bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety Integrity Analysis of Topside Piping and Vessels Installed on Offshore Platform
Authors: Thakur Subodh L.
Published: April 2017

Offshore processing platform involves large volumes of hydrocarbons at high pressure and therefore these systems represent high risk to personnel, environment and asset.

The main objectives of this article are: ➢Understand well the new methodology of safety integrity analysis for piping and vessels under fire scenario➢Provide information on what is acceptable and unacceptable rupture➢Understand the methodology for fire depressurization calculations, rupture calculations and mitigation methods to achieve safe design based on actual project experience➢Comprehend inputs required by technical safety

In earlier method, the pressurized segment exposed to fire is depressurized to 6.9 barg or 50% of design pressure (whichever is lower) within 15 minutes. 15 minutes depressurization time had been a generalized time with set of parameters and might be too long and could lead to unacceptable rupture in the piping and vessel in some cases due to excessive stress generated due to fire.

The new method is an iterative process of designing a depressurization system with major focus on evaluating actual stress in the piping and vessels installed on topside. The new method actually checks the rupture time for a segment under fire and assesses if rupture is acceptable or not based on acceptance criteria from technical safety.

This paper discusses the actual calculation methodology for piping and vessel integrity analysis based on actual project experience and importance of safety input for the analysis.

This method actually determines if rupture is acceptable or not. Unacceptable rupture shall demand for some mitigation actions/design improvements suggested below in order to ensure overall topside safety in case of fire. ➢Increase or utilize flare system capacity➢Increase pipe wall thickness➢Selection of material with higher UTS values at elevated temperatures.➢Provide Passive fire protection (PFP) that will allow pipe or vessel to sustain for longer fire duration. (Focus shall be on fast depressurization and other options)

It is very important to check the integrity of entire piping and process equipment's on the process platform which results in reducing the risk of missile effect due to rupture that can cause fatalities or serious injuries and consequently reduces the risk of damage to neighboring pressurized hydrocarbon system further reducing the risk that may lead to major economic losses and environmental disasters.

The new methodology described in this paper is used in international projects and when applied ensures a step forward towards achieving safe and cost effective design which in turn shall care for human life, asset and environment which is top priority.

This method is published in new edition of international codes and standards.
Enabling New Field Development Projects for a Digital Future
Authors: Praveen Sam Samraj , Airani Avinash
Published: April 2017

The use of new digital technologies have become an imperative for oil & gas companies seeking to improve the way they do business. In this paper, a framework is presented for the strategic use of digital technologies for new field development projects. The benefits of introducing the right technology at the right time is identified across the life of field. There are six areas during field development where a digital strategy must be executed: subsurface analysis & modeling, drilling & completions, production operations, reliability & maintenance, procurement & supply chain management, and general business operations.

A case-study based approach is used based on large projects executed in recent the past where digital technologies were planned and included during early field development. The paper identifies the areas and points during field development to include different digital technologies where the business impact is maximum and capital and operational expenditure is minimum. This was done by identifying technologies across two areas: (a) technologies to enable the execution of the mega-project; and (b) technologies that form part of the facilities for operations during life of field. It was found to be optimum to link the digital strategy during the engineering and design stages, and during the issue of contracts for commissioning facilities. This allowed the field to build a digital ecosystem which will help them prepare for a digital future by enabling readiness for advancements in the areas of analytics, global mobility, and automation. Oil and gas companies obtain a chance to gain competitive advantage through digital infrastructure and software applications when applied at the right time during field development.
Reducing the Appraisal Uncertainty with Advanced Wireline Formation Testing Technology: A Case Study from the Gulf of Thailand
Authors: Lozet A. , Platt C. J. , Chanthanaphalin U. , Gok I.M. , Ridho M. , Doogue J. , Khunaworawet T. , Watana K. , Daungkaew S. , Duangprasert T. , Lerdsuwankij T. , Paramatikul R. , Shi Z.
Published: April 2017

The paper discusses an application of advanced wireline Formation Testing (FT) technology on an appraisal stage in order to improve an understanding of reservoir characteristics and to assist a field development plan. The advanced FT technology includes a focused sampling probe, a new 3D radial probe, and a new fluid analyser. Further information on tool functionality, real-time data interpretation, and acquisition result is described.

Fit-for-purpose wireline FT modules were deployed. The focused sampling probe delivered quicker clean-up for downhole fluid extraction. The new fluid analyser with improved algorithm and more sensors measured fluid properties at downhole condition and also quantified a contamination level prior to capturing a fluid sample. The new 3D radial probe (Saturn Probe), which has the largest flowing area among probe family, enabled fluid pumping and sampling at low mobility zones. An Interval Pressure Transient Test (IPTT) to obtain permeability and skin was also conducted with this new probe. The data acquisition was closely monitored and discussed on real-time.

Several wells have been drilled and data was successfully acquired at reasonable operation time. The focused sampling probe, with its unique design, met an objective of providing fast clean-up during pumping formation oil. This was indicated by a sudden change on the fluid analyser's Gas-Oil Ratio (GOR) and other parameters when the probe was in "split the flow" mode and focused. The sudden change was then followed by stable measurements of acquired properties indicating practically minimum contamination level has been achieved. Besides quantifying a contamination level, the new fluid analyser was also able to validate the fluid type which was derived from the pressure points. In addition, its viscosity sensor helped to understand viscosity variation among reservoirs which could not be done with a conventional fluid analyser. The new 3D radial probe maintained pressure drawdown while pumping at low mobility zones. Hence, sand failure that potentially deteriorates tool performance could be avoided. It also had shorter operation time than a conventional packer while conducting IPTT due to less inflating volume and tool storage. The IPTT results showed radial flow regime which was further analysed for permeability and open-hole skin.

In an appraisal stage, data acquisition is critical for field development plan and final investment decision. It definitely requires robust and advanced technology that is able to deliver conclusive answer in challenging environment. A case explained here shows how the advanced technology revealed a hydrocarbon potential and confirmed reservoir continuity.
Holistic Approach in Managing Challenges of Mature Offshore Carbonate Gas Fields with High CO2 and H2S Content in Sarawak Gas Operations, MALAYSIA
Authors: Abdul Aziz M. F. , Mithani A. H.
Published: April 2017

Natural gas produced from underground reservoirs varies in its composition depending on the type, depth, and location of the underground deposit and the geology of the area. Natural gas is usually considered sour if the hydrogen sulphide (H2S) content exceed a certain threshold. And the term acid gas is usually used if it contains acidic gases e.g. carbon dioxide (CO2). Natural gas is called sweet gas when it is relatively free of H2S and CO2. The contaminants in natural gas needs to be treated or maintained within a certain limit as per the required pipeline quality for exports and sales. In Sarawak Gas Operations, the contaminants is being managed by means of integrated gas blending.

Field B is one of the deepest platform-type carbonate gas reservoir in Central Luconia Province, offshore Sarawak with highest level of contaminants i.e. 40 mol% of CO2 and 2800 ppm of H2S. Sampling at more frequent interval of twice a year is implemented to monitor the trending of the contaminants level which will give perception on the effective blending management and maximum gas recovery. The strategy to produce as much as sour gas first while ample sweet gas is available to achieve maximum overall gas recovery is well understood.

Observation on the trending for more than 10 years suggest that the level of contaminants is increasing by time and the field is souring. This finding is supported by the understanding of CO2 and H2S solubility in water which is higher as compared to hydrocarbon gases. The suspected mechanism for the reservoir souring is the changes in CO2 and H2S solubility in water with pressure change.

This paper summarises the main issue of increasing contaminants level and effort to maximise gas recovery from the souring reservoir and discusses on the results from contaminants level trending and example from analogue field.
Optimizing Drilling and Completions in Overpressured Malleswaram Field by Integrating Geomechanics with Advance Acoustics Measurements
Authors: Reddy S. S. , Anjaneyulu J. V. , Lal Abhay Kumar , Rao E. J. , Ramakrishna C. H. , Talreja Rahul , Bahuguna Somesh , Zacharia Joseph , Chatterjee Chandreyi , Basu Jayanta
Published: April 2017

ONGC is working on fast-track development of Malleswaram field in Krishna-Godavari (KG) basin. Proven gas reserves are located in the in the late Cretaceous Nandigama formation which is located at a considerable depth. Exploration wells were drilled and overpressure of up to 1.8g/cc were encountered in Raghavapuram and Nandigama formations. Many drilling challenges related to overpressure were faced, including losses, tight hole, and stuck pipe. Apart from causing non-productive time (NPT), these events also increase the risk associated with drilling and completion of a well. Since, the development phase has just begun and geomechanics study was not incorporated in the exploration phase, there is enough scope to optimize drilling and reduce NPT. This study was conducted with an objective to optimize drilling and completion activities by integrating advanced acoustic and geochemical data for geomechanics based solution. This paper is focused on the new insight developed on the cause of overpressure and characterizing it. A detail analysis on stress direction and its variation with depth and among wells is also presented. In addition, wellbore stability models are also discussed to understand the requirement of appropriate drilling mud weights and casing policy in order to improve wellbore integrity, mitigate drilling risks, and ensure future drilling success. Minimum horizontal stress, breakdown gradient and rock elastic properties generated under the study are also used to generate completion quality flags to aid in identification of stress barriers within reservoir sand units of Nandigama formation.
Seismic Curvature Attributes for Subtle Fault Detection in Tight Volcanic Reservoirs from Barmer Basin, India
Authors: Somasundaram Sreedurga , Bhat Sudeep , Das Amlan , Sharda Ruchika , Mund Bineet , Beohar Abhudai , Shankar Pranay
Published: April 2017

The current study area, Raageshwari Deep Gas field is situated in the southern part of onshore Barmer Basin in Rajasthan, India. The field contains a gas condensate reservoir with excellent gas quality within the dominantly volcanic formations (Basalt and Felsic) and overlying clastic Fatehgarh Formation. These are tight reservoirs and optimal field development necessitates reasonable characterization of faults and natural fractures thereby aiding well placement by targeting areas of enhanced permeability for better well performance.

The minor faults with throws significantly less than the duration of the seismic wavelet may not be detected in variance attribute data. However, reflection curvature is an attribute that also relates to structural deformation and shows greater spatial resolution. The detailed structural lineaments revealed through this analysis are indicative of sub-seismic faults and possible increased intensity of natural fractures. The maximum and minimum curvature data help to accentuate small scale reflection geometry changes and can be used to interpret minor faults. To discriminate stratigraphic features and identify fracture zones, careful calibration was done with production data, image logs and microseismic measurements from the wells.

The curvature attributes highlighted lineament distributions, interpreted to be small scale faults and subtle structural deformations associated with fractures. Lineaments of fault/fracture from curvature attributes were observed to correlate with interpretations from borehole image logs. Detected subtle faults were further validated with other measurements like microseismic and production data. These well calibrations provide confidence in the use of specialized seismic attributes for fracture characterization in the field. Results of this study will be used for optimal placement of infill wells for enhanced field productivity.
Mitigation of Work Control Challenges at Well Sites – Lessons from CBM Project
Authors: Pandey Baldev , Tomar Satendra
Published: April 2017

Control of work, a significant element of HSE management system at CBM, Shahdol, MP, is one of the major challenges in term of planning, communication, hazard identification, risk control and safe execution of work.

Challenges associated with Implementation of PTW system at 229 wells, spread in an area of 500 KM2, is quite different and unique in terms of planning, supervision, geographical spread, work efficiency and assurance methodology. Limitations of different permits (Confined space entry, hot work of high risk, and line break of high risk) for permit acceptors and receivers, parallel supervision at different well sites, transportation, and level of permit issuing authorities, warrant a scientific method to be adopted for optimization of numbers of permits, under responsibility of individuals.

In conventional E&P oil and gas fields, the numbers of wells are relatively lesser and in downstream, operation is more or less confined inside boundary walls. CBM activities are wide spread and with large number of wells/assets and pipelines, the activities are around inhabitations and closely interact with villagers, flora and fauna.

Effective control of work at such widely spread large number of assets in CBM is a herculean task and has to be supervised by a limited number of personnel.

It is appreciated that each individual has a physical, mental and psychological limitation in effectively and efficiently controlling work activities.

The detailed paper describes, the mathematical method for optimization of manpower resources for adequate control of job in terms of: What should be categories of permits based on risk involved in work?How many types and quantity of permits should be issued by one individual with variation of well sites (geographical spread)?How many types and quantity of permits should be received by an individual?How many types and quantity of permits can be supervised by area operators?What should be the level of issuing authority for different categories of permit (hot work-high risk, line break of high risk)?

The mathematical method for optimization will consider the following factors: Load factor based on risk involved in the work.Quantity of permits of different types that can be effectively supervised by an individual.Geographical distance between/among the work locations.Constraint factor of time of work (Work during natural light or during silent hours).

On the basis of above factors, a mathematical and logical formula has been developed which gives a quantitative figure called total permit load on an individual (permit issuer and acceptor). Base on capability of people, an upper mathematical limit of total permit load has been fixed. This mathematical formula provides ease in limiting the number of permit with risk involved and eventually will control the work at well sites.
Oil Spill Cleanup Using Aerographene
Authors: Wadhwani Rajat
Published: April 2017

Even in the 21st century, the oil industry is yet to overcome some major problems it faces related to oil spill cleanup. Oil spills can cause a multitude of problems for the environment which may even last for decades after the spill occurs. This paper discusses a novel approach that may provide a complete solution to combat oil spills. Conventional techniques are not adequate to solve the problems of massive oil spills. Graphene based aerogels or Aerographene have attracted widespread attention due to its excellent oleophilicity, hydrophobicity, reusability, high uptake rate of oil, high uptake capacity and recovery of oil. Although the application of graphene aerogel for an oil spill is still in its nascent stage, it offers great promise for the future. It is believed to have potential to replace present sorbents which are used commercially. This paper briefly outlines present oil spill cleanup techniques and problems associated with each technique. A major part of this paper will be on the evaluation of aerographene properties and how it overcomes major problems related to conventional techniques. Many properties of aerographene have been studied which makes aerographene stand a chance of replacing the present oil spill cleanup methods. This paper presents a novel idea by which cleaning up oil spills with the help of aerographene will become much simpler, easier, cheaper and will prevent the environment from degrading at a massive scale due to oil spills.
Successful Polymer Selection for CEOR: Brine Hardness and Mechanical Degradation Considerations
Authors: Divers Thomas , Gaillard Nicolas , Bataille Stéphane , Thomas Antoine , Favéro Cédrick
Published: April 2017

The selection of the right polymer chemistry in chemical enhanced oil recovery processes is key to successfully increase oil recovery. To start the screening process, it is necessary to look at minimum 3 parameters including brine composition, reservoir temperature and permeability. In addition to simple rheological tests, it is mandatory to evaluate the long-term and shear stabilities of the polymer candidates to ensure that viscosity is maintained over time at an economical concentration. In few cases, the polymer that yields the best results (especially viscosity yield) at an instant t is not always the best compromise when considering long-term stability or shear sensitivity. This paper aims at providing some guidelines to select the optimum chemistry for a wide range of field conditions.

The resistance of different acrylamide and ATBS-based polymers to salinity and shear is evaluated through viscosity measurements over a wide range of brine compositions. A parameter called R+, that reflects brine hardness, is introduced in this study. Brines considered are either with a constant Total Dissolved Salt (TDS) and varying R+ or different total salinities with a constant R+. This parameter is also used to compare shear resistance of the different polymers.

For all the polymers, there is a threshold value of R+ beyond which viscosity remains constant. Interestingly, this threshold is reached for lower value of R+ for polymers containing ATBS, a monomer also well-known to provide calcium tolerance. Increasing the amount of ATBS yields better tolerance to divalent cations and provides shear resistance. A minimum amount of sulfonated monomer is required to improve the overall stability in complex brines.

Some important guidelines are summarized in this paper that can help screen products among a wide range of reservoir conditions in order to find the most suitable candidate for a chemical enhanced oil recovery project.
Optimization of Fracturing Technique for Successful Exploitation of Tight Gas Reservoirs of Mandapeta Field
Authors: Medavarapu Kishorekumar , Das S. , Ch S. , Nainwal S. P.
Published: April 2017

Hydraulic fracturing is the proven stimulation technique to exploit hydrocarbon reserves trapped in tight gas Indian reservoirs especially in Mandapeta field of Southern India. Fracturing technique was customized to obtain designed fracture geometry which in turn resulted in very good post frac gas production rates. This paper deals in detail, the necessity of fracturing in Mandapeta field, meager production gains obtained in earlier fracturing treatments, challenges for fracturing, quality assurance and quality control of fracturing fluid, design and successful execution of fracturing technique.

Mandapeta field is located in Krishna Godavari Basin situated in Southern part of India. Customization of fracturing technique produced impressive gas production rates from Mandapeta field compared to earlier treatments. Poor geophysical properties of the reservoir, leak-off characteristics, completion constraints and high near wellbore frictions were some of the challenges observed during fracturing treatments. As the reservoir is having very low permeability, hybrid fracturing treatment with a pad comprising around 75 percent linear / slick gel followed by cross-linked slurry was designed and implemented successfully.

Gas production gains up to 37000m3/d in a single well was observed. 20/40 mesh high strength proppant was used in these treatments and maximum job size pumped was 151MT. Hybrid frac treatment was carried out in an exploratory location which resulted in impressive gas gain paving a way to further development of field. Pre-frac acid treatments improved the well bore connectivity to the reservoir thereby enabling the higher proppant concentrations to pump during the treatments. Chemical compositions addressed the surface tension and mobility concerns of the fracturing in gas reservoirs which resulted in faster cleanup and gas production. Recent successes of fracturing made a way forward to aggressive fracturing campaigns in this field.

Hydraulic fracturing treatments have to be customized to specific reservoir conditions so as to obtain success. Candidate selection, modeling designs using sensitivity analysis, suitable pre-frac treatments, lab studies for optimization of fracturing fluid, customized hybrid fracture treatments played vital role in successful execution of fracturing treatments in Mandapeta field of Southern India which can be applied to other tight gas reservoirs.
Treatment of a mixed wood preservative leachate by a hybrid constructed wetland and a willow planted filter
Authors: Lévesque S. , Demers E. , Brisson J. , Comeau Y.
Published: April 2017

The performance and removal mechanisms of a hybrid constructed wetland (HCW) followed by a willow planted filter (WPF) were evaluated for the treatment of a leachate contaminated by wood pole preservatives (pentachlorophenol (PCP) and chromated copper arsenate) to reach the storm sewer discharge limits. The HCW aimed to dechlorinate the PCP and polychlorodibenzo-p-dioxins/polychlorodibenzofuran (PCDD/F) and to remove metals by adsorption and precipitation. The HCW was efficient in removing PCP (>98.6%), oil, arsenic (99.4%), chromium (>99.2%), copper (>99.6%%) and iron (29%) to under their discharge limits, but it was unable to reach those of Mn and PCDD/F, with residual concentrations of 0.11 mg Mn/L and 0.32 pg TEQ/L. Iron and manganese could be removed but were subsequently released by the HCW due to low redox conditions. No dechlorination of PCDD/F was observed since its chlorination profile remained the same in the different sections of the HCW. Adsorption was the most probable removal mechanism of PCDD/F. The WPF was able to remove some residual contamination, but it released Mn at a gradually decreasing rate. Total evapotranspiration of the leachate by a larger fertilized WPF and the construction of an underground retention basin are proposed to prevent any discharge of PCDD/F traces in the environment.
Removing lead ions from aqueous solutions by the thiosemicarbazide grafted multi-walled carbon nanotubes
Authors: Zhou Ying , Yu Jingang , Jiang Xinyu
Published: April 2017

A novel multi-walled carbon nanotubes (MWCNTs) material functionalized with thiosemicarbazide was synthesized successfully and used to remove lead ions from aqueous solutions. The technologies of Fourier Transform Infrared Spectroscopy, scanning electron microscopy and thermal gravimetric analysis were used to characterize the structure and properties of thiosemicarbazide grafted MWCNTs. The adsorption conditions, such as pH, contact time and temperature, were investigated. The results showed pH affected the adsorption process greatly, and the adsorption process reached equilibrium within 60 min. The maximum adsorption capacity was 42.01 mg/g. The adsorption process fitted well with the pseudo-second-order kinetic model and the Langmuir model. The thermodynamic parameters indicated the adsorption process was endothermic and spontaneous in nature.
Comparison of extraction efficiency of various methods to extract L-DOPA from Mucuna pruriens (L.) DC.
Authors: Vora Ragni , Joshi* Ambika N. , Joshi Nitesh C.
Published: April 2017

Mucuna pruriens seeds are noted to be a natural source of L-DOPA and are also used as a substitute for the synthetic L-DOPA. In the present study; attempts are made to develop suitable method(s) for extraction of L-DOPA from the powdered seeds of Mucuna pruriens using different solvents and conditions. The Seed powder was subjected to 7 different extraction methods and Method 1 was subjected to various solvent concentrations. Some methods used de-fatting procedure, either the method was cold maceration or in high temperature. Soxhlet extraction was also used in one of the extraction methods. All the extracts were analyzed using RP-HPLC. Mobile Phase used was Water: Methanol: AcetoNitrile (100:60:40) (v/v) containing 0.2% Triethylamine, pH = 3.3 and monitored at 280 nm with variable wavelength UV detector. The extraction was best with Methanol Water mixture in a cold maceration technique and overall gives good extraction efficiency of 13.36 % L-DOPA and id the best method giving highest extraction efficiency. The De-fatting method was the 2nd best methods giving approximately 8.8% L-DOPA and Method 5 viz, heat reflux method gives 8.7% L-DOPA making it the 3rd best method. There are not many studies done for optimization of extraction technique for L-DOPA despite an extensive work is reported for isolation, identification and pharmacological activities of L-DOPA from various plant sources. Keeping this in view, present investigation was done to study the extraction efficiency of various extraction methods of L-DOPA content in seed extracts of Mucuna pruriens and compare it.
Recent Trends in Wastewater Flow and Pollutant Load Resulting from Urbanization in Shanghai
Authors: Liu Chen , Huang Tao
Published: April 2017

To better control water pollution and to manage water resources, we used input‐output analysis to examine structural changes in wastewater flows and pollutant loads following changes in socioeconomic activities in Shanghai. We found that the industrial structure has changed considerably and that total direct emission loads exhibited a decreasing trend between 1997 and 2007. Emission loads from secondary industries, especially from paper manufacturing, have decreased. However, wastewater from primary industries remained constant while wastewater from tertiary industries and domestic sources increased, acting as the largest sources of emission loads since 2002. Wastewater and pollutant loads from household consumption, including indirect sources from food manufacturing, clothing, and transportation, had an especially large influence on emission loads in 2007. These emissions were primarily generated through primary industries and food manufacturing sectors. With continued urbanization, wastewater and pollutants generated by household consumption should be factored into the control of water pollution in Shanghai.
Assessing UV Inactivation of Adenovirus 41 Using Integrated Cell Culture Real‐Time qPCR/RT‐qPCR
Authors: Ding Ning , Craik Stephen A. , Pang Xiaoli , Lee Bonita , Neumann Norman F.
Published: April 2017

Enteric adenoviruses are among most UV‐resistant viruses in water. Cytopathic effects (CPE)‐based cell culture TCID50 assay as a conventional virus assessment approach has major drawbacks for enteric adenovirus since it is selective on cell lines and takes longer time to show CPE. Integrated cell culture real‐time quantitative PCR (ICC‐qPCR) and reverse transcriptase (RT)‐qPCR were applied in this study, in comparison with TCID50, to assess UV inactivation of adenovirus type 41 (Ad41) in water. Adenovirus type 41 was exposed to UV doses of 40, 80, 160, and 320 mJ/cm2 using a collimated beam apparatus. There was no significant difference of inactivation at conducted UV doses between measurements using TCID50 assay and ICC‐RT‐qPCR. Both assays fitted the Chick‐Watson model at 95% confidence level. The inactivation measured by ICC‐qPCR did not fit the Chick‐Watson model. In summary, ICC‐RT‐qPCR is the most appropriate alternate to CPE‐based assay for assessing UV inactivation of enteric adenoviruses.
Heavy Metal Ions Uptake by AlPO‐5 and SAPO‐5 Nanoparticles: An Experimental and Modeling Study
Authors: Biriaei Rouholamin , Halladj Rouein , Askari Sima
Published: April 2017

Synthesis of AlPO‐5 and SAPO‐5 nanoparticles was followed by applying hydrothermal method to use them as adsorbents in the removal of Fe3+, Pb2+, and Cd2+ions.The synthesized products were characterized using powder X‐ray diffraction, scanning electron microscope (SEM), FTIR and BET analysis. The adsorption isotherms and kinetics including Langmuir, Freundlich, pseudo‐first order, pseudo‐second order and intraparticle diffusion models have been employed. The experimental adsorption equilibrium and kinetic data nearly followed the Langmuir isotherm and pseudo‐second order kinetic model, respectively. It was found that the existence of the bridging hydroxyl group in the SAPO‐5 structure causes chemisorption of Fe3+, Pb2+, and Cd2+ions on SAPO‐5 which have greatly improved the performance of this adsorbent against its low external surface area. Using AlPO‐5 and SAPO‐5 as novel adsorbents in heavy metal adsorption for the first time indicated the great potential of these adsorbents in removal of heavy metal ions from water.
Characterization and Performance of Hollow Silica for Adsorption of Amoxicillin in Aqueous Solutions
Authors: Ou Hongxiang , Chen Qunhui , Chen Guanghao , Wang Lili , Xu Yanzhao , Ma Jianfeng , Wang Liping
Published: April 2017

Two kinds of hollow silica materials, namely H‐SiS1 and H‐SiS2, were synthesized using the yeast template method and the Pickering emulsion polymerization method, respectively. The adsorbents were synthesized to adsorb amoxicillin (AMX) from an aqueous environment. Characterization results indicated that hollow silica adsorbents exhibited excellent thermal stability even at temperatures above 700 °C. Several batches of static adsorption experiments were prepared to analyze the adsorption performance on AMX. Isotherm data on different adsorbents fitted well with the Langmuir model (from 15 °C to 35 °C), indicating a monolayer molecular adsorption mechanism for AMX. The maximum adsorption capacities of H‐SiS1 and H‐SiS2 were 8.40 and 3.46 mg/g at 35 °C, respectively. The adsorption kinetics was described well by the pseudo‐second‐order model, which indicated that chemical interactions were primarily responsible for AMX adsorption and could be the rate‐limiting step during adsorption. These results suggested that H‐SiS1 could be significantly useful as adsorbents for removal of AMX residuals from aqueous solution.
Utilización de especies nativas del “bosque seco” para la recuperación del paisaje en el proceso de cierre del botadero a cielo abierto del distrito las Lomas – Piura
Authors: Montoro Negrón Bárbara Elizabeth
Published: April 2017

La investigación se refiere a la fragmentación del paisaje del distrito de Las Lomas en Piura, afectado por la existencia de un botadero a cielo abierto. El estudio se focaliza en la posible restauración del paisaje durante el proceso de clausura. Para lo cual se estudiaron las especies vegetales nativas del bosque seco piurano seleccionando las más resistentes y útiles en el proceso de recuperación, las mismas que fueron colocadas paisajísticamente sobre la cobertura final. Este proceso denominado fito-remediación ayudará a que las raíces de árboles y arbustos estabilicen el área clausurada, degraden los residuos y absorban los lixiviados. Una correcta colocación y posterior crecimiento de la vegetación recuperará el paisaje, ayudará al retorno de la fauna desplazada y permitirá que se acelere este proceso regenerador para el bienestar de la población vecina.
Análisis dinámico de estructuras de hormigón armado
Authors: P. Tamayo Jorge L. , Awruch Armando M. , Morsch Inácio B.
Published: April 2017

El objetivo de este trabajo es presentar un modelo numérico confiable usando el método de los elementos finitos (MEF) para el análisis dinámico de estructuras de concreto reforzado. Con este propósito, un programa de cómputo basado en la teoría de elasto-plasticidad con sensibilidad a la velocidad de deformación es desarrollado usando elementos finitos tridimensionales. El procedimiento de Newmark es adoptado para la integración en el tiempo del sistema no linear de ecuaciones. Además, se supone que el acero de refuerzo está perfectamente distribuido e adherido al concreto, siendo representado por elementos finitos de membrana. Dos ejemplos son solucionados con el presente modelo numérico y los resultados obtenidos son comparados con los resultados de otros autores. Para todos los casos, la trayectoria de falla, la carga de colapso y el mecanismo de falla son reproducidos con suficiente precisión.
Simulación numérica del esfuerzo de flexión a cargas variables en engranajes plásticos
Authors: Moya Rodríguez Jorge Laureano , Vílchez Vílchez Tito Roberto
Published: April 2017

Los ensayos en bancos de prueba permiten simular las condiciones del contacto real que se generan entre los dientes de un engranaje, pero son costosos y de limitada utilidad por su precisión que depende de las condiciones del equipo y el material. El objetivo fundamental de esta investigación es desarrollar un procedimiento que simule el esfuerzo de flexión en dientes de engranajes de plástico a través del método de simulación numérica y realizar el estudio de los principales parámetros que afectan el desempeño de los engranajes plásticos como son: torque, potencia y esfuerzos de estos engranajes cuando se encuentren en régimen de operación, haciendo una comparación con los aceros fundidos. Los resultados de esta investigación satisfacen los objetivos generales y específicos del estudio, los que contribuirán en la mejora de la tecnología de la industria peruana.
Diseño y evaluación experimental de un nuevo dispositivo mecánico para el control de potencia de pequeños aerogeneradores en régimen de sobrevelocidad del viento
Authors: Gonzáles Chávez Salome , Urcuhuaranga Jesús William
Published: April 2017

En este trabajo se realiza el diseño y pruebas de un nuevo dispositivo mecánico acoplado a la Cola-Veleta de un pequeño aerogenerador, tal que autorregula y controla la potencia instantánea de generación durante las sobrevelocidades de viento. La faja costera rural y zonas altoandinas del Perú, poseen gran potencial eólico, pero contrariamente se tienen nulos servicios eléctricos. En este escenario, la dotación de electricidad mediante microaerogeneradores constituye una alternativa estratégica. Una desventaja de los vientos característicos de las zonas de influencia es su alta variación de velocidades, cuyo efecto adverso en el aerogenerador es la destrucción prematura del bobinado del generador de imanes permanentes y rotura de palas. Las pruebas de regulación y control de potencia de aerogeneración se realizaron en el Túnel de Viento del Laboratorio de Energía de la Facultad de Ingeniería Mecánica de la UNI. Los resultados se dan en las curvas de potencia del conjunto aerogenerador de ensayo, donde se demuestra el control del crecimiento de la potencia generada, en el rango de velocidades de viento superiores a la condición nominal de diseño del aerogenerador. También se demuestra la confiabilidad del mecanismo cuando se somete a velocidades extremas de viento hasta alcanzar el bloqueo del aerogenerador, así como la inmediata recuperación continua de operación a medida que la velocidad de viento disminuye hacia condiciones nominales de trabajo.
A Population-Based Analysis of Quality Indicators in CKD
Authors: Manns Liam , Scott-Douglas Nairne , Tonelli Marcello , Weaver Robert , Tam-Tham Helen , Chong Christy , Hemmelgarn Brenda
Published: April 2017

Background and objectives

Awareness of CKD remains low in comparison with other chronic diseases, such as diabetes, leading to low use of preventive medications and appropriate testing. The objective of this study was to evaluate the quality of care provided to people with and at risk of CKD.

Design, setting, participants, & measurements

We conducted a population-based analysis of all Albertans with eGFR=15–59 ml/min per 1.73 m2 between April 1, 2011 and March 31, 2012 as well as patients with diabetes (as of March 31, 2012). We assessed multiple quality indicators in people with eGFR=15–59 ml/min per 1.73 m2, including appropriate risk stratification with albuminuria testing and preventive medication use and screened people with diabetes using urine albumin-to-creatinine ratio and serum creatinine measurements.

Results

Among 96,480 adults with eGFR=15–59 ml/min per 1.73 m2, we found that 17.0% of those without diabetes were appropriately risk stratified with a measure of albuminuria compared with 64.2% of those with diabetes (P<0.001). Of those with eGFR=15–59 ml/min per 1.73 m2 and moderate or severe albuminuria, 63.2% of those without diabetes received an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker compared with 82.1% in those with diabetes (P<0.001). Statin use was also significantly lower in patients with eGFR=15–59 ml/min per 1.73 m2 without diabetes (39.2%) compared with those with diabetes (64.6%; P<0.001). Among 235,649 adults with diabetes, only 41.8% received a urine albumin-to-creatinine ratio and 73.2% received a serum creatinine measurement over 1 year.

Conclusions

We identified large gaps in care, especially in those with CKD but no diabetes. The largest gap was in the prescription of guideline-concordant medication in those with CKD as well as appropriate screening for albuminuria in those with diabetes. Our work illustrates the importance of measuring health system performance as the first step in a quality improvement process to improve care and outcomes in CKD.
Motivations and Benefits of Student Volunteering: Comparing Regular, Occasional, and Non-Volunteers in Five Countries
Authors: Smith Karen , Holmes Kirsten , Haski-Leventhal Debbie , Cnaan Ram A , Handy Femida , Brudney Jeffrey L
Published: April 2017

Programmes targeting student volunteering and service learning are part of encouraging civic behaviour amongst young people. This article reports on a large scale international survey comparing volunteering amongst tertiary students at universities in Australia, Canada, New Zealand, the United Kingdom, and the United States of America. The data revealed high rates of student volunteering and the popularity of occasional or episodic volunteering. There were strong commonalities in student volunteering behaviour, motivations and benefits across the five Western predominately English-speaking countries. Altruism and self-orientated career motivations and benefits were most important to students; however volunteering and non-volunteering students differed in the relative value they attached to volunteering for CV-enhancement and social factors.
Cooperative Development Gap in Québec and Saskatchewan 1980 to 2010: A Tale of Two Movements
Authors: Diamantopoulos Mitch
Published: April 2017

ABSTRACTThis study uses Gramscian hegemony theory and the social movement approach to cooperative development to investigate the cooperative development gap that opened up between the provinces of Québec and Saskatchewan from 1980 to 2010. First, provincial sector growth is compared across several indices to establish this gap’s empirical scope and scale. Second, historical research and fieldwork findings are used to illuminate the gap’s origins and its historical significance. The article concludes that the development gap has been largely driven by bloc formation and dissolution—the historic erosion of Saskatchewan’s traditional, agrarian-cooperative bloc and the renewal and expansion of Québec’s social economy bloc.RÉSUMÉCette étude utilise la théorie de l’hégémonie de Gramsci et la méthode par le mouvement social pour le développement des coopératives afin d’enquêter sur l’écart qui s’est creusé entre les provinces du Québec et de la Saskatchewan de 1980 à 2010 en ce qui a trait au développement des coopératives. Tout d’abord, pour établir la portée et l’échelle empiriques de cet écart, cette étude compare la croissance de ce secteur entre les deux provinces. Ensuite, l’origine de l’écart et sa signification historique sont mis en lumière grâce aux recherches historiques et aux conclusions tirées de l’étude sur le terrain. Finalement, il est conclut dans cet article que l’écart de développement a été majoritairement créé par la formation et la dissolution de blocs – l’érosion par le temps du bloc coopératif agraire traditionnel de la Saskatchewan ainsi que le renouveau et l’expansion du bloc d’économie sociale du Québec.
Entreprenariat social et entreprenariat collectif : synthèse et constats
Authors: Fontan Jean-Marc
Published: April 2017

RÉSUMÉL’article présente les résultats d’une recherche portant sur les notions d’entrepreneur social et d’entrepreneur collectif. Après avoir défini le concept d’entrepreneur, nous voyons comment les qualitatifs « social » et « collectif » transforment l’idée d’entreprendre en un projet plus intégré où les objectifs sociaux, politiques et économiques sont « harmonieusement » agencés. La recherche repose essentiellement sur la réalisation d’une revue de littérature de textes clés produits en langue française et anglaise en Amérique du Nord et en Europe. L’analyse des données recueillies nous permet de présenter des critères simples pour proposer une définition de ces notions qui devrait rendre compte de la réalité des pratiques rencontrées sur le terrain et des contributions théoriques et critiques faites par les auteurs et travaux consultés. Elle permet aussi de présenter une dizaine de constats qui illustrent tant les points de convergence que les divergences observées entre les types d’entreprenariat étudiés.ABSTRACTThis article presents the results of a study bearing on the notions of social entrepreneur and collectiveentrepreneur. After defining the concept of entrepreneur, I look at how the adjectives “social” and “collective” transform the project of being an entrepreneur into a more integrated one where the social, political and economic objectives are “harmoniously” organized. The study is essentially based on a literature review of key English- and French-language texts written in North America and in Europe. The analysis of the collected data allows me to present simple criteria for proposing a definition of these notions that should take into account both the reality of the practices encountered in the field and the theoretical and critical contributions made by the authors and the texts that I consulted. It also enables me to present ten observations that illustrate both the points of convergence and divergence between the types of entrepreneurship that I studied.
Understanding the Rural Tilt among Financial Co-operatives in Canada
Authors: Mook Laurie , Hann Jennifer , Quarter Jack
Published: April 2017

ABSTRACTThis mixed methods study examines whether the rural/urban distribution of credit union/caisse populaire branches differs significantly from the general urban/rural demographic pattern in Canada. It also explores whether their distribution is different from that of banks, looking at the cases of Québec and Atlantic Canada. The study finds a rural tilt among financial cooperatives in Canada, and seven key informants present their views on the results. Their responses are categorized in two main themes: why financial cooperatives are overrepresented in rural and small town areas, and why they are under-represented in urban ones. A discussion follows, and directions for further study are provided.RÉSUMÉCette étude utilisant des méthodes combinées examine si la distribution des succursales de coopératives d’épargne et de crédit / caisses populaires en milieu rural et urbain diffère de façon importante de la tendance démographique générale des milieux urbains et ruraux au Canada. Elle aborde aussi la question de savoir si leur distribution est différente de celle des banques en observant le cas du Québec et du Canada atlantique. L’étude révèle une tendance rurale chez les coopératives financières du Canada, et sept répondants clés donnent leur opinion sur les résultats. Les réponses des intervenants sont divisées en deux thèmes principaux : pourquoi les coopératives sont surreprésentées dans les milieux ruraux et les petites villes et pourquoi elles sont sous-représentées dans les milieux urbains. Un débat s’ensuit, et des lignes directrices sont fournies aux fins d’une étude plus approfondie.
High Ideals and Noble Intentions: Voluntary Sector-Government Relations in Canada
Authors: Procknow Greg
Published: April 2017

Peter R. Elson ﻿
Social Movement Structures in Relation to Goals and Forms of Action: An Exploratory Model
Authors: Willems Jurgen , Jegers Marc
Published: April 2017

ABSTRACT This article describes a theoretical taxonomy of the structural features of social movements. We begin by using two classification criteria to analyze the types of relations that characterize the structure of social movements. From there, we look at how differences in structure relate to different goals and forms of action. We then derive a four-fold classification system based on formalization and hierarchy of relationships. For each classification we provide case descriptions of social movements (or parts thereof) using literature on how different movement structures support different types of goals and forms of action. Furthermore, we discuss the dynamics of social movements (or parts thereof) and how their classification may evolve. By doing so, we illustrate how changes in structure, goals, and forms of action mutually influence each other. RÉSUMÉ Cet article dresse une taxonomie théorique des caractéristiques structurelles des mouvements sociaux. Nous utilisons d’abord deux critères de classification pour analyser les types de relation propres à la structure des mouvements sociaux. Par la suite, nous observons comment des différences de structure coïncident avec des buts et des formes d’action différents. Nous développons ensuite un système de classification quadruple fondé sur la formalisation et l’hiérarchisation des relations. Pour chacune des classifications, nous fournissons des descriptions de cas de mouvements sociaux (ou de parties de ceux-ci) en recourant à des écrits sur la manière dont des structures de mouvement différentes entraînent des buts et des formes d’action différents. En outre, nous discutons des dynamiques des mouvements sociaux (ou de parties de ceux-ci) et comment leur classification pourrait évoluer. Par ce moyen, nous illustrons comment des changements de structure, de but et de forme d’action s’influencent réciproquement.