Recent findings in action mechanics showing torques result from rates of variation in impulsive action motivated this more fundamental approach to estimate maximum power from wind turbines. Newton’s third law of equality of action and reaction provides a strictly causal mechanism of wind power from the deflection of wind momentum by twice its angle (θ) of incidence on rotor blades. The lateral reaction needed to conserve wind momentum provides the turning moment for the turbine rotors. This direct approach challenges the current continuum mechanism for generating power from flows of kinetic energy in wind passing through the areas swept by rotating blades. Action mechanics integrates the rates of impulsive wind action on turbine blades as torques (∫mrvdθ/dt ≡ mv2) exerted on rotor surfaces at decreasing radii. Windward torque (Tw) is estimated from rotor dimensions, the angle of wind incidence and radial action of wind impulses on the blade surfaces (also ∫mrvdθ/dt ≡ mv2). A leeward torque (Tb) for back reaction of turbine blades on air mimics drag exerted parallel to the plane of rotation of the blade. Net torque is then converted to potential power (Tw - Tb)Ω by the angular velocity (Ω) of the turbine rotors, a function of tip speed ratio to wind speed. New contributions from action mechanics for managing wind power include larger estimates of its possible magnitude by including vortical energy, much larger than the kinetic energy. Better predictions of limits to wind power can be made, by including control of optimal wind angle and blade length. An analysis of the equivalence of deflected air momentum on turbine blades or air foils for aircraft reveals that even the lifting action on air foils can be explained by the normal reaction to the momentum in an air stream, also deflected by an angle twice that (2θ) of incidence, validating application of action mechanics to airflight. A mechanism for release of vortical field energy from laminar flow of air in anticyclones is predicted in turbulent downstream wakes, possibly assisting achievement of maximum power output by wind farms. Significant heat release by downwind turbulence from vortical energy requires care for their location. Diligence demands that use of windfarms as major sources of renewable energy should minimize any environmental impacts, such as drying of landscapes.
Alcohol drinks, especially wine, have been described since 6,000 B.C. For many years in modern medicine, wine in moderation has been considered healthy for cardiovascular prevention, i.e., recommended by nutrition committees. Some regional guidelines still recommend one to two standard drinks per day. By the very recent (January 2023), World Health Organization and Canadian Guidance on alcohol emphasize that any alcoholic drink is hazardous to the health and the safe amount is zero. The risk starts with every single drop. It was also nicely summarized in the manuscript “Alcohol-dose question and the weakest link in a chemical interplay” (Explor Cardiol. 2023;1:15–25. doi: 10.37349/ec.2023.00003) especially from the standpoint of a researcher in the cardiovascular arena. The newest recommendations are based on observational studies and their meta-analysis, therefore establishing associations, pointing out that alcohol may somewhat prevent cardiovascular diseases and diabetes type 2, but with a significant increase in non-cardiovascular morbidity and mortality, especially cancers. Previous recommendations, therefore, may be obsolete as they were based on studies where abstainers from alcoholic beverages had inherent higher risks. The current controversy with conflicting guidelines for alcoholic beverage consumption in the era of precision medicine may stimulate more fundamental investigations up to genetic ones and find the cause-effect relations. In the era of precision medicine, it may come closer to discovering the causes of cancers and many other diseases, enabling predictions of reactions to alcoholic beverages by each person, not just in the population.
INTRODUCTION Recent information on tortuosity in the prevertebral (V1) segment of the vertebral artery is based on case reports rather than systematic data on its presence, types, diameters, and sex- or left-right differences.
Wireless battery management systems (BMSs) are increasingly being considered for modern applications. The ever-increasing complexity and production costs of BMS modules and wired connections resulted in a necessity for new ideas and approaches. Despite this growing trend, there is a lack of generic solutions focused on battery cells’ sensor readout, where wireless communication allows for a more flexible and cost-efficient sensor installation in battery packs. Many wireless technologies, such as those that use the 2.4GHz frequency band, suffer from interference and other limitations. In this article, we present an alternative approach to communication in BMS that relies on the use of near field communication (NFC) technology for battery sensor readouts. As an answer to the rising concern over the counterfeited battery packs, we consider an authentication schema for battery pack validation. We further consider security measures for the processed and stored BMS status data. To show that a general BMS application can make use of our design, we implement a BMS demonstrator using the targeted components. We further test the demonstrator on the technical and functional level, by also performing evaluation on its performance, energy usage, and a security threat model.
ABSTRACT Background The aim of this study was to provide an overview of age, sex and primary renal disease (PRD) distribution among first kidney transplant recipients across Europe. Method The European Renal Association (ERA) Registry database was used to obtain data on patients aged 20 years or older receiving their first kidney transplant between 2010 and 2019 from 12 European countries. The numbers and percentages of recipients in each age, sex and PRD group were calculated by country, donor type and year. Results In total, 99 543 adults received a first kidney transplant. Overall, 23% of the recipients were 65 years or older, 36% were female, and 21% had glomerulonephritis and 15% diabetes mellitus as PRD. Compared with deceased donor kidney transplant recipients, living donor kidney transplant recipients were less often 65 years or older (13% versus 26%), more often had glomerulonephritis (25% versus 20%) and less often diabetes mellitus (8% versus 17%) as PRD. We found large international differences, which were most prominent for age and PRD and less prominent for sex. Over time, the largest change in recipient characteristics was observed for the percentage of recipients aged 65 years or older, increasing from 18% in 2010 to 28% in 2019 for all countries combined with a similar trend in most countries. Conclusion We observed large differences for age and PRD distribution between recipients of living and deceased donor kidneys and between European countries. Over time, the percentage of older first kidney transplant recipients increased.
The well-being of students and staff directly affects their output and efficiency. This study presents the results of two focus groups conducted in 2022 within a two-phase project led by the Applied Biomedical and Signal Processing Intelligent e-Health Lab, School of Engineering at the University of Warwick, and British Telecom within “The Connected Campus: University of Warwick case study” program. The first phase, by involving staff and students at the University of Warwick, aimed at collecting preliminary information for the subsequent second phase, about the feasibility of the use of Artificial Intelligence and Internet of Things for well-being support on Campus. The main findings of this first phase are interesting technological suggestions from real users. The users helped in the design of the scenarios and in the selection of the key enabling technologies which they considered as the most relevant, useful and acceptable to support and improve well-being on Campus. These results will inform future services to design and implement technologies for monitoring and supporting well-being, such as hybrid, minimal and even intrusive (implantable) solutions. The user-driven co-design of such services, leveraging the use of wearable devices and Artificial Intelligence deployment will increase their acceptability by the users.
- The low recovery of oil (only one-third) is mainly related to the displacement efficiency of porous media, which is influenced by wettability and interfacial tension. Since a large amount of oil deposits, two third of the original oil-in-place is trapped by the capillary forces, and there is a need to recover residual oil by improving oil recovery techniques. Although gas, thermal, microbial, and chemical injection is very popular and highly used techniques, they have some disadvantages. Therefore, tertiary oil recovery techniques, such as the application of nanofluids and nanocomposites, may solve this problem. The selection of appropriate techniques depends on the reservoir and economics. The mobility ratio and the mechanisms for nano-enhanced oil recovery have also been explained. Silica, zinc oxide, titanium dioxide, carbon-based nanoparticles, graphene quantum dots, graphene oxide nanosheets, and anionic surfactants are widely used in enhanced oil recovery research. Nanocomposites were discussed recently prepared, including potassium chloride/silicon dioxide/xanthan and zinc oxide/silicon dioxide/xanthan nanocomposite and others. The reviewed literature experimental data has shown that it is possible to increase the enhanced oil recovery in the 10 to 79% range depending on the applied nanofluid or nanocomposite.
This dataset is composed of cervical spine CT images with annotations related to fractures; it is available at https://www.kaggle.com/competitions/rsna-2022-cervical-spine-fracture-detection/.
Purpose - The primary purpose of this paper is to investigate which internal organizational factors drive digital transformation for business model innovation in small and medium-sized enterprises (SMEs). Design/methodology/approach – The paper builds on a Delphi study from both a South African and Dutch scholarly and industry perspective. The Delphi study uses a questionnaire to query the commonly cited internal organizational factors that drive digital transformation for business model innovation in SMEs in an emerging and a developed economy. Findings – The paper identifies two important internal organizational factors driving digital transformation for business model innovation in SMEs: (a) a renewal of business strategy and (b) a renewal of business culture. It identifies various subfactors within these two internal organizational factors. Originality/value – The study contributes to the current understanding of the internal organizational factors that drive digital transformation for business model innovation in SMEs. Researchers can use these factors and associated subfactors as a basis for future research. To practitioners, the findings provide a guideline on which business activities in SMEs to (re)arrange to enable digital transformation-induced business model innovation.
Antimicrobial resistance is one of the major global health problems and it’s related to the enormous number of human deaths. The occurrence and severity of infections caused by microbial pathogens illustrate the need for the identification and characterization of novel antimicrobial agents of natural origin. This review discusses a well-known coniferous genus Abies Mill. in terms of antimicrobial potential. Data regarding the antibacterial, antifungal, and antiviral properties of Abies species were collected and summarized in this review. It was found that 13 different Abies species are recognized as potential sources of antimicrobial compounds. The most investigated species was A. spectabilis (syn. A. webbiana), followed by A. alba, A. cilicica, A. sibirica, A. nordmanniana, A. numidica, A. koreana, A. balsamea, A. holophylla, and A. concolor. Individual studies on A. firma, A. beshanzuensis, and A. cephalonica were also taken into account. The largest number of analyzed results were related to the antibacterial activity of Abies-derived products, but studies on antifungal, and particularly antiviral capacity were also noted. The most investigated products were essential oils and extracts. The broadest antimicrobial activity was observed for A. cilicica. This study noted that some endemic and endangered Abies species were being used for antimicrobial purposes. In that term, the rationalization of the sampling practices and the implementation of the conservation activities are of great importance. This review represents a comprehensive overview of the current knowledge on the antimicrobial potential of the genus Abies.
Abstract Objectives The shape is commonly used to describe the objects. State-of-the-art algorithms in medical imaging are predominantly diverging from computer vision, where voxel grids, meshes, point clouds, and implicit surface models are used. This is seen from the growing popularity of ShapeNet (51,300 models) and Princeton ModelNet (127,915 models). However, a large collection of anatomical shapes (e.g., bones, organs, vessels) and 3D models of surgical instruments is missing. Methods We present MedShapeNet to translate data-driven vision algorithms to medical applications and to adapt state-of-the-art vision algorithms to medical problems. As a unique feature, we directly model the majority of shapes on the imaging data of real patients. We present use cases in classifying brain tumors, skull reconstructions, multi-class anatomy completion, education, and 3D printing. Results By now, MedShapeNet includes 23 datasets with more than 100,000 shapes that are paired with annotations (ground truth). Our data is freely accessible via a web interface and a Python application programming interface and can be used for discriminative, reconstructive, and variational benchmarks as well as various applications in virtual, augmented, or mixed reality, and 3D printing. Conclusions MedShapeNet contains medical shapes from anatomy and surgical instruments and will continue to collect data for benchmarks and applications. The project page is: https://medshapenet.ikim.nrw/.
Capsella bursa-pastoris (L.) Medik. (known as shepherd's purse) is a plant whose parts are used as medicine in herbal medicine. It is applicable as a medicine in the treatment of all forms of internal bleeding, for the treatment of hemorrhoids, excessive menstruation, but also for the usual stopping of nosebleeds. Through this research, the influence of organic solvents and their aqueous mixtures on the efficiency of polyphenol extraction and antioxidant activity was compared. The inhibition of free radicals was tested by the DPPH method, while the FRAP method was used to test the reduction potential. Analyzes have shown that water is the most effective solvent in the isolation of polyphenols from the aerial parts of shepherd's purse. Mixtures of organic solvents with water also showed high efficiency in the extraction of bioactive components, while the weakest results were obtained for extracts prepared in pure organic solvents.
Groundwater is an essential resource for drinking water, but its contamination with potentially toxic elements and arsenic (As) is a global issue. To evaluate As and its levels in the Coachella Valley, the US Geological Survey (USGS) collected 17 groundwater samples. This study looked into the arsenic distribution, enrichment, hydrogeochemical behavior, and health risks associated with the samples. The comparative analysis between groundwater contamination in Greater Palm Springs and similar regions, could provide valuable insights into regional differences and common challenges. The hydrogeochemical facies showed the dominance of calcium and magnesium-bicarbonate-carbonate, indicating permanent hardness and salt deposits of residual carbonate. The Gibbs plot demonstrated that chemical weathering of rock-forming minerals and evaporation are the primary forces impacting groundwater chemistry. Geochemical modeling revealed saturation for calcite and dolomite, and under-saturation for halite. Principal component analysis identified the potential contributory sources for contamination of groundwater. The carcinogenic and non-carcinogenic potentials of the toxic elements arsenic, cadmium, chromium (VI), and lead were calculated using a human health risk assessment model. For both adults and children, the highest non-carcinogenic mean value was observed for arsenic (8.52 × 10−1), with the lowest for cadmium (1.32 × 10−3). Children had the highest cumulative non-carcinogenic risk from potentially toxic elements. Our research offers crucial baseline data for assessing arsenic in groundwater at the regional level, which is important for health risk reduction and remediation programs. The data show that preventative action must be taken to reduce the potential health risks in the study area from drinking groundwater, particularly for children.
Nema pronađenih rezultata, molimo da izmjenite uslove pretrage i pokušate ponovo!
Ova stranica koristi kolačiće da bi vam pružila najbolje iskustvo
Saznaj više