Flexibilitätsoptionen im industriellen Umfeld an verschiedenen Energiehandelsmarktplätzen im Smart Grid

Die Energieversorgung in Deutschland befindet sich in einem Umstrukturierungsprozess. Die Liberalisierung, der Ausbau der Erneuerbaren Energien, der Ausstieg aus der Atomenergie und die damit verbundenen Herausforderungen sind die drei wesentlichen Aspekte, die an dieser Stelle zu nennen sind. Die vorliegende Arbeit soll zu diesem Umstrukturierungsprozess einen Beitrag leisten. Im Fokus dieser Arbeit steht die kurzfristige Nachfrageflexibilisierung im industriellen Umfeld und deren Vermarktung an Energiehandelsplätzen. Es werden relevante Märkte bezüglich ihrer Eigenschaften wie handelbaren Produkte, Vertragsbeziehungen, Fristen und Angebotserstellung illustriert. Für die Vermarktung kurzfristiger Flexibilitäten seitens der Nachfrage bietet u.a. der Spotmarkt aufgrund des kleinen Zeitfensters zwischen Handelsangebot und der physikalischen Handelserfüllung Potenzial für kurzfristige Optimierungsmaßnahmen. Im industriellen Bereich existieren zu den bereits heute in der Praxis genutzten Flexibilitäten Potenziale, um den Grad der Nachfrageflexibilisierung weiter zu steigern. National wird Nachfrageflexibilisierung aktuell zur Spitzenlastbegrenzung und für den Regelenergiemarkt eingesetzt. In Zukunft muss der Aktionsraum der Nachfrageflexibilisierung erweitert werden. Ein Industrieunternehmen, welches über die Börse seinen Strom bezieht und regelmäßig Prognosen über Sonne und Wind von Dienstleistern erhält, kann durch die Vermarktung von Flexibilitäten im eigenen Produktionsprozess profitieren. Industrielle Nachfrageflexibilisierung kann nur sehr individuell realisiert werden. Für den optimalen Einsatz kurzfristiger Nachfrageflexibilisierung muss das Industrieunternehmen seine Handelsstrategie an den Tagesverlauf bzw. Wochentag und Jahreszeit anpassen. Die Einspeisung von Erneuerbaren Energien wirkt sich bereits heute auf die Marktpreise aus. Dieser Einfluss wird in Zukunft weiter zunehmen. Die Strombezugskosten eines Industrieunternehmens können durch Umsetzung der Strukturierten Beschaffung im Vergleich zu einem Vollversorgungsvertrag deutlich reduziert werden. Ergänzend können weitere Einsparungen durch die Nutzung von Flexibilitäten erzielt werden. Die Entwicklung des Renewable Energy For Industry (REFI)-Modells stellt die Verbindung zwischen dem Angebot von Regenerativen Energien, der Nutzung von Flexibilitäten innerhalb eines realen Produktionsprozesses und deren Vermarktung am Spotmarkt dar. Es können sowohl aus energetischer – Erhöhung des Anteils Regenerativer Energien im bezogenen Strommix – als auch aus monetärer Perspektive – Reduktion der Strombezugskosten – Effizienzsteigerungen erzielt werden

Assessment of the Economic Potential of Microgrids for Reactive Power Supply

As power generation from variable distributed energy resources (DER) grows, energy flows in the network are changing, increasing the requirements for ancillary services, including voltage support. With the appropriate power converter, DER can provide ancillary services such as frequency control and voltage support. This paper outlines the economic potential of DERs coordinated in a microgrid to provide reactive power and voltage support at its point of common coupling. The DER Customer Adoption Model assesses the costs of providing reactive power, given local utility rules. Depending on the installed DER, the cost minimizing solution for supplying reactive power locally is chosen. Costs include the variable cost of the additional losses and the investment cost of appropriately over-sizing converters or purchasing capacitors. A case study of a large health care building in San Francisco is used to evaluate different revenue possibilities of creating an incentive for microgrids to provide reactive power

Flexibilitätsoptionen im industriellen Umfeld an verschiedenen Energiehandelsmarktplätzen im Smart Grid

Die Energieversorgung in Deutschland befindet sich in einem Umstrukturierungsprozess. Die Liberalisierung, der Ausbau der Erneuerbaren Energien, der Ausstieg aus der Atomenergie und die damit verbundenen Herausforderungen sind die drei wesentlichen Aspekte, die an dieser Stelle zu nennen sind. Die vorliegende Arbeit soll zu diesem Umstrukturierungsprozess einen Beitrag leisten. Im Fokus dieser Arbeit steht die kurzfristige Nachfrageflexibilisierung im industriellen Umfeld und deren Vermarktung an Energiehandelsplätzen. Es werden relevante Märkte bezüglich ihrer Eigenschaften wie handelbaren Produkte, Vertragsbeziehungen, Fristen und Angebotserstellung illustriert. Für die Vermarktung kurzfristiger Flexibilitäten seitens der Nachfrage bietet u.a. der Spotmarkt aufgrund des kleinen Zeitfensters zwischen Handelsangebot und der physikalischen Handelserfüllung Potenzial für kurzfristige Optimierungsmaßnahmen. Im industriellen Bereich existieren zu den bereits heute in der Praxis genutzten Flexibilitäten Potenziale, um den Grad der Nachfrageflexibilisierung weiter zu steigern. National wird Nachfrageflexibilisierung aktuell zur Spitzenlastbegrenzung und für den Regelenergiemarkt eingesetzt. In Zukunft muss der Aktionsraum der Nachfrageflexibilisierung erweitert werden. Ein Industrieunternehmen, welches über die Börse seinen Strom bezieht und regelmäßig Prognosen über Sonne und Wind von Dienstleistern erhält, kann durch die Vermarktung von Flexibilitäten im eigenen Produktionsprozess profitieren. Industrielle Nachfrageflexibilisierung kann nur sehr individuell realisiert werden. Für den optimalen Einsatz kurzfristiger Nachfrageflexibilisierung muss das Industrieunternehmen seine Handelsstrategie an den Tagesverlauf bzw. Wochentag und Jahreszeit anpassen. Die Einspeisung von Erneuerbaren Energien wirkt sich bereits heute auf die Marktpreise aus. Dieser Einfluss wird in Zukunft weiter zunehmen. Die Strombezugskosten eines Industrieunternehmens können durch Umsetzung der Strukturierten Beschaffung im Vergleich zu einem Vollversorgungsvertrag deutlich reduziert werden. Ergänzend können weitere Einsparungen durch die Nutzung von Flexibilitäten erzielt werden. Die Entwicklung des Renewable Energy For Industry (REFI)-Modells stellt die Verbindung zwischen dem Angebot von Regenerativen Energien, der Nutzung von Flexibilitäten innerhalb eines realen Produktionsprozesses und deren Vermarktung am Spotmarkt dar. Es können sowohl aus energetischer – Erhöhung des Anteils Regenerativer Energien im bezogenen Strommix – als auch aus monetärer Perspektive – Reduktion der Strombezugskosten – Effizienzsteigerungen erzielt werden

The degree of radiation-induced DNA strand breaks is altered by acute sleep deprivation and psychological stress and is associated with cognitive performance in humans

Study ObjectivesSleep deprivation is associated with impaired immune responses, cancer, and morbidity and mortality, and can degrade cognitive performance, although individual differences exist in such responses. Sleep deprivation induces DNA strand breaks and DNA base oxidation in animals, and psychological stress is associated with increased DNA damage in humans. It remains unknown whether sleep deprivation or psychological stress in humans affects DNA damage response from environmental stressors, and whether these responses predict cognitive performance during sleep deprivation.MethodsSixteen healthy adults (ages 29–52 years; mean age ± SD, 36.4 ± 7.1 years; seven women) participated in a 5-day experiment involving two 8 hr time-in-bed (TIB) baseline nights, followed by 39 hr total sleep deprivation (TSD), and two 8–10 hr TIB recovery nights. A modified Trier Social Stress Test was conducted on the day after TSD. The Psychomotor Vigilance Test measured behavioral attention. DNA damage was assessed in blood cells collected at 5 time points, and blood cells were irradiated ex vivo.ResultsTSD, alone or in combination with psychological stress, did not induce significant increases in DNA damage. By contrast, radiation-induced DNA damage decreased significantly in response to TSD, but increased back to baseline when combined with psychological stress. Cognitively vulnerable individuals had more radiation-induced DNA strand breaks before TSD, indicating their greater sensitivity to DNA damage from environmental stressors.ConclusionsOur results provide novel insights into the molecular consequences of sleep deprivation, psychological stress, and performance vulnerability. They are important for fields involving sleep loss, radiation exposure, and cognitive deficits, including cancer therapy, environmental toxicology, and space medicine.publishe

Review of “Efficient update of redundancy matrices for truss and frame structures”

This is the Open Review of the article "Efficient update of redundancy matrices for truss and frame structures” by Krake et al. published in JTCAM (doi 10.46298/jtcam.9615

DNA Damage and Radiosensitivity in Blood Cells from Subjects Undergoing 45 Days of Isolation and Confinement : An Explorative Study

The effect of confined and isolated experience on astronauts’ health is an important factor to consider for future space exploration missions. The more confined and isolated humans are, the more likely they are to develop negative behavioral or cognitive conditions such as a mood decline, sleep disorder, depression, fatigue and/or physiological problems associated with chronic stress. Molecular mediators of chronic stress, such as cytokines, stress hormones or reactive oxygen species (ROS) are known to induce cellular damage including damage to the DNA. In view of the growing evidence of chronic stress-induced DNA damage, we conducted an explorative study and measured DNA strand breaks in 20 healthy adults. The participants were grouped into five teams (missions). Each team was composed of four participants, who spent 45 days in isolation and confinement in NASA’s Human Exploration Research Analog (HERA). Endogenous DNA integrity, ex-vivo radiation-induced DNA damage and the rates of DNA repair were assessed every week. Our results show a high inter-individual variability as well as differences between the missions, which cannot be explained by inter-individual variability alone. The ages and sex of the participants did not appear to influence the results.publishe

The Automated FADU-Assay, a Potential High-Throughput In Vitro Method for Early Screening of DNA Breakage

Genotoxicity tests are essential to identify compounds that have a potential to compromise not only the environment but also human and animal health, including compounds that increase the risk of cancer. At present, no single test is capable of detecting all types of genotoxic effects; therefore a battery of in vitro and, if positive, in vivo tests is necessary to determine the genotoxicity of a substance. However, the respective specificities of current assays have been criticized for their high percentage of false positive results. We recently published an automated version of the “Fluorimetric detection of Alkaline DNA Unwinding” (FADU) assay for measuring DNA strand breaks in human peripheral blood mononuclear cells or in cell lines. Using this new technology we show detection of DNA strand breaks in cells treated with several compounds known to induce DNA strand breaks by various mechanisms. We also tested toxic compounds that were not expected to induce DNA strand breaks; these were negative in the assay as expected. Finally, we included zinc oxide nanoparticles of high production volume to explore further fields of potential FADU applications. The main advantages of this assay are high reproducibility, easy handling, lack of operator bias, high-throughput, speed, and low cost

Synergistic Effects of Weightlessness, Isoproterenol, and Radiation on DNA Damage Response and Cytokine Production in Immune Cells

The implementation of rotating-wall vessels (RWVs) for studying the effect of lack of gravity has attracted attention, especially in the fields of stem cells, tissue regeneration, and cancer research. Immune cells incubated in RWVs exhibit several features of immunosuppression including impaired leukocyte proliferation, cytokine responses, and antibody production. Interestingly, stress hormones influence cellular immune pathways affected by microgravity, such as cell proliferation, apoptosis, DNA repair, and T cell activation. These pathways are crucial defense mechanisms that protect the cell from toxins, pathogens, and radiation. Despite the importance of the adrenergic receptor in regulating the immune system, the effect of microgravity on the adrenergic system has been poorly studied. Thus, we elected to investigate the synergistic effects of isoproterenol (a sympathomimetic drug), radiation, and microgravity in nonstimulated immune cells. Peripheral blood mononuclear cells were treated with the sympathomimetic drug isoproterenol, exposed to 0.8 or 2 Gy γ-radiation, and incubated in RWVs. Mixed model regression analyses showed significant synergistic effects on the expression of the β2-adrenergic receptor gene (ADRB2). Radiation alone increased ADRB2 expression, and cells incubated in microgravity had more DNA strand breaks than cells incubated in normal gravity. We observed radiation-induced cytokine production only in microgravity. Prior treatment with isoproterenol clearly prevents most of the microgravity-mediated effects. RWVs may be a useful tool to provide insight into novel regulatory pathways, providing benefit not only to astronauts but also to patients suffering from immune disorders or undergoing radiotherapy

Comparative analysis of chlorambucil-induced DNA lesion formation and repair in a spectrum of different human cell systems

Chlorambucil (CLB) belongs to the class of nitrogen mustards (NMs), which are highly reactive bifunctional alkylating agents and were the first chemotherapeutic agents developed. They form DNA interstrand crosslinks (ICLs), which cause a blockage of DNA strand separation, inhibiting essential processes in DNA metabolism like replication and transcription. In fast replicating cells, e.g., tumor cells, this can induce cell death. The upregulation of ICL repair is thought to be a key factor for the resistance of tumor cells to ICL-inducing cytostatic agents including NMs. To monitor induction and repair of CLB-induced ICLs, we adjusted the automated reversed fluorometric analysis of alkaline DNA unwinding assay (rFADU) for the detection of ICLs in adherent cells. For the detection of monoalkylated DNA bases we established an LC-MS/MS method. We performed a comparative analysis of adduct formation and removal in five human cell lines and in peripheral blood mononuclear cells (PBMCs) after treatment with CLB. Dose-dependent increases in adduct formation were observed, and suitable treatment concentrations were identified for each cell line, which were then used for monitoring the kinetics of adduct formation. We observed significant differences in the repair kinetics of the cell lines tested. For example, in A2780 cells, hTERT immortalized VH10 cells, and in PBMCs a time-dependent repair of the two main monoalkylated DNA-adducts was confirmed. Regarding ICLs, repair was observed in all cell systems except for PBMCs. In conclusion, LC-MS/MS analyses combined with the rFADU technique are powerful tools to study the molecular mechanisms of NM-induced DNA damage and repair. By applying these methods to a spectrum of human cell systems of different origin and transformation status, we obtained insight into the cell-type specific repair of different CLB-induced DNA lesions, which may help identify novel resistance mechanisms of tumors and define molecular targets for therapeutic interventions

The radioprotective effect of procaine and procaine-derived product gerovital H3 in lymphocytes from young and aged individuals

International audienceIonizing radiation induces genomic instability in living organisms, and several studies reported an ageing-dependent radiosensitivity. Chemical compounds, such as scavengers, radioprotectors, and modifiers, contribute to reducing the radiation-associated toxicity. These compounds are often antioxidants, and therefore, in order to be effective, they must be present before or during exposure to radiation. However, not all antioxidants provide radioprotection. In this study, we investigated the effects of procaine and of a procaine-based product Gerovital H3 (GH3) on the formation of endogenous and X-ray-induced DNA strand breaks in peripheral blood mononuclear cells (PBMCs) isolated from young and elderly individuals. Interestingly, GH3 showed the strongest radioprotective effects in PBMCs from young subjects, while procaine reduced the endogenous amount of DNA strand breaks more pronounced in aged individuals. Both procaine and GH3 inhibited lipid peroxidation, but procaine was more effective in inhibiting mitochondria free radicals' generation, while GH3 showed a higher antioxidant action on macrophage-induced low-density lipoprotein oxidation. Our findings provide new insights into the mechanisms underlying the distinct effects of procaine and GH3 on DNA damage