bluuebunny/crossref_metadata_2025 huggingface dataset:
Wells’ Water Cut Measurements with Limitations of Testing Facilities in the Field
Authors: Shektebayeva Raziya , Bissakayev Beibit , Iraliyev Amangali , Mardanov Almas , Karatayev Kanat , Saada Tamer , Madeley Benjamin , Brancolini Alberto , Di Federico Emanuele Giustino
Published: October 2018

The objective of this article is to demonstrate recent results of a water cut measurement campaign in the Karachaganak oil and gas condensate field. Historical, inaccurate well water cut assessment was due to the limitations of well test facilities which led to uncertainty in short- and long-term production forecasts. Several approaches were conducted to eliminate uncertainties in water cut measurements and to evaluate and define adequate tools to use for future water cut analysis.

The use of a mobile sampling flow loop installed at the well head, where turbulent multiphase flow is guaranteed, was a safe and reliable approach to measure the water cut of the producing low and high productivity wells. Sampling and analyzing the fluid at the well site at various operating well head pressures, frequently and for long periods of time, resulted in better understanding of water cut dependence with changes in drawdown. In addition to the use of sampling on site, the optical sensor (OS) technology was a trial tested on two wells along with the sampling flow loop to confirm the accuracy of the technology.

The existing test separators were not designed to handle high water rates; moreover, due to the complexity of the produced hydrocarbon, multiphase flowmeters are not able to accurately measure the correct fluid phase contribution and, as a result, inaccurately estimate phase rates.

The OS tool demonstrated accurate real-time water cut readings in the liquid phase, when compared with the flow loop samples, as long as a turbulent flow is guaranteed during measurement. Thus, this technology can be considered as an accurate tool for water cut measurements. The possibility of temporary and permanent installation of the optical sensor tool at the well site or test lines is under evaluation.

The current field development focuses on improved recovery from the oil rim which is above a weak aquifer. In the historically developed areas of the field this aquifer is separated from the hydrocarbons by impermeable shale and therefore water production has been minimal. Current and future development requires the drilling of new wells in areas not protected by barriers; this has led to a number of recent wells having a relatively early water breakthrough.

As a result of accurate water cut measurements, unallocated water in the field was well defined and led to better control of water producing wells to maintain stability of process facilities. This application confirmed the limitations and low level of accuracy of the existing well test separators.

The successful campaign to improve water cut assessment was critical to update and re-evaluate production wells’ operating philosophy, reservoir management, and the future development strategy of the carbonate reservoir.
Analysis of Depositional Environment within Karaton-Tengiz Uplift Zone in Southeastern Part of the Pre-Caspian Basin
Authors: Yeskozha Bazar , Aimagambetov Marat , Ismagulova Saltanat
Published: October 2018

The present paper describes the results of analysis of depositional environment and tectonic setting within Karaton-Tengiz uplift zone in the southeastern part of the Pre-Caspian basin. The main purpose of the study is generalization and interpretation of geological and geophysical data for creation of stratigraphic charts and a description of lithological and tectonic processes for reconstruction of the structural history of pre-salt prospective traps located close to Tengiz field.

It is known that carbonates are "born, not made"; hence, their characteristics can give an insight into their depositional environment. The combination of such factors as availability of the light, warm climate, chemical composition and transparency of the water define the growth of the reef-building organisms. The highest carbonate production takes place close to the water surface; therefore, facies and texture of carbonates may be linked to the sea level changes. This means that understanding of the depositional environment and sequence stratigraphy may be used for a potential reservoir description where no well data is available. As a general understanding of the relative sea level fluctuations and its effect on carbonate growth, comparison of vertical thickness of studied platforms was carried out.

Analysis of regional seismic reflectors P3 (Top of Middle Devonian, tentative), P2D (Top of Upper Devonian), P2 (Top of Carboniferous), P1 (Top of Permian), VI (Kungurian salt deposits), V (surface of unconformity, Triassic), III (Top of Jurassic), II (Top of Lower Cretaceous) was also carried out for understanding of tectonic processes. Dipping of reflectors, thickness and depth variation of time-equivalent units, unconformities may indicate the change in tectonic setting. The shallowest depth of top of carbonates is observed on Tazhigali-Pustynnaya structure, gradually deepening towards Ansagan and Maksat to the south-southeast. Also, post-salt III and V reflective horizons are inclined from the north to the south of Karaton-Tengiz uplift zone.

Tectonic deepening in the south-southeast direction took place in several stages. The first stage, most probably, took place in Late Devonian–Early Carboniferous, as the result of which Ansagan and Maksat structures drowned. In the northern part of the Karaton-Tengiz uplift, the growth of reefs continued up to Late Carboniferous.

Well logging interpretation and published papers were integrated when possible. As the result, a conceptual model of the geological history and stratigraphic charts were created for the studied region.
Evaluation of In-Situ Combustion Efficiency in Karazhanbas Oilfield, Western Kazakhstan
Authors: Abishev Aziz , Tokarev Vitaliy , Sagyndikov Marat
Published: October 2018

Among various processes of EOR, in-situ combustion (ISC) received an increased attention in the world. Such specific features as applying to deep reservoirs and at any stages of depletion, lack of transport heat losses, cheap working agent (air) makes this method most thermally efficient and economically comparable to steamflooding.

The Karazhanbas experience of ISC implementation is a bright example of well-designed project. After the estimation of reserves in 1978 there were created two large fields to develop thermal EOR methods. They are the VVG field to develop in-situ combustion and the PTV field to develop the steam flooding. Unfortunately, this project was not fully completed and was interrupted before the planned deadline because of the current economic situation in the country in the 90s. Anyway the project demonstrated high technological and economic efficiency.

The study (article) describes a history of project, results of logging data, problems encountered during combustion process and comparative analysis of developed and existing methods.
Standout Concept of Well Clean-up and Testing—Secures Long-term Sustainable Evolution of the Field
Authors: Dombayeva Anar , Viti Massimo , McGachy David , Thorn Nigel
Published: October 2018

The Karachaganak (KGK) field is situated within an environmentally sensitive location which includes a conservation area containing lakes, woodland and abundant wildlife. Additionally, surrounding the field there are several inhabited villages. As in other parts of the world, if well operations are not properly managed, there is the potential to directly impact this fragile environment, as a result of HC flaring with emissions containing both poisonous H2S and toxic SO2 during the well operations.

Despite applying best-in-class environmental drilling and completion practices in the well construction processes, there remained the challenge of how to reduce emissions resulting from well clean-up activities in the field, with the eventual goal of achieving zero emissions.

This paper outlines the transition of well clean-up and testing towards purely three phase "zero emission", broadly describing the evolution from conventional three phase flaring to a robust zero emissions approach.

The transition required new technologies to be implemented in stages which were all subject to; high level design reviews and rigorous HAZOP activities to, both define and guarantee the safe operational envelope at field implementation stage.

The result of this implementation are as follows: Maximizing oil recovery at highest value within optimal cost.Putting the newly drilled wells on production in advance and reviving suspended wells.Significantly reducing downtime.With to date a significant environmental impact reduction in the region of 95%.

The project anticipates deploying the last of the enabling technologies in the field in 4th Quarter 2018, which should see Karachaganak Petroleum Operating b.v. (KPO) achieve its long term aim of "zero emissions" during well clean-up phases.
Staged Acid Stimulation Initiative in Giant Carbonate Reservoir
Authors: Manakhayev Ruslan , Abilgaziyeva Nazgul , Bopiyev Chingiz , Saduakassov Bekzhan , Abdrazakov Dmitriy , Stepanov Vladimir , Se Yegor , Clarke John , Kamispaev Akylbek , Tyre Robert , Nurmanov Sagdi , Ismailov Bolat , Argynov Daniyar
Published: October 2018

Tengiz field is a super-giant carbonate reservoir located in the Western Kazakhstan. The carbonate matrix consists of almost pure calcite, which makes it very attractive for acid stimulation. Over the years matrix acid stimulation has been successfully used in Tengiz to remove near wellbore damage and enhance well productivity.

Despite successful production response from acid stimulation in the past, it was noticed from poststimulation surveillance analysis that tighter and less depleted intervals were often left untreated. This observation suggested that chemical diverting agents were not effective for long completion intervals and further opportunity for improvement was identified. In addition, existing two phase retarded acid had limitation due to high viscosity and had known issues during plant flowback.

New acid stimulation design has been proposed and successfully executed in three newly drilled wells. This acid treatment utilized staged stimulation concept, where diversion was ensured by mechanical isolation of lower intervals with inflatable packer. New single phase retarded acid system was introduced to address operational and plant processing challenges with two phase retarded acid. Core flow tests were performed prior stimulation to evaluate effectiveness of different acid systems. Results of core flow tests and wireline log data were used during simulations on new generation of matrix acidizing modeling software to determine parameters for optimal wormhole creation.

Proper planning and thorough technical assessment enabled execution of staged acid stimulation with new acid system incident free with less than 10% incremental cost in all three wells. Post-job surveillance program is in place to evaluate acid diversion and production contribution from tighter and less depleted intervals.
Utilization of Mobile Multiphase Flow Meter in an Uncertain H2S Media: Precautions and Benefits
Authors: Macary Sameh , Muhamadiyev Hasan , Mollaniyazov Eldar , Kaipov Yermek , Agayev Aydyn
Published: October 2018

The deployment of Multi-Phase Flow Meter (MPFM) from commissioning to execution campaign in harsh offshore/H2S uncertainty conditions is presented. The case study was performed in Lam and Zhdanov fields operated by Dragon Oil, Offshore Caspian-Turkmenistan. The objective was to enhance the quality of well testing and allocation factor by comparing test separators (TS) measurements against multiphase flow meter (MPFM) readings and, in a bigger scope to converge the difference versus onshore plant measurements of oil and water.

Commissioning stage of MPFM was started off by comparing its results with TS. Comparison program was made and followed by considering the operating envelope of both technologies: MFPM and TS, input PVT parameters, measurement conditions and success criteria. Water-liquid ratio (WLR) and water rate from MPFM was compared against wellhead samples utilizing automatic centrifuge and total water at plant.

MPFM was subjected to measure flow during both: well clean-up stage and production logging of a slugging well. High gas volume fraction and scale/wax precipitation have required methodology development to maintain the accuracy of MPFM.

14 wells were subjected to comparison test showing differences in gas and liquid rates between MPFM and TS are within acceptable criteria while difference in water rate was high due to slugging nature of flow. High-frequency measurements of WLR from MPFM showed water rates accompanying slugging were consistent with wellhead sampling and total onshore water production. Two-phase test separator was underestimating the water due to few sampling and improper separation at manual centrifuge.

In high gas volume fraction equal to 98.5% and above MPFM accuracy in liquid rate becomes very sensitive to reference point of gas. To maintain the liquid accuracy, the in-line measurement of gas point was done so that accuracy of liquid measurements improved.

MPFM has identified wells with scale and wax precipitation, which can be observed from photon counts deviation at two energy levels of gamma-ray spectrum. By adding 3rd energy level, it was possible to estimate the thickness of scale and wax on the wall of meter venturi throat and hence maintaining the MPFM flowing rate accuracy.

MPFM campaign showed accurate measurement of water for Cheleken in addition to adding efficient well testing frequency while providing reliable high data frequency. This case study shows the first mobile MPFM application in Caspian offshore for producing wells’ testing. Results in comparison with TS signifies better and faster ways to calibrate the surface TS. MPFM testing campaign has led to the early identification of possible flow assurance issues and consequently, development of methodologies and recommendations to ensure reliability of MPFM and permanent test separators.
Integrated Asset Modeling in West Siberia: A Case Study
Authors: Batalov D. A. , Yusupov R. Y. , Zykov M. A. , Zipir V. G. , Gontarev D. P. , Kukushkin V. , Bayguzov R. , Kraynova E. , Krivokorytova M. , Kharkovsky A.
Published: October 2018

As part of the LUKOIL smart-field project, the company develops and implements integrated modeling solutions in all its assets. LUKOIL-West Siberia, a subsidiary company that is LUKOIL's leading hydrocarbon producer, has chosen two pilot assets in Yamal to implement such technology solutions. This paper describes the creation and implementation of two integrated models, as well as model of gas transportation system from a group of fields located in the Yamal and the Krasnoyarsk region. Each integrated model includes the following components: reservoir – well – gathering system – processing. The results of the project implementation allowed to increase production performance and economic viability of the operator company and provided technology that enabled to forecast production rates with high accuracy.
The Key Development Geological Technology Research and Application of Heavy Oil Reservoir
Authors: Chen Zhong
Published: October 2018

This research is aimed at enhancing the oil recovery and re-development of heavy oilfield by development geology as the development of many heavy oilfieldsin the world hasentered middle-late stages at present. The development effect has become worse and worse gradually. So, it isan urgent thing to look for any effective alternative methods to sustain the stable production of oilfield.

This research formed four key technologies of development geology. The first is micro structure fine interpretation technology for theproblem aforementioned. Second, complex fault block oil reservoir prediction technology, including multi-attribute reservoir inversion prediction technology, tracking and prediction individual oil layer by combining well-log and seismic technology, confirming lateral continuity of sandstone bodies by seismic phase shifting technology. The third is favorable oil layer accurate evaluation technology, including favorable oil layer identification and tracking and depicting succession oil layer technology. The last is integration research of hard-to-recover reserve development and rolling exploration through conducting oil reservoir optimum selection.

This research further exploited the favorable oil accumulation zone by deepened integral structure analysis, realized new breakthrough of rolling and increasing reserve on account of intensifying the understanding of old field margin area, set up layer division development model of hard-to-recover reserve based on originating the idea of fine evaluation of individual oil layer and well-practicedthe integration applicationof the key technologies of development geology in the practice of the main developed heavy oilfield in Liaohe Basin. This research has greatly enhancedthe oil recovery factor of more than 10% to the first development andfinally realized the stable production of theoilfield.

This research established three innovative concepts, holistic research concept of oil development geology territory, individual oil layer fine evaluation concept and building the composite development concept allowing for the coexistence of multiple well types and varied development methods. It would have an important reference value to the continueddevelopment of heavy oilfield.
Book Review : NEUROTRAUMA AND CRITICAL CARE OF THE BRAIN
Authors: Periska Septian Dewi
Published: October 2018

Traumatic Brain Injury (TBI) is one of the leading cause of death and disability. TBI and spinal cord injuries have impacts on patients life, their families and also to the comunity. This edition retained the book structure of the first edition with emphasis in critical care and also it offers review the updated guideline recommendation. A review gives the reader not only summary of the content but also a critical assesment about the content. Additionally, this book gives the reader content about a brief review of a basic ethical framework. The concern is not only about science but also about prehospital care, critical care, outcome, ethical issue, prevention and sosioeconomic.
Antimicrobial Activity of Different Antimicrobial Peptides (AMPs) Against Clinical Methicillin-resistant Staphylococcus aureus (MRSA)
Authors: Ciandrini Eleonora , Morroni Gianluca , Arzeni Daniela , Kamysz Wojciech , Neubauer Damian , Kamysz Elzbieta , Cirioni Oscar , Brescini Lucia , Baffone Wally , Campana Raffaella
Published: October 2018

Background:

Antimicrobial research is being focused to look for more effective therapeutics
against antibiotic-resistant infections caused by methicillin-resistant Staphylococcus aureus (MRSA). In
this direction, antimicrobial peptides (AMP) appear as promising tool.

Objectives:

This study evaluated the antimicrobial activity of different AMPs (Citropin 1.1, Temporin
A, Pexiganan, CA(1–7)M(2–9)NH2, Pal-KGK-NH2, Pal-KKKK-NH2, LL-37) against human MRSA
clinical isolates.

Methods:

The Minimum Inhibitory Concentration (MIC) was assessed for each AMP; then, the most
active ones (Citropin 1.1, Temporin A, CA(1–7)M(2–9)NH2 and Pal-KGK-NH2) were tested against
selected MRSA strains by time-kill studies.

Results:

The lowest MIC value was observed for Pal-KGK-NH2 (1 µg/ml), followed by Temporin A (4-
16 µg/ml), CA(1–7)M(2–9)NH2 (8-16 µg/ml) and Citropin 1.1 (16-64 µg/ml), while higher MICs were
evidenced for LL-37, Pexiganan and Pal-KKKK-NH2 (> 128 µg/ml). In time-kill experiments, Citropin
1.1 and CA(1-7)M(2-9)NH2 showed a relatively high percentage of growth inhibition (>30 %) for all the
tested MRSA clinical isolates, with a dose-dependent activity resulting in the highest percentage of bacterial
growth inhibition (89.39%) at 2MIC concentration.

Conclusion:

Overall, our data demonstrated the potential of some AMPs against MRSA isolates, such
as Citropin 1.1 and CA(1-7)M(2-9)NH2, that represents a promising area of development for different
clinical applications.
Design of Patient Specific Spinal Implant (Pedicle Screw Fixation) using FE Analysis and Soft Computing Techniques
Authors: Biswas Jayanta Kumar , Dey Swati , Karmakar Santanu Kumar , Roychowdhury Amit , Datta Shubhabrata
Published: October 2018

Background:

This work uses genetic algorithm (GA) for optimum design of patient
specific spinal implants (pedicle screw) with varying implant diameter and bone condition. The optimum
pedicle screw fixation in terms of implant diameter is on the basis of minimum strain difference
from intact (natural) to implantation at peri-prosthetic bone for the considered six different
peri-implant positions.

Methods:

This design problem is expressed as an optimization problem using the desirability function,
where the data generated by finite element analysis is converted into an artificial neural network
(ANN) model. The finite element model is generated from CT scan data. Thereafter all the
ANN predictions of the microstrain in six positions are converted to unitless desirability value varying
between 0 and 1, which is then combined to form the composite desirability. Maximization of
the composite desirability is done using GA where composite desirability should be made to go up
as close as possible to 1. If the composite desirability is 1, then all ‘strain difference values in 6 positions’
are 0.

Results:

The optimum solutions obtained can easily be used for making patient-specific spinal implants.
Visualization of Cartilage from Knee Joint Magnetic Resonance Images and Quantitative Assessment to Study the Effect of Age, Gender and Body Mass Index (BMI) in Progressive Osteoarthritis (OA)
Authors: Matada Mallikarjunaswamy Shivagangadharaiah , Holi Mallikarjun Sayabanna , Raman Rajesh , Jayaramu Suvarna Sujana Theja
Published: October 2018

Background:

Osteoarthritis (OA) is a degenerative disease of joint cartilage affecting
the elderly people around the world. Visualization and quantification of cartilage is very much essential
for the assessment of OA and rehabilitation of the affected people. Magnetic Resonance Imaging
(MRI) is the most widely used imaging modality in the treatment of knee joint diseases. But
there are many challenges in proper visualization and quantification of articular cartilage using
MRI. Volume rendering and 3D visualization can provide an overview of anatomy and disease
condition of knee joint. In this work, cartilage is segmented from knee joint MRI, visualized in 3D
using Volume of Interest (VOI) approach.

Methods:

Visualization of cartilage helps in the assessment of cartilage degradation in diseased
knee joints. Cartilage thickness and volume were quantified using image processing techniques in
OA affected knee joints. Statistical analysis is carried out on processed data set consisting of 110
of knee joints which include male (56) and female (54) of normal (22) and different stages of OA
(88). The differences in thickness and volume of cartilage were observed in cartilage in groups
based on age, gender and BMI in normal and progressive OA knee joints.

Results:

The results show that size and volume of cartilage are found to be significantly low in OA
as compared to normal knee joints. The cartilage thickness and volume is significantly low for
people with age 50 years and above and Body Mass Index (BMI) equal and greater than 25. Cartilage
volume correlates with the progression of the disease and can be used for the evaluation of the
response to therapies.

Conclusion:

The developed methods can be used as helping tool in the assessment of cartilage
degradation in OA affected knee joint patients and treatment planning.
Content Analysis, Cytotoxic, and Anti-metastasis Potential of Bioactive Polysaccharides from Green Alga Codium intricatum Okamura
Authors: Vasquez Ross D. , Lirio Stephen
Published: October 2018

Background:

Codium intricatum, locally known as Pukpuklo, is a seasonal and edible green
alga found in Ilocos Norte, Philippines. In this study, the biochemical content, cytotoxic and inhibitory
potential against Matrix Metalloproteinase-1 (MMP-1) production of the polysaccharide-protein fractions
from C. intricatum is first reported. MMPs are novel targets for therapeutic intervention with the
potential to inhibit tumor growth, metastasis and invasion either on their own or in conjunction with
cytotoxic treatments.

Methods:

Water-soluble Crude Polysaccharide (CP) and its fractions (CFs) from C. intricatum were
isolated using hot water and ion-exchange chromatography and analyzed using different analytical techniques.
Cytotoxicity against MCF-7 breast cancer cells and Human normal Dermal Fibroblasts (HnDFs)
was determined by MTT assay. The MMP-1 inhibitory potential was tested in UVB exposed Human
normal Dermal Fibroblast Cells.

Results:

CP and CFs afforded carbohydrates (2.07-16.1%), sulfates (1.81%- 9.9%), protein (0.05-2.7%),
ash (<77.2%), lipids (<1.0%) and uronic acid (0.15- 4.49%). FT- IR and NMR spectra of CP and CFs
exhibited absorption peaks comparable to sulfated galactans. Both CP and CFs significantly inhibited
the growth of breast cancer (MCF-7) in a concentration-dependent manner (p<0.05), induced proliferation
of HnDFs, inhibited the production of Matrix metalloproteinase-1 (MMP-1) in UV-B induced
HnDFs (p<0.05).

Conclusion:

Results are highly suggestive that polysaccharide fractions from C. intricatum are bioactive
molecules with cytotoxic and anti-metastasis potential.
Antispermatogenic Effect of Piper betel Leaf Stalk Extract with Reference to Kinetic Studies of 17β-hydroxy Steroid Dehydrogenase Enzyme in Testes of Albino Rats
Authors: Amgoth Govardhan Naik , Venkataramanaiah P. , Challa Changamma
Published: October 2018

Background:

In the development and maintenance of male reproductive function and fertility,
steroidogenesis plays a key role.

Aims:

The aim of the present study was to investigate the effect of the betel leaf stalk extract on 17β-
hydroxy steroid dehydrogenase activity levels.

Methods:

The observed elevation in testicular cholesterol levels may be due to decreased androgen
production, which resulted in impaired spermatogenesis. The decreased steroidogenic enzyme 17β-
HSD activity represents decreased androgen production by the extract administration. Reduction in
enzyme active site density and Km value revealed that there was a reduction in enzyme-substrate affinities
and rate of E-S complex breakdown in the administered rat testes.

Results & Conclusion:

The administration of betel leaf stalk extract resulted in decreased enzyme
content probably through impaired synthesis.
α-Glucosidase and α-Amylase Inhibitory Effect and Antioxidant Activity of Aerial Part from Linaria aegyptiaca L.
Authors: Bekhaoua Abir , Khacheba Ihcen , Boussoussa Hadjer , Yousfi Mohamed
Published: October 2018

Background:

The genus Linaria belongs to the Scrophulariaceae family. It is a large genus comprising about 200 species. Various parts of several Linaria species have been reported to exhibit various biological effects. In Algeria especially in the Sahara and steppe regions, the different species of Linaria have several uses in dietary application.

Objective:

The aims of this study are to evaluate the α-Glucosidase and α-Amylase inhibitory effects and the antioxidant activity using in vitro assays by an organic extract of the aerial part of Linaria aegyptiaca collected in two months, April and June, from southern Algeria.

Methods:

The extracts were obtained with successful maceration in (hexane, dichloromethane, acetone and methanol). The phenolics and flavonoids contents of L. aegyptiaca extracts were evaluated with Folin- Ciocalteu and aluminum chloride reagents, respectively. Then, we studied their inhibitory effects on α-Glucosidase and α-Amylase enzymes. The antioxidant potential was determined in vitro with DPPH, ABT and Phosphomolybdate tests.

Results:

The highest phenolic and flavonoid content were detected in the methanolic extracts of Linaria aegyptiaca collected in April. All the extracts showed good inhibitory activity on both enzymes, where the best activity was against α- amylase by acetonic extract collected in June with an IC50 = 95.03 μg/ml. The evaluation of antioxidant activity showed that all the extracts exhibited a good antioxidant capacity compared to standard antioxidants.

Conclusion:

The aim of this research is to establish the anti-diabetic properties and the probable alpha glucosidase and alpha amylase inhibitory activities of Algerian Linaria aegyptiaca species. These results show that this species has good antioxidant properties and a good potential for hyperglycemia management, too. The Algerian Linaria aegyptiaca can be considered as a natural source of anti-hyperglycemic treatment and might be interesting for the prospect of new molecules with antidiabetic effect.
Parasitic Infections in Children with Disability in Resource Poor Settings: The Research Gaps
Authors: Sultana Yasmin , Karim Sabina , Banik Gouri Rani , Rashid Harunor , Lee Rogan
Published: October 2018

The burden of parasitic infections among children with disability in resource-poor settings
has not been summarised through a focused review. Here, we have summarised the key studies
reporting the burden of parasitic infections among children without and with a disability. In
most instances, among children without disability, Giardia or soil-transmitted helminths dominate
the epidemiology, while among disabled individuals, enteric protozoa are the predominant parasites
to be reported in both resource-rich and resource-poor countries. Cryptosporidium is generally
the leading protozoan to be detected among these populations but all other parasites have been
detected in varying frequencies. There is a paucity of data on the precise epidemiology of parasitic
infections in children with disability. A large-scale epidemiological study, using modern genomic
methodology, is a research priority.
Performance Analysis of QMF Filter Bank For Wireless Voip in Pervasive Environment
Authors: Luhach Ravindra , Jha Chandra K. , Luhach Ashish K.
Published: October 2018

Background:

Voice over Internet Protocol (VoIP) has emerged as one of the most significant
technology in the field of communication and evolved as a substitute to the conventional communication
method as the Public Switched Telephone Network (PSTN). Along with the advantages such
as scalability and security, VoIP has some threats such as voice quality and interference that must be
dealt with. The voice quality in VoIP is degraded when transmitted over a computer network due to delay,
jitter and packet loss etc. Packet loss is one of major reasons for the signal quality degradation.

Objective:

In this research article, Quadrature Mirror Filter Bank (QMF) has been implemented in
wireless VoIP system to enhance the quality of the signals transmitted.

Results:

The performance has been evaluated under varying network conditions of packet loss.

Conclusion:

Significant improvement has been observed in the quality of VoIP signal.
Temporal Pattern Specifications for Self-Adaptive Requirements
Authors: Yahiaoui Ayoub , Bendjenna Hakim , Roose Philippe , Chung Lawrence , Amroune Mohamed
Published: October 2018

Background:

Systems whose requirements change at a rate that necessitates adaptation
without human intervention are called self-adaptive systems, and they have the ability to adjust their
behavior autonomously at run-time in response to their environment’s evolution. Samples of applications
that require self-adaptation include Smart home systems and environmental monitoring.
However, self-adaptivity is often constructed in an ad-hoc manner.

Methods:

In this paper, the authors present a pattern-based specification language for self-adaptive systems.
Its semantics are presented in terms of fuzzy logic. Thus, enabling a meticulous processing of requirements,
in order to permit the formulation of self-adaptive requirements accurately, thereby facilitates
the design of systems that are flexible and responsive to adaptation in a systematic manner.

Results:

To show the applicability and effectiveness of our language, the authors apply it to two
case studies. One case study reviews the Smart fridge in ambient assisted living and the second case
study is focused on an ambulance dispatching system using a developed support tool.
Unit Template Based Control of PV-DSTATCOM
Authors: Varshney Gunjan , Chauhan Durg S. , Dave Madhukar P. , Nitin
Published: October 2018

Background:

In modern electrical power distribution systems, Power Quality has become
an important concern due to the escalating use of automatic, microprocessor and microcontroller
based end user applications.

Methods:

In this paper, power quality improvement has done using Photovoltaic based Distribution
Static Compensator (PV-DSTATCOM). Complete simulation modelling and control of Photovoltaic
based Distribution Static Compensator have been provided in the presented paper. In this configuration,
DSTATCOM is fed by solar photovoltaic array and PV module is also helpful to maintain the DC
link voltage. The switching of PV-STATCOM is controlled by Unit template based control theory.

Results:

The performance of PV-DSTATCOM has been evaluated for Unity Power Factor (UPF)
and AC Voltage Control (ACVC) modes. Here, for studying the power quality issues three-phase
distribution system is considered and results have been verified through simulation based on
MATLAB software.

Conclusion:

Different power quality issues and their improvement are studied and presented here
for harmonic reduction, DC voltage regulation and power factor correction.
XXII Международный симпозиум Нанофизика и наноэлектроника", Нижний Новгород, 12-15 марта 2018 г. Расчет состояний многозарядных примесно-дефектных центров в эпитаксиальных слоях Hg-=SUB=-1-x-=/SUB=-Cd-=SUB=-x-=/SUB=-Te
Authors: Козлов Д.В. , Румянцев В.В. , Морозов С.В. , Кадыков А.М. , Фадеев М.А. , Hubers H.-W. , Гавриленко В.И.
Published: October 2018

AbstractA method for calculating the states of multivalent donors and acceptors in Hg_1 –_ x Cd_ x Te materials is developed. The ionization energies of deep acceptor and donor centers in epitaxial Hg_1 –_ x Cd_ x Te films are calculated. The calculation method takes into account the influence of both the valence band and the conduction band on the states of impurity-defect centers. The calculations of energies for the levels of tetravalent acceptors and donors associated with crystalline structure defects indicate the intercenter nature of lines observed previously in the photoluminescence spectra of Hg_1 –_ x Cd_ x Te films.
Влияние особенностей зонного спектра на характеристики стимулированного излучения в узкозонных гетероструктурах с квантовыми ямами на основе HgCdTe
Authors: Румянцев В.В. , Куликов Н.С. , Кадыков А.М. , Фадеев М.А. , Иконников А.В. , Казаков А.С. , Жолудев М.С. , Алешкин В.Я. , Уточкин В.В. , Михайлов Н.Н. , Дворецкий С.А. , Морозов С.В. , Гавриленко В.И.
Published: October 2018

AbstractWe report on the stimulated emission obtained in the wavelength range of 20.3–17.4 μm on the interband transitions at T = 8–50 K in HgCdTe quantum wells placed in a dielectric waveguide formed from wide-gap CdHgTe solid solution. Heterostructures with HgCdTe quantum wells are interesting for designing long-wavelength lasers operating in the wavelength range of 25–60 μm, which is not covered by currently available quantum cascade lasers. It is shown that the maximum temperature of stimulated emission is determined by the position of lateral maxima in the dispersion dependences in the first valence subband of the quantum well. Methods for suppressing nonradiative recombination in the structures with HgCdTe quantum wells are discussed.
Магнитооптика квантовых ям на основе HgTe/CdTe с гигантским расщеплением Рашбы в магнитных полях до 34 Тл
Authors: Бовкун Л.С. , Маремьянин К.В. , Иконников А.В. , Спирин К.Е. , Алешкин В.Я. , Potemski M. , Piot B. , Orlita M. , Михайлов Н.Н. , Дворецкий С.А. , Гавриленко В.И.
Published: October 2018

AbstractThe electron cyclotron resonance spectra in classical and quantizing magnetic fields in asymmetric heterostructures with HgCdTe/CdHgTe quantum wells with selective barrier doping are investigated. Self-consistent calculations of the energy spectra at B = 0 and Landau levels in the framework of the 8-band Kane model using the Hartree approximation are made. The strong (~10%) splitting of the cyclotron resonance line observed in weak fields is attributed to the Rashba effect in samples with inverted and normal band structures. The evolution of absorption lines upon a variation in the magnetic field is investigated up to 34 T, when the magnetic quantization already dominates over Rashba splitting.
Модель петли экстремумов" для спектра валентной зоны квантовой ямы HgTe/HgCdTe с инвертированной зонной структурой в полуметаллической фазе
Authors: Гудина С.В. , Боголюбский А.С. , Неверов В.Н. , Шелушинина Н.Г. , Якунин М.В.
Published: October 2018

AbstractThe effective mass and spectrum of Landau levels are calculated for the valence band of a HgTe/HgCdTe quantum well with an inverted band structure in the quasi-classical “extremum loop” model. The Landau-level fan of the valence band in the semimetallic phase starts at B = 0 from the energy corresponding to that of the lateral maxima of this band and is overlapped with the Landau-level fan of the conduction band.
Нитевидные нанокристаллы на основе фосфидных соединений, полученные методом молекулярно-пучковой эпитаксии на поверхности кремния
Authors: Цырлин Г.Э. , Резник Р.Р. , Самсоненко Ю.Б. , Хребтов А.И. , Котляр К.П. , Илькив И.В. , Сошников И.П. , Кириленко Д.А. , Крыжановская Н.В.
Published: October 2018

AbstractData on the growth and physical properties of nanostructures of the type “InAsP insert embedded in InP nanowire (NW)” grown on Si (111) surfaces by Au-assisted molecular-beam epitaxy are presented. It is found that nearly 100%-coherent NWs can be grown with a widely varying surface density. A relationship between the optical and structural properties of the NWs is revealed. It is shown that the NWs under study are formed of a purely wurtzite phase. The suggested technology opens up new opportunities for the integration of direct-gap III–V materials and silicon.
Экспериментальное исследование усиления спонтанной эмиссии в микрорезонаторах на основе таммовских плазмонов с органической активной областью
Authors: Морозов К.М. , Иванов К.А. , Selenin N. , Mikhrin S. , de Sa Pereira D. , Menelaou C. , Monkman A.P. , Калитеевский М.А.
Published: October 2018

AbstractSpontaneous-emission enhancement in a Tamm plasmon microcavity with an active region with organic material 4.4'-bis( N -carbazolyl)-1.1'-biphenyl (CBP) is theoretically and experimentally studied. The microcavity consisted of a Bragg reflector made of silicon oxide and tantalum oxide, over which CBP and silver layers are applied. The dependences of the Purcell modal factor on the emission direction and frequency, as well as the Purcell factor spectrum are calculated. The emission and fluorescence decay spectra in time are measured in the ultraviolet range. It is found that the probability of spontaneous emission increases and the maximum Purcell factor reaches three at frequencies corresponding to eigenmodes of the Tamm plasmon.
Зарождение трехмерных островков Ge на структурированной поверхности Si(100)
Authors: Рудин С.А. , Смагина Ж.В. , Зиновьев В.А. , Новиков П.Л. , Ненашев А.В. , Родякина Е.Е. , Двуреченский А.В.
Published: October 2018

AbstractThe nucleation of three-dimentional Ge islands formed on a pre-patterned Si substrate with an array of round pits is studied. It is found that the Ge islands nucleate within pits with pointed bottoms and along the perimeters of pits with flat bottoms. This effect is determined by the difference between the distributions of elastic strains at the Ge/Si interface for differently shaped pit bottoms. The results of the simulation of growth show that, in the case of pits with pointed bottoms, the most relaxed regions are at the centers of the pit bottoms and the nucleation of islands takes place just in these regions. At the same time, in the case of pits with flat bottoms, the most relaxed regions are shifted from the pit bottoms to the pit edges, resulting in the nucleation of islands along the pit perimeters.
Плазмохимическое травление арсенида галлия в индуктивно-связанной плазме C-=SUB=-2-=/SUB=-F-=SUB=-5-=/SUB=-Cl
Authors: Охапкин А.И. , Юнин П.А. , Дроздов М.Н. , Краев С.А. , Скороходов Е.В. , Шашкин В.И.
Published: October 2018

AbstractThe plasma chemical etching of gallium arsenide in chloropentafluoroethane (C_2F_5Cl) inductively coupled plasma is for the first time performed taking into account surface passivation by products of reagent decomposition. The elemental composition of deposited layers, their density, and morphological properties are studied. It is established that the smoothest etching profile is implemented when using a large freon flow and low capacitive power. Etching anisotropy is retained in such a mode at a depth of 7 μm with an etching rate of 230 nm/min.
Гетероструктуры с InAs/AlAs квантовыми ямами и квантовыми точками, выращенные на гибридных подложках GaAs/Si
Authors: Абрамкин Д.С. , Петрушков М.О. , Путято М.А. , Семягин Б.Р. , Шамирзаев Т.С.
Published: October 2018

AbstractHeterostructures with InAs/AlAs quantum dots are grown on GaAs/Si hybrid substrates. The experimentally observed low-temperature (5–80 K) photoluminescence spectra of InAs/AlAs/GaAs/Si heterostructures exhibit bands defined by excitonic recombination in quantum dots and a wetting layer, i.e., a thin quantum well lying at the base of the array of quantum dots. Temperature quenching of the photoluminescence of quantum dots occurs due to the direct trapping of charge carriers at defects localized in the AlAs matrix, in the vicinity of the quantum dots.
Стимулированное излучение в диапазоне 1.3-1.5 мкм из квантовых ям AlGaInAs в гибридных светоизлучающих структурах A-=SUP=-III-=/SUP=-B-=SUP=-V-=/SUP=- на кремниевых подложках
Authors: Кудрявцев К.Е. , Дубинов А.А. , Алешкин В.Я. , Юрасов Д.В. , Горлачук П.В. , Рябоштан Ю.Л. , Мармалюк А.А. , Новиков А.В. , Красильник З.Ф.
Published: October 2018

AbstractHybrid laser structures with AlGaInAs quantum wells are grown by metalorganic vapor phase epitaxy on Ge/Si(100) “virtual” substrates using GaAs and InP buffer layers. Stimulated emission is achieved under optical pumping of the prepared samples in the range of 1.3–1.5 μm at liquid-nitrogen temperature. The stimulated-emission threshold is 30–70 kW/cm^2.
Квантовая динамика заряда в квазиодномерных сверхпроводниках
Authors: Лехтинен Я.С. , Львов Б.Г. , Арутюнов К.Ю.
Published: October 2018

Abstract —Volt-ampere characteristics of narrow superconducting titanum wires have been studied experimentally. The narrowest specimens measured by means of high-resistance contacts have revealed a behavior nontrivial for superconductors: the Coulomb blockade. The Coulomb gap size correlates with the frequency of quantum phase slips. The observation confirms the identity of quantum dynamics of charge in the Josephson junctions and in the quasi-one-dimensional superconducting channels in the regime of quantum fluctuations of the order parameter.
Конденсация (псевдо)магнонов в двумерной анизотропной S=1 (псевдо)спиновой системе
Authors: Васинович Е.В. , Москвин А.С. , Панов Ю.Д.
Published: October 2018

Abstract —A 2D anisotropic system of S = 1 centers of the charge triplet type in systems with variable valence or “semi-hard-core” boson systems with a limitation for the occupation of lattice sites n = 0, 1, 2 is studied in the framework of the pseudospin formalism. Assuming that the ground state is a quantum paramagnet, the pseudo-spin wave spectrum and also the conditions of the condensation of pseudomagnons with a phase transition to a superconducting state have been found using the Schwinger boson method.
Особенности нелинейного СВЧ-отклика многозонных сверхпроводников на основе ферроселенида натрия-калия (Na-=SUB=-0.3-=/SUB=-K-=SUB=-0.7-=/SUB=-)-=SUB=-x-=/SUB=-Fe-=SUB=-2-y-=/SUB=-Se-=SUB=-2-=/SUB=-
Authors: Пестов Е.Е. , Ноздрин Ю.Н. , Елькина А.И. , Ерин Ю.C. , Лю М. , Болталин А.И. , Морозов И.В.
Published: October 2018

Abstract —Temperature dependences of the third-harmonic power for the (Na_0.3K_0.7)_ x Fe_2 – _ y Se_2 sodium–potassium ferroselenide single crystals have been investigated by nonlinear near-field microwave microscopy. The temperature dependence of magnetic susceptibility at a frequency of 100 kHz for this compound has been measured. The experimental results suggest a double-gap structure of the (Na_0.3K_0.7)_ x Fe_2 – _ y Se_2 superconductor.
Изучение процесса перемагничивания пермаллоевых микрочастиц с конфигурационной анизотропией методами магнитно-силовой микроскопии
Authors: Бизяев Д.А. , Бухараев А.А. , Чукланов А.П. , Нургазизов Н.И.
Published: October 2018

Abstract —Magnetic force microscopy has been used to study the distribution of the magnetization in permalloy microparticles with a configurational anisotropy. The triangular particles with different degrees of concavity of the lateral sides have been studied. An analysis of the results enables us to state that the particles can be in several quasi-homogeneous stable states. It is shown that the particle magnetization reversal can occur both stepwise and also via an intermediate state in the dependence on the particle orientation. It is demonstrated that the quasi-homogeneous magnetization orientation in a particle can be changed by a magnetic-force microscope probe.
Формирование доменной структуры в многослойных пленках CoPt с помощью магнитного зонда атомно-силового микроскопа
Authors: Темирязев А.Г. , Темирязева М.П. , Здоровейщев А.В. , Вихрова О.В. , Дорохин М.В. , Демина П.Б. , Кудрин А.В.
Published: October 2018

Abstract —A possibility of changing the magnetic type structure of multilayer CoPt films under action of the magnetic field of the atomic force microscope probe is demonstrated. A new method of non-contact magnetic-force measurements based on artificial increase in the electrostatic interaction between the probe and the film is proposed. This method enables one to controllably change the distance between a probe and a film, thus changing the strength of the magnetic interaction. Using it, one can create from a uniformly magnetized state both a labyrinth domain structure and isolated domains, which are apparently magnetic skyrmions.
Магнитооптические свойства висмутзамещенных пленок ферритов-гранатов в сильных импульсных магнитных полях
Authors: Кудасов Ю.Б. , Логунов М.В. , Козабаранов Р.В. , Макаров И.В. , Платонов В.В. , Сурдин О.М. , Маслов Д.А. , Коршунов А.С. , Попов E.Я. , Светлов А.С.
Published: October 2018

Abstract —A technique of measuring the rotation of the light polarization plane in pulsed magnetic fields with strength up to 40 T with a sensitivity of  0.1° is proposed. The Faraday effect has been studied in films of diluted ferrites—garnets (Lu,Bi)_3(Fe,Ga,Al)_5O_12 in the temperature range from room temperature to 78 K, including the vicinity of the magnetic moment compensation temperature. The transition to the noncollinear phase in the magnetic phase diagram is shown to occur at a magnetic field strength higher than 30 T at room temperature, and the threshold transition field tends to zero when approaching the magnetic moment compensation temperature.
Ферромагнитный резонанс в квадратных решетках планарных магнитных элементов крестообразной формы
Authors: Горев Р.В. , Сапожников М.В. , Миронов В.Л.
Published: October 2018

Abstract —Ferromagnetic resonance (FMR) in planar thin film structures comprised of magnetic cross-shaped elements arranged into square lattices has been studied by micromagnetic simulation. FMR spectra and spatial distributions of amplitudes of resonant oscillations were determined for vortex and antivortex states of magnetization in lattice crosses. Resonant modes have the shape of rotating magnetization distributions. Herewith, modes with the same configuration of magnetization but rotating in reverse directions are frequency split. The observed nonreciprocity of propagation of resonant spin oscillations is determined by the sign of magnetization distribution vorticity.