hardening, strain rate, the state of stress, and temperature. Therefore, for a proper understanding of fracture mechanism it is essential to determine appropriate inelastic solutions describing the behavior of plastic zone as a function of loads and mechanical properties. The elastic-plastic problem has been considered by Rosenfield et al. and Swedlow. Rosenfield has described experiments revealing the shapes and extent of the plastic zone in front of notches and cracks. While these analyses have produced information to indicate the role of plasticity in notched or cracked plates, they have yet to produce a criterion for fracture useful to the designer. Dugdale model for static yielding at the tip of the crack has been considered by Newman and extended to include the. influence of stress-strain curve on the plastic zone size and subsequently on the fracture strength of the plate. A fracture toughness equation which accounts for non-perfect plasticity has been derived by him for the uniformly loaded plate. Elastic-plastic crack problems in plane strain and plane stress have been discussed by Rice through the use of deformation and incremental plasticity theories. Nevertheless, his treatment provides an insight to the inelastic fracture. In the present work, Dugdale model for static yielding at the crack tip has been used and then modified to include the effect of strain-hardening on the plastic zone size and crack tip displacement. An attempt has been made to determine the plastic energy dissipation for the strain hardening material. These properties of material are influenced by factors such as the state of stress, strain rate, and the test temperature. In the present work, only the case of plane stress at room temperature for rate-insensitive material is considered. Many attempts have been made in recent years to establish a satisfactory relationship between engineering design parameters and cyclic crack growth rates. Generally, these proposed relationships indicate that the fatigue crack growth rate is dependent upon the alternating stress level and the current crack length. The main objective of the present work was to modify the Dugdale model to include the influence of strain hardening on the plastic zone size and crack tip displacement. For a given stress level, both plastic zone size and tip displacement decrease with increasing strain hardening. For the non-hardening case, the modified Dugdale model coverages very well to the original Dugdale model

Continuous Access of Broadcast Data Using Artificial Pointers in Wireless Mobile Computing

In a ubiquitous information environment, massive number of users carrying their portable computers can retrieve information anywhere and anytime using wireless mobile computing technologies. Wireless data broadcasting as a way of disseminating information to the large number of clients, has an inherent advantage by providing all types of users global access to information. An adaptive access method, which tolerates the access failure, has been proposed in an error-prone mobile environment. However the influence of version bits to deal with the updates of the broadcast data has not been exploited for the broadcast with modified but the same size and structure update. The basic idea is to distinguish the type of update that does not influence the change in the size and structure of the broadcast has been introduced. To deal with the types of updates, we classified the users in mobile computing environment into the users in system and the new users. In the proposed continuous algorithms, the user in systems record the previous result and use it efficiently to access the desired records with less number of probes in the broadcast, which is updated by a stream of same size and structure bits. In the performance analysis, the experimental results show that the proposed modified progression method has the best performance, as it requires the minimum cost to access the broadcast data

The Mediating Role of NIM on Market Structure and Bank Performance: Empirical Confirmation from Listed Nepalese CBs

This study examined the mediating role of net interest margin (NIM) on the nexus between market structure and banks’ performance. Two ordinary least-squares models with a path analysis model were applied to analyze the data. The first regression model measured the indirect effects of market structure, total assets, geographic expansion, and specialization on ROA through NIM and revealed that the higher market share of loans positively effects on bank’s performance and statistically insignificant. Similarly, the geographic expansion was observed to hurt the bank’s ROA, but statistically insignificant. On the other hand, the indirect effect of total asset size and specialization was negative, but the first one was statistically significant, and the second was statistically insignificant. The result of the second regression model measured the direct effect of antecedent variables on the ROA and revealed that the market structure, geographic expansion, and specialization were negatively related to performance measure ROA. However, the direct effect of total assets size was positively related to ROA and statistically significant. The results of the two regression models based on total effects revealed that a higher bank size appeared favorable to Nepalese CBs and was found to have positive effects on ROA but the geographic expansion was a negative effect on ROA, and statistically significant. The results of the study might be helpful to Nepalese bankers, regularity authorities, and other concerned stakeholders to take an effective decision about the direct, indirect, and total effects of chosen antecedent variables on consequent variables through the mediating role of NIM

Aflatoxins: Food Safety, Human Health Hazards and Their Prevention

Aflatoxins (AFTs) are group of secondary metabolites produced by filamentous fungi such as Aspergillus flavus, A. parasiticus, A. nomius, and Emericella nidulans. AFTs contaminate foods, feeds, other raw ingredients used to produce them and that pose a significant threat to human health. These toxins designated as aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), and aflatoxin G2 (AFG2), aflatoxin M1 (AFM1) and aflatoxin M2 (AFM2) are hydroxylated metabolites form of AFB1 and AFB2 are known as difuranocoumarin compounds. Naturally, these AFs have carcinogenic, teratogenic and mutagenic effects and caused several metabolic disorders such as aflatoxicosis in domestic animals and humans worldwide. For the increasing in cancer incidences these risk factors are liable. AFB1 is 1000 times more potent hepatocarcinogen found in food then benzo (α) pyrene carcinogen. This chapter offers contamination sources, effects and their controlling approaches to confirm the food safety

DSTP-AN: A Distributed System for Transaction Processing Based on Data Resource Migration in ATM Networks

The dynamic migration of data resources has become a strong tool for transaction processing in broadband networks such as ATM. In this paper, a distributed system that takes advantage of data resource migration for transaction processing in ATM networks has been proposed. The proposed system provides mechanisms to select the transaction processing method, to migrate data resources in a way that reduces the time delay and message traffic in locating and accessing them. The first mechanism selects one of the two transaction processing methods: the traditional method that uses two phase commit protocol and other new method based on data resource migration. The second mechanism attempts to improve performance by making each site follow a local policy for directing requests to locate and access data resources as well as migrating them through the system. For this, a new scheme that focuses on reducing the time delay and message traffic needed to access the migratory data resources is proposed. The performance of the proposed scheme has also been evaluated and compared with one of the existing schemes by a simulation study under different system parameters such as frequency of access to the data resources, frequency of data resource migrations, scale of network, etc

Nutritional status vis-a-vis iodine deficiency in children of "Save Our Soul"children’s village in rural Varanasi: a micro-level study

Background: There is paucity of data with regard to the Iodine deficiency in an organized sector like SOS children’s village which is an independent, non-governmental, social development organization located in urban Varanasi. Uttar Pradesh is one of the endemic states for goiter. It is expected that similar situation of goiter may prevail in children as well. It is a matter of concern that micro nutrient deficiency and under-nutrition may exist side by side. The objectives of the study were to assess nutritional status and find out the extent of Iodine deficiency in the study subjects, to find out the association between under nutrition and Iodine deficiency and to find out the Iodine content of salt used for cooking in the family.Methods: 118 children of age group 6 to 15 years, from a Non-Governmental Organization (Save Our Soul) in Rural Varanasi constituted materials of the study. Consent from the director of the institution and assent from the individual children was taken prior to examination. All the subjects were examined clinically for the Presence of Goiter. They were subjected to weight and height recording following standard technique. Salt samples from the houses were tested by spot Iodine detection kit.Results: In case of 72.6% female and 91.3% male subjects, BMI for age was <100% of the respective reference values; in all 76.3% subjects belonged to this category. Presence of Goiter among male children was 34.7% and among female children it was 22.2% and overall it was 24.6%. Significant association was observed between nutritional status and iodine deficiency (p<0.05). In 37.5% of salt samples, iodine content was 7 ppm and rest 62.5% shows iodine content 15ppm.Conclusions: Nutritional status of the children under reference was far from being satisfactory. High prevalence of Goiter is matter of serious concern. Iodized salt consumption in the houses was up to the mark but Iodine content of the salt samples from houses was not satisfactory

Utjecaj fluorida proizvedenih aluminijskim industrijskim postrojenjem na biljke i područja nastanjena ljudima

Fluorine is a highly reactive common element that does not occur in nature in the elemental state. It exists in the form of fluorides and accounts for about 0.3 g/kg of the Earth’s crust. Generally, it is found in the form of a number of minerals like fluorspar, cryolite and fluor-apatite. Fluoride has both positive and negative effects on individual health. Fluoride, in the form of fluorspar and cryo- lite is distributed extensively in the lithosphere, and is renowned as the thir- teenth most common among elements in the earth’s crust. Hydrogen fluorides in gaseous form accumulate in the leaves of generally sensitive plants against a concentration gradient and therefore, considered as a most phytotoxic air pollut- ant and affects plants at extremely low concentration. As per our study, it is found that the fluoride impacts on fauna are in normal condition, but in coming times it may have adverse impact on fauna and flora of surroundings of Hindalco Industries Limited.Fluor je vrlo reaktivan element koji se u elementarnom obliku ne pojavljuje u prirodi. Postoji u obliku fluorida u zemljinoj kori, gdje se nalazi u omjeru od oko 0,3 g/kg. Općenito, nalazi se u obliku velikog broja minerala poput fluorita, kriolita i apatita. Fluorid ima i pozitivne i negativne učinke na ljudsko zdravlje. Fluorid, u obliku fluorita i kriolita, široko je rasprostranjen u litosferi, a poznat je i kao trinaesta najčešća tvar u Zemljinoj kori. Fluorovodici u plinovitom obliku nagomilavaju se u listovima uglavnom osjetljivih biljaka prema gradijentu koncentracije. Stoga se smatraju najfitotoksičnijim onečišćujućim tvarima u zraku, a djeluju na biljke i pri ekstremno niskim koncentracijama. Prema našoj studiji utvrđeno je da su učinci fluorida na faunu u uobičajenim okvirima, ali u budućnosti može imati štetan utjecaj na faunu i floru u okruženju tvornice Hindalco Industries Limited

Evaluation of mineral status in hypothyroidism in a tertiary care centre

Background: Hypothyroidism is known to be the commonest form of endocrine disorders and has been linked with disturbances in various minerals metabolism. Calcium, phosphorus and magnesium and trace element zinc are required for many enzymes in various metabolic pathways which are directly or indirectly regulated by thyroid hormones. Aim and objectives of the study was to estimate serum zinc, calcium, magnesium and phosphorus in hypothyroid patients, with the objectives to evaluate any relationship with TSH and to compare them with euthyroid controls.Methods: The analytical cross-sectional study included 50 hypothyroid subjects with TSH levels >4.5 mcg IU/mL and 50 euthyroid subjects of 20-50 years in RMCH, Bareilly. TSH was estimated by ECLIA, serum calcium and phosphorus were estimated by autoanalyzer and serum zinc & magnesium by the kit method using semi autoanalyzer. All the biochemical parameters were expressed as median with Interquartile Range (IQR). Mann-Whitney test was applied to compare the parameters of cases and control. Spearman’s rank correlation coefficient 2-tailed was used to correlate the parameters among the cases.Results: A significantly decreased level of serum calcium and increased level of serum magnesium and phosphorus were observed in hypothyroid cases. A significant negative correlation between TSH and serum calcium while a significant positive correlation of serum magnesium and phosphorus with TSH was observed.Conclusions: The indexed study indicates the significant effect of overt or subclinical hypothyroidism over the mineral status of the body which may have inconsistent effect over the various metabolism and enzymes and thereby clinical manifestations

Disrupted network architecture of the resting brain in attention‐deficit/hyperactivity disorder

Background Attention‐deficit/hyperactivity disorder (ADHD) is one of the most prevalent psychiatric disorders of childhood. Neuroimaging investigations of ADHD have traditionally sought to detect localized abnormalities in discrete brain regions. Recent years, however, have seen the emergence of complementary lines of investigation into distributed connectivity disturbances in ADHD. Current models emphasize abnormal relationships between default network—involved in internally directed mentation and lapses of attention—and task positive networks, especially ventral attention network. However, studies that comprehensively investigate interrelationships between large‐scale networks in ADHD remain relatively rare. Methods Resting state functional magnetic resonance imaging scans were obtained from 757 participants at seven sites in the ADHD‐200 multisite sample. Functional connectomes were generated for each subject, and interrelationships between seven large‐scale brain networks were examined with network contingency analysis. Results ADHD brains exhibited altered resting state connectivity between default network and ventral attention network [ P  < 0.0001, false discovery rate (FDR)‐corrected], including prominent increased connectivity (more specifically, diminished anticorrelation) between posterior cingulate cortex in default network and right anterior insula and supplementary motor area in ventral attention network. There was distributed hypoconnectivity within default network ( P  = 0.009, FDR‐corrected), and this network also exhibited significant alterations in its interconnections with several other large‐scale networks. Additionally, there was pronounced right lateralization of aberrant default network connections. Conclusions Consistent with existing theoretical models, these results provide evidence that default network‐ventral attention network interconnections are a key locus of dysfunction in ADHD. Moreover, these findings contribute to growing evidence that distributed dysconnectivity within and between large‐scale networks is present in ADHD. Hum Brain Mapp 35:4693–4705, 2014 . © 2014 Wiley Periodicals, Inc .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107992/1/hbm22504.pd