Quantitative Observations Research Articles

Rule-guided human classification of Volunteered Geographic Information

During the last decade, web technologies and location sensing devices have evolved generating a form of crowdsourcing known as Volunteered Geographic Information (VGI). VGI acted as a platform of spatial data collection, in particular, when a group of public participants are involved in collaborative mapping activities: they work together to collect, share, and use information about geographic features. VGI exploits participants’ local knowledge to produce rich data sources. However, the resulting data inherits problematic data classification. In VGI projects, the challenges of data classification are due to the following: (i) data is likely prone to subjective classification, (ii) remote contributions and flexible contribution mechanisms in most projects, and (iii) the uncertainty of spatial data and non-strict definitions of geographic features. These factors lead to various forms of problematic classification: inconsistent, incomplete, and imprecise data classification. This research addresses classification appropriateness. Whether the classification of an entity is appropriate or inappropriate is related to quantitative and/or qualitative observations. Small differences between observations may be not recognizable particularly for non-expert participants. Hence, in this paper, the problem is tackled by developing a rule-guided classification approach. This approach exploits data mining techniques of Association Classification (AC) to extract descriptive (qualitative) rules of specific geographic features. The rules are extracted based on the investigation of qualitative topological relations between target features and their context. Afterwards, the extracted rules are used to develop a recommendation system able to guide participants to the most appropriate classification. The approach proposes two scenarios to guide participants towards enhancing the quality of data classification. An empirical study is conducted to investigate the classification of grass-related features like forest, garden, park, and meadow. The findings of this study indicate the feasibility of the proposed approach.

Calving of Fuerza Aérea Glacier (Greenwich Island, Antarctica) observed with terrestrial laser scanning and continuous video monitoring

ABSTRACTA short-term series of quantitative observations of calving activity of Fuerza Aérea Glacier (Greenwich Island, the South Shetland Islands, Antarctica) was conducted in order to test new methods of monitoring calving. The volume of single calving events was quantified by combining terrestrial laser scanning (TLS) surveys with continuous video recording of the ice front. An empirical formula for area/volume scaling of the calved ice block was proposed based on the TLS measured calved ice volume and the calved ice front area obtained by manual delineation on the images acquired with the video camera. This combination of methods proves to be a valuable tool for glacier monitoring, providing both high-temporal resolution and precise quantitative measurements of the calving volume. The size distribution of calving events is best approximated by a power law and within the short period of observations (14 d) calving was found to be an intrinsic process not dependent on environmental forcings. Over the period of 21 January–04 February 2013 the ice flow velocity at the terminus of Fuerza Aérea Glacier was 0.26 ± 0.07 m d−1and the calving rate was 0.41 ± 0.07 m d−1.

KOMBINASI PENAMBAHAN UREA DAN EM-4 TERHADAP KUALITAS BOKASHI CAIR

The objectives of the study is to determine the effect of EM-4 and Urea addition on the liquid Bokashi quality of chicken manure. The field research was conducted at California Papaya Farm Pulau Sari, Pelaihari, and the nutrient levels of liquid Bokashi are then analyzed in the laboratory of PPLH Banjarbaru. The research was conducted from February to March 2015. It used Complete Randomized Design (CRD) of factorial pattern 2 with three levels of treatment and three replications, the first factor is the addition of urea, consisting of three levels those are 0 g, 7.5 g, 15 g, the second factor is the addition of EM-4, consisting of three levels those are 0 ml, 25 ml, 50 ml, so that the number of trial units becomes 27 units. The variables measured are the Levels of Nitrogen (N), Phosphorous (P), Potassium (K), C-Organic, temperature, pH, color, smell, and texture. Quantitative observation data were analyzed using ANOVA and Duncan's Multiple Range Test (DMRT), while the qualitative observation data were analyzed using Kruskal-Wallis test. The results showed that the interaction between the addition of EM-4 and Urea were able to increase levels of nutrients N, P, K, C-Organic, and the temperature of the liquid Bokashi. Overall obtained treatment provision of EM-4 25 ml and 15 g Urea is the best treatment among other treatments. The addition of EM-4 was able to increase the levels of N, K, C-Organic and liquid Bokashi temperature, but it is unable to increase levels of the element P. Giving Urea can increase the levels of nutrients N, P, K, C-Organic, and the temperature of the liquid Bokashi. In observation of the organoleptic treatment with the addition of EM-4 and Urea, it tends to produce materials with better color, smell, and texture than the control treatment.

Mechanical Properties of Solid Electrolyteinterphase Layer in Li-Ion Batteries: Experimental and Computationalstudies

The mechanical instability of the Solid Electrolyte Interphase (SEI) layer in lithium ion (Li-ion) batteries causes significant side reactions resulting in Li-ion consumption and cell impedance rise by forming further SEI layers, which eventually leads to battery capacity fade and power fade. In this work, the SEI elasticity was studied both experimentally and computationally. To characterize the SEI elasticity, the SEI layer formed on a HOPG electrode in a LiPF6 / EC+DMC electrolyte has been investigated using PF-QNM and atomistic calculations. Both experimental and computational results have shown that SEI elasticity is strongly affected by the SEI chemical composition. It was observed that the inner layer is stiffer than the outer layer. The measured Young’s moduli were mostly in the range of 0.2 to 4.5 GPa, while some values above 80 GPa were also observed. This wide variation of the observed elastic modulus was elucidated by atomistic calculations with a focus on chemical and structural analysis. The numerical analysis showed the Young’s moduli ranged from 2.4 GPa to 58.1 GPa in the order of the polymeric, organic, and amorphous inorganic components. The crystalline inorganic component (LiF) showed the highest value (135.3 GPa) among the SEI species. This quantitative observation on the elasticity of individual components of the SEI layer must be essential to analyzing the mechanical behavior of the SEI layer and to optimizing and controlling it. The findings from this work can be used in controlling the SEI layer to minimize damage to the SEI layer. The mechanical stability (adhesion, elasticity, etc.) of the SEI layer can be achieved by changing formation conditions and electrolytes (salts, solvents, and additives). For instance, the formation of an inorganic layer with an amorphous feature, and of a PEO polymeric layer rather than an EC- or DMC-based organic layer would be desirable for forming a flexible SEI layer.

Ecological Responses to Extreme Flooding Events: A Case Study with a Reintroduced Bird.

In recent years numerous studies have documented the effects of a changing climate on the world’s biodiversity. Although extreme weather events are predicted to increase in frequency and intensity and are challenging to organisms, there are few quantitative observations on the survival, behaviour and energy expenditure of animals during such events. We provide the first data on activity and energy expenditure of birds, Eurasian cranes Grus grus, during the winter of 2013–14, which saw the most severe floods in SW England in over 200 years. We fitted 23 cranes with telemetry devices and used remote sensing data to model flood dynamics during three consecutive winters (2012–2015). Our results show that during the acute phase of the 2013–14 floods, potential feeding areas decreased dramatically and cranes restricted their activity to a small partially unflooded area. They also increased energy expenditure (+15%) as they increased their foraging activity and reduced resting time. Survival did not decline in 2013–14, indicating that even though extreme climatic events strongly affected time-energy budgets, behavioural plasticity alleviated any potential impact on fitness. However under climate change scenarios such challenges may not be sustainable over longer periods and potentially could increase species vulnerability.

Technical Staff Positions and Technology related Tasks: A Study of University Libraries in Pakistan

This study investigated the current state of technical staff positions in the central libraries of leading universities in Pakistan. Multiple quantitative methods were adopted to carry out this study. Quantitative data about technical staff positions were retrieved from organizational documents such as service structure documents, organizational charts and budgetary documents. Principal author carried out quantitative observations and informal discussions with library executives in order to measure the levels of working of technical staff positions and alternatives adopted by libraries to carry out technical tasks. This study found that fifty percent of the libraries have not created any technical staff positions and automation related tasks are being performed by library professionals with the cooperation of vendors who have provided the library software. Of the nine positions for technical staff sanctioned by the libraries, only two were found to have been filled. Centralized mode of operation has been adopted for technical staff personnel. Only one library has given the additional charge of section head to the technology expert who is also managing technical tasks at organizational level.

What Geoscience Experts And Novices Look At, And What They See, When Viewing Data Visualizations

This study examines how geoscience experts and novices make meaning from an iconic type of data visualization: shaded relief images of bathymetry and topography. Participants examined, described, and interpreted a global image, two high-resolution seafloor images, and 2 high-resolution continental images, while having their gaze direction eye-tracked and their utterances and gestures videoed. In addition, experts were asked about how they would coach an undergraduate intern on how to interpret this data. Not unexpectedly, all experts were more skillful than any of the novices at describing and explaining what they were seeing. However, the novices showed a wide range of performance. Along the continuum from weakest novice to strongest expert, proficiency developed in the following order: making qualitative observations of salient features, making simple interpretations, making quantitative observations. The eye-tracking analysis examined how the experts and novices invested 20 seconds of unguided exploration, after the image came into view but before the researcher began to ask questions. On the cartographic elements of the images, experts and novices allocated their exploration time differently: experts invested proportionately more fixations on the latitude and longitude axes, while students paid more attention to the color bar. In contrast, within the parts of the image showing the actual geomorphological data, experts and novices on average allocated their attention similarly, attending preferentially to the geologically significant landforms. Combining their spoken responses with their eye-tracking behavior, we conclude that the experts and novices are looking in the same places but “seeing” different things.

A contribution to the understanding of cavitation effects on droplet formation through a quantitative observation on breakup of liquid jet

Cavitation is an effective way to enhance fuel jet breakup and evaporation in order to improve the quality of fuel spray in the combustion chambers and hence mitigate engines exhausts emissions without compromising the performance and fuel economy. However, what happened inside the nozzle and how it affects the breakup and atomization characteristics of the emerged liquid jet is still unknown. This study was conducted to quantitatively investigate the macroscopic characteristics of the cavitation-driven atomization through a two dimensional transparent nozzle, which was designed to trigger more cavitation on one side than the other. The cavitation occurrence inside the nozzle and the spray near the nozzle exit were directly imaged and recorded by a high-speed visualization system. As a result, the following conclusions are obtained. (1) The liquid jet breakup characteristics are strongly affected by the cavitation extent inside nozzle and better atomization characteristics are obtained on the side where cavitation is more promoted. (2) Supercavitation regime, where bubbles are swept outside the nozzle exit, is an optimal point at which the nozzle internal flow structure and the atomization characteristics of resulting jet changes significantly. These results provide insightful information for understanding the breakup mechanism of a cavitation-driven liquid jet and modeling a supercavitation spray.

Leaf venation studies of 30 varieties ofMangifera indicaL. (Anacardiaceae)

Leaf morphological characters are important, especially for plant identification and classification. Leaf morphological characters are mainly used for classifying a particular genus, species and varieties, but leaf architectural patterns are not much studied. This study has been undertaken for identification of 30 Mangifera indica L. varieties based on venation characteristics. The results showed that pinnate type are common in the Kaju, Totapuri and Badshahpasand varieties, which are usually characterized by thick primary veins. Secondary veins were of camptodromous type. Minor venation was measured up to five orders and all varieties studies showed fimbriate venation. Other qualitative characters of secondary vein (angle of divergence, course, intersecondary vein), tertiary vein (pattern), higher order venation (course), veinlet branching, areole development, areole arrangement and areole shape were undertaken. Quantitative observations included number of areoles per mm2, average size of areole per mm2,...

Quality Evaluation of Image Steganography Techniques: A Heuristics based Approach

Steganography refers to techniques that hide information inside innocuous looking objects known as “Cover Objects” such that its very existence remains concealed to any unintended recipient. Images are pervasive in day to day applications and have high redundancy in representation. Thus, they are appealing contenders to be used as cover objects. There are a large number of image steganography techniques proposed till date but negligible research has been done on the development of a standard quality evaluation model for judging their performance. Existence of such a model is important for fueling the development of superior techniques and also paves the way for the improvement of the existing ones. However, the common quality parameters often considered for performance evaluation of an image steganography technique are insufficient for overall quantitative evaluation. This paper proposes a rating scale based quality evaluation model for image steganography algorithms that utilizes both quantitative parameters and observation heuristics. Different image steganography techniques have been evaluated using proposed model and quantitative performance scores for each of the techniques have been derived. The scores have been observed to be in accordance with actual literature and the system is simple, efficient and flexible.

Characterization of structural inhomogeneity in Al88Ce8Co4 metallic glass

Structural inhomogeneity is found to be a promising way to overcome intrinsic brittleness and to improve the plasticity of metallic glasses (MGs), although such inhomogeneity has not been well-understood. In this study, quantitative observations and theoretical explanations on the structural inhomogeneity were presented for Al88Ce8Co4 MG. Applying a technique called energy filtered electron diffraction (EFED), different medium-range orders (MROs) reflected from conspicuous and inconspicuous prepeaks, were observed, which, following reduced pair distribution functions obtained from the EFED measurement, correspond to different short-range orders (SROs). Then using reverse Monte Carlo (RMC) simulation, the structural inhomogeneity is attributed to diversity of AlCo clusters, which lead to loosely and densely packed local atomic structures and contribute to soft and hard regions, as evidenced by synchrotron radiation X-ray diffraction, dynamic mechanical analysis and nano-indentation. The obtained structural essence of intrinsic inhomogeneity in MGs lays the foundation for further understanding and designing MGs with high plasticity, by adjusting properly inhomogeneous structure.

The Quantitative Observation of Interbody Fusion with Local Autogenous Bone Harvested from Single Interlaminar Fenestration in PLIF

Introduction Local autogenous bone (LABORATORY) harvested from interlaminar fenestration or total facetectomy has been widely applied in interbody fusion of lumbar disc degenerative diseases (DDD) with satisfactory clinical results. However, there was lack of weight and volume observation of LABORATORY harvested from single interlaminar fenestration(SIF). The aim of this study was to quantitative observe the interbody fusion feasibility with LABORATORY harvested from SIF in PLIF. Materials and Methods 107 patients were undergone PLIF only by LABORATORY+one cage at L4/5 and/or L5S1 due to DDD. The weight and volume of LABORATORY from SIF were measured by analytical balance and 5ml disposal sterile syringe. The height of cages used intraoperative were recorded. The area of endplate (Se) and the contact area (Sc) between the cartilaginous endplate and LABORATORY +cage at every intervertebral space was measured and calculated by PACS of CT workstation. The clinical results and fusion status were estimated by JOA score and 3D-CT at 12, 18 and 24 months postoperative. Results 113 segments of 107 patients were successfully fused only by LABORATORY harvested from SIF. The weight and volume of LABORATORY from SIF showed no significant differences at different ages, genders, segments and type of DDD, and the same result exists about Se and the height of interbody space in L4/5 or L5S1 segments. The mean volume and weight of LABORATORY were 3.1ml and 3.7 g from SIF. The packing ratio (PR) of LABORATORY+one cage was 38.1%. The volume and weight to reach 30% PR needed ~2.5ml and 3.0 g LABORATORY. 94 cases (98 segments) were followed up for average 24 months postoperative. The improvement rate of JOA score was 82.5%, and the fusion rate was 92.9%. Conclusion SIF can provide enough LABORATORY for one interbody fusion in PLIF. The average volume and weight of LABORATORY from SIF were 3.1ml and 3.7 g respectively. 38% PR, including one cage, is achievable at fusion segment in present study. 2.5 ml (3.0 g) LABORATORY+one cage can perform ~30% PR.

PENERAPAN METODE SIMULASI UNTUK MENINGKATKAN AKTIVITAS DAN HASIL BELAJAR PKN SISWA DI SD NEGERI 187/IV KOTA JAMBI

This study presents a research report on using simulation method to improve the activity and the students’ learning result improving students’ Learning results on PKn. The objective was to find out whether the activity and the students’ learning result improved when they are taught by using Video. It was conducted using classroom action research method. The subject of the study was the Grade IV students of SDN 187/IV Kota Jambi which is located on Jln. Adi Sucipto RT 05 Kecamatan Jambi Selatan, and the number of the students were 9 persons. The instruments used were test as quantitative data and observation, interview, and questionnaire were used as qualitative data. In analyzing the data, the mean of the students’ score for the on first cycle was 74.11 and the mean on cycle two was 78.00 and the mean of the third cycle was 84.7. Then it can be concluded that the use of simulation as a learning method can improve the students’ activity and students’ learning result. It is suggested that teachers should apply simulation method as a learning method to improve students’ activity and students’ learningresult on PKn.Keywords : PKn, students’ activity, students’ learning results, simulation method

Reaction Distribution in Mixed-Conducting SOFC Cathodes Investigated with Patterned Thin Film Electrodes

Solid oxide fuel cells (SOFCs) recently attract attentions as one of promising high-efficiency energy-conversion devices. For enhancement of the cell performance or low temperature operation, oxygen reduction kinetics on the cathode should be improved. In a mixed ionic-electronic conducting (MIEC) cathode, such as (La,Sr)CoO3 - d and (La,Sr)(Co,Fe)O3 - d , reaction area for the oxygen reduction reaction is not limited to only the electrode/electrolyte/gas interface (the triple phase boundary) but also distributes to the oxide surfaces within a certain distance from the electrode/electrolyte interface, i.e. within an effective reaction area. However, there are no reports which directly observe such a reaction distribution by experimental manners, as far as the authors know. For experimental and quantitative observation of the reaction distribution in an MIEC SOFC electrode, a patterned thin film electrode, which is a kind of the columnar electrode simplifying a porous electrode, was used in this work [1]. As a typical MEIC electrode material, La0.6Sr0.4CoO3- d was chosen and deposited on a Ce0.9Gd0.1O1.95 electrolyte. In an MEIC cathode, it is believed the oxygen chemical potential decreases in the area where the electrochemical oxygen reduction reaction takes place. Thus, reaction distribution can be understood if the distribution of oxygen potential is revealed. In this work, operando micro X-ray absorption spectroscopy (XAS) technique was applied to evaluate the oxygen potential was evaluated as a function of the distance from the electrode/electrolyte interface. In this operando technique, X-ray absorption spectra could be obtained with a spatial resolution higher than 1 mm at elevated temperature (~1073 K) while controlling atmospheric condition and passing the electronic current through the cell. The effective reaction area could be estimated, for instance, 20 mm from the electrode/electrolyte interface in the case of the La0.6Sr0.4CoO3- d patterned thin film electrode having a thickness of 400 nm at 973 K under 1 bar of p(O2) and -220 mV of cathodic overpotential. The effective reaction area tended to expand with decreasing ambient p(O2) and increasing cathodic overpotential.

Impact of bifurcation angle and other anatomical characteristics on blood flow – A computational study of non-stented and stented coronary arteries

The hemodynamic influence of vessel shape such as bifurcation angle is not fully understood with clinical and quantitative observations being equivocal. The aim of this study is to use computational modeling to study the hemodynamic effect of shape characteristics, in particular bifurcation angle (BA), for non-stented and stented coronary arteries.Nine bifurcations with angles of 40°, 60° and 80°, representative of ±1 SD of 101 asymptomatic computed tomography angiogram cases (average age 54±8 years; 57 females), were generated for (1) a non-stented idealized, (2) stented idealized, and (3) non-stented patient-specific geometry. Only the bifurcation angle was changed while the geometries were constant to eliminate flow effects induced by other vessel shape characteristics. The commercially available Biomatrix stent was used as a template and virtually inserted into each branch, simulating the T-stenting technique. Three patient-specific geometries with additional shape variation and ±2 SD BA variation (33°, 42° and 117°) were also computed. Computational fluid dynamics (CFD) analysis was performed for all 12 geometries to simulate physiological conditions, enabling the quantification of the hemodynamic stress distributions, including a threshold analysis of adversely low and high wall shear stress (WSS), low time-averaged WSS (TAWSS), high spatial WSS gradient (WSSG) and high Oscillatory Shear Index (OSI) area.The bifurcation angle had a minor impact on the areas of adverse hemodynamics in the idealized non-stented geometries, which fully disappeared once stented and was not apparent for patient geometries. High WSS regions were located close to the carina around peak-flow, and WSSG increased significantly after stenting for the idealized bifurcations. Additional shape variations affected the hemodynamic profiles, suggesting that BA alone has little effect on a patient׳s hemodynamic profile. Incoming flow angle, diameter and tortuosity appear to have stronger effects.This suggests that other bifurcation shape characteristics and stent placement/strategy may be more important than bifurcation angle in atherosclerotic disease development, progression, and stent outcome.

Capacity building for field inspections: A comprehensive assessment tool for monitoring structural integrity and sediment capture performance of T-head groins

Objectives of this study were to develop a field assessment tool (i.e., criteria and rubrics) which can be used during periodic inspections of T-head groins, specifically those constructed for controlling coastal erosion along the Black Sea coastline in northern Turkey. The assessment criteria were developed for evaluating both the structural characteristics and the sediment capture performance. Detailed assessment criteria including location specific characteristics (i.e., coastal conditions, water/wave characteristics, abutting factors, abutting factors, land use, and potential natural and man-made hazard factors) and appropriate guidelines which can be used for qualitative and quantitative observations were developed. The field inspection can be used for performance comparison of the structures located at different locations, understanding the effects of location specific factors on sediment capture performance, and specific maintenance requirements. The tool was used to evaluate and compare the performance of 31 T-head groins located in three neighboring groin fields on the eastern Black Sea coast of Turkey.

Polymerizing dopamine onto Q-graphene scaffolds towards the fluorescent nanocomposites with high aqueous stability and enhanced fluorescence for the fluorescence analysis and imaging of copper ions

Dopamine (DA) was polymerized onto the scaffolds of Q-graphene (QG) nanomaterials by the one-pot H2O2 oxidation under the microwave radiations. The so yielded fluorescent QG@PDA nanocomposites could present the high aqueous stability and photostability. Unexpectedly, they could display the enhanced fluorescence and photoluminescence, which are about 1.5-time larger than those of the fluorescent PDA nanoparticles. More importantly, the fluorescence and photoluminescence of QG@PDA nanocomposites could be specifically quenched by Cu2+ ions, which could be efficiently restored by using the Cu2+-chelating ligand (i.e., EDTA). The developed fluorimetry was applied to detect Cu2+ ions in wastewater with the detection limit down to about 10nM. The feasibility of the quantitative observations by the fluorescence imaging for Cu2+ ions could also be expected. This QG@PDA-based fluorimetry for Cu2+ ions is rapid, sensitive, selective, and field-applicable, promising the potential applications in the environmental and industrial fields.

Cell wall accumulation of fluorescent proteins derived from a trans-Golgi cisternal membrane marker and paramural bodies in interdigitated Arabidopsis leaf epidermal cells

In most dicotyledonous plants, leaf epidermal pavement cells develop jigsaw puzzle-like shapes during cell expansion. The rapid growth and complicated cell shape of pavement cells is suggested to be achieved by targeted exocytosis that is coordinated with cytoskeletal rearrangement to provide plasma membrane and/or cell wall materials for lobe development during their morphogenesis. Therefore, visualization of membrane trafficking in leaf pavement cells should contribute an understanding of the mechanism of plant cell morphogenesis. To reveal membrane trafficking in pavement cells, we observed monomeric red fluorescent protein-tagged rat sialyl transferases, which are markers of trans-Golgi cisternal membranes, in the leaf epidermis of Arabidopsis thaliana. Quantitative fluorescence imaging techniques and immunoelectron microscopic observations revealed that accumulation of the red fluorescent protein occurred mostly in the curved regions of pavement cell borders and guard cell ends during leaf expansion. Transmission electron microscopy observations revealed that apoplastic vesicular membrane structures called paramural bodies were more frequent beneath the curved cell wall regions of interdigitated pavement cells and guard cell ends in young leaf epidermis. In addition, pharmacological studies showed that perturbations in membrane trafficking resulted in simple cell shapes. These results suggested possible heterogeneity of the curved regions of plasma membranes, implying a relationship with pavement cell morphogenesis.

Numerical Modelling of Turbulent Flow Structures in a Trough Blowout

Smyth, T.A.G. and Hesp, Patrick A., 2016. Numerical Modelling of Turbulent Flow Structures in a Blowout. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 328–332. Coconut Creek (Florida), ISSN 0749-0208.Blowouts are erosional landforms often formed on coastal sand dunes by the deflation of sediment by wind flow. Quantitative observations of wind flow within blowouts aided by the deployment of smoke-bombs, have noted that temporal and spatial variations in sediment transport occur with the presence of turbulent flow structures. However because of the discrete nature of anemometry data, the presence of flow structures has been difficult to quantify and our understanding remains largely conceptual. This study presents a detailed investigation of turbulent flow structures within a trough blowout using high resolution, three-dimensional computational fluid dynamic modelling. We show that when incident wind flow was parallel to the blowout axis, only limited flow steering took place but a well-defined near surface jet developed along the deflation basin. Conversely when incident wind flow was oblique to the axis of the blowout wind flow became steered along the axis of the blowout but no near surface jet was produced. During neither incident wind direction were corkscrew or helicoidal vortices produced. Our study concludes that the incident wind flow direction is critical to the effectiveness of a trough blowout as a corridor for wind-blown sediment. While wind from a range of oblique angles may be steered along the axis of blowout, its relative effectiveness of eroding and transporting sediment beyond the deflation basin and erosional walls is much reduced compared to axis parallel wind flows of the same incident wind speed.

Effect of temperature and O2 pressure on the gaseous species produced during combustion of aluminum

Effect of temperature and O2 pressure on the gaseous species produced during the combustion of aluminum is studied using first principles calculations and considering the thermodynamics of the gas phase equilibrium composed of Al, O2, AlO, Al2O, AlO2, Al2O2 and Al2O3. AlO partial pressure dominates all the range of O2 pressures/temperatures. AlO2 is the second most abundant species at low to intermediate temperatures (1200⿿1727°C) and Al2O at higher temperatures (⿼3300°C). Al2O and Al2O2 are stable when ionized into mass spectrometer. Al2O3, AlO2 and, to a lesser extent AlO, will decompose, hindering their quantitative observation using this technique.