An S-N curve fitting approach is proposed based on the weighted least square method, and the weights are inversely proportional to the length of mean confidence intervals of experimental data sets. The assumption coin...An S-N curve fitting approach is proposed based on the weighted least square method, and the weights are inversely proportional to the length of mean confidence intervals of experimental data sets. The assumption coincides with the physical characteristics of the fatigue life scatter. Two examples demonstrate the method. It is shown that the method has better accuracy and reasonableness compared with the usual least square method.展开更多
A noise reduction method for infrared detector output signal is studied during dynamic calibration of thermocou- pie. Firstly, the deficiency of the classical filter method is analyzed and the application of the wavel...A noise reduction method for infrared detector output signal is studied during dynamic calibration of thermocou- pie. Firstly, the deficiency of the classical filter method is analyzed and the application of the wavelet analysis is introduced for signal de-noising during the dynamic testing. Secondly, the theoretical basis of wavelet analysis, the choice of wavelet base and the determination of decomposed series and threshold are analyzed. Finally, the de-noising experiment for infrared detector signal is carried out on the Matlab platform. The results indicate the proposed wavelet de-noising method is effective to remove fixed frequency and high-frequency noise; furthermore, good synchronization is achieved between the de-noised signal and the useful signal components in the original signal, which is of great significance to thermocouple modeling analys- is.展开更多
Sm-doped Fe_(2)O_(3)catalysts,with a homogeneous distribution of Sm in Fe_(2)O_(3)nanoparticles,were synthesized using a citric acid-assisted sol-gel method.Kinetic studies show that the reaction rate for NO_(x)reduct...Sm-doped Fe_(2)O_(3)catalysts,with a homogeneous distribution of Sm in Fe_(2)O_(3)nanoparticles,were synthesized using a citric acid-assisted sol-gel method.Kinetic studies show that the reaction rate for NO_(x)reduction using the optimal catalyst(0.06 mol%doping of Sm in Fe_(2)O_(3))was nearly 11 times higher than that for pure Fe_(2)O_(3),when calculated based on specific surface area.Furthermore,the Fe_(0.94)Sm_(0.06)O_(x)catalyst maintains>83%NO_(x)conversion for 168 h at a high space velocity in the presence of SO_(2)and H_(2)O at 250℃.A substantial amount of surface-adsorbed oxygen was generated on the surface of Fe_(0.94)Sm_(0.06)O_(x),which promoted NO oxidation and the subsequent fast reaction between NO_(x)and NH_(3).The adsorption and activation of NH_(3)was also enhanced by Sm doping.In addition,Sm doping facilitated the decomposition of NH_(4)HSO_(4)on the surface of Fe_(0.94)Sm_(0.06)O_(x),resulting in its high activity and stability in the presence of SO_(2)+H_(2)O.展开更多
AIM： To study a cohort of patients undergoing 48 h Bravo pH testing receiving deep sedation with propofol. METHODS： We retrospectively reviewed the charts of 197 patients （81 male, 116 female） who underwent Bravo ...AIM： To study a cohort of patients undergoing 48 h Bravo pH testing receiving deep sedation with propofol. METHODS： We retrospectively reviewed the charts of 197 patients （81 male, 116 female） who underwent Bravo esophageal pH monitoring from July 2003 to January 2008. All patients underwent Bravo pH probe placement via esophagogastroduodenoscopy （EGD） and received propofol for sedation. Patients on a proton pump inhibitor （89 patients） were excluded. Acid reflux variables measured included the total, upright, and supine fractions of time at pH 〈 4 and DeMeester score, and were compared between day I and day 2. RESULTS： Of the 108 patients that were included in the study, the most common indication for Bravo pH monitoring was heartburn, with chest pain being the second most common. A signed rank test revealed no statistically significant difference between day I and day 2 reflux episodes. CONCLUSION： Patients who received propofol for sedation for EGD with Bravo pH capsule placement did not experience any significant difference in reflux episodes from day 1 to day 2.展开更多
Objective To explore whether the amount of lipocalin-2 in the biofluid could reflect the onset of sepsis-induced acute lung injury(ALI) in mice. Methods Lipopolysaccharide(LPS, 10 mg/kg) injection or cecal ligation an...Objective To explore whether the amount of lipocalin-2 in the biofluid could reflect the onset of sepsis-induced acute lung injury(ALI) in mice. Methods Lipopolysaccharide(LPS, 10 mg/kg) injection or cecal ligation and puncture(CLP) was performed to induce severe sepsis and ALI in C57 BL/6 male mice randomly divided into 5 groups(n=10 in each group): group A(intraperitoneal LPS injection), group B(intravenous LPS injection via tail vein), group C(CLP with 25% of the cecum ligated), group D(CLP with 75% of the cecum ligated), and the control group(6 sham-operation controls plus 4 saline controls). All the mice received volume resuscitation. Measurements of pulmonary morphological and functional alterations were used to identify the presence of experimental ALI. The expressions of lipocalin-2 and interleukin(IL)-6 in serum, bronchoalveolar lavage fluid(BALF), and lung tissue were quantified at both protein and mRNA levels. The overall abilities of lipocalin-2 and IL-6 tests to diagnose sepsis-induced ALI were evaluated by generating receiver operator characteristic curves(ROC) and computing area under curve(AUC). Results In both group B and group D, most of the "main features" of experimental ALI were reproduced in mice, while group A and group C showed septic syndrome without definite evidence for the presence of ALI. Compared with septic mice without ALI(group A+group C), lipocalin-2 protein expression in septic mice with ALI(group B+group D) was significantly up-regulated in BALF(P<0.01) and in serum(P<0.01), and mRNA expression boosted in lung tissues(all P<0.05). Lipocalin-2 tests performed better than IL-6 tests in recognizing sepsis-induced ALI cases, evidenced by the larger AUC of the former(BALF tests, 0.8800 versus 0.6625; serum tests, 0.8500 versus 0.7000). Using a dual cutoff system to diagnose sepsis-induced ALI, BALF lipocalin-2 test exhibited the highest positive likelihood ratio(13.000) and the lowest negative likelihood ratio(0.077) among the tests of lipocalin-2 and IL-6 in blood and BALF. A statistically significant correlation was found between lipocalin-2 concentration in BALF and that in serum(Spearman r=0.8803,P<0.0001). Conclusions Lipocalin-2 expression is significantly up-regulated in septic ALI mice compared with those without ALI. Lipocalin-2 tests with a dual cutoff system could be an effective tool in distinguishing experimental ALI cases.展开更多
＂From Grammar to Critical Woosong University, 2013 Thinking in Seven The purpose of the Steps＂ was presented at the 2013 KOTESOL DCC Symposium, project was to accelerate the learning curve of students with a higher ...＂From Grammar to Critical Woosong University, 2013 Thinking in Seven The purpose of the Steps＂ was presented at the 2013 KOTESOL DCC Symposium, project was to accelerate the learning curve of students with a higher than average IQ （intelligence quotient）, but functionally low in English. The students were required to write an essay, in the last hour of a four hour class. The students were challenged to fix sentences, write the reason they chose, and speak their answer. To determine if this was a one book idea, another test was tried with regular students, using an off the shelf grammar book. Using the same step by step process, the ability of students to make a story from a standard grammar book, was accomplished in a 90-minute class. Students enjoyed the activity and were able to use previously learned ideas in their sequencing and logical choices. This in turn strengthened the writing process, which was the goal. After four sessions, students in the initial trial class achieved better writing and story development skills. The second group did not continue the process due to class and schedule changes. Their understanding of the process was enlarged, but not tested展开更多
Mango fruit （Mangifera indica） is very rich in fibre and vitamin C which are the required nutrients for good health and easy digestion of food in human body system. However, the fruit is highly perishable in its nat...Mango fruit （Mangifera indica） is very rich in fibre and vitamin C which are the required nutrients for good health and easy digestion of food in human body system. However, the fruit is highly perishable in its natural state after harvest due to the chemical deterioration and environmental effects. Due to the perishable nature, abundant wastage during the production season and relative scarcity during the off season were recorded by farmers. Processing the fruit into the form that can easily be stored, preserved, packaged, transported or consumed is crucial to having the product all the year round. Besides, mango juice can be consumed freshly, processed into dry powder, mixed or blended with other juice to make fruit jams, or evaporated to concentrates. These products have a lot of potential in food and beverage industries for export and foreign exchange earnings. Therefore, a small scale machine to process mango fruits to high quality juice is highly essential to reduce the postharvest loss and then add value to the commodity. To achieve this purpose, an abrasion-macerating device （AMD） was designed, fabricated and tested for small scale mango juice extraction. Design considerations focused on the techno-economic status of the micro and small scale fruit juice processors who are the intended users of the machine. The major components of the machine included hopper, perforated drum, screw conveyor, juice outlet, waste outlet, frame, electric motor and motor stand. Other components included screw shaft, the juice collector, top cover and the transmission system. In operation, the screw conveyor conveys and presses the mango fruits against the perforated roughened drum. The abrasion/tearing process of the screw on the flesh of the fruit and further pressing against the drum squeeze enough juice out of the fruit. The juice extracted is drained through the perforated mesh of the juice channel into the juice outlet from where it is collected while the residual waste is collected at the waste outlet. The machine was tested using freshly harvested mango fruits and results obtained showed an average juice yield, extraction efficiency and extraction loss of 34,56%, 55.14% and 10.15%, respectively. These values of juice yield, extraction efficiency and low level of extraction loss indicate satisfactory performance of the machine. Powered by a 2.5 hp single-phase electric motor, the machine has a production cost of USD565 with the construction materials being locally available at affordable costs. A cottage mango juice extraction plant based on this technology can provide employment for at least two persons at the same time providing fresh juice at low costs and residual waste as an ingredient for livestock feed manufacturing.展开更多
Teams developing serious games are often small and face both time and budget constraints. Although its importance is well-established, iterative usability testing is often forgone. Further, serious games present uniqu...Teams developing serious games are often small and face both time and budget constraints. Although its importance is well-established, iterative usability testing is often forgone. Further, serious games present unique challenges that they must be usable, enjoyable, and effective. It is necessary that the game＇s design is evaluated at several stages during development to ensure that all of these objectives are met. A model for incorporating usability testing into development that addresses these three elements is presented, along with guidelines for implementation focused specifically on small serious games development teams. By applying this model to development should ensure that developers are able to efficiently produce more effective serious games.展开更多
文摘An S-N curve fitting approach is proposed based on the weighted least square method, and the weights are inversely proportional to the length of mean confidence intervals of experimental data sets. The assumption coincides with the physical characteristics of the fatigue life scatter. Two examples demonstrate the method. It is shown that the method has better accuracy and reasonableness compared with the usual least square method.
文摘A noise reduction method for infrared detector output signal is studied during dynamic calibration of thermocou- pie. Firstly, the deficiency of the classical filter method is analyzed and the application of the wavelet analysis is introduced for signal de-noising during the dynamic testing. Secondly, the theoretical basis of wavelet analysis, the choice of wavelet base and the determination of decomposed series and threshold are analyzed. Finally, the de-noising experiment for infrared detector signal is carried out on the Matlab platform. The results indicate the proposed wavelet de-noising method is effective to remove fixed frequency and high-frequency noise; furthermore, good synchronization is achieved between the de-noised signal and the useful signal components in the original signal, which is of great significance to thermocouple modeling analys- is.
文摘Sm-doped Fe_(2)O_(3)catalysts,with a homogeneous distribution of Sm in Fe_(2)O_(3)nanoparticles,were synthesized using a citric acid-assisted sol-gel method.Kinetic studies show that the reaction rate for NO_(x)reduction using the optimal catalyst(0.06 mol%doping of Sm in Fe_(2)O_(3))was nearly 11 times higher than that for pure Fe_(2)O_(3),when calculated based on specific surface area.Furthermore,the Fe_(0.94)Sm_(0.06)O_(x)catalyst maintains>83%NO_(x)conversion for 168 h at a high space velocity in the presence of SO_(2)and H_(2)O at 250℃.A substantial amount of surface-adsorbed oxygen was generated on the surface of Fe_(0.94)Sm_(0.06)O_(x),which promoted NO oxidation and the subsequent fast reaction between NO_(x)and NH_(3).The adsorption and activation of NH_(3)was also enhanced by Sm doping.In addition,Sm doping facilitated the decomposition of NH_(4)HSO_(4)on the surface of Fe_(0.94)Sm_(0.06)O_(x),resulting in its high activity and stability in the presence of SO_(2)+H_(2)O.
文摘AIM： To study a cohort of patients undergoing 48 h Bravo pH testing receiving deep sedation with propofol. METHODS： We retrospectively reviewed the charts of 197 patients （81 male, 116 female） who underwent Bravo esophageal pH monitoring from July 2003 to January 2008. All patients underwent Bravo pH probe placement via esophagogastroduodenoscopy （EGD） and received propofol for sedation. Patients on a proton pump inhibitor （89 patients） were excluded. Acid reflux variables measured included the total, upright, and supine fractions of time at pH 〈 4 and DeMeester score, and were compared between day I and day 2. RESULTS： Of the 108 patients that were included in the study, the most common indication for Bravo pH monitoring was heartburn, with chest pain being the second most common. A signed rank test revealed no statistically significant difference between day I and day 2 reflux episodes. CONCLUSION： Patients who received propofol for sedation for EGD with Bravo pH capsule placement did not experience any significant difference in reflux episodes from day 1 to day 2.
基金Supported in part by Jie-shou Li Academician Gut Barrier Research Fund(2012001)
文摘Objective To explore whether the amount of lipocalin-2 in the biofluid could reflect the onset of sepsis-induced acute lung injury(ALI) in mice. Methods Lipopolysaccharide(LPS, 10 mg/kg) injection or cecal ligation and puncture(CLP) was performed to induce severe sepsis and ALI in C57 BL/6 male mice randomly divided into 5 groups(n=10 in each group): group A(intraperitoneal LPS injection), group B(intravenous LPS injection via tail vein), group C(CLP with 25% of the cecum ligated), group D(CLP with 75% of the cecum ligated), and the control group(6 sham-operation controls plus 4 saline controls). All the mice received volume resuscitation. Measurements of pulmonary morphological and functional alterations were used to identify the presence of experimental ALI. The expressions of lipocalin-2 and interleukin(IL)-6 in serum, bronchoalveolar lavage fluid(BALF), and lung tissue were quantified at both protein and mRNA levels. The overall abilities of lipocalin-2 and IL-6 tests to diagnose sepsis-induced ALI were evaluated by generating receiver operator characteristic curves(ROC) and computing area under curve(AUC). Results In both group B and group D, most of the "main features" of experimental ALI were reproduced in mice, while group A and group C showed septic syndrome without definite evidence for the presence of ALI. Compared with septic mice without ALI(group A+group C), lipocalin-2 protein expression in septic mice with ALI(group B+group D) was significantly up-regulated in BALF(P<0.01) and in serum(P<0.01), and mRNA expression boosted in lung tissues(all P<0.05). Lipocalin-2 tests performed better than IL-6 tests in recognizing sepsis-induced ALI cases, evidenced by the larger AUC of the former(BALF tests, 0.8800 versus 0.6625; serum tests, 0.8500 versus 0.7000). Using a dual cutoff system to diagnose sepsis-induced ALI, BALF lipocalin-2 test exhibited the highest positive likelihood ratio(13.000) and the lowest negative likelihood ratio(0.077) among the tests of lipocalin-2 and IL-6 in blood and BALF. A statistically significant correlation was found between lipocalin-2 concentration in BALF and that in serum(Spearman r=0.8803,P<0.0001). Conclusions Lipocalin-2 expression is significantly up-regulated in septic ALI mice compared with those without ALI. Lipocalin-2 tests with a dual cutoff system could be an effective tool in distinguishing experimental ALI cases.
文摘＂From Grammar to Critical Woosong University, 2013 Thinking in Seven The purpose of the Steps＂ was presented at the 2013 KOTESOL DCC Symposium, project was to accelerate the learning curve of students with a higher than average IQ （intelligence quotient）, but functionally low in English. The students were required to write an essay, in the last hour of a four hour class. The students were challenged to fix sentences, write the reason they chose, and speak their answer. To determine if this was a one book idea, another test was tried with regular students, using an off the shelf grammar book. Using the same step by step process, the ability of students to make a story from a standard grammar book, was accomplished in a 90-minute class. Students enjoyed the activity and were able to use previously learned ideas in their sequencing and logical choices. This in turn strengthened the writing process, which was the goal. After four sessions, students in the initial trial class achieved better writing and story development skills. The second group did not continue the process due to class and schedule changes. Their understanding of the process was enlarged, but not tested
文摘Mango fruit （Mangifera indica） is very rich in fibre and vitamin C which are the required nutrients for good health and easy digestion of food in human body system. However, the fruit is highly perishable in its natural state after harvest due to the chemical deterioration and environmental effects. Due to the perishable nature, abundant wastage during the production season and relative scarcity during the off season were recorded by farmers. Processing the fruit into the form that can easily be stored, preserved, packaged, transported or consumed is crucial to having the product all the year round. Besides, mango juice can be consumed freshly, processed into dry powder, mixed or blended with other juice to make fruit jams, or evaporated to concentrates. These products have a lot of potential in food and beverage industries for export and foreign exchange earnings. Therefore, a small scale machine to process mango fruits to high quality juice is highly essential to reduce the postharvest loss and then add value to the commodity. To achieve this purpose, an abrasion-macerating device （AMD） was designed, fabricated and tested for small scale mango juice extraction. Design considerations focused on the techno-economic status of the micro and small scale fruit juice processors who are the intended users of the machine. The major components of the machine included hopper, perforated drum, screw conveyor, juice outlet, waste outlet, frame, electric motor and motor stand. Other components included screw shaft, the juice collector, top cover and the transmission system. In operation, the screw conveyor conveys and presses the mango fruits against the perforated roughened drum. The abrasion/tearing process of the screw on the flesh of the fruit and further pressing against the drum squeeze enough juice out of the fruit. The juice extracted is drained through the perforated mesh of the juice channel into the juice outlet from where it is collected while the residual waste is collected at the waste outlet. The machine was tested using freshly harvested mango fruits and results obtained showed an average juice yield, extraction efficiency and extraction loss of 34,56%, 55.14% and 10.15%, respectively. These values of juice yield, extraction efficiency and low level of extraction loss indicate satisfactory performance of the machine. Powered by a 2.5 hp single-phase electric motor, the machine has a production cost of USD565 with the construction materials being locally available at affordable costs. A cottage mango juice extraction plant based on this technology can provide employment for at least two persons at the same time providing fresh juice at low costs and residual waste as an ingredient for livestock feed manufacturing.
文摘Teams developing serious games are often small and face both time and budget constraints. Although its importance is well-established, iterative usability testing is often forgone. Further, serious games present unique challenges that they must be usable, enjoyable, and effective. It is necessary that the game＇s design is evaluated at several stages during development to ensure that all of these objectives are met. A model for incorporating usability testing into development that addresses these three elements is presented, along with guidelines for implementation focused specifically on small serious games development teams. By applying this model to development should ensure that developers are able to efficiently produce more effective serious games.
