712 research outputs found

    Design of a deep learning based nonlinear aerodynamic surrogate model for UAVs

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    In this paper, we present a deep learning based surrogate model to determine non-linear aerodynamic characteristics of UAVs. The main advantage of this model is that it can predict the aerodynamic properties of the configurations very quickly by using only geometric configuration parameters without the need for any special input data or pre-process phase. This provides a crucial and explicit design and synthesis tool for mini and small UAVs. To achieve this goal, a large data set, which includes thousands of wing-tail configurations geometry parameters and performance coefficients, was generated using the previously developed and computationally very efficient non-linear lifting line method. This data is used for training the artificial neural network model. The preliminary results show that the neural network model has generalization capability. The aerodynamic model predictions show almost 1-1 coincidence with the numerical data even for configurations with different 2D profiles that are not used in model training. Specifically, the results of test cases are found to capture both the linear and non-linear region of the lift curves, by predicting the maximum lift coefficient, the stall angle of attack, and the characteristics of post-stall region correctly. Similarly, total drag and pitching moment coefficients are predicted successfully. The developed methodology provides the basis for bidirectional design optimization and offers insight for an inverse tool that can calculate geometry parameters for a given design condition

    The use of sesame oil in sea bream feeds and its effects on growth and body chemical composition

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    As fish oil availability declines worldwide and its price rises, there is a growing need to engage in scientific investigations into alternative oil sources for incorporation into fish feeds. This study aimed to determine the effects of dietary sesame oil on the growth performance, feed utilization, and nutritional composition of sea bream (*Sparus aurata*). Twenty-five individual fish (initial mean weight: 32.38±0.27 g) were placed in each tank in triplicate. Four experimental fish meal-based (iso-proteic 49% and iso-lipidic 20%) diets were formulated; the control (C) group contains 100% of fish oil (FO) and varying amounts (20, 40, 60%) of sesame oil (SO). During the 75-day experiment, the fish were fed 3 times a day, and the mean ambient temperature and dissolved oxygen values were measured as 22.5±0.5°C and 6.8±0.3 mg/L, respectively. At the beginning of the experiment, 20 fish were sampled to determine their nutrient composition and somatic indexes. In the end, 4 fish were collected for the same procedures and 4 for each tank's muscle and liver fatty acid compositions. At the end of the study, the S60 group exhibited the lowest final weight (FW) and feed utilization parameters. On the other hand, there were no statistical differences between FO, SO20, and SO40 in terms of FW. In addition, the SO40 group had the best feed conversion ratio (FCR) among the groups (P\<0.05). The whole-body lipid compositions of the groups were different. The highest lipid level was found in SO40 with 15.83±0.36%. Muscle and liver fatty acid composition was significantly affected by the fatty acid profile of experimental feeds. While total ω-6 fatty acids were higher in the SO groups than in group C, total ω-3 fatty acids were higher in the C group compared to the SO groups (P\<0.05). The ω-3/ω-6 ratios in the SO20 and SO40 groups showed similarity, while the highest ratio was observed in the control group (P\<0.05). As a result, according to data obtained from our study, it is predicted that 40% SO could be added to sea bream feed instead of FO in terms of growth performance, feed utilization, and nutritional composition

    Kalvin’in Enstitüleri’nde Negatif Tecrübe ve Bunun Sistematik Sonuçları

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    In this study, the place and importance of the term “negative experience” in Calvin’s well-known book “the Institutes of the Christian Religion” is examined as well as the shifts in Calvin’s theology as a result of his explanations to this issue. The effects of negative experience on people’s belief and the types of belief are also pointed out and every aspect of the issue is discussed within Calvin’s Institutes, as a result important question about Calvin’s theology occurred. In the end it seemed that Calvin has given different answers that are contrary to each other to the same questions throughout his life span or his book. It is also detected that the issue of negative experience caused some contradictory explanations of the missions of the Persons in Holy Trinity.Bu makalede John Calvin’in en önemli eseri olan Hristiyan Dininin Enstitüleri temel alınarak Calvin’in teolojisinde negatif tecrübenin yeri ve buna verdiği cevaplar çerçevesinde teolojisinin sisteminde meydana gelen değişimler ele alınmaya çalışılmıştır. İnsanların hayatları süresince yaşadıkları negatif tecrübelerin imanları üzerindeki etkisi ve imanın çeşitleri üzerine de değinilmiş olup, işaret edilen her nokta Calvin’in Enstitüler kitabından alıntılarla desteklenmiş ve ciddi soru işaretleri oluşturmuştur. Sonuç olarak Calvin’in aynı sorunlara hayatının farklı dönemlerinde ya da kitabının farklı bölümlerinde birbiriyle çelişir gibi görünen açıklamalar yaptığı görülmüştür. Negatif tecrübenin teslis inancı ve üçlemedeki kişilerin görevleriyle ilgili bazı çelişkili açıklamalara sebebiyet verdiği de tespit edilmiştir

    Optimum Electrical Resistivity Tomography (OERT) approach using combination of different arrays in archaeological investigations

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    In this study, the optimum electrical resistivity tomography (OERT) concept was analyzed by combining different electrode arrays in terms of sensitivity in archaeological cases. More than a hundred electrode arrays were classified by Szalai & Szarka (2008), investigating the superposition, focusing and linearity problem. Also, Dahlin & Zhou (2004) compared images resulting from various configurations. However, the difficulties posed by apparent resistivity due to different characteristics of ..

    Subletalni učinci 2,4-diklorofenoksi octene kiseline (2,4-D) na slatkovodnog uskoškarog raka (Astacus leptodactylus Eschscholtz, 1823)

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    2,4-D is a widely used phenoxy herbicide, potentially toxic to humans and biota. The objective of the present study was to reveal short term sublethal effects of 2,4-D on narrow-clawed freshwater crayfish (Astacus leptodactylus Eschscholtz, 1823), based on histology, total haemocyte counts, selected haemolymph parameters, and oxidative stress parameters. In the laboratory conditions crayfish specimens were exposed to 9 mg L-1 of 2,4-D for one week. Experiments were conducted under semi-static conditions in 20 L-capacity aquaria where 10 freshwater crayfish were stocked per aquarium. Exposure (experimental) and control groups were used and the experiments were repeated two times. No mortality and behavioural changes were recorded during the experiments. Total haemocyte counts decreased significantly, while haemolymph glucose levels increased (P<0.05), when compared to the control group. Haemolymph levels of calcium, chloride, sodium, potassium, magnesium, total protein, and lactate did not change. Exposure resulted with increased levels of malondialdehyde (MDA) only in hepatopancreas. However, results of gill FOX assay showed a significant decrease in oxidative stress parameters (P<0.05). MDA levels of gill and abdominal muscle tissues and FOX levels of hepatopancreas and abdominal muscle tissues did not change when compared to the control group. Significant histopathological alterations were observed both in hepatopancreas (multifocal deformations in tubule lumen) and gill tissue (melanisation of gill lamella). Exposure of crayfish even to a sublethal concentration of 2,4-D alters histopathology and lipid peroxidation due to stress. Biomarkers studied here seem to be useful for the assessment of adverse/toxic effects of pesticides on non-target, indicator aquatic organisms.2,4-D je fenoksi herbicid koji se upotrebljava diljem svijeta, a potencijalno je toksičan za ljude i biotu. Cilj ovoga istraživanja bio je ispitati kratkoročne subletalne učinke herbicida 2,4-D na slatkovodnog uskoškarog raka (Astacus leptodactylus Eschscholtz, 1823) proučavanjem histoloških promjena, ukupnog broja hemocita, odabranih hemolitičkih parametara i parametara oksidacijskoga stresa. Jedinke slatkovodnog raka izložene su u laboratorijskim uvjetima koncentraciji od 9 mg L-1 herbicida 2,4-D tijekom sedam dana. Eksperimenti su izvedeni u polustatičkim uvjetima u 20-litarskim akvarijima. U svakom akvariju držano je 10 jedinki rakova, podijeljenih u skupinu koja je bila izložena herbicidu i u kontrolnu skupinu, a eksperiment je ponovljen tri puta. Tijekom eksperimenata nisu zabilježene nikakve promjene u stopi smrtnosti ili u ponašanju životinja. Ukupan se broj hemocita značajno smanjio, a razine glukoze u hemolimfi povećale (P<0,05) u usporedbi s kontrolnom skupinom. Razine kalcija, klorida, kalija, magnezija, ukupnog proteina i laktata u hemolimfi nisu se promijenile. Izlaganje herbicidu povisilo je razine malondialdehida (MDA) u hepatopankreasu. Međutim, rezultati FOX-testa na škrgama pokazali su značajno smanjenje parametara oksidacijskoga stresa (P<0,05), za razliku od razina MDA izmjerenih FOX-testom u škrgama i abdominalnom mišićnom tkivu te u hepatopankreasu, koje se nisu promijenile. Uočene su značajne histopatološke promjene u tkivu hepatopankreasa (multifokalne deformacije tubularnog lumena) i škrga (melanizacija škržnih listića). Izlaganje rakova subletalnoj koncentraciji herbicida 2,4-D izazvalo je histopatološke promjene te potaknulo lipidnu peroksidaciju zbog stresa. Čini se da su biomarkeri koji su promatrani u ovom ispitivanju korisni za procjenu neželjenih učinaka pesticida na neciljne vodene indikatorske organizme

    A high-fat high-sugar diet predicts poorer hippocampal-related memory and a reduced ability to suppress wanting under satiety

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    Animal data indicate that greater intake of fats and sugars prevalent in a Western diet impairs hippocampal memory and tests of behavioral inhibition known to be related to hippocampal function (e.g., feature negative discrimination tasks). It has been argued that such high fat high sugar diets (HFS) impair the hippocampus, which then becomes less sensitive to modulation by physiological state. Thus retrieval of motivationally salient memories (e.g., when seeing or smelling food) occurs irrespective of state. Here we examine whether evidence of similar effects can be observed in humans using a correlational design. Healthy human participants (N = 94), who varied in their habitual consumption of a HFS diet, completed the verbal paired associate (VPA) test, a known hippocampal-dependent process, as well as liking and wanting ratings of palatable snack foods, assessed both hungry and sated. Greater intake of a HFS diet was significantly associated with a slower VPA learning rate, as predicted. Importantly, for those who regularly consumed a HFS diet, while reductions in liking and wanting occurred between hungry and sated states, the reduction in wanting was far smaller relative to liking. The latter effect was strongly related to VPA learning rate, suggestive of hippocampal mediation. In agreement with the animal literature, human subjects with a greater intake of a HFS diet show deficits in hippocampal-dependent learning and memory, and their desire to consume palatable food is less affected by physiological state – a process we suggest that is also hippocampal related

    Evaluation of e148q and concomitant aa amyloidosis in patients with familial mediterranean fever

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    The aim of the study was to compare the clinical phenotype of patients with familial Mediterranean fever (FMF)-related AA amyloidosis, according to the age of FMF diagnosis and E148Q genotype. Patients with biopsy-confirmed FMF-related AA amyloidosis were included in the study. Tel-Hashomer criteria were applied in the diagnosis of FMF. All patients had detailed baseline assessment of clinical features, renal functions, genetic testing, histopathological diagnosis of amyloidosis, and treatment received. Multiple comparisons were performed according to the age of diagnosis, disease phenotype, mutation, and mortality. Our study included 169 patients with a diagnosis of AA amyloidosis. There were 101 patients diagnosed with FMF \u3c 18 years of age and 68 patients diagnosed who were ≥18 years of age. The three most common clinical manifestations were fever (84.6%), abdominal pain (71.6%), and arthritis (66.9%). The most common allele among FMF patients was M694V (60.6%), followed by E148Q (21.4%), and M680I (10.3%). The most frequent genotypes were M694V/M694V (45.0%), M694V/E148Q (14.8%), and E148Q/E148Q (11.2%) among 169 patients in our cohort. During the follow-up period, 15 patients (10 male, 5 female) died, of whom 14 had M694V homozygous genotype and one was homozygous for E148Q. Clinicians should be aware of patients with homozygous E148Q genotype for close monitoring and further evaluation. The possible relationship between E148Q and AA amyloidosis needs to be confirmed in other ethnicities

    Formation and optogenetic control of engineered 3D skeletal muscle bioactuators

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    Densely arrayed skeletal myotubes are activated individually and as a group using precise optical stimulation with high spatiotemporal resolution. Skeletal muscle myoblasts are genetically encoded to express a light-activated cation channel, Channelrhodopsin-2, which allows for spatiotemporal coordination of a multitude of skeletal myotubes that contract in response to pulsed blue light. Furthermore, ensembles of mature, functional 3D muscle microtissues have been formed from the optogenetically encoded myoblasts using a high-throughput device. The device, called “skeletal muscle on a chip”, not only provides the myoblasts with controlled stress and constraints necessary for muscle alignment, fusion and maturation, but also facilitates the measurement of forces and characterization of the muscle tissue. We measured the specific static and dynamic stresses generated by the microtissues and characterized the morphology and alignment of the myotubes within the constructs. The device allows testing of the effect of a wide range of parameters (cell source, matrix composition, microtissue geometry, auxotonic load, growth factors and exercise) on the maturation, structure and function of the engineered muscle tissues in a combinatorial manner. Our studies integrate tools from optogenetics and microelectromechanical systems (MEMS) technology with skeletal muscle tissue engineering to open up opportunities to generate soft robots actuated by a multitude of spatiotemporally coordinated 3D skeletal muscle microtissues.National Science Foundation (U.S.) (Science and Technology Center—Emergent Behaviors of Integrated Cellular Systems (EBICS) grant No. CBET-0939511)National Institutes of Health (U.S.) (EB00262)National Science Foundation (U.S.) (GM74048)National Science Foundation (U.S.) (HL90747)National Institute for Biomedical Imaging and Bioengineering (U.S.) (RESBIO, Integrapted Technologies for Polymeric Biomaterial)University of Pennsylvania. Center for Engineering Cells and RegenerationSingapore-MIT Alliance for Research and Technolog

    Generalizability of empirical correlations for predicting higher heating values of biomass

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    Designing efficient biomass energy systems requires a thorough understanding of the physicochemical, thermodynamic, and physical properties of biomass. One crucial parameter in assessing biomass energy potential is the higher heating value (HHV), which quantifies its energy content. Conventionally, HHV is determined through bomb calorimetry, but this method is limited by factors such as time, accessibility, and cost. To overcome these limitations, researchers have proposed a diverse range of empirical correlations and machine-learning approaches to predict the HHV of biomass based on proximate and ultimate analysis results. The novelty of this research is to explore the universal applicability of the developed empirical correlations for predicting the Higher Heating Value (HHV) of biomass. To identify the best empirical correlations, nearly 400 different biomass feedstocks were comprehensively tested with 45 different empirical correlations developed to use ultimate analysis (21 different empirical correlations), proximate analysis (16 different empirical correlations) and combined ultimate-proximate analysis (8 different empirical correlations) data of these biomass feedstocks. A quantitative and statistical analysis was conducted to assess the performance of these empirical correlations and their applicability to diverse biomass types. The results demonstrated that the empirical correlations utilizing ultimate analysis data provided more accurate predictions of HHV compared to those based on proximate analysis or combined data. Two specific empirical correlations including coefficients for each element (C, H, N) and their interactions (C*H) demonstrate the best HHV prediction with the lowest MAE (~0.49), RMSE (~0.64), and MAPE (~2.70%). Furthermore, some other empirical correlations with carbon content being the major determinant also provide good HHV prediction from a statistical point of view; MAE (~0.5–0.8), RMSE (~0.6–0.9), and MAPE (~2.8–3.8%)
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