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Two-photon polymerization with diode lasers emitting ultrashort pulses with high repetition rate
(2020)
In this Letter, we investigate the resolution of two-photon polymerization (2PP) with an amplified mode-locked external cavity diode laser with adjustable pulse length and a high repetition rate. The experimental results are analyzed with a newly developed 2PP model. Even with low pulse peak intensity, the produced structural dimensions are comparable to those generated by traditional 2PP laser sources. Thus, we show that a compact monolithic picosecond laser diode without amplification and with a repetition rate in the GHz regime can also be applied for 2PP. These results show the high application potential of compact mode-locked diode lasers for low-cost and compact 2PP systems.
This paper describes how two-photon polymerization was used to generate biomimetic nanostructures with angle-insensitive coloration inspired by the blue butterflies of Morpho. Less angle dependence was achieved by engineering the structures with a certain degree of disorder, which delimited them from classical photonic crystals. Variations in the processing parameters enabled the color hue to be controlled. In this context, blue, green, yellow, and brown structures were demonstrated. Reflection spectra of the structures were simulated and studied experimentally in a broad range of incident angles. Additionally, a molding technique was performed as a potential scale-up strategy. The application of such biomimetic structures is discussed.
In this manuscript, a new approach in surface plasmon resonance microscopy is presented. The method provides optical real-time detection of single nanoparticles on surfaces. The potential of the method is demonstrated recording spherical dielectric particles as small as 40 nm in diameter and single HIV virus-like particles having diameters of similar to 100 nm both immobilized on functionalized surfaces. The surface plasmon resonance signal in the binding spots was found to be almost linearly proportional to the size of the particles and, therefore, surpasses the intensity of Mie scattering on spherical particle (dependence similar to r(-6)) by orders of magnitude for small objects. The physical reason leading to this strong effect is discussed.
Wind energy plays a major role among renewable
energies. Its expansion is therefore important in order
to achieve the climate targets. Repowering is an
important element in the expansion of wind energy.
On the one hand, it offers a solution for many wind
turbines in Germany that are no longer subsidised due
to their age. On the other hand, modern turbines are
significantly more powerful and enable more efficient
land utilisation. This article provides an overview of
the most important aspects of onshore repowering.
There is a lot to consider when repowering wind turbines.
The legal situation for repowering aims to
be improved through simplified authorisation procedures.
Even though efforts are being made by the
government, there is still room for improvement. The
repowering potential is also dependent on the various
distance regulations to residential buildings in
the federal states. These regulations might also be
improved in the future. Another aspect is the remuneration,
which is now closer to market developments
due to the market premium model. It is also subject
to greater competition as a result of the tendering
process. At the same time, interest rates and turbine
prices have risen, which creates economic challenges
for the operators of future wind farms. Last but not
least, repowering also depends on public acceptance.
This is also to be regulated by law in the future.
Healthy Moms, Healthy Babies and Hopeful Hearts. Geburtshilfe am Rande eines philippinischen Slums
(2012)
Phenanthroline chromophore as efficient antenna for Tb3+ green luminescence: A theoretical study
(2021)
Cathode ray-luminescent phosphor and method for the preparation thereof, <b>United States Patent</b>
(2000)
Diese Arbeit kann in der Bibliothek für Architektur, Design und Kunst (Leonardocampus 10) eingesehen werden.
A research study on 18 start-up hubs in Europe. Affiliation and Publisher: PricewaterhouseCoopers
(2019)
Diese Arbeit kann in der Bibliothek für Architektur, Design und Kunst (Leonardocampus 10) eingesehen werden.
Diese Arbeit kann in der Bibliothek für Architektur, Design und Kunst (Leonardocampus 10) eingesehen werden.
The concern for the environment among European consumers is growing and in the future the need for sustainable shopping is expected to increase. Through transparent on-packaging communication with consumers, organic producers have the opportunity to show attributes of organic production system and build a strong market position. The aim of the study was to analyse voluntary packaging information on organic milk from four European markets in the context of organic food quality, i.e., Germany, the Netherlands, Italy and Poland. More specifically, the textual content of 106 organic milk packages was analysed and voluntary information on each package was categorized according to process- and product-related organic milk attributes. The assortment and content of voluntary packaging information varied across the four countries. The largest number of products was found on the German market (37) and the smallest on the Polish market (14). Dutch milk had the greatest amount of voluntary information on animal welfare, product locality, environmental protection, quality confirmation, naturalness and nutritional value. German milk had the most information on enjoyment and conditions of processing, while the Italian milk on the social perspective. The products available on the Polish market had the least voluntary information. Pasteurized organic milk had noticeably more information about organic quality attributes than micro filtrated and UHT milk.
The use of hydraulic fracturing (HF) to extract oil and natural gas has increased, along with intensive discussions on the associated risks to human health. Three technical processes should be differentiated when evaluating human health risks, namely (1) drilling of the borehole, (2) hydraulic stimulation, and (3) gas or oil production. During the drilling phase, emissions such as NOx, NMVOCs (non-methane volatile organic compounds) as precursors for tropospheric ozone formation, and SOx have been shown to be higher compared to the subsequent phases. In relation to hydraulic stimulation, the toxicity of frac fluids is of relevance. More than 1100 compounds have been identified as components. A trend is to use fewer, less hazardous and more biodegradable substances; however, the use of hydrocarbons, such as kerosene and diesel, is still allowed
in the USA. Methane in drinking water is of low toxicological relevance but may indicate inadequate integrity of the gas well.
There is a great concern regarding the contamination of ground- and surface water during the production phase. Water that flows to the surface from oil and gas wells, so-called ‘produced water’, represents a mixture of flow-back, the injected frac fluid returning to the surface, and the reservoir water present in natural oil and gas deposits. Among numerous hazardous compounds, produced water may contain bromide, arsenic, strontium, mercury, barium, radioactive isotopes and organic compounds, particularly benzene, toluene, ethylbenzene and xylenes (BTEX). The sewage outflow, even from specialized treatment plants, may still contain critical concentrations of barium, strontium and arsenic. Evidence suggests that the quality of groundwater and surface water may be compromised by disposal of produced water. Particularly critical is the use of produced water for watering of agricultural areas, where persistent compounds may accumulate. Air contamination can occur as a result of several HF-associated activities. In addition to BTEX, 20 HF-associated air contaminants are group 1A or 1B carcinogens according to the IARC. In the U.S., oil and gas production (including conventional production) represents the second largest source of anthropogenic methane emissions. High-quality epidemiological studies are required, especially in light of recent observations of an association between childhood leukemia and multiple myeloma in the neighborhood of oil and gas production sites. In conclusion, (1) strong evidence supports the conclusion that frac fluids can lead to local environmental contamination; (2) while changes in the chemical composition of soil, water and air are likely to occur, the increased levels are still often below threshold values for safety; (3) point source pollution due to poor maintenance of wells and pipelines can be monitored and remedied; (4) risk assessment should be based on both hazard and exposure evaluation; (5) while the concentrations of frac fluid chemicals are low, some are known carcinogens; therefore, thorough, well-designed studies are needed to assess the risk to human health with high certainty; (6) HF can represent a health risk via long-lasting contamination of soil and water, when strict safety measures are not rigorously applied.
Effects on Risk Taking Resulting from Limiting the Value at Risk or the Lower Partial Moment One
(1997)
On the Compatibility of Value at Risk, Other Risk Concepts, and Expected Utility Maximization
(1996)
The spatially varying intensity in a standing wave resonator leads to spatial hole burning in the gain medium of a laser. The spatial hole burning changes the gain of different longitudinal modes and can thus determine the optical spectrum of the laser. We simulate this longitudinal mode competition in standing wave resonators of thin-disk lasers. The resulting optical spectra of the laser are compared to measured optical spectra. We examine two types of resonators: I-resonators and V-resonators with different angles of incidence. In V-resonators, the non-normal incidence of the laser beam on the disk lifts the degeneracy of the polarization. Experiments show that the slight gain advantage for the p-polarization does not lead to polarized emission. For both types of resonators, the measured spectra are in good agreement with the simulated ones. The simulations allow to study the influence of spectral intra-cavity losses on the optical spectrum of a thin-disk laser.
Despite their important role in our energy system, common wind turbines have some disadvantages. Mainly, those disadvantages are connected to the intermediate conversion of wind energy in rotational energy. The resulting effects include maintenance costs and social acceptance problems. There are different technological approaches, that convert wind energy to electrical energy without its conversion to kinetic energy. As one of those technologies, the electrostatic wind energy conversion is to be discussed in this article. For this discussion, the historical development of this technology is presented. There are three important projects which will be presented to explain the technology and its different technological approaches. Those projects are the WPG, the EWICON and the SWET. Furthermore the results of those different experimental projects are collected and analyzed. On the basis of this analysis it is discussed, whether or not the electrostatic wind energy conversion could be of importance in a future energy system. Therefore the technology is set in relation to modern wind turbines. Also, important factors that influence the efficiency and energy output of those systems are outlined for further research. Due to different technological approaches a suggestion is made for the most promising system setting.
This review provides a survey of studies investigating physical activity and exercise interventions in patients during tumor treatment and survivors of childhood cancer. PubMed and Medline databases were searched using relevant terms. References of selected papers were tracked. A total of 28 studies could be identified. Seventeen studies investigated physical activity, 11 studies determined the effect of activity enhancing interventions during and after therapy. Even though most studies showed limitations and results were not consistent, considerably reduced physical activity is highly probable in patients during and after therapy. Studies on interventions provided promising results and revealed challenges to be faced. Pediatr Blood Cancer
Purpose
The diagnosis of a malignant bone tumor in the lower limb is a risk factor for physical disability, limiting physical performance. Walking ability especially, which is essential for most activities of daily living, is limited in those patients. In the present study, the extent of limitations during the course of treatment was investigated to determine when the assessment of functional parameters is meaningful in those patients.
Methods
In the present study, activity levels were determined in 20 patients with a malignant bone tumor in the lower limb who received endoprosthetic replacement of the affected bone and in 20 healthy individuals. A uniaxial accelerometer was used to investigate patients at five different time points after surgery.
Results
Patients performed significantly less amounts and intensities of activity than control individuals at all measurements. Significant increases in the volume of activity were observed after cessation of treatment. However, the intensity of activity only showed minor increases. Patients experiencing complications of surgery revealed greater restriction than those without even 18 months after surgery.
Conclusions
After cessation of treatment for their disease, patients recovered markedly and showed great improvements in physical activity. However, some limitations appeared to persist. Comparisons with patients with longer follow-up revealed that meaningful functional assessment does not make sense within the first 12 months after surgery. More research is needed to show if longer follow-up periods reveal further improvements. Based on such information, it should be more promising to develop individually tailored activity recommendations and intervention programs.
Background
The diagnosis of cancer bears severe implications for pediatric patients. One immense restriction consists in a reduced level of activity due to different factors. Physical activity affects various aspects of development and can be regarded as an essential part of a child's life. In the present study physical activity in patients undergoing cancer therapy was quantified in order to determine the extent of the restriction and to provide baseline information for the assessment of possible interventions.
Procedure
Physical activity in 80 patients and 45 healthy children matched for age and gender was measured using the StepWatch 3™ Activity Monitor (SAM, OrthoCare Innovations).
Results
Pediatric cancer patients, at 2,787 gait cycles (gcs) per day, were significantly less active than their healthy counterparts (8,096 gcs). Patients were significantly more active at home than during inpatient stays (3,185 gcs compared to 1,830 gcs), and patients with bone tumors were less active than those with leukemia regarding both, the amount (1,849 gcs vs. 2,992 gcs) and the intensity of activity.
Conclusion
The present study quantified an often observed but so far hardly assessable problem. Activity in cancer patients is considerably reduced and patients with bone tumors are at increased risk from the detrimental effects of prolonged inactivity. Both our findings and the accepted fact that activity is an essential element of child development confirm the need for interventions tailored to a patient's needs and abilities during the course of treatment.
Background
Degenerative musculoskeletal disorders are among the most frequent diseases occurring in adulthood, often impairing patients' functional mobility and physical activity. The aim of the present study was to investigate and compare the impact of three frequent degenerative musculoskeletal disorders -- knee osteoarthritis (knee OA), hip osteoarthritis (hip OA) and lumbar spinal stenosis (LSS) -- on patients' walking ability.
Methods
The study included 120 participants, with 30 in each patient group and 30 healthy control individuals. A uniaxial accelerometer, the StepWatch™ Activity Monitor (Orthocare Innovations, Seattle, Washington, USA), was used to determine the volume (number of gait cycles per day) and intensity (gait cycles per minute) of walking ability. Non-parametric testing was used for all statistical analyses.
Results
Both the volume and the intensity of walking ability were significantly lower among the patients in comparison with the healthy control individuals (p < 0.001). Patients with LSS spent 0.4 (IQR 2.8) min/day doing moderately intense walking (>50 gait cycles/min), which was significantly lower in comparison with patients with knee and hip OA at 2.5 (IQR 4.4) and 3.4 (IQR 16.1) min/day, respectively (p < 0.001). No correlations between demographic or anthropometric data and walking ability were found. No technical problems or measuring errors occurred with any of the measurements.
Conclusions
Patients with degenerative musculoskeletal disorders suffer limitations in their walking ability. Objective assessment of walking ability appeared to be an easy and feasible tool for measuring such limitations as it provides baseline data and objective information that are more precise than the patients' own subjective estimates. In everyday practice, objective activity assessment can provide feedback for clinicians regarding patients' performance during everyday life and the extent to which this confirms the results of clinical investigations. The method can also be used as a way of encouraging patients to develop a more active lifestyle.
Background: Modern healthcare devices can be connected to computer networks and many western healthcareinstitutions run those devices in networks. At the same time, cyber attacks are on the rise and there is evidence thatcybercriminals do not spare critical infrastructure such as major hospitals, even if they endanger patients. Intuitively,the more and closer connected healthcare devices are to public networks, the higher the risk of getting attacked.
Methods: To asses the current connectivity status of healthcare devices, we surveyed the field of German hospitalsand especially University Medical Center UMCs.
Results: The results show a strong correlation between the networking degree and the number of medical devices.The average number of medical devices is 25.150, with a median of networked medical devices of 3.600. Actual keyusers of networked medical devices are the departments Radiology, Intensive Care, Radio-Oncology RO, NuclearMedicine NUC, and Anaesthesiology in the group of UMCs. In the next five years, the usage of networked medicaldevices will increase significantly in the departments of Surgery, Intensive Care, and Radiology. We detected a strongcorrelation between the degree of connectivity and the likelihood of being attacked.The survey answers regarding the cyber security status reveal a lack of security basics in some of the inquiredhospitals. We did discover successful attacks in hospitals with separated or subsidiary departments. A fusion ofcompetencies on an organizational level facilitates the right behavior here. Most hospitals rated themselvespredominantly positively in the self-assessment but also stated the usefulness of IT security insurance.Conclusions:Concluding our results, hospitals are already facing the consequences of omitted measures within theirgrowing pool of medical devices. Continuously relying on historically grown structures without adaption and trustingmanufactures to solve vectors is a critical behavior that could seriously endanger patients.
Technical and organizational steps are necessary to mitigate cyber threats and reduce risks. Human behavior is the last line of defense for many hospitals and is considered as equally important as technical security. Medical staff must be properly trained to perform such procedures. This paper presents the first qualitative, interdisciplinary research on how members of an intermediate care unit react to a cyberattack against their patient monitoring equipment. We conducted a simulation in a hospital training environment with 20 intensive care nurses. By the end of the experiment, 12 of the 20 participants realized the monitors’ incorrect behavior. We present a qualitative behavior analysis of high performing participants (HPP) and low performing participants (LPP). The HPP showed fewer signs of stress, were easier on their colleagues, and used analog systems more often than the LPP. With 40% of our participants not recognizing the attack, we see room for improvements through the use of proper tools and provision of adequate training to prepare staff for potential attacks in the future.
Association between cardiovascular risk factors and erectile dysfunction – a population-based study
(2006)
Abstract This study extends previous research evaluating the association between the CHIP intervention, change in body weight, and change in psychological health. A randomized controlled health intervention study lasting 4 wk. was used with 348 participants from metropolitan Rockford, Illinois; ages ranged from 24 to 81 yr. Participants were assessed at baseline, 6 wk., and 6 mo. The Beck Depression Inventory (BDI) and three selected psychosocial measures from the SF-36 Health Survey were used. Significantly greater decreases in Body Mass Index (BMI) occurred after 6 wk. and 6 mo. follow-up for the intervention group compared with the control group, with greater decreases for participants in the overweight and obese categories. Significantly greater improvements were observed in BDI scores, role-emotional and social functioning, and mental health throughout follow-up for the intervention group. The greater the decrease in BMI through 6 wk., the better the chance of improved BDI score, role-emotional score, social functioning score, and mental health score, with odds ratios of 1.3 to 1.9. Similar results occurred through 6 mo., except the mental health variable became nonsignificant. These results indicate that the CHIP intervention significantly improved psychological health for at least six months afterwards, in part through its influence on lowering BMI.
In-depth analysis of customer journeys to broaden the understanding of customer behaviors and expectations in order to improve the customer experience is considered highly relevant in modern business practices. Recent studies predominantly focus on retrospective analysis of customer data, whereas more forward-directed concepts, namely predictions, are rarely addressed. Additionally, the integration of robotic process automation (RPA) to potentially increase the efficiency of customer journey analysis is not discussed in the current field of research. To fill this research gap, this paper introduces “customer journey mining”. Process mining techniques are applied to leverage digital customer data for accurate prediction of customer movements through individual journeys, creating valuable insights for improving the customer experience. Striving for improved efficiency, the potential interplay of RPA and customer journey mining is examined accordingly. The research methodology followed is based on a design science research process. An initially defined customer journey mining artifact is operationalized through an illustrative case study. This operationalization is achieved by analyzing a log file of an online travel agency functioning as an orientation for researchers and practitioners while also evaluating the initially defined framework. The data is used to train seven distinct prediction models to forecast the touchpoint a customer is most likely to visit next. Gradient-boosted trees yield the highest prediction accuracy with 43.1%. The findings further indicate technical suitability for RPA implementation, while financial viability is unlikely.
The former bull market has led to developments in the online brokerage industry such as over-capacity, profit-margin pressure, high fixed costs and unprofitable country expansion in the current bear market environment. In order to manage this situation, tactical measures like cost containment programs and closing of international brokerages have been applied. More strategic approaches like order flow consolidation by brokerage franchises, integrated online & branch brokerages and multinational electronic brokerages are valid alternative responses to these developments. This article outlines the Multi-National Electronic Brokerage approach from a strategic, functional, operational and technical perspective.
Camera based path planning for low quantity - high variant manufacturing with industrial robots
(2019)
The acquisition costs for industrial robots have been steadily decreasing in past years. Nevertheless, they still face significant drawbacks in the required effort for the preparation of complex robot tasks which causes these systems to be rarely present so far in small and medium-sized enterprises (SME) that focus mainly on small volume, high variant manufacturing. In this paper, we propose a camera-based path planning framework that allows the fast preparation and execution of robot tasks in dynamic environments which leads to less planning overhead, fast program generation and reduced cost and hence overcomes the major impediments for the usage of industrial robots for automation in SMEs with focus on low volume and high variant manufacturing. The framework resolves existing problems in different steps. The exact position and orientation of the workpiece are determined from a 3D environment model scanned by an optical sensor. The so retrieved information is used to plan a collision-free path that meets the boundary conditions of the specific robot task. Experiments show the potential and effectiveness of the the framework presented here by evaluating a case study.
Biohydrogen production via dark fermentation with pig manure and glucose using pH-dependent feeding
(2020)