Surface Tension and Surface Tension Assessment of Ag-Au-Cu Ternary and Sub-Binary Alloy Systems

A brief review of measurement techniques and theoretical studies on the surface tension alloy and mixture has been presented in the present study. It is clear that the experimental determination of thermodynamic and thermophysical properties of both solid and especially liquid alloys at high temperature cases is frequently difficult technologically. In addition to this, a lack of experimental data concerning thermophysical properties of Ag-Au, Au-Cu, and Ag-Cu sub-binary systems is obvious. The theoretical thermophysical data of the Ag-Au-Cu ternary alloy systems are very scarce in the literature. Thus, the surface tensions of the alloys just mentioned above for cross sections z = xAg/xAu = 1/3, 1/1, 3/1, 2/5, and 5/2, respectively, and their sub-binary systems are much simply calculated from the surface tensions of the Ag-Au, Au-Cu, and Ag-Cu sub-binary systems by using geometric models, such as Muggianu, Kohler, Toop, and GSM (Chou’s general solution model) and Butler’s equation. The predicted results in the present study show rather an agreement with the experimental results of the alloys. Therefore, it is inferred that the obtained surface tension curves for the Ag-Au-Cu ternary alloy at 1381 K are reasonable with especially those calculated from the Toop model

Estimation of delay and vehicle stops at signalized intersections using artificial neural network

Delay and number of vehicle stops are important indicators that define the level of service of a signalized intersection. Therefore, they are usually considered for optimizing the traffic signal timing. In this study, ANNs are employed to model delay and the number of stops estimation at signalized intersections. Intersection approach volumes, cycle length and left turn lane existence were utilized as input variables since they could easily be obtained from field surveys. On the other hand, the average delay and the number of stops per vehicle were used as the output variables for the ANNs models. Four-leg intersections were examined in this study.  Approach volumes including turning volumes are randomly generated for each lane of these intersections, then the traffic simulation program was run 196 times with each generated data. Finally, average delay and the number of stops per vehicle were obtained from the simulations as outputs. In this study, various network architectures were analyzed to get the best architecture that provides the best performance. The results show that the ANNs model has potential to estimate delays and number of vehicle stops

Improvement of the Wastewater Biodegradability by Means of Photocatalytic and Wet Oxidation Processes in the Presence of Hydrogen Peroxide

In this study, the effectiveness of photocatalytic oxidation (PO) and wet oxidation (WO) processes as a pre-treatment step on improvement of biodegradability and colour removal of mixture of raw domestic and pre-treated industrial wastewaters, have been evaluated. More oxygen was obtained by H2O2 (as an oxidant in WO and PO processes) than stoichiometric demand. PO of the wastewater was carried out by illumination of the wastewater with UV lamp (at room temperature, atmospheric pressure, 16.5 h reaction time) and WO of the wastewater was carried out by means of thermal oxidation at autoclave conditions (at 118–120 oC, 1.9–2 bar, 3 h reaction time). 1 g L–1 TiO2 in PO process and 0.2 mg L–1 Cu++ in WO process were used as catalyst. The results obtained from experiments were not compared with each other due to the difference between the quality and quantity of the used catalyst and the consumed energy. Colour removal efficiency was 33 % for WO process and 77.6 % for PO process. By applying WO process, 72.7 % increase in the reaction rate coefficient describing the degradability of organic compounds in wastewater was obtained, but this value was 34.5 % in PO process

Multidimensional Index Modulation for 5G and Beyond Wireless Networks

This study examines the flexible utilization of existing IM techniques in a comprehensive manner to satisfy the challenging and diverse requirements of 5G and beyond services. After spatial modulation (SM), which transmits information bits through antenna indices, application of IM to orthogonal frequency division multiplexing (OFDM) subcarriers has opened the door for the extension of IM into different dimensions, such as radio frequency (RF) mirrors, time slots, codes, and dispersion matrices. Recent studies have introduced the concept of multidimensional IM by various combinations of one-dimensional IM techniques to provide higher spectral efficiency (SE) and better bit error rate (BER) performance at the expense of higher transmitter (Tx) and receiver (Rx) complexity. Despite the ongoing research on the design of new IM techniques and their implementation challenges, proper use of the available IM techniques to address different requirements of 5G and beyond networks is an open research area in the literature. For this reason, we first provide the dimensional-based categorization of available IM domains and review the existing IM types regarding this categorization. Then, we develop a framework that investigates the efficient utilization of these techniques and establishes a link between the IM schemes and 5G services, namely enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communication (URLLC). Additionally, this work defines key performance indicators (KPIs) to quantify the advantages and disadvantages of IM techniques in time, frequency, space, and code dimensions. Finally, future recommendations are given regarding the design of flexible IM-based communication systems for 5G and beyond wireless networks.Comment: This work has been submitted to Proceedings of the IEEE for possible publicatio

Comparison of posterior cranial fossa morphometric measurements in Chiari type I patients with and without syrinx cavity on magnetic resonance imaging

Purpose: To compare the posterior fossa measurements of Chiari type I malformation (CHM1) patients with and without syrinx and with a control group. Material and methods: The patients with syrinx were divided into 2 groupd according to syrinx width/cord width (S/C) ratios: group 1 – S/C ratio 50%. The length of the clivus, the AP length of the foramen magnum, the AP length of the posterior fossa, the perpendicular distance between the McRae line and (a) the splenium of corpus callosum, (b) the pons, and (c) the fastigium of the 160 patients and of the 160 control patients were statistically compared. In addition, the measurements of the patients with and without syrinx, according to the S/C ratio, were statistically compared. Results: Syrinx was present in 59 (36.8 %) of the 160 patients. The S/C ratio was 50% in 29 (49.1%) of them. All the measurements in the patient group, except of the AP length of the foramen magnum, were statistically significantly lower than in the control group (p = 0.001). There was no signif icant difference in the measurements of the patients with syrinx group 1 and the patients without syrinx, but the AP length of posterior fossa was statistically significantly lower in the patients with syrinx group 2 than the patients without syrinx (p = 0.03). Conclusion: The S/C ratio can be a guide to the underlying aetiology

Profile differences of medical doctors from three different hospitals in Turkey concerning burnout, job satisfaction, and depression

Objective: This study aimed to compare job satisfaction, burnout, and depression scores of medical doctors from different regions in Turkey. Method: A cross-sectional study was performed during October 2013 in three cities from Turkey. Participants were asked to self-administer a demographic information questionnaire, the Minnesota Satisfaction Questionnaire (Internal work satisfactionIWS and External work satisfaction-EWS), the Beck Depression Inventory (BDI), the Maslach Burnout Inventory (MBI), Maslach Emotional Exhaustion Score (MEES), and Maslach Personal Accomplishment Score (MPAS). Results: Mean (±SD) Total work satisfaction score was 66.2±12.6. 118 participants had BDI scores of 10 or less while 40 participants had 11 or higher scores. Proportions for poor depersonalization, emotional exhaustion, and personal accomplishment were 18.6% (n=29), 5.8% (n=9), and 81.9% (n=127) respectively. There were significant differences concerning some variables between the three cities. Most of the doctors in Şırnak and Hakkari were younger, single, and less experienced compared to the more developed Çanakkale (p<0.05). Discussion: In a hierarchical regression analysis, independent of the other factors, MPAS and MEES were predictors of the total job satisfaction score. MPAS and MEES are the most significant independent variables affecting job satisfaction. Decreasing stressors and assuring a motivating and supportive environment may prove to be helpful in the enhancement of job satisfaction

Changing Trends and Experience with Esophageal Cancer Surgery in a Single University Hospital: Are The Results Similar or Not?

Objective: The main treatment modality for esophageal cancer remains to be surgery. Over the last decades, surgical strategies have evolved remarkably. When neoadjuvant chemoradiotherapy became standard, discussions about the role, type, and timing of surgery began. In this study, we share results we obtained after operating our patients using various surgical techniques.Material and Methods:Reliable data from 51 esophageal cancer patients were evaluated retrospectively. Of the 51 cases, 31 were operable. These operable cases were further classified according to surgical method and neoadjuvant therapy status. Median survival time in months, complications, hospital mortality, length of hospital stay, and pathology results (total lymph nodes harvested and pathologic tumor node metastasis stage [p_TNM]) were documented for the different surgical approaches.Results: Open surgical methods were performed in 21 cases, while in 10 cases the Minimally Invasive Surgery (MIS) method was used. The MIS group received neoadjuvant therapy more frequently than the open surgical methods group (p=0.013). Although more complications were observed in the MIS group, the difference to the open esophagectomy methods group was not significant. Patients in the MIS group also had longer hospital stays, but again the difference was not significant. Although a pathologic complete response was seen in 8 of the 11 (72.7%) patients in our study who received chemoradiotherapy as neoadjuvant treatment, the surgical results of patients who received chemoradiotherapy were worse, although not to a statistically significant extent.Conclusion: Despite changing trends and treatment options in esophageal cancer surgery, we have yet to see the expected improved results

Differentiation and neuro-protective properties of immortalized human tooth germ stem cells

Stem cells are considered to be promising therapeutic options in many neuro-degenerative diseases and injuries to the central nervous system, including brain ischemia and spinal cord trauma. Apart from the gold standard embryonic and mesenchymal origin, human tooth germ stem cells (hTGSCs) have also been shown to enjoy the characteristics of mesenchymal stem cells (MSCs) and the ability to differentiate into adipo-, chondro-, osteo- and neuro-genic cells, suggesting that they might serve as potential alternatives in the cellular therapy of various maladies. Immortalization of stem cells may be useful to avoid senescence of stem cells and to increase their proliferation potential without altering their natural characteristics. This study evaluated the expression of stem cell markers, surface antigens, differentiation capacity, and karyotype of hTGSCs that have been immortalized by human telomerase reverse transcriptase (hTERT) or simian vacuolating virus 40 (SV40) large T antigen. These undying cells were also evaluated for their neuro-protective potential using an in vitro SH-SY5Y neuro-blastoma model treated with hydrogen-peroxide or doxo-rubicin. Although hTGSC-SV40 showed abnormal karyotypes, our results suggest that hTGSC-hTERT preserve their MSC characteristics, differentiation capacity and normal karyotype, and they also possess high proliferation rate and neuro-protective effects even at great passage numbers. These peculiars indicate that hTGSC-hTERT could be used as a viable model for studying adipo-, osteo-, odonto- and neuro-genesis, as well as neuro-protection of MSCs, which may serve as a springboard for potentially utilizing dental waste material in cellular therapy. © 2011 Springer Science+Business Media, LLC

Türkiye’de bulunan yoğun bakımlarda sabun, kağıt havlu ve alkol bazlı el dezenfektanı yeterli mi?: Phokai çalışması sonuçları

Introduction: Hand hygiene is one of the most effective infection control measures to prevent the spread of healthcare-associated infections (HCAI). Water, soap, paper towel and hand disinfectant must be available and adequate in terms of effective hand hygiene. The adequacy of hand hygiene products or keeping water-soap and paper towel is still a problem for many developing countries like Turkey. In this multicenter study, we analyzed the adequacy in number and availability of hand hygiene products.Materials and Methods: This study was performed in all intensive care units (ICUs) of 41 hospitals (27 tertiary-care educational, 10 state and four private hospitals) from 22 cities located in seven geographical regions of Turkey. We analyzed water, soap, paper towel and alcohol-based hand disinfectant adequacy on four different days, two of which were in summer during the vacation time (August, 27th and 31st 2016) and two in autumn (October, 12th and 15th 2016).Results: The total number of ICUs and intensive care beds in 41 participating centers were 214 and 2357, respectively. Overall, there was no soap in 3-11% of sinks and no paper towel in 10-18% of sinks while there was no alcohol-based hand disinfectant in 1-4.7% of hand disinfectant units on the observation days. When we compared the number of sinks with soap and/or paper towel on weekdays vs. weekends, there was no significant difference in summer. However, on autumn weekdays, the number of sinks with soap and paper towel was significantly lower on weekend days (p<0.0001, p<0.0001) while the number of hand disinfectant units with alcohol-based disinfectant was significantly higher (p<0.0001).Conclusion: There should be adequate and accessible hand hygiene materials for effective hand hygiene. In this study, we found that soap and paper towels were inadequate on the observation days in 3-11% and 10-18% of units, respectively. Attention should be paid on soap and paper towel supply at weekends as well