1,527 research outputs found
Model Predictive BESS Control for Demand Charge Management and PV-Utilization Improvement
Adoption of battery energy storage systems for behind-the-meters application
offers valuable benefits for demand charge management as well as increasing
PV-utilization. The key point is that while the benefit/cost ratio for a single
application may not be favorable for economic benefits of storage systems,
stacked services can provide multiple revenue streams for the same investment.
Under this framework, we propose a model predictive controller to reduce demand
charge cost and enhance PV-utilization level simultaneously. Different load
patterns have been considered in this study and results are compared to the
conventional rule-based controller. The results verified that the proposed
controller provides satisfactory performance by improving the PV-utilization
rate between 60% to 80% without significant changes in demand charge (DC)
saving. Furthermore, our results suggest that batteries can be used for
stacking multiple services to improve their benefits. Quantitative analysis for
PV-utilization as a function of battery size and prediction time window has
also been carried out.Comment: Accepted in: Conference on Innovative Smart Grid Technology (ISGT),
Washington, DC, 201
Synthesis and characterization of thermally stable poly(amide-imide)-montmorillonite nanocomposites based on bis(4-carboxyphenyl)-N,N'-pyromellitimide acid
Two new poly(amide-imide)-montmorillonite reinforced nanocomposites containing bis(4-carboxyphenyl)-N,N'-pyromellitimide acid moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) as a source of polymer matrix was synthesized by the direct polycondensation reaction of  bis(4-carboxyphenyl)-N,N'-pyromellitimide acid with 4,4'-diamino diphenyl sulfone in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PAI-nanocomposite films with 10 and 20% silicate particles were characterized by FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposites films were investigated by using UV-Vis spectroscopy, thermal gravimetry analysis (TGA) and water uptake measurements. KEYWORDS: Bis(4-carboxyphenyl)-N,N'-pyromellitimide acid moiety, Poly(amide-imide)-montmorillonite nanocomposite, Thermal properties Bull. Chem. Soc. Ethiop. 2013, 27(1), 95-104.DOI: http://dx.doi.org/10.4314/bcse.v27i1.1
The effect of changing position and early ambulation after cardiac catheterization on patients' outcomes: A single-blind randomized controlled trial
Background: Cardiac catheterization is the gold standard diagnostic test for coronary heart diseases. In order to minimize the post-procedure complications, patients are restricted to prolonged bed rest that is always accompanied by fatigue and discomfort. Objective: The aim of this study was to assess the effect of changing position and early ambulation on the level of comfort, satisfaction, and fatigue and on the amount of bleeding and hematoma after cardiac catheterization. Participants: A sample of 70 patients, who had undergone a non-emergency 6-French cardiac catheterization via the femoral artery from September to November, 2006. Methods: In a single-blind randomized controlled trial, each patient was randomly assigned to either the control or experimental group. The patients' position in the experimental group was intermittently changed during the first 6 h after catheterization. Seven hours after the procedure, they were allowed to be ambulated and to undertake their self care activities. A pillow was placed under the patients' bodies. Patients in the control group were managed as routine; they were restricted to a 10-24 h bed rest bed rest in supine position with the affected leg straight and immobilized and a sand bag on the puncture site for at least 8 h. The levels of comfort, satisfaction and fatigue, and the amount of bleeding and hematoma were measured at regular intervals after the procedure. Results: The patients in the experimental group had significantly higher comfort and satisfaction and lower fatigue levels than the control group at 3, 6, 8 h and the next morning after catheterization (P 0.05). Conclusion: The results of this study showed that the levels of comfort, satisfaction and fatigue after catheterization are related to the duration of bed rest and patients' position in bed. Changing patients' position accompanied by early ambulation after cardiac catheterization are associated with increasing comfort and satisfaction levels and decreasing the level of fatigue without increasing the amount of bleeding and hematoma. © 2009 Elsevier Ltd. All rights reserved
Identification of SSR and RAPD markers associated with QTLs of winter survival and related traits in Brassica napus L.
Because of importance of winter survival in winter type of Brassica napus, this study was performed to identify the QTLs controlling winter survival and related traits using SSR and RAPD markers. For this,an F2:3 population of 200 families derived from crossing between cv. ‘SLMO46’ (winter type and cold resistant) and cv. ‘Quantum’ (spring type and susceptible to low temperature) were used. Wintersurvival (WS), leaves per plant in rosette stage (L/P), crown wet weight (CWW), crown dry weight (CDW) and crown water content (CWC) were measured in F3 families. 350 SSR primer pairs and 250 RAPDprimers were used to assess the parental polymorphism. The 32 SSR primer pairs and 47 RAPD polymorphic markers between parental lines were used to screen F2 individuals. Linkage map was constructed using polymorphic markers. The markers were assigned into 14 linkage groups with total length of 1199.1 cM and an average distance of 17.13 cM between adjacent markers. The relationship between measured traits and genotypic data was analyzed using CIM method and totally 12 putative QTLs were detected for studied traits. The explained phenotypic variance by identified QTLs ranged between 0.5 and 11%. The identified QTLs had positive and negative additive effects and transferred from both parents to F2 plants and F3 families. Some of these QTLs located in the same genomic regions
Seasonal Variation in Exposure Level of Types A and B Ultraviolet Radiation: An Environmental Skin Carcinogen
Background: The main source of ultraviolet radiation (UVR) is the sun, affecting organs such as the skin, eyes, and immune system. According to American Conference of Governmental Industrial Hygienist (ACGIH) reports, the amount of UVR reaching the Earth’s surface is increasing yearly and is responsible for an increase in solar radiation‑related diseases. Aims: To investigate the amount of UVR reaching the Earth’s surface and understand the risk of UVR on disease among outdoor laborers in one of the central provinces of Iran.Materials and Methods: Arak city was divided into two geographic areas, and the weekly measurement of UVR was done in three locations) asphalt, grass and rooftop). To measure UVR, Hanger UV spectrometer, standard deviation (SD8‑A), and SD8‑B detectors were used. Amounts of UVR for a consecutive year and varying weather conditions were measured. Finally, values obtained were compared to ACGIH standards. Results: The minimum and maximum levels of UV type A radiation occurred in April 1.27 (0.724) W/m2 and September 7.147 (4.128) W/m2, these figures for UV type B were in March–April 0.005 (0.003) and September 0.083 (0.077). The maximum UVR is received between 11 and 15 o’clock.Conclusions: In the central cities of Iran, the minimum and maximum UV type A and B is received in March–April and in September, respectively. Based on the results, the angular position of the sun in the sky, cloud cover, and height from ground level affected the amount of UVR received, but the geographic locations studied did not.  Keywords: Outdoor Job, Skin Cancer, Carcinogen, Ultraviolet radiation, Ultraviolet A, Ultraviolet B, Ira
Karyological study of the medicinal plant Papaver rhoeas from northwest of Iran
Karyotype and morphology of mitotic chromosomes in six populations of the medicinal plant Papaver rhoeas collected from various geographical locations of the northwest of Iran were studied. Chromosome characteristics were measured from 10 complete metaphase cells using micromeasure software. The results showed that P. rhoeas is a diploid species with 2n=2x=14 chromosomes. The karyotype consisted of seven pairs of submetacentric chromosomes with one pairs of SAT chromosome (chromosome 2) having a secondary constriction at the end of its short arm. Karyological characteristics of all the materials studied were similar to each other; however, there were some variations on chromosome arm ratios and relative lengths among the different populations. All of the populations are placed on 4A class of Stebbin’s asymmetry categories.Key words: Biodiversity, chromosome analysis, medicinal plants, Papaveraceae
In vitro propagation of four Iranian grape varieties: Influence of genotype and pretreatment with arbuscular mycorrhiza
There is a great demand for table grape saplings, mainly for commercial varieties indicating that micropropagation could be an effective method for their mass propagation. Internal contamination in woody plant species is an important problematic issue and arbuscular mycorrhizal fungi (AMF) have been known as potential plant biological protectors. In the present study, the glasshouse grown mother plants of four grape varieties ('Asgari', 'Khalili', 'Keshmeshi', and 'Shahroudi') were inoculated with AMF as pre-treatment. The fungi strains were Glomus mosseae, G. fasciculatum, G. intraradices and a mixture of all three species. The comparative in vitro performance of these genotypes was evaluated following optimization of in vitro growth conditions for each genotype. Furthermore, the positive effect of AMF inoculation of stock plant on micropropagation process was studied. Changes in biochemical features (total chlorophylls, total phenols and total sugars), growth parameters (root length and total leaf area) and in vitro behavior of AMF pretreated as well as control explants were recorded. The mycorrhizal association with grapevine roots was confirmed following root staining and evaluation of colonization rate. The results revealed a distinct difference and clear genotypic effect on various in vitro parameters of studied grape genotypes. The utilized inocula were found to have the capability of mycorrhizal association with grapevine roots, leading to enhancing phenolics as a defense mechanism, increasing sugars and chlorophyll and finally growth of whole plant corresponding to the grape variety and AMF strain. These results confirmed that health and physiological conditions of the stock plants are important parameters for in vitro grape culture establishment and suggest the integration of mycorrhizal technology with tissue culture to accomplish better results
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