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1

Dissolved Concentrations of PAHs and PCBs Are Often Over-predicted Using Sediment Concentrations and Literature Koc Values  

EPA Science Inventory

There is an increasing amount of chemical and biological evidence that using sediment concentrations and commonly applied Koc values frequently overpredicts interstitial water concentrations of HOCs, and thereby overestimates uptake and/or effects of those chemicals on exposed or...

2

Valuing a Log: Alternative Approaches.  

National Technical Information Service (NTIS)

The gross value of products that can be manufactured from a tree is the starting point for a residual-value appraisal of a forest operation involving the harvest of trees suitable for making forest products. The amount of detail in a model of gross produc...

R. V. Nagubadi R. D. Fight R. J. Barbour

2003-01-01

3

Partitioning studies of dioxin between sediment and water: The measurement of Koc for Lake Ontario sediment  

SciTech Connect

A desorption experiment is described in which the sediment-to-water partition coefficient for 2,3,7,8-tetrachlorodibenzo-p-dioxin is measured for a sample from Lake Ontario. After a contact period of 4 days, the logarithm of the partition coefficient on an organic carbon basis, LogKoc, ranges from 7.25 to 7.59. Information on the partitioning behavior of dioxin between water and dissolved or suspended matter derived from the sediment is provided.

Lodge, K.B.; Cook, P.M.

1989-01-01

4

The effect of different log P algorithms on the modeling of the soil sorption coefficient of nonionic pesticides.  

PubMed

Collecting data on the effects of pesticides on the environment is a slow and costly process. Therefore, significant efforts have been focused on the development of models that predict physical, chemical or biological properties of environmental interest. The soil sorption coefficient normalized to the organic carbon content (Koc) is a key parameter that is used in environmental risk assessments. Thus, several log Koc prediction models that use the hydrophobic parameter log P as a descriptor have been reported in the literature. Often, algorithms are used to calculate the value of log P due to the lack of experimental values for this property. Despite the availability of various algorithms, previous studies fail to describe the procedure used to select the appropriate algorithm. In this study, models that correlate log Koc with log P were developed for a heterogeneous group of nonionic pesticides using different freeware algorithms. The statistical qualities and predictive power of all of the models were evaluated. Thus, this study was conducted to assess the effect of the log P algorithm choice on log Koc modeling. The results clearly demonstrate that the lack of a selection criterion may result in inappropriate prediction models. Seven algorithms were tested, of which only two (ALOGPS and KOWWIN) produced good results. A sensible choice may result in simple models with statistical qualities and predictive power values that are comparable to those of more complex models. Therefore, the selection of the appropriate log P algorithm for modeling log Koc cannot be arbitrary but must be based on the chemical structure of compounds and the characteristics of the available algorithms. PMID:23886539

dos Reis, Ralpho Rinaldo; Sampaio, Silvio César; de Melo, Eduardo Borges

2013-10-01

5

log gf values for astrophysically important transitions Fe II  

NASA Astrophysics Data System (ADS)

Aims: In a recent measurement, Meléndez & Barbuy (2009, A&A, 497, 611) report accurate log gf values for 142 important astrophysical lines with wavelengths in the range 4000 Å to 8000 Å. Their results include both solar and laboratory measurements. In this paper, we describe a theoretical study of these lines. Methods: The CIV3 structure codes, combined with our "fine-tuning" extrapolation process, are used to undertake a large-scale CI calculation involving the lowest 262 fine-structure levels belonging to the 3d64s, 3d7, 3d54s2, 3d64p, and 3d54s4p configurations. Results: We find that many of the 142 transitions are very weak intercombination lines. Other transitions are weak because the dominant configurations in the two levels differ by two orbitals. Conclusions: The comparison between our log gf values and the experimental values generally shows good agreement for most of these transitions, with our theoretical values agreeing slightly more closely with the solar than with the laboratory measurements. A detailed analysis of the small number of transitions for which the agreement between theory and experiment is not as good shows that such disagreements largely arise from severe cancellation due to CI mixing.

Deb, N. C.; Hibbert, A.

2014-01-01

6

Lumber Values from Computerized Simulation of Hardwood Log Sawing.  

National Technical Information Service (NTIS)

Computer simulation sawing programs were used to study the sawing of mathematical models of hardwood logs by the live sawing and three 4-sided sawing methods. One of the 4-sided methods simulated 'grade sawing' by sawing wach successive board from the log...

D. B. Richards E. H. Bulgrin H. Hallock W. K. Adkins

1980-01-01

7

On the hydrophobicity of peptides: Comparing empirical predictions of peptide log P values.  

PubMed

Peptides are of great therapeutic potential as vaccines and drugs. Knowledge of physicochemical descriptors, including the partition coefficient logP, is useful for the development of predictive Quantitative Structure-Activity Relationships (QSARs). We have investigated the accuracy of available programs for the prediction of logP values for peptides with known experimental values obtained from the literature. Eight prediction programs were tested, of which seven programs were fragment-based methods: XLogP, LogKow, PLogP, ACDLogP, AlogP, Interactive Analysis's LogP and MlogP; and one program used a whole molecule approach: QikProp. The predictive accuracy of the programs was assessed using r(2) values, with ALogP being the most effective (r( 2) = 0.822) and MLogP the least (r(2) = 0.090). We also examined three distinct types of peptide structure: blocked, unblocked, and cyclic. For each study (all peptides, blocked, unblocked and cyclic peptides) the performance of programs rated from best to worse is as follows: all peptides - ALogP, QikProp, PLogP, XLogP, IALogP, LogKow, ACDLogP, and MlogP; blocked peptides - PLogP, XLogP, ACDLogP, IALogP, LogKow, QikProp, ALogP, and MLogP; unblocked peptides - QikProp, IALogP, ALogP, ACDLogP, MLogP, XLogP, LogKow and PLogP; cyclic peptides - LogKow, ALogP, XLogP, MLogP, QikProp, ACDLogP, IALogP. In summary, all programs gave better predictions for blocked peptides, while, in general, logP values for cyclic peptides were under-predicted and those of unblocked peptides were over-predicted. PMID:17597897

Thompson, Sarah J; Hattotuwagama, Channa K; Holliday, John D; Flower, Darren R

2006-01-01

8

INCREASING THE ACCURACY OF COMPUTER CALCULATED LOG P (OCT/WATER) VALUES  

EPA Science Inventory

Like many "expert systems," the CLOGP program incorporates a set of empirically derived rules which are supported by accepted theoretical concepts but which cannot be derived directly from these concepts. igher log P values are expected whenever a larger effective solute cavity i...

9

Expression of KOC, S100P, mesothelin and MUC1 in pancreatico-biliary adenocarcinomas: development and utility of a potential diagnostic immunohistochemistry panel  

PubMed Central

Background Pancreatico-biliary adenocarcinomas (PBA) have a poor prognosis. Diagnosis is usually achieved by imaging and/or endoscopy with confirmatory cytology. Cytological interpretation can be difficult especially in the setting of chronic pancreatitis/cholangitis. Immunohistochemistry (IHC) biomarkers could act as an adjunct to cytology to improve the diagnosis. Thus, we performed a meta-analysis and selected KOC, S100P, mesothelin and MUC1 for further validation in PBA resection specimens. Methods Tissue microarrays containing tumour and normal cores in a ratio of 3:2, from 99 surgically resected PBA patients, were used for IHC. IHC was performed on an automated platform using antibodies against KOC, S100P, mesothelin and MUC1. Tissue cores were scored for staining intensity and proportion of tissue stained using a Histoscore method (range, 0–300). Sensitivity and specificity for individual biomarkers, as well as biomarker panels, were determined with different cut-offs for positivity and compared by summary receiver operating characteristic (ROC) curve. Results The expression of all four biomarkers was high in PBA versus normal ducts, with a mean Histoscore of 150 vs. 0.4 for KOC, 165 vs. 0.3 for S100P, 115 vs. 0.5 for mesothelin and 200 vs. 14 for MUC1 (p?values: KOC 84%/100%; S100P 83%/100%; mesothelin 88%/92%; and MUC1 89%/63%. Analysis of a panel of KOC, S100P and mesothelin achieved 100% sensitivity and 99% specificity if at least 2 biomarkers were positive for 10% cut-off; and 100% sensitivity and specificity for 20% cut-off. Conclusion A biomarker panel of KOC, S100P and mesothelin with at least 2 biomarkers positive was found to be an optimum panel with both 10% and 20% cut-offs in resection specimens from patients with PBA.

2014-01-01

10

Lumber value differences from reduced CT spatial resolution and simulated log sawing  

Microsoft Academic Search

In the past few years, computed tomography (CT) scanning technology has been applied to the detection of internal defects in hardwood logs for the purpose of obtaining a priori information that can be used to arrive at better log sawing decisions. Because sawyers currently cannot even see the inside of a log until the log faces are revealed by sawing,

Suraphan Thawornwong; Luis G. Occena; Daniel L. Schmoldt

2003-01-01

11

Technology Transfer via Value-Added Log Processing. Final Report, September 1994-December 1995.  

National Technical Information Service (NTIS)

There are roughly 500,000 electric logs (ES-logs) for wells in the U.S. Many of these are in cased wells, precluding the possibility of further resistivity logging. Software has been developed to predict an earth model directly for the individual curves i...

W. W. Whitman

1995-01-01

12

Global QSAR modeling of logP values of phenethylamines acting as adrenergic alpha-1 receptor agonists.  

PubMed

Global QSAR models predict biological response of molecular structures which are generic in particular class. A global QSAR dataset admits structural features derived from larger chemical space, intricate to model but more applicable in medicinal chemistry. The present work is global in either sense of structural diversity in QSAR dataset or large number of descriptor input. Forty phenethylamine structure derivatives were selected from a large pool (904) of similar phenethylamines available in Pubchem database. LogP values of selected candidates were collected from physical properties database (PHYSPROP) determined in identical set of conditions. Attempts to model logP value have produced significant QSAR models. MLR aided linear one-variable and two-variable QSAR models with their respective R(2) (0.866, 0.937), R(2)A (0.862, 0.932), F-stat (181.936, 199.812) and Standard Error (0.365, 0.255) are statistically fit and found predictive after internal validation and external validation. The descriptors chosen after improvisation and optimization reveal mechanistic part of work in terms of Verhaar model of Fish base-line toxicity from MLOGP, i.e. (BLTF96) and 3D-MoRSE -signal 15 /unweighted molecular descriptor calculated by summing atom weights viewed by a different angular scattering function (Mor15u) are crucial in regulation of logP values of phenethylamines. PMID:23740397

Yadav, Mukesh; Joshi, Shobha; Nayarisseri, Anuraj; Jain, Anuja; Hussain, Aabid; Dubey, Tushar

2013-06-01

13

ELOG Operational Logs and Knowledge Base Engine Effectiveness and Added Value of Systematic Operational Logging During Development and Integration of Complex Data Ground System  

Microsoft Academic Search

During integration and launch preparation activity several and various are the testing activities performed at Operation Control Centres such as Software or System Acceptance testing, System Validation Test (SVTs), Ground Segment Interfaces Validation Test , Mission Readiness Tests (MRTs), Simulations Campaign etc. Huge amount of logs are produced during these demanding testing activities: problem reports, issues requiring actions or coordination,

G. di Girolamo

2003-01-01

14

Retinoic acid directly stimulates osteoclastic bone resorption and gene expression of cathepsin K/OC-2.  

PubMed Central

Vitamin A metabolites such as all-trans-retinoic acid (all-trans-RA) affect several steps of metabolic processes in vertebrates. In the last few years, several studies have shown the effect of RA on bone formation and metabolism. However, mechanisms of its action still remain unclear, especially with respect to the regulation of bone cells. Therefore, this study was carried out to clarify how RA regulates the activity of osteoclasts. Using a pit assay involving unfractionated bone cells, including osteoclasts obtained from rabbits, we found that RA stimulated an increase in the bone-resorbing activity in a dose- and time-dependent manner. Furthermore, this effect occurred more rapidly than that of treatments with 1 alpha,25-dihydroxyvitamin D3. However, this effect of RA may be partly related to cross-talk between osteoclasts and other types of cells. Therefore we studied the effect of RA on isolated osteoclasts. We found that all-trans-RA regulates the gene expression of cathepsin K/OC-2, a dominant cysteine proteinase, at the transcriptional level in mature osteoclasts isolated from rabbits. Moreover, retinoic acid-receptor alpha mRNA and retinoid X-receptor beta mRNA were expressed in these mature osteoclasts. Our results indicate that osteoclasts are target cells for RA and that RA might regulate a part of bone formation and metabolism through osteoclasts. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Saneshige, S; Mano, H; Tezuka, K; Kakudo, S; Mori, Y; Honda, Y; Itabashi, A; Yamada, T; Miyata, K; Hakeda, Y

1995-01-01

15

Deriving Criteria-supporting Benchmark Values from Empirical Response Relationships: Comparison of Statistical Techniques and Effect of Log-transforming the Nutrient Variable  

EPA Science Inventory

In analyses supporting the development of numeric nutrient criteria, multiple statistical techniques can be used to extract critical values from stressor response relationships. However there is little guidance for choosing among techniques, and the extent to which log-transfor...

16

VARIATION OF KOC IN SURFACE SEDIMENTS FROM NARRAGANSETT BAY AND LONG ISLAND SOUND: ANALYSIS OF THE ROLE OF OTHER PARTICULATE CHARACTERISTICS  

EPA Science Inventory

In the first part of this investigation, we examined whether differences in the Kocs of three nonpolar organic chemicals (Lindane, fluoranthene, tetrachlorinated biphenyl (PCB)) from five sites along the New England coast were statistically significant. Although no statistical di...

17

Interaction of povidone with aromatic compounds. VI: Use of partition coefficients (log Kd) to correlate with log P values and apparent Kd values to express the binding as a function of pH and pKa.  

PubMed

The binding of neutral aromatic compounds onto povidone was studied. It was found that the binding depends on the lipophilic character of the compound and that a linear free relationship exists between the logarithm of the partition coefficients of the macromolecular pseudo-two-phase-aqueous phase, and the log partition coefficient of n-octanol-water (log P). For the ionized ligand molecules it was shown that the binding could be expressed in terms of the acid dissociation constant of the solute, Ka, and in terms of two partition coefficients, K1 = HAPVP/HAwater and K2 = APVP/Awater for the nondissociated and dissociated forms, respectively, resulting in the apparent partition coefficient Kdapp = (HAPVP + APVP)/(HAwater + Awater). An expression was derived, permitting one to determine K1 and K2 from measurable quantities. The apparent partition coefficients (Kdapp) were independent of both drug and povidone concentrations, indicating that the modes of povidone compound interactions were essentially invariant over the ranges of systematic variables studied. The method provides a simple means of evaluating ligand-macromolecule interaction as a function of pH of the solvent and pKa of the ligand. PMID:3430347

Plaizier-Vercammen, J A

1987-10-01

18

Improved log(gf) Values for Lines of Ni I and New Nickel Abundances in the Sun and the Metal-Poor Star HD 84937  

NASA Astrophysics Data System (ADS)

New atomic transition probability measurements for 371 lines of Ni I in the UV through near IR are reported. These results are used to determine the Ni abundance of the Sun and a very metal-poor main-sequence turnoff dwarf star over a range of wavelength and E. P. values to search for non-LTE effects. For reasons only partially understood, strong lines of Ni I are unusually prone to optical depth errors in emission studies on laboratory sources. Branching fractions from data recorded using a Fourier transform spectrometer (FTS) and a 3 m echelle spectrometer are combined with published radiative lifetimes from laser induced fluorescence measurements to determine these new transition probabilities. The large echelle spectrometer provides essential UV sensitivity, spectral resolution, and especially freedom from multiplex noise that is needed to eliminate optical depth errors. There is quite good agreement with earlier, but less extensive, sets of measurements by Blackwell et al. (MNRAS 1989, 236, 235) and Wickliffe & Lawler (ApJS 1997 110, 1163). The new Ni I data are applied to high resolution visible and UV spectra of the Sun and HD 84937 to derive new, more accurate nickel abundances. In the Sun we find log(eps(Ni I)) = 6.28 (sigma = 0.06, 75 lines) and in HD 84937 we find we find log(eps(Ni I)) = 3.89 (sigma = 0.09, 77 lines), yielding [Ni/Fe] = -0.08 from log(eps(Fe)) = 7.52 in the Sun and log(eps(Fe)) = 5.19 in HD 84937. The Saha balance of Ni in HD 84937 is confirmed using 8 lines of Ni II, although these UV ion lines are somewhat saturated. This work is supported by NASA grant NNX10AN93G (JEL) and NSF grants AST-0908978 and AST-1211585 (CS).

Lawler, James E.; Wood, M. P.; Sneden, C.; Cowan, J. J.

2014-01-01

19

Relation between the fractal distribution of elastic parameters in the earth crust and the Gutenberg-Richter b-value of earthquakes: A method to estimate b-values from sonic well logs  

NASA Astrophysics Data System (ADS)

Sonic well logs provide in situ measurements of physical properties and their fluctuations in the earth crust. The analysis of log data from various sites suggests that elastic parameters exhibit a heterogeneous distribution characterized by broad band fractal scaling. However, the significance of this finding for the distribution of stress inside the earth crust has not yet been analyzed. Independently from the works above, it was shown that power law scaling of the number of earthquake with magnitude, expressed in the Gutenberg-Richter relation, can be explained by fractal distributed stress. However, a direct reason for the fractal distribution of stress is still lacking. In this paper we establish relations between the fractal distribution of elastic parameters, stress field variations and the Gutenberg-Richter b-value of earthquakes. We extract information about elastic parameter distribution from sonic logs to create an elastically heterogeneous 3D random medium with a fractal spatial correlation function. Using the finite element program Abaqus we apply an externally homogeneous stress field and compute the resulting stress distribution inside the elastically heterogeneous medium. We use geomechanical considerations to determine the distribution of Coulomb Failure Stress (CFS) as a measure of the vicinity to failure. The resulting CFS distribution is highly heterogeneous, of fractal nature and strongly related to the initially assigned elastic parameters. We assume that rupturing, once it is initiated (e.g. by an increase of stress or pore pressure), takes place along isovolumes of CFS. We determine the number size distribution of isovolumes and compute their characteristic area. The distribution of characteristic fault planes and correspondingly magnitudes exhibits power law scaling according to the Gutenberg Richter law. We find that elastic heterogeneity leads to b-values in the range of 1value is reflecting the level of elastic heterogeneity at a considered region. The degree of elastic heterogeneity is a site specific physical parameter, which could explain the variability of the b-value from one region to another. Since the b-value is a direct result of elastic parameter distribution, our method allows to estimate b-values from sonic well logs. The application of our method to well log data measured along the Continental Deep Drilling Site (KTB, Germany) main hole results in a realistic b-value of b=1.4.

Langenbruch, C.; Shapiro, S. A.

2012-12-01

20

Realtime logging  

SciTech Connect

This article reports that measurement-while-drilling (MWD) logging services have become an important new source of drilling and geological information on wildcats and some development wells. Sensors located within the bottomhole assembly, barely a few feet above the bit, make measurements on the formation, the borehole and the drill string itself. The MWD measurements are electronically processed and stored in the logging tool downhole. Simple MWD logging systems must wait until after tripping out of the hole for the MWD data to be downloaded from the logging tool to a surface computer in order for logs to be produced. This method is acceptable for some formation evaluation problems. But when well control, directional or completion decisions must be made, the benefit of MWD logging data is obtained only if the downhole measurements are available to the engineer in realtime.

Whittaker, A.; Kashuba, M.J.

1987-01-01

21

Rare variant collapsing in conjunction with mean log p-value and gradient boosting approaches applied to Genetic Analysis Workshop 17 data  

PubMed Central

In addition to methods that can identify common variants associated with susceptibility to common diseases, there has been increasing interest in approaches that can identify rare genetic variants. We use the simulated data provided to the participants of Genetic Analysis Workshop 17 (GAW17) to identify both rare and common single-nucleotide polymorphisms and pathways associated with disease status. We apply a rare variant collapsing approach and the usual association tests for common variants to identify candidates for further analysis using pathway-based and tree-based ensemble approaches. We use the mean log p-value approach to identify a top set of pathways and compare it to those used in simulation of GAW17 dataset. We conclude that the mean log p-value approach is able to identify those pathways in the top list and also related pathways. We also use the stochastic gradient boosting approach for the selected subset of single-nucleotide polymorphisms. When compared the result of this tree-based method with the list of single-nucleotide polymorphisms used in dataset simulation, in addition to correct SNPs we observe number of false positives.

2011-01-01

22

Transaction Logging.  

ERIC Educational Resources Information Center

Discusses the use of transaction logging in Okapi-related projects to allow search algorithms and user interfaces to be investigated, evaluated, and compared. A series of examples is presented, illustrating logging software for character-based and graphical user interface systems, and demonstrating the usefulness of relational database management…

Jones, S.; And Others

1997-01-01

23

Kinematics of the Local Universe. V. The value of H_0_ from the Tully-Fisher B and logD_25_ relations for field galaxies.  

NASA Astrophysics Data System (ADS)

We have studied the value of the Hubble constant using the KLUN (Kinematics of the Local Universe) sample of 5171 spiral galaxies having isophotal diameters D_25_ (and partially B-magnitudes), Hi line widths, and radial velocities. The sample is diameter-limited, complete down to D_25_=1.6arcmin. As in the first similar study, where a much smaller magnitude-limited sample was used (Bottinelli et al. 1986), we pay special attention to the problem of Malmquist bias when photometric distances are derived by the Tully-Fisher diameter or magnitude relations. The bias is revealed and overcome by a more advanced version of the method of normalized distances, now taking into account, in addition to diameter and magnitude limits, also Hubble type effect, inclination effect, and variable galactic extinction. Calibration of the Tully-Fisher relations is primarily performed using a sample of 15 galaxies with available Cepheid distances, mostly from the HST programmes. This sample does not show significant trends with distance and is concluded to be closely distance-limited. Analysis of the logH_0_ vs. d_normalized_ diagrams allows us to identify the "unbiased plateaus" for both the diameter and magnitude TF distances. A useful tool here introduced is the theoretical expectation of the bias in cumulative <logH_0_> as a function of the fraction of the sample accepted for the plateau. An iterative approach is utilized for determining the TF relations, the plateau, and the value of H_0_ therefrom. Using the Peebles linear velocity field model with Virgo and our infall velocities equal to 980km/s and 150km/s, respectively, we derived the following values of H_0_: H_0_=53.4+/-5.0km/s/Mpc (N_gal_=415) from the magnitude relation, and H_0_=56.7+/-4.9km/s/Mpc (N_gal_=403) from the diameter relation. The given 1?-errors refer to the statistical scatter around the adopted calibration, and the dispersion of the calibrator sample itself. These H_0_ values are not sensitive to reasonable changes in the kinematical parameters of the velocity field model, up to the extreme ones found in literature. This insensitivity is also expected from our numerical experiments. In the radial velocity space, the unbiased plateau extends up to about 6000km/s and the value of H_0_ is in good agreement with the SNIa results by Sandage et al. (1996, in press) which extend to still larger velocities. At present, the supernovae method and the KLUN TF-sample, both calibrated with Cepheid distances, provide complementary approaches to H_0_ in different, though overlapping, redshift ranges. As an additional result, the normalized distance method provides a natural way to estimate the Local Group infall velocity by minimizing the logH_0_ dispersion in the unbiased plateau. Using the diameter and the magnitude TF relations respectively, we obtained, as preliminary results, the following values: v_0_=225+/-45km/s, and v_0_=185+/-40km/s. These values are compatible with our standard value within 2 ? and agree particulary well with Sandage's preferred value v_0_=220km/s.

Theureau, G.; Hanski, M.; Ekholm, T.; Bottinelli, L.; Gouguenheim, L.; Paturel, G.; Teerikorpi, P.

1997-06-01

24

Mud logging handbook  

SciTech Connect

The author provides a review of all available types and levels of well site services which can be performed in the mud logging unit. For each service, an explanation is given of how, how well, and when the gathered data may be applied. The value of mud logging services and data are assessed on the basis of their usefulness, quality, and timeliness in the chronology of drilling optimization and formation evaluation.

Whittaker, A.

1990-01-01

25

Log Tape  

NSDL National Science Digital Library

In this activity students construct Log Tapes calibrated in base-ten exponents, then use them to derive relationships between base-ten logs (exponents) and antilogs (ordinary numbers).  This is activity B1 in the "Far Out Math" educator's guide. Lessons in the guide include activities in which students measure,compare quantities as orders of magnitude, become familiar with scientific notation, and develop an understanding of exponents and logarithms using examples from NASA's GLAST mission. These are skills needed to understand the very large and very small quantities characteristic of astronomical observations. Note: In 2008, GLAST was renamed Fermi, for the physicist Enrico Fermi.

26

Well logging II - Electric and acoustic logging  

SciTech Connect

This book covers electric logging, log interpretation and electromagnetic principles. The book also discuss principles of acoustic logging and details of acoustic log interpretation, including effects of amplitude attenuation devices and investigation of interval transit times.

Jorden, J.R.; Campbell, F.L.

1986-01-01

27

Thermal conditions of the central Sinai Microplate inferred from new surface heat-flow values and continuous borehole temperature logging in central and southern Israel  

NASA Astrophysics Data System (ADS)

This paper reports ten new surface heat-flow density (qs) values for central and southern Israel (central Sinai Microplate), whose crystalline crust and lithosphere formed as part of the Neoproterozoic Arabian-Nubian Shield. Heat flow was calculated in Mesozoic sediments using the classical approach of heat-flow determination by implementing in the analysis high-precision continuous temperature logs obtained in air- and/or water-filled boreholes. Thermal conductivity (TC) measured for a large suite of rock samples of lithotypes making up the sequence was assigned to temperature gradients in intervals for which the lithology was known. The heat-flow values obtained for different depth intervals in a borehole as well as the average values for the individual borehole locations cover a narrow range, attesting heat-conduction conditions. A steady-state thermal model along an E–W crustal cross section through the area shows that the observed systematic spatial distribution of the qs values, which range between 50 and 62 mW m?2, can primarily be explained by variations in the thickness of the upper crust and in the ratio between sedimentary and crystalline rocks therein. Given the time lapse of thermal heat transfer through the lithosphere, the qs data monitor the crustal thermal conditions prior to rift- and plume-related lithospheric thermal perturbations that have started in the larger area ca. 30 Ma ago. Observed and modeled qs display the best fit for a pre-Oligocene lithosphere–asthenosphere boundary (LAB) at ˜150 km, which would be at the upper end of LAB depths determined from stable areas of the Arabian Shield (150–120 km) not affected by the young, deep-seated thermal processes that have caused a further uprise of the LAB. Our data imply or predict that the surface heat flow of the Sinai Microplate generally tends to increase along N–S and W–E traverses, from ˜45–50 mW m?2 to ˜55–60 mW m?2. Surface heat flows on the order of 55–60 mW m?2 may be common in the northern Arabian Shield, where it exhibits typical lithosphere structure and composition and is unaffected by young heating processes, compared to values of ?45 mW m?2 recently determined in the southern Arabian Plate for the Arabian Platform.

Schütz, F.; Förster, H.-J.; Förster, A.

2014-05-01

28

Log Ruler  

NSDL National Science Digital Library

In this activity students construct Log Rulers, finely calibrated in base-10 exponents and numbers (logs and antilogs). They practice reading these scales as accurately as possible, listing all certain figures plus one uncertain figure.  This is activity D1 in the "Far Out Math" educator's guide. Lessons in the guide include activities in which students measure,compare quantities as orders of magnitude, become familiar with scientific notation, and develop an understanding of exponents and logarithms using examples from NASA's GLAST mission. These are skills needed to understand the very large and very small quantities characteristic of astronomical observations. Note: In 2008, GLAST was renamed Fermi, for the physicist Enrico Fermi.

29

Log Algebra  

NSDL National Science Digital Library

In this activity, students solve exponential equations where the unknown is contained in the exponent. Students learn that taking base-10 or base-2 logs pulls down the exponent, allowing the unknown to be isolated and solved.  This activity is activity C3 in the "Far Out Math" educator's guide. Lessons in the guide include activities in which students measure, compare quantities as orders of magnitude, become familiar with scientific notation, and develop an understanding of exponents and logarithms using examples from NASA's GLAST mission. These are skills needed to understand the very large and very small quantities characteristic of astronomical observations. Note: In 2008, GLAST was renamed Fermi, for the physicist Enrico Fermi.

30

CRYPTOSPORIDIUM LOG INACTIVATION CALCULATION METHODS  

EPA Science Inventory

Appendix O of the Surface Water Treatment Rule (SWTR) Guidance Manual introduces the CeffT10 (i.e., reaction zone outlet C value and T10 time) method for calculating ozone CT value and Giardia and virus log inactivation. The LT2ESWTR Pre-proposal Draft Regulatory Language for St...

31

The Meaning of Logs  

Microsoft Academic Search

While logging events is becoming increasingly common in computing, in communication and in collaborative work, log systems need to satisfy increasingly challenging (if not conflicting) requirements. Despite the growing pervasiveness of log systems, to date there is no high-level framework which allows one to model a log system and to check whether it meets the requirements it should satisfy. In

Sandro Etalle; Fabio Massacci; Artsiom Yautsiukhin

2007-01-01

32

Values.  

ERIC Educational Resources Information Center

GRADES OR AGES: Grades 1-12. SUBJECT MATTER: Values. ORGANIZATION AND PHYSICAL APPEARANCE: The guide is intended to define the development of the valuing process and contains ideas for classroom teachers. It is not a conventional curriculum guide but is recommended for use with the guide on drug education (SP 007 318). It contains the following…

Chapel Hill City Schools, NC.

33

Petrographic image logging system  

Microsoft Academic Search

The Petrographic Image Logging System (PILS) is a logging system data base for Macintosh computers that allows the merging of traditional wire-line, core, and mud log data with petrographic images. The system is flexible; it allows the user to record, manipulate, and display almost any type of character, graphic, and image information. Character and graphic data are linked and entry

C. J. Payne; M. R. Ulrich; G. B. Maxwell; J. P. Adams

1991-01-01

34

Public Report on Health: Development of a Nutritive Value Calculator for Indian Foods and Analysis of Food Logs and Nutrient Intake in six States.  

PubMed

The Public Report on Health (PRoH) was initiated in 2005 to understand public health issues for people from diverse backgrounds living in different region specific contexts. States were selected purposively to capture a diversity of situations from better-performing states and not-so-well performing states. Based on these considerations, six states - the better-performing states of Tamil Nadu (TN), Maharashtra (MH) and Himachal Pradesh (HP) and the not-so-well performing states of Madhya Pradesh (MP), Uttar Pradesh (UP) and Orissa (OR) - were selected. This is a report of a study using food diaries to assess food intakes in sample households from six states of India. Method: Food diaries were maintained and all the raw food items that went into making the food in the household was measured using a measuring cup that converted volumes into dry weights for each item. The proportion consumed by individual adults was recorded. A nutrient calculator that computed the total nutrient in the food items consumed, using the 'Nutritive Value of Indian Foods by Gopalan et al., was developed to analyze the data and this is now been made available as freeware (http://bit.ly/ncalculator). The total nutrients consumed by the adults, men and women was calculated. Results: Identifying details having been removed, the raw data is available, open access on the internet http://bit.ly/foodlogxls.The energy consumption in our study was 2379 kcal per capita per day. According to the Summary Report World Agriculture the per capita food consumption in 1997-99 was 2803 which is higher than that in the best state in India. The consumption for developing countries a decade ago was 2681 and in Sub-Saharan Africa it was 2195. Our data is compatible in 2005 with the South Asia consumption of 2403 Kcal per capita per day in 1997-99. For comparison, in industrialized countries it was 3380. In Tamil Nadu it was a mere 1817 kcal. Discussion: The nutrient consumption in this study suggests that food security in the villages studied is far from achieved. It is hoped that the new Food Security Ordinance will make a dent in the situation. The calculator for computing nutrients of foods consumed which we developed based on the ICMR defined nutrient values for Indian foods has been made available as freeware on the internet. This is with the hope that more such studies can be carried out at the household level. PMID:24995224

Sathyamala, C; Kurian, Nj; DE, Anuradha; Saxena, Kb; Priya, Ritu; Baru, Rama; Srivastava, Ravi; Mittal, Onkar; Noronha, Claire; Samson, Meera; Khalsa, Sneh; Puliyel, Ashish; Puliyel, Jacob

2014-05-01

35

Public Report on Health: Development of a Nutritive Value Calculator for Indian Foods and Analysis of Food Logs and Nutrient Intake in six States  

PubMed Central

The Public Report on Health (PRoH) was initiated in 2005 to understand public health issues for people from diverse backgrounds living in different region specific contexts. States were selected purposively to capture a diversity of situations from better-performing states and not-so-well performing states. Based on these considerations, six states – the better-performing states of Tamil Nadu (TN), Maharashtra (MH) and Himachal Pradesh (HP) and the not-so-well performing states of Madhya Pradesh (MP), Uttar Pradesh (UP) and Orissa (OR) – were selected. This is a report of a study using food diaries to assess food intakes in sample households from six states of India. Method: Food diaries were maintained and all the raw food items that went into making the food in the household was measured using a measuring cup that converted volumes into dry weights for each item. The proportion consumed by individual adults was recorded. A nutrient calculator that computed the total nutrient in the food items consumed, using the ‘Nutritive Value of Indian Foods by Gopalan et al., was developed to analyze the data and this is now been made available as freeware (http://bit.ly/ncalculator). The total nutrients consumed by the adults, men and women was calculated. Results: Identifying details having been removed, the raw data is available, open access on the internet http://bit.ly/foodlogxls.The energy consumption in our study was 2379 kcal per capita per day. According to the Summary Report World Agriculture the per capita food consumption in 1997-99 was 2803 which is higher than that in the best state in India. The consumption for developing countries a decade ago was 2681 and in Sub-Saharan Africa it was 2195. Our data is compatible in 2005 with the South Asia consumption of 2403 Kcal per capita per day in 1997-99. For comparison, in industrialized countries it was 3380. In Tamil Nadu it was a mere 1817 kcal. Discussion: The nutrient consumption in this study suggests that food security in the villages studied is far from achieved. It is hoped that the new Food Security Ordinance will make a dent in the situation. The calculator for computing nutrients of foods consumed which we developed based on the ICMR defined nutrient values for Indian foods has been made available as freeware on the internet. This is with the hope that more such studies can be carried out at the household level.

Sathyamala, C; Kurian, NJ; DE, Anuradha; Saxena, KB; Priya, Ritu; Baru, Rama; Srivastava, Ravi; Mittal, Onkar; Noronha, Claire; Samson, Meera; Khalsa, Sneh; Puliyel, Ashish

2014-01-01

36

Log N-log S in inconclusive  

NASA Technical Reports Server (NTRS)

The log N-log S data acquired by the Pioneer Venus Orbiter Gamma Burst Detector (PVO) are presented and compared to similar data from the Soviet KONUS experiment. Although the PVO data are consistent with and suggestive of a -3/2 power law distribution, the results are not adequate at this state of observations to differentiate between a -3/2 and a -1 power law slope.

Klebesadel, R. W.; Fenimore, E. E.; Laros, J.

1983-01-01

37

LogScope  

NASA Technical Reports Server (NTRS)

LogScope is a software package for analyzing log files. The intended use is for offline post-processing of such logs, after the execution of the system under test. LogScope can, however, in principle, also be used to monitor systems online during their execution. Logs are checked against requirements formulated as monitors expressed in a rule-based specification language. This language has similarities to a state machine language, but is more expressive, for example, in its handling of data parameters. The specification language is user friendly, simple, and yet expressive enough for many practical scenarios. The LogScope software was initially developed to specifically assist in testing JPL s Mars Science Laboratory (MSL) flight software, but it is very generic in nature and can be applied to any application that produces some form of logging information (which almost any software does).

Havelund, Klaus; Smith, Margaret H.; Barringer, Howard; Groce, Alex

2012-01-01

38

Methods of generating synthetic acoustic logs from resistivity logs for gas-hydrate-bearing sediments  

USGS Publications Warehouse

Methods of predicting acoustic logs from resistivity logs for hydrate-bearing sediments are presented. Modified time average equations derived from the weighted equation provide a means of relating the velocity of the sediment to the resistivity of the sediment. These methods can be used to transform resistivity logs into acoustic logs with or without using the gas hydrate concentration in the pore space. All the parameters except the unconsolidation constants, necessary for the prediction of acoustic log from resistivity log, can be estimated from a cross plot of resistivity versus porosity values. Unconsolidation constants in equations may be assumed without rendering significant errors in the prediction. These methods were applied to the acoustic and resistivity logs acquired at the Mallik 2L-38 gas hydrate research well drilled at the Mackenzie Delta, northern Canada. The results indicate that the proposed method is simple and accurate.

Lee, Myung W.

1999-01-01

39

Ulysses log 1992  

NASA Technical Reports Server (NTRS)

The Ulysses Log tells the story of some intriguing problems that we (=The Spacecraft Team) have encountered. Ulysses was launched on 6 Oct. 1990, and it made the fastest trip to Jupiter (8 Feb. 1992). It is presently going out of the ecliptic. This paper presents log entries from the following areas: (1) ingenious maneuvers; (2) telecommunication problems; and (3) surprises.

Perez, Raul Garcia

1993-01-01

40

6. Log calving barn. Interior view showing log postandbeam support ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. Log calving barn. Interior view showing log post-and-beam support system and animal stalls. - William & Lucina Bowe Ranch, Log Calving Barn, 230 feet south-southwest of House, Melrose, Silver Bow County, MT

41

Interactive Reflective Logs  

NSDL National Science Digital Library

The authors created an interactive reflective log (IRL) to provide teachers with an opportunity to use a journal approach to record, evaluate, and communicate student understanding of science concepts. Unlike a traditional journal, the IRL incorporates pr

Deaton, Benjamin E.; Deaton, Cynthia M.; Leland, Katina

2010-11-01

42

4. Log chicken house (far left foreground), log bunkhouse (far ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Log chicken house (far left foreground), log bunkhouse (far left background), one-room log cabin (left of center background), log root cellar (center), post-and-beam center in foreground, and blacksmith shop (far right foreground). View to southeast. - William & Lucina Bowe Ranch, County Road 44, 0.1 mile northeast of Big Hole River Bridge, Melrose, Silver Bow County, MT

43

Shale compaction and sonic logs  

US Patent & Trademark Office Database

A method of calculating a theoretical sonic log from an ideal sonic log and resistivity data. The method involves calculating the ideal sonic log assuming a shale sediment and using available data from a well or the surrounding region. Resistivity data is used to correct the ideal sonic log for departures from the shale sediment assumption. The calculated theoretical sonic log may then be used to calibrate an experimental log and to replace low confidence segments of the experimental log. The method allows useful information to be derived for wells previously considered uneconomical.

2002-06-25

44

Interactive Reflective Logs  

ERIC Educational Resources Information Center

The authors created an interactive reflective log (IRL) to provide teachers with an opportunity to use a journal approach to record, evaluate, and communicate student understanding of science concepts. Unlike a traditional journal, the IRL incorporates prompts to encourage students to discuss their understanding of science content and science…

Deaton, Cynthia Minchew; Deaton, Benjamin E.; Leland, Katina

2010-01-01

45

Logging on to Learn  

ERIC Educational Resources Information Center

A classroom lecture at Capistrano Connections Academy in Southern California involves booting up the home computer, logging on to a Web site, and observing a teacher conducting a PowerPoint presentation of that day's lesson entirely online. Through microphone headsets, students can watch on their home computers, respond to the teacher's questions,…

Butler, Kevin

2010-01-01

46

3D GPR Imaging of Wooden Logs  

NASA Astrophysics Data System (ADS)

There has been a lack of an effective NDE technique to locate internal defects within wooden logs. The few available elastic wave propagation based techniques are limited to predicting E values. Other techniques such as X-rays have not been very successful in detecting internal defects in logs. If defects such as embedded metals could be identified before the sawing process, the saw mills could significantly increase their production by reducing the probability of damage to the saw blade and the associated downtime and the repair cost. Also, if the internal defects such as knots and decayed areas could be identified in logs, the sawing blade can be oriented to exclude the defective portion and optimize the volume of high valued lumber that can be obtained from the logs. In this research, GPR has been successfully used to locate internal defects (knots, decays and embedded metals) within the logs. This paper discusses GPR imaging and mapping of the internal defects using both 2D and 3D interpretation methodology. Metal pieces were inserted in a log and the reflection patterns from these metals were interpreted from the radargrams acquired using 900 MHz antenna. Also, GPR was able to accurately identify the location of knots and decays. Scans from several orientations of the log were collected to generate 3D cylindrical volume. The actual location of the defects showed good correlation with the interpreted defects in the 3D volume. The time/depth slices from 3D cylindrical volume data were useful in understanding the extent of defects inside the log.

Halabe, Udaya B.; Pyakurel, Sandeep

2007-03-01

47

A lithological segmentation from sonic logs using wavelet transform  

NASA Astrophysics Data System (ADS)

The analysis of well logs allows to extract worthy information about the sub-surface. Here, the logs are used to perform a lithological segmentation using the wavelet transform. The basic idea consists of estimating the local regularity strength, measured by the Hölder exponent (H), using the wavelet transform. The change in the H value allows to identify the lithological discontinuities within the strata crossed by the well. This method is first implemented on synthetic logs, then applied to real sonic logs data recorded in Algerian boreholes. The results reveal that efficiency of the proposed technique in the lithological segmentation. Keywords: well log, wavelet transform, Hölder exponent, regularity

Gaci, S.; Zaourar, N.; Ouadfeul, S.

2012-04-01

48

Well logging for the nontechnical person  

SciTech Connect

The contents of this book are: Introduction to logging; Reading logs; Formation parameters; Mud logging; Resistivity measurements; Porosity measurements; Putting it all together; detailed interpretations; Computer-generated logs; Specialty logs.

Johnson, D.E.; Pile, K.E.

1988-01-01

49

2. Onroom log cabin (right), log root cellar (center), tworoom ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. On-room log cabin (right), log root cellar (center), two-room log cabin (left), and post-and-beam garage (background). View to southwest. - William & Lucina Bowe Ranch, County Road 44, 0.1 mile northeast of Big Hole River Bridge, Melrose, Silver Bow County, MT

50

12. Upstream view showing thelower log pond log chute in ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. Upstream view showing thelower log pond log chute in the main channel of the Hudson River. The log chute in the dam can be seen in the background. Facing southwest. - Glens Falls Dam, 100' to 450' West of U.S. Route 9 Bridge Spanning Hudson River, Glens Falls, Warren County, NY

51

Review of Log Sort Yards.  

National Technical Information Service (NTIS)

This report provides a general overview of current log sort yard operations in the United States, including an extensive literature review and information collected during on-site visits to several operations throughout the nation. Log sort yards provide ...

J. R. Dramm G. L. Jackson J. Wong

2002-01-01

52

Log Monitors in BSD UNIX  

Microsoft Academic Search

A log monitor is a process, or daemon, which monitors log messages produced by a computer system and the programs which run on it. A properly designed log monitor can recognize unusual activity (or inactivity), alert an administrator to problems, gather statistics about system activity, and\\/or take automatic action to contain a threat. It can even \\

Brett Glass

2002-01-01

53

Fractional Indices of Log del Pezzo Surfaces  

NASA Astrophysics Data System (ADS)

The fractional index of a (possibly singular) Q-Gorenstein del Pezzo surface X is the greatest rational number r such that -K_X\\equiv rH, where H is a primitive Cartier divisor. This paper describes the set of values taken by fractional indices of del Pezzo surfaces with log terminal singularities. Bibliography: 7 titles.

Alekseev, V. A.

1989-06-01

54

Segregation of Eucalyptus dunnii logs using acoustics  

Microsoft Academic Search

Wood properties at harvest-age vary enormously both within and among Eucalyptus trees, leading to a wide range in sawlog quality. One key property determining value of sawn boards is wood stiffness, with boards being allocated to different strength classes and priced accordingly. To maximise returns from sawing, it is highly desirable to be able to sort logs, either in the

Ross L Dickson; Carolyn A Raymond; William Joe; Col A Wilkinson

2003-01-01

55

Geophysical logs in British stratigraphy  

SciTech Connect

This Special Report outlines the stratigraphic applications of the main geophysical logging tools. It characterises the British geological succession by means of the geophysical log signatures of its principle constituent formations. A large amount of previously unpublished data is provided on a geographical area long known for its importance in the development of the science of stratigraphy. The book in units modern developments of petroleum industry geophysical techniques with long-established stratigraphical discovery/research. Contents include: Introduction; Types of logs commonly used; Some geological uses of geophysical logs; Log signatures in British Stratigraphy; References.

Whittaker, A.; Holliday, D.W.; Penn, I.E.

1985-01-01

56

[Computerized logP prediction using fragment methods].  

PubMed

Lipophilicity, expressed by the logarithm of octanol/water partition coefficient (logP) is an important physico-chemical property in rational drug design. Beside the experimental determination, the calculation of logP based on the chemical structure is frequently necessary. This has led to the development of numerous logP prediction methods. In the present paper the fragment type approaches and their computer softwares are surveyed (Table I.). The compilation is extended to the introduction and evaluation of a recently developed method of Meylan and Howard [21]: Atom/Fragment Contribution, AFC method (KOWWIN for Windows, software) which possesses the unique option, the Experimental Value Adjusted, EVA logP prediction. The author compared the highly precise experimental logP values of 28 drugs measured in her laboratory with calculated logP values obtained by four approaches: KOWWIN, CLOGP, PROLOGP, ACD/logP. The best prediction was found as follows in decreasing order: KOWWIN (r = 0.983), CLOGP (r = 0.978), PROLOGP/Combined (r = 0.953), ACD/logP (r = 0.942), PROLOGP/Atomic5 (r = 0.940), PROLOGP/Rekker (r = 0.909). The limits of current logP prediction methods (intramolecular H-bond formation, tautomerization, conformation changes, etc.) and the promising future of the molecular lipophilicity potential, MLP, [42] in drug design is also discussed. PMID:9528148

Takácsné, N K

1998-01-01

57

The Lincoln Log  

NSDL National Science Digital Library

What exactly was Abraham Lincoln doing on June 11, 1850? As it turns out, he was writing a letter to one Nathaniel Hay, describing the details of a potential home-improvement project. If you're looking for more details on Lincoln's daily doings, click on over to The Lincoln Log. The information on the site was compiled by the Lincoln Sesquicentennial Commission, and in 2003, the materials were redesigned by the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign. Visitors to the site can find out what Lincoln was doing on a particular day by using the drop-down menus on the homepage, and they can also browse by year or click on the "Today's Date in Lincoln's Life" section. Also, visitors can use the "Browse New Entries" to look over newly added materials.

58

Primary detection of hardwood log defects using laser surface scanning  

NASA Astrophysics Data System (ADS)

The use of laser technology to scan hardwood log surfaces for defects holds great promise for improving processing efficiency and the value and volume of lumber produced. External and internal defect detection to optimize hardwood log and lumber processing is one of the top four technological needs in the nation"s hardwood industry. The location, type, and severity of defects on hardwood logs are the key indicators of log quality and value. These visual cues provide information about internal log characteristics and products for which the log is suitable. We scanned 162 logs with a high-resolution industrial four-head laser surface scanner. The resulting data sets contain hundreds of thousands of three-dimensional coordinate points. The size of the data and noise presented special problems during processing. Robust regression models were used to fit geometric shapes to the data. The estimated orthogonal distances between the fitted model and the log surface are converted to a two-dimensional image to facilitate defect detection. Using robust regression methods and standard image processing tools we have demonstrated that severe surface defects on hardwood logs can be detected using height and contour analyses of three-dimensional laser scan data.

Thomas, Edward; Thomas, Liya; Mili, Lamine; Ehrich, Roger W.; Abbott, A. Lynn; Shaffer, Clifford

2003-05-01

59

3. Log bunkhouse (far left), log chicken house (left of ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Log bunkhouse (far left), log chicken house (left of center), equipment shed (center), and workshop (far right). View to northwest. - William & Lucina Bowe Ranch, County Road 44, 0.1 mile northeast of Big Hole River Bridge, Melrose, Silver Bow County, MT

60

Acoustic paramagnetic logging tool  

DOEpatents

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth3 s magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation . The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores.

Vail, III, William B. (Bothell, WA)

1988-01-01

61

Oracle Log Buffer Queueing  

SciTech Connect

The purpose of this document is to investigate Oracle database log buffer queuing and its affect on the ability to load data using a specialized data loading system. Experiments were carried out on a Linux system using an Oracle 9.2 database. Previous experiments on a Sun 4800 running Solaris had shown that 100,000 entities per minute was an achievable rate. The question was then asked, can we do this on Linux, and where are the bottlenecks? A secondary question was also lurking, how can the loading be further scaled to handle even higher throughput requirements? Testing was conducted using a Dell PowerEdge 6650 server with four CPUs and a Dell PowerVault 220s RAID array with 14 36GB drives and 128 MB of cache. Oracle Enterprise Edition 9.2.0.4 was used for the database and Red Hat Linux Advanced Server 2.1 was used for the operating system. This document will detail the maximum observed throughputs using the same test suite that was used for the Sun tests. A detailed description of the testing performed along with an analysis of bottlenecks encountered will be made. Issues related to Oracle and Linux will also be detailed and some recommendations based on the findings.

Rivenes, A S

2004-12-08

62

Logging concessions enable illegal logging crisis in the peruvian Amazon.  

PubMed

The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US-Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3% of all concessions supervised by authorities were suspected of major violations. Of the 609 total concessions, nearly 30% have been cancelled for violations and we expect this percentage to increase as investigations continue. Moreover, the nature of the violations indicate that the permits associated with legal concessions are used to harvest trees in unauthorized areas, thus threatening all forested areas. Many of the violations pertain to the illegal extraction of CITES-listed timber species outside authorized areas. These findings highlight the need for additional reforms. PMID:24743552

Finer, Matt; Jenkins, Clinton N; Sky, Melissa A Blue; Pine, Justin

2014-01-01

63

Logging Concessions Enable Illegal Logging Crisis in the Peruvian Amazon  

NASA Astrophysics Data System (ADS)

The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US-Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3% of all concessions supervised by authorities were suspected of major violations. Of the 609 total concessions, nearly 30% have been cancelled for violations and we expect this percentage to increase as investigations continue. Moreover, the nature of the violations indicate that the permits associated with legal concessions are used to harvest trees in unauthorized areas, thus threatening all forested areas. Many of the violations pertain to the illegal extraction of CITES-listed timber species outside authorized areas. These findings highlight the need for additional reforms.

Finer, Matt; Jenkins, Clinton N.; Sky, Melissa A. Blue; Pine, Justin

2014-04-01

64

Well Logging and Logging Analysis of UHP metamorphic Rocks in CCSD Main Hole (0-2000m)  

NASA Astrophysics Data System (ADS)

CCSD logging engineering gather many modern high technologies and employs various advanced logging tools to survey the sidewall continuously. This can obtain various physical, chemical, geometrical, etc in-situ information of the borehole's profile. So well logging is one of the most important parts and pivotal technologies in the project of CCSD. The main logging methods in CCSD-MH(0-2000m) are laterolog (Rd,Rs), gamma ray(GR), nature gamma spectrometry(U, TH, K), density(DEN), photo electric section exponent (Pe), compensated neutron(CNL), multipole array acoustic (Vp, Vs, Vst), Simultaneous Acoustic-Resistivity-image(Star-II), temperature(T),magnetic susceptibility(MS), three component borehole magnetic and redox potential log,etc. The various metamorphic rocks can be classified by logging curves,and their physical parameters can be acquired by analyzing the response characters of various metamorphic rocks and by statistics. According to the logging cross plot, We can research the clustering of metamorphite's physical property. Five lithologic segments can be obtainend by logging curves. The GR, Th, U, K logging values of segment 1 is lower than the third, fourth and fiveth segment, higher than segment 2; The DEN, Pe values of segment 1 higher than the third, fourth and fiveth segments. The main rocks in segment 1,2,3,4,5 are eclogites, serpentinites, paragneiss, orthogneiss, and eclogites(containing silicon and muscovite ) respectively. Generally, eclogite contain rutile, silicon, muscovite, etc. minerals. These minerals have response obviously on log curves.There are rutile,ilmenite, pyrite mineralized, etc. Making use of DEN, Pe, susceptibility log values, these mineralized layers can be goodly demarcation. For example, on the rutile mineralzed layer, the logging curve response characters are of high density and Pe obviously. The key data of the synthetical seismic record is wave impedance. In this paper, Utilize the data of AC, DEN curves to calculate the wave impedance and compare with the VSP profile, finally analyze the reflectors of the CCSD-MH. Imaging log has a positioning system and very good vertical resolution, and can describe the geological features in detail. Various structure parameters (the size and occurrences of foliation, fracture, fault & vein) have been given by image logging. The main work of logging interpretation of CCSD have done as follows: 1) Character analysis of logging response and restoring the lithologic profile;2) Depth correction and Restoring orientation of cores; 3) Interpretation of imaging geological feature; 4) Research of rock's mechanics character, sonic anisotropy and formation stress; 5) Comparison wave impedance with the VSP profile,analyzing the reflectors; 6)The interpretation of magnetic susceptibility and temperature log. The logging analysis results of UHP metamorphic rocks in CCSD-MH(0-2000m) show that responses of logs curve are abundant, the physical properties of various metamorphic rocks are visibly different;image logging has a positioning system and very good vertical resolution, and can describe the geological features in detail;lithologic segments and mineralized layers can be goodly demarcation by log curves;the log curves can be used for standardizing the geophysical survey, for example, mark out the reflected interface of seismic wave;comparing the results of log curves value with core laboratory analysis,they have good consistency;and so on.

Pan, H.; Niu, Y.; Wang, W.; Zhu, L.; Xu, D.; Wu, H.; Li, S.; Luo, M.

2004-12-01

65

Programs for Computer Simulation of Hardwood Log Sawing.  

National Technical Information Service (NTIS)

Four computer programs were developed at the University of Kentucky as simulation models for investigating factors affecting sawn log value over four hardwood sawing methods: quadrant sawing, cant sawing, decision sawing, and live sawing with rerip for gr...

D. B. Richards D. W. Lewis E. H. Bulgrin W. K. Adkins

1980-01-01

66

Logging and Recovery in Prisma.  

National Technical Information Service (NTIS)

The recovery methods for main memory database systems are mostly based on maintaining a disk based log and checkpoint. The information written to the log usually consists of low level information, before/after images, or single tuple updates. The effect o...

C. A. Vandenberg M. L. Kersten

1990-01-01

67

Mud logging principles and interpretation  

SciTech Connect

This handbook on mud logging examines the physical and chemical processes affecting hydrocarbons before and during the drilling process and in transmission to the surface. Gas-show characteristics and behavior are correlated with other borehole evidence as a means of formation evaluation. Although mud logging technology has achieved significant recent advances, the basic principles underlying the logging and interpretation of a gas show remain the same. Mud logging techniques that are recognized throughout the industry are evaluated and standards for their use and interpretation are recommended. Contents include: 1. Introduction: background, mud loggings. 2. Origins of gas shows: introduction-definitions, ''gas shows'' and ''gas kicks,'' type of gas show-sources of gas in mud, sources of gas in place. 3. Factors affecting gas shows: downhole influences-formation interaction, circulating system; surface influences-surface mud system, analysis system. 4. Oil shows: reservoir description-cuttings evaluation, hydrocarbon evaluation, solid hydrocarbons. 5. Show evaluation: interpretation-methods, examples; conclusions. Index.

Whittaker, A.

1985-01-01

68

Estimating thermal conductivity from core and well log data  

NASA Astrophysics Data System (ADS)

The aim of the presented work was to introduce a method of estimating thermal conductivity using well log data. Many petrophysical properties of rocks can be determined both by laboratory measurements and well-logs. It is thus possible to apply geophysical data to empirical models based on relationships between laboratory measured parameters and derive continuous thermal conductivity values in well profiles. Laboratory measurements were conducted on 62 core samples of Meso-Paleozoic rocks from the Carpathian Foredeep. Mathematical models were derived using multiple regression and neural network methods. Geophysical data from a set of seven well logs: density, sonic, neutron, gamma ray, spectral gamma ray, caliper and resistivity were applied to the obtained models. Continuous thermal conductivity values were derived in three well profiles. Analysis of the obtained results shows good consistence between laboratory data and values predicted from well log data.

G?sior, Irena; Przelaskowska, Anna

2014-08-01

69

Estimating thermal conductivity from core and well log data  

NASA Astrophysics Data System (ADS)

The aim of the presented work was to introduce a method of estimating thermal conductivity using well log data. Many petrophysical properties of rocks can be determined both by laboratory measurements and well-logs. It is thus possible to apply geophysical data to empirical models based on relationships between laboratory measured parameters and derive continuous thermal conductivity values in well profiles. Laboratory measurements were conducted on 62 core samples of Meso-Paleozoic rocks from the Carpathian Foredeep. Mathematical models were derived using multiple regression and neural network methods. Geophysical data from a set of seven well logs: density, sonic, neutron, gamma ray, spectral gamma ray, caliper and resistivity were applied to the obtained models. Continuous thermal conductivity values were derived in three well profiles. Analysis of the obtained results shows good consistence between laboratory data and values predicted from well log data.

G?sior, Irena; Przelaskowska, Anna

2014-04-01

70

A regularity-based modeling of oil borehole logs  

NASA Astrophysics Data System (ADS)

Multifractional Brownian motions (mBms) are successfully used to describe borehole logs behavior. These local fractal models allow to investigate the depth-evolution of regularity of the logs, quantified by the Hölder exponent (H). In this study, a regularity analysis is carried out on datasets recorded in Algerian oil boreholes located in different geological settings. The obtained regularity profiles show a clear correlation with lithology. Each lithological discontinuity corresponds to a jump in H value. Moreover, for a given borehole, all the regularity logs are significantly correlated and lead to similar lithological segmentations. Therefore, the Hölderian regularity is a robust property which can be used to characterize lithological heterogeneities. However, this study does not draw any relation between the recorded physical property and its estimated regularity degree for all the analyzed logs. Keywords: well logs, regularity, Hölder exponent, multifractional Brownian motion

Gaci, Said; Zaourar, Naima

2013-04-01

71

A prototype vision system for analyzing CT imagery of hardwood logs  

Microsoft Academic Search

To fully optimize the value of material produced from a hardwood log requires information about type and location of internal defects in the log. This paper describes a prototype vision system that automatically locates and identifies certain classes of defects in hardwood logs. This system uses computer tomograph (CT) imagery. The system uses a number of processing steps. A set

Dongping Zhu; Richard W. Conners; Daniel L. Schmoldt; Philip A. Araman

1996-01-01

72

No chiral truncation of quantum log gravity?  

NASA Astrophysics Data System (ADS)

At the classical level, chiral gravity may be constructed as a consistent truncation of a larger theory called log gravity by requiring that left-moving charges vanish. In turn, log gravity is the limit of topologically massive gravity (TMG) at a special value of the coupling (the chiral point). We study the situation at the level of linearized quantum fields, focussing on a unitary quantization. While the TMG Hilbert space is continuous at the chiral point, the left-moving Virasoro generators become ill-defined and cannot be used to define a chiral truncation. In a sense, the left-moving asymptotic symmetries are spontaneously broken at the chiral point. In contrast, in a non-unitary quantization of TMG, both the Hilbert space and charges are continuous at the chiral point and define a unitary theory of chiral gravity at the linearized level.

Andrade, Tomás; Marolf, Donald

2010-03-01

73

Quantitative Generalizations for Catchment Sediment Yield Following Plantation Logging  

NASA Astrophysics Data System (ADS)

While there is a reasonably clear qualitative understanding of the impact of forest plantations on sediment yield, there is a lack of quantitative generalizations. Such generalizations would be helpful for estimating the impacts of proposed forestry operations and would aid the spread of knowledge amongst both relevant professionals and new students. This study therefore analyzed data from the literature to determine the extent to which quantitative statements can be established. The research was restricted to the impact of plantation logging on catchment sediment yield as a function of ground disturbance in the years immediately following logging, in temperate countries, and does not consider landslides consequent upon tree root decay. Twelve paired catchment studies incorporating pre- and post-logging measurements of sediment yield were identified, resulting in forty-three test catchments (including 14 control catchments). Analysis yielded the following principal conclusions: 1) Logging generally provokes maximum annual sediment yields of less than a few hundred t km-2 yr-1; best management practice can reduce this below 100 t km-2 yr-1. 2) At both the annual and event scales, the sediment yield excess of a logged catchment over a control catchment is within one order of magnitude, except with severe ground disturbance. 3) There is no apparent relationship between sediment yield impact and the proportion of catchment logged. The effect depends on which part of the catchment is altered and on its connectivity to the stream network. 4) The majority of catchments delivered their maximum sediment yield in the first two years after logging. The logging impacts were classified in terms of the absolute values of specific sediment yield, the values relative to those in the control catchments for the same period and the values relative both to the control catchment and the pre-logging period. Most studies have been for small catchments (< 10 km2) and temperate regions; the impact at large catchment scales and in tropical regions requires further research.

Bathurst, James; Iroume, Andres

2014-05-01

74

Numerical simulation of responses for cased-hole density logging  

NASA Astrophysics Data System (ADS)

Stabilizing or stimulating oil production in old oil fields requires density logging in cased holes where open-hole logging data are either missing or of bad quality. However, measured values from cased-hole density logging are more severely influenced by factors such as fluid, casing, cement sheath and the outer diameter of the open-hole well compared with those from open-hole logging. To correctly apply the cased-hole formation density logging data, one must eliminate these influences on the measured values and study the characteristics of how the cased-hole density logging instrument responds to these factors. In this paper, a Monte Carlo numerical simulation technique was used to calculate the responses of the far detector of a cased-hole density logging instrument to in-hole fluid, casing wall thickness, cement sheath density and the formation and thus to obtain influence rules and response coefficients. The obtained response of the detector is a function of in-hole liquid, casing wall thickness, the casing's outer diameter, cement sheath density, open-hole well diameter and formation density. The ratio of the counting rate of the detector in the calibration well to that in the measurement well was used to get a fairly simple detector response equation and the coefficients in the equation are easy to acquire. These provide a new way of calculating cased-hole density through forward modelling methods.

Wu, Wensheng; Fu, Yaping; Niu, Wei

2013-10-01

75

A Guide to Hardwood Log Grading.  

National Technical Information Service (NTIS)

The report, a guide to hardwood log grading (Revised) was developed as a teaching aid and field reference in grading hardwood logs. The study outlines basic principles and gives detailed practical applications, with illustrations, in grading hardwood logs...

E. D. Rast D. L. Sonderman G. L. Gammon

1973-01-01

76

Evaluation of waste mushroom logs as a potential biomass resource for the production of bioethanol  

Microsoft Academic Search

In order to investigate the possibility of using waste mushroom logs as a biomass resource for alternative energy production, the chemical and physical characteristics of normal wood and waste mushroom logs were examined. Size reduction of normal wood (145kWh\\/tone) required significantly higher energy consumption than waste mushroom logs (70kWh\\/tone). The crystallinity value of waste mushroom logs was dramatically lower (33%)

Jae-Won Lee; Bon-Wook Koo; Joon-Weon Choi; Don-Ha Choi; In-Gyu Choi

2008-01-01

77

Degraded lands worth protecting: the biological importance of Southeast Asia's repeatedly logged forests  

PubMed Central

Southeast Asia is a hotspot of imperilled biodiversity, owing to extensive logging and forest conversion to oil palm agriculture. The degraded forests that remain after multiple rounds of intensive logging are often assumed to be of little conservation value; consequently, there has been no concerted effort to prevent them from being converted to oil palm. However, no study has quantified the biodiversity of repeatedly logged forests. We compare the species richness and composition of birds and dung beetles within unlogged (primary), once-logged and twice-logged forests in Sabah, Borneo. Logging had little effect on the overall richness of birds. Dung beetle richness declined following once-logging but did not decline further after twice-logging. The species composition of bird and dung beetle communities was altered, particularly after the second logging rotation, but globally imperilled bird species (IUCN Red List) did not decline further after twice-logging. Remarkably, over 75 per cent of bird and dung beetle species found in unlogged forest persisted within twice-logged forest. Although twice-logged forests have less biological value than primary and once-logged forests, they clearly provide important habitat for numerous bird and dung beetle species. Preventing these degraded forests from being converted to oil palm should be a priority of policy-makers and conservationists.

Edwards, David P.; Larsen, Trond H.; Docherty, Teegan D. S.; Ansell, Felicity A.; Hsu, Wayne W.; Derhe, Mia A.; Hamer, Keith C.; Wilcove, David S.

2011-01-01

78

Construction of permeability maps from porosity logs using fractal approach  

NASA Astrophysics Data System (ADS)

Analysis of permeability data from several wells show that permeability follows fractal behaviour. Often permeability is measured using rock samples in the laboratory or using well tests, however, such data is often very sparse and takes long time to generate such data for reservoir simulation purpose. Hence, we present an alternative approach to generate permeability maps using porosity logs from the wells. This approach relies on the fractal dimension analysis of the grain size distribution of the rock samples and tortuosity of the representative rock samples of the reservoir. Our analysis is based on the several real field well logs having porosity measurements. We have compared the permeability values obtained from fractal method from the observed values in the laboratory and it agrees very well. Hence, our method will be useful in generating reliable permeability maps for the reservoir simulation from easily available porosity (Neutron and Density logs) logs.

Dimri, V. P.

2012-12-01

79

Log evaluation techniques in Uinta Basin found faulty  

SciTech Connect

Gas accumulations in Lower Tertiary and Upper Cretaceous formations are the subject of widespread exploration in the Uinta basin. The complex lithology of these formations has hindered the usefulness of the sonic, density and neutron logs when conventional analysis techniques are applied. This work suggests more accurate parameter values that should be used to calculate porosity from the aforementioned suite of logs, when used in like lithologic units. 3 refs.

Osoba, J.S.; Carroll, H.; Gist, R.

1981-06-01

80

The Dry Eye Disease Activity Log Study  

PubMed Central

Prolonged visually stressful activities aggravate dry eye disease (DED). The duration spent on such activities and their relationship with DED clinical features were investigated. Patients completed an activity log as they performed their usual activities over 1 typical rest day and 1 typical work day. The log included time spent in an air-conditioned environment, windy environment, driving, watching television, computer use, reading, watching a movie in the theatre, and wearing contact lens. Average daily activity hours were calculated and correlated with clinical features of DED. Thirty-five logs were returned. Positive correlation was found between watching television and episodic blurred vision (P < 0.01). Computer use was negatively correlated with episodic blur vision, burning sensation, and gritty sensation (P < 0.05). Negative correlation was found between time spent in windy environments, driving, reading, and certain DED symptoms (P < 0.05). Reading correlated positively with severity of corneal fluorescein staining and reduced Schirmer's values (P < 0.03). The use of air conditioning correlated negatively with episodic blur vision but positively with visual blurring that improves with lubricants (P = 0.02). This study is the first to evaluate the relationship between time spent on DED-aggravating activities and DED clinical features. Negative correlations between certain activities and DED symptoms suggest an unconscious modification of lifestyle to alleviate symptoms.

Iyer, Jayant V.; Lee, Sze-Yee; Tong, Louis

2012-01-01

81

Well-logging activities in Russia  

SciTech Connect

The report is a brief survey of the current state of well-logging service in Russia (number and types of crews, structure of well-logging jobs, types of techniques used, well-logging equipment, auxiliary downhole jobs, etc.). Types and peculiarities of well data acquisition and processing hardware and software are discussed (petrophysics included). New well-logging technologies used in Russia (new methods of electric logging data processing, electromagnetic logging, pulse neutron logging, nuclear magnetic resonance logging, acoustic tomography, logging-testing-logging technique, etc.) are surveyed. Comparison of the Tengiz field (Kazakhstan) well data obtained by Schlumberger and Neftegazgeofizika Association crews is given. Several problems and drawbacks in equipment and technology used by well-logging crews in Russia are discussed.

Savostyanov, N.A. (Neftegazgeofizika, Moscow (Russian Federation))

1993-09-01

82

Log Truck-Weighing System  

NASA Technical Reports Server (NTRS)

ELDEC Corp., Lynwood, Wash., built a weight-recording system for logging trucks based on electronic technology the company acquired as a subcontractor on space programs such as Apollo and the Saturn launch vehicle. ELDEC employed its space-derived expertise to develop a computerized weight-and-balance system for Lockheed's TriStar jetliner. ELDEC then adapted the airliner system to a similar product for logging trucks. Electronic equipment computes tractor weight, trailer weight and overall gross weight, and this information is presented to the driver by an instrument in the cab. The system costs $2,000 but it pays for itself in a single year. It allows operators to use a truck's hauling capacity more efficiently since the load can be maximized without exceeding legal weight limits for highway travel. Approximately 2,000 logging trucks now use the system.

1977-01-01

83

Mail LOG: Program operating instructions  

NASA Technical Reports Server (NTRS)

The operating instructions for the software package, MAIL LOG, developed for the Scout Project Automatic Data System, SPADS, are provided. The program is written in FORTRAN for the PRIME 300 computer system. The MAIL LOG program has the following four modes of operation: (1) INPUT - putting new records into the data base (2) REVISE - changing or modifying existing records in the data base (3) SEARCH - finding special records existing in the data base (4) ARCHIVE - store or put away existing records in the data base. The output includes special printouts of records in the data base and results from the INPUT and SEARCH modes. The MAIL LOG data base consists of three main subfiles: Incoming and outgoing mail correspondence; Design Information Releases and Releases and Reports; and Drawings and Engineering orders.

Harris, D. K.

1979-01-01

84

Log amplifier with pole-zero compensation  

DOEpatents

A logarithmic amplifier circuit provides pole-zero compensation for improved stability and response time over 6-8 decades of input signal frequency. The amplifer circuit includes a first operational amplifier with a first feedback loop which includes a second, inverting operational amplifier in a second feedstock loop. The compensated output signal is provided by the second operational amplifier with the log elements, i.e., resistors, and the compensating capacitors in each of the feedback loops having equal values so that each break point is offset by a compensating break point or zero.

Brookshier, W.

1985-02-08

85

47 CFR 73.1820 - Station log.  

Code of Federal Regulations, 2013 CFR

...log. (a) Entries must be made in the station log either manually by a person designated...of observation must be included in each log entry. The following information...small make the required entries in the log manually at that time; (5)...

2013-10-01

86

Query clustering using user logs  

Microsoft Academic Search

Query clustering is a process used to discover frequently asked questions or most popular topics on a search engine. This process is crucial for search engines based on question-answering. Because of the short lengths of queries, approaches based on keywords are not suitable for query clustering. This paper describes a new query clustering method that makes use of user logs

Ji-rong Wen; Jian-yun Nie; Hong-Jiang Zhang

2002-01-01

87

A New Approach to Logging.  

ERIC Educational Resources Information Center

In response to high numbers of preventable fatal accidents in the logging industry, the Occupational Safety and Health Administration (OSHA) developed a week-long logger safety training program that includes hands-on learning of safety techniques in the woods. Reaching small operators has been challenging; outreach initiatives in Maine, North…

Miles, Donna

2001-01-01

88

Downhole Memory-Logging Tools  

SciTech Connect

Logging technologies developed for hydrocarbon resource evaluation have not migrated into geothermal applications even though data so obtained would strengthen reservoir characterization efforts. Two causative issues have impeded progress: (1) there is a general lack of vetted, high-temperature instrumentation, and (2) the interpretation of log data generated in a geothermal formation is in its infancy. Memory-logging tools provide a path around the first obstacle by providing quality data at a low cost. These tools feature onboard computers that process and store data, and newer systems may be programmed to make ''decisions''. Since memory tools are completely self-contained, they are readily deployed using the slick line found on most drilling locations. They have proven to be rugged, and a minimum training program is required for operator personnel. Present tools measure properties such as temperature and pressure, and the development of noise, deviation, and fluid conductivity logs based on existing hardware is relatively easy. A more complex geochemical tool aimed at a quantitative analysis of potassium, uranium and thorium will be available in about one year, and it is expandable into all nuclear measurements common in the hydrocarbon industry. A second tool designed to sample fluids at conditions exceeding 400 C (752 F) is in the proposal stage. Partnerships are being formed between the geothermal industry, scientific drilling programs, and the national laboratories to define and develop inversion algorithms relating raw tool data to more pertinent information.

Lysne, Peter

1992-03-24

89

Downhole memory-logging tools  

SciTech Connect

Logging technologies developed hydrocarbon resource evaluation have not migrated into geothermal applications even though data so obtained would strengthen reservoir characterization efforts. Two causative issues have impeded progress: (i) there is a general lack of vetted, high-temperature instrumentation, and (ii) the interpretation of log data generated in a geothermal formation is in its infancy. Memory-logging tools provide a path around the first obstacle by providing quality data at a low cost. These tools feature on-board computers that process and store data, and newer systems may be programmed to make decisions.'' Since memory tools are completely self-contained, they are readily deployed using the slick line found on most drilling locations. They have proven to be rugged, and a minimum training program is required for operator personnel. Present tools measure properties such as temperature and pressure, and the development of noise, deviation, and fluid conductivity logs based on existing hardware is relatively easy. A more complex geochemical tool aimed at a quantitative analysis of potassium, uranium and thorium will be available in about on year, and it is expandable into all nuclear measurements common in the hydrocarbon industry. A second tool designed to sample fluids at conditions exceeding 400{degrees}C is in the proposal stage. Partnerships are being formed between the geothermal industry, scientific drilling programs, and the national laboratories to define and develop inversion algorithms relating raw tool data to more pertinent information. 8 refs.

Lysne, P.

1992-01-01

90

Continuous shear wave logging apparatus  

SciTech Connect

Apparatus for continuous shear wave logging of a borehole consisting of a sonde instrument having retractable, expandable coupling arms for rigidly engaging the borehole wall to exert repetitive torqueing action while continuously moving uphole. The sonde includes spaced detector coupling arms in continual contact with the borehole wall and polarized for detection of the repetitive propagated shear waves.

Brown, G. L.

1985-10-29

91

Defect Detection in Wooden Logs Using Ground Penetrating Radar  

NASA Astrophysics Data System (ADS)

Presently there are no suitable non-invasive methods for precisely detecting the subsurface defects in logs in real time. Internal defects such as knots, decays, and embedded metals are of greatest concern for lumber production. Nondestructive scanning of logs using Ground Penetrating Radar (GPR) to detect defects in logs prior to sawing can greatly increase the productivity and yield of high value lumber, and prevent damage to saw blade from embedded metals. In this research, the GPR scanned data has been analyzed to detect subsurface defects such as metals, decays, and knots. Also, GPR offers high speed scanning capability which is needed for future on-line implementation in saw mills. This paper explains the advantages of the GPR technique, experimental setup and parameters used, and data processing for detection of subsurface defects in logs. The results show that GPR can be a very promising technique for future on-line implementation in saw mills.

Halabe, Udaya B.; Agrawal, Sachin; Gopalakrishnan, Bhaskaran; Grushecky, Shawn

2007-03-01

92

Log-concave probability and its applications  

Microsoft Academic Search

In many applications, assumptions about the log-concavity of a probability distribution allow just enough special structure to yield a workable theory. This paper catalogs a series of theorems relating log-concavity and\\/or log-convexity of probability density functions, distribution functions, reliability functions, and their integrals. We list a large number of commonly-used probability distributions and report the log-concavity or log-convexity of their

Mark Bagnoli; Ted Bergstrom

1989-01-01

93

Chemical logging of geothermal wells  

DOEpatents

The presence of geothermal aquifers can be detected while drilling in geothermal formations by maintaining a chemical log of the ratio of the concentrations of calcium to carbonate and bicarbonate ions in the return drilling fluid. A continuous increase in the ratio of the concentrations of calcium to carbonate and bicarbonate ions is indicative of the existence of a warm or hot geothermal aquifer at some increased depth.

Allen, Charles A. (Idaho Falls, ID); McAtee, Richard E. (Idaho Falls, ID)

1981-01-01

94

An Analysis of Main-Memory and Log Space Usage in Extended Ephemeral Logging  

Microsoft Academic Search

Extended Ephemeral Logging (XEL) is a database logging and recovery technique which manages a log of recovery data by partitioning\\u000a it into a series of logically circular generations. XEL copies longer-lived log data from one generation to another in order\\u000a to reclaim more quickly the space occupied by shorter-lived log data. As a result of copying, records in the log

Richard D. Regan; Alex Delis

2001-01-01

95

Log Sort Yard Economics, Planning, and Feasibility.  

National Technical Information Service (NTIS)

This publication discusses basic marketing and economic concepts, planning approach, and feasibility methodology for assessing log sort yard operations. Special attention is given to sorting small-diameter and underutilized logs from forest restoration, f...

J. R. Dramm R. Govett T. Bilek G. L. Jackson

2004-01-01

96

Tucker Wireline Open Hole Wireline Logging  

SciTech Connect

The Tucker Wireline unit ran a suite of open hole logs right behind the RMOTC logging contractor for comparison purposes. The tools included Dual Laterolog, Phased Induction, BHC Sonic, and Density-Porosity.

Milliken, M.

2002-05-23

97

Geophysical logging for mineral and engineering applications  

SciTech Connect

The book contains nonpetroleum logging methods and the more exotic techniques. Contents: History; Formation types; Borehole effects and mud; Electric logging systems; Radioactivity methods; Magnetic methods; Mechanical methods and sampling methods; Analog and digital systems; Interpretation methods.

Hallenburg, J.K.

1983-01-01

98

29 CFR 1918.88 - Log operations.  

Code of Federal Regulations, 2013 CFR

...LONGSHORING Handling Cargo § 1918.88 Log operations. (a) Working in holds. When loading logs into the holds of vessels and using dumper...walking and working surface and that is used in the loading of logs onto vessels from the water....

2013-07-01

99

29 CFR 1917.18 - Log handling.  

Code of Federal Regulations, 2013 CFR

...binders are being removed. (c) Logs shall be hoisted by two slings...designed for safe hoisting. (d) Logs placed adjacent to vehicle curbs...over one tier high unless placed in bunks or so stacked as not to...to employees. (e) Before logs are slung up from the...

2013-07-01

100

Secure audit logs to support computer forensics  

Microsoft Academic Search

In many real-world applications, sensitive information must be kept it log files on an untrusted machine. In the event that an attacker captures this machine, we would like to guarantee that he will gain little or no information from the log files and to limit his ability to corrupt the log files. We describe a computationally cheap method for making

Bruce Schneier; John Kelsey

1999-01-01

101

A Dual Actuator Logging Disk Architecture  

Microsoft Academic Search

In this paper, we present a dual actuator logging disk ar- chitecture to minimize write access latencies. We reduce small synchronous write latency using the notion of log- ging writes, i.e. writing to free sectors near the current disk head location. However, we show through simulations that logging writes by itself is not sufficient to reduce write ac- cess latencies,

John A. Chandy

102

Dual actuator logging disk architecture and modeling  

Microsoft Academic Search

In this paper, we present a dual actuator logging disk architecture to minimize write access latencies. We reduce small synchronous write latency using the notion of logging writes, i.e. writing to free sectors near the current disk head location. However, we show through analytic models and simulations that logging writes by itself is not sufficient to reduce write access latencies,

John A. Chandy

2007-01-01

103

Formation productivity evaluation from temperature logs  

Microsoft Academic Search

After a brief review of the use of temperature logs for measuring the volume of gas flow in a borehole, this paper deals with the application of temperature logs to evaluate the mechanism of gas production. A method for evaluation of the formation productivity is introduced, making use of a temperature log of the flowing gas well, the reservoir temperature

J. M. Bird; N. Frost

1965-01-01

104

On the Computation of the Discrete Log-Polar Transform  

Microsoft Academic Search

This paper reports an algorithm for computing the log-polar transform (LPT) of a digital image using optimal parameters for use in an active vision system. In the past, only cursory attention has been given to the selection of transform parameters. This is likely because the exact values of the parameters are of little significance in the transform when the image

Richard Alan Peters

105

Predicting logP of pesticides using different software.  

PubMed

We compared experimental and calculated logP values using a data set of 235 pesticides and experimental values from four different sources: The Pesticide Manual, Hansch Manual, ANPA and KowWin databases. LogP were calculated with four softwares: HyperChem, Pallas, KowWin and TOPKAT. Crossed comparison of the experimental and calculated values proved useful, especially for pesticides. These are harder to study than simpler organic compounds. Structurally they are complex, heterogeneous and similar to drugs from a chemical point of view. They offer an interesting way to verify the goodness of the different methods. Other studies compared several logP predictors using a single set of experimental values taken as a reference. Here we discuss the utility of the different logP predictors, with reference to experimental data found in different databases. This offers three advantages: (1) it avoids bias due to the assumption that one single data set is correct; (2) a given predictor can be developed on the same data set used for evaluation; (3) it takes account of experimental variability and can compare it with the predictor's variability. In our study Pallas and KowWin gave the best results for prediction, followed by TOPKAT. PMID:14512120

Benfenati, E; Gini, G; Piclin, N; Roncaglioni, A; Varì, M R

2003-12-01

106

Logging Residue as Fuelwood in Forest Farmers Houses.  

National Technical Information Service (NTIS)

Rising oil prices have increased the interest in wood firing. Many forest farmers will find it profitable to use wood fuel from their own forest. A large part of the logging costs is the cost of the farmers labour. The value of this labour is no longer su...

J. E. Mattson E. Sundstedt

1977-01-01

107

Data Mining of Network Logs  

NASA Technical Reports Server (NTRS)

The statement of purpose is to analyze network monitoring logs to support the computer incident response team. Specifically, gain a clear understanding of the Uniform Resource Locator (URL) and its structure, and provide a way to breakdown a URL based on protocol, host name domain name, path, and other attributes. Finally, provide a method to perform data reduction by identifying the different types of advertisements shown on a webpage for incident data analysis. The procedures used for analysis and data reduction will be a computer program which would analyze the URL and identify and advertisement links from the actual content links.

Collazo, Carlimar

2011-01-01

108

Chiral logs with staggered fermions  

NASA Astrophysics Data System (ADS)

We compute chiral logarithms in the presence of "taste" symmetry breaking of staggered fermions. The lagrangian of Lee and Sharpe is generalized and then used to calculate the logs in ? and K masses. We correct an error in Ref. [1]. MILC data with three light dynamical flavors can be well fit by our formulas. However, two new chiral parameters, which describeO( a2) hairpin diagrams for taste-nonsinglet mesons, enter in the fits. To obtain precise results for the physicalO( p4) coefficients, these new parameters will need to be bounded.

Aubin, C.; Bernard, C.; DeTar, C.; Gottlieb, Steven; Heller, Urs M.; Orginos, K.; Sugar, R.; Toussaint, D.

2003-05-01

109

O' Surgery Case Log Data, Where Art Thou?  

PubMed Central

Background The American College of Surgeons Case Log (ACS Case Log) represents a data system that satisfies the American Board of Surgery (ABS) Maintenance of Certification (MOC) program, yet has broad data fields for surgical subspecialties. Using the ACS Case Log, we have developed a method of data capture, categorization, and reporting of acute care surgery fellows' experiences. Study Design In July 2010, our Acute Care Surgery fellowship required our fellows to log their clinical experiences into the ACS Case Log. Cases were entered similar to billable documentation rules. Keywords were entered that specified institutional services and/or resuscitation types. This data was exported in comma separated value format, de-identified, and structured by Current Procedural Terminology (CPT) codes relevant to acute care surgery and sub-stratified by fellow and/or fellow year. Results Fifteen report types were created consisting of operative experience by service, procedure by major category (cardiothoracic, vascular, solid organ, abdominal wall, hollow viscus, and soft tissue), total resuscitations, ultrasound, airway, Intensive Care Unit services, basic neurosurgery, and basic orthopaedics. Results are viewable via a secure web application, accessible nationally, and exportable to many formats. Conclusions Utilizing the ACS Case Log satisfies the ABS MOC program requirements and provides a method for monitoring and reporting acute care surgery fellow experiences. This system is flexible to accommodate the needs of surgical subspecialties and their training programs. As documentation requirements expand, efficient clinical documentation is a must for the busy surgeon. Although, our data entry and processing method has the immediate capacity for acute care surgery fellowships nationwide, multiple larger decisions regarding national case log systems should be encouraged.

Patel, Mayur B; Guillamondegui, Oscar D; Ott, Mickey M; Palmiter, Kimberly A; May, Addison K

2012-01-01

110

Leak checker data logging system  

DOEpatents

A portable, high speed, computer-based data logging system for field testing systems or components located some distance apart employs a plurality of spaced mass spectrometers and is particularly adapted for monitoring the vacuum integrity of a long string of a superconducting magnets such as used in high energy particle accelerators. The system provides precise tracking of a gas such as helium through the magnet string when the helium is released into the vacuum by monitoring the spaced mass spectrometers allowing for control, display and storage of various parameters involved with leak detection and localization. A system user can observe the flow of helium through the magnet string on a real-time basis hour the exact moment of opening of the helium input valve. Graph reading can be normalized to compensate for magnet sections that deplete vacuum faster than other sections between testing to permit repetitive testing of vacuum integrity in reduced time.

Gannon, Jeffrey C. (Arlington, TX); Payne, John J. (Waterman, IL)

1996-01-01

111

Leak checker data logging system  

DOEpatents

A portable, high speed, computer-based data logging system for field testing systems or components located some distance apart employs a plurality of spaced mass spectrometers and is particularly adapted for monitoring the vacuum integrity of a long string of a superconducting magnets such as used in high energy particle accelerators. The system provides precise tracking of a gas such as helium through the magnet string when the helium is released into the vacuum by monitoring the spaced mass spectrometers allowing for control, display and storage of various parameters involved with leak detection and localization. A system user can observe the flow of helium through the magnet string on a real-time basis hour the exact moment of opening of the helium input valve. Graph reading can be normalized to compensate for magnet sections that deplete vacuum faster than other sections between testing to permit repetitive testing of vacuum integrity in reduced time. 18 figs.

Gannon, J.C.; Payne, J.J.

1996-09-03

112

Pentachlorophenol measurements in body fluids of people in log homes and workplaces  

Microsoft Academic Search

Human exposure to pentachlorophenol (PCP) was evaluated in the normal population (controls), residents of PCP-treated log homes, and persons exposed primarily in the workplace. Blood and urine samples were analyzed by gas chromatography after extraction and acetylation. For 34 controls, serum PCP values ranged from 15–75 ppb with a mean of 40 ppb. For 123 residents of log homes, serum

Richard E. Cline; Robert H. Hill; Donald L. Phillips; Larry L. Needham

1989-01-01

113

FACTORS DETERMINING THE SUITABILITY OF TREES AND LOGS FOR THE FACE VENEER INDUSTRY  

Microsoft Academic Search

Trees and logs suitable for use as fine face veneer command the absolute highest prices of any fiber products entering the commercial hardwood market. Many factors determine whether a tree or log will be suitable for face veneer and its value. These factors include species, size, geographic and site location, growth rate, and most importantly, uniformity of growth rate, color,

Daniel L. Cassens

114

Correlating Log Messages for System Diagnostics  

SciTech Connect

In large-scale computing systems, the sheer volume of log data generated presents daunting challenges for debugging and monitoring of these systems. The Oak Ridge Leadership Computing Facility s premier simulation platform, the Cray XT5 known as Jaguar, can generate a few hundred thousand log entries in less than a minute for many system level events. Determining the root cause of such system events requires analyzing and interpretation of a large number of log messages. Most often, the log messages are best understood when they are interpreted collectively rather than individually. In this paper, we present our approach to interpreting log messages by identifying their commonalities and grouping them into clusters. Given a set of log messages within a time interval, we group the messages based on source, target, and/or error type, and correlate the messages with hardware and application information. We monitor the Lustre log messages in the XT5 console log and show that such grouping of log messages assists in detecting the source of system events. By intelligent grouping and correlation of events in the log, we are able to provide system administrators with meaningful information in a concise format for root cause analysis.

Gunasekaran, Raghul [ORNL] [ORNL; Dillow, David A [ORNL] [ORNL; Shipman, Galen M [ORNL] [ORNL; Maxwell, Don E [ORNL] [ORNL; Hill, Jason J [ORNL] [ORNL; Park, Byung H [ORNL] [ORNL; Geist, Al [ORNL] [ORNL

2010-01-01

115

Frac packs complicate PNC log evaluation  

SciTech Connect

Borate-crosslinked fluids and/or ceramic proppants commonly included in frac-pack well completions can compliance pulsed neutron capture (PNC) log evaluation. PNC logs are routinely run in cased holes. Two common applications include identifying formation fluid and calculating the percent water saturation in the rock pore spaces near the well bore. The paper discusses PNC logs, a case history of a West Delta oil well, laboratory work, and results. Recommendations are given.

Bean, C.L.; Ali, S.A. [Chevron U.S.A. Production Co., New Orleans, LA (United States); Salaita, G.N. [Chevron Petroleum Technology Co., Houston, TX (United States)

1996-12-23

116

Optimal message log reclamation for independent checkpointing  

NASA Technical Reports Server (NTRS)

Independent (uncoordinated) check pointing for parallel and distributed systems allows maximum process autonomy but suffers from possible domino effects and the associated storage space overhead for maintaining multiple checkpoints and message logs. In most research on check pointing and recovery, it was assumed that only the checkpoints and message logs older than the global recovery line can be discarded. It is shown how recovery line transformation and decomposition can be applied to the problem of efficiently identifying all discardable message logs, thereby achieving optimal garbage collection. Communication trace-driven simulation for several parallel programs is used to show the benefits of the proposed algorithm for message log reclamation.

Wang, Yi-Min; Fuchs, W. Kent

1993-01-01

117

Flow rate logging seepage meter  

NASA Technical Reports Server (NTRS)

An apparatus for remotely measuring and logging the flow rate of groundwater seepage into surface water bodies. As groundwater seeps into a cavity created by a bottomless housing, it displaces water through an inlet and into a waterproof sealed upper compartment, at which point, the water is collected by a collection bag, which is contained in a bag chamber. A magnet on the collection bag approaches a proximity switch as the collection bag fills, and eventually enables the proximity switch to activate a control circuit. The control circuit then rotates a three-way valve from the collection path to a discharge path, enables a data logger to record the time, and enables a pump, which discharges the water from the collection bag, through the three-way valve and pump, and into the sea. As the collection bag empties, the magnet leaves the proximity of the proximity switch, and the control circuit turns off the pump, resets the valve to provide a collection path, and restarts the collection cycle.

Reay, William G. (Inventor); Walthall, Harry G. (Inventor)

1996-01-01

118

An 0(n log n) sorting network  

Microsoft Academic Search

The purpose of this paper is to describe a sorting network of size 0(n log n) and depth 0(log n). A natural way of sorting is through consecutive halvings: determine the upper and lower halves of the set, proceed similarly within the halves, and so on. Unfortunately, while one can halve a set using only 0(n) comparisons, this cannot be

Miklós Ajtai; János Komlós; Endre Szemerédi

1983-01-01

119

Efficient distributed recovery using message logging  

Microsoft Academic Search

Absfrucf: Various distributed algorithms am presented, that allow nodes in a distributed system to recover from crash failures efficiently. The algorithms are independent of the application programs running on the nodes. The algorithms log messages and checkpoint states of the processes to stable storage at each node. Both logging of messages and checkpointing of process states can be done asynchronously

A. Prasad Sistla; Jennifer L. Welch

1989-01-01

120

System Anomaly Detection: Mining Firewall Logs  

Microsoft Academic Search

This paper describes an application of data mining and machine learning to discovering network traffic anomalies in firewall logs. There is a variety of issues and problems that can occur with systems that are protected by firewalls. These systems can be improperly configured, operate unexpected services, or fall victim to intrusion attempts. Firewall logs often generate hundreds of thousands of

Robert Winding; Timothy Wright; Michael Chapple

2006-01-01

121

Log-binomial models: exploring failed convergence  

PubMed Central

Background Relative risk is a summary metric that is commonly used in epidemiological investigations. Increasingly, epidemiologists are using log-binomial models to study the impact of a set of predictor variables on a single binary outcome, as they naturally offer relative risks. However, standard statistical software may report failed convergence when attempting to fit log-binomial models in certain settings. The methods that have been proposed in the literature for dealing with failed convergence use approximate solutions to avoid the issue. This research looks directly at the log-likelihood function for the simplest log-binomial model where failed convergence has been observed, a model with a single linear predictor with three levels. The possible causes of failed convergence are explored and potential solutions are presented for some cases. Results Among the principal causes is a failure of the fitting algorithm to converge despite the log-likelihood function having a single finite maximum. Despite these limitations, log-binomial models are a viable option for epidemiologists wishing to describe the relationship between a set of predictors and a binary outcome where relative risk is the desired summary measure. Conclusions Epidemiologists are encouraged to continue to use log-binomial models and advocate for improvements to the fitting algorithms to promote the widespread use of log-binomial models.

2013-01-01

122

Thermostable Two-Channel Radioactivity Logging Apparatus.  

National Technical Information Service (NTIS)

A thermostable two-channel radioactivity logging (RL) apparatus, designed to operate at temperatures up to 220 exp 0 C and a hydrostatic pressure up to 1200 kgf/cm exp 2, developed and produced for conducting operations by the gamma logging (GL) and neutr...

E. S. Bakhromi M. V. Posikera

1976-01-01

123

Cracking the Code: Web Log Analysis.  

ERIC Educational Resources Information Center

Demonstrates the benefits and problems of using Web log analysis to extract information about the global information customer. The Web logs examined were those of "The Times" and "Sunday Times." Highlights include the measures and metrics; the data and its meaning; and analyses with potential (AEF)

Nicholas, David; Huntington, Paul; Lievesley, Nat; Withey, Richard

1999-01-01

124

Message Logging: Pessimistic, Optimistic, Causal, and Optimal  

Microsoft Academic Search

Message-logging protocols are an integral part of a popular technique for implementing processes that can recover from crash failures. All message-logging protocols require that, when recovery is complete, there be no orphan processes, which are surviving processes whose states are inconsistent with the recovered state of a crashed process. We give a precise specification of the consistency property \\

Lorenzo Alvisi; Keith Marzullo

1998-01-01

125

Message Logging: Pessimistic, Optimistic, and Causal  

Microsoft Academic Search

Message logging protocols are an integral part of a technique for implementing processes that canrecover from crash failures. All message logging protocols require that, when recovery is complete,there be no orphan processes, which are surviving processes whose states are inconsistent with therecovered state of a crashed process. We give a precise specification of the consistency property "noorphan processes". From this

Lorenzo Alvisi; Keith Marzullot

1995-01-01

126

The Computer as a Log of Wood.  

ERIC Educational Resources Information Center

Because a teacher and a student were seated on either end of a log (facing each other), there was direct, eye-to-eye, one-on-one communication. If properly used, computers can take the place of the log, establishing the eye-to-eye, one-on-one, two-way communication. Advantages occur because computers are interactive, individualized, modular, and…

Coad, Peter; Coad, Raylene

1985-01-01

127

Deriving Software Usage Patterns from Log Files  

Microsoft Academic Search

Log files (discrete recordings of user actions during software use) offer the ability to collect human-computer interaction data on a number of users, over time, while the users are engaged in typical tasks in typical environments. The disadvantage of log files is the lack of automated methods for analyzing the volumes of data in a meaningful way. This paper presents

Mark Guzdial

1993-01-01

128

Chernoff's density is log-concave  

PubMed Central

We show that the density of Z = argmax{W (t) ? t2}, sometimes known as Chernoff’s density, is log-concave. We conjecture that Chernoff’s density is strongly log-concave or “super-Gaussian”, and provide evidence in support of the conjecture.

BALABDAOUI, FADOUA; WELLNER, JON A.

2014-01-01

129

Discover Presidential Log Cabins. Teacher's Discussion Guide.  

ERIC Educational Resources Information Center

Discover Presidential Log Cabins is a set of materials designed to help educate 6-8 grade students about the significance of three log cabin sites occupied by George Washington, Ulysses Grant, Abraham Lincoln, and Theodore Roosevelt. This teacher's discussion guide is intended for use as part of a larger, comprehensive social studies program, and…

National Park Service (Dept. of Interior), Washington, DC.

130

Memoirs of Togetherness from Audio Logs  

Microsoft Academic Search

In this paper, we propose a new concept how tempo-social information about moments of togetherness within a social group of people can be retrieved in the palm of the hand from social context. The social context is digitised by audio logging of the same user centric device such as mobile phone. Being asynchronously driven it allows automatically logging social events

Danil Korchagin

2009-01-01

131

Formation Productivity Evaluation From Temperature Logs  

Microsoft Academic Search

A brief review is presented of the methods of quantitative evaluation of borehole temperature logs as applied to gas flow measurements. A method for evaluation of the formation productivity is introduced, making use of a temperature log of the flowing gas well, the reservoir temperature and pressure, and the Joule-Thomson expansion temperature of the gas. A method is discussed for

J. M. Bird; N. Frost

1966-01-01

132

When do logs move in rivers?  

NASA Astrophysics Data System (ADS)

Large woody debris is an integral component of forested, fluvial systems throughout the world, yet we know little about hydraulic thresholds for movement and transport of logs. We developed theoretical models of entrainment and performed flume experiments to examine thresholds for wood movement in streams. Both the model and the experiments indicate that log entrainment is primarily a function of the piece angle relative to flow direction, whether or not the log had a rootwad, the density of the log, and the piece diameter. Stability increased if the pieces had rootwads or were rotated parallel to flow. Although previously reported as the most important factor in piece stability, piece length did not significantly affect the threshold of movement in our experiments or our physically based model, for logs shorter than channel width. These physically based models offer a first-order approach to evaluating the stability of either naturally derived woody debris or material deliberately introduced to streams for various management objectives.

Braudrick, Christian A.; Grant, Gordon E.

2000-02-01

133

The velocity-deviation log: A tool to predict pore type and permeability trends in carbonate drill holes from sonic and porosity or density logs  

SciTech Connect

The velocity-deviation log, which is calculated by combining the sonic log with the neutron-porosity or density log, provides a tool to obtain downhole information on the predominant pore type in carbonates. The log can be used to trace the downhole distribution of diagenetic processes and to estimate trends in permeability. Laboratory measurements on over 300 discrete carbonate samples reveal that sonic velocity is a function not only of total porosity, but also of the predominant pore type. In general, there is an inverse porosity-velocity correlation, but significant deviations occur from this relationship for certain pore types. Frame-forming pore types, such as moldic or intrafossil porosity, result in significantly higher velocity values at equal total porosities than do pore types that are not embedded in a rigid rock frame, such as interparticle porosity or microporosity. The results of the laboratory measurements can be applied to expand interpretations of standard wireline-log data, as shown in this study on two drill holes through Neogene carbonates from the Great Bahama Bank. The velocity-deviation log is calculated by first converting porosity-log data to a synthetic velocity log using a time-average equation. The difference between the real sonic log and the synthetic sonic log can then be plotted as a velocity-deviation log. Because deviations are the result of the variability of velocity at a certain porosity, the deviation log reflects the different rock-physical signatures of the different pore types. Positive velocity deviations mark zones where velocity is higher than expected from the porosity values, such as zones where frame-forming pore types dominate. Zero deviations show intervals where the rock lacks a rigid frame, such as in carbonates with high interparticle porosity or microporosity. Negative deviations mark zones in which sonic log velocities are unusually low, caused, for instance, by a cavernous bore-hole wall, fracturing, or possibly by a high content of free gas. By tracing the velocity deviations continuously downhole, one can identify diagenetic zones that are characterized by these different pore types. In addition, this method can be used to observe permeability trends because pore types influence the permeability of the rock.

Anselmetti, F.S.; Eberli, G.P. [Univ. of Miami, FL (United States). Comparative Sedimentology Lab.

1999-03-01

134

Sedimentological analysis using geophysical well logs  

SciTech Connect

The application of geophysical well logs in sedimentology and stratigraphic prospecting holds great promise in solving a number of geological problems. A suite of logs provides data on a wide range of rock properties: vertical and lateral variation of resistivity, natural polarization, natural and induced radioactivity, shear strength, and acoustic properties. Each of these properties is controlled by the depositional environment of the sediments and their later diagenesis. The attention of geologists and geophysicists is drawn to new techniques in the interpretation of geophysical well logs for exploration, appraisal, and development of oil and gas fields. The relationship between geophysical logs and depositional environments is explored. Bulk composition, rock structure, and texture and facies variation can be quantified by electric log parameters. Also, the possibility of using logs to demonstrate long- and short-period sedimentary cycles is demonstrated. Methods of sedimentological analysis using geophysical well logs are demonstrated. The importance of a genetic approach in the interpretation of geological sequences and paleogeological reconstructions is emphasized using examples taken from oil and gas prospecting operations in the Ukraine.

Izotova, T.S. (Ukrainian State Geological Research Institute, Kiev (Ukraine))

1993-09-01

135

Recognizing Patterns In Log-Polar Coordinates  

NASA Technical Reports Server (NTRS)

Log-Hough transform is basis of improved method for recognition of patterns - particularly, straight lines - in noisy images. Takes advantage of rotational and scale invariance of mapping from Cartesian to log-polar coordinates, and offers economy of representation and computation. Unification of iconic and Hough domains simplifies computations in recognition and eliminates erroneous quantization of slopes attributable to finite spacing of Cartesian coordinate grid of classical Hough transform. Equally efficient recognizing curves. Log-Hough transform more amenable to massively parallel computing architectures than traditional Cartesian Hough transform. "In-place" nature makes it possible to apply local pixel-neighborhood processing.

Weiman, Carl F. R.

1992-01-01

136

Nonblocking and orphan free message logging protocols  

NASA Technical Reports Server (NTRS)

Currently existing message logging protocols demonstrate a classic pessimistic vs. optimistic tradeoff. We show that the optimistic-pessimistic tradeoff is not inherent to the problem of message logging. We construct a message-logging protocol that has the positive features of both optimistic and pessimistic protocol: our protocol prevents orphans and allows simple failure recovery; however, it requires no blocking in failure-free runs. Furthermore, this protocol does not introduce any additional message overhead as compared to one implemented for a system in which messages may be lost but processes do not crash.

Alvisi, Lorenzo; Hoppe, Bruce; Marzullo, Keith

1992-01-01

137

Web Logs in the English Classroom: More Than Just Chat.  

ERIC Educational Resources Information Center

Details the use and appeal of Web logs to enhance classroom discussion and allow for outside involvement in the classroom. Defines a Web log, addresses discussing literature in a Web log, and describes the author's first attempts at using Web-log technology. Presents considerations for using Web logs as part of classroom instruction. (SG)

Richardson, Will

2003-01-01

138

Formation mechanical properties and the sonic log  

SciTech Connect

A program is presented that calculates the mechanical properties of reservoir rocks from sonic logs. The program was written in Microsoft BASIC and the source code for MS-DOS, Apple Macintosh, and Amiga personal computers is given.

Elphick, R.Y.

1988-11-01

139

The Moments of Log-ACD Models  

Microsoft Academic Search

We provide existence conditions and analytical expressions of the moments of Log-ACD models. We focus on the dispersion index and the autocorrelation function and compare them with those of ACD and SCD models.

Luc Bauwens; Pierre Giot

140

Recover it yourself with user logging  

SciTech Connect

IMAGE logging is a good product that has proved to be an effective and accurate way to save interactive transactions for recovery and audit purposes. There is one shortcoming with the product in that it only logs transactions within the IMAGE domain. Some applications require that KSAM and MPE files be updated in an on-line system. How can these files be recovered. One answer is to use a recoverable program structure that not only posts the interactive transactions, but recovers them as well. The user logging facility is used to store the successful transactions to either tape or disc. This paper will discuss the recoverable program structure and the user logging subsystem.

Weir, D.

1984-01-01

141

High resolution gamma spectroscopy well logging system.  

National Technical Information Service (NTIS)

A Gamma Spectroscopy Logging System (GSLS) has been developed to study sub-surface radionuclide contamination. The absolute counting efficiencies of the GSLS detectors were determined using cylindrical reference sources. More complex borehole geometries w...

J. R. Giles K. J. Dooley

1997-01-01

142

Optimal message log reclamation for uncoordinated checkpointing  

NASA Technical Reports Server (NTRS)

Uncoordinated checkpointing for message-passing systems allows maximum process autonomy and general nondeterministic execution, but suffers from potential domino effect and the large space overhead for maintaining checkpoints and message logs. Traditionally, it has been assumed that only obsolete checkpoints and message logs before the global recovery line can be garbage-collected. Recently, an approach to identifying all garbage checkpoints based on recovery line transformation and decomposition has been developed. We show in this paper that the same approach can be applied to the problem of identifying all garbage message logs for systems requiring message logging to record in-transit messages. Communication trace-driven simulation for several parallel programs is used to evaluate the proposed algorithm.

Wang, Yi-Min; Fuchs, W. K.

1994-01-01

143

RIAPROG: logit-log radioimmunoassay data processing  

SciTech Connect

This document provides the users guide and program listings for the 1980 version of RIAPROG. RIAPROG is a program for weighted least squares linear regression using the logit-log model for analysis of RIA results.

Faden, V.B.; Huston, J.C. Jr.; Munson, P.J.; Rodbard, D.

1980-03-01

144

Using Work Sampling to Analyze Logging Operations.  

National Technical Information Service (NTIS)

The report discusses the advantages and disadvantages of various time study methods for determining efficiency and productivity in logging. The work sampling method is compared with the continuous time-study method; gives the feasibility, capability, and ...

E. S. Miyata H. M. Stienhib S. A. Winsauer

1981-01-01

145

CMLOG: A common message logging system  

SciTech Connect

The Common Message Logging (CMLOG) system is an object-oriented and distributed system that not only allows applications and systems to log data (messages) of any type into a centralized database but also lets applications view incoming messages in real-time or retrieve stored data from the database according to selection rules. It consists of a concurrent Unix server that handles incoming logging or searching messages, a Motif browser that can view incoming messages in real-time or display stored data in the database, a client daemon that buffers and sends logging messages to the server, and libraries that can be used by applications to send data to or retrieve data from the database via the server. This paper presents the design and implementation of the CMLOG system meanwhile it will also address the issue of integration of CMLOG into existing control systems.

Chen, J.; Akers, W.; Bickley, M.; Wu, D.; Watson, W. III [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States). Control Software Group

1997-12-01

146

Optimal Message Log Reclamation for Uncoordinated Checkpointing.  

National Technical Information Service (NTIS)

Uncoordinated checkpointing for message-passing systems allows maximum process autonomy and general nondeterministic execution, but suffers from potential domino effect and the large space overhead for maintaining checkpoints and message logs. Traditional...

Y. M. Wang W. K. Fuchs

1994-01-01

147

29 CFR 1910.266 - Logging operations.  

Code of Federal Regulations, 2010 CFR

...but are not limited to, tractors, skidders, front-end loaders, scrapers...not be exceeded. (iv) To maintain stability, the machine must be operated within...Protective structures. (i) Each tractor, skidder, swing yarder, log stacker,...

2010-07-01

148

29 CFR 1910.266 - Logging operations.  

Code of Federal Regulations, 2010 CFR

...but are not limited to, tractors, skidders, front-end loaders, scrapers...not be exceeded. (iv) To maintain stability, the machine must be operated within...Protective structures. (i) Each tractor, skidder, swing yarder, log stacker,...

2009-07-01

149

New Probe for gamma Spectrometric Logging.  

National Technical Information Service (NTIS)

The new spectrometric probe contains an analog to digital converter (ADG). The advantage of this device are as follows. All the winches used for logging are equipped with cables containing electrical conductors. In consequence the attenuation of the cable...

P. Dumesnil

1983-01-01

150

Heterogeneity of wood decay classes within hardwood logs 1 This paper is Scientific Contribution No. 1768 of the Storrs Agricultural Experiment Station, CT. 1  

Microsoft Academic Search

As forest floor coarse woody debris (CWD) decays, it changes from solid wood to material without a recognizable origin. Decaying logs provide a progression of woody habitat substrates that contribute to the diversity of species and ecological processes in the forest. For studies of the habitat values of logs, decaying logs typically are assigned to one of the five classes

Charlotte Pyle; Michelle M. Brown

1999-01-01

151

Well logging evaporative thermal protection system  

SciTech Connect

An evaporative thermal protection system for use in hostile environment well logging applications, the system including a downhole thermal protection cartridge disposed within a well logging sonde or tool to keep a payload such as sensors and support electronics cool, the cartridge carrying either an active evaporative system for refrigeration or a passive evaporative system, both exhausting to the surface through an armored flexible fluidic communication mechanical cable.

Lamers, M.D.; Martelli, V.P.

1981-02-03

152

Eccentricity Compensator for Log-Polar Sensor  

Microsoft Academic Search

This paper aims at acquiring robust rotation, scale, and translation-invariant feature from a space-variant image by a fovea sensor. A proposed model of eccentricity compensator corrects deformation that occurs in a log-polar image when the fovea sensor is not centered at a target, that is, when eccentricity exists. An image simulator in discrete space remaps a compensated log-polar image using

Sota Shimizu; Joel W. Burdick

2007-01-01

153

DOE/Simplec magnetic susceptibility logging system  

SciTech Connect

A magnetic susceptibility logging system has been developed which is relatively stable under normal field logging conditions and which produces logs that accurately represent in situ variations in magnetic susceptibility. However, both field and laboratory tests indicate the need for further improvement of temperature stabilization and bridge compensation; a new generation system designed by Simplec may fill that need. A cubic granite block with a magnetic susceptibility of 385 ..mu..CGS is designated as the primary calibration standard and is available for public use at the DOE facility in Grand Junction, Colorado. Models are also available for characterization of magnetic susceptibility systems. These include models to provide borehole size correction factors, thin layer interpretation parameters, reproducibility limits, longitudinal resolution, and radius of investigation. The DOE/Simplec system has a 99-percent radius of investigation, approximately equal to the coil length (15 inches), and a 99-percent thickness of investigation, approximately equal to two coil lengths. The true magnetic susceptibility and thickness of isolated layers less than two coil lengths in thickness can be obtained through use of parameters measured from their log responses. Field tests show that the system has a reproducibility of at least 5 ..mu..CGS and that logging at 25 ft/min is a good compromise between speed of operation and keeping the probe on the sidewall. Comparison of log and core magnetic susceptibility measurements confirms the fact that the logging system samples a rather large volume and that interpretive aids are necessary to unfold the true variation of magnetic susceptibility with depth. Finally, logs from known uranium-favorable environments show that magnetic susceptibility measurements can give an indication of the degree of geochemical alteration, which is one of the uranium-favorable haloes sought by exploration geologists.

Emilia, D.A.; Allen, J.W.; Chessmore, R.B.; Wilson, R.B.

1981-03-01

154

Selective Logging, Fire, and Biomass in Amazonia  

NASA Technical Reports Server (NTRS)

Biomass and rates of disturbance are major factors in determining the net flux of carbon between terrestrial ecosystems and the atmosphere, and neither of them is well known for most of the earth's surface. Satellite data over large areas are beginning to be used systematically to measure rates of two of the most important types of disturbance, deforestation and reforestation, but these are not the only types of disturbance that affect carbon storage. Other examples include selective logging and fire. In northern mid-latitude forests, logging and subsequent regrowth of forests have, in recent decades, contributed more to the net flux of carbon between terrestrial ecosystems and the atmosphere than any other type of land use. In the tropics logging is also becoming increasingly important. According to the FAO/UNEP assessment of tropical forests, about 25% of total area of productive forests have been logged one or more times in the 60-80 years before 1980. The fraction must be considerably greater at present. Thus, deforestation by itself accounts for only a portion of the emissions carbon from land. Furthermore, as rates of deforestation become more accurately measured with satellites, uncertainty in biomass will become the major factor accounting for the remaining uncertainty in estimates of carbon flux. An approach is needed for determining the biomass of terrestrial ecosystems. 3 Selective logging is increasingly important in Amazonia, yet it has not been included in region-wide, satellite-based assessments of land-cover change, in part because it is not as striking as deforestation. Nevertheless, logging affects terrestrial carbon storage both directly and indirectly. Besides the losses of carbon directly associated with selective logging, logging also increases the likelihood of fire.

Houghton, R. A.

1999-01-01

155

Automatically Generating Summary Visualizations from Game Logs  

Microsoft Academic Search

In this paper we describe a system called ViGLS (Visualization of Game Log Summaries) that generates summaries of gameplay sessions from game logs. ViGLS automatically produces visualization of the summarized actions that are extracted based on cognitive models of summarization. ViGLS is implemented using a service- oriented architecture, de-coupling the summarization methods from any particular game engine being used. The

Yun-gyung Cheong; Arnav Jhala; Byung-chull Bae; R. Michael Young

2008-01-01

156

Determination of TDS in Geothermal Systems by Well-Log Analysis  

SciTech Connect

An estimate of t h e chemistry of the fluid within a geothermal reservoir is required to establish the geological source and the possible environmental impact of the fluid as well as scaling and corrosion problems which might develop during production. While a detailed analysis of the chemical composition of a geothermal fluid can only be obtained from a water sample, an estimate of the total dissolved solids (TDS) in equivalent sodium chloride (NaCl) concentration can be obtained from well logs. TDS can also be useful in geological correlation between wells. TDS can be determined directly from a pulsed neutron log and a porosity log, (if the type of formation is known), or from the water resistivity, R{sub w}, and the temperature, T. Three approaches are used to find R{sub w}, and thus TDS. The first method uses a dual induction focused log and information from the log heading. Next, is found by employing an electrical log and a porosity log. The last approach utilizes the spontaneous potential log and header data. Examples are provided to illustrate the techniques described which utilize calculated values of R{sub w} to determine TDS.

Brown, Susan L.; Gobran, Brian D.; Sanyal, Subir K.

1980-12-16

157

5. Log calving barn. Detail of wall corner showing half ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. Log calving barn. Detail of wall corner showing half dovetail notching on hand-hewn logs. - William & Lucina Bowe Ranch, Log Calving Barn, 230 feet south-southwest of House, Melrose, Silver Bow County, MT

158

Geothermal Logging. Part 1: An Introduction to Techniques and Interpretation.  

National Technical Information Service (NTIS)

The purpose of geophysical logging in geothermal investigation is described, and objectives, operations and interpretations in petroleum and geothermal logging are compared. Logging parameters in geothermal investigations are listed and the principles and...

V. Stefansson B. Steingrimsson

1980-01-01

159

59 FR- Logging Operations; Final Rule DEPARTMENT OF LABOR  

Federal Register 2010, 2011, 2012, 2013

...chips, etc.). Logging consists of felling trees (usually by chain saws), removing the limbs...branches (limbing), and cutting or splitting the trees into manageable logs (bucking). Trees and logs are then moved (yarding) to...

1994-10-12

160

55. VIEW OF STEAMOPERATED LOG HOIST TO PUT IN COMING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

55. VIEW OF STEAM-OPERATED LOG HOIST TO PUT IN COMING LOGS INTO RALPH HULL LUMBER CO. LOG POND. PHOTOGRAPHER: UNKNOWN. DATE: 1942. COURTESY OF RALPH HULL. - Hull-Oakes Lumber Company, 23837 Dawson Road, Monroe, Benton County, OR

161

Utilization of Electrical Impedance Tomography to Detect Internal Anomalies in Southern Pine Logs  

NASA Astrophysics Data System (ADS)

A large body of research has shown that knowledge of internal defect location in logs prior to sawing has the potential to significantly increase lumber value yield. This paper describes a relatively low-capital log scanning technique based on Electrical Impedance Tomography (EIT) to image anomalies interior to sawlogs. Static testing results showed that knots, juvenile and compression wood internal to logs can be detected. Although resolution is lower than that of CT and NMR technologies, the low cost of this EIT application should render it competitive.

Steele, Philip; Cooper, Jerome

2006-03-01

162

The Block Relevance (BR) analysis supports the dominating effect of solutes hydrogen bond acidity on ?logP(oct-tol).  

PubMed

The role of hydrogen bond acidity, i.e., the ability of chemicals to act as hydrogen bond donors (HBD), is a crucial element in pharmaceutical sciences and medicinal chemistry. It has been shown that the difference between logP values (?logP) obtained in two different biphasic systems is informative of the solutes HBD properties and thus useful in the prediction of drugs human fate. In this study, we collected from literature more than 200 experimental logPtol (the logarithm of the partition coefficient P in the toluene/water system) values along with their corresponding logPoct (the logarithm of the partition coefficient P in the octanol/water system) values. The dataset was processed using a purposely-built in-house software to remove molecules that are potentially able to form IMHBs. On the remaining structures the ?logPoct-tol (=logPoct - logPtol) have been calculated and correlated with 82 VolSurf+descriptors through a PLS model. Finally the Block Relevance (BR) analysis has been used to group the descriptors in six easy-to-interpret blocks and to show graphically the relevance of a certain block in the PLS model. BR analysis showed that the hydrogen bond donor (HBD) properties of the solutes mainly govern ?logPoct-tol. This supports the use of ?logPoct-tol to estimate HBD properties of solutes and its role in the intramolecular hydrogen bonding (IMHB) interpretation scheme recently reported in the literature. PMID:24355253

Ermondi, Giuseppe; Visconti, Alessia; Esposito, Roberto; Caron, Giulia

2014-03-12

163

Partition characteristics of polycyclic aromatic hydrocarbons on soils and sediments  

USGS Publications Warehouse

The partition behavior was determined for three polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene, phenanthrene, and pyrene, from water to a range of soil and sediment samples. The measured partition coefficients of the individual PAHs between soil/sediment organic matter (SOM) and water (i.e., K(oc) values) are relatively invariant either for the 'clean' (uncontaminated) soils or for the clean sediments; however, the mean K(oc) values on the sediments are about twice the values on the soils. This disparity is similar to the earlier observation for other nonpolar solutes and reflects the compositional differences between soil and sediment organic matters. No significant differences in K(oc) are observed between a clean coastal marine sediment and freshwater sediments. The coastal sediments that are significantly impacted by organic contaminants exhibit higher K(oc) values. At given K(ow) values (octanol-water), the PAHs exhibit much higher K(oc) values than other relatively nonpolar solutes (e.g., chlorinated hydrocarbons). This effect is shown to result from the enhanced partition of PAHs to SOM rather than from lower K(ow) values of PAHs at given supercooled liquid solute solubilities in water. The enhanced partition of PAHs over other nonpolar solutes in SOM provides an account of the markedly different correlations between log K(oc) and log K(ow) for PAHs and for other nonpolar solutes. The improved partition of PAHs in SOM stems apparently from the enhanced compatibility of their cohesive energy densities with those of the aromatic components in SOM. The approximate aromatic fraction in soil/sediment organic matter has been assessed by solid-state 13C-NMR spectroscopy.The partition behavior was determined for three polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene, phenanthrene, and pyrene, from water to a range of soil and sediment samples. The measured partition coefficients of the individual PAHs between soil/sediment organic matter (SOM) and water (i.e., Koc values) are relatively invariant either for the `clean' (uncontaminated) soils or for the clean sediments; however, the mean Koc values on the sediments are about twice the values on the soils. This disparity is similar to the earlier observation for other nonpolar solutes and reflects the compositional differences between soil and sediment organic matters. No significant differences in Koc are observed between a clean coastal marine sediment and freshwater sediments. The coastal sediments that are significantly impacted by organic contaminants exhibit higher Koc values. At given Kow values (octanol-water), the PAHs exhibit much higher Koc values than other relatively nonpolar solutes (e.g., chlorinated hydrocarbons). This effect is shown to result from the enhanced partition of PAHs to SOM rather than from lower Kow values of PAHs at given supercooled liquid solute solubilities in water. The enhanced partition of PAHs over other nonpolar solutes in SOM provides an account of the markedly different correlations between log Koc and log Kow for PAHs and for other nonpolar solutes. The improved partition of PAHs in SOM stems apparently from the enhanced compatibility of their cohesive energy densities with those of the aromatic components in SOM. The approximate aromatic fraction in soil/sediment organic matter has been assessed by solid-state 13C-NMR spectroscopy.

Chiou, C. T.; Mcgroddy, S. E.; Kile, D. E.

1998-01-01

164

Well log evaluation of gas hydrate saturations  

USGS Publications Warehouse

The amount of gas sequestered in gas hydrates is probably enormous, but estimates are highly speculative due to the lack of previous quantitative studies. Gas volumes that may be attributed to a gas hydrate accumulation within a given geologic setting are dependent on a number of reservoir parameters; one of which, gas-hydrate saturation, can be assessed with data obtained from downhole well logging devices. The primary objective of this study was to develop quantitative well-log evaluation techniques which will permit the calculation of gas-hydrate saturations in gas-hydrate-bearing sedimentary units. The "standard" and "quick look" Archie relations (resistivity log data) yielded accurate gas-hydrate and free-gas saturations within all of the gas hydrate accumulations assessed in the field verification phase of the study. Compressional wave acoustic log data have been used along with the Timur, modified Wood, and the Lee weighted average acoustic equations to calculate accurate gas-hydrate saturations in all of the gas hydrate accumulations assessed in this study. The well log derived gas-hydrate saturations calculated in the field verification phase of this study, which range from as low as 2% to as high as 97%, confirm that gas hydrates represent a potentially important source of natural gas.

Collett, T. S.

1998-01-01

165

Well log evaluation of gas hydrate saturations  

USGS Publications Warehouse

The amount of gas sequestered in gas hydrates is probably enormous, but estimates are highly speculative due to the lack of previous quantitative studies. Gas volumes that may be attributed to a gas hydrate accumulation within a given geologic setting are dependent on a number of reservoir parameters; one of which, gas-hydrate saturation, can be assessed with data obtained from downhole well logging devices. The primary objective of this study was to develop quantitative well-log evaluation techniques which will permit the calculation of gas-hydrate saturations in gas-hydrate-bearing sedimentary units. The `standard' and `quick look' Archie relations (resistivity log data) yielded accurate gas-hydrate and free-gas saturations within all of the gas hydrate accumulations assessed in the field verification phase of the study. Compressional wave acoustic log data have been used along with the Timur, modified Wood, and the Lee weighted average acoustic equations to calculate accurate gas-hydrate saturations in this study. The well log derived gas-hydrate saturations calculated in the field verification phase of this study, which range from as low as 2% to as high as 97%, confirm that gas hydrates represent a potentially important source of natural gas.

Collett, Timothy, S.

1998-01-01

166

Scientific LogAnalyzer: A Web-based tool for analyses of server log files in psychological research  

Microsoft Academic Search

Scientific LogAnalyzer is a platform-independent interactive Web service for the analysis of log files. Scientific LogAnalyzer\\u000a offers several features not available in other log file analysis tools—for example, organizational criteria and computational\\u000a algorithms suited to aid behavioral and social scientists. Scientific LogAnalyzer is highly flexible on the input side (unlimited\\u000a types of log file formats), while strictly keeping a scientific

Ulf-Dietrich Reips; Stefan Stieger

2004-01-01

167

A Robust GM-Estimator for the Automated Detection of External Defects on Barked Hardwood Logs and Stems  

Microsoft Academic Search

The ability to detect defects on hardwood trees and logs holds great promise for the hardwood forest products industry. At every stage of wood processing, there is a potential for improving value and recovery with knowledge of the location, size, shape, and type of log defects. This paper deals with a new method that processes hardwood laser-scanned surface data for

Liya Thomas; Lamine Mili

2007-01-01

168

Automatic grading of Scots pine ( Pinus sylvestris L.) sawlogs using an industrial X-ray log scanner  

Microsoft Academic Search

The successful running of a sawmill is dependent on its ability to achieve the highest possible value recovery from the sawlogs, i.e. to optimize the use of the raw material. Such optimization requires information about the properties of every log. One method of measuring these properties is to use an X-ray log scanner. The objective of the present study was

Johan Oja; Lars Wallbäcks; Stig Grundberg; Erik Hägerdal; Anders Grönlund

2003-01-01

169

Spreadsheet log analysis in subsurface geology  

USGS Publications Warehouse

Most of the direct knowledge of the geology of the subsurface is gained from the examination of core and drill-cuttings recovered from boreholes drilled by the petroleum and water industries. Wireline logs run in these same boreholes generally have been restricted to tasks of lithostratigraphic correlation and thee location of hydrocarbon pay zones. However, the range of petrophysical measurements has expanded markedly in recent years, so that log traces now can be transformed to estimates of rock composition. Increasingly, logs are available in a digital format that can be read easily by a desktop computer and processed by simple spreadsheet software methods. Taken together, these developments offer accessible tools for new insights into subsurface geology that complement the traditional, but limited, sources of core and cutting observations.

Doveton, J. H.

2000-01-01

170

Discovering Process Models from Unlabelled Event Logs  

NASA Astrophysics Data System (ADS)

Existing process mining techniques are able to discover process models from event logs where each event is known to have been produced by a given process instance. In this paper we remove this restriction and address the problem of discovering the process model when the event log is provided as an unlabelled stream of events. Using a probabilistic approach, it is possible to estimate the model by means of an iterative Expectaction-Maximization procedure. The same procedure can be used to find the case id in unlabelled event logs. A series of experiments show how the proposed technique performs under varying conditions and in the presence of certain workflow patterns. Results are presented for a running example based on a technical support process.

Ferreira, Diogo R.; Gillblad, Daniel

171

Unconventional neutron sources for oil well logging  

NASA Astrophysics Data System (ADS)

Americium-Beryllium (AmBe) radiological neutron sources have been widely used in the petroleum industry for well logging purposes. There is strong desire on the part of various governmental and regulatory bodies to find alternate sources due to the high activity and small size of AmBe sources. Other neutron sources are available, both radiological (252Cf) and electronic accelerator driven (D-D and D-T). All of these, however, have substantially different neutron energy spectra from AmBe and thus cause significantly different responses in well logging tools. We report on simulations performed using unconventional sources and techniques to attempt to better replicate the porosity and carbon/oxygen ratio responses a well logging tool would see from AmBe neutrons. The AmBe response of these two types of tools is compared to the response from 252Cf, D-D, D-T, filtered D-T, and T-T sources.

Frankle, C. M.; Dale, G. E.

2013-09-01

172

LogSafe and Smart: Minnesota OSHA's LogSafe Program Takes Root.  

ERIC Educational Resources Information Center

Logging is now the most dangerous U.S. occupation. The Occupational Safety and Health Administration (OSHA) developed specialized safety training for the logging industry but has been challenged to reach small operators. An OSHA-approved state program in Minnesota provides annual safety seminars to about two-thirds of the state's full-time…

Honerman, James

1999-01-01

173

MAIL LOG, program summary and specifications  

NASA Technical Reports Server (NTRS)

The summary and specifications to obtain the software package, MAIL LOG, developed for the Scout Project Automatic Data System, SPADS are provided. The MAIL LOG program has four modes of operation: (1) input - putting new records into the data base; (2) revise - changing or modifying existing records in the data base; (3) search - finding special records existing in the data base; and (4) archive - store or put away existing records in the data base. The output includes special printouts of records in the data base and results from the input and search modes.

Harris, D. K.

1979-01-01

174

Phenanthrene sorption by aliphatic-rich natural organic matter.  

PubMed

Contaminant sorption, an important process that may limit bioavailability, hinder remediation, encourage environmental persistence, and control mobility in the environment, has been the focus of numerous studies. Despite these efforts, the fundamental understanding of sorptive processes in soil and sedimentary environments has not been resolved. For instance, many have suggested that contaminants, such as polycyclic aromatic hydrocarbons (PAHs), solely interact with aromatic domains of organic matter. Until now, studies have neglected the aliphatic components that are known to be a recalcitrant and significant part of soil and sedimentary organic matter (SOM). In this investigation, the sorption of phenanthrene to several aliphatic-rich SOM samples was measured. The samples included the following: SOM precursors (algae, degraded algae, cellulose, collagen, cuticle, and lignin), two kerogen samples, and a highly aromatic humic acid. All samples were characterized by cross polarization magic angle spinning carbon-13 (CPMAS 13C) NMR and carbon, hydrogen, and nitrogen analysis. Batch experiments demonstrated that the highest organic carbon normalized sorption coefficients (Koc values) were obtained with the Pula kerogen sample (log Koc = 4.88) that only contains 6.5% aromatic carbon. Other aliphatic-rich samples, namely the Green River kerogen, degraded algae, and collagen samples produced comparable log Koc values (4.64, 4.66, and 4.72, respectively) to that of the highly aromatic humic acid (log Koc = 4.67). Phenanthrene uptake was the least for cellulose and lignin, two major soil components. A comparison of phenanthrene Koc values and paraffinic carbon content revealed a positive correlation (Koc = 798 +/- 96.1 * paraffinic carbon (%), r2 = 0.56) and indicates that amorphous polymethylene carbon is an important consideration in phenanthrene sorption. This study establishes that aliphatic SOM domains have a strong affinity for phenanthrene and likely, other PAHs. Therefore, aliphatic structures, that are an important component of SOM, require more attention in the examination of sorption processes in terrestrial and sedimentary environments. PMID:12026977

Salloum, Myrna J; Chefetz, Benny; Hatcher, Patrick G

2002-05-01

175

Estimating xenobiotic half-lives in humans from rat data: influence of log P.  

PubMed Central

The nature of empirical allometric expressions relating dispositional and kinetic parameters for a given xenobiotic across multiple mammalian species is well known. It has also been demonstrated that a simple allometric relationship may be used to predict kinetic parameters for humans based merely on data for multiple xenobiotics from rats. We decided to explore reasons for the variance in the data arising from the latter method. We were particularly interested in learning whether any physicochemical characteristics of xenobiotics might account for outlying data points (i.e., poor prediction of human half-life from rat half-life). We have explored the influence of lipid solubility as reflected by a xenobiotic's log P value because adipose tissue comprises a significantly larger percentage of total body weight in humans than in rats. We used half-life data from the literature for 127 xenobiotics. A data subset of 102 xenobiotics for which we were able to find estimates of log P values, including several with extremely large log P values, was also analyzed. First and second order models, including and excluding log P, were compared. The simplest of these models can be recast as the familiar allometric relationship having the form Y = a(Xb). The remaining models can be seen as extensions of this relationship. Our results suggest that incorporation of log P into the prediction of xenobiotic half-life in humans from rat half-life data is important only for xenobiotics with extremely large log P values such as dioxins and polychlorinated biphenyls. Moreover, a second order model in logarithm of rat half-life accommodates all data points very well, without specifically accounting for log P values. Images Figure 1. Figure 2. Figure 3. A Figure 3. B Figure 3. C Figure 3. D Figure 4.

Sarver, J G; White, D; Erhardt, P; Bachmann, K

1997-01-01

176

Log-Linear Analysis for an AxBxC Contingency Table  

NSDL National Science Digital Library

Richard Lowry of Vassar College has created a log-linear analysis which is a version of chi-square analysis. The relevant values are calculated by way of weighted natural logarithms. This page will calculate several values of G^2. This is a nice interactive resource which allows the user to manipulate the data to better understand the statistical methods.

Lowry, Richard

2009-01-14

177

32 CFR 700.845 - Maintenance of logs.  

Code of Federal Regulations, 2013 CFR

...Maintenance of logs. (a) A deck log and an engineering log shall be maintained by each ship in commission, and by such other ships...preparation of the deck and engineering logs and adjunct records. (d) In the case of a ship or craft...

2013-07-01

178

Using Web Server Logs in Evaluating Instructional Web Sites.  

ERIC Educational Resources Information Center

Web server logs contain a great deal of information about who uses a Web site and how they use it. This article discusses the analysis of Web logs for instructional Web sites; reviews the data stored in most Web server logs; demonstrates what further information can be gleaned from the logs; and discusses analyzing that information for the…

Ingram, Albert L.

2000-01-01

179

1. GENERAL VIEW OF LOG POND AND BOOM FOR UNLOADING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. GENERAL VIEW OF LOG POND AND BOOM FOR UNLOADING CEDAR LOGS FROM TRUCKS AT LOG DUMP, ADJACENT TO MILL; TRUCKS FORMERLY USED TRIP STAKES, THOUGH FOR SAFER HANDLING OF LOGS WELDED STAKES ARE NOW REQUIRED; AS A RESULT LOADING IS NOW DONE WITH A CRANE - Lester Shingle Mill, 1602 North Eighteenth Street, Sweet Home, Linn County, OR

180

Testing using Log File Analysis: Tools, Methods, and Issues  

Microsoft Academic Search

Large software systems often keep log files of events. Such log files can be analyzed to check whether a run of a program reveals faults in the system. We discuss how such log files can be used in software testing. We present a frame- work for automatically analyzing log files, and describe a language for specifying analyzer programs and an

James H. Andrews

1998-01-01

181

Understanding MWD data acquisition can improve log interpretation  

Microsoft Academic Search

By understanding how measurement-while-drilling (MWD) tools acquire data and how the data are processed, engineers and geologists can better interpret MWD logs. Wire line and MWD log data sometimes do not precisely match. If a discrepancy occurs between MWD and wire line logs run across the same interval, many log interpreters will condemn the MWD data. Recognizing the differences and

1994-01-01

182

LOG DWELLINGS IN CANADIAN FOLK ARCHITECTURE  

Microsoft Academic Search

Log dwellings provided shelter for aboriginal and European settlers in Canada. There may have been some borrowing from Indian sources by early French-speaking settlers, but most forms seem to have been imported from the home country, with subsequent Canadian development. Expulsion of the Acadians obliterated early forms in Maritime Canada. Stone characterizes most of the surviving early forms in the

WILLIAM C. WONDERS

1979-01-01

183

The moments of Log-ACD models  

Microsoft Academic Search

We provide existence conditions and analytical expressions of the moments of logarithmic autoregressive conditional duration (Log-ACD) models. We focus on the dispersion index and the autocorrelation function and compare them with those of ACD (Engle and Russell 1998) and SCD models. Using duration data for several stocks traded on the New York Stock Exchange, we compare the models in terms

Luc BAUWENS; Fausto GALLI; Pierre GIOT

2003-01-01

184

MAIL LOG, program theory, volume 2  

NASA Technical Reports Server (NTRS)

Information relevant to the MAIL LOG program theory is documented. The L-files for mail correspondence, design information release/report, and the drawing/engineering order are given. In addition, sources for miscellaneous external routines and special support routines are documented along with a glossary of terms.

Harris, D. K.

1979-01-01

185

Electromagnetic logging technique based on borehole radar  

Microsoft Academic Search

An electromagnetic logging technique based on borehole radar is introduced in this paper. The tool consists of one transmitter and two receivers, which can be used to cancel the effect of the antenna characteristics by taking the ratio of two receiver signals. Since receiver signals measured in the time domain can be converted into the frequency domain by Fourier transformation,

Sixin Liu; Motoyuki Sato

2002-01-01

186

Data logging for technical services at CERN  

Microsoft Academic Search

A data-logging system for the technical infrastructure of CERN was developed and has been used for over two years by the Technical Control Room (TCR) and by equipment groups. Hardware and some software are common to the SPS\\/LEP accelerator control system, though some particular features had to be implemented to meet specific requirements of the TCR. One of these requirements

R. Martini; H. Laeger; P. Ninin; E. Pfirsch; P. Sollander

1995-01-01

187

There's Life in Those Dead Logs!  

ERIC Educational Resources Information Center

Although it is unspectacular in appearance, dead wood is one of the most ecologically important resources in forests. Fallen logs, dead standing trees, stumps, and even cavities in live trees fulfill a wide range of roles. Prominent among these is that they provide habitat for many organisms, especially insects. Fourth-grade students at Fox…

Biggs, Devin; Miller, Todd; Hall, Dee

2006-01-01

188

Disturbance during Logging Stimulates Regeneration of KOA.  

National Technical Information Service (NTIS)

The abundance and distribution of Acacia koa regeneration after logging were studied on a 500-acre (202-ha) tract of koa forest heavily infested with Passiflora mollissima vines on the island of Hawaii. Koa seedling density was about three times greater i...

P. G. Scowcroft R. E. Nelson

1976-01-01

189

A First Look at Logging in Gabon  

NSDL National Science Digital Library

This newly released report [.pdf format] from Global Forest Watch (World Resources Institute) takes a first look at Gabon's forestry practices. The report describes how forests are rapidly being conceded to "a handful of logging companies" which export primarily one species of tree to a narrow range of countries.

190

GAMMA-RAY SPECTROSCOPY IN WELL LOGGING  

Microsoft Academic Search

Thermal neutron capture gamma rays have been observed in boreholes ; drilled in shales, sandstones, and limestones. A capsuled source of neutrons and ; a scintillation crystal detector, connected through 5,000 ft of logging cable to ; a transistorized, multichannel, pulse-height analyzer, were used. Resolved peaks ; were identified on the basis of the known energies of expected gamma rays

Richard L. Caldwell; W. F. Baldwin; J. D. Bargainer; J. E. Berry; G. N. Salaita; R. W. Sloan

1963-01-01

191

Natural gamma radiation borehole logging system  

Microsoft Academic Search

A borehole logging system employs a gamma-ray detector for measuring the natural gamma radiation of the earth formations surrounding a borehole. Three energy band selectors, each employing a discriminator and count rate meter, separate the output of the gamma-ray detector into potassium, uranium, and thorium energy band signals. A first operational amplifier determines the difference between the potassium energy band

C. L. Dennis; W. S. Givens; J. B. Hickman

1976-01-01

192

Modelling tropical forests response to logging  

NASA Astrophysics Data System (ADS)

Tropical rainforests are among the most threatened ecosystems by large-scale fragmentation due to human activity such as heavy logging and agricultural clearance. Although, they provide crucial ecosystem goods and services, such as sequestering carbon from the atmosphere, protecting watersheds and conserving biodiversity. In several countries forest resource extraction has experienced a shift from clearcutting to selective logging to maintain a significant forest cover and understock of living biomass. However the knowledge on the short and long-term effects of removing selected species in tropical rainforest are scarce and need to be further investigated. One of the main effects of selective logging on forest dynamics seems to be the local disturbance which involve the invasion of open space by weed, vines and climbers at the expense of the late-successional state cenosis. We present a simple deterministic model that describes the dynamics of tropical rainforest subject to selective logging to understand how and why weeds displace native species. We argue that the selective removal of tallest tropical trees carries out gaps of light that allow weeds, vines and climbers to prevail on native species, inhibiting the possibility of recovery of the original vegetation. Our results show that different regime shifts may occur depending on the type of forest management adopted. This hypothesis is supported by a dataset of trees height and weed/vines cover that we collected from 9 plots located in Central and West Africa both in untouched and managed areas.

Cazzolla Gatti, Roberto; Di Paola, Arianna; Valentini, Riccardo; Paparella, Francesco

2013-04-01

193

Elemental concentration logging with a germanium spectrometer  

SciTech Connect

The German deep-well project is currently drilling a scientific well in northeastern Bavaria at the intersection of the African and Northern European tectonic plates. This well is scheduled to be drilled to a depth of {approximately}10 km to study the geochemical processes involved in the alteration of minerals under high temperature and pressure. As an initial stage in this project, a well was drilled to a depth of 4 km within 200 m of the site selected for the deep well. This well was fully cored and extensively logged with both commercial and experimental logging systems. Cores, as well as cuttings and fluids, were extensively analyzed in a well-site laboratory established specifically for that purpose. One of the experimental logging systems run in the 4-km well was a gamma-ray spectrometer that used a {sup 252}Cf source for delayed activation measurements and a neutron generator that produces 14-MeV neutrons for thermal neutron-capture gamma-ray measurements. There were two primary goals of this project. The first was to confirm the validity of elemental concentration determinations from commercial logging equipment, based on NaI(Tl) detectors, in this crystalline rock environment. The commercial equipment determines the elements: aluminum, silicon, sulfur, calcium, titanium, iron, gadolinium, potassium, thorium, and uranium. The second was to determine additional elemental concentrations that can be used to enhance the geo-chemical studies of the crystalline rock mineralogy.

Peterson, C.A.; Schweitzer, J.S. (Schlumberger-Doll Research Center, Ridgefield, CT (United States)); Draxler, J.K.

1991-11-01

194

On exploring heterogeneities from well logs using the empirical mode decomposition  

NASA Astrophysics Data System (ADS)

In contrast with the traditional analysis approaches, the Empirical Mode Decomposition (EMD) allows to study nonlinear and nonstationary data. Here, this technique is used to perform a scale-based decomposition from Algerian well logs and to investigate heterogeneities of the layers crossed by the wells. First, the well log data are decomposed into intrinsic mode functions (IMFs). Then, the total depth interval is divided into lithological subintervals. For each subinterval, we compute the mean wavenumber (km) of each mode (m). It is shown that the EMD method behaves as an almost dyadic filter bank, and the heterogeneity of each lithological subinterval can be measured using a scaling parameter value computed as the slope of a linear regression of the plot km vs. m in the log-linear graph. It is worth noting that this parameter can be used to describe underground heterogeneities. Keywords: empirical mode decomposition (EMD), well logs, multi-scale.

Gaci, Said; Zaourar, Naima; Hachay, Olga

2014-05-01

195

Nondestructive rule-based defect detection and identification system in CT images of hardwood logs  

NASA Astrophysics Data System (ADS)

This paper is concerned with the detection of internal defects in hardwood logs. Because the commercial value of hardwood lumber is directly related to the quantity, type, and location of defects in the wood, sawing strategies are typically chosen in an attempt to minimize the defects in the resulting boards. Traditionally, the sawyer makes sawing decisions by visually examining the exterior of log and then revising the sawing strategy as more and more of the log's interior is exposed. Significantly better results would be expected if internal defects were known, so that a globally optimum solution could be selected in advance. This paper addresses this problem through the analysis of computed tomography (CT) images of logs, for the purpose of detecting important hardwood defects. In particular, the paper considers defect-dependent postprocessing methods, based on mathematical morphology, that show promising results. .

Sarigul, Erol; Abbott, A. Lynn; Schmoldt, Daniel L.

2001-04-01

196

Determining Earthquake Recurrence Intervals from Trench Logs  

NSDL National Science Digital Library

Trench logs of the San Andreas Fault at Pallett Creek, CA are the data base for a lab or homework assignment that teaches about relative dating, radiometric dating, fault recurrence intervals and the reasons for uncertainty in predicting geologic phenomena. Students are given a trench log that includes several fault strands and dated stratigraphic horizons. They estimate the times of faulting based on bracketing ages of faulted and unfaulted strata. They compile a table with the faulting events from the trench log and additional events recognized in nearby trenches, then calculate maximum, minimum and average earthquake recurrence intervals for the San Andreas Fault in this area. They conclude by making their own prediction for the timing of the next earthquake. While basically an exercise in determining relative ages of geologic horizons and events, this assignment includes radiometric dates, recurrence intervals, and an obvious societal significance that has been well received by students. With minor modifications, this exercise has been used successfully with elementary school students through university undergraduate geology majors. Less experienced students can work in groups, with each group determining the age of a single fault strand; combining the results from different groups and calculating recurrence intervals can then be done as a class activity. University students in an introductory geology course for non-majors can add their data from the trench log to an existing table with other faulting events already provided. The exercise can be made more challenging for advanced students by using logs from several different trenches, requiring students to design the table themselves, and giving students the uncertainties for the radiometric dates rather than simple ages for the strata. Most studentsâat all levelsâare initially frustrated by their inability to determine an exact date of faulting from the available data. They gain a new appreciation for the task of the geoscientist who attempts to relate geologic phenomena to the human, rather than geologic, time scale.

197

Log-periodic route to fractal functions  

NASA Astrophysics Data System (ADS)

Log-periodic oscillations have been found to decorate the usual power-law behavior found to describe the approach to a critical point, when the continuous scale-invariance symmetry is partially broken into a discrete-scale invariance symmetry. For Ising or Potts spins with ferromagnetic interactions on hierarchical systems, the relative magnitude of the log-periodic corrections are usually very small, of order 10-5. In growth processes [diffusion limited aggregation (DLA)], rupture, earthquake, and financial crashes, log-periodic oscillations with amplitudes of the order of 10% have been reported. We suggest a ``technical'' explanation for this 4 order-of-magnitude difference based on the property of the ``regular function'' g(x) embodying the effect of the microscopic degrees of freedom summed over in a renormalization group (RG) approach F(x)=g(x)+?-1F(?x) of an observable F as a function of a control parameter x. For systems for which the RG equation has not been derived, the previous equation can be understood as a Jackson q integral, which is the natural tool for describing discrete-scale invariance. We classify the ``Weierstrass-type'' solutions of the RG into two classes characterized by the amplitudes An of the power-law series expansion. These two classes are separated by a novel ``critical'' point. Growth processes (DLA), rupture, earthquake, and financial crashes thus seem to be characterized by oscillatory or bounded regular microscopic functions that lead to a slow power-law decay of An, giving strong log-periodic amplitudes. If in addition, the phases of An are ergodic and mixing, the observable presents self-affine nondifferentiable properties. In contrast, the regular function of statistical physics models with ``ferromagnetic''-type interactions at equibrium involves unbound logarithms of polynomials of the control variable that lead to a fast exponential decay of An giving weak log-periodic amplitudes and smoothed observables.

Gluzman, S.; Sornette, D.

2002-03-01

198

Critical care procedure logging using handheld computers  

PubMed Central

Introduction We conducted this study to evaluate the feasibility of implementing an internet-linked handheld computer procedure logging system in a critical care training program. Methods Subspecialty trainees in the Interdepartmental Division of Critical Care at the University of Toronto received and were trained in the use of Palm handheld computers loaded with a customized program for logging critical care procedures. The procedures were entered into the handheld device using checkboxes and drop-down lists, and data were uploaded to a central database via the internet. To evaluate the feasibility of this system, we tracked the utilization of this data collection system. Benefits and disadvantages were assessed through surveys. Results All 11 trainees successfully uploaded data to the central database, but only six (55%) continued to upload data on a regular basis. The most common reason cited for not using the system pertained to initial technical problems with data uploading. From 1 July 2002 to 30 June 2003, a total of 914 procedures were logged. Significant variability was noted in the number of procedures logged by individual trainees (range 13–242). The database generated by regular users provided potentially useful information to the training program director regarding the scope and location of procedural training among the different rotations and hospitals. Conclusion A handheld computer procedure logging system can be effectively used in a critical care training program. However, user acceptance was not uniform, and continued training and support are required to increase user acceptance. Such a procedure database may provide valuable information that may be used to optimize trainees' educational experience and to document clinical training experience for licensing and accreditation.

Carlos Martinez-Motta, J; Walker, Robin; Stewart, Thomas E; Granton, John; Abrahamson, Simon; Lapinsky, Stephen E

2004-01-01

199

The X-ray log N-log S relation. [background radiation in extragalactic media  

NASA Technical Reports Server (NTRS)

Results from various surveys are reviewed as regards X-ray source counts at high galactic latitudes and the luminosity functions determined for extragalactic sources. Constraints on the associated log N-log S relation provided by the extragalactic X-ray background are emphasized in terms of its spatial fluctuations and spectrum as well as absolute flux level. The large number of sources required for this background suggests that there is not a sharp boundary in the redshift distribution of visible matter.

Boldt, Elihu

1989-01-01

200

Downhole logs of natural gamma radiation and magnetic susceptibility and their use in interpreting lithostratigraphy in AND-1B, Antarctica  

NASA Astrophysics Data System (ADS)

The ANDRILL McMurdo Ice Shelf (MIS) project drilled 1285 metres of sediment representing the last 14 million years of glacial history. Downhole geophysical logs were acquired to a depth of 1018 metres, and are complementary to data acquired from the core itself. We describe here the natural gamma radiation (NGR) and magnetic susceptibility logs, and their application to understanding lithological and paleoenvironmental change at ANDRILL McMurdo Ice Shelf Hole AND-1B. Natural gamma radiation logs cover the whole interval from the sea floor to 1018 metres, and magnetic susceptibility and other logs covered the open-hole intervals between 692-1018 and 237-342 metres. NGR logs were stacked and corrected for signal attenuation through the drill pipe, and magnetic susceptibility logs were corrected for drift. In the upper part of AND-1B, clear alternations between low and high NGR values distinguish between diatomite (lacking minerals containing naturally radioactive K, U, and Th) and diamict (containing K-bearing clays, K-feldspar, and heavy minerals). In the lower open-hole logged section, NGR and magnetic susceptibility can also distinguish claystones (rich in K-bearing clay minerals, relatively low in magnetite) and diamicts (relatively high in magnetite), while sandstones generally have high resistivity log values at AND-1B. On the basis of these three downhole logs, three sets of facies can be predicted correctly for 74% of the 692-1018m interval. The logs were then used to predict facies for the 7% of this interval that was unrecovered by coring. Similarly, the NGR log provides the best information on the lithology of the poorly recovered top 25m of AND-1B. Given the understanding of the physical property characteristics of different facies, it is also possible to identify subtle changes in lithology from the physical properties, and help refine parts of the lithostratigraphy (for example, the varying terrigenous content of diatomites).

Williams, T.; Morin, R. H.; Jarrard, R. D.; Jackolski, C. L.; Henrys, S. A.; Niessen, F.; Magens, D.; Kuhn, G.; Monien, D.; Powell, R. D.

2010-12-01

201

INSPIRE and SPIRES Log File Analysis  

SciTech Connect

SPIRES, an aging high-energy physics publication data base, is in the process of being replaced by INSPIRE. In order to ease the transition from SPIRES to INSPIRE it is important to understand user behavior and the drivers for adoption. The goal of this project was to address some questions in regards to the presumed two-thirds of the users still using SPIRES. These questions are answered through analysis of the log files from both websites. A series of scripts were developed to collect and interpret the data contained in the log files. The common search patterns and usage comparisons are made between INSPIRE and SPIRES, and a method for detecting user frustration is presented. The analysis reveals a more even split than originally thought as well as the expected trend of user transition to INSPIRE.

Adams, Cole; /Wheaton Coll. /SLAC

2012-08-31

202

Using Web Logs in the Science Classroom  

ERIC Educational Resources Information Center

As educators we must ask ourselves if we are meeting the needs of today's students. The science world is adapting to our ever-changing society; are the methodology and philosophy of our educational system keeping up? In this article, you'll learn why web logs (also called blogs) are an important Web 2.0 tool in your science classroom and how they…

Duplichan, Staycle C.

2009-01-01

203

Subsurface sequence stratigraphic correlation using well logs  

NSDL National Science Digital Library

Students are given hard copies of a subsurface section containing gamma and resistivity logs of nine closely-spaced (well distance varies from 1 to 3 km) wells from Delaware Basin, southeast New Mexico for an interval of ~ 200 m clastic succession of Morrow sandstone of Pennsylvanian age. Core sedimentology of one of these wells is also provided. Students' task is to correlate the well logs to generate a stratigraphic cross-section of the area using sequence stratigraphic approach. As the data are from Delaware Basin, southeast New Mexico, student should first gather the knowledge of regional setting of the basin, with a particular emphasis to the paleo-eustasy. (Clue: in Delaware Basin, Morrow sandstones deposited in a low accommodation settings with high-amplitude fluctuations of sea-level.) When correlating the well logs students should start with the well which has lithological information. Students should try to correlate the mudstones first. The two most prominent sequence stratigraphic surfaces with comparatively higher correlation-length are 'sequence boundary' produced by pronounced fall of sea-level, and 'maximum flooding surface' generated at the time of highest stand of sea-level. Students should pay particular attention to incised-valley-fill deposits. After completing the correlation, students should check whether their correlation satisfy our prevailing ideas of sequence stratigraphy and stratal packaging. Student should prepare a brief description of overall depositional environments and sea-level history of the area substantiating their subsurface correlation. By doing this exercise, students will learn how to apply sequence stratigraphic principles in interpreting subsurface data, particularly from well logs.

Gani, M. R.

204

A composite lithology log while drilling  

SciTech Connect

A new method for producing a computerized composite lithology log (CLL) while drilling by integrating MWD (measurement while drilling) and surface data is described. The CLL integrates three types of data (MWD mechanical, MWD geophysical, and surface cuttings) acquired during drilling, in three time stages: (1) Real Time. MWD drilling mechanical data including the rate of penetration and the downhole torque. This stage would provide bed boundaries and some inferred lithology. This would assist the driller with immediate drilling decisions and determine formation tops for coring, casing point, and correlation. (2) MWD Time. Recomputation of the above by adding MWD geophysical data (gamma-ray, resistivity, neutron-density). This stage would upgrade the lithology inference, and give higher resolution of bed boundaries. (3) Lag Time. Detailed analysis of surface cuttings to confirm the inferred lithologies. This last input will result in a high-quality CLL with accurate lithologies and bed boundaries. The log will serve the geologist as well as the driller, petrophysicist, and reservoir engineer. It will form the basis for more comprehensive formation evaluation while drilling by adding hydrocarbon and MWD log data.

Tannenbaum, E.; Sutcliffe, B.; Franks, A.

1988-02-01

205

A composite lithology log while drilling  

SciTech Connect

A new method for producing a computerized composite lithology log (CLL) while drilling by integrating MWD (measurement while drilling) and surface data is described. At present, lithology logs are produced at the well site by mud loggers. They provide basic description and relative amounts of lithologies. Major difficulties are encountered in relating the cuttings to their original formations due to mixing in the drilling mud while transporting to the surface, sloughing shales, flawed sampling, etc. This results in a poor control on the stratigraphic sequence and on the depth of formation boundaries. A composite log can be produced after drilling this additional inputs such as wireline, petrography, and paleontology. This process is labor intensive and expensive. The CLL integrates three types of data (MWD mechanical, MWD geophysical, and surface cuttings) acquired during drilling, in three time stages: (1) Real Time. MWD drilling mechanical data including the rate of penetration and the downhole torque. This stage would provide bed boundaries and some inferred lithology. This would assist the driller with immediate drilling decisions and determine formation tops for coring, casing point, and correlation. (2) MWD Time. Recomputation of the above by adding MWD geophysical data (gamma-ray, resistivity, neutron-density). This stage would upgrade the lithology inference, and give higher resolution to bed boundaries, (3) Lag Time. Detailed analysis of surface cuttings to confirm the inferred lithologies. This last input results in a high-quality CLL with accurate lithologies and bed boundaries.

Tannenbaum, E.; Sutcliffe, B.; Franks, A.

1988-01-01

206

Improved environmental corrections for Compensated Neutron Logs  

SciTech Connect

The basic openhole responses and environmental correction algorithms for CNL logs have been updated. The improved processing is based on an extensive set of laboratory formation measurements to which mathematical modeling calculations have been added. In all, the new algorithms include basic responses for the three principal formation matrix types and corrections for seven environmental effects and formation fluid salinity. A total of 467 laboratory formation measurements have been augmented with 245 data points generated through mathematical modeling. This data base has been used to define more accurately the effects on the tool response of variations in logging conditions from those considered standard in the laboratory. More accurate corrections for the effects of formation pressure, temperature, mudcake, natural or barite mud, and borehole salinity have been defined. Certain other effects are dependent on more than one parameter. For example, the effect of formation salinity is somewhat matrix dependent, and therefore the corrections are handled differently for sandstone, limestone, and dolomite. The effect of tool standoff is dependent on the borehole size, and the standoff correction is consequently larger boreholes. The porosity crossplots and environmental correction charts based on the new algorithms represent a significant evolutionary improvement over previous techniques. They should be an important aid to the use and interpretation of neutron logs.

Gilchrist, W.A. Jr.; Galford, J.E.; Flaum, C.; Soran, P.D.; Gardner, J.S.

1986-01-01

207

Precision pressure/temperature logging tool  

SciTech Connect

Past memory logging tools have provided excellent pressure/temperature data when used in a geothermal environment, and they are easier to maintain and deploy than tools requiring an electric wireline connection to the surface. However, they are deficient since the tool operator is unaware of downhole conditions that could require changes in the logging program. Tools that make ``decisions`` based on preprogrammed scenarios can partially overcome this difficulty, and a suite of such memory tools has been developed at Sandia National Laboratories. The first tool, which forms the basis for future instruments, measures pressure and temperature. Design considerations include a minimization of cost while insuring quality data, size compatibility with diamond-cored holes, operation in holes to 425 C (800 F), transportability by ordinary passenger air service, and ease of operation. This report documents the development and construction of the pressure/temperature tool. It includes: (1) description of the major components; (2) calibration; (3) typical logging scenario; (4) tool data examples; and (5) conclusions. The mechanical and electrical drawings, along with the tool`s software, will be furnished upon request.

Henfling, J.A.; Normann, R.A.

1998-01-01

208

Derive capillary pressure from well logs  

SciTech Connect

A new approach has been developed to estimate in-situ capillary pressure and relative permeability characteristics in the transition zone. The technique is based on incorporating petrophysical data measured on core samples with well log analysis. Relative permeability can be determined for both drainage and inhibition conditions using the matched capillary pressure data. A technique has been developed to extrapolate petro-physical data where core data is absent or not representative of in-situ conditions. It is based on using log data to derive a water saturation vs. depth profile in the transition zone of the formation of interest. The log-derived water saturation distribution is then correlated to generalized capillary pressure curves typical of the formation studied. The capillary pressure type curves are generated from available core data and other petrophysical information. Relative permeability curves are then generated using correlations based on Purcell's model. The technique can be used in multi-layered and homogeneous reservoirs provided that one homogeneous layer is at least 20 ft thick.

Ibrahim, A. (Suez Canal Univ. (Egypt)); Desbrandes, R.; Bassiouni, Z. (Louisiana State Univ., Baton Rouge, LA (United States))

1994-07-01

209

Logging residues: An economic energy source  

SciTech Connect

Full utilization of the forest resource has long been the goal of resource planners. The aim of this project was to identify and test methods of reaching this goal. Forest residues on two recently logged sites representing a range of residue concentration and type were inventoried and classified. Residues were collected into piles and were processed using two different types of mobile chippers. Samples of the processed material were analyzed to determine their physical and energy properties. A portion of the chipped material was transported to a hog fuel boiler for burning. Each phase of the work was monitored to determine productivity, cost and fuel consumption. Results show the cost per tonne for each phase of the operation and the ratio of energy consumed to energy produced. Results indicated that utilization of logging residues for energy is technically feasible. Future research and development is required to develop more cost efficient methods of retrieving, processing and transporting logging residues prior to implementation on a commercial scale.

Blakeney, K.J.

1980-12-01

210

Enhanced resolution processing of compensated neutron logs  

SciTech Connect

Compensated neutron logging (CNL) uses a two-detector system that was developed to reduce borehole effects. The ratio of counting rates from the detectors provides the basic tool response from which a porosity index is obtained. Each detector in this system has a different vertical resolution because of its spacing. A new method of processing the counting rates has been developed to enhance the vertical resolution capabilities of the neutron porosity index by exploiting the better vertical resolution of the near detector. Because no additional or new measurements are required, data from older wells can easily be re-evaluated. Results from the new method have been compared with microspherically focused logs (MicroSFL) and electromagnetic propagation logs (EPT). They show repeatable thin-bed resolution on the order of 1 ft (0.3 m) for data sampled at 6-in. (15-cm) intervals; the typical vertical resolution from ratio processing is approximately 2 ft (0.6 m). The statistical precision of the high-resolution processing is superior to that of the standard ratio method. An additional parameter, obtained with the new processing method, provides information about borehole effects. This parameters can be used for qualitative indications of gas when invasion is not deep and environmental effects are not large. The new method has been applied successfully in carbonate and laminated sand formations. Studies show that thin beds can be detected in high-porosity formations where normal processing has significant statistical variations resulting from reduced counting rates.

Galford, J.E.; Flaum, C.; Gilchrist, W.A. Jr.; Duckett, S.W.

1989-06-01

211

Automatic determination of lithology from well logs  

SciTech Connect

A procedure combining modern wireline measurements with a lithofacies data base has been developed to produce an automatic lithologic description of the formations crossed by a well. The database lithofacies are defined from petrographic knowledge and translated in terms of log responses. The assignment of depth levels to a lithofacies is done with the data base and with a discriminating function (Bayesian decision rule). External knowledge can be taken into account by use of artificial intelligence methods. A confidence factor is produced for each result. Logs currently in the data base are the density, neutron, sonic transit time, gamma ray, photoelectric cross section, and concentrations of thorium, potassium, and uranium. Major lithofacies groups represented in the data base include sandstones, limestones, dolomites, shales, coals, and evaporites. These are subdivided by introducing cement and special minerals and by considering porosity ranges. The construction of the data base is a critical step. It is largely empirical and requires careful calibration against intervals with well-known lithologies (e.g., from cores). The data base can be tuned to local conditions. The procedure has been tested in several environments and compared with cores and mud log descriptions. A detailed lithologic column can be produced at the wellsite and used in decision making. The results can also serve as input for further geologic studies of facies and sequences or for quantitative evaluation of formations.

Delfiner, P.C.; Peyret, O.; Serra, O.

1987-09-01

212

Contribution of logging data to sedimentology and stratigraphy. [Electrofacies  

SciTech Connect

A technique has been developed using multivariate analysis of logging data to give a high-resolution sedimentological description of any sequence of formations. The number of different logs and their range allow determination of many of the physical characteristics of the rock. The definition of a lithofacies has been extended by introducing the concept of an electrofacies, constructed on the basis of all the logging data at any depth interval. Each logging datum is considered a descriptor for purposes of establishing electrofacies in a logged interval. Once established, electrofacies then can be correlated with actual geologic facies, if the logged interval has been cored. 23 refs.

Serra, O.; Abbott, H.T.

1982-02-01

213

Predicting Sediment Strength in Accretionary Complexes Using Geophysical Logs  

NASA Astrophysics Data System (ADS)

A new approach has been taken to predict undrained shear strength of fine grained sediment and soft rock from geophysical logs and core measurements using neural networks. A limited number of undrained shear strength measurements are performed on scientific ocean drilling sediment cores, resulting in a limited, discontinuous data set. A series of neural networks were developed to predict the undrained shear strength of sediments over intervals where strength was not directly measured. The prediction is based on a learned relationship between the suite of downhole geophysical logs and the measurements of undrained shear strength. The use of neural networks to predict shear strength in cores requires that a statistically significant number of shear strength measurements are available to train and test the neural network. Geophysical logs are necessary to develop a relationship with the shear strength measurements. The approach was developed using shear strength data measured on sediment core samples from Ocean Drilling Program (ODP) Leg 162 in intervals ranging from 15 cm to greater than 200 cm. The neural network was able to resolve the shear strength measurements to a depth resolution of approximately 20 cm. The trained neural network was then used to predict the undrained shear strength in an additional borehole that was not used in training the neural network. The predicted shear strength values, when compared with actual shear strength measurements, show good correlation. This proven technique was then applied to the Nankai Trough accretionary prism using data from ODP Legs 131, 190, and 196, resulting in a high depth resolution prediction of shear strength at the deformation front of the prism. The shear strength predictions through the accretionary prism are important when determining the deformation history of the prism. The deformation history controls the fluid flow of the system through the development of faults.

Paulson, M.; Merrill, J.; Moran, K.; Baxter, C.; Ressler, J.

2006-12-01

214

Log-periodic route to fractal functions.  

PubMed

Log-periodic oscillations have been found to decorate the usual power-law behavior found to describe the approach to a critical point, when the continuous scale-invariance symmetry is partially broken into a discrete-scale invariance symmetry. For Ising or Potts spins with ferromagnetic interactions on hierarchical systems, the relative magnitude of the log-periodic corrections are usually very small, of order 10(-5). In growth processes [diffusion limited aggregation (DLA)], rupture, earthquake, and financial crashes, log-periodic oscillations with amplitudes of the order of 10% have been reported. We suggest a "technical" explanation for this 4 order-of-magnitude difference based on the property of the "regular function" g(x) embodying the effect of the microscopic degrees of freedom summed over in a renormalization group (RG) approach F(x)=g(x)+mu(-1)F(gamma x) of an observable F as a function of a control parameter x. For systems for which the RG equation has not been derived, the previous equation can be understood as a Jackson q integral, which is the natural tool for describing discrete-scale invariance. We classify the "Weierstrass-type" solutions of the RG into two classes characterized by the amplitudes A(n) of the power-law series expansion. These two classes are separated by a novel "critical" point. Growth processes (DLA), rupture, earthquake, and financial crashes thus seem to be characterized by oscillatory or bounded regular microscopic functions that lead to a slow power-law decay of A(n), giving strong log-periodic amplitudes. If in addition, the phases of A(n) are ergodic and mixing, the observable presents self-affine nondifferentiable properties. In contrast, the regular function of statistical physics models with "ferromagnetic"-type interactions at equilibrium involves unbound logarithms of polynomials of the control variable that lead to a fast exponential decay of A(n) giving weak log-periodic amplitudes and smoothed observables. PMID:11909200

Gluzman, S; Sornette, D

2002-03-01

215

Computation of porosity and water content from geophysical logs, Yucca Mountain, Nevada  

SciTech Connect

Neutron and density logs acquired in boreholes at Yucca Mountain, Nevada are used to determine porosity and water content as a function of depth. Computation of porosity requires an estimate of grain density, which is provided by core data, mineralogical data, or is inferred from rock type where neither core nor mineralogy are available. The porosity estimate is merged with mineralogical data acquired by X-ray diffraction to compute the volumetric fractions of major mineral groups. The resulting depth-based portrayal of bulk rock composition is equivalent to a whole rock analysis of mineralogy and porosity. Water content is computed from epithermal and thermal neutron logs. In the unsaturated zone, the density log is required along with a neutron log. Water content can also be computed from dielectric logs, which were acquired in only a fraction of the boreholes, whereas neutron logs were acquired in all boreholes. Mineralogical data are used to compute a structural (or bound) water estimate, which is subtracted from the total water estimate from the neutron-density combination. Structural water can be subtracted only from intervals where mineralogical analyses are available; otherwise only total water can be reported. The algorithms and procedures are applied to logs acquired during 1979 to 1984 at Yucca Mountain. Examples illustrate the results. Comparison between computed porosity and core measurements shows systematic differences ranging from 0.005 to 0.04. These values are consistent with a sensitivity analysis using uncertainty parameters for good logging conditions. Water content from core measurements is available in only one borehole, yielding a difference between computed and core-based water content of 0.006.

Nelson, P.H.

1996-12-31

216

Regional-scale Hydrostratigraphic Analysis of the Paskapoo Aquifer Using Normalized Gamma-ray Logs  

NASA Astrophysics Data System (ADS)

The Paskapoo Formation is the major groundwater aquifer system in western Alberta, Canada. The aquifer system covers approximately 65,000 km2, has over 69,000 groundwater wells completed in it, has a maximum thickness of 800 m and consists of a fluvial mudstone and sandstone complex. The formation is divided into the upper Dalehurst Member, the mud dominated Lacombe Member and the basal Haynes Member. In order to develop hydrostratigraphic models of the Paskapoo Fm., it is necessary to understand the distribution and connectivity of the sandstone remnants. Mapping these features is a particularly difficult problem given the size of the region and the complexity of fluvial systems. In 2006 the Government of Alberta mandated that all wire line log readings, including natural gamma-ray logs, must be collected to surface. Tens of thousands of new exploration and production wells have been drilled and logged since 2006. Since wire line logs are in the public domain, it has created a large source of new data for mapping shallow aquifer systems. However, much of the shallow data of interest is collected through casing. A gamma-ray normalization algorithm has been developed to approximately correct for the dampening effects of the casing so that the cased and uncased API log values are equivalent. The algorithm is based on estimating the second and ninety-fifth percentiles of the API values in uncased zones in wells with similar geology to the cased zones that are to be corrected. The API values of cased zones are then adjusted so that their second and ninety-fifth API percentiles are the same as the uncased values. Mudstone and sandstone zones in the logs can be discriminated and the continuity of sandstone units can be investigated. The Haynes member has been previously described as made up of set of stacked sandstone channels. Logs show that the Haynes member is a thick sandstone unit up to 100 m thick and extending over 100 km perpendicular to the Rocky Mountain's thrust front. Logs also show that the Haynes Member is absent in the northern Paskapoo Fm. The overlying Lacombe member is clearly distinguishable from the Haynes member and it consists of smaller channel sandstone remnants which cannot be correlated over large distances, consistent with its description of a mud dominated system. Areas of higher and lower sand fraction are evident in the records. Mapping sand fractions is extremely important as it exerts first order control on regional hydraulic conductivity, vertical conductivity and connectivity within the aquifer. The normalized gamma logs offer a powerful new tool for regional aquifer characterization in Alberta.

Bentley, L. R.; Quartero, E.; Leier, A.; Bechtel, D.

2013-12-01

217

Place Value  

NSDL National Science Digital Library

Practice place value! Fight the pirates in Pirates Place Value Uncover the hidden picture in Place value hidden picture Take the quiz at place value quiz Keep practicing with Place value to 1000 Stretch your brain with Place value to 100,000 ...

Peake, Mrs.

2011-08-18

218

Console Log Keeping Made Easier - Tools and Techniques for Improving Quality of Flight Controller Activity Logs  

NASA Technical Reports Server (NTRS)

At the Marshall Space Flight Center's (MSFC) Payload Operations Integration Center (POIC) for International Space Station (ISS), each flight controller maintains detailed logs of activities and communications at their console position. These logs are critical for accurately controlling flight in real-time as well as providing a historical record and troubleshooting tool. This paper describes logging methods and electronic formats used at the POIC and provides food for thought on their strengths and limitations, plus proposes some innovative extensions. It also describes an inexpensive PC-based scheme for capturing and/or transcribing audio clips from communications consoles. Flight control activity (e.g. interpreting computer displays, entering data/issuing electronic commands, and communicating with others) can become extremely intense. It's essential to document it well, but the effort to do so may conflict with actual activity. This can be more than just annoying, as what's in the logs (or just as importantly not in them) often feeds back directly into the quality of future operations, whether short-term or long-term. In earlier programs, such as Spacelab, log keeping was done on paper, often using position-specific shorthand, and the other reader was at the mercy of the writer's penmanship. Today, user-friendly software solves the legibility problem and can automate date/time entry, but some content may take longer to finish due to individual typing speed and less use of symbols. File layout can be used to great advantage in making types of information easy to find, and creating searchable master logs for a given position is very easy and a real lifesaver in reconstructing events or researching a given topic. We'll examine log formats from several console position, and the types of information that are included and (just as importantly) excluded. We'll also look at when a summary or synopsis is effective, and when extensive detail is needed.

Scott, David W.; Underwood, Debrah (Technical Monitor)

2002-01-01

219

Option Pricing with Log-stable Lévy Processes  

NASA Astrophysics Data System (ADS)

We model the logarithm of the price (log-price) of a financial asset as a random variable obtained by projecting an operator stable random vector with a scaling index matrix \\underline{\\underline E} onto a non-random vector. The scaling index \\underline{\\underline E} models prices of the individual financial assets (stocks, mutual funds, etc.). We find the functional form of the characteristic function of real powers of the price returns and we compute the expectation value of these real powers and we speculate on the utility of these results for statistical inference. Finally we consider a portfolio composed of an asset and an option on that asset. We derive the characteristic function of the deviation of the portfolio, mathfrak{D}_t^{(mathfrak{t})} , defined as a temporal change of the portfolio diminished by the the compound interest earned. We derive pseudo-differential equations for the option as a function of the log-stock-price and time and we find exact closed-form solutions to that equation. These results were not known before. Finally we discuss how our solutions correspond to other approximate results known from literature,in particular to the well known Black & Scholes equation.

Repetowicz, Przemys?aw; Richmond, Peter

220

6. SOUTHWEST CORNER DETAIL (FRONT AND LEFT SIDE) SHOWING LOG ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. SOUTHWEST CORNER DETAIL (FRONT AND LEFT SIDE) SHOWING LOG JOINERY AND WEATHERBOARDING (copy negative, original 35 mm negative in field records) - Thomas Jefferson Walling Log Cabin, Henderson, Rusk County, TX

221

47 CFR 73.877 - Station logs for LPFM stations.  

Code of Federal Regulations, 2013 CFR

...following information must be entered in the station log: (a) Any extinguishment...replacement; (c) Operations not in accordance with the station license; and (d) EAS weekly log requirements set forth in § 11.61(a)(1)(v)...

2013-10-01

222

47 CFR 73.782 - Retention of logs.  

Code of Federal Regulations, 2013 CFR

...Provided, however, That logs involving communications...incident to or involved in an investigation by...specifically authorized in writing by the Commission...Provided, further, That logs incident to or involved in any claim or...

2013-10-01

223

7. NORTHEAST CORNER DETAIL SHOWING LOG JOINERY. AT RIGHT IS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. NORTHEAST CORNER DETAIL SHOWING LOG JOINERY. AT RIGHT IS REAR SHED ROOM ADDITION (copy negative, original 35 mm negative in field records) - Thomas Jefferson Walling Log Cabin, Henderson, Rusk County, TX

224

21 CFR 211.182 - Equipment cleaning and use log.  

Code of Federal Regulations, 2013 CFR

...lubrication and adjustments), and use shall be included in individual equipment logs that show the date, time, product, and lot...indicating that the work was performed. Entries in the log shall be in chronological order. [73 FR 51933,...

2013-04-01

225

46 CFR 131.620 - Matters that must be logged.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Logs § 131.620 Matters that must be logged. The following matters must be entered in each vessel's logbook: (a) Safety Orientation for Offshore...

2013-10-01

226

Televiewer Logging of Exploration Boreholes for Mine Design  

Microsoft Academic Search

Acoustic televiewer surveys were run in sulphide exploration boreholes at three INCO properties in Canada. The televiewer logs provide valuable structural and geotechnical information for mine design purposes. Examples illustrating the analysis and interpretation of Acoustic televiewer logs are given.

G. M. McDowell

227

Geostatistical Simulation of Acoustic Log Data for Seismic Depth Conversion  

SciTech Connect

Seismic reflection methods measure the time a seismic wave takes to travel through the ground, from the user defined source to a series of signal monitoring sensors known as geophones. The measured times need to be depth converted to allow for integration with other geological data. In order to convert from time to depth, an estimate of the rock volume velocity field must be made. The velocity field estimate can be made by assignment of velocity estimates to a geological model independent of the seismic processing. This article presents the results of using the acoustic geophysical log data extrapolated via sequential Gaussian simulation to derive the velocity field. The uncertainties associated with the velocity estimates were significant and provided the means to assess confidence limits for the actual depth determination. The technique is assessed by application to a major coal deposit, approximately 2.1 m thick and 210 m deep. Considering only the uncertainty associated with estimating the velocity field, half of the confidence interval values showed approximately 1 m of uncertainty in depth. The application of sequential Gaussian simulation to model the 3D distribution of acoustic velocity can be extended to other geophysical log parameters or derived estimates.

Koppe, Vanessa Cerqueira; Costa, Joao Felipe Coimbra Leite, E-mail: jfelipe@ufrgs.br; Koppe, Jair Carlos; Gambin, Fernando [UFRGS, Mining Engineering Department (Brazil); Fallon, Gary; Davies, Nick [Now Geophysical Resources and Services, Formerly Xstrata Inc (Australia)

2007-12-15

228

Values and the Valuing Process.  

ERIC Educational Resources Information Center

This paper develops a basic conceptual framework of values and the valuing process. Section 1, Values and Value Claims, discusses the four different types of value claims (personal, market, real, and implicit) and their relationships. The second section considers the process of rational evaluation as a method of arriving at and supporting value

Scriven, Michael

229

A Highly Available Log Service for Transaction Termination  

Microsoft Academic Search

Distributed transaction processing hinges on enforcing agreement among the involved resource managers on whether to commit or abort transactions (atomicity) and on making their updates permanent (durability). This paper introduces a log service which abstracts these tasks. The service logs commit and abort votes as well as the updates performed by each resource manager. Based on the votes, the log

Lásaro J. Camargos; Marcin Wieloch; Fernando Pedone; Edmundo Roberto Mauro Madeira

2008-01-01

230

31 CFR 593.309 - Round log or timber product.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Round log or timber product. 593.309 ...Definitions § 593.309 Round log or timber product. The term round log or timber product means any product classifiable in Chapter 44 of the Harmonized...

2013-07-01

231

47 CFR 80.1153 - Station log and radio watches.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Station log and radio watches. 80...RADIO SERVICES STATIONS IN THE MARITIME SERVICES... § 80.1153 Station log and radio watches...maintain radio station logs. (b) When a ship...watches must be maintained in accordance with §§...

2013-10-01

232

The Log-polar Image Representation in Pattern Recognition Tasks  

Microsoft Academic Search

This paper is a review of works about the use of the log- polar image model for pattern recognition purposes. Particular attention is paid to the rotation-and scale- invariant pattern recognition problem, which is simplified by the log-polar mapping. In spite of this advantage, ordinary translations become a complicated image transform in the log- polar domain. Two approaches addressing the

V. Javier Traver; Filiberto Pla

2003-01-01

233

New logging tool identifies permeability in shaley sands  

Microsoft Academic Search

A logging tool overcame questionable results obtained by routine core analysis and other conventional techniques for identifying permeable zones. For this test, Lomax Exploration Co., in conjunction with the US Department of Energy (DOE), used Numar corp.'s magnetic resonance imaging log (MRIL) in the Monument Butte field, Duchesne County, Utah. The tool also enhanced the interpretation of conventional logs over

J. Lomax; A. Howard

1994-01-01

234

Western tight gas sands advanced logging workshop proceedings  

Microsoft Academic Search

An advanced logging research program is one major aspect of the Western Tight Sands Program. Purpose of this workshop is to help BETC define critical logging needs for tight gas sands and to allow free interchange of ideas on all aspects of the current logging research program. Sixteen papers and abstracts are included together with discussions. Separate abstracts have been

J. B. Jennings; H. B. Jr. Carroll

1982-01-01

235

Gamma ray spectral logging: A new evaluation frontier  

SciTech Connect

In the evaluation of clastic reservoirs, even the slightest amount of accessory minerals present in an otherwise clean formation can distort the readings from conventional well logs. In this case, natural gamma ray spectral logging has proven a useful aid. This article addresses the use of the spectral log in glauconitic sand, chert arenites, granite washes and micaceous sandstones.

Fertl, W.H.

1983-08-01

236

EFFECTS OF LOG HANDLING AND STORAGE ON WATER QUALITY  

EPA Science Inventory

The biological and chemical effects of three types of log storage on water quality were investigated. Three flow-through log ponds, two wet deck operations, and five log rafting areas were studied. Both biological and chemical aspects of stream quality can be adversely affected b...

237

General Test Result Checking with Log File Analysis  

Microsoft Academic Search

We describe and apply a lightweight formal method for checking test results. The method assumes that the software under test writes a text log file; this log file is then analyzed by a program to see if it reveals failures. We suggest a state-machine-based formalism for specifying the log file analyzer programs and describe a language and implementation based on

James H. Andrews; Yingjun Zhang

2003-01-01

238

Evaluating and logging tight rocks of south Texas  

Microsoft Academic Search

Drilling and production experience in the tight-rock oil- and gas-producing sands in south Texas have taught operators the importance of comprehensive logging programs for evaluating the formations, notes Schlumberger Well Services. Sample logs from throughout the play show that porosity and shaliness are often the deciding factors in determining whether a zone will produce commercially. The minimum logging program needed

Fett

1980-01-01

239

Method and apparatus for logging earth boreholes. [in deviated wells  

Microsoft Academic Search

A self-contained, battery powered well logging instrument is pumped down the interior of a drill pipe string having a catcher sub at its lower end. When the logging instrument latches into the catcher sub, the pumped fluid circulation is blocked, after which increased pump pressure switches a valve assembly to recreate circulation and energize the logging instrument to the standby

Angehrn

1977-01-01

240

1Mochi: Visual Log-Analysis Based Tools for Debugging Hadoop  

Microsoft Academic Search

Mochi, a new visual, log-analysis based debugging tool correlates Hadoop's behavior in space, time and vol- ume, and extracts a causal, unified control- and data- flow model of Hadoop across the nodes of a cluster. Mochi's analysis produces visualizations of Hadoop's behavior using which users can reason about and debug performance issues. We provide examples of Mochi's value in revealing

Jiaqi Tan; Xinghao Pan; Soila Kavulya; Rajeev Gandhi; Priya Narasimhan

241

Generalisation log for managing and utilising a multi-representation spatial database in map production  

Microsoft Academic Search

This paper describes a data model for logging map generalisation process information to facilitate data authentication and update propagation in a multi-representation spatial database environment. Generalisation is modelled as a directed acyclic diagram of prioritised generalisation process instances, which is further divided into independent operations as the atomic functional unit for generalisation. Generalisation parameter values and the roles of features

Sheng Zhou; Nicolas Regnauld; Carsten Roensdorf

2009-01-01

242

Linear-log counting-rate meter uses transconductance characteristics of a silicon planar transistor  

NASA Technical Reports Server (NTRS)

Counting rate meter compresses a wide range of data values, or decades of current. Silicon planar transistor, operating in the zero collector-base voltage mode, is used as a feedback element in an operational amplifier to obtain the log response.

Eichholz, J. J.

1969-01-01

243

Nondestructive rule-based defect detection and identification system in CT images of hardwood logs  

Microsoft Academic Search

This paper is concerned with the detection of internal defects in hardwood logs. Because the commercial value of hardwood lumber is directly related to the quantity, type, and location of defects in the wood, sawing strategies are typically chosen in an attempt to minimize the defects in the resulting boards. Traditionally, the sawyer makes sawing decisions by visually examining the

Erol Sarigul; A. Lynn Abbott; Daniel L. Schmoldt

2001-01-01

244

VAFLE: visual analytics of firewall log events  

NASA Astrophysics Data System (ADS)

In this work, we present VAFLE, an interactive network security visualization prototype for the analysis of firewall log events. Keeping it simple yet effective for analysts, we provide multiple coordinated interactive visualizations augmented with clustering capabilities customized to support anomaly detection and cyber situation awareness. We evaluate the usefulness of the prototype in a use case with network traffic datasets from previous VAST Challenges, illustrating its effectiveness at promoting fast and well-informed decisions. We explain how a security analyst may spot suspicious traffic using VAFLE. We further assess its usefulness through a qualitative evaluation involving network security experts, whose feedback is reported and discussed.

Ghoniem, Mohammad; Shurkhovetskyy, Georgiy; Bahey, Ahmed; Otjacques, Benoît.

2013-12-01

245

Calibration Tests of a German Log Rodmeter  

NASA Technical Reports Server (NTRS)

A German log rodmeter of the pitot static type was calibrated in Langley tank no. 1 at speeds up to 34 knots and angles of yaw from 0 deg to plus or minus 10 3/4 degrees. The dynamic head approximated the theoretical head at 0 degrees yaw but decreased as the yaw was increased. The static head was negative and in general became more negative with increasing speed and yaw. Cavitation occurred at speeds above 31 knots at 0 deg yaw and 21 knots at 10 3/4 deg yaw.

Mottard, Elmo J.; Stillman, Everette R.

1949-01-01

246

Identifying related journals through log analysis  

PubMed Central

Motivation: With the explosion of biomedical literature and the evolution of online and open access, scientists are reading more articles from a wider variety of journals. Thus, the list of core journals relevant to their research may be less obvious and may often change over time. To help researchers quickly identify appropriate journals to read and publish in, we developed a web application for finding related journals based on the analysis of PubMed log data. Availability: http://www.ncbi.nlm.nih.gov/IRET/Journals Contact: luzh@ncbi.nlm.nih.gov Supplementary information: Supplementary data are available at Bioinformatics online.

Lu, Zhiyong; Xie, Natalie; Wilbur, W. John

2009-01-01

247

Impact of selective logging on inbreeding and gene dispersal in an Amazonian tree population of Carapa guianensis Aubl.  

PubMed

Selective logging may impact patterns of genetic diversity within populations of harvested forest tree species by increasing distances separating conspecific trees, and modifying physical and biotic features of the forest habitat. We measured levels of gene diversity, inbreeding, pollen dispersal and spatial genetic structure (SGS) of an Amazonian insect-pollinated Carapa guianensis population before and after commercial selective logging. Similar levels of gene diversity and allelic richness were found before and after logging in both the adult and the seed generations. Pre- and post-harvest outcrossing rates were high, and not significantly different from one another. We found no significant levels of biparental inbreeding either before or after logging. Low levels of pollen pool differentiation were found, and the pre- vs. post-harvest difference was not significant. Pollen dispersal distance estimates averaged between 75 m and 265 m before logging, and between 76 m and 268 m after logging, depending on the value of tree density and the dispersal model used. There were weak and similar levels of differentiation of allele frequencies in the adults and in the pollen pool, before and after logging occurred, as well as weak and similar pre- and post-harvest levels of SGS among adult trees. The large neighbourhood sizes estimated suggest high historical levels of gene flow. Overall our results indicate that there is no clear short-term genetic impact of selective logging on this population of C. guianensis. PMID:17284212

Cloutier, D; Kanashiro, M; Ciampi, A Y; Schoen, D J

2007-02-01

248

Sorption of organic chemicals to soil organic matter: influence of soil variability and pH dependence.  

PubMed

For modeling the sorption of organic compounds in soils it is typically assumed that the organic carbon/water partitioning coefficient (Koc) of neutral organic chemicals can be treated as a constant property that remains unaffected by the type of soil organic matter as well as pH in the soil solution. Here the validity of these assumptions is evaluated with a large and diverse experimental data set of our own and literature data. To this end sorption experiments with 3 different soils and one peat were carried out using a column method. Differences in log Koc at pH values of 4.5 and 7.2 were on average <0.06 log units for 60 chemicals on Pahokee Peat. This result indicates that protonation/deprotonation of carboxylic groups in humic matter has no significant influence on sorption. The soil-to-soil variability of Koc was within factor of 3 regardless of the type of chemicals. The Pahokee Peat standard from the International Humic Substances Society appears to represent Koc in solid soil organic matter from different origins with an accuracy of ±0.23 log units (root-mean-square error). The comparison of the sorption data in Pahokee Peat with literature sorption data from the air in hydrated humic and fulvic acids suggested that the thermodynamic cycle for converting sorption data between air and water is applicable provided that for small, highly polar chemicals an additional water phase in the hydrated organic matter is considered. PMID:21194206

Bronner, Guido; Goss, Kai-Uwe

2011-02-15

249

Development of a log-quadratic model to describe microbial inactivation, illustrated by thermal inactivation of Clostridium botulinum.  

PubMed

In the commercial food industry, demonstration of microbiological safety and thermal process equivalence often involves a mathematical framework that assumes log-linear inactivation kinetics and invokes concepts of decimal reduction time (D(T)), z values, and accumulated lethality. However, many microbes, particularly spores, exhibit inactivation kinetics that are not log linear. This has led to alternative modeling approaches, such as the biphasic and Weibull models, that relax strong log-linear assumptions. Using a statistical framework, we developed a novel log-quadratic model, which approximates the biphasic and Weibull models and provides additional physiological interpretability. As a statistical linear model, the log-quadratic model is relatively simple to fit and straightforwardly provides confidence intervals for its fitted values. It allows a D(T)-like value to be derived, even from data that exhibit obvious "tailing." We also showed how existing models of non-log-linear microbial inactivation, such as the Weibull model, can fit into a statistical linear model framework that dramatically simplifies their solution. We applied the log-quadratic model to thermal inactivation data for the spore-forming bacterium Clostridium botulinum and evaluated its merits compared with those of popular previously described approaches. The log-quadratic model was used as the basis of a secondary model that can capture the dependence of microbial inactivation kinetics on temperature. This model, in turn, was linked to models of spore inactivation of Sapru et al. and Rodriguez et al. that posit different physiological states for spores within a population. We believe that the log-quadratic model provides a useful framework in which to test vitalistic and mechanistic hypotheses of inactivation by thermal and other processes. PMID:19767461

Stone, G; Chapman, B; Lovell, D

2009-11-01

250

Dual excitation acoustic paramagnetic logging tool  

DOEpatents

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in gelogical formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleous present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described.

Vail, III, William B. (Bothell, WA)

1989-01-01

251

Dual excitation acoustic paramagnetic logging tool  

DOEpatents

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be performed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described. 6 figs.

Vail, W.B. III.

1989-02-14

252

Close-Call Action Log Form  

NASA Technical Reports Server (NTRS)

"Close Call Action Log Form" ("CCALF") is the name of both a computer program and a Web-based service provided by the program for creating an enhanced database of close calls (in the colloquial sense of mishaps that were avoided by small margins) assigned to the Center Operations Directorate (COD) at Johnson Space Center. CCALF provides a single facility for on-line collaborative review of close calls. Through CCALF, managers can delegate responses to employees. CCALF utilizes a pre-existing e-mail system to notify managers that there are close calls to review, but eliminates the need for the prior practices of passing multiple e-mail messages around the COD, then collecting and consolidating them into final responses: CCALF now collects comments from all responders for incorporation into reports that it generates. Also, whereas it was previously necessary to manually calculate metrics (e.g., numbers of maintenance-work orders necessitated by close calls) for inclusion in the reports, CCALF now computes the metrics, summarizes them, and displays them in graphical form. The reports and all pertinent information used to generate the reports are logged, tracked, and retained by CCALF for historical purposes.

Spuler, Linda M.; Ford, Patricia K.; Skeete, Darren C.; Hershman, Scot; Raviprakash, Pushpa; Arnold, John W.; Tran, Victor; Haenze, Mary Alice

2005-01-01

253

Log curve amplitude slicing: Visualization of well log amplitudes for paleogeographic reconstruction of the Middle Devonian Traverse Group, Michigan Basin  

Microsoft Academic Search

Well log curve shapes and amplitude trends are routinely used to correlate and map formations and reservoirs across petroleum basins or fields. The methods typically employed for correlation and mapping fail, however, to make full use of the vertical resolution of well log curves. A new technique, log curve amplitude slicing (LCAS) facilitates correlation by generating a series of subhorizontal

Albert Sidney Wylie Jr.

2002-01-01

254

Evaluating and logging tight rocks of south Texas  

SciTech Connect

Drilling and production experience in the tight-rock oil- and gas-producing sands in south Texas have taught operators the importance of comprehensive logging programs for evaluating the formations, notes Schlumberger Well Services. Sample logs from throughout the play show that porosity and shaliness are often the deciding factors in determining whether a zone will produce commercially. The minimum logging program needed to evaluate tight-rock sands includes an induction-resistivity log and a compensated density-neutron-gamma-ray log.

Fett, T.H.

1980-02-01

255

Prediction of thermal conductivity of sedimentary rocks from well logs  

NASA Astrophysics Data System (ADS)

The calculation of heat-flow density in boreholes requires reliable values for the change of temperature and rock thermal conductivity with depth. As rock samples for laboratory measurements of thermal conductivity (TC) are usually rare geophysical well logs are used alternatively to determine TC. A common procedure in the latter approach is the use of empirical relations between TC and different petrophysical properties. Although numerous prediction equations were developed in the past five decades, none of these seem to be universally applicable for all major types of sedimentary rocks (clastics, carbonates and evaporites). In addition, these relations mostly are suitable only for regions and lithotypes for which they were originally developed. A new set of predictive equations is presented which overcomes these limitations and which allows the prediction of the rock matrix TC based on different combinations of standard geophysical well-logs. In combination with a feasible mixing-model (i.e. geometric mean model) bulk TC is computed along borehole profiles. The underlying approach was proposed by Fuchs & Förster (2014) and rests upon the detailed analysis of the interrelations between major physical parameters (i.e. thermal conductivity, density, hydrogen index, sonic interval transit time, gamma-ray response, photoelectric factor) of artificial mineral assemblages consisting 15 rock-forming minerals that are used in different combinations to typify sedimentary rocks. The predictive capacity of the new equations is evaluated on subsurface data from four boreholes drilled into the Mesozoic sequence of the North German Basin, including more than 1700 laboratory-measured thermal-conductivity values. Results are compared with those from other approaches published in the past. The new approach predicts TC with a mean error between 10 and 15 % compared to earlier approaches of much higher error of 15-35 % (and sometimes higher).

Fuchs, Sven; Förster, Andrea

2014-05-01

256

Borehole induction logging for the Dynamic Underground Stripping Project LLNL gasoline spill site  

SciTech Connect

Borehole induction logs were acquired for the purpose of characterizing subsurface physical properties and monitoring steam clean up activities at the Lawrence Livermore National Laboratory. This work was part of the Dynamic Underground Stripping Project`s demonstrated clean up of a gasoline spin. The site is composed of unconsolidated days, sands and gravels which contain gasoline both above and below the water table. Induction logs were used to characterize lithology, to provide ``ground truth`` resistivity values for electrical resistance tomography (ERT), and to monitor the movement of an underground steam plume used to heat the soil and drive volatile organic compounds (VOCs) to the extraction wells.

Boyd, S.; Newmark, R.; Wilt, M.

1994-01-21

257

Artificial intelligence and mathematical modeling applied to wireline log interpretation  

SciTech Connect

Wireline log interpretation is a powerful tool for evaluation of formation characteristics which in turn are used for identification of reservoir and estimation of recoverable hydrocarbons. The log data is stored and plotted using computer applications but manual procedures are mostly adopted for reading the logs and interpreting their signature into the subsurface formations. Keeping in view the new trend of applying artificial intelligence and neural networks to geological applications, an artificial intelligence based approach has been developed for computerized interpretation of logs. The working of this technique involves mathematical models based on curve analyzers which take into account the changing trend of each log curve and then pool out parameters to mathematical equations or directly to the artificial intelligent logic. Such logic has been developed for interpreting all major types of logs like spontaneous potential, gamma ray, sonic, density, neuron and various types of resistivity logs. Thus each log is interpreted independently, for example sand line and shale base lines are automatically marked from spontaneous potential logs and clay percentage is mapped from gamma ray logs. Finally an integrated artificial intelligent analysis takes into account all the logs, their independent interpretations and the local geological information and interprets the subsurface geological picture comprising of various formations.

Khan, K.A. [Oil and Gas Development Corporation, Islamabad (Pakistan)

1995-08-01

258

Understanding MWD data acquisition can improve log interpretation  

SciTech Connect

By understanding how measurement-while-drilling (MWD) tools acquire data and how the data are processed, engineers and geologists can better interpret MWD logs. Wire line and MWD log data sometimes do not precisely match. If a discrepancy occurs between MWD and wire line logs run across the same interval, many log interpreters will condemn the MWD data. Recognizing the differences and the correct data requires a better understanding of the MWD tool operational principles. Because MWD logs are becoming more widely accepted as quantitative replacements for equivalent wire line logs, the differences between logs should be analyzed logically. This paper discusses these differences by describing the following: time-based acquisition, filtering, depth control, environmental variables, and quality control.

Fagin, R.A. (Atlas Wireline Services, Houston, TX (United States))

1994-02-14

259

Methods for interpretation of tensor induction well logging in layered anisotropic formations  

NASA Astrophysics Data System (ADS)

One of the most challenging problems in the field of electromagnetic well logging is the development of interpretation methods for the characterization of conductivity anisotropy in an earth formation. Response of a triaxial electromagnetic induction well logging instrument is examined. This instrument detects three components of the magnetic field due to each of three transmitters for a total of nine signals. The conductivity anisotropy of the medium can be resolved from the instrument response. This information includes not only the vertical and horizontal conductivities, but also the orientation of the logging instrument axis with respect to the principal tensor axes. Formulas for the apparent horizontal and vertical conductivities, the apparent anisotropy coefficient, and the apparent relative deviation angle are introduced. A new method of induction logging based on electrical measurements is investigated. Electrical tensor components are studied in an unbounded, homogeneous, transversely isotropic, conductive medium. Low frequency asymptotic approximations of the analytical solution are derived. The important result is that by measuring the in-phase components of the electrical tensor, the principal values of the conductivity tensor can be obtained. The basic principles of tensor induction logging two-, three-, and multilayer anisotropic formations in vertical and deviated wells are examined by using numerical simulation of the tensor logs. A technique for correct reconstruction of the apparent conductivities of the anisotropic formations is introduced, based on application of a regularized Newton method. The method is fast and provides real time interpretation. The practical effectiveness of this technique for tensor induction log interpretation is illustrated using results of numerical experiments. The theoretical formulas for the tensor apparent conductivities of the transversely isotropic medium are studied and developed for an ideal tensor induction instrument with coinciding positions of three mutually orthogonal transmitters at one point and all three receivers at the other point in a borehole. Formulas can be corrected for practical instrument design. Corrected formulas for a practical tensor induction well logging instrument are introduced. The numerical study shows, that for various anisotropy values, corrected apparent conductivities are practically the same as the theoretical apparent parameters. A new technique for interpretation of tensor induction well logging (TIWL) data is presented. This method is called sharp boundary inversion, based on using specially selected stabilizing functionals, which minimize the area where strong model parameter variations and discontinuities occur. The method recovers the sharp boundary between various anisotropic geoelectrical layers and reconstructs both horizontal and vertical resistivity profiles. The new TIWL interpretation methods are illustrated by application to the synthetic models of layered anisotropic formations. These methods are applied to the typical benchmark petrophysical models.

Peksen, Ertan

260

Place Value  

NSDL National Science Digital Library

These activites cover place value of ones, tens, hundreds and thousands. Please complete the games in order. You must finish each game before going on to the next one. Game #1: Dinosaur Numbers (place value) Game #2: Shark Numbers (place value) Game #3: Place Value Golf (harder) ...

Christian, Mrs.

2007-03-21

261

Calibration of a neutron log in partially saturated media. Part II. Error analysis  

SciTech Connect

Four sources or error (uncertainty) are studied in water content obtained from neutron logs calibrated in partially saturated media for holes up to 3 m. For this calibration a special facility was built and an algorithm for a commercial epithermal neutron log was developed that obtains water content from count rate, bulk density, and gap between the neutron sonde and the borehole wall. The algorithm contained errors due to the calibration and lack of fit, while the field measurements included uncertainties in the count rate (caused by statistics and a short time constant), gap, and density. There can be inhomogeneity in the material surrounding the borehole. Under normal field conditions the hole-size-corrected water content obtained from such neutron logs can have an uncertainty as large as 15% of its value.

Hearst, J.R.; Kasameyer, P.W.; Dreiling, L.A.

1981-03-20

262

Generalized q analysis of log-periodicity: Applications to critical ruptures  

NASA Astrophysics Data System (ADS)

We introduce a generalization of the q analysis, which provides a nonparametric tool for the description and detection of log-periodic structures associated with discrete scale invariance. We use this generalized q analysis to construct a signature called the (H,q) derivative of discrete scale invariance, which we use to detect the log-periodicity in the cumulative energy release preceding the rupture of five pressure tanks made of composite carbon-matrix material. We investigate the significance level of the spectral Lomb periodogram of the optimal (H,q) derivative. We confirm and strengthen previous parametric results that the cumulative energy release exhibits log-periodicity before rupture. However, our tests to use this method as a scheme for the prediction of the critical value of the stress at rupture are not encouraging.

Zhou, Wei-Xing; Sornette, Didier

2002-10-01

263

Generalized q analysis of log-periodicity: applications to critical ruptures.  

PubMed

We introduce a generalization of the q analysis, which provides a nonparametric tool for the description and detection of log-periodic structures associated with discrete scale invariance. We use this generalized q analysis to construct a signature called the (H,q) derivative of discrete scale invariance, which we use to detect the log-periodicity in the cumulative energy release preceding the rupture of five pressure tanks made of composite carbon-matrix material. We investigate the significance level of the spectral Lomb periodogram of the optimal (H,q) derivative. We confirm and strengthen previous parametric results that the cumulative energy release exhibits log-periodicity before rupture. However, our tests to use this method as a scheme for the prediction of the critical value of the stress at rupture are not encouraging. PMID:12443263

Zhou, Wei-Xing; Sornette, Didier

2002-10-01

264

Permutational distribution of the log-rank statistic under random censorship with applications to carcinogenicity assays.  

PubMed

In the random censorship model, the log-rank test is often used for comparing a control group with different dose groups. If the number of tumors is small, so-called exact methods are often applied for computing critical values from a permutational distribution. Two of these exact methods are discussed and shown to be incorrect. The correct permutational distribution is derived and studied with respect to its behavior under unequal censoring in the light of recent results proving that the permutational version and the unconditional version of the log-rank test are asymptotically equivalent even under unequal censoring. The log-rank test is studied by simulations of a realistic scenario from a bioassay with small numbers of tumors. PMID:9544515

Heimann, G; Neuhaus, G

1998-03-01

265

In-Home Demonstration of the Reduction of Woodstove Emissions from the Use of Densified Logs.  

SciTech Connect

There is a need to reduce emissions from conventional wood stoves in the short-term while stove replacement takes place over the longer term. One possible is to use fuels that would burn cleaner than cordwood. Densified fuels have been commercially available for years and offer such a possibility. The objective of this project was to evaluate the emissions and efficiency performance of two commercially available densified log types in homes and compare their performance with cordwood. Researchers measured particulate matter (PM), carbon monoxide (CO), and volatile organic matter (VOC) emissions. Both total VOC and methane values are presented. Each home used an Automated Woodstove Emissions Sampler system, developed for the EPA and Bonneville Power Administration, in a series of four week-long tests for each stove. The sequence of tests in each stove was cordwood, Pres-to-Logs, Eco-Logs, and a second, confirming test using Pres-to-Logs. Results show an average reduction of 52% in PM grams per hour emissions overall for the nine stoves using Pres-to-Logs. All nine stoves displayed a reduction in PM emissions. CO emissions were more modestly reduced by 27%, and VOCs were reduced 39%. The emissions reduction percentage was similar for both types of stoves.

Barnett, Stockton G.; Bidhouse, Roger D.

1992-07-07

266

In-home demonstration of the reduction of woodstove emissions from the use of densified logs  

SciTech Connect

There is a need to reduce emissions from conventional wood stoves in the short-term while stove replacement takes place over the longer term. One possible is to use fuels that would burn cleaner than cordwood. Densified fuels have been commercially available for years and offer such a possibility. The objective of this project was to evaluate the emissions and efficiency performance of two commercially available densified log types in homes and compare their performance with cordwood. Researchers measured particulate matter (PM), carbon monoxide (CO), and volatile organic matter (VOC) emissions. Both total VOC and methane values are presented. Each home used an Automated Woodstove Emissions Sampler system, developed for the EPA and Bonneville Power Administration, in a series of four week-long tests for each stove. The sequence of tests in each stove was cordwood, Pres-to-Logs, Eco-Logs, and a second, confirming test using Pres-to-Logs. Results show an average reduction of 52% in PM grams per hour emissions overall for the nine stoves using Pres-to-Logs. All nine stoves displayed a reduction in PM emissions. CO emissions were more modestly reduced by 27%, and VOCs were reduced 39%. The emissions reduction percentage was similar for both types of stoves.

Barnett, S.G.; Bighouse, R.D.

1992-07-07

267

Log-Linear Models for Gene Association  

PubMed Central

We describe a class of log-linear models for the detection of interactions in high-dimensional genomic data. This class of models leads to a Bayesian model selection algorithm that can be applied to data that have been reduced to contingency tables using ranks of observations within subjects, and discretization of these ranks within gene/network components. Many normalization issues associated with the analysis of genomic data are thereby avoided. A prior density based on Ewens’ sampling distribution is used to restrict the number of interacting components assigned high posterior probability, and the calculation of posterior model probabilities is expedited by approximations based on the likelihood ratio statistic. Simulation studies are used to evaluate the efficiency of the resulting algorithm for known interaction structures. Finally, the algorithm is validated in a microarray study for which it was possible to obtain biological confirmation of detected interactions.

Hu, Jianhua; Joshi, Adarsh; Johnson, Valen E.

2009-01-01

268

Tolerance bounds for log gamma regression models  

NASA Technical Reports Server (NTRS)

The present procedure for finding lower confidence bounds for the quantiles of Weibull populations, on the basis of the solution of a quadratic equation, is more accurate than current Monte Carlo tables and extends to any location-scale family. It is shown that this method is accurate for all members of the log gamma(K) family, where K = 1/2 to infinity, and works well for censored data, while also extending to regression data. An even more accurate procedure involving an approximation to the Lawless (1982) conditional procedure, with numerical integrations whose tables are independent of the data, is also presented. These methods are applied to the case of failure strengths of ceramic specimens from each of three billets of Si3N4, which have undergone flexural strength testing.

Jones, R. A.; Scholz, F. W.; Ossiander, M.; Shorack, G. R.

1985-01-01

269

Calibration Tests of a Japanese Log Rodmeter  

NASA Technical Reports Server (NTRS)

A Japanese log rodmeter of the rotating-vane impeller type, with a co mmutator on the impeller shaft, was calibrated in Langley tank no. 1. The rotational speed of two impellers was determined for forward speeds up to 24 knots at angles of yaw up to ?10 0 . In general, the rota tional speeds of two apparently identical impellers tested in the rod meter decreased with increasing yaw angle, right yaw causing a greate r decrease than left yaw. The difference in calibration between the t wo impellers was approximately the same as that produced by a change in yaw angle from 50 left to 50 right. Evidence of cavitation within the impeller fairing appeared at speeds above 24 knots.

Mottard, Elmo J.

1949-01-01

270

Sonic well logging tool longitudinal wave attenuator  

SciTech Connect

This patent describes an attenuator for use with a well logging tool in attenuating a wave propagating longitudinally along the tool when the tool is disposed in a borehole of an oil well. It comprises: a plurality of layers of a first material. The first material including metal washers; a plurality of layers of a second material interleaved with the plurality of layers of the first material. The second material including rubber-like washers; and an inner member. The interleaved rubber-like washers and metal washers being wrapped around the inner member. The inner member including an outwardly directed flange on which one end of the interleaved rubber-like washers and metal washers rest.

Wignall, A.H.; Hoyle, D.C.

1989-10-10

271

Simulation Control Graphical User Interface Logging Report  

NASA Technical Reports Server (NTRS)

One of the many tasks of my project was to revise the code of the Simulation Control Graphical User Interface (SIM GUI) to enable logging functionality to a file. I was also tasked with developing a script that directed the startup and initialization flow of the various LCS software components. This makes sure that a software component will not spin up until all the appropriate dependencies have been configured properly. Also I was able to assist hardware modelers in verifying the configuration of models after they have been upgraded to a new software version. I developed some code that analyzes the MDL files to determine if any error were generated due to the upgrade process. Another one of the projects assigned to me was supporting the End-to-End Hardware/Software Daily Tag-up meeting.

Hewling, Karl B., Jr.

2012-01-01

272

Methods of interpreting wireline logs in an igneous reservoir  

SciTech Connect

New interpretation methods were derived for log evaluation in a reservoir composed of igneous rock. The hydrocarbon reservoir studied was the fractured igneous basement rocks that produce in the Panhandle field in Texas. The need to locate concentrations of natural fractures, recognize petrographic differences, and possibly determine fracture mineralogy created the need for improved interpretation of existing standard logs. Logs used in this project were Dual Laterolog/Micro Spherically Focused Log, compensated neutron/lithodensity, density, natural gamma spectroscopy, continuous dipmeter, lithology analysis, oriented microresistivity, bond, and associated caliper logs. Many of the logs give similar information on reservoir parameters, but each provides uniquely useful data. Fracture occurrence can be determined from most of the logs, but a comparison of all logs yielded methods for qualitatively evaluating such features. With such a cross section of referenced data, they can better evaluate reservoir quality from fewer key logs, which reduces logging costs with no loss of understanding in evaluating a well. Completion procedures and costs can be better controlled in wells when the reservoir is more fully understood. Although the study focused on only one area, the basic observations should be applicable in similar areas.

Weimer, B.A.; Manwaring, M.S. (K. P. Exploration, Inc., Oklahoma City, OK (USA))

1987-02-01

273

An evaluation of the use of drillers' logs in lithologic studies of the Ogallala Formation of the southern high plains of Texas, progress report, 1970-71  

USGS Publications Warehouse

Logs made by water-well drillers were analyzed in conjunction with test-hole drilling and geophysical logging to evaluate usefulness of the driller's log in delineating areas that would be suitable for artificial recharge of the Ogallala Formation. This preliminary study indicates that lack of detailed and accurate information in many drillers' logs prevents their use as a reliable source of lithologic information. For many applications, such as evaluation of potential areas for artificial recharge, the value of more complete and more accurate information will be readily apparent as these applications become more widespread. More effort will be required in collecting lithologic information as part of the drilling operations.

Wilson, C. A.; Smith, J. T.; Thompson, G. L.; Sandeen, W. M.

1972-01-01

274

Analysis of geophysical well logs obtained in the State 2-14 borehole, Salton Sea geothermal area, California  

USGS Publications Warehouse

A complete suite of conventional geophysical well logs was obtained in the upper part of a 3220-m-deep borehole drilled into geothermally altered alluvial sediments on the southeastern edge of the Salton Sea. Geophysical logs obtained in the State 2-14 borehole indicate that neutron porosity, gamma-gamma, and deep-induction logs provide useful information on lithologic trends with depth. The natural gamma log contains almost continuous, high-frequency fluctuations that obscure lithologic trends and that may be related to recent radioisotope redistribution and departure from radiometric equilibrium. Acoustic transit time logs give unrealistically low in situ compressional velocities ranging from 1.8 to 3.0 km/s, whereas acoustic waveform logs indicate that sediment compressional velocities range from less than 3.0 km/s shallower than 1000 m in depth to almost 5.0 km/s at depths greater than 2000 m. Analyses indicate that most log values lie between two lithologic end points: an electrically conductive claystone with moderate neutron porosity, but no effective porosity, and an electrically nonconductive, fully cemented siltstone that has small but finite porosity. -from Authors

Paillet, F. L.; Morin, R. H.

1988-01-01

275

Log-normal censored regression model detecting prognostic factors in gastric cancer: A study of 3018 cases  

PubMed Central

AIM: To investigate the efficiency of Cox proportional hazard model in detecting prognostic factors for gastric cancer. METHODS: We used the log-normal regression model to evaluate prognostic factors in gastric cancer and compared it with the Cox model. Three thousand and eighteen gastric cancer patients who received a gastrectomy between 1980 and 2004 were retrospectively evaluated. Clinic-pathological factors were included in a log-normal model as well as Cox model. The akaike information criterion (AIC) was employed to compare the efficiency of both models. Univariate analysis indicated that age at diagnosis, past history, cancer location, distant metastasis status, surgical curative degree, combined other organ resection, Borrmann type, Lauren’s classification, pT stage, total dissected nodes and pN stage were prognostic factors in both log-normal and Cox models. RESULTS: In the final multivariate model, age at diagnosis, past history, surgical curative degree, Borrmann type, Lauren’s classification, pT stage, and pN stage were significant prognostic factors in both log-normal and Cox models. However, cancer location, distant metastasis status, and histology types were found to be significant prognostic factors in log-normal results alone. According to AIC, the log-normal model performed better than the Cox proportional hazard model (AIC value: 2534.72 vs 1693.56). CONCLUSION: It is suggested that the log-normal regression model can be a useful statistical model to evaluate prognostic factors instead of the Cox proportional hazard model.

Wang, Bin-Bin; Liu, Cai-Gang; Lu, Ping; Latengbaolide, A; Lu, Yang

2011-01-01

276

Color images of Kansas subsurface geology from well logs  

USGS Publications Warehouse

Modern wireline log combinations give highly diagnostic information that goes beyond the basic shale content, pore volume, and fluid saturation of older logs. Pattern recognition of geology from logs is made conventionally through either the examination of log overlays or log crossplots. Both methods can be combined through the use of color as a medium of information by setting the three color primaries of blue, green, and red light as axes of three dimensional color space. Multiple log readings of zones are rendered as composite color mixtures which, when plotted sequentially with depth, show lithological successions in a striking manner. The method is extremely simple to program and display on a color monitor. Illustrative examples are described from the Kansas subsurface. ?? 1986.

Collins, D. R.; Doveton, J. H.

1986-01-01

277

No-reference image quality assessment based on log-derivative statistics of natural scenes  

NASA Astrophysics Data System (ADS)

We propose an efficient blind/no-reference image quality assessment algorithm using a log-derivative statistical model of natural scenes. Our method, called DErivative Statistics-based QUality Evaluator (DESIQUE), extracts image quality-related statistical features at two image scales in both the spatial and frequency domains. In the spatial domain, normalized pixel values of an image are modeled in two ways: pointwise-based statistics for single pixel values and pairwise-based log-derivative statistics for the relationship of pixel pairs. In the frequency domain, log-Gabor filters are used to extract the fine scales of the image, which are also modeled by the log-derivative statistics. All of these statistics can be fitted by a generalized Gaussian distribution model, and the estimated parameters are fed into combined frameworks to estimate image quality. We train our models on the LIVE database by using optimized support vector machine learning. Experiment results tested on other databases show that the proposed algorithm not only yields a substantial improvement in predictive performance as compared to other state-of-the-art no-reference image quality assessment methods, but also maintains a high computational efficiency.

Zhang, Yi; Chandler, Damon M.

2013-10-01

278

Impact of fluid displacement effects on log-inject-log tests  

SciTech Connect

This paper evaluates the accuracy of long-inject-long (LIL) tests for oil deposits, analyzes the fluid-displacement behavior around the wellbore, discusses the transient behavior of pulsed-neutron-capture (PNC) logs before steady state is reached, and establishes the conditions under which LIL tests work best. This paper shows that both completion and reservoir properties affect the accuracy of LIL tests.

Pathak, P. (Atlantic Richfield Indonesia Inc. (ID))

1992-06-01

279

Western tight gas sands advanced logging workshop proceedings  

SciTech Connect

An advanced logging research program is one major aspect of the Western Tight Sands Program. Purpose of this workshop is to help BETC define critical logging needs for tight gas sands and to allow free interchange of ideas on all aspects of the current logging research program. Sixteen papers and abstracts are included together with discussions. Separate abstracts have been prepared for the 12 papers. (DLC)

Jennings, J B; Carroll, Jr, H B [eds.

1982-04-01

280

Algorithm for detecting defects in wooden logs using ground penetrating radar  

NASA Astrophysics Data System (ADS)

Presently there are no suitable non-invasive methods for precisely detecting the subsurface defects in logs in real time. Internal defects such as knots, decays, and embedded metals are of greatest concern for lumber production. While defects such as knots and decays (rots) are of major concern related to productivity and yield of high value wood products, embedded metals can damage the saw blade and significantly increase the down time and maintenance costs of saw mills. Currently, a large number of logs end up being discarded by saw mills, or result in low value wood products since they include defects. Nondestructive scanning of logs using techniques such as Ground Penetrating Radar (GPR) prior to sawing can greatly increase the productivity and yield of high value lumber. In this research, the GPR scanned data has been analyzed to differentiate the defective part of the wooden log from the good part. The location and size of the defect has been found in the GPR scanned data using the MATLAB algorithm. The output of this algorithm can be used as an input for generating operating instructions for a CNC sawing machine. This paper explains the advantages of the GPR technique, experimental setup and parameters used, data processing using RADAN software for detection of subsurface defects in logs, GPR data processing and analysis using MATLAB algorithm for automated defect detection, and comparison of results between the two processing methods. The results show that GPR in conjunction with the proposed algorithm provides a very promising technique for future on-line implementation in saw mills.

Devaru, Dayakar; Halabe, Udaya B.; Gopalakrishnan, B.; Agrawal, Sachin; Grushecky, Shawn

2005-11-01

281

Tracking the Inside Intruder Using Net Log on Debug Logging in Microsoft Windows Server Operating Systems  

SciTech Connect

In today's well-connected environments of the Internet, intranets, and extranets, protecting the Microsoft Windows network can be a daunting task for the security engineer. Intrusion Detection Systems are a must-have for most companies, but few have either the financial resources or the people resources to implement and maintain full-scale intrusion detection systems for their networks and hosts. Many will at least invest in intrusion detection for their Internet presence, but others have not yet stepped up to the plate with regard to internal intrusion detection. Unfortunately, most attacks will come from within. Microsoft Windows server operating systems are widely used across both large and small enterprises. Unfortunately, there is no intrusion detection built-in to the Windows server operating system. The security logs are valuable but can be difficult to manage even in a small to medium sized environment. So the question arises, can one effectively detect and identify an in side intruder using the native tools that come with Microsoft Windows Server operating systems? One such method is to use Net Logon Service debug logging to identify and track malicious user activity. This paper discusses how to use Net Logon debug logging to identify and track malicious user activity both in real-time and for forensic analysis.

Davis, CS

2004-01-20

282

Using a Log Analyser to Assist Research into Haptic Technology  

NASA Astrophysics Data System (ADS)

Usability evaluations collect subjective and objective measures. Examples of the latter are time to complete a task. The paper describes use cases of a log analyser for haptic feedback. The log analyser reads a log file and extracts information such as time of each practice and assessment session, analyses whether the user goes off curve and measures the force applied. A study case using the analyser is performed using a PHANToM haptic learning environment application that is used to teach young visually impaired students the subject of polynomials. The paper answers six questions to illustrate further use cases of the log analyser.

Jónsson, Fannar Freyr; Hvannberg, Ebba Þóra

283

Hydraulic parameters estimation from well logging resistivity and geoelectrical measurements  

NASA Astrophysics Data System (ADS)

In this paper, a methodology is suggested for deriving hydraulic parameters, such as hydraulic conductivity or transmissivity combining classical hydrogeological data with geophysical measurements. Estimates values of transmissivity and conductivity, with this approach, can reduce uncertainties in numerical model calibration and improve data coverage, reducing time and cost of a hydrogeological investigation at a regional scale. The conventional estimation of hydrogeological parameters needs to be done by analyzing wells data or laboratory measurements. Furthermore, to make a regional survey many wells should be considered, and the location of each one plays an important role in the interpretation stage. For this reason, the use of geoelectrical methods arises as an effective complementary technique, especially in developing countries where it is necessary to optimize resources. By combining hydraulic parameters from pumping tests and electrical resistivity from well logging profiles, it was possible to adjust three empirical laws in a semi-confined alluvial aquifer in the northeast of the province of Buenos Aires (Argentina). These relations were also tested to be used with surficial geoelectrical data. The hydraulic conductivity and transmissivity estimated in porous material were according to expected values for the region (20 m/day; 457 m2/day), and are very consistent with previous results from other authors (25 m/day and 500 m2/day). The methodology described could be used with similar data sets and applied to other areas with similar hydrogeological conditions.

Perdomo, S.; Ainchil, J. E.; Kruse, E.

2014-06-01

284

Petrophysical analysis of geophysical logs of the National Drilling Company-U.S. Geological Survey ground-water research project for Abu Dhabi Emirate, United Arab Emirates  

USGS Publications Warehouse

A program of borehole-geophysical logging was implemented to supply geologic and geohydrologic information for a regional ground-water investigation of Abu Dhabi Emirate. Analysis of geophysical logs was essential to provide information on geohydrologic properties because drill cuttings were not always adequate to define lithologic boundaries. The standard suite of logs obtained at most project test holes consisted of caliper, spontaneous potential, gamma ray, dual induction, microresistivity, compensated neutron, compensated density, and compensated sonic. Ophiolitic detritus from the nearby Oman Mountains has unusual petrophysical properties that complicated the interpretation of geophysical logs. The density of coarse ophiolitic detritus is typically greater than 3.0 grams per cubic centimeter, porosity values are large, often exceeding 45 percent, and the clay fraction included unusual clays, such as lizardite. Neither the spontaneous-potential log nor the natural gamma-ray log were useable clay indicators. Because intrinsic permeability is a function of clay content, additional research in determining clay content was critical. A research program of geophysical logging was conducted to determine the petrophysical properties of the shallow subsurface formations. The logging included spectral-gamma and thermal-decay-time logs. These logs, along with the standard geophysical logs, were correlated to mineralogy and whole-rock chemistry as determined from sidewall cores. Thus, interpretation of lithology and fluids was accomplished. Permeability and specific yield were calculated from geophysical-log data and correlated to results from an aquifer test. On the basis of results from the research logging, a method of lithologic and water-resistivity interpretation was developed for the test holes at which the standard suite of logs were obtained. In addition, a computer program was developed to assist in the analysis of log data. Geohydrologic properties were estimated, including volume of clay matrix, volume of matrix other than clay, density of matrix other than clay, density of matrix, intrinsic permeability, specific yield, and specific storage. Geophysical logs were used to (1) determine lithology, (2) correlate lithologic and permeable zones, (3) calibrate seismic reprocessing, (4) calibrate transient-electromagnetic surveys, and (5) calibrate uphole-survey interpretations. Logs were used at the drill site to (1) determine permeability zones, (2) determine dissolved-solids content, which is a function of water resistivity, and (3) design wells accordingly. Data and properties derived from logs were used to determine transmissivity and specific yield of aquifer materials.

Jorgensen, Donald G.; Petricola, Mario

1994-01-01

285

Efficient Preprocessing technique using Web log mining  

NASA Astrophysics Data System (ADS)

Web Usage Mining can be described as the discovery and Analysis of user access pattern through mining of log files and associated data from a particular websites. No. of visitors interact daily with web sites around the world. enormous amount of data are being generated and these information could be very prize to the company in the field of accepting Customerís behaviors. In this paper a complete preprocessing style having data cleaning, user and session Identification activities to improve the quality of data. Efficient preprocessing technique one of the User Identification which is key issue in preprocessing technique phase is to identify the Unique web users. Traditional User Identification is based on the site structure, being supported by using some heuristic rules, for use of this reduced the efficiency of user identification solve this difficulty we introduced proposed Technique DUI (Distinct User Identification) based on IP address ,Agent and Session time ,Referred pages on desired session time. Which can be used in counter terrorism, fraud detection and detection of unusual access of secure data, as well as through detection of regular access behavior of users improve the overall designing and performance of upcoming access of preprocessing results.

Raiyani, Sheetal A.; jain, Shailendra

2012-11-01

286

Herschel Observation Log (Herschel Science Centre, 2013)  

NASA Astrophysics Data System (ADS)

The Herschel Space Observatory (Herschel) is an ESA (European Space Agency) project with instruments funded by ESA member states. It was operated from May 2009 till April 2013, offering unprecedent observational capabilities in the far-infrared and submillimetre spectral range (55-671 microns). Herschel carried a 3.5m diameter passively cooled Cassegrain telescope. The science payload comprised three instruments: two direct detection cameras/medium resolution spectrometers, PACS and SPIRE, and a very high-resolution heterodyne spectrometer, HIFI. Herschel successfully made over 37,000 scientific observations. Herschel Science Archive: The HSA is available at the Herschel Science Centre at http://herschel.esac.esa.int/Science_Archive.shtml Herschel helpdesk: http://herschel.esac.esa.int/esupport/ Herschel User Provided Data Products: http://herschel.esac.esa.int/UserProvidedDataProducts.shtml Postcard Server: http://archives.esac.esa.int/hsa/aio/doc/postcardGallery.html Observation Log: http://herschel.esac.esa.int/logrepgen/observationlist.do (1 data file).

Herschel Science, Centre

2013-09-01

287

Saving big bucks with your log sheets  

SciTech Connect

This article speaks to a common problem in a lot of industrial and institutional boilerhouses. Most boilerhouses do an excellent job at collecting information. Circular chart recorders churn out pressures, temperatures, and flows for everything from steam to natural gas to city water consumption. At most facilities, this stuff all gets chucked into a drawer or file cabinet daily. Have you ever wondered why you collect and record what you do? What were people thinking when the existing logs were set up? This article attempts to challenge the original thought process and hopes to evoke in the reader a renewed vision of what should be collected, how, and then what can be done with it. The goal of this article is not to define new and expensive data acquisition or control system projects. It is instead to show how to develop systems that only require paper, pencils, and people who are motivated and care. These people are probably already being paid to do most of this work. Experience is that if these people are treated with respect and given some simple tools they will do amazing things beyond what was thought possible. This is a low-tech humanistic approach that has a fabulous rate of return. It`s also something that can be immediately implemented.

Puskar, J.R. [CEC Consultants, Inc., Cleveland, OH (United States)

1999-07-01

288

log(MPl/m3/2)  

SciTech Connect

Flux compactifications of string theory seem to require the presence of a fine-tuned constant in the superpotential. We discuss a scheme where this constant is replaced by a dynamical quantity which we argue to be a 'continuous Chern-Simons term'. In such a scheme, the gaugino condensate generates the hierarchically small scale of supersymmetry breakdown rather than adjusting its size to a constant. A crucial ingredient is the appearance of the hierarchically small quantity exp(-) which corresponds to the scale of gaugino condensation. Under rather general circumstances, this leads to a scenario of moduli stabilization, which is endowed with a hierarchy between the mass of the lightest modulus, the gravitino mass and the scale of the soft terms, mmodulus {approx} m3/2 {approx} 2 msoft. The 'little hierarchy' is given by the logarithm of the ratio of the Planck scale and the gravitino mass, {approx} log(MPl/m3/2) {approx} 4{pi}2. This exhibits a new mediation scheme of supersymmetry breakdown, called mirage mediation. We highlight the special properties of the scheme, and their consequences for phenomenology and cosmology.

Loaiza-Brito, Oscar; Martin, Johannes; Nilles, Hans Peter; Ratz, Michael [Physikalisches Institut, Universitaet Bonn, Nussallee 12, D-53115 Bonn (Germany)

2005-12-02

289

Lower Series of Subaerial Extruded Basalt, Faroe Islands, studied from Wire-Line Logs.  

NASA Astrophysics Data System (ADS)

On the Faroe Islands the basaltic cover has been penetrated and an extensive suite of wire-line logs represent 2480 m of Lower Basalt Series. The exposed part of the series constitutes subaerial extruded tholeitic aa basalt extruded in a rhythmic pattern. The flows consist of an upper crust, a massive core and a basal zone and may be separated by sediments. Aa flows show gradation from brecciated crust to unbrecciated core and the core is massive with few or no vesicles. Electrosequence analysis using workstation has been applied to the logs and a volcanic stratigraphy is established and the composition of the Lower Basalt Series examined. The logs representing physical properties: Calliper, RHOB (density), NPHI (porosity), Sonic (Compressional, Shear and Stonely waves) and resistivity show cyclic pattern that allows the division of flows into crust and core. The basal zone is to thin for recognisition by means of the logs acquired for this study. Transition from crust to core is gradual whereas the transition between the core and the crust/sedimentlayer below is very abrupt indicating the existence of a basal zone. Geochemical logs Spectral gamma, CGR, SGR and photoelectric do not show similar cyclic pattern. The SGR is of use to indicate flowunits due to the combined effect of the elements measured. Interbedded sedimentlayers are revealed mainly by Potassium, sonic transit times, NPHI and RHOB. The validity of the division into flowunits, crust, core, sedimentslayers, composite flows and intrusions is confirmed by petrophysical values.The overall log-pattern of the flows is similar but large variations within the core are found. Three main types of cores are identified 1) massive 2) gradually becoming more massive downwards 3) vesicular/fractured zones located at various levels. Crossplots and statistical analysis of the three types illustrate this. Type 3 is most frequent indicating that aa flows have more fractures/vesicules than previous thought.

Boldreel, L. O.

2003-04-01

290

PREDICTING SOIL SORPTION COEFFICIENTS OF ORGANIC CHEMICALS USING A NEURAL NETWORK MODEL  

EPA Science Inventory

The soil/sediment adsorption partition coefficient normalized to organic carbon (Koc) is extensively used to assess the fate of organic chemicals in hazardous waste sites. Several attempts have been made to estimate the value of Koc from chemical structure ...

291

Inflow and outflow signatures in flowing wellbore electrical conductivity logs  

SciTech Connect

Flowing wellbore electrical-conductivity logging provides a means to determine hydrologic properties of fractures, fracture zones, or other permeable layers intersecting a borehole in saturated rock. The method involves analyzing the time-evolution of fluid electrical-conductivity logs obtained while the well is being pumped and yields information on the location, hydraulic transmissivity, and salinity of permeable layers, as well as their initial (or ambient) pressure head. Earlier analysis methods were restricted to the case in which flows from the permeable layers or fractures were directed into the borehole. More recently, a numerical model for simulating flowing-conductivity logging was adapted to permit treatment of both inflow and outflow, including analysis of natural regional flow in the permeable layer. However, determining the fracture properties with the numerical model by optimizing the match to the conductivity logs is a laborious trial-and-error procedure. In this paper, we identify the signatures of various inflow and outflow features in the conductivity logs to expedite this procedure and to provide physical insight for the analysis of these logs. Generally, inflow points are found to produce a distinctive signature on the conductivity logs themselves, enabling the determination of location, inflow rate, and ion concentration in a straightforward manner. Identifying outflow locations and flow rates, on the other hand, can be done with a more complicated integral method. Running a set of several conductivity logs with different pumping rates (e.g., half and double the original pumping rate) provides further information on the nature of the feed points. In addition to enabling the estimation of flow parameters from conductivity logs, an understanding of the conductivity log signatures can aid in the design of follow-up logging activities.

Doughty, Christine; Tsang, Chin-Fu

2002-08-28

292

Logging and Fire Effects in Siberian Boreal Forests  

NASA Astrophysics Data System (ADS)

The Russian boreal zone supports a huge terrestrial carbon pool. Moreover, it is a tremendous reservoir of wood products concentrated mainly in Siberia. The main natural disturbance in these forests is wildfire, which modifies the carbon budget and has potentially important climate feedbacks. In addition, both legal and illegal logging increase landscape complexity and fire hazard. We investigated a number of sites in different regions of Siberia to evaluate the impacts of fire and logging on fuel loads, carbon emissions, tree regeneration, soil respiration, and microbocenosis. We found large variations of fire and logging effects among regions depending on growing conditions and type of logging activity. Partial logging had no negative impact on forest conditions and carbon cycle. Illegal logging resulted in increase of fire hazard, and higher carbon emissions than legal logging. The highest fuel loads and carbon emissions were found on repeatedly burned unlogged sites where first fire resulted in total tree mortality. Repeated fires together with logging activities in drier conditions and on large burned sites resulted in insufficient regeneration, or even total lack of tree seedlings. Soil respiration was less on both burned and logged areas than in undisturbed forest. The highest structural and functional disturbances of the soil microbocenosis were observed on logged burned sites. Understanding current interactions between fire and logging is important for modeling ecosystem processes and for managers to develop strategies of sustainable forest management. Changing patterns in the harvest of wood products increase landscape complexity and can be expected to increase emissions and ecosystem damage from wildfires, inhibit recovery of natural ecosystems, and exacerbate impacts of wildland fire on changing climate and air quality. The research was supported by NASA LCLUC Program, RFBR grant # 12-04-31258, and Russian Academy of Sciences.

Kukavskaya, E.; Buryak, L.; Ivanova, G.; Kalenskaya, O.; Bogorodskaya, A.; Zhila, S.; McRae, D.; Conard, S. G.

2013-12-01

293

Influence of Logging on the Effects of Wildfire in Siberia  

NASA Astrophysics Data System (ADS)

The Russian boreal zone supports a huge terrestrial carbon pool. Changes in this pool and related changes in land cover have global significance in terms of climate change. Moreover, it is a tremendous and largely untapped reservoir of wood products. The main natural disturbance in these forests is wildfire, which modifies the carbon budget and has potentially important climate feedbacks. In addition both legal and illegal logging are increasing in many forest areas of Siberia. From 2009 to 2012, we investigated a number of logged and unlogged sites to evaluate the impact of logging on wildfire characteristics and subsequent effects of wildfires on the ecosystem. The research was conducted in 3 different ecoregions of Siberia: taiga forest (Angara region), forest-steppe (Shushenskoe region), and mountain forest (Chita region). We analyzed fire effects in different forest types as a function of both the presence of logging and harvest methods. Logged areas often had higher fuel loads due to logging debris, and typically experienced higher severity fires than unlogged forests. We found large variations among sites depending on forest types, type of logging activity, and weather conditions prior to and during burning. Illegal logging resulted in much higher fire hazard than legal logging. Fuel consumption was highest on repeatedly burned areas, where ground cover was often burned to the mineral layer. Estimated carbon emissions were up to 5 times higher on logged areas than on unlogged sites. Soil respiration was less on both burned and logged areas than in undisturbed forest. Changing patterns in the harvest of wood products can be expected to increase the emissions and ecosystem damage from wildfires, inhibit recovery of natural ecosystems, and exacerbate impacts of wildland fire on changing climate and air quality. The research was supported by NASA LCLUC Program, RFBR grant # 12-04-31258, and Russian Academy of Sciences.

Kukavskaya, Elena; Ivanova, Galina; Buryak, Ludmilla; Kalenskaya, Olga; Bogorodskaya, Anna; Zhila, Sergey; McRae, Douglas; Conard, Susan

2013-04-01

294

A borehole corrected pulsed neutron well logging system  

Microsoft Academic Search

An improved well logging method has been developed for more accurately measuring the neutron capture cross section (Sigma) of earth formations. A measurement of Sigma with depth (well log) is useful in estimating hydrocarbon saturation of saline reservoirs. Gamma rays are detected following each burst of neutrons emitted by a pulsed 14 MeV neutron generator. An iterative procedure was developed

W. E. Schultz; H. D. Smith; J. L. Verbout; J. R. Bridges; G. H. Garcia

1985-01-01

295

Method and apparatus for gamma ray well logging  

Microsoft Academic Search

A radioactive logging source carried by a logging tool injects gamma rays into the formation. A detector generates a pulse for each gamma ray incident upon the detector having an amplitude proportional to the gamma ray energy. Electrical signals corresponding to each such amplitude are delivered to the surface. These incident gamma rays originate from the formation as well as

Hubner

1985-01-01

296

Correlation-based Document Clustering using Web Logs  

Microsoft Academic Search

A problem facing information retrieval on the web is how to effectively cluster large amounts of web documents. One approach is to cluster the documents based on information provided only by users' usage logs and not by the content of the documents. A major advantage of this approach is that the relevancy information is objectively reflected by the usage logs;

Zhong Su; Qiang Yang; Hongjiang Zhang; Xiaowei Xu; Yuhen Hu

2001-01-01

297

Mining Console Logs for Large-Scale System Problem Detection  

Microsoft Academic Search

The console logs generated by an application contain messages that the application developers believed would be useful in de- bugging or monitoring the application. Despite the ubiquity and large size of these logs, they are rarely exploited in a syste matic way for monitoring and debugging because they are not read- ily machine-parsable. In this paper, we propose a novel

Wei Xu; Ling Huang; Armando Fox; David A. Patterson; Michael I. Jordan

2008-01-01

298

33 CFR 207.370 - Big Fork River, Minn.; logging.  

Code of Federal Regulations, 2010 CFR

...Navigable Waters 3 2010-07-01 2010-07-01 false Big Fork River, Minn.; logging. 207.370 Section 207.370...DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.370 Big Fork River, Minn.; logging. (a) During the...

2010-07-01

299

33 CFR 207.370 - Big Fork River, Minn.; logging.  

Code of Federal Regulations, 2013 CFR

...Navigable Waters 3 2013-07-01 2013-07-01 false Big Fork River, Minn.; logging. 207.370 Section 207.370...DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.370 Big Fork River, Minn.; logging. (a) During the...

2013-07-01

300

33 CFR 207.370 - Big Fork River, Minn.; logging.  

Code of Federal Regulations, 2010 CFR

...Navigable Waters 3 2009-07-01 2009-07-01 false Big Fork River, Minn.; logging. 207.370 Section 207.370...DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.370 Big Fork River, Minn.; logging. (a) During the...

2009-07-01

301

6. View to north along dirt lane. Log shed (HABS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. View to north along dirt lane. Log shed (HABS No. VA-1290-N) at left, log dogtrot tenant house (HABS No. VA-1290-Q) in distance at end of lane. - Edgewood Farm, West side of State Route 600, .8 mile north of State Route 778, Clover, Halifax County, VA

302

Estimating log models: to transform or not to transform?  

Microsoft Academic Search

Health economists often use log models to deal with skewed outcomes, such as health utilization or health expenditures. The literature provides a number of alternative estimation approaches for log models, including ordinary least-squares on ln(y) and generalized linear models. This study examines how well the alternative estimators behave econometrically in terms of bias and precision when the data are skewed

Willard G. Manning; John Mullahy

2001-01-01

303

22. VIEW OF DEBARKER FROM LOG INFEED DECK. NOTE ROOF ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. VIEW OF DEBARKER FROM LOG IN-FEED DECK. NOTE ROOF SUPPORT OVER CARRIAGE AND LOG IN-FEED DECK IN UPPER RIGHT. (SEE OR-89-18 AND OR-89-23 FOR RELATED ARCHITECTURAL DETAILS.) - Hull-Oakes Lumber Company, 23837 Dawson Road, Monroe, Benton County, OR

304

47 CFR 73.1840 - Retention of logs.  

Code of Federal Regulations, 2013 CFR

...until specifically authorized in writing by the FCC to destroy them. Logs incident to or involved in any claim or complaint...made. (4) Copies of any log required to be filed with any application; or placed in the station's local...

2013-10-01

305

46 CFR 78.37-10 - Official log entries.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Official log entries. 78.37-10 Section 78...Logbook Entries § 78.37-10 Official log entries. (a) In addition to other items required to be entered in the official logbook on every...

2013-10-01

306

VIEW OF DEBARKER FROM LOG INFEED DECK. NOTE ROOF SUPPORT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF DEBARKER FROM LOG IN-FEED DECK. NOTE ROOF SUPPORT OVER CARRIAGE AND LOG IN-FEED DECK IN UPPER RIGHT. (SEE OR-89-18 AND OR-89-23 FOR RELATED ARCHITECTURAL DETAILS.) - Hull-Oakes Lumber Company, 23837 Dawson Road, Monroe, Benton County, OR

307

46 CFR 148.100 - Log book entries.  

Code of Federal Regulations, 2013 CFR

... Shipping 5 2013-10-01 2013-10-01 false Log book entries. 148.100 Section 148.100 Shipping COAST...HANDLING Minimum Transportation Requirements § 148.100 Log book entries. During the transport in bulk of a material...

2013-10-01

308

The effects of logging and disease on American chestnut  

Microsoft Academic Search

Disturbance histories drive spatiotemporal patterns of species distributions, and multiple disturbances can have complex effects on these patterns of distribution. The introduction of the chestnut blight (Cryphonectria parasitica (Murril.) Barr.) to the eastern United States in the early 1900s coincided with an increase in logging, thus presenting an ideal situation for studying the effect of two disturbance events, logging and

Katie L. Burke

2011-01-01

309

A RAPID METHOD FOR ESTIMATING LOG P FOR ORGANIC CHEMICALS  

EPA Science Inventory

The logarithm of the retention time (log RT) of organic chemicals on a permanently bonded (C-18) reverse-phase high-pressure liquid chromatography system is shown to be linearly related to the logarithm of the n-octanol/water partition coefficient (log P). A rapid, inexpensive te...

310

Comparison between moving and stationary transmitter systems in induction logging  

Microsoft Academic Search

In a general treatment of the theory of induction logging, an exact integral representation has been obtained for the mutual impedance between a vertical dipole transmitter and a coaxial dipole receiver in a three layered earth. Based on this representation, a computer model has been devised using the traditional Slingram system of induction logging and the comparatively new Turam system,

M. Poddar; P. Caleb Dhanasekaran; K. Prabhakar Rao

1985-01-01

311

Recovery in Distributed Systems Using Optimistic Message Logging and Checkpointing  

Microsoft Academic Search

In a distributed system using message logging and checkpointing to provide fault tolerance, there is always a unique maximum recoverable system state, regardless of the message logging protocol used. The proof of this relies on the observation that the set of system states that have occurred during any single execution of a system forms a lattice, with the sets of

David B. Johnson; Willy Zwaenepoel

1990-01-01

312

Recovery in Distributed Systems Using Optimistic Message Logging and Checkpointing  

Microsoft Academic Search

In a distributed system using message logging andcheckpointing to provide fault tolerance, there isalways a unique maximum recoverable system state,regardless of the message logging protocol used. Theproof of this relies on the observation that the set ofsystem states that have occurred during any singleexecution of a system forms a lattice, with the setsof consistent and recoverable system states as sublattices.The

David B. Johnson; Willy Zwaenepoel

1988-01-01

313

Multiscale and Wavelet Transform with Applications in Well LOG Analysis.  

National Technical Information Service (NTIS)

Theoretical concepts and applications of the multiscale transform and the wavelet transform are discussed with attention given to well logs. A well log is a sequence of measures obtained from a borehole and a record of the variation in lithology. As part ...

P. L. Vermeer

1992-01-01

314

Linear Discriminant Analysis and Discriminative Log-linear Modeling  

Microsoft Academic Search

We discuss the relationship between the discriminative training of Gaussian models and the maximum entropy framework for log-linear models. Observing that linear transforms leave the distributions resulting from the log- linear model unchanged, we derive a discriminative linear feature reduction technique from the maximum entropy ap- proach and compare it to the well-known linear discrimi- nant analysis. From experiments on

Daniel Keysers; Hermann Ney

2004-01-01

315

A Log-polar Image Processing System on a Chip  

Microsoft Academic Search

This paper deals with the implementation, in a high density reprogrammable device, of a complete log-polar image processing system. The log-polar vision reduces the amount of data to be processed and simplifies several vision algorithms, making it possible the implementation of a complete processing system on a single chip. The image processing system has a conversion module from cartesian to

Fernando Pardo; Jose A. Boluda; Julio C. Sos

316

Comparative Analysis of ASCII and XML Logging Systems.  

National Technical Information Service (NTIS)

This research compares XML and ASCII based event logging systems in terms of their storage and processing efficiency. XML has been an emerging technology, even for security. Therefore, it is researched as a logging system with the mitigation of its verbos...

E. Hanington

2010-01-01

317

Log Bucking and Lumber Manufacturing Using Dynamic Programming  

Microsoft Academic Search

The process of converting a tree into finished lumber involves several interrelated steps. The two of greatest potential for improvement are cutting the felled tree into shorter logs (called bucking the tree) and sawing the bucked logs into lumber. Unlike previous work in the area, this paper considers the two activities together as a single production system. The model allows

Bruce Faaland; David Briggs

1984-01-01

318

Needs of well logging industry in new nuclear detectors  

Microsoft Academic Search

In this paper we discuss some challenges of nuclear well logging related to the lack of the gamma ray and neutron detection technologies capable of operating reliably in the down-hole hostile environment. Different nuclear well logging techniques are described, the parameters of nuclear detectors which would satisfy the requirements imposed by these techniques are considered, and the results of the

Anton Nikitin; Steven Bliven

2010-01-01

319

Condition and fate of logged forests in the Brazilian Amazon  

PubMed Central

The long-term viability of a forest industry in the Amazon region of Brazil depends on the maintenance of adequate timber volume and growth in healthy forests. Using extensive high-resolution satellite analyses, we studied the forest damage caused by recent logging operations and the likelihood that logged forests would be cleared within 4 years after timber harvest. Across 2,030,637 km2 of the Brazilian Amazon from 1999 to 2004, at least 76% of all harvest practices resulted in high levels of canopy damage sufficient to leave forests susceptible to drought and fire. We found that 16 ± 1% of selectively logged areas were deforested within 1 year of logging, with a subsequent annual deforestation rate of 5.4% for 4 years after timber harvests. Nearly all logging occurred within 25 km of main roads, and within that area, the probability of deforestation for a logged forest was up to four times greater than for unlogged forests. In combination, our results show that logging in the Brazilian Amazon is dominated by highly damaging operations, often followed rapidly by deforestation decades before forests can recover sufficiently to produce timber for a second harvest. Under the management regimes in effect at the time of our study in the Brazilian Amazon, selective logging would not be sustained.

Asner, Gregory P.; Broadbent, Eben N.; Oliveira, Paulo J. C.; Keller, Michael; Knapp, David E.; Silva, Jose N. M.

2006-01-01

320

Prediction of Log "P": ALOGPS Application in Medicinal Chemistry Education  

ERIC Educational Resources Information Center

Molecular hydrophobicity (lipophilicity), usually quantified as log "P" where "P" is the partition coefficient, is an important molecular characteristic in medicinal chemistry and drug design. The log "P" coefficient is one of the principal parameters for the estimation of lipophilicity of chemical compounds and pharmacokinetic properties. The…

Kujawski, Jacek; Bernard, Marek K.; Janusz, Anna; Kuzma, Weronika

2012-01-01

321

Experimental correlation between the p Ka value of sulfonphthaleins with the nature of the substituents groups  

NASA Astrophysics Data System (ADS)

This work presents the results obtained from a spectrophotometry study performed on some indicators of the sulfonphtaleins like phenol red (PR), thymol blue (TB), bromothymol blue (BTB), xylenol orange (XO) and methylthymol blue (MTB). During the first stage the acidity constants of some of the indicators were determined using the data from spectrophotometry, potentiometry and with the use of the software SQUAD. These were as follows: for the equilibrium 2H + BTB ? H 2BTB, log ?2 = 15.069 ± 0.046 and for H + BTB ? HBTB, log ?1 = 8.311 ± 0.044. For the XO and the MTB five values were calculated for each, namely, for MTB: log ?5 = 42.035, log ?4 = 38.567 ± 0.058, log ?3 = 32.257 ± 0.057, log ?2 = 23.785 ± 0.057, and log ?1 = 12.974 ± 0.045 while for XO: log ?5 = 40.120 ± 0.102, log ?4 = 35.158 ± 0.062, log ?3 = 29.102 ± 0.053, log ?2 = 21.237 ± 0.044, and log ?1 = 11.682 ± 0.044. During the second stage, a study was conducted on the effect of the substituents present in the indicators to determine the effect of different functional groups on the p Ka value corresponding to the last indicator's dissociation.

Balderas-Hernández, Patricia; Ramírez-Silva, María Teresa; Romero-Romo, Mario; Palomar-Pardavé, Manuel; Roa-Morales, Gabriela; Barrera-Diaz, Carlos; Rojas-Hernández, Alberto

2008-04-01

322

Coal log pipeline research at the University of Missouri  

SciTech Connect

Project tasks: Perform the necessary testing and development to demonstrate that the amount of binder in coal logs can be reduced to 8% or lower to produce logs with adequate strength to eliminate breakage during pipeline transportation, under conditions experienced in long distance pipeline systems. Prior to conducting any testing and demonstration, grantee shall perform an information search and make full determination of all previous attempts to extrude or briquette coal, upon which the testing and demonstration shall be based. Perform the necessary development to demonstrate a small model of the most promising injection system for coal-logs, and test the logs produced from Task 1. Conduct economic analysis of coal-log pipeline, based upon the work to date. Refine and complete the economic model. Prepare a final report for DOE.

Liu, H.

1992-03-01

323

Combined biological and ozone treatment of log yard run-off  

Microsoft Academic Search

Batch biological treatment of log yard run-off reduced biochemical oxygen demand (BOD), chemical oxygen demand (COD) and tannin and lignin (TL) concentration by 99%, 80%, and 90%, respectively. Acute (Microtox) toxicity was decreased over treatment, from an initial EC50 of 1.83% to a value of 50.4% after 48h of treatment. Kinetics of biodegradation were determined using respirometry and fitted using

Michael G Zenaitis; Harinder Sandhu; Sheldon J. B Duff

2002-01-01

324

Characteristic fuel consumption and exhaust emissions in fully mechanized logging operations  

Microsoft Academic Search

A study was done using eight different logging machines (harvesters and forwarders) in clear-felling operations to quantify\\u000a the associated fuel consumption, and to define the inherent relationship between engine output power and fuel consumption.\\u000a Exhaust emissions were also calculated on the basis of mean fuel consumption values, obtained by measurements, and from the\\u000a developed regression and correlation model for diesel

Radomir Klvac; Alois Skoupy

2009-01-01

325

The behaviour of log phase Escherichia coli at temperatures below the minimum for sustained growth  

Microsoft Academic Search

The behaviour of cold-adapted, log phase Escherichia coli broth cultures during incubation at 2°C or 6°C for upto 8 days, and during subsequent incubation at 12°C, was determined by measurement of absorbance values at 600 nm (A600), enumeration of colony forming units (cfu) on plate count agar (PCA) and violet red bile agar (VRBA), and measurement of the length of

T Jones; C. O Gill; L McMullen

2002-01-01

326

PLACE VALUE  

NSDL National Science Digital Library

DESK Standard: Identify the place and value of a given digit in a five-digit numeral, including decimals to the tenths. . DATES: You can begin this activity on October 2. You should complete it by October 6. OBJECTIVE: We have been studying place value skills this year, and now you have a chance to review what you have learned. You will visit a variety of fun Web sites ...

Hughes, Mr.

2006-03-09

327

Dynamical evolution of active detached binaries on the logJo-logM diagram and contact binary formation  

NASA Astrophysics Data System (ADS)

Orbital angular momentum (OAM, Jo), systemic mass (M) and orbital period (P) distributions of chromospherically active binaries (CAB) and W Ursae Majoris (W UMa) systems were investigated. The diagrams of and logJo-logM were formed from 119 CAB and 102 W UMa stars. The logJo-logM diagram is found to be most meaningful in demonstrating dynamical evolution of binary star orbits. A slightly curved borderline (contact border) separating the detached and the contact systems was discovered on the logJo-logM diagram. Since the orbital size (a) and period (P) of binaries are determined by their current Jo, M and mass ratio, q, the rates of OAM loss (dlogJo/dt) and mass loss (dlogM/dt) are primary parameters to determine the direction and the speed of the dynamical evolution. A detached system becomes a contact system if its own dynamical evolution enables it to pass the contact border on the logJo-logM diagram. The evolution of q for a mass-losing detached system is unknown unless the mass-loss rate for each component is known. Assuming q is constant in the first approximation and using the mean decreasing rates of Jo and M from the kinematical ages of CAB stars, it has been predicted that 11, 23 and 39 per cent of current CAB stars would transform to W UMa systems if their nuclear evolution permits them to live 2, 4 and 6 Gyr, respectively.

Eker, Z.; Demircan, O.; Bilir, S.; Karata?, Y.

2006-12-01

328

An {Omega}({radical}log log n) lower bound for routing in optical networks  

SciTech Connect

Optical communication is likely to significantly speed up parallel computation because the vast bandwidth of the optical medium can be divided to produce communication networks of very high degree. However, the problem of contention in high-degree networks makes the routing problem in these networks theoretically (and practically) difficult. In this paper we examine Valiant`s h-relation routing problem, which is a fundamental problem in the theory of parallel computing. The h-relation routing problem arises both in the direct implementation of specific parallel algorithms on distributed-memory machines and in the general simulation of shared memory models such as the PRAM on distributed-memory machines. In an h-relation routing problem each processor has up to h messages that it wishes to send to other processors and each processor is the destination of at most h messages. We present a lower bound for routing an h-relation (for any h > 1) on a complete optical network of size -n. Our lower bound applies to any randomized distributed algorithm for this task. Specifically, we show that the expected number of communication steps required to route an arbitrary h-relation is {Omega}(h + {radical}log log n). This is the first known lower bound for this problem which does not restrict the class of algorithms under consideration.

Goldberg, L.A. [Sandia National Labs., Albuquerque, NM (United States); Jerrum, M. [Edinburgh Univ. (United Kingdom). Dept. of Computer Science; MacKenzie, P.D. [Texas Univ., Austin, TX (United States). Dept. of Computer Sciences

1993-11-06

329

Application of BI (Bioturbation Index) Log in Interpreting Sedimentary Record  

NASA Astrophysics Data System (ADS)

Various BI (bioturbation index) schemes have been developed since early 60's to semi-quantitatively measure the degree of bioturbation in sediments. Although BI scheme has been used as a paleo-oxygen proxy in fine- grained basinal strata, its wider application remained under-explored. Like geophysical wireline logs, a continuous line curve of BI can be plotted against the thickness of a sedimentary succession. This `BI log' characterizing the variation of bioturbation intensity down to the bed/lamina-scale can be generated in outcrops, and from cores and FMI (formation micro-imager) logs. The application of BI log in interpreting sedimentary record is diverse. Five basic trends of BI log (uniform and low, uniform and high, non-uniform, upward-decreasing, and upward-increasing) can be recognized, each indicating a distinct paleo-environmental condition, either persistent or changing, for trace makers. These trends can be used as proxies for sedimentation rate, dominant energy (wave, tide, and river), and/or paleoclimate (oxygen, salinity, temperature, and organic carbon). For example, BI logs of shallow marine and transitional strata show distinct trends depending on the relative influence of rivers, waves, storms, and tides. Characteristic deflections of BI log across lithostratigraphic boundaries, key sequence stratigraphic surfaces, and across depositional systems are observed. BI log can also be used relatively as an indicator of reservoir property (porosity and permeability), particularly for `tight' reservoirs. When co-interpreted with other ichnological, sedimentological and geochemical data, BI log can be a powerful tool in various disciplines, such as sedimentology, paleoclimatology, stratigraphy, and petroleum geology.

Gani, M. R.

2006-12-01

330

Application of cased-hole logs to reservoir management  

SciTech Connect

Cased-hole electric wireline logs can be useful for diagnosing well problems as well as assuring optimum application of clearly defined remedial work. These logs are carefully run directly opposite points of fluid entry into the borehole. When used appropriately, interpretation is facilitated, and their subsequent application to well problems often yield positive results. The data obtained offer more definitive and more complete understanding of the production trends and the reservoir behavior. This work illustrates the interpretation and the appropriate use of various logs for identifying gas and water production problems in oil reservoirs. Examples as encountered in the Niger Delta are discussed.

Olarunsola, A.O.; Ekpo, E.U.

1984-04-01

331

Geothermal well log interpretation state of the art. Final report  

SciTech Connect

An in-depth study of the state of the art in Geothermal Well Log Interpretation has been made encompassing case histories, technical papers, computerized literature searches, and actual processing of geothermal wells from New Mexico, Idaho, and California. A classification scheme of geothermal reservoir types was defined which distinguishes fluid phase and temperature, lithology, geologic province, pore geometry, salinity, and fluid chemistry. Major deficiencies of Geothermal Well Log Interpretation are defined and discussed with recommendations of possible solutions or research for solutions. The Geothermal Well Log Interpretation study and report has concentrated primarily on Western US reservoirs. Geopressured geothermal reservoirs are not considered.

Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

1980-01-01

332

Fluid-temperature logs for selected wells in eastern Washington  

SciTech Connect

This Open-File Report consists of fluid temperature logs compiled during studies of the geohydrology and low temperature geothermal resources of eastern Washington. The fluid temperature logs are divided into two groups. Part A consists of wells which are concentrated in the Moses Lake-Ritzville-Connell area. Full geophysical log suites for many of these wells are presented in Stoffel and Widness (1983) and discussed in Widness (1983, 1984). Part B consists of wells outside of the Moses Lake-Ritzville-Connell study area.

Stoffel, K.L.; Widness, S. (comps.)

1983-12-01

333

Redeeming Value.  

ERIC Educational Resources Information Center

Presents an essay on organizational transformation and the way successful marketing transformations redeem a sense of value. Focuses on challenges faced by not-for-profit institutions, current changes in the library profession, and implications of the American Library Association's Goal 2000. A sidebar summarizes an interview with the director of…

Whitwell, Stuart C. A.

1995-01-01

334

Place Value  

NSDL National Science Digital Library

The answers to these FAQ from the Teacher2Teacher service at The Math Forum @ Drexel contain many suggestions for providing students with practice on using place value skills. They include ideas contributed by T2T Associates and teacher participants. There are links to Ask Dr. Math resources, children's literature connections, and outside websites with related resources.

Math Forum, Teacher2Teacher FAQ; The Math Forum @ Drexel

2000-01-01

335

Quality measures for geostatistical prediction of log-normal soil properties.  

NASA Astrophysics Data System (ADS)

A signature of non-linear processes in the soil is the non-normal distribution of soil properties. A common non-normal distribution is the log-normal, in which the variable Z can be transformed to a variable with a normal distribution by Y = log e(Z). Log-normal variables are common in soil geochemistry and hydrology. It is standard practice in geostatistics to use the log-transformation for such variables before spatial modelling and prediction, and there are procedures to back-transform predictions of Y to the original scale of measurement Z. This is important because values on the original scale are commonly required either for scientific purposes or for practical applications such as the assessment of potential contaminant concentrations in soil. One of the strengths of geostatistics is that geostatistical prediction returns a prediction error variance. Furthermore, this variance can be computed before a survey is undertaken, for a range of possible different sampling networks, since it depends only on the disposition of sample sites, and the variogram model of spatial dependence. This allows the most efficient network to be selected: one which will provide estimates of sufficient precision (where the prediction error variances are within acceptable bounds) without over-sampling. In log-normal kriging the prediction error variance depends not only on the variogram and the sampling array, but also on the conditional mean value of the variable, which is not known until after sampling. This means that the usual pre-survey quality measures which can be computed to guide the planning of geostatistical surveys are not available for log-normal variables. Given that many critical variables, such as contaminant concentrations, are often log-normally distributed, this is a serious gap in the capablity of geostatistics to facilitate rational sampling design for environmental management and monitoring. In this paper I propose and demonstrate some quality measures that can be computed, pre-survey, for different sampling networks for log-normal variables. I propose measures that are suitable both for point kriging, when predictions are obtained for the same sample support as the observations, and for block kriging when the predictions are upscaled to a region, such as a management unit or a regular block. The quality measures are dimensionless prediction intervals, scaled relative to the unknown median value of the target conditional distribution. In the point kriging case the distribution of interest is the conditional distribution of the variable at the target location. In the block kriging case the distribution is that of the spatial median value over the block. These quality measures are illustrated in a case study on the spatial variability of some critical metals and metalloids in the soil of eastern England. Target values of the quality measures are defined in terms of the requirements that land managers or regulators may specify for uncertainty in final predictions, and the sampling effort required to meet these is computed.

Lark, R. M.

2012-04-01

336

A Matrix Approach to Log-Linear Analysis Using SAS\\/IML  

Microsoft Academic Search

This work involves a matrix algebra approach to log-linear data analysis using SAS\\/IML. Consider the log-linear model: log(m) = ? ? = X. The Maximum Likelihood Estimator for m , m , is found. Suppose we are interested in the log odds ratios and the variance\\/covariance matrix associated with the log odds ratios. The terms get very messy. It makes

Paul Johnson

1994-01-01

337

56. LOOKING WEST AT CONCRETE TUNNEL DIVERING LOG POND OUTFLOW ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

56. LOOKING WEST AT CONCRETE TUNNEL DIVERING LOG POND OUTFLOW AWAY FROM SAWMILL SUPPORTS. PHOTOGRAPHER: UNKNOWN. DATE: 1954. COURTESY OF RALPH HULL. - Hull-Oakes Lumber Company, 23837 Dawson Road, Monroe, Benton County, OR

338

13. VIEW OF LOG BRIDGE (LATER SUPERSEDED BY THE WIREROPE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. VIEW OF LOG BRIDGE (LATER SUPERSEDED BY THE WIRE-ROPE SUSPENSION BRIDGE), SHOWING OVERHANG WHERE ROCK WAS BLASTED OUT, LOOKING NORTHEAST - Goat Trail Mining Road, Highway 20, 1.5 miles North of Newhalem, Newhalem, Whatcom County, WA

339

14. VIEW OF LOG BRIDGE (LATER SUPERSEDED BY THE WIREROPE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. VIEW OF LOG BRIDGE (LATER SUPERSEDED BY THE WIRE-ROPE SUSPENSION BRIDGE), SHOWING OVERHANG WHERE ROCK WAS BLASTED OUT, LOOKING SOUTHWEST - Goat Trail Mining Road, Highway 20, 1.5 miles North of Newhalem, Newhalem, Whatcom County, WA

340

5. VIEW OF SITE, AREA B; LOG BUILDING AND BUNKHOUSE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW OF SITE, AREA B; LOG BUILDING AND BUNKHOUSE (Features 9 and 10) AT FAR LEFT AND HOUSE (Feature 13) AT CENTER (n.d.) - Gold Dust Mine, Mill & Camp Complex, Wards Gulch, Salmon, Lemhi County, ID

341

Automation of PUSPATI Triga reactor's daily operation log book.  

National Technical Information Service (NTIS)

This paper discusses the computerization of nuclear reactor parameters, where the daily reactor operation log book was produced automatically. It uses microprocessor 80386 based microcomputers, analog input interface cards, and MC5.1 programming language.

Mohamad Idris Taib

1994-01-01

342

2. SOUTHWEST CORNER DETAIL, SHOWING LOG CONSTRUCTION AND DIAGONAL STONE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. SOUTHWEST CORNER DETAIL, SHOWING LOG CONSTRUCTION AND DIAGONAL STONE PATTERN IN CHINKING - Charles Wollerton House, Valley Creek & Sunset Hollow Roads vicinity (East Bradford Township), Downingtown, Chester County, PA

343

Solar-A reformatted data files and observing log  

NASA Technical Reports Server (NTRS)

An overview is presented of the Solar-A telemetry data files which are to be created and the format and organization which the files are to use. The organization chosen is to be efficient in space, to facilitate access to the data, and to allow the data to be transportable to different machines. An observing log file is to be created automatically, using the reformatted data files as the input. It will be possible to perform searches with the observing log to list cases where instruments are in certain modes and/or seeing certain signal levels. A user will be able to search the observing log and obtain a list of all cases where a given set of conditions are satisfied. An event log will be created listing the times when the instrument or spacecraft modes change.

Morrison, M. D.; Lemen, J. R.; Acton, L. W.; Bentley, R. D.; Kosugi, T.; Tsuneta, S.; Ogawara, Y.; Watanabe, T.

1991-01-01

344

Geothermal Well Log Interpretation State of the Art. Final Report.  

National Technical Information Service (NTIS)

An in-depth study of the state of the art in Geothermal Well Log Interpretation has been made encompassing case histories, technical papers, computerized literature searches, and actual processing of geothermal wells from New Mexico, Idaho, and California...

S. K. Sanyal L. E. Wells R. E. Bickham

1980-01-01

345

Log-Periodic Array of Monopole-Slot Elements.  

National Technical Information Service (NTIS)

In feeding a log-periodic monopole or slot array, excess line must be used between radiating elements to achieve proper phasing for backfire radiation. Discontinuities presented by the radiating elements, which are approximately one-half wavelength apart ...

D. J. Tammen P. E. Mayes

1987-01-01

346

3. View of corner connecting log section to north section ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. View of corner connecting log section to north section of building. LOOKING SOUTHEAST. - Department of Energy, Grand Junction Office, Building No. 12, 2597 B3/4 Road, Grand Junction, Mesa County, CO

347

16. VIEW OF UNIDENTIFIED MEN STANDING ON LOG BRIDGE ALONG ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. VIEW OF UNIDENTIFIED MEN STANDING ON LOG BRIDGE ALONG UNIDENTIFIED SECTION OF GOAT TRAIL MINING ROAD - Goat Trail Mining Road, Highway 20, 1.5 miles North of Newhalem, Newhalem, Whatcom County, WA

348

Determination of lithology from well logs using a neural network  

SciTech Connect

The authors have developed a computer program to automatically determine lithologies from well logs using a back-propagation neural network. Unlike a conventional serial computer, a neural network is a computational system composed of nodes (sometimes called neurons, neurodes, or units) and the connections between these nodes. Neural computing attempts to emulate the functions of the mammalian brain, thus mimicking thought processes. The neural network approach differs from previous pattern recognition methods in its ability to learn from examples. Unlike conventional statistical methods, this new approach does not require sophisticated mathematics and a large amount of statistical data. This paper discusses the application of neural networks to a pattern recognition problem in geology: the determination of lithology from well logs. The neural network determined the lithologies (limestone, dolomite, sandstone, shale, sandy and dolomitic limestones, sandy dolomite, and shale sandstone) from selected well logs in a fraction of the time required by an experienced human log analyst.

Rogers, S.J.; Fang, J.H. (Univ. of Alabama, Tuscaloosa (United States)); Karr, C.L.; Stanley, D.A. (Bureau of Mines, Tuscaloosa, AL (United States))

1992-05-01

349

Optimized Hypergraph Clustering-based Network Security Log Mining*  

NASA Astrophysics Data System (ADS)

With network's growth and popularization, network security experts are facing bigger and bigger network security log. Network security log is a kind of valuable and important information recording various network behaviors, and has the features of large-scale and high dimension. Therefore, how to analyze these network security log to enhance the security of network becomes the focus of many researchers. In this paper, we first design a frequent attack sequencebased hypergraph clustering algorithm to mine the network security log, and then improve this algorithm with a synthetic measure of hyperedge weight and two optimization functions of clustering result. The experimental results show that the synthetic measure and optimization functions can promote significantly the coverage and precision of clustering result. The optimized hypergraph clustering algorithm provides a data analyzing method for intrusion detecting and active forewarning of network.

Che, Jianhua; Lin, Weimin; Yu, Yong; Yao, Wei

350

11. Detail of log cribbing on north side of Pentagon ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. Detail of log cribbing on north side of Pentagon 1, (note stone in left foreground). View to south. - Pentagon Site, Pentagon 1, West of Barry's Landing off Highway 37, Fort Smith, Big Horn County, MT

351

15. Detail of log cribbing on southeast side of Pentagon ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. Detail of log cribbing on southeast side of Pentagon 1 (note stone in center). View to northwest. - Pentagon Site, Pentagon 1, West of Barry's Landing off Highway 37, Fort Smith, Big Horn County, MT

352

3. VIEW OF TUNNEL INTAKE, WITH LOG TRASH RACK, LOOKING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. VIEW OF TUNNEL INTAKE, WITH LOG TRASH RACK, LOOKING SOUTH - High Mountain Dams in Upalco Unit, Farmers Lake Tunnel, Ashley National Forest, 5.7 miles North of Swift Creek Campground, Mountain Home, Duchesne County, UT

353

Evaluation of Potash Grade with Gamma-ray Logs  

USGS Publications Warehouse

Potassium is an emitter of gamma-ray radiation, consequently deposits of potash can be detected and evaluated using gamma-ray logs. A method originally designed to evaluate uranium deposits in boreholes can also be applied to potash deposits. The method equates the depth-integral of a gamma-ray log to the grade-thickness product of a potash-bearing bed or series of beds. The average grade of a bed is then determined by dividing by the overall bed thickness, which can also be obtained from the gamma-ray log. The method was tested using gamma-ray logs and potash assays from boreholes near Carlsbad, New Mexico.

Nelson, Philip H.

2007-01-01

354

Heuristic search method for optimal zonation of well logs  

SciTech Connect

Optimal zonation of well-log data, that is, determining an optimal number of major segments such as waveforms in a log, may be achieved by employing a criterion of minimum variance (within a segment) and a heuristic search of potential boundary (link) points of digitized log data. This new method is based on an algorithm originally devised by D.M. Hawkins and D.F. Merriam in 1973. Their method can be improved by introducing a heuristic search procedure, thereby decreasing computer time by 7- to 50-fold, depending on the number of data points and configuration of the logs. Time saving is proportional to the size of the data set. Three examples - one hypothetical and two real-are used to illustrate the modification of the Hawkins and Merriam algorithm.

Chen, H.C.; Fang, J.H.

1986-07-01

355

15. MEREDITH AVENUE, VIEW WITH LOG RAIL AND BARN. PERHAPS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. MEREDITH AVENUE, VIEW WITH LOG RAIL AND BARN. PERHAPS THE LAST REMAINING EXAMPLE OF CCC BUILT "RUSTIC STYLE" GUARD RAIL IN PARK. VIEW NE. - Gettysburg National Military Park Tour Roads, Gettysburg, Adams County, PA

356

Symposium on high-temperature well-logging instrumentation  

SciTech Connect

The symposium contains papers about developments in borehole logging instrumentation that can withstand downhole temperatures in excess of 300/sup 0/C and pressures greater than 103 MPa. Separate abstracts have been prepared for individual papers. (ACR)

Dennis, B.R. (comp.)

1986-06-01

357

Expected Value  

NSDL National Science Digital Library

In this activity, students will use the random integer command on their graphing calculators to simulate rolling a die. They will then use operations on lists to analyze the probability of rolling the first 1 on the 1st roll, 2nd roll, and so on and finally find the expected value. Teacher notes explain in detail how to perform these actions on the graphing calculator.

2008-10-17

358

Use of well logs and core data to assess the sequence stratigraphic distribution of organic-rich rocks  

Microsoft Academic Search

Application of a well log technique for routine profiling of total organic carbon (TOC) in source rocks has revealed that patterns in the vertical distribution of TOC commonly occur. Marine source rocks frequently are composed of one or more units with the highest TOC values near the base. These units coalesce in a seaward direction and form a relatively smooth

S. Creaney; J. Allan; Q. R. Passey

1991-01-01

359

Monte Carlo simulation of the neutron lifetime logging tool  

Microsoft Academic Search

The decay time of neutron pulses in a medium provides a measure of the macroscopic capture cross section of the medium. This principle has long been exploited in oil well logging to differentiate between hydrocarbon-bearing rock formations and water-bearing formations and to detect changes in the water saturation during the production period. The logging tool typically contains a 14-MeV pulsed

H. K. Choi; R. P. Gardner; K. Verghese

1986-01-01

360

Integrating PCLIPS into ULowell's Lincoln Logs: Factory of the future  

NASA Technical Reports Server (NTRS)

We are attempting to show how independent but cooperating expert systems, executing within a parallel production system (PCLIPS), can operate and control a completely automated, fault tolerant prototype of a factory of the future (The Lincoln Logs Factory of the Future). The factory consists of a CAD system for designing the Lincoln Log Houses, two workcells, and a materials handling system. A workcell consists of two robots, part feeders, and a frame mounted vision system.

Mcgee, Brenda J.; Miller, Mark D.; Krolak, Patrick; Barr, Stanley J.

1990-01-01

361

AL-log: Integrating Datalog and Description Logics  

Microsoft Academic Search

We present an integrated system for knowledge representation, calledAL-log, based on description logics and the deductive database language Datalog. AL-log embodies two subsystems, called structural and relational. The former allows for the definition of structural knowledge about classes of interest (concepts) and membership relation between objects and classes. The latter allows for the definition of relational knowledge about objects described

Francesco M. Donini; Maurizio Lenzerini; Daniele Nardi; Andrea Schaerf

1998-01-01

362

Fluid-Rock Characterization and Interactions in NMR Well Logging  

SciTech Connect

The objective of this project was to characterize the fluid properties and fluid-rock interactions which are needed for formation evaluation by NMR well logging. NMR well logging is finding wide use in formation evaluation. The formation parameters commonly estimated were porosity, permeability, and capillary bound water. Special cases include estimation of oil viscosity, residual oil saturation, location of oil/water contact, and interpretation on whether the hydrocarbon is oil or gas.

Hirasaki, George J.; Mohanty, Kishore K.

2003-02-10

363

Local regularity analysis of strata heterogeneities from sonic logs  

Microsoft Academic Search

Borehole logs provide geological information about the rocks crossed by the wells. Several properties of rocks can be interpreted in terms of lithology, type and quantity of the fluid filling the pores and fractures. Here, the logs are assumed to be nonhomogeneous Brownian motions (nhBms) which are generalized fractional Brownian motions (fBms) indexed by depth-dependent Hurst parameters H(z). Three techniques,

S. Gaci; N. Zaourar; M. Hamoudi; M. Holschneider

2010-01-01

364

Logging while drilling keeps horizontal well on small target  

Microsoft Academic Search

This paper reports that the logging-while-drilling (LWD) measurement to two resistivities of different characteristics had led to a new interpretation method for the analysis of horizontal wells. By logging deep and shallow resistivity in real-time, marker beds were identified to help maintain well bore trajectory. The resistivity measurements were split into vertical and horizontal components to provide additional information of

J. Leake; F. Shray

1991-01-01

365

Pseudo-log-polar Fourier transform for image registration  

Microsoft Academic Search

A new registration algorithm based on pseudo-log-polar Fourier transform (PLPFT) for estimating large translations, rotations, and scalings in images is developed. The PLPFT, which is calculated at points distributed at nonlinear increased concentric squares, approximates log-polar Fourier representations of images accurately. In addition, it can be calculated quickly by utilizing the Fourier separability property and the fractional fast Fourier transform.

Hanzhou Liu; Baolong Guo; Zongzhe Feng

2006-01-01

366

Fluid-Rock Characterization and Interactions in NMR Well Logging  

SciTech Connect

The objective of this project was to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity.

Hirasaki, George J.; Mohanty, Kishore K.

2003-02-10

367

WebLogExpert Lite 3.6  

NSDL National Science Digital Library

For those users with websites, this little application will prove to be quite useful. Utilizing this latest version of WebLogExpert Lite, users will be able to review specific statistics about visitors to their site, including activities such as file access, error reports, and the like. The program also can generate reports on such activities that include both tables and charts. This version of WebLogExpert Lite is compatible with all computers running Windows 95 and newer.

2005-01-01

368

A universal generator for discrete log-concave distributions  

Microsoft Academic Search

: We give an algorithm that can be used to sample from any discrete log-concave distribution(e.g. the binomial and hypergeometric distributions). It is based on rejection from a discrete dominatingdistribution that consists of parts of the geometric distribution. The algorithm is uniformly fast for alldiscrete log-concave distributions and not much slower than algorithms designed for a single distribution.AMS Subject Classification:

Wolfgang Hörmann

1994-01-01

369

Methane hydrate pore saturation evaluation from geophysical logging and pressure core analysis, at the first offshore production test site in the eastern Nankai Trough, Japan  

NASA Astrophysics Data System (ADS)

On March 2013, the first offshore production test form methane hydrate (MH) concentrated zone (MHCZ) was conducted by the Research Consortium for Methane Hydrate Resource Development in Japan (MH21) at the AT1 site located in the north-western slope of Daini-Atsumi Knoll in the eastern Nankai Trough, Japan. Before the production test, extensive geophysical logging and pressure coring using Hybrid Pressure Coring System were conducted in 2012 at monitoring well (AT1-MC) and coring well (AT1-C), in order to obtain basic information for the MH reservoir characterization. MH pore saturation (Sh) is one of the important basic parameters not only for reservoir characterization, but also the resource assessment. However, precise evaluation of Sh from geophysical logging is still challenging technical issue. The MHCZ confirmed by the geophysical logging at AT1-MC has a turbidite assemblage (from several tens of centimeters to a few meters) with 60 m of gross thickness; it is composed of lobe/sheet type sequences in the upper part, and relatively thick channel sand sequences in the lower part. In this study, the Sh evaluated from geophysical logging data were compared with those evaluated from pressure core analysis. Resistivity logs and nuclear magnetic resonance (NMR) log were used for the Sh evaluation by geophysical logging. Standard Archie equation was applied for Sh evaluation from resistivity log, while density magnetic resonance (DMR) method was used for Sh evaluation from NMR log. The Sh from pressure core samples were evaluated using the amount of dissociated gas volume, together with core sample bulk volume, measured porosity, net sand intervals, and assumed methane solubility in pore water. In the upper part of the MHCZ, Sh estimated from resistivity log showed distinct difference in value between sand and mud layers, compared to Sh from NMR log. Resistivity log has higher vertical resolution than NMR log, so it is favorable for these kinds of thin bed evaluation. In this part, 50 to 80% of Sh was observed in sandy layer, which showed fairly good agreement with core derived Sh. On the other hand, lower part of the MHCZ, Sh estimated from both resistivity and NMR log showed higher background value and relatively smoother curve than upper part. In this part, 50 to 80% of Sh was observed in sandy layer, which was also showed good agreement with core derived Sh. This study was conducted by the Research Consortium for Methane Hydrate Resource Development in Japan (MH21).

Fujii, T.; Suzuki, K.; Takayama, T.; Konno, Y.; Yoneda, J.; Egawa, K.; Ito, T.; Nagao, J.

2013-12-01

370

Gpr Scanning Methods for Enhanced Data Imaging in Wooden Logs  

NASA Astrophysics Data System (ADS)

A major problem facing wooden saw mills is the presence of hidden or subsurface defects in logs (such as embedded nails and metallic objects, knots and decays) that become visible only after the log is sawed and processed into lumber or veneer. If these defects are detected earlier, that is, before the log is sawn into lumber or sliced into veneer, significant increases in productivity can result by avoiding these defects through optimization of the sawing process. Recently, Ground Penetrating Radar (GPR) has been used to identify subsurface defects in wooden logs. Past study conducted by the authors showed that GPR has the potential to be successfully implemented as a nondestructive method to identify these defects. Therefore, this research is focused on exploring different ways to enhance the GPR data acquisition in order to obtain maximum information from the GPR radargram on the internal condition of wooden logs. Data acquisition involved methods such as canting the logs, designing suitable test set up and using higher frequency antennas. This paper discusses GPR imaging and mapping of the internal defects using data enhancements in a manner suitable for future online implementation.

Pyakurel, Sandeep; Halabe, Udaya B.

2008-02-01

371

Effects of Hydrothermal Alteration on In-situ Physical Properties in an Active Hydrothermal Vent Field - First Results of log Interpretation in ODP Hole 1189B  

NASA Astrophysics Data System (ADS)

For the first time in the history of the Ocean Drilling Program (ODP), Leg 193 drilled into an active hydrothermal vent field associated with felsic magmatism at a convergent plate margin. The main scientific objectives were to study the subsurface volcanic architecture of the Pual ridge, delineate the structural and hydrologic characteristics of the PACMANUS active hydrothermal system, and understand the mineralization and alteration patterns associated with vigorous high temperature fluid flow. Due to low core recovery, downhole logs provide the only continuous records of in-situ physical properties with depth hence the logs are of prime importance for achieving the scientific objectives of the leg. Downhole and core measurements from three holes located in the high temperature Roman Ruins hydrothermal field (Site 1189) show intense hydrothermal alteration of dacites and rhyodacites and evidence of a mineralized stockwork zone. Downhole measurements from Hole 1189B show characteristic cyclic trends with electrical resistivity logs decreasing upwards. The upper parts of these cycles are characterized by increasing values of the photoelectric factor log, an indicator for the composition of the formation and slightly increased density values. The trends correlate with an increase in fracturing/brecciation observed in the electrical images of the FMS (Formation MicroScanner). However, higher values of density and photoelectric factor indicate an enrichment of heavier minerals in the upper parts of the cycles. Spectral gamma ray logs do not correlate with the cyclic variations in the resistivity logs. Uranium, a mobile element often used as indicator for alteration, gives a large contribution to the total gamma ray spectrum. Thus two different assemblages of logs may be used as indicator for alteration/mineralization in Hole 1189B. No correlation exists between the cyclic trends and the variations in the spectral gamma ray logs. This indicates that different alteration processes may be responsible for the cyclic trends and for the variations in the uranium log, respectively.

Bartetzko, A.; Iturrino, G. J.

2001-12-01

372

Perfluorinated compounds in Haihe River and Dagu Drainage Canal in Tianjin, China.  

PubMed

In this study, nine perfluorinated compounds (PFCs) were investigated in water and sediment of Haihe River (HR) and Dagu Drainage Canal (DDC), Tianjin, China. The total PFCs in water samples from DDC (40-174 ngL(-1)) was much greater than those from HR (12-74 ngL(-1)). PFC contamination was severe at lower reaches of HR due to industry activities, while high PFCs were found in the middle of DDC due to the effluents from wastewater treatment plants. Perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were the predominant PFCs in aqueous phase. The total PFCs in sediments from DDC (1.6-7.7 ngg(-1) dry weight) were lower as compared to HR (7.1-16 ngg(-1)), maybe due to the dredging of sediment in DDC conducted recently. PFOS was the major PFC in HR sediments followed by PFOA; while PFHxA was the major PFC in DDC sediments. Organic carbon calibrated sediment-water distribution coefficients (K(OC)) were calculated for HR. The Log K(OC) ranged from 3.3 to 4.4 for C7-C11 perfluorinated carboxylic acids, increasing by 0.1-0.6 log units with each additional CF(2) moiety. The log K(OC) for 8:2 fluorotelomer unsaturated acid was reported for the first time with a mean value of 4.0. The log Koc of PFOS was higher than perfluoronanoic acid by 0.8 log units. PMID:21524781

Li, Fasong; Sun, Hongwen; Hao, Zhineng; He, Na; Zhao, Lijie; Zhang, Tao; Sun, Tiehang

2011-06-01

373

The log N-log S relationship from the BeppoSAX 2-10 keV survey  

NASA Astrophysics Data System (ADS)

The results of a 2 - 10 keV BeppoSAX X-ray survey based on 140 high galactic latitude MECS fields are presented. About 25% of the Cosmic X-ray Background (CXB) is resolved into discrete sources at the sensitivity limit of the survey (S ~ 5×10-14 erg cm-2 s-1). The log N-log S relationship, built with the 177 X-ray sources of the survey, is steep and in good agreement with that derived from ASCA surveys. The results of a CXB fluctuation analysis, which probes the log N-log S down to about 1×10-14 erg cm-2 s-1, are also presented.

Perri, M.; Giommi, P.; Fiore, F.

374

14 CFR 91.1443 - CAMP: Airworthiness release or aircraft maintenance log entry.  

Code of Federal Regulations, 2010 CFR

...Airworthiness release or aircraft maintenance log entry. 91.1443...Airworthiness release or aircraft maintenance log entry. (a) No program...appropriate entry in the aircraft maintenance log. (b) The...

2010-01-01

375

14 CFR 91.1443 - CAMP: Airworthiness release or aircraft maintenance log entry.  

Code of Federal Regulations, 2010 CFR

...Airworthiness release or aircraft maintenance log entry. 91.1443...Airworthiness release or aircraft maintenance log entry. (a) No program...appropriate entry in the aircraft maintenance log. (b) The...

2009-01-01

376

14 CFR 135.443 - Airworthiness release or aircraft maintenance log entry.  

Code of Federal Regulations, 2010 CFR

... Airworthiness release or aircraft maintenance log entry. 135.443... Airworthiness release or aircraft maintenance log entry. (a) No certificate...appropriate entry in the aircraft maintenance log. (b) The...

2010-01-01

377

14 CFR 135.443 - Airworthiness release or aircraft maintenance log entry.  

Code of Federal Regulations, 2010 CFR

... Airworthiness release or aircraft maintenance log entry. 135.443... Airworthiness release or aircraft maintenance log entry. (a) No certificate...appropriate entry in the aircraft maintenance log. (b) The...

2009-01-01

378

Cosmic shear covariance: the log-normal approximation  

NASA Astrophysics Data System (ADS)

Context. Accurate estimates of the errors on the cosmological parameters inferred from cosmic shear surveys require accurate estimates of the covariance of the cosmic shear correlation functions. Aims: We seek approximations to the cosmic shear covariance that are as easy to use as the common approximations based on normal (Gaussian) statistics, but yield more accurate covariance matrices and parameter errors. Methods: We derive expressions for the cosmic shear covariance under the assumption that the underlying convergence field follows log-normal statistics. We also derive a simplified version of this log-normal approximation by only retaining the most important terms beyond normal statistics. We use numerical simulations of weak lensing to study how well the normal, log-normal, and simplified log-normal approximations as well as empirical corrections to the normal approximation proposed in the literature reproduce shear covariances for cosmic shear surveys. We also investigate the resulting confidence regions for cosmological parameters inferred from such surveys. Results: We find that the normal approximation substantially underestimates the cosmic shear covariances and the inferred parameter confidence regions, in particular for surveys with small fields of view and large galaxy densities, but also for very wide surveys. In contrast, the log-normal approximation yields more realistic covariances and confidence regions, but also requires evaluating slightly more complicated expressions. However, the simplified log-normal approximation, although as simple as the normal approximation, yields confidence regions that are almost as accurate as those obtained from the log-normal approximation. The empirical corrections to the normal approximation do not yield more accurate covariances and confidence regions than the (simplified) log-normal approximation. Moreover, they fail to produce positive-semidefinite data covariance matrices in certain cases, rendering them unusable for parameter estimation. Conclusions: The log-normal or simplified log-normal approximation should be used in favour of the normal approximation for parameter estimation and parameter error forecasts. More generally, any approximation to the cosmic shear covariance should ensure a positive-(semi)definite data covariance matrix.

Hilbert, S.; Hartlap, J.; Schneider, P.

2011-12-01

379

New insights into the consequences of post-windthrow salvage logging revealed by functional structure of saproxylic beetles assemblages.  

PubMed

Windstorms, bark beetle outbreaks and fires are important natural disturbances in coniferous forests worldwide. Wind-thrown trees promote biodiversity and restoration within production forests, but also cause large economic losses due to bark beetle infestation and accelerated fungal decomposition. Such damaged trees are often removed by salvage logging, which leads to decreased biodiversity and thus increasingly evokes discussions between economists and ecologists about appropriate strategies. To reveal the reasons behind species loss after salvage logging, we used a functional approach based on four habitat-related ecological traits and focused on saproxylic beetles. We predicted that salvage logging would decrease functional diversity (measured as effect sizes of mean pairwise distances using null models) as well as mean values of beetle body size, wood diameter niche and canopy cover niche, but would increase decay stage niche. As expected, salvage logging caused a decrease in species richness, but led to an increase in functional diversity by altering the species composition from habitat-filtered assemblages toward random assemblages. Even though salvage logging removes tree trunks, the most negative effects were found for small and heliophilous species and for species specialized on wood of small diameter. Our results suggested that salvage logging disrupts the natural assembly process on windthrown trees and that negative ecological impacts are caused more by microclimate alteration of the dead-wood objects than by loss of resource amount. These insights underline the power of functional approaches to detect ecosystem responses to anthropogenic disturbance and form a basis for management decisions in conservation. To mitigate negative effects on saproxylic beetle diversity after windthrows, we recommend preserving single windthrown trees or at least their tops with exposed branches during salvage logging. Such an extension of the green-tree retention approach to windthrown trees will preserve natural succession and associated communities of disturbed spruce forests. PMID:25050914

Thorn, Simon; Bässler, Claus; Gottschalk, Thomas; Hothorn, Torsten; Bussler, Heinz; Raffa, Kenneth; Müller, Jörg

2014-01-01

380

New Insights into the Consequences of Post-Windthrow Salvage Logging Revealed by Functional Structure of Saproxylic Beetles Assemblages  

PubMed Central

Windstorms, bark beetle outbreaks and fires are important natural disturbances in coniferous forests worldwide. Wind-thrown trees promote biodiversity and restoration within production forests, but also cause large economic losses due to bark beetle infestation and accelerated fungal decomposition. Such damaged trees are often removed by salvage logging, which leads to decreased biodiversity and thus increasingly evokes discussions between economists and ecologists about appropriate strategies. To reveal the reasons behind species loss after salvage logging, we used a functional approach based on four habitat-related ecological traits and focused on saproxylic beetles. We predicted that salvage logging would decrease functional diversity (measured as effect sizes of mean pairwise distances using null models) as well as mean values of beetle body size, wood diameter niche and canopy cover niche, but would increase decay stage niche. As expected, salvage logging caused a decrease in species richness, but led to an increase in functional diversity by altering the species composition from habitat-filtered assemblages toward random assemblages. Even though salvage logging removes tree trunks, the most negative effects were found for small and heliophilous species and for species specialized on wood of small diameter. Our results suggested that salvage logging disrupts the natural assembly process on windthrown trees and that negative ecological impacts are caused more by microclimate alteration of the dead-wood objects than by loss of resource amount. These insights underline the power of functional approaches to detect ecosystem responses to anthropogenic disturbance and form a basis for management decisions in conservation. To mitigate negative effects on saproxylic beetle diversity after windthrows, we recommend preserving single windthrown trees or at least their tops with exposed branches during salvage logging. Such an extension of the green-tree retention approach to windthrown trees will preserve natural succession and associated communities of disturbed spruce forests.

Thorn, Simon; Bassler, Claus; Gottschalk, Thomas; Hothorn, Torsten; Bussler, Heinz; Raffa, Kenneth; Muller, Jorg

2014-01-01

381

Carbon emissions from tropical forest degradation caused by logging  

NASA Astrophysics Data System (ADS)

The focus of land-use related efforts in developing countries to reduce carbon emissions has been on slowing deforestation, yet international agreements are to reduce emissions from both deforestation and forest degradation (REDD). The second ‘D’ is poorly understood and accounted for a number of technical and policy reasons. Here we introduce a complete accounting method for estimating emission factors from selective timber harvesting, a substantial form of forest degradation in many tropical developing countries. The method accounts separately for emissions from the extracted log, from incidental damage to the surrounding forest, and from logging infrastructure, and emissions are expressed as units of carbon per cubic meter of timber extracted to allow for simple application to timber harvesting statistics. We applied the method in six tropical countries (Belize, Bolivia, Brazil, Guyana, Indonesia, and Republic of Congo), resulting in total emission factors of 0.99?2.33 Mg C m?3. In all cases, emissions were dominated by damage to surrounding vegetation and the infrastructure rather than the logs themselves, and total emissions represented about 3–15% of the biomass carbon stocks of the associated unlogged forests. We then combined the emission factors with country level logging statistics for nine key timber producing countries represented by our study areas to gain an understanding of the order of magnitude of emissions from degradation compared to those recently reported for deforestation in the same countries. For the nine countries included, emissions from logging were on average equivalent to about 12% of those from deforestation. For those nine countries with relatively low emissions from deforestation, emissions from logging were equivalent to half or more of those from deforestation, whereas for those countries with the highest emissions from deforestation, emissions from logging were equivalent to <10% of those from deforestation. Understanding how to account emissions and the magnitude of each emissions source resulting from tropical timber harvesting practices helps identify where there are opportunities to reduce emissions from the second ‘D’ in REDD.

Pearson, Timothy R. H.; Brown, Sandra; Casarim, Felipe M.

2014-03-01

382

The Effects of Microsite (Logs versus Ground Surface) on the Presence of Forest Floor Biota in a Second-growth Hardwood Forest1  

Microsoft Academic Search

A study conducted in forests at the University of Connecticut investigated the value of logs for biodiversity in second-growth hardwoods. Forest floor microsite (log versus featureless ground surface (soil and leaf litter only)) was significant (P < 0.001) for the frequency of occurrence of representatives of all seven broadly defined life form groups examined. Algae, non-vascular plants, and fungi were

Charlotte Pyle; Michelle M. Brown

2002-01-01

383

Four decades of forest persistence, clearance and logging on borneo.  

PubMed

The native forests of Borneo have been impacted by selective logging, fire, and conversion to plantations at unprecedented scales since industrial-scale extractive industries began in the early 1970s. There is no island-wide documentation of forest clearance or logging since the 1970s. This creates an information gap for conservation planning, especially with regard to selectively logged forests that maintain high conservation potential. Analysing LANDSAT images, we estimate that 75.7% (558,060 km2) of Borneo's area (737,188 km2) was forested around 1973. Based upon a forest cover map for 2010 derived using ALOS-PALSAR and visually reviewing LANDSAT images, we estimate that the 1973 forest area had declined by 168,493 km2 (30.2%) in 2010. The highest losses were recorded in Sabah and Kalimantan with 39.5% and 30.7% of their total forest area in 1973 becoming non-forest in 2010, and the lowest in Brunei and Sarawak (8.4%, and 23.1%). We estimate that the combined area planted in industrial oil palm and timber plantations in 2010 was 75,480 km2, representing 10% of Borneo. We mapped 271,819 km of primary logging roads that were created between 1973 and 2010. The greatest density of logging roads was found in Sarawak, at 0.89 km km-2, and the lowest density in Brunei, at 0.18 km km-2. Analyzing MODIS-based tree cover maps, we estimate that logging operated within 700 m of primary logging roads. Using this distance, we estimate that 266,257 km2 of 1973 forest cover has been logged. With 389,566 km2 (52.8%) of the island remaining forested, of which 209,649 km2 remains intact. There is still hope for biodiversity conservation in Borneo. Protecting logged forests from fire and conversion to plantations is an urgent priority for reducing rates of deforestation in Borneo. PMID:25029192

Gaveau, David L A; Sloan, Sean; Molidena, Elis; Yaen, Husna; Sheil, Doug; Abram, Nicola K; Ancrenaz, Marc; Nasi, Robert; Quinones, Marcela; Wielaard, Niels; Meijaard, Erik

2014-01-01

384

Four Decades of Forest Persistence, Clearance and Logging on Borneo  

PubMed Central

The native forests of Borneo have been impacted by selective logging, fire, and conversion to plantations at unprecedented scales since industrial-scale extractive industries began in the early 1970s. There is no island-wide documentation of forest clearance or logging since the 1970s. This creates an information gap for conservation planning, especially with regard to selectively logged forests that maintain high conservation potential. Analysing LANDSAT images, we estimate that 75.7% (558,060 km2) of Borneo's area (737,188 km2) was forested around 1973. Based upon a forest cover map for 2010 derived using ALOS-PALSAR and visually reviewing LANDSAT images, we estimate that the 1973 forest area had declined by 168,493 km2 (30.2%) in 2010. The highest losses were recorded in Sabah and Kalimantan with 39.5% and 30.7% of their total forest area in 1973 becoming non-forest in 2010, and the lowest in Brunei and Sarawak (8.4%, and 23.1%). We estimate that the combined area planted in industrial oil palm and timber plantations in 2010 was 75,480 km2, representing 10% of Borneo. We mapped 271,819 km of primary logging roads that were created between 1973 and 2010. The greatest density of logging roads was found in Sarawak, at 0.89 km km?2, and the lowest density in Brunei, at 0.18 km km?2. Analyzing MODIS-based tree cover maps, we estimate that logging operated within 700 m of primary logging roads. Using this distance, we estimate that 266,257 km2 of 1973 forest cover has been logged. With 389,566 km2 (52.8%) of the island remaining forested, of which 209,649 km2 remains intact. There is still hope for biodiversity conservation in Borneo. Protecting logged forests from fire and conversion to plantations is an urgent priority for reducing rates of deforestation in Borneo.

Gaveau, David L. A.; Sloan, Sean; Molidena, Elis; Yaen, Husna; Sheil, Doug; Abram, Nicola K.; Ancrenaz, Marc; Nasi, Robert; Quinones, Marcela; Wielaard, Niels; Meijaard, Erik

2014-01-01

385

Logs of Paleoseismic Excavations Across the Central Range Fault, Trinidad  

USGS Publications Warehouse

This publication makes available maps and trench logs associated with studies of the Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. Our studies were conducted in 2001 and 2002. We mapped geomorphic features indicative of active faulting along the right-lateral, Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. We excavated trenches at two sites, the Samlalsingh and Tabaquite sites. At the Samlalsingh site, sediments deposited after the most recent fault movement bury the fault, and the exact location of the fault was unknown until we exposed it in our excavations. At this site, we excavated a total of eleven trenches, six of which exposed the fault. The trenches exposed fluvial sediments deposited over a strath terrace developed on Miocene bedrock units. We cleaned the walls of the excavations, gridded the walls with either 1 m X 1 m or 1 m X 0.5 m nail and string grid, and logged the walls in detail at a scale of 1:20. Additionally, we described the different sedimentary units in the field, incorporating these descriptions into our trench logs. We mapped the locations of the trenches using a tape and compass. Our field logs were scanned, and unit contacts were traced in Adobe Illustrator. The final drafted logs of all the trenches are presented here, along with photographs showing important relations among faults and Holocene sedimentary deposits. Logs of south walls were reversed in Illustrator, so that all logs are drafted with the view direction to the north. We collected samples of various materials exposed in the trench walls, including charcoal samples for radiocarbon dating from both faulted and unfaulted deposits. The locations of all samples collected are shown on the logs. The ages of seventeen of the charcoal samples submitted for radiocarbon analysis at the University of Arizona Accelerator Mass Spectrometry Laboratory in Tucson, Ariz., are given in Table 1. Samples found in Table 1 are shown in red on the trench logs. All radiocarbon ages are calibrated and given with 2 standard deviation age ranges. Our studies suggest that the Central Range Fault is a Holocene fault capable of producing damaging earthquakes in Trinidad

Crosby, Christopher J.; Prentice, Carol S.; Weber, John; Ragona, Daniel

2009-01-01

386

Low-cost log analysis using a graphics-based microcomputer and off-the-shelf software  

SciTech Connect

While the introduction of the microcomputer has been hailed as bringing a desktop revolution, the field of log analysis has not yet gained its full benefit from this revolution. Even so-called entry level log analysis workstations based upon PC-compatibles can demand many thousands of dollars of peripheral hardware - graphic cards, high-resolution monitors, etc. Software lease and maintenance costs may exceed hardware costs in a single year. Recently, however, a new generation of lower cost hardware and software products have become available which place sophisticated color graphics tools in the hands of the computer user. Although not specifically designed for this purpose the tools can be customized to the job with a minimum of effort or programming skill. This two-part series provides an introduction to the use of these new tools using a development of a simple mud log evaluation technique as an example. This subject is a somewhat apt one, i.e. a low-cost application for a low-cost data source. It is also, incidentally, one commonly overlooked by the high-end log analysis workstations and therefore may make the article of value to even those who might otherwise have no interest in low-end systems. Part 1 describes the makeup of a spreadsheet template to compute, from mud and cutting analysis, parameters to predicts reservoir fluid type and productivity which can be used quantitatively in support of a conventional wireline log analysis.

Whittaker, A. (Sanders Whittaker and Associates, Sacramento, CA (United States))

1988-05-01

387

Hyporheic exchange due to channel-spanning logs  

NASA Astrophysics Data System (ADS)

The flow of river water around large woody debris (LWD) creates pressure gradients along the riverbed that drive a large zone of river-groundwater mixing, or hyporheic exchange. Flume experiments and numerical simulations show that river water downwells into the riverbed upstream of a channel-spanning log and upwells downstream. Exchange rates are greatest near the log and decay exponentially with distance upstream and downstream. We developed equations for bed pressure profiles and hyporheic exchange rates in the vicinity of a channel-spanning log that can be used to evaluate the impact of LWD removal or reintroduction on hyporheic mixing. The magnitude of pressure disturbance along the bed (and thus hyporheic exchange) increases with the fraction of channel depth blocked by the log and channel Froude number. Exchange rates are relatively insensitive to relative depth of the log (gap ratio). At natural densities, LWD in lowland streams drives reach-averaged hyporheic exchange rates similar to a ripple-covered bed. However, the length scales and residence times of hyporheic exchange due to LWD are greater. By removing LWD from streams, humans have altered patterns and rates of hyporheic exchange, which influence habitat distribution and quality for invertebrates and fish.

Sawyer, Audrey H.; Bayani Cardenas, M.; Buttles, Jim

2011-08-01

388

Micrometeorology of a Tropical Rainforest Before and After Selective Logging  

NASA Astrophysics Data System (ADS)

We are using long-term eddy covariance to directly measure the effects of selective logging on the energy and trace gas exchange of a tropical forest, as a component of the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). We began measurements in June 2000 from a 65 m tall tower in a primary evergreen stand in the Tapajos National Forest (km 83), Para, Brazil, that was selectively logged during the fall of 2001. In addition to the core flux measurements of carbon dioxide, water vapor, momentum, and heat, sensors have been installed to measure vertical profiles CO2, H2O, wind velocity, and temperature within and above the forest, to aid in understanding the complex micrometeorology that determines the transfer between the forest and the atmosphere. In addition, after the logging a second 65 m tall tower was installed in a large gap created by the logging, and similarly instrumented. Here, we address the micrometeorology of the forest, both before and after the logging.

Miller, S. D.; Goulden, M. L.; Menton, M. C.; Doughty, C.; da Rocha, H.; Freitas, H.; Figueira, M. A.; da Sousa, C. A.

2002-12-01

389

Robust Audio Watermarking Based on Log-Polar Frequency Index  

NASA Astrophysics Data System (ADS)

In this paper, we analyze the audio signal distortions introduced by pitch-scaling, random cropping and DA/AD conversion, and find a robust feature, average Fourier magnitude over the log-polar frequency index(AFM), which can resist these attacks. Theoretical analysis and extensive experiments demonstrate that AFM is an appropriate embedding region for robust audio watermarking. This is the first work on applying log-polar mapping to audio watermark. The usage of log-polar mapping in our work is basically different from the existing works in image watermarking. The log-polar mapping is only applied to the frequency index, not to the transform coefficients, which avoids the reconstruction distortion of inverse log-polar transform and reduces the computation cost. Comparison with the existing methods, the proposed AFM-based watermarking scheme has the outstanding performance on resisting pitch-scaling and random cropping, as well as very approving robustness to DA/AD conversion and TSM (Time-Scale Modification). The watermarked audio achieves high auditory quality. Experimental results show that the scheme is very robust to common audio signal processing and distortions introduced in Stirmark for Audio.

Yang, Rui; Kang, Xiangui; Huang, Jiwu

390

User's manual for geophysical well-logging software programs  

SciTech Connect

Since 1958 the Ground-Water Surveillance Program for the Hanford Site has made geophysical logging measurements in most of the 800 wells and deep boreholes that have been drilled on the Hanford Site. In 1980 the Pacific Northwest Laboratory (PNL), which conducts the Ground-Water Surveillance Program, began forming a computerized data base for storing and retrieving geophysical well log data and developing software for quantitative analysis of the well log data. This report, designed to serve as a user's guide, documents the data base system that handles the well log data. Two programs, DIGLOG1 and LOGIT, are used to manipulate the data. The program DIGLOG1 translates analog paper strip charts into digital format; the program LOGIT is a general utility program that edits, displays, checks, stores, writes, and deletes sets of well log data. These two programs do not provide sophisticated display and analytical capabilities; rather, they provide programs that give the user easy access to powerful standard analytical software.

Petrie, G.M.; Gibson, D.; Blair, S.C.

1983-02-01

391

Evaluate cement with radioactive tracers, directional gamma ray logs  

SciTech Connect

Use of radioactive tracers to evaluate hydraulic fractures has recently been extended through the use of directional gamma ray measurements. The directional gamma ray logging tool determines the azimuthal direction of gamma rays from radioactive isotope-tagged fracture proppants to estimate the fracture direction in well-controlled circumstances. The technology also provides new ways of evaluating primary and squeeze cement jobs by enhancing information from directional gamma ray data with advanced image processing techniques. By tagging the cement with a uniform quantity per unit volume of radioactivity, different levels of gamma ray log response must be attributed to variances in cement quality. Cement evaluation with tracers can help detect: thin cement sheaths; light-weight or low compressive strength cements where the acoustic impedance is near that of water; gas cut cement where the acoustic signal is attenuated; wells with microannulus that cannot be pressured to obtain valid log data; poor casing centralization; and multiple cement stage placement. The paper describes the logging tool, operational procedures, and a log example.

NONE

1996-07-01

392

Experimental correlation between the pKa value of sulfonphthaleins with the nature of the substituents groups.  

PubMed

This work presents the results obtained from a spectrophotometry study performed on some indicators of the sulfonphtaleins like phenol red (PR), thymol blue (TB), bromothymol blue (BTB), xylenol orange (XO) and methylthymol blue (MTB). During the first stage the acidity constants of some of the indicators were determined using the data from spectrophotometry, potentiometry and with the use of the software SQUAD. These were as follows: for the equilibrium 2H+BTB<-->H(2)BTB, log beta(2)=15.069+/-0.046 and for H+BTB<-->HBTB, log beta(1)=8.311+/-0.044. For the XO and the MTB five values were calculated for each, namely, for MTB: log beta(5)=42.035, log beta(4)=38.567+/-0.058, log beta(3)=32.257+/-0.057, log beta(2)=23.785+/-0.057, and log beta(1)=12.974+/-0.045 while for XO: log beta(5)=40.120+/-0.102, log beta(4)=35.158+/-0.062, log beta(3)=29.102+/-0.053, log beta(2)=21.237+/-0.044, and log beta(1)=11.682+/-0.044. During the second stage, a study was conducted on the effect of the substituents present in the indicators to determine the effect of different functional groups on the pK(a) value corresponding to the last indicator's dissociation. PMID:17716940

Balderas-Hernández, Patricia; Ramírez-Silva, María Teresa; Romero-Romo, Mario; Palomar-Pardavé, Manuel; Roa-Morales, Gabriela; Barrera-Diaz, Carlos; Rojas-Hernández, Alberto

2008-04-01

393

A large sample of calibration stars for Gaia: log g from Kepler and CoRoT fields  

NASA Astrophysics Data System (ADS)

Asteroseismic data can be used to determine stellar surface gravities with precisions of <0.05 dex by using the global seismic quantities and ?max along with standard atmospheric data such as Teff and metallicity. Surface gravity is also one of the four stellar properties to be derived by automatic analyses for one billion stars from Gaia data (workpackage GSP_PHOT). In this paper, we explore seismic data from main-sequence F, G, K stars (solar-like stars) observed by the Kepler spacecraft as a potential calibration source for the methods that Gaia will use for object characterization (log g). We calculate log g for some bright nearby stars for which radii and masses are known (e.g. from interferometry or binaries), and using their global seismic quantities in a grid-based method, we determine an asteroseismic log g to within 0.01 dex of the direct calculation, thus validating the accuracy of our method. We also find that errors in adopted atmospheric parameters (mainly [Fe/H]) can, however, cause systematic errors of the order of 0.02 dex. We then apply our method to a list of 40 stars to deliver precise values of surface gravity, i.e. uncertainties of the order of 0.02 dex, and we find agreement with recent literature values. Finally, we explore the typical precision that we expect in a sample of more than 400 Kepler stars which have their global seismic quantities measured. We find a mean uncertainty (precision) of the order of better than 0.02 dex in log g over the full explored range 3.8 < log g < 4.6, with the mean value varying only with stellar magnitude (0.01-0.02 dex). We study sources of systematic errors in log g and find possible biases of the order of 0.04 dex, independent of log g and magnitude, which accounts for errors in the Teff and [Fe/H] measurements, as well as from using a different grid-based method. We conclude that Kepler stars provide a wealth of reliable information that can help to calibrate methods that Gaia will use, in particular, for source characterization with GSP_PHOT, where excellent precision (small uncertainties) and accuracy in log g is obtained from seismic data.

Creevey, O. L.; Thévenin, F.; Basu, S.; Chaplin, W. J.; Bigot, L.; Elsworth, Y.; Huber, D.; Monteiro, M. J. P. F. G.; Serenelli, A.

2013-05-01

394

Evaluation of Diagnostic Value in Using a Panel of Multiple Tumor-Associated Antigens for Immunodiagnosis of Cancer  

PubMed Central

To determine whether a panel of multiple tumor-associated antigens (TAAs) would enhance antibody detection, the diagnostic value of autoantibodies to a panel of multiple TAAs in cancer has been evaluated. The TAAs used in this study was composed of eight TAAs including Imp1, p62, Koc, p53, C-myc, Cyclin B1, Survivin, and p16 full-length recombinant proteins. Enzyme-linked immunosorbent assay and immunoblotting were used to detect antibodies in 304 cancer sera and also 58 sera from normal individuals. The antibody frequency to any individual TAA in cancer was variable but rarely exceeded 20%. With the successive addition of TAAs to a final combination of total of eight antigens, there was a stepwise increase of positive antibody reactions reaching a sensitivity of 63.5% and a specificity of 86.2% in the combined cancer group. In different types of cancer, the ranges of positive and negative likelihood ratio were 4.07–4.76 and 0.39–0.51, respectively, and the ranges of positive and negative predictive values were 74.2–88.7% and 58.8–75.8%, respectively. Agreement rate and Kappa value were 67.1% and 0.51, respectively. These results further support our previous hypothesis that detection of anti-TAAs autoantibodies for diagnosis of certain type of cancer can be enhanced by using a miniarray of several TAAs.

Wang, Peng; Song, Chunhua; Xie, Weihong; Ye, Hua; Wang, Kaijuan; Dai, Liping; Zhang, Yi; Zhang, Jianying

2014-01-01

395

Limit Distribution Theory for Maximum Likelihood Estimation of a Log-Concave Density  

PubMed Central

We find limiting distributions of the nonparametric maximum likelihood estimator (MLE) of a log-concave density, i.e. a density of the form f0 = exp ?0 where ?0 is a concave function on ?. Existence, form, characterizations and uniform rates of convergence of the MLE are given by Rufibach (2006) and Dümbgen and Rufibach (2007). The characterization of the log–concave MLE in terms of distribution functions is the same (up to sign) as the characterization of the least squares estimator of a convex density on [0, ?) as studied by Groeneboom, Jongbloed and Wellner (2001b). We use this connection to show that the limiting distributions of the MLE and its derivative are, under comparable smoothness assumptions, the same (up to sign) as in the convex density estimation problem. In particular, changing the smoothness assumptions of Groeneboom, Jongbloed and Wellner (2001b) slightly by allowing some higher derivatives to vanish at the point of interest, we find that the pointwise limiting distributions depend on the second and third derivatives at 0 of Hk, the “lower invelope” of an integrated Brownian motion process minus a drift term depending on the number of vanishing derivatives of ?0 = log f0 at the point of interest. We also establish the limiting distribution of the resulting estimator of the mode M(f0) and establish a new local asymptotic minimax lower bound which shows the optimality of our mode estimator in terms of both rate of convergence and dependence of constants on population values.

Balabdaoui, Fadoua; Rufibach, Kaspar; Wellner, Jon A.

2009-01-01

396

Model for water factor measurements with fission-neutron logging tools. National Uranium Resource Evaluation  

SciTech Connect

During 1977 and 1978, a Fission Neutron Water Factor Model was designed and constructed by Bendix Field Engineering Corporation (BFEC) for the United States Department of Energy (DOE) at the Grand Junction facility. This model features seven water-filled boreholes with different diameters. All of these boreholes penetrate, in order from the top of the model, a 5-foot-thick (1.52 m), uniform, concrete upper ''barren zone''; a 6-foot-thick (1.83 m), uniform, uranium-enriched, concrete ''ore zone''; and a 4-foot-thick (1.22 m), uniform, concrete lower ''barren zone''. The response of a fission neutron logging tool in a water-filled borehole is affected by variations in the borehole diameter. This diameter-dependent effect can be deduced from logs run in several different boreholes of the Fission Neutron Water Factor Model. This report describes the construction of the Fission Neutron Water Factor Model and also presents values for model parameters which are of interest in fission-neutron logging.

Koizumi, C. J.

1983-05-01

397

Predictive role of minimal residual disease and log clearance in acute myeloid leukemia: a comparison between multiparameter flow cytometry and Wilm's tumor 1 levels.  

PubMed

In acute myeloid leukemia (AML), the detection of minimal residual disease (MRD) as well as the degree of log clearance similarly identifies patients with poor prognosis. No comparison was provided between the two approaches in order to identify the best one to monitor follow-up patients. In this study, MRD and clearance were assessed by both multiparameter flow cytometry (MFC) and WT1 expression at different time points on 45 AML patients achieving complete remission. Our results by WT1 expression showed that log clearance lower than 1.96 after induction predicted the recurrence better than MRD higher than 77.0 copies WT1/10(4) ABL. Conversely, on MFC, MRD higher than 0.2 % after consolidation was more predictive than log clearance below 2.64. At univariate and multivariate analysis, positive MRD values and log clearance below the optimal cutoffs were associated with a shorter disease-free survival (DFS). At the univariate analysis, positive MRD values were also associated with overall survival (OS). Therefore, post-induction log clearance by WT1 and post-consolidation MRD by MFC represented the most informative approaches to identify the relapse. At the optimal timing of assessment, positive MRD and log-clearance values lower than calculated thresholds similarly predicted an adverse prognosis in AML. PMID:24554303

Rossi, Giovanni; Minervini, Maria Marta; Melillo, Lorella; di Nardo, Francesco; de Waure, Chiara; Scalzulli, Potito Rosario; Perla, Gianni; Valente, Daniela; Sinisi, Nicola; Cascavilla, Nicola

2014-07-01

398

Biosorption of phenanthrene by pure algae and field-collected planktons and their fractions.  

PubMed

The biosorption isotherms for phenanthrene (Phen) by cultured algae, field-collected plankton, and market algae samples (OSs) and their fractions (lipid-LP, lipid free carbon-LF, alkaline nonhydrolyzable carbon-ANHC, and acid nonhydrolyzable carbon-NHC) were established. All the biosorption isotherms are well fitted by the Freundlich model. The biosorption isotherms for the ANHC and NHC fractions are nonlinear and for the other fractions are linear. It was found that the NHC fractions are chemically and structurally different from other fractions by using elemental analysis and Fourier transformed infrared spectroscopy (FTIR), consisting mainly of aliphatic polymethylene carbon. The average KOC values for Phen at Ce=0.005Sw are 10706±2768mLg(-1) and 95843±55817mLg(-1) for the bulk market algal samples and their NHC isolates, respectively. As the NHC fraction for Porphyra contains higher polymethylene carbon than that for Seaweed or Spirulina, it exhibits higher biosorption capacity. Moreover, the logKOC values are significantly higher for the field-collected samples than for the market algae and cultured algae samples. The multivariate correlation shows that the logKOC values are positively related to the LP contents, and negatively to the C/N ratios for the original algal samples. Furthermore, the logKOC values are negatively related to the polarity indices (O/C and O+N/C) for the original samples and their fractions excluding LP fractions. These observations help to understand the role of polarity, LP and NHC fractions, and aliphatic structures in the biosorption of Phen, which requires more attention in the examination of sorption processes in the natural environment. PMID:23714149

Zhang, Dainan; Ran, Chenyang; Yang, Yu; Ran, Yong

2013-09-01

399

Wireline well logging an underutilized technique in reservoir evaluation  

SciTech Connect

Wireline well logs have three general uses in geothermal exploration and reservoir evaluation: reservoir parameter analysis, lithologic column determination, and reservoir size resolution. Reservoir flow testing data are acquired to understand the flow rate, life, and production potential of the geothermal reservoir. These data are a coarse subsurface measurement of the geothermal prospect. Wireline logs acquired from wells in a geothermal prospect are used to define in detail, or estimate the reservoir parameters of temperature, thickness, lateral size, amount of fracture and intergranular pore space, and the quantity and quality of fluid that might be produced. Laboratory measurements can be made on core samples and drill cuttings samples to define the intrinsic behavior of the materials and fluid that compose the geotheraml reservoir. Wireline log measurements are needed to correlate and link the reservoir testing and core analysis, reduce the amount of time needed for flow testing, and predict the production life (amount of heat and fluid available) in a geothermal field.

Mathews, M.

1981-01-01

400

Borehole Logging from Sample Collection to Borehole Geophysics  

NSDL National Science Digital Library

In January of 2003, CSUF drilled and completed a deep multiport-monitoring well on the north side of campus. This was done in order to gain a better understanding of the local subsurface geology and groundwater conditions in and around CSUF. Samples were collected from the drill hole (boring) every 5-feet. The total depth of the well is 870 feet below ground surface (grade). Borehole geophysical data (E-log) information was collected from the boring prior to the installation of the well pipe. As you describe the soil samples, compare and contrast your findings to those of the geophysical signature (gamma-ray log) found in the accompanying "E-log" for the boring.

Laton, Richard

401

A novel quantum representation for log-polar images  

NASA Astrophysics Data System (ADS)

The power of quantum mechanics has been extensively exploited to meet the high computational requirement of classical image processing. However, existing quantum image models can only represent the images sampled in Cartesian coordinates. In this paper, quantum log-polar image (QUALPI), a novel quantum image representation is proposed for the storage and processing of images sampled in log-polar coordinates. In QUALPI, all the pixels of a QUALPI are stored in a normalized superposition and can be operated on simultaneously. A QUALPI can be constructed from a classical image via a preparation whose complexity is approximately linear in the image size. Some common geometric transformations, such as symmetry transformation, rotation, etc., can be performed conveniently with QUALPI. Based on these geometric transformations, a fast rotation-invariant quantum image registration algorithm is designed for log-polar images. Performance comparison with classical brute-force image registration method reveals that our quantum algorithm can achieve a quartic speedup.

Zhang, Yi; Lu, Kai; Gao, Yinghui; Xu, Kai

2013-09-01

402

Acoustic cement bond logging diagnostics for geothermal applications  

SciTech Connect

For the successful and safe operation of a geothermal well, casing and cement conditions must be accurately determined. Cement bond logs are needed to detect channels or water pockets in the cement between the pipe and the formation and to determine the condition of the cement bond to the pipe and to the formation. Instrumentation for making such measurements is limited by the temperature capabilities (< 175/sup 0/C) of existing logging equipment which was developed for the oil and gas industry. This paper reviews an acoustic system of the type that is needed for geothermal cementing inspection, identifies the principle deficiencies in its high temperature use, and describes Sandia's R and D project for developing high temperature acoustic cement bond logging diagnostics.

Chang, H.T.

1981-01-01

403

Electromagnetic-induction logging to monitor changing chloride concentrations  

USGS Publications Warehouse

Water from the San Joaquin Delta, having chloride concentrations up to 3590 mg/L, has intruded fresh water aquifers underlying Stockton, California. Changes in chloride concentrations at depth within these aquifers were evaluated using sequential electromagnetic (EM) induction logs collected during 2004 through 2007 at seven multiple-well sites as deep as 268 m. Sequential EM logging is useful for identifying changes in groundwater quality through polyvinyl chloride-cased wells in intervals not screened by wells. These unscreened intervals represent more than 90% of the aquifer at the sites studied. Sequential EM logging suggested degrading groundwater quality in numerous thin intervals, typically between 1 and 7 m in thickness, especially in the northern part of the study area. Some of these intervals were unscreened by wells, and would not have been identified by traditional groundwater sample collection. Sequential logging also identified intervals with improving water quality—possibly due to groundwater management practices that have limited pumping and promoted artificial recharge. EM resistivity was correlated with chloride concentrations in sampled wells and in water from core material. Natural gamma log data were used to account for the effect of aquifer lithology on EM resistivity. Results of this study show that a sequential EM logging is useful for identifying and monitoring the movement of high-chloride water, having lower salinities and chloride concentrations than sea water, in aquifer intervals not screened by wells, and that increases in chloride in water from wells in the area are consistent with high-chloride water originating from the San Joaquin Delta rather than from the underlying saline aquifer.

Metzger, Loren F.; Izbicki, John A.

2013-01-01

404

Formation factor logging by electrical methods. Comparison of formation factor logs obtained in situ and in the laboratory.  

PubMed

In this paper, a new in situ method for obtaining the formation factor, which is essential for the matrix diffusion, is described and tested in intrusive igneous rock. The method is based on electrical resistivity measurements in rock where the pore water and rock resistivities are essential parameters. The method is based on electromigration instead of diffusion as in traditional diffusion experiments. In previous works, quantitative formation factors of rock have been obtained by electrical methods in the laboratory. Here, a similar approach is used in situ. An in situ logging campaign was performed by SKB during 2000 in the 1700-m-deep borehole KLX02 in Laxemar, Sweden. The rock resistivity was measured with the slimhole Dual Laterolog from Antares. The groundwater resistivity was measured with the Difference Flow Meter from Posiva. A formation factor log was obtained with the maximum vertical resolution of 10 cm. In order to validate the log, 100 rock samples were taken from the bore core, and a formation factor log was obtained by using electrical methods in the laboratory. Both direct current (DC) and alternating current (AC) were used. The measurements on the core confirmed that the in situ log was quantitative, but with a possible systematic error. The in situ formation factors were on average about 1/3 to 1/5 of the laboratory formation factors, depending on depth. PMID:12598098

Löfgren, Martin; Neretnieks, Ivars

2003-03-01

405

NADIR: Monitoring, Error Handling, and Logging with Tango  

NASA Astrophysics Data System (ADS)

The ingest and transport of a large amount of astronomical data, in geographically distributed archives, imply some challenging issues, like remote control and configuration, monitoring and logging anomalous conditions, fault tolerance and error handling. Based on this considerations and on our experience in data management, we started development of a New Archiving Distributed InfrastructuRe (NADIR), using Tango (Team 2013; S. Gara 2012), a well known distributed control system (DCSs) within scientific environments, taking advantage of its key features, like reliability, scalability, logging and alarm system, consolidated pattern and template, to solve this complexity. In this paper we discuss about design choices and technical aspects around this project.

De Marco, M.; Knapic, C.; Smareglia, R.

2014-05-01

406

Tracking algorithms using log-polar mapped image coordinates  

NASA Technical Reports Server (NTRS)

The use of log-polar image sampling coordinates rather than conventional Cartesian coordinates offers a number of advantages for visual tracking and docking of space vehicles. Pixel count is reduced without decreasing the field of view, with commensurate reduction in peripheral resolution. Smaller memory requirements and reduced processing loads are the benefits in working environments where bulk and energy are at a premium. Rotational and zoom symmetries of log-polar coordinates accommodate range and orientation extremes without computational penalties. Separation of radial and rotational coordinates reduces the complexity of several target centering algorithms, described below.

Weiman, Carl F. R.; Juday, Richard D.

1990-01-01

407

Quality control log with CUSUM and clinically useful limits criteria.  

PubMed

We describe a quality control (QC) log including its advantages over the more commonly used Levey-Jennings and Shewart graphic charts. It represents a practical system of analytic quality control for quantitative assays in clinical chemistry. It utilizes cumulative sum (CUSUM) techniques and comparison of means to monitor acute and chronic analytic drift, respectively. Clinically useful limits (CUL) criteria for QC decisions are used. An algorithm to facilitate the description of, training for, and use of, the QC log system is provided. PMID:3838642

Schoen, I; Custer, E; Graham, G; Bandi, Z; Surovik, M H

1985-04-01

408

Towards a Stochastic Cellular Automata Model of Log Wood Combustion  

NASA Astrophysics Data System (ADS)

Describing the combustion of log wood and others solid fuels with complex geometry, considerable water content and often heterogenous struture is a nontrivial task. Stochastic Cellular Automata models offer a promising approach for modelling such processes. Combustion models of this type exhibit several similarities to the well-known forest fire models, but there are also significant differences between those two types of models. These differences call for a detailed analysis and the development of supplementary modeling approaches. In this article we define a qualitative two-dimensional model of burning log wood, discuss the most important differences to classical forest fire models and present some preliminary results.

Lichtenegger, Klaus; Schappacher, Wilhelm; Hebenstreit, Babette; Schmidl, Christoph; Höftberger, Ernst

2014-03-01

409

Pulsed neutron gamma-ray logging in archaeological site survey  

NASA Astrophysics Data System (ADS)

An archaeological survey method based on neutron gamma-ray logging is described. The method relies on the measurement of capture gamma radiation induced by neutron irradiation from a pulsed generator. This technique provides elemental information on the irradiated zone by spectroscopic analysis of the gamma-ray data. This approach has been studied with Geant4 Monte Carlo simulations. In particular, irradiation volume for a deuterium-deuterium and deuterium-tritium (D-T) neutron generator and sampling volume for the D-T source were estimated. In addition, a neutron log response, which illustrates the capability of the neutron tool to localize artifacts lying beneath the surface, is shown.

Miceli, A.; Festa, G.; Gorini, G.; Senesi, R.; Andreani, C.

2013-12-01

410

CRYPTOSPORIDIUM LOG-INACTIVATION WITH OZONE USING EFFLUENT CT 10, GEOMETRIC MEAN CT 10 EXTENDED INTEGRATED CT 10 AND EXTENDED-CSTR CALCULATIONS  

EPA Science Inventory

The draft Long Term 2 Enhanced Surface Water Treatment Rule ("LT2ESWTR") contains Cryptosporidium log-inactivation CT tables. Depending on the water temperature, the Cryptosporidium CT values that are listed are 15 to 25 times greater than CT values fo...

411

Considerations Related to Drilling Methods in Planning and Performing Borehole-Geophysical Logging for Ground-Water Studies.  

National Technical Information Service (NTIS)

The report reviews various aspects of drilling, sampling and borehole geophysical logging that affect the effectiveness of well-log interpretation and the precision of well-log calibration using recovered samples, cuttings, or driller's logs. Because well...

R. E. Hodges, W. E. Teasdale

1991-01-01

412

Suppression of Log-Weibull Distributed Sea-Ice Clutter Using a Modified LOG/CFAR System  

NASA Astrophysics Data System (ADS)

We observed sea-ice clutter using a millimeter wave radar with a frequency 34.860 GHz, a beamwidth 0.25°, and a plusewidth 30 ns which is located at the city of Mombetsu in Hokkaido. To determine the sea-ice clutter amplitude, we introduce the Akaike Information Criterion (AIC). It is discovered that the sea-ice clutter amplitudes obey the log-Weibull distribution with the shape parameters of 2.36 to 2.93 in terms of the temporal and small scale range fluctuations with which a constant false alarm rate (CFAR) is concerned. We propose a new log-Weibull/CFAR system uses a modified cell-averaging LOG/CFAR system. It is found that sea-ice clutter is suppressed with the improvement of more than 40 dB.

Sayama, Shuji; Ishii, Seishiro; Sekine, Matsuo

413

Use of multiattribute transforms to predict log properties from seismic data  

Microsoft Academic Search

We describe a new method for predicting well-log properties from seismic data. The analysis data consist of a series of target logs from wells which tie a 3-D seis- mic volume. The target logs theoretically may be of any type; however, the greatest success to date has been in predicting porosity logs. From the 3-D seismic volume a series of

Daniel P. Hampson; James S. Schuelke; John A. Quirein

2001-01-01

414

Can a Log of Infusion Device Events Be Used to Understand Infusion Accidents?  

Microsoft Academic Search

Objective: This study sought to determine whether infusion device event logs could support accident investigation. Methods: An incident reporting database was searched for infor- mation about log file use in investigations. Log file data from devices in clinical use were downloaded and electronically searched for characteristics (signatures) matching specific function queries. Dif- ferent programming sequences were simulated, and device logs

Yuval Bitan; Mark E. Nunnally

2007-01-01

415

Interpretation of ES-Logs. Final Report, October 1991-April 1995.  

National Technical Information Service (NTIS)

There are roughly 500,000 electric logs (ES-logs) for wells in the U.S. Many of these are in cased wells, precluding the possibility of further resistivity logging. Thus, these old ES-logs are an invaluable resource for the possible reentry of older field...

W. W. Whitman

1995-01-01

416

Interpretation of ES-Logs. Annual Report, October 1991-September 1992.  

National Technical Information Service (NTIS)

There are roughly 500,000 electric logs (ES-logs) for wells in the U.S. Many of these are in cased wells, precluding the possibility of further resistivity logging. Thus, these old ES-logs are an invaluable resource for the possible reentry of older field...

W. W. Whitman

1992-01-01

417

Interpretation of ES-Logs. Annual Report, October 1992-September 1993.  

National Technical Information Service (NTIS)

There are roughly 500,000 electric logs (ES-logs) for wells in the U.S. Many of these are in cased wells, precluding the possibility of further resistivity logging. Thus, these old ES-logs are an invaluable resoure for the possible reentry of older fields...

W. W. Whitman

1993-01-01

418

Optimistic Message Logging for Independent Checkpointing in Message-Passing Systems  

Microsoft Academic Search

Message-passing systems with communication protocoltransparent to the applications typically requiremessage logging to ensure consistency between checkpoints.This paper describes a periodic independentcheckpointing scheme with optimistic logging to reduceperformance degradation during normal executionwhile keeping the recovery cost acceptable. Bothtime and space overhead for message logging can bereduced by detecting messages that need not be logged.A checkpoint space reclamation...

Yi-min Wang; W. Kent Fuchs

1992-01-01

419

Logging in the Congo Basin: A multi-country characterization of timber companies  

Microsoft Academic Search

Industrial logging has been the subject of strong debate, epitomised by the contentious positions around logging in the Congo Basin. Logging companies are often considered as homogeneous and rather static agents, which leads to sweeping generalisations about their performance and the subsequent technical and policy recommendations. This study covers 31 logging concessions in the five ITTO member countries of the

Manuel Ruiz Pérez; Driss Ezzine de Blas; Robert Nasi; Jeffrey A. Sayer; Marieke Sassen; Claudine Angoué; Norbert Gami; Ousseynou Ndoye; Grégoire Ngono; Jean-Claude Nguinguiri; Donatien Nzala; Benjamin Toirambe; Yves Yalibanda

2005-01-01

420

Small-Sample Equating with Log-Linear Smoothing.  

ERIC Educational Resources Information Center

This study investigated the extent to which log-linear smoothing could improve the accuracy of common-item equating by the chained equipercentile method in small samples of examinees. Examinee response data from a 100-item test (the Advanced Placement Examination in United States History) were used to create two overlapping forms of 58 items each,…

Livingston, Samuel A.

421

Future Internet Security Services Enabled by Sharing of Anonymized Logs  

Microsoft Academic Search

As security monitoring grows more complicated, there is an increased demand for outsourcing these tasks for to Managed Security Service Providers (MSSPs). However, the core problem of sharing private data creates a barrier to the widespread adoption of this business model. In this position paper we propose an anonymization solution that promotes sharing logs with MSSPs while simultaneously protecting privacy.

Jianqing Zhang; Nikita Borisov; William Yurcik; Adam J. Slagell; Matthew Smith

422

Logging utilization: Utah, 1993. Forest Service resource bulletin  

SciTech Connect

The report includes the results of a study of timber harvesting operations in Utah to derive factors used to estimate logging residue, growing-stock and sawtimber removals, diameter class distributions of harvests, and board-foot and cubic-foot conversions.

McLain, W.H.

1997-05-01

423

1. OVERVIEW OF AREA B OF SITE, SHOWING LOG BUILDING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. OVERVIEW OF AREA B OF SITE, SHOWING LOG BUILDING AND BUNKHOUSE AT LEFT (Features 9 and 10), RUIN AND SHED IN CENTER (Features 11 and 12), AND HOUSE RUIN AT RIGHT (Feature 13), LOOKING EAST-NORTHEAST - Gold Dust Mine, Mill & Camp Complex, Wards Gulch, Salmon, Lemhi County, ID

424

Analysis of a Very Large AltaVista Query Log  

Microsoft Academic Search

In this paper we present an analysis of a 280 GB AltaVista Search Engine query log consisting of approximately 1 billion entries for search requests over a period of six weeks. This represents approximately 285 million user sessions, each an attempt to fill a single information need. We present an analysis of individual queries, query duplication, and query sessions. Furthermore

Craig Silverstein

1998-01-01

425

Dual-cone double-helical downhole logging device  

DOEpatents

A broadband downhole logging device includes a double-helix coil wrapped over a dielectric support and surrounded by a dielectric shield. The device may also include a second coil longitudinally aligned with a first coil and enclosed within the same shield for measuring magnetic permeability of downhole formations and six additional coils for accurately determining downhole parameters.

Yu, Jiunn S. (Albuquerque, NM)

1984-01-01

426

Improved simulation for interpreting temperature logs in water injection wells  

Microsoft Academic Search

An improved simulation for temperature logs (TL) in water injection wells, is described. Improvements, based on the reduction of assumptions used by previous investigators, are demonstrated by comparison of field data and simulator results showing excellent agreement of TL profiles over the entire well depth. The utility of short period hot water injection just preceding shut-in, as an injection profile

J. Fagley; H. S. Fogler; C. B. Davenport; R. S. Millhone

1981-01-01

427

Micrometeorology of a Tropical Rainforest Before and After Selective Logging  

Microsoft Academic Search

We are using long-term eddy covariance to directly measure the effects of selective logging on the energy and trace gas exchange of a tropical forest, as a component of the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). We began measurements in June 2000 from a 65 m tall tower in a primary evergreen stand in the Tapajos National Forest (km

S. D. Miller; M. L. Goulden; M. C. Menton; C. Doughty; H. da Rocha; H. Freitas; M. A. Figueira; C. A. da Sousa

2002-01-01

428

Logging, a bigger threat to the rainforest than we knew  

NSDL National Science Digital Library

The amount of land in the Amazon rainforest that's being damaged by human activities is twice as large as we had previously thought, suggests a new study. That's because researchers didn't have a good idea of how much logging was occurring there, until now.

American Association for the Advancement of Science (AAAS;)

2005-10-20

429

Comparison between moving and stationary transmitter systems in induction logging  

NASA Astrophysics Data System (ADS)

In a general treatment of the theory of induction logging, an exact integral representation has been obtained for the mutual impedance between a vertical dipole transmitter and a coaxial dipole receiver in a three layered earth. Based on this representation, a computer model has been devised using the traditional Slingram system of induction logging and the comparatively new Turam system, ignoring borehole effects. The model results indicate that due to its much larger response, the Turam system is in general preferable to the Slingram in mineral and groundwater investigations where formation conductivity much less than 1 S/m is generally encountered. However, if the surrounding media are conductive (more than 0.1 S/m), the Turam system suffers from large amplitude attenuation and phase rotation of the primary field caused by the conductive surrounding, and is less useful than the Slingram system which does not so suffer, unless the target bed is shallow. Because it is a more complex function of system parameters than the corresponding Slingram log, a Turam log can be conveniently interpreted only by the modern inverse method using a fast algorithm for the forward solution and a high speed digital computer.

Poddar, M.; Caleb Dhanasekaran, P.; Prabhakar Rao, K.

1985-09-01

430

A Log-Periodic Cavity-Backed Slot Array.  

National Technical Information Service (NTIS)

The communication describes the element investigation, design, and testing of a backfire log-periodic cavity-backed slot array operating from 2.8 to 5.9 GHz in a frequency-independent fashion. The gain of the antenna is approximately 10 dB, and the VSWR i...

A. G. Roederer

1968-01-01

431

Using Transaction Log Analysis To Improve OPAC Retrieval Results.  

ERIC Educational Resources Information Center

An OPAC transaction log analysis at the University of Illinois at Chicago revealed that users had trouble with basic search techniques. After the introductory screens were simplified, a second analysis showed improved search results, indicating that monitoring OPACs can lead to improved information retrieval when changes are made in response to…

Blecic, Deborah D.; Bangalore, Nirmala S.; Dorsch, Josephine L.; Henderson, Cynthia L.; Koenig, Melissa H.; Weller, Ann C.

1998-01-01

432

Small-Sample Equating with Log-Linear Smoothing.  

ERIC Educational Resources Information Center

The extent to which log-linear smoothing could improve the accuracy of common-item equating by the chained equipercentile method in small samples of examinees was investigated with responses from a 100-item test and 93,283 examinees. Smoothing reduced the sample size required for a given degree of accuracy. (SLD)

Livingston, Samuel A.

1993-01-01

433

On the Computation of the Log-Polar Transform  

Microsoft Academic Search

This research note reports an algorithm for computing the log-polartransform of a digital image using optimal parameters for use in an activevision system. In the past, only cursory attention has been givento the selection of transform parameters. This is likely because the exactvalues of the parameters are of little significance in the transformwhen the image and the transform are defined

Richard Alan Peters II; Magued Bishay

1996-01-01

434

Note on log-periodic description of 2008 financial crash  

NASA Astrophysics Data System (ADS)

We analyse the financial crash in 2008 for different financial markets from the point of view of log-periodic function model. In particular, we consider Dow Jones index, DAX index and Hang Seng index. We shortly discuss the possible relation of the theory of critical phenomena in physics to financial markets.

Bolonek-Lason, Katarzyna; Kosinski, Piotr

2011-11-01

435

16. LOG AND PLANK BRIDGE ON ACCESS ROAD NEAR BRIDGE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. LOG AND PLANK BRIDGE ON ACCESS ROAD NEAR BRIDGE SITE; SAME STRUCTURE AS SHOWN IN PHOTO #12. ZION NP NEGATIVE NO. 967 ZIO. - Zion-Mount Carmel Highway, Virgin River Bridge, Spanning North Fork of Virgin River on Zion-Mount Carmel Highway, Springdale, Washington County, UT

436

7. VIEW OF ROLLER FOR EARTH COMPACTING, WITH LOG TONGUE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. VIEW OF ROLLER FOR EARTH COMPACTING, WITH LOG TONGUE FOR STOCK, BUILT ON-SITE AND USED TO CONSTRUCT DAM, LOOKING EAST - High Mountain Dams in Upalco Unit, Five Point Lake Dam, Ashley National Forest, 12 miles Northwest of Swift Creek Campground, Mountain Home, Duchesne County, UT

437

Store well-logging data with ObjectStore ODBMS  

NASA Astrophysics Data System (ADS)

How to store well-logging data in a database is a problem encountered by developers of exploration software. A method to store these data with an ODBMS is presented; C+ + is the programming language and ObjectStore the database system. This method is applied to the development of GRIstation—a joint project between GRI China and STS USA.

Li, Haifei

1995-12-01

438

THE DESIGN OF UWB ANTENNA USING LOG-PERIODIC TECHNIQUE  

Microsoft Academic Search

This paper described the design, simulation and fabrication of the Ultra Wideband (UWB) antennas using seventeen elements log-periodic (LP) technique. The antennas have been modeled using microstrip lines and S parameter data from individual single element. The data is extracted from the momentum simulation and combined with the microstrip transmission line. The properties of antennas such as bandwidth return loss

M. K. A. Rahim; M. R. Ahmad; A. Asrokin; M. Z. A. A. Aziz

439

Dipole dispersion crossover and sonic logs in a limestone reservoir  

Microsoft Academic Search

Analyses of sonic logs in a horizontal well provide new information about mechanical properties of rocks, made possible by recent developments in their understanding of acoustic wave propagation in prestressed formations. Most sections of this horizontal well exhibit azimuthal shear isotropy, indicating isotropic stresses in the plane perpendicular to the well trajectory, leading to stable wellbore conditions. However, two sections

Bikash K. Sinha; Michael R. Kane; Bernard Frignet

2000-01-01

440

Paneling and Flooring from Low-Grade Hardwood Logs.  

National Technical Information Service (NTIS)

From small, low-grade hardwood logs, the Forest Products Laboratory has developed an experimental wall paneling that is equally suitable for flooring. Short cutoffs of the panel material can also be utilized as parquet block flooring. One of the keys is p...

B. G. Heebink K. C. Compton

1966-01-01

441

Fluid-Rock Characterization and Interactions in NMR Well Logging  

SciTech Connect

The objective of this report is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity. Oil based drilling fluids can have an adverse effect on NMR well logging if it alters the wettability of the formation. The effect of various surfactants on wettability and surface relaxivity are evaluated for silica sand. The relation between the relaxation time and diffusivity distinguishes the response of brine, oil, and gas in a NMR well log. A new NMR pulse sequence in the presence of a field gradient and a new inversion technique enables the T{sub 2} and diffusivity distributions to be displayed as a two-dimensional map. The objectives of pore morphology and rock characterization are to identify vug connectivity by using X-ray CT scan, and to improve NMR permeability correlation. Improved estimation of permeability from NMR response is possible by using estimated tortuosity as a parameter to interpolate between two existing permeability models.

George J. Hirasaki; Kishore K. Mohanty

2005-09-05

442

Logging and Recovery in Adaptive Software Distributed Shared Memory Systems  

Microsoft Academic Search

Software distributed shared memory (DSM) improves the programmability of message-passing machines and work- station clusters by providing a shared memory abstract (i.e., a coherent global address space) to programmers. As in any distributed system, however, the probability of software DSM failures increases as the system size grows. This pa- per presents a new, efficient logging protocol for adaptive software DSM

Angkul Kongmunvattana; Nian-feng Tzeng

1999-01-01

443

CONFIDENCE INTERVALS FOR THE LOG-NORMAL MEAN  

Microsoft Academic Search

SUMMARY In this paper we conduct a simulation study to evaluate coverage error, interval width and relative bias of four main methods for the construction of confidence intervals of log-normal means: the naive method; Cox's method; a conservative method; and a parametric bootstrap method. The simulation study finds that the naive method is inappropriate, that Cox's method has the smallest

SUJUAN GAO

1997-01-01

444

A transaction log analysis of a digital library  

Microsoft Academic Search

As experimental digital library testbeds gain wider acceptance and develop significant user bases, it becomes important to investigate the ways in which users interact with the systems in practice. Transaction logs are one source of usage information, and the information on user behaviour can be culled from them both automatically (through calculation of summary statistics) and manually (by examining query

Steve Jones; Sally Jo Cunningham; Rodger J. Mcnab; Stefan J. Boddie

2000-01-01

445

Sample Sizes for Small-Log Recovery Factors.  

National Technical Information Service (NTIS)

This investigation addresses itself to two questions: (a) How many logs of a given diameter class need be sampled in a sawmill for specified precision in the sample mean lumber recovery factor (LRF). (b) How many sawmills should be sampled for specified p...

J. Dobie W. G. Warren

1974-01-01

446

Analysis of a very large web search engine query log  

Microsoft Academic Search

In this paper we present an analysis of an AltaVista Search Engine query log consisting of approximately 1 billion entries for search requests over a period of six weeks. This represents almost 285 million user sessions, each an attempt to fill a single information need. We present an analysis of individual queries, query duplication, and query sessions. We also present

Craig Silverstein; Hannes Marais; Monika Henzinger; Michael Moricz

1999-01-01

447

A LOG-Periodic Cavity-Backed Slot Antenna.  

National Technical Information Service (NTIS)

It has been shown that it is possible by considering the dual of the successful log-periodic dipole arrary to produce a broad-band antenna in the form of a cavity-slot radiator. It has thus been demonstrated that principles for successful operation in the...

V. A. Mikenas

1964-01-01

448

4. VIEW OF CRIBBED LOG STRUCTURE OVER TUNNEL AIR HOLE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. VIEW OF CRIBBED LOG STRUCTURE OVER TUNNEL AIR HOLE AND OUTLET VALVE, LOOKING NORTH - High Mountain Dams in Upalco Unit, Farmers Lake Tunnel, Ashley National Forest, 5.7 miles North of Swift Creek Campground, Mountain Home, Duchesne County, UT

449

DARK ENERGY FROM THE LOG-TRANSFORMED CONVERGENCE FIELD  

SciTech Connect

A logarithmic transform of the convergence field improves 'the information content', i.e., the overall precision associated with the measurement of the amplitude of the convergence power spectrum, by improving the covariance matrix properties. The translation of this improvement in the information content to that in cosmological parameters, such as those associated with dark energy, requires knowing the sensitivity of the log-transformed field to those cosmological parameters. In this paper, we use N-body simulations with ray tracing to generate convergence fields at multiple source redshifts as a function of cosmology. The gain in information associated with the log-transformed field does lead to tighter constraints on dark energy parameters, but only if shape noise is neglected. The presence of shape noise quickly diminishes the advantage of the log-mapping, more quickly than we would expect based on the information content. With or without shape noise, using a larger pixel size allows for a more efficient log-transformation.

Seo, Hee-Jong [Berkeley Center for Cosmological Physics, LBL and Department of Physics, University of California, Berkeley, CA 94720 (United States); Sato, Masanori [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Takada, Masahiro [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, Chiba 277-8582 (Japan); Dodelson, Scott, E-mail: hee-jongseo@lbl.gov [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)

2012-03-20

450

20. DETAIL OF DOOR TO FIRST LOG PEN OF NORTH ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. DETAIL OF DOOR TO FIRST LOG PEN OF NORTH WALL (north wall of north entry (right side), at the southeast corner of first of four pens which form the north wall of the barn). VIEW LOOKING WEST. Date: July 10, 1937; negative #10636 - Witt Shields Barn, Townsend, Blount County, TN

451

Development, Implementation and Assessment of a Progressive Reading Log System  

NSDL National Science Digital Library

Students in upper-level Engineering classes such as Fluid Mechanics often find themselves faced with over 60 pages of reading a week in addition to assigned problems and exam preparation. Since the reading of the textbook is often infrequently assessed, this aspect of course learning is often postponed or omitted. In addition, with this amount of reading, many students quickly find themselves so far behind in the reading that they can no longer catch up. A reading log system where content responsibility is progressively shifted from the instructors questions to student identification and reflection has been developed and implemented in junior-level Fluid Mechanics and Thermodynamics courses to address several of the issues associated with student use of the textbook. The goal of the reading log is to improve student use of resource material and to provide opportunities for students to develop skills in reading scientific material. Reflective questioning, guided identification of key concepts, probing questions and cyclic problems are some of the tools that are used to stimulate student use of the textbook. In addition, the progressive content of the reading logs is designed to transition the student from rote learning to self-reflection and synthesis of understanding. To evaluate the effectiveness of the resource, student surveys and responses to reading log questions have beenused to guide its development.

Benson, Daniel

2011-05-03

452

Circularly polarized log-periodic dipole antenna for EMI measurements  

Microsoft Academic Search

Two types of broad-band antennas are widely used for electromagnetic interference (EMI) measurements in the frequency range from 30 to 1000 MHz. Log-periodic dipole antennas (LPDA) are mainly used for the range above 300 MHz and biconical antennas for the range less than 300 MHz. These two antennas have linear polarization. However, EMI measurements can sometimes be more conveniently made

Ryoji Wakabayashi; Kazuo Shimada; Haruo Kawakami; Gentei Sato

1999-01-01

453

The design of nine element quasi microstrip log periodic antenna  

Microsoft Academic Search

This paper described the design, simulation and fabrication of the inset feed log periodic antenna with nine elements. The antennas have been modeled using microstrip lines and S parameter data from an individual single element. The data is extracted from the simulation and combined with the microstrip transmission line. The properties of antennas such as bandwidth, gain, cross-polar isolation and

M. K. A. Rahim; P. Gardner

2004-01-01

454

Grammar-based task analysis of web logs  

Microsoft Academic Search

The daily use of Internet-based services is involved with hundreds of different tasks being performed by multiple users. A single task is typically involved with a sequence of Web URLs invocation. We study the problem of pattern detection in Web logs to identify tasks performed by users, and analyze task trends over time using a grammar-based framework. Our results are

Savitha Srinivasan; Arnon Amir; Prasad M. Deshpande; Vladimir Zbarsky

2004-01-01

455

THE INFLUENCE OF THE BOREHOLE ENVIRONMENT UPON COMPRESSIONAL SONIC LOGS  

Microsoft Academic Search

The observed compressional sonic recorded with conventional sonic devices is affected by formation and\\/or filtrate water salinity, dissolved gas. borehole and formation temperature, pore pressure, low saturation biogenic free gas, and the presence of hydrocarbons. The magnitude of this effect is not well appreciated by users of borehole sonic logs. These factors can have a significant effect upon measured interval

Mark Alberty

1994-01-01

456

Application Scenarios for Nonstandard Log-Linear Models  

ERIC Educational Resources Information Center

In this article, the authors have 2 aims. First, hierarchical, nonhierarchical, and nonstandard log-linear models are defined. Second, application scenarios are presented for nonhierarchical and nonstandard models, with illustrations of where these scenarios can occur. Parameters can be interpreted in regard to their formal meaning and in regard…

Mair, Patrick; von Eye, Alexander

2007-01-01

457

Observing the Night Sky --- Observing Logs and Guided Inquiry  

NASA Astrophysics Data System (ADS)

The University of Arizona has initiated a General Education program for all incoming freshmen. All non-science majors must take two introductory Natural Science courses. At the same time the decision was made to eliminate formal labs, but to require instructors to incorporate lab experiences into their Natural Science courses (which typically have 100 to 200 students). For this reason, we have made an Observing Log a major component of our Natural Science class. To make the Log more effective, and to use it as an assessment tool in class, we have incorporated an inquiry-based component. We felt that many observing experiences were ``cookbook'' in nature: make an observation and write down what you saw. Ridgeway and Padilla (The Science Teacher, November 1998) developed what they called Guided Thinking. They proposed ``using three-level thinking guides to promote inquiry in the classroom.'' We have incorporated their procedures into our Observing Log Term Project by having students make a series of guided observations that they can link together with what they have learned in the regular classroom setting. We also take advantage of the Teaching Teams program (peer classroom tutors) so that students can make their observations and discuss them in a small-group setting. A summary of the Observing Log Term Project and examples of student work will be presented.

Lebofsky, L. A.; Lebofsky, N. R.

2000-10-01

458

Treatment of Log Yard Runoff in an Aerobic Trickling Filter  

Microsoft Academic Search

Contaminated stormwater runoff from log yards is generated when precipitation comes into contact with wood, woody debris and equipment at outdoor wood sorting, processing and storage facilities. Nine runoff samples collected at a sawmill had biochemical oxygen demand (BOD), chemical oxygen demand (COD), tannins and lignin (T+L), and total suspended solids (TSS) levels ranging from 25 to 745 mg\\/L, 125

Christine Woodhouse; Sheldon J. B. Duff

2004-01-01

459

Flume experiments of log incipient motion in rivers  

NASA Astrophysics Data System (ADS)

In natural rivers the transport phenomena of floating debris involve a large number of problems that are relevant to both environmental and technical aspects. A large part of the research developed has been motivated by linkages between fish habitat and geomorphological processes and forms influenced by large woody debris, but drifts reduce also the capacity of bridge openings, contribute to scour around piers and abutements, and increase lateral forces on bridges. Large woody debris (LWD) is defined as a log having at least 10 cm mid-point diameter, being 2 m in length while the term CWD (coarse woody debris) usually refers to smaller pieces. Key pieces are individual logs with rootwads that are less likely to move than other wood pieces during a bankfull flow. They play a relevant role in snags amassing because key pieces constitute the first step of the woody accumulation process. To identify hydraulic thresholds for movement and transport of key pieces for different log geometries we developed a series of experiments in a flume model 0.30 m wide and 5.0 m long with about 10% slope transversal to the main flow direction. The log, with and without rootwads, is assumed fallen on the sloping bank and the hydraulic threshold is analyzed as a function of log geometry and hydrodynamic action. The key pieces are simulated by wood cylinder ended with an octagon (to take into account the rootwad) of different lengths and thicknesses. Besides the acquisition of water level and discharge as usual, the video recording of the experiments permits the identification of the log position at the threshold of motion into the flume. A conceptual model, based on the 3-D stationary equilibrium of gravity, buoyancy, friction and hydrodynamic forces acting on a rigid body, was developed to allow the interpretation of scale flume model experiments. From the preliminary analysis of laboratory experiments it seems that the condition of incipient motion is mainly controlled by the ratio between the rootwad size and the log length.

Salandin, P.; Camporese, M.

2007-12-01

460

A complete X-ray sample of the high latitude sky from HEAO-1 A-2: log N lo S and luminosity functions  

NASA Technical Reports Server (NTRS)

An experiment was performed in which a complete X-ray survey of the 8.2 steradians of the sky at galactic latitudes where the absolute value of b is 20 deg down to a limiting sensitivity of 3.1 x ten to the minus 11th power ergs/sq cm sec in the 2-10 keV band. Of the 85 detected sources 17 were identified with galactic objects, 61 were identified with extragalactic objects, and 7 remain unidentified. The log N - log S relation for the non-galactic objects is well fit by the Euclidean relationship. The X-ray spectra of these objects were used to construct log N - log S in physical units. The complete sample of identified sources was used to construct X-ray luminosity functions, using the absolute maximum likelihood method, for clusters galaxies and active galactic nuclei.

Piccinotti, G.; Mushotzky, R. F.; Boldt, E. A.; Holt, S. S.; Marshall, F. E.; Serlemitsos, P. J.; Shafer, R. A.

1981-01-01

461

The design and implementation of a log-structured file system  

Microsoft Academic Search

This paper presents a new technique for disk storage management called a log-structured file system. A log-structured file system writes all modifications to disk sequentially in a log-like structure, thereby speeding up both file writing and crash recovery. The log is the only structure on disk; it contains indexing information so that files can be read back from the log

Mendel Rosenblum; John K. Ousterhout

1992-01-01

462

Choosing the averaging interval when calculating primary reflection coefficients from well logs  

SciTech Connect

Most seismic data is processed using a sample interval of 4 ms two-way time (twt). The study of the statistical properties of primary reflection coefficients showed that the power spectrum of primaries can change noticeably when the logs are averaged over blocks of 0.5, 1 and 2 ms twt (block-averaging). What is a suitable block-averaging interval for producing broadband synthetics, and in particular how should the power spectrum of primaries be constructed when it is to be used to correct 4 ms sampled deconvolved seismic data for the effects of coloured primary reflectivity. In this paper the authors show that for a typical sonic log, a block-averaging interval of 1 ms twt should satisfy some important requirements. Firstly, it is demonstrated that if the reflection coefficients in an interval are not too large the effect of all the reflection impulses can be represented by another much sparser set at intervals of ..delta..t twt. The coefficient amplitudes are given by the differences in the logarithmic acoustic impedances, thus justifying block-averaging. However, a condition for this to hold up to the aliasing (Nyquist) frequency is that ..delta..t takes a maximum value of about 1 ms twt. Secondly, an event on a log should be represented in the seismic data. For this the acoustic impedance contrast must have sufficient lateral extent or continuity. By making some tentative suggestions on the relation between continuity and bed-thickness, a bed-thickness requirement of 0.15 m or more is obtained. Combining this requirement with the maximum number of beds allowable in an interval in order that multiple reflections do not contribute significantly to the reflections in the interval, again suggests a value of about 1 ms for the block-averaging interval.

Walden, A.T.; Hosken, J.W.J.

1988-11-01

463

a New Application of a Fiber Optic Gyro in Magnetic Borehole Logging  

NASA Astrophysics Data System (ADS)

A borehole magnetometer from the Institute of Geophysics, University of Goettingen, Germany, was employed in Hole 1203A on Detroit Seamount. The tool consists of three fluxgate sensors which log the two horizontal (X, Y) and the vertical (Z) component of the magnetic induction with depth. For the first time, a fiber optic angular rate sensor was employed in a borehole tool to measure the rotation history during a log run in combination with fluxgate sensors. This rate sensor is an unconventional gyro since it does not have a spinning wheel. This is why it is free from the effects of gravity-induced errors, and with no moving parts, this sensor is insensitive to shock and vibration. It detects and measures angular rates by measuring the frequency difference between two contra-rotating light beams. A magnetic log was run in Hole 1203A on Detroit seamount from the rig floor to the total depth at 925 mbsf. The rotation history of the tool is determined by the accumulation of the rate during a log run. In Hole 1203A the tool rotated almost 60 times about its vertical body axis between the rig floor and the bottom of the hole. On its run back to the floor the tool followed nearly the same rotation history as on the downward run. Aligning to the ship axis and double checking the orientation with the initial orientation enabled changes in the heading of the ship and the Earth's rotation, which also affects the angular rate to be taken into account. It revealed that the difference between the initial and final orientation was less than 5 degrees. During the log run many strongly magnetized layers were encountered in the volcanic basement, which correlate well with sequences of massive and pillowed basalts recovered in the drill core. The anomalous field variations of the vertical component always points towards negative values, which indicates a general magnetic polarisation direction parallel to the present geomagnetic field. The natural remanent magnetization and inclination of the formation is obtained by linear inversion of the horizontal and vertical components of the anomalous magnetic field. 16 lava flow units were chosen to estimate the inclination averaged across each unit. The mean inclination is about 44 deg, corresponding to a latitude of 26 degrees, which is clearly different from the present-day latitude of the Hawaii hotspot (19 degrees).

Stoll, J. B.; Leven, M.; Steveling, E.

2002-12-01

464

Integrated NMR Core and Log Investigations With Respect to ODP LEG 204  

NASA Astrophysics Data System (ADS)

NMR techniques are widely used in the oil industry and are one of the most suitable methods to evaluate in-situ formation porosity and permeability. Recently, efforts are directed towards adapting NMR methods also to the Ocean Drilling Program (ODP) and the upcoming Integrated Ocean Drilling Program (IODP). We apply a newly developed light-weight, mobile NMR core scanner as a non-destructive instrument to determine routinely rock porosity and to estimate the pore size distribution. The NMR core scanner is used for transverse relaxation measurements on water-saturated core sections using a CPMG sequence with a short echo time. A regularized Laplace-transform analysis yields the distribution of transverse relaxation times T2. In homogeneous magnetic fields, T2 is proportional to the pore diameter of rocks. Hence, the T2 signal maps the pore-size distribution of the studied rock samples. For fully saturated samples the integral of the distribution curve and the CPMG echo amplitude extrapolated to zero echo time are proportional to porosity. Preliminary results show that the NMR core scanner is a suitable tool to determine rock porosity and to estimate pore size distribution of limestones and sandstones. Presently our investigations focus on Leg 204, where NMR Logging-While-Drilling (LWD) was performed for the first time in ODP. Leg 204 was drilled into Hydrate Ridge on the Cascadia accretionary margin, offshore Oregon. All drilling and logging operations were highly successful, providing excellent core, wireline, and LWD data from adjacent boreholes. Cores recovered during Leg 204 consist mainly of clay and claystone. As the NMR core scanner operates at frequencies higher than that of the well-logging sensor it has a shorter dead time. This advantage makes the NMR core scanner sensitive to signals with T2 values down to 0.1 ms as compared to 3 ms in NMR logging. Hence, we can study even rocks with small pores, such as the mudcores recovered during Leg 204. We present a comparison of data from core scanning and NMR logging. Future integration of conventional wireline data and electrical borehole wall images (RAB/FMS) will provide a detailed characterization of the sediments in terms of lithology, petrophysics and, fluid flow properties.

Arnold, J.; Pechnig, R.; Clauser, C.; Anferova, S.; Blümich, B.

2005-12-01

465

Reservoir microfacies and their logging response of gas hydrate in the Qilian Mountain permafrost in Northwest China  

NASA Astrophysics Data System (ADS)

The Qilian Mountain permafrost is located in the north margin of the Qinghai-Tibet Plateau in northwest China. The permafrost area is about 10×104 Km2, and dominated by mountain permafrost. The mean annual ground temperature is 1.5 to 2.4 centigrade and the thickness of permafrost is generally 50 to 139 m. The gas hydrate was sampled successfully in the 133-396m interval from holes DK-1, DK-2 and DK-3 and tested by microRaman spectroscopy in the hydrate laboratory of the Qingdao Institute of Marine Geology during June to September in 2009. The exploratory drilling indicated that gas hydrate and its abnormal occurrence are mainly developed 130-400 m beneath permafrost. The strata belong to the Jiangcang Formation of middle Jurassic. Based on lithology, sedimentary structure and sequence and other facies markers, reservoir microfacies of gas hydrate are identified as underwater distributary channel and interdistributary bay in delta front of delta and deep lake mudstone facies in lacustrine. The underwater distributary channel in delta front of delta is dominated by fine sandstone. It has little mudstone. The grain size generally becomes finer, and scour-filling structure, parallel bedding, cross bedding and wavy bedding develop successively from bottom to top in one phase of channel. In vertical multi-period distributary channels superimpose, forming thick sandstone, and sometimes a thin mudstone develop between two channels. The interdistributaty bay is characterized by mudstone with little siltstone and fine sandstone. The lithology column shows mudstone interbedded with thin sandstone. Horizon bedding and lenticular bedding are the main structure. The gas hydrate usually presents visible white (smoky gray when mixing with mud) ice-like lamina in fissures or invisible micro disseminated occurrence in pores of sandstone. Honeycomb pores formed by the decomposition of gas hydrate are usually found in sandstone. The deep lake is dominated by thick dark grey mudstone and oil shale with horizon bedding. Some plant clasts can be found in mudstone. The gas hydrate generally presents white ice-like lamina in fissures of mudstone and oil shale. Underwater distributary channel and interdistributary bay have big variation amplitude on the logging curves. The extend of gamma (Gr) logging curve is 30 to 140 API, the acoustic (AC) logging curve is 300 to 400?s/m and the apparent resistivity (Rt) logging curve is 20-60?×m. The sandstone layer has characteristics of low Gr and AC value and high Rt value, whereas the mudstone layer has characteristics of high Gr and AC value and low Rt value. In shape, the underwater distributary channel shows tooth-like funnel-shaped pattern on Gr logging curve and bell-shaped pattern on Rt curve, whereas the underwater distributary bay presents tooth-like box-shaped pattern on both Gr and Rt curves. Deep lake mudstone has a relatively small variation amplitude on the logging curves. The extend of Gr logging curve is 45-80 API, the AC logging curve is 280-325?s/m, and the Rt logging curve is 25-50?×m. In the Gr and Rt logging curves, it generally presents box-shaped or tooth-like box-shaped pattern.

Liu, H.; Lu, Z.; Zhang, Y.; Sun, Z.

2012-12-01

466

The log N-log S curve for 3CR radio galaxies and the problem of identifying faint radio galaxies  

NASA Technical Reports Server (NTRS)

The log N-log S slope of optically identified galaxies in the 3CR catalog is analyzed for galaxies with flux levels greater than 10 Jy and located at galactic latitudes greater than 7 deg. For the 86 galaxies with known redshifts, the slope is found to be about 1.16; for all 119 galaxies, the slope is found to be about 1.50. If the 113 unidentified sources are included, the slope steepens to about 1.81. It is shown that this steepness is caused by the unidentified sources. Assuming that the slope is due to evolution at redshifts of 1 to 3 and that the unidentified sources are bright ellipticals, the mean redshifts and apparent brightnesses of these galaxies are calculated. The results indicate that it is impossible to observe the unidentified sources with existing ground-based telescopes, implying that it is presently impossible to establish directly that evolution is responsible for the steep log N-log S curve of the 3CR galaxies.

Burbidge, G. R.; Narlikar, J. V.