Explicit fiber beam-column elements for impact analysis of structures

The solution of impact problems requires advanced computational techniques to overcome the difficulties associated with large short-duration loads. In this case, the explicit time integration method is typically used, since it provides a stable solution for problems such as the analysis of structures subjected to shock and impact loads. However, most explicit-based finite elements were developed for continuum models such as membrane and solid elements, which renders the problem computationally expensive. On the other hand, the development of fiber-based beam finite elements allows for the simulation of the global structural behavior with very few degrees of freedoms, while accounting for the detailed material nonlinearity along the element length. However, explicit-based fiber beam elements have not been properly formulated, in particular for the case of the emerging force-based beam element. In this paper, two developed fiber plane beam elements that consider an explicit time integration scheme for the solution of the dynamic equation of motion are presented. The first element uses a displacement-based formulation, while the second element uses a force-based formulation. For the latter case, a new algorithm that eliminates the need for iterations at the element level is proposed. The developed elements require the use of a lumped mass matrix and a small time increment to ensure numerical stability. No iterations or convergence checks are required, which renders the problem numerically efficient. The developed explicit fiber beam-column models, particularly the force-based element, represents a simple yet powerful tool for simulating the nonlinear complex effect of impact loads on structures accurately while using very few finite elements. The traditional implicit method of analysis typically fails to provide numerical stable behavior for such short time duration problems. Two correlation studies are presented to highlight the efficiency of the developed elements in modelling impact problems where the strain rate effect is considered in the material models. These examples confirm the accuracy and efficiency of the presented elements

Explicit second-order mixed formulation of reinforced concrete structures under impact loading

Most available research on analysis of reinforced concrete structures under impact loads focuses on using continuum models such as membrane and solid elements, which renders the problem expensive in terms of computational effort. Therefore, a gap exists in the available literature, as no simple finite element has sufficient capabilities to deal with impact and shock problems while considering detailed local parameters. Meanwhile, the objective of this research is to develop several non-linear planar finite element models capable of accurately predicting the response of reinforced concrete structures subjected to impact dynamic loading. A mixed and displacement- based element that use an explicit time integration method and consider large deformations are being developed together with a third force-based first-order element that employs the explicit time integration method. A new algorithm that eliminates the need for iterations at the element level is proposed. The strain rate effect is accounted for in the material constitutive models. The developed explicit fibre beam models, particularly the force-based and mixed elements, represent a simple yet powerful tool for simulating the nonlinear complex effect of impact loads on structures accurately while using very few finite elements. The elements can particularly model fibrous slender reinforced concrete structures and steel concrete panels under impact loading. A simplified procedure is also developed to employ the planar elements in solving three-dimensional problems where the load is applied in the out-of-plane direction. The proposed elements are validated using benchmark experiments available from the literature. The results of the numerical studies proved the newly developed elements are capable of providing accurate and computationally efficient estimates of structural demands under severe impact loading conditions

Eugenia supra-axillaris Essential Oil and Its Nanoemulsion: Chemical Characterization, In Vivo Anti-Inflammatory, Analgesic, and Antipyretic Activities

The use of standard synthetic medications to treat inflammatory illnesses is associated with several negative effects. It has been shown that medicinal plants and their by-products are useful for safely treating inflammation. Herein, the essential oil of Eugenia supra-axillaris (family: Myrtaceae, ESA-EO) was isolated and further chemically characterized by GC-MS, and then, its nanoemulsion (ESA-EO-NE) was prepared. In addition, the anti-inflammation against the carrageenan-induced rats, the analgesic, and antipyretic activities of ESA-EO and ESA-EO-NE were evaluated in rats. Forty-three compounds were identified via GC-MS and categorized as mono- (61.38%) and sesquiterpenes (34.86%). d-limonene (32.82%), α-pinene (24.33%), germacrene-D (4.88%), α-humulene (4.73%), α-cadinol (3.39%), and trans-caryophyllene (3.15%) represented the main components. The administration of ES-EO and ES-EO-NE (50 and 100 mg/kg) demonstrated strong, dose-dependent inflammation inhibition capabilities in the model of rat paw edema, in comparison with both the reference drug and control. Reduced levels of malondialdehyde (MDA), increased levels of glutathione (GSH), and decreased levels of the proinflammatory cytokines (TNF-α), nitrosative (NO), and prostaglandin E2 (PGE2) in paw tissues all contributed to these substantial reductions in inflammation. Moreover, the oral administration of ESA-EO and ESA-EO-NE (50 and 100 mg/kg) exhibited potent analgesic and antipyretic activities in rats. Although the higher dose of ESA-EO and ESA-EO-NE (100 mg/kg) displayed delayed anti-inflammatory activity, they have long-lasting inflammation inhibition with fast onset and long-standing analgesic effects better than reference drugs. Furthermore, the most effective antipyretic efficacy was provided by ESA-EO-NE (100 mg/kg). These results provide insight into the possible therapeutic application of ESA-EO and its nanoemulsion against various inflammatory and painful illnesses as well as hyperthermia ailments

Order 1/N corrections to the time-dependent Hartree approximation for a system of N+1 oscillators

We solve numerically to order 1/N the time evolution of a quantum dynamical system of N oscillators of mass m coupled quadratically to a massless dynamic variable. We use Schwinger's closed time path (CTP) formalism to derive the equations. We compare two methods which differ by terms of order 1/N^2. The first method is a direct perturbation theory in 1/N using the path integral. The second solves exactly the theory defined by the effective action to order 1/N. We compare the results of both methods as a function of N. At N=1, where we expect the expansion to be quite innacurate, we compare our results to an exact numerical solution of the Schroedinger equation. In this case we find that when the two methods disagree they also diverge from the exact answer. We also find at N=1 that the 1/N corrected evolutions track the exact answer for the expectation values much longer than the mean field (N= \infty) result.Comment: 14 pages, 11 figures. Submitted to Phys. Rev.

Synthesis of a New Chelating Iminophosphorane Derivative (Phosphazene) for U(VI) Recovery

A new synthetic chelating N–hydroxy–N–trioctyl iminophosphorane (HTIP) was prepared through the reaction of trioctylphosphine oxide (TOPO) with N–hydroxylamine hydrochloride in the presence of a Lewis acid (AlCl3 ). Specifications for the HTIP chelating ligand were successfully determined using many analytical techniques,13C–NMR,1H–NMR, FTIR, EDX, and GC–MS analyses, which assured a reasonable synthesis of the HTIP ligand. The ability of HTIP to retain U(VI) ions was investigated. The optimum experimental factors, pH value, experimental time, initial U(VI) ion concentration, HTIP dosage, ambient temperature, and eluents, were attained with solvent extraction techniques. The utmost retention capacity of HTIP/CHCl3 was 247.5 mg/g; it was achieved at pH = 3.0, 25◦C, with 30 min of shaking and 0.99 × 10−3 mol/L. From the stoichiometric calculations, approximately 1.5 hydrogen atoms are released during the extraction at pH 3.0, and 4.0 moles of HTIP ligand were responsible for chelation of one mole of uranyl ions. According to kinetic studies, the pseudo–first order model accurately predicted the kinetics of U(VI) extraction by HTIP ligand with a retention power of 245.47 mg/g. The thermodynamic parameters ∆S◦, ∆H◦, and ∆G◦ were also calculated; the extraction process was predicted as an exothermic, spontaneous, and advantageous extraction at low temperatures. As the temperature increased, the value of ∆G◦ increased. The elution of uranium ions from the loaded HTIP/CHCl3 was achieved using 2.0 mol of H2SO4 with a 99.0% efficiency rate. Finally, the extended variables were used to obtain a uranium concentrate (Na2U2O7, Y.C) with a uranium grade of 69.93% and purity of 93.24%. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Princess Nourah Bint Abdulrahman University, PNU: PNURSP2022R13The authors express their gratitude for the support from Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R13), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia

Pulmonary delivery of vancomycin dry powder aerosol to intubated rabbits

TGX-221 is a potent, selective, and cell membrane permeable inhibitor of the PI3K p110β catalytic subunit. Recent studies showed that TGX-221 has anti-proliferative activity against PTEN-deficient tumor cell lines including prostate cancers. The objective of this study was to develop an encapsulation system for parenterally delivering TGX-221 to the target tissue through a prostate-specific membrane aptamer (PSMAa10) with little or no side effects. In this study, PEG-PCL micelles were formulated to encapsulate the drug, and a prodrug strategy was pursued to improve the stability of the carrier system. Fluorescence imaging studies demonstrated that the cellular uptake of both drug and nanoparticles were significantly improved by targeted micelles in a PSMA positive cell line. The area under the plasma concentration time curve of the micelle formulation in nude mice was 2.27-fold greater than the naked drug, and the drug clearance rate was 17.5-fold slower. These findings suggest a novel formulation approach for improving site-specific drug delivery of a molecular-targeted prostate cancer treatment

A Novel Triazole Schiff Base Derivatives for Remediation of Chromium Contamination from Tannery Waste Water

Tannery industries are one of the extensive industrial activities which are the major source of chromium contamination in the environment. Chromium contamination has been an increasing threat to the environment and human health. Therefore, the removal of chromium ions is necessary to save human society. This study is oriented toward the preparation of a new triazole Schiff base derivatives for the remediation of chromium ions. 4,4′-((1E)-1,2-bis ((1H-1,2,4-triazol-3-yl) imino)ethane-1,2-diyl) diphenol was prepared by the interaction between 3-Amino-1H-1,2,4-triazole and 4,4′-Dihydroxybenzil. Then, the produced Schiff base underwent a phosphorylation reaction to produce the adsorbent (TIHP), which confirmed its structure via the different tools FTIR, TGA, 1HNMR, 13CNMR, GC-MS, and Phosphorus-31 nuclear magnetic resonance (31P-NMR). The newly synthesized adsorbent (TIHP) was used to remove chromium oxyanions (Cr(VI)) from an aqueous solution. The batch technique was used to test many controlling factors, including the pH of the working aqueous solution, the amount of adsorbent dose, the initial concentration of Cr(VI), the interaction time, and the temperature. The desorption behaviour of Cr(VI) changes when it is exposed to the suggested foreign ions. The maximum adsorption capacity for Cr(VI) adsorption on the new adsorbent was 307.07 mg/g at room temperature. Freundlich’s isotherm model fits the adsorption isotherms perfectly. The kinetic results were well-constrained by the pseudo-second-order equation. The thermodynamic studies establish that the adsorption type was exothermic and naturally spontaneous. © 2022 by the authors.The APC was funded by “Dunarea de Jos” University of Galati, Romania. The researcher H.A.A is funded by a scholarship under the Joint (Executive Program between Egypt and Russia)

Osjetljiva spektrofotometrijska metoda za određivanje antagonista H2-receptora uz uporabu N-bromsukcinimida i p-aminofenola

A simple, accurate and sensitive spectrophotometric method for determination of H2-receptor antagonists: cimetidine (CIM), famotidine (FAM), nizatidine (NIZ), and ranitidine hydrochloride (RAN) has been full developed and validated The method was based on the reaction of these drugs with NBS and subsequent measurement of the excess N-bromosuccinimide by its reaction with p-aminophenol to give a violet colored product (max at 552 nm). Decrease in the absorption intensity (A) of the colored product, due to the presence of the drug, was correlated with its concentration in the sample solution. Different variables affecting the reaction were carefully studied and optimized. Under optimal conditions, linear relationships with good correlation coefficients (0.9988-0.9998) were found between A values and the corresponding concentrations of the drugs in a concentration range of 830, 622, 625, and 420 g mL1 for CIM, FAM, NIZ, and RAN, respectively. Limits of detection were 1.22, 1.01, 1.08, and 0.74 g mL1 for CIM, FAM, NIZ, and RAN, respectively. The method was validated in terms of accuracy, precision, ruggedness, and robustness; the results were satisfactory. The proposed method was successfully applied to the analysis of the above mentioned drugs in bulk substance and in pharmaceutical dosage forms; percent recoveries ranged from 98.5 0.9 to 102.4 0.8% without interference from the common excipients. The results obtained by the proposed method were comparable with those obtained by the official methods.Razvijena je i validirana ispravna, jednostavna i osjetljiva spektrofotometrijska metoda za određivanje antagonista H2-receptora: cimetidina (CIM), famotidina (FAM), nizatidina (NIZ) i ranitidin hidroklorida (RAN). Metoda se temelji na reakciji tih ljekovitih tvari s N-bromsukcinimidom (NBS). Višak N-bromsukcinimida određuje se nakon reakcije s p-aminofenolom s kojim daje ljubičasti produkt (max pri 552 nm). Smanjenje apsorpcijskog intenziteta (A) obojenog produkta, zbog prisutnosti ljekovite tvari korelirano je s njegovom koncentracijom u otopini uzorka. Proučavane su različite varijable koje utječu na reakciju. Linearno koncentracijsko područje za CIM, FAM, NIZ i RAN, s koeficijentom korelacije od 0,9988 do 0,9998, iznosi 830, 622, 625 odnosno 420 g mL1. Granice detekcije bile su 1,23, 1,02, 1,09 i 0,75 g mL1 za CIM, FAM, NIZ, odnosno RAN. Predložena metoda je uspješno primijenjena za analizu navedenih ljekovitih tvari i ljekovitih pripravaka. Nepreciznost od 0,7 do 1,2% i visoka ispravnost (analitički povrat između 98,5 i 102,4%), bez interferencije uobičajenih pomoćnih tvari, ukazuju na dobru analitičku metodu. Rezultati dobiveni predloženom metodom usporedivi su s rezultatima dobivenim službenom metodom

Long-term results of breast conservation and immediate volume replacement with myocutaneous latissimus dorsi flap

<p>Abstract</p> <p>Background</p> <p>Published long-term outcomes of oncoplastic breast-conserving surgery are scarce and, specifically, aesthetic outcomes assessed with an objective method have not previously been published.</p> <p>Methods</p> <p>A cohort of 41 patients treated with a quadrantectomny and immediate reconstruction using a myocutaneous latissimus dorsi flap were analyzed and their aesthetic outcomes were evaluated objectively by BCCT.core software.</p> <p>Results</p> <p>At the end of a 58-month follow-up from the date of initial diagnosis, one patient (2.4%) developed an ipsilateral recurrence, six patients developed distant metastases and three patients died (7.3%) without ipsilateral recurrence, one of them presenting hepatic metastases at the time of the initial diagnosis. We were able to evaluate aesthetic results in 23 patients, 3 assessed as excellent, 12 good and 8 fair.</p> <p>Conclusion</p> <p>This oncoplastic volume replacement technique obtained a good local control and satisfactory and stable aesthetic results which have maintained unchanged after a long period of time.</p