285 research outputs found

    Day-Ahead Offering Strategy In The Market For Concentrating Solar Power Considering Thermoelectric Decoupling By A Compressed Air Energy Storage

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    Due to limited fossil fuel resources, a growing increase in energy demand and the need to maintain positive environmental effects, concentrating solar power (CSP) plant as a promising technology has driven the world to find new sustainable and competitive methods for energy production. The scheduling capability of a CSP plant equipped with thermal energy storage (TES) surpasses a photovoltaic (PV) unit and augments the sustainability of energy system performance. However, restricting CSP plant application compared to a PV plant due to its high investment is a challenging issue. This paper presents a model to assemble a combined heat and power (CHP) with a CSP plant for enhancing heat utilization and reduce the overall cost of the plant, thus, the CSP benefits proved by researches can be implemented more economically. Moreover, the compressed air energy storage (CAES) is used with a CSP-TES-CHP plant in order that the thermoelectric decoupling of the CHP be facilitated. Therefore, the virtual power plant (VPP) created is a suitable design for large power grids, which can trade heat and electricity in response to the market without restraint by thermoelectric constraint. Furthermore, the day-ahead offering strategy of the VPP is modeled as a mixed integer linear programming (MILP) problem with the goal of maximizing the profit in the market. The simulation results prove the efficiency of the proposed model. The proposed VPP has a 2% increase in profit and a maximum 6% increase in the market electricity price per day compared to the system without CAES

    Effects of dietary probiotic (Lactobacillus plantarum) on body composition, serum biochemical parameters and liver enzymes of Asian sea bass (Lates calcalifer, Bloch 1790)

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    In the current study, the effects of different levels of probiotics, Lactobacillus plantarum in the diet of Asian sea bass, Lates calcarifer on body composition, serum biochemical parameters (glucose, cholesterol, triglyceride and albumin) and liver enzymes (lactate dehydrogenase, alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase) were investigated. This experiment was carried out with three treatments and a control group for a period of four weeks. The treatments were included 0, 1×106, 2×106, 3×106 colony forming unit (CFU) gram probiotic in each gram of basic diet. Fish with an average weight of 50.26 ±0.89 grams were randomly distributed in tanks and in each tank stocked 20 pieces of fish. Feeding was done twice a day. The obtained results indicated that the use of different levels of probiotic in diet of Asian sea bass had no significant effects on serum biochemical parameters and liver enzymes. The different levels of probiotic did not affect protein, ash and moisture values between the treatments and the control group (P> 0.05). Moreover, fat value in the fish T2 and T3 was significantly higher (P< 0.05) than the fish control and T1. Also, nitrogen free extract (NFE) value varied significantly (P < 0/05) between the control and the fish T3. Overall, this study indicated that this probiotic had no significant effect on some blood biochemical parameters and liver enzyme, but at the high level can positively influence on body composition of Asian sea bass

    Sentinel node biopsy in early breast cancer patients with palpable axillary node

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    Background: Sentinel lymph node biopsy is a reliable method for evaluation of the axillary lymph node status in early stage breast cancer patients with non-palpable lymph nodes. The present study evaluated the status of sentinel and non-sentinel lymph nodes in T1T2 patients with palpable axillary lymph nodes. Materials and Methods: One hundred and two women with early breast cancer were investigated in this study. Patients were selected for axillary sentinel lymph node biopsy and then surgery.Then the rates of false negative and true positive, and diagnostic accuracy of sentinel lymph nodes biopsy were evaluated. In addition, the hormone receptors status of the tumor was determined through IHC and data was analyzed in SPSS21. Results: In this study, the mean age of the patients was 49 years, 85 had invasive ductal carcinoma in their pathology reports, 77 were ER/PR positive, 30 HER2 positive and 9.8 triple negative and 69 had KI6714 (p<0.002) whereas the rate of involvement was lower in triple negative patients. Conclusion: Sentinel node biopsy can be used in a significant percentage of breast cancer patients with palpable and reactive axillary lymph nodes. © 2020 Asian Pacific Organization for Cancer Prevention

    Measurement of peripheral dose to the pelvic region and the associated risk for cancer development after breast intraoperative electron radiation therapy

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    This study aimed to measure the received dose to the pelvic region of patients during breast intraoperative electron radiation therapy (IOERT). Furthermore, we compared the findings with those of external beam radiation therapy. Finally, secondary ovarian and uterus cancer risks following breast IOERT were estimated. In the current study, the received dose to the pelvic surface of 18 female patients during breast IOERT boosts were measured by thermoluminescent dosimeter (TLD-100) chips. All patients were treated with 12 Gy given in a single fraction. To estimate the dose to the ovary and uterus of the patients, conversion coefficients for depth from the surface dose were obtained in a Rando phantom. Given the received dose to the pelvic region of the patients, secondary ovarian and uterus cancer risks following breast IOERT were estimated. The received doses to the ovary and uterus surface of the patients were 0.260 ±0.155 mGy to 31.460 ±6.020 mGy and 0.485 ±0.122 mGy to 22.387 ±15.476 mGy, respectively. Corresponding intra-pelvic (ovary and uterus) regional doses were 0.012 ±0.007 mGy to 1.479 ±0.283 mGy and 0.027 ±0.001 mGy to 1.164 ±0.805 mGy, respectively. Findings demonstrated that the ratio of the received dose by the pelvic surface to the regional dose during breast IOERT was much less than external beam radiation therapy. The mean of the secondary cancer risks for the ovary in 8 and 10 MeV electron beam energies were 135.722 ±117.331 �10 -6 and 69.958 ±28.072 �10 -6 , and for the uterus were 17.342 ±10.583 �10 -6 and 2.971 ±3.604 �10 -6 , respectively. According to our findings, the use of breast IOERT in pregnant patients can be considered as a safe radiotherapeutic technique, because the received dose to the fetus was lower than 50 mGy. Furthermore, IOERT can efficiently reduce the unnecessary dose to the pelvic region and lowers the risk of secondary ovarian and uterus cancer following breast irradiation. © 2019 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved

    Effects of epidural lidocaine analgesia on labor and delivery: A randomized, prospective, controlled trial

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    BACKGROUND: Whether epidural analgesia for labor prolongs the active-first and second labor stages and increases the risk of vacuum-assisted delivery is a controversial topic. Our study was conducted to answer the question: does lumbar epidural analgesia with lidocaine affect the progress of labor in our obstetric population? METHOD: 395 healthy, nulliparous women, at term, presented in spontaneous labor with a singleton vertex presentation. These patients were randomized to receive analgesia either, epidural with bolus doses of 1% lidocaine or intravenous, with meperidine 25 to 50 mg when their cervix was dilated to 4 centimeters. The duration of the active-first and second stages of labor and the neonatal apgar scores were recorded, in each patient. The total number of vacuum-assisted and cesarean deliveries were also measured. RESULTS: 197 women were randomized to the epidural group. 198 women were randomized to the single-dose intravenous meperidine group. There was no statistical difference in rates of vacuum-assisted delivery rate. Cesarean deliveries, as a consequence of fetal bradycardia or dystocia, did not differ significantly between the groups. Differences in the duration of the active-first and the second stages of labor were not statistically significant. The number of newborns with 1-min and 5-min Apgar scores less than 7, did not differ significantly between both analgesia groups. CONCLUSION: Epidural analgesia with 1% lidocaine does not prolong the active-first and second stages of labor and does not increase vacuum-assisted or cesarean delivery rate

    Grain refinement of Al-Mg-Sc alloy by ultrasonic treatment

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    In foundry practice, ultrasonic treatment has been used as an efficient technique to achieve grain refinement in aluminium and magnesium alloys. This article shows the strong effect of pouring temperature and ultrasonic treatment at various temperatures on the grain refinement of Al-1 wt% Mg-0.3 wt% Sc alloy. Without ultrasonic treatment, a fine grain structure was obtained at the pouring temperature of 700 °C. The average grain size sharply decreases from 487 ± 20 to 103 ± 2 μm when the pouring temperature decreases from 800 to 700 °C. Ultrasonic vibration proved to be a potential grain refinement technique with a wide range of pouring tem- perature. A microstructure with very fine and homogeneous grains was obtained by applying ultrasonic treatment to the melt at the temperature range between 700 and 740 °C, before pouring. Cavitation-enhanced hetero- geneous nucleation is the mechanism proposed to explain grain refinement by ultrasound in this alloy. Moreover, ultrasonic treatment of the melt was found to lead to cast samples with hardness values similar to those obtained in samples submitted to precipitation hardening, suggesting that ultrasonic treatment can avoid carrying out heat treatment of cast parts.This research was supported by The Project Bridging The Gap, funded by the Erasmus Mundus External Cooperation Window Programme. Acknowledgements also to the University of Minho, for the provision of research facilities

    Differential scanning calorimetry (DSC) and thermodynamic prediction of liquid fraction vs temperature for two high-performance alloys for semi-solid processing (Al-Si-Cu-Mg (319s) and Al-Cu-Ag (201))

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    There is a need to extend the application of semi-solid processing (SSP) to higher performance alloys such as 319s (Al-Si-Cu-Mg) and 201 (Al-Cu-Ag). The melting of these two alloys was investigated using differential scanning calorimetry (DSC) and thermodynamic prediction. The alloys had been processed by magneto-hydrodynamic (MHD) stirring before receipt to produce a microstructure suitable for SSP. The DSC results for the as-received MHD material were compared with those for material which has been taken through a complete DSC cycle and then reheated for a second DSC run. The effects of microsegregation were then analyzed. A higher liquid fraction for a particular temperature is found in the second DSC run than the first. Microstructural observations suggest this is because the intermetallics which form during the first cooling cycle tend to co-located. Quaternary and ternary reactions then occur during the second DSC heat and the co-location leads to enhanced peaks. The calculated liquid fraction is lower with 10 K/min DSC heating rate comparing with 3 K/min at a given temperature. The DSC scan rate must therefore be carefully considered if it is to be used to identify temperature parameters or the suitability of alloys for SSP. In addition, the starting material for DSC must represent the starting material for the SSP. With thermodynamic prediction, the equilibrium condition will provide better guidance for the thixoforming of MHD stirred starting material than the Scheil condition. The Scheil mode approximates more closely with a strongly microsegregated state

    A composite transcriptional signature differentiates responses towards closely related herbicides in Arabidopsis thaliana and Brassica napus

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    In this study, genome-wide expression profiling based on Affymetrix ATH1 arrays was used to identify discriminating responses of Arabidopsis thaliana to five herbicides, which contain active ingredients targeting two different branches of amino acid biosynthesis. One herbicide contained glyphosate, which targets 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), while the other four herbicides contain different acetolactate synthase (ALS) inhibiting compounds. In contrast to the herbicide containing glyphosate, which affected only a few transcripts, many effects of the ALS inhibiting herbicides were revealed based on transcriptional changes related to ribosome biogenesis and translation, secondary metabolism, cell wall modification and growth. The expression pattern of a set of 101 genes provided a specific, composite signature that was distinct from other major stress responses and differentiated among herbicides targeting the same enzyme (ALS) or containing the same chemical class of active ingredient (sulfonylurea). A set of homologous genes could be identified in Brassica napus that exhibited a similar expression pattern and correctly distinguished exposure to the five herbicides. Our results show the ability of a limited number of genes to classify and differentiate responses to closely related herbicides in A. thaliana and B. napus and the transferability of a complex transcriptional signature across species
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