Development of a model for friction stir weld quality assessment using machine vision and acoustic emission techniques

The surface texture of friction stir weld is related to internal structure of weld. The statistical image parameters along good and defect weld regions are quantitatively evaluated for quality from the weld bead images, which are processed and analyzed using machine vision technique and X-ray radiography. The weld strength obtained along the weld regions showing similar variations in Acoustic Emission (AE) data, which was acquired during welding and image data of the weld bead are analyzed to assess the weld quality. The combined model developed using limiting values of image data and AE data along different regions of weld evaluate the weld quality more reliably. © 2015 Elsevier B.V. All rights reserved

Thermomechanical modeling and Evaluation to study peak temperature and Flow stress of Friction Stir welds of Aluminum Alloy 6061

This work involves three-dimensional thermomechanical modeling of Friction Stir Welding (FSW) process using general purpose Finite Element Analysis (FEA) simulation tool ‘Altair Hyperworks’ from the combined complementary effort of experimental evaluation and numerical modeling to understand FSW process. Thermal and mechanical behavior of the material which are mutually dependent are coupled together to simulate the FSW process model similar to the real time to evaluate the peak temperature and flow stress. The heat generation is governed by friction between tool and workpiece, plastic deformation and the temperature imposed subsequently on the material. The temperature distribution in the workpiece during FSW process of butt joining of aluminum alloy 6061-T6 is experimentally measured from the devised thermocouple layout at different locations on the workpiece in the welding direction. The temperature history and normal force predicted from simulated model is compared with that of experimental values and is found to be in good agreement validating the numerical model. Parametric study to determine the effects of tool rotational and traverse speed on the performance of weld is carried out by predicting peak temperatures, flow stress, strain rate and normal force. The peak temperature during welding is found to be increase as tool rotation speed is increased at constant traverse speed leading to formation of defects due to lower flow stress and high strain rate. On the other hand as the tool traverse rate is increased the total heat input decreased which decreases weld temperature at constant rotational speed increasing the flow stress leading to formation of defects. This provides better insight about the peak temperature, flow stress and strain rate developed at different tool speeds by numerical modeling without conducting costlier experiments. The results predicted from the numerical modeling leads to the better understanding of effect of flow stress and strain rate on normal force which can be measured during FSW to aid the assessment of weld performance

An experimental evaluation of gastro protective activity of paracetamol on ulcerogenicity of some NSAIDs in albino rats

Background: Fixed dose combinations (FDCs) of NSAIDs are commonly prescribed and extensively sold over the counter. An indiscriminate usage of them leads to toxicity, mainly involving gastrointestinal system. Paracetamol appears to have controversial reputation regarding its gastro protective action. In this background, the study was planned to evaluate gastro protective effect of paracetamol on the ulcerogenicity of some relatively new NSAIDs in their therapeutic and sub therapeutic doses.Methods: Gatric toxicity and gastric juice analysis- Pyloric ligation method was adopted for assessing the ulcer index of 3 NSAIDs namely aceclofenac, nimesulide and lornoxicam individually and in combination with paracetamol. Gastric juice collected was subjected for total juice volume, free acidity, combined acidity and total acid output.Results: Paracetamol produced non significant gastric damage similar to that of control. When co administered with therapeutic doses of aceclofenac, nimesulide and lornoxicam, there was significant decrease in their gastric toxicity in a uniform manner and the ulcerogenicity of these NSAIDs in sub therapeutic doses was not affected by paracetamol. This upholds the uniform gastro protective activity of paracetamol in this study and this could be explained by its anti acid secretory action on gastric juice.Conclusions: Paracetamol, itself has least gastric damaging property. When co administered with other NSAIDs, their toxicity is rather reduced than enhancing the mucosal damage by them. Thus FDCs of various NSAIDs available in market are partially justifiable

A comparative evaluation of analgesic and anti-inflammatory activities of two medicinal plants rubia cordifolia and cassia fistula in wistar albino rats

Background: Pain and inflammation are disabling accompaniments of many medical conditions. So, controlling both pain and inflammation assumes the top priority for the physician. Inflammation is a part of a complex biological response of vascular tissues to harmful stimuli such as pathogens, chemicals or irritants. Therapy of pain and inflammation has always been debatable.Methods: Rats were divided into 8 groups of 6 animals of each. The anti-inflammatory activity was studied with carrageenan induced rat paw edema and cotton pellet induced granuloma models. The analgesic activity was evaluated using Eddy’s hot plate model. The aqueous extract of Rubia cardifolia root and Cassia fistula leaf preparations were compared with Diclofenac in both acute and sub acute inflammatory models and also in pain model.Results: Various test result parameters were statistically analysed at P value <0.5. In Eddy's hot plate model both RC and CF preparations prolonged the response reaction time, while CF preparation showed longer reaction time than that of RC preparation. In carrageenan induced paw edema and cotton pellet induced granuloma models, both RC and CF preparations showed significant decrease in paw edema volume and granuloma dry weight respectively, but less than that of Diclofenac. RC preparation found to have dose dependant in inflammatory models.Conclusions: RC root and CF leaf preparations were compared head to head and they have been found to have significant dose dependant analgesic activity and dose independent acute and sub acute anti inflammatory activities. Though CF leaf preparation appeared to be a good analgesic than RF root preparation, but failed to do so as an anti inflammatory agent in both inflammatory models. But both test preparations were not equivalent to Diclofenac in all three models

An experimental evaluation of anti-inflammatory activities of some combined NSAID preparations in albino rats

Background: Non-steroidal anti-inflammatory drugs are among the most commonly used drugs across the globe and they are also available over the counter for minor symptoms of pain and inflammation. Their toxicity profile limits their continued usage and search is continuing for the better effective and safer agent.Methods: Interaction of paracetamol with diclofenac, ibuprofen and mefenamic acid were studied on carrageenan induced rat paw edema and cotton pellet induced granuloma models. Potentiation of these NSAIDs by paracetamol was also studied on same models.Results: Addition of paracetamol did not increase anti-inflammatory activity of diclofenac, ibuprofen and mefenamic acid in both acute and subacute models of inflammation. Paracetamol found to potentiate the ibuprofen action in anti-inflammatory model where as in subacute inflammatory model diclofenac action was potentited.Conclusions: Our study does not support the rationality of various fixed dose combination of NSAIDs with paracetamol available in market. Either NSAIDs to be used individually or their dose need to be decreased in fixed dose combination

Variable potentiation of analgesic anti- inflammatory activity of diclofenac by two medicinal plants rubia cordifolia and cassia fistula in wistar albino rats

Background: NSAIDS are commonly prescribed drugs in clinical practice. However, their usage is limited by their toxicity profile and research continues for an alternative therapy with higher efficacy and safety. Various plant preparations found to be safe and effective are emerging, but their interactions with synthetic drugs are not much known.Methods: Wistar rats were divided in to four groups of six animals each Rubia cordifolia (RC) root preparation and casissia fistula (CF) leaf preparation were studied with sub anti-inflammatory dose of diclofenac in various analgesic, acute and subacute inflammatory models and test results variables were expressed in mean reaction time, paw edema volume and granuloma weight respectively.Results: Various test results were tabulated, statistically analysed and significance was calculated at P value <0.5. Eddy’s hot plate model did not show any significant change, but carrageenan induced paw edema model and cotton pellet induced granuloma model showed comparable decrease in paw edema volume and granuloma dry weight.Conclusions: Diclofenac, a standard analgesic and anti –inflammatory was not potentiated in pain model but it was potentiated in carrageenan and cotton pellet granuloma models in a variable manner. CF potentiates acute anti-inflammatory action, whereas RC potentiates subacute anti-inflammatory actions of diclofenac

galaxieEST: addressing EST identity through automated phylogenetic analysis

BACKGROUND: Research involving expressed sequence tags (ESTs) is intricately coupled to the existence of large, well-annotated sequence repositories. Comparatively complete and satisfactory annotated public sequence libraries are, however, available only for a limited range of organisms, rendering the absence of sequences and gene structure information a tangible problem for those working with taxa lacking an EST or genome sequencing project. Paralogous genes belonging to the same gene family but distinguished by derived characteristics are particularly prone to misidentification and erroneous annotation; high but incomplete levels of sequence similarity are typically difficult to interpret and have formed the basis of many unsubstantiated assumptions of orthology. In these cases, a phylogenetic study of the query sequence together with the most similar sequences in the database may be of great value to the identification process. In order to facilitate this laborious procedure, a project to employ automated phylogenetic analysis in the identification of ESTs was initiated. RESULTS: galaxieEST is an open source Perl-CGI script package designed to complement traditional similarity-based identification of EST sequences through employment of automated phylogenetic analysis. It uses a series of BLAST runs as a sieve to retrieve nucleotide and protein sequences for inclusion in neighbour joining and parsimony analyses; the output includes the BLAST output, the results of the phylogenetic analyses, and the corresponding multiple alignments. galaxieEST is available as an on-line web service for identification of fungal ESTs and for download / local installation for use with any organism group at . CONCLUSIONS: By addressing sequence relatedness in addition to similarity, galaxieEST provides an integrative view on EST origin and identity, which may prove particularly useful in cases where similarity searches return one or more pertinent, but not full, matches and additional information on the query EST is needed

Insecticidal Evaluation of Bridelia Micrantha and Dalbergia Lactea Aqueous Extracts for the Control of Podagrica Uniforma (Jacoby) and Nisotra Dilecta (Jacoby) (Coleoptera: Chysomelidae) Infestation on Okra

Insect pest infestation is a major factor militating against okra production and farmers generally adopt synthetic insecticides for its management. A field trial was undertaken to evaluate the insecticidal potency of Bridelia micrantha and Dalbergia lactea for the management of Podagrica uniforma (Jacoby) and Nisotra dilecta (Jacoby) insect pest of okra (Abelmoschus esculentus L. Moench). The treatments consisted of aqueous leaf extracts of Bridelia micrantha and Dalbergia lactea and Cypermethrin as check; laid out in Randomized Complete Block Design and repli-cated three times. Data was collected on insect population before treatment application and 3 days after spraying of insecticides at 28, 35, 42, 56 days after planting (DAP). Yield parameters data collected were number of fruits and fruit weight. Results obtained showed that the plant extracts exhibited effectiveness in reducing the insect population and improved okra fruit yield compared to Cypermethrin. The order of effectiveness in decreasing sequence was found to be Cypermethrin ˃ D. lacteal ˃ B. micrantha. D. lacteal and B. micrantha crude extracts could be explored as promising insecticidal agents to provide valuable alternatives to chemical control of insect infestation on okra. Further study is recommended to determine the chemical constituents responsible for the plant insecticidal activity

Differential spatial modulation for high-rate transmission systems

This paper introduces a new differential spatial modulation (DSM) scheme which subsumes both the previously introduced DSM and high-rate spatial modulation (HR-SM) for wireless multiple input multiple output (MIMO) transmission. By combining the codeword design method of the HR-SM scheme with the encoding method of the DSM scheme, we develop a high-rate differential spatial modulation (HR-DSM) scheme equipped with an arbitrary number of transmit antennas that requires channel state information (CSI) neither at the transmitter nor at the receiver. The proposed approach can be applied to any equal energy signal constellations. The bit error rate (BER) performance of the proposed HR-DSM schemes is evaluated by using both theoretical upper bound and computer simulations. It is shown that for the same spectral efficiency and antenna configuration, the proposed HR-DSM outperforms the DSM in terms of bit error rate (BER) performance

Comparison of push-out bond strength of bioceramic sealer with bioceramic coated and non-bioceramic coated Guttapercha: an in vitro study

Background: The goal of the endodontic treatment is to achieve a fluid-tight impervious seal to prevent the ingress of bacteria and the occurrence of any pathology in future. The endodontic sealer plays a crucial role in obtaining the hermetic seal by filling all the spaces and by binding to the root dentin and to the core obturating material, which is usually gutta-percha. Aim: This study aimed to compare the push-out bond strength of Endosequence BC sealer with bioceramic coated gutta-percha and non-bioceramic coated gutta-percha. Materials and methods: A total of 36 extracted human maxillary central incisors were decoronated to standardize the root length of 15mm. Working length was determined and Biomechanical preparation for all the samples was done with a Mtwo (VDW Company) rotary file till 40/.06. Samples were randomly divided into three groups containing 12 teeth in each group based on the obturation procedure, namely Group 1: Endosequence BC sealer along with Endosequence bioceramic coated gutta-percha (n=12), Group 2: Endosequence BC sealer along with normal gutta-percha (n=12), Group 3: AH Plus sealer along with normal gutta-percha. All the samples were obturated using single cone technique. The specimens were sectioned orthogonally at middle third to obtain three sections of 1mm thick. All the samples were subjected to the push-out bond strength test with the universal testing machine. The data were subjected to one-way Analysis of Variance (ANOVA) followed by post hoc analysis. Results: Samples obturated with Endosequence BC sealer with Endosequence bioceramic coated gutta-percha showed the maximum push-out bond strength followed by Group 3 and Group 2.  One-way Anova showed significant differences (p=0.021) among the groups. In posthoc analysis, the specimens from group 1 exhibited significant differences (p=0.016) with the group 2 specimens. Conclusion: The push-out bond strength of Endosequence Bioceramic sealer with Endosequence Bioceramic coated gutta-percha was significantly higher than that of Endosequence Bioceramic sealer with normal gutta-percha and AH Plus sealer with normal gutta-percha