Search

Luminescent polymeric graphitic composites have the potential to be efficient energy converters for sophisticated displays and light sources. Thermal condensation is used to synthesize g-C

Luminescent polymeric graphitic composites have the potential to be efficient energy converters for sophisticated displays and light sources. Thermal condensation is used to synthesize g-C 3 N 4 -ZnS composites. The XRD, and FTIR analyses confirmed the synthesis of the pure host, filler, and composites. FESEM, and TEM images revealed that the ZnS nanosheets were evenly distributed over the g-C 3 N 4 sheets. The addition of ZnS improves the thermal stability of g-C 3 N 4 . The optimized gZ15 band gap is determined to be 2.98 eV with a crystallite size of 4.2 nm and a micro stain of 35.42×10 −3 . With a purity of 63.4%, gZ15 demonstrated a significant rate of recombination in the blue region. All of the improved properties demonstrated that polymeric g-C 3 N 4 -ZnS was the optimum materials for usage in the active or emissive layer of optoelectronic devices.

Context: Ventricular septal rupture (VSR) is a dreaded complication following myocardial infarction. Surgical repair of VSR is associated with significant early mortality. Variable outcomes in terms of early mortality and midterm functional status have been reported from different centers. Aims: In our study, we attempt to review the experience of decision making and surgical repair of postinfarction VSR, and to analyze the factors contributing to the early mortality and midterm outcome after repair. Materials and Methods: It is a retrospective study. Data were summarized retrospectively by frequencies and percentages for categorical factors, and means and standard deviations for continuous factors. Multivariate logistic regression, odds ratios, 95% confidence intervals, and P value were calculated for different variables to determine their independent effect on operative mortality. All surviving patients answered the EQ-5D Health Questionnaire. Results: Preoperative renal failure, left ventricular dysfunction (moderate and severe), and Killip class (III and IV) were significantly associated with early mortality after surgery. Small residual ventricular septal defect (VSD) was not found to affect the midterm quality of life. Conclusions: Early surgical repair benefits the patient by preventing early end-organ damage. The renal failure left ventricular dysfunction (moderate and severe) and Killip class (III and IV) adversely affect early outcomes after surgery. Small residual ventricular septal defect (VSD) does not affect the midterm quality of life.

Background Rice is a major cereal crop and staple food of eastern India, and most farmers depend solely on rice for their livelihood. Rice farming provides both tangible and non-tangible benefits to ecosystems which need to be maintained and enhanced. These benefits are provided through ecosystem services (ES) that include both marketable and non-marketable. Methods In this study, the rice farms in eastern India were valued by quantifying the economic value of the services under conventional method of rice cultivation and the gap of ecosystem services value and farm income per unit area were assessed. A stratified random sampling technique was used in this study for selection of agro-climatic zones, districts, blocks, gram panchayat, and study units (households). Soil sampling was also performed for assessing the regulating services (biocontrol of pests, carbon flow, soil erosion, nitrogen fixation), provisioning services (food and by-products), and supporting services (soil fertility, hydrological flow, nutrient cycling, and soil formation). Results The results indicated that the total economic value of ecosystem services ranged from US$ 1238 to 1688 ha−1 year−1. The marketed (primary production) and non-marketed ecosystem services values ranged from 66–89 to 11–34% of the total, respectively. Valuation of some of the ecosystem services such as cultural services, biodiversity, and gas regulation, which may play a significant role in total ecosystem services, has not been made due to non-availability of data and appropriate methodology for rice ecosystem. Different values of parameters can explain the variability in ecosystem services among the agro-climatic zones in eastern India. Clustering of locations based on variability of ecosystem services helps in identifying intervention points for sustaining and improving ecosystem services, while permitting sustainable agro-ecological intensification. The highest total economic gap between ES value and farm income was found in the north central plateau zone (US$ 1063 ha−1 year−1) and the lowest in the north western plateau zone (US$ 670 ha−1 year−1). Conclusion We suggest various measures to reduce the economic gap, including payments for ecosystem services for rice farming for sustainability of the ecosystem and agricultural development, while ensuring reliable farm income.

We report the laboratory synthesis of Poly methyl methacrylate (PMMA)-Zinc sulfide (ZnS) nanocomposite via free radical polymerization method and its structural, optical, electrical, and dielectric properties for various concentration of ZnS nanoparticles. The formation of PMMA, ZnS and PMMA-ZnS nanocomposites was examined by X-ray diffraction technique, Fourier transforms infrared spectroscopy and FT-Raman spectrometer. Morphological structure of PMMA-ZnS nanocomposites showed the combination of pebbled and nanosphere like structure. The in-depth topological images were examined by transmission electron microscopy which indicated that the particles were fairly in good contact. The optimized and reduced band gap was calculated ∼3.30 eV. The photoluminescence spectra showed blue, green and yellow band with increased rate of e−-h+ recombination. The decay time of the PMMA-ZnS (5.0%) nanocomposite was ∼4.8413 ns, and the color purity was calculated ∼ 34.08%. The current density increased ∼249% which indicated the enhancement in conductivity. The dielectric properties of the PMMA-ZnS (5.0%) showed high dielectric constant with a very low dielectric loss. The reduction in optical band gap, high dielectric constant, and increased conductivity with increased in recombination rate confirmed that the as-prepared PMMA-ZnS nanocomposite can be used as an emissive layer in OLED devices.

Many changes have arisen in the world of display technologies as time has passed. In the vast area of display technology, Organic light-emitting diode is a recent and exciting discovery. Organic light-emitting diodes (OLEDs) have received a lot of curiosity among the researcher in recent years as the next generation of lighting and displays due to their numerous advantages, such as superior efficiency, mechanical flexibility and stability, chemical versatility, ease of fabrication, and so on. It works on the theory of electroluminescence, which is a mechanism in which electrical energy converts to light energy. Organic LEDs have a thickness of 100 to 500 nanometers or 200 times that of human hair. In OLEDs, organic material can be used in two or three layers. The emissive layer plays a key role in OLEDs. Polymers are used in the emissive layer to enhance the efficiency of OLEDs at the same time self-luminescence materials are used in OLEDs. In displays, this self-illuminating property removes the need for backlighting. Compared to LEDs and LCDs, OLED displays are smaller, lighter, and more portable.

Even if a ceramic's homogenized properties (such as anisotropically evolving stiffness) truly can be predicted from complete knowledge of sub-continuum morphology (e.g., locations, sizes, shapes, orientations, and roughness of trillions of crystals, dislocations, impurities, pores, inclusions, and/or cracks), the necessary calculations are untenably hypervariate. Non-productive (almost derailing) debates over shortcomings of various first-principles ceramics theories are avoided in this work by discussing numerical coarsening in the context of a pedagogically appealing buckling foundation model that requires only sophomore-level understanding of springs, buckling hinges, dashpots, etc. Bypassing pre-requisites in constitutive modeling, this work aims to help students to understand the difference between damage and plasticity while also gaining experience in Monte-Carlo numerical optimization via scale-bridging that reduces memory and processor burden by orders of magnitude while accurately preserving aleatory (finite-sampling) perturbations that are crucial to accurately predict bifurcations, such as ceramic fragmentation.

Polyaniline-Yttrium Oxide (PANI-Y2O3) nanocomposites were synthesized via chemically oxidative polymerization process. The formation of PANI, and PANI-Y2O3 nanocomposites with their corresponding changes in nanostructured properties were examined by Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction Spectroscopy (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The UV-Vis analysis exhibited PANI-Y2O3 nanocomposite possess lower band gap and higher absorption intensity than pristine PANI. The PL spectra of PANI and PANI-Y2O3 nanocomposite reveals four bands as violet, blue, green and orange bands due to non-radiative recombination of electron-hole pair. The electrical properties for PANI-Y2O3 nanocomposite showed 78 % enhancement in current density. The PANI-Y2O3 nanocomposite exhibited enhanced carrier density and excellent rate of electron-hole recombination that proposed to be suitable candidate for electron transport layer in OLED devices.

The integration of semi-conductive materials into the polypyrrole (PPy) matrix tends to be an effective way to improve PPy's properties. Herein we report the laboratory synthesis of rGO-PPy-ZnS (rPZ) nanocomposites through in-situ oxidative polymerization processes. The structural and morphological verification of nanocomposites was carried out by XRD, FESEM and TEM. At the dominant wavelength, the Photoluminescence spectra display cyan color with a high rate of e − -h + recombination. The decrease in band gap (1.48 eV) and refractive index (2.52) of rPZ showing surface conductivity. The CCT and Duv value shows the light level above the black body curve and the color purity is 55.5 % . The current density has increased by 115 % , indicating an increase in conductivity. The decrease in the optical band gap, and improved conductivity with increased recombination frequency verified that the as-prepared rGO-PPy-ZnS (rPZ) nanocomposite can be used in OLED devices as an emissive layer.

The PPY, PANI and PPY-PANI-ZnO nanocomposite were prepared via chemical oxidative polymerization method using ammonium persulfate as oxidant in the laboratory. The successful embodiment of ZnO in the surface of PPY-PANI was confirmed by Fourier transform inferred spectroscopy (FTIR) analysis. The nano-flakes of ZnO were completely covered by PPY-PANI fibrous spherical ball like structure as studied by the surface morphological images. An enhanced current density ∼164.81 % and high non-radiative recombination of electron-hole was observed with significantly enhanced conductivity for 15 % PPY-PANI-ZnO nanocomposite. The high dielectric constant (∼ 895) at 333 K with high electrochemical reduction potential (∼ +0.650 V) and high electron-hole recombination rate specified that it can used as electron transporting layer material for OLED devices.

Pristine PMMA and PMMA-ZnS nanocomposites were synthesized via free radical polymerization process. The formation of the PMMA matrix and its nanocomposite were confirmed by X-ray diffraction technique (XRD) analysis. The FESEM and TEM image of PMMA-ZnS nanocompositeshowed the mixture of pebbled and spherical ball like structure. Increase rate of electron-hole recombination of PMMA-ZnS nanocomposite was studied from PL spectra. The PL spectra of nanocomposite showed four bands attribute to the blue-violet band, blue band, green band and yellow band. The color coordinate of PMMA-ZnS nanocomposite was found to be in the blue region. The electrical properties showed the good conductive response in PMMA-ZnS nanocomposite. These optical and electrical properties confirmed that the proposed PMMA-ZnS nanocomposite can be used for OLED application as emissive layer.

This paper reports design, fabrication, and gait planning based on high walk diagonal trot gait pattern of an alligatorinspired robot having eight degrees of freedom. Each leg of the robot described in this paper has two revolute joints representing the hip and knee respectively which are actuated by servo motors. The body of the robot was fabricated on a CO2 laser cutting machine. The 3D leg design was dividedinto two 2D components to enable manufacturing on a laser cutting machine to reduce fabrication cycle time. Finally, a general-purpose kinematics based model has been reported that is used to designand implement a high-walk gait on the developed robot.

Bedsore is a global problem concerning the bedridden, infirm, debilitated and malnourished patients in hospitals and community setups. The cost of treatment is enormous involving billions of dollars to nations and individuals. Mortality increases two to six times if bedsores are present. There is little research done despite its commonness to understand how they occur or why they occur; etiology is not much understood. The two theories called ‘top to bottom’ and ‘bottom to top’ contradict each other. It is thought that ‘pressure’, shear-stress’ and ‘ischemia’ may be causing it in some yet to be understood way. There is little awareness on how to prevent them or how to treat them if they do occur. Seldom applied, various scales exist and should be used to identify patients at high risk. Braden scale is the most tested and widely accepted scale. The various available dressings and pressure relief devices are mostly inadequately studied; which is superior is a question that begs an answer. This article aims to underline the importance of bedsores by reviewing our current and past knowledge with emphasis on practical implications thereof.

Intussusception is a common cause of acute intestinal obstruction with potentially serious complications. The treatment of choice is an attempt at initial non-operative treatment.The purpose of the study was to evaluate the efficacy of the technique of hydrostatic reduction of intussusception using saline enema and ultrasound being practiced in our institute; the secondary goal was to identify patient subset in which it is more successful.The case records of all patients treated for intussusception in our institute from 1st January 2000 to 30th June 2007 were retrospectively analyzed to collect information. All patients with ultrasound diagnosed intussusception that were not having signs of shock or peritonitis were treated with normal saline enema under ultrasound guidance. Failure of three such attempts was an indication for operation.We found that this technique is easy, safe and extremely effective in treating intussusception in children. The success rate was 81.37% (83 out of 102 cases) and mortality rate was 1.2%. Ileoileocolic type of intussusception failed enema reduction more often (statistically significant; P value = 0.0032) while older patients (statistically significant, P value = 0.001) had higher success rates with the technique. Patients who had colocolic type of intussusception (P value = 0.29) and patients who present early (P value = 0.262) appear to have higher success rates but this was not statistically significant.

ULTIPLE MYELOMA (MM) represents a malignantproliferation of plasma cells derived from a single clone.MM accounts for 13% of all hematologic malignancies inwhites and 33% in blacks. The incidence of myeloma is 1 to 9per 100,000, worldwide with a higher incidence in NorthAmerica (7.1 per 100,000 population for men and 4.6 per100,000 for women) and lower in Asia (China, Japan andIndia).

Brachial arterial aneurysm is a rare entity. We present a case of multiple serial aneurysms of the brachial artery with associated multiple arteriovenous malformations of the forearm, along with symptoms of distal ischemia and its surgical management.

Diabetic foot ulcer (DFU) is the leading cause of lower extremity amputation and is generally known to have poor prognosis. Oxidative stress is considered important in the pathogenesis of chronic wounds. Fibrinogen is a recognized marker in peripheral vascular disease; increasing levels predict an increased mortality and risk of amputation. The aim of this study was to evaluate if plasma malondialdehyde (MDA), protein carbonyl (PC) and fibrinogen levels can be used as prognostic markers in patients with DFU. The study design was prospective, nonrandomized, and controlled. A total of 41 DFU grade 1 and 20 DFU grade 2 patients were studied in this case—control study. Diabetic controls without foot ulcers and healthy controls were also studied. Plasma MDA, PC, and fibrinogen levels were significantly higher in patients with DFU compared with those without ulcers ( P < .05) and nondiabetic controls ( P < .001). These parameters increased in association with DFU grade ( P < .01). Increased levels of plasma fibrinogen, MDA, and PC correlated with worsened outcomes. An augmented oxidative stress and plasma fibrinogen level >300.4 mg% (95% confidence interval, 100% sensitivity, 99.2% specificity) was correlated with a high risk of amputation in DFU.

Nous presentons un cas d’anevrysmes multiples de l’artere brachiale associes a des malformations arterioveineuses multiples de l’avant-bras, avec des symptomes d’ischemie distale et leur traitement chirurgical.