Study of the Enhancement of the Efficiency of the Monocrystalline Silicon Solar Cell by Optimizing Effective Parameters Using PC1D Simulation

Silicon - In this paper, simulation of a monocrystalline silicon solar cell was done using PC1D software. The impact of different solar cell parameters, with their effects on power and efficiency,...     

Chromophore-Free Sealing and Repair of Soft Tissues Using Mid-Infrared Light-Activated Biosealants

Poor strength, infection, leakage, long procedure times, and inflammation limit the efficacy of common tissue sealing devices in surgeries and trauma. Light-activated sealing is attractive for tissue sealing and repair, and can be facilitated by the generation of local heat following absorption of nonionizing laser energy by chromophores. Here, the inherent ability of biomaterials is exploited to absorb nonionizing, mid-infrared (midIR) light in order to engender rapid photothermal sealing and repair of soft tissue wounds. In this approach, the biomaterial simultaneously acts as a photothermal convertor as well as a biosealant, which dispenses the need for exogeneous light-absorbing nanoparticles or dyes. Biomechanical recovery, mathematical modeling, histopathology analyses, tissue strain mapping using digital imaging correlation, and visualization of the biosealant-tissue interface using hyperspectral imaging indicate superior performance of midIR sealing in live mice compared to conventional sutures and glue. The midIR-biosealant approach demonstrates rapid sealing of soft tissues, improves cosmesis, lowers potential for scarring, obviates safety concerns because of the nonionizing light used, and allows adoption of a wide diversity of biomaterials. Taken together, the studies demonstrate a novel advance both in biomaterials for surgical sealing along with the use of nonionizing midIR light, with high potential for clinical translation.     

Revisiting Continental U.S. Hydrologic Change in the Latter Half of the 20th Century

An intensified hydrologic cycle and a large amount of monitoring flow data in the latter half of the 20th century attracted a lot of research on the continental U.S. hydrologic change. However, most previous studies are based on HCDN (Hydro-Climate Data Network) dataset with a period of ~1950s ?1988. This study analyzed hydrologic change in continental U.S. based on MOPEX (international Model Parameter Estimation Experiment) hydrology dataset with a period of ~1950s ?2000 for 302 watersheds (gages) across diverse climate, vegetation and soil conditions. This dataset is more representative of the latter half of the 20th century than HCDN. In contrast with previous studies, this study shows that only 20–30 % of watersheds present increasing trends in flow (streamflow, Q; baseflow, Q_bf; baseflow index, BFI), and most (> 65 %) watersheds presents non-significant trends. Similar to previous studies, the watersheds with increasing trends in Q and Q_bf are concentrated in Midwest and high plain (North-Central area) of USA. Climate contributes more to Q change (61?±?25 % vs. 39?±?25 %) but slightly less to Q_bf change than human activity (49?±?26 % vs. 51?±?26 %) and much less to BFI change than human activity (?5?±?61 % vs. 105?±?61 %). A step change at ~1971 in Q and Q_bf was found for 35–45 % but not for a large proportion of watersheds (50 % or more was reported by previous studies). This study provides new insights on the latter half of the 20th century’s hydrologic cycle for the continental U.S. with a more representative dataset of this period.     

Epoxy Resin Composite Reinforced with Carbon Fiber and Inorganic Filler: Overview on Preparation and Properties

Among carbon fillers, carbon fiber is considered to be an ideal reinforcement for epoxy because of its outstanding electrical, mechanical, and thermal features. Several inorganic fillers such as zinc oxide, titania, and silica are also used in epoxy matrix for property enhancement. The review initially focuses the preparation methods and physical characteristics of epoxy/carbon fiber composite. Afterward, fabrication and properties of epoxy/zinc oxide/titania/silica composites are also conversed. Moreover, the effect of filler dispersion on polymer properties’ improvement is also highlighted. Epoxy/carbon fiber composites are employed more frequently and effectively in defense-related applications compared with epoxy/inorganic nanofiller composite.     

Recent Developments in Different Types of Flame Retardants and Effect on Fire Retardancy of Epoxy Composite

In this review, main focus is on the different types of fire retardants, their properties, and pertinent potential. Both inorganic (titania, silica, and zinc oxide) and organic (graphite, graphene, and graphene nanoplatelet) compounds have been discussed as flame inhibitors. Among various sorts of fire retardants, halogen-based flame inhibitors possess outstanding features. Consequently influence of fire retardant on the performance of epoxy composite has been discussed. It was noted that significant enhancement occurs by addition of organic and inorganic fillers in epoxy matrix. However, halogen additives impart better flame resistance to epoxy composite. Toward the end of this review, potential of halogen-containing fire retardant is discussed.     

Advances in Epoxy/Graphene Nanoplatelet Composite with Enhanced Physical Properties: A Review

In this review, development from graphene nanoplatelet, that is, comprised of short bulk of single layer graphene, into modified-polymer/graphene nanoplatelet composite is presented. Preparation methods of graphite, graphene, and graphene nanoplatelets have also been discussed. Graphene nanoplatelet and modified graphene nanoplatelet commend unique properties to composites such as excellent thermal and electrical conductivity as well as mechanical and barrier properties. Graphene nanoplatelet fabrication techniques by solution mixing, melt blending, and in situ polymerization are also discussed. Excellent dispersion of nanoplatelets in polymer/graphene nanoplatelet depends upon the selection of suitable fabrication technique. Moreover, the corresponding significance, exploitation, challenges, and future aspect of polymer/graphene nanoplatelet-based material is overviewed.     

Palynological investigation of some selected species of family Fabaceae from Pakistan,using light and scanning electron microscopy techniques

Pollen morphology of 11 species of family Fabaceae that is, Trifolium alexandrinum, Trifolium resupinatum, Arachis hypogaea, Lathyrus aphaca, Medicago lupulina, Vicia sativa, Lathyrus odoratus, Pongamia pinnata, Melilotus indicus, Medicago polymorpha, Medicago sativa from Pakistan has been investigated by light and scanning electron microscopy. Pollen were generally tricolporate, radially symmetrical, isopolar, elliptic in equatorial view and triangular in polar view under LM. Results showed that pollens were per‐prolate (T. alexandrinum), prolate (T. resupinatum, V. sativa, L. odoratus, Melilotus indicus, M. polymorpha, M. sativa) and sub‐prolate (A. hypogaea, L. aphaca, M. lupulina, P. pinnata). The larger polar/equatorial (P/E) ratio was found in T. alexandrinum (2.26 μm) and the smallest was found in M. lupulina (1.21 μm). The exine of T. resupinatum was 3.00 μm in thickness while others posses smaller exine thickness. The larger pore diameter was found in P. pinnata (16.01 μm) while others have smaller. The length of colpi was larger in Arachis hypogaea (32.24) while others posses smaller. Eight types of surface ornamentation (Psilate, faintly rugulate). Perforate and rugulate to verrucate have been observed under SEM. The pollens were europalynous type. Pollen morphology proved to be useful for the specific delimitation and serve as a tool for the identification and classification of taxa at specific and generic levels and can also be used as a key for the taxonomic features. Diversity in exine sculpture is helpful indicative characters for the isolation of closely related species. Hence, it is clear that both qualitative and quantitative characters of pollen can be useful for differentiating between taxa at specific level.     

Strength properties of polymer mortar panels using methyl methacrylate solution of waste expanded polystyrene as binder

The present study examines the applicability of polymer mortar panels using a methyl methacrylate (MMA) solution of waste expanded polystyrene (EPS) to develop effective recycling processes for the EPS, referring to the strength properties of a polymer-impregnated mortar panel with almost the same performance as commercial products. An MMA solution of EPS is prepared by dissolving EPS in MMA, and unreinforced and steel fiber-reinforced polymer mortars are mixed using the EPS-MMA-based solution as a liquid resin or binder. Polymer mortar panels (PMPs) using the EPS-MMA-based polymer mortars without and with steel fiber and crimped wire cloth reinforcements and steel fiber-reinforced polymer-impregnated mortar panel (PIMP) are prepared on trial, and tested for flexural behavior under four-point loading. The EPS-MMA-based PMPs are more ductile than the PIMP, and have a high load-bearing capacity. Consequently, they can replace PIMP in practical applications.     

Magnetic field effect on electron emission from plasma

The influence of external magnetic field on the significant parameters of electrons from laser induced plasma (LIP) is investigated. A Q-switched Nd:YAG laser (1064 nm, 9-14 ns, 10 mJ, 1.1 MW) is focused on annealed, 4N pure (99.99%) Silver target (2 × 2 × 0.2 cm³) for production of plasma under vacuum ∼10⁻³ torr. Temperature, density and energy measurements for electrons were made by self fabricated Langmuir probe both in the absence and presence of external magnetic field (∼1.2 T) at different positions. The signals are recorded on 200 MHz UTT 2202 digital storage oscilloscope. The results thus obtained reveal decrease in electron temperature, energy and density in presence of external magnetic field. Confinement of plasma is also observed.     

Investigations on hard X-rays from laser induced plasmas

Investigations are performed on significant parameters of Hard X-Rays emitted from metallic plasmas. Nd: YAG (1064 nm, 9-14 ns, 1.1 MW) laser is irradiated on three 4 N pure Lead (Pb), Platinum (Pt) and Copper (Cu) targets under vacuum ∼ 10⁻³ torr. The plasma plume images were captured by Charged Coupled Device (CCD). The Hard X-rays were detected by Photomultiplier tube. The signals thus produced were stored in digital storage oscilloscope. Variation takes place in the parameters of emitted x-rays with atomic numbers/mass of target. The intensity of emitted x-rays increases with the increase in atomic mass of the target materials used.