Objectives: Evaluation of the effects of withholding plasma during the initial part of the burn shock period (the shock period in the study is estimated as the first 36 hours following the burns) when it will be lost ...Objectives: Evaluation of the effects of withholding plasma during the initial part of the burn shock period (the shock period in the study is estimated as the first 36 hours following the burns) when it will be lost into the interstitial tissues through the permeable capillaries. During that time crystalloids are administered. Another objective is to evaluate the effect of administering normal saline as the crystalloid resuscitation fluid during the initial part of the shock period. Design: A Retrospective 4 years study compares the use of normal saline as the resuscitative intravenous fluid during the first 12 hours post burns followed by intravenous 5% Purified Plasma Protein Fraction (PPPF) during the rest of the shock period i.e. the remaining 24 hours, with the use of the PPPF throughout the burns shock period according to Muir and Barclay formula. Setting: The Plastic Surgery Department and the Department of Laboratory, Directorate General of Khoula Tertiary Hospital, Muscat, Sultanate of Oman. Patients and Methods: The study included 2 groups of patients;Group A: Patients who received 5% Plasma (Human PPPF) throughout the shock period and Group B: Patients who received crystalloids in the form of normal saline during the first 12 hours post burn followed by plasma for the next 24 hours. Monitoring of the patients in both groups was done by using clinical signs of pulse, blood pressure, temperature and urine output and by using laboratory investigations in the form of the haematocrit value, sodium, potassium, chloride, total proteins and albumin levels in the blood at the time of admission and at the end of the shock period. Results: 140 patients were included in the study;64 in Group A and 76 in Group B. There was no mortality and the vital signs were maintained during the shock period in both groups. The mean values of urine output were nearer to the normal level in Group B compared to Group A. The same was observed regarding the Haematocrit value. In both groups the mean values showed no hypoproteinaemia or hypoalbuminaemia at the end of the shock period. There was no hypernatraemia in spite of giving 150 mmol/L of Na during the initial 12 hours post burns in Group B. The mean values of potassium and chloride levels were normal in both groups at the end of the shock period. Conclusion: Giving plasma during the first 12 hours of the burn shock period when the capillary leakage is maximum has no significant benefit. The plasma usage can be reduced by 50% compared to the use of the Muir and Barclay Formula from the beginning of the shock period with reduction of the costs and the possibility of transmission of undetected pathogens by nearly the same value if crystalloids are given during the first 12 hours of burns shock period. The use of isotonic normal saline during the first 12 hours appears more appropriate as it maintains adequate sodium balance to correct the hyponatraemia and at the same time prevents elevation of the serum potassium during the period when potassium is released from the cells. In addition, it does not have a significant reduction on the level of the serum proteins.展开更多
A comparative study is carried out for the nonlinear propagation of ion acoustic shock waves both for the weakly and highly relativistic plasmas consisting of relativistic ions and qdistributed electrons and positions...A comparative study is carried out for the nonlinear propagation of ion acoustic shock waves both for the weakly and highly relativistic plasmas consisting of relativistic ions and qdistributed electrons and positions.The Burgers equation is derived to reveal the physical phenomena using the well known reductive perturbation technique.The integration of the Burgers equation is performed by the（G￠/G）-expansion method.The effects of positron concentration,ion–electron temperature ratio,electron–positron temperature ratio,ion viscosity coefficient,relativistic streaming factor and the strength of the electron and positron nonextensivity on the nonlinear propagation of ion acoustic shock and periodic waves are presented graphically and the relevant physical explanations are provided.展开更多
Current practice uses predictive models to extrapolate long-period response spectra based on far-field recordings in moderate and weak earthquakes. However, the spectra are not long enough and the data are often not r...Current practice uses predictive models to extrapolate long-period response spectra based on far-field recordings in moderate and weak earthquakes. However, the spectra are not long enough and the data are often not reliable, which means that the seismic design code cannot accurately define seismic design requirements for long-period structures. The near-field recordings in the main-shock of the Chi-Chi earthquake have a large signal-to-noise ratio （SNR）, which makes them suitable for studying the long-period acceleration response spectrum up to 20 sec. The acceleration response spectra from 246 stations within 120 km of the causative fault are statistically analyzed in this paper. The influence of distance and site conditions on long-period response spectrum is discussed, and the shapes of the amplification spectra are compared with the standard spectra specified in the seismic design code of China. Finally, suggestions for future revisions to the code are proposed.展开更多
According to the actual working conditions of roller shell in the process ofcontinuous roll casting, the Fourier heat transfer law is used to conduct the simulating analysisfor the temperature distribution of the roll...According to the actual working conditions of roller shell in the process ofcontinuous roll casting, the Fourier heat transfer law is used to conduct the simulating analysisfor the temperature distribution of the roller shell under the condition of periodic thermal shock.The temperature variation law inside the roller shell is studied during the process of continuousroll casting, and the steady temperature distributions of the roller shell at different castingvelocities have been obtained when the thermal contact conductance between the roller shell and thecasting strip is considered.展开更多
针对工业环境中随机冲击干扰下滚动轴承微弱故障特征提取难题,提出一种基于自适应短时维纳滤波(Adaptive Short Time Wiener Filtering,ASTWF)和改进正交匹配追踪(Orthogonal Matching Pursuit,OMP)的滚动轴承故障特征提取方法。该方法...针对工业环境中随机冲击干扰下滚动轴承微弱故障特征提取难题,提出一种基于自适应短时维纳滤波(Adaptive Short Time Wiener Filtering,ASTWF)和改进正交匹配追踪(Orthogonal Matching Pursuit,OMP)的滚动轴承故障特征提取方法。该方法首先采用包络峭度和随余比(Random Shocks and Margin Ratio,RMR)作为联合判据,界定窗长界限并自适应确定STWF最优窗长参数,进而将随机冲击干扰从测试信号中分离出来;然后,利用立方包络自相关谱估计信号中周期频率,构造周期原子库,降低匹配原子冗余度;最后,利用相似性理论优化匹配追踪迭代终止条件,并结合周期原子库,实现弱故障冲击特征快速、准确提取。根据仿真信号和通过变速箱下线检测所得工程数据,可验证所提出方法可有效识别随机冲击干扰下的滚动轴承微弱故障特征。对比最小熵形态反卷积(Minimum Entropy Morphological Deconvolution,MEMD)方法对于随机冲击干扰下滚动轴承微弱故障特征提取效果,发现所提出方法具有更好的故障特征提取能力;与经典OMP方法相比,所提出改进OMP方法信号重构速度提升66%。展开更多
The effect of using camel milk with 2 dates types (Sokary & Al-Khalas), in 3 forms (paste, pieces, and molasses), with 2 different concentrations (5% & 10%) in the manufacturing of ice cream on its viscosity, ...The effect of using camel milk with 2 dates types (Sokary & Al-Khalas), in 3 forms (paste, pieces, and molasses), with 2 different concentrations (5% & 10%) in the manufacturing of ice cream on its viscosity, overrun%, rheological and melting properties during storage period up to 60 days at -18°C was studied. It was noticed that there are higher mean of viscosity values (cp) when using “Al-khalas” dates paste 5% and 10% followed by samples with “sokary” paste then samples with molasses in ice cream samples compared to those with added date’s pieces of either “Sokary” or “Al-khalas”. There are significant differences of overrun values between all treatments and samples with the added date paste of either “sokary” or “Al-khalas” which recorded the lowest values. Increased melting resistance and good qualities as heat shock and melting properties were significantly better for the samples with added dates pieces or paste unlike the molasses. The storage effect is obvious decline, especially when using dates molasses.展开更多
文摘Objectives: Evaluation of the effects of withholding plasma during the initial part of the burn shock period (the shock period in the study is estimated as the first 36 hours following the burns) when it will be lost into the interstitial tissues through the permeable capillaries. During that time crystalloids are administered. Another objective is to evaluate the effect of administering normal saline as the crystalloid resuscitation fluid during the initial part of the shock period. Design: A Retrospective 4 years study compares the use of normal saline as the resuscitative intravenous fluid during the first 12 hours post burns followed by intravenous 5% Purified Plasma Protein Fraction (PPPF) during the rest of the shock period i.e. the remaining 24 hours, with the use of the PPPF throughout the burns shock period according to Muir and Barclay formula. Setting: The Plastic Surgery Department and the Department of Laboratory, Directorate General of Khoula Tertiary Hospital, Muscat, Sultanate of Oman. Patients and Methods: The study included 2 groups of patients;Group A: Patients who received 5% Plasma (Human PPPF) throughout the shock period and Group B: Patients who received crystalloids in the form of normal saline during the first 12 hours post burn followed by plasma for the next 24 hours. Monitoring of the patients in both groups was done by using clinical signs of pulse, blood pressure, temperature and urine output and by using laboratory investigations in the form of the haematocrit value, sodium, potassium, chloride, total proteins and albumin levels in the blood at the time of admission and at the end of the shock period. Results: 140 patients were included in the study;64 in Group A and 76 in Group B. There was no mortality and the vital signs were maintained during the shock period in both groups. The mean values of urine output were nearer to the normal level in Group B compared to Group A. The same was observed regarding the Haematocrit value. In both groups the mean values showed no hypoproteinaemia or hypoalbuminaemia at the end of the shock period. There was no hypernatraemia in spite of giving 150 mmol/L of Na during the initial 12 hours post burns in Group B. The mean values of potassium and chloride levels were normal in both groups at the end of the shock period. Conclusion: Giving plasma during the first 12 hours of the burn shock period when the capillary leakage is maximum has no significant benefit. The plasma usage can be reduced by 50% compared to the use of the Muir and Barclay Formula from the beginning of the shock period with reduction of the costs and the possibility of transmission of undetected pathogens by nearly the same value if crystalloids are given during the first 12 hours of burns shock period. The use of isotonic normal saline during the first 12 hours appears more appropriate as it maintains adequate sodium balance to correct the hyponatraemia and at the same time prevents elevation of the serum potassium during the period when potassium is released from the cells. In addition, it does not have a significant reduction on the level of the serum proteins.
文摘A comparative study is carried out for the nonlinear propagation of ion acoustic shock waves both for the weakly and highly relativistic plasmas consisting of relativistic ions and qdistributed electrons and positions.The Burgers equation is derived to reveal the physical phenomena using the well known reductive perturbation technique.The integration of the Burgers equation is performed by the（G￠/G）-expansion method.The effects of positron concentration,ion–electron temperature ratio,electron–positron temperature ratio,ion viscosity coefficient,relativistic streaming factor and the strength of the electron and positron nonextensivity on the nonlinear propagation of ion acoustic shock and periodic waves are presented graphically and the relevant physical explanations are provided.
基金National Natural Science Foundation of China Under Grant No.40374017
文摘Current practice uses predictive models to extrapolate long-period response spectra based on far-field recordings in moderate and weak earthquakes. However, the spectra are not long enough and the data are often not reliable, which means that the seismic design code cannot accurately define seismic design requirements for long-period structures. The near-field recordings in the main-shock of the Chi-Chi earthquake have a large signal-to-noise ratio （SNR）, which makes them suitable for studying the long-period acceleration response spectrum up to 20 sec. The acceleration response spectra from 246 stations within 120 km of the causative fault are statistically analyzed in this paper. The influence of distance and site conditions on long-period response spectrum is discussed, and the shapes of the amplification spectra are compared with the standard spectra specified in the seismic design code of China. Finally, suggestions for future revisions to the code are proposed.
基金This work was supported by the State Key Project of Fundamental Research(No.199906496).
文摘According to the actual working conditions of roller shell in the process ofcontinuous roll casting, the Fourier heat transfer law is used to conduct the simulating analysisfor the temperature distribution of the roller shell under the condition of periodic thermal shock.The temperature variation law inside the roller shell is studied during the process of continuousroll casting, and the steady temperature distributions of the roller shell at different castingvelocities have been obtained when the thermal contact conductance between the roller shell and thecasting strip is considered.
文摘针对工业环境中随机冲击干扰下滚动轴承微弱故障特征提取难题,提出一种基于自适应短时维纳滤波(Adaptive Short Time Wiener Filtering,ASTWF)和改进正交匹配追踪(Orthogonal Matching Pursuit,OMP)的滚动轴承故障特征提取方法。该方法首先采用包络峭度和随余比(Random Shocks and Margin Ratio,RMR)作为联合判据,界定窗长界限并自适应确定STWF最优窗长参数,进而将随机冲击干扰从测试信号中分离出来;然后,利用立方包络自相关谱估计信号中周期频率,构造周期原子库,降低匹配原子冗余度;最后,利用相似性理论优化匹配追踪迭代终止条件,并结合周期原子库,实现弱故障冲击特征快速、准确提取。根据仿真信号和通过变速箱下线检测所得工程数据,可验证所提出方法可有效识别随机冲击干扰下的滚动轴承微弱故障特征。对比最小熵形态反卷积(Minimum Entropy Morphological Deconvolution,MEMD)方法对于随机冲击干扰下滚动轴承微弱故障特征提取效果,发现所提出方法具有更好的故障特征提取能力;与经典OMP方法相比,所提出改进OMP方法信号重构速度提升66%。
文摘The effect of using camel milk with 2 dates types (Sokary & Al-Khalas), in 3 forms (paste, pieces, and molasses), with 2 different concentrations (5% & 10%) in the manufacturing of ice cream on its viscosity, overrun%, rheological and melting properties during storage period up to 60 days at -18°C was studied. It was noticed that there are higher mean of viscosity values (cp) when using “Al-khalas” dates paste 5% and 10% followed by samples with “sokary” paste then samples with molasses in ice cream samples compared to those with added date’s pieces of either “Sokary” or “Al-khalas”. There are significant differences of overrun values between all treatments and samples with the added date paste of either “sokary” or “Al-khalas” which recorded the lowest values. Increased melting resistance and good qualities as heat shock and melting properties were significantly better for the samples with added dates pieces or paste unlike the molasses. The storage effect is obvious decline, especially when using dates molasses.
