Protonic ceramic fuel cells have become extremely interesting due to their high power output at t... more Protonic ceramic fuel cells have become extremely interesting due to their high power output at the intermediate temperature range (400–700 °C). Significant progress has been made to develop electrolyte materials, doped barium cerates-zirconate, which gets the leading role due to its high chemical stability and high ionic conductivity. Here, we present a new composition BaCe 0.5 Zr 0.3 Y 0.1 Yb 0.05 Zn 0.05 O 3- δ (BCZYYbZn05), where addition of 5 mol% Zn with Ce, Zr, Y, and Yb at the B-site of the perovskite material shows high stability with high conductivity. The material was synthesized by solid-state reaction route at 1400 °C which showed 98% relative density. Rietveld analysis of neutron powder diffraction data reveal an orthorhombic structure with Pbnm space group. Thermogravimetric analysis shows about 1.06% weight loss from 200 to 1000 °C which is mainly related to the formation of the oxygen vacancies. In wet hydrogen atmosphere, this material shows higher conductivity and lower activation energy than dry hydrogen atmosphere indicates the conduction type as protonic conduction. The anode-supported single test cell based on this electrolyte material demonstrates peak power densities 649 mW cm −2 at 700 °C using conventional BSCF cathode, representing an important step toward commercially viable SOFC technology.
Despite the recent substantial progress in reversible protonic ceramic cells (RPCCs) it remains e... more Despite the recent substantial progress in reversible protonic ceramic cells (RPCCs) it remains essential to further develop oxygen electrode materials that show superior activity and stability for oxygen reduction and evolution reactions due to the intrinsically sluggish kinetics of oxygen electrode reactions at lower temperature (<700 °C).
Implantation with aluminium ions (Al + ) was investigated for producing amorphous, microcrystalli... more Implantation with aluminium ions (Al + ) was investigated for producing amorphous, microcrystalline and crystalline phases in the refractory metals tantalum, niobium and vanadium. Surface alloys with a substantial aluminum content resulted from the implantation, reaching more than ...
Tantalum was implanted with 180 keV Al+ ions to fluences up to 3�1018 Al+/cm2. Subsequent microch... more Tantalum was implanted with 180 keV Al+ ions to fluences up to 3�1018 Al+/cm2. Subsequent microchemical and microstructural observations showed that an amorphous layer covered the surface and extended to depths near 3000 � for fluences above 2.4�1018 Al+/cm2. The layer, comprised of ∼70 at. pet Al and ∼30 at. pet Ta, crystallized at temperatures above 500�C. Oxidation measurements, performed
Ion implantation produces thin films or layers that reside within a substrate rather than on top ... more Ion implantation produces thin films or layers that reside within a substrate rather than on top of it. The layers extend to the surface, differ in chemical composition and/or microstructure as compared with the substrate, and often modify the surface-dependent properties of the substrate material. Selected examples of modified properties are presented in this article and include improvements in oxidation and wear resistance from ion implantation. The shallow depths of the modified layers and the small scales of the implanted microstructures require the use of several modern analytical techniques for their characterization. Examples of such characterizations are also presented in this article. The implanted layers are examined for chemical concentrations versus depth with Auger electron spectroscopy and controlled sputtering, and with Rutherford backscattering spectrometry. Scanning electron microscopy and electron backscattering channeling analysis yield, respectively, information regarding products formed during oxidation and amorphous phase formed during implantation. Transmission electron microscopy and diffraction quantify the microstructures within the implanted layer and identify crystalline, nanocrystalline, and amorphous phases. Finally, it is shown that lattice imaging delineates atomic level defects, including stacking faults in-3 nm implanted rare gas precipitates, and amorphous phase formed during deceleration of the incident ions within intermetallic NiA13 phase.
A critical issue to tackle before successful commercialization of solid oxide fuel cells (SOFCs) ... more A critical issue to tackle before successful commercialization of solid oxide fuel cells (SOFCs) can be achieved is the long-term thermal stability required for SOFCs to operate reliably without significant performance degradation despite enduring thermal cycling. In this work, the impact of thermal cycling on the durability of NiO-yttria-stabilized zirconia-based anode-supported cells is studied using three different heating/cooling rates (1, 2, and 5 °C min-1) as the temperature fluctuated between 400 and 700 °C. Our experiments simulate time periods when power from SOFCs is not required (e.g., as might occur at night or during an emergency shutdown). The decay ratios of the cell voltages are 8.8% (82 μV h-1) and 19.1% (187 μV h-1) after thermal cycling testing at heating/cooling rates of 1 and 5 °C min-1, respectively, over a period of 1000 h. The results indicate SOFCs that undergo rapid thermal cycling experience much greater performance degradation than cells that experience slow heating/cooling rates. The changes in total resistance for thermally cycled cells are determined by measuring the Rpol of the electrodes (whereas the ohmic resistances of the cells remain unchanged from their initial value), signifying that electrode deterioration is the main degradation mechanism for SOFCs under thermal cycling. In particular, fast thermal cycling leads to severe degradation in the anode part of SOFCs with substantial agglomeration and depletion of Ni particles seen in our characterizations with field emission-scanning electron microscopy and electron probe microanalysis. In addition, the mean particle size in the cathode after thermal cycling testing increases from 0.104 to 0.201 μm for the 5 °C min-1 cell. Further, the presence of Sr-enriched regions is more significant in the La0.6Sr0.4Co0.2Fe0.8O3-δ cathode after fast thermally cycled SOFCs.
A greenhouse experiment was demonstrated to compare tolerance ability of four genotypes (Desi, Sa... more A greenhouse experiment was demonstrated to compare tolerance ability of four genotypes (Desi, Sanam, Kundri, Asia Bok) of Capsicum annum. L. under different levels of saline stress (i.e., control, 40, 80 and 120 mM NaCl). Growth parameters (root, shoot; fresh and dry weight) and physiological (Na+, K+, Ca++, concentration, stomatal conductance, transpiration rate, photosynthetic rate, chlorophyll a, b contents) indicators were analyzed to determine tolerability of genotypes. The results indicated that, all genotypes tolerated only under low level of salinity stress (40 mM NaCl) while a severe growth suppress in general was observed at higher levels (80 and 120 mM NaCl). Asia Bok was found more sensitive to salinity with 0.626g shoot fresh weight whereas Desi (1.103g) is comparatively salt tolerant under 120mMNaCl. Chlorophyll a and b contents and transpiration rate decreases with increases in salinity level in all genotypes with almost similar trend. Na+ accumulation increase with ...
The assignment of secondary structure elements in protein conformations is necessary to interpret... more The assignment of secondary structure elements in protein conformations is necessary to interpret a protein model that has been established by computational methods. The process essentially involves labeling the amino acid residues with H (Helix), E (Strand), or C (Coil, also known as Loop). When particular atoms are absent from an input protein structure, the procedure becomes more complicated, especially when only the alpha carbon locations are known. Various techniques have been tested and applied to this problem during the last forty years. The application of machine learning techniques is the most recent trend. This contribution presents the HECA classifier, which uses neural networks to assign protein secondary structure types. The technique exclusively employs Cα coordinates. The Keras (TensorFlow) library was used to implement and train the neural network model. The BioShell toolkit was used to calculate the neural network input features from raw coordinates. The study’s fin...
Intermetallic compounds based on refractory metals such as Nb, Mo, and W possess properties condu... more Intermetallic compounds based on refractory metals such as Nb, Mo, and W possess properties conducive to high temperature applications. Many of these intermetallics have very high melting points (above 1700 C) and retain their strength and stiffness to a high temperature (\u3e 1000°C). A serious impediment to the application of these materials is their low room temperature fracture toughness. A viable solution to this problem is to form in-situ composites of a brittle intermetallic compound and metallic phase. Room temperature toughness is improved in such composites by the ductile phase ligaments bridging cracks [1]. However, since the deformation of the continuous phase controls the overall deformation behavior of the composite, the role of the intermetallic matrix is also important, especially at temperatures where the intermetallic phase undergoes plastic deformation. Composites based on Nb - niobium silicide can be used as a model system for this class of materials. The room te...
International Journal of Computer Applications, 2021
"Internet of Things (IoT)"a relatively recent term, build on decades of research has revolutioniz... more "Internet of Things (IoT)"a relatively recent term, build on decades of research has revolutionized almost every field in today's world. IoT makes smart objects the ultimate building blocks in the development of cyber-physical smart pervasive frameworks. It has influenced our living from the way we react to the way we behave by utilizing the full potential of internet in enhancing the lifestyle of human beings. IoT is a network that connects physical devices of various domains like home automation, industrial process, vehicles, healthcare, weather monitoring, etc. to internet. From air conditioners that we can control with our smart phones, to smart cars providing the shortest route or smart watch which is tracking our daily activities. This paper is devoted to study the security architecture and its features in the domain of IoT. In the next part of the paper, the need and applications of IoT in various fields are discussed. This paper provides a general literature survey of recent progress and advances in the field of IoT. Next a hand-to-hand discussion of various issues and challenges being faced by various organizations are studied. In the final part of the paper, the most significant conclusions and suggestions are offered.
Objective: To determine the frequency of Osteoporosis in Chronic Obstructive Pulmonary Disease, (... more Objective: To determine the frequency of Osteoporosis in Chronic Obstructive Pulmonary Disease, (COPD). Study Design: Cross Sectional study. Setting: Husan Ara Unit, Gulab Devi Hospital Lahore. Period: July 2017 to January 2018. Material & Methods: One hundred fifty patients with COPD meeting the inclusion criteria were included in the study. Bone mineral density (BMD) was calculated in each patient. Bone mineral density (BMD) was calculated via Dual Energy X-ray Absorptiometry (DEXA) scan. Osteoporosis was labeled when value for BMD was found < –2.5 SD below the mean for young adults (T-score). Results: The mean age was 56.54+ 8.04 year. The majority (90.7%) of the patients were male and fourteen (9.3%) patients were female. The mean T-score was -2.07+ 0.76 SD. Twenty-two (14.7%) patients had BMD score within normal range, out of which nineteen were males and three were females. Fifty-seven (38.0%) patients were found to have osteopenia of which fifty-four were males and three w...
The manufacture and entrance into service of thin gage gamma-TiAl product has been hampered by th... more The manufacture and entrance into service of thin gage gamma-TiAl product has been hampered by the inherent low room temperature ductility of the material. In the present study a new approach was explored for the efficient manufacture of gamma-TiAl foil with improved ductility. The objective was to produce a very clean material (low interstitial content) with a highly refined, homogeneous microstructure placed in a fully lamellar condition. The processing route involved the use of RF plasma spray deposition of pre-alloyed powders, followed by consolidation via vacuum hot pressing and heat treatment. The approach took advantage of a deposition process which included no electrodes, no binders and high cooling rates. Results and discussion of the work performed to date are presented.
Protonic ceramic fuel cells have become extremely interesting due to their high power output at t... more Protonic ceramic fuel cells have become extremely interesting due to their high power output at the intermediate temperature range (400–700 °C). Significant progress has been made to develop electrolyte materials, doped barium cerates-zirconate, which gets the leading role due to its high chemical stability and high ionic conductivity. Here, we present a new composition BaCe 0.5 Zr 0.3 Y 0.1 Yb 0.05 Zn 0.05 O 3- δ (BCZYYbZn05), where addition of 5 mol% Zn with Ce, Zr, Y, and Yb at the B-site of the perovskite material shows high stability with high conductivity. The material was synthesized by solid-state reaction route at 1400 °C which showed 98% relative density. Rietveld analysis of neutron powder diffraction data reveal an orthorhombic structure with Pbnm space group. Thermogravimetric analysis shows about 1.06% weight loss from 200 to 1000 °C which is mainly related to the formation of the oxygen vacancies. In wet hydrogen atmosphere, this material shows higher conductivity and lower activation energy than dry hydrogen atmosphere indicates the conduction type as protonic conduction. The anode-supported single test cell based on this electrolyte material demonstrates peak power densities 649 mW cm −2 at 700 °C using conventional BSCF cathode, representing an important step toward commercially viable SOFC technology.
Despite the recent substantial progress in reversible protonic ceramic cells (RPCCs) it remains e... more Despite the recent substantial progress in reversible protonic ceramic cells (RPCCs) it remains essential to further develop oxygen electrode materials that show superior activity and stability for oxygen reduction and evolution reactions due to the intrinsically sluggish kinetics of oxygen electrode reactions at lower temperature (<700 °C).
Implantation with aluminium ions (Al + ) was investigated for producing amorphous, microcrystalli... more Implantation with aluminium ions (Al + ) was investigated for producing amorphous, microcrystalline and crystalline phases in the refractory metals tantalum, niobium and vanadium. Surface alloys with a substantial aluminum content resulted from the implantation, reaching more than ...
Tantalum was implanted with 180 keV Al+ ions to fluences up to 3�1018 Al+/cm2. Subsequent microch... more Tantalum was implanted with 180 keV Al+ ions to fluences up to 3�1018 Al+/cm2. Subsequent microchemical and microstructural observations showed that an amorphous layer covered the surface and extended to depths near 3000 � for fluences above 2.4�1018 Al+/cm2. The layer, comprised of ∼70 at. pet Al and ∼30 at. pet Ta, crystallized at temperatures above 500�C. Oxidation measurements, performed
Ion implantation produces thin films or layers that reside within a substrate rather than on top ... more Ion implantation produces thin films or layers that reside within a substrate rather than on top of it. The layers extend to the surface, differ in chemical composition and/or microstructure as compared with the substrate, and often modify the surface-dependent properties of the substrate material. Selected examples of modified properties are presented in this article and include improvements in oxidation and wear resistance from ion implantation. The shallow depths of the modified layers and the small scales of the implanted microstructures require the use of several modern analytical techniques for their characterization. Examples of such characterizations are also presented in this article. The implanted layers are examined for chemical concentrations versus depth with Auger electron spectroscopy and controlled sputtering, and with Rutherford backscattering spectrometry. Scanning electron microscopy and electron backscattering channeling analysis yield, respectively, information regarding products formed during oxidation and amorphous phase formed during implantation. Transmission electron microscopy and diffraction quantify the microstructures within the implanted layer and identify crystalline, nanocrystalline, and amorphous phases. Finally, it is shown that lattice imaging delineates atomic level defects, including stacking faults in-3 nm implanted rare gas precipitates, and amorphous phase formed during deceleration of the incident ions within intermetallic NiA13 phase.
A critical issue to tackle before successful commercialization of solid oxide fuel cells (SOFCs) ... more A critical issue to tackle before successful commercialization of solid oxide fuel cells (SOFCs) can be achieved is the long-term thermal stability required for SOFCs to operate reliably without significant performance degradation despite enduring thermal cycling. In this work, the impact of thermal cycling on the durability of NiO-yttria-stabilized zirconia-based anode-supported cells is studied using three different heating/cooling rates (1, 2, and 5 °C min-1) as the temperature fluctuated between 400 and 700 °C. Our experiments simulate time periods when power from SOFCs is not required (e.g., as might occur at night or during an emergency shutdown). The decay ratios of the cell voltages are 8.8% (82 μV h-1) and 19.1% (187 μV h-1) after thermal cycling testing at heating/cooling rates of 1 and 5 °C min-1, respectively, over a period of 1000 h. The results indicate SOFCs that undergo rapid thermal cycling experience much greater performance degradation than cells that experience slow heating/cooling rates. The changes in total resistance for thermally cycled cells are determined by measuring the Rpol of the electrodes (whereas the ohmic resistances of the cells remain unchanged from their initial value), signifying that electrode deterioration is the main degradation mechanism for SOFCs under thermal cycling. In particular, fast thermal cycling leads to severe degradation in the anode part of SOFCs with substantial agglomeration and depletion of Ni particles seen in our characterizations with field emission-scanning electron microscopy and electron probe microanalysis. In addition, the mean particle size in the cathode after thermal cycling testing increases from 0.104 to 0.201 μm for the 5 °C min-1 cell. Further, the presence of Sr-enriched regions is more significant in the La0.6Sr0.4Co0.2Fe0.8O3-δ cathode after fast thermally cycled SOFCs.
A greenhouse experiment was demonstrated to compare tolerance ability of four genotypes (Desi, Sa... more A greenhouse experiment was demonstrated to compare tolerance ability of four genotypes (Desi, Sanam, Kundri, Asia Bok) of Capsicum annum. L. under different levels of saline stress (i.e., control, 40, 80 and 120 mM NaCl). Growth parameters (root, shoot; fresh and dry weight) and physiological (Na+, K+, Ca++, concentration, stomatal conductance, transpiration rate, photosynthetic rate, chlorophyll a, b contents) indicators were analyzed to determine tolerability of genotypes. The results indicated that, all genotypes tolerated only under low level of salinity stress (40 mM NaCl) while a severe growth suppress in general was observed at higher levels (80 and 120 mM NaCl). Asia Bok was found more sensitive to salinity with 0.626g shoot fresh weight whereas Desi (1.103g) is comparatively salt tolerant under 120mMNaCl. Chlorophyll a and b contents and transpiration rate decreases with increases in salinity level in all genotypes with almost similar trend. Na+ accumulation increase with ...
The assignment of secondary structure elements in protein conformations is necessary to interpret... more The assignment of secondary structure elements in protein conformations is necessary to interpret a protein model that has been established by computational methods. The process essentially involves labeling the amino acid residues with H (Helix), E (Strand), or C (Coil, also known as Loop). When particular atoms are absent from an input protein structure, the procedure becomes more complicated, especially when only the alpha carbon locations are known. Various techniques have been tested and applied to this problem during the last forty years. The application of machine learning techniques is the most recent trend. This contribution presents the HECA classifier, which uses neural networks to assign protein secondary structure types. The technique exclusively employs Cα coordinates. The Keras (TensorFlow) library was used to implement and train the neural network model. The BioShell toolkit was used to calculate the neural network input features from raw coordinates. The study’s fin...
Intermetallic compounds based on refractory metals such as Nb, Mo, and W possess properties condu... more Intermetallic compounds based on refractory metals such as Nb, Mo, and W possess properties conducive to high temperature applications. Many of these intermetallics have very high melting points (above 1700 C) and retain their strength and stiffness to a high temperature (\u3e 1000°C). A serious impediment to the application of these materials is their low room temperature fracture toughness. A viable solution to this problem is to form in-situ composites of a brittle intermetallic compound and metallic phase. Room temperature toughness is improved in such composites by the ductile phase ligaments bridging cracks [1]. However, since the deformation of the continuous phase controls the overall deformation behavior of the composite, the role of the intermetallic matrix is also important, especially at temperatures where the intermetallic phase undergoes plastic deformation. Composites based on Nb - niobium silicide can be used as a model system for this class of materials. The room te...
International Journal of Computer Applications, 2021
"Internet of Things (IoT)"a relatively recent term, build on decades of research has revolutioniz... more "Internet of Things (IoT)"a relatively recent term, build on decades of research has revolutionized almost every field in today's world. IoT makes smart objects the ultimate building blocks in the development of cyber-physical smart pervasive frameworks. It has influenced our living from the way we react to the way we behave by utilizing the full potential of internet in enhancing the lifestyle of human beings. IoT is a network that connects physical devices of various domains like home automation, industrial process, vehicles, healthcare, weather monitoring, etc. to internet. From air conditioners that we can control with our smart phones, to smart cars providing the shortest route or smart watch which is tracking our daily activities. This paper is devoted to study the security architecture and its features in the domain of IoT. In the next part of the paper, the need and applications of IoT in various fields are discussed. This paper provides a general literature survey of recent progress and advances in the field of IoT. Next a hand-to-hand discussion of various issues and challenges being faced by various organizations are studied. In the final part of the paper, the most significant conclusions and suggestions are offered.
Objective: To determine the frequency of Osteoporosis in Chronic Obstructive Pulmonary Disease, (... more Objective: To determine the frequency of Osteoporosis in Chronic Obstructive Pulmonary Disease, (COPD). Study Design: Cross Sectional study. Setting: Husan Ara Unit, Gulab Devi Hospital Lahore. Period: July 2017 to January 2018. Material & Methods: One hundred fifty patients with COPD meeting the inclusion criteria were included in the study. Bone mineral density (BMD) was calculated in each patient. Bone mineral density (BMD) was calculated via Dual Energy X-ray Absorptiometry (DEXA) scan. Osteoporosis was labeled when value for BMD was found < –2.5 SD below the mean for young adults (T-score). Results: The mean age was 56.54+ 8.04 year. The majority (90.7%) of the patients were male and fourteen (9.3%) patients were female. The mean T-score was -2.07+ 0.76 SD. Twenty-two (14.7%) patients had BMD score within normal range, out of which nineteen were males and three were females. Fifty-seven (38.0%) patients were found to have osteopenia of which fifty-four were males and three w...
The manufacture and entrance into service of thin gage gamma-TiAl product has been hampered by th... more The manufacture and entrance into service of thin gage gamma-TiAl product has been hampered by the inherent low room temperature ductility of the material. In the present study a new approach was explored for the efficient manufacture of gamma-TiAl foil with improved ductility. The objective was to produce a very clean material (low interstitial content) with a highly refined, homogeneous microstructure placed in a fully lamellar condition. The processing route involved the use of RF plasma spray deposition of pre-alloyed powders, followed by consolidation via vacuum hot pressing and heat treatment. The approach took advantage of a deposition process which included no electrodes, no binders and high cooling rates. Results and discussion of the work performed to date are presented.
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Papers by mohammad saqib