25 research outputs found

    MoS<sub>2</sub> Thin Films for Photo-Voltaic Applications

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    The low dimensional chalcogenide materials with high band gap of ~1.8 eV, specially molybdenum di-sulfide (MoS2), have been brought much attention in the material science community for their usage as semiconducting materials to fabricate low scaled electronic devices with high throughput and reliability, this includes also photovoltaic applications. In this chapter, experimental data for MoS2 material towards developing the next generation of high-efficiency solar cells is presented, which includes fabrication of ~100 nm homogeneous thin film over silicon di-oxide (SiO2) by using radio frequency sputtering at 275 W at high vacuum~10−9 from commercial MoS2 99.9% purity target. The films were studied by means of scanning and transmission electron microscopy with energy disperse spectroscopy, grazing incident low angle x-ray scattering, Raman spectroscopy, atomic force microscopy, atom probe tomography, electrical transport using four-point probe resistivity measurement as well mechanical properties utilizing nano-indentation with continuous stiffness mode (CSM) approach. The experimental results indicate a vertical growth direction at (101)-MoS2 crystallites with stacking values of 7-laminates along the (002)-basal plane; principal Raman vibrations at E12g at 378 cm−1 and A1g at 407 cm−1. The hardness and elastic modulus values of H = 10.5 ± 0.1 GPa and E = 136 ± 2 GPa were estimated by CSM method from 0 to 90 nm of indenter penetration; as well transport measurements from −3.5 V to +3.5 V indicating linear Ohmic behavior

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Multiferroic and Optical Properties of La0.05Li0.85NbO3 and LiNbO3 Nanocrystals

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    The chemistry and physics of surfaces is an increasingly important subject. The study of surfaces is the key of many important nanotechnological applications due to the understanding of phase transitions, electronic structure, and chemical bonding. In later years, exotic phenomena that jointly involve the magnetic and electrical conductivity properties have been discovered in oxides that contain magnetic ions. Moreover, the uses of magnetic oxides in electronic technology have become so important due to the miniaturization of devices and magnetic materials with dielectric properties or vice versa being required for inductors, information storage, thin films for high-density computer memories, microwave antireflection coatings, and permanent magnets for automobile ignitions among others. On the contrary, nanotechnology developments over 10 years or so have provided intensive studies in trying to combine properties such as ferroelectric, ferromagnetic, and optics in one single-phase nanoparticles or in composite thin films; this last effort has been recently known as multiferroic. Because of this, the resurgence of nanomaterials with multiferroic and optical properties is presented in this work of one single phase in lanthanum lithium niobate (La0.05Li0.85NbO3) and lithium niobate (LiNbO3) with ferromagnetic, ferroelectric, relaxor ferroelectricity, second harmonic generation, high-temperature ferromagnetic, and magnetoelectric properties

    Liver function test results predict nutritional status evaluated by arm anthropometric indicators

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    OBJECTIVES: To compare the anthropometric indicators based on weight and height with the anthropometric indicators based on arm measurements and to predict the anthropometric nutritional status with liver function tests (LFTs) in children with chronic liver disease (CLD). PATIENTS AND METHODS: A cross-sectional study in a referral pediatric hospital enrolled 79 children with CLD (mean age 72.6 � 61.8 months, 54% female). An independent variable of LFT was used to determine the outcome variable of nutritional status. Anthropometric indicators of height versus age, weight versus height, head circumference versus age, and arm indicators versus age were analyzed with Pearson correlation, the determination coefficient r, and multiple regression. RESULTS: A total of 44.3% of patients studied had growth impairment. The anthropomorphic indicator of weight for height identified malnutrition in 11.4%, compared with 43% identified by mid- to upper arm circumference (MUAC) and 40.5% identified with total arm area. MUAC (P < 0.001), total arm circumference (P < 0.001), arm muscle area (P = 0.009), and arm fat area (P = 0.023) identified more cases of z score less than -2 SD than weight/height. The presence of ascites misled weight-for-height measurements. Conjugated bilirubin and albumin had significant correlations with almost all of the anthropometric indicators. Alkaline phosphatase correlated significantly with all of the arm anthropometric indicators. A regression analysis led to 7 prediction models; the highest prediction of z score less than -2 SD was with triceps skinfold and conjugated bilirubin, albumin, and ?-glutamyltransferase; height-for-age z score less than -2 SD was predicted by measurements of conjugated bilirubin, prothrombin time, and alanine aminotransferase. CONCLUSIONS: The data presented underline the correlation between the liver damage severity evaluated by LFT and the nutritional status estimated by anthropometric indicators. In our view these observations reflect the close relationship between liver function and the degree of liver damage to growth and current nutritional status. � 2007 Lippincott Williams & Wilkins, Inc

    Structural Aspects LiNbO3 Nanoparticles and Their Ferromagnetic Properties

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    We present a solid-state synthesis of ferromagnetic lithium niobate nanoparticles (LiNbO3) and their corresponding structural aspects. In order to investigate the effect of heat treatments, two batches of samples with a heat-treated (HT) and non-heat-treated (nHT) reduction at 650 °C in 5% of hydrogen/argon were considered to investigate the multiferroic properties and their corresponding structural aspects; using magnetometry and scanning transmission electron microscopy (STEM). Results indicate the existence of ferromagnetic domains with a magnetic moment per unit cell of 5.24 × 10−3 μB; caused mainly due to voids and defects on the nanoparticle surface, as confirmed by STEM measurements
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