140 research outputs found
Boosting Photocatalytic Activity Using Vanadium Doped Titanium Oxide with Reduced Graphene Oxide (RGO)/Semiconductor Nanocomposites
Textile waste materials are increasing day by day with the depletion of water and increasing the concentration of ions present in the water that produce toxicity. The sustainability of the materials to rule out this toxicity can be done by Reduced Graphene Oxide synthesized by modified Hummer’s method. The composite of V-doped TiO2 and RGO was synthesized by hydrothermal method and V-doped TiO2/RGO and perfluorocarbon synthesized by sonication. The product was characterized by the powder X-ray Diffraction method. It has confirmed the synthesis of the product. Ultraviolet/visible spectroscopy was employed to study the photocatalytic activity of the product for the degradation of methylene blue which is an organic dye and hazardous to the environment
Milling of Inconel 718: an experimental and integrated modeling approach for surface roughness
Inconel 718, a hard-to-cut superalloy is reputed for having poor machining performance due to its low thermal conductivity. Consequently, the surface quality of the machined parts suffers. The surface roughness value must fall within the stringent limits to ensure the functional performance of the components used in aerospace and bioimplant applications. One doable way to enhance its machinability is the adequate dissipation of heat from the machining zone through efficient and ecofriendly cooling environment. With this perspective, an experimental and integrated green-response surface machiningbased- evolutionary optimization (G-RSM-EO) approach is presented during this investigation. The results are compared with two base-line techniques: the traditional flooded approach with Hocut WS 8065 mineral oil, and the dry green approach. A Box-Behnken response surface methodology (RSM) is employed to design the milling tests considering three control parameters, i.e., cutting speed (vs), feed/flute (fz), and axial depth of cut (ap). These control parameters are used in the various experiments conducted during this research work. The parametric analysis is then accomplished through surface plots, and the analysis of variance (ANOVA) is presented to assess the effects of these control parameters. Afterwards, a multiple regression model is developed to identify the parametric relevance of vs, fz, and ap, with surface roughness (SR) as the response attribute. A residual analysis is performed to validate the statistical adequacy of the predicted model. Lastly, the surface roughness regression model is considered as the objective function of the particle swarm optimization (PSO) model to minimize the surface roughness of the machined parts. The optimized SR results are compared to the widely employed genetic algorithm (GA) and RSM-based desirability function approach (DF). The confirmatory machining tests proved that the integrated optimization approach with PSO being an evolutionary technique is more effective compared to GA and DF with respect to accuracy (0.05% error), adequacy, and processing time (3.19 min). Furthermore, the study reveals that the Mecagreen 450 biodegradable oil-enriched flooded strategy has significantly improved the milling of Inconel 718 in terms of eco-sustainability and productivity, i.e., 42.9% cost reduction in cutting fluid consumption and 73.5% improvement in surface quality compared to the traditional flooded approach and the dry green approach. Moreover, the G-RSM-EO approach presents a sustainable alternative by achieving a Ra of 0.3942 μm that is finer than a post-finishing operation used to produce close tolerance reliable components for aerospace industry
Mathematical Models in Humanitarian Supply Chain Management: A Systematic Literature Review
In the past decade the humanitarian supply chain (HSC) has attracted the attention of researchers due to the increasing frequency of disasters. The uncertainty in time, location, and severity of disaster during predisaster phase and poor conditions of available infrastructure during postdisaster phase make HSC operations difficult to handle. In order to overcome the difficulties during these phases, we need to assure that HSC operations are designed in an efficient manner to minimize human and economic losses. In the recent times, several mathematical optimization techniques and algorithms have been developed to increase the efficiency of HSC operations. These techniques and algorithms developed for the field of HSC motivate the need of a systematic literature review. Owing to the importance of mathematical modelling techniques, this paper presents the review of the mathematical contributions made in the last decade in the field of HSC. A systematic literature review methodology is used for this paper due to its transparent procedure. There are two objectives of this study: the first one is to conduct an up-to-date survey of mathematical models developed in HSC area and the second one is to highlight the potential research areas which require attention of the researchers
Supply Chain Operations Management in Pandemics: A State-of-the-Art Review Inspired by COVID-19
Pandemics cause chaotic situations in supply chains (SC) around the globe, which can lead towards survivability challenges. The ongoing COVID-19 pandemic is an unprecedented humanitarian crisis that has severely affected global business dynamics. Similar vulnerabilities have been caused by other outbreaks in the past. In these terms, prevention strategies against propagating disruptions require vigilant goal conceptualization and roadmaps. In this respect, there is a need to explore supply chain operation management strategies to overcome the challenges that emerge due to COVID-19-like situations. Therefore, this review is aimed at exploring such challenges and developing strategies for sustainability, and viability perspectives for SCs, through a structured literature review (SLR) approach. Moreover, this study investigated the impacts of previous epidemic outbreaks on SCs, to identify the research objectives, methodological approaches, and implications for SCs. The study also explored the impacts of epidemic outbreaks on the business environment, in terms of effective resource allocation, supply and demand disruptions, and transportation network optimization, through operations management techniques. Furthermore, this article structured a framework that emphasizes the integration of Industry 4.0 technologies, resilience strategies, and sustainability to overcome SC challenges during pandemics. Finally, future research avenues were identified by including a research agenda for experts and practitioners to develop new pathways to get out of the crisis.</jats:p
Hajdu cheney syndrome due to NOTCH2 defect - First case report from Pakistan and review of literature
Introduction and importance: Hajdu Cheney Syndrome (HCS) is a rare skeletal disease characterized by severe, progressive focal bone loss with osteoporosis, variable craniofacial, vertebral anomalies and distinctive facial features. It is inherited as an autosomal dominant disease although sporadic cases have been described in literature. Identifying these cases in clinical practice is important for proper diagnosis and management.Case presentation: We report a case of a 36-year-old male patient presented at metabolic bone disease clinic at the Aga Khan University Hospital with history of multiple fragility fractures and juvenile osteoporosis since childhood. DNA sequence analysis of the NOTCH2 coding sequence revealed a pathogenic variant in NOTCH 2, Exon 34, c.6426_6427insTT (p.Glu2143Leufs*5), consistent with a NOTCH2 related conditions including HCS.Clinical discussion: The multitude of presentations associated with HCS are linked to the NOTCH2 gene, as Notch signaling is one of the core signaling pathways that control embryonic development. Hence, mutations in the Notch signaling pathway cause developmental phenotypes that affect various organs including the liver, skeleton, heart, eye, face, kidney, and vasculature.Conclusion: To the best of our knowledge, nucleotide mutations of c.6933delT, c.6854delA, c.6787C.T, and c.6424-6427delTCTG were all determined to be novel, with c.6428T \u3e C being the most common mutation found in literature. The c.6426_6427insTT mutation our patient was found to have via gene sequencing too appears to be a novel mutation, which has not previously been reported in literature
Developing resilience in disaster relief operations management through lean transformation
The impact of disasters in terms of the loss of human lives, infrastructure, and economy has been increasing over time. Planning and management strategies for disaster relief operations (DROs) have got the attention of researchers and policymakers, particularly on how to achieve resilience in such operations. This research aims to investigate the use of the lean transformation approach, which in this context is the process of evaluating relief operations’ performance in terms of responsiveness and road mapping interventions, for achieving resilience in DROs. A systematic lean-based method instigated through DROs’ management initiative was developed. This was validated through an empirical industrial fire case study where selected lean concepts and tools like Suppliers, Inputs, Process, Outputs and Customer (SIPOC)-analysis, value stream maps (VSM), key performance indicators (KPIs), fishbone diagram, and plan-do-check-act (PDCA) were used to investigate DROs resilience in terms of their responsiveness. The VSMs were developed for ‘as-is’ and ‘to-be’ scenarios, and comparative analysis against standardized KPIs was carried out. The lean transformation approach was found effective in the studied case of industrial fire for developing resilience in DROs. Furthermore, lean tools could help in devising pragmatic strategies to prevent delays and achieve enhanced resilience through better coordination, communication, capacity building, and awareness. This research contributes to the operations management and disaster management fields through lean transformation
COVID-19 challenges : can industry 4.0 technologies help with business continuity?
The COVID-19 pandemic has halted economic activities and made business dynamics much more challenging by introducing several additional operational, structural, and managerial constraints. The problem has affected global supply chains in many ways, and has questioned their long-term continuity. On the other hand, Industry 4.0 is an emerging phenomenon. However, there is a need to investigate how Industry 4.0 technologies may play a potential role in sustaining business operations to ease unprecedented causalities. The current research aims to investigate the potentiality of Industry 4.0 technologies to solve the COVID-19 challenges for long term sustainability. From an exploratory literature analysis coupled with the Delphi method, keeping in view the situation of the pandemic, ten challenge groups that have affected global business dynamics were identified. A questionnaire was developed with the aim of accumulating industrial and academic experts to evaluate the degree of influence and interrelationship among the identified challenges. The Decision Making, Trial and Evaluation Laboratory (DEMATEL) approach was deployed to further analyze the challenges for the categorization of these into causes and effects, further prioritizing them for better decision making. The prioritized challenges from the list of causes were governmental policies and support, followed by real access to customers and a lack of infrastructure. Additionally, these challenges were further evaluated through the expert opinion of Industry 4.0 systems experts and strategic-level supply chain experts to potentially gauge the potency of Industry 4.0 technologies to solve COVID-19-induced challenges. The outcomes of this research (which used Delphi integrated with a DEMATEL approach) are expected to support businesses in formulating strategies with the aim of business continuity in combating future disruptions caused by COVID-19-like pandemics
Effect of Calcium Channel Blockers on Lower Urinary Tract Symptoms: A Systematic Review
Background. Numerous medications are known to be associated with the development of lower urinary tract symptoms (LUTS).
One such medication group is calcium channel blockers (CCB). Objective. To critically examine the literature regarding the
involvement of CCB in manifestation of LUTS in humans. Methods. A systematic literature search was conducted on PubMed,
SciELO, Scopus, and OpenGrey databases to find all potentially relevant research studies before August 2016. Results. Five studies
met the inclusion criteria and were included in this review. Three out of five studies stated that CCB were involved in either
precipitation or exacerbation of LUTS. As for the remaining two studies, one study found out that only the monotherapy of CCB
was associated with increased prevalence of nocturia and voiding symptoms in young females, whereas the other study reported
an inverse association of CCB with LUTS. The methodological quality of studies was considered high for four studies and low for
one study. Conclusion. Healthcare providers should make efforts for an earlier identification of the individuals at risk of LUTS prior
to the commencement of CCB therapy. Moreover, patients should be counselled to notify their healthcare provider if they notice
urinary symptoms after the initiation of CCB
Engagement of private healthcare providers for case finding of tuberculosis and diabetes mellitus in Pakistan
Background: The rising co-epidemic of tuberculosis (TB) and diabetes mellitus (DM) is a challenge for constrained health systems in low and middle-income countries. Diabetes is a known risk factor for tuberculosis and associated with poor tuberculosis treatment outcomes, while tuberculosis is associated with worsening glycemic control. We investigated the performance of bi-directional TB and DM case finding approaches through a private-sector engagement model in Karachi, Pakistan.Methods: Between July 2016 and July 2018, private health care providers were engaged to generate referrals for bi-directional TB and DM screening at private diagnostic and treatment centers in Karachi, Pakistan. Individuals diagnosed with TB underwent glycated hemoglobin (HbA1c) testing at the time of anti-tuberculous treatment initiation and at three -month follow up stage. All individuals with a history of diabetes or random blood sugar of greater than 200 mg/dl were screened for TB using a chest X-ray and Xpert MTB/RIF.Results: A total of 6312 persons with tuberculosis were tested on HbA1c at treatment initiation, of whom 1516 (24%) were newly diagnosed with DM. About one third of those with HbA1c in the diabetic range (≥ 6.5%) at baseline were found to have a normal HbA1c (\u3c 5.7%) result at 3-month follow-up. A total of 3824 individuals with DM, of whom 2396 (63%) were known cases and 1428 (37%) were newly identified with random blood sugar \u3e 200 mg/dl, underwent chest x-ray and Xpert MTB/RIF testing, with 321 (13.4%) known and 54 (3.8%) new diabetics respectively identified with tuberculosis.Conclusion: This study demonstrates a high yield of TB and DM through bidirectional screening and the feasibility of engagement of private sector in finding missing cases of tuberculosis and diabetes. Given the high prevalence of undiagnosed DM in individuals with TB tuberculosis patients, there is a need to scale-up DM screening within TB programmes. Increased awareness of the high risk of TB among individuals with DM is needed among private health providers and screening for TB among diabetics should be strongly considered
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