Quantifier elimination for elementary geometry and elementary affine geometry

We introduce new first‐order languages for the elementary n‐dimensional geometry and elementary n‐dimensional affine geometry (n ≥ 2), based on extending $\mathsf {FO}(\beta ,\equiv )$ and $\mathsf {FO}(\beta )$, respectively, with new function symbols. Here, β stands for the betweenness relation and ≡ for the congruence relation. We show that the associated theories admit effective quantifier elimination.     

A just-in-time three-level integrated manufacturing system for linearly time-varying demand process

This paper considers a just-in-time (JIT) manufacturing system in which a single manufacturer procures raw materials from a single supplier, process them to produce finished products, and then deliver the products to a single-buyer. The customer demand rate is assumed to be linearly decreasing time-varying. In the JIT system, in order to minimize the suppliers as well as the buyers holding costs, the supply of raw materials and the delivery of finished products are made in small quantities. In this case, both the supply and the delivery may require multiple installments for a single production lot. We develop a mathematical model for this problem, propose a simple methodology for solving the model, and illustrate the effectiveness of the method with numerical examples.     

Effect of Chemical Modifications of Fibers on Tensile Properties of Epoxy Hybrid Composites

Treatment of oil palm empty fruit bunch (EFB) and jute fibers is carried out by using 2-hydroxy ethyl acrylate (2-HEA) to increase the interfacial bonding of fibers with the epoxy matrix. Fourier transform-infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were used to measure the change of surface composition of the fibers after treatment. Modified oil palm and jute fibers were used as reinforcements for epoxy matrix to fabricate hybrid composites by the hand lay-up technique. Tensile and morphological properties of hybrid composites were studied, and tensile properties of hybrid composites prepared from chemically treated oil palm/jute fibers were found to be better than those of untreated hybrid composites. SEM micrographs disclose that interfacial bonding between fiber and matrix significantly improved in the hybrid composites. Developed hybrid composites can be exploited as alternative materials for development of automotive and structural components instead of synthetic fiber–reinforced polymer composites.     

Plant-Based Synthesis of Gold Nanoparticles and Theranostic Applications: A Review

Bionanotechnology is a branch of science that has revolutionized modern science and technology. Nanomaterials, especially noble metals, have attracted researchers due to their size and application in different branches of sciences that benefit humanity. Metal nanoparticles can be synthesized using green methods, which are good for the environment, economically viable, and facilitate synthesis. Due to their size and form, gold nanoparticles have become significant. Plant materials are of particular interest in the synthesis and manufacture of theranostic gold nanoparticles (NPs), which have been generated using various materials. On the other hand, chemically produced nanoparticles have several drawbacks in terms of cost, toxicity, and effectiveness. A plant-mediated integration of metallic nanoparticles has been developed in the field of nanotechnology to overcome the drawbacks of traditional synthesis, such as physical and synthetic strategies. Nanomaterials′ tunable features make them sophisticated tools in the biomedical platform, especially for developing new diagnostics and therapeutics for malignancy, neurodegenerative, and other chronic disorders. Therefore, this review outlines the theranostic approach, the different plant materials utilized in theranostic applications, and future directions based on current breakthroughs in these fields.     

Bis­[N,N‐bis(2‐hydroxy­ethyl)­di­thio­carbamato]­di­methyl­tin(IV)

The title compound, [Sn(CH₃)₂(C₅H₁₀NO₂S₂)₂], has crystallographic mirror symmetry (C—Sn—C on mirror plane) and the coordination polyhedron around the Sn atom is a tetrahedron [C—Sn—C 139.3 (2)° and S—Sn—S 82.3 (1)°] distorted towards a skew‐trapezoidal bipyramid owing to an intramolecular Sn?S contact [3.0427 (6) Å]. The mol­ecules are linked into a linear chain by intermolecular O—H?O hydrogen bonds [O?O 2.646 (3) Å].     

The Interaction of a N-Type Four Level Atom with the Electromagnetic Field for a Kerr Medium Induced Intensity-Dependent Coupling

The interaction of a N-type four-level atom with a single field in the presence of an intensity-dependent coupling in a nonlinear Kerr medium is investigated. The exact analytic solution is obtained in the case that the atom and electromagnetic field are initially in a higher excited state and a coherent state, respectively. It is then demonstrated that effects such as nonclassical light generation, degree of entanglement stabilization, Kerr medium nonclassical control, and squeezed light are can be more efficiently implemented within this four-level framework than in many competing procedures. Additionally, inversion, linear entropy, Mandel Q-parameter and normal squeezing dynamics are examined.     

Spectrofluorimetric Assessment of Metoclopramide Hydrochloride Using Terbium Doped in PMMA Matrix Optical Sensor

A new, simple and accurate spectrofluorimetric method for the determination of metoclopramide hydrochloride was developed. The metoclopramide hydrochloride can remarkably enhance the luminescence intensity of the Tb³⁺ ion doped in PMMA matrix at λ_ex = 360 nm in methanol at pH 6.9. The intensity of the emission band at 545 nm of Tb³⁺ ion doped in PMMA matrix is increased due to the energy transfer from metoclopramide hydrochloride to Tb³⁺ in the excited stated. The effect of different parameters, e.g., pH, temperature, Tb³⁺ concentration, foreign ions that control the fluorescence intensity of the produced ion associate was critically investigated. The calibration curve of the emission intensity at 545 nm shows linear response of metoclopramide over a concentration range of 5 × 10⁻⁵–5.0 × 10⁻⁸ M with detection limit of 8.7 × 10⁻¹⁰ M. The method was used successfully for the determination of metoclopramide in pharmaceutical preparations and human serum. The average recovery of 99.48% with standard deviation of 0.32% and 96.98% with standard deviation of 0.4%, of pharmaceutical preparations and human serum respectively, were obtained which compared will with the results obtained from standard LC method of average recovery 99.04% and standard deviation of 0.6% and average recovery of 98.19% with standard deviation of 0.6% of pharmaceutical preparations and human serum, respectively.     

Intensity modulated silver coated glass optical fiber refractive index sensor

Miniature optical fiber sensors with thin films as sensitive elements could open new fields for optical fiber sensor applications. Thin films work as sensitive elements and a transducer to get response and feedback from environments, in which optical fibers act as a signal carrier. A novel Ag coated intensity modulated optical fiber sensor based on refractive index changes using IR and UV-Vis(UV-visible) light sources is proposed. The sensor with an IR light source has higher sensitivity compared to a UV-Vis source. When the refractive index is enhanced to 1.38, the normalized intensity of IR and UV-Vis light diminishes to 0.2 and 0.8, respectively.     

Synthesis of Phthalimidine-3-carboxylate and Benzopyrroloindolizine from N-(Pyrrol-2-yl) Phthalimidine-3-Carboxylate

During the synthesis of the new benzo[a]pyrrolo[2,3-f]indolizine system an improved method for the synthesis of phthalimidine-3-carboxylate is reported.     

Dynamic uniaxial extension of elastomers at constant true strain rate

Elastomers are widely used for damping components in various industrial contexts because of their remarkable dissipative properties: they can bear severe mechanical loading conditions, i.e., high strain rates and large strains. Depending on the strain rate, the mechanical response of these materials can vary from purely rubber-like to glassy. In the intermediate strain rate range (1-100/s), uniaxial extension experiments are classically conducted at constant nominal strain rate. We present here a new experimental methodology to investigate the mechanical response of soft materials at constant true strain rate in the intermediate strain rate range. For this purpose, the displacement imposed on the specimen by the tensile machine is an exponential function of time. A high speed servo-hydraulic machine is used to perform experiments at strain rates ranging from 0.01 to 100/s. A specific specimen is designed in order to achieve a uniform strain field (and thus a uniform stress field). Furthermore, an instrumented aluminium bar is used to measure the applied force; which overcomes the difficulties due to dynamic effects. Simultaneously, a high speed camera enables the measurement of strain in the sample using a point tracking technique. Finally, the method is applied to determine the stress-strain curve of an elastomer for both loading and unloading responses up to a stretch ratio λ = 2.5; the influence of the true strain rate on both stiffness and dissipation of the material is then discussed.