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Utilization of polyethylene waste for designing foamy oil sorbents
No full textRecycling low-density polyethylene (LDPE) in its original form presents several challenges, including limited interest from converters, poor market demand for recycled products, higher sorting and cleaning costs, and reduced quality in the final products. It happens because recycled LDPE often exhibits lower mechanical strength and diminished aesthetic appeal than its virgin counterpart, making it rarely suitable for its original purpose, especially in packaging. Therefore, new applications for LDPE recyclates are needed to overcome these barriers and extend the material’s lifecycle. One such solution involves converting LDPE waste into foamy sorbents for water purification. The presented study investigated two strategies for recycling LDPE waste by exploring the potential of the modified waste to remove free oil spills. The first approach involves preparing and characterizing robust, mechanically stable foams using recycled waste from LDPE packaging. The process is based on parallel foaming and crosslinking of LDPE by peroxides. The final foamy structure (Foam 1) possesses around 75 vol% of pores (46 vol% open pores) and rapidly absorbs various organic liquids quickly (hexane, diesel oil, crude oil) in multiple cycles. The second target deals with the screening, testing, and characterizing of LDPE-based foams that were initially used for various packaging and deposited as waste to explore their potential free oil sorbents. The foam that was used in this study has a significantly porous structure, having 96 vol% of pores and more than 89 vol% open pores (Foam 2). Whereas the sorption capacity of Foam 1 was 4–5 g/g, depending on the type of oil, Foam 2 absorbed those oils in the range of 8–12 g/g. The Foam 1 showed significantly better stability over multiple cycles and better mechanical performance.This research was made possible by a grant from the Qatar National Research Fund under its GSRA (GSRA9- L-1-0520-22027) Research Program.
The authors (M.M., M.I., and A.M.) gratefully acknowledge the Ministry of Education, Youth and Sports of the Czech Republic - DKRVO (RP/CPS/2024-28/003). Furthermore, author F.M. would like to gratefully acknowledge the project IGA of TBU in Zlín, reg. No. IGA/FT/2024/007 for financial support
Judicial Supervision of Arbitral Awards – A Comparative Study
No full textيهدف هذا البحث إلى بيان مدى إقرار القانون التحكيمي القطري رقم 2 لسنة 2017 بمهمة الرقابة التي يمارسها القضاء على القرارات التحكيمية، ومدى أخذه بالأحكام التي من شأنها أن تتلافى الآثار السلبية لتلك الرقابة.
وقد اتبعت الدراسة المنهج الاستقرائي للوقوف على الدور الذي ينيطه القانون القطري بالقضاء للرقابة على الحكم التحكيمي ضمن التحكيم الداخلي، مع تعزيز ذلك باعتماد المنهج المقارن لاستطلاع ثغرات القانون القطري في هذا المجال، واستلهام حلول القوانين المقارنة لسد تلك الثغرات.
وقد انتهت الدراسة إلى أنّه، حتى وإن كان قانون التحكيم يسمح للقاضي بمراقبة اختصاص الهيئة التحكيمية بالقدر الضروري للإبقاء على وظيفته كجهة رقابة على صحّة الأحكام التحكيمية، فإن تعديل بعض الثغرات يبقى ضروريا. ولذلك، يقترح البحث على المشرّع القطري الأخذ بتوصيات يمكن إجمالها في منح هيئة التحكيم حق التمديد في الأجل الاتفاقي باعتبار المحكمين هم الأقرب للنزاع والأقدر على معرفة ما يقتضيه من أعمال وأبحاث، وهم بالتالي الأقدر على تحديد الزمن الذي قد تستغرقه مهمتهم. ثم النص على مراقبة القضاء لالتزام الهيئة التحكيمية بإعطاء شرط مدة التحكيم الواردة في اتفاق التحكيم معنى ينسجم مع احترام المبادئ الإجرائية الأساسية، هو اتجاه إرادة الطرفين إلى الحصول في أسرع وقت ممكن، وفي أجل معقول بالنظر إلى طبيعة النزاع، على حكم تحكيمي قابل للتنفيذ يصدر بعد محاكمة عادلة. وبعد ذلك تعديل المادة 8 من قانون التحكيم باستبدال مصطلح «عدم قبول الدعوى»، بمصطلح «عدم الاختصاص»، والنص على أنّه لا يجوز للقضاء النظر في الدعوى التي تتعلّق باتفاق تحكيم أثاره أحد الأطراف قبل الخوض في الأصل، إلاّ إذا كان من البيّن للمحكمة أن اتفاق التحكيم باطل.This research paper aims to demonstrate the extent to which the Qatari arbitration law acknowledges the task of oversight exercised by the judiciary over arbitration decisions, and the extent to which it adopts provisions that would avoid the negative effects of that oversight. The study followed the inductive approach to determine the role that Qatari law assigns to the judiciary to monitor the arbitral award within internal arbitration, while enhancing this by adopting the comparative approach to explore the gaps in Qatari law in this field, and to draw inspiration from comparative law solutions to fill those gaps. The study concluded that, even if the arbitration law allows the judge to monitor arbitral tribunal competency to the necessary limit maintaining his function as a supervisory body over the validity of arbitral awards, amending some deficiencies remains necessary. Therefore, granting the arbitral tribunal the right to extend the agreed-upon period is predicated on the observation that arbitrators are closer to the dispute and better able to understand the work and research it requires. Therefore, they are in a better position to determine the time their task may take.Then, stipulating judicial oversight to ensure the arbitral tribunal respects the time con-dition stated in the arbitration agreement—interpreting it in a way that aligns with fun-damental procedural principles—reflects the parties’ intention to obtain an enforceable arbitral award as quickly as possible and within a reasonable time, considering the nature of the dispute, and following a fair trial.Lastly, we propose revising Article 8 of the Arbitration Law. This would involve replac-ing the term “inadmissibility of the claim” with “lack of jurisdiction.» Additionally, the law would state that courts could not consider a case related to an arbitration agreement unless it is clear that the agreement is invalid
Unlocking multimodality: E-scooters as first/last mile connectors and multimodal hub exploration in Doha
No full textOvercoming Doha's "first/last-mile" gap is critical if its new metro is to win riders in a car-oriented, hot-climate city. We therefore combined over 44,000 anonymised e-scooter GPS traces collected between December 2020 and August 2021 with hourly metro-gate counts and network-based walksheds around every station. Descriptive statistics, correlation tests and travel behaviour-centred user segmentation revealed how the two modes interact in space and time. Fifty-seven per cent of scooter trips began or ended within a short walk of a metro entrance, indicating significant spatial proximity between micromobility usage and transit infrastructure. Five distinct rider groups emerged: "frequent commuters" concentrate at central business-district stations, while "infrequent weekend riders" cluster at leisure destinations. Temporal analysis revealed strong integration potential across diverse station types: 8 out of 10 stations demonstrated temporal alignment between scooter activity and metro ridership, including business districts, cultural destinations, and residential areas. This alignment typically followed a logical pattern with ridership peaks, followed by scooter activity peaks consistent with multimodal trip-making. Only stations with minimal scooter activity showed patterns inconsistent with transit connectivity. These findings demonstrate that successful multimodal integration extends beyond business districts to include diverse urban contexts when supported by appropriate infrastructure. The Doha case shows that even in extreme heat climates, spatiotemporal analysis can guide effective micromobility policies that enhance both transit connectivity and broader urban accessibility.This publication was made possible by NPRP grant # [ NPRP13S-0130–200211] from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors
Advances in polyhydroxyalkanoate (PHA) production from renewable waste materials using halophilic microorganisms: A comprehensive review
No full textPolyhydroxyalkanoates (PHAs) are biodegradable and biocompatible polymers that can replace conventional plastics in different sectors. However, PHA commercialization is hampered due to their high production cost resulting from the use of high purity substrates, their low conversion into PHAs by using conventional microbial chassis and the high downstream processing cost. Taking these challenges into account, researchers are focusing on the use of waste by-products as alternative low-cost feedstocks for fast-growing and contamination-resistant halophilic microorganisms (Bacteria, Archaea…). This is of great importance since these extremophiles can use low-cost substrates, produce high PHA content of copolymers or different PHA monomer compositions. They can present high potential for reducing the costs of PHA fermentation and recovery processes, making their use in commercial applications easier. However, little is known about the potential of halophiles in advancing the PHA production from renewable waste materials at lab-scale and their successful implementation at industrial-scale. This review presents actual advances in PHA production by halophilic pure/engineered species (e.g. Haloferax mediterranei, Halomonas spp.) and mixed microbial consortia (MMC) using organic waste streams. The development of optimal PHA production process involves robust genetic engineering strategies, advanced fermentation processes using mixed microbial consortia versus pure/engineered strains as well as algal biomass as feedstocks.This paper was supported by Qatar University Internal Grants (No. QUCG-CAS-24/25-484). We also thank the reviewers for their helpful comments on this manuscript
Response to the letter to the editor regarding "evaluating artificial intelligence chatbots for patient education in oral and maxillofacial radiology".
No full textWe appreciate the opportunity to respond to a recent letter regarding our manuscript, "Evaluating Artificial Intelligence Chatbots for Patient Education in Oral and Maxillofacial Radiology." The authors’ engagement with our work highlights the growing importance of AI in healthcare communication, particularly in specialized fields like oral and maxillofacial radiology
Insects in agricultural greenhouses: a metagenomic analysis of microbes in Trialeurodes vaporariorum infesting tomato and cucumber crops
No full textIntroduction: With the predicted 9-10 billion world population increase by 2050 and its accompanying need for sustainable food production, and with the harsh climate conditions challenging agriculture and food security in many countries world-wide, employing "horticultural protected cultivation practices" in farming for seasonal and off-seasonal crop production is on the rise, among which is the use of agricultural greenhouses. The importance of greenhouse farming has been, indeed, evident by the perceived increase in year-round crops production, curtail in production risks, upsurge in agricultural profits, outreaching food stability and security in many countries globally. Yet, and despite this acknowledged success of employing greenhouses in farming, many constraints, including the presence of insect pests, still chaperoned this practice over the years, significantly impacting crop quality and production. Methods: As such, we assessed in this study the status of "insect pests" in the greenhouse model by collecting insects from different greenhouse sectors grown with tomatoes and cucumbers and identified the collected insects using relevant identification keys. To further explore the pest paradigm in greenhouses, we then focused on particularly studying Trialeurodes vaporariorum (TRIAVA), a key insect species among the collected and identified insects in the studied greenhouse model and a significant pest with an impactful effect on many crops worldwide. To do so, we traced the abundance of TRIAVA in the tomato and cucumber grown greenhouse sectors over the period of the study, analyzed its metagenome and associated its abundance with crop yield. Results and discussion: Our findings revealed TRIAVA hosted microbes with aptitudes to either serve as symbiotic microorganisms and protect TRIAVA against pathogens or to potentially cause damage to crops. This work provides additional insight into the insect pests paradigm in greenhouses, an upshot that could serve integrated insect pest management strategies in greenhouses for optimal agricultural practices.The author(s) declare that financial support was received for the research and/or publication of this article. This work was supported by the Ministry of Environment and Climate Change and the Ministry of Municipality/Doha Municipality (Insects and Rodents Control Section) in the State of Qatar, by Agrico Agricultural Development W.L.L., and by Qatar University Research Fund (QUST-1-CHS-2022_323) awarded to Layla Kamareddine. The authors also thank the Health Sector at Qatar University for funding the article processing charges and BGI for providing the sequencing platform and technical support. The graphical abstract of the study overview was created with BioRender.com .Scopu
Finite Element Analysis of Self Expanding Transcatheter Aortic Valves reveals Increased Stent contact Pressure is Associated with Higher Conduction Abnormality Risk
No full textFor transcatheter aortic valve implantation (TAVI), selecting optimal valve size and implantation depth within aortic root is crucial for preventing complications, such as conduction problems and paravalvular leak. Computational modeling offers comprehensive assessment of patient-specific TAVI scenarios at pre-operative stage enabling calculation of aortic wall mechanical stresses and deformations from the implanted valve. Here, our objective is to develop patient-specific finite element computational modeling approaches for comprehensive biomechanical assessment of TAVI to investigate correlations between post-TAVI aortic wall mechanics and post-TAVI complications. This investigation is in collaboration with Hamad Heart Hospital TAVI program in Qatar where Medtronic Core Valve is the most commonly used TAV, hence we focused on this valve type. A total of 54 retrospective cases were analyzed. Among the study cohort, 24 patients received 26mm valve, 23 patients received 29mm valve, and 7 patients received 34mm valve. ABAQUS finite element analysis (FEA) software was used for complete TAVI simulation operation. For each TAVI case, FEA revealed biomechanical stress and deformation patterns on aortic root. Studied parameters are average and maximum values of contact pressure, von mises stresses, and radial displacements. Studied cases were grouped into cases that experienced complications post-TAVI and cases that did not experience complications post-TAVI. Using ABAQUS, we successfully simulated complete TAVI implantation and carried out FEA for aortic root stress and deformation patterns for studied cases. Statistical analysis revealed that TAVI contact pressure was higher for cases suffering from conduction abnormalities, suggesting stent pressure is an important factor influencing conduction abnormalities experienced post-TAVI. FEA is a powerful approach for simulating TAVI and predicting possible post-TAVI complications, and advancing such models will enhance therapy planning for TAVI therapy.Qatar Research Development and Innovation Council
Qatar Universit
Monocyte-to-HDL ratio (MHR) as a novel biomarker: reference ranges and associations with inflammatory diseases and disease-specific mortality
No full textBackground: Monocyte-to-HDL Ratio (MHR) biomarker reflects monocyte-driven inflammation and HDL's anti-inflammatory properties. MHR's reference ranges and prognostic utility remain undefined. We establish normal MHR reference ranges and examine its association with inflammatory diseases and mortality. Methods: Using NHANES data (1999-2018, 2021-2023), two sets of sex-specific MHR reference ranges were generated using two healthy adult populations (monocyte count: 6,757; monocyte percentage: 6,817). Further analyses utilized MHR by monocyte count for more straightforward interpretation. Adjusted associations between MHR and inflammatory diseases were assessed in 49,929 adults, and disease-specific mortality in 35,781. Results: The 2.5th-97.5th percentiles for MHR by monocyte count were 0.175 (90% CI: 0.167-0.184) to 0.709 (90% CI: 0.690-0.727) in males and 0.135 (90% CI: 0.130-0.140) to 0.511 (90% CI: 0.503-0.520) in females, with similar trends for MHR by monocyte percentage. High MHR was most strongly associated with diabetes (aOR = 1.76, p < 0.001) and cardiovascular disease (aOR = 1.69, p < 0.001), while mortality risk was highest for kidney disease (aHR = 3.13, p < 0.001) and diabetes (aHR = 2.26, p < 0.001). Conclusion: MHR is a feasible and accessible biomarker of inflammation and lipid dysregulation that can be derived from routine laboratory tests and shows strong associations with cardiometabolic diseases and disease-related mortality.Scopu
Invisible inequities in type I diabetes care in India: A multi-stakeholder qualitative study from Karnataka
No full textType 1 Diabetes mellitus (T1DM) affects a substantial population in India, with significant challenges related to healthcare access and financial burden. This study aims to explore the multi-level barriers and enablers of T1DM care in Karnataka state, providing evidence-based recommendations for policymakers to improve healthcare services. This qualitative study employed in-depth interviews (IDIs) and focus group discussion (FGDs) with multiple stakeholders, including ten People with Type-1 Diabetes Mellitus (PwT1DM) aged 5–23 years and their caregivers, 13 Healthcare providers (HCPs) -Endocrinologists, paediatricians, diabetes educators, and primary care physicians; and ten senior health officials and six Policymakers. Participants were selected using purposive sampling from both urban and rural settings across Karnataka. Data was collected over six months, and qualitative research software was used to analyse the transcribed data thematically. The study was approved by the Institutional Ethical Committee of M.S. Ramaiah Medical College. Significant obstacles include inadequate integration of policies within India’s national framework, erratic insulin availability, substantial out-of-pocket costs, and insufficient training for healthcare providers. Rural demographics face compounded disadvantages due to poor healthcare infrastructure, while caregivers, especially mothers, struggle with financial and emotional burdens; People with TIDM endure social stigma and mental health issues, particularly affecting females. The study highlights the critical need for formulating dedicated T1DM policies within the framework of the existing NonCommunicable Disease program. Implementation of subsidized insulin schemes and expansion of primary care services, along with a multi-sectoral strategy, encompassing enhanced training for HCPs, integration of digital health solutions, and development of community-based support systems, is essential for effective and sustainable T1DM management. Addressing financial and gender-based disparities is crucial to ensure equitable care in both urban and rural areas
The impact of personality characteristics on the perceptions of youth in Qatar toward entrepreneurship: the moderating role of demographics
No full textThis paper aims to examine the impact of personality characteristics on the perceptions of youth in Qatar toward entrepreneurship. The research also attempts to test the moderating role of demographics in the links between these two variables. Using a self-administered questionnaire, 194 full-time university students participated in the study. Structural equation modeling was used to analyze the collected data. The results demonstrate that personality characteristics play significant roles in shaping the perceptions of youth toward entrepreneurship. Although all six personality components were found significant, the committed, leader and outgoing traits showed the strongest associations with youth perceptions of entrepreneurship. Moreover, the findings also reveal that demographic characteristics significantly moderate the association between personality attributes and the perception of entrepreneurship. This study offers insights to policymakers and educators to guide strategic planning that considers the influence of personality traits on entrepreneurship, with the goal of enhancing entrepreneurial activity and promoting socio-economic development. The implications of the results for both researchers and practitioners are also discussed in the paper.Open Access funding provided by the Qatar National Library.Scopu