LIGHT MANIPULATION AND STRUCTURING VIA NANOFABRICATED FLAT METASURFACES

Ph.DDOCTOR OF PHILOSOPH

Integration and Analysis of Resource Inventory Data for Risk Assessments of Environmental Contamination in Mixed Use Landscapes in Pakistan

This paper examines the various metals that are associated with land contamination for instances arsenic, cadmium, lead, chromium, nickel, and mercury that are well known as the ingredient of contamination of the ecology in the region where there is a high rate of anthropogenic burden. The study investigates land contamination in Pakistan's context. The researches have used the quantitative method to analyze the most recent literature available on the land contamination of Pakistan following funnel approach. The three main steps followed to analyze are first, assessment of the site initially, secondly, assessment of the exposure of the contaminated site that also contains a survey of few places and the amount of contamination found and lastly, remediation of the site. The finding revealed that the contamination in Pakistan is both men made as well due to the terrain they belong to that contains various anthropogenic elements, which are harmful to live beings. Additionally, it is evident that the different elements, which can cause soil contamination, are higher in many places in Pakistan than the standard or tolerable rate mentioned by WHO and other survey board. Lastly, the paper confirms that the pollution can be reduced only if there is a reduction in the man made cause of the land contamination such as oil spill and other industrial emissions that constitute most of Pakistan’s land contamination

Integration and Analysis of Resource Inventory Data for Risk Assessments of Environmental Contamination in Mixed Use Landscapes in Pakistan

This paper examines the various metals that are associated with land contamination for instances arsenic, cadmium, lead, chromium, nickel, and mercury that are well known as the ingredient of contamination of the ecology in the region where there is a high rate of anthropogenic burden. The study investigates land contamination in Pakistan's context. The researches have used the quantitative method to analyze the most recent literature available on the land contamination of Pakistan following funnel approach. The three main steps followed to analyze are first, assessment of the site initially, secondly, assessment of the exposure of the contaminated site that also contains a survey of few places and the amount of contamination found and lastly, remediation of the site. The finding revealed that the contamination in Pakistan is both men made as well due to the terrain they belong to that contains various anthropogenic elements, which are harmful to live beings. Additionally, it is evident that the different elements, which can cause soil contamination, are higher in many places in Pakistan than the standard or tolerable rate mentioned by WHO and other survey board. Lastly, the paper confirms that the pollution can be reduced only if there is a reduction in the man made cause of the land contamination such as oil spill and other industrial emissions that constitute most of Pakistan’s land contamination

Efficacy of Phytochemicals of Cassia Angustifolia in Chronic Myeloid Leukaemia – An In-silico Analysis

Objective: To discover the compounds of Cassia having activity against the BCR-ABL fusion protein involved in the pathogenesis of CML and to compare it with previously developed inhibitor, nilotinib using in-silico molecular docking. Methodology: The 3D structure of Human BCR-ABL fusion protein was obtained from PDB (RSCB). The SMILES and Chemical Structures of the ligands were obtained from PubChem. They were prepared in Mol SDF format by the Chem Bio Draw and then converted to PDBQT format using PyRx tool for generating the atomic coordinates for molecular docking.  Molecular docking of Nilotinib, Quercimeritin, and Scutellarein with Human ABL Kinase was performed using Autodock4. The ADMET properties were described using Swiss ADME, a web-based tool. Results: All the three compounds under study bind and make stable complexes with wild-type BCR ABL with the global energies of -12.46, -16.17kCal/mol and -15.41kCal/mol for Nilotinib Scutellarein and Quercimeritin respectively which means that these compounds can act as selective inhibitors of BCR-ABL fusion protein. Quercimeritin, also form Hydrogen bonds with GLU 286 and Asp 381, Conclusion: The binding energies of the phytochemicals of Cassia are higher in comparison with Nilotinib which has a binding energy of -12.46kCal/mol which suggests a better inhibitory potential of these compounds. Quercimeritin also forms Hydrogen bonds with Glutamine 286 and Aspartate 381, hence its potential to be a potent inhibitor of the BCR- ABL fusion protein is more promising Nilotinib. Further in vitro and in vivo studies are suggested to elaborate the anti-neoplastic potential of Quercimeritin in CML

Thermally robust ring-shaped chromium perfect absorber of visible light

A number of light-absorbing devices based on plasmonic materials have been reported, and their device efficiencies (or absorption) are high enough to be used in real-life applications. Many light-absorbing applications such as thermophotovoltaics and energy-harvesting and energy-sensing devices usually require high-temperature durability; unfortunately, noble metals used for plasmonics are vulnerable to heat. As an alternative, refractory plasmonics has been introduced using refractory metals such as tungsten (3422 degrees C) and transition metal nitrides such as titanium nitride (2930 degrees C). However, some of these materials are not easy to handle for device fabrications owing to their ultra-high melting point. Here, we propose a light absorber based on chromium (Cr), which is heat tolerant due to its high melting temperature (1907 degrees C) and is compatible with fabrication using conventional semiconductor manufacturing processes. The fabricated device has >95% average absorption of visible light (500-800 nm) independent of polarization states. To verify its tolerance of heat, the absorber was also characterized after annealing at 600 degrees C. Because of its compactness, broadband operational wavelength, and heat tolerance, this Cr perfect absorber will have applications in high-temperature photonic devices such as solar thermophotovoltaics.111Ysciescopu

A highly efficient broadband multi-functional metaplate

Due to the considerable potential of ultra-compact and highly integrated meta-optics, multi-functional metasurfaces have attracted great attention. The mergence of nanoimprinting and holography is one of the fascinating study areas for image display and information masking in meta-devices. However, existing methods rely on layering and enclosing, where many resonators combine various functions effectively at the expense of efficiency, design complication, and complex fabrication. To overcome these limitations, a novel technique for a tri-operational metasurface has been suggested by merging PB phase-based helicity-multiplexing and Malus\u27s law of intensity modulation. To the best of our knowledge, this technique resolves the extreme-mapping issue in a single-sized scheme without increasing the complexity of the nanostructures. For proof of concept, a multi-functional metasurface built of single-sized zinc sulfide (ZnS) nanobricks is developed to demonstrate the viability of simultaneous control of near and far-field operations. The proposed metasurface successfully verifies the implementation of a multi-functional design strategy with conventional single-resonator geometry by reproducing two high-fidelity images in the far field and projecting one nanoimprinting image in the near field. This makes the proposed information multiplexing technique a potential candidate for many high-end and multi-fold optical storage, information-switching, and anti-counterfeiting applications

Tungsten-based ultrathin absorber for visible regime

Utilizing solar energy requires perfect absorption of light by the photovoltaic cells, particularly solar thermophotovoltaics (STPVs), which can be eventually converted into useful electrical energy. Ultrathin nanostructures, named metasurfaces, provide an intriguing platform to develop the miniaturized solar energy absorbers that can find potential applications in integrated photonics, optical sensing, color imaging, thermal imaging and electromagnetic shielding. Therefore, the quest of novel materials and designs to develop highly efficient absorbers at minuscule scale is an open topic. In this paper, novel absorbers using tungsten-metasurface are developed which give ultrahigh absorbance over a wide frequency spectrum. The proposed designs are two-dimensional, polarization insensitive, broadband and are predicted to give better response under high temperatures ascribed to high melting point of tungsten i.e. 3422 degrees C. Amongst these designs, cross alignment is found optimum for tungsten, because it is impedance matched with the free space for visible spectrum. This cross arrangement is further tweaked by changing width, height and length resulting in 7 different optimized solutions giving an average absorbance greater than 98%. One, amongst these solutions, gave a maximum average absorbance of 99.3%.114Nsciescopu

Infective agents in diabetic foot ulcers and their sensitivity patterns

Background: Diabetic-foot syndrome is a difficult & debilitating complication of inadequately regulated Diabetes Mellitus. Attributed to neural & vascular pathology, the condition is further potentiated by glycemic healing impairment.  A wide array of microorganisms have been implicated & sensitivity-guided antibiotics are essential to save both limb as well as to minimize rampant microbial resistance. Present study aims to determine the culture & sensitivity pattern of bacteria in stated cohort of patients at a Surgical Unit. Materials & Methods: This prospective cohort study was conducted over a period of 1 year-duration at a tertiary-care-Hospital. All patients presenting with diabetic-foot who had not been subjected to empiric antibiotic-therapy were enrolled. Demographic & lesion-based variables were studied and the Culture & Sensitivity pattern was evaluated and statistically analyzed. Results:100 patients were included in the study,of which 80 were male (mean-age 60.8±12.7 years) & rest female (mean-age 58.4±11.3-years).35% cultures yielded no growth. Remaining cases showed following pathogens in descending order of incidence. Maximal sensitivity was also reported as mentioned. 1) Staphylococcus-aureus & Klebseilla-Pneumoenae– Piperacillin/Tazobactam,2) Pseudomonas-Aerugionas-Cefotaxime,3)E-coli–Amikacin& Sulbactam,4) Proteus -Gentamicin, 5) Streptococci– Amikacin and 6) Bacteroides – Cefoperazone & Aztreonam. Of 71 cases, 70  had aerobic-organisms isolates & only 1 had anaerobic-isolate.   Conclusions: Six pathogens were identified in present study of which Staphylococcus-Aureus was the most prevalent as well as the most resistant. Streptococci & Gram-negative Organisms were observed in remaining cases. While formulation of an adequate antibiotic regime is rendered difficult by resistance & mixed infections, targeted antibiotic administration is decisively crucial to achieve optimal & timely outcome in diabetic foot. &nbsp

Comparative Study of the Attitudes of Rural and Urban Punjabi Society towards Caste Stereotypes in Punjabi Language

This study compares attitudes of rural/urban population of Punjab (Pakistan) towards caste-stereotypes in Punjabi language. The data were collected from District Vehari of southern Punjab including its two adjacent sub-divisions Burewla and Mailsi through questionnaire and interviews; and analyzed using SPSS. The results reveal that there is considerable difference among the attitudes of urban/rural population regarding beliefs and foundations of the caste-stereotypes and their impacts on social life. Besides, people living in rural areas are more prone to using caste-stereotypes than their urban counterparts. Similar trend is observed in the effect of caste-stereotypes on their social relations. DOI: 10.5901/mjss.2015.v6n1s1p62