Hydrogen Gas Response of Zn1 – xAgxOy and Cu1 – xZnxOy Nanostructured Films

Detection of hydrogen gas in industry, biomedical systems and combustion systems is important for safety reasons. Silver doping in zinc oxide and zinc doping in copper oxide were investigated to obtain improved hydrogen sensing performances for sensors. Samples were grown by chemical method and studied by X-ray diffraction, SEM and sensorial techniques. For selectivity study samples were exposed to hydrogen, methane and ethanol gases. Were found growth and annealing regimes which allow us fabrication of faster and more selective gas sensors based on Zn1-xAgxOy nanostructured films and nanocrystallite Cu1-xZnxOy films with respect to 100 ppm H2

Ethanol Sensing Performances of Zinc-doped Copper Oxide Nano-crystallite Layers

The synthesis via chemical solutions (aqueous) (SCS) wet route is a low-temperature and cost-effective growth technique of high crystalline quality oxide semiconductors films. Here we report on morphology, chemical composition, structure and ethanol sensing performances of a device prototype based on zincdoped copper oxide nanocrystallite layer. By thermal annealing in electrical furnace for 30 min at temperatures higher than 550 ˚C, as-deposited zinc doped Cu2O samples are converted to tenorite, ZnxCu1-xOy, (x=1.3wt%) that demonstrate higher ethanol response than sensor structures based on samples treated at 450 ˚C. In case of the specimens after post-growth treatment at 650 ˚C was found an ethanol gas response of about 79 % and 91 % to concentrations of 100 ppm and 500 ppm, respectively, at operating temperature of 400 ˚C in air

Causes of unfavorable evolution of pancreatic trauma

Catedra de chirurgie nr. 1 “Nicolae Anestiadi”, Universitatea de Stat de Medicină și Farmacie ”Nicolae Testemițanu”, IMSP Institutul de Medicină Urgentă, Laboratorul Chirurgie Hepato-Pancreato-Biliară, Chișinău, Republica Moldova, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Rezultatele tratamentului chirurgical în traumatismul pancreatic (TP) nu sunt considerate satisfăcătoare din cauza persistenței mortalității cu o frecvență de 13,8-39,4%. Complicația specifică - pancreatita acută posttraumatică (PAPT) se dezvoltă practic după fiecare intervenție chirurgicală cu o frecvența de 25,9-85,7%. Scopul: Analiza cauzelor rezultatelor nefavorabile în tratamentul TP. Material și metode: S-au studiat retrospectiv rezultatele tratamentului chirurgical a 70 pacienți cu TP, și anume complicațiile postoperatorii și letalitatea specifică și nespecifică. Criteriile de includere: vârsta >18 ani și intervenția urgentă; de excludere - decedații 24 ore . Rezultate: În perioada postoperatorie la 48 pacienți au fost depistate complicații specifice, cele mai frecvente fiind pancreonecroza (23 pts), PAPT interstițială și fistulele pancreatice (respectiv câte 11 pts.). Peste 48 ore au decedat 14 pacienți. Letalitatea specifică a constituit 9,6%, nespecifică - 12,4%. În dependență de intervențiile efectuate, complicațiile specifice și letalitatea au fost mai scăzute la drenarea închisă a BO, intervențiile fiind efectuate în gr. I-II de leziune vs gr. III-V (62,2% și 5,3% vs 85,7% și 42,9%). La prezența hemoragiilor s-a stabilit, că suturarea ermetică a țeusuturilor pancreatice a majorat frecvența complicațiilor specifice și letalității vs suturarea neermetică (91,6% și 16,3% vs 60,8% și 9,2%). Administrarea tratamentul medicamentos pentru PAPT, mai ales cu includerea Sandostatinei a diminuat rata complicațiilor și letalității specifice în comparație cu neadministrarea preparatului (56,5% și 4,7% vs 83,2% și 12,3%). Concluzii: Evoluția nefavorabilă a TP este urmare a suturării ermetice a plăgilor, drenării incorecte a BO și omiterii profilaxiei medicamentoase.Background: The outcomes of the surgical treatment in pancreatic trauma (PT) are not considered satisfactory because of the persistence of a high mortality rate, reaching 13,8-39,4%. The specific complication is posttraumatic acute pancreatitis (PTAP) that it develops after each surgical intervention in practice with a frequency between 25,9 and 85,7%. Aim of the study: Analysis of causes unfavorable results (outcomes) in the treatment of pancreatic treatment Methods and materials: The results of surgical treatment were retrospectively evaluated in 70 patients with pancreatic trauma according to (by) postinterventional complications and specific/non-specific lethality. Inclusion criteria were: age greater than 18 years and emergency surgery. Exclusion criteria were: died patients within 48 hours after hospitalization and hospitalization greater than 24 hours. Results: During the postoperative period specific complications were found in 48 patients, the most common being pancreonecrosis in 23 patients, PTAP interstitial and pancreatic fistula in 11 patients, respectively. After 48 hours 14 patients died. Specific lethality was 9.6% and non-specific lethality - 12.4%. Depending on the performed intervention, specific complications and lethality were lowered to the closed drainage of omental bursa (OB), the interventions being made in gr. I-II of lesions vs gr. III-V (62,2% and 5,3% vs 85,7% and 42,9%). In the presence of haemorrhages, it was established that the hermetic suture of pancreatic tissues increased the frequency of specific complications and lethality versus non-ermetic suture (91,6% și 16,3% vs 60,8% și 9,2%). Administration of drug therapy in PTAP, especially with the including of Sandostatin, reduced the rate of complications and specific lethality instead of non-administration of the medicine (56,5% și 4,7% vs 83,2% și 12,3%). Conclusions: The unfavorable evolution of PT is due to ermetic suturing of wounds, incorrect drainage of OB and omission of drug prophylaxis

Hydrogen Gas Response of Zn1 – xAgxOy and Cu1 – xZnxOy Nanostructured Films

Access full text - http://essuir.sumdu.edu.ua/handle/123456789/37150Detection of hydrogen gas in industry, biomedical systems and combustion systems is important for safety reasons. Silver doping in zinc oxide and zinc doping in copper oxide were investigated to obtain improved hydrogen sensing performances for sensors. Samples were grown by chemical method and studied by X-ray diffraction, SEM and sensorial techniques. For selectivity study samples were exposed to hydrogen, methane and ethanol gases. Were found growth and annealing regimes which allow us fabrication of faster and more selective gas sensors based on Zn1 – xAgxOy nanostructured films and nanocrystallite Cu1 – xZnxOy films with respect to 100 ppm H2

Hydrogen Gas Response of Zn1 – xAgxOy and Cu1 – xZnxOy Nanostructured Films

Detection of hydrogen gas in industry, biomedical systems and combustion systems is important for safety reasons. Silver doping in zinc oxide and zinc doping in copper oxide were investigated to obtain improved hydrogen sensing performances for sensors. Samples were grown by chemical method and studied by X-ray diffraction, SEM and sensorial techniques. For selectivity study samples were exposed to hydrogen, methane and ethanol gases. Were found growth and annealing regimes which allow us fabrication of faster and more selective gas sensors based on Zn1-xAgxOy nanostructured films and nanocrystallite Cu1-xZnxOy films with respect to 100 ppm H2

Series and parallel connection of individual Pd-modified ZnO nanowires for gas sensing applications

The hydrogen gas sensing properties of nanodevices based on two ZnO nanowires (NWs) functionalized/modified with palladium (Pd/ZnO) at room temperature are studied. The main goal of the study is to find which of the connections—in series or in parallel—is more favorable to improve the properties of a double NW nanodevice in comparison with a single Pd/ZnO NW-based nanosensor. An enhancement in gas response is observed in both cases. In the case of connection in series of two NWs, it is attributed to an increased number of Schottky barriers, which are directly related to sensor response to gases. In the case of parallel connection of two NWs, higher electrical currents can flow through the device; it improves the sensor response too; in addition, this type of device can be more easily integrated in electronics due to higher currents in passive regime (in air) and is more stable

Individual Bi2O3-Functionalized ZnO Microwire for Hydrogen Gas Detection

Acces full text: https://doi.org/10.1007/978-94-024-1298-7_44Individual micro- and nanostructures of metal oxides are known to be highly sensitive to surface phenomena due to their enhanced surface-to-volume ratio. In this work, an individual Bi2O3-functionalized ZnO microwire (Bi2O3/ZnO MW) with a diameter of ~2.2 μm was integrated into a sensing device using its direct transfer and placement in a focused ion beam (FIB)/scanning electron microscopy (SEM) equipment. The fabricated device was exposed to H2 gas at room temperature showing a detectable response. The gas response to 1000 ppm is ~28%

Gas sensor performances of α-MoO3 belts nanostructured with Pd

Molybdenum trioxide (MoO3) due to its unique physical and chemical properties is one of the most attractive candidates for different promising technological applications]. (MoO3 has a unique morphology that resembles a structure of layered graphene. Due to the layered structure and high chemical stability MoO3 is used for such applications as gas sensors, recording or storage materials, lubricants, electrochromism, and fotochromism. Meanwhile, MoO3 is a promising material for catalysts [4], the field emission, light emitting diode, and energy storage elements, etc., because of its electrical and optical propierties. Nanobelts shaped nanostructures of MoO3 are of major interest due to various gas properties and simple integration technology for bottom-up and the possibility of obtaining cost-effective technologies. Their major drawback is the high surface-to-volume ratio

Nanoheterojoncțiuni din oxid de cupru CuO/Cu2O pentru senzori de gaze explozive și compuși volatili

Resursă ElectronicăNanostructurile de oxid de cupru sunt materiale fascinante datorită proprietăților electrice, optice, termice și senzoriale remarcabile, dat fiind faptul că este posibil stabilizarea fazelor specific în mod unic la dimensiuni nanometrice. În lucrarea dată este prezentată cercetarea heterojoncțiunilor din oxizi semiconductori de dimensiuni nanometrice de CuO/Cu2O cu diferite grosimi la gazul de hidrogen (H2) și vapori de etanol, astfel fiind obținute rezultate experimentale care demonstrează sensibilitatea și selectivitatea nanoheterojoncțiunilor de CuO/Cu2O la vaporii de etanol față de gazul de H2 cu concentrația de 100 ppm. A fost obținut un răspuns de aproximativ 125% la temperatura de operare de 350 º

Acetone sensor structure for biomedical applications

In presents, it is well known that diagnose of human diseases tends to use non-invasive diagnostic methods. They not cause discomfort to patients and the samples are collected rapidly without necessity of special conditions. Thus, different effective methods of real time monitoring and detection of different biomarkers, such as acetone vapour, NOx, NH3, and H2 are highly desirable. Also these method need to be simple in use for all consumers. One of the leading causes of death nowadays according to the World Health Organization is diabetes mellitus, which is also fast-growing problem. Acetone in human breath is known to be the biomarker for clinical diagnosis of diabetes mellitus. It is known that concentration of acetone vapour in exhaled breath of persons diagnosed with diabetes mellitus varies from 1.7 ppm to 3.7 ppm. Detection of such low concentrations requires a high selectivity and sensitivity sensor. In this context, the semiconducting oxides nanostructures of CuO demonstrated promising results