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This experimental study aims to deal with the improvement of process performance of electric discharge drilling (EDD) for fabricating true blind holes in titanium alloy Ti6Al4V. Micro EDD was performed on Ti6Al4V and blind holes were drilled into the workpiece.

The effects of input parameters (i.e. voltage, capacitance and spindle speed) on responses (i.e. material removal rate, tool wear rate and surface roughness [SR]) were evaluated through response surface methodology. The data was analyzed using analysis of variance and multi-optimization was performed for the optimized set of parameters. The optimized process parameters were then used to drill deeper blind holes.

Blind holes have few characteristics such as SR, taper angle and corner radius. The value of corner radius reflects the quality of the hole produced as well as the amount of tool roundness. The optimized process parameters suggested by the current experimental study lower down the response values (i.e. SR, taper angle and corner radius). The process is found very effective in producing finished blind holes.

This experimental study establishes EDD as a feasible process for the fabrication of truly blind holes in Ti6Al4V.

Involvement of lenders for PPP highway projects in India starts after the bid award. The post-award development phase of Toll and Annuity PPPs differ significantly in terms of potential risk assumed by lenders. This study aims to assess the impact of the transparency law on the post-award development phase of Toll and Annuity PPPs.

A unique dataset of 469 PPP highway projects implemented in India was used to conduct this empirical study. An OLS regression model was developed to assess the impact of the transparency law on the post-award development phase.

Enacting the transparency law increased the duration of the post-award development phase of Toll projects; however, its impact on Annuity projects was not significant. Moreover, Toll and Annuity projects with a longer post-award development phase had a shorter construction phase. The post-award development phase of the Toll projects was relatively more sensitive to technical, economic and location-specific variables than Annuity projects. Length of road stretch, duration of the concession period and individual income of end-users significantly impacted the duration of this phase of Toll projects.

Transparency law can improve risk mitigation of Toll projects during the post-award development phase.

The impact of transparency law on PPP projects has never been assessed. This study assesses its impact on the two forms of PPPs. It also highlights the determinants of this phase and how they differ for the two forms of PPPs.

The purpose of this study is to investigate the effect of the sintering temperature on the microstructural, mechanical and physical properties of Cu-SiC composites.

The powder metallurgy route was used to fabricate the samples. Cold compaction of powders was conducted at 250 MPa which was followed by sintering at 850°C–950°C at the interval of 50 °C in the open atmospheric furnace. SiC was used as a reinforcement and the volumetric fraction of the SiC was varied as 10%, 15% and 20%. The processed samples were metallurgically characterized by the scanning electron microscope (SEM). Mechanical characterization was done using tensile and Vickers’ micro-hardness testing to check the hardness and strength of the samples. Archimedes principle and Four-point collinear probe method were used to measure the density and electrical resistivity of the samples.

SEM micrograph reveals the uniform dispersion of the SiC particles in the Cu matrix element. The results revealed that the Hardness and tensile strength were improved due to the addition of SiC and were maximum for the samples sintered at 950 °C. The addition of SiC has also increased the electrical resistivity of the Cu-SiC composite and was lowest for Cu 100% while the relative density has shown the reverse trend. Further, it was found that the maximum hardness of 91.67 Hv and ultimate tensile strength of 312.93 MPa were found for Cu-20% SiC composite and the lowest electrical resistivity of 2.017 µ- Ω-cm was found for pure Cu sample sintered at 950 °C, and this temperature was concluded as the optimum sintering temperature.

The powder metallurgy route for the fabrication of the composites is a challenging task as the trapping of oxygen cannot be controlled during the compaction process as well as during the sintering process. So, a more intensive study is required to overcome these kinds of limitations.

As of the author’s best knowledge, no work has been reported on the effect of sintering temperature on the properties of the Cu-SiC composites which has huge potential in the industries.

This paper aims to determine the optimum parametric settings for yielding superior mechanical properties, namely, ultimate tensile strength (UTS), yield strength (YS) and percentage elongation (EL) of AZ91D/AgNPs/TiO₂ hybrid composite fabricated by friction stir processing.

An empirical model has been developed to govern crucial influencing parameters, namely, rotation speed (RS), tool transverse speed (TS), number of passes (NPS) and reinforcement fraction (RF) or weight percentage. Box Behnken design (BBD) with four input parameters and three levels of each parameter was used to design the experimental work, and analysis of variance (ANOVA) was used to check the acceptability of the developed model. Desirability function analysis (DFA) for a multiresponse optimization approach is integrated with response surface methodology (RSM). The individual desirability index (IDI) was calculated for each response, and a composite desirability index (CDI) was obtained. The optimal parametric settings were determined based on maximum CDI values. A confirmation test is also performed to compare the actual and predicted values of responses.

The relationship between input parameters and output responses (UTS, YS, and EL) was investigated using the Box-Behnken design (BBD). Silver nanoparticles (AgNPs) and nano-sized titanium dioxide (TiO₂) enhanced the ultimate tensile strength and yield strength. It was observed that the inclusion of AgNPs led to an increase in ductility, while the increase in the weight fraction of TiO₂ resulted in a decrease in ductility.

AZ91D/AgNPs/TiO₂ hybrid composite finds enormous applications in biomedical implants, aerospace, sports and aerospace industries, especially where lightweight materials with high strength are critical.

In terms of optimum value through desirability, the experimental trials yield the following results: maximum value of UTS (318.369 MPa), maximum value of YS (200.120 MPa) and EL (7.610) at 1,021 rpm of RS, 70 mm/min of TS, 4 NPS and level 3 of RF.

This study intends to improve the quality of venous thromboembolism (VTE) prophylaxis practices including proper VTE risk assessment and the appropriate prophylaxis measures for surgical urology patients.

The authors applied the Six-Sigma define, measure, analyze, improve and control (DMAIC) improvement methodology in a pre–post interventional study that involved all adult patients above 18 years old indicated and scheduled for urology surgical interventions including endoscopic urological surgeries in a urology specialized 60-bed hospital. The pre-intervention sample included all patients meeting the inclusion criteria over a period of six months. Post-intervention sample included all patients meeting the inclusion criteria over a period of six months. The improvement areas included both the VTE risk assessment as well as the VTE prophylaxis prescription.

DMAIC methodology has achieved a substantial sustained improvement in surgical urology VTE prophylaxis practices with an average of 70% on both levels; VTE risk assessment practices and VTE prophylaxis prescribing practices were statistically significant. The post-intervention results also showed a statistically controlled process with no special cause variations. Based on the study results, the Six-Sigma DMAIC methodology can be considered of high value when applied in healthcare clinical practice improvement projects.

The project study includes some pitfalls that can be addressed as follows: 1. The lack of VTE rate incidence tracking. This limitation can be partly refuted when the authors conduct a literature review and explore that the VTE prophylaxis effectiveness had been proven with sufficient evidence to an extent that pushed several scientific societies to develop their own guidelines to support VTE prophylaxis. (Algattas et al., 2018). 2. Another limitation of this study can be that it handled only surgical patients and more specifically surgical urology patients. Of course, VTE prophylaxis is a crucial life-threatening problem not only for the surgical admitted patients but also for all the medical admitted patients either in hospital wards or ICUs. However, the prediction that surgical patients especially surgical urology patients are more prone to VTE development risk as they have -in several cases-two or three main additive risk factors which are age, procedure duration and malignancy in elderly men. (Tikkinen et al., 2014). So, the authors consider the study project to be a prototype that hopefully can be utilized for future study projects that will manage both other surgical specialty patients and medical patients on the national level and can track accurately and effectively report the VTE incidence rates.

Several recommendations can be extracted from the research project that is summarized in the following points: Paying focused attention to continuous healthcare quality improvement initiatives and projects as a main approach for healthcare improvement especially for the public health-related problems. This might be achieved through periodic region-specific or specialty-specific focus groups from which public health problems could be addressed and prioritized to be considered as a part of country healthcare campaigns regarding cost-utility and feasibility studies. The adoption of a system thinking approach in dealing with the improvement strategies; all efforts and resources are to be employed to achieve a common objective. This includes the generation of a national-wide electronic health information system that can aid in healthcare resource allocation and direct the healthcare efforts towards the most important, high-priority public health problems. Electronic national-wide health record is really an effort, and resources consuming activity, but actually, it's worth exerting efforts, and its valuable outcomes may be seen several years later. 3. Development of unified national specialized VTE prophylaxis pathways to standardize the patient-specific VTE prophylaxis plans. Standardization of healthcare pathways enables healthcare professionals to follow an evidence-based practice which will be reflected on the improvement of healthcare quality level, cost-effectiveness enhancement, and timely patient care on all levels especially in high critical areas like ER and ICU. 4. Incorporation of VTE prophylaxis costs in the universal health insurance diagnosis-related group (DRG) insurance packages and service pricing. Universal health insurance is a nationwide strategy that is aiming to cover all Egypt residents by the year 2030. Universal health insurance is being following the DRG reimbursement policy that is thought to control all the healthcare-associated costs so, the VTE prophylaxis costs shall be added as the main cost item to encourage all healthcare facilities to follow an evidence-based VTE prophylaxis pathway taking into consideration the high-risk patient categories who will definitely represent a high-cost burden on the long run if they suffer a VTE event.

DMAIC improvement methodology applications in healthcare are still relatively limited, especially on the clinical level. The study can be considered one of a kind in Egypt dealing with a comprehensive DMAIC methodology application on the clinical level.

Public-private partnership (PPP) highway projects in India are undertaken at both state and national levels, such that differences exist in how the procuring authorities manage project risk during the development and construction phase under different institutional frameworks. This study assesses the performance implication of the different administrative positionings of the procuring authority.

A data set of 516 PPP highway projects implemented in India formed the basis of this study. Means comparison, ordinary least squares (OLS) regression and seemingly unrelated regression were used to assess the impact of procuring authority on schedule performance.

The findings suggest that the state and the national highway projects were no different in achieving financial closure. However, the administrative positioning of the procuring authorities had a significant impact on other schedule performance variables. The construction of the state highway projects started quickly after the financial closure compared to the national highway projects. Moreover, the state highway projects were not only planned to be implemented at a faster rate but they were actually implemented at a faster rate and had a lower time overrun.

Procuring authorities under the state governments, being closer to the project, are better placed to manage project risk than those under the national government.

The administrative distance of the procuring authority from the PPP project and its implication on performance has never been studied.

The criteria importance through intercriteria correlation (CRITIC) and range of value (ROV) combined methods were used to determine a single index for all multiple responses.

This paper used cold metal transfer (CMT) and pulse metal-inert gas (MIG) welding processes to study the weld-on-bead geometry of AA2099-T86 alloy. This study used Taguchi's approach to find the optimal setting of the input welding parameters. The welding current, welding speed and contact-tip-to workpiece distance were the input welding parameters for finding the output responses, i.e. weld penetration, dilution and heat input. The L9 orthogonal array of Taguchi's approach was used to find out the optimal setting of the input parameters.

The optimal input welding parameters were determined with combined output responses. The predicted optimum welding input parameters were validated through confirmation tests. Analysis of variance showed that welding speed is the most influential factor in determining the weld bead geometry of the CMT and pulse MIG welding techniques.

The heat input and weld bead geometry are compared in both welding processes. The CMT welding samples show superior defect-free weld beads than pulse MIG welding due to lesser heat input and lesser dilution.