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First Principles Investigation of Fluorine Based Strontium Series of Perovskites

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Communications in Theoretical Physics 2016年第11期65卷 571-578页

作者： nazia Erum Muhammad Azhar lqbal Physics Department University of the PunjabQuaid-e-Azam CampusP.O.Box 54590 LahorePakistan School of Science University of Management and TechnologyC-11Johar Town CampusP.O.Box 54770 LahorePakistan

Density functional theory is used to explore structural, elastic, and mechanical properties of SrLiF3, SrNaF3, SrKF3 and SrRbF3 fluoroperovskite compounds by means of an ab-initio Full Potential-Linearized Augmented Plane Wave （FP-LAPW） method. Several lattice parameters are employed to obtain accurate equilibrium volume （Vo）. The resultant quantities include ground state energy, elastic constants, shear modulus, bulk modulus, young＇s modulus, cauchy＇s pressure, poisson＇s ratio, shear constant, ratio of elastic anisotropy factor, kleinman＇s parameter, melting temperature, and lame＇s coetllcient. The calculated structural parameters via DFT as well as analytical methods are found to be consistent with experimental findings. Chemical bonding is used to investigate corresponding chemical trends which authenticate combination of covalent-ionic behavior. Farthermore electron density plots as well as elastic and mechanical properties are reported for the first time which reveals that fluorine based strontium series of perovskites are mechanically stable and posses weak resistance towards shear deformation as compared to resistance towards unidirectional compression while brittleness and ionic behavior is dominated in them which decreases from SrLiF3 to SrRbF3. Calculated cauchy＇s pressure, poisson＇s ratio and BIG ratio also proves ionic nature in these compounds. The present methodology represents an effective and influential approach to calculate the whole set of elastic and mechanical parameters which would support to understand various physical phenomena and empower device engineers for implementing these materials in numerous applications.

关键词： density functional theory fluoroperovskites mechanical properties elastic constants

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Blend of Polyhydroxyalkanoates Synthesized By Lipase Positive Bacteria From Plant Oils

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Journal of Renewable Materials 2019年第5期7卷 463-476页

作者： Nasir Javaid Rida Batool nazia Jamil Department of Microbiology and Molecular Genetics University of the PunjabQuaid-e-Azam CampusLahore-54590Pakistan

A total of 5 biochemically characterized lipase positive bacterial strains were screened for Polyhydroxyalkanoates(PHA)production by Nile blue staining and confirmation was done by Sudan Black *** production ability for all strains was optimized followed by time profiling calculation and comparison via using glucose and two plant oils i.e.,canola and mustard *** analysis showed that glucose can serve as a carbon source for maximum biomass(2.5 g/L CDW for strain 5)and PHA production(70.3%for strain 2).PHA produced by strain 2 was further analyzed for its chemical composition and type via Fourier Transform Infrared(FT-IR)*** revealed homopolymer(PHB)and copolymer(PHB-co-PHV)production of PHA(peaks at 1743 cm-1 and 2861 cm-1,respectively)with both canola and mustard oil unlike glucose which produced only homopolymer one i.e.,PHB(peaks at 1110 cm-1,1411 cm-1 and 1650 cm-1).Crystallinity of FT-IR analyzed PHA was calculated using mathematical formulas which showed decrease from glucose to canola to mustard *** study revealed that plant oils can serve as better carbon source to produce better quality(ductile and copolymer)***,16S rRNA gene sequencing analysis showed that strain 1,strain 2,strain 3,strain 4 and strain 5 are Stenotrophomonas sp.N3,Exiguobacterium sp.N4,Exiguobacterium ***3,Cellulosimicrobium sp.A8 and Klebsiella ***2,respectively.

关键词： Bioplastics polyhydroxyalkanoates lipase positive bacteria plant oils,FT-IR

Polyhydroxyalkanoates： Current applications in the medical field

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Frontiers in Biology 2016年第1期11卷 19-27页

作者： Iftikhar Ali nazia Jamil Microbiology and Molecular Genetics University of the Punjab Quaid-i-Azam Campus Lahore-54590 Pakistan

Polyhydroxyalkanoates （PHAs） are a class of biopolyesters that are synthesized intracellularly by microorganisms, mainly by different genera of eubacteria. These biopolymers have diverse physical and chemical properties that also classify them as biodegradable in nature and make them compatible to living systems. In the last two decades or so, PHAs have emerged as potential useful materials in the medical field for different applications owing to their unique properties. The lower acidity and bioactivity of PHAs confer them with minimal risk compared to other biopolymers such as poly-lactic acid （PLA） and poly-glycolic acid （PGA）. Therefore, the versatility of PHAs in terms of their non-toxic degradation products, biocompatibility, desired surface modifications, wide range of physical and chemical properties, cellular growth support, and attachment without carcinogenic effects have enabled their use as in vivo implants such as sutures, adhesion barriers, and valves to guide tissue repair and in regeneration devices such as cardiovascular patches, articular cartilage repair scaffolds, bone graft substitutes, and nerve guides. Here, we briefly describe some of the most recent innovative research involving the use of PHAs in medical applications. Microbial production of PHAs also provides the opportunity to develop PHAs with more unique monomer compositions economically through metabolic engineering approaches. At present, it is generally established that the PHA monomer composition and surface modifications influence cell *** synthesis by bacteria does not require the use of a catalyst （used in the synthesis of other polymers）, which further promotes the biocompatibility of PHA-derived polymers.

关键词： Biopolymers polyhydroxyalkanoates biocompatibility medical implantations

First principles investigation of protactinium-based oxide-perovskites for flexible opto electronic devices

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Chinese Physics B 2017年第4期26卷 368-376页

作者： nazia Erum Muhammad Azhar Iqbal Physics Department University of the PunjabQuaid-e-Azam CampusP.O.Box 54590 LahorePakistan School of Science University of Management and TechnologyC-llJohar Town CampusP.O.Box 54770 LahorePakistan

The structural,elastic,mechanical,electronic,and optical properties of KPaO_3 and RbPaO_3 compounds are investigated from first-principles calculations by using the WIEN2 k code in the frame of local density approximation（LDA） and generalized gradient approximation（GGA）.The calculated ground state quantities,such as lattice constant（α_0）,ground state energy（E）,bulk modulus（S）,and their pressure derivative（B_p） are in reasonable agreement with the present analytical and previous theoretical results and available experimental *** on several elastic and mechanical parameters,the structural stability,hardness,stiffness and the brittle and ductile behaviors are discussed,which reveal that protactiniumbased oxide series of perovskites is mechanically stable and possesses weak resistance to shear deformation compared with resistance to unidirectional compression while flexible and covalent behaviors are dominated in *** analysis of band profile through Trans-Blaha modified Becke-Johnson（TB-mBJ） potential highlights the underestimation of bandgap with traditional density functional theory（DFT） *** contribution of electronic states is investigated by means of total and partial density of states and it can be evaluated that both compounds are（Γ-Γ） direct bandgap *** fundamental optical properties are analyzed while attention is paid to absorption and reflection spectra to explore extensive absorptions and reflections of these compounds in high frequency *** present method represents an influential approach to calculating the whole set of elastic,mechanical,and opto-electronic parameters,which would conduce to the understanding of various physical phenomena and empower the device engineers to implement these materials in flexible opto-electronic applications.

关键词： first-principles study oxide perovskites mechanical property electronic property optical property

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Synthesis of scl-poly （3-hydroxyalkanoates） by Bacillus cereus found in freshwater, from monosaccharides and disaccharides

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Frontiers in Biology 2018年第1期13卷 63-69页

作者： Tayyaba Naeem Naima Khan nazia Jamil Department of Microbiology and Molecular Genetics University of the Punjab-Quaid-i-Azam Campus Lahore-54590 Pakistan

BACKGROUND： Polyhydroxyalkanoates are a good substitute for synthetic plastic because they are highly biocompatible, ecofriendly, and biodegradable. Bacteria in freshwater bodies such as rivers, tube wells, and canals are exposed to alternating high and low concentrations of substrates that induce PHA production. METHODS： Fresh water samples were collected for isolation of bacterial strains. Screening of PHA in bacterial cells was performed with Sudan and Nile Red staining. Extracted PHA was characterized by FTIR. RESULTS： In this study, nine bacterial isolates were selected for PHA production on the basis ofphenotypic screening. Their ability to accumulate PHAs was determined using different monosaccharides and disaccharides. Two bacterial isolates Bacillus cereus T1 （KY746353） and Bacillus cereus R3 （KY746354） produced PHAs. Optimal growth of the bacterial strain （T1） was observed in the presence of glucose, followed by maximum production of PHAs （63% PHAs） during the logarithmic phase of growth. B. cereus R3 （KY746354） accumulated 60% PHAs by dry cell weight. CONCLUSION： PHA accumulation was relatively less with fructose, but both strains showed increased production （up to 50%） with sucrose. The polymer produced was characterized by Fourier-transform infrared spectroscopy （FTIR）, which showed that the compound contains short-chain PHAs.

关键词： ecofriendly bioeompatible scl-poly (3-hydroxyalkanoates) Bacillus cereus

Glimpse into the future of prosthodontics:The synergy of artificial intelligence

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World Journal of Clinical Cases 2023年第33期11卷 7940-7942页

作者： Artak Heboyan nazia Yazdanie Naseer Ahmed Department of Prosthodontics Yerevan State Medical University after Mkhitar HeratsiYerevan 0025Armenia Department of Prosthodontics FMH College of Medicine and DentistryLahore 54000Pakistan Department of Prosthodontics Altammash Institute of Dental MedicineKarachi 75500Pakistan

Prosthodontics,deals in the restoration and replacement of missing and structurally compromised teeth,this field has been remarkably transformed in the last two *** the integration of digital imaging and threedimensional printing,prosthodontics has evolved to provide more durable,precise,and patient-centric ***,as we stand at the convergence of technology and healthcare,a new era is emerging,one that holds immense promise for the field and that is artificial intelligence(AI).In this paper,we explored the fascinating challenges and prospects associated with the future of prosthodontics in the era of AI.

关键词： Artificial intelligence Prosthodontics Treatment planning Patient-centric care Three-dimensional printing

Harmonic Enhancement by Combining XUV Pulse with Infrared Lasers

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Harmonic Enhancement by Combining XUV Pulse with Infrared La...

作者： nazia Abro 南京理工大学

学位级别：硕士

High-order harmonic generation（HHG）is a nonlinear process in which an intense infrared（IR）laser pulse interacts with gas *** has become an important tool for providing tabletop subfemtosecond or a few tens of attosecond light sources with great brightness and coherence from the extreme ultraviolet（XUV）to ***,the low conversion efficiency of HHG has limited its wide applications in science and *** this thesis,we investigate how to enhance the harmonic yields with the assistance of XUV attosecond *** on the strong-field approximation（SFA）,we simulate the single-atom high harmonic spectra under different *** compare the harmonic spectra obtained by the two-color laser waveform consisting of the 800-nm laser and its second or third harmonic field with those obtained by the single-color 800-nm *** also check the enhancement of harmonics generated by the 800-nm laser by adding the XUV *** mechanism of XUV parametric amplification（XPA）indeed works for different atomic targets and different applied XUV *** next propose a scheme of the two-color waveform combining with the XUV attosecond pulse to further enhance the harmonic *** two-color waveform can be modified by varying the relative phase between the two colors,and the intensities of individual *** thus investigate the effect of harmonic enhancement with the assistance of XUV pulse under a number of different ***,we take a close look of the enhancement factor as a function of the time delay between the XUV pulse and IR ***-frequency analysis of harmonic emission is also shown to uncover the physical mechanism of harmonic *** find that the XPA in the suggested scheme is valid,in which the harmonic radiation is emitted by forward scattering of the XUV field from the electron wave *** scheme can be used to improve the harmonic yields in the XUV or in the soft *** then study the effect of macro

关键词： extreme ultraviolet infrared laser high-order harmonic generation attosecond pulse two-color waveform

Length-weight relationship of eleven species of marine catfishes from the northern Arabian Sea coast of Pakistan

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Chinese Journal of Oceanology and Limnology 2017年第5期35卷 1218-1220页

作者： Noureen FAROOQ nazia QAMAR Shahnaz RASHID Sher Khan PANHWAR Center of Excellence in Marine Biology University of Karachi Sindh Pakistan

This study records length-weight relationships （LWRs） for eleven commercially important marine catfish species of the family Ariidae （sea catfishes） and Plotosidae （eel catfishes） from the northern Arabian Sea coast of Pakistan. The specimens were sampled from December 2014 to November 2015, using bottom trawls with various mesh sizes by commercial vessels. The species were Nemapteryx caelatus, Sciades sona, Arius gagora, Batrachocephalus mino, Neturna thalassina, N. bilineata, Osteogeneiosus militaris, Plicofollis dussumieri, P. tenuispinis, Plotosus limbatus, and P. lineatus. Of the eleven species, two species A. gagora and N. bilineata were recorded for the first time and LWRs for four species A. gagora, N. bilineata, S. sona, and B. mino still have no data in the FishBase database. In addition, new maximum length for each of the three species N. bilineata, O. militaris andB. mino was also found.

关键词： marine catfishes Arridae Plotosidae northern Arabian Sea

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Biosynthesis of polyhydroxyalkanoates from styrene by Enterobacter spp. isolated from polluted environment

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Frontiers in Biology 2017年第3期12卷 210-218页

作者： Arooj Arshad Bisma Ashraf Iftikhar Ali nazia Jamil Department of Microbiology and Molecular Genetics University of the Punjab Quaid-e-Azam Campus Lahore-54590 Pakistan

BACKGROUND： Styrene and its metabolites are known to have serious adverse effects on human health and hence, strategies to prevent its release, eradicate it from the environment, and understand its route of degradation are being considered. METHODS： A total of 18 strains were isolated from 4 samples of diesel contaminated soils. Among them 5 strains were selected for their ability to degrade styrene and use it as a sole carbon source to produce PHA. These strains were identified as Enterobacter spp. on the basis of 16S rRNA gene sequencing. Bacteria were screened for their ability to produce PHA by utilizing glucose and styrene as a carbon sources. Screening for PHA production was done by Nile blue A, Sudan black B, and phase contrast microscopy and the selected 3 strains showed positive results. Growth kinetics along with time profiling of PHA was performed for glucose and styrene as carbon sources. RESULTS： PHA extraction was done at equal intervals of 12 h by sodium hypochlorite method which showed that these strains accumulate maximum amount of PHA after 48 h in glucose （30.60%）. FTIR analysis of PHA was done which revealed homopolymer PHB and copolymer （PHB-co-PHV） production in strains by utilizing glucose and styrene. Gas chromatography mass spectrometry was carried out to identify the metabolites produced by bacterial strains grown on styrene. Metabolites of styrene degradation included propyne and phenylalanine. Genomic DNA isolation was carried out to amplify phaC gene which encodes PHA synthase enzyme. CONCLUSIONS： The conversion of styrene to polyhydroxyalkanoates （PHA） provides a new and unique link between an aromatic environmental pollutant and aliphatic PHA accumulation.

关键词： biodegradable polymers environmental pollutants PHA FTIR recycling bacteria