In the introductory part of the thesis, a brief explanation about the dynamic of bubble cavitatio... more In the introductory part of the thesis, a brief explanation about the dynamic of bubble cavitation in homogenous and heterogeneous nucleation, pressure domain bubble growth and collapse. A review of methods used for the calibration of piezoelectric film sensors was elaborated to select the most appropriate method for the cavitation aggressiveness measurement. Regarding the sort pulse duration, the pencil-lead breaking method was selected. The test using the drop ball method was used performed for the comparison. To realize the calibration method an experimental assembly for the pencil-lead breaking method was designed and manufactured. Two kinds of sensors were tested using the pencil lead breaking method and the drop ball method. Pencil-lead breaking calibration two different hardness of 2mm pencil lead with two protruding lengths. The resulting constants are directly applicable to any measurements using tested PVDF films. The applicability of the pencil-lead breaking method was di...
In this paper, results are reported for a series of discrete end hooked and straight fibre pullou... more In this paper, results are reported for a series of discrete end hooked and straight fibre pullout tests subjected to mixed mode action with the results compared to that of discrete fibres pulled out in Mode I (tensile) and Mode II (shear) fracture. As has been previously observed from Modes I and II fracture tests, the snubbing effect dominates the behaviour of fibres at large fibre bending angles. At large fibre bending angles, considerable slip and crack separation occurred prior to the fibres being engaged in taking load and fibres that are inclined close to the cracked surface are ineffective in carrying load. The results of the test were compared with the fibre engagement and bond stress models in the Unified Variable Engagement Model (UVEM). A good correlation is observed for the UVEM model with the test data and provides further confirmation of the validity of the UVEM model to predict the mix mode fracture of steel fibre reinforced concrete.
Background Artemisinin-based combinations are judged the best treatments for multidrug-resistant ... more Background Artemisinin-based combinations are judged the best treatments for multidrug-resistant Plasmodium falciparum malaria. Artesunate-mefl oquine is widely recommended in southeast Asia, but its high cost and tolerability profi le remain obstacles to widespread deployment. To assess whether dihydroartemisinin-piperaquine is a suitable alternative to artesunate-mefl oquine, we compared the safety, tolerability, effi cacy, and eff ectiveness of the two regimens for the treatment of uncomplicated falciparum in western Myanmar (Burma). Methods We did an open randomised comparison of 3-day regimens of artesunate-mefl oquine (12/25 mg/kg) versus dihydroartemisinin-piperaquine (6•3/50 mg/kg) for the treatment of children aged 1 year or older and in adults with uncomplicated falciparum malaria in Rakhine State, western Myanmar. Within each group, patients were randomly assigned supervised or non-supervised treatment. The primary endpoint was the PCR-confi rmed parasitological failure rate by day 42. Failure rates at day 42 were estimated by Kaplan-Meier survival analysis. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN27914471. Findings Of 652 patients enrolled, 327 were assigned dihydroartemisinin-piperaquine (156 supervised and 171 not supervised), and 325 artesunate-mefl oquine (162 and 163, respectively). 16 patients were lost to follow-up, and one patient died 22 days after receiving dihydroartemisinin-piperaquine. Recrudescent parasitaemias were confi rmed in only two patients; the day 42 failure rate was 0•6% (95% CI 0•2-2•5) for dihydroartemisinin-piperaquine and 0 (0-1•2) for artesunate-mefl oquine. Whole-blood piperaquine concentrations at day 7 were similar for patients with observed and non-observed dihydroartemisinin-piperaquine treatment. Gametocytaemia developed more frequently in patients who had received dihydroartemisinin-piperaquine than in those on artesunate-mefl oquine: day 7, 18 (10%) of 188 versus fi ve (2%) of 218; relative risk 4•2 (1•6-11•0) p=0•011. Interpretation Dihydroartemisinin-piperaquine is a highly effi cacious and inexpensive treatment of multidrugresistant falciparum malaria and is well tolerated by all age groups. The eff ectiveness of the unsupervised treatment, as in the usual context of use, equalled its supervised effi cacy, indicating good adherence without supervision. Dihydroartemisinin-piperaquine is a good alternative to artesunate-mefl oquine.
In the introductory part of the thesis, a brief explanation about the dynamic of bubble cavitatio... more In the introductory part of the thesis, a brief explanation about the dynamic of bubble cavitation in homogenous and heterogeneous nucleation, pressure domain bubble growth and collapse. A review of methods used for the calibration of piezoelectric film sensors was elaborated to select the most appropriate method for the cavitation aggressiveness measurement. Regarding the sort pulse duration, the pencil-lead breaking method was selected. The test using the drop ball method was used performed for the comparison. To realize the calibration method an experimental assembly for the pencil-lead breaking method was designed and manufactured. Two kinds of sensors were tested using the pencil lead breaking method and the drop ball method. Pencil-lead breaking calibration two different hardness of 2mm pencil lead with two protruding lengths. The resulting constants are directly applicable to any measurements using tested PVDF films. The applicability of the pencil-lead breaking method was di...
In this paper, results are reported for a series of discrete end hooked and straight fibre pullou... more In this paper, results are reported for a series of discrete end hooked and straight fibre pullout tests subjected to mixed mode action with the results compared to that of discrete fibres pulled out in Mode I (tensile) and Mode II (shear) fracture. As has been previously observed from Modes I and II fracture tests, the snubbing effect dominates the behaviour of fibres at large fibre bending angles. At large fibre bending angles, considerable slip and crack separation occurred prior to the fibres being engaged in taking load and fibres that are inclined close to the cracked surface are ineffective in carrying load. The results of the test were compared with the fibre engagement and bond stress models in the Unified Variable Engagement Model (UVEM). A good correlation is observed for the UVEM model with the test data and provides further confirmation of the validity of the UVEM model to predict the mix mode fracture of steel fibre reinforced concrete.
Background Artemisinin-based combinations are judged the best treatments for multidrug-resistant ... more Background Artemisinin-based combinations are judged the best treatments for multidrug-resistant Plasmodium falciparum malaria. Artesunate-mefl oquine is widely recommended in southeast Asia, but its high cost and tolerability profi le remain obstacles to widespread deployment. To assess whether dihydroartemisinin-piperaquine is a suitable alternative to artesunate-mefl oquine, we compared the safety, tolerability, effi cacy, and eff ectiveness of the two regimens for the treatment of uncomplicated falciparum in western Myanmar (Burma). Methods We did an open randomised comparison of 3-day regimens of artesunate-mefl oquine (12/25 mg/kg) versus dihydroartemisinin-piperaquine (6•3/50 mg/kg) for the treatment of children aged 1 year or older and in adults with uncomplicated falciparum malaria in Rakhine State, western Myanmar. Within each group, patients were randomly assigned supervised or non-supervised treatment. The primary endpoint was the PCR-confi rmed parasitological failure rate by day 42. Failure rates at day 42 were estimated by Kaplan-Meier survival analysis. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN27914471. Findings Of 652 patients enrolled, 327 were assigned dihydroartemisinin-piperaquine (156 supervised and 171 not supervised), and 325 artesunate-mefl oquine (162 and 163, respectively). 16 patients were lost to follow-up, and one patient died 22 days after receiving dihydroartemisinin-piperaquine. Recrudescent parasitaemias were confi rmed in only two patients; the day 42 failure rate was 0•6% (95% CI 0•2-2•5) for dihydroartemisinin-piperaquine and 0 (0-1•2) for artesunate-mefl oquine. Whole-blood piperaquine concentrations at day 7 were similar for patients with observed and non-observed dihydroartemisinin-piperaquine treatment. Gametocytaemia developed more frequently in patients who had received dihydroartemisinin-piperaquine than in those on artesunate-mefl oquine: day 7, 18 (10%) of 188 versus fi ve (2%) of 218; relative risk 4•2 (1•6-11•0) p=0•011. Interpretation Dihydroartemisinin-piperaquine is a highly effi cacious and inexpensive treatment of multidrugresistant falciparum malaria and is well tolerated by all age groups. The eff ectiveness of the unsupervised treatment, as in the usual context of use, equalled its supervised effi cacy, indicating good adherence without supervision. Dihydroartemisinin-piperaquine is a good alternative to artesunate-mefl oquine.
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