bluuebunny/crossref_metadata_2025 huggingface dataset:
Recommendations for the Proper Handling of Cores and Sedimentological Analysis of Core Sequences
Authors: Siemers Charles T. , Tillman Roderick W.
Published: January 2014

The detailed sedimentological analysis of whole-diameter cores is greatly enhanced by the core being in good condition; ideally, cores should be complete (100% recovery) and well labeled with all pieces in correct order. Considerable information loss occurs when cores are mishandled; therefore, specific procedures should be followed. At the well site care should be exercised to preserve correct orientation of individual core segments and the core should be properly marked. Hügel orientation grooves cut in the core will facilitate core reconstruction. Commercial core analysis laboratories usually generate the greatest amount of information loss; therefore, special care should be used during subsampling for fluid-saturation analyses and porosity-permeability measurements. A core gamma-ray scan should be obtained whenever possible to aid in later core-to-log correlation. Finally, prior to detailed examination, it is recommended that the core be slabbed, lapped and photographed. X-ray radiography may be needed to enhance subtle sedimentary structures in massive-appearing sandstones and mudrocks.

For proper sedimentological core analysis we recommend a process-sedimentology approach which emphasizes detailed lithologic description and the recognition of genetic units within the vertical sequence. A continuous, detailed sketch should be made and a description made using a check list of important lithologic features. An understanding of Walther’s Law is required for maximum use of the vertical sequence. At least four types of genetic units can be delineated to interprete the physical, biological and chemical processes responsible for generating the sedimentary rock product of the core. Those types are: sedimentation unit, ichnogenetic unit, soft-sediment-deformation (s-s-d) unit, and diagenetic unit.

Finally, the sedimentological core analysis should be used to calibrate the wire-line logs and associated sursurface data. The main steps in such calibration are to first determine the core-to-log depth correction and then to determine the level at which genetic units and lithofacies can be recognized on the logs. Such calibration leads to better correlation of sedimentological information to nearby non-cored wells and allows for lateral extension of predictive sedimentological models throughout the subsurface study area.
Submarine-Fan Deposition of the Upper Cretaceous Winters Sandstone, Union Island Gas Field, Sacramento Valley, California
Authors: Williamson Charles R. , Hill David R.
Published: January 2014

Thick-bedded, massive Winters sandstones are the principal reservoir facies of the Union Island gas field in the southern Sacramento Valley. The field is a structural-stratigraphic trap set up by structural closure against the Stockton Arch fault and by facies changes within the Winters Sandstone. Since the discovery of the field by Union Oil in early 1972, total gas production has been approximately 90,000,000 MCF from 16 wells.

Three major facies are recognized in the nearly 190 feet of conventional cores taken from four development wells in the field: (1) thick-bedded, porous (20 to 30%) massive sandstone, (2) inter-bedded thin sandstone and shale, and (3) laminated shale. Features in the cores as well as seismic, paleontologic, and regional subsurface data indicate a deep-water (bathyal) origin for the Winters Sandstone. X-radiographs of apparently “structureless”, massive sandstones at Union Island field exhibit horizontal or cross stratification in approximately 50% of the intervals examined. The stratification and other structures suggest that the massive sandstones as well as the thinner bedded sandstones were deposited by turbidity currents.

The Winters sandstones at Union Island field commonly show upward-fining and upward-thinning sequences, are elongate perpendicular to the depositional slope, and thicken toward the basin. They are interpreted to be coalesced channel deposits which formed at the base of the slope on the upper part of a sandy suprafan. Thinly interbedded sandstone and shale that separates the massive sandstones represents channel-abandonment and interchannel-overbank deposits.
Cleaning and regeneration of periphyton biofilm in surface water treatment systems
Authors: Wu Yonghong , Xia Lizhong , Liu Nian , Gou Shuai , Nath Bibhash
Published: January 2014

The fouling of periphyton biofilm is a common problem associated with surface water treatment systems. In this study, sulfuric acid (H2SO4), sodium acetate (CH3COONa) and ethylenediamine tetra-acetic acid (EDTA) solutions were sequentially used to clean periphyton biofilms collected from a surface water treatment system. The results showed that the sequential addition of H2SO4 and CH3COONa solutions could accelerate the exfoliation of the fouled periphyton biofilm, while the addition of EDTA solution could regenerate the periphyton biofilm. However, the addition of H2SO4 and CH3COONa solution might negatively affect the bacterial community structure, while the addition of EDTA solution facilitated improvement of the community structure. The combined effect of cleaning and regeneration of periphyton biofilm has significantly improved the removal efficiencies of chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN) and ammonia (NH4-N), by 19, 20, 23 and 22%, respectively. The removal processes of COD, TP, TN and NH4-N by the cleaned biofilm were fitted to power regression curves, while those by the control biofilm during the removal process were fitted to polynomial regression curves. These systemic results indicate that the sequential addition of H2SO4, CH3COONa and EDTA solution is able to clean fouled periphyton biofilm and to enhance the efficiency of surface water treatment systems.
Lamella settlers for storm water treatment – performance and design recommendations
Authors: Fuchs Stephan , Mayer Ingo , Haller Bernd , Roth Hartmut
Published: January 2014

Three lamella settlers were monitored over a period of 4 years. The main objective was to determine removal efficiencies for total suspended solids and associated pollutants. For this purpose a new sampling method based on large volume solid samplers was developed allowing a detailed analysis of solids. With regard to total suspended solids the average removal efficiency of the plants range from 49 to 68%. Similar values could be achieved for phosphorus and heavy metals mainly because of the high portion of fine particles in treatment plants' influent. A clear dependency between solid removal efficiency and the parameters maximum surface load and influent concentration could be observed on a single event basis. The aggregation of all findings result in a recommended maximum design surface loading rate (SLR) of 4 m/h. A solid removal rate of 50%, which is defined as minimum long-term efficiency, can be achieved safely at this SLR. In addition to the definition of the maximum SLR, a proper dissipation of the inflow energy and an equal collection of the clear water above the lamellas turn out to be essential.
Sensitive quantification of trace zinc in water samples by adsorptive stripping voltammetry
Authors: Abbasi Shahryar , Farmany Abbas , Roushani Mahmoud , Mortazavi Seyede Shima
Published: January 2014

A simple and sensitive adsorptive stripping voltammetry method was developed for determination of Zn using N-nitrozo-N-phenylhydroxylamine (cupferron) as a selective complexing agent. This complex absorbed on the hanging mercury drop electrode and created a sensitive peak current. The peak current and concentration of zinc accorded with a linear relationship in the range of 0.85–320 ng mL−1. The influence of pH and the nature of supporting electrolytes, concentration of ligand, preconcentration time and applied potential were investigated. The relative standard deviation at a concentration level of 50 ng mL−1 was 1.8%. The method was applied to the determination of zinc in city, river and mineral water samples, with satisfactory results.
Simulation of landfill leachate treatment using electro-Fenton technique
Authors: Davarnejad Reza , Moraveji Mostafa Keshavarz , Pirhadi Masoud , Mohammadi Mohsen
Published: January 2014

The operating parameters in the electro-Fenton process were simulated using computational fluid dynamics (CFD). The effects of H2O2/Fe2+ molar ratio, current density, pH and reaction time were numerically investigated. The results were compared with the experimental data. The simulated data showed that maximum chemical oxygen demand (COD) removal was around 91.52% at pH of 3.27, H2O2/Fe2+ molar ratio of 1.16, current density of 59.29 mA/cm2 and reaction time of 41.7 min while the experimental data obtained from the literature showed a maximum COD removal (94.7%) at pH of 3, H2O2/Fe2+ molar ratio of 1, current density of 49 mA/cm2 and reaction time of 43 min.
The effect of aeration and effluent recycling on domestic wastewater treatment in a pilot-plant system of duckweed ponds
Authors: Ben-shalom Miriam , Shandalov Semion , Brenner Asher , Oron Gideon
Published: January 2014

Three pilot-scale duckweed pond (DP) wastewater treatment systems were designed and operated to examine the effect of aeration and effluent recycling on treatment efficiency. Each system consisted of two DPs in series fed by pre-settled domestic sewage. The first system (duckweed+ conventional treatment) was ‘natural’ and included only duckweed plants. The second system (duckweed aeration) included aeration in the second pond. The third system (duckweed+ aeration+ circulation) included aeration in the second pond and effluent recycling from the second to the first pond. All three systems demonstrated similarly efficient removal of organic matter and nutrients. Supplemental aeration had no effect on either dissolved oxygen levels or on pollutant removal efficiencies. Although recycling had almost no influence on nutrient removal efficiencies, it had a positive impact on chemical oxygen demand and total suspended solids removals due to equalization of load and pH, which suppressed algae growth. Recycling also improved the appearance and growth rate of the duckweed plants, especially during heavy wastewater loads.
Effect of Aqueous Extract of Giant Horsetail (Equisetum giganteum L.) in Antigen-Induced Arthritis
Authors: Farinon Mirian , Lora Priscila Schmidt , Francescato Leandro Nicolodi , Bassani Valquiria Linck , Henriques AmÉlia Teresinha , Xavier Ricardo Machado , Oliveira Patricia Gnieslaw de
Published: January 2014

Equisetum giganteum is a plant used in traditional medicine as diuretic. From our knowledge this is the first
time this plant is tested in an in vivo model of acute inflammation. To evaluate the effect of aqueous extract of giant
horsetail (AEGH) as immunomodulatory therapy, antigen-induced arthritis (AIA) was generated in mice with methylated
bovine serum albumin (mBSA). Inflammation was evaluated by articular nociception, leukocytes migration and
lymphocyte proliferation. AEGH reduced nociception at 3, 6 and 24 h (P < 0.01), decreased leukocyte migration (P <
0.015), and inhibited lymphocyte proliferation stimulated with Concanavalin A and Lipopolysaccharide (P < 0.05). In
conclusion, AEGH has an anti-inflammatory potential in acute model of inflammation, as well as immunomodulatory
effect on both B and T lymphocytes, with an action independent of cytotoxicity.
Improvements in Biosolids Quality Resulting from the Clean Water Act
Authors: Hundal Lakhwinder S. , Kumar Kuldip , Cox Albert , Zhang Heng , Granato Thomas
Published: January 2014

Promulgation of the Clean Water Act (CWA) authorized the United States Environmental Protection Agency (U.S. EPA) to regulate quality standards for surface waters and establish regulations limiting the amounts and types of pollutants entering the nation's waters. U.S. EPA imposed national pretreatment standards on industrial wastes discharged to the collection systems of publicly owned treatment works (POTWs) and promulgated General Pretreatment Regulations in 1978. This study analyzed trace metals data from the National Sewage Sludge Surveys conducted by U.S. EPA and the American Metropolitan Sewage Agencies (AMSA) to evaluate the effect of implementation of the national industrial pretreatment standards on concentrations of trace metals in sludges generated by POTWs in the United States. The data showed that implementation of pretreatment programs has been highly effective in reducing the amount of pollutants that enter POTWs and has resulted in a substantial reduction in the levels of trace metals in the municipal sludges. Concentrations of chromium, lead, and nickel in sludge declined by 78, 73, and 63%, respectively, within a year after promulgation of General Pretreatment Regulations. Resulting from these measures, metal concentrations in the sludges generated by a majority of POTWs in the United States are sufficiently low that the sludges can be classified as biosolids and also meet the U.S. EPA's exceptional quality criteria for trace metals in biosolids. This improvement gives POTWs the option to use their biosolids beneficially through land application.
Adsorption/Oxidation of Arsenic in Groundwater by Nanoscale Fe‐Mn Binary Oxides Loaded on Zeolite
Authors: Kong Shuqiong , Wang Yanxin , Zhan Hongbin , Yuan Songhu , Yu Mei , Liu Mingliang
Published: January 2014

Nanoscale Fe‐Mn binary oxides loaded on zeolite (NIMZ) is synthesized and characterized. The as‐synthesized adsorbent is amorphous with 126 m2/g surface area; it is effective for the adsorption of both As(III) and As(V) in synthetic groundwater. It has high adsorption capacities of 296.23 and 201.10 mg/g for As(III) and As(V), respectively. For the adsorption of 2 mg/L arsenic, the aqueous concentration quickly decreases to less than 10 μg/L within 30 min. During the adsorption of As(III), the in‐aqueous measurement of As(V) shows a low concentration in the initial stage and disappears afterward. The fraction of As(V) on NIMZ gradually increases with time, proving the oxidation of As(III). The adsorption of As(III) and As(V) decreases with increasing pH. The anions of,, and significantly compete with arsenic for the adsorption sites. The inner‐sphere surface complexes are formed by As(III) or As(V) with the hydroxyl groups on the surface of NIMZ.
Hot-probe method for evaluation of majority charged carriers concentration in semiconductor thin films
Authors: Axelevitch Alexander , Golan Gady
Published: January 2014

Physical properties of thin films significantly differ from those of bulk
materials. Also, these properties are influenced from the technological
parameters of the films deposition technique. Therefore, characterization
methods for evaluation of thin film properties become of high importance. A
novel approach to the well-known "Hot-Probe" method is proposed and applied
in our work. The conventional Hot Probe characterization method enables only
the definition of a semiconductor type, P or N, by identifying the majority
of the charged carriers. According to the new Hot Probe technique, one can
measure and calculate the impurities concentration and charged carriers
dynamic parameters. Feasibility proof of the upgraded Hot Probe method was
done in Si and Ge bulk, and in thin film semiconductor samples of In2O3 and
VO2.
Review on double-gate MOSFETs and FinFETs modeling
Authors: Cerdeira A. , Estrada M. , Alvarado J. , Garduño I. , Contreras E. , Tinoco J. , Iñiguez B. , Kilchytska V. , Flandre D.
Published: January 2014

The development of compact models for double-gate (DG) MOSFETs and FinFETs
necessary in circuit simulators is an important research field, which allows
the efficient practical characterization of these devices, as well as their
application in analog circuit design. In this paper we review and assess
different approaches for developing core and complete compact models for DG
MOSFETs and FinFETs.
Multiple purpose spin transfer torque operated devices
Authors: Windbacher Thomas , Mahmoudi Hiwa , Makarov Alexander , Sverdlov Viktor , Selberherr Siegfried
Published: January 2014

We summarize our recent work on a non-volatile logic building block required
for energy-efficient information processing systems. A sequential logic
device, in particular, an alternative non-volatile magnetic flip-flop has
been introduced. Its properties are investigated and its extension to a very
dense shift register is demonstrated. We show that the flip-flop structure
inherently exhibits oscillations and discuss its spin torque nano-oscillator
properties.
Numerical simulation of gas-solid flow in an interconnected fluidized bed
Authors: Canneto Giuseppe , Freda Cesare , Braccio Giacobbe
Published: January 2014

The gas-particles flow in an interconnected bubbling fluidized cold model is
simulated using a commercial CFD package by Ansys. Conservation equations of
mass and momentum are solved using the Eulerian granular multiphase model.
Bubbles formation and their paths are analyzed to investigate the behaviour
of the bed at different gas velocities. Experimental tests, carried out by
the cold model, are compared with simulation runs to study the fluidization
quality and to estimate the circulation of solid particles in the bed.
Thermal properties of flax fiber scoured by different methods
Authors: Zheng Dong , Ding Ruo-Yao , Lei Zheng , Xingqun Zhang , Chong-Wen Yu
Published: January 2014

Thermal properties of flax roves untreated and treated were characterized by
differential scanning calorimetry (DSC) and thermal gravity analyzer (TGA)
in order to understand their thermal behavior in more detail and to evaluate
the effect of scouring processing on the thermal behavior. Flax roves were
treated with six kinds of methods including biological scouring, one bath,
two bath, bleaching, alkali scouring and industry chemical scouring as
standards. Results showed that all treatments improved thermal stability of
flax roves. The results indicated that glass transition temperature (Tg)
decreased after scouring besides the sample by directly bleaching. It is
more difficult to determine the endothermic peak of flax treated by chemical
scouring in industry because it takes a very flat course. A distinct
endothermic peak was observed for the untreated flax rove, while a distinct
exothermic peak in different temperature interval was revealed for other
four treated flax rove samples. For TGA analysis, thermal degradation of
flax roves studied consists of three regions of the initial, main, and char
decomposition, and the third stage consists of secondary weight loss and
carbonization for flax roves with biological scouring, one-bath and
two-bath. Besides, different residue left indicates that the bio-scoured
flax roves are lost with volatile products and does not contribute to char
formation. These results provide valuable preferences for mechanism and top
value added application of bio-scouring in flax roves.
Impact of physical properties of mixture of diesel and biodiesel fuels on hydrodynamic characteristics of fuel injection system
Authors: Filipovic Ivan , Pikula Boran , Kepnik Goran
Published: January 2014

One of the alternative fuels, originating from renewable sources, is
biodiesel fuel, which is introduced in diesel engines without major
construction modifications on the engine. Biodiesel fuel, by its physical and
chemical properties, is different from diesel fuel. Therefore, it is expected
that by the application of a biodiesel fuel, the characteristic parameters of
the injection system will change. These parameters have a direct impact on
the process of fuel dispersion into the engine cylinder, and mixing with the
air, which results in an impact on the quality of the combustion process.
Method of preparation of the air-fuel mixture and the quality of the
combustion process directly affect the efficiency of the engine and the level
of pollutant emissions in the exhaust gas, which today is the most important
criterion for assessing the quality of the engine. The paper presents a
detailed analysis of the influence of physical properties of a mixture of
diesel and biodiesel fuels on the output characteristics of the fuel
injection system. The following parameters are shown: injection pressure,
injection rate, the beginning and duration of injection, transformation of
potential into kinetic energy of fuel and increase of energy losses in fuel
injection system of various mixtures of diesel and biodiesel fuels. For the
analysis of the results a self-developed computer program was used to
simulate the injection process in the system. Computational results are
verified using the experiment, for a few mixtures of diesel and biodiesel
fuels. This paper presents the verification results for diesel fuel and
biodiesel fuel in particular.
Correlation between the morphology of unheated staircase and energy performance of residential buildings
Authors: Rajcic Aleksandar , Radivojevic Ana , Elezovic Martin
Published: January 2014

As a side effect of the need for greater energy efficiency of buildings,
there is a problem of decrease of the available interior space affected by
the reduction in U-value of parts of thermal building envelope, i.e. an
increase in thickness of insulating layer, which is especially present in
unheated staircase. Having in mind that present methods of calculation of
transmission heat losses through elements of thermal envelope include the
adjustment factor which regulates designed temperature conditions if the
temperature at the colder side of the element of the thermal envelope differs
from that of the external environment, this paper strives to demonstrate that
in the case of unheated staircases, this fixed value should be reconsidered
and treated as a variable depending on the morphology, i.e. form, size and
position of the staircase within the building. This problem has been analyzed
on the example of Serbian housing stock and relevant national thermal
regulations. Three morphological types of unheated staircases have been
distinguished within which three models have been defined and examined with
respect to variations in number of floors and percentage of glazing. Average
temperatures of staircase volume and temperature correction factors were
calculated in following temperature modes: stationary that excluded solar
gains and ventilation heat losses and gains, and dynamic with variations in
air exchange rates and insolation conditions, expressing in all of the cases
variations in calculated values of temperature correction factors in
comparison to the prescribed fixed value.
Analysis of combustion performance and emission of extended expansion cycle and iEGR for low heat rejection turbocharged direct injection diesel engines
Authors: Shabir Mohd , Prasath Rajendra , Tamilporai P.
Published: January 2014

Increasing thermal efficiency in diesel engines through low heat rejection
concept is a feasible technique. In LHR engines the high heat evolution is
achieved by insulating the combustion chamber surfaces and coolant side of
the cylinder with partially stabilized zirconia of 0.5 mm thickness and the
effective utilization of this heat depend on the engine design and operating
conditions. To make the LHR engines more suitable for automobile and
stationary applications, the extended expansion was introduced by modifying
the inlet cam for late closing of intake valve through Miller?s cycle for
extended expansion. Through the extended expansion concept the actual work
done increases, exhaust blow-down loss reduced and the thermal efficiency of
the LHR engine is improved. In LHR engines, the formation of nitric oxide is
more, to reduce the nitric oxide emission, the internal EGR is incorporated
using modified exhaust cam with secondary lobe. Modifications of gas exchange
with internal EGR resulted in decrease in nitric oxide emissions. In this
work, the parametric studies were carried out both theoretically and
experimentally. The combustion, performance and emission parameters were
studied and were found to be satisfactory.
Diminished Adenosine A1 Receptor Expression in Pancreatic α-Cells May Contribute to the Pathology of Type 1 Diabetes
Authors: Yip Linda , Taylor Cariel , Whiting Chan C. , Fathman C. Garrison
Published: January 2014

Prediabetic NOD mice exhibit hyperglucagonemia, possibly due to an intrinsic α-cell defect. Here, we show that the expression of a potential glucagon inhibitor, the adenosine A1 receptor (Adora1), is gradually diminished in α-cells of NOD mice, autoantibody-positive (AA+) and overtly type 1 diabetic (T1D) patients during the progression of disease. We demonstrated that islet inflammation was associated with loss of Adora1 expression through the alternative splicing of Adora1. Expression of the spliced variant (Adora1-Var) was upregulated in the pancreas of 12-week-old NOD versus age-matched NOD.B10 (non–diabetes-susceptible) control mice and was detected in the pancreas of AA+ patients but not in control subjects or overtly diabetic patients, suggesting that inflammation drives the splicing of Adora1. We subsequently demonstrated that Adora1-Var expression was upregulated in the islets of NOD.B10 mice after exposure to inflammatory cytokines and in the pancreas of NOD.SCID mice after adoptive transfer of activated autologous splenocytes. Adora1-Var encodes a dominant-negative N-terminal truncated isoform of Adora1. The splicing of Adora1 and loss of Adora1 expression on α-cells may explain the hyperglucagonemia observed in prediabetic NOD mice and may contribute to the pathogenesis of human T1D and NOD disease.
Nifedipine bağlı dişeti büyümesi: Olgu sunumu
Authors: Tan Makbule Neslişah , Yıldırım Ediz
Published: January 2014

Nifedipin, stabil anjina pektoris ve hipertansiyon tedavisinde kullanılan kalsiyum kanal blokörüdür. ılaca bağlı dişeti büyümesine neden olabilir. Bu çalışlmada; nifedipin kullanımına bağlı dişeti büyümesi şikayetiyle kliniğe başvuran bir olgu sunulmaktadır. Olguda, büyüyen dişeti dokularında cerrahi tedaviye gerek kalmadan, nifedipin kesilerek ve ağız hijyeni eğitimi verilerek yeterli iyileşme sağlanmştır.
DECOMPOSITIONS OF CONTINUITY IN IDEAL TOPOLOGICAL SPACES
Authors: Al-Omari Ahmad , Noiri Takashi
Published: January 2014

In this paper, we define new classes of sets called preopen sets, θI-semi-open sets, θI-β-open sets and θI-α-open sets in ideal topological spaces. Also, by using these sets, we obtain new decompositions of continuity in ideal topological spaces.
Problems Examination in Quality Management System
Authors: Ligarski Mariusz J.
Published: January 2014

In the work, there was a method of problems examination presented in the certified quality management system according to the ISO 9001 standard. The own method of problems examination was suggested on the basis of reports from audits of the third party. There are method assumptions as well as practical application presented for the examination of nonconformities and weaknesses on a sample of 892 organizations certified by a chosen certifying body. Different types of compilations of obtained results are showed. Different possibilities of their application for the examination of relations of identified problems were indicated, depending on the size and profile of examined organizations. Different types of statistical tests were used in the method together with their possibilities. Concrete examples of uses of the method and statistical tests were provided for examining the relations between the size as well as profile of the organization and the number as well as type of nonconformities and weaknesses. It was attempted to determine what possibilities the method provides and to give the examples of its practical use. Additionally, an attention was paid to potential difficulties when applying the method.
Do we have a chance for small-scale energy generation? The examples of technologies and devices for distributed energy systems in micro & small scale in Poland
Authors: Kiciński J.
Published: January 2014

This paper presents examples of technologies for distributed energy generation developed under the projects coordinated by the IFFM PAS in Gdańsk. These are CHP units (generating heat and electricity) for houses with a power from several to tens of kW and for municipalities in the form of the Municipal Energy Centers (with a capacity of several hundred kW up to several MW). A unique project, specializing in “energy-plus” technologies for residential houses and other buildings, which aims to build a Research Centre of PAS in Jabłonna is also presented,. These are key technologies for energy sector with respect to distributed generation.

Additionally, the article discusses the conditions and opportunities for the development of energy generation or more broadly: civic energy generation in our country. Civic energy generation is a great vision in which the citizen becomes an entity and do not subject to the energy market, and additionally has its virtual advisor in the form of smart grid and data processing technologies in a “digital cloud”.
Vector analysis of the current commutation in PM BLDC drives
Authors: Buja G. , Menis R. , Keshri R.
Published: January 2014

The vector approach in either stationary or synchronous plane is commonly used for the analysis of the AC drives like induction and PM brushless AC drives whilst it has been hardly ever used for the PM brushless DC (BLDC) drives. A possible reason is that they require injection of square-wave currents into the motor phases, which are non-sinusoidal in nature. Recently, the PM BLDC drives have been analyzed by the help of the vector approach in the stationary plane. This paper applies such an approach to an in-depth analysis of the operation of the PM BLDC drives during the current commutations, illustrating the potentialities of the approach in giving a better insight into the current transients and the ensuing torque characteristics. At last, two voltage control strategies proposed to eliminate the torque ripple due to the current commutations are considered, showing that they can be readily understood by the vector approach.
Active power filters – optimization of sizing and placement
Authors: Maciążek M. , Grabowski D. , Pasko M.
Published: January 2014

The significant problem of compensator placement and sizing in electrical networks has been analyzed in the paper. The compensation is usually realized by means of passive or active power filters. The former solution is widely used mainly because of the economical reasons, but the latter one becomes more and more popular as the number of nonlinear loads increases. Regardless of the compensator type the most important goal consists in voltage and current distortion drop below levels imposed by standards. Nevertheless, the desired effects should be achieved with the minimum cost. So far a few objective functions have been proposed for this optimization problem. It is claimed that minimization of the compensator currents leads also to the minimum costs. This paper shows that such simplified approach could lead to suboptimal solutions and in fact a function g(·) reflecting the relation between the compensator size and its price must be incorporated into objective functions. Moreover, in this case it is very easy to compare solutions obtained using compensators offered by different suppliers - it is enough to change the function g(·). Theoretical considerations have been illustrated by an example of active power filter allocation and sizing.
Experimental investigation and modelling of Friction Stir Processing of cast aluminium alloy AlSi9Mg
Authors: Węglowski M.S. , Dymek S. , Hamilton C.B.
Published: January 2014

Friction Stir Processing (FSP) is a novel solid state processing technique which can be used for microstructural modification of surface layers in metallic materials. This paper analyzes the effects of FSP process parameters on spindle torque acting on the tool and on the tool temperature. It has been shown that an increase in the rotational speed brings about a decrease in the torque and an increase of temperature. For temperature estimation in the stir zone a numerical model was applied, while for predicting a relationship between the spindle torque acting on the tool, rotational and travelling speeds and the down force, the artificial neural networks approach was employed. Light and electron (scanning and transmission) microscopy investigation showed that the FSP process reduces porosity and produces a more uniform distribution of second-phase particles.
A relaxation heuristic for scheduling flowshops with intermediate buffers
Authors: Magiera M.
Published: January 2014

The paper presents a two-level relaxation heuristic for production planning for multistage flowshop systems with intermediate buffers. The method concerns unidirectional multistage systems where tasks with respect to many various types of products are performed simultaneously. The fixed and the alternative production routes are regarded in the method. The top-level is a stage loading, i.e., allocation of tasks among the stages. The base-level is a task scheduling - allocation of tasks among the stations. The linear mathematical models of mixed integer programming are used in the method. The time criterion is used in the minimization functions - the minimal schedule is fixed. The condition that variables are to be integers has been ignored in the heuristic. The relaxed heuristic developed in such a manner enables obtaining good results in a very short time. This paper discusses the multilevel approach as the developed production scheduling method serves the purpose of solving relatively large problems. Results of computational experiments with the proposed heuristic method are presented.
Parallel computations of the step response of a floor heater with the use of a graphics processing unit. Part 2: results and their evaluation
Authors: Gołębiowski J. , Forenc J.
Published: January 2014

Using models and algorithms presented in the first part of the article, a spatio-temporal distribution of the step response of a floor heater was determined. The results have been presented in the form of heating curves and temperature profiles of the heater in the selected time moments. The computations results were verified through comparing them with the solution obtained with the use of a commercial program - NISA. Additionally, the distribution of the average time constant of thermal processes occurring in the heater was determined. The analysis of the use of a graphics processing unit in numerical computations based on the conjugate gradient method was done. It was proved that the use of a graphics processing unit is profitable in the case of solving linear systems of equations with dense coefficient matrices. In the case of a sparse matrix, the speed-up depends on the number of its non-zero elements.
The dynamics of the human arm with an observer for the capture of body motion parameters
Authors: Babiarz A. , Bieda R. , Jaskot K. , Klamka J.
Published: January 2014

The paper presents an analysis of a mathematical model of the human arm dynamics in terms of observability. The purpose of the performed experiments is the selection of an observer for the possibility of arm tracking. The arm model is based on the two-link manipulator moving horizontally and vertically. For the study a model was linearized and the model part responsible for the work of human muscles was omitted. The experimental part involved simulated measurements of the motion parameters that imitate real-IMU (Inertial Measurement Unit) measurements. Finally, the simulation results using the observer in the form of a Kalman filter and the particle filter have been presented.
Low power 9-bit pipelined A/D and 8-bit self-calibrated D/A converters for a DSP system
Authors: Wawryn K. , Suszynski R.
Published: January 2014

A low power, low voltage current mode 9 bit pipelined a/d converter and 8 bit self-calibrated d/a converter to interface a DSP system are presented in the paper. The a/d converter is built of 1.5 bit stages with digital error correction logic. The d/a converter is composed of 3 LSBs fine and 5 MSBs coarse current mode converters. The a/d and d/a converters were designed in 0.35 μm technology, then fabricated to verify the proposed concept. The performances of both converters are compared to the performances of known converter structures. The main advantages of the proposed converters are low power consumption and small chip area.
Quasi-analytic multidimensional signals
Authors: Hahn S.L. , Snopek K.M.
Published: January 2014

In a recent paper, the authors have presented the unified theory of n-dimensional (n-D) complex and hypercomplex analytic signals with single-orthant spectra. This paper describes a specific form of these signals called quasi-analytic. A quasi-analytic signal is a product of a n-D low-pass (base-band) real (in general non-separable) signal and a n-D complex or hypercomplex carrier. By a suitable choice of the carrier frequency, the spectrum of a low-pass signal is shifted into a single orthant of the Fourier frequency space with a negligible leakage into other orthants. A measure of this leakage is defined. Properties of quasi-analytic signals are studied. Problems of polar representation of quasi-analytic signals and of its lower rank representation are discussed.
Geotourism development in the Azores archipelago (Portugal) as an environmental awareness tool
Authors: Lima Eva Almeida , Machado Marisa , Nunes João Carlos
Published: January 2014

The Azores archipelago is distinguished by its unique natural beauty and marine setting. Thanks to its volcanic origin, the region has a very rich and remarkable geodiversity that includes a diversity of landscapes with innumerable craters, volcanic lakes, fumaroles, hot springs, volcanic caves, marine fossil deposits and thermal water springs. The recognition of this valuable geological heritage came with the recent integration of the Azores Geopark into the European and Global Geopark Networks. The pressure that the increasing development of tourism have been exerting on these geological sites for the last years, and the need to create alternative forms of tourism, which contribute towards the socio-economic development in rural areas, have highlighted the importance of geotourism as a tool to promote and preserve the geological heritage of the Azores. Geotourism has turned to be an important instrument of environmental awareness through the local and foreign people.
Megaclasts in geoconservation: sedimentological questions, anthropogenic influence, and geotourism potential
Authors: Lubova Katrin A. , Zayats Pavel P. , Ruban Dmitry A. , Tiess Günter
Published: January 2014

Megaclasts are sedimentary particles larger than boulders. Their huge size and scattered occurrence make them objects that deserve geological heritage, requiring conservation. Investigation of megaclasts for the purpose faces difficulties because of the distinction between boulders and megaclasts. Local study of Quaternary large stones in Mountainous Adygeja (W Caucasus, SW Russia) suggests ~ 2 m as a suitable size criterion, although only locally. Shape, occurrence, and origin of megaclasts require additional attention.

Geoconservation may result in anthropogenic disturbances of the natural landscape through removal of vegetation, access constructions, and restoration. The geotourism potential of megaclasts is partly determined by their huge size and their rare and scattered occurrence. Aesthetic qualities, local legends, and co-occurrence with prehistoric megalithic constructions increase this potential. The Maiden’s Stone in Mountainous Adygeja, which is ~ 35 m long, has been a tourist attraction already for decades. It is an impressive example of geoconconservation and geotourism connected with megaclasts. Generally, megaclasts increase the value (including the scientific importance) of the geological heritage of Mountainous Adygeja, where a geopark might be established.
Cenozoic synthem stratigraphic architecture of the SE Brazilian shelf and its global eustatic context: evidence from the Pelotas Basin (offshore Brazil)
Authors: de Santana dos Anjos Zerfass Geise , Ruban Dmitry A. , Chemale Jr. Farid , Zerfass Henrique
Published: January 2014

The Pelotas Basin, located on the SE Brazilian shelf, has evolved since the Aptian. Stratigraphical data from the basin can be used for delineation of the unconformity-bounded units (synthems) on the shelf, which is a first step towards a full understanding of its stratigraphic architecture, evolution, and hydrocarbon potential. Hiatuses in the Cenozoic succession of the Pelotas Basin are established with both biostratigraphic (planktonic foraminifers and calcareous nannofossils) and isotopic (87Sr/86Sr) data. The seven recognised hiatuses are dated respectively as (1) Palaeocene (Danian- Thanetian), (2) Palaeocene/Eocene boundary (Thanetian-Ypresian), (3) Eocene (Ypresian-Lutetian), (4) Eocene-Oligocene (Lutetian-Rupelian), (5) early-late Oligocene (Rupelian-Chattian), (6) early Miocene (Aquitanian-Burdigalian), and (7) middle-late Miocene (Serravallian-Tortonian). These intervals between the hiatuses are correlated with those of the Santos and Campos Basins north from the Pelotas Basin.

The breaks in sedimentation that these basins have in common occurred (1) at the Palaeocene-Eocene and (2) Eocene-Oligocene transitions, (3) in the early Miocene, and (4) in the middle-late Miocene. These main unconformities outline five synthems on the SE Brazilian shelf, viz. the SEBS-1 (Palaeocene), SEBS-2 (Eocene), SEBS-3 (Oligocene), SEBS-4 (early-middle Miocene) and SEBS-5 (late Miocene-Holocene). The above unconformities are correlated with those established in the Cenozoic sedimentary successions of different regions such as Western Siberia, Arabia, NW and NE Africa, peninsular India, S Australia, the Gulf of Mexico, NW Europe, and South Africa.

The only regional unconformity, near the Oligocene/Miocene boundary, coincides with the nearly-global sedimentation break. The latter was resulted from a climatic event, i.e., the ‘Mi-1 glaciation’. Thus, a eustatic origin is supposed for this regional unconformity. The other regional unconformities also correspond to global sea-level falls (probably with an exception for the Palaeocene/Eocene surface), which suggests that global eustatic movements controlled the development of the regional synthem architecture.
SMALL HYDROPOWER IN LATVIA AND INTELLECTUALIZATION OF ITS OPERATING SYSTEMS / PAR MAZO HIDROENERĢĒTIKU LATVIJĀ UN TĀS STACIJU VADĪBAS SISTĒMAS INTELEKTUALIZĀCIJU
Authors: Mahnitko A. , Gerhards J. , Linkevics O. , Varfolomejeva R. , Umbrasko I.
Published: January 2014

The authors estimate the potential for power generation from water resources of small and medium-sized rivers, which are abundant in Latvia. They propose the algorithm for optimal operation of a small-scale hydropower plant (SHPP) at the chosen optimality criterion in view of the plant’s participation in the market. The choice of SHPP optimization algorithm is made based on two mathematical programming methods - dynamic and generalized reduced gradient ones. Approbation of the algorithm is illustrated by an example of optimized SHPP operation.
LATVIAN WASTE MANAGEMENT MODELLING IN VIEW OF ENVIRONMENTAL IMPACT REDUCTION / LATVIJAS ATKRITUMU SAIMNIECĪBAS ATTĪSTĪBA UN TĀS RADĪTĀS IETEKMES UZ VIDI SAMAZINĀŠANAS MODELĒŠANA
Authors: Teibe I. , Bendere R. , Arina D.
Published: January 2014

In the work, the life-cycle assessment approach is applied to the planning of waste management development in a seaside region (Piejūra) using the Waste Management Planning System (WAMPS) program. In Latvia, the measures to be taken for the climate change mitigation are of utmost importance - especially as related to the WM performance, since a disposal of biodegradable waste presents the primary source of GHG emissions. To reduce the amount of such waste is therefore one of the most significant goals in the State WM plan for 2013-2020, whose adoption is the greatest challenge for municipalities. The authors analyse seven models which involve widely employed biomass processing methods, are based on experimental data and intended for minimising the direct disposal of organic mass at the solid waste landfills. The numerical results obtained evidence that the thermal or biotechnological treatment of organic waste substantially reduces the negative environmental impact of WM practices - by up to 6% as compared with the currently existing.
Evaluation of the Influence of Various Biodegradable Packaging Materials on the Quality and Shelf Life of Different Food Products
Authors: Dukalska Lija , Ungure Eva , Augspole Ingrida , Muizniece-Brasava Sandra , Levkane Vita , Tatjana Rakcejeva , Krasnova Inta
Published: January 2014

The aim of the present research was to summarize the results of investigations carried out on the influence of different biodegradable polymer packaging materials on the shelf life and quality of several food products during storage. In Latvia, most of consumers consider that polymers as a material for food packaging are overly used, and they support the idea of introducing new eco-friendly food packaging. Biodegradable films were investigated for their ability to extend the shelf life of apple salad and minimally processed shredded carrots stored at 4 °C. It was found that they can guaranty the same as or even a longer shelf life than that provided by conventional polymer films. Bio PLA transparent films, thermoformed PLA containers, and cellulose-based films were tested for fresh produce packaging. Ceramis®-PLA-SiOx barrier coated films were tested for their influence on the quality of food products - rye bread, apple-black currant marmalade candies, and soft cheese Kleo - during storage. PLA and PHB films showed satisfactory results for packaging of perishable foods - salad with meat in mayonnaise. Ceramis®-PLA-SiOx films were used for vacuum packaging and also for mild thermal treatment (Sous vide) of soft cheese, providing its prolonged shelf life. Some BoPLA films specially envisaged for packaging of confectionery were tested for milk pomade sweet - sherbet - packaging. Its quality was evaluated mainly by moisture content and by changes in hardness during storage. The results suggest that biodegradable packaging materials can be a successful alternative to the conventional polymers for packaging of several food products, which could provide an essential contribution in reducing the environmental pollution.
Health Care Accessibility Modeling: Effects of Change in Spatial Representation of Demand for Primary Health Care Services
Authors: Jankowski Piotr , Brown Blake
Published: January 2014

Health care accessibility can be measured by the number of prospective patients who could reach a medical facility within a prescribed time limit. The representation of health care demand in estimating accessibility is an important consideration since different spatial aggregations of demand have different consequences with regard to accessibility estimates. This article examines the effects of aggregating population demand for primary health care, ranging from census tract to aggregated census block, on estimates of primary health care accessibility. Spatial representations of aggregated demand were incorporated into a location-allocation model in order to determine a measure of accessibility represented by the unmet demand for primary health care services. The model was implemented for the U.S. State of Idaho, based on the allocation of Idaho residents’ demand for primary health care to the state’s existing primary health care facilities. The results confirm a relationship between the level of demand aggregation and the level of potential accessibility. In case of a rural state such as Idaho the relationship is positive; higher levels of aggregation result in higher measures of accessibility.