WorldWideScience

Sample records for stand-alone freshman academy

  1. Stand-alone XLIF

    DEFF Research Database (Denmark)

    Hansen, E. J.; Simony, A.; Hummel, Stefan

    2015-01-01

    and clinical/radiological results in 22 patients treated with XLIF procedure for DS or degenerative disc disease (DDD). Material and methods: 22 consecutive patients with DS underwent surgery with the XLIF stand-alone procedure, with follow-up of 24 months. Clinical outcome scores were collected. Complications......Introduction: Adult thoracolumbar degeneration is an increasing challenge in the aging population. With age the progressive degeneration of the discs leads to an asymmetric collapse and a thoracolumbar coronal plane deformity, a degenerative scoliosis (DS). Aim: To evaluate the complication rate......-year follow-up, with a 31.8% revision rate. Due to the high revision rate we recommend supplementary posterior instrumentation, to achieve a higher fusion rate. When considering XLIF-stand-alone procedure for DS or DDD without supplemental posterior instrumentation, only single-level disease should...

  2. Impact of a Freshman Academy on Student Performance at a Comprehensive Public High School

    Science.gov (United States)

    Hernandez, Jose Angel, Jr.

    2012-01-01

    Previous high school research has highlighted the importance of students' freshman year. Limited research has supported the implementation of a smaller learning community, also known as a freshman academy. The theoretical framework of the study was based on stage environment fit, adolescence development and smaller learning community theories. The…

  3. The Stand-alone Heliostat

    International Nuclear Information System (INIS)

    Garcia Navajas, G. I.; Egea Gea, A.

    2000-01-01

    The first Autonomous Heliostat has been developed by CIEMAT at PSA facilities in Almeria. This heliostat is an innovative approach to reducing the civil engineering work costs in heliostat fields of central tower plants. Channels, cables and other electric elements have been eliminated in the new heliostat. Thus, one 70-nr, classical T glass/metal heliostat has been adapted to include all the new stand-alone concept components. A PV system is able to drive two sun-tracking DC motors between 5 and 24Vdc, 0 and 15A. The heliostat communicates with the control room 400-m away by using a radio-modem working at 9600 baud. An anemometer, a wind switcher, light and ambient temperature sensors have been installed on the heliostat for self-protection decision-making. A PV panel integrated into the heliostat reflecting surface, eliminates cabling and other elements required for a conventional power supply. Communication lines between master control and local control have been replaced by radio-modem. Testing has validated the technical feasibility of the prototype and quantified the real consumption and efficiencies of new elements. The extra costs produced.by the autonomous concepts are compared with the cost of civil work in conventional heliostat field. (Author) 8 refs

  4. Basic Stand Alone Medicare Outpatient Procedures PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Outpatient Procedures Public Use Files (PUF) with information from Medicare outpatient claims. The CMS BSA...

  5. Basic Stand Alone Medicare Hospice Beneficiary PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Hospice Beneficiary Public Use Files (PUF) with information from Medicare hospice claims. The CMS BSA Hospice...

  6. Basic Stand Alone Carrier Line Items PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Carrier Line Items Public Use Files (PUF) with information from Medicare Carrier claims. The CMS BSA Carrier Line...

  7. Basic Stand Alone Medicare Inpatient Claims PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Inpatient Public Use Files (PUF) named CMS 2008 BSA Inpatient Claims PUF with information from 2008 Medicare...

  8. A Freshman Academy's Influence on Student Connectivity, Attendance, and Academic Achievement

    Science.gov (United States)

    LoPresti, Nancy O.

    2017-01-01

    The transition from 8th to 9th grade, from middle school to high school, is considered one of the most challenging experiences in an adolescent's life. Ninth-grade transition programs, often referred to as freshman academies, have been developed and implemented over the last decade to address the needs of 9th grade students. The purpose of this…

  9. Stand-alone photovoltaic applications. Lessons learned

    International Nuclear Information System (INIS)

    Loois, G.; Van Hemert, B.

    1999-02-01

    The IEA Photovoltaic Power Systems Programme (PVPS) is one of the collaborative R and D agreements established within the IEA. The objective of Task III is to promote and facilitate the exchange of information and experiences in the field of PV Systems in Stand-alone and Island Applications (SAPV). The book focuses on the practical experiences gained, and does not aim to provide a complete manual on SAPV. When Task III started its activities in 1993, a collection of 50 'State of the art' projects was published in the book 'Examples of Stand-Alone Photovoltaic Systems'. This publication marked the base line for the work of the task. Now, in 1998, the showcases from each country demonstrate the lessons learned in five years of cooperation. The book consists of two parts. The first part contains eight chapters dealing with a specific aspect of stand-alone PV. The second part introduces 14 national showcase projects in a systematic presentation. Each chapter and showcase can be read independently from the rest of the book. Chapter 2, contributed by The Netherlands, analyses the market for stand-alone PV systems. It gives an overview of the 'traditional' application of stand-alone PV, which is the electrification of remote buildings and which has been addressed in depth in other publications. The focus is on the market niches of service applications that are also interesting for more densely populated areas, e.g. in industrialised countries. The United Kingdom illustrates the economic aspects in Chapter 3. Cost comparisons are made, but more important is the illustration of the non-financial considerations that make PV the preferred choice as a power source for many applications. Switzerland explores in Chapter 4 (financing aspects) different financing mechanisms, and financial policies used to overcome the initial cost barrier. Most of these approaches have been applied in developing countries rather than in the western world. Using various examples from all over the

  10. 39 CFR 122.2 - Stand-alone special services.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Stand-alone special services. 122.2 Section 122.2 Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES [DOMESTIC MAIL] SERVICE STANDARDS FOR MARKET-DOMINANT SPECIAL SERVICES PRODUCTS § 122.2 Stand-alone special services. (a) The service standard...

  11. Ampere hour method of sizing a stand alone photovoltaic system ...

    African Journals Online (AJOL)

    Stand-alone photovoltaic power systems are natural options for application in electrification of remote areas which are not served by the grid electricity supply system. An ampere-hour method of sizing a stand-alone PV system for application in any remote location has been presented. The design which is for both ac and dc ...

  12. Basic Stand Alone Skilled Nursing Facility Beneficiary PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Skilled Nursing Facility (SNF) Beneficiary Public Use Files (PUF) with information from Medicare SNF claims. The...

  13. Basic Stand Alone Medicare Home Health Beneficiary PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Home Health Agency (HHA) Beneficiary Public Use Files (PUF) with information from Medicare HHA claims. The CMS BSA...

  14. Basic Stand Alone Medicare DME Line Items PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Durable Medical Equipment (DME) Line Items Public Use Files (PUF) with information from Medicare DME claims. The...

  15. Models for a stand-alone PV system

    DEFF Research Database (Denmark)

    Hansen, A.D.; Sørensen, Poul Ejnar; Hansen, L.H.

    2001-01-01

    This report presents a number of models for modelling and simulation of a stand-alone photovoltaic (PV) system with a battery bank verified against a system installed at Risø National Laboratory. The work has been supported by the Danish Ministry ofEnergy, as a part of the activities in the Solar...... Energy Centre Denmark. The study is carried out at Risø National Laboratory with the main purpose to establish a library of simple mathematical models for each individual element of a stand-alone PVsystem, namely solar cells, battery, controller, inverter and load. The models for PV module and battery...

  16. The Freshman Grade Academy: A Program to Facilitate the Smooth Transition of Students from the Junior High Learning Environment to the High School Learning Environment

    Directory of Open Access Journals (Sweden)

    Michelle Weathers

    2006-03-01

    Full Text Available From 2004-2006, Arkansas High School in Texarkana, Arkansas, piloted a program aimed at facilitating the transition of freshman students from a junior high setting to a senior high setting. The creation of the program was prompted by the school’s data showing that the freshman class had the highest number of disciplinary referrals, absenteeism, and failing grades, while simultaneously having extremely low benchmark test scores. The program, named the Freshman Academy, consisted of three teams with five core team teachers in the areas of English, computer business applications, math and social studies along with an inclusion special education teacher. The teams were given a common planning time to work together to foster student success in both academic and social circles. After two years of piloting the Freshman Academy, the data showed that the number of discipline referrals decreased, absenteeism was down, grades were up and benchmark test scores were up.

  17. PMBLDCG based stand-alone wind energy conversion system for ...

    African Journals Online (AJOL)

    This paper deals with a permanent magnet brushless DC generator (PMBLDCG) based stand-alone wind energy conversion system (WECS) for small scale power generation. A buck-boost DC-DC converter is used for controlling the PMBLDCG speed to achieve optimum energy output from the wind turbine without sensing ...

  18. The stand-alone test and decreasing serial cost sharing

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Thorlund-Petersen, Lars

    2000-01-01

    The rule of decreasing serial cost sharing defined in de Frutos [1] over the class of concave cost functions may violate the important stand-alone test. Sufficient conditions for the test to be satisfied are given, in terms of individual rationality as well as coalitional stability...

  19. Radon Monitoring in Army Stand-Alone Housing Units

    Science.gov (United States)

    1990-04-01

    Y cm a cc 0000 0003 000 000 :: - -@-I.00 cmjinu mooc . 0J~CJ~ TTTT J !8 2 T WWWW WW.000 coo 0~~ 80 Im - v ;o e I3 ec ;: C -1,4 04. -c mco : - a c W" 1 .1...Chamber ....................... 25 V U I I I viI Final Report, April 1990 Radon Monitoring in Army Stand-alone Housing Units Summary Argonne National...and analysis. The quality control protocols appli- cable to detector analysis are contained in Chapter V of the procedures manual developed by Tech

  20. Future UK markets for stand-alone renewable energy systems

    International Nuclear Information System (INIS)

    Paish, O.

    1999-01-01

    A study to identify and quantify the market for stand-alone renewable energy supplies of power (photovoltaics, wind and micro-hydro electricity systems) was described. The study focused on small systems, generally less than a few kW installed capacity. It was suggested that in the UK, the emphasis on grid-connected renewable energy technologies (RETs) has blurred the fact that it is 'off-grid' renewable systems that can offer more immediate real commercial markets for the renewables business. With the likelihood of a significant increase in demand for renewables world wide over the next ten years, the UK needs to make a special effort to become involved

  1. 49 CFR 1111.8 - Procedural schedule in stand-alone cost cases.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Procedural schedule in stand-alone cost cases... § 1111.8 Procedural schedule in stand-alone cost cases. (a) Procedural schedule. Absent a specific order by the Board, the following general procedural schedule will apply in stand-alone cost cases: Day 0...

  2. Hydrogen Gas Production in a Stand-Alone Wind Farm

    Directory of Open Access Journals (Sweden)

    M. Naziry Kordkandy

    2017-04-01

    Full Text Available This paper is analyzing the operation of a stand-alone wind farm with variable speed turbines, permanent magnet synchronous generators (PMSG and a system for converting wind energy during wind speed variations. On this paper, the design and modeling of a wind system which uses PMSG’s to provide the required power of a hydrogen gas electrolyzer system, is discussed. This wind farm consists of three wind turbines, boost DC-DC converters, diode full bridge rectifiers, permanent magnet synchronous generators, MPPT control and a hydrogen gas electrolyzer system. The MPPT controller based on fuzzy logic is designed to adjust the duty ratio of the boost DC-DC converters to absorb maximum power. The proposed fuzzy logic controller assimilates, with (PSF MPPT algorithm which generally used to absorb maximum power from paralleled wind turbines and stores it in form of hydrogen gas. The system is modeled and its behavior is studied using the MATLAB software.

  3. DOE and AID stand-alone photovoltaic activities

    Science.gov (United States)

    Bifano, W. J.; Ratajczak, A. F.

    The NASA Lewis Research Center (LeRC) is managing stand-alone photovoltaic (PV) system activities sponsored by the U.S. Department of Energy (DOE) and the U.S. Agency for International Development (AID). The DOE project includes village PV power demonstration projects in Gabon (four sites) and the Marshall Islands, PV-powered medical refrigerators in six countries, PV system microprocessor control development activities and PV-hybrid system assessments. The AID project includes a large village system in Tunisia, a water pumping/grain grinding project in Upper Volta, five medical clinics in four countries, PV-powered remote earth station application. These PV activities and summarizes significant findings to data are reviewed.

  4. Integral type small PWR with stand-alone safety

    International Nuclear Information System (INIS)

    Makihara, Yoshiaki

    2001-01-01

    A feasibility study is achieved on an integral type small PWR with stand-alone safety. It is designed to have the following features. (1) The coolant does not leak out at any accidental condition. (2) The fuel failure does never occur while it is supposed on the large scale PWR at the design base accident. (3) At any accidental condition the safety is secured without any support from the outside (stand-alone safety secure). (4) It has self-regulating characteristics and easy controllability. The above features can be satisfied by integrate the steam generator and CRDM in the reactor vessel while the pipe line break has to be considered on the conventional PWR. Several counter measures are planned to satisfy the above features. The economy feature is also attained by several simplifications such as (1) elimination of main coolant piping and pressurizer by the integration of primary cooling system and self-pressurizing, (2) elimination of RCP by application of natural circulating system, (3) elimination of ECCS and accumulator by application of static safety system, (4) large scale volume reduction of the container vessel by application of integrated primary cooling system, (5) elimination of boric acid treatment by deletion of chemical shim. The long operation period such as 10 years can be attained by the application of Gd fuel in one batch refueling. The construction period can be shortened by the standardizing the design and the introduction of modular component system. Furthermore the applicability of the reduced modulation core is also considered. (K. Tsuchihashi)

  5. The Stand-alone Heliostat; El Heliostato Autonomo

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Navajas, G.; Egea Gea, A. [Ciemat. Madrid (Spain)

    2000-07-01

    The first Autonomous Heliostat has been developed by CIEMAT at PSA facilities in Almeria. This heliostat is an innovative approach to reducing the civil engineering work costs in heliostat fields of central tower plants. Channels, cables and other electric elements have been eliminated in the new heliostat. Thus, one 70-m''2, classical T glass/metal heliostat has been adapted to include all the new stand-alone concept components. A PV system is able to drive two sun-tracking DC motors between 5 and 24 Vdc, 0 and 15A. The heliostat communicates with the control room 400-m away by using a radio-modern working at 9600 baud. An anemometer, a wind switcher, light and ambient temperature sensors have been installed on the heliostat for self-protection decision-making. A PV panel integrated into the heliostat reflecting surface, eliminates cabling and other elements required for a conventional power supply. Communication lines between master control and local control have been replaced by radio-modern. Testing has validated the technical feasibility of the prototype and quantified the real consumption and efficiencies of new elements. The extra costs produced by the autonomous concepts are compared with the cost of civil work in conventional heliostat field. (Author) 8 refs.

  6. Improving efficiency of a regional stand alone bone bank.

    Science.gov (United States)

    Warnock, Jonathan M; Rowan, Clare H; Davidson, Helen; Millar, Ciara; McAlinden, M Gavan

    2016-03-01

    The introduction of a stand-alone Bone Bank in our Regional Orthopaedic Hospital has improved the availability of femoral head allograft. Benninger et al. (Bone Joint J 96-B:1307-1311, 2014), demonstrated their institutions bank to be cost effective despite a 30 % discard rate for harvested allograft. We sought to audit our own discard rates and subsequent cost-effectiveness of our bone bank. Donor recruitment. Before approaching a potential donor, our establishment's nurse specialists review their clinical notes and biochemical laboratory results, available on a regional Electronic Care Records. They view femoral head architecture on radiographs against set criteria, Patient Archive and Communication system (SECTRA, Sweden). In total 1383 femoral heads were harvested, 247 were discarded giving an overall rate of 17.9 %. The most common reasons for discard of harvested graft was a positive microbiology/bacteriology result, n = 96 (38.9 %). After a rise in discard rates in 2007, we have steadily reduced our discard rates since 2006/2007 (28.2 %), 2008/2009 (17 %), 2010/2011 (14.8 %), and finally to 10.3 % in 2012/2013. In the current financial year, our cost to harvest, test, store and release a femoral head is £ 610. With a structured donor recruitment process and unique pre-operative radiographic analysis we have successfully reduced our discard rates bi-annually making our bone bank increasingly cost-effective.

  7. A control strategy for PV stand-alone applications

    Science.gov (United States)

    Slouma, S.; Baccar, H.

    2015-04-01

    This paper proposes a stand-alone photovoltaic (PV) system study in domestic applications. Because of the decrease in power of photovoltaic module as a consequence of changes in solar radiation and temperature which affect the photovoltaic module performance, the design and control of DC-DC buck converter was proposed for providing power to the load from a photovoltaic source.In fact, the control of this converter is carried out with integrated MPPT (Maximum Power Point Tracking) algorithm which ensures a maximum energy generated by the PV arrays. Moreover, the output stage is composed by a battery energy storage system, dc-ac inverter, LCL filter which enables higher efficiency, low distortion ac waveforms and low leakage currents. The control strategy adopted is cascade control composed by two regulation loops.Simulations performed with PSIM software were able to validate the control system.The realization and testing of the photovoltaic system were achieved in the Photovoltaic laboratory of the Centre for Research and Energy Technologies at the Technopark Borj Cedria. Experimental results verify the effeciency of the proposed system.

  8. The impact of a freshman academy on science performance of first-time ninth-grade students at one Georgia high school

    Science.gov (United States)

    Daniel, Vivian Summerour

    The purpose of this within-group experimental study was to find out to what extent ninth-grade students improved their science performance beyond their middle school science performance at one Georgia high school utilizing a freshman academy model. Freshman academies have been recognized as a useful tool for increasing academic performance among ninth-grade students because they address a range of academic support initiatives tailored to improve academic performance among ninth-grade students. The talent development model developed by Legters, Balfanz, Jordan, and McPartland (2002) has served as a foundational standard for many ninth grade academy programs. A cornerstone feature of this model is the creation of small learning communities used to increase ninth-grade student performance. Another recommendation was to offer credit recovery opportunities for ninth graders along with creating parent and community involvement activities to increase academic success among ninth-grade students. While the site's program included some of the initiatives outlined by the talent development model, it did not utilize all of them. The study concluded that the academy did not show a definitive increase in academic performance among ninth-grade students since most students stayed within their original performance category.

  9. Stand-alone wind system with Vanadium Redox Battery energy storage

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Barote, L.; Weissbach, R.

    2008-01-01

    Energy storage devices are required for power balance and power quality in stand alone wind energy systems. A Vanadium Redox Flow Battery (VRB) system has many features which make its integration with a stand-alone wind energy system attractive. This paper proposes the integration of a VRB system...

  10. Integrated Three-Port DC-DC Converter for Photovoltaic (PV) Battery Stand-alone Systems

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Andersen, Michael A. E.

    2016-01-01

    Several power sources such as PV solar arrays and battery are often used to manage the power flow for a photovoltaic (PV) based stand-alone power system due to the fluctuation nature of solar energy resource, and deliver a continuous power to the users in an appropriate form. Traditionally, three...... for PV and battery stand-alone system....

  11. Integrated versus stand-alone second generation ethanol production from sugarcane bagasse and trash.

    Science.gov (United States)

    Dias, Marina O S; Junqueira, Tassia L; Cavalett, Otávio; Cunha, Marcelo P; Jesus, Charles D F; Rossell, Carlos E V; Maciel Filho, Rubens; Bonomi, Antonio

    2012-01-01

    Ethanol production from lignocellulosic materials is often conceived considering independent, stand-alone production plants; in the Brazilian scenario, where part of the potential feedstock (sugarcane bagasse) for second generation ethanol production is already available at conventional first generation production plants, an integrated first and second generation production process seems to be the most obvious option. In this study stand-alone second generation ethanol production from surplus sugarcane bagasse and trash is compared with conventional first generation ethanol production from sugarcane and with integrated first and second generation; simulations were developed to represent the different technological scenarios, which provided data for economic and environmental analysis. Results show that the integrated first and second generation ethanol production process from sugarcane leads to better economic results when compared with the stand-alone plant, especially when advanced hydrolysis technologies and pentoses fermentation are included. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Stand-alone wind system with Vanadium Redox Battery energy storage

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Barote, L.; Weissbach, R.

    2008-01-01

    Energy storage devices are required for power balance and power quality in stand alone wind energy systems. A Vanadium Redox Flow Battery (VRB) system has many features which make its integration with a stand-alone wind energy system attractive. This paper proposes the integration of a VRB system...... with a typical stand-alone wind energy system during wind speed variation as well as transient performance under variable load. The investigated system consists of a variable speed wind turbine with permanent magnet synchronous generator (PMSG), diode rectifier bridge, buck-boost converter, bidirectional charge...... controller, transformer, inverter, ac loads and VRB (to store a surplus of wind energy and to supply power during a wind power shortage). The main purpose is to supply domestic appliances through a single phase 230V, 50Hz inverter. Simulations are accomplished in order to validate the stability of the supply....

  13. Sensorless direct voltage control of the stand-alone brushless doubly-fed generator

    DEFF Research Database (Denmark)

    Liu, Yi; Xu, Wei; Xiong, Fei

    2017-01-01

    The conventional stand-alone brushless doubly-fed generator (BDFG) control strategies need the feedback from the rotor position or speed sensors, which can reduce system reliability and increase the cost and axial volume of the machine. In this paper, a sensorless direct voltage control (DVC......) strategy is presented for the stand-alone BDFG. The satisfactory dynamic performance is verified by experimental results under four kinds of typical operation conditions. Besides, the proposed control strategy is robust due to no generator parameters being required....

  14. A Current Sensorless MPPT Control Method for a Stand-Alone-Type PV Generation System

    Science.gov (United States)

    Itako, Kazutaka; Mori, Takeaki

    In this paper, a current sensorless MPPT control method for a stand-alone-type PV generation system is proposed. This control method offers advantages of the simplified hardware configuration and the low cost, by using only one sensor to measure the PV output voltage. In the application to stand-alone-type with a battery load, the experimental results show that the estimated values of PV output current are accurate, and the use of the proposed MPPT control increases the PV generated energy by 16.3% compared to the conventional system. Furthermore, it is clarified that the proposed method has extremely high UUF (Useful utilization factor) of 98.7%.

  15. Photovoltaic Module Simulink Model for a Stand-alone PV System

    Science.gov (United States)

    Qi, Chen; Ming, Zhu

    Photovoltaic(PV) Module is indispensable of a stand-alone PV system. In this paper, a one-diode equivalent circuit-based versatile simulation model in the form of masked block PV module is proposed. By the model, it is allowed to estimate behavior of PV module with respect changes on irradiance intensity, ambient temperature and parameters of the PV module. In addition, the model is capable of function of Maximum Power Point Tracking (MPPT) which can be used in the dynamic simulation of stand-alone PV systems.

  16. A control strategy for stand-alone wound rotor induction machine

    Energy Technology Data Exchange (ETDEWEB)

    Forchetti, D.G.; Garcia, G.O. [Grupo de Electronica Aplicada (GEA), Universidad Nacional de Rio Cuarto, X5804 BYA Rio Cuarto (Argentina); Solsona, J.A. [Instituto de Investigaciones en Ingenieria Electrica?Alfredo Desages?, Departamento de Ingenieria Electrica y de Computadoras, Universidad Nacional del Sur, Bahia Blanca (Argentina); Valla, M.I. [Laboratorio de Electronica Industrial, Control e Instrumentacion (LEICI), Facultad de Ingenieria, Universidad Nacional de La Plata, 1900 La Plata (Argentina)

    2007-02-15

    A control strategy to regulate the frequency and voltage of a stand-alone wound rotor induction machine is presented. This strategy allows the machine to work as a generator in stand-alone systems (without grid connection) with variable rotor speed. A stator flux-oriented control is proposed using the rotor voltages as actuation variables. Two cascade control loops are used to regulate the stator flux and the rotor currents. A closed loop observer is designed to estimate the machine flux which is necessary to implement these control loops. The proposed control strategy is validated through simulations with satisfactory results. (author)

  17. Assessment of Stand-Alone Displays for Time Management in a Creativity-Driven Learning Environment

    DEFF Research Database (Denmark)

    Frimodt-Møller, Søren

    2017-01-01

    This paper considers the pros and cons of stand-alone displays, analog (e.g. billboards, blackboards, whiteboards, large pieces of paper etc.) as well as digital (e.g. large shared screens, digital whiteboards or similar), as tools for time management processes in a creativity-driven learning...... to storing information digitally. The findings could indicate a possible market for stand-alone, interactive digital displays combining the ‘touch and feel’ character of an analog board with the convenience of digital data storage....

  18. Stand alone solar energy harvesting and storage systems in off-grid applications

    Science.gov (United States)

    Alonso-Marroquin, Fernando; Gormly, Justin Blake; Bilbao, Jose

    2017-06-01

    The following is an implementation of a stand-alone system for solar energy harvesting and electrical energy storage systems for use in off-grid housing applications. The principal aim of this project was to construct a compact and affordable system for an off-grid house and to monitor its efficiency along the year.

  19. 11kW stand alone wind turbine based on proven wind turbine

    DEFF Research Database (Denmark)

    Bindner, H.; Wodstrup, J.; Andersen, J.

    2004-01-01

    and enable control of frequency and voltage independently on both the grid side and the generator side. The prototype has been installed at Risø. The paper will present results from test runs of the system both operating stand-alone supplying a single load and in parallel operation with a diesel genset....

  20. Linguistic and Structural Analyses of Stand-Alone Literature Reviews: Seventy-Five Years of Change

    Science.gov (United States)

    Wright, Heidi Rachel

    2016-01-01

    The purpose of this dissertation is to offer a multifaceted overview of stand-alone literature reviews. These texts, literature reviews published unattached to research articles, have existed for centuries but remained largely unstudied by linguists. Thus, the goal of this project is to present these reviews' situational, grammatical, and…

  1. Design and Operation Studies of A Stand-Alone PV Generation System

    DEFF Research Database (Denmark)

    Hu, Yanting; Chen, Zhe; Zhang, Donglai

    2013-01-01

    This paper discusses the modeling, design and operation of a PV powered stand-alone system, which includes a PV array, a battery bank, power electronic converters and the associated control system. The design considerations are analyzed and a design platform is presented. Furthermore the operatio...

  2. Clinical outcome of stand-alone ALIF compared to posterior instrumentation for degenerative disc disease

    DEFF Research Database (Denmark)

    Udby, Peter M.; Bech-Azeddine, Rachid

    2015-01-01

    low back pain resulting from degenerative disc disease. ALIF surgery has previously been linked with certain high risk complications and unfavorable long term fusion results. Newer studies suggest that stand-alone ALIF can possibly be advantageous compared to other types of posterior instrumented...

  3. Environmental/Climatic Effect on Stand-Alone Solar Energy Supply ...

    African Journals Online (AJOL)

    This paper investigates the climatic eects and environmental variations on the performance of a stand-alone photovoltaic system. The eects of partial shading with dierent climate conditions and load resistance variations were examined. A survey of some of the work done in this eld of environmental eect on solar panel was ...

  4. MOSFET Loss Evaluation for a Low-Power Stand-Alone Photovoltaic-LED System

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Knott, Arnold; Andersen, Michael A. E.

    2015-01-01

    This paper presents a performance evaluation and comparison of state-of-the-art low voltage Si MOSFETs for a stand-alone photovoltaic-LED Light to Light (LtL) system. The complete system is formed by two cascaded converters that will be optimized for a determined solar irradiation and LED...

  5. Integrated Three-Port DC-DC Converter for Photovoltaic (PV) Battery Stand-alone Systems

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Andersen, Michael A. E.

    2016-01-01

    Several power sources such as PV solar arrays and battery are often used to manage the power flow for a photovoltaic (PV) based stand-alone power system due to the fluctuation nature of solar energy resource, and deliver a continuous power to the users in an appropriate form. Traditionally, three...

  6. Stand-alone version of the 11kW Gaia wind turbine

    DEFF Research Database (Denmark)

    Bindner, H.; Rosas, P.A.C.; Teodorescu, R.

    2004-01-01

    This report describes the development of a stand-alone version of the 11kW Gaia wind turbine. Various possible configurations are investigated and a configuration using a back-to-back converter is chosen. A model is developed for controller design of thefast controllers of the unit. Controllers...... assessment and controller design a dynamic performance assessment model has been developed....

  7. A maximum power point tracking scheme for a 1kw stand-alone ...

    African Journals Online (AJOL)

    A maximum power point tracking scheme for a 1kw stand-alone solar energy based power supply. ... This paper elucidates one of the tracking schemes for a photovoltaic (PV) systems using Cuk converter operating in discontinuous inductor current mode (DICM) as an interface. A method for efficiently maximizing the output ...

  8. Analysis and controller design for stand-alone VSIs in synchronous reference frame

    DEFF Research Database (Denmark)

    Ramezani, Malek; Li, Shuhui; Golestan, Saeed

    2017-01-01

    The common practice for controlling the stand-alone voltage source inverters (VSIs) is to transform abc voltage and current signals to DC signals using the dq transformation, which makes it possible to control the new DC voltage and current signals just using simple proportional-integral controll...

  9. A Control Method for Maximum Power Point Tracking in Stand-Alone-Type PV Generation Systems

    Science.gov (United States)

    Itako, Kazutaka; Mori, Takeaki

    In this paper, a new control method for maximum power point tracking (MPPT) in stand-alone-type PV generaton systems is proposed. In this control method, the operations detecting the maximum power point and tracking its point are alternately carried out by using a step-up DC—DC converter. This method requires neither the measurement of temperature and insolation level nor PV array model. In a stand-alone-type application with a battery load, the design method for the boost inductance L of the step-up DC—DC converter is described, and the experimental results show that the use of the proposed MPPT control increases the PV generated energy by 14.8% compared to the conventional system.

  10. Graft subsidence as a predictor of revision surgery following stand-alone lateral lumbar interbody fusion.

    Science.gov (United States)

    Tempel, Zachary J; McDowell, Michael M; Panczykowski, David M; Gandhoke, Gurpreet S; Hamilton, D Kojo; Okonkwo, David O; Kanter, Adam S

    2018-01-01

    OBJECTIVE Lateral lumbar interbody fusion (LLIF) is a less invasive surgical option commonly used for a variety of spinal conditions, including in high-risk patient populations. LLIF is often performed as a stand-alone procedure, and may be complicated by graft subsidence, the clinical ramifications of which remain unclear. The aim of this study was to characterize further the sequelae of graft subsidence following stand-alone LLIF. METHODS A retrospective review of prospectively collected data was conducted on consecutive patients who underwent stand-alone LLIF between July 2008 and June 2015; 297 patients (623 levels) met inclusion criteria. Imaging studies were examined to grade graft subsidence according to Marchi criteria, and compared between those who required revision surgery and those who did not. Additional variables recorded included levels fused, DEXA (dual-energy x-ray absorptiometry) T-score, body mass index, and routine demographic information. The data were analyzed using the Student t-test, chi-square analysis, and logistic regression analysis to identify potential confounding factors. RESULTS Of 297 patients, 34 (11.4%) had radiographic evidence of subsidence and 18 (6.1%) required revision surgery. The median subsidence grade for patients requiring revision surgery was 2.5, compared with 1 for those who did not. Chi-square analysis revealed a significantly higher incidence of revision surgery in patients with high-grade subsidence compared with those with low-grade subsidence. Seven of 18 patients (38.9%) requiring revision surgery suffered a vertebral body fracture. High-grade subsidence was a significant predictor of the need for revision surgery (p subsidence following stand-alone LLIF required revision surgery. When evaluating patients for LLIF, supplemental instrumentation should be considered during the index surgery in patients with a significant risk of graft subsidence.

  11. A Three-Port Topology Comparison for a Low Power Stand-Alone Photovoltaic System

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    Three-port converter (TPC) topologies for renewable energy systems aim to provide higher efficiency and power density than conventional cascaded structures. This work proposes an analytical comparison of different TPC topologies for a photovoltaic LED lamp stand-alone system. A comparison using...... component stress factor (CSF) is performed, which gives a quantitative measure of the performance of the converter. The candidate topologies are compared to each other according to a defined LED lighting strategy and a solar irradiation profile....

  12. Secure stand alone positive personnel identity verification system (SSA-PPIV)

    International Nuclear Information System (INIS)

    Merillat, P.D.

    1979-03-01

    The properties of a secure stand-alone positive personnel identity verification system are detailed. The system is designed to operate without the aid of a central computing facility and the verification function is performed in the absence of security personnel. Security is primarily achieved by means of data encryption on a magnetic stripe badge. Several operational configurations are discussed. Advantages and disadvantages of this system compared to a central computer driven system are detailed

  13. Modeling, Design and Simulation of Stand-Alone Photovoltaic Power Systems with Battery Storage

    Directory of Open Access Journals (Sweden)

    Abd Essalam BADOUD

    2013-06-01

    Full Text Available Stand alone renewable energy based on photovoltaic systems accompanied with battery storage system are beginning to play an important role over the world to supply power to remote areas. The objective of the study reported in this paper is to elaborate and design a bond graphs model for sizing stand-alone domestic solar photovoltaic electricity systems and simulating the performance of the systems in a tropical climate. The systems modelled consist of an array of PV modules, a lead-acid battery, and a number of direct current appliances. This paper proposes the combination of lead acid battery system with a typical stand alone photovoltaic energy system under variable loads. The main activities of this work purpose to establish library graphical models for each individual component of standalone photovoltaic system. Control strategy has been considered to achieve permanent power supply to the load via photovoltaic/battery based on the power available from the sun. The complete model was simulated under two testing including sunny and cloudy conditions. Simulation of the system using Symbols software was performed and the results of simulation show the superior stable control system and high efficiency. These results have been contrasted with real measured data from a measurement campaign plant carried on electrical engineering laboratory of Grenoble using various interconnection schemes are presented.

  14. Subsidence after single-level anterior cervical fusion with a stand-alone cage.

    Science.gov (United States)

    Park, Jae-Young; Choi, Ki-Young; Moon, Bong Ju; Hur, Hyuk; Jang, Jae-Won; Lee, Jung-Kil

    2016-11-01

    To investigate the risk factors for subsidence in patients treated with stand-alone anterior cervical discectomy and fusion (ACDF) using polyetheretherketone (PEEK) cages for single-level degenerative cervical disease. Seventy-seven consecutive patients who underwent single-level stand-alone ACDF with a PEEK cage between 2005 and 2012 were included. Subsidence was defined as a decrease in the interbody height of more than 3mm on radiographs at the 1-year follow-up compared with that in the immediate post-operative image. Patients were divided into the subsidence and non-subsidence groups. The following factors were investigated in relation to the occurrence of subsidence: age, pre-operative overall cervical sagittal angle, segmental angle of the operated level, interbody height, cage height, cage devices and cage location (distance between anterior margin of the body endplate and that of the cage). The clinical outcomes were assessed with visual analog scale, modified Japanese Orthopedic Association score and neck disability index. Twenty-six out of the 77 (33.8%) patients had radiological signs of cage subsidence. Solid fusion was achieved in 25 out of the 26 patients (96.2%) in the subsidence group and in 47 out of the 51 patients (92.2%) in the non-subsidence group. More than 3mm distance between anterior margin of the vertebral body and that of the cage was significantly associated with subsidence (psubsidence did not correlate with fusion rate or clinical outcomes. Cage location was the only significant risk factor. Therefore, cage location should be taken into consideration during stand-alone ACDF using PEEK cages. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. A Simple Sizing Algorithm for Stand-Alone PV/Wind/Battery Hybrid Microgrids

    Directory of Open Access Journals (Sweden)

    Jing Li

    2012-12-01

    Full Text Available In this paper, we develop a simple algorithm to determine the required number of generating units of wind-turbine generator and photovoltaic array, and the associated storage capacity for stand-alone hybrid microgrid. The algorithm is based on the observation that the state of charge of battery should be periodically invariant. The optimal sizing of hybrid microgrid is given in the sense that the life cycle cost of system is minimized while the given load power demand can be satisfied without load rejection. We also report a case study to show the efficacy of the developed algorithm.

  16. Stand-alone and Interdisciplinary Course Design for Engineering Education for Sustainable Development

    DEFF Research Database (Denmark)

    Arsat, M.; Holgaard, Jette Egelund; de Graaff, Erik

    In order to embed ESD in the EE curriculum, several approaches has been introduced and practiced in higher education institutions. One of the approaches is to introduce a new ESD course as an add-on to the existing curriculum being either compulsory or elective and either designed for a single...... and reported examples of other ESD courses of the same kind. The presented conceptual framework is put to practice, characterising the AAU course as a stand-alone interdisciplinary course with a consensual approach. The conclusion is that the conceptual framework can provide an awareness of the design features...

  17. Information systems for the materials management department: stand-alone and enterprise resource planning systems.

    Science.gov (United States)

    2005-03-01

    Materials management information systems (MMISs) incorporate information tools that hospitals can use to automate certain business processes, increase staff compliance with these processes, and identify opportunities for cost savings. Recently, there has been a push by hospital administration to purchase enterprise resource planning (ERP) systems, information systems that promise to integrate many more facets of healthcare business. We offer this article to help materials managers, administrators, and others involved with information system selection understand the changes that have taken place in materials management information systems, decide whether they need a new system and, if so, whether a stand-alone MMIS or an ERP system will be the best choice.

  18. Solar Photovoltaic Applications Seminar: Design, installation and operation of small, stand-alone photovoltaic power systems

    Science.gov (United States)

    1980-07-01

    An introduction to photoconductivity, semiconductors, and solar photovoltaic cells is included along with a demonstration of specific applications and application identification. Small solar cell power system design engineering is discussed. Solar PV power system applications involve classical direct electrical energy conversion and electric power system analysis and synthesis. Presentations and examples involve a variety of disciplines including structural analysis, electric power and load analysis, reliability, sizing and optimization; and, installation, operation and maintenance. Four specific system designs are demonstrated: water pumping; domestic uses; navigational and aircraft aids; and telecommunications. All of the applications discussed are for small power requirement (under 2 kilowatts), stand alone systems to be used in remote locations.

  19. Incidence and impact of implant subsidence after stand-alone lateral lumbar interbody fusion.

    Science.gov (United States)

    Bocahut, N; Audureau, E; Poignard, A; Delambre, J; Queinnec, S; Flouzat Lachaniette, C-H; Allain, J

    2017-12-30

    Few data are available on the occurrence after stand-alone lateral lumbar interbody fusion (LLIF) of implant subsidence, whose definition and incidence vary across studies. The primary objective of this work was to determine the incidence of subsidence 1 year postoperatively, using an original measurement method, whose validity was first assessed. The secondary objective was to assess the clinical impact of subsidence. Implant subsidence after stand-alone LLIF is a common complication that can adversely affect clinical outcomes. Of 69 included patients who underwent stand-alone LLIF, 67 (97%) were re-evaluated at least 1 year later. Furthermore, 63 (91%) patients had two available computed tomography (CT) scans for assessing subsidence, one performed immediately after surgery and the other 1 year later. Reproducibility of the original measurement method was assessed in a preliminary study. Subsidence was defined as at least 4mm loss of fused space height. The incidence of subsidence was 32% (20 patients). Subsidence was global in 7 (11%) patients and partial in 13 (21%) patients. Mean loss of height was 5.5±1.5mm. Subsidence predominated anteriorly in 50% of cases. The lordotic curvature of the fused segment was altered in 50% of patients, by a mean of 8°±3°. Fusion was achieved in 67/69 (97%) patients. The Oswestry score and visual analogue scale scores for low-back and nerve-root pain were significantly improved after 1 year in the overall population and in the groups with and without subsidence. Reproducibility of our measurement method was found to be excellent. Subsidence was common but without significant clinical effects after 1 year. Nevertheless, subsidence can be associated with pain and can result in loss of lumbar lordosis, which is a potential risk factor for degenerative disease of the adjacent segments. A score for predicting the risk of subsidence will now be developed by our group as a tool for improving patient selection to stand-alone LLIF

  20. Boost converter with combined control loop for a stand-alone photovoltaic battery charge system

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Knott, Arnold; Thomsen, Ole Cornelius

    2013-01-01

    frequency avoids perturbations in the load being propagated to the photovoltaic panel and thus deviating the operating point. Linearization of the photovoltaic panel and converter state-space modeling is performed. In order to achieve stable operation under all operating conditions, the photovoltaic panel......The converter control scheme plays an important role in the performance of maximum power point tracking (MPPT) algorithms. In this paper, an input voltage control with double loop for a stand-alone photovoltaic system is designed and tested. The inner current control loop with high crossover...

  1. Feasibility and Optimal Design of a Stand-Alone Photovoltaic Energy System for the Orphanage

    Directory of Open Access Journals (Sweden)

    Vincent Anayochukwu Ani

    2014-01-01

    Full Text Available Access to electricity can have a positive psychological impact through a lessening of the sense of exclusion, and vulnerability often felt by the orphanages. This paper presented the simulation and optimization study of a stand-alone photovoltaic power system that produced the desired power needs of an orphanage. Solar resources for the design of the system were obtained from the National Aeronautics and Space Administration (NASA Surface Meteorology and Solar Energy website at a location of 6°51′N latitude and 7°35′E longitude, with annual average solar radiation of 4.92 kWh/m2/d. This study is based on modeling, simulation, and optimization of energy system in the orphanage. The patterns of load consumption within the orphanage were studied and suitably modeled for optimization. Hybrid Optimization Model for Electric Renewables (HOMER software was used to analyze and design the proposed stand-alone photovoltaic power system model. The model was designed to provide an optimal system configuration based on an hour-by-hour data for energy availability and demands. A detailed design, description, and expected performance of the system were presented in this paper.

  2. Coordination Control Strategy for AC/DC Hybrid Microgrids in Stand-Alone Mode

    Directory of Open Access Journals (Sweden)

    Dwi Riana Aryani

    2016-06-01

    Full Text Available Interest in DC microgrids is rapidly increasing along with the improvement of DC power technology because of its advantages. To support the integration process of DC microgrids with the existing AC utility grids, the form of hybrid AC/DC microgrids is considered for higher power conversion efficiency, lower component cost and better power quality. In the system, AC and DC portions are connected through interlink bidirectional AC/DC converters (IC with a proper control system and power management. In the stand-alone operation mode of AC/DC hybrid microgrids, the control of power injection through the IC is crucial in order to maintain the system security. This paper mainly deals with a coordination control strategy of IC and a battery energy storage system (BESS converter under stand-alone operation. A coordinated control strategy for the IC, which considers the state of charge (SOC level of BESS and the load shedding scheme as the last resort, is proposed to obtain better power sharing between AC and DC subgrids. The scheme will be tested with a hybrid AC/DC microgrid, using the tool of the PSCAD/EMTDC software.

  3. Fuzzy logic control of stand-alone photovoltaic system with battery storage

    Science.gov (United States)

    Lalouni, S.; Rekioua, D.; Rekioua, T.; Matagne, E.

    Photovoltaic energy has nowadays an increased importance in electrical power applications, since it is considered as an essentially inexhaustible and broadly available energy resource. However, the output power provided via the photovoltaic conversion process depends on solar irradiation and temperature. Therefore, to maximize the efficiency of the photovoltaic energy system, it is necessary to track the maximum power point of the PV array. The present paper proposes a maximum power point tracker (MPPT) method, based on fuzzy logic controller (FLC), applied to a stand-alone photovoltaic system. It uses a sampling measure of the PV array power and voltage then determines an optimal increment required to have the optimal operating voltage which permits maximum power tracking. This method carries high accuracy around the optimum point when compared to the conventional one. The stand-alone photovoltaic system used in this paper includes two bi-directional DC/DC converters and a lead-acid battery bank to overcome the scare periods. One converter works as an MPP tracker, while the other regulates the batteries state of charge and compensates the power deficit to provide a continuous delivery of energy to the load. The Obtained simulation results show the effectiveness of the proposed fuzzy logic controller.

  4. International market assessment of stand-alone photovoltaic power systems for cottage industry applications

    Science.gov (United States)

    Philippi, T. M.

    1981-01-01

    The final result of an international assessment of the market for stand-alone photovoltaic systems in cottage industry applications is reported. Nonindustrialized countries without centrally planned economies were considered. Cottage industries were defined as small rural manufacturers, employing less than 50 people, producing consumer and simple products. The data to support this analysis were obtained from secondary and expert sources in the U.S. and in-country field investigations of the Philippines and Mexico. The near-term market for photovoltaics for rural cottage industry applications appears to be limited to demonstration projects and pilot programs, based on an in-depth study of the nature of cottage industry, its role in the rural economy, the electric energy requirements of cottage industry, and a financial analysis of stand-alone photovoltaic systems as compared to their most viable competitor, diesel driven generators. Photovoltaics are shown to be a better long-term option only for very low power requirements. Some of these uses would include clay mixers, grinders, centrifuges, lathes, power saws and lighting of a workshop.

  5. A sizing method for stand-alone PV installations with variable demand

    Energy Technology Data Exchange (ETDEWEB)

    Posadillo, R. [Grupo de Investigacion en Energias y Recursos Renovables, Dpto. de Fisica Aplicada, E.P.S., Universidad de Cordoba, Avda. Menendez Pidal s/n, 14004 Cordoba (Spain); Lopez Luque, R. [Grupo de Investigacion de Fisica Para las Energias y Recursos Renovables, Dpto. de Fisica Aplicada, Edificio C2 Campus de Rabanales, 14071 Cordoba (Spain)

    2008-05-15

    The practical applicability of the considerations made in a previous paper to characterize energy balances in stand-alone photovoltaic systems (SAPV) is presented. Given that energy balances were characterized based on monthly estimations, the method is appropriate for sizing installations with variable monthly demands and variable monthly panel tilt (for seasonal estimations). The method presented is original in that it is the only method proposed for this type of demand. The method is based on the rational utilization of daily solar radiation distribution functions. When exact mathematical expressions are not available, approximate empirical expressions can be used. The more precise the statistical characterization of the solar radiation on the receiver module, the more precise the sizing method given that the characterization will solely depend on the distribution function of the daily global irradiation on the tilted surface H{sub g{beta}}{sub i}. This method, like previous ones, uses the concept of loss of load probability (LLP) as a parameter to characterize system design and includes information on the standard deviation of this parameter ({sigma}{sub LLP}) as well as two new parameters: annual number of system failures (f) and the standard deviation of annual number of system failures ({sigma}{sub f}). This paper therefore provides an analytical method for evaluating and sizing stand-alone PV systems with variable monthly demand and panel inclination. The sizing method has also been applied in a practical manner. (author)

  6. Method to size photovoltaic arrays for hydrogen-PV stand-alone power stations

    Energy Technology Data Exchange (ETDEWEB)

    Barra, L.; Coiante, D. [ENEA, Casaccia (Italy). Area Energetica

    1993-11-01

    With reference to a stand alone power plant configuration, a photovoltaic (PV) system, integrated with an electrolytic hydrogen production and fuel cell reconversion line, is examined with the aim of checking the possibility of assuring energy supply for a given load with time continuity. In order to size the PV array in function of the annual load diagram, for a given site, a method, which utilizes the monthly average values of sun energy density collected on horizontal surface as input data, is presented. The results demonstrate that a PV-H{sub 2} system is suitable for a modular stand alone solar power station, able to supply continuously each generic load. This technical acquisition has to be considered as the first necessary condition to get photovoltaics to overcome the limit due to working intermittence and become a real energy option. An example of an application for a small Mediterranean island, the Volcano Island, permanently inhabited by 469 people, is also discussed. This typical case can be actually show the technical viability of the PV-H{sub 2} solution in powering a small community with the required reliability.

  7. Robust Power Management Control for Stand-Alone Hybrid Power Generation System

    International Nuclear Information System (INIS)

    Kamal, Elkhatib; Adouane, Lounis; Aitouche, Abdel; Mohammed, Walaa

    2017-01-01

    This paper presents a new robust fuzzy control of energy management strategy for the stand-alone hybrid power systems. It consists of two levels named centralized fuzzy supervisory control which generates the power references for each decentralized robust fuzzy control. Hybrid power systems comprises: a photovoltaic panel and wind turbine as renewable sources, a micro turbine generator and a battery storage system. The proposed control strategy is able to satisfy the load requirements based on a fuzzy supervisor controller and manage power flows between the different energy sources and the storage unit by respecting the state of charge and the variation of wind speed and irradiance. Centralized controller is designed based on If-Then fuzzy rules to manage and optimize the hybrid power system production by generating the reference power for photovoltaic panel and wind turbine. Decentralized controller is based on the Takagi-Sugeno fuzzy model and permits us to stabilize each photovoltaic panel and wind turbine in presence of disturbances and parametric uncertainties and to optimize the tracking reference which is given by the centralized controller level. The sufficient conditions stability are formulated in the format of linear matrix inequalities using the Lyapunov stability theory. The effectiveness of the proposed Strategy is finally demonstrated through a SAHPS (stand-alone hybrid power systems) to illustrate the effectiveness of the overall proposed method. (paper)

  8. Photovoltaic OLED Driver for Low-Power Stand-Alone Light-to-Light Systems

    DEFF Research Database (Denmark)

    Ploug, Rasmus Overgaard; Knott, Arnold

    2016-01-01

    Photovoltaic (PV) stand-alone systems need to achieve multiple energy conversion modes. I.e. the energy conversion from PV to a local energy storage as well as energy conversion from the energy storage to the load. This paper documents the practical design considerations for the development of a ...... conversion from photovoltaic panel to the battery, and 97 % in the area 1.4 W to 2 W for power delivery to the OLED.......Photovoltaic (PV) stand-alone systems need to achieve multiple energy conversion modes. I.e. the energy conversion from PV to a local energy storage as well as energy conversion from the energy storage to the load. This paper documents the practical design considerations for the development...... of a three-port-converter for this purpose optimized for the specifications for driving an Organic Light Emitting Diode (OLED) panel intended for lighting purposes. By using a three-port-converter, featuring shared components for each conversion mode, the converter reaches 97 % efficiency at 1.8 W during...

  9. Modified Chaos Particle Swarm Optimization-Based Optimized Operation Model for Stand-Alone CCHP Microgrid

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2017-07-01

    Full Text Available The optimized dispatch of different distributed generations (DGs in stand-alone microgrid (MG is of great significance to the operation’s reliability and economy, especially for energy crisis and environmental pollution. Based on controllable load (CL and combined cooling-heating-power (CCHP model of micro-gas turbine (MT, a multi-objective optimization model with relevant constraints to optimize the generation cost, load cut compensation and environmental benefit is proposed in this paper. The MG studied in this paper consists of photovoltaic (PV, wind turbine (WT, fuel cell (FC, diesel engine (DE, MT and energy storage (ES. Four typical scenarios were designed according to different day types (work day or weekend and weather conditions (sunny or rainy in view of the uncertainty of renewable energy in variable situations and load fluctuation. A modified dispatch strategy for CCHP is presented to further improve the operation economy without reducing the consumers’ comfort feeling. Chaotic optimization and elite retention strategy are introduced into basic particle swarm optimization (PSO to propose modified chaos particle swarm optimization (MCPSO whose search capability and convergence speed are improved greatly. Simulation results validate the correctness of the proposed model and the effectiveness of MCPSO algorithm in the optimized operation application of stand-alone MG.

  10. Stand-alone anterior lumbar interbody fusion for treatment of degenerative spondylolisthesis.

    Science.gov (United States)

    Rao, Prashanth J; Ghent, Finn; Phan, Kevin; Lee, Keegan; Reddy, Rajesh; Mobbs, Ralph J

    2015-10-01

    We sought to evaluate the clinical and radiologic efficacy of stand-alone anterior lumbar interbody fusion (ALIF) for low grade degenerative spondylolisthesis, the favoured surgical management approach at our institution. The optimal approach for surgical management of spondylolisthesis remains contentious. We performed a prospective analysis of all consecutive patients with low grade lumbar spondylolisthesis who underwent ALIF between 2009 and 2013 by a single surgeon (n=27). The mean age was 64.9 years with a male to female ratio of 14:13. There were 32 levels operated and the average preoperative spondylolisthesis was 14.8%, which reduced to 6.4% postoperatively and 9.4% at the latest follow-up (p=0001). Postoperative disc height was increased to 175% of preoperative values and was statistically significant (pspondylolisthesis reduction (p=0.04) and the only clinical factor affecting reduction was body mass index (p=0.04). The present study provides encouraging short term results for stand-alone ALIF as a procedure for low grade lumbar degenerative spondylolisthesis. Future studies should include adequately powered, prospective, multicentre registry studies with long term follow-up to allow a better assessment of the relative benefits and risks. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. International market assessment of stand-alone photovoltaic power systems for cottage industry applications

    Science.gov (United States)

    Philippi, T. M.

    1981-11-01

    The final result of an international assessment of the market for stand-alone photovoltaic systems in cottage industry applications is reported. Nonindustrialized countries without centrally planned economies were considered. Cottage industries were defined as small rural manufacturers, employing less than 50 people, producing consumer and simple products. The data to support this analysis were obtained from secondary and expert sources in the U.S. and in-country field investigations of the Philippines and Mexico. The near-term market for photovoltaics for rural cottage industry applications appears to be limited to demonstration projects and pilot programs, based on an in-depth study of the nature of cottage industry, its role in the rural economy, the electric energy requirements of cottage industry, and a financial analysis of stand-alone photovoltaic systems as compared to their most viable competitor, diesel driven generators. Photovoltaics are shown to be a better long-term option only for very low power requirements. Some of these uses would include clay mixers, grinders, centrifuges, lathes, power saws and lighting of a workshop.

  12. Design of a Stand-Alone Photovoltaic Model for Home Lightings and Clean Environment

    International Nuclear Information System (INIS)

    Ani, Vincent Anayochukwu

    2016-01-01

    This paper gives a well-documented health risk of fuel-based lighting (kerosene lamps and fuel-powered generators) and proposed a design of a stand-alone solar PV system for sustainable home lightings in rural Nigerian area. The design was done in three different patterns of electricity consumptions with energy efficient lightings (EELs) using two different battery types (Rolls Surrette 6CS25PS and Hoppecke 10 OpzS 1000) on; (i) judicious power consumption, (ii) normal power consumption, and (iii) excess power consumption; and compared them with the incandescent light bulb consumption. The stand-alone photovoltaic energy systems were designed to match the rural Nigerian sunlight and weather conditions to meet the required lightings of the household. The objective function and constraints for the design models were formulated and optimization procedures were used to demonstrate the best solution (reliability at the lowest lifecycle cost). Initial capital costs as well as annualized costs over 5, 10, 15, 20, and 25 years were quantified and documented. The design identified the most cost-effective and reliable solar and battery array among the patterns of electricity consumption with EEL options (judicious power consumption, normal power consumption, and excess power consumption).

  13. Simulation of stand alone PV systems; Dokuritsugata taiyoko hatsuden system no simulation

    Energy Technology Data Exchange (ETDEWEB)

    Tsuda, I.; Sakuta, K. [Electrotechnical Laboratory, Tsukuba (Japan); Oshiro, T. [Japan Quality Assurance Organization, Tokyo (Japan); Kurokawa, K. [Tokyo University of Agriculture and Technology, Tokyo (Japan)

    1997-11-25

    Studies are performed to develop a simulation program for a stand-alone photovoltaic power generation system equipped with a lead acid battery. In this stand-alone photovoltaic power generation system, the load is connected in shunt with the solar cell array output through the intermediary of a lead acid battery and inverter. The program is a model in which the solar cell model is built taking parallel resistance into account, and the temperature-dependence of the constants is described using approximations experimentally obtained by Solar Techno Center of JQA (Japan Quality Assurance Organization), Hamamatsu. Insolation data for the model is described using METPV compiled by Japan Weather Association, and load data is described using data actually measured at Shizuoka. This program is compared with the data of operation at Hamamatsu, and the result is almost satisfactory. Simulations are conducted at five typical locations in Japan using this program, and it is found that the array load matching correction factor is dependent on seasonal changes rather than locality, that the battery contribution rate does not change much throughout the year, and that it is not dependent on locality. 5 refs., 7 figs., 3 tabs.

  14. Design of a Stand-Alone Photovoltaic (PV Models for Home Lightings and Clean Environment

    Directory of Open Access Journals (Sweden)

    Vincent Anayochukwu Ani

    2016-01-01

    Full Text Available This paper gives a well-documented health risks of fuel-based lighting (kerosene lamps and fuel-powered generators and proposed a design of a stand-alone solar PV system for sustainable home lightings in rural Nigerian area. The design was done in three different patterns of electricity consumptions with energy efficient lightings (EELs using two different battery types (Rolls Surrette 6CS25PS and hoppecke 10 OpzS 1000 on; i judicious power consumption, ii normal power consumption, iii excess power consumption; and compared them with the incandescent light bulb consumption. The stand-alone photovoltaic energy systems were designed to match the rural Nigerian sunlight and weather conditions to meet the required lightings of the household. The objective function and constraints for the design models were formulated and optimization procedure were used to demonstrate the best solution (reliability at the lowest lifecycle cost. Initial capital costs as well as annualized costs over 5, 10, 15, 20, and 25 years were quantified and documented. The design identified the most cost-effective and reliable solar and battery array among the patterns of electricity consumption with energy efficient lighting options (judicious power consumption, normal power consumption, and excess power consumption.

  15. Design of Stand-Alone Hybrid Power Generation System at Brumbun Beach Tulungagung East Java

    Science.gov (United States)

    Rahmat, A. N.; Hidayat, M. N.; Ronilaya, F.; Setiawan, A.

    2018-04-01

    Indonesian government insists to optimize the use of renewable energy resources in electricity generation. One of the efforts is launching Independent Energy Village plan. This program aims to fulfill the need of electricity for isolated or remote villages in Indonesia. In order to support the penetration of renewable energy resources in electricity generation, a hybrid power generation system is developed. The simulation in this research is based on the availability of renewable energy resources in Brumbun beach, Tulungagung, East Java. Initially, the electricity was supplied through stand-alone electricity generations which are installed at each house. Hence, the use of electricity between 5 p.m. – 9 p.m. requires high operational costs. Based on the problem above, this research is conducted to design a stand-alone hybrid electricity generation system, which may consist of diesel, wind, and photovoltaic. The design is done by using HOMER software to optimize the use of electricity from renewable resources and to reduce the operation of diesel generation. The combination of renewable energy resources in electricity generation resulted in NPC of 44.680, COE of 0,268, and CO2 emissions of 0,038 % much lower than the use of diesel generator only.

  16. Subsidence and nonunion after anterior cervical interbody fusion using a stand-alone polyetheretherketone (PEEK) cage.

    Science.gov (United States)

    Yang, Jae Jun; Yu, Chang Hun; Chang, Bong-Soon; Yeom, Jin Sup; Lee, Jae Hyup; Lee, Choon-Ki

    2011-03-01

    The purposes of the present study are to evaluate the subsidence and nonunion that occurred after anterior cervical discectomy and fusion using a stand-alone intervertebral cage and to analyze the risk factors for the complications. Thirty-eight patients (47 segments) who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage and an autologous cancellous iliac bone graft from June 2003 to August 2008 were enrolled in this study. The anterior and posterior segmental heights and the distance from the anterior edge of the upper vertebra to the anterior margin of the cage were measured on the plain radiographs. Subsidence was defined as ≥ a 2 mm (minor) or 3 mm (major) decrease of the segmental height at the final follow-up compared to that measured at the immediate postoperative period. Nonunion was evaluated according to the instability being ≥ 2 mm in the interspinous distance on the flexion-extension lateral radiographs. The anterior and posterior segmental heights decreased from the immediate postoperative period to the final follow-up at 1.33 ± 1.46 mm and 0.81 ± 1.27 mm, respectively. Subsidence ≥ 2 mm and 3 mm were observed in 12 segments (25.5%) and 7 segments (14.9%), respectively. Among the expected risk factors for subsidence, a smaller anteroposterior (AP) diameter (14 mm vs. 12 mm) of cages (p = 0.034; odds ratio [OR], 0.017) and larger intraoperative distraction (p = 0.041; OR, 3.988) had a significantly higher risk of subsidence. Intervertebral nonunion was observed in 7 segments (7/47, 14.9%). Compared with the union group, the nonunion group had a significantly higher ratio of two-level fusion to one-level fusions (p = 0.001). Anterior cervical fusion using a stand-alone cage with a large AP diameter while preventing anterior intraoperative over-distraction will be helpful to prevent the subsidence of cages. Two-level cervical fusion might require more careful attention for avoiding nonunion.

  17. Charactrization of a Li-ion battery based stand-alone a-Si photovoltaic system

    International Nuclear Information System (INIS)

    Hamid Vishkasougheh, Mehdi; Tunaboylu, Bahadir

    2014-01-01

    Highlights: • An Li-ion battery based stand-alone a-Si PV was designed. The system composed of three a-Si panels with an efficiency of 7% and 40 cells of LFP batteries. • Effects of solar radiation and environmental temperature for three cities, Istanbul, Ankara, and Adana, have been investigated on a-Si panels. • Using transition formulas BSPV outputs are predictable for any location out of standard test condition. - Abstract: The number of photovoltaic (PV) system installations is increasing rapidly. As more people learn about this versatile and often cost-effective power option, this trend will accelerate. This document presents a recommended design for a battery based stand-alone photovoltaic system (BSPV). BSPV system has the ability to be applied in different areas, including warning signals, lighting, refrigeration, communication, residential water pumping, remote sensing, and cathodic protection. The presented calculation method gives a proper idea for a system sizing technique. Based on application load, different scenarios are possible for designing a BSPV system. In this study, a battery based stand-alone system was designed. The electricity generation part is three a-Si panels, which are connected in parallel, and for the storage part LFP (lithium iron phosphate) battery was used. The high power LFP battery packs are 40 cells each 8S5P (configured 8 series 5 parallel). Each individual pack weighs 0.5 kg and is 25.6 V. In order to evaluate the efficiency of a-Si panels with respect to the temperature and the solar irradiation, cities of Istanbul, Ankara and Adana in Turkey were selected. Temperature and solar irradiation were gathered from reliable sources and by using translation equations, current and voltage output of panels were calculated. As a result of these calculations, current and energy outputs were computed by considering an average efficient solar irradiation time value per day in Turkey. The calculated power values were inserted to a

  18. Stand-alone differential capacitance force sensors with sub-nano-newton sensitivity

    Science.gov (United States)

    Ye, Jilong; Sun, Taotao; Huang, Dong; Li, Zhihong; Lin, Li

    2017-09-01

    This paper presents structure design, microfabrication processes, calibration techniques and experimental results of differential capacitance force sensors with features of sub-nano-newton sensitivity, up to 10 000 Hz sampling rate, and applicability as stand-alone devices. The representative sensor demonstrates a force resolution of 0.11 nN at a 19 Hz sampling rate or 1.47 nN at 10 000 Hz. A novel asymmetric differential capacitance structure proposed results in remarkable increase in the ratio of measurement range to resolution in comparison with traditional symmetric structure. In addition, the stiction between silicon and glass caused by the capillary force during dicing is eliminated by the use of hydrophobization treatment. Such a treatment is essential to successfully fabricate structures with a large ratio of overlapped area to gap in silicon/glass anodic bonding processes.

  19. Lossy Data Aggregation with Network Coding in Stand-Alone Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Madsen, Tatiana Kozlova

    2011-01-01

    This work focuses on a special type of wireless sensor networks (WSNs) that we refer to as a stand alone network. These netwoks operate in harsh and extreme environments where data collection is done only occasionally. Typical examples include habitat monitoring systems, monitoring systems...... in chemical plants, etc. Given resource constrained operation of a sensor network where the nodes are battery powered and buffer sizes are limited, efficient methods for in-network data storage abd it subsequent fast and reliable transmission to a gateway is desirable. To save scarse resources and to prolong...... the lifetime of the whole network, the lossy data grregation method can be applied. It is especially viable in the networks where several sensors are measuring the same physical phenomenum and only average values of sensor readings are of interest. In this paper we present a method for efficient lossy data...

  20. Study of Stand-Alone Microgrid under Condition of Faults on Distribution Line

    Science.gov (United States)

    Malla, S. G.; Bhende, C. N.

    2014-10-01

    The behavior of stand-alone microgrid is analyzed under the condition of faults on distribution feeders. During fault since battery is not able to maintain dc-link voltage within limit, the resistive dump load control is presented to do so. An inverter control is proposed to maintain balanced voltages at PCC under the unbalanced load condition and to reduce voltage unbalance factor (VUF) at load points. The proposed inverter control also has facility to protect itself from high fault current. Existing maximum power point tracker (MPPT) algorithm is modified to limit the speed of generator during fault. Extensive simulation results using MATLAB/SIMULINK established that the performance of the controllers is quite satisfactory under different fault conditions as well as unbalanced load conditions.

  1. Solar pv fed stand-alone excitation system of a synchronous machine for reactive power generation

    Science.gov (United States)

    Sudhakar, N.; Jain, Siddhartha; Jyotheeswara Reddy, K.

    2017-11-01

    This paper presents a model of a stand-alone solar energy conversion system based on synchronous machine working as a synchronous condenser in overexcited state. The proposed model consists of a Synchronous Condenser, a DC/DC boost converter whose output is fed to the field of the SC. The boost converter is supplied by the modelled solar panel and a day time variable irradiance is fed to the panel during the simulation time. The model also has one alternate source of rechargeable batteries for the time when irradiance falls below a threshold value. Also the excess power produced when there is ample irradiance is divided in two parts and one is fed to the boost converter while other is utilized to recharge the batteries. A simulation is done in MATLAB-SIMULINK and the obtained results show the utility of such modelling for supplying reactive power is feasible.

  2. An Analysis of Stand-alone GPS Quality and Simulated GNSS Quality for Road Pricing

    DEFF Research Database (Denmark)

    Zabic, Martina; Nielsen, Otto Anker

    2006-01-01

    Use of GPS for road pricing has often been suggested as the way of creating more efficient charging strategies than existing systems based on cordon lines or time use. In Denmark, Copenhagen participated with the AKTA project in the PRoGRESS programme, sponsored by the EU. The major part...... of the AKTA project was to equip 500 cars with GPS receivers. The paper presents the methods and results from a study of GPS quality in relation to road pricing in a dense urban area. The collected data from 500 cars over a two-year period in the Copenhagen region was analyzed in order to determine whether...... the stand alone GPS quality and reliability is adequate for implementation of an operational road pricing system in Copenhagen. The results from the analysis show that the satellite availability in Copenhagen is not sufficient to form the basis for a reliable operational road pricing system. The narrow...

  3. Electrical integration of renewable energy into stand-alone power supplies incorporating hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Little, Matthew; Thomson, Murray

    2007-07-15

    A stand-alone renewable-energy system employing a hydrogen-based energy store is now being commissioned within the HaRI project at West Beacon Farm, Leicestershire, UK. The interconnection of the various generators, loads and storage system is made through a central DC busbar: an arrangement that is believed to be unique within systems of this type and scale. The rotating generators, such as the wind turbines, are connected through standard industrial drives operating in regenerative mode, while the DC devices - electrolyser, fuel cell and solar photovoltaic array - employ custom DC-DC converters. This paper reviews the design philosophy of the electrical system and the various converters required. Modelling and simulation of the system is discussed along with practical lessons learnt from its implementation and some initial results are presented. (author)

  4. System Simulation by Recursive Feedback: Coupling a Set of Stand-Alone Subsystem Simulations

    Science.gov (United States)

    Nixon, D. D.

    2001-01-01

    Conventional construction of digital dynamic system simulations often involves collecting differential equations that model each subsystem, arran g them to a standard form, and obtaining their numerical gin solution as a single coupled, total-system simultaneous set. Simulation by numerical coupling of independent stand-alone subsimulations is a fundamentally different approach that is attractive because, among other things, the architecture naturally facilitates high fidelity, broad scope, and discipline independence. Recursive feedback is defined and discussed as a candidate approach to multidiscipline dynamic system simulation by numerical coupling of self-contained, single-discipline subsystem simulations. A satellite motion example containing three subsystems (orbit dynamics, attitude dynamics, and aerodynamics) has been defined and constructed using this approach. Conventional solution methods are used in the subsystem simulations. Distributed and centralized implementations of coupling have been considered. Numerical results are evaluated by direct comparison with a standard total-system, simultaneous-solution approach.

  5. Stand-alone version of the 11kW Gaia wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Bindner, H.; Rosas, P.A.C.; Teodorescu, R.; Blaabjerg, F.

    2004-09-15

    This report describes the development of a stand-alone version of the 11kW Gaia wind turbine. Various possible configurations are investigated and a configuration using a back-to-back converter is chosen. A model is developed for controller design of the fast controllers of the unit. Controllers are designed and a prototype is built for testing. The report documents the performance of the prototype through measurements done on the full scale prototype installed in a test facility where it has been tested both as a standalone unit and in parallel with a diesel genset. For system wide power quality assessment and controller design a dynamic performance assessment model has been developed. (au)

  6. Energy management system for stand-alone diesel-wind-biomass microgrid with energy storage system

    International Nuclear Information System (INIS)

    Wang, Chengshan; Liu, Yixin; Li, Xialin; Guo, Li; Qiao, Lei; Lu, Hai

    2016-01-01

    An energy management system for stand-alone microgrid composed of diesel generators, wind turbine generator, biomass generator and an ESS (energy storage system) is proposed in this paper. Different operation objectives are achieved by a hierarchical control structure with different time scales. Firstly, the optimal schedules of the diesel generators, wind turbine generator, biomass generator and ESS are determined fifteen minutes ahead according to the super short-term forecast of load and wind speed in the optimal scheduling layer. Comprehensive analysis which takes the uncertainty of load and wind speed into account is conducted in this layer to minimize the operation cost of the system and ensure a desirable range of the state of charge of the ESS. Secondly, the operation points of each unit are regulated dynamically to guarantee real-time power balance and safety range of diesel generation in the real-time control layer, based on which the response capability when suffering significant forecast deviation and other emergency issues, e.g. sudden load-up can be improved. Finally, the effectiveness of the proposed energy management strategy is verified on an RT_Lab based real-time simulation platform, and the economic performances with different types of ESS are analyzed as well. - Highlights: • A hierarchical control strategy is proposed for a stand-alone microgrid. • The uncertainties of load and wind speed have been considered. • Better economic performance and high reliability of the system can be achieved. • The influences of different energy storage systems have been analyzed.

  7. Optimal expansion planning of stand-alone systems with stochastic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Hoese, Alejandro [Instituto de Energia Electrica (IEE), Universidad Nacional de San Juan, (Argentina)

    1997-12-31

    Stand-alone systems in the range of 1 kW - 10 MW are taking relevance in the new (global) liberal concept of energy market. State and private investors are becoming increasingly attention on the use of renewable for these systems, but it must be shown that these non-conventional solutions are competitive with the established conventional ones. The high investment costs and the technical and economic uncertainties coupled with the use of time-dependent energy sources are the mainly inhibiting factors for the decision agents to choose these systems instead of conventional ones. In the paper a new model for optimal expansion planning of hybrid stand-alone generating systems under consideration of uncertainties is presented. This model is at present in {sup d}evelopment state{sup .} Results already obtained in the first steps of this research are promising and some of them are here presented. [Espanol] Los sistemas autocontenidos en el rango de 1 Kw a 10 MW estan tomando importancia en el nuevo (global) concepto liberal del mercado de la energia. Inversionistas privados y del Estado estan poniendo mayor atencion en el uso de energias renovables para estos sistemas, pero debe mostrarse que estas soluciones no-convencionales son competitivas con las convencionales establecidas. Los altos costos de inversion y las incertidumbres tecnicas y economicas aunadamente con el uso de fuentes de energia dependientes del tiempo son los principales factores inhibidores de los factores de decision para escoger estos sistemas en lugar de los convencionales. En este articulo se presenta un nuevo modelo de planeacion de expansion optima de sistemas hibridos autocontenidos de generacion electrica bajo la consideracion de incertidumbres. Este modelo esta actualmente en {sup e}stado de desarrollo{sup .} Los resultados ya obtenidos en las primeras etapas de esta investigacion son prometedores y se presentan algunos de ellos.

  8. Diagnostic value of the stand-alone synthetic image in digital breast tomosynthesis examinations.

    Science.gov (United States)

    Garayoa, Julia; Chevalier, Margarita; Castillo, Maria; Mahillo-Fernández, Ignacio; Amallal El Ouahabi, Najim; Estrada, Carmen; Tejerina, Alejandro; Benitez, Olivia; Valverde, Julio

    2018-02-01

    To demonstrate the non-inferiority of synthetic image (SI) mammography versus full-field digital mammography (FFDM) in breast tomosynthesis (DBT) examinations. An observational, retrospective, single-centre, multireader blinded study was performed, using 2384 images to directly compare SI and FFDM based on Breast Imaging Reporting and Data System (BIRADS) categorisation and visibility of radiological findings. Readers had no access to digital breast tomosynthesis slices. Multiple reader, multiple case (MRMC) receiver operating characteristic (ROC) methodology was used to compare the diagnostic performance of SI and FFDM images. The kappa statistic was used to estimate the inter-reader and intra-reader reliability. The area under the ROC curves (AUC) reveals the non-inferiority of SI versus FFDM based on BIRADS categorisation [difference between AUC (ΔAUC), -0.014] and lesion visibility (ΔAUC, -0.001) but the differences were not statistically significant (p=0.282 for BIRADS; p=0.961 for lesion visibility). On average, 77.4% of malignant lesions were detected with SI versus 76.5% with FFDM. Sensitivity and specificity of SI are superior to FFDM for malignant lesions scored as BIRADS 5 and breasts categorised as BIRADS 1. SI is not inferior to FFDM when DBT slices are not available during image reading. SI can replace FFDM, reducing the dose by 45%. • Stand-alone SI demonstrated performance not inferior for lesion visibility as compared to FFDM. • Stand-alone SI demonstrated performance not inferior for lesion BIRADS categorisation as compared to FFDM. • Synthetic images provide important dose savings in breast tomosynthesis examinations.

  9. Imagery rescripting as a stand-alone treatment for patients with social phobia: a case series.

    Science.gov (United States)

    Frets, Petra G; Kevenaar, Ciska; van der Heiden, Colin

    2014-03-01

    The majority of patients with social phobia reports experiencing negative images, usually linked to memories of earlier aversive social experiences. Several studies have indicated that such negative self-imagery appears to have a causal role in maintaining social phobia, which suggests that interventions aimed at dealing with these images could be beneficial in the treatment of social phobia. One potentially powerful approach is imagery rescripting (IR), a clinical intervention that focuses on changing the meaning and impact of unpleasant memories. In the treatment of social phobia IR was only used as part of a broader cognitive-behavioral treatment package. However, we propose that IR alone might also be an effective treatment for this anxiety disorder. The present study reports an initial evaluation of the application of IR as a stand-alone treatment for six adult outpatients presenting with social phobia. A single case series using an A-B replication across patients design was employed. Following a no-treatment baseline period, IR was delivered weekly and patients were followed up for 3 and 6 months. For all patients, substantial reductions were obtained on all outcome measures at post-treatment, and gains were largely maintained at 6-months follow-up. The generalizability of the effects of IR for social phobia is limited by the small number of patients treated by only one therapist. The results of this preliminary case series suggest that IR as a stand alone treatment is an apparently effective intervention in the treatment of patients with social phobia, and indicate that controlled evaluation of its efficacy might be worthwhile. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. A Meta-Analytic Review of Stand-Alone Interventions to Improve Body Image.

    Directory of Open Access Journals (Sweden)

    Jessica M Alleva

    Full Text Available Numerous stand-alone interventions to improve body image have been developed. The present review used meta-analysis to estimate the effectiveness of such interventions, and to identify the specific change techniques that lead to improvement in body image.The inclusion criteria were that (a the intervention was stand-alone (i.e., solely focused on improving body image, (b a control group was used, (c participants were randomly assigned to conditions, and (d at least one pretest and one posttest measure of body image was taken. Effect sizes were meta-analysed and moderator analyses were conducted. A taxonomy of 48 change techniques used in interventions targeted at body image was developed; all interventions were coded using this taxonomy.The literature search identified 62 tests of interventions (N = 3,846. Interventions produced a small-to-medium improvement in body image (d+ = 0.38, a small-to-medium reduction in beauty ideal internalisation (d+ = -0.37, and a large reduction in social comparison tendencies (d+ = -0.72. However, the effect size for body image was inflated by bias both within and across studies, and was reliable but of small magnitude once corrections for bias were applied. Effect sizes for the other outcomes were no longer reliable once corrections for bias were applied. Several features of the sample, intervention, and methodology moderated intervention effects. Twelve change techniques were associated with improvements in body image, and three techniques were contra-indicated.The findings show that interventions engender only small improvements in body image, and underline the need for large-scale, high-quality trials in this area. The review identifies effective techniques that could be deployed in future interventions.

  11. Key factors for the implementation of successful, stand-alone village electrification schemes in Peru

    Science.gov (United States)

    Sanchez-Campos, Teodoro

    The hypothesis of this work is that there are social, financial, technical, managerial institutional and political key factors that may either support or prevent the success of small stand alone energy systems in rural areas. This research work aims at contributing to the identification of such factors and study their relevance to the performance and sustainability of stand alone energy systems in rural areas; to meet its purpose, a wide range of literature was reviewed including rural electrification programmes and projects, research and development projects on access to electricity in rural areas, impact studies and others, and a field research survey was done the Andes and Upper Jungle regions in Peru. Nineteen possible critical factors were identified, thirteen with relevance at the local context (the community or village), and six with relevance at the national (or wider) context. From literature review it was found that the possible local critical factors were relevant only to four categories of factors instead of the six considered initially (i.e. social, financial, technological and managerial): the other two categories, political and institutional were found to be more relevant to the national context, therefore those were included in the group of possible critical factors of wider context. A series of questionnaires were designed to collect field data information, which was later used to analyse and establish the relation of each identified factor with the success of the systems studied. The survey research was implemented in 14 villages, 7 with small diesel sets and 7 with small hydropower schemes, all spread in the Andes and Upper Jungle of Peru, which were carefully selected to be representative of regions with isolated stand alone systems and with different socioeconomic background. Out of the 13 possible critical factors of local context, it was found that only 3 are really critical, the others are important but not critical; one of them (technical

  12. Five-year durability of stand-alone interspinous process decompression for lumbar spinal stenosis

    Directory of Open Access Journals (Sweden)

    Nunley PD

    2017-09-01

    Full Text Available Pierce D Nunley,1 Vikas V Patel,2 Douglas G Orndorff,3 William F Lavelle,4 Jon E Block,5 Fred H Geisler6 1Spine Institute of Louisiana, Shreveport, LA, 2The Spine Center, University of Colorado Hospital, Denver, CO, 3Spine Colorado, Mercy Regional Hospital, Durango, CO, 4Upstate Bone and Joint Center, East Syracuse, NY, 5Independent Consultant, San Francisco, CA, 6Independent Consultant, Chicago, IL, USA Background: Lumbar spinal stenosis is the most common indication for spine surgery in older adults. Interspinous process decompression (IPD using a stand-alone spacer that functions as an extension blocker offers a minimally invasive treatment option for intermittent neurogenic claudication associated with spinal stenosis.Methods: This study evaluated the 5-year clinical outcomes for IPD (Superion® from a randomized controlled US Food and Drug Administration (FDA noninferiority trial. Outcomes included Zurich Claudication Questionnaire (ZCQ symptom severity (ss, physical function (pf, and patient satisfaction (ps subdomains, leg and back pain visual analog scale (VAS, and Oswestry Disability Index (ODI.Results: At 5 years, 84% of patients (74 of 88 demonstrated clinical success on at least two of three ZCQ domains. Individual ZCQ domain success rates were 75% (66 of 88, 81% (71 of 88, and 90% (79 of 88 for ZCQss, ZCQpf, and ZCQps, respectively. Leg and back pain success rates were 80% (68 of 85 and 65% (55 of 85, respectively, and the success rate for ODI was 65% (57 of 88. Percentage improvements over baseline were 42%, 39%, 75%, 66%, and 58% for ZCQss, ZCQpf, leg and back pain VAS, and ODI, respectively (all P<0.001. Within-group effect sizes were classified as very large for four of five clinical outcomes (ie, >1.0; all P<0.0001. Seventy-five percent of IPD patients were free from reoperation, revision, or supplemental fixation at their index level at 5 years.Conclusion: After 5 years of follow-up, IPD with a stand-alone spacer provides

  13. Charactrization of a Li-ion battery based stand-alone a-Si photovoltaic system

    Science.gov (United States)

    Hamid Vishkasougheh, Mehdi; Tunaboylu, Bahadir

    2014-11-01

    The number of photovoltaic (PV) system installations is increasing rapidly. As more people learn about this versatile and often cost-effective power option, this trend will accelerate. This document presents a recommended design for a battery based stand-alone photovoltaic system (BSPV). BSPV system has the ability to be applied in different areas, including warning signals, lighting, refrigeration, communication, residential water pumping, remote sensing, and cathodic protection. The presented calculation method gives a proper idea for a system sizing technique. Based on application load, different scenarios are possible for designing a BSPV system. In this study, a battery based stand-alone system was designed. The electricity generation part is three a-Si panels, which are connected in parallel, and for the storage part LFP (lithium iron phosphate) battery was used. The high power LFP battery packs are 40 cells each 8S5P (configured 8 series 5 parallel). Each individual pack weighs 0.5 kg and is 25.6 V. In order to evaluate the efficiency of a-Si panels with respect to the temperature and the solar irradiation, cities of Istanbul, Ankara and Adana in Turkey were selected. Temperature and solar irradiation were gathered from reliable sources and by using translation equations, current and voltage output of panels were calculated. As a result of these calculations, current and energy outputs were computed by considering an average efficient solar irradiation time value per day in Turkey. The calculated power values were inserted to a battery cycler system, and the behavior of high power LFP batteries in a time sequence of 7.2 h was evaluated. The charging and discharging cycles were obtained and their behavior was discussed. According to the results, Istanbul has the lowest number of peak month's energy, it followed by Ankara, and ultimately Adana has the highest number of peak months and energy storage. It was observed during the tests that values up to 4 A was

  14. Multi-objective analytical model for optimal sizing of stand-alone photovoltaic water pumping systems

    International Nuclear Information System (INIS)

    Olcan, Ceyda

    2015-01-01

    Highlights: • An analytical optimal sizing model is proposed for PV water pumping systems. • The objectives are chosen as deficiency of power supply and life-cycle costs. • The crop water requirements are estimated for a citrus tree yard in Antalya. • The optimal tilt angles are calculated for fixed, seasonal and monthly changes. • The sizing results showed the validity of the proposed analytical model. - Abstract: Stand-alone photovoltaic (PV) water pumping systems effectively use solar energy for irrigation purposes in remote areas. However the random variability and unpredictability of solar energy makes difficult the penetration of PV implementations and complicate the system design. An optimal sizing of these systems proves to be essential. This paper recommends a techno-economic optimization model to determine optimally the capacity of the components of PV water pumping system using a water storage tank. The proposed model is developed regarding the reliability and cost indicators, which are the deficiency of power supply probability and life-cycle costs, respectively. The novelty is that the proposed optimization model is analytically defined for two-objectives and it is able to find a compromise solution. The sizing of a stand-alone PV water pumping system comprises a detailed analysis of crop water requirements and optimal tilt angles. Besides the necessity of long solar radiation and temperature time series, the accurate forecasts of water supply needs have to be determined. The calculation of the optimal tilt angle for yearly, seasonally and monthly frequencies results in higher system efficiency. It is, therefore, suggested to change regularly the tilt angle in order to maximize solar energy output. The proposed optimal sizing model incorporates all these improvements and can accomplish a comprehensive optimization of PV water pumping systems. A case study is conducted considering the irrigation of citrus trees yard located in Antalya, Turkey

  15. Radiographic and clinical evaluation of cage subsidence after stand-alone lateral interbody fusion.

    Science.gov (United States)

    Marchi, Luis; Abdala, Nitamar; Oliveira, Leonardo; Amaral, Rodrigo; Coutinho, Etevaldo; Pimenta, Luiz

    2013-07-01

    Indirect decompression of the neural structures through interbody distraction and fusion in the lumbar spine is feasible, but cage subsidence may limit maintenance of the initial decompression. The influence of interbody cage size on subsidence and symptoms in minimally invasive lateral interbody fusion is heretofore unreported. The authors report the rate of cage subsidence after lateral interbody fusion, examine the clinical effects, and present a subsidence classification scale. The study was performed as an institutional review board-approved prospective, nonrandomized, comparative, single-center radiographic and clinical evaluation. Stand-alone short-segment (1- or 2-level) lateral lumbar interbody fusion was investigated with 12 months of postoperative follow-up. Two groups were compared. Forty-six patients underwent treatment at 61 lumbar levels with standard interbody cages (18 mm anterior/posterior dimension), and 28 patients underwent treatment at 37 lumbar levels with wide cages (22 mm). Standing lateral radiographs were used to measure segmental lumbar lordosis, disc height, and rate of subsidence. Subsidence was classified using the following scale: Grade 0, 0%-24% loss of postoperative disc height; Grade I, 25%-49%; Grade II, 50%-74%; and Grade III, 75%-100%. Fusion status was assessed on CT scanning, and pain and disability were assessed using the visual analog scale and Oswestry Disability Index. Complications and reoperations were recorded. Pain and disability improved similarly in both groups. While significant gains in segmental lumbar lordosis and disc height were observed overall, the standard group experienced less improvement due to the higher rate of interbody graft subsidence. A difference in the rate of subsidence between the groups was evident at 6 weeks (p = 0.027), 3 months (p = 0.042), and 12 months (p = 0.047). At 12 months, 70% in the standard group and 89% in the wide group had Grade 0 or I subsidence, and 30% in the standard group

  16. Flexible Control of Small Wind Turbines With Grid Failure Detection Operating in Stand-Alone and Grid-Connected Mode

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Blaabjerg, Frede

    2004-01-01

    This paper presents the development and test of a flexible control strategy for an 11-kw wind turbine with a back-to-back power converter capable of working in both stand-alone and grid-connected mode. The stand-alone control is featured with a complex output voltage controller capable of handling...... nonlinear load and excess or deficit of generated power. Grid-connection mode with current control is also enabled for the case of isolated local grid involving other dispersed power generators such as other wind turbines or diesel generators. A novel automatic mode switch method based on a phase...

  17. Design of a reliable and low-cost stand-alone micro hydropower station

    Energy Technology Data Exchange (ETDEWEB)

    Kusakana, K.; Munda, J.L. [Tshwane Univ. of Technology, Pretoria (South Africa)

    2008-07-01

    A stand-alone micro-hydropower station was presented. The plant was comprised of a squirrel cage induction machine coupled to a Kaplan water turbine. Power converters were used to control the variable frequency and voltage outputs of the generator caused by variations in water flow. The hydropower plant was installed a farm in the Kwazulu-Natal region of South Africa, and was designed to provide electricity in relation to the low power demand of users in the region as well as according to the site's hydrology and topology. Load forecasts for the 8 houses using the system were conducted. A generator with a higher output than the average power needed to feed the load was selected in order to ensure load supply during peak demand. The system was designed to shore energy generated during off-peak periods in batteries. An AC-DC-AC converter was used as an interface between the generator and the load in order to ensure voltage and frequency stabilization. Simulations of plant components were conducted to demonstrate output power supply during water flow variations. Results of the modelling study indicated that power converters are needed to stabilize generator outputs. The hydropower design is a cost-effective means of supplying power to low-income households. 10 refs., 2 tabs., 7 figs.

  18. Solar photovoltaic applications seminar: design, installation and operation of small, stand-alone photovoltaic power systems

    Energy Technology Data Exchange (ETDEWEB)

    1980-07-01

    This seminar material was developed primarily to provide solar photovoltaic (PV) applied engineering technology to the Federal community. An introduction to photoconductivity, semiconductors, and solar photovoltaic cells is included along with a demonstration of specific applications and application identification. The seminar details general systems design and incorporates most known information from industry, academia, and Government concerning small solar cell power system design engineering, presented in a practical and applied manner. Solar PV power system applications involve classical direct electrical energy conversion and electric power system analysis and synthesis. Presentations and examples involve a variety of disciplines including structural analysis, electric power and load analysis, reliability, sizing and optimization; and, installation, operation and maintenance. Four specific system designs are demonstrated: water pumping, domestic uses, navigational and aircraft aids, and telecommunications. All of the applications discussed are for small power requirement (under 2 kilowatts), stand-alone systems to be used in remote locations. Also presented are practical lessons gained from currently installed and operating systems, problems at sites and their resolution, a logical progression through each major phase of system acquisition, as well as thorough design reviews for each application.

  19. Stand-alone excitation synchronous wind power generators with power flow management strategy

    Directory of Open Access Journals (Sweden)

    Tzuen-Lih Chern

    2014-09-01

    Full Text Available This study presents a stand-alone excitation synchronous wind power generator (SESWPG with power flow management strategy (PFMS. The rotor speed of the excitation synchronous generator tracks the utility grid frequency by using servo motor tracking technologies. The automatic voltage regulator governs the exciting current of generator to achieve the control goals of stable voltage. When wind power is less than the needs of the consumptive loading, the proposed PFMS increases motor torque to provide a positive power output for the loads, while keeping the generator speed constant. Conversely, during the periods of wind power greater than output loads, the redundant power of generator production is charged to the battery pack and the motor speed remains constant with very low power consumption. The advantage of the proposed SESWPG is that the generator can directly output stable alternating current (AC electricity without using additional DC–AC converters. The operation principles with software simulation for the system are described in detail. Experimental results of a laboratory prototype are shown to verify the feasibility of the system.

  20. Simulation of stand alone PV system; Dokuritsugata taiyoko hatsuden system no simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, H.; Ogawa, H.; Sekii, Y. [Chiba Institute of Technology, Chiba (Japan); Tsuda, I.; Nozaki, K. [Electrotechnical Laboratory, Tsukuba (Japan); Kurokawa, K. [Tokyo University of Agriculture and Technology, Tokyo (Japan)

    1996-10-27

    In order to evaluate the simulation results of a photovoltaic power generation system, an operation simulation was carried out using the actual measured data of a stand alone PV system in Miyakojima, Okinawa Prefecture, so as to make a comparison with the actual operation data. The electric power was supplied to 250 houses and primary/junior high schools in the surrounding villages, which had an average demand load of approximately 90kw and the maximum of approximately 200kw. The power was supplied through the PV power generation in the duration of the sunshine, with an excess power charged in storage batteries and then supplied from the batteries at night. The array capacity was made 750kWp, the output current and storage batteries being characteristic type with an actual efficiency curve used for the inverter. The weather data used were the actual inclined insolation quantity and the outside air temperature data for a period of one month of November. The power charged in excess of 100% in the batteries was termed as an overflow power. With the charging condition 30% or less, a diesel generator was run for a rated operation for one hour, the power of which was termed as a backup power. As a result, the simulation was found nearly in agreement with the actual measurements. 5 refs., 7 figs., 2 tabs.

  1. Control of a Stand-Alone Variable Speed Wind Energy Supply System †

    Directory of Open Access Journals (Sweden)

    Mohamed M. Hamada

    2013-04-01

    Full Text Available This paper presents a simple control strategy for the operation of a variable speed stand-alone wind turbine with a permanent magnet synchronous generator (PMSG. The PMSG is connected to a three phase resistive load through a switch mode rectifier and a voltage source inverter. Control of the generator side converter is used to achieve maximum power extraction from the available wind power. Control of the DC-DC bidirectional buck-boost converter, which is connected between batteries bank and DC-link voltage, is used to maintain the DC-link voltage at a constant value. It is also used to make the batteries bank stores the surplus of wind energy and supplies this energy to the load during a wind power shortage. The load side voltage source inverter uses a relatively complex vector control scheme to control the output load voltage in terms of amplitude and frequency. The control strategy works under wind speed variation as well as with variable load. Extensive simulation results have been performed using MATLAB/SIMULINK.

  2. Can aqueous hydrogen peroxide be used as a stand-alone energy source?

    International Nuclear Information System (INIS)

    Disselkamp, Robert S.

    2010-01-01

    A novel electrochemical scheme to convert a stand-alone supply of aqueous hydrogen peroxide into a fuel cell-ready stream of hydrogen gas plus aqueous hydrogen peroxide is described. The electrochemical cell, consisting of a solid base and solid acid electrocatalyst, together with a proton exchange membrane, comprise the system that converts aqueous hydrogen peroxide into separate gas streams of oxygen and hydrogen. Aqueous hydrogen peroxide is contained in the anode compartment only and exists in the region where oxygen gas is formed, whereas the cathode compartment is where hydrogen gas is generated and therefore exists in a reduced state. A near zero theoretical over-potential can be achieved by the choice of basicity and acidity of the electrode materials. The primary cost of the electrochemical cell is electrode construction and the aqueous hydrogen peroxide energy storage compound. Additional research effort is required to experimentally validate the concept and explore the full economic impact should initial studies, based on the design presented here, prove promising. (author)

  3. Comparative analysis of distributed MPPT controllers for partially shaded stand alone photovoltaic systems

    International Nuclear Information System (INIS)

    Muthuramalingam, M.; Manoharan, P.S.

    2014-01-01

    Highlights: • Analyzes the performance of ANN and ANFIS MPPT algorithms by stand alone PV system. • ISSBC with ANFIS can provide the overall efficiency higher than ANN. • CHBMLI integrate with SHE ANN modulation technique improve output voltage quality. • Simulation and hardware results show the ANFIS algorithm efficient than ANN algorithm. - Abstract: This paper presents a unique combination of an interleaved soft switched boost converter (ISSBC) run by a set of two photovoltaic panel (PV) with a distributed MPPT, suitable to guarantee MPPT even under partial shadowed conditions, managed by an adaptive neuro fuzzy inference system trained by the training data derived from a particle swarm optimization (PSO–ANFIS) unit. The ISSBC is followed by a, single phase cascaded H bridge five-level inverter (CHI) driven by the individual DC outputs of the ISSBC, with selective harmonic elimination scheme to eliminate typically the seventh order harmonics. A comparison of different intelligent distributed maximum power point tracking (MPPT) algorithms for photovoltaic (PV) system under partial shadow conditions is carried out. The use of the ISSBC guarantees mitigation of ripple and it is meant to handle higher currents with minimal switching losses. Simulation was carried out in the Matlab Simulink environment and an experimental verification with a scaled down model validated the proposed scheme. It has been thus established, by both simulation and experimental verification, that the PSO–ANFIS model of distributed MPPT scheme of control outperforms other schemes of control for MPPT

  4. Battery Storage Technologies for Electrical Applications: Impact in Stand-Alone Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Daniel Akinyele

    2017-11-01

    Full Text Available Batteries are promising storage technologies for stationary applications because of their maturity, and the ease with which they are designed and installed compared to other technologies. However, they pose threats to the environment and human health. Several studies have discussed the various battery technologies and applications, but evaluating the environmental impact of batteries in electrical systems remains a gap that requires concerted research efforts. This study first presents an overview of batteries and compares their technical properties such as the cycle life, power and energy densities, efficiencies and the costs. It proposes an optimal battery technology sizing and selection strategy, and then assesses the environmental impact of batteries in a typical renewable energy application by using a stand-alone photovoltaic (PV system as a case study. The greenhouse gas (GHG impact of the batteries is evaluated based on the life cycle emission rate parameter. Results reveal that the battery has a significant impact in the energy system, with a GHG impact of about 36–68% in a 1.5 kW PV system for different locations. The paper discusses new batteries, strategies to minimize battery impact and provides insights into the selection of batteries with improved cycling capacity, higher lifespan and lower cost that can achieve lower environmental impacts for future applications.

  5. Approaches for developing a sizing method for stand-alone PV systems with variable demand

    Energy Technology Data Exchange (ETDEWEB)

    Posadillo, R. [Grupo de Investigacion en Energias y Recursos Renovables, Dpto. de Fisica Aplicada, E.P.S., Universidad de Cordoba, Avda. Menendez Pidal s/n, 14004 Cordoba (Spain); Lopez Luque, R. [Grupo de Investigacion de Fisica para las Energias y Recursos Renovables, Dpto. de Fisica Aplicada. Edificio C2 Campus de Rabanales, 14071 Cordoba (Spain)

    2008-05-15

    Accurate sizing is one of the most important aspects to take into consideration when designing a stand-alone photovoltaic system (SAPV). Various methods, which differ in terms of their simplicity or reliability, have been developed for this purpose. Analytical methods, which seek functional relationships between variables of interest to the sizing problem, are one of these approaches. A series of rational considerations are presented in this paper with the aim of shedding light upon the basic principles and results of various sizing methods proposed by different authors. These considerations set the basis for a new analytical method that has been designed for systems with variable monthly energy demands. Following previous approaches, the method proposed is based on the concept of loss of load probability (LLP) - a parameter that is used to characterize system design. The method includes information on the standard deviation of loss of load probability ({sigma}{sub LLP}) and on two new parameters: annual number of system failures (f) and standard deviation of annual number of failures ({sigma}{sub f}). The method proves useful for sizing a PV system in a reliable manner and serves to explain the discrepancies found in the research on systems with LLP<10{sup -2}. We demonstrate that reliability depends not only on the sizing variables and on the distribution function of solar radiation, but on the minimum value as well, which in a given location and with a monthly average clearness index, achieves total solar radiation on the receiver surface. (author)

  6. On the economics of stand-alone renewable hybrid power plants in remote regions

    International Nuclear Information System (INIS)

    Petrakopoulou, Fontina

    2016-01-01

    Highlights: • Economic evaluation of three renewable hybrid power plants for off-grid operation. • The high electricity cost of remote regions increases the competitiveness of renewable energy. • The proposed plants are economically viable when compared to the existing situation. • The zero direct emissions of the plants constitute an additional advantage of the plants. - Abstract: In recent years ever more examples of regions that have managed to achieve or orientate themselves toward renewable energy sufficiency are emerging. However, actions to create energy autonomy are mainly the result of isolated activities and they are less driven from fully organized movements. In addition, total energy independence without the support of a centralized electrical grid is yet to be achieved. The objectives of this work are to investigate the associated costs of stand-alone renewable hybrid power plants on a Greek island and compare them to the cost of the currently used fossil-fuel-based conventional plant. The plants examined here are designed to fully cover the electricity needs of the island. Islands may face numerous energy problems and rely heavily on foreign and environmentally-harmful fuels. It is shown that the relatively high cost of electricity of such a remote region can increase the competitiveness and promote the wider incorporation of technologies based on renewable energy sources that may, in other cases, seem economically inferior to business-as-usual energy solutions.

  7. Use of Super-Capacitor to Enhance Charging Performance of Stand-Alone Solar PV System

    KAUST Repository

    Huang, B. J.

    2011-01-01

    Introduction: The battery charging performance in a stand-alone solar PV system affects the PV system efficiency and the load operating time. The New Energy Center of National Taiwan University has been devoted to the development of a PWM charging technique to continue charging the lead-acid battery after the overcharge point to increase the battery storage capacity by more than 10%. The present study intends to use the super-capacitor to further increase the charge capacity before the overcharge point of the battery. The super-capacitor is connected in parallel to the lead-acid battery. This will reduce the overall charging impedance during the charge and increase the charging current, especially in sunny weather. A system dynamics model of the lead-acid battery and super-capacitor was derived and the control system simulation was carried out to predict the charging performance for various weathers. It shows that the overall battery impedance decreases and charging power increases with increasing solar radiation. An outdoor comparative test for two identical PV systems with and without supercapacitor was carried out. The use of super-capacitor is shown to be able to increase the lead-acid charging capacity by more than 25% at sunny weather and 10% in cloudy weather. © Springer-Verlag Berlin Heidelberg 2011.

  8. Motion Sensorless Bidirectional PWM Converter Control with Seamless Switching from Power Grid to Stand Alone and Back

    DEFF Research Database (Denmark)

    Fatu, Marius; Tutelea, Lucian; Teodorescu, Remus

    2007-01-01

    This paper presents concepts and tests results on a flexible sensorless control strategy for a PMSG driven by a small wind turbine with back-to-back power converters capable to function in both stand alone and grid connection mode. A new automatic seamless transfer method, based on phase-locked...

  9. Analyzing grid extension and stand-alone photovoltaic systems for the cost-effective electrification of Kenya

    NARCIS (Netherlands)

    Zeyringer, Marianne; Pachauri, Shonali; Schmid, Erwin; Schmidt, Johannes; Worrell, Ernst; Morawetz, Ulrich B.

    2015-01-01

    The declaration of 2014-2024 as the Decade of Sustainable Energy for All has catalyzed actions towards achieving universal electricity access. The high costs of building electric infrastructure are a major impediment to improved access, making stand-alone photovoltaic (PV) systems an attractive

  10. Stand-Alone Ethics, Social Responsibility, and Sustainability Course Requirements: A Snapshot from Australia and New Zealand

    Science.gov (United States)

    Rundle-Thiele, Sharyn R.; Wymer, Walter

    2010-01-01

    This article analyzes the extent to which Australian and New Zealand marketing educators use dedicated or stand-alone courses to equip students with alternative views of business. A census of marketing programs in degree-granting universities was conducted. Program brochures were obtained via the Internet and were content analyzed. This study…

  11. 49 CFR 1109.4 - Mandatory mediation in rate cases to be considered under the stand-alone cost methodology.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Mandatory mediation in rate cases to be considered... § 1109.4 Mandatory mediation in rate cases to be considered under the stand-alone cost methodology. (a) A... methodology must engage in non-binding mediation of its dispute with the railroad upon filing a formal...

  12. An improved synchronous reference frame phase-locked loop for stand-alone variable speed constant frequency power generation systems

    DEFF Research Database (Denmark)

    Liu, Yi; Xu, Wei; Ke, Longzhang

    2017-01-01

    The phase-locked loop (PLL) based on conventional synchronous reference frame, i.e. dqPLL, is usually employed in grid-connected variable speed constant frequency (VSCF) power generation systems (PGSs). However, the voltage amplitude drop of stand-alone PGSs is often greater than that of the grid...

  13. The eBioKit, a stand-alone educational platform for bioinformatics.

    Science.gov (United States)

    Hernández-de-Diego, Rafael; de Villiers, Etienne P; Klingström, Tomas; Gourlé, Hadrien; Conesa, Ana; Bongcam-Rudloff, Erik

    2017-09-01

    Bioinformatics skills have become essential for many research areas; however, the availability of qualified researchers is usually lower than the demand and training to increase the number of able bioinformaticians is an important task for the bioinformatics community. When conducting training or hands-on tutorials, the lack of control over the analysis tools and repositories often results in undesirable situations during training, as unavailable online tools or version conflicts may delay, complicate, or even prevent the successful completion of a training event. The eBioKit is a stand-alone educational platform that hosts numerous tools and databases for bioinformatics research and allows training to take place in a controlled environment. A key advantage of the eBioKit over other existing teaching solutions is that all the required software and databases are locally installed on the system, significantly reducing the dependence on the internet. Furthermore, the architecture of the eBioKit has demonstrated itself to be an excellent balance between portability and performance, not only making the eBioKit an exceptional educational tool but also providing small research groups with a platform to incorporate bioinformatics analysis in their research. As a result, the eBioKit has formed an integral part of training and research performed by a wide variety of universities and organizations such as the Pan African Bioinformatics Network (H3ABioNet) as part of the initiative Human Heredity and Health in Africa (H3Africa), the Southern Africa Network for Biosciences (SAnBio) initiative, the Biosciences eastern and central Africa (BecA) hub, and the International Glossina Genome Initiative.

  14. Hydrogen-based energy storage unit for stand alone PV systems

    International Nuclear Information System (INIS)

    Labbe, J.

    2006-12-01

    Stand alone systems supplied only by a photovoltaic generator need an energy storage unit to be fully self sufficient. Lead acid batteries are commonly used to store energy because of their low cost, despite several operational constraints. A hydrogen-based energy storage unit (HESU) could be another candidate, including an electrolyser, a fuel cell and a hydrogen tank. However many efforts still need to be carried out for this technology to reach an industrial stage. In particular, market outlets must be clearly identified. The study of small stationary applications (few kW) is performed by numerical simulations. A simulator is developed in the Matlab/Simulink environment. It is mainly composed of a photovoltaic field and a storage unit (lead acid batteries, HESU, or hybrid storage HESU/batteries). The system component sizing is achieved in order to ensure the complete system autonomy over a whole year of operation. The simulator is tested with 160 load profiles (1 kW as a yearly mean value) and three locations (Algeria, France and Norway). Two coefficients are set in order to quantify the correlation between the power consumption of the end user and the renewable resource availability at both daily and yearly scales. Among the tested cases, a limit value of the yearly correlation coefficient came out, enabling to recommend the use of the most adapted storage to a considered case. There are cases for which using HESU instead of lead acid batteries can increase the system efficiency, decrease the size of the photovoltaic field and improve the exploitation of the renewable resource. In addition, hybridization of HESU with batteries always leads to system enhancements regarding its sizing and performance, with an efficiency increase by 10 to 40 % depending on the considered location. The good agreement between the simulation data and field data gathered on real systems enabled the validation of the models used in this study. (author)

  15. Stand-alone rolling circle amplification combined with capillary electrophoresis for specific detection of small RNA.

    Science.gov (United States)

    Li, Ni; Jablonowski, Carolyn; Jin, Hailing; Zhong, Wenwan

    2009-06-15

    Noncoding small RNAs play diverse, important biological roles through gene expression regulation. However, their low expression levels make it difficult to identify new small RNA species and study their functions, calling for the development of detection schemes with higher simplicity, sensitivity, and specificity. Herein, we reported a straightforward assay that combined the stand-alone rolling circle amplification (RCA) with capillary electrophoresis (CE) for specific and sensitive detection of small RNAs in biological samples. In order to enhance the overall reaction efficiency and simplify the procedure, RCA was not preceded with ligation, and a preformed circular probe was employed as the template for the target small RNA-primed isothermal amplification. The long RCA product was digested and analyzed by CE. Two DNA polymerases, the Phi29 and Bst, were compared for their detection performance. Bst is superior in the aspects of specificity, procedure simplicity, and reproducibility, while Phi29 leads to a 5-fold lower detection limit and is able to detect as low as 35 amol of the target small RNA. Coamplification of an internal standard with the target and employment of the RNase A digestion step allow accurate and reproducible quantification of low amounts of small RNA targets spiked into hundreds of nanograms of the plant total RNA extract with a recovery below 110% using either enzyme. Our assay can be adapted to a capillary array system for high-throughput screening of small RNA expression in biological samples. Also, the one-step isothermal process has the potential to conveniently amplify a very limited amount of the RNA samples, e.g., RNA extracted from only a few cells, inside the capillary column or on a microchip.

  16. Radiologic Assessment of Subsidence in Stand-Alone Cervical Polyetheretherketone (PEEK) Cage.

    Science.gov (United States)

    Ha, Sung-Kon; Park, Jung-Yul; Kim, Se-Hoon; Lim, Dong-Jun; Kim, Sang-Dae; Lee, Sang-Kook

    2008-12-01

    Aim of study was to find a proper method for assessing subsidence using a radiologic measurement following anterior cervical discectomy and fusion (ACDF) with stand-alone polyetheretherketone (PEEK), Solistrade mark cage. Forty-two patients who underwent ACDF with Solistrade mark cage were selected. With a minimum follow-up of 6 months, the retrospective investigation was conducted for 37 levels in 32 patients. Mean follow-up period was 18.9 months. Total intervertebral height (TIH) of two fused vertebral bodies was measured on digital radiographs with built-in software. Degree of subsidence (DeltaTIH) was reflected by the difference between the immediate postoperative and follow-up TIH. Change of postoperative disc space height (CT-MRDeltaTIH) was reflected by the difference between TIH of the preoperative mid-sagittal 2D CT and that of the preoperative mid-sagittal T1-weighted MRI. Compared to preoperative findings, postoperative disc height was increased in all cases and subsidence was observed only in 3 cases. For comparison of subsidence and non-subsidence group, TIH and CT-MRDeltaTIH of each group were analyzed. There was no statistically significant difference in TIH and CT-MRDeltaTIH between each group at 4 and 8 weeks, but a difference was observed at the last follow-up TIH (p=0.0497). ACDF with Solistrade mark cage was associated with relatively good radiologic long-term results. Fusion was achieved in 94.5% and subsidence occurred in 8.1% by the radiologic assessment. Statistical analysis reveals that the subsidence seen later than 8 weeks after surgery and the development of subsidence does not correlate statistically with the change of the postoperative disc space height.

  17. Stand-Alone Lateral Interbody Fusion for the Treatment of Low-Grade Degenerative Spondylolisthesis

    Directory of Open Access Journals (Sweden)

    Luis Marchi

    2012-01-01

    Full Text Available The purpose of this paper was to investigate the stand-alone lateral interbody fusion as a minimally invasive option for the treatment of low-grade degenerative spondylolisthesis with a minimum 24-month followup. Prospective nonrandomized observational single-center study. 52 consecutive patients (67.6±10 y/o; 73.1% female; 27.4±3.4 BMI with single-level grade I/II single-level degenerative spondylolisthesis without significant spine instability were included. Fusion procedures were performed as retroperitoneal lateral transpsoas interbody fusions without screw supplementation. The procedures were performed in average 73.2 minutes and with less than 50cc blood loss. VAS and Oswestry scores showed lasting improvements in clinical outcomes (60% and 54.5% change, resp.. The vertebral slippage was reduced in 90.4% of cases from mean values of 15.1% preoperatively to 7.4% at 6-week followup (P<0.001 and was maintained through 24 months (7.1%, P<0.001. Segmental lordosis (P<0.001 and disc height (P<0.001 were improved in postop evaluations. Cage subsidence occurred in 9/52 cases (17% and 7/52 cases (13% spine levels needed revision surgery. At the 24-month evaluation, solid fusion was observed in 86.5% of the levels treated. The minimally invasive lateral approach has been shown to be a safe and reproducible technique to treat low-grade degenerative spondylolisthesis.

  18. "Candidatus Fokinia solitaria", a Novel "Stand-Alone" Symbiotic Lineage of Midichloriaceae (Rickettsiales.

    Directory of Open Access Journals (Sweden)

    Franziska Szokoli

    Full Text Available Recently, the family Midichloriaceae has been described within the bacterial order Rickettsiales. It includes a variety of bacterial endosymbionts detected in different metazoan host species belonging to Placozoa, Cnidaria, Arthropoda and Vertebrata. Representatives of Midichloriaceae are also considered possible etiological agents of certain animal diseases. Midichloriaceae have been found also in protists like ciliates and amoebae. The present work describes a new bacterial endosymbiont, "Candidatus Fokinia solitaria", retrieved from three different strains of a novel Paramecium species isolated from a wastewater treatment plant in Rio de Janeiro (Brazil. Symbionts were characterized through the full-cycle rRNA approach: SSU rRNA gene sequencing and fluorescence in situ hybridization (FISH with three species-specific oligonucleotide probes. In electron micrographs, the tiny rod-shaped endosymbionts (1.2 x 0.25-0.35 μm in size were not surrounded by a symbiontophorous vacuole and were located in the peripheral host cytoplasm, stratified in the host cortex in between the trichocysts or just below them. Frequently, they occurred inside autolysosomes. Phylogenetic analyses of Midichloriaceae apparently show different evolutionary pathways within the family. Some genera, such as "Ca. Midichloria" and "Ca. Lariskella", have been retrieved frequently and independently in different hosts and environmental surveys. On the contrary, others, such as Lyticum, "Ca. Anadelfobacter", "Ca. Defluviella" and the presently described "Ca. Fokinia solitaria", have been found only occasionally and associated to specific host species. These last are the only representatives in their own branches thus far. Present data do not allow to infer whether these genera, which we named "stand-alone lineages", are an indication of poorly sampled organisms, thus underrepresented in GenBank, or represent fast evolving, highly adapted evolutionary lineages.

  19. Optimum capacity determination of stand-alone hybrid generation system considering cost and reliability

    International Nuclear Information System (INIS)

    Chen, Hung-Cheng

    2013-01-01

    Highlights: ► This paper presents a methodology for the installation capacity optimization. ► Hybrid generation system is optimized by application of adaptive genetic algorithm. ► A cost investigation is made under various conditions and component characteristics. ► The optimization scheme is validated to meet the annual power load demand. -- Abstract: The aim of this work is to present an optimization methodology for the installation capacity of a stand-alone hybrid generation system, taking into consideration the cost and reliability. Firstly, on the basis of derived steady state models of a wind generator (WG), a photovoltaic array (PV), a battery and an inverter, the hybrid generation system is modeled for the purpose of capacity optimization. Secondly, the power system is analyzed for determining both the system structure and the operation control strategy. Thirdly, according to hourly weather database of wind speed, temperature and solar irradiation, annual power generation capacity is estimated for the system match design in order that an annual power load demand can be met. The capacity determination of a hybrid generation system becomes complicated as a result of the uncertainty in the renewable energy together with load demand and the nonlinearity of system components. Aimed at the power system reliability and the cost minimization, the capacity of a hybrid generation system is optimized by application of an adaptive genetic algorithm (AGA) to individual power generation units. A total cost investigation is made under various conditions, such as wind generator power curves, battery discharge depth and the loss of load probability (LOLP). At the end of this work, the capacity of a hybrid generation system is optimized at two installation sites, namely the offshore Orchid Island and Wuchi in Taiwan. The optimization scheme is validated to optimize power capacities of a photovoltaic array, a battery and a wind turbine generator with a relative

  20. A Low-Power Wearable Stand-Alone Tongue Drive System for People With Severe Disabilities.

    Science.gov (United States)

    Jafari, Ali; Buswell, Nathanael; Ghovanloo, Maysam; Mohsenin, Tinoosh

    2018-02-01

    This paper presents a low-power stand-alone tongue drive system (sTDS) used for individuals with severe disabilities to potentially control their environment such as computer, smartphone, and wheelchair using their voluntary tongue movements. A low-power local processor is proposed, which can perform signal processing to convert raw magnetic sensor signals to user-defined commands, on the sTDS wearable headset, rather than sending all raw data out to a PC or smartphone. The proposed sTDS significantly reduces the transmitter power consumption and subsequently increases the battery life. Assuming the sTDS user issues one command every 20 ms, the proposed local processor reduces the data volume that needs to be wirelessly transmitted by a factor of 64, from 9.6 to 0.15 kb/s. The proposed processor consists of three main blocks: serial peripheral interface bus for receiving raw data from magnetic sensors, external magnetic interference attenuation to attenuate external magnetic field from the raw magnetic signal, and a machine learning classifier for command detection. A proof-of-concept prototype sTDS has been implemented with a low-power IGLOO-nano field programmable gate array (FPGA), bluetooth low energy, battery and magnetic sensors on a headset, and tested. At clock frequency of 20 MHz, the processor takes 6.6 s and consumes 27 nJ for detecting a command with a detection accuracy of 96.9%. To further reduce power consumption, an application-specified integrated circuit processor for the sTDS is implemented at the postlayout level in 65-nm CMOS technology with 1-V power supply, and it consumes 0.43 mW, which is 10 lower than FPGA power consumption and occupies an area of only 0.016 mm.

  1. Stand-Alone Photovoltaic System Assessment in Warmer Urban Areas in Mexico

    Directory of Open Access Journals (Sweden)

    Alberto-Jesus Perea-Moreno

    2018-01-01

    Full Text Available The aim of this study is to examine the possibility of using a stand-alone photovoltaic system (SAPVS for electricity generation in urban areas in Southern Mexico. In Mexico, an urban area is defined as an area where more than 2500 inhabitants live. Due to constant migration from the countryside to the cities, the number of inhabitants of urban localities has been increasing. Global horizontal irradiation (GHI data were recorded every 10 min during 2014–2016 in Coatzacoalcos in the state of Veracruz located on 18°08′09″ N and 94°27′48″ W. In this study, batteries represented 77% of the total cost, 12 PV panels of 310 W could export 5.41 MWh to the grid, and an inverter with an integrated controller and charger was selected, which decreased the initial cost. The city of Coatzacoalcos was chosen because the average annual temperature is 28°, with an average relative humidity of 75% and an average irradiance of 5.3 kWh/m2/day. An emission factor 0.505 tCO2/MWh of greenhouse gases (GHG were obtained, based on the power system, the reduction of net annual GHG would be 11 tCO2 and a financial revenue of 36.951 × 103 $/tCO2 would be obtained. Financial parameters such as a 36.3% Internal Rate Return (IRR and 3.4 years payback show the financial viability of this investment. SAPVSs in urban areas in Mexico could be a benefit as long as housing has a high consumption of electricity.

  2. Brackish water desalination by a stand alone reverse osmosis desalination unit powered by photovoltaic solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Hrayshat, Eyad S. [Tafila Technical University, P.O. Box 66, Tafila 66110 (Jordan)

    2008-08-15

    Desalination of brackish water as a viable option to cope with water scarcity and to overcome water deficit in Jordan is assessed. A stand alone reverse osmosis (RO) desalination unit powered by photovoltaic (PV) solar energy is proposed, and a computer code in C++ was generated in order to simulate the process, and to predict the water production at 10 selected sites based on the available solar radiation data, sunshine hours and salinity of the feed water (TDS of 3000, 5000, 7000, and 10,000 mg/L). It was found that most of the selected sites showed favorable application of the proposed system in Jordan. Tafila, Queira, Ras Muneef, H-4, and H-5 are the most favorable sites. With TDS of 7000 mg/L, the highest annual water production of 1679 m{sup 3}/year was observed in Tafila, followed by Queira with production of 1473 m{sup 3}/year. Ras Muneef, H-4, and H-5 showed close to each other production of 1363, 1345, and 1340 m{sup 3}/year, respectively. Among the most favorable sites (Tafila, Queira, Ras Muneef, H-4, and H-5), Ras Muneef was found to be the best site in terms of the daily amount of water produced during the driest months of the year (May-September). Its production during these months forms about 65% of its total daily water production during a 1-year cycle, while for each of the other most favorable sites namely Tafila, Queira, H-4, and H-5, a 61% of production was observed during the same period. (author)

  3. Stand-Alone Solar Organic Rankine Cycle Water Pumping System and Its Economic Viability in Nepal

    Directory of Open Access Journals (Sweden)

    Suresh Baral

    2015-12-01

    Full Text Available The current study presents the concept of a stand-alone solar organic Rankine cycle (ORC water pumping system for rural Nepalese areas. Experimental results for this technology are presented based on a prototype. The economic viability of the system was assessed based on solar radiation data of different Nepalese geographic locations. The mechanical power produced by the solar ORC is coupled with a water pumping system for various applications, such as drinking and irrigation. The thermal efficiency of the system was found to be 8% with an operating temperature of 120 °C. The hot water produced by the unit has a temperature of 40 °C. Economic assessment was done for 1-kW and 5-kW solar ORC water pumping systems. These systems use different types of solar collectors: a parabolic trough collector (PTC and an evacuated tube collector (ETC. The economic analysis showed that the costs of water are $2.47/m3 (highest and $1.86/m3 (lowest for the 1-kW system and a 150-m pumping head. In addition, the cost of water is reduced when the size of the system is increased and the pumping head is reduced. The minimum volumes of water pumped are 2190 m3 and 11,100 m3 yearly for 1 kW and 5 kW, respectively. The payback period is eight years with a profitability index of 1.6. The system is highly feasible and promising in the context of Nepal.

  4. Feasibility study and energy conversion analysis of stand-alone hybrid renewable energy system

    International Nuclear Information System (INIS)

    Baghdadi, Fazia; Mohammedi, Kamal; Diaf, Said; Behar, Omar

    2015-01-01

    Highlights: • Hybrid stand-alone wind–solar–fossil power system is analyzed. • Measurement data are used to evaluate system performance. • The proposed system can generate about 70% from renewables. • Such a hybrid plant is very promising for remote regions in Algeria. - Abstract: There is a great interest in the development of renewable power technologies in Algeria, and more particularly hybrid concept. The present paper has investigated the performance of hybrid PV–Wind–Diesel–Battery configuration based on hourly measurements of Adrar climate (southern Algeria). Data of global solar radiation, ambient temperature and wind speed for a period of one year have been used. Firstly, the proposed hybrid system has been optimized by means of HOMER software. The optimization process has been carried out taking into account renewable resources potential and energy demand; while maximizing renewable electricity use and fuel saving are the purpose. In the second step, a mathematical model has been developed to ensure efficient energy management on the basis of various operation strategies. The analysis has shown that renewable energy system (PV–Wind) is able to supply about 70% of the demand. Wind power has ranked first with 43% of the annual total electricity production followed by diesel generator (with 31%) while the remaining fraction is being to PV panels. In this context, 69% of the fossil fuel can be saved when using the proposed hybrid configuration instead of the diesel generators that are currently installed in most remote regions in Algeria. Such a concept is very promising to meet the focus of renewable energy program announced in 2011.

  5. Probabilistic modelling and analysis of stand-alone hybrid power systems

    International Nuclear Information System (INIS)

    Lujano-Rojas, Juan M.; Dufo-López, Rodolfo; Bernal-Agustín, José L.

    2013-01-01

    As a part of the Hybrid Intelligent Algorithm, a model based on an ANN (artificial neural network) has been proposed in this paper to represent hybrid system behaviour considering the uncertainty related to wind speed and solar radiation, battery bank lifetime, and fuel prices. The Hybrid Intelligent Algorithm suggests a combination of probabilistic analysis based on a Monte Carlo simulation approach and artificial neural network training embedded in a genetic algorithm optimisation model. The installation of a typical hybrid system was analysed. Probabilistic analysis was used to generate an input–output dataset of 519 samples that was later used to train the ANNs to reduce the computational effort required. The generalisation ability of the ANNs was measured in terms of RMSE (Root Mean Square Error), MBE (Mean Bias Error), MAE (Mean Absolute Error), and R-squared estimators using another data group of 200 samples. The results obtained from the estimation of the expected energy not supplied, the probability of a determined reliability level, and the estimation of expected value of net present cost show that the presented model is able to represent the main characteristics of a typical hybrid power system under uncertain operating conditions. - Highlights: • This paper presents a probabilistic model for stand-alone hybrid power system. • The model considers the main sources of uncertainty related to renewable resources. • The Hybrid Intelligent Algorithm has been applied to represent hybrid system behaviour. • The installation of a typical hybrid system was analysed. • The results obtained from the study case validate the presented model

  6. A stand-alone demography and landscape structure module for Earth system models

    Science.gov (United States)

    Nieradzik, L. P.; Haverd, V.; Smith, B.; Cook, G. D.; Briggs, P.; Roxburgh, S.; Liedloff, A.; Meyer, C.; Canadell, J.

    2013-12-01

    component of any LSM, represents a significant advance in our ability to use in-situ and remotely sensed observations of biomass and individual level parameters (e.g. crown-size, tree-height, stem diameter) as constraints on the terrestrial carbon cycle. Haverd, V., B. Smith, G. Cook, P. Briggs, L. Nieradzik, S. Roxburgh, A. Liedloff, C. Meyer, and J. G. Canadell, A stand-alone tree demography and landscape structure module for Earth system models, submitted to Geophys. Res. Let., 2013 Wolf, A., P. Ciais, V. Bellassen, N. Delbart, C.B. Field, and J.A. Berry, Forest biomass allometry in global land surface models, Global Biogeochem. Cycles, 25, GB3015, doi:10.1029/2010GB003917, 2011

  7. prfectBLAST: a platform-independent portable front end for the command terminal BLAST+ stand-alone suite.

    Science.gov (United States)

    Santiago-Sotelo, Perfecto; Ramirez-Prado, Jorge Humberto

    2012-11-01

    prfectBLAST is a multiplatform graphical user interface (GUI) for the stand-alone BLAST+ suite of applications. It allows researchers to do nucleotide or amino acid sequence similarity searches against public (or user-customized) databases that are locally stored. It does not require any dependencies or installation and can be used from a portable flash drive. prfectBLAST is implemented in Java version 6 (SUN) and runs on all platforms that support Java and for which National Center for Biotechnology Information has made available stand-alone BLAST executables, including MS Windows, Mac OS X, and Linux. It is free and open source software, made available under the GNU General Public License version 3 (GPLv3) and can be downloaded at www.cicy.mx/sitios/jramirez or http://code.google.com/p/prfectblast/.

  8. Flexible Control of Small Wind Turbines With Grid Failure Detection Operating in Stand-Alone and Grid-Connected Mode

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Blaabjerg, Frede

    2004-01-01

    This paper presents the development and test of a flexible control strategy for an 11-kw wind turbine with a back-to-back power converter capable of working in both stand-alone and grid-connected mode. The stand-alone control is featured with a complex output voltage controller capable of handling...... nonlinear load and excess or deficit of generated power. Grid-connection mode with current control is also enabled for the case of isolated local grid involving other dispersed power generators such as other wind turbines or diesel generators. A novel automatic mode switch method based on a phase......-locked loop controller is developed in order to detect the grid failure or recovery and switch the operation mode accordingly. A flexible digital signal processor (DSP) system that allows user-friendly code development and on-line tuning is used to implement and test the different control strategies. The back...

  9. Stand-alone flat-plate photovoltaic power systems: System sizing and life-cycle costing methodology for Federal agencies

    Science.gov (United States)

    Borden, C. S.; Volkmer, K.; Cochrane, E. H.; Lawson, A. C.

    1984-01-01

    A simple methodology to estimate photovoltaic system size and life-cycle costs in stand-alone applications is presented. It is designed to assist engineers at Government agencies in determining the feasibility of using small stand-alone photovoltaic systems to supply ac or dc power to the load. Photovoltaic system design considerations are presented as well as the equations for sizing the flat-plate array and the battery storage to meet the required load. Cost effectiveness of a candidate photovoltaic system is based on comparison with the life-cycle cost of alternative systems. Examples of alternative systems addressed are batteries, diesel generators, the utility grid, and other renewable energy systems.

  10. Optimum autonomous stand-alone photovoltaic system design on the basis of energy pay-back analysis

    International Nuclear Information System (INIS)

    Kaldellis, J.K.; Zafirakis, D.; Kondili, E.

    2009-01-01

    Stand-alone photovoltaic (PV) systems comprise one of the most promising electrification solutions for covering the demand of remote consumers. However, such systems are strongly questioned due to extreme life-cycle (LC) energy requirements. For similar installations to be considered as environmentally sustainable, their LC energy content must be compensated by the respective useful energy production, i.e. their energy pay-back period (EPBP) should be found less than their service period. In this context, an optimum sizing methodology is currently developed, based on the criterion of minimum embodied energy. Various energy autonomous stand-alone PV-lead-acid battery systems are examined and two different cases are investigated; a high solar potential area and a medium solar potential area. By considering that the PV-battery (PV-Bat) system's useful energy production is equal to the remote consumer's electricity consumption, optimum cadmium telluride (CdTe) based systems yield the minimum EPBP (15 years). If achieving to exploit the net PV energy production however, the EPBP is found less than 20 years for all PV types. Finally, the most interesting finding concerns the fact that in all cases examined the contribution of the battery component exceeds 27% of the system LC energy requirements, reflecting the difference between grid-connected and stand-alone configurations.

  11. Control strategy of wind turbine based on permanent magnet synchronous generator and energy storage for stand-alone systems

    DEFF Research Database (Denmark)

    Deng, Fujin; Liu, Dong; Chen, Zhe

    2017-01-01

    This paper investigates a variable speed wind turbine based on permanent magnet synchronous generator and a full-scale power converter in a stand-alone system. An energy storage system(ESS) including battery and fuel cell-electrolyzer combination is connected to the DC link of the full-scale power...... converter through the power electronics interface. Wind is the primary power source of the system, the battery and FC-electrolyzer combination is used as a backup and a long-term storage system to provide or absorb power in the stand-alone system, respectively. In this paper, a control strategy is proposed...... for the operation of this variable speed wind turbine in a stand-alone system, where the generator-side converter and the ESS operate together to meet the demand of the loads. This control strategy is competent for supporting the variation of the loads or wind speed and limiting the DC-link voltage of the full...

  12. Methanol production via pressurized entrained flow biomass gasification – Techno-economic comparison of integrated vs. stand-alone production

    International Nuclear Information System (INIS)

    Andersson, Jim; Lundgren, Joakim; Marklund, Magnus

    2014-01-01

    The main objective with this work was to investigate techno-economically the opportunity for integrated gasification-based biomass-to-methanol production in an existing chemical pulp and paper mill. Three different system configurations using the pressurized entrained flow biomass gasification (PEBG) technology were studied, one stand-alone plant, one where the bark boiler in the mill was replaced by a PEBG unit and one with a co-integration of a black liquor gasifier operated in parallel with a PEBG unit. The cases were analysed in terms of overall energy efficiency (calculated as electricity-equivalents) and process economics. The economics was assessed under the current as well as possible future energy market conditions. An economic policy support was found to be necessary to make the methanol production competitive under all market scenarios. In a future energy market, integrating a PEBG unit to replace the bark boiler was the most beneficial case from an economic point of view. In this case the methanol production cost was reduced in the range of 11–18 Euro per MWh compared to the stand-alone case. The overall plant efficiency increased approximately 7%-units compared to the original operation of the mill and the non-integrated stand-alone case. In the case with co-integration of the two parallel gasifiers, an equal increase of the system efficiency was achieved, but the economic benefit was not as apparent. Under similar conditions as the current market and when methanol was sold to replace fossil gasoline, co-integration of the two parallel gasifiers was the best alternative based on received IRR. - Highlights: • Techno-economic results regarding integration of methanol synthesis processes in a pulp and paper mill are presented. • The overall energy efficiency increases in integrated methanol production systems compared to stand-alone production units. • The economics of the integrated system improves compared to stand-alone alternatives. • Tax

  13. Stand-Alone Personalized Normative Feedback for College Student Drinkers: A Meta-Analytic Review, 2004 to 2014.

    Directory of Open Access Journals (Sweden)

    Keri B Dotson

    Full Text Available Norms clarification has been identified as an effective component of college student drinking interventions, prompting research on norms clarification as a single-component intervention known as Personalized Normative Feedback (PNF. Previous reviews have examined PNF in combination with other components but not as a stand-alone intervention.To investigate the degree to which computer-delivered stand-alone personalized normative feedback interventions reduce alcohol consumption and alcohol-related harms among college students and to compare gender-neutral and gender-specific PNF.Electronic databases were searched systematically through November 2014. Reference lists were reviewed manually and forward and backward searches were conducted.Outcome studies that compared computer-delivered, stand-alone PNF intervention with an assessment only, attention-matched, or active treatment control and reported alcohol use and harms among college students.Between-group effect sizes were calculated as the standardized mean difference in change scores between treatment and control groups divided by pooled standard deviation. Within-group effect sizes were calculated as the raw mean difference between baseline and follow-up divided by pooled within-groups standard deviation.Eight studies (13 interventions with a total of 2,050 participants were included. Compared to control participants, students who received gender-neutral (dbetween = 0.291, 95% CI [0.159, 0.423] and gender-specific PNF (dbetween = 0.284, 95% CI [0.117, 0.451] reported greater reductions in drinking from baseline to follow-up. Students who received gender-neutral PNF reported 3.027 (95% CI [2.171, 3.882] fewer drinks per week at first follow-up and gender-specific PNF reported 3.089 (95% CI [0.992, 5.186] fewer drinks. Intervention effects were small for harms (dbetween = 0.157, 95% CI [0.037, 0.278].Computer-delivered PNF is an effective stand-alone approach for reducing college student

  14. Stand-Alone Personalized Normative Feedback for College Student Drinkers: A Meta-Analytic Review, 2004 to 2014.

    Science.gov (United States)

    Dotson, Keri B; Dunn, Michael E; Bowers, Clint A

    2015-01-01

    Norms clarification has been identified as an effective component of college student drinking interventions, prompting research on norms clarification as a single-component intervention known as Personalized Normative Feedback (PNF). Previous reviews have examined PNF in combination with other components but not as a stand-alone intervention. To investigate the degree to which computer-delivered stand-alone personalized normative feedback interventions reduce alcohol consumption and alcohol-related harms among college students and to compare gender-neutral and gender-specific PNF. Electronic databases were searched systematically through November 2014. Reference lists were reviewed manually and forward and backward searches were conducted. Outcome studies that compared computer-delivered, stand-alone PNF intervention with an assessment only, attention-matched, or active treatment control and reported alcohol use and harms among college students. Between-group effect sizes were calculated as the standardized mean difference in change scores between treatment and control groups divided by pooled standard deviation. Within-group effect sizes were calculated as the raw mean difference between baseline and follow-up divided by pooled within-groups standard deviation. Eight studies (13 interventions) with a total of 2,050 participants were included. Compared to control participants, students who received gender-neutral (dbetween = 0.291, 95% CI [0.159, 0.423]) and gender-specific PNF (dbetween = 0.284, 95% CI [0.117, 0.451]) reported greater reductions in drinking from baseline to follow-up. Students who received gender-neutral PNF reported 3.027 (95% CI [2.171, 3.882]) fewer drinks per week at first follow-up and gender-specific PNF reported 3.089 (95% CI [0.992, 5.186]) fewer drinks. Intervention effects were small for harms (dbetween = 0.157, 95% CI [0.037, 0.278]). Computer-delivered PNF is an effective stand-alone approach for reducing college student drinking and

  15. Hierarchical energy management system for stand-alone hybrid system based on generation costs and cascade control

    International Nuclear Information System (INIS)

    Torreglosa, J.P.; García, P.; Fernández, L.M.; Jurado, F.

    2014-01-01

    Highlights: • We present an energy management system for a stand-alone WT/PV/hydrogen/battery hybrid system. • Hierarchical control composed by master and slave control strategies. • Control assures reliable electricity support for stand-alone applications subject to technical and economic criteria. - Abstract: This paper presents an energy management system (EMS) for stand-alone hybrid systems composed by photovoltaic (PV) solar panels and a wind turbine (WT) as primary energy sources and two energy storage systems, which are a hydrogen system and a battery. The hydrogen system is composed of fuel cell (FC), electrolyzer and hydrogen storage tank. The EMS is a hierarchical control composed by a master control strategy and a slave control strategy. On the one hand, the master control generates the reference powers to meet several premises (such as to satisfy the load power demand, and to maintain the hydrogen tank level and the state of charge (SOC) of the battery between their target margins), taking also into account economic aspects to discriminate between using the battery or hydrogen system. On the other hand, the slave control modifies the reference powers generated by the master control according to the energy sources dynamic limitations, and maintains the DC bus voltage at its reference value. The models, implemented in MATLAB-Simulink environment, have been developed from commercially available components. To check the viability of the proposed EMS, two kinds of simulations were carried out: (1) A long-term simulation of 25 years (expected lifetime of the system) with a sample time of one hour to validate the master control of the EMS; and (2) A short-term simulation with sudden net power variations to validate the slave control of the EMS

  16. Use of stand-alone anchored intervertebral cage in the surgical treatment of patients with symptomatic cervical spondylosis

    Directory of Open Access Journals (Sweden)

    Tilen Žele

    2015-03-01

    Full Text Available Background:One of the most common surgical operations for treatment of cervical spondylosis is anterior cervical discectomy with fusion (ACDF. In order to achieve stable fusion after discectomy and avoid dysphagia the artificial stand-alone zero-profile cages with integrated screws were developed and introduced into clinical practice. Outcome and complications after ACDF with such cages were not adequately assessed yet.Methods:We analyzed 20 consecutive patients with cervical spondylosis treated in our institution with ACDF with stand-alone zero-profile cage Zero-P. Before and after surgery and then 6, 12 and 24 months after surgery we assessed the level of pain with VAS scale, severity of myelopathy with mJOA scale and dysphagia with four level scale. Treatment outcome was assessed after 2 years according to Odom's criteria.Results:No complications occurred during surgery or recovery after surgery. The VAS score after surgery and then after 6, 12 and 24 months was statistically significantly lower than before surgery (p<0.05. The mJOA scores were 6, 12 and 24 months after surgery statistically significantly higher than before surgery (p<0.05. Transient and mild dysphagia was present after surgery in 15% (3/20 of patients and 6, 12 or 24 months after surgery in none. Outcome after 2 years was excellent in 9 patients and good in 11 patients.Conclusions:Operative treatment of symptomatic cervical spondylosis with ACDF using stand-alone zero-profile cage with integrated screws is safe and efficient. Incidence of dysphagia after surgery is low and generally transient.

  17. An optimized Fuzzy Logic Controller by Water Cycle Algorithm for power management of Stand-alone Hybrid Green Power generation

    International Nuclear Information System (INIS)

    Sarvi, Mohammad; Avanaki, Isa Nasiri

    2015-01-01

    Highlights: • A new method to improve the performance of renewable power management is proposed. • The proposed method is based on Fuzzy Logic optimized by the Water Cycle Algorithm. • The proposed method characteristics are compared with two other methods. • The comparisons confirm that the proposed method is robust and effectiveness one. - Abstract: This paper aims to improve the power management system of a Stand-alone Hybrid Green Power generation based on the Fuzzy Logic Controller optimized by the Water Cycle Algorithm. The proposed Stand-alone Hybrid Green Power consists of wind energy conversion and photovoltaic systems as primary power sources and a battery, fuel cell, and Electrolyzer as energy storage systems. Hydrogen is produced from surplus power generated by the wind energy conversion and photovoltaic systems of Stand-alone Hybrid Green Power and stored in the hydrogen storage tank for fuel cell later using when the power generated by primary sources is lower than load demand. The proposed optimized Fuzzy Logic Controller based power management system determines the power that is generated by fuel cell or use by Electrolyzer. In a hybrid system, operation and maintenance cost and reliability of the system are the important issues that should be considered in studies. In this regard, Water Cycle Algorithm is used to optimize membership functions in order to simultaneously minimize the Loss of Power Supply Probability and operation and maintenance. The results are compared with the particle swarm optimization and the un-optimized Fuzzy Logic Controller power management system to prove that the proposed method is robust and effective. Reduction in Loss of Power Supply Probability and operation and maintenance, are the most advantages of the proposed method. Moreover the level of the State of Charge of the battery in the proposed method is higher than other mentioned methods which leads to increase battery lifetime.

  18. Optimization of a stand-alone Solar PV-Wind-DG Hybrid System for Distributed Power Generation at Sagar Island

    Science.gov (United States)

    Roy, P. C.; Majumder, A.; Chakraborty, N.

    2010-10-01

    An estimation of a stand-alone solar PV and wind hybrid system for distributed power generation has been made based on the resources available at Sagar island, a remote area distant to grid operation. Optimization and sensitivity analysis has been made to evaluate the feasibility and size of the power generation unit. A comparison of the different modes of hybrid system has been studied. It has been estimated that Solar PV-Wind-DG hybrid system provides lesser per unit electricity cost. Capital investment is observed to be lesser when the system run with Wind-DG compared to Solar PV-DG.

  19. Losses Evaluation for a Two-Level Three-Phase Stand-Alone Voltage Source Converter Using Model Predictive Control

    DEFF Research Database (Denmark)

    Al hasheem, Mohamed; Dragicevic, Tomislav; Rivera, Marco

    2017-01-01

    conventional and improved controller is conducted in terms of losses. The switching and conduction losses for the VSC are calculated using MATLAB/SIMULINK and PLECS software. A power level up to 1 kW is considered for the conventional and the improved schemes. All simulation and experimental results......This paper discusses a Model Predictive Control (MPC) scheme for a Voltage Source Converter (VSC) where the aim is to minimize losses and Total Harmonics distortion (THD) compared to the conventional MPC scheme. Different Cost Functions (CFs) are applied to the stand-alone VSC. A comparison between...

  20. Dynamic behavior of PEM FCPPs under various load conditions and voltage stability analysis for stand-alone residential applications

    Science.gov (United States)

    Uzunoglu, M.; Onar, O. C.; Alam, M. S.

    In this paper, dynamic behavior and performance of a fuel cell power plant (FCPP) which operates in parallel with a battery bank is tested under classified load conditions, such as mostly resistive, mostly inductive, resistive-inductive and non-linear loads. Thereafter, voltage stability analysis is performed using the dynamic response of the FCPP for stand-alone residential applications. Simulation results are obtained using the MATLAB ® and Simulink ® software packages, based on the mathematical and dynamic electrical models of the system. Using the experimental results, a validated model has been realized and voltage stability analysis is performed through this model.

  1. Economic and Environmental Assessment of a Renewable Stand-Alone Energy Supply System Using Multi-objective Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dohyun; Han, Seulki; Kim, Jiyong Kim [Incheon National University, Incheon (Korea, Republic of)

    2017-06-15

    This study aims to propose a new optimization-based approach for design and analysis of the stand-alone hybrid energy supply system using renewable energy sources (RES). In the energy supply system, we include multiple energy production technologies such as Photovoltaics (PV), Wind turbine, and fossil-fuel-based AC generator along with different types of energy storage and conversion technologies such as battery and inverter. We then select six different regions of Korea to represent various characteristics of different RES potentials and demand profiles. We finally designed and analyzed the optimal RES stand-alone energy supply system in the selected regions using multiobjective optimization (MOOP) technique, which includes two objective functions: the minimum cost and the minimum CO{sub 2} emission. In addition, we discussed the feasibility and expecting benefits of the systems by comparing to conventional systems of Korea. As a result, the region of the highest RES potential showed the possibility to remarkably reduce CO{sub 2} emissions compared to the conventional system. Besides, the levelized cost of electricity (LCOE) of the RES-based energy system is identified to be slightly higher than conventional energy system: 0.35 and 0.46 $/kWh, respectively. However, the total life-cycle emission of CO{sub 2} (LCECO{sub 2}) can be reduced up to 470 gCO{sub 2}/kWh from 490 gCO{sub 2}/kWh of the conventional systems.

  2. Comparison of pulp-mill-integrated hydrogen production from gasified black liquor with stand-alone production from gasified biomass

    International Nuclear Information System (INIS)

    Andersson, E.; Harvey, S.

    2007-01-01

    When gasified black liquor is used for hydrogen production, significant amounts of biomass must be imported. This paper compares two alternative options for producing hydrogen from biomass: (A) pulp-mill-integrated hydrogen production from gasified back liquor; and (B) stand-alone production of hydrogen from gasified biomass. The comparison assumes that the same amount of biomass that is imported in Alternative A is supplied to a stand-alone hydrogen production plant and that the gasified black liquor in Alternative B is used in a black liquor gasification combined cycle (BLGCC) CHP unit. The comparison is based upon equal amounts of black liquor fed to the gasifier, and identical steam and power requirements for the pulp mill. The two systems are compared on the basis of total CO 2 emission consequences, based upon different assumptions for the reference energy system that reflect different societal CO 2 emissions reduction target levels. Ambitions targets are expected to lead to a more CO 2 -lean reference energy system, in which case hydrogen production from gasified black liquor (Alternative A) is best from a CO 2 emissions' perspective, whereas with high CO 2 emissions associated with electricity production, hydrogen from gasified biomass and electricity from gasified black liquor (Alternative B) is preferable. (author)

  3. Multi-objective optimal planning of the stand-alone microgrid system based on different benefit subjects

    International Nuclear Information System (INIS)

    Guo, Li; Wang, Nan; Lu, Hai; Li, Xialin; Wang, Chengshan

    2016-01-01

    As an important means to realize the energetic complementarity and improve the efficiency of renewable resources, the stand-alone microgrid (SAMG) system gains attention increasingly, especially in islands and remote areas. In this paper, considering the interest conflict of the distribution company and the distributed generation owner, a new multi-objective optimal planning model is formulated for medium voltage SAMG. Besides, to avoid the power constraint of distributed generation (DG) once the over-limit voltage occurs, a novel two-step power dispatch control method including the voltage regulation strategy is proposed, in which the absorption of distributed power by energy storage system (ESS) and the reactive power adjustment though its power control system are used to regulate voltage. The goal of this paper is to search the Pareto-optimal front of the site and capacity of DG as well as the contract price between both parties, and thus can provide effective references for practical planning of SAMG. Considering the high cost of ESS, the investment analysis of ESS is also discussed in the paper. - Highlights: • A multi-objective planning model based on different benefit subjects is proposed. • A two-step power dispatch method including the voltage regulation is proposed. • The economical efficiency of the proposed model is analyzed. • The effective reference for the stand-alone microgrid planning is provided.

  4. SedInConnect: a stand-alone, free and open source tool for the assessment of sediment connectivity

    Science.gov (United States)

    Crema, Stefano; Cavalli, Marco

    2018-02-01

    There is a growing call, within the scientific community, for solid theoretic frameworks and usable indices/models to assess sediment connectivity. Connectivity plays a significant role in characterizing structural properties of the landscape and, when considered in combination with forcing processes (e.g., rainfall-runoff modelling), can represent a valuable analysis for an improved landscape management. In this work, the authors present the development and application of SedInConnect: a free, open source and stand-alone application for the computation of the Index of Connectivity (IC), as expressed in Cavalli et al. (2013) with the addition of specific innovative features. The tool is intended to have a wide variety of users, both from the scientific community and from the authorities involved in the environmental planning. Thanks to its open source nature, the tool can be adapted and/or integrated according to the users' requirements. Furthermore, presenting an easy-to-use interface and being a stand-alone application, the tool can help management experts in the quantitative assessment of sediment connectivity in the context of hazard and risk assessment. An application to a sample dataset and an overview on up-to-date applications of the approach and of the tool shows the development potential of such analyses. The modelled connectivity, in fact, appears suitable not only to characterize sediment dynamics at the catchment scale but also to integrate prediction models and as a tool for helping geomorphological interpretation.

  5. A Control Approach and Supplementary Controllers for a Stand-Alone System with Predominance of Wind Generation

    Directory of Open Access Journals (Sweden)

    Tiago Lukasievicz

    2018-02-01

    Full Text Available This paper proposes a control approach and supplementary controllers for the operation of a hybrid stand-alone system composed of a wind generation unit and a conventional generation unit based on synchronous generator (CGU. The proposed controllers allow the islanded or isolated operation of small power systems with predominance of wind generation. As an advantage and a paradigm shift, the DC-link voltage of the wind unit is controlled by means of a conventional synchronous generator connected to the AC grid of the system. Two supplementary controllers, added to a diesel generator (DIG and to a DC dump load (DL, are proposed to control the DC-link voltage. The wind generation unit operates in V-f control mode and the DIG operates in PQ control mode, which allows the stand-alone system to operate either in wind-diesel (WD mode or in wind-only (WO mode. The strong influence of the wind turbine speed variations in the DC-link voltage is mitigated by a low-pass filter added to the speed control loop of the wind turbine. The proposed control approach does not require the use battery bank and ultra-capacitor to control the DC-link voltage in wind generation units based on fully rated converter.

  6. Study on Soft Phase Locked Method to Solving the Synchronization Problem of Active Power Filter in Stand-alone Power Grid

    DEFF Research Database (Denmark)

    Zhuo, Fang; Wu, Longhui; Chen, Zhe

    2009-01-01

    on zero-cross detection can't work effectively in small rating stand-alone power grid. Then a soft phase locked loop with additional filter is proposed. It can lock the phase angle on to the positive sequence of fundamental voltage accurately and rapidly. It ensures the performance of APF applied...... in the small rating stand-alone power grid. Moreover, the soft phase locked loop is easy to be implemented in a Digital Signal Processor (DSP). Simulation and experimental results validate that the soft phase locked loop has satisfactory performance.......Traditional LC filters can't work stably in small rating stand-alone power grid. So active power filter (APF) is becoming an important tool to solve the power quality problem in small rating stand-alone power grid. In most current detection algorithm of APF, it needs a synchronizing signal. Firstly...

  7. Clinical and radiological outcome after anterior cervical discectomy and fusion with stand-alone empty polyetheretherketone (PEEK) cages.

    Science.gov (United States)

    Shiban, Ehab; Gapon, Karina; Wostrack, Maria; Meyer, Bernhard; Lehmberg, Jens

    2016-02-01

    To evaluate long-term results after one-, two-, and three-level anterior cervical discectomy and fusion (ACDF) with stand-alone empty polyetheretherketone (PEEK) cages. We performed a retrospective review of a consecutive patient cohort that underwent ACDF with stand-alone empty PEEK cages between 2007 and 2010 with a minimum follow-up of 12 months. Radiographic follow-up included static and flexion/extension radiographs. Changes in the operated segments were measured and compared to radiographs directly after surgery. Clinical outcome was evaluated by a physical examination, pain visual analog scale (VAS), and health-related quality of life (HRQL) using the EuroQOL questionnaire (EQ-5D). Analysis of associations between fusion, subsidence, cervical alignment, and clinical outcome parameters were performed. Of 407 consecutive cases, 318 met all inclusion criteria. Follow-up data were obtained from 265 (83 %) cases. The mean age at presentation was 55 years and 139 patients were male (52 %). In the sample, 127, 125, and 13 patients had one-, two-, and three-level surgeries, respectively; 132 (49 %) presented with spondylotic cervical myelopathy and 133 (50 %) with cervical radiculopathy. Fusion was achieved in 85, 95, and 94 % of segments in one-, two-, and three-level surgeries, respectively. Non-fusion was associated with higher VAS pain levels. Radiographic adjacent segment disease (ASD) was observed in 20, 29, and 15 % in one-, two-, and three-level surgeries, respectively. ASD was associated with lower HRQL. Subsidence was observed in 25, 27, and 15 % of segments in one-, two-, and three-level surgeries, respectively. However, this had no influence on clinical outcome. Follow-up operations for symptomatic adjacent disc disease and implant failure at index level were needed in 16 (6 %) and four (1.5 %) cases, respectively. Younger age was associated with better clinical outcome. Multilevel surgery favored better myelopathy outcomes and fusion reduced overall

  8. Online retrieval of patient information by asynchronous communication between general purpose computer and stand-alone personal computer

    International Nuclear Information System (INIS)

    Tsutsumi, Reiko; Takahashi, Kazuei; Sato, Toshiko; Komatani, Akio; Yamaguchi, Koichi

    1988-01-01

    Asynchronous communication was made between host (FACOM M-340) and personal computer (OLIBETTIE S-2250) to get patient's information required for RIA test registration. The retrieval system consists of a keyboad input of six numeric codes, patient's ID, and a real time reply containing six parameters for the patient. Their identified parameters are patient's name, sex, date of birth (include area), department, and out- or inpatient. Linking this program to RIA registration program for individual patient, then, operator can input name of RIA test requested. Our simple retrieval program made a useful data network between different types of host and stand-alone personal computers, and enabled us accurate and labor-saving registration for RIA test. (author)

  9. Life cycle assessment study of a 4.2 kW{sub p} stand-alone photovoltaic system

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Valverde, R.; Miguel, C.; Urbina, A. [Universidad Politecnica de Cartagena, Departamento de Electronica, Tecnologia de Computadoras y Proyectos, Campus Muralla del Mar, 30203, Cartagena, Murcia (Spain); Martinez-Bejar, R. [Universidad de Murcia, Departamento de Ingenieria de la Informacion y las Comunicaciones, Facultad de Informatica, Campus de Espinardo, 30071, Murcia (Spain)

    2009-09-15

    The energetic and environmental life cycle assessment of a 4.2 kW{sub p} stand-alone photovoltaic system (SAPV) at the University of Murcia (south-east of Spain) is presented. PV modules and batteries are the energetically and environmentally most expensive elements. The energy pay-back time was found to be 9.08 years and the specific CO{sub 2} emissions was calculated as 131 g/kWh. The SAPV system has been environmentally compared with other supply options (diesel generator and Spanish grid) showing lower impacts in both cases. The results show the CO{sub 2}-emission reduction potential of SAPV systems in southern European countries and point out the critical environmental issues in these systems. (author)

  10. Integration of hydrogen energy technologies in stand-alone power systems analysis of the current potential for applications

    International Nuclear Information System (INIS)

    Zoulias, E.I.; Lymberopoulos, N.; Tsoutsos, T.; Glockner, R.; Mydske, H.J.; Vosseler, I.; Gavalda, O.; Taylor, P.

    2006-01-01

    The European study entitled: 'Market Potential Analysis for Introduction of Hydrogen Energy Technology in Stand-Alone Power Systems (H-SAPS)' aimed to establish a broad understanding of the market potential for H-SAPS and provide a basis for promoting in wide scale new technological applications. The scope of the study was limited to small and medium installations, up to a few hundred kW power rating and based on RE as the primary energy source. The potential for hydrogen technology in SAPS was investigated through an assessment of the technical potential for hydrogen, the market analysis and the evaluation of external factors. The results are mostly directed towards action by governments and the research community but also industry involvement is identified. The results include targeted market research, establishment of individual cost targets, regulatory changes to facilitate alternative grid solutions, information and capacity building, focused technology research and bridging the technology gaps. (author)

  11. A Freshman Biochemistry Course.

    Science.gov (United States)

    De Toma, Francis J.; Campbell, Mary K.

    1982-01-01

    A one-semester biochemistry course was developed as an alternative to traditional freshman chemistry. Lecture topics and laboratory exercises focus on the course's unifying theme of the origin and early stages of the evolution of life on earth. (Author/SK)

  12. Extra-peritoneal pressure packing without external pelvic fixation: A life-saving stand-alone surgical treatment

    Directory of Open Access Journals (Sweden)

    Guy Ron

    2015-01-01

    Full Text Available Purpose: Traditional maneuvers aim to decrease retroperitoneal bleeding in hemodynamically unstable multi-trauma patients with unstable pelvic fractures, are reportedly successful in approximately only 50%. The life-saving effect of extra-peritoneal pressure packing (EPPP is based on direct compression and control of both venous and arterial retroperitoneal bleeders. This study describes the safety and efficacy of emergent EPPP employment, as a stand-alone surgical treatment, that is, carried out without external pelvic fixation or emergent angiography. Materials and Methods: A retrospective chart review of all hemodynamic unstable, multi-trauma patients with mechanically unstable pelvic fractures treated by the EPPP technique at our medical center between the years 2005 and 2011. Survival rates, clinical, and physiological outcomes were followed prospectively. Results: Twenty-five of the 181 pelvic fracture patients had biomechanically unstable fractures that required surgical fixation. Fourteen of those 25 patients had deteriorating hemodynamic instability from massive pelvic bleeding which was resistant to resuscitation, and they underwent EPPP, as a stand-alone treatment. The procedure successfully achieved hemodynamic stability in all 14 patients and obviated the early mortality associated with massive pelvic bleeding. Three of these patients eventually succumbed to their multiple injuries. Conclusion: Implementation of EPPP improved all measured physiological outcome parameters and survival rates of hemodynamically unstable multi-trauma patients with unstable pelvic fractures in our trauma center. It provided the unique advantage of directly compressing the life-threatening retroperitoneal bleeders by applying direct pressure and causing a tamponade effect to stanch venous and arterial pelvic blood flow and obviate the early mortality associated with massive pelvic bleeding.

  13. Leadership in Dental Hygiene Degree Completion Programs: A Pilot Study Comparing Stand-Alone Leadership Courses and Leadership-Infused Curricula.

    Science.gov (United States)

    Smith, Michelle L; Gurenlian, JoAnn R; Freudenthal, Jacqueline J; Farnsworth, Tracy J

    2016-05-01

    The aim of this study was to define the extent to which leadership and leadership skills are taught in dental hygiene degree completion programs by comparing stand-alone leadership courses/hybrid programs with programs that infuse leadership skills throughout the curricula. The study involved a mixed-methods approach using qualitative and quantitative data. Semi-structured interviews were conducted with program directors and faculty members who teach a stand-alone leadership course, a hybrid program, or leadership-infused courses in these programs. A quantitative comparison of course syllabi determined differences in the extent of leadership content and experiences between stand-alone leadership courses and leadership-infused curricula. Of the 53 U.S. dental hygiene programs that offer degree completion programs, 49 met the inclusion criteria, and 19 programs provided course syllabi. Of the program directors and faculty members who teach a stand-alone leadership course or leadership-infused curriculum, 16 participated in the interview portion of the study. The results suggested that competencies related to leadership were not clearly defined or measurable in current teaching. Reported barriers to incorporating a stand-alone leadership course included overcrowded curricula, limited qualified faculty, and lack of resources. The findings of this study provide a synopsis of leadership content and gaps in leadership education for degree completion programs. Suggested changes included defining a need for leadership competencies and providing additional resources to educators such as courses provided by the American Dental Education Association and the American Dental Hygienists' Association.

  14. A cross-sectional study of stand-alone percutaneous coronary intervention in a Nigerian cardiac catheterization laboratory.

    Science.gov (United States)

    Johnson, Adeyemi; Falase, Bode; Ajose, Ifeoluwa; Onabowale, Yemi

    2014-01-16

    There is a paucity of diagnostic and therapeutic facilities in Nigeria to confirm coronary artery disease and offer appropriate interventional therapy. There is now a private cardiac catheterization laboratory in Lagos but as there are no sustained Open Heart Surgery programmes, percutaneous coronary interventions are currently being performed without surgical backup. This study was designed to assess results of stand-alone percutaneous coronary intervention (PCI) as currently practiced in Lagos, Nigeria. This cross-sectional study was conducted between July 2009 and July 2012. The study included all patients that underwent PCI in Lagos. Data was extracted from a prospectively maintained database. Coronary artery disease was confirmed in 80 (52.6%) of 152 Nigerians referred with a diagnosis of Ischaemic Heart Disease. There were 53 males (66.2%) and 27 females (33.8%). The average age was 60.3 +/-9.6 years and average euroscore was 4.5 +/-3.1. Of the 80 patients, 77 (96.3%) had significant stenoses and were candidates for revascularization. Distribution of significant stenoses was one in 32 patients (41.5%), two in 11 patients (14.3%), three in 19 patients (24.7%), four in 13 patients (16.9%) and five in 2 patients (2.6%). PCI was performed in 48 (62.3%) of the patients eligible for revascularization as the coronary anatomy in the remaining patients was not suitable for PCI. The indication for PCI was for myocardial infarction or unstable angina in 39 patients (81.2%). PCI was performed with PTCA plus stenting in 41 patients (85.4%) and with PTCA alone in 7 patients (14.6%) with good angiographic results. Overall 29 of the 48 patients (60.4%) had complete revascularization of significant stenoses. Complications of PCI were bleeding that required blood transfusion in 1 patient (2.1%), minor femoral haematomas in 2 patients (4.2%), and a major adverse clinical event in 1 patient (2.1%). A stand-alone PCI programme has been developed in Lagos, Nigeria. Both elective

  15. Adaptive Artificial intelligence based fuzzy logic MPPTcontrol for stande-alone photovoltaic system under different atmospheric conditions

    Directory of Open Access Journals (Sweden)

    Zaghba Layachi

    2015-08-01

    Full Text Available there is an increased need for analysing the effect of atmospheric variables on photovoltaic (PV production and performance. The outputs from the different PV cells in different atmospheric conditions, such as irradiation and temperature , differ from each other evidencing knowledge deficiency in PV systems [14]. Maximum power point tracking (MPPT methods are used to maximize the PV array output power by tracking continuously the maximum power point (MPP. Among all MPPT methods existing in the literature, perturb and observe (P&O is the most commonly used for its simplicity and ease of implementation; however, it presents drawbacks such as slow response speed, oscillation around the MPP in steady state, and even tracking in wrong way under rapidly changing atmospheric conditions. In order to allow a functioning around the optimal point Mopt, we have inserted a DC-DC converter (Buck–Boost for a better matching between the PV and the load. This paper, we study the Maximum power point tracking using adaptive Intelligent fuzzy logic and conventional (P&O control for stande-alone photovoltaic Array system .In particular, the performances of the controllers are analyzed under variation weather conditions with are constant temperature and variable irradiation. The proposed system is simulated by using MATLAB-SIMULINK. According to the results, fuzzy logic controller has shown better performance during the optimization.

  16. Modeling and Experimental Test of Grid-Tied Photovoltaic Cell Emulating System in the Stand-alone Mode

    Directory of Open Access Journals (Sweden)

    Vu Minh Phap

    2017-06-01

    Full Text Available In recent decades, generation of electricity from solar arrays has been increased to meet the world's growing energy demand. However, the utilization rate of the power conditioner in the grid-tied solar power system is low because the operation of solar panels is dependent on sunlight. Thus, we studied the method that the small scale wind power generating system in size from a few hundred watts to two or three kilowatts can be connected to the grid-tied power conditioner of the solar power system for residential applications with low power ratings (single phase, size is limited to 10kW by emulating characteristic of the solar panel. In this paper, we introduce the application of the grid-tied PV cell emulating system in the stand-alone mode to improve the utilization rate of the power conditioner. The simulation and experimental test results verify that the PV cell emulating system can operate the power conditioner of the gridtied solar power system.

  17. Automation infrastructure and operation control strategy in a stand-alone power system based on renewable energy sources

    Science.gov (United States)

    Ziogou, Chrysovalantou; Ipsakis, Dimitris; Elmasides, Costas; Stergiopoulos, Fotis; Papadopoulou, Simira; Seferlis, Panos; Voutetakis, Spyros

    The design of the automation system and the implemented operation control strategy in a stand-alone power system in Greece are fully analyzed in the present study. A photovoltaic array and three wind generators serve as the system main power sources and meet a predefined load demand. A lead-acid accumulator is used to compensate the inherent power fluctuations (excess or shortage) and to regulate the overall system operation, based on a developed power management strategy. Hydrogen is produced by using system excess power in a proton exchange membrane (PEM) electrolyzer and is further stored in pressurized cylinders for subsequent use in a PEM fuel cell in cases of power shortage. A diesel generator complements the integrated system and is employed only in emergency cases, such as subsystems failure. The performance of the automatic control system is evaluated through the real-time operation of the power system where data from the various subsystems are recorded and analyzed using a supervised data acquisition unit. Various network protocols were used to integrate the system devices into one central control system managing in this way to compensate for the differences between chemical and electrical subunits. One of the main advantages is the ability of process monitoring from distance where users can perform changes to system principal variables. Furthermore, the performance of the implemented power management strategy is evaluated through simulated scenarios by including a case study analysis on system abilities to meet higher than expected electrical load demands.

  18. Stand-alone power systems for the future: Optimal design, operation and control of solar-hydrogen energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Ulleberg, Oeystein

    1998-12-31

    This thesis gives a systematic review of the fundamentals of energy systems, the governing physical and chemical laws related to energy, inherent characteristics of energy system, and the availability of the earth`s energy. It shows clearly why solar-hydrogen systems are one of the most viable options for the future. The main subject discussed is the modelling of SAPS (Stand-Alone Power Systems), with focus on photovoltaic-hydrogen energy systems. Simulation models for a transient simulation program are developed for PV-H{sub 2} components, including models for photovoltaics, water electrolysis, hydrogen storage, fuel cells, and secondary batteries. A PV-H{sub 2} demonstration plant in Juelich, Germany, is studied as a reference plant and the models validated against data from this plant. Most of the models developed were found to be sufficiently accurate to perform short-term system simulations, while all were more than accurate enough to perform long-term simulations. Finally, the verified simulation models are used to find the optimal operation and control strategies of an existing PV-H{sub 2} system. The main conclusion is that the simulation methods can be successfully used to find optimal operation and control strategies for a system with fixed design, and similar methods could be used to find alternative system designs. 148 refs., 78 figs., 31 tabs.

  19. Multi-Objective Optimal Design of Stand-Alone Hybrid Energy System Using Entropy Weight Method Based on HOMER

    Directory of Open Access Journals (Sweden)

    Jiaxin Lu

    2017-10-01

    Full Text Available Implementation of hybrid energy system (HES is generally considered as a promising way to satisfy the electrification requirements for remote areas. In the present study, a novel decision making methodology is proposed to identify the best compromise configuration of HES from a set of feasible combinations obtained from HOMER. For this purpose, a multi-objective function, which comprises four crucial and representative indices, is formulated by applying the weighted sum method. The entropy weight method is employed as a quantitative methodology for weighting factors calculation to enhance the objectivity of decision-making. Moreover, the optimal design of a stand-alone PV/wind/battery/diesel HES in Yongxing Island, China, is conducted as a case study to validate the effectiveness of the proposed method. Both the simulation and optimization results indicate that, the optimization method is able to identify the best trade-off configuration among system reliability, economy, practicability and environmental sustainability. Several useful conclusions are given by analyzing the operation of the best configuration.

  20. Development of a Laser-Powered Dielectric Structure-Based Accelerator as a Stand-Alone Particle Source

    International Nuclear Information System (INIS)

    Yoder, R. B.; Travish, G.; Arab, E. R.; Fong, D.; Hoyer, Z.; Lacroix, U. H.; Vartanian, N.; Rosenzweig, J. B.

    2010-01-01

    An experimental program to develop and build a dielectric-based slab-symmetric structure (the micro-accelerator platform, or MAP) for generating and accelerating low-energy electrons is underway at UCLA and Manhattanville College. This optical acceleration structure is effectively a resonant cavity powered by a side-coupled laser, and has applications as a radiation source for medicine or industry. We present recent experimental and computational results on the accelerator, and progress toward its incorporation into a self-contained particle source. Such a particle source would incorporate a micron-scale electron emitter and a non-relativistic capture region to enable self-injection into the synchronous field within the accelerator. A prototype of the accelerator itself has been constructed from candidate dielectric materials using micromanufacturing techniques; the current status of the testing program is described. A novel electron emitter incorporating pyroelectric crystals with field-enhancing tips has been demonstrated to produce steady currents; the results are dependent on tip geometry, and appear suitable for injection into a microstructure. Extension of the MAP concept to non-relativistic velocities, as in the stand-alone source, requires a tapered structure that gives rise to numerous complications including beam defocusing and manufacturing challenges; approaches for addressing these complications are mentioned.

  1. Life cycle assessment of stand-alone photovoltaic (SAPV) system under on-field conditions of New Delhi, India

    International Nuclear Information System (INIS)

    Sharma, Rakhi; Tiwari, G.N.

    2013-01-01

    In this paper, life cycle analysis has been carried out to evaluate overall performance of given rated stand-alone solar photovoltaic (SAPV) in terms of basic energy matrices, life cycle cost analysis, and earned carbon credit. Further, the experimentally calculated actual on-field life cycle performance results of existing outdoor SAPV system (i.e. almost 20 years old) have been represented with respect to the potential (max.) performance of same SAPV system estimated under same environmental conditions of solar intensity, ambient temperature, PV operating temperature as obtained during actual on-field performance evaluation. This new approach of overall performance evaluation by considering the on-field SAPV system installation as new (i.e. with potential/max. performance) and old (i.e. with actual performance) under same environmental conditions provides an inclusive comparative life cycle assessment of on-field PV system. - Highlights: • We present comparative life cycle assessment methodology for outdoor PV system. • We evaluate on-field PV system life performance by considering it as new and old. • We examine fall in actual on-field PV performance compared to potential performance. • PV system techno-economic performance reduces with the long term exposure or aging. • We observe fall in earned carbon credit and rise in cost/kWh as PV system ages

  2. Comparison of Turkey’s Geographical Regions in terms of Stand-Alone PV System Design and Cost Parameters

    Directory of Open Access Journals (Sweden)

    Nevzat Onat

    2017-01-01

    Full Text Available Stand-alone photovoltaic (SAPV systems are widely used in rural areas where there is no national grid or as a precaution against power outages. In this study, technical and economic analysis of a SAPV system was carried out using meteorological data for 75 province centers in seven geographical regions of Turkey. Obtained results for each province center were separated by geographical area. The averages of the centers for each region are taken as output. A calculation algorithm based on MsExcel has been established for these operations. The analyses made with the developed algorithm are repeated for five different scenarios that they cover periods of time when a constant strong load is active for all seasons (winter, spring, summer, and autumn and all year round. The developed algorithm calculates the life-cycle cost, the unit energy cost, the electrical capacity utilization rate, the amount of generated/excess energy per month, the initial investment/replacement, and operating and maintenance (O&M costs of each element. As a result, geographical regions of Turkey are compared in terms of these outputs graphically. Further investigations may include the sale of excess energy generated, small-scale PV system cost factors parallel to the grid, and the effects of government incentives.

  3. Freshman Sexual Attitudes and Behavior.

    Science.gov (United States)

    Nutt, Roberta L.; Sedlacek, William E.

    At the University of Maryland, 758 randomly selected incoming freshman students were administered an anonymous poll regarding their sexual attitudes and behavior. Results showed that the Maryland freshman generally resembled other U.S. college students in their sexual experience. Approximately half (52% of males, 46% of females) reported that they…

  4. Adult Degenerative Scoliosis with Spinal Stenosis Treated with Stand-Alone Cage via an Extreme Lateral Transpsoas Approach; a Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Arvind von Keudell

    2015-04-01

    Full Text Available We report the case of a 73-year-old female with severe degenerative scoliosis and back and leg pain that wassuccessfully treated with stand- alone cages via an extreme lateral transpsoas approach. This patient had declinedopen surgery and instrumentation due to her advanced age concerns about potential side effects.

  5. Stand-alone Inverter: Reviews, Models and Tests the exist system in Term of the Power Quality, and Suggestions to Design it

    Directory of Open Access Journals (Sweden)

    Ali Algaddafi

    2016-10-01

    Full Text Available Developments in power electronics have enabled the widespread application of Pulse Width Modulation (PWM inverters, notably for obtaining electricity from renewable systems. This paper critical review the previous studies in designing stand-alone inverter and modelling the inverter with two control loops to improve and provide a high-quality power of a stand-alone inverter. Multi-loop control techniques for a stand-alone inverter are utilised as the first loop is a capacitor current control to provide active damping and improve transient and steady state inverter performance. The capacitor current control is cheaper than inductor current control, where a small current sensing resistor is used. The second loop is the output voltage control that is used to improve the system performance and also control the output voltage. The power quality of the off-grid system is measured experimentally and compared with the grid power, showing power quality of off-grid system to be better than that of the grid. The suggestions and key findings to design the stand-alone inverter are given based in the reviewing of previous publications and from the literature’s point of view.

  6. Energetic and financial investigation of a stand-alone solar-thermal Organic Rankine Cycle power plant

    International Nuclear Information System (INIS)

    Tzivanidis, Christos; Bellos, Evangelos; Antonopoulos, Kimon A.

    2016-01-01

    Highlights: • A stand-alone solar driven Organic Rankine Cycle is optimized parametrically. • The system is optimized energetically and financially. • Nine working fluids are tested with cyclohexane to be the most suitable. • A collecting area of 25,000 m 2 parabolic trough collectors is the optimum solution. • The maximum IRR is 13.46% and the payback period is about 9 years. - Abstract: The use of solar thermal energy for electricity production is a clean and sustainable way to cover the increasing energy needs of our society. The most mature technology for capturing solar energy in high temperature levels is the parabolic trough collectors (PTC). In this study, an Organic Rankine Cycle (ORC) coupled with PTC is analyzed parametrically in order to be optimized financially and energetically. The first step is the thermodynamic investigation of the ORC by using various working fluids. The second step is the energetic and financial investigation of the total system which includes the solar field, the storage tank and the ORC module. By testing many combinations of collecting areas and storage tank volumes, finally cyclohexane proved to be the most suitable working fluid for producing 1 MW el with PTC. Specifically, in the optimum situation a solar field of 25,000 m 2 with storage tank of about 300 m 3 leads to a payback period of 9 years and to an internal rate of return (IRR) equal to 13.46%. Moreover, an economic comparison for different commercial collectors is presented, with Eurotrough ET-150 being the financially optimum solution for this case study.

  7. An adaptive artificial neural network model for sizing stand-alone photovoltaic systems: Application for isolated sites in Algeria

    International Nuclear Information System (INIS)

    Mellit, A.; Benghanem, M.; Hadj Arab, A.; Guessoum, G.

    2004-07-01

    In this paper we investigate, by using an adaptive Artificial Neural Network (ANN), in order to find a suitable model for sizing Stand-Alone Photovoltaic (SAPV) systems, based on a minimum of input data. This model combines Radial Basis Function (RBF) network and Infinite Impulse Response (IIR) filter in order to accelerate the convergence of the network. For the sizing of a photovoltaic (PV) system, we need to determine the optimal sizing coefficients (K PV , K B . These coefficients allow us to determine the number of solar panels and storage batteries necessary to satisfy a given consumption, especially in isolated sites where the global solar radiation data is not always available and which are considered the most important parameters for sizing a PV system. Obtained results by classical models (analytical, numerical, analytical- numerical, B-spline function) and new models like feed-forward (MLP), radial basis function (RBF), MLP-IIR and RBF-IIR have been compared with experimental sizing coefficients in order to illustrate the accuracy of the results of the new developed model. This model has been trained by using 200 known optimal sizing coefficients corresponding to 200 locations in Algeria. In this way, the adaptive model was trained to accept and even handle a number of unusual cases, the unknown validation sizing coefficients set produced very set accurate estimation and a correlation coefficient of 98% was obtained between the calculated and that estimated by the RBF-IIR model. This result indicates that the proposed method can be successfully used for the estimation of optimal sizing coefficients of SAPV systems for any locations in Algeria, but the methodology can be generalized using different locations over the world. (author)

  8. System dynamic model and charging control of lead-acid battery for stand-alone solar PV system

    KAUST Repository

    Huang, B.J.

    2010-05-01

    The lead-acid battery which is widely used in stand-alone solar system is easily damaged by a poor charging control which causes overcharging. The battery charging control is thus usually designed to stop charging after the overcharge point. This will reduce the storage energy capacity and reduce the service time in electricity supply. The design of charging control system however requires a good understanding of the system dynamic behaviour of the battery first. In the present study, a first-order system dynamics model of lead-acid battery at different operating points near the overcharge voltage was derived experimentally, from which a charging control system based on PI algorithm was developed using PWM charging technique. The feedback control system for battery charging after the overcharge point (14 V) was designed to compromise between the set-point response and the disturbance rejection. The experimental results show that the control system can suppress the battery voltage overshoot within 0.1 V when the solar irradiation is suddenly changed from 337 to 843 W/m2. A long-term outdoor test for a solar LED lighting system shows that the battery voltage never exceeded 14.1 V for the set point 14 V and the control system can prevent the battery from overcharging. The test result also indicates that the control system is able to increase the charged energy by 78%, as compared to the case that the charging stops after the overcharge point (14 V). © 2010 Elsevier Ltd. All rights reserved.

  9. Techno-economic analysis of stand-alone photovoltaic/wind/battery/hydrogen systems for very small-scale applications

    Directory of Open Access Journals (Sweden)

    Stojković Saša M.

    2016-01-01

    Full Text Available The paper presents the results of a technical and economic analysis of three stand-alone hybrid power systems based on renewable energy sources which supply a specific group of low-power consumers. This particular case includes measuring sensors and obstacle lights on a meteorological mast for wind measurements requiring an uninterrupted power supply in cold climate conditions. Although these low-power (100 W measuring sensors and obstacle lights use little energy, their energy consumption is not the same as the available solar energy obtained on a daily or seasonal basis. In the paper, complementarity of renewable energy sources was analysed, as well as one of short-term lead-acid battery-based storage and seasonal, hydrogen-based (electrolyser, H2 tank, and fuel cells storage. These relatively complex power systems were proposed earlier for high-power consumers only, while this study specifically highlights the role of the hydrogen system for supplying low-power consumers. The analysis employed a numerical simulation method using the HOMER software tool. The results of the analysis suggest that solar and wind-solar systems, which involve meteorological conditions as referred to in this paper, include a relatively large number of lead-acid batteries. Additionally, the analysis suggests that the use of hydrogen power systems for supplying low power-consumers is entirely justifiable, as it significantly reduces the number of batteries (two at minimum in this particular case. It was shown that the increase in costs induced by the hydrogen system is acceptable.

  10. Post-processing in cardiovascular computed tomography. Performance of a client server solution versus a stand-alone solution

    International Nuclear Information System (INIS)

    Luecke, C.; Foldyna, B.; Andres, C.; Grothoff, M.; Nitzsche, S.; Gutberlet, M.; Lehmkuhl, L.; Boehmer-Lasthaus, S.

    2014-01-01

    Purpose: To compare the performance of server-based (CSS) versus stand-alone post-processing software (ES) for the evaluation of cardiovascular CT examinations (cvCT) and to determine the crucial steps. Data of 40 patients (20 patients for coronary artery evaluation and 20 patients prior to transcatheter aortic valve implantation [TAVI]) were evaluated by 5 radiologists with CSS and ES. Data acquisition was performed using a dual-source 128-row CT unit (SOMATOM Definition Flash, Siemens, Erlangen, Germany) and a 64-row CT unit (Brilliance 64, Philips, Hamburg, Germany). The following workflow was evaluated: Data loading, aorta and coronary segmentation, curved multiplanar reconstruction (cMPR) and 3 D volume rendering technique (3D-VRT), measuring of coronary artery stenosis and planimetry of the aortic annulus. The time requirement and subjective quality for the workflow were evaluated. The coronary arteries as well as the TAVI data could be evaluated significantly faster with CSS (5.5 ± 2.9 min and 8.2 ± 4.0 min, respectively) than with ES (13.9 ± 5.2 min and 15.2 ± 10.9 min, respectively, p = 0.01). Segmentation of the aorta (CSS: 1.9 ± 2.0 min, ES: 3.7 ± 3.3 min), generating cMPR of coronaries (CSS: 0.5 ± 0.2 min, ES: 5.1 ± 2.6 min), aorta and iliac vessels (CSS: 0.5 ± 0.4 min and 0.4 ± 0.4 min, respectively, ES: 1.6 ± 0.7 min and 2.8 ± 3 min, respectively) could be performed significantly faster with CSS than with ES with higher quality of cMPR, measuring of coronary stenosis and 3D-VRT (p < 0.05). Evaluation of cvCT can be accomplished significantly faster and better with CSS than with ES. The segmentation remains the most time-consuming workflow step, so optimization of segmentation algorithms could improve performance even further.

  11. An efficient sizing method for a stand-alone PV system in terms of the observed block extremes

    International Nuclear Information System (INIS)

    Chen, Shin-Guang

    2012-01-01

    Highlights: ► A fast optimal sizing method under climate change. ► It provides the method of creating climate cycles for PV system applications. ► It proposes a new reliability indicator to denote the upper bound probability of a PV application. ► It presents a premiere economic optimization for such approach. ► It gives examples to illustrate the proposed approach. -- Abstract: This paper proposes a novel and fast sizing method under the constant daily load profile for sizing a stand-alone PV system. The term “efficient sizing” means that the approach did not use simulation but could get the result as good as those employing simulation. So, the sizing method is more efficient than the others. Traditionally, a typical day or a typical year’s solar irradiation profile is employed for the sizing task. However, facing the global warming crisis as well as the fact that no 2 years would have the same weather condition for a single site, this approach statistically models the trend of climate change year by year and put it into the sizing formula, so that the results are optimal for the current weather condition and for the future as well. Hence, the suitable size for the PV array and the number of batteries are obtained by purely computation. This is different from the traditional sizing curve method. Although the traditional sizing curve method were satisfactory in the normal cases, they might fail in the extreme climate condition. This paper concludes the behavior of the extreme climate for at least 20 years. So, the derived system may have statistical confidence for at least 20 years of operation. A new reliability index (Loss of Power Probability) in terms of Extreme Value Theory is introduced. LPP provides upper bound reliability for application and rich information for many extreme events. A technological and economical comparison among the traditional daily energy balance method, sizing curve method and this approach is conducted and shows the

  12. Post-processing in cardiovascular computed tomography: performance of a client server solution versus a stand-alone solution.

    Science.gov (United States)

    Lücke, C; Foldyna, B; Andres, C; Boehmer-Lasthaus, S; Grothoff, M; Nitzsche, S; Gutberlet, M; Lehmkuhl, L

    2014-12-01

    To compare the performance of server-based (CSS) versus stand-alone post-processing software (ES) for the evaluation of cardiovascular CT examinations (cvCT) and to determine the crucial steps. Data of 40 patients (20 patients for coronary artery evaluation and 20 patients prior to transcatheter aortic valve implantation [TAVI]) were evaluated by 5 radiologists with CSS and ES. Data acquisition was performed using a dual-source 128-row CT unit (SOMATOM Definition Flash, Siemens, Erlangen, Germany) and a 64-row CT unit (Brilliance 64, Philips, Hamburg, Germany). The following workflow was evaluated: Data loading, aorta and coronary segmentation, curved multiplanar reconstruction (cMPR) and 3 D volume rendering technique (3D-VRT), measuring of coronary artery stenosis and planimetry of the aortic annulus. The time requirement and subjective quality for the workflow were evaluated. The coronary arteries as well as the TAVI data could be evaluated significantly faster with CSS (5.5  ±  2.9  min and 8.2  ±  4.0  min, respectively) than with ES (13.9  ±  5.2  min and 15.2  ±  10.9  min, respectively, p ≤  0.01). Segmentation of the aorta (CSS: 1.9 ±  2.0  min, ES: 3.7  ±  3.3  min), generating cMPR of coronaries (CSS: 0.5  ±  0.2  min, ES: 5.1  ±  2.6  min), aorta and iliac vessels (CSS: 0.5  ±  0.4  min and 0.4  ±  0.4  min, respectively, ES: 1.6  ±  0.7  min and 2.8  ±  3  min, respectively) could be performed significantly faster with CSS than with ES with higher quality of cMPR, measuring of coronary stenosis and 3D-VRT (p < 0.05). Evaluation of cvCT can be accomplished significantly faster and better with CSS than with ES.  The segmentation remains the most time-consuming workflow step, so optimization of segmentation algorithms could improve performance even further. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Business Writing in Freshman English.

    Science.gov (United States)

    Larmouth, Donald W.

    1980-01-01

    Suggests incorporating business writing into a freshman English course. Outlines three writing and research assignments: a financial status memorandum, a management analysis report, and an evaluation of applicants for a position at a university. (TJ)

  14. A compact seven switches topology and reduced DC-link capacitor size for single-phase stand-alone PV system with hybrid energy storages

    DEFF Research Database (Denmark)

    Liu, Xiong; Wang, Peng; Loh, Poh Chiang

    2011-01-01

    Single-phase stand-alone PV system is suitable for household applications in remote area. Hybrid battery/ultra-capacitor energy storage can reduce charge and discharge cycles and avoid deep discharges of battery. This paper proposes a compact seven switches structure for stand-alone PV system......-order harmonic current caused by single-phase inverter. In the proposed compact topology, a small size DC-link capacitor can achieve the same function through charging/discharging control of ultra-capacitor to mitigate second-order ripple current. Simulation results are provided to validate the effectiveness......, which otherwise needs nine switches configuration, inclusive of one switch for boost converter, four switches for single-phase inverter and four switches for two DC/DC converters of battery and ultra-capacitor. It is well-known that a bulky DC-link capacitor is always required to absorb second...

  15. Is Stand-Alone Anterior Lumbar Interbody Fusion a Safe and Efficacious Treatment for Isthmic Spondylolisthesis of L5-S1?

    OpenAIRE

    Viglione, Luke L.; Chamoli, Uphar; Diwan, Ashish D.

    2017-01-01

    Study Design: A systematic review. Objective: The objective of this study was to determine the safety and efficacy of stand-alone anterior lumbar interbody fusion (sa-ALIF) for the treatment of symptomatic isthmic spondylolisthesis of L5-S1 by assessing the level of available clinical and radiographic evidence. Methods: A systematic review utilizing Medline, Embase, and Scopus online databases was undertaken. Clinical, radiographic, and adverse outcome data were extracted for the relevant ist...

  16. Standing with electrical stimulation and splinting is no better than standing alone for management of ankle plantarflexion contractures in people with traumatic brain injury: a randomised trial

    Directory of Open Access Journals (Sweden)

    Joan Leung

    2014-12-01

    Full Text Available Question: Is a combination of standing, electrical stimulation and splinting more effective than standing alone for the management of ankle contractures after severe brain injury? Design: A multi-centre randomised trial with concealed allocation, assessor blinding and intention-to-treat analysis. Participants: Thirty-six adults with severe traumatic brain injury and ankle plantarflexion contractures. Intervention: All participants underwent a 6-week program. The experimental group received tilt table standing, electrical stimulation and ankle splinting. The control group received tilt table standing alone. Outcome measures: The primary outcome was passive ankle dorsiflexion with a 12 Nm torque. Secondary outcomes included: passive dorsiflexion with lower torques (3, 5, 7 and 9 Nm; spasticity; the walking item of the Functional Independence Measure; walking speed; global perceived effect of treatment; and perceived treatment credibility. Outcome measures were taken at baseline (Week 0, end of intervention (Week 6, and follow-up (Week 10. Results: The mean between-group differences (95% CI for passive ankle dorsiflexion at Week 6 and Week 10 were –3 degrees (–8 to 2 and –1 degrees (–6 to 4, respectively, in favour of the control group. There was a small mean reduction of 1 point in spasticity at Week 6 (95% CI 0.1 to 1.8 in favour of the experimental group, but this effect disappeared at Week 10. There were no differences for other secondary outcome measures except the physiotherapists’ perceived treatment credibility. Conclusion: Tilt table standing with electrical stimulation and splinting is not better than tilt table standing alone for the management of ankle contractures after severe brain injury. Trial registration: ACTRN12608000637347. [Leung J, Harvey LA, Moseley AM, Whiteside B, Simpson M, Stroud K (2014 Standing with electrical stimulation and splinting is no better than standing alone for management of ankle plantarflexion

  17. A comparative sizing analysis of a renewable energy supplied stand-alone house considering both demand side and source side dynamics

    International Nuclear Information System (INIS)

    Elma, Onur; Selamogullari, Ugur Savas

    2012-01-01

    Highlights: ► Backup sizing analyses for PV–Wind energy supplied stand-alone house are completed. ► Source and demand side dynamics are considered for the first time in backup sizing. ► Backup size is reduced by 10% compared to backup size found with hourly values. ► The importance of data resolution on sizing study in such systems is shown. -- Abstract: Solar and wind energy use to supply the electrical demand of a stand-alone residential house is investigated. Combining solar and wind energy sources provide more reliable power source for stand-alone applications since they complement each other. Backup units (battery/supercapacitor) are also needed for uninterrupted energy. For a proper backup sizing in such systems, high resolution load data, wind speed and solar radiation data must be used as compared to the use of hourly averaged data found in literature. In this study, high resolution data on both load side and source side are collected experimentally. Then, collected data used as input to system simulations in Matlab/Simulink for sizing the backup in the considered hybrid power system. Backup state of the charge (SOC) is used as decision criteria. It is shown that, when load and source dynamics are considered, approximately 10% less backup size is required compared to backup size found with hourly averaged values. The study shows the importance of data resolution on backup sizing in such systems and could be a guide for renewable energy system designers.

  18. Supervisory control applied to stand-alone photovoltaic systems based on multi string topology; Controle supervisorio aplicado a sistemas fotovoltaicos autonomos com topologia multi string

    Energy Technology Data Exchange (ETDEWEB)

    Candido, Diogo Brum

    2010-07-01

    This master thesis analyses and implements a stand-alone photovoltaic system based on decentralized 'Multi String' topology. The proposed system is composed of a set of DC-DC converters linked to the PV arrays of panels, a bidirectional converter to perform the control of the charge/discharge process of the battery bank and ensure the specifications of DC link and a full-bridge inverter that feed the AC loads. Therefore, all operation modes that the stand-alone PV system can work are presented and analyzed. As the chief aim is to ensure the energy balance of the stand-alone PV system, are presented independents control loops for each converter of the PV system and a propose of a supervisory control that, based on information about the conditions of the DC link and the bank of batteries, defines each operation mode should be active, in order to maximize the power extracted from the PV arrays, the life cycle of the battery bank and ensuring the uninterrupted feeding of energy to the loads. Finally, simulation and experimental results validate the operation of the proposed system under different load and solar radiation conditions. (author)

  19. Anterior cervical discectomy and fusion using a stand-alone polyetheretherketone cage packed with local autobone : assessment of bone fusion and subsidence.

    Science.gov (United States)

    Park, Jeong-Ill; Cho, Dae-Chul; Kim, Kyoung-Tae; Sung, Joo-Kyung

    2013-09-01

    It remains debatable whether cervical spine fusion cages should be filled with any kind of bone or bone substitute. Cortical and subcortical bone from the anterior and posterior osteophytes of the segment could be used to fill the cage. The purposes of the present study are to evaluate the clinical outcomes and radiological outcomes including bone fusion and subsidence that occurred after anterior cervical discectomy and fusion using a stand-alone cage packed with local autobone graft. Thirty-one patients who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage packed with local autobone graft from July 2009 to december 2011 were enrolled in this study. Bone fusion was assessed by cervical plain radiographs and computed tomographic scan. Nonunion was evaluated according to the absence of bony bridge on computed tomographic scan. Subsidence was defined as a ≥2 mm decrease of the interbody height at the final follow-up compared to that measured at the immediate postoperative period. Subsidence was observed in 7 patients (22.6%). Of 7 patients with subsidence greater 2 mm, nonunion was developed in 3. Three patients with subsidence greater 2 mm were related with endplate damage during intraoperative endplate preparation. Solid bone fusion was achieved in 28 out of 31 patients (90.3%). With proper patient selection and careful endplate preparation, anterior cervical discectomy and fusion (ACDF) using a stand-alone PEEK cage packed with local autobone graft could be a good alternative to the standard ACDF techniques with plating.

  20. Fracture of the L-4 vertebral body after use of a stand-alone interbody fusion device in degenerative spondylolisthesis for anterior L3-4 fixation.

    Science.gov (United States)

    Kwon, Yoon-Kwang; Jang, Ju-Hee; Lee, Choon-Dae; Lee, Sang-Ho

    2014-06-01

    Many studies attest to the excellent results achieved using anterior lumbar interbody fusion (ALIF) for degenerative spondylolisthesis. The purpose of this report is to document a rare instance of L-4 vertebral body fracture following use of a stand-alone interbody fusion device for L3-4 ALIF. The patient, a 55-year-old man, had suffered intractable pain of the back, right buttock, and left leg for several weeks. Initial radiographs showed Grade I degenerative spondylolisthesis, with instability in the sagittal plane (upon 15° rotation) and stenosis of central and both lateral recesses at the L3-4 level. Anterior lumbar interbody fusion of the affected vertebrae was subsequently conducted using a stand-alone cage/plate system. Postoperatively, the severity of spondylolisthesis diminished, with resolution of symptoms. However, the patient returned 2 months later with both leg weakness and back pain. Plain radiographs and CT indicated device failure due to anterior fracture of the L-4 vertebral body, and the spondylolisthesis had recurred. At this point, bilateral facetectomies were performed, with reduction/fixation of L3-4 by pedicle screws. Again, degenerative spondylolisthesis improved postsurgically and symptoms eased, with eventual healing of the vertebral body fracture. This report documents a rare instance of L-4 vertebral body fracture following use of a stand-alone device for ALIF at L3-4, likely as a consequence of angular instability in degenerative spondylolisthesis. Under such conditions, additional pedicle screw fixation is advised.

  1. Performance of a small stand alone photovoltaic-wind system at El Oyameyo D.F., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Juarez, A.; Campos, J. [Centro de Investigacion en Energia, UNAM, Mexico, D. F. (Mexico); Tiburcio Silver, A. [Instituto Tecnologico de Toluca-Division de Posgrado, Toluca (Mexico)

    1997-12-31

    El Oyameyo, is an ecological site located to the South-West of the Topilejo town, D.F., 19 degree 25` North latitude, 99 degree 5` West longitude and at an altitude of 3100 m. At present, there are 10 families living at this place. They have energy generators to produce their own electricity by means of solar or wind energy using photovoltaic (PV) technology and eolic systems, respectively. There are three different configurations of energy generators: DC regulated PV systems, AC regulated PV systems and one PV-Wind hybrid system. The electrical power installed for the stand alone PV systems are from 48 W-p up to 768 W-p range. Among these, there are 4 PV systems that are configurated in DC regulated systems, and other 6 are AC regulated systems. All these systems use lead-acid battery (scaled or vented) banks to store the energy produced daily by the systems. The PV-Wind hybrid system in formed, at present, by a 5.0 kW wind generator, a PV array of 768 W-p, a 37.8 kW-h storage battery bank and a 5.0 kW DC/AC inverter. In this work, we report the electricity generated, load pattern and overall system performance of the photovoltaic-wind hybrid system. The technical characteristics, energy test on the hybrid system and the experience obtained from energy handling and system maintenance for all the systems are presented. We found that all the systems had shown good performance and users` satisfaction. [Espanol] El Oyameyo es un lugar ecologico localizado al Sur-Oeste del pueblo de Topilejo, D. F., 19 grados 25` de latitud Norte 99 grados 5` de longitud Oeste y a una altitud de 3100m. Actualmente hay 10 familias viviendo en este lugar. Tienen generadores de energia para producir su propia electricidad mediante la energia solar y la del viento usando sistemas fotovoltaicos (FV) y sistemas eolicos, respectivamente. Hay tres diferentes configuraciones de generadores de energia: sistemas fotovoltaicos de CD regulados, sistemas fotovoltaicos de CA regulados y un sistema

  2. Outcomes of contemporary use of rectangular titanium stand-alone cages in anterior cervical discectomy and fusion: cage subsidence and cervical alignment.

    Science.gov (United States)

    Yamagata, Toru; Takami, Toshihiro; Uda, Takehiro; Ikeda, Hidetoshi; Nagata, Takashi; Sakamoto, Shinichi; Tsuyuguchi, Naohiro; Ohata, Kenji

    2012-12-01

    Cervical intervertebral disc replacement using a rectangular titanium stand-alone cage has become a standard procedure for anterior cervical discectomy and fusion (ACDF). We examined outcomes resulting from the contemporary use of rectangular titanium stand-alone cages for ACDF, particularly focusing on cage subsidence and subsequent kyphotic malalignment. Patient data were collected prospectively, and a total of 47 consecutive patients who underwent periodic follow-up of at least 1 year's duration after ACDF were studied retrospectively. Sixty-three rectangular titanium cages were implanted during 31 1-level and 16 2-level procedures. None of the patients developed surgery-related complications (including cage displacement or extrusion). Mean Neurosurgical Cervical Spine Scale scores were significantly improved at 1 year after surgery. Twelve of the 63 inserted cages (19.0%) were found to have cage subsidence, occurring in 11 of 47 patients (23.4%). There was no significant difference in functional recovery between patients with and without cage subsidence. Logistic regression analysis indicated that fusion level, cage size and cage position were significantly related to cage subsidence. The distraction ratio among patients with cage subsidence was significantly higher than that among patients without cage subsidence. Cage subsidence resulted in early deterioration of local angle and total alignment of the cervical spine. Although a longer follow-up is warranted, a good surgical outcome with negligible complications appears to justify the use of rectangular titanium stand-alone cages in 1- and 2-level ACDF. Excessive distraction at the fusion level should be avoided, and cage position should be adjusted to the anterior vertical line. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Fusion and subsidence rate of stand alone anterior lumbar interbody fusion using PEEK cage with recombinant human bone morphogenetic protein-2.

    Science.gov (United States)

    Behrbalk, Eyal; Uri, Ofir; Parks, Ruth M; Musson, Rachel; Soh, Reuben Chee Cheong; Boszczyk, Bronek Maximilian

    2013-12-01

    Anterior lumbar interbody fusion (ALIF) is an established treatment for structural instability associated with symptomatic disk degeneration (SDD). Stand-alone ALIF offers many advantages, however, it may increase the risk of non-union. Recombinant human bone morphogenetic protein-2 (BMP-2) may enhance fusion rate but is associated with postoperative complication. The optimal dose of BMP-2 remains unclear. This study assessed the fusion and subsidence rates of stand-alone ALIF using the SynFix-LR interbody cage with 6 ml/level of BMP-2. Thirty-two ALIF procedures were performed by a single surgeon in 25 patients. Twenty-five procedures were performed for SDD without spondylolisthesis (SDD group) and seven procedures were performed for SDD with grade-I olisthesis (SDD-olisthesis group). Patients were followed-up for a mean of 17 ± 6 months. Solid fusion was achieved in 29 cases (90.6 %) within 6 months postoperatively. Five cases of implant subsidence were observed (16 %). Four of these occurred in the SDD-olisthesis group and one occurred in the SDD group (57 % vs. 4 % respectively; p = 0.004). Three cases of subsidence failed to fuse and required revision. The body mass index of patients with olisthesis who developed subsidence was higher than those who did not develop subsidence (29 ± 2.6 vs. 22 ± 6.5 respectively; p = 0.04). No BMP-2 related complications occurred. The overall fusion rate of stand-alone ALIF using the SynFix-LR system with BMP-2 was 90.6 %, comparable with other published series. No BMP-2 related complication occurred at a dose of 6 mg/level. Degenerative spondylolisthesis and obesity seemed to increase the rate of implant subsidence, and thus we believe that adding posterior fusion for these cases should be considered.

  4. Segmental kyphosis after cervical interbody fusion with stand-alone polyetheretherketone (PEEK) cages: a comparative study on 2 different PEEK cages.

    Science.gov (United States)

    Kim, Chi Heon; Chung, Chun Kee; Jahng, Tae-Ahn; Park, Sung Bae; Sohn, Seil; Lee, Sungjoon

    2015-02-01

    Retrospective comparative study. Two polyetheretherketone (PEEK) cages of different designs were compared in terms of the postoperative segmental kyphosis after anterior cervical discectomy and fusion. Segmental kyphosis occasionally occurs after the use of a stand-alone cage for anterior cervical discectomy and fusion. Although PEEK material seems to have less risk of segmental kyphosis compared with other materials, the occurrence of segmental kyphosis for PEEK cages has been reported to be from 0% to 29%. There have been a few reports that addressed the issue of PEEK cage design. A total of 41 consecutive patients who underwent single-level anterior discectomy and fusion with a stand-alone cage were included. Either a round tube-type (Solis; 18 patients, S-group) or a trapezoidal tube-type (MC+; 23 patients, M-group) cage was used. The contact area between the cage and the vertebral body is larger in MC+ than in Solis, and anchoring pins were present in the Solis cage. The effect of the cage type on the segmental angle (SA) (lordosis vs. kyphosis) at postoperative month 24 was analyzed. Preoperatively, segmental lordosis was present in 12/18 S-group and 16/23 M-group patients (P=0.84). The SA was more lordotic than the preoperative angle in both groups just after surgery, with no difference between groups (P=0.39). At 24 months, segmental lordosis was observed in 9/18 S-group and 20/23 M-group patients (P=0.01). The patients in M-group were 7.83 times more likely than patients in S-group (P=0.04; odds ratio, 7.83; 95% confidence interval, 1.09-56.28) not to develop segmental kyphosis. The design of the PEEK cage used may influence the SA, and this association needs to be considered when using stand-alone PEEK cages.

  5. Clinician's perspectives of the relocation of a regional child and adolescent mental health service from co-located to stand alone premises.

    Science.gov (United States)

    Francis, K J; Boyd, C P; Sewell, J; Nurse, S

    2008-01-01

    Australia's National Mental Health Strategy's statement of rights and responsibilities states that children and adolescents admitted to a mental health facility or community program have the right to be separated from adult patients and provided with programs suited to their developmental needs. However, in rural Australia, where a lack of healthcare services, financial constraints, greater service delivery areas and fewer mental healthcare specialists represent the norm, Child and Adolescent Mental Health Services (CAMHS) are sometimes co-located with adult mental health services. The aim of the present study was to evaluate the impact of a recent relocation of a regional CAMHS in Victoria from co-located to stand alone premises. Six CAMHS clinicians who had experienced service delivery at a co-located setting and the current stand-alone CAMHS setting were interviewed about their perceptions of the impact of the relocation on service delivery. An exploratory interviewing methodology was utilized due to the lack of previous research in this area. Interview data were transcribed and analysed according to interpretative phenomenological analysis techniques. Findings indicated a perception that the relocation was positive for clients due to the family-friendly environment at the new setting and separation of CAMHS from adult psychiatric services. However, the impact of the relocation on clinicians was marked by a perceived loss of social capital from adult psychiatric service clinicians. These results provide increased understanding of the effects of service relocation and the influence of co-located versus stand-alone settings on mental health service delivery - an area where little prior research exists.

  6. Single anterior cervical discectomy and fusion (ACDF) using self- locking stand-alone polyetheretherketone (PEEK) cage: evaluation of pain and health-related quality of life.

    Science.gov (United States)

    Kapetanakis, Stylianos; Thomaidis, Tryfon; Charitoudis, George; Pavlidis, Pavlos; Theodosiadis, Panagiotis; Gkasdaris, Grigorios

    2017-09-01

    Anterior cervical discectomy and fusion (ACDF) constitutes the conventional treatment of cervical disc herniation due to degenerative disc disease (DDD). ACDF with plating presents a variety of complications postoperatively and stand-alone cages are thought to be a promising alternative. The aim of this study was firstly, to analyze prospectively collected data from a sample of patients treated with single ACDF using C-Plus self-locking stand-alone PEEK cage system, without the use of plates or screws, in order to evaluate pain levels of patients, utilizing Neck and Arm Pain scale as an expression of visual analogue scale (VAS). Secondly, we aimed to evaluate health-related quality of life, via the short-form 36 (SF-36) and Neck Disability Index (NDI). Thirty-six patients (19 male and 17 female) with mean age 49.6±7 years old who underwent successful single ACDF using self-locking stand-alone PEEK cage for symptomatic cervical DDD were selected for the study. Neck and Arm pain, as well as SF-36 and NDI were estimated preoperatively and 1, 3, 6, and 12 months postoperatively. Patients underwent preoperative and postoperative clinical, neurological and radiological evaluation. The clinical and radiological outcomes were satisfactory after a minimum 1-year follow-up. All results were statistically important (P<0.05), excluding improvement in NDI measured between 6 and 12 months. SF-36, Neck Pain, as well as Arm Pain featured gradual and constant improvement during follow-up, with best scores presenting at 12 months after surgery, while NDI reached its best at 6 months postoperatively. Generally, all scores showed improvement postoperatively during the different phases of the follow-up. Subsequently, ACDF using C-Plus cervical cage constitutes an effective method for cervical disc herniation treatment, in terms of postoperative improvement on pain levels and health-related quality of life and a safe alternative to the conventional method of treatment for cervical DDD.

  7. Techno-economic assessment of FT unit for synthetic diesel production in existing stand-alone biomass gasification plant using process simulation tool

    DEFF Research Database (Denmark)

    Hunpinyo, Piyapong; Narataruksa, Phavanee; Tungkamani, Sabaithip

    2014-01-01

    such as Fischer-Tropsch (FT) diesel. The embedding of the FT plant into the stand-alone based on power mode plants for production of a synthetic fuel is a promising practice, which requires an extensive adaptation of conventional techniques to the special chemical needs found in a gasified biomass. Because...... there are currently no plans to engage the FT process in Thailand, the authors have targeted that this work focus on improving the FT configurations in existing biomass gasification facilities (10 MWth). A process simulation model for calculating extended unit operations in a demonstrative context is designed...

  8. Effect of State Feedback Coupling and System Delays on the Transient Performance of Stand-Alone VSI with LC Output Filter

    DEFF Research Database (Denmark)

    Federico, de Bosio; de Sousa Ribeiro, Luiz Antonio; Freijedo Fernandez, Francisco Daniel

    2016-01-01

    The influence of state feedback coupling in the dynamics performance of power converters for stand-alone microgrids is investigated. Computation and PWM delays are the main factors that limit the achievable bandwidth of current regulators in digital implementations. In particular, the performance...... provided. A proportional resonant voltage controller is designed according to Nyquist criterion taking into account application requirements. For this purpose, a mathematical expression based on root locus analysis is proposed to find the minimum value of the fundamental resonant gain. Experimental tests...

  9. DCE-MRI of the breast in a stand-alone setting outside a complementary strategy - results of the TK-study

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Clemens G.; Krammer, J.; Wasser, K.; Schoenberg, S.O. [University Medical Centre Mannheim, Medical Faculty Mannheim-University of Heidelberg, Institute of Clinical Radiology and Nuclear Medicine, Mannheim (Germany); Reich, C.; Kaiser, W.A. [Friedrich-Schiller-University Hospital Jena, Institute of Diagnostic and Interventional Radiology I, Jena (Germany); Dietzel, M. [Friedrich-Alexander-University Hospital Erlangen-Nuernberg, Department of Neuroradiology, Erlangen (Germany); Baltzer, P.A.T. [Medical University Vienna, Institute of Radiology and Nuclear Medicine, Vienna (Austria)

    2015-06-01

    To evaluate the accuracy of MRI of the breast (DCE-MRI) in a stand-alone setting with extended indications. According to the inclusion criteria, breast specialists were invited to refer patients to our institution for DCE-MRI. Depending on the MR findings, patients received either a follow-up or biopsy. Between 04/2006 and 12/2011 a consecutive total of 1,488 women were prospectively examined. Of 1,488 included patients, 393 patients were lost to follow-up, 1,095 patients were evaluated. 124 patients were diagnosed with malignancy by DCE-MRI (76 TP, 48 FP, 971 TN, 0 FN cases). Positive cases were confirmed by histology, negative cases by MR follow-ups or patient questionnaires over the next 5 years in 1,737 cases (sensitivity 100 %; specificity 95.2 %; PPV 61.3 %; NPV 100 %; accuracy 95.5 %). For invasive cancers only (DCIS excluded), the results were 63 TP; 27 FP; 971 TP and 0 FN (sensitivity 100 %; specificity 97.2 %; PPV 70 %; NPV 100 %; accuracy 97.5 %). The DCE-MRI indications tested imply that negative results in DCE-MRI reliably exclude cancer. The results were achieved in a stand-alone setting (single modality diagnosis). However, these results are strongly dependent on reader experience and adequate technical standards as prerequisites for optimal diagnoses. (orig.)

  10. Risk factors for subsidence in anterior cervical fusion with stand-alone polyetheretherketone (PEEK) cages: a review of 82 cases and 182 levels.

    Science.gov (United States)

    Kao, Ting-Hsien; Wu, Chen-Hao; Chou, Yu-Ching; Chen, Hsien-Te; Chen, Wen-Hsien; Tsou, Hsi-Kai

    2014-10-01

    To determine risk factors for subsidence in patients treated with anterior cervical discectomy and fusion (ACDF) and stand-alone polyetheretherketone (PEEK) cages. Records of patients with degenerative spondylosis or traumatic disc herniation resulting in radiculopathy or myelopathy between C2 and C7 who underwent ACDF with stand-alone PEEK cages were retrospectively reviewed. Cages were filled with autogenous cancellous bone harvested from iliac crest or hydroxyapatite. Subsidence was defined as a decrease of 3 mm or more of anterior or posterior disc height from that measured on the postoperative radiograph. Eighty-two patients (32 males, 50 females; 182 treatment levels) were included in the analysis. Most patients had 1-2 treatment levels (62.2 %), and 37.8 % had 3-4 treatment levels. Treatment levels were from C2-7. Of the 82 patients, cage subsidence occurred in 31 patients, and at 39 treatment levels. Multivariable analysis showed that subsidence was more likely to occur in patients with more than two treatment levels, and more likely to occur at treatment levels C5-7 than at levels C2-5. Subsidence was not associated with postoperative alignment change but associated with more disc height change (relatively oversized cage). Subsidence is associated with a greater number of treatment levels, treatment at C5-7 and relatively oversized cage use.

  11. [Biomechanicsl evaluation of a stand-alone interbody fusion cage based on porous TiO2/glass-ceramic on the human cervical spine].

    Science.gov (United States)

    Korinth, M C; Moersch, S; Ragoss, C; Schopphoff, E

    2003-12-01

    Recently, there has been a rapid increase in the use of cervical spine interbody fusion cages, differing in design and biomaterial used, in competition to autologous iliac bone graft and bone cement (PMMA). Limited biomechanical differences in primary stability, as well as advantages and disadvantages of each cage or material have been investigated in studies, using an in vitro human cervical spine model. 20 human cervical spine specimens were tested after fusion with either a cubical stand-alone interbody fusion cage manufactured from a new porous TiO2/glass composite (Ecopore) or PMMA after discectomy. Non-destructive biomechanical testing was performed, including flexion/extension and lateral bending using a spine testing apparatus. Three-dimensional segmental range of motion (ROM) was evaluated using an ultrasound measurement system. ROM increased more in flexion/extension and lateral bending after PMMA fusion (26.5%/36.1%), then after implantation of the Ecopore-cage (8.1%/7.8%). In this first biomechanical in vitro examination of a new porous ceramic bone replacement material a) the feasibility and reproducibility of biomechanical cadaveric cervical examination and its applicability was demonstrated, b) the stability of the ceramic cage as a stand alone interbody cage was confirmed in vitro, and c) basic information and knowledge for our intended biomechanical and histological in vivo testing, after implantation of Ecopore in cervical sheep spines, were obtained.

  12. Clinical and radiological outcomes after stand-alone ALIF for single L5-S1 degenerative discopathy using a PEEK cage filled with hydroxyapatite nanoparticles without bone graft.

    Science.gov (United States)

    Norotte, Gilles; Barrios, Carlos

    2018-05-01

    Recent improvements in cage designs with integral fixation and screw attachments have made stand-alone ALIF a viable option with several possible advantages. The aim of this study was to confirm the efficacy and safety of a PEEK cage filled with hydroxyapatite nanoparticles without adding a bone graft for stand-alone ALIF in the treatment of L5-S1 isolated degenerative disc discopathy (DDD). Sixty-five patients who required surgery for DDD were evaluated. Clinical outcome evaluations included back and leg pain (VAS), disability (Oswestry Disability Index), and patient satisfaction (Macnab's criteria). Radiological outcomes include the assessment of disc height, the L5-S1 intervertebral disc angle, and anterior intervertebral fusion through standard and functional sagittal X-rays of the lumbar spine. Clinical and radiological measurements were assessed 2, 6, 12, and 24 months after surgery. Clinical outcomes improved progressively and stabilized from 12- to 24-month follow-up. Final postoperative ODI scores showed a notable improvement (95%CI = 36.1-48.9 points; p < .001). Similarly, 24-month postoperative VAS scores revealed a significant decrease in pain (95%CI = 5.4-6.2; p < .001). The fusion rate was 95.4%. Anterior disc height was restored from 4.1 ± 3.2 mm at baseline to 9.5 ± 1.6 mm in the immediate postoperative period (p < .001). A small collapse (17.9%) of the disc height was detected from the 2- and 24-month follow-ups. Cage subsidence (more than 3 mm collapse) was detected in 4 cases (6.2%) and was related to cage size (more than 11 mm height; P < .05). There were no serious bone substitute-related adverse events and no revision surgeries. Stand-alone anterior lumbar interbody fusion using hydroxyapatite nanoparticles without an autologous bone graft is an effective and safe treatment option for L5-S1 degenerative pathology. Clinical outcomes were very satisfactory with a high fusion rate. Copyright © 2018

  13. Solution and crystal structure of BA42, a protein from the Antarctic bacterium Bizionia argentinensis comprised of a stand-alone TPM domain.

    Science.gov (United States)

    Aran, Martin; Smal, Clara; Pellizza, Leonardo; Gallo, Mariana; Otero, Lisandro H; Klinke, Sebastián; Goldbaum, Fernando A; Ithurralde, Esteban R; Bercovich, Andrés; Mac Cormack, Walter P; Turjanski, Adrián G; Cicero, Daniel O

    2014-11-01

    The structure of the BA42 protein belonging to the Antarctic flavobacterium Bizionia argentinensis was determined by nuclear magnetic resonance and X-ray crystallography. This is the first structure of a member of the PF04536 family comprised of a stand-alone TPM domain. The structure reveals a new topological variant of the four β-strands constituting the central β-sheet of the αβα architecture and a double metal binding site stabilizing a pair of crossing loops, not observed in previous structures of proteins belonging to this family. BA42 shows differences in structure and dynamics in the presence or absence of bound metals. The affinity for divalent metal ions is close to that observed in proteins that modulate their activity as a function of metal concentration, anticipating a possible role for BA42. © 2014 Wiley Periodicals, Inc.

  14. Grid parity analysis of stand-alone hybrid microgrids: A comparative study of Germany, Pakistan, South Africa and the United States

    Science.gov (United States)

    Siddiqui, Jawad M.

    Grid parity for alternative energy resources occurs when the cost of electricity generated from the source is lower than or equal to the purchasing price of power from the electricity grid. This thesis aims to quantitatively analyze the evolution of hybrid stand-alone microgrids in the US, Germany, Pakistan and South Africa to determine grid parity for a solar PV/Diesel/Battery hybrid system. The Energy System Model (ESM) and NREL's Hybrid Optimization of Multiple Energy Resources (HOMER) software are used to simulate the microgrid operation and determine a Levelized Cost of Electricity (LCOE) figure for each location. This cost per kWh is then compared with two distinct estimates of future retail electricity prices at each location to determine grid parity points. Analysis results reveal that future estimates of LCOE for such hybrid stand-alone microgrids range within the 35-55 cents/kWh over the 25 year study period. Grid parity occurs earlier in locations with higher power prices or unreliable grids. For Pakistan grid parity is already here, while Germany hits parity between the years 2023-2029. Results for South Africa suggest a parity time range of the years 2040-2045. In the US, places with low grid prices do not hit parity during the study period. Sensitivity analysis results reveal the significant impact of financing and the cost of capital on these grid parity points, particularly in developing markets of Pakistan and South Africa. Overall, the study helps conclude that variations in energy markets may determine the fate of emerging energy technologies like microgrids. However, policy interventions have a significant impact on the final outcome, such as the grid parity in this case. Measures such as eliminating uncertainty in policies and improving financing can help these grids overcome barriers in developing economies, where they may find a greater use much earlier in time.

  15. PR2ALIGN: a stand-alone software program and a web-server for protein sequence alignment using weighted biochemical properties of amino acids.

    Science.gov (United States)

    Kuznetsov, Igor B; McDuffie, Michael

    2015-05-07

    Alignment of amino acid sequences is the main sequence comparison method used in computational molecular biology. The selection of the amino acid substitution matrix best suitable for a given alignment problem is one of the most important decisions the user has to make. In a conventional amino acid substitution matrix all elements are fixed and their values cannot be easily adjusted. Moreover, most existing amino acid substitution matrices account for the average (dis)similarities between amino acid types and do not distinguish the contribution of a specific biochemical property to these (dis)similarities. PR2ALIGN is a stand-alone software program and a web-server that provide the functionality for implementing flexible user-specified alignment scoring functions and aligning pairs of amino acid sequences based on the comparison of the profiles of biochemical properties of these sequences. Unlike the conventional sequence alignment methods that use 20x20 fixed amino acid substitution matrices, PR2ALIGN uses a set of weighted biochemical properties of amino acids to measure the distance between pairs of aligned residues and to find an optimal minimal distance global alignment. The user can provide any number of amino acid properties and specify a weight for each property. The higher the weight for a given property, the more this property affects the final alignment. We show that in many cases the approach implemented in PR2ALIGN produces better quality pair-wise alignments than the conventional matrix-based approach. PR2ALIGN will be helpful for researchers who wish to align amino acid sequences by using flexible user-specified alignment scoring functions based on the biochemical properties of amino acids instead of the amino acid substitution matrix. To the best of the authors' knowledge, there are no existing stand-alone software programs or web-servers analogous to PR2ALIGN. The software is freely available from http://pr2align.rit.albany.edu.

  16. Effects of ozone as a stand-alone and coagulation-aid treatment on the reduction of trihalomethanes precursors from high DOC and hardness water.

    Science.gov (United States)

    Sadrnourmohamadi, Mehrnaz; Gorczyca, Beata

    2015-04-15

    This study investigates the effect of ozone as a stand-alone and coagulation aid on the removal of dissolved organic carbon (DOC) from the water with a high level of DOC (13.8 mgL(-1)) and calcium hardness (270 mgL(-1)) CaCO3. Natural water collected from the Assiniboine River (Manitoba, Canada) was used in this study. Effectiveness of ozone treatment was evaluated by measurement of DOC, DOC fractions, UV254, and trihalomethane formation potential (THMFP). Additionally, zeta potential and dissolved calcium concentration were measured to discern the mechanism of ozone reactions. Results indicated that 0.8 mg O3/mg DOC ozone stand-alone can cause up to 86% UV254 reduction and up to 27% DOC reduction. DOC fractionation results showed that ozone can change the composition of DOC in the water samples, converting the hydrophobic fractions into hydrophilic ones and resulting in the reduction of THMFP. Also, ozone caused a decrease in particle stability and dissolved calcium concentration. These simultaneous ozonation effects caused improved water flocculation and enhanced removal of DOC. This resulted in reduction of the coagulant dosage when ozone doses higher than 0.2 mg O3/mg DOC were applied prior to coagulation with ferric sulfate. Also, pre-ozonation-coagulation process achieved preferential THMFP removal for all of the ozone doses tested (0-0.8 mg O3/mg DOC), leading to a lower specific THMFP in pre-ozonated-coagulated waters than in the corresponding ozonated waters. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Analysis of the impact of batteries behaviour on stand-alone photovoltaic systems; Analise do impacto do comportamento de baterias em sistemas fotovoltaicos autonomos

    Energy Technology Data Exchange (ETDEWEB)

    Vera, Luis Horacio

    2009-08-15

    Stand-alone photovoltaic systems are a suitable alternative for rural electrification. However, there are still problems to be solved, mainly related to the system design and the technical quality of the equipment and facilities, which impacts the systems reliability. To determine the factors that affect the reliability of these systems it were studied the most common configurations and associated failures. The Laboratory experimental research, together with an extensive literature review, show the basic technical problems that occur to each of the elements of the installation and the dependence between them. These studies have shown that the storage the system, considering system reliability and economy, is the weakest element due to the decrease of their storage capacity. This led to consider the storage systems as the focus of this study and, through the analysis of their behavior, to develop a procedure to size systems with high reliability, lower cost and appropriate configuration. The impact of batteries on the technical reliability and economic viability of photovoltaic systems is determined. It was achieved through experimental testing and the development and adjustment of mathematical models. These models were implemented to preexisting software called PVSize. The improved software allows the calculation of different configurations of systems and to determine the loss of load probability and the figures of merit associated to the chosen economic-financial project. On this work was installed a photovoltaic system and was developed a battery testing system. The values measured in these systems allow to verify the mathematical models that describe the behavior of each device and characterize the components of the system. Experimental analysis of the behavior of a bank of batteries along a year showed that the connection of batteries in parallel accelerates the batteries degradation process, and this degradation has differentiated impact on the loss of

  18. A practical multi-objective design approach for optimum exhaust heat recovery from hybrid stand-alone PV-diesel power systems

    International Nuclear Information System (INIS)

    Yousefi, Moslem; Kim, Joong Hoon; Hooshyar, Danial; Yousefi, Milad; Sahari, Khairul Salleh Mohamed; Ahmad, Rodina Binti

    2017-01-01

    Highlights: • Heat recovery exchanger is designed based on practical conditions of a hybrid power system. • Off-the-grid electricity system modeling and analysis using micro-grid analysis software HOMER. • NSGA-II is used for the multi-objective design optimization task. • A new local search is proposed to incorporate the engineering knowledge in NSGA-II. • The proposed approach outperforms the existing ones. - Abstract: Integration of solar power and diesel generators (DGs) together with battery storage has proven to be an efficient choice for stand-alone power systems (SAPS). For higher energy efficiency, heat recovery from exhaust gas of the DG can also be employed to supply all or a portion of the thermal energy demand. Although the design of such heat recovery systems (HRSs) has been studied, the effect of solar power integration has not been taken into account. In this paper, a new approach for practical design of these systems based on varying engine loads is presented. Fast and elitist non-dominated sorting genetic algorithm (NSGA-II) equipped with a novel local search was used for the design process, considering conflicting objectives of annual energy recovery and total cost of the system, and six design variables. An integrated power system, designed for a remote SAPS, was used to evaluate the design approach. The optimum power supply system was first designed using the commercial software Hybrid Optimization of Multiple Energy Resources (HOMER), based on power demand and global solar energy in the region. Heat recovery design was based on the outcome of HOMER for DG hourly load, considering different power scenarios. The proposed approach improves the annual heat recovery of the PV/DG/battery system by 4%, PV/battery by 1.7%, and stand-alone DG by 1.8% when compared with a conventional design based on nominal DG load. The results prove that the proposed approach is effective and that load calculations should be taken into account prior to

  19. Stand-alone photovoltaic (PV) integrated with earth to air heat exchanger (EAHE) for space heating/cooling of adobe house in New Delhi (India)

    International Nuclear Information System (INIS)

    Chel, Arvind; Tiwari, G.N.

    2010-01-01

    This paper deals with an experimental outdoor annual performance evaluation of 2.32 kW P photovoltaic (PV) power system located at solar energy park in New Delhi composite climatic conditions. This PV system operates the daily electrical load nearly 10 kW h/day which comprises of various applications such as electric air blower of an earth to air heat exchanger (EAHE) used for heating/cooling of adobe house, ceiling fan, fluorescent tube-light, computer, submersible water pump, etc. The outdoor efficiencies, power generated and lost in PV system components were determined using hourly experimental measured data for 1 year on typical clear day in each month. These realistic data are useful for design engineers for outdoor assessment of PV system components. The energy conservation, mitigation of CO 2 emission and carbon credit potential of the existing PV integrated EAHE system is presented in this paper. Also, the energy payback time (EPBT) and unit cost of electricity were determined for both stand-alone PV (SAPV) and building roof integrated PV (BIPV) systems.

  20. Development of Stand Alone Application Tool for Processing and Quality Measurement of Weld Imperfection Image Captured by μ-Focused Digital Radiography Using MATLAB- Based Graphical User Interface

    Directory of Open Access Journals (Sweden)

    PZ Nadila

    2012-12-01

    Full Text Available Digital radiography incresingly is being applied in the fabrication industry. Compared to film- based radiography, digitally radiographed images can be acquired with less time and fewer exposures. However, noises can simply occur on the digital image resulting in a low-quality result. Due to this and the system’s complexity, parameters’ sensitivity, and environmental effects, the results can be difficult to interpret, even for a radiographer. Therefore, the need of an application tool to improve and evaluate the image is becoming urgent. In this research, a user-friendly tool for image processing and image quality measurement was developed. The resulting tool contains important components needed by radiograph inspectors in analyzing defects and recording the results. This tool was written by using image processing and the graphical user interface development environment and compiler (GUIDE toolbox available in Matrix Laboratory (MATLAB R2008a. In image processing methods, contrast adjustment, and noise removal, edge detection was applied. In image quality measurement methods, mean square error (MSE, peak signal-to-noise ratio (PSNR, modulation transfer function (MTF, normalized signal-to-noise ratio (SNRnorm, sensitivity and unsharpness were used to measure the image quality. The graphical user interface (GUI wass then compiled to build a Windows, stand-alone application that enables this tool to be executed independently without the installation of MATLAB.

  1. The Research on Second-Order ADRC Algorithm of Using Wind Turbine Virtual Inertia to Participate in Primary Frequency Regulation in a Small Stand-Alone Microgrid

    Directory of Open Access Journals (Sweden)

    Wang Yi

    2018-01-01

    Full Text Available In order to improve the transient stability of frequency in a small stand-alone microgrid (SSM, this paper takes a SSM composed of a direct-drive permanent magnet synchronous generator (D-PMSG and a micro gas turbine (MGT as the background and uses wind turbine generator (WTG virtual inertia (VI to participate in the primary (short-term system frequency regulation. First of all, this paper constructs a grid-connected model composed of a WTG and a MGT, analyzes the WTG virtual inertia frequency regulation mechanism, and explains the principle of proportional-differentiation (PD virtual inertia control (VIC and its shortcomings. Secondly, the paper introduces the structure principle of n-order active disturbance rejection control (ADRC and deduces the design process of second-order ADRC-VIC. Finally, through the simulation and experimental verification, comparing the frequency perturbation of without-VIC, PD-VIC, and ADRC-VIC, it is concluded that PD-VIC and ADRC-VIC both can use the WTG virtual inertia to participate in the primary frequency regulation. The frequency regulation effect of ADRC-VIC is better than PD-VIC, ADRC-VIC can extend the rotor speed recovery time and avoid overshoot, and its frequency fluctuation amplitude and settling time are obviously improved, and ADRC-VIC can effectively avoid the overshoot phenomenon of the MGT output power.

  2. Optimal Sizing of a Stand-Alone Hybrid Power System Based on Battery/Hydrogen with an Improved Ant Colony Optimization

    Directory of Open Access Journals (Sweden)

    Weiqiang Dong

    2016-09-01

    Full Text Available A distributed power system with renewable energy sources is very popular in recent years due to the rapid depletion of conventional sources of energy. Reasonable sizing for such power systems could improve the power supply reliability and reduce the annual system cost. The goal of this work is to optimize the size of a stand-alone hybrid photovoltaic (PV/wind turbine (WT/battery (B/hydrogen system (a hybrid system based on battery and hydrogen (HS-BH for reliable and economic supply. Two objectives that take the minimum annual system cost and maximum system reliability described as the loss of power supply probability (LPSP have been addressed for sizing HS-BH from a more comprehensive perspective, considering the basic demand of load, the profit from hydrogen, which is produced by HS-BH, and an effective energy storage strategy. An improved ant colony optimization (ACO algorithm has been presented to solve the sizing problem of HS-BH. Finally, a simulation experiment has been done to demonstrate the developed results, in which some comparisons have been done to emphasize the advantage of HS-BH with the aid of data from an island of Zhejiang, China.

  3. The international phase 4 validation study of the EORTC QLQ-SWB32: A stand-alone measure of spiritual well-being for people receiving palliative care for cancer

    NARCIS (Netherlands)

    Vivat, B.; Young, T. E.; Winstanley, J.; Arraras, J. I.; Black, K.; Boyle, F.; Bredart, A.; Costantini, A.; Guo, J.; Irarrazaval, M. E.; Kobayashi, K.; Kruizinga, R.; Navarro, M.; Omidvari, S.; Rohde, G. E.; Serpentini, S.; Spry, N.; van Laarhoven, H. W. M.; Yang, G. M.

    2017-01-01

    The EORTC Quality of Life Group has just completed the final phase (field-testing and validation) of an international project to develop a stand-alone measure of spiritual well-being (SWB) for palliative cancer patients. Participants (n = 451)-from 14 countries on four continents; 54% female; 188

  4. The Impact of Course Delivery Systems on Student Achievement and Sense of Community: A Comparison of Learning Community versus Stand-Alone Classroom Settings in an Open-Enrollment Inner City Public Community College

    Science.gov (United States)

    Bandyopadhyay, Pamela

    2010-01-01

    This study examined the effects of two types of course delivery systems (learning community classroom environments versus stand-alone classroom environments) on the achievement of students who were simultaneously enrolled in remedial and college-level social science courses at an inner city open-enrollment public community college. This study was…

  5. Hydrogen-based energy storage unit for stand alone PV systems; L'hydrogene electrolytique comme moyen de stockage d'electricite pour systemes photovoltaiques isoles

    Energy Technology Data Exchange (ETDEWEB)

    Labbe, J

    2006-12-15

    Stand alone systems supplied only by a photovoltaic generator need an energy storage unit to be fully self sufficient. Lead acid batteries are commonly used to store energy because of their low cost, despite several operational constraints. A hydrogen-based energy storage unit (HESU) could be another candidate, including an electrolyser, a fuel cell and a hydrogen tank. However many efforts still need to be carried out for this technology to reach an industrial stage. In particular, market outlets must be clearly identified. The study of small stationary applications (few kW) is performed by numerical simulations. A simulator is developed in the Matlab/Simulink environment. It is mainly composed of a photovoltaic field and a storage unit (lead acid batteries, HESU, or hybrid storage HESU/batteries). The system component sizing is achieved in order to ensure the complete system autonomy over a whole year of operation. The simulator is tested with 160 load profiles (1 kW as a yearly mean value) and three locations (Algeria, France and Norway). Two coefficients are set in order to quantify the correlation between the power consumption of the end user and the renewable resource availability at both daily and yearly scales. Among the tested cases, a limit value of the yearly correlation coefficient came out, enabling to recommend the use of the most adapted storage to a considered case. There are cases for which using HESU instead of lead acid batteries can increase the system efficiency, decrease the size of the photovoltaic field and improve the exploitation of the renewable resource. In addition, hybridization of HESU with batteries always leads to system enhancements regarding its sizing and performance, with an efficiency increase by 10 to 40 % depending on the considered location. The good agreement between the simulation data and field data gathered on real systems enabled the validation of the models used in this study. (author)

  6. Diagnostic performance of a stand-alone central blood pressure monitor: application of central blood pressure in the diagnosis of high blood pressure.

    Science.gov (United States)

    Cheng, Hao-Min; Sung, Shih-Hsien; Chuang, Shao-Yuan; Pearson, Alan; Tufanaru, Catalin; White, Sarahlouise; Yu, Wen-Chung; Chen, Chen-Huan

    2014-03-01

    Oscillometric central blood pressure (CBP) monitors have emerged as a new technology for blood pressure (BP) measurements. With a newly proposed diagnostic threshold for CBP, we investigated the diagnostic performance of a novel CBP monitor. We recruited a consecutive series of 138 subjects (aged 30-93 years) without previous use of antihypertensive agents for simultaneous invasive and noninvasive measurements of BP in a catheterization laboratory. With the cutoff (CBP ≥130/90 mm Hg) for high blood pressure (HBP), the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the novel CBP monitor were calculated with reference to the measured CBP. In comparison, the diagnostic performance of the conventional cuff BP was also evaluated. The noninvasive CBP for detecting HBP in a sample with a prevalence of 52% showed a sensitivity of 93% (95% confidence interval (CI) = 91-95), specificity of 95% (95% CI = 94-97), PPV of 96% (95% CI = 94-97), and NPV of 93% (95% CI = 90-95). In contrast, with cuff BP and the traditional HBP criterion (cuff BP ≥140/90 mm Hg), the sensitivity, specificity, PPV, and NPV were 49% (95% CI = 44-53), 94% (95% CI = 92-96), 90% (95% CI = 86-93), and 63% (95% CI 59-66), respectively. A stand-alone oscillometric CBP monitor may provide CBP values with acceptable diagnostic accuracy. However, with reference to invasively measured CBP, cuff BP had low sensitivity and NPV, which could render possible management inaccessible to a considerable proportion of HBP patients, who may be identifiable through noninvasive CBP measurements from the CBP monitor.

  7. A Lower T1 Slope as a Predictor of Subsidence in Anterior Cervical Discectomy and Fusion with Stand-Alone Cages.

    Science.gov (United States)

    Lee, Su Hun; Lee, Jun Seok; Sung, Soon Ki; Son, Dong Wuk; Lee, Sang Weon; Song, Geun Sung

    2017-09-01

    Preoperative parameters including the T1 slope (T1S) and C2-C7 sagittal vertical axis (SVA) have been recognized as predictors of kyphosis after laminoplasty, which is accompanied by posterior neck muscle damage. The importance of preoperative parameters has been under-estimated in anterior cervical discectomy and fusion (ACDF) because there is no posterior neck muscle damage. We aimed to determine whether postoperative subsidence and pseudarthrosis could be predicted according to specific parameters on preoperative plain radiographs. We retrospectively analyzed 41 consecutive patients (male: female, 22: 19; mean age, 51.15±9.25 years) who underwent ACDF with a stand-alone polyether-ether-ketone (PEEK) cage (>1 year follow-up). Parameters including SVA, T1S, segmental angle and range of motion (ROM), C2-C7 cervical angle and ROM, and segmental inter-spinous distance were measured on preoperative plain radiographs. Risk factors of subsidence and pseudarthrosis were determined using multivariate logistic regression. Fifty-five segments (27 single-segment and 14 two-segment fusions) were included. The subsidence and pseudarthrosis rates based on the number of segments were 36.4% and 29.1%, respectively. Demographic data and fusion level were unrelated to subsidence. A greater T1S was associated with a lower risk of subsidence (p=0.017, odds ratio=0.206). A cutoff value of T1Ssubsidence (sensitivity: 70%, specificity: 68.6%). There were no preoperative predictors of pseudarthrosis except old age. A lower T1S (T1Ssubsidence following ACDF. Surgeons need to be aware of this risk factor and should consider various supportive procedures to reduce the subsidence rates for such cases.

  8. Performance of natural curaua fiber-reinforced polyester composites under 7.62 mm bullet impact as a stand-alone ballistic armor

    Directory of Open Access Journals (Sweden)

    Fábio de Oliveira Braga

    2017-10-01

    Full Text Available A multilayered armor system (MAS is intended to personal protection against high kinetic energy ammunition. MAS layers are composed of materials such as a front ceramic and a back composite that must show both high impact resistance and low weight, usually conflicting characteristics. Synthetic fiber fabrics, such as Kevlar™ and Dyneema™, are the favorite materials to back the front ceramic, due to their high strength, high modulus and relatively low weight. Recently, composites reinforced with natural fibers have been considered as MAS second layer owing to their good performance associated with other advantages as being cheaper and environmentally friendly. Among the natural fibers, those extracted from the leaves of the Ananas erectifolius plant, known as curaua, stand out due to its exceptional high strength and high modulus. Thus, the objective of the present work is to evaluate the performance of curaua fiber-reinforced polyester composites subjected to ballistic impact of high energy 7.62 mm ammunition. Composites reinforced with 0, 10, 20 and 30 vol.% of curaua fibers were produced and stand-alone tested as armor target to evaluate the absorbed energy. Analysis of variance (Anova and Tukey's honest significant difference test (HSD made it possible to compare the results to Kevlar™ laminates. Among the tested materials, the 30 vol.% fiber composites were found to be the best alternative to Kevlar™. Keywords: Composite, Natural fiber, Curaua fiber, Ballistic test

  9. Effects of a stand-alone web-based electronic screening and brief intervention targeting alcohol use in university students of legal drinking age: A randomized controlled trial.

    Science.gov (United States)

    Ganz, Thomas; Braun, Michael; Laging, Marion; Schermelleh-Engel, Karin; Michalak, Johannes; Heidenreich, Thomas

    2018-02-01

    Many intervention efforts targeting student drinking were developed to address US college students, which usually involves underage drinking. It remains unclear, if research evidence from these interventions is generalizable to university and college students of legal drinking age, e.g., in Europe. To evaluate the effectiveness of a translated and adapted version of the eCHECKUP TO GO, applied as stand-alone web-based electronic screening and brief intervention (e-SBI), in German university students at risk for hazardous drinking. A fully automated web-based two-arm parallel-group randomized controlled trial was conducted. Participants were randomized to an e-SBI or assessment-only (AO) condition. The current paper analyzed students with baseline AUDIT-C scores ≥3 for women and ≥4 for men (sample at baseline: e-SBI [n=514], AO [n=467]; 3-month follow-up: e-SBI [n=194], AO [n=231]; 6-month follow-up: e-SBI [n=146], AO [n=200]). The primary outcome was prior four weeks' alcohol consumption. Secondary outcomes were frequency of heavy drinking occasions, peak blood alcohol concentration, and number of alcohol-related problems. Mixed linear model analyses revealed significant interaction effects between groups and time points on the primary outcome after 3 and 6months. Compared to students in the AO condition, students in the e-SBI condition reported consuming 4.11 fewer standard drinks during the previous four weeks after 3months, and 4.78 fewer standard drinks after 6months. Mixed results were found on secondary outcomes. The results indicate that evidence on and knowledge of web-based e-SBIs based on US college student samples is transferable to German university students of legal drinking age. However, knowledge of what motivates students to complete programs under voluntary conditions, although rare, is needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Comparison of a Stand-Alone Anchored Spacer Versus Plate-Cage Construct in the Treatment of Two Noncontiguous Levels of Cervical Spondylosis: A Preliminary Investigation.

    Science.gov (United States)

    Shi, Sheng; Zheng, Shuang; Li, Xin-Feng; Yang, Li-Li; Liu, Zu-De; Yuan, Wen

    2016-05-01

    The application of stand-alone anchored spacer (SAAS) in anterior cervical discectomy and fusion (ACDF) has been proven to be safe and effective to treat cervical spondylosis. Skip-level ACDF with SAAS, fusing only the involved levels without anterior plates, may be the optimal treatment. The aim of the study was to compare the clinical outcomes, radiologic results of SAAS, and plate-cage construct in the treatment of 2 noncontiguous levels of cervical spondylosis. A total of 65 patients with 2 noncontiguous levels of cervical spondylosis were included in the retrospective review of prospective collected data. The clinical and radiologic outcomes were assessed with the Japanese Orthopaedic Association score, Neck Disability Index, cervical alignment, and range of motion and disc height of intermediate segment, respectively. All the aforementioned parameters were compared before and after surgery in the respective group, which also were compared between the 2 groups. Complications also were recorded, and correlations between the surgical outcome and various factors were analyzed. No significant differences existed in clinical results between the 2 groups (P > 0.05). In addition, no statistical significance was observed in fusion rate, cervical alignment, and range of motion and disc height of intermediate segment, dysphagia, and hoarseness (P > 0.05). Preoperative Japanese Orthopaedic Association score and high-intensity signal in T2-weighted images were important predictors for surgical outcome. Skip-level ACDF with SAAS is a safe and effective treatment of 2 noncontiguous levels of cervical spondylosis without obvious contraindications, which can keep the IS intact, and have a low impact on the IS. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. CANGS DB: a stand-alone web-based database tool for processing, managing and analyzing 454 data in biodiversity studies.

    Science.gov (United States)

    Pandey, Ram Vinay; Nolte, Viola; Boenigk, Jens; Schlötterer, Christian

    2011-06-30

    Next generation sequencing (NGS) is widely used in metagenomic and transcriptomic analyses in biodiversity. The ease of data generation provided by NGS platforms has allowed researchers to perform these analyses on their particular study systems. In particular the 454 platform has become the preferred choice for PCR amplicon based biodiversity surveys because it generates the longest sequence reads. Nevertheless, the handling and organization of massive amounts of sequencing data poses a major problem for the research community, particularly when multiple researchers are involved in data acquisition and analysis. An integrated and user-friendly tool, which performs quality control, read trimming, PCR primer removal, and data organization is desperately needed, therefore, to make data interpretation fast and manageable. We developed CANGS DB (Cleaning and Analyzing Next Generation Sequences DataBase) a flexible, stand alone and user-friendly integrated database tool. CANGS DB is specifically designed to organize and manage the massive amount of sequencing data arising from various NGS projects. CANGS DB also provides an intuitive user interface for sequence trimming and quality control, taxonomy analysis and rarefaction analysis. Our database tool can be easily adapted to handle multiple sequencing projects in parallel with different sample information, amplicon sizes, primer sequences, and quality thresholds, which makes this software especially useful for non-bioinformaticians. Furthermore, CANGS DB is especially suited for projects where multiple users need to access the data. CANGS DB is available at http://code.google.com/p/cangsdb/. CANGS DB provides a simple and user-friendly solution to process, store and analyze 454 sequencing data. Being a local database that is accessible through a user-friendly interface, CANGS DB provides the perfect tool for collaborative amplicon based biodiversity surveys without requiring prior bioinformatics skills.

  12. CANGS DB: a stand-alone web-based database tool for processing, managing and analyzing 454 data in biodiversity studies

    Directory of Open Access Journals (Sweden)

    Schlötterer Christian

    2011-06-01

    Full Text Available Abstract Background Next generation sequencing (NGS is widely used in metagenomic and transcriptomic analyses in biodiversity. The ease of data generation provided by NGS platforms has allowed researchers to perform these analyses on their particular study systems. In particular the 454 platform has become the preferred choice for PCR amplicon based biodiversity surveys because it generates the longest sequence reads. Nevertheless, the handling and organization of massive amounts of sequencing data poses a major problem for the research community, particularly when multiple researchers are involved in data acquisition and analysis. An integrated and user-friendly tool, which performs quality control, read trimming, PCR primer removal, and data organization is desperately needed, therefore, to make data interpretation fast and manageable. Findings We developed CANGS DB (Cleaning and Analyzing Next Generation Sequences DataBase a flexible, stand alone and user-friendly integrated database tool. CANGS DB is specifically designed to organize and manage the massive amount of sequencing data arising from various NGS projects. CANGS DB also provides an intuitive user interface for sequence trimming and quality control, taxonomy analysis and rarefaction analysis. Our database tool can be easily adapted to handle multiple sequencing projects in parallel with different sample information, amplicon sizes, primer sequences, and quality thresholds, which makes this software especially useful for non-bioinformaticians. Furthermore, CANGS DB is especially suited for projects where multiple users need to access the data. CANGS DB is available at http://code.google.com/p/cangsdb/. Conclusion CANGS DB provides a simple and user-friendly solution to process, store and analyze 454 sequencing data. Being a local database that is accessible through a user-friendly interface, CANGS DB provides the perfect tool for collaborative amplicon based biodiversity surveys

  13. Size-exclusion chromatography as a stand-alone methodology identifies novel markers in mass spectrometry analyses of plasma-derived vesicles from healthy individuals

    Directory of Open Access Journals (Sweden)

    Armando de Menezes-Neto

    2015-07-01

    Full Text Available Plasma-derived vesicles hold a promising potential for use in biomedical applications. Two major challenges, however, hinder their implementation into translational tools: (a the incomplete characterization of the protein composition of plasma-derived vesicles, in the size range of exosomes, as mass spectrometric analysis of plasma sub-components is recognizably troublesome and (b the limited reach of vesicle-based studies in settings where the infrastructural demand of ultracentrifugation, the most widely used isolation/purification methodology, is not available. In this study, we have addressed both challenges by carrying-out mass spectrometry (MS analyses of plasma-derived vesicles, in the size range of exosomes, from healthy donors obtained by 2 alternative methodologies: size-exclusion chromatography (SEC on sepharose columns and Exo-Spin™. No exosome markers, as opposed to the most abundant plasma proteins, were detected by Exo-Spin™. In contrast, exosomal markers were present in the early fractions of SEC where the most abundant plasma proteins have been largely excluded. Noticeably, after a cross-comparative analysis of all published studies using MS to characterize plasma-derived exosomes from healthy individuals, we also observed a paucity of “classical exosome markers.” Independent of the isolation method, however, we consistently identified 2 proteins, CD5 antigen-like (CD5L and galectin-3-binding protein (LGALS3BP, whose presence was validated by a bead-exosome FACS assay. Altogether, our results support the use of SEC as a stand-alone methodology to obtain preparations of extracellular vesicles, in the size range of exosomes, from plasma and suggest the use of CD5L and LGALS3BP as more suitable markers of plasma-derived vesicles in MS.

  14. Impact of a stand-alone course in gerontological nursing on undergraduate nursing students' perceptions of working with older adults: A Quasi-experimental study.

    Science.gov (United States)

    Koehler, Amy Reitmaier; Davies, Susan; Smith, Linda Reveling; Hooks, Tisha; Schanke, Hailee; Loeffler, April; Carr, Courtney; Ratzlaff, Nicole

    2016-11-01

    With an aging population, it is critical that nurses are educated and prepared to offer quality healthcare to this client group. Incorporating gerontology content into nursing curricula and addressing students' perceptions and career choices in relation to working with older adults are important faculty concerns. To examine the impact of a stand-alone course in gerontological nursing on undergraduate nursing students' perceptions of working with older adults and career intentions. Quasi-experimental, pre- and post-test design. Medium-sized state university in the Mid Western United States PARTICIPANTS: Data were collected from three student cohorts during the spring semesters of 2012 (n=98), 2013 (n=80) and 2014 (n=88) for a total of N=266 with an average response rate of 85%. A survey instrument was administered via Qualtrics and completed by students prior to, and following completion of the course. There was an overall significant increase (p=0.000) in positive perceptions of working with older adults among nursing students following completion of the course. The majority of participants (83.5%) reported having previous experience with older adults. Those with previous experience had higher perception scores at pre-test than those without (p=0.000). Post-test scores showed no significant difference between these two groups, with both groups having increased perception scores (p=0.120). Student preferences for working with different age groups suggested an overall increase in preference for working with older adults following the course. A course in gerontological nursing, incorporating learning partnerships with community dwelling older adults, promotes positive perceptions of working with older adults, independently of the quality of prior experience. There was some evidence that students changed their preferences of working with different age groups in favor of working with older adults. Further research should be conducted to determine the mechanisms through

  15. Stand-alone containment analysis of Phébus FPT tests with ASTEC and MELCOR codes: the FPT-2 test

    Directory of Open Access Journals (Sweden)

    Bruno Gonfiotti

    2018-03-01

    Full Text Available During the last 40 years, many studies have been carried out to investigate the different phenomena occurring during a Severe Accident (SA in a Nuclear Power Plant (NPP. Such efforts have been supported by the execution of different experimental campaigns, and the integral Phébus FP tests were probably some of the most important experiments in this field. In these tests, the degradation of a Pressurized Water Reactor (PWR fuel bundle was investigated employing different control rod materials and burn-up levels in strongly or weakly oxidizing conditions. From the findings on these and previous tests, numerical codes such as ASTEC and MELCOR have been developed to analyze the evolution of a SA in real NPPs. After the termination of the Phébus FP campaign, these two codes have been furthermore improved to implement the more recent findings coming from different experimental campaigns. Therefore, continuous verification and validation is still necessary to check that the new improvements introduced in such codes allow also a better prediction of these Phébus tests. The aim of the present work is to re-analyze the Phébus FPT-2 test employing the updated ASTEC and MELCOR code versions. The analysis focuses on the stand-alone containment aspects of this test, and three different spatial nodalizations of the containment vessel (CV have been developed. The paper summarizes the main thermal-hydraulic results and presents different sensitivity analyses carried out on the aerosols and fission products (FP behavior. When possible, a comparison among the results obtained during this work and by different authors in previous work is also performed. This paper is part of a series of publications covering the four Phébus FP tests using a PWR fuel bundle: FPT-0, FPT-1, FPT-2, and FPT-3, excluding the FPT-4 one, related to the study of the release of low-volatility FP and transuranic elements from a debris bed and a pool of melted fuel. Keywords: Safety

  16. Wireless network of stand-alone end effect probes for soil in situ permittivity measurements over the 100MHZ-6GHz frequency range

    Science.gov (United States)

    Demontoux, François; Bircher, Simone; Ruffié, Gilles; Bonnaudiin, Fabrice; Wigneron, Jean-Pierre; Kerr, Yann

    2017-04-01

    , it should be useful to install many probes on the same site to obtain permittivity measurements over a large area. To reach this goal, the probes should communicate with each other to send data to a record device. Furthermore, it is needed to record measurements over a long time period (many months) to study the in-situ dielectric soil property variations according to changing weather conditions and seasonal trends. The goal of the research work presented is to develop a dielectric sensor system based on end effect probes able to communicate the data using wireless technology. It must be stand-alone from an electric and data recording point of view so it must integrate a VNA circuit instead of the ANRITSU VNA used for the moment. The LoRa wireless technology has been selected because of its low electric consumption and the large distance between equipment available. LoRaWAN™ is a Low Power Wide Area Network specification intended for wireless battery operated devices. The LoRaWAN data rates range from 0.3 kbps to 50 kbps which is sufficient for our probes' data exchanges. We will present the work done to perform the VNA and the LoRa communication board as well as the work done to improve the probes and the permittivity computation algorithm.

  17. IEA PVPS Task 3. Use of photovoltaic systems in stand-alone and island applications. 'Swiss participation'; IEA PVPS Task 3. Use of photovoltaic systems in stand-alone and island applications. 'Participation Suisse'

    Energy Technology Data Exchange (ETDEWEB)

    Villoz, M. [Dynatex SA, Morges (Switzerland)

    2004-07-01

    This report describes the work done during five years of the second phase of Task 3 of the photovoltaic power systems programme of the International Energy Agency (IEA-PVPS). Task 3 activities were concentrated on stand-alone photovoltaic systems with the main effort on improving the quality and reducing the cost of these systems. The work was divided in 2 sub-tasks whose first one was concentrated on quality insurance schemes and second one on technical recommendations coming from practical experience. Twelve original reports have been published covering topics that can be sorted in 4 categories: the first one is dedicated on quality issues with a review of existing standards in the participating countries and a double paper giving quality assurance recommendations on project management and examples of applying these rules in practical cases. The second category dwelled on photovoltaic systems with papers on charge controllers, on lightning protection and monitoring of systems. The third category presents interesting studies on the storage of energy which remains the main subject where improvements should be made in order to lower the cost of energy; four papers describe the management and the test procedures of lead-acid batteries, how to choose a lead-acid battery and finally are there alternatives to lead-acid batteries for the storage of photovoltaic electricity. The last category worked on loads and users of renewable energy and gives a large amount of experience with loads, how to choose them and how the energy can be better used through demand side management. (author)

  18. The Over-Production of Freshman English

    Science.gov (United States)

    Koon, William

    1974-01-01

    Argues that the proliferation of teaching methods and materials in recent years has resulted in low quality instruction and concludes that the "over-production" of freshman English will cease when teachers begin to feel that what they "teach is worth the trouble." (RB)

  19. Freshman Orientation Evaluation, Shoreline Community College.

    Science.gov (United States)

    Hartley, Gordon

    Evaluation of the freshman orientation program at Shoreline Community College (Washington) was approached through the use of several criteria: (l) results of the Brown-Holtzman Survey of Study Habits and Attitudes (SSHA), (2) comparison of first-quarter grade averages with orientation program attendance records, (3) the completion of a…

  20. Broadly tunable, high-power terahertz radiation up to 73 K from a stand-alone Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ} mesa

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, T.; Watanabe, C.; Ishida, K.; Sekimoto, S.; Asanuma, K.; Yasui, T.; Nakade, K.; Shibano, Y.; Saiwai, Y. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Kashiwagi, T.; Minami, H.; Kadowaki, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Yamamoto, T. [Wide Bandgap Materials Group, Optical and Electronic Materials Unit, Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Tsujimoto, M. [Department of Electronic Science and Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Klemm, R. A. [Department of Physics, University of Central Florida, Orlando, Florida 32816-2385 (United States)

    2014-11-17

    High-power, continuous, broadly tunable THz radiation from 0.29 to 1.06 THz, was obtained from the outer current-voltage characteristic (IVC) branch of a single stand-alone mesa of the high-transition temperature T{sub c} superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ}. The particular metallic film structures placed both beneath and atop the mesas resulted in more efficient heat dissipation, higher allowed applied dc voltages, larger IVC loops, wider emission temperature ranges, and much broader emission frequency tunability than obtained previously.

  1. Minimally invasive lateral transpsoas interbody fusion using a stand-alone construct for the treatment of adjacent segment disease of the lumbar spine: review of the literature and report of three cases.

    Science.gov (United States)

    Palejwala, Sheri K; Sheen, Whitney A; Walter, Christina M; Dunn, Jack H; Baaj, Ali A

    2014-09-01

    We describe 3 patients who presented with radiographic signs and clinical symptoms of adjacent segment disease several years after undergoing L4-S1 posterior pedicle screw fusion. All patients underwent successful lateral lumbar interbody fusion (LLIF) at 1-2 levels above their previous constructs, using stand-alone cages, with complete resolution of radiculopathy and a significant improvement in low-back pain. In addition to a thorough analysis of these cases, we review the pertinent literature regarding treatment options for adjacent segment disease and the applications of the lateral lumbar interbody technique. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Admissions and Plebe Year Data as Indicators of Academic Success in Engineering Majors at the United States Naval Academy

    National Research Council Canada - National Science Library

    Kristof, Nicholas

    2002-01-01

    This research analyzes the relationship between academic success in high school and at the freshman collegiate level and academic performance in engineering majors at the United States Naval Academy (USNA...

  3. Feasibility Analysis and Simulation of a Stand-Alone Photovoltaic Energy System for Electricity Generation and Environmental Sustainability – equivalent to 650VA fuel-powered generator - popularly known as I pass my neighbour

    Directory of Open Access Journals (Sweden)

    Vincent Anayochukwu Ani

    2015-09-01

    Full Text Available Photovoltaic (PV power system can be used to replace wholly 650VA generator for electricity generation for household use in Nigeria. This paper presented the feasibility analysis of load data and simulation study of a stand-alone PV power system that produced the electrical needs of a household. This study is based on designing of PV energy system for household use. The patterns of load consumption within the household were studied and suitably modeled for simulation. The simulation study indicates that energy requirements to provide electricity which is equivalent to 650VA generator for household use in Nigeria can be accomplished by 520W solar PV array, 2312 Ah nominal capacity battery, and a 1kW DC/AC inverter. This would be suitable for deployment of 100% clean energy for environmental sustainability and uninterruptable power performance in the household. The results of this research show that, with a low-power consuming appliances, it is possible to meet the entire annual electricity demand of a single household solely through a stand-alone PV energy supply. Installing solar panels by most Nigerian home can significantly reduce home reliance on government power thereby reduce the strain on the current capacity of our power generation infrastructure. A detailed design and description of the system were presented in this paper.

  4. Feasibility Analysis and Simulation of a Stand-Alone Photovoltaic Energy System for Electricity Generation and Environmental Sustainability – Equivalent to 650VA Fuel-Powered Generator – Popularly Known as “I Pass My Neighbour”

    International Nuclear Information System (INIS)

    Ani, Vincent Anayochukwu

    2015-01-01

    Photovoltaic (PV) power system can be used to replace wholly 650VA generator for electricity generation for household use in Nigeria. This paper presented the feasibility analysis of load data and simulation study of a stand-alone PV power system that produced the electrical needs of a household. This study is based on designing of PV energy system for household use. The patterns of load consumption within the household were studied and suitably modeled for simulation. The simulation study indicates that energy requirements to provide electricity, which is equivalent to 650VA generator for household use in Nigeria, can be accomplished by 520 W solar PV array, 2312 Ah nominal capacity battery, and a 1 kW DC/AC inverter. This would be suitable for deployment of 100% clean energy for environmental sustainability and uninterruptable power performance in the household. The results of this research show that, with a low-power consuming appliances, it is possible to meet the entire annual electricity demand of a single household solely through a stand-alone PV energy supply. Installing solar panels by most Nigerian home can significantly reduce home reliance on government power thereby reduce the strain on the current capacity of our power generation infrastructure. A detailed design and description of the system were presented in this paper.

  5. What do seniors remember from freshman physics?

    Directory of Open Access Journals (Sweden)

    Andrew Pawl

    2012-12-01

    Full Text Available We have given a group of 56 Massachusetts Institute of Technology (MIT seniors who took mechanics as freshmen a written test similar to the final exam they took in their freshman course as well as the Mechanics Baseline Test (MBT and the Colorado Learning Attitudes about Science Survey (CLASS. Students in majors unrelated to physics scored 60% lower on the written analytic part of the final than they would have as freshmen. The mean score of all participants on the MBT was insignificantly changed from their average on the posttest they took as freshmen. However, the students’ performance on 9 of the 26 MBT items (with 6 of the 9 involving graphical kinematics represents a gain over their freshman posttest score (a normalized gain of about 70%, while their performance on the remaining 17 questions is best characterized as a loss of approximately 50% of the material learned in the freshman course. On multiple-choice questions covering advanced physics concepts, the mean score of the participants was about 50% lower than the average performance of freshmen. Although attitudinal survey results indicate that almost half the seniors feel the specific mechanics course content is unlikely to be useful to them, a significant majority (75%–85% feel that physics does teach valuable problem solving skills, and an overwhelming majority believe that mechanics should remain a required course at MIT.

  6. Is the radiographic subsidence of stand-alone cages associated with adverse clinical outcomes after cervical spine fusion? An observational cohort study with 2-year follow-up outcome scoring.

    Science.gov (United States)

    Zajonz, Dirk; Franke, Anne-Catherine; von der Höh, Nicolas; Voelker, Anna; Moche, Michael; Gulow, Jens; Heyde, Christoph-Eckhard

    2014-01-01

    The stand-alone treatment of degenerative cervical spine pathologies is a proven method in clinical practice. However, its impact on subsidence, the resulting changes to the profile of the cervical spine and the possible influence of clinical results compared to treatment with additive plate osteosynthesis remain under discussion until present. This study was designed as a retrospective observational cohort study to test the hypothesis that radiographic subsidence of cervical cages is not associated with adverse clinical outcomes. 33 cervical segments were treated surgically by ACDF with stand-alone cage in 17 patients (11 female, 6 male), mean age 56 years (33-82 years), and re-examined after eight and twenty-six months (mean) by means of radiology and score assessment (Medical Outcomes Study Short Form (MOS-SF 36), Oswestry Neck Disability Index (ONDI), painDETECT questionnaire and the visual analogue scale (VAS)). Subsidence was observed in 50.5% of segments (18/33) and 70.6% of patients (12/17). 36.3% of cases of subsidence (12/33) were observed after eight months during mean time of follow-up 1. After 26 months during mean time of follow-up 2, full radiographic fusion was seen in 100%. MOS-SF 36, ONDI and VAS did not show any significant difference between cases with and without subsidence in the two-sample t-test. Only in one type of scoring (painDETECT questionnaire) did a statistically significant difference in t-Test emerge between the two groups (p = 0.03; α = 0.05). However, preoperative painDETECT score differ significantly between patients with subsidence (13.3 falling to 12.6) and patients without subsidence (7.8 dropped to 6.3). The radiological findings indicated 100% healing after stand-alone treatment with ACDF. Subsidence occurred in 50% of the segments treated. No impact on the clinical results was detected in the medium-term study period.

  7. Transition into College Sports: The Freshman Student-Athlete.

    Science.gov (United States)

    Purdy, Dean; And Others

    Changes in attitude, motivation, and values take place in the academic, athletic, and social areas of student-athletes' lives during their freshman year of college. Twenty incoming college freshman athletes involved in "revenue" sports (football, basketball, and ice hockey) participated in this study and were interviewed in the fall and again in…

  8. College Retention Initiatives Meeting the Needs of Millennial Freshman Students

    Science.gov (United States)

    Turner, Patrick; Thompson, Elizabeth

    2014-01-01

    The qualitative study explored the opinions and perceptions of freshman, sophomores, and freshman students that dropped out of the university to understand the obstacles and enablers that millennial freshmen faced transitioning into a college environment. To understand these factors the study posed the question, how do the participants (i.e.,…

  9. Cage subsidence does not, but cervical lordosis improvement does affect the long-term results of anterior cervical fusion with stand-alone cage for degenerative cervical disc disease: a retrospective study.

    Science.gov (United States)

    Wu, Wen-Jian; Jiang, Lei-Sheng; Liang, Yu; Dai, Li-Yang

    2012-07-01

    Clinical outcomes of the stand-alone cage have been encouraging when used in anterior cervical discectomy and fusion (ACDF), but concerns remain regarding its complications, especially cage subsidence. This retrospective study was undertaken to investigate the long-term radiological and clinical outcomes of the stand-alone titanium cage and to evaluate the incidence of cage subsidence in relation to the clinical outcome in the surgical treatment of degenerative cervical disc disease. A total of 57 consecutive patients (68 levels) who underwent ACDF using a titanium box cage for the treatment of cervical radiculopathy and/or myelopathy were reviewed for the radiological and clinical outcomes. They were followed for at least 5 years. Radiographs were obtained before and after surgery, 3 months postoperatively, and at the final follow-up to determine the presence of fusion and cage subsidence. The Cobb angle of C2-C7 and the vertebral bodies adjacent to the treated disc were measured to evaluate the cervical sagittal alignment and local lordosis. The disc height was measured as well. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) score for cervical myelopathy, before and after surgery, and at the final follow-up. The recovery rate of JOA score was also calculated. The Visual Analogue Scale (VAS) score of neck and radicular pain were evaluated as well. The fusion rate was 95.6% (65/68) 3 months after surgery. Successful bone fusion was achieved in all patients at the final follow-up. Cage subsidence occurred in 13 cages (19.1%) at 3-month follow-up; however, there was no relation between fusion and cage subsidence. Cervical and local lordosis improved after surgery, with the improvement preserved at the final follow-up. The preoperative disc height of both subsidence and non-subsidence patients was similar; however, postoperative posterior disc height (PDH) of subsidence group was significantly greater than of non-subsidence group

  10. Chapter 2: Stand-alone Applications - TOPCAT

    Science.gov (United States)

    Miller, C. J.

    Tool for OPerations on Catalogues And Tables or TOPCAT is a graphical viewer for table data. It offers a variety of ways to work with data tables, including a browser for the cell data, viewers for information about table and column metadata, dataset visualization, and even analysis. We discuss a small subset of TOPCAT's functionalities in this chapter. TOPCAT was originally developed as part of the Starlink program in the United Kingdom. It is now maintained by AstroGrid. The program is written in pure Java and available under the GNU General Public License. It is available for download and a version is included in the software distribution accompanying this book. TOPCAT is a GUI interface on top of the STIL library. A command line interface to this library, STILTS, described in Chapter 21 provides scriptable access to many of the capabilities described here. The purpose of this tutorial is to provide an overview of TOPCAT to the novice user. The best place to look for and learn about TOPCAT is the web page maintained by Mark B. Taylor. There, TOPCAT documentation is provided in HTML, PDF, via screen shots, etc. In this chapter we take the user through a few examples that give the general idea of how TOPCAT works. The majority of the functionality of TOPCAT is not included in this short tutorial. Our goal in this tutorial is to lead the reader through an exercise that would result in a publication quality figure (e.g. for a journal article). Specifically, we will use TOPCAT to show how the color-magnitude relation of a galaxy cluster compares to that of all galaxies in the Sloan Digital Sky Survey (York et al. 2000). This diagnostic is used not only in cluster finding, but its linear fit can provide insight into the age and/or metallicity of the oldest galaxies in galaxy clusters (which are some of the oldest galaxies in the Universe). The data we need for this exercise are: 1) the entire spectroscopic galaxy catalog from the SDSS, with galaxy positions, galaxy redshifts, and galaxy magnitudes and 2) galaxy members of a known galaxy cluster. For the former, we will download data directly from the SDSS servers to our local machine for analysis. For the latter, we will use TOPCAT's ability to call live cone search services.

  11. Informing Approaches in Establishing Stand Alone Community ...

    African Journals Online (AJOL)

    Literacy is usually considered the ability to read at a basic level. Now it is beginning to be defined more broadly to include applying reading, writing, and mathematical skills to obtain and use information and solve problems at levels of proficiency necessary to function in society, to achieve one's goals and develop one's ...

  12. Stand Alone Battery Thermal Management System

    Energy Technology Data Exchange (ETDEWEB)

    Brodie, Brad [Denso International America, Incorporated, Southfield, MI (United States)

    2015-09-30

    The objective of this project is research, development and demonstration of innovative thermal management concepts that reduce the cell or battery weight, complexity (component count) and/or cost by at least 20%. The project addresses two issues that are common problems with current state of the art lithium ion battery packs used in vehicles; low power at cold temperatures and reduced battery life when exposed to high temperatures. Typically, battery packs are “oversized” to satisfy the two issues mentioned above. The first phase of the project was spent making a battery pack simulation model using AMEsim software. The battery pack used as a benchmark was from the Fiat 500EV. FCA and NREL provided vehicle data and cell data that allowed an accurate model to be created that matched the electrical and thermal characteristics of the actual battery pack. The second phase involved using the battery model from the first phase and evaluate different thermal management concepts. In the end, a gas injection heat pump system was chosen as the dedicated thermal system to both heat and cool the battery pack. Based on the simulation model. The heat pump system could use 50% less energy to heat the battery pack in -20°C ambient conditions, and by keeping the battery cooler at hot climates, the battery pack size could be reduced by 5% and still meet the warranty requirements. During the final phase, the actual battery pack and heat pump system were installed in a test bench at DENSO to validate the simulation results. Also during this phase, the system was moved to NREL where testing was also done to validate the results. In conclusion, the heat pump system can improve “fuel economy” (for electric vehicle) by 12% average in cold climates. Also, the battery pack size, or capacity, could be reduced 5%, or if pack size is kept constant, the pack life could be increased by two years. Finally, the total battery pack and thermal system cost could be reduced 5% only if the system is integrated with the vehicle cabin air conditioning system. The reason why we were not able to achieve the 20% reduction target is because of the natural decay of the battery cell due to the number of cycles. Perhaps newer battery chemistries that are not so sensitive to cycling would have more potential for reducing the battery size due to thermal issues.

  13. Stand alone biofuel production from algae

    NARCIS (Netherlands)

    Wijffels, R.H.; Janssen, M.G.J.; Barbosa, M.J.

    2011-01-01

    In this feature, leading researchers in the field of microbial biotechnology speculate on the technical and conceptual developments that will drive innovative research and open new vistas over the next few years

  14. Stand-alone tsunami alarm equipment

    Science.gov (United States)

    Katsumata, Akio; Hayashi, Yutaka; Miyaoka, Kazuki; Tsushima, Hiroaki; Baba, Toshitaka; Catalán, Patricio A.; Zelaya, Cecilia; Riquelme Vasquez, Felipe; Sanchez-Olavarria, Rodrigo; Barrientos, Sergio

    2017-05-01

    One of the quickest means of tsunami evacuation is transfer to higher ground soon after strong and long ground shaking. Ground shaking itself is a good initiator of the evacuation from disastrous tsunami. Longer period seismic waves are considered to be more correlated with the earthquake magnitude. We investigated the possible application of this to tsunami hazard alarm using single-site ground motion observation. Information from the mass media is sometimes unavailable due to power failure soon after a large earthquake. Even when an official alarm is available, multiple information sources of tsunami alert would help people become aware of the coming risk of a tsunami. Thus, a device that indicates risk of a tsunami without requiring other data would be helpful to those who should evacuate. Since the sensitivity of a low-cost MEMS (microelectromechanical systems) accelerometer is sufficient for this purpose, tsunami alarm equipment for home use may be easily realized. Amplitude of long-period (20 s cutoff) displacement was proposed as the threshold for the alarm based on empirical relationships among magnitude, tsunami height, hypocentral distance, and peak ground displacement of seismic waves. Application of this method to recent major earthquakes indicated that such equipment could effectively alert people to the possibility of tsunami.

  15. The Rhetoric of Satire: Analyzing in Freshman English.

    Science.gov (United States)

    Proctor, Betty Jane

    1982-01-01

    Presents a series of exercises designed to provide freshman composition students with a base for analyzing works rhetorically, to point out how language can be used persuasively, and to illustrate how satire functions. (FL)

  16. The international phase 4 validation study of the EORTC QLQ-SWB32: A stand-alone measure of spiritual well-being for people receiving palliative care for cancer.

    Science.gov (United States)

    Vivat, B; Young, T E; Winstanley, J; Arraras, J I; Black, K; Boyle, F; Bredart, A; Costantini, A; Guo, J; Irarrazaval, M E; Kobayashi, K; Kruizinga, R; Navarro, M; Omidvari, S; Rohde, G E; Serpentini, S; Spry, N; Van Laarhoven, H W M; Yang, G M

    2017-11-01

    The EORTC Quality of Life Group has just completed the final phase (field-testing and validation) of an international project to develop a stand-alone measure of spiritual well-being (SWB) for palliative cancer patients. Participants (n = 451)-from 14 countries on four continents; 54% female; 188 Christian; 50 Muslim; 156 with no religion-completed a provisional 36-item measure of SWB plus the EORTC QLQ-C15-PAL (PAL), then took part in a structured debriefing interview. All items showed good score distribution across response categories. We assessed scale structure using principal component analysis and Rasch analysis, and explored construct validity, and convergent/divergent validity with the PAL. Twenty-two items in four scoring scales (Relationship with Self, Relationships with Others, Relationship with Someone or Something Greater, and Existential) explained 53% of the variance. The measure also includes a global SWB item and nine other items. Scores on the PAL global quality-of-life item and Emotional Functioning scale weakly-moderately correlated with scores on the global SWB item and two of the four SWB scales. This new validated 32-item SWB measure addresses a distinct aspect of quality-of-life, and is now available for use in research and clinical practice, with a role as both a measurement and an intervention tool. © 2017 John Wiley & Sons Ltd.

  17. Alternative route of process modification for biofuel production by embedding the Fischer-Tropsch plant in existing stand-alone power plant (10 MW) based on biomass gasification - Part I: A conceptual modeling and simulation approach (a case study in Thailand)

    DEFF Research Database (Denmark)

    Hunpinyo, Piyapong; Cheali, Peam; Narataruksa, Phavanee

    2014-01-01

    The utilization of syngas shows a highly potential to improve the economic potential of the stand-alone power unit-based gasification plants as well as enhancing the growing demand of transportation fuels. The thermochemical conversion of biomass via gasification to heat and power generations from...

  18. Poster - Thurs Eve-17: Stand alone software for deforming delivered dose distributions to account for daily anatomical variations in prostate patients treated on the TomoTherapy Hi-Art II system.

    Science.gov (United States)

    Rivest, R; Riauka, T; Murtha, A; Fallone, G

    2008-07-01

    The acquisition of daily megavoltage (MV)-CT images provides an invaluable tool in the delivery of adaptive radiotherapy (ART) on the TomoTherapy Hi-ART II system. Using TomoTherapy's Planned Adaptive software, delivery sinograms can be applied to pre-treatment MVCT images to generate daily delivered dose distributions, allowing for the potential comparison of planned and delivered doses. However, daily patient anatomical variations complicate the task and accurate comparison requires that daily doses be evaluated in the same references frame as the planned dose. Each anatomical point in daily MVCT images must be mapped to its corresponding point in the patient planning CT and that deformation map must be applied to the daily dose distribution. Stand alone software has been developed for the comparison of planned and delivered doses for TomoTherapy prostate patients. Software inputs are the planning CT, planning structure data, planned dose distribution, daily MVCT and delivered dose distribution. The software uses an in-house developed automatic voxel-based deformable registration algorithm designed and optimized specifically for the registration of prostate CT images to achieve anatomical correspondence between MVCT and planning images. The resultant deformation map is applied to the daily dose distribution and the software outputs the deformed daily dose distribution in the planning CT's reference frame, as well as a delivered DVH for each of the planning CT's ROI. The software allows for a number of potential research opportunities, in particular, the calculation of the cumulative dose delivered over the course of treatment for prostate patients treated on the Hi-Art II system. © 2008 American Association of Physicists in Medicine.

  19. Freshman Seminars: Interdisciplinary Engagements in Astronomy

    Science.gov (United States)

    Hemenway, M. K.

    2006-08-01

    The Freshman Seminar program at the University of Texas is designed to allow groups of fifteen students an engaging introduction to the University. The seminars introduce students to the resources of the university and allow them to identify interesting subjects for further research or future careers. An emphasis on oral and written communication by the students provides these first-year students a transition to college-level writing and thinking. Seminar activities include field trips to an art museum, a research library, and the Humanities Research Center rare book collection. This paper will report on two seminars, each fifteen weeks in length. In "The Galileo Scandal" students examine Galileo's struggle with the church (including a mock trial). They perform activities that connect his use of the telescope and observations to astronomical concepts. In "Astronomy and the Humanities" students analyze various forms of human expression that have astronomical connections (art, drama, literature, music, poetry, and science fiction); they perform hands-on activities to reinforce the related astronomy concepts. Evaluation of the seminars indicates student engagement and improvement in communication skills. Many of the activities could be used independently to engage students enrolled in standard introductory astronomy classes.

  20. Perspective on the Freshman Year: Volume II. Selected Major Addresses from Freshman Year Experience Conferences. The Freshman Year Experience: Monograph Series Number 8.

    Science.gov (United States)

    Boyer, Ernest L.; And Others

    This volume contains the text of six speeches selected from approximately 125 plenary talks that have been given over the past few years at more than 40 Freshman Year Experience Conferences by leading educators concerned about improving the first year undergraduate experience. In the first speech, "The Undergraduate Experience: Critical…

  1. From Retention to Satisfaction: New Outcomes for Assessing the Freshman Experience. AIR 1994 Annual Forum Paper.

    Science.gov (United States)

    Sanders, Liz; And Others

    To meet accountability challenges from a customer-satisfaction perspective, an urban institution of higher education has developed an integrated approach to studying the freshman year experience in order to develop comprehensive outcomes measures for assessing freshman success. Multiple sources of data (freshman satisfaction survey data,…

  2. STAND-ALONE WIND ENERGY CONVERSION SYSTEM WITH MAXIMUM POWER TRANSFER CONTROL SISTEMA AISLADO DE CONVERSIÓN EÓLICA CON CONTROL DE MÁXIMA TRANSFERENCIA DE POTENCIA

    Directory of Open Access Journals (Sweden)

    Miguel López

    2009-12-01

    Full Text Available A controlled wind generation system for a stand alone application is presented in this paper. A cascaded step-up/step-down power electronic converters topology is proposed to control the wind power system in the whole wind speed range. For the low wind speed range, the control strategy is aimed to follow the wind turbine’s maximal power coefficient by adjusting the generator’s rotational speed. For high wind speeds, the system power regulation is also made by controlling the generator speed. This control is made by the DC/DC power electronic converter, which modifies its input voltage, changing the machine voltage and consequently varying the generator’s rotor speed. The proposed system is validated by computer simulation. The proposed control system shows a good performance for its application in autonomous wind energy systems.Un sistema de generación eólica para una aplicación aislada es presentado en este artículo. Una topología de convertidores electrónicos de potencia elevador y reductor conectados en cascada es propuesta para controlar la producción eólica en todo el rango de velocidades del viento. Para el rango de vientos suaves, la estrategia de control permite seguir el máximo coeficiente de potencia de turbina eólica mediante el ajuste de la velocidad de rotación del generador. En el rango de vientos fuertes, la regulación de la potencia del sistema se hace igualmente por control de la velocidad de giro del generador. La acción de control es realizada mediante el convertidor DC/DC de potencia el cual modifica su tensión de entrada, cambiando así la tensión en los terminales de la máquina y por consecuencia variando la velocidad de rotación del generador. El sistema propuesto es validado mediante simulación por computador. Los resultados muestran que el sistema de control propuesto actúa de buena manera para su aplicación en sistemas autónomos de generación eólica.

  3. Fuel Cell Car Design Project for Freshman Engineering Courses

    Science.gov (United States)

    Duke, Steve R.; Davis, Virginia A.

    2014-01-01

    In the Samuel Ginn College of Engineering at Auburn University, we have integrated a semester long design project based on a toy fuel cell car into our freshman "Introduction to Chemical Engineering Class." The project provides the students a basic foundation in chemical reactions, energy, and dimensional analysis that facilitates…

  4. Literature and Shalom: Teaching Freshman Students to Read

    Science.gov (United States)

    Bowen, Deborah C.

    2008-01-01

    Wolterstorff's argument for art as a form of action that enables us to anticipate shalom and Ricoeur's concept of the narrative intelligence developed in the reader of stories are tested out in a freshman non-specialist English class where the interpretation of literature, covered by the power of prayer, fosters both intellectual and moral…

  5. The Freshman Integrated Curriculum at Texas A&M University.

    Science.gov (United States)

    Malave, Cesar O.; Watson, Karan L.

    This paper presents implementation details related to the freshman integrated curriculum at Texas A&M University. Specifically, the need for strong integration between physics, calculus, engineering problem solving, engineering design graphics, and English is emphasized. The paper presents a brief summary of the design and pilot implementation…

  6. Focus on Freshman: Basic Instruction Programs Enhancing Physical Activity

    Science.gov (United States)

    Curry, Jarred; Jenkins, Jayne M.; Weatherford, Jennifer

    2015-01-01

    Physical activity sharply decreases after different life stages, particularly high school graduation to beginning university education. The purpose of this study was to investigate the effect of a specifically designed university physical activity class, Exercise Planning for Freshman (EPF), on students' physical activity and group cohesion…

  7. Designing Freshman Interest Groups That Address Millennial Learning Styles

    Science.gov (United States)

    Ratliff, Gerald Lee

    2011-01-01

    Residential Freshman Interest Groups (FIGS) have recently become a popular instructional and social model for academic and student affairs colleagues who are concerned that millennial students learn to reflect on life experiences and daily events as part of the learning process. An introductory FIG program recognizes that millennial students are…

  8. Freshman Orientation Sessions Can Teach Incoming Students about Healthful Lifestyles

    Science.gov (United States)

    Freedman, Marjorie R.; Waldrop, Jennifer

    2011-01-01

    This GEM describes the "Freshman 15 Jeopardy" workshop, a 30-minute nutrition education session aimed to expose incoming college freshmen to the college food environment, to increase their awareness of factors that cause weight gain, and to instruct them on lifestyle choices they could employ to prevent weight gain. This short workshop has not…

  9. The Freshman Odyssey: Classical Metaphors for Counseling College Students.

    Science.gov (United States)

    Sandoz, Jeff

    This paper highlights the use of analogies and metaphors in counseling sessions with a focus on the college freshman experience as a living, contemporary example of how clients may experience mythic themes in their lives. Drawing from the ideas of Joseph Campbell, characters found in classical Greek mythology, as well as contemporary myths as…

  10. Social and Emotional Learning in a Freshman Seminar

    Science.gov (United States)

    Wyatt, Jeannette B.; Bloemker, Geraldine A.

    2013-01-01

    First year college students are challenged both socially and academically in their transition to college life. The literature suggests that social and emotional competence skills can help with this transition. This article describes the course content for a University freshman seminar that teaches skills in social and emotional competence in order…

  11. Freshman and Sophomore Business Students’ Perception of Global Forces

    OpenAIRE

    Bahadir K. Akcam; Ahmet Guler; Hakan Hekim

    2012-01-01

    The purpose of this article is to describe the perception on global forces of business major freshman and sophomore undergraduate students in the United States. As global forces deeply impact business life around the world, educators are looking for ways to provide necessary knowledge and skills in business education curricula to develop competitive and competent students who are prepared for the global economy. Although such efforts focus on the end result in education, understanding student...

  12. Predicting academic problems in college from freshman alcohol involvement.

    Science.gov (United States)

    Wood, P K; Sher, K J; Erickson, D J; DeBord, K A

    1997-03-01

    The present article examines the relation of problematic alcohol use to collegiate academic problems based on a systematic assessment of problematic alcohol use and college transcript data. The degree to which this prospective association can be explained by reference to third variables is also explored. These third variables include: students' high school academic achievement and aptitude, concurrent drug use, participation in deviant behaviors and students' investment or participation in the college experience. A sample of 444 (240 female) college freshman recruited for a longitudinal study of alcohol use was followed for 6 years. Alcohol and drug involvement, general deviance, academic investment, campus involvement and several background variables were assessed during the freshman year. Additional measures of high school aptitude and achievement as well as collegiate performance were calculated based on college transcript data from all institutions attended. A latent variable structural equation model revealed that problematic alcohol use during the freshman year correlated +.32 with collegiate academic problems. No evidence was found for a unique association between the two constructs when additional constructs were included in the model. Specifically, the association was substantially reduced when preexisting student differences traditionally associated with academic failure in college were taken into account. The inclusion of concurrent drug use and deviance also resulted in a significant reduction in the magnitude of the association. Although a substantial bivariate association exists between problematic alcohol use and academic problems during college, much of this association appears attributable to preexisting student differences on admission to college.

  13. A comparison of anterior cervical discectomy and fusion (ACDF) using self-locking stand-alone polyetheretherketone (PEEK) cage with ACDF using cage and plate in the treatment of three-level cervical degenerative spondylopathy: a retrospective study with 2-year follow-up.

    Science.gov (United States)

    Chen, Yuqiao; Lü, Guohua; Wang, Bing; Li, Lei; Kuang, Lei

    2016-07-01

    To evaluate the clinical efficacy and radiological outcomes of anterior cervical discectomy and fusion (ACDF) using self-locking polyetheretherketone (PEEK) cages for treatment of three-level cervical degenerative spondylopathy. Twenty-eight patients underwent three-level ACDF using self-locking stand-alone PEEK cages (group A), and 26 patients underwent three-level ACDF using cages and plate fixation (group B) were reviewed retrospectively. Clinical efficacy was evaluated by pre- and post-operative Japanese Orthopedic Association (JOA) scores and Neck Disability Index (NDI). The operation time, blood loss, surgical results according to Odom's criteria and post-operative dysphagia status were also recorded. Radiological outcomes including fusion, cervical Cobb's lordosis, fused segment angle, disc height, and cage subsidence were assessed. Clinical outcome measures such as dysphagia and fusion rate and the results of surgery evaluated according to Odom's criteria were not statistically significant (P > 0.05) between groups. The operation time was shorter and blood loss was less in group A (P  0.05). Post-operative cage subsidence, the loss of disc height, cervical lordosis and the fused segment angle were relatively higher in group A than group B (P < 0.05). ACDF using self-locking stand-alone cages showed similar clinical results as compared to ACDF using cages and plate fixation for the treatment of three-level cervical degenerative spondylopathy. However, potential long-term problems such as cage subsidence, loss of cervical lordosis and fused segment angle post-operatively were shown to be associated with patients who underwent ACDF using self-locking stand-alone cages.

  14. Freshmen Women and the "Freshman 15": Perspectives on Prevalence and Causes of College Weight Gain

    Science.gov (United States)

    Smith-Jackson, TeriSue; Reel, Justine J.

    2012-01-01

    Objective: Freshman weight gain has been assessed using quantitative inquiry, but this qualitative study allowed for an in-depth exploration of freshmen women's experiences surrounding body image, nutrition, and exercise. The purpose of this study was to better understand the impact and explanations for the "Freshman 15." Participants: Freshmen…

  15. Supporting Transition of At-Risk Students through a Freshman Orientation Model

    Science.gov (United States)

    DeLamar, Shawna; Brown, Casey Graham

    2016-01-01

    This study examines the issues surrounding middle school students' transitions to high school and the degree to which freshman orientation models can help them. The attendance, discipline, report card grades, and end-of-course exams of 60 students who participated in a freshman orientation were compared to those of 150 students who were invited to…

  16. An Investigation of the Relationship between Language Learning Strategies and Learning Styles in Turkish Freshman Students

    Science.gov (United States)

    Balci, Özgül

    2017-01-01

    The purpose of this study is to determine the relationship between the language learning strategies of freshman students and their learning styles. This study is a descriptive research and employs a relational screening model. Participants of the study were 328 freshman students majoring in different fields at Necmettin Erbakan University Ahmet…

  17. Perceived stress and freshman weight change: the moderating role of baseline body mass index.

    Science.gov (United States)

    Boyce, Jessica A; Kuijer, Roeline G

    2015-02-01

    The transition from high-school to university is a critical period of weight change. Popular media suggest that freshman students gain 15 lb (6.80 kg) of body weight during their first year at university (i.e., the freshman 15). In contrast, a recent meta-analysis calculated freshman weight gain to be 1.75 kg, with statistics suggesting that only a proportion of freshman students are prone to gain weight. Researchers are beginning to investigate how certain variables and interactions between such variables predict freshman weight status. The current study focused on body mass index (BMI) and psychological stress. In isolation, previous research has tested how these two variables predict freshman student's weight status. However, because BMI and stress interact to predict weight gain and weight loss in adult samples, the current study tested the interaction between student's baseline BMI and baseline stress levels to predict weight change in a New Zealand sample of freshman students (N=65). Participants completed two separate online surveys in March and October 2012 (i.e., New Zealand's academic year). Although only three students gained over 6.80 kg (i.e., the freshman 15), participants did gain a statistically significant 1.10 kg of body weight during the year. Consistent with previous research, students with a higher baseline BMI gained a higher amount of body weight. However, this main effect was qualified by an interaction between stress and BMI. Students who entered university with high levels of stress gained weight if they also had high BMIs; if they had lower BMIs then they lost weight. In order to reduce unhealthy levels of freshman weight change, vulnerable students need to be taught stress-reduction techniques and coping strategies early in the academic year. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Environmental Nanoscience: Turning Outreach Activities into a College Freshman Seminar

    Science.gov (United States)

    Nguyen, M. L.; Lau, B.

    2017-12-01

    Teaching nano concepts can be a daunting task due to the varying science backgrounds of the audience. Nonetheless, nanoscience education is important as nanotechnology expands. Our perspective is that nano education must be available at earlier stages than what is currently available. Through outreach activities, we examined how high school students and STEM middle/high school teachers approached answering questions about nanomaterials and the environment to design an effective freshman-level college seminar with achievable course goals. Specifically, participants were asked: 1) what color would you expect gold nanoparticles to be; 2) what are ways we can remove nanomaterials from the environment; and 3) what do you expect will happen to nanomaterials when salt is introduced into the system? Initial analysis showed STEM middle and high school teachers and high school students responded similarly. In response to question 1, the majority of the responses suggested color was a function of size. For question 2, both groups suggested the use of filters, magnets or a chemical reaction to remove the nanomaterials. For question 3, both groups expected a chemical reaction to occur. Understanding how foundational high school STEM concepts influenced responses could assist in the curriculum development for an introductory undergraduate nanoscience course. For example, familiar principles of physics and chemistry appeared to direct student responses. From these results, we developed three course goals to test in our college freshman seminar: 1) differentiate between properties of nanomaterials and conventional materials; 2) describe the role of nanomaterials in household items; and 3) form an opinion on the potential impacts of nanoscience and technology on the human health and the environment. Surveys from our first semester showed that the seminar was effective in achieving all course goals for the majority of students.

  19. Basic Stand Alone Medicare Prescription Drug Events PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This is a Public Use File for Prescription Drug Events drawn from the 2008 Beneficiary Summary File of Medicare beneficiaries enrolled during the calendar year 2008,...

  20. Closure of army stand alone housing areas: An environmental adventure

    International Nuclear Information System (INIS)

    Ricci, J.A.

    1992-01-01

    In October 1988, Congress passed the Defense Authorization Amendments and Base Closure and Realignment Act, Public Law 100-526. This legislation provided the framework for making decisions about military base closures and realignments. The overall objective of the legislation was to close and realign bases to maximize savings without impairing the Army's overall military mission. In December 1988, the Defense Secretary's ad hoc Commission on Base Realignment and Closure issued its final report nominating candidate installations. Among the installations affected by the commission's recommendations, which were subsequently approved by Congress, were 53 military housing areas. The paper recounts the process by which each of the 53 housing areas was assessed to determine if any environmental restoration was to be performed prior to property sale. Each phase of the program is addressed from the Enhanced Preliminary Assessment through the issuance of a 'Statement of Condition' which, in accordance with Army real property regulations, is required prior to property transfer. The unique challenges presented by the housing areas are high-lighted; where materials such as asbestos, radon and fuel oil predominated, as opposed to laboratory chemicals and hazardous waste from industrial operations. In addition, attention is given to the myriad disciplines which interface in preparing a housing area for closure. Forty-three Statements of Condition have been issued to date, with the remainder to be prepared upon completion of remediation activities at each site

  1. Basic Stand Alone Medicare Claims Public Use Files

    Data.gov (United States)

    U.S. Department of Health & Human Services — CMS is committed to increasing access to its Medicare claims data through the release of de-identified data files available for public use. They contain...

  2. A stand-alone tidal prediction application for mobile devices

    Science.gov (United States)

    Tsai, Cheng-Han; Fan, Ren-Ye; Yang, Yi-Chung

    2017-04-01

    It is essential for people conducting fishing, leisure, or research activities at the coasts to have timely and handy tidal information. Although tidal information can be found easily on the internet or using mobile device applications, this information is all applicable for only certain specific locations, not anywhere on the coast, and they need an internet connection. We have developed an application for Android devices, which allows the user to obtain hourly tidal height anywhere on the coast for the next 24 hours without having to have any internet connection. All the necessary information needed for the tidal height calculation is stored in the application. To develop this application, we first simulate tides in the Taiwan Sea using the hydrodynamic model (MIKE21 HD) developed by the DHI. The simulation domain covers the whole coast of Taiwan and the surrounding seas with a grid size of 1 km by 1 km. This grid size allows us to calculate tides with high spatial resolution. The boundary conditions for the simulation domain were obtained from the Tidal Model Driver of the Oregon State University, using its tidal constants of eight constituents: M2, S2, N2, K2, K1, O1, P1, and Q1. The simulation calculates tides for 183 days so that the tidal constants for the above eight constituents of each water grid can be extracted by harmonic analysis. Using the calculated tidal constants, we can predict the tides in each grid of our simulation domain, which is useful when one needs the tidal information for any location in the Taiwan Sea. However, for the mobile application, we only store the eight tidal constants for the water grids on the coast. Once the user activates the application, it reads the longitude and latitude from the GPS sensor in the mobile device and finds the nearest coastal grid which has our tidal constants. Then, the application calculates tidal height variation based on the harmonic analysis. The application also allows the user to input location and time to obtain tides for any historic or future dates for the input location. The predicted tides have been verified with the historic tidal records of certain tidal stations. The verification shows that the tides predicted by the application match the measured record well.

  3. PMBLDCG based stand-alone wind energy conversion system for ...

    African Journals Online (AJOL)

    International Journal of Engineering, Science and Technology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 4, No 1 (2012) >. Log in or Register to get access to full text downloads.

  4. Performance evaluation of stand alone hybrid PV-wind generator

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H. [Faculty of Electrical Engineering, Universiti Teknikal Malaysia Melaka (UTeM), Hang Tuah Jaya, 76100 Melaka (Malaysia); Yahaya, M. S. [Faculty of Engineering Technology, Universiti Teknikal Malaysia Melaka (UTeM), Hang Tuah Jaya, 76100 Melaka (Malaysia)

    2015-05-15

    This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand.

  5. PMBLDCG based stand-alone wind energy conversion system for ...

    African Journals Online (AJOL)

    user

    David et al 2001, Simoes and Farret 2004,. Bhadra et al 2004, Ackermann 2005). The permanent magnet ..... David Sharpe Burton, Jenkins Nick and Bossanyi Ervin, 2001. “Wind Energy Handbook,” John Wiley & Sons. Ltd. Gieras J. F. and ...

  6. Performance evaluation of stand alone hybrid PV-wind generator

    Science.gov (United States)

    Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H.; Yahaya, M. S.

    2015-05-01

    This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand.

  7. Performance evaluation of stand alone hybrid PV-wind generator

    International Nuclear Information System (INIS)

    Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H.; Yahaya, M. S.

    2015-01-01

    This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand

  8. Algal Hydrogen Production -- Stand Alone or Integrated System?

    Energy Technology Data Exchange (ETDEWEB)

    Ghirardi, Maria L.; Maness, Pin Ching; Kosourovo, Sergey

    2016-01-01

    Photosynthetic bacteria and green algae photoproduce H2. but do so utilizing different catalysts and substrates. Green algae use reductant generate mostly by water oxidation to catalyze the reduction of protons to H2 gas, while photosynthetic bacteria catalyze H2 production from organic acids using the nitrogenase enzyme. Moreover, these two organisms utilize different regions of the solar spectrum to perform photosynthesis: green algae's light harvesting antenna is comprised of chlorophyll molecules that absorb mostly blue and red light; photosynthetic bacteria harvest blue and far-red light through their light-harvesting pigments to run its non-oxygenic photosynthetic reactions. There is thus an opportunity to increase the range of solar spectrum used to photoproduce H2 by combining the light-harvesting and catalytic properties of these two organisms in a single process. In the current manuscript, we describe an experimental system that validates this hypothesis and demonstrates quantitatively the advantages of a two organism process for production of higher amounts of H2 and thus achieving solar light conversion efficiencies.

  9. She stands alone: Pakistani woman film director, Shireen Pasha.

    Science.gov (United States)

    Mustafa, A

    1995-01-01

    This article describes the activities of film director Shireen Pasha in promoting truth in the mass media in Pakistan. Pasha is described as one who finds it inexcusable in a state-subsidized system that national problems of poverty are not aired openly. Pasha has pursued the goal of exposing the real lives of Pakistanis on film in contrast to the publicly aired segments of "pretty girls in nice drawing rooms." Foreign channels available through satellite communications technology are viewed by Pasha as inappropriate with regard to people's needs and uncreative. Pakistan began with one channel, PTV, which recently refused to air her documentary on living conditions in Pakistan's rural areas "The Travelogue Pakistan." "The Walled City of Lahore" was her film about life in the old city. Both films poetically depicted the honor of humans and their struggle to stay alive. Some of her documentaries are made to show the value of indigenous skills, centuries old know-how, and traditions, regardless of the poverty. Pasha is described as fighting with PTV management over use of resources. Pasha desires to invest in training people to do documentaries or be more field-oriented rather than investing in equipment. Pasha joined PTV in 1975 and left in 1990. Pasha is recognized for her isolation as a woman in the business world, her commitment to exposing remote cultures and truth, and the odds she must confront in attaining her goals. Pasha is committed to doing extensive research, usually conducted during the summer months, in order to construct a credible story line that is produced usually during the winter months. One model of film story line is defined as one where women are portrayed as starting from an indigenous skill or knowledge and shifting to a greater position of power and control over their lives. Pasha believes that people who make films have the responsibility to evoke a reaction in people and to offer solutions. Two acclaimed films, which were supported by USAID and the government, were "Before It's Too Late" and "Only One Way." Both deal with resource issues and the environment. She is currently director of her own film house, The Film Makers, in Lahore. After graduating from the National College of Arts in 1968, she furthered her education in the US in the history of art.

  10. Deterrents on the Over Utilisation of Stand Alone Photovoltaic (PV ...

    African Journals Online (AJOL)

    At inception of the programme, systems were either undersized, or over utilised as clients did not reveal their usage needs in an attempt to reduce costs. This resulted in battery failures and other system breakdowns. The NPVREP categorised systems in order to alleviate the problem of under sizing and/or over utilization of ...

  11. Academy News

    Indian Academy of Sciences (India)

    How to combat infectious diseases: The role of Science Academies · Academy Public Lecture and INSA–Leopoldina Lecture by Prof. Jörg Hacker, President, German Academy of Sciences Leopoldina. 4 December, 2017, 4 PM Faculty Hall, Indian Institute ...

  12. [Depression and stress management in medical students. A comparative study between freshman and advanced medical students].

    Science.gov (United States)

    Jurkat, H B; Richter, L; Cramer, M; Vetter, A; Bedau, S; Leweke, F; Milch, W

    2011-05-01

    International studies have indicated a high prevalence of depression and a lack of coping with stress in medical students. Freshman and advanced medical students were investigated using a specific questionnaire and the Beck Depression Inventory (BDI) with a response rate of 100%. Of the subjects studied 81.1% did not have any depression, 13.1% slight and 5.8% clinically relevant symptoms of depression. The severity of symptoms was highly associated with subjective appraisal of stressors. Coping skills of first year students significantly influenced the depression symptoms calling for preventative measures even in freshman medical students.

  13. Academy Trust

    Indian Academy of Sciences (India)

    The Academy Trust (tAcT) was set up in August 2014 as a non-governmental entity under the auspices of the Indian Academy of Sciences (IASc), Bengaluru. Working closely with some of the most distinguished scientific minds in the country through the Fellowship of the IASc, the Trust hopes to bring about a tangible ...

  14. University 101 Freshman Seminar Course: A Longitudinal Study of Persistence, Retention, and Graduation Rates.

    Science.gov (United States)

    Shanley, Mark G.; Witten, Charles H.

    1990-01-01

    Investigated the differences in persistence and graduation rates after seven years, resulting from participation in a freshman seminar course at the University of South Carolina. Findings confirmed strongly positive association between successful completion of University 101 and increased retention, persistence, and graduation rates for freshman…

  15. Weight Changes, Exercise, and Dietary Patterns during Freshman and Sophomore Years of College.

    Science.gov (United States)

    Racette, Susan B.; Deusinger, Susan S.; Strube, Michael J.; Highstein, Gabrielle R.; Deusinger, Robert H.

    2005-01-01

    Weight gain and behavioral patterns during college may contribute to overweight and obesity in adulthood. The aims of this study were to assess weight, exercise, and dietary patterns of 764 college students (53% women, 47% men) during freshman and sophomore years. Students had their weight and height measured and completed questionnaires about…

  16. Project-Based Curriculum for Teaching Analytical Design to Freshman Engineering Students via Reconfigurable Trebuchets

    Science.gov (United States)

    Herber, Daniel R.; Deshmukh, Anand P.; Mitchell, Marlon E.; Allison, James T.

    2016-01-01

    This paper presents an effort to revitalize a large introductory engineering course for incoming freshman students that teaches them analytical design through a project-based curriculum. This course was completely transformed from a seminar-based to a project-based course that integrates hands-on experimentation with analytical work. The project…

  17. Raising the Bar in Freshman Science Education: Student Lectures, Scientific Papers, and Independent Experiments

    Science.gov (United States)

    Collins, Eva-Maria S.; Calhoun, Tessa R.

    2014-01-01

    This article presents the combination of three enhanced educational approaches for training future scientists. These methods incorporate skills generally not introduced in the freshman year: student-led blackboard introductions; the writing of scientific papers; and the design, execution, and presentation of an independent lab module. We tested…

  18. Exploring Cystic Fibrosis Using Bioinformatics Tools: A Module Designed for the Freshman Biology Course

    Science.gov (United States)

    Zhang, Xiaorong

    2011-01-01

    We incorporated a bioinformatics component into the freshman biology course that allows students to explore cystic fibrosis (CF), a common genetic disorder, using bioinformatics tools and skills. Students learn about CF through searching genetic databases, analyzing genetic sequences, and observing the three-dimensional structures of proteins…

  19. Strategies Employed by Iranian EFL Freshman University Students in Extensive Listening: A Qualitative Research

    Science.gov (United States)

    Bidabadi, Farinaz Shirani; Yamat, Hamidah

    2014-01-01

    This paper discusses the findings of a qualitative study on the strategies employed by Iranian freshmen in extensive listening. A group of 12 freshman university students were purposefully selected based on their scores in the Oxford Placement Test administered. Four learners were identified as advanced, four as intermediate, and four as lower…

  20. Reorganizing Freshman Business Mathematics II: Authentic Assessment in Mathematics through Professional Memos

    Science.gov (United States)

    Green, Kris; Emerson, Allen

    2008-01-01

    The first part of this two-part paper [see EJ787497] described the development of a new freshman business mathematics (FBM) course at our college. In this paper, we discuss our assessment tool, the business memo, as a venue for students to apply mathematical skills, via mathematical modelling, to realistic business problems. These memos have…

  1. Prevalence of marijuana use at college entry and risk factors for initiation during freshman year.

    Science.gov (United States)

    Suerken, Cynthia K; Reboussin, Beth A; Sutfin, Erin L; Wagoner, Kimberly G; Spangler, John; Wolfson, Mark

    2014-01-01

    Marijuana is currently the most commonly used drug on college campuses. Marijuana use among college students is increasing, and many students begin using marijuana during college. The goal of this study was to investigate predictors of lifetime marijuana use at college entry and initiation during freshman year. We used responses from the first two semesters of a longitudinal study of 3146 students from 11 colleges in North Carolina and Virginia. Random-effects logistic regression models were constructed to identify factors that predict lifetime marijuana use at college entry and initiation during freshman year. Nearly 30% of students reported ever having used marijuana at college entry. Among students who had never used marijuana prior to college, 8.5% initiated use during freshman year. In multivariable logistic regression models, having at least $100 per month in spending money; attending church rarely or never; current use of cigarettes, alcohol, and hookah tobacco; lifetime use of other illicit drugs; and a higher propensity toward sensation seeking were associated with a higher likelihood of having used marijuana at least once at college entry. Hispanic ethnicity, living on campus, and current use of cigarettes and alcohol were associated with a higher likelihood of initiating marijuana use during freshman year. These results have implications for targeting substance abuse prevention programs on college campuses.

  2. Change in Diet, Physical Activity, and Body Weight in Female College Freshman

    Science.gov (United States)

    Butler, Scott M.; Black, David R.; Blue, Carolyn L.; Gretebeck, Randall J.

    2004-01-01

    Objective: To examine diet, physical activity, and body-weight changes associated with relocation from home to university. Methods: Diet, fitness/physical activity, body-weight parameters and self-efficacy were assessed among 54 freshman women upon college entry and 5 months later. Results: Although caloric intake significantly decreased, a…

  3. Pros and Cons of a Group Webpage Design Project in a Freshman Anatomy and Physiology Course

    Science.gov (United States)

    Crisp, Kevin M.; Jensen, Murray; Moore, Randy

    2007-01-01

    To generate motivation and promote the development of written communication skills, students in a freshman-level anatomy and physiology course for nonmajors created group webpages describing historically important diseases. After the groups had been formed, each individual was assigned specific components of the disease (e.g., causes or…

  4. Alternative route of process modification for biofuel production by embedding the Fischer–Tropsch plant in existing stand-alone power plant (10 MW) based on biomass gasification – Part I: A conceptual modeling and simulation approach (a case study in Thailand)

    International Nuclear Information System (INIS)

    Hunpinyo, Piyapong; Cheali, Peam; Narataruksa, Phavanee; Tungkamani, Sabaithip; Chollacoop, Nuwong

    2014-01-01

    Graphical abstract: SynBiofuel production through existing gasification plants in Thailand, using waste agricultural biomass as raw material, was studied. The process design was initiated conceptually in the areas of gas phase reaction system via Fischer-Tropsch (FT) synthesis. The development of FT configurations on syngas conversion to transportation fuels (e.g., diesel range) was investigated. In order to develop a techno-economic assessment, the three different capacities corresponding to 1 MW, 2 MW and 3 MW based on thermal input of syngas were evaluated. Once-through FT concept was proposed in which the unconverted syngas was combusted with air in an externally fired gas turbine (EFGT) to produce surplus electricity. The results of process simulation were discussed open-mindedly including the overall plant design and energy efficiency. Preliminary economics, and some site specific situations under which additional capital cost savings on existing infrastructure was realized. - Highlights: • Experimental results were used and integrated with a reactor model for SynBiofuel. • Process simulation with the lumped reaction rate was used to achieve accurate results. • Process simulation was performed using ASPEN Plus to design FT configurations. • Maximum energy FT efficiency was approximately 37%. • Economic potential was computed by ROI and PBP resulting in the attractive solutions. - Abstract: The utilization of syngas shows a highly potential to improve the economic potential of the stand-alone power unit-based gasification plants as well as enhancing the growing demand of transportation fuels. The thermochemical conversion of biomass via gasification to heat and power generations from the earlier study is further enhanced by integrating Fischer–Tropsch (FT) synthesis with the existing gasification pilot scale studied previously. To support the potential and perspectives in major economies due to scaling up in developing countries such as Thailand

  5. Freshman year alcohol and marijuana use prospectively predict time to college graduation and subsequent adult roles and independence.

    Science.gov (United States)

    Wilhite, Emily R; Ashenhurst, James R; Marino, Elise N; Fromme, Kim

    2017-06-15

    This study examined how freshman year substance use prospectively predicted time to college graduation, and whether delayed graduation predicted postponed adoption of adult roles and future substance use. Participants were part of a longitudinal study that began in 2004. The first analyses focused on freshman year (N = 2,050). The second analyses corresponded to a subset of participants at age 27 (N = 575). Measures included self-reported substance use, adult role adoption, and university reported graduation dates. Results indicated that frequent binge drinking and marijuana use during freshman year predicted delayed college graduation. Those who took longer to graduate were more likely to have lower incomes and were less likely to obtain a graduate degree. Taking 5-6 years to graduate was associated with greater likelihood of alcohol-related problems. Findings support the importance of interventions during freshman year of college to decrease substance use and promote timely graduation.

  6. Cognitive style and plebe turnover at the U.S. Naval Academy.

    Science.gov (United States)

    Mitchell, Tom; Cahill, Alice M

    2005-08-01

    Students entering (N = 1,134) the U.S. Naval Academy class of 2000 were administered the Kirton Adaption-Innovation Inventory on the first day of Plebe Summer, a 7-wk. nonacademic training program completed by all entering students in the summer prior to the freshman year. The mean score on Innovation cognitive style for this sample of plebes was approximately a standard deviation lower than those of five other undergraduate student samples from nonmilitary universities. Furthermore, the 98 plebes who voluntarily withdrew before completing the program scored higher on the average on Innovation than those who remained. Findings suggest that, in terms of Person-Organization fit, plebes with a more innovative cognitive style may, perhaps, be less compatible with the regimentation-style climate of the Academy than those with an Adaptive cognitive style. Further research, however, is needed to specify the relationship between Academy students' cognitive style and other important organizational outcomes.

  7. A Study on the Mental Health Status and Life-style in University Freshman

    OpenAIRE

    佐々木, 浩子

    2008-01-01

    In order to make clear the life-style and mental health status in university freshman, I carried out a questionnaire for the students. This questionnaire is composed by personal profile (gender, age, school year), the lifestyle (hobby, exercise, dietary, drinking, smoking, and sleeping habits), and mental health status (GHQ: The General Health Questionnaire). The questionnaire was given to the students taking a general education class in April 2005 and 2006. The results obtained were as follo...

  8. Predicting Freshman Grade Point Average From College Admissions Test Scores and State High School Test Scores

    OpenAIRE

    Koretz, Daniel; Yu, C; Mbekeani, Preeya Pandya; Langi, M.; Dhaliwal, Tasminda Kaur; Braslow, David Arthur

    2016-01-01

    The current focus on assessing “college and career readiness” raises an empirical question: How do high school tests compare with college admissions tests in predicting performance in college? We explored this using data from the City University of New York and public colleges in Kentucky. These two systems differ in the choice of college admissions test, the stakes for students on the high school test, and demographics. We predicted freshman grade point average (FGPA) from high school GPA an...

  9. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. K NAVIN SAM. Articles written in Sadhana. Volume 42 Issue 2 February 2017 pp 173-185. Wind-driven stand-alone DFIG with battery and pumped hydro storage system · K NAVIN SAM N KUMARESAN N AMMASAI GOUNDEN · More Details Abstract Fulltext PDF. A wind-driven doubly fed ...

  10. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    There have been renewed interests in slip-ring induction machines due to their increasing use in both grid connected and stand-alone wind power generation schemes. Despite the squirrel cage induction generators' advantages of being brushless, low-cost, needing less maintenance and having inherent overload ...

  11. Gilda's Academy

    Science.gov (United States)

    Duplessis, Gilda

    2008-01-01

    Immediately after the devastation of Hurricane Katrina, the author and her partner made a decision to rebuild their child care center as two apartments. However, the city of New Orleans would only approve the location for one dwelling with a child care center. This article describes the author's experiences in rebuilding Gilda's Academy, her child…

  12. Artrodese cervical anterior em três e quatro níveis com dispositivo intersomático não associado à placa cervical Artrodesis cervical anterior en tres y cuatro niveles con dispositivo intersomático no asociado a placa cervical Anterior cervical arthrodesis for three and four levels using stand-alone interbody cages without cervical plates

    Directory of Open Access Journals (Sweden)

    Marcel Luiz Benato

    2009-06-01

    en tercer y cuarto niveles; dolor axial y/o irradiada; con mínimo seis meses de postoperatorio. El criterio de exclusión fue la presencia de inestabilidad cervical traumática. Fueron evaluadas las tasas de consolidación, la presencia de síntomas, la tasa de complicaciones y la posición de los dispositivos intersomáticos (subsidente después de seis meses. RESULTADOS: todos los pacientes obtuvieron consolidación en tres meses, sin embargo, dos pacientes presentaron el fenómeno de subsidente, o sea, migración con consolidación en cifosis, sin alterar los resultados clínicos y la consolidación de la artrodesis a los seis meses de postoperatorio. Los pacientes presentaron mejoría del dolor preoperatorio y solo tres (15% presentaron dolor residual. No hubo complicaciones mayores. El tiempo de hospitalización fue de dos días. No fue utilizada inmovilización rígida en el postoperatorio. CONCLUSIÓN: fue obtenida consolidación con esta técnica en todos los casos. La técnica se mostró segura y promovió buenos resultados radiológicos y clínicos.evaluate the rates of fusion of the anterior cervical discectomy and arthrodesis for three and four levels using interbody cages (stand-alone without cervical plates six months after post-operative. METHODS: from November 2005 to July 2008, 20 patients were treated as proposed. The inclusion criteria were: cervical degenerative disease of three and four levels; axial and/or irradiated pain at least six months of follow-up. The exclusion criteria were: cervical traumatic instability. The fusion rate, clinical symptoms, rate of complications and the implant position were evaluated six months after post-operative. RESULTS: results were favorable in 100% of the patients, with residual pain in two cases. Fusion was found in 100% of the patients, except for two cases with minimum subsidence and fusion in a slight kyphotic position. There were not significant complications. The discharge of the hospital was performed

  13. Freshman Transition and Its Effectiveness on Student Success as Measured by Improved Attendance, Improved Grades, Decreased Discipline Referrals, and Decreased Dropout Rate

    Science.gov (United States)

    Thornsberry, Jana Lea

    2010-01-01

    Research on freshman transition programs suggests the need for a transition program that assists students as they enter high school. Many freshman transition programs consist of a visit from the high school counselors or a tour of the school. These programs do not help meet the needs of many students who will need constant support throughout the…

  14. A Grounded Theory Investigation Into Sophomore Students' Recall of Depression During Their Freshman Year in College: A Pilot Study.

    Science.gov (United States)

    Brandy, Julie M; Kessler, Theresa A; Grabarek, Christina H

    2018-04-17

    Using a grounded theory approach, the current descriptive qualitative design was conducted with sophomore students to understand the meaning participants gave their freshman experiences with depression. Twelve participants were recruited using scripted class announcements across campus. After informed consent, interviews began with the question: What was the experience of your freshman year in college? All interviews were completed with the primary investigator and transcribed verbatim. Interviews were analyzed using constant comparative methodology. Data collection continued until saturation was achieved. Four major categories emerged, including the category of symptoms and emotions. This category included the subcategories expressions of stress, changes in eating habits, sleep issues, and procrastination. Descriptive examples of each were found throughout the interview data. With greater understanding of living with depression as a college freshman, health care and college student affairs professionals will have additional evidence to guide their practices. [Journal of Psychosocial Nursing and Mental Health Services, xx(x),xx-xx.]. Copyright 2018, SLACK Incorporated.

  15. Tinkering self-efficacy and team interaction on freshman engineering design teams

    Science.gov (United States)

    Richardson, Arlisa Labrie

    This study utilizes Bandura's theory of self-efficacy as a framework to examine the development of tinkering skills white working on a freshman engineering design team. The four sources of self-efficacy were analyzed in the context of tinkering within the design team. The research question, 'Does tinkering self-efficacy change for female students during the Freshman Engineering Design class while working on mixed sex teams?', was addressed using quantitative data collection and field observations. Approximately 41 students enrolled in a freshman engineering design class at a public university in the southwest participated by providing self-reports about their tinkering involvement during each design project. In addition, three mixed-sex student teams were observed while working to complete the course design projects. An observation protocol based on Bandura's sources of self efficacy, was used to document tinkering interactions within the three observed teams. The results revealed that Bandura's sources of self-efficacy influenced tinkering involvement. The self-efficacy source, performance accomplishment measured through prior tinkering experience, was the most influential on tinkering involvement. Unlike Bandura's ranking of influence, verbal persuasion was shown to correlate with more tinkering behaviors than the observation of others. The number of females on a team had no impact on tinkering involvement. Tinkering involvement did not change as students progressed from one project to another. However, the competitive nature of the design project appeared to have a negative impact on tinkering involvement and the division of tasks within the team. In addition, a difference was found in the female students' perception of their tinkering involvement and observation of their tinkering involvement. The findings suggest that effective implementation of teamwork including teamwork preparation, more emphasis on the design process and the elimination of competition

  16. oha | academy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    How to combat infectious diseases: The role of Science Academies · Academy Public Lecture and INSA–Leopoldina Lecture by Prof. Jörg Hacker, President, German Academy of Sciences Leopoldina. 4 December, 2017, 4 PM Faculty Hall, Indian Institute ...

  17. Predicting course performance in freshman and sophomore physics courses: Women are more predictable than men

    Science.gov (United States)

    McCammon, Susan; Golden, Jeannie; Wuensch, Karl L.

    This study investigated the extent to which thinking skills and mathematical competency would predict the course performance of freshman and sophomore science majors enrolled in physics courses. Multiple-regression equations revealed that algebra and critical thinking skills were the best overall predictors across several physics courses. Although arithmetic skills, math anxiety, and primary mental abilities scores also correlated with performance, they were redundant with the algebra and critical thinking. The most surprising finding of the study was the differential validity by sex; predictor variables were successful in predicting course performance for women but not for men.

  18. Sports-Oriented Model of Organization of Classes on Physical Education with Freshman

    Directory of Open Access Journals (Sweden)

    Olena Sіnіcina

    2018-03-01

    Full Text Available The article presents the results of questionnaires, which made it possible to determine the priority kinds of sports among the freshmen of the National University of Water Management and Nature Management. Respondents were offered the choice of the following sports: volleyball, basketball, football, mini football, swimming, track and field, table tennis, wrestling, weight sport, arm wrestling, chess, checkers, boxing, fitness. It was found that 33% of male freshman who took part in the study prioritized football above all. Volleyball is the second most common kind of sport among boys (it was chosen by 16% of respondents. The third position (11.4% of respondents was taken by basketball. The least popular (0.6% of the polled is the power kind of sports – weight lifting. Among female freshman, fitness was placed on the first place by 82% of respondents; athletics occupied the second position (4.8%; in the third place was tennis (4.2% of the respondents. The sports-oriented model of organizing the physical education courses provides students of the university who have chosen a certain sport to take part in competitions of different levels.

  19. Academy – Springer Nature chair | About IASc | Indian Academy of ...

    Indian Academy of Sciences (India)

    Academy – Springer Nature Chair. Academy – Springer Nature chair. Background. The Indian Academy of Sciences and Springer mutually agreed to co-publish the Academy's ten journals and executed an agreement in the year 2006. To enhance the scope of its activities, the Academy formed the Academy Trust (tAcT), ...

  20. Compulsive Eating: The Emotional Link of Its Use as a Coping Mechanism for Resident Freshman Female College Students.

    Science.gov (United States)

    Beylerian, Nvair Kadian

    An 18-year old's freshman year in college is not only a test of his or her intellect, but also a test in social skills, adaptability to new living situations, and other conditions. This study examined the link of emotions to compulsive eating and its use as a coping mechanism for female college students. It explores the stresses of the transition…

  1. The Relationship between Listening Strategies Used by Iranian EFL Freshman University Students and Their Listening Proficiency Levels

    Science.gov (United States)

    Bidabadi, Farinaz Shirani; Yamat, Hamidah

    2011-01-01

    The purpose of the current study was to identify Iranian EFL freshman university students' listening proficiency levels and the listening strategies they employed to investigate the relationship between these two variables. A total of 92 freshmen were involved in this study. The Oxford Placement Test was employed to identify the learners'…

  2. Implementation of Collaborative Learning as a High-Impact Practice in a Natural Resources Management Section of Freshman Seminar

    Science.gov (United States)

    McBroom, Matthew; Bullard, Steven; Kulhavy, David; Unger, Daniel

    2015-01-01

    Forestry and environmental science students enrolled in a one credit hour freshman seminar course participated in a land management evaluation and water quality sampling excursion using canoes and water sampling equipment. The purpose of this assessment was to engage students with hands-on, field based education in order to foster connections to…

  3. Promoting Academic Persistence among Racial/Ethnic Minority and European American Freshman and Sophomore Undergraduates: Implications for College Counselors

    Science.gov (United States)

    Rigali-Oiler, Marybeth; Kurpius, Sharon Robinson

    2013-01-01

    Factors influencing persistence decisions among 346 racial/ethnic minority and 813 European American freshman and sophomore undergraduates were explored. Gender and racial/ethnic differences were found in centrality and public regard of racial/ethnic identity. Perceptions of the university environment and self-beliefs predicted persistence…

  4. A Randomized Trial Investigating the Effect of a Brief Lifestyle Intervention on Freshman-Year Weight Gain

    Science.gov (United States)

    Middleton, Kathryn R.; Perri, Michael G.

    2014-01-01

    Objective: The current study was a randomized controlled trial investigating the effect of an innovative, short-term lifestyle intervention on weight gain in female freshman college students. Participants: Ninety-five freshmen were recruited from a large public university in the United States. Methods: Participants completed baseline assessments…

  5. Combining Academic Advising with a Freshman Orientation Course in an Integrated Baccalaureate-Medical Degree Program: Evaluation of the System.

    Science.gov (United States)

    McBeth, Dani L.; Richardson, Susan M.; Cregler, Louis L.; Meyer, Jodie

    2000-01-01

    Evaluated the effects of a freshman seminar incorporating academic advising in an integrated baccalaureate-medical degree program. Found that participating students were more satisfied, and that their biology grades and first-year grade point averages (GPAs) were higher. (EV)

  6. The Chicken Soup Effect: The Role of Recreation and Intramural Participation in Boosting Freshman Grade Point Average

    Science.gov (United States)

    Gibbison, Godfrey A.; Henry, Tracyann L.; Perkins-Brown, Jayne

    2011-01-01

    Freshman grade point average, in particular first semester grade point average, is an important predictor of survival and eventual student success in college. As many institutions of higher learning are searching for ways to improve student success, one would hope that policies geared towards the success of freshmen have long term benefits…

  7. National Academy of Sciences

    Science.gov (United States)

    ... and Irma. Proceedings of the National Academy of Sciences (PNAS) PNAS is one of the world’s most- ... Exchange Evolution Resources Biographical Memoirs National Academy of Sciences About The NAS Mission History Organization Leadership and ...

  8. Toward Meaning and Scientific Thinking in the Traditional Freshman Laboratory: Opening the ``Idea Space''

    Science.gov (United States)

    Allie, Saalih; Demaree, Dedra

    2010-10-01

    Experimentation appears to be an ideal context in which several key aspects of scientific thinking can be addressed. However, the traditional freshman laboratory does not appear to be successful in doing so. This paper argues that this has much to do with the way in which tasks are formulated. We propose a simple descriptive model based on the notion of the "idea space" that can be used to analyze task formulation that can promote meaningful critical thinking. A number of factors that affect the size of the idea space are discussed, such as conceptual metaphor and the perceived nature of questioning from a socio-cultural perspective, described in terms of knowledge and information flow.

  9. Pros and cons of a group webpage design project in a freshman anatomy and physiology course.

    Science.gov (United States)

    Crisp, Kevin M; Jensen, Murray; Moore, Randy

    2007-12-01

    To generate motivation and promote the development of written communication skills, students in a freshman-level anatomy and physiology course for nonmajors created group webpages describing historically important diseases. After the groups had been formed, each individual was assigned specific components of the disease (e.g., causes or treatments), which were subsequently combined into a final product. Interviews and questionnaires were used to document students' previous educational experiences regarding, and attitudes toward, the project. Students learned more about website design than about anatomy and physiology, but students preferred the assignment over traditional term papers. Although most students could find relevant information for this project on the internet, they were uncritical in judging the accuracy of the information they found.

  10. Guiding Students from Consuming Information to Creating Knowledge: A Freshman English Library Instruction Collaboration

    Directory of Open Access Journals (Sweden)

    Carolyn B. Gamtso

    2012-04-01

    Full Text Available In this paper we examine how faculty and librarians’ own approaches to and attitudes toward library tools, as well as their assumptions about student research practices, impede students’ ability to view learning as a recursive, creative, and ongoing inquiry. We propose first that librarians and faculty examine the assumptions of knowledge that characterize their respective university constituencies; second that they dismantle some of the disciplinary boundaries that separate these constituencies; third that they collaborate to craft analytical assignments that stress knowledge as process; and fourth that they transform library instruction from tool-based demonstrations to analytical, problem-based learning exercises. Finally, we describe how we have collaborated to craft a Freshman Composition library instruction session that moves beyond developing students’ information-gathering expertise by focusing on the development of transferable knowledge and critical thinking skills.

  11. Asperger syndrome and DSM-5: a dilemma for a college freshman.

    Science.gov (United States)

    Galligan, Meghan G; Feinstein, Carl; Sulkes, Stephen S; Bisagno, Joan M; Stein, Martin T

    2013-09-01

    Angela is an 18-year-old college freshman who made an appointment with her pediatrician because of academic and social difficulties at college. She was diagnosed with Asperger disorder at age 6 based on difficulties relating to adults and peers, perseverative patterns of interest, and normal language development.She received special education services in middle school to help follow directions and complete assignments. She reports feeling very isolated during this time. In freshman year of high school, she insisted on discontinuing special education and managed with weekly private individual psychotherapy.In sophomore year, Angela learned strategies to get additional help from her teachers about assignments, and her grades improved. Socially, she formed a close friendship with a classmate who was also on the autistic spectrum, and she found a group of friends through this individual. As a senior with an upward grade trajectory and good SAT scores, she was admitted to a competitive 4-year college. In a precollege consult 6 months ago, she was anxious about fitting in.Angela began college classes without accommodations, but she now describes a challenging semester. She has not made many friends. She finds her courses difficult and does not fully understand assignments. She believes her peers dislike her. She thinks she would benefit from receiving note-taking and other services and asks you to document her disability for the college so that she might obtain accommodations.You point out that the DSM-5 eliminates the Asperger category. Angela is concerned. She does not believe that her profile is consistent with autism spectrum disorder, and she fears that being labeled as autistic will be prejudicial at school. Yet she is worried about retaining eligibility for services on the basis of a disability. How do you counsel her?

  12. The Academy Trust

    Indian Academy of Sciences (India)

    user

    The Academy Trust. Agenda. Date: 3rd November 2016. Time: 0900 hrs. Venue: Visitors' Hostel – Auditorium, IISER Bhopal. 0900 – 0930 hrs Welcome and Introduction to the Academy Trust (Chair Academy. Trust or Trustee). Remarks by Director, IISER, Bhopal. Remarks by: Eklavya Trust. 0930 – 1015 hrs Talk by Prof.

  13. American Academy of Audiology

    Science.gov (United States)

    ... Public Relations Toolkit and Hotline to Get Your Practice and Profession into the Media Audiology News 16 Nov A Movement Was Born: ... Academy of Audiology Publications and Resources Audiology Today Journal of the American Academy of Audiology ... About Us Academy Information ...

  14. Why a Steiner Academy?

    Science.gov (United States)

    Avison, Kevin

    2008-01-01

    This article examines the curious position of the Academy model in the English school system and how a potential Hereford Steiner Waldorf Academy might figure in this. It sketches the background to the Steiner movement in the UK and goes on to set out the key aspirations and concerns of Steiner educators regarding an Academy. The article provides…

  15. Indian Academy of Sciences Conference Series | Indian Academy of ...

    Indian Academy of Sciences (India)

    Toggle navigation. Logo of the Indian Academy of Sciences. Indian Academy of Sciences. Home · About IASc · History · Memorandum of Association · Role of the Academy · Statutes · Council · Raman Chair · Jubilee Chair · Academy – Springer Nature chair · Academy Trust · Contact details · Office Staff · Office complaint ...

  16. epsci | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Toggle navigation. Logo of the Indian Academy of Sciences. Indian Academy of Sciences. Home · About IASc · History · Memorandum of Association · Role of the Academy · Statutes · Council · Raman Chair · Jubilee Chair · Academy – Springer Nature chair · Academy Trust · Contact details · Office Staff · Office complaint ...

  17. epubworkshop | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Toggle navigation. Logo of the Indian Academy of Sciences. Indian Academy of Sciences. Home · About IASc · History · Memorandum of Association · Role of the Academy · Statutes · Council · Raman Chair · Jubilee Chair · Academy – Springer Nature chair · Academy Trust · Contact details · Office Staff · Office complaint ...

  18. Diagnostic Test in College Algebra for Freshman Non-Education Students of Westmead International School: Input to Proposed Remedial Activities

    Directory of Open Access Journals (Sweden)

    Jhemson C. Elis

    2013-12-01

    Full Text Available The major thrust of this study is to develop a diagnostic test in college algebra to know the level of performance in College Algebra of non – education freshman students of Westmead International School through the use of a diagnostic test. The researcher used the descriptive method of research. The level of performance of freshman non – education students of Westmead International School in Algebraic operation has a mean of 80.66 with the highest score of 88 percent and lowest score of 68, while 22 or 31.43 percent had an average performance ranging from 79 - 84. This indicates that students had average mathematical skills and knowledge acquired from their mathematics foundation during high school. The level of performance of freshman non – education students of Westmead International School in arithmetic operation has 77.78 of the mean score with the highest score of 94 and lowest score of 68, which indicates that the students have difficulties in some areas in arithmetic operations. There was a significant relationship between mathematics foundation and the level of performance of the students. The output made by the researcher was a set of Remedial Activities in College Algebra, which is composed of different topics based on the result of the study and on the suggestions of the college instructors of Westmead International School based on their observation. The topics were operation on integers, operation involving polynomials, and special products. It was recommended that the freshman college students need to take the diagnostic test in College Algebra to determine their level of performance. If they fail in the diagnostic test, they will take Math Plus (Basic Mathematics instead of College Algebra. The students with good performance in the diagnostic test will take College Algebra.

  19. Freshman College Students’ Reasons for Enrolling in and Anticipated Benefits from a Basic College Physical Education Activity Course

    OpenAIRE

    Lackman, Jeremy; Smith, Matthew Lee; McNeill, Elisa Beth

    2015-01-01

    Background Given the rise in US obesity rates in adulthood, efforts are needed to assess physical activity engagement during the college years as a strategy to promote a lifetime of being physically active. This study identifies the reasons incoming college freshman enrolled in basic physical education activity courses (BPEAC) and the perceived benefits they anticipated receiving as a result of course participation. Methods Data collected from 302 college freshmen in September 2013...

  20. Houston Pre-Freshman Enrichment Program (Houston PREP). Final report, June 9, 1997--July 25, 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    The 1997 Houston Pre-Freshman Enrichment Program (PREP) was conducted at the campus of the University of Houston-Downtown from June 9 to July 25, 1997. Program participants were recruited from the Greater Houston Area. All participants were identified as high-achieving students with an interest in learning about the engineering and science professions. The goal of the program was to better prepare our pre-college youth prior to entering college as mathematics, science and engineering majors. The program participants were middle school and high school students from the Aldine, Alief, Channel View, Clear Creek, Cypress-Fairbanks, Fort Bend, Galena Park, Houston, Humble, Katy, Klein, North Forest, Pasadena, Private, and Spring Branch Independent School Districts. Of the 194 students starting the program, 165 students were from economically and socially disadvantage groups under-represented in the engineering and science professions, and 118 of the 194 were women. Our First Year group for 1997 composed of 96% minority and women students. Second and Third Year students combined were 96% minority or women. With financial support from the Center for Computational Sciences and Advanced Distributed Simulation, the Fourth Year Program was added to PREP this year. Twelve students completed the program (83% minority or women).

  1. Predicting Freshman Grade Point Average From College Admissions Test Scores and State High School Test Scores

    Directory of Open Access Journals (Sweden)

    Daniel Koretz

    2016-09-01

    Full Text Available The current focus on assessing “college and career readiness” raises an empirical question: How do high school tests compare with college admissions tests in predicting performance in college? We explored this using data from the City University of New York and public colleges in Kentucky. These two systems differ in the choice of college admissions test, the stakes for students on the high school test, and demographics. We predicted freshman grade point average (FGPA from high school GPA and both college admissions and high school tests in mathematics and English. In both systems, the choice of tests had only trivial effects on the aggregate prediction of FGPA. Adding either test to an equation that included the other had only trivial effects on prediction. Although the findings suggest that the choice of test might advantage or disadvantage different students, it had no substantial effect on the over- and underprediction of FGPA for students classified by race-ethnicity or poverty.

  2. Talent Management in Academies

    Science.gov (United States)

    Davies, Brent; Davies, Barbara J.

    2010-01-01

    Purpose: Academies are semi-autonomous schools set up outside the normal local government structures with sponsors from business and charity groups to create new and innovative ways of creating and sustaining school transformation. The aim of this paper is to assist in a strategic conversation within the academy movement on talent development.…

  3. academy public lecture

    Indian Academy of Sciences (India)

    Ethical Guidelines and Procedures document. Posted on 17 January 2017. A revised version of the document 'Scientific Values: Ethical Guidelines and Procedures' has been produced by the Academy's Panel on Scientific Values. For more details, see the Academy Committee on Scientific Values page.

  4. The Academy Trust

    Indian Academy of Sciences (India)

    The Academy Trust (tAcT) was set up in August 2014 as a non-governmental entity under the auspices of the Indian Academy of Sciences (IASc), Bengaluru. Working closely with some of the most distinguished scientific minds in the country through the Fellowship of the IASc, the Trust hopes to bring about a tangible ...

  5. Simulation of a stand-alone renewable hydrogen system for residential supply

    Directory of Open Access Journals (Sweden)

    Martín Hervello

    2014-01-01

    Full Text Available La simulación por ordenador es un primer paso lógico previo a la realización de un proyecto de una construcción física además de ser una herramienta para el diseño de redes de energía. Los sistemas combinados son una solución para mejorar la disponibilidad de la energía suministrada con medios renovables. El principal inconveniente de las fuentes de energías renovables es su naturaleza altamente estacional, con grandes variaciones en el tiempo que pueden impedir el uso como base de consumo y limitar las horas de máxima demanda. El objetivo de este trabajo es realizar simulaciones para comprobar la autosuficiencia energética de una vivienda unifamiliar en base a energías renovables (eólica, solar-fotovoltaica utilizando como medio de almacenamiento un sistema híbrido de baterías e hidrógeno. Para ello se ha utilizado el programa Simulink®-Matlab® teniendo en cuenta los datos meteorológicos proporcionados por METEO-Galicia. El modelo puede ser aplicado para determinar la viabilidad de implementar una red energética en regiones específicas, y predecir el flujo de energía y el comportamiento del sistema durante todo el año.

  6. X-ray microbeam stand-alone facility for cultured cells irradiation

    International Nuclear Information System (INIS)

    Bożek, Sebastian; Bielecki, Jakub; Wiecheć, Anna; Lekki, Janusz; Stachura, Zbigniew; Pogoda, Katarzyna; Lipiec, Ewelina; Tkocz, Konrad; Kwiatek, Wojciech M.

    2017-01-01

    Highlights: • An X-ray microbeam line for irradiation of living cultured cells was constructed. • A step by step explanation of working principles with engineering details, procedures and calculations is presented. • A model of beam and cell interaction is presented. • A method of uniform irradiation of living cells with an exact dose per a cell is presented. • Results of preliminary experiments are presented. - Abstract: The article describes an X-ray microbeam standalone facility dedicated for irradiation of living cultured cells. The article can serve as an advice for such facilities construction, as it begins from engineering details, through mathematical modeling and experimental procedures, ending up with preliminary experimental results and conclusions. The presented system consists of an open type X-ray tube with microfocusing down to about 2 μm, an X-ray focusing system with optical elements arranged in the nested Kirckpatrick-Baez (or Montel) geometry, a sample stand and an optical microscope with a scientific digital CCD camera. For the beam visualisation an X-ray sensitive CCD camera and a spectral detector are used, as well as a scintillator screen combined with the microscope. A method of precise one by one irradiation of previously chosen cells is presented, as well as a fast method of uniform irradiation of a chosen sample area. Mathematical models of beam and cell with calculations of kerma and dose are presented. The experiments on dose-effect relationship, kinetics of DNA double strand breaks repair, as well as micronuclei observation were performed on PC-3 (Prostate Cancer) cultured cells. The cells were seeded and irradiated on Mylar foil, which covered a hole drilled in the Petri dish. DNA lesions were visualised with γ-H2AX marker combined with Alexa Fluor 488 fluorescent dye.

  7. Perancangan Photovoltaic Stand Alone Sebagai Catu Daya Pada Base Transceiver Station Telekomunikasi Di Pulau Nusa Penida

    Directory of Open Access Journals (Sweden)

    I P Eka Indrawan

    2013-06-01

    Full Text Available Salah satu perangkat dalam jaringan komunikasi seluler adalah BTS (Base Transceiver Station. BTS yang ada di pulau Nusa Penida adalah BTS Nusa Penida dengan alamat desa kutampi dengan luas 500 m2. Sistem kelistrikan BTS  Nusa Penida dipasok oleh PLN dan genset,  dimana pada saat terjadi pemadaman energi listrik pada umumnya mempergunakan genset sebagai sumber energi listrik. Penggunaan genset mengakibatkan biaya operasional sangat tinggi, untuk itu diperlukan sumber lain yang lebih efisien. Besarnya potensi insolasi sinar harian matahari di Nusa penida, bisa sebagai  alternatif lain untuk sumber energi listrik dimana energi matahari bisa sebagai energi terbarukan untuk catu daya tambahan di BTS Nusa Penida yang pada akhirnya dapat menjaga  kestabilan suplai energi listrik ke BTS dan akses masyarakat terhadap informasi melalui seluler menjadi tidak terganggu. PV (Photovoltaic merupakan salah satu energi terbarukan yang dapat digunakan sebagai energi terbarukan untuk catu daya tambahan di BTS. Sistem PV yang dikembangkan untuk mensuplai energi listrik di BTS direncanakan sebesar 25%, adalah sistem PV yang hybrid dengan suplai listrik PLN. Besar daya PV yang dibangkitkan untuk mensuplai energi listrik di BTS adalah 9 kWp, yang dihasilkan dari panel PV sebanyak 45 panel dengan kapasitas panel PV adalah 200Wp dan kapasitas baterai yang akan digunakan adalah 3.800 Ah dengan total baterai 16. Analisis kelayakan investasi PV tanpa baterai dan PV dengan baterai yang dilakukan dengan menggunakan NPV, PI dan DPP menunjukkan hasil bahwa investasi PV layak untuk dilaksanakan. Untuk nilai NPV dan PI didapatkan kedua hasil investasi (> 0. Sedangkan untuk DPP didapatkan kedua hasil investasi dihasilkan lebih kecil dari periode umur proyek yang sudah ditetapkan, yaitu selama 25 tahun.

  8. Fuzzy Secondary Controller for Autonomous Stand-alone and Grid-connected AC Microgrid

    DEFF Research Database (Denmark)

    Neves, Rodolpho V. A.; Machado, Ricardo Q.; Oliveira, Vilma A.

    2016-01-01

    The present paper adresses the AC microgrid control issue using the hierarchical control structure and droop controllers for load sharing. Once the droop controllers impose an operation with frequency and voltage deviations, depending on the load and droop parameters, a hierarchical control...... structure must be added to change the droop controller operating points. The hierarchical controllers operate with local measurements and shared signals from communication links among the distributed generation systems connected to the microgrid. Depending on the geographical size of the microgrid......, the communication links can be economically unviable. This paper thus proposes a fuzzy secondary controller for AC microgrids to reduce the link communication dependency by using only local measurements. The simulation results show that the deviations as happened with the conventional secondary controllers can...

  9. Implicit, Stand-Alone or Integrated Skills Education for Undergraduates: A Longitudinal Analysis of Programme Outcomes

    Science.gov (United States)

    MacVaugh, Jason; Jones, Anna; Auty, Stephanie

    2014-01-01

    This paper reports the findings of a longitudinal investigation into the effectiveness of skills education programmes within business and management undergraduate degree courses. During the period between 2005 and 2011, a large business school in the south-west of England was developed and implemented two distinct approaches to skills education.…

  10. Analysis of a small wind-hydrogen stand-alone hybrid energy system

    International Nuclear Information System (INIS)

    Khan, M.J.; Iqbal, M.T.

    2009-01-01

    In this article, detailed modeling, simulation, and analysis of an isolated wind-hydrogen hybrid energy system is presented. Dynamic nonlinear models of all the major subsystems are developed based on sets of empirical and physical relationships. The performance of the integrated hybrid energy system is then analyzed through digital simulation. Design of dynamic controllers and supervisory control schemes are also presented. Expected behaviors during sudden load variation, wind speed change and hydrogen pressure drop are observed under both stochastic and step-variation conditions. MATLAB-Simulink TM is employed for dynamic system modeling. This exercise, in essence, outlines a process of wind-hydrogen off-grid system control synthesis and performance evaluation. Finally, results of the analysis are summarized, limitations of the simulation study are identified, and scope for future work is indicated.

  11. Comparison of two stand-alone CADe systems at multiple operating points

    Science.gov (United States)

    Sahiner, Berkman; Chen, Weijie; Pezeshk, Aria; Petrick, Nicholas

    2015-03-01

    Computer-aided detection (CADe) systems are typically designed to work at a given operating point: The device displays a mark if and only if the level of suspiciousness of a region of interest is above a fixed threshold. To compare the standalone performances of two systems, one approach is to select the parameters of the systems to yield a target false-positive rate that defines the operating point, and to compare the sensitivities at that operating point. Increasingly, CADe developers offer multiple operating points, which necessitates the comparison of two CADe systems involving multiple comparisons. To control the Type I error, multiple-comparison correction is needed for keeping the family-wise error rate (FWER) less than a given alpha-level. The sensitivities of a single modality at different operating points are correlated. In addition, the sensitivities of the two modalities at the same or different operating points are also likely to be correlated. It has been shown in the literature that when test statistics are correlated, well-known methods for controlling the FWER are conservative. In this study, we compared the FWER and power of three methods, namely the Bonferroni, step-up, and adjusted step-up methods in comparing the sensitivities of two CADe systems at multiple operating points, where the adjusted step-up method uses the estimated correlations. Our results indicate that the adjusted step-up method has a substantial advantage over other the two methods both in terms of the FWER and power.

  12. PV LED ENGINE characterization lab for stand alone light-to-light systems

    DEFF Research Database (Denmark)

    Poulsen, Peter Behrensdorff; Thorsteinsson, Sune; Lindén, Johannes

    2015-01-01

    PV-powered lighting systems, light-to-light systems (L2L), offer outdoor lighting where it is elsewhere cumbersome to enable lighting. Application of these systems at high latitudes, where the difference in day length between summer and winter is large and the solar energy is low requires smart...... dimming functions for reliable lighting. A barrier for exploiting use of standalone solar lighting for the urban environment seem to be lack of knowledge and lack of available tools for proper dimensioning. In this work the development of powerful dimensioning tool is described and initial measurements...

  13. Particulate matter concentrations in residences: an intervention study evaluating stand-alone filters and air conditioners.

    Science.gov (United States)

    Batterman, S; Du, L; Mentz, G; Mukherjee, B; Parker, E; Godwin, C; Chin, J-Y; O'Toole, A; Robins, T; Rowe, Z; Lewis, T

    2012-06-01

    This study, a randomized controlled trial, evaluated the effectiveness of free-standing air filters and window air conditioners (ACs) in 126 low-income households of children with asthma. Households were randomized into a control group, a group receiving a free-standing HEPA filter placed in the child's sleeping area, and a group receiving the filter and a window-mounted AC. Indoor air quality (IAQ) was monitored for week-long periods over three to four seasons. High concentrations of particulate matter (PM) and carbon dioxide were frequently seen. When IAQ was monitored, filters reduced PM levels in the child's bedroom by an average of 50%. Filter use varied greatly among households and declined over time, for example, during weeks when pollutants were monitored, filter use was initially high, averaging 84±27%, but dropped to 63±33% in subsequent seasons. In months when households were not visited, use averaged only 34±30%. Filter effectiveness did not vary in homes with central or room ACs. The study shows that measurements over multiple seasons are needed to characterize air quality and filter performance. The effectiveness of interventions using free-standing air filters depends on occupant behavior, and strategies to ensure filter use should be an integral part of interventions. Environmental tobacco smoke (ETS) increased particulate matter (PM) levels by about 14 μg/m3 and was often detected using ETS-specific tracers despite restrictions on smoking in the house as reported on questionnaires administered to caregivers. PM concentrations depended on season, filter usage, relative humidity, air exchange ratios, number of children, outdoor PM levels, sweeping/dusting, and presence of a central air conditioner (AC). Free-standing air filters can be an effective intervention that provides substantial reductions in PM concentrations if the filters are used. However, filter use was variable across the study population and declined over the study duration, and thus strategies are needed to encourage and maintain use of filters. The variability in filter use suggests that exposure misclassification is a potential problem in intervention studies using filters. The installation of a room AC in the bedroom, intended to limit air exchange ratios, along with an air filter, did not lower PM levels more than the filter alone. © 2011 John Wiley & Sons A/S.

  14. Rancang Bangun Stand-Alone Automatic Rain Gauge (ARG Berbasis Panel Surya

    Directory of Open Access Journals (Sweden)

    Zaenal Arifin

    2017-11-01

    Full Text Available Automatic Rain Gauge (ARG digunakan untuk memonitor curah hujan di suatu wilayah. ARG bekerja dengan menggunakan mikrokontroller sebagai prosesing unit dan merupakan sebuah embedded sistem (sistem yang berdiri sendiri. ARG tidak hanya diletakan pada stasiun pemantauan Badan Meteorologi, Klimatologi dan Geofisika (BMKG, namun ARG juga diletakan di daerah terpencil yang jauh dari jaringan listrik. Hal tersebut menjadi masalah karena ARG membutuhkan sumber energi listrik untuk dapat bekerja. Berdasarkan spesifikasinya, ARG membutuhkan mikrokontroller yang rendah dalam penggunaan daya serta memiliki cukup memory sebagai tempat penyimpanan data sementara. Salah satu jenis mikrokrontroller yang memenuhi spesifikasi tersebut adalah MSP430FR5969. Dari penelitian yang telah dilakukan, didapatkan hasil konsumsi daya rata – rata yang dibutuhkan oleh ARG sebesar 0.23 watt. Dengan memanfaatkan panel surya sebesar 20 watt yang dilengkapi dengan maximum power point tracking (MPPT sebagai sumber energi listrik, dapat menghasilkan daya 5,5 watt hingga 7,2 watt. Dengan perbandingan data konsumsi energi dan data yang dihasilkan dari solar panel panel, maka ARG memiliki sumber listrik mandiri untuk memenuhi kebutuhannya.

  15. Continuous stand-alone controllable aerosol/cloud droplet dryer for atmospheric sampling

    Science.gov (United States)

    Sjogren, S.; Frank, G. P.; Berghof, M. I. A.; Martinsson, B. G.

    2013-02-01

    We describe a general-purpose dryer designed for continuous sampling of atmospheric aerosol, where a specified relative humidity (RH) of the sample flow (lower than the atmospheric humidity) is required. It is often prescribed to measure the properties of dried aerosol, for instance for monitoring networks. The specific purpose of our dryer is to dry cloud droplets (maximum diameter approximately 25 μm, highly charged, up to 5 × 102 charges). One criterion is to minimise losses from the droplet size distribution entering the dryer as well as on the residual dry particle size distribution exiting the dryer. This is achieved by using a straight vertical downwards path from the aerosol inlet mounted above the dryer, and removing humidity to a dry, closed loop airflow on the other side of a semi-permeable GORE-TEX membrane (total area 0.134 m2). The water vapour transfer coefficient, k, was measured to be 4.6 × 10-7 kg m-2 s-1% RH-1 in the laboratory (temperature 294 K) and is used for design purposes. A net water vapour transfer rate of up to 1.2 × 10-6 kg s-1 was achieved in the field. This corresponds to drying a 5.7 L min-1 (0.35 m3 h-1) aerosol sample flow from 100% RH to 27% RH at 293 K (with a drying air total flow of 8.7 L min-1). The system was used outdoors from 9 May until 20 October 2010, on the mountain Brocken (51.80° N, 10.67° E, 1142 m a.s.l.) in the Harz region in central Germany. Sample air relative humidity of less than 30% was obtained 72% of the time period. The total availability of the measurement system was >94% during these five months.

  16. Continuous stand-alone controllable aerosol/cloud droplet dryer for atmospheric sampling

    Directory of Open Access Journals (Sweden)

    S. Sjogren

    2013-02-01

    Full Text Available We describe a general-purpose dryer designed for continuous sampling of atmospheric aerosol, where a specified relative humidity (RH of the sample flow (lower than the atmospheric humidity is required. It is often prescribed to measure the properties of dried aerosol, for instance for monitoring networks. The specific purpose of our dryer is to dry cloud droplets (maximum diameter approximately 25 μm, highly charged, up to 5 × 102 charges. One criterion is to minimise losses from the droplet size distribution entering the dryer as well as on the residual dry particle size distribution exiting the dryer. This is achieved by using a straight vertical downwards path from the aerosol inlet mounted above the dryer, and removing humidity to a dry, closed loop airflow on the other side of a semi-permeable GORE-TEX membrane (total area 0.134 m2.

    The water vapour transfer coefficient, k, was measured to be 4.6 × 10-7 kg m−2 s−1% RH−1 in the laboratory (temperature 294 K and is used for design purposes. A net water vapour transfer rate of up to 1.2 × 10-6 kg s−1 was achieved in the field. This corresponds to drying a 5.7 L min−1 (0.35 m3 h−1 aerosol sample flow from 100% RH to 27% RH at 293 K (with a drying air total flow of 8.7 L min−1. The system was used outdoors from 9 May until 20 October 2010, on the mountain Brocken (51.80° N, 10.67° E, 1142 m a.s.l. in the Harz region in central Germany. Sample air relative humidity of less than 30% was obtained 72% of the time period. The total availability of the measurement system was >94% during these five months.

  17. The children left to stand alone | Roalkvam | African Journal of AIDS ...

    African Journals Online (AJOL)

    Drawing upon ethnographic fieldwork in Seke, a semi-rural area outside Harare, Zimbabwe, this paper explores the social mechanism behind the seeming invisibility of children left on their own and how this form of 'invisibility' challenges established notions of childhood, parenthood, kinship, and community. It argues that ...

  18. Investigation of heating and cooling in a stand-alone high temperature PEM fuel cell system

    International Nuclear Information System (INIS)

    Zhang, Caizhi; Yu, Tao; Yi, Jun; Liu, Zhitao; Raj, Kamal Abdul Rasheedj; Xia, Lingchao; Tu, Zhengkai; Chan, Siew Hwa

    2016-01-01

    Highlights: • Heating-up and cooling-down processes of HT-PEMFC are the mainly interested topics. • Dynamic behaviours, power and energy demand of the heating and cooling was studied. • Hybrid system based on LiFeYPO 4 battery for heating and cooling is built and tested. • The concept of combining different heating sources together is recommended. - Abstract: One key issue pertaining to the cold-start of High temperature PEM fuel cell (HT-PEMFC) is the requirement of high amount of thermal energy for heating up the stack to a temperature of 120 °C or above before it can generate electricity. Furthermore, cooling down the stack to a certain temperature (e.g. 50 °C) is necessary before stopping. In this study, the dynamic behaviours, power and energy demand of a 6 kW liquid cooled HT-PEMFC stack during heating-up, operation and cooling-down were investigated experimentally. The dynamic behaviours of fuel cell under heating-up and cooling-down processes are the mainly interested topics. Then a hybridisation of HT-PEMFC with Li-ion battery to demonstrate the synergistic effect on dynamic behaviour was conducted and validated for its feasibility. At last, the concept of combining different heating sources together is analysed to reduce the heating time of the HT-PEMFC as well.

  19. Integrated fuel-coolant interaction code: Assessment of stand-alone version 6.0

    International Nuclear Information System (INIS)

    Davis, F.J. Jr.

    1994-01-01

    This paper discusses the operational assessment of IFCI 6.0 against a small suite of experiments representative of the existing fuel-coolant interaction (FCI) database. The simulations should shakedown any obvious problems and demonstrate the functionality of the models contained within FCI for all phases of FCI phenomena. It was anticipated that these simulations should reasonably represent the experimental data. The IFCI 6.0 simulations were not expected, or required, to exactly reproduce the experimental results. IFCI 6.0 was assessed against a generic FITS-type pouring mode experiment, a FARO quenching experiment, and the IET-8 A ampersand B experiments to: (1) demonstrate that the code can reliably reproduce the results of the previous versions of the ifci code; (2) demonstrate the capability of qualitatively simulating all phases of fuel-coolant interactions (FCIs), including explosive cases, and; (3) identify shortcomings and areas for code enhancement

  20. New Scheme for Seamless Operation for Stand-Alone Power Systems

    Directory of Open Access Journals (Sweden)

    Hyun-Jun Kim

    2016-06-01

    Full Text Available On remote islands photovoltaic (PV panels with battery energy storage systems (BESSs supply electric power to customers in parallel operation with engine generators (EGs to reduce fuel consumption and environmental burden. A BESS operates in voltage control mode when it supplies power to loads alone, while it operates in current control mode when it supplies power to loads in parallel with the EG. This paper proposes a smooth mode change of the BESS from current control to voltage control by using initial value at the output of integral part in the voltage controller, and a smooth mode change from voltage control to current control by tracking the EG output voltage to the BESS output voltage using a phase-locked loop (PLL. The feasibility of the proposed scheme was verified through computer simulations and experiments with a scaled prototype.

  1. Development of stand-alone risk assessment software for optimized maintenance planning of power plant facilities

    International Nuclear Information System (INIS)

    Choi, Woo Sung; Song, Gee Wook; Kim, Bum Shin; Chang, Sung Ho; Lee, Sang Min

    2015-01-01

    Risk-Risk-based inspection (RBI) has been developed in order to identify risky equipment that can cause major accidents or damages in large-scale plants. This assessment evaluates the equipment's risk, categorizes their priorities based on risk level, and then determines the urgency of their maintenance or allocates maintenance resources. An earlier version of the risk-based assessment software is already installed within the equipment management system; however, the assessment is based on examination by an inspector, and the results can be influenced by his subjective judgment, rather than assessment being based on failure probability. Moreover, the system is housed within a server, which limits the inspector's work space and time, and such a system can be used only on site. In this paper, the development of independent risk-based assessment software is introduced; this software calculates the failure probability by an analytical method, and analyzes the field inspection results, as well as inspection effectiveness. It can also operate on site, since it can be installed on an independent platform, and has the ability to generate an I/O function for the field inspection results regarding the period for an optimum maintenance cycle. This program will provide useful information not only to the field users who are participating in maintenance, but also to the engineers who need to decide whether to extend the life cycle of the power machinery or replace only specific components

  2. Last Stand-alone Beam Test of the Hadronic End-cap Calorimeter (HEC) Finished.

    CERN Multimedia

    Oberlack, H

    One quarter of all 134 HEC modules are tested with electron, pion and muon beams: two "partial HEC wheels", three HEC1 modules and three HEC2 modules, are used in a standard setup using the HEC cryostat in the H6 beam line. The picture shows a view of the set-up in the cryostat during the installation. MC results show that in this setup the energy leakage is well under control - well below 5 %. In addition, the other three quarters of modules are tested in technical cold tests. Using calibration signals, a detailed test of the cabling, cold electronics, crosstalk and noise performance is being done. The beam tests started with four prototype modules per run in '97, when technological optimization was still the key issue. From '98 onwards, modules of the "module 0" type have been tested, typically in two run periods per year. Finally in '99 the series production has started, with first beam test of series modules in 2000. Since then 57 series modules have been cold tested, 24 of them actually in beam tests. T...

  3. Stand-alone error characterisation of microwave satellite soil moisture using a Fourier method

    Science.gov (United States)

    Error characterisation of satellite-retrieved soil moisture (SM) is crucial for maximizing their utility in research and applications in hydro-meteorology and climatology. Error characteristics can provide insights for retrieval development and validation, and inform suitable strategies for data fus...

  4. Development of a stand-alone microcomputer based DOE contractor generic radiation worker safety course

    International Nuclear Information System (INIS)

    Klos, D.B.; Gardner, P.R.

    1985-01-01

    Westinghouse Hanford Company (WHC) has developed Computer Based Training (CBT) materials for radiation and industrial safety. First released for general Fast Flux Test Facility in November, 1984. This course has now been taken by nearly 350 people. Completion times for new personnel average around eight hours. The next project undertaken was construction of a Radiation Worker Safety course generic enough for use by all contractors at the Hanford site. The design process of the Hanford site course indicated that the quantity of ''DOE common material'' may be sufficient to warrant consideration of a larger target population. Specifically, the course will be designed to run on an IBM-PC or compatible computer having 256K RAM, a standard IBM color graphics card or equivalent, a color graphics monitor, and two floppy disk drives or one hard disk. The target student population includes those who routinely work in Radiation Areas, especially crafts people. We are not targeting Health Physics personnel, except, possibly, for introductory training, nor are we directing the course toward ''casual'' or escorted workers

  5. An ArcGIS analysis of Stand-alone GPS quality for Road Pricing

    DEFF Research Database (Denmark)

    Zabic, Martina

    2006-01-01

    quality and reliability is adequate for implementation of a road pricing system. The GPS log files was imported into ArcGIS and analyzed in relation to the digital road network and the density of the high rise areas in order to examine where the high buildings and narrow street canyons causes too many...

  6. Microprocessor controlled limitation system for a stand-alone freely movable treatment couch

    NARCIS (Netherlands)

    van de Vondel, I.; Coppens, L.; Verellen, D.; Bel, A.; Linthout, N.; de Beukeleer, M.; van den Berge, D.; Storme, G.

    1998-01-01

    Because of the capability of free movement in the treatment room, we recently introduced a Hercules treatment couch on one of our linear accelerators. One of the advantages of this couch is that it allows for a more flexible way of patient setup and that it can be moved entirely out of the way to

  7. MPA Portable: A Stand-Alone Software Package for Analyzing Metaproteome Samples on the Go.

    Science.gov (United States)

    Muth, Thilo; Kohrs, Fabian; Heyer, Robert; Benndorf, Dirk; Rapp, Erdmann; Reichl, Udo; Martens, Lennart; Renard, Bernhard Y

    2018-01-02

    Metaproteomics, the mass spectrometry-based analysis of proteins from multispecies samples faces severe challenges concerning data analysis and results interpretation. To overcome these shortcomings, we here introduce the MetaProteomeAnalyzer (MPA) Portable software. In contrast to the original server-based MPA application, this newly developed tool no longer requires computational expertise for installation and is now independent of any relational database system. In addition, MPA Portable now supports state-of-the-art database search engines and a convenient command line interface for high-performance data processing tasks. While search engine results can easily be combined to increase the protein identification yield, an additional two-step workflow is implemented to provide sufficient analysis resolution for further postprocessing steps, such as protein grouping as well as taxonomic and functional annotation. Our new application has been developed with a focus on intuitive usability, adherence to data standards, and adaptation to Web-based workflow platforms. The open source software package can be found at https://github.com/compomics/meta-proteome-analyzer .

  8. Minimally invasive glaucoma surgery as primary stand-alone surgery for glaucoma.

    Science.gov (United States)

    Kerr, Nathan M; Wang, Jing; Barton, Keith

    2017-05-01

    Recently, many new devices and procedures have been developed to lower intraocular pressure in a less invasive and purportedly safer manner than traditional glaucoma surgery. These new devices might encourage an earlier transition to surgery and reduce the long-term commitment to topical glaucoma medications with their associated compliance and intolerance issues. Although often seen as an adjunct to cataract surgery, a growing body of evidence suggests that primary minimally invasive glaucoma surgery may be a viable initial treatment option. New studies have shown that primary ab interno trabeculectomy (Trabectome, NeoMedix Inc., Tustin, CA, USA), trabecular micro-bypass stent insertion (iStent and iStent Inject, Glaukos Corporation, Laguna Hills, CA, USA), canalicular scaffolding (Hydrus, Invantis Inc., Irvine CA, USA), the ab interno gel Implant (XEN, Allergan, Dublin, Ireland) or supraciliary stenting (CyPass Micro-Stent, Alcon, Fort Worth, TX, USA) may lower the lowering intraocular pressure and/or topical medication burden in phakic or pseudophakic patients with glaucoma. This effect seems to last at least 12 months but reliable cost-effectiveness and quality of life indicators have not yet been established by investigator-initiated randomized trials of sufficient size and duration. © 2016 Royal Australian and New Zealand College of Ophthalmologists.

  9. Sizing and economic analysis of stand alone photovoltaic system with hydrogen storage

    Science.gov (United States)

    Nordin, N. D.; Rahman, H. A.

    2017-11-01

    This paper proposes a design steps in sizing of standalone photovoltaic system with hydrogen storage using intuitive method. The main advantage of this method is it uses a direct mathematical approach to find system’s size based on daily load consumption and average irradiation data. The keys of system design are to satisfy a pre-determined load requirement and maintain hydrogen storage’s state of charge during low solar irradiation period. To test the effectiveness of the proposed method, a case study is conducted using Kuala Lumpur’s generated meteorological data and rural area’s typical daily load profile of 2.215 kWh. In addition, an economic analysis is performed to appraise the proposed system feasibility. The finding shows that the levelized cost of energy for proposed system is RM 1.98 kWh. However, based on sizing results obtained using a published method with AGM battery as back-up supply, the system cost is lower and more economically viable. The feasibility of PV system with hydrogen storage can be improved if the efficiency of hydrogen storage technologies significantly increases in the future. Hence, a sensitivity analysis is performed to verify the effect of electrolyzer and fuel cell efficiencies towards levelized cost of energy. Efficiencies of electrolyzer and fuel cell available in current market are validated using laboratory’s experimental data. This finding is needed to envisage the applicability of photovoltaic system with hydrogen storage as a future power supply source in Malaysia.

  10. MIRNA-DISTILLER: A Stand-Alone Application to Compile microRNA Data from Databases

    OpenAIRE

    Rieger, Jessica K.; Bodan, Denis A.; Zanger, Ulrich M.

    2011-01-01

    MicroRNAs (miRNA) are small non-coding RNA molecules of ∼22 nucleotides which regulate large numbers of genes by binding to seed sequences at the 3′-untranslated region of target gene transcripts. The target mRNA is then usually degraded or translation is inhibited, although thus resulting in posttranscriptional down regulation of gene expression at the mRNA and/or protein level. Due to the bioinformatic difficulties in predicting functional miRNA binding sites, several publically available d...

  11. Numerical simulation of flow through cascade in wind tunnel test section and stand-alone configurations

    Czech Academy of Sciences Publication Activity Database

    Fořt, J.; Fürst, J.; Halama, J.; Hric, V.; Louda, P.; Luxa, Martin; Šimurda, David

    2018-01-01

    Roč. 319, February (2018), s. 633-646 ISSN 0096-3003 Institutional support: RVO:61388998 Keywords : numerical simulation * experimental investigation * transonic flow Subject RIV: BK - Fluid Dynamics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.738, year: 2016 https://www. science direct.com/ science /article/pii/S0096300317305015

  12. Development of Stand-Alone Risk Assessment Software for Optimized Maintenance Planning of Power Plant Facilities

    International Nuclear Information System (INIS)

    Choi, Woo Sung; Song, Gee Wook; Kim, Bum Shin; Chang, Sung Ho; Lee, Sang Min

    2015-01-01

    Risk-Risk-based inspection (RBI) has been developed in order to identify risky equipment that can cause major accidents or damages in large-scale plants. This assessment evaluates the equipment s risk, categorizes their priorities based on risk level, and then determines the urgency of their maintenance or allocates maintenance resources. An earlier version of the risk-based assessment software is already installed within the equipment management system; however, the assessment is based on examination by an inspector, and the results can be influenced by his subjective judgment, rather than assessment being based on failure probability. Moreover, the system is housed within a server, which limits the inspector s work space and time, and such a system can be used only on site. In this paper, the development of independent risk-based assessment software is introduced; this software calculates the failure probability by an analytical method, and analyzes the field inspection results, as well as inspection effectiveness. It can also operate on site, since it can be installed on an independent platform, and has the ability to generate an I/O function for the field inspection results regarding the period for an optimum maintenance cycle. This program will provide useful information not only to the field users who are participating in maintenance, but also to the engineers who need to decide whether to extend the life cycle of the power machinery or replace only specific components

  13. A stand-alone track reconstruction algorithm for the scintillating fibre tracker at the LHCb upgrade

    CERN Multimedia

    Quagliani, Renato

    2017-01-01

    The LHCb upgrade detector project foresees the presence of a scintillating fiber tracker (SciFi) to be used during the LHC Run III, starting in 2020. The instantaneous luminosity will be increased up to $2\\times10^{33}$, five times larger than in Run II and a full software event reconstruction will be performed at the full bunch crossing rate by the trigger. The new running conditions, and the tighter timing constraints in the software trigger, represent a big challenge for track reconstruction. This poster presents the design and performance of a novel algorithm that has been developed to reconstruct track segments using solely hits from the SciFi. This algorithm is crucial for the reconstruction of tracks originating from long-lived particles such as $K_{S}^{0}$ and $\\Lambda$ and allows to greatly enhance the physics potential and capabilities of the LHCb upgrade when compared to its previous implementation.

  14. Optimal sizing of battery storage for stand-alone hybrid (photo-voltaic + diesel) power systems

    Science.gov (United States)

    Shaahid, S. M.; Elhadidy, M. A.

    2005-09-01

    An important element of hybrid photo- voltaic(PV) + diesel sytem is battery storage. Size of battery storage plays a role in optimum operation of the hybrid system. Emphasis needs to be placed on this issue. In this perspective, hourly solar radiation data, for the period 1986 93 recorded at Dhahran, Saudi Arabia, have been analyzed to investigate the optimum size of battery storage capacity for hybrid (PV + diesel) power systems. Various sizing configurations have been simulated. The monthly average daily values of solar global radiation range from 3.61 to 7.96kWh/m2. As a case study, hybrid systems considered in the present analysis consist of 225m2 PV array area (panels/modules) supplemented with battery storage unit and diesel backup generators (to meet the load requirements of a typical residential building with annual electrical energy demand of 35,200kWh). The monthly average energy generated from the aforementioned hybrid system for different scenarios has been presented. More importantly, the study explores the influence of variation of battery storage capacity on hybrid power generation. The results exhibit a trade-off between size of the storage capacity and diesel power to be generated to cope with annual load distribution. Concurrently, the energy to be generated from the diesel generator and the number of operational hours of the diesel system to meet the load demand have been also addressed.The study shows that for optimum operation of diesel system, storage capacity equivalent to 12 18h of maximum monthly average hourly demand need to be used. It has been found that in the absence of battery bank, ˜58% of the load needs to be provided by the diesel system. However, use of 12h of battery storage (autonomy) reduces diesel energy generation by ˜49% and the number of hours of operation of the diesel system get reduced by about ˜82%. The findings of this study can be employed as a tool for sizing of battery storage for PV/diesel systems for other regions having climates similar to the location considered in the study.

  15. Maximun power point tracker of photovoltaic s panels for stand alone systems

    International Nuclear Information System (INIS)

    Stoll, R; Manno, R

    2005-01-01

    The low energetic efficiency of photovoltaic s panels is known, in addition, due to the use of linear regulators, which dissipate an important bit of the generated energy, the efficiency of the photovoltaic systems is still smaller.Also, the I-V characteristic curve of the photovoltaic modules depends on the solar radiation and the own temperature; consequently, the maximum power point (Wp) changes permanently.In conclusion, to produce electricity with photovoltaic panels is very expensive. However due to preserve the environment this technology is widely used.With the purpose of optimizing the amount of energy produced by the photovoltaic system, two complementary methods are used.One is the Maximum Power Point Tracker (MPPT) system and the other one is the Solar Tracker system.The objective of this project is to reduce that cost increasing the amount of energy produced by the solar panels using a Maximum Power Point Tracker system.This device consists of a DC/DC buck converter of high performance, controlled by a PIC 16F873 micro controller; which carries out the conversions of the analogical signals of the solar array to digital signals (ADC), the PIC output digital signals to the PWM control of the power FET (DAC), and calculates the Duty Cycle (D) for the point of I-V curve where this product becomes maximum.Measurements for different loads and battery charges were made.With the obtained results, the comparisons with a conventional system were made, a greater cession of energy to the load is observed.The main conclusion of this work is: Using a MPPT device to making work the PV module during the greater possible time near the maximum power point, the efficiency of the photovoltaic systems can be increased

  16. Review of stand-alone photovoltaic application projects sponsored by US DOE and US AID

    Science.gov (United States)

    Bifano, W. J.

    Experience with dc photovoltaic systems (without backup power) and ranging in output from 23 to 3,500 peak watts, in a wide range of environmental conditions and with a wide range of insolation, is described. Cooperation of NASA with other government agencies resulted in the installation of an air pollution monitor in New Jersey, a seismic sensor in Hawaii, power for lookout towers in national forests in California, an electric power system for a Papago Indian village in Arizona, and a power system for a grain mill and water pump in Tangaye, Upper Volta. Significant operational results are discussed and system reliability is assessed for the 20 experimental systems installed since 1976. Additional systems to be installed overseas are highlighted, and economic factors are considered.

  17. Transforming stand-alone expert system into a community of cooperating agents

    CERN Document Server

    Jennings, N R; Aarnts, R P; Fuchs, J; Skarek, Paul

    1993-01-01

    Distributed Artificial Intelligence (DAI) systems in which multiple problem solving agents cooperate to achieve a common objective is a rapidly emerging and promising technology. However, as yet, there have been relatively few reported cases of such systems being employed to tackle real-world problems in realistic domains. One of the reasons for this is that DAI researchers have given virtually no consideration to the process of incorporating pre-existing systems into a community of cooperating agents. Yet reuse is a primary consideration for any organisation with a large software base. To redress the balance, this paper reports on an experiment undertaken at the CERN laboratories, in which two pre-existing and standalone expert systems for diagnosing faults in a particle accelerator were transformed into a community of cooperating agents. The experiences and insights gained during this process provide a valuable first step towards satisfying the needs of potential users of DAI technology - identifying the ty...

  18. Does sketching stand alone as a communication tool during concept generation in design teams?

    NARCIS (Netherlands)

    Nik Ahmad Ariff, N.S.; Badke-Schaub, P.G.; Eris, O.

    2012-01-01

    The present study investigates the relation between sketching and communication in teams during the idea generation process in early concept generation. A quasi-experiment study has been conducted with Masters students of Industrial Design Engineering at Delft University of Technology, Netherlands.

  19. Design of a computer-aided Four Channel Stand Alone Data Logger ...

    African Journals Online (AJOL)

    UNISWA Research Journal of Agriculture, Science and Technology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 5, No 2 (2001) >. Log in or Register to get access to full text downloads.

  20. Feedforward Control Strategy for the state-decoupling Stand-alone UPS with LC output filter

    DEFF Research Database (Denmark)

    Lu, Jinghang; Savaghebi, Mehdi; Guerrero, Josep M.

    2017-01-01

    In this paper, the disturbance rejection performance of the cascaded control strategy for UPS system is investigated. The comparison of closed loop system performance between conventional cascaded control (CCC) strategy and state-decoupling cascaded control (SDCC) strategy are further explored....... In order to further increase the load current disturbance rejection capability of the state-decoupling in UPS system, a feedforward control strategy is proposed. In addition, the design principle for the current and voltage regulators are discussed. Simulation and experimental results are provided...

  1. Kajian Pemanfaatan Stand Alone Photovoltaic System Untuk Penerangan Jalan Umum Di Pulau Nusa Penida

    Directory of Open Access Journals (Sweden)

    I.W. Yudi Martha Wiguna

    2012-12-01

    Full Text Available   Nusa Penida merupakan sebuah pulau di tenggara pulau Bali dengan jumlah penduduk 47.448 jiwa. Ketersediaan daya pembangkit PLN di pulau Nusa Penida adalah sebesar 3200 kW. Dengan beban puncak sebesar 2530 kW maka cadangan listrik saat ini hanya sebesar 670 kW. Hal itu menyebabkan krisis listrik sangat terasa bagi masyarakat di daerah terpencil seperti di Pulau Nusa Penida. Saat ini salah satu solusi yang memungkinkan adalah mengembangkan sumber energi terbarukan. Di Pulau Nusa Penida sudah dikembangkan PLTS. Bahkan PLTS di Pulau Nusa Penida dikembangkan juga pada sistem penerangan jalan umum. Pada penelitian ini dilakukan analisa teknis dan biaya untuk mengetahui kelayakan Sistem PJU-TS tersebut. Pada analisa teknis dilakukan pengukuran output tegangan dan arus dari PV Panel ke Charger Controller, dari Charger Controller ke baterai dan ke beban. Analisa teknis menghasilkan bahwa penyebab kerusakan baterai karena kapasitas pembangkitan tidak sebanding dengan kebutuhan kapasitas beban PJU-TS. Dengan kapasitas baterai yang terus kecil akan menyebabkan kerusakan pada baterai. Selain itu karena usia baterai yang sudah lama. Analisa biaya dilakukan dengan 3 skenario dengan tingkat IRR yang ingin dicapai sebesar 10, 11, dan 12 %. Dihasilkan harga jual yang pantas untuk energi listrik PJU-TS Nusa Penida berkisar antara Rp.29.194,00 s/d Rp.31.585,00 per kWh.

  2. Applying Rhetorical Genre Studies to a Stand-Alone Online Professional Writing Course

    Science.gov (United States)

    Adams, Heather Brook; Jenkins, Patricia

    2015-01-01

    This program profile explains and illustrates a pedagogical application of Rhetorical Genre Studies (RGS) to a one-semester, upper-division online Professional Writing course. We explain our use of a heuristic, which we liken to "night-vision goggles," that enables students to systematically analyze field data that they gather from a…

  3. Optimal Sizing and Operation of Stand-Alone Hybrid Power Systems

    DEFF Research Database (Denmark)

    Kyriakidis, Ioannis; Chaudhary, Sanjay; Pillai, Jayakrishnan Radhakrishna

    2014-01-01

    The main goal of this study is to contribute to the design of an optimized hybrid renewable power plant for the island of Agios Efstratios. The initial step is to analyze the attributes and applications of various energy generation and storage technologies and focus on the most suitable ones for ...

  4. The Small, Stand-Alone Early College: Impact on High School Outcomes

    Science.gov (United States)

    Glennie, Elizabeth; Unlu, Fatih; Furey, Jane

    2016-01-01

    North Carolina's Early College model is the subject of an IES-funded eleven-year longitudinal experimental study that utilized a lottery process to assign early college applicants to either treatment or control groups. This paper presents findings related to high school outcomes. The primary goal of the early college model is to increase the…

  5. The Small, Stand-Alone Early College: Impact on Postsecondary Outcomes

    Science.gov (United States)

    Unlu, Fatih; Furey, Jane

    2016-01-01

    This paper presents results from the longitudinal experimental study conducted on North Carolina's early college model described in an earlier paper. The primary purpose of this paper is to present the impact of the early college model on outcomes related to postsecondary enrollment. The specific research questions driving this study include: (1)…

  6. Mitigation of large power spills by an energy storage device in a stand alone energy system

    NARCIS (Netherlands)

    D. Bhaumik (Debarati); D.T. Crommelin (Daan); A.P. Zwart (Bert)

    2018-01-01

    textabstractThe unpredictable nature of wind energy makes its integration to the electric grid highly challenging. However, these challenges can be addressed by incorporating storage devices (batteries) in the system. We perform an overall assessment of a single domestic power system with a wind

  7. Modelling of fluid-solid interaction using two stand-alone codes

    CSIR Research Space (South Africa)

    Grobler, Jan H

    2010-01-01

    Full Text Available coastal structures rely on breakwaters to protect them and therefore the study of breakwater structures and armour units (for example dolosse) are of importance in coastal engineering. Traditionally, these studies involved the building of three... single armour unit [5]. A recent study used a model containing a relatively large number of interlocking armour units [6]. This paper describes the development of a method that allows individual armour units to move relative to each other. Such a...

  8. A high-performance stand-alone solar PV power system for LED lighting

    KAUST Repository

    Huang, B. J.

    2010-06-01

    The present study developed a high-performance solar PV power technology for the LED lighting of a solar home system. The nMPPO (near-Maximum-Power- Point- Operation) design is employed in system design to eliminate MPPT. A feedback control system using pulse width modulation (PWM) technique was developed for battery charging control which can increase the charging capacity by 78%. For high-efficiency lighting, the LED is directly driven by battery using a PWM discharge control to eliminate a DC/DC converter. Two solar-powered LED lighting systems (50W and 100W LED) were built. The long-term outdoor tests have shown that the loss of load probability for full-night lighting requirement is zero for 50W LED and 3.6% for 100W LED. © 2010 IEEE.

  9. Single-crate stand-alone CAMAC control system for a negative ion source test facility

    International Nuclear Information System (INIS)

    Juras, R.C.; Ziegler, N.F.

    1979-01-01

    A single-crate CAMAC system was configured to control a negative ion source development facility at ORNL and control software was written for the crate microcomputer. The software uses inputs from a touch panel and a shaft encoder to control the various operating parameters of the test facility and uses the touch panel to display the operating status. Communication to and from the equipment at ion source potential is accomplished over optical fibers from an ORNL-built CAMAC module. A receiver at ion source potential stores the transmitted data and some of these stored values are then used to control discrete parameters of the ion source (i.e., power supply on or off). Other stored values are sent to a multiplexed digital-to-analog converter to provide analog control signals. A transmitter at ion source potential transmits discrete status information and several channels of analog data from an analog-to-digital converter back to the ground-potential receiver where it is stored to be read and displayed by the software

  10. A Voltage and Frequency Control Strategy for Stand-Alone Full Converter Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Andrés Peña Asensio

    2018-02-01

    Full Text Available This paper addresses the design and analysis of a voltage and frequency control (VFC strategy for full converter (FC-based wind energy conversion systems (WECSs and its applicability for the supply of an isolated load. When supplying an isolated load, the role of the back-to-back converters in the FC must change with respect to a grid-connected application. Voltage and frequency are established by the FC line side converter (LSC, while the generator side converter (GSC is responsible for maintaining constant voltage in the DC link. Thus, the roles of the converters in the WECS are inverted. Under such control strategies, the LSC will automatically supply the load power and hence, in order to maintain a stable operation of the WECS, the wind turbine (WT power must also be controlled in a load-following strategy. The proposed VFC is fully modelled and a stability analysis is performed. Then, the operation of the WECS under the proposed VFC is simulated and tested on a real-time test bench, demonstrating the performance of the VFC for the isolated operation of the WECS.

  11. Effects of Teaching Critical Thinking to Saudi Female University Students Using a Stand-Alone Course

    Science.gov (United States)

    Al Ghamdi, Amani K. Hamdan; Deraney, Philline M.

    2013-01-01

    Teaching critical thinking, an educational goal widely discussed in the last 30 years (Halpern, 1993), is an essential element of professional and higher education as it promotes reasoned judgments under "conditions of uncertainty," a hallmark of professionalism (Levine, 2010; Shulman, 2005; Perry, 1970). In this study, the researchers…

  12. Analysis and optimization of hybrid excitation permanent magnet synchronous generator for stand-alone power system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huijun, E-mail: huijun024@gmail.com [School of Instrumentation Science and Opto-electronics Engineering, Beihang University (China); Qu, Zheng; Tang, Shaofei; Pang, Mingqi [School of Instrumentation Science and Opto-electronics Engineering, Beihang University (China); Zhang, Mingju [Shanghai Aerospace Control Technology Institute, Shanghai (China)

    2017-08-15

    Highlights: • One novel permanent magnet generator structure has been proposed to reduce voltage regulation ratio. • Finite element method and equivalent circuit methods are both employed to realize rapid generator design. • Design of experiment (DOE) method is used to optimize permanent magnet shape for reduce voltage waveform distortion. • The obtained analysis and experiment results verify the proposed design methods. - Abstract: In this paper, electromagnetic design and permanent magnet shape optimization for permanent magnet synchronous generator with hybrid excitation are investigated. Based on generator structure and principle, design outline is presented for obtaining high efficiency and low voltage fluctuation. In order to realize rapid design, equivalent magnetic circuits for permanent magnet and iron poles are developed. At the same time, finite element analysis is employed. Furthermore, by means of design of experiment (DOE) method, permanent magnet is optimized to reduce voltage waveform distortion. Finally, the validity of proposed design methods is validated by the analytical and experimental results.

  13. Bifacial PV cell with reflector for stand-alone mast for sensor powering purposes

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Thorsteinsson, Sune; Poulsen, Peter Behrensdorff

    2017-01-01

    Reflectors to bifacial PV-cells are simulated and prototyped in this work. The aim is to optimize the reflector to specific latitudes, and particularly northern latitudes. Specifically, by using minimum semiconductor area the reflector must be able to deliver the electrical power required at the ...... at the condition of minimum solar travel above the horizon, worst weather condition etc. We will test a bifacial PV-module with a retroreflector, and compare the output with simulations combined with local solar data....

  14. environmental/climatic effect on stand-alone solar energy supply

    African Journals Online (AJOL)

    climatic and environmental effects on PV system. A discussion of results obtained from simulations is also ... dant solar energy available throughout the year with reserve estimate of 3.5 - 7.0 kW/m2/day [1]. In order to ... based MPPT method [4], fractional open-circuit. Nigerian Journal of Technology. Vol. 31, No. 1, March ...

  15. Comparing Memory-Efficient Genome Assemblers on Stand-Alone and Cloud Infrastructures

    KAUST Repository

    Kleftogiannis, Dimitrios A.

    2013-09-27

    A fundamental problem in bioinformatics is genome assembly. Next-generation sequencing (NGS) technologies produce large volumes of fragmented genome reads, which require large amounts of memory to assemble the complete genome efficiently. With recent improvements in DNA sequencing technologies, it is expected that the memory footprint required for the assembly process will increase dramatically and will emerge as a limiting factor in processing widely available NGS-generated reads. In this report, we compare current memory-efficient techniques for genome assembly with respect to quality, memory consumption and execution time. Our experiments prove that it is possible to generate draft assemblies of reasonable quality on conventional multi-purpose computers with very limited available memory by choosing suitable assembly methods. Our study reveals the minimum memory requirements for different assembly programs even when data volume exceeds memory capacity by orders of magnitude. By combining existing methodologies, we propose two general assembly strategies that can improve short-read assembly approaches and result in reduction of the memory footprint. Finally, we discuss the possibility of utilizing cloud infrastructures for genome assembly and we comment on some findings regarding suitable computational resources for assembly.

  16. Wind-driven stand-alone DFIG with battery and pumped hydro ...

    Indian Academy of Sciences (India)

    A simple control strategy has been implemented for maintaining the set values of voltage magnitude and frequency at the stator terminals of DFIG, which serve as a virtual grid for connecting ac loads and SCIM. Based on the availability of power in the wind, PHSP and battery, various operating modes of the proposed ...

  17. Assessing Self-Regulation of Learning Dimensions in a Stand-alone MOOC Platform

    Directory of Open Access Journals (Sweden)

    Daniel Friday Owoichoche Onah

    2017-06-01

    Full Text Available A capacity for self-regulated learning (SRL has long been recognised as an important factor in successful studies. Although educational researchers have started to investigate the concept of SRL in the context of online education, very little is yet known about SRL in relation to massive open online courses (MOOCs or of appropriate strategies to foster SRL skills in MOOC learners. Self-regulation is particularly important in a MOOC-based study, which demands effective independent learning, and where widely acknowledged high dropout rates are observed. This study reports an investigation and assessment of the concept of SRL using a novel MOOC platform (eLDa by providing study options (either via a self-directed learning or instructor-led learning using a novel learning tool. In view of this, the research presents general description of self-regulated learning and explored the various existing dimensions used to expose the learners SRL skills. Drawing comparison of the online tool, the results and findings of the data were analysed. The study dis¬cusses how the various dimensions contributed to the knowledge representation of the self-regulated learning abilities shown by the learners. We present how these SRL dimensions captured using the measuring instrument contributes to our growing understanding of the distinctive features of the individual learner’s self-regulated learning. MOOCs success required a high performance of self-regulated learning abilities which at the moment very little has shown these degree of supporting SRL skills. This paper presents preliminary evaluation of a novel e-learning tool known, as ‘eLDa’ developed to implement this investi¬gation of self-regulation of learning. The research applied a modified online self-regulated learning questionnaire (OSLQ as the instrument to measure the SRL skills. The modified questionnaire known as MOOC OSLQ (MOSLQ was developed with a 19-item scale questions that exposes the six SRL dimensions used in this study.

  18. Stand-alone Cosmic Muon Reconstruction Before Installation of the CMS Silicon Strip Tracker

    CERN Document Server

    Adam, W; Dragicevic, M; Friedl, M; Fruhwirth, R; Hansel, S; Hrubec, J; Krammer, M; Oberegger, M; Pernicka, M; Schmid, S; Stark, RS; Steininger, H; Uhl, D; Waltenberger, W; Widl, E; Van Mechelen, P; Cardaci, M; Beaumont, W; de Langhe, E; de Wolf, E A; Delmeire, E; Hashemi, M; Bouhali, O; Charaf, O; Clerbaux, B; Dewulf, J P; Elgammal, S; Hammad, G; de Lentdecker, G; Marage, P; Vander Velde, C; Vanlaer, P; Wickens, J; Adler, V; Devroede, O; De Weirdt, S; D'Hondt, J; Goorens, R; Heyninck, J; Maes, J; Mozer, M; Tavernier, S; Van Lancker, L; Van Mulders, P; Villella, I; Wastiels, C; Bonnet, J L; Bruno, G; De Callatay, B; Florins, B; Giammanco, A; Gregoire, G; Keutgen, Th; Kcira, D; Lemaitre, V; Michotte, D; Militaru, O; Piotrzkowski, K; Quertermont, L; Roberfroid, V; Rouby, X; Teyssier, D; Daubie, E; Anttila, E; Czellar, S; Engstrom, P; Harkonen, J; Karimaki, V; Kostesmaa, J; Kuronen, A; Lampen, T; Linden, T; Luukka, P R; Maenpaa, T; Michal, S; Tuominen, E; Tuominiemi, J; Ageron, M; Baulieu, G; Bonnevaux, A; Boudoul, G; Chabanat, E; Chabert, E; Chierici, R; Contardo, D; Della Negra, R; Dupasquier, T; Gelin, G; Giraud, N; Guillot, G; Estre, N; Haroutunian, R; Lumb, N; Perries, S; Schirra, F; Trocme, B; Vanzetto, S; Agram, J L; Blaes, R; Drouhin, F; Ernenwein, J P; Fontaine, J C; Berst, J D; Brom, J M; Didierjean, F; Goerlach, U; Graehling, P; Gross, L; Hosselet, J; Juillot, P; Lounis, A; Maazouzi, C; Olivetto, C; Strub, R; Van Hove, P; Anagnostou, G; Brauer, R; Esser, H; Feld, L; Karpinski, W; Klein, K; Kukulies, C; Olzem, J; Ostapchuk, A; Pandoulas, D; Pierschel, G; Raupach, F; Schael, S; Schwering, G; Sprenger, D; Thomas, M; Weber, M; Wittmer, B; Wlochal, M; Beissel, F; Bock, E; Flugge, G; Gillissen, C; Hermanns, T; Heydhausen, D; Jahn, D; Kaussen, G; Linn, A; Perchalla, L; Poettgens, M; Pooth, O; Stahl, A; Zoeller, M H; Buhmann, P; Butz, E; Flucke, G; Hamdorf, R; Hauk, J; Klanner, R; Pein, U; Schleper, P; Steinbruck, G; Blum, P; De Boer, W; Dierlamm, A; Dirkes, G; Fahrer, M; Frey, M; Furgeri, A; Hartmann, F; Heier, S; Hoffmann, K H; Kaminski, J; Ledermann, B; Liamsuwan, T; Muller, S; Muller, Th; Schilling, F P; Simonis, H J; Steck, P; Zhukov, V; Cariola, P; De Robertis, G; Ferorelli, R; Fiore, L; Preda, M; Sala, G; Silvestris, L; Tempesta, P; Zito, G; Creanza, D; De Filippis, N; De Palma, M; Giordano, D; Maggi, G; Manna, N; My, S; Selvaggi, G; Albergo, S; Chiorboli, M; Costa, S; Galanti, M; Giudice, N; Guardone, N; Noto, F; Potenza, R; Saizu, M A; Sparti, V; Sutera, C; Tricomi, A; Tuve, C; Brianzi, M; Civinini, C; Maletta, F; Manolescu, F; Meschini, M; Paoletti, S; Sguazzoni, G; Broccolo, B; Ciulli, V; D'Alessandro, R; Focardi, E; Frosali, S; Genta, C; Landi, G; Lenzi, P; Macchiolo, A; Magini, N; Parrini, G; Scarlini, E; Cerati, G; Azzi, P; Bacchetta, N; Candelori, A; Dorigo, T; Kaminsky, A; Karaevski, S; Khomenkov, V; Reznikov, S; Tessaro, M; Bisello, D; De Mattia, M; Giubilato, P; Loreti, M; Mattiazzo, S; Nigro, M; Paccagnella, A; Pantano, D; Pozzobon, N; Tosi, M; Bilei, G M; Checcucci, B; Fano, L; Servoli, L; Ambroglini, F; Babucci, E; Benedetti, D; Biasini, M; Caponeri, B; Covarelli, R; Giorgi, M; Lariccia, P; Mantovani, G; Marcantonini, M; Postolache, V; Santocchia, A; Spiga, D; Bagliesi, G; Balestri, G; Berretta, L; Bianucci, S; Boccali, T; Bosi, F; Bracci, F; Castaldi, R; Ceccanti, M; Cecchi, R; Cerri, C; Cucoanes, A S; Dell'Orso, R; Dobur, D; Dutta, S; Giassi, A; Giusti, S; Kartashov, D; Kraan, A; Lomtadze, T; Lungu, G A; Magazzu, G; Mammini, P; Mariani, F; Martinelli, G; Moggi, A; Palla, F; Palmonari, F; Petragnani, G; Profeti, A; Raffaelli, F; Rizzi, D; Sanguinetti, G; Sarkar, S; Sentenac, D; Serban, A T; Slav, A; Soldani, A; Spagnolo, P; Tenchini, R; Tolaini, S; Venturi, A; Verdini, P G; Vos, M; Zaccarelli, L; Avanzini, C; Basti, A; Benucci, L; Bocci, A; Cazzola, U; Fiori, F; Linari, S; Massa, M; Messineo, A; Segneri, G; Tonelli, G; Azzurri, P; Bernardini, J; Borrello, L; Calzolari, F; Foa, L; Gennai, S; Ligabue, F; Petrucciani, G; Rizzi, A; Yang, Z; Benotto, F; Demaria, N; Dumitrache, F; Farano, R; Borgia, M A; Castello, R; Costa, M; Migliore, E; Romero, A; Abbaneo, D; Abbas, M; Ahmed, I; Akhtar, I; Albert, E; Bloch, C; Breuker, H; Butt, S; Buchmuller, O; Cattai, A; Delaere, C; Delattre, M; Edera, L M; Engstrom, P; Eppard, M; Gateau, M; Gill, K; Giolo-Nicollerat, A S; Grabit, R; Honma, A; Huhtinen, M; Kloukinas, K; Kortesmaa, J; Kottelat, L J; Kuronen, A; Leonardo, N; Ljuslin, C; Mannelli, M; Masetti, L; Marchioro, A; Mersi, S; Michal, S; Mirabito, L; Muffat-Joly, J; Onnela, A; Paillard, C; Pal, I; Pernot, J F; Petagna, P; Petit, P; Piccut, C; Pioppi, M; Postema, H; Ranieri, R; Ricci, D; Rolandi, G; Ronga, F; Sigaud, C; Syed, A; Siegrist, P; Tropea, P; Troska, J; Tsirou, A; Vander Donckt, M; Vasey, F; Alagoz, E; Amsler, C; Chiochia, V; Regenfus, Christian; Robmann, P; Rochet, J; Rommerskirchen, T; Schmidt, A; Steiner, S; Wilke, L; Church, I; Cole, J; Coughlan, J; Gay, A; Taghavi, S; Tomalin, I; Bainbridge, R; Cripps, N; Fulcher, J; Hall, G; Noy, M; Pesaresi, M; Radicci, V; Raymond, D M; Sharp, P; Stoye, M; Wingham, M; Zorba, O; Goitom, I; Hobson, P R; Reid, I; Teodorescu, L; Hanson, G; Jeng, G Y; Liu, H; Pasztor, G; Satpathy, A; Stringer, R; Mangano, B; Affolder, K; Affolder, T; Allen, A; Barge, D; Burke, S; Callahan, D; Campagnari, C; Crook, A; D'Alfonso, M; Dietch, J; Garberson, Jeffrey Ford; Hale, D; Incandela, H; Incandela, J; Jaditz, S; Kalavase, P; Kreyer, S; Kyre, S; Lamb, J; Mc Guinness, C; Mills, C; Nguyen, H; Nikolic, M; Lowette, S; Rebassoo, F; Ribnik, J; Richman, J; Rubinstein, N; Sanhueza, S; Shah, Y; Simms, L; Staszak, D; Stoner, J; Stuart, D; Swain, S; Vlimant, J R; White, D; Ulmer, K A; Wagner, S R; Bagby, L; Bhat, P C; Burkett, K; Cihangir, S; Gutsche, O; Jensen, H; Johnson, M; Luzhetskiy, N; Mason, D; Miao, T; Moccia, S; Noeding, C; Ronzhin, A; Skup, E; Spalding, W J; Spiegel, L; Tkaczyk, S; Yumiceva, F; Zatserklyaniy, A; Zerev, E; Anghel, I; Bazterra, V E; Gerber, C E; Khalatian, S; Shabalina, E; Baringer, P; Bean, A; Chen, J; Hinchey, C; Martin, C; Moulik, T; Robinson, R; Gritsan, A V; Lae, C K; Tran, N V; Everaerts, P; Hahn, K A; Harris, P; Nahn, S; Rudolph, M; Sung, K; Betchart, B; Demina, R; Gotra, Y; Korjenevski, S; Miner, D; Orbaker, D; Christofek, L; Hooper, R; Landsberg, G; Nguyen, D; Narain, M; Speer, T; Tsang, K V

    2009-01-01

    The subsystems of the CMS silicon strip tracker were integrated and commissioned at the Tracker Integration Facility (TIF) in the period from November 2006 to July 2007. As part of the commissioning, large samples of cosmic ray data were recorded under various running conditions in the absence of a magnetic field. Cosmic rays detected by scintillation counters were used to trigger the readout of up to 15% of the final silicon strip detector, and over 4.7 million events were recorded. This document describes the cosmic track reconstruction and presents results on the performance of track and hit reconstruction as from dedicated analyses.

  19. Alignment of the CMS Silicon Strip Tracker during stand-alone Commissioning

    CERN Document Server

    Adam, W; Dragicevic, M; Friedl, M; Frühwirth, R; Hansel, S; Hrubec, J; Krammer, M; Oberegger, M; Pernicka, M; Schmid, S; Stark, R; Steininger, H; Uhl, D; Waltenberger, W; Widl, E; Van Mechelen, P; Cardaci, M; Beaumont, W; de Langhe, E; de Wolf, E A; Delmeire, E; Hashemi, M; Bouhali, O; Charaf, O; Clerbaux, B; Dewulf, J P; Elgammal, S; Hammad, G; de Lentdecker, G; Marage, P; Vander Velde, C; Vanlaer, P; Wickens, J; Adler, V; Devroede, O; De Weirdt, S; D'Hondt, J; Goorens, R; Heyninck, J; Maes, J; Mozer, Matthias Ulrich; Tavernier, S; Van Lancker, L; Van Mulders, P; Villella, I; Wastiels, C; Bonnet, J L; Bruno, G; De Callatay, B; Florins, B; Giammanco, A; Gregoire, G; Keutgen, Th; Kcira, D; Lemaitre, V; Michotte, D; Militaru, O; Piotrzkowski, K; Quertermont, L; Roberfroid, V; Rouby, X; Teyssier, D; daubie, E; Anttila, E; Czellar, S; Engström, P; Härkönen, J; Karimäki, V; Kostesmaa, J; Kuronen, A; Lampén, T; Lindén, T; Luukka, P R; Mäenää, T; Michal, S; Tuominen, E; Tuominiemi, J; Ageron, M; Baulieu, G; Bonnevaux, A; Boudoul, G; Chabanat, E; Chabert, E; Chierici, R; Contardo, D; Della Negra, R; Dupasquier, T; Gelin, G; Giraud, N; Guillot, G; Estre, N; Haroutunian, R; Lumb, N; Perries, S; Schirra, F; Trocme, B; Vanzetto, S; Agram, J L; Blaes, R; Drouhin, F; Ernenwein, J P; Fontaine, J C; Berst, J D; Brom, J M; Didierjean, F; Goerlach, U; Graehling, P; Gross, L; Hosselet, J; Juillot, P; Lounis, A; Maazouzi, C; Olivetto, C; Strub, R; Van Hove, P; Anagnostou, G; Brauer, R; Esser, H; Feld, L; Karpinski, W; Klein, K; Kukulies, C; Olzem, J; Ostapchuk, A; Pandoulas, D; Pierschel, G; Raupach, F; Schael, S; Schwering, G; Sprenger, D; Thomas, M; Weber, M; Wittmer, B; Wlochal, M; Beissel, F; Bock, E; Flugge, G; Gillissen, C; Hermanns, T; Heydhausen, D; Jahn, D; Kaussen, G; Linn, A; Perchalla, L; Poettgens, M; Pooth, O; Stahl, A; Zoeller, M H; Buhmann, P; Butz, E; Flucke, G; Hamdorf, R; Hauk, J; Klanner, R; Pein, U; Schleper, P; Steinbrück, G; Blüm, P; De Boer, W; Dierlamm, A; Dirkes, G; Fahrer, M; Frey, M; Furgeri, A; Hartmann, F; Heier, S; Hoffmann, K H; Kaminski, J; Ledermann, B; Liamsuwan, T; Müller, S; Müller, Th; Schilling, F P; Simonis, H J; Steck, P; Zhukov, V; Cariola, P; De Robertis, G; Ferorelli, R; Fiore, L; Preda, M; Sala, G; Silvestris, L; Tempesta, P; Zito, G; Creanza, D; De Filippis, N; De Palma, M; Giordano, D; Maggi, G; Manna, N; My, S; Selvaggi, G; Albergo, S; Chiorboli, M; Costa, S; Galanti, M; Giudice, N; Guardone, N; Noto, F; Potenza, R; Saizu, M A; Sparti, V; Sutera, C; Tricomi, A; Tuve, C; Brianzi, M; Civinini, C; Maletta, F; Manolescu, F; Meschini, M; Paoletti, S; Sguazzoni, G; Broccolo, B; Ciulli, V; D'Alessandro, R; Focardi, E; Frosali, S; Genta, C; Landi, G; Lenzi, P; Macchiolo, A; Magini, N; Parrini, G; Scarlini, E; Cerati, G; Azzi, P; Bacchetta, N; Candelori, A; Dorigo, T; Kaminsky, A; Karaevski, S; Khomenkov, V; Reznikov, S; Tessaro, M; Bisello, D; De Mattia, M; Giubilato, P; Loreti, M; Mattiazzo, S; Nigro, M; Paccagnella, A; Pantano, D; Pozzobon, N; Tosi, M; Bilei, G M; Checcucci, B; Fanò, L; Servoli, L; Ambroglini, F; Babucci, E; Benedetti, D; Biasini, M; Caponeri, B; Covarelli, R; Giorgi, M; Lariccia, P; Mantovani, G; Marcantonini, M; Postolache, V; Santocchia, A; Spiga, D; Bagliesi, G; Balestri, G; Berretta, L; Bianucci, S; Boccali, T; Bosi, F; Bracci, F; Castaldi, R; Ceccanti, M; Cecchi, R; Cerri, C; Cucoanes, A S; Dell'Orso, R; Dobur, D; Dutta, S; Giassi, A; Giusti, S; Kartashov, D; Kraan, A; Lomtadze, T; Lungu, G A; Magazzu, G; Mammini, P; Mariani, F; Martinelli, G; Moggi, A; Palla, F; Palmonari, F; Petragnani, G; Profeti, A; Raffaelli, F; Rizzi, D; Sanguinetti, G; Sarkar, S; Sentenac, D; Serban, A T; Slav, A; Soldani, A; Spagnolo, P; Tenchini, R; Tolaini, S; Venturi, A; Verdini, P G; Vos, M; Zaccarelli, L; Avanzini, C; Basti, A; Benucci, L; Bocci, A; Cazzola, U; Fiori, F; Linari, S; Massa, M; Messineo, A; Segneri, G; Tonelli, G; Azzurri, P; Bernardini, J; Borrello, L; Calzolari, F; Foà, L; Gennai, S; Ligabue, F; Petrucciani, G; Rizzi, A; Yang, Z; Benotto, F; Demaria, N; Dumitrache, F; Farano, R; Borgia, M A; Castello, R; Costa, M; Migliore, E; Romero, A; Abbaneo, D; Abbas, M; Ahmed, I; Akhtar, I; Albert, E; Bloch, C; Breuker, H; Butt, S; Buchmuller, O; Cattai, A; Delaere, C; Delattre, M; Edera, L M; Engstrom, P; Eppard, M; Gateau, M; Gill, K; Giolo-Nicollerat, A S; Grabit, R; Honma, A; Huhtinen, M; Kloukinas, K; Kortesmaa, J; Kottelat, L J; Kuronen, A; Leonardo, N; Ljuslin, C; Mannelli, M; Masetti, L; Marchioro, A; Mersi, S; Michal, S; Mirabito, L; Muffat-Joly, J; Onnela, A; Paillard, C; Pal, I; Pernot, J F; Petagna, P; Petit, P; Piccut, C; Pioppi, M; Postema, H; Ranieri, R; Ricci, D; Rolandi, G; Ronga, F; Sigaud, C; Syed, A; Siegrist, P; Tropea, P; Troska, J; Tsirou, A; Vander Donckt, M; Vasey, F; Alagoz, E; Amsler, Claude; Chiochia, V; Regenfus, Christian; Robmann, P; Rochet, J; Rommerskirchen, T; Schmidt, A; Steiner, S; Wilke, L; Church, I; Cole, J; Coughlan, J; Gay, A; Taghavi, S; Tomalin, I; Bainbridge, R; Cripps, N; Fulcher, J; Hall, G; Noy, M; Pesaresi, M; Radicci, V; Raymond, D M; Sharp, P; Stoye, M; Wingham, M; Zorba, O; Goitom, I; Hobson, P R; Reid, I; Teodorescu, L; Hanson, G; Jeng, G Y; Liu, H; Pasztor, G; Satpathy, A; Stringer, R; Mangano, B; Affolder, K; Affolder, T; Allen, A; Barge, D; Burke, S; Callahan, D; Campagnari, C; Crook, A; D'Alfonso, M; Dietch, J; Garberson, Jeffrey Ford; Hale, D; Incandela, H; Incandela, J; Jaditz, S; Kalavase, P; Kreyer, S; Kyre, S; Lamb, J; Mc Guinnessr, C; Mills, C; Nguyen, H; Nikolic, M; Lowette, S; Rebassoo, F; Ribnik, J; Richman, J; Rubinstein, N; Sanhueza, S; Shah, Y; Simms, L; Staszak, D; Stoner, J; Stuart, D; Swain, S; Vlimant, J R; White, D; Ulmer, K A; Wagner, S R; Bagby, L; Bhat, P C; Burkett, K; Cihangir, S; Gutsche, O; Jensen, H; Johnson, M; Luzhetskiy, N; Mason, D; Miao, T; Moccia, S; Noeding, C; Ronzhin, A; Skup, E; Spalding, W J; Spiegel, L; Tkaczyk, S; Yumiceva, F; Zatserklyaniy, A; Zerev, E; Anghel, I; Bazterra, V E; Gerber, C E; Khalatian, S; Shabalina, E; Baringer, P; Bean, A; Chen, J; Hinchey, C; Martin, C; Moulik, T; Robinson, R; Gritsan, A V; Lae, C K; Tran, N V; Everaerts, P; Hahn, K A; Harris, P; Nahn, S; Rudolph, M; Sung, K; Betchart, B; Demina, R; Gotra, Y; Korjenevski, S; Miner, D; Orbaker, D; Christofek, L; Hooper, R; Landsberg, G; Nguyen, D; Narain, M; Speer, T; Tsang, K V

    2009-01-01

    The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracker. This allowed us to perform first alignment of the active silicon modules with the cosmic tracks using three different statistical approaches; validate the survey and laser alignment system performance; and test the stability of Tracker structures under various stresses and temperatures ranging from +15C to -15C. Comparison with simulation shows that the achieved alignment precision in the barrel part of the tracker leads to residual distributions similar to those obtained with a random misalignment of 50 (80) microns in the outer (inner) part of the barrel.

  20. Daily operation optimisation of hybrid stand-alone system by model predictive control considering ageing model

    International Nuclear Information System (INIS)

    Dufo-López, Rodolfo; Fernández-Jiménez, L. Alfredo; Ramírez-Rosado, Ignacio J.; Artal-Sevil, J. Sergio; Domínguez-Navarro, José A.; Bernal-Agustín, José L.

    2017-01-01

    Highlights: • Method for optimising the daily operation of photovoltaic-wind-diesel-battery systems. • Weather forecasts of hourly wind speed, irradiation, temperature and load are used. • Each day five control variables are optimised for the control of the system. • Operating cost includes real ageing of the batteries and the diesel generator. • Results show that the optimal control strategy used for each day led to cost savings. - Abstract: This article presents a method for optimising the daily operation (minimising the total operating cost) of a hybrid photovoltaic-wind-diesel-battery system using model predictive control. The model uses actual weather forecasts of hourly values of wind speed, irradiation, temperature and load. Five control variables are optimised, and thus their optimal set points values determine the optimal control strategy for each day. This involves the use of an accurate model for estimating the degradation of the batteries by considering the capacity loss due to corrosion and degradation. The model considers the extra costs of maintaining and replacing the diesel generator due to running out of its optimal conditions. The optimisation is carried out by means of genetic algorithms. An example of application compares the total operating cost obtained using the optimal control strategy for each day with the cost of using the optimal control strategy found for the whole year, obtaining savings of up to 7.8%. Also the comparison with the cost of using the “load following” control strategy is analysed, obtaining savings of up to 37.7%.

  1. Constrained control framework for a stand-alone hybrid (Stirling engine)/supercapacitor power generation system

    International Nuclear Information System (INIS)

    Alamir, M.; Rahmani, M.A.; Gualino, D.

    2014-01-01

    Highlights: • A complete state feedback controller for the voltage conditioning stage of a hybrid power plant is proposed. • The controller explicitly handles the state and controller constraints. • The developed control methodology can be applied to various power electronics architectures. - Abstract: In this paper, a complete control architecture is proposed for the voltage conditioning stage of a hybrid power generation system composed of a Stirling engine coupled with a supercapacitor. Such a solar energy-based generation system aims at providing electricity to off-grid regions. The novelty of the proposed architecture is that it completely handles constraints on all the state variables of the electric stage while providing near to optimal performances in terms of settling time. The derivation of the control law enables a deep understanding of the main issues involved in the success of the closed-loop control. Moreover, the resulting feedback laws are real-time compatible and are given in a complete explicit form

  2. X-ray microbeam stand-alone facility for cultured cells irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bożek, Sebastian, E-mail: sebastian.bozek@yahoo.com [Jagiellonian University Medical College, Department of Pharmaceutical Biophysics, Krakow (Poland); Bielecki, Jakub; Wiecheć, Anna; Lekki, Janusz; Stachura, Zbigniew; Pogoda, Katarzyna; Lipiec, Ewelina; Tkocz, Konrad; Kwiatek, Wojciech M. [Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow (Poland)

    2017-03-01

    Highlights: • An X-ray microbeam line for irradiation of living cultured cells was constructed. • A step by step explanation of working principles with engineering details, procedures and calculations is presented. • A model of beam and cell interaction is presented. • A method of uniform irradiation of living cells with an exact dose per a cell is presented. • Results of preliminary experiments are presented. - Abstract: The article describes an X-ray microbeam standalone facility dedicated for irradiation of living cultured cells. The article can serve as an advice for such facilities construction, as it begins from engineering details, through mathematical modeling and experimental procedures, ending up with preliminary experimental results and conclusions. The presented system consists of an open type X-ray tube with microfocusing down to about 2 μm, an X-ray focusing system with optical elements arranged in the nested Kirckpatrick-Baez (or Montel) geometry, a sample stand and an optical microscope with a scientific digital CCD camera. For the beam visualisation an X-ray sensitive CCD camera and a spectral detector are used, as well as a scintillator screen combined with the microscope. A method of precise one by one irradiation of previously chosen cells is presented, as well as a fast method of uniform irradiation of a chosen sample area. Mathematical models of beam and cell with calculations of kerma and dose are presented. The experiments on dose-effect relationship, kinetics of DNA double strand breaks repair, as well as micronuclei observation were performed on PC-3 (Prostate Cancer) cultured cells. The cells were seeded and irradiated on Mylar foil, which covered a hole drilled in the Petri dish. DNA lesions were visualised with γ-H2AX marker combined with Alexa Fluor 488 fluorescent dye.

  3. Experimental stand-alone self-excited induction generator driven by a diesel motor

    Directory of Open Access Journals (Sweden)

    Mhamdi Taoufik

    2017-12-01

    Full Text Available This paper presents an experimental work to design and size a diesel generator (DG. The basic system is equipped with a 1.5 kW self-excited induction generator (SEIG, a diesel motor (DM, a static voltage compensator (SVC and controllers. A proportional integral controller is used to meet the requirement of the SEIG frequency regulation. A controlled voltage source is performed by using an SVC with a fuzzy controller, which adjusts voltage by varying the amount of the injected reactive power. An experimental set-up is used to identify the SEIG parameters and select the convenient bank of capacitors that minimize the SEIG starting up time and fix the convenient margin of voltage. The system has been tested by simulation using models implemented by Matlab/Simulink software. The simulation results confirm the efficiency of the proposed strategy of voltage regulation. Keywords: Diesel motor, SEIG, SVC, Voltage regulation, Frequency regulation

  4. Wind-driven stand-alone DFIG with battery and pumped hydro ...

    Indian Academy of Sciences (India)

    Renewable energy electric conversion system; induction generators; wind power generation; energy storage; power converters. ... converter, (ii) wide speed operation of wind-driven DFIG, (iii) reduced battery capacity, (iv) high energy storage using PHSP and (v) availability of continuous power to the isolated loads.

  5. An Approach for High-precision Stand-alone Positioning in a Dynamic Environment

    Science.gov (United States)

    Halis Saka, M.; Metin Alkan, Reha; Ozpercin, Alişir

    2015-04-01

    In this study, an algorithm is developed for precise positioning in dynamic environment utilizing a single geodetic GNSS receiver using carrier phase data. In this method, users should start the measurement on a known point near the project area for a couple of seconds making use of a single dual-frequency geodetic-grade receiver. The technique employs iono-free carrier phase observations with precise products. The equation of the algorithm is given below; Sm(t(i+1))=SC(ti)+[ΦIF (t(i+1) )-ΦIF (ti)] where, Sm(t(i+1)) is the phase-range between satellites and the receiver, SC(ti) is the initial range computed from the initial known point coordinates and the satellite coordinates and ΦIF is the ionosphere-free phase measurement (in meters). Tropospheric path delays are modelled using the standard tropospheric model. To accomplish the process, an in-house program was coded and some functions were adopted from Easy-Suite available at http://kom.aau.dk/~borre/easy. In order to assess the performance of the introduced algorithm in a dynamic environment, a dataset from a kinematic test measurement was used. The data were collected from a kinematic test measurement in Istanbul, Turkey. In the test measurement, a geodetic dual-frequency GNSS receiver, Ashtech Z-Xtreme, was set up on a known point on the shore and a couple of epochs were recorded for initialization. The receiver was then moved to a vessel and data were collected for approximately 2.5 hours and the measurement was finalized on a known point on the shore. While the kinematic measurement on the vessel were carried out, another GNSS receiver was set up on a geodetic point with known coordinates on the shore and data were collected in static mode to calculate the reference trajectory of the vessel using differential technique. The coordinates of the vessel were calculated for each measurement epoch with the introduced method. With the purpose of obtaining more robust results, all coordinates were calculated once again by inversely, i.e. from the last epoch to the first one. In this way, the estimated coordinates were also controlled. The average of both computed coordinates were used as vessel coordinates and then compared with the known-coordinates those of geodetic receiver epoch by epoch. The results indicate that the calculated coordinates from the introduced method are consistent with the reference trajectory with an accuracy of about 1 decimeter. In contrast, the findings imply lower accuracy for height components with an accuracy of about 2 decimeters. This accuracy level meets the requirement of many applications including some marine applications, precise hydrographic surveying, dredging, attitude control of ships, buoys and floating platforms, marine geodesy, navigation and oceanography.

  6. Problem drinking among at-risk college students: The examination of Greek involvement, freshman status, and history of mental health problems.

    Science.gov (United States)

    Martinez, Haley S; Klanecky, Alicia K; McChargue, Dennis E

    2018-02-06

    Scarce research has examined the combined effect of mental health difficulties and demographic risk factors such as freshman status and Greek affiliation in understanding college problem drinking. The current study is interested in looking at the interaction among freshman status, Greek affiliation, and mental health difficulties. Undergraduate students (N = 413) from a private and public Midwestern university completed a large online survey battery between January 2009 and April 2013. Data from both schools were aggregated for the analyses. After accounting for gender, age, and school type, the three-way interaction indicated that the highest drinking levels were reported in freshman students who reported a history of mental health problems although were not involved in Greek life. Findings are discussed in the context of perceived social norms, as well as alcohol-related screenings and intervention opportunities on college campuses.

  7. Library Instruction for Freshman English: A Multi-Year Assessment of Student Learning

    Directory of Open Access Journals (Sweden)

    Susan Gardner Archambault

    2011-01-01

    Full Text Available Objective – The objective of this study was twofold: 1 to assess the effectiveness of curriculum changes made from the 2009 freshman English library instruction curriculum to the 2010 curriculum at Loyola Marymount University (LMU; and 2 to evaluate the effectiveness of library instruction delivered via a “blended” combination of face-to-face and online instruction versus online instruction alone.Methods – An experimental design compared random samples of student scores from 2009 and 2010 worksheets to determine the effects of a new curriculum on student learning. A second experiment examined the effect of delivery method on student learning by comparing scores from a group of students receiving only online instruction against a group receiving blended instruction.Results – The first component of the study, which compared scores between 2009 and 2010 to examine the effects of the curriculum revisions, had mixed results. Students scored a significantly higher mean in 2010 on completing and correctly listing book citation components than in 2009, but a significantly lower mean on constructing a research question. There was a significant difference in the distribution of scores for understanding differences between information found on the Internet versus through the Library that was better in 2010 than 2009, but worse for narrowing a broad research topic. For the study that examined computer aided instruction, the group of students receiving only computer-assisted instruction did significantly better overall than the group receiving blended instruction. When separate tests were run for each skill, two particular skills, generating keywords and completing book citation and location elements, resulted in a significantly higher mean.Conclusions – The comparison of scores between 2009 and 2010 were mixed, but the evaluation process helped us identify continued problems in the teaching materials to address in the next cycle of revisions

  8. The Attitudes of Freshman Students in Erciyes UniversityFaculty of Medicine towards Absenteeism

    Directory of Open Access Journals (Sweden)

    Zeynep BAYKAN

    2016-10-01

    Full Text Available The aim of this study was to determine the opinions and attitudes of the freshman students in Erciyes University Faculty of Medicine towards absenteeism. It was a descriptive and cross sectional study, which was conducted in May 2015. 81% of 310 students were accessed. A questionnaire including an absenteeism attitude scale was applied to the students. For the analysis of data, Chi square and Mann Whitney U tests were used. 7.2% of students said that they always attended the theoretical lessons whereas 71.1% of them reported that they sometimes did not attend these lessons. 21.7%, on the other hand, stated that they mostly did not attend these lessons. 81.1% of the students indicated that they always attended the practical lessons. Another finding was that foreign students attended the theoretical lessons more than Turkish students. The most common suggestion made by the students for preventing absenteeism was linking the basic courses with clinical information to be used later. The mean score obtained from the absenteeism attitude scale was 54.6 ± 15.0. The mean scores obtained from necessity, responsibility and obligation subscales were 19.6 ± 5.5, 21.4 ± 6.7, and 13.6 ± 6.1, respectively. 73.5% of the students indicated that attendance should not be controlled in the Faculty of Medicine. At the end of the study it was revealed that medical students had negative attitudes towards attendance and there was a need to organize activities that would increase their motivation and prevent absenteeism.

  9. Freshman Students‟ Attitudes and Behavior towards Advanced Grammar and Composition Teaching

    Directory of Open Access Journals (Sweden)

    Romel M. Aceron

    2015-11-01

    Full Text Available Teaching English advanced grammar and composition to college students is important as it provides them with high level of understanding and competence in the language. It guides them in putting words together into sentences and makes them orally produce sounds clearly and effectively. This paper aims to determine the attitudes and behavior towards advanced grammar and composition teaching among freshman college students of Batangas State University. Descriptive method of research has been used to analyze and interpret data. The following instruments such as self-made questionnaire, focus group discussion, data analysis, interview guide, have been utilized to gather data. To analyze and interpret data, mean scores have been used. Pearson’s (r Product Moment Correlation Method has been utilized to treat the null hypothesis with regard to the attitudes and behavior of the students towards advanced grammar and composition teaching. Based on the findings of the study, the students sometimes understand and feel the subject matters, i.e., morphology, phonology, grammar and usage, and mechanics and composition writing. They are also sometimes ready in particular lesson and activity which are given to them in class. The study also reveals that there is no significant relationship between the students’ attitudes and behavior towards AGCT. In this regard, college students taking advanced grammar and composition course must be well-motivated to understand, and must have the readiness to perform the activities entail in the subject areas of morphology, phonology, grammar and usage, and mechanics and composition writing through teacher’s varied approaches, strategies, researches, and integration.

  10. Relation between eating habits and a high body mass index among freshman students: a cross-sectional study.

    Science.gov (United States)

    Gunes, Fatma Esra; Bekiroglu, Nural; Imeryuz, Nese; Agirbasli, Mehmet

    2012-06-01

    This study aimed to examine the relation between eating habits and a high body mass index (BMI) in first-year freshman university students and included 2525 freshman university students 18 to 22 years old from a Turkish population. İn this study, 48% of the students were men. They were asked to complete a questionnaire on their dietary habits including the frequency of their consumption of individual food items, demographic data, and smoking habit. The effects of eating habits on increased BMI (≥25) were analyzed. Of 2259 subjects included in the analyses, 322 were overweight or obese and 1937 had normal and thin BMI (ender, recent weight change, and high number of meals as independent predictors of obesity/overweight. Frequent consumptions of beer, alcoholic drinks other than beer and wine (e.g., spirits including whisky, gin, raki, vodka), coffee, tea, coke, red meat, variety meat, and eggs were associated with a significantly higher risk of obesity/overweight, whereas frequent consumption of snacks was associated with a low risk. Findings of further studies, possibly taking into consideration the absolute quantities of consumption along with cultural and local issues, would guide the adoption of healthier feeding behaviors in this particular age group.

  11. Academy Training Catalog -

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    Department of Transportation — IRIS is a suite of front-end web applications utilizing a centralized back-end Oracle database. The system fully supports the FAA Academy's Distance Learning Program...

  12. Iraqi Military Academies

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    Nodar Z. Mossaki

    2015-03-01

    Full Text Available The article analyzes the system of training of officers in military academies in Iraq – in Zakho, Qalacholan, ar-Rustamiyah and an-Nasiriyah. The author describes the history of creation, process of evolution, challenges and features of training in these colleges. Particular attention paid to military academies in the territory of Iraqi Kurdistan, which actually do not obey the central government of Iraq, however, have the highest level of training. Currently, Iraq's military academies operate on the basis of the NATO standards. Iraqi military academies paid miuch attention to the specifics of the military and political situation in Iraq – counterinsurgency and counterterrorism operations, patrolling cities, fighting in an urban environment etc. Significant place in the curriculum take the courses contributing to the formation of pro-Western sentiment.

  13. A freshman orientation program to provide an overview of the medical learning roadmap.

    Science.gov (United States)

    Fujikura, Terumichi; Nemoto, Takehiro; Takayanagi, Kazue; Kashimura, Masami; Hayasaka, Yoshiaki; Shimizu, Kazuo

    2014-01-01

    International accreditation of medical education was introduced in Japan in 2013 and is planning to be applied in late 2014 or 2015. Students will need to cope with the resulting changes and to recognize by what route they will learn medicine. Therefore, a freshman orientation course, which was based on problem-based learning (PBL) and had been held for first-year students, was modified as an awareness reform program in which students would learn "how to learn medicine." We investigated whether this program has led to useful changes in students' recognition of the way of learning in medical school and their directions as learners. The program was held for 114 first-year medical school students in 2013 and consisted of PBL tutorials, large-classroom lectures, simulation learning using role-play with simulated patients, and team-based learning (TBL), presented in this order. Learning modules that is made with an integration of the clinical sciences with the basic biomedical and the behavioral and social sciences were provided. A nonanonymous questionnaire survey asking" what learning methods are effective for you?" was conducted before and after completion of the course. Furthermore, group answers obtained in TBL were investigated. The score for the question" To what extent can you imagine your route of learning during your 6 years?" significantly increased from 3.1±0.99 (mean±SD) before the course to 3.5±0.88 (plearning, such as PBL, useful for you?" significantly increased from 3.9±0.73 to 4.2±0.71 (plearning interview skills. We believe students should acquire active learning attitudes as adults early in their 6 years of medical school. The level of understanding of" how to learn as adults" was 3.7 and indicated a moderate result. This course employed many educational strategies, and we believe it helped students understand what they learn and how to learn during their 6 years of medical and to get an overview of the learning roadmap.

  14. Socioeconomic Status and the Relationship between the SAT® and Freshman GPA: An Analysis of Data from 41 Colleges and Universities. Research Report No. 2009-1

    Science.gov (United States)

    Sackett, Paul R.; Kuncel, Nathan R.; Arneson, Justin J.; Cooper, Sara R.; Waters, Shonna D.

    2009-01-01

    Critics of educational admissions tests assert that tests measure nothing other than socioeconomic status (SES), and that their apparent validity in predicting academic performance is an artifact of SES. We examine relationships among SAT, SES, and freshman grades in 41 colleges and universities and show that (a) SES is related to SAT scores (r =…

  15. A Study to Measure the Standard Collegiate Level Freshman Writing Course Requirements at Olivet Nazarene University against Those of Other Christian College Coalition Members.

    Science.gov (United States)

    Whitis, Judith A.

    To determine whether Olivet Nazarene University's standard freshman writing course requirements measure favorably with those of the majority of the 75 Christian College Coalition (CCC) members, a study compared the textbooks, papers, activities, and evaluation procedures required by each institution. Stephen Witte's "National Survey of…

  16. Evaluation of the Effectiveness of the Integration of a LITEE Case Study for a Freshman Level Mechanical Engineering Course at The University of Toledo

    Science.gov (United States)

    Franchetti, Matthew

    2011-01-01

    The purpose of this paper is to report the findings of the integration of a manufacturing case study to a freshman level mechanical engineering course at The University of Toledo. The approach to integrate this case study into the class was completed via weekly assignments analyzing the case, small group discussion, and weekly group discussion.…

  17. Living and Learning: "Does Residence Hall Roommate Placement of Traditional Freshman Students at MSOE Effect Their Satisfaction with the Residence Halls?"

    Science.gov (United States)

    Breese, William Ellis, II

    2012-01-01

    The purpose of this study is to examine if residence hall roommate placement of traditional freshman students at MSOE affects their satisfaction with the residence halls. The idea behind this study is that if residence hall roommate placement is done purposefully, with the participation of incoming freshmen through appropriate placement…

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    How to combat infectious diseases: The role of Science Academies · Academy Public Lecture and INSA–Leopoldina Lecture by Prof. Jörg Hacker, President, German Academy of Sciences Leopoldina. 4 December, 2017, 4 PM Faculty Hall, Indian Institute ...

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    How to combat infectious diseases: The role of Science Academies · Academy Public Lecture and INSA–Leopoldina Lecture Talk by Prof. Jörg Hacker, President, German Academy of Sciences Leopoldina. 4 December, 2017, 4 PM Faculty Hall, Indian Institute ...

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    How to combat infectious diseases: The role of Science Academies · Academy Public Lecture and INSA–Leopoldina Lecture by Prof. Jörg Hacker, President, German Academy of Sciences Leopoldina. 4 December, 2017, 4 PM Faculty Hall, Indian Institute ...

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    How to combat infectious diseases: The role of Science Academies · Academy Public Lecture and INSA–Leopoldina Lecture by Prof. Jörg Hacker, President, German Academy of Sciences Leopoldina. 4 December, 2017, 4 PM Faculty Hall, Indian Institute ...

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    How to combat infectious diseases: The role of Science Academies · Academy Public Lecture and INSA–Leopoldina Lecture by Prof. Jörg Hacker, President, German Academy of Sciences Leopoldina. 4 December, 2017, 4 PM Faculty Hall, Indian Institute ...

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    Welcome to the Indian Academy of Sciences Blog! Through this new initiative, we hope to tell you about the activities of the Academy, the publications, the lectures – all what we do. Of course, these are all reported on the website of the Academy (www.ias.ac.in) but here we discuss things informally. We hope to reach a ...

  11. Teaching Science in Engineering Freshman Class in Private University in Jordan

    Science.gov (United States)

    Hawarey, M. M.; Malkawi, M. I.

    2012-04-01

    A United Nations initiative for the Arab region that established and calculated National Intellectual Capital Index has shown that Jordan is the wealthiest Arab country in its National Human Capital Index (i.e. metrics: literacy rate, number of tertiary schools per capita, percentage of primary teachers with required qualifications, number of tertiary students per capita, cumulative tertiary graduates per capita, percentage of male grade 1 net intake, percentage of female grade 1 net intake) and National Market Capital Index (i.e. metrics: high-technology exports as a percentage of GDP, number of patents granted by USPTO per capita, number of meetings hosted per capita) despite its low ranking when it comes to National Financial Capital (i.e. metric: GDP per capita). The societal fabric in Jordan fully justifies this: the attention paid to education is extreme and sometimes is considered fanatic (e.g. marriage of a lot of couples needs to wait until both graduate from the university). Also, the low financial capital has forced a lot of people to become resourceful in order to provide decent living standard to their beloved ones. This reality is partially manifested in the sharp increase in the number of universities (i.e. 10 public and 20 private ones) relative to a population of around 6.5 million. Once in an engineering freshman classroom, it is totally up to the lecturers teaching science in private Jordanian universities to excel in their performance and find a way to inject the needed scientific concepts into the students' brains. For that, clips from movies that are relevant to the topics and truthful in their scientific essence have been tested (e.g. to explain the pressure on humans due to rapidly increasing "g" force, a clip from the movie "Armageddon" proved very helpful to Physics 101 students, and entertaining at the same time), plastic toys have also been tested to illustrate simple physical concepts to the same students (e.g. a set called The Junior

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    2013-11-30

    Nov 30, 2013 ... Science Academies' Summer Research Fellowship Programme for. Students and Teachers – 2014. Sponspored by. Indian Academy of Sciences, Bangalore. Indian National Science Academy, New Delhi. The National Academy of Sciences, India, Allahabad. The three national science academies offer ...

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  14. Academy Engages Incarcerated Youths

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    Zehr, Mary Ann

    2010-01-01

    It's not easy to keep young people on task for learning in a youth prison, but David Domenici, the principal of the Maya Angelou Academy, a charter-like school serving incarcerated juveniles, is trying to do it while at the same time creating a model program for improving educational services for young offenders. Located at the New Beginnings…

  15. Peninsula Academies Program.

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    Sequoia Union High School District, Redwood City, CA.

    THE FOLLOWING IS THE FULL TEXT OF THIS DOCUMENT: The Peninsula Academies program helps educationally disadvantaged youth overcome the handicaps of low academic achievement, lack of skills, and chronic unemployment. This is accomplished by providing a high school curriculum that is clearly related to work, training in specific job skills, emphasis…

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    2017年9月21日 ... accepted. We enclose the pricelist and order form (soft copies are also available in the Academy website: (http://www.ias.ac.in/Journals/Overview/) and we would generally like to recommend all Journals for your library. Please pay the full subscription fee for renewal/new order before 31 December 2017.

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    Manjunath

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    Dec 26, 2016 ... various parameters such as Impact Factors, Citation Indices, etc., provided by international agencies. Needless to mention, these Journals are priced ... available in the Academy website: www.ias.ac.in) and we would generally like to recommend all. Journals for your library. The prices are inclusive of ...

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    Notice inviting quotations from manpower agencies for housekeeping staff and Housekeeping Services for Sadashivanagar and Jalahalli offices. The Indian Academy of Sciences was founded and registered as a society in 1934 with the aim to promote the progress and uphold the cause of science, both in pure and applied ...

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    Nov 15, 2015 ... Information and Announcements. Science Academies' Refresher Course on. Crystallography, Mineralogy, Igneous Petrology and. Thermodynamics, Sedimentology and. Economic Geology at Indian Academy of Sciences Facility, Jalahalli, Bengaluru. 11–24 December 2015. Sponsored by Indian Academy ...

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    ... 7. GET STARTED AAPM... the Voice of Pain Medicine Become part of the distinguished multimodal, interdisciplinary community of pain medicine clinicians. Join Today! Welcome The American Academy of ...

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    Home; Journals; Indian Academy of Sciences Conference Series. MURILO S BAPTISTA. Articles written in Indian Academy of Sciences Conference Series. Volume 1 Issue 1 December 2017 pp 17-23 Proceedings of the Conference on Perspectives in Nonlinear Dynamics - 2016. Interpreting physical flows in networks as a ...

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    Home; Journals; Indian Academy of Sciences Conference Series. JOYDEEP SINGHA. Articles written in Indian Academy of Sciences Conference Series. Volume 1 Issue 1 December 2017 pp 195-203 Proceedings of the Conference on Perspectives in Nonlinear Dynamics - 2016. Spatial splay states in coupled map lattices ...

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    Home; Journals; Indian Academy of Sciences Conference Series. BEDARTHA GOSWAMI. Articles written in Indian Academy of Sciences Conference Series. Volume 1 Issue 1 December 2017 pp 51-60 Proceedings of the Conference on Perspectives in Nonlinear Dynamics - 2016. Inferring interdependencies from short ...

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    Home; Journals; Indian Academy of Sciences Conference Series. GIOVANNA ZIMATORE. Articles written in Indian Academy of Sciences Conference Series. Volume 1 Issue 1 December 2017 pp 35-41 Proceedings of the Conference on Perspectives in Nonlinear Dynamics - 2016. RQA correlations on real business cycles ...

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    Ethical Guidelines and Procedures document. Posted on 17 January 2017. A revised version of the document 'Scientific Values: Ethical Guidelines and Procedures' has been produced by the Academy's Panel on Scientific Values. For more details, see the Academy Committee on Scientific Values page.

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    Home; Journals; Indian Academy of Sciences Conference Series. SERGEY BREZETSKIY. Articles written in Indian Academy of Sciences Conference Series. Volume 1 Issue 1 December 2017 pp 187-194 Proceedings of the Conference on Perspectives in Nonlinear Dynamics - 2016. Chimera-like states generated by large ...

  3. Indian Academy of Sciences Conference Series | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Indian Academy of Sciences Conference Series. G AMBIKA. Articles written in Indian Academy of Sciences Conference Series. Volume 1 Issue 1 December 2017 pp 9-15 Proceedings of the Conference on Perspectives in Nonlinear Dynamics - 2016. Dynamics of slow and fast systems on complex ...

  4. Indian Academy of Sciences Conference Series | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Indian Academy of Sciences Conference Series. TOMASZ KAPITANIAK. Articles written in Indian Academy of Sciences Conference Series. Volume 1 Issue 1 December 2017 pp 187-194 Proceedings of the Conference on Perspectives in Nonlinear Dynamics - 2016. Chimera-like states generated by large ...

  5. Science self-efficacy of African Americans enrolled in freshman level physical science courses in two historically black institutions

    Science.gov (United States)

    Prihoda, Belinda Ann

    2011-12-01

    Science education must be a priority for citizens to function and be productive in a global, technological society. African Americans receive fewer science degrees in proportion to the Caucasian population. The primary purposes of this study were to determine the difference between the pretest and posttest science self-efficacy scores of African-American nonscience majors, the difference between the pretest and posttest science self-efficacy scores of African-American science majors, the relationship between science self-efficacy and course grade, the relationship between gender and science self-efficacy score, and the relationship between science self-efficacy score and course withdrawal. This study utilized a Likert survey instrument. All participants were enrolled in freshman level courses in the physical sciences at a historically black institution: a college or university. Participants completed the pretest survey within two weeks after the 12th class day of the semester. Initially, 458 participants completed the pretest survey. The posttest was administered within two weeks before the final exam. Only 245 participants completed the posttest survey. Results indicate that there is a difference in science self-efficacy of science majors and nonscience majors. There was no significant difference between the pretest and posttest science self-efficacy scores of African-American science majors and nonscience majors. There was no significant relationship between science self-efficacy and course grade, gender and science self-efficacy score, and course withdrawal and science self-efficacy score.

  6. Freshman College Students' Reasons for Enrolling in and Anticipated Benefits from a Basic College Physical Education Activity Course.

    Science.gov (United States)

    Lackman, Jeremy; Smith, Matthew Lee; McNeill, Elisa Beth

    2015-01-01

    Given the rise in US obesity rates in adulthood, efforts are needed to assess physical activity engagement during the college years as a strategy to promote a lifetime of being physically active. This study identifies the reasons incoming college freshman enrolled in basic physical education activity courses (BPEAC) and the perceived benefits they anticipated receiving as a result of course participation. Data collected from 302 college freshmen in September 2013 were analyzed. A paper-based questionnaire was administered to 78% of BPEAC sections offered at a large Southeastern University. Frequencies were presented for all participants, which were then compared by sex and course type. Kappa statistics were calculated to examine the concordance between participants' reasons for enrolling in the course and the benefits they anticipated from course enrollment. Diverse physical, mental, social, and academic reasons for enrolling in BPEAC were reported by study participants. Varied anticipated benefits from course participation were reported as well. Reported enrollment reasons and anticipated benefits differed by sex and course type. High concordance between matched enrollment reasons and anticipated benefits was observed. Implications highlight the need for universities to provide quality BPEAC, promote high-quality instruction, and offer a wide variety of physical education courses to meet the diverse needs of students.

  7. About | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    About. 83rd Annual Meeting - Indian Academy of Sciences. The 83rd Annual Meeting of the Indian Academy of Sciences is being held at Shillong, hosted by the North-Eastern Hill University, during 3 – 5 November 2017. The two and a half days' deliberation will see the participation of many Fellows and Associates of the ...

  8. currsci | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the teaching of the theory of evolution

  9. cur | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Ethical Guidelines and Procedures document. Posted on 17 January 2017. A revised version of the document 'Scientific Values: Ethical Guidelines and Procedures' has been produced by the Academy's Panel on Scientific Values. For more details, see the Academy Committee on Scientific Values page.

  10. jarc | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Ethical Guidelines and Procedures document. Posted on 17 January 2017. A revised version of the document 'Scientific Values: Ethical Guidelines and Procedures' has been produced by the Academy's Panel on Scientific Values. For more details, see the Academy Committee on Scientific Values page.

  11. Home | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    2016-12-23

    Dec 23, 2016 ... The three-day 82nd Annual Meeting of the Indian Academy of Sciences, hosted by the Indian Institute of Science Education and Research, Bhopal, saw enthusiastic participation of members of the scientific and teaching community across the nation, with 91 Fellows and Associates of the Academy and 41 ...

  12. Resonance | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Resonance. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the teaching ...

  13. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Logo of the Indian Academy of Sciences. Indian Academy of ... 2013 pp 571-589. An evolutionary approach for colour constancy based on gamut mapping constraint satisfaction ... A new colour constancy algorithm based on automatic determination of gray framework parameters using neural network · Mohammad Mehdi ...

  14. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Toggle navigation. Logo of the Indian Academy of Sciences. Indian Academy of Sciences. Home · About IASc · History · Memorandum of Association ... Volume 31 Issue 5 October 2006 pp 621-633. Minimizing total costs of forest roads with computer-aided design model · Abdullah E Akay · More Details Abstract Fulltext PDF.

  15. Fellowship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1948 Section: Plant Sciences. Patel, Makanji Kalyanji. Date of birth: 6 November 1899. Specialization: Plant Pathology. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies ...

  16. Fellowship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Date of birth: 11 January 1906. Date of death: 22 July 1969. Specialization: Agricultural Statistics, Genetics, Plant Breeding, Agronomy. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the teaching of ...

  17. Fellowship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1952 Section: Plant Sciences. Ghose, Robert Lal Mohan M.Sc. Specialization: Plant Breeding, Rice. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the ...

  18. Home | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    The Mid-Year Meetings held during June/July at Bengaluru and the Annual Meetings held during November at different scientific institutions in the country are the two major annual events of the Academy in this context. The events every year see enthusiastic participation of the Fellowship of the Academy along with ...

  19. Associateship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Date of birth: 17 May 1981. Address during Associateship: Dept. of Mathematics, University of Delhi, Delhi 110 007. Contact: Email: tanvi1705@rediffmail.com. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of ...

  20. Associateship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Date of birth: 30 December 1961. Specialization: String Theory Address during Associateship: Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be ...

  1. Indian Academy of Sciences: Home

    Indian Academy of Sciences (India)

    Indian Academy of Sciences. The Indian Academy of Sciences, founded as a Society by Professor C. V. Raman on 27 April 1934, aims to promote the advancement of science in both pure and applied branches through the support of original research and the dissemination of scientific knowledge to the community.

  2. Associateship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Date of birth: 27 August 1960. Specialization: Polymer Science Address during Associateship: IPC Department, Indian Institute of Science, Bangalore 560 012. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will ...

  3. Home | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    2016-11-06

    Nov 6, 2016 ... The events every year see enthusiastic participation of the Fellowship of the Academy along with researchers, teachers, students and other invitees across the nation. The 82nd Annual Meeting of the Academy is being organized during 4th–6th November 2016 at the Indian Institute of Science Education ...

  4. Fellowship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    The process of election of Fellows is described in the statutes. Nomination forms are provided only to the Fellows and are not made available on the Academy website. Those pursuing research in India are eligible to be nominated. The last date for receipt of new nominations is 31st May. The Academy offers only fellowship ...

  5. Gallery | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; ·; About; ·; Speakers; ·; Schedule; ·; Gallery · Logo of the Indian Academy of Sciences; For Participants; ·; Downloads; ·; Contact. Gallery. Day 1. 3rd Nov 2017. Friday · Day 2. 4th Nov 2017. Saturday · Day 3. 5th Nov 2017. Sunday. © 2017 Indian Academy of Sciences, Bengaluru.

  6. Associateship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Change in email domain name. Posted on 26 August 2016. The domain part of the email address of all email addresses used by the office of Indian Academy of Sciences, including those of the staff, the journals, various programmes, and Current Science, has changed from 'ias.ernet.in' (or 'academy.ias.ernet.in') to ...

  7. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Sadhana- Academy Proceedings in Engineering Sciences published by Indian Academy of Sciences, Bangalore is a monthly peer reviewed journal, published 12 issues per year from 2016. It is a leading journal of Engineering Sciences in India since 1978. From 2007, Sadhana is co-published with the International ...

  8. About | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Indian Academy of Sciences (IASc), Bengaluru: The Indian Academy of Sciences, as envisioned by its founder- Sir C V Raman, is devoted to the promotion and the upholding of the cause of science through diverse activities that aim to recognize and reward scientific efforts and talents. Science education programs are also ...

  9. Fellowship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Elected: 1947 Section: Mathematical Sciences. Varma, Rama ... Specialization: Operational Research, Pure & Applied Mathematics. YouTube · Twitter ... Thus, for example, the address office@ias.ernet.in (or office@academy.ias.ernet.in) has changed to office@ias.ac.in (without the string 'academy'). Please take note of this ...

  10. Initiatives | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Initiatives. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the teaching of ...

  11. Events | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Events. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the teaching of the ...

  12. Fellowship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the teaching of the theory of evolution

  13. About | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    About. Agenda—82nd Annual Meeting - Indian Academy of Sciences. The 82nd Annual Meeting of the Indian Academy of Sciences is being held at Bhopal, hosted by the Indian Institute of Science Education and Research, during during 4th – 6th November 2016. The two and a half days' deliberation will see the ...

  14. sadhna | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; sadhna. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the teaching of ...

  15. conf | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Academy Public Lecture and INSA–Leopoldina Lecture by Prof. Jörg Hacker, President, German Academy of Sciences Leopoldina. 4 December, 2017, 4 PM Faculty Hall, Indian Institute. Associates – 2017. Posted on 30 August 2017. Click here to see the list · 83rd Annual Meeting. Posted on 01 December 2017.

  16. j | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Ethical Guidelines and Procedures document. Posted on 17 January 2017. A revised version of the document 'Scientific Values: Ethical Guidelines and Procedures' has been produced by the Academy's Panel on Scientific Values. For more details, see the Academy Committee on Scientific Values page.

  17. Associateship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Ethical Guidelines and Procedures document. Posted on 17 January 2017. A revised version of the document 'Scientific Values: Ethical Guidelines and Procedures' has been produced by the Academy's Panel on Scientific Values. For more details, see the Academy Committee on Scientific Values page.

  18. pra | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; pra. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the teaching of the ...

  19. Journals | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the teaching of the theory of evolution

  20. Associateship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Most recent entry 16 January 2017. The Academy regrets to report the passing of: Roshko, Prof. Anatol C V Vishveshwara (see YouTube video: Eureka with C. V. Vishveshwara) Mandayam Anandampillai Lakshmi Thathachar Chokkappa Kempanna. © 2017 Indian Academy of Sciences, Bengaluru. Contact | Site index.

  1. Indian Academy of Sciences: Home

    Indian Academy of Sciences (India)

    Founded in 1934 by Sir C V Raman the Indian Academy of Sciences, Bangalore was registered as a Society on 27 April 1934 with the main objective of promoting the progress and upholding the cause of science. The Academy began functioning with 65 Founding Fellows and the formal inauguration took place at the ...

  2. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Information for Authors. Sadhana. Sadhana- Academy Proceedings in Engineering Sciences published by Indian Academy of Sciences, Bangalore is a monthly peer reviewed journal, published 12 issues per year from 2016. It is a leading journal of Engineering Sciences in India since 1978. From 2007, Sadhana is ...

  3. Fellowship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1962 Honorary. Szigeti, Prof. Gyorgy. Date of birth: 29 January 1905. Date of death: 26 November 1978. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the ...

  4. Science Academies' Sixtieth Refresher Course in Experimental ...

    Indian Academy of Sciences (India)

    IAS Admin

    Science Academies' Sixtieth Refresher Course in. Experimental Physics. May 27 to June 11 2014. Government College (A), Rajamundry. Sponsored by Indian Academy of Sciences, Bangalore,. Indian National Science Academy, New Delhi. The National Academy of Sciences, India, Allahabad. The fifty-ninth Course will be ...

  5. Classification of Incoming Freshman in a Public University Based on the Variables of Academic Performance, Use of Digital Technology

    Directory of Open Access Journals (Sweden)

    Javier Organista Sandoval

    2012-05-01

    Full Text Available During the first semester of 2008 a research study was conducted with incoming freshman in the School of Administrative and Social Sciences (FCAyS—acronym in Spanish of the Ensenada campus of the Universidad Autónoma de Baja California (UABC. The purpose was to characterize the new students based on academic achievement (grade point averages in high school and the first semester of college, family context (parents’ schooling and use of technology (computers and the Web. A survey of technology use developed within the framework of the research was applied to a sample of 438 students. The results show that the majority of the students are female (2 out of 3 and that 4 out of 5 have computers at home. About 80% of the students showed an intermediate level of proficiency in computer technology and the Web. Two classifying techniques were employed: CHAID and a cluster analysis to explore the development of patterns based on the above-mentioned variables. The result of the applied CHAID analysis highlights the importance of the variables of gender, parental schooling and level of immersion in the Web for the classification. The cluster analysis (k-means generated four clusters; of these, cluster 1, which had the lowest average grades and the highest levels of computer and Web immersion, is noteworthy, because it suggests a non-educational use of technological resources. In contrast, cluster 4 presented the highest grade point average in college, a moderate level of computer use and a low level of immersion in the Web. This suggests a greater commitment to academics by reduced use of the computer and the Web for recreational purposes.

  6. Evaluation of gingival bleeding awareness by comparison of self-reports and clinical measurements of freshman dental students.

    Science.gov (United States)

    Baser, Ulku; Germen, Meliha; Erdem, Yelda; Issever, Halim; Yalcin, Funda

    2014-07-01

    The aims of this descriptive, cross-sectional investigation were to evaluate the gingival health awareness of dental students by comparing their clinical gingival bleeding scores and self-reports, and to compare differences in awareness between males and females. In total, 100 (51 males, 49 females) freshman dental students were included in the study. Periodontal indices recorded were: Presence of plaque percentage (plaque index [PI], %), percentage of sites of bleeding on probing (BOP, %), probing depth, and community periodontal index (CPI). Percent agreement, kappa agreement, sensitivity, and specificity were calculated by comparing their self-reported gingival bleeding and BOP%. The self-reports of gingival bleeding exhibited statistically significant correlations with BOP% in females (r = 0.42, P = 0.003). Female students showed a higher degree of awareness when kappa agreement, 0.23 (males: 0.16, females: 0.39), sensitivity, 48% (males: 42%, females: 51%), and specificity, 95% (males: 90%, females: 100%) were calculated. Although male dental students had higher PI and CPI scores, there was no significant difference by gender in the clinical measurements. According to our results, the validity of self-reported gingival bleeding was higher among dental students than in previous population-based studies. Female dental students showed a higher degree of awareness than males of their gingival health. Half of the included dental students could not differentiate whether they had gingival bleeding when there was actual bleeding. More emphasis should be given to the education of dental students regarding the relationship between gingival bleeding and active periodontal disease.

  7. Indian Academy of Sciences Conference Series | Indian Academy of ...

    Indian Academy of Sciences (India)

    . Articles written in Indian Academy of Sciences Conference Series. Volume 1 Issue 1 December 2017 pp 157-161 Proceedings of the Conference on Perspectives in Nonlinear Dynamics - 2016. Dynamics of nonlinear oscillators with ...

  8. Indian Academy of Sciences Conference Series | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Indian Academy of Sciences Conference Series; Volume 1; Issue 1. Chimera-like states generated by large perturbation of synchronous state of coupled metronomes. SERGEY BREZETSKIY DAWID DUDKOWSKI PATRYCJA JAROS JERZY WOJEWODA KRZYSZTOF CZOLCZYNSKI YURI MAISTRENKO ...

  9. Indian Academy of Sciences Conference Series | Indian Academy of ...

    Indian Academy of Sciences (India)

    . Articles written in Indian Academy of Sciences Conference Series. Volume 1 Issue 1 December 2017 pp 77-83 Proceedings of the Conference on Perspectives in Nonlinear Dynamics - 2016. Structure of simplicial complexes of graphs ...

  10. ayurvis.pdf | dvdocs | academy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held from 29–30 June 2018 in Infosys, Mysuru ...

  11. GMCrops-interAcademy-report-updated.pdf | inter academy ...

    Indian Academy of Sciences (India)

    error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held from 29–30 June 2018 in Infosys, Mysuru ...

  12. astrophys.pdf | dvdocs | academy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held from 29–30 June 2018 in Infosys, Mysuru ...

  13. Kos16.pdf | multimedia | academy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held from 29–30 June 2018 in Infosys, Mysuru ...

  14. sadasivan pop.html | academy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held from 29–30 June 2018 in Infosys, Mysuru ...

  15. Academy Distance Learning Tools (IRIS) -

    Data.gov (United States)

    Department of Transportation — IRIS is a suite of front-end web applications utilizing a centralized back-end Oracle database. The system fully supports the FAA Academy's Distance Learning Program...

  16. Associateship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    ACADEMY PUBLIC LECTURE: How Things Break – The Mechanics of Dynamic Fracture. Posted on 16th February 2018. by Prof. Krishnaswamy Ravi-Chandar. in Faculty Hall, Indian Institute of Science. on 23 February 2018, 1500 event poster ...

  17. Sustainable Materials Management Web Academy

    Science.gov (United States)

    The Sustainable Materials Management (SMM) Web Academy series is a free resource for SMM challenge participants, stakeholders, and anyone else interested in learning more about SMM principles from experts in the field.

  18. Fellowship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held from 29–30 June 2018 in Infosys, Mysuru ...

  19. Initiatives | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held from 29–30 June 2018 in Infosys, Mysuru ...

  20. Events | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Events. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of the Academy will be held from 29–30 June ...