Influence of process parameters on torsional strength, impact toughness and hardness of dissimilar AISI 304 and AISI 1021 friction welded steels

In this present study an attempt was made to join austenitic stainless steel (AISI 304) with low alloy steel (AISI 1021) at different rotational speeds and at different axial pressures and then determining the strength of the joint by means of mechanical properties such as torsional strength, impact strength and micro hardness. The experimental results indicate that the rotational speed and the axial pressure have a significant effect on the mechanical properties of the joint and it is possible to improve the quality of the joint by selecting the optimum parameters

EVALUATION OF WEAR BEHAVIOR OF Al-Si ALLOY USING SiC AS THE REINFORCEMENT

The current study investigates the wear behavior of the SiC particles reinforced Al-Si alloy composites developed using the stir casting process. The results were obtained from the wear tests of the cast Al-Si alloy and prepared SiC reinforcement composites containing 3 % wt and 9 % wt using fine and coarse size SiC particles. The wear test of all the developed composites were done at different testing conditions with varying loads. The analysis of wear traces, as well as the wear debris, was done at every composition but at higher loads. It was observed that the wear resistance was improved with increasing the amount as well as decreasing the size of the SiC particles. However, the wear rate of the composites increases with increasing the applied load. From the microstructural study of specimen after the wear test one can conclude that both adhesive and abrasive wear mechanisms contribute for wear of SiC particle composites

EVALUATION OF WEAR BEHAVIOR OF Al-Si ALLOY USING SiC AS THE REINFORCEMENT

The current study investigates the wear behavior of the SiC particles reinforced Al-Si alloy composites developed using the stir casting process. The results were obtained from the wear tests of the cast Al-Si alloy and prepared SiC reinforcement composites containing 3 % wt and 9 % wt using fine and coarse size SiC particles. The wear test of all the developed composites were done at different testing conditions with varying loads. The analysis of wear traces, as well as the wear debris, was done at every composition but at higher loads. It was observed that the wear resistance was improved with increasing the amount as well as decreasing the size of the SiC particles. However, the wear rate of the composites increases with increasing the applied load. From the microstructural study of specimen after the wear test one can conclude that both adhesive and abrasive wear mechanisms contribute for wear of SiC particle composites

Synthesis, Characterization and Biological Evaluation of Novel 2,4-Dioxothiazolidine Derivatives as Potential Antimicrobial Agents

Objective: To develop a series of 2,4-dioxothiazolidine derivatives of aryl substituted cinnamic acid, characterization by elemental and spectral (IR, 1H-NMR) studies and antimicrobial study.Method: All compounds were synthesized from pure & standard substrates. Reactions were monitored by TLC & Melting points were determined by decibel melting point apparatus. The IR spectra were recorded on Perkin Elmer IR spectrophotometer using KBr pellets. Proton nuclear magnetic resonance spectra (1H NMR) were recorded on Brucker Avance II 400 NMR spectrophotometer. Antimicrobial activity was performed by measuring zone of inhibition.Results: All the synthesized compounds were purified and give very good spectra of IR & NMR. Compunds were studied for their antimicrobial activity in comparison to the standard drugs. Thz 9 was found the most active compound in this series, where Ciprofloxacin was used as a standard drug for antibacterial activity and Clotrimazole for antifungal activity.Conclusion: Compound Thz9 exhibited highest antimicrobial activity due to substitution of aryl ring by electron releasing methoxy groups at -ortho and -para position. Compound Thz9 was found more active than all other dimethoxy substituted compounds, the reason behind it may be that dimethoxy substitutions at -ortho and -para position on aryl ring enhanced the binding of molecule with the target. Almost in all compounds propyl ester has higher activity than methyl, ethyl esters, which means that heavy carbon chain ester increase the antimicrobial activity.Â

Landscape Mapping and Tree Diversity Assessment of Pangi Valley: A Remote Tribal Area of Himachal Pradesh in Western Himalaya, India

Pangi valley in Chamba district of Himachal Pradesh is one of the remote tribal areas in Indian western Himalaya. The plant resources in its landscapes are flourishing under least anthropogenic conditions. For social upliftment of the tribals in this area, a number of developmental activities are being implemented by the government. A study was conducted for mapping of its landuse/landcover using satellite remote sensing to identify major forested landscapes in the region. It was followed by a detailed random stratified sampling of the forested landscapes for phytosociological estimation of its tree species. The 21.97 % of study area was estimated under forests followed by Scrublands and Grassy meadows (18.24 %). Majority of area (54.05 %) was Snow and Scree slopes. Among the forests, maximum area was occupied by Mixed Broad Leaved Forest LSE type (36.08%) followed by Cedrus deodara (26.94%) and Betula utilis (18.07%) forest LSE types. These species, owing to immense medicinal properties and value for their economic utilization, feature in threatened and endangered category list of plants. It is, therefore, recommended that the developmental activities may be implemented in scientific way, which may not pose threat to bioresources in this region

COMPARISON OF 1% CHLOROPROCAINE IN SUB-ARACHNOID BLOCK WITH OR WITHOUT FENTANYL FOR ENHANCED RECOVERY AFTER PERIANAL SURGERIES

Objective: Spinal anesthesia is a reliable and safe technique for procedures of lower abdomen, perianal surgeries, and lower limbs. The current availability of short acting local anesthetic agents like preservative free 1% chloroprocaine has renewed the interest for this technique in short- and ultra-short procedures. Opioids continue to be the most commonly added adjuvants in local anesthetics for potentiation of analgesic action. In this study, we investigated the effect of intrathecal fentanyl as an adjuvant to 1% chloroprocaine in patients undergoing perianal surgeries. Methods: This prospective, randomized, and comparative study was conducted in 80 ASA Physical status I and II adult patients (age 20–80 years) undergoing perianal surgeries under spinal anesthesia. Group A patients received 1% chloroprocaine 3 ml (30 mg) and 0.4ml saline and Group B patients received 1% chloroprocaine 3 ml (30 mg) with fentanyl 0.4 ml (20 μg). Primary objectives were duration of analgesia and time to unassisted ambulation. Onset and duration of sensory and motor blockade, maximum height of sensory block, 2 segment regression, hemodynamic parameters, time to voiding, home discharge eligibility, and any side effects were also recorded. Results: There were no significant differences in demographic characteristics and hemodynamic parameters. The duration of sensory block and duration of analgesia were statistically prolonged in Group B than Group A (p<0.001) without affecting recovery from motor block and time to unassisted ambulation. The adverse effects were comparable in both the groups. Conclusion: The addition of fentanyl to 1% chloroprocaine intrathecally prolonged the duration of analgesia and sensory block in patients undergoing perianal surgeries

Unstable distal radius fractures fixation with a 2.4 mm volar variable-angle locking plate: radiological and functional assessment

Background: The main objective of this observational study was to evaluate the functional and radiological outcome of variable angle volar plates in intra-articular distal end radius fractures. Methods: Patients with distal end radius fractures (AO type 3C) treated operatively between Jan 2020 and Dec 2020 and then followed up for at least 12 months. A total of 32 patients (11 men and 21 women) with a mean age of 51.9 years were included in the study. The functional outcome was assessed by using modified Mayo wrist score (MMWS), disabilities of the arm, shoulder, and hand (DASH) score, wrist range of motion (ROM) and grip strength relative to the uninjured side and radiological assessment of radial height, volar tilt, and radial inclination. Results: MMWS and DASH scores improved postoperatively over time. Signs of radiographic union started around 12 weeks after surgery. The most common complication observed was finger and wrist stiffness, which was resolved with active wrist and finger movements. Non-union or hardware-related complications/ late complications such as tendon irritation/attrition were not observed with variable angle volar locking plates. Conclusions: Distal end radius fracture fixation with variable angle plate gives favourable radiological and clinical outcomes. These results can be owed to features such as low profile, variable locking, anatomical design and implant biomechanics. The surgeon determined angulation of the distal row of screw fixation may decrease the incidence of joint penetration and improve fixation of radial styloid and lunate facet stability

An atypical adenomatoid odontogenic tumour in the mandible: a report of a paediatric case

An adenomatoid odontogenic tumour (AOT) is a rare odontogenic tumour that is often misdiagnosed as an odontogenic cyst. To acquire additional information about AOT, all reports regarding AOT that had been cited in ‘Pub Med’ since 1990 onwards were reviewed. AOT accounts for about 1–9% of all odontogenic tumours. It is predominantly found in young and female patients, is located more often in the maxilla, and in most cases is associated with an unerupted permanent tooth. The differential diagnosis between AOT and other odontogenic tumours such as ameloblastoma should be well made to avoid extensive ablative surgery. However, AOT frequently resembles other odontogenic lesions such as dentigerous cysts or ameloblastoma. Immunohistochemically, AOT is characterized by positive reactions with certain cytokeratins. For illustration a rare case of an AOT in the mandible is presented that had atypical findings such as buccolingual cortical perforation and resorption with displacement of adjoining teeth.Keywords: adenomatoid odontogenic tumor, dentigerous cyst, odontogenic tumor, paediatric cas