Characteristics of the copper vapor thermionic vacuum arc discharge

Saf metal buharlarında bir deşarjın oluşturulması ve çalışılması, metal atomlarının uygun buhar basıncını elde etmek için gerekli sıcaklığın yüksek olması nedeniyle zor bir problemdir. Termiyonik vakum ark (TVA) deşarj, doğrudan ısıtılan termiyonik katotlar kullanarak anotun buharlaşmasıyla oluşan yeni tip bir deşarjdır. Saf metal buharlarındaki bu deşarj, herhangi tür metal buharlarında ve ayrıca erimeyen metallerin buharlarında da oluşturulabilmektedir. TVA deşarj, yönlendirilmiş enerjili iyonlar içeren saf, gaz karışımı bulunmayan metal buharı plazması üretmektedir. TVA deşarjların gözlenen akım voltaj karakteristikleri, termiyonik katotun sıcaklığına, buharlaştırılan anot materyalinin cinsine ve elektrotların birbirine göre konumuna bağlıdır. Anahtar Kelimeler: Bakır, metal buharları, termiyonik katot, vakum ark deşarj.The production and study of a discharge in pure metal vapors is a diffucult problem due to the high temperature needed to obtain a convenient vapor pressure of the metal atoms. The thermionic vacuum arc(TVA) discharge is a new type of discharge with evaporating anodes employing directly heated thermionic cathodes. This discharge in pure metal vapors can be ignited in any kind of metal vapors including refractory metals too. The TVA discharge generates a pure, gas-free metal vapor plasma containing ions with a directed energy. The discharge is produced in vacuum between a heated cathode and an anode. The electrons emitted from the cathode are accelerated toward the anode by the applied voltage accross the electrodes, the flux of electrons being concentrated on a small area of the anode surface which becomes a melted metal spot. At a further increase of the applied voltage, an intense discharge is established in the metal vapors, evaporated from the anode. Because of the high power density incident on the anode surface, especially after arc ignition, high evaporation rate of the anode material is observed. The observed volt-ampere characteristics of the TVA discharges depend strongly on the temperature of the thermionic cathode, the evaporated anode material and the relative position of the electrodes. Keywords: Copper, metal vapors, thermionic cathode, vacuum arc discharge

Cold Plasma Technology: Bactericidal Effects on Geobacillus Stearothermophilus and Bacillus Cereus Microorganisms

Introduction: Cold plasma, also known as Low Temperature Atmospheric Pressure Plasma (LTAPP) is a novel technology consisting of neutral and charged particles, including free radicals, which can be used to destroy or inactivate microorganisms. Research has been conducted regarding the effect of cold plasma on gram-positive bacteria; however, there is limited research regarding its ability to inactivate the spore-formers Geobacillus stearothermophilus and Bacillus cereus. Purpose: The purpose of this study was to determine if cold plasma inactivates G. stearothermophilus and B. cereus vegetative cells and spores. Methods: Nine hundred eighty-one samples were included in this study (762 experimental and 219 controls). Experimental samples were exposed indirectly or directly to cold plasma, before plating and incubating for 16 hours. Control samples were not exposed to cold plasma. The percentage-kill and cell number reductions were calculated from Colony Forming Units (CFU). Data were statistically analyzed at the .05 level using one-way ANOVA, Kruskal Wallis and Tukey\u27s tests. Results: There was a statistically significant difference in the inactivation of G. stearothermophilus vegetative cells receiving indirect and direct exposure (p=0.0001 and p=0.0013, respectively), as well as for B. cereus vegetative cells and spores (p=0.0001 for direct and indirect). There was no statistically significant difference in the inactivation of G. stearothermophilus spores receiving indirect exposure (p=0.7208) or direct exposure (p=0.0835). Conclusion: Results demonstrate that cold plasma exposure effectively kills G. stearothermophilus vegetative cells and B. cereus vegetative cells and spores; however, G. stearothermophilus spores were not significantly inactivated

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Application of Stockwell Coherence To Prediction Of Alertness Under Anaesthesia

In this paper, we represent an application of Stockwell Coherence to scalp EEG signals under anesthesia. By the analysis of overlapping, stationary data segments, we obtained the time-varying Stockwell coherence, which reveals the time evolution of coherence changes between any selected channel pair. After the injection and release of the anesthetic agent, time-varying Stockwell coherence analyses demonstrate similar characteristics for different patients

Investigation Of Surface Polarization Charges In He Gas Discharges

Elektrik yükleri, elektriksel gaz deşarj cihazlarının dielektrik materyalleri üzerinde depolanabilir. Elektriksel gaz deşarj cihazının dielektrik materyalleri üzerinde depolanan yükler, cihazın potansiyel dağılımını ve ateşlenme koşulunu değiştirir. Bu çalışmada, dielektrik yüzeyler üzerine yük depolanmasını incelemek için, dielektrik yüzey polarizasyonunun yapılabildiği bir deşarj cihazı kullanıldı. Deşarj cihazının dielektrik çeperleri üzerine depolanmış yüklerin ölçümü olarak, ateşlenme voltajı değerleri ölçüldü ve polarizasyon potansiyelinin ateşlenme voltajı değerlerine güçlü etkisi ispatlandı

Individual-based Estimation of Valence with EEG

2020 Medical Technologies Congress (TIPTEKNO) -- NOV 19-20, 2020 -- ELECTR NETWORK -- Biyomedikal ve Klinik Muhendisligi Dernegi, Izmir Ekonomi Univ, Izmir Katip Celebi UnivIn this study, it is determined individual-based features which are used to estimate emotional negative valence and compared the features effectiveness with different classifiers. Ten movie clips are shown to subjects as an emotional stimuli and EEG recording is recorded synchronously. Emotional valence value is scored in [-7 7] Likert scale by the subjects immediately after video ended. According to lowest and highest valence values, two classes are generated. The data is processed on an individual basis and personal spatial filters is obtained by Independent Component Analysis. After calculating the spectrogram of the spatial filtered data, features are extracted by subtracting amplitudes of 3Hz averaged frequency bands. The result of feature selection, it is observed that features from beta and gamma bands are much more effective. The success rate of the selected features was tested with five classifiers by cross validation, and high performance was obtained from multilayer perceptron classifiers and the instance-based k-nearest neighborhood algorithm (IBk-NN). The average accuracies of IBk-NN and multilayer classifier are achieved 86% +/- 8 and 83% +/- 9, respectively.WOS:0006594199000312-s2.0-8509947322

Antibacterial efficiency of cadmium thin films deposited by the thermionic vacuum arc

In this study, thin films of the pure Cadmium (Cd) were deposited on glass and high-density polyethylene (HDPE) samples by the Thermionic Vacuum Arc (TVA) method. The structural and surface morphological properties of Cd thin-films were investigated using X-ray diffraction patterns (XRD), field emission scanning electron micro-scope (FE-SEM), and atomic force electron microscope (AFM). The water contact angle (WCA) was determined by a Kruss DSA100 model goniometer. The antibacterial activities of the Cd-coated and uncoated samples were investigated by direct-contact test and modified Kirby-Bauer test against Escherichia coli O157:H7 ATCC35150, Staphylococcus aureus ATCC6538P and Listeria innocua ATCC33090. Cd thin films deposited on both samples were found to be in crystalline form. The Crystallite size of the films deposited on glass and HDPE were calculated as 52.1 and 72.5 nm, respectively. The SEM and AFM depict the Cd films uniform distribution of grains. The root mean square (Rms) surface roughness of Cd thin film was found as 39.3 nm and 70.3 nm on glass and HDPE substrates, respectively. The WCA measurements showed the cadmium coatings increased the hydrophobicity of glass and HDPE samples. Direct-contact test showed both Cd-coated samples totally inhibited E. coli O157:H7 and L. innocua strains after 2-h of contact time. Modified Kirby-Bauer test indicated the Cd-coated HDPE samples showed the highest antibacterial activity against L. innocua however Cd films did not have any antibacterial activity for both samples against S. aureus.The authors would like to thank Assoc. Prof. Yilmaz YUEREKLI for his technical support on water contact angle analysis by Kruess DSA100 model goniometer. Cagri Durmus, is supported by YOK (Council of Higher Education) 100/2000 Ph.D. Scholarship Program.YOK (Council of Higher Education