Modeling of Thermoelectric Generator Power Characteristics for Motorcycle-Type Engines

Science.gov (United States)

Osipkov, Alexey; Poshekhonov, Roman; Arutyunyan, Georgy; Basov, Andrey; Safonov, Roman

2017-10-01

Thermoelectric generation in vehicles such as motorcycles, all-terrain vehicles, and snowmobiles opens the possibility of additional electrical energy generation by means of exhaust heat utilization. This is beneficial because replacing the mechanical generator used in such vehicles with a more powerful one in cases of electrical power deficiency is impossible. This paper proposes a calculation model for the thermoelectric generator (TEG) operational characteristics of the low-capacity internal combustion engines used in these vehicles. Two TEG structures are considered: (1) TEG with air cooling and (2) TEG with water cooling. Modeling consists of two calculation stages. In the first stage, the heat exchange coefficients of the hot and cold exchangers are determined using computational fluid dynamics. In the second stage, the TEG operational characteristics are modeled based on the nonlinear equations of the heat transfer and power balance. On the basis of the modeling results, the dependence of the TEG's major operating characteristics (such as the electrical power generated by the TEG and its efficiency and mass) on operating conditions or design parameters is determined. For example, the electrical power generated by a TEG for a Yamaha WR450F motorcycle engine with a volume of 0.449 × 10-3 m3 was calculated to be as much as 100 W. Use of the TEG arrangements proposed is justified by the additional electrical power generation for small capacity vehicles, without the need for internal combustion engine redesign.

AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT XV, UNDERSTANDING DC GENERATOR PRINCIPLES (PART II).

Science.gov (United States)

Human Engineering Inst., Cleveland, OH.

THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF MAINTENANCE PROCEDURES FOR DIRECT CURRENT GENERATORS USED ON DIESEL POWERED EQUIPMENT. TOPICS ARE SPECIAL GENERATOR CIRCUITS, GENERATOR TESTING, AND GENERATOR POLARITY. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL PROGRAMED TRAINING FILM "DC GENERATORS II--GENERATOR…

Learner Characteristics and Understanding Nature of Science: Is There an Association?

Science.gov (United States)

Çetinkaya-Aydin, Gamze; Çakiroglu, Jale

2017-01-01

The purpose of this study was to investigate the possible associations between preservice science teachers' understanding of nature of science and their learner characteristics; understanding of nature of scientific inquiry, science teaching self-efficacy beliefs, metacognitive awareness level, and faith/worldview schemas. The sample of the…

Thermal-hydraulic characteristic of the PGV-1000 steam generator

International Nuclear Information System (INIS)

Ubra, O.; Doubek, M.

1995-01-01

Horizontal steam generators are typical parts of nuclear power plants with pressure water reactor type VVER. By means of this computer program, a detailed thermal-hydraulic study of the horizontal steam generator PGV-1000 has been carried out and a special attention has been paid to the thermal-hydraulics of the secondary side. A set of important steam generator characteristics has been obtained and analyzed. Some of the interesting results of the analysis are presented in the paper. (author)

Analysis of drought characteristics for improved understanding of a water resource system

Directory of Open Access Journals (Sweden)

A. T. Lennard

2014-09-01

Full Text Available Droughts are a reoccurring feature of the UK climate; recent drought events (2004–2006 and 2010–2012 have highlighted the UK’s continued vulnerability to this hazard. There is a need for further understanding of extreme events, particularly from a water resource perspective. A number of drought indices are available, which can help to improve our understanding of drought characteristics such as frequency, severity and duration. However, at present little of this is applied to water resource management in the water supply sector. Improved understanding of drought characteristics using indices can inform water resource management plans and enhance future drought resilience. This study applies the standardised precipitation index (SPI to a series of rainfall records (1962–2012 across the water supply region of a single utility provider. Key droughts within this period are analysed to develop an understanding of the meteorological characteristics that lead to, exist during and terminate drought events. The results of this analysis highlight how drought severity and duration can vary across a small-scale water supply region, indicating that the spatial coherence of drought events cannot be assumed.

Improvements of characteristics of open cycle Faraday type MHD power generator

International Nuclear Information System (INIS)

Yoshida, Masaharu; Umoto, Juro; Aoki, Sigeo

1982-01-01

MHD power generators are classified into two types: Faraday type and diagonal type (including Hall type). It is considered also in Faraday type generators that the characteristics can be improved further by selecting the aspect ratio appropriately, and employing cap electrodes which approach diagonal conducting side-wall type from parallel plate electrodes. First, the three-dimensional analysis using a new equivalent circuit is introduced, in which finite electrode division and working gas boundary layer are considered using the generalized Ohm's law, Maxwell's electromagnetic equations and others. The above described improvement of characteristics is investigated numerically fully applying this analyzing method. If the wall temperature is low, the increase in the aspect ratio of a generating duct cross-section considerably improves the characteristics because plasma non-uniformity decreases. If the cap electrodes having an optimum side-wall length are used, the output increases considerably because the load current is given and received through the side-wall electrodes. Efficiency is a little lower than the case using parallel plate electrodes. Therefore, if the aspect ratio is taken sufficiently large, and the cap electrodes with optimum side-wall electrode length are used, the generator characteristics are greatly improved since the above mentioned effects are multiplied. (Wakatsuki, Y.)

Next-Generation Sequencing: From Understanding Biology to Personalized Medicine

Directory of Open Access Journals (Sweden)

Benjamin Meder

2013-03-01

Full Text Available Within just a few years, the new methods for high-throughput next-generation sequencing have generated completely novel insights into the heritability and pathophysiology of human disease. In this review, we wish to highlight the benefits of the current state-of-the-art sequencing technologies for genetic and epigenetic research. We illustrate how these technologies help to constantly improve our understanding of genetic mechanisms in biological systems and summarize the progress made so far. This can be exemplified by the case of heritable heart muscle diseases, so-called cardiomyopathies. Here, next-generation sequencing is able to identify novel disease genes, and first clinical applications demonstrate the successful translation of this technology into personalized patient care.

Vibration and wear characteristics of steam generator tubes

International Nuclear Information System (INIS)

Choi, Young Hwan

2003-06-01

This study investigates the fluid elastic instability characteristics of Steam Generator (SG) U-tubes with defect and the safety assessment of the potential for fretting-wear damages on Steam Generator (SG) U-tubes caused by foreign object in operating nuclear power plants. The operating SG shell-side flow field conditions for determining the fluid elastic instability or fretting-wear parameters such as damping ratio, added mass and flow velocity are obtained from three-dimensional SG flow calculation using the ATHOS3 code. To get the natural frequency, corresponding mode shape and participation factor, modal analyses are performed for the U-tubes either with axial or circumferential flaw with different sizes. Special emphases are on the effects of flaw orientation and size on the modal and instability characteristics of tubes, which are expressed in terms of the natural frequency, corresponding mode shape and stability ratio. Also, the wear rate of U-tube caused by foreign object is calculated using the Archard formula and the remaining life of the tube is predicted, and discussed in this study is the effect of the flow velocity and vibration of the tube on the remaining life of the tube. In addition, addressed is the effect of the internal pressure on the vibration and fretting-wear characteristics of the tube

The understanding of art students toward characteristic of Negeri Sembilan Minangkabau Traditional House

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Taharuddin Nurul Shima

2016-01-01

Full Text Available In Negeri Sembilan, they are still practicing Minangkabau culture and custom. Element of uniqueness in Negeri. Sembilan has been shown on its architectural where the houses have dramatic curved roof structures with multitier. The art and architecture features a unique regional style. This house fills with cultural values, customs and reflects the people’s understanding about designing art and architecture that is in harmony with nature. The house serves as a residence, a hall for family meetings, and for ceremonial activities. This research, studies the understanding of art students towards the characteristic that are found in the Negeri Sembilan Minangkabau Traditional House (NSMTH in Negeri Sembilan, Malaysia. The objectives are to identify the element of characteristic that shows the identity of Negeri Sembilan Minangkabau Traditional House and to determine the level of understanding on characteristic of a Minangkabau house by art students. Scope of this research is on understanding of Faculty Art & Design student that has syllabus on Malay art. The research methodology that been use in this research is quantitative where surveys are made among the art students

Learning-Related Changes in Adolescents' Neural Networks during Hypothesis-Generating and Hypothesis-Understanding Training

Science.gov (United States)

Lee, Jun-Ki; Kwon, Yongju

2012-01-01

Fourteen science high school students participated in this study, which investigated neural-network plasticity associated with hypothesis-generating and hypothesis-understanding in learning. The students were divided into two groups and participated in either hypothesis-generating or hypothesis-understanding type learning programs, which were…

Understanding Consumer Interaction on Instagram: The Role of Satisfaction, Hedonism, and Content Characteristics.

Science.gov (United States)

Casaló, Luis V; Flavián, Carlos; Ibáñez-Sánchez, Sergio

2017-06-01

The increasing relevance of Instagram and its growing adoption among top brands suggest an effort to better understand consumers' behaviors within this context. The purpose of this study is to examine the role of perceived hedonism and satisfaction in determining consumers' intentions to interact and their actual interaction behaviors (the number of likes, by tapping a heart icon, and comments) in a brand's official Instagram account. Also, we investigate the effect of consumer perceptions about the characteristics of the content generated in the account (perceived originality, quantity, and quality) on their perceived hedonism and satisfaction. Data were collected in two stages from 808 members of a fashion brand's official Instagram account. First, participants answered an online questionnaire to evaluate their perceptions, satisfaction, and interaction intentions. Second, 1 month later, we measure the number of likes and comments done by each participant in the brand's official Instagram account during that month. Using partial least squares to analyze the data, perceived hedonism is found to affect both satisfaction and the intention to interact in Instagram, which in turn influences actual behavior. Besides, perceived originality is the most relevant content characteristic to develop perceived hedonism. These findings offer managers a general vision of consumers' behaviors on Instagram, highlighting the importance of hedonism to create a satisfactory experience.

Complementary power output characteristics of electromagnetic generators and triboelectric generators.

Science.gov (United States)

Fan, Feng-Ru; Tang, Wei; Yao, Yan; Luo, Jianjun; Zhang, Chi; Wang, Zhong Lin

2014-04-04

Recently, a triboelectric generator (TEG) has been invented to convert mechanical energy into electricity by a conjunction of triboelectrification and electrostatic induction. Compared to the traditional electromagnetic generator (EMG) that produces a high output current but low voltage, the TEG has different output characteristics of low output current but high output voltage. In this paper, we present a comparative study regarding the fundamentals of TEGs and EMGs. The power output performances of the EMG and the TEG have a special complementary relationship, with the EMG being a voltage source and the TEG a current source. Utilizing a power transformed and managed (PTM) system, the current output of a TEG can reach as high as ∼3 mA, which can be coupled with the output signal of an EMG to enhance the output power. We also demonstrate a design to integrate a TEG and an EMG into a single device for simultaneously harvesting mechanical energy. In addition, the integrated NGs can independently output a high voltage and a high current to meet special needs.

Characteristics Analysis of an Excitation Assistance Switched Reluctance Wind Power Generator

DEFF Research Database (Denmark)

Liu, Xiao; Wang, Chao; Chen, Zhe

2015-01-01

In order to fully analyze the characteristics of an excitation assistance switched reluctance generator (EASRG) applied in wind power generation, a static model and a dynamic model are proposed. The static model is based on the 3-D finite-element method (FEM), which can be used to obtain the stat...

Characteristics and Generation of Household Hazardous Waste (HHW in Semarang City Indonesia

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Fikri Elanda

2018-01-01

Full Text Available Most of Household Hazardous Waste (HHW is currently mixed with domestics waste. So that, it can impact human health and environmental quality. One important aspect in the management strategy is to determine the quantity generated and characteristics of HHW. The method used to determine the characteristics HHW refers to SNI 19-2454-2002, while the HHW generation refers to the SNI 19-3694-1994 calculated based on weight and volume. Research was conducted in four districts of Semarang. The samples used in this study were 400 families calculated based on the proportion of Slovin Formula. The characteristic of HHW in Semarang City is mainly infectious (79%, then poisonous (13%, combustible (6% and corrosive materials (2%. The quantity HHW generated is 0.01 kg/person/day equivalent with 5.1% of municipal solid waste (MSW in Semarang (linear equations : y=1,278x+82,00 (volume, y=0,216x+13,89 (weight.

Characteristics and Generation of Household Hazardous Waste (HHW) in Semarang City Indonesia

Science.gov (United States)

Fikri, Elanda; Purwanto; Sunoko, Henna Rya

2018-02-01

Most of Household Hazardous Waste (HHW) is currently mixed with domestics waste. So that, it can impact human health and environmental quality. One important aspect in the management strategy is to determine the quantity generated and characteristics of HHW. The method used to determine the characteristics HHW refers to SNI 19-2454-2002, while the HHW generation refers to the SNI 19-3694-1994 calculated based on weight and volume. Research was conducted in four districts of Semarang. The samples used in this study were 400 families calculated based on the proportion of Slovin Formula. The characteristic of HHW in Semarang City is mainly infectious (79%), then poisonous (13%), combustible (6%) and corrosive materials (2%). The quantity HHW generated is 0.01 kg/person/day equivalent with 5.1% of municipal solid waste (MSW) in Semarang (linear equations : y=1,278x+82,00 (volume), y=0,216x+13,89 (weight).

Endometrial carcinoma in the baby boomer generation. Tumor characteristics and clinical outcome.

Science.gov (United States)

Elshaikh, Mohamed A; Cattaneo, Richard; Shah, Mira; Patel, Suketu; Mahan, Meredith; Buekers, Thomas; Siddiqui, Farzan

2013-02-01

Baby boomers (BB) entering retirement represent a significant burden on medical resources. The unique lifestyle characteristics engendered by the BB may lead to different endometrial cancer characteristics that bear understanding. We sought to characterize BB with endometrioid carcinoma after hysterectomy and compare the results to those of prior to the baby boomers (PB). After reviewing our prospectively maintained database of 1,450 patients with endometrial cancer, we identified 595 patients who underwent hysterectomy for 1988 International Federation of Gynecologic Oncology (FIGO) stage I-II uterine endometrioid carcinomas, who were born between 1926 and 1964. Their medical records were reviewed in this Institutional review board (IRB)-approved study. Patients with non-endometrioid carcinoma and those who received preoperative therapy were excluded. Patients were defined as BB (born 1946-1964) or PB (born in 1926-1945). The two groups were compared regarding patients' demographics, tumor characteristics and survival. Following a univariate analysis, multivariable modeling was carried out using Cox regression analysis. All patients underwent hysterectomy with a minimum of two years' follow-up. There were 234 patients (39%) in the BB group and 361 patients (61%) in the PB group. Median follow-up for the study cohort was 56 months. BB had higher body mass index (p=0.027), lower tumor grade (p=0.002), earlier FIGO stage (p=0.023), higher number of dissected lymph nodes (p=0.008), less lymphvascular space involvement (p=generation.

Turbulence induced Fretting-wear characteristics of steam generator helical tubes

International Nuclear Information System (INIS)

Jhung, Myung Jo; Jo, Jong Chull; Kim, Hho Jung; Yune, Young Gill; Yu, Seon Oh

2005-01-01

This study addresses safety assessment of the potential for fretting-wear damages on steam generator helical tubes due to turbulence-induced vibration in operating nuclear power plants. To get the natural frequency, corresponding mode shape and participation factor, modal analyses are performed for helical type tubes with various conditions. Special emphases are put on the effects of coil diameter and the number of turns on the modal and fretting wear characteristics of tubes. Also, investigated are the effects of external pressure on the tube modal characteristics as well as the effects of turbulence induced vibration on the fretting-wear characteristics of tubes

Study on the construction and its operating characteristics of Marx high voltage pulse generator

International Nuclear Information System (INIS)

Chung, W.K.; Yook, C.C.

1984-01-01

This study is to investigate the operating characteristics of a Marx high voltage pulse generator, which is designed and fabricated for the purpose of constructing a linear theta-pinch plasma generating facility. The Marx generator consists of a 2 kJ capacitor bank of maximum output voltage of 200kV, a set of main spark switch, a triggring system, and high voltage charging power supply. The experimental results show that the operating characteristics of the generator can be controlled through varying nitrogen pressure as a filling gas. The output pulse of the generator is achieved close to the estimated voltage with the rise time of 3*m seconds. The stability of the generator is also very satisfactory within operating range of main spark switch. (Author)

The design of wind turbine for electrical power generation in Malaysian wind characteristics

International Nuclear Information System (INIS)

Abas Ab Wahab; Chong Wen Thong

2000-01-01

The paper describes the study of a wind turbine for electrical power generation in Malaysia wind characteristics. In this research, the wind turbine is designs based on the local wind characteristics and tries to avoid the problems faced in the past (turbine design, access, manpower and technical). The new wind turbine rotor design for a medium speed wind speed turbine utilises the concept of open-close type of horizontal axis (up-wind) wind turbine is intended to widen the optimum performance range for electrical generation in Malaysia wind characteristics. The wind turbine has been designed to cut-in at a lower speed, and to provide the rotation speed that high enough to run a generator. The analysis and design of new low speed wind turbine blades and open-close turbine rotor and prediction of turbine performance are being detailed in this paper. (Author)

Resources for future generations – understanding earth and people

OpenAIRE

Thompson, J.; Eagle, L.; Bonham, O.

2017-01-01

Earth’s growing population requires resources for the basics of life and increasing standards of living. Energy from many sources, numerous minerals and water are critical for human existence, and are increasingly linked in the context of sustainability. For future generations, resources must be discovered and cleanly exploited, even as efforts to improve efficiency and increase recycling continue. To succeed, we must fully understand the earth, from the critical processes that concentrate r...

Electricity Generation Characteristics of Energy-Harvesting System with Piezoelectric Element Using Mechanical-Acoustic Coupling

Directory of Open Access Journals (Sweden)

Hirotarou Tsuchiya

2016-01-01

Full Text Available This paper describes the electricity generation characteristics of a new energy-harvesting system with piezoelectric elements. The proposed system is composed of a rigid cylinder and thin plates at both ends. The piezoelectric elements are installed at the centers of both plates, and one side of each plate is subjected to a harmonic point force. In this system, vibration energy is converted into electrical energy via electromechanical coupling between the plate vibration and piezoelectric effect. In addition, the plate vibration excited by the point force induces a self-sustained vibration at the other plate via mechanical-acoustic coupling between the plate vibrations and an internal sound field into the cylindrical enclosure. Therefore, the electricity generation characteristics should be considered as an electromechanical-acoustic coupling problem. The characteristics are estimated theoretically and experimentally from the electric power in the electricity generation, the mechanical power supplied to the plate, and the electricity generation efficiency that is derived from the ratio of both power. In particular, the electricity generation efficiency is one of the most appropriate factors to evaluate a performance of electricity generation systems. Thus, the effect of mechanical-acoustic coupling is principally evaluated by examining the electricity generation efficiency.

Principal characteristics of SFC type MHD generator

International Nuclear Information System (INIS)

Kayukawa, Naoyuki; Oikawa, Shun-ichi; Aoki, Yoshiaki; Seidou, Tadashi; Okinaka, Noriyuki

1988-01-01

This paper describes the experimental and analytical results obtained for an MHD channel with a two dimensionally shaped magnetic field configuration called 'the SFC-type'. The power generating performance was examined under various load conditions and B-field intensities with a 2 MWt shock tunnel MHD facility. It is demonstrated that the power output performance and the enthalpy extraction scaling law of the conventional uniform B-field MHD generator (UFC-type) were significantly improved by the SFC-design of the spatial distribution of the magnetic field. The arcing processes were also examined by a high speed camera and the post-test observation of arc spot traces on electrodes. Further, the characteristic frequencies of each of the so-called micro and constricted arcs were clarified by spectral analyses. The critical current densities, which define the transient conditions of each from the diffuse-to micro arc, and from the micro-to constricted arc modes could be clearly obtained by the present spectral analysis method. We also investigated the three-dimensional behavior under strong magnetic field based on the coupled electrical and hydrodynamical equations for both of the middle scale SFC-and UFC-type generators. Finally, it is concluded from the above mentioned various aspects that the shaped 2-D magnetic field design will offer a most useful means for the realization of a compact, high efficiency and a long duration open-cycle MHD generator. (author)

Fretting-wear characteristics of steam generator tubes contacting with foreign object

International Nuclear Information System (INIS)

Jo, Jong Chull; Jhung, Myung Jo; Kim, Woong Sik; Kim, Hho Jung

2003-01-01

Fretting-wear characteristics of steam generator tubes contacting with foreign object has been investigated in this study. The operating steam generator shell-side flow field conditions are obtained from three-dimensional steam generator flow calculation using a well-validated steam generator thermal-hydraulic analysis computer code. Modal analyses are performed for the finite element modelings of tubes to get the natural frequency, corresponding mode shape and participation factor. The wear rate of a steam generator tube caused by foreign object is calculated using the Archard formula and the remaining life of the tube is predicted. In addition, the effects of internal pressure and flow velocity on the remaining life of the tube are discussed in this paper

The generation characteristics of solid radioactive wastes in the KEPCO nuclear power plants

International Nuclear Information System (INIS)

Shon, Soon Hwan; Kang, Duck Won; Kim, Hee Keun

1991-01-01

Solid radwastes generation trend and characteristics were discussed for nuclear power plants in KEPCO. Each plant has a specific tendency of solid radwastes generation due to the plant characteristics. The total volume of solid radwastes generated from nine power plants was accumulated in 23,012 drums by the end of 1989. The average annual volume per unit was about 670 drums. The solid radwaste mostly consisted of solidified concentrates and contaminated trash. The contaminated trash has been the major portion of the solid radwastes since 1982. The volume of the contaminated trash was dependent on the availability factor and period of overhaul. Therefore, the contaminated trash was considered to be a prime target for the solid radwastes minimization plan

Experimental Research on the Characteristic of a Generator Used in Wave Energy Conversion

Science.gov (United States)

Lu, Zhongyue; Shang, Jianzhong; Luo, Zirong; Sun, Chongfei; Wu, Guoheng

2018-01-01

Due to the environmental issues like global warming and pollution, the exploration for ocean energy becomes important. Selecting the suitable generator for wave energy generation system is essential to improve the efficiency of power generation system. Thus, the object of the research is the generator of a self-adaptation inversion type wave energy absorption device. The major focus of this paper is the characteristics and the technique of the generator used in prototype. By setting up the generator performance test platform, the output voltage, efficiency and performance of the generator are tested to select the suitable generator for the wave energy generating system.

Learner Characteristics and Understanding Nature of Science. Is There an Association?

Science.gov (United States)

Çetinkaya-Aydın, Gamze; Çakıroğlu, Jale

2017-11-01

The purpose of this study was to investigate the possible associations between preservice science teachers' understanding of nature of science and their learner characteristics; understanding of nature of scientific inquiry, science teaching self-efficacy beliefs, metacognitive awareness level, and faith/worldview schemas. The sample of the current study was 60 3rd-year preservice science teachers enrolled in the Nature of Science and History of Science course. Using a descriptive and associational case study design, data were collected by means of different qualitative and quantitative questionnaires. Analysis of the data revealed that preservice science teachers' understanding of nature of science and nature of scientific inquiry were highly associated. Similarly, science teaching self-efficacy beliefs, metacognitive awareness levels, and faith/worldviews of the preservice science teachers were found to be significantly associated with their understanding of nature of science. Thus, it can be concluded that there might be other factors interfering with the learning processes of nature of science.

[Relationships amongst work values, job characteristics and job involvement in "net generation" nurses].

Science.gov (United States)

Chen, Sue-Hui; Chiou, Chii-Jun

2010-04-01

Children of the so-called "net generation" began joining the nurse workforce from the mid-1990s. Studies on the characteristics of this generation have been done primarily outside of Taiwan, and results may not adequately reflect conditions in Taiwan due to cultural differences. This study aimed to investigate the relationships amongst work values, job characteristics and job involvement in "net generation" nurses. This study employed a cross-sectional design. A randomized sample of 370 nurses born between 1977 and 1985 working in a medical center or a community hospital in Southern Taiwan accepted our invitation to join this study. A structured questionnaire was used to collect data. (1) Variables including work values, job characteristics, head nurse leadership qualities, job structure and opportunities for in-service education all correlated significantly with job involvement. (2) Regression analysis showed work values, job characteristics, head nurse leadership and religious belief to be significant predictors of job involvement, explaining 22.6% of the variance. This study provides insights that may be of potential value to nursing administrators. We suggest that administrators adopt democratic management practices, build diverse learning methods, strengthen autonomy, completeness, and feedback, and provide appropriate work guidance for nurses to increase job involvement.

CFD evaluation on the thermohydraulic characteristics of tube support plates in steam generator

Energy Technology Data Exchange (ETDEWEB)

Zhang, B.; Zhang, H.; Han, B.; Yang, B.W. [Xi' an Jiaotong Univ. (China). School of Nuclear Science and Technology; Mo, S.J.; Ren, H.B.; Qin, J.M.; Zuo, C.P. [China Nuclear Power Design Co. Ltd., ShenZhen (China)

2016-07-15

The integrity and thermal hydraulic characteristics of steam generator are of great concern in the nuclear industry. The tube support plates (TSP), one of the most important components of the steam generator, not only support the heat transfer tubes, but also affect the flow dynamic and thermal hydraulic characteristics of the secondary-side flow inside the steam generator. Different working conditions, ranging from single-phase adiabatic condition to two-phase high-void boiling condition, are simulated and analyzed. Calculated void fraction, under simple geometry, agrees well with the experiment data whilst the simulated heat transfer coefficient is tremendously close to the empirical correlation. Temperature, void fraction, and velocity distributions in different locations show reasonable distribution. The simulation results indicate that TSP can enhance the heat transfer in the secondary side of the steam generator. On the top of TSP, with the increase in cross-section flow area, the back-flow phenomenon occurs, which might lead to the contamination of precipitation.

Do doctors understand the test characteristics of lung cancer screening?

Science.gov (United States)

Schmidt, Richard; Breyer, Marie; Breyer-Kohansal, Robab; Urban, Matthias; Funk, Georg-Christian

2018-04-01

Screening for lung cancer with a low-dose computed tomography (CT) scan is estimated to prevent 3 deaths per 1000 individuals at high risk; however, false positive results and radiation exposure are relevant harms and deserve careful consideration. Screening candidates can only make an autonomous decision if doctors correctly inform them of the pros and cons of the method; therefore, this study aimed to evaluate whether doctors understand the test characteristics of lung cancer screening. In a randomized trial 556 doctors (members of the Austrian Respiratory Society) were invited to answer questions regarding lung cancer screening based on online case vignettes. Half of the participants were randomized to the group 'solutions provided' and received the correct solutions in advance. The group 'solutions withheld' had to rely on prior knowledge or estimates. The primary endpoint was the between-group difference in the estimated number of deaths preventable by screening. Secondary endpoints were the between-group differences in the prevalence of lung cancer, prevalence of a positive screening results, sensitivity, specificity, positive predictive value, and false negative rate. Estimations were also compared with current data from the literature. The response rate was 29% in both groups. The reduction in the number of deaths due to screening was overestimated six-fold (95% confidence interval CI: 4-8) compared with the actual data, and there was no effect of group allocation. Providing the correct solutions to doctors had no systematic effect on their answers. Doctors poorly understand the test characteristics of lung cancer screening. Providing the correct solutions in advance did not improve the answers. Continuing education regarding lung cancer screening and the interpretation of test characteristics may be a simple remedy. Clinical trial registered with www.clinicaltrials.gov (NCT02542332).

Are Generation Y Nurses Satisfied on the Job? Understanding Their Lived Experiences.

Science.gov (United States)

Anselmo-Witzel, Sonia; Orshan, Susan A; Heitner, Keri L; Bachand, Jeanie

2017-04-01

The purpose of this study was to explore the lived experiences of job satisfaction among Generation Y nurses in the workplace. Job satisfaction in nursing is at an all-time low. With an increasing shortage of nurses, there is a need for more awareness and understanding of job satisfaction and intent to stay among Generation Y nurses who are the future generation of nurses. Descriptive phenomenology-guided, in-depth semistructured interviews were conducted to explore the lived experiences of job satisfaction among 10 Generation Y nurses. Four main themes and 6 subthemes that emerged brought meaning to the nurses' experiences. The 4 main themes were experiences of feeling good, relationships, job strain, and having choices. Findings indicated Generation Y nurses want to fulfill inner feelings of job satisfaction. If these inner feelings are not met, they will seek other opportunities to fulfill job satisfaction.

A Study of Distributed Generation System Characteristics and Protective Load Control Strategy

DEFF Research Database (Denmark)

Wei, Mu; Chen, Zhe

2011-01-01

Due to the smaller inertia feature of a Wind Turbine (WT) involved Distributed Generation System (DGS), the WT’s induction generator are more vulnerable to frequency and voltage disturbances. Therefore the study investigates the DGS characteristics respectively from power plants, i.e. WTs and load....... Two kinds of wind turbines: Doubly-fed Induction Generator (DFIG) and Fixed-speed Wind Turbine (FSWT) are compared in this study. A conventional power system protective scheme may not response promptly, which could lead an undesired disconnection of WTs for the turbine protection purpose. Consequently...

Spectral and spatial characteristics of third-harmonic generation in conical light beams

International Nuclear Information System (INIS)

Peet, V.E.; Shchemeljov, S.V.

2003-01-01

Generation of resonance-enhanced third harmonic in Bessel and other conical beams is analyzed from a simple picture, where the fundamental light field is decomposed into elementary configurations of crossed plain-wave sub-beams. We show that the overall harmonic output can be derived as a superposition of all partial harmonic components driven by elementary configurations of the fundamental field. Good agreement with experimental observations has been obtained in simulation of spectral and spatial characteristics of the generated third harmonic. Some peculiarities of harmonic generation in conical light fields are discussed

Dynamic characteristics of steam generator U-tubes with defect

International Nuclear Information System (INIS)

Jo, Jong Chull; Jhung, Myung Jo; Kim, Woong Sik; Kim, Hho Jung

2005-01-01

This study investigates the fluid elastic instability characteristics of steam generator (SG) U-tubes with defect and the safety assessment of the potential for fretting-wear damages caused by foreign object in operating nuclear power plants. To get the natural frequency, corresponding mode shape and participation factor, modal analyses are performed for the U-tubes either with axial or circumferential flaw with different sizes. Special emphases are on the effects of flaw orientation and size on the modal and instability characteristics of tubes, which are expressed in terms of the natural frequency, corresponding mode shape and stability ratio. Also, the wear rate of U-tube caused by foreign object is calculated using the Archard formula and the remaining life of the tube is predicted, and discussed in this study is the effect of the flow velocity and vibration of the tube on the remaining life of the tube. In addition, addressed in this study is the effect of the internal pressure on the vibration and fretting-wear characteristics of the tube

Thermal characteristics of combined thermoelectric generator and refrigeration cycle

International Nuclear Information System (INIS)

Yilbas, Bekir S.; Sahin, Ahmet Z.

2014-01-01

Highlights: • TEM location in between the evaporator and condenser results in low coefficient of performance. • TEM location in between condenser and its ambient improves coefficient of performance of the combined system. • High temperature ratio enhances coefficient of performance of combined system. • Certain values of parameters enhance combined system performance. - Abstract: A combined thermal system consisting of a thermoelectric generator and a refrigerator is considered and the effect of location of the thermoelectric generator, in the refrigeration cycle, on the performance characteristics of the combined system is investigated. The operating conditions and their influence on coefficient of performance of the combined system are examined through introducing the dimensionless parameters, such as λ(λ = Q HTE /Q H , where Q HTE is heat transfer to the thermoelectric generator from the condenser, Q H is the total heat transfer from the condenser to its ambient), temperature ratio (θ L = T L /T H , where T L is the evaporator temperature and T H is the condenser temperature), r C (r C = C L /C H , where C L is the thermal capacitance due to heat transfer to evaporator and C H , is the thermal capacitance due to heat rejected from the condenser), θ W (θ W = T W /T H , where T W is the ambient temperature), θ C (θ C = T C /T H , where T C is the cold space temperature). It is found that the location of the thermoelectric generator in between the condenser and the evaporator decreases coefficient of performance of the combined system. Alternatively, the location of thermoelectric device in between the condenser and its ambient enhances coefficient of performance of the combined system. The operating parameters has significant effect on the performance characteristics of the combined system; in which case temperature ratio (θ L ) within the range of 0.68–0.70, r C = 2.5, θ W = 0.85, and θ C = 0.8 improve coefficient of performance of the

Identification of influencing municipal characteristics regarding household waste generation and their forecasting ability in Biscay

Energy Technology Data Exchange (ETDEWEB)

Oribe-Garcia, Iraia, E-mail: iraia.oribe@deusto.es; Kamara-Esteban, Oihane; Martin, Cristina; Macarulla-Arenaza, Ana M.; Alonso-Vicario, Ainhoa

2015-05-15

Highlights: • We have modelled household waste generation in Biscay municipalities. • We have identified relevant characteristics regarding household waste generation. • Factor models are used in order to identify the best subset of explicative variables. • Biscay’s municipalities are grouped by means of hierarchical clustering. - Abstract: The planning of waste management strategies needs tools to support decisions at all stages of the process. Accurate quantification of the waste to be generated is essential for both the daily management (short-term) and proper design of facilities (long-term). Designing without rigorous knowledge may have serious economic and environmental consequences. The present works aims at identifying relevant socio-economic features of municipalities regarding Household Waste (HW) generation by means of factor models. Factor models face two main drawbacks, data collection and identifying relevant explanatory variables within a heterogeneous group. Grouping similar characteristics observations within a group may favour the deduction of more robust models. The methodology followed has been tested with Biscay Province because it stands out for having very different municipalities ranging from very rural to urban ones. Two main models are developed, one for the overall province and a second one after clustering the municipalities. The results prove that relating municipalities with specific characteristics, improves the results in a very heterogeneous situation. The methodology has identified urban morphology, tourism activity, level of education and economic situation as the most influencing characteristics in HW generation.

Identification of influencing municipal characteristics regarding household waste generation and their forecasting ability in Biscay

International Nuclear Information System (INIS)

Oribe-Garcia, Iraia; Kamara-Esteban, Oihane; Martin, Cristina; Macarulla-Arenaza, Ana M.; Alonso-Vicario, Ainhoa

2015-01-01

Highlights: • We have modelled household waste generation in Biscay municipalities. • We have identified relevant characteristics regarding household waste generation. • Factor models are used in order to identify the best subset of explicative variables. • Biscay’s municipalities are grouped by means of hierarchical clustering. - Abstract: The planning of waste management strategies needs tools to support decisions at all stages of the process. Accurate quantification of the waste to be generated is essential for both the daily management (short-term) and proper design of facilities (long-term). Designing without rigorous knowledge may have serious economic and environmental consequences. The present works aims at identifying relevant socio-economic features of municipalities regarding Household Waste (HW) generation by means of factor models. Factor models face two main drawbacks, data collection and identifying relevant explanatory variables within a heterogeneous group. Grouping similar characteristics observations within a group may favour the deduction of more robust models. The methodology followed has been tested with Biscay Province because it stands out for having very different municipalities ranging from very rural to urban ones. Two main models are developed, one for the overall province and a second one after clustering the municipalities. The results prove that relating municipalities with specific characteristics, improves the results in a very heterogeneous situation. The methodology has identified urban morphology, tourism activity, level of education and economic situation as the most influencing characteristics in HW generation

Fast random-number generation using a diode laser's frequency noise characteristic

Science.gov (United States)

Takamori, Hiroki; Doi, Kohei; Maehara, Shinya; Kawakami, Kohei; Sato, Takashi; Ohkawa, Masashi; Ohdaira, Yasuo

2012-02-01

Random numbers can be classified as either pseudo- or physical-random, in character. Pseudo-random numbers are generated by definite periodicity, so, their usefulness in cryptographic applications is somewhat limited. On the other hand, naturally-generated physical-random numbers have no calculable periodicity, thereby making them ideal for the task. Diode lasers' considerable wideband noise gives them tremendous capacity for generating physical-random numbers, at a high rate of speed. We measured a diode laser's output with a fast photo detector, and evaluated the binary-numbers from the diode laser's frequency noise characteristics. We then identified and evaluated the binary-number-line's statistical properties. We also investigate the possibility that much faster physical-random number parallel-generation is possible, using separate outputs of different optical-path length and character, which we refer to as "coherence collapse".

V-I characteristics of a coreless ironless electric generator in a closed-circuit mode for low wind density power generation

Science.gov (United States)

Razali, Akhtar; Rahman, Fadhlur; Leong, Yap Wee; Razali Hanipah, Mohd; Azri Hizami, Mohd

2018-04-01

This research deals with removal of ironcore lamination in electric generator to eliminate cog torque. A confinement technique is proposed to confine and focus magnetic flux by introducing opposing permanent magnets arrangement. The generator was fabricated and experimentally validated to qualify its loaded characteristics. The rotational torque and power output are measured and efficiency is then analyzed. At 100Ω load, the generator power output increased with the increased of rotational speed. Nearly 78% of efficiency was achieved when the generator was rotated at 250rpm. At this speed, the generator produced RMS voltage of 81VAC. Torque required to rotate the generator was found to be 3.2Nm. The slight increment of mechanical torque to spin the generator was due to the counter electromotive force (CEMF) existed in the copper windings. However, the torque required is still lower by nearly 30% than conventional AFPM generator. It is there concluded that this generator is suitable to be used for low wind density power generation application.

Characteristics of products generated by selective sintering and stereolithography rapid prototyping processes

Science.gov (United States)

Cariapa, Vikram

1993-01-01

The trend in the modern global economy towards free market policies has motivated companies to use rapid prototyping technologies to not only reduce product development cycle time but also to maintain their competitive edge. A rapid prototyping technology is one which combines computer aided design with computer controlled tracking of focussed high energy source (eg. lasers, heat) on modern ceramic powders, metallic powders, plastics or photosensitive liquid resins in order to produce prototypes or models. At present, except for the process of shape melting, most rapid prototyping processes generate products that are only dimensionally similar to those of the desired end product. There is an urgent need, therefore, to enhance the understanding of the characteristics of these processes in order to realize their potential for production. Currently, the commercial market is dominated by four rapid prototyping processes, namely selective laser sintering, stereolithography, fused deposition modelling and laminated object manufacturing. This phase of the research has focussed on the selective laser sintering and stereolithography rapid prototyping processes. A theoretical model for these processes is under development. Different rapid prototyping sites supplied test specimens (based on ASTM 638-84, Type I) that have been measured and tested to provide a data base on surface finish, dimensional variation and ultimate tensile strength. Further plans call for developing and verifying the theoretical models by carefully designed experiments. This will be a joint effort between NASA and other prototyping centers to generate a larger database, thus encouraging more widespread usage by product designers.

Next Generation Anodes for Lithium-Ion Batteries: Thermodynamic Understanding and Abuse Performance

Energy Technology Data Exchange (ETDEWEB)

Fenton, Kyle R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Allcorn, Eric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nagasubramanian, Ganesan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-12-01

The objectives of this report are as follows: elucidate degradation mechanisms, decomposition products, and abuse response for next generation silicon based anodes; and Understand the contribution of various materials properties and cell build parameters towards thermal runaway enthalpies. Quantify the contributions from particle size, composition, state of charge (SOC), electrolyte to active materials ratio, etc.

Communication systems, transceivers, and methods for generating data based on channel characteristics

Science.gov (United States)

Forman, Michael A; Young, Derek

2012-09-18

Examples of methods for generating data based on a communications channel are described. In one such example, a processing unit may generate a first vector representation based in part on at least two characteristics of a communications channel. A constellation having at least two dimensions may be addressed with the first vector representation to identify a first symbol associated with the first vector representation. The constellation represents a plurality of regions, each region associated with a respective symbol. The symbol may be used to generate data, which may stored in an electronic storage medium and used as a cryptographic key or a spreading code or hopping sequence in a modulation technique.

Next Generation Anodes for Lithium Ion Batteries: Thermodynamic Understanding and Abuse Performance.

Energy Technology Data Exchange (ETDEWEB)

Fenton, Kyle R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Allcorn, Eric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nagasubramanian, Ganesan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-09-01

The objectives of this project are to elucidate degradation mechanisms, decomposition products, and abuse response for next generation silicon based anodes; and understand the contribution of various materials properties and cell build parameters towards thermal runaway enthalpies. Quantify the contributions from various cell parameters such as particle size, composition, state of charge (SOC), electrolyte to active materials ratio, etc.

Open circuit V-I characteristics of a coreless ironless electric generator for low density wind power generation

Science.gov (United States)

Razali, Akhtar; Rahman, Fadhlur; Azlan, Syaiful; Razali Hanipah, Mohd; Azri Hizami, Mohd

2018-04-01

Cogging is an attraction of magnetism between permanent magnets and soft ironcore lamination in a conventional electric ironcore generator. The presence of cog in the generator is seen somehow restricted the application of the generator in an application where low rotational torque is required. Cog torque requires an additional input power to overcome, hence became one of the power loss sources. With the increasing of power output, the cogging is also proportionally increased. This leads to the increasing of the supplied power of the driver motor to overcome the cog. Therefore, this research is embarked to study fundamentally about the possibility of removing ironcore lamination in an electric generator. This research deals with removal of ironcore lamination in electric generator to eliminate cog torque. A confinement technique is proposed to confine and focus magnetic flux by introducing opposing permanent magnets arrangement. The concept is then fabricated and experimentally validated to qualify its no-load characteristics. The rotational torque and power output are measured and efficiency is then analyzed. Results indicated that the generator produced RMS voltage of 416VAC at rotational speed of 1762 RPM. Torque required to rotate the generator was at 2Nm for various rotational speed. The generator has shown 30% lesser rotational torque compared to the conventional ironcore type generator due to the absent of cogging torque in the system. Lesser rotational torque required to rotate has made this type of generator has a potential to be used for low wind density wind turbine application.

Compliance uncertainty of diameter characteristic in the next-generation geometrical product specifications and verification

International Nuclear Information System (INIS)

Lu, W L; Jiang, X; Liu, X J; Xu, Z G

2008-01-01

Compliance uncertainty is one of the most important elements in the next-generation geometrical product specifications and verification (GPS). It consists of specification uncertainty, method uncertainty and implementation uncertainty, which are three of the four fundamental uncertainties in the next-generation GPS. This paper analyzes the key factors that influence compliance uncertainty and then proposes a procedure to manage the compliance uncertainty. A general model on evaluation of compliance uncertainty has been devised and a specific formula for diameter characteristic has been derived based on this general model. The case study was conducted and it revealed that the completeness of currently dominant diameter characteristic specification needs to be improved

Advanced technologies on steam generators

Energy Technology Data Exchange (ETDEWEB)

Sakata, Kaoru; Nakamura, Yuuki [Mitsubishi Heavy Industry Co., Takasago (Japan); Nakamori, Nobuo; Mizutani, Toshiyuki; Uwagawa, Seiichi; Saito, Itaru [Mitsubishi Heavy Industry Co., Kobe (Japan); Matsuoka, Tsuyoshi [Mitsubishi Heavy Industry Co., Yokohama (Japan)

1997-12-31

The thermal-hydraulic tests for a horizontal steam generator of a next-generation PWR (New PWR-21) were performed. The purpose of these tests is to understand the thermal-hydraulic behavior in the secondary side of horizontal steam generator during the plant normal operation. A test was carried out with cross section slice model simulated the straight tube region. In this paper, the results of the test is reported, and the effect of the horizontal steam generator internals on the thermalhydraulic behavior of the secondary side and the circulation characteristics of the secondary side are discussed. (orig.). 3 refs.

Advanced technologies on steam generators

Energy Technology Data Exchange (ETDEWEB)

Sakata, Kaoru; Nakamura, Yuuki [Mitsubishi Heavy Industry Co., Takasago (Japan); Nakamori, Nobuo; Mizutani, Toshiyuki; Uwagawa, Seiichi; Saito, Itaru [Mitsubishi Heavy Industry Co., Kobe (Japan); Matsuoka, Tsuyoshi [Mitsubishi Heavy Industry Co., Yokohama (Japan)

1998-12-31

The thermal-hydraulic tests for a horizontal steam generator of a next-generation PWR (New PWR-21) were performed. The purpose of these tests is to understand the thermal-hydraulic behavior in the secondary side of horizontal steam generator during the plant normal operation. A test was carried out with cross section slice model simulated the straight tube region. In this paper, the results of the test is reported, and the effect of the horizontal steam generator internals on the thermalhydraulic behavior of the secondary side and the circulation characteristics of the secondary side are discussed. (orig.). 3 refs.

Comparison of class and continuous pedotransfer functions to generate soil hydraulic characteristics

NARCIS (Netherlands)

Wösten, J.H.M.; Finke, P.A.; Jansen, M.J.W.

1995-01-01

Class pedotransfer functions (PTF) and continuous PTFs were used to generate soil hydraulic characteristics. Both approaches were used to predict the soil physical input data to calculate five functional aspects of soil behaviour: number of workable days, number of days with adequate soil aeration,

Characteristics of bipolar-pulse generator for intense pulsed heavy ion beam acceleration

International Nuclear Information System (INIS)

Igawa, K.; Tomita, T.; Kitamura, I.; Ito, H.; Masugata, K.

2006-01-01

Intense pulsed heavy ion beams are expected to be applied to the implantation technology for semiconductor materials. In the application it is very important to purify the ion beam. In order to improve the purity of an intense pulsed ion beams we have proposed a new type of pulsed ion beam accelerator named 'bipolar pulse accelerator (BPA)'. A prototype of the experimental system has been developed to perform proof of principle experiments of the accelerator. A bipolar pulse generator has been designed for the generation of the pulsed ion beam with the high purity via the bipolar pulse acceleration and the electrical characteristics of the generator were evaluated. The production of the bipolar pulse has been confirmed experimentally. (author)

Physicochemical characteristics of aerosol particles generated during the milling of beryllium silicate ores: implications for risk assessment.

Science.gov (United States)

Stefaniak, Aleksandr B; Chipera, Steve J; Day, Gregory A; Sabey, Phil; Dickerson, Robert M; Sbarra, Deborah C; Duling, Mathew G; Lawrence, Robert B; Stanton, Marcia L; Scripsick, Ronald C

2008-01-01

Inhalation of beryllium dusts generated during milling of ores and cutting of beryl-containing gemstones is associated with development of beryllium sensitization and low prevalence of chronic beryllium disease (CBD). Inhalation of beryllium aerosols generated during primary beryllium production and machining of the metal, alloys, and ceramics are associated with sensitization and high rates of CBD, despite similar airborne beryllium mass concentrations among these industries. Understanding the physicochemical properties of exposure aerosols may help to understand the differential immunopathologic mechanisms of sensitization and CBD and lead to more biologically relevant exposure standards. Properties of aerosols generated during the industrial milling of bertrandite and beryl ores were evaluated. Airborne beryllium mass concentrations among work areas ranged from 0.001 microg/m(3) (beryl ore grinding) to 2.1 microg/m(3) (beryl ore crushing). Respirable mass fractions of airborne beryllium-containing particles were 80% in high-energy input areas (beryl melting, beryl grinding). Particle specific surface area decreased with processing from feedstock ores to drumming final product beryllium hydroxide. Among work areas, beryllium was identified in three crystalline forms: beryl, poorly crystalline beryllium oxide, and beryllium hydroxide. In comparison to aerosols generated by high-CBD risk primary production processes, aerosol particles encountered during milling had similar mass concentrations, generally lower number concentrations and surface area, and contained no identifiable highly crystalline beryllium oxide. One possible explanation for the apparent low prevalence of CBD among workers exposed to beryllium mineral dusts may be that characteristics of the exposure material do not contribute to the development of lung burdens sufficient for progression from sensitization to CBD. In comparison to high-CBD risk exposures where the chemical nature of aerosol

Experimental simulation: using generative modelling and palaeoecological data to understand human-environment interactions

Directory of Open Access Journals (Sweden)

George Perry

2016-10-01

Full Text Available The amount of palaeoecological information available continues to grow rapidly, providing improved descriptions of the dynamics of past ecosystems and enabling them to be seen from new perspectives. At the same time, there has been concern over whether palaeoecological enquiry needs to move beyond descriptive inference to a more hypothesis-focussed or experimental approach; however, the extent to which conventional hypothesis-driven scientific frameworks can be applied to historical contexts (i.e., the past is the subject of ongoing debate. In other disciplines concerned with human-environment interactions, including physical geography and archaeology, there has been growing use of generative simulation models, typified by agent-based approaches. Generative modelling encourages counter-factual questioning (what if…?, a mode of argument that is particularly important in systems and time-periods, such as the Holocene and now the Anthropocene, where the effects of humans and other biophysical processes are deeply intertwined. However, palaeoecologically focused simulation of the dynamics of the ecosystems of the past either seems to be conducted to assess the applicability of some model to the future or treats humans simplistically as external forcing factors. In this review we consider how generative simulation-modelling approaches could contribute to our understanding of past human-environment interactions. We consider two key issues: the need for null models for understanding past dynamics and the need to be able learn more from pattern-based analysis. In this light, we argue that there is considerable scope for palaeocology to benefit from developments in generative models and their evaluation. We discuss the view that simulation is a form of experiment and, by using case studies, consider how the many patterns available to palaeoecologists can support model evaluation in a way that moves beyond simplistic pattern-matching and how such models

Next Generation Anodes for Lithium Ion Batteries: Thermodynamic Understanding and Abuse Performance.

Energy Technology Data Exchange (ETDEWEB)

Fenton, Kyle R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Allcorn, Eric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nagasubramanian, Ganesan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2018-01-01

As we develop new materials to increase performance of lithium ion batteries for electric vehicles, the impact of potential safety and reliability issues become increasingly important. In addition to electrochemical performance increases (capacity, energy, cycle life, etc.), there are a variety of materials advancements that can be made to improve lithium-ion battery safety. Issues including energetic thermal runaway, electrolyte decomposition and flammability, anode SEI stability, and cell-level abuse tolerance behavior. Introduction of a next generation materials, such as silicon based anode, requires a full understanding of the abuse response and degradation mechanisms for these anodes. This work aims to understand the breakdown of these materials during abuse conditions in order to develop an inherently safe power source for our next generation electric vehicles. The effect of materials level changes (electrolytes, additives, silicon particle size, silicon loading, etc.) to cell level abuse response and runaway reactions will be determined using several techniques. Experimentation will start with base material evaluations in coin cells and overall runaway energy will be evaluated using techniques such as differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and accelerating rate calorimetry (ARC). The goal is to understand the effect of materials parameters on the runaway reactions, which can then be correlated to the response seen on larger cells (18650). Experiments conducted showed that there was significant response from these electrodes. Efforts to minimize risk during testing were taken by development of a smaller capacity cylindrical design in order to quantify materials decision and how they manifest during abuse response.

Thermoelectric generation coupling methanol steam reforming characteristic in microreactor

International Nuclear Information System (INIS)

Wang, Feng; Cao, Yiding; Wang, Guoqiang

2015-01-01

Thermoelectric (TE) generator converts heat to electric energy by thermoelectric material. However, heat removal on the cold side of the generator represents a serious challenge. To address this problem and for improved energy conversion, a thermoelectric generation process coupled with methanol steam reforming (SR) for hydrogen production is designed and analyzed in this paper. Experimental study on the cold spot character in a micro-reactor with monolayer catalyst bed is first carried out to understand the endothermic nature of the reforming as the thermoelectric cold side. A novel methanol steam reforming micro-reactor heated by waste heat or methanol catalytic combustion for hydrogen production coupled with a thermoelectric generation module is then simulated. Results show that the cold spot effect exists in the catalyst bed under all conditions, and the associated temperature difference first increases and then decreases with the inlet temperature. In the micro-reactor, the temperature difference between the reforming and heating channel outlets decreases rapidly with an increase in thermoelectric material's conductivity coefficient. However, methanol conversion at the reforming outlet is mainly affected by the reactor inlet temperature; while at the combustion outlet, it is mainly affected by the reactor inlet velocity. Due to the strong endothermic effect of the methanol steam reforming, heat supply of both kinds cannot balance the heat needed at reactor local areas, resulting in the cold spot at the reactor inlet. When the temperature difference between the thermoelectric module's hot and cold sides is 22 K, the generator can achieve an output voltage of 55 mV. The corresponding molar fraction of hydrogen can reach about 62.6%, which corresponds to methanol conversion rate of 72.6%. - Highlights: • Cold spot character of methanol steam reforming was studied through experiment. • Thermoelectric generation Coupling MSR process has been

Heat transfer characteristics of horizontal steam generators under natural circulation conditions

International Nuclear Information System (INIS)

Hyvaerinen, J.

1996-01-01

This paper deals with the heat transfer characteristics of horizontal steam generators, particularly under natural circulation (decay heat removal) conditions on the primary side. Special emphasis is on the inherent features of horizontal steam generator behaviour. A mathematical model of the horizontal steam generator primary side is developed and qualitative results are obtained analytically. A computer code, called HSG, is developed to solve the model numerically, and its predictions are compared with experimental data. The code is employed to obtain for VVER 440 steam generators quantitative results concerning the dependence of primary-to-secondary heat transfer efficiency on the primary side flow rate, temperature and secondary level. It turns out that the depletion of the secondary inventory leads to an inherent limitation of the decay energy removal in VVER steam generators. The limitation arises as a consequence of the steam generator tube bundle geometry. As an example, it is shown that the grace period associated with pressurizer safety valve opening during a station black-out is 2 1/2-3 hours instead of the 5-6 hours reported in several earlier studies. (However, the change in core heat-up timing is much less-about 1 h at most.) The heat transfer limitation explains the fact that, in the Greifswald VVER 440 station black-out accident in 1975, the steam generators never boiled dry. In addition, the stability of single-phase natural circulation is discussed and insights on the modelling of horizontal steam generators with general-purpose thermal-hydraulic system codes are also presented. (orig.)

The hierarchy of controls on snowmelt-runoff generation over seasonally-frozen hillslopes

OpenAIRE

Coles, Anna E.; Appels, Willemijn M.; McConkey, Brian G.; McDonnell, Jeffrey J.

2016-01-01

Understanding and modeling snowmelt-runoff generation in seasonally-frozen regions is a major challenge in hydrology. Partly, this is because the controls on hillslope-scale snowmelt-runoff generation are potentially extensive and their hierarchy is poorly understood. Understanding the relative importance of controls (e.g. topography, vegetation, land use, soil characteristics, and precipitation dynamics) on runoff response is necessary for model development, spatial extrapolation, and runoff...

Understanding the undelaying mechanism of HA-subtyping in the level of physic-chemical characteristics of protein.

Science.gov (United States)

Ebrahimi, Mansour; Aghagolzadeh, Parisa; Shamabadi, Narges; Tahmasebi, Ahmad; Alsharifi, Mohammed; Adelson, David L; Hemmatzadeh, Farhid; Ebrahimie, Esmaeil

2014-01-01

The evolution of the influenza A virus to increase its host range is a major concern worldwide. Molecular mechanisms of increasing host range are largely unknown. Influenza surface proteins play determining roles in reorganization of host-sialic acid receptors and host range. In an attempt to uncover the physic-chemical attributes which govern HA subtyping, we performed a large scale functional analysis of over 7000 sequences of 16 different HA subtypes. Large number (896) of physic-chemical protein characteristics were calculated for each HA sequence. Then, 10 different attribute weighting algorithms were used to find the key characteristics distinguishing HA subtypes. Furthermore, to discover machine leaning models which can predict HA subtypes, various Decision Tree, Support Vector Machine, Naïve Bayes, and Neural Network models were trained on calculated protein characteristics dataset as well as 10 trimmed datasets generated by attribute weighting algorithms. The prediction accuracies of the machine learning methods were evaluated by 10-fold cross validation. The results highlighted the frequency of Gln (selected by 80% of attribute weighting algorithms), percentage/frequency of Tyr, percentage of Cys, and frequencies of Try and Glu (selected by 70% of attribute weighting algorithms) as the key features that are associated with HA subtyping. Random Forest tree induction algorithm and RBF kernel function of SVM (scaled by grid search) showed high accuracy of 98% in clustering and predicting HA subtypes based on protein attributes. Decision tree models were successful in monitoring the short mutation/reassortment paths by which influenza virus can gain the key protein structure of another HA subtype and increase its host range in a short period of time with less energy consumption. Extracting and mining a large number of amino acid attributes of HA subtypes of influenza A virus through supervised algorithms represent a new avenue for understanding and

Understanding the undelaying mechanism of HA-subtyping in the level of physic-chemical characteristics of protein.

Directory of Open Access Journals (Sweden)

Mansour Ebrahimi

Full Text Available The evolution of the influenza A virus to increase its host range is a major concern worldwide. Molecular mechanisms of increasing host range are largely unknown. Influenza surface proteins play determining roles in reorganization of host-sialic acid receptors and host range. In an attempt to uncover the physic-chemical attributes which govern HA subtyping, we performed a large scale functional analysis of over 7000 sequences of 16 different HA subtypes. Large number (896 of physic-chemical protein characteristics were calculated for each HA sequence. Then, 10 different attribute weighting algorithms were used to find the key characteristics distinguishing HA subtypes. Furthermore, to discover machine leaning models which can predict HA subtypes, various Decision Tree, Support Vector Machine, Naïve Bayes, and Neural Network models were trained on calculated protein characteristics dataset as well as 10 trimmed datasets generated by attribute weighting algorithms. The prediction accuracies of the machine learning methods were evaluated by 10-fold cross validation. The results highlighted the frequency of Gln (selected by 80% of attribute weighting algorithms, percentage/frequency of Tyr, percentage of Cys, and frequencies of Try and Glu (selected by 70% of attribute weighting algorithms as the key features that are associated with HA subtyping. Random Forest tree induction algorithm and RBF kernel function of SVM (scaled by grid search showed high accuracy of 98% in clustering and predicting HA subtypes based on protein attributes. Decision tree models were successful in monitoring the short mutation/reassortment paths by which influenza virus can gain the key protein structure of another HA subtype and increase its host range in a short period of time with less energy consumption. Extracting and mining a large number of amino acid attributes of HA subtypes of influenza A virus through supervised algorithms represent a new avenue for

Research on Distributed PV Storage Virtual Synchronous Generator System and Its Static Frequency Characteristic Analysis

Directory of Open Access Journals (Sweden)

Xiangwu Yan

2018-03-01

Full Text Available The increasing penetration rate of grid connected renewable energy power generation reduces the primary frequency regulation capability of the system and poses a challenge to the security and stability of the power grid. In this paper, a distributed photovoltaic (PV storage virtual synchronous generator system is constructed, which realizes the external characteristics of synchronous generator/motor. For this kind of input/output bidirectional devices (e.g., renewable power generation/storage combined systems, pumped storage power stations, battery energy storage systems, and vehicle-to-grid electric vehicles, a synthesis analysis method for system power-frequency considering source-load static frequency characteristics (S-L analysis method is proposed in order to depict the system’s power balance dynamic adjustment process visually. Simultaneously, an inertia matching method is proposed to solve the problem of inertia matching in the power grid. Through the simulation experiment in MATLAB, the feasibility of the distributed PV storage synchronous virtual machine system is verified as well as the effectiveness of S-L analysis method and inertia matching method.

Understanding the electrical characteristics of micromotors

Science.gov (United States)

Emadi, Ali; Irudayaraj, Sujay S.

2005-06-01

This paper presents a comprehensive list of issues related to the electrical characteristics of both electrostatic and electromagnetic micromotors and aims at understanding the behavior of the micromotor from the electrical standpoint. The paper takes the step-by-step approach by first presenting an overview of the laws of electrostatics and electromagnetism for micromachines, their applicability, features and limitations, and then progresses to independently analyze some of the important machine related quantities like electromotive torque, force-output, angular frequencies, supply conditions and requirements, for different types of electrostatic and electromagnetic micromotor constructions. A thorough study on the electric machine parameters that affect the performance of the micromotor need to be performed, since it would serve as a useful link in integrating the micromachine output performance with the fabrication process and challenges associated with it. Achieving such integration would then determine the optimized working condition for the micromotor. The main reason for this study is that although significant advancements have fostered the growth of micromotors in the recent past which has led to the establishment of the micromotor as quite a remarkable machine for powering micromechanical devices, and also as an industrial requirement for various applications, there has always been a concern about the optimal performance of the micromotor, since there is more than just one technology that is being incorporated to realize the micromotor. With fields ranging from surface engineering and chemistry to material science engineering exerting influence on the micromotor design, it becomes very important to completely comprehend the electrophysics of the micromachine that would in turn interact with the science of fabrication to result in the development of better micromotors with considerably less functional complexity.

A review on paint sludge from automotive industries: Generation, characteristics and management.

Science.gov (United States)

Salihoglu, Guray; Salihoglu, Nezih Kamil

2016-03-15

The automotive manufacturing process results in the consumption of several natural sources and the generation of various types of wastes. The primary source of hazardous wastes at an automotive manufacturing plant is the painting process, and the major waste fraction is paint sludge, which is classified with EU waste code of 080113* implying hazardous characteristics. The amount of the paint sludge generated increases every year with the worldwide increase in the car production. The characteristics of the paint sludge, which mainly designate the management route, are mainly determined by the type of the paint used, application technique employed, and the chemicals applied such as flocculants, detackifiers, pH boosters, antifoam agents, and biocides as well as the dewatering techniques preferred. Major routes for the disposal of the paint sludges are incineration as hazardous waste or combustion at cement kilns. Because of high dissolved organic carbon content of the paint, the paint sludge cannot be accepted by landfills according to European Union Legislations. More investigations are needed in the field of paint sludge recycling such as recycling it as a new paint or as other formulations, or making use of the sludge for the production of construction materials. Research on the applicability of the paint sludge in composting and biogasification can also be useful. Ongoing research is currently being conducted on new application techniques to increase the effectiveness of paint transfer, which helps to prevent the generation of paint sludge. Advancements in paint and coating chemistry such as the reduction in the coating layers with its thickness also help to decrease the level of paint sludge generation. Investigations on the effects of the chemicals on the recycling potential of paint sludges and consideration of these effects by the chemical manufacturer companies would be extremely important. This review presents the formation of paint sludge, the factors

Signal Characteristics of Eddy Current Test for Intergranular Attack of Steam Generator Tubes

International Nuclear Information System (INIS)

Choi, Myung Sik; Lee, Deok Hyun; Han, Jung Ho; Hur, Do Haeng; Cho, Se Gon; Yim, Chang Jae

2002-01-01

Because intergranular attack (IGA), one of the localized corrosion forms occurring on steam generator tubes, can not be fabricated by an electric discharge machining method, there are few data for the eddy current test (ECT) characteristics of IGA. In this paper, the characteristics of eddy current signals are evaluated using nonexpanded tubes with IGA defects formed in 0.1 M sodium tetrathionate solution at 40 .deg. C. The detectability and sizing accuracy of IGA were discussed in terms of the coil type and frequency of the ECT probes

Calibration technique and study on metrological characteristics of a high-voltage inverse square-law function generator

International Nuclear Information System (INIS)

Popov, V.P.; Semenov, A.L.

1987-01-01

The calibration technique is described, and the metrological characteristics of a high-voltage generator of the inverse-quadratic function (HGF), being a functional unit of the diagnostic system of an electrodynamic analyser of a ionic component of a laser plasma, is analysed. The results of HGF testing in the range of time constants of the τ=(5-25)μs function are given. Analysis of metrologic and experimental characteristics shows, that HGF with automatic calibration has quite high accurate parameters. The high accuracy of function generation is provided with the possibility of calibration and adjustment conduction under experimental working conditions. Increase of the generated pulse amplitude to several tens of kilovelts is possible. Besides, the possibility of timely function adjustment to the necessary parameter (τ) increases essentially the HGF functional possibilities

The characteristic analysis of the solar energy photovoltaic power generation system

Science.gov (United States)

Liu, B.; Li, K.; Niu, D. D.; Jin, Y. A.; Liu, Y.

2017-01-01

Solar energy is an inexhaustible, clean, renewable energy source. Photovoltaic cells are a key component in solar power generation, so thorough research on output characteristics is of far-reaching importance. In this paper, an illumination model and a photovoltaic power station output power model were established, and simulation analysis was conducted using Matlab and other software. The analysis evaluated the condition of solar energy resources in the Baicheng region in the western part of Jilin province, China. The characteristic curve of the power output from a photovoltaic power station was obtained by simulation calculation. It was shown that the monthly average output power of the photovoltaic power station is affected by seasonal changes; the output power is higher in summer and autumn, and lower in spring and winter.

Study on the Tribological Characteristics of Australian Native First Generation and Second Generation Biodiesel Fuel

Directory of Open Access Journals (Sweden)

Md Mofijur Rahman

2017-01-01

Full Text Available Biodiesels are a renewable energy source, and they have the potential to be used as alternatives to diesel fuel. The aim of this study is to investigate the wear and friction characteristics of Australian native first generation and second generation biodiesels using a four-ball tribo tester. The biodiesel was produced through a two-step transesterification process and characterized according to the American Society for Testing and Materials (ASTM standards. The tribological experiment was carried out at a constant 1800 rpm and different loads and temperatures. In addition, the surface morphology of the ball was tested by scanning electron microscope (SEM/energy dispersive X-ray spectroscopy (EDX analysis. The test results indicated that biodiesel fuels have a lower coefficient of frictions (COF and lower wear scar diameter (WSD up to 83.50% and 41.28%, respectively, compared to conventional diesel fuel. The worn surface area results showed that biodiesel fuel has a minimum percentage of C and O, except Fe, compared to diesel. In addition, the worn surface area for diesel was found (2.20%–27.92% to be higher than biodiesel. The findings of this study indicated that both first and second generation biodiesel fuels have better tribological performance than diesel fuel, and between the biodiesel fuels, macadamia biodiesel showed better lubrication performance.

Generating or developing grounded theory: methods to understand health and illness.

Science.gov (United States)

Woods, Phillip; Gapp, Rod; King, Michelle A

2016-06-01

Grounded theory is a qualitative research methodology that aims to explain social phenomena, e.g. why particular motivations or patterns of behaviour occur, at a conceptual level. Developed in the 1960s by Glaser and Strauss, the methodology has been reinterpreted by Strauss and Corbin in more recent times, resulting in different schools of thought. Differences arise from different philosophical perspectives concerning knowledge (epistemology) and the nature of reality (ontology), demanding that researchers make clear theoretical choices at the commencement of their research when choosing this methodology. Compared to other qualitative methods it has ability to achieve understanding of, rather than simply describing, a social phenomenon. Achieving understanding however, requires theoretical sampling to choose interviewees that can contribute most to the research and understanding of the phenomenon, and constant comparison of interviews to evaluate the same event or process in different settings or situations. Sampling continues until conceptual saturation is reached, i.e. when no new concepts emerge from the data. Data analysis focusses on categorising data (finding the main elements of what is occurring and why), and describing those categories in terms of properties (conceptual characteristics that define the category and give meaning) and dimensions (the variations within properties which produce specificity and range). Ultimately a core category which theoretically explains how all other categories are linked together is developed from the data. While achieving theoretical abstraction in the core category, it should be logical and capture all of the variation within the data. Theory development requires understanding of the methodology not just working through a set of procedures. This article provides a basic overview, set in the literature surrounding grounded theory, for those wanting to increase their understanding and quality of research output.

Identification of influencing municipal characteristics regarding household waste generation and their forecasting ability in Biscay.

Science.gov (United States)

Oribe-Garcia, Iraia; Kamara-Esteban, Oihane; Martin, Cristina; Macarulla-Arenaza, Ana M; Alonso-Vicario, Ainhoa

2015-05-01

The planning of waste management strategies needs tools to support decisions at all stages of the process. Accurate quantification of the waste to be generated is essential for both the daily management (short-term) and proper design of facilities (long-term). Designing without rigorous knowledge may have serious economic and environmental consequences. The present works aims at identifying relevant socio-economic features of municipalities regarding Household Waste (HW) generation by means of factor models. Factor models face two main drawbacks, data collection and identifying relevant explanatory variables within a heterogeneous group. Grouping similar characteristics observations within a group may favour the deduction of more robust models. The methodology followed has been tested with Biscay Province because it stands out for having very different municipalities ranging from very rural to urban ones. Two main models are developed, one for the overall province and a second one after clustering the municipalities. The results prove that relating municipalities with specific characteristics, improves the results in a very heterogeneous situation. The methodology has identified urban morphology, tourism activity, level of education and economic situation as the most influencing characteristics in HW generation. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Characteristics of U-tube assembly design for CANDU 6 type steam generators

International Nuclear Information System (INIS)

Park, Jun Su; Jeong, Seung Ha

1996-06-01

Since the first operation of nuclear steam generator early 1960s, its performance requirements have been met but the steam generator problems have been met but the steam generator problems have been major cause of reducing the operational reliability, plant safety and availability. U-tube assembly of steam generator forms the primary system pressure boundary of the plant and have experienced several types of tube degradation problems. Tube failure and leakage resulting from the degradation will cause radioactive contamination of secondary system by the primary coolant, and this may lead to unplanned plant outages and costly repair operations such as tube plugging or steam generator replacement. For the case of steam generators for heavy water reactors, e.g. Wolsong 2, 3, and 4 NPP, a high cost of heavy water will be imposed additionally. During the plant operation, steam generator tubes can potentially be subject to adverse environmental conditions which will cause damages to U-tube assembly. Types of the damage depend upon the combined effects of design factors, materials and chemical environment of steam generator, and they are the pure water stress corrosion cracking, intergranular attack, pitting, wastage, denting, fretting and fatigue, etc. In this report, a comprehensive review of major design factors of recirculating steam generators has been performed against the potential tube damages. Then the design characteristics of CANDU-type Wolsong steam generator were investigated in detail, including tube material, thermalhydraulic aspects, tube-to-tubesheet joint, tube supports, water chemistry and sludge management. 9 tabs., 18 figs., 38 refs. (Author) .new

Effect of heat transfer tube leak on dynamic characteristic of steam generator

International Nuclear Information System (INIS)

Sun Baozhi; Shi Jianxin; Li Na; Zheng Lusong; Liu Shanghua; Lei Yu

2015-01-01

Taking the steam generator of Daya Bay Nuclear Power Station as the research object, one-dimensional dynamic model of the steam generator based on drift flux theory and leak model of heat transfer tube were established. Steady simulation of steam generator under different conditions was carried out. Based on verifying the drift flux model and leak model of heat transfer tube, the effect of leak location and flow rate under different conditions on steam generator's key parameters was studied. The results show that the drift flux model and leak model can reflect the law of key parameter change accurately such as vapor mass fraction and steam pressure under different leak cases. The variation of the parameters is most apparent when the leak is at the entrance of boiling section and vapor mass fraction varies from 0.261 to 0.163 when leakage accounts for 5% of coolant flow rate. The successful prediction of the effect of heat transfer tube leak on dynamic characteristics of the steam generator based on drift flux theory supplies some references for monitoring and taking precautionary measures to prevent heat transfer tube leak accident. (authors)

A comparison between characteristics of atmospheric-pressure plasma jets sustained by nanosecond- and microsecond-pulse generators in helium

International Nuclear Information System (INIS)

Zhang, Cheng; Shao, Tao; Wang, Ruixue; Yan, Ping; Zhou, Zhongsheng; Zhou, Yixiao

2014-01-01

Power source is an important parameter that can affect the characteristics of atmospheric-pressure plasma jets (APPJs), because it can play a key role on the discharge characteristics and ionization process of APPJs. In this paper, the characteristics of helium APPJs sustained by both nanosecond-pulse and microsecond-pulse generators are compared from the aspects of plume length, discharge current, consumption power, energy, and optical emission spectrum. Experimental results showed that the pulsed APPJ was initiated near the high-voltage electrode with a small curvature radius, and then the stable helium APPJ could be observed when the applied voltage increased. Moreover, the discharge current of the nanosecond-pulse APPJ was larger than that of the microsecond-pulse APPJ. Furthermore, although the nanosecond-pulse generator consumed less energy than the microsecond-pulse generator, longer plume length, larger instantaneous power per pulse and stronger spectral line intensity could be obtained in the nanosecond-pulse excitation case. In addition, some discussion indicated that the rise time of the applied voltage could play a prominent role on the generation of APPJs

Challenges and Difficulties to Teaching Engineering to Generation Z: a case research

OpenAIRE

Barreiro, Suamit Correia; Bozutti, Daniel Fernando

2017-01-01

Many people from generation Z are at the beginning of their academic activities. This generation has peculiar characteristics that might be a challenge in the labor market. Thus, instructors have a great role in their preparation. However, professors might face difficulties dealing with their specific characteristics. The research aims to carry out a general survey to enable an understanding of the greater challenges and difficulties in teaching the subject of engineering to the students of G...

Understanding fifth-harmonic generation in CLBO

Science.gov (United States)

Patankar, S.; Yang, S. T.; Moody, J. D.; Bayramian, A. J.; Swadling, G. F.; Barker, D.; Datte, P.; Mennerat, G.; Norton, M.; Carr, C. W.; Begishev, I. A.; Bromage, J.; Ross, J. S.

2018-02-01

We report on results of fifth harmonic generation in Cesium Lithium Borate (CLBO) using a three-crystal cascaded frequency conversion scheme designed to study the energy balance of the final sum frequency generation stage. The experimental setup independently combines the first and fourth harmonic of a Nd:Glass laser in a 5mm thick CLBO crystal. Energy balance between the incoming and output energy is close to unity when the CLBO is out of phase matching and approximately 80% when the crystal is in phase matching. A detailed analysis of the residual fundamental and fourth harmonic energy indicates 5th harmonic light is being generated but only 26% is unaccounted for. We attribute the missing light to linear transmission loss in the CLBO oven. The ratio of the output to input energy is unity when the missing 5th harmonic is incorporated into the calculations. Two-dimensional plane wave mixing simulations show agreement with the results at lower intensities.

Characteristics of Linear MHD Generators with One or a Few Loads

Energy Technology Data Exchange (ETDEWEB)

Witalis, E A

1966-02-15

The theoretical performance of linear series segmented MHD generators with finite size electrodes and one or a few identical external loads is investigated. The analysis is an extension of our conformal mapping investigation previously reported. The electrical characteristics are evaluated as functions of the segmentation degree, the Hall parameter and the relative position of short-circuited electrodes. Special consideration is given to the influence of staggering the electrodes, i. e. shifting the relative positions of short-circuited electrodes. General electrical terminal characteristics, i. e. the full current-voltage relation, can not be obtained by the exact analytical method, which is applicable only to so-called design load conditions or infinitely long MHD channels. However, it is shown how the general properties can be explained qualitatively and calculated approximately by describing off-design modes of operation in terms of a fictitious 'effective' number of external loads.

Characteristics of Linear MHD Generators with One or a Few Loads

International Nuclear Information System (INIS)

Witalis, E.A.

1966-02-01

The theoretical performance of linear series segmented MHD generators with finite size electrodes and one or a few identical external loads is investigated. The analysis is an extension of our conformal mapping investigation previously reported. The electrical characteristics are evaluated as functions of the segmentation degree, the Hall parameter and the relative position of short-circuited electrodes. Special consideration is given to the influence of staggering the electrodes, i. e. shifting the relative positions of short-circuited electrodes. General electrical terminal characteristics, i. e. the full current-voltage relation, can not be obtained by the exact analytical method, which is applicable only to so-called design load conditions or infinitely long MHD channels. However, it is shown how the general properties can be explained qualitatively and calculated approximately by describing off-design modes of operation in terms of a fictitious 'effective' number of external loads

Workplace-related generational characteristics of nurses: A mixed-method systematic review.

Science.gov (United States)

Stevanin, Simone; Palese, Alvisa; Bressan, Valentina; Vehviläinen-Julkunen, Katri; Kvist, Tarja

2018-06-01

The aim of this study was to describe and summarize workplace characteristics of three nursing generations: Baby Boomers, Generations X and Y. Generational differences affect occupational well-being, nurses' performance, patient outcomes and safety; therefore, nurse managers, administrators and educators are interested increasingly in making evidence-based decisions about the multigenerational nursing workforce. Mixed-method systematic review. Medline, CINAHL, PsycINFO and Scopus (January 1991-January 2017). (1) The Joanna Briggs Institute's method for conducting mixed-method systematic reviews; (2) the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and (3) the Enhancing Transparency in Reporting the Synthesis of Qualitative Research guidelines. The studies' methodological quality was assessed with the Mixed-Methods Appraisal Tool. Quantitative and mixed-method studies were transformed into qualitative methods using a convergent qualitative synthesis and qualitative findings were combined with a narrative synthesis. Thirty-three studies were included with three main themes and 11 subthemes: (1) Job attitudes (work engagement; turnover intentions, reasons for leaving; reasons, incentives/disincentives to continue nursing); (2) Emotion-related job aspects (stress/resilience; well-being/job satisfaction; affective commitment; unit climate; work ethic) and (3) Practice and leadership-related aspects (autonomy; perceived competence; leadership relationships and perceptions). Baby Boomers reported lower levels of stress and burnout than did Generations X and Y, different work engagement, factors affecting workplace well-being and retention and greater intention to leave compared with Generation Y, which was less resilient, but more cohesive. Although several studies reported methodological limitations and conflicting findings, generational differences in nurses' job attitudes, emotional, practice and leadership factors should be considered to enhance

Issues and Advances in Understanding Landslide-Generated Tsunamis: Toward a Unified Model

Science.gov (United States)

Geist, E. L.; Locat, J.; Lee, H. J.; Lynett, P. J.; Parsons, T.; Kayen, R. E.; Hart, P. E.

2008-12-01

The physics of tsunamis generated from submarine landslides is highly complex, involving a cross- disciplinary exchange in geophysics. In the 10 years following the devastating Papua New Guinea tsunami, there have been significant advances in understanding landslide-generated tsunamis. However, persistent issues still remain related to submarine landslide dynamics that may be addressed with collection of new marine geologic and geophysical observations. We review critical elements of landslide tsunamis in the hope of developing a unified model that encompasses all stages of the process from triggering to tsunami runup. Because the majority of non-volcanogenic landslides that generate tsunamis are triggered seismically, advances in understanding inertial displacements and changes in strength and rheologic properties in response to strong-ground motion need to be included in a unified model. For example, interaction between compliant marine sediments and multi-direction ground motion results in greater permanent plastic displacements than predicted by traditional rigid-block analysis. When considering the coupling of the overlying water layer in the generation of tsunamis, the post-failure dynamics of landslides is important since the overall rate of seafloor deformation for landslides is less than or comparable to the phase speed of tsunami waves. As such, the rheologic and mechanical behavior of the slide material needs to be well understood. For clayey and silty debris flows, a non-linear (Herschel-Bulkley) and bilinear rheology have recently been developed to explain observed runout distances and deposit thicknesses. An additional complexity to this rheology is the inclusion of hydrate-laden sediment that commonly occurs along continental slopes. Although it has been proposed in the past that gas hydrate dissociation may provide potential failure planes for slide movement, it is unclear how zones of rigid hydrate-bearing sediment surrounded by a more viscoplastic

Understanding and Teaching Generation Y

Science.gov (United States)

Reilly, Peter

2012-01-01

English teaching professionals working with children in primary school, adolescents in secondary school, or adults at university know that learners nowadays think and behave differently than those from previous generations. These students were born into a world of information technology; they prefer to multitask rather than focus on one thing at a…

On identities of free finitely generated alternative algebras over a field of characteristic 3

International Nuclear Information System (INIS)

Pchelintsev, S V

2001-01-01

In 1981 Filippov solved in the affirmative Shestakov's problem on the strictness of the inclusions in the chains of varieties generated by free alternative and Mal'cev algebras of finite rank over a field of characteristic distinct from 2 and 3. In the present paper an analogous result is proved for alternative algebras over a field of characteristic 3. The proof is based on the construction of three families of identities that hold on the algebras of the corresponding rank. A disproof of the identities on algebras of larger rank is carried out with the help of a prime commutative alternative algebra. It is also proved that in varieties of alternative algebras of finite basis rank over a field of characteristic 3 every soluble algebra is nilpotent

Two-Phase Instability Characteristics of Printed Circuit Steam Generator for the Low Pressure Condition

International Nuclear Information System (INIS)

Kang, Han-Ok; Han, Hun Sik; Kim, Young-In; Kim, Keung Koo

2015-01-01

Reduction of installation space for steam generators can lead to much smaller reactor vessel with resultant decrease of overall manufacturing cost for the components. A PCHE(Printed Circuit Heat Exchanger) is one of the compact types of heat exchangers available as an alternative to conventional shell and tube heat exchangers. Its name is derived from the procedure used to manufacture the flat metal plates that form the core of the heat exchanger, which is done by chemical milling. These plates are then stacked and diffusion bonded, converting the plates into a solid metal block containing precisely engineered fluid flow passages. PCSG(Printed Circuit Steam Generator) is a potential candidate to be applied to the integral reactor with its compactness and mechanical robustness. For the introduction of new steam generator, design requirement for the two-phase flow instability should be considered. This paper describes two-phase flow instability characteristics of PCSG for the low pressure condition. PCSG is a potential candidate to be applied to the integral reactor with its compactness and mechanical robustness. Interconnecting flow path was developed to mitigate the two-phase flow instability in the cold side. The flow characteristics of two-phase flow instability at the PCSG is examined experimentally in this study

Multi generations in the workforce: Building collaboration

Directory of Open Access Journals (Sweden)

Vasanthi Srinivasan

2012-03-01

Full Text Available Organisations the world over in today's rapid growth context are faced with the challenge of understanding a multi-generational workforce and devising policies and processes to build collaboration between them. In its first part, this article synthesises the literature on generational studies, with emphasis on the definition of generations and the characteristics of the generational cohorts. It emphasises that such studies are embedded in the socio-economic-cultural-context and India-specific scholarship must take into account the demographic and economic variations across the country. It then discusses the challenges of multi-generations in the Indian workforce, their impact on leadership styles and managerial practices, and the task of building inter-generational collaboration with an eminent panel of practitioners and researchers.

Current generation: challenges to the society or time?

Directory of Open Access Journals (Sweden)

Artsimovich I.V.

2017-02-01

Full Text Available the article is devoted to the understanding of the difficulties of psycho-pedagogical influence on the modern younger generation and analysis of their psychological characteristics. The article demonstrates a need for new forms, ways, and means of psychological and pedagogical impact and modernization of pedagogical education.

Horizontal steam generator thermal-hydraulics

Energy Technology Data Exchange (ETDEWEB)

Ubra, O. [SKODA Praha Company, Prague (Czechoslovakia); Doubek, M. [Czech Technical Univ., Prague (Czechoslovakia)

1995-09-01

Horizontal steam generators are typical components of nuclear power plants with pressure water reactor type VVER. Thermal-hydraulic behavior of horizontal steam generators is very different from the vertical U-tube steam generator, which has been extensively studied for several years. To contribute to the understanding of the horizontal steam generator thermal-hydraulics a computer program for 3-D steady state analysis of the PGV-1000 steam generator has been developed. By means of this computer program, a detailed thermal-hydraulic and thermodynamic study of the horizontal steam generator PGV-1000 has been carried out and a set of important steam generator characteristics has been obtained. The 3-D distribution of the void fraction and 3-D level profile as functions of load and secondary side pressure have been investigated and secondary side volumes and masses as functions of load and pressure have been evaluated. Some of the interesting results of calculations are presented in the paper.

Characteristics of Helicopter-Generated and Volcano-Related Seismic Tremor Signals

Science.gov (United States)

Eibl, Eva P. S.; Lokmer, Ivan; Bean, Christopher J.; Akerlie, Eggert; Vogfjörd, Kristin S.

2017-04-01

In volcanic environments it is crucial to distinguish between man-made seismic signals and signals created by the volcano. We compare volcanic, seismic signals with helicopter generated, seismic signals recorded in the last 2.5 years in Iceland. In both cases a long-lasting, emergent seismic signal, that can be referred to as seismic tremor, was generated. In the case of a helicopter, the rotating blades generate pressure pulses that travel through the air and excite Rayleigh waves at up to 40 km distance depending on wind speed, wind direction and topographic features. The longest helicopter related seismic signal we recorded was at the order of 40 minutes long. The tremor usually has a fundamental frequency of more than 10 Hz and overtones at integers of the fundamental frequency. Changes in distance lead to either increases or decreases of the frequency due to the Doppler Effect and are strongest for small source-receiver distances. The volcanic tremor signal was recorded during the Bardarbunga eruption at Holuhraun in 2014/15. For volcano-related seismic signals it is usually more difficult to determine the source process that generated the tremor. The pre-eruptive tremor persists for 2 weeks, while the co-eruptive tremor lasted for 6 months. We observed no frequency changes, most energy between 1 and 2 Hz and no or very little energy above 5 Hz. We compare the different characteristics of helicopter-related and volcano-related seismic signals and discuss how they can be distinguished. In addition we discuss how we can determine if a frequency change is related to a moving source or change in repeat time or a change in the geometry of the resonating body.

Speeding by young novice drivers: What can personal characteristics and psychosocial theory add to our understanding?

Science.gov (United States)

Scott-Parker, Bridie; Hyde, Melissa K; Watson, Barry; King, Mark J

2013-01-01

Young novice drivers continue to be overrepresented in fatalities and injuries arising from crashes even with the introduction of countermeasures such as graduated driver licensing (GDL). Enhancing countermeasures requires a better understanding of the variables influencing risky driving. One of the most common risky behaviours performed by drivers of all ages is speeding, which is particularly risky for young novice drivers who, due to their driving inexperience, have difficulty in identifying and responding appropriately to road hazards. Psychosocial theory can improve our understanding of contributors to speeding, thereby informing countermeasure development and evaluation. This paper reports an application of Akers' social learning theory (SLT), augmented by Gerrard and Gibbons' prototype/willingness model (PWM), in addition to personal characteristics of age, gender, car ownership, and psychological traits/states of anxiety, depression, sensation seeking propensity and reward sensitivity, to examine the influences on self-reported speeding of young novice drivers with a Provisional (intermediate) licence in Queensland, Australia. Young drivers (n=378) recruited in 2010 for longitudinal research completed two surveys containing the Behaviour of Young Novice Drivers Scale, and reported their attitudes and behaviours as pre-Licence/Learner (Survey 1) and Provisional (Survey 2) drivers and their sociodemographic characteristics. An Akers' measurement model was created. Hierarchical multiple regressions revealed that (1) personal characteristics (PC) explained 20.3%; (2) the combination of PC and SLT explained 41.1%; (3) the combination of PC, SLT and PWM explained 53.7% of variance in self-reported speeding. Whilst there appeared to be considerable shared variance, the significant predictors in the final model included gender, car ownership, reward sensitivity, depression, personal attitudes, and Learner speeding. These results highlight the capacity for

Next generation of psychiatrists: What is needed in training?

Science.gov (United States)

Bernstein, Carol A; Bhugra, Dinesh

2011-06-01

Populations can be divided into generations. Each generation has its own characteristics and even though not every member of the same generation will share characteristics with other members of that generation, it is possible to identify generational differences. Generations frequently have different values and varying styles of functioning and learning. Since the Second World War, the generations can be divided into four cohorts: the Veterans, the Baby Boomers, Generation X, and the Millennials. Each generation has a collective identity and, in addition to understanding cultural and ethnic differences, these generational differences should also be taken into account in the teaching arena. Values and beliefs about work-life balance, learning styles, comfort with technology, methods of communication, and approaches to leadership are the types of parameters which vary across generations. As a result, medical educators would benefit from appreciating these differences in order to enhance the learning of medical students and residents and to better prepare them for delivering patient care in the twenty-first century. In this paper, the authors highlight some of the challenges and issues related to these generational divides. Copyright © 2011 Elsevier B.V. All rights reserved.

Understanding the Generation of Network Bursts by Adaptive Oscillatory Neurons

Directory of Open Access Journals (Sweden)

Tanguy Fardet

2018-02-01

Full Text Available Experimental and numerical studies have revealed that isolated populations of oscillatory neurons can spontaneously synchronize and generate periodic bursts involving the whole network. Such a behavior has notably been observed for cultured neurons in rodent's cortex or hippocampus. We show here that a sufficient condition for this network bursting is the presence of an excitatory population of oscillatory neurons which displays spike-driven adaptation. We provide an analytic model to analyze network bursts generated by coupled adaptive exponential integrate-and-fire neurons. We show that, for strong synaptic coupling, intrinsically tonic spiking neurons evolve to reach a synchronized intermittent bursting state. The presence of inhibitory neurons or plastic synapses can then modulate this dynamics in many ways but is not necessary for its appearance. Thanks to a simple self-consistent equation, our model gives an intuitive and semi-quantitative tool to understand the bursting behavior. Furthermore, it suggests that after-hyperpolarization currents are sufficient to explain bursting termination. Through a thorough mapping between the theoretical parameters and ion-channel properties, we discuss the biological mechanisms that could be involved and the relevance of the explored parameter-space. Such an insight enables us to propose experimentally-testable predictions regarding how blocking fast, medium or slow after-hyperpolarization channels would affect the firing rate and burst duration, as well as the interburst interval.

Industrial Special Wastes Generated in Iowa and Manpower Characteristics of Employee Handlers, Volume I.

Science.gov (United States)

Pierce, David R.

This document, Vol. I in a set, presents information obtained from a survey of industry in Iowa to determine the use and quantities, distribution, and treatment and disposal practices of hazardous waste generators. Additionally, it tabulated the number and manpower characteristics of employees who are in daily contact with such hazardous…

3D electromagnetic design and electrical characteristics analysis of a 10-MW-class hightemperature superconducting synchronous generator for wind power

International Nuclear Information System (INIS)

Kim, J. H.; Park, S. I.; Le, T. D.; Kim, H. M.

2014-01-01

In this paper, the general electromagnetic design process of a 10-MW-class high-temperature superconducting (HTS) synchronous generator that is intended to be utilized for large scale offshore wind generator is discussed. This paper presents three-dimensional (3D) electromagnetic design proposal and electrical characteristic analysis results of a 10-MW-class HTS synchronous generator for wind power. For more detailed design by reducing the errors of a two-dimensional (2D) design owing to leakage flux in air-gap, we redesign and analyze the 2D conceptual electromagnetic design model of the HTS synchronous generator using 3D finite element analysis (FEA) software. Then electrical characteristics which include the no-load and full-load voltage of generator, harmonic contents of these two load conditions, voltage regulation and losses of generator are analyzed by commercial 3D FEA software.

Discovering Shared Experiences of Second Generation Community College Employees: A Grounded Theory Study

Science.gov (United States)

Studebaker, Eric J.

2012-01-01

The second generation community college employee had not been a target population of any previous research in the field of higher education. This study added to a broader understanding of employees, their various characteristics, and the implications of those characteristics. The purpose of this study was to develop a grounded theory defining the…

Surface runoff generation in a small watershed covered by sugarcane and riparian forest

Directory of Open Access Journals (Sweden)

Rafael Pires Fernandes

2013-12-01

Full Text Available Since an understanding of how runoff is generated is of great importance to soil conservation, to water availability and to the management of a watershed, the objective of this study was to understand the generation of surface runoff in a watershed covered by sugarcane and riparian forest. Nine surface runoff plots were set up, evenly distributed on the lower, middle and upper slopes. The lower portion was covered by riparian forest. We showed that the average surface runoff coefficient along the slope in the present study was higher than in other studies under different land uses. Furthermore, the surface runoff was higher under sugarcane compared to the riparian forest, especially after sugarcane harvesting. Besides land cover, other factors such as the characteristics of rainfall events, relief and physical soil characteristics such as soil bulk density and saturated hydraulic conductivity influenced the surface runoff generation.

Mathematical simulation of processes in horizontal steam generator and the program of calculation of its characteristics

Energy Technology Data Exchange (ETDEWEB)

Titov, V.F.; Zorin, V.M.; Gorburov, V.I. [OKB Gidropress, Moscow Energy Inst. (Russian Federation)

1995-12-31

On the basis of mathematical models describing the processes in horizontal steam generator (SG) the code giving the possibility to calculate the hydrodynamical characteristics in any point of water volume, has been developed. The code simulates the processes in SG in the stationary (or quasi-stationary) mode or operation only. The code may be used as a next step to calculations of the SG characteristics in the non-stationary modes of operation.

Mathematical simulation of processes in horizontal steam generator and the program of calculation of its characteristics

Energy Technology Data Exchange (ETDEWEB)

Titov, V F; Zorin, V M; Gorburov, V I [OKB Gidropress, Moscow Energy Inst. (Russian Federation)

1996-12-31

On the basis of mathematical models describing the processes in horizontal steam generator (SG) the code giving the possibility to calculate the hydrodynamical characteristics in any point of water volume, has been developed. The code simulates the processes in SG in the stationary (or quasi-stationary) mode or operation only. The code may be used as a next step to calculations of the SG characteristics in the non-stationary modes of operation.

Investigations of the Sound Generated by Supercavity Ventilation

Science.gov (United States)

2009-08-20

2 1.2.2 Supercavitating vehicles . . . . . . . . . . . . . . . . . . . . . . . 3 1.2.3...1.1 Motivation The successful development of high-speed supercavitating underwater vehicles is an im- portant U.S. Navy objective. All aspects of...provide naval researchers with an understanding of the characteristics of the sound generated by the ventilating jets of a supercavitating vehicle

Investigations of the gas-side heat transfer and flow characteristics of steam generators in AGR stations

Energy Technology Data Exchange (ETDEWEB)

Lis, J [Central Electricity Research Laboratories, Leatherhead, Surrey (United Kingdom)

1984-07-01

This paper describes the experimental and analytical investigations of the gas-side heat transfer and flow characteristics of steam generators in the AGR stations carried out by CERL. The majority of the experimental work on heat transfer and flow characteristics of close-packed tube arrangements in cross-flow of gases is carried out in a pressurised heat exchanger rig. The rig is operated on-line by a dedicated PDP 11/40 computer over the range of Reynolds number 10{sup 4} to 3x10{sup 5}. Atmospheric wind tunnels employing either small or large scale models of the specific sections of steam generators are used for a variety of supplementary and development studies. Various measurements techniques and, in particular, LDA and hot wire anemometry employed in these studies are described. The more important aspects of various investigations are illustrated by typical results. In order to ensure the efficient operation and integrity of steam generators under asymmetric boundary conditions a MIX suite of 2-dimensional codes has been developed. The codes calculate the gas and water/steam flow and temperature distributions in each channel of the steam generator taking into account thermal mixing in the gas as it passes through the generator. Application of the MIX codes to the solution of various operational problems is illustrated by typical examples and the continuing exercise of validating the codes against plant operational data is discussed. (author)

Investigations of the gas-side heat transfer and flow characteristics of steam generators in AGR stations

International Nuclear Information System (INIS)

Lis, J.

1984-01-01

This paper describes the experimental and analytical investigations of the gas-side heat transfer and flow characteristics of steam generators in the AGR stations carried out by CERL. The majority of the experimental work on heat transfer and flow characteristics of close-packed tube arrangements in cross-flow of gases is carried out in a pressurised heat exchanger rig. The rig is operated on-line by a dedicated PDP 11/40 computer over the range of Reynolds number 10 4 to 3x10 5 . Atmospheric wind tunnels employing either small or large scale models of the specific sections of steam generators are used for a variety of supplementary and development studies. Various measurements techniques and, in particular, LDA and hot wire anemometry employed in these studies are described. The more important aspects of various investigations are illustrated by typical results. In order to ensure the efficient operation and integrity of steam generators under asymmetric boundary conditions a MIX suite of 2-dimensional codes has been developed. The codes calculate the gas and water/steam flow and temperature distributions in each channel of the steam generator taking into account thermal mixing in the gas as it passes through the generator. Application of the MIX codes to the solution of various operational problems is illustrated by typical examples and the continuing exercise of validating the codes against plant operational data is discussed. (author)

Research on the Combustion Characteristics of a Free-Piston Gasoline Engine Linear Generator during the Stable Generating Process

Directory of Open Access Journals (Sweden)

Yuxi Miao

2016-08-01

Full Text Available The free-piston gasoline engine linear generator (FPGLG is a new kind of power plant consisting of free-piston gasoline engines and a linear generator. Due to the elimination of the crankshaft mechanism, the piston motion process and the combustion heat release process affect each other significantly. In this paper, the combustion characteristics during the stable generating process of a FPGLG were presented using a numerical iteration method, which coupled a zero-dimensional piston dynamic model and a three-dimensional scavenging model with the combustion process simulation. The results indicated that, compared to the conventional engine (CE, the heat release process of the FPGLG lasted longer with a lower peak heat release rate. The indicated thermal efficiency of the engine was lower because less heat was released around the piston top dead centre (TDC. Very minimal difference was observed on the ignition delay duration between the FPGLG and the CE, while the post-combustion period of the FPGLG was significantly longer than that of the CE. Meanwhile, the FPGLG was found to operate more moderately due to lower peak in-cylinder gas pressure and a lower pressure rising rate. The potential advantage of the FPGLG in lower NOx emission was also proven with the simulation results presented in this paper.

Generational Influences in Academic Emergency Medicine: Teaching and Learning, Mentoring, and Technology (Part I)

Science.gov (United States)

Mohr, Nicholas M.; Moreno-Walton, Lisa; Mills, Angela M.; Brunett, Patrick H.; Promes, Susan B.

2010-01-01

For the first time in history, four generations are working together – Traditionalists, Baby Boomers, Generation Xers, and Millennials. Members of each generation carry with them a unique perspective of the world and interact differently with those around them. Through a review of the literature and consensus by modified Delphi methodology of the Society for Academic Emergency Medicine (SAEM) Aging and Generational Issues Task Force, the authors have developed this two-part series to address generational issues present in academic emergency medicine (EM). Understanding generational characteristics and mitigating strategies can help address some common issues encountered in academic EM. Through recognition of the unique characteristics of each of the generations with respect to teaching and learning, mentoring, and technology, academicians have the opportunity to strategically optimize interactions with one another. PMID:21314779

Statistical characteristic in time-domain of direct current corona-generated audible noise from conductor in corona cage

Energy Technology Data Exchange (ETDEWEB)

Li, Xuebao, E-mail: lxb08357x@ncepu.edu.cn; Cui, Xiang, E-mail: x.cui@ncepu.edu.cn; Ma, Wenzuo; Bian, Xingming; Wang, Donglai [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206 (China); Lu, Tiebing, E-mail: tiebinglu@ncepu.edu.cn [Beijing Key Laboratory of High Voltage and EMC, North China Electric Power University, Beijing 102206 (China); Hiziroglu, Huseyin [Department of Electrical and Computer Engineering, Kettering University, Flint, Michigan 48504 (United States)

2016-03-15

The corona-generated audible noise (AN) has become one of decisive factors in the design of high voltage direct current (HVDC) transmission lines. The AN from transmission lines can be attributed to sound pressure pulses which are generated by the multiple corona sources formed on the conductor, i.e., transmission lines. In this paper, a detailed time-domain characteristics of the sound pressure pulses, which are generated by the DC corona discharges formed over the surfaces of a stranded conductors, are investigated systematically in a laboratory settings using a corona cage structure. The amplitude of sound pressure pulse and its time intervals are extracted by observing a direct correlation between corona current pulses and corona-generated sound pressure pulses. Based on the statistical characteristics, a stochastic model is presented for simulating the sound pressure pulses due to DC corona discharges occurring on conductors. The proposed stochastic model is validated by comparing the calculated and measured A-weighted sound pressure level (SPL). The proposed model is then used to analyze the influence of the pulse amplitudes and pulse rate on the SPL. Furthermore, a mathematical relationship is found between the SPL and conductor diameter, electric field, and radial distance.

Statistical characteristic in time-domain of direct current corona-generated audible noise from conductor in corona cage

Science.gov (United States)

Li, Xuebao; Cui, Xiang; Lu, Tiebing; Ma, Wenzuo; Bian, Xingming; Wang, Donglai; Hiziroglu, Huseyin

2016-03-01

The corona-generated audible noise (AN) has become one of decisive factors in the design of high voltage direct current (HVDC) transmission lines. The AN from transmission lines can be attributed to sound pressure pulses which are generated by the multiple corona sources formed on the conductor, i.e., transmission lines. In this paper, a detailed time-domain characteristics of the sound pressure pulses, which are generated by the DC corona discharges formed over the surfaces of a stranded conductors, are investigated systematically in a laboratory settings using a corona cage structure. The amplitude of sound pressure pulse and its time intervals are extracted by observing a direct correlation between corona current pulses and corona-generated sound pressure pulses. Based on the statistical characteristics, a stochastic model is presented for simulating the sound pressure pulses due to DC corona discharges occurring on conductors. The proposed stochastic model is validated by comparing the calculated and measured A-weighted sound pressure level (SPL). The proposed model is then used to analyze the influence of the pulse amplitudes and pulse rate on the SPL. Furthermore, a mathematical relationship is found between the SPL and conductor diameter, electric field, and radial distance.

THE GENERATIVE REPRODUCTIVE CHARACTERISTICS OF RED DRAGON FRUIT (Hylocereus.polyrhizus (Web. Britton & Rose, CACTACEAE

Directory of Open Access Journals (Sweden)

Eniek Kriswiyanti

2013-04-01

Full Text Available This study aimed to investigate the generative reproductive characteristics of red dragon fruit (Hylocereus polyrhizus (Web. Britton & Rose, that is the characteristics and the development of male and female reproductive system and the embryo. The flowering morphology was observed through the gametogenesis process and the process of embryogenesis was observed using the methods of squash, cytolysis, and embedding of flower before anthesis, during and after anthesis. The results showed that the flower funnelled form with many calyxes, stamens and crowns. The pollen was circular, sulcus, trilate, reticulate, and spheroid. The development of microgametophyte was at the 2nd stages with three nucleuses and the pistil developed after anthesis.  Anthesis was taken place at night time, fertilization and pollen developed before anthesis and has not germinating. A single pistil, the head of pistil with many branches, the style longer than the stamen, open type.  Seeds anathrophus, endosperm and embryo with the globular shaped, developed 5 days after anthesis, the embryo torpedo likes and the differentiation of primer tissues seen in the seeds 7 days after anthesis, and arilus generated from development of megasporangium. Keywords: embedding, self incompatibility, sferoidal, anatrophus, arillus.

Understanding social acceptance of electricity generation sources

International Nuclear Information System (INIS)

Bronfman, Nicolás C.; Jiménez, Raquel B.; Arévalo, Pilar C.; Cifuentes, Luis A.

2012-01-01

Social acceptability is a determinant factor in the failure or success of the government's decisions about which electricity generation sources will satisfy the growing demand for energy. The main goal of this study was to validate a causal trust-acceptability model for electricity generation sources. In the model, social acceptance of an energy source is directly caused by perceived risk and benefit and also by social trust in regulatory agencies (both directly and indirectly, through perceived risk and benefit). Results from a web-based survey of Chilean university students demonstrated that data for energy sources that are controversial in Chilean society (fossil fuels, hydro, and nuclear power) fit the hypothesized model, whereas data for non conventional renewable energy sources (solar, wind, geothermal and tidal) did not. Perceived benefit had the greatest total effect on acceptability, thus emerging as a key predictive factor of social acceptability of controversial electricity generation sources. Further implications for regulatory agencies are discussed. - Highlights: ► We tested a causal trust-acceptability model for electricity generation sources in Chile. ► Data for controversial energy sources in the Chilean society (fossil fuels, hydro and nuclear power) fit the hypothesized model. ► Data for non conventional renewable energy sources did not fit the data. ► Perceived benefit showed the greatest total effect on acceptability.

Understanding fine structure constants and three generations

International Nuclear Information System (INIS)

Bennett, D.L.; Nielsen, H.B.

1988-02-01

We put forward a model inspired by random dynamics that relates the smallness of the gauge coupling constants to the number of generations being 'large'. The new element in the present version of our model is the appearance of a free parameter χ that is a measure of the (presumably relatively minor) importance of a term in the plaquette action proportional to the trace in the (1/6, 2, 3) representation of the Standard Model. Calling N gen the number of generations, the sets of allowed (N gen , χN gen )-pairs obtained by imposing the three measured coupling constant values of the Standard Model form three lines. In addition to finding that these lines cross at a single point (as needed for a consistent fit), the intersection occurs with surprising accuracy at the integer N gen = 3 (thereby predicting exactly three generations). It is also encouraging that the parameter χ turns out to be small and positive as expected. (orig.)

Generational influences in academic emergency medicine: teaching and learning, mentoring, and technology (part I).

Science.gov (United States)

Mohr, Nicholas M; Moreno-Walton, Lisa; Mills, Angela M; Brunett, Patrick H; Promes, Susan B

2011-02-01

For the first time in history, four generations are working together-traditionalists, baby boomers, generation Xers (Gen Xers), and millennials. Members of each generation carry with them a unique perspective of the world and interact differently with those around them. Through a review of the literature and consensus by modified Delphi methodology of the Society for Academic Emergency Medicine Aging and Generational Issues Task Force, the authors have developed this two-part series to address generational issues present in academic emergency medicine (EM). Understanding generational characteristics and mitigating strategies can help address some common issues encountered in academic EM. Through recognition of the unique characteristics of each of the generations with respect to teaching and learning, mentoring, and technology, academicians have the opportunity to strategically optimize interactions with one another. © 2011 by the Society for Academic Emergency Medicine.

Towards a broader understanding of generational diversity at work : methodological and empirical contributions from a multi-cultural study

OpenAIRE

Gonçalves, João André Ferreira

2015-01-01

Tese de mestrado, Psicologia (Secção de Psicologia dos Recursos Humanos, do Trabalho e das Organizações), Universidade de Lisboa, Faculdade de Psicologia, 2015 Despite a disarray of popular literature concerning generational diversity in the workplace, the scientific research in this domain is still scarce and seeks stronger theoretical grounding. Regarding this problematic, the present work aims to contribute to a broader understanding of generational diversity in the workplace, by ...

Characteristics of healthcare wastes

International Nuclear Information System (INIS)

Diaz, L.F.; Eggerth, L.L.; Enkhtsetseg, Sh.; Savage, G.M.

2008-01-01

A comprehensive understanding of the quantities and characteristics of the material that needs to be managed is one of the most basic steps in the development of a plan for solid waste management. In this case, the material under consideration is the solid waste generated in healthcare facilities, also known as healthcare waste. Unfortunately, limited reliable information is available in the open literature on the quantities and characteristics of the various types of wastes that are generated in healthcare facilities. Thus, sound management of these wastes, particularly in developing countries, often is problematic. This article provides information on the quantities and properties of healthcare wastes in various types of facilities located in developing countries, as well as in some industrialized countries. Most of the information has been obtained from the open literature, although some information has been collected by the authors and from reports available to the authors. Only data collected within approximately the last 15 years and using prescribed methodologies are presented. The range of hospital waste generation (both infectious and mixed solid waste fractions) varies from 0.016 to 3.23 kg/bed-day. The relatively wide variation is due to the fact that some of the facilities surveyed in Ulaanbaatar include out-patient services and district health clinics; these facilities essentially provide very basic services and thus the quantities of waste generated are relatively small. On the other hand, the reported amount of infectious (clinical, yellow bag) waste varied from 0.01 to 0.65 kg/bed-day. The characteristics of the components of healthcare wastes, such as the bulk density and the calorific value, have substantial variability. This literature review and the associated attempt at a comparative analysis point to the need for worldwide consensus on the terms and characteristics that describe wastes from healthcare facilities. Such a consensus would greatly

Research on the operation characteristics of a free-piston linear generator: Numerical model and experimental results

International Nuclear Information System (INIS)

Guo, Chendong; Feng, Huihua; Jia, Boru; Zuo, Zhengxing; Guo, Yuyao; Roskilly, Tony

2017-01-01

Highlights: • The operation process of free-piston linear generator is investigated. • The larger the motor force at the starting process, the fewer circulations of the piston reciprocating to meet ignition condition. • The “gradually switching strategy” is the best strategy in the intermediate process. • During the generating process, engines indicated power is 2.9 kW with an efficiency of 37.3% under medium load. - Abstract: Free piston linear generator (FPLG) shows unique operation characteristics due to the elimination of crankshaft and connecting rod mechanism. This paper investigates its operation characteristics during each operating process based on the simulation and experiment results. During the starting process, the larger motor force during the starting process, the fewer times of reciprocating pistons which meet the condition of ignition. When the motor force reached 300 N, the prototype could adopt one-stroke starting strategy. During the intermediate process, it was found that the “gradually switching strategy” could help to achieve a smoother operation during the intermediate process. And the values of the operation parameters after the intermediate process were lower than those before the intermediate process. During the generating process, cycle-to-cycle variations were observed for piston TDC and in-cylinder gas pressure from the experimental results. According to the experimental results of the FPLG during the generating process, the calculated engine indicated power is 2.9 kW, and the corresponding indicated thermal efficiency is 37.3%. Additionally, based on the comparison of the FPLG performance, it is found that the parameters of the FPLG during the generating process are smaller than those when it was operated during the second stage of the starting process, while much higher than those during the first stage of the starting process.

Operational procedure for computer program for design point characteristics of a compressed-air generator with through-flow combustor for V/STOL applications

Science.gov (United States)

Krebs, R. P.

1971-01-01

The computer program described in this report calculates the design-point characteristics of a compressed-air generator for use in V/STOL applications such as systems with a tip-turbine-driven lift fan. The program computes the dimensions and mass, as well as the thermodynamic performance of a model air generator configuration which involves a straight through-flow combustor. Physical and thermodynamic characteristics of the air generator components are also given. The program was written in FORTRAN IV language. Provision has been made so that the program will accept input values in either SI units or U.S. customary units. Each air generator design-point calculation requires about 1.5 seconds of 7094 computer time for execution.

Characteristics of fluctuating pressure generated in BWR main steam lines

International Nuclear Information System (INIS)

Takahashi, Shiro; Okuyama, Keita; Tamura, Akinori

2009-01-01

The BWR-3 steam dryer in the Quad Cities Unit 2 Nuclear Power Plant was damaged by high cycle fatigue due to acoustic-induced vibration. The dryer failure was as attributed to flow-induced acoustic resonance at the stub pipes of safety relief valves (SRVs) in the main steam lines (MSLs). The acoustic resonance was considered to be generated by interaction between the sound field and an unstable shear layer across the closed side branches with SRV stub pipes. We have started a research program on BWR dryers to develop their loading evaluation methods. Moreover, it has been necessary to evaluate the dryer integrity of BWR-5 plants which are the main type of BWR in Japan. In the present study, we used 1/10-scale BWR tests and analyses to investigate the flow-induced acoustic resonance and acoustic characteristics in MSLs. The test apparatus consisted of a steam dryer, a steam dome and 4 MSLs with 20 SRV stub pipes. A finite element method (FEM) was applied for the calculation of three-dimensional wave equations in acoustic analysis. We demonstrated that remarkable fluctuating pressures occurred in high and low frequency regions. High frequency fluctuating pressures was generated by the flow-induced acoustic resonance in the SRV stub pipes. Low frequency fluctuating pressure was generated in an MSL with the dead leg. The frequency of the latter almost coincided with the natural frequency of the MSL with the dead leg. The amplitude of the fluctuating pressures in the multiple stub pipes became more intense because of interaction between them compared with that in the single stub pipe. Acoustic analysis results showed that the multiple stub pipes caused several natural frequencies in the vicinity of the natural frequency of the single stub pipe and several modes of the standing wave in the MSLs. (author)

Characteristics of a Portable Neutron Generator

International Nuclear Information System (INIS)

Jin, Jeong-Tae; Oh, Byung-Hoon; Chang, Dae-Sik; In, Sang-Yeol; Huh, Sung-Ryul; Hong, Kwang-Pyo

2015-01-01

Neutron generators can be excellent tools for materials analysis, explosive material detection, nuclear weapon detection, and high quality radiography. D + D : 3He + n (2.5 MeV) D + T : 4He + n (14 MeV) Recent commercial neutron generators, fast neutron yield from 10 7 to 10 11 n/s, are produced by several companies and research groups around the world. But limited life time, high price, and frequent troubles make it difficult to develop related application systems by domestic companies or research groups. To remove such problems, it is necessary to develop our own domestic neutron generators. In this presentation, the design and experimental results on the developed small neutron generator are summarized. Experiments on deuterium beam extraction and fast neutron measurement by injecting deuterium beams on a drive-in target are executed. The stable deuterium beam of the energy higher than 100 keV was achieved by introducing metal cover which reduces the effect of metal-vacuum-insulator triple junction. The neutron flux of 5 n/s is measured by RadEye GN gamma Neutron (Thermo scientific) detector with about 200 mm distance and insertion of 40 mm PE plate between neutron source and the detector. The precise detector calibration is not carried out yet, so more detailed experimental results will be summarized at the presentation

Characteristics of a Portable Neutron Generator

Energy Technology Data Exchange (ETDEWEB)

Jin, Jeong-Tae; Oh, Byung-Hoon; Chang, Dae-Sik; In, Sang-Yeol; Huh, Sung-Ryul; Hong, Kwang-Pyo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

Neutron generators can be excellent tools for materials analysis, explosive material detection, nuclear weapon detection, and high quality radiography. D + D : 3He + n (2.5 MeV) D + T : 4He + n (14 MeV) Recent commercial neutron generators, fast neutron yield from 10{sup 7} to 10{sup 11} n/s, are produced by several companies and research groups around the world. But limited life time, high price, and frequent troubles make it difficult to develop related application systems by domestic companies or research groups. To remove such problems, it is necessary to develop our own domestic neutron generators. In this presentation, the design and experimental results on the developed small neutron generator are summarized. Experiments on deuterium beam extraction and fast neutron measurement by injecting deuterium beams on a drive-in target are executed. The stable deuterium beam of the energy higher than 100 keV was achieved by introducing metal cover which reduces the effect of metal-vacuum-insulator triple junction. The neutron flux of 5 n/s is measured by RadEye GN gamma Neutron (Thermo scientific) detector with about 200 mm distance and insertion of 40 mm PE plate between neutron source and the detector. The precise detector calibration is not carried out yet, so more detailed experimental results will be summarized at the presentation.

Characteristics Associated with Persistence and Retention among First-Generation College Students Majoring in Science, Technology, Engineering, or Math

Science.gov (United States)

Burnett, Lorie Lasseter

Persistence and retention of college students is a great concern in American higher education. The dropout rate is even more apparent among first-generation college students, as well as those majoring in science, technology, engineering, and math (STEM). More students earning STEM degrees are needed to fill the many jobs that require the skills obtained while in college. More importantly, those students who are associated with a low-socioeconomic background may use a degree to overcome poverty. Although many studies have been conducted to determine the characteristics associated with student attrition among first-generation students or STEM majors, very little information exists in terms of persistence and retention among the combined groups. The current qualitative study identified some of the characteristics associated with persistence and retention among first-generation college students who are also STEM majors. Participants were juniors or seniors enrolled at a regional 4-year institution. Face-to-face interviews were conducted to allow participants to share their personal experiences as first-generation STEM majors who continue to persist and be retained by their institution. Tinto's Theory of Individual Departure (1987) was used as a framework for the investigation. This theory emphasizes personal and academic background, personal goals, disconnecting from one's own culture, and institutional integration as predictors of persistence. The findings of the investigation revealed that persisting first-generation STEM majors are often connected to family, but have been able to separate that connection with that of the institution. They also are goal-driven and highly motivated and have had varied pre-college academic experiences. These students are academically integrated and socially integrated in some ways, but less than their non-first-generation counterparts. They are overcoming obstacles that students from other backgrounds may not experience. They receive

Understanding Changes in Modeled Land Surface Characteristics Prior to Lightning-Initiated Holdover Fire Breakout

Science.gov (United States)

Schultz, Christopher J.; Case, Jonathan L.; Hain, Christopher R.; White, Kristopher; Wachter, J. Brent; Nauslar, Nicholas; MacNamara, Brittany

2018-01-01

Lightning initiated wildfires are only 16% of the total number of wildfires within the United States, but account for 56% of the acreage burned. One of the challenges with lightning-initiated wildfires is their ability to "holdover" which means smolder for up to 2+ weeks before breaking out into a full fledged fire. This work helps characterize the percentage of holdover events due to lightning, and helps quantify changes in the land surface characteristics to help understand trends in soil moisture and vegetation stress that potentially contribute to the fire breaking out into a full wildfire.

TRANSPORT CHARACTERISTICS OF SELECTED PWR LOCA GENERATED DEBRIS

International Nuclear Information System (INIS)

MAJI, A. K.; MARSHALL, B.

2000-01-01

In the unlikely event of a Loss of Coolant Accident (LOCA) in a pressurized water reactor (PWR), break jet impingement would dislodge thermal insulation FR-om nearby piping, as well as other materials within the containment, such as paint chips, concrete dust, and fire barrier materials. Steam/water flows induced by the break and by the containment sprays would transport debris to the containment floor. Subsequently, debris would likely transport to and accumulate on the suction sump screens of the emergency core cooling system (ECCS) pumps, thereby potentially degrading ECCS performance and possibly even failing the ECCS. In 1998, the U. S. Nuclear Regulatory Commission (NRC) initiated a generic study (Generic Safety Issue-191) to evaluate the potential for the accumulation of LOCA related debris on the PWR sump screen and the consequent loss of ECCS pump net positive suction head (NPSH). Los Alamos National Laboratory (LANL), supporting the resolution of GSI-191, was tasked with developing a method for estimating debris transport in PWR containments to estimate the quantity of debris that would accumulate on the sump screen for use in plant specific evaluations. The analytical method proposed by LANL, to predict debris transport within the water that would accumulate on the containment floor, is to use computational fluid dynamics (CFD) combined with experimental debris transport data to predict debris transport and accumulation on the screen. CFD simulations of actual plant containment designs would provide flow data for a postulated accident in that plant, e.g., three-dimensional patterns of flow velocities and flow turbulence. Small-scale experiments would determine parameters defining the debris transport characteristics for each type of debris. The containment floor transport methodology will merge debris transport characteristics with CFD results to provide a reasonable and conservative estimate of debris transport within the containment floor pool and

A Study on non-contact measurements of laser-generated lamb waves

International Nuclear Information System (INIS)

Jang, Tae Seong; Lee, Jung Ju; Lee, Seung Seok

2002-01-01

Generation and detection of Lamb waves offer an effective non-destructive testing technique that will detect defects quickly and reliably. Lamb waves are generated in a thin plate by Q-switched Nd:YAG pulsed laser. Symmetric and antisymmetric Lamb modes in low-frequency-thickness regime are excited by illuminating a thin plate with an array of laser-generated line sources. The propagation of laser-generated Lamb waves is detected by measuring the out-of-plane displacements in a non-contact manner using the fiber optic Sagnac interferometer and all commercial adaptive reference-beam interferometer. The characteristics of laser-generated Lamb wave due to its frequency are investigated. Fundamental understanding of laser-generated Lamb modes is presented.

ODG: Omics database generator - a tool for generating, querying, and analyzing multi-omics comparative databases to facilitate biological understanding.

Science.gov (United States)

Guhlin, Joseph; Silverstein, Kevin A T; Zhou, Peng; Tiffin, Peter; Young, Nevin D

2017-08-10

Rapid generation of omics data in recent years have resulted in vast amounts of disconnected datasets without systemic integration and knowledge building, while individual groups have made customized, annotated datasets available on the web with few ways to link them to in-lab datasets. With so many research groups generating their own data, the ability to relate it to the larger genomic and comparative genomic context is becoming increasingly crucial to make full use of the data. The Omics Database Generator (ODG) allows users to create customized databases that utilize published genomics data integrated with experimental data which can be queried using a flexible graph database. When provided with omics and experimental data, ODG will create a comparative, multi-dimensional graph database. ODG can import definitions and annotations from other sources such as InterProScan, the Gene Ontology, ENZYME, UniPathway, and others. This annotation data can be especially useful for studying new or understudied species for which transcripts have only been predicted, and rapidly give additional layers of annotation to predicted genes. In better studied species, ODG can perform syntenic annotation translations or rapidly identify characteristics of a set of genes or nucleotide locations, such as hits from an association study. ODG provides a web-based user-interface for configuring the data import and for querying the database. Queries can also be run from the command-line and the database can be queried directly through programming language hooks available for most languages. ODG supports most common genomic formats as well as generic, easy to use tab-separated value format for user-provided annotations. ODG is a user-friendly database generation and query tool that adapts to the supplied data to produce a comparative genomic database or multi-layered annotation database. ODG provides rapid comparative genomic annotation and is therefore particularly useful for non-model or

Measurement and analysis of time-domain characteristics of corona-generated radio interference from a single positive corona source

Science.gov (United States)

Li, Xuebao; Li, Dayong; Chen, Bo; Cui, Xiang; Lu, Tiebing; Li, Yinfei

2018-04-01

The corona-generated electromagnetic interference commonly known as radio interference (RI) has become a limiting factor for the design of high voltage direct current transmission lines. In this paper, a time-domain measurement system is developed to measure the time-domain characteristics of corona-generated RI from a single corona source under a positive corona source. In the experiments, the corona current pulses are synchronously measured through coupling capacitors. The one-to-one relationship between the corona current pulse and measured RI voltage pulse is observed. The statistical characteristics of pulse parameters are analyzed, and the correlations between the corona current pulse and RI voltage pulse in the time-domain and frequency-domain are analyzed. Depending on the measured corona current pulses, the time-domain waveform of corona-generated RI is calculated on the basis of the propagation model of corona current on the conductor, the dipolar model for electric field calculation, and the antenna model for inducing voltage calculation. The well matched results between measured and simulated waveforms of RI voltage can show the validity of the measurement and calculation method presented in this paper, which also further show the close correlation between corona current and corona-generated RI.

Determination of PV Generator I-V/P-V Characteristic Curves Using a DC-DC Converter Controlled by a Virtual Instrument

Directory of Open Access Journals (Sweden)

E. Durán

2012-01-01

Full Text Available A versatile measurement system for systematic testing and measurement of the evolution of the I-V characteristic curves of photovoltaic panels or arrays (PV generators is proposed in this paper. The measurement system uses a circuit solution based on DC-DC converters that involves several advantages relative to traditional methods: simple structure, scalability, fast response, and low cost. The measurement of the desired characteristics of PV generators includes high speed of response and high fidelity. The prototype system built is governed by a microcontroller, and experimental results prove the proposed measurement system useful. A virtual instrument (VI was developed for full system control from a computer. The developed system enables monitoring the suitable operation of a PV generator in real time, since it allows comparing its actual curves with those provided by the manufacturer.

Understanding the Characteristics of the Sexual Harasser.

Science.gov (United States)

Sundt, Melora

1996-01-01

Information on characteristics of harassers can help policymakers and educators develop more effective prevention programs. Results of a survey of 336 men and 333 women are presented in terms of institutional size, satisfaction with institutional response, views on the acceptability of harassment, beliefs related to harassment, and types of…

Vulnerability-specific stress generation: An examination of negative cognitive and interpersonal styles

OpenAIRE

Liu, Richard T.; Alloy, Lauren B.; Mastin, Becky M.; Choi, Jimmy Y.; Boland, Elaine M.; Jenkins, Abby L.

2014-01-01

Although there is substantial evidence documenting the stress generation effect in depression (i.e., the tendency for depression-prone individuals to experience higher rates of life stress to which they contribute), additional research is required to advance current understanding of the specific types of dependent stress (i.e., events influenced by characteristics and attendant behaviors of the individual) relevant to this effect. The present study tested an extension of the stress generation...

Challenges and Difficulties to Teaching Engineering to Generation Z: a case research

Directory of Open Access Journals (Sweden)

Suamit Correia Barreiro

2017-08-01

Full Text Available Many people from generation Z are at the beginning of their academic activities. This generation has peculiar characteristics that might be a challenge in the labor market. Thus, instructors have a great role in their preparation. However, professors might face difficulties dealing with their specific characteristics. The research aims to carry out a general survey to enable an understanding of the greater challenges and difficulties in teaching the subject of engineering to the students of Generation Z. The research method used was a case study at a University with 20 instructors from the Faculty of Engineering. The analysis revealed a great challenge in relating theoretical concepts with practical concepts. The research also showed a probable tendency of using more exhibition methods, and the low knowledge about generation Z by most instructors. This study seeks to contribute to the teaching-learning process of engineering.

Understanding I/O workload characteristics of a Peta-scale storage system

Energy Technology Data Exchange (ETDEWEB)

Kim, Youngjae [ORNL; Gunasekaran, Raghul [ORNL

2015-01-01

Understanding workload characteristics is critical for optimizing and improving the performance of current systems and software, and architecting new storage systems based on observed workload patterns. In this paper, we characterize the I/O workloads of scientific applications of one of the world s fastest high performance computing (HPC) storage cluster, Spider, at the Oak Ridge Leadership Computing Facility (OLCF). OLCF flagship petascale simulation platform, Titan, and other large HPC clusters, in total over 250 thousands compute cores, depend on Spider for their I/O needs. We characterize the system utilization, the demands of reads and writes, idle time, storage space utilization, and the distribution of read requests to write requests for the Peta-scale Storage Systems. From this study, we develop synthesized workloads, and we show that the read and write I/O bandwidth usage as well as the inter-arrival time of requests can be modeled as a Pareto distribution. We also study the I/O load imbalance problems using I/O performance data collected from the Spider storage system.

Alternatives to the grid : distributed generation

Energy Technology Data Exchange (ETDEWEB)

Kline, R.H. [Mercury Electric Corp., Calgary, AB (Canada)

2001-07-01

This presentation highlighted the merits of distributed generation. The author began by discussing energy drivers, touching on issues such as reliability, power quality, and the confusion resulting from the energy market, and energy costs. It was pointed out that the deregulation of the electricity market in Alberta was implemented on January 1, 1996 which has resulted in steady price increases ever since. A review of the options available to the customer begin by understanding baseload and peaking. The options then available are buying from the utility, buying through a reputable marketer, buying direct from a large scale independent power producer, on-site generation, and finally, distributed generation. The emphasis was placed on distributed generation defined as small scale on-site power generation and offers advantages such as the reduction/elimination of peak strain on grid, and offset/defer utility capital costs, therefore reducing total energy costs. Regulatory changes are making it easier than ever before to make the transition to distributed generation. The author briefly reviewed the advantages of microturbines then presented the Honeywell Parallon 75 TurboGenerator{sup TM}, reviewing its characteristics, operating modes and commercial applications. Examples were provided of successful microturbines installations throughout the country. figs.

Analysis of Generator Oscillation Characteristics Based on Multiple Synchronized Phasor Measurements

Science.gov (United States)

Hashiguchi, Takuhei; Yoshimoto, Masamichi; Mitani, Yasunori; Saeki, Osamu; Tsuji, Kiichiro

In recent years, there has been considerable interest in the on-line measurement, such as observation of power system dynamics and evaluation of machine parameters. On-line methods are particularly attractive since the machine’s service need not be interrupted and parameter estimation is performed by processing measurements obtained during the normal operation of the machine. Authors placed PMU (Phasor Measurement Unit) connected to 100V outlets in some Universities in the 60Hz power system and examine oscillation characteristics in power system. PMU is synchronized based on the global positioning system (GPS) and measured data are transmitted via Internet. This paper describes an application of PMU for generator oscillation analysis. The purpose of this paper is to show methods for processing phase difference and to estimate damping coeffcient and natural angular frequency from phase difference at steady state.

Rewired: Understanding the iGeneration and the Way They Learn

Science.gov (United States)

Rosen, Larry D.

2010-01-01

The iGeneration is radically different from any previous generation of students and a variety of existing technologies can be used to engage and excite them in the learning process. The iGeneration is a creative, multimedia generation. They think of the world as a canvas to paint with words, sights, sounds, video, music, web pages, and anything…

Using the living laboratory framework as a basis for understanding next-generation analyst work

Science.gov (United States)

McNeese, Michael D.; Mancuso, Vincent; McNeese, Nathan; Endsley, Tristan; Forster, Pete

2013-05-01

The preparation of next generation analyst work requires alternative levels of understanding and new methodological departures from the way current work transpires. Current work practices typically do not provide a comprehensive approach that emphasizes the role of and interplay between (a) cognition, (b) emergent activities in a shared situated context, and (c) collaborative teamwork. In turn, effective and efficient problem solving fails to take place, and practice is often composed of piecemeal, techno-centric tools that isolate analysts by providing rigid, limited levels of understanding of situation awareness. This coupled with the fact that many analyst activities are classified produces a challenging situation for researching such phenomena and designing and evaluating systems to support analyst cognition and teamwork. Through our work with cyber, image, and intelligence analysts we have realized that there is more required of researchers to study human-centered designs to provide for analyst's needs in a timely fashion. This paper identifies and describes how The Living Laboratory Framework can be utilized as a means to develop a comprehensive, human-centric, and problem-focused approach to next generation analyst work, design, and training. We explain how the framework is utilized for specific cases in various applied settings (e.g., crisis management analysis, image analysis, and cyber analysis) to demonstrate its value and power in addressing an area of utmost importance to our national security. Attributes of analyst work settings are delineated to suggest potential design affordances that could help improve cognitive activities and awareness. Finally, the paper puts forth a research agenda for the use of the framework for future work that will move the analyst profession in a viable manner to address the concerns identified.

Multiple Sclerosis in the Contemporary Age: Understanding the Millennial Patient with Multiple Sclerosis to Create Next-Generation Care.

Science.gov (United States)

Hansen, Madison R; Okuda, Darin T

2018-02-01

The average age of onset of multiple sclerosis (MS) is between 20 and 40 years of age. Therefore, most new patients diagnosed with MS within the next 10 to 15 years will be from the millennial generation, representing those born between 1982 and 2000. Certain preferences and trends of this contemporary generation will present new challenges to the MS physician and effective MS care. By first understanding these challenges, relevant and successful solutions can be created to craft a system of care that best benefits the millennial patient with MS. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of Attitudes between Generation X and Baby Boomer Veterinary Faculty and Residents

OpenAIRE

Freeman, Lisa M.; Trower, Cathy A.; Tan, Rachael J.B.; Terkla, Dawn Geronimo

2009-01-01

Understanding the characteristics and preferences of the different generations in the veterinary workforce is important if we are to help optimize current and future veterinary schools and teaching hospitals. The purpose of this study was to compare the attitudes of different generations of veterinary faculty and those of faculty and house officers. A survey administered to faculty and house officers asked respondents to identify their level of agreement with a series of statements addressing...

Amplitude-temporal characteristics of a supershort avalanche electron beam generated during subnanosecond breakdown in air and nitrogen

Science.gov (United States)

Tarasenko, V. F.; Baksht, E. Kh.; Beloplotov, D. V.; Burachenko, A. G.; Lomaev, M. I.

2016-04-01

The amplitude-temporal characteristics of a supershort avalanche electron beam (SAEB) with an amplitude of up to 100 A, as well as of the breakdown voltage and discharge current, are studied experimentally with a picosecond time resolution. The waveforms of discharge and SAEB currents are synchronized with those of the voltage pulses. It is shown that the amplitude-temporal characteristics of the SAEB depend on the gap length and the designs of the gas diode and cathode. The mechanism for the generation of runaway electron beams in atmospheric-pressure gases is analyzed on the basis of the obtained experimental data.

Amplitude−temporal characteristics of a supershort avalanche electron beam generated during subnanosecond breakdown in air and nitrogen

Energy Technology Data Exchange (ETDEWEB)

Tarasenko, V. F., E-mail: vft@loi.hcei.tsc.ru; Baksht, E. Kh.; Beloplotov, D. V.; Burachenko, A. G.; Lomaev, M. I. [Siberian Branch, Russian Academy of Sciences, Institute of High Current Electronics (Russian Federation)

2016-04-15

The amplitude−temporal characteristics of a supershort avalanche electron beam (SAEB) with an amplitude of up to 100 A, as well as of the breakdown voltage and discharge current, are studied experimentally with a picosecond time resolution. The waveforms of discharge and SAEB currents are synchronized with those of the voltage pulses. It is shown that the amplitude−temporal characteristics of the SAEB depend on the gap length and the designs of the gas diode and cathode. The mechanism for the generation of runaway electron beams in atmospheric-pressure gases is analyzed on the basis of the obtained experimental data.

Understanding the biology of urothelial cancer metastasis

Directory of Open Access Journals (Sweden)

Takashi Kobayashi

2016-10-01

Full Text Available Management of unresectable urothelial cancer (UC has been a clinical challenge for decades. While drug resistance is a key issue, precise understanding of biology of UC metastasis is another challenge for the improvement of treatment outcome of UC patients. Introduction of the cell biology concepts including epithelial-mesenchymal transition (EMT and cancer stemness seems to explain UC metastasis. Molecular genetics based on gene expression profiling, next generation sequencing, and explosion of non-coding RNA world has opened the door to intrinsic molecular subtyping of UC. Next steps include, based on the recently accumulated understanding, the establishment of novel disease models representing UC metastasis in various experimental platforms, particularly in vivo animal systems. Indeed, novel knowledge molecular genetics has not been fully linked to the modeling of UC metastasis. Further understanding of bladder carcinogenesis is needed particularly with regard to cell of origin related to tumor characteristics including driver gene alterations, pathological differentiations, and metastatic ability. Then we will be able to establish better disease models, which will consequently lead us to further understanding of biology and eventually the development of novel therapeutic strategies for UC metastasis.

Microstructure evolution characteristics induced by oxygen vacancy generation in anatase TiO2 based resistive switching devices

Science.gov (United States)

Liu, Chen; Gao, Bin; Huang, Peng; Kang, Jinfeng

2017-03-01

In this work, first principle calculations are employed to study the microstructure characteristics of the anatase TiO2 resistive switching material associated with the generation of oxygen vacancy (V o) based nanofilaments during the switching process. The calculations indicate that both the magnéli phase Ti4O7 and V o-defect phase of anatase TiO2 may be formed with the generation of oxygen vacancies during the forming and SET processes. Based on the calculations, a new physical insight is proposed to clarify the microstructure evolution characteristics of the anatase TiO2 resistive switching material and the correlation with resistive switching behaviors. During the forming or SET process, the anatase TiO2 is first excited to a transition state with the generation of oxygen vacancies, then fully relaxes to a stable V o-defect state. This V o-defect state may either recover to the original state with the recombination of the oxygen vacancies, which causes the reversible resistive switching behavior, or further transform to a much more stable state—the magnéli phase Ti4O7, through a phase transition process with the generation of many more oxygen vacancies. The phase transition from V o- defective anatase phase to magnéli phase Ti4O7 causes the failure of the resistive switching due to the significantly reduced possibility of the reversible phase transition from the magnéli phase to the anatase phase, compared with the possibility of the recombination from the V o-defective anatase.

Understanding Flash Flood Generation in the Arid Region of the Dead Sea

Science.gov (United States)

Merz, R.; Hennig, H.; Rödiger, T.; Laronne, J. B.

2017-12-01

The arid region of the Dead Sea is prone by flash floods. Such flash floods in (semi-) arid regions are impressive. Generated within minutes, the peak unit discharge can be as high as 25 m³/s km². Floods are the main mechanism supplying water to alluvial aquifers, forming fluvial landscapes including canyons and often causing damage to humans, infrastructure, industry and tourism. Existing hydrological models in this region focus on peak discharges. However, these models are often based on simplified concepts and/or on concepts which were developed for humid regions. To more closely relate such models to local conditions, processes within catchments where floods occur require consideration. Therefore, a measurement network of rain gauges and level loggers to monitor runoff was installed in the beginning of the 2015/16 hydrological season in the tributaries of Wadi Arugot. The Arugot catchment is one of the largest ephemeral Wadis draining to the western shoreline of the Dead Sea at 450 m bsl. Due to the high gradient in elevation, the climate within the basin ranges from semiarid in the Judean Mountains, to hyper-arid near the Dead Sea with respective mean annual rainfall of 650 and 50 mm. The installed rain gauge network in the mountains is more dense compared to the Dead Sea area. Arid to semiarid catchments have different runoff generation processes compared to humid regions due local storm rainfall, low density of vegetation cover as well as patchy and shallow soil. These characteristics limit the contribution of groundwater flow, saturated overland flow and shallow subsurface flow, and therefore Hortonian overland flow is the most important contributor to overland flow. First analyses of the runoff data have shown that the storage capacity in the mountain area is lower compared to the more arid region. This is an evidence of high transmission losses in the coarse gravel wadi bed, therefore having a high permeability. The rain event duration and the amount of

Numerical Study on the Helium Flow Characteristics for Steam Generator Subsystem of HTR

International Nuclear Information System (INIS)

Ha, Jung Hoon; Ham, Jin Ki; Ki, Min-Hwan; Lee, Won Jae

2014-01-01

The High Temperature Reactor (HTR), one of the 4th generation reactors, utilizes helium as the primary coolant. A Steam Generator Subsystem (SGS) is installed to transfer heat from the primary coolant to feed water and subsequently produce steam so that it supplies electricity as well as process heat over a wide range. The SGS is composed of a helical heat exchanger, shrouds directing the flow of the shell side helium and support systems, which are located within the steam generator vessel. In this study, helium flow characteristics in the SGS were investigated at various operating conditions using Computational Fluid Dynamics (CFD). A full-scale 3-D model of the SGS was developed and the reynolds stress model with standard wall treatment was used as a turbulence model. The CFD result was compared to that of the concept design of the steam cycle modular helium reactor for the design verification of the SGS. From the CFD analysis, it was found that the primary coolant flow had non-uniform distribution while it passed the inlet in the helical heat exchanger. In order to make the uniform primary coolant flow uniform, a special type of screen was suggested in front of the helical heat exchanger. As a result, the overall design adequacy of the SGS has been evaluated. (author)

Transient characteristics of parallel running of the 20kVA superconducting synchronous generator and a conventional one

International Nuclear Information System (INIS)

Nitta, T.; Okada, T.

1989-01-01

This paper describes electrical transient characteristics of parallel running of the 20kVA superconducting synchronous generator and a conventional one. In the experimental power system, the superconducting generator is connected through reactors (artificial transmission lines) to a regional power system (infinite bus) and the conventional generator (20kVA) is connected to the terminal of the superconducting generator. Several tests were performed in order to consider the transient behavior of superconducting generator (SCG) in the power system. The items of the tests are synchronous closing test, loss of synchronism test and disconnecting and reclosing test. From the experimental results, it can be said that by installing SCG in power systems, voltage stability and power system stability can be improved in transient states as well as in steady states and the variation of armature current of SCG during a transient period is extremely larger than that of the conventional one. The transient analysis by a computer simulation was also carried out for the experiments. The simulation results are in good agreement with the experimental ones

Understanding the anaerobic biodegradability of food waste: Relationship between the typological, biochemical and microbial characteristics.

Science.gov (United States)

Fisgativa, Henry; Tremier, Anne; Le Roux, Sophie; Bureau, Chrystelle; Dabert, Patrick

2017-03-01

In this study, an extensive characterisation of food waste (FW) was performed with the aim of studying the relation between FW characteristics and FW treatability through an anaerobic digestion process. In addition to the typological composition (paper, meat, fruits, vegetables contents, etc) and the physicochemical characteristics, this study provides an original characterisation of microbial populations present in FW. These intrinsic populations can actively participate to aerobic and anaerobic degradation with the presence of Proteobacteria and Firmicutes species for the bacteria and of Ascomycota phylum for the fungi. However, the characterisation of FW bacterial and fungi community shows to be a challenge because of the biases generated by the non-microbial DNA coming from plant and by the presence of mushrooms in the food. In terms of relations, it was demonstrated that some FW characteristics as the density, the volatile solids and the fibres content vary as a function of the typological composition. No direct relationship was demonstrated between the typological composition and the anaerobic biodegradability. However, the Pearson's matrix results reveal that the anaerobic biodegradation potential of FW was highly related to the total chemical oxygen demand (tCOD), the total solid content (TS), the high weight organic matter molecules soluble in water (SOL W >1.5 kDa) and the C/N ratio content. These relations may help predicting FW behaviour through anaerobic digestion process. Finally, this study also showed that the storage of FW before collection, that could induce pre-biodegradation, seems to impact several biochemical characteristics and could improve the biodegradability of FW. Copyright © 2016 Elsevier Ltd. All rights reserved.

The value of a combined word recognition and knowledge measure to understand characteristics of our patients' oral health literacy.

Science.gov (United States)

Atchison, Kathryn A; Macek, Mark D; Markovic, Daniela

2017-08-01

The objective of the analysis was to examine the association between sociodemographic and dental understanding and utilization characteristics and lower oral health literacy (HL) and knowledge. The cross-sectional Multicenter Oral Health Literacy Research Study (MOHLRS) recruited and interviewed 923 English-speaking, initial care-seeking adults. The questionnaire included participant sociodemographic characteristics, measures of the participant's understanding and utilization of dentistry, and two oral HL measures, the Rapid Estimate of Adult Literacy in Medicine and Dentistry (REALM-D) and the Comprehensive Measure of Oral Health Knowledge (CMOHK), which were combined into a new composite HL and knowledge measure, the MOHLR-K. In adjusted multivariable analysis, persons who reported more understanding of dentist instructions had higher mean scores for all HL measures. Subjects reporting the highest level of understanding had greater scores by an average of 1.6 points for the MOHLR-K (95% CI: 0.85-2.40, Pdental understanding and utilization factors. Persons who reported history of tooth decay had higher MOHLR-K scores by an average of about 0.77 points (95% CI: 0.49-1.04, Ptooth decay history after controlling for the other factors. Persons who had support all of the time for travel to the dentist had higher scores by an average of about 0.5 points for the MOHLR-K (95% CI: 0.04-0.96, P=.03) and about 0.89 points for the REALMD-20 (95% CI: 0-1.79, P=.05) as compared to subjects with no support after controlling for other factors. Report of periodontal history, financial challenges to delay a dental visit and dental utilization were not significantly associated with any of the HL measures once the other factors were adjusted for in the model. The analysis confirmed that pronunciation of medical and dental terms may not fully reflect comprehension and revealed that understanding both patients' sociodemographic and dental understanding and utilization factors, such as

Effectiveness of micronic aerosol generators and their aerosol characteristics

International Nuclear Information System (INIS)

Chinet, T.; Collignon, M.-A.; Dusser, D.; Barritault, L.; Huchon, G.J.

1986-01-01

We assessed the effectiveness of various aerosol-generating systems. Taplin's settling method and Venticis generators has a lower efficiency (37.3 +- 3.8% and 51.8 +- 9.6%, respectively) than the Syntevent (88.8 +- 6.9%, p<0.001), Cadema (89.8 +- 9.9%, p<0.001) and Mefar (85.3 +- 19.4%, p<0.001) generators. The Mass Median Aerodynamic Diameter of the particles produced by the Mefar nebulizer (2.05 +- 0.27 μm) was larger than that of any other generators (p<0.001). The Syntevent (0.54 +- 0.09 μm) generator produced smaller particles than the Mefar, Taplin (0.89 +- 0.10 μm, p<0.01) and Venticis (0.79 +- 0.06 μm, p<0.02) generators. Particles produced by the Cadema system (0.69 +- 0.06 μm) were smaller than those generated by the Taplin system(p<0.05). We conclude: 1) that the Syntevent, Mefar and Cadema aerosol generators are more efficient than the others, and 2) that all the generators tested except the Mefar may be used for studies that depend on the peripheral deposition of small particles within the lungs. (author)

Comparing millennial and generation X medical students at one medical school.

Science.gov (United States)

Borges, Nicole J; Manuel, R Stephen; Elam, Carol L; Jones, Bonnie J

2006-06-01

Two main generational cohorts comprising students enrolled in medical schools today are Generation Xers (born 1965-1980) and Millennial students (born 1981-1999). A subset is Cuspars (born 1975-1980), who share traits with both generations. Population theorists ascribe different personal characteristics, attitudes, and preferences to each group. The authors examined whether selected characteristics describing Generation X and Millennial students were quantifiable using a personality measure. Differences among Generation X, Millennial, and Cuspar medical students were investigated. Eight hundred and nine medical students (399 females and 410 males) who matriculated between 1989-94 and 2001-04 at the Northeastern Ohio Universities College of Medicine completed the 16 Personality Factor Questionnaire (16PF). Differences in responses to the 16PF among the three generations were analyzed using multivariate analysis of variance (MANOVA). Analyses showed significant differences for Generation X versus Millennial students on 10 of the 16 personality factors. Millennial students scored significantly higher than Generation X students on factors including Rule-Consciousness, Emotional Stability, and Perfectionism; Generation X students scored higher than Millennials on Self-Reliance. Millennials also were significantly different from Generation Xers on several other factors. Significant differences were noted among Cuspars, Generation Xers, and Millennials. The 16PF is a useful tool to examine differences among these groups and to help understand the factors that constitute their personalities. Given differences among the generational groups, the authors forecast possible educational implications for medical school academic affairs and student services, and suggest areas for future research.

Towards a better understanding of flood generation and surface water inundation mechanisms using NASA remote sensing data products

Science.gov (United States)

Lucey, J.; Reager, J. T., II; Lopez, S. R.

2017-12-01

Floods annually cause several weather-related fatalities and financial losses. According to NOAA and FEMA, there were 43 deaths and 18 billion dollars paid out in flood insurance policies during 2005. The goal of this work is to improve flood prediction and flood risk assessment by creating a general model of predictability of extreme runoff generation using various NASA products. Using satellite-based flood inundation observations, we can relate surface water formation processes to changes in other hydrological variables, such as precipitation, storage and soil moisture, and understand how runoff generation response to these forcings is modulated by local topography and land cover. Since it is known that a flood event would cause an abnormal increase in surface water, we examine these underlying physical relationships in comparison with the Dartmouth Flood Observatory archive of historic flood events globally. Using ground water storage observations (GRACE), precipitation (TRMM or GPCP), land use (MODIS), elevation (SRTM) and surface inundation levels (SWAMPS), an assessment of geological and climate conditions can be performed for any location around the world. This project utilizes multiple linear regression analysis evaluating the relationship between surface water inundation, total water storage anomalies and precipitation values, grouped by average slope or land use, to determine their statistical relationships and influences on inundation data. This research demonstrates the potential benefits of using global data products for early flood prediction and will improve our understanding of runoff generation processes.

Can I relate? A review and guide for nurse managers in leading generations.

Science.gov (United States)

Christensen, Scott S; Wilson, Barbara L; Edelman, Linda S

2018-01-30

The purpose of this review is to help the nurse leader develop an understanding of the five generations currently in the health care workforce by providing defining characteristics, general behaviours, and strategies for the nurse manager to employ for each generational cohort. Generations are groups of people born during the same 15-20 year time period who share similar experiences before adulthood, which shape long-term behaviours. Key descriptors and characteristics are provided. The current generational cohorts in the health care workforce are Traditionalists (born between 1922 and 1945), baby boomers (born between 1946 and 1964), Generation X (born between 1965 and 1979), millennials (born between 1980 and 1995), and Generation Z (born after 1995). Health care teams often comprise members of three or more generations. Intergenerational differences in team members can result in challenges; however, different perspectives provided by multiple generations can be used advantageously to strengthen the team's efficiency and outcomes. There are strengths in each generation. Key differences can be harnessed to build stronger teams through comprehensive communication strategies, customized reward systems, and workplace flexibility. Examples are provided for each area. Managers can use intergenerational differences to create a rich environment that bridges generational differences and fosters workforce cohesion. © 2018 John Wiley & Sons Ltd.

Ongoing child welfare services: Understanding the relationship of worker and organizational characteristics to service provision.

Science.gov (United States)

Lwin, Kristen; Fluke, John; Trocmé, Nico; Fallon, Barbara; Mishna, Faye

2018-06-01

Ongoing child welfare services are put in place after completion of the initial maltreatment investigation when there is a perceived need to mitigate the risk of future harm. The knowledge of how clinical, worker, and organizational characteristics interact with this decision to provide ongoing child welfare services is not well integrated in the research literature. Using secondary data from the Canadian Incidence Study of Reported Child Abuse and Neglect-2008, this study's primary objective is to understand the relationship of clinical, worker, and organizational characteristics to the decision to transfer a case to ongoing child welfare services and their relative contribution to the transfer decision in Canada. Findings indicate that several clinical level variables are associated with families receiving ongoing services. Additionally, organizational factors, such as type of services offered by the organization and the number of employee support programs available to workers, significantly predicted the decision to transfer a case to ongoing services. While no worker factors, such as education, amount of training, experience, or caseload, were associated with ongoing service receipt, the intraclass correlation coefficient of the final three-level parsimonious model indicated substantial clustering at the worker level. Results indicate that Canadian child welfare workers make decisions differently based on factors not available in the current study and that what would be deemed as important worker characteristics do not necessarily predict this outcome. Findings and implications for future research are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electrical and optical characteristics of dielectric-barrier discharge driven by high voltage nanosecond generator

International Nuclear Information System (INIS)

Ahmadeev, V.V.; Kost'yuchenko, S.V.; Kudryavtsev, N.N.; Kurkin, G.A.; Vasilyak, L.M.

1998-01-01

Electrical and optical characteristics of the dielectric-barrier discharge in the pressure range of 10-400 Torr were investigated experimentally, particular attention being paid to the discharge homogeneity and to the energy dissipation in the discharge volume. The discharge was driven by a high-voltage pulse generator producing nanosecond high-voltage pulses with an amplitude of 20-30 kV. Air, nitrogen, and helium were used as working gases. The discharge was found to be homogeneous within a wide range of gas pressure. A power density of up to 250 mW/cm 3 has been achieved. (J.U.)

The Characteristics of User-Generated Passwords

Science.gov (United States)

1990-03-01

electronic keys), user interface tokens (pocket devices that can generate one-time passwords) and fixed password devices ( plastic cards that contain...APPENDIX B-7 DIFFREM DIFFICULTY REMfEIBERING by PASSCHAR PASSORD CARACTERISTICS PASSCHAR Pate I of 1 Count 1 Row Pet IALPHAVET NUMERIC ALPHANUM ASCII Cal Pet

Progress toward understanding the contribution of alkali generation in dental biofilms to inhibition of dental caries

Science.gov (United States)

Liu, Ya-Ling; Nascimento, Marcelle; Burne, Robert A

2012-01-01

Alkali production by oral bacteria is believed to have a major impact on oral microbial ecology and to be inibitory to the initiation and progression of dental caries. A substantial body of evidence is beginning to accumulate that indicates the modulation of the alkalinogenic potential of dental biofilms may be a promising strategy for caries control. This brief review highlights recent progress toward understanding molecular genetic and physiologic aspects of important alkali-generating pathways in oral bacteria, and the role of alkali production in the ecology of dental biofilms in health and disease. PMID:22996271

Solar photovoltaic power generation system and understanding of green energy

International Nuclear Information System (INIS)

Yoo, Chun Sik

2004-03-01

This book introduces sunlight generation system and green energy, which includes new and renewable energy such as photovoltaic power generation, solar thermal, wind power, bio energy, waste energy, geothermal energy, ocean energy and fuel cell photovoltaic industry like summary, technology trend, market trend, development strategy of the industry in Korea, and other countries, design of photovoltaic power generation system supporting policy and related business of new and renewable energy.

Understanding Business Analytics

Science.gov (United States)

2015-01-05

analytics have been used in organizations for a variety of reasons for quite some time; ranging from the simple (generating and understanding business analytics...process. understanding business analytics 3 How well these two components are orchestrated will determine the level of success an organization has in

Analysis of characteristic aroma of fungal fermented Fuzhuan brick-tea by gas chromatography/mass spectrophotometry

NARCIS (Netherlands)

Xu, X.Q.; Mo, H.Z.; Yan, M.C.; Yang Zhu, Yang

2007-01-01

Fuzhuan brick-tea is a popular fermented Chinese dark tea because of its typical fungal aroma. Fungal growth during the production process is the key step in achieving the unique colour, aroma and taste of Fuzhuan brick-tea. To further understand the generation of the characteristic aroma, changes

Evaluating a Bilingual Text-Mining System with a Taxonomy of Key Words and Hierarchical Visualization for Understanding Learner-Generated Text

Science.gov (United States)

Kong, Siu Cheung; Li, Ping; Song, Yanjie

2018-01-01

This study evaluated a bilingual text-mining system, which incorporated a bilingual taxonomy of key words and provided hierarchical visualization, for understanding learner-generated text in the learning management systems through automatic identification and counting of matching key words. A class of 27 in-service teachers studied a course…

Towards an Explanation Generation System for Robots: Analysis and Recommendations

Directory of Open Access Journals (Sweden)

Ben Meadows

2016-10-01

Full Text Available A fundamental challenge in robotics is to reason with incomplete domain knowledge to explain unexpected observations and partial descriptions extracted from sensor observations. Existing explanation generation systems draw on ideas that can be mapped to a multidimensional space of system characteristics, defined by distinctions, such as how they represent knowledge and if and how they reason with heuristic guidance. Instances in this multidimensional space corresponding to existing systems do not support all of the desired explanation generation capabilities for robots. We seek to address this limitation by thoroughly understanding the range of explanation generation capabilities and the interplay between the distinctions that characterize them. Towards this objective, this paper first specifies three fundamental distinctions that can be used to characterize many existing explanation generation systems. We explore and understand the effects of these distinctions by comparing the capabilities of two systems that differ substantially along these axes, using execution scenarios involving a robot waiter assisting in seating people and delivering orders in a restaurant. The second part of the paper uses this study to argue that the desired explanation generation capabilities corresponding to these three distinctions can mostly be achieved by exploiting the complementary strengths of the two systems that were explored. This is followed by a discussion of the capabilities related to other major distinctions to provide detailed recommendations for developing an explanation generation system for robots.

Characteristics of semiconductor bridge (SCB) plasma generated in a micro-electro-mechanical system (MEMS)

International Nuclear Information System (INIS)

Kim, Jong-Uk; Park, Chong-Ook; Park, Myung-Il; Kim, Sun-Hwan; Lee, Jung-Bok

2002-01-01

Plasma ignition method has been applied in various fields particularly to the rocket propulsion, pyrotechnics, explosives, and to the automotive air-bag system. Ignition method for those applications should be safe and also operate reliably in hostile environments such as; electromagnetic noise, drift voltage, electrostatic background and so on. In the present Letter, a semiconductor bridge (SCB) plasma ignition device was fabricated and its plasma characteristics including the propagation speed of the plasma, plasma size, and plasma temperature were investigated with the aid of the visualization of micro scale plasma (i.e., ≤350 μm), which generated from a micro-electro-mechanical poly-silicon semiconductor bridge (SCB)

Further understanding of PbWO4 Scintillator characteristics and their optimisation. LUMEN activity in 1998

CERN Document Server

Baccaro, Stefania; Borgia, Bruno; Cecilia, Angelica; Dafinei, Ioan; Diemoz, Marcella; Fabeni, P; Festinesi, Armando; Longo, Egidio; Martini, M; Meinardi, F; Mihoková, E; Montecchi, Marco; Nikl, M; Pazzi, G P; Rosa, J; Sulc, Miroslav

2000-01-01

The aim of LUMEN collaboration was the investigation on single crystals of PbWO4 ( PWO): the results performed up to now provide the evidence of the possibility to optimise the optical properties of an intrinsic scintillator such as PWO. The control of essential requirements in the crystal preparation ( raw material purity, growing methods and post-growth annealing) as well as the introduction of selected dopants at suitable concentrations ( particularly trivalent and pentavalent ions) were found to be very successful in lowering the concentration of point defects in the lattice which strongly affect scintillation properties and radiation hardness. The systematic investigation effort to better understand the scintillation characteristics and to improve the quality of PWO crystals is due to their use for the CMS electromagnetic calorimeter.

Generation of soluble microbial products by bio-activated carbon filter during drinking water advanced treatment and its influence on spectral characteristics

Energy Technology Data Exchange (ETDEWEB)

Shen, Hong, E-mail: song.wei0326@163.com [National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Chen, Xin, E-mail: 742702437@qq.com [National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Zhang, Dong, E-mail: zhdongtj7021@sina.com [National Engineering Research Center of Urban Water Resources, Shanghai National Engineering Research Center of Urban Water Resources Co. Ltd, Shanghai 200082 (China); Chen, Hong-bin, E-mail: hbctxc@tongji.edu.cn [National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

2016-11-01

In order to improve our understanding of bio-activated carbon (BAC) filter, the water quality of influent and effluent treated with BAC in a drinking water treatment plant (DWTP) of Shanghai during 2015 was valued. Combining the results from UV{sub 254}, SUVA{sub 254}, dissolved organic carbon (DOC) and scanning electron microscopic (SEM), it is found that performance of BAC treatment will be affected by characteristics of activated carbon (AC), which is relevant to the type of activated carbon (including shape and operating time) in this study. Fluorescence excitation–emission matrix (FEEM) shows that the humification index (HIX) and index of recent autochthonous contribution (BIX) is a reliable indicator to descript the variation of dissolved organic matter (DOM) during BAC process. The pattern of variation in BIX and HIX implies that soluble microbial products (SMPs) are formed and humic-like substances are removed during BAC treatment, which is also confirmed by the change of peaks of FEEM in BAC effluent. Large, positive correlations between SUVA{sub 254} and disinfection by-products formation potential yield (DBPFP yield) demonstrate that UV-absorbing DOM is directly related to the generation of DBPs. Poor correlations of HIX with DBPFP suggest that non-humic substances with UV-absorbing properties play an important role in the generation of DBPs in water with low SUVA{sub 254}. Finally, strong but negative correlations between BIX and DBPFP suggest that vigorous microbial metabolism of BAC results in a decrease in DBPFP. However, the DBPFP yield will be enhanced for the generation of SMPs by BAC, especially in summer. - Highlights: • SMPs can be produced by BAC during drinking water advanced treatment. • BAC can reduce DBPFP, while there are risks associated with increasing DBPFP yield. • SUVA{sub 254} is strongly correlated with the DBPFP yields. • BIX is strongly correlated with DBPFP and THMFP, but weakly with HAAFP.

Experiment of Neutron Generation by Using Prototype D-D Neutron Generator

International Nuclear Information System (INIS)

Kim, In Jung; Kim, Suk Kwon; Park, Chang Su; Jung, Nam Suk; Jung, Hwa Dong; Park, Ji Young; Hwang, Yong Seok; Choi, H.D.

2005-01-01

Experiment of neutron generation was performed by using a prototype D-D neutron generator. The characteristics of D-D neutron generation in drive-in target was studied. The increment of neutron yield by increasing ion beam energy was investigated, too

Vibration characteristics of a hydraulic generator unit rotor system with parallel misalignment and rub-impact

Energy Technology Data Exchange (ETDEWEB)

Huang, Zhiwei; Zhou, Jianzhong; Yang, Mengqi; Zhang, Yongchuan [Huazhong University of Science and Technology, College of Hydraulic and Digitalization Engineering, Wuhan, Hubei Province (China)

2011-07-15

The object of this research aims at the hydraulic generator unit rotor system. According to fault problems of the generator rotor local rubbing caused by the parallel misalignment and mass eccentricity, a dynamic model for the rotor system coupled with misalignment and rub-impact is established. The dynamic behaviors of this system are investigated using numerical integral method, as the parallel misalignment, mass eccentricity and bearing stiffness vary. The nonlinear dynamic responses of the generator rotor and turbine rotor with coupling faults are analyzed by means of bifurcation diagrams, Poincare maps, axis orbits, time histories and amplitude spectrum diagrams. Various nonlinear phenomena in the system, such as periodic, three-periodic and quasi-periodic motions, are studied with the change of the parallel misalignment. The results reveal that vibration characteristics of the rotor system with coupling faults are extremely complex and there are some low frequencies with large amplitude in the 0.3-0.4 x components. As the increase in mass eccentricity, the interval of nonperiodic motions will be continuously moved forward. It suggests that the reduction in mass eccentricity or increase in bearing stiffness could preclude nonlinear vibration. These might provide some important theory references for safety operating and exact identification of the faults in rotating machinery. (orig.)

The next generation of power reactors - safety characteristics

International Nuclear Information System (INIS)

Modro, S.M.

1995-01-01

The next generation of commercial nuclear power reactors is characterized by a new approach to achieving reliability of their safety systems. In contrast to current generation reactors, these designs apply passive safety features that rely on gravity-driven transfer processes or stored energy, such as gas-pressurized accumulators or electric batteries. This paper discusses the passive safety system of the AP600 and Simplified Boiling Water Reactor (SBWR) designs

Formation and filtration characteristics of solids generated in a high level liquid waste treatment process. Filtration characteristics of solids formed in simulated high level liquid waste

International Nuclear Information System (INIS)

Kondo, Y.; Kubota, M.

1997-01-01

The filtration characteristics of solids generated in a simulated high level liquid waste (HLLW) were experimentally examined, when the simulated HLLW was processed according to the ordinary way of actual HLLW treatment process. The filtration characteristics of solids depended on the particle size. The phosphomolybdic acid, which was very fine particle with about 0.1 μm diameter, made slurry a 'difficult-to-filter' slurry, if the phosphomolybdic acid content (wt%) to the whole solids in a slurry exceeded 50wt%. On the contrary, the zirconium compounds (zirconium molybdate and zirconium telluride) had positive effect on filtration characteristics because of their relatively large particle size of about 3 to 5 μm. When the zirconium compounds content was above 50 wt%, slurry became a 'easy-to-filter' slurry. A centrifugal sedimentation was discussed as a solid/liquid separation technique for very fine particles such as phosphomolybdic acid. The theoretical feed flow rate corresponded to 0.1 μm diameter particles was about 20 1/h at the centrifugal acceleration of about 8000 G. (author)

Next-Generation Satellite Precipitation Products for Understanding Global and Regional Water Variability

Science.gov (United States)

Hou, Arthur Y.

2011-01-01

A major challenge in understanding the space-time variability of continental water fluxes is the lack of accurate precipitation estimates over complex terrains. While satellite precipitation observations can be used to complement ground-based data to obtain improved estimates, space-based and ground-based estimates come with their own sets of uncertainties, which must be understood and characterized. Quantitative estimation of uncertainties in these products also provides a necessary foundation for merging satellite and ground-based precipitation measurements within a rigorous statistical framework. Global Precipitation Measurement (GPM) is an international satellite mission that will provide next-generation global precipitation data products for research and applications. It consists of a constellation of microwave sensors provided by NASA, JAXA, CNES, ISRO, EUMETSAT, DOD, NOAA, NPP, and JPSS. At the heart of the mission is the GPM Core Observatory provided by NASA and JAXA to be launched in 2013. The GPM Core, which will carry the first space-borne dual-frequency radar and a state-of-the-art multi-frequency radiometer, is designed to set new reference standards for precipitation measurements from space, which can then be used to unify and refine precipitation retrievals from all constellation sensors. The next-generation constellation-based satellite precipitation estimates will be characterized by intercalibrated radiometric measurements and physical-based retrievals using a common observation-derived hydrometeor database. For pre-launch algorithm development and post-launch product evaluation, NASA supports an extensive ground validation (GV) program in cooperation with domestic and international partners to improve (1) physics of remote-sensing algorithms through a series of focused field campaigns, (2) characterization of uncertainties in satellite and ground-based precipitation products over selected GV testbeds, and (3) modeling of atmospheric processes and

Forced circulation type steam generator simulation code: HT4

International Nuclear Information System (INIS)

Okamoto, Masaharu; Tadokoro, Yoshihiro

1982-08-01

The purpose of this code is a understanding of dynamic characteristics of the steam generator, which is a component of High-temperature Heat Transfer Components Test Unit. This unit is a number 4th test section of Helium Engineering Demonstration Loop (HENDEL). Features of this report are as follows, modeling of the steam generator, a basic relationship for the continuity equation, numerical analysis techniques of a non-linear simultaneous equation and computer graphics output techniques. Forced circulation type steam generator with strait tubes and horizontal cut baffles, applied in this code, have be designed at the Over All System Design of the VHTRex. The code is for use with JAERI's digital computer FACOM M200. About 1.5 sec required for each time step reiteration, then about 40 sec cpu time required for a standard problem. (author)

Library design practices for success in lead generation with small molecule libraries.

Science.gov (United States)

Goodnow, R A; Guba, W; Haap, W

2003-11-01

The generation of novel structures amenable to rapid and efficient lead optimization comprises an emerging strategy for success in modern drug discovery. Small molecule libraries of sufficient size and diversity to increase the chances of discovery of novel structures make the high throughput synthesis approach the method of choice for lead generation. Despite an industry trend for smaller, more focused libraries, the need to generate novel lead structures makes larger libraries a necessary strategy. For libraries of a several thousand or more members, solid phase synthesis approaches are the most suitable. While the technology and chemistry necessary for small molecule library synthesis continue to advance, success in lead generation requires rigorous consideration in the library design process to ensure the synthesis of molecules possessing the proper characteristics for subsequent lead optimization. Without proper selection of library templates and building blocks, solid phase synthesis methods often generate molecules which are too heavy, too lipophilic and too complex to be useful for lead optimization. The appropriate filtering of virtual library designs with multiple computational tools allows the generation of information-rich libraries within a drug-like molecular property space. An understanding of the hit-to-lead process provides a practical guide to molecular design characteristics. Examples of leads generated from library approaches also provide a benchmarking of successes as well as aspects for continued development of library design practices.

Understanding the visual resource

Science.gov (United States)

Floyd L. Newby

1971-01-01

Understanding our visual resources involves a complex interweaving of motivation and cognitive recesses; but, more important, it requires that we understand and can identify those characteristics of a landscape that influence the image formation process. From research conducted in Florida, three major variables were identified that appear to have significant effect...

Natural gas for electric power generation: Strategic issues, risks and opportunities

International Nuclear Information System (INIS)

Linderman, C.

1992-01-01

Natural gas is again being regarded as a significant fuel for electric power generation. It was once a predominant fuel for utilities in gas-producing areas, but natural gas consumption declined greatly after the 1973 oil shock because of reduced electricity demand and increased coal and nuclear generation. Moreover, wellhead price and other forms of regulation produced gas shortages in the 1970s. The resurgence of natural gas in future resource plans stems from its inherent ideal fuel characteristics: short lead time; low capital costs; small increments of modular capacity; delivered close to load centers; environmentally benign, preferable to oil and coal; and potential for high thermal efficiency in gas turbines. Natural gas, if available and attractively priced, is an ideal fuel for electric power generation. No other fuel shares these attractive characteristics, and utilities, facing higher than expected load growth, are relying on an increasing proportion of gas-fired combustion turbines, combined cycle plants, and cogeneration to meet a growing, yet uncertain, future demand for electricity. Despite these desirable operating characteristics, the varied past and uncertain future of natural gas markets raise legitimate concerns about the riskiness of current utility natural gas strategies. This report, which summarizes the major findings from research efforts, is intended to help utility decision-makers understand the full range of risks they face with natural gas electric power generation and to identify actions they can take to mitigate those risks

Start-up support for New Brunswick Electric's Point Lepreau nuclear steam generators

International Nuclear Information System (INIS)

Schneider, W.; Leroux, A.

1983-05-01

The start-up of the 600 MW Point Lepreau reactor provided the opportunity for direct involvement in the important low and medium power start-up phase which was of particular interest because this was a first-of-a-kind reactor type incorporating a new steam generator design. Support included test assistance and test results interpretation for the thermal hydraulic performance of the steam generators and in particular, investigation of water level response to operating pressure, power and feed flow. This work resulted in both a greatly improved understanding of transient characteristics and in a number of beneficial refinements in the control methods

Preparing Generation Z for the Teaching Profession

Science.gov (United States)

Carter, Tim

2018-01-01

Generation Z, also known as the Homeland Generation, is the most recent generational cohort to enter the university setting. As with other generational cohorts, various shaping factors have impacted this group contributing to its unique and defining characteristics. When carefully considered, these characteristics may provide insight into how to…

An analysis of signal characteristics due to coil-gap variation of ECT bobbin probe for steam generation tube

International Nuclear Information System (INIS)

Nam, Min Woo; Cho, Chan Hee; Jee, Dong Hyun; Jung, Jee Hong; Lee, Hee Jong

2006-01-01

The bobbin probe technique is basically one of the important ECT methods for the steam generator tube integrity assesment that is practiced during each plant outage. The bobbin probe is one of the essential components which consist of the whole ECT examination system, and provides us a decisive data for the evaluation of tube integrity in compliance with acceptance criteria described in specific procedures. The selection of examination probe is especially important because the quality of acquired ECT data is determined by the probe design characteristics, geometry and operation frequencies, and has an important effect on examination results. In this study, the relationship between electric characteristic changes and differential coil gap variation has been investigated to optimize the ECT signal characteristics of the bobbin probe. With the results from this study, we have elucidated that the optimum coil gap is 1.2 - 1.6 mm that give the best result for O.D. volumetric defects in ASME calibration standards.

Towards understanding the impact of assimilating along-track SLA data on simulated eddy characteristics in the Agulhas System

CSIR Research Space (South Africa)

De Vos, M

2016-10-01

Full Text Available understanding the impact of assimilating along-track SLA data on simulated eddy characteristics in the Agulhas System Marc de Vos1, 3, Björn Backeberg2, 3, 4 and François Counillon4 Marine Research Unit, South African Weather Service, South Africa1 Coastal... and 1 Tel: +27 21 935 5764; Email: marc.devos@weathersa.co.za dipoles reach the Agulhas Current frequently and on occasion propagate all the way to the retroflection, influencing its position and modulating ring shedding events there (Schouten et al...

How Next-Generation Sequencing Has Aided Our Understanding of the Sequence Composition and Origin of B Chromosomes

Directory of Open Access Journals (Sweden)

Alevtina Ruban

2017-10-01

Full Text Available Accessory, supernumerary, or—most simply—B chromosomes, are found in many eukaryotic karyotypes. These small chromosomes do not follow the usual pattern of segregation, but rather are transmitted in a higher than expected frequency. As increasingly being demonstrated by next-generation sequencing (NGS, their structure comprises fragments of standard (A chromosomes, although in some plant species, their sequence also includes contributions from organellar genomes. Transcriptomic analyses of various animal and plant species have revealed that, contrary to what used to be the common belief, some of the B chromosome DNA is protein-encoding. This review summarizes the progress in understanding B chromosome biology enabled by the application of next-generation sequencing technology and state-of-the-art bioinformatics. In particular, a contrast is drawn between a direct sequencing approach and a strategy based on a comparative genomics as alternative routes that can be taken towards the identification of B chromosome sequences.

Microrelief-Controlled Overland Flow Generation: Laboratory and Field Experiments

Directory of Open Access Journals (Sweden)

Xuefeng Chu

2015-01-01

Full Text Available Surface microrelief affects overland flow generation and the related hydrologic processes. However, such influences vary depending on other factors such as rainfall characteristics, soil properties, and initial soil moisture conditions. Thus, in-depth research is needed to better understand and evaluate the combined effects of these factors on overland flow dynamics. The objective of this experimental study was to examine how surface microrelief, in conjunction with the factors of rainfall, soil, and initial moisture conditions, impacts overland flow generation and runoff processes in both laboratory and field settings. A series of overland flow experiments were conducted for rough and smooth surfaces that represented distinct microtopographic characteristics and the experimental data were analyzed and compared. Across different soil types and initial moisture conditions, both laboratory and field experiments demonstrated that a rough soil surface experienced a delayed initiation of runoff and featured a stepwise threshold flow pattern due to the microrelief-controlled puddle filling-spilling-merging dynamics. It was found from the field experiments that a smooth plot surface was more responsive to rainfall variations especially during an initial rainfall event. However, enhanced capability of overland flow generation and faster puddle connectivity of a rough field plot occurred during the subsequent rain events.

Acoustic characteristics of bubble bursting at the surface of a high-viscosity liquid

International Nuclear Information System (INIS)

Liu Xiao-Bo; Zhang Jian-Run; Li Pu

2012-01-01

An acoustic pressure model of bubble bursting is proposed. An experiment studying the acoustic characteristics of the bursting bubble at the surface of a high-viscosity liquid is reported. It is found that the sudden bursting of a bubble at the high-viscosity liquid surface generates N-shape wave at first, then it transforms into a jet wave. The fundamental frequency of the acoustic signal caused by the bursting bubble decreases linearly as the bubble size increases. The results of the investigation can be used to understand the acoustic characteristics of bubble bursting. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Model studies of the vertical steam generator thermal-hydraulic characteristics

International Nuclear Information System (INIS)

Desyatun, V.F.; Moskvichev, V.F.; Ulasov, V.M.; Morozov, V.G.; Burkov, V.K.; Grebennikov, V.N.

1984-01-01

Results of investigations conducted to clarify the calculation technique and to test the workability of the main elements and units of the PGV-250 vertical steam generator of saturated steam are considered. The steam generating capacity of the plant is 1486 t/h, thermal power is 792 MW. Steam generation follows a multiple circulation scheme. The heat surface comprises 330-shields. The investigations are carried out with a model which reproduces all the main elements of the steam generator xcluding the economizer section. The flow rates of feed water, generated steam and coolant of the first circuit as well as temperature, pressure and humidity of the generated steam past the separator are determined. The average heat transfer factors of the heat surface are calculated on the base of the data obtained and a conclusion is drawn on the correctness of the thermohydraulic calculation technique used in development of the PGV-250 steam generator design. Temperature pulsations and heat surface steaming are not observed. The steam humidity at the outlet and steam capture into sinking tubes are within permissible values

Characteristics of entropy generation and heat transfer in double-layered micro heat sinks with complex structure

International Nuclear Information System (INIS)

Zhai, Y.L.; Xia, G.D.; Liu, X.F.; Wang, J.

2015-01-01

Highlights: • A novel DL-MCHS with complex structure is presented. • A model of entropy generation rate of DL-MCHSs is derived from the first and second laws of thermodynamics. • DL-MCHSs show better thermodynamic advantage and thermal performance under large volumetric flow rate. - Abstract: A new type of double-layered micro heat sink (DL-MCHS) with complex structure is designed and investigated numerically. Moreover, a model of entropy generation rate of DL-MCHSs is also derived from the first and second laws of thermodynamics. Results for the relationship of entropy generation rate between the first and second layer of DL-MCHSs, total entropy generation rate, the average temperature on the bottom wall, thermal resistance and pressure drop are investigated in detail, respectively. The results indicate that the effect of entropy generation rate of the first layer on total entropy generation rate is dominant. The thermal characteristic of DL-MCHSs with complex structure is better than that of all DL-MCHSs and single-layered micro heat sinks (SL-MCHSs) with simple structure under the same volumetric flow rate. However, DL-MCHSs only show better thermodynamic advantage and thermal performance than SL-MCHSs with complex structure when the volumetric flow rate larger than a certain value. It is not reasonable to use DL-MCHSs for cooling microelectronic equipments under small volumetric flow rate due to the larger irreversibility. Finally, the pressure drop of DL-MHCSs can be reduced by properly changing the channel height under various volumetric flow rates. Due to the less irreversibility and more uniform temperature distribution on the bottom wall, DL-MCHSs can effectively eliminate the internal thermal stresses in microelectronic equipments. Therefore, DL-MCHSs are an alternative method for the electronic cooling. Moreover, the thermodynamic analysis provides references for the actual application design

Use of second-generation antipsychotic agents for sleep and sedation: a provider survey.

Science.gov (United States)

Hermes, Eric D A; Sernyak, Michael; Rosenheck, Robert

2013-04-01

Anecdotal evidence suggests that second-generation antipsychotic agents are increasingly used to treat sleep problems. This study sought to quantify the proportion of new prescriptions for second-generation antipsychotic agents started for sleep/sedation and the correlates of such use. A cross-sectional survey of provider decision making at the time second-generation antipsychotic agents were prescribed, documenting the reasons for the medication, patient demographics, psychiatric and medical diagnoses, patient health characteristics, and provider background. A single Veterans Affairs Medical Center over a 20-month period. Prescribers of second-generation antipsychotic agents. N/A. Seven hundred seven (32.2%) of 2,613 surveys indicated sleep/sedation was at least one reason for using a second-generation anti-psychotic agent, whereas for 266 (12.1%) it was the only reason. Quetiapine was most frequently prescribed overall as well as for sleep/sedation (47.0% and 73.6% respectively). Second-generation antipsychotic agent use for sleep/sedation was unrelated to sociodemographic characteristics, least likely in patients with schizophrenia or bipolar disorder, and most likely as a newly started second-generation antipsychotic agent. Sleep/sedation is a common reason given for new prescriptions of second-generation antipsychotic agents. Quetiapine is most frequently used for this purpose. A greater understanding of why providers use second-generation antipsychotic agents rather than safer and less costly alternatives for sleep problems may advance the development of interventions to reduce adverse effects.

Spectral characteristics of a relativistic plasma microwave generator

International Nuclear Information System (INIS)

Kuzelev, M.V.; Loza, O.T.; Ponomarev, A.V.; Rukhadze, A.A.; Strelkov, P.S.; Ul'yanov, D.K.; Shkvarunets, A.G.

1996-01-01

The radiation spectrum of a broad-band relativistic plasma microwave generator, in which a hollow relativistic electron beam is injected into a plasma waveguide consisting of a hollow plasma within a round metallic waveguide is measured experimentally. The radiation spectrum is measured using a wide-aperture calorimetric spectrometer in the frequency range 3-32 GHz. The influence of the plasma density and the beam-plasma gap on the radiation spectrum is investigated. The amplification of the noise electromagnetic radiation when a relativistic electron beam is injected into the plasma waveguide is calculated on the basis of the nonlinear theory. The theory predicts passage from a one-particle generation regime to a collective regime and narrowing of the radiation spectrum as the plasma density and the gap between the hollow beam and the plasma increases. A comparison of the measurement results with the nonlinear theory accounts for several features of the measured spectrum. However, the predicted change in the generation regimes is not observed experimentally. Qualitative arguments are advanced, which explain the observed phenomena and call for further theoretical and experimental research, are advanced

Now You See It… Now You Don’t: Understanding Airborne Mapping LiDAR Collection and Data Product Generation for Archaeological Research in Mesoamerica

Directory of Open Access Journals (Sweden)

Juan Carlos Fernandez-Diaz

2014-10-01

Full Text Available In this paper we provide a description of airborne mapping LiDAR, also known as airborne laser scanning (ALS, technology and its workflow from mission planning to final data product generation, with a specific emphasis on archaeological research. ALS observations are highly customizable, and can be tailored to meet specific research needs. Thus it is important for an archaeologist to fully understand the options available during planning, collection and data product generation before commissioning an ALS survey, to ensure the intended research questions can be answered with the resultant data products. Also this knowledge is of great use for the researcher trying to understand the quality and limitations of existing datasets collected for other purposes. Throughout the paper we use examples from archeological ALS projects to illustrate the key concepts of importance for the archaeology researcher.

Evaluating the Psychometric Characteristics of Generated Multiple-Choice Test Items

Science.gov (United States)

Gierl, Mark J.; Lai, Hollis; Pugh, Debra; Touchie, Claire; Boulais, André-Philippe; De Champlain, André

2016-01-01

Item development is a time- and resource-intensive process. Automatic item generation integrates cognitive modeling with computer technology to systematically generate test items. To date, however, items generated using cognitive modeling procedures have received limited use in operational testing situations. As a result, the psychometric…

Generative Semantics.

Science.gov (United States)

King, Margaret

The first section of this paper deals with the attempts within the framework of transformational grammar to make semantics a systematic part of linguistic description, and outlines the characteristics of the generative semantics position. The second section takes a critical look at generative semantics in its later manifestations, and makes a case…

Cue generation and memory construction in direct and generative autobiographical memory retrieval.

Science.gov (United States)

Harris, Celia B; O'Connor, Akira R; Sutton, John

2015-05-01

Theories of autobiographical memory emphasise effortful, generative search processes in memory retrieval. However recent research suggests that memories are often retrieved directly, without effortful search. We investigated whether direct and generative retrieval differed in the characteristics of memories recalled, or only in terms of retrieval latency. Participants recalled autobiographical memories in response to cue words. For each memory, they reported whether it was retrieved directly or generatively, rated its visuo-spatial perspective, and judged its accompanying recollective experience. Our results indicated that direct retrieval was commonly reported and was faster than generative retrieval, replicating recent findings. The characteristics of directly retrieved memories differed from generatively retrieved memories: directly retrieved memories had higher field perspective ratings and lower observer perspective ratings. However, retrieval mode did not influence recollective experience. We discuss our findings in terms of cue generation and content construction, and the implication for reconstructive models of autobiographical memory. Copyright © 2015 Elsevier Inc. All rights reserved.

Generation characteristics of photovoltaic power generation equipment at TEPCO R and D center; Gijutsu kaihatsu center taiyoko hatsuden setsubi no hatsuden tokusei

Energy Technology Data Exchange (ETDEWEB)

Amano, K; Natori, K [Tokyo Electric Power Co. Inc., Tokyo (Japan)

1997-11-25

Solar battery arrays are installed at different tilt angles for actual measurement in an experiment conducted by TEPCO (Tokyo Electric Power Company, Inc.) Research and Development Center for the examination of their power generation characteristics. Arrays of polycrystalline silicon solar battery modules are positioned facing a direction +7 degrees swung from the south on the Center rooftop and verandah, and they are installed at tilt angles of 0, 30, 60, and 90 degrees. An analysis of system characteristics is conducted, and findings mentioned below are obtained. In fiscal 1996, the highest utilization factor of a yearly average of 11.3% is attained with the ones tilted at 30 degrees. As for the utilization factors at the other angles, they are 10.2% at 60 degrees, 8.8% at 0 degrees, and 8.0% at 90 degrees. The integrated design coefficient remains approximately constant irrespective of the different tilt angles of 0, 30, and 60 degrees. The overall design coefficient of the 90 degree-tilted array installed on the verandah is found to be 0.75, which is higher than those exhibited by the others. Appropriate routes of wirings for modules should be worked out to avoid the ill effect of the shadows of steel towers. 2 refs., 11 figs.

Quantifying physical characteristics of wildland fuels using the fuel characteristic classification system.

Science.gov (United States)

Cynthia L. Riccardi; Susan J. Prichard; David V. Sandberg; Roger D. Ottmar

2007-01-01

Wildland fuel characteristics are used in many applications of operational fire predictions and to understand fire effects and behaviour. Even so, there is a shortage of information on basic fuel properties and the physical characteristics of wildland fuels. The Fuel Characteristic Classification System (FCCS) builds and catalogues fuelbed descriptions based on...

Various Characteristics of Electromagnetic Contactor when Arc Discharge are Generated only Make Arc(Researches and Overseas Activities)--(Reports of Overseas Activities)

OpenAIRE

Kiyoshi, Yoshida

2017-01-01

Experiments are carried out to clarify the influence on the current and voltage for various characteristics.A small electromagnetic contactor that has two contacts is used.The arc discharge with only a make arc is generated and various characteristics are measured.Source voltage is set to 100V DC, closed contacts currents are changed from 10A 20A and 30A.From the waveforms, the arc duration time and the bounce time are read out.Arc energy is calculated from the arc voltage and arc current.The...

Development of a testlet generator in re-engineering the Indonesian physics national-exams

Science.gov (United States)

Mindyarto, Budi Naini; Mardapi, Djemari; Bastari

2017-08-01

The Indonesian Physics national-exams are end-of-course summative assessments that could be utilized to support the assessment for learning in physics educations. This paper discusses the development and evaluation of a testlet generator based on a re-engineering of Indonesian physics national exams. The exam problems were dissected and decomposed into testlets revealing the deeper understanding of the underlying physical concepts by inserting a qualitative question and its scientific reasoning question. A template-based generator was built to facilitate teachers in generating testlet variants that would be more conform to students' scientific attitude development than their original simple multiple-choice formats. The testlet generator was built using open source software technologies and was evaluated focusing on the black-box testing by exploring the generator's execution, inputs and outputs. The results showed the correctly-performed functionalities of the developed testlet generator in validating inputs, generating testlet variants, and accommodating polytomous item characteristics.

A Parallel Restoration for Black Start of Microgrids Considering Characteristics of Distributed Generations

Directory of Open Access Journals (Sweden)

Jing Wang

2017-12-01

Full Text Available The black start capability is vital for microgrids, which can potentially improve the reliability of the power grid. This paper proposes a black start strategy for microgrids based on a parallel restoration strategy. Considering the characteristics of distributed generations (DGs, an evaluation model, which is used to assess the black start capability of DGs, is established by adopting the variation coefficient method. Thus, the DGs with good black start capability, which are selected by a diversity sequence method, are restored first in parallel under the constraints of DGs and network. During the selection process of recovery paths, line weight and node importance degree are proposed under the consideration of the node topological importance and the load importance as well as the backbone network restoration time. Therefore, the whole optimization of the reconstructed network is realized. Finally, the simulation results verify the feasibility and effectiveness of the strategy.

Generational differences in work ethic among 3 generations of registered nurses.

Science.gov (United States)

Jobe, Laura L

2014-05-01

The purpose of this study was to understand if differences in dimensions of work ethic exist among 3 generations of nurses working in an inpatient setting at an acute care facility. Generational differences are linked with increased turnover, with work ethic frequently cited as an important difference. The quantitative, quasi-experimental cross-sectional study recruited inpatient registered nurses from 2 teaching hospitals in a southern US metropolitan area to complete the Multidimensional Work Ethic Profile online. The 285 completed surveys indicated that similarities exist among the 3 generations, with statistically significant differences only in leisure, hard work, and delay of gratification dimensions. Understanding differences in work ethic dimensions could lead to strategies for improving the generational conflict. These results also lead to the conclusion that work ethic differences may not be the cause of the generational conflict among nurses.

Influences of coal slag on electrical characteristics of a Faraday MHD generator

International Nuclear Information System (INIS)

Yoshida, M.; Umoto, J.

1989-01-01

In order to clarify the influence of coal slag on the electrical characteristics of a large scale Faraday MHD generator, numerical analysis by a new equivalent circuit method is performed. At first, an equivalent circuit for a space element in the Faraday channel and a slag layer element are derived. Next, the numerical results are compared with the experimental ones obtained from the ETL Mark VII. The results are: (1) when the thickness, conductivity, etc. of the slag are nonuniform the distribution of not only the load voltage, but also the voltage between adjacent electrodes, becomes nonuniform, and the latter may cause interelectrode breakdown; (2) when shorting over several cathodes occurs a typical distribution of the load voltage appears near the shorted region, in which, at first, the load voltage rises a little, then decreases gradually, and finally, recovers rapidly to the normal voltage along the gas flow. As a result of the short-circuit, the distribution of the voltage between adjacent electrodes is made significantly nonuniform, and this may lead to another inter-electrode breakdown. (author)

Effect of operation conditions of the drop-on-demand aerosol generator on aerosol characteristics: Pseudo-cinematographic and plasma mass spectrometric studies

International Nuclear Information System (INIS)

Orlandini von Niessen, Jan O.; Krone, Karin M.; Bings, Nicolas H.

2014-01-01

The recently presented drop-on-demand (DOD) aerosol generator overcomes some of the drawbacks of pneumatic nebulization, as its aerosol is no longer generated by gas–liquid interaction. In the current study, an advanced imaging technique is presented, based on a CCD camera equipped with magnifying telecentric optics to allow for fast, automated and precise aerosol characterization as well as fundamental studies on the droplet generation processes by means of pseudo-cinematography. The DOD aerosol generator is thoroughly characterized regarding its droplet size distribution, which shows few distinct populations rather than a continuous distribution. Other important figures, such as the Sauter diameter (D 3,2 ) of 22 μm and the span of 0.4 were also determined. Additionally, the influence of the electrical operation conditions of the dosing device on the aerosol generation process is described. The number and volume of the generated droplets were found to be very reproducible and user-variable, e.g. from 17 to 27 μm (D 3,2 ), within a span of 0.07–0.89. The performances of different setups of the DOD as liquid sample introduction system in ICP-MS are correlated to the respective achievable aerosol characteristics and are also compared to the performance of a state-of-the-art μ-flow nebulizer (EnyaMist). The DOD system allowed for improved sensitivity, but slightly elevated signal noise and overall comparable limits of detection. The results are critically discussed and future directions are outlined. - Graphical abstract: Further characterization of the drop-on-demand aerosol generator for sample introduction in atomic spectrometry. - Highlights: • Significantly improved ICP-MS sensitivity using the DOD vs. EnyaMist. • Comparable detection limits but slightly worse short-term precision. • Superior flexibility compared with conventional/miniaturized pneumatic nebulizers. • Electrical operation conditions of the DOD influence aerosol characteristics. �

Effect of operation conditions of the drop-on-demand aerosol generator on aerosol characteristics: Pseudo-cinematographic and plasma mass spectrometric studies

Energy Technology Data Exchange (ETDEWEB)

Orlandini von Niessen, Jan O.; Krone, Karin M.; Bings, Nicolas H., E-mail: bings@uni-mainz.de

2014-02-01

The recently presented drop-on-demand (DOD) aerosol generator overcomes some of the drawbacks of pneumatic nebulization, as its aerosol is no longer generated by gas–liquid interaction. In the current study, an advanced imaging technique is presented, based on a CCD camera equipped with magnifying telecentric optics to allow for fast, automated and precise aerosol characterization as well as fundamental studies on the droplet generation processes by means of pseudo-cinematography. The DOD aerosol generator is thoroughly characterized regarding its droplet size distribution, which shows few distinct populations rather than a continuous distribution. Other important figures, such as the Sauter diameter (D{sub 3,2}) of 22 μm and the span of 0.4 were also determined. Additionally, the influence of the electrical operation conditions of the dosing device on the aerosol generation process is described. The number and volume of the generated droplets were found to be very reproducible and user-variable, e.g. from 17 to 27 μm (D{sub 3,2}), within a span of 0.07–0.89. The performances of different setups of the DOD as liquid sample introduction system in ICP-MS are correlated to the respective achievable aerosol characteristics and are also compared to the performance of a state-of-the-art μ-flow nebulizer (EnyaMist). The DOD system allowed for improved sensitivity, but slightly elevated signal noise and overall comparable limits of detection. The results are critically discussed and future directions are outlined. - Graphical abstract: Further characterization of the drop-on-demand aerosol generator for sample introduction in atomic spectrometry. - Highlights: • Significantly improved ICP-MS sensitivity using the DOD vs. EnyaMist. • Comparable detection limits but slightly worse short-term precision. • Superior flexibility compared with conventional/miniaturized pneumatic nebulizers. • Electrical operation conditions of the DOD influence aerosol

Understanding quantum physics

International Nuclear Information System (INIS)

Spillner, Vera

2011-01-01

This thesis presents a bundle definition for 'scientific understanding' through which the empirically equivalent interpretations of quantum mechanics can be evaluated with respect to the understanding they generate. The definition of understanding is based on a sufficient and necessary criterion, as well as a bundle of conditions - where a theory can be called most understandable whenever it fulfills the highest number of bundle criteria. Thereby the definition of understanding is based on the one hand on the objective number of criteria a theory fulfills, as well as, on the other hand, on the individual's preference of bundle criteria. Applying the definition onto three interpretations of quantum mechanics, the interpretation of David Bohm appears as most understandable, followed by the interpretation of Tim Maudlin and the Kopenhagen interpretation. These three interpretations are discussed in length in my thesis. (orig.)

Experimental and numerical investigations of radiation characteristics of Russian portable/compact pulsed neutron generators: ING-031, ING-07, ING-06 and ING-10-20-120

International Nuclear Information System (INIS)

Chernikova, D.; Romodanov, V.L.; Belevitin, A.G.; Afanas'ev, V.V.; Sakharov, V.K.; Bogolubov, E.P.; Ryzhkov, V.I.; Khasaev, T.O.; Sladkov, A.A.; Bitulev, A.A.

2014-01-01

The present paper discusses results of full-scale experimental and numerical investigations of influence of construction materials of portable pulsed neutron generators ING-031, ING-07, ING-06 and ING-10-20-120 (VNIIA, Russia) to their radiation characteristics formed during and after an operation (shutdown period). In particular, it is shown that an original monoenergetic isotropic angular distribution of neutrons emitted by TiT target changes into the significantly anisotropic angular distribution with a broad energy spectrum stretching to the thermal region. Along with the low-energetic neutron part, a significant amount of photons appears during the operation of generators. In the pulse mode of operation of neutron generator, a presence of the construction materials leads to the “tailing” of the original neutron pulse and the appearance of an accompanying photon pulse at ∼3ns after the instant neutron pulse. In addition to that, reactions of neutron capture and inelastic scattering lead to the creation of radioactive nuclides, such as 58 Co, 62 Cu, 64 Cu and 18 F, which form the so-called activation radiation. Thus, the selection of a portable neutron generator for a particular type of application has to be done considering radiation characteristics of the generator itself. This paper will be of interest to users of neutron generators, providing them with valuable information about limitations of a specific generator and with recommendations for improving the design and performance of the generator as a whole

Multi-Objective Planning of Multi-Type Distributed Generation Considering Timing Characteristics and Environmental Benefits

Directory of Open Access Journals (Sweden)

Yajing Gao

2014-09-01

Full Text Available This paper presents a novel approach to multi-type distributed generation (DG planning based on the analysis of investment and income brought by grid-connected DG. Firstly, the timing characteristics of loads and DG outputs, as well as the environmental benefits of DG are analyzed. Then, on the basis of the classification of daily load sequences, the typical daily load sequence and the typical daily output sequence of DG per unit capacity can be computed. The proposed planning model takes the location, capacity and types of DG into account as optimization variables. An improved adaptive genetic algorithm is proposed to solve the model. Case studies have been carried out on the IEEE 14-node distribution system to verify the feasibility and effectiveness of the proposed method and model.

Generation of soluble microbial products by bio-activated carbon filter during drinking water advanced treatment and its influence on spectral characteristics

International Nuclear Information System (INIS)

Shen, Hong; Chen, Xin; Zhang, Dong; Chen, Hong-bin

2016-01-01

In order to improve our understanding of bio-activated carbon (BAC) filter, the water quality of influent and effluent treated with BAC in a drinking water treatment plant (DWTP) of Shanghai during 2015 was valued. Combining the results from UV_2_5_4, SUVA_2_5_4, dissolved organic carbon (DOC) and scanning electron microscopic (SEM), it is found that performance of BAC treatment will be affected by characteristics of activated carbon (AC), which is relevant to the type of activated carbon (including shape and operating time) in this study. Fluorescence excitation–emission matrix (FEEM) shows that the humification index (HIX) and index of recent autochthonous contribution (BIX) is a reliable indicator to descript the variation of dissolved organic matter (DOM) during BAC process. The pattern of variation in BIX and HIX implies that soluble microbial products (SMPs) are formed and humic-like substances are removed during BAC treatment, which is also confirmed by the change of peaks of FEEM in BAC effluent. Large, positive correlations between SUVA_2_5_4 and disinfection by-products formation potential yield (DBPFP yield) demonstrate that UV-absorbing DOM is directly related to the generation of DBPs. Poor correlations of HIX with DBPFP suggest that non-humic substances with UV-absorbing properties play an important role in the generation of DBPs in water with low SUVA_2_5_4. Finally, strong but negative correlations between BIX and DBPFP suggest that vigorous microbial metabolism of BAC results in a decrease in DBPFP. However, the DBPFP yield will be enhanced for the generation of SMPs by BAC, especially in summer. - Highlights: • SMPs can be produced by BAC during drinking water advanced treatment. • BAC can reduce DBPFP, while there are risks associated with increasing DBPFP yield. • SUVA_2_5_4 is strongly correlated with the DBPFP yields. • BIX is strongly correlated with DBPFP and THMFP, but weakly with HAAFP.

Heat transfer characteristics in a sudden expansion pipe equipped with swirl generators

International Nuclear Information System (INIS)

Zohir, A.E.; Abdel Aziz, A.A.; Habib, M.A.

2011-01-01

This investigation is aimed at studying the heat transfer characteristics and pressure drop for turbulent airflow in a sudden expansion pipe equipped with propeller type swirl generator or spiral spring with several pitch ratios. The investigation is performed for the Reynolds number ranging from 7500 to 18,500 under a uniform heat flux condition. The experiments are also undertaken for three locations for the propeller fan (N = 15 blades and blade angle of 65 o ) and three pitch ratios for the spiral spring (P/D = 10, 15 and 20). The influences of using the propeller rotating freely and inserted spiral spring on heat transfer enhancement and pressure drop are reported. In the experiments, the swirl generator and spiral spring are used to create a swirl in the tube flow. Mean and relative mean Nusselt numbers are determined and compared with those obtained from other similar cases. The experimental results indicate that the tube with the propeller inserts provides considerable improvement of the heat transfer rate over the plain tube around 1.69 times for X/H = 5. While for the tube with the spiral spring inserts, an improvement of the heat transfer rate over the plain tube around 1.37 times for P/d = 20. Thus, because of strong swirl or rotating flow, the propeller location and the spiral spring pitch become influential on the heat transfer enhancement. The increase in pressure drop using the propeller is found to be three times and for spiral spring 1.5 times over the plain tube. Correlations for mean Nusselt number, fan location and spiral spring pitch are provided.

Characteristics of reading and understanding of hearing impaired students in classes VI-VIII

Directory of Open Access Journals (Sweden)

Mustaf Morina

2015-03-01

impairment have stagnated compared with their peers in 8/1. Significant differences exist even within the group of deaf students in the three aspects of the study based on three dimensions of text, the terms of the speed of reading, significant differences exist also in the manifestation of errors and understanding of the text. Differences are also evident in terms of the degree of the hearing impairment, in terms of age and gender within the group of the deaf; this means that individual characteristics of students represent important facts.

Beyond OCR : Multi-faceted understanding of handwritten document characteristics

NARCIS (Netherlands)

He, Sheng; Schomaker, Lambert

Handwritten document understanding is a fundamental research problem in pattern recognition and it relies on the effective features. In this paper, we propose a joint feature distribution (JFD) principle to design novel discriminative features which could be the joint distribution of features on

Profiling of Intracellular Metabolites: An Approach to Understanding the Characteristic Physiology of Mycobacterium leprae.

Science.gov (United States)

Miyamoto, Yuji; Mukai, Tetsu; Matsuoka, Masanori; Kai, Masanori; Maeda, Yumi; Makino, Masahiko

2016-08-01

Mycobacterium leprae is the causative agent of leprosy and also known to possess unique features such as inability to proliferate in vitro. Among the cellular components of M. leprae, various glycolipids present on the cell envelope are well characterized and some of them are identified to be pathogenic factors responsible for intracellular survival in host cells, while other intracellular metabolites, assumed to be associated with basic physiological feature, remain largely unknown. In the present study, to elucidate the comprehensive profile of intracellular metabolites, we performed the capillary electrophoresis-mass spectrometry (CE-MS) analysis on M. leprae and compared to that of M. bovis BCG. Interestingly, comparison of these two profiles showed that, in M. leprae, amino acids and their derivatives are significantly accumulated, but most of intermediates related to central carbon metabolism markedly decreased, implying that M. leprae possess unique metabolic features. The present study is the first report demonstrating the unique profiles of M. leprae metabolites and these insights might contribute to understanding undefined metabolism of M. leprae as well as pathogenic characteristics related to the manifestation of the disease.

Generation and discourse in working life stories.

Science.gov (United States)

Foster, Karen

2013-06-01

Following Mannheim's (1970) Problem of Generations, many scholars have warned of the analytical and political risks of conflating generation with cohort. Yet the temptation persists, as relying on cohort is a convenient method of dividing a population to study it. This article proposes that cohort is only convenient if the objective is understanding generations as definitive groups of people. It suggests a supplementary objective: understanding generation as a matter of discourse. Qualitative data from interviews with 52 Canadians illustrates how the discursive forms of generation in their stories render difference, human agency and social change in atomistic or voluntaristic terms. The most extreme manifestations of this theme appear related to the perception of generational conflict. Guided by James' principle of pragmatism, this article maintains that understanding generation as a discursive, historically contingent 'thought' with 'effects' is as important as understanding its structural form and contents. © London School of Economics and Political Science 2013.

Public attitudes toward nuclear power generation. Preliminary study focusing on characteristics of the attitudes of men and women

International Nuclear Information System (INIS)

Maruyama, Naoko; Misumi, Jyuji; Yanagihara, Ryozo; Hayashi, Chikio.

1996-01-01

The purpose of this study is to approach the public attitudes toward nuclear power generation and related matters by focusing on the viewpoint of differences between men and women. More specifically, it was attempted to determine what types of lifestyles and ways of thinking are associated with persons indicating the respective attitudes, what types of anxiety these people have with respect to nuclear power generation, as well as the nature of the inflexibility of those attitudes. As a result, well-defined characteristics were found to be associated with each attitude. In addition, the types of anxiety with respect to nuclear power generation were able to be broadly classified into emotional anxiety and logical anxiety. Regarding the inflexibility of these attitudes, although men tended to exhibit little change concerning positive attitudes, they tended to easily change in the negative direction as a result of negative information. In the case of women, conversely, although their attitudes tended to change easily toward the affirmative direction when presented with positive information, it was determined that women tend to change very little toward the negative direction. (author)

Modeling and analysis with induction generators

CERN Document Server

Simões, M Godoy

2014-01-01

ForewordPrefaceAcknowledgmentsAuthorsPrinciples of Alternative Sources of Energy and Electric GenerationScope of This ChapterLegal DefinitionsPrinciples of Electrical ConversionBasic Definitions of Electrical PowerCharacteristics of Primary SourcesCharacteristics of Remote Industrial, Commercial, and Residential Sites and Rural EnergySelection of the Electric GeneratorInterfacing Primary Source, Generator, and LoadExample of a Simple Integrated Generating and Energy-Storing SystemSolved ProblemsSuggested ProblemsReferencesSteady-State Model of Induction GeneratorsScope of This ChapterInterconnection and Disconnection of the Electric Distribution NetworkRobustness of Induction GeneratorsClassical Steady-State Representation of the Asynchronous MachineGenerated PowerInduced TorqueRepresentation of Induction Generator LossesMeasurement of Induction Generator ParametersBlocked Rotor Test (s = 1)No-Load Test (s = 0)Features of Induction Machines Working as Generators Interconnected to the Distribution NetworkHigh-...

Emotion-driven level generation

OpenAIRE

Togelius, Julian; Yannakakis, Georgios N.

2016-01-01

This chapter examines the relationship between emotions and level generation. Grounded in the experience-driven procedural content generation framework we focus on levels and introduce a taxonomy of approaches for emotion-driven level generation. We then review four characteristic level generators of our earlier work that exemplify each one of the approaches introduced. We conclude the chapter with our vision on the future of emotion-driven level generation.

Network Characteristics and the Value of Collaborative User-Generated Content

OpenAIRE

Sam Ransbotham; Gerald C. Kane; Nicholas H. Lurie

2012-01-01

User-generated content is increasingly created through the collaborative efforts of multiple individuals. In this paper, we argue that the value of collaborative user-generated content is a function both of the direct efforts of its contributors and of its embeddedness in the content-contributor network that creates it. An analysis of Wikipedia's WikiProject Medicine reveals a curvilinear relationship between the number of distinct contributors to user-generated content and viewership. A two-...

Investigation on the generation characteristic of pressure pulse wave signal during the measurement-while-drilling process

Science.gov (United States)

Changqing, Zhao; Kai, Liu; Tong, Zhao; Takei, Masahiro; Weian, Ren

2014-04-01

The mud-pulse logging instrument is an advanced measurement-while-drilling (MWD) tool and widely used by the industry in the world. In order to improve the signal transmission rate, ensure the accurate transmission of information and address the issue of the weak signal on the ground of oil and gas wells, the signal generator should send out the strong mud-pulse signals with the maximum amplitude. With the rotary valve pulse generator as the study object, the three-dimensional Reynolds NS equations and standard k - ɛ turbulent model were used as a mathematical model. The speed and pressure coupling calculation was done by simple algorithms to get the amplitudes of different rates of flow and axial clearances. Tests were done to verify the characteristics of the pressure signals. The pressure signal was captured by the standpiece pressure monitoring system. The study showed that the axial clearances grew bigger as the pressure wave amplitude value decreased and caused the weakening of the pulse signal. As the rate of flow got larger, the pressure wave amplitude would increase and the signal would be enhanced.

Next-generation sequencing approaches to understanding the oral microbiome

NARCIS (Netherlands)

Zaura, E.

2012-01-01

Until recently, the focus in dental research has been on studying a small fraction of the oral microbiome—so-called opportunistic pathogens. With the advent of next-generation sequencing (NGS) technologies, researchers now have the tools that allow for profiling of the microbiomes and metagenomes at

Characteristic of nanoparticles generated from different nano-powders by using different dispersion methods

International Nuclear Information System (INIS)

Tsai, Chuen-Jinn; Lin, Guan-Yu; Liu, Chun-Nan; He, Chi-En; Chen, Chun-Wan

2012-01-01

A standard rotating drum with a modified sampling train (RD), a vortex shaker (VS), and a SSPD (small-scale powder disperser) were used to investigate the emission characteristics of nano-powders, including nano-titanium dioxide (nano-TiO 2 , primary diameter: 21 nm), nano-zinc oxide (nano-ZnO, primary diameter: 30–50 nm), and nano-silicon dioxide (nano-SiO 2 , primary diameter: 10–30 nm). A TSI SMPS (scanning mobility particle sizer), a TSI APS (aerodynamic particle sizer), and a MSP MOUDI (micro-orifice uniform deposit impactor) were used to measure the number and mass distributions of generated particles. Significant differences in specific number and mass concentration or distributions were found among different methods and nano-powders with the most specific number and mass concentration and the smallest particles being generated by the most energetic SSPD, followed by VS and RD. Near uni-modal number or mass distributions were observed for the SSPD while bi-modal number or mass distributions existed for nano-powders except nano-SiO 2 which also exhibited bimodal mass distributions. The 30-min average results showed that the mass median aerodynamic diameter (MMAD) and number median diameter (NMD) of the SSPD ranged 1.1–2.1 μm and 166–261 nm, respectively, for all three nano-powders, which were smaller than those of the VS (MMAD: 3.3–6.0 μm and NMD: 156–462 nm), and the RD (MMAD: 5.2–11.2 μm and NMD: 198–479 nm). For nano-particles (electric mobility diameter < 100 nm), specific mass concentrations were nearly negligible for all three nano-powders and test methods. Specific number concentrations of nano-particles were low for the RD tester but were elevated when more energetic VS and SSPD testers were used. The quantitative size and concentration data obtained in this study is useful to elucidate the field emission and personal exposure data in the future provided that particle loss in the generation system is carefully assessed.

Analysis of current-voltage characteristics of Au/pentacene/fluorine polymer/indium zinc oxide diodes by electric-field-induced optical second-harmonic generation

Energy Technology Data Exchange (ETDEWEB)

Nishi, Shohei; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 S3-33, O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

2015-06-28

By using electric-field-induced optical second-harmonic generation measurement coupled with the conventional current-voltage (I-V) measurement, we studied the carrier transport of organic double-layer diodes with a Au/pentacene/fluorine polymer (FP)/indium zinc oxide (IZO) structure. The rectifying I-V characteristics were converted into the I-E characteristics of the FP and pentacene layers. Results suggest a model in which Schottky-type electron injection from the IZO electrode to the FP layer governs the forward electrical conduction (V > 0), where the space charge electric field produced in the FP layer by accumulated holes at the pentacene/FP interface makes a significant contribution. On the other hand, Schottky-type injection by accumulated interface electrons from the pentacene layer to the FP layer governs the backward electrical conduction (V < 0). The electroluminescence generated from the pentacene layer in the region V > 0 verifies the electron transport across the FP layer, and supports the above suggested model.

Analysis of current-voltage characteristics of Au/pentacene/fluorine polymer/indium zinc oxide diodes by electric-field-induced optical second-harmonic generation

International Nuclear Information System (INIS)

Nishi, Shohei; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

2015-01-01

By using electric-field-induced optical second-harmonic generation measurement coupled with the conventional current-voltage (I-V) measurement, we studied the carrier transport of organic double-layer diodes with a Au/pentacene/fluorine polymer (FP)/indium zinc oxide (IZO) structure. The rectifying I-V characteristics were converted into the I-E characteristics of the FP and pentacene layers. Results suggest a model in which Schottky-type electron injection from the IZO electrode to the FP layer governs the forward electrical conduction (V > 0), where the space charge electric field produced in the FP layer by accumulated holes at the pentacene/FP interface makes a significant contribution. On the other hand, Schottky-type injection by accumulated interface electrons from the pentacene layer to the FP layer governs the backward electrical conduction (V < 0). The electroluminescence generated from the pentacene layer in the region V > 0 verifies the electron transport across the FP layer, and supports the above suggested model

Measurement of tonal-noise characteristics and periodic flow structure around NACA0018 airfoil

Energy Technology Data Exchange (ETDEWEB)

Nakano, T.; Fujisawa, N. [Niigata University, Department Mechanical Engineering, Niigata (Japan); Lee, S. [Inha University, Department Mechanical Engineering, Incheon (Korea)

2006-03-15

The characteristics of tonal noise and the variations of flow structure around NACA0018 airfoil in a uniform flow are studied by means of simultaneous measurement of noise and velocity field by particle-image velocimetry to understand the generation mechanism of tonal noise. Measurements are made on the noise characteristics, the phase-averaged velocity field with respect to the noise signal, and the cross-correlation contour of velocity fluctuations and noise signal. These experimental results indicate that the tonal noise is generated from the periodic vortex structure on the pressure surface of the airfoil near the trailing edge of the airfoil. It is found that the vortex structure is highly correlated with the noise signal, which indicates the presence of noise-source distribution on the pressure surface. The vorticity distribution on the pressure surface breaks down near the trailing edge of the airfoil and forms a staggered vortex street in the wake of the airfoil. (orig.)

Predicting tissue-specific expressions based on sequence characteristics

KAUST Repository

Paik, Hyojung; Ryu, Tae Woo; Heo, Hyoungsam; Seo, Seungwon; Lee, Doheon; Hur, Cheolgoo

2011-01-01

In multicellular organisms, including humans, understanding expression specificity at the tissue level is essential for interpreting protein function, such as tissue differentiation. We developed a prediction approach via generated sequence features from overrepresented patterns in housekeeping (HK) and tissue-specific (TS) genes to classify TS expression in humans. Using TS domains and transcriptional factor binding sites (TFBSs), sequence characteristics were used as indices of expressed tissues in a Random Forest algorithm by scoring exclusive patterns considering the biological intuition; TFBSs regulate gene expression, and the domains reflect the functional specificity of a TS gene. Our proposed approach displayed better performance than previous attempts and was validated using computational and experimental methods.

Predicting tissue-specific expressions based on sequence characteristics

KAUST Repository

Paik, Hyojung

2011-04-30

In multicellular organisms, including humans, understanding expression specificity at the tissue level is essential for interpreting protein function, such as tissue differentiation. We developed a prediction approach via generated sequence features from overrepresented patterns in housekeeping (HK) and tissue-specific (TS) genes to classify TS expression in humans. Using TS domains and transcriptional factor binding sites (TFBSs), sequence characteristics were used as indices of expressed tissues in a Random Forest algorithm by scoring exclusive patterns considering the biological intuition; TFBSs regulate gene expression, and the domains reflect the functional specificity of a TS gene. Our proposed approach displayed better performance than previous attempts and was validated using computational and experimental methods.

Self-correcting random number generator

Science.gov (United States)

Humble, Travis S.; Pooser, Raphael C.

2016-09-06

A system and method for generating random numbers. The system may include a random number generator (RNG), such as a quantum random number generator (QRNG) configured to self-correct or adapt in order to substantially achieve randomness from the output of the RNG. By adapting, the RNG may generate a random number that may be considered random regardless of whether the random number itself is tested as such. As an example, the RNG may include components to monitor one or more characteristics of the RNG during operation, and may use the monitored characteristics as a basis for adapting, or self-correcting, to provide a random number according to one or more performance criteria.

Stability of response characteristics of a Delphi panel: application of bootstrap data expansion

Directory of Open Access Journals (Sweden)

Cole Bryan R

2005-12-01

Full Text Available Abstract Background Delphi surveys with panels of experts in a particular area of interest have been widely utilized in the fields of clinical medicine, nursing practice, medical education and healthcare services. Despite this wide applicability of the Delphi methodology, there is no clear identification of what constitutes a sufficient number of Delphi survey participants to ensure stability of results. Methods The study analyzed the response characteristics from the first round of a Delphi survey conducted with 23 experts in healthcare quality and patient safety. The panel members had similar training and subject matter understanding of the Malcolm Baldrige Criteria for Performance Excellence in Healthcare. The raw data from the first round sampling, which usually contains the largest diversity of responses, were augmented via bootstrap sampling to obtain computer-generated results for two larger samples obtained by sampling with replacement. Response characteristics (mean, trimmed mean, standard deviation and 95% confidence intervals for 54 survey items were compared for the responses of the 23 actual study participants and two computer-generated samples of 1000 and 2000 resampling iterations. Results The results from this study indicate that the response characteristics of a small expert panel in a well-defined knowledge area are stable in light of augmented sampling. Conclusion Panels of similarly trained experts (who possess a general understanding in the field of interest provide effective and reliable utilization of a small sample from a limited number of experts in a field of study to develop reliable criteria that inform judgment and support effective decision-making.

A framework for understanding the concerns of ecological designers

International Nuclear Information System (INIS)

DeKay, M.

1992-01-01

This paper creates a theoretical framework of analysis for understanding the concerns and methods of ecological designers. Various definitions of ecological design are reviewed to show its basis in natural ecological systems, either as analog or as context, and its purpose as creating sustainability. Ecological design methods are categorized as conceptual, factual, or integrative. The characteristics and definitions of these methods are explained and several practitioners and theorists classified. Lyle's concept of ecosystematic order is used to show the basis of methods in either a building architecture or a landscape architecture perspective. A matrix is generated and applied to a representative of each category, showing the concerns of each in terms of the integration of human and natural ecosystem structure, function, and location

Too close and too rigid: applying the Circumplex Model of Family Systems to first-generation family firms.

Science.gov (United States)

Michael-Tsabari, Nava; Lavee, Yoav

2012-06-01

Despite growing research interest in family businesses, little is known about the characteristics of the families engaging in them. The present paper uses Olson's (Journal of Psychotherapy & the Family, 1988, 4(12), 7-49; Journal of Family Therapy, 2000, 22, 144-167) Circumplex Model of Marital and Family Systems to look at first-generation family firms. We describe existing typologies of family businesses and discuss similarities between the characteristics of first-generation family firms and the rigidly enmeshed family type described in the Circumplex Model. The Steinberg family business (Gibbon & Hadekel (1990) Steinberg: The breakup of a family empire. ON, Canada: MacMillan) serves to illustrate the difficulties of rigidly enmeshed first-generation family firms. Implications for understanding troubled family businesses are discussed together with guidelines for the assessment of a family business in crisis and for intervention: enhancing open communication; allowing for more flexible leadership style, roles, and rules; and maintaining a balance between togetherness and separateness. © 2012 American Association for Marriage and Family Therapy.

Characteristics Testing of the ECT Bobbin Probe for Steam Generator Tube Inspection of Nuclear Power Plant

International Nuclear Information System (INIS)

Nam, Min Woo; Lee, Hee Jong; Cho, Chan hee; Yoo, Hyun Joo

2010-01-01

The steam generator management program(SGMP) has recently defined the procedures for the qualification of eddy current hardware and technique. These procedures provide two basic methods for qualification. The first way is to qualify the equipment or the probe by using the flaw mechanism and method of the pulled tubes from the heat exchangers or the artificial flawed tubes. The second way is to verify the equivalency with the characteristics of the qualified equipment or probe. In this case, the qualified equipment or probe may be modified to substitute or replace instruments or probes without re-qualification provided that the range of essential variables defined in the examination technique specification sheet are met. This study is to describe the result of the comparative performance evaluation of bobbin coil eddy current probes manufactured by KEPCO Research Institute and probes manufactured by a foreign manufacturer. As a result of this study, although there were minor differences between the two kinds of probes, it was evaluated that the two kinds of probes were almost identical in the significant performance characteristics described in the KEPCO Research Institute guideline

Characteristics Testing of the ECT Bobbin Probe for Steam Generator Tube Inspection of Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Nam, Min Woo; Lee, Hee Jong; Cho, Chan hee; Yoo, Hyun Joo [KEPCO, Daejeon (Korea, Republic of)

2010-08-15

The steam generator management program(SGMP) has recently defined the procedures for the qualification of eddy current hardware and technique. These procedures provide two basic methods for qualification. The first way is to qualify the equipment or the probe by using the flaw mechanism and method of the pulled tubes from the heat exchangers or the artificial flawed tubes. The second way is to verify the equivalency with the characteristics of the qualified equipment or probe. In this case, the qualified equipment or probe may be modified to substitute or replace instruments or probes without re-qualification provided that the range of essential variables defined in the examination technique specification sheet are met. This study is to describe the result of the comparative performance evaluation of bobbin coil eddy current probes manufactured by KEPCO Research Institute and probes manufactured by a foreign manufacturer. As a result of this study, although there were minor differences between the two kinds of probes, it was evaluated that the two kinds of probes were almost identical in the significant performance characteristics described in the KEPCO Research Institute guideline

Investigation on the characteristics of liquid wastes depending on their generation sources and study on optimum treatment method

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Guk; Kim, Dong Chan; Shin, Dae Hyun; Son, Seung Geun; Roh, Nam Sun; Woo, Je Kyung [Korea Inst. of Energy Research, Taejon (Korea, Republic of)

1995-12-01

The major research contents conducted this year are as follows: (1) environmental regulation with respect to the treatment of the liquid waste in the U.S.A., (2) the present status of the generation and treatment of liquid wastes for large producers(>1,000 ton/year), (3) analysis for heating value element, heavy metal content, halogenated species on collected samples, (4) investigation on estimation method of energy recovery rate from liquid waste, (5) design of a lab. scale reactor which could be capable of conducting thermal decomposition test with small quantity of sample. In this study, present status of liquid waste generation and treatment is investigated, and thermal decomposition characteristics are studied using a lab. scale thermal reactor. The purpose of this research is to divide liquid waste into groups and to present best treatment method for their each group. (author). 24 refs., 21 figs., 23 tabs.

Characteristics of outage radiation fields around various reactor components

International Nuclear Information System (INIS)

Verzilov, Y.; Husain, A.; Corbin, G.

2008-01-01

Full text: Activity monitoring surveys, consisting of gamma spectroscopy and dose rate measurements, of various CANDU station components such as the reactor face, feeder cabinet, steam generators and moderator heat exchangers are often performed during shutdown in order to trend the transport of activity around the primary heat transport and moderator systems. Recently, the increased dose expenditure for work such as feeder inspection and replacement in the reactor vault has also spurred interest in improved characterization of the reactor face fields to facilitate better ALARA decision making and hence a reduction in future dose expenditures. At present, planning for reactor face work is hampered by insufficient understanding of the relative contribution of the various components to the overall dose. In addition to the increased dose expenditure for work at the reactor face, maintenance work associated with horizontal flux detectors and liquid injection systems has also resulted in elevated dose expenditures. For instance at Darlington, radiation fields in the vicinity of horizontal flux detectors (HFD) and Liquid Injection Shutdown System (LISS) nozzle bellows are trending upwards with present contact fields being in the range 16-70 rem/h and working distance fields being in the range 100-500 mrem/h. This paper presents findings based on work currently being funded by the CANDU Owners Group. Measurements were performed at Ontario Power Generation's Pickering and Darlington nuclear stations. Specifically, the following are addressed: Characteristics of Reactor Vault Fields; Characteristics of Steam Generator Fields; Characteristics of Moderator Heat Exchanger Fields. Measurements in the reactor vault were performed at the reactor face, along the length of end fittings, along the length of feeders, at the bleed condenser and at the HFD and LISS nozzle bellows. Steam generator fields were characterized at various elevations above the tube sheet, with and without the

Generations and Gender Survey (GGS: Towards a Better Understanding of Relationships and Processes in the Life Course

Directory of Open Access Journals (Sweden)

Zsolt Spéder

2007-11-01

Full Text Available The Generations and Gender Survey (GGS is one of the two pillars of the Generations and Gender Programme designed to improve understanding of demographic and social development and of the factors that influence these developments. This article describes how the theoretical perspectives applied in the survey, the survey design and the questionnaire are related to this objective. The key features of the survey include panel design, multidisciplinarity, comparability, context-sensitivity, inter-generational and gender relationships. The survey applies the life course approach, focussing on the processes of childbearing, partnership dynamics, home leaving, and retiring. The selection of topics for data collection mainly follows the criterion of theoretically grounded relevance to explaining one or more of the mentioned processes. A large portion of the survey deals with economic aspects of life, such as economic activity, income, and economic well-being; a comparably large section is devoted to values and attitudes. Other domains covered by the survey include gender relationships, household composition and housing, residential mobility, social networks and private transfers, education, health, and public transfers. The third chapter of the article describes the motivations for their inclusion. The GGS questionnaire is designed for a face-to-face interview. It includes the core that each participating country needs to implement in full, and four optional sub-modules on nationality and ethnicity, on previous partners, on intentions of breaking up, and on housing, respectively. The participating countries are encouraged to include also the optional sub-modules to facilitate comparative research on these topics.

Self-shielding characteristics of aqueous self-cooled blankets for next generation fusion devices

International Nuclear Information System (INIS)

Pelloni, S.; Cheng, E.T.; Embrechts, M.J.

1987-11-01

The present study examines self-shielding characteristics for two aqueous self-cooled tritium producing driver blankets for next generation fusion devices. The aqueous Self-Cooled Blanket concept (ASCB) is a very simple blanket concept that relies on just structural material and coolant. Lithium compounds are dissolved in water to provide for tritium production. An ASCB driver blanket would provide a low technology and low temperature environment for blanket test modules in a next generation fusion reactor. The primary functions of such a blanket would be shielding, energy removal and tritium production. One driver blanket considered in this study concept relates to the one proposed for the Next European Torus (NET), while the second concept is indicative for the inboard shield design for the Engineering Test Reactor proposed by the USA (TIBER II/ETR). The driver blanket for NET is based on stainless steel for the structural material and aqueous solution, while the inboard shielding blanket for TIBER II/ETR is based on a tungsten/aqueous solution combination. The purpose of this study is to investigate self-shielding and heterogeneity effects in aqueous self-cooled blankets. It is found that no significant gains in tritium breeding can be achieved in the stainless steel blanket if spatial and energy self-shielding effects are considered, and the heterogeneity effects are also insignificant. The tungsten blanket shows a 5 percent increase in tritium production in the shielding blanket when energy and spatial self-shielding effects are accounted for. However, the tungsten blanket shows a drastic increase in the tritium breeding ratio due to heterogeneity effects. (author) 17 refs., 9 figs., 9 tabs

Characteristics of SnO2-based 68Ge/68Ga generator and aspects of radiolabelling DOTA-peptides.

Science.gov (United States)

de Blois, Erik; Sze Chan, Ho; Naidoo, Clive; Prince, Deidre; Krenning, Eric P; Breeman, Wouter A P

2011-02-01

PET scintigraphy with (68)Ga-labelled analogs is of increasing interest in Nuclear Medicine and performed all over the world. Here we report the characteristics of the eluate of SnO(2)-based (68)Ge/(68)Ga generators prepared by iThemba LABS (Somerset West, South Africa). Three purification and concentration techniques of the eluate for labelling DOTA-TATE and concordant SPE purifications were investigated. Characteristics of 4 SnO(2)-based generators (range 0.4-1 GBq (68)Ga in the eluate) and several concentration techniques of the eluate (HCl) were evaluated. The elution profiles of SnO(2)-based (68)Ge/(68)Ga generators were monitored, while [HCl] of the eluens was varied from 0.3-1.0 M. Metal ions and sterility of the eluate were determined by ICP. Fractionated elution and concentration of the (68)Ga eluate were performed using anion and cation exchange. Concentrated (68)Ga eluate, using all three concentration techniques, was used for labelling of DOTA-TATE. (68)Ga-DOTA-TATE-containing solution was purified and RNP increased by SPE, therefore also 11 commercially available SPE columns were investigated. The amount of elutable (68)Ga activity varies when the concentration of the eluens, HCl, was varied, while (68)Ge activity remains virtually constant. SnO(2)-based (68)Ge/(68)Ga generator elutes at 0.6 M HCl >100% of the (68)Ga activity at calibration time and ±75% after 300 days. Eluate at discharge was sterile and Endotoxins were 80%). Highest desorption for cation purification was obtained using a solution containing 90% acetone at increasing molarity of HCl, resulted in a (68)Ga desorption of 68±8%. With all (68)Ge/(68)Ga generators and for all 3 purification methods a SA up to 50 MBq/nmol with >95% incorporation (ITLC) and RCP (radiochemical purity) by HPLC ±90% could be achieved. Purification and concentration of the eluate with anion exchange has the benefit of more elutable (68)Ga with 1 M HCl as eluens. The additional washing step of the anion column

New Generation Discovery: A Systematic View for Its Development, Issues and Future

KAUST Repository

Yu, Yi

2012-11-01

Collecting, storing, discovering, and locating are integral parts of the composition of the library. To fully utilize the library and achieve its ultimate value, the construction and production of discovery has always been a central part of the library’s practice and identity. That is the reason why the new generation (also called the next-generation discovery) discovery gets such striking effect since it came into library automation arena. However, when we talk about the new generation of discovery in the library domain, we should see it in the entirety of the library as one of its organic parts and consider its progress along with the evolution of the whole library world. We should have a deeper understanding about its relationship and interaction with the internet, the rapidly changing digital environment, and the elements and the chain of library services. To address above issues, this paper overviews the different versions of the definition for the new generation discovery by combining our own understanding. The paper also gives our own description for its properties and characteristics. The paper points out what challenges, which extends the technology domain to commercial interests and business strategy, are faced by the discovery applications, and how library and library professionals deal with those challenges. Finally, the paper elaborates on the promise brought by the new discovery development and what the next exploration might be for its future.

Laser light absorption and harmonic generation due to self-generated magnetic fields

International Nuclear Information System (INIS)

Kruer, W.L.; Estabrook, K.G.

1977-01-01

It is shown that self-generated magnetic fields can play a significant role in laser light absorption. Even normally incident light will then be resonantly absorbed. Computer simulations and theoretical estimates for this absorption and the concomitant harmonic generation are given for parameters characteristic of some recent experiments

Research on Shaft Subsynchronous Oscillation Characteristics of Parallel Generators and SSDC Application in Mitigating SSO of Multi-Generators

Directory of Open Access Journals (Sweden)

Shen Wang

2015-02-01

Full Text Available Subsynchronous oscillation (SSO of generators caused by high voltage direct current (HVDC systems can be solved by applying supplemental subsynchronous damping controller (SSDC. SSDC application in mitigating SSO of single-generator systems has been studied intensively. This paper focuses on SSDC application in mitigating SSO of multi-generator systems. The phase relationship of the speed signals of the generators under their common mechanical natural frequencies is a key consideration in SSDC design. The paper studies in detail the phase relationship of the speed signals of two generators in parallel under their shared mechanical natural frequency, revealing regardless of whether the two generators are identical or not, there always exists a common-mode and an anti-mode under their common natural frequency, and the phase relationship of the speed signals of the generators depends on the extent to which the anti-mode is stimulated. The paper further demonstrates that to guarantee the effectiveness of SSDC, the anti-phase mode component of its input signal should be eliminated. Based on the above analysis, the paper introduces the design process of SSDC for multi-generator systems and verifies its effectiveness through simulation in Power Systems Computer Aided Design/Electromagnetic Transients including Direct Current (PSCAD/EMTDC.

Study of recovery characteristics of 2nd generation HTS tapes with different stabilizers for resistive type superconducting fault current limiters

International Nuclear Information System (INIS)

Sheng, Jie; Zeng, Weina; Ma, Jun; Yao, Zhihao; Li, Zhuyong; Jin, Zhijian; Hong, Zhiyong

2016-01-01

Highlights: • Three methods of measuring the recovery time of HTS tapes are compared. • Four tapes with different stabilizers were tested to compare their recovery characteristics. • The HTS tapes with thinner stabilizers have better recovery characteristics. • Encapsulation makes the recovery characteristics of HTS tapes worse. • The results can be reference of the re-reclosed operation time interval. - Abstract: The resistive type superconducting fault current limiter (SFCL) is one of the most important superconducting power applications nowadays. As known, this type of SFCL is settled directly in the power transmission line. When a short fault happens, the temperature of the superconductors in the SFCL will increase sharply due to the huge generated heat. This means the superconductors need time to recover the superconducting properties and be ready for the next short fault. So the recovery characteristics become one of the most crucial features of the resistive type SFCL. In this paper, several different kinds of measuring methods are presented to calculate the recovery time of the HTS tapes, and comparison of these methods is also carried out by a standard test. On basis of this, samples with different kinds of stabilizers are used to explore the influence of stabilizer on their recovery characteristics. In addition, the influence of the encapsulation technology is also discussed in this paper.

Is the "First-Generation Student" Term Useful for Understanding Inequality? the Role of Intersectionality in Illuminating the Implications of an Accepted--Yet Unchallenged--Term

Science.gov (United States)

Nguyen, Thai-Huy; Nguyen, Bach Mai Dolly

2018-01-01

First-generation students (FGSs) have received a great deal of attention in education research, practice, and policy. The difficulty of understanding and subsequently addressing the various and persistent configurations of inequality associated with FGSs lies with the complicated yet obscure state of the FGS term itself. Leaving the term…

Development, Beam characterization and chromosomal effectiveness of X-rays of RBC characteristic X-ray generator

International Nuclear Information System (INIS)

Endo, Satoru; Hoshi, Masaharu; Takada, Jun; Takatsuji, Toshihiro; Ejima, Yosuke; Saigusa, Shin; Tachibana, Akira; Sasaki, Masao S.

2006-01-01

A characteristic hot-filament type X-ray generator was constructed for irradiation of cultured cells. The source provides copper K, iron K, chromium K, molybdenum L, aluminium K and carbon K shell characteristic X-rays. When cultured mouse m5S cells were irradiated and frequencies of dicentrics were fitted to a linear-quadratic model, Y=αD+βD 2 , the chromosomal effectiveness was not a simple function of photon energy. The α-terms increased with the decrease of the photon energy and then decreased with further decrease of the energy with an inflection point at around 10 keV. The β-terms stayed constant for the photon energy down to 10 keV and then increased with further decrease of energy. Below 10 keV, the relative biological effectiveness (RBE) at low doses was proportional to the photon energy, which contrasted to that for high energy X- or γ-rays where the RBE was inversely related with the photon energy. The reversion of the energy dependency occurred at around 1-2 Gy, where the RBE of soft X-rays was insensitive to X-ray energy. The reversion of energy-RBE relation at a moderate dose may shed light on the controversy on energy dependency of RBE of ultrasoft X-rays in cell survival experiments. (author)

Navy Advertising: Targeting Generation Z

Science.gov (United States)

2015-12-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA MBA PROFESSIONAL REPORT NAVY ADVERTISING : TARGETING GENERATION Z December......study recommends improvements for Navy advertising efficiency by examining characteristics of recruits defined as Generation Z. Data gathered from five

Payment Instrument Characteristics

DEFF Research Database (Denmark)

Holst, Jacques; Kjeldsen, Martin; Hedman, Jonas

2015-01-01

Over the last decade, we have witnessed payment innovations that fundamentally have changed the ways we pay. Payment innovations, such as mobile payments and on-line banking, include characteristics or features that are essential to understand if we want to know how and why payers choose among...... payment innovations. Using the Repertory Grid technique to explore 15 payers’ perception of six payment instruments, including coins, banknotes, debit cards, credit cards, mobile payments, and on-line banking, we identify 16 payment characteristics. The characteristics aggregate seventy-six unique...

Real-ear acoustical characteristics of impulse sound generated by golf drivers and the estimated risk to hearing: a cross-sectional study.

Science.gov (United States)

Zhao, Fei; Bardsley, Barry

2014-01-21

This study investigated real-ear acoustical characteristics in terms of the sound pressure levels (SPLs) and frequency responses in situ generated from golf club drivers at impact with a golf ball. The risk of hearing loss caused by hitting a basket of golf balls using various drivers was then estimated. Cross-sectional study. The three driver clubs were chosen on the basis of reflection of the commonality and modern technology of the clubs. The participants were asked to choose the clubs in a random order and hit six two-piece range golf balls with each club. The experiment was carried out at a golf driving range in South Wales, UK. 19 male amateur golfers volunteered to take part in the study, with an age range of 19-54 years. The frequency responses and peak SPLs in situ of the transient sound generated from the club at impact were recorded bilaterally and simultaneously using the GN Otometric Freefit wireless real-ear measurement system. A swing speed radar system was also used to investigate the relationship between noise level and swing speed. Different clubs generated significantly different real-ear acoustical characteristics in terms of SPL and frequency responses. However, they did not differ significantly between the ears. No significant correlation was found between the swing speed and noise intensity. On the basis of the SPLs measured in the present study, the percentage of daily noise exposure for hitting a basket of golf balls using the drivers described above was less than 2%. The immediate danger of noise-induced hearing loss for amateur golfers is quite unlikely. However, it may be dangerous to hearing if the noise level generated by the golf clubs exceeded 116 dBA.

Simple and Realistic Data Generation

DEFF Research Database (Denmark)

Pedersen, Kenneth Houkjær; Torp, Kristian; Wind, Rico

2006-01-01

This paper presents a generic, DBMS independent, and highly extensible relational data generation tool. The tool can efficiently generate realistic test data for OLTP, OLAP, and data streaming applications. The tool uses a graph model to direct the data generation. This model makes it very simple...... to generate data even for large database schemas with complex inter- and intra table relationships. The model also makes it possible to generate data with very accurate characteristics....

Thermoeconomic diagnosis and entropy generation paradox

DEFF Research Database (Denmark)

Sigthorsson, Oskar; Ommen, Torben Schmidt; Elmegaard, Brian

2017-01-01

In the entropy generation paradox, the entropy generation number, as a function of heat exchanger effectiveness, counter-intuitively approaches zero in two limits symmetrically from a single maximum. In thermoeconomic diagnosis, namely in the characteristic curve method, the exergy destruction...... to the entropy generation paradox, as a decreased heat exchanger effectiveness (as in the case of an operation anomaly in the component) can counter-intuitively result in decreased exergy destruction rate of the component. Therefore, along with an improper selection of independent variables, the heat exchanger...... increases in case of an operation anomaly in a component. The normalised exergy destruction rate as the dependent variable therefore resolves the relation of the characteristic curve method with the entropy generation paradox....

Work Practice Characteristics

DEFF Research Database (Denmark)

Pors, Jens Kaaber; Simonsen, Jesper

2003-01-01

and work practice. To understand these issues a framework of characteristics is identified and termed work practice characteristics to describe important aspects of the hybrid configuration of groupware and situated work practices. Drawing on concepts and work practice studies in the field of computer...... investigation of how groupware is employed to support new ways of working in a large European financial organisation are analysed to illustrate situations with high and low integration of groupware. The framework of work practice characteristics is discussed in the light of these findings and implications...

Managing 'Generation Y' occupational therapists: optimising their potential.

Science.gov (United States)

Hills, Caroline; Ryan, Susan; Warren-Forward, Helen; Smith, Derek R

2013-08-01

'Generation Y' is a descriptor of those therapists born between 1982 and 2000. According to generational theory, each generation have unique characteristics due to the social and historical factors they have experienced during their formative years. Occupational therapy educators have reported on 'Generation Y' characteristics observed in occupational therapy students. This study aimed to investigate if managers considered there was a 'Generation Y' therapist and their observed characteristics in practice, as well as successful management strategies used to maximise their potential in the workplace. A hard copy survey based on the 'Generation Y' literature was sent to all managers listed on an Australian University database. Almost all respondents considered there was a 'Generation Y' therapist. Overall, managers reported characteristics of this staff group as being hard working, confident with technology, needing positive feedback and demanding professional development opportunities. Managers also reported that this group may be a challenge to retain in work positions. Managers also viewed 'Generation Y' staff as a positive energy and considered that in the future they will be of benefit to the profession. While there may be generational differences between therapists in the workplace, inclusive management styles may be the most appropriate management approach. Career guidance, facilitating creativity, increasing work responsibility and integrating new technologies like social networking into practice may be appropriate strategies for this staff group, to facilitate both their professional development and to retain them in the profession. © 2013 Occupational Therapy Australia.

Generational Theory: Implications for Recruiting the Millennials

National Research Council Canada - National Science Library

Drago, James P

2006-01-01

.... Using generational theory it will review the characteristics beliefs values and attitudes of Generation X the Baby Boomers and the Millennial generation the target audience of the Army's current recruiting efforts...

Generation Y Online Buying Patterns

Directory of Open Access Journals (Sweden)

Katija Vojvodić

2015-12-01

Full Text Available The advantages of electronic retailing can, among other things, result in uncontrolled buying by online consumers, i.e. in extreme buying behavior. The main purpose of this paper is to analyze and determine the buying patterns of Generation Y online consumers in order to explore the existence of different types of behavior based on the characteristics of online buying. The paper also aims at exploring the relationship between extracted factors and Generation Y consumers’ buying intentions. Empirical research was conducted on a sample of 515 consumers in the Dubrovnik-Neretva County. Based on the factor analysis, research results indicate that Generation Y online consumers are influenced by three factors: compulsivity, impulsivity, and functionality. The analysis of variance reveals that significant differences exist between the extracted factors and Generation Y’s online buying characteristics. In addition, correlation analysis shows a statistically significant correlation between the extracted factors and Generation Y’s buying intentions.

Travel patterns and characteristics of foreign-born sub-population in New York state

Energy Technology Data Exchange (ETDEWEB)

Chin, Shih-Miao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hwang, Ho-Ling [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Reuscher, Tim [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Daniel W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-10-01

According to the 2010 Census, over 22% of total New York State (NYS) residents were foreign-born and over one in three persons living in New York City (NYC) were foreign-born. Foreign-born and their dependents impact local economies in many different ways, including purchasing power, transportation service needs, business sales and receipts generated, and workforce. To allow better policy decision making and program planning of transportation developments and investments in NYS, a clear understanding of the foreign-born population’s travel characteristics and behaviors, as well as their unique transportation service needs, are necessary. This report documents the characteristics of the foreign-born population and identified differences in travel behaviors and mobility issues between foreign-born residents of NYS and their U.S.-born counterparts.

Regulation characteristics of oxide generation and formaldehyde removal by using volume DBD reactor

Science.gov (United States)

Bingyan, CHEN; Xiangxiang, GAO; Ke, CHEN; Changyu, LIU; Qinshu, LI; Wei, SU; Yongfeng, JIANG; Xiang, HE; Changping, ZHU; Juntao, FEI

2018-02-01

Discharge plasmas in air can be accompanied by ultraviolet (UV) radiation and electron impact, which can produce large numbers of reactive species such as hydroxyl radical (OH·), oxygen radical (O·), ozone (O3), and nitrogen oxides (NO x ), etc. The composition and dosage of reactive species usually play an important role in the case of volatile organic compounds (VOCs) treatment with the discharge plasmas. In this paper, we propose a volume discharge setup used to purify formaldehyde in air, which is configured by a plate-to-plate dielectric barrier discharge (DBD) channel and excited by an AC high voltage source. The results show that the relative spectral-intensity from DBD cell without formaldehyde is stronger than the case with formaldehyde. The energy efficiency ratios (EERs) of both oxides yield and formaldehyde removal can be regulated by the gas flow velocity in DBD channel, and the most desirable processing effect is the gas flow velocity within the range from 2.50 to 3.33 m s-1. Moreover, the EERs of both the generated dosages of oxides (O3 and NO2) and the amount of removed formaldehyde can also be regulated by both of the applied voltage and power density loaded on the DBD cell. Additionally, the EERs of both oxides generation and formaldehyde removal present as a function of normal distribution with increasing the applied power density, and the peak of the function is appeared in the range from 273.5 to 400.0 W l-1. This work clearly demonstrates the regulation characteristic of both the formaldehyde removal and oxides yield by using volume DBD, and it is helpful in the applications of VOCs removal by using discharge plasma.

A 12 kV, 1 kHz, Pulse Generator for Breakdown Studies of Samples for CLIC RF Accelerating Structures

CERN Document Server

Soares, R H; Kovermann, J; Calatroni, S; Wuensch, W

2012-01-01

Compact Linear Collider (CLIC) RF structures must be capable of sustaining high surface electric fields, in excess of 200 MV/m, with a breakdown (BD) rate below 3×10-7 breakdowns/pulse/m. Achieving such a low rate requires a detailed understanding of all the steps involved in the mechanism of breakdown. One of the fundamental studies is to investigate the statistical characteristics of the BD rate phenomenon at very low values to understand the origin of an observed dependency of the surface electric field raised to the power of 30. To acquire sufficient BD data, in a reasonable period of time, a high repetition rate pulse generator is required for an existing d.c. spark system at CERN. Following BD of the material sample the pulse generator must deliver a current pulse of several 10’s of Amperes for ~2 μs. A high repetition rate pulse generator has been designed, built and tested; this utilizes pulse forming line technology and employs MOSFET switches. This paper describes the design of the pulse generat...

Intelligent information data base of flow boiling characteristics in once-through steam generator for integrated type marine water reactor

International Nuclear Information System (INIS)

Inasaka, Fujio; Nariai, Hideki

1998-01-01

Valuable experimental knowledge with flow boiling characteristics of the helical-coil type once-through steam generator was converted into an intelligent information data base program. The program was created as a windows application using the Visual Basic. Main functions of the program are as follows: (1) steady state flow boiling analysis of any helical-coil type once-through steam generator, (2) analysis and comparison with the experimental data, (3) reference and graph display of the steady state experimental data, (4) reference of the flow instability experimental data and display of the instability threshold correlated by each parameter, (5) summary of the experimental apparatus. (6) menu bar such as a help and print. In the steady state analysis, the region lengths of subcooled boiling, saturated boiling, and super-heating, and the temperature and pressure distributions etc. for secondary water calculated. Steady state analysis results agreed well with the experimental data, with the exception of the pressure drop at high mass velocity. The program will be useful for the design of not only the future integrated type marine water reactor but also the small sized water reactor with helical-coil type steam generator

A three-lead, programmable, and microcontroller-based electrocardiogram generator with frequency domain characteristics of heart rate variability.

Science.gov (United States)

Wei, Ying-Chieh; Wei, Ying-Yu; Chang, Kai-Hsiung; Young, Ming-Shing

2012-04-01

The objective of this study is to design and develop a programmable electrocardiogram (ECG) generator with frequency domain characteristics of heart rate variability (HRV) which can be used to test the efficiency of ECG algorithms and to calibrate and maintain ECG equipment. We simplified and modified the three coupled ordinary differential equations in McSharry's model to a single differential equation to obtain the ECG signal. This system not only allows the signal amplitude, heart rate, QRS-complex slopes, and P- and T-wave position parameters to be adjusted, but can also be used to adjust the very low frequency, low frequency, and high frequency components of HRV frequency domain characteristics. The system can be tuned to function with HRV or not. When the HRV function is on, the average heart rate can be set to a value ranging from 20 to 122 beats per minute (BPM) with an adjustable variation of 1 BPM. When the HRV function is off, the heart rate can be set to a value ranging from 20 to 139 BPM with an adjustable variation of 1 BPM. The amplitude of the ECG signal can be set from 0.0 to 330 mV at a resolution of 0.005 mV. These parameters can be adjusted either via input through a keyboard or through a graphical user interface (GUI) control panel that was developed using LABVIEW. The GUI control panel depicts a preview of the ECG signal such that the user can adjust the parameters to establish a desired ECG morphology. A complete set of parameters can be stored in the flash memory of the system via a USB 2.0 interface. Our system can generate three different types of synthetic ECG signals for testing the efficiency of an ECG algorithm or calibrating and maintaining ECG equipment. © 2012 American Institute of Physics

Welcome to the iGeneration!

Science.gov (United States)

Rosen, Larry

2010-01-01

Defining and understanding a generation of Americans has always been difficult until years after the generation ends. Although there is universal agreement on the Baby Boomer generation (1946-1964) and most people agree that Generation X started in 1965 and ended around 1979, after that it gets murky. In his research, the author believes that the…

Thermoelectric power generator for variable thermal power source

Science.gov (United States)

Bell, Lon E; Crane, Douglas Todd

2015-04-14

Traditional power generation systems using thermoelectric power generators are designed to operate most efficiently for a single operating condition. The present invention provides a power generation system in which the characteristics of the thermoelectrics, the flow of the thermal power, and the operational characteristics of the power generator are monitored and controlled such that higher operation efficiencies and/or higher output powers can be maintained with variably thermal power input. Such a system is particularly beneficial in variable thermal power source systems, such as recovering power from the waste heat generated in the exhaust of combustion engines.

Computationally-generated nuclear forensic characteristics of early production reactors with an emphasis on sensitivity and uncertainty

International Nuclear Information System (INIS)

Redd, Evan M.; Sjoden, Glenn; Erickson, Anna

2017-01-01

Highlights: •X-10 reactor is used as a case study for nuclear forensic signatures. •S/U analysis is conducted to derive statistically relevant markers. •Computationally-generated signatures aid with proliferation pathway identification. •Highest uncertainty in total plutonium production originates from 238 Pu and 242 Pu. -- Abstract: With nuclear technology and analysis advancements, site access restrictions, and ban on nuclear testing, computationally-generated nuclear forensic signatures are becoming more important in gaining knowledge to a reclusive country’s weapon material production capabilities. In particular, graphite-moderated reactors provide an appropriate case study for isotopics relevant in Pu production in a clandestine nuclear program due to the ease of design and low thermal output. We study the production characteristics of the X-10 reactor with a goal to develop statistically-relevant nuclear forensic signatures from early Pu production. In X-10 reactor, a flat flux gradient and low burnup produce exceptionally pure Pu as evident by the 240 Pu/ 239 Pu ratio. However, these design aspects also make determining reactor zone attribution, done with the 242 Pu/ 240 Pu ratio, uncertain. Alternatively, the same ratios produce statistically differentiable results between Manhattan Project and post-Manhattan Project reactor configurations, allowing for attribution conclusions.

Understanding communicative actions : A repetitive TMS study

NARCIS (Netherlands)

Stolk, Arjen; Noordzij, Matthijs Leendert; Volman, Inge; Verhagen, Lennart; Overeem, Sebastiaan; van Elswijk, Gijs; Bloem, Bas; Hagoort, Peter; Toni, Ivan

2014-01-01

Despite the ambiguity inherent in human communication, people are remarkably efficient in establishing mutual understanding. Studying how people communicate in novel settings provides a window into the mechanisms supporting the human competence to rapidly generate and understand novel shared

Understanding communicative actions: A repetitive TMS study

NARCIS (Netherlands)

Stolk, A.; Noordzij, M.L.; Volman, I.A.C.; Verhagen, L.; Overeem, S.; Elswijk, G.A.F. van; Bloem, B.R.; Hagoort, P.; Toni, I.

2014-01-01

Despite the ambiguity inherent in human communication, people are remarkably efficient in establishing mutual understanding. Studying how people communicate in novel settings provides a window into the mechanisms supporting the human competence to rapidly generate and understand novel shared

Understanding communicative actions: A repetitive TMS study

NARCIS (Netherlands)

Stolk, A.; Noordzij, M.L.; Volman, I.A.C.; Verhagen, L.; Overeem, S.; Elswijk, G.A.F. van; Bloem, B.R.; Hagoort, Peter; Toni, I.

2013-01-01

Despite the ambiguity inherent in human communication, people are remarkably efficient in establishing mutual understanding. Studying how people communicate in novel settings provides a window into the mechanisms supporting the human competence to rapidly generate and understand novel shared

Understanding Liking in Relation to Sensory Characteristics, Consumer Concept Associations, Arousal Potential and "Appropriateness for Use" Using Apple Juice as an Application

DEFF Research Database (Denmark)

Stolzenbach, Sandra; Bredie, Wender L P; Christensen, Rune Haubo Bojesen

2016-01-01

potential and appropriateness for use using apple juices as an application. First, a laboratory panel (n=15: F=10, M=5) determined the sensory profile of the apple juices using the methods Partial Napping and Ultra Flash Profiling based on taste and flavor. Next, consumers (n=196: F=136, M=60) evaluated key......It is crucial to understand influential parameters for acquisition of consumer liking to ensure succesful product introduction and competativeness in the marketplace. This article aims to study and understand liking in relation to sensory characteristics, consumer concept associations, arousal...... apple juice parameters. The basic tastes sweet and sour were key properties and played a central role in liking acquisition. Apple juices having a sweet/sour balance were most liked. The importance of balance in sensory properties was underlined by the fact that consumer liking was related...

The effect of using sun tracking systems on the voltage-current characteristics and power generation of flat plate photovoltaics

International Nuclear Information System (INIS)

Abdallah, Salah

2004-01-01

An experimental study was performed to investigate the effect of using different types of sun tracking systems on the voltage-current characteristics and electrical power generation at the output of flat plate photovoltaics (FPPV). Four electromechanical sun tracking systems, two axes, one axis vertical, one axis east-west and one axis north-south, were designed and constructed for the purpose of investigating the effect of tracking on the electrical values, current, voltage and power, according to the different loads (variable resistance). The above mentioned variables were measured at the output of the FPPV and compared with those on a fixed surface. The results indicated that the volt-ampere characteristics on the tracking surfaces were significantly greater than that on a fixed surface. There were increases of electrical power gain up to 43.87%, 37.53%, 34.43% and 15.69% for the two axes, east-west, vertical and north-south tracking, respectively, as compared with the fixed surface inclined 32 deg. to the south in Amman, Jordan

Readability, suitability, and characteristics of asthma action plans: examination of factors that may impair understanding.

Science.gov (United States)

Yin, H Shonna; Gupta, Ruchi S; Tomopoulos, Suzy; Wolf, Michael S; Mendelsohn, Alan L; Antler, Lauren; Sanchez, Dayana C; Lau, Claudia Hillam; Dreyer, Benard P

2013-01-01

Recognition of the complexity of asthma management has led to the development of asthma treatment guidelines that include the recommendation that all pediatric asthma patients receive a written asthma action plan. We assessed the readability, suitability, and characteristics of asthma action plans, elements that contribute to the effectiveness of action plan use, particularly for those with limited literacy. This was a descriptive study of 30 asthma action plans (27 state Department of Health (DOH)-endorsed, 3 national action plans endorsed by 6 states). (1) readability (as assessed by Flesch Reading Ease, Flesch-Kincaid, Gunning Fog, Simple Measure of Gobbledygook, Forcast), (2) suitability (Suitability Assessment of Materials [SAM], adequate: ≥ 0.4; unsuitable: typography (30.0%), learning stimulation/motivation (26.7%), and graphics (13.3%). There were no statistically significant differences between the average grade level or SAM score of state DOH developed action plans and those from or adapted from national organizations. Plans varied with respect to terms used, symptoms included, and recommended actions. Specific improvements in asthma action plans could maximize patient and parent understanding of appropriate asthma management and could particularly benefit individuals with limited literacy skills.

"Go, Go on and Go Higher an' Higher". Second-Generation Turks' Understanding of the Role of Education and Their Struggle through the Dutch School System

Science.gov (United States)

Pasztor, Adel

2010-01-01

With reference to capital theories and rational choice theory, this paper aims to understand how abilities and schooling ambitions are intertwined with social class, gender and ethnicity. By drawing on 16 in-depth interviews carried out with highly educated second-generation Turks in the Netherlands, the paper discusses the resources,…

Y and Z Generations at Workplaces

Directory of Open Access Journals (Sweden)

Bencsik Andrea

2016-09-01

Full Text Available At present, more and more researches deals with the characteristic features of generation Y and generation Z. As it is about the present and future generations, corporate success and the competitive operation are determined by the behav our of these generations in the long-run. Researches justifies that there are significant differences between the two generations despite the similarities. These differences appear rather emphasized in the corporate environment when several questions arise at workplaces in the process of cooperation – especially in the field of knowledge-sharing and knowledge transfer-regarding the characteristics of the two generations. Last year, the authors carried out a quantitative research by questionnaires in order to reveal what the managing of these two generations mean for the managers and also what difficulties occur when the two generations cooperate with each other and with elder generations as well. The main question of the research was how to approach the new generations from the view of HR? Although the research cannot be considered representative (410 respondents participated in the survey, it can give a picture about the examined issues. The hypothesis phrased by the authors was justified according to which of the HR activities have to adapt to the requirements of the new generations upon their appearance.

Radionuclide generators

International Nuclear Information System (INIS)

Lambrecht, R.M.

1983-01-01

The status of radionuclide generators for chemical research and applications related to the life sciences and biomedical research are reviewed. Emphasis is placed upon convenient, efficient and rapid separation of short-lived daughter radionuclides in a chemical form suitable for use without further chemical manipulation. The focus is on the production of the parent, the radiochemistry associated with processing the parent and daughter, the selection and the characteristic separation methods, and yields. Quality control considerations are briefly noted. The scope of this review includes selected references to applications of radionuclide generators in radiopharmaceutical chemistry, and the life sciences, particularly in diagnostic and therapeutic medicine. The 99 Mo-sup(99m)Tc generator was excluded. 202 references are cited. (orig.)

Multi-objective analysis of impacts of distributed generation placement on the operational characteristics of networks for distribution system planning

Energy Technology Data Exchange (ETDEWEB)

Barin, Alexandre; Pozzatti, Luis F.; Canha, Luciane N.; Abaide, Alzenira R. [Federal University of Santa Maria - UFSM, Post-graduation Program of Electric Engineering - PPGEE, Center of Studies of Energy and Environment - CEEMA, Santa Maria, RS (Brazil); Machado, Ricardo Q. [University of Sao Paulo - USP, Sao Carlos, SP (Brazil); Arend, Gustavo [State Electric Energy Company - CEEE-D, Division of Distribution, Porto Alegre, RS (Brazil)

2010-12-15

Recent advances in energy technology generation and new directions in electricity regulation have made distributed generation (DG) more widespread, with consequent significant impacts on the operational characteristics of distribution networks. For this reason, new methods for identifying such impacts are needed, together with research and development of new tools and resources to maintain and facilitate continued expansion towards DG. This paper presents a study aimed at determining appropriate DG sites for distribution systems. The main considerations which determine DG sites are also presented, together with an account of the advantages gained from correct DG placement. The paper intends to define some quantitative and qualitative parameters evaluated by Digsilent registered, GARP3 registered and DSA-GD software. A multi-objective approach based on the Bellman-Zadeh algorithm and fuzzy logic is used to determine appropriate DG sites. The study also aims to find acceptable DG locations both for distribution system feeders, as well as for nodes inside a given feeder. (author)

Understanding tumor anabolism and patient catabolism in cancer-associated cachexia

Science.gov (United States)

Schcolnik-Cabrera, Alejandro; Chávez-Blanco, Alma; Domínguez-Gómez, Guadalupe; Dueñas-González, Alfonso

2017-01-01

Cachexia is a multifactorial paraneoplastic syndrome commonly associated with advanced stages of cancer. Cachexia is responsible for poor responses to antitumoral treatment and death in close to one-third of affected patients. There is still an incomplete understanding of the metabolic dysregulation induced by a tumor that leads to the appearance and persistence of cachexia. Furthermore, cachexia is irreversible, and there are currently no guidelines for its diagnosis or treatments for it. In this review, we aim to discuss the current knowledge about cancer-associated cachexia, starting with generalities about cancer as the generator of this syndrome, then analyzing the characteristics of cachexia at the biochemical and metabolic levels in both the tumor and the patient, and finally discussing current therapeutic approaches to treating cancer-associated cachexia. PMID:28560061

Bugs, butterflies, and spiders: children's understandings about insects

Science.gov (United States)

Shepardson, Daniel P.

2002-06-01

This article explores elementary children's ideas about insects. The study involved 20 children from each grade level, kindergarten through fifth-grade, for a total of 120 children. The data collection procedure was designed to investigate what an insect means to children, through the use of three different tasks: draw and explain, interview about instances, and the formulation of a general rule. Considering children's responses to the three tasks, I found that their ideas about insects reflect understandings based on physical characteristics of size and shape, arthropod characteristics, insect characteristics, human-insect interactions, life habits of insects, feeding habits of insects, and means of locomotion. Children's understandings are juxtaposed to that of a scientific perspective, elucidating implications for curriculum development and instructional practice.

Effect of operation conditions of the drop-on-demand aerosol generator on aerosol characteristics: Pseudo-cinematographic and plasma mass spectrometric studies

Science.gov (United States)

Orlandini v. Niessen, Jan O.; Krone, Karin M.; Bings, Nicolas H.

2014-02-01

The recently presented drop-on-demand (DOD) aerosol generator overcomes some of the drawbacks of pneumatic nebulization, as its aerosol is no longer generated by gas-liquid interaction. In the current study, an advanced imaging technique is presented, based on a CCD camera equipped with magnifying telecentric optics to allow for fast, automated and precise aerosol characterization as well as fundamental studies on the droplet generation processes by means of pseudo-cinematography. The DOD aerosol generator is thoroughly characterized regarding its droplet size distribution, which shows few distinct populations rather than a continuous distribution. Other important figures, such as the Sauter diameter (D3,2) of 22 μm and the span of 0.4 were also determined. Additionally, the influence of the electrical operation conditions of the dosing device on the aerosol generation process is described. The number and volume of the generated droplets were found to be very reproducible and user-variable, e.g. from 17 to 27 μm (D3,2), within a span of 0.07-0.89. The performances of different setups of the DOD as liquid sample introduction system in ICP-MS are correlated to the respective achievable aerosol characteristics and are also compared to the performance of a state-of-the-art μ-flow nebulizer (EnyaMist). The DOD system allowed for improved sensitivity, but slightly elevated signal noise and overall comparable limits of detection. The results are critically discussed and future directions are outlined.

Understanding how orthopaedic surgery practices generate value for healthcare systems.

Science.gov (United States)

Olson, Steven A; Mather, Richard C

2013-06-01

Orthopaedic surgery practices can provide substantial value to healthcare systems. Increasingly, healthcare administrators are speaking of the need for alignment between physicians and healthcare systems. However, physicians often do not understand what healthcare administrators value and therefore have difficulty articulating the value they create in discussions with their hospital or healthcare organization. Many health systems and hospitals use service lines as an organizational structure to track the relevant data and manage the resources associated with a particular type of care, such as musculoskeletal care. Understanding service lines and their management can be useful for orthopaedic surgeons interested in interacting with their hospital systems. We provide an overview of two basic types of value orthopaedic surgeons create for healthcare systems: financial or volume-driven benefits and nonfinancial quality or value-driven patient care benefits. We performed a search of PubMed from 1965 to 2012 using the term "service line." Of the 351 citations identified, 18 citations specifically involved the use of service lines to improve patient care in both nursing and medical journals. A service line is a structure used in healthcare organizations to enable management of a subset of activities or resources in a focused area of patient care delivery. There is not a consistent definition of what resources are managed within a service line from hospital to hospital. Physicians can positively impact patient care through engaging in service line management. There is increasing pressure for healthcare systems and hospitals to partner with orthopaedic surgeons. The peer-reviewed literature demonstrates there are limited resources for physicians to understand the value they create when attempting to negotiate with their hospital or healthcare organization. To effectively negotiate for resources to provide the best care for patients, orthopaedic surgeons need to claim and

Understanding jet noise.

Science.gov (United States)

Karabasov, S A

2010-08-13

Jets are one of the most fascinating topics in fluid mechanics. For aeronautics, turbulent jet-noise modelling is particularly challenging, not only because of the poor understanding of high Reynolds number turbulence, but also because of the extremely low acoustic efficiency of high-speed jets. Turbulent jet-noise models starting from the classical Lighthill acoustic analogy to state-of-the art models were considered. No attempt was made to present any complete overview of jet-noise theories. Instead, the aim was to emphasize the importance of sound generation and mean-flow propagation effects, as well as their interference, for the understanding and prediction of jet noise.

Towards a better understanding of unethical consumer behavior : the influence of individual characteristics, situational circumstances and emotional experiences in consumers' ethical decision-making processes

OpenAIRE

Steenhaut, Sarah

2006-01-01

In sum, we may conclude that – although many questions are still to be resolved – the present dissertation contributes to a better understanding of unethical consumer behavior by further enhancing the theory development of consumers’ ethical decision-making processes by conceiving and testing (1) additional individual characteristics, (2) situational circumstances, and (3) emotional experiences (along with other issue-related influences), and considering the potential mediating and moderating...

Generative Contexts: Generating value between community and educational settings

Directory of Open Access Journals (Sweden)

Dan Lyles

2016-12-01

Full Text Available As educators and researchers, the authors of this paper participated, at different points in time, in a National Science Foundation funded research program to place culturally responsive education into generative justice frameworks. We discovered that the mechanisms to create generative contexts—contexts where value can possibly be returned to the community where the people generating that value live and work—in-school, after-school, and not-school were not uniform and required individual attention and care. One can think of generative contexts as the educational preconditions for generative justice. We aim to show how generative contexts are crucial to understanding a larger theory of generative justice. To do this we provide three examples of generative contexts. First is a generative context in-school, where a technology teacher brought a community hairstylist into her classroom to help teach computer programming through cornrow braiding; a skill relevant to her African American students. Next is a generative context after-school where a student demonstrates soldering skills that she learned from family members. The third is a not-school “E-Waste to Makerspace” workshop where students created garden-technology designs for low-income communities. 

A New Current Control Strategy of Maximizing The Generated Power From a Doubly Fed Induction Generator System

DEFF Research Database (Denmark)

Li, Hui; Chen, Zhe

2006-01-01

Switched reluctance generator (SR Generator) has various desirable features which include simple and solid structure, easiness of maintenance, small moment of rotor inertia and low cost. However, the SR generator has not been put into practical use widely because an optimum design of SR generator...... is consist of half number of switching devices for the AHBC. The operating characteristics of the SR generators were discussed based on FEM analysis and experiments....

Generation of Length Distribution, Length Diagram, Fibrogram, and Statistical Characteristics by Weight of Cotton Blends

Directory of Open Access Journals (Sweden)

B. Azzouz

2007-01-01

Full Text Available The textile fibre mixture as a multicomponent blend of variable fibres imposes regarding the proper method to predict the characteristics of the final blend. The length diagram and the fibrogram of cotton are generated. Then the length distribution, the length diagram, and the fibrogram of a blend of different categories of cotton are determined. The length distributions by weight of five different categories of cotton (Egyptian, USA (Pima, Brazilian, USA (Upland, and Uzbekistani are measured by AFIS. From these distributions, the length distribution, the length diagram, and the fibrogram by weight of four binary blends are expressed. The length parameters of these cotton blends are calculated and their variations are plotted against the mass fraction x of one component in the blend .These calculated parameters are compared to those of real blends. Finally, the selection of the optimal blends using the linear programming method, based on the hypothesis that the cotton blend parameters vary linearly in function of the components rations, is proved insufficient.

Texas Science Teacher Characteristics and Conceptual Understanding of Newton's Laws of Motion

Science.gov (United States)

Busby, Karin Burk

extrapolated to determine any correlations. The sample size for this study was small (n=24), requiring a second study investigate potential correlations to teacher characteristics. The second study was conducted using the 2013-2014 school year participants in the Texas Regional Collaboratives for Excellence in Science and Mathematics Teaching [TRC] (Texas Regional Collaborative for Excellence in Science and Mathematics Teaching, 2013), a statewide program led by The University of Texas at Austin Center for STEM Education (Texas Regional Collaborative for Excellence in Science and Mathematics Teaching, 2013). Participants completed a demographic survey and took the TRC Physics Assessment instrument developed for the TRC to determine current conceptual understanding of Newtonian mechanics as defined by the Texas Essential Knowledge and Skills. The TRC also collected demographic data including Texas Educational Agency region, participant's sex, years of service in teaching, current teaching position, level of highest degree earned, whether or not the participant had a STEM degree, and certification type. Correlations were determined between overall average and conceptual force questions only. The sample size was substantial (n=368) but due to time constraints in its development, the TRC Physics Assessment was unable to undergo reliability or validity testing before implementation. Test question pertaining to each of Newton's three laws of motion were extrapolated to determine any correlations. A significance value of p= 0.05 was used for all tests. Both content assessments indicated that, on average, teacher-participants had a considerable misunderstanding of Newtonian mechanics with Newton's third law questions especially difficult for the populations. Teachers' current teaching assignment was statistically significant for most tests, suggesting that high school physics teachers have more conceptual understanding of Newtonian mechanics than middle school teachers but have not

Transcriptome Profiling Using Single-Molecule Direct RNA Sequencing Approach for In-depth Understanding of Genes in Secondary Metabolism Pathways of Camellia sinensis

Directory of Open Access Journals (Sweden)

Qingshan Xu

2017-07-01

Full Text Available Characteristic secondary metabolites, including flavonoids, theanine and caffeine, are important components of Camellia sinensis, and their biosynthesis has attracted widespread interest. Previous studies on the biosynthesis of these major secondary metabolites using next-generation sequencing technologies limited the accurately prediction of full-length (FL splice isoforms. Herein, we applied single-molecule sequencing to pooled tea plant tissues, to provide a more complete transcriptome of C. sinensis. Moreover, we identified 94 FL transcripts and four alternative splicing events for enzyme-coding genes involved in the biosynthesis of flavonoids, theanine and caffeine. According to the comparison between long-read isoforms and assemble transcripts, we improved the quality and accuracy of genes sequenced by short-read next-generation sequencing technology. The resulting FL transcripts, together with the improved assembled transcripts and identified alternative splicing events, enhance our understanding of genes involved in the biosynthesis of characteristic secondary metabolites in C. sinensis.

The composition and physicochemical characteristics of MSW generated from a city of the Middle East at Ramadan Period

International Nuclear Information System (INIS)

Jeon, Yong Woo; Park, In Chul; Kim, Nam Yeol; Kim, Sung Soo; Cho, Yeun Haeng; Yoon, Kyoon Duk

2010-01-01

We investigated the worlds first composition and physicochemical characteristics of municipal solid waste (MSW) which was generated from a city of the Middle East at Ramadan period (one month in a year). 17 places in a city of the Middle East were selected for sampling MSW which were roughly classified into three categories - residential area, hotel and public facilities, and commercial area. Investigation and analysis about specific weight, physical characteristics, 3-components (moisture/ combustible/ ash), chemical characteristics, and calorific value were carried out for this research. Specific weight of waste samples depends on the physical characteristics of them, the higher moisture and non-combustible component content, the higher specific weight value. Office building, shopping mall, and school were relatively lower than other places. The average specific weight of waste in this city was equal to 0.129 ton/ m 3 which was lower than in Korea (0.2 ton/ m 3 ). Moisture and combustible component content showed a big difference between residential area and other areas. Residential area, hotel and public facilities, and commercial area showed 37.58 %, 21.80 %, and 18.81 % of moisture content, 54.79 %, 70.28 %, and 70.74 % of combustible component content, 7.63 %, 7.92 %, and 10.46 % of ash content on a wet basis, respectively. Residential area showed relatively high value of moisture content because of high content of food waste. To eat food is prohibited during the day at Ramadan period of the Middle East. But much more food than usual is made for eating after dark, and also is put into the garbage can. The results of chemical characteristics, meanwhile, are similar to Koreas. The low calorific value (LCV) of waste in residential area, hotel and public facilities, and commercial area was 2,875 kcal/ kg, 4,142 kcal/ kg, and 4,279 kcal/ kg on a wet basis, respectively. It could provide the economical and optimum design for MSW treatment system in the Middle East

Understanding the Characteristics of Dispute Settlement in Sharia Economic System

OpenAIRE

M. Arfin Hamid

2017-01-01

One of the most developed areas of Islamic law (sharia) today is “Fiqh Muamalah Iqtishadiyyah” or known as term “Sharia Economics.” The outcomes of the research indicate that the characteristics of sharia dispute are important to be understood by sharia businessmen and law enforcers. As it turns out in practice, however, it has certain weaknesses, particularly in view of the accountability and legitimacy aspects of its establishment. The sharia economic disputes, whether through litigation or...

Experimental and numerical study of waste heat recovery characteristics of direct contact thermoelectric generator

International Nuclear Information System (INIS)

Kim, Tae Young; Negash, Assmelash; Cho, Gyubaek

2017-01-01

Highlights: • Energy harvesting performance of direct contact thermoelectric generator was studied. • Power-current and voltage-current curves were given for various operating conditions. • Output power prediction using numerical results and empirical correlation was verified. • A 1.0–2.0% conversion efficiency and 5.7–11.1% heat recovery efficiency were obtained. • A 0.25% increase in efficiency was found with a 10 K decrease in coolant temperature. - Abstract: In this study, waste heat recovery performance of a direct contact thermoelectric generator (DCTEG) is experimentally investigated on a diesel engine. In order to conduct an insightful analysis of the DCTEG characteristics, three experimental parameters—engine load, rotation speed, and coolant temperature—are chosen to vary over ranges during the experiments. Experimental results show that higher temperature differences across thermoelectric modules (TEM), larger engine loads, and rotation speeds lead to an improved energy conversion efficiency of the DCTEG, which lies in the range of approximately 1.0–2.0%, while the output power ranges approximately 12–45 W. The increase in the conversion efficiency for an increased engine load becomes more noticeable with a higher engine rotation speed. A 10 K decrease in the coolant temperature yields an approximately 0.25% increase in the conversion efficiency for the engine operating conditions tested. In addition, 3D numerical simulations were conducted to investigate the heat transfer and pressure characteristics of the DCTEG. Numerically obtained exhaust gas temperatures exiting the DCTEG were in good agreement with experimental results. It is also revealed that incorporation of the temperature fields from the numerical simulation and an empirical correlation for a temperature-power relationship provides a good predictor for output power from the DCTEG, especially at low engine load conditions, which deviates from experimental results as the

Social networks as the context for understanding employment services utilization among homeless youth.

Science.gov (United States)

Barman-Adhikari, Anamika; Rice, Eric

2014-08-01

Little is known about the factors associated with use of employment services among homeless youth. Social network characteristics have been known to be influential in motivating people's decision to seek services. Traditional theoretical frameworks applied to studies of service use emphasize individual factors over social contexts and interactions. Using key social network, social capital, and social influence theories, this paper developed an integrated theoretical framework that capture the social network processes that act as barriers or facilitators of use of employment services by homeless youth, and understand empirically, the salience of each of these constructs in influencing the use of employment services among homeless youth. We used the "Event based-approach" strategy to recruit a sample of 136 homeless youth at one drop-in agency serving homeless youth in Los Angeles, California in 2008. The participants were queried regarding their individual and network characteristics. Data were entered into NetDraw 2.090 and the spring embedder routine was used to generate the network visualizations. Logistic regression was used to assess the influence of the network characteristics on use of employment services. The study findings suggest that social capital is more significant in understanding why homeless youth use employment services, relative to network structure and network influence. In particular, bonding and bridging social capital were found to have differential effects on use of employment services among this population. The results from this study provide specific directions for interventions aimed to increase use of employment services among homeless youth. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis Of Power Characteristics Of Model Thermoelectric Generator TEG Small Modular

Directory of Open Access Journals (Sweden)

Kisman H. Mahmud

2017-04-01

Full Text Available Thermoelectrically Generator TEG can generate electricity from the temperature difference between hot and cold at the junction thermoelectric module with two different semiconductor materials there will be a flow of current through the junction so as to produce a voltage. This principle uses the Seebeck effect thermoelectric generator as a base. By using these principles this research was conducted to determine the potential of the electric energy of the two peltier modules which would be an alternative source for mobile charger using heat from source of methylated. The focus in this research is the testing of the model TEG Thermoelectric Generator Small Modular to generate power with a variety of different materials of 4 namely Bi2Te3 Bismuth Telluride PbTe-Bite CMO and CMO Cascade-32-62S-32-62S Calcium Mangan oxide to use the cold side heat sink and a fan to simulate heat aluminum plate attached to the hot side of the TEG modules with heat source of methylated. Test results on the TEG Small Modular Model for mobile charger output voltage obtained from 2 pieces Bi2Te3 module Bismuth Telluride Peltier strung together a series of 3.01 Volt with amp916T of 22.7 C which produce power of 0.091 Watt.

Control of the droplet generation by an infrared laser

Directory of Open Access Journals (Sweden)

Zhibin Wang

2018-01-01

Full Text Available In this work, the control of the droplet generation by a focused infrared (IR laser with a wavelength of 1550 nm was studied, in which the liquid water and the oil with the surfactant of Span 80 were employed as the disperse and continuous phases, respectively. The characteristics of the droplet generation controlled by the laser was explored under various flow rates, laser powers and spot positions and the comparison between the cases with/without the laser was also performed. The results showed that when the laser was focused on the region away from the outlet of the liquid water inflow channel, the droplet shedding was blocked due to the IR laser heating induced thermocapillary flow, leading to the increase of the droplet volume and the cycle time of the droplet generation as compared to the case without the laser. Decreasing the continuous phase flow rate led to the increase of the droplet volume, cycle time of the droplet generation and the volume increase ratio, while increasing the disperse phase flow rate led to the increase of the droplet volume and the decrease of the cycle time and volume increase ratio. For a given flow rate ratio between the continuous and disperse phases, the increase of the flow rates decreased the volume increase ratio. In addition, it is also found that the droplet volume, the cycle time and the volume increase ratio all increased with the laser power. When the laser was focused at the inlet of the downstream channel, the droplet volume, the cycle time and the volume increase ratio were the largest. Moving the laser spot to the downstream or upstream led to the decrease of them. When the laser was focused on the outlet of the liquid water inflow channel, the generated droplet volume and cycle time of the droplet generation were even lower than the case without the laser because of the lowered viscosity. This works provides a comprehensive understanding of the characteristics of the droplet generation controlled

Emission & Generation Resource Integrated Database (eGRID)

Data.gov (United States)

U.S. Environmental Protection Agency — The Emissions & Generation Resource Integrated Database (eGRID) is an integrated source of data on environmental characteristics of electric power generation....

TFTR generator load assessment

International Nuclear Information System (INIS)

Heck, F.M.

1975-10-01

Typical experimental load demands on the TFTR generators are illustrated based on the electrical characteristics of the field coils, the coil leads, the main bus work, the various auxiliary bus work, the rectifiers, and transformers. The generator MW capacities are shown to be adequate for the proposed experimental operations with allowances made for variations in the final designs. The generator MVA capacities are shown to be adequate provided portions of the TF and EF rectifiers are freewheeled at selected times

Some new understanding on the characteristics of geological structure and uranium metallogenetic prospect on both sides of the Shandianhe down-faulted zone

International Nuclear Information System (INIS)

Zhang Xuequan

1992-01-01

On the basis of the systematic work in the field and at the laboratory, the metallogenetic prognosis map (1:100000) of geological structures and uranium metallogenetic prospect on both sides of the Shandianhe down-faulted zone is compiled. According to this, the regional setting of metallogenesis is emphatically expounded and some new understanding is presented. After the detailed study on the characteristics of geological structures on both sides of the Shangdianhe down-faulted zone, the metallogenetic prospective area are selected and the further prospecting targets in the area are suggested

Flooding characteristics of pulsed-sieve plate column. Contributed Paper ED-09

International Nuclear Information System (INIS)

Vishnu Anand, P.; Pandey, N.K.; Rajeev, R.; Joyakin, C.V.; Kamachi Mudali, U.; Natarajan, R.

2014-01-01

Successful design of a pulsed sieve plate extraction column relies on profound understanding of its hydrodynamic and mass transfer characteristics. Present work outlines a comprehensive study of flooding velocity, a hydrodynamic parameter, as a function of various operating conditions of the column. Experimental studies were carried out using water-normal paraffin hydrocarbon system, under no mass transfer condition, in a pilot plant pulsed sieve plate column equipped with standard plate cartridges. Flooding velocity is characterized here as a function of phase flow ratio and pulse velocity with the aid of characteristic velocity concept together with an exponential function. Flooding points were experimentally identified with satisfactory accuracy using a quantitative method and dispersed phase hold-up was measured by online sampling. To verify the extent of applicability of some of the reported generalized flooding correlations from a design perspective, an analysis was done using our precisely generated experimental flooding data. (author)

Lived Experiences of Low Socioeconomic Millennial Generation College Students

Science.gov (United States)

Thacker, Kelly L.

2012-01-01

The characteristics and needs of college students across the United States are ever-changing. As Millennial generation students, born between 1982 and 2003 (Howe & Strauss, 2000), attend college, unique characteristics are present. Commonalities within the Millennial generation have been identified; however, socioeconomic status can impact a…

Understanding text-based persuasion and support tactics of concerned significant others

Directory of Open Access Journals (Sweden)

Katherine van Stolk-Cooke

2015-08-01

Full Text Available The behavior of concerned significant others (CSOs can have a measurable impact on the health and wellness of individuals attempting to meet behavioral and health goals, and research is needed to better understand the attributes of text-based CSO language when encouraging target significant others (TSOs to achieve those goals. In an effort to inform the development of interventions for CSOs, this study examined the language content of brief text-based messages generated by CSOs to motivate TSOs to achieve a behavioral goal. CSOs generated brief text-based messages for TSOs for three scenarios: (1 to help TSOs achieve the goal, (2 in the event that the TSO is struggling to meet the goal, and (3 in the event that the TSO has given up on meeting the goal. Results indicate that there was a significant relationship between the tone and compassion of messages generated by CSOs, the CSOs’ perceptions of TSO motivation, and their expectation of a grateful or annoyed reaction by the TSO to their feedback or support. Results underscore the importance of attending to patterns in language when CSOs communicate with TSOs about goal achievement or failure, and how certain variables in the CSOs’ perceptions of their TSOs affect these characteristics.

Dynamic Characteristics of Positive Pulsed Dielectric Barrier Discharge for Ozone Generation in Air

International Nuclear Information System (INIS)

Wei Linsheng; Peng Bangfa; Li Ming; Zhang Yafang; Hu Zhaoji

2016-01-01

A comprehensive dynamic model consisting of 66 reactions and 24 species is developed to investigate the dynamic characteristics of ozone generation by positive pulsed dielectric barrier discharge (DBD) using parallel-plate reactor in air. The electron energy conservation equation is coupled to the electron continuity equation, the heavy species continuity equation, and Poisson's equation for a better description. The reliability of the model is experimentally confirmed. The model can be used to predict the temporal and spatial evolution of species, as well as streamer propagation. The simulation results show that electron density increases nearly exponentially in the direction to the anode at the electron avalanche. Streamer propagation velocity is about 5.26 × 10 4 m/s from anode to cathode in the simulated condition. The primary positive ion, negative ion, and excited species are O 2 + , O 3 − and O 2 ( 1 Δg) in pulsed DBD in air, respectively. N 2 O has the largest density among nitrogen oxides. e and N 2 + densities in the streamer head increase gradually to maximum values with the development of the streamer. Meanwhile, the O 2 + , O, O 3 , N 2 (A 3 Σ) and N 2 O densities reach maximum values in the vicinity of the anode. (paper)

Understanding Water Storage Practices of Urban Residents of an Endemic Dengue Area in Colombia: Perceptions, Rationale and Socio-Demographic Characteristics.

Directory of Open Access Journals (Sweden)

Tatiana García-Betancourt

Full Text Available The main preventive measure against dengue virus transmission is often based on actions to control Ae. Aegypti reproduction by targeting water containers of clean and stagnant water. Household water storage has received special attention in prevention strategies but the evidence about the rationale of this human practice is limited. The objective was to identify and describe water storage practices among residents of an urban area in Colombia (Girardot and its association with reported perceptions, rationales and socio-demographic characteristics with a mixed methods approach.Knowledge, attitudes and practices and entomological surveys from 1,721 households and 26 semi-structured interviews were conducted among residents of Girardot and technicians of the local vector borne disease program. A multivariate analysis was performed to identify associations between a water storage practice and socio-demographic characteristics, and knowledge, attitudes and practices about dengue and immature forms of the vector, which were then triangulated with qualitative information.Water storage is a cultural practice in Girardot. There are two main reasons for storage: The scarcity concern based on a long history of shortages of water in the region and the perception of high prices in water rates, contrary to what was reported by the local water company. The practice of water storage was associated with being a housewife (Inverse OR: 2.6, 95% CI 1.5 -4.3. The use of stored water depends on the type of container used, while water stored in alberca (Intra household cement basins is mainly used for domestic cleaning chores, water in plastic containers is used for cooking.It is essential to understand social practices that can increase or reduce the number of breeding sites of Ae. Aegypti. Identification of individuals who store water and the rationale of such storage allow a better understanding of the social dynamics that lead to water accumulation.

Generating Billion-Edge Scale-Free Networks in Seconds: Performance Study of a Novel GPU-based Preferential Attachment Model

Energy Technology Data Exchange (ETDEWEB)

Perumalla, Kalyan S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Alam, Maksudul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-10-01

A novel parallel algorithm is presented for generating random scale-free networks using the preferential-attachment model. The algorithm, named cuPPA, is custom-designed for single instruction multiple data (SIMD) style of parallel processing supported by modern processors such as graphical processing units (GPUs). To the best of our knowledge, our algorithm is the first to exploit GPUs, and also the fastest implementation available today, to generate scale free networks using the preferential attachment model. A detailed performance study is presented to understand the scalability and runtime characteristics of the cuPPA algorithm. In one of the best cases, when executed on an NVidia GeForce 1080 GPU, cuPPA generates a scale free network of a billion edges in less than 2 seconds.

BANKING RETAIL CONSUMER FINANCE DATA GENERATOR – CREDIT SCORING DATA REPOSITORY

Directory of Open Access Journals (Sweden)

Karol Przanowski

2013-05-01

Full Text Available This paper presents two cases of random banking data generators based on migration matrices and scoring rules. The banking data generator is a breakthrough in researches aimed at finding a method to compare various credit scoring techniques. These data are very useful for various analyses to understand the complexity of banking processes in a better way and are also of use for students and their researches. Another application can be in the case of small samples, e.g. when historical data are too fresh or are connected with the processing of a small number of exposures. In these cases a data generator can extend a sample to an adequate size for advanced analysis. The influence of one cyclic macro-economic variable on client characteristics and their stability over time is analyzed. Some stimulating conclusions for crisis behavior are presented, namely that if a crisis is impacted by both factors: application and behavioral, then it is very difficult to clearly indicate these factors in a typical scoring analysis and the crisis becomes widespread in every kind of risk report.

Quantum random number generator

Science.gov (United States)

Pooser, Raphael C.

2016-05-10

A quantum random number generator (QRNG) and a photon generator for a QRNG are provided. The photon generator may be operated in a spontaneous mode below a lasing threshold to emit photons. Photons emitted from the photon generator may have at least one random characteristic, which may be monitored by the QRNG to generate a random number. In one embodiment, the photon generator may include a photon emitter and an amplifier coupled to the photon emitter. The amplifier may enable the photon generator to be used in the QRNG without introducing significant bias in the random number and may enable multiplexing of multiple random numbers. The amplifier may also desensitize the photon generator to fluctuations in power supplied thereto while operating in the spontaneous mode. In one embodiment, the photon emitter and amplifier may be a tapered diode amplifier.

When East meets West: intensive care unit experiences among first-generation Chinese American parents.

Science.gov (United States)

Lee, Shih-Yu; Weiss, Sandra J

2009-01-01

To explore the experiences of first-generation Chinese American parents while their infants are cared for in intensive care units (ICUs). Because the study focus was on understanding the experiences of parents, a phenomenological approach was used, with open-ended questions that encouraged participants to describe events they perceived to be important. The data analysis procedure suggested by van Manen was used for the qualitative data analysis. A convenience sample of 25 first-generation Chinese American families, with infants hospitalized in the intensive care units of three teaching hospitals in the San Francisco area. Seven themes were identified: perceived incompetence, self-blame, blame from others, filial piety, lack of support in the US, communication issues, and cultural differences. Both fathers and mothers experienced stress related to all identified themes. Findings suggest the need for more resources to educate and support families as well as culturally competent care within pediatric ICUs. Further study is critical to understand how the Chinese American's personal and family characteristics may influence stress perceptions when coping with their children's hospitalization. This study can help healthcare providers to understand Chinese American parents' perceptions while their infants are hospitalized in the ICU, which can enhance cultural competence care services.

Biological characteristics of Anticarsia gemmatalis (Lepidoptera: Noctuidae) for three consecutive generations under different temperatures: understanding the possible impact of global warming on a soybean pest.

Science.gov (United States)

da Silva, D M; Hoffmann-Campo, C B; de Freitas Bueno, A; de Freitas Bueno, R C O; de Oliveira, M C N; Moscardi, F

2012-06-01

Climate changes can affect the distribution and intensity of insect infestations through direct effects on their life cycles. Experiments were carried out during three consecutive generations to evaluate the effect of different temperatures (25°C, 28°C, 31°C, 34°C and 37±1°C) on biological traits of the velvetbean caterpillar Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae). The insects were fed on artificial diet and reared in environmental chambers set at 14 h photophase. The developmental cycle slowed with the increase in the temperature, within the 25°C to 34°C range. Male and female longevities were reduced with an increase in temperature from 25°C to 28°C. Egg viability was highest at 25°C, and the sex ratio was not influenced by temperature, in the three generations. There was no interactive effect between development time and temperature on pupal weight. The results suggested that the increase in the temperature negatively impacted A. gemmatalis development inside the studied temperature range, indicating a possible future reduction of its occurrence on soybean crops, as a consequence of global warming, mainly considering its impact on tropical countries where this plant is cropped. A. gemmatalis was not able to adapt to higher temperatures in a three-generation interval for the studied temperature range. However, a gradual increase and a longer adaptation period may favor insect selection and consequently adaptation, and must be considered in future studies in this area. Moreover, it is important to consider that global warming might turn cold areas more suitable to A. gemmatalis outbreaks. Therefore, more than a future reduction of A. gemmatalis occurrence due to global warming, we might expect changes regarding its area of occurrence on a global perspective.

Heat transfer and pressure drop characteristics of the tube bank fin heat exchanger with fin punched with flow redistributors and curved triangular vortex generators

Science.gov (United States)

Liu, Song; Jin, Hua; Song, KeWei; Wang, LiangChen; Wu, Xiang; Wang, LiangBi

2017-10-01

The heat transfer performance of the tube bank fin heat exchanger is limited by the air-side thermal resistance. Thus, enhancing the air-side heat transfer is an effective method to improve the performance of the heat exchanger. A new fin pattern with flow redistributors and curved triangular vortex generators is experimentally studied in this paper. The effects of the flow redistributors located in front of the tube stagnation point and the curved vortex generators located around the tube on the characteristics of heat transfer and pressure drop are discussed in detail. A performance comparison is also carried out between the fins with and without flow redistributors. The experimental results show that the flow redistributors stamped out from the fin in front of the tube stagnation points can decrease the friction factor at the cost of decreasing the heat transfer performance. Whether the combination of the flow redistributors and the curved vortex generators will present a better heat transfer performance depends on the size of the curved vortex generators. As for the studied two sizes of vortex generators, the heat transfer performance is promoted by the flow redistributors for the fin with larger size of vortex generators and the performance is suppressed by the flow redistributors for the fin with smaller vortex generators.

An Insight towards Conceptual Understanding: Looking into the Molecular Structures of Compounds

Science.gov (United States)

Uyulgan, Melis Arzu; Akkuzu, Nalan

2016-01-01

The subject of molecular structures is one of the most important and complex subject in chemistry which a majority of the undergraduate students have difficulties to understand its concepts and characteristics correctly. To comprehend the molecular structures and their characteristics the students need to understand related subjects such as Lewis…

Simulating European wind power generation applying statistical downscaling to reanalysis data

DEFF Research Database (Denmark)

Gonzalez-Aparicio, I.; Monforti, F.; Volker, Patrick

2017-01-01

generation time series dataset for the EU-28 and neighbouring countries at hourly intervals and at different geographical aggregation levels (country, bidding zone and administrative territorial unit), for a 30 year period taking into account the wind generating fleet at the end of 2015. (C) 2017 The Authors...... and characteristics of the wind resource which is related to the accuracy of the approach in converting wind speed data into power values. One of the main factors contributing to the uncertainty in these conversion methods is the selection of the spatial resolution. Although numerical weather prediction models can...... could not be captured by the use of a reanalysis technique and could be translated into misinterpretations of the wind power peaks, ramping capacities, the behaviour of power prices, as well as bidding strategies for the electricity market. This study contributes to the understanding what is captured...

Understanding China's Transformations

DEFF Research Database (Denmark)

Li, Xing

The objective of this paper is to offer a framework of understanding the dialectical nexus between China's internal evolutions and the external influences with a focus on the century-long "challenge-response" dynamism. That is to explore how external factors helped shaping China's internal...... transformations, i.e. how generations of Chinese have been struggling in responding to the external challenges and attempting to sinicize external political ideas in order to change China from within. Likewise, it is equally important to understand how China's inner transformation contributed to reshaping...... the world. Each time, be it China's dominance or decline, the capitalist world system has to adjust and readjust itself to the opportunities and constraints brought about by the "China factors"....

Network characteristics and open innovation in SMEs

DEFF Research Database (Denmark)

Pedersen, Maja; Søndergaard, Helle Alsted; Esbjerg, Lars

The open innovation literature has primarily been concentrating on open innovation (OI) in large companies. Hence it is very unclear whether these findings can be generalized to small and medium-sized enterprises (SMEs). This paper begins filling in this knowledge gap. In doing so, we focus...... explicitly on understanding network characteristics and the unfolding of OI in SMEs. Case studies were used and empirical data was mainly generated through semi-structured interviews. Cases selected for study were companies in the Danish food industry with less than 499 employees. In this paper we report our...... findings for four cases. Our study shows that companies with a relatively open innovation process have both strong and weak ties with external partners. Companies with a relatively more closed innovation process have on the other hand only few weak ties and no strong ties with external partners....

Understanding and capturing NSSS design basis

International Nuclear Information System (INIS)

Palo, W.J.; Miller, B.

1993-01-01

Changes to, and technical evaluations of nuclear generating station designs are often warranted. Comprehensive documentation and understanding of the NSSS Design Basis are essential to support these activities. Effective configuration management tools are also needed to maintain the plant within design basis limits. Efficient design basis reconstitution can be realized via: In-depth understanding of the design process; Utilization of effective data collection methodology; State of the art data basing tools. A database can be created to generate a Design Basis Manual (DBM). This database can communicate electronically with other plant databases. A living document vice a static snapshot of the plant design is the goal. A design basis database can serve as the cornerstone for a global electronic information control system

Fourth-generation storage rings

International Nuclear Information System (INIS)

Galayda, J. N.

1999-01-01

It seems clear that a linac-driven free-electron laser is the accepted prototype of a fourth-generation facility. This raises two questions: can a storage ring-based light source join the fourth generation? Has the storage ring evolved to its highest level of performance as a synchrotrons light source? The answer to the second question is clearly no. The author thinks the answer to the first question is unimportant. While the concept of generations has been useful in motivating thought and effort towards new light source concepts, the variety of light sources and their performance characteristics can no longer be usefully summed up by assignment of a ''generation'' number

Generators of nonequilibrium low-temperature plasma

International Nuclear Information System (INIS)

Dautov, G.Yu.

1988-01-01

Results are described of a study and of the characteristics of sources of a non-equilibrium gas-discharge plasma. The plasma generators considered include glow, high frequency, and arc discharge generators. Thermodynamic, ionic, and electronic processes occurring in the plasmas are evaluated

Fragmentation characteristics of the unstable [CH3 CO][radical sign] radicals generated by neutralization of [CH3CO]+ cations

Science.gov (United States)

Hop, C. E. C. A.; Holmes, J. L.

1991-03-01

The stability and fragmentation characteristics of [CH3 CO][radical sign] radicals, generated by vertical charge exchange between acetyl cations and permanent gases or metal vapours (He, Xe, NO, Cd, Na and K), were examined mass spectrometrically. Two dissociation reactions were observed, the losses of CH[radical sign]3 and H[radical sign]. The H[radical sign] loss reaction, the higher energy dissociation, became of greater importance as the exothermicity of the charge exchange was increased. Based on the analysis of the kinetic energy releases it was concluded that these decompositions arose from the population of two excited states of the [CH3 CO][radical sign] radical.

Millennials at Work: Investigating the Specificity of Generation Y versus Other Generations

Directory of Open Access Journals (Sweden)

Florina PÎNZARU

2016-06-01

Full Text Available The present study intends to discuss the psychological profile of Generation Y versus other generations.The differences between Millennials and other generations are addressed in terms of values, personality characteristics, and reactions under stress. The topicality and relevance of the research theme are supported by the fact that most of the people who are currently employed in companies all over the world are members of the Generation Y. This situation requires a proper investigation of the characteristics and specificity of the so-called Millennials with a view to provide organizations with pertinent inputs for designing well-informed policies and for smoothly integrating Millennials in the workplace. To this end, Hogan Assessments personality inventories were applied online to more than 1000 persons from Generation Y (up to 29 years old and more than 3000 persons from other generations (above 29 years old. Among others, the findings show that Millennials are motivated by recognition, public acknowledgment, instant and frequent positive feedback and gratification. As they need balance between personal and professional life, as well as a comfortable environment, they require a flexible work schedule, resent staying after hours. Being motivated to become part of various social networks, work in various teams, Millennials are able to easily find satisfaction in missions that involve interactions with new persons coming from different cultures and geographical areas. They are motivated by work in a nonconformist environment without strict rules and traditional work approaches, they tend to challenge the status quo and they will not be patient to keep the same job many years.

Characterization of the Advanced Stirling Radioisotope Generator EU2

Science.gov (United States)

Lewandowski, Edward J.; Oriti, Salvatore M.; Schifer, Nicholas A.

2015-01-01

Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG), a 140-watt radioisotope power system. While the ASRG flight development project has ended, the hardware that was designed and built under the project is continuing to be tested to support future Stirling-based power system development. NASA GRC recently completed the assembly of the ASRG Engineering Unit 2 (EU2). The ASRG EU2 consists of the first pair of Sunpower's ASC-E3 Stirling convertors mounted in an aluminum housing, and Lockheed Martin's Engineering Development Unit (EDU) 4 controller (a fourth generation controller). The ASC-E3 convertors and Generator Housing Assembly (GHA) closely match the intended ASRG Qualification Unit flight design. A series of tests were conducted to characterize the EU2, its controller, and the convertors in the flight-like GHA. The GHA contained an argon cover gas for these tests. The tests included: measurement of convertor, controller, and generator performance and efficiency, quantification of control authority of the controller, disturbance force measurement with varying piston phase and piston amplitude, and measurement of the effect of spacecraft DC bus voltage on EU2 performance. The results of these tests are discussed and summarized, providing a basic understanding of EU2 characteristics and the performance and capability of the EDU 4 controller.

Heat transfer characteristics and entropy generation for wing-shaped-tubes with longitudinal external fins in cross-flow

International Nuclear Information System (INIS)

Ahmed, Sayed Ahmed E. Sayed; Mesalhy, Osama M.; Abdelatief, Mohamed A.

2016-01-01

A numerical study is conducted to clarify heat transfer characteristics, effectiveness and entropy generation for a bundle of wingshaped-tubes attached to Longitudinal fins (LF) at downstream side. The air-side Re a ranged from 1.8 x 10 3 to 9.7 x 10 3 . The fin height (h f ) and fin thickness (δ) have been changed as: (2 mm <= hf <= 12 mm) and (1.5 mm <= δ <= 3.5 mm). The analysis of entropy generation is based on the principle of minimizing the rate of total entropy generation that includes the generation of entropy due to heat transfer and friction losses. The temperature field around the wing-shaped-tubes with (LF) is predicted using commercial CFD FLUENT 6.3.26 software package. Correlations of Nu a , St a , and Bejan number (Be), as well as the irreversibility distribution ratio (Φ) in terms of Re a and design parameters for the studied bundle are presented. Results indicated that, installing fins with heights from 2 to 12 mm results in an increase in Nu a from 11 to 36% comparing with that of wing-shaped tubes without fins (NOF). The highest and lowest values of effectiveness(ε) at every value of the considered Re a range are occurred at hf = 6 mm and (NOF), espectively. The wing-shaped-tubes heat exchanger with hf = 6 mm has the highest values of (ε), efficiency index (η) and area goodness factor (G a ) and also the lowest values of Φ and hence the best performance comparing with other arrangements. The minimum values of Φ are occurred at hf = 6 mm. (Be) decreases with increasing Re a for all studied hf. The heat transfer irreversibility predominates for (1800 <= Re a <= 4200) while the opposite is true for (6950 < Re a <= 9700). δ has negligible effect on Nu a and heat transfer irreversibility. Comparisons between the experimental and numerical results of the present study and those, previously, obtained for similar available studies showed good agreements.

Understanding processes that generate flash floods in the arid Judean Desert to the Dead Sea - a measurement network

Science.gov (United States)

Hennig, Hanna; Rödiger, Tino; Laronne, Jonathan B.; Geyer, Stefan; Merz, Ralf

2016-04-01

Flash floods in (semi-) arid regions are fascinating in their suddenness and can be harmful for humans, infrastructure, industry and tourism. Generated within minutes, an early warning system is essential. A hydrological model is required to quantify flash floods. Current models to predict flash floods are often based on simplified concepts and/or on concepts which were developed for humid regions. To more closely relate such models to local conditions, processes within catchments where flash floods occur require consideration. In this study we present a monitoring approach to decipher different flash flood generating processes in the ephemeral Wadi Arugot on the western side of the Dead Sea. To understand rainfall input a dense rain gauge network was installed. Locations of rain gauges were chosen based on land use, slope and soil cover. The spatiotemporal variation of rain intensity will also be available from radar backscatter. Level pressure sensors located at the outlet of major tributaries have been deployed to analyze in which part of the catchment water is generated. To identify the importance of soil moisture preconditions, two cosmic ray sensors have been deployed. At the outlet of the Arugot water is sampled and level is monitored. To more accurately determine water discharge, water velocity is measured using portable radar velocimetry. A first analysis of flash flood processes will be presented following the FLEX-Topo concept .(Savenije, 2010), where each landscape type is represented using an individual hydrological model according to the processes within the three hydrological response units: plateau, desert and outlet. References: Savenije, H. H. G.: HESS Opinions "Topography driven conceptual modelling (FLEX-Topo)", Hydrol. Earth Syst. Sci., 14, 2681-2692, doi:10.5194/hess-14-2681-2010, 2010.

Characteristics of transitional and turbulent jet diffusion flames in microgravity

Science.gov (United States)

Bahadori, Yousef M.; Small, James F., Jr.; Hegde, Uday G.; Zhou, Liming; Stocker, Dennis P.

1995-01-01

This paper presents the ground-based results obtained to date in preparation of a proposed space experiment to study the role of large-scale structures in microgravity transitional and turbulent gas-jet diffusion flames by investigating the dynamics of vortex/flame interactions and their influence on flame characteristics. The overall objective is to gain an understanding of the fundamental characteristics of transitional and turbulent gas-jet diffusion flames. Understanding of the role of large-scale structures on the characteristics of microgravity transitional and turbulent flames will ultimately lead to improved understanding of normal-gravity turbulent combustion.

Socialization and Information Horizons: Source Use Behavior of First-Generation and Continuing-Generation College Students

Science.gov (United States)

Tsai, Tien-I

2013-01-01

First-generation college (FGC) students have been described as an underrepresented group in comparison to their continuing-generation counterparts (non-FGC students). Studying college students' socialization experiences and their use of academic resources can help us understand how to facilitate their academic success. Incorporating…

TFTR Motor Generator

International Nuclear Information System (INIS)

Murray, J.G.; Bronner, G.; Horton, M.

1977-01-01

A general description is given of 475 MVA pulsed motor generators for TFTR at Princeton Plasma Physics Laboratory. Two identical generators operating in parallel are capable of supplying 950 MVA for an equivalent square pulse of 6.77 seconds and 4,500 MJ at 0.7 power factor to provide the energy for the pulsed electrical coils and heating system for TFTR. The description includes the operational features of the 15,000 HP wound rotor motors driving each generator with its starting equipment and cycloconverter for controlling speed, power factor, and regulating line voltage during load pulsing where the generator speed changes from 87.5 to 60 Hz frequency variation to provide the 4,500 MJ or energy. The special design characteristics such as fatigue stress calculations for 10 6 cycles of operation, forcing factor on exciter to provide regulation, and low generator impedance are reviewed

Employers and the New Generation of Employees

Science.gov (United States)

Smith, W. Stanton

2006-01-01

There are three generations that exist in the workplace today: baby boomers, Gen X, and Gen Y. Each generation shows an entire spectrum of human values, attitudes and beliefs. This article describes the characteristic attitudes and expectations of each generation. The author examines the differences that cause conflict and describes coping…

Spectroscopy, Understanding the Atom Series.

Science.gov (United States)

Hellman, Hal

This booklet is one of the "Understanding the Atom" Series. The science of spectroscopy is presented by a number of topics dealing with (1) the uses of spectroscopy, (2) its origin and background, (3) the basic optical systems of spectroscopes, spectrometers, and spectrophotometers, (4) the characteristics of wave motion, (5) the…

Understanding Motivational Factors in Business Environment: Difference Between Baby Boomers, Generation X, and Y

OpenAIRE

Vuokko, Essi

2016-01-01

The purpose of the thesis is to research and evaluate the motivational differences between three different generations, Baby Boomers (born between 1946 and 1964), generation X (born between 1965 and 1980) and generation Y (born between 1981 and 200), in business environment. As the earlier studies regarding the topic suggest, there are notable differences between the generations’ preferred rewarding systems and working environments, for example. Due to these expected differences in the ch...

Output characteristics of floating type wave power generator system using a ball screw; Fuyugata nejishiki haryoku hatsuden sochi no shutsuryoku tokusei

Energy Technology Data Exchange (ETDEWEB)

Abe, T; Omata, K [Meiji University, Tokyo (Japan)

1996-10-27

A floating type wave power generator system using a ball screw is proposed. Output characteristics are simulated on the supposition of its employment aboard a navigational aid buoy. The relative linear movement produced by waves between the main body and float is transmitted via a load column to a ball nut and is converted into a rotary movement of a threaded shaft engaging the ball nut. Attached to the bottom end of the threaded shaft is a one-way clutch which connects to the generator axle when the relative velocity between the float and main body is positive. The simulation was conducted for a wave activated power generation buoy, 2.6m in outer diameter, 4.5m in length, and 6000kg in total mass. The buoy generated a mechanical output of 340kW when exposed to a sinusoidal wave 2.5 seconds in period and 40cm in wave height. A tank test was performed using a reduced scale model consisting of a ball screw, bicycle dynamo, and float, with the main body being 318mm in diameter and 833mm in length, when an average output of 4.51W was obtained at 60% efficiency. The results of the experiment agreed in some degree with the results of calculation, verifying the righteousness of the theoretical formula. 3 refs., 7 figs., 4 tabs.

Managing Multiple Generations in the Workplace.

Science.gov (United States)

Clark, Kevin R

2017-03-01

Today's workplace often includes workers from 4 distinct generations, and each generation brings a unique set of core values and characteristics to an organization. These generational differences can produce benefits, such as improved patient care, as well as challenges, such as conflict among employees. This article reviews current research on generational differences in educational settings and the workplace and discusses the implications of these findings for medical imaging and radiation therapy departments. ©2017 American Society of Radiologic Technologists.

Knowing Generation Y: a new generation of nurses in practice.

Science.gov (United States)

Chung, Stephanie M

Generation Y is commonly defined as those people born between 1980 and 2000, now aged in their 20s and 30s. Their grandparents experienced post-World War II reconstruction, their parents the economic boom of the 1980s. There are currently 81 million individuals in the Generation Y cohort in the USA, making it the second-largest, and possibly most influential, cohort since World War II (Manion, 2009). Members of Generation Y are diverse, technologically advanced and vocal about their opinions. They tend to resist traditional hierarchy, want recognition/reward for achievements and distrust institutions. Knowing these characteristics is useful for nurse managers, preceptors and team members working with members of Generation Y. Studies have proven that Generation Y is challenging the nursing workforce through rapid turnover (Cogin, 2012). This article explores a theoretical model that predicts retention and/or turnover of nurses in light of Generation Y behaviours and motivators-for example, moving from agency to agency rather than devoting many years to a single practice. Further research is needed to find out whether these behaviours and motivators are unique to Generation Y alone.

Trip generation and data analysis study.

Science.gov (United States)

2015-09-01

Through the Trip Generation and Data Analysis Study, the District of Columbia Department of : Transportation (DDOT) is undertaking research to better understand multimodal urban trip generation : at mixed-use sites in the District. The study is helpi...

Influence of the RF electrode cleanliness on plasma characteristics and dust-particle generation in methane dusty plasmas

Science.gov (United States)

Géraud-Grenier, I.; Desdions, W.; Faubert, F.; Mikikian, M.; Massereau-Guilbaud, V.

2018-01-01

The methane decomposition in a planar RF discharge (13.56 MHz) leads both to a dust-particle generation in the plasma bulk and to a coating growth on the electrodes. Growing dust-particles fall onto the grounded electrode when they are too heavy. Thus, at the end of the experiment, the grounded electrode is covered by a coating and by fallen dust-particles. During the dust-particle growth, the negative DC self-bias voltage (VDC) increases because fewer electrons reach the RF electrode, leading to a more resistive plasma and to changes in the plasma chemical composition. In this paper, the cleanliness influence of the RF electrode on the dust-particle growth, on the plasma characteristics and composition is investigated. A cleanliness electrode is an electrode without coating and dust-particles on its surface at the beginning of the experiment.

THE CHOICE OF THE GENERATOR AND ELECTRICITY STABILIZATION FOR SMALL HYDROPOWER PLANTS

OpenAIRE

Kvitko A. V.; Daybova L. A.; Kondratenko Y. E.

2015-01-01

The article analyzes the main characteristics of the electricity generators to use them as a part of small hydroelectric power plants. It is shown, that contactless asynchronous generators in comparison with synchronous generators and DC generators have improved their operational and technical characteristics, and above all, their reliability and performance efficiency. We have shown graphic dependences of the cost and the weight of power generators. It is proposed using direct frequency conv...

Effects of sporadic E-layer characteristics on spread-F generation in the nighttime midlatitude ionosphere: A climatological study

Science.gov (United States)

Lee, C. C.; Chen, W. S.

2018-04-01

The aim of this study is to examine the effects of Es-layer characteristics on spread-F generation in the nighttime midlatitude ionosphere. The Es-layer parameters and spread-F appearance of the 23rd solar cycle (1996-2008) are recorded by the Kokubunji ionosonde. The Es-layer parameters are foEs (critical frequency of Es-layer), fbEs (blanketing frequency of Es-layer), and Δf (≡foEs-fbEs). In order to completely explore the effects, the pre-midnight and post-midnight data are classified by seasons, solar activities, and geomagnetic conditions. Results show that the spread-F occurs more frequently in post-midnight and in summer. And, the occurrence probabilities of spread-F are greater, when the solar activity is lower. For the occurrence probabilities of spread-F versus foEs and Δf under geomagnetic quiet-conditions, the trend is increasing, when the associated probabilities are significant. These indicate that the spread-F occurrence increases with increasing foEs and/or Δf. Further, the increasing trends demonstrate that polarization electric fields generated in Es-layer would be helpful to generate spread-F, through the electrodynamical coupling of Es-layer and F-region. Moreover, this electrodynamical coupling is efficient not only under quiet-conditions but under disturbed-conditions, since the significant increasing trend can also be found under disturbed-conditions. Regarding the occurrence probabilities of spread-F versus fbEs, the evident trends are not in the majority. This implies that fbEs might not be a major factor for the spread-F formation.

Understanding the ‘Intensive’ in ‘Data Intensive Research’: Data Flows in Next Generation Sequencing and Environmental Networked Sensors

Directory of Open Access Journals (Sweden)

Ruth McNally

2012-03-01

Full Text Available Genomic and environmental sciences represent two poles of scientific data. In the first, highly parallel sequencing facilities generate large quantities of sequence data. In the latter, loosely networked remote and field sensors produce intermittent streams of different data types. Yet both genomic and environmental sciences are said to be moving to data intensive research. This paper explores and contrasts data flow in these two domains in order to better understand how data intensive research is being done. Our case studies are next generation sequencing for genomics and environmental networked sensors.Our objective was to enrich understanding of the ‘intensive’ processes and properties of data intensive research through a ‘sociology’ of data using methods that capture the relational properties of data flows. Our key methodological innovation was the staging of events for practitioners with different kinds of expertise in data intensive research to participate in the collective annotation of visual forms. Through such events we built a substantial digital data archive of our own that we then analysed in terms of three traits of data flow: durability, replicability and metrology.Our findings are that analysing data flow with respect to these three traits provides better insight into how doing data intensive research involves people, infrastructures, practices, things, knowledge and institutions. Collectively, these elements shape the topography of data and condition how it flows. We argue that although much attention is given to phenomena such as the scale, volume and speed of data in data intensive research, these are measures of what we call ‘extensive’ properties rather than intensive ones. Our thesis is that extensive changes, that is to say those that result in non-linear changes in metrics, can be seen to result from intensive changes that bring multiple, disparate flows into confluence.If extensive shifts in the modalities of

Electrostatic Swelling and Conformational Variation Observed in High-Generation Polyelectrolyte Dendrimers

International Nuclear Information System (INIS)

Butler, Paul D.; Chen, Wei-Ren; Herwig, Kenneth W.; Hong, Kunlun; Liu, Yun; Porcar, L.; Shew, Chwen-Yang; Smith, Gregory Scott; Chen, Hsin-Lung; Chen, Chun-Yu; Li, Xin; Liu, Emily

2010-01-01

A coordinated study combining small angle neutron scattering (SANS) and small angle x-ray scattering (SAXS) measurements was conducted to investigate the structural characteristics of aqueous (D2O) generation 7 and 8 (G7 and G8) PAMAM dendrimer solutions as a function of molecular protonation at room temperature. The change in intra-molecular conformation was clearly exhibited in the data analysis by separating the variation in the inter-molecular correlation. Our results unambiguously demonstrate an increased molecular size and evolved intra-molecular density profile upon increasing the molecular protonation. This is contrary to the existing understanding that in higher generation polyelectrolyte dendrimers, steric crowding stiffens the local motion of dendrimer segments exploring additional available intra-dendrimer volume and therefore inhibits the electrostatic swelling. Our observation is relevant to elucidation of the general microscopic picture of polyelectrolyte dendrimer structure, as well as the development of dendrimer-based packages with based on the stimuli-responsive principle.

Pulse power applications of flux compression generators

International Nuclear Information System (INIS)

Fowler, C.M.; Caird, R.S.; Erickson, D.J.; Freeman, B.L.

1981-01-01

Characteristics are presented for two different types of explosive driven flux compression generators and a megavolt pulse transformer. Status reports are given for rail gun and plasma focus programs for which the generators serve as power sources

Characteristics of the Understanding and Expression of Emotional Prosody among Children with Autism Spectrum Disorder

DEFF Research Database (Denmark)

Yoshimatsu, Yasufumi; Umino, Ayumi; Dammeyer, Jesper

2016-01-01

In verbal communication with others, children with Autism Spectrum Disorders (ASD) experience difficulties with understanding jokes, irony, and other pragmatic aspects of communication. Difficulties with the understanding and expression of prosody may be one reason. In this study an understanding...

Generation-specific incentives and disincentives for nurse faculty to remain employed.

Science.gov (United States)

Tourangeau, Ann E; Wong, Matthew; Saari, Margaret; Patterson, Erin

2015-05-01

The aims of this paper are to: (1) describe work characteristics that nurse faculty report encourage them to remain in or leave their academic positions; and (2) determine if there are generational differences in work characteristics selected. Nurse faculty play key roles in preparing new nurses and graduate nurses. However, educational institutions are challenged to maintain full employment in faculty positions. A cross-sectional, descriptive survey design was employed. Ontario nurse faculty were asked to select, from a list, work characteristics that entice them to remain in or leave their faculty positions. Respondent data (n = 650) were collected using mailed surveys over four months in 2011. While preferred work characteristics differed across generations, the most frequently selected incentives enticing nurse faculty to stay were having: a supportive director/dean, reasonable workloads, supportive colleagues, adequate resources, manageable class sizes and work/life balance. The most frequently selected disincentives included: unmanageable workloads, unsupportive organizations, poor work environments, exposure to bullying, belittling and other types of incivility in the workplace and having an unsupportive director/dean. This research yields new and important knowledge about work characteristics that nurse faculty report shape their decisions to remain in or leave their current employment. Certain work characteristics were rated as important among all generations. Where similarities exist, broad strategies addressing work characteristics may effectively promote nurse faculty retention. However, where generational differences exist, retention-promoting strategies should target generation-specific preferences. © 2014 John Wiley & Sons Ltd.

Wind Turbine Generator Efficiency Based on Powertrain Combination and Annual Power Generation Prediction

Directory of Open Access Journals (Sweden)

Dongmyung Kim

2018-05-01

Full Text Available Wind turbine generators are eco-friendly generators that produce electric energy using wind energy. In this study, wind turbine generator efficiency is examined using a powertrain combination and annual power generation prediction, by employing an analysis model. Performance testing was conducted in order to analyze the efficiency of a hydraulic pump and a motor, which are key components, and so as to verify the analysis model. The annual wind speed occurrence frequency for the expected installation areas was used to predict the annual power generation of the wind turbine generators. It was found that the parallel combination of the induction motors exhibited a higher efficiency when the wind speed was low and the serial combination showed higher efficiency when wind speed was high. The results of predicting the annual power generation considering the regional characteristics showed that the power generation was the highest when the hydraulic motors were designed in parallel and the induction motors were designed in series.

Aerosol generation and delivery in medical applications

International Nuclear Information System (INIS)

Soni, P.S.; Raghunath, B.

1998-01-01

It is well established that radioaerosol lung technique by inhalation is a very versatile technique in the evaluation of health effects and medical diagnostic applications, especially to detect chronic obstructive pulmonary diseases, their defence mechanism permeability and many others. Most important part of aerosol technology is to generate reproducibly stable diagnostic radioaerosols of known characteristics. Many compressed air atomisers are commercially available for generating aerosols but they have limited utility in aerosol inhalation, either because of large droplet size, low aerosol output or high airflow rates. There is clearly a need for a versatile and economical aerosol generation/inhalation system that can produce dry labelled aerosol particles with high deep lung delivery efficiency suitable for clinical studies. BARC (Bhabha Atomic Research Centre) has developed a dry aerosol generation/delivery system which operates on compressed air and generates dry polydisperse aerosols. This system is described along with an assessment of the aerosol characteristics and efficiency for diagnosis of various respiratory disorders

An experimental study of water absorption characteristics for generator stator winding insulation

International Nuclear Information System (INIS)

Lee, D. S.; Bae, Y. C.; Kim, H. S.; Kim, Y. H.; Lee, H.

2004-01-01

Leaking water coolant into stator electrical insulation is a growing concern for the aging water-cooled generator since leaks in the generator water-cooled stator winding can affect machine availability and insulation life. But a domestic techniques of such field are insufficient and depend wholly on GE or TOSHIBA technique. Therefore this paper introduces measuring principle and developed measuring system, which has been used to detecting wet absorption. We accomplished the experiment with a stator promotion of virtue which is used in actual power plant. Also, experimental method of generator stator winding, which is investigated into wet absorption test

Arc discharge characteristics of molten salts used in an MHD generator

International Nuclear Information System (INIS)

Korenaga, Sadayoshi; Mohri, Motoichi.

1981-01-01

The seed arc discharge phenomena in an MHD generator were studied. The behavior of arc was observed, which was generated by using K 2 CO 3 and K 2 SO 4 heated up to 1150 degree C as cathodes and a water-cooled copper as an anode. The generated arcs were classified into 3 types, such as free spot arc (point arc), line emission arc (line arc) and plane arc. The estimated temperature of arc foot was lower than the boiling point of seed material. The relation between arc voltage and arc length and that between arc voltage and arc current were measured. From these data, the potential gradient of arc was obtained. The gradients were same for almost all materials of cathode. The potential drop at cathodes depended remarkably on the kinds of molten salt, and also depended on the shapes of cathodes. The evaporation rate of cathode materials was larger when the cathode potential drop was larger and the arc current was larger. (Kato, T.)

Building the Capacity for Climate Services: Thoughts on Training Next Generation Climate Science Integrators

Science.gov (United States)

Garfin, G. M.; Brugger, J.; Gordon, E. S.; Barsugli, J. J.; Rangwala, I.; Travis, W.

2015-12-01

For more than a decade, stakeholder needs assessments and reports, including the recent National Climate Assessment, have pointed out the need for climate "science translators" or "science integrators" who can help bridge the gap between the cultures and contexts of researchers and decision-makers. Integration is important for exchanging and enhancing knowledge, building capacity to use climate information in decision making, and fostering more robust planning for decision-making in the context of climate change. This talk will report on the characteristics of successful climate science integrators, and a variety of models for training the upcoming generation of climate science integrators. Science integration characteristics identified by an experienced vanguard in the U.S. include maintaining credibility in both the scientific and stakeholder communities, a basic respect for stakeholders demonstrated through active listening, and a deep understanding of the decision-making context. Drawing upon the lessons of training programs for Cooperative Extension, public health professionals, and natural resource managers, we offer ideas about training next generation climate science integrators. Our model combines training and development of skills in interpersonal relations, communication of science, project implementation, education techniques and practices - integrated with a strong foundation in disciplinary knowledge.

Seasonal features of atmospheric surface-layer characteristics over a tropical coastal station in Southern India

International Nuclear Information System (INIS)

Hari Prasad, K.B.R.R.; Srinivas, C.V.; Baskaran, R.; Venkatraman, B.

2016-01-01

Dispersion of air-borne effluents occurs in the atmospheric boundary layer (ABL) where turbulence is the main physical processes. In the surface layer of ABL, the mechanical (shear) generation of turbulence exceeds the buoyant generation or consumption of turbulence. In this layer, under steady state and horizontally homogeneous conditions various forces in the governing equation can be neglected and one can apply Monin-Obukhov Similarity Theory (MOST) to estimate the turbulent fluxes and other surface layer variables. Understanding the turbulent characteristics of the surface layer is vital for modeling of turbulent diffusion in regional numerical weather and pollution dispersion models. The objective of this study is to verify the validity of the MOST at the coastal site Kalpakkam under various atmospheric stability conditions with respect to different seasons for modeling atmospheric dispersion of radioactive effluents

Generator technology for HTGR power plants

International Nuclear Information System (INIS)

Lomba, D.; Thiot, D.

1997-01-01

Approximately 15% of the worlds installed capacity in electric energy production is from generators developed and manufactured by GEC Alsthom. GEC Alsthom is now working on the application of generators for HTGR power conversion systems. The main generator characteristics induced by the different HTGR power conversion technology include helium immersion, high helium pressure, brushless excitation system, magnetic bearings, vertical lineshaft, high reliability and long periods between maintenance. (author)

Revolutionizing Our Understanding of AGN Feedback and its Importance to Galaxy Evolution in the Era of the Next Generation Very Large Array

Science.gov (United States)

Nyland, K.; Harwood, J. J.; Mukherjee, D.; Jagannathan, P.; Rujopakarn, W.; Emonts, B.; Alatalo, K.; Bicknell, G. V.; Davis, T. A.; Greene, J. E.; Kimball, A.; Lacy, M.; Lonsdale, Carol; Lonsdale, Colin; Maksym, W. P.; Molnár, D. C.; Morabito, L.; Murphy, E. J.; Patil, P.; Prandoni, I.; Sargent, M.; Vlahakis, C.

2018-05-01

Energetic feedback by active galactic nuclei (AGNs) plays an important evolutionary role in the regulation of star formation on galactic scales. However, the effects of this feedback as a function of redshift and galaxy properties such as mass, environment, and cold gas content remain poorly understood. The broad frequency coverage (1 to 116 GHz), high sensitivity (up to ten times higher than the Karl G. Jansky Very Large Array), and superb angular resolution (maximum baselines of at least a few hundred kilometers) of the proposed next-generation Very Large Array (ngVLA) are uniquely poised to revolutionize our understanding of AGNs and their role in galaxy evolution. Here, we provide an overview of the science related to AGN feedback that will be possible in the ngVLA era and present new continuum ngVLA imaging simulations of resolved radio jets spanning a wide range of intrinsic extents. We also consider key computational challenges and discuss exciting opportunities for multiwavelength synergy with other next-generation instruments, such as the Square Kilometer Array and the James Webb Space Telescope. The unique combination of high-resolution, large collecting area, and wide frequency range will enable significant advancements in our understanding of the effects of jet-driven feedback on sub-galactic scales, particularly for sources with extents of a few parsec to a few kiloparsec, such as young and/or lower-power radio AGNs, AGNs hosted by low-mass galaxies, radio jets that are interacting strongly with the interstellar medium of the host galaxy, and AGNs at high redshift.

Leg mass characteristics of accurate and inaccurate kickers--an Australian football perspective.

Science.gov (United States)

Hart, Nicolas H; Nimphius, Sophia; Cochrane, Jodie L; Newton, Robert U

2013-01-01

Athletic profiling provides valuable information to sport scientists, assisting in the optimal design of strength and conditioning programmes. Understanding the influence these physical characteristics may have on the generation of kicking accuracy is advantageous. The aim of this study was to profile and compare the lower limb mass characteristics of accurate and inaccurate Australian footballers. Thirty-one players were recruited from the Western Australian Football League to perform ten drop punt kicks over 20 metres to a player target. Players were separated into accurate (n = 15) and inaccurate (n = 16) groups, with leg mass characteristics assessed using whole body dual energy x-ray absorptiometry (DXA) scans. Accurate kickers demonstrated significantly greater relative lean mass (P ≤ 0.004) and significantly lower relative fat mass (P ≤ 0.024) across all segments of the kicking and support limbs, while also exhibiting significantly higher intra-limb lean-to-fat mass ratios for all segments across both limbs (P ≤ 0.009). Inaccurate kickers also produced significantly larger asymmetries between limbs than accurate kickers (P ≤ 0.028), showing considerably lower lean mass in their support leg. These results illustrate a difference in leg mass characteristics between accurate and inaccurate kickers, highlighting the potential influence these may have on technical proficiency of the drop punt.

Understanding China’s Economic Success

DEFF Research Database (Denmark)

Li, Xing

2016-01-01

This study attempts to provide a framework for understanding the role of the “embeddedness” in China’s economic success reflected by a unique embedded integration of state-market-society relations. “Embeddedness with Chinese characteristics” is the central concept of this study for analyzing how...... cultural and political uniqueness influences economic activities and shapes distinctive institutional forms. In order to grasp the factors behind the Chinese economic success, it is important to understand how the disembedded forces of marketization and commodification were balanced by the embedded forces...... context to explain and analyze the “embedded” hegemony in transitional China. The first part of the this paper provides a conceptual framework for understanding socio-cultural and political embeddedness in China and the second part analyzes some characteristics of the state-market-society embedded process...

Reliability Evaluation of Distribution System Considering Sequential Characteristics of Distributed Generation

Directory of Open Access Journals (Sweden)

Sheng Wanxing

2016-01-01

Full Text Available In allusion to the randomness of output power of distributed generation (DG, a reliability evaluation model based on sequential Monte Carlo simulation (SMCS for distribution system with DG is proposed. Operating states of the distribution system can be sampled by SMCS in chronological order thus the corresponding output power of DG can be generated. The proposed method has been tested on feeder F4 of IEEE-RBTS Bus 6. The results show that reliability evaluation of distribution system considering the uncertainty of output power of DG can be effectively implemented by SMCS.

Engaging a New Generation of Graduates

Science.gov (United States)

Shaw, Sue; Fairhurst, David

2008-01-01

Purpose: The purpose of this paper is to explore the concept of generational difference and reflect on how this might impact on organisational approaches to graduate development. Design/methodology/approach: The paper explores the characteristics of Generation Y graduates and the implications of their entry into the workplace for organisations'…

Hipse: an event generator for nuclear collisions at intermediate energies

International Nuclear Information System (INIS)

Lacroix, D.; Van Lauwe, A.; Durand, D.

2003-11-01

An event generator, HIPSE (Heavy-Ion Phase-Space Exploration), dedicated to the description of nuclear collisions in the intermediate energy range is presented. Based on the sudden approximation and on geometrical hypothesis, it can conveniently simulate heavy-ion interactions at all impact parameters and thus can constitute a valuable tool for the understanding of processes such as neck emission or multifragmentation in peripheral or/and central collisions. After a detailed description of the ingredients of the model, first comparisons with experimental data collected by the INDRA collaboration are shown. Special emphasis is put on the kinematical characteristics of fragments and light particles observed at all impact parameters for Xe+Sn reactions at 25 and 50 MeV/u and Ni + Ni at 82 MeV/u. (authors)

Characterization of the Advanced Stirling Radioisotope Generator Engineering Unit 2

Science.gov (United States)

Lewandowski, Edward J.; Oriti, Salvatore M.; Schifer, Niholas A.

2016-01-01

Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG) 140-W radioisotope power system. While the ASRG flight development project has ended, the hardware that was designed and built under the project is continuing to be tested to support future Stirling-based power system development. NASA Glenn Research Center recently completed the assembly of the ASRG Engineering Unit 2 (EU2). The ASRG EU2 consists of the first pair of Sunpower's Advanced Stirling Convertor E3 (ASC-E3) Stirling convertors mounted in an aluminum housing, and Lockheed Martin's Engineering Development Unit (EDU) 4 controller (a fourth-generation controller). The ASC-E3 convertors and Generator Housing Assembly (GHA) closely match the intended ASRG Qualification Unit flight design. A series of tests were conducted to characterize the EU2, its controller, and the convertors in the flight-like GHA. The GHA contained an argon cover gas for these tests. The tests included measurement of convertor, controller, and generator performance and efficiency; quantification of control authority of the controller; disturbance force measurement with varying piston phase and piston amplitude; and measurement of the effect of spacecraft direct current (DC) bus voltage on EU2 performance. The results of these tests are discussed and summarized, providing a basic understanding of EU2 characteristics and the performance and capability of the EDU 4 controller.

Study of damping characteristics of fibre reinforced composite aerospace structure

International Nuclear Information System (INIS)

Khan, M.Z.; Saleh, S.; Munir, A.

2006-01-01

Composite materials are used in a variety of high demanding structural applications. Apart from their other preferable properties, they have high-energy dissipation characteristics, which is important aspect when we repeatedly wiggle the system back and forth. It is important to have thorough understanding of material damping behavior; in general materials damping tends to be complex nonlinear function of vibration amplitude, frequency of loading and material formulation. There are number of mathematical models available in literature to obtain hysteresis curves. One approach for identifying damping characteristics used mechanical hysteresis curves. In present work, a phenomenon was observed during testing of fibre reinforced composite beam of an aerospace structure, that for increase load in structure, the path of Force vs. Displacement curve is different than the path of unloading. A plot is generated which indicate the hysteresis loop representing the steady state dynamic behavior of material. The area enclosed by such curves is proportional to energy dissipation per cycle. However, the specific shape of the curve also has important implications for characterizing the specific functional form of the damping. Therefore, it is important to develop methods for accurately accounting for such effects. The current work explores the damping characteristics both theoretically and experimentally. (author)

User-Generated Video and Intertextuality

DEFF Research Database (Denmark)

Christensen, Lars Holmgaard; Rasmussen, Tove Arendt; Kofoed, Peter

This paper discusses the changing relationship between texts, producers and audiences and tries to understand user-generated audio-visual content or to be more precise, intertextuality in user-generated videos in relation to distribution formats, cultural form and genres. Continuing on from...... the work of John Fiske and the notion of vertical and horizontal intertextuality this paper tries to develop Fiske's original ideas so that his model incorporates the changing relationship between producers and their audiences, the text generated by mainstream media and the text generated by ordinary...

How to generate and interpret fire characteristics charts for surface and crown fire behavior

Science.gov (United States)

Patricia L. Andrews; Faith Ann Heinsch; Luke Schelvan

2011-01-01

A fire characteristics chart is a graph that presents primary related fire behavior characteristics-rate of spread, flame length, fireline intensity, and heat per unit area. It helps communicate and interpret modeled or observed fire behavior. The Fire Characteristics Chart computer program plots either observed fire behavior or values that have been calculated by...

Revealing the radial characteristics of Q-plate generated vortex beams

CSIR Research Space (South Africa)

Sephton, Bereneice

2016-07-01

Full Text Available Q-plates (QP) have become ubiquitous in experiments requiring the generation of vortex beams since its development in 2006. It consequently follows that it is important to characterize the vortex beams created by this geometric-phase optical element...

Research on the Electrical Characteristics of Photovoltaic Arrays and Corresponding MPPT Simulation

Directory of Open Access Journals (Sweden)

Shengming Li

2013-05-01

Full Text Available Photovoltaic cells, as the primary part of a solar photovoltaic system, are a nonlinear DC power supply related to multiple parameters. The demand of increasing the generating efficiency of photovoltaic cells requires having a good understanding of their electrical characteristics. In this study, the mathematical and physical model of the photovoltaic cells was built by the means of Matlab and Simulink based on the internal principles and equivalent circuits of the photovoltaic cells. After the simulation of such practical and versatile model, it’s found that the nonlinear P-V and I-V characteristics of the photovoltaic cells, with the change of sunlight intensity and temperature, could be accurately reflected by this high simulation precision model. Furthermore, the Maximum Power Point Tracking method was proposed using the logical formula dP/dI=0 of the maximum power point of photovoltaic cells. This method can simply and fast implement the tracking for the maximum power point.

Comparison of attitudes between Generation X and Baby Boomer veterinary faculty and residents.

Science.gov (United States)

Freeman, Lisa M; Trower, Cathy A; Tan, Rachael J B; Terkla, Dawn Geronimo

2009-01-01

Understanding the characteristics and preferences of the different generations in the veterinary workforce is important if we are to help optimize current and future veterinary schools and teaching hospitals. The purpose of this study was to compare the attitudes of different generations of veterinary faculty and those of faculty and house officers. A survey administered to faculty and house officers asked respondents to identify their level of agreement with a series of statements addressing work and lifestyle issues and feedback preferences. In addition, the survey included an open-ended question on non-monetary rewards for hard work. Thirty-eight of 48 faculty members (79%) and 45 of 54 house officers (83%) completed the survey. Among faculty, there were no significant differences between the Generation X and Baby Boomer subgroups or between genders. More faculty than house officers responded that delayed gratification is acceptable (p = 0.03) and that it is difficult to balance home and work life (p generations within the faculty group, but a number of significant differences emerged between faculty and house officers. Increased awareness of the importance of balance and rewards for hard work, as well as modification of feedback styles, may be beneficial in teaching and mentoring current and future generations.

Darlington steam generator life assurance program

International Nuclear Information System (INIS)

Jelinski, E.; Dymarski, M.; Maruska, C.; Cartar, E.

1995-01-01

The Darlington Nuclear Generating Station belonging to Ontario Hydro is one of the most modern and advanced nuclear generating stations in the world. Four reactor units each generate 881 net MW, enough to provide power to a major city, and representing approximately 20% of the Ontario grid. The nuclear generating capacity in Ontario represents approximately 60% of the grid. In order to look after this major asset, many proactive preventative and predictive maintenance programs are being put in place. The steam generators are a major component in any power plant. World wide experience shows that nuclear steam generators require specialized attention to ensure reliable operation over the station life. This paper describes the Darlington steam generator life assurance program in terms of degradation identification, monitoring and management. The requirements for chemistry control, surveillance of process parameters, surveillance of inspection parameters, and the integration of preventative and predictive maintenance programs such as water lancing, chemical cleaning, RIHT monitoring, and other diagnostics to enhance our understanding of life management issues are identified and discussed. We conclude that we have advanced proactive activities to avoid and to minimize many of the problems affecting other steam generators. An effective steam generator maintenance program must expand the knowledge horizon to understand life limiting processes and to analyze and synthesize observations with theory. (author)

Steam generator thermal-hydraulics

International Nuclear Information System (INIS)

Inch, W.W.; Scott, D.A.; Carver, M.B.

1980-01-01

This paper discusses a code for detailed numerical modelling of steam generator thermal-hydraulics, and describes related experimental programs designed to promote in-depth understanding of three-dimensional two-phase flow. (auth)

Reactor type choice and characteristics for a small nuclear heat and electricity co-generation plant

International Nuclear Information System (INIS)

Liu Kukui; Li Manchang; Tang Chuanbao

1997-01-01

In China heat supply consumes more than 70 percent of the primary energy resource, which makes for heavy traffic and transportation and produces a lot of polluting materials such as NO x , SO x and CO 2 because of use of the fossil fuel. The utilization of nuclear power into the heat and electricity co-generation plant contributes to the global environmental protection. The basic concept of the nuclear system is an integral type reactor with three circuits. The primary circuit equipment is enclosed in and linked up directly with reactor vessel. The third circuit produces steam for heat and electricity supply. This paper presents basic requirements, reactor type choice, design characteristics, economy for a nuclear co-generation plant and its future application. The choice of the main parameters and the main technological process is the key problem of the nuclear plant design. To make this paper clearer, take for example a double-reactor plant of 450 x 2MW thermal power. There are two sorts of main technological processes. One is a water-water-steam process. Another is water-steam-steam process. Compared the two sorts, the design which adopted the water-water-steam technological process has much more advantage. The system is simplified, the operation reliability is increased, the primary pressure reduces a lot, the temperature difference between the secondary and the third circuits becomes larger, so the size and capacity of the main components will be smaller, the scale and the cost of the building will be cut down. In this design, the secondary circuit pressure is the highest among that of the three circuits. So the primary circuit radioactivity can not leak into the third circuit in case of accidents. (author)

Understanding the Exhibitionary Characteristics of Popular Music Museums

Directory of Open Access Journals (Sweden)

Charles Fairchild

2017-03-01

Full Text Available The literature on the popular music museum has primarily focused on the study of heritage and cultural memory with a secondary focus on tourism. Given the unprecedented expansion of the museum sector worldwide in recent decades, which has produced an increasing number of major museums dedicated to popular music, it is an opportune time to expand this range of analytical concerns. Specifically, the development of popular music museums has not yet been closely examined within the broader historical trajectory of the so-called ‘new museum.’ This article seeks to outline the range of exhibitionary types commonly used in a range of high-profile popular music museums in pursuit of this line of inquiry. The goal is not simply to produce a generic survey or typology of displays, but to place the use of different forms of museum display within the specific historical trajectory that has produced steadily larger numbers of these kinds of museums in recent years. I organize these exhibitionary types into two broad streams of museum exhibition practice implied in the historical survey presented here: a populist-vernacular stream of museum display and an institutional-educational one. I seek to place the exhibitionary practices of contemporary popular music museums in a broader and longer trajectory of similar practices in order to get a more grounded sense of the more important characteristics of these kinds of museums.

Essential Elements for Recruitment and Retention: Generation Y

Science.gov (United States)

Luscombe, Jenna; Lewis, Ioni; Biggs, Herbert C.

2013-01-01

Purpose: Generation Y (Gen Y) is the newest and largest generation entering the workforce. Gen Y may differ from previous generations in work-related characteristics which may have recruitment and retention repercussions. Currently, limited theoretically-based research exists regarding Gen Y's work expectations and goals in relation to…

Understanding Children's Reading Activities: Reading Motivation, Skill and Child Characteristics as Predictors

Science.gov (United States)

McGeown, Sarah P.; Osborne, Cara; Warhurst, Amy; Norgate, Roger; Duncan, Lynne G.

2016-01-01

This study examined the extent to which a range of child characteristics (sex, age, socioeconomic status, reading skill and intrinsic and extrinsic reading motivation) predicted engagement (i.e., time spent) in different reading activities (fiction books, factual books, school textbooks, comics, magazines and digital texts). In total, 791 children…

Heat transfer characteristics and entropy generation for wing-shaped-tubes with longitudinal external fins in cross-flow

Energy Technology Data Exchange (ETDEWEB)

Ahmed, Sayed Ahmed E. Sayed; Mesalhy, Osama M.; Abdelatief, Mohamed A. [Zagazig University, Zagazig (Egypt)

2016-06-15

A numerical study is conducted to clarify heat transfer characteristics, effectiveness and entropy generation for a bundle of wingshaped-tubes attached to Longitudinal fins (LF) at downstream side. The air-side Re{sub a} ranged from 1.8 x 10{sup 3} to 9.7 x 10{sup 3} . The fin height (h{sub f}) and fin thickness (δ) have been changed as: (2 mm <= hf <= 12 mm) and (1.5 mm <= δ <= 3.5 mm). The analysis of entropy generation is based on the principle of minimizing the rate of total entropy generation that includes the generation of entropy due to heat transfer and friction losses. The temperature field around the wing-shaped-tubes with (LF) is predicted using commercial CFD FLUENT 6.3.26 software package. Correlations of Nu{sub a}, St{sub a}, and Bejan number (Be), as well as the irreversibility distribution ratio (Φ) in terms of Re{sub a} and design parameters for the studied bundle are presented. Results indicated that, installing fins with heights from 2 to 12 mm results in an increase in Nu{sub a} from 11 to 36% comparing with that of wing-shaped tubes without fins (NOF). The highest and lowest values of effectiveness(ε) at every value of the considered Re{sub a} range are occurred at hf = 6 mm and (NOF), espectively. The wing-shaped-tubes heat exchanger with hf = 6 mm has the highest values of (ε), efficiency index (η) and area goodness factor (G{sub a}) and also the lowest values of Φ and hence the best performance comparing with other arrangements. The minimum values of Φ are occurred at hf = 6 mm. (Be) decreases with increasing Re{sub a} for all studied hf. The heat transfer irreversibility predominates for (1800 <= Re{sub a} <= 4200) while the opposite is true for (6950 < Re{sub a} <= 9700). δ has negligible effect on Nu{sub a} and heat transfer irreversibility. Comparisons between the experimental and numerical results of the present study and those, previously, obtained for similar available studies showed good agreements.

Managing Generation Y towards Organizational Excellence

OpenAIRE

Uduwawela, Shehani Romesha

2015-01-01

The workforce today comprises of several distinctive generations working along together, with Generation Y (Gen Y) being the latest entry to the workplace. This latest entrance of employees has raised concern from organizations owing to their diverse work ethics, characteristics, and traits, which are significantly different to the previous generational cohorts. It is reported that Gen Ys enter the workforce with high expectations and are subjected to influence from varied factors that impact...

Arc damage characteristics of inter-anode insulators in MHD generator

International Nuclear Information System (INIS)

Kato, Ken; Takano, Kiyonami

1990-01-01

The inter-anode arc caused by a Hall field is driven by a magnetic field into the anode-wall in an MHD generator, which limits the lifetime and performance of the generator. The arc damage to inter-anode insulators of an MHD generator has been studied experimentally, in order to obtain basic data for the design of the inter-anode insulation. The experiment was conducted using a pair of electrodes with an insulator between them. Arc currents was supplied from a DC power source and magnetic field was applied perpendicular to the arc current. Experimental parameters are the insulator thickness, arc current, magnetic field and insulator materials. Quartz glass, boron nitride, magnesia, alumina, silicon carbide, silicon nitride etc. were tested and evaluated. The following conclusions are evident from the experiments. Boron nitride and quartz glass are the most promising inter-anode insulators. Boron nitride has a higher arc voltage and longer cutting time than quartz glass, and it is the best material. Cutting time is approximately proportional to the -0.4 th power of the magnetic field. Loss of insulator is approximately proportional to the 0.7 th power of the arc current. The arc voltage increases linearly with the inter anode gap length. It also increases with magnetic field, but decreases with increase of arc current. An equation which approximates to such relations of arc voltage versus inter-anode gap length, arc current and magnetic field has been obtained. The standard deviation of the error of this equation is 12 % for boron nitride and 15 % for quartz glass. (author)

An introduction to technetium-99m generators

International Nuclear Information System (INIS)

Abrashkin, S.

1984-02-01

The role played by technetium-99m generators in diagnostic medicine, their physical and chemical fundamentals and their main technical characteristics are discussed. This report is intended as a general introduction to a group of reports which summarize the work done on the development and production of the generators, and research on the chemical and physical aspects of the generator systems

The characteristics of successful entrepreneurs

OpenAIRE

Pokrajčić Dragana M.

2004-01-01

This paper examines the economic, psychological and social-behavioral theories of the entrepreneur in order to determine the characteristics of a successful entrepreneur. The major contribution of economic theories of the entrepreneur is better understanding of the entrepreneur and his/her role in economic development. The psychological characteristic theory of entrepreneur argues that successful entrepreneurs possess certain personality traits that mark them out as special, and tries to dete...

Experimental study of exhaust noise generated by pulsating flow downstream of pipe end; Myakudoryu ni yori yukisareru kantanbu karyu ni okeru haiki soon no jikkenteki kenkyu

Energy Technology Data Exchange (ETDEWEB)

Higashiyama, J; Iwamoto, J [Tokyo Denki University, Tokyo (Japan)

1997-10-01

A experimental study was carried out for the emissoin of the exhaust noise from an open end of the pipe generated by the pulsating flow in the pipe. The pressure histories along the pipe, the exhaust noise and visualized the flow field downstream of the pipe end were obtained. And a characteristic of frequency for the exhaust noise was examined, using Wigner distribution (WD). A relation between the pulsating flow in the pipe and the exhaust noise was important for understanding the mechanism of the exhaust noise generation. 4 refs., 8 figs., 1 tab.

Plasma X-ray sources powered by megajoule magnetocumulative generators

Energy Technology Data Exchange (ETDEWEB)

Popkov, N F; Averchenkov, V Ya; Pikar` , A S; Ryaslov, E A; Kargin, V I; Lazarev, S A; Borodkov, V V; Nazarenko, S T; Makartsev, G F [All-Russian Research Inst. of Experimental Physics, Sarov (Russian Federation). Russian Federal Nuclear Center

1997-12-31

Experiments using magnetocumulative generators (MCGs) were performed to power three different types of high-energy-density plasma discharges suitable for intense x-ray generation. These included the H-pressed discharge, the capillary z-pinch, and the {theta}-pinch. The MCGs were operated both with and without plasma opening switches. The characteristic currents were approximately 10 MA and characteristic time scales approximately 1 {mu}s. (author). 7 figs., 3 refs.

Theoretical description of high-order harmonic generation in solids

International Nuclear Information System (INIS)

Kemper, A F; Moritz, B; Devereaux, T P; Freericks, J K

2013-01-01

We consider several aspects of high-order harmonic generation in solids: the effects of elastic and inelastic scattering, varying pulse characteristics and inclusion of material-specific parameters through a realistic band structure. We reproduce many observed characteristics of high harmonic generation experiments in solids including the formation of only odd harmonics in inversion-symmetric materials, and the nonlinear formation of high harmonics with increasing field. We find that the harmonic spectra are fairly robust against elastic and inelastic scattering. Furthermore, we find that the pulse characteristics can play an important role in determining the harmonic spectra. (paper)

The characteristics of a pneumatic muscle

Directory of Open Access Journals (Sweden)

Pietrala Dawid

2017-01-01

Full Text Available The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics. It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics. It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics. The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

The characteristics of a pneumatic muscle

Science.gov (United States)

Pietrala, Dawid

The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics). It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics). The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

Parallel Polarization State Generation.

Science.gov (United States)

She, Alan; Capasso, Federico

2016-05-17

The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security.

Financing Distributed Generation

International Nuclear Information System (INIS)

Walker, A.

2001-01-01

This paper introduces the engineer who is undertaking distributed generation projects to a wide range of financing options. Distributed generation systems (such as internal combustion engines, small gas turbines, fuel cells and photovoltaics) all require an initial investment, which is recovered over time through revenues or savings. An understanding of the cost of capital and financing structures helps the engineer develop realistic expectations and not be offended by the common requirements of financing organizations. This paper discusses several mechanisms for financing distributed generation projects: appropriations; debt (commercial bank loan); mortgage; home equity loan; limited partnership; vendor financing; general obligation bond; revenue bond; lease; Energy Savings Performance Contract; utility programs; chauffage (end-use purchase); and grants. The paper also discusses financial strategies for businesses focusing on distributed generation: venture capital; informal investors (''business angels''); bank and debt financing; and the stock market

Proposal of electric power generation from generators to water edge in the region of Sarapiqui

International Nuclear Information System (INIS)

Rodriguez Fallas, Cindy Veronica

2013-01-01

A proposed electric power generation is developed from generators to water edge in the region of Sarapiqui. The environmental characteristics, such as the hydrological network, hydrogeology, soil type, life zones, climatology, precipitation, temperature, evapotranspiration and water supply and demand, of rivers crossed by basin in the region of Sarapiqui, are determined by bibliographic consultations to implement the proposal. The most recent production statistics of the electric subsector of Costa Rica are described to reveal the growing annual demand and need for satisfaction. The zone of Sarapiqui is diagnosed as the right place to allow the generation of electric power from generators to water edge [es

Renewable energies for power generation

International Nuclear Information System (INIS)

Freris, L.; Infield, D.

2009-01-01

Power generation from renewable energy sources is different from power generation from classical energies (nuclear, thermal..). Therefore, the integration into the grid of the electricity supplied by renewable sources requires a deep thinking. The reason is that these power sources are controlled by variable elements, like wind, water and sun, which condition production. This book deals with the following aspects in detail: characteristics of classical and intermittent generators; grid balancing between supply and demand; conversion methods of renewable energies into electricity; power systems; privatizing of power generation and birth of new markets, in particular the 'green' power market; development of renewable energies thanks to technical advances. It gives a comprehensive overview of the present day available renewable energy sources for power generation. (J.S.)

Analysis of the Vortex Street Generated at the Core-Bypass Lip of a Jet-Engine Nozzle

Science.gov (United States)

Nogueira, José; Legrand, Mathieu; Nauri, Sara; Rodríguez, Pedro A.; Lecuona, Antonio

The reduction of the noise generated by jet-engine aircrafts is of growing concern in the present society. A better understanding of the aircraft noise production and the development of predictive tools is of great interest. Within this framework, the CoJeN (Coaxial Jet Noise) European Project includes the measurement of the flow field and the noise generated by typical turbofan jet-engine nozzles. One of the many aspects of interest is the occasional presence of acoustic tones of a defined frequency, symptomatic of the presence of quasiperiodic coherent structures within the flow. This chapter analyzes the characteristics of a vortex street in the core-bypass lip of one of the nozzles under study. The measurements were made by means of advanced PIV techniques within the above-mentioned project.

Understanding leader representations: Beyond implicit leadership theory

OpenAIRE

Knee, Robert Everett

2006-01-01

The purpose of the present study was to establish evidence for the suggested integration of the theories of connectionism and leadership. Recent theoretical writings in the field of leadership have suggested that the dynamic representations generated by the connectionist perspective is an appropriate approach to understanding how we perceive leaders. Similarly, implicit leadership theory (ILT) explains that our cognitive understandings of leaders are based on a cognitive structure that we u...

The pig gut microbial diversity: Understanding the pig gut microbial ecology through the next generation high throughput sequencing.

Science.gov (United States)

Kim, Hyeun Bum; Isaacson, Richard E

2015-06-12

The importance of the gut microbiota of animals is widely acknowledged because of its pivotal roles in the health and well being of animals. The genetic diversity of the gut microbiota contributes to the overall development and metabolic needs of the animal, and provides the host with many beneficial functions including production of volatile fatty acids, re-cycling of bile salts, production of vitamin K, cellulose digestion, and development of immune system. Thus the intestinal microbiota of animals has been the subject of study for many decades. Although most of the older studies have used culture dependent methods, the recent advent of high throughput sequencing of 16S rRNA genes has facilitated in depth studies exploring microbial populations and their dynamics in the animal gut. These culture independent DNA based studies generate large amounts of data and as a result contribute to a more detailed understanding of the microbiota dynamics in the gut and the ecology of the microbial populations. Of equal importance, is being able to identify and quantify microbes that are difficult to grow or that have not been grown in the laboratory. Interpreting the data obtained from this type of study requires using basic principles of microbial diversity to understand importance of the composition of microbial populations. In this review, we summarize the literature on culture independent studies of the pig gut microbiota with an emphasis on its succession and alterations caused by diverse factors. Copyright © 2015 Elsevier B.V. All rights reserved.

Generation of the SCN1A epilepsy mutation in hiPS cells using the TALEN technique

Science.gov (United States)

Chen, Wanjuan; Liu, Jingxin; Zhang, Longmei; Xu, Huijuan; Guo, Xiaogang; Deng, Sihao; Liu, Lipeng; Yu, Daiguan; Chen, Yonglong; Li, Zhiyuan

2014-06-01

Human induced pluripotent stem cells (iPSC) can be used to understand the pathological mechanisms of human disease. These cells are a promising source for cell-replacement therapy. However, such studies require genetically defined conditions. Such genetic manipulations can be performed using the novel Transcription Activator-Like Effector Nucleases (TALENs), which generate site-specific double-strand DNA breaks (DSBs) with high efficiency and precision. Combining the TALEN and iPSC methods, we developed two iPS cell lines by generating the point mutation A5768G in the SCN1A gene, which encodes the voltage-gated sodium channel Nav1.1 α subunit. The engineered iPSC maintained pluripotency and successfully differentiated into neurons with normal functional characteristics. The two cell lines differ exclusively at the epilepsy-susceptibility variant. The ability to robustly introduce disease-causing point mutations in normal hiPS cell lines can be used to generate a human cell model for studying epileptic mechanisms and for drug screening.

Sleep Spindle Characteristics in Children with Neurodevelopmental Disorders and Their Relation to Cognition

Science.gov (United States)

Wise, Merrill S.

2016-01-01

Empirical evidence indicates that sleep spindles facilitate neuroplasticity and “off-line” processing during sleep, which supports learning, memory consolidation, and intellectual performance. Children with neurodevelopmental disorders (NDDs) exhibit characteristics that may increase both the risk for and vulnerability to abnormal spindle generation. Despite the high prevalence of sleep problems and cognitive deficits in children with NDD, only a few studies have examined the putative association between spindle characteristics and cognitive function. This paper reviews the literature regarding sleep spindle characteristics in children with NDD and their relation to cognition in light of what is known in typically developing children and based on the available evidence regarding children with NDD. We integrate available data, identify gaps in understanding, and recommend future research directions. Collectively, studies are limited by small sample sizes, heterogeneous populations with multiple comorbidities, and nonstandardized methods for collecting and analyzing findings. These limitations notwithstanding, the evidence suggests that future studies should examine associations between sleep spindle characteristics and cognitive function in children with and without NDD, and preliminary findings raise the intriguing question of whether enhancement or manipulation of sleep spindles could improve sleep-dependent memory and other aspects of cognitive function in this population. PMID:27478646

Operational characteristics of the high flux plasma generator magnum-PSI

NARCIS (Netherlands)

Van Eck, H.J.N.; Abrams, T.; Van Den Berg, M.A.; Brons, S.D.N.; Van Eden, G.G.; Jaworski, M.A.; Kaita, R.; Van Der Meiden, H.J.; Morgan, T.W.; van de Pol, Marc J.; Scholten, J.; Smeets, P.H.M.; De Temmerman, G.; De Vries, P.C.; Zeijlmans Van Emmichoven, P.A.

2014-01-01

In Magnum-PSI (MAgnetized plasma Generator and NUMerical modeling for Plasma Surface Interactions), the high density, low temperature plasma of a wall stabilized dc cascaded arc is confined to a magnetized plasma beam by a quasi-steady state axial magnetic field up to 1.3 T. It aims at conditions

Understanding quantum physics; Verstehen in der Quantenphysik

Energy Technology Data Exchange (ETDEWEB)

Spillner, Vera

2011-07-01

This thesis presents a bundle definition for 'scientific understanding' through which the empirically equivalent interpretations of quantum mechanics can be evaluated with respect to the understanding they generate. The definition of understanding is based on a sufficient and necessary criterion, as well as a bundle of conditions - where a theory can be called most understandable whenever it fulfills the highest number of bundle criteria. Thereby the definition of understanding is based on the one hand on the objective number of criteria a theory fulfills, as well as, on the other hand, on the individual's preference of bundle criteria. Applying the definition onto three interpretations of quantum mechanics, the interpretation of David Bohm appears as most understandable, followed by the interpretation of Tim Maudlin and the Kopenhagen interpretation. These three interpretations are discussed in length in my thesis. (orig.)

Vulnerability-specific stress generation: An examination of negative cognitive and interpersonal styles

Science.gov (United States)

Liu, Richard T.; Alloy, Lauren B.; Mastin, Becky M.; Choi, Jimmy Y.; Boland, Elaine M.; Jenkins, Abby L.

2014-01-01

Although there is substantial evidence documenting the stress generation effect in depression (i.e., the tendency for depression-prone individuals to experience higher rates of life stress to which they contribute), additional research is required to advance current understanding of the specific types of dependent stress (i.e., events influenced by characteristics and attendant behaviors of the individual) relevant to this effect. The present study tested an extension of the stress generation hypothesis, in which the content of dependent stress that is produced by depression-prone individuals is contingent upon, and matches, the nature of their particular vulnerabilities. This extension was tested within the context of two cognitive models (i.e., hopelessness theory [Abramson, Metalsky, & Alloy, 1989] and Cole’s [1990, 1991] competency-based model) and two interpersonal models (i.e., Swann’s [1987] self-verification theory and Coyne’s [1976] interpersonal theory) of depression. Overall, support was obtained for vulnerability-specific stress generation. Specifically, in analyses across vulnerability domains, evidence of stress-generation specificity was found for all domain-specific cognitive vulnerabilities except self-perceived social competence. The within-domain analyses for cognitive vulnerabilities produced more mixed results, but were largely supportive. Additionally, excessive reassurance-seeking was specifically predictive of dependent stress in the social domain, and moderated, but did not mediate, the relation between negative inferential styles overall and in the interpersonal domain and their corresponding generated stress. Finally, no evidence was found for a stress generation effect with negative feedback-seeking. PMID:24679143

Performance and optimum characteristics by finite element analysis of a coreless ironless electric generator for low wind density power generation

Science.gov (United States)

Razali, Akhtar; Rahman, Fadhlur; Leong, Yap Wee; Razali Hanipah, Mohd; Azri Hizami, Mohd

2018-04-01

Cogging is an attraction of magnetism between permanent magnets and soft ironcore lamination in a conventional electric ironcore generator. The presence of cog in the generator is seen somehow restricted the application of the generator in an application where low rotational torque is required. Cog torque requires an additional input power to overcome, hence became one of the power loss sources. With the increasing of power output, the cogging is also proportionally increased. This leads to the increasing of the supplied power of the driver motor to overcome the cog. Therefore, this research is embarked to study fundamentally about the possibility of removing ironcore lamination in an electric generator. This research deals with removal of ironcore lamination in electric generator to eliminate cog torque. A confinement technique is proposed to confine and focus magnetic flux by introducing opposing permanent magnets arrangement. There were several parameters analysed using the JMAG Designer. Transient response analysis was used in the JMAG Designer. The parameters analysed were the number of coil turns per phase, gap distance between the magnet pairs as well as the magnet grade used. These few parameters were analysed under the open circuit condition. Results showed with the increasing of gap distance, output voltage produced decreased. The increment of number of turns in the coils and higher magnet grades used, these increased the output voltage of the generator. With the help of these results, a reference point is established to get optimum design parameter for fabrication of working prototype.

Examining of solid waste generation and community awareness between city center and suburban area in Medan City, Indonesia

Science.gov (United States)

Khair, H.; Putri, C. N.; Dalimunthe, R. A.; Matsumoto, T.

2018-02-01

Municipal solid waste (MSW) management is still an issue in many cities in Indonesia including Medan. Understanding the waste generation, its characteristic and communities involvement could provide effective solid waste management. This research compares waste generation from people who live in the city center and suburban area. The research also examines the willingness and participation of community about environmental aspect, especially solid waste management. The method of waste generation used Indonesian Nasional Standard 19-3964-1994. The city center generates 0.295 kg/person/day of solid waste and 0.180 kg/person/day for suburbs. The result showed that there are the common amount of waste compositions between the city center and suburban area. The majority waste composition was an organic fraction. Questionnaires were distributed to examine the community awareness. The descriptive statistic used to analyze the data. The result showed that people living in the city center are slightly higher in community awareness than in the suburb. This paper highlights that area of living could give some effect to solid waste generation, waste composition and rate of awareness.

Characteristics of Millennial Students at a Two-Year College

Science.gov (United States)

Fenske, Susanne Kelly

2011-01-01

The purpose of this research is to describe the degree to which Millennial students who attend two-year colleges exhibit the characteristics of the seven Millennial generation characteristics. Howe and Strauss (2007) purport that the Millennials exhibit seven key characteristics in their behavior: Special, Sheltered, Confident, Team-oriented,…

Short irradiation time characteristics of the inverter type X-ray generator

International Nuclear Information System (INIS)

Miyazaki, Shigeru; Hara, Takamitu; Matutani, Kazuo; Saito, Kazuhiko.

1994-01-01

The linearity of the X-ray output is an important factor in radiography. It is a composite of the linearities of the X-ray tube voltage, the X-ray tube current, and the exposure time. This paper focuses on the linearity of exposure time. Non-linearity of the X-ray output for short-time exposure became a problem when the three-phase X-ray generator was introduced. This paper describes the inverter-type X-ray generator, which is expected to become predominant in the future. Previously, we investigated X-ray output linearity during short-time exposure using the technique of dynamic study. In this paper, we describe the application of a digital memory and a personal computer to further investigation. The non-linearity of the X-ray output was caused by irregular waveforms of the X-ray tube voltage found at the rise time and the fall time. When the rise time was about 0.6 ms, the non-linearity was about 2%, which is negligibly small. The non-linearity due to the fall time of the X-ray tube varied greatly according to the X-ray tube current. For the minimum irradiation time of 1 ms, 4% to 27% of the non-linearity was attributable to the fall time. The main cause was the stray capacitance of the X-ray high-voltage cables. When the X-ray tube current exceeded 400 mA, the rise time was almost equal to the fall time, and the problem did not occur. Consequently, the ideal generator should have a fall time which is equal to the rise time of the X-ray tube voltage. Strictly speaking, such a generator should have rectangular waveforms. (author)

Understand the Design Requirement in Companies

DEFF Research Database (Denmark)

Li, Xuemeng; Ahmed-Kristensen, Saeema

2015-01-01

requirements can lead to inappropriate products (Hall, et al., 2002). Understanding the nature of design requirements and the sources, from where they can or should be generated, is critical to before developing methods and processes to support this process. Requirement Engineering research, originated from...

Advances in understanding hypopituitarism

OpenAIRE

Stieg, Mareike R.; Renner, Ulrich; Stalla, G?nter K.; Kopczak, Anna

2017-01-01

The understanding of hypopituitarism has increased over the last three years. This review provides an overview of the most important recent findings. Most of the recent research in hypopituitarism has focused on genetics. New diagnostic techniques like next-generation sequencing have led to the description of different genetic mutations causative for congenital dysfunction of the pituitary gland while new molecular mechanisms underlying pituitary ontogenesis have also been described. Furtherm...

Fluisd elastic instability and fretting-wear characteristics of steam generator helical tubes subjected to single-phase external flow and two-phase internal flow

International Nuclear Information System (INIS)

Jo, Jong Chull; Jhung, Myung Jo; Kim, Woong Sik; Kim, Hho Jung

2004-01-01

This study investigates the fluid elastic instability characteristics of steam generator (SG) helical type tubes and the safety assessment of the potential for fretting-wear damages caused by foreign object in operating nuclear power plants. The thermal-hydraulic conditions of both tube side and shell side flow fields are predicted by a general purpose computational fluid dynamics code employing the finite volume element modeling. To get the natural frequency, corresponding mode shape and participation factor, modal analyses are performed for helical type tubes with various conditions. Special emphases are on the effects of coil diameter and the number of turns on the modal and instability characteristics of tubes, which are expressed in terms of the natural frequency, corresponding mode shape and stability ratio. Also, the wear rate of helical type tube caused by foreign object is calculated using the Archard formula and the remaining life of the tube is predicted, and discussed in this study is the effect of the flow velocity and vibration of the tube on the remaining life of the tube. In addition, addressed is the effect of the external pressure on the vibration and fretting wear characteristics of the tube

Understanding technology adoption through individual and context characteristics: the case of HDTV

NARCIS (Netherlands)

Baaren, Eva; van de Wijngaert, Lidwien; Huizer, E.

2011-01-01

Technology adoption research has a tradition of using and improving Davis' (1989) “Technology Acceptance Model” (TAM) and extended versions of it. This article suggests a break with this tradition by showing that the TAM is limited in its understanding of technology adoption. Two alternative

Dynamic Characteristics of Positive Pulsed Dielectric Barrier Discharge for Ozone Generation in Air

Science.gov (United States)

Wei, Linsheng; Peng, Bangfa; Li, Ming; Zhang, Yafang; Hu, Zhaoji

2016-02-01

A comprehensive dynamic model consisting of 66 reactions and 24 species is developed to investigate the dynamic characteristics of ozone generation by positive pulsed dielectric barrier discharge (DBD) using parallel-plate reactor in air. The electron energy conservation equation is coupled to the electron continuity equation, the heavy species continuity equation, and Poisson's equation for a better description. The reliability of the model is experimentally confirmed. The model can be used to predict the temporal and spatial evolution of species, as well as streamer propagation. The simulation results show that electron density increases nearly exponentially in the direction to the anode at the electron avalanche. Streamer propagation velocity is about 5.26 × 104 m/s from anode to cathode in the simulated condition. The primary positive ion, negative ion, and excited species are O2+, O3- and O2(1Δg) in pulsed DBD in air, respectively. N2O has the largest density among nitrogen oxides. e and N2+ densities in the streamer head increase gradually to maximum values with the development of the streamer. Meanwhile, the O2+, O, O3, N2(A3Σ) and N2O densities reach maximum values in the vicinity of the anode. supported by National Natural Science Foundation of China (Nos. 51366012 and 11105067), Jiangxi Province Young Scientists (Jinggang Star) Cultivation Plan of China (No. 20133BCB23008), Natural Science Foundation of Jiangxi, China (No. 20151BAB206047) and Jiangxi Province Higher School Science and Technology Landing Plan of China (No. KJLD-14015)

Financing Distributed Generation

Energy Technology Data Exchange (ETDEWEB)

Walker, A.

2001-06-29

This paper introduces the engineer who is undertaking distributed generation projects to a wide range of financing options. Distributed generation systems (such as internal combustion engines, small gas turbines, fuel cells and photovoltaics) all require an initial investment, which is recovered over time through revenues or savings. An understanding of the cost of capital and financing structures helps the engineer develop realistic expectations and not be offended by the common requirements of financing organizations. This paper discusses several mechanisms for financing distributed generation projects: appropriations; debt (commercial bank loan); mortgage; home equity loan; limited partnership; vendor financing; general obligation bond; revenue bond; lease; Energy Savings Performance Contract; utility programs; chauffage (end-use purchase); and grants. The paper also discusses financial strategies for businesses focusing on distributed generation: venture capital; informal investors (''business angels''); bank and debt financing; and the stock market.

Comparative funding consequences of large versus small gas-fired power generation units

International Nuclear Information System (INIS)

Johnson, N.G.

1995-01-01

Gas producers are increasingly looking to privately-owned gas-fired power generation as a major growth market to support the development of new fields being discovered across Australia. Gas-fired generating technology is more environmentally friendly than coal-fired power stations, has lower unit capital costs and has higher efficiency levels. With the recent downward trends in gas prices for power generation (especially in Western Australia) it is likely that gas will indeed be the consistently preferred fuel for generation in Australia. Gas producers should be sensitive to the different financial and risk characteristics of the potential market represented by large versus small gas-fired private power stations. These differences are exaggerated by the much sharper focus given by the private sector to quantify risk and to its allocation to the parties best able to manage it. The significant commercial differences between classes of generation projects result in gas producers themselves being exposed to diverging risk profiles through their gas supply contracts with generating companies. Selling gas to larger generation units results in gas suppliers accepting proportionately (i.e. not just prorata to the larger installed capacity) higher levels of financial risk. Risk arises from the higher probability of a project not being completed, from the increased size of penalty payments associated with non-delivery of gas and from the rising level of competition between gas suppliers. Gas producers must fully understand the economics and risks of their potential electricity customers and full financial analysis will materially help the gas supplier in subsequent commercial gas contract negotiations. (author). 1 photo

Arc generators of low-temperature plasma

International Nuclear Information System (INIS)

Krolikowski, Cz.; Niewiedzial, R.; Siwiec, J.

1979-01-01

This paper is a review of works concerning investigation and use of low-temperature plasma in arc plasma generators made in Electric Power Institute of PP. There are discussed: analytical approach to a problem of volt-current and operational characteristics of DC arc plasma generators, determination of limits of their stable work and possibilities of their use to technological aims. (author)

Understanding community traits - understanding public concerns

International Nuclear Information System (INIS)

Wlodarczyk, T.

2003-01-01

No two communities are alike. Therefore, one should not expect that public concerns and socio-economic effects of a proposed undertaking would be the same everywhere. Public concerns and the potential for social and economic effects of nuclear waste management facilities in one community will be different from those in another because communities differ in their fundamental sociological and economic traits. Research and experience with various types of nuclear and hazardous waste management facilities, generating stations and other energy developments across Canada and the United States indicate that an analysis of only a few key community traits can yield a more thorough understanding of the ways in which a community might perceive and respond to a project, the kinds of concerns that might dominate the public agenda, and the types of socio-economic effects that will be of primary concern. (author)

A Framework for Understanding and Generating Integrated Solutions for Residential Peak Energy Demand

Science.gov (United States)

Buys, Laurie; Vine, Desley; Ledwich, Gerard; Bell, John; Mengersen, Kerrie; Morris, Peter; Lewis, Jim

2015-01-01

Supplying peak energy demand in a cost effective, reliable manner is a critical focus for utilities internationally. Successfully addressing peak energy concerns requires understanding of all the factors that affect electricity demand especially at peak times. This paper is based on past attempts of proposing models designed to aid our understanding of the influences on residential peak energy demand in a systematic and comprehensive way. Our model has been developed through a group model building process as a systems framework of the problem situation to model the complexity within and between systems and indicate how changes in one element might flow on to others. It is comprised of themes (social, technical and change management options) networked together in a way that captures their influence and association with each other and also their influence, association and impact on appliance usage and residential peak energy demand. The real value of the model is in creating awareness, understanding and insight into the complexity of residential peak energy demand and in working with this complexity to identify and integrate the social, technical and change management option themes and their impact on appliance usage and residential energy demand at peak times. PMID:25807384

The importance of understanding military culture.

Science.gov (United States)

Hall, Lynn K

2011-01-01

Social workers can make a significant contribution to military service members and their families, but first it is essential that the worldview, the mindset, and the historical perspective of life in the military are understood. Unless we understand how the unique characteristics of the military impact the service members and their families, we cannot work effectively with them. In addition, unless we understand their language, their structure, why they join, their commitment to the mission, and the role of honor and sacrifice in military service, we will not be able to adequately intervene and offer care to these families.

Characteristics of radioactive waste streams generated in HTGR fuel reprocessing

International Nuclear Information System (INIS)

Lin, K.H.

1976-01-01

Results are presented of a study concerned with identification and characterization of radioactive waste streams from an HTGR fuel reprocessing plant. Approximate quantities of individual waste streams as well as pertinent characteristics of selected streams have been estimated. Most of the waste streams are unique to HTGR fuel reprocessing. However, waste streams from the solvent extraction system and from the plant facilities do not differ greatly from the corresponding LWR fuel reprocessing wastes

Proceedings of steam generator sludge deposition in recirculating and once through steam generator upper tube bundle and support plates

International Nuclear Information System (INIS)

Baker, R.L.; Harvego, E.A.

1992-01-01

The development of remedial measures of shot peening have given nuclear utilities viable measures to address primary water stress corrosion cracking to extend steam generator life. The nuclear utility industry is now faced with potential replacement of steam generators in nuclear power plants due to stress corrosion cracking and intergranular attach in crevice locations on the secondary side of steam generators at tube support plates and at the crevice at the top of the tube sheet. Significant work has been done on developing and understanding of the effects of sludge buildup on the corrosion process at these locations. This session was envisioned to provide a forum for the development of an understanding of the mechanisms which control the transport and deposition of sludge on the secondary side of steam generators. It is hoped that this information will aid utilities in monitoring the progression of fouling of these crevices by further knowledge in where to look for the onset of support plate crevice fouling. An understanding of the progression of fouling from upper tube support plates to those lower in the steam generator where higher temperatures cause the corrosion process to initiate first can aid the nuclear utility industry in developing remedial measures for this condition and in providing a forewarning of when to apply such remedial measures

Infrared Supercontinuum Generation in Soft-glass Fibers

DEFF Research Database (Denmark)

Agger, Christian

This Ph.D.-project presents numerical simulations of supercontinuum (SC) generation in optical fiber laser systems based on various soft-glass materials. Extensive numerical modeling is performed in order to understand and characterize the generated SC. This includes a review of the generalized...

STARTER-GENERATOR SYSTEM FOR AUXILIARY POWER UNIT

Directory of Open Access Journals (Sweden)

A. V. Levin

2017-01-01

Full Text Available The article presents a starter-generator system for an auxiliary power unit of an aircraft. A feature of the presented system is the use of a synchronous generator with excitation from permanent magnets and a semiconductor converter. The main problem of the system is the generation of electric energy of an aircraft on the basis of a synchronous generator with excitation from permanent magnets is the absence of the possibility of regulating the voltage and frequency of electrical energy, in this connection, a semiconductor converter that ensures the conversion of generated electric energy with significant mass-dimensions characteristics.The article proposes an approach to designing a starter-generator system with a parallel connection of a synchronous generator with excitation from permanent magnets and a semiconductor converter. This approach makes it possible to significantly reduce the part of the electrical energy that needs to be converted, as a consequence, the semiconductor converter has significantly smaller mass-and-batch characteristics.In the article the modes of generation of electric energy and the starter mode of operation of the starter-generator system are considered in detail, the circuit realization of the semiconductor converter is shown. A scheme for replacing one phase of the system for generating electric energy and calculating electric parameters is presented.The possibility of creating a highly efficient starter-generator system based on a synchronous generator with excitation from permanent magnets and a semiconductor converter for an auxiliary power plant of aircrafts is shown. Structural and basic schemes for constructing a system for generating electrical energy are proposed. The approach to the choice of rational circuit solutions is substantiated, basic estimates of the electrical parameters of the system are obtained. The possibility of achieving a specific mass of a semiconductor converter for synchronous

Characteristics of SnO{sub 2}-based {sup 68}Ge/{sup 68}Ga generator and aspects of radiolabelling DOTA-peptides

Energy Technology Data Exchange (ETDEWEB)

Blois, Erik de; Chan, Ho Sze [Department of Nuclear Medicine, Erasmus MC Rotterdam, Rotterdam (Netherlands); Naidoo, Clive; Prince, Deidre [iThemba Labs, Somerset West, Republic of South Africa (South Africa); Krenning, Eric P. [Department of Nuclear Medicine, Erasmus MC Rotterdam, Rotterdam (Netherlands); Department of Internal Medicine, Erasmus MC Rotterdam, Rotterdam (Netherlands); Breeman, Wouter A.P., E-mail: w.a.p.breeman@erasmusmc.n [Department of Nuclear Medicine, Erasmus MC Rotterdam, Rotterdam (Netherlands)

2011-02-15

Objectives: PET scintigraphy with {sup 68}Ga-labelled analogs is of increasing interest in Nuclear Medicine and performed all over the world. Here we report the characteristics of the eluate of SnO{sub 2}-based {sup 68}Ge/{sup 68}Ga generators prepared by iThemba LABS (Somerset West, South Africa). Three purification and concentration techniques of the eluate for labelling DOTA-TATE and concordant SPE purifications were investigated. Methods: Characteristics of 4 SnO{sub 2}-based generators (range 0.4-1 GBq {sup 68}Ga in the eluate) and several concentration techniques of the eluate (HCl) were evaluated. The elution profiles of SnO{sub 2}-based {sup 68}Ge/{sup 68}Ga generators were monitored, while [HCl] of the eluens was varied from 0.3-1.0 M. Metal ions and sterility of the eluate were determined by ICP. Fractionated elution and concentration of the {sup 68}Ga eluate were performed using anion and cation exchange. Concentrated {sup 68}Ga eluate, using all three concentration techniques, was used for labelling of DOTA-TATE. {sup 68}Ga-DOTA-TATE-containing solution was purified and RNP increased by SPE, therefore also 11 commercially available SPE columns were investigated. Results: The amount of elutable {sup 68}Ga activity varies when the concentration of the eluens, HCl, was varied, while {sup 68}Ge activity remains virtually constant. SnO{sub 2}-based {sup 68}Ge/{sup 68}Ga generator elutes at 0.6 M HCl >100% of the {sup 68}Ga activity at calibration time and {+-}75% after 300 days. Eluate at discharge was sterile and Endotoxins were <0.5 EU/mL, RNP was always <0.01%. Metal ions in the eluate were <10 ppm (in total). Highest desorption for anion purification was obtained with the 30 mg Oasis WAX column (>80%). Highest desorption for cation purification was obtained using a solution containing 90% acetone at increasing molarity of HCl, resulted in a {sup 68}Ga desorption of 68{+-}8%. With all {sup 68}Ge/{sup 68}Ga generators and for all 3 purification methods a

Characteristics of manipulative in mathematics laboratory

Science.gov (United States)

Istiandaru, A.; Istihapsari, V.; Prahmana, R. C. I.; Setyawan, F.; Hendroanto, A.

2017-12-01

A manipulative is a teaching aid designed such that students could understand mathematical concepts by manipulating it. This article aims to provide an insight to the characteristics of manipulatives produced in the mathematics laboratory of Universitas Ahmad Dahlan, Indonesia. A case study was conducted to observe the existing manipulatives produced during the latest three years and classified the manipulatives based on the characteristics found. There are four kinds of manipulatives: constructivism manipulative, virtual manipulative, informative manipulative, and game-based manipulative. Each kinds of manipulative has different characteristics and impact towards the mathematics learning.

User-generated content? Get Serious! Understanding the interactions between organizations and customers on social media

NARCIS (Netherlands)

Moser, C.; van Eijkeren, A

2016-01-01

This study examines interactions between customers and organisations on social media by investigating how user-generated content influences interactions between organisations and customers on social media. In compliance with existing perspectives on user-generated content, a total of seven

The guitar chord-generating algorithm based on complex network

Science.gov (United States)

Ren, Tao; Wang, Yi-fan; Du, Dan; Liu, Miao-miao; Siddiqi, Awais

2016-02-01

This paper aims to generate chords for popular songs automatically based on complex network. Firstly, according to the characteristics of guitar tablature, six chord networks of popular songs by six pop singers are constructed and the properties of all networks are concluded. By analyzing the diverse chord networks, the accompaniment regulations and features are shown, with which the chords can be generated automatically. Secondly, in terms of the characteristics of popular songs, a two-tiered network containing a verse network and a chorus network is constructed. With this network, the verse and chorus can be composed respectively with the random walk algorithm. Thirdly, the musical motif is considered for generating chords, with which the bad chord progressions can be revised. This method can make the accompaniments sound more melodious. Finally, a popular song is chosen for generating chords and the new generated accompaniment sounds better than those done by the composers.

Mathematical modeling of a fast-breeder-reactor generating unit

International Nuclear Information System (INIS)

Kim, V.E.; Golovach, E.A.; Senkin, V.I.

1984-01-01

Dynamics equations are given for a reactor, intermediate heat exchanger, steam generator, and turbogenerator. The dynamic characteristics of the generating unit are described when perturbations occur in grid frequency, turbine valves, and feedwater consumption

Generation and propagation characteristics of a localized hollow beam

Science.gov (United States)

Xia, Meng; Wang, Zhizhang; Yin, Yaling; Zhou, Qi; Xia, Yong; Yin, Jianping

2018-05-01

A succinct experimental scheme is demonstrated to generate a localized hollow beam by using a π-phase binary bitmap and a convergent thin lens. The experimental results show that the aspect ratio of the dark-spot size of the hollow beam can be effectively controlled by the focal length of the lens. The measured beam profiles in free space also agree with the theoretical modeling. The studies hold great promise that such a hollow beam can be used to cool trapped atoms (or molecules) by Sisyphus cooling and to achieve an optically-trapped Bose–Einstein condensate by optical-potential evaporative cooling.

Numerical methods on flow instabilities in steam generator

International Nuclear Information System (INIS)

Yoshikawa, Ryuji; Hamada, Hirotsugu; Ohshima, Hiroyuki; Yanagisawa, Hideki

2008-06-01

The phenomenon of two-phase flow instability is important for the design and operation of many industrial systems and equipment, such as steam generators. The designer's job is to predict the threshold of flow instability in order to design around it or compensate for it. So it is essential to understand the physical phenomena governing such instability and to develop computational tools to model the dynamics of boiling systems. In Japan Atomic Energy Agency, investigations on heat transfer characteristics of steam generator are being performed for the development of Sodium-cooled Fast Breeder Reactor. As one part of the research work, the evaluations of two-phase flow instability in the steam generator are being carried out experimentally and numerically. In this report, the numerical methods were studied for two-phase flow instability analysis in steam generator. For numerical simulation purpose, the special algorithm to calculate inlet flow rate iteratively with inlet pressure and outlet pressure as boundary conditions for the density-wave instability analysis was established. There was no need to solve property derivatives and large matrices, so the spurious numerical instabilities caused by discontinuous property derivatives at boiling boundaries were avoided. Large time-step was possible. The flow instability in single heat transfer tube was successfully simulated with homogeneous equilibrium model by using the present algorithm. Then the drift-flux model including the effects of subcooled boiling and two phase slip was adopted to improve the accuracy. The computer code was developed after selecting the correlations of drift velocity and distribution parameter. The capability of drift flux model together with the present algorithm for simulating density-wave instability in single tube was confirmed. (author)

"Crosstalk" technique: A comparison between two generations of cryoballoon catheter.

Science.gov (United States)

Yang, Jian-du; Sun, Qi; Guo, Xiao-Gang; Zhou, Gong-Bu; Liu, Xu; Luo, Bin; Wei, Hui-Qiang; Liang, Jackson J; Ma, Jian

2018-03-30

The "Crosstalk" technique: if pulmonary vein isolation (PVI) of the superior one is not achieved due to a gap in the inferior part, it could be done during inferior vein cryoablation. This maneuver minimizes the total energy delivery time and number of lesions. We aimed to correlate the likelihood of crosstalk phenomenon with certain anatomic characteristics. A total of 676 patients undergoing a first ablation procedure for paroxysmal or persistent atrial fibrillation (470 first-generation cryoballoon [CB] and 206 second-generation CB) between June 2014 and December 2016 were included. "Crosstalk" phenomenon occurred in 32 patients (18 first-generation CB, 14 second-generation CB). Compared to 54 control patients without crosstalk, the angle between left superior pulmonary vein (LSPV) and left atrial (LA) roof-plane, left pulmonary common ostia were significant parameters associated with crosstalk (odds ratio [OR] = 1.20, ±95% confidence interval [CI]: 1.11-1.31, P crosstalk technique application to get isolated in LSPV. Among the crosstalk group, there was no statistical difference between first-generation CB and second-generation CB in pulmonary anatomic characteristics. Crosstalk technique can be effective in patients with AF undergoing CB ablation using with both first and second-generation CBs. Anatomic characteristics predictive of crosstalk include a left common ostia and smaller angle between the LSPV and LA roof-plane. © 2018 Wiley Periodicals, Inc.

GENERATION Z AND ITS PERCEPTION OF WORK

OpenAIRE

Maria-Cristina IORGULESCU

2016-01-01

One of the major demograhic phenomenon registered in the present times is represented by the aging of the Romanian population and, consequently, of the workforce, this issue having several implications for the human resource management in organizations. As generation Z prepares to enter the labor market, managers will be facing a set of generational differences between their employees. As a result, the paper presents the characteristics of generation Z, as highlighted by recent studies. Moreo...

Equivalent circuit and characteristic simulation of a brushless electrically excited synchronous wind power generator

Science.gov (United States)

Wang, Hao; Zhang, Fengge; Guan, Tao; Yu, Siyang

2017-09-01

A brushless electrically excited synchronous generator (BEESG) with a hybrid rotor is a novel electrically excited synchronous generator. The BEESG proposed in this paper is composed of a conventional stator with two different sets of windings with different pole numbers, and a hybrid rotor with powerful coupling capacity. The pole number of the rotor is different from those of the stator windings. Thus, an analysis method different from that applied to conventional generators should be applied to the BEESG. In view of this problem, the equivalent circuit and electromagnetic torque expression of the BEESG are derived on the basis of electromagnetic relation of the proposed generator. The generator is simulated and tested experimentally using the established equivalent circuit model. The experimental and simulation data are then analyzed and compared. Results show the validity of the equivalent circuit model.

Generation Y Online Buying Patterns

OpenAIRE

Katija Vojvodić; Matea Matić

2015-01-01

The advantages of electronic retailing can, among other things, result in uncontrolled buying by online consumers, i.e. in extreme buying behavior. The main purpose of this paper is to analyze and determine the buying patterns of Generation Y online consumers in order to explore the existence of different types of behavior based on the characteristics of online buying. The paper also aims at exploring the relationship between extracted factors and Generation Y consumers’ buying intentions. Em...

GENERATION OF IRREGULAR HEXAGONAL MESHES

Directory of Open Access Journals (Sweden)

Vlasov Aleksandr Nikolaevich

2012-07-01

Decomposition is performed in a constructive way and, as option, it involves meshless representation. Further, this mapping method is used to generate the calculation mesh. In this paper, the authors analyze different cases of mapping onto simply connected and bi-connected canonical domains. They represent forward and backward mapping techniques. Their potential application for generation of nonuniform meshes within the framework of the asymptotic homogenization theory is also performed to assess and project effective characteristics of heterogeneous materials (composites.

Challenges and Difficulties to Teaching Engineering to Generation Z: A Case Research

Science.gov (United States)

Correia Barreiro, Suamit; Bozutti, Daniel Fernando

2017-01-01

Many people from generation Z are at the beginning of their academic activities. This generation has peculiar characteristics that might be a challenge in the labor market. Thus, instructors have a great role in their preparation. However, professors might face difficulties dealing with their specific characteristics. The research aims to carry…

Are you ready for generation X?

Science.gov (United States)

Washburn, E R

2000-01-01

Generational analysis considers the differences in world view and attitude between various generations of Americans and uses this information to develop insight and business strategies. The much discussed generation gap between the Baby Boomers and their elders during the 1960s and 1970s is equaled or exceeded by the differences between Generations X and Y and the Boomers. Generation X physicians will be coming into practice over the next two decades. Successful medical leaders must understand Gen-Xers to create clinical environments that meet their unique needs and concerns. This article describes some of the philosophical and attitudinal differences between the generations and what these differences may mean to the future of medicine and health care organizations.

Spectral Growth of Hurricane Generated Seas

National Research Council Canada - National Science Library

Finlayson, William

1997-01-01

The characteristics of a growing sea during hurricanes are significantly different from those observed in ordinary storms since the source of energy generating waves is moving and the rate of change...

USER GENERATED CONTENT IN TOURISM MARKETING

OpenAIRE

ALİKILIÇ, Dr. Özlem

2008-01-01

This article is based on the idea that user generated content is of fundamental importance in tourism and travel industry to understand the role of consumer generated messages. This paper also describes interpersonal influences mean for user generated content and also word of mouth (WOM) which reflect cost effective for tourism and travel industry but as well as the real crisis lead by the customer and discusses the new technological and ethical considerations facing tourism and travel industry

Identifying the hazard characteristics of powder byproducts generated from semiconductor fabrication processes.

Science.gov (United States)

Choi, Kwang-Min; An, Hee-Chul; Kim, Kwan-Sick

2015-01-01

Semiconductor manufacturing processes generate powder particles as byproducts which potentially could affect workers' health. The chemical composition, size, shape, and crystal structure of these powder particles were investigated by scanning electron microscopy equipped with an energy dispersive spectrometer, Fourier transform infrared spectrometry, and X-ray diffractometry. The powders generated in diffusion and chemical mechanical polishing processes were amorphous silica. The particles in the chemical vapor deposition (CVD) and etch processes were TiO(2) and Al(2)O(3), and Al(2)O(3) particles, respectively. As for metallization, WO(3), TiO(2), and Al(2)O(3) particles were generated from equipment used for tungsten and barrier metal (TiN) operations. In photolithography, the size and shape of the powder particles showed 1-10 μm and were of spherical shape. In addition, the powders generated from high-current and medium-current processes for ion implantation included arsenic (As), whereas the high-energy process did not include As. For all samples collected using a personal air sampler during preventive maintenance of process equipment, the mass concentrations of total airborne particles were particles less than 10 μm in diameter) using direct-reading aerosol monitor by area sampling were between 0.00 and 0.02 μg/m(3). Although the exposure concentration of airborne particles during preventive maintenance is extremely low, it is necessary to make continuous improvements to the process and work environment, because the influence of chronic low-level exposure cannot be excluded.

The importance of understanding during the teaching process

Directory of Open Access Journals (Sweden)

Dubljanin Saša

2015-01-01

Full Text Available Learning in the teaching process often goes on without proper understanding which is one of important problems that modern didactics tries to solve. In order to direct the totality of teaching towards understanding it is necessary to answer the question what understanding is, which is why we analysed different philosophical views on the concept of understanding and stressed their semblance to pedagogic explanations. Different kinds of understanding were analyzed as well as their role and contribution in different teaching situations, especially in the context of problem solving. As an alternative to the teaching based on accumulation of knowledge the characteristics and some principles of teaching focused on understanding are described, and the need for stimulating and developing understanding as an important goal of education. The results of our research unequivocally show that learning with understanding enables students to memorize the teaching material better, as well as to understand the whole teaching subject and efficiently apply the acquired knowledge out of school, and leads to more flexible behaviour and better coping in everyday life.

Pseudo-Random Number Generators

Science.gov (United States)

Howell, L. W.; Rheinfurth, M. H.

1984-01-01

Package features comprehensive selection of probabilistic distributions. Monte Carlo simulations resorted to whenever systems studied not amenable to deterministic analyses or when direct experimentation not feasible. Random numbers having certain specified distribution characteristic integral part of simulations. Package consists of collector of "pseudorandom" number generators for use in Monte Carlo simulations.

A Maximum Power Point Tracking Control Method of a Photovoltaic Power Generator with Consideration of Dynamic Characteristics of Solar Cells

Science.gov (United States)

Watanabe, Takashi; Yoshida, Toshiya; Ohniwa, Katsumi

This paper discusses a new control strategy for photovoltaic power generation systems with consideration of dynamic characteristics of the photovoltaic cells. The controller estimates internal currents of an equivalent circuit for the cells. This estimated, or the virtual current and the actual voltage of the cells are fed to a conventional Maximum-Power-Point-Tracking (MPPT) controller. Consequently, this MPPT controller still tracks the optimum point even though it is so designed that the seeking speed of the operating point is extremely high. This system may suit for applications, which are installed in rapidly changeable insolation and temperature-conditions e.g. automobiles, trains, and airplanes. The proposed method is verified by experiment with a combination of this estimating function and the modified Boehringer's MPPT algorithm.

Effect of phosphate ion on filtration characteristics of solids generated in simulated high level liquid waste

International Nuclear Information System (INIS)

Kondo, Y.

1998-01-01

The effect of phosphate ion on the filtration characteristics of solids generated in a high level liquid waste was experimentally examined. Addition of phosphate ion into the simulated HLLW induced the formation of phosphate such as zirconium phosphate and phosphomolybdic acid. The filtration rate of zirconium phosphate abruptly dropped in the midst of filtration because of a gel-cake formation on the filter surface. The denitration of the simulated HLLW contained zirconium phosphate improved the filterability of this gelatinous solid. The filtration rates of denitrated HLLW decreased with increase of the phosphate ion concentration, since the solids formed by denitration had irregular particle size and configuration in the simulated HLLW with phosphate ion. To increase the filtration rate of denitrated HLLW, a solid suspension filtration tester was designed. The solid-suspension accelerated the filtration rate only in the simulated HLLW with more than 1500 ppm phosphate ion concentration. Under this condition, the simple agitation can easily suspend the constituent solids of filter cake in the solution and a much higher filtration rate can be obtained because the filter cake is continuously swept from the filter surface by rotation of propellers. (authors)

Generation of electricity by wind power

Energy Technology Data Exchange (ETDEWEB)

Golding, E W

1976-01-01

Information on wind power is presented concerning the history of windmills; estimation of the energy obtainable from the wind; wind characteristics and distribution; wind power sites; wind surveys; wind flow over hills; measurement of wind velocity; wind structure and its determination; wind data and energy estimation; testing of wind driven ac generators; wind-driven machines; propeller type windmills; plants for isolated premises and small communities; economy of wind power generation; construction costs for large wind-driven generators; relationship of wind power to other power sources; research and development; and international cooperation.

Stability improvement of induction generator-based wind turbine systems

DEFF Research Database (Denmark)

Chen, Zhe; Hu, Y.; Blaabjerg, Frede

2007-01-01

The stability improvement of induction-generator-based wind turbine systems under power system fault conditions has been studied. Two types of generators are considered, namely rotor short-circuited induction generators and dynamic slip-controlled wound rotor induction generators. The factors...... affecting the stability are analysed. The characteristics of the induction-generator-based wind turbines are described, and possible methods of improving stability of the wind generators are discussed. The system modelling is presented, and then the discussed methods of improving stability are investigated...

Understanding Cancer Genome and Its Evolution by Next Generation Sequencing

DEFF Research Database (Denmark)

Hou, Yong

Cancer will cause 13 million deaths by the year of 2030, ranking the second leading cause of death worldwide. Previous studies indicate that most of the cancers originate from cells that acquired somatic mutations and evolved as Darwin Theory. Ten biological insights of cancer have been summarized...... recently. Cutting-age technologies like next generation sequencing (NGS) enable exploring cancer genome and evolution much more efficiently. However, integrated cancer genome sequencing studies showed great inter-/intra-tumoral heterogeneity (ITH) and complex evolution patterns beyond the cancer biological...... knowledge we previously know. There is very limited knowledge of East Asia lung cancer genome except enrichment of EGFR mutations and lack of KRAS mutations. We carried out integrated genomic, transcriptomic and methylomic analysis of 335 primary Chinese lung adenocarcinomas (LUAD) and 35 corresponding...

The use of Functional Resonance Analysis Method (FRAM) in a mid-air collision to understand some characteristics of the air traffic management system resilience

Energy Technology Data Exchange (ETDEWEB)

Rodrigues de Carvalho, Paulo Victor, E-mail: paulov@ien.gov.br [National Nuclear Energy Commission/Nuclear Engineering Institute, Cidade Universitaria-Ilha do Fundao, Rio de Janeiro, RJ 21945-970 (Brazil)

2011-11-15

The Functional Resonance Analysis Model (FRAM) defines a systemic framework to model complex systems for accident analysis purposes. We use FRAM in the mid-air collision between flight GLO1907, a commercial aircraft Boeing 737-800, and flight N600XL, an executive jet EMBRAER E-145, to investigate key resilience characteristics of the Air Traffic Management System (ATM). This ATM system related accident occurred at 16:56 Brazilian time on September 29, 2006 in the Amazonian sky. FRAM analysis of flight monitoring functions showed system constraints (equipment, training, time, and supervision) that produce variability in system behavior, creating demand resources mismatches in an attempt to perceive and control the developing situation. This variability also included control and coordination breakdowns and automation surprises (TCAS functioning). The analysis showed that under normal variability conditions (without catastrophic failures) the ATM system (pilots, controllers, supervisors, and equipment) was not able to close the control loops of the flight monitoring functions using feedback or feedforward strategies to achieve an adequate control of an aircraft flying in the controlled air space. Our findings shed some light on the resilience of Brazilian ATM system operation and indicated that there is a need of a deeper understanding on how the system is actually functioning. - Highlights: > The Functional Resonance Analysis Model (FRAM) was used in a mid-air collision over Amazon. > The aim was to understand key resilience characteristics of the Air Traffic Management System (ATM). > The analysis showed how, under normal conditions, the system was not able to control flight functions. > The findings shed some light about the resilience of Brazilian ATM system operation.

The use of Functional Resonance Analysis Method (FRAM) in a mid-air collision to understand some characteristics of the air traffic management system resilience

International Nuclear Information System (INIS)

Rodrigues de Carvalho, Paulo Victor

2011-01-01

The Functional Resonance Analysis Model (FRAM) defines a systemic framework to model complex systems for accident analysis purposes. We use FRAM in the mid-air collision between flight GLO1907, a commercial aircraft Boeing 737-800, and flight N600XL, an executive jet EMBRAER E-145, to investigate key resilience characteristics of the Air Traffic Management System (ATM). This ATM system related accident occurred at 16:56 Brazilian time on September 29, 2006 in the Amazonian sky. FRAM analysis of flight monitoring functions showed system constraints (equipment, training, time, and supervision) that produce variability in system behavior, creating demand resources mismatches in an attempt to perceive and control the developing situation. This variability also included control and coordination breakdowns and automation surprises (TCAS functioning). The analysis showed that under normal variability conditions (without catastrophic failures) the ATM system (pilots, controllers, supervisors, and equipment) was not able to close the control loops of the flight monitoring functions using feedback or feedforward strategies to achieve an adequate control of an aircraft flying in the controlled air space. Our findings shed some light on the resilience of Brazilian ATM system operation and indicated that there is a need of a deeper understanding on how the system is actually functioning. - Highlights: → The Functional Resonance Analysis Model (FRAM) was used in a mid-air collision over Amazon. → The aim was to understand key resilience characteristics of the Air Traffic Management System (ATM). → The analysis showed how, under normal conditions, the system was not able to control flight functions. → The findings shed some light about the resilience of Brazilian ATM system operation.

Understanding adult neurogenesis beyond its role in learning and memory formation

Directory of Open Access Journals (Sweden)

Ab Latif Wani

2017-04-01

Full Text Available There has been a shift in the understanding of brain, neurons, and their functional role over the last two decades. Earlier it was believed that the brain was a static organ and was not subject to any change throughout life. An understanding was developed later that brain reorganizes its structure by a specific property called neuroplasticity. Recent research shows that the brain generates new neurons even in the adult stage, and this process is called adult neurogenesis. Although researchers still not have all the answers about the newborn neurons, and why and how they are generated, and what is their role, some have highlighted the importance of these in learning and memory formation, and even in memories of fear and spatial navigation. A wide range of environmental experience influences the generation of newborn neurons and their functional variability. There are questions about how different environmental experiences cause the differences in the generation of new neurons. Recently the field of optogenetics attempted to answer the questions on adult neurogenesis. However there are still questions about adult neurogenesis which needs a more naturalistic approach, for their better understanding.

Vibration power generator for a linear MR damper

International Nuclear Information System (INIS)

Sapiński, Bogdan

2010-01-01

The paper describes the structure and the results of numerical calculations and experimental tests of a newly developed vibration power generator for a linear magnetorheological (MR) damper. The generator consists of permanent magnets and coil with foil winding. The device produces electrical energy according to Faraday's law of electromagnetic induction. This energy is applied to vary the damping characteristics of the MR damper attached to the generator by the input current produced by the device. The objective of the numerical calculations was to determine the magnetic field distribution in the generator as well as the electric potential and current density in the generator's coil during the idle run and under the load applied to the MR damper control coil. The results of the calculations were used during the design and manufacturing stages of the device. The objective of the experimental tests carried out on a dynamic testing machine was to evaluate the generator's efficiency and to compare the experimental and predicted data. The experimental results demonstrate that the engineered device enables a change in the kinetic energy of the reciprocal motion of the MR damper which leads to variations in the damping characteristics. That is why the generator may be used to build up MR damper based vibration control systems which require no external power

Influence of the external and internal parameters on the characteristics of generator PV

Science.gov (United States)

Zouli, Mounir; Ghoudelbourk, Sihem; Ouari, Ahmed; Dib, Djallel

2017-02-01

The growing demand for electric power and inevitable future depletion of conventional sources require major research on the alternative sources, like renewable energies. Among which, solar energy is the most largely used because of its many applications. And as Algeria comprises an exceptional solar layer thanks to its large surfaces, therefore it represents an important source of photovoltaic energy. The objective of this work is to be ensured that the energy produced by the photovoltaic plant supplies the electrical distribution network. The configuration of this system comprises a photovoltaic generator, connected to a chopper booster. For an optimal operation of the system, one must connect in cascades partial generators each one connected to a chopper booster adapted by an order MPPT by the method of Disturbance and Observation (P&O) to ensure the operation of their maximum powers whatever the climatic conditions, and also allows to raise the output voltage of these photovoltaic generators. The adaptation between the photovoltaic generator and the load was carried out with the help of converter DC/DC.

Online Community and User-Generated Content: Understanding the Role of Social Networks

Science.gov (United States)

Oh, Jeong Ha

2010-01-01

Models of user generated content (UGC) creation such as Facebook, MySpace, and YouTube are facing robust growth accelerated by the adoption of Web 2.0 technologies and standards. These business models offer a fascinating avenue for exploring the role of social influence online. This dissertation is motivated by the success of YouTube, which is…

Bipolar pulse generator for intense pulsed ion beam accelerator

International Nuclear Information System (INIS)

Ito, H.; Igawa, K.; Kitamura, I.; Masugata, K.

2007-01-01

A new type of pulsed ion beam accelerator named ''bipolar pulse accelerator'' (BPA) has been proposed in order to improve the purity of intense pulsed ion beams. To confirm the principle of the BPA, we developed a bipolar pulse generator for the bipolar pulse experiment, which consists of a Marx generator and a pulse forming line (PFL) with a rail gap switch on its end. In this article, we report the first experimental result of the bipolar pulse and evaluate the electrical characteristics of the bipolar pulse generator. When the bipolar pulse generator was operated at 70% of the full charge condition of the PFL, the bipolar pulse with the first (-138 kV, 72 ns) and the second pulse (+130 kV, 70 ns) was successfully obtained. The evaluation of the electrical characteristics indicates that the developed generator can produce the bipolar pulse with fast rise time and sharp reversing time

Generated dynamics of Markov and quantum processes

CERN Document Server

Janßen, Martin

2016-01-01

This book presents Markov and quantum processes as two sides of a coin called generated stochastic processes. It deals with quantum processes as reversible stochastic processes generated by one-step unitary operators, while Markov processes are irreversible stochastic processes generated by one-step stochastic operators. The characteristic feature of quantum processes are oscillations, interference, lots of stationary states in bounded systems and possible asymptotic stationary scattering states in open systems, while the characteristic feature of Markov processes are relaxations to a single stationary state. Quantum processes apply to systems where all variables, that control reversibility, are taken as relevant variables, while Markov processes emerge when some of those variables cannot be followed and are thus irrelevant for the dynamic description. Their absence renders the dynamic irreversible. A further aim is to demonstrate that almost any subdiscipline of theoretical physics can conceptually be put in...

Modal analysis of a grid-connected direct-drive permanent magnet synchronous generator wind turbine system

DEFF Research Database (Denmark)

Tan, Jin; Wang, Xiao Ru; Chen, Zhe

2013-01-01

In order to study the stability of a grid-connected direct-drive permanent magnet synchronous generator (PMSG) wind turbine systems, this paper presents the modal analysis of a PMSG wind turbine system. A PMSG model suitable for small signal stability analysis is presented. The modal properties...... of a grid-connected PMSG wind turbine system are studied. Then the comprehensive impacts of the shaft model, shaft parameters, operation points and lengths of the transmission line on the modal characteristic of the system are investigated by the eigenvalue analysis method. Meanwhile, the corresponding...... analysis. It offers a better understanding about the essence of the stability of grid-connected PMSG wind turbine system....

Stochastic generation of hourly wind speed time series

International Nuclear Information System (INIS)

Shamshad, A.; Wan Mohd Ali Wan Hussin; Bawadi, M.A.; Mohd Sanusi, S.A.

2006-01-01

In the present study hourly wind speed data of Kuala Terengganu in Peninsular Malaysia are simulated by using transition matrix approach of Markovian process. The wind speed time series is divided into various states based on certain criteria. The next wind speed states are selected based on the previous states. The cumulative probability transition matrix has been formed in which each row ends with 1. Using the uniform random numbers between 0 and 1, a series of future states is generated. These states have been converted to the corresponding wind speed values using another uniform random number generator. The accuracy of the model has been determined by comparing the statistical characteristics such as average, standard deviation, root mean square error, probability density function and autocorrelation function of the generated data to those of the original data. The generated wind speed time series data is capable to preserve the wind speed characteristics of the observed data

Understanding the petrochemical cycle: Part 1

International Nuclear Information System (INIS)

Sedriks, W.

1994-01-01

Fitness in the hydrocarbon processing industry (HPI) arena involves understanding and coping with business cycles: supply and demand. This becomes increasingly more important as the industry globalizes and matures. Competitive-edge thinking needs to look hard at the forces that influence business cycles. Recognition of potential pitfalls is very important when considering: future capacity expansion, mergers and acquisitions, market departure, plant closure, potential product substitution, etc. Understanding pricing mechanisms and the workings of hockey-stick profitability profiles help HPI operators endure cycle downturns and prepare plants to maximize profits for the next upswing. The paper discusses characteristic trends, cycles in the hydrocarbon processing industry, current conditions, and mitigating cycle effects

Dependence of steam generator vibrations on feedwater pressure

International Nuclear Information System (INIS)

Sadilek, J.

1989-01-01

Vibration sensors are attached to the bottom of the steam generator jacket between the input and output primary circuit collectors. The effective vibration value is recorded daily. Several times higher vibrations were observed at irregular intervals; their causes were sought, and the relation between the steam generator vibrations measured at the bottom of its vessel and the feedwater pressure was established. The source of the vibrations was found to be in the feedwater tract of the steam generator. The feedwater tract is described and its hydraulic characteristics are given. Vibrations were measured on the S02 valve. It is concluded that vibrations can be eliminated by reducing the water pressure before the control valves and by replacing the control valves with ones with more suitable control characteristics. (E.J.). 3 figs., 1 tab., 3 refs

Understanding users

DEFF Research Database (Denmark)

Johannsen, Carl Gustav Viggo

2014-01-01

Segmentation of users can help libraries in the process of understanding user similarities and differences. Segmentation can also form the basis for selecting segments of target users and for developing tailored services for specific target segments. Several approaches and techniques have been...... tested in library contexts and the aim of this article is to identify the main approaches and to discuss their perspectives, including their strenghts and weaknesses in, especially, public library contexts. The purpose is also to prsent and discuss the results of a recent - 2014 - Danish library user...... segmentation project using computer-generated clusters. Compared to traditional marketing texts, this article also tries to identify user segments or images or metaphors by the library profession itself....

Fabrication and energy harvesting characteristics of unimorph piezoelectric cantilever generators with interdigitated electrode lead zirconate titanate laminates

Science.gov (United States)

Lee, Min-seon; Yun, Ji-sun; Park, Woon-ik; Hong, Youn-woo; Cho, Jeong-ho; Paik, Jong-hoo; Park, Yong Ho; Son, Chun-myung; Jeong, Young Hun

2017-12-01

Interdigitated electrode (IDE) unimorph piezoelectric cantilever generators (UPCGs) were fabricated and their energy harvesting characteristics were investigated. A hard lead zirconate titanate (PZT) material with a high mechanical quality factor (Q m) of 1280 was used for the active piezoelectric film of the IDE UPCGs. Two different laminated IDE UPCGs were prepared; one has Ag/Pd interdigitated electrode (IDE) formed only on the top and bottom PZT sheets (D-IDE), while the other has Ag/Pd IDE on all of the PZT sheets (M-IDE). Cofiring was conducted at 1050 °C for 2 h for PZT laminates with IDEs. The fabricated IDE UPCGs exhibited power densities of 50.4 µW/cm3 for the D-IDE and 820 µW/cm3 for the M-IDE. The UPCG with the M-IDE exhibited a higher performance than that with the D-IDE. Specifically, a significantly enhanced normalized power factor of 670 µW/(g2·cm3) was found at 118 Hz across 100 kΩ.

Teaching the basics of electricity using a flexible piezoelectric generator

Science.gov (United States)

Seveno, R.; Dufay, T.; El Gibari, M.; Guiffard, B.; Li, H. W.; Morsli, S.; Pichon, A.; Tanguy, E.

2018-07-01

Lecturer-researchers, because of the duality of their profession, can introduce students directly to their research. Stimulating student interest through practical research topics enables students to see the relevance of the teaching/learning process and thereby enhance their motivation. As a major societal issue, research on renewable energies is held in great esteem, particularly among young students with a strong interest in environmental issues. The work presented here relates to the realization of a practical class on the testing of a flexible piezoelectric generator studied as part of the ‘N-air-J’ regional research project. The particular characteristic of piezoelectric materials is that they produce electricity when compressed, which means that they can be used in energy recovery devices. The electrical model associated with this type of generator, consisting of an ideal current source in parallel with a linear capacitor and a load resistor, is sufficiently simple to understand following a course on electricity for first-year university students. High school students in their first year of a science and laboratory technology baccalaureate in France have already taken this practical class as part of a dissemination campaign on scientific culture.

Transient Analysis Needs for Generation IV Reactor Concepts

International Nuclear Information System (INIS)

Siefken, L.J.; Harvego, E.A.; Coryell, E.W.; Davis, C.B.

2002-01-01

The importance of nuclear energy as a vital and strategic resource in the U. S. and world's energy supply mix has led to an initiative, termed Generation IV by the U.S. Department of Energy (DOE), to develop and demonstrate new and improved reactor technologies. These new Generation IV reactor concepts are expected to be substantially improved over the current generation of reactors with respect to economics, safety, proliferation resistance and waste characteristics. Although a number of light water reactor concepts have been proposed as Generation IV candidates, the majority of proposed designs have fundamentally different characteristics than the current generation of commercial LWRs operating in the U.S. and other countries. This paper presents the results of a review of these new reactor technologies and defines the transient analyses required to support the evaluation and future development of the Generation IV concepts. The ultimate objective of this work is to identify and develop new capabilities needed by INEEL to support DOE's Generation IV initiative. In particular, the focus of this study is on needed extensions or enhancements to SCDAP/RELAP5/3D code. This code and the RELAP5-3D code from which it evolved are the primary analysis tools used by the INEEL and others for the analysis of design-basis and beyond-design-basis accidents in current generation light water reactors. (authors)

Understanding Dynamic Model Validation of a Wind Turbine Generator and a Wind Power Plant: Preprint

Energy Technology Data Exchange (ETDEWEB)

Muljadi, Eduard; Zhang, Ying Chen; Gevorgian, Vahan; Kosterev, Dmitry

2016-09-01

Regional reliability organizations require power plants to validate the dynamic models that represent them to ensure that power systems studies are performed to the best representation of the components installed. In the process of validating a wind power plant (WPP), one must be cognizant of the parameter settings of the wind turbine generators (WTGs) and the operational settings of the WPP. Validating the dynamic model of a WPP is required to be performed periodically. This is because the control parameters of the WTGs and the other supporting components within a WPP may be modified to comply with new grid codes or upgrades to the WTG controller with new capabilities developed by the turbine manufacturers or requested by the plant owners or operators. The diversity within a WPP affects the way we represent it in a model. Diversity within a WPP may be found in the way the WTGs are controlled, the wind resource, the layout of the WPP (electrical diversity), and the type of WTGs used. Each group of WTGs constitutes a significant portion of the output power of the WPP, and their unique and salient behaviors should be represented individually. The objective of this paper is to illustrate the process of dynamic model validations of WTGs and WPPs, the available data recorded that must be screened before it is used for the dynamic validations, and the assumptions made in the dynamic models of the WTG and WPP that must be understood. Without understanding the correct process, the validations may lead to the wrong representations of the WTG and WPP modeled.

Analysis of the pump-turbine S characteristics using the detached eddy simulation method

Science.gov (United States)

Sun, Hui; Xiao, Ruofu; Wang, Fujun; Xiao, Yexiang; Liu, Weichao

2015-01-01

Current research on pump-turbine units is focused on the unstable operation at off-design conditions, with the characteristic curves in generating mode being S-shaped. Unlike in the traditional water turbines, pump-turbine operation along the S-shaped curve can lead to difficulties during load rejection with unusual increases in the water pressure, which leads to machine vibrations. This paper describes both model tests and numerical simulations. A reduced scale model of a low specific speed pump-turbine was used for the performance tests, with comparisons to computational fluid dynamics(CFD) results. Predictions using the detached eddy simulation(DES) turbulence model, which is a combined Reynolds averaged Naviers-Stokes(RANS) and large eddy simulation(LES) model, are compared with the two-equation turbulence mode results. The external characteristics as well as the internal flow are for various guide vane openings to understand the unsteady flow along the so called S characteristics of a pump-turbine. Comparison of the experimental data with the CFD results for various conditions and times shows that DES model gives better agreement with experimental data than the two-equation turbulence model. For low flow conditions, the centrifugal forces and the large incident angle create large vortices between the guide vanes and the runner inlet in the runner passage, which is the main factor leading to the S-shaped characteristics. The turbulence model used here gives more accurate simulations of the internal flow characteristics of the pump-turbine and a more detailed force analysis which shows the mechanisms controlling of the S characteristics.

Socio-Demographic Characteristics Of Dog Meat Consumers In ...

African Journals Online (AJOL)

The need to understand consumer spread prompted this study, which had the general objective of understanding the socio-demographic characteristics of dog meat consumers Calabar area of Cross River State, Nigeria. Thirty two (32) dog meat joints, 16 in Calabar Municipality, and 16 in Calabar South Local Government ...

Steam generators for nuclear power plants

International Nuclear Information System (INIS)

Tillequin, Jean

1975-01-01

The role and the general characteristics of steam generators in nuclear power plants are indicated, and particular types are described according to the coolant nature (carbon dioxide, helium, light water, heavy water, sodium) [fr

Characteristics of carrier-generated field-effect transistors with pentacene/vanadium pentoxide

International Nuclear Information System (INIS)

Minagawa, M.; Nakai, K.; Baba, A.; Shinbo, K.; Kato, K.; Kaneko, F.; Lee, C.

2011-01-01

In this paper, the driving mechanism of carrier-generated organic field-effect transistors (OFETs) with pentacene and vanadium pentoxide (V 2 O 5 ) layers is discussed. In this study, large on-currents were observed in an OFET with a 35-nm V 2 O 5 layer. Devices with aluminum (Al)/pentacene/V 2 O 5 /Al layer structures were also prepared. These devices exhibited a large current density in spite of their high carrier injection barriers between each layer and the Al electrodes. Moreover, new absorption bands corresponding to the radical cation absorption of pentacene were observed within the absorption spectrum of the pentacene and V 2 O 5 mixed layers. It was inferred that the charge transfer (CT) complexes that formed at the interface between the pentacene and V 2 O 5 layers were dissociated by the applied gate voltage and that the generated holes contributed to driving the OFETs.

Development and basic photovoltaic characteristics of a solar generator with double-sided silicon cells

International Nuclear Information System (INIS)

Aliev, R.; Mansurov, Kh.

2015-01-01

A new solar generator consisting of double-sided silicon sensing elements is described. The basic photovoltaic parameters of solar generators are made of mono- and polycrystalline silicon solar cells. (author)

Dynamical generation of flavour

Indian Academy of Sciences (India)

Introduction of family symmetry and generation of flavour structure by Yukawa couplings arising as vacuum expectation values (VEVs) of 'spurion' fields offers an attractive alternative prospect for understanding flavour structure [1]. Model builders have considered various. Pramana – J. Phys., Vol. 86, No. 2, February 2016.

Understanding Application Behaviours for Android Security: A Systematic Characterization

OpenAIRE

Cai, Haipeng; Ryder, Barbara

2016-01-01

In contrast to most existing research on Android focusing on specific security issues, there is little broad understanding of Android application run-time characteristics and their security implications. To mitigate this gap, we present the first dynamic characterization study of Android applications that targets such a broad understanding for Android security. Through lightweight method-level profiling, we have collected 33GB traces of method calls and inter-component communication (ICC) fro...

Characteristics of the General Physics student population.

Science.gov (United States)

Hunt, Gary L.

2006-12-01

Are pre-medical students different than the other students in a General physics class? They often appear to be different, based on how often they seek help from the instructor or how nervous they are about 2 points on a lab report. But are these students different in a measurable characteristic? The purpose of this study is to better understand the characteristics of the students in the introductory physics classes. This is the first step toward improving the instruction. By better understanding the students the classroom, the organization and pedagogy can be adjusted to optimize student learning. The characteristics to be investigated during this study are: · student epistemological structure, · student attitudes, · science course preparation prior to this course, · study techniques used, · physics concepts gained during the class · performance in the class. The data will be analyzed to investigate differences between groups. The groups investigated will be major, gender, and traditional/nontraditional students.

Syntegra - the next generation of powered bogies; Syntegra - Innovativer Prototyp einer naechsten Triebfahrwerk-Generation

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, T.; Teichmann, M. [Siemens AG, Graz (Austria); Joeckel, A. [Siemens AG, Graz (Austria); Loewenstein, L.; Wangelin, F. von [Siemens AG, Erlangen (Germany)

2007-07-01

The innovative Syntegra {sup registered} concept fundamentally revolutionizes the characteristics of today's powered bogies and represents a new and highly integrative approach in bogie design. Syntegra combines the traction, bogie and braking technology to form a unified mechatronic system. This approach and, above all, the change of technology generate a large number of synergetic benefits. This new generation of powered bogies unites high efficiency and low weight with reduced lifecycle costs (LCC) and offers considerably better performance than conventional bogie solutions. A first prototype is in service. (orig.)

Cost-based droop scheme with lower generation costs for microgrids

DEFF Research Database (Denmark)

Nutkani, I. U.; Loh, Poh Chiang; Blaabjerg, Frede

2013-01-01

on the DG kVA ratings. Other operating characteristics like generation costs, efficiencies and emission penalties at different loadings have not been considered. This makes existing droop schemes not too well-suited for standalone microgrids without central management system, where different types of DGs...... usually exist. As an alternative, this paper proposes a cost-based droop scheme, whose objective is to reduce a generation cost realized with various DG operating characteristics taken into consideration. The proposed droop scheme therefore retains all advantages of the traditional droop schemes, while...... at the same time keep its generation cost low. These findings have been validated through simulation and scaled down lab experiment....

Recruiting the Next Generation: A Study of Attitudes, Values, and Beliefs

National Research Council Canada - National Science Library

Wilcox, Andrew

2001-01-01

.... Specifically, the study looks at generational theory, the characteristics and views of the so-called 'Millennial' generation, factors that influence attitudes toward military service, and recruiting...

Retention in the allied health workforce: boomers, generation X, and generation Y.

Science.gov (United States)

Dodd, Jenny; Saggers, Sherry; Wildy, Helen

2009-01-01

The recruitment and retention of allied health workers present challenges for organizations in Australia and internationally. Australia, in common with other developed countries, faces the prospect of a rapidly aging population and the high turnover of younger allied health workers (the majority of whom are female) from employing organizations. Emphases on the individual characteristics of Boomer, Generation X, and Generation Y workers may provide a useful starting base for recruitment and retention strategies, but our study shows that these need to be contextualized within broader political, social, and structural factors that take account of gender and the changing needs of workers over their life span.

A wind tunnel investigation of the effects of micro-vortex generators and Gurney flaps on the high-lift characteristics of a business jet wing. M.S. Thesis

Science.gov (United States)

Martuccio, Michelle Therese

1994-01-01

A study of a full-scale, semi-span business jet wing has been conducted to investigate the potential of two types of high-lift devices for improving aircraft high-lift performance. The research effort involved low-speed wind-tunnel tests of micro-vortex generators and Gurney flaps applied to the flap system of the business jet wing and included force and moment measurements, surface pressure surveys and flow visualization on the wing and flap. Results showed that the micro-vortex generators tested had no beneficial effects on the longitudinal force characteristics in this particular application, while the Gurney flaps were an effective means of increasing lift. However, the Gurney flaps also caused an increase in drag in most circumstances.

Understanding the Entrepreneurial Process: a Dynamic Approach

Directory of Open Access Journals (Sweden)

Vânia Maria Jorge Nassif

2010-04-01

Full Text Available There is considerable predominance in the adoption of perspectives based on characteristics in research into entrepreneurship. However, most studies describe the entrepreneur from a static or snapshot approach; very few adopt a dynamic perspective. The aim of this study is to contribute to the enhancement of knowledge concerning entrepreneurial process dynamics through an understanding of the values, characteristics and actions of the entrepreneur over time. By focusing on personal attributes, we have developed a framework that shows the importance of affective and cognitive aspects of entrepreneurs and the way that they evolve during the development of their business.

Market protocols in ERCOT and their effect on wind generation

International Nuclear Information System (INIS)

Sioshansi, Ramteen; Hurlbut, David

2010-01-01

Integrating wind generation into power systems and wholesale electricity markets presents unique challenges due to the characteristics of wind power, including its limited dispatchability, variability in generation, difficulty in forecasting resource availability, and the geographic location of wind resources. Texas has had to deal with many of these issues beginning in 2002 when it restructured its electricity industry and introduced aggressive renewable portfolio standards that helped spur major investments in wind generation. In this paper we discuss the issues that have arisen in designing market protocols that take account of these special characteristics of wind generation and survey the regulatory and market rules that have been developed in Texas. We discuss the perverse incentives some of the rules gave wind generators to overschedule generation in order to receive balancing energy payments, and steps that have been taken to mitigate those incentive effects. Finally, we discuss more recent steps taken by the market operator and regulators to ensure transmission capacity is available for new wind generators that are expected to come online in the future.

Assessment of wind characteristics for energy generation

Energy Technology Data Exchange (ETDEWEB)

Koray Ulgen [Ege University, Izmir (Turkey). Solar Energy Institute; Asir Genc [Selcuk University, Konya (Turkey). Dept. of Statistics; Arif Hepbasli [Ege University, Izmir (Turkey). Dept. of Mechanical Engineering; Galip Oturanc [Selcuk University, Konya (Turkey). Dept. of Mathematics

2004-11-15

Wind technology in Turkey has gained considerable maturity over the last five years, and wind energy projects are becoming commercially attractive in the country. In practice, it is essential to describe the variation of wind speeds for optimizing the design of the systems resulting in less energy generating costs. The wind variation for a typical site is usually described using the so-called Weibull distribution. In this study, the two Weibull parameters of the wind speed distribution function, the shape parameter k (dimensionless) and the scale parameter c (m/s), were computed from the wind speed data for Aksehir in Konya, located in Central Anatolia in Turkey (latitude: 38.35{sup o} and longitude: 31.42{sup o}). Wind data, consisting of hourly wind speed records over a 6 year period, 1997-2002, were obtained from the Aksehir State Meteorological Station. Based on the experimental data, it was found that the numerical values of both Weibull parameters (k and c) for Aksehir vary over a wide range. The yearly values of k range from 1.756 to 2.076, while those of c are in the range of 2.956 to 3.444. Average seasonal Weibull distributions for Aksehir are given. The wind speed distributions are represented by Weibull distribution and also by Rayleigh distribution with a special case of the Weibull distribution for k = 2. The Rayleigh distribution is found to be suitable to represent the actual probability of wind speed data for the site studied. (author)

Learning science in small groups: The relationship of conversation to conceptual understanding

Science.gov (United States)

McDonald, James Tarleton

The purpose of this study was to investigate the relationship between conversation and conceptual understanding of erosion. The objective of this study was to investigate how fifth grade students' conceptions of erosion changed while they used stream tables and worked in groups of four within an inquiry-based curriculum. This study used symbolic interactionism and sociocognitive frameworks to interpret science learning in the elementary classroom. The research focused on the conceptual understanding of the focal group students, their use of classroom discourse to talk about their understandings of erosion, and the expertise that emerged while using stream tables. This study took place over a one-semester long study on erosion. Key informants were eight fifth graders. The data sources consisted of children's journals; transcripts of audiotaped interviews with the key informants before, during, and after the erosion unit; transcripts of videotapes of the students using the stream tables; and field notes recording children's discourse and activity. Individual and group cases were constructed during the study. The knowledge of the eight focal group children was placed on a hierarchy of conceptual understanding that contained 8 components of the erosion process. All four of the students whose ideas were examined in depth gained in their conceptual understanding of erosion. Students' individual expertise enhanced their own conceptual understanding. The contribution of classroom discourse and expertise to conceptual understanding differed between the two focal groups. Group 1 used essential expertise to sustain generative conversations, maximizing their learning opportunities. Students in Group 1 got along with one another, rotated assigned roles and jobs, and were able to start their own generative conversations. Members of Group 1 asked generative questions, connected stream table events to real life situations, and involved everyone in the group. Group 2 engaged in a

Higher-Order Moment Characterisation of Rogue Wave Statistics in Supercontinuum Generation

DEFF Research Database (Denmark)

Sørensen, Simon Toft; Bang, Ole; Wetzel, Benjamin

2012-01-01

The noise characteristics of supercontinuum generation are characterized using higherorder statistical moments. Measures of skew and kurtosis, and the coefficient of variation allow quantitative identification of spectral regions dominated by rogue wave like behaviour.......The noise characteristics of supercontinuum generation are characterized using higherorder statistical moments. Measures of skew and kurtosis, and the coefficient of variation allow quantitative identification of spectral regions dominated by rogue wave like behaviour....

A third generation mobile high energy radiography system

International Nuclear Information System (INIS)

Fry, D.A.; Valdez, J.E.; Johnson, C.S.; Kimerly, H.J.; Vananne, J.R.

1997-01-01

A third generation mobile high energy radiographic capability has been completed and put into service by the Los Alamos National Laboratory. The system includes a 6 MeV linac x-ray generator, Co-60 gamma source, all-terrain transportation, on-board power, real-time radiography (RTR), a control center, and a complete darkroom capability. The latest version includes upgraded and enhanced portability, flexibility, all-terrain operation, all-weather operation, and ease of use features learned from experience with the first and second generation systems. All systems were required to have the following characteristics; all-terrain, all-weather operation, self-powered, USAF airlift compatible, reliable, simple to setup, easy to operate, and all components two-person portable. The systems have met these characteristics to differing degrees, as is discussed in the following section, with the latest system being the most capable

Neutron radiation characteristics of the IVth generation reactor spent fuel

Science.gov (United States)

Bedenko, Sergey; Shamanin, Igor; Grachev, Victor; Knyshev, Vladimir; Ukrainets, Olesya; Zorkin, Andrey

2018-03-01

Exploitation of nuclear power plants as well as construction of new generation reactors lead to great accumulation of spent fuel in interim storage facilities at nuclear power plants, and in spent fuel «wet» and «dry» long-term storages. Consequently, handling the fuel needs more attention. The paper is focused on the creation of an efficient computational model used for developing the procedures and regulations of spent nuclear fuel handling in nuclear fuel cycle of the new generation reactor. A Thorium High-temperature Gas-Cooled Reactor Unit (HGTRU, Russia) was used as an object for numerical research. Fuel isotopic composition of HGTRU was calculated using the verified code of the MCU-5 program. The analysis of alpha emitters and neutron radiation sources was made. The neutron yield resulting from (α,n)-reactions and at spontaneous fission was calculated. In this work it has been shown that contribution of (α,n)-neutrons is insignificant in case of such (Th,Pu)-fuel composition and HGTRU operation mode, and integral neutron yield can be approximated by the Watt spectral function. Spectral and standardized neutron distributions were achieved by approximation of the list of high-precision nuclear data. The distribution functions were prepared in group and continuous form for further use in calculations according to MNCP, MCU, and SCALE.

Operational characteristics of the high flux plasma generator Magnum-PSI

Energy Technology Data Exchange (ETDEWEB)

Eck, H.J.N. van, E-mail: h.j.n.vaneck@differ.nl [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Abrams, T. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Berg, M.A. van den; Brons, S.; Eden, G.G. van [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Jaworski, M.A.; Kaita, R. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Meiden, H.J. van der; Morgan, T.W.; Pol, M.J. van de; Scholten, J.; Smeets, P.H.M.; De Temmerman, G.; Vries, P.C. de; Zeijlmans van Emmichoven, P.A. [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands)

2014-10-15

Highlights: •We have described the design and capabilities of the plasma experiment Magnum-PSI. •The plasma conditions are well suited for PSI studies in support of ITER. •Quasi steady state heat fluxes over 10 MW m{sup −2} have been achieved. •Transient heat and particle loads can be generated to simulate ELM instabilities. •Lithium coating can be applied to the surfaces of samples under vacuum. -- Abstract: In Magnum-PSI (MAgnetized plasma Generator and NUMerical modeling for Plasma Surface Interactions), the high density, low temperature plasma of a wall stabilized dc cascaded arc is confined to a magnetized plasma beam by a quasi-steady state axial magnetic field up to 1.3 T. It aims at conditions that enable fundamental studies of plasma–surface interactions in the regime relevant for fusion reactors such as ITER: 10{sup 23}–10{sup 25} m{sup −2} s{sup −1} hydrogen plasma flux densities at 1–5 eV. To study the effects of transient heat loads on a plasma-facing surface, a high power pulsed magnetized arc discharge has been developed. Additionally, the target surface can be transiently heated with a pulsed laser system during plasma exposure. In this contribution, the current status, capabilities and performance of Magnum-PSI are presented.

Internal cavity characteristics of northern long-eared bat (Myotis septentrionalis) maternity day-roosts

Science.gov (United States)

Alexander Silvis; R. Edward Thomas; W. Mark Ford; Eric R. Britzke; Meryl J. Friedrich

2015-01-01

This report discusses characteristics of seven tree cavities used as day-roosts by female northern long-eared bats (Myotis septentrionalis) during the maternity season in a deciduous forest in north-central Kentucky. Understanding the characteristics of cavities selected by bats will help us better understand the ecology of cavity roosting bats and...

Modeling of Activated Sludge Floc Characteristics

OpenAIRE

Ibrahim H. Mustafa; G. Ibrahim; Ali Elkamel; A. H. Elahwany

2009-01-01