Soheil Zeraati-Rezaei, Yasser Al-Qahtani, Hongming Xu,
Blend of diesel and gasoline (Dieseline) has been proven useful to improving premixed compression ignition (PCI) combustion but it is associated with combustion instability at low load conditions. In this study, a new strategy is developed using high rate of hot-EGR and lower injection pressure for the combustion control. The viability and benefits of PCI using the new strategy are evaluated with the low cetane-number (<30) and wide boiling range G75-Dieseline (a blend of 75% gasoline in diesel based ...
Tópico(s): Vehicle emissions and performance
2017 - Elsevier BV | Fuel
Soheil Zeraati-Rezaei, Yasser Al-Qahtani, J.M. Herreros, Xiao Ma, Hongming Xu,
Achieving low-smoke and low-NOx premixed compression ignition (PCI) combustion at a wide engine operating load range has been a challenge; especially in multi-cylinder engines running at higher loads for which less data is available in the literature. More specifically, it is of interest to characterise particle emissions under these conditions and identify their possible reduction benefit in different size classes compared to conventional diesel combustion. Mixing diesel with gasoline (Dieseline) ...
Tópico(s): Combustion and flame dynamics
2019 - Elsevier BV | Fuel
Sumit Maharjan, Yasser Al Qahtani, William L. Roberts, Ayman M. Elbaz,
Tópico(s): Combustion and flame dynamics
2018 - | SAE technical papers on CD-ROM/SAE technical paper series
Alhanoof Aldegheishem, Rasha Alharthi, Yasser M. Al-Qahtani, Mai Soliman, Marwa Salah Mostafa, Syed Fareed Mohsin, Elzahraa Eldwakhly,
This study aimed to evaluate the mechanical (i.e., flexural modulus [FM], flexural strength [FS], and surface roughness [Ra]) and antibacterial efficacy of photo-sonodynamic therapy via methylene blue-loaded poly(D,L-lactide-co-glycolide) nanoparticles (MB-loaded PLGA NPs) over dental implants for potential treatment of peri-implantitis.PLGA NPs were synthesized via a solvent displacement method. After the synthesis and confirmation of MB-loaded PLGA NPs via physical (Scanning Electron Microscope [SEM]) ...
Tópico(s): Laser Applications in Dentistry and Medicine
2022 - Elsevier BV | Photodiagnosis and Photodynamic Therapy
Tópico(s): Dental Research and COVID-19
2020 - Elsevier BV | Photodiagnosis and Photodynamic Therapy
Hatsari Mitsudharmadi, Sumit Maharjan, Ayman M. Elbaz, Yasser Al Qahtani, William L. Roberts,
Pre-ignition is an abnormal combustion event that may occur in boosted direct injection gasoline engines, where one or more auto-ignition events are observed before spark ignition. Due to the direct injection of fuel into the cylinder, some liquid fuel may splash off the walls, pulling lubricating oil with it. The auto-ignition of liquid fuel/lubricant droplets is considered as one of the possible sources of pre-ignition. To assess this stochastic phenomenon in a controlled way, the auto-ignition ...
Tópico(s): Combustion and Detonation Processes
2019 - American Chemical Society | Energy & Fuels
Mahmoud H. El-Komy, Riyadh M. Al-Qahtani, Yasser E. Ibrahim, Ali Almasrahi, M. A. Al-Saleh,
Tópico(s): Plant Disease Management Techniques
2022 - Springer Science+Business Media | European Journal of Plant Pathology
Sulaiman A. Alrumman, Yasser S. Mostafa, Shekha T. S. Al-Qahtani, Tarek H. Taha,
Abstract Hydrolytic enzyme production by thermophilic bacteria isolated from hot springs in the southern region of Saudi Arabia was investigated. The physical and chemical properties of the hot springs prove to be an important environment for hydrolytic-enzyme-producing thermophilic bacteria. Eighty-four bacterial isolates were obtained from three hot springs: Al-Majardah, Al-Khubah and Al-Ardah. Screening of the isolates for enzyme production indicated that 78 isolates showed activity for one or ...
Tópico(s): Protein Hydrolysis and Bioactive Peptides
2018 - De Gruyter Open | Open Life Sciences
Sulaiman A. Alrumman, Yasser S. Mostafa, Shekha T. S. Al-Qahtani, Taher Sahlabji, Tarek H. Taha,
Tópico(s): Pharmaceutical and Antibiotic Environmental Impacts
2018 - Springer Science+Business Media | Arabian Journal for Science and Engineering
Soheil Zeraati-Rezaei, Yasser Al-Qahtani, J.M. Herreros, Hongming Xu,
Premixed compression ignition (PCI) combustion techniques utilising low cetane-number (<40) fuels are associated with low engine-out oxides of nitrogen (NOx) and soot emissions. However, fuel-air over-mixing and high combustion noise at low and high engine loads, respectively, have been the challenges with PCI. Fuel split-injection can effectively govern the fuel-air mixing process and subsequently control combustion and emissions characteristics; it is of interest to characterise particle emissions ...
Tópico(s): Vehicle emissions and performance
2020 - Elsevier BV | Applied Energy
Shoeb Gamal Saleh, Rommel AlAli, Yousef Wardat, Mohammed Al-Qahtani, Yasser Soliman, Mamdouh Mosaad Helali,
The widespread adoption and expansion of distance learning necessitates the consideration of issues related to learning passion, which is the strong desire of learners towards a specific activity of high value and meaning that enables the use of relevant cognitive and behavioral strategies to acquire, store, apply, share, use, absorb, and create knowledge. The current study aimed to measure learners' practices of learning emotion processes, knowledge management, and organization in distance learning ...
Tópico(s): Emotional Intelligence and Performance
2023 - Multidisciplinary Digital Publishing Institute | European Journal of Investigation in Health Psychology and Education
Mutahir A. Tunio, Mushabbab AlAsiri, Khalid Al‐Qahtani, Yasser Bayoumi, Sadeq Al‐Dandan, Khalid Riaz,
Skull base metastasis from differentiated thyroid carcinoma, including papillary and follicular thyroid carcinoma, is a rare manifestation. Herein, we present three cases of skull base metastasis of papillary thyroid carcinoma. The mean age of the patients was 68.6 (65-74) years, and the mean interval between initial diagnosis and skull base metastasis was 56.3 (28-89) months. Cranial nerve palsies were seen in all patients. Intensity modulated radiation therapy to deliver 6,000-6,600 cGy to the skull ...
Tópico(s): Bone Tumor Diagnosis and Treatments
2015 - Dove Medical Press | International Medical Case Reports Journal
Balaji Mohan, Abdullah S. AlRamadan, Yasser Al-Qahtani, Yoann Viollet, Jihad Badra,
In this study, we have developed an in-house design of experiments (DoE) and machine learning (ML) based optimization framework for the engine calibration process. The new framework was compared to the traditional "one factor at a time" (OFAT) calibration process. The calibration process was carried out in a single-cylinder research engine for 7 bar indicated mean effective pressure (IMEP) at 1500 rpm. The engine control parameters such as the rail pressure, exhaust gas recirculation (EGR), start, and ...
Tópico(s): Refrigeration and Air Conditioning Technologies
2022 - Elsevier BV | Fuel
Khalid Al‐Qahtani, Mutahir A. Tunio, Yasser Bayoumi, Venkada Manickam Gurusamy, Fahad Ahmed A. Bahamdain, Hanadi Fatani,
Salivary ductal carcinoma (SDC) of parotid gland is a rare and aggressive entity; accounting for 1-3 % of all malignant salivary gland tumors, 0.2 % of epithelial salivary gland neoplasms, 0.5 % of salivary gland carcinomas, and 1.1 % of parotid gland carcinomas. Here in we aimed to evaluate the clinico-pathological features and treatment outcomes of parotid gland SDC in Saudi population.Among 38 patients with parotid malignancies, who were treated in two major tertiary care referral cancer centers between ...
Tópico(s): Oral and Maxillofacial Pathology
2016 - BioMed Central | Journal of Otolaryngology - Head and Neck Surgery
Mutahir A. Tunio, Khalid Al‐Qahtani, Mushabbab Al Asiri, Yasser Bayoumi, Ali Abdullah O Balbaid, Naji J. Aljohani, Hanadi Fatani,
Introduction: The aim of this study was to evaluate the treatment outcomes of differentiated thyroid cancer in Saudi patients aged above 60 years. Materials and methods: Comparative analysis was performed in 252 patients aged 46–60 years (Group A) and 118 patients aged above 60 years (Group B), who had thyroidectomy, radioactive iodine-131, and thyroid-stimulating hormone suppression therapy between July 2000 and December 2012. Different clinicopathological features, treatment, complications, disease- ...
Tópico(s): Thyroid Disorders and Treatments
2016 - Dove Medical Press | Clinical Interventions in Aging
Hina Gull, Saqib Saeed, Sardar Zafar Iqbal, Yasser A. Bamarouf, Mohammed Alqahtani, Dina A. Alabbad, Madeeha Saqib, Saeed Hussein Al Qahtani, Albandary Alamer,
Digital transformation of businesses has seen tremendous growth recently, moreover, COVID-19 has increased online shopping. However, it is important for businesses that customers’ online shopping experience is secure and joyful. In this paper, customers’ security perception regarding some leading mobile commerce applications in Saudi Arabia is explored. Our survey questions focused on three aspects, namely: Consumer rating, trustworthiness, and credit card security. The results highlight that consumers ...
Tópico(s): Organizational and Employee Performance
2022 - Multidisciplinary Digital Publishing Institute | Electronics
Yasser Elghoneimy, Abdulaziz Al Qahtani, Sultan A Almontasheri, Yousef Tawhari, Mohammed M. Alshehri, Abdulaziz H Alshahrani, Saad Almashi,
Introduction Acute kidney injury (AKI) is considered one of the serious complications in the medical field. It has a large impact on patients' life medically, socially and economically. It also has a financial burden on governments and hospitals regardless of which part of the world is considered. On the other hand, AKI is a common complication of cardiac surgery, which alone has a tremendous burden and implications on patients and governments. In this study, we will discuss the various risk factors, ...
Tópico(s): Chronic Kidney Disease and Diabetes
2020 - Cureus, Inc. | Cureus
Hanan Alsunbul, Aftab Ahmed Khan, Yasser M. Al-Qahtani, Saeed Awod Bin Hassan, Waleed Asiri, Selma A. Saadaldin, Rasha Alharthi, Alhanoof Aldegheishem,
This laboratory experiment was conducted with the objective of augmenting the mechanical properties of glass ionomer cement (GIC) via altering the composition of GIC luting powder through the introduction of micron-sized silanized glass fibres (GFs). Experimental GICs were prepared through the addition of two concentrations of GFs (0.5% and 1.0% by weight) to the powder of commercially available GIC luting materials. The effect of GF in set GIC was internally evaluated using micro-CT while the mechanical ...
Tópico(s): Endodontics and Root Canal Treatments
2023 - Multidisciplinary Digital Publishing Institute | Journal of Functional Biomaterials
Yasser M. Al-Qahtani, Mohammed I Al-Shehri,
The current study aimed to assess and compare the effectiveness of photosensitizers rose Bengal (RB), riboflavin, and curcumin (CP) to the conventional canal disinfection regime sodium hypochlorite (NaOCl) on the bonding interface of a fiber post cementation system.Sixty nontraumatic, extracted, and closed apex human mandibular second premolars were gathered and disinfected. All specimens were decoronated and embedded perpendicularly in heat cure acrylic resin. Shaping and cleaning of the canal were ...
Tópico(s): Dental Research and COVID-19
2022 - Jaypee Brothers | The Journal of Contemporary Dental Practice
Mutahir A. Tunio, Khalid Al‐Qahtani, Mushabbab AlAsiri, Naji J. Aljohani, Yasser Bayoumi, Iqbal Munir, Ayman Al-Ayoubi,
Radioactive iodine 131 ((131)I) therapy has long been used in the treatment of differentiated thyroid cancers (DTC). While salivary and lacrimal glandular complications secondary to (131)I therapy are well documented, there is little in the literature addressing nasolacrimal duct obstruction (NLDO). We aimed to evaluate the frequency of (131)I therapy-acquired NLDO, its correlation to (131)I therapy doses, and the surgical treatment outcome of this rare side effect.From 2000-2012, a retrospective review ...
Tópico(s): Thyroid Cancer Diagnosis and Treatment
2014 - Dove Medical Press | Clinical ophthalmology
Muhammad Mohsin Fareed, Abdullah Al Amro, Yasser Bayoumi, Khalid Al‐Qahtani, Hanadi Fatani, Mutahar Ali Tunio, Farhan Khalid,
We report a rare case of three head and neck malignancies in one patient. Squamous cell carcinoma of tongue and papillary thyroid carcinoma occurred as metachronous cancers in a patient with primary nasopharyngeal carcinoma. These three pathologically distinct malignancies of head and neck region in one patient is a rare phenomenon and is not reported so far. A 60 year old Saudi female patient presented in March 2011 with locally advanced nasopharyngeal carcinoma. After completion of concurrent ...
Tópico(s): Head and Neck Cancer Studies
2013 - BioMed Central | BMC Research Notes
Ayman Al‐Jazaeri, Mohammed Zamakhshary, Abdulrahma Al-Omair, Yasser Al-Haddab, Othman Jarallah Al Jarallah, Raied Al-Qahtani,
Seating position in motor vehicle collisions (MVC) plays a major role in determining the injury pattern in mainly restrained children. However, compliance with child seating and restraint laws is still suboptimal. The role of seating position in predicting injury patterns among unrestrained children has not been previously studied.
Tópico(s): Trauma and Emergency Care Studies
2012 - King Faisal Specialist Hospital and Research Centre | Annals of Saudi Medicine
Ahmad Marzouk Maklad, Yasser Bayoumi, Mohamed Abdalazez Senosy Hassan, AbuSaleh A. Elawadi, Hussain AlHussain, Ashraf Elyamany, Saleh Aldhahri, Khalid Al‐Qahtani, Mubarak Shaie Alqahtani, Mutahir A. Tunio,
... in Saudi Arabia Ahmed Marzouk Maklad,1,2 Yasser Bayoumi,2,3 Mohamed Abdalazez Senosy Hassan,2,4 AbuSaleh A Elawadi,5,6 Hussain AlHussain,2 Ashraf Elyamany,7,8 Saleh F Aldhahri,9 Khalid Hussain Al-Qahtani,10 Mubarak AlQahtani,11 Mutahir A Tunio12 1Clinical ...
Tópico(s): Lung Cancer Diagnosis and Treatment
2016 - Dove Medical Press | OncoTargets and Therapy
Salhah D. Al‐Qahtani, Yasser A. Attia, Ghadah M. Al‐Senani,
Tópico(s): Color Science and Applications
2024 - Elsevier BV | Ceramics International
Khalid Al‐Qahtani, Mushabbab Al Asiri, Mutahir A. Tunio, Naji J. Aljohani, Yasser Bayoumi, Hanadi Fatani, Abdulrehman AlHadab,
Papillary Microcarcinoma (PMC) of thyroid is a rare type of differentiated thyroid cancer (DTC), which according to the World Health Organization measures 1.0 cm or less. The gold standard of treatment of PMC is still controversy. Our aim was to contribute in resolving the debate on the therapeutic choices of the surgical and adjuvant I-131 (RAI) treatment in PMC.From 2000 to 2012, 326 patients were found to have PMC and were retrospectively reviewed for clinicopathological characteristics, treatment ...
Tópico(s): Head and Neck Anomalies
2015 - BioMed Central | Journal of Otolaryngology - Head and Neck Surgery
Shaimaa Abd-Elrahman, Yasser A. El–Gabry, Fadl A. Hashem, Mohamed F. M. Ibrahim, Ehab I. El‐Hallous, Zahid Khorshid Abbas, Doaa Bahaa Eldin Darwish, Nadi Awad Al‐Harbi, Salem Mesfir Al‐Qahtani, Noura Taha,
Under sandy soil conditions, increasing the efficiency of potassium (K) fertilizers is considered to be a major limiting factor for improving the productivity and quality of fruit crops. In this context, utilizing nanotechnology has emerged as a novel technique to increase the efficiency of K applications. In our study, two field trials were conducted, in two consecutive seasons (2019/2020 and 2020/2021), to compare the effects of nano-chitosan loaded with K as a foliar treatment with those of conventional ...
Tópico(s): Berry genetics and cultivation research
2023 - Multidisciplinary Digital Publishing Institute | Agronomy
Khalid Al‐Qahtani, Mutahir A. Tunio, Mushabbab Al Asiri, Naji J. Aljohani, Yasser Bayoumi, Khalid Riaz, Wafa AlShakweer,
Age is an important prognostic factor in differentiated thyroid cancer (DTC). Our aim was to evaluate differences in clinicopathological features and treatment outcomes among children and adult patients with DTC.We studied 27 children (below 18 years) with DTC treated during the period 2000-2012 and were compared with (a) 78 adults aged 19-25 years and (b) 52 adults aged 26-30 years treated during the same period in terms of their clinicopathological features and long term treatment outcomes. Locoregional ...
Tópico(s): BRCA gene mutations in cancer
2015 - BioMed Central | Journal of Otolaryngology - Head and Neck Surgery
Yasser Al Qahtani, Mark Sellnau, Xin Yu,
<div class="section abstract"><div class="htmlview paragraph">Diesel engines are largely used as power units with high fuel efficiency. Conversely, they have an adverse impact on the environment and human health as they emit high NOx and particulate matter emissions. As more stringent regulations for emissions are introduced, low temperature combustion strategy such as Gasoline Compression Ignition evolved and demonstrated the potential to reduce the particulate matter and NOx emissions ...
Tópico(s): Biodiesel Production and Applications
2024 - | SAE technical papers on CD-ROM/SAE technical paper series
Yasser Al Qahtani, R. Vallinayagam, Yoann Viollet, Abdullah Alhajhouje, Emre Cenker, Abdullah S. AlRamadan,
<div class="section abstract"><div class="htmlview paragraph">Our research group developed Gasoline Compression Ignition (GCI) fuel matrix based on the fuel properties, specifications and fuel sources in an effort to standardize the GCI fuel. This study attempts to experimentally validate the standardized GCI fuels to comply with the operational regimes of GCI engine. Two of the formulated GCI fuels (GCI7 and GCI8) with varying physical and chemical properties, and composition were investigated ...
Tópico(s): Catalytic Processes in Materials Science
2024 - | SAE technical papers on CD-ROM/SAE technical paper series
Mohammed S. Alqahtani, Adel Alhazzani, Ibrahim Alnaami, Saeed A. Alqahtani, Tariq Mohammed Alahmari, Abdulaziz M. Alqarni, Ibrahim Alburaidi, Mohammed A. Alqahtani, Saleh M. Al‐Qahtani, Moayad Abdullah Zarbh, Yasser wassel, Jaber Alfaifi, Ahmed Elhadad,
Objectives: To assess the epidemiological pattern and correlates with the clinical outcome of Cerebral venous thrombosis (CVT) in Abha, Kingdom of Saudi Arabia. Methods: A retrospective record-based cohort design was conducted including all patients admitted with diagnosis of CVT in 2 main tertiary hospitals in Aseer Region between 2015 to the end of 2018. The study hospitals were Aseer Central Hospital and Armed Forces Hospitals Southern Region. The data were collected by structured data sheets, including ...
Tópico(s): Venous Thromboembolism Diagnosis and Management
2020 - Riyadh Military Hospital | Neurosciences