Influence of osmolytes on the stability of thylakoid‐based dye‐sensitized solar cells

In recent years, there has been considerable interest in incorporating naturally occurring components of the photosynthetic apparatus into man‐made solar cells, because of the high quantum efficiency of photosynthetic reaction centers. One hurdle to overcome regarding the use of native membranes in these devices is their limited lifespans. In this study, we used stabilizers to increase the long‐term viability of biomolecules in vitro, thereby alleviating this challenge. In this regard, it is known that osmolytes, such as glycine betaine (GB) and sucrose, preserve photosynthetic activity in isolated photosystems. Upon investigation of the thermal protection properties of GB and sucrose in thylakoid‐based dye‐sensitized solar cells, we report that the addition of GB and sucrose to the thylakoid photosensitizer maintains nonzero photocurrent in the thylakoid‐based solar cell upon heating to 50°C. At 50°C, the GB‐containing cell displayed about a fourfold increase in photocurrent than the control cell, in which the photocurrent was decreased to nearly zero. The addition of 0.5M and 1M sucrose has respectively caused nearly 40% and 70% increases in photoinduced electron transfer activity over the control at 35°С. Similarly, though to a lesser extent, 1M GB caused an approximate 40% increase in electron transfer activity as well. Moving forward, this approach will be extended to alternative membrane protein isolation strategies, allowing for an accurate comparison with traditional detergent‐isolated complexes, with the ultimate goal of developing a cost‐effective and sustainable solar cell.     

Neural network-supported patient-adaptive fall prevention system

Neural Computing and Applications - Patient falls due to unattended bed-exits are costly to patients, healthcare personnel and hospitals. Numerous researches based on up to three predetermined...     

Correction to: Novel authorship verification model for social media accounts compromised by a human

Multimedia Tools and Applications - A Correction to this paper has been published: https://doi.org/10.1007/s11042-021-10617-5     

Poly(2‐hydroxyethyl methacrylate)/boric acid composite hydrogel as soft contact lens material: Thermal,optical, rheological,and enhanced antibacterial properties

The present work proposes to fabricate a composite hydrogel material that well characterized, transparent, biocompatible, and self‐antibacterial as potential soft contact lens material. For this purpose, poly(2‐hydroxyethyl methacrylate) (PHEMA)/boric acid (BA) composite hydrogels were successfully prepared by chemical crosslinking with BA through in situ polymerization using different BA ratios between 1 and 10% w/w. Afterward, the compositions, thermal stability, transparence, oxygen permeability, water uptake capacity, swelling ratio as well as morphological and rheological properties, in vitro degradability, in vitro cytotoxicity, and antibacterial properties of the all prepared materials were analyzed using a series of different techniques. The thermal stability, hydrophilicity, water uptake, oxygen permeability gradually increased depending ratio of BA, which is desirable for biomaterial. While the transparence and refractive index decreased, the composite hydrogels, except for BA content of 10 wt %, maintained enough transparency to be used for contact lens. In addition, PHEMA/BA composite hydrogels exhibited good cytocompatibility (PHEMA‐1%BA and PHEMA‐3%BA) and excellent antibacterial activity against Gram‐positive (Staphylococcus aureus and Enterococcus faecium) and Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. Overall, the results demonstrated that the obtained PHEMA/BA composite hydrogels could be considered as self‐antibacterial contact lens and a potential composite biomaterial for other applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46575.     

Effects of flexible plate attached to the rear of the cylinder on flow structure

In this experimental study, the flow structure in the wake flow region was investigated with the Particle image velocimetry technique (PIV) by attaching elastic plates at different lengths behind the cylinder. The flow structure occurred at the wake flow region altered depending on the length of the flexible matter. In this experiment, the strips with the lengths of 75, 90, 120, 135 and 180 mm were used to control instabilities. Diameter of the cylinder (D) is 60 mm and the water height (h _w ) is 600 mm. Reynolds number was kept constant as 5000 based on cylinder diameter. The images were captured at mid-height of the cylinder (h _m ) which is 250 mm. As a result of experimental studies, attached flexible strip suppressed vortex shedding occurred in the behind of the cylinder and it is observed that effect of the length flexible of the strip is pretty much. Maximum level of flow characteristics such as Reynolds stress, fluctuation velocities and turbulent kinetic energy were decreased with flexible splitter plate and shifted through the downstream region.     

Bench Scale Studies for Pretreatment of Sanitary Landfill Leachate with Moringa Oleifera Seeds Extract

A laboratory study using a bench scale model of two unit operations involved processes of coagulation (using Moringa oleifera seeds as a natural coagulant) and flocculation-sedimentation have been adopted to treat the leachate from Air Hitam Sanitary Landfill at Puchong in Malaysia. The results of this study has shown, that M. oleifera has a potential for the removal of heavy metals from the leachate, and may be used as a pre-treatment stage for biological treatment to eliminate a portion of the toxic heavy metals, which limit the activity of micro-organisms in the leachate.     

Floc settling characteristics of turbid water coagulated with moringa oleifera seeds

The results of studies into the particle aggregations and settling rates of flocs from turbid water (kaolin suspension) with turbidities varying from 50 to 550 NTU coagulated with Moringa oleifera seeds are presented. The results of the laboratory based study showed that the maximum value of the “apparent aggregation rate”, K _app,increased with increase in initial turbidity. K _app was found to be 0.000778 for low turbidity (50 NTU) and 0.00654 for high turbidity (550 NTU). The velocity gradient for rapid mix at the maximum K _app was found to be constant at 443/sec for all turbidities. Settling rate of floc coagulated with Moringa oleifera seed was dependent on the initial turbidity of the water sample. For water with initial turbidity of 50 NTU, 30% to 70% turbidity was removed between 60 and 210 minutes, while for high turbidity of 400 to 550 NTU, 80% to 95% turbidity removal occurred between 60 and 150 minutes.     

pH‐ and temperature‐induced release of doxorubicin from multilayers of poly(2‐isopropyl‐2‐oxazoline) and tannic acid

We present a simple strategy to prepare doxorubicin (DOX) containing hydrogen‐bonded films of poly(2‐isopropyl‐2‐oxazoline) (PIPOX) and tannic acid (TA) which release DOX in acidic conditions while releasing a minimal amount of DOX at physiological pH. Water soluble complexes of TA and DOX (TA ? DOX) were prepared prior to film construction. PIPOX and TA ? DOX were deposited at the surface at pH 6.5 using the layer‐by‐layer (LbL) technique. We found that multilayers released a minimal amount of DOX at physiological pH due to further ionization of TA with increasing pH and enhanced electrostatic interactions between TA and DOX. In contrast, pH‐induced release of DOX was observed in moderately acidic conditions due to protonation of TA as the acidity increased and electrostatic interactions between TA and DOX decreased. Moreover, we found that raising the temperature from 25 °C to 37.5 °C increased the amount of DOX released from the surface. This can be rationalized with the conformational changes within the multilayers correlated with the lower critical solution temperature behaviour of PIPOX and increased kinetic energy of DOX molecules. Considering the acidic nature of tumour tissues and important biological properties of PIPOX and TA, these multilayers are promising for pH‐ and temperature‐triggered release of DOX from surfaces. © 2017 Society of Chemical Industry     

Energy efficiency in pumps

In this paper, “energy efficiency” studies, done in a big industrial facility’s pumps, are reported. For this purpose; the flow rate, pressure and temperature have been measured for each pump in different operating conditions and at maximum load. In addition, the electrical power drawn by the electric motor has been measured. The efficiencies of the existing pumps and electric motor have been calculated by using the measured data.

Potential energy saving opportunities have been studied by taking into account the results of the calculations for each pump and electric motor. As a conclusion, improvements should be made each system. The required investment costs for these improvements have been determined, and simple payback periods have been calculated.

The main energy saving opportunities result from: replacements of the existing low efficiency pumps, maintenance of the pumps whose efficiencies start to decline at certain range, replacements of high power electric motors with electric motors that have suitable power, usage of high efficiency electric motors and elimination of cavitation problems.