bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of the Theoretical Model of Determining the Strength of Cores Made by the Blowing Method
Authors: Dańko R.
Published: October 2017

Core sands for blowing processes, belong to these sands in which small amount of the applied binding material has the ability of covering the sand matrix surface in a way which - at relatively small coating thickness - allows to achieve the high strength. Although the deciding factor constitute, in this aspect, strength properties of a binder, its viscosity and ability to moisten the matrix surface, the essential meaning for the strength properties of the prepared moulding sand and the mould has the packing method of differing in sizes sand grains with the coating of the binding material deposited on their surfaces.

The knowledge of the influence of the compaction degree of grains forming the core on the total contact surface area can be the essential information concerning the core strength.

Forecasting the strength properties of core sands, at known properties of the applied chemically hardened binder and the quartz matrix, requires certain modifications of the existing theoretical models. They should be made more realistic with regard to assumptions concerning grain sizes composition of quartz sands and the packing structure deciding on the active surface area of the contacts between grains of various sizes and - in consequence - on the final strength of cores.
Methods of the Detection and Identification of Structural Defects in Saturated Metallic Composite Castings
Authors: Gawdzińska K.
Published: October 2017

Diagnostics of composite castings, due to their complex structure, requires that their characteristics are tested by an appropriate description method. Any deviation from the specific characteristic will be regarded as a material defect. The detection of defects in composite castings sometimes is not sufficient and the defects have to be identified. This study classifies defects found in the structures of saturated metallic composite castings and indicates those stages of the process where such defects are likely to be formed. Not only does the author determine the causes of structural defects, describe methods of their detection and identification, but also proposes a schematic procedure to be followed during detection and identification of structural defects of castings made from saturated reinforcement metallic composites. Alloys examination was conducted after technological process, while using destructive (macroscopic tests, light and scanning electron microscopy) and non-destructive (ultrasonic and X-ray defectoscopy, tomography, gravimetric method) methods. Research presented in this article are part of author’s work on castings quality.
The Effect of Type of Welding Sequence During Hardfacing Chromium Cast Iron for Erosion Resistance
Authors: Gucwa M. , Bęczkowski R. , Winczek J. , Wyleciał T.
Published: October 2017

The paper presents the capabilities of welding techniques to creating properties of wear resistant high chromium cast iron alloy. The use of the right kind of welding sequence allows you to change the structure and properties of the obtained welds. Tests were conducted for one type of additive material in the form of self shielded core wire. In order to determine the effect of the type of welding sequence on the properties of welds performed welding using string bead and weave bead. The resulting weld was tested on hardness and research structure in an optical microscope. In the following studies have been made erosive tests wear of made hardfacing. String beads gave structure rich in carbides and harder about 270 HV of the weld with weave bead. Also, wear resistance was nearly twice as better for welds made with string beads. In the experiment a decisive role in the resistance to wear plays a high hardness of the deposit and the presence of carbides in its structure. Changes in the basic parameters of the deposition process allows for the formation of structure and properties of hardfacing welds in a wide range.
Influence of Heat Treatment on Content of the Carbide Phases in the Microstructure of High-Speed Steel
Authors: Jaworski J. , Kluz R. , Trzepieciński T.
Published: October 2017

This article presents the results of investigations of the effect of heat treatment temperature on the content of the carbide phase of HS3-1-2 and HS6-5-2 low-alloy high-speed steel. Analysis of the phase composition of carbides is carried out using the diffraction method. It is determined that with increasing austenitising temperature, the intensification of dissolution of M6C carbide increases. As a result, an increase in the grain size of the austenite and the amount of retained austenite causes a significant reduction in the hardness of hardened steel HS3-1-2 to be observed. The results of diffraction investigations showed that M7C3 carbides containing mainly Cr and Fe carbides and M6C carbides containing mainly Mo and W carbides are dissolved during austenitisation. During austenitisation of HS3-1-2 steel, the silicon is transferred from the matrix to carbides, thus replacing carbide-forming elements. An increase in a degree of tempering leads to intensification of carbide separation and this process reduce the grindability of tested steels.
Intergranular Corrosion of the as Cast Hypoeutectic Zinc-Aluminium Alloy
Authors: Lachowicz M.M. , Lachowicz M.B.
Published: October 2017

The paper presents the research results of the solenoid housing made of the Zn4Al1Cu alloy that was destroyed as a result of corrosion. Surface of the tested part showed macroscopically the features typical for white corrosion, and the resulting corrosion changes led to a disturbance of the alloy cohesion. The research performed have shown that the tested solenoid valve has intergranular corrosion as a reaction of the environment containing road salt. The corrosion was initiated in the areas of the alfa phase existence appearing in the eutectic areas which propagated over dendritic areas of the alloy. Initiation of the corrosion followed as a result of the galvanic effect of the alfa phase reach in aluminium showing higher electrochemical potential, in contact with the eta phase reach in zinc. The impact of the phase reach in lead present in the microstructure on the corrosion processes run was not found.
Comparative Studies of Microstructure and Fatigue Life of Selected Lead-free Alloys
Authors: Pietrzak K. , Klasik A. , Maj M. , Sobczak N. , Wojciechowski A.
Published: October 2017

Lead-free alloys containing various amounts of zinc (4.5%, 9%, 13%) and constant copper addition (1%) were discussed. The results of microstructure examinations carried out by light microscopy (qualitative and quantitative) and by SEM were presented. In the light microscopy, a combinatorial method was used for the quantitative evaluation of microstructure. In general, this method is based on the phase quanta theory according to which every microstructure can be treated as an arrangement of phases/structural components in the matrix material. Based on this method, selected geometrical parameters of the alloy microstructure were determined. SEM examinations were based on chemical analyses carried out in microregions by EDS technique. The aim of the analyses was to identify the intermetallic phases/compounds occurring in the examined alloys. In fatigue testing, a modified low cycle fatigue test method (MLCF) was used. Its undeniable advantage is the fact that each time, using one sample only, several mechanical parameters can be estimated. As a result of structure examinations, the effect of alloying elements on the formation of intermetallic phases and compounds identified in the examined lead-free alloys was determined. In turn, the results of mechanical tests showed the effect of intermetallic phases identified in the examined alloys on their fatigue life. Some concepts and advantages of the use of the combinatorial and MLCF methods in materials research were also presented.
Coordinated Production Planning and Scheduling Problem in a Foundry
Authors: Stawowy A. , Duda J.
Published: October 2017

In the paper, we present a coordinated production planning and scheduling problem for three major shops in a typical alloy casting foundry, i.e. a melting shop, molding shop with automatic line and a core shop. The castings, prepared from different metal, have different weight and different number of cores. Although core preparation does not required as strict coordination with molding plan as metal preparation in furnaces, some cores may have limited shelf life, depending on the material used, or at least it is usually not the best organizational practice to prepare them long in advance. Core shop have limited capacity, so the cores for castings that require multiple cores should be prepared earlier. We present a mixed integer programming model for the coordinated production planning and scheduling problem of the shops. Then we propose a simple Lagrangian relaxation heuristic and evolutionary based heuristic to solve the coordinated problem. The applicability of the proposed solution in industrial practice is verified on large instances of the problem with the data simulating actual production parameters in one of the medium size foundry.
Improvement of Artistic Cast Production System
Authors: Władysiak R. , Pacyniak T. , Trzoska J.
Published: October 2017

The paper presents the technology and organization of the artistic cast production. On the basis of the actual cast production system, the manufacturing process was shown, in particular sand–piece moulding, which is a very important process and a time-consuming part of the entire manufacture of the casts. The current state of the production process as well as the organization of the work and production technology were analysed with the use of methods and techniques of production improvement, the Lean Manufacturing concept and computer systems. The results of the analysis and studies were shown with use of schemes and graphs of the layout of the production resources, a flow chart of the production process, value stream mapping, and a costs table for the production and modernization of the moulding stage. The work has shown that there are possibilities to improve the artistic cast production system. This improvement leads to increased productivity, lower production costs of artistic casts and increased competitiveness of the foundry.
Strength of the Bond of Structural Steel S235JR to Bronze SAE660 Produced by Casting in Pre-Mold
Authors: Zaheri M. , Vahdat S.E.
Published: October 2017

Different methods are used for production of bronze bearings. In terms of technical specifications, the success of each of these methods depends on the bond’s strength and in terms of economic, the production method is important. In this study, the aim is to study the strength and microstructure of steel-bronze thrust bearing bond that has been produced through the casting using pre-mold. In this study, in order to bond, the raw metals are chemically washed with sulfuric acid solution for five minutes at first. Then, the molten bronze SAE660 is cast in a structural steel S235JR pre-mold. The bond’s strength has been measured using the shear test three times; the measurement of bond’s length has been done using field emission scanning electron microscope (FESEM). The results indicate that the strength of the bond is at least 94.8 MPa and bond’s length is 0.45 micrometers. Therefore, this method was successful for trust bearing application.
Phase Field Study of Microstructure Evolution in Eutectoid Phase Transformation – I Nucleation
Authors: Zhang Dongqiao , Yin Yajun , Zhou Jianxin , Tu Zhixin
Published: October 2017

Eutectoid growth, as the important reaction mechanism of the carbon steel heat treatment, is the basis to control the microstructure and performance. At present, most studies have focused on lamellar growth, and did not consider the nucleation process. Mainly due to the nucleation theory is inconclusive, a lot of research can support their own theory in a certain range. Based on the existing nucleation theory, this paper proposes a cooperative nucleation model to simulate the nucleation process of eutectoid growth. In order to ensure that the nucleation process is more suitable to the theoretical results, different correction methods were used to amend the model respectively. The results of numerical simulation show that when the model is unmodified, the lateral growth of single phase is faster than that of longitudinal growth, so the morphology is oval. Then, the effects of diffusion correction, mobility correction and ledges nucleation mechanism correction on the morphology of nucleation and the nucleation rate were studied respectively. It was found that the introduction of boundary diffusion and the nucleation mechanism of the ledges could lead to a more realistic pearlite.
Friction and Wear Properties of Plasma Sprayed YSZ/Ni-Cr-Al Coated 6063-T6 Aluminum Alloy
Authors: Erzi E. , Dispinar D. , Yilmaz S.
Published: October 2017

In this study T6 heat treated 6063 aluminum alloys were used as substrate material. In order to form a bond between the substrate and the main coating, all samples were coated with Ni-Cr-Al powders. 8 wt% Yttria Stabilized Zirconia powders (YSZ) were coated with plasma spray technique. Thickness of YSZ was 150 μm and bond coating was 36 m. XRD and SEM-EDS analyses were performed to characterize the coating layers. These YSZ coated and uncoated samples were subjected to wear testing under different spindle speed, loading and working distance. Wear test results were compared with the kinetic friction coefficients and weight loss values. Wear marks on YSZ coated and uncoated samples were investigated by SEM analysis. By coating with plasma spray technique, the wear resistance of Al alloys was increased without changing the friction coefficient. It was found that spindle speed had significant effect over the wear properties than the load applied. By YSZ coating, wear properties were increased 10 times.
Assessment of the Harmfulness of the Slags from Copper Smelting Processes, in an Aspect of their Management
Authors: Holtzer M. , Bydałek A. , Wołczyński W. , Kmita A.
Published: October 2017

There are two methods to produce primary copper: hydrometallurgical and pyrometallurgical. Copper concentrates, from which copper matte is melted, constitute the charge at melting primary copper in the pyrometallurgical process. This process consists of a few stages, of which the basic ones are roasting and smelting. Smelting process may be bath and flash. Slag from copper production, on the end of process contain less 0,8%. It is treat as a waste or used other field, but only in a few friction. The slag amount for waste management or storage equaled 11 741 – 16 011 million tons in 2011. This is a serious ecological problem. The following slags were investigated: slag originated from the primary copper production process in the flash furnace of the Outtokumpuja Company in HM Głogów 2 (Sample S2): the same slag after the copper removal performed according the up to now technology (Sample S1): slag originated from the primary copper production process in the flash furnace of the Outtokumpuja Company in HM Głogów 2, after the copper removal performed according the new technology (Sample S3). In practice, all tested slags satisfy the allowance criteria of storing on the dumping grounds of wastes other than hazardous and neutral.
Tribological Response of Heat Treated AISI 52100 Steels Against Steel and Ceramic Counterparts
Authors: Türedi E. , Yilmaz M. , Senol V.
Published: October 2017

AISI 52100 bearing steels are commonly used in applications requiring high hardness and abrasion resistance. The bearing steels are working under dynamic loads in service conditions and their toughness properties become important. In order to provide the desired mechanical properties, various heat treatments (austenizing, quenching and tempering) are usually applied. In this study, AISI 52100 bearing steel samples were austenized at 900°C for ½ h and water quenched to room temperature. Then tempering was carried out at 795°C, 400°C and 200°C for ½ h. In order to investigate the effect of heat treatment conditions on wear behavior, dry friction tests were performed according to ASTM G99-05 Standard with a ‘ball-on-disk’ type tribometer. The samples were tested against steel and ceramic counterparts using the parameters of 100 m distance and 30 N load and 0.063 m/s rotational speed. After wear test, the surface characterization was carried out using microscopy. Wear loss values were calculated using a novel optical method on both flat and counterpart specimens.
The Analysis of AISI A3 Type Ferritic-Austenitic Cast Steel Crystallization Mechanism
Authors: Stradomski G.
Published: October 2017

High-alloy corrosion-resistant ferritic-austenitic steels and cast steels are a group of high potential construction materials. This is evidenced by the development of new alloys both low alloys grades such as the ASTM 2101 series or high alloy like super or hyper duplex series 2507 or 2707 [1-5]. The potential of these materials is also presented by the increasing frequency of sintered components made both from duplex steel powders as well as mixtures of austenitic and ferritic steels [6, 7]. This article is a continuation of the problems presented in earlier works [5, 8, 9] and its inspiration were technological observed problems related to the production of duplex cast steel.

The analyzed AISI A3 type cast steel is widely used in both wet exhaust gas desulphurisation systems in coal fired power plants as well as in aggressive working environments. Technological problems such as hot cracking presented in works [5, 8], with are effects of the rich chemical composition and phenomena occurring during crystallization, must be known to the technologists.

The presented in this work phenomena which occur during the crystallization and cooling of ferritic-austenitic cast steel were investigated using numerical methods with use of the ThermoCalc and FactSage® software, as well with use of experimental thermal-derivative analysis.
Assessment of Changes in Sod Under Intensive Use
Authors: Czarnecki Jarosław , Cudzik Anna , Brennensthul Marek , Białczyk Włodzimierz , Wolski Karol , Świerszcz Sebastian
Published: October 2017

The paper presents research results which aimed at evaluation of the change in the sodding degree and selected strength parameters of sod used with varied intensity; additionally sod was modified through administration of biopreparation. Measurements were taken on two types of sod. The first one was formed from perennial rye grass, the second one from orchard grass. It was proved that the use of the investigated facilities resulted in reduction of sodding, which was related to the sod forming species. No impact of biopreparation use on the sodding degree was proved. Intensive use affected the increase of the value of the analysed strength parameters; at low soil moisture (5.0-5.5%) considerable compaction in the surface layer of soil was reported.
Impact of Feed Mixture on Kinetic Strength of Pellets for Poultry
Authors: Sobol Zygmunt , Baran Dariusz , Major Marcin
Published: October 2017

The paper presents the impact of feed mixtures for poultry on their kinetic strength determined with Holmen's method. Research material came from a production line and 9 pelleted feed mixtures for poultry with diameter of 3.2 mm were accepted for the research. Feed was prepared, pelleted and cooled with the use of the same devices and their exploitation settings were comparable with regard to the investigated feed pellet. The obtained research results proved that kinetic strength of the investigated feed pellets was statistically significant in relation to the composition of the feed mixture. Relations of kinetic strength of pellets to the composition of the feed mixtures were determined with the multiple regression method. From the determined models the highest utilitarian value may occur in case of a model with four explanatory variables: corn (x1), wheat (x2), soya meal (x4) and fat (x5).
Modelling of Beetroot Seedlings with Modified Generalized Logistic Functions
Authors: Szparaga Agnieszka , Czerwińska Ewa
Published: October 2017

Modified generalized logistic functions (also known as Koya-Goshu functions) were used for mathematical description of germination. These functions constitute natural modification of traditionally used Richards' function for description of plants germination that introduces a non-linear time increase in exponent and an element related to time shift. Curves were adjusted to experimental data based on minimization of the square sum of difference between experimental data and a mathematical model (the smallest squares method). Results of simulation research show that the determined parameters of curves (e.g., values of the growth parameter, time shift or upper limit of population) describing the number of seedlings as a time function stay compliant to interpretation with regard to biology of the investigated processes. Based on the research, it was stated that for control and application of plant extracts to soil, Koyu-Gosha model has better adjustment to experimental data in comparison to the generalized logistic model.
Secret Image Enhanced Sharing Using Visual Cryptography
Authors: Brindha K. , Jeyanthi N.
Published: October 2017

In the conventional visual cryptographic scheme, an image is divided into several image shares, which are distributed among the members of a group, and the original image is retrieved by combining the shares of all the members. This secret image becomes accessible to every individual member and there is an inherent risk of any one of the members in the group using the valuable information for illegal purposes as an intruder. To overcome this problem, the proposed algorithm Secret Image Enhanced Sharing using Visual Cryptography (SIESVC) diligently facilitates any member in the group to retrieve either only a part or the complete secret image based purely on his access privilege rights only.
Approach for Analysis and Improved Usage of Digital Cultural Assets for Learning Purposes
Authors: Paneva-Marinova D. , Pavlov R. , Kotuzov N.
Published: October 2017

This paper presents an approach for analysis and improved usage of digital cultural assets for non-formal learning purposes in digital culture ecosystems. The digital culture ecosystems, their features, and an exemplar are discussed.
Stress corrosion characteristics of AL-Li-X alloys: role of GB precipitate size and spacing
Authors: Vasudevan A.K. , Sadananda K. , Ramgopal Thodla
Published: October 2017

Stress corrosion characteristics of three alloys, AL-3Li, AL-2Li-3Cu, and 5083, were analyzed. All three alloys have anodic grain boundary (GB) precipitates (ppts) (δ, T1, and β, respectively) that show different corrosion rates with respect to the lattice H diffusion. These GB phases grow with heat treatment time. These phases affect room-temperature fracture toughness in AL-3Li and AL-2Li-3Cu alloys but not in 5083 alloy. When exposed to NaCl solution, all three GB phases dissolve. Under an applied stress, the resulting stress corrosion threshold stress intensity K1sccvaries inversely with size and spacing, when the local crack tip environmental condition is established. The mechanism involved is mostly anodic dissolution with a secondary effect from hydrogen.
Pre-exposure embrittlement of a commercial Al-Mg-Mn alloy, AA5083-H131
Authors: Holroyd N. J. Henry , Burnett Timothy L. , Seifi Mohsen , Lewandowski John J.
Published: October 2017

Two distinct modes of environment-induce cracking (EIC) can initiate in AA5083-H131 during slow strain rate testing (SSRT) in laboratory air (50% RH) at nominal strain rates around 10−6/s, for material either sensitized in distilled water (DW) at 80°C or when material sensitized in dry air is subsequently pre-exposed to DW at room temperature. Type-1 EIC is the “classic” form of intergranular stress corrosion cracking (IGSCC), which during SSRT in laboratory air, initiates at intergranular corrosion (IGC) sites promoted during exposure to DW and provides the prerequisite local stress intensity factor of around 5 MNm−3/2required for crack initiation. When Type-1 EIC cracks become sufficiently deep for local plane-strain stress intensity factors to exceed 12–15 MNm−3/2, Type-2 EIC initiation triggers a series of sudden large load-drops and SSRT failures with extremely low fracture stresses (30–65 MPa). Pre-exposure to DW at room temperature can enhance propensity to both Type-1 and Type-2 EIC. SSRT in dry air, as opposed to humid laboratory air, exhibits failure consistently as a 45° slant failure via a predominantly ductile microvoid coalescence fracture mode, with Type-1 EIC very rarely initiating and any Type-2 EIC restricted to isolated internal patches that only form when relative elongations exceed ~9%.
Spectral properties of weathered and fresh rock surfaces in the Xiemisitai metallogenic belt, NW Xinjiang, China
Authors: Zhou Ke-Fa , Wang Shan-Shan
Published: October 2017

Surfaces weathering of rocks in which mineral materials may be similar to or quite different from the minerals in the underlying parent rock completely control the reflectance spectra of the terrain. Our study of typical weathered and fresh rock samples from the Xiemisitai metallogenic belt, Western Junggar region, Xinjiang, found that weathering results in the formation of new materials that cause differences in the spectral features of fresh and weathered rock surfaces. Alterations induce variations in spectrum brightness, presence and intensity of characteristic absorption features, and spectral slope. Spectral differences between weathered and fresh rock surfaces are small for rhyolite, granite, and tuffaceous sandstone, but large for andesite, basalt, and diorite. Spectral changes in the 350–1000 nm wavelength region are attributed to alteration of iron oxides by atmospheric processes or secondary alteration of iron-rich minerals. Spectral features between 1000–2500 nm are caused by O–H vibrations, with features at 2200–2500 nm solely attributed to hydroxyl groups. The strongest Al–OH bands appear near 2200 nm, while Mg–OH bands are found near 2300 nm and 2350 nm. Results from this study can be used to better characterize and discriminate lithological units and potential mineral zones using hyperspectral and multispectral remote sensing techniques.
Rhetoric, logic, and experiment in the quantum nonlocality debate
Authors: Graft Donald A.
Published: October 2017

This paper argues that quantum nonlocality (QNL) has not been rigorously proven, despite the existence of recent Einstein-Podolsky-Rosen-Bohm (EPRB) experiments that are claimed to be ‘loophole-free’. First, readers are alerted to rhetorical arguments, which are unfortunately often appealed to in the QNL debate, to empower readers to identify and reject such arguments. Second, logical problems in QNL proofs are described and exemplified by a discussion of the projection postulate problem. Third, experimental issues are described and exemplified by a discussion of the postselection problem. The paper concludes that QNL has not been proven and that locality cannot be excluded.
Ecology
Authors: Ternjej Ivancica , Mihaljevic Zlatko
Published: October 2017

Ecology is a science that studies the mutual interactions between organisms and their environment. The fundamental subject of interest in ecology is the individual. Topics of interest to ecologists include the diversity, distribution and number of particular organisms, as well as cooperation and competition between organisms, both within and among ecosystems. Today, ecology is a multidisciplinary science. This is particularly true when the subject of interest is the ecosystem or biosphere, which requires the knowledge and input of biologists, chemists, physicists, geologists, geographists, climatologists, hydrologists and many other experts. Ecology is applied in a science of restoration, repairing disturbed sites through human intervention, in natural resource management, and in environmental impact assessments.
A Comparative Assessment of Serum Vitamin C and Serum Lead Among Periodontitis and Diabetic Patient
Authors: Shetty Akshatha , Bhandary Rahul , Thomas Biju , Kumari Suchetha , Ramesh Amitha
Published: October 2017

Background and Aims: Pre and post-operative nutritional status are not often tested on a consistent basis when patients are analyzed and diagnosed with Type 2 Diabetes Mellitus (T2DM) or have chronic periodontitis. Thus, this study pursues to evaluate the predictive value of serum vitamin C and lead levels in this population at baseline and after periodontal treatment.

Materials and Methods: In an interventional study setting we enrolled 120 subjects which were later categorized into four sub-groups: set 1 – individuals with chronic periodontitis, set 2 – individuals with T2DM, set 3 – individuals with T2DM and chronic periodontitis respectively set 4 - healthy individuals as control group. Scaling and root planing was performed only to individuals with periodontitis and T2DM. At baseline and 21 days after periodontitis treatment blood was obtained from the subjects and analysis of serum vitamin C and serum lead was done and data obtained was statisticaly analysed.

Results: ANOVA test showed baseline values of both the parameters to be statistically significant different between groups and within groups (p<0.001). Alteration was seen in the parameters postoperatively regarding serum vitamin C was increased and lead level decreased; paired t-test showed statistically significant difference (p<0.001).

Conclusion: Serum Vitamin C can be considered a key biomarker. Increased lead level can be a risk factor for commencement and progression of T2DM and chronic periodontitis.
Risk Assessment of Diabetes Mellitus by Chaotic Globals to Heart Rate Variability via Six Power Spectra
Authors: Garner David M. , de Souza Naiara Maria , Vanderlei Luiz Carlos M.
Published: October 2017

Background: The priniciple objective here is to analyze cardiovascular dynamics in diabetic subjects by actions related to heart rate variability (HRV). The correlation of chaotic globals is vital to evaluate the probability of dynamical diseases.

Methods: Forty-six adults were split equally. The autonomic evaluation consisted of recording HRV for 30 minutes in supine position without any additional stimuli. “Chaotic globals” are then able to statistically determine which series of interbeat intervals are diabetic and which are not. Two of these chaotic globals, spectral Entropy and spectral Detrended fluctuation analysis were derived from six alternative power spectra: Welch, Multi-Taper Method, Covariance, Burg, Yule-Walker and the Periodogram. We then compared results to observe which power spectra provided the greatest significance by three statistical tests: One-way analysis of variance (ANOVA1); Kruskal-Wallis technique and the multivariate technique, principal component analysis (PCA).

Results: The Chaotic Forward Parameter One (CFP1) applying all three parameters is proven the most robust algorithm with Welch and MTM spectra enforced. This was proven following two tests for normality where ANOVA1 (p=0.09) and Kruskal-Wallis (p=0.03). Multivariate analysis revealed that two principal components represented 99.8% of total variance, a steep scree plot, with CFP1 the most influential parameter.

Conclusion: Diabetes reduced the chaotic response.
Antioxidant Effect of Purple Eggplant Flour (Solanum melongena L.) Against Oxidative Stress in Hyperglycaemic Rats
Authors: Fajriana Hasmar , Farmawati Arta , Lestari Lily Arsanti
Published: October 2017

Background and Aims: Oxidative stress in diabetes mellitus (DM) occurs due to an increase in free radicals and decreased antioxidant defenses including superoxide dismutase (SOD). It causes the occurrence of lipid peroxidation as indicated by the levels of malondialdehyde (MDA). Healthy foods that are rich in antioxidants are needed to reduce oxidative stress, such as eggplant (Solanum melongena L.). Until now there is no scientific evidence about the effects of purple eggplant against oxidative stress in hyperglycemia. The aim of this study is to determine the antioxidant effect of eggplant flour (TTU) against oxidative stress in hyperglycemic rats by induced Nicotinamide-Streptozotocin (NA-STZ).

Materials and Method: This experimental study was designed using posttest only. Thirty-six male Sprague Dawley rats, aged 10-12 weeks, body weight (bw) 207.25±26.76 grams were divided randomly into 5 groups, namely 2 control groups (normal and hyperglycemic) and 3 groups of treatment. Hyperglycemic rats were induced by NA-STZ (230-65 mg/kg bw). Administration of TTU through feed for 28 days varied with dose of 2.36 grams, 4.71 grams, and 7.07 grams in groups P1, 2, and 3, respectively. Examinations of blood glucose levels were conducted before intervention, whereas the antioxidant activity of SOD and MDA plasma levels were examined after intervention.

Results: The antioxidant activity of SOD in groups which were given TTU was higher than the hyperglycemic rats (31.19±1.98%), but lower than the normal group (220.83±23.68%) Levels of plasma MDA in groups which were given TTU were lower than the hyperglycemic rats (220.47±5.24 nmol/L), but higher than the normal group (1.55±0.20 nmol/L). The antioxidant activity of SOD in the P3 group (69.29±3.82%) was higher than the P1 group (41.84±3.82%) and the P2 group (55.10±3.23%), while the levels of plasma MDA in the P3 group (1.89±0.17 nmol/L) was lower than the P1 group (3.79±0.24 nmol/L) and the P2 group (3.17±0.53 nmol/L).

Conclusion: The results of this study demonstrate that administration of TTU significantly prevents oxidative stress in hyperglycemic rats.
Susceptibility of Postharvest Pathogens to Esential Oils
Authors: Božik M. , Nový P. , Klouček P.
Published: October 2017

Antimicrobial volatile substances from plants represent alternatives to synthetic pesticides and food preservatives. In this study, the compositions of some essential oils were determined by gas chromatography with mass spectrometry, and the inhibitory properties of the essential oils and their components against the bacterial postharvest pathogens Pectobacterium carotovorum subsp. carotovorum (CCM 1008), Pseudomonas syringae (CCM 7018), Xanthomonas campestris (CCM 22) were determined by the microdilution method. Essential oils from oregano, cinnamon, lemongrass, lavender, clove, rosemary, tea tree, eucalyptus, garlic, and ginger and their components cinnamaldehyde, eugenol, thymol, and carvacrol were used in the tests. The essential oil components exhibited strong antibacterial activity against all tested bacteria. The oregano and cinnamon essential oils were most effective. The rosemary, lavender, tea tree, eucalyptus, garlic, and ginger oils were not effective at the tested concentrations. In conclusion, certain essential oils, particularly their components, are highly effective and could be used for the control of postharvest bacterial pathogens.
On Vascular Bundle Modifications in Nodes and Internodes of Selected Grass Species
Authors: Kraehmer H.
Published: October 2017

Grass nodes play an essential role as interfaces between leaf and stem. The description of the bundle course in nodes considerably contributes to understanding of the transport of assimilates, minerals, and xenobiotics in grasses. Nodes and internodes of 38 species of the subfamilies Arundinoideae, Bambusoideae, Panicoideae, and Pooideae were analyzed histologically. Free-hand sections, various staining techniques, macro- and microphotography were used to reveal a few principles underlying their anatomy. In all grass species, specific nodal zones were found in which many vascular bundles undergo characteristic transformations. This transformation starts with the augmentation of xylem in lower nodal areas and continues with the formation of specific amphivasal structures providing connections with the leaf attached to the node. The anatomy of these strands, herein called vasotubuli, has not much in common with vascular bundles in internodes any more. Transverse nodal plexus strands provide many connections between bundles and vasotubuli. The nodal plexus is also an interface of sclerenchyma bundles. The nodes of most grass species are constructed very similarly with a few exceptions: the nodes ofPhragmites australis(Cav.) Steud. for example have something in common with bamboo: they develop spindle-like glomeruli.
Gastrointestinal Parasites in Giraffes Kept in Zoological Gardens of the Czech Republic
Authors: Kyriánová I.A. , Drnek J. , Langrová I. , Peřinková P. , Nechybová S.
Published: October 2017

Parasite prevalence was investigated in giraffes (Giraffa camelopardalis) housed in six major Czech zoological gardens: Zoo Ostrava, Zoo Dvůr Králové nad Labem, Zoo Liberec, Zoo Olomouc, Zoo Praha, and Zoo Plzeň. In autumn 2012 and in spring 2013, 120 faecal samples from 21 animals were examined using the McMaster egg counting technique. Propagative stages of three parasite groups were discovered, namely eggs of the nematodes of the order Strongylida (prevalence 25.8%), whipworms Trichuris spp. (prevalence 25%), and oocysts of the unicellular coccidia of the genus Eimeria (prevalence 1.7%). The results indicate that captive giraffes in the Czech zoos are not substantially affected by parasitic infection.
Methods of Studying Diversity of Bacterial Comunities: A Review
Authors: Salmonová H. , Bunešová V.
Published: October 2017

Bacterial life is a predominant component of all environments, occurring in communities usually of complex diversity. Bacteria are engines of globally important processes which makes them subject of interest to many scientific studies. Although many kinds of methods have been developed and microbial ecology has undergone a profound change in the last two decades with regard to methods employed, the analysis of community composition and function still remains a great challenge. In this article we present an overview of methods commonly used for the study of bacterial diversity. Emphasis was placed on cultivation, biochemical and chemotaxonomic, and molecular-genetic based methods.
Research for Coupled van der Pol Systems with Parametric Excitation and Its Application
Authors: Qian Y. H. , Fu H. X.
Published: October 2017

In this article, we study the primary resonances of van der Pol systems with parametric excitation using the multiple scales method (MSM) and the homotopy analysis method (HAM). First, we study the nonlinear dynamic response of a coupled system with parametric excitation when the ratio of internal resonances are different, and obtain the four-dimensional average equation of the rectangular coordinate form using the MSM, thereby periodic motions are found in the system. Second, using the HAM, we obtain the four periodic solutions, in which there are two sets of in-phase periodic solutions and two sets of out-of-phase periodic solutions. Finally, we obtain the frequency response curves using the MSM and the HAM, in which it is found that the differences could be ignored.
Localised Nonlinear Waves in the Three-Component Coupled Hirota Equations
Authors: Xu Tao , Chen Yong
Published: October 2017

We construct the Lax pair and Darboux transformation for the three-component coupled Hirota equations including higher-order effects such as third-order dispersion, self-steepening, and stimulated Raman scattering. A special vector solution of the Lax pair with 4×4 matrices for the three-component Hirota system is elaborately generated, based on this vector solution, various types of mixed higher-order localised waves are derived through the generalised Darboux transformation. Instead of considering various arrangements of the three potential functions q
1, q
2, and q
3, here, the same combination is considered as the same type solution. The first- and second-order localised waves are mainly discussed in six mixed types: (1) the hybrid solutions degenerate to the rational ones and three components are all rogue waves; (2) two components are hybrid solutions between rogue wave (RW) and breather (RW+breather), and one component is interactional solution between RW and dark soliton (RW+dark soliton); (3) two components are RW+dark soliton, and one component is RW+bright soliton; (4) two components are RW+breather, and one component is RW+bright soliton; (5) two components are RW+dark soliton, and one component is RW+bright soliton; (6) three components are all RW+breather. Moreover, these nonlinear localised waves merge with each other by increasing the absolute values of two free parameters α, β. These results further uncover some striking dynamic structures in the multicomponent coupled system.
Development of Strength Models for Prediction of Unconfined Compressive Strength of Cement/Byproduct Material Improved Soils
Authors: Abbey S. J. , Ngambi S. , Ganjian E.
Published: October 2017

This paper presents the possible inclusion of pulverized fuel ash (PFA) and ground granulated blast slag (GGBS) in cement deep soil mixing for enhancement of unconfined compressive strength (UCS) of weak soil materials for construction purposes. The main focus of this paper was to investigate the UCS of cement-, cement/PFA- and cement/PFA/GGBS-improved soils, and development of mathematical and graphical models for prediction of UCS for use in design and construction. Samples of cement, blends of cement and PFA, and cement/PFA/GGBS were prepared using 5 %, 10 %, 15 %, and 20 % by weight of dry soil and tested for UCS after 7, 14, 28, and 56 days. A multiple regression analysis was conducted using the SPSS computer program. The results showed that soil materials with lower plasticity show higher strength development compared to those of higher plasticity for cement improvement. The study has also revealed that the inclusion of PFA and GGBS can cause a reduction in the amount of cement in deep soil mixing, which can result to reduced cost and emission of carbon dioxide (CO2) during construction. The developed mathematical and graphical models could give reliable predictions of UCS for weak soil materials with initial UCS less than or equal to 25 kPa and for water to binder ratio of unity based on the observed agreement between experimental and predicted data. The developed multiple regression models have also been validated using different mixtures of 6 %, 8 %, 12 %, and 16 % of binders.
Transiently Loaded Bucket Foundations in Saturated Dense Sand - Demonstration of the Boot Effect
Authors: Nielsen Søren Dam , Ibsen Lars Bo , Nielsen Benjaminn Nordahl
Published: October 2017

The mono bucket foundation is a cost-effective foundation for offshore wind turbines. During a storm, these foundations are exposed to large wave loads of short duration. This paper investigates the effect of increased loading rate on the bearing capacity of two mono bucket foundations installed in dense sand inside a pressure tank. The foundations had aspect ratios (skirt lengths [L] relative to the diameters [D]), L/D, of 0.5 and 1.0, respectively. Foundations were brought to failure with varying loading rates, resulting in drained, partly drained, or undrained behavior. Increases in bearing capacity were observed as the loading rate increased. This behavior was caused by a combination of dilative soil behavior and suction created by upward movement, known as the boot effect. For mono bucket foundations, the boot effect resulted in an increased bearing capacity that was 18 to 25 times higher than the drained capacity. Furthermore, the boot effect also led to an increase in stiffness. The stiffness of the partly drained response is measured up to four times higher compared with drained behavior.
Failure Analysis of an Arresting Hook Point Shank
Authors: MacKenzie D. Scott
Published: October 2017

During full-scale fatigue testing, an F/A-18 E/F arresting hook point shank failed after 1,361 simulated arrestments. This part is designed to last 4,500 arrestments without cracking. Therefore, an investigation was undertaken to determine the cause of premature catastrophic failure.
Lernen und die gesellschaftliche Reproduktion: Vier Thesen über die Wirksamkeit von Ideologie in der Schule
Authors: Brandmayr Michael
Published: October 2017

Der Beitrag beschreibt einige zentrale Überlegungen, unter welchen Voraussetzungen schulische Praktiken als Ideologien beschrieben werden können und in welchem Maße die Schule an der ideologischen Reproduktion der Gesellschaft beteiligt ist. Der Beitrag entwirft vier Thesen über die Wirkungsweise von Ideologie in der Schule, die sich der Frage einer ökonomischen Funktionalisierung von Lernen, des Sozialen bzw. der Sozialität in Formen der Subjektivierung sowie der Dialektik des Prozesses der ideologischen Vermittlung widmen. Diese Thesen werden auf Basis einer diskursanalytischen Untersuchung eines schulpädagogischen Leitbildes von idealem Lernen im österreichischen Schulsystem (Brandmayr 2017) entwickelt, deren Ergebnisse nach einer Diskussion des Ideologiebegriffs dargestellt werden. Ideologie wird in diesem Beitrag als wesentlich durch Praktiken vermittelt begriffen, in der Schule besonders durch die Praktik des Lernens. Diese Praktiken strukturieren Wahrnehmungs- und Interpretationsweisen und leiten Subjektivierungsvorgänge an. Über die Analyse des Lernens kann also gefragt werden, wie die Schule zur Vermittlung von Ideologien und damit zur Reproduktion der Gesellschaft beiträgt.
Genetic Screening for EMS-Induced Maize Embryo-Specific Mutants Altered in Embryo Morphogenesis
Authors: Brunelle Dale C , Clark Janice K , Sheridan William F
Published: October 2017

We have previously identified embryo-specific (emb) mutations that resulted in maize kernels containing abnormal embryos with normal-appearing endosperm among the progeny of active Robertson’s Mutator stocks. Our rationale for the mutant screen described here is that it should be possible to produce ethyl methane sulfonate (EMS)-induced emb mutations at a frequency higher than that obtained by transposon mutagenesis and with greater ease. This proved to be the case when we screened for mutations that are embryo-specific among progeny of materials generated with EMS-treated pollen. The EMS-induced emb mutation frequency reported here is nearly three times the 4.5% we obtained with the transposable element stocks. The 45 mutants reported here were all tested for germination capacity and nearly all were lethal. The embryo phenotypes of 34 mutations were examined by dissection of the mature embryos. All were found to be retarded in development and morphologically abnormal. Half of the mutants in this group were blocked in the proembryo and transition stages. They likely include mutations in nuclear genes coding for plastid proteins. The other 17 are mainly blocked in the coleoptilar stage, or in later stages with a low frequency. This group likely includes mutations in genes regulating the completion of shoot apical meristem (SAM) development and accompanying morphogenetic events. Most of the complementation tests using 19 of the mutations in 35 unique combinations complimented each other, except for two pairs of mutations with similar phenotypes. Our results provide additional evidence for the presence of many emb loci in the maize genome.
Elementos epistemológicos para una interpretación social de la ciudad
Authors: Otárola Guevara Marcela
Published: October 2017

El crecimiento urbano en la Gran Área Metropolitana (GAM) de Costa Rica se incrementó, sustancialmente, en las últimas tres décadas, manifestándose claramente en su forma espacial. Sin embargo, esta permuta es la expresión de otra más profunda: una procedente del cambio en su forma social; por eso, para comprender e interpretar la transformación en este ámbito, es preponderante establecer una posición epistemológica. Así, partiendo del supuesto de la ciudad como una construcción social, en este escrito se exponen los criterios teóricos de algunos científicos cuyos aportes, desde una perspectiva crítica, permiten el análisis de la urbe como una red y una representación. El objetivo del acopio y la concatenación de tales abonos es formular un itinerario teórico con el cual elucidar en los poblados urbanos, los procesos velados que los transfiguran y que presentan una dualidad: son causados por la acción humana y su efecto recae en ella; dialéctica constante que amerita un abordaje cognitivo que considere la ciudad como un ente vivo, en tensión e inacabado