Roles for SOF in a Staggering Nigeria

DTIC Science & Technology

2009-04-01

languages and approximately 350 ethno-linguistic groups, Nigeria can indubitably be dubbed a cultural patchwork. Three dominant groups, the Ibo, Yoruba ...critical factors ................................................................................................................ 4 A cultural patchwork...continue to be the U.S. military force of choice for operations and exercises within Africa.”10 Culturally attuned, experienced in working with

Constructing Knowledge in a New World.

ERIC Educational Resources Information Center

Solis, Ed

2002-01-01

Considers how the events of September 11th made fear drive students away from acceptance and interest in what was before a cultural learning experience. Discusses students' reactions to Chinua Achebe's novel "Things Fall Apart," which depicts colonization from the point of the Ibo people. Concludes that curriculum may need to address…

Nigeria: Hydrocarbon Curse Fueling Instability in Niger Delta

DTIC Science & Technology

2010-03-15

Christians and Muslims. 12 The largest ethnic groups are the Hausa-Fulani in theNorth, the Ibo in the Southeast, and the Yoruba in the Southwest. 13 Nigeria...0). AllAfrica.com. "Nigeria: The Fading Culture of Party System in Nigeria." http://allafrica.com/stories/200803190577.htm I (accessed February 9

The Academic Impact of Enrollment in International Baccalaureate Diploma Programs: A Case Study of Chicago Public Schools

ERIC Educational Resources Information Center

Saavedra, Anna Rosefsky

2014-01-01

Background: In schools accredited as "IB World Schools" by the International Baccalaureate Organization (IBO), teachers use IB curriculum and pedagogy to teach a range of courses that are intended to prepare IB-enrolled students for college. Over the past 18 years, the number of U.S. schools that implement IB programs has increased…

Effect of postoperative peroxide bleaching on the marginal seal of composite restorations bonded with self-etch adhesives.

PubMed

Roubickova, A; Dudek, M; Comba, L; Housova, D; Bradna, P

2013-01-01

The aim of this study was to determine the effect of peroxide bleaching on the marginal seal of composite restorations bonded with several adhesive systems. Combined cylindrical Class V cavities located half in enamel and half in dentin were prepared on the buccal and lingual surfaces of human molars. The cavities were bonded with the self-etch adhesives Clearfil SE-Bond (CLF), Adper Prompt (ADP), and iBond (IBO) and an etch-and-rinse adhesive Gluma Comfort Bond (GLU) and restored with a microhybrid composite Charisma. Experimental groups were treated 25 times for eight hours per day with a peroxide bleaching gel Opalescence PF 20, while the control groups were stored in distilled water for two months and then subjected to a microleakage test using a dye penetration method. Scanning electron microscopy was used to investigate the etching and penetration abilities of the adhesives and morphology of debonded restoration-enamel interfaces after the microleakage tests. Statistical analyses were performed using nonparametric Kruskal-Wallis, Mann-Whitney, and Wilcoxon tests at p=0.05. The microleakage of all GLU groups was low and not significantly affected by peroxide bleaching. Low microleakage was recorded for CLF control groups, but after bleaching, a small but significant increase in microleakage at the enamel margin indicated its sensitivity to peroxide bleaching. For ADP and IBO control groups, the microleakage at the enamel margins was significantly higher than for GLU and CLF and exceeded that at the dentin margins. Bleaching did not induce any significant changes in the microleakage. Electron microscopy analysis indicated that in our experimental setup, decreased adhesion and mechanical resistance of the ADP- and IBO-enamel interfaces could be more important than the chemical degradation effects induced by the peroxide bleaching gel.

Evidence for Time-of-Day Dependent Effect of Neurotoxic Dorsomedial Hypothalamic Lesions on Food Anticipatory Circadian Rhythms in Rats

PubMed Central

Landry, Glenn J.; Kent, Brianne A.; Patton, Danica F.; Jaholkowski, Mark; Marchant, Elliott G.; Mistlberger, Ralph E.

2011-01-01

The dorsomedial hypothalamus (DMH) is a site of circadian clock gene and immediate early gene expression inducible by daytime restricted feeding schedules that entrain food anticipatory circadian rhythms in rats and mice. The role of the DMH in the expression of anticipatory rhythms has been evaluated using different lesion methods. Partial lesions created with the neurotoxin ibotenic acid (IBO) have been reported to attenuate food anticipatory rhythms, while complete lesions made with radiofrequency current leave anticipatory rhythms largely intact. We tested a hypothesis that the DMH and fibers of passage spared by IBO lesions play a time-of-day dependent role in the expression of food anticipatory rhythms. Rats received intra-DMH microinjections of IBO and activity and body temperature (T b) rhythms were recorded by telemetry during ad-lib food access, total food deprivation and scheduled feeding, with food provided for 4-h/day for 20 days in the middle of the light period and then for 20 days late in the dark period. During ad-lib food access, rats with DMH lesions exhibited a lower amplitude and mean level of light-dark entrained activity and T b rhythms. During the daytime feeding schedule, all rats exhibited food anticipatory activity and T b rhythms that persisted during 2 days without food in constant dark. In some rats with partial or total DMH ablation, the magnitude of the anticipatory rhythm was weak relative to most intact rats. When mealtime was shifted to the late night, the magnitude of the food anticipatory activity rhythms in these cases was restored to levels characteristic of intact rats. These results confirm that rats can anticipate scheduled daytime or nighttime meals without the DMH. Improved anticipation at night suggests a modulatory role for the DMH in the expression of food anticipatory activity rhythms during the daily light period, when nocturnal rodents normally sleep. PMID:21912674

Image-based overlay measurement using subsurface ultrasonic resonance force microscopy

NASA Astrophysics Data System (ADS)

Tamer, M. S.; van der Lans, M. J.; Sadeghian, H.

2018-03-01

Image Based Overlay (IBO) measurement is one of the most common techniques used in Integrated Circuit (IC) manufacturing to extract the overlay error values. The overlay error is measured using dedicated overlay targets which are optimized to increase the accuracy and the resolution, but these features are much larger than the IC feature size. IBO measurements are realized on the dedicated targets instead of product features, because the current overlay metrology solutions, mainly based on optics, cannot provide sufficient resolution on product features. However, considering the fact that the overlay error tolerance is approaching 2 nm, the overlay error measurement on product features becomes a need for the industry. For sub-nanometer resolution metrology, Scanning Probe Microscopy (SPM) is widely used, though at the cost of very low throughput. The semiconductor industry is interested in non-destructive imaging of buried structures under one or more layers for the application of overlay and wafer alignment, specifically through optically opaque media. Recently an SPM technique has been developed for imaging subsurface features which can be potentially considered as a solution for overlay metrology. In this paper we present the use of Subsurface Ultrasonic Resonance Force Microscopy (SSURFM) used for IBO measurement. We used SSURFM for imaging the most commonly used overlay targets on a silicon substrate and photoresist. As a proof of concept we have imaged surface and subsurface structures simultaneously. The surface and subsurface features of the overlay targets are fabricated with programmed overlay errors of +/-40 nm, +/-20 nm, and 0 nm. The top layer thickness changes between 30 nm and 80 nm. Using SSURFM the surface and subsurface features were successfully imaged and the overlay errors were extracted, via a rudimentary image processing algorithm. The measurement results are in agreement with the nominal values of the programmed overlay errors.

The Cultural Impact upon Human Struggle for Social Existence in Chinua Achebe's "Things Fall Apart"

ERIC Educational Resources Information Center

El-Dessouky, Mohamed Fawzy

2010-01-01

This paper aims at introducing an insight into the nature of cultural conflict as depicted in Chinua Achebe's "Things Fall Apart." This study shows how the African black culture represented by Ibo tribe comes into disagreement with the white one imposed by the British imperialism. The greatness of Achebe lies in the vivid description of…

Diffraction-based overlay metrology for double patterning technologies

NASA Astrophysics Data System (ADS)

Dasari, Prasad; Korlahalli, Rahul; Li, Jie; Smith, Nigel; Kritsun, Oleg; Volkman, Cathy

2009-03-01

The extension of optical lithography to 32nm and beyond is made possible by Double Patterning Techniques (DPT) at critical levels of the process flow. The ease of DPT implementation is hindered by increased significance of critical dimension uniformity and overlay errors. Diffraction-based overlay (DBO) has shown to be an effective metrology solution for accurate determination of the overlay errors associated with double patterning [1, 2] processes. In this paper we will report its use in litho-freeze-litho-etch (LFLE) and spacer double patterning technology (SDPT), which are pitch splitting solutions that reduce the significance of overlay errors. Since the control of overlay between various mask/level combinations is critical for fabrication, precise and accurate assessment of errors by advanced metrology techniques such as spectroscopic diffraction based overlay (DBO) and traditional image-based overlay (IBO) using advanced target designs will be reported. A comparison between DBO, IBO and CD-SEM measurements will be reported. . A discussion of TMU requirements for 32nm technology and TMU performance data of LFLE and SDPT targets by different overlay approaches will be presented.

A study and simulation of the impact of high-order aberrations to overlay error distribution

NASA Astrophysics Data System (ADS)

Sun, G.; Wang, F.; Zhou, C.

2011-03-01

With reduction of design rules, a number of corresponding new technologies, such as i-HOPC, HOWA and DBO have been proposed and applied to eliminate overlay error. When these technologies are in use, any high-order error distribution needs to be clearly distinguished in order to remove the underlying causes. Lens aberrations are normally thought to mainly impact the Matching Machine Overlay (MMO). However, when using Image-Based overlay (IBO) measurement tools, aberrations become the dominant influence on single machine overlay (SMO) and even on stage repeatability performance. In this paper, several measurements of the error distributions of the lens of SMEE SSB600/10 prototype exposure tool are presented. Models that characterize the primary influence from lens magnification, high order distortion, coma aberration and telecentricity are shown. The contribution to stage repeatability (as measured with IBO tools) from the above errors was predicted with simulator and compared to experiments. Finally, the drift of every lens distortion that impact to SMO over several days was monitored and matched with the result of measurements.

Nigeria: Current Issues

DTIC Science & Technology

2007-04-12

Hausa-Fulani, the southwestern Yoruba , and the southeastern Ibo have traditionally been the most politically active and dominant. Almost half of the...Adamawa State in the January elections, was chosen by the PDP as the running mate of Obasanjo, a Yoruba from southwestern Nigeria. The APP and AD...nominated Chief Olu Falae, a Yoruba , as their joint candidate for president. A former Nigerian security chief and a northerner, Chief Umaru Shinakfi, was

From Fiction to Field Notes: Observing Ibo Culture in "Things Fall Apart."

ERIC Educational Resources Information Center

Schur, Joan Brodsky

1997-01-01

Demonstrates how introducing students to African literature can appeal to their imaginations and encourage them to develop their insights into African culture. Outlines the procedures in a middle school class where the students are transformed into anthropologists as they read Chinua Achebe's, "Things Fall Apart." (MJP)

Malnutrition in the Field. Nigerian Civil War 1968-9

PubMed Central

Hughes, S. P. F.

1969-01-01

A short-term, large-scale medical and feeding programme has been provided for a population of 150,000 in the bush area near Udi in eastern Nigeria (Biafra). By January 1969 8,000 patients were receiving medical treatment each week for varying degrees of protein malnutrition (including kwashiorkor), vitamin deficiency, and dehydration; while 100,000 received weekly rations of a protein-supplemented diet. Close cooperation between the medical team—which consisted of one doctor, four nurses, and two relief workers—and the local Ibo people contributed to the success of the relief programme. PMID:5781491

The effect of individually-induced processes on image-based overlay and diffraction-based overlay

NASA Astrophysics Data System (ADS)

Oh, SeungHwa; Lee, Jeongjin; Lee, Seungyoon; Hwang, Chan; Choi, Gilheyun; Kang, Ho-Kyu; Jung, EunSeung

2014-04-01

In this paper, set of wafers with separated processes was prepared and overlay measurement result was compared in two methods; IBO and DBO. Based on the experimental result, theoretical approach of relationship between overlay mark deformation and overlay variation is presented. Moreover, overlay reading simulation was used in verification and prediction of overlay variation due to deformation of overlay mark caused by induced processes. Through this study, understanding of individual process effects on overlay measurement error is given. Additionally, guideline of selecting proper overlay measurement scheme for specific layer is presented.

Diffraction based overlay re-assessed

NASA Astrophysics Data System (ADS)

Leray, Philippe; Laidler, David; D'havé, Koen; Cheng, Shaunee

2011-03-01

In recent years, numerous authors have reported the advantages of Diffraction Based Overlay (DBO) over Image Based Overlay (IBO), mainly by comparison of metrology figures of merit such as TIS and TMU. Some have even gone as far as to say that DBO is the only viable overlay metrology technique for advanced technology nodes; 22nm and beyond. Typically the only reported drawback of DBO is the size of the required targets. This severely limits its effective use, when all critical layers of a product, including double patterned layers need to be measured, and in-die overlay measurements are required. In this paper we ask whether target size is the only limitation to the adoption of DBO for overlay characterization and control, or are there other metrics, which need to be considered. For example, overlay accuracy with respect to scanner baseline or on-product process overlay control? In this work, we critically re-assess the strengths and weaknesses of DBO for the applications of scanner baseline and on-product process layer overlay control. A comprehensive comparison is made to IBO. For on product process layer control we compare the performance on critical process layers; Gate, Contact and Metal. In particularly we focus on the response of the scanner to the corrections determined by each metrology technique for each process layer, as a measure of the accuracy. Our results show that to characterize an overlay metrology technique that is suitable for use in advanced technology nodes requires much more than just evaluating the conventional metrology metrics of TIS and TMU.

Hybrid overlay metrology with CDSEM in a BEOL patterning scheme

NASA Astrophysics Data System (ADS)

Leray, Philippe; Jehoul, Christiane; Inoue, Osamu; Okagawa, Yutaka

2015-03-01

Overlay metrology accuracy is a major concern for our industry. Advanced logic process require more tighter overlay control for multipatterning schemes. TIS (Tool Induced Shift) and WIS (Wafer Induced Shift) are the main issues for IBO (Image Based Overlay) and DBO (Diffraction Based Overlay). Methods of compensation have been introduced, some are even very efficient to reduce these measured offsets. Another related question is about the overlay target designs. These targets are never fully representative of the design rules, strong efforts have been achieved, but the device cannot be completely duplicated. Ideally, we would like to measure in the device itself to verify the real overlay value. Top down CDSEM can measure critical dimensions of any structure, it is not dependent of specific target design. It can also measure the overlay errors but only in specific cases like LELE (Litho Etch Litho Etch) after final patterning. In this paper, we will revisit the capability of the CDSEM at final patterning by measuring overlay in dedicated targets as well as inside a logic and an SRAM design. In the dedicated overlay targets, we study the measurement differences between design rules gratings and relaxed pitch gratings. These relaxed pitch which are usually used in IBO or DBO targets. Beyond this "simple" LELE case, we will explore the capability of the CDSEM to measure overlay even if not at final patterning, at litho level. We will assess the hybridization of DBO and CDSEM for reference to optical tools after final patterning. We will show that these reference data can be used to validate the DBO overlay results (correctables and residual fingerprints).

Faster diffraction-based overlay measurements with smaller targets using 3D gratings

NASA Astrophysics Data System (ADS)

Li, Jie; Kritsun, Oleg; Liu, Yongdong; Dasari, Prasad; Volkman, Catherine; Hu, Jiangtao

2012-03-01

Diffraction-based overlay (DBO) technologies have been developed to address the overlay metrology challenges for 22nm technology node and beyond. Most DBO technologies require specially designed targets that consist of multiple measurement pads, which consume too much space and increase measurement time. The traditional empirical approach (eDBO) using normal incidence spectroscopic reflectometry (NISR) relies on linear response of the reflectance with respect to overlay displacement within a small range. It offers convenience of quick recipe setup since there is no need to establish a model. However it requires three or four pads per direction (x or y) which adds burden to throughput and target size. Recent advances in modeling capability and computation power enabled mDBO, which allows overlay measurement with reduced number of pads, thus reducing measurement time and DBO target space. In this paper we evaluate the performance of single pad mDBO measurements using two 3D targets that have different grating shapes: squares in boxes and L-shapes in boxes. Good overlay sensitivities are observed for both targets. The correlation to programmed shifts and image-based overlay (IBO) is excellent. Despite the difference in shapes, the mDBO results are comparable for square and L-shape targets. The impact of process variations on overlay measurements is studied using a focus and exposure matrix (FEM) wafer. Although the FEM wafer has larger process variations, the correlation of mDBO results with IBO measurements is as good as the normal process wafer. We demonstrate the feasibility of single pad DBO measurements with faster throughput and smaller target size, which is particularly important in high volume manufacturing environment.

Overlay metrology for double patterning processes

NASA Astrophysics Data System (ADS)

Leray, Philippe; Cheng, Shaunee; Laidler, David; Kandel, Daniel; Adel, Mike; Dinu, Berta; Polli, Marco; Vasconi, Mauro; Salski, Bartlomiej

2009-03-01

The double patterning (DPT) process is foreseen by the industry to be the main solution for the 32 nm technology node and even beyond. Meanwhile process compatibility has to be maintained and the performance of overlay metrology has to improve. To achieve this for Image Based Overlay (IBO), usually the optics of overlay tools are improved. It was also demonstrated that these requirements are achievable with a Diffraction Based Overlay (DBO) technique named SCOLTM [1]. In addition, we believe that overlay measurements with respect to a reference grid are required to achieve the required overlay control [2]. This induces at least a three-fold increase in the number of measurements (2 for double patterned layers to the reference grid and 1 between the double patterned layers). The requirements of process compatibility, enhanced performance and large number of measurements make the choice of overlay metrology for DPT very challenging. In this work we use different flavors of the standard overlay metrology technique (IBO) as well as the new technique (SCOL) to address these three requirements. The compatibility of the corresponding overlay targets with double patterning processes (Litho-Etch-Litho-Etch (LELE); Litho-Freeze-Litho-Etch (LFLE), Spacer defined) is tested. The process impact on different target types is discussed (CD bias LELE, Contrast for LFLE). We compare the standard imaging overlay metrology with non-standard imaging techniques dedicated to double patterning processes (multilayer imaging targets allowing one overlay target instead of three, very small imaging targets). In addition to standard designs already discussed [1], we investigate SCOL target designs specific to double patterning processes. The feedback to the scanner is determined using the different techniques. The final overlay results obtained are compared accordingly. We conclude with the pros and cons of each technique and suggest the optimal metrology strategy for overlay control in double

Historical Change of Equilibrium Water Temperature in Japan

NASA Astrophysics Data System (ADS)

Miyamoto, H.

2015-12-01

Changes in freshwater ecosystems due to a climate change have been great concern for sustainable river basin management both for water resources utilization and ecological conservation. However, their impact seems to be difficult to evaluate because of wide variety of basin characteristics along a river network both in nature and social environment. This presentation uses equilibrium water temperature as a simple criterion index for evaluating the long-term changes of stream thermal environment due to the historical climate change in Japan. It examines, at first, the relationship between the equilibrium water temperature and the stream temperature observed for 7 years at a lower reach in the Ibo River, Japan. It analyzes, then, the seasonal and regional trends of the equilibrium water temperature change for the last 50 years at 133 meteorological station sites throughout Japan, discussing their rising or falling characteristics. The correlation analysis at the local reach of the Ibo River shows that the equilibrium water temperature has similar trend of change as the stream temperature. However, its value tends to be higher than the stream temperature in summer, while lower in winter. The onset of the higher equilibrium water temperature fluctuates annually from mid February to early April. This onset fluctuation at each spring could be influenced by the different amount of snow at the antecedent winter. The rising or falling trends of the equilibrium water temperature are analyzed both annually and seasonally through the regression analysis of the 133 sites in Japan. Consequently, the trends of the temperature change could be categorized by 12 patterns. As for the seasonal analysis, the results shows that there are many sites indicating the falling trend in spring and summer, and rising trends in autumn and winter. In particular, winter has the strong rising tendency throughout Japan. As for the regional analysis, the result illustrates the precise rationality; e

Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place, FY 85. Part 14 (Middletown Limousine Sus - North American Carbide Tooling).

DTIC Science & Technology

1985-01-01

Suite � .4 u ~~c s~~e IBo OFFICE SYP.40O 9 PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER O(AN.’-i U0 j if aPPIicabJC) h,~ .. . (City State and ZIP...4 -4 4 4 A 9 o4 m1W "i 0 M () A W I0100 (n .n00 . . . . . . -.j 0 4 44 44 03 :O 󈧇 0-. (N UN001 WL 4 0 -44 4cm ito o-NN1100II0erP-s-40 -4 WC.1- 1󈧄...00 ( 0 I . ) ) 0-6(CO001 2Z00 000 00 c oG c ) 0 00 *00 Ga* c c 00000 to 0 so 0.aa.s4ha 90Omcc01caCO m((0 -101 - 009L - 009- 9 - LA- I 00 -0 00 444 00 44

Academic Civic Mindedness and Model Citizenship in the International Baccalaureate Diploma Programme. Working Paper WR-1044-IBO

ERIC Educational Resources Information Center

Saavedra, Anna Rosefsky

2014-01-01

Originally founded as a private means for diplomats' children to earn an internationally recognized high school diploma, today the International Baccalaureate (IB) Diploma Programme (DP) serves students from a variety of backgrounds in 144 countries. The IB mission and Learner Profile--consisting of ten attributes to foster in students--suggest…

The intestinal microbiome and the leaky gut as therapeutic targets in alcoholic liver disease

PubMed Central

Hartmann, Phillipp; Chen, Wei-Chung; Schnabl, Bernd

2012-01-01

Alcoholic liver disease (ALD) encompasses hepatic steatosis, which may progress to alcoholic hepatitis, fibrosis, and cirrhosis. It remains a leading cause of morbidity and mortality in the US and worldwide. The severity of liver disease correlates with plasma levels of bacterial products in patients, and experimental ALD depends on the level of gut derived bacterial products in rodents. Since intestinal decontamination and deficiency of bacterial product receptors or their downstream signaling molecules protect from alcohol-induced liver disease, bacterial translocation (BT), qualitative, and quantitative changes of the enteric microbiome are considered as being of fundamental importance in the pathogenesis of ALD. Recent enhancements in diagnostic technologies provide a better insight into these shifts. This review highlights vital events in ALD such as BT, the importance of Toll-like receptor (TLR) signaling, intestinal bacterial overgrowth (IBO), and changes in the intestinal microbiome. Furthermore, a treatment trial section of patients reviews possible future options of therapy for ALD modifying the enteric microbiome. PMID:23087650

Accuracy optimization with wavelength tunability in overlay imaging technology

NASA Astrophysics Data System (ADS)

Lee, Honggoo; Kang, Yoonshik; Han, Sangjoon; Shim, Kyuchan; Hong, Minhyung; Kim, Seungyoung; Lee, Jieun; Lee, Dongyoung; Oh, Eungryong; Choi, Ahlin; Kim, Youngsik; Marciano, Tal; Klein, Dana; Hajaj, Eitan M.; Aharon, Sharon; Ben-Dov, Guy; Lilach, Saltoun; Serero, Dan; Golotsvan, Anna

2018-03-01

As semiconductor manufacturing technology progresses and the dimensions of integrated circuit elements shrink, overlay budget is accordingly being reduced. Overlay budget closely approaches the scale of measurement inaccuracies due to both optical imperfections of the measurement system and the interaction of light with geometrical asymmetries of the measured targets. Measurement inaccuracies can no longer be ignored due to their significant effect on the resulting device yield. In this paper we investigate a new approach for imaging based overlay (IBO) measurements by optimizing accuracy rather than contrast precision, including its effect over the total target performance, using wavelength tunable overlay imaging metrology. We present new accuracy metrics based on theoretical development and present their quality in identifying the measurement accuracy when compared to CD-SEM overlay measurements. The paper presents the theoretical considerations and simulation work, as well as measurement data, for which tunability combined with the new accuracy metrics is shown to improve accuracy performance.

Diffraction-based overlay measurement on dedicated mark using rigorous modeling method

NASA Astrophysics Data System (ADS)

Lu, Hailiang; Wang, Fan; Zhang, Qingyun; Chen, Yonghui; Zhou, Chang

2012-03-01

Diffraction Based Overlay (DBO) is widely evaluated by numerous authors, results show DBO can provide better performance than Imaging Based Overlay (IBO). However, DBO has its own problems. As well known, Modeling based DBO (mDBO) faces challenges of low measurement sensitivity and crosstalk between various structure parameters, which may result in poor accuracy and precision. Meanwhile, main obstacle encountered by empirical DBO (eDBO) is that a few pads must be employed to gain sufficient information on overlay-induced diffraction signature variations, which consumes more wafer space and costs more measuring time. Also, eDBO may suffer from mark profile asymmetry caused by processes. In this paper, we propose an alternative DBO technology that employs a dedicated overlay mark and takes a rigorous modeling approach. This technology needs only two or three pads for each direction, which is economic and time saving. While overlay measurement error induced by mark profile asymmetry being reduced, this technology is expected to be as accurate and precise as scatterometry technologies.

Genetic Characterization of the Tick-Borne Orbiviruses

PubMed Central

Belaganahalli, Manjunatha N.; Maan, Sushila; Maan, Narender S.; Brownlie, Joe; Tesh, Robert; Attoui, Houssam; Mertens, Peter P. C.

2015-01-01

The International Committee for Taxonomy of Viruses (ICTV) recognizes four species of tick-borne orbiviruses (TBOs): Chenuda virus, Chobar Gorge virus, Wad Medani virus and Great Island virus (genus Orbivirus, family Reoviridae). Nucleotide (nt) and amino acid (aa) sequence comparisons provide a basis for orbivirus detection and classification, however full genome sequence data were only available for the Great Island virus species. We report representative genome-sequences for the three other TBO species (virus isolates: Chenuda virus (CNUV); Chobar Gorge virus (CGV) and Wad Medani virus (WMV)). Phylogenetic comparisons show that TBOs cluster separately from insect-borne orbiviruses (IBOs). CNUV, CGV, WMV and GIV share low level aa/nt identities with other orbiviruses, in ‘conserved’ Pol, T2 and T13 proteins/genes, identifying them as four distinct virus-species. The TBO genome segment encoding cell attachment, outer capsid protein 1 (OC1), is approximately half the size of the equivalent segment from insect-borne orbiviruses, helping to explain why tick-borne orbiviruses have a ~1 kb smaller genome. PMID:25928203

Genetic characterization of the tick-borne orbiviruses.

PubMed

Belaganahalli, Manjunatha N; Maan, Sushila; Maan, Narender S; Brownlie, Joe; Tesh, Robert; Attoui, Houssam; Mertens, Peter P C

2015-04-28

The International Committee for Taxonomy of Viruses (ICTV) recognizes four species of tick-borne orbiviruses (TBOs): Chenuda virus, Chobar Gorge virus, Wad Medani virus and Great Island virus (genus Orbivirus, family Reoviridae). Nucleotide (nt) and amino acid (aa) sequence comparisons provide a basis for orbivirus detection and classification, however full genome sequence data were only available for the Great Island virus species. We report representative genome-sequences for the three other TBO species (virus isolates: Chenuda virus (CNUV); Chobar Gorge virus (CGV) and Wad Medani virus (WMV)). Phylogenetic comparisons show that TBOs cluster separately from insect-borne orbiviruses (IBOs). CNUV, CGV, WMV and GIV share low level aa/nt identities with other orbiviruses, in 'conserved' Pol, T2 and T13 proteins/genes, identifying them as four distinct virus-species. The TBO genome segment encoding cell attachment, outer capsid protein 1 (OC1), is approximately half the size of the equivalent segment from insect-borne orbiviruses, helping to explain why tick-borne orbiviruses have a ~1 kb smaller genome.

Diffraction based overlay and image based overlay on production flow for advanced technology node

NASA Astrophysics Data System (ADS)

Blancquaert, Yoann; Dezauzier, Christophe

2013-04-01

One of the main challenges for lithography step is the overlay control. For the advanced technology node like 28nm and 14nm, the overlay budget becomes very tight. Two overlay techniques compete in our advanced semiconductor manufacturing: the Diffraction based Overlay (DBO) with the YieldStar S200 (ASML) and the Image Based Overlay (IBO) with ARCHER (KLA). In this paper we will compare these two methods through 3 critical production layers: Poly Gate, Contact and first metal layer. We will show the overlay results of the 2 techniques, explore the accuracy and compare the total measurement uncertainty (TMU) for the standard overlay targets of both techniques. We will see also the response and impact for the Image Based Overlay and Diffraction Based Overlay techniques through a process change like an additional Hardmask TEOS layer on the front-end stack. The importance of the target design is approached; we will propose more adapted design for image based targets. Finally we will present embedded targets in the 14 FDSOI with first results.

Climatology, Natural Cycles, and Modes of Interannual Variability of the Great Plains Low-Level Jet as Assimilated by the GEOS-1 Data Analysis System

NASA Technical Reports Server (NTRS)

Helfand, H. M.; Schubert, S. D.; Atlas, Robert (Technical Monitor)

2002-01-01

Despite the fact that the low-level jet of the southern Great Plains (the GPLLJ) of the U.S. is primarily a nocturnal phenomenon that virtually vanishes during the daylight hours, it is one of the most persistent and stable features of the low-level continental flow during the warm-season months, May through August. We have first used significant-level data to validate the skill of the GEOS-1 Data Assimilation System (DAS) in realistically detecting this jet and inferring its structure and evolution. We have then carried out a 15-year reanalysis with the GEOS-1 DAS to determine and validate its climatology and mean diurnal cycle and to study its interannual variability. Interannual variability of the GPLLJ is much smaller than mean diurnal and random intraseasonal variability and comparable in magnitude, but not location, to mean seasonal variability. There are three maxima of interannual low-level meridional flow variability of the GPLLJ over the upper Great Plains, southeastern Texas, and the western Gulf of Mexico. Cross-sectional profiles of mean southerly wind through the Texas maximum remain relatively stable and recognizable from year to year with only its eastward flank showing significant variability. This variability, however, exhibits a distinct, biennial oscillation during the first six years of the reanalysis period and only then. Each of the three variability maxima corresponds to a spatially coherent, jet-like pattern of low-level flow interannual variability. There are three prominent modes of interannual. variability. These include the intermittent biennial oscillation (IBO), local to the Texas maximum. Its signal is evident in surface pressure, surface temperature, ground wetness and upper air flow, as well. A larger-scale continental convergence pattern (CCP) of covariance, exhibiting strong anti-correlation between the flow near the Texas and the upper Great Plains variability maxima, is revealed only when the IBO is removed from the interannual

Overlay accuracy with respect to device scaling

NASA Astrophysics Data System (ADS)

Leray, Philippe; Laidler, David; Cheng, Shaunee

2012-03-01

Overlay metrology performance is usually reported as repeatability, matching between tools or optics aberrations distorting the measurement (Tool induced shift or TIS). Over the last few years, improvement of these metrics by the tool suppliers has been impressive. But, what about accuracy? Using different target types, we have already reported small differences in the mean value as well as fingerprint [1]. These differences make the correctables questionable. Which target is correct and therefore which translation, scaling etc. values should be fed back to the scanner? In this paper we investigate the sources of these differences, using several approaches. First, we measure the response of different targets to offsets programmed in a test vehicle. Second, we check the response of the same overlay targets to overlay errors programmed into the scanner. We compare overlay target designs; what is the contribution of the size of the features that make up the target? We use different overlay measurement techniques; is DBO (Diffraction Based Overlay) more accurate than IBO (Image Based Overlay)? We measure overlay on several stacks; what is the stack contribution to inaccuracy? In conclusion, we offer an explanation for the observed differences and propose a solution to reduce them.

Achieving optimum diffraction based overlay performance

NASA Astrophysics Data System (ADS)

Leray, Philippe; Laidler, David; Cheng, Shaunee; Coogans, Martyn; Fuchs, Andreas; Ponomarenko, Mariya; van der Schaar, Maurits; Vanoppen, Peter

2010-03-01

Diffraction Based Overlay (DBO) metrology has been shown to have significantly reduced Total Measurement Uncertainty (TMU) compared to Image Based Overlay (IBO), primarily due to having no measurable Tool Induced Shift (TIS). However, the advantages of having no measurable TIS can be outweighed by increased susceptibility to WIS (Wafer Induced Shift) caused by target damage, process non-uniformities and variations. The path to optimum DBO performance lies in having well characterized metrology targets, which are insensitive to process non-uniformities and variations, in combination with optimized recipes which take advantage of advanced DBO designs. In this work we examine the impact of different degrees of process non-uniformity and target damage on DBO measurement gratings and study their impact on overlay measurement accuracy and precision. Multiple wavelength and dual polarization scatterometry are used to characterize the DBO design performance over the range of process variation. In conclusion, we describe the robustness of DBO metrology to target damage and show how to exploit the measurement capability of a multiple wavelength, dual polarization scatterometry tool to ensure the required measurement accuracy for current and future technology nodes.

Chemical composition, functional and sensory characteristics of wheat-taro composite flours and biscuits.

PubMed

Himeda, Makhlouf; Njintang Yanou, Nicolas; Fombang, Edith; Facho, Balaam; Kitissou, Pierre; Mbofung, Carl M F; Scher, Joel

2014-09-01

The physicochemical, alveographic and sensory characteristics of precooked taro-wheat composite flours and their biscuits were investigated. A 2x7 factorial design consisting of two varieties of taro flour (Red Ibo Ngaoundere, RIN, and egg-like varieties) and 7 levels of wheat substitutions (0, 5, 10, 15, 20, 25 and 30 %) was used for this purpose. It was observed that water absorption capacity (range 95-152 g/100 g), water solubility index (range 18.8-29.5 g/100 g) and swelling capacity (range 125.4-204.6 mL/100 g) of composite flours significantly (p < 0.05) increased with increase in taro level. Conversely the dough elasticity index (range 59.8-0 %), extensibility (78-22 mm) and strength (range 281-139 × 10(-4) joules) significantly (p < 0.05) diminished with increase in wheat substitution. Up to 10 % substitution with RIN taro flour and 15 % with egg-like taro flour, the composite taro-wheat dough exhibited elasticity indices acceptable for the production of baking products, whereas at all levels of taro substitution, the composite biscuits samples were either acceptable as or better (5-10 % substitution with RIN flour) than 100 % wheat biscuit.

Advanced overlay analysis through design based metrology

NASA Astrophysics Data System (ADS)

Ji, Sunkeun; Yoo, Gyun; Jo, Gyoyeon; Kang, Hyunwoo; Park, Minwoo; Kim, Jungchan; Park, Chanha; Yang, Hyunjo; Yim, Donggyu; Maruyama, Kotaro; Park, Byungjun; Yamamoto, Masahiro

2015-03-01

As design rule shrink, overlay has been critical factor for semiconductor manufacturing. However, the overlay error which is determined by a conventional measurement with an overlay mark based on IBO and DBO often does not represent the physical placement error in the cell area. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion caused by etching or CMP also can be a source of the mismatch. In 2014, we have demonstrated that method of overlay measurement in the cell area by using DBM (Design Based Metrology) tool has more accurate overlay value than conventional method by using an overlay mark. We have verified the reproducibility by measuring repeatable patterns in the cell area, and also demonstrated the reliability by comparing with CD-SEM data. We have focused overlay mismatching between overlay mark and cell area until now, further more we have concerned with the cell area having different pattern density and etch loading. There appears a phenomenon which has different overlay values on the cells with diverse patterning environment. In this paper, the overlay error was investigated from cell edge to center. For this experiment, we have verified several critical layers in DRAM by using improved(Better resolution and speed) DBM tool, NGR3520.

Hybrid overlay metrology for high order correction by using CDSEM

NASA Astrophysics Data System (ADS)

Leray, Philippe; Halder, Sandip; Lorusso, Gian; Baudemprez, Bart; Inoue, Osamu; Okagawa, Yutaka

2016-03-01

Overlay control has become one of the most critical issues for semiconductor manufacturing. Advanced lithographic scanners use high-order corrections or correction per exposure to reduce the residual overlay. It is not enough in traditional feedback of overlay measurement by using ADI wafer because overlay error depends on other process (etching process and film stress, etc.). It needs high accuracy overlay measurement by using AEI wafer. WIS (Wafer Induced Shift) is the main issue for optical overlay, IBO (Image Based Overlay) and DBO (Diffraction Based Overlay). We design dedicated SEM overlay targets for dual damascene process of N10 by i-ArF multi-patterning. The pattern is same as device-pattern locally. Optical overlay tools select segmented pattern to reduce the WIS. However segmentation has limit, especially the via-pattern, for keeping the sensitivity and accuracy. We evaluate difference between the viapattern and relaxed pitch gratings which are similar to optical overlay target at AEI. CDSEM can estimate asymmetry property of target from image of pattern edge. CDSEM can estimate asymmetry property of target from image of pattern edge. We will compare full map of SEM overlay to full map of optical overlay for high order correction ( correctables and residual fingerprints).

STEM Beyond The Classroom: Creating Authentic Outreach Programs That Build Bridges Between The Classroom And Real World Challenges

NASA Astrophysics Data System (ADS)

Ibarra, D. L.; Forder, S. E.; Pritchard, M.

2014-12-01

The ISF Academy was founded by Charles Kao, a Nobel Prize laureate. In 2011, the Shuyuan programs were established at The ISF Academy to operate both as a "school within a school" and as a "school outside the classroom." The Shuyuan programs work together with the IBO Science and Technology subject areas to develop comprehensive and challenging opportunities that address the 14 Grand Engineering Challenges. The goal is to establish co-curricular programs that go beyond the taught curriculum and support STEM curricula. Several programs outside of the classroom include an onsite robotics researcher, underwater and land based robotics programs, field trips, whole school food waste composting and the implementation of an energy tracking system. Relationships with several local universities allow students to work closely with professors in research settings and, annually, a leading researcher gives a keynote speech to our students. Other signature Shuyuan programs have developed international strategic relationships with the NRI at Cambridge University, where students spend several weeks studying science and civilization in China using primary source materials. Additionally, Shuyuan has supported extension opportunities for classroom teachers with institutional partnerships that include the British Council, governmental organizations, local universities, corporations, and NGOs. In conclusion, the overall goal of the Shuyuan Programs is to provide experiential learning opportunities that challenge conventional curriculum design in a manner that is supportive and innovative!

The Biotechnology of Ugba, a Nigerian Traditional Fermented Food Condiment

PubMed Central

Olasupo, Nurudeen A.; Okorie, Chimezie P.; Oguntoyinbo, Folarin A.

2016-01-01

Legumes and oil bean seeds used for the production of condiments in Africa are inedible in their natural state; they contain some anti-nutritional factors especially undigestible oligosaccharides and phytate. Fermentation impact desirable changes by reducing anti-nutritional factors and increasing digestibility. Ugba is an alkaline fermented African oil bean cotyledon (Pentaclethra macrophylla) produced by the Ibos and other ethnic groups in southern Nigeria. Seen as a family business in many homes, its preparation is in accordance with handed-down tradition from previous generations and serves as a cheap source of plant protein. Its consumption as a native salad is made possible by fermentation of the cotyledon for 2–5 days, but could also serve as a soup flavoring agent when fermentation last for 6–10 days. The fermentation process involved is usually natural with an attendant issue of product safety, quality and inconsistency. The production of this condiment is on a small scale and the equipment used are very rudimentary, devoid of good manufacturing procedures that call to question the issue of microbial safety. This paper therefore reviews the production process and the spectrum of microbial composition involved during fermentation. In addition, potential spoilage agents, nutritional and biochemical changes during production are examined. Furthermore, information that can support development of starter cultures for controlled fermentation process in order to guarantee microbiological safety, quality and improved shelf life are also discussed. PMID:27540371

An assessment of the mechanical stability of wells offshore Nigeria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lowrey, J.P.; Ottesen, S.

In 1991 lost time due to stuck pipe related drilling problems accounted for approximately 18% of total drilling time in Mobil Producing Nigeria Ultd.`s (MPN) offshore operations. The primary cause of stuck pipe was identified as mechanical wellbore instability. This paper presents an assessment of the mechanical stability of MPN`s wells offshore Nigeria. The objectives of the study were to: (1) determine the magnitude of the in-situ principal stresses and material properties of the troublesome Intra-Biafra and Qua Iboe shale sequences; (2) quantify the drilling fluid densities required to drill mechanically stable wells through these formations; (3) review and recommendmore » well planning and operational parameters which aid in minimizing wellbore stability-related drilling problems. The well-bore stability assessment was carried out with the aid of a 3-dimensional wellbore stability model using field derived data from the study area to corroborate the results. The collection and analysis of drilling data (borehole geometry and density logs, pore pressure, leak-off tests, local geology and other relevant well records) to determine the magnitude of the in-situ principal stresses, together with compressive strength tests on formation cores are discussed. Minimum safe drilling fluid densities to promote wellbore stability as a function of well geometry and depth are presented for the most troublesome shales drilled in the study area. Implementation of the results reduced wellbore stability related problems and associated trouble time to less than 5% in 1992.« less

Advanced diffraction-based overlay for double patterning

NASA Astrophysics Data System (ADS)

Li, Jie; Liu, Yongdong; Dasari, Prasad; Hu, Jiangtao; Smith, Nigel; Kritsun, Oleg; Volkman, Catherine

2010-03-01

Diffraction based overlay (DBO) technologies have been developed to address the tighter overlay control challenges as the dimensions of integrated circuit continue to shrink. Several studies published recently have demonstrated that the performance of DBO technologies has the potential to meet the overlay metrology budget for 22nm technology node. However, several hurdles must be cleared before DBO can be used in production. One of the major hurdles is that most DBO technologies require specially designed targets that consist of multiple measurement pads, which consume too much space and increase measurement time. A more advanced spectroscopic ellipsometry (SE) technology-Mueller Matrix SE (MM-SE) is developed to address the challenge. We use a double patterning sample to demonstrate the potential of MM-SE as a DBO candidate. Sample matrix (the matrix that describes the effects of the sample on the incident optical beam) obtained from MM-SE contains up to 16 elements. We show that the Mueller elements from the off-diagonal 2x2 blocks respond to overlay linearly and are zero when overlay errors are absent. This superior property enables empirical DBO (eDBO) using two pads per direction. Furthermore, the rich information in Mueller matrix and its direct response to overlay make it feasible to extract overlay errors from only one pad per direction using modeling approach (mDBO). We here present the Mueller overlay results using both eDBO and mDBO and compare the results with image-based overlay (IBO) and CD-SEM results. We also report the tool induced shifts (TIS) and dynamic repeatability.

Enhacement of intrafield overlay using a design based metrology system

NASA Astrophysics Data System (ADS)

Jo, Gyoyeon; Ji, Sunkeun; Kim, Shinyoung; Kang, Hyunwoo; Park, Minwoo; Kim, Sangwoo; Kim, Jungchan; Park, Chanha; Yang, Hyunjo; Maruyama, Kotaro; Park, Byungjun

2016-03-01

As the scales of the semiconductor devices continue to shrink, accurate measurement and control of the overlay have been emphasized for securing more overlay margin. Conventional overlay analysis methods are based on the optical measurement of the overlay mark. However, the overlay data obtained from these optical methods cannot represent the exact misregistration between two layers at the circuit level. The overlay mismatch may arise from the size or pitch difference between the overlay mark and the real pattern. Pattern distortion, caused by CMP or etching, could be a source of the overlay mismatch as well. Another issue is the overlay variation in the real circuit pattern which varies depending on its location. The optical overlay measurement methods, such as IBO and DBO that use overlay mark on the scribeline, are not capable of defining the exact overlay values of the real circuit. Therefore, the overlay values of the real circuit need to be extracted to integrate the semiconductor device properly. The circuit level overlay measurement using CDSEM is time-consuming in extracting enough data to indicate overall trend of the chip. However DBM tool is able to derive sufficient data to display overlay tendency of the real circuit region with high repeatability. An E-beam based DBM(Design Based Metrology) tool can be an alternative overlay measurement method. In this paper, we are going to certify that the overlay values extracted from optical measurement cannot represent the circuit level overlay values. We will also demonstrate the possibility to correct misregistration between two layers using the overlay data obtained from the DBM system.

64nm pitch metal1 double patterning metrology: CD and OVL control by SEMCD, image based overlay and diffraction based overlay

NASA Astrophysics Data System (ADS)

Ducoté, Julien; Dettoni, Florent; Bouyssou, Régis; Le-Gratiet, Bertrand; Carau, Damien; Dezauzier, Christophe

2015-03-01

Patterning process control of advanced nodes has required major changes over the last few years. Process control needs of critical patterning levels since 28nm technology node is extremely aggressive showing that metrology accuracy/sensitivity must be finely tuned. The introduction of pitch splitting (Litho-Etch-Litho-Etch) at 14FDSOInm node requires the development of specific metrologies to adopt advanced process control (for CD, overlay and focus corrections). The pitch splitting process leads to final line CD uniformities that are a combination of the CD uniformities of the two exposures, while the space CD uniformities are depending on both CD and OVL variability. In this paper, investigations of CD and OVL process control of 64nm minimum pitch at Metal1 level of 14FDSOI technology, within the double patterning process flow (Litho, hard mask etch, line etch) are presented. Various measurements with SEMCD tools (Hitachi), and overlay tools (KT for Image Based Overlay - IBO, and ASML for Diffraction Based Overlay - DBO) are compared. Metrology targets are embedded within a block instanced several times within the field to perform intra-field process variations characterizations. Specific SEMCD targets were designed for independent measurement of both line CD (A and B) and space CD (A to B and B to A) for each exposure within a single measurement during the DP flow. Based on those measurements correlation between overlay determined with SEMCD and with standard overlay tools can be evaluated. Such correlation at different steps through the DP flow is investigated regarding the metrology type. Process correction models are evaluated with respect to the measurement type and the intra-field sampling.

ABO and rhesus antigens in a cosmopolitan Nigeria population.

PubMed

Nwauche, C A; Ejele, O A

2004-01-01

Port Harcourt is a cosmopolitan city consisting of several ethnic groupings such as Ikwerre, Ijaw, Igbo, Ogonis, Efik-Ibibio, Edo, Yoruba, Hausa and foreign nationals. ABO and Rhesus D antigens were screened in this cross-sectional study with the aim of generating data that would assist in the running of an efficient blood transfusion service for a cosmopolitan city as Port Harcourt. Blood donors were sampled and screened for ABO and Rhesus D antigens at three Health facilities within Port Harcourt: University of Port Harcourt Teaching Hospital, Braithwaite Memorial Hospital and Orogbum Health centre. A total of 936 blood donors were tested in this study. The results of the ABO screening shows that blood group O was the highest with 527 (56.30%) followed by blood group A, B and lastly AB with 212 (22.65%), 178 (19.02%) and 18(2.10%) respectively. The highest contribution to blood group O was from the Ibos with 220 (23.50%) while the Ijaws gave the highest contribution of Rhesus "D" antigen with 370 (39.53%), closely followed by the Igbos with 334 (0.43%). Rhesus negativity values in this study was 7.26% of which the highest contributors were also the Ijaws with 33 (3.53%) and Igbos with 27(2.89%). The increased demand for safe blood calls for an efficient Blood, Transfusion Service at the local, state and national levels. It is hoped that the data generated in this study would assist in the planning and establishment of a functional Blood service that would not only meet the ever increasing demand for blood products, but also play a vital role in the control of HIV/AIDS and . Hepatitis B global scourge.

Simultaneous overlay and CD measurement for double patterning: scatterometry and RCWA approach

NASA Astrophysics Data System (ADS)

Li, Jie; Liu, Zhuan; Rabello, Silvio; Dasari, Prasad; Kritsun, Oleg; Volkman, Catherine; Park, Jungchul; Singh, Lovejeet

2009-03-01

As optical lithography advances to 32 nm technology node and beyond, double patterning technology (DPT) has emerged as an attractive solution to circumvent the fundamental optical limitations. DPT poses unique demands on critical dimension (CD) uniformity and overlay control, making the tolerance decrease much faster than the rate at which critical dimension shrinks. This, in turn, makes metrology even more challenging. In the past, multi-pad diffractionbased overlay (DBO) using empirical approach has been shown to be an effective approach to measure overlay error associated with double patterning [1]. In this method, registration errors for double patterning were extracted from specially designed diffraction targets (three or four pads for each direction); CD variation is assumed negligible within each group of adjacent pads and not addressed in the measurement. In another paper, encouraging results were reported with a first attempt at simultaneously extracting overlay and CD parameters using scatterometry [2]. In this work, we apply scatterometry with a rigorous coupled wave analysis (RCWA) approach to characterize two double-patterning processes: litho-etch-litho-etch (LELE) and litho-freeze-litho-etch (LFLE). The advantage of performing rigorous modeling is to reduce the number of pads within each measurement target, thus reducing space requirement and improving throughput, and simultaneously extract CD and overlay information. This method measures overlay errors and CDs by fitting the optical signals with spectra calculated from a model of the targets. Good correlation is obtained between the results from this method and that of several reference techniques, including empirical multi-pad DBO, CD-SEM, and IBO. We also perform total measurement uncertainty (TMU) analysis to evaluate the overall performance. We demonstrate that scatterometry provides a promising solution to meet the challenging overlay metrology requirement in DPT.

Sustainability Infused Curriculum

NASA Astrophysics Data System (ADS)

Ibarra, D. L.

2015-12-01

The Independent Schools Foundation Academy (ISF) in Hong Kong established a sustainability policy in 2015, which explicitly states, "an experimentally integrated, environmentally and ethically sustainable system of science education and conservation practices based on the 2012 Jeju Declaration of the World Conservation Congress will be implemented through the school". ISF Academy is a private Chinese bilingual school in Hong Kong serving over 1500 students K-12, following the framework and curriculum of the International Baccalaureate Organization (IBO). The strategy behind the implementation of this policy includes: development of a scientific sustainable curriculum that is age appropriate; establish a culture of sustainability within the ISF community and beyond to the wider HK community; install sustainable infrastructure that allows students to learn; and learn first hand sustainable living practices. It is well understood that solutions to the environmental challenges facing Hong Kong and our planet will require multiple disciplines. The current sustainability programs at ISF include: a) a whole school aerobic food waste composting system and organic farming, b) energy consumption monitoring of existing buildings, c) upcoming installation of an air pollution monitoring equipment that will correlate with the AQHI data collected by the Hong Kong government, d) a Renewable Energy Education Center (REEC) that will teach students about RE and also produce solar energy for classroom consumption, and e) student lead environmental group that manages the paper and used cooking oil recycling on campus. The Shuyuan Science and Sustainability faculty work closely with classroom teachers to ensure that the above mentioned projects are incorporated into the curriculum throughout the school. Interdisciplinary units (IDU) of study are being developed that encourage faculty and students to work across subject areas. Projects include Personal Projects, Extended Essays

Evaluation of Experiential Outdoor Research Locations in Asia for a K-12 school in Hong Kong

NASA Astrophysics Data System (ADS)

Ibarra, D. L.; Joyce, S.

2016-12-01

curriculum of the IBO for the secondary school. Delivering a curriculum of this complexity will require participation and input from faculty across all disciplines.

SEM based overlay measurement between resist and buried patterns

NASA Astrophysics Data System (ADS)

Inoue, Osamu; Okagawa, Yutaka; Hasumi, Kazuhisa; Shao, Chuanyu; Leray, Philippe; Lorusso, Gian; Baudemprez, Bart

2016-03-01

With the continuous shrink in pattern size and increased density, overlay control has become one of the most critical issues in semiconductor manufacturing. Recently, SEM based overlay of AEI (After Etch Inspection) wafer has been used for reference and optimization of optical overlay (both Image Based Overlay (IBO) and Diffraction Based Overlay (DBO)). Overlay measurement at AEI stage contributes monitor and forecast the yield after formation by etch and calibrate optical measurement tools. however those overlay value seems difficult directly for feedback to a scanner. Therefore, there is a clear need to have SEM based overlay measurements of ADI (After Develop Inspection) wafers in order to serve as reference for optical overlay and make necessary corrections before wafers go to etch. Furthermore, to make the corrections as accurate as possible, actual device like feature dimensions need to be measured post ADI. This device size measurement is very unique feature of CDSEM , which can be measured with smaller area. This is currently possible only with the CD-SEM. This device size measurement is very unique feature of CD-SEM , which can be measured with smaller area. In this study, we assess SEM based overlay measurement of ADI and AEI wafer by using a sample from an N10 process flow. First, we demonstrate SEM based overlay performance at AEI by using dual damascene process for Via 0 (V0) and metal 1 (M1) layer. We also discuss the overlay measurements between litho-etch-litho stages of a triple patterned M1 layer and double pattern V0. Second, to illustrate the complexities in image acquisition and measurement we will measure overlay between M1B resist and buried M1A-Hard mask trench. Finally, we will show how high accelerating voltage can detect buried pattern information by BSE (Back Scattering Electron). In this paper we discuss the merits of this method versus standard optical metrology based corrections.

Environmental legal implications of oil and gas exploration in the Niger Delta of Nigeria

NASA Astrophysics Data System (ADS)

Orubebe, Bibobra Bello

Nigeria is an African country endowed with a wealth of oil and gas resources, and they are mainly found in the core Niger Delta (home to the Ijaw and Ogoni indigenous, ethnic minorities). Since Great Britain granted Nigeria political independence on October 1, 1960, successive Nigerian governments (military and civilian) have been dominated by the majority ethnic groups (Hausa-Fulani, Yoruba, and Ibo). Significantly, the government adopted a socialist-based model of absolute state ownership over oil and gas resources. The socialist model formed the basis of Nigeria's business collaboration with multinational oil and gas corporations from Europe and the United States (notably Shell, Chevron Texaco, Agip, Exxon Mobil, Total, and Elf). This model is fraught with contradictions and has led to unacceptable consequences, including policies that allow exploitation of natural resources without reference to environmental sustainability. When oil was first struck in 1956 at Oloibori (Ijaw area), people thought it would bring prosperity and an improved quality of life. Sadly, the opposite has occurred. Forty-nine years of hardship, agonizing pain, debilitating anger, extreme poverty, poisoned rivers, destroyed occupations, devastated environment, and stunted growth of the youth are the negative impacts of oil and gas exploitation in the Niger Delta. In other words, oil and gas exploration and production have visited a full range of evils---socio-political, economic, and cultural---upon the indigenous Niger Delta people. Furthermore, the wealth extracted from the area is used by the state and multinational corporations to enhance their own wealth and quality of life. Revenue has been conspicuously looted and misappropriated by political leaders at the expense of the Niger Delta environment and its people. This confluence of exploitation and injury has led to social upheavals and armed rebellions, all capable of precipitating the disintegration of the country. In this

Prevalence and determinants of hypertension in Abia State Nigeria: results from the Abia State Non-Communicable Diseases and Cardiovascular Risk Factors Survey.

PubMed

Ogah, Okechukwu S; Madukwe, Okechukwu O; Chukwuonye, Innocent I; Onyeonoro, Ugochukwu U; Ukegbu, Andrew U; Akhimien, Moses O; Onwubere, Basden J C; Okpechi, Ikechi G

2013-01-01

Hypertension is the most common non-communicable disease and risk factor for heart failure, stroke, chronic kidney disease and ischemic heart disease in sub-Saharan Africa. Few population-based studies have been conducted recently in Nigeria and, in Abia State, no previous study has been conducted on the prevalence and correlates of hypertension among the populace. The purpose of our study was, therefore, to determine the prevalence and determinants of high blood pressure in Abia State, southeastern Nigeria. We hypothesise that high blood pressure burden is high in Abia State. The study was a community based cross-sectional house-to-house survey aimed at ascertaining the burden/prevalence of hypertension in the state as well as identifying related risk factors associated with them. The study was conducted in rural and urban communities in Abia State, Nigeria. Participants in the study were men and women aged > or =15 years and were recruited from the three senatorial zones in the state. A total of 2,999 respondents were selected for the survey and, 2,983 consented to be interviewed giving a response rate of 99.5%. The data for 2,928 participants were suitable for analysis. Of these, 1,399 (47.8%) were men. The mean age of the population was 41.7 +/- 18.5 years (range 18-96 years). About 54% of the population were < or =40 years. Ninety percent had at least primary education with about 47% having completed secondary education. Expectedly, 96% of the respondents were Ibos, the predominant tribe in the southeastern part of the country. Women had significantly higher BMI than the men. Similarly, waist circumference was also larger in women but waist-to-hip ratio was only significantly higher in women in the urban areas compared to those in rural areas. Thirty-one percent of all participants had systolic hypertension (33.5% in men and 30.5% in women). This sex difference was statistically different in the urban area. On the other hand, diastolic hypertension was 22

Real cell overlay measurement through design based metrology

NASA Astrophysics Data System (ADS)

Yoo, Gyun; Kim, Jungchan; Park, Chanha; Lee, Taehyeong; Ji, Sunkeun; Jo, Gyoyeon; Yang, Hyunjo; Yim, Donggyu; Yamamoto, Masahiro; Maruyama, Kotaro; Park, Byungjun

2014-04-01

Until recent device nodes, lithography has been struggling to improve its resolution limit. Even though next generation lithography technology is now facing various difficulties, several innovative resolution enhancement technologies, based on 193nm wavelength, were introduced and implemented to keep the trend of device scaling. Scanner makers keep developing state-of-the-art exposure system which guarantees higher productivity and meets a more aggressive overlay specification. "The scaling reduction of the overlay error has been a simple matter of the capability of exposure tools. However, it is clear that the scanner contributions may no longer be the majority component in total overlay performance. The ability to control correctable overlay components is paramount to achieve the desired performance.(2)" In a manufacturing fab, the overlay error, determined by a conventional overlay measurement: by using an overlay mark based on IBO and DBO, often does not represent the physical placement error in the cell area of a memory device. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion, caused by etching or CMP, also can be a source of the mismatch. Therefore, the requirement of a direct overlay measurement in the cell pattern gradually increases in the manufacturing field, and also in the development level. In order to overcome the mismatch between conventional overlay measurement and the real placement error of layer to layer in the cell area of a memory device, we suggest an alternative overlay measurement method utilizing by design, based metrology tool. A basic concept of this method is shown in figure1. A CD-SEM measurement of the overlay error between layer 1 and 2 could be the ideal method but it takes too long time to extract a lot of data from wafer level. An E-beam based DBM tool provides high speed to cover the whole wafer with high repeatability. It is enabled by using the design as a

Identification of thermal properties distribution in building wall using infrared thermography

NASA Astrophysics Data System (ADS)

Brouns, Jordan; Dumoulin, Jean

2016-04-01

[1] L. Ibos, J-P. Monchau, V. Feuillet, Y. Candau, A comparative study of in-situ measurement methods of a building wall thermal resistance using infrared thermography, in Proc. SPIE 9534, Twelfth International Conference on Quality Control by Artificial Vision 2015, 95341I (April 30, 2015); doi:10.1117/12.2185126 [2] Nassiopoulos, A., Bourquin, F., On-site building walls characterization, Numerical Heat Transfer, Part A : Applications, 63(3) :179 :200, 2013 [3] J. Brouns, Développement d'outils numériques pour l'audit énergétique des bâtiments, PhD thesis, Université Paris-Est, SIE, 2014 [4] J.-L. Lions, Contrôle optimal de systèmes gouvernés par des équations aux dérivées partielles. Book, Dunod editor, 1968.

Active and passive infrared thermography applied to the detection and characterization of hidden defects in structure

NASA Astrophysics Data System (ADS)

Dumoulin, Jean

2013-04-01

direct thermal modelling or inverse thermal modelling will be presented and discussed. Conclusion and perspectives will be proposed in link with structure monitoring or cultural heritage applications. References [1] Maldague, X.P.V. "Theory and practice of infrared technology for non-destructive testing", John Wiley & sons Inc., 2001. [2] Dumoulin J. and Averty R., « Development of an infrared system coupled with a weather station for real time atmospheric corrections using GPU computing: Application to bridge monitoring", QIRT 2012, Naples, Italy, June 2012. [3] J. Dumoulin, L. Ibos, C. Ibarra-Castanedo, A Mazioud, M. Marchetti, X. Maldague and A. Bendada, « Active infrared thermography applied to defect detection and characterization on asphalt pavement samples: comparison between experiments and numerical simulations », Journal of Modern Optics, Special Issue on Advanced Infrared Technology and Applications, Volume 57, Issue 18, October 2010 , pages 1759 - 1769, doi:10.1080/09500340.2010.522738 [4] F. Taillade, M. Quiertant, K. Benzarti, J. Dumoulin, Ch. Aubagnac, Chapter 9: "Nondestructive Evaluation of FRP Strengthening Systems Bonded on Concrete Structures using Pulsed Stimulated Infrared Thermography ", pp 193-208, Book title "Infrared Thermography", Editeur Raghu V. Prakash, ISBN 978-953-51-0242-7, Intech, open access at the following address http://www.intechopen.com/books/editor/infrared-thermography, march 2012. [5] Cooley J.W., Tukey J.W., "An algorithm for the machine calculation of complex Fourier series", Mathematics of Computation, vol. 19, n° 90, 1965, p. 297-301. [6] Rajic N., "Principal component thermography for flaw contrast enhancement and flaw depth characterization in composite structures", Composite Structures, vol 58, pp 521-528, 2002. [7] Marinetti S., Grinzato E., Bison P. G., Bozzi E., Chimenti M., Pieri G. and Salvetti O. "Statistical analysis of IR thermographic sequences by PCA," Infrared Physics & Technology vol 46 pp 85-91, 2004.

Configuration and Intraseasonal Duration of Interannual Anomalies of the Great Plains Low-Level Jet

NASA Technical Reports Server (NTRS)

Helfand, H. M.

2002-01-01

Despite the fact that the low-level jet of the southern Great Plains (the GPLLJ) of the U.S. is primarily a nocturnal phenomenon that virtually vanishes during the daylight hours, it is one of the most persistent and stable climatological features of the low-level continental flow during the warm-season months, May through August. We have used significant-level data to validate the skill of the GEOS-1 Data Assimilation System (DAS) in realistically detecting this jet and inferring its structure and evolution. We have then carried out a 15-year reanalysis with the GEOS-1 DAS to determine its climatology and mean diurnal cycle and to study its interannual variability. Interannual anomalies of the meridional flow associated with the GPLLJ are much smaller than the mean diurnal fluctuations, than random intraseasonal anomalies, and than the mean wind itself. There are three maxima of low-level meridional flow variance over the Great Plains and the Gulf of Mexico: a 1.2 m2 s-2 peak over the southeast Texas, to the east and south of the mean velocity peak, a 1.0 m2 s-2 peak over the western Gulf of Mexico, and a .8 m2 s-2 peak over the upper Great Plains (UGP), near the Nebraska/South Dakota border. Each of the three variance maxima corresponds to a spatially coherent, jet-like pattern of low-level flow interannual variability. There are also three dominant modes of interannual variability corresponding to the three variance maxima, but not in a simple one-to-one relationship. Cross-sectional profiles of mean southerly wind over Texas remain relatively stable and recognizable from year to year with only its eastward flank showing significant variability. This variability, however, exhibits a distinct, biennial oscillation during the first six to seven years of the reanalysis period and only then. This intermittent biennial oscillation (IBO, one of the three modes discussed in the previous paragraph) in the lowlevel flow is restricted to the region surrounding eastern

PREFACE: Preface

NASA Astrophysics Data System (ADS)

Ye, Chaohui; Wang, Zhong Lin; Zhou, Bingkun

2011-02-01

whose papers are being published in this volume of the Journal of Physics: Conference Series. The proceedings are divided into six sections according to different technical areas: Laser Technology and Applications (LTA) Nano-enabled Energy Technologies and Materials (NETM) Optoelectronic Devices and Integration (OEDI) Optoelectronic Sensing and Imaging (OSI) Solar Cells, Solid State Lighting and Information Display Technologies (SSID) Tera-Hertz Science and Technology (THST) Wuhan, PR ChinaDecember, 2010 Chaohui YeZhong Lin WangBingkun ZhouConference Chairs The 3rd International Photonics and OptoElectronics Meeting (POEM 2010)November 2-5, 2010Wuhan, China Supporters:Ministry of Education of China (MOE)State Administration of Foreign Experts Affairs (SAFEA)National Natural Science Foundation of China (NSFC) Sponsors:Huazhong University of Science and Technology (HUST)China Hubei Provincial Science Technology Department (HBSTD)Wuhan East Lake National Innovation Model Park Co-operating Societies:Institute of Physics (IOP)American Institute of Physics (AIP)International Biomedical Optics Society (IBOS)Laser Institute of America (LIA)Optical Society of America (OSA)IEEE Photonics Society (Singapore and Hongkong Chapters)Chinese Optical Society (COS) Organizer:Wuhan National Laboratory for Optoelectronics (WNLO) 1. LASER TECHNOLOGY AND APPLICATIONS (LTA)Editors:Peixiang Lu, Wuhan National Laboratory for Optoelectronics (China)Katsumi Midorikawa, Extreme Photonics Research Group, RIKEN (Japan)Bernd Wilhelmi, Jenoptik AG, Jena (Germany) 2. NANO-ENABLED ENERGY TECHNOLOGIES AND MATERIALS (NETM)Editors:Zhong Lin Wang, Wuhan National Laboratory for Optoelectronics (China) and Georgia Institute of Technology (USA)Guozhen Shen, Wuhan National Laboratory for Optoelectronics (China) 3. OPTOELECTRONIC DEVICES AND INTEGRATION (OEDI)Editors:Chinlon Lin, Bell Laboratory (USA)Jesper Moerk, Technical University of Denmark (Denmark)Xun Li, McMaster University (Canada)Xinliang Zhang, Wuhan

PREFACE: Preface

NASA Astrophysics Data System (ADS)

Luo, Qingming; Wang, Lihong V.; Tuchin, Valery V.

2011-02-01

Qingming LuoLihong V WangValery V TuchinConference Chairs 9th International Conference on Photonics and Imaging in Biology and Medicine (PIBM 2010)2-5 November 2010Wuhan, China EditorsQingming Luo, Huazhong University of Science and Technology (China)Lihong V Wang , Washington University in St. Louis (USA)Valery V Tuchin, Saratov State University (Russia) Sponsored and Organized byHuazhong University of Science and Technology (China)Wuhan National Laboratory for Optoelectronics (China)Britton Chance Center for Biomedical Photonics (China) Technical Co-sponsored byIBOS-International Biomedical Optics SocietyThe Chinese Optical SocietyThe Biophysical Society of China Co-organized byKey Laboratory of Biomedical Photonics, Ministry of Education (China)Virtual Research Center of Biomedical Photonics, Ministry of Education (China)Hubei Bioinformatics and Molecular Imaging Key Laboratory (China) CONFERENCE COMMITTEES Honorary ChairsBritton Chance, University of Pennsylvania (USA)Bingkun Zhou, Tsinghua University (China) Conference ChairsQingming Luo, Huazhong University of Science and Technology (China)Lihong V Wang , Washington University in St. Louis (USA)Valery V Tuchin, Saratov State University (Russia) Advisory CommitteeSydney Brenner, The Salk Institute in La Jolla, California (USA)Howard Chen, K&L Gates (USA)Jing Cheng, Tsinghua University (China)Shu Chien, University of California, San Diego (USA)Paul Ching-Wu Chu, University of Houston (USA)Aaron Ciechanover, Technion-Israel Institute of Technology, Haifa (Israel)A Stephen Dahms, Alfred E Mann Foundation for Biomedical Engineering (USA)Da Hsuan Feng, National Cheng Kung University (Taiwan, China)Steven R Goodman, SUNY Upstate Medical University (USA)Barry Halliwell, National University of Singapore (Singapore)John Hart, The University of Texas at Dallas (USA)George Radda, Agency for Science, Technology and Research (A*STAR) (Singapore)Zihe Rao, Nankai University (China)Brian M Salzberg, University of Pennsylvania (USA