This study examined how social desirability responses confound the relationship between gender and social media addiction.A total of 496 college student social media users(females=310,62.5%,mean age=20.15,SD=1.26)comp...This study examined how social desirability responses confound the relationship between gender and social media addiction.A total of 496 college student social media users(females=310,62.5%,mean age=20.15,SD=1.26)completed an online questionnaire on Social Media Addiction and Social Desirability.Mediation analysis revealed that females were at higher risk for social media addiction.On the other hand,the indirect effect of gender on social media addiction via social desirability is associated with lower social media addiction,which suggests that social desirability had a suppression effect on social media addiction associated with gender.ANOVA results showed that females reported higher social media addiction scores than males in the low social desirability group;in the high group,gender differences were insignificant.This study’s unique contribution is to suggest that females are at higher risk than males for developing addictive social media behaviors.Based on this finding,student social media safety interventions should be gender sensitive to the social desirability effect on females who may hide their true addiction as a result.展开更多
In situ recycling is one of the most effective methods to dispose of earth pressure balance(EPB)shield waste muck with residual foaming agents with high moisture content.In this context,response surface methodology(RS...In situ recycling is one of the most effective methods to dispose of earth pressure balance(EPB)shield waste muck with residual foaming agents with high moisture content.In this context,response surface methodology(RSM)was employed to quantify the effects of independent variables,including flocculant dosage,defoamer dosage,and muck drying mass(MDM)and their interactions on defoaming-flocculation-dewatering indices.The polymeric aluminum chloride(PACL)and hydroxy silicone oil-glycerol polypropylene ether(H-G)were selected as the flocculant and defoamer.The contents of surfactants and foam stabilizers in residual foaming agents were determined using the proposed empirical equation.The defoaming ratio,antifoaming ratio,turbidity,moisture content,filtration loss ratio,and fall cone penetration depth were considered as dependent variables.The accuracy of developed RSM models was verified by the analysis results of variance,residuals,and paired t-test.Combined with the desirability approach,an optimal mixing ratio of 0.078 wt%PACL,0.016 wt%H-G,and 27.882 wt%MDM was recommended,leading to a defoaming ratio of 98.34 vol%for residual foams and a moisture content of 56.72 wt%for pressure-filtration cakes.Our findings were demonstrated to be able to provide useful guidance for prediction and optimization of the in situ recycling indicators of EPB shield waste muck in metro tunnel construction sites.展开更多
In this study,2~5 （five factors at two-level factorial design） design of experiment was applied to investigate a set of optimal machining parameters to achieve a minimum surface roughness value for Abies nordmannian...In this study,2~5 （five factors at two-level factorial design） design of experiment was applied to investigate a set of optimal machining parameters to achieve a minimum surface roughness value for Abies nordmanniana.Wood specimens were prepared using different values of spindle speed,feed rate,depth of cut,tool radius,and cutting directions.Average surface roughness （R_z） values were applied using a stylus.The objectives were to：（1）obtain the effective variables of wood surface roughness;（2） analyze which of these factors had an impact on variability in the CNC machining process;（3） evaluate the optimal cutting values within the range of different cutting levels of machining parameters.The results indicate that the design of experiment（DOE） based on the desirability function approach determined the optimal machining parameters successfully,leading to minimum R_a compared to the observed value.Minimum surface roughness values of tangential and radial cutting directions were 3.58 and 3.21 μm,respectively.展开更多
To reduce the fuel consumption and emissions and also enhance the molten aluminum quality, a mathematical model with user-developed melting model and burning capacity model, were established according to the features ...To reduce the fuel consumption and emissions and also enhance the molten aluminum quality, a mathematical model with user-developed melting model and burning capacity model, were established according to the features of melting process of regenerative aluminum melting furnaces. Based on validating results by heat balance test for an aluminum melting furnace, CFD （computational fluid dynamics） technique, in association with statistical experimental design were used to optimize the melting process of the aluminum melting furnace. Four important factors influencing the melting time, such as horizontal angle between burners, height-to-radius ratio, natural gas mass flow and air preheated temperature, were identified by PLACKETT-BURMAN design. A steepest descent method was undertaken to determine the optimal regions of these factors. Response surface methodology with BOX-BEHNKEN design was adopted to further investigate the mutual interactions between these variables on RSD （relative standard deviation） of aluminum temperature, RSD of furnace temperature and melting time. Multiple-response optimization by desirability function approach was used to determine the optimum melting process parameters. The results indicate that the interaction between the height-to-radius ratio and horizontal angle between burners affects the response variables significantly. The predicted results show that the minimum RSD of aluminum temperature （12.13%）, RSD of furnace temperature （18.50%） and melting time （3.9 h） could be obtained under the optimum conditions of horizontal angle between burners as 64°, height-to-radius ratio as 0.3, natural gas mass flow as 599 m3/h, and air preheated temperature as 639 ℃. These predicted values were further verified by validation experiments. The excellent correlation between the predicted and experimental values confirms the validity and practicability of this statistical optimum strategy.展开更多
Lipopeptides are currently re-emerging as an interesting subgroup in the peptide research field, having historical applications as antibacterial and antifungal agents and new potential applications as antiviral, antit...Lipopeptides are currently re-emerging as an interesting subgroup in the peptide research field, having historical applications as antibacterial and antifungal agents and new potential applications as antiviral, antitumor, immune-modulating and cell-penetrating compounds. However, due to their specific structure, chromatographic analysis often requires special buffer systems or the use of trifluoroacetic acid, limiting mass spectrometry detection. Therefore, we used a traditional aqueous/acetonitrile based gradient system, containing 0.1% （m/v） formic acid, to separate four pharmaceutically relevant lipopeptides （polymyxin B1, caspofungin, daptomycin and gramicidin A1）, which were selected based upon hierarchical cluster analysis （HCA） and principal component analysis （PCA）.In total, the performance of four different C18 columns, including one UPLC column, were evaluated using two parallel approaches. First, a Derringer desirability function was used, whereby six single and multiple chromatographic response values were rescaled into one overall D-value per column. Using this approach, the YMC Pack Pro C18 column was ranked as the best column for general MS-compatible lipopeptide separation. Secondly, the kinetic plot approach was used to compare the different columns at different flow rate ranges. As the optimal kinetic column performance is obtained at its maximal pressure, the length elongation factor λ（Pmax/Pexp） was used to transform the obtained experimental data （retention times and peak capacities） and construct kinetic performance limit （KPL） curves, allowing a direct visual and unbiased comparison of the selected columns, whereby the YMC Triart C18 UPLC and ACE C18 columns performed as best. Finally, differences in column performance and the （dis）advantages of both approaches are discussed.展开更多
In this study, the desirability function approach was used to simultaneously optimize multiple factors. The variables evaluated were combinations of growth regulators, media and organs in affecting the organogenesis o...In this study, the desirability function approach was used to simultaneously optimize multiple factors. The variables evaluated were combinations of growth regulators, media and organs in affecting the organogenesis of Alhagi. In the first step of this study, various experiments were carried out in order to optimize the callus induction and its growth. The highest rate of callus induction was achieved from the leaf segment on MS medium supplemented with 3 mg·l-1 BAP + 6 mg·l-1 NAA. Moreover, the highest rate of regeneration was recorded on MS medium supplemented with those 4 mg·l-1 BAP using for leaf segments. The optimized condition of roots induction per shoot was observed in the 1/4 MS medium without activated charcoal and supplemented with 0.25 mg·l-1 IAA. The well rooted plantlets were acclimatized and successfully established into soil where 70% plantlets were survived. The data indicate that media, BAP, and NAA levels may be manipulated to increase or decrease quality factors chosen.展开更多
COVID-19 has highlighted the underlying global burden from non-communicable diseases (NCDs) and the lack of resiliency in health systems to tackle highly preventable risk factors, which have left populations vulnerabl...COVID-19 has highlighted the underlying global burden from non-communicable diseases (NCDs) and the lack of resiliency in health systems to tackle highly preventable risk factors, which have left populations vulnerable to acute health crises. The persistent issue of unhealthy behaviors, particularly those related to a high-sodium diet, suggests inadequate policy attention and insufficient funding for public health and behavioral research. This year, Japan will host the Tokyo Nutrition for Growth (N4G) Summit 2021. The summit is being held in the era of COVID-19, offering a historic opportunity to make a difference on the global health agenda for food and nutrition and to reaffirm the global commitment to prevent future health crises by addressing the growing burden of NCDs and building better prepared and more resilient health systems. This perspective article suggests that we, global health researchers and decision-makers, should rethink the value of using “Umami” substances as candidates for a practical salt-reducing alternative that originated in Japan (while maintaining the affordability, accessibility, availability, and desirability of healthy food). Reduced salt intake will help address the global syndemic of COVID-19 pandemic and high rates of hypertension, heart diseases, diabetes, and other NCDs. By addressing these issues, it will make countries more resilient to future pandemic threats.展开更多
The purpose of this study was to detect social desirable response bias on Chinese nurses’ attitudes and beliefs toward sexuality care of cancer patients. A cross-sectional self-reported questionnaire based survey was...The purpose of this study was to detect social desirable response bias on Chinese nurses’ attitudes and beliefs toward sexuality care of cancer patients. A cross-sectional self-reported questionnaire based survey was used. Measures included a 12-item Inventory of Sexuality Attitude and Belief Survey (SABS) and a 10-item Marlowe-Crowne Social Desirability Scale. Total social desirability scores were significantly correlated with four individual items of the SABS, and significantly predicted the total SABS scores (β=﹣0.155, p= 0.028). Before controlling social desirability variable, nurses’ age, marital status, years of working experience, and working units were significantly correlated with total SABS scores. After controlling social desirability variable, only nurses’ age and working units were statistically significant predictors of SABS. Social desirable response bias had impacts on Chinese nurses’ attitudes and beliefs toward sexuality care of cancer patients. Study findings demonstrated that social desirable response bias would potentially jeopardize human sexuality assessment and counseling in nursing practice. Controlling social desirable response should consider using a social desirability scale to detect and control potential social desirability bias during data analysis.展开更多
Objective: It is in order to examine associations between social desirability (SD) and self-reports of abstinence among youths in rural Ethiopia. Methods: Youths of ages 15-24 (114 participants) were administered ques...Objective: It is in order to examine associations between social desirability (SD) and self-reports of abstinence among youths in rural Ethiopia. Methods: Youths of ages 15-24 (114 participants) were administered questionnaire to assess HIV knowledge and primary abstinence and a modified Marlowe-Crowne Social Desirability Scale to assess SD bias. The relationships between SD groups (dichotomized into high and low) and abstinence by various characteristics were assessed by using Fisher’s exact p-values. Results: The odds of individuals reporting abstinence were 13.2 times greater in the high SD group compared to the low SD group (p-value 0.002) when adjusted for education, gender, age group, and HIV knowledge. The differences in abstinence between the high and low SD score groups were also examined for selected variables. Conclusions: Individuals who exhibited more SD bias were more likely to report primary abstinence. SD bias should be considered when conducting self-reported surveys to measure the effectiveness of HIV prevention programs.展开更多
KM （knowledge management） has in the recent past been promoted as a means of harnessing and utilising intellectual resources and to improve innovation, business performance and client satisfaction within the constru...KM （knowledge management） has in the recent past been promoted as a means of harnessing and utilising intellectual resources and to improve innovation, business performance and client satisfaction within the construction industry. However, there has been no attempt to ascertain the required level of KM within any given firm. The study reported in this paper aimed at establishing a general equation for assessing a firm’s required level of KM. Through literature review and a questionnaire survey, a total of 22 key indicators of KM were established. The interaction and effects of the key indicators against turnover and employee base were established, yielding an elliptic paraboloid fitted graph over which desirability could be calculated. It was observed that there is a continuous relationship among the firm’s turnover, employee base and the identified key indicators. In practice, firms have different combinations of the employee base and turnover. The derived equation fits well with the different combinations. Firms can, through the use of such equations, determine the level of effort and investment required to implement KM.展开更多
Response surface methodology (RSM) based on desirability function approach (DFA) is applied to obtain an optimal design of the impeller geometry for an automotive torque converter. <span style="font-family:Ver...Response surface methodology (RSM) based on desirability function approach (DFA) is applied to obtain an optimal design of the impeller geometry for an automotive torque converter. <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The relative importance of six design parameters including impeller blade number, blade thickness, bias angle, scroll angle, inlet angle and exit angle is investigated using orthogonal design approach. </span></span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">The impeller inlet angle, exit angle and bias angle </span><span style="font-family:Verdana;">are found to exert the greatest influence on the overall performance of a torque converter, with two flow area factors being considered, namely 17% and 20%. Then, RSM together with central composite design (CCD) method is used to in-depth evaluate the interaction effect of the three key parameters on converter performance. The results demonstrate that </span><span style="font-family:Verdana;">impeller exit angle has the strongest impact on peak efficiency</span><span style="font-family:Verdana;">, with larger angles yielding the most favorable results. The stall torque ratio maximization is attainable with the increase of impeller bias angle and inlet angle together with smaller exit angle. In the end, </span><span style="font-family:Verdana;">an optimized design for the impeller geometry is obtained with stall torque ratio and peak efficiency increased by 1.62% and 1.1%, respectively.</span><span style="font-family:Verdana;"> The new optimization method can be used as a reference for performance enhancement in the design process of impeller geometry for an automotive torque converter.</span></span></span></span>展开更多
The MBTI(Myers-Briggs Type Indicator)remains widely used in many counseling applications despite extensive criticism of its basic nature and psychometric properties.The present study was designed to examine specifical...The MBTI(Myers-Briggs Type Indicator)remains widely used in many counseling applications despite extensive criticism of its basic nature and psychometric properties.The present study was designed to examine specifically the accuracy of the claimed minimal influence of social desirability on Form G of the MBTI.Undergraduate students(n=26)judged the desirability of each item option of Form G,which was compared across the 60 item pairs in which both options were scored.The rated values were approximately equal for two domains,while J and E item options were judged to be more desirable than their P and I paired response options.A second study(n=52)evaluated the social desirability of the 16 MBTI type descriptors,finding most descriptions to be above the neutral range in desirability.These results suggest that stylistic responding contaminates MBTI profiles and interpretative material.Consequently,users should consider alternative measures and at the very least,take great care in interpreting the MBTI because of its flawed structure.展开更多
Cashew processing in Côte d’Ivoire focuses only on the cashew nut, to the detriment of the apple. Only a very small proportion of the apple is processed into juice. The aim of this work is to enhance the value o...Cashew processing in Côte d’Ivoire focuses only on the cashew nut, to the detriment of the apple. Only a very small proportion of the apple is processed into juice. The aim of this work is to enhance the value of cashew apples by transforming them into jam. Specifically, the aim was first to characterize the sensory properties of cashew apple jam formulations using baobab powder as a source of pectin and then to optimise the formulations. A Box-Behken design with pH, Sugar, and Baobab as factors was used to model and characterize the jam sensory descriptors, and a multivariate analysis with SensomineR was used to characterize the jam formulations. The desirability function was used to optimise the formulations. The results show globally significant regressions at the 0.05 threshold for the sensory descriptors Gelling, Brilliance, Smell, Sweetness, and (-)Astringency, with the exception of (-)Salinity. The R2 coefficients are greater than 80%. The factors studied could have effects on the sensory descriptors of cashew jam formulations. The Baobab had the main effect on the gelling, smell, and astringency of the jams. Brilliance depended on the added sugar. A product effect (p < 0.001) was observed for the descriptors Smell, Gelling, Brilliance, and Sweetness, as these allowed the panelists to find differences between the formulations. Optimum jam formulation can be achieved with 51.56% sugar and 2.12% Baobab at a pH of 3.15. Cashew apple jam using Baobab offers opportunities to add value to apples that have long been abandoned in the field. It would be important to find conditions for prolonged storage of this jam.展开更多
The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increas...The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increases with cement sand ratio(CSR),slurry concentration(SC),and curing age(CA),while flow resistance(FR)increases with SC and backfill flow rate(BFR),and decreases with CSR.Then the regression models of UCS and FR as response values were established through RSM.Multi-factor interaction found that CSR-CA impacted UCS most,while SC-BFR impacted FR most.By introducing the desirability function,the optimal backfill parameters were obtained based on RSM-DF(CSR is 1:6.25,SC is 69%,CA is 11.5 d,and BFR is 90 m^(3)/h),showing close results of Design Expert and high reliability for optimization.For a copper mine in China,RSM-DF optimization will reduce cement consumption by 4758 t per year,increase tailings consumption by about 6700 t,and reduce CO_(2)emission by about 4758 t.Thus,RSM-DF provides a new approach for backfill parameters optimization,which has important theoretical and practical values.展开更多
From international student to professor,Tripathi Mani shares his thoughts on Chinese and Indian cultures and the beneficial exchanges between them.TRIPATHI Vivek Mani first learned about China from bedtime stories tol...From international student to professor,Tripathi Mani shares his thoughts on Chinese and Indian cultures and the beneficial exchanges between them.TRIPATHI Vivek Mani first learned about China from bedtime stories told by his father,a Sanskrit teacher in rural Bihar,a state in east India.Many of the stories were about the Chinese monk Xuanzang’s adventures during his long journey to India to find Buddhist scriptures.They kindled the young boy’s interest in China and the desire to visit it one day.展开更多
Suppressing the coffee ring effect(CRE)of an aqueous suspension through manipulation without affecting the remaining deposit is highly desirable for practical applications;however,this is extremely challenging.Here,we...Suppressing the coffee ring effect(CRE)of an aqueous suspension through manipulation without affecting the remaining deposit is highly desirable for practical applications;however,this is extremely challenging.Here,we demonstrate CRE suppression with undetectable disturbance of the deposit on carbon-based surfaces.This was achieved by adding ammonium bicarbonate(NH4HCO_(3)),which benefits from the dissociation of NH_(4)HCO_(3) to produce NH_(4)^(+),as well as its decomposition into NH_(3) and CO_(2) molecules.Surprisingly,NH_(4)^(+) can also function as Na^(+)/K^(+)to suppress the CRE through cation interactions,although its hydrate state is only partially positively charged.Moreover,we successfully applied this approach to enhance the morphology,resistance,and color uniformity of deposits of graphene oxide quantum dots,conductive inks,and organic dyes,respectively.This study provides a practical strategy for improving the performance of fabricated devices and paves the way for the development of high-accuracy manufacturing techniques in diverse industries.展开更多
This paper addresses the time-varying formation-containment(FC) problem for nonholonomic multi-agent systems with a desired trajectory constraint, where only the leaders can acquire information about the desired traje...This paper addresses the time-varying formation-containment(FC) problem for nonholonomic multi-agent systems with a desired trajectory constraint, where only the leaders can acquire information about the desired trajectory. Input the fixed time-varying formation template to the leader and start executing, this process also needs to track the desired trajectory, and the follower needs to converge to the convex hull that the leader crosses. Firstly, the dynamic models of nonholonomic systems are linearized to second-order dynamics. Then, based on the desired trajectory and formation template, the FC control protocols are proposed. Sufficient conditions to achieve FC are introduced and an algorithm is proposed to resolve the control parameters by solving an algebraic Riccati equation. The system is demonstrated to achieve FC, with the average position and velocity of the leaders converging asymptotically to the desired trajectory. Finally, the theoretical achievements are verified in simulations by a multi-agent system composed of virtual human individuals.展开更多
Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to...Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to study their physical,chemical,and mechanical properties.In this context,the present study relates to the extraction,characterization,and optimization of Typha angustata L.stem fibers.For this purpose,desirability functions and response surface methodology were applied to simultaneously optimize the diameter(D),linear density(LD);yield(Y),lignin fraction(L),and tenacity(T)of Typha stem fibers.Typha stems have been subjected to both alkali(NaOH)and enzymatic(pectinex ultra-SPL)treatments.Three levels of process variables including enzyme concentration(10,15,and 20 ml/L)and treatment duration(10,15,and 20 days)were used to design the experiments according to the factorial design.Experimental results were examined by analysis of variance and fitted to second order polynomial model using multiple regression analysis.The Derringer’s desirability function released that the values of process variables generating optimized diameter,linear density,yield,lignin ratio and tenacity are 20 ml/L and 20 days for concentration of pectinex ultra-SPL enzyme and treatment duration,respectively.Confirmation was performed and high degree of correlation was found between the experimental and statistical values.Moreover,the morphological structure has been investigated by the scanning electron microscope,showing a crenelated structure of ultimate fiber bundles of cellulose composing the Typha fiber.Compared to Typha stem non-treated fibers(TSNTF),Typha stem combined treated fibers(TSCTF),brings to improve mechanical properties.This change in mechanical properties is affected by modifying the fiber structure showing alpha cellulose of(66.86%)and lignin ratio of(10.83%)with a crystallinity index of(58.47%).展开更多
The carbon dioxide(CO_(2))reduction process involves complex protonation,making the resulting product often unpredictable.To achieve the desired product,it is crucial to manipulate the reaction steps.Herein,we build t...The carbon dioxide(CO_(2))reduction process involves complex protonation,making the resulting product often unpredictable.To achieve the desired product,it is crucial to manipulate the reaction steps.Herein,we build the metal atom pair sites for selective CO_(2)photoreduction into methane.As a prototype,Ni atom pair sites loaded on the Mo S_(2)nanosheets were synthesized and verified by highresolution transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS)and X-rayabsorption near edge structure spectra(XANES).In-situ Fourier transform infrared spectroscopy(FTIR)monitors the*CHO group,a crucial intermediate in CH_(4)production,during CO_(2)photoreduction on the Ni-Mo S_(2)nanosheets,whereas this monitoring is not observed for the Mo S_(2)nanosheets.Also,theoretical calculations disclose that over the Ni-Mo S_(2)nanosheet slab,the formation energy of*CHO intermediates is determined to be lower(0.585 e V)than the desorption energy of*CO intermediates for CO production(0.64 e V),implying the higher selectivity of CH_(4)production.展开更多
基金supported by the Guangdong Education Science Planning Project(2024GXJK612).
文摘This study examined how social desirability responses confound the relationship between gender and social media addiction.A total of 496 college student social media users(females=310,62.5%,mean age=20.15,SD=1.26)completed an online questionnaire on Social Media Addiction and Social Desirability.Mediation analysis revealed that females were at higher risk for social media addiction.On the other hand,the indirect effect of gender on social media addiction via social desirability is associated with lower social media addiction,which suggests that social desirability had a suppression effect on social media addiction associated with gender.ANOVA results showed that females reported higher social media addiction scores than males in the low social desirability group;in the high group,gender differences were insignificant.This study’s unique contribution is to suggest that females are at higher risk than males for developing addictive social media behaviors.Based on this finding,student social media safety interventions should be gender sensitive to the social desirability effect on females who may hide their true addiction as a result.
基金supported by the National Youth Top-notch Talent Support Program of China(Grant No.00389335)the National Natural Science Foundation of China(Grant No.52378392)the“Foal Eagle Program”Youth Top-notch Talent Project of Fujian Province(Grant No.00387088).
文摘In situ recycling is one of the most effective methods to dispose of earth pressure balance(EPB)shield waste muck with residual foaming agents with high moisture content.In this context,response surface methodology(RSM)was employed to quantify the effects of independent variables,including flocculant dosage,defoamer dosage,and muck drying mass(MDM)and their interactions on defoaming-flocculation-dewatering indices.The polymeric aluminum chloride(PACL)and hydroxy silicone oil-glycerol polypropylene ether(H-G)were selected as the flocculant and defoamer.The contents of surfactants and foam stabilizers in residual foaming agents were determined using the proposed empirical equation.The defoaming ratio,antifoaming ratio,turbidity,moisture content,filtration loss ratio,and fall cone penetration depth were considered as dependent variables.The accuracy of developed RSM models was verified by the analysis results of variance,residuals,and paired t-test.Combined with the desirability approach,an optimal mixing ratio of 0.078 wt%PACL,0.016 wt%H-G,and 27.882 wt%MDM was recommended,leading to a defoaming ratio of 98.34 vol%for residual foams and a moisture content of 56.72 wt%for pressure-filtration cakes.Our findings were demonstrated to be able to provide useful guidance for prediction and optimization of the in situ recycling indicators of EPB shield waste muck in metro tunnel construction sites.
基金performed in the laboratuary of Istanbul University,Faculty of Forestry where the authors are employed at present
文摘In this study,2~5 （five factors at two-level factorial design） design of experiment was applied to investigate a set of optimal machining parameters to achieve a minimum surface roughness value for Abies nordmanniana.Wood specimens were prepared using different values of spindle speed,feed rate,depth of cut,tool radius,and cutting directions.Average surface roughness （R_z） values were applied using a stylus.The objectives were to：（1）obtain the effective variables of wood surface roughness;（2） analyze which of these factors had an impact on variability in the CNC machining process;（3） evaluate the optimal cutting values within the range of different cutting levels of machining parameters.The results indicate that the design of experiment（DOE） based on the desirability function approach determined the optimal machining parameters successfully,leading to minimum R_a compared to the observed value.Minimum surface roughness values of tangential and radial cutting directions were 3.58 and 3.21 μm,respectively.
基金Project(2009BSXT022) supported by the Dissertation Innovation Foundation of Central South University, ChinaProject(07JJ4016) supported by Natural Science Foundation of Hunan Province, ChinaProject(U0937604) supported by National Natural Science Foundation of China
文摘To reduce the fuel consumption and emissions and also enhance the molten aluminum quality, a mathematical model with user-developed melting model and burning capacity model, were established according to the features of melting process of regenerative aluminum melting furnaces. Based on validating results by heat balance test for an aluminum melting furnace, CFD （computational fluid dynamics） technique, in association with statistical experimental design were used to optimize the melting process of the aluminum melting furnace. Four important factors influencing the melting time, such as horizontal angle between burners, height-to-radius ratio, natural gas mass flow and air preheated temperature, were identified by PLACKETT-BURMAN design. A steepest descent method was undertaken to determine the optimal regions of these factors. Response surface methodology with BOX-BEHNKEN design was adopted to further investigate the mutual interactions between these variables on RSD （relative standard deviation） of aluminum temperature, RSD of furnace temperature and melting time. Multiple-response optimization by desirability function approach was used to determine the optimum melting process parameters. The results indicate that the interaction between the height-to-radius ratio and horizontal angle between burners affects the response variables significantly. The predicted results show that the minimum RSD of aluminum temperature （12.13%）, RSD of furnace temperature （18.50%） and melting time （3.9 h） could be obtained under the optimum conditions of horizontal angle between burners as 64°, height-to-radius ratio as 0.3, natural gas mass flow as 599 m3/h, and air preheated temperature as 639 ℃. These predicted values were further verified by validation experiments. The excellent correlation between the predicted and experimental values confirms the validity and practicability of this statistical optimum strategy.
基金funded by PhD grants of ‘Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen)’ (Nos. 101529 (MD) and 121512 (BG))The Special Research Fund (BOF) of Ghent University (01J22510 (EW) and 01D38811 (SS))
文摘Lipopeptides are currently re-emerging as an interesting subgroup in the peptide research field, having historical applications as antibacterial and antifungal agents and new potential applications as antiviral, antitumor, immune-modulating and cell-penetrating compounds. However, due to their specific structure, chromatographic analysis often requires special buffer systems or the use of trifluoroacetic acid, limiting mass spectrometry detection. Therefore, we used a traditional aqueous/acetonitrile based gradient system, containing 0.1% （m/v） formic acid, to separate four pharmaceutically relevant lipopeptides （polymyxin B1, caspofungin, daptomycin and gramicidin A1）, which were selected based upon hierarchical cluster analysis （HCA） and principal component analysis （PCA）.In total, the performance of four different C18 columns, including one UPLC column, were evaluated using two parallel approaches. First, a Derringer desirability function was used, whereby six single and multiple chromatographic response values were rescaled into one overall D-value per column. Using this approach, the YMC Pack Pro C18 column was ranked as the best column for general MS-compatible lipopeptide separation. Secondly, the kinetic plot approach was used to compare the different columns at different flow rate ranges. As the optimal kinetic column performance is obtained at its maximal pressure, the length elongation factor λ（Pmax/Pexp） was used to transform the obtained experimental data （retention times and peak capacities） and construct kinetic performance limit （KPL） curves, allowing a direct visual and unbiased comparison of the selected columns, whereby the YMC Triart C18 UPLC and ACE C18 columns performed as best. Finally, differences in column performance and the （dis）advantages of both approaches are discussed.
文摘In this study, the desirability function approach was used to simultaneously optimize multiple factors. The variables evaluated were combinations of growth regulators, media and organs in affecting the organogenesis of Alhagi. In the first step of this study, various experiments were carried out in order to optimize the callus induction and its growth. The highest rate of callus induction was achieved from the leaf segment on MS medium supplemented with 3 mg·l-1 BAP + 6 mg·l-1 NAA. Moreover, the highest rate of regeneration was recorded on MS medium supplemented with those 4 mg·l-1 BAP using for leaf segments. The optimized condition of roots induction per shoot was observed in the 1/4 MS medium without activated charcoal and supplemented with 0.25 mg·l-1 IAA. The well rooted plantlets were acclimatized and successfully established into soil where 70% plantlets were survived. The data indicate that media, BAP, and NAA levels may be manipulated to increase or decrease quality factors chosen.
文摘COVID-19 has highlighted the underlying global burden from non-communicable diseases (NCDs) and the lack of resiliency in health systems to tackle highly preventable risk factors, which have left populations vulnerable to acute health crises. The persistent issue of unhealthy behaviors, particularly those related to a high-sodium diet, suggests inadequate policy attention and insufficient funding for public health and behavioral research. This year, Japan will host the Tokyo Nutrition for Growth (N4G) Summit 2021. The summit is being held in the era of COVID-19, offering a historic opportunity to make a difference on the global health agenda for food and nutrition and to reaffirm the global commitment to prevent future health crises by addressing the growing burden of NCDs and building better prepared and more resilient health systems. This perspective article suggests that we, global health researchers and decision-makers, should rethink the value of using “Umami” substances as candidates for a practical salt-reducing alternative that originated in Japan (while maintaining the affordability, accessibility, availability, and desirability of healthy food). Reduced salt intake will help address the global syndemic of COVID-19 pandemic and high rates of hypertension, heart diseases, diabetes, and other NCDs. By addressing these issues, it will make countries more resilient to future pandemic threats.
文摘The purpose of this study was to detect social desirable response bias on Chinese nurses’ attitudes and beliefs toward sexuality care of cancer patients. A cross-sectional self-reported questionnaire based survey was used. Measures included a 12-item Inventory of Sexuality Attitude and Belief Survey (SABS) and a 10-item Marlowe-Crowne Social Desirability Scale. Total social desirability scores were significantly correlated with four individual items of the SABS, and significantly predicted the total SABS scores (β=﹣0.155, p= 0.028). Before controlling social desirability variable, nurses’ age, marital status, years of working experience, and working units were significantly correlated with total SABS scores. After controlling social desirability variable, only nurses’ age and working units were statistically significant predictors of SABS. Social desirable response bias had impacts on Chinese nurses’ attitudes and beliefs toward sexuality care of cancer patients. Study findings demonstrated that social desirable response bias would potentially jeopardize human sexuality assessment and counseling in nursing practice. Controlling social desirable response should consider using a social desirability scale to detect and control potential social desirability bias during data analysis.
文摘Objective: It is in order to examine associations between social desirability (SD) and self-reports of abstinence among youths in rural Ethiopia. Methods: Youths of ages 15-24 (114 participants) were administered questionnaire to assess HIV knowledge and primary abstinence and a modified Marlowe-Crowne Social Desirability Scale to assess SD bias. The relationships between SD groups (dichotomized into high and low) and abstinence by various characteristics were assessed by using Fisher’s exact p-values. Results: The odds of individuals reporting abstinence were 13.2 times greater in the high SD group compared to the low SD group (p-value 0.002) when adjusted for education, gender, age group, and HIV knowledge. The differences in abstinence between the high and low SD score groups were also examined for selected variables. Conclusions: Individuals who exhibited more SD bias were more likely to report primary abstinence. SD bias should be considered when conducting self-reported surveys to measure the effectiveness of HIV prevention programs.
文摘KM （knowledge management） has in the recent past been promoted as a means of harnessing and utilising intellectual resources and to improve innovation, business performance and client satisfaction within the construction industry. However, there has been no attempt to ascertain the required level of KM within any given firm. The study reported in this paper aimed at establishing a general equation for assessing a firm’s required level of KM. Through literature review and a questionnaire survey, a total of 22 key indicators of KM were established. The interaction and effects of the key indicators against turnover and employee base were established, yielding an elliptic paraboloid fitted graph over which desirability could be calculated. It was observed that there is a continuous relationship among the firm’s turnover, employee base and the identified key indicators. In practice, firms have different combinations of the employee base and turnover. The derived equation fits well with the different combinations. Firms can, through the use of such equations, determine the level of effort and investment required to implement KM.
文摘Response surface methodology (RSM) based on desirability function approach (DFA) is applied to obtain an optimal design of the impeller geometry for an automotive torque converter. <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The relative importance of six design parameters including impeller blade number, blade thickness, bias angle, scroll angle, inlet angle and exit angle is investigated using orthogonal design approach. </span></span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">The impeller inlet angle, exit angle and bias angle </span><span style="font-family:Verdana;">are found to exert the greatest influence on the overall performance of a torque converter, with two flow area factors being considered, namely 17% and 20%. Then, RSM together with central composite design (CCD) method is used to in-depth evaluate the interaction effect of the three key parameters on converter performance. The results demonstrate that </span><span style="font-family:Verdana;">impeller exit angle has the strongest impact on peak efficiency</span><span style="font-family:Verdana;">, with larger angles yielding the most favorable results. The stall torque ratio maximization is attainable with the increase of impeller bias angle and inlet angle together with smaller exit angle. In the end, </span><span style="font-family:Verdana;">an optimized design for the impeller geometry is obtained with stall torque ratio and peak efficiency increased by 1.62% and 1.1%, respectively.</span><span style="font-family:Verdana;"> The new optimization method can be used as a reference for performance enhancement in the design process of impeller geometry for an automotive torque converter.</span></span></span></span>
文摘The MBTI(Myers-Briggs Type Indicator)remains widely used in many counseling applications despite extensive criticism of its basic nature and psychometric properties.The present study was designed to examine specifically the accuracy of the claimed minimal influence of social desirability on Form G of the MBTI.Undergraduate students(n=26)judged the desirability of each item option of Form G,which was compared across the 60 item pairs in which both options were scored.The rated values were approximately equal for two domains,while J and E item options were judged to be more desirable than their P and I paired response options.A second study(n=52)evaluated the social desirability of the 16 MBTI type descriptors,finding most descriptions to be above the neutral range in desirability.These results suggest that stylistic responding contaminates MBTI profiles and interpretative material.Consequently,users should consider alternative measures and at the very least,take great care in interpreting the MBTI because of its flawed structure.
文摘Cashew processing in Côte d’Ivoire focuses only on the cashew nut, to the detriment of the apple. Only a very small proportion of the apple is processed into juice. The aim of this work is to enhance the value of cashew apples by transforming them into jam. Specifically, the aim was first to characterize the sensory properties of cashew apple jam formulations using baobab powder as a source of pectin and then to optimise the formulations. A Box-Behken design with pH, Sugar, and Baobab as factors was used to model and characterize the jam sensory descriptors, and a multivariate analysis with SensomineR was used to characterize the jam formulations. The desirability function was used to optimise the formulations. The results show globally significant regressions at the 0.05 threshold for the sensory descriptors Gelling, Brilliance, Smell, Sweetness, and (-)Astringency, with the exception of (-)Salinity. The R2 coefficients are greater than 80%. The factors studied could have effects on the sensory descriptors of cashew jam formulations. The Baobab had the main effect on the gelling, smell, and astringency of the jams. Brilliance depended on the added sugar. A product effect (p < 0.001) was observed for the descriptors Smell, Gelling, Brilliance, and Sweetness, as these allowed the panelists to find differences between the formulations. Optimum jam formulation can be achieved with 51.56% sugar and 2.12% Baobab at a pH of 3.15. Cashew apple jam using Baobab offers opportunities to add value to apples that have long been abandoned in the field. It would be important to find conditions for prolonged storage of this jam.
基金Funded by the Deep Underground National Science&Technology Major Project gram of China(No.2024ZD1003704)the National Natural Science Foundation of China(Nos.51834001 and 52374111)。
文摘The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increases with cement sand ratio(CSR),slurry concentration(SC),and curing age(CA),while flow resistance(FR)increases with SC and backfill flow rate(BFR),and decreases with CSR.Then the regression models of UCS and FR as response values were established through RSM.Multi-factor interaction found that CSR-CA impacted UCS most,while SC-BFR impacted FR most.By introducing the desirability function,the optimal backfill parameters were obtained based on RSM-DF(CSR is 1:6.25,SC is 69%,CA is 11.5 d,and BFR is 90 m^(3)/h),showing close results of Design Expert and high reliability for optimization.For a copper mine in China,RSM-DF optimization will reduce cement consumption by 4758 t per year,increase tailings consumption by about 6700 t,and reduce CO_(2)emission by about 4758 t.Thus,RSM-DF provides a new approach for backfill parameters optimization,which has important theoretical and practical values.
文摘From international student to professor,Tripathi Mani shares his thoughts on Chinese and Indian cultures and the beneficial exchanges between them.TRIPATHI Vivek Mani first learned about China from bedtime stories told by his father,a Sanskrit teacher in rural Bihar,a state in east India.Many of the stories were about the Chinese monk Xuanzang’s adventures during his long journey to India to find Buddhist scriptures.They kindled the young boy’s interest in China and the desire to visit it one day.
基金National Natural Science Foundation of China under Grant No.12005062(SS).National Natural Science Foundation of China under Grant No.11974366(HF).National Natural Science Foundation of China under Grant No.U1632135(HY)Fundamental Research Funds for the Central Universities,China(HF)。
文摘Suppressing the coffee ring effect(CRE)of an aqueous suspension through manipulation without affecting the remaining deposit is highly desirable for practical applications;however,this is extremely challenging.Here,we demonstrate CRE suppression with undetectable disturbance of the deposit on carbon-based surfaces.This was achieved by adding ammonium bicarbonate(NH4HCO_(3)),which benefits from the dissociation of NH_(4)HCO_(3) to produce NH_(4)^(+),as well as its decomposition into NH_(3) and CO_(2) molecules.Surprisingly,NH_(4)^(+) can also function as Na^(+)/K^(+)to suppress the CRE through cation interactions,although its hydrate state is only partially positively charged.Moreover,we successfully applied this approach to enhance the morphology,resistance,and color uniformity of deposits of graphene oxide quantum dots,conductive inks,and organic dyes,respectively.This study provides a practical strategy for improving the performance of fabricated devices and paves the way for the development of high-accuracy manufacturing techniques in diverse industries.
文摘This paper addresses the time-varying formation-containment(FC) problem for nonholonomic multi-agent systems with a desired trajectory constraint, where only the leaders can acquire information about the desired trajectory. Input the fixed time-varying formation template to the leader and start executing, this process also needs to track the desired trajectory, and the follower needs to converge to the convex hull that the leader crosses. Firstly, the dynamic models of nonholonomic systems are linearized to second-order dynamics. Then, based on the desired trajectory and formation template, the FC control protocols are proposed. Sufficient conditions to achieve FC are introduced and an algorithm is proposed to resolve the control parameters by solving an algebraic Riccati equation. The system is demonstrated to achieve FC, with the average position and velocity of the leaders converging asymptotically to the desired trajectory. Finally, the theoretical achievements are verified in simulations by a multi-agent system composed of virtual human individuals.
文摘Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to study their physical,chemical,and mechanical properties.In this context,the present study relates to the extraction,characterization,and optimization of Typha angustata L.stem fibers.For this purpose,desirability functions and response surface methodology were applied to simultaneously optimize the diameter(D),linear density(LD);yield(Y),lignin fraction(L),and tenacity(T)of Typha stem fibers.Typha stems have been subjected to both alkali(NaOH)and enzymatic(pectinex ultra-SPL)treatments.Three levels of process variables including enzyme concentration(10,15,and 20 ml/L)and treatment duration(10,15,and 20 days)were used to design the experiments according to the factorial design.Experimental results were examined by analysis of variance and fitted to second order polynomial model using multiple regression analysis.The Derringer’s desirability function released that the values of process variables generating optimized diameter,linear density,yield,lignin ratio and tenacity are 20 ml/L and 20 days for concentration of pectinex ultra-SPL enzyme and treatment duration,respectively.Confirmation was performed and high degree of correlation was found between the experimental and statistical values.Moreover,the morphological structure has been investigated by the scanning electron microscope,showing a crenelated structure of ultimate fiber bundles of cellulose composing the Typha fiber.Compared to Typha stem non-treated fibers(TSNTF),Typha stem combined treated fibers(TSCTF),brings to improve mechanical properties.This change in mechanical properties is affected by modifying the fiber structure showing alpha cellulose of(66.86%)and lignin ratio of(10.83%)with a crystallinity index of(58.47%).
基金supported by the National Key R&D Program of China(No.2022YFA1502904)the National Natural Science Foundation of China(Nos.22275178 and 22002148)the Fundamental Research Funds for the Central Universities(Nos.JUSRP123013 and JUSRP123015)。
文摘The carbon dioxide(CO_(2))reduction process involves complex protonation,making the resulting product often unpredictable.To achieve the desired product,it is crucial to manipulate the reaction steps.Herein,we build the metal atom pair sites for selective CO_(2)photoreduction into methane.As a prototype,Ni atom pair sites loaded on the Mo S_(2)nanosheets were synthesized and verified by highresolution transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS)and X-rayabsorption near edge structure spectra(XANES).In-situ Fourier transform infrared spectroscopy(FTIR)monitors the*CHO group,a crucial intermediate in CH_(4)production,during CO_(2)photoreduction on the Ni-Mo S_(2)nanosheets,whereas this monitoring is not observed for the Mo S_(2)nanosheets.Also,theoretical calculations disclose that over the Ni-Mo S_(2)nanosheet slab,the formation energy of*CHO intermediates is determined to be lower(0.585 e V)than the desorption energy of*CO intermediates for CO production(0.64 e V),implying the higher selectivity of CH_(4)production.
