Physical Properties of Cu Doped ZnO Nanocrystiline Thin Films

 تم تصنيع اغشية أكسيد الزنك البلورية النانوية المطعمة بالنحاس  (ZnO: Cu)بتراكيز مختلفة .. تم ترسيب (0 ، 6 ، 9 ، 12 ، 18) ٪ من النحاس على ركيزة زجاجية باستخدام تقنية ترسب الليزر النبضي (PLD) وبتراكيز مختلفة. وقد تم توصيف بلورات ZnO: Cu   النانوية بواسطة أطياف UV-VIS ، حيود الأشعة السينية (XRD) ومجهر القوة الذرية (AFM). تم استخدام التحليل الطيفي للأشعة المرئية وفوق البنفسجية لتحديد نوع وقيمة فجوة الطاقة الضوئية ، بينما تم استخدام حيود الأشعة السينية لفحص الهيكل وتحديد حجم البلورات. تم استخدام مجاهر القوة الذرية لدراسة تكوين سطح المواد المترسبة. تم استخدام التحليل الطيفي للأشعة المرئية وفوق البنفسجية لتحديد نوع وقيمة فجوة الطاقة الضوئية. Thin films of ZnO nano crystalline doped with different concentrations (0, 6, 9, 12, and 18 )wt. % of copper were deposited on a glass substrate via pulsed laser deposition method (PLD). The properties of ZnO: Cu thin-nanofilms have been studied by absorbing UV-VIS, X-ray diffraction (XRD) and atomic force microscopes (AFM). UV-VIS spectroscopy was used to determine the type and value of the optical energy gap, while X-ray diffraction was used to examine the structure and determine the size of the crystals.  Atomic force microscopes were used to study the surface formation of precipitated materials. The UV-VIS spectroscopy was used to determine the type and value of the optical energy gap

Effect of the Concentration of Copper on the Properties of Copper Sulfide Nanostructure

      تم تحضير كبريتيد النحاس النانوي (  CuS NPs )  بتفاعل بسيط بين نترات النحاس بتركيزات مختلفة (10. و 30. و 50.) ملي مول والثايوريا والماء كمذيب بأستخدام الطريقة الكيميائية. تم ترسيب المساحيق النانوية المحضرة على ارضية زجاجية بتقنية الصب وبدرجة حرارة 60  درجة مئوية. تم توصيف الأغشية النانوية الناتجة بواسطة حيود الأشعة السينية (XRD) ، مجهر القوة الذرية (AFM) ، ومجهر الالكتروني الماسح (SEM ),وأطياف الأشعة فوق البنفسجية – المرئية. أظهرت أنماط XRD أن جميع العينات كانت عبارة عن تركيب سداسي لكبريتيد النحاس وبمتوسط ​​أحجام بلورية 14.07 - 16.51 نانومتر. بينت صور AFM اغلب الجسيمات كانت كروية الشكل وبعضها اسطوانية تقريبًا وبمعدل حجم قطر 49.11-90.64  نانومتر. من دراسة امتصاص الأشعة فوق البنفسجية ، لوحظ أن حافة الامتصاص تزداد لجميع الأغشية الرقيقة المرسبة تبعا لزيادة التركيز، مما يؤدي إلى نقصان في فجوة النطاق من 3.5 إلى 3.0 الكترون فولت لـلتراكيز( 0.1  و 0.5 ) ملي مول على التوالي.Nanoparticles of copper sulfide have been prepared by simple reaction between using copper nitrate with different concentrations ratio 0.1, 0.3, and 0.5 mM, thiourea by a simple chemical route. The prepared Nano powders have been deposited onto glass substrates by casting method at 60°C. The structure of the product Nano- films has been studied by x-ray diffraction, where the patterns showed that all the samples have a hexagonal structure of covellite copper sulfide with the average crystalline sizes 14.07- 16.51 nm. The morphology has been examined by atomic force microscopy, and field emission scan electron microscopy. The AFM images showed particles with almost spherical and rod shapes with average diameter sizes of 49.11- 90.64 nm. From the UV-Vis absorption studies, it has been noted that the increased absorption edge for all thin films leads to decreases in the energy gap of 3.5 to 3.0 eV for 1mM and 5mM respectively

Effect the Temperature on Structure and Optical Properties for ZnS nanostructure Thin Film

ZnS nanocrystalline thin films by different temperature of reaction were prepared by chemical bath deposition using thiourea and zinc acetate as S2– and Zn2+ source. The optical absorption studies in the wavelength range 200–1100 nm show that band gap energy of samples 3.75 and 4.0 eV for different temperature reaction condition. The refractive index was estimated within the visible wavelength at 623 nm, it was 2.04 for sample 1 and its value will increase for sample 2 to be 2.55. The room temperature photoluminescence spectra of the films showed two peaks for all samples. We assigned the first peak due to band gap transitions while the latter was due to zinc vacancy in the films. Structural analysis using atomic force microscopy shows that the grain size for films were 73.2 and 87.34 nm. X-ray diffraction analysis indicates that both of them formed in the reaction bath have cubic zinc blende structure .The structural estimation shows variation in grain size 7nm and 20nm with different temperature reaction

Oxygen Isotope Variability within Nautilus Shell Growth Bands

Nautilus is often used as an analogue for the ecology and behavior of extinct externally shelled cephalopods. Nautilus shell grows quickly, has internal growth banding, and is widely believed to precipitate aragonite in oxygen isotope equilibrium with seawater. Pieces of shell from a wild-caught Nautilus macromphalus from New Caledonia and from a Nautilus belauensis reared in an aquarium were cast in epoxy, polished, and then imaged. Growth bands were visible in the outer prismatic layer of both shells. The thicknesses of the bands are consistent with previously reported daily growth rates measured in aquarium reared individuals. In situ analysis of oxygen isotope ratios using secondary ion mass spectrometry (SIMS) with 10 μm beam-spot size reveals inter- and intra-band δ18O variation. In the wild-caught sample, a traverse crosscutting 45 growth bands yielded δ18O values ranging 2.5‰, from +0.9 to -1.6 ‰ (VPDB), a range that is larger than that observed in many serial sampling of entire shells by conventional methods. The maximum range within a single band (~32 μm) was 1.5‰, and 27 out of 41 bands had a range larger than instrumental precision (±2 SD = 0.6‰). The results from the wild individual suggest depth migration is recorded by the shell, but are not consistent with a simple sinusoidal, diurnal depth change pattern. To create the observed range of δ18O, however, this Nautilus must have traversed a temperature gradient of at least ~12°C, corresponding to approximately 400 m depth change. Isotopic variation was also measured in the aquarium-reared sample, but the pattern within and between bands likely reflects evaporative enrichment arising from a weekly cycle of refill and replacement of the aquarium water. Overall, this work suggests that depth migration behavior in ancient nektonic mollusks could be elucidated by SIMS analysis across individual growth bands

Effect of Annealing Temperature on Physical Properties of Indium Doped Cadmium Oxide Thin Films

     Nanostructured indium doped CdO thin films were prepared by spray pyrolysis on glass substrate and annealed at 200-400 áµ’C for 1 hour. The structural, optical, and electrical properties of prepared films were studied using different techniques such as optical transmission, photoluminescence, X-ray diffraction, and Hall measurement. X-ray analysis shows that the In doped CdO films are preferentially orientated along (111) crystallographic directions. Increasing of annealing temperature increases the films packing density and reorient the crystallites along (1 1 1) plane.  The optical transmissions of all annealed films decreased with increasing annealing temperature. An increasing in the absorbance and photoluminescence spectra with increasing annealing temperature was denoted in all films. The band gap value of CdO:4%In equals to 2.5 eV and it decreases with annealing temperature and reaches of 2.45 eV for 400°C. The resistivity of annealed films decreased as annealing temperature increased. While high conductivity achieved in the present study is found to be 11.37 ×102 (Ω.cm)-1 for annealing at 400°C.Â

Microbial composition analyses by 16S rRNA sequencing: A proof of concept approach to provenance determination of archaeological ochre

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Many archaeological science studies use the concept of “provenance”, where the origins of cultural material can be determined through physical or chemical properties that relate back to the origins of the material. Recent studies using DNA profiling of bacteria have been used for the forensic determination of soils, towards determination of geographic origin. This manuscript presents a novel approach to the provenance of archaeological minerals and related materials through the use of 16S rRNA sequencing analysis of microbial DNA. Through the microbial DNA characterization from ochre and multivariate statistics, we have demonstrated the clear discrimination between four distinct Australian cultural ochre sites

Creation of Surge Capacity by Early Discharge of Hospitalized Patients at Low Risk for Untoward Events

Objectives: US hospitals are expected to function without external aid for up to 96 hours during a disaster; however, concern exists that there is insufficient capacity in hospitals to absorb large numbers of acute casualties. The aim of the study was to determine the potential for creation of inpatient bed surge capacity from the early discharge (reverse triage) of hospital inpatients at low risk of untoward events for up to 96 hours. Methods: In a health system with 3 capacity-constrained hospitals that are representative of US facilities (academic, teaching affiliate, community), a variety (N = 50) of inpatient units were prospectively canvassed in rotation using a blocked randomized design for 19 weeks ending in February 2006. Intensive care units (ICUs), nurseries, and pediatric units were excluded. Assuming a disaster occurred on the day of enrollment, patients who did not require any (previously defined) critical intervention for 4 days were deemed suitable for early discharge. Results: Of 3491 patients, 44% did not require any critical intervention and were suitable for early discharge. Accounting for additional routine patient discharges, full use of staffed and unstaffed licensed beds, gross surge capacity was estimated at 77%, 95%, and 103% for the 3 hospitals. Factoring likely continuance of nonvictim emergency admissions, net surge capacity available for disaster victims was estimated at 66%, 71%, and 81%, respectively. Reverse triage made up the majority (50%, 55%, 59%) of surge beds. Most realized capacity was available within 24 to 48 hours. Conclusions: Hospital surge capacity for standard inpatient beds may be greater than previously believed. Reverse triage, if appropriately harnessed, can be a major contributor to surge capacity

Detection of Vibrio cholerae and Acanthamoeba species from same natural water samples collected from different cholera endemic areas in Sudan

<p>Abstract</p> <p>Background</p> <p><it>Vibrio cholerae </it>O1 and <it>V. cholerae </it>O139 infect humans, causing the diarrheal and waterborne disease cholera, which is a worldwide health problem. <it>V. cholerae </it>and the free-living amoebae <it>Acanthamoeba </it>species are present in aquatic environments, including drinking water and it has shown that <it>Acanthamoebae </it>support bacterial growth and survival. Recently it has shown that <it>Acanthamoeba </it>species enhanced growth and survival of <it>V. cholerae </it>O1 and O139. Water samples from different cholera endemic areas in Sudan were collected with the aim to detect both <it>V. cholerae </it>and <it>Acanthamoeba </it>species from same natural water samples by polymerase chain reaction (PCR).</p> <p>Findings</p> <p>For the first time both <it>V. cholerae </it>and <it>Acanthamoeba </it>species were detected in same natural water samples collected from different cholera endemic areas in Sudan. 89% of detected <it>V. cholerae </it>was found with <it>Acanthamoeba </it>in same water samples.</p> <p>Conclusions</p> <p>The current findings disclose <it>Acanthamoedae </it>as a biological factor enhancing survival of <it>V. cholerae </it>in nature.</p

Predation upon Hatchling Dinosaurs by a New Snake from the Late Cretaceous of India

A new snake from Upper Cretaceous rocks in India is found with hatchling sauropod dinosaurs, demonstrating that large, gape-limited snakes were probably capable of taking in moderate-sized vertebrate prey

Regional Environmental Breadth Predicts Geographic Range and Longevity in Fossil Marine Genera

Geographic range is a good indicator of extinction susceptibility in fossil marine species and higher taxa. The widely-recognized positive correlation between geographic range and taxonomic duration is typically attributed to either accumulating geographic range with age or an extinction buffering effect, whereby cosmopolitan taxa persist longer because they are reintroduced by dispersal from remote source populations after local extinction. The former hypothesis predicts that all taxa within a region should have equal probabilities of extinction regardless of global distributions while the latter predicts that cosmopolitan genera will have greater survivorship within a region than endemics within the same region. Here we test the assumption that all taxa within a region have equal likelihoods of extinction.We use North American and European occurrences of marine genera from the Paleobiology Database and the areal extent of marine sedimentary cover in North America to show that endemic and cosmopolitan fossil marine genera have significantly different range-duration relationships and that broad geographic range and longevity are both predicted by regional environmental breadth. Specifically, genera that occur outside of the focal region are significantly longer lived and have larger geographic ranges and environmental breadths within the focal region than do their endemic counterparts, even after controlling for differences in sampling intensity. Analyses of the number of paleoenvironmental zones occupied by endemic and cosmopolitan genera suggest that the number of paleoenvironmental zones occupied is a key factor of geographic range that promotes genus survivorship.Wide environmental tolerances within a single region predict both broad geographic range and increased longevity in marine genera over evolutionary time. This result provides a specific driving mechanism for the spatial and temporal distributions of marine genera at regional and global scales and is consistent with the niche-breadth hypothesis operating on macroevolutionary timescales