Graphene nanoplatelets (GNPs) are extremely useful nanofillers in epoxy in carbon fiber‐reinforced polymer (CFRP) composites as they make CFPRs sustain higher loads before failure in different kinds ...of loading for example flexural, tensile and fatigue. The current study aims to investigate the effect of GNP coating on carbon fibers on the deformation modes of CFRPs under flexural loading. Laminates have been fabricated using vacuum‐assisted resin transfer molding (VARTM) after spray coating GNPs on unidirectional carbon fiber fabrics. One set of flexural tests were carried out where the strain was recorded using DIC and the other set had in‐situ deformation while recording optical images to monitor deformation. Since, the most probable causes of failure under flexural loading are local compression, shear or contact stresses due to a sharp ram, other mechanical tests like compression test and nano‐indentation were also carried out on the composites. Compressive stress–strain response was ascertained using combined loading compression (CLC) fixture and digital image corelation (DIC) while contact response was evaluated using nanoindentation. GNP‐coated CFRPs were shown to have an increase in compressive modulus of 16% and failure strain of 6%, respectively. Axial and transverse strains measured through DIC were more than two times higher in GNP‐coated CFRPs. Nano‐indentation tests across the entire composite showed some data with intermediate modulus (~10–45 GPa) and hardness (~1–5 GPa) between the epoxy and the fiber and this corresponded to an interphase region which was thicker in 0.4GNP laminate compared to pristine laminate. Flexural strength, flexural modulus and strain at maximum stress improved by 10%, 8%, and 9% respectively in GNP‐coated CFRPs compared to uncoated CFRPs. In addition, while pristine laminates showed non‐uniform distribution of strains during flexural loading, the distribution of strains was much more uniform in GNP‐coated laminate. However, in both kinds of laminates, the failure initiation was in the region of compressive bending stresses.
Highlights
GNP‐added laminate showed an intermediate modulus and hardness interphase through a nanoindentation test.
Digital image correlation analysis has been performed to obtain the strain maps during compressive and flexural loading.
GNP‐added laminates showed higher failure strains compared to pristine laminates under the compressive loads.
GNP‐added laminates performed well under flexural loading.
Flexural response and damage evolution in GNP‐coated carbon fiber epoxy composites manufactured through VARTM technique.
Transition-metal activated phosphors are an important family of luminescent materials that can produce white light with an outstanding color rendering index and correlated color temperature for use ...in light-emitting diodes. In recent years, work in this quite "hot" research field has focused on the development of Mn
2+
and Mn
4+
activated red phosphors. In this review article, we provide an overview of recent studies on Mn
2+
and Mn
4+
doped phosphors, including detailed synthesis routes (solid-state reaction and wet-chemical synthesis) and description of luminescence mechanisms and phosphors' behaviors; discuss their promising applications in white light-emitting diodes; and present an extensive list of references to representative works in this field.
Transition-metal activated phosphors are an important family of luminescent materials that can produce white light with an outstanding color rendering index and correlated color temperature for use in light-emitting diodes.
There are various methods being tried to address the sluggish kinetics observed in Al-ion batteries (AIBs). They mostly deal with morphology tuning, but have led to limited improvement. A new ...approach is proposed to overcome this limitation. It focuses on the use of a redox additive modified electrolyte in combination with framework like materials, which have wider channels. The ordered microporous and interconnected framework of ZIF 67, with large surface area, effectively facilitates the diffusion of aluminum ions. Therefore, AIBs are able to exhibit a superior discharge capacity of 288 mAh g–1 at 0.2 A g–1 current density with robust cycling stability. The addition of potassium ferricyanide as a redox-active species in an aqueous solution of aluminum chloride (supporting electrolyte) leads to significant enhancement in the specific capacity with much higher cycling stability. Al-ion based BatCap devices can be assembled by using ZIF 67 as the cathode, ZIF 67 derived porous carbon as the anode, and a redox additive modified electrolyte. The BatCap device exhibits excellent energy density of 86 Wh kg–1 at a power density of 2 KW kg–1, which is higher than reported aqueous AIBs. The ex situ characterization clearly explains the unexplored mechanism of redox additives in AIBs.
LED lamps using phosphor downconversion can be designed to replace incandescent or halogen sources with a “warm-white” correlated color temperature (CCT) of 2700−3200 K and a color rendering index ...(CRI) greater than 90. However, these lamps have efficacies of ∼70% of standard “cool-white” LED packages (CCT = 4500−6000 K; CRI = 75−80). In this report, we describe structural and luminescence properties of fluoride and oxyfluoride phosphors, specifically a (Sr,Ca)3(Al,Si)O4(F,O):Ce3+ yellow-green phosphor and a K2TiF6:Mn4+ red phosphor, that can reduce this gap and therefore meet the spectral and efficiency requirements for high-efficacy LED lighting. LED lamps with a warm-white color temperature (3088 K), high CRI (90), and an efficacy of ∼82 lm/W are demonstrated using these phosphors. This efficacy is ∼85% of comparable cool-white lamps using typical Y3Al5O12:Ce3+-based phosphors, significantly reducing the efficacy gap between warm-white and cool-white LED lamps that use phosphor downconversion.
A proposal for staging COVID‐19 coagulopathy Thachil, Jecko; Cushman, Mary; Srivastava, Alok ...
Research and practice in thrombosis and haemostasis,
July 2020, Letnik:
4, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Coronavirus disease 2019 (COVID‐19) is associated with significant hypercoagulability. However, despite prophylactic anticoagulation, critically ill patients with this condition develop thromboses. ...This forum discusses the lungs as the epicenter for the hemostatic issues, puts forward a proposal for staging COVID‐19 coagulopathy based on available diagnostic markers, and suggest considering current and future treatment options based on these different stages.
Allogeneic hematopoietic stem cell transplantation has been well established for several decades as gene replacement therapy for patients with thalassemia major, and now offers very high rates of ...cure for patients who have access to this therapy. Outcomes have improved tremendously over the last decade, even in high-risk patients. The limited data available suggests that the long-term outcome is also excellent, with a >90% survival rate, but for the best results, hematopoietic stem cell transplantation should be offered early, before any end organ damage occurs. However, access to this therapy is limited in more than half the patients by the lack of suitable donors. Inadequate hematopoietic stem cell transplantation services and the high cost of therapy are other reasons for this limited access, particularly in those parts of the world which have a high prevalence of this condition. As a result, fewer than 10% of eligible patients are actually able to avail of this therapy. Other options for curative therapies are therefore needed. Recently, gene correction of autologous hematopoietic stem cells has been successfully established using lentiviral vectors, and several clinical trials have been initiated. A gene editing approach to correct the β-globin mutation or disrupt the BCL11A gene to increase fetal hemoglobin production has also been reported, and is expected to be introduced in clinical trials soon. Curative possibilities for the major hemoglobin disorders are expanding. Providing access to these therapies around the world will remain a challenge.
Selectivity and enhanced sensitivity for surface-enhanced Raman scattering (SERS) substrates are highly desirable attributes for their analytical applications. SERS substrate interaction with target ...molecules plays a key role in determining the enhancement magnitude and spectral profile of the SERS signal as well as their applications. Herein, we demonstrate a SERS active substrate based on reduced graphene oxide/silver nanoparticles (rGO/Ag NPs) composite material synthesized by a facile wet chemical route. The Ag NPs decorated rGO nanosheet has been achieved by reducing AgNO3 with ethylene glycol in the presence of poly vinyl pyrrolidone (PVP) and NaCl over layered graphene oxide. The addition of PVP stimulates the nano-phase growth as well as uniform distribution of the Ag NPs on rGO nanosheet. The well synthesized rGO/Ag composite was confirmed by using various characterization techniques such as FESEM, HRTEM, XRD, FTIR and Raman. Further, the rGO/Ag NPs composite material has been utilized as a platform for SERS based selective detection of Rhodamine-6G, 4-mercapto benzoic acid, and 2,4-dinitrotoluene analytes. The rGO/Ag NPs substrate demonstrates good homogeneity, stability and nanomolar sensitivity with Raman intensity enhancement of the order of 5 for Rh-6G and 4-MBA whereas 3 for 2,4-DNT. The observed enhancement of SERS signal for all the analytes has been attributes to the cumulative effect of rGO and Ag NPs.
Display omitted
•We fabricated and demonstrated a generic SERS sensor based on Ag-rGO composite.•Wet chemical process has been used for the decoration of spherical silver nanoparticles on the rGO nano sheets.•The loading density of the Ag NPs on rGO nanosheet depends on AgNO3 molar concentration.•The optimized concentration of AgNO3 and GO for highest enhancement in Raman intensities was 0.01M and 2.5mg respectively.•Synthesized nanocomposite acts as SERS sensitive substrate for the detection of Rh-6G, 4-MBA, and 2,4-DNT up to the nM range.•The enhancement factors are found to be 5 orders of magnitude for Rh-6G, 4-MBA and 3 orders of magnitude for 2,4-DNT.
In pancytopenia due to aplastic anemia (AA), bone marrow hypocellularity leads to hazardous failure of hematopoiesis. Āyurveda treatment was given to a 30-year-old male patient known case of severe ...acquired AA, considering it under Pāṇḍūroga (~anemia). A study was carried out to search the effectiveness of Āyurveda medications, especially Rasāyana (~immunomodulator) mentioned in the treatment of Pāṇḍū in the management of AA. The patient was administered Rasāyana drugs, such as Śilājatukalpa, Amṛītā-Satta, Punarnavā, and Maṇḍūr having hepatoprotective, anxiolytic, and antioxidant properties, and ĀrogyavardhanīVaṭī, TrikaṭūCūrṇa. Hematological investigations of the patient were carried out every 2 months for 2 and ½ years. Erythrocyte sedimentation rate, white blood cell, and red cell distribution width coefficient of variation were in the normal range after treatment. Red blood cells, HB, and platelets were found to be increased, which were not growing before treatment. Liver function test, kidney function test, serum sodium, and potassium were normal during treatment. Complete relief in symptoms was found. The present study concludes that the severity of pancytopenia due to AA can be managed effectively with Ayurvedic medications.
Rapid detection technologies with high sensitivity and selectivity for plant pathogens are essential to prevent disease spread and minimize losses to assure optimal productivity and food security. ...Traditional laboratory techniques such as microscopy and culture are time-consuming, labour intensive and require complex sample handling. Immunological and molecular techniques have advanced but have some issues related to rapidity, signal strength and instrumentation. The integration of immunological and molecular diagnostics with nanotechnology systems offers an option where all detection steps can be accommodated on a portable miniaturized device for rapid and accurate detection of plant pathogens. The sensitive nature of functionalized nanoparticles can be used to design phytopathogen detection devices with smart sensing capabilities for field use. This review summarizes the current status and future prospects of nanotechnology for detection and diagnosis of plant pathogens.
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