Comparative experimental investigations on novel joining technology based on microwave energy to produce SS2205-SS2205 joints

In this work, a novel joining technology has been developed by significantly modifying the existing older joining technology. Both methods have been based on using microwave energy. Metallic joints of SS2205-SS2205 have been developed by using the novel as well as old technology. In previous technology, formation of joints has been largely affected by the use of charcoal powder (susceptor), graphite sheet (separator) and filler powder (interface) for producing the joints. On the other hand, in the newly proposed method, the joints have been fabricated without using any charcoal powder, graphite sheet or filler powder. Graphite rods have been used instead of charcoal powder thereby improving speed and cleanliness of the process. Further, absence of charcoal powder has helped in getting rid of the charcoal feeder as well as the separator sheet; thereby ensuring an easier assembly set-up and reduced set-up time. Finally, filler powder has not been used in proposed method, thereby drastically reducing the material cost. Joints’ microstructure and mechanical properties have been characterized. Newly proposed method-based joints have been observed to possess better hardness, tensile strength and ductility due to better microstructural composition despite lower carbon content. Hardness, tensile strength and percentage elongation have also been observed to be better than previous results by 8%, 16.67% and 17.85%, respectively

Thermal performance evaluation of cellulose fibre as building insulation material

Space cooling has utilized lots of electricity in summers which has to be reduced by insulating inside of buildings. Thishas potential to reduce the environment pollution caused by higher expenditure of energy. The present work has the scope toevaluate thermal performance of a test model house providing cellulose fibre based cardboard insulation and compare theperformance with an uninsulated model. The addition of heat through roof, walls and net heat gain during the day hasremained lesser for insulated test model than uninsulated test model. The temperature of indoor air has stayed lesser in caseof insulated test model than the uninsulated test model during the day particularly in the interval from 12 hrs to 19 hrs Theindoor air temperature for the insulated test model has remained lesser by 7°C from 14 hrs till 16 hrs in comparison touninsulated test model. The energy and financial savings obtainable for summers has value of 144 kWh and Rs 864respectively for insulated test model. The carbon dioxide emitted has reduced for summers by 226 kg for insulated testmodel. Hence better thermal comfort conditions have existed in the insulated buildings

Filler powder free joining of SAF 2507 using selective microwave hybrid heating technique

Microwave Hybrid Heating (MHH) based joining of super duplex stainless steel (SAF 2507) with cross-sectionaldimensions 3.5 mm ×3 mm has been carried out for the first time by using a microwave applicator of 900 W operated at2.45 GHz for 400 s. Graphite rods have been used instead of traditionally used charcoal powder to serve as susceptormaterial. Graphite rods are good susceptor of microwave radiations therefore the presence of these rods helps in initiatingand carrying forward the joining process. Moreover, the melting temperature can be achieved for specimens underinvestigations through this novel process thereby eliminating the need of using any filler powder. Absence of filler powderreduces the process cost significantly. The joints have been mechanically characterized by Vickers micro-hardness andphysically characterized by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) tests. It hasbeen observed through these tests that micro-hardness of the joints was more than the base alloy due to transfer of carbonfrom graphite rods to the joint zone

Geospatial Semantics

Geospatial semantics is a broad field that involves a variety of research areas. The term semantics refers to the meaning of things, and is in contrast with the term syntactics. Accordingly, studies on geospatial semantics usually focus on understanding the meaning of geographic entities as well as their counterparts in the cognitive and digital world, such as cognitive geographic concepts and digital gazetteers. Geospatial semantics can also facilitate the design of geographic information systems (GIS) by enhancing the interoperability of distributed systems and developing more intelligent interfaces for user interactions. During the past years, a lot of research has been conducted, approaching geospatial semantics from different perspectives, using a variety of methods, and targeting different problems. Meanwhile, the arrival of big geo data, especially the large amount of unstructured text data on the Web, and the fast development of natural language processing methods enable new research directions in geospatial semantics. This chapter, therefore, provides a systematic review on the existing geospatial semantic research. Six major research areas are identified and discussed, including semantic interoperability, digital gazetteers, geographic information retrieval, geospatial Semantic Web, place semantics, and cognitive geographic concepts.Comment: Yingjie Hu (2017). Geospatial Semantics. In Bo Huang, Thomas J. Cova, and Ming-Hsiang Tsou et al. (Eds): Comprehensive Geographic Information Systems, Elsevier. Oxford, U

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

The Machining and Surface Modification of H13 Die Steel via the Electrical Discharge Machining Process Using Graphite Mixed Dielectric

Surface modification through electrical discharge machining (EDM) results in many advantages, such as improved surface hardness, enhanced wear resistance, and better micro-structuring. During EDM-based surface modification, either the eroding tool electrode or a powder-mixed dielectric can be utilized to add material onto the machined surface of the workpiece. The current study looks at the surface modification of H13 die steel using EDM in a dielectric medium mixed with graphite powder. The experiments were carried out using a Taguchi experimental design. In this work, peak current, pulse-on time, and powder concentration are taken into consideration as input factors. Tool wear rate (TWR), material removal rate (MRR), and the microhardness of the surface of the machined specimen are taken as output parameters. The machined surface’s microhardness was found to have improved by 159%. The results of X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) analysis and changes in MRR and TWR due to the powder-mixed dielectric are also discussed in detail

Design and manufacturing of abrasive jet machine for drilling operation

Wide application of Abrasive Jet Machine (AJM) is found in machining hard and brittle materials. Machining of brittle materials by AJM is due to brittle fracture and removal of micro chips from the work piece. Embedment of the abrasive particles in the brittle materials results in decrease of machining efficiency. In this paper design and manufacturing of AJM has been presented. Various parts of AJM have been designed using ANSYS 16.2 software. The parts are then manufactured indigenously as per designed parameters. The machine fabricated in this work will be used further for process optimization of AJM parameters for machining of glass and ceramics