Transfer learning in deep neural network-based receiver coil sensitivity map estimation

Magnetic Resonance Materials in Physics, Biology and Medicine - The success of parallel Magnetic Resonance Imaging algorithms like SENSitivity Encoding (SENSE) depends on an accurate estimation of...     

Thermal Conductivity of Silicate and Borate Glasses

Thermal conductivities of silicate and borate glasses were determined at 30°C by steady-state methods. From the experimental data, factors representing the contribution of individual oxides (on a weight-percent basis) were calculated by the least-squares method. The experimental thermal conductivities and those calculated from the factors obtained agree fairly well.     

Influence of different viscosity grade cellulose-based polymers on the development of valsartan controlled release tablets

This work is based on formulating and optimizing controlled release (CR) valsartan (160 mg) tablets using different viscosity grades of the cellulosic polymer. The objective was to develop an effective once-daily drug delivery system of this cardiovascular agent. Central composite design was used for designing the formulations. Polymers used were Methocel® K4M, K15M and K100M. Compatibility of excipients with active was studied through FT-IR. Micromeritic properties were determined and formulations exhibiting appropriate flow characteristics were compressed. Swelling behavior and in vitro buoyancy effect were studied and response surface curves were constructed to optimize the formulation. Multi-point dissolution profiles of valsartan CR tablets at pH 1.2, 4.5 and 6.8 were obtained. Model-dependent and model-independent methods were performed including f2, stability test as per ICH guidelines and ANOVA. FT-IR studies revealed the compatibility of valsartan with all excipients. Formulation K4T9 (containing 25% K4M polymer) was selected to be the best optimized trial, based on physical properties and controlled release profile (23% at 4 h, 82% at 16 h and 100% at 24 h). Results of buoyancy and swelling behavior indicated that HPMC-K4M polymer exhibited excellent floating lag time and swelling indexes. In vitro drug release kinetics showed that formulation K4T9 displayed Korsmeyer–Peppas drug release pattern with r value > 0.99. The manufacturing process of K4T9 was also found to be reproducible with a shelf life period of 41 and 36 months at room temperature and accelerated conditions, respectively. Valsartan CR matrix-based formulation was successfully prepared with Methocel K4M retardant.     

Interference and Resource management strategy for handover in femtocells

Interference in femtocells due to neighboring femtocells and macrocells is a major issue of two-tier networks. Handover should be made to reduce interference, if and only if, when resources are available. Otherwise, it will further degrade network performance. Resource management should be made in an efficient manner that will not cause interference between macrocells and neighboring femtocells. Since distance between macro base station (MBS) and femto access point (FAP) is short, therefore, it is very hard to sustain low handover probability when macro user moves from MBS to FAP. We proposed handover algorithm for uplink co-channel interference mitigation that will make handover decision on the basis of time-to-stay and signal to interference plus noise ratio thresholds along with efficient resource management mechanism to reduce number of handovers and also resolve interference problem.

     

Controlling the material removal and roughness of Inconel 718 in laser machining

Nickel alloys including Inconel 718 are considered as challenging materials for machining. Laser beam machining could be a promising choice to deal with such materials for simple to complex machining features. The machining accuracy is mainly dependent on the rate of material removal per laser scan. Because of the involvement of many laser parameters and complexity of the machining mechanism it is not always simple to achieve machining with desired accuracy. Actual machining depth extremely varies from very low to aggressively high values with reference to the designed depth. Thus, a research is needed to be carried out to control the process parameters to get actual material removal rate (MRR_act) equals to the theoretical material removal rate (MRR_th) with minimum surface roughness (SR) of the machined surfaces. In this study, five important laser parameters have been used to investigate their effects on MRR and SR. Statistical analysis are performed to identify the significant parameters with their strength of effects. Mathematical models have been developed and validated to predict the machining responses. Optimal set of laser parameters have also been proposed and confirmed to achieve the actual MRR close to the designed MRR (MRR_% = 100.1%) with minimum surface roughness (R_a = 2.67 µm).     

Characterization of the hard anodizing layers formed on 2014-T3 Al alloy,in sulphuric acid electrolyte containing sodium lignin sulphonate

The properties of hard anodizing layers formed on 2014 Al alloy in sulphuric acid electrolyte containing sodium lignin sulphonate were investigated. The corrosion behavior of 2014 Al alloy has been studied using potentiodynamic polarization technique. Anodic layers morphology and composition were examined by scanning electron microscope, energy dispersion X-ray (EDX), X-ray diffraction (XRD) and Fourier infrared spectroscopy (FTIR). The results showed that the corrosion resistance has been enhanced after hard anodizing of 2014 Al alloy. Addition of lignin sulphonate to the sulphuric acid electrolyte significantly improved the corrosion resistance of the anodized 2014 aluminum alloy by adsorption on copper-intermetallic phases. Adsorption of sodium lignin sulphonate on oxide surface has been confirmed by SEM, EDX, and FTIR. Phenolic and carboxylic groups in sodium lignin sulphonate are functional groups, which are responsible of complex formation on oxide surface. The morphology of the hard anodizing layer is non-homogenous due to the high copper content of 2014 Al alloy. Addition of sodium lignin sulphonate resulted in the formation of anodic layers with more homogeneity and fewer cracks.     

Association of microstructure and electric heterogeneity in BiFeO3

BiFeO₃ ceramics was synthesized by solid state reaction technique. Synchrotron X-ray diffraction analysis was employed to investigate the phase formation and structure determination. Rietveld refinement of the diffracted data confirmed the rhombohedrally distorted perovskite structure with space group R3c. Localized atomic structure determined from fitted X-ray data showed off centered displacement of Fe³⁺ cations with a magnitude of 0.397 Å along c-axis. The FeO₆ octahedron comprised of two types of Fe–O bonds with bond lengths of ∼1.935 Å and ∼2.131 Å. Impedance spectroscopic data collected in wide temperature (300–400 K) and frequency (200 Hz–2 MHz) ranges, demonstrated two relaxation phenomena corresponding to two heterogeneous phases. The best fits to the collected impedance data were achieved by employing an equivalent circuit model R_g(R_gbC_gb)(R_eQ_e). Grain boundaries showed only p-type small polaronic hopping conduction process assisted with the oxidation of Fe³⁺ to Fe⁴⁺ in measured temperature range of 300–400 K. Grains exhibited p-type small polaronic hopping conduction mechanism up to 375 K; however, above 375 K electronic conduction becomes prominent. Conduction is dominated by short range hopping of the polarons among Fe³⁺ and Fe⁴⁺ or through the first ionized oxygen vacancy bridge between Fe³⁺ and Fe²⁺ cations.     

Comparative studies of some local oil seeds and seed cakes

A survey on the chemical constituents (protein, fat, carbohydrates, ash, fibre, calcium, phosphorus, iron) of 4 seeds and their cakes was done. These seeds are safflower seed (Carthamus tinctorius variety Giza 1), sunflower seeds (Helianthus annuus variety Giza 1), linseeds (Linum usitatissimum variety Giza 4) and imported rape seeds (Brassica napus Erglue). Caloric value of these seeds and seed cakes was calculated, PER, NPR and NPU were determined. No great variation was found with respect to the moisture content. The 4 seeds are rich in protein and fat. The ash content varies from (5.11 ± 0.26)% to (3.17 ± 0.13)%. The fiber content was low in both safflower and sunflower seeds and higher in both linseeds and rape seeds. The caloric values of the different seeds were very close. The seeds were found to be rich in phosphorus and low in calcium and contain considerable amounts of iron. The average PER values were 1.51, 1.61, 1.59, 1.84 and 2.50 for safflower seed cake, sunflower seed cake, linseed cake, rape seed cake and casein diet respectively. The average NPR was 3.11, 2.84, 2.84, 3.05 and 3.53 for safflower seed cake, sunflower seed cake, linseed cake, rape seed cake and casein respectively. The NPU values of the seed meals were 48.5, 49.3, 47.4 and 93.6 compared with 67.8 for casein. Using the different criteria (PER, NPR and NPU), it was clear that the protein quality of sunflower seed is very close to that of the linseed. Comparing the protein quality of safflower seed with those of both sunflower and linseed, NPU was in the same range, while PER was somewhat lower and NPR was higher than those of safflower and sunflower seed.     

Engineering Versatile Nanoparticles for Near‐Infrared Light‐Tunable Drug Release and Photothermal Degradation of Amyloid β

Nanomedicines that inhibit/disassemble amyloid β (Aβ) aggregates in Alzheimer's disease (AD) are highly desirable yet remain challenging. Therapeutic efficacy and systemic delivery of reported molecules and nanoparticles (NPs) are hampered by various challenges, including low biocompatibility, off‐target toxicity, and lack of specificity. Herein, a versatile NP is designed by integrating high Aβ‐binding affinity, stimuli‐responsive drug release, and photothermal degradation properties for efficient disassembly of Aβ. Near‐infrared (NIR)‐absorbing conjugated polymer PDPP3T‐O14 serves as a photothermal core while thermal‐responsive polymer 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine at the outer layer as the NIR‐stimuli gatekeeper. Curcumin, an inhibitor of Aβ aggregation, is loaded into the NP with high encapsulation efficiency. The 5‐mer β‐sheet breaker peptides LPFFD (Leu‐Pro‐Phe‐Phe‐Asp) having high binding affinity toward Aβ are further anchored onto the surface of polyethylene glycol‐lipid shell for active Aβ‐targeting. The resultant NPs exhibit good Aβ‐targeting ability and obvious photothermal dissociation effect together with Aβ aggregation‐dependent fluorescence detection capability. Upon NIR laser irradiation, entrapped curcumin can be effectively released from the unconsolidated NPs to enhance the anti‐amyloid activity. In vitro studies demonstrate that the NPs dramatically lower Aβ‐induced cytotoxicity of PC12 cells, and therefore show great potential for the application in AD treatment.