bluuebunny/crossref_metadata_2025 huggingface dataset:
Maximizing the Economic Value of Intelligent Completions through Effective Use of Surveillance
Authors: Gohari Kousha , Gonzalez Luis E , Hosseini Naser , Kazi Saif , Khateeb Ashraf , Awid Abdurrezagh , Jutila Heikki , Kshirsagar Atul
Published: October 2017

Intelligent completions or Smart Well Completions have gained traction in recent years as they provide better control for reservoir management. Simply, intelligent completions consist of the two components, Flow Control and Permanent Downhole Monitoring Systems (PDHMS). While the value of flow control systems has been heavily documented, less has been published regarding the optimization of flow control systems in a proactive manner by more effective utilization of data obtained from the monitoring systems.

This paper simply outlines how monitoring data can be used to optimize flow control systems. By better utilization of the monitoring data active flow control valves are able to be functioned to ensure that the well is operating under optimum conditions. Furthermore monitoring data can be used to validate completion designs while allowing engineers to identify if interventions are required and if so which sections require the intervention.
New Progress of the Offshore Thermal Recovery Technologies in Bohai Bay, China
Authors: Liu Yigang , Han Xiaodong , Zou Jian , Wang Qiuxia , Wang Hongyu , Liu Hao , Jiang Zhaobiao
Published: October 2017

There is abundant heavy oil resource in Bohai Oilfield and good development performance of the pilot area has been acquired by using thermal recovery technology. In recent years, a series of researches and field pilots have been conducted and great progress has been achieved on several aspects.

For HSE, a high-temperature safety control system was developed, which consists of downhole safety valve, cable packer, vent valve, and heat compensator. The overall temperature and pressure resistance value could reach as high as 350°C and 21MPa, respectively. With the development of the high temperature safety control tools and the progress of the high temperature electric submersible pump lifting technique, the integrated tubing with functions of both steam injection and oil production was designed and developed which could be applied for the 250°C cyclic steam and flue gas stimulation. The application of this integrated tubing could greatly decrease production cost by avoiding unwanted well workover.

For treatment of gas channeling, the comprehensive treatment technology which consists of the injection parameters optimization, multi-well cyclic stimulation, and the chemical blocking method was formed based on the experiments, reservoir simulation, and field pilots. Besides, 50t/h steam generator that is suitable for offshore thermal recovery was designed and developed, and the related matching technologies such as nitrogen generation, sea water desalination, artificial lifting, viscosity reduction in wellbore were all studied. The design of the overall development program produced by huff and puff for an unexploited oilfield are carrying out.

Great progress and breakthrough of the offshore thermal recovery technologies in Bohai Oilfield have been achieved in recent years, which will provide powerful technical support for the high efficiency development of the heavy oil resource in Bohai Bay.
A New Practical Approach to Building Tight Reservoir Development Integration Data Model in China
Authors: Liu He , Yan Jianwen , Yao Zixiu , Zhao Zhe
Published: October 2017

The integration data model between geology and engineering is proposed to tackle the key issue of improving average well production by making development plans in a reverse manner and conducting dynamic researches that have foresight, target ability, forecast ability, guidability, pragmaticality, and time effectiveness, accompanied by their instant applications. The model takes 3D geologic models as the core and the unified investigations of geology and reservoir as the foundation, with the complicated relationships and operation difficulties at all development phases considered. All sections are logically combined with each other and are scheduled in a global way where the integration between geology and engineering is taken as the guide, reservoir stimulation as the focus, maximizing production as the target, and factory-like operation as the measure. The fundamental geological and engineering factors that affect the productivity is analyzed, and the adaptivities of well completion and fracturing techniques are systematically assessed with in-depth investigations into the reservoir physical properties, geomechanics, fracture features, well layout and drilling, reservoir stimulation, and liquid discharge for production, et al. Assisted by effective organization, management, and operation practice, rapid accumulation and enrichment of operation experiences and multi-disciplined knowledge covering well drilling and cementation, fracturing, and production and its test production are achieved. Economic development is fulfilled in tight reservoirs by hierarchically and dynamically optimizing engineering efficiency and development profit that arise from continually adjusting and perfecting technical projects related to well drilling, fracturing, and so on.
Design of Jumper Lines to Unlock Potential of Wells - A Success Story
Authors: Siboro M. , Widitya A. , Prabowo A.
Published: October 2017

Total E&P Indonesie (TEPI) has identified several bottlenecks on surface facilities in order to produce higher amount of gas. As TEPI is operating mature fields, existing facilities that were originally designed with higher operating pressure could not accommodate the same amount of gas when operated with lower pressure; Hence the need to perform debottlenecking arises. Most bottlenecks are identified on gathering facilities incoming piping line, designed to connect wells on swamp areas of Mahakam. Previously, base case of production debottlenecking (modification to increase production) requires major effort to completely dismantle existing incoming piping & replacing them with a bigger size piping. This concept will consume a significant amount of production shortfall coming from platform shutdown, equally time consuming procurement lead time and significant material cost. Since 2015, installation of jumper lines has become the base case of production debottlenecking to unlock potential of wells. This modest but robust concept is based on the premise to utilize existing idle flow lines as means to share the flow on the supposedly saturated incoming gathering line. Deterministically, the maximum allowed flow to be handled by the jumper line is determined based on the Flow Induced Vibration (FIV) and also Erosional Velocity criteria. While, some probabilistic approaches in terms of pipe material Likelihood of Failure (LoF) and backpressure analysis has been also considered in the review. Throughout process engineering review & safety due diligence, the main safety concern is the probability of imbalance flow during early operation of the jumper line (possibility of all flow routed to only one flowline and compromising the flowline limitation threshold). However, this potential shortcoming has been managed smoothly by the site operation team (by specific procedure to cover the operation). In terms of shortfall consumption, installation of jumper line option is much appreciated as the shut down for the tie in is limited to the flowline (instead of to the whole platform). Up to end of 2016, there had been 7 jumper lines installed and in operation, giving an additional production of averagely 9 MMscfd per lines, with a cost of ranging between 150,000 200,000 USD. Installation of jumper line has been proven as a reliable debottlenecking means with the highest regard of safety (TEPI core value). This concept is a proof that knowledge of existing installation is of paramount element to optimize the installation. With the very difficult economic environment, desperate times called for desperate measure. It is an excellent demonstration that saving could work both ways: to reduce the expenditure while at the same time gaining more production.
Application of Temperature Surveys to Enhance and Optimize the Limited Entry Hydraulic Fracturing Treatment Design and Placement
Authors: Sidharth P. , Tiwari S. , Ranjan V. , Anand S. , Goyal R. , Vijayvargia U. , Sharma A. , Johri N. , Yadav K. Janardan , Deb D. , Tibbles R. , Pathak S.
Published: October 2017

Objectives/Scope

Raageshwari Deep Gas field located in southern Barmer Basin, in the state of Rajasthan (India), consists of a laminated reservoir where conventional fracturing treatments with a single set of perforations are not economical. In order to improve the project economics, limited entry treatment design (Lagrone, 1963) selected for fracturing. The effectiveness of fluid diversion during limited entry fracture treatment in a laminated reservoir was validated using post injection temperature surveys.

Methods, Procedures, Process

The Limited entry design relies on the pressure drop across the perforations to balance the flow between the various perforation clusters. The treatment design was based on achieving a minimum of 700 psi of perforation friction for adequate diversion between the zones. The perforation friction and number of active perforations was determined using Step Rate/Step Down Tests (SRT/SDT). Post injection temperature surveys were used to confirm fluid entry into the various perforation clusters.

Results, Observations, Conclusions

The following process was applied to more than 90 fracture stages in 15 wells. The fracturing treatments were modeled using log derived mechanical properties and stress contrasts. Diversion into all the clusters was insured by distributing the available perforations based on the predicted fracturing pressure for each zone. Post injection temperature surveys were used to validate the fracturing models. While somewhat qualitative, the post injection surveys did provide valuable insite in some cases, the fracturing simulator predicted fracture growth out of the desired stage area. The post injection temperature survey helped to validate predictions of:

In some cases, post SRT temperature surveys helped justify decisions addition of holes to minimize perforation friction or addition of extra cluster(s) to maximize pay coverage.

Novel/Additive Information

While the use of temperature surveys to estimate fracture height is not new, we believe that this is the most extensive use of temperature surveys in a medium size project incorporating limited entry.
Techno-Economic Evaluation of Carbon Capture Storage Ready for Coal-Based Power Generation in Indonesia
Authors: Sugihardjo Usman , Sismartono Danang , Lubad Aziz M. , Hedriana Oki , Sugiyanto Arief
Published: October 2017

To meet the rapidly growing demand and to provide secure base load power supply, Indonesia's power sector is seeing a growing share of coal in its generation mix. However, increased coal-based generation contributes to increased CO2 emissions. This study aims to define and evaluate the conditions under which coal-based generation could be deemed as carbon capture and storage ready. It considers the technical and economic implications of CO2 capture and storage for two candidate coal power plants in South Sumatera and West Java. A carbon capture storage of a couple of scenarios are evaluated for each power plant based on separation of 90%, 45% and 22.5% of CO2 from the power plant flue gas with an amine scrubbing process, supported by flue gas cleaning processes, and liquefaction of the captured CO2 for transportation to geological storage locations. The carbon capture storage operation would also run for 20 years, 15 years and 10 years, while the power plant design life is 25 years. The potential to sell captured CO2 for enhanced oil recovery in South Sumatera is also assessed. Results of this study will help Indonesia to identify a way to reduce CO2 emissions from the coal-based power sector in the long run and will contribute significantly to putting the country's energy sector on a sustainable development path.
Indonesian Milestone in Production-Sharing Contract in Perspective of Government Take, Contractor Take, Cost Recovery and Production Target
Authors: Daniel Harimurti
Published: October 2017

Recently in Indonesia are experiencing various of revision and improvement in the regulations, related with the oil and gas industry activity, this kind of situation certainly will impact to the investment atmosphere in the Indonesia oil and gas upstream. International Oil Company and the Government has different point of view related to contracts in PSC. Several analysis or study has been done by institutions and individuals through articles or papers on the comparing for the terms and conditions of a contract with different country. But not many have discussed particularly about the general change of PSC in Indonesia.

This study will compare the historical of Indonesia PSC generations from generation I (1966) until the recent fiscal terms of gross split (2017). Those terms will be compare by using a hypothetical block to modelize the PSC block in Indonesia, which consist of several field. Some assumption also will be used for each field with different peak rate, development scenario, capital variable cost ranges, operation variable cost ranges, which those range data are expected still within the range of most likely consist parameter for PSC block in Indonesia.

This study purpose is to analyze if the Gross Split mechanism is more attractive or equal the PSC Cost Recovery. The result of this study shown that the gross split PSC refer to the Minister of Energy and Mineral Resources no.52 year 2017 is still attractive to the investor from the contractor take perspective. Eventough with the PSC Cost Recovery mechanism the contractor feels more secure for the cost that can be recover from the oil and gas that produces, as part of cost recovery. If the application of Gross Split is clear enough from the regulation, tax, assets rent and others, surely this mechanism can attract more investor to do exploration and development in Indonesia.

Regardless of the political and strategic interests of the Indonesia government or the National Oil Company, the results of this study hopefully can be useful for the professional, educational institution, and government for lesson and learn. How the fiscal term can be impact to the government take, contractor take, cost recovery also the production target related with reserves replacement.
A Performance Comparison between Two Novel Multistage Completion Methods in Tight Gas Sandstone Formation from Ordos Basin
Authors: Hao Geng , Tengze Ge , Chuanqing Liu , Xiaojie Yu , Liu Yuan , Wang Weikan , Liu Hai , Niu Li , Yang Baibing , Liu Xiaoli
Published: October 2017

Efficiency, cost, and corresponding well performance are the primary concerns of multistage completions for tight oil and gas development. With the vision of continuous improvement in the industry, novel multistage completion methods such as dissolvable ball seat and sliding sleeve systems become significant technical progressions for multistage completions. Technology comparisons in a specific field help to identify the preferred solution for its reservoir and well construction features, so as to set guidelines for future improvement and planning in similar applications.

Daji field is in the southeastern part of the Ordos basin. Comparing with the central part of the basin, the main formation here has relatively poor reservoir qualities, so it is expected that horizontal wells with multistage completion may help to unlock the production potential via better reservoir contact. Two different completion systems were installed in adjacent wells, one with a dissolvable plug-and-perf system, and the other with a coiled tubing activated sliding sleeve system. The purpose of the project is to evaluate the novel technologies and identify preferred options for future horizontal wells.

Although adjacent, the two candidate wells perform differently during the execution phases. Continuous multistage pumping operations were conducted for both wells, while on-site execution found the dissolvable plug-and-perf system demonstrated much higher efficiency.

Both completion methods are relatively new as multistage stimulation applications. The direct comparison in this field has helped to identify the pros and cons of each system and set up the preference for future development.
Eliminating Underground Blow Out Risk with Constant Bottom Hole Pressure CBHP MPD Technique in Kalimantan Offshore, Indonesia
Authors: Zein Joydi , Iskandar Yoshua , Fadlin Fadlin , Usmar Ray
Published: October 2017

We often face a higher level of difficulty when using conventional methods to drill through a formation with a narrow pressure window. Even slight changes to bottom hole pressure can lead to unwanted non-productive time (NPT) in the process of securing the well, such as handling a loss and/or kick in the wellbore, or even at times, an underground blowout.

Maintaining Constant Bottom Hole Pressure (CBHP) is one of Weatherford's Managed Pressure Drilling (MPD) technologies used to drill safely by keeping the well overbalanced yet below fracture gradient. This is done by applying Surface Back Pressure (SBP) through the use of a Rotating Control Device (RCD) and an Automated MPD Choke Manifold. CBHP applies precise surface back pressure into the annulus by means of automated MPD system to maintain the annulus pressure when circulating and static. CBHP is achieved during pipe connection when the drill string injection is turned off.

In the previously drilled well, the 0.5ppg pressure window caused an underground blowout while in the thief zone. The Synthetic Oil-Based Mud (SOBM) used in this well was designed to be statically under-balanced during pipe connection to keep ECD within the 220psi window while dynamic and static. The slip joint packer - the weakest link in the annulus system - restricted the MPD SBP to maximum of 350 psi after considering the margin of error. Due to high wellbore friction pressure, the Pressure-While-Drilling (PWD) signal was intentionally turned off 60 meters before Total Depth (TD) was called by reducing the pump speed from 430gpm to 300gpm.

MPD CBHP technique was successfully applied to drill the well until target depth was achieved exceeding the poor performance in the previously drilled well where target depth was not achieved and the well was abandoned due to underground blowout.

This paper describes achieving CBHP with Managed Pressure Drilling technique and the use of an automated system which enables "walk-the-line" between pore and fracture pressure gradient. As a result, the exploration well that was considered "undrillable" with conventional drilling technique in East Kalimantan area was successfully drilled to TD. The ability to precisely control the annulus pressure with statically underbalanced mud is one of distinct advantage of MPD which allow operators to reach planned target depth and retrieve subsurface information through logging operations.
An Experimental Study to Determine Optimal Injection Strategies for Water-Alternating-Solvent Process in Green and Brownfields
Authors: Babadagli T. , Cao N.
Published: October 2017

Considering more than 50% of oil is left on average after primary and secondary methods in conventional reservoirs, techniques to recover the remaining oil from these proven and mature reserves is critically important to meet the future energy demand. Miscible solvent (usually gas) injection is performed in the form of water-alternating gas rather than continuous injection of expensive injectant. In this case, the process should be optimally designed for slug sizes and proper sequences of the solvent considering several controlling parameters including past history of waterflooding (water content) and wettability.

We performed a set of experiments on vertically situated sand pack models saturated with 14cp oil. Heptane was selected as the solvent phase due to high miscibility conditions. Tests were started with waterflooding or solvent injection. Different slug sizes of solvent and water were tested on fully oil- saturated water, oil-wet samples, and samples with connate water (10 and 30%). The amounts of oil and solvent retrieved were monitored using refractometer. Using the collected data, the recovery rates and ultimate recoveries were comparatively analyzed. In addition to the technical feasibility, an economic analysis was performed considering the amount of solvent injected, oil and solvent recovered, and time for recovery.

Starting the process with heptane was technically and economically feasible (pay-out time is shorter) in the short run for both the oil- and water-wet cases. This was true especially if the rock was oil-wet, which yielded faster recovery and higher ultimate recovery. Excessive water injection (up to the plateau level) preceding the solvent injection in the oil-wet case resulted in lower recovery factor whereas this design was very effective in the water-wet case. Therefore, the time to switch to solvent injection was critical in the oil-wet case and a short initial cycle of solvent injection followed by short waterflooding cycle is suggested. In the oil-wet case, initial waterflooding resulted in an inefficient process; while it yielded high ultimate recoveries, the process time was longer than other injection options. In the water- wet case, a greater amount of solvent was needed in the first cycle.
Does the Horizontal Fracture Limit the Fracture Height Growth in Jubaila Source Rock?
Authors: Lubis Wirdansyah , Mulhim Nayef , Al-Sultan Ali , Asiri Khalid , Buraiki Muhammed , Bartko Kirk , Alvarez Angelica Rios
Published: October 2017

Hydraulic fracturing is widely implemented in stimulation of unconventional reservoirs to unlock the hydrocarbon potential in ultra-low permeability formations. Fracture height growth is a critical parameter in unconventional reservoir to maximize the hydrocarbon productivity. The integrated vertical well interpretations from a case study of the pilot well demonstrates the effect of the vertical stress distribution which impacts fracture height growth.

Geomechanical model of a pilot hole was constructed to provide vertical variation of mechanical properties and in-situ stresses. The calibrated geomechanical model has shown that Jubaila source rock has less stiff rock and lower stress than bounding formations. The geomechanical model of the vertical pilot well has shown the overlapping between the minimum horizontal stress and vertical stress in particular, depths restricts the fracture height growth and creates longer horizontal fracture.

Pre-frac injection test was performed, analyzed, and integrated into the geomechanical model. Temperature log was performed to identify the fracture height growth and the results of the temperature log were proportional with the geomechanical model. 3D fracture simulation software was utilized to determine the hydraulic fracture properties. The created fracture simulation model was calibrated to the geomechanical model and temperature log interpretations.

Furthermore, improving hydraulic fracture design depends on understanding the key parameters and lessons learned from the stimulated vertical well and the integrated process. This will help in selecting the landing point, redesign the completion strategy, and optimize the production in the future horizontal wells.
Digital Revolution: How Digital Technologies Will Transform E&P Business Models in Asia-Pacific
Authors: Volkenborn Arnold , Lea-Cox Andrew , Tan Wei Yi
Published: October 2017

Disruptions, both to what the industry does and how it does it, have the potential to transform the oil and gas (O&G) industry. 3 main trends will impact future exploration and production (E&P) business models, namely: (i) lower oil price environment resulting in shrinking margins; (ii) changing energy mix towards natural gas and non-hydrocarbons; and (iii) increased level of connectivity that is driving digital technology adoption and automation.

Digital is the latest buzzword, but what are the implications for an industry that is not new to digital technology? The increasing pace of innovation is driving opportunity for the sector to re-imagine their business models. Digital transformations could unlock USD 1.6-2.5 trillion for the industry, its customers, and wider society (World Economic Forum, 2017). Currently, only 6% of companies can be described as "Digital High Performers" – those who have successfully altered existing business models to capture opportunities for sustainable top-line growth (Accenture Digital, 2017). This paper identifies potential business models for the upstream sector that are built upon technologies such as advanced real-time 3D seismic studies, dynamic portfolio and margin management, well & facilities standardisation, and predictive analytics for flow assurance. Becoming a Digital High Performer requires a mindset shift, which results in completely different lifecycle processes (from workflow-driven to decision time-driven) and organisational structures (from rigid partnerships to a fluid capability ecosystem). Extracting resources faster and cheaper will replace maximising total recovery as a strategic goal; companies that achieve this have the potential to increase returns on invested capital by 3-10 times current levels (Refined, 2016).

The path to capturing the future of O&G requires the right investments in technology and people, paired with flawless execution and governance. Economic scenarios suggest that the combined impact of technology and socio-economic factors could accelerate peak oil demand to as early as 2030 (World Energy Council, 2016). This increases the urgency for energy companies to rethink their strategic direction and how they generate competitive advantage in a rapidly changing world.
An Innovative Organophillic Clay-Free Invert Emulsion Fluid OCF-IEF Facilitates the Successful Running of the Longest 6 5/8-in. Liner in the World
Authors: Nasrallah Mena , Gaber Mohamed
Published: October 2017

To maximize reservoir drainage and production volumes from a field in the United Arab Emirates (UAE), extremely long horizontal sections are necessary through the producing interval. Extended reach drilling (ERD) imposes significant requirements on the drilling operation and complicates the running of the production liner because of the long horizontal displacement. This paper details the design and field execution of an organophillic clay-free invert emulsion fluid (OCF-IEF) that met these ERD requirements and facilitated the longest liner run in the world.

Successfully delivering a gauge wellbore with >20,442 ft of open hole at 90° inclination, followed by running and setting a production liner at target depth (TD), was not deemed achievable using a conventional invert emulsion fluid (IEF). A correctly designed fluid system was necessary to deliver success. The necessary fluid properties included a low rheology profile to minimize equivalent circulating density (ECD) to keep within the fracture gradient, long-term fluid stability, minimal formation damage risk, and low solids content to help minimize friction. A calcium-bromide brine-based low-solids OCF IEF was selected to meet these requirements.

Through the use of this OCF-IEF system, the operator was able to achieve the well objectives, drilling one of the longest wells in the UAE, reaching a TD of 29,075 ft, including a record-breaking 20,442-ft openhole.

The 8 1/2-in. reservoir section was drilled in 37 days, with only three trips necessary to change the bottomhole assembly (BHA). The average rate of penetration (ROP) varied between 70 to 100 ft/hr. The maximum ECD observed did not exceed the fracture gradient at any stage. Consequently, no downhole losses were experienced during the drilling phase. The engineered OCF-IEF achieved a low rheology profile, which minimized the contribution to annular pressure losses. The low rheology profile and low solids content in the IEF resulted in excellent fluid stability with no weighting material SAG. No losses were observed while running the liner, and no indications of tight spots were observed. Friction factors were low (between 0.15 and 0.25), and this facilitated the liner to be run without any issues. Total days on the well were 30 less than planned, which significantly saved both costs and rig time for the operator.

The organophillic clays and organophillic lignites are replaced with various organic polymers to achieve different fluid behaviours (Strand et al. 2016). The novel polymer chemistry of this OCF-IEF together with a low solids content (attributed to using calcium-bromide base brine) resulted in desirable fluid properties that allowed the operator to extend limits, reach new depths, and break records to maximize production and increase revenue.
PROBABILISTIC SPACE FOR CALCULATION OF PROBABILISTIC CHARACTERISTICS OF A THREE-PARAMETER QUEUEING SYSTEM MODEL
Authors: Pavsky Valery , Pavsky Valery , Pavsky Kirill , Pavsky Kirill , Ivanova Svetlana , Ivanova Svetlana , Sedukhin Stanislav , Sedukhin Stanislav
Published: October 2017

A model of queueing theory is proposed that describes a queueing system with three parameters, which has important practical applications. The model is based on the continuous time Markov process with a discrete number of states. The model is formalized by a probabilistic space in which the space of elementary events is a set of inconsistent states of the queueing system; and the probabilistic measure is a probability distribution corresponding to a set of elementary events, that is, each elementary event is associated with the probability of the system staying in this state, for each fixed time moment. The model is represented by a system of ordinary differential equations, compiled by methods of queueing theory (Kolmogorov equations). To find the solution of the system of equations, the method of generating functions is used. For the generating function, a partial differential equation is obtained. Finding the generating function completes the construction of a probability space. The latter means that for any random variables and functions defined on the resulting probability space, one can find their probabilistic characteristics. In particular, analytical expressions of the moments (mathematical expectations and variances) of random functions that depend on time are obtained. The peculiarity of finding a solution is that it is obtained not from the probability distribution, but directly from the partial differential equation, which represents a system of ordinary differential equations. For the probability distribution, the solution was found by a combinatorial method, which made it possible to significantly reduce the computations. To apply the formulas in engineering calculations, we consider the stationary case, to which a considerable simplification of the calculations corresponds. A relationship between a system of differential equations and a polynomial distribution known in probability theory is shown. The results are used in the analysis of the reliability of the operation of scalable computing systems; graphical implementation is shown
STRUCTURAL, BONDING AND ELECTRONIC PROPERTIES OF BULK AND MONOLAYER INDIUM SELENIDE
Authors: Kosobutsky Aleksey , Kosobutsky Aleksey
Published: October 2017

Indium selenide (InSe) is one of the representatives of family of layered semiconductors A3B6 with the anisotropic physical properties finding application in the field of nonlinear optics and optoelectronics. The present paper provides the results of calculations of the major structural parameters (lattice constants, lengths of interatomic bonds, layer thickness and interlayer spacing) and the energy of interlayer coupling Eb in bulk InSe, and also the electronic spectra of the bulk crystal and isolated monolayer performed with the use of computational tools of the density functional theory (DFT). A comparative assessment of accuracy of various approximations of DFT allowing to judge their productivity during the studies of physical characteristics of the A3B6 compounds has been provided. It has been shown that the use of van der Waals functionals of the vdW-DF family gives an opportunity to increase significantly the accuracy of determination of values of the structural parameters of InSe and results in Eb from -50 to -67 meV/atom which is comparable to the energy of interlayer interaction in graphite and a number of related compounds. The modeling of structure of a separate monolayer shows a negligible deviation from the characteristics of layers in a bulk crystal. The calculated electronic spectra provide a conclusion about an essential growth of width of the forbidden energy band of indium selenide upon the transition from bulk material to a monolayer
MODIFICATION BY MICROWAVES OF READY COMMODITY ADHESIVES
Authors: Shevchenko Tatyana , Shevchenko Tatyana , Lobanova Valentina , Lobanova Valentina , Ustinova Yulia , Ustinova Yulia
Published: October 2017

Studies on the microwave modification of complex technical auxiliary materials - import adhesive compositions on the basis of native and modified samples of potato starch with various functional additives have been presented. The paper aims at the replacement of import technical production and the decrease in the consumption of the important materials which are used as wallpaper glues. Features of direct microwave effect on various water-soluble adhesive substances differing from each other in chemical composition and properties have been determined. A mechanism of absorption of microwaves using the air-dry adhesive compositions based on their specific effect on the water which is in the finished dry product has been offered. A possibility of change of the main technological properties of adhesive compositions (viscosity, adhesion) after a direct short-term effect of microwaves on them with the frequency of 2.45 GHz has been proved. It has been established that, in case of preliminary short-term influence of MR in the non-thermal mode, the kinematic viscosity and adhesive forces of various initial types of the glues on a starch basis having a different composition change differently and individually with various time of influence. The change of viscosity and adhesive forces of separate selected adhesive compositions after microwave processing provides a decrease in the cost of the gluing process. The found method of management of technological parameters of gluing has an important practical value and can be introduced in the construction industry for the internal finishing of ready apartments.
INVARIANT PSEUDO-SASAKIAN AND K-CONTACT STRUCTURES ON SEVEN-DIMENSIONAL NILPOTENT LIE GROUPS
Authors: Smolentsev Nikolai , Smolentsev Nikolai
Published: October 2017

This paper studies the existence of left-invariant Sasaki contact structures on the seven-dimensional nilpotent Lie groups. It is shown that the only Lie group allowing Sasaki structure with a positive definite metric tensor is the Heisenberg group A complete list of 22 classes of seven-dimensional nilpotent Lie groups which admit pseudo-Riemannian Sasaki structures is found. A list of 25 classes of seven-dimensional nilpotent Lie groups admitting K-contact structures, but not pseudo-Riemannian Sasaki structures, is also presented. All the contact structures considered are central extensions of six-dimensional nilpotent symplectic Lie groups. Formulas that connect the geometric characteristics of six-dimensional nilpotent almost pseudo-Kähler Lie groups and seven-dimensional nilpotent contact Lie groups are established. As is known, for six-dimensional nilpotent pseudo-Kähler Lie groups the Ricci tensor is always zero. In contrast to the pseudo-Kӓhler case, it is shown that on contact seven-dimensional Lie algebras the Ricci tensor is nonzero even in directions of the contact distribution
Nano-TiO2, ultrasound and sequential nano-TiO2/ultrasonic degradation of N-acetyl-para-aminophenol from aqueous solution
Authors: Ayanda Olushola S. , Nelana Simphiwe M. , Petrik Leslie F. , Naidoo Eliazer B.
Published: October 2017

The application of nano-TiO2 as adsorbent combined with ultrasound for the degradation of N-acetyl-para-aminophenol (AAP) from aqueous solution was investigated. The nano-TiO2 was characterized by means of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR). Experimental results revealed that the adsorption of AAP by nano-TiO2 fitted the pseudo-second-order kinetic model, the equilibrium could be explained by the Freundlich isotherm and the treatment process is exothermic. The optimum removal efficiency of AAP (128.89 mg/g (77.33%)) was achieved at pH 4 when 0.03 g of nano-TiO2 was mixed with 50 mL of 100 mg/L AAP aqueous solution at ambient temperature, 60 min contact time, and a stirring speed of 120 rpm. Ultrasound at 20 kHz and pH 3 was favorable and it resulted in 52.61% and 57.43% removal efficiency with and without the addition of nano-TiO2, respectively. The degradation of AAP by ultrasound followed by nano-TiO2 treatment resulted in approximately 99.50% removal efficiency. This study showed that a sequential ultrasound and nano-TiO2 treatment process could be employed for the removal of AAP or other emerging water and wastewater contaminants.
Mechanism of 1,4-dioxane microbial degradation revealed by 16S rRNA and metatranscriptomic analyses
Authors: Guan Xiangyu , Liu Fei , Wang Jing , Li Caoxiang , Zheng Xiaoxuan
Published: October 2017

1,4-Dioxane (dioxane), a probable human carcinogen, often exists in industrial wastewater and domestic sewage. In this study, we applied 16S rRNA and metatranscriptomic methods to analyze the dioxane biodegradation mechanism by activated sludge. Tetrahydrofuran (THF) was added as an essential co-metabolite to promote the degradation of dioxane. We found the dioxane removal ratio increased with increasing THF concentrations. When the THF concentration increased from 60.0 to 200.0 mg/L, the dioxane degradation rate was stable. Three additions of ∼60.0 mg/L THF resulted in better dioxane degradation than one addition of 200 mg/L THF. Ammonia-oxidizing and denitrifying bacteria with methane monooxygenases (MOs) and ammonia MOs played the most important roles during the degradation of dioxane. Kyoto Encyclopedia of Genes and Genomes metabolic pathway and functional genes analyses showed that the activated sludge system was complex and stable when dioxane was added. In future studies, primers should be designed to identify specific bacteria and functional MO genes, which would help reveal the function of various bacteria and their MOs during dioxane degradation.
Autologous Cell Therapy for Vascular Regeneration: The Role of Proangiogenic Cells
Authors: Bianconi Vanessa , Fallarino Francesca , Mannarino Massimo Raffaele , Bagaglia Francesco , Kararoudi Meisam Naeimi , Aragona Caterina Oriana , Romani Rita , Pirro Matteo
Published: October 2017

Background:

Autologous cell therapy represents a novel treatment option for vascular
regeneration in different disease conditions, with experimental and clinical studies indicating a therapeutic
potential for proangiogenic cells (PCs), including endothelial progenitor cells, in the treatment of
coronary and peripheral artery disease.

Objective: To provide a summary of the therapeutic potential of PCs administration or mobilization in
peripheral artery disease, ischemic heart and cerebrovascular diseases, diabetic microvascular complications
and inflammatory rheumatic diseases.

Methods: We undertook a search of bibliographic databases for peer-reviewed research literature on the
role of PCs in vascular regeneration in preclinical and clinical models.

Results: Improvement of ischemic symptoms has been reported in different trials evaluating PCs for the
treatment of critical limb ischemia. However, in this setting, contrasting results from meta-analyses
question the long-term clinical efficacy of PC-based approaches. Preclinical studies and clinical trials
support the safety and feasibility of PC therapy in the treatment of ischemic heart and cerebrovascular
diseases, while evidence indicating a benefit on hard clinical outcomes is uncertain. Despite accumulating
experimental results support a therapeutic role for PCs in diabetic retinopathy, results from randomized
clinical trials are lacking. Whether PC therapy may limit premature atherosclerosis and reduce cardiovascular
risk in inflammatory rheumatic diseases needs to be investigated.

Conclusion: Although the potential clinical applications of PCs are accumulating, there is also evidence
of multiple limitations for autologous PC therapy. Thus, novel strategies aimed at improving PC
viability and angiogenic function are warranted in order to improve the efficacy of cell therapy
applications.
The Renal Outer Medullary Potassium Channel (ROMK): An Intriguing Pharmacological Target for an Innovative Class of Diuretic Drugs
Authors: Calderone Vincenzo , Martelli Alma , Piragine Eugenia , Citi Valentina , Testai Lara , Breschi Maria C.
Published: October 2017

In the last four decades, the several classes of diuretics, currently available for
clinical use, have been the first line option for the therapy of widespread cardiovascular
and non-cardiovascular diseases. Diuretic drugs generally exhibit an overall favourable
risk/benefit balance. However, they are not devoid of side effects. In particular, all the
classes of diuretics cause alteration of potassium homeostasis.

In recent years, understanding of the physiological role of the renal outer medullary potassium
(ROMK) channels, has shown an intriguing pharmacological target for developing
an innovative class of diuretic agents: the ROMK inhibitors. This novel class is expected
to promote diuretic activity comparable to (or even higher than) that provided by the
most effective drugs used in clinics (such as furosemide), with limited effects on potassium
homeostasis.

In this review, the physio-pharmacological roles of ROMK channels in the renal function are
reported, along with the most representative molecules which have been currently developed
as ROMK inhibitors.
Pharmacological Targeting of Neuronal Kv7.2/3 Channels: A Focus on Chemotypes and Receptor Sites
Authors: Miceli Francesco , Soldovieri Maria V. , Ambrosino Paolo , Manocchio Laura , Mosca Ilaria , Taglialatela Maurizio
Published: October 2017

Background:

The Kv7 (KCNQ) subfamily of voltage-gated potassium channels
consists of 5 members (Kv7.1-5) each showing characteristic tissue distribution and
physiological roles. Given their functional heterogeneity, Kv7 channels represent important
pharmacological targets for the development of new drugs for neuronal, cardiovascular
and metabolic diseases.

Objective: In the present manuscript, we focus on describing the pharmacological relevance
and potential therapeutic applications of drugs acting on neuronally-expressed
Kv7.2/3 channels, placing particular emphasis on the different chemotypes, and highlighting
their pharmacodynamic and, whenever possible, pharmacokinetic peculiarities.

Methods: The present work is based on an in-depth search of the currently available scientific
literature, and on our own experience and knowledge in the field of neuronal Kv7
channel pharmacology. Space limitations impeded to describe the full pharmacological
potential of Kv7 channels; thus, we have chosen to focus on neuronal channels composed
of Kv7.2 and Kv7.3 subunits, and to mainly concentrate on their involvement in epilepsy.

Results: An astonishing heterogeneity in the molecular scaffolds exploitable to develop
Kv7.2/3 modulators is evident, with important structural/functional peculiarities of distinct
compound classes.

Conclusion: In the present work we have attempted to show the current status and growing
potential of the Kv7 pharmacology field. We anticipate a bright future for the field,
and express our hopes that the efforts herein reviewed will result in an improved treatment
of hyperexcitability (or any other) diseases.
Longitudinal Neuropsychological Outcome in Taiwanese Alzheimer's Disease Patients Treated with Medication
Authors: Yang Yuan-Han , Wu Meng-Ni , Chou Ping-Song , Su Hui-Chen , Lin Sheng-Hsiang , Sung Pi-Shan
Published: October 2017

Background:

The longitudinal change of neuropsychological tests (NPTs) in treated Alzheimer's
disease (AD) is essential to understand the interplay of a therapeutic response from medication
and a disease decline due to degenerative processes. The aim of our study is to investigate the annual
cognitive progression as measured by commonly used NPTs in treated AD patients and to assess the potential
predictors of disease progression.

Methods:

Participants (N=455) diagnosed with AD and treated with cholinesterase inhibitors (ChEIs) or
memantine at memory clinics in three hospitals in southern Taiwan from January 2009 to December
2014 were enrolled in this prospectively registered study. The mean follow-up duration was 3.2 ± 0.9
years. The patients' severity of AD ranged from very mild (clinical dementia rating (CDR) scales = 0.5)
to moderate (CDR = 2.0). At baseline and for each year, participants were assessed by various NPTs
commonly used in clinical practice, including the Mini-Mental State Examination (MMSE), Cognitive
Abilities Screening Instrument (CASI), CDR and CDR-sum of boxes (CDR-SB). All enrolled participants
were assessed for at least two years during follow-up. We used mixed-effect models to examine
annual progression in the whole group and to compare the cognitive progression between the subgroups
with very mild AD and mild to moderate AD. Potential predictors of disease progression, including age,
gender, the type of ChEI, and Apolipoprotein E (APOE) genotype, were also analyzed.

Results:

Among the study population, the rate of change in MMSE scores were -1.15 points per year,
CASI scores were -4.27 points per year, and CDR-SB scores were 0.81 points per year. The slope of
annual changes of NPTs differed significantly between the CDR 0.5 group and the CDR 1 to 2 group.
The most significant predictors of the faster progression were increasing age and higher CDR stage at
entry; however, different types of ChEI therapy (donepezil vs. rivastigmine users), and APOE genotype
were not associated with the rate of disease progression.

Conclusions:

This longitudinal data shows the mean annual change of the MMSE, CASI, CDR, and
CDR-SB in treated AD patients. The data may provide clinicians with information regarding to the cognitive
decline rate in every year while their AD patients receive approved pharmacological therapy in
real-world practice. Increasing age and severity of dementia when receiving therapy are the main factors
that associated with faster deterioration.