Polyvinylidene fluoride (PVDF)‐functionalized single walled carbon nanotube (FSWCNT) film composites were prepared by two different process conditions—air drying and vacuum drying. Though reports on ...–PVDF‐FSWCNT composites are available, we provide a new outlook here, which is based on optimized functionalization and novel processing conditions. The microstructural and phase changes occurring in PVDF having nanotubes functionalized for different extent of time were investigated and confirmed that those functionalized for 4 h (FSWCNAT‐4) create polar γ phase in PVDF with improved mechanical and electrical properties. X‐ray photoelectron spectroscopy studies showed that PVDF/FSWCNT‐4 composites have the maximum percentage of functional groups. It is also found that PVDF/FSWCNT‐4 composite films prepared through air drying were rough and had a cloudy appearance suitable for applications demanding open porous structures, whereas those prepared through vacuum drying process were smooth and homogeneous with high optical transparency, suitable for microelectronic applications. Thus, by suitably controlling the processing conditions and by using optimally functionalized nanotubes, PVDF films with multifunctional properties could be achieved. In order to extract the full capabilities of PVDF/SWCNT films, functionalization of the nanotube together with processing conditions plays a significant role.
•Both the hospital and the coordinating organisation benefit if the later commits to effort upfront.•Cost-sharing leads to a greater payoff for the supply chain players.•Threat of penalty induces the ...hospital to join the authorised channel at a lower fee.•The hospital must focus on the marginal effectiveness of its own efforts and combined benefits.
The low rate of cadaveric organ donation is a challenge that most countries struggle with. In this study, we examine factors and alternate decision-making setups that influence the supply of cadaveric organs, and identify possible incentives and mechanisms to increase it. We develop a model that captures the interaction between supply-side entities – a coordinating organisation, whose objective is to maximise the social welfare, and a hospital that performs the organ retrieval. Under different setups, we evaluate the two levers available to the coordinating organisation, its own effort and reimbursement fees, which can be used to induce higher effort by hospitals. We contrast these decisions and payoffs to determine if any benefits are forthcoming from the coordinating organisation’s effort commitment. We also examine the hospital’s optimal channel decision in the presence of an unauthorised channel and a low paying authorised channel, and derive the conditions under which the hospital would prefer the authorised channel over the unauthorised channel. Our results provide insights that lead to better outcomes for the players, and result in the improved organ donation rate.
The complement system plays a crucial role in retinal homeostasis. While the proteomic analysis of ocular tissues in diabetic retinopathy (DR) has shown the deposition of complement proteins, their ...exact role in the pathogenesis of DR is yet unclear. We performed a detailed investigation of the role of the complement system by evaluating the levels of major complement proteins including C3, C1q, C4b, Complement Factor B (CFB), and Complement Factor H (CFH) and their activated fragments from both the classical and alternative pathways in vitreous humor and serum samples from proliferative DR (PDR) patients and controls. Further, the expressions of complements and several other key pro- and anti-angiogenic genes in the serum and vitreous humor were analyzed in the blood samples of PDR and non-PDR (NPDR) patients along with controls without diabetes. We also assessed the pro-inflammatory cytokines and matrix metalloproteinases in the vitreous humor samples. There was a significant increase in C3 and its activated fragment C3bα' (110 kDa) along with a corresponding upregulation of CFH in the vitreous of PDR patients, which confirmed the increased activation of the alternative complement pathway in PDR. Likewise, a significant upregulation of angiogenic genes and downregulation of anti-angiogenic genes was seen in PDR and NPDR cases. Increased MMP9 activity and upregulation of inflammatory markers IL8 and sPECAM with a downregulation of anti-inflammatory marker IL-10 in PDR vitreous indicated the possible involvement of microglia in DR pathogenesis. Further, a significantly high C3 deposition in the capillary wall along with thickening of basement membranes and co-localization of CFH expression with CD11b
activated microglial cells in diabetic retina suggested microglia as a source of CFH in diabetic retina. The increased CFH levels could be a feedback mechanism for arresting excessive complement activation in DR eyes. A gradual increase of
and
expression in retina with early to late changes in epiretinal membranes of DR patients indicated a major role for the alternative complement pathway in disease progression.
Lithium silicates are ceramic materials known for its high CO
2
adsorption capacity and excellent cyclic stability at high temperatures. In the present work, an attempt has been made to use different ...types of organosilicone precursors viz., methyltrimethoxysilane, triethoxyphenylsilane, polyoligomericsilsesquioxane and polydimethylsiloxane as the silica precursor for the synthesis of lithium silicates for CO
2
adsorption. Thermogravimetry and differential scanning calorimetry were used to optimize the thermal decomposition of precursor to lithium silicate. Polydimethylsiloxane could not produce lithium silicate, as it decomposed to form volatile cyclic silicon oligomers at high temperatures. Lithium silicates were obtained from the other three precursors and were characterized for its structure and morphological features using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron micrography, energy-dispersive X-ray spectrometry, particle size and surface area analysers. The CO
2
adsorption/desorption studies using thermogravimetry showed that lithium silicates synthesized from the silica precursor, methyltrimethoxysilane, retained a cyclic adsorption capacity of 31% for 10 cycles. The study reveals that hydrolysable aliphatic organosilicone compounds are better silica precursors for the synthesis of lithium silicates for regenerable CO
2
sorption.
To evaluate the anatomical and visual outcomes of inverted flap technique of peeling of internal limiting membrane (ILM) versus standard peeling of ILM for macular holes of basal diameter more than ...800 μm.
Patients with very large idiopathic macular holes more than 800 μm in basal diameter (ranging from 243 μm to 840 μm in minimum diameter) were retrospectively included in the study. In Group A, 18 eyes of 18 patients underwent ILM peeling using the inverted flap technique. In Group B, 18 eyes of 18 patients underwent conventional ILM peeling. The primary endpoint was the rate of hole closure at 6 months after surgery. The secondary outcome measure was the change in best-corrected visual acuity at 6 months after surgery.
There were no significant differences in ocular characteristics of the study groups at baseline except for the age distribution. Mean macular hole diameter was 1,162.8 ± 206.0 μm and 1,229.6 ± 228.1 μm in Group A and Group B, respectively. The hole closure rate was 88.9% (16/18) in Group A and 77.8% (14/18) in Group B (P = 0.66). The mean gain in best-corrected visual acuity was higher in Group A than in Group B (P = 0.12) at 6 months, but this was not statistically significant. There were no severe ocular adverse events in either group.
In this multicenter series, inverted ILM flap technique did not lead to significantly higher anatomical closure rates than conventional ILM peeling in large macular holes more than 800 μm in diameter.
Unfunctionalized few layer graphene (FLG) nanoplatelets were mixed with acrylonitrile butadiene rubber (NBR) by melt mixing and the properties were compared with composites containing carbon black ...alone and a 1:1 mixture of FLG and carbon black. Incorporation of a very small amount of FLG significantly improved the cure characteristics of NBR. Compared to graphene, similar loading of carbon black gave higher rheometer torque at the expense of scorch safety whereas hybrid filler gave optimum cure characteristics. There was more than 190% improvement in tensile strength when 5 phr FLG was added to the matrix. On the other hand, to achieve the same strength, five times more of carbon black was needed compared to FLG. In contrast to carbon black, FLG increased the compression set of the rubber. The compositions containing 1:1 mixture of the fillers displayed compression set values in between those containing FLG or carbon black alone. The storage modulus was also found to be optimum for the composites containing equal amounts of FLG and carbon black. FLG loaded composites displayed significant reduction in the creep compliance. Additionally, the helium leak rate of the composites was decreased in presence of FLG due to its platelet structure.
This paper describes the development of toroid-based seawater conductivity sensors and instrumentation for 0 to 60 mS/cm conductivity range and 50 bar hydrostatic pressure operational capability ...which is equivalent to 500 metres of ocean depth. Double core toroidal transformer concept was used and investigated for Mn-Zn and Fe based nanocrystalline cores, turns ratio and temperature dependence. Different excitation and sense coil turn numbers were fabricated by keeping the turn's ratio 1:2, 1:4, 1:6 and 1:8. Optimum frequency of Mn-Zn based conductivity sensors with lower and higher turn numbers were observed for turn ratio 1:8 and 1:4 respectively at 120 kHz and obtained voltage responses of 952 and 1567 mV. Fe based Nano crystalline core with turn ratio 1:8 shows an optimum frequency of 70 kHz and giving a voltage difference of 830 mV. Two dimensional polynomials of order 2 were presented for temperature dependence of conductivity for Mn-Zn core based sensors. Sensor responses of Fe based nanocrystalline core sensors in 'lower turn number' configuration with same turn ratio is presented and observed linear temperature dependence compared to Mn-Zn based sensors. The mechanical design and frequency of operation of developed conductivity sensors gives inherent immunity to ASW band of frequency interference. The efficacy of conductivity sensor with measuring electronics and commercial standard sensors profiling was proved experimentally compared up to 500 metres in sea profiling and obtained a root mean square error of 0.42 for profile data.
•Perchlorate removal efficiency evaluated for a packed bed column using granular activated carbon modified with HCl.•Adsorption behavior studied using Thomas, Yoon-Nelson and Adam-Bohart ...models.•First order kinetics followed, tends towards second order as initial concentration and flow rate increased.•The chemical regeneration using HCl most effective than thermal method with good efficiency, yield and processability.
The adsorption performance of packed bed column using coconut shell based activated carbon for the removal of perchlorate from water was investigated. The influence of parameters like inlet ion concentration, flow rate and bed height on the breakthrough curves and adsorption performance were studied. The results indicated that the adsorption efficiency increased with increase in the initial concentration and the bed height, decreased with increase in the flow rate which in turn resulted in a shorter saturation time. It also revealed that the throughput volume of the aqueous solution increased with increase in bed height owing to the availability of more adsorption sites. The adsorption kinetics was analysed using three kinetic models viz. Adam- Bohart, Thomas and Yoon-Nelson models. The maximum adsorption capacity increased with increase in flow rate and initial ion concentration but decreased with increase in bed height. The perchlorate uptake data was also analyzed for first and second order kinetics. The regeneration of spent activated carbon was systematically investigated by thermal and chemical regeneration methods under different operating conditions.
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•Facile all-solution growth of nanostructured p-CuO and n-ZnO TSO films is reported.•Annealing the films in air affects the structural, electrical and optical properties.•p-n ...heterojunction using these films was fabricated in ITO/n-ZnO/p-CuO/Au structure.•Transparent heterojunction diode performed well with a Von of 2.5V and n of 3.15.•Fabricated p-CuO/n-ZnO heterojunction diode can be used for UV detector application.
We report a facile all-solution approach for the growth of nanostructured p-CuO and n-ZnO thin films. The influence of annealing temperature on the physical properties of CuO and ZnO thin films was examined. XRD and Raman spectra depict the structural and phase purity of solution grown CuO and ZnO films. The electrical as well as the optical properties of thin films were also studied. The average optical transmission of CuO and ZnO thin films in the visible spectral region was found to be above 80 and 95% respectively. Band gap energy variations on annealing temperature were investigated for CuO as well as ZnO films. Surface morphology analyzed by FESEM shows that the films are very smooth. All solution grown p-n heterojunction using p-CuO and n-ZnO films was fabricated in the structure ITO/n-ZnO/p-CuO/Au which showed rectification behavior with a turn on voltage of 2.5V and an ideality factor of 3.15.
Nitrogen-enriched carbon with well-developed microporosity and superior CO2 adsorption capacity was prepared by KOH activation of a nitrogen-containing polymer obtained by heating sucrose and urea. ...The nitrogen content, microporosity, and surface area of the activated carbon depend on the concentration of urea and KOH. The maximum surface area, total pore volume, and nitrogen content of the activated carbon produced were 2366 m2/g, 1.16 cm3/g, and 10.5 wt%, respectively. A maximum CO2 adsorption capacity of 7.0 mmol/g was achieved at 0 °C and 1 bar. The CO2 adsorption capacity of 0.70 mmol/g from dry air containing 400 ppm of CO2 was the highest reported in the category of carbonaceous materials. The CO2 adsorption capacity of all the prepared carbon materials correlated well with the nitrogen content and microporosity. CO2 adsorption on the activated carbon materials showed excellent selectivity over nitrogen, with one of the highest selectivity factors of 38; hence, it is an ideal candidate for CO2 removal from flue gases.
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