This study examines the depth of information regarding Female Genital Mutilation (FGM)/Female Cutting (FC) present in US medical textbooks. According to Klein et al. (2018) [1], despite substantial attention regarding...This study examines the depth of information regarding Female Genital Mutilation (FGM)/Female Cutting (FC) present in US medical textbooks. According to Klein et al. (2018) [1], despite substantial attention regarding the effects of FGM, this practice is still ongoing all over the world. Healthcare providers are very important actors who need to understand FGM in order to provide care to girls and women subjected to it, but the small amount of existing work in this area shows a low level of knowledge and training about FGM/FC among U.S. physicians. The Center for Disease Control and Prevention (CDC) first published the estimated number of girls at risk of FGM/FC in the U.S. to be about 168,000 in 1997;that number had increased to 513,000 girls in the US by 2012 (according to Goldberg et al.) In this study, a small sample of medical textbooks were analyzed for the degree to which the textbooks include information regarding FGM/FC. The results of this study show that US medical textbooks do not include information regarding FGM/FC, suggesting that most medical providers don’t have knowledge and training about FGM/FC. The inadequate information on FGM/FC in medical textbooks reflects a culturally biased lack of recognition of the number of girls and women affected in the US. This maintains an ongoing pattern of silence that reinforces gender inequality. Considering the inadequate information covered in US medical textbooks on FGM/FC, and the concordant lack of provider training to provide advice and care to affected girls and women, incorrect and missed diagnoses may lead to harm to victims of FGM/FC. Providers would be better equipped to care for women and girls if their medical training included information regarding FGM/FC.展开更多
Automated identification and tracking of mesoscale ocean eddies has recently become one research hotspot in physical oceanography. Several methods have been developed and applied to survey the general kinetic and geom...Automated identification and tracking of mesoscale ocean eddies has recently become one research hotspot in physical oceanography. Several methods have been developed and applied to survey the general kinetic and geometric characteristics of the ocean eddies in the South China Sea(SCS). However, very few studies attempt to examine eddies' internal evolution processes. In this study, we reported a hybrid method to trace eddies' propagation in the SCS based on their internal structures, which are characterized by eddy centers, footprint borders, and composite borders. Eddy identification and tracking results were represented by a GIS-based spatiotemporal model. Information on instant states, dynamic evolution processes, and events of disappearance, reappearance, split, and mergence is stored in a GIS database. Results were validated by comparing against the ten Dongsha Cyclonic Eddies(DCEs) and the three long-lived anticyclonic eddies(ACEs) in the northern SCS, which were reported in previous literature. Our study confirmed the development of these eddies. Furthermore, we found more DCE-like and ACE-like eddies in these areas from 2005 to 2012 in our database. Spatial distribution analysis of disappearing, reappearing, splitting, and merging activities shows that eddies in the SCS tend to cluster to the northwest of Luzon Island, southwest of Luzon Strait, and around the marginal sea of Vietnam. Kuroshio intrusions and the complex sea floor topography in these areas are the possible factors that lead to these spatial clusters.展开更多
Niobium doped Zincoxide nanoparticles has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, IR Spectroscopy, SEM, XRD, ICPMS and EDAX data. The UV-Visible spectroscopy resul...Niobium doped Zincoxide nanoparticles has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, IR Spectroscopy, SEM, XRD, ICPMS and EDAX data. The UV-Visible spectroscopy result reveals that the band gap energy of ZnO/Nb2O5 nanoparticles to be 3.8 eV. The XRD results show that the crystallite size is to be 31.9 nm. The ICPMS data indicate the presence of 3,3461,328 counts of 93 Nb and 577,906,390 counts of 66 Zn. An improvement in the photocatalytic degradation of Indigocarmine dye (IC) in comparison to commercially available pure ZnO was observed. The photodegradation efficiency for ZnO/Nb2O5 and ZnO were found to be 97.4% and 52.1% respectively. The enhancement in photocatalytic activity of ZnO/ Nb2O5 was ascribed to the extended light absorption range and suppression of electron hole pair recombination upon Nb loading. The antibacterial activity of ZnO/Nb2O5 nanoparticles was investigated. These particles were shown to have an effective bactericide.展开更多
Office Information Systems is a field of computer science concerned with studying offices and developing technologies to support office workers. The field initiated in 1982 suffered a gradual demise by 2004. However, ...Office Information Systems is a field of computer science concerned with studying offices and developing technologies to support office workers. The field initiated in 1982 suffered a gradual demise by 2004. However, many of the themes and issues that motivated the discipline continue to exist today. Office workers continue to struggle with routine tasks that do not have adequate IT support and the problem is worse for mobile employees. In this paper we provide a retrospective on OIS technologies with the hope of stimulating interest in the discipline and addressing the needs of office workers worldwide. The evolution of office technologies and a detailed discussion of past research are provided. The discussion shows that technology support for office workers is still inadequate. The paper suggests a technology vision and architecture to motivate researchers and identifies challenges for future research.展开更多
Firstly an overview of the potential impact on work-in-process (WIP) and lead time is provided when transfer lot sizes are undifferentiated from processing lot sizes. Simple performance examples are compared to thos...Firstly an overview of the potential impact on work-in-process (WIP) and lead time is provided when transfer lot sizes are undifferentiated from processing lot sizes. Simple performance examples are compared to those from a shop with one-piece transfer lots. Next, a mathematical programming model for minimizing lead time in the mixed-model job shop is presented, in which one-piece transfer lots are used. Key factors affecting lead time are found by analyzing the sum of the longest setup time of individual items among the shared processes (SLST) and the longest processing time of individual items among processes (LPT). And lead time can be minimized by cutting down the SLST and LPT. Reduction of the SLST is described as a traveling salesman problem (TSP), and the minimum of the SLST is solved through job shop scheduling. Removing the bottleneck and leveling the production line optimize the LPT. If the number of items produced is small, the routings are relatively short, and items and facilities are changed infrequently, the optimal schedule will remain valid. Finally a brief example serves to illustrate the method.展开更多
Chromium oxide nanoparticles were synthesized by the reduction of potassium dichromate solution with Mukia Maderaspatana plant extract. In electrochemical methods, Cr2O3 nanoparticles were synthesized by two ways, usi...Chromium oxide nanoparticles were synthesized by the reduction of potassium dichromate solution with Mukia Maderaspatana plant extract. In electrochemical methods, Cr2O3 nanoparticles were synthesized by two ways, using platinum (Pt) electrodes and K2Cr2O7 solution with H2SO4 as medium in the first case. And chromium doped platinum electrode (Pt/Cr) in presence of NaHCO3 solution in second case. The resulting Cr2O3 nanoparticles were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), UV-VIS absorption and Fourier-transform infrared (FTIR) spectroscopy. The enhancing influence of Cr2O3 nanoparticles as a catalyst for the decomposition of KMnO4 has been studied. The antibacterial effect of Cr2O3 nanoparticles against E. coli was investigated. These particles were shown to have an effective bactericide.展开更多
Purpose: This study explored the relationship between mental toughness and college basketball performance, specifically examining possible moderating variables (gender and starting status). Methods: Male and fema...Purpose: This study explored the relationship between mental toughness and college basketball performance, specifically examining possible moderating variables (gender and starting status). Methods: Male and female (n = 197) college basketball players completed the Psychological Performance Inventory-Alternative (PPI-A), a measure of characteristics and skills consistent with mental toughness, and the PERK an objective measure of basketball performance. Results: Findings suggest that basketball performance can be partially predicted by mental toughness and starting status. Males reported greater mental toughness than females. Starters and nonstarters did not differ in mental toughness. Moderated hierarchical regression analysis indicated that mental toughness was related to performance for male players as both a main effect and interaction with starter status. For female players, in contrast, starter status was the only significant predictor of performance. Practitioners are encouraged to foster the psychological skills associated with mental toughness in females and non-starters in basketball. Conclusion: Discussion of the PPI-A as a measure of mental toughness and suggestions for its improvement are explored. A need exists for additional research on mental toughness and objective performance, as performance enhancement is a major impetus for research on mental toughness. Copyright @ 2012, Shanghai University of Sport. Production and hosting by Elsevier B.V. All rights reserved.展开更多
Hydroxyl radicals, superoxide anions and nitricoxide radicals are reactive species that can attack biomolecules such as DNA, lipids and proteins to cause many lifestyle-related diseases including hypertension and phot...Hydroxyl radicals, superoxide anions and nitricoxide radicals are reactive species that can attack biomolecules such as DNA, lipids and proteins to cause many lifestyle-related diseases including hypertension and photoaging. This study reports the synthesis of new copper-pyridoxine and iron-pyridoxine complexes. The complexes have been synthesized and characterized by molar conductances, IR, UV-Visible, mass spectrometry, melting points and magnetic moment datas. The molecular formula of the complex is found to be Fe(py ^-)2Cl.H2O. The pyH/pyligand is coordinated to copper and iron through N atom of the pyridine ring and O atom of 5'-CH2OH group. The Fe(III) complex is found to be paramagnetic with one unpaired electron. The antioxidant activities of the free ligand and its complexes were determined in vitro.展开更多
In this study, linoleic acid (LA) was encapsulated in the presence or absence of quercetin into a dual polymer system of whey protein and kappa-carrageenan using power ultrasound. Atomic Force Microscopy (AFM) and Flo...In this study, linoleic acid (LA) was encapsulated in the presence or absence of quercetin into a dual polymer system of whey protein and kappa-carrageenan using power ultrasound. Atomic Force Microscopy (AFM) and FlowCam imaging technology were used for imaging and size determination of nano-and micro-capsules. Differential scanning calorimeter (DSC) was used to determine the glass transition temperature (Tg) of the freeze-dried nanocapsules. In order to examine the effect of water activity (aw) on the release profile of the encapsulated LA, the nanocapsules were equilibrated over saturated salt solution conditions corresponding to the range of aw between 0.333 and 0.769 in evacuated desiccators at room temperature. Gravimetric measurements of the steady state linoleic acid (LA) contents were conducted. The anti-oxidant activity of quercetin and the stability of encapsulated LA toward long term and thermally induced rancidity was investigated. The capsules were in the nanosize regime and 83% of the LA was effectively encapsulated. Furthermore, at aw of 0.764, the highest percentage of LA (74%) was released from the expelling nanocapsules. Quercetin was found to exhibit protective antioxidant effect against time-dependent oxidation and thermally induced rancidity of LA. Water activity values of 0.662 and 0.764 provided ideal humidity and pressure conditions for sustained release of nanoencapsulated LA at room temperature.展开更多
Oxidations of piperazine, 1-methylpiperazine and 1-ethylpiperazine by bromamine-T (BAT) in buffered acidic medium have been kinetically studied at 303 K. The reaction shows a first-order dependence of the rate each on...Oxidations of piperazine, 1-methylpiperazine and 1-ethylpiperazine by bromamine-T (BAT) in buffered acidic medium have been kinetically studied at 303 K. The reaction shows a first-order dependence of the rate each on [BAT]0 and [piperazine]0, and an inverse fractional-order dependence on [H+]. The additions of halide ions and the reduction product of BAT, p-toluenesulfonamide, have no effect on the reaction rate. The variation of ionic strength of the solvent medium has no influence on the rate. Activation parameters have been evaluated from the Arrhenius and Eyring plots. A common mechanism consistent with the kinetic data has been proposed for all piperazines. The protonation constants of substrates have been evaluated. The Hammett linear free-energy relationship has been observed for the reaction with ρ = ?0.5 indicating that the electron-donating groups enhance the reaction rate by stabilizing the transition state. An isokinetic relationship observed shows β = 368 K indicating the dominance of enthalpy factors on the reaction rate.展开更多
The field of information systems has historically suffered from a pre-dominance of behavioral approaches. As a result, it is not surprising that in spite of decades of research, dozens of conferences and journals and ...The field of information systems has historically suffered from a pre-dominance of behavioral approaches. As a result, it is not surprising that in spite of decades of research, dozens of conferences and journals and thousands of researchers, very few breakthroughs have been achieved. This paper advocates a technical approach that focuses on improving existing systems in organizations by viewing them from the point of roles i.e. functions fulfilled by IS in organizations. These are understood as: 1) supporting operations, 2) providing information, 3) supporting decision making, 4) providing knowledge, 5) supporting knowledge and clerical work, and 6) supporting organizational design. It is generally agreed that the field’s understanding of fulfilling roles “1”, “2”, “3” and “6” is mature while understanding of areas “3” (for unstructured decisions), “4”, and “5” are still incomplete. The challenges in these areas are difficult problems that we refer to as grand challenges and discuss in this paper.展开更多
Information security often involves the development and application of so</span><span style="font-family:Verdana;">phisticated software to protect sensitive information stored in corporate</sp...Information security often involves the development and application of so</span><span style="font-family:Verdana;">phisticated software to protect sensitive information stored in corporate</span><span style="font-family:Verdana;"> computers. Yet, in this example of corporate espionage, a clever person, a cellphone and some readily available software were all it took to crack through one company’s advanced security barriers. By reading this article it is hoped that employees at all levels of an organization’s hierarchy will become more aware of—and recognize—how: 1) bits and pieces of seemingly harmless and easy-to-acquire information can be used for sinister purposes;2) building rapport and trust with a person can make them more likely to become unknowing co-conspirators in a devious undertaking;and 3) how one must be constantly alert not to give out information without carefully considering the authenticity and justification of the source requesting it.展开更多
Laser additive manufacturing(LAM) of tungsten carbide metal matrix composites(MMCs) has been evaluated for surface modification of hot die forming tools,cutting edges,glass tooling,extrusion mandrels,and other abrasiv...Laser additive manufacturing(LAM) of tungsten carbide metal matrix composites(MMCs) has been evaluated for surface modification of hot die forming tools,cutting edges,glass tooling,extrusion mandrels,and other abrasive wear applications.This work focuses on transitions from tool steels to MMCs through a single pass laser powder deposition operation.Issues related to the application of various metal powders and carbides used include surface hardness,porosity,cracking,and dilution.These issues along with factory results that were obtained during this project are discussed.展开更多
The ever-increasing dependence on electrical power has posed more challenges to power system engineers to deliver secure, stable, and sustained energy to electricity consumers. Due to the increasing occurrence of shor...The ever-increasing dependence on electrical power has posed more challenges to power system engineers to deliver secure, stable, and sustained energy to electricity consumers. Due to the increasing occurrence of short-and long-term power interruptions in the power system, the need for a systematic approach to mitigate the negative impacts of such events is further manifested. Self-healing and its control strategies are generally accepted as a solution for this concern. Due to the importance of self-healing subject in power distribution systems, this paper conducts a comprehensive literature review on self-healing from existing published papers. The concept of self-healing is briefly described, and the published papers in this area are categorized based on key factors such as self-healing optimization goals, available control actions, and solution methods. Some proficient techniques adopted for self-healing improvements are also classified to have a better comparison and selection of methods for new investigators. Moreover, future research directions that need to be explored to improve self-healing operations in modern power distribution systems are investigated and described at the end of this paper.展开更多
Mobile internet and wireless communication technologies have produced unprecedented location-aware data.Such big geospatial data can be used as a proxy measure of the‘digital footprints’left by us on the planet and ...Mobile internet and wireless communication technologies have produced unprecedented location-aware data.Such big geospatial data can be used as a proxy measure of the‘digital footprints’left by us on the planet and provide a valuable opportunity to understand the dynamic and short-term human disturbance on the nature at fine scales.This study investigated the spatiotemporal variations of human’s digital footprints on the Qinghai-Tibet Plateau using smartphone-users-generated Tencent’s location request data.The results showed that human’s digital footprints cover less than 5%of Qinghai and Tibet,exhibiting either a U-shaped or an N-shaped temporal change pattern during the major festivals.Spatial changes of the digital footprints manifested a transition process from dispersion to concentration in Xining and Lhasa.Human disturbance assessment of seven large nature reserves on the plateau showed that the Qinghai Lake is the most disturbed one as shown by 14.6%of its area is stained with human digital footprints and the areal average of footprint intensity is 1.59,and the disturbance was significantly escalated during the National Day holiday.By contrast,the Qangtang and Hoh Xil are the least affected nature reserves with the two indices less than 1%and 0.1,respectively.展开更多
This study presented a quantitative comparison of cockpit and doline karst by examining the numbers and characteristics of typical types of landform entities that are developed in Guilin(Guangxi, China), La Alianza...This study presented a quantitative comparison of cockpit and doline karst by examining the numbers and characteristics of typical types of landform entities that are developed in Guilin(Guangxi, China), La Alianza(PR, USA), Avalton(KY, USA), and Oolitic(IN, USA). Five types of landform entities were defined: isolated hill(IH), clustered hills(CHs), isolated sinkhole(IS), clustered sinkholes(CSs), and clustered hills with sinkholes(CHSs). An algorithm was developed to automatically identify these types of landform entities by examining the contour lines on topographic maps of two cockpit karst areas(Guilin and La Alianza) and two doline karst areas(Oolitic and Avalton). Within each specific study area, the CHSs is the least developed type yet with a larger size and higher relief. The IH and IS entities are smaller in size, lower in relief, and outnumber their clustered counterparts. The total numbers of these types of entities are quite different in cockpit and doline karst areas. Doline karst is characterized by more negative(IS and CSs) than positive(IH and IHs) landforms and vice versa for cockpit karst. For example, the Guilin study area has 1192 positive landform entities in total, which occupy 9.81% of the total study area. It has only 622 negative landform entities occupying only 3.91% of the total study area. By contrast, the doline karst in Oolitic has 130 negative while only 10 positive landform entities. The positive and negative landforms in Oolitic occupy 12.68% and 2.61% of the total study area, respectively. Furthermore, average relief and slope of the landform entities are much higher and steeper in the cockpit karst than the doline karst areas. For instance, the average slope of CHs in Alvaton is 3.90 degrees while it is 19.78 degrees in La Alianza. The average relief of CSs is 4.07 m and 34.29 m in Oolitic and Guilin respectively. Such a difference within a specific area or between the cockpit and doline karst may reveal different controls on the development of karst landscape.展开更多
Location-aware big data from social media have been widely used to quantitatively characterize natural disasters and disaster-induced losses.It is not clear how human activities collectively respond to a disaster.In t...Location-aware big data from social media have been widely used to quantitatively characterize natural disasters and disaster-induced losses.It is not clear how human activities collectively respond to a disaster.In this study,we examined the collective human activities in response to Typhoon Hato at multi spatial scales using aggregated location request data.We proposed a Multilevel Abrupt Changes Detection(MACD)methodological framework to detect and characterize the abrupt changes in location requests in response to Typhoon Hato.Results show that,at the grid level,most anomaly grids were located within a radius of 53 km around the typhoon trajectory.At the city level,there are significant spatial difference in terms of the human activity recovery duration(230 h on average).At the subnational level,the absolute magnitude of abrupt location request changes is strongly correlated with the typhoon-induced economic losses and the population affected.展开更多
Two stochastic models are derived for a susceptible-infectious-susceptible epidemic spreading through a metapopulation: a continuous time Markov chain (CTMC) model and an It6 stochastic differential equation (SDE...Two stochastic models are derived for a susceptible-infectious-susceptible epidemic spreading through a metapopulation: a continuous time Markov chain (CTMC) model and an It6 stochastic differential equation (SDE) model. The stochastic models are numerically compared. Close agreement suggests that computationally intense CTMC simulations can be approximated by simpler SDE simulations. Differential equations for the moments of the SDE probability distribution are also derived, the steady states are solved numerically using a moment closure technique, and these results are compared to simulations. The moment closure technique only coarsely approximates simulation results. The effect of model parameters on stability of the disease-free equilibrium is also numerically investigated.展开更多
文摘This study examines the depth of information regarding Female Genital Mutilation (FGM)/Female Cutting (FC) present in US medical textbooks. According to Klein et al. (2018) [1], despite substantial attention regarding the effects of FGM, this practice is still ongoing all over the world. Healthcare providers are very important actors who need to understand FGM in order to provide care to girls and women subjected to it, but the small amount of existing work in this area shows a low level of knowledge and training about FGM/FC among U.S. physicians. The Center for Disease Control and Prevention (CDC) first published the estimated number of girls at risk of FGM/FC in the U.S. to be about 168,000 in 1997;that number had increased to 513,000 girls in the US by 2012 (according to Goldberg et al.) In this study, a small sample of medical textbooks were analyzed for the degree to which the textbooks include information regarding FGM/FC. The results of this study show that US medical textbooks do not include information regarding FGM/FC, suggesting that most medical providers don’t have knowledge and training about FGM/FC. The inadequate information on FGM/FC in medical textbooks reflects a culturally biased lack of recognition of the number of girls and women affected in the US. This maintains an ongoing pattern of silence that reinforces gender inequality. Considering the inadequate information covered in US medical textbooks on FGM/FC, and the concordant lack of provider training to provide advice and care to affected girls and women, incorrect and missed diagnoses may lead to harm to victims of FGM/FC. Providers would be better equipped to care for women and girls if their medical training included information regarding FGM/FC.
基金The National Science Foundation of China under contract Nos 41071250 and 41371378the Innovation Projects of the State Key Laboratory of Resource and Environment Information System,Chinese Academy of Sciences,under contract No.088RA500TA
文摘Automated identification and tracking of mesoscale ocean eddies has recently become one research hotspot in physical oceanography. Several methods have been developed and applied to survey the general kinetic and geometric characteristics of the ocean eddies in the South China Sea(SCS). However, very few studies attempt to examine eddies' internal evolution processes. In this study, we reported a hybrid method to trace eddies' propagation in the SCS based on their internal structures, which are characterized by eddy centers, footprint borders, and composite borders. Eddy identification and tracking results were represented by a GIS-based spatiotemporal model. Information on instant states, dynamic evolution processes, and events of disappearance, reappearance, split, and mergence is stored in a GIS database. Results were validated by comparing against the ten Dongsha Cyclonic Eddies(DCEs) and the three long-lived anticyclonic eddies(ACEs) in the northern SCS, which were reported in previous literature. Our study confirmed the development of these eddies. Furthermore, we found more DCE-like and ACE-like eddies in these areas from 2005 to 2012 in our database. Spatial distribution analysis of disappearing, reappearing, splitting, and merging activities shows that eddies in the SCS tend to cluster to the northwest of Luzon Island, southwest of Luzon Strait, and around the marginal sea of Vietnam. Kuroshio intrusions and the complex sea floor topography in these areas are the possible factors that lead to these spatial clusters.
文摘Niobium doped Zincoxide nanoparticles has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, IR Spectroscopy, SEM, XRD, ICPMS and EDAX data. The UV-Visible spectroscopy result reveals that the band gap energy of ZnO/Nb2O5 nanoparticles to be 3.8 eV. The XRD results show that the crystallite size is to be 31.9 nm. The ICPMS data indicate the presence of 3,3461,328 counts of 93 Nb and 577,906,390 counts of 66 Zn. An improvement in the photocatalytic degradation of Indigocarmine dye (IC) in comparison to commercially available pure ZnO was observed. The photodegradation efficiency for ZnO/Nb2O5 and ZnO were found to be 97.4% and 52.1% respectively. The enhancement in photocatalytic activity of ZnO/ Nb2O5 was ascribed to the extended light absorption range and suppression of electron hole pair recombination upon Nb loading. The antibacterial activity of ZnO/Nb2O5 nanoparticles was investigated. These particles were shown to have an effective bactericide.
文摘Office Information Systems is a field of computer science concerned with studying offices and developing technologies to support office workers. The field initiated in 1982 suffered a gradual demise by 2004. However, many of the themes and issues that motivated the discipline continue to exist today. Office workers continue to struggle with routine tasks that do not have adequate IT support and the problem is worse for mobile employees. In this paper we provide a retrospective on OIS technologies with the hope of stimulating interest in the discipline and addressing the needs of office workers worldwide. The evolution of office technologies and a detailed discussion of past research are provided. The discussion shows that technology support for office workers is still inadequate. The paper suggests a technology vision and architecture to motivate researchers and identifies challenges for future research.
基金This project is supported by National Natural Science Foundation of China (No.70372062, No.70572044)Program for New Century Excellent Talents in University of China (No.NCET-04-0240).
文摘Firstly an overview of the potential impact on work-in-process (WIP) and lead time is provided when transfer lot sizes are undifferentiated from processing lot sizes. Simple performance examples are compared to those from a shop with one-piece transfer lots. Next, a mathematical programming model for minimizing lead time in the mixed-model job shop is presented, in which one-piece transfer lots are used. Key factors affecting lead time are found by analyzing the sum of the longest setup time of individual items among the shared processes (SLST) and the longest processing time of individual items among processes (LPT). And lead time can be minimized by cutting down the SLST and LPT. Reduction of the SLST is described as a traveling salesman problem (TSP), and the minimum of the SLST is solved through job shop scheduling. Removing the bottleneck and leveling the production line optimize the LPT. If the number of items produced is small, the routings are relatively short, and items and facilities are changed infrequently, the optimal schedule will remain valid. Finally a brief example serves to illustrate the method.
文摘Chromium oxide nanoparticles were synthesized by the reduction of potassium dichromate solution with Mukia Maderaspatana plant extract. In electrochemical methods, Cr2O3 nanoparticles were synthesized by two ways, using platinum (Pt) electrodes and K2Cr2O7 solution with H2SO4 as medium in the first case. And chromium doped platinum electrode (Pt/Cr) in presence of NaHCO3 solution in second case. The resulting Cr2O3 nanoparticles were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), UV-VIS absorption and Fourier-transform infrared (FTIR) spectroscopy. The enhancing influence of Cr2O3 nanoparticles as a catalyst for the decomposition of KMnO4 has been studied. The antibacterial effect of Cr2O3 nanoparticles against E. coli was investigated. These particles were shown to have an effective bactericide.
文摘Purpose: This study explored the relationship between mental toughness and college basketball performance, specifically examining possible moderating variables (gender and starting status). Methods: Male and female (n = 197) college basketball players completed the Psychological Performance Inventory-Alternative (PPI-A), a measure of characteristics and skills consistent with mental toughness, and the PERK an objective measure of basketball performance. Results: Findings suggest that basketball performance can be partially predicted by mental toughness and starting status. Males reported greater mental toughness than females. Starters and nonstarters did not differ in mental toughness. Moderated hierarchical regression analysis indicated that mental toughness was related to performance for male players as both a main effect and interaction with starter status. For female players, in contrast, starter status was the only significant predictor of performance. Practitioners are encouraged to foster the psychological skills associated with mental toughness in females and non-starters in basketball. Conclusion: Discussion of the PPI-A as a measure of mental toughness and suggestions for its improvement are explored. A need exists for additional research on mental toughness and objective performance, as performance enhancement is a major impetus for research on mental toughness. Copyright @ 2012, Shanghai University of Sport. Production and hosting by Elsevier B.V. All rights reserved.
文摘Hydroxyl radicals, superoxide anions and nitricoxide radicals are reactive species that can attack biomolecules such as DNA, lipids and proteins to cause many lifestyle-related diseases including hypertension and photoaging. This study reports the synthesis of new copper-pyridoxine and iron-pyridoxine complexes. The complexes have been synthesized and characterized by molar conductances, IR, UV-Visible, mass spectrometry, melting points and magnetic moment datas. The molecular formula of the complex is found to be Fe(py ^-)2Cl.H2O. The pyH/pyligand is coordinated to copper and iron through N atom of the pyridine ring and O atom of 5'-CH2OH group. The Fe(III) complex is found to be paramagnetic with one unpaired electron. The antioxidant activities of the free ligand and its complexes were determined in vitro.
文摘In this study, linoleic acid (LA) was encapsulated in the presence or absence of quercetin into a dual polymer system of whey protein and kappa-carrageenan using power ultrasound. Atomic Force Microscopy (AFM) and FlowCam imaging technology were used for imaging and size determination of nano-and micro-capsules. Differential scanning calorimeter (DSC) was used to determine the glass transition temperature (Tg) of the freeze-dried nanocapsules. In order to examine the effect of water activity (aw) on the release profile of the encapsulated LA, the nanocapsules were equilibrated over saturated salt solution conditions corresponding to the range of aw between 0.333 and 0.769 in evacuated desiccators at room temperature. Gravimetric measurements of the steady state linoleic acid (LA) contents were conducted. The anti-oxidant activity of quercetin and the stability of encapsulated LA toward long term and thermally induced rancidity was investigated. The capsules were in the nanosize regime and 83% of the LA was effectively encapsulated. Furthermore, at aw of 0.764, the highest percentage of LA (74%) was released from the expelling nanocapsules. Quercetin was found to exhibit protective antioxidant effect against time-dependent oxidation and thermally induced rancidity of LA. Water activity values of 0.662 and 0.764 provided ideal humidity and pressure conditions for sustained release of nanoencapsulated LA at room temperature.
文摘Oxidations of piperazine, 1-methylpiperazine and 1-ethylpiperazine by bromamine-T (BAT) in buffered acidic medium have been kinetically studied at 303 K. The reaction shows a first-order dependence of the rate each on [BAT]0 and [piperazine]0, and an inverse fractional-order dependence on [H+]. The additions of halide ions and the reduction product of BAT, p-toluenesulfonamide, have no effect on the reaction rate. The variation of ionic strength of the solvent medium has no influence on the rate. Activation parameters have been evaluated from the Arrhenius and Eyring plots. A common mechanism consistent with the kinetic data has been proposed for all piperazines. The protonation constants of substrates have been evaluated. The Hammett linear free-energy relationship has been observed for the reaction with ρ = ?0.5 indicating that the electron-donating groups enhance the reaction rate by stabilizing the transition state. An isokinetic relationship observed shows β = 368 K indicating the dominance of enthalpy factors on the reaction rate.
文摘The field of information systems has historically suffered from a pre-dominance of behavioral approaches. As a result, it is not surprising that in spite of decades of research, dozens of conferences and journals and thousands of researchers, very few breakthroughs have been achieved. This paper advocates a technical approach that focuses on improving existing systems in organizations by viewing them from the point of roles i.e. functions fulfilled by IS in organizations. These are understood as: 1) supporting operations, 2) providing information, 3) supporting decision making, 4) providing knowledge, 5) supporting knowledge and clerical work, and 6) supporting organizational design. It is generally agreed that the field’s understanding of fulfilling roles “1”, “2”, “3” and “6” is mature while understanding of areas “3” (for unstructured decisions), “4”, and “5” are still incomplete. The challenges in these areas are difficult problems that we refer to as grand challenges and discuss in this paper.
文摘Information security often involves the development and application of so</span><span style="font-family:Verdana;">phisticated software to protect sensitive information stored in corporate</span><span style="font-family:Verdana;"> computers. Yet, in this example of corporate espionage, a clever person, a cellphone and some readily available software were all it took to crack through one company’s advanced security barriers. By reading this article it is hoped that employees at all levels of an organization’s hierarchy will become more aware of—and recognize—how: 1) bits and pieces of seemingly harmless and easy-to-acquire information can be used for sinister purposes;2) building rapport and trust with a person can make them more likely to become unknowing co-conspirators in a devious undertaking;and 3) how one must be constantly alert not to give out information without carefully considering the authenticity and justification of the source requesting it.
基金Supported by the U.S. Department of Energy(DOE),Office of Industrial Technology under contract DE-PS0703ID14425:Industrial Materials for the Future Program and through contracts with Spirex Corporation and Owens-Illinois
文摘Laser additive manufacturing(LAM) of tungsten carbide metal matrix composites(MMCs) has been evaluated for surface modification of hot die forming tools,cutting edges,glass tooling,extrusion mandrels,and other abrasive wear applications.This work focuses on transitions from tool steels to MMCs through a single pass laser powder deposition operation.Issues related to the application of various metal powders and carbides used include surface hardness,porosity,cracking,and dilution.These issues along with factory results that were obtained during this project are discussed.
文摘The ever-increasing dependence on electrical power has posed more challenges to power system engineers to deliver secure, stable, and sustained energy to electricity consumers. Due to the increasing occurrence of short-and long-term power interruptions in the power system, the need for a systematic approach to mitigate the negative impacts of such events is further manifested. Self-healing and its control strategies are generally accepted as a solution for this concern. Due to the importance of self-healing subject in power distribution systems, this paper conducts a comprehensive literature review on self-healing from existing published papers. The concept of self-healing is briefly described, and the published papers in this area are categorized based on key factors such as self-healing optimization goals, available control actions, and solution methods. Some proficient techniques adopted for self-healing improvements are also classified to have a better comparison and selection of methods for new investigators. Moreover, future research directions that need to be explored to improve self-healing operations in modern power distribution systems are investigated and described at the end of this paper.
基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20040401)Strategic Priority Research Program of the Chinese Academy of Sciences(XDA19040501)+2 种基金National Key Research and Development Program of China(2017YFB0503605)National Key Research and Development Program of China(2017YFC1503003)National Natural Science Foundation of China(41901395)。
文摘Mobile internet and wireless communication technologies have produced unprecedented location-aware data.Such big geospatial data can be used as a proxy measure of the‘digital footprints’left by us on the planet and provide a valuable opportunity to understand the dynamic and short-term human disturbance on the nature at fine scales.This study investigated the spatiotemporal variations of human’s digital footprints on the Qinghai-Tibet Plateau using smartphone-users-generated Tencent’s location request data.The results showed that human’s digital footprints cover less than 5%of Qinghai and Tibet,exhibiting either a U-shaped or an N-shaped temporal change pattern during the major festivals.Spatial changes of the digital footprints manifested a transition process from dispersion to concentration in Xining and Lhasa.Human disturbance assessment of seven large nature reserves on the plateau showed that the Qinghai Lake is the most disturbed one as shown by 14.6%of its area is stained with human digital footprints and the areal average of footprint intensity is 1.59,and the disturbance was significantly escalated during the National Day holiday.By contrast,the Qangtang and Hoh Xil are the least affected nature reserves with the two indices less than 1%and 0.1,respectively.
基金The State Key Laboratory of Resources and Environmental Information System,No.088RA500KA National Natural Science Foundation of China,No.41071250No.41371378
文摘This study presented a quantitative comparison of cockpit and doline karst by examining the numbers and characteristics of typical types of landform entities that are developed in Guilin(Guangxi, China), La Alianza(PR, USA), Avalton(KY, USA), and Oolitic(IN, USA). Five types of landform entities were defined: isolated hill(IH), clustered hills(CHs), isolated sinkhole(IS), clustered sinkholes(CSs), and clustered hills with sinkholes(CHSs). An algorithm was developed to automatically identify these types of landform entities by examining the contour lines on topographic maps of two cockpit karst areas(Guilin and La Alianza) and two doline karst areas(Oolitic and Avalton). Within each specific study area, the CHSs is the least developed type yet with a larger size and higher relief. The IH and IS entities are smaller in size, lower in relief, and outnumber their clustered counterparts. The total numbers of these types of entities are quite different in cockpit and doline karst areas. Doline karst is characterized by more negative(IS and CSs) than positive(IH and IHs) landforms and vice versa for cockpit karst. For example, the Guilin study area has 1192 positive landform entities in total, which occupy 9.81% of the total study area. It has only 622 negative landform entities occupying only 3.91% of the total study area. By contrast, the doline karst in Oolitic has 130 negative while only 10 positive landform entities. The positive and negative landforms in Oolitic occupy 12.68% and 2.61% of the total study area, respectively. Furthermore, average relief and slope of the landform entities are much higher and steeper in the cockpit karst than the doline karst areas. For instance, the average slope of CHs in Alvaton is 3.90 degrees while it is 19.78 degrees in La Alianza. The average relief of CSs is 4.07 m and 34.29 m in Oolitic and Guilin respectively. Such a difference within a specific area or between the cockpit and doline karst may reveal different controls on the development of karst landscape.
基金the National Key R&D Program of China(grant number 2017YFC1503003)the National Key Research and Development Program(grant number 2017YFB0503605)the National Mountain Flood Disaster Investigation Project(SHZH-IWHR-57).
文摘Location-aware big data from social media have been widely used to quantitatively characterize natural disasters and disaster-induced losses.It is not clear how human activities collectively respond to a disaster.In this study,we examined the collective human activities in response to Typhoon Hato at multi spatial scales using aggregated location request data.We proposed a Multilevel Abrupt Changes Detection(MACD)methodological framework to detect and characterize the abrupt changes in location requests in response to Typhoon Hato.Results show that,at the grid level,most anomaly grids were located within a radius of 53 km around the typhoon trajectory.At the city level,there are significant spatial difference in terms of the human activity recovery duration(230 h on average).At the subnational level,the absolute magnitude of abrupt location request changes is strongly correlated with the typhoon-induced economic losses and the population affected.
文摘Two stochastic models are derived for a susceptible-infectious-susceptible epidemic spreading through a metapopulation: a continuous time Markov chain (CTMC) model and an It6 stochastic differential equation (SDE) model. The stochastic models are numerically compared. Close agreement suggests that computationally intense CTMC simulations can be approximated by simpler SDE simulations. Differential equations for the moments of the SDE probability distribution are also derived, the steady states are solved numerically using a moment closure technique, and these results are compared to simulations. The moment closure technique only coarsely approximates simulation results. The effect of model parameters on stability of the disease-free equilibrium is also numerically investigated.