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Effect of varying laser pulse parameters in laser direct metal deposition (LDMD) of Inconel 718 and Ti-6Al-4V have been shown to be quite complex and results in generation of two brittle phases Ti2Ni and TiNi3. Previous experimental study carried out by the authors discussed by Shah et al. (Sci World J 2014:6, 2014) the LDMD of Inconel 718 and Ti-6Al-4V, where all the sample developed cracks except with ones at low powder feed rate. In order to understand the effect of thermal and structural history on development of stresses during LDMD process, an extensive numerical modelling study has been carried out in the work. Thermal and structural analysis results are verified using the available experimental data. Residual stresses are calculated using numerical modelling in the clad region and at the interface of clad and substrate. Experimental and modelling results show that powder mass flow rate plays an important role in crack development during deposition of Inconel 718 and Ti-6Al-4V and it should be kept at minimum level in order to deposit crack-free samples.

Quartz Tuning Fork (QTF) based sensors are used for Scanning Probe Microscopes (SPM), in particular for near-field scanning optical microscopy. Highly sharp Tungsten (W) tips with larger cone angles and less tip diameter are critical for SPM instead of platinum and iridium (Pt/Ir) tips due to their high-quality factor, conductivity, mechanical stability, durability and production at low cost. Tungsten is chosen for its ease of electrochemical etching, yielding high-aspect ratio, sharp tips with tens of nanometer end diameters, while using simple etching circuits and basic electrolyte chemistry. Moreover, the resolution of the SPM images is observed to be associated with the cone angle of the SPM tip, therefore Atomic-Resolution Imaging is obtained with greater cone angles. Here, the goal is to chemically etch W to the smallest possible tip apex diameters. Tips with greater cone angles are produced by the custom etching procedures, which have proved superior in producing high quality tips. Though various methods are developed for the electrochemical etching of W wire, with a range of applications from scanning tunneling microscopy (SPM) to electron sources of scanning electron microscopes, but the basic chemical etching methods need to be optimized for reproducibility, controlling cone angle and tip sharpness that causes problems for the end users. In this research work, comprehensive experiments are carried out for the production of tips from 0.4 mm tungsten wire by three different electrochemical etching techniques, that is, Alternating Current (AC) etching, Meniscus etching and Direct Current (DC) etching. Consequently, sharp and high cone angle tips are obtained with required properties where the results of the W etching are analyzed, with optical microscope, and then with field emission scanning electron microscopy (FE-SEM). Similarly, effects of varying applied voltages and concentration of NaOH solution with comparison among the produced tips are investigated by measuring their cone angle and tip diameter. Moreover, oxidation and impurities, that is, removal of contamination and etching parameters are also studied in this research work. A method has been tested to minimize the oxidation on the surface and the tips were characterized with scanning electron microscope (SEM).

This study focuses on simplification of the Petri net model of a manufacturing system for reduction in the total number of elementary circuits to decrease the analysis time of systems during investigations. A flexible manufacturing system with a tool sharing environment has been developed and investigated using colored Petri nets. The proposed model is extended and implemented on large flexible manufacturing systems (FMSs) having multiple machines and tools. The main objective of this study is to reduce the resultant invariants, as the addition of parts, machines, and tools in black token Petri net models exponentially increases the resultant invariants. Various scenarios have been investigated and compared using the developed model. The structure of the developed colored Petri net (CPN) model allows grouping of the tools that reduces the total number of places in the model. Therefore, it is evident that the developed CPN model reduces the resultant invariant that results in reduced complexity of the system.

Historically, knowledge and skill were of prime focus in medical education, where as professionalism was perceived as an attribute to be acquired during their MBBS studies. In the past decade, trends have changed and graduating medical students are expected to competently deliver care in a professional manner. The selection of applicants with professional attributes at the time of admission is a stepping stone for the formation of a good doctor. This study was conducted to determine the students' and faculty's perception about aptitude of professionalism in the admission process in our setting.In this descriptive cross-sectional study an interactive/scenario-based conversation regarding institutional values, contribute to personal reflection of what will be expected of them in the medical profession and inclusion of such discussion in admission process was made to assess the aptitude of Professionalism of 100 students and 100 faculty members of Avicenna Medical College Lahore. After this conversation the questionnaires were filled by both the groups to record their responses on the aptitude of professionalism. The data was analysed to determine the response patterns of both the groups by using Pearson Chi-Square analysis through crosstabs. All analyses were carried out using SPSS-18.The response of students to professionalism discussion was more positively influenced (91%) compared to the faculty (59%), (p0.05). The students agreed that such scenarios do indicate what our institution values in its students and contribute to personal reflection of what will be expected of them in the medical profession. However, faculty agreed more (85%) than the students (67%) for inclusion of such scenarios in admission process, p0.05.Medical Colleges should include some form of assessment regarding aptitude of professionalism in the admission process to identify future medical students' capacity for professional behaviour. Future studies are needed to determine innovative interview strategies for this purpose.

Laser direct metal deposition (LDMD) has developed from a prototyping to a single metal manufacturing tool. Its potential for creating multimaterial and functionally graded structures is now beginning to be explored. This work is a first part of a study in which a single layer of Inconel 718 is deposited on Ti-6Al-4V substrate. Single layer tracks were built at a range of powder mass flow rates using a coaxial nozzle and 1.5 kW diode laser operating in both continuous and pulsed beam modes. This part of the study focused on the experimental findings during the deposition of Inconel 718 powder on Ti-6Al-4V substrate. Scanning electron microscopy (SEM) and X-ray diffraction analysis were performed for characterization and phase identification. Residual stress measurement had been carried out to ascertain the effects of laser pulse parameters on the crack development during the deposition process.