212 research outputs found
Management of Renewable Energy for a Shared Facility Controller in Smart Grid
© 2016 IEEE. This paper proposes an energy management scheme to maximize the use of solar energy in the smart grid. In this context, a shared facility controller (SFC) with a number of solar photovoltaic panels in a smart community is considered that has the capability to schedule the generated energy for consumption and trade to other entities. In particular, a mechanism is designed for the SFC to decide on the energy surplus, if there is any, that it can use to charge its battery and sell to the households and the grid based on the offered prices. In this regard, a hierarchical energy management scheme is proposed with a view to reduce the total operational cost to the SFC. The concept of a virtual cost is introduced that aids the SFC to estimate its future operational cost based on some available current information. The energy management is conducted for three different cases, and the optimal cost to the SFC is determined for each case by the theory of maxima and minima. A real-time algorithm is proposed to reach the optimal cost for all cases, and some numerical examples are provided to demonstrate the beneficial properties of the proposed scheme
A competitive design and material consideration for fabrication of polymer electrolyte membrane fuel cell bipolar plates
The bipolar plate is one of the most significant components of a polymer electrolyte membrane (PEM) fuel cell, and contributes substantially to the cost structure and the weight of the stacks. A number of graphite polymer composites with different fabrication techniques have been reported in the literature. Graphite composites show excellent electromechanical properties and chemical stability in acidic environments. Compression and injection molding are the most common manufacturing methods being used for mass production. In this study, a competitive bipolar plate design and fabrication technique is adopted in order to develop a low-cost and light-weight expanded graphite (EG) polymer composite bipolar plate for an air-breathing PEM fuel cell. Cutting molds are designed to cut fuel flow channels on thin expanded graphite (EG) sheets (0.6 mm thickness). Three separate sheets, with the flow channel textures removed, are glued to each otherbyacommercialconductiveepoxytobuildasinglebipolarplate. Thefinalproducthasadensity of 1.79 g/cm3. A bipolar plate with a 20 cm2 active area weighs only 11.38 g. The manufacturing cost is estimated to be 7.77 $/kWe, and a total manufacturing time of 2 minutes/plate is achieved with lab-scale fabrication. A flexural strength value of 29 MPa is obtained with the three-point bending method. A total resistance of 22.3 milliohms.cm2 is measured for the three-layer bipolar plate. We presume that the suggested design and fabrication process can be a competitive alternate for the small-scale, as well as mass production of bipolar plates
Fungal endophyte misidentified as Neurospora crassa.
The endophytic fungus isolate, ZP5SE, recently described in Rehman et al. 2008 was misidentified identified as Neurospora crassa. The 28S ribosomal gene sequence of the isolate shows 100% sequence similarity with GenBank accession Neurospora crassa M38154
Exploring Effectiveness of Principles of Business Writing at Graduate Level in Pakistan
Abstract Business writing is a creative and dynamic process that primarily motivated the researchers to investigate the learners' individual differences and sort out their learning hindrances. The current study explores the problems faced by the students, while leaning principles of effective writing at BBA level. Business writing is critical aspect of business industry. The Survey was conducted to get response at COMSATS Institute Sahiwal in Pakistan. The SPSS version 16 was used to analyze the data. The results of the study revealed that students at graduate level face countless problems in preparing effective business drafts. It suggested that principles of business writing are essential to improve business life
Urban wastewater: A valuable resource for agriculture - A case study from Haroonabad, Pakistan
Waste waters / Irrigation water / Water reuse / Economic analysis / Soil properties / Households / Water availability / Water use / Water quality / Groundwater / Public health / Risks / Case studies
Parity-time-symmetric coupled microring lasers operating around an exceptional point
The behavior of a parity-time (PT) symmetric coupled microring system is
studied when operating in the vicinity of an exceptional point. Using the
abrupt phase transition around this point, stable single-mode lasing is
demonstrated in spectrally multi-moded micro-ring arrangements.Comment: 5 pages, 6 figure
Professional Reflection a Cradle of Student Teacher’s Professional Development
The emergence of connotation of reflective practices within the field of teacher education has resulted in a greater need for student teachers to consider the effectiveness of their teaching practices to meet the increased levels of accountability that is associated with their professional development. This paper provided an examination of the potential contribution of reflection for the development of effective teaching skills among student teachers during practicum course by utilizing both quantitative and qualitative research methods. This paper aimed to study the potential links between reflective practices and professional development of student teachers. Paper also examines the reflective practices of student teachers. The results revealed that reflections on professional practices supported student teachers to improve their relations with students and colleagues. Student teachers reported that they got self-awareness, they were able to understand the knowledge-in-action which enhanced student teachers skills for delivery of lesson during practicum.
DOI: 10.5901/mjss.2015.v6n3s1p37
Challenges and some new directions in channel coding
Three areas of ongoing research in channel coding are surveyed, and recent developments are presented in each area: Spatially coupled low-density parity-check (LDPC) codes, nonbinary LDPC codes, and polar coding. © 2015 KICS
Optical Properties of Vanadium in 4H Silicon Carbide for Quantum Technology
We study the optical properties of tetravalent vanadium impurities in 4H
silicon carbide (4H SiC). Emission from two crystalline sites is observed at
wavelengths of 1.28 \mum and 1.33 \mum, with optical lifetimes of 163 ns and 43
ns. Group theory and ab initio density functional supercell calculations enable
unequivocal site assignment and shed light on the spectral features of the
defects. We conclude with a brief outlook on applications in quantum photonics
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