Metallization of solar cells, exciton channel of plasmon photovoltaic effect in perovskite cells

Abstract Metallic nanoparticles are used to improve solar cell efficiency due to plasmon mediated photo-voltaic effect. We present various channels of this phenomenon in semiconductor solar cells with p − n junction and in chemical-type cells with exciton photovoltaic mechanism. Besides of previously known by plasmon strengthening of sun light absorption in metalized solar cells we have described the influence of plasmonic nanoparticles onto internal electricity of cells. The latter case we analyze on the example of hybridized perovskite solar cells regarded as most promising cells of III-rd generation. The explanation of recent experimental achievements with the metallization of perovskite cells is presented in comparison to the metallization of conventional Si-based cells

Experience of machine vision application in optical NDT systems

Two automated optical inspection systems – for defects detection of in the ligature under UV irradiation and for non-destructive testing of pipeline inner surface – were described. The features of constructions and algorithms of the developed software with using the computer vision techniques were presented. Engineered systems were introduced successfully into commercial operation.Описаны две автоматизированные системы оптического контроля – для обнаружения дефектов в лигатуре под ультрафиолетовым облучением и для внутритрубной дефектоскопии поверхности. Представлены особенности конструкций и алгоритмы функционирования разработанного программного обеспечения с использованием методов технического зрения. Сконструированные системы успешно сданы в промышленную эксплуатацию

SYSTEM FOR SUPPORT OF INVENTIVE PROBLEM SOLVING: REVIEW, ANALOGS AND THE PROPOSED STRUCTURE

The article provides an overview of software solutions to support solving research problems. Four analogs were analyzed and evaluated in review. An original architecture for the system is proposed

Interacting circular nanomagnets

Regular 2D rectangular lattices of permalloy nanoparticles (40 nm in diameter) were prepared by the method of the electron lithography. The magnetization curves were studied by Hall magnetometry with the compensation technique for different external field orientations at 4.2K and 77K. The shape of hysteresis curves indicates that there is magnetostatic interaction between the particles. The main peculiarity is the existence of remanent magnetization perpendicular to easy plain. By numerical simulation it is shown, that the character of the magnetization reversal is a result of the interplay of the interparticle interaction and the magnetization distribution within the particles (vortex or uniform).Comment: 16 pages, 8 figure

Effect of gallium doping on the characteristic properties of polycrystalline cadmium telluride thin film

Ga-doped CdTe polycrystalline thin films were successfully electrodeposited on glass/fluorine doped tin oxide (FTO) substrates from aqueous electrolytes containing cadmium nitrate (Cd(NO3)2⸱4H2O) and tellurium oxide (TeO2). The effects of different Ga-doping concentrations on the CdTe:Ga coupled with different post-growth treatments were studied by analysing the structural, optical, morphological and electronic properties of the deposited layers using X-ray diffraction (XRD), ultraviolet-visible spectrophotometry, scanning electron microscopy, photoelectrochemical cell measurement and direct-current conductivity test respectively. XRD results show diminishing (111)C CdTe peak above 20 ppm Ga-doping and appearance of (301)M GaTe diffraction above 50 ppm Ga-doping indicating the formation of two phases; CdTe and GaTe . Although, reductions in the absorption edge slopes were observed above 20 ppm Ga-doping for the as-deposited CdTe:Ga layer, no obvious influence on the energy gap of CdTe films with Ga-doping were detected. Morphologically, reductions in grain size were observed at 50 ppm Ga-doping and above with high pinhole density within the layer. For the as-deposited CdTe:Ga layers, conduction type change from n- to p- were observed at 50 ppm, while the n-type conductivity were retained after post-growth treatment. Highest conductivity was observed at 20 ppm Ga-doping of CdTe. These results are systematically reported in this pape

GSK3β is a negative regulator of the transcriptional coactivator MAML1

Glycogen synthase kinase 3β (GSK3β) is involved in several cellular signaling systems through regulation of the activity of diverse transcription factors such as Notch, p53 and β-catenin. Mastermind-like 1 (MAML1) was originally identified as a Notch coactivator, but has also been reported to function as a transcriptional coregulator of p53, β-catenin and MEF2C. In this report, we show that active GSK3β directly interacts with the MAML1 N-terminus and decreases MAML1 transcriptional activity, suggesting that GSK3β might target a coactivator in its regulation of gene expression. We have previously shown that MAML1 increases global acetylation of histones, and here we show that the GSK3 inhibitor SB41, further enhances MAML1-dependent histone acetylation in cells. Finally, MAML1 translocates GSK3β to nuclear bodies; this function requires full-length MAML1 protein

The transcriptional coactivator MAML1 regulates p300 autoacetylation and HAT activity

MAML1 is a transcriptional coregulator originally identified as a Notch coactivator. MAML1 is also reported to interact with other coregulator proteins, such as CDK8 and p300, to modulate the activity of Notch. We, and others, previously showed that MAML1 recruits p300 to Notch-regulated genes through direct interactions with the DNA–CSL–Notch complex and p300. MAML1 interacts with the C/H3 domain of p300, and the p300–MAML1 complex specifically acetylates lysines of histone H3 and H4 tails in chromatin in vitro. In this report, we show that MAML1 potentiates p300 autoacetylation and p300 transcriptional activation. MAML1 directly enhances p300 HAT activity, and this coincides with the translocation of MAML1, p300 and acetylated histones to nuclear bodies

Regulation of the Mitogen Activated Protein Kinase Kinase (MEK)-1 by NAD-Dependent Deacetylases

Sirtuins are class III deacetylases that regulate many essential processes, including cellular stress, genome stability, and metabolism. Although these NAD+-dependent deacetylases control adaptive cellular responses, identification of sirtuin-regulated signaling targets remain under-studied. Here, we demonstrate that acetylation of the mitogen-activated protein kinase kinase-1 (MEK1) stimulates its kinase activity, and that acetylated MEK1 is under the regulatory control of the sirtuin family members SIRT1 and SIRT2. Treatment of cells with sirtuin inhibitors, or siRNA knockdown of SIRT1 or SIRT2 proteins, increases MEK1 acetylation and subsequent phosphorylation of the extracellular signal-regulated kinase (ERK). Generation of an acetyl-specific MEK1 antibody demonstrates that endogenous acetylated MEK1 is extensively enriched in the nucleus following epidermal growth factor (EGF) stimulation. An acetyl-mimic of MEK1 increases inappropriate growth properties, suggesting that acetylation of MEK1 has oncogenic potential

Preliminary analysis of immune activation in early onset type 2 diabetes

Introduction. First Nations and other Aboriginal children are disproportionately affected by cardiometabolic diseases, including type 2 diabetes (T2D). In T2D, the disruption of insulin signalling can be driven by pro-inflammatory immunity. Pro-inflammatory responses can be fueled by toll-like receptors (TLR) on immune cells such as peripheral blood mononuclear cells (PBMC, a white blood cell population). TLR4 can bind to lipids from bacteria and food sources activating PBMC to produce cytokines tumour necrosis factor (TNF)-α and interleukin (IL)-1β. These cytokines can interfere with insulin signalling. Here, we seek to understand how TLR4 activation may be involved in early onset T2D. We hypothesized that immune cells from youth with T2D (n=8) would be more reactive upon TLR4 stimulation relative to cells from age and body mass index (BMI)-matched controls without T2D (n=8). Methods. Serum samples were assayed for adipokines (adiponectin and leptin), as well as cytokines. Freshly isolated PBMC were examined for immune reactivity upon culture with TLR4 ligands bacterial lipopolysaccharide (LPS, 2 and 0.2 ng/ml) and the fatty acid palmitate (200 µM). Culture supernatants were evaluated for the amount of TNF-α and IL-1β produced by PBMC. Results. Youth with T2D displayed lower median serum adiponectin levels compared to controls (395 vs. 904 ng/ml, p<0.05). PBMC isolated from youth with and without T2D produced similar levels of TNF-α and IL-1β after exposure to the higher LPS concentration. However, at the low LPS dose the T2D cohort exhibited enhanced IL-1β synthesis relative to the control cohort. Additionally, exposure to palmitate resulted in greater IL-1β synthesis in PBMCs isolated from youth with T2D versus controls (p<0.05). These differences in cytokine production corresponded to greater monocyte activation in the T2D cohort. Conclusion. These preliminary results suggest that cellular immune responses are exaggerated in T2D, particularly with respect to IL-1β activity. These studies aim to improve the understanding of the biology behind early onset T2D and its vascular complications that burden First Nations people