MR and CT techniques

Magnetic resonance imaging (MRI) and computed tomography (CT) are routinely used in female pelvis imaging. MRI is primarily useful for locoregional characterization of benign and malignant diseases. CT is less accurate in locoregional evaluation, but remains useful in the follow-up of treated gynecological malignancies, as well as in the setting of emergency and in the guidance of biopsies. Although transabdominal and transvaginal ultrasonography (US) is not under the scope of this chapter, it remains the first-line imaging method for most gynecological conditions.info:eu-repo/semantics/publishedVersio

Tailoring Surface Adsorption and Reactivity of Fullerene-Based Compounds: A Theoretical Probe into C₂–Gas–Fullerene Surface Interactions

Density functional theory investigations of palladium and nickel substituted fullerenes (C₅₉M; M = Pd/Ni) were carried out probing the changes in their surface adsorption potential. Structure and bonding in the proposed heterofullerenes were established with insights into metal–carbon bond character, stability, and adsorption potential. C₂‑gases were used as probe gases for adsorption tests. Adsorption of acetylene, ethylene, and ethane was studied with different sites over pure and heterofullerenes. Adsorption of acetylene was stronger than the adsorption of ethylene and ethane over C₆₀ with the bridge site sharing hexagonal rings being the energetically favored adsorption site. Surface modification of the fullerene molecule with a foreign metal enhanced the gas-substrate (C₂-heterofullerene) interactions. Enhanced surface interactions and differential adsorption behavior of different heterofullerenes made them potential candidates as selective acetylene hydrogenation catalysts. Free energy landscapes for hydrogenation of acetylene and ethylene over all three compounds were developed. The energy barriers for various elementary steps during hydrogenation were significantly smaller over the heterofullerenes when compared to those over C₆₀. Whereas substitution of either metals resulted in a reduction of activation barriers, the activation barriers for post-ethylene formation reactions were smaller over C₅₉Ni making C₅₉Pd a good selective acetylene hydrogenation catalyst

Hydraulic Spring Stiffness Testing Machine

In many engineering machines and mechanisms spring is an essential component used for proper functioning of that machine for maximum efficiency, there are many applications of springs in automobile suspension system, IC engine valves , brakes, clutches, measurements of weights, for storing energy such as in spring type accumulator, in shock absorber, in hydraulic components such as hydraulic cylinders, pressure relief valves, flow control valves etc. But according to the our market survey and observations sometimes spring used in above applications having a many defects such as manufacturing defects, processing defects like defects occurs at the time of hardening sometimes this causes the more hardened spring which has more stiffness value and sometimes causes a less stiffness value of spring, hence this creates a problems on the applications of the springs for proper uses and creates a problems in working of that machinecomponents.By considering this problem we can easily measure spring stiffness by using this machine in low cos

Evaluation of Progressive Failure of Composite T-Joint Using Mixed Mode Cohesive Zone Model.

T shaped stiffeners are the most commonly used structures in aerospace components. De-lamination/de-bond initiation followed by its growth is one of the most common reasons for failure in a fiber reinforced composite structure. It is caused by the interlaminar normal and shear stresses between different structural constituents. In a typical structural T-joint, the failure mechanism and location may differ based on the structural design parameters like fillet radius, thickness, layup sequence, filler stiffness, etc. In this study, finite element analysis has been performed using cohesive zone model (CZM) on a composite T-joint to simulate the pull out test conditions. A simplified plane strain model coupled with CZM is proposed, which can evaluate the failure initiation and progression accurately with lesser computational efforts. The final failure occurs at a displacement of 8.04 mm and the computed failure load is 2240 N. The results obtained by the proposed numerical model are validated by experimental results and it is observed that predicted regions of failure, failure displacements and failure load calculated are correlating reasonably well with the experiment

Structural Properties of Nanosized NiFe2O4 for LPG Sensor

Nanocrystalline NiFe2O4 has been synthesized by sol-gel citrate method. The synthesized powder was characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). As found from the XRD line broadening, the crystallite size of the powder was found to be 40 nm. The gas sensing properties were studied for reducing gases such as LPG, CH4, CO and NH3. It was observed that the nanosized NiFe2O4 shows high sensitivity for LPG at an operating temperature 300 oC. Pd incorporation in NiFe2O4 results in a decrease in operating temperature by 100 oC and improves the sensing characteristics in terms of response time