bluuebunny/crossref_metadata_2025 huggingface dataset:
Applying Computerized Concept Maps in Guiding Pupils to Reason and Solve Mathematical Problems: The Design Rationale and Effect
Authors: Chen I-Ching , Hu Shueh-Cheng
Published: November 2013

The capability of solving fundamental mathematical problems is essential to elementary school students; however instruction based on ordinary narration usually perplexes students. Concept mapping is well known for its effectiveness on assimilating and organizing knowledge, which is essential to meaningful learning. A variety of concept map-based instruction and assessment methods and software tools have been successfully applied to improve learning in diverse disciplines. This article presents a software tool that applies concept mapping and aims to train students in analyzing mathematical problems precisely and then solving them correctly. Additionally, an experiment investigating the tool's impact on children's capability of solving mathematical problems is reported. The experiment revealed that incorporating concept maps into the instruction process can successfully strengthen students' ability of reasoning and solving mathematical problems. Besides the quantitative analysis, an interview reflected that most students were inclined to use the tool as well as the approach that instructed learners how to reason and solve mathematical problems.
“I was Just Trying to Stick it Out Until I Realized that I Couldn'T”: A Phenomenological Investigation of Support Seeking among Older Adults with Complicated Grief
Authors: Ghesquiere Angela
Published: November 2013

Complicated Grief (CG) is a prolonged, impairing mental health condition affecting about 7% of the bereaved. CG may be especially prevalent in older adults. Though evidence-based treatments for CG have been developed, little is known about support-seeking in older adults with CG. This study used the descriptive phenomenological approach to explore the CG support-seeking process. In-depth interviews were conducted with 8 CG-positive older adults who had completed participation in a randomized clinical trial of CG treatment. Five primary themes arose: observing that grief was causing a great deal of distress and impairment; grief not meeting expectations of what grief “should be”; an important influence of social relationships on support-seeking; lack of effectiveness of grief support groups and/or care from mental health professionals prior to study enrollment; and strong reactions to the label of CG. Themes may hep inform efforts to engage older adults with CG in effective care.
Development of Suicidality within Socioeconomic Context: Mediation Effect of Parental Control and Anomie
Authors: Heydari Arash , Teymoori Ali , Nasiri Hedayat
Published: November 2013

Despite some scientific research on suicide as one of the most serious social and mental health problems in Iran, there is still lack of research on the effective structural and socio-familial factors contributing to the issue in Iran. The purpose of this study is to investigate some of the effective variables conditioning suicidality while also establishing a synthetic model. Three hundred-fifty university students (165 males, 185 females) were randomly chosen from Shahid Chamran University, Ahvaz, Iran. The participants were asked to complete a package of self-report questionnaires including subjective socioeconomic status (SES), feeling of anomie, perceived parental control, and suicidality. The results show that all correlations among variables are significant. For testing the theoretical model, results of standardized regression coefficients suggest that SES has direct effect on suicidality and indirect effect via anomie and parental control. In addition, parental control has direct effects on suicidality and indirect effect via anomie as well. The findings confirm the expected paths hypothesized among variables which are consistent with the theories of Durkheim, Merton, Kohn, and Agnew. It implies that the development of suicidality takes place within socioeconomic context through the influence of parental control and feeling of anomie.
Effects of cadmium-induced oxidative stress on growth and nitrogen assimilation in blackgram [Vigna mungo (L.) Hepper]
Authors: Mobin Mohammad
Published: November 2013

Cadmium (Cd) accumulation, oxidative damage, and nitrogen metabolism were
studied in roots and leaves of 30-d-old blackgram plants [Vigna mungo (L.)
Hepper], grown in a mixture of soil and compost (3:1) with different Cd
concentrations. Significant reductions in both root and shoot dry weight were
noted. The concentration of Cd in roots and leaves increased with increasing
Cd levels. The level of lipid peroxidation elevated with a consequent
increase in H2O2 content under Cd stress in both plant organs. The activity
of enzymes mediating the nitrogen assimilation in roots and leaves was
greatly reduced in the presence of Cd, except glutamate dehydrogenase (GDH)
which showed a significant increase.
Physical, chemical and structural effects as important factors for thermodynamic and transport properties determination and modelling of non-electrolyte solutions
Authors: Djordjevic Bojan , Kijevcanin Mirjana , Radovic Ivona , Serbanovic Slobodan , Tasic Aleksandar
Published: November 2013

In our previous review an attempt has been made to relate the volumetric
effects involved in the binary mixtures of normal and branched alcohols. This
paper summarized some selected research activities of various authors related
to complex molecular structure appearing in leading international journals.
The main aim was better understanding of complex structure of different
non-electrolyte mixtures with no alcohols, which are the most frequently
present in chemical, petrochemical and related industries. The influence of
the basic physical, chemical and structural effects of considerably chosen
type of various binary and ternary mixtures was analyzed. These contributions
are of primary importance for determination and modelling of thermodynamic,
transport and other properties.
Natural and artificial (90Sr) radionuclides in some carbonated mineral waters used in Serbia
Authors: Jankovic Marija , Sarap Natasa , Todorovic Dragana , Joksic Jasminka
Published: November 2013

A radiological characterization of 7 different carbonated mineral water
samples collected in the local supermarkets in the area of Belgrade (produced
in Serbia) was carried out. Analysis included determination of gross alpha
and gross beta activities. The obtained results showed that the natural
activity concentrations of alpha and beta emitting radionuclides in
carbonated mineral water samples were within World Health Organization
recommended levels, except for the Heba Strong and Kiseljak samples where the
beta activity exceeds 1 Bq/L. For these two water samples gamma spectrometry
analysis was performed as well as determination of 90Sr by oxalic method. The
instrumentation used to count the gross alpha and gross beta activities, as
well as for 90Sr, was a/b low level proportional counter Thermo Eberline FHT
770 T. Gamma spectrometric measurements were performed using a HPGe Canberra
detector with a counting efficiency of 20%. The annual effective dose
equivalent due to ingestion of investigated waters was calculated for age
group >17, and obtained values are lower than 0.1 mSv recommended reference
level. Finally, a comparison of the investigated waters with worldwide data
was made.
Simulation of radiation effects in ultra-thin insulating layers
Authors: Timotijevic Ljubinko , Vujisic Milos , Stankovic Koviljka
Published: November 2013

The Monte Carlo simulations of charged particle transport are used to
investigate the effects of exposing ultra-thin layers of insulators (commonly
used in integrated circuits) to beams of protons, alpha particles and heavy
ions. Materials considered include silicon dioxide, aluminum nitride,
alumina, and polycarbonate - lexan. The parameters that have been varied in
simulations include the energy of incident charged particles and insulating
layer thickness. Materials are compared according to both ionizing and
non-ionizing effects produced by the passage of radiation.
The effect of short-term low-energy ultraviolet B irradiation on bone mineral density and bone turnover markers in postmenopausal women with osteoporosis: A randomized single-blinded controlled clinical trial
Authors: Micic Ivan , Jeon In-Ho , Park So-Hyun , Hwa Seo-Sung , Chun Jae-Myeung , Stojiljkovic Predrag
Published: November 2013

Introduction. The importance of vitamin D on bone health and osteoporosis was
studied by many researchers. The main role of the Vitamin D is to absorb
calcium and phosphate and increase bone mineralization. Older people are at
an increased risk of the inadequate vitamin D production in the skin because
of lower sun exposure and reduced ability of the skin to synthesize vitamin
D. Objective. The aim of this clinical trial was to evaluate the efficacy and
tolerability of short-term (2 weeks) low energy UVB irradiation in
postmenopausal women with osteoporosis using bone mineral density and bone
turnover markers. Methods. A three-month, single-blinded, randomized,
placebo-controlled clinical trial was conducted at the University hospital in
Daegu, Republic of Korea. Fifty-two postmenopausal Korean women (older than
65 years) with osteoporosis were randomly allocated to have either low energy
UVB or placebo for 30 minutes a day for two weeks of treatment during winter.
Laboratory analysis and physical examination before and 4, 8 and 12 weeks
after treatment were carried out and BMD was measured before and 8 and 12
weeks after treatment. The effects of time and treatment interaction between
these two groups were evaluated by repeated-measure two-factor analysis, and
subgroup analysis was performed to examine UVB effect on the vitamin D
insufficient group [serum 25(OH)D3 concentration <30 ng/mL]. Results. In
vitamin D insufficient group, the effect of UVB irradiation on vitamin D and
bone ALP as well as additional benefit on bone formation was confirmed. The
vitamin D insufficient group showed statistically significant increment in
serum 25(OH)D3 compared with the normal group (p<0.05). However, there was no
significant difference between two groups in the other bone turnover markers,
such as serum calcium, PTH-C, serum osteocalcin, serum CTX and BMD.
Conclusion. Low-energy-short-term UVB radiation for postmenopausal women may
be of use in vitamin D synthesis. There was a modest benefit in change of
bone ALP especially in women with the insufficient vitamin D.
Chlorpromazine-induced status epilepticus: A case report
Authors: Momcilovic-Kostadinovic Dragana , Simonovic Perisa , Kolar Dusan , Jovic Nebojsa
Published: November 2013

Introduction. It is largely known that some antipsychotic agents could have
proconvulsive and proepileptogenic effects in some patients and could induce
EEG abnormalities as well. However, the association of status epilepticus
with certain antipsychotic drugs has been very rarely reported. Case Report.
A case of an 18-year-old adolescent girl, with chlorpromazine therapy started
for anxiety-phobic disorder was reported. Her personal history disclosed
delayed psychomotor development. Shortly after the introduction of the
neuroleptic chlorpromazine therapy in minimal daily dose (37.5 mg), she
developed myoclonic status epilepticus, confirmed by the EEG records.
Frequent, symmetrical bilateral myoclonic jerks and altered behavior were
associated with bilateral epileptiform discharges of polyspikes and
spike-wave complexes. This epileptic event lasted 3.5 hours and it was
stopped by the parenteral administration of valproate and lorazepam; she was
EEG monitored until stable remission. Status epilepticus as initial epileptic
event induced by neuroleptic agent was not previously reported in our
national literature. Conclusion. Introduction of chlorpromazine to a patient
without history of seizures is associated with the evolution of an epileptic
activity, including the occurrence of status epilepticus. Clinical evaluation
of the risk factors possibly related to chlorpromazine-induced seizure is
recommended in individual patients before administering this drug.
Cystic dystrophy of the duodenal wall in ectopic pancreas
Authors: Colovic Radoje , Grubor Nikica , Micev Marjan , Perisic Mirjana , Latincic Stojan , Colovic Natasa
Published: November 2013

Introduction. Cystic dystrophy of the duodenal wall is a rare complication of
the ectopic pancreas that is characterized by cyst/s formation within
thickened duodenal wall. Case Outline. A 61?year?old male with recurrent
abdominal pain, weight loss (about 25 kg) who had been moderate alcohol
abuser and heavy smoker was presented. On ultrasonography, very thickened
duodenal wall (2.5 cm), an enlarged head of the pancreas with cyst of 3 cm in
diameter as well as dilated pancreatic duct (<6 mm) were seen. Barium meal
showed stenosis of the first and second part of the duodenum. CT and
endoscopic ultrasound confirmed the ultrasonographic finding. The patient
underwent surgery. The pathologic finding was established only on first two
portions of the duodenum and limited part of the head of the pancreas along
duodenum while the rest of the pancreas was normal. Due to poor general
condition, gastrojejunostomy was performed. Although some improvement was
evident, the patient did not become asymptomatic, and, therefore, four months
later a cephalic duodenopancreatectomy was carried out which made him fully
asymptomatic. A year later, the patient was symptom?free and in good health.
Histologic examination showed a cystic dystrophy of the duodenal wall in
the ectopic pancreas. Conclusion. Unless there are strong contraindications,
cephalic duodenopancreatectomy is best treatment of the disease.
Peroxisome proliferator-activated receptor gamma as modulator of inflammation in pulmonary sarcoidosis
Authors: Pejcic Tatjana , Stankovic Ivana , Radjenovic-Petkovic Tatjana , Nastasijevic-Borovac Desa , Djordjevic Ivanka , Jeftovic-Stoimenov Tatjana
Published: November 2013

Peroxisome proliferator-activated receptor (PPAR) includes the family of
ligand-activated transcription factors which belong to the group of nuclear
hormone receptors and are connected to retinoid, glucocorticoid and thyroid
hormone receptors. There are three subtypes of PPARs: PPAR? (also known as
NR1C3), PPAR? (known as NR1C1) and PPAR? (known as PPAR? or NR1C2). All of
them take part in the metabolism, cell proliferation and immune response.
PPAR? and PPAR? are identified as important immunomodulators and potentially
represent an anti-inflammatory target for respiratory diseases. PPAR?
deficiency in the lungs has been observed in the inflammatory diseases such
as asthma, pulmonary alveolar proteinosis, fibrosis and sarcoidosis, as well
as in the animal models of the lung inflammation. A small number of papers
concerned with PPAR? in sarcoidosis point to the lowered activity of this
factor in the alveolar macrophages and a lowered gene expression for the
PPAR?, while the activity is preserved in healthy individuals. At the same
time, an increased activity of the nuclear factor kappa B (NF-kB) in the
bronchoalveolar lavage has been recorded in patients with sarcoidosis. The
reason for the decrease in the production of PPAR? in sarcoidosis remains
unknown. Several possible mechanisms are mentioned: genetic defect with
lowered production, down-regulation due to the increased values of IFN-? or
an increased decomposition of PPAR?. Further investigation will explain the
mechanisms regarding the decreased production of PPAR? in sarcoidosis.
Efficiency-wage model
Authors: Fabris Nikola
Published: November 2013

In classical theory, the labour market operates as any other market, that is,
the supply and demand determines the equilibrium between wages and the number
of employees. The Keynesians went a step further by pointing out that the
labour market does not follow the same principle as other markets and that
wages do not change due to numerous rigidities, i.e. that the equilibrium is
not achieved with full employment. The neoclassical macroeconomics reverts to
the classical theory, noting that the labour market equilibrium is achieved
immediately. The weakness of these theories is that they do not sufficiently
consider specific features of the labour market and/or human labour. However,
the new Keynesians went a step further in this direction by developing the
efficiency wage model incorporating both economic and sociological
explanations in the labour market interpretation. Nevertheless, it seems that
there is still enough room for further improvements of this model and the
paper communicates certain suggestions to that end.
Institutionalized Online Access to Corporate Information and Cost of Equity Capital: A Cross-Country Analysis
Authors: Rahman Asheq Razaur , Debreceny Roger S.
Published: November 2013

The demand for online information in stock markets around the world has led to many stock exchanges requiring the disclosure of information on listed corporations through the stock exchange website. We examine the impact of online access to corporate information on stock exchange websites on market transparency. We posit that institutionalized online information dissemination is likely to reduce the level of information asymmetry in stock markets. To increase the spread in the types of markets and market features in our sample, we expand the sample size of 40 or fewer countries commonly used in recent cross-country studies to 110 countries. Our proxy for the level of information asymmetry in stock markets is the cost of equity capital (COE). We examine the online availability of corporate information on the websites of the stock exchanges (AVAILABILITY) of the 110 countries, and find that there is a negative association between COE and AVAILABILITY. Further analysis shows that this association is stronger for emerging market countries, equity-based (common law) countries, and low press transparency countries. We conclude that while institutionalized online information dissemination is beneficial to all capital markets, it mostly benefits emerging capital markets, equity-based markets (common law countries) and markets with weaker alternative information sources.
Decentralized Task Assignment and Centralized Contracting: On the Optimal Allocation of Authority
Authors: Reichmann Steffen , Rohlfing-Bastian Anna
Published: November 2013

To provide efficient incentives, the three components of an incentive system (i.e., performance measurement, rewards, and the allocation of decision rights) need to be balanced against each other. In practice, the authority to decide on these components is frequently distributed across hierarchical levels, thus requiring adjusting centralized decisions with regard to decentralized authority. This paper investigates the centralized design of incentive contracts when decision authority, with respect to the allocation of tasks, is delegated to lower hierarchical levels. It provides an analysis of the optimal allocation of authority (i.e., “who should be the boss”) and considers the interdependencies between organizational design choices and the design of optimal incentives.
Insulin Resistance Alters Islet Morphology in Nondiabetic Humans
Authors: Mezza Teresa , Muscogiuri Giovanna , Sorice Gian Pio , Clemente Gennaro , Hu Jiang , Pontecorvi Alfredo , Holst Jens J. , Giaccari Andrea , Kulkarni Rohit N.
Published: November 2013

Type 2 diabetes is characterized by poor glucose uptake in metabolic tissues and manifests when insulin secretion fails to cope with worsening insulin resistance. In addition to its effects on skeletal muscle, liver, and adipose tissue metabolism, it is evident that insulin resistance also affects pancreatic β-cells. To directly examine the alterations that occur in islet morphology as part of an adaptive mechanism to insulin resistance, we evaluated pancreas samples obtained during pancreatoduodenectomy from nondiabetic subjects who were insulin-resistant or insulin-sensitive. We also compared insulin sensitivity, insulin secretion, and incretin levels between the two groups. We report an increased islet size and an elevated number of β- and α-cells that resulted in an altered β-cell–to–α-cell area in the insulin- resistant group. Our data in this series of studies suggest that neogenesis from duct cells and transdifferentiation of α-cells are potential contributors to the β-cell compensatory response to insulin resistance in the absence of overt diabetes.
Badanie wpływu ładunku utleniacza na charakterystyki energetyczne strumienia gazów prochowych silnika rakietowego na paliwo stałe
Authors: Pietraszek Mariusz , Klemba Tomasz
Published: November 2013

Streszczenie

W pracy przedstawiono wyniki badań wpływu ładunku utleniacza na charakterystyki pracy silnika rakietowego, w kontekście przeciwdziałania pompażowi silnika śmigłowca. Homogeniczne paliwo stałe silnika rakietowego charakteryzuje się ujemnym bilansem tlenowym. W przypadku odpalania serią pocisków rakietowych napędzanych takim paliwem ze śmigłowca istnieje możliwość wystąpienia zjawiska pompażu, które może doprowadzić do zgaśnięcia jego silników. Wprowadzenie do komory spalania silnika rakietowego na paliwo stałe siarczanu (VI) potasu (II) jako inhibitora reakcji spalania paliwa rakietowego korzystnie zmienia charakterystyki energetyczne silnika rakietowego, jednocześnie nie wpływając na generowany ciąg. Zastosowanie utleniacza jako wkładu do silnika znacząco poprawia bezpieczeństwo odpalania rakiet ze statku powietrznego i nie wymusza zmian w konstrukcji silnika. Praca zawiera wyniki badań wpływu ładunku K2SO4, w postaci zaprasowanego pręta, na charakterystyki pracy silnika rakietowego Mk66. W trakcie badań na hamowni pionowej zmierzono ciąg oraz temperaturę gazów strumienia gazów wylotowych. Wyniki zestawiono z danymi dla oryginalnych silników.
Diagnozowanie i monitorowanie stanu technicznego elektrycznych pomp paliwowych statków powietrznych
Authors: Tokarski Tomasz , Gębura Andrzej
Published: November 2013

Streszczenie

W pracy omówiono wybrane problemy eksploatacyjne elektrycznych pomp paliwowych. Są one niezbędne do wytworzenia nadciśnienia przed pompą nurnikową silnika turboodrzutowego. Po jej awarii może dojść do zapowietrzenia pompy nurnikowej i zgaśnięcia silnika. Porównano zalety i wady dwóch typów elektrycznych napędów pomp paliwowych: trójfazowego prądu przemiennego 115/208 VG, 400 Hz i prądu stałego 28 V. Przedstawiono możliwości diagnozowania i monitorowania stanu technicznego elektrycznych pomp paliwowych przez ITWL.
Algorytmy sterowania mav w oparciu o analizę sygnałów wizyjnych
Authors: Wijaszka Mirosław
Published: November 2013

Streszczenie

W opracowaniu przedstawiono metody analizy obrazu wykorzystywane w wizyjnych systemach sterowania MAV. Rozważania przedstawiono w oparciu o hipotetyczny model MAV umieszczony w środowisku pozbawionym możliwości wykorzystania systemów GPS, wewnątrz budynku, model będzie się poruszał autonomicznie na podstawie rozpoznanych za pomocą kamery konturów i punktów charakterystycznych. W pracy przyjęto, że statek wykorzystuje niezależny system stabilizacji położenia zapewniający utrzymanie zerowych kątów pochylenia i przechylenia oraz stałej, zadanej wysokości. Na czole statku umieszczona jest kamera, której oś tworzy z osią statku w płaszczyźnie pionowej znany kąt β (20- 30°). Analizę obrazu oparto o bibliotekę OpenCV (Open Source Computer Vision Library - http://opencv.willowgarage.com).
Variations in Mechanical Parameters of Rock Mass Affecting Shaft Lining / Zmiany Parametrów Mechanicznych Górotworu I Ich Wpływ Na Obudowę Szybową
Authors: Majcherczyk Tadeusz , Niedbalski Zbigniew , Wałach Daniel
Published: November 2013

The paper presents geomechanical properties of rock mass occurring in the initial section of shaft lining during its execution. The shaft being sunk is surrounded with cohesive soils, mainly clays with sand layers and silts. Such lithology causes that in various levels some parts of strata are saturated with water. This results in a considerable changeability of soil properties in time. With high water content, the soil is washed away leading to local loss of contact between shaft lining and surrounding soils. This, in turn, results in lack of proper support for curbs and shaft lining fracture in some sections. Engineering activity in such a case should embrace sealing injections in selected parts of the shaft in order to resume proper reinforcement in the lining-rock mass system. The studies of the soils surrounding shaft lining were supposed to help design curbs with increased bearing capacity. The tests of soils indicated that the angle of internal friction and cohesion do change not only at different depths but also at the same depth in different points of perimeter. It was also observed during the study that the mechanical parameters of the analyzed soils improve as the distance from the shaft lining increases, which clearly indicates change of soil properties in the direct neighborhood of the shaft. Considerable number of tests carried out in the study allowed to determine the relationship between water content and angle of internal friction or soil cohesion. The determined relationships can help to estimate change of soil properties under the influence of water with considerable precision. The reinforcement of curbs executed with the use of ground anchors allowed for further shaft sinking. The tests of concrete used in the shaft carried out in the analyzed section produced results similar to the values assumed in the project.
Assessment of the Condition of Hoisting Ropes by Measuring their Geometric Parameters in a Three-Dimensional Image of their Surface / Metoda Oceny Stanu Lin Wyciągowych Poprzez Pomiar Parametrów Geometrycznych Na Trójwymiarowym Obrazie Ich Powierzchni
Authors: Olszyna Grzegorz , Sioma Andrzej , Tytko Andrzej
Published: November 2013

This article discusses a vision method of measuring the geometric parameters of ropes and evaluating their wear based on measurements made in a three-dimensional projection of rope surface. The purposes of this method include assessment of the condition of all kinds of ropes working in the mining industry. The proposed method is novel, eliminates the shortcomings of previously used mandatory visual methods, removes their constraints, and is an important complement to magnetic methods. The article discusses the method of construction of a three-dimensional image based on mapping of the actual dimensions of the rope and on algorithms that allow determination of the parameters describing its basic geometrical dimensions and surface condition. The article discusses issues related to resolution of the vision system, resolution of laser beam analysis, and resolution relating to the measurement of the height profile on the surface of the rope. Based on the image constructed in such a way, measurements are presented in order to assess the dimensional parameters and surface defects in sample rope structures. Based on tests and analyses of the three-dimensional image, a range of inspection tasks using 3D vision systems is indicated.
Numerical Study of the Hydrodynamic Efficiency of the Multi-Stage Filter Setting Technology / Studium Numeryczne Efektywności Hydrodynamicznej Otworów Eksploatacyjnych Z Zastosowaniem Wielostopniowych Selektywnych Filtrów
Authors: Kuljabekov A.B. , Inkarbekov M.K , Tungatarova M.S. , Alibayeva K.A. , Kaltayev A.
Published: November 2013

In this work the numerical study of the hydrodynamic efficiency of the multistage filters setting technology is carried out on the basis of mathematical simulation. Obtained results of a flow of solution in porous media near a wellbore qualitatively conform to the experimental data.

In calculations the well is considered as the high-permeability channel with the fictitious permeability coefficient depending on a filter construction (porosity, form of perforations). The results of calculation show that the fictitious permeability coefficient has deep influence on the fluid influx to the well and the distribution of flow rate on well height is not uniform. The developed model is used for the axisymmetric case.

Calculations were carried out for a single well; however it can be easily applied to solve the 3D problem with various sets of wells.
Three-Dimensional Numerical Simulation of the Mass Exchange Between Longwall Headings and Goafs, in the Presence of Methane Drainage in A U-Type Ventilated Longwall / Symulacja Numeryczna 3D Procesów Wymiany Masy W Układzie Wyrobiska Ścianowe Zroby, W Aspekcie Prowadzenia Odmetanowania Ściany Przewietrzanej Systemem Na „U”
Authors: Skotniczny Przemysław
Published: November 2013

The phenomena related to the occurrence of methane in underground mines pose a considerable danger in the process of coal seam exploitation. Quite often, experimental analysis falls short of investigating their areas of origin (goafs area, affected rock mass, the tail gate area with abandoned excavation). Therefore, an invaluable tool for evaluating the risk involved in the exploitation process might be the numerical simulation of the phenomenon in question, carried out with the use of the latest CFD methods. Due to its application, we are able to recreate and predict the mechanism of the studied phenomenon, with certain assumptions and simplifications made.

The present paper discusses the results of the numerical simulation of the process of mass exchange occurring between affected rock mass and longwall headings. The calculations were performed for two test cases - 100 meter long walls.
Influence of Polycarboxylate Superplasticizers on Rheological Properties of Cement Slurries Used in Drilling Technologies / Wpływ Superplastyfikatorów Z Grupy Polikarboksylanów Na Właściwości Reologiczne Zaczynów Cementowych Stosowanych W Technologiach Wiertniczych
Authors: Stryczek Stanisław , Wiśniowski Rafał , Gonet Andrzej , Złotkowski Albert , Ziaja Jan
Published: November 2013

Sealing slurries, mainly the cement-based ones, are concentrated dispersive systems, containing solid particles of considerably developed specific surface. Rheologically, such systems are very complex. This also stems from the fact that the rheological properties have a significant effect on:

• additives and admixtures modifying technological properties of fresh and set slurries,

• chemically complex mechanism of hydration in a slurry in a function of time.

Special attention should paid to plasticizing (plasticizers PL) and liquefying (traditional and new- -generation superplasticizers SP) admixtures affecting the modification and optimization of rheological properties of fresh cement slurries as far as providing efficiency of sealing of casing pipes is concerned.

Laboratory analyses were focused on proving the following thesis: properly selected type of superplasticizer [by BASF Polska Sp.z o.o. (The Chemical Company) - Admixtures for Concrete Division] advantageously affects the rheological parameters of sealing slurry based on metallurgical cement CEM III /A 32,5.

The following variables were used in the analyses:

• type of superplasticizer,

• type of batch fluid.

The laboratory experiments were made on superplasticizers produced by BASF:

• SKY 501,

• SKY 503,

• SKY 591,

• ACE 430,

• Glenium 115.

The superplasticizer concentration in the slurry was 0.5 wt% (as compared with mass of dry cement). Water to cement ratio for the analyzed sealing slurries was equal to 0.5. The sealing slurries were made of metallurgical cement CEM III/A 32,5 N-LH/HSR/N Lafarge Cement S.A. in Małogoszcz.
Modified Stability Charts for Rock Slopes Based on the Hoek-Brown Failure Criterion / Zmodyfikowane Diagramy Stabilności Skalistych Zboczy Otrzymane W Oparciu O Warunek Wytrzymałości Hoeka-Browna
Authors: Nekouei Mahdi , Ahangari Kaveh
Published: November 2013

Only an article rendered by Lia et al. in 2008 has represented charts based on Hoek-Brown criterion for rock slopes, however, these charts are not precise and efficient. Because of this problem, a modification is suggested for the mentioned charts in this study. The new charts are calculated according to four methods. Among the methods, one relates to finite element method using Phase2 software. The other three methods are Janbu, Bishop and Fellenius that belong to limit equilibrium method by using Slide software. For each slope angle, the method having high correlation coefficient is selected as the best one. Then, final charts are rendered according to the selected method and its specific equations. Among forty equations, twenty-five ones or 62.5% relate to numerical method and Phase2 software, six ones or 15% belong to Fellenius limit equilibrium, six ones or 15% relate to Bishop limit equilibrium, and three ones or 7.5% belong to Janbu limit equilibrium. In order to validate new charts, slope stability analysis is carried out for several sections of Chadormalu iron ore open pit mine, Iran. The error percentage of new charts in limit equilibrium method using Slide software and in Bishop method for slopes of Chadormalu iron ore mine are rendered and compared. The charts on a basis of Hoek-Brown failure criterion for rock slopes show less than ±4% error. This indicates that these charts are appropriate tools and their safety factor is optimal for rock slopes.
Natural Gas and the Transformation of the Energy Sector in The Netherlands / Gaz Ziemny A Transformacja Sektora Energii W Holandii
Authors: Frączek Paweł , Kaliski Maciej , Siemek Paweł
Published: November 2013

The aim of this paper is to discuss the conditions for the modernization of the energy sector in the Netherlands following the discovery of natural gas deposits in the country and a rapidly growing importance of this fuel. Hence the paper presents the essence of the model of transition management in the energy sector. It also shows the nature of changes in the structure of primary energy sources in the Netherlands and the decisive factors that led to the prominent role of natural gas in this country. These considerations formed the basis for discussion on the contemporary energy policy in the Netherlands.
Accuracy Estimation of the Approximated Methods Used for Assessing Risk of Buildings Damage Under the Influence of Underground Exploitation in the Light of World’s and Polish Experience – Part 2 / Analiza Dokładności Przybliżonych Metod Oceny Zagrożenia Budynków Wpływami Podziemnej Eksploatacji Stosowanych W Świecie I Polskiej Metody Punktowej – Część 2
Authors: Malinowska Agnieszka
Published: November 2013

This paper is a continuation of theoretical analyses of World’s methods used for assessing damage risk to buildings with continuous strains, which were presented in Part 1. The authors focus only on those methods in which the scale of damage to buildings can be approximated. Selected methods were tested on 100 random objects sited in hard coal excavation-induced areas. The efficiency and effectiveness of those methods was evaluated. The damage risk was also verified with the use of a method currently used in Poland. The efficiency results obtained for World’s methods and the one used in Poland turned out to be comparable. Practical studies were made to evaluate the adaptability of those methods in the underground exploitation-induced conditions in Poland.
Influence of The Metamorphism Grade and Porosity of Hard Coal on Sorption and Desorption of Propane / Wpływ Stopnia Metamorfizmu I Porowatości Węgli Kamiennych Na Sorpcję I Desorpcję Propanu
Authors: Dudzińska Agnieszka , Żyła Mieczysław , Cygankiewicz Janusz
Published: November 2013

In this paper results of investigations of sorption of hard coal samples collected from the extracted coal seams of Polish coal mines are presented. As sorbate propane was used. Examinations were carried out in the temperature of 298 K by means of volumetric assessment with the use of apparatus ASAP 2010 of Micromeritics. On the basis of conducted examinations it has been found out that the amount of sorbed propane depend on a type of coal, its metamorphism grade, content of oxygen element, moisture and porosity of these coals. The greatest amounts of propane are sorbed by low carbonized, high-porosity coals of high content of oxygen and moisture. Sorption of relatively high amounts of propane by these coals (ca. 10 cm3/g) is a result of the influence of polar surface of coals with molecules of propane and good availability of internal microporous structure of these coals for molecules of examined sorbate. Medium and high carbonized coals sorb insignificant amounts of propane. These coals have compact structure and non-polar character of their surface, their internal porous structure is to a minor degree available for propane molecules in conditions of carried out research. Sorption of propane in this case, takes place mainly in surface pores and on the surface of coals. Moreover, measurements of desorption isotherms of propane showing irreversible character of sorption were made. Desorption isotherms do not come together with sorption isotherms forming open hysteresis loop. Amounts of non-desorbing propane remaining in the coal depend on the type of examined coal.
Plant Type Selection for Reclamation of Sarcheshmeh Copper Mine Using Fuzzy-Topsis Approach / Wybór Gatunków Roślin Do Wykorzystania W Projekcie Rekultywacji Terenów Kopalni Miedzi Sarcheshmeh Z Wykorzystaniem Metod Logiki Rozmytej Topsis
Authors: Ebrahimabadi Arash , Alavi Iraj
Published: November 2013

Plant species selection is a multi-criteria evaluation decision and has a strategic importance for many companies. The conventional methods for plant species selection are inadequate for dealing with the imprecise or vague nature of linguistic assessment. To overcome this difficulty, fuzzy multi-criteria decision-making methods are proposed. The aim of this study is to use the fuzzy technique for order preference by similarity to ideal solution (F.TOPSIS) methods for the selection of plant species in mine reclamation plan. Plant type selection and planting to protect the environment and the reclamation of the mine are some of the most important solutions. Therefore, the objective of the current research study is to choose the proper plant types for reclamation of Sarcheshmeh Copper Mine using Fuzzy-topsis method. In this regard, primarily, surrounding area of Sarcheshmeh copper mine, one of the world’s 10 biggest copper mine which is located near Kerman city of Iran, are surveyed, to choose the best plant type for reclamation of disturbance area. With this respect, based on reclamation plan, primary criteria were consisted of kinds of post mining land use, climate, and nature of soil. Comparison matrixes were then obtained based on experts’ opinion and plant types were subsequently prioritized using the Fuzzy Topsis method. Secondary factors considered through the analysis were as follows: perspective of the region, resistance against disease and insects, strength and method of growth, availability to plant type, economic efficiency, protection of soil, storing water, and prevention of pollution. Finally, suitable plant types in the mining perimeter were prioritized as: Amygdalus scoparia, Tamarix, Pistachio Wild, Ephedra, Astragalus, Salsola, respectively.
Selected Properties of Flotation Tailings Wastes Deposited in the Gilów and Żelazny Most Waste Reservoirs Regarding Their Potential Environmental Management / Wybrane Właściwości Odpadów Poflotacyjnych Zdeponowanych W Zbiornikach Gilów I Żelazny Most W Aspekcie Możliwości Ich Zagospodarowania Przyrodniczego
Authors: Baran Agnieszka , Śliwka Małgorzata , Lis Marcin
Published: November 2013

Wastes originating from copper mining, particularly generated during the ore enrichment process constitute a considerable percentage of industrial wastes in Poland, which theoretically are supposed to provide a raw material base but remain wholly unmanaged. Wastes from copper flotation are deposited on the waste dumps which pose a significant eco-toxicological hazard. The paper discussed the results of analysis of selected post-floatation waste properties deposited in the Żelazny Most and Gilów reservoirs from the perspective of their environmental management.
Difficulties in myocardial protection, tactics and surgical technique in the surgical treatment of a giant pseudoaneurysm of the ascending aorta
Authors: Raicea V. , Moraru L. , Kovacs Judith , Suciu H. , Deac R.
Published: November 2013

We present the case of a 65 years old patient, initially hospitalized at Regional Pneumology Clinic with marked fatigue, severe pulmonary symptoms (suddenly developed severe resting dyspnea, orthopnea, irritating cough), loss of appetite, weight loss and dysphagia. Chest radiography raises the suspicion of giant ascending aortic aneurysm. Echocardiography confirms the presence of the aneurysm, but CT scan with contrast and angiography showed a giant pseudoaneurysm of ascending aorta with severe local compression of the right lung hilum and right main bronchus and in posterior on the esophagus. Coronary angiography also shows significant compression and deformation of the left main coronary artery. Echocardiography reveals marked dilated ascending aorta in the suprabulbar portion without aortic insufficiency. Replacement of the ascending aorta was performed in extracorporeal circulation with a impregnated Dacron prosthesis. Because of technically difficult approach, the ascending aorta ( being the right anterolateral wall of the pseudoaneurysm) was incanculated via right axillary artery, the aortic crossclamp was performed initially transluminal with Foley catheter and later with classical metallic instruments, and myocardial protection was achieved initially by retrograde administration of cardioplegic solution with monitoring of lactic acid, pH and base excess simultaneous from coronary sinus and the coronary ostia during administration of cardioplegic solution. The postoperative evolution was favorable, the weaning from extracorporeal circulation was succeeded without inotropics, with a 48 hours length of stay in ICU, and the patient was discharged after 8 days postoperatively.
Implementation of a New Methodology of Emission Inspections in Motor Vehicles with an Advanced Emission System
Authors: Lenďák Peter , Hujo Ľubomír , Jablonický Juraj , Angelovič Michal
Published: November 2013

This paper focuses on the implementation of a new exhaust-emission measurement system of motor vehicles equipped with a petrol engine and an advanced emission system. Our study deals with new methods of emission inspections using on-board diagnostics in order to increase the efficiency of emission inspection itself. The aim of implementing the new method of emission measurement is to eliminate vehicles that contribute to air pollution with emissions, due to an insufficient technical condition of the petrol engine fuel supply system.
Comparison of methods for detecting fungi in Silybum marianum (L.) Gaertn. seeds
Authors: Rosińska Agnieszka , Jarosz Magdalena , Szopińska Dorota , Dorna Hanna , Tylkowska Krystyna
Published: November 2013

Milk thistle (Silybum marianum (L.) Gaertn.) is one of the most important medicinal plants. The fungi infesting its seeds may negatively influence their germination and health-promoting properties. However, there is no standard method for S. marianum seed health testing. The aim of this study was to find a suitable method for the detection and identification of fungi in/on milk thistle seeds. The following tests were used: deep-freeze blotter test, blotter test with an addition of mannitol, blotter test with an addition of polyethylene glycol, agar test on potato-dextrose agar (PDA), agar test on PDA after seed disinfection, agar test on reduced PDA and an agar test on reduced PDA after seed disinfection. Seeds were incubated for 10 and 14 days. The most prevalent fungi were: Alternaria alternata, Botrytis cinerea, Cladosporium spp., Fusarium spp., Penicillium spp., Rhizopus nigricans and Verticillium spp. A deep-freeze blotter test followed by a blotter test with an addition of mannitol and a blotter test with an addition of polyethylene glycol performed for 14 days could be recommended for the further study of milk thistle seed health testing, as they favoured the growth of the most important fungi.
Assessment of Technical Condition Demonstrated by Gas Turbine Blades by Processing of Images for Their Surfaces / Oceny Stanu Łopatek Turbiny Gazowej Metodą Przetwarzania Obrazów Ich Powierzchni
Authors: Błachnio Józef , Spychała Jarosław , Pawlak Wojciech , Kułaszka Artur
Published: November 2013

The paper presents a non-destructive test method that makes it possible to assess condition of gas turbine blades based on the analysis of their images acquired in visible light. The results of high temperature’s influence on the condition of blades are revealed. The direct relationship between the temperatures of blades and discoloration of their surfaces is demonstrated. These relationships have been found out by the analysis of images in the form of first order statistical parameters derived wherefrom. The studies revealed alterations of the blade superalloy microstructures entailed by the effect of high temperature, hence the results in the form of first order statistical parameters could be correlated against alterations of the blade superalloy microstructures. Eventually, the variations of first order statistical parameters as well as variations of the blade superalloy microstructures could be determined as the functions of temperature. These relationships make it possible to assess how much the alloy microstructure is altered due to high temperature merely by discoloration of the blade surface. The innovative method can be used for in-flight evaluation of the superalloy overheating for gas turbine blades in operation.
Dynamic Heeling Moment Due to Liquid Sloshing in a Rectangular Tank of Different Dimensions and Elevation in Ship’S Hull / Dynamiczny Moment Przechylający Od Swobodnych Powierzchni Cieczy W Prostokątnym Zbiorniku Okrętowym O Różnych Wymiarach I Lokalizacji Pionowej
Authors: Krata Przemysław , Jachowski Jacek
Published: November 2013

Liquid sloshing phenomenon taking place in partly filled ships’ tanks directly affects the stability of a vessel and her safety on seaway, however, only static calculations are carried out onboard ships nowadays. The presented investigation is focused on dynamic approach towards liquid motion onboard ships. The set of numerical simulations of liquid sloshing taking place in moving tanks is carried out in terms of tank’s dimensions and its elevation within ship’s hull. A number of characteristics of the heeling moment due to liquid sloshing is obtained and analyzed.
Glutathione-S-Transferase M1 and T1 Gene Polymorphisms and Susceptibility to the Progression of Liver Fibrosis in Hcv-Infected Patients in Taiwan
Authors: Sun Fang-Chun , Jeng Ya-Chung , Lee Meng-Shiou , Wen Chen-Fan , Chen Tsung-Ming , Lee Meng-Shiunn
Published: November 2013

Background: This study was conducted to evaluate the influence of glutathione-S-transferase (GST) M1 and T1 polymorphisms in 184 patients with different stages of liver fibrosis and hepatitis C virus infection and 173 healthy control subjects.

Methods: DNA samples were extracted from whole blood, and the polymorphisms of GSTM1 and GSTT1 were determined with PCR using fluorescence-labeled Taq Man probes. Associations between specific genotypes and progression of liver fibrosis were examined by use of the logistic regression analysis to calculate the odds ratio (OR) and 95% confidence intervals (CI).

Results: Results show that no differences were found between the frequencies of GSTM1 (49.8% versus 50.2%) and GSTT1 (52.2% versus 47.8%) null genotypes in HCV-infected pa tients and healthy controls, respectively. In addition, there was also no significant relation between the frequency of GSTM1 or GSTT1 gene polymorphisms and fibrosis stage as classified by the METAVIR group.

Conclusions: The combined GSTM1 and GSTT1 null genotypes showed an association between GSTM1 [-]/GSTT1 [- ] and progression of liver fibrosis.