bluuebunny/crossref_metadata_2025 huggingface dataset:
Rejuvenating a High GOR, Light Oil Reservoir Using AICD Completion Technology for Gas Control
Authors: Ahmad Fazeel , Al-Neaimi Ahmed Khalifa , Saif Omar Yousef , Channa Zohaib , Iwama Hiroki , Sarsekov Arlen , El-Sayed Hussein Saad , Konopczynski Michael , Ismail Ismarullizam Mohd , Abazeed Osama
Published: November 2016

The gaint oilfield offshore Abu Dhabi was discovered in 1963 and came online in 1967. Horizontal drilling was introduced in 1989 to enhance recovery efficiency, leading to a large stock of horizontal wells to date. With the maturation and depletion of the field, areas of high, non-associated gas saturation have developed, and subsequent breakthrough to the horizontal production wells have resulted in high GOR that is above the shareholder's guideline. Many wells have been shut in due to high GOR.

Controlling uneven production and early gas breakthrough are the main challenges to achieving target production and maximum hydrocarbon recovery. Inflow control devices (ICDs) create additional pressure drop to balance the production flux, but cannot restrict unwanted effluents ‘gas/water’ once they break through.

The Autonomous Inflow Control Device (AICD) is an active flow control device that delivers a variable flow restriction in response to the properties (viscosity) of the fluid flowing through it. Gas flowing through the device is restricted more than oil. When used in an oil well segmented into multiple compartments, this design prevents excessive gas production when gas breakthrough occurs in one or more compartments.

An evaluation of remedial advanced completion methods was conducted to select the best method of recompleting the shut-in wells and restoring oil production while controlling gas breakthrough. The solution must not only control gas production from zones of the well with high gas saturation now, but must be able to react to future increase in gas saturation in other zones as depletion continues.

The "levitating disk" style AICD is ideally suited to this challenge, with the ability to greatly restrict the production from zones with high gas volume fractions. Modeling has indicated that total GOR can be reduced by 40% and total gas production reduced by over 60% compared to an open hole completion.

This paper illustrates how AICD technology can enable operators to re-activate wells shut-in due to high GOR. This paper also describes a systematic approach for modelling flow in horizontal wells with AICD's, and presents an evaluation comparing different completion technologies used to control excessive gas production and maximize oil recovery.
Development of New Geopolymer Material as Alternative Plug for Cement in CO2 Sequestration
Authors: Faqir Naim M. , Elkatatny Salaheldin , Mahmoud Mohammd , Shawabkeh Reyad
Published: November 2016

Maintaining CO2 in gas and oil wells is a challenge in CO2 sequestration. The downhole forces on the pumped cement between the casing and the drilled formation lead to failure of cement, and hence the well integrity can be affected. Furthermore, the prolong interaction between the stored CO2 and the casted cement can lead to corrosion of embedded well tubulars. This deterioration of the casted well is a major cause of cracking and channeling of the cement matrix resulted in early gas migration. Such problems can lead to early workover jobs or shutting-down some wells that resulted in losing its productivity.

This work aims at developing a new material from clay that has a high resistance to CO2 in upstream for plugging CO2 storage wells. The synthesis conditions as well as the adsorption-desorption characteristics at simulated well condition will be presented. Then a model that simulates the adsorption isotherms and the thermodynamic properties for the interaction between the developed material and the CO2 will be investigated.

The developed material demonstrated lower porosity and permeability, and higher compressive strength than the conventional cement plug. Thermogravimetric and thermal stability of the developed geopolymer sample showed a minimal variation in weight loss with incremental heating up to 420 °C. Adsorption-desorption of CO2 at various modeled temperature showed an endothermic and spontaneous process with maximum adsorption capacity of 800 mg/g obtained at 660 psi. Higher pressure lead to more storage capacity with physisorption hysteresis curves. The novelty of this work is the development of new geopolymer material that can substitute the conventional cement plug for upstream carbon capture and sequestration.
Seismic Technologies for Unconventional Reservoir Development
Authors: Johnston Rodney
Published: November 2016

Unconventional reservoirs have revolutionized the global resource supply picture and represent significant opportunities for countries around the world. Whether rock matrix or fluid properties deviate from what we may consider conventional, success in this environment requires a close integration between both subsurface characterisation and efficient engineering practices. Among the disciplines involved, geophysics plays a role in describing the sub-surface and where to develop: rock type, fluids and fractures through seismic-derived attributes. The ability to convert amplitudes from seismic into a desired rock property attribute isolated from other properties depends on: 1) the rocks and fluids under investigation, 2) acquiring and processing high quality seismic indicative of the reflection process deep underground, and 3) the particular model used for wave propagation and reflections in the earth. Microseismic, as a technqiue which monitors changes in stress, provides a guide to how the reservoir responds dynamically to stimulation and production. Based on the same wave propagation in the earth, the two techniques are linked and complimentary. Due to the heterogeneity associated with unconventional reservoirs and their depositional environments, data acquisition choices are key to unlocking detailed and robust information about the rocks and fluids through processing and analysis. Factors important for the long-term technology vision required for unconventional reservoir development are acquisition market solutions and thinking in the industry: equipment being developed and its suitability for operations in different land environments with the intensity we desire. We recognize that efficient and cost effective dense sampling of sources and receivers is what we wish to aim for. Dense spatial sampling stabilizes the higher-order attributes we need, and a more complete description of the elastic earth provides complimentary information using P- and S-waves acquired with multi-component sensors. While BP and the industry are working on the efficiency side, we need to continue to think of novel ways to produce the right equipment in large quantities such that adequate 5D wavefield sampling becomes practical.
Changing Industry Dynamics and the Skills Imperative
Authors: Raza Mohsin , Hussain Naeem ul
Published: November 2016

Objectives / Scope

The upstream oil and gas industry has undergone some salient changes that are having a domino effect on human resources. Exploration projects are increasing in complexity with deeper wells, more remote geographics, necessitating a greater role of technology and skills. Due to a downwards trend in oil price, many companies are either downsizing or making their employees do more with less.

This paper explores the impact of these trends on the mandate of HR which is shifting from a back office function to a new role as a key strategic partner at the heart of the company's operations.

Methods, Procedures & Process

In May 2012, Pakistan Petroleum Limited (PPL) contracted Schulumberger Business Consulting (SBC) to review the suitability of the organizational structure and growth pattern in consonance with the company's growth strategy. An assessment was carried out of manpower requirements against industry benchmarks similar to size and business of PPL both in terms of production / reserves and projects.

As a consequence of this study an Online Employee Appraisal Process (OEAS) was developed by PPL – aimed at leveraging analytics in human capital management. Based on empirical evidence collected through OEAS the company has improved its ability to develop and deploy its people with greater efficiency. Skill management, fortified by analytics forms the basis of improved company performance.

Based on PPL's experiences and research this paper will focus on issues and related strategies to address the current challenges faced by the company. The paper will consider the future of work in the Oil and Gas Industry and how analytics are transforming talent, including: The use of technology as a talent multiplier.

Results, Observations, Conclusions

The capability to develop and enrich human capital and, at the same time, to respond to technological advances, has become a major differentiating factor for company's who attract, nurture, motivate and retain their work force from those who do not. This paper will interest organizations wanting to strengthen their internal human factors capability.
Zero Discharge in SARB Islands
Authors: Al-Wahedi Khaled Ahmed , Al-Kindi Rashid , LeBlanc John , Sultan Emad , Mehtar Mohammed , Elatreche Bassam , Kasem Youssef , Abu-Jarad Musbah Adnan , Banda Maria Eugenia
Published: November 2016

In alignment between ADNOC HSE Codes of Practice and ADMA HSE Policies, the SARB Artificial Islands were designed as zero discharge operations. The goal of protecting the environment through zero discharge during drilling operations has never been sought in the area previously. This presented a unique challenge to the team and was essential to formulate a technically and economically feasible strategy for drilling waste collection, handling and disposal while ensuring no discharge to the sea and protection of the marine environment.

Zero discharge has been accomplished successfully through several initiatives including cuttings re-injection through dedicated Cuttings Re-Injection Wells (CRI), containment of any drilling fluids or other discharges associated with rig activities through the use of spill containment systems on the rig, flaring operations conducted through a green burner boom, re-injection of produced oil during well testing operations back into the reservoir and containment and shipping of cement waste back to onshore for disposal at an approved facility.

To date approximately 500,000 barrels of cuttings slurry and liquid waste has been disposed in the two CRI wells since start of injection at the end of July 2015. Over 1,500 tons of cement waste has been contained and are in the process of being disposed onshore. The green burner booms have been commissioned and are ready for use. During 2016 well testing operations there are plans to reinject 70,000 barrels of crude back into the reservoir. All of these initiatives are contributing to making SARB Artificial Islands a complete zero discharge environment.
Modeling of Hydrocarbons Below Free Water Level in a Major Oil Field in Abu Dhabi UAE and its Impacts on Dynamic Behavior and History Matching
Authors: Kheidri L. H. , Vanhalst M. , Barroso F. , Fadipe A. , Al Hammadi Y. , Al Junaibi F. , Adli M. , Ben Sadok A. , Baslaib M. , Dreno C. , Mel R. , Audigier P. A. , Perroud S. , Vacheyrout A.
Published: November 2016

The presence of residual oil below Free Water Level is common in Middle Eastern fields. This later is explained by the presence of a paleo oil-water contact. An early water movement and sweep of the accumulated oil induced by tectonic events after its charging, has led to the trapping of residual oil below the curent Free Water Level. This theory is also supported by the presence of tarmat above and below this Free Water Level along the paleo oil-water contact.

In the studied field, the analysis of fluid saturation logs, early well tests and initial fluid gradients have led to the definition of the oil-water contact and the Free Water Level at discovery time. The analyses of cored wells and water saturation logs have demonstrated the presence of oil below this Free Water Level which is explained by the presence of a paleo oil-water contact. Furthermore, this analysis has enabled the definition of the geometry of this paleo oil-water contact, which appears to have a curved shape. This geometry has also been confirmed by the presence of tarmat along the defined paleo contact.

Modeling of the water and oil saturations below Free Water Level cannot be achieved by a conventional methodology using a saturation height function. Therefore a specific workflow has been developed. Given that oil saturation below Free Water Level is rock type driven, it could be distributed in 3D as any static property. Water saturation logs were consequently upscaled and populated in 3D using a Sequential Gaussian Simulation algorithm with the rock types as main driver. The resulting grid has been extracted up to the base of the transition zone of the main oil column and merged with the oil saturation grid generated using a saturation height function.

A thorough dynamic synthesis of the field has highlighted a specific dynamic behavior of the water injectors perforated below the Free Water Level. In some specific intervals of the reservoir, high shut-in pressures have been identified. These high pressures can be explained by the presence of residual oil below the Free Water Level which acts as a baffle inducing a partial confinement of the injectors. The implementation of this residual oil in the simulation model reduces the injected water mobility and drastically improves the pressure match.
Multilateral Wells Evaluation Utilizing Artificial Intelligence
Authors: Al-Mashhad Ali S. , Al-Arifi Sulaiman A. , Al-Kadem Mohammed S. , Al-Dabbous Mohammed S. , Buhulaigah Ahmed
Published: November 2016

Multilateral wells are considered to be an advancement revolution in the petroleum industry. The employment of multilateral wells ensured higher drainage and productivity of reservoirs through the utilization of diverse configurations. Achieving higher productivity and maximizing the reach from a multilateral well has highly improved inflow performance relationship (IPR) compared to that of a conventional horizontal well under certain conditions. Several analytical models have been developed to estimate the average oil flow rate of multilateral wells by utilizing reservoir parameters to come up with decent correlations for better accuracy. These models are accompanied with uncertainties and limitations due to the complexity of multilateral wells. Artificial Intelligence (AI) techniques have been proven to predict various parameters associated with high uncertainties in the oil industry. One of these methodologies is Artificial Neural Networks (ANN) which was utilized in this paper as new approach to predict the average oil flow rate of multilateral wells though the use of some reservoir parameters along with flowing wellhead data.

As a comparable method, an analytical model was used to calculate the flow rate from several multilateral wells to quantify the value of utilizing ANN against other methods or correlations. Borisov's correlation that was developed for estimating the productivity of multilateral wells of planar configuration was used to calculate the oil flow rate of the multilateral wells and compared the results against actual average oil flow rates. Additionally, PROSPER software was utilized to estimate some wells' parameters including Productivity Index (PI) and flowing bottomhole pressure (FBHP) for oil rate calculations.

Rigorous statistical error analyses have been obtained from ANN method and Borisov's correlation. The overall regression correlation coefficient was calculated to be 0.97 for ANN which shows a strong matching between predicted and actual field values with an overall absolute error of 7.85%. High divergence was found between oil rate calculated from Borisov's correlation and the actual average oil rate with an error greater than 50%. This indicates the actual advantage of the ANN method against other correlations.

This paper discussed a new method for predicting average oil flow rates for multilateral wells using surface and reservoir parameters obtained from field data via the employment of Artificial Intelligence modeling. A model was constructed for enhancing the prediction of oil flow rate for multilateral wells and resulted in a great prediction accuracy proved by field data comparison.
Development of Cost Saving Cantilevered Workover Solution for 4-Legged Self-propelled Jack Up barge
Authors: Sakapaji K , Moffatt J , Preston Mark , Harvey Mark , Lingsten Martin , Nesse Kjetil , Thomassen Torstein
Published: November 2016

This paper sets out the development of a cantilever system for a self-propelled, self-elevating support vessels (SESVs) also known as jack/up barge or lift boat to support well intervention and workover.

Historically, vessels have been designed to operate within a limited segment of the well field life cycle. With Well intervention, a variety of vessels from service boats to drilling rigs have been utilised depending on water death and scope of required operations.

In areas such as MENA, well intervention is conducted either utilising jack up drilling units or jack up barges. Despite their inherent capability for workover, drilling rigs tend to be expensive in terms of both day rate and cost of moving between platform locations as they require mobilisation of tugs to tow them. Drilling rigs are designed to drill wells and are overkill for most Intervention scopes.

Jack up barges particularly self-propelled ones, offer greater efficiencies, quicker servicing times and lower costs. The barges can deploy sooner in a shorter weather window and do not require tugs. This is because such vessels do not require a marine spread to tow them between locations.

Previously, the workover capability of a drilling jack up unit has meant barges have been limited to supporting light well intervention scopes such as Coil Tubing, pumping and Wireline or used only in tender assist mode where heavier work over scopes including P&A and ESP replacement are required.

A study was conducted to establish what modifications could be made to the SESV (Self-propelled jack up barge) to: Improve efficiency and safety of light well intervention (LWI)Incorporate capability to handle heavier work over scope requiring pipe handling

The result was the development of two distinct cantilever systems for installation on the SESV's

Figure 1 Table 1 Cantilever Type Cantilever Capability 1 Work Over Capable Cantilever complete with automated work over unit (rig) to conduct scopes including P&A, ESP and Completion Change out 2 Light Well Intervention Cantilever with interface for a tower to support coil tubing Injector head and wireline sheaves

In this era of low oil prices and cost saving, using a gap analysis approach, separate proven, reliable and efficient solutions have been brought together to offer a safe, highly efficient and economical solution to reduce operational cost in well intervention and work over. In this case it was the development of an innovative cantilever design to align the marine benefits of a 4 legged self-propelled jack up barge and a proven work over rig.
Artificial Lift Production Systems Sizing and Simulation Software
Authors: Elmahbes Reda , Quintero Regulo , Larez Arsenys
Published: November 2016

Determining the proper artificial lift technology for the reservoir requirements and the downhole environment is critical for ensuring economic production rates over the life of a well. To effectively select the best artificial lift solution requires sophisticated tools to simulate and design different artificial lift systems in various production scenarios.

This paper presents the challenges in developing artificial lift software and simulation tool to design, simulate, and effectively apply to different forms of artificial lift systems to improve well efficiency, optimize production and increase ultimate recovery. In addition to determining the best applications for different artificial lift production systems, this software can be used to design application-specific electrical submersible pumping (ESP) systems; electrical submersible progressing cavity pumping systems; rod-driven progressing cavity pumping systems; horizontal surface pumping systems; and gas lift systems and LEAP system. This user friendly software can be used for both fixed speed and variable speed applications. In addition, this software provides sensitivity analysis to quickly evaluate a system design in a wide range of possible operating conditions to maximize production and increase oil recovery.

Information from various wells has been compiled to provide actual field usage data to support the accuracy of the design and simulation tool with different forms of artificial lifts. The artificial lift systems design and simulation tool has the capability to size the right system by conducting sensitivity analysis for wells and projecting different scenarios to maximize well production and enhance system run life. The result shows how the design and simulation tool can be used to optimize production and improve system efficiency.
A Holistic Approach to Develop New Rigorous Empirical Correlation for Static Young's Modulus
Authors: Tariq Zeeshan , Elkatatny Salaheldin , Mahmoud Mohamed , Abdulraheem Abdulazeez
Published: November 2016

Evaluating the elastic parameters of reservoir section are very essential for oil and gas industry in alleviating the risks associated with the drilling and production phases of the reservoir. These parameters are used in the optimization of the well placement, well bore instability, completion design, and draw-down limits to avoid sanding, hydraulic fracturing, reservoir subsidence and in many more applications. To carry out any aforementioned operations, a continuous profiles of rock elastic parameters are needed. Misleading estimation of elastic parameters may wrongly lead to heavy investment decisions and inappropriate field development plans.

Retrieving reservoir rock samples throughout the depth of the reservoir section and performing laboratory tests on them are extremely expensive as well as time consuming. Therefore, these parameters are estimated from empirical correlations. Most of the previous models/correlations were developed using linear or non-linear regression techniques. Artificial intelligence tool once optimized for training can successfully model elastic parameters since these tools are capable of capturing highly complex and non-linear relationship between the input parameters and the target parameter.

The objective of this study is to develop a robust and an accurate model for static Young's modulus based on the wireline logs as an input using three artificial intelligence tools (artificial neural network, adaptive neuro fuzzy inference system and support vector machine). The data on which these AI models are built comprises of more than 680 real field data points from different fields covering a wide range of values. Based on the minimum error and the highest coefficient of determination between actual and simulated data artificial neural network is selected as the proposed AI model to predict static Young's modulus.

A comparison between the static Young's moduli predicted by the proposed model with the published models /correlations reveals that neural network model gives significantly less average absolute percentage error. Finally, a rigorous empirical correlation is developed using the weights of ANN model in order to make the AI black box model as a white box and universal that can be usable for field applications.
New Frontiers for the International Technological Cooperation in the Arctic's Infrastructure Development
Authors: Akimova Irina
Published: November 2016

The remote Arctic was the main destination for romantic geologists for more than 20 years, but now it's a turning point in it's history and the Arctic is becoming a foreign and security policy concern of high order and is in the front line of global energy markets development. Thus, the question how to develop Arctic providing cutting-edge technologies and making it more accessible by developing new routes is a new trend in an international technological cooperation. The ambition of the paper is to provide solutions for international technological cooperation in the Arctic between energy companies under the current economic and geopolitical conditions.
Impact of Heterogeneous Hydro-Geomechanical Properties of Caprock on CO2 Leakage by Tensile Fracture Reactivation During CCS
Authors: Kim G. W. , Kim T. H. , Lee K. S.
Published: November 2016

Mechanical failure of cap rock is one of the main reasons of CO2 leakage from the storage formations. Through comprehensive assessment on the petrophysical and geomechanical heterogeneities of cap rock, it is possible to estimate the pressure distribution more accurately and to predict the risk of unexpected caprock failure. To describe the fracture reactivation and fracture permeability, modified Barton-Bandis model and dual permeability system are applied. Porosity-permeability relationship is calculated with power law. In order to generate hydro-geomechanically heterogeneous fields, the negative correlation between porosity and Young's modulus/Poisson's ratio is applied. In comparison to homogeneous model, effects of heterogeneity are examined in terms of vertical deformation and the amount of leaked CO2. To compare the effects of heterogeneity, heterogeneous models for both geomechanical and petrophysical properties in coupled simulation are designed.

Simulation results show that CO2 leakage occurs after 4-6 years from injection. After 10 year injection with petrophysically heterogeneous and geomechanically homogeneous caprock, CO2 leakage is larger than that of homogeneous model. In contrast, heterogeneity of geomechanical properties is shown to mitigate additional escape of CO2. Vertical displacement of every heterogeneous model is larger than homogeneous model. According to results from model with petrophysically heterogeneous and geomechanically homogeneous caprock, the higher Dykstra-Parsons coefficients (VDP) the larger vertical displacement is obtained. The vertical displacement with petrophysically homogeneous and geomechanically heterogeneous model is also larger regardless of VDP.
Sedimentology and Sequence Stratigraphy Controls on Reservoir Qualities Distribution in High Heterogeneous Carbonate Rocks; Case Study; in a Giant Offshore Oil Field, Abu Dhabi.
Authors: Khemissa Hocine , Al-Shemsi Abdullah H. , Al-Jefri Gassan , AL-Said M. Elhami , de Periere Matthieu Deville , Bijaripour Aita
Published: November 2016

Objectives

The aim of this study is to establish a sedimentological, sequence stratigraphic framework, as well as assessing the controls on the reservoir quality variations. The final output of the study will be used to generate a new Rock Type and produce a robust geological Facies Model. Also; the facies maps will be used to explain the dynamic field behaviour in term of water and gas movements of the field.
The Abundance and Spatial Distribution of Soft Sediment Communities in Tanjung Bungah, Malaysia: A Preliminary Study
Authors: Nur Aqilah Muhamad Darif  , Nur Shakila Abdul Samad  , Sazlina Salleh  , Mahadi Mohammad  , Noor Alia Ahmad Nordin  , Aysha Mariam Mohamed Javeed  , Michelle Glory G Jonik  , Muhamad Hilal Mohd Zainudin
Published: November 2016

Benthic faunal communities are important components in the intertidal zones. The diversity and abundance of the benthic communities are subjected to different natural and anthropogenic disturbances. The study was conducted as one off sampling on 6th November 2013 (1) to investigate the abundance and distribution of soft sediment communities in relation to environmental variables and (2) investigate the changes of population structure and diversity using spatial scales of 1 m, 10 m, and 100 m. Results indicated a total of 110 individuals of macrobenthos consisting of 7 different groups (Annelida, Bivalvia, Crustacea, Gastropoda, Nematoda, Nemertea, Polychaeta) and 4 different groups of meiobenthos (Copepoda, Nematoda, Ostracoda, Polychaeta) consisting 920 individuals were recorded. Dissolved oxygen played the most significant role in affecting the distribution of soft sediment communities while ammonia concentrations only affected marcobenthic organisms. However, sediment grain size did not show significant correlation (p>0.05) on soft sediment communities. Hence, understanding how different properties of benthos respond to changes in environmental variables is crucial in determining how the impacts on the sediment are tolerated by the benthic organisms.
Cloning and Expression of a Subfamily 1.4 Lipase from Bacillus licheniformis IBRL-CHS2
Authors: Nidyaletchmy Subba Reddy  , Rashidah Abdul Rahim  , Darah Ibrahim  , K. Sudesh Kumar
Published: November 2016

We report on the cloning of the lipase gene from Bacillus licheniformis IBRL-CHS2 and the expression of the recombinant lipase. DNA sequencing analysis of the cloned lipase gene showed that it shares 99% identity with the lipase gene from B. licheniformis ATCC 14580 and belongs to subfamily 1.4 of true lipases based on amino acid sequence alignment of various Bacillus lipases. The 612 bp lipase gene was then cloned into the pET-15b(+) expression vector and the construct was transformed into E. coli BL21 (DE3) for bulk expression of the lipase. Expression was analysed by SDS-PAGE where the lipase was found to have a molecular weight of about 23 kDa.
Screening of Potential Free Radicals Scavenger and Antibacterial Activities of Purwoceng (Pimpinella alpina Molk)
Authors: Retno Wahyuningrum  , Pri Iswati Utami  , Binar Asrining Dhiani  , Malikhah Kumalasari  , Rizka Sari Kusumawardani
Published: November 2016

Purwoceng (Pimpinella alpina Molk) is a traditional medicinal plant used for its aphrodisiac values. This plant was originated Dieng Plateu, Central Java, Indonesia. Purwoceng has been reported to contain steroid, flavonoids, glycoside, saponins, tannins, and phenolic. Based on secondary metabolite compounds of Purwoceng herbs, a research need to be done to determine the other potential free radicals scavenger and antibacterial activities of Purwoceng. The objectives of this research are to screen the potential free radicals scavenger activity of in vitro using DPPH (1,1 diphenyl-2-picryl-hydrazil) radicals and NO• (nitric oxide) radicals, and antibacterial activity of Purwoceng. The extraction is done by a maceration method with petroleum ether, ethyl acetate, and ethanol solvent, respectively. Free radicals scavenger test was performed using DPPH radicals and NO• radicals, while antibacterial activity screening was performed using agar diffusion test. The results showed that ethyl acetate extract of Purwoceng has free radical scavenger activity with IC50 53.07 ppm lower than butylated hydroxytoluene. Ethyl acetate extract and ethanol extract of Purwoceng have antibacterial activity against Staphyloccus aureus, Escherichia coli, and MG42 bacterial isolate.
Coastal Macroinvertebrate Study in Penang Island, Malaysia
Authors: Chee Su Yin  , Sim Yee Kwang
Published: November 2016

Land reclamation in Penang began two decades ago and is still rampant with large reclamation projects planned to be executed in the near future. The present study provides the first information on effects of land reclamation in Penang towards the coastal macroinvertebrates. This study assessed the abundance, diversity, and evenness of coastal invertebrates assumed to be the foremost affected when land is reclaimed. Three kinds of areas were focused on: reclaimed, unclaimed (adjacent to reclaimed), and undisturbed. A total of 53 species of macroinvertebrates from 10 classes (Gastropoda, Bivalvia, Polychaeta, Malacostraca, Maxillopoda, Echinoidea, Polyplacophora, Branchiopoda, Scaphopoda, and Holothuroidea) were sampled. Reclaimed areas were moderately rich in species averaging 11 species compared to 7 species in adjacent and 14 in undisturbed areas. Species richness was the highest in Teluk Aling (an undisturbed area) with 22 species, and was the lowest in Gurney Drive (an adjacent area) with 2 species. The average species diversity and evenness on reclaimed land was the lowest with values of 1.9974 and 0.5787, respectively. The diversity was higher by 5.07% in adjacent areas and by 22.92% in undisturbed areas compared to reclaimed areas. Species evenness was 29.75% higher in unreclaimed areas and 17.87% higher in undisturbed areas compared to reclaimed areas. Land reclamation reduces species diversity and evenness, and to a lesser extent, species richness.
Topical Antiacne Drugs Delivery Systems
Authors: Gabriel Tesfaye
Published: November 2016

Background:

Acne vulgaris (commonly called acne) is the most prevalent skin complication of different causes with a higher prevalence in adolescents. Topical administration is used as first-choice therapy in mild acne, whereas for moderate and severe acne, systemic administration is required in addition to topical therapy. Mechanisms by which treatments act are: normalizing shedding into the pore to prevent obstruction, destruction ofP.acnes, suppression of inflammation, and hormonal management.

Objective:

This review focuses on the novel drug delivery systems displaying a strong ground for topical treatment of acne in order to enhance the therapeutic performance of the topical antiacne agents with improved patience compliance and a concomitant reduction in the side effects.

Method:

This literature review was obtained from electronic search on Pubmed, Google Scholars, Researchgate, Scimago, CABI, DOAJ, CiteFactor, GLOBAL HEALTH, Universal Impact Factor, Hinari among many others and also search was conducted on individual journals and manuals.

Conclusion:

Amongst various novel drug delivery systems, vesicular carriers like liposomes and niosomes, micro sponges, microemulsions, solid lipid nanoparticles, hydrogels, emulsifier-free formulations, fullerenes and aerosol foams have been reported as novel topical administration of antiacne drugs. Liposomes have been extensively explored and their ability to optimize and improve topical therapy has been proved by several clinical trials. Microemulsions, microsponges, solid lipid nanoparticles and hydrogels also exhibit a tremendous potential for commercialization.
Audit Quality of Chinese ADR Engagements
Authors: Ghosh Aloke (Al) , Peltier Elisabeth , Xing Cunyu
Published: November 2016

SYNOPSIS

The controversy over Chinese reverse mergers has led to concerns about the audit quality of all U.S.-listed Chinese companies. Because a sizeable number of foreign firms cross-list their shares as American Depositary Receipts (ADRs) issued by U.S. depositary banks (as opposed to direct listings), we study how auditors have managed their audits of Chinese ADRs. Our motivation for examining Chinese ADRs is based on the findings that cross-listing via the ADR process is beneficial for U.S. shareholders. We find that relative to ADRs from countries other than China, and relative to directly listed Chinese companies, Chinese ADRs are more likely to be associated with a Big 4 auditor and are less likely to restate prior-period financial statements. We also find that Chinese ADRs pay significantly higher fees than other emerging market ADRs and Chinese direct-listings. Collectively, these results suggest high audit quality for Chinese ADRs, which is in sharp contrast to the Chinese direct-listing results. Using Tobin's Q as a measure of market value, we find that the stock market rewards Chinese ADRs, indicating that investors incorporate the benefits of higher audit quality when evaluating Chinese ADRs.
Expectations Management
Authors: Versano Tsahi , Trueman Brett
Published: November 2016

This paper analyzes a manager's optimal expectations management strategy in a setting in which the manager provides forecast guidance to an analyst both privately and publicly. Conventional wisdom suggests that managers use private communications with analysts and public earnings forecasts interchangeably to guide analysts' earnings forecasts downward toward lower earnings targets. Our analysis shows that in markets with rational investors, private and public guidance play very different roles in managing expectations, and that managers benefit from downward guidance only in their private communication with analysts. In their public forecasts, they benefit from introducing an upward bias. We explore how the effectiveness of the private and public channels in communicating information to analysts affects managers' incentive to engage in expectations management, and provide a number of empirical predictions. Among other results, we show how reducing private communication between managers and analysts (through means such as Regulation Fair Disclosure) can increase price efficiency, weaken managers' motivation to engage in private, as well as public, expectations management, and increase managers' motivation to provide public disclosures.
Seasonal Dynamics of Academic Achievement Inequality by Socioeconomic Status and Race/Ethnicity
Authors: Quinn David M. , Cooc North , McIntyre Joe , Gomez Celia J.
Published: November 2016

Early studies examining seasonal variation in academic achievement inequality generally concluded that socioeconomic test score gaps grew more over the summer than the school year, suggesting schools served as “equalizers.” In this study, we analyze seasonal trends in socioeconomic status (SES) and racial/ethnic test score gaps using nationally representative data from the Early Childhood Longitudinal Study, Kindergarten Class of 2010–2011 (ECLS-K:2011), which includes more school-year and summer rounds than previous national studies. We further examine how inequality dynamics are influenced by the operationalization of inequality. Findings are consistent with a story in which schools initially accelerate relatively lower-achieving groups’ learning more so than higher-achieving groups; however, this school-year equalizing is not consistently maintained and sometimes reverses. When operationalizing inequality as changes in relative position, the reversal of school-year equalizing is more pronounced.
Quelles avenues vers une pédagogie postcoloniale et multimodale en contexte plurilingue ?
Authors: Vaudrin-Charette Julie , Fleuret Carole
Published: November 2016

Dans cette étude, nous examinons le rôle de l’enseignant dans la mise en œuvre d’une pédagogie postcoloniale des langues en contexte plurilingue. Nous relevons plus particulièrement les défis et possibilités de pratiques multimodales translinguistiques, notamment, à l’égard du rôle dynamique des langues autochtones et de l’éducation antiraciste. Pour ce faire, nous proposons un récit interprétatif d’observations réalisées dans le cadre de projets pédagogiques utilisant la radio comme média favorisant les passages entre cultures orales et écrites, et ce, dans des contextes plurilinguespluriethniques et autochtones. En posant un regard rétrospectif sur les pratiques, nous y repérons les affects de certaines représentations de l’interculturalité sur les interactions entre les enseignants et les élèves impliqués. En particulier, nous examinons les représentations autour du plurilinguisme en vue d’en illustrer les manifestations dans l’enseignement multimodal. Dans la foulée des recommandations de la Commission de vérité et réconciliation du Canada, nous examinons ainsi les liens entre un enseignement postcolonial des L2 à travers les pratiques multimodales et translinguistiques, et le rôle clé des langues autochtones dans la réconciliation pour l’ensemble des Canadiens.
L’utilisation des langues connues des apprenants en classe de français langue seconde
Authors: Dault Caroline , Collins Laura
Published: November 2016

Cette étude cherche à faire le point sur la pratique des enseignants de français langue seconde (L2) auprès d’adultes immigrants au Québec par rapport à l’utilisation des langues connues des apprenants. Le potentiel d’utilisation des diverses langues connues d’apprenants adultes dans un contexte multilingue reste sous-étudié. Nous nous sommes intéressées à la quantité et à la fonction de la langue maternelle (L1) en classe de L2, ainsi qu'au développement d’activités bilingues. Des observations des classes et des entrevues avec les enseignants ont permis de constater la forme, la fonction et les facteurs décisionnels sous-tendant les références interlangagières faites par ces enseignants. Le but ultime de la recherche est d’identifier le type de soutien pédagogique dont ils auraient besoin afin d’enrichir cet aspect de leur enseignement. Notre recherche démontre que les enseignants observés reconnaissent la valeur des références interlangagières et les utilisent principalement pour faire des traductions lexicales, des comparaisons phonétiques et des taquineries à l’endroit des apprenants. Par contre, leur pédagogique langagière, plutôt spontanée, est rarement incluse dans leur préparation. Nous amorçons une réflexion sur les approches pédagogiques envisageables pour que les enseignants fassent meilleur usage du répertoire langagier de leurs apprenants adultes multilingues afin de favoriser leur apprentissage d’une L2.
Le « Right to request flexible working » : un outil favorable aux employés proches aidants ?
Authors: Nogues Sarah , Tremblay Diane-Gabrielle
Published: November 2016

Au Canada, une consultation nationale a évoqué la pertinence d'instaurer un nouveau droit : les travailleurs pourraient demander à leur employeur un aménagement flexible de leur temps ou de leur lieu de travail, à l'image du « RTR flexible working » anglo-saxon. Notre article s'intéresse à l'effet de ce droit dans trois pays du Commonwealth où il a été instauré au cours des années 2000. Nous analysons sa pertinence en tant qu'instrument de politiques publiques visant un changement d'attitude managérial face aux accommodements que souhaiteraient des employés ayant des responsabilités familiales complexes, comme les proches aidants. Notre revue de la littérature montre que le RTR a eu un effet mitigé dans les milieux de travail, mais qu'il amène certains employeurs à offrir plus de mesures de flexibilité à leurs employés.
Managing User Delay with a Focus on Pedestrian Operations
Authors: Sobie Christopher , Smaglik Edward , Sharma Anuj , Kading Andrew , Kothuri Sirisha , Koonce Peter
Published: November 2016

Across the United States, walking trips are increasing. However, pedestrians still face significantly higher delays than motor vehicles at signalized intersections because of the traditional signal timing practices of prioritizing vehicular movements. This study explored methods to reduce pedestrian delay through the development of a pedestrian priority algorithm that selects an operational plan favorable to pedestrian service, provided a user-defined volume threshold has been met for the major street. This algorithm—along with several operational scenarios—was analyzed with Vissim with the use of software-in-the-loop simulation to determine the impact these strategies have on user delays. One of the operational scenarios examined was that of actuating a portion of the coordinated phase, or actuated–coordinated operation. Following a discussion on platoon dispersion and the application of it in the design of actuated–coordinated signal timing parameters, a sensitivity analysis was performed on vehicle extension timers to explore the impact that this coordinated movement parameter has on user delay. In the scenario analysis, it was shown that employing fully actuated (also known as free) operation—either with the designed algorithm or without—was an effective method of reducing pedestrian delay on the minor street while decreasing average intersection vehicle delay for the volumes used in the simulation. The vehicle extension sensitivity analysis showed that shortening the extension timer of an actuated–coordinated phase can reduce pedestrian delay on the minor street without increasing overall vehicle delay. This tool could be used by agencies during coordinated operation to prioritize pedestrians.
Implications of Cost Equity Consideration in Hazmat Network Design
Authors: Sun Longsheng , Karwan Mark H. , Kwon Changhyun
Published: November 2016

The hazardous materials (hazmat) network design problem (HNDP) is used to reduce the risk of transporting hazmat in the network by enforcing regulation policies. The goal of reducing risk can increase costs for hazmat carriers. Because the HNDP involves multiple parties, the cost increase for all carriers must be considered for implementation of regulations. Although upper bounds can be placed on the total increase, the actual cost increase for various origin–destination pairs can differ, resulting in unfairness among carriers. Thus, also considering cost equity in the HNDP is proposed. Additionally, because there are multiple solutions in current HNDP models and because of the possibility of unnecessarily closing road segments, a new objective considering the length of all the closed links is introduced. Computational experience is based on a real network, and results are shown for various cost consideration cases.
Deployment and Calibration Considerations for Large-Scale Regional Dynamic Traffic Assignment: Case Study for Sydney, Australia
Authors: Duell Melissa , Saxena Neeraj , Chand Sai , Amini Nima , Grzybowska Hanna , Waller S. Travis
Published: November 2016

Dynamic traffic assignment (DTA) has received increasing attention in recent years, and there are numerous examples of practical implementations. This work adds to the literature by describing the ongoing experience of building the first large-scale simulation-based DTA model in Australia. The input data for the model are summarized, and an in-depth discussion and an analysis of model output and the calibration process are presented. Current results put 80% of the 322 calibration points spread across the network within an acceptable bound of error, but the project found that alternative metrics of network performance also must be considered so that other aspects of model realism are not neglected. The described DTA model could be used for evaluating important policy decisions and infrastructural development in the context of the macro- and mesoscale network operation. Additionally, this project is a proof of concept for the Australian region and may provide insight to practitioners interested in emerging areas of transport planning and traffic modeling.
Path Finding in Stochastic Time Varying Networks with Spatial and Temporal Correlations for Heterogeneous Travelers
Authors: Zockaie Ali , Mahmassani Hani S. , Nie Yu
Published: November 2016

This paper studies the path finding problem in stochastic networks with known travel time distributions on each link of the network, in the presence of spatial and temporal travel time correlations. As a result of traffic dynamics and the decisions of network users, distributions with different characteristics can be observed for the link travel time at different time intervals. Considering correlations in a dynamic stochastic network and applying simulation-based realistic travel time distributions and correlations in the path finding problem in stochastic networks are the main contributions of this study. Two reliability-based optimal path finding problems were considered: the shortest path problem with on-time arrival probability and the minimum travel time budget path problem. For each problem, user heterogeneity can be considered in the developed approach, as users are allowed to have different preferences for travel time reliability. Solution algorithms for both problems were implemented and tested on a large-scale network in Chicago, Illinois, with networkwide link travel time distributions and correlations obtained from a traffic simulator. Numerical results demonstrate the impacts of correlations in a dynamic stochastic network on the optimal path travel time distribution. The developed approach can be used in the reliability-based user equilibrium problem to solve the main subproblem, the path finding problem, in dynamic stochastic networks.