bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Injection Monitoring Techniques For Minagish Oolite Reservoir In West Kuwait
Authors: Das Om Prakash , Aslam Muhammad , Bahuguna Rakesh , Al-Enezi Khalaf , Hussain Al-Shatti Mohammed , Tahani Yousef Al-Rashidi
Published: December 2009

Water flooding is the most successful and widely used process for effective pressure maintenance and enhancing the oil recovery because water is widely available and inexpensive relative to other fluids, easy to inject, and highly efficient in displacing oil. For water floods, through continuous surveillance plan, reservoir monitoring and water front tracking results in improving sweep efficiency and enhancing the overall oil recovery.

Minagish Oolite (MO) reservoir is a mature reservoir having long production history along with water injection from several years as a primary means of pressure maintenance. In MO reservoir, two types of water injection methods are implemented i.e. power water injection (PWI) and Dump Flood Injection (DFI).

For water injection monitoring and water front tracking a semi analytical model is developed for MO reservoir based on radius of injected cool water front superimposed over seismic and geological cross-sections to monitor the water front position at real time inside MO reservoir. The radius of expanding cool injected water front is obtained by saturation logs (TDT) and layer wise cumulative water injection at various points across the formation. The layer wise cumulative water injection is calculated from production logs on injectors as well as nearby offset producers.

The water injection monitoring techniques based on focused surveillance program and semi analytical model has been developed for both DFI (Dump Flood Injectors) and PWI (Power Water Injectors) which is used for improving water flood conformance in MO reservoir.

In case of MO reservoir the semi analytical model along with Hall plot and its derivative function at sand face is found to be an alternative to pressure transient analysis,

pressure fall off tests, injection tests and tracer survey analysis used for water front tracking and water injection conformance. The methodology has proven to be the best tool for monitoring the performance of both PWI and DFI wells in Minagish Oolite reservoir.

Based on the water conformance modeling, the correct decisions regarding the various workover related to water injectors as well as producers were taken to control the injection water movement through faults, channels and high permeability layers inside MO reservoir. This in turn resulted in uniform pressure maintenance, reduction in water cut as well as minimizing the risks of by passing the oil behind the injectors.
Hydrogen Induced Cracking (HIC) Assessment in a Gas Processing Plant
Authors: Said Yousef , Abufour Mohammed A.
Published: December 2009

A Saudi Aramco Gas processing Plant commissioned in 1980 to process wet sour gas streams and produce dry sweet sales gas in addition Natural Gas Liquid (NGL). A detailed assessment study was conducted in this plant pertaining to Hydrogen Induced Cracking (HIC). Corrosion loops were established for the sour environment and revealed that HIC is one of the potential damage mechanisms that could affect the sour gas system. HIC is susceptible to be presented in the sour gas system because of the following criteria:•Hydrogen sulfide (H2S) concentration is ranging from 2–41 mol% which equivalent to 20,000–410,000 ppm of H2S.•Piping and vessels were fabricated by non HIC resistant material.•Present of element sulfur in the streams.•Temperature ranging from 120–280 ???F.•Present of free water in the fluid stream.

INTRODUCTION

Hydrogen atoms are generated by corrosion reaction of H2S and Fe in present of free water. The hydrogen atoms, which have the smallest atomic elements are diffuses into steel and traps in mill laminations or voids. Then, every two atoms combine together to form hydrogen molecular. As per the below the reaction in present of water

The trapped molecular hydrogen in the mill laminations or voids will have high internal pressure which will cause hydrogen blistering or cracking. For illustration, see Figure #1 to illustrate the reaction. And Figure #2 to illustrate the diffusion mechanism of hydrogen in the mill laminations or voids. Figure #3 an actual internal hydrogen blistering. Figure #4 an actual external hydrogen blistering.

The mechanism of HIC is similar to that for hydrogen blistering. If two or more adjacent blisters are close enough so that the crack tips are overlap, a series of stepwise cracks (SWC) will be developed. In this stage, a potential dangerous situation which could lead to rapture and gas leak. As shown in Figure # 5 and Figure #6.
Robotics for Horizontal Image Acquisition in Ultra Slim Wells in Saudi Arabia
Authors: Al-Awami Nassar Adnan , Khalsa Kanwal Bahadur Singh , Pinero Nelson Oscar , Al-Baggal Zaki Abdullah , Mumen Adib , Zainaddin Ibrahim Ahmed
Published: December 2009

The cost savings that are possible by sidetracking existing wellbores make the drilling and completion of ultra slim lateral wells very desirable. Obtaining image logs from horizontal wells, less than 6" diameter, has always been a challenge, because the size of conventional borehole imaging tools that currently exist on the market are simply too large. In addition, conventional deployment methods limit efficient rig time utilization and ultimately lead to higher cost. New conveyance and logging technology from Welltec® (the Well Tractor®) and Weatherford (The Compact Micro Imager - CMI) allows operators to obtain excellent image logs in slim wells as small as 3" in diameter. Image logs are required to properly understand fracture details and to help in future drilling and completion decisions.

This paper describes the logging operational experience of the CMI and the world's first slim hole imaging logs in Saudi Arabia deployed by the wireline tractor 218XR (XR: Extended Reach) in an open hole horizontal section.

Introduction

Workover operations are a major part of any oil field operator. Well maintenance and repair is performed during workover operations. Repairs include replacement of completion string, casing patch, perforation shut-off, etc. In addition, re-entry and horizontal drilling and open hole completion technology has enabled the operators to increase production and recovery rates from declining fields and short interval pay zones.

Abqaiq Field

Initially the field was developed by drilling vertical producers. The remaining oil column is short and can go as low as 3 to 4 ft in some areas. With field in production, water cut has increased with time. One strategy to save cost of drilling new wells is to re-visit old vertical wells and complete them as horizontal producers.

The re-entry horizontal drilling methodology for Abqaiq field has evolved over time. Due to the original 7" cased hole production completion, a 6??? window is cut for sidetrack in the 7" casing and curve section is drilled to above target formation and a 4½" or 5" liner is run to isolate the high-pressure water formation just above pay formation.

After casing off the curve section, drilling proceeds with 3??? or 4??? horizontal hole in the target formation until reaching total depth (TD).
Leadership Influence in Safety Change Process
Authors: Malallah Sami Hussain
Published: December 2009

Behavioral-based Safety is a well-established method for changing workers behavior and incident rates. However, a variety of approaches exist, some of which are more effective than others. To determine the most effective design of a behavioral safety process, a review of Behavioral-based Safety field studies was conducted from a safety practitioner's viewpoint focused entirely on the degree of behavioral change and incident reduction resulting from different types of implementation. The objectives of this paper are to demonstrate how individual feedback coming from the observer at worksite to the worker could make the worker change his at-risk behavior to safe behavior. The paper will investigate management communications and group feedback affect to increase the observers' contribution to the behavior-based safety process. The paper will display the importance and direct effect of the leader role in driving safety processes and programs. Remarkable improvement in workers behavior was seen when an active leader was assigned to the Behavior-based Safety process and a dedicated committee was helping him.

Observers willingly participate in the behavior-based safety process. They perform site observations to improve workplace safety. The leader's feedback on their individual performance and the progress of the behavior-based safety process helped them believing in the process. Which in fact, increased the number of observations, and consequently the safe behavior record improved.
Real Time Simulation of the Dispersion of Accidental Emission Release of Hazardous Substance on Industrial Site using 3D Modelling.
Authors: Libre Jean-marie , Tripathi Amita , Le Guellec Mallo , Mailliard Thibault , Guerin Stephanie , Souprayen Claude , Castellari Aldo
Published: December 2009

The knowledge in real time of the concentration fields resulting from the accidental release of hazardous substance would be extremely valuable information as support for emergency actions and impact evaluation on the industrial site itself and its vicinity. For that purpose, a modelling platform is being developed and applied to simulate in real time the atmospheric dispersion of hazardous substance at the scale of the industrial site and also on its surroundings. The industrial site of Lacq (France) has been chosen as a pilot and the key hazardous substance considered in this study is hydrogen sulphide (H2S). A 3D CFD (Computational Fluid Dynamic) model (Fluidyn-Panepr) has been chosen, to simulate the 3D wind field pattern on the industrial site, taking into account the details of the installations. This approach enables a simulation as close as possible of the turbulence and flow around the buildings which could not be done with a standard Gaussian approach. For that purpose a detailed numerical model of Lacq installation was built based on a thorough review of the existing installations and evaluation of their size and porosity. Wind fields were calculated for a set of predefined boundary conditions based on the climatology of the site. Investigations were carried out to ensure that site Information Systems could deliver in real time the information available from the H2S sensors and on site meteorological station. The real time approach is made possible by the use of complete wind field pre-calculated database automatically selected in case of accidental release by comparison with real time wind direction and speed measurements from the meteorological station located on the industrial site. The location and intensity of the source term is determined using a probabilistic approach (Bayesian inference) making use of both real time measurements and pre-calculated concentration responses from unitary emissions (puffs) on sensors. This approach was validated successfully using a limited number of sensors and sources but with the complex structure and flow patterns expected on the site. The activation of the simulation platform is triggered by the detection of above threshold concentrations at the sensors. The estimated source term is then used in forward dispersion mode to simulate the dispersion in (fast) Lagrangian puff mode. The modelling platform will be validated through measurement campaigns with neutral species in 2010.
An Integrated Analysis for the Re-assessment of Hydrocarbon Potential of a Low Prospect Area: A Case Study on Jurassic Marrat Reservoir of Burgan Structure in South East Kuwait.
Authors: Dey Arun Kanti , Singh Sunil Kumar , Banik Nikhil , Ammar Heyam Muhammed , Khan Badruzzaman
Published: December 2009

The hydrocarbon potential of Jurassic sediment of Burgan area in southeast Kuwait was re-evaluated after the discovery of hydrocarbon from Jurassic section in different parts of Kuwait. An integrated approach was adopted for this reassessment. The interpretation of 3D seismic data brings out the structural features which are in sharp contrast to the earlier subsurface picture. Three sets of fault are mapped which have divided the main Burgan structure into seven different blocks. Four, out of these seven bloks were tested by earlier wells leaving other three blocks as totally untested and unexplored. Two sections in Middle Marrat are found to be hydrocarbon bearing. The upper section was tested in five out of six wells drilled earlier, but no Oil Water Contact (OWC) could be inferred. A re-look at the reservoir engineering data in couple with petrophysics and structural synthesis helps to infer three probable OWCs. The lower section, approximately 250 ft below the deepest inferred OWC in the lower part of Middle Marrat, was tested in one well and found oil bearing. The present study shows that the earlier wells were not placed at the optium places with respect to the structural configuration and as a result the potential of the reservoir of Jurassic section could not be ascertained properly from previous exploratory efforts. The hydrocarbon bearing zones of Middle Marrat have been identified from Sequence Stratigraphic analysis as a part of Highstand Systems Tract that continues laterally towards north in the Magwa field. The present study has enhanced the prospectivity of the Jurassic sediment in the area pointing out the necessity of re-assessment of hydrocarbon prospect for partially explored areas by continuous revision incorporating the latest data sets, experiences, concepts and technological advancements.
Tomography Powered 3-Phase Flowmetering in the Wet Gas Regime
Authors: Wee Arnstein , Skjaeldal Ingve Morten , Streeton Richard
Published: December 2009

Multiphase meters were initially developed by several companies during the 1990's and thus far, operators have gained about 10 - 15 years of experience in using them. However, results during this period have been mixed, and many operators, having trialed and tested all technologies began to express concerns in the reliability, accuracy and sensitivity of conventional technologies [1]. A particular concern was the accuracy of multiphase metering in the wetgas regime.

The particular case where the gas fraction (GVF) of a multiphase stream is above 92–95% is denoted wetgas. The vast majority of gas producers contain small volumes of hydrocarbon liquid and water and wetgas metering thus represents a growing interest for operators. Even in cases where the reservoir only produces gases, liquid condensation will usually occur in the flow lines with falling temperature and pressure -causing wetgas conditions at the metering location.

The benefits of accurate and reliable wetgas metering systems are many and varied:- Allocation in multi-well/multi-operator applications- Saline water detection and measurement- Real time reservoir monitoring, and well testing- Flow assurance and production optimisation- Installation simplification in challenging developments with multi-well and subsea tie-back configurations- E-field solutions

A few two-phase wetgas meters are commercially available in the market today, being able to discriminate between gas and liquid or between hydrocarbons and water. The MPM meter is, as far as we know, the only multiphase meter that is capable of independently measuring all three phases in addition to the salt content in a wetgas stream.

This paper gives an overview of the MPM technology, describes the extensive qualification program that was undertaken to prove the technology and provides test data to demonstrate the superior performance of the meter at high GVF conditions - particularly in relation to highly accurate water flowrate measurements.
Production Optimization of Multi-Lateral Wells Using Passive Inflow Control Devices
Authors: Hembling Drew E. , Simonian Sam , Salerno Giovanni , Berberian Garo , Al-Mumen Adib Abdulmohsen
Published: December 2009

Passive ICDs (Inflow Control Devices) are being used to enhance performance of horizontal wells in unfavorable environments such as non-uniform permeability and/or pressure variations along horizontal sections. This is the first ever attempt, to the best of our knowledge, at using ICDs to manage inflow from two laterals connected to a motherbore. Furthermore, this well is a 3 7/8" openhole multi-lateral with a 2 7/8" ICD completion.

This paper presents how passive ICD completion technology is used to optimize well productivity in a multi-lateral well. This carbonate well was sidetracked to increase reservoir contact and create the required multi-lateral. Subsequently, the ICDs were run, and to confirm the inflow profile along the length of the of the ICD completion, a PLT survey was conducted. The actual rate and inflow profile compared favorably with the predictions as per design of the ICD completion. This paper will show the well design, the actual PLT vs modeled results, and discuses future utilizations for this technology.

The key factor in the success of this project was the use of the 2-7/8" ultra-slim ICD completion, which was optimized based on numerous wellbore hydraulic simulations, to determine the appropriate number of ICD units and compartments to balance the required off-take from each lateral, and from individual compartments in the motherbore section.

Introduction

Horizontal multi-lateral wells have been used globally to enhance reservoir contact and ultimately improve well performance1. Variations in permeability, reservoir pressure, reservoir fluid properties, and frictional pressure drop along horizontal sections, can create non-uniform inflow profiles, which can lead to early breakthrough of water or gas in reservoirs with an aquifer and/or gas cap. Breakthrough typically occurs in regions of high permeability or at the heel of the lateral section in homogenous reservoirs. This ultimately leads to a reduction in reserve recovery and well performance.

The use of ICD completions to effectively manage non-uniform inflow profiles has been described in past publications2. In this completion, ICD's were used to control the inflow from two laterals and along the motherbore.

Background

The subject well was originally drilled and completed as an open hole vertical oil producer in 1966. By 1977, the well had developed a casing leak and consequently, a 4½" liner was run to isolate the leak. Initially, the well produced 5 MSTBD dry oil. Water production began in 1998 and it reached 50% water cut by the end of 2007; consequently, the well was plugged back to within 20 feet from the top of the reservoir to minimize water production; however, it was with limited success. Due to continued water production, the well was worked over in 2008 and converted to a tri-lateral well with 3-7/8" short radius horizontal laterals to acess the top 20 ft of the reservoir allowing continued recovery of dry oil.
Prediction of ovarian hyperstimulation syndrome in women undergoing in vitro fertilization
Authors: KAHNBERG ANNIKA , ENSKOG ANDERS , BRÄNNSTRÖM MATS , LUNDIN KERSTI , BERGH CHRISTINA
Published: December 2009

Objective. Ovarian hyperstimulation syndrome (OHSS) is a severe side effect of in vitro fertilization (IVF). The aim of this study was to identify independent predictors which could be used to identify IVF patients at risk for OHSS. Design. A prospective observational study. Setting: University hospital. Population. Six hundred and twenty‐four consecutive patients treated with conventional IVF or intracytoplasmic sperm injection. Methods. Observational clinical data were compared. Main outcome measures. Patients who developed OHSS were compared with patients who did not develop OHSS using univariate and multivariate analyses. Results. Twenty‐eight patients developed OHSS considered as severe and requiring hospitalization. Independent predictors of OHSS were number of follicles at oocyte aspiration, number of aspirated oocytes and total number of medium/large‐sized follicles before hCG. When these variables were combined in a receiver operating characteristic (ROC) curve they showed a sensitivity of 82.1% and a specificity of 90% for OHSS. The only independent predictor of OHSS before the ovulatory dose of hCG was total number of medium/large‐sized follicles before hCG. A corresponding ROC found a sensitivity of 82.1% and specificity of 79.4%. Conclusion. Prediction of OHSS that is of severity requiring hospitalization can be done with reasonable high sensitivity and specificity both before and after the ovulatory dose of hCG.
The effect of hysterectomy or levonorgestrel‐releasing intrauterine system on lower abdominal pain and back pain among women treated for menorrhagia: a five‐year randomized controlled trial
Authors: HELIÖVAARA‐PEIPPO SATU , HALMESMÄKI KAROLIINA , HURSKAINEN RITVA , TEPERI JUHA , GRENMAN SEIJA , KIVELÄ AARRE , KUJANSUU ERKKI , TUPPURAINEN MARJO , VUORMA SIRKKU , YLISKOSKI MERJA , PAAVONEN JORMA
Published: December 2009

Objective. The purpose of this study was to evaluate the changes in lower abdominal pain and back pain among women with menorrhagia treated by hysterectomy or levonorgestrel‐releasing intrauterine system (LNG‐IUS). Design. A randomized controlled trial. Setting. Five university hospitals in Finland. Sample. A total of 236 women, aged 35–49 years. Methods. Women were randomly assigned to treatment by hysterectomy (n = 117) or LNG‐IUS (n = 119). Main outcome measures. Frequency and intensity of lower abdominal pain and back pain were evaluated by questionnaires at baseline and after 6 months, 12 months and 5 years. Results. By six months, women in both groups had less frequent back pain than before treatment (p < 0.001). Lower abdominal pain decreased only in the hysterectomy group (p = 0.02) with significant differences between the groups. Between 12 months and 5 years, frequency of lower abdominal pain (p = 0.05) and back pain (p = 0.002) decreased more in the LNG‐IUS group than in the hysterectomy group. Between baseline and five years, the lower abdominal pain score (including frequency and intensity of pain) decreased in both groups (p < 0.001, p = 0.01). Back pain score decreased only in the LNG‐IUS group and the difference between the groups was significant (p = 0.02). However, some women experienced more pain after both treatments than before treatment. In multivariate analyses, LNG‐IUS use was associated with a decrease in lower abdominal pain and back pain. Conclusions. In the treatment of menorrhagia, both hysterectomy and LNG‐IUS decrease lower abdominal pain. LNG‐IUS use, but not hysterectomy, has beneficial effects on back pain.
Costs and health‐related quality of life effects of hysterectomy in patients with benign uterine disorders
Authors: TAIPALE KAISA , LEMINEN ARTO , RÄSÄNEN PIRJO , HEIKKILÄ ANNE , TAPPER ANNA‐MAIJA , SINTONEN HARRI , ROINE RISTO P. ,   The HUS QoL Study Group
Published: December 2009

Objective. To gain knowledge about the utility of hysterectomy in a real‐world setting and to relate the utility of the intervention to its costs. Design. Prospective observational study. Setting. University referral hospital in Helsinki. Population. A total of 337 women entering for routine hysterectomy due to a benign disease (210 benign uterine or ovarian cause, 20 endometriosis, 51 uterovaginal prolapse, 56 menorrhagia). Methods. Patients filled in the 15D health‐related quality of life (HRQoL) questionnaire before and six months after the operation. Costs were examined from the perspective of secondary care provider. Benefits of surgery were extrapolated till the end of remaining statistical life expectancy of each woman in the prolapse group and until menopause in the other groups. Main outcome measures. HRQoL and cost per quality‐adjusted life year (QALY) gained. Results. Mean [standard deviation (SD)] HRQoL score (on a 0–1 scale) in the whole group improved from the preoperative of 0.905 (0.073) to 0.925 (0.077) six months after the operation (p < 0.001). The largest mean (SD) improvement was seen in patients with endometriosis [0.048 (0.067)] followed by those with menorrhagia [0.024 (0.054)], benign uterine or ovarian cause [0.018 (0.071)], and prolapse [0.017 (0.055)]. In the whole group, the intervention produced a mean (SD) of 0.222 (1.270) QALYs at mean (SD) direct hospital cost of €3,138 (2,098). Consequently, the cost per QALY gained in the whole group was €14,135 varying from €3,720 to 31,570 in the disease groups. Conclusions. The cost per QALY gained for hysterectomy for benign uterine disorders is strongly dependent on the indication for surgery.
Use and abuse of oxytocin for augmentation of labor
Authors: SELIN LOTTA , ALMSTRÖM ELISABETH , WALLIN GUNNAR , BERG MARIE
Published: December 2009

Objective. To investigate the use of oxytocin for augmentation of labor and its relation to labor progress and delivery outcome. Design and setting. A retrospective observational study undertaken in a Swedish hospital during 2000–2001. Sample. Singleton pregnancies at ≥ 37 weeks of gestation with cephalic presentation and spontaneous onset of labor. Methods. Data were collected from 1,263 clinical records. The partogram was used to diagnose labor dystocia (LD). Main outcome measures. Prevalence of oxytocin administration, LD and operative delivery. Results. Oxytocin was administered to 55% of the women (75% of primiparas and 38.1% of multiparas); a majority did not meet LD criteria. LD frequency was 19.8% (32.7% in primiparas and 7.4% in multiparas). Oxytocin was started both ‘too early’ and ‘too late’ in relation to the diagnosis of LD. Cesarean section (CS) was performed on 17.1% of primiparous and 2.4% of multiparous oxytocin recipients with LD, compared to 2.3 and 1.5%, respectively, of oxytocin recipients without diagnosed LD. Conclusions. Oxytocin augmentation was undertaken in an unstructured manner; some women were inadequately treated and others were treated unnecessarily. Oxytocin recipients with LD underwent operative delivery to a higher extent than oxytocin recipients without LD, suggesting that the main reason for CS was the underlying problem of LD rather than the oxytocin augmentation itself.
Influence of the maternal birth status on offspring: A systematic review and meta‐analysis
Authors: SHAH PRAKESH S , SHAH VIBHUTI ,   on behalf of Knowledge Synthesis Group on Determinants of Preterm/LBW births
Published: December 2009

Background. Maternal low birth weight (LBW), preterm birth (PTB) and small‐for‐gestational age (SGA) birth status have been suggested as precursors for an infant being born LBW, PTB or SGA. Objective. To systematically review the risks of infant LBW/PTB/SGA among mothers who were LBW/PTB/SGA. Search strategy. Medline, Embase, CINAHL and bibliographies of identified articles were searched for English language studies. Selection criteria. Studies reporting association between maternal birth status and LBW, PTB or SGA outcomes were included. Study quality was assessed for biases in selection, exposure assessment, confounder adjustment, analyses, outcomes assessment and attrition. Data collection and analysis. Unadjusted data from included studies were extracted by two reviewers. Summary odds ratio (OR) and confidence intervals (CI) were calculated using random effect model. Main results. Twenty‐two studies of low to moderate risk of biases were included. Maternal LBW was associated with infant LBW (12 studies, 525,706 participants, OR 2.23, 95% CI 2.11–2.35), PTB (six studies, 331,121 participants, OR 1.57, 95% CI 1.43–1.71) and SGA (three studies, 324,357 participants, OR 1.83, 95% CI 1.43–2.33). Maternal PTB was associated with infant PTB (seven studies, 282,616 participants, OR 1.41, 95% CI 1.26–1.59) and SGA (three studies, 41,590 participants, OR 1.33, 95% CI 1.08–1.64). Maternal SGA was associated with infant PTB (OR 1.58, 95% CI 1.06–2.37) and SGA (OR 2.64, 95% CI 2.28–3.05). Conclusions. Maternal LBW, PTB or SGA status was associated with their children's LBW/PTB/SGA status. Maternal birth status should be included in risk assessment when planning pregnancy care for individual women.
Optimizing patient radiation dose in intervention procedures
Authors: Chida Koichi , Kato Mamoru , Saito Haruo , Ishibashi Tadashi , Takahashi Shoki , Kohzuki Masahiro , Zuguchi Masayuki
Published: December 2009

Although numerous patients derive great benefit from interventional procedures, a serious disadvantage associated with interventional procedures is patient radiation dose. Therefore, interventionalists should be aware of how to reduce the radiation dose to their patients. Currently, no conclusive method for reducing radiation dose is available for interventional procedures; hence, it is necessary to combine various methods. In addition, in order to reduce the radiation injury risk in interventional procedures, evaluation of patient radiation dose is essential. Generally, the tradeoff for a decrease in radiation dose is a loss in image performance. Therefore, optimization of radiation dose and image performance is important in interventional procedures.
Seasonal Diversity and Population Status of Waterbirds in Phewa Lake, Pokhara, Nepal
Authors: Giri Bikash , Chalise Mukesh Kumar
Published: December 2009

The study (2007-08) was carried out in Phewa Lake which is one of the largest lake systems in Nepal to evaluate seasonal diversity and population status of waterbirds. A total of 39 waterbird species belonging to 17 families of 5 orders was recorded. The highest number of species (31 species) was found in December and January. Winter was the most diverged season in terms of number of species (35 species) and summer and autumn by 17 species. January had the highest (1584) and September the lowest (345) waterbird population. Out of 39 species, 15 species were winter visitors, 10 resident, and 4 rare winter visitor. The highest diversity ( H =2.6228) was found in February and lowest ( H =1.2014) in June. The value of evenness (Jacob's coefficient) was higher (0.8485) in February and lowest (0.4555) in June. During June, 69.92% (616 individuals) of the total population (881) constituted only Cattle Egret. The dominancy was found highest (C=0.5058) in June and lowest (C=0.1020) in February. The bird communities of summer and autumn were more similar (S=0.7059) than the summer and winter (S=0.5). The fluctuation in number of individuals of bird species was found unrelated to seasons (months) (F=1.71, df = 8, 342, P ≤ 0.05). The species richness was found different in different seasons (months) (Χ2=29.34, df = 8, P ≤ 0.05). Detail study of bird diversity and population status with periodic monitoring in Phewa Lake is recommended for their conservation and management as a whole. Key Words: Phewa lake, wetland, waterbirds, diversity, population  DOI: 10.3126/jowe.v1i1.1568 Journal of Wetlands Ecology Vol.1(1/2) 2008, p.3-7
A Review of Carbon Dynamics and Sequestration in Wetlands
Authors: Adhikari Shalu , Bajracharaya Roshan M , Sitaula Bishal K
Published: December 2009

Wetlands are among the most important natural resources on earth. They provide a potential sink for atmospheric carbon but if not managed properly, they become a source of green house gases. However, only limited studies have been conducted to assess the roles and potentials of wetlands in carbon sequestration. Wetlands occupy approximately 5% of the total land area in Nepal, some of these being of international importance. However, there are major knowledge gaps in accurately quantifying carbon stored in them, as well as their carbon sequestration potential. Therefore, further research is needed to better understand the processes of carbon sequestration in wetland vegetation and soils. Key words: wetland, sink, carbon sequestrationDOI: 10.3126/jowe.v2i1.1855 Journal of Wetlands Ecology, (2009) vol. 2, pp 41-45
Livelihood Option from Minor Forest Produce: Context of Non Timber Forest Product and Poverty Reduction in Mid Hills of Nepal
Authors: Acharya Ganesh Raj , Koirala Pashupati Nath , Neupane Laxman , Devkota Suvas Chandra
Published: December 2009

The paper recognizes Non Timber Forest Products (NTFPs) as contributing factor for improving livelihoods of the rural people. Existing trend of NTFPs in Rolpa district reveals high level of its potential where a single Malagiri tree in the one of the VDC of the district has yielded profit of 15, 000 NRs. in gross. The study supports idea that the quality of life can be secured through the promotion of NTFP as an additional crop for safety net.  Major outlet clusters for NTFP trade and marketing of the Rolpa district are Sulichaur and Holeri regions where mostly NTFP species were found to be traded.  Malagiri, Timur, Ritha and Allo are major local species that have a high level of demand in the market. As a result, people have started cultivating a few species in their farmland too. Lack of knowledge and skill in the production of standard commodity has compelled district people towards traditional NTFP farming approach where they are not reaping optimum benefit. Realizing the potential of NTFPs in the district, it is important to consider modernizing the processing of raw material, development of transportation network and undertake facility for the producers. Such intervention could be a major breakthrough in the poverty reduction of the district and securing quality of life. Key words: NTFP, Livelihood, Community, MarketingDOI: 10.3126/jowe.v2i1.1858 Journal of Wetlands Ecology, (2009) vol. 2, pp 57-66
Discovering Robertson Davies
Authors: Grant Judith Skelton
Published: December 2009

That Davies was alive throughout the years of preparation and publication of his biography was a mixed blessing. It made it possible to observe him in many contexts, and his excellent memory meant that much could be learned from interviews. But his memory was not perfect and there were parts of his life he shied away from and papers he chose not to make available. If balance and accuracy were to be achieved, interviews with friends, enemies, and neutral observers were needed, as was a thorough examination of the record – newspapers edited by Davies' father, his own editorials and articles, his manuscripts and professional correspondence, private letters still in the hands of correspondents, diaries (insofar as he was willing to make them available), and the like. While Man of Myth was in preparation, he was sufficiently skittish that the possibility he might withdraw from the project was ever present. He had much to say about the difficulties of writing biography in two novels and in many letters, but he claimed he'd never read his own biography so he would not have to answer questions about it.
Far from the Centre: Robertson Davies and a Provincial Encounter with James Joyce
Authors: McIntyre John
Published: December 2009

Robertson Davies' significant role in promoting and disseminating the work of James Joyce in the pages of the Peterborough Examiner is exemplified in his claim to have introduced Joyce's work to the emerging literary critic Hugh Kenner. An advocate of Joyce and of modernist literature more broadly, Davies sought, against the backdrop of a provincial setting that both frustrated and motivated him, to soften some of modernism's difficult edges for his readers and to dispel charges of inaccessibility. In both the Examiner and Saturday Night he argued for Joyce's universality – of relevance to readers everywhere. Such claims follow from Davies' larger belief in the importance of fostering literary culture in Canada, the ultimate success of which could be seen in the work of figures such as Kenner. The view of Joyce and of literary modernism that Davies framed for his readers has considerable implications not only for our understanding of Davies, but also for Joyce studies. The assumptions and imperatives that motivated Davies' promotion of modernism meant that the Joyce that Kenner first encountered was a complex figure, at once provincial and cosmopolitan.
Multiscale modeling of polymers at interfaces
Authors: Varnik Fathollah , Binder Kurt
Published: December 2009

A brief review of modeling and simulation methods for a study of polymers at interfaces is provided. When studying truly multiscale problems as provided by realistic polymer systems, coarse graining is practically unavoidable. In this process, degrees of freedom on smaller scales are eliminated in favor of a model suitable for efficient study of the system behavior on larger length and time scales. We emphasize the need to distinguish between dynamic and static properties regarding the model validation. A model which accurately reproduces static properties may fail completely when it comes to the dynamic behavior of the system. Furthermore, we comment on the use of the Monte Carlo method in polymer science as compared to molecular dynamics simulations. Using the latter approach, we also discuss results of recent computer simulations on the properties of polymers close to solid substrates. This includes both generic features (as also observed in the case of simpler molecular models) as well as polymer specific properties. The predictive power of computer simulations is highlighted by providing experimental evidence for these observations. Some important implications of these results for an understanding of mechanical properties of thin polymer films and coatings are also worked out.
Molten salt synthesis and phase evolution of Ba(Cd1/3Nb2/3)O3
Authors: Deng Jinxia , Chen Jun , Yu Ranbo , Liu Guirong , Xing Xianran
Published: December 2009

Ba(Cd1/3Nb2/3)O3 powder with an octahedral shape stacked by small particles was successfully synthesized by the molten salt synthesis method at a low temperature of 850 °C, which was much lower than the columbite method, two-step solid-state reaction process. Thermogravimetry and differential thermal analysis curves combined with X-ray diffraction analysis determined the phase evolution of Ba(Cd1/3Nb2/3)O3 powder at relative high temperature. Furthermore, Raman results showed that the Ba(Cd1/3Nb2/3)O3 powder had a trigonal order structure. It was indicated that the “template formation mechanism” and crystal habit growth which obeyed the model of anion coordination polyhedral, play an important role in the formation and growth processes. The resulting ceramics exhibited favorable dielectric properties.
Investigation of fatigue fracture of generator-rotor fan blades
Authors: Sameezadeh Mahmood , Farhangi Hassan , Soltani Nasser , Ataei Peyman
Published: December 2009

The failure of a rotating axial flow fan of a 123 MW electric power generator unit is analyzed. The fan was mounted on the generator-rotor at the turbine end. Initial investigations showed that three fan blades had fractured just about 11 h after resuming operation following the last overhaul, causing extensive damage to the unit. The failure of the blades was investigated using fractographic and microstructural characterization techniques as well as mechanical evaluations. Based on fractographic observations high cycle fatigue was identified as the failure mechanism. Formation of multiple primary cracks which coalesced during crack growth to form shallow and semi-elliptical crack geometry was indicative of the influence of additional bending stresses, probably resulting from excessive vibrations. Using fracture mechanics principles, the magnitude of the maximum stress at the time of final fracture of the first broken blade was estimated to be more than 3 times higher than the design operating stress. Furthermore, crack growth lifetime of the blades was evaluated using FRANC3D software. It was found that an operating period of just about one hour was required for small initial cracks to propagate to final failure under the action of excessive bending stresses.
Experimental study of phase relations in the ZrO2–La2O3–Y2O3system
Authors: Fabrichnaya Olga , Savinykh Galina , Schreiber Gerhard , Seifert Hans J.
Published: December 2009

Thermodynamic calculations in the ZrO2–La2O3–Y2O3system were used to select compositions for experimental investigations. The selected compositions were investigated using X-ray diffraction, scanning electron microscopy combined with energy dispersive X-ray spectroscopy and differential thermal analysis after prolonged heat treatment at 1250, 1400 and 1600 °C. The X-ray diffraction investigations indicated stability of the La2O2–A + (La,Y)2O3–B + La2Zr2O7and (La,Y)2O3–B + La2Zr2O7+ LaYO3-perovskite phase fields at 1250 °C, which is contrary to results found in the literature. The differential thermal analysis of the ZrO2-45.8La2O3-20.8Y2O3composition heat treated at 1250 °C showed no transformations up to 1500 °C. Two peaks were indicated at temperatures above 1450 °C: the first peak at 1530 °C could be attributed to the processes of Y2O3dissolution and disordering in the pyrochlore phase and the second peak at 1580 °C to transformation of perovskite to monoclinic B phase. The solubility of Y2O3in pyrochlore phase occurs by Y+3substitution of both Zr+4and La+3ions.
Microstructure and properties of violin strings made of metastable austenitic steel
Authors: Haas Rüdiger , Degischer H. Peter , Pongratz Peter , Pyzalla Anke R.
Published: December 2009

The strings of musical instruments are frequently made of stainless steel wires. Samples taken from consecutive steps of wire drawing showed the kinetics of deformation-induced martensite formation from metastable austenitic feedstock. Stacking fault and twin formation were described by transmission electron microscopy. The progress of martensitic transformation was accompanied by an increase in defect density and in micro-strains determined by synchrotron X-ray diffraction. The initial fall in the Young's modulus determined by tensile tests was accompanied by a drastic reduction in domain size and in grain diameter. Texture and phase transformation at the wire surface were measured by X-ray diffraction. The deformation-induced martensite formation has been described in its nucleation, growth and saturation stages. These three stages were defined by the correlation of the evolution of the microstructural features in the course of the wire drawing process.
Microstructure of Ti-6Al-4V specimens produced by shaped metal deposition
Authors: Baufeld Bernd , Biest Omer van der , Gault Rosemary
Published: December 2009

Shaped metal deposition is an innovative technology, which creates near-net shaped components by weld deposition and saves time and material due to the absence of further machining. For Ti alloys this is a big advantage, since these alloys are difficult to shape and also very expensive.

Ti alloys are very sensitive to the thermal history and shaped metal deposition introduces for each welding step an additional temperature gradient leading to different microstructures in different regions. Regions which were in the single β phase field during the last welding show a fine needle like microstructure, while regions within the α + β phase show coarser lamellae forming a Widmanstätten structure.
Surface tension of liquid Al–Cu binary alloys
Authors: Schmitz J. , Brillo J. , Egry I. , Schmid-Fetzer R.
Published: December 2009

Surface tension data of liquid Al–Cu binary alloys have been measured contactlessly using the technique of electromagnetic levitation. A digital CMOS-camera (400 fps) recorded image sequences of the oscillating liquid sample and surface tensions were determined from analysis of the frequency spectra.

Measurements were performed for samples covering the entire range of composition and precise data were obtained in a broad temperature range.

It was found that the surface tensions can be described as linear functions of temperature with a negative slope. Moreover, they monotonically decrease with an increase in the aluminium concentration. The observed behaviour with respect to both temperature and concentration is in agreement with thermodynamic model calculations using the subregular solution approximation.
Relative effects of Mo and B on ferrite and bainite kinetics in strong steels
Authors: Khare Sangeeta , Lee Kyooyoung , Bhadeshia H. K. D. H.
Published: December 2009

Well–designed cementite–free bainitic steels are important in contributing to unique combinations of strength, toughness and cost. We examine here the relative effects of molybdenum and boron on the kinetics of transformation of austenite particularly into allotriomorphic ferrite and bainite. There are some surprising results on the role of boron, which is found in some circumstances to accelerate the transformation to allotriomorphic ferrite. This, and other features of transformation behaviour are assessed in the context of phase transformation mechanisms.
Enhanced Parametric Railway Capacity Evaluation Tool
Authors: Lai Yung-Cheng (Rex) , Barkan Christopher P. L.
Published: December 2009

Many railroad lines are approaching the limits of practical capacity, and estimated future demand is projected to increase 84% by 2035. Therefore, identifying a good multiyear capacity expansion plan has become a particularly timely and important objective for railroads. An enhanced parametric capacity evaluation tool has been developed to assist railroad companies in capacity expansion projects. This evaluation tool is built on the Canadian National Railway Company parametric model by incorporating enumeration, cost estimation, and impact analysis modules. Based on the subdivision characteristics, estimated future demand, and available budget, the proposed tool will automatically generate possible expansion alternatives, compute line capacity and investment costs, and evaluate their impact. For a particular subdivision, there are two outputs from this decision support tool: a plot that depicts the delay–volume relationship for each alternative and an impact and benefit table that shows the impact of the future demand on the subdivision with different upgrading alternatives. The decision support tool is highly beneficial for budget management of North American railroads.
Impact of Train Type Heterogeneity on Single-Track Railway Capacity
Authors: Dingler Mark H. , Lai Yung-Cheng (Rex) , Barkan Christopher P. L.
Published: December 2009

North American railroads are experiencing rapid growth in traffic demand and increasingly need to expand capacity to accommodate it. Efficient planning of new capacity requires understanding how the mixture of traffic interacts to affect capacity. Different train types can have substantially different operating characteristics, including maximum speed, power-to-ton ratio, and dispatching priority. Heterogeneity in the mix of characteristics of different train types creates greater delays than are created if traffic is homogeneous. Train dispatching simulation software was used to analyze the effect of various combinations of intermodal, unit, manifest, and passenger trains on a hypothetical, signalized, single-track line with characteristics typical of a North American railroad subdivision. Analyses included the influence on delay by various traffic and train characteristics. As has been shown by previous investigators, heterogeneity increases delay, but different types of heterogeneity had differing effects, which has implications for capacity planning. This paper attempts to provide a better understanding of the impacts of various aspects of train type heterogeneity to enable more effective planning and efficient rail operations. The results also suggest certain operating strategies that may reduce the delays caused by train type heterogeneity.