Some fixed point results on S-metric spaces Shahraki, Maryam; Sedghi, Shaban; Aleomraninejad, S. M. A. ...
Acta universitatis sapientiae. Mathematica,
11/2020, Letnik:
12, Številka:
2
Journal Article
Recenzirano
Odprti dostop
In this paper, a general form of the Suzuki type function is considered on S- metric space, to get a fixed point. Then we show that our results generalize some old results.
In the present work, the energy and exergy analysis of Kostolac power plant in Serbia is presented. The primary objectives of this article are to analyze the system components separately and to ...identify and quantify the sites having the largest energy and exergy losses. The energy and exergy efficiency is calculated using the plant operating data from the plant at different loads. The load variation is studied with the data at 100% and 60% of full load. Moreover, the effects of the load variations are calculated in order to obtain a good insight into this analysis. The performance of the plant is estimated by a component-wise modeling, and a detailed break-up of energy and exergy losses for the considered plant has been presented. The results show that energy losses have mainly occurred in the condenser where 421 MW is lost to the environment while only 105.78 MW has been lost from the boiler. Nevertheless, the irreversibility rate of the boiler is higher than the irreversibility rates of the other components. The percentage ratio of the exergy destruction to the total exergy destruction was found to be maximum in the boiler system (88.2%) followed by the turbines (9.5%), and then the forced draft fan condenser (0.5%). In addition, the calculated thermal efficiency based on the lower heating value of fuel was 39% while the exergy efficiency of the power cycle was 35.77%.
Objective We sought to define the prevalence of definitive end-states and their determinants in children with double-outlet right ventricle. Methods We performed a clinical record review of 393 ...children with double-outlet right ventricle presenting to our institution from 1980 to 2000. Results Double-outlet right ventricle classification was as follows: subaortic ventricular septal defect with or without pulmonary stenosis in 47%, subpulmonic ventricular septal defect in 23%, noncommitted ventricular septal defect in 26%, and doubly committed ventricular septal defect in 4%. Hypoplastic ventricles were present in 39%, pulmonary stenosis was present in 65%, and aortic arch obstruction was present in 24%. Biventricular repair was performed in 194 patients (55%) at a median age of 10 months (range: birth to 14.0 years), and the Fontan operation (n = 182; 23%) was performed at a median age of 3.7 years (range: 6 months to 14.9 years). Results improved over time ( P < .001). Factors discriminating among end-states included younger patient age at presentation ( P < .001), lower weight ( P < .001), and adequacy of left-sided heart structures, especially the size of the left ventricle ( P < .001), aortic arch ( P < .001), and mitral valve ( P = .004). For complex double-outlet right ventricle, Rastelli-type repair increased early reintervention risk ( P = .04) and late post-repair mortality ( P = .02), whereas the arterial switch operation increased early post-repair mortality ( P = .02) with a benefit of improved late post-repair survival. Conclusions Biventricular repair, especially Rastelli-type reconstruction, is associated with higher late mortality and reintervention than is Fontan repair. The wisdom of extending biventricular repair to borderline anatomic candidates with hypoplastic left-sided structures or a nonsubaortic ventricular septal defect is questionable.
The marine dinoflagellate
Protoceratium reticulatum has been recently identified as a source for the disulfated polyether toxin, yessotoxin (YTX), and may pose a risk to human health, aquaculture ...development and coastal environments. The requirements of
P. reticulatum for selenium, iron and cobalt were assessed in culture.
P. reticulatum was grown in nutrient enriched seawater (1/10 GP medium) without selenium or with 0.003 and 0.0003 μM selenium added; without iron or with 0.076 and 0.0076 μM iron added; and without cobalt or with 0.008 μM cobalt added. Test flasks were monitored for growth rate, cell yield and YTX production.
P. reticulatum was found to exhibit a strong requirement for both selenium and iron. Growth rate and cell yield in treatments without added selenium were significantly (
P<0.05) reduced to 60.2% (
μ=0.15 day
−1) and 20.2% (4942 cell ml
−1), respectively, of those with selenium added (
μ=0.23 day
−1 and 24, 387 cell ml
−1). YTX production was significantly increased by addition of selenium in two of three transfers tested. Cells of
P. reticulatum subjected to medium without selenium added showed morphological changes observable at the light microscope level which included enlarged cell size. The diameter of cells in medium without selenium added were significantly (
P<0.05) enlarged to 36.7±0.90 μm compared to cells in the medium with selenium added, 27.5±1.25 μm. Growth rate and cell yield in treatments without added iron were also significantly reduced to 70.1% (
μ=0.16 day
−1) and 34.2% (8003 cells ml
−1), respectively, of those with iron added (
μ=0.23 day
−1 and 23,416 cells ml
−1). No significant effect on YTX production was measured. In contrast to selenium and iron, no limitation of growth or cell yield or differences in YTX production were observed for flasks without cobalt as compared to those with cobalt added. The possibility that harmful algal events of
P. reticulatum may be influenced by selenium or iron in neritic waters is discussed.
We used the recently developed time-symmetrized, two-state vector model to investigate the intermediate stages of the electron capture into the Rydberg states (
n
A
≫
1
,
l
A
=
0
−
3
,
m
A
=
0
) of ...multiply charged ions SVI, ClVII and ArVIII, with polarized core charges
Z
=
6
, 7 and 8, respectively, escaping solid surfaces at low velocities. Within the framework of the model, the two wave functions are used to describe the system at intermediate stages; the corresponding probabilities and rates are based on the calculation of the mixed flux. The simple analytical formulae derived for the neutralization rates enable us to analyze the localization of the process and to calculate the neutralization distances. In the pointlike core approximation, the rates are comparable with the available coupled-angular-mode results. The neutralization distances follow the classical predictions for all considered Rydberg states with exception of the states with critical quantum numbers
n
A
=
n
c
, mainly populated via tunneling mechanism; the corresponding values are larger than it is predicted by the classical overbarrier model. Inclusion of core polarization significantly reduces the neutralization distances.
The change in concentration of the disulfated polyether yessotoxin (YTX) produced by a culture of the marine dinoflagellate
Protoceratium reticulatum was measured in laboratory experiments under ...light and dark conditions. Experimental cultures were inoculated and grew at a growth rate of 0.14
d
−1 until stationary phase was reached, after approximately 21 days. Cultures were maintained in the stationary phase until 31 days after inoculation. Cells of
P. reticulatum contained a concentration of approximately 10–15
pg YTX cell-1 during stationary phase but this was considerably lower (<5
pg cell-1) during the growth phase. Low amounts of 45-hydroxy-YTX were also detected. At day 32,
P. reticulatum was killed by cooling to 1
°C (confirmed microscopically) and YTX concentrations were measured periodically under light and dark conditions. YTX concentrations decreased rapidly to approximately 10% of the initial concentration within the first 3 days and depleted to near zero within a week in the light treatment. In the dark environment, YTX persisted longer with approximately 10% of the initial YTX concentration still remaining after 18 days.
Human infection by Dirofilaria repens in Serbia has been increasing steadily. The first case was reported in 1971, presented in the form of a single subcutaneous nodule on the back of a young boy. As ...established by a literature search, eight additional cases were reported until mid-2001. The most frequent site of infection was subcutaneous tissue, with the exception of two cases, in which parasites were found in subconjunctiva and epididymis. Our study, conducted from 2001 to 2008, encompasses 19 new cases. Most of them (63.1%) presented as ocular or periocular infections, in which the parasite was typically found under the conjunctiva. In other cases a parasitic nodule was localized in the temporal region of the head, epididymis, testicle, abdomen, breast or arm. The diagnosis was made by morphological and histological analysis of the extracted intact worms and parasite sections from the tissue. Morphology of the filarial worms was well preserved in more than half of the cases (12/19) and there was never more than one parasite found inside the lesions. Adult worms and immature nematodes were observed in nine and seven cases, respectively. Furthermore, in two cases microfilariae were discovered inside the pseudocoelom, sections of the female reproductive tubes filled with clearly visible larval stages. Dirofilaria repens infection was diagnosed by its morphological features (17/19) or by performing polymerase chain reactions (PCR) using paraffin-embedded tissues (2/19) in the cases where the morphology was insufficient for identification and the parasites had been determined initially as Dirofilaria spp. The amplified 246 bp PCR product showed that the worms were D. repens.
The growth of Cyclotella meneghiniana was examined at temperatures between 13 and 28°C at 3°C intervals. Growth increased linearly with temperature to a growth maximum at 25°C, with growth decreasing ...at 28°C.
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