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| 1 | Service life prediction of AP/Al/HTPB solid rocket propellant with consideration of softening aging behavior显示文摘The aging behavior of softening composite solid propellant was investigated by measuring its mechanical and ballistic prosperities during prolonged storage at elevated and room temperatures. Accelerated aging was conducted at 65 °C for 231 days while the normal aging was performed at 25 ± 3 °C and relative humidity less than 50% for 8 years. The mechanical properties were obtained from uniaxial tensile tests for the aged propellant specimens while the ballistic properties were determined from static firing tests of subscale motors aged for 112 days at 65 °C. The mechanical results show that the maximum tensile strength and Young's modulus initially increase and subsequently decrease with increasing aging time, while the maximum tensile strain generally increases with increasing aging time. The ballistic properties like burning rate show a small change which cannot affect the ballistic performance. The experimental results show that the changes in the mechanical properties are significant during the aging period, but the burning rate does not undergo significant changes. From this study, it is observed that the propellant ages through a combination of reactions like post-cure, oxidative cross-linking, chain scission, and hydrolysis. The chain scission and the hydrolysis effect are the most significant process, which makes the propellant soft and extendible. The observed aging mechanism has been modeled using an exponential function with two terms which can describe the complex behavior of the aging. By applying Arrhenius equation,the activation energy values were obtained based on the propellant mechanical properties. The shelf life of this propellant formulation at 25 °C is predicted to be 13 years using the modulus as failure criteria and control parameter. | Walid M.ADEL Guozhu LIANG | 2019 | Chinese Journal of Aeronautics2019，32，2： | 4 |
| 2 | Azadirachtin potentiates the action of ecdysteroid agonist RH-2485 in Spodoptera littoralis显示文摘 | MANAL M.ADEL FRANTISEK SEHNAL | | 0，，： | 1 |
| 3 | Chitosan/Nanocrystalline Cellulose Biocomposites Based on Date Palm (Phoenix Dactylifera L.) Sheath Fibers显示文摘In this study,nanocrystalline celluloses were used to enhance physical,mechanical and water vapor barrier properties of chitosan films for potential food packaging applications.Two different mineral acids(sulfuric and phosphoric)were used to extract nanocrystalline cellulose from date palm sheath fibers.The influence of cellulose I and cellulose II on the properties of the isolated nanocrystalline celluloses(e.g.,yield,energy and length of intra-and intermolecular hydrogen bonds,and degree of substitution)were studied too.The characteristics of chitosan biocomposite film with phosphorylated nanocrystalline cellulose were compared to those with sulfated nanocrystalline cellulose.Results showed that besides cellulose polymorphism,the ionic ester groups on the surface of nanocrystalline cellulose is one of the factors influencing the physical,chemical,mechanical,and water vapor barrier properties in chitosan/nanocrystalline cellulose biocomposites. | Abeer M.Adel Amira M.El-Shafei Atef A.Ibrahim Mona T.Al-Shemy | 2019 | Journal of Renewable Materials2019，7，6： | 0 |
| 4 | Feasibility and reliability of the revised Edmonton Symptom Assessment System(ESAS-r)in Egyptian patients with advanced cancer:A single institutional experience显示文摘Objective This study aims to test the acceptance, feasibility, and usefulness of the Arabic version of the revised Edmonton Symptom Assessment System(ESAS-r) among Egyptian patients with advanced cancer and to compare the rates of symptoms documented by patients and physicians. Methods Between August 2014 and February 2015, a total of 140 patients at Ain Shams University Hospitals in Cairo, Egypt received the Arabic version of the ESAS-r. For each patient, the ESAS-r was completed twice, first by the treating physician(as part of the basic assessment) and a second time by the patient, with a maximum of 2 hours between the two assessments. An additional survey was included to assess patients' acceptance of the survey and their preferences. Results Out of 140 enrolled patients in the study, 11 patients refused to complete the questionnaire, and 10 patients were excluded due to incomplete records in their medical records. Complete data was retrieved for 119 patients who were included for further analyses. The 78(65%) patients declared that the test was clear and easy to complete. They were able to answer the test without help. Collectively, tiredness and sense of well-being were the most commonly encountered symptoms in ratings obtained by both patients and physicians. Tiredness was the only symptom showing a significant difference between the two rating methods, patient-rated scores being higher(P = 0.032). Cronbach's alpha showed that both tests completed by the physician and the patients were internally consistent: the physician-rated test had a coefficient of 0.877, and the patient-rated test had a coefficient of 0.863. All ESAS scores had good internal consistency, with a Cronbach's alpha coefficient of 0.88. The internal consistency remained high after removal of individual symptom scores, with Cronbach's alpha coefficients ranging from 0.823 to 0.902, indicating that no individual question had undue influence on the total ESAS score.Conclusion The ESAS-r was easily understood by and applicable to patients. There was no significant discrepancy in the rates of symptoms reported by the patients and physicians, apart from tiredness. Based on this, the test could be applied on a larger scale with in-home patients. This test can be cost-effective and can decrease the number of hospital visits among advanced cancer patients in need of supportive treatment rather than active cancer therapy. | Dina A.Salem Azza M.Adel Ahmed E.Essa Mohamed O Alorabi Zeinab M.Elsayed | 2016 | Oncology and Translational Medicine2016，2，2： | 0 |
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