Reduced real lifetime of PV panels – Economic consequences

The maintenance and analyzing failures of PV systems and plants are becoming more and more important issues. Our data from the long-term operation of 85 photovoltaic power plants in central Europe show that their actual lifetime is about half that of the originally planned lifetime. After about 10 years, serious failures of 1st tier (bankable) PV panels occur at an increasing rate. This article presents selected typical data and describes the most serious failures. Furthermore, economic calculations of returns on investment are carried out in relation to the price of electricity, which is currently changing at a rapid pace. It shows that the PV panel lifetime reduction from 20 to 30 years, declared at commercial leaflets, to real lifetime about 10–12 years can reduce PV power plant profit substantially, but the investment is still worth it. The reason is that after 10–12 years ser vice/maintenance expenses to replace damaged PV panels and inverters are growing very quickly. The new information could be helpful for owners of PV power plants to get a more realistic estimation of profits

Use of the distribution logistic in the company

Import 13/11/2006Prezenční152 - Katedra podnikohospodářsk

Expansion of production and its economic evaluation

Tato diplomová práce má za cíl poskytnout základ pro finální rozhodnutí o přijetí či nepřijetí definovaného investičního záměru podniku XY, který podniká v nábytkářském sektoru. Smyslem investice je rozšíření výrobních kapacit prostřednictvím výstavby nové haly a nákupu technologického zařízení. Teoretická část vymezuje pojmy související s investováním, definuje proces přípravy a realizace projektů, dále formuluje stanovení podkladů dané investice a metody hodnocení investice. V praktické části jsou aplikovány vymezené poznatky související s problematikou hodnocení investic. Poslední kapitola poskytuje celkové zhodnocení investice.This diploma thesis intends to provide the basis for the final decision on the acceptance or non-acceptance of a defined investment plan of a company XY, which runs a business it the furniture sector. The purpose of the investment is to expand the production capacity through the construction of a new hall and the purchase of technological equipment. The theoretical part defines the terms related to investment, defines the process of preparation and implementation of projects, further formulates the determination of the basis investments and methods of investment evaluation. In the practical part, defined knowledge related to the issue of investment evaluation is applied. The last chapter provides the overall evaluation of the investment.Fakulta ekonomicko-správníStudent přednesl téma své DP ''Rozšíření výroby a jeho ekonomické zhodnocení'', otázka vedoucí práce: 1. Jaké faktory by mohly v současné době ovlivnit rozhodnutí managementu o realizaci nové investice? Otázka oponenta DP: 1. Jedním z rozhodujících faktorů pro efektivnost investice, který se promítá do všech zmíněných metod hodnocení, je predikovaný příjem, který je očekáván díky realizaci posuzované investice. Nakolik se v posledním roce promítla do velikosti příjmů podniku pandemie Covid a nakolik by mohla ovlivnit efektivnost posuzované investice v budoucnu? Student otázky zodpověděl.Dokončená práce s úspěšnou obhajobo

Residential real estate market analysis

Bakalářská práce se zabývá rezidenčním trhem nemovitostí. Teoretická část se zaměřuje na vymezení jednotlivých dílčích segmentů nemovitostního trhu. Práce se dále věnuje způsobům, které jsou využívány při financování nemovitostí. Poté je teoreticky formulována problematika developerské činnosti. Praktická část bakalářské práce se zaměřuje na provedení komparace developerských projektů zahrnující dílčí analýzu rezidenčního trhu ve vybraném regionu.The bachelor thesis deals with the residential real estate market. The theoretical part focuses on the definition of individual segments of the real estate market. The thesis also deals with the ways that are used in real estate financing. Then, the issue of developer activity is theoretically formulated. The practical part of the bachelor thesis focuses on the implementation of a comparison of development projects involving a partial analysis of the residential market in the selected region.Fakulta ekonomicko-správníStudent nejdříve prezentoval svoji bakalářskou práci Analýza rezidenčního trhu nemovitosti. Cíl práce:Cílem práce je analyzovat rezidenční trh nemovitostí, včetně komparace vybraného projektu s konkurenčními projekty ve zvoleném regionu. Otázky vedoucího práce: Jaký je názor bakalanta na zpřísnění podmínek pro poskytování hypotečních a spotřebitelských úvěrů Českou národní bankou, např. LTV, DTI či DTSI? Odpovědi na otázky vedoucího práce i odpovědi na další doplňující otázky členů zkušební komise byly vyhovující

Ball milling: A top down facile approach to synthesize AgInSe2 nanostructures

A quantum dot solar cell is an emerging field in solar cell research that uses quantum dots as the photovoltaic material. Quantum dots have band gaps that are tunable across a wide range of energy levels by changing the quantum dot size. The embedment of different sized dots within absorbing layer encourages harnessing of the maximum spectrum energy. Also other effects like very high surface to volume ratio, Quantum Transport make them attractive for future devices. For an attempt of AIS quantum dots (QDs), AIS nanoparticles with tetragonally distorted phase were prepared by mechanically alloying the synthesized bulk AIS powder at room temperature in a planetary ball mill under Ar. Nanoparticles are formed with range -10 nm in size. These ball-milled nanoparticles contain different shapes, and the Rietveld analysis of X-ray powder diffraction data reveals their detailed structural features. High resolution transmission electron microscope (HRTEM) images also detect the presence of the tetragonal phase in ball-milled samples. Peak Broadening (FWHM), which is the main characteristics of decrease in size, is observed. XRD data reveals the downscaling of crystallite from 103 nm to 7 nm, also tetragonally distorted structure of the system was not disturbed by milling. The DSC study also reveals the phase evolution and crystallization kinetics. Bulk samples show endo melting peak at 134 °C and 220 °C. Cooling-crystallization complexity of the peak/peaks signifies crystallization from melt was heterogeneous nucleation and crystallization from multiple types of centers. Unlike this, milled samples show two crystallization effects at approx. 135 °C and 380 °C. Optical properties were investigated to find band edges, and suggest it around 1.3 eV which is encouraging for photovoltaic applications

Task criticalness potential: A multiple criteria approach to project management

summary:The paper proposes the method evaluating tasks criticalness potential, which has been analysed by various project management tools. The criticalness potential of tasks, as opposed to a simple differentiation of tasks to critical and non-critical using the CPM method, considers not only time, but also resource, cost and topological aspects of a project schedule. In the paper, the tasks criticalness potential is defined applying task criticalness indicators which are further used as input for three various multiple criteria decision models. These models enable taking into account the principal project success criteria, i. e. time, resources and cost. The tasks criticalness potential cannot be determined using one indicator or one characteristic only. A selected multi-criteria approach based on task criticalness indicators differentiates between tasks more and less threatening to a project. This paper suggests different multiple criteria approaches to the quantification of task criticalness potential, compares them and discusses their advantages and disadvantages

The Selection and Validation of Reference Genes for mRNA and microRNA Expression Studies in Human Liver Slices Using RT-qPCR

The selection of a suitable combination of reference genes (RGs) for data normalization is a crucial step for obtaining reliable and reproducible results from transcriptional response analysis using a reverse transcription-quantitative polymerase chain reaction. This is especially so if a three-dimensional multicellular model prepared from liver tissues originating from biologically diverse human individuals is used. The mRNA and miRNA RGs stability were studied in thirty-five human liver tissue samples and twelve precision-cut human liver slices (PCLS) treated for 24 h with dimethyl sulfoxide (controls) and PCLS treated with β-naphthoflavone (10 µM) or rifampicin (10 µM) as cytochrome P450 (CYP) inducers. Validation of RGs was performed by an expression analysis of CYP3A4 and CYP1A2 on rifampicin and β-naphthoflavone induction, respectively. Regarding mRNA, the best combination of RGs for the controls was YWHAZ and B2M, while YWHAZ and ACTB were selected for the liver samples and treated PCLS. Stability of all candidate miRNA RGs was comparable or better than that of generally used short non-coding RNA U6. The best combination for the control PCLS was miR-16-5p and miR-152-3p, in contrast to the miR-16-5b and miR-23b-3p selected for the treated PCLS. Our results showed that the candidate RGs were rather stable, especially for miRNA in human PCLS

Sesquiterpenes Are Agonists of the Pregnane X Receptor but Do Not Induce the Expression of Phase I Drug-Metabolizing Enzymes in the Human Liver

Sesquiterpenes, the main components of plant essential oils, are bioactive compounds with numerous health-beneficial activities. Sesquiterpenes can interact with concomitantly administered drugs due to the modulation of drug-metabolizing enzymes (DMEs). The aim of this study was to evaluate the modulatory effects of six sesquiterpenes (farnesol, cis-nerolidol, trans-nerolidol, α-humulene, β-caryophyllene, and caryophyllene oxide) on the expression of four phase I DMEs (cytochrome P450 3A4 and 2C, carbonyl reductase 1, and aldo-keto reductase 1C) at both the mRNA and protein levels. For this purpose, human precision-cut liver slices (PCLS) prepared from 10 patients and transfected HepG2 cells were used. Western blotting, quantitative real-time PCR and reporter gene assays were employed in the analyses. In the reporter gene assays, all sesquiterpenes significantly induced cytochrome P450 3A4 expression via pregnane X receptor interaction. However in PCLS, their effects on the expression of all the tested DMEs at the mRNA and protein levels were mild or none. High inter-individual variabilities in the basal levels as well as in modulatory efficacy of the tested sesquiterpenes were observed, indicating a high probability of marked differences in the effects of these compounds among the general population. Nevertheless, it seems unlikely that the studied sesquiterpenes would remarkably influence the bioavailability and efficacy of concomitantly administered drugs

Inter-Individual Variability in Acute Toxicity of R-Pulegone and R-Menthofuran in Human Liver Slices and Their Influence on miRNA Expression Changes in Comparison to Acetaminophen

Monoterpenes R-pulegone (PUL) and R-menthofuran (MF), abundant in the Lamiaceae family, are frequently used in herb and food products. Although their hepatotoxicity was shown in rodent species, information about their effects in human liver has been limited. The aim of our study was to test the effects of PUL, MF and acetaminophen (APAP, as a reference compound) on cell viability and microRNA (miRNA) expression in human precision-cut liver slices. Slices from five patients were used to follow up on the inter-individual variability. PUL was toxic in all liver samples (the half-maximal effective concentration was 4.0 µg/mg of tissue), while MF and surprisingly APAP only in two and three liver samples, respectively. PUL also changed miRNA expression more significantly than MF and APAP. The most pronounced effect was a marked decrease of miR-155-5p expression caused by PUL even in non-toxic concentrations in all five liver samples. Our results showed that PUL is much more toxic than MF and APAP in human liver and that miR-155-5p could be a good marker of PUL early hepatotoxicity. Marked inter-individual variabilities in all our results demonstrate the high probability of significant differences in the hepatotoxicity of tested compounds among people