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Effect of fluence and ambient environment on the surface and structural modification of femtosecond laser irradiated Ti

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Chinese Physics B 2016年第1期25卷 789-795页

作者： Umm-i-Kalsoom shazia bashir Nisar Ali m Shahid Rafique Wolfgang Husinsky Chandra S R Nathala Sergey V makarov Narjis Begum Institute for Applied Physics Vienna University of TechnologyViennaAustria Centre for Advanced Studies in Physics GC University LahorePakistan Department of Physics The University of LahorePala'stan Department of Basic Sciences and Humanities University of Engineering and Technology FasalabadPakistan Department of Physics University of Engineering and Technology LahorePakistan P.N.Lebedev Physics Institute RAS MoscowRussia Department of Physics COMSATS Institute of Information and TechnologyIslamabadPakistan

Under certain conditions, ultrafast pulsed laser interaction with matter leads to the formation of self-organized conical as well as periodic surface structures （commonly reffered to as, laser induced periodic surface structures, LIPSS）. The purpose of the present investigations is to explore the effect of fsec laser fluence and ambient environments （Vacuum ＆ 02） on the formation of LIPSS and conical structures on the Ti surface. The surface morphology was investigated by scanning electron microscope （SEm）. The ablation threshold with single and multiple （N = 100） shots and the existence of an incubation effect was demonstrated by SEm investigations for both the vacuum and the 02 environment. The phase analysis and chemical composition of the exposed targets were performed by x-ray diffraction （XRD） and energy dispersive x-ray spectroscopy （EDS）, respectively. SEm investigations reveal the formation of LIPSS （nano ＆ micro）. FFT d-spacing calculations illustrate the dependence of periodicity on the fluence and ambient environment. The periodicity of nano-scale LIPSS is higher in the case of irradiation under vacuum conditions as compared to 02. Furthermore, the 02 environment reduces the ablation threshold. XRD data reveal that for the 02 environment, new phases （oxides of Ti） are formed. EDS analysis exhibits that after irradiation under vacuum conditions, the percentage of impurity element （A1） is reduced. The irradiation in the 02 environment results in 15% atomic diffusion of oxygen.

关键词： LIPSS ablation threshold incubation coefficient structural modification

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Femtosecond laser induced nanostructuring of zirconium in liquid confined environment

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Chinese Physics B 2017年第1期26卷 310-319页

作者： Nisar Ali shazia bashir Umm-i-Kalsoom m.Shahid Rafique Narjis Begum Wolfgang Husinsky Ali Ajami Chandra S.R.Natahala Laser Laboratories Institute for Applied Physics Vienna University of Technology 1040 Vienna Austria Department of Basic Sciences and Humanities University of Engineering and Technology Lahore Faisalabad Campus Faisalabad Pakistan Laser Laboratories Centre for Advanced Studies m Physics GC University 1-Church Road Lahore Pakistan Department of Physics GC University Kachehri Road Lahore Pakistan Department of Physics Riphah International University Islamahad (Lahore Campus) Lahore Pakistan Department of Physics University of Engineering and Technology Lahore Pakistan Department of Physics COMSATS Institute of Information Technology Islamabad Pakistan

The surface, structural, and mechanical properties of zirconium after irradiation with Ti： sapphire laser（800 nm, 30 fs,1 k Hz） have been investigated. The zirconium targets were exposed for a varying number of laser pulses ranging from 500 to 2000 at a fixed fluence of 3.6 J/cm^2 corresponding to an intensity of 1.2×10^14W/cm^2 in ambient environments of deionized water and propanol. A scanning electron microscope（SEm） was employed to investigate the surface morphology of the irradiated zirconium. The SEm analysis shows the formation of various kinds of features including nanoscale laser induced periodic surface structures（LIPSS）, sponge like surface structure, flakes, conical structures, droplets, pores, and cavities. The energy dispersive x-ray spectroscopy（EDS） analysis exhibits the variation in chemical composition along with an enhanced diffusion of oxygen under both ambient conditions. The crystal structure and phase analyses of the exposed targets were explored by x-ray diffraction（XRD） and Raman spectroscopy techniques, respectively. The XRD analysis confirms the presence of various phases of zirconium hydride and zirconia after ablation in both de-ionized water and propanol. However, excessive hydrides are formed in the case of propanol. The Raman analysis supports the EDS and XRD results. It also reveals the presence of oxides（zirconia） after irradiation in both de-ionized water and propanol *** chemical reactivity of zirconium was significantly improved in the presence of liquids which were accountable for the growth of novel phases and modification in the chemical composition of the irradiated Zr. A nanohardness tester was employed to measure the nanohardness of the laser treated targets. The initial increase and then decrease in nanohardness was observed with an increase in the number of laser pulses in the de-ionized water environment. In the case of propanol,a continuous decrease in hardness was observed.

关键词： ambient environments periodic structure crystallinity synthesis

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Laser-assisted ablation and plasma formation of titanium explored by LIBS,QCm, optical microscopy and SEm analyses along with mechanical modifications under different pressures of Ar and Ne

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Plasma Science and Technology 2023年第3期25卷 181-192页

作者： maryam RIAZ shazia bashir Asma HAYAT Zarish NAZ Centre for Advanced Studies in Physics GC University Lahore

This study deals with the investigation of Nd:YAG laser-assisted ablation and plasma formation of Ti at irradiance of 0.85 GW cm-2 under Ar and Ne environment at various pressures ranging from 10-120 ***-induced breakdown spectroscopy is used to evaluate plasma parameters,whereas quartz crystal microbalance is used for ablation yield *** crater depth is evaluated by optical *** surface features are explored by scanning electron microscope(SEm) analysis and the micro-hardness is measured by a Vickers hardness *** is observed that the plasma parameters are higher in Ar than in Ne,and are strongly correlated with the ablation yield,ablation depth,surface features and hardness of laser-ablated *** parameters increase with increasing the pressure of environmental gases,attain their maxima at 40 Torr for Ar and at 60 Torr for ***,they show a decreasing trend up till a maximum pressure of 120 *** maximum value of the electron temperature(Te) is5480 K,number density(ne) is 1.46 × 1018 cm-3,ablation depth is 184 μm,ablation yield is3.9 × 1015 atoms/pulse and hardness is 300 HV in the case of Ar *** analysis reveals the growth of surface features,such as cones,ridges and pores,whose appearance is more distinct in Ar than Ne and is attributed to temperature,pressure and density gradients along with recoil pressure of the Ti plasma.

关键词： ablation plasma electron temperature electron density laser-induced breakdown spectroscopy surface structures

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Water promoted, microwave-assisted oxidative novel deamination of N-aminoquinazolinones

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Chinese Chemical Letters 2008年第2期19卷 161-165页

作者： m. Arfan Rasool Khan shazia Anjum Shabir Ahmad m. Iqbal Choudhary Institute of Chemical Sciences University of Peshawar Peshawar 25120 Pakistan HEJRIC International Centre for Chemical and Biological Sciences University of Karachi Karachi 75270 Pakistan

A novel deamination of 2-alkyl/aryl 3-amino-4（3H）-quinazolinones series using aqueous KmnO4 under thermal condition and microwave irradiation is described. Compared to thermal condition, significantly higher yields in much shorter times were observed for reactions under microwave irradiation. A plausible mechanism has been proposed for the oxidative water-promoted deamination.

关键词： N-Aminoquinazolinones Oxidative deamination KmnO4 Water microwave irradiation

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A facile synthesis of novel unsymmetrical N-(4-oxo-2-phenyl-3(4H)-quinazolinoyl)-N-(aryl) acetamidines

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Chinese Chemical Letters 2010年第8期21卷 905-910页

作者： Rasool Khan mohammad Arfan Javeed mahmood shazia Anjum m.Iqbal Choudhary Department of Chemistry Abdul Wali Khan UniversityMardan-23200NWFPPakistan Institute of Chemical Sciences University of PeshawarPeshawar-25120Pakistan University of Saskatchewan Department of ChemistrySaskatoon S7N5C9Canada HEJRIC International Center for Chemical and Biological SciencesUniversity of KarachiKarachi-75270Pakistan

A series of novel unsymmetrical N-（4-oxo-2-phenyl-3（4H）-quinazolinoyl）-N-（aryl） acetamidines was synthesized by reacting ethyl（1H）-N-（4-oxo-2-phenylquinazolin-3（4H）-y1）ethanimidoate（2） and suitable reactive aromatic ***＇ determination of the synthesized compounds was carried out using spectroscopic techniques including IR,~1H NmR,and mass spectrometry. Structural effects on reactivity were also studied.

关键词： 3-Amino-2-phenyl-4(3H)-quinazolinone Triethylorthoacetate Unsymmetrical N-(4-oxo-2-phenyl-3(4H)-quinazolinoyl)-N-(aryl) acetamidines

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moisture and Temperature Response of Structural and Lithology based Thermophysical and energy Saving Traits of Limestone using Experimental and Least-Square Fitting methods

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Journal of Thermal Science 2021年第2期30卷 551-561页

作者： Farah Anjum muhammad Yasin Naz Abdul Ghaffar shazia Shukrullah Nasser m AbdEl-Salam Khalid Aref Ibrahim Department of Physics University of AgricultureFaisalabad 38040Pakistan Arriyadh Community College King Saud UniversityArriyadh 11437Saudi Arabia College of engineering Muzahimiyah BranchKing Saud UniversityRiyadh 11451Saudi Arabia Department of Physics College of Arts and SciencesUniversity of JhangJhang 35200Pakistan

Thermophysical analysis of the crustal rocks is important for heat transfer determination and insulation purposes to save energy in *** the presented work,thermophysical properties of four limestones were investigated in dry and moist state under ambient conditions by using a transient plane source method.A thermal constant analyzer was used to raise the sample temperature and to measure the thermal properties in the temperature range of 300 K to 433 *** conductivity and diffusivity were measured by developing a linear relationship between temperature response of TPS (transient plane source) sensor and dimensionless time function through least-square fitting *** experimental observations and predicted thermal conductivity of samples have shown that in-situ observations are important to determine the thermal properties *** effect of temperature on thermal properties of limestone was defined by considering the chemical composition of the samples and associated heat transfer *** thermal conductivity and diffusivity of limestone decreased while specific heat capacity increased with a rise in *** overall findings indicate that the spinoff of this research is useful in studying the reliance of thermophysical properties of rocks on their structures and lithology.

关键词： limestone thermophysical properties transient plane source(TPS) thermal conductivity

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Kaempferol and its derivatives:Biological activities and therapeutic potential

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Asian Pacific Journal of Tropical Biomedicine 2023年第10期13卷 411-420页

作者： shazia Parveen Irshad Ul Haq Bhat Rajeev Bhat Chemistry Department Faculty of ScienceTaibah UniversityYanbu BranchYanbu-46423Saudi Arabia Department of Chemistry College of ScienceUniversity of BahrainP.O.Box 32038Bahrain ERA-Chair for Food(By-)Products Valorisation Technologies Estonian University of Life SciencesTartu-510014EstoniaEU

Kaempferol,a natural plant-origin flavonoid,exhibits therapeutic anti-inflammatory,antioxidant,anticancer,antidiabetic,and neuroprotective *** acts within several distinct mechanisms like apoptotic induction in cancer cells,enzymatic inhibition,signalling pathway inhibition,and downregulation in cell viability during the G2/m phase of cell *** review summarizes the therapeutic effects of kaempferol against several health *** recent progress on kaempferol obtained from fruits and vegetables as an antioxidant,anti-inflammatory,anticancer,antidiabetic,and neuroprotective agent and its mechanisms of action are also *** addition,kaempferol has been reported to be present in wastes and byproducts from post-fruit and vegetable ***,a paradigm shift towards valorizing fruits and vegetable industrial wastes/byproducts to obtain bioactive kaempferol can support the circular economy pillar for generating wealth from waste and for finding a sustainable alternative source.

关键词： Kaempferol Therapeutic effects Bioactivities Fruits and vegetable wastes Sustainable alternative sources

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energy and flux measurements of laser-induced silver plasma ions by using Faraday cup

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Plasma Science and Technology 2021年第8期23卷 188-198页

作者： muhammad Usman Aslam BHATTI shazia bashir Asma HAYAT Khaliq mAHmOOD Rana AYUB mubashir JAVED muhammad Shahzad KHAN Centre for Advanced Studies in Physics(CASP) GC UniversityLahore 54000Pakistan

Silver(Ag)plasma has been generated by employing Nd:YAG laser(532 nm,6 ns)laser *** energy and flux of ions have been evaluated by using Faraday cup(FC)using time of flight(TOF)*** dual peak signals of fast and slow Ag plasma ions have been *** energy and flux of fast and slow ions tend to increase with increasing irradiance from 7 GW cm-2 to 17.9 GW cm-2 at all distances of FC from the target *** a decreasing trend of energies and flux of ions has been observed with increasing distance of FC from the *** maximum value of flux of the fast component is21.2×10^(10) cm^(-2),whereas for slow ions the maximum energy and flux values are 8.8 keV,8.2×10^(10) cm^(-2) *** the analysis of plume expansion dynamics,the angular distribution of ion flux measurement has also been *** overall analysis of both spatial and angular distributions of Ag ions revealed that the maximum flux of Ag plasma ions has been observed at an optimal angle of~15°.In order to confirm the ion acceleration by ambipolar field,the self-generated electric field(SGEF)measurements have also been performed by electric probe;these SGEF measurements tend to increase by increasing laser *** maximum value of 232 V m^(-1) has been obtained at a maximum laser irradiance of 17.9 GW cm^(-2).

关键词： laser ablation laser-induced plasma ions Faraday cup time of flight measurements self-generated electric field angular distribution

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Is tumor cell specificity distinct from tumor selectivity in vivo?A quantitative NIR molecular imaging analysis of nanoliposome targeting

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Nano Research 2021年第5期14卷 1344-1354页

作者： Girgis Obaid Kimberley Samkoe Kenneth Tichauer shazia Bano Yeonjae Park Zachary Silber Sassan Hodge Susan Callaghan mina Guirguis Srivalleesha mallidi Brian Pogue Tayyaba Hasan Wellman Center for Photomedicine Massachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA Department of Bioengineering University of Texas at DallasRichardsonTX75080USA Thayer School of engineering Dartmouth CollegeHanoverNH037551USA Armour College of engineering Illinois Institute of TechnologyChicagoIL60616USA Division of Health Sciences and Technology Harvard University and Massachusetts Institute of TechnologyCambridgeMA02139USA

The significance and ability for receptor targeted nanoliposomes(tNLs)to bind to their molecular targets in solid tumors in vivo has been questioned,particularly as the efficiency of their tumor accumulation and selectivity is not always predictive of their efficacy or molecular *** study presents,for the first time,in situ near-infrared(NIR)molecular imaging-based quantitation of the in vivo specificity of tNLs for their target receptors,as opposed to tumor selectivity,which includes influences of enhanced tumor permeability and *** show that neither tumor delivery nor selectivity(tumor-to-normal ratio)of cetuximab and IRDye conjugated tNLs correlate with epidermal growth factor receptor(EGFR)expression in U251,U87,and 9L tumors,and in fact underrepresent their imaging-derived molecular specificity by up to 94.2%.Conversely,their in vivo specificity,which we quantify as the concentration of tNL-reported tumor EGFR provided by NIR molecular imaging,correlates positively with EGFR expression levels in vitro and ex vivo(Pearson’s r=0.92 and 0.96,respectively).This study provides a unique opportunity to address the problematic disconnect between tNL synthesis and in vivo *** findings encourage their continued adoption as platforms for precision medicine,and facilitates intelligent synthesis and patient customization in order to improve safety profiles and therapeutic outcomes.

关键词： molecular recognition receptors nanoparticles specificity cancer

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Assessment of Spatial Variability of Soil Fertility Parameters Using Geospatial Techniques in Temperate Himalayas

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International Journal of Geosciences 2017年第10期8卷 1251-1263页

作者： shazia Ramzan mushtaq A. Wani m. Auyoub Bhat S.K. University of Agricultural Sciences and Technology of Kashmir Shalimar India

Knowledge of spatial variability of soil properties is important in precision agriculture as well as site specific nutrient management. This paper addressed the spatial distribution characteristics of organic matter (Om), pH, available nitrogen (AvN), available phosphorus (AvP), available potassium (AvK) and available sulphur (AvS) in Research farm of SKUAST-K, Shalimar, Srinagar. A total of seventy seven (77) soil samples were collected in a systematic grid design using geographical positioning system (GPS). Each grid was specified at a fixed distance of 50 × 50 m2. The results showed that soil organic matter and S was distributed normally while as the three soil macronutrients (AvN, AvP and AvK) and soil pH followed log normal distribution. Soil available phosphorus had a highest coefficient of variation (56.87%) and the soil pH (7.06%) the lowest. All the soil macronutrients were found in medium range except sulphur which was found deficient in whole of the research farm. The experimental semivariogram of the log-transformed data of soil available phosphorus, potassium, sulphur, soil pH and normally distributed soil organic matter was fitted to exponential model. Gaussian model was found to be the best fit for experimental semivariogram of soil available nitrogen. Experimental semivariogram results indicated a moderate degree of spatial dependence for soil organic matter, available potassium and sulphur, soil pH and weak degree of spatial dependence for soil available nitrogen and phosphorus. Using such analyses, it is possible to plan appropriate soil management practices, including fertilization for agricultural production and environmental protection.

关键词： Geostatistics Ordinary Kriging Spatial Variability Soil Fertility

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