1,016 research outputs found

    Production of Hard Grade Bitumen for Using in High Modulus Asphalt Concrete

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    قد تتعرض الخرسانة الاسفلتية الاعتيادية لعدة اضرار مثل شقوق الكلل والتخدد وتتفاقم درجة هذه الاضرار مع الظروف المناخية القاسية والحمل المروري المتكرر. يمكن اعتبار الخلطة الاسفلتية العالية المرونة المصممة وفقا للطريقة الفرنسية (EME)) أحد الحلول المهمة للحد من هذه الاضرار. ان انتاج هذا النوع من الخليط يتطلب اسفلت (كمادة رابطة) عالي الصلابة. البحث الحالي يتضمن طريقة جديدة لأنتاج الاسفلت بتدرج اختراق نوع hard)) ليلائم متطلبات الاسفلت العالي الصلابة المستخدم لأنتاج الخلطة الاسفلتية العالية المرونة المصممة وفقا للطريقة الفرنسية. العمل المختبري يتضمن خلط البوليمر ومصلبه مع الاسفلت الاعتيادي لأنتاج الاسفلت الجديد العالي الصلابة. نظرا لأن شقوق الكلل هي أكثر المخاوف المتعلقة بالأسفلت (كمادة رابطة) العالي الصلابة والخلطة الاسفلتية العالية المرونة، لذلك تمت إضافة حبيبات المطاط الى الاسفلت المنتج العالي الصلابة لتحسين أداء التبليط في مقاومة شقوق الكلل. تم اجراء اختباري مطياف الاشعة تحت الحمراء ومسح المجهر الالكتروني للأسفلت الاعتيادي وللأسفلت العالي الصلابة. كانت القيمة المثلى المختارة للمضافات لانتاج الاسفلت العالي الصلابة المستخدم في الخلطة الاسفلتية العالية المرونة هي 4% و0.4% من وزن الاسفلت للنوفولاك والهكسامين على التوالي، بينما نسبة حبيبات المطاط لتحسين المرونة هي 0.5%. أظهرت نتائج الاختبارات المجهرية والاشعة تحت الحمراء للاسفلت المنتج حدوث تداخلا ميكانيكيا بين الاسفلت والمضافات أدى الى تحسن كبير في الخواص الميكانيكة للاسفلت المنتج. الاسفلت المنتج قد حقق متطلبات الاسفلت العالي الصلابة وبالتالي يمكن استخدامه في انتاج الخلطة الاسفلتية العالية المرونة المصممة وفق الطريقة الفرنسية.The conventional Hot Mix Asphalt (HMA) may suffer from several distress such as fatigue cracks and rutting. These distresses increase with severe climate conditions and reputation of traffic load. The High Modulus Asphalt Concrete (HMAC) designed according to the French method (EME) can be considered as one of the important solutions for these distresses. The production of HMAC requires hard grade bitumen. The current research involved a novel way to produce hard grade bitumen (asphalt binder) to be consonant with the requirements of hard grade bitumen used for a HMAC. The experimental work involved mixing polymer and cross-linking agent with conventional bitumen to get the new bitumen. Since the most concern with hard grade bitumen and HMAC is the fatigue cracks, Crumb Rubber (CR) was added to the obtained bitumen to improve the fatigue performance of the pavement. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electronic Microscope (SEM) tests were carried out on the conventional and hard grade bitumen. The optimal value of additives was selected to meet the requirement of hard grade bitumen was 4% Novolac from weight of bitumen and 10 % of Hexamine from weight of Novolac (i.e. 0.4% of weight of bitumen), while the selected CR ratio to improve flexibility was 0.5% from weight of bitumen. FTIR and SEM test results showed that a mechanical interaction was occurring between the bitumen and the additives leads to greatly improve the mechanical properties of resulting bitumen. The obtained bitumen is satisfied to required standards and can be used for HMAC according to French method

    Experimental study for elastic deformation under isolated footing

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    The results of field studies of elastic deformations in the footing base, composed of loses soils. Elastic deformation is the result of compression partially bound water at the contacts between the mineral particles, the value of which depends on the wetness soil environment. It was found that deformation depends on the molecular moisture capacity of the soil while elastic settlement increases in proportion to pressur

    Phytochemical Characterization using GC-MS Analysis of Methanolic Extract of Moringa oleifera ( Family Moringaceae) Plant Cultivated in Iraq

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    Objective: The aim of the present study was to characterize the Moringa oleifera plant cultivated in Iraq for the presence of biologically active phyto-chemicals using methanolic extracts of the plant (leaves and seeds)  . This study was determined by using Gas Chromatography –Mass spectrometry, while the mass spectra of the compounds found in the extract was matched with the National Institute of Standards and Technology (NIST) library. Methods: In the present investigation, methanolic extracts of Moringa oleifera were screened for the presence of steroids, alkaloids, tannins, flavonoids, terpenoids, anthraquinoin and cardiac glycosides  by standard qualitative test procedures and further this study was extended by analyzing the potent bioactive compounds in the methanolic extract of plant using GC-MS analysis. Results:  reveal the presence of different compounds (about 100 compound)  in the Moringa plant extract  among them alkaloids, terpenoids  steroids, saturated and unsaturated fatty acid, aromatic and aliphatic hydrocarbon, polyphenolic compounds . GC-MS was done using the database of National Institute of standard and Technology (NIST). Conclusion: Results confirmed the presence of therapeutically potent compounds in the Moringa extract predominantly steroids, flavonoids and terpenoids. Keywords: Moringa oleifera, biologically active, Phytochemicals, GC-MS analysis

    ASSESSMENT OF VITAMIN D THERAPY EFFECT ON INFLAMMATORY MARKERS IN PEDIATRIC PATIENTS WITH TYPE I DIABETIC

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    Objective: The objective of this study is to estimate the effect of Vitamin D3 supplementation on endogenous Vitamin D3 level and inflammatory biomarkers in newly diagnosed pediatric patients.Methods: The patients were given oral Vitamin D3, and they divided into three groups: The first group (25 healthy pediatrics), the second group (25 newly diagnosed pediatric patients) treated with daily insulin regimen only, and the third group (25 newly diagnosed pediatric patients) treated with Vitamin D3 (2000 IU/day) with daily insulin regimen; all patients were treated for 90 days; and blood samples were taken at baseline and after 45 days and 90 days of starting Vitamin D3 to assess its potential effect on the levels of Vitamin D, serum calcium, serum alkaline phosphatase levels, and other inflammatory markers.Results: The results of the current study showed that serum IL-1β significantly declined in patients receiving Vitamin D3, while serum Vitamin D3, serum calcium, and interleukins-4 were significantly increased in patients receiving Vitamin D3.Conclusion: Vitamin D3 in a daily dose of 2000 IU/day for 90 days results in favorable immune response and increase of serum Vitamin D3 for pediatric new diagnosed Type 1 diabetes mellitus patients

    Comparison of Postoperative Drain Insertion versus No Drain Insertion in Thyroidectomies : Retrospective case-control study from the Sultan Qaboos University Hospital, Muscat, Oman

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    Objectives: A thyroidectomy is a frequently performed surgical procedure which can result in lifethreatening complications. The insertion of a drain after a thyroidectomy has been suggested to prevent such complications. This study aimed to evaluate the use of surgical drains following thyroidectomies in relation to postoperative complications and mass sizes. Methods: This retrospective case-control study included all thyroidectomies conducted at the Sultan Qaboos University Hospital, Muscat, Oman, from January 2011 to December 2013. Length of hospital stay, readmission, postoperative complications and mass size were evaluated. Results: During the study period, 250 surgeries were carried out on 241 patients. The majority of patients were female (87.2%). Drains were inserted postoperatively after 202 surgeries (80.8%) compared to 48 surgeries (19.2%) without drains. A total of 32 surgeries (12.8%) were conducted on patients with thyroid masses <1 cm, 138 (55.2%) on those with masses between 1–4 cm and 80 (32.0%) on those with masses >4 cm. The association between drain use and mass size was not significant (P = 0.439). Although postoperative complications were more prevalent in patients with drains, the relationship between these factors was not significant (P >0.050). Length of hospital stay was significantly longer among patients with postoperative drains (P <0.010). Conclusion: The routine insertion of drains after thyroid surgeries was found to result in longer hospital stays and did not reduce rates of postthyroidectomy complications. Thyroid mass size should not be used as an indicator for the insertion of a drain after thyroidectomy

    Missed Gastric Injuries in Blunt Abdominal Trauma : Case report with review of literature

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    Hollow viscus injuries of the digestive tract are an uncommon occurrence in blunt abdominal trauma. We report a 39-year-old male who was hit by a vehicle as a pedestrian and admitted to the Sultan Qaboos University Hospital, Muscat, Oman, in 2015. He underwent an exploratory laparotomy which revealed injuries to the distal stomach, liver and descending colon. Postoperatively, the patient was febrile, tachycardic and hypotensive. Abdominal examination revealed distention and tenderness. The next day, a repeat laparotomy identified a gastric injury which had not been diagnosed during the initial laparotomy. Although the defect was repaired, the patient subsequently died as a result of multiorgan failure. Missed gastric injuries are rare and are associated with a grave prognosis, particularly for trauma patients. Delays in diagnosis, in addition to associated injuries, contribute to a high mortality rate

    Effect of mixed and artificial feeding on the growth performance of Gattan Luciobarbus xanthopterus Heckel, 1843 larvae

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    This work aimed to study the rearing feasibility of Luciobarbus xanthopterus larvae using artificial and mixed (live (Chlorella sp.) + artificial) food and their effects on their growth performance during early development. Larvae (1.65 cm in length and 0.02 g weight) were obtained from a Marine Science Hatchery and cultured in indoor tanks for 35 days. the larvae fed mixed feed T1 and artificial feed T2 (fish meal + soybean meal). The results showed that the larvae of T1 treatment outperformed significantly in final length, final weight, final weight gain, daily and specific growth rate, which amounted to 3.44 cm, 0.3568 g, 0.3368 g, 0.0096 g/day, and 8.2185 % weight/day, respectively. Also, the results showed that larvae fed on T1 grew faster. The present study showed that applying a mixture of artificial and live food after four weeks' age i.e. after absorption of the yolk sac for feeding larvae can reduce the costs of producing and providing better growth and survival rates

    Characterizing the properties of sustainable semi-flexible pavement produced with polymer modified bitumen

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    Semi-Flexible Pavement (SFP) is a composite type of pavement produced by manufacturing of porous asphalt mixes using open graded aggregate gradation to create 20-35% of voids filled with grout (cement paste, cement mortar, etc.….). The resulting pavement has the flexibility of asphalt pavement and some strength of concrete pavement. The current study focused on investigation of using widely available (in Iraq) waste material namely Rice Husk Ash (RHA) to replace the Ordinary Portland Cement (OPC) partially in grout, also, using Polymer Modified Bitumen (PMB) to develop Open-Graded Asphalt (OGA) pavement without using cellulous fibre. The study focused on assessment of mechanical properties of the obtained SFP mixes with and without PMB. The results of study showed that using of PMB increased the Marshall Stability up to 100% and indirect tensile strength up to 50%. The Marshall Retained Stability gave about 90% which is quite higher the minimum required limit (70%). The results also revealed that RHA can be used as replacement for the OPC in SFP mixes. All investigated percentages showed satisfactory mechanical properties

    Paper Review: Flutter Phenomenon in Aero-Elasticity

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    Flutter is aero-elasticity phenomenon concerning the analysis of the relationship among aerodynamic and elastic forces, aerodynamic forces (static-aeroelasticity). Inertia, elastic and aerodynamic forces (dynamic-aeroelasticity). Elastic forces and laws of control (aero-servo-elasticity). Modern airplane designs can be very versatile and this versatility of the airframe allows aero-elastic analysis an essential part of airplane construction and Procedures for validation. Torsional and wing flutter are the two major aero-elastic phenomena considering in airplane architecture. Hopf bifurcation is a instability case that happens when the torsional stiffness of the system is counteracted by static aerodynamic impact. Flutter is a fluctuating motion due to instability in aero-elastic influences defined by a continuous fluctuation of the system resulting from the interaction among the inertial, elastic and aerodynamic forces operating on the entire body. This article provides a better understanding for flutter phenomena and aero-elasticity issues that seek to offer readers an understanding of the topic

    Utilizing of shields factors for sedimentation movements and drainage channels at the middle of Iraq (as a case study)

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    The shields factor seems to be a non-dimensional quantity which is utilized to determine the commencement of sediments movement in channels. This study intends to analyze sediments movement in channels of drainage and irrigation in Iraq by utilizing these characteristics as a determinant, and to establish a suitable formula to describe this impact in estimating sediments discharge. Based on seasonal unpredictability of the data, the field and laboratory work was completed across a 36-month period from January 2015 to January 2018. The soil texture was silty sand with a little clay amount, and the specific gravity magnitudes of the soil specimens vary from 2.66-2.73. Furthermore, the Shields factor magnitudes (θ) for movement were greater comparison with the critical magnitudes (θcr) in all channels; sediments transmission has been situated along the channels, according to the research. Using the Shields factor, two logarithmic formulas have been devised to quantify sediments discharge. The Flowing in irrigation channels has a correlation magnitude of 0.9007, whereas the Flowing in drainage channels has a correlation coefficient of 0.644. This demonstrated that the shields factor and sediments transport in irrigation channels had a significant degree of association. The drainage channels, on the other hand, have a significantly lower degree of correlation. This reflects the requirement to design a routine maintenance schedule for certain channels and to ensure that hydraulic Flowing criteria are met
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