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Similar to omega-3 eggs, chicken meat has great potential to become a functional food for humans. In India, chicken meat is preferred due to its perceived health benefits and affordability. The balance between omega 3 and 6 fatty acids is crucial for its usefulness in animals. At present commercial chicken meat has low omega-3 fatty acid content and higher omega-6 fatty acid content. Published research shows that it is possible to modify the lipid profile of commercial chickens by manipulating the broiler diet. The modern human diet is deficient in n-3 FAs, which has been linked to the increase in several degenerative diseases such as cardiovascular disease, diabetes, arthritis, cancer and mental illness. Therefore omega-3 chicken meat may be an effective means of increasing n-3 FA in the human diet. There are several problems associated with the commercial production of omega-3 chicken meat related to the choice of source of fatty acids in the feed, cost of production, consumer acceptability and stability of the chicken meat that need to be tackled. The present article briefly reviews the studies carried out in this respect, the possible impact of omega-3 chicken meat production on the poultry industry, and on human health.
This study investigated the personality traits of patients with allergic rhinitis. It also examined the association between personality type and the type of allergic rhinitis, and compared this with the general population.
A descriptive observational pilot study was carried out on 50 consecutive cases of allergic rhinitis who presented to the allergy clinic between June and October 2010. These patients were compared with a control group comprising 50 individuals from the general population that had no symptoms of allergic rhinitis. Both groups completed the International Personality Disorder Examination questionnaire for the assessment of personality traits.
Persons falling into cluster C personality type showed a positive correlation with the type and severity of allergic rhinitis. The majority of control group individuals fell into cluster A. This indicated a correlation between allergic rhinitis and a dominant anxious trait compared with the control group.
In psycho-allergological research, the potential relevance of personality factors in the maintenance and exacerbation of atopic symptoms is still a matter of debate. More attention should be paid to the psychological status of allergic rhinitis patients, and appropriate treatment should be provided to improve their symptoms and quality of life.
Polypropylene–clay (Cloisite Na+) composites with clay contents in weight percentage (wt%) ranging from 1 to 15% were characterized for crystallization mechanism and kinetics. Combination of differential scanning calorimetry, transmission electron microscopy (TEM), and polarized light microscopy was used to investigate the crystallization behavior. Different crystallization mechanisms were observed in the matrix with 1–5 wt% nanoclay compared to the matrix with 10 and 15 wt% of nanoclay additive. TEM micrographs revealed intercalated and flocculated morphology for all the concentrates. At lower wt%, well-dispersed clay platelets acted as antinucleating agent and reduced polymer chain mobility. At high wt%, nucleation rate overcomes the slow diffusion rate. In the case of samples with higher wt% of nanoclay additives, segregation and precipitation of clay was observed in the interspherulite region. On the basis of crystallization kinetics and morphology results, a schematic model of the nanocomposite formation is proposed.
We have prepared epitaxial thin films of Yy‐Pr1‐y‐Ba‐Cu‐O (y= 1 to 0) and superlattices of Y‐Ba‐Cu‐O/Yy‐Pr1‐y ‐Ba‐Cu‐O using pulsed laser deposition technique. The zero resistance transition temperatures of Yy‐Pr1‐y‐Ba‐Cu‐O bulk samples are reproduced in the films. The composition oscillations in the superlattices are observed by SIMS. The films and superlattices are found to have c‐axis orientations and good crystallinity.
Ion implantation technique is being investigated as an alternate technique for doping GaSb. Hence an understanding of the production and removal of the damage is essential. In this paper, we report on the damages produced by implantation of Te, Er, Hg and Pb ions into undoped (100) GaSb single crystals and their recovery by Rutherford backscattering (RBS)/channeling. The implantations of 1013 to 1013 ions/cm2 in GaSb were done at liquid nitrogen temperature at energies corresponding to the same projected range of 447Å. A comparison of the damage produced by the different ions and their recovery was made by RBS/channeling along <100> axis of GaSb. Near surface damage equivalent to that of an amorphous layer was observed even at lower doses. Upon annealing at 600°C for 30 sec., the Te implanted samples showed best recovery compared to others (Xmin = 11%), the value of Xmin being better than those normally observed in unimplanted Te-doped substrates.
We have characterized the surface topography of silicon films from different deposition and doping process sequences using AFM and optical reflectivity. The resulting surface structures after deposition, doping, oxide growth, and oxide removal correlate with the electrical leakage currents and breakdown voltages of double polysilicon capacitors. As-deposited amorphous films had smoother surfaces than those deposited in the crystalline state. Gas-phase diffusion doping increases the surface roughness. Only the amorphous in situ doped films retained a smooth surface following oxidation, yielding low leakage capacitors with breakdown fields above 8 MV/cm. Surprisingly, implanted amorphous films exhibited the roughest interfaces, resulting in lower breakdown fields. This study has shown that AFM provides an effective, quick, non-destructive diagnostic technique for semiconductor processing.
We have investigated the low temperature (4.5 K) photoluminescence (PL) spectra of GaSb and GaInAsSb layers. The layers were grown by liquid phase electro-epitaxial (LPEE) technique. Several bound excitomc transitions were observed both in GaSb and GaInAsSb layers. Shift in the PL peak energy corresponding to the band to band transition with temperature was determined. The linear part of the shift above 100K, exhibited a slope of -0.3 meV/K.
Thin films of Bi2VO5.5 (BVO), a vanadium analog of the n = I member of the Aurivillius family, have been prepared by pulsed laser deposition. The BVO films grow along the  direction on LaNiO3(LNO) and YBa2Cu3O7 (YBCO) electrode buffer layers on LaA- IO3(LAO) substrates as obtained from X-ray diffraction studies. The microstructure of the films and of the interfaces within the film and between the film and the substrate were characterized using transmission electron microscopy. The in-plane epitaxial relationship of the rhombohedral LNO on perovskite LAO was  LNO //  LAO and  LNO //  LAO. High resolution lattice images showed a sharp interface between LNO and LAO. However, the LNO film is twinned with a preferred orientation along the growth direction. The BVO layer is single crystalline on both LNO/LAO and YBCO/LAO with the caxis parallel to the growth direction except for a thin layer of about 400 Å at the interface which is polycrystalline.
Single wafer amorphous silicon deposition was characterized through process modeling and film characterization for application in semiconductor production. DOE methodology was used to determine the main deposition parameters, and the responses were limited to device production requirement properties of surface roughness, deposition rate and degree of crystallinity of the as-deposited film. The data trends and models show that deposition temperature and silane flow are the main factors. Increasing either or both factor increases the deposition rate and the surface roughness. The surface morphology, evaluated by AFM, SEM and TEM, was found to be rougher at extreme growth conditions than the poly crystalline film formed after anneal. The as-deposited surface morphology was not a result of pre-anneal crystal formations as determined by TEM cross sections of samples before and after anneal. Lack of crystalinity is important for impurity diffusion considerations. Device application of the single wafer a-Si process will be a compromise between growth rate (and associated throughput) and surface roughness that can be tolerated.
Gate dielectrics for advanced ULSI circuits are rapidly scaling below 10 nm. Thinner dielectrics and smaller lateral dimensions are essential to produce high performance transistors for memories, microprocessors and microcontrollers. In this overview we will discuss the factors that affect the performance and reliability of scaled gate dielectrics. Process parameters that affect oxide and oxynitride dielectrics include substrates, pre-gate cleaning, growth parameters and growth techniques as well as oxide and oxynitride dielectric materials. Thin dielectrics require new or modified measurement methods and extensive use of physical analysis techniques such as SIMS, XPS, AFM and TEM to characterize these materials. Boron diffusion through thin gate oxides, HCI stress, and process induced damage can degrade dielectric quality and affect long term reliability. These factors will affect the performance and reliability of circuits with scaled gate dielectrics.
In this study, we investigate the diffusion of mobile ions through thin PSG or SiN layers using secondary ion mass spectrometry (SIMS). The diffusivity of Na through either layer is about 100,000X slower than through SiO2. Hence, thin layers of these materials are effective barriers for short anneals at 400°C. However, there is significant diffusion of both Na and K through these layers at 550°C. This suggests that improved cleans will be required to remove mobile ion contamination after interconnect processes.
The dose loss and transient enhanced diffusion of indium in silicon were studied as a function of dose. Indium was implanted into silicon through a 90 A oxide at 50 keV for doses ranging from 3x 1012 to 2x14 cm−2. These conditions provide peak concentrations that approximately range from 1x1018-1x1020 cm−3. After an RTA anneal at 1000°C for 5s, indium exhibits substantial motion at both the tail and peak regions for high doses. The enhanced diffusion is mostly over within 5s. There was not any observable enhanced diffusion in the tail region at the lowest dose although there was significant movement at the peak region. The dose loss correlates very well with the enhancement in the diffusivity. TEM images show that the amorphization dose lies between 3x1013 and 8x1013 cm−2. In spite of the amorphization, diffusion enhancement in the tail region still keeps increasing with dose, which is contrary to a model of “+1” interstitials and complete removal of interstitials in the regrown layer. The 550°C lh anneals show that the dose loss can partially be attributed to the sweeping of the dopant by the growing a/c interface. Previously, the solubility of indium has been estimated to be around 1–2×1018 cm−3. At high doses, significant movement is observed at the peak of the indium profile although the peak concentration exceeds the solubility level by at least an order of magnitude. This shows that indium is not precipitating into an immobile phase like antimony or boron.
We have performed an optimization study of the mid-infrared photoresponse of p-type GaAs/AlGaAs Quantum Well Infrared Photodetectors (QWIPs) designed for normal incidence detection. In these p-type quantum wells, normal incidence absorption is allowed (by the dipole selection rules for optical transitions) especially for transitions from the heavy-hole ground state to the second light-hole state. Previous theoretical modeling predicted that this transition will produce the strongest bound-to-continuum infrared absorption when the second light-hole state is located very near the top of the GaAs quantum well. For AlGaAs barrier layers with 30% aluminum, our modeling showed that a well width between 45Å and 50Å would optimize the normal incidence photoresponse of this p-type QWIP. In this work, photore^oonse spectra are reported for well widths ranging from 40Å to 65Å. A series of samples were tudied in which only the GaAs well width was varied in two monolayer increments, from 11 to 20 monolayers. Photoluminescence and X-ray diffraction measurements were used to verify the composition, well width, and structural quality of each sample. This study verified that the spectral range of the normal incidence photoresponse is narrower, as predicted by theory, for well widths in which the second light-hole state approaches the top of the valence band well.
Tantalum pentoxide (Ta2O5) films were formed by oxidizing thin tantalum (Ta) films on bare and NO-nitrided silicon substrates. The 43-400 Å thick Ta films were deposited using physical vapor deposition (PVD) and oxidized using O2 for 2-60 min at 550-800 C in a furnace or single wafer tool. Uniform and stoichiometric Ta2O5 films were successfully produced as determined from XRD, AES depth profiling, XTEM, and ellipsometric analysis. The nitridation pretreatment was found to minimize the interfacial Ta-Si reactions which occur during the oxidation. Well-behaved CV and IV curves were obtained from mercury probe measurements. No CV hysteresis was observed. An equivalent oxide thickness of 38 Å and a leakage current of 7×10−9 A/cm2 at +1V were obtained for a 120 Å thick Ta2O5 film on a 15 Å interfacial SiO2 layer.
Nitrogen implantation can be used to control gate oxide thicknesses [1,2]. This study aims at studying the fundamental behavior of nitrogen diffusion in silicon. Nitrogen at sub-amorphizing doses has been implanted as N2+ at 40 keV and 200 keV into Czochralski silicon wafers. Furnace anneals have been performed at a range of temperatures from 650°C through 1050°C. The resulting annealed profiles show anomalous diffusion behavior. For the 40 keV implants, nitrogen diffuses very rapidly and segregates at the silicon/ silicon-oxide interface. Modeling of this behavior is based on the theory that the diffusion is limited by the time to create a mobile nitrogen interstitial.
The assessment of the thermal stability across HfO2/Si and HfO2/SiO2 interfaces has been difficult due to lack of thermodynamic data. In this paper, we present the results of thermodynamic calculations intended to fill this gap. A thermodynamic model was developed by assuming that HfSiO4 is an ideal solution of HfO2 and SiO2 to a first order approximation. The theoretical results predict that the HfO2/Si interface is thermodynamically stable up to 1100°C, while the HfO2/SiO2 interface is thermodynamically unstable even at room temperature. Our experimental results from TEM and XPS analysis are consistent with these modeling predictions.
We present experimental results regarding the thermodynamic stability of the high-k dielectrics ZrO2 and HfO2 in contact with Si and SiO2. The HfO2/Si interface is found to be stable with respect to formation of silicides whereas the ZrO2/Si interface is not. The metal oxide/SiO2 interface is marginally unstable with respect to formation of silicates. Cross-sectional transmission electron micrographs expose formation of nodules, identified as silicides, across the polysilicon/ZrO2/Si interfaces but not for the interfaces with HfO2. For both ZrO2 and HfO2, the X-ray photoemission spectra illustrate formation of silicate-like compounds in the MO2/SiO2 interface.
In this paper the impact of post deposition annealing in various ambient on electrical properties of hafnium zirconate (HfxZr1-xO2) high-k dielectrics is reported. ALD HfxZr1-xO2 films are annealed in a nitrogen and/or oxygen ambient at 500°C to 1000°C. Devices annealed at 500°C in N2 has lower equivalent oxide thickness (EOT) of 10Å without significant increase in gate leakage (Jg), threshold voltage (Vt) and only a slight decrease in transconductance (Gm) values compared to 500°C O2 annealed devices. Furthermore, the impact of annealing HfxZr1-xO2 films in a reducing ambient (NH3) is studied. Optimized NH3 anneal on HfxZr1-xO2 results in lower CET, improved PBTI, low sub-threshold swing values, comparable high-field Gm with only a minor degradation in peak Gm compared to control HfxZr1-xO2. Finally, the impact of laser annealing vs. RTP annealed HfxZr1-xO2 films are reported. Laser annealing helped further stabilize tetragonal phase of HfxZr1-xO2 without inducing void formation. Good devices with low leakage, low EOT and high mobility are obtained for laser annealed HfxZr1-xO2.
Virtual bronchoscopy is a noninvasive technique which provides an intraluminal view of the tracheobronchial tree. This study aimed to evaluate this technique in comparison with rigid bronchoscopy, in paediatric patients with tracheobronchial foreign bodies undetected by plain chest radiography.
Plain chest radiography was initially performed in 40 children with suspected foreign body aspiration. Computed tomography virtual bronchoscopy was performed in the 20 in whom chest radiography appeared normal. Virtual bronchoscopic images were obtained. All patients underwent rigid bronchoscopy performed by an otolaryngologist blinded to the computed tomography virtual bronchoscopy findings, within 24 hours. Virtual bronchoscopic findings were then compared with the results of rigid bronchoscopy.
In 12 patients, foreign bodies detected by virtual bronchoscopy were confirmed by rigid bronchoscopy. In one case, a mucous plug was perceived as a foreign body on virtual bronchoscopy. In another case, a minute foreign body was missed on virtual bronchoscopy. The following parameters were calculated: sensitivity, 92.3 per cent; specificity, 85.7 per cent; validity, 90 per cent; positive likelihood ratio, 6.45; and negative likelihood ratio, 0.089.
In the presence of a positive clinical diagnosis and negative chest radiography, computed tomography virtual bronchoscopy must be considered in all cases of tracheobronchial foreign body aspiration, in order to avoid needless rigid bronchoscopy. Computed tomography virtual bronchoscopy is particularly useful in screening cases of occult foreign body aspiration, as it has high sensitivity, specificity and validity.