Air lubrication by means of a bottom cavity is a promising method for ship drag reduction. The characteristics of the bottom cavity are sensitive to the flow field around the ship hull and the effect of drag reduction...Air lubrication by means of a bottom cavity is a promising method for ship drag reduction. The characteristics of the bottom cavity are sensitive to the flow field around the ship hull and the effect of drag reduction, especially the depth of the bottom cavity. In this study, a ship model experiment of a bulk carrier is conducted in a towing tank using the method of air layer drag reduction (ALDR) with different bottom cavity depths. The shape of the air layer is observed, and the changes in resistance are measured. The model experiments produce results of approximately 20% for the total drag reduction at the ship design speed for a 25-mm cavity continuously supplied with air at Cq = 0.224 in calm water, and the air layer covers the whole cavity when the air flow rate is suitable. In a regular head wave, the air layer is easily broken and reduces the drag reduction rate in short waves, particularly when λ/Lw1 is close to one;however, it still has a good drag reduction effect in the long waves.展开更多
Background: Major β-thalassemia occurs when impaired genes received by a neonate from the parents. In most of the parents, there are no apparent clinical manifestation and they just show some impairments in hematolog...Background: Major β-thalassemia occurs when impaired genes received by a neonate from the parents. In most of the parents, there are no apparent clinical manifestation and they just show some impairments in hematological indices. This study was designed to determine prevalence of minor and silent carries parents that have children suffering from major β-thalassemia, compare it with national protocol about prevention of thalassemia. Methods: A blood sample was taken from parents of all major thalassemic patients covered by TaleghaniHospitalin Gorgan (n = 195), CBC and Hemoglobin electrophoresis were done. Data were analyzed using SPSS software. Results: Amongst 196 parents one case have normal level of MCV, MCH, RBC, HbA, HbF and mentzer = 22.05 (0.51%) that diagnosed as alpha triplication/N by real time PCR, RFLP informative. The means of hematological indices were based on the national protocol. Conclusion: Present results showed that there are a few cases of thalassemia disorders with normal MCV, MCH, RBC, Mentzer index and Hb electrophoresis which could be missed in routine and pre-marital screening tests, resulted in a thalassemia child that it is possible in every screening test. Generally, indices were according to range of the national guideline.展开更多
为了解不同浓度有机干扰物对含氯消毒剂杀菌效果的影响,使用牛血清白蛋白作为有机干扰物,采用悬液定量和载体定量杀菌试验方法进行了实验室观察。结果,用含30 g/L牛血清白蛋白的菌悬液进行试验:有效氯为300 mg/L时可100%杀灭大肠杆菌,...为了解不同浓度有机干扰物对含氯消毒剂杀菌效果的影响,使用牛血清白蛋白作为有机干扰物,采用悬液定量和载体定量杀菌试验方法进行了实验室观察。结果,用含30 g/L牛血清白蛋白的菌悬液进行试验:有效氯为300 mg/L时可100%杀灭大肠杆菌,需要次氯酸钠溶液作用7.5 m in;三氯异氰尿酸钠片剂和二氯异氰尿酸钠粉剂作用15 m in;以含有效氯2500 mg/L的片剂和粉剂对枯草杆菌黑色变种芽孢作用30 m in,有效氯5000 mg/L次氯酸钠水溶液作用90 m in,杀灭率均达到100%。用含3 g/L牛血清白蛋白的菌悬液进行试验:以含有效氯50 mg/L作用7.5m in,3种剂型含氯消毒剂对大肠杆菌的杀灭率均可达100%。用含有效氯1000 mg/L的片剂和粉剂作用30m in;有效氯2000 mg/L的次氯酸钠水溶液作用60 m in,对枯草杆菌黑色变种芽孢杀灭率均可达100%。用载体法试验:以有效氯300 mg/L次氯酸钠溶液作用7.5 m in,杀灭大肠杆菌100%;以有效氯2000 mg/L次氯酸钠溶液作用60 m in,对枯草杆菌黑色变种芽孢杀灭率100%。结论,在高浓度有机干扰物条件下,含氯消毒剂片剂和粉剂杀灭细菌芽孢剂量明显高于液体制剂;在低浓度有机干扰物条件下,悬液法与载体法对含氯消毒剂杀菌试验结果基本一致。展开更多
基金supported by the Ministry of Industry and High Technology Marine Scientific Research Projects(Grant No.2011530)the High Performance Marine Technology Key Laboratory of the Ministry of Education Open Foundation(Grant No.2013033102)
文摘Air lubrication by means of a bottom cavity is a promising method for ship drag reduction. The characteristics of the bottom cavity are sensitive to the flow field around the ship hull and the effect of drag reduction, especially the depth of the bottom cavity. In this study, a ship model experiment of a bulk carrier is conducted in a towing tank using the method of air layer drag reduction (ALDR) with different bottom cavity depths. The shape of the air layer is observed, and the changes in resistance are measured. The model experiments produce results of approximately 20% for the total drag reduction at the ship design speed for a 25-mm cavity continuously supplied with air at Cq = 0.224 in calm water, and the air layer covers the whole cavity when the air flow rate is suitable. In a regular head wave, the air layer is easily broken and reduces the drag reduction rate in short waves, particularly when λ/Lw1 is close to one;however, it still has a good drag reduction effect in the long waves.
文摘Background: Major β-thalassemia occurs when impaired genes received by a neonate from the parents. In most of the parents, there are no apparent clinical manifestation and they just show some impairments in hematological indices. This study was designed to determine prevalence of minor and silent carries parents that have children suffering from major β-thalassemia, compare it with national protocol about prevention of thalassemia. Methods: A blood sample was taken from parents of all major thalassemic patients covered by TaleghaniHospitalin Gorgan (n = 195), CBC and Hemoglobin electrophoresis were done. Data were analyzed using SPSS software. Results: Amongst 196 parents one case have normal level of MCV, MCH, RBC, HbA, HbF and mentzer = 22.05 (0.51%) that diagnosed as alpha triplication/N by real time PCR, RFLP informative. The means of hematological indices were based on the national protocol. Conclusion: Present results showed that there are a few cases of thalassemia disorders with normal MCV, MCH, RBC, Mentzer index and Hb electrophoresis which could be missed in routine and pre-marital screening tests, resulted in a thalassemia child that it is possible in every screening test. Generally, indices were according to range of the national guideline.
文摘为了解不同浓度有机干扰物对含氯消毒剂杀菌效果的影响,使用牛血清白蛋白作为有机干扰物,采用悬液定量和载体定量杀菌试验方法进行了实验室观察。结果,用含30 g/L牛血清白蛋白的菌悬液进行试验:有效氯为300 mg/L时可100%杀灭大肠杆菌,需要次氯酸钠溶液作用7.5 m in;三氯异氰尿酸钠片剂和二氯异氰尿酸钠粉剂作用15 m in;以含有效氯2500 mg/L的片剂和粉剂对枯草杆菌黑色变种芽孢作用30 m in,有效氯5000 mg/L次氯酸钠水溶液作用90 m in,杀灭率均达到100%。用含3 g/L牛血清白蛋白的菌悬液进行试验:以含有效氯50 mg/L作用7.5m in,3种剂型含氯消毒剂对大肠杆菌的杀灭率均可达100%。用含有效氯1000 mg/L的片剂和粉剂作用30m in;有效氯2000 mg/L的次氯酸钠水溶液作用60 m in,对枯草杆菌黑色变种芽孢杀灭率均可达100%。用载体法试验:以有效氯300 mg/L次氯酸钠溶液作用7.5 m in,杀灭大肠杆菌100%;以有效氯2000 mg/L次氯酸钠溶液作用60 m in,对枯草杆菌黑色变种芽孢杀灭率100%。结论,在高浓度有机干扰物条件下,含氯消毒剂片剂和粉剂杀灭细菌芽孢剂量明显高于液体制剂;在低浓度有机干扰物条件下,悬液法与载体法对含氯消毒剂杀菌试验结果基本一致。
