615 research outputs found
Performance Analysis of Hybrid Power Plant (Wind and Solar) in Baron Techno Park Gunung Kidul Yogyakarta
Renewable energy is generated through the conversion process of energy sources which are abundant in the earth such as wind, sun, heat, rain, geothermal, hydro, ocean water and others into an environmentally friendly form of energy. This kind of energy does not cause negative effects to the environment when being used. Therefore, by using renewable energy, the earth is not polluted. This is a major step in controlling global warming, which is one of the elements that leads to environmental degradation. The use of renewable energy sources is indispensable. One great opportunity for future renewable energy is the integration of various sources of energy (hybrid power plant). This paper presents the analysis performance of hybrid power plant (wind and solar) installed in the area of Baron Techno Park. Modeling with HOMER (Hybrid Optimization Model for Electric Renewable) Version 3.8.1 was done with two conditions, first was a grid connected and the second was an off-grid condition. The first system modeling for the installed system capacity NPC and COE had the lowest price for the off-grid condition being 0.0213. For the 20,887.76 and the COE was - 1,685.87 / year, and electricity production being was 63,55 kWh / year. With the grid, the contribution of Baron Techno Park hybrid power plants could lower carbon dioxide gas up to 82.63 kg/year for operating systems and 202.63 kg/year for systems with installed capacity
On the use of Li isotopes as a proxy for water–rock interaction in fractured crystalline rocks: A case study from the Gotthard rail base tunnel
We present Li isotope measurements of groundwater samples collected during drilling of the 57 km long Gotthard rail base tunnel in Switzerland, to explore the use of Li isotope measurements for tracking water–rock interactions in fractured crystalline rocks at temperatures of up to 43 °C. The 17 groundwater samples originate from water-conducting fractures within two specific crystalline rock units, which are characterized by a similar rock mineralogy, but significantly different fluid composition. In particular, the aqueous Li concentrations observed in samples from the two units vary from 1–4 mg/L to 0.01–0.02 mg/L. Whereas δ7Li values from the unit with high Li concentrations are basically constant (δ7Li = 8.5–9.1‰), prominent variations are recorded for the samples from the unit with low Li concentrations (δ7Li = 10–41‰). This observation demonstrates that Li isotope fractionation can be highly sensitive to aqueous Li concentrations. Moreover, δ7Li values from the unit with low Li concentrations correlate well with reaction progress parameters such as pH and [Li]/[Na] ratios, suggesting that δ7Li values are mainly controlled by the residence time of the fracture groundwater. Consequently, 1D reactive transport modeling was performed to simulate mineral reactions and associated Li isotope fractionation along a water-conducting fracture system using the code TOUGHREACT. Modeling results confirm the residence time hypothesis and demonstrate that the absence of δ7Li variation at high Li concentrations can be well explained by limitation of the amount of Li that is incorporated into secondary minerals. Modeling results also suggest that Li uptake by kaolinite forms the key process to cause Li isotope fractionation in the investigated alkaline system (pH >9), and that under slow flow conditions (<10 m/year), this process is associated with a very large Li isotope fractionation factor (ε ≈ −50‰). Moreover, our simulations demonstrate that for simple and well-defined systems with known residence times and low Li concentrations, δ7Li values may help to quantify mineral reaction rates if more thermodynamic data about the temperature-dependent incorporation of Li in secondary minerals as well as corresponding fractionation factors become available in the future. In conclusion, δ7Li values may be a powerful tool to track water–rock interaction in fractured crystalline rocks at temperature higher than those at the Earth’s surface, although their use is restricted to low Li concentrations and well defined flow systems
Effect of Load Growth on PLTH Baron Techno Park Performance
The reliability of stand-alone and hybrid power plant systems was dependent on electrical loads that the system must supply. For example, on renewable energy sources (RES), Reviews of those systems needs to be calculated well before the development process. One of the most important processes in the initial calculation is the electrical load that must be supplied by the system. The electrical load has a major influence on the amount of power generating capacity. A power plant that has higher electricity production than the load to be fulfilled was considered capable of meeting the system electrical load requirements. However, in terms of the reliability, it is considered as a loss because it will affect the life of the components and the high cost of operating from the system. Therefore, this research discusses the effect of load growth on hybrid power plant system performance of Baron Techno Park. The result of the research shows that the total electricity production of Baron Techno Park hybrid power plant system is 319.695 kWh/year with Net Present Cost (NPC) is 0.64/kWh. Total electricity consumption of the PLTH Baron Techno Park is 67.413 kWh/year with total excess electrical energy is 245,547 kWh/year. Load growth of 5%, 10%, 15%, and 20% of the total current load affect the consumption of electric energy, excess electrical energy, and COE. The higher the load growth will affect the total electricity consumption that is increasingly higher so that the total excess electrical energy is lower. This research found that the performance of the system is not influenced by load growth. The highest performance of the system is resulted by the wind turbine of 72.62%, followed by solar panels of 18.82%, and biodiesel of 8.56%
Reconstructing Tonian seawater ⁸⁷Sr/⁸⁶Sr using calcite microspar
The Tonian Period followed a long interval of relative stasis and led into the climatic extremes and biological radiations of multicellular life during the Cryogenian and Ediacaran Periods, respectively. However, despite its pivotal situation, it remains relatively understudied, in large part due to the lack of robust age constraints. A combination of fossil evidence, radiometric ages, and isotopic constraints reveal that carbonate strata on the North China craton were deposited between ca. 980 and ca. 920 Ma, thereby filling a gap in marine archives. Here we present 87Sr/86Sr data from selected calcite microspar cements, which filled early diagenetic “molar tooth” cracks, along with data from demonstrably well-preserved bulk carbonate samples. These new data show that seawater 87Sr/87Sr rose in stages from ~0.7052 at ca. 980 Ma to ~0.7063 by ca. 920 Ma, after which a return to low values coincided with the eruption of the Dashigou large igneous province across the North China craton. We also present a new Neoproterozoic seawater 87Sr/86Sr curve, which reveals that the general trend toward higher 87Sr/87Sr during the Tonian Period was checked repeatedly by the input of less-radiogenic strontium from a series of eruptive events, both coincident with and prior to the main breakup of Rodinia. The weathering of Tonian volcanic provinces has been linked to higher carbon burial, glaciation, and oxygenation due to the high phosphorus content of flood basalts. Here we show that the weathering of major volcanic provinces affected material fluxes and ocean chemistry much earlier than previously envisaged
Initial United States experience with the Paracor HeartNet⁎⁎Paracor Medical, Inc, Sunnyvale, Calif. myocardial constraint device for heart failure
ObjectiveThis study was undertaken to review the initial results and surgical safety data for the US Food and Drug Administration safety and feasibility trial of the Paracor HeartNet (Paracor Medical, Inc, Sunnyvale, Calif.) myocardial constraint device.MethodsPatients with New York Heart Association functional class II or III heart failure underwent device implantation (n = 21) through a left minithoracotomy.ResultsThe average age was 53 years (31–72 years). There were 18 men and 3 women, and 17 patients had nonischemic etiology of heart failure. Mean heart failure duration was 8.3 years (1.4-18.8 years). Average ejection fraction was 22% (11%-33%), with an average left ventricular end-diastolic dimension of 74 mm (55-94 mm). Previous medical therapy included angiotensin-converting enzyme inhibitors, β-blockers, diuretics, digoxin, and aldosterone receptor blockers. At implantation, 17 patients had implantable electronic devices: 1 biventricular pacemaker, 11 biventricular pacemakers with cardioverter-defibrillators, and 5 implantable cardioverter-defibrillators. Patient comorbidities included hypertension in 10 cases, diabetes mellitus in 8, myocardial infarction in 1, and ventricular tachycardia in 8. Mean operative time was 68 minutes (42–102 minutes), and implantation time averaged 15 minutes (5–51 minutes). The average time to ambulation was 1.6 days (1–4 days). The intensive care unit stay averaged 3.3 days (1–16 days), and hospital stay averaged 6.3 days (4–16 days). Atrial fibrillation occurred in 2 patients, and there were 2 in-hospital deaths.ConclusionsThe Paracor device can be implanted in patients with heart failure and reduced left ventricular function with a high degree of success. Significant surgical complications were infrequent. The initial US experience supports the conduct of a randomized, controlled, pivotal trial
Modular Design via Multiple Anion Chemistry of the High Mobility van der Waals Semiconductor Bi₄O₄SeCl₂
Making new van der Waals materials with electronic or magnetic functionality is a chemical design challenge for the development of two-dimensional nanoelectronic and energy conversion devices. We present the synthesis and properties of the van der Waals material Bi4O4SeCl2, which is a 1:1 superlattice of the structural units present in the van der Waals insulator BiOCl and the three-dimensionally connected semiconductor Bi2O2Se. The presence of three anions gives the new structure both the bridging selenide anion sites that connect pairs of Bi2O2 layers in Bi2O2Se and the terminal chloride sites that produce the van der Waals gap in BiOCl. This retains the electronic properties of Bi2O2Se while reducing the dimensionality of the bonding network connecting the Bi2O2Se units to allow exfoliation of Bi4O4SeCl2 to 1.4 nm height. The superlattice structure is stabilized by the configurational entropy of anion disorder across the terminal and bridging sites. The reduction in connective dimensionality with retention of electronic functionality stems from the expanded anion compositional diversity
Curcumin induces the apoptosis of human monocytic leukemia THP-1 cells via the activation of JNK/ERK Pathways
<p>Abstract</p> <p>Background</p> <p>Curcumin is a principal compound of turmeric, commonly used to treat tumors and other diseases. However, its anti-cancer activity in human acute monocytic leukemia THP-1 cells is not clear. This study aimed to study the anti-cancer effect and action of curcumin on THP-1 cells.</p> <p>Methods</p> <p>THP-1 parental cells and PMA-treated THP-1 cells, were used as <it>in vitro </it>models to evaluate the anti-cancer effect and mechanism of curcumin. Apoptosis and its mechanism were evaluated by WST-1, flow cytometry and Western blotting. MAPK inhibitors were used to further confirm the molecular mechanism of curcumin-induced THP-1 cell apoptosis.</p> <p>Results</p> <p>Curcumin induced cell apoptosis of THP-1 cells as shown by cell viability, cell cycle analysis and caspase activity. Curcumin significantly increased the phosphorylation of ERK, JNK and their downstream molecules (c-Jun and Jun B). Inhibitor of JNK and ERK reduced the pro-apoptotic effect of curcumin on THP-1 cells as evidenced by caspase activity and the activation of ERK/JNK/Jun cascades. On the contrary, the pro-apoptotic effect of curcumin was abolished in the differentiated THP-1 cells mediated by PMA.</p> <p>Conclusions</p> <p>This study demonstrates that curcumin can induce the THP-1 cell apoptosis through the activation of JNK/ERK/AP1 pathways. Besides, our data suggest its novel use as an anti-tumor agent in acute monocytic leukemia.</p
Obesity and craniofacial variables in subjects with obstructive sleep apnea syndrome: comparisons of cephalometric values
<p>Abstract</p> <p>Background</p> <p>The aim of this paper was to determine the most common craniofacial changes in patients suffering Obstructive Sleep Apnea Syndrome (OSAS) with regards to the degree of obesity. Accordingly, cephalometric data reported in the literature was searched and analyzed.</p> <p>Methods</p> <p>After a careful analysis of the literature from 1990 to 2006, 5 papers with similar procedural criteria were selected. Inclusion criteria were: recruitment of Caucasian patients with an apnea-hypopnea index (AHI) >10 as grouped in non-obese (Body Mass Index – [BMI] < 30) <it>vs</it>. obese (BMI ≥ 30).</p> <p>Results</p> <p>A low position of the hyoid bone was present in both groups. In non-obese patients, an increased value of the ANB angle and a reduced dimension of the cranial base (S-N) were found to be the most common finding, whereas major skeletal divergence (ANS-PNS ^Go-Me) was evident among obese patients. No strict association was found between OSAS and length of the soft palate.</p> <p>Conclusion</p> <p>In both non-obese and obese OSAS patients, skeletal changes were often evident; with special emphasis of intermaxillary divergence in obese patients. Unexpectedly, in obese OSAS patients, alterations of oropharyngeal soft tissue were not always present and did not prevail.</p
Up-regulation of macrophage wnt gene expression in adenoma-carcinoma progression of human colorectal cancer
Defects in the APC-β-catenin pathway are common in colon cancer. We investigated whether aberrant regulation of upstream ligands stimulating this pathway occur in colon cancer. Using RNAase protection analysis, six out of eight wnt genes were expressed in 14 matched cases of normal, adenomatous and malignant colorectal tissues. Wnt 2 and wnt 5a were significantly up-regulated in the progression from normal through adenoma to carcinoma. Transcripts for wnts 4, 7b, 10b and 13, but not wnt 2 and wnt 5a were detected in several colorectal cell lines. In situ hybridization demonstrated that wnt 2 and wnt 5a transcripts were mainly in the lamina propria/stroma region with labelling predominantly in macrophages. Immunostaining with CD68 confirmed the wnt-expressing cells as macrophages. These results show a major difference in wnt expression in colon cancer compared to colon adenomas and suggest stromal wnt expression may play a role in tumour progression. © 1999 Cancer Research Campaig
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